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Biomedical subjects

J Horowitz

Publications and source records attributed to J Horowitz.

At least 73 records · Page 4Linked to original sources
PubMed1989

Induction of de novo synthesis of crystalline lenses in aphakic rabbits.

The mammalian lens, like other ectodermal tissues, can regenerate itself given the proper environment. Endocapsular phacoemulsification of adult rabbit lenses was performed. A lens capsular bag with posterior and anterior lens capsule relatively intact was left in the eye. Regrowth of material in the capsular bag was followed by slit lamp biomicroscopy and photography over a 12-month period. Histopathology of the new material showed regions of relatively normal epithelial cells and lens fibers as well as regions where growth was irregular. All major lens crystallin classes were present in the regenerated lens. Several specific crystallin subunits, known to arise by post-translational modification of primary gene products, were absent or present in abnormally low concentrations.

Animals↗
PubMed1989

Toxic waste: behavioral effects of an environmental stressor.

This study examines the stress-related behavioral effects that may be associated with living near an ambient stressor: a toxic-waste landfill. Results are based on a telephone survey of 426 persons living in three distance strata from the landfill (within 1 1/2 miles, 1 1/2 to 5 miles, and 5 to 10 miles). The instrument was adapted from the Hopkins Life Checklist (SCL-90) and from surveys used by researchers studying the effects of the Three Mile Island nuclear accident. No significant differences were found across area or amount of stimuli exposure on the dependent variables of bodily effects, anger-hostility, and demoralization. Scattered effects across age, sex, educational level, and home ownership (v rental) occurred; however, these could not be attributed solely to the landfill.

Adaptation, Psychological↗
PubMed1989

All perforated ulcers are not alike.

To determine if ulcer location and other clinical factors affect the hospital course and early outcome of patients with perforated peptic ulcers in the decade since the introduction of H2 receptor antagonists, the records of 80 patients with perforated peptic ulcers were analyzed. Demographic factors, clinical features, and the outcome of patients with duodenal ulcer perforation were similar to patients with prepyloric ulcer perforation. In contrast, patients with gastric ulcer perforation had differing characteristics from the group with perforated pyloroduodenal ulcers. Overall, NSAID use preceded perforation in one half of the patients; severe coexisting medical illness and a short interval of symptoms before perforation were seen in more than one half of patients. Gastric ulcer location, hemodynamic instability, greater degree of peritoneal contamination, and larger ulcer size were factors associated with increased rates of mortality. Overall mortality rate was 12.5% and rate of morbidity was 33%. Oversewing with or without omental patch was the operation most commonly employed by a diverse group of surgeons.

Adult↗
PubMed1989

Plasma atrial natriuretic peptide in patients with acute myocardial infarction: effects of streptokinase.

Plasma concentrations of immunoreactive atrial natriuretic peptide (mean (SEM] were measured in 135 patients admitted to two coronary care units with myocardial infarction, ischaemic chest pain, or non-ischaemic chest pain. Concentrations were significantly higher in patients with acute myocardial infarction not treated with systemic thrombolysis (60.4 (14.3) pg/ml) than in patients with non-ischaemic chest pain (21.1 (4.3) pg/ml). Patients with ischaemic chest pain had intermediate values (39.3 (7.1) pg/ml). Patients with acute myocardial infarction treated with intravenous streptokinase had normal concentrations of plasma atrial natriuretic peptide (20.2 (3.6) pg/mg), which were significantly lower than those in patients with myocardial infarction not given streptokinase. These changes could not be explained by factors such as age, pre-existing hypertension, renal dysfunction, or cardiac failure, nor treatment other than streptokinase. Raised plasma concentrations of atrial natriuretic peptide in acute myocardial infarction may be a homoeostatic response acting to reduce atrial pressures by natriuresis, diuresis, and venodilatation. The lower concentrations of atrial natriuretic peptide in patients with acute myocardial infarction treated with streptokinase may reflect a short term beneficial haemodynamic effect of streptokinase.

Angina Pectoris↗
PubMed1989

Interleukin 6 gene expression in normal and neoplastic B cells.

In the present report we demonstrate that the IL-6 gene is expressed in anti-Ig-activated and neoplastic B cells. After activation with anti-Ig, splenic B cells rapidly expressed IL-6 mRNA with peak expression occurring at 4 h and declining rapidly thereafter. In an attempt to exclude that the IL-6 mRNA expression was in non-B cells, T cells and monocytes were extensively depleted. In this highly purified B cell population, IL-6 mRNA was retained, whereas the expression of the T cell- and monocyte-restricted CD2 and CD14 genes was nearly undetectable. These results are consistent with the conclusion that activated B cells express IL-6 mRNA. Because we found IL-6 mRNA expression in normal activated B lymphocytes, we examined the expression of IL-6 mRNA in B cell neoplasms. 11 of 25 non-Hodgkins B cell lymphomas and 4 of 4 myelomas and plasma cell leukemias expressed IL-6 mRNA, whereas only 1 of 19 B cell leukemias was positive. To exclude that IL-6 mRNA expression in neoplastic B cells was the result of contaminating non-B cells, T cells and monocytes were extensively depleted from the tumor specimens. In the three IL-6-positive tumor samples depleted of T cells and monocytes, IL-6 mRNA expression was retained in all cases. These observations provide support for the idea that the IL-6 gene is expressed in normal activated and neoplastic B cells.

