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Biomedical subjects

H González

Publications and source records attributed to H González.

At least 19 recordsLinked to original sources
PubMed1992

Bulbospinal inhibition of PAD elicited by stimulation of afferent and motor axons in the isolated frog spinal cord and brainstem.

1. In the isolated spinal cord and brainstem of the frog, stimulation of the brainstem (BS) with trains of 3-4 pulses at 60-400 Hz produced dorsal root potentials (DRPs). The lowest threshold sites eliciting DRPs were located at the level of the obex up to about 2.5 mm rostrally, 0.5-1.2 mm laterally, between 0.5 and 1.6 mm depth. This region corresponds to the bulbar reticular formation (RF). 2. Stimulation of the RF with strengths below those required to produce DRPs, very effectively inhibited the DRPs produced by stimulation of a neighboring dorsal root (DR-DRPs) as well as the DRPs produced by antidromic stimulation of the central end of motor nerves (VR-DRPs). The inhibition was detectable 20 ms after the first pulse of the conditioning train, attained maximal values between 50 and 100 ms and lasted more than 250 ms. 3. Stimulation of the bulbar RF increased the negative response (N1 response) produced in the motor pool by antidromic activation of motoneurons. The time course of the facilitation of the N1 response resembled that of the reticularly-induced inhibition of the VR-DRPs and DR-DRPs. 4. The present series of observations supports the existence of reticulo-spinal pathways that are able to inhibit the depolarization elicited in afferent fibers by stimulation of other afferent fibers or by antidromic activation of motor axons. This inhibition appears to be exerted on the PAD mediating interneurons and is envisaged as playing an important role in motor control.

Afferent Pathways↗
PubMed1992

Induction of beta-lactamase from Shigella flexneri UCSF-129: purification by affinity chromatography and some properties.

Lincomycin, an inhibitor of protein synthesis, was an excellent inductor of beta-lactamase, and its total activity and specific activity were increased 2.5- and 3.6-fold respectively. The beta-lactamase produced by Shigella flexneri UCSF-129 was purified by affinity chromatography on phenylboronic acid-agarose with a type B column using an hydrophobic spacer arm (6-aminohexanoic acid activated with succinimide). The yield and specific activity were 96% and 29,283 U/mg, respectively. These were 1.7- and 3.8-fold higher, respectively, than those obtained by the traditional method using ion-exchange chromatography and gel filtration. The working-time was reduced to a third, and the enzyme preparation was shown to be pure by several criteria. From nine divalent cations assayed, only Sn(II) inhibited the enzyme by 74%, and the chloride ion did not have any effect on enzyme activity.

Anti-Bacterial Agents↗
PubMed1991

[Fast intravenous rehydration with 90 mmol/L of sodium in dehydrated children with diarrhea].

Twenty-two infants with moderate dehydration due to diarrhea in whom oral rehydration therapy (ORT) was contraindicated or who failed to respond to this method of therapy were treated with rapid intravenous rehydration (RIR). Clinical signs of dehydration without shock allowed us to estimate 5% to 10% of weight loss. Patients were 11 days to 19 months old, and 9 of them were undernourished. A standard solution containing 90 mmol/L sodium, 80 mmol/L chloride, 30 mmol/L bicarbonate, 20 mmol/L potassium and 111 mmol/L glucose was used for all patients. The IV infusion was maintained until the rehydration was completed at a rate of 15 to 20 mL/kg/hour. Complete rehydration was successfully achieved in all patients. A total of 89.5 +/- 25.0 mL/kg (mean +/- SD) was needed and the duration of the IV infusion was 5.1 +/- 1.6 hours. Weight gain achieved was 6.5 +/- 1.6%. None of the patients developed hypernatremia following treatment. The initial base deficit, -9.5 +/- 6.6, was reduced to -3.5 +/- 2.9. All of the patients tolerated refeeding immediately after completion of the IV infusion. Our study suggests that this modality of rehydration is well tolerated, safe and effective and enhances the possibility of an early hospital discharge.

Dehydration↗
PubMed1990

Fibronectin in meningococcal sepsis. Correlation with antithrombin III and protein C.

