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Biomedical subjects

A Rodriguez

Publications and source records attributed to A Rodriguez.

At least 55 records · Page 3Linked to original sources
PubMed2002

Prognostic significance of the mode of detection in renal tumours.

OBJECTIVE: To evaluate the mode of detection of 400 renal tumours as a prognostic factor compared with the usual clinical and pathological prognostic variables. PATIENTS AND METHODS: The data were reviewed for 400 patients operated for a renal tumour at our institution between 1984 and 1999, analysing the prognostic value of age, sex, tumour size, stage, grade, vein invasion, adrenal gland invasion, lymph node invasion, metastasis, and mode of detection (incidental or not). The survival rates were assessed using the Kaplan-Meier method and log-rank test, and the data evaluated using multivariate analysis with the Cox proportional-hazard model. RESULTS: In all, 151 (38%) renal tumours were discovered incidentally. There was no significant difference in the percentage of renal cell carcinoma found between the groups of patients discovered incidentally or not (94.4% vs 93.9%). Tumours were smaller in the incidental group (5.7 cm vs 8.7 cm, P < 0.001). In the incidental group, 15.2% of the tumours were treated with partial nephrectomy, against 1.2% in the symptomatic group (P < 0.001). The specific survival was significantly better in patients with renal tumours discovered incidentally (log-rank test, P < 0.001). The multivariate analysis showed that the mode of detection, stage, grade, metastasis (all P < 0.001), and lymphatic extension (P = 0.005) were independent prognostic factors. CONCLUSION: The incidental discovery of renal tumours gives a supplementary benefit to patients in terms of survival, and should be considered as a prognostic factor in addition to stage and grade.

Carcinoma, Renal Cell↗
PubMed2002

Development of thrombocytosis in HIV+ drug users: impact of antiretroviral therapy.

With the exception of hemolytic anemia, the potential hematological toxicity of antiretrovirals (ARV) and combination treatments in HIV treated individuals has not been well established. We report, for the first time, hematological toxicity defined as thrombocytosis in 9% of the HIV+ patients receiving highly active antiretroviral treatment (HAART) being followed in a nutritional clinical trial. Participants were evaluated every 6 months during a 2-year period (1998-2000) and blood drawn for biochemical, hematological and immunological parameters. NK cells were negatively correlated with platelet counts in the total cohort (P = 0.018) and persistently elevated with ARVT. Chronic thrombocytosis was associated with significantly lower NK percentages (P = 0.005). Twenty-five percent of the patients with thrombocytosis developed a cardiovascular disease. Together, these results support the proposal that HAART may increase the risk of hematological dysfunction and impact the risk of cardiovascular disease.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Intrinsic changes on automatism, conduction, and refractoriness by exercise in isolated rabbit heart.

We have studied the intrinsic modifications on myocardial automatism, conduction, and refractoriness produced by chronic exercise. Experiments were performed on isolated rabbit hearts. Trained animals were submitted to exercise on a treadmill. The parameters investigated were 1) R-R interval, noncorrected and corrected sinus node recovery time (SNRT) as automatism index; 2) sinoatrial conduction time; 3) Wenckebach cycle length (WCL) and retrograde WCL, as atrioventricular (A-V) and ventriculoatrial conduction index; and 4) effective and functional refractory periods of left ventricle, A-V node, and ventriculoatrial retrograde conduction system. Measurements were also performed on coronary flow, weight of the hearts, and thiobarbituric acid reagent substances and glutathione in myocardium, quadriceps femoris muscle, liver, and kidney, to analyze whether these substances related to oxidative stress were modified by training. The following parameters were larger (P < 0.05) in trained vs. untrained animals: R-R interval (365 +/- 49 vs. 286 +/- 60 ms), WCL (177 +/- 20 vs. 146 +/- 32 ms), and functional refractory period of the left ventricle (172 +/- 27 vs. 141 +/- 5 ms). Corrected SNRT was not different between groups despite the larger noncorrected SNRT obtained in trained animals. Thus training depresses sinus chronotropism, A-V nodal conduction, and increases ventricular refractoriness by intrinsic mechanisms, which do not involve changes in myocardial mass and/or coronary flow.

Animals↗
PubMed2002

Vitamins and mineral intake in elderly people from Extremadura.

