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Biomedical subjects

A Cohen

Publications and source records attributed to A Cohen.

At least 667 records · Page 37Linked to original sources
PubMed1987

Localization of radioiodinated monoclonal antibody in colorectal cancer. Initial dosimetry results.

HT-29-15 is an IgG1 monoclonal antibody reacting with a neuraminidase-sensitive determinant on a cell-surface antigen (molecular weight, 200,000 daltons) present on the colon cancer cell line HT-29. HT-29-15 was selected for a tumor localization study because the antigen was shown to be present, by immunohistochemical staining, in a high percentage of primary and metastatic colorectal cancers. HT-29-15 labeled with iodine 131 was given intravenously over a dose range of 0.2 to 10.0 mg to 23 patients with colorectal cancer. No significant toxicity was seen. Imaging of hepatic metastases was successful from days 5 to 7. Analysis of tissue radioactivity by biopsy showed that the tumor-liver ratio increased from day 1 to day 7, suggesting more rapid clearance of antibody from normal tissue than from tumor. Thus, tissue biopsy specimens and scintigraphy have shown that imaging of metastatic colorectal cancer is possible with monoclonal antibody HT-29-15. Tissue biopsy specimens are essential for demonstrating specificity of localization. Scans alone provide insufficient evidence of specific localization by monoclonal antibodies. Simultaneous infusion of a nonreactive control antibody would be necessary for specific localization to be demonstrated unequivocally.

Animals↗
PubMed1987

A multiple-dose pharmacokinetic comparison of naproxen as a once-daily controlled-release tablet and a twice-daily conventional tablet.

The bioequivalence and absorption kinetics of naproxen in a new controlled-release tablet (750 mg or 1,000 mg naproxen) administered once daily were determined relative to an equivalent dose of the conventional naproxen tablet (375 mg or 500 mg naproxen) administered q12h. Naproxen was well absorbed from the controlled-release tablet (about 90%) compared with the conventional tablet. Absorption was dependent on drug release from the tablet matrix. The mean absorption time of naproxen averaged 8.4 hours for the 750-mg controlled-release tablet and 9.2 hours for the 1,000-mg controlled-release tablet. Once-daily administration of the controlled-release tablet resulted in equivalent trough concentrations of naproxen, and steady-state plasma concentrations were maintained within narrower limits than with twice-daily naproxen.

Adult↗
PubMed1987

Pediatric infiltrating lipomas: case report and review of the literature.

A case of pediatric infiltrating lipoma and a collected literature review of four pediatric patients with well-documented infiltrating lipomas are presented. These lesions tend to recur after resection but there are no reported incidences of distant metastases or degeneration into frankly malignant lesions. Treatment consists of excising the lesion with a margin of normal muscle.

Child↗
PubMed1987

Purine nucleotide metabolism in phytohemagglutinin-induced human T lymphocytes.

The comprehensive studies of purine nucleotide metabolism were done in nonstimulated and phytohemagglutinin (PHA)-stimulated human peripheral blood T lymphocytes. Nonstimulated lymphocytes synthesize nucleotides in two alternative pathways: via biosynthesis de novo and salvage pathways. Although synthesis of triphosphonucleosides in unstimulated lymphocytes was the predominant pathway, interconversion of monophosphonucleosides was also active. Exposure of cells to PHA affects differently various pathways of nucleotide metabolism. The most marked changes observed were rapid activation of purine salvage within minutes after exposure to PHA, and significant increase of 5-phosphoribosyl-1-pyrophosphate levels. In addition, significant increases were found in de novo purine biosynthesis, nucleotide interconversions, and RNA and DNA synthesis, whereas catabolism of nucleotides remained unchanged. These results indicate that PHA activation of T lymphocytes causes a rapid synthesis of nucleotides which may be required immediately for increases in energy metabolism and later as the precursors of nucleic acid synthesis.

Adenine↗
PubMed1987

An outbreak of Campylobacter jejuni infection in a neonatal intensive care unit.

During a period of 2 weeks Campylobacter jejuni infection was diagnosed in seven infants in a neonatal intensive care unit. An identical serotype of Camp. jejuni was found in five of the cases. Investigations suggested that a common source of infection or infection acquired from mothers during delivery were unlikely. The dates of onset and the common serotype indicate that the outbreak may have been caused by person-to-person spread.

Campylobacter Infections↗
PubMed1987

Isolation of Legionella pneumophila from calves and the prevalence of antibodies in cattle, sheep, horses, antelopes, buffaloes and rabbits.

The lungs of 139 calves presented for autopsy and 29 healthy slaughtered calves were examined for Legionella by culture and by direct immunofluorescence (DIF) with fluorescein-conjugated antisera. About 17% of the cadaver lungs and 4% of lungs from slaughtered animals were positive by DIF. Legionella organisms were only isolated from the lungs of two cadavers (L. pneumophila, serogroup 1). In a prevalence study of antibodies to Legionella in domestic and wild animals of various species, titers of greater than or equal to 64 were demonstrated by indirect immunofluorescence in sera of 10% of dairy cattle, 5% of beef cattle, 4% of sheep, 22% of antelopes, 35% of horses, 36% of buffaloes and 0% of laboratory rabbits. The isolation of Legionella from lung tissue is evidence for a possible etiologic role of Legionella spp. in natural pathology of animals.

