11beta-Hydroxysteroid dehydrogenase Type 1: genetic polymorphisms are associated with Type 2 diabetes in Pima Indians independently of obesity and expression in adipocyte and muscle

AIMS/HYPOTHESIS

The enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) modulates tissue-specific glucocorticoid concentrations by generating active cortisol. We have shown that adipose tissue 11beta-HSD1 mRNA levels were associated with adiposity and insulinaemia. Here we conducted further expression and genetic association studies in Pima Indians.

METHODS

The 11beta-HSD1 mRNA concentrations were measured in abdominal subcutaneous adipocytes (n=61) and skeletal muscle tissues (n=64). Single nucleotide polymorphisms in the HSD11B1 gene were genotyped in a larger group of full-blooded Pima Indians.

RESULTS

Two representative SNPs (SNP1, n=706; SNP5, n=839) were associated with Type 2 diabetes mellitus (p=0.01), although neither SNP was associated with obesity. Among subjects with normal glucose tolerance, SNP1 (n=127) and SNP5 (n=159) were associated with insulin-mediated glucose uptake rates (p=0.03 and p=0.04), and SNP1 was further associated with fasting, 30-min, and 2-h plasma insulin concentrations (p=0.002, p=0.002 and p=0.03). Adipocyte 11beta-HSD1 mRNA concentrations were correlated positively with adiposity and insulinaemia, and were additionally negatively correlated with insulin-mediated glucose uptake rates; nevertheless, the adipocyte 11beta-HSD1 expression did not correlate with genotypes of the donors. The muscle 11beta-HSD1 mRNA concentrations did not correlate with any anthropometric or metabolic variables.

CONCLUSIONS/INTERPRETATION

We confirmed that adipocyte 11beta-HSD1 mRNA concentrations were associated with adiposity, and showed that genetic variations in the HSD11B1 gene were associated with Type 2 diabetes mellitus, plasma insulin concentrations and insulin action, independent of obesity. The variable adipose expression might not be a primary consequence of these HSD11B1 SNPs. Therefore, it is possible that the HSD11B1 gene is under tissue-specific regulation, and has tissue-specific consequences.

Platelet function tests using platelet aggregometry: need for repetition of the test for diagnosis of defective platelet function

Four hundred and ninety seven patients were referred to our center for platelet aggregation studies because of spontaneous mucocutaneous bleeds. All these patients had normal complete blood count, platelet count and peripheral smears except in ten patients of Bernard Soulier Syndrome where platelet count was marginally reduced in the presence of giant platelets. Two hundred and eighty patients were found to have normal platelet aggregation to ADP, collagen, ristocetin and arachidonic acid. Out of the remaining 217 patients, 62 patients were diagnosed to have Glanzmanns thrombasthenia, 10 Bernard Soulier Syndrome, 6 storage pool deficiencies, 7 cyclooxygenase deficiencies and 72 von Willebrand disease. In all the patients with GT and BSS, diagnosis was confirmed with flow cytometry using multiple monoclonal antibodies to GPIIb-IIIa and GPIb-IX. There were sixty patients where initial platelet aggregation studies showed reduced (<30%) aggregation to either ADP, collagen, ristocetin or arachidonic acid in its various combination, however in 12 such patients (20%) the platelet aggregation studies were normal on repetition. All our platelet aggregation studies were done only after assuring that the patient is not taking any medicine for at least 7-10 days which may affect the platelet function tests. The present study shows that single atypically abnormal platelet aggregation studies should always be repeated. Finally in 48/217 patients (22%) some aggregation abnormality to one or more of the agonists persisted, although we could not categorize these patients into any clear-cut platelet disorder. None of these 48 patients platelet associated immunoglobulin was increased by flow cytometry. It is possible that large number of patients from that disorder will finally prove to be some form of platelet secretory defect. In north India similar group of defect in a large number of patients have been reported as isolated PF3 abnormality or thrombasthenic thrombopathy.

Hodgkin's lymphoma: immunohistochemical features and its association with EBV LMP-1. Experience from a South Indian hospital

AIMS

Immunohistochemistry (IHC) is known to aid in the diagnosis of Hodgkin's lymphoma (HL). We studied HL using an antibody panel for Reed-Sternberg cells (RSCs) to find which antibody would be most useful for identification of RSCs. We also studied the association of Epstein-Barr virus (EBV) latent membrane protein-1 (LMP-1) with HL in South India.

METHODS

Lymph node biopsies of 100 cases of untreated HL were included in this study. Antibodies against CD15, CD30, CD3, CD20 (L26), CD45 (LCA), EMA and EBV LMP-1 were used for paraffin section IHC.

