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Biomedical subjects

F Castro

Publications and source records attributed to F Castro.

At least 19 recordsLinked to original sources
PubMed2001

Tumour necrosis factor microsatellites and HLA-DRB1*, HLA-DQA1*, and HLA-DQB1* alleles in Peruvian patients with rheumatoid arthritis.

OBJECTIVE: To study the association between rheumatoid arthritis (RA) and HLA and tumour necrosis factor (TNF) polymorphism in Peruvian mestizo patients in comparison with ethnically similar controls. METHODS: Seventy nine patients with RA and 65 ethnically matched healthy controls were genotyped for HLA-DRB1, HLA-DQA1, HLA-DQB1, and TNFalpha and TNFbeta alleles using PCR amplification. Clinical severity was assessed as mild, moderate, or severe in 35 of the patients. RESULTS: TNFalpha6 showed the strongest association with disease susceptibility. The TNFalpha6 allele was more common in patients than in controls (p<0.0076) and the proportion of patients with at least one copy of this allele was greater (p<0.015, relative risk 2.35). Among the HLA-DRB1* alleles with the shared epitope sequence, only the DRB1*1402 allele was significantly increased in patients compared with controls (p<0.0311), as was the proportion of patients with at least one copy of this allele (p<0.0232, relative risk 2.74). In contrast, the overall frequency of alleles with the shared epitope was not different in patients and controls. The haplotype HLA-DRB1*1402-DQB1*0301-DQA1*0401 was significantly more common in patients. TNFalpha6 was more common in patients whether or not they had this haplotype. None of the 11 patients lacking the TNFalpha6 allele had severe disease. CONCLUSIONS: This study shows for the first time that TNF gene polymorphism is associated with susceptibility to RA in a non-white population. TNFalpha6 and HLA-DRB1*1402 independently conferred significantly increased risk in Peruvian mestizo patients.

Alleles↗
PubMed1999

Controlled study of early postoperative parenteral nutrition in children.

BACKGROUND/PURPOSE: Nutritional support of surgical patients has improved in recent years because of the possibility of modulating catabolism and anabolism, thus enhancing the immune response and repair processes. The objective of this study was to evaluate metabolic effects of early parenteral nutrition (PN) after major surgery. METHODS: The authors studied 63 children aged 4 to 14 years with diffuse peritonitis caused by perforated-suppurative appendicitis. They were assigned randomly to a study group (SG, n = 31), which received PN for 5 days, starting 24 to 48 hours after surgery or to a control group (CG, n = 32), that received standard treatment (fluids). Weight, C-reactive protein (CRP), albumin, prealbumin, glycemia, nitrogen balance (NB), and insulinlike growth factor (IGF-I), were evaluated on postoperative days 1, 4, and 6. RESULTS: Early nutritional support was associated with a significant improvement in NB and IGF-I (Repeat measures analysis of variance IGF-I, P<.001 and NB P<.01). CONCLUSIONS: The authors conclude that early parenteral nutrition has a positive effect on the anabolic response as shown by improved NB and higher IGF-I levels in pediatric patients after major surgery.

Adolescent↗
PubMed1999

Acid phosphatase polymorphism in European shad (Fish: Clupeids).

Genetic polymorphism of acid phosphatases was investigated in 11 populations of the two European Alosa species using isoelectric focusing after sample treatment with neuraminidase. Two distinct loci, ACP1 and ACP2, were detected being ACP2 polymorphic. The observed genetic diversity between the species at the ACP2 locus supports other studies which indicate that A. alosa is the less polymorphic species of the two. This locus shows a higher geographic than interspecific pattern of differentiation and the ACP*2 allele is essentially confined to the Mediterranean.

Acid Phosphatase↗
PubMed1999

A study of an educational intervention to decrease inappropriate preoperative autologous blood donation: its effectiveness and the effect on subsequent transfusion rates in elective hysterectomy.

BACKGROUND: Decreasing the overcollection of preoperative autologous blood is difficult to achieve. The purpose of this study was to determine whether an educational intervention designed to outline the risks of preoperative autologous collection can decrease such donations and, if so, to determine how this decrease will affect subsequent transfusion rates. STUDY DESIGN AND METHODS: An educational intervention consisting of a didactic presentation to the Department of Gynecology staff about the risks and benefits of autologous blood was implemented. Written material with similar information was given to patients. Subsequently, the percentage of patients donating autologous blood, the number of autologous units donated, and the rates of transfusion in patients eligible for autologous donation who were admitted for elective abdominal or vaginal hysterectomy were measured. These rates were compared to those in similar patients admitted in the 2 years before the educational intervention. RESULTS: After an educational intervention, the proportion of patients donating autologous blood decreased from 53 percent to 26 percent (p<0.01), and the number of units collected per patient decreased from 0.86 to 0.31 (p<0.01); this resulted in a savings of 80 autologous donations per year. Despite no difference in estimated blood loss (p = 0.46), the overall transfusion rate decreased from 10 percent to 3.7 percent (p = 0.03), while the allogeneic transfusion rate demonstrated no significant change (1.1% vs. 2.2%; p = 0.40). CONCLUSIONS: Unnecessary preoperative autologous donations by elective hysterectomy patients can be decreased by educating physicians and patients about the risks of preoperative autologous blood donation. Decreasing such unnecessary donations can decrease the subsequent autologous transfusion rate, with its attendant risks, without increasing the risk of allogeneic transfusion.

