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Biomedical subjects

V Ortiz

Publications and source records attributed to V Ortiz.

At least 19 recordsLinked to original sources
PubMed2006

Oligozoospermia and heat-shock protein expression in ejaculated spermatozoa.

BACKGROUND: Heat-shock protein A2 (HspA2) is correlated with sperm maturity, function and fertility, and a dysfunctional expression of such a gene results in abnormal spermatogenesis. The purpose of this study was to compare HspA2 gene expression in spermatozoa from oligozoospermic men and normozoospermic controls. METHODS: Semen was obtained and analysed according to World Health Organization (World Health Organization, 1999) guidelines, morphology by Kruger's strict criteria. Seventeen patients with oligozoospermia and 21 fertile controls were studied. Total RNA was extracted from ejaculated and Percoll density-gradient-separated spermatozoa followed by semiquantitative RT-PCR analysis. The relative expression level of HspA2 was analysed according to the expression level of the housekeeping beta-actin gene. Serum hormonal profiles (FSH, LH and testosterone) and a peripheral karyotype were also performed. RESULTS: All patients possessed normal karyotype, and no significant hormonal differences were found between the two groups. The study group had significantly lower sperm concentration and normal morphology than the controls. Semiquantitative RT-PCR analysis of HspA2 showed significantly lower expression levels in the oligoteratozoospermic men when compared to controls (P=0.0021). CONCLUSIONS: The HspA2 gene was down-regulated in sperm from infertile men with idiopathic oligoteratozoospermia, suggesting that such anomalies of gene expression might be associated with pathogenesis in some subtypes of male infertility.

Actins↗
PubMed2005

How to engage medical students in chronobiology: an example on autorhythmometry.

This contribution describes a new laboratory experience that improves medical students' learning of chronobiology by introducing them to basic chronobiology concepts as well as to methods and statistical analysis tools specific for circadian rhythms. We designed an autorhythmometry laboratory session where students simultaneously played the role of researchers and experimental subjects. During this session, which lasted 24 h, students recorded their own arterial pressure, heart rate, oral temperature, forced expiratory flow, glucose tolerance, muscular strength, reaction time, and sensorimotor coordination at regular intervals and also took the Horne and Ostberg test, after which they analyzed their own data. Furthermore, to gather information from subjects under normal sleep and eating schedules, some students acquired data at home. To guide and help students with their work, a dedicated web page was implemented with scientific references, cosinor analysis software, and other valuable information. All these "raw" data were combined into a single database that students could use to evaluate whatever aspect of the data they seemed fit. A number of suggestions were offered to them as guidance. Students were then instructed to write a scientific article on the subject they had chosen. The experience was highly rewarding for both instructors and students alike. In view of the high level of absenteeism in Spanish universities and the fact that 93% of the students attended the exam and 95% of these passed, the experience was considered a great success.

Adult↗
PubMed2005

[Gastroesophageal reflux disease refractory to esomeprazole].

Resistance to proton pump inhibitors (PPI) in gastroesophageal reflux disease (GERD), which has been described in patients treated with omeprazole, could explain some exceptional cases of treatment failure and the need for surgery. The objective test of resistance to PPI is obtained with 24-hour intragastric pH-metry performed during treatment. A gastric pH of less than 4 for more than 50% of recording time indicates resistance. We present a patient with non-erosive GERD and treatment failure to omeprazole and proven resistance to esomeprazole which, to our knowledge, has only been reported in patients with Barrett's esophagus.

Adult↗
PubMed2004

Acquiring 4D thoracic CT scans using a multislice helical method.

Respiratory motion degrades anatomic position reproducibility during imaging, necessitates larger margins during radiotherapy planning and causes errors during radiation delivery. Computed tomography (CT) scans acquired synchronously with the respiratory signal can be used to reconstruct 4D CT scans, which can be employed for 4D treatment planning to explicitly account for respiratory motion. The aim of this research was to develop, test and clinically implement a method to acquire 4D thoracic CT scans using a multislice helical method. A commercial position-monitoring system used for respiratory-gated radiotherapy was interfaced with a third generation multislice scanner. 4D cardiac reconstruction methods were modified to allow 4D thoracic CT acquisition. The technique was tested on a phantom under different conditions: stationary, periodic motion and non-periodic motion. 4D CT was also implemented for a lung cancer patient with audio-visual breathing coaching. For all cases, 4D CT images were successfully acquired from eight discrete breathing phases, however, some limitations of the system in terms of respiration reproducibility and breathing period relative to scanner settings were evident. Lung mass for the 4D CT patient scan was reproducible to within 2.1% over the eight phases, though the lung volume changed by 20% between end inspiration and end expiration (870 cm3). 4D CT can be used for 4D radiotherapy, respiration-gated radiotherapy, 'slow' CT acquisition and tumour motion studies.