RESULTS

Of the 100 cases of HL, the RSCs stained with CD30 (93%), CD15 (67%), CD20 (17%) and CD3 (2%). EBV LMP-1 was positive in 82 (82%) cases, most often in the nodular sclerosis subtype, 43 (86%) cases.

CONCLUSIONS

(1) Of the panel of antibodies, CD30 was the most useful in identifying RSCs in classical HL. (2) EBV LMP-1 was demonstrated in 82% of all cases of HL and in 96% of childhood cases.

Tunicate cytokine-like molecules and their involvement in host defense responses

Tunicates (ascidians or sea squirts) are a large group of invertebrate chordates that are closely related to vertebrates. Their critical phylogenetic position has stimulated substantial interest in their host defense ("immune") responses. Whilst this interest has generated a wealth of knowledge regarding the humoral and cellular mechanisms that undertake defensive responses, there is less known about the regulation of those reactions. This chapter focuses on three cellular responses (cell proliferation, phagocytosis and chemotaxis) that are known to be regulated by cytophilic humoral molecules. Some of the humoral factors that affect these responses have functional and physicochemical similarities to vertebrate cytokines, like interleukin-1. However, the only regulatory molecules that have been characterized at a molecular level bear far greater similarity to C-type lectins or complement components.

Near-field optical mapping of exciton wave functions in a GaAs quantum dot

Near-field photoluminescence imaging spectroscopy of naturally occurring GaAs quantum dots (QDs) is presented. We successfully mapped out center-of -mass wave functions of an exciton confined in a GaAs QD in real space due to the enhancement of spatial resolution up to 30 nm. As a consequence, we discovered that the spatial profile of the exciton emission, which reflects the shape of a monolayer-high island, differs from that of biexciton emission, due to different distributions of the polarization field for the exciton and biexciton recombinations. This novel technique can be extensively applied to wave function engineering in the design and the fabrication of quantum devices.

Contemporary management of fibroids

INTRODUCTION

More women are delaying child-bearing such that gynaecologists can no longer resort as frequently to definitive treatments, such as a hysterectomy, in the management of uterine fibroids. A review of newer conservative medical, radiological and surgical therapies and minimal access approaches to the organ-preserving myomectomy operation are discussed.

MATERIALS AND METHODS

Data from published literature describing newer modalities of treatment and reviewing updated information of the impact of fibroids and myomectomy on fertility potential were collated.

RESULTS

Medical treatments serve to retard the growth of fibroids temporarily and have short-term success in the amelioration of symptoms. Uterine artery embolisation is a novel non-surgical approach to debulking of uterine fibroids and the relieve of symptoms. Hysterectomy is a treatment choice that is curative. Laparoscopic hysterectomy carries a 3% risk of major complications compared to 1% via a laparotomy. Laparoscopic myomectomy is a viable alternative to open myomectomy but due diligence must be exercised in ensuring meticulous and secure myomectomy defect repair. The risk of uterine dehiscence has been reported to be about 0.5% which is comparable to that in traditional open myomectomy which has been somewhat understated. Hysteroscopic resection of submucous fibroids is very efficacious and preserves reproductive potential. This procedure and myomectomy of intramural fibroids associated with intracavitary distortion are clearly indicated as these types of fibroids have been implicated as a cause of infertility and pregnancy loss at least 2 to 3 times higher than controls. This relationship prevailed in patients undergoing assisted reproduction.

CONCLUSION

The management of uterine fibroids has undergone a revolution in the past few decades with better understanding of its impact on fertility and technical advances in endoscopy and radiologic embolisation techniques and also pharmaceutical alternatives such as gonadotrophin-releasing hormone agonist and progesterone intrauterine contraceptive devices. Advances in molecular biology may provide an opportunity to manipulate receptors and cellular biology in order to arrest tumourigenesis altogether.

Acute stress increases calcium current amplitude in rat hippocampus: temporal changes in physiology and gene expression

