Mycetoma in the Sudan: An Update from the Mycetoma Research Centre,University of Khartoum,Sudan

This communication reports on the Mycetoma Research Centre of the University of Khartoum, Sudan experience on 6,792 patients seen during the period 1991–2014.The patients were predominately young (64% under 30 years old) males (76%). The majority (68%) were from the Sudan mycetoma belt and 28% were students. Madurella mycetomatis eumycetoma was the most common type (70%). In 66% of the patients the duration of the disease was less than five years, and 81% gave a history of sinuses discharging mostly black grains (78%). History of trauma at the mycetoma site was reported in 20%. Local pain was reported in 27% of the patients, and only 12% had a family history of mycetoma. The study showed that 57% of the patients had previous surgical excisions and recurrence, and only 4% received previous medical treatment for mycetoma. Other concomitant medical diseases were reported in 4% of the patients. The foot (76%) and hand (8%) were the most commonly affected sites. Less frequently affected sites were the leg and knee (7%), thigh (2%), buttock (2%) and arm and forearm (1%). Rare sites included the chest wall, head and neck, back, abdominal wall, perineum, oral cavity, tongue and eye. Multiple sites mycetoma was recorded in 135 (2%) of cases. At presentation, 37% of patients had massive lesions, 79% had sinuses, 8% had local hyper-hydrosis at the mycetoma lesion, 11% had regional lymphadenopathy, while 6% had dilated tortuous veins proximal to the mycetoma lesions. The diagnosis of mycetoma was established by combined imaging techniques and cytological, histopathological, serological tests and grain culture. Patients with actinomycetoma received a combination of antimicrobial agents, while eumycetoma patients received antifungal agents combined with various surgical excisions. Surgical excisions in the form of wide local excision, debridement or amputation were done in 807 patients, and of them 248 patients (30.7%) had postoperative recurrence. Different types of amputations were done in 120 patients (1.7%).     

Head and Neck Mycetoma: The Mycetoma Research Centre Experience

Mycetoma is a unique neglected tropical disease which is endemic in what is known as the “mycetoma belt”. The disease has many devastating impacts on patients and communities in endemic area and is characterised by massive deformity, destruction and disability. Mycetoma is commonly seen in the foot and hand and less frequent in other parts of the body. Mycetoma of the head and neck is a rarity and is associated with high morbidity and even mortality if not treated early. In this communication we report on 49 patients with head and neck mycetoma followed up at the Mycetoma Research Centre in Khartoum. Most of the reported patients had actinomycetoma and the majority were young adult males from mycetoma endemic areas in the Sudan. Most of them were students, farmers and workers. Prior to presentation the majority had long disease duration and the cause was multifactorial. Advanced disease with massive lesion, deformity and disability was the common presentation. There was no obvious history of local trauma, familial tendency or other predisposing factor identified in this group of patients. MRI and CT scan were the most accurate diagnostic tools to determine the disease extent. The treatment outcome was rather poor and characterised by low cure rate, poor outcome and high follows-up dropout. Such a gloomy outcome calls for structured and objective health education programs.     

Hand Mycetoma: The Mycetoma Research Centre Experience and Literature Review

Mycetoma is a devastating, neglected tropical disease characterised by extensive tissue involvement resulting in destruction, deformities and disabilities in the affected patients. The hand is commonly affected by mycetoma thus compromises its functionality and hinder the patient’s daily activities of living. In this communication, we report on 533 patients with hand mycetoma managed over a period of 24 years at the Mycetoma Research Centre, University of Khartoum, Khartoum, Sudan. Eumycetoma was the commonest type of mycetoma (83.3%) encountered. Males were predominately affected (69.2%) with a sex ratio of 2.2:1. The majority of the patients (84%) were young adult below the age of 40 years old at presentation. The generality of patients (86.4%) were from the Sudan mycetoma belt. Children and adolescents (28.1%), farmers (18.2%) and workers (17.4%) were more frequently affected. The majority of patients (67.4%) had disease duration of less than 5 years at presentation. The study, did not document significant history of local trauma, familial tendency, concomitant medical diseases or other predisposing cause for mycetoma in this population. Pain (23.1%) was not a disease feature in this series and 52% of patients had past surgery for mycetoma and recurrence. The right hand was affected most (60.4%), and 64% of them had small lesion at presentation. Conventional x-ray was only helpful in patients with advanced disease and the MRI accurately determined the disease extension. Cytological smears, surgical biopsies histopathological examination and grains culture were the principal diagnostic tools for causative organisms’ identification. In the present series it was difficult to determine the treatment outcome due to high patients follow up dropout.     

