PubMed Health⌕ Search

Biomedical subjects

S Vázquez

Publications and source records attributed to S Vázquez.

At least 19 recordsLinked to original sources
PubMed2006

Kinetics of antibodies in sera, saliva, and urine samples from adult patients with primary or secondary dengue 3 virus infections.

OBJECTIVES: The kinetics of three serological markers (IgM, IgA, and IgG) in serum, saliva, and urine samples from adult patients with primary or secondary dengue infection were studied. DESIGN: Serum, saliva, and urine samples were collected from 22 patients with clinical and confirmed dengue 3 virus infection during the outbreak in Havana City in 2001. They were tested by capture IgM (MAC-ELISA), IgA (AAC-ELISA), and IgE (EAC-ELISA) and IgG ELISA inhibition method (EIM) to detect specific dengue antibodies. RESULTS: Similar kinetics were observed in IgM, IgA, and IgG antibodies in saliva and IgA and IgG in urine samples from secondary cases compared with kinetics in serum samples, although the values were lower. No IgG antibody was detected in saliva and urine samples in primary cases and IgM antibody was not detected in urine samples from either primary or secondary infection. All secondary cases were positive for IgG in saliva and urine samples at day 7. The kinetics of specific IgE antibodies in primary and secondary cases were different. CONCLUSIONS: The kinetics of three serological markers (IgM, IgA, and IgG) in serum, saliva, and urine samples from adult patients with primary or secondary dengue 3 virus infection were studied for the first time, showing its behavior and usefulness in dengue virus diagnosis. The specific IgE could play a role as a serological marker in secondary infections.

Adult↗
PubMed2006

Risk factors associated with Enteromyxum scophthalmi (Myxozoa) infection in cultured turbot, Scophthalmus maximus (L.).

An epidemiological cohort study of Enteromyxum scophthalmi in cultured turbot was performed on a farm in North Western Spain. Four different ongrowing stocks (A, B, C, D) were monitored monthly until market size. Fish from stocks C and D were divided into 2 subgroups, receiving filtered (CF and DF) or unfiltered (CUF and DUF) water. The lack of water filtration was positively associated with infection prevalence, as all fish kept in filtered water remained uninfected. Parasite abundance varied seasonally (P<0.05) in stock B and subgroup CUF. Infection was also associated (P<0.05) with host weight, and the highest prevalences and intensities were detected in 101-200 g and 201-300 g fish. Distribution pattern of E. scophthalmi in subgroups CUF and DUF had a variance higher than the mean, indicating overdispersion. The minimum period necessary for the first detection of the parasite and for the appearance of disease symptoms and mortality, varied depending on the stock and introduction date, although a long pre-patent period was always observed. Several factors, such as host density, parasite recruitment and parasite-induced fish mortality can contribute to the observed distribution pattern. Risk factors found to be associated with E. scophthalmi infection, including water quality and accumulation of infective stages in the culture tanks, should be considered when designing control strategies to prevent the introduction and spread of infective stages in the facilities.

Animals↗
PubMed2006

EBLV1 circulation in natural bat colonies of Eptesicus serotinus: a six year survey.

The serotine bat (Eptesicus serotinus) accounts for 95 % of cases of human exposition to EBLV1. The aim of this study was to focus on the epidemiology and pathogenesis of EBLV1 infection in the serotine bat. Our first objective was the development of an RT-PCR technique for the specific detection of EBLV1 RNA in oro-pharyngeal swabs. This technique showed better performance than the classical immunofluorescence (IF) on brain in detecting EBLV1 in healthy flying bats. We have used this technique together with antibody detection by the fluorescent focus inhibition test (FFIT) to investigate EBLV1 circulation in 19 natural colonies of serotine bats in Andalusia (Spain) from 1998 to 2003. The survey was based on 1223 different captures of 1080 individuals that were ring banded, sampled and released. Individuals that were repeatedly captured were always found in the same colony even though some colonies were less than five Km apart. Viral circulation was detected in nine colonies either by RT-PCR, serology or both. Each colony showed a different temporal pattern of viral circulation suggesting independent endemic circulation. Some positive individuals were captured healthy in following campaigns evidencing survival after viral infection.

Animals↗
PubMed2005

Recurrence of IgA nephropathy and Henoch-Schönlein purpura after kidney transplantation: risk factors and graft survival.

