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Biomedical subjects

M García

Publications and source records attributed to M García.

At least 253 records · Page 14Linked to original sources
PubMed1993

Decrease in calcitonin-containing cells in truncus arteriosus.

Experimental studies in chick embryos have demonstrated that truncus arteriosus (TA), a form of conotruncal cardiac defect, is due to abnormalities in the cranial neural crest. However, no data are available to support this hypothesis in humans with isolated TA. In the present study, the assessment of calcitonin immunoreactive cells (C-cells) has been employed to evaluate whether or not the proportion of thyroid cells derived from the cranial neural crest is normal in patients with isolated TA. Thyroid sections from 15 such patients in which no other extracardiac malformations were neither clinically nor pathologically found, and from 11 control age-matched patients were studied immunohistochemically at autopsy in order to determine the number and distribution of calcitonin-containing cells. The volume density of C-cells (0.888%) and the number of C-cells per follicle (0.991) was significantly lower in patients with TA than in control patients (3.475%, and 2.367, respectively). The decrease of neural crest-derived cells in the thyroid of patients with "isolated" TA documents more extent abnormalities than clinically suspected and supports the hypothesis of neural crest disturbance as the pathogenetic factor responsible for this heart malformation.

Calcitonin↗
PubMed1993

Afferent projections to the reticular thalamic nucleus from the globus pallidus and the substantia nigra in the rat.

This study was designed to explore the thalamic output of the globus pallidus (GP) and the pars reticulata (SNR) of the substantia nigra (SN) upon the reticular thalamic nucleus (Rt) in the rat. Thus, 13 animals were deeply anesthetized and stereotaxically injected with horseradish peroxidase (HRP) conjugated with wheat germ agglutinin (HRP-WGA) mixed with HRP free in different portions of GP and SN. Next, we evaluated the anterograde terminal labeling in the rostral two-thirds of Rt. Confirmatory results were obtained in our case material about the entity of GP reticular projections, and some new data are presented here regarding the projections from GP and SNR upon Rt. Among them we emphasize the following for the rostral two-thirds of this thalamic nucleus: a) the projections from GP are more abundant than those arising from SNR; b) a dorsoventral topographical design appears to be clear in the organization of the afferent connections from GP to Rt; c) SNR projects more abundantly to the ventral sectors of Rt; and d) the central core of Rt is more innervated by GP than by SNR, which innervates Rt mainly in its peripheral portions. These results raise the possibility of multiple and differentiated assignments of the output nuclei of the basal ganglia upon the thalamus and its connectivity.

Afferent Pathways↗
PubMed1993

[Detection of Pneumocystis carinii in clinical samples by the polymerase chain reaction. Comparison with the methenamine silver technique].

BACKGROUND: A comparison of polymerase chain reaction (PCR) with methenamine silver stain was performed on clinical specimens for diagnosis of Pneumocystis carinii pneumonia in immunosuppressed patients. METHODS: 25 clinical samples (10 induced sputa, 12 transthoracic needle aspirations and 2 bronchoalveolar lavages) from 17 patients with AIDS and respiratory symptoms were studied. We performed DNA amplification by using 2 primers that amplify the mitochondrial large rDNA sequence of P. carinii. RESULTS: The sensitivity and specificity of the PCR technique were 92.8% and 100% respectively, with a positive predictive value of 100% and negative predictive value of 92.3%. The sensitivity of the silver stain were 65%, specificity 100%, positive predictive value 100% and negative predictive value 63%. CONCLUSION: The PCR technique is more sensitive than the methenamine silver stain for detecting Pneumocystis carinii in respiratory specimens from patients with pneumonia. Consequently it could be a very good alternative to classical methods in diagnosis of P. carinii infections.

AIDS-Related Opportunistic Infections↗
PubMed1993

Immunoglobulins in stimulated tears of dogs.

Immunoelectrophoresis and single radial immunodiffusion were used to identify and measure tear immunoglobulin concentrations in 50 healthy dogs. Immunoglobulin A and IgG were detected in all samples analyzed, whereas IgM was not detected in any sample. Mean IgA concentration was 25.28 +/- 1.9 mg/dl, adult dogs (> 18 months) having significantly higher mean value. The IgA concentration related to age had significant (P < 0.006) positive correlation; mean IgG concentration was 23.10 +/- 1.72 mg/dl. Linear correlation analysis revealed significant (P < 0.0007) correlation coefficient between tear total protein and IgA concentrations. The IgA and IgG concentrations also were significantly (P < 0.0001) correlated when expressed as milligrams per 100 mg of protein. Relation with sex was not established for either immunoglobulin.

Aging↗
PubMed1993

[Acute toxoplasmosis. Laboratory diagnosis].

BACKGROUND: The microbiological diagnosis of acute toxoplasmosis in immunosuppressed patients, cannot, usually, be done through serological techniques. The methods for isolation or direct detection of parasite are the only ones that might be helpful to determine an earlier diagnosis, on these patients. METHODS AND RESULTS: The use of urine in 3 patients with acute toxoplasmosis, allowed us to isolate the parasite after inoculation of the sample in human embryonic fibroblast cell line (MRC-5). CONCLUSION: In our opinion urine could be an adequate sample for isolation or detection of Toxoplasma gondii in immunosuppressed patients, and an alternative to serological methods, as well.

