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Biomedical subjects

T Das

Publications and source records attributed to T Das.

At least 127 records · Page 7Linked to original sources
PubMed1993

Guidelines for the management of rhegmatogenous retinal detachment.

Current techniques of rhegmatogenous retinal detachment repair allow most detachments to be repaired successfully. The success of repair depends on a careful pre-operative examination and choice of an appropriate procedure. The surgery is usually tailored to individual needs. Improvements in surgical techniques coupled with a better understanding of the pathophysiology of rhegmatogenous retinal detachment continue to improve the anatomic and functional success of retinal detachment repair.

Humans↗
PubMed1992

A 55-year followup of a patient with bilateral ureterosigmoidostomy.

We report on a patient with bilateral ureterosigmoidostomy who, despite many of the long-term complications associated with the procedure, was doing well 55 years after urinary diversion. This is one of the longest follow-ups reported in the literature. Despite the decreasing popularity of ureterosigmoidostomy, in well selected patients who desire a continent form of internal diversion it may still prove to be useful, as exemplified by our patient.

Aged↗
PubMed1992

Phosphorylation of specific serine residues within the acidic domain of the phosphoprotein of vesicular stomatitis virus regulates transcription in vitro.

The phosphorylated state of the vesicular stomatitis virus phosphoprotein (P), an essential component of the virion-associated RNA polymerase complex, has been shown to be important for the transcriptional activity of the complex. Recent studies indicate that phosphorylation within the acidic domain of the P protein by cellular casein kinase II is necessary for its activity. In an attempt to identify the exact location of the cell kinase-mediated phosphorylation, we altered specific serine and threonine residues within the acidic domain of the New Jersey serotype of P protein by site-directed mutagenesis. The altered P proteins were then tested to determine what effect these mutations had on the phosphorylated state of the protein in vivo as well as its transcriptional activity in vitro. We report that serine residues 59 and 61 within the acidic domain of the P protein must be phosphorylated for it to be functionally active in a reconstituted transcription assay. These results demonstrate the importance of site-specific phosphorylation in the transcriptional activity of a negative-strand RNA viral phosphoprotein and the crucial role played by a cell protein kinase in this process.

Base Sequence↗
PubMed1992

Role of the phosphoprotein (P) in the encapsidation of presynthesized and de novo synthesized vesicular stomatitis virus RNA by the nucleocapsid protein (N) in vitro.

Encapsidation of presynthesized and nascent (synthesized de novo) vesicular stomatitis virus (VSV) leader RNA in vitro by the nucleocapsid protein (N) and the role of the phosphoprotein (P, previously known as NS) in this process were examined. Presynthesized VSV leader RNAs were derived from the SP6 transcription vectors containing both (+) and (-) leader genes while the nascent RNA was derived from transcription of viral ribonucleoprotein (RNP) complex. The N and the P proteins were made by transcription from SP6 vectors containing the genes, followed by translation of the mRNAs in rabbit reticulocyte lysate. Here, we demonstrate that the N protein alone encapsidated presynthesized VSV leader RNA; however, prior formation of N-P complex totally abolished the encapsidation property of N. On the other hand, encapsidation of nascent RNA by the N protein was stimulated by the N-P complex. These results suggest that encapsidation by the N protein of presynthesized and nascent VSV RNA are separate biochemical processes which can be distinguished by the differential role of the phosphoprotein P in the two reactions.

Capsid↗
PubMed1992

Efficacy of oral fluconazole in Cryptococcus neoformans infection.

We report a renal allograft recipient who developed disseminated cryptococcosis, which was treated effectively, with oral fluconazole, a new triazole antifungal agent. The patient is doing well on maintenance therapy with fluconazole and immunosuppressive agents.

Administration, Oral↗
PubMed1991

Ocular complications in renal allograft recipients.

Ocular complications in renal allograft recipients are a significant cause of morbidity. Of 80 renal transplant recipients, 42 (52.5%) developed ocular complications. These included posterior subcapsular cataract in 22 patients (27.5%), opportunistic ocular infections by CMV, cryptococcus, mucormycosis, herpes simplex and herpes zoster in five (6.25%), steroid-induced raised intraocular pressure in four (5%) and primary disease-related vascular complications in ten (12.5%). Our findings highlight the importance of regular ocular examination of all allograft recipients in the post-transplant period.

