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Biomedical subjects

J González

Publications and source records attributed to J González.

At least 19 recordsLinked to original sources
PubMed1995

Re-intubation increases the risk of nosocomial pneumonia in patients needing mechanical ventilation.

In order to confirm that re-intubation can be a risk factor of nosocomial pneumonia in mechanically ventilated patients, a case-control study was performed. Forty consecutive patients needing re-intubation were selected as cases. Each case was paired with a matched control for the previous duration of mechanical ventilation (+/- 2 d). Nineteen (47%) of the cases developed pneumonia after re-intubation compared with 4 (10%) of the controls (odds ratio [OR] = 8.5; 95% confidence interval [CI] 1.7 to 105.9; p = 0.0007). After adjusting for age, sex, and presence of prior bronchoscopy, the conditional logistic regression analysis demonstrated that re-intubation was the only significant factor related to the development of pneumonia (OR: 5.94; 95% CI 1.27 to 22.71; p = 0.023). Sixteen (73%) of the 22 patients lying semirecumbent during the interval between extubation and re-intubation developed nosocomial pneumonia versus three (16%) of the 18 in supine position (p = 0.001). These results indicate that semirecumbency during the period between extubation and re-intubation may play a role in nosocomial pneumonia development in patients who need re-intubation. Total intensive care unit stay (19.4 +/- 10 versus 13.9 +/- 11.9 days, p = 0.0008) and crude mortality (35 versus 20%, p = 0.14) were also higher in re-intubated patients when compared with controls. We conclude that re-intubation is a risk factor for ventilator-associated pneumonia and might be avoided in a substantial number of cases.

Case-Control Studies↗
PubMed1995

[Dyslipidemia and hyperinsulinemia in normoglycemic-obese relatives of patients with non-insulin dependent diabetes mellitus].

To determine the most frequent dyslipidemias among first-degree relatives of NIDDM patients, and its association with their glucose-tolerance status and hyperinsulinemia, we have started to examine members of NIDDM pedigrees, according to American Diabetes Association guidelines for nuclear family studies. In a large family with 2 NIDDM siblings in the 2nd generation, and 4 siblings with NIDDM in the 3rd generation, we have evaluated 14 first degree relatives and also 15 sex and aged matched healthy control subjects without family history of diabetes. The NIDDM relative group presented BMI = 31.8 +/- 3.9 kg/m2, SBP = 128 +/- 18.2 mmHg, DBP = 84 +/- 12.7 mmHg. Both relatives and controls were subjected to a 2h 75g OGTT for glucose and insulin determinations. Although none of NIDDM relatives has IGT, both Glycemic Area (GA) and Insulin Area (IA) were greater (p < 0.01) in the NIDDM relative group. The Insulin/Glucose ratio was also higher (p < 0.01) at 0 and 120 min of OGTT, this might be indirect evidence of Insulin- Resistance. Fasting serum lipids in the NIDDM relatives were TG = 148 +/- 24mg/dl, T-Chol = 244 +/- 10.7mg/dl, HDL-C = 34.2 +/- 2.5mg/dl; lipids in the control group were TG = 84.8 +/- 10.1mg/dl, T-Chol = 167 +/- 10.2mg/dl, HDL-C = 44.4 +/- 2.6mg/dl. Electrophoretic pattern showed type IIa (30.7%) and IIb (61.5%) hyperlipidemias in the NIDDM relatives. In this group, there was a positive and significant association between basal insulin and DBP (r = 0.67; p < 0.01), and between DBP and both TG (r = 0.74; p < 0.01)) and VLDL-C (r = 0.58; p < 0.05). It was also obtained a negative association between basal insulin and HDL-C (r = -0.89; p < 0.001). These data suggest that hyperinsulinemia in association with lipid abnormalities could appear early (before the development of Impaired Glucose Tolerance and Diabetes) in first degree relatives of NIDDM patients.

Adult↗
PubMed1995

[Quadriceps myopathy: a type of late focal dystrophy in a case].

A 62 years old male with a slowly progressive focal myopathy is presented. He had noticed weakness in the lower limbs for three years and weakness in the upper limbs for one year. He had bilateral atrophy of quadriceps and biceps muscles, absence of knee jerks and hypertrophy of the calves. Needle EMG showed myopathic motor units. Hystological study was compatible with muscular dystrophy. The clinical and laboratory characteristics of this patient are in keeping with what has been described as "Quadriceps Myopathy" as a form of a muscular dystrophy.

