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Biomedical subjects

S Goldberg

Publications and source records attributed to S Goldberg.

At least 235 records · Page 13Linked to original sources

Increased mutation rates in doubly viral transformed Chinese hamster cells.

An untransformed parental Chinese hamster cell line, one polyoma transformed clone, and two clones containing both SV40 and polyoma DNA were tested for the appearance of variants resistant to 6-thioguanine or oubain. The frequency of such variants was found to be highest in doubly transformed cells. The mutation rate at these loci was correlated with the level of transformation. The mutants observed were stable and had low reversion frequencies with no gross cytogenetic changes. These results establish a quantitative basis for the evaluation of phenotypic variability observed in transformed cell populations.

Animals↗

Coronary hemodynamic and myocardial metabolic alterations accompanying coronary spasm.

Arterial pressure, coronary sinus blood flow with the thermodilution technique and calculated coronary vascular resistance were measured and coronary arteriography performed at rest and after the administration of ergonovine in 14 patients with atypical chest pain (group 1) and 6 patients with variant angina (group II). Mild diffuse narrowing of the left coronary bed in group I was not accompanied by S-T segment shifts, and coronary vascular resistance did not change significantly. In contrast, severe focal spasm (greater than 90 percent narrowing) of the left anterior descending coronary artery in group II patients was accompanied by S-T elevation and a marked overall increase in coronary vascular resistance (from 0.65 +/- 0.07 to 1.14 +/- 0.10 mm Hg/ml per min) (P less than 0.005). In addition, the myocardial arteriovenous oxygen difference increased and net lactate extraction changed to lactate production in the two patients in group II in whom these measurements were made. Thus, thermodilution coronary sinus blood flow measurement may be a sensitive method for detecting primary increases in coronary vascular resistance due to a high grade focal spasm in the left anterior descending coronary artery.

Adult↗

Factors contributing to altered left ventricular diastolic properties during angina pectoris.

Mechanisms involved in the altered left ventricular (LV) diastolic properties during angina were studied in 26 patients with coronary artery disease. Angina was induced by rapid atrial pacing and measurements were made at rest and during angina in the immediate post-pacing period. No changes occurred in heart rate (71 +/- 3 to 73 +/- 3 beats/min, NS) or right ventricular (RV) end-diastolic pressure (10 +/- 1 to 11 +/- 1 mm Hg, NS), while significant increases occurred in LV end-diastolic pressure (17 +/- 1 to 30 +/- 1 mm Hg, p less than 0.01), aortic diastolic pressure (74 +/- 3 to 80 +/- 3 mm Hg, p less than 0.01), coronary sinus blood flow (133 +/- 15 to 212 +/- 32 ml/min, p less than 0.01), and the time constant (T) of LV pressure fall in early diastole (43 +/- 2 to 58 +/- 4 msec, p less than 0.01). Despite the rise in arterial pressure, a significant fall was observed in peak negative dP/dt (1961 +/- 106 to 1751 +/- 80 mm Hg/sec, p less than 0.01). Changes in RV end-diastolic pressure do not explain the increased LV end-diastolic pressure during angina. Increased aortic pressure and coronary blood flow may contribute, but the simultaneous fall in peak negative dP/dt and rise in T suggest that impaired ventricular relaxation is an important factor contributing to the previously demonstrated alteration in LV diastolic properties during angina pectoris.

Angina Pectoris↗

Pyridine-silver methods for the study of optic axons in retinal whole mounts.

The optic fibers in the retinas of diverse species may be selectively stained and viewed en bloc in the embryonic and adult states. Treat the eye as follows: 1) 50% pyridine for at least 16 hr, 2) distilled water 3--4 hr, 3) 20% H2O2 until the eye is a light brown, 4) 95% ethanol overnight, 5) 1.5% AgNO3 for 2--6 days at 37 C, 6) in water, remove the vitreous, then direct 0.25% pyrogallic acid in 1.25% formalin against the retina for 2--5 secs until the optic fibers are reduced to a coffee-copper color (1--4 minutes), 7) dissect the retina and mount flat on a glass slide, 8) cover with glycerin, apply a coverslip, and fix in place with nail polish. Variants for particular species are given. The technique offers an advantage over Golgi and methylene blue methods which tend to stain only a small percentage of fibers and frequently do not work at the earliest stages of development.

Animals↗

Risks of facial plastic surgery in an otolaryngology program.

By reviewing 680 rhinoplasty, facelift, blepharoplasty, otoplasty, and chin implant procedures that were performed during a two-year period by UCLA Head and Neck Surgery (Otolaryngology) residents, we have found that the rate of major and minor complications compares favorably with that rate achieved by physicians in practice who have reported their results in the literature. Three hundred and sixty-eight rhinoplasties resulted in 1.6% major complications, 14.4% in minor complications, and 5.2% in revision surgeries. One hundred fourteen facelifts had 5.3% major complications, and 24.5% had minor complications. One hundred fifty-six blepharoplasties had no major complications, and 7.7% had minor complications; 21 chin implants resulted in no major complications, and 9.5% resulted in minor complications; and 21 bilateral otoplasties had no major complications, and 14.3% had minor complications, with 4.8% revisions.

Chin↗

Catecholamine metabolism in anorexia nervosa.

