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Biomedical subjects

S Pal

Publications and source records attributed to S Pal.

At least 109 records · Page 6Linked to original sources
PubMed1997

Monoclonal immunoglobulin A antibody to the major outer membrane protein of the Chlamydia trachomatis mouse pneumonitis biovar protects mice against a chlamydial genital challenge.

In order to analyze the protective role that IgA may play in a chlamydial infection two IgA monoclonal antibodies (mAb), MoPn 4-2 and MoPn 13-2, were raised against the major outer membrane protein (MOMP) of the Chlamydia trachomatis mouse pneumonitis (MoPn) biovar. mAb MoPn 4-2 was found to be serovar specific while mAb MoPn 13-2 was species specific. mAb MoPn 4-2 recognized a surface exposed conformational epitope as shown by its ability to bind to native EBs and nonreduced MOMP while failing to bind to heat and trypsin treated EBs, to reduced MOMP and to synthetic MOMP peptides. In contrast, mAb MoPn 13-2 recognized a nonconformational epitope since it was able to bind treated EBs, to reduced MOMP and to the synthetic peptide MTTWNPTISGSGI located in variable domain 4 of the MOMP. Both mAbs agglutinated intact EBs and had in vitro neutralizing activity. However, mAb MoPn 4-2 had a 20-fold higher in vitro neutralizing ability when compared to mAb MoPn 13-2 (50% neutralization at 5 micrograms ml-1 vs 100 micrograms ml-1). In an in vitro in vivo infectivity assay, mAb MoPn 4-2 protected mice against infertility when C. trachomatis MoPn elementary bodies were preincubated with the mAb before inoculation. In addition, passive transfer of mAb MoPn 4-2 resulted in significant protection as measured by a decrease in the number of mice infected, and in the intensity and duration of vaginal shedding. These results support previous findings suggesting that IgA antibodies can play a role in protection against a chlamydial infection, and further encourage work to develop vaccination strategies that elicit mucosal immunity.

Alveolitis, Extrinsic Allergic↗
PubMed1997

Immunization with an acellular vaccine consisting of the outer membrane complex of Chlamydia trachomatis induces protection against a genital challenge.

The ability to induce protection against a genital challenge was studied in BALB/c female mice with three Chlamydia trachomatis mouse pneumonitis (MoPn) major outer membrane protein (MOMP) preparations as well as an acellular vaccine consisting of the chlamydial outer membrane complex (COMC). The MOMP preparations were extracted with three different types of detergents, sodium dodecyl sulfate (SDS), n-octyl-beta-D-glucopyranoside (OGP), and Zwittergent 3-14 (Z3-14). A positive immunization control consisted of mice inoculated intranasally with 10(4) C. trachomatis MoPn inclusion-forming units (IFU). Mice inoculated with ovalbumin served as a negative control. Furthermore, a sham-immunized, nonchallenged group was included as a fertility control. Two weeks after the last immunization, the mice were challenged in the left ovarian bursa with 10(5) C. trachomatis MoPn IFU. Vaginal swabs were collected for culture, vaginal and serum samples were assayed for chlamydial-specific antibodies, and splenocytes were collected to determine the lymphoproliferative response. At 42 days after the challenge, the mice were mated with proven male breeder mice. Animals that were considered to be pregnant (as determined by weight) were killed, and the embryos were counted. A significant humoral and cell-mediated immune response was observed in all the groups of mice inoculated with chlamydial antigens. Antibodies to variable domain (VD)1 of the MOMP were detected in serum samples from all the immunized groups. However, antibodies to VD3 and VD4 were detected only in the groups immunized with the Z3-14-MOMP and the COMC. Mice immunized with COMC developed significant immunoglobulin A chlamydia-specific antibodies in the vagina, while mice immunized with the detergent-extracted MOMPs had low antibody titers. Following the intrabursal challenge, a significant decrease in the intensity and duration of vaginal shedding was noted in the mice immunized with COMC and a moderate decrease was noted in the group immunized with OGP-MOMP. No protection against the infection was noted in the groups of animals immunized with SDS- and Z3-14-MOMP. Furthermore, of the mice immunized with the COMC preparation, only 25% (4 of 20) shed C. trachomatis, as determined by vaginal culture, while 83% (40 of 48) of the control mice inoculated with ovalbumin were culture positive (P < 0.05). In addition, after mating, the mice inoculated with COMC were found to have fertility rates comparable to those of the control sham-immunized, nonchallenged animals (70% [14 of 20] versus 81% [17 of 21], respectively [P > 0.05]), and there were no significant differences between the average number of embryos per mouse in the two groups (5.1 versus 5.9, respectively [P > 0.05]). In contrast, mice immunized with the purified MOMP preparations were not protected against infertility. In summary, a preparation of the COMC protected mice against infection and infertility, supporting the feasibility of the development of an acellular vaccine against C. trachomatis infections.