Mycetoma Herbal Treatment: The Mycetoma Research Centre,Sudan Experience

It is still challenging and difficult to treat patients with eumycetoma; the current treatment has many side effects and has proven to be expensive and characterized by high recurrence rate, hence the poor patients'' treatment compliance. Most of the patients are of low socio-economic status, have many financial constraints and hence, many of them rely on alternative and herbal medicine for the treatment of their disease. With this background, the current study was conducted to determine the prevalence of herbal medicine usage among patients with eumycetoma. This cross-sectional, observational, questionnaire-based study was conducted at the Mycetoma Research Center, University of Khartoum, Khartoum, Sudan. A convenience cohort of 311 patients with confirmed eumycetoma was invited to participate in the study after informed consent. The study showed that 42.4% of the study population used herbal medicine for the treatment of eumycetoma at some stage of their illness. The commonly used herbs were Moringa oleifera, Acacia nilotica, Citrullus colocynthis and Cuminum cyminum. Most of the patients claimed no benefits from the herbal treatment. Ninety one patients (29.3%) had encountered complications with herbal treatment. The high prevalence of herbal treatment encountered in the study can be explained by the patients'' dissatisfaction with the current medical therapeutic modalities. To reduce the high prevalence of herbal medicine usage, governmental control and health policies are mandatory; likewise, native healers need to be educated in that. Moringa oleifera was the commonly used herb in this study and many reports claimed medicinal properties of this tree; hence, further in-depth studies to determine the active ingredients in the different parts of the tree and its effect are required.     

Primary Adrenal Lymphoma: a Single-Center Experience

Objective: To describe the clinical presentation, biochemistry, imaging features, and treatment outcome of patients with primary adrenal lymphoma (PAL) presenting to a single tertiary care center.Methods: We performed a retrospective analysis of case records of 7 patients diagnosed with PAL between January 2011 and May 2014 at our institution in Mumbai, India.Results: Median age of presentation in our series was 48 years (range, 41 to 60 years), with a male to female ratio of 6:1. Bilateral adrenal involvement was seen in 4 of 7 patients (58%). Adrenal insufficiency (AI) was seen in 3 of the 4 patients with bilateral involvement (75%). Computed tomography showed slight to moderate contrast enhancement of adrenal masses in 4 of 5 patients (80%). Diffuse, large, B-cell lymphoma (DLBCL) was the most common immunophenotype (85%). One patient died due to rapid disease progression even before starting chemotherapy. Six patients were treated with chemotherapy and/or external beam radiotherapy. After 1 year, 2 more patients had died, whereas 4 patients were in remission.Conclusion: PAL should always be considered in differential diagnosis of bilateral adrenal mass with AI. DLBCL is the most common histologic subtype of PAL. Despite treatment, long-term prognosis of PAL remains poor.Abbreviations: AI = adrenal insufficiency B/L = bilateral CT = computed tomography DLBCL = diffuse, large, B-cell lymphoma EBRT = external beam radiotherapy ¹⁸F-FDG PET/CT= ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography PAL = primary adrenal lymphoma T/NK = T cell/natural killer cell     

