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Biomedical subjects

P K Srivastava

Publications and source records attributed to P K Srivastava.

At least 19 recordsLinked to original sources
PubMed2006

Acute renal failure in pregnancy in a developing country: twenty years of experience.

UNLABELLED: Acute renal failure (ARF) has become a rare complication of pregnancy in developed countries. The aim of this study was to describe changing trends in pregnancy-related acute renal failure (PR-ARF) in two successive periods; 1982-1991 and 1992-2002. From July 1982 to December 2002, 190 cases of PR-ARF were observed in Eastern India (11.6% of total number of ARF needing dialysis). Obstetrical complications were causative factors for ARF in 15% (65/426) and 10% (125/1201) of patients in the two periods, respectively. The incidence of PR-ARF fell from 15% in 1982-1991 to 10% in 1992-2002, with respect to the total number of acute renal failure cases. Post-abortal ARF showed a declining trend, 9% in the 1980s to 7% in the 2000s, of the total number of ARF cases. Preeclampsia-eclampsia was the cause of obstetrical ARF in 23% (1982-1991) and 14.4% (1992-2002) of cases in these two periods. The percentage of total ARF due to eclampsia declined from 3.5% during the period 1982-1991 to 1.4% in 1992-2002. Puerperal sepsis contributed to 0.8% of total ARF in recent years, compared to 2.4% in the earlier period. The incidence of cortical necrosis decreased significantly (p < 0.001) from 17% in 1982-1991 to 2.4% in the 2000s. The maternal mortality reduced to 6.4% in 1992-2002 from initial high mortality of 20% in the period of 1982-1991. CONCLUSION: PR-ARF which remained high in the initial period has decreased in recent years. This is associated with a declining trend in

Abortion, Induced↗
PubMed2005

Letrozole for brain and scalp metastases from breast cancer--a case report.

Brain metastases from breast cancer have a poor prognosis. There have been reports of patients with breast cancer and brain metastases responding well to tamoxifen therapy. We report a very unusual case of intact breast carcinoma with brain as well as scalp metastasis responding well to letrozole (aromatase inhibitor) therapy for a prolonged period of time.

Aromatase Inhibitors↗
PubMed2004

Stakeholder-based SWOT analysis for successful municipal solid waste management in Lucknow, India.

The present investigation is a case study of Lucknow, the main metropolis in Northern India, which succumbs to a major problem of municipal solid waste and its management. A qualitative investigation using strengths, weaknesses, opportunities and threats analysis (SWOT) has been successfully implemented through this community participation study. This qualitative investigation emphasizes the limited capabilities of the municipal corporation's resources to provide proper facilitation of the municipal solid waste management (MSWM) services without community participation in Lucknow city. The SWOT analysis was performed to formulate strategic action plans for MSWM in order to mobilize and utilize the community resources on the one hand and municipal corporation's resources on the other. It has allowed the introduction of a participatory approach for better collaboration between the community and municipal corporation in Lucknow (India). With this stakeholder-based SWOT analysis, efforts were made to explore the ways and means of converting the possible "threats" into "opportunities" and changing the "weaknesses" into "strengths" regarding a community-based MSWM programme. By this investigation, concrete strategic action plans were developed for both the community and municipal corporation to improve MSWM in Lucknow.

Cities↗
PubMed2004

Effect of risperidone on prolactinoma--a case report.

Risperidone induced galactorrhea and hyperprolactinemia have been reported but its role in the growth of prolactinoma is not yet conclusive, due to extreme rarity of such cases. We describe a woman, suffering from Bipolar Disorder-manic episode, who exhibited prolactinoma while on risperidone therapy. The withdrawal of risperidone resulted in disappearance of prolactinoma though her prolactin level remained elevated along with persistent galactorrhea. The change to olanzapine therapy did not show much change in serum prolactin level and galactorrhea. Ultimately, only adding of bromocriptine resulted in disappearance of symptoms of prolactinemia and normal serum prolactin level was achieved and galactorrhea stopped. Further study is recommended to find out relationship between the growth of prolactinoma and risperidone.

Adult↗
PubMed2002

Persistent organochlorine pesticide residues in milk and dairy products in India.

Monitoring of milk and dairy product samples of various brands from different cities in Maharashtra, India, was carried out to determine if there is any contamination due to organochlorine pesticide residues. The measurements were made using a gas chromatograph-electron capture detector system. Trace levels of DDT and HCH were detected in the samples. Total HCH levels in milk and milk product samples were lower than total DDT levels, which could be attributed to earlier extensive antimalaria sanitary activities. Butter had higher levels of DDT than cheese and milk powder. All levels of organochlorine pesticide residues in milk and milk products were well below the maximum permissible limits given by the FAO/ WHO. More importantly, as compared with an earlier report, present levels of the contaminants are substantially lower, which indicate the gradual phase out of these compounds.

