Molecular basis of RanGTP-activated release of Histones H2A-H2B from Importin-9

Imp9 is the primary importin for shuttling H2A-H2B from the cytoplasm to the nucleus. It employs an unusual mechanism where the binding of RanGTP is insufficient to release H2A-H2B. The resulting stable RanGTP·Imp9·H2A-H2B complex gains nucleosome assembly activity with H2A-H2B able to be deposited into an assembling nucleosome in vitro. Using hydrogen-deuterium exchange coupled with mass spectrometry (HDX), we show that Imp9 stabilizes H2A-H2B beyond the direct-binding site, like other histone chaperones. HDX also shows that binding of RanGTP releases H2A-H2B contacts at Imp9 HEAT repeats 4-5, but not 18-19. DNA- and histone-binding surfaces of H2A-H2B are exposed in the ternary complex, facilitating nucleosome assembly. We also reveal that RanGTP has a weaker affinity for Imp9 when H2A-H2B is bound. Imp9 thus provides a connection between the nuclear import of H2A-H2B and its deposition into chromatin.

Molecular basis of RanGTP-activated nucleosome assembly with Histones H2A-H2B bound to Importin-9

Padavannil et al. 2019 show that Importin-9 (Imp9) transports Histones H2A-H2B from the cytoplasm to the nucleus using a non-canonical mechanism whereby binding of a GTP-bound Ran GTPase (RanGTP) fails to evict the H2A-H2B cargo. Instead, a stable complex forms, comprised of equimolar RanGTP, Imp9, and H2A-H2B. Unlike the binary Imp9•H2A-H2B complex, this RanGTP•Imp9•H2A-H2B ternary complex can release H2A-H2B to an assembling nucleosome. Here, we define the molecular basis for this RanGTP-activated nucleosome assembly by Imp9. We use hydrogen-deuterium exchange coupled with mass spectrometry and compare the dynamics and interfaces of the RanGTP•Imp9•H2A-H2B ternary complex to those in the Imp9•H2A-H2B or Imp9•RanGTP binary complexes. Our data are consistent with the Imp9•H2A-H2B structure by Padavannil et al. 2019 showing that Imp9 HEAT repeats 4-5 and 18-19 contact H2A-H2B, as well as many homologous importin•RanGTP structures showing that importin HEAT repeats 1 and 3, and the h8 loop, contact RanGTP. We show that Imp9 stabilizes H2A-H2B beyond the direct binding site, similar to other histone chaperones. Importantly, we reveal that binding of RanGTP releases H2A-H2B interaction at Imp9 HEAT repeats 4-5, but not 18-19. This exposes DNA- and histone-binding surfaces of H2A-H2B, thereby facilitating nucleosome assembly. We also reveal that RanGTP has a weaker affinity for Imp9 when H2A-H2B is bound. This may ensure that H2A-H2B is only released in high RanGTP concentrations near chromatin. We delineate the molecular link between the nuclear import of H2A-H2B and its deposition into chromatin by Imp9.

Significance

Imp9 is the primary importin for shuttling H2A-H2B from the cytoplasm to the nucleus. It employs an unusual mechanism where the binding of RanGTP alone is insufficient to release H2A-H2B. The resulting stable RanGTP•Imp9•H2A-H2B complex gains nucleosome assembly activity as H2A-H2B can be deposited onto an assembling nucleosome. We show that H2A-H2B is allosterically stabilized via interactions with both N- and C-terminal portions of Imp9, reinforcing its chaperone-like behavior. RanGTP binding causes H2A-H2B release from the N-terminal portion of Imp9 only. The newly-exposed H2A-H2B surfaces can interact with DNA or H3-H4 in nucleosome assembly. Imp9 thus plays a multi-faceted role in histone import, storage, and deposition regulated by RanGTP, controlling histone supply in the nucleus and to chromatin.

Promoter hypomethylation as potential confounder of Ras gene overexpression and their clinical significance in subsets of urothelial carcinoma of bladder

Overexpression of normal Ras and its aberrant CpG island methylation in the promoter regions have been shown to direct cells for uncontrolled abnormal growth and bladder tumor formation and therefore, fetched recent attention as a marker of diagnosis and prognosis to predict the biological behavior of urothelial carcinoma of bladder (UCB). Methylation pattern at CpG islands of the promoter regions of rat sarcoma (Ras) gene homologues namely Kristen-Ras (K-Ras), Harvey (H-Ras), and Neuroblastoma (N-Ras) were examined by methylation specific polymerase chain reaction (MSP). Real time-quantitative polymerase chain reaction (RT-qPCR) was done to determine transcriptomic expressions of these Ras isoforms in the prospective series of 42 NMIBC (non-muscle invasive bladder cancer) and 45 MIBC (muscle invasive bladder cancer) biopsies. CpG loci in H-Ras and K-Ras were observed to be more hypomethylated in MIBC, whereas more hypomethylation in N-Ras was noted in NMIBC. Strong association of hypomethylation index with tumor stage, grade, type and size validate them it as marker of diagnosis in UCB patients. Differential overexpression of H-Ras, N-Ras and K-Ras genes in NMIBC and MIBC and their association with patients' demographics identify them as important diagnostic markers in pathogenesis of UCB. Given the reported ability of promoter hypomethylation to activate Ras expression, correlation studies examined positive significant association between hypomethylation index and expression. Study concludes that promoter hypomethylation of N-Ras and K-Ras could be a potential confounder of their increased expression in NMIBC. Biological significance of simultaneous presence of higher expression and promoter hypomethylation of Ras gene isoforms in MIBC is difficult to resolve in a given cohort of patients.

