Therapy for CAG-repeat diseases?

Suppression of aggregate formation and apoptosis by transglutaminase inhibitors in cells expressing truncated DRPLA protein with an expanded polyglutamine stretchIgarashi, S. et al. (1998)Nat. Genet. 18, 111–117     

Is Cardiac Resynchronisation Therapy Proarrhythmic?

It is well established that cardiac resynchronisation therapy (CRT) using biventricular pacing prolongs survival by its effects on pump failure. The rate of sudden cardiac death in patients undergoing CRT, however, remains high. Animal and human studies have shown that reversal of normal sequence of myocardial activation during epicardial pacing, as applied during CRT, increases the transmural dispersion of repolarisation (TDR), a substrate for ventricular arrhythmias. Cohort studies in humans suggest that CRT has a differential effect on the arrhythmogenic substrate, antiarrhythmic in some and proarrhythmic in others. This review the focuses on the possibility that CRT may, under certain circumstances, promote arrhythmogenesis.     

Is Liraglutide A Useful Addition to Diabetes Therapy?

ObjectiveTo evaluate liraglutide as an antidiabetic agent.MethodsThe pertinent English-language medical literature was reviewed for the period from 1985 to April 2010 with use of data from MEDLINE.ResultsLiraglutide is a glucagonlike peptide-1 receptor analogue that stimulates insulin secretion, reduces postprandial glucagon release, causes a mild delay in gastric emptying, and may slightly decrease appetite. Mean reductions in hemoglobin A1c levels with liraglutide therapy range from 1.0% to 1.5% in comparison with baseline and are 1.0% and 1.3% in comparison with placebo. Head-to-head trials suggest that liraglutide may be more effective than glimepiride, rosiglitazone, insulin glargine, and exenatide. Some of the previous trials, however, are limited by use of submaximal doses of comparator drugs and an open-label design. The use of liraglutide is associated with a mean weight loss of 0.2 to 3.2 kg relative to baseline and 0.1 to 2.6 kg relative to placebo. Liraglutiderelated hypoglycemia is generally mild, but its incidence and severity substantially increase in conjunction with sulfonylureas. Gastrointestinal adverse effects such as nausea, diarrhea, or vomiting occurred in 44% to 56% of patients who received liraglutide versus 17% to 19% with placebo. Premature withdrawal from trials occurred in 4% to 15% of liraglutide-treated patients (mainly attributable to gastrointestinal adverse effects), in comparison with 3% to 5% of those receiving placebo.ConclusionThe 2 main advantages of liraglutide are mild degrees of weight loss and hypoglycemia. Important limitations, however, are the frequent occurrence of gastrointestinal adverse effects, the requirement of subcutaneous injection once daily, and the lack of long-term efficacy and safety data. Liraglutide may be a useful add-on therapy in patients with type 2 diabetes uncontrolled with metformin, when hypoglycemia, weight gain, or both are major concerns. (Endocr Pract. 2010;16:1028-1037)     

Does Testosterone Therapy Increase the Risk of Prostate Cancer?

ObjectiveTo review factors affecting use of testosterone therapy for hypogonadism including the persistent controversial link between testosterone therapy and prostate cancer.MethodsWe reviewed studies investigating the relationship between testosterone therapy and prostate cancer progression and summarized strategies for hypogonadism management and prostate monitoring.ResultsTrials of up to 36 months in length and longitudinal studies consistently fail to demonstrate an increased prostate cancer risk associated with increased testosterone levels. No evidence of an associated relationship between exogenous testosterone therapy and prostate cancer has emerged from clinical trials or adverse event reports. It does not appear that exogenous testosterone accumulates in the prostate or provokes major biologic change in the prostate gland. In addition, preliminary evidence indicates that low endogenous testosterone may confer an increased risk of prostate cancer.ConclusionsMounting evidence demonstrates that there is a lack of association between testosterone therapy and prostate cancer progression. Testosterone therapy may be prescribed for men for whom it was once not considered. Careful monitoring of patients with hypogonadism who are receiving testosterone therapy is imperative. Well-designed, large-scale prospective clinical trials are necessary to adequately address prostate safety in hypogonadal men receiving testosterone therapy. (Endocr Pract. 2008;14:904-911)     

Shh Signaling and Pancreatic Cancer: Implications for Therapy?