BACKGROUND: IgA nephropathy (IgA) is one of the most common glomerulonephritis. Renal transplantation is the treatment of choice for patients with ESRD due to any kind of glomerulopathy, including IgA and Henoch-Schönlein purpura nephritis (H-SP), but original disease recurrence is now the third most frequent cause of allograft loss. METHODS: Eighty-seven cases of glomerulonephritis as the original disease were divided in two groups: group A--37 affected with 31 IgA and 6 H-SP; and group B--50 with other glomerulopathies. We compared patient and graft survivals at 5 years. To assess the presence of IgA or H-SP recurrence in group A patients, we performed an allograft biopsy in the presence of microhematuria, proteinuria, or an increased plasma creatinine. Known risk factors influencing recurrence rate were also analyzed. RESULTS: Five-year patient (97% vs 95%) and graft survivals (81% vs 78%) were not significantly different between groups A and B. Patients with crescentic glomerulonephritis (CGN) at the moment of diagnosis of IgA or H-SP showed a 5-year graft survival of 71% in contrast with 100% graft survival among those with mesangial or focal and segmental glomerulosclerosis pattern (P = .03). Histological recurrence was diagnosed in eight patients: six IgA and two H-SP. Women (P = .013) and a good HLA match (P = .029) were significantly associated with the risk of recurrence. CONCLUSIONS: When compared with other glomerulonephritis patients, with IgA or S-HP showed similar 5-year graft and patient survivals. Nevertheless, graft survival was shorter among patients with crescentic glomerulonephritis at the moment of diagnosis. Thus, the disease prognosis after grafting may be linked to the initial histological aggressiveness. Women and those patients transplanted with a good HLA match were prone to develop disease recurrence with a tendency toward a lower 5-year graft survival.

Adult↗
PubMed2004

Serological markers during dengue 3 primary and secondary infections.

BACKGROUND: The detection of the IgM antibody for the dengue virus in serum by ELISA has become one of the most important and useful methods for diagnosis of dengue using a single acute-phase serum sample. Currently, this system is an invaluable tool for the surveillance of dengue fever (DF) and dengue hemorrhagic fever (DHF). The usefulness of other serological markers such as IgA and IgE have been less studied. OBJECTIVE: To study the IgM, IgA and IgE specific antibody response in dengue 3 infected patients with different clinical picture and type of infection. STUDY DESIGN: One hundred and twenty-seven serum samples collected on days 5-7 at the onset of fever from clinically and serologically confirmed dengue cases were studied. Forty-two were classified as primary dengue fever cases, 48 as secondary dengue fever cases and 37 as secondary dengue hemorrhagic fever cases. All samples were tested by capture ELISA in order to detect dengue IgM, IgA and IgE antibodies. RESULTS AND CONCLUSIONS: In this study, significant differences were observed in the IgM, IgA and IgE response between the study groups. High IgA and IgE OD ratios in secondary dengue cases were found. The usefulness of serotype specific IgM antibody detection is also analyzed and discussed. A priority for future dengue research in terms of protection, recovery of infection and immunopathogenesis is to elucidate the role of these immunoglobulins. The cross reactivity response to IgM between dengue virus serotypes in primary and secondary cases should also be more studied.

Antibodies, Viral↗
PubMed2004

Cryptosporidium scophthalmi n. sp. (Apicomplexa: Cryptosporidiidae) from cultured turbot Scophthalmus maximus. Light and electron microscope description and histopathological study.

Cryptosporidium scophthalmi n. sp. is described from the turbot Scophthalmus maximus L., sampled from different farms on the coast of NW Spain. The parasite was found mainly in the intestinal epithelium and very seldom in the stomach. Oocysts were almost spherical, with 4 naked sporozoites and a residuum, and measured 3.7-5.03 x 3.03-4.69 microm (mean 4.44 x 3.91) (shape index 1.05-1.34, mean 1.14). Sporulation was endogenous, as fully sporulated oocysts were found within the intestinal epithelium, lumen and faeces. Merogonial and gamogonial stages were in the typical extracytoplasmic position, whereas sporogonial stages were deep within the epithelium. Oocysts and other stages of C. scophthalmi comply with most of the diagnostic features of the genus Cryptosporidium, but differ from all hitherto described species. Ultrastructural features, including the characteristic feeding organelle, were mainly comparable with those of other Cryptosporidium species. Mitochondria were frequently observed in sporozoites. Infection prevalence was very variable, and juvenile fish were most frequently and intensively parasitised. External clinical signs were not detected, although some fish showed intestinal distension at necropsy. The marked histopathological damage occurring in severe infection includes distension of epithelial cells by large vacuoles, containing clusters of oocysts, and can lead to sloughing of epithelial cell remnants and oocysts or even detachment of intestinal mucosa. An inflammatory reaction involving leucocyte infiltration was sometimes observed.

