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Biomedical subjects

F Meyer

Publications and source records attributed to F Meyer.

At least 19 recordsLinked to original sources
PubMed1992

Pheromone 4 gene of Euplotes octocarinatus.

We have cloned and sequenced a 1.7 kb macronuclear chromosome encoding the pheromone 4 gene of Euplotes octocarinatus. The sequence of the secreted pheromone is preceded by a 42 amino acid leader peptide, which ends with a lysine residue. The sequence coding for the leader peptide contains information for a putative signal peptide and is interrupted by a 772 bp intron as shown by comparison with a cDNA clone. A 64 bp intron and a 145 bp intron interrupt the sequence coding for the secreted pheromone. The three introns contain typical 5' and 3' splice junctions and a putative branch point site. The small introns have a low GC content. The large intron has a GC content similar to that of the pheromone 4 gene exons. The amino acid sequence of pheromone 4, deduced from both the genomic DNA and the cDNA of pheromone 4, shows that the secreted pheromone consists of 85 amino acids. One of its amino acids is encoded by a UGA codon. Since it has been shown for pheromone 3 of E. octocarinatus that UGA is translated as cysteine, it is assumed that the UGA codon encodes cysteine in pheromone 4 as well. The 164 bp noncoding region upstream of the leader peptide is AT-rich and contains an inverted repeat capable of forming a stem-loop structure with a stem of 11 bp. The 151 bp noncoding region at the 3' end of the chromosome contains a putative polyadenylation sequence and an inverted repeat. The macronuclear molecule is flanked by telomeres and carries the pentanucleotide motif TTGAA, located at a distance of 17 nucleotides from the telomeres. This motif has been suggested to be involved in the formation of macronuclear chromosomes.

Amino Acid Sequence↗
PubMed1992

Isolated rat pancreatic acini as a model to study the potential role of lipase in the pathogenesis of acinar cell destruction.

We have recently reported that lipase may play a role in the pathogenesis of acute pancreatitis by its ability to release fatty acids from triglycerides. The aim of this study was to further investigate the effect of lipase and its various digestive products on the integrity of isolated pancreatic rat acini. Pancreatic acini were prepared by collagenase digestion and their newly synthesized proteins labeled with 35S-methionine. Acini were later incubated in buffer to which various factors were added: Products of lipolytic digestion, such as various fatty acids and monoglycerides, fat tissue, nonactivated or trypsin activated homogenized pancreatic tissue, and a specific lipase inhibitor (THL, tetrahydrolipstatin). Cellular destruction was quantified by the degree of radiolabeled proteins released. Short chain fatty acids and monoglycerides (up to C-12) caused cellular destruction, whereas long chain fatty acids and their respective monoglycerides were not harmful. With regard to unsaturated fatty acids, long chain fatty acids (C-18 to C-22) were also able to destroy cells. The degree of cellular necrosis correlated with incubation time and fatty acid concentration. The cellular damage caused by incubation of acini with either inactive or trypsin activated pancreatic homogenates together with triglycerides could be completely inhibited by the specific lipase inhibitor THL. Bile alone caused no damage. When bile was combined with activated-pancreatic homogenates, about 25% of newly synthesized proteins were released by acini within 30 min. Incubation with a combination out of bile activated pancreatic homogenates and triglycerides resulted in the most pronounced damage. This acinar destruction could only be partly inhibited by THL. These studies suggest that both lipase and phospholipase-A2 may play an important role in the pathogenesis of acinar cell destruction.

Animals↗
PubMed1992

Comparison of different treatment modalities in experimental pancreatitis in rats.

