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Biomedical subjects

J Herrmann

Publications and source records attributed to J Herrmann.

At least 19 recordsLinked to original sources
PubMed1992

Trisomy 15 with loss of the paternal 15 as a cause of Prader-Willi syndrome due to maternal disomy.

Uniparental disomy has recently been recognized to cause human disorders, including Prader-Willi syndrome (PWS). We describe a particularly instructive case which raises important issues concerning the mechanisms producing uniparental disomy and whose evaluation provides evidence that trisomy may precede uniparental disomy in a fetus. Chorionic villus sampling performed for advanced maternal age revealed trisomy 15 in all direct and cultured cells, though the fetus appeared normal. Chromosome analysis of amniocytes obtained at 15 wk was normal in over 100 cells studied. The child was hypotonic at birth, and high-resolution banding failed to reveal the deletion of 15q11-13, a deletion which is found in 50%-70% of patients with PWS. Over time, typical features of PWS developed. Molecular genetic analysis using probes for chromosome 15 revealed maternal disomy. Maternal nondisjunction with fertilization of a disomic egg by a normal sperm, followed by loss of the paternal 15, is a likely cause of confined placental mosaicism and uniparental disomy in this case of PWS, and advanced maternal age may be a predisposing factor.

Adult↗
PubMed1979

Parachute mitral valve, coarctation of aorta, radius aplasia, and omphalocele in an infant with the trisomy 18 syndrome.

A premature infant with trisomy 18 had cardiac defects including parachute mitral valve, coarctation of the aorta, and a subcristal ventricular septal defect. The parachute mitral valve was funnel-shaped with a moderately-thick cone of fibrous tissue around the annulus and an eccentric orifice. Many forms of congenital cardiac defects have been described in the 18 trisomy syndrome. However, parachute mitral valve has not, to our knowledge, been part of the spectrum of cardiac defects in trisomy 18. Other anomalies were absent radii, omphalocele, and cleft palate and cleft lip; these have been observed previously in the 18 trisomy syndrome.

Abnormalities, Multiple↗
PubMed1979

[Kinetics of furfural formation as related to heating, concentration and storage of orange juices and concentrates].

According to studies on an orange concentrate diluted back with distilled water to the desired extract content, the formation of furfural follows the pattern of a consequent reaction. After the induction period, the reaction curve takes a linear course cooresponding to a reaction of a zero order. The temperature dependence of the resultant reaction constant k obeys the ARRHENIUS equation and yields the same energy of activation for all the extract contents under investigation. This is a case of specific acid catalysis, because the reaction velocity is directly proportional to the hydronium ion activity. On a semilogarithmic scale, the dependence of the k values of the extract contents of the concentrates and of the re-constituted juice can be presented for various temperatures in the form of parallels. According to the literature, the amount of the furfural produced correlates with the quality of the orange juices and concentrates. Consequently, this amount might be used as an indicator in evaluating quality deteriorations due to unsuitable manufacturing and storage on the one hand, and for the computation and optimization of the manufacturing processes and parameters on the other hand.

Food Handling↗
PubMed1979

Syndrome delineation. 1. Malformations and dysplasias.

A practical classification of genetic disorders and birth defects divides them into five categories: malformations, dysplasias, inborn errors of metabolism, deformities, and variant familial developmental patterns. The first two categories are discussed here. The last three will be discussed next month in part 2.

Abnormalities, Drug-Induced↗
PubMed1979

Syndrome delineation. 2. Inborn errors of metabolism, deformities, and variant familial developmental patterns.

Classification of genetic disorders and birth defects into the following five categories aids in efficient patient evaluation, prognostic counseling, and therapy: malformations, dysplasias, inborn errors of metabolism, deformities, and variant familial developmental patterns. These categories highlight different pathogenetic aspects of disease processes. Mixed disorders with manifestations from the different categories may be of special significance.

Abnormalities, Multiple↗
PubMed1979

Clinical genetics and pediatric neoplasms: pathogenetic and etiologic perspectives.