Animals↗
PubMed2002

Case report. Orbital metastasis from gall bladder carcinoma.

Clinical presentation of an extraabdominal metastasis from carcinoma of the gall bladder is rare. Orbital metastasis from gall bladder carcinoma has not been previously reported. We report a case of a 40-year-old woman who developed orbital metastasis from carcinoma of the gall bladder.

Adenocarcinoma↗
PubMed2001

Monitoring of indoor volatile organic compounds and polycyclic aromatic hydrocarbons arising from kerosene cooking fuel.

Air samples, representing indoor environments of a kitchen in which a kerosene stove was used were collected and analysed for volatile organic compounds (VOCs) viz., n-hexane, benzene, heptane, toluene, p- and o-xylene and n-decane using a cryogenic preconcentration system and a gas chromatograph with a flame-ionisation detector. Simultaneous outdoor samples were also collected to determine indoor to outdoor (I/O) ratios for each compound. Reversed phase high performance liquid chromatography (HPLC) with ultra violet absorption detection was optimised for separation and quantification of polycyclic aromatic hydrocarbons (PAHs) in air particulate matter. Concentration of total suspended particulate matter (TSPM), benzene soluble organics and the PAHs in air samples collected in indoor environment of some tenements at Trombay, Mumbai where kerosene is used as cooking fuel are discussed in relation to the concentration of the same in outdoor environment in vicinity of the tenement. VOCs and PAHs results from samples collected in kitchens in Trombay are discussed in relation to indoor air pollution.

Air Pollution, Indoor↗
PubMed2001

An endoplasmic reticulum protein implicated in chaperoning peptides to major histocompatibility of class I is an aminopeptidase.

gp96, an abundant peptide-binding chaperone of the lumen of the endoplasmic reticulum and an acceptor of peptides transported into the endoplasmic reticulum through transporter associated with antigen processing, is shown to be an aminopeptidase. gp96 can trim an amino-terminal extended 19-mer precursor of the K(b)-binding VSV8 epitope for recognition by the cognate cytotoxic T lymphocyte clone. These observations support a role for gp96 in the amino-terminal trimming of extended peptides in the endoplasmic reticulum.

Aminopeptidases↗
PubMed2001

Adjuvanticity of alpha 2-macroglobulin, an independent ligand for the heat shock protein receptor CD91.

We recently have identified CD91 as a receptor for the heat shock protein gp96. CD91 was identified initially as a receptor for alpha(2)-macroglobulin (alpha(2)M). Gp96 and alpha(2)M are both ligands for CD91. Because gp96-chaperoned peptides can prime CD8(+) T cell responses and are re-presented by APCs, we tested alpha(2)M for similar properties. Our studies show that alpha(2)M binds peptides in vitro and that the peptides, chaperoned by alpha(2)M, efficiently prime peptide-specific CD8(+) T cell responses in mice immunized with alpha(2)M-peptide complexes. Furthermore, peptides chaperoned by alpha(2)M, like those chaperoned by gp96, can be re-presented by CD91(+) APCs on their MHC I molecules. These studies demonstrate that alpha(2)M molecules, like the heat shock protein molecules, are T cell adjuvants that can channel exogenous Ags into the endogenous pathway of Ag presentaion. The remarkable similarities between an intracellular chaperone and an extracellular serum chaperone may have interesting physiological ramifications.

Adjuvants, Immunologic↗
PubMed2001

Identification of a tumor-associated contact-dependent activity which reversibly downregulates cytolytic function of CD8+ T cells.

Tumors elicit an immune response in hosts and yet, paradoxically, often grow progressively with fatal consequences. This phenomenon has been attributed to the possible expression by tumor cells of immunomodulatory factors that overcome the anti-tumor effector functions of both specific and non-specific immune cells. This study reports on the ability of the methylcholanthrene-induced fibrosarcoma, Meth A, as well as other tumors of varied histological origins to downregulate the lytic activity of CD8+ T cells. The suppressive activity is contact-dependent and reversible. As tumor-bearing hosts are rarely immunosuppressed systemically, these findings may explain how local events within the tumor bed subvert the specific anti-tumor immune response.

Animals↗
PubMed2001

The immunoprotective MHC II epitope of a chemically induced tumor harbors a unique mutation in a ribosomal protein.

CD4(+) T lymphocyte clones, generated from mice immunized with the methylcholanthrene-induced fibrosarcoma Meth A (H-2(d)), are restricted by I-E(d) and recognize a unique antigen on Meth A. The antigen has been purified and characterized as the ribosomal protein L11. The antigenic epitope is contained within the sequence EYELRKHNFSDTG and is generated by substitution of Asn by His (italic) caused by a single point mutation. The tumor contains the wild-type and the mutated alleles. Immunization of BALB/cJ mice with the mutated epitope but not with the wild-type epitope protects mice against a subsequent challenge with the Meth A sarcoma. Adoptive transfer of CD4(+) clones into BALB/c mice renders the mice specifically resistant to Meth A sarcoma. The mutated L11 epitope is thus shown to be an immunoprotective epitope in vivo by several criteria.

