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Biomedical subjects

J Ruiz

Publications and source records attributed to J Ruiz.

At least 235 records · Page 13Linked to original sources
PubMed1995

Systemic infections in three infants due to a lactose-fermenting strain of Salmonella virchow.

Three previously healthy children developed gastroenteritis which led within a few days to systemic infections, two cases of bacteremia and one of meningitis. A lactose-fermenting Salmonella virchow strain was isolated from cerebrospinal fluid and blood cultures. In one case, this strain was also isolated from stool cultures. All the children had been fed the same milk formula. There was no other relationship between them. The batch of dried-milk formula was confirmed as the source of the infection by isolation of an identical lactose-fermenting Salmonella virchow strain by the Centro Nacional de Alimentación.

Anti-Bacterial Agents↗
PubMed1995

Non-enzymatic glycation of lipoprotein(a) in vitro and in vivo.

Nonenzymatic glycation of lipoprotein may contribute to the premature atherogenesis of patients with diabetes mellitus by diverting lipoprotein catabolism from non-atherogenic to atherogenic pathways. It has been demonstrated that the proportion of apolipoprotein B-100 (apo B-100) in glycated form is significantly higher in diabetic patients than in non-diabetic controls, and equally that plasma lipoprotein(a) Lp(a) levels may be increased in diabetic patients. Consequently, we have evaluated the glycation of Lp(a) in vitro and in vivo, by use of a combination of m-aminophenylboronate affinity chromatography and enzyme-linked immunosorbent assay (ELISA) for apo B-100 and Lp(a). In vitro studies were performed on normolipodemic plasma samples containing elevated concentrations of Lp(a). These studies establish that Lp(a) can be glycated in vitro in the presence of high concentrations of glucose, although to a lesser extent than low density lipoprotein (LDL) (15.8% +/- 4.4% and 30.2% +/- 5.4% (P = 0.0001) after a 48 h incubation at 37 degrees C, respectively). We have also shown that apo B-100 was more glycated than apo(a) in the Lp(a) particle. In vivo studies have shown that the percentage of glycated Lp(a) in diabetic patients was significantly higher than in the control population (2.8% +/- 1.07% versus 2.0% +/- 0.43%, P = 0.017). The level of glycated Lp(a) is also positively correlated with that of HbA1c in diabetic patients (r=0.6, P=0.002). Since our results show that Lp(a) is less susceptible to glycation than LDL, we speculate that glycation of LDL may be more relevant to the cardiovascular risk associated with this particle than with Lp(a).

Apolipoprotein B-100↗
PubMed1995

Release, oxidation, and reesterification of fatty acids from infused triglycerides: effect of heparin.

We have investigated the effects of heparin on rates of fatty acid (FA) release, oxidation, and reesterification from intravenously (IV) infused triglycerides (TGs) during euglycemic (4.7 mmol.L-1) hyperinsulinemia (approximately 450 pmol.L-1). Four healthy men (aged 31 +/- 3 years; body mass index, 26.1 +/- 0.9 kg/m2) received i.v. TGs (1.02 mmol TG.kg-1.4 h-1), four other men (aged 24.3 +/- 2.8 years: body mass index, 24.7 +/- 1.7 kg/m2) received TGs plus heparin (200-U bolus followed by 0.4 U.kg-1.min-1), and nine men and one woman (aged 28.8 +/- 2.3 years; body mass index, 23.1 +/- 0.9 kg/m2) received saline (controls). Heparin increased lipolysis from infused TGs (to 1.0 +/- 0.1 from 0.3 +/- 0.1 mmol.kg-1.4 h-1, P < .01), increased plasma free fatty acids ([FFA] to 737 +/- 32 from 597 +/- 136 mumol.L-1, P < .05). and increased FA reesterification (to 0.84 +/- 0>14 from 0.18 +/- 0.12 mmol.kg-1.4 h-1, P < .02), but had no effect o n FA oxidation (0.13 +/- 0.02 v 0.12 +/- 0.04 mmol.kg-4 h-1) or net energy gain (167 +/- 42 v 243 +/- 79 kJ.4 h-1). In summary, addition of heparin (1) increased lipolysis (to approximately 98% from approximately 29%) and reesterification (to approximately 82% from approximately 17%) of infused TG, but had no significant effects on fat oxidation (approximately 12%) and net energy gain. We conclude that heparin accelerated removal of infused lipid from the blood and its deposition into endogenous fat depots. Since the doses of heparin and insulin used in this study were higher than those generally used in total parenteral nutrition protocols, our results may not be strictly applicable to the usual clinical situation.

Adult↗
PubMed1995

Screening for asymptomatic celiac sprue in families.

