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Biomedical subjects

D Berkowitz

Publications and source records attributed to D Berkowitz.

At least 19 recordsLinked to original sources
PubMed1992

Idiopathic infantile hypercalcemia: rapid response to treatment with calcitonin.

We report on a 7-week-old infant with idiopathic hypercalcemia, hypercalciuria and nephrocalcinosis. At the time of admission, serum concentrations of parathyroid hormone and 1,25(OH)2D3 were found to be inadequately high, and those of calcitonin and 24,25(OH)2D3 too low, relative to the hypercalcemia. Treatment with calcitonin normalized serum calcium concentrations within 4 days, and a 3-week course of thiazides combined with a decreased dietary calcium:phosphorus ratio corrected the hypercalciuria. A repeat profile of the calcium-regulating hormones done at the age of 5.5 months was normal. Based on the clinical course and the hormonal profiles, we hypothesize that the idiopathic infantile hypercalcemia in this patient could have resulted from a generalized maturational delay of calcium homeostasis. Treatment with calcitonin, therefore, seems to be the most appropriate way to control the hypercalcemia.

24,25-Dihydroxyvitamin D 3↗
PubMed1990

[Actinomycosis imitating acute appendicitis].

Actinomycosis is a rare infection which can attack most parts of the body, even in normal individuals. In the gastrointestinal tract it may imitate acute appendicitis, Crohn's disease or tumors. We present a young soldier with appendiceal involvement who was mistakenly operated on. Because of its very good response to antibiotics, this infection should be recognized early and treated, to prevent prolonged, unnecessary suffering.

Actinomycosis↗
PubMed1977

Individual free fatty acids in patients with liver disease.

The total free fatty acids, blood glucose, and individual free fatty acids were studied in 8 patients with viral hepatitis and 13 with cirrhosis. The results were compared with those obtained in 9 normal control subjects. Free fatty acids were significantly elevated in liver patients as compared with normal controls. A fall in free fatty acids following ingestion of amino acids and dextrose was noted in normal subjects as well as liver patients. Glucose tolerance test, when done on patients with liver disease, was abnormal in most cases. Highly significant differences were found in the composition of individual free fatty acids in liver patients as compared with normal subjects. Arachidonic and linoleic acids were decreased, while monounsaturated and saturated fatty acids were increased in patients with viral hepatitis and cirrhosis. No significant changes were noted in the percent composition of individual free fatty acids following ingestion of amino acids and dextrose.

Adult↗
PubMed1977

Comparative dose-survival curves of representative Clostridium botulinum type F spores with type A and B spores.

Radiation survival data of proteolytic (Walls 8G-F) and non-proteolytic (Eklund 83F) type F spores of Clostridium botulinum were compared with dose-response data of radiation-resistant type A (33A) and B (40B) spores. Strain Eklund 83F was as resistant as strain 33A, whereas strain Walls 8G-F was the most sensitive of the four strains tested. The methods suggested for computing both an initial shoulder and a D value for the dose-survival curves yielded results comparable to the graphic techniques used to obtain these two parameters.

Cesium Radioisotopes↗
PubMed1976

Ampicillin-associated colitis.

Pseudomembraneous colitis has been increasingly observed after therapy with several antibiotics including ampicillin. This report describes the clinical and pathologic features of a patient who developed pseudomembraneous colitis while receiving ampicillin. The strikingly characteristic nature of these lesions is discussed and early diagnosis in the prevention of a potentially hazardous disorder is emphasized.

Adult↗
PubMed1975

Quantum chemical study of relative reactivities of a series of amines and nitriles: relevance to prebiotic chemistry.

Using the Iterative Extended Hucken Theory (IEHT) calculations of the elctron distribution and orbital energies of a series of thirteen amines, nitriles and amino-nitriles relevant to prebiotic and cosmo-chemistry have been carried out. Ground state properties such as the energy and nature of the highest occupied (HOMO) and lowest empty (LEMO) molecular orbitals, net atomic charges and number of non-bonding electrons have been identified as criteria for correlating the relative nucleophilicity of amine and nitrile nitrogens and the electrophilicity of nitrile and other unsaturated carbon atoms. The results of such correlations can be partially verified by known chemical behavior of these compounds and are used to predict and understand their role in prebiotic organic synthesis.

Amines↗
PubMed1973

Comparative resistance of nonsporogenic bacteria to low-temperature gamma irradiation.