Biopsy↗
PubMed1994

Reptilian waking EEG: slow waves, spindles and evoked potentials.

Signal spectral analysis procedures were used to compute the power spectrum of Gallotia galloti lizards EEG at different (5-35 degrees C) body temperatures. EEG power spectra were mainly characterized by a low frequency peak between 0.5 and 4 Hz which was present at the different body temperatures. A second spectral peak, corresponding to spindles of similar pattern to the sleep spindles of mammals, also appears in the spectra. The peak frequency of the spindles increased with the body temperature. Flash evoked potentials were characterized by a slow triphasic component upon which a spindle was superimposed, adopting a morphology similar to the K complexes of mammalian sleep. The characteristics of this EEG and evoked potentials support the hypothesis of homology between the waking state of the reptiles and the slow wave sleep of mammals.

Animals↗
PubMed1994

Effects of N omega-monomethyl-L-arginine on short-term RR interval and systolic blood pressure oscillations.

The role of endothelium-derived nitric oxide (EDNO) in short-term regulation of RR interval and arterial blood pressure (BP) in conscious rats was studied with N omega-monomethyl-L-arginine (L-NMMA). RR interval and systolic BP (SBP) variability was investigated by spectral analysis procedures. L-NMMA infused intravenously (i.v.) at 1.2 mg/kg/min elicited a clear increase in blood pressure (BP), RR interval (RRI), and respiratory rate. The main spectral modifications observed during L-NMMA infusion were (a) an increase in power of lower frequency (LF, 0.02-0.20 Hz) systolic BP (SBP) oscillations, (b) a decrease in the power of middle frequency (MF, 0.20-0.60 Hz), SBP oscillations, (c) an increase in the power of respiratory (high-frequency, HF) RR oscillations, and (d) an increase in the SBP-RR correlation in the LF band. These results suggest that L-NMMA infusion induced a rearrangement in the lower frequency oscillations of SBP, in which a decrease in sympathetic activity appears to be involved. The increase in HF oscillations of the RR interval appears to be a consequence of the increase in vagal activity in response to the increase in SBP induced by L-NMMA infusion. The suggested autonomic nervous system alterations could account for the increase in the SBP-RRI correlation in the LF band after L-NMMA administration.

Animals↗
PubMed1994

Phosphorylation of microtubule-associated proteins by protein kinase CK2 in neuritogenesis.

Phosphorylation of microtubule-associated protein MAP1B and the neuronal-specific beta III-tubulin isoform takes place during neurite growth in neuroblastoma cells. Protein kinase CK2 (formerly referred to as casein kinase 2) is possibly involved in beta III-tubulin phosphorylation. As for MAP1B, there are at least two types of phosphorylation; one catalyzed by proline-directed protein kinases and another catalyzed by CK2. Protein kinase CK2 is primarily localized to the nuclei in proliferating neuroblastoma cells, whereas an increased amount of the enzyme is present in the cytoplasm of postmitotic cells bearing neurites. Treatment of neuroblastoma cells with an antisense oligonucleotide which specifically results in CK2 catalytic subunit depletion inhibits neuritogenesis. CK2 depletion is accompanied by dephosphorylation of MAP1B on the corresponding phosphorylatable sites. This dephosphorylation is paralleled by a release of MAP1B from microtubules. These results suggest that MAP1B phosphorylation by CK2 may be required for the assembly of microtubules within neurites. Other neuronal cytoskeletal proteins including MAP1A and tau are also substrates for CK2, indicating a role for the enzyme in the regulation of cytoskeletal functions also in mature neurons.

Amino Acid Sequence↗
PubMed1992

[Epidemiology, clinical course++, prognosis and treatment of thrombocytopenia associated with human immunodeficiency virus type 1 infection: analysis of 41 cases].