Lipolytic enzymes may play a role in the pathogenesis of acute pancreatitis. Therefore, the effects of a lipase inhibitor, THL (tetrahydrolipstatin), a protease inhibitor, FUT (nafamostat mesilate), and albumin under different conditions in rats were investigated. (a) Isolated pancreatic acini were incubated with pancreatic homogenates and triglycerides or lecithin with or without albumin and the degree of cellular destruction quantitated. (b) Taurocholate was injected into the pancreatic duct of isolated pancreas and the organ continuously perfused with either FUT, THL, or albumin. Organ damage was evaluated by measurement of pancreatic enzymes in the portal effluence. (c) Necrotizing pancreatitis was induced in vivo via retrograde taurocholate injection. FUT, THL, or albumin was applied either intravenously or injected into the pancreatic parenchyma. (a) Albumin prevented the cellular damage caused by both fatty acids and lysolecithin. (b) THL was ineffective, FUT lowered the release of pancreatic enzymes into the portal effluence, and albumin was most effective. (c) Albumin prevented the development of panlobular necrosis and lowered the degree of extrapancreatic fat necrosis. Albumin, via its ability to bind detergents, may have therapeutic implications.

Albumins↗
PubMed1992

Geostatistical and morphological methods applied to three-dimensional microscopy.

Three-dimensional (3-D) images of osteocyte lacunae were examined on a confocal microscope. Both geostatistical and morphological processing techniques were used to improve and to analyse them. By a geostastical approach, this study aims at improving 3-D confocal images before any further image processing. Optimized linear filters, which take account of the second-order statistics and the 3-D structure of the data, allow for the removal of imperfections such as noise and/or blur due to the axial convolution, and interpolate voxels on a face-centred cubic grid from an initial cubic grid. An application of this technique to 3-D biological images is demonstrated. In a second step, a 3-D binary image is digitized and cleaned with 3-D morphological filters. The standard 3-D measurements cannot be applied in this case, since all osteocytes cut the border of the field. For this reason a 3-D Boolean model has been adjusted, from which it is possible to derive all useful information on the repartition and the morphology of the osteocytes.

Humans↗
PubMed1992

Double-blind, randomized, controlled trial of fish oil supplements in prevention of recurrence of stenosis after coronary angioplasty.

BACKGROUND: Previous studies suggest that recurrence of coronary stenosis after percutaneous transluminal coronary angioplasty (PTCA) might be prevented with dietary supplements rich in omega-3 fatty acids. The purpose of the present study was to evaluate this hypothesis. In addition, the relation between usual dietary consumption of omega-3 fatty acids and restenosis was assessed. METHODS AND RESULTS: A double-blind, randomized, controlled trial was conducted in which 205 patients undergoing a first PTCA received 15 capsules per day containing 1 g of either fish oil (2.7 g/day of eicosapentaenoic acid, 1.8 g/day of docosahexaenoic acid) or olive oil. The treatment was started 3 weeks before PTCA and continued for 6 months thereafter. Dietary intake was assessed by food frequency questionnaire. At 6 months after PTCA, patients underwent a control angiography. All angiographic lesions were measured by quantitative computer analysis. Four criteria were used to define restenosis. Restenosis occurred less often in the fish oil group (22.0-35.6% depending on the definition) than in the control group (40.0-53.3%). After controlling for other risk factors of restenosis, the association of fish oil supplementation with a lower frequency of restenosis was statistically significant (p = 0.03) for three of four definitions. After adjustment, a dietary intake of omega-3 fatty acids of more than 0.15 g/day was also associated with a lower frequency of restenosis (p less than or equal to 0.03). CONCLUSIONS: This trial documented the protective effect of fish oil supplements on the recurrence of coronary stenosis 6 months after PTCA. The study results suggest that a dietary intervention could be useful in preventing restenosis.

Angioplasty, Balloon, Coronary↗
PubMed1992

[Effects of valerian root oil, borneol, isoborneol, bornyl acetate and isobornyl acetate on the motility of laboratory animals (mice) after inhalation].

The aromatherapeutical use of commercial valerian root oil (Chinese origin) and of pure fragrance compounds--borneol, isoborneol, bornyl acetate (main constituent of the proved valerian root oil) and isobornyl acetate--as potentially drugs with sedative effects after inhalation was investigated in an animal experiment (mice). In additional analyses the mice were treated i.p. by caffeine and distinct sedative effects were observed only by inhalation of the cited substances.

