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Biomedical subjects

E Rodríguez

Publications and source records attributed to E Rodríguez.

At least 109 records · Page 6Linked to original sources
PubMed1999

[Presence of Clostridium perfringens in meat-based preparations in public food services in central San Jose, Costa Rica].

In Costa Rica there are a large number of public food services distributed along the country, where a considerable number of people eat daily. Clostridium perfringens is a bacteria associated with foodborne illness related, especially, to meat products kept for long time at temperatures under 70 degrees C. The aim of this study was to evaluate the public food services that use water baths for keeping food hot in order to establish the presence of C. perfringens in cooked bovine meat dishes and to evaluate the enterotoxigenic capacity of the strains isolated. 81 samples of cooked bovine meat plates coming from 27 public food services, located in the Central County of San José were analyzed. The methodology described by Labbe & Harmon for the isolation of C. perfringens was used in 10 g of sample. Also, the enterotoxigenic capacity of the strains was evaluated using the passive-reverse-latex-agglutination assay from Oxoid. From the 27 public food services analyzed, eight (30%) were positive in the three samplings done, nine (33%) were positive in one or two occasions, and ten (37%) were negative all times. This implies that in 17 (63%) of the establishments studied, the bacteria was isolated at least once. From the 81 preparations studied, 37 (46%) were positive for the bacteria. The temperatures at which food was kept varied from 56 to 82 degrees C, with an average of 68.7 degrees C. From the 37 strains identified as C. perfringens, 12 (32%) were positive for enterotoxin. In conclusion, the presence of C. perfringens in bovine meat dishes, maintained in water baths, represents an important risk for public health, and the temperature at which the preparation is kept is critical for the multiplication of the bacteria.

Animals↗
PubMed1999

[Determination of clostridium perfringens in pork sausages from the Metropolitan area of Costa Rica].

The presence of C. perfringens was analyzed in 75 samples of pork sausages (chorizo, salchichon and bologna), obtained from five processing plants located in the Metropolitan Area of Costa Rica. Previously and after the biochemical identification of the strains, the most probable number (MPN) of C. perfringens per gram of food was determined and it varied from less than 3 to more than 2.4 x 10(5). There were significant statistical differences (p < 0.005) that support the need of employing biochemical tests for confirming C. perfringens in a given food. C. perfringens was present in 92% of the chorizos, in 28% of the bolognas and in 12% of the salchichon. Every positive sample was tested looking for at least one enterotoxigenic strain, using the reverse passive agglutination latex test; 8% of the tested strains were enterotoxigenic and corresponded to chorizo and bologna from one processing plant and chorizo from another plant. The results obtained in this study show that pork sausages, and not just not processed meats, are important as risk factors for food intoxication by C. perfringens.

Agglutination Tests↗
PubMed1998

Acrosome reaction inactivation in sea urchin sperm.

Acrosome reaction inactivation (ARI) is a process that renders sperm irreversibly refractory to the egg jelly (the natural inducer of the acrosome reaction, AR). This process triggered by the egg jelly, is associated with an increase in [Ca2+]i. However, we show here that a rise in [Ca2+]i alone is not sufficient to induce ARI, since artificially increasing [Ca2+]i with either an ionophore or rising external pH, does not trigger ARI. Contrary to the AR which strictly requires Ca2+, ARI can be triggered almost equally well by Sr2+. On the other hand, Mn2+ inhibits ARI and, as we showed earlier, does not affect AR. These observations indicate that the mechanisms involved in ARI differ from those leading to AR. In addition, we report here that high external pH (a non-physiological inducer of AR) triggers the AR in previously inactivated sperm by opening the same Ca2+ channels activated by the egg jelly. Considering that the opening of Ca2+ channels is one of the earliest responses triggered by the egg jelly and that ARI requires the egg jelly receptor to be activated, we have concluded that ARI involves the uncoupling between the egg jelly receptor and Ca2+ channels. Furthermore, intracellular pH (pHi) determinations, in the presence or absence of ionomycin to substitute for the uncoupled Ca2+ channels, indicate that pHi regulation is also impaired in inactivated sperm. In conclusion, ARI is a manifestation of the uncoupling of the egg jelly receptor from the different ion transport systems required for the acrosome reaction.

