Search PubMed⌕ Search

Biomedical subjects

R Ramos

Publications and source records attributed to R Ramos.

At least 55 records · Page 3Linked to original sources
PubMed1999

Donor age and delayed graft function as predictors of renal allograft survival in rejection-free patients.

BACKGROUND: Transplant recipients of kidneys harvested from old donors have a high incidence of delayed graft function (DGF) and a poor graft outcome. This result is partly explained by the increased incidence of acute rejection in patients suffering from DGF. However, the long-term impact of donor age and DGF in rejection free renal transplants is not well established. The aim of the present work is to evaluate the impact of donor age and DGF on long-term outcome in renal transplants with or without acute rejection. PATIENTS: We review all cadaveric kidney transplants performed in our centre between April 1984 and December 1995 treated with a cyclosporin-based immunosuppression. RESULTS: Five hundred and ninety-five patients were included. The overall incidence of DGF was 29.1%, and this event was associated with an increased donor age and cold ischaemia time. Univariate and multivariate analysis showed that graft loss was associated with acute rejection (relative risk (RR) 2.24, 95% confidence interval (CI) 1.62-3.01); DGF (RR 1.83, 95% CI 1.32-2.54); donors >50 years (RR 1.65, 95% CI 1.13-2.38); and retransplantation (RR 1.52, 95% CI 1.01-2.31). In rejection-free patients there were two independent predictors of graft failure: donor >50 years (RR 2.40, 95% CI 1.45-4.01); and DGF (RR 2.42, 95% CI 1.53-3.84). CONCLUSIONS: Regardless of the presence of acute rejection, delayed graft function amplifies the detrimental effect of advanced donor age on long-term graft outcome.

Adult↗
PubMed1999

Tecatas: an ethnotheoretical look at Mexican American female injecting drug users.

Ethnotheory is suggested as a way to study the roles Mexican American female injecting drug users play. It is suggested that ethnotheory extends present theoretical models used to explain and modify female IDUs' behavior; provide insights on female IDUs' roles useful for the development of effective intervention strategies; and suggests a type of ethnographic data collection that uncovers the subject's view of reality. Three detailed ethnographic excerpts from Mexican American female IDUs illustrate how female IDUs manage the array of roles they play and how information gained through ethnotheory is useful in the design of culturally relevant interventions.

Adult↗
PubMed1999

Identification of the Hb Lepore phenotype by HPLC.

BACKGROUND AND OBJECTIVE: Hb Lepore is a structurally abnormal hemoglobin in which the abnormal globin chain is a hybrid or fused globin chain (db). Three different Lepore hemoglobins have been identified, differing from each other in the point at which the db fusion occurs; Hb Lepore Hollandia (d22/b50), Hb Lepore Baltimore (d59/b86) and Hb Lepore Boston (d87/b116). In Spain only Hb Lepore Boston and Hb Lepore Baltimore have been identified. Hb Lepore is easily detected by electrophoretic and chromatographic studies, whereas the type of Hb Lepore is distinguished by chromatography of tryptic peptides of abnormal db chain. In this work, we show an easier chromatography technique for identifying the Hb Lepore phenotype. DESIGN AND METHODS: Thirteen different unrelated families (23 patients) from different parts of Spain were studied. The existence of Hb Lepore was diagnosed by standard methodology and quantified by ionic exchange HPLC. The globin chains were studied by reversed phase HPLC, which showed us the phenotype of Hb Lepore; this phenotype was corroborated by a gold standard test using molecular biology techniques. The statistical analysis was designed to determine the behavior of the quantitative (hematologic) variables using the independent variable (Hb Lepore Baltimore or Hb Lepore Boston) categorized by Student's t-test for independent groups. The distribution of the variable was established using theoretical models and the variance homogeneity hypothesis was tested. The validity of the hematologic data was estimated by creating a receiver operating characteristic (ROC) curve. RESULTS: In the study of globin chains by reversed phase HPLC, in 14 patients (8 families) three peaks were eluted; they corresponded to a, b and db globin chains. In these cases when DNA was studied by PCR followed by digestion with the restriction enzyme Pvu II, the phenotype of Hb Lepore was identified as being the Boston variant, whereas in the rest of patients (9 in total), the peak identified with hybrid chain globin (db) was not present and the molecular study showed that these patients were heterozygotes for Hb Lepore Baltimore. INTERPRETATION AND CONCLUSIONS: The study of globin chains by reversed phase HPLC is sufficient to know the phenotype of Hb Lepore and thus tedious techniques such as chromatography of tryptic digestion product of db abnormal chains are not essential, a particularly important consideration in those laboratories that do not have the possibility of carrying out molecular biology studies. Neverteheless, we should continue to use a gold standard molecular biology test in cases of prenatal diagnosis because this technique is the most exact and reproducible that we have.