Activation of hippocampal glucocorticoid receptors in vitro increases calcium current amplitude through a process requiring DNA binding of receptor homodimers. We here investigated (i). whether similar increased calcium currents also occur following in vivo glucocorticoid receptor activation due to stress and (ii). if so, whether this can be explained by increased expression of calcium channel subunits. Rats were exposed to a novelty stress; some of the animals were pretreated with a glucocorticoid receptor antagonist. In subsequently prepared hippocampal slices, calcium currents were recorded from identified CA1 pyramidal neurons, after which RNA was collected, linearly amplified and hybridized with cDNA clones. Glucocorticoid receptor activation due to novelty exposure was associated with large total peak calcium currents and high-threshold noninactivating currents. Low-threshold calcium currents were not affected. Large total peak and noninactivating current amplitudes were also seen when animals received a more severe stressor, i.e. additional ether exposure. In the stressed groups, the total peak and high-threshold calcium current gradually increased with time resulting in a significant enhancement at >or=3 h after stress exposure. In the same cells, the summated (relative) RNA expression of various alpha1 calcium channel subunits was only transiently enhanced, prior to the functional changes. These data indicate that in vivo activation of glucocorticoid receptors due to stress gradually increases specific calcium current components. Prior to the functional change, increased expression of calcium channel subunits was observed, suggesting that the enhanced function could be explained by transcriptional regulation of the channels.

One hundred and three concurrent IVF successes for donors and recipients who shared eggs: ethical and practical benefits of egg sharing to society

Egg sharing is a form of egg donation where complete strangers can collaborate anonymously to overcome their involuntary childlessness. In a retrospective analysis, results of egg sharing treatments were analysed in 37 consecutive donors and 39 recipients who had achieved concurrent success following IVF treatment. The interval between being accepted onto the programme and receiving treatment was less than 6 months for most patients. Births of 103 infants are expected. Multiple pregnancy rates were high and equivalent in both the groups (donors 32.4%, recipients 25.6%) despite the original number of eggs available being halved at egg collection and equal numbers being allocated to donors and recipients. On average fewer than six eggs were required for the birth of each baby. More successes are expected in time as 33 couples (43.4%) have their excess embryos stored for future use. The programme avoided the need to advertise for donors. This had particular significance for members of minority ethnic groups. It is surmised that promotion of concurrent treatment of egg sharers and recipients will attract funds from insurance providers or health boards who are unimpressed by IVF treatments with indifferent success rates and runaway costs. In the event of such funds materializing, meagre NHS resources for IVF treatment could be better focused. Overall, the benefit derived from applying the simultaneous treatment of anonymous donors and recipients is so compelling as to make it the preferred IVF option for qualifying couples.

The modified endoscopic Lothrop procedure in the treatment of complicated chronic frontal sinusitis

The purpose of this study was to evaluate the modified endoscopic Lothrop procedure in the management of complicated frontal sinus disease which has breached the confines of the sinus walls and extended into the cranial cavity or orbit. Fourteen patients with radiological evidence of 17 complications of frontal sinus disease presented over a 23-month period. CT scan and MRI scans revealed the presence of posterior table erosion and extension of the frontal sinus disease into the anterior cranial fossa in 10 patients. In addition, seven patients had intraorbital complications, with three patients having both intracranial and orbital complications. All patients underwent a modified endoscopic Lothrop procedure as part of the management of the complication. In addition, one patient required an orbital abscess drainage and repair of an encephalocele, with a second patient requiring drainage of an orbital subperiosteal abscess. At follow-up, all patients were asymptomatic and had patent frontal sinus ostia. Follow-up ranged from 8 months to 38 months with a median of 25 months. Three patients required a revision of their frontal ostium. Two patients had allergic fungal sinusitis with aggressive polyp recurrence and ostial re-stenosis while one patient developed recurrent orbital infections from a retained frontal sinus cell. Currently, all have patent ostia, with an average size of 14.6 x 11 mm. The modified endoscopic Lothrop procedure is an effective form of treatment in the management of complicated frontal sinus disease. The results are comparable to those achieved with other surgical approaches such as the osteoplastic flap with obliteration.

Liponeurocytoma of the cerebellum--a case report

We report the characteristic neuropathological features of a rare case of cerebellar liponeurocytoma in a 62-year-old female. The tumor has a low proliferative potential and carries a favorable prognosis.

Cerebellar hemisphere, an uncommon location for pleomorphic xanthoastrocytoma and lipidized glioblastoma multiformis

Lipidized glioblastoma multiformis (LGB) and pleomorphic xanthoastrocytoma (PXA) are often supratentorial in location and occur in the second to fourth decade. This report presents two young patients, one having LGB and the other having PXA in the cerebellum. Histological differentiation between LGB and PXA is discussed.

Rhabdoid tumor of the thalamus

Rhabdoid tumors of the central nervous system are uncommon tumors. About 188 cases have been reported in the literature so far. In this report, we describe a case of a rhabdoid tumor of the thalamus in a 35-year-old male patient. Light microscopic and immunohistochemical features are discussed and the relevant literature reviewed.

Should non-patient volunteers donate eggs?

