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Biomedical subjects

R Ganguly

Publications and source records attributed to R Ganguly.

At least 55 records · Page 3Linked to original sources
PubMed1985

Macrophage functions in aging: effects of vitamin C deficiency.

Groups of young adult and senescent guinea pigs were fed normal and vitamin C deficient diets for 4 weeks and tested for their peritoneal macrophage functions. Serum levels of vitamin C in deficient animals indicated a progressive state of ascorbic acid deficiency and correlated well with the clinical signs and symptoms of scurvy. Fewer macrophages were obtained from the peritoneal cavities of deficient animals and morphologically they were smaller in size. Adverse effects of vitamin C deficiency were enhanced in aged animals. Significantly greater number of aged animals died by 4 weeks of deficiency. Deficient senescent animals had greater decline in macrophage random migration and bactericidal capacity. Following phagocytic stimuli, superoxide anion generation also significantly decreased. Data suggest that vitamin C deficiency might affect macrophage functions in the aged more profoundly and could compromise parameters of host defenses effective against microbial infections.

Aging↗
PubMed1984

Inhibition of yeast phagocytosis in macrophage cultures treated with slime polysaccharide purified from Pseudomonas aeruginosa.

This study was initiated to determine whether purified slime polysaccharide(PSP) from P aeruginosa inhibits the ingestion of heat killed Saccharomyces cerevisiae particles in macrophage cultures. Relative to controls, direct phagocytosis assays revealed that the percentages of phagocytes and the numbers of ingested yeast particles per phagocyte decreased in a dose-dependent manner in PSP-treated cultures. Thus, PSP may act as a virulence factor in vivo by impairing the phagocytic capacity of macrophages.

Animals↗
PubMed1984

Vesical gigantism or congenital megacystis.

We report on a child who was born with a large unobstructed bladder with normal trigone and normal ureteral insertions. The differences between vesical gigantism and the congenital megacystis-megaureter syndrome are discussed. In our patient, reduction cystoplasty was efficacious in alleviating the child's symptoms and recurrent urinary tract infections. More cases would be of benefit in confirming the usefulness of this procedure.

Diagnosis, Differential↗
PubMed1984

Immunization against viral infections. Successful, ongoing mode of defense.

The body protects itself from disease through a variety of innate defense mechanisms and through immunity acquired both passively and actively. Passive immunization is achieved through transfer of antibody or of sensitized lymphocytes or their soluble products from an immune donor, while active immunization is achieved through stimulation of the recipient's own protective mechanism by means of exposure to the disease or to pathogens or their toxoids. Among the diseases brought under control or eradicated by means of active immunization are smallpox, polio, and measles. Vaccines for immunization against several other diseases are already being used successfully and further ones are being developed.

Antibody Formation↗
PubMed1984

Microbicidal activity and superoxide production by macrophages in aging rats.

This study examined the effects of aging on the immunobiological properties of alveolar macrophages in young adult and aged rats. Macrophages, obtained by lung lavage, were enumerated and tested in vitro for yeast phagocytosis and fungicidal activities. Superoxide anion (O2-) generation stimulated by opsonized zymosan was compared between the two groups. Total numbers of alveolar cells and the differential cell distribution were comparable in both the groups. The difference between the groups was not statistically significant, even though the yeast phagocytic capacity in the cells from senescent animals was consistently higher than in the controls. This may be due to the wide degree of variability observed in the aged animals. However, cell fungicidal activity was statistically lower in the aged animals at 90 minutes of incubation which correlated with a significant decline in the O2- production. Aging may adversely affect some of the immunobiologic functions of lung macrophages and thus compromise host defense mechanisms in the respiratory tract.

Aging↗
PubMed1984

Inhibition of protein synthesis and lymphokine production by tetracycline.

This study was designed to examine the effects of tetracycline on DNA and protein synthesis by human lymphocytes treated with Con A. The effects of the drug were also assessed in terms of the in vitro production of the lymphokine, migration inhibitory factor (MIF). The results indicate that marked suppression of protein synthesis occurred in presence of tetracycline at all concentrations including clinically achievable doses. The group mean values of DNA synthesis did not show significant inhibition with lower concentrations of the drug. The marked decline in protein synthesis in tetracycline treated cultures was accompanied by a significant suppression of MIF production. Accelerated migration of macrophages was observed when the lymphocyte supernatant was produced in presence of the higher concentrations of tetracycline (75-100 microliter/ml). These observations suggest that tetracycline interfered with the in vitro correlates of cellular immunity in humans. This raises a possibility that indiscriminate use of the drug might compromise host defenses especially where long-term therapy is prescribed.

