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Biomedical subjects

P Rodriguez

Publications and source records attributed to P Rodriguez.

At least 37 records · Page 2Linked to original sources
PubMed2000

Carbon monoxide stability in stored postmortem blood samples.

Carbon monoxide (CO) poisoning remains a common cause of both suicidal and accidental deaths in the United States. As a consequence, determination of the percent carboxyhemoglobin (%COHb) level in postmortem blood is a common analysis performed in toxicology laboratories. The blood specimens analyzed are generally preserved with either EDTA or sodium fluoride. Potentially problematic scenarios that may arise in conjunction with CO analysis are a first analysis or a reanalysis requested months or years after the initial toxicology testing is completed; both raise the issue of the stability of carboxyhemoglobin in stored postmortem blood specimens. A study was conducted at the Bexar County Medical Examiner's Office to evaluate the stability of CO in blood samples collected in red-, gray-, and purple-top tubes by comparing results obtained at the time of the autopsy and after two years of storage at 3 degrees C using either an IL 282 or 682 CO-Oximeter. The results from this study suggest that carboxyhemoglobin is stable in blood specimens collected in vacutainer tubes, with or without preservative, and stored refrigerated for up to two years.

Carbon Monoxide↗
PubMed2000

Maternal Trypanosoma cruzi infection upregulates capacity of uninfected neonate cells To produce pro- and anti-inflammatory cytokines.

The possibility of maternal in utero modulation of the innate and/or adaptive immune responses of uninfected newborns from Trypanosoma cruzi-infected mothers was investigated by studying the capacity of their whole blood cells to produce cytokines in response to T. cruzi lysate or lipopolysaccharide-plus-phytohemagglutinin (LPS-PHA) stimulation. Cells of such newborns occasionally released gamma interferon (IFN-gamma) and no interleukin-2 (IL-2) and IL-4 upon specific stimulation, while their mothers responded by the production of IFN-gamma, IL-2, and IL-4. Infection in mothers was also associated with a hyperactivation of maternal cells and also, strikingly, of cells of their uninfected neonates, since their release of proinflammatory (IL-1beta, IL-6, and tumor necrosis factor alpha [TNF-alpha]) as well as of anti-inflammatory (IL-10 and soluble TNF receptor) cytokines or factors was upregulated in the presence of LPS-PHA and/or parasite lysate. These results show that T. cruzi infection in mothers induces profound perturbations in the cytokine response of their uninfected neonates. Such maternal influence on neonatal innate immunity might contribute to limit the occurrence and severity of congenital infection.

Chagas Disease↗
PubMed1999

Conventional respiratory viruses recovered from immunocompromised patients: clinical considerations.

Lower respiratory tract infection is the most common complication in the immunocompromised patient. From January 1991 to December 1995, 785 consecutive patients with suspected respiratory tract infections were studied. One hundred ninety-nine viruses were isolated from 182 (23%) of 785 bronchoalveolar lavage fluid specimens. Cytomegalovirus was isolated from 131 patients, herpes simplex virus was recovered from 31, and conventional respiratory viruses (CRVs) were recovered from 36. There were 9 influenza A viruses, 2 influenza B viruses, 7 parainfluenza viruses, 5 respiratory syncytial viruses, 5 adenoviruses, 6 enteroviruses, and 3 rhinoviruses. We identified 22 patients from whom a CRV was the only microorganism recovered; 13 patients developed pneumonia, 10 had acute respiratory failure, 5 required support with mechanical ventilation, and 5 (23%) died. In conclusion, CRVs are frequent causes of respiratory illnesses and are associated with high rates of morbidity and mortality among immunocompromised patients.

Adenoviridae↗
PubMed1999

Fluvoxamine distribution in postmortem cases.

Four postmortem cases are reported in which the selective serotonin re-uptake inhibitor fluvoxamine was identified. Fluvoxamine was detectable using a standard alkaline drug screen, chromatographed well using a HP-1 column, and did not require derivitization for quantitation. Two of the cases reported were drug intoxications; fluvoxamine was only an incidental finding in the other 2 cases. Central and peripheral blood values are reported, as well as antemortem blood, bile, vitreous fluid, and urine values. No solid organs were obtained in any of the cases. Quantitations were performed using both an analytical standard and a fluvoxamine tablet for the preparation of calibrators. A comparison of quantitative values was made to evaluate the feasibility of using a tablet as the drug source for the preparation of calibrators when a pure reference material is unavailable. Postmortem peripheral blood concentrations ranged from approximately 0.5 mg/L in a case of suicidal shooting to approximately 6 mg/L in a case of drug overdose. Evidence of postmortem redistribution was noted in the only case for which both central and peripheral blood were obtained. Quantitations using an extracted drug tablet for the preparation of calibrators correlated well with quantitations using a pure reference material.