Blood Transfusion, Autologous↗
PubMed1999

Chemical modification of pure titanium surfaces for oral implants.

A technique that achieves different pure titanium surfaces depending on acid concentration and exposure time is described. It is possible to obtain, with the same chemical treatment, both large pits and small rugosities. This technique may have interesting applications in oral implants.

Dental Implantation, Endosseous↗
PubMed1998

Screening for carotid and renal artery stenoses in patients with aortoiliac disease.

Patients with severe stenoses of the carotid and renal arteries define a population at high risk but most of them are asymptomatic. Here arises the question of who must be tested and what would be the actual utility of a screening program in the general or selected populations. The aim of this study was to assess the efficacy of a duplex-based screening for carotid and renal arteries stenoses, in a subset of patients with aortoiliac arterial disease, in terms of: (1) prevalence of occlusive disease of the carotid and renal arteries detected and surgical procedures generated; (2) analysis of clinical variables that could be useful to increase the suspicion index for the disease; and (3) predictive values of duplex scanning adjusted for the observed prevalence. One hundred sixty eight consecutive patients selected for elective aortoiliac surgery were included. Carotid duplex scanning, renal duplex scanning and/or aortorenal angiography, and recording of clinical predictive variables were obtained in all the patients. The statistical analysis included prevalence rates, multivariate analysis, and predictive values of carotid and renal duplex scanning adjusted for the observed prevalence. Greater than 50% asymptomatic stenosis in at least one of the internal carotid arteries (CAS > 50%) was detected in 47 (28%) patients [95% confidence interval (CI): 21.2%-34.8%]; 67 (39.9%) patients showed greater than 60% stenosis in one or both renal arteries (RAS > 60%) (95% CI: 32.5%-47.3%). Based on current surgical indications, carotid endarterectomy was performed in 24 (14.3%) patients and a bypass to the renal artery in 30 (17.8%) patients. Logistic regression analysis accepted the following variables, in this order: carotid bruit, age, and ankle/brachial index for predicting carotid artery stenosis; and hypertension and CAS for predicting renal artery stenosis. Based on previous validation studies of duplex scanning accuracy, estimated positive predictive values for significant stenosis of the carotid and renal arteries showed a range of 80.5%-89.1% and 82.3%-89.7%, respectively. Routine screening of the carotid and renal arteries may be justified in those patients with aortoiliac aneurysmal and occlusive disease, provided there is a high prevalence of clinically significant lesions and sufficient predictive values of duplex scanning are obtained.

Aged↗
PubMed1998

Urea reduction ratio and urea kinetic modeling: a mathematical analysis of changing dialysis parameters.

Based mainly on the simplicity of its calculation, the urea reduction ratio (URR) has been suggested as an alternative to urea kinetic modeling (Kt/V) as a measure of hemodialysis adequacy. However, recent studies have raised questions concerning the accuracy of URR, particularly in the presence of residual kidney function (KrU). This study was initiated to evaluate the relationship between URR and Kt/V under a variety of dialysis conditions. Equations based on the variable-volume, single-pool model described by Gotch were used to construct a model incorporating the variables used in the estimation of URR and Kt/V. The model's prediction of URR correlated closely with measured URR in 30 patients (r = 0.9987, p < 0.000001). This analytic approach showed that changes in each of several dialysis parameters caused divergence in the values of URR and Kt/V. The model showed that URR could be less than 0.65, while total Kt/V was greater than 1.2, whether or not KrU was present. In fact, when KrU was greater than 1. 0, URR could be less than 0.65, while Kt/V might be 2.0 or higher. On the other hand, the model showed instances where URR could be greater than 0.65, when Kt/V was less than 1.2. This occurred only when KrU was less than 1.0. To determine the prevalence of these anomalies in clinical practice, 767 kinetic modeling determinations were evaluated in 207 patients. One of the above discrepancies was observed at least once in 30.9% of the patients, representing 12.1% of all determinations. In addition, it was found that omitting KrU from the calculation of Kt/V generally leads to a Kt/V <1.2. This, when associated with a URR <0.65, could erroneously imply inadequate dialysis. The patient data are consistent with the view that URR and Kt/V are the net result of several variables that may act together or even in opposing directions. Based on this mathematical model and the observed clinical data, the use of URR alone to assess dialysis adequacy, or neglecting the contribution of KrU to Kt/V, may lead to changes in the dialysis prescription that are neither correct nor necessary.