Hedgehog signaling has been implicated in the development of several human cancers, including small cell lung carcinomas, medulloblastomas, basal cell carcinomas, and digestive tract tumors. Elevated levels of pathway components are observed in pancreatic ductal adenocarcinoma (PDAC) precursor lesions, and these levels increase further as lesions progress to more advanced stages. Yet the mechanisms by which hedgehog signaling contributes to pancreatic tumorigenesis were poorly understood. We recently published results showing that activated hedgehog signaling enhances the proliferation and survival of pancreatic duct epithelial cells, the presumptive target cells for PDAC development. We also demonstrated that sonic hedgehog (Shh) expression, in cooperation with loss of the Trp53 and Ink4a/Arf tumor suppressor loci, was sufficient to initiate the formation of early pancreatic lesions. Furthermore, Shh signaling enhanced K-Ras-mediated pancreatic tumorigenesis and reduced the dependence of tumor cells on the sustained activation of Ras-stimulated signaling pathways. Here we discuss the significance of these findings and the implications for therapy.     

Does Bone-targeted Therapy Benefit Patients with Metastatic Renal Cell Carcinoma?

INTRODUCTION: In metastatic renal cell carcinoma (mRCC), the bone is the second most common site of metastasis and is associated with increased morbidity and poorer quality of life. Bone-targeted therapies (BTTs) such as denosumab and zoledronic acid may prevent skeletal-related events (SREs). However, the benefit of BTTs in combination with tyrosine kinase inhibitors (TKIs) remains unclear. METHODS: We performed a retrospective chart review at the Urologic Cancer Centre for Research and Innovation. Patients with mRCC were included if they had bone metastases treated with TKIs between 2010 and 2017. Our primary outcome was overall survival (OS), defined as the time elapsed from clinical diagnosis of mRCC to death, and modelled using the Kaplan–Meier method. Secondary outcomes included the median time to SRE and the analysis of prognostic factors of OS using Cox proportional hazards regression. RESULTS: In total, 230 patients with mRCC were identified; of which, 46 had bone metastases treated with TKIs and were included in the study (TKI-only, n = 37; TKI + BTT, n = 9). In the TKI + BTT cohort, patients received either denosumab (n = 5) or zoledronic acid (n = 4). At the time of analysis, 63% of patients were deceased. We observed an OS trend favouring the TKI + BTT cohort (13.8 months [95% confidence interval {CI}: 12.3–15.2] vs. 29.6 months [95% CI: 7.2–51.9], hazard ratio [HR]: 1.66 (95% CI: 0.62–4.45), P = 0.31). When patients in the TKI + BTT cohort were stratified by type of therapy (denosumab or zoledronic acid), the median time to SRE was similar between the groups (4.2 months [95% CI: 2.28–6.14] vs. 2.2 months [95% CI: not available], P = 0.71]. On univariate or multivariate analysis, it was found that age, gender, comorbidities, International metastatic RCC database consortium (IMDC) prognostic group and pathologic tumour grade were not significant predictors of worse OS. Pathologic stage 3 or 4 was an independent predictor of worse OS (HR: 5.8, 95% CI: 1.41–24.03, P = 0.015). CONCLUSION: BTTs may have a continued role in the era of targeted therapy and immunotherapy. Further prospective data are required to validate our findings.     

Natural Products: An Alternative to Conventional Therapy for Dermatophytosis?

The increased incidence of fungal infections, associated with the widespread use of antifungal drugs, has resulted in the development of resistance, making it necessary to discover new therapeutic alternatives. Among fungal infections, dermatophytoses constitute a serious public health problem, affecting 20–25 % of the world population. Medicinal plants represent an endless source of bioactive molecules, and their volatile and non-volatile extracts are clearly recognized for being the historical basis of therapeutic health care. Because of this, the research on natural products with antifungal activity against dermatophytes has considerably increased in recent years. However, despite the recognized anti-dermatophytic potential of natural products, often advantageous face to commercial drugs, there is still a long way to go until their use in therapeutics. This review attempts to summarize the current status of anti-dermatophytic natural products, focusing on their mechanism of action, the developed pharmaceutical formulations and their effectiveness in human and animal models of infection.     

