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Biomedical subjects

J Ruiz

Publications and source records attributed to J Ruiz.

At least 199 records · Page 11Linked to original sources
PubMed1997

[Spontaneous intravascular rupture of a giant neuroepithelial cyst].

We report the case of a woman presenting with a gait disorder. Magnetic resonance the brain showed a large parieto-neuroepithelial cyst. Surgery was ruled out and a new image taken nearly two years later showed the cyst cavity had collapsed spontaneously. The benign course of this type of lesion and the possibility of spontaneous recurrence suggest that a wait-and-see attitude can be chosen over surgery in patients with few clinical manifestations.

Cerebral Ventricles↗
PubMed1997

[Clinical features and ultrastructure of primary ciliary dyskinesia and Young syndrome].

A study was conducted of the clinical manifestations and ultrastructure in a series of seven patients with repeated pulmonary infections and infertility (3 cases with primary ciliary dyskinesia [PCD] and 4 with the young syndrome [YS]). Clinical and functional respiratory changes were more marked among cases of PCD. The seminogram showed azoospermia in cases with YS and hypospermia with marked hypomotility in cases with PCD. A nasal mucosa biopsy specimen was obtained from all patients to perform a transmission electron microscopy (EM) investigation. Patients with YS did not have pathognomonic ultrastructural changes, whereas patients with PCD had a large number of ciliary abnormalities (23.3% +/- 1.5%); 14% +/- 7% of them corresponded to nonspecific ciliary changes and the remaining abnormalities to congenital ciliary changes (ciliary disorientation in three cases, defective radial spokes in one case and microtubule transposition in one case). EM is a useful technique which is recommended for the differential diagnosis in this group of patients.

Adult↗
PubMed1997

[Menetrier disease associated with ulcerative colitis. Response to the treatment with octreotide. Review of the diagnostic criteria and etiopathogenesis].

The case of a patient with Ménétrier's disease in association with inactive ulcerative colitis of 7 years of evolution is presented. Diagnosis was confirmed by exploratory laparotomy and the symptoms of anemia and hypoproteinemia improved following treatment with octreotide. On review of the literature this was found to be the third case of Ménétrier's disease associated with ulcerative colitis described in the world literature. A possible relationship with an increase in alpha TGF is suggested. The diagnostic criteria and the possible etiopathogenic factors of the disease are herein reviewed.

Colitis, Ulcerative↗
PubMed1996

Increased density of I2-imidazoline receptors in human glioblastomas.

A glial location has been proposed for the non-adrenoceptor [3H]idazoxan binding site termed the I2-imidazoline receptor. The specific binding of [3H]idazoxan in the presence of (-)adrenaline was measured in membranes from excised human glioblastomas (n = 6), meningiomas (n = 6) and normal brains (n = 6). The pharmacological profile of the [3H]idazoxan binding in astrocytic tumours was similar to that in normal brain, compatible with the presence of I2-imidazoline receptors. There was a higher density of I2-imidazoline receptors in astrocytic tumours (Bmax = 266 +/- 18 fmol mg-1 protein; p < 0.001) than in normal brain (Bmax = 54 +/- 4 fmol mg-1 protein), with no differences in affinity values. Almost no [3H]idazoxan-specific binding was shown in meningiomas. The results suggest that I2-imidazoline receptors may be a selective marker for glial tumours in the evaluation of intracranial neoplasms.

Aged↗
PubMed1996

[Acute lipoid pneumonia. Report of 2 cases].

Lipoid pneumonia is a chronic infiltrative pulmonary process secondary to continued aspiration of exogenous lipids (laxatives and nasal drops). On occasions, an acute form of lipoid pneumonia which may lead to respiratory failure may be observed coinciding with accidental massive aspirations of lipidic material. Two cases of acute lipoid pneumonia secondary to paraffin aspiration in << fire eaters >> are presented.

Accidents, Occupational↗
PubMed1996

Evaluation of flow injection sample to standard addition method for the inductively coupled plasma mass spectrometric determination of aluminium in biological tissues.

An on-line flow injection sample to standard addition method was developed for the determination of aluminium in biological tissues by inductively coupled plasma mass spectrometry. The sample concentration is calculated from two transient signals obtained from the injection of the blank and the sample, using a standard solution as carrier. A flow injection manifold for the on-line injection of both solutions was used and a three-step flow injection programme allowing the two transient signals to be obtained in the same measurement process was applied. A microwave nitric acid digestion procedure in closed vessels was used for sample dissolution, and scandium was added as an internal standard to control plasma fluctuations and to correct for ion signal instability. Tissue samples from healthy rat brain, kidney, liver, lung and spleen were analysed to find their aluminium concentrations. Complete recoveries from rat liver tissue spiked with aluminium concentrations in the 0.5-10.0 micrograms g-1 level were achieved. The detection limit (3 sigma) referred to the solid sample was of 10 ng g-1 and the precision (RSD) was better than 1%. The accuracy of the proposed method was tested by determining the aluminium contents in two NIST Standard Reference Materials: SRM 1577b Bovine Liver and SRM 8414 Bovine Muscle Powder).