We evaluated the reliability of IgA and IgG antigliadin antibodies (AGA-A, AGA-G), antireticulin antibody (ARA), endomysial antibodies (EmA), and alpha 1-antitrypsin clearance (alpha 1-AT CL) in the detection of celiac sprue (CS) in 59 first-degree asymptomatic relatives of celiac patients who had duodenal biopsy. Twenty-four relatives who had normal results of screening tests were selected at random for biopsy; 35 relatives with at least one abnormal test result were biopsied. Eleven relatives were noted to have villous atrophy at biopsy; the diagnosis of celiac sprue was confirmed by histological improvement after gluten-free diet in six. AGA-G, alpha 1-AT CL, and EmA had sensitivities of 73%, 73%, and 64%, respectively, with very high levels of specificity. Sensitivity was improved by the combination of two serological markers (AGA-G + alpha 1-AT CL = 91%; AGA-G + EmA = 82%; EmA + ARA = 82%). Furthermore, combination of EmA and ARA has shown the best specificity and positive predictive value. AGA-G, alpha 1-AT CL, and EmA are reliable individual markers for the detection of asymptomatic celiac sprue. However, a combination of two of them, including ARA, was more sensitive than the individual tests.

Biomarkers↗
PubMed1995

Factors influencing the low density lipoprotein profile in type 2 diabetic patients.

The lipoprotein distribution profile was examined in Type 2 (non-insulin-dependent) diabetic patients (n = 52), with particular emphasis on factors influencing low density lipoproteins (LDL). Triglycerides were negatively correlated with LDL-2 (r = 0.34, p < 0.05) and positively correlated with smaller, denser LDL-3 (r = 0.57, p < 0.001). This yielded a highly significant, negative correlation between triglycerides and the LDL-2/LDL-3 mass ratio (r = -0.59, p < 0.001) which is an indication of the presence of smaller LDL particles. Parameters of glycaemic control, in the form of fasting blood sugar and glycated haemoglobin (HbA1c), were also negatively correlated with the LDL-2/LDL-3 mass ratio in univariate analyses; both remained significantly correlated with the mass ratio when corrected for triglycerides. Stepwise multiple regression analysis identified a three-parameter model comprising triglycerides, HbA1c, and high density lipoprotein cholesterol as best defining the variations in the LDL-2/LDL-3 mass ratio (adjusted r2 = 0.52). These observations are consistent with an independent impact of diabetes on the LDL distribution profile and the possibility that the latter may be subjected to multiple pathological influences in diabetic patients.

Analysis of Variance↗
PubMed1995

Mutation in the gyrA gene of quinolone-resistant clinical isolates of Acinetobacter baumannii.

The gyrA gene mutations associated with quinolone resistance were determined in 21 epidemiologically unrelated clinical isolates of Acinetobacter baumannii. Our studies highlight the conserved sequences in the quinolone resistance-determining region of the gyrA gene from A. baumannii and other bacteria. All 15 isolates for which the MIC of ciprofloxacin is > or = 4 micrograms/ml showed a change at Ser-83 to Leu. Six strains for which the MIC of ciprofloxacin is 1 microgram/ml did not show any change at Ser-83, although a strain for which the MIC of ciprofloxacin is 1 microgram/ml exhibited a change at Gly-81 to Val. Although it is possible that mutations in other locations of the gyrA gene, the gyrB gene, or in other genes may also contribute to the modulation of the MIC level, our results suggest that a gyrA mutation at Ser-83 is associated with quinolone resistance in A. baumannii.

4-Quinolones↗
PubMed1995

Peripheral serotonin in Alzheimer's disease.

The platelet has been suggested to be a peripheral model of the central serotonergic neuron. This investigation was carried out in order to test the hypothesis that levels of serotonin (5-HT) in the platelet will be decreased in Alzheimer's disease (AD) since neurochemical studies suggest that levels of 5-HT are decreased in the brain of AD patients. We investigated platelet and plasma 5-HT in a group of AD patients (n = 22) as well as in age-matched normal control subjects (n = 20). The results show that the platelet level of 5-HT was significantly reduced in AD (65.7 +/- 28.41 ng/10(8) platelets in AD vs. 112.9 +/- 35.11 ng/10(8) platelets in controls; p = 0.0001). There was no effect on the levels of its metabolite 5-hydroxyindoleacetic acid. These findings suggest that the peripheral serotonergic system in AD is adversely affected.

Aged↗
PubMed1995

Bacterial infection in chronic obstructive pulmonary disease. A study of stable and exacerbated outpatients using the protected specimen brush.

The lower airways of asymptomatic chronic obstructive pulmonary disease (COPD) patients can be colonized by bacteria, mainly Haemophilus influenza, Streptococcus pneumoniae, and Moraxella catarrhalis. However, the role of lower airway bacteria in stable and exacerbated COPD has not been well defined. To determine the importance of lower airway bacterial infection in COPD we studied 40 outpatients with stable COPD (Group A: age 61.1 +/- 9.9 yr; [mean +/- SD]; FEV1/FVC 51.7 +/- 12.5) and 29 outpatients with exacerbated COPD (Group B: age 63.4, SD 9.0 yr; FEV1/FVC 52.0, SD 9.6), using the protected specimen brush (PSB) for microbiology sampling. Group A consisted of outpatients with stable COPD having normal or near-normal chest X-rays, with clinical indications for performing fiber-bronchoscopy (pulmonary nodule, remote hemoptysis); Group B consisted of patients with exacerbated COPD who voluntarily accepted lower airway microbiology sampling. To avoid contamination by upper airway flora the PSB was used for bacterial sampling in all the cases and concentrations > or = 1,000 colony-forming units/milliliter (CFU/ml) were considered positive. Results were as follows: Group A: Lung function data in outpatients with stable COPD were lower than the reference values for this population (FVC 2.97 +/- 1.02 L, FVC% 71.4 +/- 22.4, FEV1 1.59 +/- 0.79 L, FEV1% 51.2 +/- 23.0). Positive PSB cultures were obtained in 10 of 40 cases (25%), mainly of H. influenzae and S. pneumoniae. Two of 40 cases had positive cultures at concentrations > or = 10,000 CFU/ml (5.0%).(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Infections↗
PubMed1995

