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Biomedical subjects

A Cohen

Publications and source records attributed to A Cohen.

At least 847 records · Page 47Linked to original sources
PubMed1982

Declination: construct or intrinsic feature of speech pitch?

Declination is taken as the focus of studying pitch phenomena from an acoustic, physiological and perceptual point of view. It is shown that originally declination was no more than a theoretical construct to account for the interpretation of acoustic F0 recordings. Recently, psycholinguistic considerations have enhanced the domain of application so as to account for this phenomenon. The literature is reviewed and the authors take issue over the various claims put forward by others, such as the dominance of the topline over the baseline approach, and the amount of pre-programming involved in declination, as manifested in its slope and in linguistically determined resetting.

Humans↗
PubMed1982

The "urge to classify" the narcotic addict: a review of psychiatric classification. I.

Attempts to classify drug addicts are divided into three main groups: (1) psychiatric classifications, (2) psychological classifications, and (3) classifications by pattern of abuse. An extensive literature review of the psychiatric classifications of narcotic addicts suggests that there is no one diagnosis that fits all narcotic addicts and that the importance of psychopathology in drug addiction has been exaggerated. It is concluded that theoretical psychiatric classifications of narcotic addicts have failed to stimulate empirical research and that empirical classifications have not demonstrated their utility for treatment and prognosis.

Humans↗
PubMed1982

[Distribution of glucocorticosteroids between free and bound fractions in maternal, fetal, and neonatal plasma in rats, during the perinatal period].

In delivering rats on day 21 of pregnancy, in the afternoon, the free plasma corticosterone concentration is not statistically different from the value found in pregnant females which have not yet delivered at the same stage of pregnancy in the afternoon; moreover there seems to be an equilibrium between maternal and foetal concentrations. In the just expelled newborns, the free plasma corticosterone concentration is much higher than the value found in the littermate foetuses remaining in utero.

Animals↗
PubMed1982

Antithymocyte globulin in cadaver renal grafts: prophylaxis and antirejection therapy with three different preparations.

Three different preparations of antithymocyte globulin were used to treat recipients of cadaver kidney transplants. Twenty patients received Connaught Institute/Armand-Frappier ATG prophylactically beginning on the day of grafting and achieved superior graft and patient survival compared to 18 concurrent controls. Pressimmune as a 5-day course was able to reverse steroid resistant rejections in 20 of 31 recipients as was ATGAM in three of six treated patients receiving it for 10 days. These short courses were associated with a 16% early and a 10% late relapse rate. The combination of high steroid therapy, maintenance azathioprine and ATG was associated with an infection rate of 22%.

Antilymphocyte Serum↗
PubMed1982

Regulation of macrophage-mediated suppression by purine nucleoside phosphorylase substrates.

Thymuses from dexamethasone-treated rats contain macrophage-like cells that completely suppress the proliferative response of thymocytes to concanavalin A. This macrophage-mediated suppression is abolished by low concentrations of purine nucleoside phosphorylase (PNP) substrates: deoxyguanosine (20 microM), guanosine (100 microM), and deoxyinosine (250 microM). Similar effects were observed when resident peritoneal macrophages were used. Deoxyguanosine regulates suppression by acting directly on macrophages. The mode of deoxyguanosine action on macrophages does not involve its phosphorylation and incorporation into deoxynucleotide pools. The significance of this regulation of macrophage-mediated suppression by PNP substrates to immune regulation in normals and in PNP-deficient patients is discussed.

Animals↗
PubMed1982

Trends in human factors research.

As just described, NIOSH's ongoing and new activities offer varied approaches and opportunities for gaining insights into human factor and ergonomic aspects of workplace hazards and their control. They represent a blend of surveillance work (re, the prevalence survey of chronic trauma risk), in-depth studies of known workplace problems emphasizing undue physical and psychological job demands and their consequences (re, stress from machine-paced work and musculoskeletal problems from repeated lifting), first evaluations of the consequences of new technology (re, use of video display terminals), and finally problem-solving efforts (re, the evaluation and field testing of the work practice guide for reducing lifting hazards and control technology assessment). Taken together, these efforts signal an important new commitment by NIOSH in making workplaces safe for our working men and women.

Beta Particles↗
PubMed1982

Comparison of two isotope dilution/mass spectrometric methods for determination of total serum cholesterol.

Isotope dilution/mass spectrometric methods for total serum cholesterol, developed separately at the Karolinska Institutet (KI) and the National Bureau of Standards (NBS), were compared by applying them to a common set of serum pools. A search for the cause of a systematic difference of a few percent in results from the two methods revealed that the KI cholesterol standard contained lathosterol, which interfered with the calibration of the method. With NBS Standard Reference Material cholesterol used for new analyses at the KI, the average difference in mean values dropped to 0.2%. The NBS results are more precise. This is attributed to the protocols NBS used for sample preparation and mass spectrometry. However, these protocols make the NBS method more complex and time-consuming. A recent critical article on the use of this technique for total cholesterol is also examined.

