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Biomedical subjects

S Berman

Publications and source records attributed to S Berman.

At least 127 records · Page 7Linked to original sources
PubMed1976

Sublimation of formaldehyde in freeze-drying.

Formaldehyde solution, commonly used to inactivate bacterial, rickettsial and viral suspensions during the preparation of vaccines, is known to have a deleterious effect on many antigens during freeze-drying. Sublimation of formaldehyde in shell-frozen and plug-frozen aqueous samples was investigated by measuring the residual formaldehyde periodically during the freeze-drying procedure. It was found that formaldehyde, even while subliming, concentrated on a volume basis. This was more apparent with the plug-frozen than with the shell-frozen material. Moreover, in the preparations taken to dryness, the formaldehyde polymerized to form paraformaldehyde. It was found that the addition of methanol not only prevented polymerization, but also significantly increased the sublimation of formaldehyde without concentration of the latter.

Acetals↗
PubMed1975

Prostaglandin E2 effects on cation flux in sickle erythrocyte ghosts.

Prostaglandin E2 has previously been shown to enhance the shape transformation of sickle prone erythrocytes (8) and to reduce the oxygen resaturation of Hemoglobin SS within intact sickle cell erythrocytes after deoxygenation (15). In view of the recent importance attributed to calcium transport in maintaining erythrocyte shape and viability (10) and the suggestion that prostaglandins may act via a calcium ionophore mechanism (9) on cell membranes, erythrocyte ghosts were prepared following the method of Lepke and Passow (12) from normal and sickle cell anemia erythrocytes. These two classes of ghosts are shown to display differing patterns of sodium and calcium transport, whith calcium influx being preferentially stimulated by prostaglandin E2 in sickle cell ghosts. It is suggested that in hypoxic, stasis conditions in vivo, prostaglandins may play a role in accelerating sickling of sickle prone erythrocytes via stimulation of calcium influx.

Anemia, Sickle Cell↗
PubMed1972

Evaluation of a new cephalosporin antibiotic, cephapirin.

Cephapirin sodium, a parenterally administered derivative of cephalosporanic acid, was tested in vitro against 150 stock cultures of Enterobacteriaceae and 30 stock cultures each of Pseudomonas aeruginosa and Staphylococcus aureus. Both broth- and agar-dilution techniques were employed with two sizes of inocula of organisms. At a concentration of 7.5 mug or less/ml, cephapirin inhibited and killed 100% of strains of Escherichia coli and Proteus mirabilis and more than 80% of Klebsiella species when tested against an inoculum of 10(5) bacterial cells/ml. However, even at 100 mug/ml, only a few isolates of other Enterobacteriaceae and Pseudomonas were inhibited. A 100-fold increase in the inoculum resulted in decreased susceptibility of organisms. All penicillin-susceptible as well as penicillin-resistant S. aureus isolates were inhibited and killed by 5 mug or less of cephapirin/ml when tested with an inoculum of either 10(4) or 10(6) organisms/ml. The drug also was studied in various doses in the treatment of 77 patients with diverse infections. Cephapirin was effective in the treatment of 27 of 32 patients with pulmonary infection, as well as in 6 of 7 patients with staphylococcal or streptococcal soft tissue infection. Of 25 patients with urinary-tract infections, 19 developed a negative culture during therapy. A single 4-g intramuscular dose of cephapirin was effective in only 2 of 11 patients with gonococcal urethritis or endocervicitis. Two patients with gonococcal urethritis treated with multiple injections were cured. The drug was well tolerated except for pain at the site of injection in 14 patients and phlebitis in 4 patients. No abnormalities in renal or hepatic function could be attributed to cephapirin. In addition, no abnormalities were found in the renal tubules of rabbits challenged with 500 mg of cephapirin/kg. If further studies document that cephapirin is well tolerated by the parenteral route, it may have advantages over cephalothin or cephaloridine.

Acetamides↗
PubMed1972

Mouse potency assay for Western equine encephalomyelitis vaccines.