Humans↗
PubMed2003

[PSA and anthropometric measurements among Amazon Indians: an evaluation of the Parkatejê community].

OBJECTIVE: PSA (prostate-specific antigen) screening for early detection of prostate cancer in a native community is of great epidemiological importance. The study was conducted with the objective of verifying the occurrence of prostate cancer among members of an Amazon community, as well as its possible relationship to acculturation and overweight (body mass index). METHODS: Lifestyle and anthropometric information was collected from a group of 22 men, presumedly over age 50, members of an isolated community of 363 Amazonian Indians--self-denominated Parkatejê and Kykatêjê--from Pará state, in Northern Brazil. In addition to physical and hematological exams, total and free PSA dosages were performed. RESULTS: Total PSA serum levels ranged from 0.35 to 25.8 ng/ml. Three subjects had PSA levels greater than 4.0 ng/ml, and another two had levels between 2.5 and 4.0 ng/ml. Prostate biopsies performed on two subjects indicated the presence of prostate adenocarcinoma in one of them and of intraepithelial neoplasia on the other. Overweight (BMI> or =25 Kg/m2) and waist-to-hip ratio > or =0.9 were observed in 68.1% and 72% of subjects, respectively. CONCLUSIONS: Changes in nutritional habits caused by contact with civilization, such as the substitution of more caloric foods for the traditional game and vegetable fiber are increasing the prevalence of overweight among the community. In view of the association between prostate cancer incidence, high-fat diet, and less physical activity, it can be assumed that further cases of prostate neoplasia will occur in the future, since several community members already have high PSA serum levels.

Adenocarcinoma↗
PubMed2003

Diagnostic value of symptoms in patients with suspected upper digestive tract disease.

OBJECTIVE: to develop a predictive model based on clinical data for patients with suspected upper digestive tract disease. PATIENTS AND METHODS: forty-seven clinical data were obtained before endoscopy from 283 patients with suspected upper digestive disease (153 men; mean age 55 years, limits 17-92 years). A clinical prediction of diagnosis was made before endoscopy. On the basis of the endoscopic findings, the patients were divided into three diagnostic groups: absence of significant disease (group I), significant benign disease (group II) and malignant disease (group III). The probability rate of belonging to each one of the three groups was obtained for each patient by using Bayes' theorem. RESULTS: the endoscopic findings were classified according to their clinical importance: 121 patients (43%) belonged to group I, 137 (48%) were included in group II; and 25 (9%) in group III. The clinical prediction correctly classified 61% of the patients (group I: 56%, group II: 62% and group III: 76%) The coincidence between prediction obtained using Bayes' theorem and the actual diagnosis was 61% (group I: 65%, group II: 51%, group III: 92%). The predictive model was useful to confirm or not the clinical prediction. CONCLUSION: objective analysis of clinical data can be useful to support clinical judgment, mainly in patients with neoplasia. However, the model is not adequate to improve indication of upper endoscopy since many patients are misclassified.

Adolescent↗
PubMed2001

Culture and psychopharmacology.