To evaluate the vitamin and mineral consumption of a group of elderly people of the Comunidad of Extremadura. 122 subjects 62.5+/-5.3 years (64 women, 57 men) responded to a survey on their food intake the day before. The vitamin and mineral intake was calculated using a computer program from the University of Granada. We found no statistically significant differences by gender in the intake of the following vitamins: niacin (24.5+/-10.1 vs 25.6+/-9.7 mg/day), B1 (1.6+/-0.6 vs 1.7+/-0.6 mg/day), B6 (1.7+/-0.6 vs 1.8+/-0.5 mg/day), C (129.5+/-82.1 vs 158.1+/-97.6 mg/day), D (4.4+/-7.5 vs 3.8+/-6.5 microg/day), E (7.8+/-4.1 vs 8.1+/-3.8v mg/day), and folic acid (326.6+/-164.0 vs 383.1+/-215.3 microg/day). We did find statistically significant differences in the intake of the vitamins: A (582.2+/-299.6 vs 771.8+/-602.2 microg/day, p<0.05), B12 (23.4+/-20.3 vs 13.1+/-12.1 microg/day, p<0.001) and B2 (1.6+/-0.4 vs 1.8+/-0.5 mg/day, p<0.05). With respect to mineral intake, we found no statistically significant differences by gender in the intake of the following minerals: calcium (1046.8+/-276.9 vs 1088.9+/-307.7 mg/day), iron (20.2+/-6.6 vs 18.5+/-8.6 mg/day), iodine (73.6+/-37.9 vs 73.8+/-41.1 mg/day), potassium (2804.6+/-1088 vs 2837.5+/-1035.8 mg/day), magnesium (405.4+/-155.3 vs 366.5+/-141.3 mg/day), phosphorus (1407.4+/-408.6 vs 1317.2+/-447.2 mg/day) and zinc (8.9+/-3.3 vs 8.0+/-2.7 mg/day). We found a statistically significant difference (p<0.05) for sodium (2124.9+/-1049.5 mg/day in men and 1728.4+/-992.5 mg/day in women). Our results showed an intake less than the RDA of vit.A, while the vit.B12 intake was greater than the RDA. The intake of the other parameters fitted the recommended values.

Aged↗
PubMed2002

[Effects of the alveolar recruitment manoeuver and PEEP on arterial oxygenation in anesthetized obese patients].

BACKGROUND: Diminished functional residual capacity and pulmonary collapse during general anesthesia lead to alterations in respiratory mechanics and gas exchange. Such phenomena are more pronounced in obese patients. We recently demonstrated the beneficial effects of the alveolar recruitment strategy on oxygenation in anesthetized patients of normal body mass index (BMI). The aim of the present study was to evaluate whether obese patients also benefit from the alveolar recruitment strategy and to determine the level of positive end-expiratory pressure (PEEP) that prevents recollapse in obese patients. METHODS: Three groups of 30 patients each were studied: patients with normal BMI (control group) and obese patients to whom we applied PEEP at 5 and 10 cm H2O (obese-5 and obese-10 groups, respectively) after the recruitment maneuver. We studied respiratory mechanics (respiratory distensibility, airway pressures and flow volume) and arterial oxygenation (PaO2) before and after the recruitment. RESULTS: PaO2 at baseline was higher in the control group (174 +/- 44 mm Hg) than in either the obese-5 or obese-10 group (108 +/- 24 and 114 +/- 22 mm Hg, respectively, p < 0.001). Oxygenation improved in all groups after recruitment (p < 0.001), and PaO2 in the obese-10 group was similar to that of the control group (218 +/- 25 mm Hg and 259 +/- 80 mm Hg, respectively, p > 0.05). Oxygenation in the obese-5 group, however, was worse (153 +/- 41 mm Hg) than that of either of the other groups (p < 0.001). CONCLUSIONS: We conclude that the alveolar recruitment strategy was effective for increasing PaO2 in anesthetized patients, regardless of body mass. The oxygenation of obese patients receiving the higher level of PEEP was similar to that of non-obese patients.

Aged↗
PubMed2001

Human Raphe Magnus Nucleus: a morphometric Golgi-Cox study with emphasis on sex differences.