Mutational analysis of Ras hotspots in patients with urothelial carcinoma of the bladder

BACKGROUND

Mutational activation of Ras genes is established as a prognostic factor for the genesis of a constitutively active RAS-mitogen activated protein kinase pathway that leads to cancer. Heterogeneity among the distribution of the most frequent mutations in Ras isoforms is reported in different patient populations with urothelial carcinoma of the bladder (UCB).

AIM

To determine the presence/absence of mutations in Ras isoforms in patients with UCB in order to predict disease outcome.

METHODS

This study was performed to determine the mutational spectrum at the hotspot regions of H-Ras, K-Ras and N-Ras genes by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) and DNA sequencing followed by their clinical impact (if any) by examining the relationship of mutational spectrum with clinical histopathological variables in 87 UCB patients.

RESULTS

None of the 87 UCB patients showed point mutations in codon 12 of H-Ras gene; codon 61 of N-Ras gene and codons 12, 13 of K-Ras gene by PCR-RFLP. Direct DNA sequencing of tumor and normal control bladder mucosal specimens followed by Blastn alignment with the reference wild-type sequences failed to identify even one nucleotide difference in the coding exons 1 and 2 of H-Ras, N-Ras and K-Ras genes in the tumor and control bladder mucosal specimens.

CONCLUSION

Our findings on the lack of mutations in H-Ras, K-Ras and N-Ras genes could be explained on the basis of different etiological mechanisms involved in tumor development/progression, inherent genetic susceptibility, tissue specificity or alternative Ras dysfunction such as gene amplification and/or overexpression in a given cohort of patients.

Mechanistic regulation of epithelial-to-mesenchymal transition through RAS signaling pathway and therapeutic implications in human cancer

RAS effector signaling instead of being simple, unidirectional and linear cascade, is actually recognized as highly complex and dynamic signaling network. RAF-MEK-ERK cascade, being at the center of complex signaling network, links to multiple scaffold proteins through feed forward and feedback mechanisms and dynamically regulate tumor initiation and progression. Three isoforms of Ras harbor mutations in a cell and tissue specific manner. Besides mutations, their epigenetic silencing also attributes them to exhibit oncogenic activities. Recent evidences support the functions of RAS oncoproteins in the acquisition of tumor cells with Epithelial-to-mesenchymal transition (EMT) features/ epithelial plasticity, enhanced metastatic potential and poor patient survival. Google Scholar electronic databases and PubMed were searched for original papers and reviews available till date to collect information on stimulation of EMT core inducers in a Ras driven cancer and their regulation in metastatic spread. Improved understanding of the mechanistic basis of regulatory interactions of microRNAs (miRs) and EMT by reprogramming the expression of targets in Ras activated cancer, may help in designing effective anticancer therapies. Apparent lack of adverse events associated with the delivery of miRs and tissue response make 'drug target miRNA' an ideal therapeutic tool to achieve progression free clinical response.

Quantifying Bound and Active Antibodies Conjugated to Gold Nanoparticles: A Comprehensive and Robust Approach To Evaluate Immobilization Chemistry

Gold nanoparticles (AuNPs) functionalized with antibodies have the potential to improve biosensing technology because of the unique optical properties of AuNPs and the specificity of antibody-antigen interactions. Critical to the development and optimization of these AuNP-enabled sensing technologies is the immobilization of the antibody onto the AuNP. The development of novel immobilization strategies that optimize antibody loading and orientation in an effort to enhance antibody activity, and therefore assay performance, has been the focus of many recent studies. However, few analytical methods exist to accurately quantify the activity of conjugated antibodies and reliably compare different immobilization strategies. Herein, we describe an enzyme-mediated assay to quantify the fraction of the immobilized antibodies that is accessible for antigen binding. Anti-horseradish peroxidase (anti-HRP) antibody is mixed with AuNPs to allow for conjugation, and the unbound, excess antibody is quantified with a modified Bradford assay to determine antibody loading onto AuNPs. The conjugates are then mixed with excess HRP to saturate all accessible binding sites, and bound HRP is quantified based on enzymatic reaction rate. This analytical scheme was used to compare two common immobilization strategies, nonspecific adsorption and protein A-mediated immobilization. We found that the antibody surface coverage is greater for direct adsorption than protein A-mediated binding; however, 23 ± 6% of the directly adsorbed antibodies were active, whereas 91 ± 19% of the antibodies bound through protein A were active. In addition to establishing this method as quantitatively precise and accurate, our results emphasize the need to quantify both antibody loading and antibody activity upon conjugation to gain greater insight into differences in immobilization chemistries and identify optimum protein conjugation strategies to maximize immunoassay performance.

