Treatment of Acromegaly,Cushing Disease and Nelson Syndrome

Since 1957 we have treated more than 429 patients who had pituitary neoplasms, most of which were hormone-secreting tumors. Long-term follow-up in the large group of patients treated for acromegaly shows a median survival of better than 16 years, with improvement over time. The short-term follow-up results in patients with Cushing^* disease, Nelson syndrome and chromophobe adenoma are very encouraging. To compare these excellent results with those following surgical procedures, a large study of patients followed for a long period after the operations is needed.     

Diagnosis by Serendipity: Cushing Syndrome Attributable to Cortisol-Producing Adrenal Adenoma as the Initial Manifestation of Multiple Endocrine Neoplasia Type 1 Due to a Rare Splicing Site Men1 Gene Mutation

ObjectiveTo report a case that highlights the potential for Cushing syndrome to be the first manifestation of multiple endocrine neoplasia type 1 (MEN 1) syndrome and to describe the rare underlying genetic mutation and the heterogeneous manifestations of the syndrome within the same family.MethodsWe present a case report including biochemical and radiologic findings, review family data, and discuss the results of genetic analyses.ResultsA 16-year-old girl who was not known to have any medical illness and had no known family history of MEN 1 syndrome presented with Cushing syndrome attributable to a cortisol-producing adrenal adenoma. During her evaluation, she was found to have primary hyperparathyroidism and a pituitary microprolactinoma. These findings raised the possibility of MEN 1 syndrome. She did not have clinical, biochemical, or radiologic evidence of islet cell pancreatic tumors. Family screening showed that her father had evidence of primary hyperparathyroidism, mild hyperprolactinemia, normal findings on magnetic resonance imaging of the pituitary, and a 1.2- cm nodule in the tail of the pancreas in conjunction with slight elevation of serum insulin and normal gastrin levels. The patient’s 5 siblings had evidence of primary hyperparathyroidism, and 2 of them also had mild hyperprolactinemia. Genetic screening confirmed the presence of a MEN1 gene missense G to A mutation in the patient, her father, and her siblings at the splicing site of intron 6 (IVS6 + 1G > A). This mutation leads to frameshift and truncation of the MEN1 gene.ConclusionIn MEN 1, Cushing syndrome is an extremely rare and usually late manifestation. Most cases are due to corticotropin-producing pituitary adenomas. Although Cushing syndrome generally develops years after the more typical manifestations of MEN 1 appear, it may be the primary manifestation of MEN 1 syndrome. There is considerable heterogeneity in the manifestations of MEN 1, even within a family having the same genetic mutation. (Endocr Pract. 2008;14:595-602)     

Protecting Reproductive Health and Choice

Women and men have special needs in rehabilitation. Women''s needs, however, have received far less attention in the scientific community and medical literature. This section, edited by Sandra Cole, PhD,^* highlights some of the unique concerns of women who live with physical disabilities.     

Type of Practice of Physicians in California,Report of the Bureau of Research and Planning

The total number of non-federal^* physicians in California rose from 23,065 in mid-1959 to 26,271 in January, 1962, an 11.3 per cent increase. The proportion of physicians in private active practice remained almost constant during this period.A significant rise, both in number and proportionally, took place in the full-time specialty category, offset by losses in the general practice-part-time specialty group. While specialists increased by over 30 per cent, general practitioners, who made up 31.7 per cent of all non-federal physicians in 1959, were only 24.7 per cent of the total in early 1962.     

On the innervation of mammalian endocrine glands (anterior pituitary and parathyroids)

Summary Electron microscopic studies have been carried out on the innervation of the mammalian anterior pituitary and parathyroids. The total area of grid squares (2.25·10^–2mm²) examined was 2000 per gland and species. In the pituitary pars distalis and in the parenchyma of the parathyroid gland we did not observe a single axon profile. According to the equation proposed by Hennig (1963) we have calculated that there might be—if any—0.133 mm of nerves per 1 mm³ tissue in those two endocrine glands (level of significance 0.95). Comparing these results to the degree of innervation in brown adipose tissue containing more than 160 mm nerve per 1 mm³ tissue we can not imagine that such a small degree of innervation is of any biological importance.In the pituitary pars tuberalis two types of axon terminals have been found both inside and outside the basement membrane surrounding the epithelial complexes. One type contains synaptic and two populations of smaller dense-cored vesicles, the other one contains a population of larger granules which have some properties of the classical elementary granules. Further investigations have to clarify the functional significance of those nerve endings.This investigation was supported by the Deutsche Forschungsgemeinschaft.     

