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Biomedical subjects

J Berlin

Publications and source records attributed to J Berlin.

72 records · Page 4Linked to original sources
PubMed1979

5-Methyltryptophan resistant cells of Catharanthus roseus.

Several cell lines resistant to 5-methyltryptophan were selected from wild type cells of different Catharanthus roseus suspension cultures. The resistant cells had up to 30 times the normal levels of free tryptophan. Despite the increased pool size of tryptophan anthranilate synthetase activity of resistant cells was as sensitive to inhibition by L-tryptophan as wild type cells. The overproduction of tryptophan did not lead to intensified accumulation of tryptamine nor of indole alkaloids. This was supported by a low conversion of tryptophan to tryptamine in vivo and in vitro. The overproduction of one of the primary precursors was evidently not sufficient to stimulate the rate of indole alkaloid synthesis in Catharanthus cells.

Anthranilate Synthase↗
PubMed1977

Elective hysterectomy.

Hysterectomy is the most frequently performed major operation. Its frequency is increasing due to greater use of elective indications such as uterine cancer prophylaxis, contraception, and menopausal problems. The effects of elective simple hysterectomy are evaluated in terms of morbidity and mortality rates and costs. Among 35-year-old women operated upon, the average over-all gain in life expectancy is only 0.2 years. This is due to the saving of 1.3 per cent of women who would have died from cancer of the cervix or endometrium; they gained 14.3 years of life. In addition, 3 per cent of women are spared the development of and treatment for these two conditions. All women operated upon would be relieved of some undesirable aspects of the menopausal years such as irregular uterine bleeding. There are also economic gains. However, the operation has adverse health effects which could offset any gains from cancer prevention. In addition, each year of life saved would cost about $12,800 and most of the added years would be lived in old age. Delaying the operation to age 45 and including oophorectomy would result in a lower cost per year of life saved-about $9,800-but the risk of adverse health effects probably would be increased very much. Cancer prophylaxis cannot justify elective hysterectomy; we cannot assess whether quality-of-life considerations do.

Adult↗
PubMed1977

Correlation between Phenylalanine Ammonia Lyase Activity and Phenolic Biosynthesis in p-Fluorophenylalanine-sensitive and -resistant Tobacco and Carrot Tissue Cultures.

Phenylalanine ammonia lyase (PAL) activity was measured in p-fluorophenylalanine (PFP)-sensitive and -resistant tobacco (Nicotiana tabacum L.) and carrot (Daucus carota L.) cell lines which are known to oversynthesize phenylalanine. A correlation between phenolic levels and PAL activities was detected. The phenylalanine analog-resistant and -sensitive carrot cells showed no differences in the accumulation of phenolic compounds and PAL activities. The PFP-resistant tobacco cells, however, had 10 times higher levels of phenolics and also 10 to 20 times higher PAL activities than the PFP-sensitive line. The PAL activity in the resistant tobacco line increased dramatically after inoculation of the cells into fresh medium. Conditions affecting this increase were characterized.A comparison of the responses of PAL activity to light treatment and changes in the 2,4-dichlorophenoxyacetic acid concentration in the medium revealed no differences for both tobacco lines. After inoculation of the cells into fresh medium, the rates of nitrate uptake from the medium were similar for both lines as were the rates of protein synthesis. The reason for the increased PAL levels in the resistant tobacco cells remains unknown.

Journal Article↗
PubMed1977

An epidemic of pediculosis capitis.

An epidemic due to Pediculus humanus capitis occurred in the public schools of Buffalo, New York, in the winter of 1973. A survey at one elementary school showed that 20% of whites and no blacks were infested, and a city-wide prevalence survey during the academic year September 1972 to May 1973 showed that 7.2% of all pupils were infested. An epidemiological investigation showed that sex, age, race, socioeconomic status, crowding, method of closeting garments, and family size influenced the distribution of pediculosis but that hair length apparently was not a factor. Poverty and ignorance appeared to contribute to the persistence of infestation.

Adolescent↗
PubMedDate not supplied

Roentgenographic assessment of acromial morphologic condition in rotator cuff impingement syndrome.

Patients with an isolated diagnosis of rotator cuff impingement syndrome were prospectively entered into the study. Each of the 23 subjects was refractory to conservative therapy, had preoperative roentgenograms, and underwent an open acromioplasty. The roentgenograms included anteroposterior, axillary, 30 degrees caudal tilt, and supraspinatus outlet views. The roentgenograms were measured by four independent readers. The separate views were then scored for reliability, and the correlation of the measurements with intraoperative acromial measurements was assessed. Interobserver reliability was highest for the caudal tilt view (0.84) and lowest for the axillary view (0.09). The supraspinatus and caudal tilt views correlated significantly with distinct intraoperative measurements of acromial spur size. We continue to advocate the evaluation of both views for preoperative assessment of the acromial spur in the rotator cuff impingement syndrome.

Acromion↗
PubMedDate not supplied

Formation of beta-peltatin-A methyl ether and coniferin by root cultures of Linum flavum.

Extracts of root cultures of Linum flavum contained high cytotoxic activity due to the presence of 1% beta-peltatin-A methyl ether of the dry mass. During chromatographic analysis of the cell extracts, coniferin was identified as the major uv-absorbing but noncytotoxic constituent with levels of up to 3% of the dry mass. Growth, culture appearance, and product accumulation varied greatly with the 2,4-D concentration in the medium.