In this brief review the authors strive to provide a broad overview of various factors that impinge on psychopharmacotherapeutic practices. The literature revealed an impressive progress in research focusing on the delineation of the biologic mechanisms responsible for cross-ethnic variations in psychotropic metabolism and effects. With the field progressing at an accelerating pace, there is little doubt that in the coming decade clinicians will be provided with a detailed map showing the prevalence and distribution of genetic polymorphisms of most, if not all, of the drug-metabolizing enzymes, and clinicians also will have an overall picture on what these polymorphisms mean clinically. At the same time, clinicians should also start to have a good grasp on the meaning of the variations of the genes that encode therapeutic targets of psychotropics (e.g., neurotransmitter transporters and receptors). Such genetic fingerprinting, which will soon become a clinical reality, will provide tremendous help in ensuring that pharmacotherapies are increasingly more individually tailored, taking into consideration each patients genetic makeups that vary substantially across ethnic groups. As exciting as these new developments will be, they are dwarfed by the challenges ahead on the cultural side of the equation. Issues that are still awaiting further clarification include the following: How do we assess patients' beliefs and expectations related to psychotropic treatment? How do we minimize the communication gaps between patients and clinicians who are often from divergent sociocultural backgrounds? To what extent, and in what ways, do cultural (environmental) factors interact with biologic factors, and what might be the most efficient way to systematically assess such interactions? Data that have emerged in the past several decades clearly indicate the importance of culture and ethnicity in influencing patients' psychopharmacological response. It is expected that continuing progress in the near future will bring a better understanding on the way these cultural and biologic processes, separately and in interaction with each other, mediate treatment responses. Such knowledge will be crucial for the optimal pharmacotherapeutic care of for the majority of patients who will increasingly be of diverse ethnic and cultural backgrounds and will represent a significant contribution to the field of psychopharmacology as a whole.

Cross-Cultural Comparison↗
PubMed2001

Are posttransplantation protocol liver biopsies useful in the long term?

Controversy exists about the usefulness of yearly protocol liver biopsies after liver transplantation, mainly among patients with normal transaminase levels. The aim of this study is to determine (1) the prevalence and cause of histological liver injury in transplant recipients with a minimum histological follow-up of 1 year (n = 254), and (2) the correlation between histological findings and transaminase values. The main indication for liver transplantation was viral-related cirrhosis (61%; 86% caused by hepatitis C virus [HCV]). Protocol liver biopsies were performed yearly for the first 5 years in HCV-infected transplant recipients and at 1 and 5 years in the remaining patients. Histological liver injury included several categories of liver damage (hepatitis, rejection, steatohepatitis, cholangitis, and Budd-Chiari-like lesions). Among biopsy specimens categorized as hepatitis, severe hepatitis was defined as the presence of stage 3 or greater fibrosis. The prevalence of liver injury increased significantly with time (42% v 56% at 1 and 5 years, respectively; P =.09) and was significantly greater in patients who underwent transplantation for HCV-related cirrhosis than in those who underwent transplantation for other reasons (P =.0001). The most frequent category of liver injury was hepatitis (97% and 96% at 1 and 5 years, respectively). Although a proportion of patients with liver injury (12% to 29%) had normal transaminase values, this percentage was almost null in patients with severe hepatitis. Normal histological characteristics were found in the vast majority of non-HCV-infected transplant recipients with normal transaminase values. Given the high prevalence of abnormal histological findings, particularly the increase over time of those defined as severe, protocol liver biopsies are clearly justified in HCV-infected transplant recipients. Conversely, given the rarity of abnormal histological findings, protocol liver biopsies should be questioned in non-HCV-infected transplant recipients with normal transaminase values.

Adult↗
PubMed2001

Gastrocystoplasty and chronic renal failure: an acid-base metabolism study.

PURPOSE: To verify in an experimental model whether gastrocystoplasty may protect patients with chronic renal failure from acid loading associated acidosis a wedge-shaped portion of the middle stomach was used to improve bladder capacity in animals with chronic renal failure. MATERIALS AND METHODS: An experimental model was used to study 112 adult female Wistar rats (EPM-1) weighing between 156 and 259 gm. The animals were randomly assigned to groups, including 41 controls, 24 undergoing five-sixths nephrectomy to create chronic renal failure, 26 undergoing gastrocystoplasty and 21 undergoing gastrocystoplasty and five-sixths nephrectomy to create renal failure. To provide an acid overload a 5% NH(4)Cl diet was administered to a subgroup of each group. Two months after surgery 24-hour urine was collected, and volume and pH were measured as well as the amount of bicarbonate, ammonium, titratable acidity and chloride. The animals were then exsanguinated through an abdominal aorta puncture. The blood was used for blood gas analysis and to measure sodium, potassium, chloride, ionized calcium and creatinine. RESULTS: When undergoing an acid overload, the animals with gastrocystoplasty had no acidosis since acid radicals were eliminating in the urine as NH(4)Cl. When given the same acid overload, metabolic acidosis developed in the animals with gastrocystoplasty and chronic renal failure. CONCLUSIONS: Gastrocystoplasty protected healthy rats from acidosis when they were given an acid overload but failed to protect the rats with chronic renal failure under the same conditions.