Cushing Disease Revealed by Bilateral Atypical Central Serous Chorioretinopathy: Case Report

ObjectiveWe report the case of a patient with Cushing disease revealed by bilateral central serous chorioretinopathy (CSCR).MethodsWe present the clinical history, physical findings, laboratory results, and imaging studies of a 53-year- old Chinese woman with a Cushing disease revealed by bilateral CSCR. The association with CSCR and the pertinent literature are reviewed.MethodsWe present the clinical history, physical findings, laboratory results, and imaging studies of a 53-year- old Chinese woman with a Cushing disease revealed by bilateral CSCR. The association with CSCR and the pertinent literature are reviewed.ResultsA 53-year-old patient initially presented to the Department of Ophthalmology with a 4-week history of decreased vision in the left eye. Standard ophthalmologic examination and fluorescein angiography established the diagnosis of bilateral CSCR. Systemic clinical signs and biochemical analysis indicated hypercortisolism. Magnetic resonance imaging (MRI) of the pituitary gland showed a left-side lesion compatible with a microadenoma. The diagnosis of Adrenocorticotropic hormone (ACTH)-dependent Cushing syndrome secondary to a pituitary microadenoma was selected. Endoscopic endonasal transsphenoidal surgery was performed and the pituitary adenoma was successfully removed. The histology confirmed the presence of ACTH-immunopositive pituitary adenoma. Early postoperative morning cortisol levels indicated early remission. At 6 weeks postoperatively, the patient’s morning cortisol remains undetectable, and serous retinal detachments had regressed.ConclusionCSCR is an uncommon manifestation of endogenous Cushing syndrome. It can be the first presentation of hypercortisolism caused by Cushing disease. CSCR should be considered when assessing patients with Cushing syndrome complaining of visual disorders. On the other hand, it is useful in patients with an atypical form of CSCR to exclude Cushing’s syndrome. (Endoer. Praet. 2013;19:el29-el33)     

Human ACAP2 is a homolog of C. elegans CNT-1 that promotes apoptosis in cancer cells

Activation of caspases is an integral part of the apoptotic cell death program. Collectively, these proteases target hundreds of substrates, leading to the hypothesis that apoptosis is “death by a thousand cuts”. Recent work, however, has demonstrated that caspase cleavage of only a subset of these substrates directs apoptosis in the cell. One such example is C. elegans CNT-1, which is cleaved by CED-3 to generate a truncated form, tCNT-1, that acquires a potent phosphoinositide-binding activity and translocates to the plasma membrane where it inactivates AKT survival signaling. We report here that ACAP2, a homolog of C. elegans CNT-1, has a pro-apoptotic function and an identical phosphoinositide-binding pattern to that of tCNT-1, despite not being an apparent target of caspase cleavage. We show that knockdown of ACAP2 blocks apoptosis in cancer cells in response to the chemotherapeutic antimetabolite 5-fluorouracil and that ACAP2 expression is down-regulated in some esophageal cancers, leukemias and lymphomas. These results suggest that ACAP2 is a functional homolog of C. elegans CNT-1 and its inactivation or downregulation in human cells may contribute to cancer development.The caspases (cysteine aspartic acid proteases) are a class of proteases with diverse roles in cellular physiology including differentiation, inflammation and cell death.^1–3 Caspases play a critical role in apoptosis, where they collectively target hundreds of proteins. One prevailing view is that caspases drive apoptosis through a mass action effect due to hundreds of proteolytic cleavage events that lead to cellular disassembly and cell death.⁴ Recent studies, however, suggest that proteolysis of most substrates may simply be a bystander effect and that caspase cleavage of key proteins controlling a few specific cellular processes is what functionally drives apoptosis.⁵ Although much of the work to date has focused on factors acting upstream of caspase activation, it is becoming increasingly clear that events downstream of this commitment step are also tightly regulated and critically important for apoptosis. Presently, there is evidence of requirements for caspase-mediated control of the BCL2 family of anti-apoptotic proteins, mitochondrial elimination, chromosome fragmentation, phosphatidylserine externalization, and, as we have recently reported, inactivation of the AKT survival signaling pathway in programmed cell death (6-10 Therefore, a more thorough understanding of physiologically relevant caspase targets will increase our understanding of apoptosis in the context of animal development and disease.

Table 1

Human homologues of functional caspase targets in C. elegans. A summary of identified caspase substrates and caspase downstream events important for cell death execution in C. elegans and humans

Anatomic,Hematologic, and Biochemical Features of C57BL/6NCrl Mice Maintained on Chronic Oral Corticosterone

