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Biomedical subjects

C Vega

Publications and source records attributed to C Vega.

48 records · Page 3Linked to original sources
PubMed1987

A teaching attachment for retinoscopy.

A teaching attachment for a conventional streak retinoscope allows a second observer to view the retinoscopic reflex during retinoscopy. The device weighs 200 grams and is attached to the retinoscope by a semi-flexible, rotatable linkage. A beam splitter, one-power telescope, and erecting mirror form a displaced aerial image of the retinoscope peephole for the observer. With identical retinoscopic reflexes observed through the actual peephole and its aerial image, the device can be used to teach basic retinoscopy techniques to new refractionists, or to demonstrate subtle reflexes to more experienced observers.

Equipment Design↗
PubMed1985

Effect of aminoglycosides on the disposition of thyroid hormones and thyroglobulin.

Our study was designed to confirm the potential effects of three aminoglycosides on the disposition of thyroid hormones. Twenty-seven patients diagnosed with either cellulitis (n = 19), chronic osteitis (n = 4), or an abscess (n = 4) were selected. Thirteen patients received tobramycin, 60 to 100 mg iv q. 8 h., plus cloxacillin, 1 gm iv q. 4 h.; seven patients received netilmicin, 40 to 120 mg iv q. 8 h., plus cloxacillin, 1 gm iv q. 4 h.; and seven patients received either cloxacillin, 1.5 gm iv q. 4 h., or cefoperazone, 2 to 4 gm iv q. 12 h. for at least 7 days. Another group of six normal subjects received neomycin, 0.5 gm po q. 6 h. for 7 days. All these subjects had normal thyroid function before antibiotic dosing and none had thyroid function abnormalities. Tobramycin and cloxacillin/cefoperazone did not influence thyroid function. Netilmicin decreased the total serum concentrations of triiodothyronine (T3) from 114 +/- 9 to 75 +/- 7 ng/dl (P less than 0.01), probably because of increased clearance, as the T3 free fraction increased from 0.43% +/- 0.02% to 0.49% +/- 0.02% (P less than 0.05). Thyroxine (T4) and reverse T3 (rT3) levels were not affected. Neomycin decreased T3 levels from 104 +/- 8 to 92 +/- 7 ng/dl (P less than 0.05) and the serum concentrations of thyroglobulin from 17.3 +/- 2.0 to 11.7 +/- 2.0 ng/ml (P less than 0.001). Because T4 and rT3 levels did not change, our results suggest that neomycin may have directly affected the gland. We conclude that some aminoglycosides can alter the disposition of thyroid hormones.

Adult↗
PubMed1984

Glycogenolytic substances, hepatic and systemic lactate, and food intake in rats.

Changes in hepatic lactate and glucose and systemic blood lactate produced by intraperitoneal injections of epinephrine, isoproterenol, glucagon, and insulin showed a high correlation (r = 0.9) with the changes in food intake elicited by the same substances. The changes in systemic blood glucose showed no correlation with the changes in feeding, which suggests that central glucoreceptors are not playing an important role in the observed changes in feeding. The intramuscular epinephrine had no significant effect on food intake, in spite of changes in systemic and hepatic lactate and glucose similar to those elicited by intraperitoneal epinephrine. However, intramuscular epinephrine had no hepatic glycogenolytic effect. This suggests that the changes in glucose and lactate elicited by intraperitoneal epinephrine result from hepatic glycogenolysis, whereas the changes elicited by intramuscular epinephrine result from muscular glycogenolysis and inhibition of insulin. Thus hepatic glucose and lactate are good predictors of feeding only when they are produced endogenously by hepatic glycogenolysis. It was concluded that hepatic lactate cannot be the substance sensed by hepatic metabolic receptors. However, due to a possible change in the hepatic lactate-to-pyruvate ratio elicited by intraperitoneal epinephrine, hepatic pyruvate may still be correlated with feeding during the action of both intramuscular and intraperitoneal epinephrine. Therefore the hypothesis that pyruvate is the substance monitored by hepatic metabolic receptors should be tested.

Animals↗
PubMed1984

[Cutters and drillers: 2 different coal pneumoconioses?].

The radiographs of 393 coal-cutters (or hewers) and 187 drillers were read independently by two pneumoconiosis experts following the complete 12 grade classification (BIT 1980). The two groups were comparable for age, tobacco and alcohol consumption, and respiratory symptoms but the VEMS was lower in he drillers (p = 0.05). There were significant radiological differences between the groups as follows: with the coal-cutters predominantly type "p" opacities and Category 1; in the drillers "q" and "v" opacities and category 3 were most frequent, and there were a large number of pseudo-tumoral masses and signs of hyperinflation. The two groups have a quantitative and qualitative differences in exposure; it is necessary to interpret the results as two different types of pneumoconiosis, although there are intermediate types. The coal cutters have coal-workers pneumoconiosis in the strictest sense, while the drillers have silicosis with mixed dusts, the latter being more aggressive and incapacitating. One should take account of the two types in epidemiological evaluations in coal miners. It helps to explain certain contradictory results.

Coal Mining↗
PubMedDate not supplied

Glomangiosarcoma of the hypothenar eminence: a case report.

Glomangiosarcoma is an exceptionally rare soft tissue tumor. It tends to appear as a painful nodule located in the subcutaneous tissue. There are only two cases described on the hand before instead of the benign glomus tumor is usually located at this level. Histochemically the glomangiosarcoma shows features that remind a benign glomus tumor, except for the malignant glomus tumor arising de novo. This neoplasm is considered a low grade malignant tumor with tendency to local recurrence, though metastasis have been reported. We report the case of a 36 year-old -woman with a glomangiosarcoma in a glomus tumor in the hypotenar eminence. The treatment was a local complete excision and there was no signs of recurrence after 18 months.

Adult↗