Acid-Base Equilibrium↗
PubMed2001

Scintigraphy and Doppler ultrasonography for the evaluation of obstructive urinary calculi.

Forty-seven patients with unilateral obstructive calculi (12 males and 35 females) were submitted to 99mTc-diethylene triamine pentaacetic acid (DTPA) or 99mTc-dimercaptosuccinic acid (DMSA) scans for assessment of renal function. The scans revealed unilateral functional deficit in 68 and 66% of the patients, respectively. A calculus size of 1.1 to 2.0 cm was significantly associated with deficit detected by DTPA, but duration of obstruction and calculus localization were not. After relief of the obstruction, the mean percent renal function of the affected kidney was found to be significantly increased from 25 +/- 12% to 29 +/- 12% in DTPA and from 21 +/- 15% to 24 +/- 12% in DMSA. Initial Doppler ultrasonography performed in 35 patients detected an increased resistive index in 10 (29%). In the remaining patients with a normal resistive index, ureteral urinary jet was observed, indicating partial obstruction. The high frequency of renal function impairment detected by DTPA and of tubulointerstitial damage detected by DMSA as well as the slight amelioration of unilateral renal function after relief of obstruction suggest that scintigraphy assessment may help evaluate the unilateral percentage of renal function and monitor renal function recovery when it occurs. The presence of a urinary jet detected by Doppler ultrasonography further indicates the severity of obstruction and the recovery prognosis.

Adult↗
PubMed2000

Achilles tendinitis as the presentation form of Löfgren's syndrome.

Löfgren's syndrome is characterised by bilateral hilar adenopathy arthritis and erythema nodosum. Achilles tendinitis as the presentation form of Löfgren's syndrome is very unusual. Herein we present a case of bilateral achilles tendinitis as the presentation form of Löfgren's syndrome.

Achilles Tendon↗
PubMed2000

Gastrinaemia and G-cell density in the antral gastrocystoplasty: an experimental study in rats.

OBJECTIVE: To evaluate gastrinaemia and G-cell density in the antrum incorporated into the bladder of rats after antrocystoplasty. Materials and methods Thirty-two adult, female Wistar EPM-1 rats (body weight 200-220 g) were divided into four equal groups that underwent; group 1, no treatment (controls); group 2, a sham operation; group 3, antrectomy; and group 4, antrocystoplasty. The rats were assessed 2 months after treatment, and gastrinaemia and the G-cell density determined in the antrum mucosa incorporated into the bladder. RESULTS: Compared with group 1, serum gastrin was significantly lower in group 3 (P<0.05) and the G-cell density lower in group 4 (P<0.05), although there was no decrease in gastrinaemia in group 4. CONCLUSION: Antrocystoplasty in rats did not affect gastrinaemia but reduced the number of G cells in the antrum incorporated into the bladder.

Anastomosis, Surgical↗
PubMed2000

Natural history of clinically compensated hepatitis C virus-related graft cirrhosis after liver transplantation.

The natural history of clinically compensated hepatitis C virus (HCV) cirrhosis after liver transplantation is unknown. This information is relevant to transplant centers to improve the management of these patients and decide the optimal timing for retransplantation. The aims of the study were (1) to describe the natural history of patients with HCV-cirrhosis transplants in a center with annual liver biopsies, and (2) to determine predictors for clinical decompensation, retransplantation, and mortality rates. A total of 49 patients with HCV-graft cirrhosis, 39 clinically compensated at histologic diagnosis of cirrhosis (post-liver transplantation cirrhosis) were included and followed up for 1 year (15 days-3.5 years). All patients tested were infected with genotype 1b. Predictive variables included histologic activity index (HAI) at post-liver transplantation cirrhosis, liver function tests, age, sex, and maintenance immunosuppression. Eighteen of 39 patients developed at least 1 episode of decompensation after a median of 7.8 months (4 days-2.6 years; 93% ascites). The cumulative probability of decompensation was 8%, 17%, and 42% at 1, 6, and 12 months, respectively. Graft and patient survival rates were 100%, 85%, and 71% and 100%, 92%, and 74% at 1, 6, and 12 months, respectively. Patient survival rates dropped significantly once decompensation developed (93%, 61%, and 41% at 1, 6, and 12 months, respectively). Variables associated with decompensation, retransplantation, and mortality rate included a high Child-Pugh score (>A), low levels of albumin at post-liver transplantation cirrhosis, and a short interval between liver transplantation and post-liver transplantation cirrhosis. The natural history of clinically compensated HCV-graft cirrhosis is shortened when compared with immunocompetent patients. If retransplantation is considered, it should be performed promptly once decompensation develops.

