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Biomedical subjects

J C Rodriguez

Publications and source records attributed to J C Rodriguez.

At least 19 recordsLinked to original sources
PubMed2006

Alterations in the gyrA and parC genes in Salmonella spp. following in vitro exposure to fluoroquinolones.

We characterize alterations in the QRDR fragment of gyrA and parC in Salmonella spp. following repeated exposure to different quinolones in two in vitro models. Mutations in QRDR of gyrA were found in only 25% of the mutants. The most frequent mutations were Asp87(R)Asn and Asp87(R)Tyr. Strains with the former mutation had a higher ciprofloxacin MIC than those with the latter. We did not find mutations in parC. Our data confirm that mutation in the QRDR fragment of gyrA is the mechanism that produces the greatest decrease in fluoroquinolone susceptibility. There is a greater reduction in the ciprofloxacin susceptibility of strains that were originally nalidixic acid-resistant than in that of strains that were originally susceptible, and this confirms that there is a greater likelihood of therapeutic failures with such strains.

Anti-Bacterial Agents↗
PubMed2001

Dynamic intraventricular obstruction in acute myocardial infarction.

Transient left ventricular dynamic obstruction (TLVO) is an infrequent complication in acute myocardial infarction (AMI). Its hallmark is a new systolic murmur associated with hemodynamic worsening. An echocardiogram is necessary for diagnosis. We report on two cases, both of which had a good outcome. Serial echocardiograms showed that enhanced contractility of the basal left ventricular segments obstructed cardiac ejection by means of mitral valve systolic anterior movement in the left ventricular outflow tract. In both cases, the intraventricular gradient remained for several days and subsequently disappeared. The understanding of this mechanism is useful for management of this clinical problem.

Diagnosis, Differential↗
PubMed2001

Incidence of tuberculosis and the importance of treatment of latent tuberculosis infection in a Spanish prison population.

OBJECTIVE: To establish the incidence of tuberculosis (TB) in a prison population and its link with latent tuberculosis infection treatment (LTIT). METHODS: From 1991 to 1999 a TB programme was run in a Spanish prison. A cohort study was conducted to know TB incidence and the associated variables. RESULTS: Of 1,050 people studied, 10% were co-infected by the human immunodeficiency virus (HIV) and Mycobacterium tuberculosis. Twenty-three cases of TB were detected, an incidence rate of 6.39 per 1,000 person-years of follow-up. Multivariate analysis showed HIV-infected patients (RR 4.07, 95%CI 2.61-6.35), and those infected by M. tuberculosis who did not undergo LTIT (RR 10.15, 95%CI 0.90-50.59) to be at greater risk of developing TB. In TST reactors, those co-infected with HIV (RR 10.15, 95%CI 3.80-27.07) and those who had not undergone LTIT (RR 8.53, 95%CI 1.12-64.86) were shown to be at the greatest risk of developing TB. CONCLUSIONS: The observed incidence of TB is much higher in prisons than in the community at large. HIV-M. tuberculosis co-infection appears as the main risk factor for developing TB, while LTIT significantly reduces incidence.

AIDS-Related Opportunistic Infections↗
PubMed2000

Craniofacial distraction osteogenesis en bloc.

Bone distraction of the superior and medial thirds of the craniofacial skeleton en bloc, avoiding a frontal craniectomy is presented. We applied this procedure in eight patients who were more than 5 years old with different types of craniofacial synostosis and who had not received previous treatment, and with a normal frontal shape. During monobloc advancement, major complications were encountered in older patients, especially the impossibility of the brain to expand rapidly to fill the retrofrontal dead space. Distraction osteogenesis of the craniofacial skeleton en bloc (without craniectomy) is feasible. Miniplates and screws are avoided as well as the possibility of frontal relapse or fractures of the frontozygomatic region. The patients did not need skull vault remodeling, except for a small cranioplasty at the bregma zone. The results obtained were satisfactory and stable at the time. This procedure avoids any kind of osteosynthesis, there is no extradural dead space, the operative time is brief, and blood loss is minimal. The inconvenience is the necessity of a second operation to remove the distractor.