Anti oxidant potential of Metformin and Pioglitazone in Type 2 Diabetes Mellitus: Beyond their anti glycemic effect

OBJECTIVE

Insulin sensitizers might influence oxidative stress to improve insulin resistance in diabetes mellitus. The present study was designed with the aim to study the effect of Metformin & Pioglitazone on markers of oxidative stress after 4 weeks of therapy in patients with type 2 diabetes mellitus (Type 2 DM).

RESEARCH DESIGN AND METHODS

This was a prospective study with follow up of 4 weeks in patients with Type 2 DM. They were randomized into metformin treated group (N=20) and Pioglitazone treated group (N=20) and healthy age-matched control group (N=20). Data was presented as mean±S.D. Student "t" test, ANOVA and Pearson correlation co-efficient tests were performed to analyze the parametric data in this study.

RESULTS

Baseline clinical characteristics of the two study groups were similar. There is a significant difference for Fasting plasma glucose (FPG) and 2h-Post Prandial Plasma Glucose (PPPG) after 30 days of metformin and pioglitazone treatment. Metformin significantly reduced MDA (p=0.041) and increased SOD (p<0.001). Pioglitazone significantly reduced MDA (p<0.001) but failed to raise SOD level (p=0.132). Mean MDA was 4.57±0.57μM/L in metformin and 2.91±0.66μM/L in pioglitazone treatment with a p-value of <0.001. Further, a similar significant difference was obtained for SOD value by metformin and pioglitazone treatment (7.87±0.72U/ml vs. 6.94±0.53U/ml; p<0.001).

CONCLUSION

Pioglitazone was superior to Metformin to improve oxidative stress as reflected by reduction in MDA but the antioxidant effect i.e. increase in SOD was seen with metformin only. The differing mechanism of actions of the two drugs on oxidative stress favors co prescription of these drugs for better outcome in improving insulin resistance and diabetic complications.

Cutaneous T-cell lymphomas and their management strategies

Cutaneous T-cell lymphomas (CTCLs) comprise a heterogeneous group of lymphoproliferative disorders characterized by the proliferation of skin-homing post-thymic T-cells. It is the second most common extranodal non-Hodgekin's lymphoma. Many variants of mycosis fungoides and CTCLs are known to date, differing in clinical, histological, and immunophenotypic characteristics. Oral involvement has also been reported rarely in CTCLs. Treatment depends on the disease stage or the type of variant. New insights into the disease and the number of emerging novel therapeutic options have made it an interesting area for dermatologists and medical oncologists.

Study of Mutations in β-Thalassemia Trait among Blood Donors in Eastern Uttar Pradesh

BACKGROUND

Knowledge on distribution of different mutations of thalassaemia, which are prevalent in a particular area, is a prerequisite for prenatal diagnosis.

OBJECTIVES

Studying mutations in β - thalassaemia trait among blood donors in eastern Uttar Pradesh, India.

MATERIAL AND METHODS

One thousand non - remunerated voluntary blood donors who were between 18 - 40 years of age, were included in the study. Both replacement and voluntary healthy blood donors were included. 4ml of venous blood was collected and it was stored at 4°C. Complete Blood Count (CBC), Haemoglobinopathy Screening and Molecular Analysis by ARMS - PCR (Amplification Refractory Mutation System - PCR) were done. Screening for β thalassaemia was done in a blood bank by using D - 10, Bio Rad, which was based on High Performance Liquid Chromatography (HPLC).

RESULTS

Twenty Eight subjects with β- thalassaemia trait were found among 1000 voluntary blood donors. IVS 1-5 (G-C) mutation was most common type (50%), followed by FS 8/9 (+G) 25% which was the second most common type. In our study, a rare mutation of CD 16 (-C) was also found. Out of 14 subjects who had IVS 1-5 (G-C) mutation (most common), six were from Varanasi (6/261) and five of them were Sindhis. It was seen that FS 41/42 (TCTT) mutation was distributed among all groups of populations which had higher prevalences of β-thalassaemia trait.

CONCLUSION

A comprehensive knowledge on beta thalassaemia mutations is necessary for determining a prenatal diagnosis. The occurrence of mutations may vary according to geographic region. Therefore, this study dealt with current problem of unknown mutations, in order to avoid complications.