Animals↗
PubMed1997

Mental disorders in abnormal offenders in Papua New Guinea.

The case notes of all 64 referred abnormal offenders (mental patients with criminal records) sent to a psychiatric hospital between January 1971 to May 1996 were examined. It was found that severe mental disorder like schizophrenia (27 out of 64) was the most common cause of violent crimes such as homicide. Epilepsy 10.9 (n = 7) was another important neuropsychiatric condition related to violence. Alcohol and cannabis abuse were an associated factor in 21 (32.8%) referred cases. Culture bound syndromes like "Amok Syndrome" and "Spirit Possession Syndrome" were also found as a cause of violent behavior.

Adolescent↗
PubMed1997

Pt-ATP as an antineoplastic agent in an experimental mice model system.

The antineoplastic activity of a platinum complex K4 (Pt Cl2 ATP) (Pt-ATP) has been investigated in transplantable tumors, both in an ascitic and solid (Ehrlich ascites carcinoma) tumor model. It has been observed that the drug at the total dose of 10 mg/kg body weight successfully inhibited the tumor burden both in ascitic and solid tumor system and subsequently increased the host's life span. An assessment of the in vitro (3H) thymidine incorporation into TCA precipitable material of EAC tumor cells done in the presence of Pt-ATP indicates that the drug inhibits (3H) thymidine incorporation in tumor cells. The drug has no appreciable toxic effect on the peripheral blood cells as well as bone marrow and spleenic cellularity.

Adenosine Triphosphate↗
PubMed1997

Animal experimentation with tooth derived calcium hydroxyapatite based composites as bone-graft substitute biomaterials.

Calcium Hydroxyapatite (HA) has now been clinically accepted as one of the most important alloplastic bonegraft substitute in the management of oral surgical procedures including periodontal bony defects. HA can be synthetically prepared or derived from natural sources. Among the natural sources bovine bone is common but human source is also used. Of late Calcium Hydroxyapatite has been derived from extracted human tooth source. The present study involves the experiments using different varieties of HA in conjunction with chitosan, a binder, to know it's unique biological behaviour of bone bonding. The experiment was designed using 12(Twelve) New Zealand white rabbits on transcortical drilled hole tibial model and the observation was made under optical and scanning electron microscope. Result showed the osteoconductive and bioactive nature of tooth derived HA and biocompatibility of chitosan. The clinical problem of handling the particulate form of HA can be overcome by using chitosan which when mix with HA can stabilize the particle in surgical sites. This has tremendous clinical applications in dental regenerative surgery.

Animals↗
PubMed1996

Expression of a unique globo-series glycolipid in cultured rat dorsal root ganglion neurons: relationship with neuronal development.

Previous studied from the laboratory demonstrated the presence of a UDP-galactose:Gb3Cer alpha 1-3galactosyltansferase activity responsible for the synthesis of a unique glycosphingolipid (GSL), Gal alpha 1-3Gb3Cer, in cultured PC12 pheochromocytoma cells (21). In this investigation, we examined the presence of this enzyme activity in isolated rat embryonic dorsal root ganglion neurons (DRGN), which, like pheochromocytoma cells, originate from the neural crest cells. DRGN exhibited the alpha-galactosyltransferase activity and the activity was comparable to that of the PC12 cells while several other rat tissues, with the exception of kidney, showed minimal activity. In order to define the spatial and temporal expression of Gal alpha 1-3Gb3Cer in DRGN, we examined the expression of Gal alpha 1-3Gb3Cer in cultured DRGN derived from embryonic day 16 rat embryos. Using a polyclonal antibody raised against Gal alpha 1-3Gb3Cer, we examined the localization of this glycolipid in DRGN cells after 5, 8, 12, and 15 days in culture. Immunostaining was restricted to the neurons while Schwann cells were negative. At day 5, the immunostaining was weak and confined to the cell body of the DRGN, though neurites were present at this stage. The period between days 5 and 15 represented a period of rapid neuritic growth and continued enlargement of the cell bodies. Immunoreactivity in the cell bodies increased dramatically by day 8. By day 12, immunoreactivity was present in neurites, and by day 15, was strong in both cells bodies and neurites. The expression of Gal alpha 1-3Gb3Cer in vivo was confirmed by immunostaining of frozen sections of dorsal root ganglia. Our present studies which demonstrate neuron-specific expression of Gal alpha 1-3Gb3Cer during neurotigenesis combined with previous observations for its expression in PC12 cells, strongly implicates this GSL in neuronal development.