AIDS-Related Opportunistic Infections↗
PubMed1992

Phospholipids of Trypanosoma cruzi: increase of polyphosphoinositides and phosphatidic acid after cholinergic stimulation.

We have studied the effect of carbamoylcholine in Trypanosoma cruzi epimastigote forms prelabelled with [32P]-Pi. Suspensions of cells were incubated at 28 degrees C to measure changes in the levels of [32P]-labelled phospholipids after stimulation. The presence of this cholinergic agonist induced changes in the phosphoinositide metabolism; a shift in the levels of phosphatidylinositol 4,5-bisphosphate (PIP2), phosphatidylinositol 4-phosphate (PIP) and phosphatidic acid (PA) was observed, whereas the levels of the other glycerophospholipids were not changed. This study shows that carbamoylcholine either directly or indirectly influences changes in phosphoinositide metabolism.

Animals↗
PubMed1992

Kinetics of a model of autocatalysis, coupling of a reaction in which the enzyme acts on one of its substrates.

A global kinetic analysis is presented of a model of an enzyme autocatalytic process, to which a reaction is coupled, in which the enzyme acts upon one of its substrates. The kinetic equations of both the transient phase and the steady state are derived for this mechanism. In addition, we determine the corresponding kinetic equations for several particular cases which are characterized by certain relations between the rate constants. Finally, a kinetic data analysis is proposed for one of these particular cases. It can easily be extended to any of the other cases.

Catalysis↗
PubMed1992

Solanum chrysotrichum (Schldl.) a plant used in Mexico for the treatment of skin mycosis.

An ethnobotanical field study carried out in 200 rural communities determined that the leaves of Solanum chrysotrichum Schldl. are used in Mexican traditional medicine for the treatment of skin mycosis, being particularly recommended to cure Tinae pedis. Clinical trials were performed using a cream containing 5% of a methanolic leaf extract of this plant. Results showed that 45% of the patients were completely cured after 4 weeks of topical treatment. The rest of the cases improved notably in comparison with the control group of patients using the habitual miconazole treatment. The same plant extract inhibited the growth in vitro of the dermatophytes Trychophyton mentagrophytes, T. rubrum and Microsporum gypseum at MICs under 15 mg/ml.

Antifungal Agents↗
PubMed1992

Increase in rat pup ultrasonic isolation calls induced by lindane.

The neurotoxic agent lindane was tested for its ability to alter the rate of ultrasonic isolation calls of suckling rats. Doses that did not produce any sign of convulsant activity significantly increased the number of calls and the cumulative time of calling in male pups. At days 10-13 of age after a single dose of 20 mg/kg lindane, animals showed more than twice the control call values. After daily dosing with 10 mg/kg during the first week of age call increases also appeared. It is suggested that lindane has an anxiogenic effect mediated through its action on the benzodiazepine-GABAA receptor-chloride channel complex.

Animals↗
PubMed1992

[Long-term results of endoscopic sphincterotomy in the treatment of residual/recurrent choledocholithiasis].

Endoscopic sphincterotomy is widely accepted as the technique of choice in the treatment of residual or recidivant choledocholithiasis since the results obtained with this technique are favorable when compared to biliary surgery in most series. However, the experience of long term follow up of patients with choledocholithiasis in whom this technique would have been applied as the only treatment is still scarce up to date. We have studied 40 patients (mean age 65.6 +/- 11.1 years) with residual or recidivant choledocholithiasis who had undergone endoscopic treatment successfully before the 30th of June 1985, who could be contacted by a mailed questionnaire or by phone by August 1990. The follow up time 70.7 +/- 19.4 months (mean +/- typical deviation). Out of them, 36 (90%) had been asymptomatic up to the contact date (30 cases) or up to death due to causes not related to biliary pathology (6 patients). Out of the 4 remaining patients, 2 presented mild dyspepsia and another patient has probably developed recidivant choledocholithiasis (according to I.V. cholangiography). The fourth patient presented a severe episode of cholangitis and acute pancreatitis, related to a new episode of choledocholithiasis and died 5 and a half years after the endoscopic sphincterectomy. This represents a 2.5% mortality. These long term results of endoscopic sphincterotomy in patients with residual or recidivant choledocholithiasis are an other point in favour of using this technique as the single treatment of choice in patients above 60 years old.

Adult↗
PubMed1992

[Carney's triad: a short review apropos a case].

We communicate a case with the Carney triad (gastric leiomyosarcoma, pulmonary chondromatosis and extra-adrenal paraganglioma). It is, to our knowledge, the first case to be communicated in the Spanish scientific literature. We discuss some peculiar aspects of the debut and clinical evolution of this syndrome, together with its prognosis. We conclude that in clinical practice, the appearance in a young subject, specifically females, of multiple gastric myogenic tumors, should elicit the performance of further noninvasive procedures, needed to discard the diagnosis of the Carney triad.

Adult↗
PubMed1992

[Knowledge and prejudice about leprosy in Havana City].

One thousand two hundred sixteen people living in 6 representative municipalities in Havana City were surveyed in order to know what they knew about leprosy and how these patients are perceived by them. The purpose was to ascertain if the community was prepared to help them to their adaptation to a socially useful life, which is one of the tenets of the Program for the Control of this disease. It was proved that only 10% had the necessary knowledge about leprosy and the remaining 90% had wrong notions about it. It is concluded that the community is not prepared for bringing about a change in the present status of this condition.

Adolescent↗