Adult↗
PubMed1999

Needs and supports reported by Latino families of young children with developmental disabilities.

We interviewed 200 Latino parents (50 Mexican couples, 50 Puerto Rican couples) living in the United States to determine needs and supports related to raising a child with a disability and to identify variables related to reported needs and supports. The pattern of needs expressed was similar to that found in previous studies, but the number was substantially higher. More support was reported from family and formal sources than from friends or informal sources. Using repeated measures of analysis of covariance involving six family variables and three child variables, we found that English language proficiency was the only variable to account for significant variance in needs and supports.

Acculturation↗
PubMed1998

Protective effects of cyclopiazonic acid on ischemia-reperfusion injury in rabbit hearts.

The cardioprotective effects on myocardial ischemia of the sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) inhibitor, cyclopiazonic acid (CPA), were studied. We used the isolated arterially perfused interventricular septum of the rabbit heart submitted to 30-min global ischemia/30-min reperfusion. Mechanical [maximal increase in resting tension (MIRT), and the recovery of developed tension (RDT)], and biochemical parameters [creatine phosphokinase activity (CPK) in the effluent] were analyzed. CPA, 1 microM, perfused 30 min before the ischemia intervention significantly increased RDT by 54% and lessened MIRT by 66%. CPA also decreased CPK in the perfusate by 67.7 and 71.4% at 0-2 and 5-7 min of reperfusion, respectively. No additional benefits were shown either when the drug was perfused, both during ischemia and reperfusion, or with higher CPA concentrations (10-30 microM). The CPA cardioprotection was lost when the drug was present only during the reperfusion period. CPA exhibits functional and biochemical cardioprotective effects on myocardial ischemia. We postulated a decreased SR calcium contribution to the initial cytoplasmic calcium overload as the most probable mechanism involved.

Animals↗
PubMed1998

Two marine Agrobacterium producers of sesbanimide antibiotics.

Sesbanimides are cytotoxic compounds, originally isolated in 1983 from seeds of the leguminous plants Sesbania drummondii and Sesbania punicea. In this paper we describe the bacterial production of sesbanimides by two "marine Agrobacterium"; strain PH-103 which produces Sesbanimide-A and strain PH-A034C which produces Sesbanimide-C. The isolation and taxonomy of the producing microorganisms, fermentation and isolation of sesbanimides are reported.

Alkaloids↗
PubMed1997

Functional characterization of human nucleosome assembly protein-2 (NAP1L4) suggests a role as a histone chaperone.

Histones are thought to play a key role in regulating gene expression at the level of DNA packaging. Recent evidence suggests that transcriptional activation requires competition of transcription factors with histones for binding to regulatory regions and that there may be several mechanisms by which this is achieved. We have characterized a human nucleosome assembly protein, NAP-2, previously identified by positional cloning at 11p15.5, a region implicated in several disease processes including Wilms tumor (WT) etiology. The deduced amino acid sequence of NAP-2 indicates that it encodes a protein with a potential nuclear localization motif and two clusters of highly acidic residues. Functional analysis of recombinant NAP-2 protein purified from Escherichia coli demonstrates that this protein can interact with both core and linker histones. We demonstrate that recombinant NAP-2 can transfer histones onto naked DNA templates. Deletion mutagenesis of NAP-2 demonstrates that both NH3- and COOH-terminal domains are required for histone transfer activity. Subcellular localization studies of NAP-2 indicate that it can shuttle between the cytoplasm and the nucleus, suggesting a role as a histone chaperone. Given the potential role of the human NAP-2 gene (HGMW-approved symbol NAP1L4) in WT etiology, we have elucidated the exon/intron structure of this gene and have analyzed the mutational status of NAP-2 in sporadic WTs. Our results, coupled with tumor suppression assays in G401 WT cells, do not support a role for NAP-2 in the etiology of WT. A putative role for NAP-2 in regulating cellular differentiation is discussed.

Amino Acid Sequence↗
PubMed1997

Clinical and angiographic implications of coronary stenting in thrombus-containing lesions.