Kinetic and Mechanistic Study of the Influence of Micelles on the Oxidation of Acetone by N-Bromophthalimide in Aqueous Acetic Acid Medium

The effect of cationic micelles of Cetyltrimethylammonium bromide (CTAB) and anionic micelles of Sodium dodecyl Sulphate (SDS) on the kinetics of oxidation of acetone by N-Bromophthalimide (NBP) was studied iodometrically at 308 K. In addition to kinetic experiments, conductivity measurements have also been done to obtain critical micelle concentration and other thermodynamic properties. The kinetic observations indicate fractional order and first order dependence, with respect to [Acetone] and [NBP] respectively. Cationic surfactant (CTAB) strongly catalysed the oxidation of acetone in aqueous acetic acid medium and typical kobs and [CTAB] profile was observed i.e. with the progressive increase in [CTAB], the reaction rate increased, at higher concentration constancy in kobs was observed, whereas anionic surfactant (SDS) was found to show no considerable effect on reaction rate. Mercuric acetate and phthalimide exhibited nil effect on the reaction rate. The presence of inorganic salts (KCl, KBr) exhibits positive effect in the reaction rate. The various activation parameters in presence of CTAB and SDS have been also evaluated. A suitable mechanism consistent with the experimental findings has been proposed. The binding constant with surfactants has been evaluated.

Pharmacognostical study of Tamalaki (Phyllanthus fraternus Webster), a herb used in Tamaka-svasa

Tamalaki is a herbacious medicinal plant, described in Ayurvedic texts in many occurrences with different properties, actions, uses and synonyms, supposed to indicate more than one species commonly used in practice. Modern scholars mostly suggest Phyllanthus fraternus Webster (syn. P. niruri Linn.), P. amarus Schum. and Thonn. and P. urinaria Linn. as the source plants of Tamalaki. In this study, an attempt has been made to designate P. fraternus as the source plant of Tamalaki used in the treatment of Tamaka-svasa (Bronchial asthma) and other respiratory disorders by analyzing therapeutic uses, actions, properties, taste, synonyms as well as pharmacognostical characters. Smooth capsule, six tepals, less and short fibrous root, pentagonal outline with wing-shaped young stem are some of the specific characters observed in this species.

Synthesis and spectral characterization of ternary mixed-vanadyl β-diketonate complexes with Schiff bases

A new method to synthesize some mononuclear ternary oxovanadium(IV) complexes of the general formula [VO(β-dike)(SB)] (where Hβ-dike=acetylacetone; benzoylacetone or dibenzoylmethane, HSB=Schiff bases) has been explored by stepwise substitutions of acetylacetonate ion of VO(acac)(2) with Schiff bases. The substituted acetylacetone could be fractionated out with p-xylene as an azeotrope. The complexes were characterized by elemental analyses, molecular weight determinations, spectral (electronic, infrared, (1)H NMR, EPR and powder XRD) studies, magnetic susceptibility measurements and cyclic voltammetry. Molar conductance measurements indicated the complexes to be non-electrolytes in nitrobenzene. Bidentate chelating nature of β-diketones and Schiff base anions in the complexes was established by infrared and NMR spectra. Molecular weight determinations confirmed mononuclear nature of the complexes. The EPR spectra illustrated coupling of the unpaired electron with (51)V nucleus (I=7/2). Cyclic voltammograms of all the complexes displayed two-step oxidation processes. The oxidation peak potential corresponded to the quasireversible one-electron oxidation process of the metal center, yielding V(V) species. Transmission electron microscopy (TEM) indicated spherical particles of ∼200 nm diameter. The synthesized complexes are mixed-ligand complexes showing a considerable hydrolytic stability in which vanadium is having coordination number 5. A square pyramidal geometry around vanadium has been assigned in all the complexes.

Pneumatocele in an adult

We report a case of 25-year-old male who presented with high grade fever with cough and expectoration. Chest examination revealed amphoric breath sounds on the right interscapular region. Chest X ray revealed multiple air fluid levels with collapse lung at places. Staph pneumonia with pneumatoceles is common in children but uncommon to in adult population.

Effect of pioglitazone and rosiglitazone on mediators of endothelial dysfunction, markers of angiogenesis and inflammatory cytokines in type-2 diabetes

The purpose of this study was to assess the effects of PPAR-gamma agonists (pioglitazone and rosiglitazone) on mediators of endothelial dysfunction and markers of angiogenesis in patients with type-2 diabetes. Pioglitazone group showed favorable reductions in serum total cholesterol, triglycerides, LDL cholesterol, VLDL cholesterol and increase in HDL cholesterol as compared to rosiglitazone group, after 16 weeks of treatment and also with control group. There was significant reduction of CRP level in pioglitazone and rosiglitazone group. The level of serum TNF-alpha decreased significantly in pioglitazone and mildly decreased in rosiglitazone group. The level of VEGF, IL-8 and Angiogenin were increased in pioglitazone than rosiglitazone group. There were no significant changes observed in the serum angiogenin and IL-8 levels in the control group. Pioglitazone and rosiglitazone therapy in type-2 diabetes subjects have additional benefits of reducing mediators of endothelial dysfunction. Increase in angiogenesis markers in patients receiving pioglitazone could have variable effects in diabetic nephropathy and retinopathy as there may be increased vascular neogenesis. Pioglitazone has advantage over rosiglitazone in lowering lipid and proinflammatory cytokines.