Chromatography, High Pressure Liquid↗
PubMed1998

Low-dose cyclosporine and mycophenolate mofetil in renal allograft recipients with suboptimal renal function.

BACKGROUND: Cyclosporine (CsA) nephrotoxicity can be identified by functional changes and chronic renal damage. CsA-associated renal fibrosis has been related to the overproduction of transforming growth factor (TGF)-beta1, a fibrogenic cytokine. Mycophenolate mofetil (MMF) may allow CsA dose reduction without increasing the risk of rejection. METHODS: We studied the impact of CsA dose reduction in association with MMF on renal function and TGF-beta1, production in 16 long-term renal allograft recipients with suspected CsA nephrotoxicity. Two grams/day of MMF were introduced, and CsA dose was reduced to reach whole-blood levels between 40 and 60 ng/ml within 1 month. CsA dose and levels, renal function parameters, and platelet-poor plasma TGF-beta1 levels were evaluated before and 6 months thereafter. RESULTS: MMF allowed a decrease in both the mean dose of CsA (3.8+/-1.35 vs. 2.2+/-0.73 mg/kg/day; P<0.01) and CsA levels (148+/-36 vs. 53+/-19 ng/ml; P<0.001). The reduction of CsA was associated with a decrement of serum creatinine levels (210+/-46 vs. 172+/-41 micromol/L; P<0.001) and an increase in both the glomerular filtration rate (32.9+/-12 vs. 39.1+/-14 ml/min/1.73 m2; P<0.02) and renal plasma flow (195+/-79 to 218.6+/-74.02 ml/min/1.73 m2; P<0.02). There was a reduction in plasma TGF-beta1 levels (4.6+/-4.2 vs. 2.0+/-1.4 ng/ml; P=0.003) and CsA levels correlated with TGF-beta1 (r=0.536, P=0.002). No rejection episodes occurred, and an improvement in both systolic (149+/-13 vs. 137+/-12 mmHg; P<0.01) and diastolic blood pressure (89+/-14 vs. 83+/-10 mmHg; P<0.04) were observed. CONCLUSIONS: These short-term results show that MMF introduction allows a CsA dose reduction, which improves renal function, reduces TGF-beta1 production, and improves the control of hypertension, without increasing the incidence of acute rejection.

Adult↗
PubMed1998

Secondary pleural involvement by an AIDS-related anaplastic large cell (CD30+) lymphoma simulating metastatic adenocarcinoma.

We report a patient with acquired immunodeficiency syndrome with secondary pleural and pulmonary involvement by a CD30+ anaplastic large cell lymphoma (ALCL) that morphologically simulated metastatic adenocarcinoma. We describe the morphologic findings in order to heighten awareness that CD30+ ALCL may mimic metastatic adenocarcinoma in a body fluid or bronchial brushing and should be considered in the differential diagnosis. Primary body cavity based (PCBC) AIDS-related lymphoma is a relatively newly described disease entity with morphologic features bridging ALCL and large cell immunoblastic lymphoma with a CD30+ null immunophenotype. A morphology mimicking adenocarcinoma has not been previously described in this entity but should be considered in a patient with AIDS presenting exclusively with a serous effusion. Appropriate immunoperoxidase staining should aid in these differential diagnoses.

