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Biomedical subjects

S Meyer

Publications and source records attributed to S Meyer.

At least 271 records · Page 15Linked to original sources
PubMed1984

A method for assaying aryl hydrocarbon hydroxylase in man using fibroblasts cultured in vitro from oral mucosa.

Animal studies have linked aryl hydrocarbon hydroxylase (AHH) with cancer induction by polycyclic aromatic hydrocarbons (PAH), but the relationship between the activation of PAH by AHH and cancer induction in man is unclear. Studies using human lymphocytes to investigate this relationship have produced conflicting results. This report describes a technique for assaying AHH in fibroblasts isolated and cultured from normal human oral mucosa. Fibroblasts were cultured from normal portions of routine oral mucosal biopsy specimens obtained from 6 patients, and AHH activity was found in fibroblasts cultured from all the specimens. AHH activity was induced by 1,2-benzanthracene and reached a peak after 48 h. The assay had a pH optimum of 8.6 and an absolute requirement for reduced nicotinamide-adenine dinucleotide phosphate. The fibroblasts maintained their inducibility of AHH through 11 cell passages. Fibroblasts cultured from oral mucosal biopsy specimens offer several advantages over other systems for comparison of individual differences in AHH activity in man, including the consistent presence of inducible AHH activity, stability of enzyme activity in culture, provision of ample number of cells for study, and availability of oral mucosal specimens from patients having routine diagnostic biopsies.

Aryl Hydrocarbon Hydroxylases↗
PubMed1984

Precocious puberty in myelomeningocele patients.

Of a group of 79 patients (45 males, 34 females) with myelomeningocele (MMC), 52 had associated hydrocephalus. Three of the hydrocephalic patients (two arrested and one shunted) were found to have precocious sexual development. Endocrine investigations confirmed true isosexual precocity. Hydrocephalus is known to be associated with precocious puberty, but the occurrence of sexual precocity in patients with hydrocephalus in conjunction with MMC has not been described to date. As the clinical diagnosis of hydrocephalus in a young child is often unreliable, routine computerized tomographic scans of all MMC patients is advised, and even patients with arrested hydrocephalus should be followed carefully for signs of precocious puberty. In addition, a high incidence (15%) of cryptorchidism was found in the group of MMC patients reviewed.

Child↗
PubMed1984

Low serum 24,25 dihydroxyvitamin D in Duchenne muscular dystrophy.

Levels of serum 24,25(OH)2D3 (0.69 +/- 0.17 ng/ml) were lower in DMD patients than in age-matched controls (2.13 +/- 0.15 ng/ml). Circulating levels of 1,25(OH)2D3 and 25(OH)D3 were within the accepted normal range. Bearing in mind the proposed pathophysiologic role of calcium in DMD and the influence of vitamin D metabolites on muscle ATP and protein synthesis, as well as on sarcoplasmic reticulum calcium transport and muscle mitochondrial calcium content, the above findings of low or deficient 24,25(OH)2D3 levels in DMD could be meaningful from the etiologic and therapeutic points of view.

24,25-Dihydroxyvitamin D 3↗
PubMed1984

[Experiences with transparenchymal coral calculi removal under local hypothermia].

Under certain conditions genuine coral calculi are an absolute offication for nephrotomy. In order to achieve complete hygienization of the cavity ischaemia times of more than 25-30 min are often necessary. Controlled surface cooling proved to be very good for improving ischaemia tolerance and reducing post-ischaemic loss of function in 21 necessary nephrotomies out of a total of 651 operations for concrements in the calyx system of the renal pelvis (= 3.2%; = 32.8% of all nephrotomies). A kidney thermometer with a temperature feeler developed by us allows fine control of the hypothermia induced by means of plastic bags filled with ice crystals. The technique of operation together with its advantages and disadvantages are described.

Humans↗
PubMed1984

Rehabilitation aspects of Apert's syndrome.

