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Biomedical subjects

L Cohen

Publications and source records attributed to L Cohen.

At least 469 records · Page 26Linked to original sources
PubMed1982

Specific cytosol binding of diethylstilbestrol in rat skeletal muscle.

Rat skeletal muscle cytosol proteins bound 3H-diethylstilbestrol (3H-DES). More than 90% of this binding was high capacity and low affinity. Serum albumin accounted for roughly 50-60% of the binding, as evidenced by its precipitation with anti-rat albumin IgG. About half of the binding was distinguishable from albumin and other serum proteins by its precipitation in 40% saturated ammonium sulfate. This material sedimented at 4-5S in high-salt sucrose gradients, and resolved into two components (8S and 4-5S) in low-salt. Following incubation at 23-27 degree C for one hour, 2% of the bound 3H-DES in whole cytosol (approximately 2 fmole/Mg cytosol protein) was retained by DNA cellulose, and was eluted with 0.6 M KCl. This small fraction of the total binding was inhibited by estrogens and DES analogues: estradiol-17 beta, DES, dienestrol, and hexestrol were strong inhibitors; isodienestrol, dimethylstilbestrol, estradiol-17 alpha, estrone, tamoxifen, MER-25, CI-628, and nafoxidine were weak inhibitors; dihydrotestosterone, testosterone, and prednisone did not compete. These observations indicate that specific estrogen-binding sites exist in rat skeletal muscle.

Ammonium Sulfate↗
PubMed1982

Research in the Netherlands on a theory of child abuse: a preliminary report.

A three-factor theory of child abuse has been developed which includes: (1) a high level of parental aggression; (2) a low level of parental inhibition of overt aggression; and (3) the focusing of parental aggression on the child. In the theory each factor is the outcome of a subfactor "path." A high level of parental aggression is the outcome of seven subfactors. A low level of parental inhibition of overt aggression is the outcome of three subfactors. The focusing of parental aggression on the child is the outcome of ten subfactors. The theory posits that the type of child abuse that occurs is determined by the ratio of total parental aggression to total parental inhibition of overt aggression. High numerical values of the ratio result in battering. Lower numerical values result, in descending order, in non-organic failure to thrive, physical neglect and emotional abuse. The theory and 50 hypotheses derivable from it are being tested on a sample of 150 child-abuse families and 150 control families.

Aggression↗
PubMed1982

Absence of a demonstrable gain factor for neutron beam therapy of epidermoid carcinoma of the head and neck.

A comparison of normal tissue and tumor responses in patients treated with the high energy Fermilab neutron beam and conventional photons (Cobalt and 4 MeV X rays), yielded the following parameters. For neutrons the median dose for significant radiation injury in the irradiated tissues was 31 (+2) Gy and the median dose for local control of the tumor was 26 (+2) Gy. The corresponding doses for photons were 90 (+4) Gy for normal tissue injury and 74 (+3) Gy for local control of the tumor. These figures show that the therapeutic ratio is roughly 1.2 for both neutrons and photons. Similarly, the RBE of neutrons relative to photons is about the same for normal tissue tolerance and for tumor control. Under these conditions, there is no demonstrable therapeutic gain factor for neutrons relative to photons. The overall local control rate was the same for both modalities (44%).

Carcinoma, Squamous Cell↗
PubMed1982

Expanding options in radiation oncology: neutron beam therapy.

Twelve years' experience with neutron beam therapy in Britain, the USA, Europe and Japan shows that local control is achievable in late-stage epidermoid cancer somewhat more frequently than with conventional radiotherapy. Tumours reputed to be radioresistant (salivary gland, bladder, rectosigmoid, melanoma, bone and soft-tissue sarcomas) have proved to be particularly responsive to neutrons. Pilot studies in brain and pancreatic tumours suggest promising new approaches to management of cancer in these sites. The availability of neutron therapy in the clinical environment opens new prospects for irradiation of 'radioresistant' tumours, permits more conservative cancer surgery, expands the use of elective chemotherapy and provides a wider range of options for cancer patients.

Brain Neoplasms↗
PubMed1982

Speech development in aphonic children.

It has been well established that pre-lingually hearing-impaired children experience difficulties in speech development. Little appears in the literature, however, about speech development in aphonic children. The authors have had the opportunity to manage several children who, for various reasons, were unable to phonate from a pre-lingual age to approximately the age of 5 or 6 years. The children in this report developed various compensatory means of communication, including unusual laryngeal, non-laryngeal and nonverbal communication. Representative cases are reviewed and observations are made regarding the effects of aphonia on speech development.