Acanthamoebae presenting as primary meningoencephalitis in AIDS

A rare case of Acanthamoebae meningoencephalitis is diagnosed in cerebrospinal fluid (CSF) of a 24 years old male suffering from acquired immunodeficiency syndrome (AIDS) patient on the basis of bright field microscopy and culture growth on non-nutrient agar with Escherichia coli. This case illustrates that Acanthamoebae should be considered in the differential diagnosis of meningoencephalitis in AIDS in addition to tuberculosis and cryptococcus infection in tropical areas.

Decreasing incidence of renal cortical necrosis in patients with acute renal failure in developing countries: a single-centre experience of 22 years from Eastern India

BACKGROUND

Renal cortical necrosis (RCN) accounts for 2% of all cases of acute renal failure (ARF) in adults and 15-20% of ARF during the third trimester of pregnancy in developed nations. However, RCN incidence is higher in developing countries ranging from 6-7% of all cases of acute renal failure. The present study describes changing trends in the clinical spectrum of RCN in patients with ARF in Eastern India.

METHODS

Patients with ARF suspected to have RCN on clinical grounds underwent percutaneous renal biopsy. Patients showing cortical necrosis on histology were included in the present study. Diffuse and patchy cortical necrosis was classified based on standard histological criteria. The patients with cortical necrosis were studied over a period of 22 years; from July 1984 to December 2005. The results of our observation were compared with respect to etiology, incidence, prognosis and outcome of renal cortical necrosis in two study periods; namely, 1984-1994 and 1995-2005.

RESULTS

The incidence of RCN was 3.12% of all cases of ARF of diverse etiology. RCN was observed in 57 patients; obstetric 32 (56.2%); non-obstetric 25 (43.8%). Diffuse cortical necrosis was the dominant lesion in 41 (71.9%) patients and the remaining 16 (28%) patients had patchy cortical necrosis. The overall incidence of RCN in obstetric ARF was 15.2%; the incidence being higher (11.9%) in the post-abortal group in comparison to 3.3% in late pregnancy. RCN had occurred complicating abruptio placentae, puerperal sepsis and postpartum haemorrhage (PPH) in late pregnancy, while septic abortion was the sole cause of RCN in early pregnancy. Haemolytic uraemic syndrome (HUS) was the major (31.5%) cause of RCN in the non-obstetric group and miscellaneous factors were responsible in seven (12.3%) patients. Partial recovery of renal function was observed in 11 (19.2%), and 16 (28%) patients had progressed to ESRD. The incidence of RCN decreased from 6.7% in 1984-1994 to 1.6% in 1995-2005 of total ARF cases. RCN following obstetrical complication decreased significantly; 4.7% in the 1990s to 0.5% of the total ARF cases, in the 2000s. The mortality decreased to 19% in 1995-2005 from the initial high mortality of 72% in 1984-1994. The renal prognosis improved as a result of the decreased mortality of patients.

CONCLUSION

We observed a decreasing trend in the incidence of RCN in patients with ARF in recent years, which is associated with increased patient survival and better renal prognosis. This improvement was mainly due to declining incidence and severity of RCN in obstetrical ARF.

Effect of glycaemic control on apoptosis in diabetic wounds

OBJECTIVE

To study the effect of glycaemic control on apoptosis in chronic ulcers in diabetic patients and the differential roles of insulin and oral hypoglycaemic agents (OHAs).

METHOD

Ten non-diabetic (group I) and 20 diabetic patients (groups II and III), with a wound of more than four weeks' duration, who were attending the wound clinic at University Hospital, Varanasi, India were recruited. The 10 patients in group 11 received insulin and the 10 in group III an oral hypoglycaemic agent; all had diabetic foot ulcers. Wound biopsy and other routine investigations were performed. Both DNA fragmentation and morphological changes under light microscopy (apoptotic index) were used as determinants of apoptosis. Different variables, including fasting and post-prandial blood sugar, serum low-density lipoprotein (LDL) and markers of microangiopathy, such as proteinuria and diabetic retinopathy, were compared with apoptosis.

RESULTS

DNA fragmentation in groups I, II and III was 40.00 +/- 2.97, 45.26 +/- 3.21 and 60.8 +/- 3.13 respectively (p < 0.01). Near linear correlation was observed with blood sugar level, particularly post-prandial blood sugar (p < 0.05) and DNA fragmentation. DNA fragmentation was significantly correlated with serum LDL and proteinuria, and it was much greater in the OHA group than in the insulin group (p < 0.05). Similarly, in the diabetic patients with background retinopathy the DNA fragmentation was 46.50 +/- 3.42 (n=3) in the insulin group and 66.70 +/- 6.48 (n=4) in the OHA group (p < 0.05).

