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Biomedical subjects

R Steinherz

Publications and source records attributed to R Steinherz.

At least 37 records · Page 2Linked to original sources
PubMed1987

Cystinosis phenotypes have identical defective cystine clearance pattern.

Exposure of cultured skin fibroblast of normal, infantile nephropathic, juvenile-late-onset and adult type cystinotic patients and their corresponding obligate heterozygotes to 0.5 mmol/l of 35S cystine dimethyl ester for 30 minutes, resulted in an accumulation of cystine within the cells, and was used to look for differences in cystine clearance between the different cell types. The results suggested that all cystinotic variants are defective in their capacity to eliminate cystine to the same extent. The presented data imply that, separate clinical phenotypic variants of cystinosis, cannot be differentiated biochemically by the assay of cystine egress.

Adult↗
PubMed1986

Interstitial 7q deletion [46,XY,del (7) (pter----cen::q112----qter)] in a retarded quadriplegic boy with normal beta glucuronidase.

A 14-year-old severely retarded male with deletion of chromosomal band 7 cen----q112 is described. Clinical features include short stature, microcephaly, unusual facies with narrow forehead, short nose, malar hypoplasia, protruding alveolar ridges and incisors, receding chin, relatively long philtrum, and large ears. In addition, he had bilateral inguinal herniae cryptorchidism with hypogonadism, pulmonic stenosis, and spastic quadriplegia. Normal activity of beta-glucuronidase was found in the patient's leukocytes. This finding suggests that the gene is not in the deleted region, narrowing the smallest region of overlap to 7q112----q22.

Abnormalities, Multiple↗
PubMed1986

Acute dystonic reaction to bethanechol--a direct acetylcholine receptor agonist.

Bethanechol is a direct agonist of the acetylcholine receptor that was recently introduced in the therapy of gastro-oesophageal reflux. Acute dystonic reactions to bethanechol were observed in a 10-month-old infant who also demonstrated similar dystonic reactions to dopamine receptor blocking agents of two different classes. This first report of acute dystonic reaction to cholinergic agonists in human is in accord with the current theories of the rôle of acetylcholine and dopamine in the pathogenesis of acute dystonic reactions.

Acute Disease↗
PubMed1986

Possible Waardenburg syndrome with gastrointestinal anomalies.

We describe a patient with possible Waardenburg syndrome associated with anal atresia and oesophageal atresia with tracheooesophageal fistula. Three other published cases with atretic gastrointestinal anomalies associated with the Waardenburg syndrome are reviewed. We conclude that the association between atretic lesions of the gastrointestinal tract and the Waardenburg syndrome may be a significant one.

Abnormalities, Multiple↗
PubMed1986

Adenovirus type 3 infection with systemic manifestation in apparently normal children.

Between July 1983 and February 1984, eight children with adenovirus Type 3 infection, proven by virus isolation from sputum, stool or nasopharyngeal swabs and a fourfold increase in complement fixation antibody titers against the virus, were treated in our department. All eight patients had fever lasting at least 7 days, hepatomegaly, diffuse pulmonary infiltrates and abnormal liver function tests. Seven of the patients exhibited dyspnea and pulmonary wheezing. Six of the patients developed changes in state of consciousness, and three had repeated convulsions. EEG patterns in three of the patients were compatible with encephalopathy. Other clinical manifestations included: follicular tonsillitis in two patients, diarrhea in two, pneumothorax in one, and shock with disseminated intravascular coagulation in one. The spectrum of adenovirus Type 3 infection reported here has been described previously only in the viral hemorrhagic fevers. This adenovirus Type 3 infection shares the potential for disseminated disease that has been described previously for Type 7, simulating Reye's syndrome.

Adenoviridae Infections↗
PubMed1986

Unusual ophthalmological findings in a case of partial trisomy 15.

The clinical and pathological findings in a two-month old girl having partial trisomy 15, are presented. The patient showed bilateral microphthalmia accompanied by a retrolental mass in her left eye. She underwent vitrectomy, lensectomy and accidental retinectomy. During the course of the operation, persistent hyperplastic primary vitreous (PHPV) was found with findings of retinal dysplasia on the pathologic examination.

Chromosomes, Human, Pair 15↗
PubMed1985

X-linked lymphoproliferative syndrome. A new kindred with variable phenotypic expression.

A kindred with five affected maternally related male members showed variable phenotypic expression of the X-linked lymphoproliferative syndrome. In one of the children, agammaglobulinemia developed following infectious mononucleosis. His brother had aplastic anemia in infancy and 21/2 years later died of overwhelming pneumonia resulting from ornithosis. A third brother died of reticulum cell sarcoma. Two maternally related male cousins died of reticulum cell sarcoma of the neck.

Adolescent↗
PubMed1985

Elevated serum calcitriol concentrations do not fall in response to hyperphosphatemia in familial tumoral calcinosis.