Aphonia↗
PubMed1982

Increased Frequency of Apo E-ND phenotype and hyperapobeta-lipoproteinemia in normolipidemic subjects with xanthelasmas of the eyelids.

Apolipoprotein E isomorphs in very low density lipoproteins and apolipoprotein B of low density lipoproteins were measured in the plasma of normolipidemic subjects with xanthelasmas of the eyelids and in appropriate control groups. All patients tested in the experimental group had an apolipoprotein EII to apolipoprotein EIII ratio typical of the heterozygous state for familial dysbetalipoproteinemia, a hyperapobetalipoproteinemia, or both. Some patients had concomitant atherosclerosis. This is the first report of an increased frequency of the apolipoprotein E-ND phenotype in normolipidemic xanthelasma. This condition should not be dismissed as benign; tissue lipid deposition in the absence of hyperlipidemia might be related to the presence of lipoproteins of abnormal composition with an enhanced atherogenic potential.

Adult↗
PubMed1982

Relationship of bone and plasma magnesium in magnesium-deficient cirrhosis patients.

Total and ionized plasma Mg levels and cortical and trabecular bone Mg concentration were determined in five untreated nonalcoholic cirrhosis patients with ascites and edema. The high peripheral renin activity and serum aldosterone proved the existence of secondary aldosteronism in these patients. Total plasma Mg and trabecular bone Mg were within normal limits. A decreased absolute level and percentage of ionized plasma Mg were found without hypoalbuminemia, and cortical bone Mg concentration was decreased. Ionized plasma Mg concentration correlated closely with cortical bone Mg concentration when the levels of bone and plasma Mg were below normal.

Ascites↗
PubMed1982

A statistical analysis of the loss of muscle strength in Duchenne's muscular dystrophy.

We have confirmed that the loss of muscle strength in 12 boys with Duchenne's muscular dystrophy, as measured by manual muscle testing, approximates a linear decay model, but we have also found that it fits as well a first order decay model. The strength in the same eight muscles was measured over time. Results of an analysis of 111 examinations are reported here. An arbitrary numerical scale for grading muscle strength was used, such that normal was 13 units, and no movement was zero. The maximal sum, if all 8 muscles were normal, would be 104 units. Pooling all measurements, the linear decay rate in this sum was -0.189 +/- 0.023 (estimate +/- standard error) arbitrary muscle strength units . month-1. The corresponding first order fractional decay rate was -0.0034 +/- 0.0004 month-1. However, a more detailed statistical analysis indicated that decay rates in muscle strength were not homogeneous, i.e. muscle strength decayed faster in some patients than others. The decay constants in 11 of the 12 subjects spanned a 10-fold range, and in one subject increased the spread to 40-fold. The distribution frequency of decay rates appears to be bimodal. In these assessments, the muscle strength at time zero was not known. Therefore, an estimate of muscle strength at 10 years was made. This varied from 34 to 71 units. The group mean was 53.0 units using the exponential model, i.e. on average, only 51% (= 53.0/104 X 100) of the normal muscle strength remained in the 8 muscle groups assessed at age 10 years. In conclusion, a quantitative characterization of muscle strength deterioration is reported, which emphasizes the heterogeneity in this disease. This approach may eventually allow quantitative distinctions between Duchenne's and Becker's varieties of muscular dystrophy.

Adolescent↗
PubMed1982

The effect of pH on enzyme leakage from isolated mouse heart.

A series of tris-maleate-buffered salt solutions, from pH 6.4 to 8.9 was used to assess the effect of pH on the two hour leakage of creatine kinase (CK) from isolated mouse heart. Leakage was directly related to pH. Hourly enzyme leakage was minimal (less than 0.25%) at pH 6.4, but from pH 6.4 to 8.9, it increased more than 10 fold. The pattern of fractional leakage in the second hour, relative to pH, was approximately sigmoidal in shape, and similar to a monoprotic titration curve. This observation suggests that a single proton binding site may govern myocardial enzyme leakage, under the conditions of this study. Similar observations were made using salt solutions, buffered with tris-HCl, from pH 7.3 to 8.6. The functional group of this putative protective site has a pKa of approximately 7.9, and properties consistent with a nitrogen base of the type found in terminal amino, epsilon-amino, and/or imidazolium groups.

Animals↗