Acrosome↗
PubMed1998

Inhibitory activity of a nisin-producing starter culture on Listeria innocua in raw ewes milk Manchego cheese.

The inhibitory activity of nisin-producing Lactococcus lactis subsp. lactis ESI 515 on the survival of Listeria innocua during ripening of raw ewes milk Manchego cheese was investigated. After 60 days of ripening, counts of L. innocua in cheese were 4.08 log units lower than the control when Lc. lactis subsp. lactis ESI 515 was used as a single-strain starter. Nisin activity was detected in cheeses manufactured with Lc. lactis subsp. lactis ESI 515 throughout the ripening period.

Animals↗
PubMed1998

Magnetic resonance imaging of congenital abnormalities of the thoracic aorta.

This article outlines the ability of MR imaging in the detection and presurgical evaluation of congenital abnormalities of the thoracic aorta (CATA). Congenital abnormalities of the thoracic aorta may be found incidentally on chest radiographs in patients without symptoms, or it can be associated with clinical findings which are very variable depending on the association with congenital cardiac malformations or vascular ring. When CATA is suspected as the cause of anomalies in the mediastinum in asymptomatic patients, confirmation of the abnormality should be by MR imaging allowing precise evaluation of the thoracic aorta and origin of the principal arteries. When CATA is considered because clinical findings indicate coarctation of the aorta, vascular ring or associated cardiac disorder, evaluation with ultrasound can be complemented by MR, which in most cases will replace the diagnostic catheterization.

Adolescent↗
PubMed1998

Fibrosing mediastinitis: CT and MR findings.

The aim of this study is to present the computed tomography (CT) and magnetic resonance (MR) findings in three cases of fibrosing mediastinitis, probably secondary to tuberculosis. Two patients had diffuse involvement of the mediastinum and one patient presented with a posterior mediastinal mass. On CT, the patients with diffuse involvement showed infiltrating soft-tissue masses with multiple foci of dense calcifications. One of these lesions enhanced mildly with contrast and one did not enhance. On MR examination, diffuse masses were of heterogeneous, intermediate and low signal on T1-weighted images (n = 2) and were of homogeneous low signal (n = 1) or heterogeneous (n = 1) signal intensity on T2-weighted images. After administration of Gd-DTPA, these mediastinal masses showed heterogeneous enhancement. The posterior mediastinal mass showed homogeneous pronounced enhancement on CT and was homogeneous with intermediate T1 signal intensity and hypointense T2 signal intensity. The CT findings of an infiltrative or well-defined mediastinal mass with scattered calcifications should suggest the diagnosis of fibrosing mediastinitis in the appropriate clinical setting. Although the appearance of calcification on MR are not specific, this technique provides further information than CT especially in those cases in which the lesions appear noncalcified, because MR imaging revealed areas of low signal intensity characteristic of fibrous tissue.

Adult↗
PubMed1998

Congenital ocular motor apraxia associated with myopathy, external hydrocephalus and NADH dehydrogenase deficiency.

Congenital ocular motor apraxia (COMA), first described by Cogan [Trans Am Acad Ophthalmol Otolaryngol 1952;56:853-862], is a rare disorder characterized by impairment of voluntary and optically induced horizontal eye movements and compensatory head thrust. The causes and pathogenesis of COMA are poorly understood. It frequently occurs in association with other neurologic abnormalities including non-progressive congenital disorders of the central nervous system (CNS), various systemic diseases and chromosomal alterations. Here, we report the case of a 6-month-old girl with psychomotor retardation, myopathy and clinical features of COMA, associated with external hydrocephalus and mitochondrial dysfunction (partial deficiency of the respiratory-chain enzyme NADH dehydrogenase). In view of this finding, we recommend that tests to characterize patients with COMA should include determination of blood levels of lactic and pyruvic acid.

Apraxias↗
PubMed1998

Detection of specific bacteriocin-producing lactic acid bacteria by colony hybridization.

A colony hybridization method for detecting lactic acid bacteria encoding specific bacteriocins was developed. Specific PCR-generated probes were used to detect colonies of pediocin PA-1, lactococcin A, enterocin AS-48, nisin A and lacticin 481 producing strains. The probes were shown to be sensitive and specific for sequences belonging to the structural genes of the respective bacteriocins.

Bacteriocins↗
PubMed1998

Genetic analysis of microcin H47 immunity.

