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Biomedical subjects

M Gonzalez

Publications and source records attributed to M Gonzalez.

At least 253 records · Page 14Linked to original sources
PubMed1984

Copper distribution in the normal human brain.

Copper concentration was determined in samples from 38 areas of 7 normal human brains. The grey matter contained higher concentrations of copper than the white matter. Identical areas of the grey and white matter of the cerebral cortex showed significant differences between individuals. In the caudate nucleus the highest concentrations of copper were found in the tail followed by the body and the head, respectively. A negative linear regression between age and brain copper levels was demonstrated.

Adolescent↗
PubMed1984

Intracranial complications of frontal sinusitis. A report of two cases.

Two cases are reported of intracranial complications of sinusitis, unusual nowadays. They were caused by osteomyelitis of the frontal bone following chronic frontal sinusitis. These cases were distinguished by complete destruction of the posterior wall of the sinus involved: in one of the cases there was an acute central neurological disturbance caused by a cerebral abscess; in the other patient, who came for consultation because of a Pott's Puffy tumour, a sizeable epidural abscess was found.

Adult↗
PubMed1984

Phenotypic characterization of skin-infiltrating cells in pagetoid reticulosis by monoclonal antibodies.

The immunological characterization of the infiltrating cells in a patient with a disseminated form of Pagetoid reticulosis (PR) was carried out-in histological section and cell suspensions--by means of a panel of monoclonal antibodies and classical markers (E-rosette and surface immunoglobulins (SIg]. Most of the infiltrating cells were seen to be mature T-lymphocytes with a suppressor/cytotoxic phenotype (T11+, T3+, T8+, T4-). The results suggest that this variant of PR represents a special histological type of cutaneous T cell lymphoma.

Aged↗
PubMed1983

Rotational behavior in the cat induced by electrical stimulation of the pulvinar-lateralis posterior nucleus complex: role of the cholinergic system.

We studied the involvement of the cholinergic system in the contralateral head-eye-body turning induced in the cat through stimulation of the pulvinar-lateralis posterior nucleus complex (P-LP). In 17 cats through a cannula aimed at the P-LP, agonists and antagonists of the cholinergic system were injected. The electrical activity of the P-LP could be recorded through the same cannula or through electrodes attached to it. In addition, electrodes were implanted ipsilaterally in the dorsal hippocampus, caudate nucleus, amygdala, and superior colliculus to record through them and through one screw placed on the skull the electrical activity of those structures and of the cortical P-LP projection. Seven days after surgery, carbachol, an agonist of the cholinergic system was injected in the P-LP, and the behavior and electrical activity of the unrestrained cat (previously accustomed to a plastic cage) were recorded. A control volume of 0.9% NaCl was always injected previously. The usual drug volume injected was 1 microliter; occasionally, 2 microliter were injected. Weekly or biweekly sessions were conducted to determine (a) the threshold for cholinergic activation, (b) the threshold for turning behavior, (c) the blocking effect of local atropine sulfate injected previously, (d) the effect of haloperidol previously injected (locally or systemically), and (e) the effect of dioxolane, an exclusive muscarinic agonist. In 14 of 17 cats, contralateral turning behavior was evoked by carbachol. In two of the three cats that did not respond to carbachol, dioxolane induced turning. The effect of dioxolane was similar to that of carbachol when tried in five cats. Besides turning behavior, carbachol produced numerous symptoms due to cholinergic activation. Atropine blocked the rotational effect of carbachol in all cats, and haloperidol blocked it in 68% of them. Electrolytic coagulation of the dorsal hippocampus surrounding the P-LP did not disturb the effects induced by carbachol. These experiments show that both systems of the P-LP, cholinergic and catecholaminergic, are involved in the contralateral turning. We conclude that the effect induced by carbachol is due to activation of muscarinic receptors because it is totally blocked by local atropine sulfate and is reproduced by dioxolane, an exclusive muscarinic agonist.

