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Biomedical subjects

R Stein

Publications and source records attributed to R Stein.

At least 289 records · Page 16Linked to original sources
PubMed1981

Intravenous prostacyclin in thrombotic thrombocytopenic purpura.

A therapeutic trial of prostacyclin (PGI), was done in a patient with thrombotic thrombocytopenic purpura resistant to treatment with antiplatelet drugs and plasmapheresis. Despite marked thrombocytopenia and continued treatment with aspirin, sulfinpyrazone, and dipyridamole, the urinary excretion of 2,3-dinor-thromboxane B2, a major thromboxane urinary metabolite, was within the normal range (90.3 to 368 pg/mg creatinine) at 96 pg/mg creatinine. Because of its potent antiaggregatory properties and the possibility of a defect in endogenous PGI2 production in thrombotic thrombocytopenic purpura, synthetic PGI2 (4 to 10 ng/kg-1 . min-1) was infused intravenously, first for 72 hours and then continuously for 18 days. Prostacyclin markedly reduced the excretion of 2,3-dinor-thromboxane B2, and the platelet count rose steadily to reach 100 000/mm3 by the eighth day of the second infusion. The patient remains in clinical remission, on no therapy, 7 months later. A controlled evaluation of PGI2 in thrombotic thrombocytopenic purpura is warranted. Apparent therapeutic failure in previous cases may have resulted from inadequate prolongation of PGI2 infusion.

Adult↗
PubMed1981

[Echocardiographic measurements of hemodynamic effects and pharmacokinetics of prenalterol (author's transl)].

The dose-dependent haemodynamic effects and pharmacokinetics and parenteral prenalterol (0.5-10 microgram/kg/min), a new cardioselective beta-1-adrenoceptor agonist, have been studied in 10 healthy volunteers by computed echocardiography. Prenalterol induced a dose-dependent strong and persistent increase in contractility (FV 46%, VCF70 64%, STI 12%), heart index (46%) and heart rate (27%) and a moderate not significant decrease in VED (14%). Afterload and mean arterial blood pressure was nearly unaltered. The hemodynamically effective threshold concentration of prenalterol in plasma was 20-30 nmol/l, the mean value of maximum concentration 493 nmol/l; 1 hour after stopping the infusion prenalterol plasma level was about 90 nmol/l. A strong linear correlation between the haemodynamic alterations and the logarithm of prenalterol plasma concentrations was not apparent.

Adolescent↗
PubMed1981

A comparison between auditory and visual evoked responses in multiple sclerosis.

Sixteen patients, 6 males and 10 females, all fullfilling the criteria of clinically definite multiple sclerosis, were examined. All but one patient presented anamnestic data or clinical findings suggesting a previous or present brain stem lesion. The result obtained by visual (VER) and auditory evoked responses (ABR) were compared. In all cases abnormal VER were observed. Abnormal ABR were only recorded in 9 of the 16 patients. Consequently VER is the method of choice in establishing the multiple sclerosis diagnosis.

Adolescent↗
PubMed1980

Effect of tunicamycin and cycloheximide on the secretion of acid hydrolases from I-cell cultured fibroblasts.

I-cell cultures fibroblasts secrete excessive amounts of N-acetyl-beta-D-hexosaminidase and alpha-L-fucosidase into the culture media as compared with normal fibroblasts. Addition of tunicamycin or cyd [14C]leucine (40--50%) into trichloroacetic acid-precipitable material decreased the secretion of these I-cell hydrolases to normal values within 24 h, but had no effect on the secretion of acid hydrolases from normal fibroblasts. These results indicate that I-cell cultured fibroblasts secrete at least two types of acid hydrolases: one is tunicamycin- and cycloheximide-sensitive and constitutes the greater proportion of the secreted hydrolases, and a smaller proportion is insensitive to tunicamycin and cycloheximide, similar t9 the acid hydrolases secreted by normal cultured fibroblasts.

Cells, Cultured↗
PubMed1980

Hypochloremic alkalosis in infants associated with soy protein formula.

Thirteen infants, 2 to 10 months of age, developed hypochloremic alkalosis (serum chloride 59 to 92 mEq/l) while taking Neo-Mull-Soy (Syntex), a soy-based formula low in chloride (measured to be 0 to 2 mEq/l) but with considerable potassium citrate. Range of symptoms included lethargy, anorexia, mild spitting up, diarrhea, hematuria, and growth failure. Urine chloride excretion was less than 3 mEq/l. Plasma renin activity or aldosterone, measured in six infants, was elevated. All responded promptly to supplemental salt. One infant receiving Neo-Mull-Soy redeveloped alkalosis when supplemental salt was discontinued. Two of nine apparently normal infants receiving Neo-Mull-Soy also had hypochloremia (85, 86 mEq/l). Three of four receiving Prosobee (Mead Johnson; Cl content 7 mEq/l) had urine chloride concentration less than 20 mEq/l. The chloride content of some infant formulas is insufficient to offset salt losses following mild stress.