Metabolic syndrome is a condition that typically includes central obesity, insulin resistance, glucose intolerance, dyslipidemia, and hypertension. Disruption of the hypothalamic–pituitary–adrenal axis, a regulator of corticosterone secretion, occurs in some cases of metabolic syndrome and obesity, and Cushing hypercortisolemia is associated with obesity and metabolic disorders. We therefore assessed anatomic and clinical pathology in C57BL/6NCrl mice to evaluate the effects of chronic corticosterone in the drinking water at doses of 25, 50, and 100 μg/mL for 25 d. Treated mice developed obesity, glucose intolerance, electrolyte aberrations, and dyslipidemia that were dose-dependent and most severe in the 100-μg/mL treatment group. To evaluate return to normal function, additional C57BL/6NCrl mice received corticosterone-free water for 2 wk after the 25-d treatment period. According to results of gross examination, mice appeared to recover within days of exogenous corticosterone withdrawal; however, adrenal gland vacuolation and protein, lipid, and electrolyte abnormalities persisted. Together, these findings support chronic corticosterone exposure through the drinking water as a potentially useful, noninvasive method to induce some features of metabolic syndrome.Obesity and associated metabolic dysfunctions are an increasing public health concern in modern Western society. In humans, obesity and metabolic syndrome heighten the risk of developing debilitating and costly illness including diabetes, cardiovascular disease, stroke, and some forms of cancer.^2,20 Mounting evidence indicates that stress and associated hormones such as cortisol (corticosterone in rodents) contribute to the development of metabolic syndrome. Furthermore, regional glucocorticoid metabolism in adipocytes is proposed to be involved in the pathogenesis of metabolic syndrome.^{6,16,17,27,56} Cushing syndrome, iatrogenic hypercortisolemia, and metabolic syndrome share clinical and physiologic similarities, including central obesity, insulin resistance, glucose intolerance, dyslipidemia, and hypertension.^{1,2,31,35,41,46} How glucocorticoids contribute to the development of these problems remains unclear.Numerous clinical and experimental studies have linked stress, diet, and lifestyle choices to changes in risk factors associated with the development of metabolic disorders.^{1,3,7,10,21,33,36,42,55} How corticosterone influences this risk remains unclear. Although corticosterone has beneficial short-term effects, long-term corticosterone exposure can result in damage to the physiologic systems it protects acutely.²⁷ Disruption of this physiologic signal occurs in numerous disparate disorders, ranging from depression to Cushing syndrome.^16,22,36,54 Therefore, understanding the effects of chronic high corticosterone on metabolism and physiology is of key importance.To clarify how chronic treatment with corticosterone alters the physiology of an organism, we treated adrenally intact adult male mice with corticosterone in drinking water for 4 wk. Furthermore, we examined the return of physiology 2 wk after withdrawal of chronic corticosterone administration. We used this approach as a rapid (3- to 4-wk), noninvasive method of altering plasma corticosterone levels that enabled us to retain some integrity in the diurnal rhythm present in normal animals.We previously characterized the gross metabolic consequences of exogenous noninvasive corticosterone delivery in the drinking water.^20,28 In those studies, we found that high doses of corticosterone (100 μg/mL) resulted in rapid and dramatic hyperphagia; weight gain; increased adiposity; elevated plasma corticosterone, leptin, insulin, and triglyceride levels; and decreased homecage locomotion.²⁰ Moreover, several studies have shown that a lower dose of corticosterone (25 μg/mL) resulted in an intermediate phenotype in some of these measures but had no effect on others.^{12,14,20,23,28,38,42,47} As such, the high corticosterone dose results in a phenotype that satisfies most of the criteria for metabolic syndrome as defined by the National Heart, Lung, and Blood Institute and the American Heart Association.¹⁵ However, little information is available on the resulting histologic, hematologic, and serum chemical profiles associated with this treatment. We sought to more fully characterize this model to support selection of the model that most accurately reflects the human disease conditions under study. In-depth characterization of the model also provides more precise measurements of response to therapies intended to ameliorate the effects of the treatment.The current study provides a detailed examination of the physiologic effect of 3 dosages of corticosterone—low (25 μg/mL), intermediate (50 μg/mL), and high (100 μg/mL) doses—in drinking water. The goal was to extend the previous findings that established this regimen as a model of metabolic syndrome by exploring the detailed physiologic changes associated with this model and to assess whether and how treated mice recover after withdrawal of the corticosterone treatment. We propose that the physiologic changes observed in the mice treated with high-dose corticosterone approximate changes observed in human patients with metabolic syndrome and that these mice potentially serve as a model for hypercortisolemia and associated obesity. In addition, we hypothesized that 2 wk of recovery from corticosterone treatment would not completely resolve cellular and clinical pathologies characterized during treatment, given the numerous changes in physiology.     

Rehabilitation in the Philippines

The international community has perspective and experience that will freshen our approaches to rehabilitation. Martin Grabois, MD^*, editor of this special section, has gathered articles written by experts from other countries. The intention is to stimulate thought, discussion, and action—and to broaden horizons.     