Sympathetic Paraganglioma: A Single-Center Experience from Western India

Objective: Most of the Indian studies on pheochromocytoma/paraganglioma (PCC/PGL) have focused on PCC, and there is a paucity of information regarding sympathetic paraganglioma (sPGL). Here, we describe the clinical, biochemical, and imaging features of sPGL compared with PCC.Methods: This retrospective study included 75 patients with sPGL and 150 patients with PCC. Diagnosis of PCC/PGL was based on surgical histopathology, and if histopathology was not available, on biochemistry and/or radiology.Results: sPGL was more frequently detected incidentally (P = .03), normetanephrine-secreting (P<.01), and metastatic compared with PCC (P≤.01). sPGL was most commonly located in the organ of Zuckerkandl (OOZ) (49%) and infradiaphragmatic area above the OOZ (27%). Patients with mediastinal sPGL were significantly older than those with sPGL in the OOZ (P = .03). Primary tumors of metastatic sPGL were significantly larger than those without metastasis (7.8 ± 4 cm vs. 5.6 ± 3.2 cm; P = .004). Percentage arterial enhancement (PAE) >100% was seen in 98% of sPGLs.Conclusion: Incidental presentation, normetanephrine-secreting phenotype, and metastatic disease were more frequent in patients with sPGL than those with PCC. sPGL arose most commonly in the OOZ. Tumor size is an independent predictor of malignancy among sPGL patients. PAE >100% is almost a universal finding in sPGL, and its absence is a sensitive parameter to differentiate sPGL from other abdominal masses.Abbreviations: AP = arterial phase; CECT = contrast-enhanced computed tomography; CT = computed tomography; DP = delayed phase; EVP = early venous phase; FDG = fluorodeoxyglucose; fPFMN = fractionated plasma free metanephrine; HU = Hounsfield units; MIBG = metaiodobenzylguanidine; MRI = magnetic resonance imaging; OOZ = organ of Zuckerkandl; PAE = percentage arterial enhancement; PCC = pheochromocytoma; PET = positron emission tomography; PFNMN = plasma free normetanephrine; PGL = paraganglioma; PRRT = peptide receptor radionuclide therapy; PVE = percentage venous enhancement; sPGL = sympathetic paraganglioma; UP = unenhanced phase; VMA = vanillyl mandelic acid     

Mycetoma: Experience of 482 Cases in a Single Center in Mexico

Mycetoma is a chronic granulomatous disease. It is classified into eumycetoma caused by fungi and actinomycetoma due to filamentous actinomycetes. Mycetoma can be found in geographic areas in close proximity to the Tropic of Cancer. Mexico is one of the countries in which this disease is highly endemic. In this retrospective study we report epidemiologic, clinical and microbiologic data of mycetoma observed in the General Hospital of Mexico in a 33 year-period (1980 to 2013). A total of 482 cases were included which were clinical and microbiology confirmed. Four hundred and forty four cases (92.11%) were actinomycetomas and 38 cases (7.88%) were eumycetomas. Most patients were agricultural workers; there was a male predominance with a sex ratio of 3∶1. The mean age was 34.5 years old (most ranged from 21 to 40 years). The main affected localization was lower and upper limbs (70.74% and 14.52% respectively). Most of the patients came from humid tropical areas (Morelos, Guerrero and Hidalgo were the regions commonly reported). The main clinical presentation was as tumor-like soft tissue swelling with draining sinuses (97.1%). Grains were observed in all the cases. The principal causative agents for actinomycetoma were: Nocardia brasiliensis (78.21%) and Actinomadura madurae (8.7%); meanwhile, for eumycetomas: Madurella mycetomatis and Scedosporium boydii (synonym: Pseudallescheria boydii) were identified. This is a single-center, with long-follow up, cross-sectional study that allows determining the prevalence and characteristics of mycetoma in different regions of Mexico.     

Predictors of Post-operative Mycetoma Recurrence Using Machine-Learning Algorithms: The Mycetoma Research Center Experience