2,4-Dichlorophenoxyacetic Acid↗
PubMedDate not supplied

Symptom reports from a cohort of African American and white women in the late reproductive years.

OBJECTIVE: To identify symptoms experienced in a cohort of healthy women in the late reproductive years; to compare symptom reports between African American and Caucasian women; and to determine the extent to which other factors in reproductive health, mood and behavior, lifestyle, and demographic background are associated with the reported symptoms. DESIGN: A cohort of women aged 35 to 47 years (mean age, 41 years) was identified through random digit dialing. This study is a cross-sectional analysis of data collected at enrollment from a subset of 308 women who completed daily symptom reports (DSR) for one menstrual cycle. Data were obtained in structured interviews and self-administered standard questionnaires. The associations of the study variables with symptoms as assessed by the DSR were examined using analysis of variance and general linear models. RESULTS: The African American women were significantly more likely to report in interview that they experienced menopausal symptoms (46% vs. 30%; p < 0.001) and had significantly higher ratings on the physiological symptom factor of the DSR, which included hot flashes, dizziness, poor coordination/clumsiness, urine leaks, and vaginal dryness. The DSR yielded two other factors of psychological and somatic symptoms. Race was associated only with the physiological symptom factor in the multivariable analyses. Neither race nor age were associated with psychological symptoms, which were predicted by current or past mood problems. CONCLUSIONS: Symptoms commonly associated with the menopause are experienced in the late reproductive years before observable changes in menstrual cycles. African American women reported more physiological symptoms than white women. These data provide an essential baseline for longitudinal study of symptoms associated with the ovarian decline in the perimenopausal years.

Adult↗
PubMedDate not supplied

Oxidative decarboxylation of para-hydroxybenzoic acids by peroxidases under in vivo and in vitro conditions.

Oxidative decarbyxylation of p-hydroxybenzoic acids in plant cell suspension cultures is catalyzed by peroxidases. This reaction has been characterized in vivo and in vitro. Decarboxylation of substituted benzoic acids yields monomeric, dimeric and oligomeric benzoquinones. All peroxidases obtained from soybean (Glycine max) cell suspension cultures by gel electrophoresis are equally capable to decarboxylate p-hydroxygenzoic acids as indicated by their rather low differences in specific activity for various benzoic acids.

Decarboxylation↗
PubMedDate not supplied

Amino acid uptake by amino acid analog resistant tobacco cell lines.

Two tobacco cell lines resistant to p-fluorophenylalanine (PFP) and one resistant to 5-methyltryptophan (5-MT) are compared with wild type cells in their ability to absorb amino acids from the medium. One p-fluorophenylalanine-resistant cell line shows greatly reduced uptake of all amino acids so is resistant to growth inhibition by other amino acid analogs. The impaired absorption is noted with amino acids, amino acid analogs and shikimate, but not with cinnamate, salicylate, nicotine, glucose, 3-O-methylglucose and palmitate. The phenylalanine transport system of the PFP-resistant cell line and the wild type both have Km values of 90 micrograms, but have different Vmax values. Several analogs of phenylalanine and several neutral L-amino acids inihibt the phenylalanine transport system, while L-aspartic acid, L-arginine, D-phenylalanine or chlorogenic acid do not interfere with the L-phenylalanine uptake. The results indicate the presence of more than one transport system for amino acid uptake. The lessened uptake of all amino acids, the specificity of the uptake systems and the unchanged binding let us conclude that a pleiotropic mutation or that some inhibitor causes the reduced uptake of all amino acids by the PFP-resistant cell line.

Amino Acids↗
PubMedDate not supplied

Evidence for distinct amino acid transport systems in cultured tobacco cells.

It is shown by competition experiments that tobacco cell lines have distinct transport systems for L-amino acids. For all tested amino acids the Lineweaver-Burk plots were diphasic indicating the presence of more than one carrier for any one amino acid. Moreover distinct transport systems for neutral, acidic and basic amino acids were kinetically characterized. Based on competition experiments neutral amino acids were absorbed by all transport systems. Aspartic acid entered the cells via its own carrier and via the basic carrier while arginine was taken up only by the basic carrier. Neutral amino acids such as L-leucine or L-phenylalanine were taken up faster than acidic or basic amino acids.

Alanine↗
PubMedDate not supplied

Effects of alpha-aminooxy-beta-phenylpropionic acid on phenylalanine metabolism in p-fluorophenylalanine sensitive and resistant tobacco cells.

A p-fluorophenylalanine (PFP) resistant cell line with high phenylalanine ammonia lyase (PAL) activity and wild type cells with low PAL activity were compared in their responses to PAL inhibition by alpha-aminooxy-beta-phenylpropionic acid (AOP). Inhibition of PAL reduced the levels of the main phenolic compounds to 30% of the controls. Free phenylalanine pools increased 17 fold in the resistant line and 6 fold in the sensitive line, respectively. The accumulation of phenylalanine did not reduce the flow of labeled shikimic acid into the aromatic amino acids tyrosine and phenylalanine. The results are discussed with respect to the feedback inhibition of chorismate mutase activity by phenylalanine and tyrosine in both cell lines.

Ammonia-Lyases↗