Adenocarcinoma↗
PubMed1998

Transrectal ultrasonography: relationship with anorectal manometry, electromyography and sensitivity tests in irritable bowel syndrome.

Irritable bowel syndrome is the most frequently diagnosed disorder in gastroenterology. It has been demonstrated with specialized motility studies that these patients compared to healthy subjects show changes in rectoanal electrical and mechanical activity and in rectoanal sensitivity. However, until now no report has been published on morphological alterations in the rectum or the internal anal sphincter. Twenty-five consecutive patients with irritable bowel syndrome (mean age 32, range 17-47 years; 24 females) were evaluated prospectively by transrectal ultrasonography, rectal sensitivity studies, and recordings of both electrical and mechanical activity of the distal rectum and internal anal sphincter during a 2-h inter-digestive period. Ten healthy volunteers (mean age 34.5, range 19-50 years) served as a control group. Paired and non-paired Student's two-tailed t test and linear regression analysis were used. It was shown that muscle thickness of the rectum during rest (4.7 +/- 0.1 mm) was correlated neither with its rectal spike amplitude (0.73 +/- 0.1 mV) nor with rectal spike frequency (17.06 +/- 3.6 spike/2 h). In addition, the diameter of the internal anal sphincter (1.2 +/- 0.1 mm) was correlated neither with its resting pressure, nor with frequency (17.1 +/- 3.2/2 h), duration (14.9 +/- 1.5 s), or amplitude (14.1 +/- 1.9 mmHg), of inhibition of the spontaneous rectoanal inhibitory reflex. No correlation was found between ultrasonographic parameters and rectal distension variables (r = 0.03). This study demonstrates for the first time morphological anorectal changes in patients with irritable bowel syndrome compared to healthy subjects, in addition to showing that morphological changes are independent of physiological ones. Therefore both transrectal ultrasonography to determine anorectal morphology and electromanometry to assess anorectal function are important measures in the evaluation of patients with irritable bowel syndrome.

Adolescent↗
PubMed1998

Users' understanding of the lactational amenorrhea method and the occurrence of pregnancy.

It is unknown whether a user's understanding of the Lactational Amenorrhea Method (LAM) is related to its successful use. A study of 876 LAM users in Pakistan and the Philippines collected information about women's understanding of LAM. The present analysis aims to determine: (1) the proportion of LAM users who understand the method, (2) whether any known factors can distinguish those who understand LAM from those who do not, and (3) whether an understanding of LAM is related to subsequent pregnancy. Over 75% of LAM users could consistently recite the LAM guidelines correctly for a full year postpartum. However, 38% of users failed to display, at least once, an understanding of LAM during the first year postpartum mainly by failing to abstain, to use another method or to explain their nonuse of another method when their LAM protection expired. LAM understanding generally could not be predicted by sociodemographic factors. The occurrence of pregnancy during the first year postpartum was not related to LAM understanding, regardless of how LAM understanding was defined, nor could it be predicted by any other measured characteristic of the users.

Adult↗
PubMed1998

Identifying condom users at risk for breakage and slippage: findings from three international sites.

OBJECTIVES: This study examined whether past condom failure (breakage, slippage, or both) can predict future failure and evaluated other predictors of condom failure. METHODS: At each of 3 international sites, approximately 130 male condom users were enrolled and given 5 condoms to use for vaginal intercourse over a 3-week period. RESULTS: Men at increased risk (history of 1 or more condoms that broke or slipped off) reported approximately twice as many condom failures as those not in this group. Condom failure increased with the number of adverse condom use behaviors reported per participant. Opening condom packages with sharp objects and unrolling condoms before donning were associated with breakage. Unrolling condoms before donning and lengthy or intense intercourse were associated with slippage. Of background characteristics evaluated, having less education was associated with condom failure. CONCLUSIONS: These data suggest that a history of condom failure predicts future failure, a finding that may be useful for targeted intervention. Moreover, these data provide further evidence that certain behaviors and lower educational attainment are associated with condom failure.