Post-operative recurrence in mycetoma after adequate medical and surgical treatment is common and a serious problem. It has health, socio-economic and psychological detrimental effects on patients and families. It is with this in mind, we set out to determine the predictors of post-operative recurrence in mycetoma. The study included 1013 patients with Madurella mycetomatis causing eumycetoma who underwent surgical excision at the Mycetoma Research Centre, Khartoum, Sudan in the period 1991–2015. The clinical records of these patients were reviewed and relevant information was collected using a pre-designed data collection sheet. The study showed, 276 patients (27.2%) of the studied population developed post-operative recurrence, 217 were males (78.6%) and 59 were females (21.4%). Their age ranged between 5 to 70 years with a mean of 32 years. The disease duration at presentation ranged between 2 months and 17 years. The majority of the patients 118 (42.8%) had mycetoma of 1 year duration. In this study, students were the most affected; 105 (38%) followed by workers 70 (25.4%), then farmers 48(17.3%). The majority of the patients were from the Central Sudan 207 (75%), Western Sudan 53 (19.2%) while 11 patients (4%) were from the Northern part. Past history of surgical intervention performed elsewhere was reported in 196 patients (71.1%). Family history of mycetoma was reported in 50 patients (18.1%). The foot was the most affected site, 245 (88.7%), followed by the hand seen in 19 (6.8%) patients and 44 (4.5%) had different sites involvement. Most of the patients 258 (93.5%) had wide local surgical excisions while 18 had major amputation. The model predicted that the certain groups have a high risk of recurrence, and these include patients with disease duration greater than 10 years and extra-pedal mycetoma. Patients with disease duration between [5–10] years, with pedal mycetoma, who had previous surgery, with positive family history and underwent wide local surgical excision. Patients with disease duration [5–10] years, with pedal mycetoma, had previous surgery, with no family history but presented with a disease size (> 10 cm), were non- farmers and underwent wide local surgical excision. Other groups are patients with disease duration (≤5 years), with pedal mycetoma, age <59 years, living in the Western /Eastern / Southern regions of the Sudan and with positive family history and had wide local surgical excision. Also included patients with disease duration (≤5 years), with pedal mycetoma, aged <59 years, living in the northern or central region, with no family history but presented with a disease size >10 cm, working as farmers or students and underwent wide local surgical excision. In conclusion, these groups of patients need special care to reduce the incidence of post-operative recurrence with its morbidity and detrimental consequences. In depth studies for the other predisposing factors for post-operative recurrence such as genetic, immunological and environmental factors are needed.     

Ectopic Acth-Secreting Syndrome: A Single-Center Experience

ObjectiveEctopic adrenocorticotropic hormone (ACTH)-secreting syndrome (EAS) is a rare cause of ACTH-dependent endogenous hypercortisolism. The objective of this study was to analyze clinical, biochemical, and imaging characteristics; management strategies; and outcomes of EAS patients.MethodWe screened the records (1993-2012) of ACTH-dependent endogenous hypercortisolism cases managed at a tertiary care center.ResultsOf the 218 patients, 17 were diagnosed with EAS. The median 8:00 AM serum cortisol was 36 μg/dL (11.4-82.7 μg/dL), and the median basal plasma ACTH was 156 pg/mL (53.5-468 pg/mL). Notably, ACTH levels below 100 pg/mL were found in 4 patients. Suspicious microadenoma was found on magnetic resonance imaging (MRI) of the pituitary in 5 patients, and all of them underwent transsphenoidal surgery (TSS). Inferior petrosal sinus sampling (IPSS) was performed in 8 patients, and the results were suggestive of a peripheral source in all 8. Computed tomography (CT) localized the lesion in 15/17 patients. In 2 patients with negative CTs, gallium DOTATATE positron emission tomography (PET) scans localized the lesion. Despite difficulties localizing bronchial carcinoids, the cure rate was high (72%). In contrast, thymic carcinoids were easily localized but had poor outcomes.ConclusionEAS cannot be ruled out on the basis of marginally elevated ACTH. In cases with an equivocal MRI pituitary finding, prior IPSS can help avoid unnecessary TSS. CT is a useful modality for localization of an ectopic source. Functional imaging may help in cases where anatomical imaging fails. (Endocr Pract. 2013;19:1007-1014)     