Aluminum↗
PubMed1996

Comparative study of the corrosion behavior of MA-956 and conventional metallic biomaterials.

In this work the corrosion behavior of a new biomaterial, the MA-956 superalloy, immersed in Hank's solution is evaluated. A comparison with conventional metallic alloys used as articular implants is established. To determine the corrosion behavior we employed electrochemical methods: evaluation of corrosion potential Ecorr, electrochemical impedance spectroscopy (EIS), and anodic polarization curves. The corrosion resistance of the MA-956 superalloy preoxidized at 1100 degrees C during 100 h is at least two orders of magnitude higher than for the other alloys. This satisfactory behavior is stationary with time. Also the probability of the appearance of the pitting corrosion process is very low. When cracking is generated in the alpha-alumina layer the repassivation process is assured because of the high Cr content in the superalloy. This study is the first step in proposing this new alloy as a biomaterial. The low toxicity of these metallic alloys in the physiological environment suggests that in vivo their biocompatibility could be satisfactory.

Alloys↗
PubMed1996

Performance of six culture media for isolation of Salmonella species from stool samples.

The relative performance of five plating media [Rambach agar; salmonella-shigella (SS) agar, novobiocin-brilliant green-glycerol-lactose (NBGL), modified semisolid Rappaport-Vassiliadis medium (MSRV), and Salmonella Detection and Identification-2 (SM2)] and selenite broth (SB) subcultured in SS agar in the recovery of Salmonella spp. from 500 human stool specimens was evaluated. On Rambach agar and SS agar, the C8-esterase test was also used for selection of suspicious colonies. Eighty-one samples were positive for salmonellae on at least one of the six media. Sensitivities and specificities of MSRV, SB, NBGL, SS, Rambach agar, and SM2 were 95.1 and 98.1%, 87.6 and 99.8%, 79 and 91.9%, 69.1 and 99.3%, 56.8 and 96.9%, and 54.3 and 92.4%, respectively. There were statistically significant differences between MSRV and NBGL, Rambach agar, SS agar, and SM2 (p < 0.005), between SB and SS agar, Rambach agar, and SM2 (p < 0.05), and between NBGL and SM2 and Rambach agar (p < 0.005). The greatest number of isolates was recovered with MSRV, whose performance surpassed that of enrichment in selenite broth, probably because the subcultures were not repeated on MSRV. This hypothesis is now under investigation. The specificity of each of the five solid media was greater than 90%.

Bacteriological Techniques↗
PubMed1996

Effects of vanadyl sulfate on carbohydrate and lipid metabolism in patients with non-insulin-dependent diabetes mellitus.

The safety and efficacy of vanadyl sulfate (VS) was tested in a single-blind, placebo-controlled study. Eight patients (four men and four women) with non-insulin-dependent diabetes mellitus (NIDDM) received VS (50 mg twice daily orally) for 4 weeks. Six of these patients (four men and two women) continued in the study and were given a placebo for an additional 4 weeks. Euglycemic-hyperinsulinemic clamps were performed before and after the VS and placebo phases. VS was associated with gastrointestinal side effects in six of eight patients during the first week, but was well tolerated after that. VS administration was associated with a 20% decrease in fasting glucose concentration (from 9.3 +/- 1.8 to 7.4 +/- 1.4 mmol/L, P < .05) and a decrease in hepatic glucose output (HGO) during hyperinsulinemia (from 5.0 +/- 1.0 pre-VS to 3.1 +/- 0.9 micromol/kg x min post-VS, P < .02). The improvement in fasting plasma glucose and HGO that occurred during VS treatment was maintained during the placebo phase. VS had no significant effects on rates of total-body glucose uptake, glycogen synthesis, glycolysis, carbohydrate (CHO) oxidation, or lipolysis during euglycemic-hyperinsulinemic clamps. We conclude that VS at the dose used was well tolerated and resulted in modest reductions of fasting plasma glucose and hepatic insulin resistance. However, the safety of larger doses and use of vanadium salts for longer periods remains uncertain.