Plasma fibronectin was measured with Laurell's immunoelectroassay in 44 patients with meningococcal sepsis. The average value (15.0 +/- 7.9 mg/dl) was lower than that in normal children (27.4 +/- 8.7 mg/dl) (p less than 0.001). Fibronectin in patients correlated positively with antithrombin III (AT-III) values (p less than 0.02), but not with protein C (0.05 less than p less than 0.1). The decrease of fibronectin had no prognostic value. The fibronectin levels were lower in patients with disseminated intravascular coagulation (DIC+), than in those without DIC (DIC-) (p less than 0.02), but were lower in both groups than in a normal control group. A negative correlation between fibronectin and protein C was only present in DIC- patients (r: -0.773 = p less than 0.01). Fibronectin varied independent of AT-III and protein C in DIC+ patients. The study was repeated in 11 patients 24 hours after admission when fibronectin had decreased in 7/11 cases (mean decrease: -2.7 +/- 8.7 mg/dl). This variation correlated in a negative way with AT-III (r: -0.659 = p less than 0.05). In meningococcal sepsis fibronectin decreases very early, even in DIC- patients and its relationship to AT-III and protein C is different, depending on the presence of DIC and on the stage of evolution of the disease.

Antithrombin III↗
PubMed1990

[AIDS and pregnancy: a case of mother-child transmission].

We report the case of a 4 month old baby in an advanced stage of HIV infection with AIDS according to the CDC definition. The HIV-infected mother was sexually promiscuous and a drug addict. The timing and route of the infection are speculative. The child was born by cesarean delivery, did not receive blood or blood products and was not breast-fed. It is postulated that the most probable route of HIV infection in this child was intrauterine vertical transmission.

Acquired Immunodeficiency Syndrome↗
PubMed1990

[Maturation of proteins C and S in childhood].

The antigenic concentrations of protein C, total protein S (TPS), free protein S (FPS) percentage of protein S that corresponds to the free form (PFPS), C4BP and factor II throughout childhood (values in cord blood, at 48 hours, at 15 days, 1-6 months, 6 months-2 years, 2-7 years and 7-14 years) have been studied. The maturation of these factors is variable, reaching average values similar to those of adults at between 1 to 6 months for protein C and TPS; at 15 days for factor II; and at between 6 months and 2 years for C4BP, whose development occurs latest. Vitamin K increases the values of protein C, factor II and FPS at 48 hours after birth, but does not modify the figures for TPS or C4BP. The thrombotic index is below 0.6 for protein C at 15 days, but at this age the figure for protein S is above 1.0.

Adolescent↗
PubMed1990

Inactivation of beta-lactamase from Shigella flexneri UCSF-129 by 6-beta-iodopenicillanic acid: classification of the enzyme.

The beta-lactamase from Shigella flexneri UCSF-129 was irreversible inactivated by 6-beta-iodopenicillanic acid. Only one serine residue was modified, according to the spectra change and the amino acid analyses. A pH variation of 0.3 units was found when the chemically modified enzyme was submitted to isoelectric focusing. The inactivation constant of the fast time course reaction was 0.1 seg-1. Protection of 96% was obtained, using cephradine 2,830 times more concentrated than 6-beta-iodopenicillanic acid. It is suggested that this enzyme belongs to class A, according to Ambler (1980).

Hydrogen-Ion Concentration↗
PubMed1988

[Cystic angiomatosis of bone with hematologic involvement. Report of a case].

A case of cystic angiomatosis of bone without visceral involvement is presented. Lesions were noted in: skull, ribs, pelvis, long bones and phalanges. Besides clinical and radiological findings, the case, associates pancytopenia and coagulation disorders. The possibility of a bone marrow failure due to invasion of marrow by cystic angiomas and localized intravascular coagulation are discussed as cause of hematologic alterations.

Angiomatosis↗
PubMedDate not supplied

[Diagnostic accuracy of fine needle aspiration cytology guided by ultrasonography in intra-abdominal and retroperitoneal lesions].