Microcin H47 is a bactericidal antibiotic produced by a natural Escherichia coli isolate. The genetic system encoding microcin production and immunity consists of at least seven clustered genes. Four of these are devoted to microcin biosynthesis and two genes are required for its secretion into the extracellular medium. The product of the seventh gene, mchI, determines the cell's self-immunity. This gene was shown to encode a highly hydrophobic 69-residue peptide. Analysis of the MchI amino acid sequence, as well as the characterization of MchI-PhoA hybrid proteins, indicated that the microcin immunity product is probably exported out of the cytoplasm and remains an integral membrane peptide. This localization of the immunity peptide points to the cellular membrane as the site of action of microcin H47.

Amino Acid Sequence↗
PubMed1998

[Cortical blindess as symptom of pre-eclampsia].

Neurological complications during preeclampsia are not infrequent; the appearance of total blindness is rare, however. We report the case of a 32-year-old primipara with no outstanding history, who presented total loss of vision with no accompanying neurological symptoms during week 37 of the pregnancy. Effective early management of blood pressure to levels at which self-regulation of cerebral perfusion could be established allowed total recovery of vision 8 hours after admission to the intensive care recovery ward. Cranial computerized axial tomography (CAT) showed bilateral occipital subcortical edema that resolved after 8 days. The patient was released 13 days after admission with no sequelae.

Adult↗
PubMed1998

[Chronic hemodialysis in children].

BACKGROUND: The final objective of every children that is admitted to a program o hemodialysis of peritoneodialysis is to receive a renal graft. AIM: To report the experience in pediatric hemodialysis in two pediatric hospitals in Chile that are reference centers for renal transplantation. PATIENTS AND METHODS: Sixty patients, 55% female, aged 2 to 15 years old, admitted to the dialysis and transplant program since 1987, with a creatinine clearance of less than 20 ml/min/1.73 m2, were studied. RESULTS: Twenty percent of children were less than 5 years old at the moment of admittance to the program and 3.3% weighed less that 10 kg. Etiologies of end stage renal disease were glomerulopathies in 33.4%, reflux nephropathy in 27.7%, obstructive uropathy in 13.3%, hypoplasia/dysplasia in 10%, hereditary problems in 8.3% and vascular disorders in 5%. Eighty six percent of patients were dialyzed less than 2 years and 5% more than 4 years. Fifty percent had received prior medical treatment, 5% had been treated with intermittent peritoneal dialysis, 5% with chronic ambulatory peritoneal dialysis and 20% presented as a terminal renal failure. Sixty two percent received a renal graft, 25% is still on hemodialysis, 3.3% switched to chronic ambulatory peritoneal dialysis, 3.3% had a recovery of renal function and 6.7% died being on hemodialysis. Arterio-venous fistulae were the vascular accesses in 75% of patients, double lumen catheters in 50% and vein grafts in 5%. Malfunctioning or infections were the main complications of arterio-venous fistulae, accounting for 30% of hospital admissions. CONCLUSIONS: The availability of new vascular accesses and new hemodialysis machines specially designed for children, along with specially trained health care personnel, should reduce the mortality and complication rates of hemodialysis in this age group.

Adolescent↗
PubMed1998

[Scales of risk assessment in coronary surgery and their usefulness].

Currently, there is an increasing interest in the fields of cardiology and cardiac surgery related to systems of risk assessment of cardiac surgery procedures. The main benefit of these systems is quality control of results obtained. Nevertheless, there are other interesting implications. Currently, most of the available scales make estimations of mortality risk with a defined operative technique, using preoperative variables. Other systems can make predictions on postoperative length of stay. Scales are built using the results of a large series, processed with different mathematical models. An important condition is the simplicity of use. There is a wide range of available systems originating from clinical experience in Europe and North-America. All of them include a common number of predictive factors, although the assigned weight can vary significantly. We recommend the routine use of these scales as a quality control system and as a method of characterization of our populations in order to make adequate comparisons among different groups.

Cardiac Surgical Procedures↗
PubMed1998

[Body mass index influence in the insulin action mechanisms].

