Biomedical subjects
G Martin
Publications and source records attributed to G Martin.
[Evaluation of P/S ratio and surface-tension measurements in amniotic fluid for prediction of pulmonary fetal maturity (author's transl)].
For the prediction of fetal lung maturity the palmitin stearic acid quotient (P/S ratio) was obtained by amniocentesis from 83 amniotic fluid samples of normal pregnancies, between the 28th and 40th week of pregnancy. This ratio was compared with the surface characteristics of the amniotic fluid in the Wilhelmy balance. A significant correlation was established between these two methods (correlation ellipsis r = 0.82, p < 0.01). The P/S ratio curve showed a marked increase during the 32nd and 36th week of pregnancy, indicating lung maturity. The P/S > 3 value usually reached during the 35th week of pregnancy indicates lung maturity. During the same time amniotic fluid samples were also obtained by amniocentesis from 37 complicated pregnancies. The surface tension as well as the P/S ratio were compared with the already established normal curves. A deceleration was found in cases of rhesusincompatibility and diabetes mellitus. In patients with EPH-gestosis and placental insufficiency only a slight acceleration towards the end of pregnancy was observed. Statistical proof of these trends was not feasible due to the limited number of patients in each group. Comparing the two methods regarding the predictability of pulmonary function in infants, the P/S ratio showed a larger number of false positive findings than the surface tension measurement method. Both methods produced an equal number of false negatives. Optimum results can be obtained by combining P/S ratio and surface tension measurements. This procedure is prognostically accurate in more than 96% of all cases.
Recurrent disc prolapse as a cause of recurrent pain after laminectomy for lumbar disc lesions.
Recurrent disc lesions occur in about 19 percent of patients having a primary laminectomy and occurring in just under half (46 percent) of those suffering recurrent pain. The clinical features are similar to those of a primary disc lesion. The most likely site (two out of three) is the same disc level as before, with an equal probability of involving the previous or its opposite side. Re-operation appears to carry a good prognosis, with 80 percent good results, while with conservative treatment 45 percent will settle down in less than three months.
Self-monitoring, self-administration of token reinforcement, and goal-setting to improve work rates with retarded clients.
Although many studies have demonstrated the effectiveness of self-regulation strategies with non-retarded populations, relatively few studies have examined their value for retarded workers in vocational settings. A Self-Regulation Package (SRP), which incorporated self-monitoring, self-administration of reinforcement, and goal-setting procedures, was investigated as a strategy for increasing the productivity of sheltered workshop clients. A combined multiple-baseline, multi-element, reversal-to-baseline design was used to evaluate the SRP. As a function of the presence of the SRP, production of the 8 clients increased by an average of 43% (range: 19-60). Social validation procedures revealed that clients preferred to work under the SRP conditions versus baseline conditions. Since many workshops for retarded persons have client/staff ratios which do not readily permit staff to undertake additional duties, the adoption of self-regulation strategies could represent an effective and acceptable means of assessing and improving individual rates of production.
Physicochemical characteristics of Listeria specific antigen 2.
Listeria specific antigen 2 (Ag2) was purified to within 97% of homogeneity, with a high yield, using both gel filtration and polyacrylamide gel electrophoresis. Ag2 is a glycoprotein. Its isoelectric point is about 4.2. As determined by sodium dodecyl sulphate-polyacrylamid gel electrophoresis, its molecular weight in 16710 +/- 450. Ag2 may aggregate easily since it was previously found in gel filtration in a peak corresponding to a molecular weight of 160000. No enzyme activity has been found in Ag2.
Recurrent pain of a pseudotabetic variety after laminectomy for lumbar disc lesion.
A variety of pain resembling the lightning pains of tabes dorsalis is described in patients suffering from persistent sciatica, following laminectomy for lumbar disc disease. It occurs in about 13% of those complaining of post-laminectomy pain and in 5% of all those having a laminectomy for disc disease. It is associated with damage to the nerve root and may be precipitated by nerve root resection. About half the patients may get some relief from carbamazepine or clonazepam and the syndrome shows a tendency to improve gradually over three to five years.
A supervisory strategy to improve work performance for lower functioning retarded clients in a sheltered workshop.
A multiple component strategy was investigated for aiding staff responsible for supervising production of lower functioning retarded clients on contract tasks in an institution-based sheltered workshop. The strategy was assessed in a combined multi-element, multiple baseline across groups design with a reversal component. Production performance increased during the production supervisory strategy with all 16 clients, with the range of increase varying from a few percentage points to 150% of baseline production. Both the clients and staff (responsible for conducting the research) preferred working under experimental conditions rather than under baseline conditions which approximated those found in "typical" sheltered workshops.
[Oral and dental status in pregnancy].
Explore the source record for details and available documents.
[T-cell leukaemia with receptors for IgG Fc-fraction (author's transl)].
Explore the source record for details and available documents.
Effects of lactate, pyruvate, butyrate and ammonia on gluconeogenesis from propionate by isolated rabbit liver cells.