Animals↗
PubMed1987

Total thyroidectomy. The preferred option for multinodular goiter.

Total thyroidectomy is an operation that has generally been reserved for the management of differentiated thyroid carcinoma. Over the last decade total thyroidectomy has become used increasingly and is now the preferred option in the authors' unit for the management of multinodular goiter affecting the entire gland. Over the period from 1975 to 1985, 853 thyroidectomies have been performed for multinodular goiter; of these, 115 have been total thyroidectomies. During that time, the incidence of total thyroidectomy for multinodular goiter has increased in percentage terms from 9% in 1975 to 50% in 1985. There have been two cases of permanent hypoparathyroidism and one case of permanent recurrent laryngeal nerve injury, and these occurred in patients who had less than total thyroidectomy. Total thyroidectomy is an appropriate operation for the management of diffuse multinodular goiter where the entire gland is involved because it precludes patients from requiring further surgery for recurrent disease, with its high associated risks. It must be emphasized, however, that protection of the recurrent laryngeal nerve and parathyroid glands must still be paramount in dealing with benign thyroid disease.

Goiter, Nodular↗
PubMed1987

Synthesis of linear multimers of OriC and pBR322 derivatives in Escherichia coli K-12: role of recombination and replication functions.

Inactivation of RecBCD nuclease (exonuclease V) and SbcB nuclease (exonuclease I) in Escherichia coli K-12 diverts most of plasmid replication activity from circular monomer production to the synthesis of linear multimers. Linear multimer synthesis has been demonstrated in plasmids of diverse origins and copy numbers, including E. coli minichromosomes. The effect of dnaA, dnaB, recF, and recJ mutations on the rate of linear multimer synthesis in sbcB cells after gam inactivation of RecBCD nuclease was investigated. Results are consistent with the hypothesis that homologous recombination, but not activities at the plasmid origin of replication, is involved in initiation of linear multimer synthesis.

Bacterial Proteins↗
PubMed1987

Fifty cases of late prosthetic valve endocarditis: improvement in prognosis over a 15 year period.

The clinical course, prognostic factors, and management of 50 cases of late prosthetic valve endocarditis, occurring more than two months after valve replacement, were reviewed. Twenty nine cases that presented from 1971 to 1980 were compared with 21 cases that presented from 1981 to 1985. Apart from an appreciable decrease in the frequency of neurological complications between the first period (38%) and the second period (10%) no differences in clinical or bacteriological features were seen. Seventeen (59%) of the 29 cases in the earlier period and four (19%) of the 21 cases in the later period died. The rationale for antimicrobial treatment was similar during both periods. Cardiac surgery was performed in eight of 29 cases between 1971 and 1980 and in 11 of 21 between 1981 and 1985; the mean (SD) time between diagnosis of endocarditis and operation was 28 (19) days and 43 (44) days respectively. Six of the eight cases operated on in the first period died as did two of the 11 operated on in the second period. Twenty seven of the 29 cases presenting between 1971 and 1980 were treated with anticoagulants--either warfarin (15 of 27) or heparin sodium (12 of 27). Sixteen of the 21 cases presenting later were given anticoagulants and 15 of these cases were given heparin sodium. Control of anticoagulation was inadequate in nine of the 27 cases treated with anticoagulants during the first period and in only two of 16 treated during the second period. During the first treatment period neurological complications were more frequent when control of anticoagulation was inadequate.

Adult↗
PubMed1987

A scale for measuring persistence in children.

Persistence and its assessment have been studied since the 1920s. One common approach in measuring persistence has been through testing the subject's ability to solve difficult or monotonous problems. Another approach has been through questionnaires. Although persistence is very important in academic achievement and in the general development of personality, no questionnaires have been developed for measuring persistence in children. The present research concerns the development of such a scale. It includes 40 items and was tested on 322 Israeli children aged 7-13. The internal reliability of the scale (Cronbach alpha) was .66, and the test-retest reliability after 6 months was .77. The scale differentiated active gymnasts from non-gymnasts as well as persistent gymnasts from dropout gymnasts. In addition, significant correlations were found between the scale and the need-persistence measure of the Rosenzweig Picture Frustration Study, Locus of Control, and other measures. We discuss these findings along with the significance of persistence in everyday life.

Journal Article↗
PubMed1987

Abusers of alcohol and narcotics: who are they?

Problem drinking among addicts was studied by interviewing 781 narcotic addicts on entrance to treatment. Hierarchical multiple regression analysis (MRA) assessed the ability of 56 demographic, childhood, psychological, social, and drug history measures to predict abstinence, alcohol consumption among nonabstainers, and alcohol-related problems among heavy drinkers. MRA explained 33% of lifetime problem-drinking variance. Best predictors were traumatic events and hyperactivity in childhood, residential instability, psychopathology, and seriousness of drug problems. It was concluded that problem-drinking addicts may differ from other addicts in kind as well as in degree. The findings suggest that problem drinking in narcotic addicts may serve as a marker for some serious psychological problems, that drug treatment professionals therefore should be trained in alcohol abuse identification and treatment, and that psychiatric consultation for these addicts should be available.

Adult↗