The number and proportion of neurons according to their type and size in the Raphe Magnus Nucleus stained by the Golgi-Cox and Nissl methods were compared in male and female infants. Four female/male pairs aged from 2 to 150 days were studied. While females showed more neurons than males, males showed a higher proportion of large multipolar (more than 40 microm) and fusiform neurons (more than 20 microm) but not of ovoid neurons (more than 15 microm). These differences varied according to the type of cells and age of infants. Some of these results are similar to those found in the human Median Raphe Nucleus with the same methods.

Cell Count↗
PubMed2001

Allograft rejection predicts the occurrence of late-onset cytomegalovirus (CMV) disease among CMV-mismatched solid organ transplant patients receiving prophylaxis with oral ganciclovir.

The natural history of cytomegalovirus (CMV) disease associated with solid organ transplantation has been modified as a result of the widespread use of antiviral prophylaxis. Anecdotal reports have indicated a reduction of CMV disease at the expense of its later occurrence after completion of ganciclovir prophylaxis. The present study investigated the occurrence of CMV disease and its risk factors among 37 liver and kidney transplant recipients with CMV D+/R- status who received oral ganciclovir during the first 100 days posttransplantation. CMV disease occurred in 9 patients (24.3%) at a median of 144 days posttransplantation (range, 95-190 days). Allograft rejection was found to be strongly associated with the occurrence of late-onset CMV disease (risk ratio, 6.6; 95% confidence interval, 1.4-32.1; P=.02). Thus, CMV D+/R- solid organ transplant recipients receiving 3 months of oral ganciclovir who develop allograft rejection during the period of antiviral prophylaxis may benefit from extended and/or enhanced antiviral prophylaxis to prevent late-onset CMV disease.

Administration, Oral↗
PubMed2001

Role of c-myc regulation in Zta-mediated induction of the cyclin-dependent kinase inhibitors p21 and p27 and cell growth arrest.

Latency-associated Epstein-Barr virus (EBV) gene expression induces cell proliferation. Unlike the latency associated genes, lytic gene expression in EBV, as well as other herpesviruses, elicits cell cycle arrest. Previous studies have shown that the EBV immediate early lytic transactivator, Zta, induces a G(0)/G(1) cell cycle arrest through induction of the cyclin-dependent kinase inhibitors, p21 and p27. Here we show that while EBV latency is intimately linked to activation of the protooncogene, c-myc, Zta represses c-myc expression. We also show that inhibition of c-myc expression is required for Zta-mediated growth arrest and for maximal induction of p21 and p27. Nevertheless, induction of p21 and p27 is also influenced by a c-myc-independent mechanism. A detailed genetic analysis of Zta's basic/DNA binding region identified two distinct subregions that contribute to full induction of p21 and p27. One subdomain influences p21 and p27 expression through the c-myc-dependent mechanism and the other subdomain influences p21 and p27 induction through the c-myc-independent pathway. Together, these studies further our understanding of the complex nature of Zta-induced growth arrest.

Amino Acid Sequence↗
PubMed2001

[A prospective randomized study of wound drainage versus non-drainage in primary total hip or knee arthroplasty].

PURPOSE OF THE STUDY: Drainage of the operative wound following total hip or knee replacement (THR, TKR) is usually performed to avoid hematoma formation. A certain amount of blood is lost through the drain. The necessity of wound drainage has been questioned, with a view towards blood saving, although most surgeons have not abandoned drainage for fear of local complications. A prospective randomized study was undertaken to compare drainage and non-drainage following THR/TKR in terms of blood-saving and local complications. MATERIAL AND METHODS: A total of 256 patients undergoing primary THR (152) or TKR (104) were randomly allocated to undergo either suction drainage or no drainage of the wound: there were 76 drained and 76 non-drained THR's, 52 drained and 52 non-drained TKR's. Blood loss was calculated in each patient from the postoperative drop in hematocrit values; the amounts of blood lost intra-operatively and in the drain were also recorded, as was the number of blood units transfused in each patient. Swelling, hip or knee range of motion and wound healing were monitored over the first 6 weeks after operation, and any local or systemic complication was recorded. RESULTS: No significant difference was noted between drained and non-drained THR's/TKR's regarding swelling, recovery of hip or knee motion, wound healing, other local or systemic complications. Following THR, no significant difference was noted between calculated blood losses or transfusion requirements in drained versus non-drained patients. Patients with drains lost on average 1 942 ml of blood versus 1 766 ml for non-drained patients; they received on average 1.18 units of transfused blood versus 1.32 units for patients without drains. The differences are not significant. Following TKR, total blood loss was significantly higher in non-drained than in drained patients (1 983 ml versus 1 590 ml) and the amount of blood transfused was also significantly higher in non-drained patients (0.98 unit versus 0.54 unit). CONCLUSION: Following primary hip or knee arthroplasty, the use of wound drainage did not lead to increased blood loss, and non-drainage did not lead to significant wound healing problems but did not reduce blood loss and transfusion requirements. It was even associated, following TKR, with greater blood loss and transfusion. Such data may therefore be used to support drainage as well as non-drainage following THR or TKR. Avoiding drainage may be interesting in terms of cost, but the benefit is marginal; it also eliminates one possible source of retrograde wound infection. Systematic wound drainage following THR or TKR is essentially a tradition. This study shows that it can safely be dispensed with in a number of cases.