IDEAL-Q, an Automated Tool for Label-free Quantitation Analysis Using an Efficient Peptide Alignment Approach and Spectral Data Validation

In this study, we present a fully automated tool, called IDEAL-Q, for label-free quantitation analysis. It accepts raw data in the standard mzXML format as well as search results from major search engines, including Mascot, SEQUEST, and X!Tandem, as input data. To quantify as many identified peptides as possible, IDEAL-Q uses an efficient algorithm to predict the elution time of a peptide unidentified in a specific LC-MS/MS run but identified in other runs. Then, the predicted elution time is used to detect peak clusters of the assigned peptide. Detected peptide peaks are processed by statistical and computational methods and further validated by signal-to-noise ratio, charge state, and isotopic distribution criteria (SCI validation) to filter out noisy data. The performance of IDEAL-Q has been evaluated by several experiments. First, a serially diluted protein mixed with Escherichia coli lysate showed a high correlation with expected ratios and demonstrated good linearity (R² = 0.996). Second, in a biological replicate experiment on the THP-1 cell lysate, IDEAL-Q quantified 87% (1,672 peptides) of all identified peptides, surpassing the 45.7% (909 peptides) achieved by the conventional identity-based approach, which only quantifies peptides identified in all LC-MS/MS runs. Manual validation on all 11,940 peptide ions in six replicate LC-MS/MS runs revealed that 97.8% of the peptide ions were correctly aligned, and 93.3% were correctly validated by SCI. Thus, the mean of the protein ratio, 1.00 ± 0.05, demonstrates the high accuracy of IDEAL-Q without human intervention. Finally, IDEAL-Q was applied again to the biological replicate experiment but with an additional SDS-PAGE step to show its compatibility for label-free experiments with fractionation. For flexible workflow design, IDEAL-Q supports different fractionation strategies and various normalization schemes, including multiple spiked internal standards. User-friendly interfaces are provided to facilitate convenient inspection, validation, and modification of quantitation results. In summary, IDEAL-Q is an efficient, user-friendly, and robust quantitation tool. It is available for download.Quantitative analysis of protein expression promises to provide fundamental understanding of the biological changes or biomarker discoveries in clinical applications. In recent years, various stable isotope labeling techniques, e.g. ICAT (1), enzymatic labeling using ¹⁸O/¹⁶O (2, 3), stable isotope labeling by amino acids in cell culture (4), and isobaric tagging for relative and absolute quantitation (2, 5), coupled with LC-MS/MS have been widely used for large scale quantitative proteomics. However, several factors, such as the limited number of samples, the complexity of procedures in isotopic labeling experiments, and the high cost of reagents, limit the applicability of isotopic labeling techniques to high throughput analysis. Unlike the labeling approaches, the label-free quantitation approach quantifies protein expression across multiple LC-MS/MS analyses directly without using any labeling technique (7–9). Thus, it is particularly useful for analyzing clinical specimens in highly multiplexed quantitation (10, 11); theoretically, it can be used to compare any number of samples. Despite these significant advantages, data analysis in label-free experiments is an intractable problem because of the experimental procedures. First, although high reproducibility in LC is considered a critical prerequisite, variations, including the aging of separation columns, changes in sample buffers, and fluctuations in temperature, will cause a chromatographic shift in retention time for analytes in different LC-MS/MS runs and thus complicate the analysis. In addition, under the label-free approach, many technical replicate analyses across a large number of samples are often acquired; however, comparing a large number of data files further complicates data analysis and renders lower quantitation accuracy than that derived by labeling methods. Hence, an accurate, automated computation tool is required to effectively solve the problem of chromatographic shift, analyze a large amount of experimental data, and provide convenient user interfaces for manual validation of quantitation results.The rapid emergence of new label-free techniques for biomarker discovery has inspired the development of a number of bioinformatics tools in recent years. For example, Scaffold (Proteome Software) and Census (12) process PepXML search results to quantify relative protein expression based on spectral counting (13–15), which uses the number of MS/MS spectra assigned to a protein to determine the relative protein amount. Spectral counting has demonstrated a high correlation with protein abundance; however, to achieve good quantitation accuracy with the technique, high speed MS/MS data acquisition is required. Moreover, manipulations of the exclusion/inclusion strategy also affect the accuracy of spectral counting significantly. Because peptide level quantitation is also important for post-translational modification studies, the accuracy of spectral counting on peptide level quantitation deserves further study.Another type of quantitation analysis determines peptide abundance by MS¹ peak signals. According to some studies, MS¹ peak signals across different LC-MS/MS runs can be highly reproducible and correlate well with protein abundance in complex biological samples (7–9). Quantitation analysis methods based on MS¹ peak signals can be classified into three categories: identity-based, pattern-based, and hybrid-based methods (16). Identity-based methods (7–9) depend on the results of MS/MS sequencing to identify and detect peptide signals in MS¹ data. However, because the data acquisition speed of MS scanning is insufficient, a considerable number of low abundance peptides may not be selected for limited MS/MS sequencing. Only a few peptides can be repetitively identified in all LC-MS/MS runs and subsequently quantified; thus, only a small fraction of identified peptides are quantified, resulting in a small number of quantifiable peptides/proteins.In contrast to identity-based methods, pattern-based methods (17–23), including the publicly available MSight (20), MZmine (21, 22), and msInspect (23), tend to quantify all peptide peaks in MS¹ data to increase the number of quantifiable peptides. These methods first detect all peaks in each MS¹ data and then align the detected peaks across different LC-MS/MS runs. However, in pattern-based methods, efficient detection and alignment of the peaks between each pair of LC-MS/MS runs are a major challenge. To align the peaks, several methods based on dynamic programming or image pattern recognition have been proposed (24–26). The algorithms applied in these methods require intensive computation, and their computation time increases dramatically as the number of compared samples increases because all the LC-MS/MS runs must be processed. Therefore, pattern-based approaches are infeasible for processing a large number of samples. Furthermore, pattern recognition algorithms may fail on data containing noise or overlapping peptide signal (i.e. co-eluting peptides). The hybrid-based quantitation approach (16, 27–30) combines a pattern recognition algorithm with peptide identification results to align shifted peptides for quantitation. The pioneering accurate mass and time tag strategy (27) takes advantage of very sensitive, highly accurate mass measurement instruments with a wide dynamic range, e.g. FTICR-MS and TOF-MS, for quantitation analysis. PEPPeR (16) and SuperHirn (28) apply pattern recognition algorithms to align peaks and use the peptide identification results as landmarks to improve the alignment. However, because these methods still align all peaks in MS¹ data, they suffer the same computation time problem as pattern-based methods.To resolve the computation-intensive problem in the hybrid approach, we present a fully automated software system, called IDEAL-Q, for label-free quantitation including differential protein expression and protein modification analysis. Instead of using computation-intensive pattern recognition methods, IDEAL-Q uses a computation-efficient fragmental regression method for identity-based alignment of all confidently identified peptides in a local elution time domain. It then performs peptide cross-assignment by mapping predicted elution time profiles across multiple LC-MS experiments. To improve the quantitation accuracy, IDEAL-Q applies three validation criteria to the detected peptide peak clusters to filter out noisy signals, false peptide peak clusters, and co-eluting peaks. Because of the above key features, i.e. fragmental regression and stringent validation, IDEAL-Q can substantially increase the number of quantifiable proteins as well as the quantitation accuracy compared with other extracted ion chromatogram (XIC)¹ -based tools. Notably, to accommodate different designs, IDEAL-Q supports various built-in normalization procedures, including normalization based on multiple internal standards, to eliminate systematic biases. It also adapts to different fractionation strategies for in-depth proteomics profiling.We evaluated the performance of IDEAL-Q on three levels: 1) quantitation of a standard protein mixture, 2) large scale proteome quantitation using replicate cell lysate, and 3) proteome scale quantitative analysis of protein expression that incorporates an additional fractionation step. We demonstrated that IDEAL-Q can quantify up to 89% of identified proteins (703 proteins) in the replicate THP-1 cell lysate. Moreover, by manual validation of the entire 11,940 peptide ions corresponding to 1,990 identified peptides, 93% of peptide ions were accurately quantified. In another experiment on replicate data containing huge chromatographic shifts obtained from two independent LC-MS/MS instruments, IDEAL-Q demonstrated its robust quantitation and its ability to rectify such shifts. Finally, we applied IDEAL-Q to the THP-1 replicate experiment with an additional SDS-PAGE fractionation step. Equipped with user-friendly visualization interfaces and convenient data output for publication, IDEAL-Q represents a generic, robust, and comprehensive tool for label-free quantitative proteomics.     