Adolescent↗
PubMed1991

Crescentic glomerulonephritis associated with puerperal sepsis.

Acute renal failure developed in a young female having puerperal sepsis due to beta-haemolytic streptococci. The patient succumbed to her illness and an autopsy revealed extensive crescentic glomerulonephritis. The association between chronic visceral sepsis and glomerulonephritis is discussed.

Acute Kidney Injury↗
PubMed1990

Relationship between fatty acid synthesis, transport and total lipid content during human fetal lung development.

Levels of fatty acid binding proteins (FABPs), lipids as well as activities of fatty acid synthesizing enzymes such as fatty acid synthase and ATP-citrate lyase increase with gestation showing maximum at term in human fetal lung. However, the activity of ATP-citrate lyase showed the same trend up to 30 weeks of gestation before declining slightly at term. These results indicate the importance of supply and/or synthesis of fatty acids when lung surfactant synthesis begins; thereby showing a correlation between the FABPs, lipid pattern and the activities of fatty acid synthesizing enzymes during prenatal lung development.

ATP Citrate (pro-S)-Lyase↗
PubMed1989

Human fetal liver fatty acid binding proteins. Role on glucose-6-phosphate dehydrogenase activity.

Fatty acid binding proteins (FABPs) may play an important role in the transport and metabolism of fatty acids during human embryogenesis. Three fractions of FABP, namely, DE-I, DE-II and DE-III, having Mr 14,200 Da each and pI values 7.8, 6.9 and 5.4, respectively, have been detected in human fetal liver. These proteins were purified by heat and butanol precipitation of fetal liver supernatant as well as by gel filtration and ion-exchange chromatography. Fetal liver FABPs are immunochemically identical to each other. Concentrations of DE-I, DE-II and DE-III increase gradually from early gestation to term. DE-I is almost lipid-free, DE-II binds long-chain fatty acids nonspecifically and DE-III transports mainly arachidonic acid. DE-II and DE-III protect glucose-6-phosphate dehydrogenase, which furnishes NADPH for fatty acid synthesis, from the feed-back inhibition exerted by added palmitoyl-CoA and oleate. In the absence of exogenous inhibitors, this enzyme is stimulated by FABPs. DE-I has no effect on such inhibition. Thus, FABPs play a regulatory role in critical aspects of cellular physiology during human embryogenesis.

Carrier Proteins↗
PubMed1989

Purification and characterization of fatty acid-binding proteins from human fetal lung.

Fatty acid-binding protein (FABP) was isolated, purified, and characterized from developing human fetal lung cytosol by gel filtration and ion-exchange chromatography. FABP exists in three immunochemically identical forms, DE-I, DE-II, and DE-III, having Mr 15,200 +/- 200 each and isoelectric pH 7.8, 6.9, and 5.4, respectively. DE-I is almost lipid-free, DE-II binds mainly long-chain unsaturated fatty acids, and DE-III is an arachidonic acid carrier. One mole of DE-II and DE-III each binds 1 mol of fatty acids noncovalently. Concentrations of all these FABPs increase gradually from early gestation to term. Defatted lung FABP reverses the inhibitory effect of palmitoyl coenzyme A (CoA) (PAL-CoA) on lung glucose-6-phosphate dehydrogenase (G6PD), a key enzyme of the hexose monophosphate (HMP) shunt pathway. This protein when added alone activates the enzyme, suggesting that the original submaximal activity is probably due to the presence of endogenous long-chain fatty acyl CoA esters in the cytosols. As FABP is present in relatively high concentration in most mammalian cells, the potent inhibitory effects of long-chain acyl CoA esters on the HMP shunt pathway in vitro are not seen in intact cells.

Carrier Proteins↗
PubMed1988

Purification and characterization of fatty acid-binding protein from human placenta.

