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Biomedical subjects

L Meyer

Publications and source records attributed to L Meyer.

At least 199 records · Page 11Linked to original sources
PubMed1990

Isolation and characterization of a structural subunit from the core light-harvesting complex of Rhodobacter sphaeroides 2.4.1 and puc705-BA.

A method for isolating a structural subunit, B825, from the B875 core light-harvesting complex (LHC) of Rhodobacter sphaeroides 2.4.1 (wild-type) and a B800-B850(-) mutant, puc705-BA, is presented. This method, based on one developed to prepare a similar subunit, B820, from the core LHC of Rhodospirillum rubrum [Miller et al., Biochemistry 26, 5055-5062 (1987)], requires the dissociation of treated chromatophores with the detergent, octyl-glucoside. A subsequent gel filtration step separates B800-850 (if present), reaction centers, and free bacteriochlorophyll from the subunit complex. B825 was quantitatively reassociated into an 873 nm absorbing form which resembled the in vivo complex as judged by its absorption properties. The polypeptides in B825 and B800-850 were isolated by HPLC and identified by N-terminal amino acid sequencing. Two polypeptides, alpha and beta, were found in each complex in a 1:1 ratio. The spectral and biochemical properties of the subunits isolated from Rhodospirillum rubrum, Rhodobacter sphaeroides, and Rhodobacter capsulatus are compared.

Bacterial Proteins↗
PubMed1990

Comparison of aerosolized glycopyrrolate and metaproterenol in acute asthma.

The efficacy of nebulized glycopyrrolate compared with metaproterenol was evaluated in 46 patients with acute asthma. In a double-blinded, randomized fashion, patients received, as sole therapy, either 2 mg of glycopyrrolate or 15 mg of metaproterenol every 2 h over a 6-h study period. Of the 35 patients completing the study, analysis of variance demonstrated no difference in percentage of change in FEV1 between glycopyrrolate and metaproterenol. Two hours after the initial dose, there was a 30 percent increase in FEV1 for glycopyrrolate compared with a 25 percent increase for metaproterenol (p greater than 0.05, NS). In contrast to the comparable bronchodilator activity, the side effects profile of the two agents were markedly dissimilar. Not only were subjective complaints of tremor, palpitations, and paresthesias increased for metaproterenol, but the heart rate response was significantly elevated (p less than 0.05) compared with glycopyrrolate. Based on these data, administration of the aerosolized anticholinergic agent, glycopyrrolate, is a reasonable therapeutic alternative for acute asthma.

Administration, Inhalation↗
PubMed1990

cDNA-cloning and expression of VP1-specific sequences of foot-and-mouth disease virus types A5 and O1.

The RNA genome of foot- and mouth disease virus strains A5 Westerwald and O1 Lausanne has been reverse-transcribed and cloned in lambdaphages or plasmids. Identification of cDNA-clones containing VP1-specific sequences was achieved by hybridization, restriction mapping, and sequence analysis. VP1-coding cDNA-fragments were subcloned into the expression vector pEX which led to synthesis of fusion proteins with beta-galactosidase. These fusion proteins reacted with anti-VP1 antibodies on a Western blot, but were not capable of inducing neutralizing antibodies to mice. This seemed to suggest a tertiary structure of the VP1-epitopes unlike those of native VP1. Other attempts are discussed to construct VP1-fusion proteins folding similarly to the native viral protein structure.

Amino Acid Sequence↗
PubMed1989

Calculating radiation absorbed dose for pheochromocytoma tumors in 131-I MIBG therapy.

A protocol for calculating radiation absorbed dose to pheochromocytoma tumors during treatment with 131I-labeled metaiodobenzylguanidine (MIBG) is described. The technique calls for (a) obtaining tumor volumes from Computed Tomography and/or Magnetic Resonance Imaging, (b) computing energy absorbed by assuming complete beta-particle absorption and a standard shape for gamma-ray absorption and (c) scaling from tracer to therapy dose rate by the ratio of administered activities. Also a 131I time-activity curve is obtained from planar, Anger-camera, conjugate-view images of the tumor and a known-strength source, both over a series of days. In addition, to correct for any systematic errors in the calculated uptakes, a larger activity of 123I MIBG is administered separately and quantitative Single Photon Emission Computed Tomography (SPECT) is undertaken. A known-strength source also undergoes SPECT to calibrate the tomograms. Correction for Compton scattering is accomplished by the dual-energy-window technique. The subtraction fraction was found to be 0.7 for the 1/2" crystal camera and the mean reduction in tumor counts for seven tumors from Compton correction was 0.76. The normalization factor needed to bring the conjugate-view activities into agreement with the SPECT values ranged from 0.74 to 1.06. A test study on an anthropomorphic phantom indicated that the error in resultant activities might be estimated as +/- 13%. Application of the protocol led to the calculation of real, or potential (when decision was finally made to not administer therapy) radiation absorbed dose to seven tumors in three patients from an administration of about 8 GBq of MIBG. For two metastatic tumors in a 19-year old patient who did not have her primary cancer resected, the calculated radiation absorbed dose was 170 and 180 Gy. For the four metastatic deposits evaluated in two older patients, both of whom had their primary tumor surgically removed, the values ranged from 18 to 31 Gy.