Analysis of Variance↗
PubMed2004

Ambulatory blood pressure monitoring in renal transplant patients: modifiable parameters after active antihypertensive treatment.

BACKGROUND: Hypertension (HT) accounts for nearly 60% to 80% of renal transplant patients (RT). It is one of the most important risk factors for cardiovascular diseases and may cause chronic graft dysfunction. Therefore, it is important to accurately detect and treat HT. We aimed to evaluate the changes in ambulatory blood pressure monitoring (ABPM) parameters among hypertensive RT after active treatment compared with baseline values. METHODS: Thirty seven RT (25 men, 12 women, aged 49.4 +/- 11.2 year) diagnosed with mild to moderate HT underwent 24-hour ABPM after a 4-week washout period (W0). For the 23 RT with confirmed HT of a second 24-hour ABPM was recorded after 4 weeks of treatment with doxazosin GITS (-4 mg once daily in the morning), a new formulation of an alpha1-receptor inhibitor (W4). Nondippers were considered when mean blood pressure (BP) showed a < or = 10% reduction during sleep. Statistical analyses included Saphiro-Wilks test, Student t test, and ANOVA. RESULTS: After active treatment systolic, diastolic, and mean BP (SBP, DBP, MBP) significantly decreased during diurnal and 24 hours but not the nocturnal period. No significant change was observed for heart rate nor for pulse pressure during any period. The prevalence dippers increased from 0% to 17% after treatment. After placebo administration 8 among 37 RT with HT diagnosed according to casual BP remained hypertensive at nighttime (but not at daytime) according to 24-hour ABPM. CONCLUSIONS: Diurnal and 24-hour periods of ABPM showed significant changes in SBP, DBP, and MBP after active treatment with doxazosin GITS. No significant BP changes were observed in the nocturnal period or in dipper status. Further studies using ABPM must be undertaken to determine the optimal dosage and time of administration of antihypertensive drugs in RT.

Antihypertensive Agents↗
PubMed2003

Efficacy and safety of doxazosin GITS in hypertensive renal transplant patients: comparison of 8 and 4 mg.

BACKGROUND: Hypertension (HT), a prevalent complication in renal transplant patient (RT), must be accurately treated because cardiovascular disease is the leading cause of death and of chronic graft dysfunction. Sympathetic activity may contribute to HT in RT, yielding the rationale to suspect that doxazosin, an alpha1-adrenergic receptor inhibitor, may lower blood pressure (BP). The aim of this study was to evaluate the efficacy and safety of doxazosin GITS (4 and 8 mg) in RT. METHODS: Twenty-three hypertensive RT received doxazosin 4 mg once daily for 4 weeks (W4) followed by a 4-week washout (W0) and 17/23 treated with doxazosin 8 mg for 4 more weeks (W8) due to persistent HT. All patients underwent 24-hour ambulatory blood pressure monitoring (ABPM) after W0, W4, and W8. Laboratory tests were performed, adverse events recorded, and prostatic symptomatology examined. Statistical analysis included Saphiro-Wilks, Student t, ANOVA, Wilcoxon, or Friedman tests. RESULTS: The systolic, diastolic, and mean BP were significantly lowered at W4 in awake (P<.001) and 24 hour period (P<.005) but not sleep recordings. Doxazosin 8 mg had no significant additional effect to lower BP at any period. Normotension was reached in 13% and 21.7% of patients at W4 and W8, respectively. Palpitations were the only reported adverse event after treatment (incidence similar to placebo). There was no significant change in the laboratory values. CONCLUSIONS: Doxazosin (-4 mg) effectively decreased BP in awake and 24-hour periods without a significant improvement during sleep. A double dose of the drug added little benefit. Optimal BP was reached by an insufficient number of patients. Doxazosin proved to have a good tolerance and safe profile. This results suggest that doxazosin should be considered a good add-on treatment to other antihypertensive drugs in RT.

Adrenergic alpha-Antagonists↗
PubMed2001

Induction and inhibition of apoptosis by pseudorabies virus in the trigeminal ganglion during acute infection of swine.