Adult↗
PubMed2001

Ranging pattern and use of space in a group of red howler monkeys (Alouatta seniculus) in a southeastern Colombian rainforest.

We studied a group of red howler monkeys (Alouatta seniculus) bordering a lake in an eastern Colombian Amazon rainforest for 10 months. The group used an area of 182 ha located mainly on Pleistocene terrace forest and had no overlap with other howler home ranges. Home range use varied through the year as a consequence of fruit and leaf abundance. For example, during the fruit scarcity season the group used an area of flooded forest nearly exclusively, indicating that at least for a portion of the year they are habitat specialists. Two areas intensively used by the group were identified, representing 17.6 % of the home range, and within which 56.9 % of the feeding trees were located. Overall density of feeding trees within the group's home range was very low (1.12 trees/ha). Home range size, as well as mean length of daily ranges (1,150 m), is the largest reported for this species to date, and it is likely a consequence of the diminished productivity of the plant communities on poor soil. Our results give an interesting example of the ranging behavior of this primate, which clearly differs from previous descriptions of red howlers.

Alouatta↗
PubMed2001

Villoglandular adenocarcinoma of the vulva.

BACKGROUND: Only two previous cases of villoglandular adenocarcinoma of the vulva, an entity morphologically similar to tumors found in the uterine cervix and colorectum, have been reported. This paper communicates the first complete immunohistochemical study in villoglandular adenocarcinoma in order to determine its phenotype and histogenesis. CASE: A 69-year-old woman had a 1.5-cm nodule in the right labium majus. Histologically, it corresponded to a minimally atypical, villoglandular adenocarcinoma with a small microinvasion. Immunohistochemically, it was positive to OC125, CEA, and OC19.9 and coexpressed cytokeratins 7 and 20. Chromogranin, nuclear estrogen, and progesterone receptors were negative. CONCLUSION: Phenotypic expression was more consistent with a papillary mucinous ovarian or cervical neoplasm than of a colonic one. Its behavior was similar to that of its morphologic counterpart in the cervix, since the patient had no recurrence 3 years after a wide local excision.

Adenocarcinoma↗
PubMed2001

Acute respiratory distress syndrome among trauma patients: trends in ICU mortality, risk factors, complications and resource utilization.

OBJECTIVE: To evaluate trends in mortality and related factors among trauma patients who developed acute respiratory distress syndrome (ARDS). STUDY: Observational study based on data prospectively gathered in computerized trauma registry. SETTING: Trauma intensive care unit (ICU) of 48 beds in level I trauma center. PATIENTS: All trauma patients with ARDS admitted during 1985-87 (486, group 1 [G1]) and 1993-95 (552, group 2[G2]). METHODS: ARDS was defined by American-European Consensus Conference criteria and the need for 48 h or more on mechanical ventilation with FIO2 greater than 0.50 and PEEP of more than 5 cmH2O. Demographics, severity score, injury-admission delay time, first 24-h transfusion and septic and organ system failure complications were independent variables. ICU mortality was the dependent variable. ICU length of stay (LOS) and life support techniques were considered. Respiratory and renal support strategies were different in the two time periods. RESULTS: Mortality decreased over the period (G1: 29.2% vs G2: 21.4%, p < 0.04), in patients aged both over and under 65 years. Multivariate analysis showed mortality was related to age, severity and time period (G1 1.68-fold that in G2) and that the greater G1 mortality was related to more renal failure and hematologic failure/dysfunction. ICU LOS decreased from 31.7+/-26.7 days (G1) to 27.3+/-22 days (G2) (p < 0.003). CONCLUSIONS: Mortality among trauma patients with ARDS declined over the 8 years studied and was associated with less organ failure. This reduction was probably the result of new approaches to mechanical ventilation, renal failure replacement and vasoactive drug therapy.

