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Biomedical subjects

S Podos

Publications and source records attributed to S Podos.

9 recordsLinked to original sources
PubMed1994

Studies of the ocular pulse in primates.

Ocular pulse amplitude (OPA) and intraocular pressure (IOP) were measured in groups of human subjects with primary open-angle glaucoma (POAG), ocular hypertension (OHT), low-tension glaucoma (LTG), retinal degenerations (RD), in OHT volunteers treated with single doses of 2% epinephrine, 4% pilocarpine, 0.5% timolol or 1% p-amino-clonidine, and in normal subjects before and after exercise. Compared to normal controls, OHT subjects showed significantly higher IOP and OPA, while OPA was significantly lower in ocular normotensive LTG and RD subjects groups. All drug treatments lowered IOP in OHT subjects, but did not change OPA significantly. Exercise in normal volunteers increased calculated ocular perfusion pressure by 22.5%, lowered IOP by 32%, but showed no significant change in OPA. When IOP was elevated > or = 5 mmHg in lasered monkey eyes peak pulse volume (PPV) was increased significantly in the unlasered eyes. Epinephrine 2% or 1% p-aminoclonidine lowered IOP moderately with no change in PPV, while treatment with 4% pilocarpine or 0.5% timolol reduced IOP and increased PPV significantly. The findings suggest that LTG may be associated with an ocular vascular abnormality. OPA in OHT or normal human subjects did not change when IOP was decreased by antiglaucoma drug treatments or exercise, respectively. These results indicate that OPA may be physiologically autoregulated in human subjects with IOPs in the 11-21 mmHg range. However, laser-induced glaucomatous monkey eyes with higher IOP (30-35 mmHg) did not autoregulate, but showed a low peak pulse volume, which increased when IOP was reduced 5 mmHg or more by means of antiglaucoma drug treatment.

Adult↗
PubMed1990

Conditional mutations occur predominantly in highly conserved residues of RNA polymerase II subunits.

Conditional mutations in the Saccharomyces cerevisiae RNA polymerase II large subunit, RPB1, were obtained by introducing a mutagenized RPB1 plasmid into yeast cells, selecting for loss of the wild-type RPB1 gene, and screening the cells for heat or cold sensitivity. Sequence analysis of 10 conditional RPB1 mutations and 10 conditional RPB2 mutations revealed that the amino acid residues altered by these distinct mutations are nearly always invariant among eucaryotic RPB1 and RPB2 homologs. These results suggest that RNA polymerase mutants might be obtained in other eucaryotic organisms by alteration of these invariant residues.

Amino Acid Sequence↗
PubMed1985

Prevalence and clinical associations of intraocular pressure changes in Graves' disease.

We investigated an unselected series of 55 patients with treated or untreated hyperthyroid Graves' disease, assessing their clinical and laboratory status and ophthalmological findings, including the difference in intraocular pressure (dIOP) between upgaze and straight gaze using applanation tonometry. An increased dIOP (greater than 2 mm Hg) was detected in only 22% of Graves' patients [who had a mean dIOP of 3.5 +/- 1.6 (+/- SEM) mm Hg]. dIOP did not correlate with age, sex, age at disease onset, duration of disease, mode of antithyroid treatment, or thyroid function testing at the time of examination. Mean Hertel exophthalmometry measurements in patients with a dIOP greater than 2 mm Hg were 22.0 +/- 2.9 mm compared with 18.4 +/- 3.7 mm in those with a dIOP less than 2 mm Hg (P less than 0.027, by Wilcoxon rank sum test). Only 58% of patients with increased dIOP had clinical exophthalmos, but all had other evidence of Graves' eye disease. Computed tomographic scanning revealed significant proptosis and/or orbital muscle involvement in all of the patients with increased dIOP.

Adult↗
PubMed1983

Pattern electroretinograms and visual-evoked potentials in glaucoma and multiple sclerosis.

Steady-state visual-evoked potentials and electroretinograms were simultaneously recorded in four patients with glaucoma and in five patients with multiple sclerosis. The stimuli included a homogenous field and a 2.3 cycles per degree sinusoidal grating that were counter-phase modulated at the rate of 7.5 Hz. We used narrow bandwidth spectral analysis to measure the response amplitudes and signal-to-noise ratios. Transient pattern visual-evoked potentials (1 Hz) were also measured for latency in each eye. We found abnormal pattern electroretinograms, based on the absence of a significant second harmonic component, in three of the four glaucomatous eyes although the homogenous field electroretinograms were normal. In the patients with multiple sclerosis, the pattern electroretinograms were abnormal in two eyes, but the transient visual-evoked potential latency had the highest diagnostic yield (seven of ten eyes).

Adult↗
PubMed1978

Retail cost of antiglaucoma drugs in two cities.

Volunteer shoppers purchased antiglaucoma medications dispensed from prescriptions written according to generic and brand-name products in Manhattan and in the St. Louis area. All drugs obtained were more expensive in Manhattan than in St. Louis. No significant cost difference was found between generic and brand-name items in either city, but only in a few instances were generic drugs actually dispensed. No difference in overall price was found between pharmacies located in better and poorer neighborhoods in Manhattan or between pharmacies located in urban, suburban, or rural areas in St. Louis. A white shopper paid significatnly lower retail prices than did a Hispanic shopper in Manhattan, particularly in better neighborhoods. The range of prices in each city for all drugs studied was greater than twofold. Pharmacies offering more patient services tended to charge higher prices, but frequently, pharmacies did not actually offer the services they advertised.

Drug Prescriptions↗