The rate of gluconeogenesis in isolated rabbit liver cells has been measured from propionate, lactate, pyruvate and from the combination of propionate at different concentrations either with lactate or pyruvate. The glucose formed from propionate according to its concentration is about 74 to 87% of the glucose formed from lactate. No lag period was observed with preincubated cells and gluconeogenesis is linear at least from 90 min when the substrates are present at a concentration of 5 micrometers or more. Combinations of lactate + propionate increase the glucose formed as compared with propionate alone by a factor 1.5 - 1.7 according to substrates concentrations. Combinations of propionate + pyruvate decrease glucose formation in comparison with propionate alone. Conversion of pyruvate into lactate is enhanced by propionate. Glucose formation from lactate is strongly decreased by 14 micrometers quinolinate but has no significant effect on glucose formation from propionate. Amino-oxyacetate (0.2 micrometers) which decreases gluconeogenesis from lactate produced a slight enhancement of gluconeogenesis from propionate. 10 micrometers n-butylmalonate decreases gluconeogenesis by about 20-30% from three substrates. These observations are consistent with a predominant conversion of propionate into phosphoenolpyruvate intramitochondrially. Butyrate is rapidly metabolized by isolated rabbit liver cells with formation of ketone bodies. It inhibits glucose formation from propionate. 10 micrometers ammonium chloride + 2 micrometers ornithine in presence of propionate give an important ureogenesis and strongly decrease gluconeogenesis from propionate. At low concentration (0.5 micrometers), butyrate partially raises the inhibiting effect of ammonia on gluconeogenesis. This effect is progressively annulled as butyrate concentration rises to 10 micrometers. These observations are consistent with the fact that butyrate modifies the intramitochondrial ratio NADH/NAD and thereby the oxidation of malate formed from propionate.
[Geographic polymorphism of the "valence" of sexual chromosomes, and the monogeny resulting from the crossing of different populations of Porcellio dilatatus Brandt (Crustacea, Isopoda, Oniscoidea)].
Explore the source record for details and available documents.
Comparison of two reinforcement strategies in vocational-skill training of mentally retarded persons.
While recommendations concerning reinforcement strategies in vocational training of retarded persons range from the use of minimal social reinforcement to the use of extra social and edible reinforcement, empirical comparisons of such strategies could not be found in the literature. Four experiments were conducted to compare minimal social reinforcement to social plus edible reinforcement while lower functioning retarded clients were taught assembly tasks of varying complexities. In all experiments, the extra reinforcement generally facilitated the learning of a task to criterion in terms of training time, number of trials, total number of errors, and the proportion of errors on learned steps. Moreover, a preference test showed that the majority of clients preferred the extra reinforcement condition.
[Idiopathic mitral valve prolapse syndrome (MPS). Apropos of a series of 80 cases].
Explore the source record for details and available documents.
Polyarthralgia associated with disc lesions.
Explore the source record for details and available documents.
[Industrial physiological studies on trashmen during domestic refuse removal using 110-liter trash barrels and large trash receptacles].
Explore the source record for details and available documents.
[Surface properties of serum in case of premature onset of labour (author's transl)].
Fifty-eight pregnant women with premature onset of labour were compared to 149 women with normal course of pregnancy. Surface activity of the serum in the former group was found to be higher than that in the latter. The information obtained from determining the hysteresis curve of the serum by means of Wilhelmy's balance was much more complete than that recordable from surface tension with 20 per cent surface expansion (gamma minimum). An analysis was made, at the same time, of those serum parameters with highest surface activity, such as free fatty acids and lecithin. Their growth in concentration was found to coincide with onset of labour proper rather than with a condition in which the organism simply exhibited a trend towards premature labour. Hence, measurement of serum surface tension proved to be the more sensitive parameter by which to predict forthcoming premature labour. The actual cause underlying such behaviour so far has remained unelucidated, since an extremely sophisticated process has to be assumed to take place on the serum surface. These studies, consequently, have not been completed. They are likely, however, to provide some preliminary hints on quite peculiar serum changes in concomitance with premature labour or with the trend to it.
[Dynamic surface tension measurements and L/S-ratio in amniotic fluid before birth in comparison with the respiratory compliance of the newborns immediately after parturition (author's transl)].
In 65 pregnant women between 27th and 42nd gestational week amniotic fluid was collected on average of 4,2 hours before birth and its amount of surfactant determined by means of the dynamic surface tension measurement in the Wilhelmy-balance and the L/S-ratio. These values were compared to the respiratory compliance of the newborns after birth. The respiratory compliance was measured by means of the airway occlusion technique. So far the measurement of dynamic surface tension has made it possible to predict the lungmaturity and the incidence of RDS. Our study for the first time describes a quantitative relationship between the surface tension of the amniotic fluid and the surface tension of the lungs in form of the respiratory compliance. The surface tension, measured by the Wilhelmy-balance, was better correlated (r = -0.85) than the L/S-ration (r = 0,58) with the respiratory compliance of the newborns. The surface tension measurement allows therefore a better prediction of the severity of the RDS than the determination of the L/S-ratio. This can be explained by the fact that the surface tension measurement in the amniotic fluid represents the total effect of SAM (Surface active material) while the L/S-ratio represents only about 60% of SAM. On the other hand the L/S-ratio gave a better correlation to the general maturity of the fetus than the surface tension; therefore we consider that the L/S-ratio is partially influenced by the lungmaturity and partially by gestational age of the fetus.
[Preprosthetic periodontal surgery with respect to the palatal loss of dental tissues].
Explore the source record for details and available documents.