CONCLUSION

There is a significant increase in apoptosis in diabetic wounds with poorly controlled blood sugar and microangiopathy. This increase was greater in patients on OHAs than those on insulin, and it contributes to delayed wound healing. Morphological markers do not appear to be a reliable index of apoptosis in the diabetic wound.

Primary amyloidosis presenting with predominant lymphnodal masses

A 50 year young farmer presented with clinical features of bilateral carpal tunnel syndrome and generalized lymphadenopathy including paratracheal and retroperitoneal lymphodes. The histological diagnosis confirmed primary amyloidosis of lymphnodes. Presentation of primary amyloidosis as lymphnodal mass with deposition of amyloid in carpal tunnel is extremely rare and can only be diagnosed by histochemistry. The clinical response to drugs is variable and needs surgical intervention for decompressive therapy which can improve the symptoms of carpal tunnel syndrome.

Mucocutaneous lesions in transplant recipient in a tropical country

Dermatological manifestations are common in renal transplant patients, but differ markedly with ethnic group and geographical location. We studied mucocutaneous lesions in 54 renal allograft recipients (related donors = 30; unrelated donors = 24) living in tropical atmospheres. Their gender was 50 males, and 4 females ranging in age between 15 and 63 years (mean = 37.84 years). The mean duration of follow-up was 124 months (range = 4 to 173 months). All patients received kidneys from living donors and were kept on immunosupression with mean daily doses of prednisolone, azathioprine, and cyclosporine of 10.2 mg, 68.6 mg, and 252 mg, respectively. The mean trough concentration of cyclosporine was 185 ng/mL. The mucocutaneous lesions were divided into four groups: drug-induced (n = 24, 44.4%), fungal (n = 18, 33.3%), viral (n = 9, 16.6%), and bacterial (n = 10, 18.5%). Cushingoid features, gum hypertrophy, and hypertrichosis were seen in 7 (12.9%) patients. Steroid acne was seen in three cases. Pityriasis versicolor was the most common (20.3%) fungal infection of the skin. In addition, Tinea unguium and mucocutaneous candidiasis were noted in four and three cases respectively. Herpes virus infection (Herpes zoster 5; Herpes simplex 2) was noted in 7 (12.9%) cases. Chicken pox at 5 years posttransplant and cutaneous vasculitis associated with cytomegalovirus disease at 6 months posttransplant were seen in one case each. We have not seen warts in our patients. Pyogenic bacterial infection of skin in the form of abscess (n = 6), cellulitis (n = 3), and pyoderma (n = 1) were observed in 10 (18.5%) patients. Thus, drug-induced mucocutaneous side effects and skin fungal infections are the most common dermatological manifestations among renal transplant recipients living in a tropical country.

Spectrum of renal disease in malaria

Between January 2000 and December 2001, renal involvement in 81 cases of malaria was studied. Their age ranged between 05 and 66 (mean 35.5) years. Distribution of malarial parasite was P falciparum (75), mixed infection (4) and P vivax (2). The evidence of clinical renal disease in the form of acute renal failure, electrolyte abnormality, abnormal urinary sediment and increased urinary protein excretion (>500 mg/24 hours) was found in 100%, 91.3%, 46.9% and 18.5% respectively. Probable aetiopathogenesis of acute renal failure (ARF) was multifactorial. Volume depletion (72.8%) was the dominant cause of ARF in these patients. In addition, hyperbilirubinaemia, intravascular haemolysis and sepsis were responsible for ARF in 64.2%, 70.3% and 25.9% cases respectively. All the patients were managed with anti-malarial drugs and dialysis support was needed in 35 patients (43.2%). Prognosis of malarial acute renal failure is favourable with mortality rate of 18.5%. Multi-organ failure was the commonest cause (33.3%) of death.

Role of kidney in hypertension

Renin angiotensin system in the genesis of hypertension was established long after Goldblatt's belief that the minute capillaries of the kidney regulate blood pressure and he also suggested kidney released a pressure substance which lead to rise of blood pressure. Guyton provided experimental and analytical data supporting the role of renal pressure natriuresis in the regulation of normal circulation and its function resulting in the pathogenesis of hypertension. Hady and Overbeck proposed that the blood pressure of volume expanded hypertension was raised by a circulating inhibitor of the Na+/K+ ATPase pump. Brenner et al proposed that hypertension may arise from a congenital reduction in the number of nephrons or in the filtration surface area per glomerulus, thereby limiting ability to excrete sodium, raising blood pressure. Renin angiotensin system can be interrupted at four sites by adrenergic blocker, renin inhibitor, angiotensin converting enzyme inhibitor and angiotensin receptor blocker. Non-modulation in the face of relatively high dietary sodium could explain the pathogenesis of sodium sensitive hypertension and provide a more targeted, rational therapy for its correction.