Acrocephalosyndactylia↗
PubMed2000

Comparison of two antibiotic regimens in the treatment of perforated appendicitis in pediatric patients.

BACKGROUND AND PURPOSE: An increased incidence of post-surgical infectious complications in children admitted with a diagnosis of perforated appendicitis led to development of a disease-specific antibiogram and modification of our post-operative antibiotic regimen. METHODS: A historical control group comprised of 32 pediatric patients receiving ampicillin, gentamicin, and clindamycin (group AGC) was compared to a cohort of 32 children receiving ticarcillin/clavulanate plus gentamicin (group TG). The surgical procedure, peri-operative management, and inclusion, exclusion and discharge criteria were the same for each group. Outcome measures including length of stay, time to defervesce, incidence of infectious complications, and clinical failures to the antibiotic regimen were compared. RESULTS: The groups were similar with respect to gender, age, weight, surgical time, pre-operative leukocytes, and number of intra-operative bacterial isolates cultured per patient. Length of stay was 10.1 days in group TG and 12.5 days for group AGC (p = 0.0197). The number of clinical failures was reduced from 9 (28.1%) to 2 (6.3%) in group TG (p = 0.02). The time to defervesce was decreased by 1.4 days, and the number of infectious complications was reduced to 2.5-fold in group TG patients. CONCLUSIONS: Ticarcillin/clavulanate plus gentamicin was clinically more effective than ampicillin, gentamicin, and clindamycin combination therapy in the management of perforated appendicitis in our pediatric population.

Adolescent↗
PubMed1999

Legal, ethical, and professional issues to consider when communicating via the Internet: a suggested response model and policy.

Providing nutrition information via the Internet enables dietetics professionals to expand their practices, markets, and networks, but also presents new legal, ethical, and professional issues. Based on her experiences responding to unsolicited questions through a Spanish-language nutrition Web site, this author presents issues related to electronic communication, a process for formulating responses, and makes suggestions for a policy. The issues include the global nature of cyberspace; cultural variations in Spanish-language food terms and models, credentialing, licensure, and scope of practice; presentation of credentials; the inquirer's knowledge and information sources; the nature of the cyberspace relationship; and protection of the client and the professional. These issues have created a need for an electronic communication policy and some components of such a policy are identified, including the nature of electronic nutrition, distinguishing between public and client-specific communication, question-and-answer formats, opening and closing caveats, and recording processes.

Computer Simulation↗
PubMed1999

Limiting cefotaxime pediatric dosing to adult standards: a pharmacokinetic simulation study.

OBJECTIVE: The recommended cefotaxime dose of 50 mg/kg every six to eight hours for pediatric patients with a body weight greater than 20 kg exceeds the standard 1-gram dose recommended for adult patients. This study estimated whether limiting the cefotaxime dose recommended for children with mild to moderate infections to a standard 1-gram dose would achieve serum concentrations and time above the MIC90 comparable to those in adults. METHODS: Serum concentration profiles were simulated from mean cefotaxime pharmacokinetic parameters that have been published for children and for adults using widely available spreadsheet software. The simulations employed an open, one-compartment, multiple-dose model and were calculated using a common commercial spreadsheet. The model was used to predict serum concentrations using dosage regimens of 1 g or 50 mg/kg administered every six or eight hours in pediatric patients of various weights with pediatric pharmacokinetic parameters and 1 g every six or eight hours for adult patients with adult pharmacokinetic parameters. The time that cefotaxime concentrations exceeded the MIC90 for pediatric pathogens was also calculated. RESULTS: The 50 mg/kg pediatric dosing regimens administered every 8 hours (q8h) or every 6 hours (q6h) consistently produced peak serum concentrations and area under the concentration versus time curve (AUC) values higher than those in adults. Serum concentrations and AUCs generated for the 1-gram regimens for various pediatric weight categories were also above those predicted in adults. The time above the MIC90 for pediatric patients was equivalent to or exceeded those of the adult simulations for all pathogens. CONCLUSIONS: The results support the concept of limiting cefotaxime dosage regimens to 1 g administered every 6 or 8 hours for mild to moderate infections in children weighing more than 20 kg. This dosage regimen could lead to dose standardization procedures, which could produce reductions in drug costs associated with individualized dosage preparation.