BACKGROUND: Thrombocytopenia is one of the manifestations of infection by the human immunodeficiency virus-1 (HIV-1). A series of 41 patients were studied over a period of 2 years. METHODS: The study was prospectively carried out with a control group of 80 patients with the epidemiology, clinical manifestations, prognosis and treatment of this process being evaluated. RESULTS: The risk groups were: intravenous drug users (IVDU) (78%), homosexuals (12%) and heterosexuals (7%), patients with thrombocytopenia as the only manifestation (group IV-E) constituted the largest group with 30 cases. In 50% of the patients both diseases (thrombocytopenia and HIV infection) were simultaneously diagnosed. Nine patients (22%) vs 35% in the control group evolved to more advanced stages of the infection. Only 39% of the cases had hemorrhagic manifestations being more frequent in the IV-E group (47%) than in the remaining patients (18%). With regards to treatment, only 1 case responded completely with danazol. Steroids had variable, although evaluable, results with minimum secondary effects. The infusion of gammaglobulins achieved 80% of complete, although transitory, responses. Zidovudine obtained a positive response in 17/25 cases. Finally, splenectomy was performed in three patients definitively resolving the thrombocytopenia. CONCLUSIONS: In thrombocytopenia associated with human immunodeficiency virus-1 (HIV-1) infection the distribution by groups of risk is equal to that of the rest of infected patients. Appearing early in the natural history of HIV infection, thrombocytopenia presents few clinical manifestations and does not constitute a factor of bad prognosis. The treatment of choice is zidovudine at doses of 500 mg/day.

Acquired Immunodeficiency Syndrome↗
PubMed1992

[Implantable devices for central venous access in cancer patients. Our experience in 217 cases].

BACKGROUND: The need of having a venous via available for infusion of chemotherapy treatment along with the difficulty of repeated venous access in oncological patients has lead to the ever more frequent placement of central venous access systems (CVAS) implanted into subcutaneous tissue. METHODS: From February 1985 to December 1990 217 CVAS were implanted in 205 oncological patients. Twenty-six were Port-a-Cath and 191 were Implantofix. RESULTS: The average of complications was 0.08/100 days of implantation with an incidence of catheter thrombosis obstruction of 0.03/100 days and system infection of 0.02/100 days. Currently 81 devices continue functioning with 23 having been withdrawn due to complications and 17 for completion of the treatment to which they had been submitted. Ninety-one patients died during this follow up. CONCLUSIONS: The CVAS are devices which are of easy placement, simple handling, requiring minimum care and few complications. Their efficacy is confirmed by the analysis of the data presented in the present study.

Adolescent↗
PubMed1992

Spontaneously diabetic biobreeding rats and impairment of bile acid-independent bile flow and increased biliary bilirubin, calcium and lipid secretion.

Chemically induced diabetes has been reported to induce profound changes in bile formation, but possible toxic effects of the streptozotocin or alloxan used cannot be excluded totally. This study was undertaken to evaluate biliary function in spontaneously diabetic female biobreeding rats with a diabetes duration of 2 wk and compare them with nondiabetic littermates. Diabetic animals evidenced glycosuria, hyperglycemia and hypoinsulinemia. Biliary concentration and secretion of bile acids, cholesterol and phospholipids were significantly increased, with no enhancement in the lithogenic index of bile. Bile flow and the biliary secretion of sodium, potassium, chloride and bicarbonate were significantly reduced despite the increased bile acid secretion. The cholestatic condition was confirmed by an increased serum concentration of bile acids and a higher activity in serum of the alkaline phosphatase liver isoenzyme. Biliary calcium concentration increased without any change in its serum concentration. A linear relationship was observed between biliary calcium and bile acid secretion. Serum concentration of unconjugated and of conjugated bilirubin was increased 1.6-fold and 8-fold, respectively, with a 1.5-fold enhanced biliary secretion of bilirubins despite the cholestasis; this points to an enhanced bilirubin production. An increased proportion of conjugated bilirubin was found in serum together with an enhanced bilirubin diconjugate/monoconjugate ratio in bile. A higher UDP-glucuronyltransferase activity and a delayed transit of bilirubin could account for these effects. Administration of insulin to diabetic animals tended to reverse the above reported changes. The spontaneously diabetic biobreeding rat thus represents a model of bile acid-independent cholestasis with enhanced biliary bile acid and calcium secretion and with presumably an enhanced bilirubin production.

Animals↗
PubMed1992

Malnutrition-related polyunsaturated fatty acid changes in plasma lipid fractions of cirrhotic patients.