Clinical Profile of Ectopic Thyroid in Asian Indians: a Single-Center Experience

ObjectiveTo assess clinical characteristics of patients with ectopic thyroid seen at a single tertiary care center in India.MethodsIn this case series, we retrospectively reviewed the data of patients who presented with ectopic thyroid between January 1995 and March 2008. Clinical presentation, nuclear imaging findings, endocrine profile, and clinical management were analyzed.ResultsRecords of 22 female patients and 14 male patients were reviewed. Ectopic thyroid was more common in female patients. Mean age of presentation was 14.3 years (median, 14 years; range, 5 months to 40 years). Seventeen patients (47%) presented with lingual thyroid, detected incidentally or because of dysphagia and bleeding while eating, and 19 patients (53%) had sublingual thyroid, which mainly presented as an anterior neck swelling. Thirty patients (83%) had hypothyroidism (overt or subclinical). In 29 patients (81%), ectopic thyroid either in the neck or in the lingual area was the only functional thyroid tissue. Thirty-one patients (86%) were treated medically, and surgery was performed in only 5 patients (14%) who had either recurrent bleeding or dysphagia.ConclusionsEctopic thyroid should be considered during the evaluation of a midline neck mass or hypothyroidism. Careful clinical examination, thyroid function tests, and radionuclide imaging help establish the diagnosis and localize ectopic thyroid. Appropriate treatment should be decided on an individual basis. (Endocr Pract. 2009;15:322-325)     

Cytomegalovirus Disease in Renal Transplant Recipients: A Single-Center Experience

Cytomegalovirus (CMV) is the most common viral infection following kidney transplant, has been recognized as a major factor for graft loss and increased incidence of acute rejection. Different studies have reported a variable incidence of CMV disease with the use of Mycophenolate mofetil (MMF). We retrospectively analyzed our renal transplant recipients to review the results of CMV disease and to compare CMV disease in patient on Azathioprine and MMF for this purpose we retrospectively reviewed 521 live related kidney transplant recipients at our institute. 74 (14.2 %) live related allograft recipients developed CMV disease after a median interval of 7.18 ± 4.35 months from transplantation. The mean age was 36.15 ± 10.7 years. 63 of the patients were male. Malaise, fever and diarrhea were among most common symptoms. 20 (27.02 %) of the 74 recipients developed transaminitis, 13 (17.2 %) developed CMV gastritis, 5 (9.13 %) recipients developed pneumonia, and 3 (4.05 %) patient developed colitis. 59 (80 %) patients had leucopenia and 41 (56.5 %) developed thrombocytopenia. Mean serum creatinine level was 1.5 ± 0.4 (0.9–2.4) mg/dl before the disease, 1.9 ± 0.6 (1.3–3.6) mg/dl at the time of the diagnosis, and 1.7 ± 0.06 (0.8–4.2) mg/dl at the end of the treatment. CMV disease developed in 9 (36 %) of recipients who received basiliximab as induction therapy and 13 (30.24 %) of recipients who received ATG (p > 0.05). The incidence of CMV disease was similar in cyclosporine based regimen (13.2 %) and Tacrolimus based regimen 27 (16.16 %) (p = 0.137) and was also similar in Azathioprine 41 (9.5 %) and MMF group 33 (14.3 %) (p = 0.163). There was no significant difference in severity of CMV disease in both groups, except a higher incidence of leucopenia in Azathioprine group (86 vs. 74 %, p < 0.05) as compared to MMF group. 51 (68.91 %) patient developed graft dysfunction during CMV disease. In conclusion we report a low incidence (14.2 %) and milder form of cytomegalovirus disease at our center. Use of universal cytomegalovirus prophylaxis was associated with a low incidence and milder form of the disease. Incidence of CMV disease was similar between Azathioprine and MMF groups.     

