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Biomedical subjects

S Beer

Publications and source records attributed to S Beer.

At least 73 records · Page 4Linked to original sources
PubMed1982

Measuring chlorophyll a and C-labeled photosynthate in aquatic angiosperms by the use of a tissue solubilizer.

A compound that quantitatively correlated with chlorophyll a could be measured fluorometrically in the extracts of leaves of three aquatic angiosperms (Myriophyllum heterophyllum Michx., Potamogeton crispus L., Elodea canadensis Michx.) treated with the tissue solubilizer BTS-450. Fluorescent characteristics of the solubilized plant tissues were stable for several weeks in the dark at temperatures up to 60 degrees C but rapidly degraded in sunlight or when acidified. (14)C-Labeled photosynthate, which had been fixed by leaf discs during 1- to 10-hour exposure to H(14)CO(3), was also readily extracted by the tissue solubilizer. Solubilizer extraction can, therefore, be used to determine both chlorophyll a content and (14)C incorporation rates in the same leaf sample. The method is practical, because no grinding is required, the fluorescent characteristics of the extracts are stable, and analyses can be performed with very little plant material (about 3 milligrams).

Journal Article↗
PubMed1982

Photosynthesis in submersed macrophytes of a temperate lake.

The photosynthetic carbon fixation pathways and levels of carbon-fixing enzymes of four dominant submersed macrophytes of Lawrence Lake, southern Michigan, were investigated during the main growth season (May to November). All four species (Scirpus subterminalis Torr., Najas flexilis (Willd.) Rostk. and Schmidt, Potamogeton praelongus Wulf., and Myriophyllum heterophyllum Michx.) were C(3) plants based on their patterns of (14)C pulse-chase incorporation. High levels of phosphoenolpyruvate carboxylase were also found in these species. These levels, as well as the ribulose 1,5-biphosphate carboxylase/phosphoenolpyruvate carboxylase ratio of the leaves, varied throughout the growing season and exhibited highest values in July. No shift in carbon fixation pathways, however, could be detected from July to October. The possible functions of phosphoenolypyruvate carboxylase in these plants, as well as the significance of C(3) metabolism in submersed plants of temperate lakes, are delineated.

Journal Article↗
PubMed1982

Comparison of serum theophylline levels in asthmatic children receiving sustained-release and rapid-release theophylline tablets.

Serum theophylline levels were compared after the administration of a sustained-release (Theo-Dur, Key Pharmaceuticals, USA) vs. a rapid-release (Glyphyllin, Ikapharm, Israel) theophylline preparation to 24 children suffering from chronic bronchial asthma. They received each of the two drugs for a 5-d period, and serum theophylline levels were determined on the 6th d. Therapeutic serum levels were achieved in 66.6 and 75% of the patients receiving sustained-release and rapid-release theophylline preparations, respectively. The peak-trough difference for the rapid-release drug was higher than that of the sustained-release preparations (5.5 +/- 2.6 micrograms/ml vs. 2.6 +/- 2.3 micrograms/ml). Both drugs caused nearly the same low percentage of side effects (15 and 16.6%). A noncompliance rate of 16.6% was found with the rapid-release drug, and all the parents preferred the sustained-release drug is preferable for chronic treatment of children with bronchial asthma, as it maintains more stable serum theophylline levels and has a higher compliance rate.

Adolescent↗
PubMed1981

Vitamin D resistant rickets with alopecia: a form of end organ resistance to 1,25 dihydroxy vitamin D.

A 4-year-old girl presented with severe clinical and radiological rickets, and alopecia since the age of 1 year. Laboratory studies revealed: hypocalcaemia, hypophosphataemia, secondary hyperparathyroidism, abnormally low intestinal calcium absorption, and markedly elevated circulating 1,25(OH)2D3 levels. A normal calcaemic response to parathyroid extract was obtained. Treatment attempts with vitamin D2, 1 alpha (OH)D3 and 1,25(OH)2D3 were totally ineffective. Intestinal resistance to the action of 1,25(OH)2D3 appeared well established in this case. Refractoriness of bone to this hormone seems less certain. From this new entity of 'Vitamin D resistant rickets due to end organ unresponsiveness', six cases have been hitherto reported in the literature. However, only two have enough resemblance to our case, to constitute a distinct and well defined nosologic subunit. The molecular basis of this disorder(s) remains to be elucidated.