OBJECTIVE: Improve the knowledge of the "in vitro" insulin action in healthy subjects with different body mass index (BMI), in order to know the role of obesity in the diabetes mellitus. MATERIAL: In 12 healthy subjects with different BMI and normal oral glucose test we made a gluteal biopsy to obtain adipose tissue. In the isolated adipocytes we studied the interaction of insulin with its receptor and the glucose transport. RESULTS: BMI was not correlated with the maximal specific 125I-insulin binding but was negative when correlated with the glucose transport in basal situation (r = -0.63, p < 0.05) as well as when stimulated with insulin (r = -0.67, p < 0.05), when the results were expressed as number of cells. When the data were expressed as surface, BMI was negative correlated with the percentage of maximal specific 125I-insulin binding (r = -0.81, p < 0.05), and also with the basal glucose transport (r = -0.69, p < 0.05) and stimulated with insulin (r = -0.77, p < 0.01). CONCLUSION: The increase of BMI is an important diabetogenic agent, acting at receptor as well as at postreceptor level, and the data should be expressed according to the cellular diameter rather than to the number of cells in subjects with different BMI. A cutting point was established at the 30 BMI level after which the described alterations could be observed.

Adult↗
PubMed1998

[Analysis of the changes observed in the sleep EEG recording of patients with juvenile myoclonic epilepsy].

OBJECTIVE: The initial phases and transitional periods of sleep facilitate electroclinical manifestations of juvenile myoclonic epilepsy (JME). The period at the time of waking is identified in the different phases of sleep by cyclic electrophysiological oscillations, which in turn are synchronous with the spike-and-wave or multiple spike-and-wave activity of the electric crises seen in JME and other epileptic syndromes. This observation supports the theory of an alternating cyclical pattern (ACP) as the trigger of these discharges. PATIENTS AND METHODS: Following classical macrostructural and microstructural patterns of EEG sleep analysis, we investigated electrophysiological behavior in 13 patients diagnosed as having JME, and 5 persons of homogeneous epidemiological characteristics as controls. RESULTS: In our study we observed that both groups had similar macrostructural sleep parameters. However, in patients prone to crises, these were concentrated in the first two hours recorded and showed no differences in sleep-waking transition or ACP of phase I sleep. These were significant when both periods were compared with the remaining NREM sleep. CONCLUSION: We conclude from this study that ACP is the microstructural element of sleep which modulates and permits classification of epileptiform anomalies, mainly in studies at the time of wakening.

Child↗
PubMed1998

[Usefulness of radiologic monitoring of epidural catheters using epidurography].

INTRODUCTION: Peridural analgesia involves a segmental block which at the thoracic level allows for early pulmonary recovery after chest or high abdominal surgery. The approach is difficult in children for reasons related to anatomy, maintenance, insertion of the catheter and dosing. OBJECTIVE: To report the radiologic monitoring of epidural catheter placement by epidurography as a technique for placing the epidural catheter in 17 patients for whom postoperative analgesia was to be provided by the same route. PATIENTS AND METHODS: Eighteen children (aged from 2 to 12) were given general anesthesia followed by epidural anesthesia. After catheterization of the epidural space, 1 or 1-5 ml of contrast was injected. Immediately afterwards an X-ray of the thoracic or lumbar spinal column, as appropriate to each case, was obtained. Epidural analgesia was provided with a mixture of bupivacaine 0.125% and fentanyl, in continuous perfusion or in fractionated doses. RESULTS: Placement of the catheter tip was confirmed in 17 cases by visualization of symmetry and the presence of contrast medium in the epidural space. In one case we observed extravasation of contrast medium, which had invaded the paravertebral space. The course was linear in 17 cases, with no looping. No complications related to injection of contrast medium were observed. CONCLUSIONS: Epidurography provides objective monitoring of tip placement and trajectory of epidural catheters, advantages which argue in favor of more frequent application of this imaging technique.

Adolescent↗
PubMed1997

Cervical lymph node metastases of medullary thyroid carcinoma: CT findings.

Medullary thyroid carcinoma (MTC) is a rare malignancy which spreads frequently to cervical lymph nodes. We report the CT findings of MTC metastatic cervical adenopathies in two patients with previously resected MTC. The CT scans showed calcifications (one patient) and massive homogeneous postcontrast nodal enhancement. Medullary thyroid carcinoma should be included in the differential diagnosis of entities showing calcifications and intense homogeneous adenopathic enhancement on CT studies.

Aged↗