PubMed Health⌕ Search

Biomedical subjects

T De

Publications and source records attributed to T De.

17 recordsLinked to original sources
PubMed2003

Infectivity and attenuation of Leishmania donovani promastigotes. II: Association of the loss of parasite infectivity with the terminal galactosylation of precursor acceptors present in virulent parasites by the developmentally regulated galactosyltransferase.

The beta1-4 galactosyltransferase enzyme of the Leishmania donovani promastigotes, was found to be developmentally regulated and expressed only in the attenuated parasites. The enzymatic product of soluble determinants of virulent promastigotes and the galactosyltransferase enzyme was found to stimulate the macrophage burst activity but inhibit in vitro intracellular parasitism. In contrast, removal of terminal galactose moieties from soluble determinants of attenuated parasites resulted in the inhibition of macrophage respiratory burst activity but did not now inhibit intracellular parasitism. We propose that the terminal galactosylation of acceptor substrates present in virulent parasites by the developmentally regulated galactosyltransferase is associated with loss of parasite virulence.

Animals↗
PubMed2001

Depression in acutely medically ill elderly inpatients: a pilot study of early identification and intervention by formal psychogeriatric consultation.

BACKGROUND: Depressive disorders are common among acutely medically ill elderly inpatients, but they are poorly recognised and treated. A single blind, randomised and controlled pilot study evaluating the efficacy of early identification of depression and intervention by a psychogeriatric consultation was undertaken. METHOD: A two-stage screening procedure, using the Geriatric Depression Scale (GDS) and the Brief Assessment Schedule (BAS), was used to identify patients with depression. They were randomised into two groups: one received a psychogeriatric consultation and the other acted as a control group. Patients were followed-up at 10 weeks and 1 year interval. RESULTS: There were no differences between the intervention group and the control group on any outcome measure at 10 week and 1 year follow-up. There was poor concordance between recommended interventions and their implementation by the geriatricians in the intervention group. Also, there were no differences between the intervention and control groups in terms of the interventions received by the patient. The whole sample improved on almost all outcome measures from baseline to 10 weeks and 1 year follow-up. CONCLUSIONS: Reasons for the absence of efficacy of psychogeriatric consultation and suggestions for improved methodology are discussed.

Acute Disease↗
PubMed2001

Macrophage heterogeneity, antigen presentation, and membrane fluidity: implications in visceral Leishmaniasis.

Morphological and functional heterogeneity of the splenic macrophage (M phi) population was studied in Leishmania donovani (LD) infected BALB/c mice. On a discontinuous percoll gradient two distinct M phi populations were separated. They differed significantly in size as evident from Scanning Electron Microscopy (SEM). Morphologically, the bigger M phi (LM) showed surface projections, whereas the smaller M phi (SM) was round. As regards the antigen-presenting abilities, the LM of infected animals showed defective antigen-presenting abilities at a later stage of the disease, i.e. 6 months post infection ((6)I-LM) but not earlier, whereas the SM population remained functionally intact throughout the course of the infection. Further, the (6)I-LM showed a much enhanced Ad status as compared to their controls. Interestingly, both the (6)I-LM and the control set showed a comparable level of binding of a known A(d) restricted peptide. Despite the presence of sufficient A(d) molecules and the ability to bind the appropriate peptide, (6)I-LM were unable to stimulate peptide specific T-cell hybridoma. Further, the (6)I-LM showed an increase in membrane fluidity and distorted morphology with membrane fissure and blebs as evident from SEM. It is possible that an increase in the membrane fluidity may lead to the defective antigen-presenting ability of (6)I-LM. Thus, the LD infection functionally keep the (6)I-LM out of antigen presentation and this may contribute to the defective cell mediated immune response in leishmaniasis.

Amino Acid Sequence↗
PubMed2000

Use of an attenuated leishmanial parasite as an immunoprophylactic and immunotherapeutic agent against murine visceral leishmaniasis.

The ability of the leishmanial parasite UR6 to act as an immunoprophylactic and immunotherapeutic agent against Leishmania donovani infection in BALB/c mice was investigated. Unlike the virulent L. donovani AG83 (MOHOM/IN/1983/AG83), UR6 given through intracardiac route failed to induce visceral infection, but when it was injected subcutaneously, UR6 induced a short-lived and localized self-healing skin lesion. Priming of peritoneal macrophages with UR6 in vitro induced superoxide (O(2)(-)) generation, whereas similar experiments with virulent AG83 inhibited O(2)(-) generation. It was observed that priming of mice with either live or sonicated UR6 in the absence of any adjuvant provided strong protection against subsequent virulent challenge. Further, UR6-primed infected mice not only displayed a strong antileishmanial delayed-type hypersensitivity (DTH) response but also showed an elevated level of the serum antileishmanial immunoglobulin G2a (IgG2a) isotype, whereas infected mice failed to mount any antileishmanial DTH response and showed an elevated level of IgG1. This indicates that UR6 priming and subsequent L. donovani infection allowed the expansion of Th1 cells. Our studies indicate that UR6 has potential to be used as an immunoprophylactic and immunotherapeutic agent against experimental visceral leishmaniasis.