Two children with the unusual condition known as Apert's syndrome are presented. Both have the typical manifestations of the syndrome: craniosynostosis, exorbitism, hypertelorism, maxillary hypoplasia, dental malocclusion, cleft palate, compound syndactyly of the hands and simple syndactyly of the feet. A review of the latest surgical procedures for correction of these defects is presented and the importance of early physical and social rehabilitation is stressed.

Acrocephalosyndactylia↗
PubMed1983

Platelet abnormalities in muscular dystrophy.

Platelets which have complex membranes and calcium shifts similar to those in muscles were investigated in 14 patients with muscular dystrophy and 20 suitable controls. In 4 Duchenne and one limb-girdle dystrophy aggregations were done and found to be depressed with adrenaline and ADP. Electron microscopic and chemical examinations revealed an increased number of dense bodies, changed permeability and/or binding of cations and elevated intracellular calcium in all the 9 cases of Duchenne dystrophy while the 2 limb-girdle and 3 myotonic dystrophies varied. A two phase polymer separation system applied to fixed platelets of all patients and controls showed no abnormality of surface negative charge.

Adolescent↗
PubMed1983

Inferior vena cava anomalies associated with giant omphalocele--a proposed classification.

Thirteen patients with hepatomphaloceles were investigated pre-operatively by an inferior venocavogram as to the shape of the eviscerated liver and the course of the inferior vena cava. Roentgenographic findings correlated with operative findings and three distinct patterns of anomaly were seen. Type 2 and particularly Type 3 are likely to be associated with severe post-operative complications if the peculiar anatomy is not recognized beforehand. We feel that a pre-operative inferior venocavogram and determination of type of anomaly is mandatory in planning the treatment of these patients.

Angiography↗
PubMed1983

Muscle regeneration and transplantation enhanced by bone marrow cells.

This work was undertaken in an attempt to improve the usually poor results of muscle regeneration and grafting in cases of muscle injury. Since bone marrow cells markedly increase myogenic growth in vitro (in Millipore diffusion chambers), we added autogenous and isologous bone marrow cells to minced muscle grafts or to sites of excised muscle in rats. In each case the opposite side was left without added marrow cells, to serve as a control. The results showed that addition of bone marrow produces more extensive muscle regeneration with little fibrosis. The myogenesis-stimulating and antibacterial properties of bone marrow cells warrant further study, aiming towards clinical application of the method.

Animals↗
PubMed1982

Studies of platelets with heavy metal impregnation techniques.

Various methods of heavy metal impregnations were performed on human platelets. The optimal technique consisted of glutaraldehyde fixation, incubation in warm uranyl acetate at a pH of 3.5, followed by a double solution of lead and copper, and finally overnight immersion in cold osmium tetroxide. Semi-thin sections, viewed at 90 kV, revealed three types of platelets: (1) 'reticular' cells, with a prominent tubular network and very dark granules in a pale cytoplasm; (2) 'dark' cells, with an electron-dense cytoplasm; and (3) 'pale' cells, with microvesicles and non-staining granules. Pre-treatments with EGTA, aspirin and various platelet activators altered the appearances and proportions of the three cell types. A cell-partitioning two-phase polymer system showed that the sub-grouping is related to surface membrane properties, the cells retained in the top phase being exclusively type 2 'dark' cells. The changes in cell type distribution produced by activation show that metal impregnation may be a useful method for studying structure-function correlations in platelets.

Aspirin↗
PubMed1982

Enhancement of human muscle growth in diffusion chambers by bone marrow cells.

Samples of minced human muscle were cultured in millipore diffusion chambers incubated in the peritoneal cavities of mice. In about half the chambers the minced muscle samples were mixed with autogenous bone marrow cells which lead to improved myogenic growth. A similar but less marked effect was produced by mononuclear cells from the patients' blood. No growth enhancement occurred when the muscle and marrow cells were separated by a filter in double chambers. In addition to accelerated myogenesis, the chambers with added bone marrow cells had a much lower incidence of infection. This work may have practical clinical implications for the treatment of muscle injuries. Local implantation of autogenous marrow cells (+/- minced muscle) may prove useful in improving myogenic regeneration.

Adolescent↗