OBJECTIVES: This study sought to determine the results of coronary stenting in thrombus-laden lesions. BACKGROUND: The angiographic evidence of intracoronary thrombus has classically been considered a formal contraindication to stent implantation. However, with increasing use of stenting, the indications for this technique have widened to include treatment of patients who have an acute coronary syndrome or lesions with adverse anatomic features. METHODS: We studied 86 consecutive patients (mean age +/- SD 61 +/- 11 years, 14 women) undergoing coronary stenting of a thrombus-containing lesion; the procedure was performed electively in 39% and after angioplasty failure in 61%. Sixty-four patients (75%) were treated for unstable angina, and 19 (22%) underwent the procedure during an acute myocardial infarction. A specific protocol that included clinical and late angiographic follow-up was used. RESULTS: Angiographic success was obtained in 83 patients (96%). Five patients (6%) died during the hospital stay despite angiographic success; four of these had cardiogenic shock, and one (1%) had subacute stent thrombosis. Non-Q wave myocardial infarction developed in five additional patients (6%), and four of these five had data consistent with distal embolization. Of the 78 patients discharged with angiographic success, 67 (86%) were event-free and clinically improved at last follow-up visit (12 +/- 11 months). During the follow-up period, eight patients required repeat angioplasty, one patient required heart transplantation, and two patients died. Quantitative angiography demonstrated excellent angiographic results after stenting (minimal lumen diameter 0.31 +/- 0.4 vs. 2.77 +/- 0.6 mm). Late angiographic follow-up (5.5 +/- 1 months) was obtained in 50 patients with 54 lesions (93% of eligible), revealing a minimal lumen diameter of 2.0 +/- 1 mm and restenosis (lumen narrowing > 50%) in 18 lesions (33%). CONCLUSIONS: Coronary stenting constitutes an effective therapeutic strategy for patients with thrombus-containing lesions, either after failure of initial angioplasty or electively as the primary procedure. Coronary stenting in this adverse anatomic setting results in a high degree of angiographic success, a low incidence of subacute thrombosis and an acceptable restenosis rate.

Adult↗
PubMed1997

Feasibility of intravascular ultrasound studies: predictors of imaging success before coronary interventions.

BACKGROUND: Intravascular ultrasound (IVUS) is currently used to study lesions during transcatheter coronary therapy. However, before dilation some lesions cannot be reached or crossed with the imaging catheter. HYPOTHESIS: This study seeks to elucidate which factors determine the feasibility of IVUS examination before coronary interventions. METHODS: Accordingly, 100 consecutive patients undergoing IVUS examination before coronary angioplasty were prospectively studied. The clinical and angiographic characteristics of 77 patients with a successful IVUS study (Group A) were compared with those of 23 patients in whom IVUS was attempted but the target lesion could not be interrogated (Group B). The echogenic characteristics of the target lesion [before (n = 77) or after intervention (in 18 patients in Group B)] were also studied. RESULTS: Patients in Group B were significantly older (62 +/- 7 vs. 57 +/- 10 years, p < 0.05) and more frequently had stable angina [8 (35%) vs. 9 (11%), p < 0.05]. The distribution of lesions within the coronary tree and angiographic lesion characteristics including length, eccentricity, calcification, bend location, and the American College of Cardiology/American Heart Association classification were similar in both groups. However, proximal tortuosities (> 45 degrees at end diastole) were more frequently found in Group B [20 (87%) vs. 47 (61%), p < 0.05]. In addition, by quantitative angiography, patients in Group B had smaller arteries (reference diameter 2.8 +/- 0.4 vs. 3.1 +/- 0.4 mm, p < 0.05) and more severe lesions (minimal lumen diameter 0.46 +/- 0.24 vs. 0.65 +/- 0.34 mm, p < 0.05). On IVUS, calcified lesions were more frequently visualized in Group B (61 vs. 38%, p < 0.05). On multivariate analysis, catheter size, baseline minimal lumen diameter, angiographic proximal tortuosities, and lesion calcification on imaging were independent predictors of the feasibility of IVUS studies. CONCLUSIONS: Unsuccessful IVUS studies before intervention occur more frequently (1) in vessels with proximal tortuosities or severe lumen narrowing, (2) in lesions that are calcified on IVUS, and (3) when large imaging catheters are used.

Angina Pectoris↗
PubMed1997

Brazil: model life tables and stable population.

"In the 1974 Meeting of the Brazilian Association for Population Studies, Frias and Leite presented a set of model life tables that were meant to reflect the sex-age structure of Brazilian mortality. A later examination of this study revealed the need for revision and further development in order to improve this valid piece of work." The present article reviews and complements the earlier study.

Age Distribution↗