Animals↗
PubMed1996

Electrophoretic mobility and immune response of outer membrane proteins of Vibrio cholerae O139.

The outer membrane (OM) protein components of a Vibrio cholerae O1 and four V. cholerae O139 strains, collected from cholera patients, were analysed by SDS-PAGE. A protein of 69 kDa molecular mass was observed only when the OMPs were prepared from strains grown in synthetic broth. As a result of passage in the rabbit ileal loop (RIL), virulence was enhanced, and a protein component around 18 kDa of the V. cholerae O139 OM became the major protein component. On immunoblot analysis with rabbit antiserum against V. cholerae O139 OM, it was shown that, apart from the major protein component of V. cholerae O1 OM of around 45 kDa and that of V. cholerae O139 OM of around 38 kDa, all other minor protein components were cross-reactive between the two serogroups. In immunoblot assays with convalescent sera obtained from V. cholerae O139-infected patients, it was observed that in addition to the lipopolysaccharide (LPS)-induced antibody, only the 38 kDa major protein component elicited considerable levels of antibody in the patient. Minor OM components of 18 kDa were detected in the immunoblot analysis by LPS-directed antibody, however, as the OM proteins are known to be associated with LPS.

Animals↗
PubMed1996

Intranasal immunization induces long-term protection in mice against a Chlamydia trachomatis genital challenge.

In an attempt to confer long-term protective immunity, BALB/c female mice were immunized intranasally with 10(4) inclusion-forming units (IFU) of the Chlamydia trachomatis mouse pneumonitis biovar (MoPn). Animals were subsequently challenged in the ovarian bursa with 10(5) C. trachomatis MoPn IFU at 60, 120, or 180 days post-intranasal immunization. Two control groups were included in the study. One control was sham immunized and mock challenged, and another group was sham immunized and challenged with 10(5) C. trachomatis MoPn IFU. Vaginal cultures were collected at regular intervals following the intrabursal challenge. In comparison with the sham-immunized mice, the animals that were intranasally immunized with C. trachomatis had significant protection, as shown by a reduction in the number of animals that had positive vaginal cultures and by a decrease in the intensity and length of the shedding. Furthermore, histopathological characterization of the genital tract following challenge, in the three groups of mice, showed a minimal inflammatory infiltrate in the C. trachomatis-immunized animals, when compared with the sham-immunized control group. Subsequently, the three groups of female mice that were challenged at 60, 120 and 180 days postimmunization were mated at 6 weeks following the challenge. Overall, in the mice intranasally immunized with C. trachomatis the fertility rates and the number of embryos were similar to those in the sham-immunized and mock-challenged group. In contrast, there was a significant increase in infertility in the groups of mice that were sham immunized and C. trachomatis challenged. In conclusion, intranasal immunization with C. trachomatis induces long-term protection against a genital challenge as shown by a decrease in the infection and infertility rates when compared with sham-immunized animals. Thus, this model may help to characterize the parameters of the immune response that are important in maintaining long-term protection and may aid in identifying the antigenic determinants involved in eliciting protection.

Administration, Intranasal↗
PubMed1996

Compliance with recommended follow-up after fine-needle aspiration biopsy of nonpalpable breast lesions: a retrospective study.

PURPOSE: To determine compliance with recommendations for mammographic or surgical follow-up after fine-needle aspiration biopsy of non-palpable breast lesions. MATERIALS AND METHODS: The authors reviewed the medical records of 419 patients in whom surgical or mammographic follow-up had been recommended after fine-needle aspiration biopsy. Mammographic, clinical, and follow-up findings were correlated with patient outcome. Of 466 lesions, 395 lesions in 359 patients (age range, 24-89 years; average age, 55 years) were nonpalpable and composed the study. RESULTS: Excisional biopsy was recommended in 141 cases (35.7%) and close-interval mammographic surveillance in 165 (41.8%). Biopsy was performed in 122 (86.5%) of the 141 cases in which it was recommended. Of 165 cases in which follow-up mammography was recommended, 84 (50.9%) were resolved at the close of the study. In the remaining cases, women either did not return (n = 24), were followed up elsewhere or moved (n = 35), were lost to follow-up by their physicians (n = 17), or were lost to follow-up for other reasons (n = 5). CONCLUSION: Noncompliance with follow-up recommendations is an important issue undermining the benefits of fine-needle aspiration biopsy. Difficulty in tracking patients hinders assessment of patient compliance.

Biopsy, Needle↗
PubMed1996

Predictors of survival in HIV-infected patients on hemodialysis.

