Biomedical subjects
Publications and source records attributed to R Ganguly.
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Serological response to cholera revaccination has been studied in a semi-closed community consisting of individuals mostly in the 2-20-years age-group. The subjects had been inoculated against cholera every year at the beginning of the local epidemic season. Pre- and post-vaccination sera were obtained from 29 subjects inoculated with cholera vaccine (test group) and 28 from subjects inoculated with TAB vaccine (control group). These sera were tested for vibriocidal and agglutination titres. The geometrical means of the vibriocidal and agglutination titres of the post-vaccination sera in the test group rose by 490% and 463% respectively. This booster effect was observed mostly in individuals in the 2-14-years age-group, who had low titres (vibriocidal </=320 and agglutination </=40) in their prevaccination samples. Revaccination, therefore, appears to be useful as a booster for individuals having low titres.
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Cell mediated immunity in the respiratory tract, operating somewhat independently of systemic cell mediated immunity CMI, has been recognized only rather recently. Local CMI has been shown to be more consistently and more potently stimulated following local administration of immunogen. In addition, in the few studies that have been done relative to protection, local immunization has resulted in greater resistance to organisms usually considered protected against by CMI. Thus, like the humoral immune system, CMI appears to operate locally in the respiratory tract, at least partially independent of systemic CMI. This paper deals with the evidence relative to local CMI, as well as a discussion of the role of the pulmonary macrophage, the mechanisms whereby local CMI may operate in protection, and the evidence for the presence of T-cell memory in the respiratory tract.
An effective influenza vaccine should be capable of providing protection against both the homologous virus strain and heterologous strains representing antigenic "drift". Two attenuated vaccines were evaluated, an A/Hong Kong/8/68 (H3N2) and an A/England/42/72 (H3N2) strain. Volunteers were immunized intranasally with either placebo or vaccine in a "double-blind" fashion in two doses, 2 weeks apart. Eighty-four subjects were challenged 30-100 days after the second dose with either the homologous or a heterologous strain. The heterologous strain for the A/Hong Kong/8/68 (H3N2) vaccinees was the A/England/42/72 (H3N2) virulent strain. The heterologous strain for the A/England/42/72 (H3N2) vaccinees was a virulent A/Dunedin/73 (H3N2) strain. Both vaccines led to good protection against both homologous and heterologous challenges. The protection rate against illness for the A/Hong Kong/8/68 (H3N2) vaccinees was 73% and 100% following homologous and heterologous challenges, respectively. The protection rate for the A/England/42/72 H3N2) vaccinees was 100% following both homologous and heterologous challenges. The protection rates against infection (as judged by antibody responses, irrespective of signs and symptoms) were also good. For the A/Hong Kong/8/68 (H3N2) vaccinees the rates were 73% (homologous) and 86% (heterologous). For the A/England/42/72 vaccinees, the rates were 72% and 60% respectively. Thus, immunity induced by these attenuated influenza vaccines extends to provide protection against related but non-identical influenza viruses.
This study examined cell-mediated immune responses of aged guinea pigs following intranasal sensitization with Bacillus Calmette Guérin (BCG). Young adult and aged guinea pigs, one and three years old, respectively, were inoculated intranasally with BCG. Changes in lung cell profile, production of migration inhibition factor (MIF) by lung derived lymphocytes and development of delayed hypersensitivity-skin (DHS) reaction to purified protein derivative (PPD) were evaluated at various time intervals. Normal lung lavage cell profiles were similar in both groups. Significant increases in total lung lavage cells occurred in both groups at 2 and 6 weeks following sensitization and corresponded with significant increases in the number of macrophages. The young adult group had significant increases in the total number of lymphocytes and rosette forming cells at 6 weeks compared to their preimmunization levels. Production of MIF was significantly greater in magnitude in the young adult group at 2 weeks compared to aged groups. The total number of animals mounting immune responses to BCG (MIF production) was also significantly lower in the aged group over the 6 week study period. DHS reaction to PPD was positive in all young adult animals, while only half of the aged guinea pigs were positive at 6 weeks. Data suggest that age adversely affects lung resistance to infection from intracellular microbial agents of the respiratory tract.
Peritoneal macrophages are used for immunologic assessment of the lymphokine, migration inhibitory factor (MIF). For this purpose, these cells are induced intraperitoneally in animals with inflammatory agents such as mineral oil (MO) and peptone water (PW). Purpose of the present study was two-fold: To assess the changes in biologic properties of guinea pig macrophages induced peritoneally with MO or PW as compared to control cells after administration of normal saline (NS); and to examine the suitability of induced macrophages to respond to MIF in vitro. Peritoneal exudate cells were harvested from guinea pigs 7 days following intraperitoneal injection of MO, PW or NS. They were enumerated in hemocytometers, their differential counts determined by Wright's stain and morphologic characteristics assessed by scanning electron microscopy. Functional activation of peritoneal macrophages was determined by lysosomal enzyme functions, as well as by yeast phagocytosis in vitro. Random cell migration and responses to migration inhibitory factor (MIF) were determined in Mackaness chambers. Mineral oil injection resulted in significantly higher yield of peritoneal macrophages. Greater than 70% of peritoneal exudate cells were macrophages in all three groups. Spread out structures and ruffled borders were seen in electron micrographs of MO induced cells. Such structures were less evident in PW induced cells and were absent in controls. Acid phosphatase (ACP) and beta-N-acetylglucosaminidase (B-NAG) activities as well as yeast phagocytosis significantly increased in MO and PW induced cells. Random migration and responses to MIF in Mackaness chambers remained comparable in the three experimental groups.
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This study analyzed influenza vaccination in a group of elderly veterans living in a Florida VA nursing home care unit (NHCU). A survey questionnaire, developed to assess veterans' vaccination status, attitude and perception, was presented orally by a technician in the form of an interview and the responses were annotated in appropriate areas of the questionnaire. Only 34% of the 202 veterans had been vaccinated within the last 12 months (compliant group), although the study subjects were in a high-risk group, i.e., 65 years of age or older, an average length of stay at the NHCU of 12 months and > 70% suffered from chronic disease(s) with a past history of smoking. Thus, the veterans not vaccinated outnumbered those who were by 2:1. Vaccine acceptance was significantly influenced by physician's advice and the subject's knowledge and fear about the vaccine. Veterans advised to take the vaccine yearly, within the last 5 years and more than 5 years ago had vaccination rates of 96.4, 57.8 and 17.6%, respectively. Veterans never instructed had an immunization rate of 0%. Over half of the veterans (50.7%) had regular contact with a physician. Therefore, more frequent physician reminders to vaccinate could enhance the yearly vaccine coverage rate. Subjects who received the vaccine previously but failed to do so on a yearly basis acted out of fear of side effects and shots (most frequent reason given; 34.3% of all reasons), misconceptions about the vaccine recommendation (27.6%), as well as lack of motivation (19.5%).(ABSTRACT TRUNCATED AT 250 WORDS)