Does Combination T4 And T3 Therapy Make Sense?

ObjectiveTo evaluate the existing evidence regarding the combined use of levothyroxine and liothyronine to treat hypothyroidism.MethodsEleven published randomized controlled trials evaluating the efficacy and safety of combined levo- thyroxine and liothyronine therapy for hypothyroidism were reviewed and summarized. Related basic and clinical research findings were also incorporated for perspective.ResultsAn initial randomized controlled trial reported symptomatic improvement in hypothyroid patients taking combined levothyroxine and liothyronine therapy compared with those taking levothyroxine therapy alone. Subsequently, multiple relatively small randomized controlled trials failed to demonstrate any subjective or objective benefit from combined levothyroxine and liothy- ronine therapy. A polymorphism (Thr92Ala) in the gene encoding the deiodinase 2 (D2) enzyme that converts thy- roxine to triiodothyronine in the brain was later identified in about 16% of hypothyroid persons. This polymorphism may impair brain deiodinase activity in the presence of low brain thyroxine levels. One randomized controlled trial found that patients with the D2 Thr92Ala polymorphism had more baseline symptoms than those with the wild type D2 and experienced significantly greater symptomatic improvement in response to combined levothyroxine and liothyronine therapy.ConclusionsMost hypothyroid patients experience rapid symptomatic relief after institution of levothyroxine replacement therapy, but persistent symptoms remain in some despite what appears to be adequate levothyroxine therapy with normalization of the serum thyrotropin level. A thorough investigation is warranted in these patients to detect and treat other responsible lifestyle issues, medical conditions, and endocrine conditions. A subset of hypo- thyroid patients has a polymorphism in the gene encoding the D2 enzyme that may prevent full resolution of symp- toms with levothyroxine therapy alone; these patients may benefit from combination levothyroxine and liothyronine therapy. (Endocr Pract. 2012;18:750-757)     

Capillary Regeneration in Scleroderma: Stem Cell Therapy Reverses Phenotype?

Background

Scleroderma is an autoimmune disease with a characteristic vascular pathology. The vasculopathy associated with scleroderma is one of the major contributors to the clinical manifestations of the disease.

Methodology/Principal Findings

We used immunohistochemical and mRNA in situ hybridization techniques to characterize this vasculopathy and showed with morphometry that scleroderma has true capillary rarefaction. We compared skin biopsies from 23 scleroderma patients and 24 normal controls and 7 scleroderma patients who had undergone high dose immunosuppressive therapy followed by autologous hematopoietic cell transplant. Along with the loss of capillaries there was a dramatic change in endothelial phenotype in the residual vessels. The molecules defining this phenotype are: vascular endothelial cadherin, a supposedly universal endothelial marker required for tube formation (lost in the scleroderma tissue), antiangiogenic interferon α (overexpressed in the scleroderma dermis) and RGS5, a signaling molecule whose expression coincides with the end of branching morphogenesis during development and tumor angiogenesis (also overexpressed in scleroderma skin. Following high dose immunosuppressive therapy, patients experienced clinical improvement and 5 of the 7 patients with scleroderma had increased capillary counts. It was also observed in the same 5 patients, that the interferon α and vascular endothelial cadherin had returned to normal as other clinical signs in the skin regressed, and in all 7 patients, RGS5 had returned to normal.

Conclusion/Significance

These data provide the first objective evidence for loss of vessels in scleroderma and show that this phenomenon is reversible. Coordinate changes in expression of three molecules already implicated in angiogenesis or anti-angiogenesis suggest that control of expression of these three molecules may be the underlying mechanism for at least the vascular component of this disease. Since rarefaction has been little studied, these data may have implications for other diseases characterized by loss of capillaries including hypertension, congestive heart failure and scar formation.     