Urinary catecholamine levels were measured in 25 anorexia nervosa patients at the time when they were acutely ill with secondary depressive symptoms and again after treatment and weight gain to see whether changes in weight, activity levels, and symptoms of depression occurring during treatment might be associated with changes in urinary 3-methoxy-4-hydroxyphenylglycol (MHPG) concentrations. The latter was significantly lower in the acutely ill anorectics than in the control group. An increase in urinary MHPG concentration after treatment was significantly correlated with a decrease in depressive symptomatology. The increase in urinary MHPG level during treatment did not correlate significantly with change in patient's activity level. There seems to be a relationship between MHPG and the symptom of depression in a group of patients who do not carry a primary diagnosis of depression.

Adolescent↗

The definition of transcription units for mRNA.

The detailed analysis of TUs with purified Ad2 DNA and the analysis of TU size for the bulk HeLa cell hnRNA compared to the size of mRNA of infected and uninfected cells supports the conclusion that mRNA in mammalian cells is generally derived by the processing of primary transcripts. In the context of this volume, these results indicate that the RNA transcription products of chromatin which are related to mRNA are longer than the mRNA itself. Proper functioning of chromatin in vitro must eventually take these results into account.

Adenoviruses, Human↗

Evidence from UV transcription mapping that late adenovirus type 2 mRNA is derived from a large precursor molecule.

The UV inactivation of labeling of various late adenovirus type 2 mRNA's is as great or greater than the inactivation of labeling of the same sequences that are present in a large primary RNA transcript in the cell nucleus. Thus, the large nuclear adenovirus type 2-specific RNA appears to be the obligatory precursor of cytoplasmic mRNA. The majority of the mRNA's derived from the large precursor apparently require the synthesis of the whole nuclear molecule. A UV-sensitive target necessary for proper processing of all the mRNA's may exist near the end of the transcription unit.

Adenoviruses, Human↗

pH effect on the percutaneous penetration of lignocaine hydrochloride.

(1) The percutaneous penetration of lignocaine hydrochloride is affected in vitro by the pH; alkalinity increased the portion of the unionized drug which permeated through the lipoid outer skin membrane of guinea pigs. (2) The amount of lignocaine accumulated on the dermal side of the diffusion cell containing isotonic phosphate buffer (pH 7.4) was directly proportional to the initial concentration of the applied drug at the alkaline pH. (3) The dermal transfer rates of lignocaine into the isotonic phosphate buffer (pH 7.4) of the diffusion cell decreased with the increase in the pH of the initially applied solution on the epidermal side of the diffusion cell; the simultaneous cutaneous penetration of the alkaline buffer promoted retention of the unionized drug in the dermis. (4) Percutaneous penetration of lignocaine hydrochloride represents a dual-stage process involving dissimilar rates of clearance into cutaneous tissue and transfer from dermis to body fluids. Variations in the alkaline pH of lignocaine hydrochloride solution appear to govern the rate-limiting factor of the total percutaneous penetration; the pharmacologic action of lignocaine may thus be localized.

Animals↗

The definition of a large viral transcription unit late in Ad2 infection of HeLa cells: mapping by effects of ultraviolet irradiation.

The synthesis of Ad2-specific nuclear RNA in HeLa cells 15 hr post-infection has been examined after ultraviolet irradiation. The synthesis of RNA complementary to various segments of Ad2 DNA is decreased differentially, with the most sensitive region at the right end of the physical map and the most resistant in the region from 0 up to 0.2-0.3 (20-30% from the left end of the genome). For a given ultraviolet dose, the amount of labeled RNA homologous to various DNA fragments decreased exponentially from map position 0.2-0.3 to 1.0. These results suggest that a major transcriptional unit late in Ad2 infection is a rightward-transcribing unit between 0.0-0.3 and 1.0.

Adenoviruses, Human↗

Systolic mitral flutter, an echocardiographic clue to the diagnosis of ruptured chordae tendineae.

A new finding of fine systolic fluttering of the mitral leaflet is described in two patients with ruptured chordae tendinease and severe mitral regurgitation. The flutter is caused by the action of high-velocity blood flow upon the leaflet margin that has lost its support. The jet stream of blood evokes a high-frequency vibratory motion of the tensed leaflet as opposed to the previously described, lower frequency, less specific, diastolic flutter. This finding was not seen in the echocardiograms of 75 patients with other forms of mitral regurgitation. Systolic flutter appears to be specific for ruptured chordae tendineae.

Adult↗

Evidence from UV transcription mapping in HeLa cells that heterogeneous nuclear RNA is the messenger RNA precursor.

The effects of UV irradiation on the incorporation of [3H]uridine in HeLa (human) cell mRNA, rRNA, heterogeneous nuclear RNA (hnRNA) and early mRNA from adenovirus type 2 have been compared. The UV target size of cell mRNA is at least 3 times larger than the average size of the mRNA itself and larger than the adenovirus-2 early mRNA, which is known to derive from transcription units of about 1.5-5.0 kilobases. The UV target size of hnRNA, in contrast, is about the same as its size determined by sedimentation and overlaps with the target size of mRNA. It is concluded that most mRNA derives from a higher molecular weight hnRNA molecule.

Adenoviridae↗