Egg donation is associated with medical and surgical risks regardless of the source of eggs, be it through commercial, altruistic or more recent egg-share donors. Egg sharing is the only system that does not turn a healthy woman (the donor) into a patient. Using carefully selected egg-share donors, pregnancy rates for both donor and recipient are as good as any egg-donation programme, with one cohort of eggs being used with more efficiency. We propose that anonymous egg sharing, as licensed by the Human Fertilisation and Embryology Authority (HFEA), minimizes risk, is ethically sound and should be considered as the only acceptable form of anonymous egg donation.

False aneurysm of cavernous carotid artery and carotid cavernous fistula: complications following transsphenoidal surgery

We present two cases of carotid injury during transsphenoidal surgery for pituitary adenoma. While in one of the cases it resulted in the formation of a false aneurysm of cavernous carotid artery, in the other patient, a carotid cavernous fistula (CCF) formed. The false aneurysm was managed by surgical trapping and the patient had an uneventful recovery. The CCF was initially managed with balloon embolization. The balloon got deflated and resulted in a false aneurysm with persistent CCF. This was occluded with Guglielmi Detachable Coils (GDC). The management options are discussed and relevant literature is reviewed. We emphasize the importance of an early cerebral angiography to know the status of the injured carotid artery and formation of false aneurysm / fistula.

Intracranial aneurysmal bone cyst manifesting as a cerebellar mass

A 17-year-old boy presented with symptoms of raised intracranial pressure for a month. Investigations revealed a large extra-cerebellar mass. The lesion was radically resected. It arose from the petrous bone. Histology revealed that the lesion was an aneurysmal bone cyst [ABC].

Bacterial growth efficiency in the tropical estuarine and coastal waters of Goa, southwest coast of India

Bacterial growth efficiency (BGE) is an index of organic carbon passing through bacteria in an aquatic system. BGE values of natural bacterioplankton assemblages were measured in tropical estuarine and adjacent coastal waters in Goa along the southwest coast of India. The BGE values for estuarine and coastal waters were 18 (+/-7.84%) and 11 (+/-4.19%), respectively. BGE in these waters were at the lower end of what is usually found in productive systems. This may be due to the high respiration rates. Further, it was observed that grazers also influenced BGE. As BGE was positively correlated with bacterial productivity, the observed variation in BGE was attributed to bacterial productivity. BGE was inversely related to C:N ratio, indicating a close coupling between the nature of the substrates and BGE. Being system-dependent, the variations in BGE at the two locations were dynamic and were regulated by the quality of the substrates. Therefore, a constant value for BGE would lead to error in carbon budgets in these waters.

Validation of biokinetic models of Cs and I using their daily dietary intakes and organ contents in an adult Indian population

The daily dietary intakes and total contents of Cs and I in skeletal muscle and thyroid, respectively, for an average Indian adult were estimated by determining their concentrations in the total cooked diet and tissue samples using instrumental neutron activation analysis. These data were then used to predict the biological half-lives of Cs and I and their radioactive counterparts for the Reference Indian Man. The predicted biological half-lives of Cs and I for Reference Indian Man were found to be comparable with the reported values for the ICRP Reference Man.

Minimizing risk in anonymous egg donation

Assisted conception carries with it known and putative medical and surgical risks. Exposing healthy women to these risks in order to harvest eggs for donation when a safer alternative exists is morally and ethically unacceptable. Egg sharing minimizes risk and provides a source of eggs for donation. Anonymity protects all parties involved and should not be removed.

Identification and mapping of an AFLP marker linked to Gm7, a gall midge resistance gene and its conversion to a SCAR marker for its utility in marker aided selection in rice

We have identified an AFLP marker SA598 that is linked to Gm7, a gene conferring resistance to biotypes 1, 2 and 4 of the gall midge ( Orseolia oryzae), a major dipteran pest of rice. A set of PCR primers specific to an RFLP marker, previously identified to be linked to another gall midge resistance gene Gm2, also amplified a 1.5-kb (F8LB) fragment that is linked to Gm7. Gm7 is a dominant gene and non-allelic to Gm2. Hybridization experiments with clones from a YAC library of Nipponbare, a japonica variety, a BAC library of IR-BB21, an indica variety, and cosmid clones encompassing Gm2 from Phalguna, an indica variety, with F8LB and SA598 as probes, revealed that Gm7 is tightly linked to Gm2 and is located on chromosome 4 of rice. SA598 was sequenced and the sequence information was used to design sequence-characterized amplified region (SCAR) primers. The potential use of these SCAR primers in marker-aided selection of Gm7 in a rice breeding program has been demonstrated.