Alkalosis↗
PubMed1980

Methylation of foreign DNA sequences in eukaryotic cells.

The herpesvirus thymidine kinase gene has been used to introduce foreign DNA sequences into mouse L cells by DNA-mediated gene transfer. These inserted genes were then assayed for methylation at the specific sequence C-C-G-G by using the restriction enzyme isoschizomers Hpa II and Msp I. Despite the fact that 70% of the cellular C-C-G-G sites are methylated, herpesvirus sequences, plasmid DNA, and growth hormone gene DNA were found to remain unmethylated in 90% of the clones that contain these genes. DNA that had been methylated in vitro with Hpa II methylase was also inserted into L cells. The presence of this modification in the vector DNA did not, however, guarantee that these sequences remained methylated in the recipient clones. Only 10% of all transformed clones were found to contain methylated C-C-G-G sequences in the vector DNA, and these modifications were stable for 25-50 generations. Hha I and Mbo I were used to probe for methyl groups at these restriction sites, but none of the inserted sequences acquired these modifications. These results are discussed in relation to various models put forth to explain the process of methylation in eukaryotic cells.

DNA↗
PubMed1980

Use of human fibroblast-derived (beta) interferon in the treatment of epidemic adenovirus keratoconjunctivitis.

Topical application of human fibroblast-derived (beta) interferon (HulFN-beta) has been used in treatment of epidemic keratoconjunctivitis due to adenovirus. Patients received a total of 1-2 x 10(5) reference units of HulFN-beta per day, divided into 8-10 drops. Control patients received corticosteroid therapy or a placebo containing human serum albumin, with the same administration schedule. The severity and evolution of symptoms was analyzed according to a number of clinical criterias. The results indicate that in the interferon-treated group the length of the disease was reduced from an average of 27 days to 6.5 days. The number of cases in which keratitis occurred as a complication of the disease was reduced in the interferon-treated group to 10%, as opposed to 57% in the control group. Doses of interferon lower than 5 x 10(4) units per day, were not effective to prevent keratitis.

Adenoviridae Infections↗
PubMed1979

Genetic marker for insulin-dependent diabetes mellitus.

A rare genetic type (Bf F1) of properdin factor B is found in 22.6% of patients with insulin-dependent diabetes mellitus but in only 1.9% of the general population, yielding a relative risk of 15.0. This indicates that a genetic locus for insulin-dependent diabetes mellitus is very close on chromosome 6 to Bf, and that Bf F1 is a marker for nearly 1 out of 4 insulin-dependent diabetic patients.

Adult↗
PubMed1979

Detection and partial sequence analysis of gastrin mRNA by using an oligodeoxynucleotide probe.

We have used a specific deoxyoligonucleotide probe to detect gastrin mRNA in poly(A)-enriched RNA preparations from hog antrum. The nucleotide sequence of the oligonucleotide, d(C-T-C-C-T-C-C-A-T-C-C-A), was deduced from the unique amino acid sequence Trp-Met-Glu-Glu of gastrin. When used with hog antral RNA, the dodecanucleotide is an effective primer for the synthesis of gastrin-specific cDNA as judged by nucleotide sequence analysis of cDNA isolated by polyacrylamide gel electrophoresis. We have determined an 81-nucleotide sequence corresponding to the region of the gastrin mRNA that codes for the known amino acid sequence of the G34 progastrin intermediate species, and we have demonstrated the presence of two consecutive basic residues preceding the G34 sequence in the prohormone. Hybridization of gastrin cDNA or synthetic dodecanucleotide to hog antral RNA separated by gel electrophoresis on agarose gels in the presence of methylmercuric hydroxide indicates that the mRNA coding for gastrin is about 620 nucleotides long. These results suggest that the gastrin precursor peptide contains 110-140 amino acids. This method should be of general application for detection and characterization of mRNAs corresponding to proteins of known amino acid sequence.

Animals↗
PubMed1978

Leaking filtering blebs.

Histologic examination of ten leaking filtering blebs revealed an epithelial tract running from the surface of the bleb down to the episclera in eight cases. These epithelial tracts were considered the real cause of the persistent leakage.

Adult↗
PubMed1978

Primary retinal dysplasia transmitted as X-chromosome-linked recessive disorder.

The familial occurrence of retinal dysplasia in five affected male children suggested X-chromosome-linked recessive inheritance. The clinical features were childhood onset, severe visual impairment, head posture, nystagmus, and strabismus. The ophthalmoscopic findings varied in shape and extension; they ranged from retinal folds to dysplastic tissue covering the posterior pole or gliosis with tumor-like protrusion in the vitreous. The marked variability of the retinal findings was paralleled by the visual acuity, which ranged from some vision to blindness. Electroretinograms coordinated well with ophthalmoscopic observations. Of the five mothers, who are the presumed heterozygous carriers, two showed retinal changes.

Blindness↗