UNLABELLED: Evaluation of the fine needle aspiration cytology guided by ultrasonography in the diagnosis of abdominal and retroperitoneal tumors. DESIGN: Transversal study of diagnostic standard-criterion test. PLACE: Ultrasonographic Unity Digestive Disease Department. Hospital Oncológico Padre Machado. SAMPLE: 98 patients with intraabdominal and retroperitoneal lesions. INTERVENTION: Fine needle aspiration cytology guided by Ultrasonography. INDICE TEST: Laparoscopy and/or laparotomy. MEASUREMENTS: Estimation of sensibility (S), Specificity (E), Efficacy (Ef), positive predictive value (VPP), negative predictive value (VPN), measure of false positives (TFP) and measure of false negatives (TFN) by diagnosis method. RESULTS: VP: 81%; VN: 12%; FP: 1%; FN: 6%; S: 93%; E: 92.3%; Ef.: 97%; VPP: 98.7%; VPN: 66%; TFP: 1.25%; Benign lesions: 22.5%; Malignancy lesions: 65.5%; non lesions: 12%; complications: severe: 1%, non significance: 5%. CONCLUSIONS: Fine needle aspiration cytology guided by ultrasound has high sensibility, specificity, efficacy, with low value of false positive. However, it has high incidence of false negatives and negative predictive value. We recommend diagnostic procedures when the suspicion of tumor is high did the cytology is negative.

Abdominal Injuries↗
PubMedDate not supplied

[Indomethacin in the treatment of acute cholecystitis and biliary colic].

Prostaglandins GE2 produces on the gallbladder a rise in intraluminal pressure, an increase in in intraluminal secretion, improves gallbladder contraction and decreases its absorption capacity. In this study, patients who received indomethacin twice a day by rectum, showed a significant reduction in volume and area of gallbladder after 24 and 48 hours (P < 0.05). The gallbladder volume after 24 hours had SEM 9.13 cm3, 95% CI 55.28 + 73.49 (P < 0.05). Score pain reduction after 24 hours was also significant (P < 0.001). The patients who underwent the classical Baralcina treatment of one IV vial BID showed a reduction in diameter and area of gallbladder but this was not statistically significant (P < 0.10). Reduction of volume at 24 hours was SEM 5.34 cm3 95% CI - 64.72 + 76.60 P 0.10 NS; and at 48 hours SEM 3.5 cm3, 95% CI 59.52% + 66.52 P 0.40. Score pain reduction was only significant at 48 hours P 0.001. The number of patients without pain at 24 hours was significantly higher in the indomethacin group ESP 0.21; 95% CI 0.46 + 0.88 P 0.001. In conclusion indomethacin is a useful medication in the treatment of acute cholecystitis and biliary colic due to its anti-prostaglandin effect on the gallbladder.

Acute Disease↗
PubMedDate not supplied

[Effect of labor on the acid-base equilibrium of the newborn infant].

The values of pH, PCO2, PO2 and base excess were measured at the time of birth, from the umbilical artery, in a group of 19 normal newborn infants from vaginal deliveries and compared to 19 infants born by elective cesarean sections without labor. The value of pH was significantly lower (7.23 +/- 0.06) in vaginal deliveries compared to elective cesarean sections (7.27 +/- 0.03) p less than 0.01. The best correlations occurred between pH and PCO2 (r: 0.72 p less than 0.01) in vaginal deliveries and pH and base excess (0.73 p less than 0.01) in cesarean sections. Normal values for umbilical arterial pH should consider the influence of labor in the acid base balance of the newborn infant. We consider that pH value under 7.11 (mean -2 SD) in vaginal deliveries and under 7.21 in elective cesarean sections are indicative of neonatal acidosis.

Acid-Base Equilibrium↗
PubMedDate not supplied

[Colorectal cancer: anatomopathological findings in 100 cases treated with surgery].

One hundred cases of colorectal cancer resected at the University Hospital of Caracas are presented, with emphasis in the Pathological Findings (Anatomical location and staging included). Age and sex distribution are comparable to data presented in other local series; in contrast, the proportion of rectal cancer is below expectations (only 5% of all cancer of the large intestine). The majority of cases are diagnosed in advanced stages (predominantly Dukes stages B and C).

Adenocarcinoma↗