A total of 36 microorganisms, comprising 19 species of 11 genera, were screened for radiation resistance with (60)Co gamma rays at a radiation temperatore of -80 +/- 2 C in phosphate buffer (pH 7.0) under vacuum. Micrococcus radiodurans was the most resistant organism. An initial population of 2.8 x 10(5) cells per dose of this species survived 2.4 but not 2.7 Mrad. Of the remaining 18 species with initial populations of about 10(6) cells per dose, Streptococcus faecium survived 0.9 to 1.5 Mrad, depending on the strain tested. S. faecalis QM survived 0.9 but not 1.2 Mrad. S. faecalis 1539 and Alcaligenes faecallis survived 0.6 but not 0.9 Mrad. Three species of Salmonella, one strain each of Escherichia coli, Streptococcus lactis, and Aerobacter aerogenes survived 0.3 but not 0.6 Mrad. The remaining 22 bacteria did not survive 0.3 Mrad, the lowest dose tested. Detailed survival curve determinations for four strains of S. faecium, the most resistant of the test bacteria of public health significance, indicated the following order of resistance at -80 C: alpha21 > theta12 = F(6) > FEC. Each strain produced two exponential survival curves with different slopes, the breaks occurring at 0.3 to 0.5 Mrad. The D values (doses which reduce the microbial population by 90%) of the more resistant cell fractions were two- to three-fold higher than the more sensitive cell fraction. The resistance of strain alpha21 was determined at different radiation temperature (+5, -30, -80, -140, -196 C). The D value-radiation temperature relationship followed a quadratic equation. Computations of E(a) and Q(10) values (activation energy and temperature coefficient, respectively) showed a very small thermodynamic effect on radiation death. An Arrhenius evaluation of the temperature effect on cell kill indicated that there was no simple physicochemical mechanism which might explain the change in D value as a function of temperature.

Bacteria↗
PubMed1972

Production of types A and B spores of Clostridium botulinum by the biphasic method: effect on spore population, radiation resistance, and toxigenicity.

Spores of three strains each of type A and type B Clostridium botulinum were produced both by a biphasic (solid medium overlaid with an aqueous phase) and by a "conventional" (deep broth culture) procedure. Sporogenesis by the biphasic system was more rapid, convenient, and economical, and yielded as many or more heat-resistant (80 C, 10 min) spores per milliliter as by the conventional technique. Of several aqueous phases [thiamine-hydrochloride, yeast extract, (NH(4))(2)SO(4)] tested with strain 62A, the highest spore colony counts were obtained with 2.0% (NH(4))(2)SO(4). The six strains formed maximum spore numbers in 5 to 6 days of incubation. Spores produced by the two methods had essentially equal radiation resistances (D and lag values), and their subcultures gave similar toxin titers (LD(50) values).

Ammonium Sulfate↗
PubMed1972

Radiation sterilization of prototype military foods: low-temperature irradiation of codfish cake, corned beef, and pork sausage.

"Screening" packs comprising 10 lots each of codfish cake, corned beef, and pork sausage, each lot containing about 10(6) spores of a different strain (five type A and five type B) of Clostridium botulinum per can, were irradiated at -30 +/- 10 C with a series of increasing doses (20 replicate cans/dose) of (60)Co gamma rays. The cans were incubated for 3 months at 30 C and examined for swelling, toxin, and recoverable botulinal cells. Based on the latter criterion of spoilage, median lethal dose (LD(50)) and D values were estimated for each strain in each food. The most resistant strain in codfish cake, corned beef, and pork sausage was, respectively, 53B, 77A, and 41B. There was no clear-cut trend in the comparative order of resistance between the two antigenic types among the three foods. LD(50) values gave essentially the same order of resistances as the D values and may be used interchangeably with the latter for the 10 test organisms. "Clearance" packs consisting of the most resistant strain (about 10(7) spores/can) with its respective food were irradiated with a variety of doses at -30 +/- 10 C, using 100 replicate cans/dose (about 10(9) spores/dose). These packs were incubated for 6 months at 30 C and assayed for the three types of spoilage. Based on recoverable cells, the experimental sterilizing doses (ESD) for codfish cake, corned beef, and pork sausage were 2.5< ESD </= 3.0, 2.0 < ESD </= 2.5, and 1.5 < ESD </= 2.0 Mrad, in that order. Assuming exponential spore death, the 12D values, or minimal radiation doses (MRD), were 3.24, 2.44, and 2.65 Mrad, respectively. Estimation of the MRD values by a method which assumes that spore death in the cans follows a normal distribution, yielded 3.09, 2.57, and 2.39 Mrad, respectively. Weibull analyis of the pooled 10-strain viable cell spoilage data of the screening packs for codfish cake or corned beef suggested that spore death in the cans follows a normal distribution yielded 3.09, 2.57, pooled data were not amenable to such analysis. Sublethal doses (0.5, 0.75 Mrad) increased the visible spoilage rate of corned beef over that of unirradiated controls. Apparently radiation-injured spores of C. botulinum were sensitized to the presence of food additives such as curing salts, NaCl, and spices.

Animals↗
PubMed1972

Mannitol sensitivity.

The addition of mannitol to cultures of Salmonella typhimurium mutants missing mannitol-1-phosphate dehydrogenase causes stasis or lysis. Mannitol-1-phosphate accumulates intracellularly to concentrations of 20 mm. The incorporation of acetate into lipid is inhibited before cell wall, protein, or nucleic acid synthesis.

Acetates↗