Alopecia↗
PubMed1981

Factor XIII deficiency.

A girl and her newborn brother with factor XIII deficiency from a family, which has not previously been reported, as described; two other Israeli families are reviewed. The sexes are equally affected. In two of the three families there was consanguinity among the parents. The families fit autosomal recessive inheritance and rule out X-linked recessive mode of transmission. The proposita was born to unrelated healthy parents from the Bnei Israel Jewish community of Bombay. She was re-admitted to hospital at the age of 15 days after umbilical bleeding. Later in infancy there were repeated haematomata and the diagnosis of factor XIII deficiency was established at the age of 1 1/2 years.

Child↗
PubMed1981

[Postoperative respiratory therapy: bronchospasmolytic activity and side-effects of some recently introduced beta-sympatheticomimetic agents (author's transl)].

Intensive respiratory therapy is essential for reducing postoperative morbidity and mortality in older persons with pre-existing chronic obstructive pulmonary diseases. A new series of beta-adrenergic agents is being frequently used to effect bronchodilatation. Three substances from this group, viz.: reproterol (Bronchospasmin), terbutalin (Bricanyl) and fenoterol (Berotec) were examined in a randomized study in 90 patients. All three substances produced a significant increase in FEV1 and PEFR of up to 10.6 and 15.7 per cent respectively above the initial values. There were no significant differences between the three groups. Contrary to the results obtained by other investigators PaO2 fell in all groups. In the case of fenoterol this decrease was statistically significant with a mean value of 0.36 kPa. The causes for this fall in arterial oxygen pressure are still unknown. It may possible be due to an increased intrapulmonary right-left shunt as a result of increased cardiac output together with a ventilation-perfusion mismatch despite improved airways resistance. Since drastic falls by as much as 2.53 kPa have been observed during treatment with these agents they constitute a potential risk.

Adult↗
PubMed1979

Autosomal recessive sudden unexpected death in children probably caused by a cardiomyopathy associated with myopathy.

The propositus, who died suddenly at the age of 22 months, was investigated because of an unusual myopathy. Family history revealed two sisters and four cousins who had also died suddenly and unexpectedly. The finding of asymmetric septal hypertrophy by echocardiography in the propositus suggested that the cause of the sudden death in the relatives was an undetected cardiomyopathy accompanying a mild and often subclinical myopathy. The affected children were in two sibships and both sets of parents were first cousins. The mother of one sibship was the sister of the father of the other. It is suggested that a gene causes a mild autosomal recessive myopathy with cardiomyopathy that is often undiagnosed and usually ends in sudden unexpected death in the second year of life. The same gene may manifest on echocardiogram in some heterozygotes as asymmetric septal hypertrophy.

Cardiomyopathies↗
PubMed1979

[Larsen's syndrome].

Explore the source record for details and available documents.

Abnormalities, Multiple↗
PubMed1978

Biochemical, genetic and ultrastructural study of a family with the sea-blue histiocyte syndrome/chronic non-neuronopathic Niemann-Pick disease.

Deficient leucocyte sphingomyelinase activity has been demonstrated in a patient with the sea-blue histiocyte syndrome. Family studies revealed that two other cases previously diagnosed on clinical and histochemical criteria also had a pronounced diminution of sphingomyelinase activity. Both parents of the affected individuals were carriers of the disease as indicated by sphingomyelinase activity intermediate between normal and diseased subjects. Additional heteroxygous carriers were found among the siblings and other relatives of the patients. This family study supports further the hypothesis that the sea-blue histiocyte syndrome and chronic Niemann-Pick (Type B) disease are the same.

Adolescent↗
PubMed1977

Mental retardation with 45 chromosomes 45,XX,--5,--14,+der(5) t(5,14)(p15;q13) mat due to familial balanced reciprocal translocation.

A girl with severe mental retardation and odd facies and some features of the cri-duchat syndrome was found to have only 45 chromosomes. Her karyotype was 45,XX, -5, -14,+der(5) t(5,14)(p15;q13) mat. Her mother and her two sisters were found to be balanced reciprocal translocation carriers having 46 chromosomes, one of which was a very small (14pter leads to 14q13::5p15leads to 5pter) that was missing in the proposita.

Child↗