Cirrhotic patients have both impaired liver function and nutritional derangement. In fact, the prevalence of protein-energy malnutrition (PEM) is very high in these patients. The aim of the present study was to elucidate whether the nutritional status in cirrhosis could be an additional factor that would affect levels of plasma lipids. Plasma lipid phosphorus, cholesterol, and triglycerides (TG), and fatty acid profiles in plasma and plasma fractions were determined in 50 healthy subjects and 92 patients with liver cirrhosis. The cirrhotic patients were prospectively included in three groups according to the result of nutritional assessment: group 1 (n = 38), acceptable nutritional status (including well-nourished and mildly malnourished patients); group 2 (n = 29), moderate PEM; and group 3 (n = 25), severe PEM. The main findings of this study were that the decrease in plasma cholesterol and linoleic, dihomo-gamma-linolenic, and arachidonic acid levels of cirrhotic patients was related to the degree of PEM. Cholesteryl esters (CE) appeared to be the most sensitive indicator of lipid changes in cirrhosis. We consider that the role of malnutrition in the changes observed for polyunsaturated fatty acid (PUFA) profiles in plasma lipids of cirrhotic patients may be of major importance, since severe malnourished subjects exhibited the lowest levels of those compounds. Dietary supplementation of both essential fatty acids (EFA) and long-chain PUFA in adequate amounts to the cirrhotic patient might be of importance in the management of the disease.

Aged↗
PubMed1992

Testicular 3 beta-hydroxysteroid dehydrogenase/delta 5-4 isomerase in the hypophysectomized rat: effect of treatment with 5 alpha-dihydrotestosterone.

The in-vivo regulatory effect of androgens on steroidogenesis was investigated. Adult (2 to 3 months old) hypophysectomized rats were treated intratesticularly with increasing doses of 5 alpha-dihydrotestosterone (DHT; 10-200 micrograms/100 g body weight) or vehicle (50 microliters dimethyl sulphoxide; DMSO) in the contralateral testis. Intratesticular testosterone concentrations were extremely low in hypophysectomized rats 15-20 days after surgery. Treatment with DHT caused a dose-dependent inhibition of testicular 3 beta-hydroxysteroid dehydrogenase/delta 5-4 isomerase (3 beta-HSD) 2 h later, and this effect was apparent at the dose of 20 micrograms/100 g body weight (P less than 0.01). The inhibitory effect of 3 beta-HSD was not due to a possible interference of DHT in the enzyme assay, since various concentrations of the androgen (0.1-100 mumol/l) were ineffective as inhibitors of 3 beta-HSD. The highest dose of DHT used in this study (200 micrograms/100 g body weight) resulted in a rapid (1-2 h) and transient (4-6 h) inhibition (approximately 80%) of 3 beta-HSD activity. Pretreatment of rats with the antiandrogen cyproterone acetate (5 mg/rat) or the protein synthesis inhibitor cycloheximide (10 mg/rat) did not affect the enzyme activity of testes injected with DMSO, but counteracted the inhibitory effect of DHT on 3 beta-HSD activity in the contralateral testis. The results presented suggest that the inhibitory effect of the non-aromatizable androgen DHT is receptor-mediated and involves the synthesis of a factor(s) that modulates 3 beta-HSD activity.

Androgens↗
PubMed1992

R5020 enhances PGE2 stimulated steroidogenesis in cultured rat granulosa cells.

Progesterone biosynthesis and metabolization to 20 alpha-hydroxyprogesterone was stimulated in granulosa cells cultured in the presence of 20 ng/ml of follicle stimulating hormone (FSH) or increasing concentrations of PGE2 (10(-9)-10(-7)M). Concurrent treatment with the synthetic progestin R5020 (10(-6) M) enhanced the FSH or PGE2 stimulated progesterone and 20 alpha-hydroxyprogesterone accumulation in culture media, as well as delta 5-3 beta-hydroxysteroid dehydrogenase activity in granulosa cell homogenates. These findings may represent another example of an autocrine control mechanism in which the steroidogenic product of the granulosa cell exerts an ultra-short loop regulation of its own production.

20-alpha-Dihydroprogesterone↗
PubMed1992

[Lymphoproliferative syndromes associated with rheumatoid arthritis].

Rheumatoid arthritis predispose to several lymphoproliferative syndromes, some of them are of doubtful neoplastic type, as the lymphoproliferative disease of granular lymphocytes, whereas others are clearly malignant, as non-Hodgkin's lymphomas and multiple myeloma. In this paper, we review the potential etiological agents, mainly the reduction of the "natural killer" activity and immunity disorders against virical oncogenes. The onset of monoclonal gammopathy in rheumatoid patients is also stressed, due to its potential prognosis value in the development of lymphoid neoplasias.

Arthritis, Rheumatoid↗