Ovotesticular Disorder of Sex Development: A Single-Center Experience

Objective: Ovotesticular disorder of sex development (OT DSD) is a rare disorder of sex development characterized by the presence in the same individual of both histologically proven testis and ovary. There are scant data from the Indian subcontinent regarding this disorder. The aim of this study was to describe the clinical, biochemical, imaging, cytogenetic, surgical, and histopathologic findings and outcomes of patients with OT DSD from Western India.Methods: The records of patients referred to our center for disorders of sex development between 2005 and 2013 were reviewed, and 7 patients were found to have histologically proven OT DSD.Results: The median age at presentation was 8 years (range, 2 months to 25 years). Clinical presentation varied from genital ambiguity and inguinal swelling at birth to gynecomastia and cyclical hematuria after puberty. Karyotype was 46, XX in 6 patients and 46, XY in 1 patient. All patients underwent pelvic ultrasonography, laparoscopy, and surgery for removal of gonads not congruous with the chosen sex of rearing. Gender assignment for all the patients was done by the parents at birth, which was mainly influenced by the external genitalia and sociocultural influences, with 5 out of the 7 patients being reared as males. There was no evidence of gonadal tumors in our study.Conclusion: OT DSD should be considered as one of the differential diagnoses in cases of ambiguous genitalia with nonpalpable or asymmetrical gonads, pubertal gynecomastia, and cyclical hematuria, irrespective of the karyotype or internal genitalia.Abbreviations: hCG = human chorionic gonadotropin MGD = mixed gonadal dysgenesis OT DSD = ovotesticular disorder of sex development     

Post-Operative Complications in Living Liver Donors: A Single-Center Experience in China

The gap between the growing demand for available organs and the cadaveric organs facilitates the adoption of living donor liver transplantation. We retrospectively identified and evaluated the post-operative complications as per the modified Clavien classification system in 152 living liver donors at at the First Affiliated Hospital, College of Medicine, Zhejiang University between December, 2006 and June, 2014. Post-operative complications were observed in 61 patients (40.1%) in the present study, but no mortality was reported. Complications developed in 58 (40.0%) right, 1 (33.3%) left, and 2 (66.7%) lateral left hepatectomy donors. The prevalence of re-operation was 1.3%. Grade I and II complications were observed in 38 (25.0%) and 11 (7.2%) donors, respectively. Grade IIIa complications developed in 9 (5.9%) donors and only 3 (2.0%) patients reported grade IIIb complications. The most common complication was pleural effusion that occurred in 31 (20.4%) donors. No significant prognostic baseline factor was identified in this study. In conclusion, living donors experienced various complications, which were usually mild and had a good prognosis.     

Mycetoma: a clinical dilemma in resource limited settings

Background

Mycetoma is a chronic mutilating disease of the skin and the underlying tissues caused by fungi or bacteria. Although recently included in the list of neglected tropical diseases by the World Health Organization, strategic control and preventive measures are yet to be outlined. Thus, it continues to pose huge public health threat in many tropical and sub-tropical countries. If not detected and managed early, it results into gruesome deformity of the limbs. Its low report and lack of familiarity may predispose patients to misdiagnosis and delayed treatment initiation. More so in situation where diagnostic tools are limited or unavailable, little or no option is left but to clinically diagnose these patients. Therefore, an overview of clinical course of mycetoma, a suggested diagnostic algorithm and proposed use of materials that cover the exposed susceptible parts of the body during labour may assist in the prevention and improvement of its management. Furthermore, early reporting which should be encouraged through formal and informal education and sensitization is strongly suggested.

Main text

An overview of the clinical presentation of mycetoma in the early and late phases, clues to distinguish eumycetoma from actinomycetoma in the field and the laboratory, differential diagnosis and a suggested diagnostic algorithm that may be useful in making diagnosis amidst the differential diagnosis of mycetoma is given. Additionally, a proposed preventive measures which may be helpful in the community is also provided. Since treatment is currently based on expert opinion, we encourage active research to establish treatment guideline for it.

Conclusion

Since delay in visiting health facility results into gruesome complication, early presentation, recognition and initiation of appropriate choice of regimen is helpful in reducing complications. The clinical overview of mycetoma and the suggested algorithm may enhance suspicion and possibly increase recognition of mycetoma in the community and further guide in differentiation of eumycetoma from actinomycetoma. There is an urgent need for research funding for mycetoma, a disease plagued by severe physical disabilities and social stigma leading to isolation.

     

Candida Endocarditis in Patients with Candidemia: A Single-Center Experience of 14 Cases

Mycopathologia - A retrospective, single-center analysis of 14 cases of Candida endocarditis (from 355 candidemia cases during the years 2012–2019) revealed a high in-hospital mortality...     

