Biomedical subjects
J Vidal
Publications and source records attributed to J Vidal.
[Outbreak of measles at a vocational training school].
BACKGROUND: A measles outbreak which started in the technical institute Els Ports in Albocacer (Castellón), and involved nearby towns was studied. METHODS: The outbreak was described using a retrospective cohort study to estimate the efficacy of the antimeasles vaccination (EV) by a questionnaire distributed in the institute. Response rate was 80.7%. A clinical definition of measles was used with EV being calculated by 2 different formulas. Antimeasles vaccination coverage (VC) in primary schools of the towns involved was also assessed. RESULTS: The outbreak occurred from February to April 1992, including 13 cases of measles (mean age: 13.6 +/- 2.7 years). Eleven patients (84.6%) had not been vaccinated. The attack rate the above mentioned institute was 9.1% (8 cases/88 students) with VC of 40.9%. An association was found only between being vaccinated and not having measles, relative risk 0.07 (confidence limits [CL] 95%: 0.01-0.50). EV was 92.9% (CL 95%: 50-99%) using the traditional formula and 96.2% (CL 95%: 88.2-100%) using the new formula. The VC in the schools was 92.3%. Vaccination with the triple viral vaccine was recommended to susceptible individuals. CONCLUSIONS: Despite specific vaccination measles continues to produce epidemics. A second dose of the triple viral vaccine is recommended for being included in the vaccination calendar between the age of 6 and 14 years.
[The methods of preventive clinical medicine (I). Preventive immunizations and chemoprophylaxis].
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Production and properties of recombinant C3-type phosphoenolpyruvate carboxylase from Sorghum vulgare: in vitro phosphorylation by leaf and root PyrPC protein serine kinases.
In this work, the C3-type form of Sorghum phosphoenolpyruvate carboxylase (PyrPC) was produced in PyrPC-deficient strains of Escherichia coli transformed by a plasmid bearing the corresponding full-length cDNA (CPR1). The full-sized protein was purified to homogeneity by immunoaffinity chromatography. Some functional and regulatory properties were described; notably, the immunopurified PyrPC could be phosphorylated in reconstituted assay by 1) both a mammalian PKA and the PyrPC protein serine kinase purified from Sorghum leaves and 2) a novel protein kinase affinity-purified from Sorghum roots. In all cases phosphorylation was accompanied by a marked reduction in its malate sensitivity.
[The vaccination of medical and nursing students against hepatitis B].
BACKGROUND: Vaccination against the hepatitis B virus (HBV) of health care staff during their studies would have the advantage of early prevention when the prevalence of infection is presumably low. METHODS: The population to be protected is made up of 1533 medical and nursing students. In those who accepted, anti-HBc was determined and information was obtained concerning circumstances of exposure to HBV. Vaccination was offered to all the cases of negative anti-HBc. Individuals receiving 3 doses of the vaccination (20 micrograms at 0, 1 and 6 months) were seen at 4-7 months of the last dose to determine the anti-HBs titers achieved. RESULTS: One thousand sixty-five students (70%) accepted inclusion into the prevaccination anti-HBc study and 1,029 (3.4%) were anti-HBc negative. Only older age and previous transfusions and jaundice were significantly associated to greater prevalence of infection by HBV. The adherence to 1, 2 or 3 doses of the vaccination was 96%, 94% and 87%, respectively. Following the 3 doses, > or = 10 UI/I of anti-HBs were detected in 97% of the cases studied with geometric measurement of the responders being 1580 U/I. The titer had an inverse relation which was not significant with age. CONCLUSIONS: The high participation in the program of anti-hepatitis B vaccination and the excellent immune response observed leads to the recommendation of systemic vaccination to future health care professionals during their study period. Furthermore, the low prevalence of previous HBV infection advises against previous detection of anti-HBc with immunization of the whole collective being more effective.
Insulin, beta-cell rest, and high risk of type I diabetes mellitus.
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Is hepatitis C virus infection a trigger of porphyria cutanea tarda?
The causes of liver disease, ranging from fatty changes to cirrhosis and hepatocellular carcinoma, in porphyria cutanea tarda (PCT) remain unclear. We tested 100 consecutive PCT patients for antibodies to hepatitis C virus (HCV) by enzyme-linked immunosorbent assay and a recombinant immunoblot assay. 75 (79%) patients with sporadic PCT but none of 5 with familial PCT were positive. HCV RNA was found in serum of all 18 anti-HCV-positive patients tested. There were no significant differences in the prevalence of anti-HCV between treated and untreated patients or between those with and without various HCV risk factors. The frequency of anti-HCV increased with the severity of liver histology. These findings implicate HCV in the aetiology of PCT-associated liver disease.