3-Iodobenzylguanidine↗
PubMed1989

[Fertility and Turner mosaicism syndrome].

Six patients with a Turner mosaicism are reported. All six women were investigated for sterility or infertility. Four of six patients had a total of nine pregnancies: six abortions, one stillbirth, two normal children. The literature contains reports of 17 pregnancies in 10 women with 45.X karyotype and 106 pregnancies in 48 women with mosaicism. Miscarriages, stillbirths and malformations were common. These women need special counselling and in case of a pregnancy amniocentesis is indicated. We discuss the pathogenesis of reduced fertility with Turner patients and explain the problems related to the cystogenetic diagnosis of the Turner-Mosaic Syndrome.

Abortion, Spontaneous↗
PubMed1989

Long-term psychological sequelae of mastectomy and breast conserving treatment for breast cancer.

Psychiatric and psychosocial adaptation to two types of treatment for primary breast cancer, modified radical mastectomy and partial mastectomy with radiotherapy, was studied five years after the primary treatment. 102 consecutive patients with pT1NOMO breast cancer were invited to follow-up which was done by standardized questionnaires. Nineteen women declined the invitation and 25 others were not included for various reasons, leaving 58 to complete the interviews. 30% of the women reported accentuated mental symptoms compared to the state before treatment, with no significant difference between the two treatment groups. Psychiatric state, marital adjustment and fear of cancer recurrence were also similar in the two groups. However, breast conserving treatment seems to preserve the woman's female identity and acceptance of body configuration. We conclude that breast conservation does not in itself prevent mental sequelae after treatment for primary breast cancer. Selective psychoprophylactic programs and reorganization of the postoperative follow-up should be tried to diminish unwanted psychological reactions.

Body Image↗
PubMed1989

[Breast stimulation for labor induction in a stress test].

We performed 100 nipple stimulations for a contraction stress test at the Women's Hospital of the University of Basel. The stimulation was done unilaterally with a breast pump; each nipple was stimulated for 15 min. 33 of 100 patients had three or more contractions in 10 min (successful test), 60 of 100 patients had two or more contractions; 12 women had no contractions. Prestimulation contractions have an influence on the success rate. 50% of patients in the group with prestimulation contractions and only 26% in the group without prestimulation contractions had a successful test. The acceptance was good.

Adult↗
PubMed1988

Acute effect of various doses of isosorbide-5-mononitrate on hemodynamic and exercise performance in coronary artery disease.

The optimal dose of nitrates is still controversial, as chronic usage of too high a dose may result in a decrease in vascular response. The dose should be determined to reduce preload acutely, and not to decrease the activity during chronic therapy. To determine this dose, 50 patients with angiographically confirmed coronary artery disease were studied. The effects on heart rate and mean systemic and pulmonary arterial pressures at rest and during exercise, and work capacity and duration were measured. The patients were classified into 5 groups, receiving placebo or isosorbide-5-mononitrate, 5, 10, 20 and 50 mg, respectively, as a single oral dose. Placebo had no effect on the measured parameters. All doses of isosorbide-5-mononitrate reduced mean pulmonary arterial pressure: 10 mg--by 16% at rest and 24% during exercise; 20 mg--24% and 34%, respectively (a near maximal effect); and 50 mg--27% and 38%. Similar results were found also for work capacity: 10 mg increased work capacity by 33%; 20 mg--79%; and 50 mg--56%. Thus, the therapeutically optimal single dose is about 20 mg. Higher doses produce no additional benefit and increase the risk for tolerance development.

Adult↗
PubMed1988

The prevention of sexually transmitted diseases which affect fertility: methodological problems and initial results.

Sexually transmitted diseases and their consequences for fertility are currently a major preoccupation in public health. A joint research project is being carried out in France to develop an STD prevention program and then to implement it experimentally to evaluate its efficiency. It includes 2 phases: a feasibility phase, currently concluded, and an active phase, a community randomized trial. The aim of the feasibility phase was to test the research methods and tools and to act as a basis for the design of the prevention program. It measured the incidence of discharge (men and women) at a one-year interval and patient characteristics. Participating physicians were GPs in a French administrative department near Paris. Between the two measurements, information and sensitization actions were carried out in the same department among health professionals and the general public. The results show that the incidence of discharge (chosen here as indicators of STDs) in daily general medical practice is low, of the order of 6 cases per 1000 consultations. The community randomized trial will now be conducted in 6 French administrative departments, randomly divided into 3 treated departments, benefiting from a prevention campaign, and 3 controls, where no actions will be undertaken, and its results will be used in a national STD prevention campaign.

Adult↗
PubMed1988

Secular trend in the rate of small-for-gestational-age infants: Haguenau Study 1971-1985.