Clinical and genetic aspects of pediatric neoplasms were reviewed from pathogenetic and etiologic perspectives. Developmental principles and phenomena common to several tumors and tumor syndromes were identified, summarized, and critically evaluated. Their enumeration may be useful in future cancer research. No single hypothesis on the cause and pathogenesis of cancer appears to apply to all disorders. We believe that multiple causes and pathways lead to the phenotype "cancer" and that in particular the pathogenetic relationship between tissue dysplasias and cancers deserves increased attention.

Child↗
PubMed1978

[Risk to patients with latent or manifest hyperthyroidism through iodine-containing contrast media and drugs (author's transl)].

Severe iodine-induced hyperthyroidism occurred in 25 patients with, at the time not yet fully diagnosed thyroid function after administration of iodine-containing contrast media, disinfectants or drugs, in four of them precipitating a thyrotoxic crisis. As iodine-induced hyperthyroidism is often resistant to the usual antithyroid treatment, thyroid function should be checked whenever the use of iodine-containing contrast media is indicated.

Adult↗
PubMed1978

[Thyrostatics].

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Adult↗
PubMed1978

[Effect of estrogen upon thyroid metabolism (author's transl)].

During enhanced endogen estrogen production (pregnancy) as well as during exogen estrogen application a rise occurs in TBG concentration in serum, which seems to be dose related. Simultaneously with the TBG there is an increase in total T4 and T3; the concentrations of the free T4 and T3 however decrease. Towards the end of pregnancy AFT4 is significantly decreased, compared to the controls, AFT3 being in the lower normal range. The lower concentrations of the free hormones are also documented by a decline in the T4/TBG and T3/TBG ratios. Normal basal TSH concentration in serum suggest a metabolic state which is still compensated. Oral contraceptives with low estrogen content have no influence on TBG, T4 and T3 concentrations.

Contraceptives, Oral, Hormonal↗
PubMed1978

[Thyroid hormones].

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Biological Transport↗
PubMed1978

Non-glucoregulatory hormones (T4, T3, rT3, TSH, testosterone) during physical exercise in juvenile type diabetics.

Non-glucoregulatory hormones (T4, T3, rT3, TSH and testosterone) were studied by radioimmunoassay in juvenile-type diabetics in moderate control and in ketosis due to insulin withdrawal and in age matched "normals" during a mild prolonged exercise test. The basal serum hormone levels revealed the following findings: Serum testosterone was markedly lower in diabetics than in normals ( 177 +/- 24 resp. 618 +/- 52 ng/dl). This is in contrast to other studies, but it may reflect decreased testicular function due to an early, clinically not apparent atherosclerotic disease. Serum T3 was significantly lower in diabetics than in normals (110 +/- 16 resp. 145 +/- 19), suggesting an early "low T3-syndrome" in juvenile-type diabetics. However, increased serum rT3 levels were not observed, and serum T4 and TSH were normal. Mild prolonged exercise had no major effects on these nonglucoregulatory hormones. In juvenile-type diabetics the degree of metabolic control had no influence on the response of the mentioned hormones. However, an increased cortisol/testosterone ratio in ketotic diabetics in the basal state with a further increase during exercise was demonstrated, indicating an aggravation of the catabolic state in these patients during exercise.

Adult↗
PubMed1978

[Kinetics of the temperature dependence of thermal activation and inactivation of bacterial endospores as a consequential reaction].

Reaction kinetics explains the thermal activation and destruction of bacterial endospores as a consequent reaction with the activation rate constant k 1 of the resting spores N 0 and the destruction rate constant k 2 of the heat-activated spores N ++: (formula see text). If one takes also into account the activated spores already present in a suspension, one obtains, at constant temperature, destruction curves that become straight lines when plotted semi-logarithmically or correspond to the convex and concave curves often described in the literature. The D value of destruction must be calculated from the k value of the slowest reaction. Experiments with endospores of Bac. subtilis showed that k 1 greater than k 2 at temperatures less than 100 degrees C, and k 2 greater than k 1 at temperatures greater than 135 degrees C. In case of further confirmation of this theory, far-reaching conclusions might be drawn as to the calculation of the sterilization of F value.

Bacillus subtilis↗