Animals↗
PubMed1992

Sweat electrolyte loss during exercise in the heat: effects of gender and maturation.

Humans may lose large amounts of water and electrolytes from sweat during prolonged exercise in a hot climate. Gender and maturational differences for the total sweat electrolyte losses have not been reported. The purpose of this study was to compare sweat electrolyte losses of prepubescent (PP), pubescent (P) and young adult (YA) males and females, under the same environmental conditions and relative exercise intensities. Twenty-five females (8 PP, 9 P, 8 YA) and 26 males (10 PP, 8 P, 8 YA) cycled for two 20-min bouts at 50% of their peak VO2 in a climatic chamber (42 degrees C, 18% relative humidity). Sweat was collected from a plastic bag attached to the lower back. Total body sweat loss was calculated from the differences in nude body weight corrected for fluid intake, urine, and respiratory water loss. Sweat [Na+] and [Cl-] tended to increase with maturation while sweat [K+] was lower in YA compared with that of PP. Children had a lower sweating rate than YA, even when corrected for body surface area. As a result, total Na+ and Cl- losses per kg body weight from sweat (mEq.kg-1.h-1) were higher in YA compared with those of PP and P; however, no maturational difference was found in K+ losses. Within the same maturational group, there were no gender differences in any of the electrolyte losses. These results may be useful in recommending "optimal" fluid-electrolyte drinks for children exercising in the heat.

Adolescent↗
PubMed1992

Certified sick leave and work load. A case referent study among nurses.

A case-referent study assessed the association of medically certified sick leave from work with some occupational characteristics: hospital, care unit, and two work-load indices (patients' average length-of-stay, and nurse-patient ratio). Study participants were nurses from seven general hospitals in Quebec City, who had been employed for at least 6 months at the time of study. Cases (n = 1165) experienced at least one episode of medically certified sick leave between January 1, 1984 and May 31, 1987. Referents (n = 1165) were chosen from subjects who had no such leave and were matched to cases on the basis of dates on which sick leave occurred. Occupational data were collected from employment records and administrative files. Analysis was conducted using multiple logistic regression. Statistically significant associations were found between sick leave and one hospital, two care units, and nurse-patient ratio among head nurses. These odds ratios were independent of length of service in the hospital or in the actual job assignment. The study supports the pertinence of using certified sick leave as a nonspecific indicator of health outcomes.

Absenteeism↗
PubMed1992

[Multivariate study of auditory perception using multi-electrode cochlear implants].

The goal of this study was to determine the influence of auditory and cognitive factors in hearing or listening mechanisms with the Nucleus multielectrode cochlear implant. Accordingly, hearing sensitivity, psycho-acoustical masking functions and measures of temporal resolution were obtained from 14 adults with acquired deafness. In addition, six measures of open-set speech discrimination were introduced to represent a possible contribution of cognitive factors. Results indicated the contribution of both auditory and cognitive factors to speech understanding. Cognitive factors were most influential. Differences were also found in the relative importance of various cognitive factors, both before and after an intensive aural rehabilitation program. Initially, subjects relied more heavily on their ability to make efficient use of the linguistic redundancy of speech. At the end of the program, they paid more attention to speech acoustics, as a result of enhanced auditory spectral analysis and temporal resolution at about 2 kHz.

Adolescent↗
PubMed1992

Simultaneous control of ticks and tsetse flies in Satiri, Burkina Faso, by the use of flumethrin pour on for cattle.

