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Biomedical subjects

R Friedman

Publications and source records attributed to R Friedman.

At least 163 records · Page 9Linked to original sources
PubMed1985

Polyamines and Root Formation in Mung Bean Hypocotyl Cuttings : II. Incorporation of Precursors into Polyamines.

The incorporation of [(14)C]arginine and [(14)C]ornithine into various polyamines was studied in mung bean (Vigna radiata [L.] Wilczek) hypocotyl cuttings with respect to the effect of indole-3-butyric acid on adventitious root formation.Both [(14)C]arginine and [(14)C]ornithine are rapidly incorporated into putrescine, spermidine, and spermine, with similar kinetics, during 5- to 24-hour incubation periods. The incorporation of arginine into putrescine is generally higher than that of ornithine. The biosynthesis of putrescine and spermidine from the precursors, in the hypocotyls, is closely related to the pattern of root formation: a first peak at 0 to 24 hours corresponding to the period of root primordia development, and a second peak of putrescine biosynthesis at 48 to 72 hours corresponding to root growth and elongation. Indole-3-butyric acid considerably enhances putrescine biosynthesis in both phases, resulting in an increase of the putrescine/spermidine ratio.It is concluded that the promotive effect of indole-3-butyric acid on putrescine biosynthesis, from both arginine and ornithine, supports the hypothesis that auxin-induced root formation may require the promotion of polyamine biosynthesis.

Journal Article↗
PubMed1985

Survey of the age structure of "age-relevant" articles in four general medical journals.

The authors analyzed clinical research articles (1980 to 1982) in four general medical journals: New England Journal of Medicine, Annals of Internal Medicine, Journal of the American Medical Association, and British Medical Journal. Of the 1943 articles surveyed, 38.2% were judged to be clinically "relevant" to the elderly. "Relevant" articles were further analyzed to determine whether they contained enough older subjects to enable the reader to draw any inferences about the particular disease or diagnostic or treatment modality studied. Criteria for "age sufficiency" included: mean age of study group (means) greater than or equal to 60 years; if means was less than 60 years, two SD or the range included at least one patient aged 70 years; and greater than or equal to 20% of the study group was older than 60 years. Overall, slightly more than 50% of clinically relevant articles had too few older subjects by the authors' quite liberal age criteria. No statistically significant differences were found among the four journals. Of the age-relevant articles, 25.5% had a mean age of sample studied of greater than or equal to 60 years, 10.9% of greater than or equal to 65 years, 5.6% of greater than or equal to 70 years, and 2.3% of greater than or equal to 75 years. The average age of all subjects studied for three conditions commonly found among the elderly was calculated: coronary artery disease (51.7 years); hypertension (49.8 years); and cancer (52.9 years). The authors concluded that many of the original articles of these four journals did not include (for 1980 to 1982) enough older subjects in their study samples to enable readers to draw any valid inferences about the older population itself.

Adult↗
PubMed1985

Making family therapy easier for the therapist: burnout prevention.

Burnout prevention for family therapists can be enhanced by careful consideration of the degree of responsibility taken by the therapist contrasted with responsibility placed on the family. Attention to issues of expectations, role definition, sharing of feelings, and therapeutic ambition can ease the strain on the therapist.

Burnout, Professional↗
PubMed1985

Large-scale reductions in speeding and accidents in Canada and Israel: a behavioral ecological perspective.

We assessed the effects of posted feedback and warning ticket programs on speeding and accidents in two cities. In Experiment 1, speeding feedback signs were effective even when 10 were used in Dartmouth, Nova Scotia, and reductions in speeding were associated with reductions in accidents. The effectiveness of the signs was correlated with the number of intersections and residences within 0.5 km beyond them, and the signs had no effect on untreated streets. In Experiment 2, posted feedback and a warning program reduced speeding and accidents on 14 streets in Haifa, Israel.

Accidents, Traffic↗
PubMed1985

Student perception of faculty role models.

Few studies have been conducted on the effect of faculty role models on dental students. Questionnaires were developed to compare faculty self-perceptions with dental students' perceptions of the role they desired to achieve. Results indicated a minimal relationship between the self-perceptions of faculty and the students' identification of their desired future role in the dental profession. Furthermore, faculty were not perceived by students as being the most influential in molding their feelings about the practice of dentistry.