Adult↗
PubMed1988

Partial assignment of resonances in the 19F nuclear magnetic resonance spectra of 5-fluorouracil-substituted transfer RNAs.

Features of the 19F nuclear magnetic resonance (NMR) spectra of three purified 5-fluorouracil-(FUra-) substituted Escherichia coli tRNAs, tRNA(1Val), tRNA(mMet), and tRNA(fMet), are compared. Each of the tRNA species can be resolved into two isoaccepting forms, A and B, whose 19F NMR spectra differ in the shift of one peak from the 4.5 to 4.8 parts per million (ppm) range (FUra = O) in the spectrum of isoacceptor B upfield to ca. -15 ppm in that of isoacceptor A. Because the sequences of the two isoacceptors of each tRNA differ only at one position in the D loop, that normally occupied by a dihydrouridine residue, we assign the 4.5 ppm peak in the spectrum of fluorine-labeled tRNA(1Val) to FUra17 and the resonance at 4.6 ppm in the spectrum of fluorouracil-substituted tRNA(mMet) to FUra20. A reciprocal 19F[19F] nuclear Overhauser effect is observed between the downfield peaks A and B in the 19F NMR spectrum of 19F-labeled tRNA(1Val). Assuming that fluorine-labeled tRNA(1Val) has a structure similar to that of yeast tRNA(Phe), only FUra54 and -55 are close enough (4-5 A) to give an appreciable 19F homonuclear Overhauser effect. Peaks A and B have therefore been assigned to FUra54 and -55. As the temperature is raised from 30 to 45 degrees C, the intensity of peak B (6.6 ppm) in the spectrum of 19F-labeled tRNA(1Val) gradually shifts upfield to 6.4 ppm (Tm = 36 degrees C), indicating a temperature-dependent slow exchange of the corresponding 5-fluorouracil residue between two magnetically distinct environments.(ABSTRACT TRUNCATED AT 250 WORDS)

Escherichia coli↗
PubMed1988

Septal rupture: effect of oxygen administration.

A patient with interventricular septal rupture as a complication of myocardial infarction was studied to determine whether varying the concentration of inspired oxygen would alter the magnitude of intracardiac shunt. A significant correlation was found showing that high concentration of inspired oxygen results in increased left to right shunting probably due to systemic vasoconstriction and pulmonary vasodilatation.

Combined Modality Therapy↗
PubMed1988

Dermabrasion of traumatic tattoos: simple, inexpensive, effective.

In this article we describe the use of an electrosurgical cautery tip scratch pad for the treatment of traumatic (adventitious) tattoos. This inexpensive item is available in most surgical operating rooms. The pad is flexible yet firm and obviates the need for power equipment. Most important, the technique is simple, easy to learn, and highly effective.

Blast Injuries↗
PubMed1988

Thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome in three siblings.

Two brothers and one sister had three variants of thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome (the 'TTP-HUS' complex). The sister had a chronic fatal variant of thrombotic thrombocytopenic purpura with severe neurological manifestation. One brother had a chronic relapsing disease but the kidneys were not affected, and the other brother had haemolytic uraemic syndrome. This occurrence in one family supports the hypothesis that haemolytic uraemic syndrome and thrombotic thrombocytopenic purpura are actually two variants of the same disease.

Child, Preschool↗
PubMed1988

[Improvement of a chromosomal technic for trophoblast biopsy. Apropos of 200 cases].

The authors report their experience of 200 cases of prenatal diagnosis by biopsy of chorionic villi. Because they could not consistently obtain good quality chromosome banding, they propose a modification of the conventional direct method. The addition of methanol in sufficient proportions to the nuclear suspension makes it possible to obtain spontaneous spreading on slides heated to 65 degrees C and eliminates the problems of mechanical spreading.

Adult↗
PubMed1988

Serum and synovial fluid levels of serum amyloid A protein and C-reactive protein in inflammatory and noninflammatory arthritis.

Serum and synovial fluid (SF) levels of serum amyloid A (SAA) and C-reactive protein (CRP) were measured in 46 cases of various inflammatory arthritis (Group 1), and in 40 cases of noninflammatory arthritis: 18 cases of osteoarthritis (Group 2) and 22 cases of traumatic arthritis (Group 3). Serum and SF SAA levels were markedly elevated in Group 1: 126.4 micrograms/ml +/- 19.2 SEM and 46.4 micrograms/ml +/- 10.5 SEM, respectively; moderately elevated in Group 2: 10.1 micrograms/ml +/- 2.9 SEM, 4.0 micrograms/ml +/- 1.1 SEM and moderately elevated in Group 3: 10.4 micrograms/ml +/- 1.2 SEM, 4.0 micrograms/ml +/- 1.2 SEM, respectively. Serum/SF SAA ratios were similar in all 3 groups and ranged between 2.52-2.72. In comparison to SAA, the increment of serum and SF CRP above normal levels was moderate. A positive strong correlation was found between serum SAA and serum CRP: r = 0.64 (p less than 0.001) and between SF SAA and SF CRP: r = 0.59 (p less than 0.0001). SF SAA did not correlate with the number of SF white blood cells but did correlate with the percent of SF polymorphonuclear cells: r = 0.23 (p less than 0.05).

Arthritis↗