Adult↗
PubMed1997

Effect of intravascular irradiation on cell proliferation, apoptosis, and vascular remodeling after balloon overstretch injury of porcine coronary arteries.

BACKGROUND: Ionizing radiation has been shown to reduce vascular lesion formation after balloon overstretch injury of pig coronary arteries. The present series of experiments examines the mechanism by which this occurs. METHODS AND RESULTS: Balloon injury was performed on porcine coronary arteries, followed immediately by ionizing radiation using either a source train of 90Sr/Y or 192Ir seeds designed to deliver 14 or 28 Gy at a depth of 2 mm from the source. The animals were killed 3, 7, or 14 days after injury. Bromodeoxyuridine was administered 24 hours before euthanasia to label proliferating cells. Cell proliferation was significantly reduced on day 3 in the adventitia and media of the irradiated vessels compared with controls. Two weeks after injury, there were fewer alpha-actin-positive myofibroblasts in the adventitia of the irradiated vessels than in nonirradiated controls, and morphometric analysis indicated that the vessel perimeter of the irradiated vessels was significantly larger than in controls. Together, these results suggest a positive effect of intravascular irradiation on vascular remodeling. Apoptosis was estimated by terminal transferase dUTP-biotin nick-end labeling (TUNEL) 3 and 7 days after injury. TUNEL-labeled cells were found primarily in the adventitia at the medial tear, but no differences were detected between irradiated and control vessels. CONCLUSIONS: These studies suggest that intracoronary radiation primarily inhibits the first wave of cell proliferation in the vessel wall and demonstrates a favorable effect on late remodeling by preventing adventitial fibrosis at the injury site.

Actins↗
PubMed1997

Factors affecting mortality of crossbred and exotic chickens kept under backyard systems in Yucatan, Mexico.

Chicken mortality was studied in 24 randomly selected smallholder flocks in one village in Yucatan, Mexico between July and December 1993. Each family received a package of 10 to 12 chicks of 3 weeks of age. Approximately half of the chicks were purebred and the remainder were crosses produced by mating exotic with local breeds. All smallholders were visited twice a week. Feeding and management (except vaccination and medication) were left to smallholders. Data were processed by Chi-square, Mantel-Haenzel test and survival analysis. Before reaching 140 days of age 43.2% of the birds died. The highest mortality was observed during the 113 to 140 days of age period and the lowest was in the period between 22 and 56 days of age. Of all birds, 10.5% died from coccidiosis and 7.6% from Marek's disease. Of the risk factors investigated only medication and genotype showed significant effects on mortality. The effect of genotype was significant up to 112 days of age (P < 0.05). Crossbred birds lived longer than purebred; independently, medicated birds lived longer than non-medicated birds.

Animal Husbandry↗
PubMed1996

Obstructive sialadenitis caused by intraparotid deposits of gold salts: a case report.

A case of obstructive sialadenitis caused by deposits of gold salt compound in the intraparotid lymphoid tissues in a woman with classic rheumatoid arthritis is presented. The patient had been treated with a parenteral gold salt compound (sodium aurothiomalate) for 10 years with chrysotherapy balance of 7525 mg. She presented with swelling of both parotid glands on eating, and computed tomography images showed accumulation of high density spots. Obstructive sialadenitis most probably was caused by local compression on the excretory ducts of the parotids. This clinical disorder should be classified as a case of mechanical, nontumoral, obstructive sialadenitis caused by gold salt compound.

