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Biomedical subjects

Satish Kumar

Publications and source records attributed to Satish Kumar.

49 records · Page 3Linked to original sources

Tamm-Horsfall protein knockout mice are more prone to urinary tract infection: rapid communication.

BACKGROUND: Human colon contains many bacteria that commonly colonize the perineum and frequently enter the urinary tract. Uropathogenic Escherichia coli are the most common cause of urinary tract infection. Type 1 fimbriated E. coli have been associated with cystitis, and P fimbriated E. coli with pyelonephritis. Factors involved in clearing bacteria from the urinary tract are poorly understood. Tamm-Horsfall protein (THP), the most abundant protein in mammalian urine, has been postulated to play a role in defense against urinary tract infection but definitive proof for this idea has been lacking. METHODS: In this study, we generated THP gene knockout mice by the technique of homologous recombination, and examined if the THP-deficient (THP-/-) mice were more prone to urinary tract infection. Various strains of E. coli expressing type 1 or P fimbriae were introduced transurethrally into the bladders of the THP-/- and genetically similar wild-type (THP+/+) mice. Urine, bladder, and kidney tissues were obtained from the mice and cultured for bacterial growth. RESULTS: THP-/- mice inoculated with type 1 fimbriated E. coli had a longer duration of bacteriuria, and more intense colonization of the urinary bladder in comparison with THP+/+ mice. When inoculated with a P fimbriated strain of E. coli, the THP-/- mice showed no difference in kidney bacterial load when compared with the THP+/+ mice. CONCLUSION: These findings support the idea that THP serves as a soluble receptor for type 1 fimbriated E. coli and helps eliminate bacteria from the urinary tract.

Animals↗

Levels of antibody, free antigen and immune-complexed antigen by ELISA in different grades of sputum positive patients of pulmonary tuberculosis.

The ES-31 (31 kDa protein) antigen was isolated from culture filtrate of Mycobacterium tuberculosis H37Ra and was shown to have potential in immunodiagnosis of pulmonary tuberculosis. Serum samples from 38 confirmed sputum positive pulmonary tuberculosis patients were grouped into AFB+, AFB++, AFB+++ based on sputum bacillary load. Analysis of tubercular antibody, circulating free and immune complexed antigen (CIC-Ag) was done in serum samples by Indirect and Sandwich ELISA using ES-31 antigen and affinity purified anti ES-31 antibody respectively. The analysis of Geometric mean titre (GMT) of all the three groups showed that GMT of tubercular antibody was considerably decreased compared to elevated levels of CIC-Ag (Antibody: 1360 to 816 and CIC-Ag: 534 to 1744) from low bacillary sample to high bacillary samples, whereas there is no significant change in the titre of circulating free antigen. Low levels of detectable antibody is observed possibly due to removal of antibody from circulation by immune complex formation as confirmed by its elevated levels in sputum AFB+++ positive patients.

Antibodies, Bacterial↗

[Elective stent treatment of abdominal aortic aneurysm].

BACKGROUND: First described in 1991, endovascular treatment is a simplified method for abdominal aortic aneurysm repair (EVAR). The enthusiasm created by few complications and early mobilisation was replaced by scepticism because of the high frequency of secondary complications such as endoleak, stenosis, graft migration, aneurysm enlargement and late rupture. Though the method still is considered experimental, thousands of grafts are inserted every year. MATERIAL AND METHODS: From 1998, 53 patients underwent EVAR electively at our institution, 17 of whom were for medical reasons considered inoperable in open surgery. They were followed up with CT scans, which together with angiograms were evaluated retrospectively. Co-morbidity and complications were registered. Follow up was at 26 (4-50) months for 49 patients. RESULTS: Two patients died. There were two other complications in addition to two superficial wound infections. There were no surgical conversions. 18 patients had 25 secondary interventions. Cumulative intervention rate was 25% after 12 months, 28% after 24 months and 53% after 36 months. Four stenoses were seen the first 6 months. 19 patients had an endoleak (1 had type I after 24 months, 6 had type II endoleak, 5 had type III endoleak of which two appeared after 3 years). Graft migration was observed in 9 patients (5 at 3 years control). Two ruptures were corrected with endovascular technique. Survival and interventions were equal among inoperable and operable patients. INTERPRETATION: Few early complications are overshadowed by the frequent and unpredictable late complications after EVAR; patients have to be followed up for years. For patients unfit for open surgery this is, however, an optional treatment if intervention is otherwise indicated.