Concanavalin A↗
PubMed1984

Respiratory tract immunity in the aged.

In the elderly, respiratory infections are frequent and constitute the leading cause of death. Presumably this is the consequence of reduced local immunity in the respiratory tract. The present knowledge based on investigations in man and laboratory animals, including results of own research, is reviewed. Further research is needed to give a definite answer and to improve immunoprophylaxis in the elderly.

Age Factors↗
PubMed1983

T- and B-cell memory on mucosal surfaces.

The secretory immune system exhibits memory responses in both B- and T-cell systems. Booster immunization mediates rapid activation of immune lymphocytes that may be important for host protection. Local memory responses may be generated following application of the antigen systemically or at other distant mucosal sites. The dichotomy between the systemic and local immune systems could be overcome, at least partially, in memory responses, depending upon the route and amount of antigen employed for the booster immunization.

Animals↗
PubMed1983

Suppression of the production of migration inhibitory factor in humans by tetracycline.

The role of Tc in the suppression of immunity has not been widely evaluated although this antibiotic is often prescribed as a long-term therapy [1]. Sporadic reports have indicated that Tc suppresses cellular immunity [2]. However, no data are available concerning the effects of Tc on lymphokine production, especially in human subjects. Peripheral blood mononuclear cells (2 X 10(6)/ml) were obtained from seven normal volunteers and pulsed with 150 micrograms of con A/ml of medium for 3 hr at 37 C. The procedure was carried out in the presence or absence of Tc in RPMI medium under an atmosphere of 5% CO2. The cells were then pelleted, washed, and resuspended in RPMI medium with or without similar concentrations of Tc. Following incubation for 48 hr, the cells were removed and the supernatant was assayed for MIF activities with the use of guinea pig peritoneal macrophages as indicator cells. A change of greater than or equal to 20% in migration was considered significant [3]. Remarkable inhibition of MIF production was noted in cells obtained from five of seven volunteers in the presence of 3 micrograms and 100 micrograms of Tc/ml. ConA-induced inhibition of migration was almost abolished in cell cultures in the presence of 3 micrograms of Tc/ml. Negative inhibition (accelerated migration) was observed in the presence of 100 micrograms of Tc/ml. Macrophage migration in the presence of 100 micrograms of Tc/ml was greater than the migration of control cells. Thus, it appeared that Tc not only interfered with MIF production but also modulated factors involved in the control of normal cell migration.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Proteins↗
PubMed1983

Depressed macrophage functions at temperatures below 37 degrees C.

Immunobiological properties of guinea pig and human peritoneal macrophages were studied at temperatures ranging from 25 degrees C to 37 degrees C. Glass adherence, random migration, response to MIF and killing of Salmonella typhimurium and Saccharomyces cerevesiae by guinea pig macrophages were decreased with temperatures below 37 degrees C. Killing of Sacch. cerevesiae by human macrophages was also reduced at temperatures less than 37 degrees C. Acid phosphatase and beta-N-acetylglucosaminidase (NAG) activity assayed at 37 degrees C did not change when the cells were preincubated for 1 and 5 hours at various temperatures. Impaired macrophage function with subnormal temperatures may contribute to enhanced susceptibility to infection of patients with chronic diseases such as renal failure and cirrhosis.

Acetylglucosaminidase↗
PubMed1982

Growth and differentiation of hyperplastic outgrowths derived from mouse mammary epithelial cells transformed in organ culture.

Potentially neoplastic outgrowths of BALB/c mouse mammary hyperplasia(s) (MH) derived from 7,12-dimethylbenz[a]anthracene-transformed epithelial cells in organ culture were characterized for responses to the hormones normally required for morphogenesis and functional differentiation of the mammary tissue. In a new culture model of the gland-free mammary fat pad, DNA synthesis in the MH outgrowths increased to a single peak during 6 days of incubation in a serum-free medium containing insulin, prolactin, aldosterone, and cortisol. The rise in DNA synthesis was accompanied by increased cell number and lobuloalveolar morphogenesis filling 50-70% of the fat pad; the rate of growth was variable among the MH outgrowth lines. Certain MH tissue showed some growth response in medium with aldosterone, cortisol, or estrogen, and progesterone in the presence of insulin. The hormone mixture insulin-prolactin was conducive to maximal growth, which suggested an altered sensitivity of the MH outgrowths to the mammogenic steroid hormones. Functional differentiation in the MH outgrowths was assessed in vivo by determination of the casein messenger RNA (mRNAcsn) levels measured by a specific complementary DNA probe. In MH-1 and MH-5 outgrowth lines, mRNAcsn was measurable in lactating hosts. In MH-9 outgrowth essentially the same concentration of mRNAcsn was present both in virgin and lactating hosts. Although mRNAcsn was present in MH outgrowths in lactating hosts, the concentration of the mRNA was only 0.056-0.88% of that present in the lactating host's own mammary gland. Virtually no mRNAcsn was measurable in the mammary tumors, regardless of the endocrine environment of the host animal. The results indicate a transformation-associated altered pattern of mammary cell-specific gene expression.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1982

Microbicidal capacity and acid hydrolase content of human blood monocytes and peritoneal macrophages.

