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Biomedical subjects

D Stern

Publications and source records attributed to D Stern.

179 records · Page 10Linked to original sources
PubMed1980

A study of lower-limb mechanics during stair-climbing.

The motions, forces, and moments at the major joints of the lower limbs of ten men ascending and descending stairs were analyzed using an optoelectronic system, a force-plate, and electromyography. The mean values for the maximum sagittalplane motions of the hip, knee, and ankle were 42, 88, and 27 degrees, respectively. The mean maximum net flexion-extension moments were: at the hip, 123.9 newton-meters going up and 112.5 newton-meters going down stairs; at the knee, 57.1 newton-meters going up and 146.6 newton-meters going down stairs; and at the ankle, 137.2 newton-meters going up and 107.5 newton-meters going down stairs. When going up and down stairs large moments are present about weight-bearing joints, but descending movements produce the largest moments. The magnitudes of these moments are considerably higher than those produced during level walking.

Adult↗
PubMed1977

Accuracy of physicans' predictions of cholecystography results.

In the decision theory model of medical diagnosis and treatment, optimal choice of diagnostic tests requires accurate estimation of the probability that a given test will be positive. We assessed the ability of physicians to estimate the probability that a specific test (cholecystography) would be positive. For 102 patients, the predicted number of gallstone cases, 35.8, was significantly greater than the observed number, 15 (p less than 0.001), even though 13 of the 15 observed cases were patients with previous radiographic evidence of gallstones. The overestimation of probability of positive tests casts doubt on the correctness of decisions regarding selection of diagnostic tests when these decisions are derived from probability estimates based on intuition or expert opinion.

Adult↗
PubMed1976

Oral lesions in fucosidosis.

The oral lesions in two previously reported cases of fucosidosis are discussed. The patients have coarse facies, severe mental retardation, spondyloepiphyseal dysplasia, deficiency of a-L-fucosidase, and red punctate lesions of the skin and oral mucosa. Gingival biopsy specimens showed that these lesions were identical to the angiokeratoma corporis diffusum reported in Fabry's disease, but had different locations. Because of the slowly progressing psychomotor retardation and recurrent upper respiratory tract infections that the prognosis for patients with this disease is poor. Treatment appears to be aimed at early diagnosis through amniocentesis.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1975

An outbreak of hepatitis associated with intravenous injection of factor-VIII concentrate.

An outbreak of jaundice associated with three out of four batches of a commercial brand of freeze-dried factor-VIII concentrate occurred at the Bournemouth haemophilia centre between April and June, 1974. Seven cases of non-B hepatitis and four of hepatitis B occurred within 6 months of the first use of this product. Two patients contracted both types of hepatitis; thus nine patients became ill out of a total of twenty regularly seen at the centre, eighteen of whom received commercial factor-VIII concentrate.

Antibodies, Viral↗
PubMedDate not supplied

Alzheimer neurofibrillary lesions: molecular nature and potential roles of different components.

Neurofibrillary lesions found in Alzheimer disease (AD) are known to react with antibodies raised against different molecules. At least 20 components have been detected in neurofibrillary tangles. These components can be roughly categorized into five groups, which include structural proteins, kinases and other cytosolic enzymes, stress-related molecules, amyloid and amyloid binding proteins, and others. Among them, an abnormal form of microtubule associated protein tau, PHF-tau, is a major component of Alzheimer NFT. Kinases associated with NFT, especially those belonging to the family of proline-directed Ser/Thr kinases, are considered to be important for PHF-tau hyperphosphorylation. A potentially significant kinase is a Cdc2-related kinase, which is associated tightly with paired helical filaments, has a molecular weight of 33kDa and is different from other known Cdc2-related kinases. The possibility that some of the NFT-associated elements may play an active role in the pathogenesis of Alzheimer's disease was supported by recent studies, in which advanced glycated products and markers of oxidant stress were located in NFT. In addition, PHF-tau was found to be glycated, and in vitro glycated tau was capable of inducing oxidant stress. Further characterization of different components of NFT by biochemical and other approaches will be important for understanding the mechanisms involved in the supramolecular aggregation of PHF within NFT.

Alzheimer Disease↗
PubMedDate not supplied

On some of the in organello processes involved in the biogenesis of chlorophyll-protein complexes.

The biogenesis and assembly of chlorophyll-protein complexes consist of many steps. These are initiated with the transcription and translation of the different polypeptide components constituting the complexes. For the nuclear-encoded subunits the synthesis takes place in the cytoplasm, and they are synthesized as precursors, which are later imported into the chloroplast. Within the organelle, the precursors are inserted into the thylakoid membranes, as well as being processed to their mature forms. The different nuclear- and chloroplast-encoded subunits assemble together, and bind the pigments and other cofactors to form the active pigmented-complex. In the present article, we discuss only the in organello processes of the biogenesis. We describe the pathways taken by two nuclear-encoded thylakoid proteins, the precursor of the main light-harvesting chlorophyll-protein of photosystem II (pLHCP) and the precursor of photosystem I subunit II (pre subunit II). These polypeptide subunits, that are located in two different photosynthetic complexes, differ from each other. While pLHCP is an integral membrane protein, which binds pigments, photosystem I-subunit II is a peripheral membrane protein, located on the stromal side of the thylakoids, and is not predicted to span it. The differences and the common features of the in organello biogenesis pathways of these two proteins are discussed.

Apoproteins↗