Integrated In Silico–In Vitro Identification and Characterization of the SH3-Mediated Interaction between Human PTTG and its Cognate Partners in Medulloblastoma

The human pituitary tumor-transforming gene is an oncogenic protein which serves as a central hub in the cellular signaling network of medulloblastoma. The protein contains two vicinal PxxP motifs at its C terminus that are potential binding sites of peptide-recognition SH3 domains. Here, a synthetic protocol that integrated in silico analysis and in vitro assay was described to identify the SH3-binding partners of pituitary tumor-transforming gene in the gene expression profile of medulloblastoma. In the procedure, a variety of structurally diverse, non-redundant SH3 domains with high gene expression in medulloblastoma were compiled, and their three-dimensional structures were either manually retrieved from the protein data bank database or computationally modeled through bioinformatics technique. The binding capability of these domains towards the two PxxP-containing peptides m1p: ¹⁶¹LGPPSPVK¹⁶⁸ and m2p: ¹⁶⁸KMPSPPWE¹⁷⁵ of pituitary tumor-transforming gene were ranked by structure-based scoring and fluorescence-based assay. Consequently, a number of SH3 domains, including MAP3K and PI3K, were found to have moderate or high affinity for m1p and/or m2p. Interestingly, the two overlapping peptides exhibits a distinct binding profile to these identified domain partners, suggesting that the binding selectivity of m1p and m2p is optimized across the medulloblastoma expression spectrum by competing for domain candidates. In addition, two redesigned versions of m1p peptide ware obtained via a structure-based rational mutation approach, which exhibited an increased affinity for the domain as compared to native peptide.     