Aged↗
PubMed1998

Chronic hepatitis C: treatment comparison between 3 and 5 million units of interferon alpha-2b.

Interferon (IFN) is the only drug that has been approved by the FDA for therapy of chronic hepatitis C. However, optimal dose and duration of therapy are still controversial. This study compares the effectiveness of treatment of chronic hepatitis C patients with 3 vs. 5 million units (MU) of recombinant alpha-interferon 2-b three times per week. We also evaluated the relapse rate with a shorter 12 week-course of therapy in those patients who had normalization of aminotransferases by week 12. Seventy-five patients were randomized to receive either 3 vs. 5 MU of IFN; seventy-two completed the study. A complete response was seen in 11/35 (31%) of those treated with 5 MU vs. 13/37 (35%) in the 3 MU dose (p = 0.74). Patients were followed after IFN was withdrawn and only 2 had persistently normal aminotransferases. Analysis of multiple variables was done to predict response to IFN and only elevations of GGT, ferritin and alkaline phosphatase were found to be predictors of a poor response. Therefore, we recommend initial therapy with 3 MU of IFN for a longer period than 12 weeks in patients who show a response.

Adult↗
PubMed1997

Sustained response to interferon in a patient with common variable immunodeficiency and hepatitis C.

Hepatitis C infection progresses faster in patients with hypogammaglobulinemia, often leading to death from liver failure within 10 yr of exposure. Response to interferon treatment has been poor in these patients. We report the case of a patient with common variable immunodeficiency and hepatitis C in whom a sustained biochemical and viral remission was obtained after treatment with interferon.

Adult↗
PubMed1997

"H" reflex as a measure of subclinical uremic polyneuropathy in children with chronic renal failure.

Uremic polyneuropathy (UPNP) is a serious complication of chronic renal failure (CRF) in adults; however, its prevalence is unknown in the pediatric population. An easy-to-perform maneuver for its detection in children is the evaluation of "H" reflex. The objective of this study was to validate the usefulness of the "H" reflex maneuver for the diagnosis of UPNP in pediatric dialysis patients for CRF. Thirty-seven CRF patients were paired with healthy controls by age and sex. The patients were being treated with dialysis or one of its variants. Information was obtained regarding diagnosis, duration, and control of dialysis. Neurological examination was performed, conduction velocities in sensory and motor nerves were measured, and "H" reflex elicited bilaterally. Peripheral polyneuropathy was determined by the presence of at least two nerves with alterations in latency and/or conduction velocities. It was found that 59.4% (22/37) of the children with CRF treated with dialysis developed UPNP, 17 with ambulatory peritoneal dialysis, and 5 with hemodialysis. There was no difference in diagnosis, duration of dialysis, or control of the same in these patients from other CRF patients who did not have UPNP. All patients were clinically asymptomatic. "H" reflex showed a sensibility of 44%, a specificity of 87%, a predictive value positive of 66%, and a predictive value negative of 76%, when measured to 28 msec. With a 30 msec duration specificity rises to 95%. UPNP presents asymptomatically in pediatric patients. "H" reflex is an adequate screening test for the selection of pediatric patients to be tested further.

Adolescent↗
PubMed1996

Preoperative autologous blood donations before elective hysterectomy.

OBJECTIVE: To determine whether preoperative autologous blood donation is justified for patients undergoing elective abdominal or vaginal hysterectomy. DESIGN: Retrospective cohort study. PATIENTS AND SETTING: A total of 263 consecutive patients admitted for elective abdominal or vaginal hysterectomy to a community health maintenance organization hospital during 1993 and 1994. MAIN OUTCOME MEASURES: Evaluation of transfusion rates for patients who did and did not donate autologous blood; determination of any risk factors that would predict the need for transfusion; and evaluation of the need for transfusion based on chart review. RESULTS: Of 263 patients, 26 received a blood transfusion. The major risk factor identified for transfusion was the donation of autologous blood. Of 140 patients who donated autologous blood, 25 were transfused, whereas just 1 patient of 123 who did not donate autologous blood was transfused (P<.001). Patients who donated autologous blood had significantly lower mean admission hemoglobin level than patients who did not donate (119 g/L vs 132 g/L; P<.05); logistic regression showed that autologous donation was an independent risk factor for transfusion. CONCLUSION: For hysterectomy patients, donation of autologous blood causes anemia and is associated with a more liberal transfusion policy. These 2 factors result in a markedly increased incidence of transfusion with its associated risks. Elimination of preoperative autologous donation for these patients should not result in frequent exposure to allogeneic blood.

Adult↗
PubMed1996

Cost of implanting a cemented versus cementless femoral stem.