Consultants↗
PubMed1985

Blood level of C3 complement component as an aid in the management of acute phase glomerulonephritis.

Ninety-five patients with acute glomerulonephritis, based upon clearly defined pathological criteria, were studied and scored. The scoring was correlated to their levels of blood complement components. Patients with low C3 serum levels had a severe course during the acute phase of their disease, as compared with those with normal C3 serum levels. No such correlation was established with regard to C4 serum levels. It is suggested that C3 serum level may serve as an indicator of the expected severity of the inflammatory process and thus as an aid in the management of patients with acute glomerulonephritis in the initial phase of the disease.

Acute Disease↗
PubMed1984

Preparation, characterization, and use of an antiserum specific for 2',5'-oligoadenylates.

Periodate-oxidized ppp(A2'p)3A was coupled in high yield to an acyl hydrazide derivative of bovine serum albumin and the conjugate was used to immunize rabbits. Several potent and specific antisera were obtained, and one was tested extensively. Fifty per cent of the bound probe ppp(A2'p)3A3'[32P]pCp was displaced by compounds containing the moiety -pA2'pA-at concentrations of 20-60 nM and by compounds containing the moiety -p(A2'p)2A- at 1 nM. The 3',5'-oligoadenylate (A3'p)3A was bound more than 10,000 times less tightly than (A2'p)3A. The antiserum can be used in competition assays in which the amount of an antibody-probe complex is measured after binding to Millipore filters or to polystyrene beads. These assays allow the clear detection of as little as 20 fmol (20 microliters of 1 nM) of 2',5'-oligoadenylates.

Adenine Nucleotides↗
PubMed1984

Eustachian tube obstruction after provocative nasal antigen challenge.

To test if allergic rhinitis is associated with abnormal eustachian tube function (ET), juvenile rhesus monkeys were passively sensitized with serum samples from patients allergic to timothy grass or ragweed pollen. Tympanostomy tubes were inserted for direct measurement of ET function by inflation-deflation and forced-response testing before and after provocative intranasal challenge. Intranasal challenge with pollen (antigen) resulted in rhinorrhea and nasal obstruction. Slight increases in passive ET function values and significantly impaired active ET function were observed after antigen challenge. No changes in nasal airway patency or active ET function resulted from control nonantigen pollen challenges. These data complement our studies in man and support the use of this model to evaluate the relationships among allergic rhinitis, ET function and middle ear disease.

Adult↗
PubMed1984

Asthma and bacterial sinusitis in children.

Signs, symptoms, and radiographic abnormalities of sinusitis are frequent in children with asthma; it is not known whether sinus inflammation is associated with bacterial infection or other mechanisms. Eight asthmatic patients with exacerbation of asthma despite bronchodilator therapy were studied after maxillary sinusitis was confirmed by radiographs. All had cough, wheezing, nasal stuffiness, rhinorrhea and were afebrile. Four patients had headaches, and two had facial pain. Maxillary sinus aspirates were obtained, and bacterial cultures were positive in five: Branhamella catarrhalis (2), nontypeable Hemophilus influenzae (2), Streptococcus pneumoniae (1). Nose and throat cultures did not correlate with sinus cultures. All patients received bronchodilators, and four of eight patients received steroids. All were treated for 14 to 28 days with antibiotics during which seven of the eight patients improved clinically including all with positive sinus cultures. Asthma-symptoms diary scores were kept by five; all demonstrated improvement. Pulmonary-function tests improved in five of seven patients after the antibiotic and asthma therapy including the four patients with positive cultures. Sinus radiographs cleared in three, improved in three, and were unchanged in two patients after antibiotic therapy.

Anti-Bacterial Agents↗
PubMed1984

Genetic predisposition to hypertension, elevated blood pressure and pain sensitivity: a functional analysis.

Pain sensitivity was examined in Dahl hypertension-sensitive (DS) and Dahl hypertension-resistant (DR) rats. The results indicated that hypertensive DS rats had a reduced sensitivity to painful stimulation compared to normotensive DS rats or compared to DR rats. Furthermore, the lower pain sensitivity of even normotensive DS vis-a-vis normotensive DR rats was not due to genetic factors but due to slight variations in blood pressure between lines. These results provide additional experimental support for the contention that elevations in blood pressure result in decreased pain sensitivity.