We examined the ability of pseudorabies virus (PRV) to induce and suppress apoptosis in the trigeminal ganglion during acute infection of its natural host. Eight pigs were intranasally inoculated with a virulent field strain of PRV, and at various early times after inoculation, the trigeminal ganglia were assessed histologically. PRV-infected cells were detected by use of immunohistochemistry and in situ hybridization, and apoptosis was identified by in situ terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling. Light and electron microscopy was also used for morphological studies. Apoptosis was readily detected among infiltrating immune cells that were located surrounding PRV-infected neurons. The majority of PRV-infected neurons did not show morphological or histochemical evidence of apoptosis, even including those neurons that were surrounded by numerous inflammatory cells and exhibited profound pathological changes. However, neuronal virus-induced apoptosis also occurred but at a sporadic low level. These findings suggest that PRV is able to block apoptosis of infected trigeminal ganglionic neurons during acute infection of swine. Furthermore, our results also suggest that apoptosis of infiltrating inflammatory cells may represent an important viral mechanism of immune evasion.

Acute Disease↗
PubMed2001

Complications of thoracentesis in cirrhotic patients with pleural effusion.

OBJECTIVE: To study the complications of thoracentesis, either diagnostic or therapeutic, in cirrhotic patients with pleural effusion. EXPERIMENTAL DESIGN: A cohort prospective study. A diagnostic thoracentesis was performed at admission or when spontaneous bacterial empyema was suspected; a therapeutic thoracentesis was conducted in patients with dyspnea that did not improve with medical treatment. A chest radiography and a careful clinical follow up were performed in all patients within 24 hours after the procedure. We studied the risk factors for developing pneumothorax and the actuarial probability of pneumothorax after consecutive therapeutic thoracentesis. PATIENTS: All cirrhotic patients admitted with pleural effusion over a 4-year period. The study included 69 patients. RESULTS: During the study period, we performed 245 thoracentesis, 150 diagnostic and 95 therapeutic ones. The most severe complication was pneumothorax in 10 cases (4%), after 2 out of 150 (1.3%) diagnostic thoracentesis and after 8 out of 95 (8.4%) therapeutic thoracentesis (RR, 95% CI 6.8, 1.41-32.77, p < 0.01). The actuarial risk of pneumothorax after the first, second and fourth therapeutic thoracentesis was 7.7%, 25.3% and 34.7%, respectively. CONCLUSIONS: Diagnostic thoracentesis in cirrhotic patients is associated to a low morbidity. Therapeutic thoracentesis is a risk factor for pneumothorax and the risk increases after consecutive thoracentesis. A chest radiograph is not justified after a diagnostic thoracentesis, but should be done after a therapeutic thoracentesis.

Female↗
PubMed2000

Human Dengue antibodies against structural and nonstructural proteins.

Antibodies against dengue virus type 2 and 4 proteins in acute-phase sera of 10 primary and 10 secondary dengue fever and dengue hemorrhagic fever patients were studied by Western blotting. In the first group the immune response was barely detectable, while in the second group more proteins were detected, with a very strong reaction. Anti-NS1 and -NS3 antibodies were detected mainly in secondary cases. Anti-E, -NS3, and -NS5 antibodies were detected in a high number of cases. The possibility of implementing early diagnostic assays for antigen detection is suggested.

Animals↗
PubMed1999

Fatal dengue hemorrhagic fever in Cuba, 1997.

OBJECTIVES: After more than 15 years without dengue activity, a dengue II epidemic was reported in Cuba in 1997. Three thousand and twelve serologically confirmed cases were reported, with 205 dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) cases and 12 fatalities. This report presents the clinical, serologic, and virologic findings in the 12 fatal DHF/DSS cases. METHODS: Serum and necropsy samples were studied by viral isolation in C636 cell line and polymerase chain reaction. Serum samples were tested by IgM capture enzyme-linked immunoassay (ELISA) and ELISA inhibition method (EIM). RESULTS: All 12 cases were classified as DHF/DSS according to the Pan American Health Organization Guidelines for Control and Prevention of Dengue and Dengue Hemorrhagic Fever in the Americas. All patients were older than 15 years. Women were more frequently affected. The symptoms and signs presented by these patients were similar to those previously described in DHF/DSS cases. Clinical deterioration occurred on average at day 3.75. Abdominal pain and persistent vomiting were the earliest and most frequent warning signs. Dengue infection was confirmed in all cases. IgM antibodies were detected in 11 of 12 cases, all of them with a secondary infection. Dengue II virus was detected by viral isolation in 12 samples and by polymerase chain reaction in 17. Virus or RNA was detected in various tissues, including kidney, heart, lung, and brain. CONCLUSION: The clinical, pathologic, and laboratory features of 12 cases of fatal dengue hemorrhagic fever were reviewed. The results obtained demonstrate that adults with a primary dengue infection are at risk of developing the severe disease (DHF) if they are infected with a different serotype.