Blood Glucose↗
PubMed1996

Idiopathic stabbing headache (jabs and jolts syndrome)

The clinical features of idiopathic stabbing headache ("jabs and jolts syndrome") were studied in 38 patients who were diagnosed throughout a 1-year period. Mean age at the onset of symptoms was 47.1 years +/- 14.5 (SD), and a clear female preponderance was demonstrated (female/male ratio = 6.6). Painful attacks were ultrashort, i.e. virtually all attacks in more than two thirds of cases lasted only one second. The frequency of attacks varied immensely, ranging from 1 attack per year to 50 attacks daily. The pain paroxysms usually occurred with an irregular or sporadic temporal pattern. The localization of painful attacks was reported frequently as unifocal, usually in the orbital area, but also multifocal patterns were observed, the attacks frequently changing location from one area to the next. The majority of attacks occurred spontaneously, and accompanying phenomena were reported only rarely. Indomethacin treatment (75 mg daily) seemed to have a complete or partial effect in most patients treated as such (n = 17).

Adult↗
PubMed1996

Note: comparison of media for the isolation of lactose-positive Salmonella.

We studied the capacity of 10 selective media (Rambach agar, RB; salmonella-shigella agar, SS; SM-ID medium, SM; Hektoen enteric agar, HE; modified semisolid Rappaport-Vassiliadis agar, MSRV; bismuth sulphite agar, BS; MacConkey agar, MC; brilliant green agar, BG; novobiocin-brilliant green-glucose agar, NBG; and novobiocin-brilliant green-glycerol-lactose agar, NBGL), and the C8-esterase test (MUCAP test, Biolife, Italy) to detect the growth of 14 strains of lactose-positive Salmonella (12 Salm. virchow and two Salm. montevideo) and 16 Salm. arizonae. Suspensions of pure strain were plated on the aforementioned media and on Mueller-Hinton, used as a control, with inocula of 3 x 10(2) cfu ml-1. The performance of BS was excellent, determining the 30 strains as typical Salmonella colonies (H2S+). On NBG, 27 strains were detected. On MSRV, only some strains grew and only one produced swarming. On the other media, the two Salm. montevideo and the 12 Salm. virchow strains produced coliform colonies. Some of these latter were inhibited on BG and NBGL. The 16 Salm. arizonae strains produced typical colonies on all the media, except on RB, SM and MSRV. On NBGL, two strains did not produce H2S. The C8-esterase test was only successful with Salm. montevideo and Salm. virchow on NBG and RB (with a few exceptions on the latter). However, with Salm. arizonae the test was positive on SS, MC, HE, BG and NBG. In summary, BS was the best medium of those used (all the 30 strains were isolated), followed by NBG (27 isolates).

Culture Media↗
PubMed1996

Detection of mutations in parC in quinolone-resistant clinical isolates of Escherichia coli.

The gene parC encodes the A subunit of topoisomerase IV of Escherichia coli. Mutations in the parC region analogous to those in the quinolone resistance-determining region of gyrA were investigated in 27 clinical isolates of E. coli for which ciprofloxacin MICs were 0.0007 to 128 micrograms/ml. Of 15 isolates for which ciprofloxacin MICs were > or = 1 microgram/ml, 8 showed a change in the serine residue at position 80 (Ser-80), 4 showed a change in Glu-84, and 3 showed changes in both amino acids. No mutations were detected in 12 clinical isolates for which ciprofloxacin MICs were < or = 0.25 micrograms/ml. These findings suggest that ParC from E. coli may be another target for quinolones and that mutations at residues Ser-80 and Glu-84 may contribute to decreased fluoroquinolone susceptibility.

Anti-Infective Agents↗
PubMed1996

Use of AmpliWax to optimize amplicon sterilization by isopsoralen.