Aged↗

[Local thrombolysis with stent implantation in a patient with vena cava superior syndrome].

BACKGROUND: Vena cavasuperior syndrome is a well-known complication to ventriculoatrial shunts in children and adults. The basis for this is thrombosis. MATERIAL AND METHODS: A patient with hydrocephalus had a ventriculoatrial shunt in his first month of life. More than 30 years later he developed vena cava superior syndrome following abdominal surgery. Diagnostic venography revealed thrombosis in the proximal veins of his arms, neck and vena cava superior. RESULTS AND INTERPRETATION: He was treated with catheter-directed thrombolysis with antegrade infusion of alteplase (Actilyse). Evaluation of thrombolytic treatment after one day revealed a significant stenosis in the superior caval vein in the same area as the shunt had ended. Venoplasty and stent implantation were performed, and an intraluminal diameter of 10 mm was reached. Complete thrombolysis was achieved after 48 hours' infusion of alteplase. His swellings subsided the following two weeks and control venography 6 months later showed no signs of rethrombosis or restenosis. His life-threatening condition was successfully treated with local thrombolytic therapy, venoplasty and stent implantation.

Adult↗

Facial palsy as first presentation of acute myeloid leukemia.

Granulocytic sarcoma or chloroma is a tumor composed of myeloblast or monoblast. These tumors may be found in any location of the body and occur in 5% of acute myeloid leukemia (AML) cases and are more common in pediatric patients. In this report we describe the case of a 27-year-old male who developed lower motor neuron seventh nerve palsy followed by swelling of the parotid gland. Fine-needle aspiration cytology (FNAC) of the soft tissue swelling revealed scattered blasts, and peripheral smear and bone marrow aspirate examination suggested AML. This is a rare presentation of a granulocytic sarcoma leading to a diagnosis of AML.

Adult↗

A highly conserved human gene encoding a novel member of WD-repeat family of proteins (WDR13).

We have identified and characterized a novel member of the WD-repeat motif gene family, WDR13, which contains 9 exons and 8 introns. The gene has been mapped to the genomic locus Xp11.23 by fluorescent in situ hybridization and in silico mapping. Sequence analysis has revealed a continuous open reading frame (ORF) encoding for 485 amino acids with six WD motifs. The expression of this gene has been detected in all the tissues analyzed with significantly varied expression levels among the tissues studied. Analysis of EST clones from various tissues, showing significant homology to WDR13, has identified two spliced variants. The transcription start point has been mapped. Promoter analysis has identified high activity in the 5' UTR, which interestingly showed a testis-specific activity in the transgenic animals studied. The subcellular localization of the WDR13 protein in the nucleus suggests that it may also have a regulatory role in nuclear function along with protein-protein interaction like other members of the WD family of proteins.

5' Untranslated Regions↗

Seroreactivity of 31 kDa and 41 kDa mycobacterial secretory proteins isolated from culture filtrate in extra pulmonary tuberculosis.

Despite rapid advances in molecular genetics for detection of mycobacteria, it is clear that interest in serodiagnosis remains high, especially for those situations in which a specimen may not contain the infecting agent in particular in extrapulmonary tuberculosis. Immune response to excretory-secretory (ES) proteins of Mycobacterium tuberculosis (M.tb) has been of diagnostic interest in tuberculosis. In earlier study from our laboratory, a secretory protein M.tb ES-31 has been shown to have diagnostic potential in pulmonary tuberculosis. Further, another M.tb H37Ra ES protein (ES-41) was isolated and purified by trichloroacetic acid solubilization followed by Fast Performance Liquid Chromatography (FPLC). These two protein fractions viz ES-31 and ES-41 secreted by M.tb H37 Ra bacilli were employed in stick indirect penicillinase ELISA to study seroreactivity in extra pulmonary tuberculosis namely tuberculous lymphadenopathy, tuberculous meningitis, abdominal tuberculosis and bone & joint tuberculosis. While using ES-31 antigen 88% (22/25) of tuberculous lymphadenopathy and 90% (9/10) of tuberculous meningitis cases showed positive reaction for tuberculous IgG antibody, ES-41 showed 80% positivity in both groups. In abdominal and bone & joint tuberculosis cases, ES-41 antigen showed better sensitivity of 81.5% (22/27) and 84.6% (22/26) respectively in IgG antibody detection compared to 70% (19/27) and 69.2% (18/26) shown by ES-31. This study is of interest that different antigen protein fractions of M.tb exhibit differential seroreactivity, as ES-31 protein showed good potential in detecting tuberculous IgG antibodies in tuberculous lymphadenopathy (TBLN) & tuberculous meningitis (TBM), while ES-41 in abdominal and bone & joint tuberculosis cases.