Adult↗
PubMed1998

[Obtention and characterization of murine beta-NGF. Application in a model of cerebral aging].

INTRODUCTION: beta-NGF is a basic protein of 118 aminoacids which acts are a trophic factor for sensory and sympathetic neurons of the peripheral nervous system, and on cholinergic neurons of the anterior basal cerebrum. OBJECTIVES: In view of the functional effect of beta-HGF and its possibilities as a therapeutic agent in neurodegenerative disease, including Alzheimer's disease in this study our aim was to obtain, characterize and show the main results of the application of beta-NGFm in a model of cerebral ageing in rats with cognitive disorders. MATERIAL AND METHODS: For the obtention of beta-NGFm we followed Mobley's method as modified by Ebendal and used mouse submaxillary gland as a source of raw material. The characterization studies were carried out by application of seven techniques which allowed physicochemical characterization and demonstration of the biological activity of the product. Application of beta-NGF obtained under these conditions was carried out in a mode of cerebral ageing and the effects of treatment were assessed by conduct studies, measurement of the activity of the enzyme acetyl cholinesterase and study of neural plasticity. CONCLUSIONS: Characterization studies carried out on the beta-NGFm showed that the protein obtained consists of a mixture of molecules of beta-NGFm which are intact at their extreme N-Terminal, and molecules which have lost the octapeptide of the N-terminal position and show some modification increasing hydrophobicity. All these species were recognized immunologically by the specific antibody anti-NGFm and showed biological activity.

Aging↗
PubMed1997

Combining fine-needle aspiration and flow cytometric immunophenotyping in evaluation of nodal and extranodal sites for possible lymphoma: a retrospective review.

The relatively recent evaluation of nodal and extranodal sites for malignant lymphoma by combining fine-needle aspiration (FNA) and flow cytometric immunophenotyping (FCI) techniques has resulted in a most rapid, accurate method. Our study represents a comprehensive retrospective review of in vivo applications of these techniques to cases suspicious for malignant lymphoma. We report our findings, which support the usefulness of these techniques, particularly in diagnosis and staging of primary and recurrent B-cell lymphomas (BCL). The findings of necrosis and numerous polymorphonuclear cells in cases with a previous history of BCL demand tissue biopsy. Initial diagnosis of BCL by FNA and FCI may obviate tissue biopsy.

Biopsy, Needle↗
PubMed1997

Defaecography in patients with irritable bowel syndrome and healthy volunteers.

BACKGROUND: In patients with IBS, many symptoms have their origin in the recto-anal segment, with motility changes in the rectum and in the internal anal sphincter, and alterations in rectal sensitivity. However, up to now, it is not known if these clinical and physiological changes are equated with morphological changes in the recto-anal segment. METHODS: Sixteen consecutive patients with IBS (mean age 22, range 18-33 years; 13 females) and 10 healthy volunteers (mean age 34.5, range 19-50 yr.; 6 males) were evaluated prospectively with defaecography. RESULTS: 1) Anorectal angle: No significant differences were observed in the anorectal angle during rest (91.6 +/- 3.5 degrees vs 92.6 +/- 2.5 degrees) and during defaecation (92 +/- 5.5 degrees vs 98.7 +/- 2.6 degrees) between patients with IBS and healthy volunteers. However, patients with IBS were unable to widen the angle during defaecation, remaining the same at rest (91.6 +/- 3.5 degrees) as during defaecation (92 +/- 5.5 degrees). IBS patients with constipation (n = 2) compared to those with normal frequency defaecation (n = 13) showed no significant differences at rest (95 +/- 6 vs 89.8 +/- 4.1 degrees) and during defaecation (100 +/- vs 88.9 +/- 6.4 degrees). Healthy volunteers widened the angle by more than 5 degrees during defaecation. 2) Perineometry: although not significant, patients with IBS had less perineal descent during the simulated defaecation (1.98 +/- 0.37 cm) than healthy subjects (2.1 +/- 0.3 cm). Nevertheless, during squeeze there was significantly less mobility or perineal descent in patients with IBS than in control subjects (0.21 +/- 0.17 vs 0.95 +/- 0.21 cm; P = 0.01). CONCLUSIONS: The findings of this study suggest that patients with IBS as a whole, whether constipation predominant or not, showed changes in pelvic-floor mobility.