The photochemical inactivation of amplicons by isopsoralen (IP-10) has been suggested as a possible means to prevent PCR carryover contamination. To evaluate the technique, serial dilutions of amplicons (10(11) to 10(3)) from the Borrelia burgdorferi OSP A gene were amplified in the presence of 0, 25, 50, and 100 micrograms of IP-10 per ml for 45 cycles. The PCR products were exposed to UV light for 15 min to activate IP-10 and sterilize the amplicons. One microliter of each sterilized sample was reamplified for an additional 45 cycles. The PCR products were then resolved in an agarose gel, blotted onto a nylon membrane, and probed with an alkaline phosphatase-conjugated chemiluminescent probe. Although IP-10 at concentrations of 50 and 100 micrograms/ml effectively sterilized up to 10(11) amplicons, the compound was inhibitory to PCR. IP-10 at a concentration of 25 micrograms/ml had slight inhibitory effect on PCR and did not completely sterilized all of the amplicons. Therefore, in subsequent experiments AmpliWax was substituted for mineral oil, and PCR was performed on 10(9) to 10(3) amplicons as described above. Following the amplification, the PCR tubes were cooled to solidify the AmpliWax and inoculated with various concentrations of IP-10. With this technique, PCR products produced from as many as 10(9) target amplicons were effectively sterilized with 200 micrograms of IP-10 per ml. Similarly, the addition of IP-10 (50 micrograms/ml) before and after PCR was evaluated for the detection of B. burgdorferi in 62 ticks from a region of Southern Connecticut where the organism is highly endemic. PCR performed in the presence of 50 micrograms of IP-10 per ml detected B. burgdorferi-specific DNA in 17 of 62 ticks (27%) following gel electrophoresis and in 34 of 62 ticks (55%) following Southern blot hybridization of the PCR products. In contrast, post-PCR addition of IP-10 detected borrelia-specific DNA in 31 of 62 ticks (50%) following gel electrophoresis and in 46 of 62 ticks (64%) following Southern blot hybridization. We conclude that the replacement of mineral oil with AmpliWax can be useful in eliminating the inhibitory effects of IP-10 and other sterilizing agents for post-PCR sterilization of amplicons.

Animals↗
PubMed1996

Comparison of five plating media for isolation of Salmonella species from human stools.

A comparative study was carried out to evaluate the performances of different culture media for the recovery of Salmonella spp. from 1,000 routine samples of human stools. By direct plating we tested Salmonella-Shigella agar (SS), Hektoen enteric agar (HE), bismuth sulfite agar (BS), novobiocin-brilliant green-glycerol-lactose agar (NBGL) and SM-ID medium (SM), and after selenite enrichment, we tested all of the media except HE. C8-esterase and oxidase tests were used for the screening of Salmonella spp. on SS and HE. The total number of Salmonella isolates from direct culture was 74, with respective sensitivities and positive predictive values (PPVs) of 78.4 and 61%, 64.9 and 18.7%, 36.5 and 34.2%, 55.4 and 20.7%, and 39.2 and 43.9% for NBGL, SS, HE, BS, and SMID, respectively. After enrichment, the total number of Salmonella isolates was 88. The respective sensitivities and PPVs obtained were 90.9 and 62.5%, 92 and 17%, 90.9 and 32% and 93.2 and 71.3% for NBGL, SS, BS, and SM, respectively. According to our results, NBGL in direct plating was the medium with the highest sensitivity with respect to the sensitivities of the other media, with significant statistical differences (P < 0.05). Likewise, the PPV for NBGL was also the highest (61%). After enrichment in selenite broth, the sensitivities of the four media tested were similar, with the best PPV obtained with SM (71.3%); this was followed by NBGL (62.5%). When C8-esterase was used on SS or HE, the PPVs improved from less than 40% to about 100%.

Culture Media↗
PubMed1996

Effects of prolonged glucose infusion on insulin secretion, clearance, and action in normal subjects.

It was the aim of this study to determine whether prolonged hyperglycemia can produce "glucose toxicity" in normal human subjects. To this end, plasma glucose was clamped at approximately 5, approximately 8.8, and approximately 12.6 mM for 68 h in healthy volunteers. Rates of insulin secretion (by deconvolution of plasma C-peptide) and rates of insulin clearance [area under curve (AUC) 24 h insulin secretion/AUC 24 h insulin] were determined. Pre- and posthyperglycemia glucose turnover was measured (with [6,6-2H2]glucose) during euglycemic-hyperinsulinemic clamping to assess peripheral (muscle) and hepatic insulin action. Hyperglycemia (approximately 12.6 mM) for 68 h was associated with significant reductions in rates of insulin secretion (-35%, P < 0.05), insulin clearance (-57%, P < 0.05), glucose infusion rates needed to maintain hyperglycemia (-36%, P < 0.05), and insulin-stimulated glucose uptake (-55%, P < 0.01). No significant changes were seen during approximately 8.8 mM hyperglycemia or during euglycemia. These data showed that 12.6 mM hyperglycemia, but not 8.8 mM hyperglycemia or euglycemia, was associated with reduced insulin secretion, insulin clearance, and peripheral (muscle) insulin action. We concluded that 1) in normal subjects, desensitization to glucose involving beta-cells and muscle developed at plasma glucose concentrations between approximately 9 and approximately 12 mM, and 2) these effects were partially compensated for by a decrease in insulin clearance.

Adult↗