Animals↗
PubMed1984

Alpha 1- and alpha 2-adrenoceptor binding in the Dahl rat model of hypertension.

Dahl sensitive rats on a high salt diet (DSH group) developed significant elevations in blood pressure (BP). Sensitive rats maintained on a low salt diet (DSL group) and Dahl resistant rats on a high or low salt diet (DRH and DRL groups, respectively) remained normotensive. The DSH and DRH groups displayed a lower density of alpha 2-adrenoceptors (as measured with [3H]-clonidine) in the cerebral cortex than normotensive DSL and DRL groups. In contrast, the density of alpha 2-adrenoceptors in the medulla was significantly lower in the DSH group than the DSL group, but significantly higher in the DRH group compared to the DRL group. The density of alpha 1-adrenoceptors (as measured with [3H]-WB4101) in the hypothalamus was lower in the DSH group than the DSL group but greater in the DRH group than the DRL group. The results suggest that the sensitive and resistant lines can be distinguished by the density of alpha 1- adrenoceptors in the hypothalamus and medulla, respectively. The interactive effects of dietary NaCl and susceptibility to hypertension on adrenoceptors lend further support to the hypothesis that the genetic predisposition to hypertension is associated with a disruption in central adrenergic activity.

Adrenergic alpha-Antagonists↗
PubMed1984

Myocardial cholinergic receptor sites and enzyme activity in the Dahl model of essential hypertension.

The density of muscarinic receptor sites, choline acetyltransferase (ChAT), and acetylcholinesterase (AChE) activity in the myocardium of the Dahl salt-sensitive (DS) and salt-resistant (DR) rat was investigated. Both normotensive and hypertensive (as a result of 8.0% NaCl added to the diet) DS rats displayed a lower concentration of muscarinic receptors and less ChAT and AChE activity in myocardial tissue than normotensive DR rats. Lower receptor site density and enzyme activity in the myocardial of the DS line may reflect decreased vagal tone. If true, this may produce dificits in the ability to appropriately adjust heart rate (HR) in response to elevations in blood pressure (BP). Therefore, the present results may be viewed as exacerbational factors in the pathogenesis of hypertension in the DS line.

Acetylcholinesterase↗
PubMed1984

Patterns of fibronectin deposition in normal and neoplastic fibroblasts and mammary tissue.

Deposition of fibronectin (FN) was studied by indirect immunofluorescent staining, employing monospecific rabbit anti-human FN antibody, in the following 3 systems: cultures of cells derived from Rous sarcomas of chickens and of normal chick fibroblasts; frozen sections of chicken Rous sarcomas; and frozen sections of mouse and human mammary tissue, normal and neoplastic. The normal fibroblasts produced a well-oriented, delicate, fibrillar FN network. The sarcoma cells in culture also formed a FN-positive matrix, but one very different in appearance, consisting of coarse, unoriented strands. FN was also present abundantly between the cells of the sarcomas in vivo. In normal mammary tissue, FN was localized predominantly in the basal lamina region, well delineated from the surrounding FN-reactive stroma. The epithelial cells were generally, but not always, FN-negative. In apparently normal tissue areas of the breasts of mammary carcinoma patients, epithelial cells with highly reactive cell peripheries were frequently seen; the stroma surrounding the positive cells was often poor in FN and the basal lamina region lacked the substance. Mammary carcinoma cells were almost always negative, but it was characteristic of these tumours that the surrounding stroma displayed FN richly.

Animals↗
PubMed1983

Hypogammaglobulinemia with sarcoidlike granulomas.

A 12-year-old girl had sarcoidlike syndrome and hypogammaglobulinemia. Pancytopenia and hepatosplenomegaly were noted at age 4 years. Histopathologic study showed typical sarcoidlike granulomas. Chronic lung disease, along with recurrent infections, developed. Immunologic studies revealed common variable hypogammaglobulinemia, abnormal cellular immune functions, and decreased C4 levels. An immunoregulatory defect is suggested as the pathogenesis of this immunodeficiency syndrome, with multisystem sarcoidlike granulomas, hypersplenism, pulmonary disease, and abnormal cellular and humoral immunity.

Agammaglobulinemia↗