Adolescent↗
PubMed1997

The duration and character of postpartum bleeding among breast-feeding women.

OBJECTIVE: To examine the postpartum bleeding experience of a cohort of breast-feeding women and to compare it with the conventional definition of lochia. METHODS: Four hundred seventy-seven experienced breast-feeding women in Manila, the Philippines, were followed prospectively from delivery and recorded vaginal bleeding in a menstrual diary. The median duration of lochia was calculated using survival analysis. In addition, all bleeding separate from lochia within the first 8 weeks postpartum was noted. RESULTS: The median duration of lochia was 27 days and did not vary by age, parity, sex or weight of the infant, breast-feeding frequency, or level of supplementation. More than one-fourth of the women experienced a bleeding episode separated from the original lochial flow by at least 4 bleeding-free days and beginning no later than postpartum day 56. Ten breast-feeding women may have had their first menstrual bleed before day 56. CONCLUSIONS: Lochia lasted substantially longer than the conventional assumption of 2 weeks. It was common for postpartum bleeding to stop and start again or to be characterized by intermittent spotting or bleeding. Return of menses is rare among fully breast-feeding women in the first 8 weeks postpartum.

Adult↗
PubMed1996

Effectiveness of lactational amenorrhoea in prevention of pregnancy in Manila, the Philippines: non-comparative prospective trail.

OBJECTIVE: To determine the contraceptive efficacy of the lactational amenorrhoea method. DESIGN: Non-comparative prospective trial. SETTING: Urban Manila, the Philippines. SUBJECTS: 485 lower income, educated women with extensive experience of breast feeding. INTERVENTION: Women were offered all available contraceptives for use after birth. Those who chose the lactational amenorrhoea method were taught the method, screened for the study, and followed for 12 months to determine the risk of pregnancy when the method was used. MAIN OUTCOME MEASURES: Life table pregnancy rates during correct and incorrect use of the method, censored monthly in the event of sexual abstinence or the use of another contraceptive method. RESULTS: The lactational amenorrhoea method was 99% effective when used correctly (that is, during lactational amenorrhoea and full or nearly full breast feeding for up to six months). At 12 months the effectiveness during amenorrhoea dropped to 97%. CONCLUSIONS: The lactational amenorrhoea method provided as much protection from pregnancy as non-breast feeding women experience with non-medicated intrauterine devices and barrier methods. The contraceptive effect of lactation cannot be attributed to lactational or postpartum abstinence.

Adult↗
PubMed1996

Paraumbilical venous collateral circulations: color Doppler ultrasound features.

Using Color Doppler ultrasonography to trace the dilated paraumbilical vein to its connection with systemic veins in 27 patients, we have found four major pathways: In type 1 (63%), the vein connected with the external iliac vein via the inferior epigastric vein. In type 2 (3.7%), the vein connected with the saphenous vein via the superficial epigastric vein. In type 3 (22.2%), the vein connected with the internal thoracic vein via the superior epigastric vein. Type 4 (11.1%) is a combination of types 1 and 2. A frank caput medusa was not seen, but occult caput medusa were seen in two patients. Turbulent flow was seen at the junction between inferior epigastric and external iliac veins, paraumbilical and superficial epigastric veins, and superficial epigastric and saphenous veins in some patients. Color Doppler ultrasonography is a convenient, noninvasive method for determining the course and associated hemodynamic changes in the paraumbilical collateral circulation.

Adult↗