Acetylcholine↗
PubMed1982

Percutaneous intraaortic balloon pumping: initial experience.

The necessity of surgical procedures for insertion as well as for removal of the balloon catheter remains a serious disadvantage of IABP. The percutaneous technique of insertion and removal of a specially designed balloon catheter is therefore of a great interest. Our initial clinical experience shows that this is simple, rapid and safe and can be performed at the bedside in a few minutes by any physician experienced with arterial catheterization. Its hemodynamic efficiency is identical. No specific complications were encountered although two cases of pulmonary embolism were recorded. A causal relationship between pulmonary embolism and the percutaneous removal of a balloon catheter must therefore be considered.

Aged↗
PubMed1982

Regulation of bile salt transport in rat liver. Evidence that increased maximum bile salt secretory capacity is due to increased cholic acid receptors.

Expansion of the bile salt pool size in rats increases maximum excretory capacity for taurocholate. We examined whether increased bile salt transport is due to recruitment of centrolobular transport units or rather to adaptive changes in the hepatocyte. Daily sodium cholate (100 mg/100 g body wt) was administered orally to rats. This treatment was well tolerated for at least 4 d and produced an 8.2-fold expansion of the bile salt pool. This expanded pool consisted predominently (99%) of cholic and deoxycholic acids. Significantly increased bile salt transport was not observed until 16 h after bile acid loading, and maximum elevations of transport capacity to 2.3-fold of control required approximately 2 d. In contrast, maximum sulfobromophthalein excretion rates increased 2.2-fold as early as 4 h and actually fell to 1.5-fold increase at 4 d. We studied the possibility that this adaptive increase in bile salt secretory transport was due to changes in canalicular surface membrane area, lipid composition, or increased number of putative carriers. Canalicular membrane protein recovery and the specific activities of leucine aminopeptidase, Mg(++)-ATPase and 5'-nucleotidase activities were unaltered by bile salt pool expansion. The content of free and esterified cholesterol and total phospholipids was unchanged in liver surface membrane fractions compared with control values. In contrast, sodium cholate administration selectively increased specific [(14)C]cholic acid binding sites twofold in liver surface membrane fractions. Increased numbers of [(14)C]cholic acid receptors (a) was associated with the time-dependent increase in bile salt transport, and (b) was selective for the taurine conjugate of cholate and (c) was reduced by chenodeoxycholate. Changes in bile acid binding sites 16 h following taurocholate and chenodeoxycholate and the lack of change with glycocholate was associated with comparable changes in bile salt transport. In conclusion, selective bile salts increase bile salt transport in the liver through an adaptive increase in the density of putative bile acid carriers in liver surface membrane.

Animals↗
PubMed1981

Disseminated Trichosporon beigelii (cutaneum).

Two cases of invasive Trichosporon beigelii (syn. cutaneum) infection are reported and are compared with the eight other previous reports. All affected patients were either immunosuppressed or had recently undergone a surgical procedure. The diagnosis had been delayed and the prognosis was poor. Only two patients recovered after vigorous antimycotic therapy and concomitant remission of their leukemia. A biopsy of the skin lesion, as illustrated in one of our patients, may prove to be useful in the early diagnosis.

Aged↗
PubMed1981

The development of lysosomal apparatus. II. Incorporation, subcellular distribution, and intraparticulate hydrolysis of 131 I-albumin by liver of mice at perinatal stages.

Mouse fetuses at 15th and 18th day of gestation, and newborns aging 0, 5, 10, and 15 days were injected i.p. with 131 I-albumin (RISA). The degree of incorporation by liver and the intraparticulate hydrolysis of RISA in 27,000g x 10 min. particles increased after birth. By this time, changes in subcellular distribution of RISA and marker enzymes were also observed. Following an i.p. injection of India ink, numerous hepatic cells stained with carbon particles were observed at the light microscope from day 5 of life. The results suggest that the lysosomal apparatus acquires full capacity to incorporate colloidal particles and to degrade foreign macromolecules in the first week of life.