Fifty stratified unselected cases of primary uncomplicated total hip arthroplasty performed at the total joint service of a university teaching hospital were examined. In 25 cases, the femoral stem was implanted with cement, and in the other 25, a cementless stem was implanted. For cemented stems, third-generation cement technique was used, including centrifugation. The average cost to the hospital for a cementless stem was $900 greater than for a cemented stem. The total cost to the hospital for accessories used to achieve modern cement technique was over $700. The operative time for implanting a cemented stem averaged 20 minutes longer, which resulted in an additional operating time charge of $270 and an additional anesthesia charge of $100. When these charges are added to the cost of cement and accessories, the actual cost to the hospital for implanting a modern cemented stem was greater than for a corresponding cementless stem.

Bone Cements↗
PubMed1996

Xanthogranulomatous pyelonephritis associated with transitional cell carcinoma of the renal pelvis.

Xanthogranulomatous pyelonephritis (XPN) is an uncommon, but not rare, type of bacterial infection of the kidneys. Malignancies originating within the renal pelvis are uncommon. We report a case of XPN associated with a transitional cell carcinoma (TCC) of the renal pelvis in a 70-year-old woman. The pathogenesis of carcinoma of the renal pelvis in the presence of XPN is related to obstruction, chronic inflammation, and mechanical irritation caused by calculi. In the case reported here, obstruction was due to a concomitant TCC of the ureter without the presence of calculi. A review of the twelve published case reports of XPN with TCC of the renal pelvis, including the present case, showed that the frequency of this association is 3.3%, the average age at presentation is 65.3 (range 49-78) years, and that the male:female ratio is 2:1. Moreover, 25% of the patients had TCC of the ureter and 8.3% TCC of the bladder. The combination of XPN, TCC of the renal pelvis, and lithiasis occurred in 33.3% of the cases. XPN must be treated by nephrectomy not only because it is a destructive inflammatory process leading to complete loss of renal function, but also because the kidney may be harboring a malignant tumor.

Adult↗
PubMed1996

Prevention of recurrent esophageal bleeding and survival in patients with alcoholic cirrhosis: a randomized study.

OBJECTIVES: To compare endoscopic sclerotherapy, propranolol and distal splenorenal shunt in the prevention of rebleeding esophageal varices and mortality in alcoholic cirrhotics. METHODS: Forty-three alcoholic cirrhotics that had bled from esophageal varices were randomized to sclerotherapy (13), shunt (15) or propranolol(15). Outcomes measured were rebleeding from varices and death. RESULTS: There was no significant difference between the three treatment groups in relation to rebleeding rate or death. Continued alcohol consumption did not influence outcome. CONCLUSIONS: All three therapies were equally effective in preventing rebleeding from varices.

Adult↗
PubMed1995

[Research on prognostic factors in large-cell lymphomas].

BACKGROUND: To carry out a study on the prognostic factors in large cell lymphomas (LCL) treated during the last decade and validate the international prognostic index (IPI). METHODS: One hundred twenty-four cases of newly diagnosed LCL, treated from 1978 to 1990, with a mean follow up of 27 months (1-142) were included in the study. The chemotherapy used was: CHOP (65%), ProMACE-CytaBOM (17%) and others (C-MOPP, MACOP-B). RESULTS: Complete remission (CR) was achieved in 71% of the cases and partial in 11%. Logistic analysis allowed the identification of three adverse factors to CR: Ann Arbor stage III, IV (p = 0.004; odds ratio, OR = 0.19), elevated tumoral load (p = 0.006; OR = 0.22) and age > or = 60 years (p = 0.02; OR = 0.31). Recurrence free survival (RFS) at 3 years was 67% (CI 95%; 55-79) with the median not having been achieved. Cox analysis allowed the identification to the ECOG > or = 2 scale as the only independent adverse factor (p = 0.0006; RR = 4.85) while Ann Arbor staging demonstrated marginal influence (p = 0.08). Global survival (GS) at 5 years was 45% (CI 95%; 35-55) with a median of 38 months. Multivariant analysis of independent adverse factors of GS were ECOG scale > or = 2 (p < 0.00001; RR = 6.07), Ann Arbor stage (p = 0.004; RR = 2.64) and hypoalbuminemia (p = 0.01; RR = 2.28). On inclusion of therapeutic response (TR) in the analysis, the factors chosen were absence of CR (p < 0.00001; RR = 9.58) and ECOG > or = 2 (p = 0.0004; RR = 4.24). CONCLUSIONS: Three variables evaluated at diagnosis, general state (ECOG), Ann Arbor stage and albumin, determined the prognosis in this series of large cell lymphoma. A prognostic model was designed from the same with three risk groups. The application of the international prognostic index to this series separated the patients into 4 groups of differentiated prognosis.

Adolescent↗