Cushing’s Disease and Pregnancy: Case Report and Literature Review

ObjectiveTo describe a patient with untreated Cushing’s disease who had 2 spontaneous pregnancies that resulted in healthy babies on both occasions.MethodsWe present a case report with clinical, laboratory, and imaging data and discuss the literature pertaining to pregnancy in patients with Cushing’s syndrome.ResultsA 28-year-old woman came to our endocrinology clinic with a 1-year history of symptoms and signs of Cushing’s syndrome. An elevated 24-hour urinary cortisol excretion and an unsuppressed 1-mg overnight dexamethasone test confirmed the diagnosis. On her next visit, she reported a confirmed pregnancy, which ultimately resulted in the birth of a normal child. Further work-up subsequently showed 2 elevated 24-hour urinary cortisol values, loss of diurnal variation, and an elevated corticotropin level. There was lack of suppression on low-dose and high-dose overnight dexamethasone suppression tests. Magnetic resonance imaging of the pituitary showed normal findings. Inferior petrosal sinus sampling was recommended, but she declined the procedure. The patient returned 3 years later for reevaluation, at which time she reported the birth of another healthy child by cesarean delivery 10 months previously. There were no reported maternal or fetal complications. Examination at this visit revealed buccal pigmentation and proximal myopathy. Investigations showed increased 24-hour urinary cortisol excretion and serum corticotropin levels. Repeated magnetic resonance imaging disclosed a microadenoma on the right side of the pituitary. Unstimulated inferior petrosal sinus sampling showed a gradient to the right; thus, the presence of pituitary-dependent Cushing’s disease was confirmed.ConclusionOur case demonstrates that patients with pituitary-dependent Cushing’s disease are more likely to have spontaneous pregnancies with favorable outcomes than are patients with Cushing’s syndrome due to other causes. Our patient, despite having Cushing’s disease for more than 7 years, had 2 uneventful pregnancies that produced normal healthy children, without exacerbation of her disease during pregnancy. (Endocr Pract. 2007;13: 296-299)     

An Unusual Variant of Cushing Syndrome

ObjectiveTo discuss the initial clinical manifestations of primary pigmented nodular adrenocortical disease.MethodsWe present a case report of a 4-year-old boy who had the classic clinical features of Cushing syndrome. Results of hormonal investigations are reviewed, and histopathologic findings are illustrated.ResultsInvestigations revealed adrenocorticotropic hormone (corticotropin)-independent Cushing syndrome. Findings on magnetic resonance imaging of the pituitary gland and abdomen were within normal limits. The patient underwent bilateral adrenalectomy. The histopathologic features were consistent with primary pigmented nodular adrenocortical disease.ConclusionPrimary pigmented nodular adrenocortical disease should be suspected in patients with corticotropin- independent Cushing syndrome who have normal findings on adrenal imaging. (Endocr Pract. 2008;14:717-720)     

PROMIS Versus Legacy Patient-Reported Outcome Measures for Sports Medicine Patients Undergoing Arthroscopic Knee,Shoulder, and Hip Interventions: A Systematic Review

BackgroundThe Patient-Reported Outcomes Measurement Information System (PROMIS®)^ǂ was designed to monitor the global wellbeing of patients, with the Physical Function Computer-Adaptive Test (PF-CAT) component focused specifically on functional outcome. PROMIS aims for increased item-bank accuracy, lower administrative burden, and decreased floor and ceiling effects compared to legacy patient-reported outcome measures (PROMs). Our primary research outcomes focused on sports medicine surgical populations, which may skew younger or have wide-ranging functional statuses. Specifically, for this population, we questioned if PROMIS PF-CAT was equal to legacy PROMs in (1) construct validity and (2) convergent/divergent validities; and superior to legacy PROMs with respect to (3) survey burden and (4) floor and ceiling effects.MethodsSearches were performed in April 2019 in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, utilizing PubMed, Cochrane Central, and Embase databases for Level I-III evidence. This resulted in 541 records, yielding 12 studies for inclusion. PROM data was available for patients undergoing arthroscopic orthopaedic procedures of the knee, shoulder, and hip. Measures of construct validity, convergent/divergent validity, survey burden, and floor/ceiling effects were evaluated for PROMIS PF-CAT versus legacy PROMs.ResultsPROMIS PF-CAT demonstrated excellent or excellent-good correlation with legacy PROMS for physical function and quality of life for patients undergoing arthroscopic interventions of the knee, shoulder, and hip. Compared to legacy PROM instruments, PROMIS PF-CAT demonstrated the lowest overall survey burden and had the lowest overall number of floor or ceiling effects across participants.ConclusionPROMIS PF-CAT is an accurate, efficient evaluation tool for sports medicine surgical patients. PROMIS PF-CAT strongly correlates with legacy physical function PROMs while having a lower test burden and less incidence of floor and ceiling effects. PROMIS PF-CAT may be an optimal alternative for traditional physical function PROMs in sports medicine patients undergoing arthroscopic procedures. Further studies are required to extend the generalizability of these findings to patients during postoperative timepoints after shoulder and hip interventionsLevel of Evidence: III     