Adult↗
PubMed2000

[Comparative analysis of viral load by bDNA HCV RNA-2.0 and amplicor HCV monitor in patients with hepatitis C infection].

BACKGROUND: Two standardized techniques, Quantiplex (bDNA-2.0) and Amplicor Monitor have been evaluated for the quantification of virus load of HCV with these objectives: a) determinate the relationship between virus load and genotype, and b) evaluate the virus load in serial serum samples and in patients with normal or slightly increased liver enzymes in an area with a high prevalence of genotype 1. RESULTS: A significant correlation of 0.7 (p < 0.0001) in virus load has been observed by both methods, but the virus load is smaller by Monitor than by Quantiplex and does not depend on genotype. The relationship Monitor/Quantiplex is smaller in patients with non-1 genotype than in patients with genotype 1a (p = 0.01) and 1b (p = 0.005). Virus characteristics are similar in patients with normal or slightly increased enzymes than in patients with high enzymes. Virus load by both methods is not related to the age, sex, know duration of the infection, transmission manner of the infection neither to the histologic activity index. CONCLUSION: The virus load not depends on genotype. The determination of virus load in a single serum sample adequately reflects the virus load are in several serum samples in patients with chronic HCV infection. The genotype and the virus load are similar in patients with normal enzymes than in patients with high enzymes.

Adult↗
PubMed2000

[Cyclosporin in an oral microemulsion as the initial treatment of corticoid-refractory ulcerative colitis].

AIM: To assess the efficacy of oral microemulsion cyclosporin as the initial treatment of active ulcerative colitis refractory to steroid therapy. PATIENTS AND METHODS: The evolution of five patients treated with a dose of 5 mg/kg/day was analyzed. RESULTS: Oral microemulsion cyclosporin controlled acute attacks of the disease and led to remission during the 3 months of treatment in four of the five patients. Average hospital stay was 5.5 days. CONCLUSIONS: Oral microemulsion cyclosporin is an effective treatment in ulcerative colitis. Its administration is simple, the use of venous catheters is avoided and it may reduce mean hospital stay.

Administration, Oral↗
PubMed2000

[Comparison of the efficacy of cleaning and disinfection of videoscopes: mechanized versus manual].

AIM: a) To analyze the effectiveness of the automated cleaning and disinfection of endoscopies (Olympus miniETD, not previously tested) versus the manual method; b) To evaluate the drying and storage procedures used in our unit. MATERIAL AND METHODS: Prospective 10-day study. The endoscopies were randomized for automated or manual cleaning and disinfection. Endoscopic samples were collected for microbiology studies at three points during the process: a) after endoscopy (after manual cleaning with water), b) after cleaning with enzymatic detergent and disinfection (automated or manual) and c) at the first hour in the morning. RESULTS: Sixty-five samples were collected after endoscopy: 26 from gastroscopy, 26 from colonoscopy and 13 from duodenoscopy (positive cultures were found in 22, 25 and 10, respectively). The 35 samples collected after automated disinfection were negative, as were 29 of the 30 collected after manual disinfection (p = 0.46). Sixty-four of the 65 samples were negative for hepatitis B and hepatitis C. The only sample positive for hepatitis C became negative after manual disinfection. Positive culture was found in 15% of the samples collected before beginning the session. CONCLUSIONS: a) Automated cleaning and disinfection (Olympus miniETD) are as effective as manual cleaning. b) Drying and storage procedures should be improved and/or disinfection should be carried out again before the first endoscopy of each session.

Colonoscopes↗