Acid Phosphatase↗
PubMed1981

Myocyte growth without physiological impairment in gradually induced rat cardiac hypertrophy.

A surgical technique was developed to place sutures around the pulmonary arteries of young rats (about 1 month old and 100 g body weight). As the operated rats grew, the pulmonary arteries were gradually constricted, leading after 4-6 weeks to the development of severe right ventricular hypertrophy with free wall weights about twice those from control rats. There were no signs of heart failure or cardiac decompensation. Collagen concentrations were the same in operated and control rats. Myocytes were isolated from right ventricles by enzymatic digestion. Autoradiographic studies showed considerable uptake in non-myocyte nuclei. Myocyte sarcomere lengths were unchanged. However, myocyte lengths and areas increased sufficiently to account for the increase in free wall weights observed. Physiological studies were done on isolated papillary muscles and ventricular strands, which were subsequently fixed. The force-generating capability at optimum length, magnitude of active compliance, and maximum speed of shortening (using four different techniques) were measured in each isolated muscle. There were no significant changes observed between operated and control rats. Microscopic examination of the muscle cross-sections confirmed that average myocyte area in the muscles obtained from operated rats was significantly increased. The results show that it is possible to obtain considerable increases in average myocyte size (by about a factor of 2) while still maintaining normal physiological function.

Animals↗
PubMed1980

Intravenous aminophylline therapy for asthma. A comparison of two methods of administration in children.

Eleven asthmatic children were given intravenous aminophylline by two methods of administration: a 6 mg/kg loading dose followed by a 1.4 mg/kg/hr continuous infusion, or a bolus of 4 mg/kg given every four hours. Expiratory flow rates (forced expiratory volume at 1 s and expiratory flow at 50% of vital capacity) were recorded at intervals for 24 hours with each regimen. Although the intermittent administration of aminophylline produced a substantial improvement, there was a significantly greater pulmonary response to continuous infusion.

Adolescent↗
PubMed1980

Reversal of ethinyl estradiol-induced bile secretory failure with Triton WR-1339.

The effects of Triton WR-1339 and phenobarbital on ethinyl estradiol bile secretory failure were examined to determine the mechanism responsible for decreased bile salt excretion. When administered to ethinyl estradiol-treated rats, Triton WR-1339 restored bile salt independent bile flow and maximum taurocholate transport, whereas phenobarbital corrected bile flow only. Ethinyl estradiol decreased the activities of Na(+)-K(+)-ATPase, 5'-nucleotidase, while increasing the activities of Mg(++)-ATPase and alkaline phosphatase. In contrast to these heterogeneous changes in surface membrane enzyme activities, the number and affinity of [(14)C]cholic acid carriers were not altered. When administered in vivo or added directly to surface membrane fractions Triton WR-1339 restored the activities of Na(+)-K(+)-ATPase and Mg(++)-ATPase of rats treated with ethinyl estradiol through a process that did not require protein synthesis (unaffected by cycloheximide). Phenobarbital also restored the activity of Na(+)-K(+)-ATPase to control levels, but, unlike Triton WR-1339 it did not correct the defect responsible for reduced bile salt secretion. Ethinyl estradiol increased the concentration of cholesterol esters in surface membrane fractions. When administered to ethinyl estradiol-treated rats, Triton WR-1339 restored cholesterol ester concentrations to normal, whereas phenobarbital did not. These combined data suggest that decreased or altered bile salt carriers or reduced sodium driving forces resulting from impaired activity of Na(+)-K(+)-ATPase are not responsible for decreased bile salt excretion in ethinyl estradiol-treated rats. It is proposed that the diverse changes in surface membrane function, which are associated with ethinyl estradiol bile secretory failure, may be the result of a generalized alteration in membrane lipid structure.

Animals↗