Treatments of 2000 cattle at monthly intervals with flumethrin pour on (1 mg active ingredient/kg b.w.) resulted in a rapid decrease of African Animal Trypanosomosis (AAT). After an initial curative treatment of the sentinel herd with diminazene aceturate (7 mg/kg b.w.) only positive cases were treated. Three applications of flumethrin were sufficient to reduce the prevalence of AAT to below 5%. Apart from a slight increase at the end of the first year the infection rate varied between 0 and 5%. A tsetse population disappeared from a heavily infested habitat after six treatments. The average tick infestation was 3-10 times lower than in a control site inspite of the repeated use of another acaricide. Between 3282 and 8624 animals were treated five times in the second year at intervals of about two months. 130 monoconical insecticide impregnated traps were deployed in habitats which were inaccessible for the cattle. The highest infection rate of the sentinel herd was 1.4%. Among another 150 eartagged cattle scattered over a district of about 1000 m2 the prevalence of AAT dropped to 4.8% at the end of the second year. Emphasis is put on an active and financial participation of the rural communities to ensure a viable campaign and good prospects of a taking over by local organizations once the external interventions have stopped.

Administration, Topical↗
PubMed1991

UGA is translated as cysteine in pheromone 3 of Euplotes octocarinatus.

Pheromone 3 mRNA of the ciliate Euplotes octocarinatus contains three in-frame UGA codons that are translated as cysteines. This was revealed from cDNA sequencing and from plasma desorption mass spectrometry of cleaved pheromone 3 in connection with pyridylethylation of the fragments. N-terminal sequence analysis of carboxymethylated protein confirmed this conclusion for the first of the three UGA codons. Besides UGA the common cysteine codons UGU and UGC are also used to encode cysteine. UAA functions as a termination codon. No UAG codon was found. In connection with results reported for other ciliates, this suggests that the role of the classic termination codons had not yet been established when the ciliates started to diverge from other eukaryotes.

Amino Acid Sequence↗
PubMed1991

Haemolytic disease of the newborn infant. Long term efficiency of the screening and the prevention of alloimmunization in the mother: thirty years of experience.

During the last thirty years, the diagnosis, management and prevention of haemolytic disease of the newborn infant (HDN) have improved. From 1959 to 1988, 3004 HDN (ABO excluded) have been collected. The percentage of HDN with anti-D alloimmunization decreased significantly (98.4% from 1959 to 1968, 93.5% from 1969 to 1978 and 68.1% from 1979 to 1988). The anti-D HDN with exchange transfusion (ET) fell significantly between the first and second periods (577 versus 970; chi 2 = 19.92; P less than 0.001). On the other hand, the number of HDN other than anti-D increased during these three periods, but the percentage of these HDN which needed ET decreased. Our study shows the long term efficiency of the prevention of anti-D alloimmunization (since 1970) and of the irregular antibodies screening among all pregnant women (since 1979).

Antibodies, Anti-Idiotypic↗
PubMed1991

[Special clinical and follow-up aspects of invasive lobular breast cancer].

We examined 121 invasive lobular breast carcinomas (ILCs) with regard to certain standardised prognosis parameters, such as tumour size, receptor status, histological grading, the presence of lymphangiosis carcinomatosa, and the histological nodal status of the axillae and correlated these findings with follow-up data obtained over a mean period of 65 months. The parameters, tumour size, presence of lymphangiosis carcinomatosa, and nodal status, were found to be correlated and to have a significant influence on the patients' overall survival time, but not on relapse-free survival. Receptor status appeared to have no significant influence on patient survival. However, the incidence of death, owing to tumour-related causes, was higher among patients with receptor-negative tumours than amongst those with receptor-positive carcinomas. In contrast, the histological grading of a tumour appeared to exercise no effect on tumour prognosis. At 30%, the rate of local tumour recurrence at the primary site was markedly higher than for other histological types of breast carcinoma. In nearly one-half (45%) of such relapses, however, further tumour progression did not occur. Most tumours, exhibiting only local recurrence were initially node-negative, whilst those that produced distant metastases later had usually exhibited axillary lymph node metastases at primary therapy. Bilateral carcinomas occurred more frequently (15.6%) than is the case amongst ductal carcinoma. The observed tendency amongst ILCs toward local recurrence and bilateral growth might be accounted for in terms of their high incidence of multicentral tumour growth and associated pre-invasive neoplastic alterations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Sweat lactate in exercising children and adolescents of varying physical maturity.