Mechanical process and growth cartilages. Essential factors in the progression of scoliosis.
This study showed that the worsening of scoliosis was the result of a mechanical phenomenon. The key feature in this mechanical process was the finding that cuneal deformation affects only part of the vertebral body. The onset of scoliotic curvature occurred as a result of intervertebral motions. However, the worsening was essentially caused by deformation of the vertebral bodies. After the onset of scoliosis, the orientations of the vertebrae were modified in all three planes, and as a result, the spine became mechanically unstable. As a result of this mechanical instability, intervertebral pressures no longer were distributed equally but were concentrated at the junction of the growth cartilages of the vertebral body, near the pedicle on the concave side. Osseous growth was perturbed in this area, the vertebra became deformed, and the vertebral body became wedge shaped. These cuneal deformations resulted in a relative change of position between adjacent vertebral bodies and led to a worsening of the scoliotic curve without involving any articular motion. This phenomenon occurred mostly in the apical region because of the geometric shape of the curvature.
An engineered change in the L-malate sensitivity of a site-directed mutant of sorghum phosphoenolpyruvate carboxylase: the effect of sequential mutagenesis and S-carboxymethylation at position 8.
A recombinant, site-directed mutant form of sorghum phosphoenolpyruvate carboxylase (PEPC), in which the phosphorylatable serine residue (Ser-8) was changed to cysteine (S8C), was chemically modified by iodoacetic acid and iodoacetamide for the purpose of testing the effect of introducing a negative charge at position 8. S-Carboxymethylation of the Cys-8 enzyme by iodoacetic acid decreased its sensitivity to L-malate from an I0.5 (50% inhibition) value of 0.12 to 0.35 mM at pH 7.3 when the active-site domain was protected during modification by the substrate phosphoenolpyruvate (PEP). In contrast, neither S-carboxymethylation of the wild-type enzyme nor modification of the mutant enzyme by iodoacetamide caused any change in the enzyme's sensitivity to L-malate. The modified, substrate-protected forms of the Ser-8 and S8C PEPCs had Km(total PEP) and Vmax values virtually identical to those of the unmodified control enzymes. Similar specific increases in the I0.5 value of L-malate have been reported previously for in vitro phosphorylated leaf and recombinant Ser-8 PEPCs, the site-directed mutant Asp-8 enzyme, and C4-leaf PEPC purified from light-adapted sorghum or maize (in vivo phospho-form). Therefore, these data from different but complementary experimental approaches provide convincing evidence that the effect of phosphorylation of Ser-8 on the L-malate sensitivity of sorghum C4-PEPC is caused by the introduction of negative charge into this N-terminal regulatory domain.
Etiology of traveller's diarrhea in Spanish travellers to developing countries.
A cohort of 337 Spanish travellers to developing countries is presented. They all consulted us for traveller's diarrhea (TD). Bacteriological, parasitological and virological examinations were performed. A bacterial cause was found in 61.65% of travellers. Toxigenic and classical pathogenic Escherichia coli strains were the main bacterial agents. In comparison with other studies, Spanish travellers harboured Y. enterocolitica and EPEC organisms as a cause of TD. G. lamblia and E. histolytica were the most frequently isolated protozoa. Helminths were found in only 9 patients. No rotavirus infections were diagnosed. Previous antibiotic treatment had been taken by 161 patients. The percentage of isolated enteropathogens was similar in travellers who had previously taken antibiotic treatment and those who had not.
Hepatitis B vaccination in prisons: the Catalonian experience.
A pilot programme of hepatitis B vaccination was set up in three prisons to assess the feasibility and results of this method of reaching a high-risk population. Hepatitis B vaccine was offered to all inmates who lacked serological markers for hepatitis B virus. The antibody response was assessed in those who received two or three doses of vaccine. Candidates for vaccination were 41% of 1755 imprisoned men (20% of intravenous drug users (IVDU) and 63% of non-IVDU), but complete vaccination could be given to only 33% of candidates. A further 29% received two doses. Seroconversion to anti-HBs (titres > 10 IU l-1) occurred in 33% of vaccinees after two doses and in 76% after three doses. The overall rate of susceptible inmates who became protected for hepatitis B was 34%. The seroconversion rate was higher when the interval between the first two doses was shorter than 3 weeks (91%), than in cases with an interval of 3-6 weeks (79%) or longer than 6 weeks (33%). Age greater than 35 years and history of IVDU were associated with a lower response to the vaccine, while anti-HIV seropositivity did not influence the response. In conclusion, vaccination of prisoners susceptible to HBV may achieve protection in at least a third of cases. Shortening intervals between the priming doses of vaccine may improve compliance and increases the response.