Adolescent↗
PubMed1999

[Epidemiology of dengue and hemorrhagic dengue in Santiago, Cuba 1997].

A dengue epidemic that Cuba reported in 1997 registered more than 500,000 cases of dengue fever produced by viral serotype 1. In 1981, there was an epidemic of dengue hemorrhagic fever produced by serotype 2 of the virus. This time 344,203 clinical cases were reported, 10,312 of which were severe cases of hemorrhagic fever that led to 158 fatalities (101 of them among children). The reintroduction of dengue, and specifically of dengue viral serotype 2 (Jamaica genotype), was quickly detected in January 1997 through an active surveillance system with laboratory confirmation of cases in the municipality of Santiago de Cuba, in the province of the same name. The main epidemiological features of this outbreak are reported in this paper. A total of 3,012 cases were reported and serologically confirmed. These included 205 cases classified as dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS), 12 of which were case fatalities (all among adults). Secondary infection with dengue virus was one of the most important risk factors for DHF/DSS. Ninety-eight percent of the DHF/DSS cases and 92% of the fatal cases had contracted a secondary infection. It was the first time dengue hemorrhagic fever was documented as a secondary infection 16 to 20 years after initial infection. Belonging to the white racial group was another important risk factor for DHF/DSS, as had been observed during the 1981 epidemic. During the most recent epidemic it was demonstrated that the so called "fever alert" is not useful for early detection of an epidemic. Measures taken by the country's public health officials prevented spread of the epidemic to other municipalities plagued by Aedes aegypti.

Adolescent↗
PubMed1998

[Detection of IgM against the dengue++ virus in whole blood absorbed on filter paper].

This paper presents a standardized procedure for the detection of IgM antibodies to dengue virus in blood samples taken from filter paper. The samples were obtained from 118 patients, of whom 91 had been clinically diagnosed with dengue and 27 with a viral infection unrelated to that disease. The first group of patients came from Costa Rica and Nicaragua and the second group from Cuba. All the samples were tested for IgM antibody against dengue virus by means of a capture enzyme immunoassay (EIA). Analysis of the results for patients from all three countries together yielded a sensitivity of 98.1% and a specificity of 98.5% for the test done on whole blood on filter paper stored at 4 degrees C; agreement between the results of that test and those of the EIA using serum samples was 96%. In a comparison of the results obtained with three samples from the same patient--whole blood on filter paper stored at room temperature, the same type of sample stored at 4 degrees C, and serum--the agreement was 86%. This study demonstrates the high diagnostic sensitivity and specificity achieved when whole blood absorbed on filter paper is processed in the manner described in detail in the article. The authors recommend the use of this method in the dengue surveillance programs in the Region.

Dengue Virus↗
PubMed1998

[Polymerase chain reaction for rapid detection and serotyping of dengue virus in clinical samples].

This study describes the benefits of using reverse transcriptase polymerase chain reaction (RT-PCR) for the rapid detection and typing of dengue virus in clinical samples. Twenty-seven serum specimens from patients with dengue fever and dengue hemorrhagic fever in Colombia, Nicaragua, and Panama were directly subjected to RT-PCR for the detection of dengue virus. The resulting double-stranded DNA product was typed by a second round of PCR amplification (nested PCR) with type-specific primers, viral culture/indirect immunofluorescence (IIF), and enzyme-linked electroimmunoassay for IgM anti-dengue antibodies. The amplified virus genome was detected and typed within 8 hours. Nested RT-PCR, using viral culture and IIF as the gold standard, showed 100% sensitivity; 78% specificity; 69% positive predictive value, and 100% negative predictive value. It is noteworthy that two of the specimens whose results were positive with nested RT-PCR and negative with viral culture showed specific IgM antibodies. The results of the RT-PCR were in close agreement with those obtained through viral culture. This suggests PCR can greatly facilitate the rapid and early diagnosis of dengue infection.

Colombia↗