Immunoblot analysis of the humoral immune response to Leishmania donovani polypeptides in cases of human visceral leishmaniasis: its usefulness in prognosis

Sera from Indian patients with parasitologically confirmed visceral leishmaniasis were studied by immunoblot analysis in order to identify a specific pattern for Leishmania infection. A soluble extract of Leishmania donovani was used as antigen. At diagnosis the sera from patients with visceral leishmaniasis specifically recognized fractions represented by bands of 201 kDa (50% of serum samples), 193 kDa (60%), 147 kDa (50%), 120 kDa (60%), 100 kDa (50%), 80 kDa (80%), 70 kDa (70%), 65 kDa (100%), 50 kDa (50%), 36 kDa (50%), 20 kDa (70%), and 18 kDa (50%). The 65-kDa band, common to all patients infected with Leishmania parasites, was found at the time of diagnosis. However, the immunoblot pattern changed after patients were treated and cured with sodium antimony gluconate (SAG; n =10) or miltefosine (n =10), as was evident from blots of sera obtained pretreatment and at 1, 3, and 6 months posttreatment. At 6 months posttreatment, immunoblots of sera from patients on the SAG regimen showed the disappearance of all bands except the 70-kDa band. Similarly, sera from those on the miltefosine regimen showed the disappearance of all bands except the 65- and 70-kDa bands. This study shows that Western blot analysis is a sensitive test for detection of anti-Leishmania antibodies. Moreover, the persistence of reactivity with the 65- and 70-kDa bands in the sera of all groups shows its promise as a diagnostic and prognostic tool.

An experimental study of some indigenous drugs with special reference to hydraulic permeability

The effect of commonly used indigenous drugs for hepatic disorders i.e. Tinospora cordifolia, (Guduchi/Amrita), Andrographis paniculata (Kalmegha), Picrorhiza kurroa (Kutki), Phyllantnus niruri (Bhoomyamalaki) and Berberis aristata (Daruharidra) was tested on the hydraulic permeability of water in the presence of bile salt through a transport cell model. The data on hydraulic permeability were calculated as t (time). JV = Lp x AP, where Lp = hydraulic conductivity and AP is the pressure difference. It was observed that the value of controlled hydraulic permeability (0.49 x 10(-8) M3 S(-1) N(-1)) decreased in the presence of indigenous drugs and bile salt. The results suggest that these drugs might have the cell membrane stabilizing property which may lead to prevention of the toxic effect of bile salts in various hepatic disorders.

A study of prostane in the treatment of benign prostatic hyperplasia

A clinical trial was conducted in a study group of 70 males diagnosed with symptomatic benign prostatic hypertrophy (BPH) (synonym of benign prostatic hyperplasia). They were administered Prostane, a herbal formulation, at a dose of two tablets a day for 1 year and monitored every 4 months during the study period. Analysis of the results showed an improvement in the symptom score of the American Urological Association symptom index rating. There was total relief in pain and haematuria in all the patients (100%); dribbling of urine decreased in 67%, dysuria in 50%, urgency in 60% and hesitancy in 40%. Blood urea levels were within the normal range in 70% of the patients and in the range 31-40 mg/dL in the remaining patients of the study group. Serum prostate specific antigen levels returned to normal in 56% of patients and were in the range 4.1-5.0 ng/mL in 25% of patients. There was a decrease in prostate specific antigen values which were >6 ng/mL in 9 patients at the commencement of the trial. Uroflowmetry studies showed that the peak flow increased from 12.6 to 30.7 s (p<0.001) and the void volume from 60.72 to 660 mL (p<0.001), the latent period reduced from 12.78 s to 2.61 s; the flow time from 57.01 s to 20.17 s and the residual volume from 620 mL to 20 mL (p<0.001). From these results, it is evident that Prostane was effective in alleviating symptoms, reducing prostate specific antigen values and normalizing uroflow dynamics in patients with benign prostatic hypertrophy.

Assessment of carbonic anhydrase activity in blood by alteration in pH

Carbonic anhydrase enzyme activity could be measured by manometeric and colorimetric techniques. A simpler and modified method of carbonic anhydrase enzyme activity assessment in blood is proposed. In the present method differences in pH by hydration of CO2 in absence and presence of carbonic anhydrase inhibitor have been used to measure the carbonic anhydrase activity in the blood.

Renal cortical necrosis in pregnancy-related acute renal failure

Of 63 patients of obstetrical acute renal failure, 15 cases (23.8%) had biopsy proven bilateral renal cortical necrosis. Remaining 48 patients (76.2%) had acute tubular necrosis. Eight of 39 cases in early pregnancy had cortical necrosis (postabortum) and 7 of 24 patients in late pregnancy revealed cortical necrosis. Diffuse and patchy cortical necroses were seen in 12 and 3 patients respectively. The incidence of cortical necrosis was almost equal in both early as well as late pregnancies. The high incidence (20.5%) of cortical necrosis following septic abortion remains the interesting feature of the present study in contrast to very low incidence (1.5%) of cortical necrosis in postabortum group in developed countries. The death occurred in most patients (14 ie, 93.3%) of cortical necrosis because of uraemic complications and sepsis.