Spinal cysticercosis. Case report and review.
Cysticercosis is the commonest parasitic disease to affect the central nervous system (CNS). According to the World Health Organisation (1988), more than 2.5 million people worldwide are infected. Neurocysticercosis (NCC) is caused by the encysted larval form (porcine tapeworm) of Taenia solium (Cysticerus cellulosae). The ways in which the eggs of T Solium penetrate the CNS are illustrated in Table I. Involvement of the spinal cord in NCC varies between 1% and 5%. The isolated medullary form is very rare, only 50 cases having been reported up to 1988. The appearance of a spinal cord compression syndrome (SCCS) is unusual and late, according to reported series, the largest being that of Sotelo with 753 cases of NCC, including 10 causing SCCS, corresponding to 1.4%; also the classic Dixon and Lipscomb series of 450 NCC with only one patient with SCCS.
Antibody response to rat erythrocytes and some behaviors in two strains of mice after social isolation.
The purpose of this research was twofold: (a) To find out if the antibody response and some behaviors are differential traits for mice (murine strains C57BL/6 and BALB/c); and (b) to study the influence of strain and isolation on both behavior and the antibody response. We used 21 C57BL/6 male mice and 28 BALB/c male mice; of these, 11 C57BL/6 and 16 BALB/c were kept isolated. The rest were housed 2 mice to a cage. We used three open-field tests (of varying light and sound stimulation), a holeboard test, and a light-darkness test. All the mice were immunized with rat erythrocytes. In addition, the mice were weighed. The traits that best differentiated both strains were weight, IgM primary response, and emotional behavior (behaviors in stimulating open fields). Social isolation (of adult mice) influenced emotional behavior, but not the antibody response.
Effects of isradipine and nifedipine retard in hypertensive patients with type II diabetes mellitus.
Twenty patients were randomized to receive either 2.5 mg isradipine twice daily or 20 mg nifedipine retard once daily for 6 months. After 2 weeks of placebo wash-out, evaluations were carried out every 4 weeks. These evaluations included assessment of blood pressure, lipid profile, hemoglobin A1 sigma glucagon, C peptide, and insulin requirements. Both isradipine and nifedipine retard lowered systolic and diastolic blood pressures to normal values (P < .001). However, isradipine was accompanied by a decrease in heart rate (P < .005). Neither drug modified hemoglobin A1c or the glycemic profile. The endogenous insulin-secretion response decreased in both treatment groups (P < .05). In conclusion, isradipine and nifedipine retard are efficacious in the treatment of hypertension in patients with type II diabetes mellitus, and neither treatment produces modification of metabolic control.
Five-day treatment of non-severe, community-acquired pneumonia with josamycin.
This study assessed the efficacy of oral josamycin 1 g bd for five days as treatment for non-severe, community-acquired pneumonia in patients less than 60 years of age who were not at obvious risk of developing respiratory tract infection caused by aerobic Gram-negative bacilli. Of the 84 patients (43 male, 41 female) with a mean age of 33 years who were enrolled during a 14-month period, the clinical outcome was invariably favourable. All patients became afebrile within three days of starting therapy; the mean duration of fever after initiating treatment was 1.7 days. Therefore, according to the study protocol, josamycin therapy was discontinued on day five. A chest X-ray performed four to six weeks after completing treatment was normal in every case and no relapses were observed during a six-week follow-up period. We conclude that a five-day course of josamycin is effective monotherapy for community-acquired pneumonia in patients without the clinical features of severe infection.
Comparison of patient and staff surveys of consumer satisfaction.
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Antibody response and some behaviors as differential traits between two inbred strains of mice (C57BL/6 and BALB/c).
The goals of this research were to find out if the antibody response and some behaviors are differential traits for murine strains C57BL/6 and BALB/c and to study the influence of strain and isolation on both behavior and the antibody response. 21 C57BL/6 male mice and 28 BALB/c male mice were used; of those, 11 C57BL/6 and 16 BALB/c were kept isolated, and the remaining mice were housed 2 per cage. The tests were Open-fields 1, 2, and 3 (of varying light and sound stimulation), holeboard, light-darkness test, immunization with rat erythrocytes; in addition, the mice were weighed. The traits that best differentiated both strains (according to discriminant analysis) were weight, IgM primary response, and emotional behavior (ambulation, rearing, and defecation in stimulating open-fields). Social isolation (of adult mice) influenced emotional behavior, but not the antibody response.