A potency assay for Western equine encephalomyelitis vaccine was developed which utilized mice as the test animal instead of guinea pigs or hamsters. By immunizing several groups of mice with dilutions of the vaccine and challenging them intracerebrally with virulent virus, it was possible to determine mathematically a dose of vaccine capable of protecting 50% of the animals (ED(50)). When log dilutions of virulent virus were used to challenge mice which were immunized with dilutions of the vaccine, there was no difference among the ED(50) values for the dilutions of challenge virus. In a direct comparison of ED(50) values determined from the immunization of mice and those determined from the immunization of guinea pigs, there were no differences in the rankings of the vaccines.

Animals↗
PubMed1972

Stable reagent for the detection of antibody to the specific fraction I antigen of Yersinia pestis.

A stable hemagglutinating antigen for detection of fraction I (FR-I) antibody of Yersinia pestis (Pasteurella pestis) is described. The antigen was prepared by sensitizing tanned, pyruvaldehyde-treated sheep erythrocytes (PAT SRBC) with FR-I antigen. Preliminary standardization by titration of each lot of FR-I was required to minimize the effect of molecular heterogeneity of specific FR-I antigen and to eliminate nonspecific reactions caused by the presence of a minor antigenic contaminant. In tests with sera from rabbits, dogs, and humans, FR-I PAT SRBC were as reactive as the previously employed standard antigen, FR-I-sensitized tanned erythrocytes. Fluid suspensions of FR-I PAT SRBC stored at 4 C for 3 months, or lyophilized preparations stored at ambient temperature for 6 months, showed no loss in antigenic activity.

Aldehydes↗
PubMed1972

Preparation of purified suspensions of Coxiella burneti by Genetron extraction followed by continuous-flow ultracentrifugation.

A method for the preparation of purified suspensions of Coxiella burneti by Genetron extraction followed by continuous-flow density gradient ultracentrifugation is described. Both phases of the Henzerling strain of C. burneti were found in a zone between 53 and 65% (w/w) sucrose. Based on chemical assays, the Genetron zonal rickettsial suspensions were found to be as pure as the rickettsial suspensions which were prepared by the ether extraction method currently in use for producing Q fever vaccines for human use.

Animals↗
PubMed1972

Comparative immunogenicities of Chikungunya vaccines propagated in monkey kidney monolayers and chick embryo suspension cultures.

A comparative study was made of Formalin-inactivated Chikungunya vaccines prepared from the virus propagated in African green monkey kidney monolayers and concentrated chick embryo suspension cultures. The vaccine prepared in the chick embryo suspension cultures was significantly more protective to mice against a live homologous virus challenge and stimulated the production of 4 to 5 times more circulating antibodies than the vaccine prepared with virus grown in African green monkey kidney monolayer cultures.

Animals↗
PubMed1971

Inactivated eastern equine encephalomyelitis vaccines prepared in monolayer and concentrated suspension chick embryo cultures.

Eastern equine encephalomyelitis vaccines were prepared with virus propagated in stationary monolayer cultures and in concentrated suspension cultures of primary chick embryo cells. Virus pools for vaccine preparation were inactivated by three different methods: 0.05% formalin, 41 C heat, and 0.16% beta-propiolactone. Heat-and beta-propiolactone-inactivated vaccines maintained high hemagglutinating titers in the fluid state for at least 10 months, whereas formalin-inactivated vaccines lost their hemagglutinating activity within a few hours after treatment. The hemagglutinin of beta-propiolactone-inactivated virus particles was more dense than the hemagglutinin of the parent virus particles, as determined by sucrose density gradient centrifugation. The increase in density may be due to the degradation or removal of the lipid from the virus envelope. When administered to guinea pigs, all three vaccines stimulated hemagglutination-inhibiting, complement-fixing, and neutralizing antibodies and afforded protection against a live virus challenge. Test results showed that vaccines prepared with virus propagated in concentrated suspension cultures were more immunogenic and stimulated greater serologic responses in guinea pigs than vaccines derived from monolayer-propagated virus. The beta-propiolactone-inactivated vaccine was most protective, the heat-inactivated (41 C) vaccine next, and the formalin-inactivated vaccine least potent.

Animals↗