Between 1971 and 1985, at the Haguenau Maternity Hospital, a 20% decrease was observed in the rate of small-for-gestational-age infants (birthweight less than 10th centile using figures from all the study births) among 20,101 births between 28 and 42 weeks. This decrease could not be explained by simultaneous changes in socio-demographic and anthropometric characteristics of the pregnant women, nor a recruitment bias. The earliness of prenatal care at the Maternity Hospital may have played a role in the downward trend. Further research is needed to confirm the influence of prenatal care on the rate of small-for-gestational-age babies.

Adult↗
PubMed1988

Daily decision-making in community residences: a social comparison of adults with and without mental retardation.

In addition to physical placement in the community, the extent to which individuals experience personal autonomy may provide a crucial measure of the attainment of a more normalized lifestyle. Everyday choices and choice-making opportunities of 24 persons with mental retardation living in community group homes were compared to choices of 42 nonretarded adults. The adults with mental retardation had significantly fewer opportunities to make decisions on such matters as what to eat or wear, how to spend free time, and with whom to live. Results were discussed in terms of the need to operationalize meaningful improvements in the lives of persons with mental retardation that go beyond the appearance of the physical environment.

Activities of Daily Living↗
PubMed1987

Acute and chronic effects of molsidomine on pulmonary artery pressure and work capacity in patients with coronary heart disease.

To test the clinically supposed development of tolerance during chronic molsidomine therapy we studied a total of 11 patients with angiographically-proven coronary heart disease at rest and during ergometric exercise (supine position; submaximal, i.e. 50 W for 3 min, and maximal exercise). Pulmonary arterial pressure (PAPmean, floating catheter), arterial blood pressure (RR, cuff method), work capacity (W x min) and duration of exercise loading (sec) were measured at rest and on exercise before and during chronic (4 weeks) oral therapy with 3 x 4 mg day-1 of molsidomine. Acute administration of 4 mg molsidomine reduced the mean arterial resting pressure by 12% and under submaximal exercise loading by 8%. After molsidomine, the PAPmean was reduced by 35% at rest; following a period of treatment of 4 weeks no significant decrease in efficacy could be discerned (PAPmean reduction by 31%). Under submaximal and maximal exercise the PAPmean dropped by 44% and 37%, respectively (35.5 +/- 6.7 cf. 19.9 +/- 4.5 mmHg; 39.2 +/- 6.5 cf. 24.8 +/- 7.0 mmHg), whilst simultaneously the work capacity increased by 93% (281 +/- 108 cf. 545 +/- 254 W x min). After 4 weeks treatment with 12 mg day-1 of molsidomine, the PAPmean of 22.4 +/- 6.6 mmHg and 30.1 +/- 9.9 mmHg under identical exercise loading conditions, remained significantly below the exercise load value prior to the onset of medication. The molsidomine-induced increase in the exercise tolerance was maintained throughout the long-term medication (537 +/- 268 W x min). With a four-week treatment with daily doses of molsidomine there was a persistent effect on the pulmonary arterial pressure and the work capacity. Thus development of tolerance during high dose, long-term molsidomine therapy is not to be expected.

Adult↗
PubMed1987

Psychiatric and psychosocial characteristics of patients accepted for rhinoplasty.

Sixty-four patients undergoing rhinoplasty, consecutively admitted to and operated upon at the Department of Plastic and Reconstructive Surgery, Malmö General Hospital, Sweden, were studied with regard to their medical history, personality, and psychosocial and psychiatric characteristics. Forty patients with a history of nose trauma were compared with 24 patients without such history. The aim of the study was to describe and evaluate background factors, with special regard to psychosocial characteristics that might possibly affect the outcome of rhinoplastic surgery. The trauma patients predominantly described themselves as sthenic, outgoing, self-reliant, insensitive to the opinions of others, and as individuals with a low degree of self-criticism. Their consumption of alcohol was fairly high, and they were often exposed to the risk of accidents with bodily injuries. Their major motive for rhinoplasty was to improve nose breathing. The nontrauma patients were characterized by various symptoms of psychoneurosis and somatic signs of anxiety. Their sensitivity was related to their appearance, and the major motive for rhinoplasty was to become less socially inhibited and to develop their personalities. An inverted factor analysis generally demonstrated that the two groups of patients could be recognized when common response patterns in the preoperative interview formed the basis for the categorization. The psychopathological mechanisms and anticipated adaptation after rhinoplasty are discussed for the two groups of patients.

Adult↗
PubMed1987

Maternal and neonatal morbidity in instrumental deliveries with the Kobayashi vacuum extractor and low forceps.

Risks to the mother and newborn associated with the use of the Kobayashi Silastic vacuum extractor (n = 293) were compared with those associated with the use of low forceps (n = 468) in a retrospective chart review. Third or fourth degree perineal tears and vaginal and cervical lacerations were all observed less frequently among women delivered with the vacuum extractor. The need for post-partum bladder catheterization was also reduced for these women. Babies born by the means of the vacuum extractor ran an increased risk of cephalhematoma and neonatal jaundice. No difference in major neonatal morbidity was observed between the two groups. The Kobayashi instrument appears to be a useful alternative to forceps in low vaginal instrumental deliveries.

Birth Injuries↗