Antibodies, Bacterial↗

Vibration-induced interfacial instabilities in viscoelastic fluids.

Vertically vibrated interfaces between viscoelastic fluids may arise in contexts as diverse as ultrasonic emulsification, microgravity materials processing, and geophysics. If the vibration amplitude is large enough at a given frequency, the interface can become unstable and give rise to standing waves. The present work provides a linear analysis of this phenomenon for the cases where either or both of the fluids are viscoelastic. The fluids are assumed to be laterally unbound, and Floquet theory is used to develop a recursion relation between the temporal modes of the interfacial deformation. Conversion of this relation into a matrix eigenvalue problem allows determination of the critical vibration amplitude needed to excite the standing waves and the corresponding critical wave number. Using a single-mode Maxwell model to describe the viscoelasticity and considering infinite fluid depths, we present calculations for three cases: bottom fluid viscoelastic/top fluid Newtonian, bottom fluid Newtonian/top fluid viscoelastic, and both fluids viscoelastic. When only one of the fluids is viscoelastic, the interfacial waves can respond harmonically to the forcing. The waves may also be excited more easily than in the case where both fluids are Newtonian. When both of the fluids are viscoelastic, it appears possible to excite Stoneley-like waves at the interface.

Journal Article↗

Differential conformational environment of tryptophan in epsilon native prototoxin and active toxin from Clostridium perfringens type D.

The tryptophan content of Clostridium perfringens type D epsilon protoxin and toxin was found to be one residue per molecule of protein. N-bromosuccinimide in the presence of urea cleaves the tryptophan with total loss of lethality in both toxin and prototoxin. Fluorescence spectroscopy, circular dichroism (CD) and 10% ethylene glycol solvent perturbation studies showed that the tryptophan in epsilon toxin and that in prototoxin have different conformational environments. The tryptophan is more on the surface in the prototoxin than in the toxin molecule. NBS causes total loss of lethality of the toxin with its ellipticity coming to almost zero in the near UV region of the CD.

Animals↗

Anterior mediastinal teratoma presenting as cardiac tamponade.

Anterior mediastinal teratoma presenting clinically as cardiac tamponade is unusual. We report the case of a 58-year-old woman, with an unremarkable prior history, who was admitted with cardiac tamponade. Emergency pericardial aspiration showed a thick, yellow fluid. Computed tomography scan of the chest was suggestive of anterior mediastinal teratoma rupturing into the pericardium. Within 24 hours, just before the planned surgery could be performed, it re-ruptured, warranting emergency surgery. Histopathology confirmed the diagnosis of a teratoma. Early surgery is recommended for even asymptomatic benign mediastinal teratomas to avoid this potentially lethal complication of rupture into the pericardial cavity, and cardiac tamponade.

Cardiac Tamponade↗

Challenges of maternal mortality reduction and opportunities under National Rural Health Mission--a critical appraisal.

Maternal Mortality Ratio (MMR) continues to remain high in our country without showing any declining trend over a period of two decades. The proportions of maternal deaths contributed by direct obstetric causes have also remained more or less the same in rural areas. There is a strong need to improve coverage of antenatal care, promote institutional deliveries and provide emergency obstetric care. Delays occur in seeking care for obstetric complications and levels of 'met obstetric need' continue to be low in many parts of the country. Most of the First Referral Units (FRUs) and CHCs function at sub-optimal level in the country. National Rural Health Mission (NRHM) offers institutional mechanism and strategic options to reduce high MMR. 'Janani Suraksha Yojna', strengthening of CHCs (as per Indian Public Health standards) to offer 24 hours quality services including that of anesthetists and Accredited Social Health Activist (ASHA) are important proposals in this regard. District Health Mission can play an important role in monitoring maternal deaths occurring in hospitals or in community and thus create a social momentum to prevent and reduce maternal deaths. NRHM, however, depends largely on Panchayati Raj Institutions for effective implementation of proposed interventions and utilization of resources. In most parts of our country, State Governments have not empowered PRIs with real devolution of power. Therefore, much needs to be done locally to build the capacity of PRIs and develop state-specific guidelines in operational terms to implement interventions under NRHM for reducing maternal mortality ratio.

Community Health Workers↗