[Posterior cortical atrophy with progressive visual agnosia].

Interest in progressive focal cerebral syndromes associated with classical degenerative diseases has increased in recent years. Descriptions of posterior cortical atrophy with progressive visual agnosia are relatively rare. We present 5 patients (2 women) ranging in age between 57 and 72 years old. In all cases symptoms began and progressed with no known etiology. All cases were sporadic. The main clinical signs are difficulty in recognizing objects, colors, persons or places; topographical disorientation and visual memory alterations; alexia, simultagnosia, loss of ocular fixing and optic ataxia. Some patients presented other disturbances of praxis or memory and 2 progressed to global dementia. Language function was preserved and behavioral disturbances did not develop. The amplitude of the P100 visual evoked potential was low but latency was normal in 4 patients and prolonged in 1. Brain images showed atrophy and hypoperfusion in the parieto-occipital area. The neuropathology status of these patients is unknown.

Adult↗
PubMed1995

[Use of+Rambach agar for the detection of Salmonella in feces using broth enrichment. Comparison with our methodology].

BACKGROUND: A comparative study between Rambach agar and our previously published methodology (Salmonella-Shigella agar + C8-esterase test) was carried out to isolate Salmonella from 815 stools samples after enrichment in selenite broth. METHODS: On Rambach agar all pink and colourless colonies which were oxidase negative and red colonies were also identified. On SS agar, black colonies and colourless colonies which were oxidase negative and C8-esterase test positive were identified biochemically. RESULTS: One hundred and twenty-three colourless, 81 pink and 112 red colonies grown in Rambach agar, and they were subcultured in Kliger agar yielding 7, 2 and 109 Salmonella, respectively. From SS agar, the 113 black and 10 colourless colonies which had previously been positive in the C8-esterase test and oxidase-negative, yielded 113 Salmonella strains (111 and 2, respectively). CONCLUSIONS: Rambach agar is an excellent media for isolating Salmonella after enrichment in selenite broth. If all colourless and pink colonies are further investigated the number of isolates will increase although the workload will increase, too. Therefore, it would be interesting to study a combination of C8-esterase and Rambach agar since it could reduce the workload.

Agar↗
PubMed1995

[Temporal threshold for middle cerebral artery infarction].

We describe a rat model for middle cerebral artery occlusion and discuss its usefulness for the study of structural consequences of various ischemic periods. We inserted 4/0 polyethylene sutures into the external carotid artery of 48 Wistar rats. The tips were rounded and coated with a thin layer of dental silicone. By inserting a section 18 mm long we assured that placement of the tip was between the origins of the middle and anterior cerebral arteries. The suture was withdrawn at predetermined times to allow complete reflux through the common carotid. The animals were sacrificed 24 hours after this procedure and tested for the presence of infarct by staining with 2,3,5 triphenyl-tetrazolium on 2 mm coronal cuts. We identified several differences regarding areas of infarction after the different occlusion periods, as shown by ANOVA and Newman-Keuls testing. Thus, occlusion for 15 minutes did not provoke infarction; occlusion of 30, 45 and 60 minutes produced selective infarction of the caudate nucleus and putamen; and finally, incomplete cortical infarction appeared after 90 minutes and was complete after 2 hours, at which time infarction was similar to that seen after 24 hours of occlusion. Intravascular occlusion is a reliable method for inducing focal cerebral ischemia, enabling us to confirm the existence of an infarction time threshold that is longer for the cortex than for the caudate nucleus and putamen.

Animals↗
PubMed1995

[Spontaneous internal carotid artery dissection as a cause of unilateral lower cranial nerve palsies].

We present a 60-year-old man with a complete right IX-XII nerve palsy (Collet-Sicard syndrome) due to spontaneous right internal carotid artery (ICA) dissection. Magnetic resonance imaging (MRI) and MR angiography (MRA) showed signs of subadventitial dissection of the right ICA with a mural haematoma that expanded the circumference of the vessel at the level of the retrostyloid space, adjacent to the IX-XII nerves. No narrowing of the lumen or aneurysms was found. Clinical recovery was excellent after treatment with only antiplatelet drugs. Cervical internal carotid artery dissection should be included in the differential diagnosis of lower cranial nerve palsies. MRI and MRA are noninvasive, reliable methods for diagnosis and follow-up, especially in subadventitial dissections.

Bulbar Palsy, Progressive↗