Cholesterol↗
PubMed1982

Tissue immunoglobulins and early recurrence in Crohn's disease.

The early recurrence rates following surgical treatment of Crohn's disease are distressingly high. In clinical studies in which an attempt is made to correlate duration, severity and extent of disease, the prediction as to which patients are prone to have the disease recur was not successful. The immunoglobulin G value is elevated in the diseased portion and in 50 per cent of the normal appearing margins of resected intestine from patients with Crohn's disease. Half of the patients with immunoglobulin G values above 18 milligrams per gram of dry weight at the margins had recurrences at the suture line within three years. The immunoglobulin G concentrations do not correlate with steroid treatment, duration of symptoms, extent of disease, presence of epithelioid granulomas or previous recurrent disease. Immunoglobulin A and immunoglobulin M values are not helpful in predicting recurrences. Elevation of immunoglobulin G values at the resection margins appears to be a reliable indicator of early recurrence in patients with Crohn's disease.

Adolescent↗
PubMed1982

Granulomas do not affect postoperative recurrence rates in Crohn's disease.

Previous studies have reached disparate conclusions on the issue of whether or not granulomas confer any protection against recurrence of Crohn's disease after operation. In an attempt to resolve this controversy, we have examined postoperative recurrence rates in 102 patients with Crohn's disease. There were no differences in cumulative postoperative recurrence-free survival between the 53 patients with granulomas present in the resected specimens and the 49 patients without granulomas. It was concluded that the presence of granulomas in resected specimens of Crohn's disease exerts no independent influence on the rate of postoperative recurrence.

Crohn Disease↗
PubMed1981

Interplasmidic and intraplasmidic recombination in Escherichia coli K-12.

The construction of plasmids which facilitate the study of interplasmidic and intraplasmidic recombination is described. In this system, a single recombination event between two mutated Tcr genes on separate plasmids or on one plasmid leads to a change in the host phenotype from sensitivity to resistance to tetracycline. Recombination proficiencies have been determined for different E. coli K-12 strains: both interplasmidic and intraplasmidic recombination are independent of the recBC gene product. RecA mutations decrease the proficiency of plasmidic recombination 40 - 100 fold. Intraplasmidic and interplasmidic recombination via the recE pathway are more efficient than via the recBC pathway. Intraplasmidic recombination, but not interplasmidic recombination via the recE pathway is independent of a functional recA product.

Escherichia coli↗
PubMed1981

Effect of 2-mercaptoethanol on the haemagglutinating activity and antigenic properties of rubella virus.

Tween-ether treated rubella virus extract treated with 2-mercaptoethanol no longer haemagglutinates and its ability to combine with antibody is reduced although its sedimentation characteristics and the electrophoretic mobilities of the envelope glycoproteins are unaffected. The role of disulphide bonds in maintaining the structural and functional integrity of rubella virus is discussed.

Antigens, Viral↗
PubMed1981

Clinical correlates in hypertensive patients with left ventricular hypertrophy diagnosed with echocardiography.

Seventy-three hypertensive patients were evaluated with M mode and two dimensional echocardiography. Left ventricular hypertrophy was found in 37 patients (51 percent); 29 had concentric hypertrophy and the remaining 8 had disproportionate septal thickening. Factors that did not influence the distribution of patients in the group with left ventricular hypertrophy and normal subjects included (1) duration of hypertension, (2) level of blood pressure, (3) age, (4) body surface area, and (5) race. More of the patients who had a normal left ventricular mass (32 or 89 percent) than of those who had hypertrophy (22 or 59 percent) were receiving two or more antihypertensive drugs. Electrocardiography was very insensitive in identifying left ventricular hypertrophy in these patients. The presence of increased left ventricular mass was associated with a greater incidence of other target organ disease.

Adrenergic beta-Antagonists↗
PubMed1981

Response to long-term deferoxamine therapy in thalassemia.

We evaluated decreasing deferoxamine-induced urinary iron excretion during intensive chelation therapy in four children with thalassemia. Patients received daily intramuscular or subcutaneous therapy as well as intermittent intravenous infusions of high doses of DFO. Iron excretion fell by more than 80% in three patients and decreased by 45% in the fourth. Ferritin concentrations returned to normal or near normal values in all patients. Serum iron concentration and transferrin saturation steadily declined in one of four patients. Supplemental vitamin C was no longer required for normal vitamin C stores or maximum iron excretion in one patient after 26 months of chelation therapy. Interruption of chelation therapy was not followed by increased iron excretion after resumption of treatment with DFO. Decreasing DFO-induced iron excretion occurs during long-term, intensive chelation therapy, and may be the result of substantial reduction of excessive iron stores rather than of tachyphylaxis or transient depletion of an intracellular chelatable iron pool.

Adolescent↗