Purification of a cytosolic fatty acid-binding protein (FABP) from developing human placenta has been achieved, and its role in modulating the inhibition of human placental glucose-6-phosphate dehydrogenase (G6PD) by palmitoyl-CoA (PAL-CoA) has been studied. FABP was resolved into three peaks, viz. DE-I, DE-II and DE-III, by DEAE cellulose chromatography. DE-I was almost lipid-free. Presence of endogenous fatty acids in DE-II and DE-III was detected by thin layer chromatography (TLC). Fatty acids were the only detectable lipid component in these fractions. Gas liquid chromatography (GLC) analysis revealed that DE-II binds long chain saturated and unsaturated fatty acids nonspecifically, whereas DE-III is mainly an arachidonic acid carrier. Each of these fractions, viz. DE-I, DE-II and DE-III, has a molecular weight of 14,200 Daltons. Ouchterlony double immunodiffusion studies have confirmed the immunochemical identity of these three fractions of placental FABP. Separation in ion exchanger may be due to their different isoelectric points and varied types of binding affinities. Human placental G6PD was inhibited 50% by 0.03 mM PAL-CoA. The DE-II fraction of FABP enhanced the activity of G6PD in the absence of added PAL-CoA and protected against PAL-CoA inhibition of the enzyme. Such a modulating effect of FABP in this inhibition is attributable to binding of long chain acyl-CoA rather than to a direct effect of FABP on the enzyme itself.

Carrier Proteins↗
PubMed1988

Effects of lanthanum in cellular systems. A review.

Lanthanum belongs to the group of elements known as "lanthanons," which also includes cerium, europium, promethium, and thulium. It is the most electropositive element of the rare earth group, is uniformly trivalent, and is similar in its chemical properties to the alkaline earth elements. The effects of this element and its compounds on cellular systems are of considerable interest because of their increasing use in industry and as a substitute or antagonist for calcium in a variety of cellular reactions. Lanthanum is also being employed extensively in studying anatomical barriers, membrane structure, and subcellular transport systems, particularly the calcium pathway.

Animals↗
PubMed1987

Combined photocoagulation and cryotherapy in treatment of Eales' retinopathy. Preliminary report.

This is a preliminary report of Eales' disease study (EDS). Compilation of two years data shows that combined xenon are photocoagulation and peripheral cryotherapy has beneficial effects in treatment of Eales' disease with grade II and grade III retinopathy. In very advanced stage of the disease (grade IV retinopathy) the treatment has no beneficial effects and untreated also it leads to vitreous haemorrhage and traction retinal detachment. The Eales' disease study (EDS) is still an on-going project and recruitment of the patients is continuing. Over another year we hope to have a larger number of patients, accumulate enough data and cover a longer follow-up period to substantiate these preliminary findings.

Adult↗
PubMed1987

Wedge scleral buckling in prevention of fish mouth phenomenon in retinal detachment surgery.

Wedge scleral buckling done in 45 eyes of 43 patients with ballooning detachment and large horseshoe tears where fish-mouth phenomenon was anticipated pre-operatively is analysed. In all of the cases, the retinal break settled on the wedge buckle after drainage of sub-retinal fluid and there was no radial retinal folds over the buckle nor was there fish-mouthing of the tears. The final success rate was 89%. There were no significant operative or post-operative complications and in none of the cases was there extrusion of implant or infection.

Adolescent↗
PubMed1986

Structure and function of the repressor of bacteriophage lambda. III. Molecular cloning of the high-affinity mutant cI gene of lambda and studies of the properties of the clones.

The high-affinity mutant cI gene of lambda cIha (Nag et al. 1984) was cloned in the multicopy plasmid pBR322. In the resulting plasmid, pMD 102, a lacUV5 promoter was inserted giving the lacUV5-cIha fusion plasmid pMD 205. Bacteria carrying pMD 102 and pMD 205 contain 2.5 and 15 times, respectively, the level of repressor in a monolysogen of lambda cIha. Results of the study of certain properties of the bacteria carrying these plasmids suggest that the ha repressor also has a higher affinity for the virulent mutant operators as well as the prm promoter of lambda.

Bacteriophage lambda↗