This study attempts to explain some of the individual variability in sweating pattern by comparing prepubescents and pubescents. Sweating rate and muscular anaerobic capacity are higher in adults than in children; thus we hypothesized that sweat gland anaerobic metabolism, as reflected by lactate excretion, might be higher with advanced physical maturity (PM). Lactate concentration in sweat ([LAC]sw) was measured at various stages of PM in boys who exercised in the heat. The subjects were divided into three groups on the basis of Tanner staging: prepubertal (PP, n = 16), midpubertal (MP, n = 15), and late pubertal (LP, n = 5). Subjects cycled at 50% of maximal O2 uptake for three 20-min bouts, with 10-min rest periods, in 42 degrees C and 18% relative humidity. Sweat samples were harvested, and population density of activated sweat glands was determined after each exercise bout. [LAC]sw during bout 1 was higher in PP than in LP [PP = 22.2 +/- 2.2, MP = 19.5 +/- 1.4, LP = 14.3 +/- 1.3 (SE) mmol/l]. In all groups, [LAC]sw decreased during subsequent bouts, and there were no intergroup differences in [LAC]sw during bout 3 (PP = 11.2 +/- 0.4, MP = 10.6 +/- 0.5, LP = 9.7 +/- 0.2 mmol/l). [LAC]sw was inversely related to sweating rate. Lactate excretion rate per gland was greater with the increase in PM (PP = 61.0 +/- 8.2, MP = 79.1 +/- 11.3, LP = 99.9 +/- 11.0 pmol/min; P = 0.08).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

A single administration of peritoneal dialysis fluid in the rat induces an acute inflammatory exudate.

Peritoneal macrophages from uninfected continuous ambulatory peritoneal dialysis (CAPD) patients in general show two different, endogenous peroxidatic activity (PA) patterns: exudate and negative. This suggests, in accordance with the animal model, that a chronic inflammatory state is present in CAPD patients, which may be caused by mechanical stimulation or the dialysis fluid. Therefore we studied in the rat model the intraperitoneal (i.p.) administration of peritoneal dialysis fluid and physiological saline. Our results on the number of neutrophilic granulocytes, the number of macrophages and the PA pattern indicate that a single i.p. administration of commercial dialysis fluid induced an acute exudate, especially when compared with the minor saline effect. These results are confirmed by the lower percentage of macrophages positive for the differentiation antigen ED2 and in addition the higher number of Fc-receptor positive peritoneal cells, when compared with the saline effect. These findings strongly suggest that the continuous administration of the dialysis fluid, as used in CAPD patients, is the inducer of the chronic inflammatory exudate in these patients.

Acute Disease↗
PubMed1991

Leisure physical activity and age at menarche.

Early menarche has been associated with higher risk of breast cancer. A prospective study of 2487 girls, has been conducted in Quebec City, Canada, to evaluate the relationship of exercise to menarche, taking personal and family characteristics into account. Weight, height, body mass index, and abdominal and supra-iliac skinfolds were inversely associated with age of menstruation. Mother's age at menarche was positively associated with age of menstruation. Age, mother's age at menarche, and weight-adjusted incidence density ratios (IDR) showed no association between energy expenditure and onset of menstruation. Girls who participated in dance, gymnastic figure skating, synchronized swimming, or diving competitions had a lower risk of reaching menarche at an early age (IDR = 0.71 (0.51-0.97)).

Adolescent↗
PubMed1991

[Unilateral paralysis of the abdominal wall musculature caused by thoracic intervertebral disk displacement].

Herniated thoracic discs are rare. Many cases present with local radicular or cord symptoms. We describe a case which became symptomatic by a unilateral paresis of the muscles of the abdominal wall. This radicular syndrome has only been described for lumbar disc herniations before. The differential diagnosis is discussed as well as the importance of myelography and the value of Myelo-CT.

Abdominal Muscles↗