Targeted Gene Therapy of Xeroderma Pigmentosum Cells Using Meganuclease and TALEN?

Xeroderma pigmentosum group C (XP-C) is a rare human syndrome characterized by hypersensitivity to UV light and a dramatic predisposition to skin neoplasms. XP-C cells are deficient in the nucleotide excision repair (NER) pathway, a complex process involved in the recognition and removal of DNA lesions. Several XPC mutations have been described, including a founder mutation in North African patients involving the deletion of a TG dinucleotide (ΔTG) located in the middle of exon 9. This deletion leads to the expression of an inactive truncated XPC protein, normally involved in the first step of NER. New approaches used for gene correction are based on the ability of engineered nucleases such as Meganucleases, Zinc-Finger nucleases or TALE nucleases to accurately generate a double strand break at a specific locus and promote correction by homologous recombination through the insertion of an exogenous DNA repair matrix. Here, we describe the targeted correction of the ΔTG mutation in XP-C cells using engineered meganuclease and TALEN™. The methylated status of the XPC locus, known to inhibit both of these nuclease activities, led us to adapt our experimental design to optimize their in vivo efficacies. We show that demethylating treatment as well as the use of TALEN™ insensitive to CpG methylation enable successful correction of the ΔTG mutation. Such genetic correction leads to re-expression of the full-length XPC protein and to the recovery of NER capacity, attested by UV-C resistance of the corrected cells. Overall, we demonstrate that nuclease-based targeted approaches offer reliable and efficient strategies for gene correction.     

Is DL-Fenfluramine a Potentially Helpful Drug Therapy in Overweight Adolescent Subjects?

We have studied the therapeutic effects of two different doses (30 mg and 60 mg, twice daily) of DL-fen-fluramine (DL-F) in, respectively, prepuberal (11–13 years old) and adolescent subjects (14–17 years old). Sixty-eight obese subjects were recruited for this study (22 boys, 36 girls, aged 10–17 years old) with body mass index ranging from 24.5 to 44.0 kg/m², absolute weight ranging from 37.0 to 119.5 kg and % over IBW ranging from 122% to 260%. Results were compared to a placebo treated group of obese adolescent patients (n=17), 6 boys and 11 girls, aged 10–17 years old, BMI ranging from 26–44 kg/m², absolute weight 53.1 to 96.5 kg, and with 129% to 253% over IBW. In the DL-F-treated subjects most patients (n=41) had a continuous weight loss during 12 months but 27 individuals were unable to lose any additional weight after the initial 6 months of the trial. Taken together 65% of all patients lost weight during DL-F treatment (12 months) whereas only 17.4% of the placebo group lost a significant (>10% BMI) amount of excess weight. Also the placebo group had a higher withdrawal rate (57%) as compared with the DL-F-treated group (24%). There was a significant (p<0.05) decrease of the mean & SD of the BMI (at 6 and 12 months of therapy). No significant change of the BMI was observed for control group. Minor adverse side effects consisted of a brief period of drowsiness and dry mouth. Our findings indicated that the continuous administration of DL-Fenfluramine might help obese adolescent subjects adhere to a diet and to maintain the weight loss achieved without major or harmful adverse effects .     

High-dose Insulin Therapy: is it Time for U-500 Insulin?