Animals↗
PubMed1999

Infectivity and attenuation of Leishmania donovani promastigotes: association of galactosyl transferase with loss of parasite virulence.

During the course of long-term in vitro cultivation of Leishmania donovani parasites, the promastigotes were found to lose their infectivity. Lectin agglutination studies revealed that there is an up-regulation of terminally exposed galactose residues on the noninfective promastigotes. The enzyme galactosyl transferase was absent in the infective form but present in the non-infective form of the parasites. An association between galactosylation and loss of infectivity was also observed. We propose that the enzyme galactosyl transferase is developmentally regulated and induces galactosylation of surface carbohydrates.

Agglutination↗
PubMed1998

Documented evidence of depression in medical and nursing case-notes and its implications in acutely ill geriatric inpatients.

Depression is common among acutely ill elderly medical inpatients. Identification of such depression by geriatric medicine staff would allow early treatment. The impact of a depression screening procedure on documentation of depressive signs and symptoms in the medical and nursing case-notes was examined. Thirty-five sets of medical and nursing case-notes of medically ill elderly inpatients, for whom data from the Brief Assessment Schedule and the short Geriatric Depression Scale (GDS) were also available, were examined for documentation of signs and symptoms of depression, prescription of antidepressants, and referral to the psychogeriatric service. Depressive signs and symptoms were documented in only a few medical (29%) and nursing (11%) case-notes. Only a small number of depressed patients were prescribed antidepressants (20%) or were referred to the psychogeriatric service (13%). The frequency of documentation of depressive signs and symptoms after the screening procedure with the short GDS was associated with subsequent prescription of antidepressants and referral to the psychogeriatric service. The screening procedure itself may increase the general awareness of depressive signs and symptoms and effect its management. These results require replication.

Aged↗
PubMed1998

The effect of an educational intervention package about aggressive behaviour directed at the nursing staff on a continuing care psychogeriatric ward.

INTRODUCTION: Levels of aggressive behaviour on continuing care wards are high. Various staffing factors, potentially amenable to improvement by training, are important in reducing and preventing aggressive behaviour. METHOD: The efficacy of an educational package, directed at the nursing staff, in reducing aggressive behaviour on a psychogeriatric continuing care ward was prospectively evaluated over an 18-week period. The package was administered during the middle 6-week period. Aggressive behaviour was measured using the RAGE and SOAS scales. RESULTS: Aggressive behaviour on both these scales was reduced after the educational package, and the educational intervention package may explain this reduction. CONCLUSIONS: The educational package may have genuinely reduced aggressive behaviour or improved the nursing staffs tolerance and reporting threshold for aggressive behaviour. Studies with improved methodology in several different settings are suggested.

Adult↗
PubMed1997

The relationship between two scales measuring aggressive behavior among continuing-care psychogeriatric inpatients.

Aggressive behavior among the elderly is a neglected area of research. An 18-week prospective study of aggressive behavior on a continuing-care psychogeriatric ward provided data to examine the relationship between two aggression scales (SOAS and RAGE). There was a strong and significant correlation between the SOAS and RAGE scales for the total and the subscale scores. Both these scales appear useful in measuring aggressive behavior among continuing-care psychogeriatric inpatients. Also, the nursing staff can be trained to complete these scales effectively.

Aged↗
PubMed1987

Glycolipids.

Explore the source record for details and available documents.

Animals↗
PubMed1986

Purification and kinetic studies of an alpha-L-fucosidase of Venus mercenaria.

An alpha-L-fucosidase activity has been isolated from the liver (hepatopancreas) of the common edible clam, Venus mercenaria, and has been purified approximately 300-fold (11% yield) by affinity chromatography on agarose-epsilon-amino-caproylfucosamine. Isoelectric focusing profiles were heterogeneous, revealing several isoenzymes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated the presence of a single subunit of Mr 50,000. The purified enzyme preparation contained only trace amounts of other alpha- and beta-D-glycosidases tested. In addition to p-nitrophenyl alpha-L-fucopyranoside, the enzyme hydrolyzed natural substrates such as fucose-containing milk pentasaccharides, thyroglobulin glycopeptides, human salivary glycoproteins, and blood-group-active glycosphingolipids. The enzyme preparation had a broad pH optimum range between 4.5 and 5.5. The apparent Km value with respect to p-nitrophenyl alpha-L-fucopyranoside was 0.26mM.

Animals↗