Adult↗
PubMed1996

Nutritional status of CAPD patients at three years.

A nutritional assessment was carried out in 63 patients starting treatment from April 1990 up to December 1993. Anthropometric measurements were performed showing a prevalence of protein-calorie malnutrition (PCM) of 21% in a total of 142 clinical surveys carried out in the above-mentioned sample. A steady state of albumin levels in plasma was verified during a three-year follow-up period at a lower level than that of the control group. The patients' lymphocytic profile throughout the study was characterized by lymphopenia and decreased B and T8 lymphocytes. During the first two years of continuous ambulatory peritoneal dialysis (CAPD), a high percentage of patients met the "adequacy" dialysis criteria as residual renal function plays an important role as regards treatment.

Adult↗
PubMed1995

Do changes in dietary salt influence blood pressure of hypertensive patients pharmacologically controlled with verapamil? The Salt-Switching-Study (SSS).

To study how changes in dietary salt influence the blood pressure (BP) of pharmacologically controlled hypertensive patients, we have selected from a large multicenter trial two subgroups of 14 and 16 patients who attained BP control (office DBP < 90 mm Hg) after a 4-week treatment with verapamil SR 240 mg once daily, either under an unrestricted salt diet (high-salt; 14 patients) or under a moderately restricted salt diet (low-salt; 16 patients). All of them were switched to the opposite dietary salt regimen and continued on verapamil for 4 more weeks (Salt-Switching-Period). Office BP and ambulatory blood pressure monitoring (ABPM) were registered before and after the Salt-Switching-Period. Salt intake was checked by urinary sodium excretion (UNa). Patients switching from high- to low-salt reduced UNa from 180.9 +/- 22.9 to 89 +/- 28 mM Na/24h (P < 0.001) and patients switching from low- to high-salt increased UNa from 85 +/- 38.4 to 175.8 +/- 57.5 mM Na/24h (P < 0.001). No significant changes in BP were found by ABPM either in the group switching from high- to low-salt or in the group switching from low- to high-salt. In the latter group, a significant increase was observed in office DPB but not in SBP. Short-term changes in salt intake seem to have little influence on the BP of patients pharmacologically controlled with verapamil.

Adult↗
PubMed1992

Downregulation of hepatic albumin mRNA in response to induced hypercholesterolemia in rabbits.

Albumin gene expression was studied in rabbits fed on a cholesterol-rich diet for up to 16 weeks. Livers from experimental animals showed extensive lipid deposition. Hepatic albumin mRNA abundance decreased along the treatment to very low levels after 16 weeks. An 8-fold decrease in the rate of transcription of this gene was also detected. This downregulation of albumin gene expression cannot be attributed to a general impairment of RNA synthesis, as expression of other liver-specific and housekeeping genes did not vary significantly. There was a decrease in ascitic fluid albumin levels after 10 weeks, although serum albumin levels remained unchanged throughout the treatment. Our results are discussed in view of the relationship of albumin levels with hypercholesterolemia.

Animals↗
PubMed1992

Foam cells from aorta and spleen overexpress apolipoprotein E in the absence of hypercholesterolemia.

We have studied Apo E expression in atherosclerotic lesions and spleens in rabbits after a cholesterol-rich diet is discontinued and plasma cholesterol levels return to normal values. After 16 weeks, foam cells are still present in the atherosclerotic lesions and Apo E expression persists restricted solely to the lesion as ascertained by in situ RNA hybridization and northern blot. Apo E expression is induced in spleens of hypercholesterolemic rabbits. However Apo E mRNA levels decrease in this organ parallel to the disappearance of lipid loaded macrophages. These results of in vivo studies indicate that Apo E overexpression in foam cells does not depend on high serum cholesterol levels, but is a characteristic of macrophages that have acquired the foam cell phenotype.

Animals↗