Two Arginine-Glutamate Ionic Locks Near the Extracellular Surface of FFAR1 Gate Receptor Activation

Activation of a number of class A G protein-coupled receptors (GPCRs) is thought to involve two molecular switches, a rotamer toggle switch within the transmembrane domain and an ionic lock at the cytoplasmic surface of the receptor; however, the mechanism by which agonist binding changes these molecular interactions is not understood. Importantly, 80% of GPCRs including free fatty acid receptor 1 (FFAR1) lack the complement of amino acid residues implicated in either or both of these two switches; the mechanism of activation of these GPCRs is therefore less clear. By homology modeling, we identified two Glu residues (Glu-145 and Glu-172) in the second extracellular loop of FFAR1 that form putative interactions individually with two transmembrane Arg residues (Arg-183(5.39) and Arg-258(7.35)) to create two ionic locks. Molecular dynamics simulations showed that binding of agonists to FFAR1 leads to breakage of these Glu-Arg interactions. In mutagenesis experiments, breakage of these two putative interactions by substituting Ala for Glu-145 and Glu-172 caused constitutive receptor activation. Our results therefore reveal a molecular switch for receptor activation present on the extracellular surface of FFAR1 that is broken by agonist binding. Similar ionic locks between the transmembrane domains and the extracellular loops may constitute a mechanism common to other class A GPCRs also.G protein-coupled receptors (GPCRs)³ are important components of signal transduction machineries that regulate many physiological processes. They are also important as targets for therapeutic agents; a large percentage of drugs in the marketplace are GPCR ligands or modulators. Knowledge of structure-function relationships of GPCRs has been gained through many pharmacological, biochemical, and biophysical studies, and has been used extensively to enhance the discovery of GPCR ligands that have been developed into therapeutically useful agents (1–3). Knowledge of the molecular details of ligand-receptor interaction and of the mechanism of receptor activation will also likely improve efforts to identify agonists with better potency and efficacy. Tan et al. (3) have recently reported their design of agonists with higher potency and efficacy for the trace amine receptor 1 based on the rotamer toggle switch model of receptor activation that is thought to operate in a number of class A GPCRs. The rotamer toggle switch typically involves the aromatic residues Trp and Phe within transmembrane helix 6 (TMH6) of GPCRs. During agonist-mediated receptor activation or in constitutively active receptors, the dihedral angle on the side chain of these residues is predicted to be rotated compared with the inactive state and thereby triggers a movement of TMH6 away from TMH3 (e.g. Ref. 4). It is also thought that an ionic lock between an Arg residue in TMH3 and a Glu in TMH6 near the cytoplasmic surface of some GPCRs holds the receptor in the inactive conformation and that receptor activation is accompanied by breakage of the ionic bond when agonist binds; the ionic lock may also be broken by receptor mutation (e.g. Ref. 5). Although these models of receptor activation have been proposed for a number of class A GPCRs, it is not certain how generally this hypothesis can be applied across all members of this GPCR class. From the alignment of 372 sequences of human GPCRs, we noted that about 80% of GPCRs do not have the putative residues that play a role in either the rotamer toggle switch, the ionic lock, or both. For these receptors, the interaction responsible for regulating interconversion between inactive and active receptor conformations therefore remains unknown.The free fatty acid receptor 1 (FFAR1) is a G_q-coupled, class A GPCR-activated endogenously by free fatty acids, with a preference for medium-to-long chain fatty acids (C8–12) (reviewed in Ref. 6). The receptor has been suggested to be a potential target for treatment of type 2 diabetes, as offered by the action of agonists to potentiate glucose-stimulated insulin release (reviewed in Refs. 7, 8). Several groups, including ours, have reported the discovery of novel small molecule ligands for FFAR1 (9–13). Most of these compounds were identified by high-throughput screening followed by chemical optimization (10–12). Our group has delineated the ligand-binding pocket of FFAR1 (14, 15) and used the information as a rational approach to ligand discovery by means of virtual screening (13). The mechanism of FFAR1 activation; however, remains unknown especially because this receptor does not contain either the rotamer toggle switch or the ionic lock between TMHs 3 and 6.We have previously identified nine residues in the ligand-binding pocket of FFAR1 that are important for ligand recognition and/or receptor activation (14). In particular, two Arg residues (Arg-183(5.39)⁴ and Arg-258(7.35)) and an Asn residue (Asn-244(6.55)) in the TMHs coordinate the carboxylate head group of the naturally occurring agonist linoleate and the synthetic agonist GW9508. In the present study, by a collaborative effort using computational modeling and receptor mutagenesis, we report the identification of Glu-172 in the second extracellular loop (ECL2) of FFAR1 that may function together with Arg-183(5.39) and Arg-258(7.35) as locks to control activation of the receptor. Our results suggest that these ionic locks at the extracellular surface hold the receptor in an inactive state. Agonists, through interaction with the arginine residues, may break the arginine-glutamate interactions thereby allowing the receptor to adopt an active conformation. Therefore, our results have provided insights into the mechanism of activation of class A GPCRs that function in a manner not explicable by the more well-studied models.     