Amino Acid Sequence↗
PubMed2001

Heat shock proteins: the 'Swiss Army Knife' vaccines against cancers and infectious agents.

The ability of heat shock proteins to: (a) chaperone peptides, including antigenic peptides; (b) interact with antigen presenting cells through a receptor; (c) stimulate antigen presenting cells to secrete inflammatory cytokines; and (d) mediate maturation of dendritic cells, makes them a one-stop shop for the immune system. These properties also permit the utilization of heat shock proteins for development of a new generation of prophylactic and therapeutic vaccines against cancers and infectious diseases.

Adjuvants, Immunologic↗
PubMed2001

Heat shock protein-chaperoned peptides but not free peptides introduced into the cytosol are presented efficiently by major histocompatibility complex I molecules.

The studies reported here bear on the events in the cytosol that lead to trafficking of peptides during antigen processing and presentation by major histocompatibility complex (MHC) I molecules. We have introduced free antigenic peptides or antigenic peptides bound to serum albumin or to cytosolic heat shock proteins hsp90 (and its endoplasmic reticular homologue gp96) or hsp70 into the cytosol of living cells and have monitored the presentation of the peptides by appropriate MHC I molecules. The experiments show that (i) free peptides or serum albumin-bound peptides, introduced into the cytosol, become ligands of MHC I molecules at a far lower efficiency than peptides chaperoned by any of the heat shock proteins tested and (ii) treatment of cells with deoxyspergualin, a drug that binds hsp70 and hsp90 with apparent specificity, abrogates the ability of cells to present antigenic peptides through MHC I molecules, and introduction of additional hsp70 into the cytosol overcomes this abrogation. These results suggest for the first time a functional role for cytosolic chaperones in antigen processing.

Amino Acid Sequence↗
PubMed2001

CD91 is a common receptor for heat shock proteins gp96, hsp90, hsp70, and calreticulin.

Complexes of the heat shock protein gp96 and antigenic peptides are taken up by antigen-presenting cells and presented by MHC class I molecules. In order to explain the unusual efficiency of this process, the uptake of gp96 had been postulated to occur through a receptor, identified recently as CD91. We show here that complexes of peptides with heat shock proteins hsp90, calreticulin, and hsp70 are also taken up by macrophages and dendritic cells and re-presented by MHC class I molecules. All heat shock proteins utilize the CD91 receptor, even though some of the proteins have no homology with each other. Postuptake processing of gp96-chaperoned peptides requires proteasomes and the transporters associated with antigen processing, utilizing the classical endogenous antigen presentation pathway.

Animals↗
PubMed2001

Characterization of gelatin-immobilized pigeonpea urease and preparation of a new urea biosensor.

Urease purified from pigeonpea seeds was immobilized on gelatin beads via cross-linking with glutaraldehyde. The maximum immobilization (75%) was observed at 30 mg/ml gelatin, 0.414 mg of enzyme/bead, 1% (v/v) glutaraldehyde and 4 degrees C. Beads stored in 50 mM Tris/acetate buffer (pH 7.3) at 4 degrees C showed a half-life of 240 days and there was practically no leaching of enzyme (less than 2%) over a period of 30 days. These beads can be reused more than 30 times (with 24 h intervals) without much loss of enzyme activity (i.e. less than 11%). The immobilized urease showed a shift in its optimum pH from 7.3 to 6.5 in Tris/acetate buffer. Optimum temperature also shifted from 47 to 65 degrees C compared with the soluble enzyme. Gelatin-immobilized pigeonpea urease had a higher K(m) (8.3 mM) than that of the soluble enzyme (3.0 mM). The time-dependent temperature inactivation pattern was also found to change from biphasic to monophasic kinetics. The immobilized beads were used for the preparation of a new urea biosensor with a response time of less than 2 min. At least 14 samples of urea can be measured with this biosensor within an hour. The beads, as well as the biosensor, were used to analyse the urea content in clinical samples from the local clinical pathology laboratories. The results obtained with the biosensor were strikingly similar to those obtained with the various commonly employed biochemical/autoanalyzer(R) methods used. These immobilization studies also have a potential role in haemodialysis machines that maintain the urea level in kidney patients and in the construction of a portable/wearable kidney. The easy availability of the pigeonpea urease, the ease of its immobilization on gelatin and a significantly lower cost of the urease described in the present study makes it a suitable product for future applications in therapeutics and diagnostics.

Biosensing Techniques↗