Peritoneal macrophages and peripheral blood monocytes were collected from healthy women undergoing laparoscopic tubal clipping. Monolayers of adherent cells were examined for protein content, intracellular levels of lysosomal enzymes, and antimicrobial capacity. Compared to blood monocytes, peritoneal macrophages were larger and less glass-adherent and were less capable of intracellular killing of Salmonella typhimurium. Acid hydrolase content, however, was increased in peritoneal macrophages. These data suggest that resting human tissue macrophages may be less active in certain respects than their blood precursors. One should then question whether the enhanced functions observed after long-term in vitro culture of blood monocytes-macrophages accurately reflect the in vivo status of their more differentiated descendants.

Female↗
PubMed1981

Simultaneous occurrence of pregnancylike lobuloalveolar morphogenesis and casein-gene expression in a culture of the whole mammary gland.

Entire second thoracic mammary glands of estrogen- and progesterone-treated immature virgin BALB/c mice were stimulated to pregnancylike lobuloalveolar morphogenesis after 6 days of incubation with insulin (5 micrograms/ml), aldosterone (1 micrograms/ml), growth hormone (5 micrograms/ml), cortisol (5 micrograms/ml), and prolactin (80 ng/ml, present as a contaminant in 5 micrograms/ml growth hormone). The alveolar growth in the glands, as judged by morphological studies, was accompanied by an increase in cell number as a function of incubation time in the hormonal medium. Hybridization of the total RNA from these glands to the casein mRNA specific complementary DNA probe (cDNAcsn) revealed that the level of casein mRNA rises from 0.00012 to 0.005% between 1 and 6 days of incubation. Estimates showed that the concentration of casein mRNA per cell rises 17-fold from 70 molecules on Day 1 to 1200 molecules on Day 6, whereas the number of epithelial cells increases only twofold during the same incubation time. When the growth hormone preparation was totally replaced by 80 ng of prolactin during the 6-day incubation, casein-mRNA levels were found to be 0.0083%. These results demonstrate that a pregnancy-like morphogenesis and concurrent expression of the casein gene in vitro can be achieved in a controlled hormone environment containing high cortisol and low prolactin concentrations. This one-step mammogenesis-lactogenesis culture model should be useful for studying the mechanisms of hormonal regulation of casein-gene expression observed in prepartum mammary gland in vivo.

Aldosterone↗
PubMed1980

Absolute requirement of glucocorticoid for expression of the casein gene in the presence of prolactin.

Second thoracic mammary glands of immature BALB/c female mice were stimulated to pregnancy-like lobuloalveolar (LA) development aftr 6 days of incubation in a corticosteroid-free step I culture medium containing insulin, prolactin, estradiol, progesterone, and growth hormone. A low basal level (0.0009%) of casein mRNA (mRNAcsn) sequences was detectable in the LA glands by a specific cDNA probe. Subsequent incubation of the LA glands for 3 days in medium containing insulin and prolactin or insulin and cortisol failed to elicit mRNAcsn above the basal level, indicating that neither prolactin nor cortisol alone can support casein gene expression. However, an increase in mRNAcsn levels was observed when the 3-day incubation with insulin and cortisol or insulin and prolactin was followed by 3 days of culture in presence of insulin, prolactin, and cortisol. When a 3-day incubation with insulin and prolactin was followed by 3 days in insulin and cortisol medium, mRNAcsn levels in the gland remained similar to the basal level. However, a 20-fold increase in the mRNAcsn levels ensued when the LA glands were sequentially incubated for 3 days in insulin and cortisol and then for another 3 days in insulin and prolactin medium. After a preincubation in insulin and cortisol medium, the LA glands retained residual cortisol during subsequent incubation in insulin and prolactin medium, and the mRNAcsn levels in these glands were related to the level of residual cortisol present. When mRNAcsn and the residual cortisol level reached a minimum, addition of fresh cortisol to the medium caused a 20-fold increase in the mRNAcsn levels. This indicates that cortisol is a limiting factor in insulin and prolactin medium and its presence is absolutely required for casein gene expression.

Animals↗