Venous Sampling for Cushing Disease: Comparison of Internal Jugular Vein and Inferior Petrosal Sinus Sampling

Objective: Because magnetic resonance imaging (MRI) fails to detect many adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas, inferior petrosal sinus sampling (IPSS) is considered the gold standard to differentiate Cushing disease (CD) from ectopic ACTH secretion syndrome (EAS). Some authors have suggested internal jugular vein sampling (IJVS) as an alternative to IPSS.Methods: We simultaneously compared IJVS to IPSS in 30 consecutive patients referred for ACTH-dependent Cushing syndrome and equivocal MRI exams. Five sites were simultaneously sampled in each patient (right and left IPS, right and left IJV, and femoral vein) before and after the administration of corticotrophin-releasing hormone or desmopressin. The test was considered consistent with CD when the IPS to peripheral ratio was >2 at baseline or >3 after stimulus and the IJV to peripheral ratio was >1.7 at baseline or >2 after stimulus.Results: In 27 of 30 patients, IPSS results were consistent with a central source of ACTH. Two of the other 3 patients had EAS (one lung carcinoid and one occult), and 1 patient had pathology-proven CD. The sensitivity of IPSS was 96.4%. Only 64.2% of these patients had results meeting criteria for a central source of ACTH by IJVS criteria. Twenty patients with centralizing IPPS have undergone pituitary surgery. Of these, the central origin of excessive ACTH was confirmed with certainty in 16 patients. Among these 16 patients, the IPSS sensitivity was 93.8%, whereas 5 patients had false-negative IJVS (68.7% sensitivity).Conclusion: These results do not support the routine use of IJVS in establishing if the pituitary is the source of excessive ACTH.Abbreviations:ACTH = adrenocorticotropic hormoneCD = Cushing diseaseCRH = corticotrophin-releasing hormoneCS = Cushing syndromeDDAVP = desmopressinEAS = ectopic ACTH secretionIJVS = internal jugular vein samplingIPSS = inferior petrosal sinus samplingJVS = jugular venous samplingMRI = magnetic resonance imaging     

The Role of Minimally Invasive Surgical Techniques in the Management of Large-gland Benign Prostatic Hypertrophy

Lower urinary tract symptoms (LUTS) secondary to benign prostatic hypertrophy (BPH) are among the most common medical issues for aging men. Population-based studies suggest that 13.8% of men in their 40s and more than 40% of men over age 60 have BPH. When LUTS are refractory to medical therapy and bothersome enough to warrant surgical intervention, transurethral resection of the prostate and open simple prostatectomy have been the historical reference-standard procedures for decades. Both procedures are highly effective and offer durable improvements in urinary functional outcomes. However, they also have the potential for considerable perioperative complications and morbidity. In an effort to limit surgical morbidity, a variety of minimally invasive surgical techniques to treat BPH have been introduced. Herein we present a comprehensive, evidence-based review of the efficacy and safety profile of modern minimally invasive treatments for large-gland BPH.Key words: Benign prostatic hypertrophy, Lower urinary tract symptoms, GreenLight photovaporization, Holmium laser enucleation of the prostate (HoLEP), Robotic simple prostatectomyLower urinary tract symptoms (LUTS) secondary to benign prostatic hypertrophy (BPH) are among the most common medical issues for aging men. Population-based studies suggest that 13.8% of men in their 40s and more than 40% of men over age 60 have BPH.¹ When LUTS are refractory to medical therapy and bothersome enough to warrant surgical intervention, transurethral resection of the prostate (TURP) and open simple prostatectomy (SP) have been the historical reference-standard procedures for prostates < 80 g and ≥ 80 to 100 g, respectively, for decades.²Both procedures are highly effective and offer durable improvements in urinary functional outcomes.^3–5 However, they also have the potential for considerable perioperative complications and morbidity. A recent prospective study of more than 10,654 patients undergoing TURP reported an overall short-term morbidity rate of 11.1%. Among the most common complications reported were surgical reoperation (5.6%), transfusions (2.9%), and transurethral resection syndrome (1.4%).⁶ Furthermore, the risks of both complications and mortality increased with gland size.⁶ The morbidity of open SP is even higher, with 7.5% of patients requiring transfusions and 3.7% requiring surgical intervention for severe bleeding, even in contemporary series.⁷In an effort to limit surgical morbidity, a variety of minimally invasive surgical techniques to treat BPH have been introduced. Although a large body of research exists investigating the overall safety and efficacy of such procedures, there remains a paucity of evidence regarding the safety and efficacy of these procedures in the management of large prostates ≥ 80 g in size (Figure 1).Open in a separate windowFigure 1Example of large-gland benign prostatic hyperplasia on computed tomography scan in the axial (above) and coronal (below) planes.