We undertook the present study to determine whether there might be variables other than CD4 counts which might help predict survival of HIV-infected patients who are placed on chronic hemodialysis, survival which often is extremely poor. We studied prospectively (n = 18) and retrospectively (n = 6) 24 consecutive HIV-positive patients on chronic hemodialysis at our institution over a 7-year period and recorded clinical and laboratory variables at the time of initiation of dialysis. The mean survival for the group as a whole was 11 +/- 8 (range 2-32) months. A highly significant positive correlation was found between survival and CD4 counts (p < 0.001) and blood pressure (systolic, p < 0.02; diastolic, p < 0.05; mean arterial, p < 0.05). Infection rate and urine protein excretion both had significant negative correlations with survival (p < 0.01 and p < 0.02, respectively). The presence of edema appeared to have a positive effect on survival (p < 0.01). The use of antiretroviral therapy resulted in significantly greater survival of HIV-infected patients (15.2 +/- 2.2 vs. 6.2 +/- 1.2 months, p < 0.01). Using a general linear model, it was found that CD4 count and systolic, diastolic, and mean arterial blood pressures and infection rate all were independent estimators of survival. We conclude that variables other than CD4 counts might also be useful in predicting survival in HIV-infected patients on chronic hemodialysis.

AIDS-Associated Nephropathy↗
PubMed1996

Comparative evaluation of somatic & excretory-secretory antigens of Entamoeba histolytica in serodiagnosis of human amoebiasis by ELISA.

The excretory-secretory antigens collected from the axenic culture medium and conventional somatic antigen prepared from the whole trophozoites of E. histolytica were compared for their efficacy in serodiagnosis of amoebiasis. A total of 280 sera collected from different clinically proven cases of amoebiasis and healthy subjects were analysed against both the antigens in ELISA. Both antigens showed a 100 per cent correlation in amoebic liver abscess cases, patients infected with enteropathogens other than amoeba and healthy subjects. However, excretory-secretory antigens showed slightly higher detection rate in patients suffering from acute amoebic dysentery and asymptomatic cyst passers groups. These results clearly suggested the use of excretory-secretory antigens by ELISA for serodiagnosis of amoebiasis due to its better or equal sensitivity, specificity and easier preparation compare to conventional antigen. The use of excretory-secretory antigen in serodiagnosis will not only help in performing more tests utilizing the same chemicals, but also save the cost, time and troubles for importing the foreign chemicals required for cultivation of E. histolytica.

Animals↗
PubMed1996

An in vitro qualitative assay for the detection of antibodies to HIV type 1/2 contained in human saliva.

There is ample evidence that saliva contains secretory antibody against most infections. Therefore, saliva has been recommended as a non invasive, safe and effective alternative to serum, for HIV antibody testing. The present study attempted comparative evaluation of antibody detection by serum and saliva specimens in laboratory by ELISA and Western Blot for diagnosis of HIV infection in the Indian situation. From a study of 42 test sera it is concluded that test apart from its simplicity and reproducibility, is almost free from any false positive and false negative reactions.

Blotting, Western↗
PubMed1996

Anorexia nervosa.

Explore the source record for details and available documents.

Adolescent↗
PubMed1995

Purification and characterization of a new 85-kDa glycoprotein antigen from human breast tumor.

A new breast-tumor-associated antigen (BTAA) was purified and partially characterized from human breast tumor. By DEAE-cellulose discontinuous NaCl-gradient chromatography of a crude extract of human malignant breast tumor, 3 major protein peaks were obtained. Circulating antibodies against one of the protein peaks, HF1, was observed in breast-cancer patients. The antibodies were absent in patients with carcinoma of the uterine cervix, lung, stomach and liver or with benign breast diseases and in healthy women. Absorption of the sera of breast-cancer patients with normal human breast tissue pellet did not remove the HF1-reactive circulating antibodies. The BTAA was partially purified from HF1 by subjecting the fraction to SDS-PAGE and eluting the band 3 (HF1-3). Western-blot analysis confirmed the presence of the BTAA in HF1-3. Using an affinity column of protein-A-Sepharose-bound IgG, purified from breast-cancer patients' sera, the BTAA was also recovered from HF1. Purification of the BTAA was achieved by subjecting HF1 to size-exclusion high-performance liquid chromatography (SE-HPLC). The antigen was characterized as a glycoprotein with MW of approximately 85 kDa and appeared not to be related either to murine mammary-tumor virus (MuMTV) structural antigens or to human fetal antigens. The BTAA-reactive circulating antibodies in the breast-cancer patients were of IgG, sub-type, and the level of these antibodies significantly decreased in patients following surgical removal of the breast tumors.

Antigens, Neoplasm↗