Acute renal failure in eastern India

The present study included 426 patients with acute renal failure age range 7 months to 85 years, during 8-year period (1984-1992). Medical, surgical and obstetric causes were responsible for ARF in 68.3, 17.8, and 14% of cases respectively. The main aetiological factors encountered were volume depletion secondary to gastrointestinal fluid loss (35.2%), acute glomerulonephritis (10.3%), nephrotoxin (8.6%), falciparum malaria (4.2%), obstructive uropathy (13%), post-abortal (10.5%), and miscellaneous factors (1.4%) of patients. The overall mortality was 19.2%. Thus our observation revealed that diarrhoeal diseases (35.2%), obstructive uropathy (13.3%), and septic abortion (10.5%) were the main causes for ARF in medical, surgical, and obstetric groups respectively. In contrast to our studies, acute renal failure associated with diarrhoeal diseases, septicaemia, falciparum malaria and septic abortion are rare in European countries.

Spectrum of renal cortical necrosis in acute renal failure in eastern India

Renal cortical necrosis is an uncommon cause of acute renal failure. We report 23 cases of biopsy-proven renal cortical necrosis which constituted 6.3% (23/363) of all cases of acute renal failure studied over a period of seven years (1985-92). The patients were divided into two groups: obstetric and non-obstetric. Obstetric complications were responsible for renal cortical necrosis in 15 (65.2%) patients while non-obstetric conditions accounted for the remaining eight (34.8%) cases. The overall incidence of cortical necrosis in obstetric acute renal failure was 15/63 (23.8%) patients, the incidence being nearly equal in early (20.5%) and late (29%) pregnancy. Post-abortum renal failure was the sole cause of cortical necrosis in early pregnancy in the obstetric group. Haemolytic uraemic syndrome (three patients) and septicaemia (two patients) were the main cause of necrosis in the non-obstetric group. The cortical necrosis was diffuse and patchy in 17 and six patients, respectively. The disease had a fatal prognosis in 20 (87%) patients; mortality was due to uraemic complications and infections in the majority of patients. The high frequency of post-abortum renal cortical necrosis in our patients is similar to the experience of other Indian workers.

Complications of percutaneous renal biopsy

Three hundred twenty renal biopsies were done in 305 patients over a period of 5 years. Adequate tissue for pathologic diagnosis was obtained in about 79% of biopsy attempts. The overall morbidity of procedure was 6.8%. Haematuria in 11.8% cases was the commonest complication. Haematuria resolved spontaneously in 63.8% of patients within 4-12 hours. Hypotension due to blood loss occurred in 3 patients (0.98%) who required blood transfusion. Five patients (1.6%) developed perirenal haematoma. Urinary retention requiring single catheterisation was seen in 12 cases (3.9%). Perirenal abscess occurred in one case. Minor complications improving with symptomatic medication included vomiting, abdominal pain and vasovagal attack in 3.6%, 2.6% and 1.6% cases respectively.

Clinical significance of kidney biopsy in acute renal failure (ARF)

Out of 152 cases of Acute renal failure (ARF) 32 patients (21%) were subjected to kidney biopsy. All patients had intrinsic ARF. Prerenal azotemia and obstructive uropathy were excluded. Histologic observations were: Crescentric glomerulonephritis in 7 (21.9%), acute endocapillary proliferative glomerulonephritis 5 (15.6%), acute interstitial nephritis 7 (21.9%), necrotizing vasculitis 4 (12.5%), acute tubular necrosis in 5 (15.6%) and membrano-proliferative GN with superimposed crescent in 2 (6.2%) while renal cortical necrosis was seen in 6.2% of cases. Prebiopsy diagnosis was correct in only 10 (31.25%) cases. The result of biopsy had altered clinical diagnosis in 22 (68.75%) patients and precise renal biopsy diagnosis resulted in therapeutic changes in 54.8% of patients with ARF.

Complications of intermittent peritoneal dialysis

Two hundred and ninety three sessions of intermittent peritoneal dialysis were carried in 158 cases of renal failure between 1984 and 1987. The complications encountered during the procedure were grouped as mechanical in 29 (17.9%), circulatory in 26 (15%), neurologic in 21 (13.4%) and biochemical in 54 (34.1%) cases. Unexplained respiratory arrest with spontaneous recovery occurred in 2, infections in 5 and miscellaneous complications in 19 (12%) cases. Bradycardia and cardiac standstill were observed in one patient. Most of the complications were managed uneventfully. There was no mortality.