Coccidioidomycosis: An Update

Coccidioidomycosis is the oldest of the major mycoses. In recent years the incidence of the disease has increased in California and Arizona, which may be partially due to the massive migration to the endemic region. The endemic region for the disease lays exclusively in the Western Hemisphere, between the 40° latitudes north and south. The disease manifests in one of four clinical syndromes: acute pulmonary, chronic pulmonary and acute or chronic disseminated coccidioidomycosis. Serologic tests identifying anticoccidioidal antibodies are the most frequently employed assays for diagnosis. Primary coccidioidomycosis is usually self-limited; therapy of primary disease is recommended when symptoms persist for more than 6 weeks, for severe acute cases and for patients with impaired cellular immunity. Chronic pulmonary coccidioidomycosis and all forms of disseminated coccidioidomycosis require antifungal therapy. The drugs of choice are either fluconazole or itraconazole.     

Sex Determination in Reptiles: An Update

Sex determination and sex differentiation are two separate butrelated phenomena. Sex differentiation is a programmed cascadeof events in which the indifferent gonad develops as a testisor an ovary with the appropriate urogenital and secondary sexcharacters. Sex determination is the event that sets this cascadein motion. In placental mammals, there is good evidence thatsex is determined by a gene on the Y chromosome (SRY) that initiatestestis formation. In the absence of SRY an ovary develops. Thereare, however, examples of placental mammal that develop as normalmales with no detectable SRY. In reptiles, sex differentiationappears to be similar to mammals (i.e., the same genes and hormonesact ina similar manner), but sex determination is clearly verydifferent. Ovarian differentiation in placental mammals canoccur in the absence of estrogen or an estrogen receptor. Ovariandifferentiation in reptiles requires the presence of estrogen.In the absence of estrogen a testis develops. In TSD reptiles,embryos will develop as females when treated with estrogen evenif eggs are incubated at male-inducing temperatures, and conversely,will develop as males when estrogen synthesis is blocked ineggs incubated at female-inducing temperatures. A number ofother genes have also been shown to be important in mammaliansex determination. One of these genes, Sox9, which is expressedin differentiating mouse testis, has recently been found tobe expressed in embryonic reptile testis. Other genes that appearto be common to both mammals and reptiles in the sex determiningcascade are SF- 1, MIH, and possibly DAX-1. Current researchis now focused on how the gene that produces the enzyme necessaryfor estrogen synthesis (aromatase) is regulated in the embryosof reptiles with genetic or environmental sex determination.Controversial issues in reptilian sex determination are 1) therole of the brain in gonadal sex determination, and 2) the roleof steroid hormones in the yolk prior to sex determination     

Bioremoval of Cyanide and Phenol from Industrial Wastewater: An Update

In nature, phenols and cyanides are produced by certain microbes and plants. Phenols are antioxidants found in almost all plants, and cyanides are important components of lima beans, almonds, and cassava. Their presence in small amounts may not upset the environment, but their large-scale production, wide applicability, and unrestricted release by the industries makes them widespread and important pollutants. Phenols and cyanides can be recovered/removed from wastewater streams using various physicochemical techniques practiced commercially. Lack of complete mineralization, cost-effectiveness, and release of secondary by-products are amongst a few of the major considerations that limit the installation of such processes. Biological removal of such pollutants from industrial waste has gained momentum in recent years, as they promise to surpass the major drawbacks laid by the physicochemical methods and can be practically carried out in all conditions. Presence of either cyanide or phenol is highly dangerous, and in the presence of both, the effect is compounded. The present review illustrates the various industries involved in the release of phenols, cyanides, or both; it summarizes the available technologies for their treatment and emphasizes recent advances and advantages of biological abatement of these pollutants.     

Inhibitory Glycine Receptors: An Update

Strychnine-sensitive glycine receptors (GlyRs) mediate synaptic inhibition in the spinal cord, brainstem, and other regions of the mammalian central nervous system. In this minireview, we summarize our current view of the structure, ligand-binding sites, and chloride channel of these receptors and discuss recently emerging functions of distinct GlyR isoforms. GlyRs not only regulate the excitability of motor and afferent sensory neurons, including pain fibers, but also are involved in the processing of visual and auditory signals. Hence, GlyRs constitute promising targets for the development of therapeutically useful compounds.