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Biomedical subjects

B S Kramer

Publications and source records attributed to B S Kramer.

84 records · Page 5Linked to original sources

Early results of a comparative trial of ceftazidime versus cephalothin, carbenicillin and gentamicin in the treatment of febrile granulocytopenic patients.

Ceftazidime was compared with a combination of cephalothin, carbenicillin and gentamicin as empirical therapy for fever in granulocytopenic patients. Forty-eight patients were studied in this randomized trial. In the 44 evaluable cases, favourable clinical responses were seen in 9/21 ceftazidime-treated cases and 13/23 patients treated with the combination. Four of 5 bacteraemias were cured with ceftazidime and 3 of 4 with triple therapy. Comparable numbers of patients developed new fevers while on therapy. Five ceftazidime-treated patients developed documented superinfection compared to 6 patients in the other group. Five patients treated with ceftazidime died from the initial infection or a superinfection compared with 3 on the combination. The overall results appear to be similar at this time. However, remarkable differences were observed between the types of superinfecting organisms with the two regimens. If all 48 patients are considered the isolates were as follows: ceftazidime treatment--5 clostridia, 3 enterococci, 1 Staphylococcus epidermidis and 1 Citrobacter; cephalothin-carbenicillin-gentamicin treatment--4 Pseudomonas, 1 Escherichia coli, 1 Bacteroides fragilis and 2 Candida spp. These results suggest that Gram-positive coverage should be added to ceftazidime in the empirical treatment of febrile granulocytopenic patients.

Adult↗

Efficacy of injectable and oral paste formulations of ivermectin against gastrointestinal parasites in ponies.

A controlled test was used in ponies to compare the antiparasitic efficacy of ivermectin (22,23-dihydro-avermectin B1) in an injectable micelle solution administered IM with the efficacy of the same drug in an oral paste formulation. Parasite infections were naturally acquired in southern Louisiana. The drug was tested in both formulations at a dosage level of 0.2 mg/kg of body weight. Ivermectin in both formulations tested had an efficacy greater than 98% against Gasterophilus intestinalis and G nasalis larvae. Trichostrongylus axei, Habronema spp, Strongylus vulgaris, S. edentatus, and species of small strongyles present. Efficacy of ivermectin against Oxyuris equi larvae was 100% in the paste formulation and 93% in the injectable formulation. The ponies were less uniformly infected with S equinus, Draschia megastoma, Parascaris equorum, O equi adults, Anoplocephala perfoliata, and A magna. However, observations indicated that the drug in either formulation was also effective against these parasites, except Anoplocephala spp.

Administration, Oral↗

Biochemical characterization of the amphotropic group of murine leukemia viruses.

The recently described amphotropic group of murine leukemia viruses constitutes a distinct biological group, differing from the ecotropic and xenotropic groups in host range, cross interference, and serological reactivity. Viruses of this group have been detected only in wild mice from certain areas in California. By using a [3H]DNA probe synthesized in an endogenous reaction from detergent-lysed amphotropic virus (strain 1504-A), it was demonstrated that the amphotropic murine leukemia viruses are distinct biochemically, in that 20% of the viral genome sequences are not shared by AKR-type ecotropic or nay of three types of xenotropic murine leukemia virus tested. A subset of these amphotropic unique sequences, comprising one half of them, is present in the genome of wild mouse ecotropic viruses and in Moloney and Rauscher viruses as well. Sequences homologous to the entire genome of 1504-A amphotropic virus are present in the cellular DNA of all eight inbred mouse strains tested, as well as in wild Mus in Asia, in amounts varying from three to six complete viral genomes per haploid cell genome. Evidence is presented that at least 20% of the DNA sequences in both mouse- and mink-grown murine leukemia virus probes are of host-cell origin.

Animals↗

Cutaneous infarction. Manifestation of disseminated mucormycosis.

We describe the second reported case of cutaneous infarction as a manifestation of disseminated mucormycosis. The lesion, which closely resembled ecthyma gangrenosum, occurred in a leukemic patient who was on a regimen of broad-spectrum antibiotics. In this case as in the only other reported case, Mucor pusillus was the cause.

Adult↗

Reaction of 1,3-bis(2-chloroethyl)-1-nitrosourea with synthetic polynucleotides.

The antitumor agent BCNU (1,3-bis(2-chloroethyl)-1-nitrosourea) was incubated with poly(C) and poly(G) in aqueous solution at 37 degrees and pH 7 to produce approximately 0.33 and 0.07% substitution, respectively. Under the same conditions, there was relatively little reaction with poly(A) and poly(U). Poylnucleotides reacted with [14C]BCNU were digested by chemical and enzymatic methods, and the derivative nucleotides were isolated by column chromatography. There were identified by a combination of ultraviolet and mass spectroscopy as 3-(beta-hydroxyethyl)CMP, 3,N4-ethano-CMP, and 7-(beta-hydroxy-ethyl)GMP. This would indicate that BCNU generates active two carbon fragments, probably chloroethyl carbonium ions, which are free to react with nucleotides. The production of these substituted bases may be important to the mechanism of action of the therapeutic nitrosoureas since they would probably alter the function of any nucleic acid which contained them.

Carmustine↗

Ultrastructural pathology of human T-cell lymphotropic virus type I encephalomyelopathy in a white patient with adult T-cell leukemia/lymphoma.

A white patient with human T-cell lymphotropic virus type I (HTLV-I)-associated adult T-cell leukemia/lymphoma for 10 years died 4 months after the onset of spastic myelopathy. Ultrastructurally, the neuropathologic findings consisted of dystrophic neurites (spheroids) filled with neurofilaments or electron-dense bodies, intense astrocytic reaction with abundant formation of corpora amylacea, and multilamellar bodies. Demyelination and spongiform change were absent. Viruslike particles resembling HTLV-I were detected adjacent to brain endothelial cells.

Human T-lymphotropic virus 1↗

Chemoprevention.

Chemoprevention has been shown to be an extremely promising approach to the prevention of invasive cancer. Through the identification of chemopreventive agents that inhibit or reverse the process of carcinogenesis, new strategies of early intervention can be developed for patients at high risk that potentially prevent the onset of invasive and metastatic phases of cancer. This articles reviews the present efforts in chemoprevention research, including the identification of promising agents, screening, and preclinical and clinical evaluations.

Animals↗