ObjectiveTo provide an overview of U-500 regular insulin action, review published clinical studies with U- 500 regular insulin, and offer guidance to practicing endocrinologists for identifying patients for whom U-500 regular insulin may be appropriate.MethodsThis review has been produced through a synthesis of relevant published literature compiled via a literature search (MEDLINE search of the English-language literature published between January 1969, and July 2008, related to U-500, insulin resistance, concentrated insulin, high-dose insulin, insulin pharmacokinetics, and diabetes management) and the authors’ collective clinical experience.ResultsThe obesity epidemic is contributing to an increase in the prevalence of type 2 diabetes, as well as to increasing insulin requirements in insulin-treated patients. Many of these patients exhibit severe insulin resistance, manifested by daily insulin requirements of 200 units or greater or more than 2 units/kg. Delivering an appropriate insulin volume to these patients can be difficult and inconvenient and may be best accomplished with U-500 regular insulin by multiple daily injections or with continuous subcutaneous insulin infusion, rather than with standard U-100 insulin. Implementation of U-500 regular insulin in patients previously on other insulin formulations is described with a treatment algorithm covering dosage requirements ranging from 150 to more than 600 units per day on the basis of the authors’ experience.ConclusionRegimen conversion of appropriately selected patients from high-dose, U-100 insulin to U-500 regular insulin therapy on the basis of the recommendations presented in this article may potentially result in improved glycemic control and lower cost. (Endocr Pract. 2009;15:71-79)     

When Should Children with HIV Infection Be Started on Antiretroviral Therapy?

Background to the debate: The advent of highly active antiretroviral therapy (HAART) dramatically improved the prognosis for both adults and children infected with HIV who had access to treatment. However, the optimal timing for initiating treatment remains controversial, particularly in children. This debate lays out the case for deferred treatment against the case for early initiation of HAART in children.     

Bright Light Therapy for Winter Depression—Is Phase Advancing Beneficial?

Bright light is the recommended treatment for winter seasonal affective disorder (SAD). Previously we showed that the antidepressant effect of morning (but not evening) light was greater than placebo after 3 weeks of treatment. Here, we determined if the magnitude and direction of circadian rhythm phase shifts produced by the bright light in the previous study were related to the antidepressant effects. Twenty-six SAD patients from the original sample of 96 had their rectal temperature continuously monitored while they participated in a placebo-controlled parallel design conducted over six winters. After a baseline week, there were three treatments for 4 weeks—morning light, evening light, or morning placebo. Bright light was produced by light boxes (?6000 lux). Placebos were sham negative ion generators. All treatments were 1.5 h in duration. Depression ratings were made weekly by blind raters. Circadian phase shifts were determined from changes in the timing of the core body temperature minimum (Tmin). Morning light advanced and evening light delayed the Tmin by about 1 h. The placebo treatment did not alter circadian phase. As the sleep schedule was held constant, morning light increased and evening light decreased the Tmin to wake interval, or phase angle between circadian rhythms and sleep. Phase advance shifts and increases in the phase angle were only weakly associated with antidepressant response. However, there was an inverted U-shaped function showing that regardless of treatment assignment the greatest antidepressant effects occurred when the phase angle was about 3 h, and that patients who moved closer to this phase angle benefited more than those who moved farther from it. However 46% of our sample had a phase angle within 30 min of this 3 h interval at baseline. So it does not appear that an abnormal phase angle can entirely account for the etiology of SAD. A majority (75%) of the responders by strict joint criteria had a phase angle within this range after treatment, so it appears that obtaining the ideal phase relationship may account for some, but not all of the antidepressant response. In any case, regardless of the mechanism for the antidepressant effect of morning light, it can be enhanced when patients sleep at the ideal circadian phase and reduced when they sleep at a more abnormal circadian phase.     

Total Body Potassium in Long-Term Frusemide Therapy: Is Potassium Supplementation Necessary?

Measurements of total body potassium (T.B.K.) were made by whole-body counting in four groups of patients receiving oral frusemide for one year. Patients in group 1 had essential hypertension and normal renal function and received 40 mg frusemide daily without potassium supplements. Patients in group 2 were similar but received oral potassium supplements for the first four months of treatment. Patients in group 3 had hypertension associated with renal disease and received 120 mg frusemide daily without potassium supplements. Patients in group 4 also had hypertension and renal impairment and in addition to 120 mg frusemide daily they received oral potassium supplements for four months. No evidence of depletion of T.B.K. was found in any of the groups after continuous treatment with frusemide for one year. It is questioned whether potassium supplementation in long term diuretic therapy with frusemide is necessary unless there is evidence of pre-existing potassium depletion or of some other factor such as cardiac failure, cirrhosis of the liver, or the nephrotic syndrome.