Adult↗
PubMed2001

How to overcome matrix effects in the determination of pesticides in fruit by HPLC-ESI-MS-MS.

A high-performance liquid chromatographic method, with electrospray ionisation tandem mass spectrometry (HPLC-ESI-MS-MS) for detection, has been developed for the determination of thiabendazole, carbendazime, and phenylurea pesticides in fruit matrices. During the validation process the method was tested for matrix effects, blanks, and the stability of the system. Considerable unspecific matrix effects in the ESI (+) process were detected by comparing standard calibration, and matrix calibration, although blank values were very low and the specific calibration functions showed only small standard deviations. This effect was overcome by using a more complex clean-up, i.e. an additional size-exclusion step.

Calibration↗
PubMed2001

Argentine Randomized Study: Coronary Angioplasty with Stenting versus Coronary Bypass Surgery in patients with Multiple-Vessel Disease (ERACI II): 30-day and one-year follow-up results. ERACI II Investigators.

OBJECTIVE: The purpose of this study was to compare percutaneous transluminal coronary revascularization (PTCR) employing stent implantation to conventional coronary artery bypass graft surgery (CABG) in symptomatic patients with multivessel coronary artery disease. BACKGROUND: Previous randomized studies comparing balloon angioplasty versus CABG have demonstrated equivalent safety results. However, CABG was associated with significantly fewer repeat revascularization procedures. METHODS: A total of 2,759 patients with coronary artery disease were screened at seven clinical sites, and 450 patients were randomly assigned to undergo either PTCR (225 patients) or CABG (225 patients). Only patients with multivessel disease and indication for revascularization were enrolled. RESULTS: Both groups had similar clinical demographics: unstable angina in 92%; 38% were older than 65 years, and 23% had a history of peripheral vascular disease. During the first 30 days, PTCR patients had lower major adverse events (death, myocardial infarction, repeat revascularization procedures and stroke) compared with CABG patients (3.6% vs. 12.3%, p = 0.002). Death occurred in 0.9% of PTCR patients versus 5.7% in CABG patients, p < 0.013, and Q myocardial infarction (MI) occurred in 0.9% PTCR versus 5.7% of CABG patients, p < 0.013. At follow-up (mean 18.5 +/- 6.4 months), survival was 96.9% in PTCR versus 92.5% in CABG, p < 0.017. Freedom from MI was also better in PTCR compared to CABG patients (97.7% vs. 93.4%, p < 0.017). Requirements for new revascularization procedures were higher in PTCR than in CABG patients (16.8% vs. 4.8%, p < 0.002). CONCLUSIONS: In this selected high-risk group of patients with multivessel disease, PTCR with stent implantation showed better survival and freedom from MI than did conventional surgery. Repeat revascularization procedures were higher in the PTCR group.

Aged↗
PubMed2001

Removal of an airborne low volatility metal under fuel-rich and fuel lean conditions through condensation onto soot and/or sorbent particles.

The removal by a sorbent of a low volatility heavy metal, barium, from a combustor exhaust stream was investigated experimentally. The barium was introduced into the gas phase through a combustion process simulating incineration of waste materials. Sorbent- and metal-feed-rate, temperature and air intake were varied to study the impact on the gas-to-particle conversion and the metal condensation process. Peak temperature and subsequent temperature drop were found to be the dominant factors affecting the condensation process. Fuel-rich and fuel-lean conditions result in lower peak temperatures and a more rapid temperature drop relative to stoichiometric conditions. Since the metal vapor saturation pressure falls exponentially with temperature a larger condensation rate was observed, as long as nucleation was suppressed. Fuel-rich conditions promote the formation of soot particles. These particles function as sites for subsequent metal-species condensation. Chlorine was injected into the flow, to study the effect on metal vaporization. Chlorine promoted the volatilization of barium and therefore the subsequent condensation capture was made more effective.

Adsorption↗