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Biomedical subjects

G Gonzalez

Publications and source records attributed to G Gonzalez.

At least 127 records · Page 7Linked to original sources
PubMed1985

Tall vertebrae at birth: a radiographic finding in flaccid infants.

It has been well documented that children with severe neuromuscular disorders have tall vertebrae, presumably a consequence of altered mechanical forces. This finding was present in four neonates who were born with severe "floppy" hypotonia due to Werdnig-Hoffmann disease (two cases), nonspecific neonatal myopathy, and congenital muscular dystrophy. Fetal vertebral development is normally modified by intrauterine muscle tension and fetal activity.

Female↗
PubMed1984

Topographical distribution of the astrocytic lamellae in the hypothalamus.

The distribution of astrocytic lamellae in hamster hypothalamus was studied by electron microscopy. The astrocytic lamellae (AL) are laminar expansions of the larger astrocyte processes devoided of cell organelles. In this paper, we describe the stratified structures of astrocytic lamellae which are found according to the following patterns: surrounding neuronal somata or delimiting one soma from the other, somata from blood vessels or from neuropile. In addition, layers of astrocytic lamellae are found surrounding nervous processes, blood vessels and forming a part of the subpial layer, as well as delineating the synaptic endings. Therefore, the astrocytic lamellae form a network through the hypothalamic components. The functional significance of these structures is discussed in relation to the physiologic studies on astrocytic membranes, as a basis for the understanding of their role in neuron metabolism.

Animals↗
PubMed1982

[Socio-spatial heterogeneity and differential fertility in Bolivia. Pt. 2 (author's transl)].

In this research, based on the 1976 census, the population is simultaneously disaggregated in 3 regions, 5 urbanization levels, and 5 social sectors. This 2nd part discusses the role of intermediate variables both through the differential analysis of marital fertility and a simulation exercise with the Bongaarts model. An analysis is also made of the trends of general fertility between 1963-1972, estimated through the "own children method." The findings show that the stability of fertility in the country would be the consequence of the fertility rise in the rural areas and its decrease in the urban areas, particularly in the intermediate strata. There is indirect evidence that this decrease would mainly be the result of the growing practice of birth control. The effect of education on fertility would be strongly conditioned by the urbanization level. The higher fertility in the region of "los Llanos" would be the consequence of a higher nuptiality conditioned by the sex composition of internal migrations.

Americas↗
PubMed1982

An optical profilometer-a new instrument for the three dimensional measurement of cleft palate casts.

A technique is described for obtaining spatial characterization of three dimensional cleft palate surfaces using a noncontact optical profilometer. The operational design is discussed and an evaluation of the system is presented to demonstrate the feasibility of its use for the measurement of cleft palate casts. Measurement results are presented for several test surfaces and cleft palate casts. Accuracy in the X axis is +/- .79 mm., in the Y axis it is +/- 1.3 mm and in the Z axis +/- .46 mm.

Calibration↗
PubMed1982

Results by fluorescent immunoassay for phenytoin compared with those by enzyme immunoassay, liquid chromatography, and discrete analysis (Dupont aca).

We describe the Ames Fluorescent Enzyme Immunoassay procedure for the detection of phenytoin in serum, and compare the results with it with those by enzyme immunoassay(EMIT), "high-pressure" liquid chromatography, and the Dupont aca. Sera from 48 patients who were receiving phenytoin were promptly analyzed in duplicate by EMIT, frozen, then assayed within four weeks by the other three methods. Correlation was good between results by the fluorescent immunoassay and the other methods. The fluorescent immunoassay procedure is sensitive and requires a small sample volume (100 microliters). Sample reading time can be shortened from 30 to 15 s as the technician becomes more proficient, with no sacrifice of accuracy. The procedure is fast, easy to perform, specific, sensitive, and inexpensive; involves no radioactivity; and requires no temperature control. It is the current method of choice for detection of phenytoin in serum, in terms of precision and accuracy.

Chromatography, High Pressure Liquid↗
PubMed1979

Morphological findings in granular reticulum of arcuate nucleus neurons after clomiphene citrate administration.

The action of high doses of clomiphene citrate on the rough endoplasmic reticulum of the hypothalamic arcuate neurons of male cat has been studied. Clomiphene (250 mg/kg) produces an accumulation of typical paracrystalline material in the rough endoplasmic reticulum. After the administration of a protein-synthesis inhibitor no such material was observed in clomiphene-treated cats. The possibility exists that the specific ultrastructural changes seen indicate an increased protein synthesis in hypothalamic arcuate neurons.

Animals↗
PubMed1978

[Plasma creatinine, and clearance and urinary excretion of creatinine in children].