Five affected members in two branches of a Druze Arab kindred presented with calcified deposits in or about the hips and knees, indicating the diagnosis of tumoral calcinosis. Serum vitamin D metabolite concentrations, immunoreactive parathyroid hormone, and the tubular reabsorption of phosphate were measured in three affected siblings, as well as in their parents and an unaffected sibling. Normocalcemia and hyperphosphatemia with an elevated tubular maximum for phosphate per glomerular filtration rate were found in the affected patients. Levels of serum immunoreactive parathyroid hormone were normal, and the calcitriol value (1,25-dihydroxyvitamin D) was normal or elevated in the three affected patients. A trial of a low-phosphorus diet and oral aluminum hydroxide gel did not lower serum phosphate levels or improve the calcified deposits. These findings suggest that serum calcitriol values do not decline in response to hyperphosphatemia in tumoral calcinosis and that hyperphosphatemia with elevated tubular reabsorption of phosphate is a constant feature of this disorder because the kidney fails to excrete the increased filtered load of phosphate.

Adult↗
PubMed1985

Cross resistance to esters of methotrexate in a doxorubicin-resistant subline of P388 murine leukemia.

Resistance to methotrexate was developed by continuous exposure of P388 murine leukemia cells in vitro to increasing concentrations of methotrexate up to 1 X 10(-7) M. Once established, the resistance to methotrexate was stable. This was also found in methotrexate-resistant cells that were maintained in methotrexate-free medium for more than 4 months. The sensitivity of the methotrexate-resistant P388 cells to doxorubicin was comparable to the sensitivity measured in the parental cell line. Another methotrexate-resistant cell line was developed, in a similar way, from doxorubicin-resistant P388 cells. This methotrexate-resistant cell line maintained its original resistance to doxorubicin. In methotrexate-sensitive cells, the dimethyl and dibutyl esters of methotrexate were 18.3- and 2.7-fold less active, respectively, than the free methotrexate in inhibiting cell growth. In methotrexate-resistant cells, the inhibitory effect of the methotrexate dimethyl ester was similar to its effect on the methotrexate-sensitive cell line. The activity of the methotrexate dibutyl ester was 3.3-fold lower than its activity in the parental cell line. However, both esters of methotrexate were much more active than free methotrexate in the methotrexate-resistant cell line. In the doxorubicin-resistant cell line, the activity of free methotrexate was comparable to its activity in the doxorubicin-sensitive parent cell line. However, this cell line was remarkably resistant to the ester analogs of methotrexate. The clinical implications of these findings are discussed.

Animals↗
PubMed1984

Cystine accumulation and clearance in normal and cystinotic fibroblasts exposed to cystine dimethyl ester.

Exposure of cultured skin fibroblasts of normals and cystinotic patients to 0.5 mmol/l[35S]cystine dimethyl ester for 30 min resulted in an accumulation of cystine in excess to that naturally occurring in cystinotic skin fibroblasts. These equal levels of cystine accumulation achieved in both cystinotic and normal cells, permitted comparative experiments to look for differences in cystine disposal between normal and cystinotic cells. Cystinotic fibroblasts demonstrated very low cystine clearance with a lower ratio of cysteine-N-ethylmaleimide to cystine than normal. The results on cystinotic fibroblasts are consistent with those observed in leucocytes, suggesting that fibroblasts can be useful in further studies to elucidate the clearance defect of cystine in cystinosis as well as its potential in antenatal diagnosis.

Cells, Cultured↗
PubMed1984

Comparative study of cystine clearance in cystinotic and I-cell fibroblasts upon exposure to cystine dimethyl ester.

I-cell fibroblasts can accumulate cystine at levels comparable to those seen in homozygous cystinotic fibroblasts. Cystine accumulation in cystinosis is accounted for cystine clearance defect in situ. To unravel the question whether the same clearance defect or two different mechanisms cause cystine accumulation in I-cell disease, we used the cystine loading technique upon exposure of skin fibroblasts to radioactive cystine dimethyl ester. Normal, cystinotic and I-cell fibroblasts were exposed to radioactive cystine dimethyl ester, and the clearance of the generated radioactive cystine was measured. Cystinotic cells showed a marked defect in cystine clearance in situ, as compared to normal fibroblasts. In I-cell fibroblasts, we observed slow hydrolysis of cystine dimethyl ester to cystine, indicating low esterase activity, but no defect in clearance of the generated cystine. Cysteine production from the exogenous cystine dimethyl ester, presumably by cytoplasmic hydrolysis of the generated cystine, is normal in I-cell fibroblasts. Thus, our results indicate that, unlike cystinosis, there is no cystine clearance defect in situ for cystine in I-cell disease, and probably unrelated mechanisms cause cystine storage in cystinosis and I-cell disease.

Cell Line↗