The 24 hour clearance of endogenous creatinine was compared with that of inulin in 112 children aged between 15 months and 17 years. The children had a variety of kidney disorders with renal function than ranged from normal to terminal renal failure. When the inulin clearance was less than 10 ml/min/1.73 m2 it was on average 75% of the value of the creatinine clearance. Between 10 and 60 ml/min/1.73 m2 the relationship of the inulin clearance to that of creatinine was similar (77%) but above 60 ml/min/1.73 m2 the ratio of the inulin clearance to that of creatinine was 1.05 with a wide scatter. With increasing degrees of renal failure the plasma creatinine increased less in the children under 2 years old than in those over this age so it is poor index of glomerular function in infants. In renal failure the urinary excretion of creatinine in 24 hours was reduced. When the clearance was less than 10 ml/min/1.73 m2, the urinary creatinine excretion for children under the age of 2 was 58% of the normal for the age and for children over 2, it was 86% of the expected mean.

Adolescent↗
PubMed1976

The role of metoclopramide in peroral jejunal biopsy: a controlled randomized trial.

Metoclopramide is known to enhance gastric emptying and stimulate duodenal and small-intestinal peristaltic activity. The effect of the drug on peroral jejunal biopsy was examined in a controlled, double-blind, randomized trial. Forty-nine patients (24 females and 25 males) who required jejunal biopsy for diagnostic purposes were admitted to the study. All the biopsies were performed by the same operator using the Quinton multipurpose suction biopsy tube and applying the same technique. Twenty-four patients ranging in age from 18 to 67 years (mean 44.5) received placebo intravenously (sodium metabisulfite), and 25 patients from 16 to 73 years old (mean 39.9) received 10 mg of metoclopramide intravenously prior to the jejunal intubation. Objective parameters of the study were (1) time in minutes required for the intubation at the biopsy site, ie, the area at the ligament of Treitz, and (2) fluoroscopy time. Intubation time in the placebo group was 22.3 +/- 1.9 min (mean +/- SEM) vs 11.3 +/- 1.4 min in the metoclopramide group (P less than 0.001). Fluoroscopy exposure time was 2.47 +/- 0.25 in the placebo group vs 1.40 +/- 0.12 min in the metoclopramide group (P less than 0.001). Subjective clinical evaluation of the operator's assessment of the procedure was based on a 0-4 scale (much easier = 0, easier = 1, average = 2, harder = 3, and much harder = 4). Metoclopramide administration resulted in a significantly easier performance of the procedure (P less than 0.001) but did not influence patient tolerance. Three patients who received metoclopramide and one receiving placebo developed mild to moderate drowsiness of short duration. The results of this controlled trial indicate that metoclopramide significantly shortens the time required for jejunal biopsy and reduces fluoroscopy exposure. Its regulatory action on gastrointestinal motility contributes to the easier performance of a valuable diagnostic procedure.

Adolescent↗
PubMed1975

Ultrastructural evidence of a secretory process in the rat pineal gland.

Pericapillar spaces of the rat pineal gland belong to the most active sites of this organ. Neighborhood of sympathetic nerve endings, capillaries and pinealocyte processes facilitates possibly the synthesis and the secretion of methoxyindoles. Lipid droplets migrate through the pinealocyte cellular processes towards the terminal enlargement or poles, where they are secreted into the pericapillar space, and the possibility that indoleamines are included in the lipid droplets has been discussed.

Animals↗
PubMed1975

B-scan ultrasound evaluation of the pancreas. Advantages and accuracy compared to other diagnostic techniques.

Over 200 patients were examined by B-scan ultrasound for suspected pancreatic disease; in 94 cases a final diagnosis was proved. The diagnostic accuracy of ultrasound, upper gastrointestinal examination, isotope pancreatography, and arteriography is compared. The diagnostic ultrasound features of the various pancreatic disease processes are described. Pancreatic sonography provides the most accurate and least expensive method for evaluating the pancreas with no known patient morbidity. The upper gastrointestinal series and radionuclide study are complementary to sonography. Ultrasound should be the initial examination for the evaluation of patients with suspected pancreatic disease or epigastric mass.

Angiography↗
PubMed1975

Vasodilator system for the face.

The authors describe investigations in cats to delineate a vasodilator system to the face, which they undertook after a previous study showed that radiofrequency coagulation of the trigeminal ganglion produced a pronounced flush in the skin of the corresponding division. Results demonstrate a vasodilator system emerging from the brain stem with the facial nerve which, by way of the greater superficial petrosal nerve, reaches the trigeminal ganglion. There the fibers are distributed to each of the divisions of the fifth nerve; in addition, a moderate number of vasodilator fibers also appear to leave the brain stem directly with the trigeminal nerve. Vasodilator fibers also appear to leave the brain stem directly with the trigeminal nerve. Vasodilator effects were elicited by stereotaxic stimulation of the facial and trigeminal nuclei in the brain stem. There is, therefore, a dual vasomotor control of the facial cutaneous vascular bed; the classical sympathetic vasoconstrictor system of the face is complemented by a vasodilator system capable of producing changes of equal but opposite amplitude in vessel caliber.

Animals↗