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Biomedical subjects

A Otero

Publications and source records attributed to A Otero.

At least 91 records · Page 5Linked to original sources
PubMed1996

Characterization and extracellular activity of psychrotrophic bacteria isolated from Villalón cheese (fresh variety of Spanish sheep's milk cheese).

The incidence of psychrotrophic bacteria was investigated in a Spanish fresh ewes' cheese (Villalón). Counts of mesophiles and psychrotrophs were (log cfu/g) 5.72 +/- 1.10 and 3.90 +/- 1.01, respectively, for factory cheeses made from pasteurized-milk. Figures for hand-made cheeses made from raw-milk were 7.35 +/- 0.48 and 6.94 +/- 0.65, respectively. A total of 59 representative psychrotrophic isolates were characterized and tested for protease and lipase production at 7 and 30 degrees C. The strains were assigned to Enterobacteriaceae (predominant in raw-milk cheese), heterofermentative lactic acid bacteria (dominant in pasteurized-milk cheese and absent in raw-milk cheese) and Pseudomonas. More than 73% of the Enterobacteriaceae produced both proteolytic and lipolytic enzymes at either 30 or 7 degrees C. This percentage is considerably higher than those previously reported. The seven isolates of pseudomonads investigated produced proteases at 7 degrees C and six were positive at 30 degrees C; lipolytic activity was shown by five of the isolates at both temperatures. Among the heterofermentative lactic acid bacteria seven of the ten isolates were proteolytic at 30 degrees C.

Animals↗
PubMed1996

Analyses of functional antibody responses in HIV-1-infected individuals after vaccination with rgp160.

BACKGROUND: The immune response to HIV infection has been extensively studied and the antibody response against the virus has been characterized in detail. It is, however, still unclear which immune function it is most important to stimulate when administering a vaccine against HIV. OBJECTIVES: To analyze the functional antibody responses in asymptomatic HIV-1-infected individuals after vaccination with rgp160. STUDY DESIGN: Forty-nine asymptomatic HIV-1-infected individuals were followed for 9 months and analyzed for changes in functional antibody responses. Forty of them received HIV-1 envelope rgp160 injections and nine did not. RESULTS: Increased levels of antibodies mediating neutralization and cellular cytotoxicity (ADCC) could be seen in subjects who also showed a better CD4 development compared with the patients without increased levels of functional antibodies. Out of nine matched HIV-infected and influenza-immunized controls, none had increased neutralizing activity and only one had an increased ADCC titer. An increased capacity to block soluble CD4 binding to gp120 occurred in 10 immunized patients. Seroreactivity and avidity maturation were detectable to peptides representing consensus HIV-1 envelope regions, indicating an anamnestic response to the patients own virus. CONCLUSIONS: The humoral immune response in HIV-1-infected individuals was moderately influenced by repeated gp160 immunizations, while previous studies have shown that HIV-specific T-cell reactivity was strongly increased.

Journal Article↗
PubMed1996

Optimal Renewal Rate and Nutrient Concentration for the Production of the Marine Microalga Phaeodactylum tricornutum in Semicontinuous Cultures.

A factorial experiment comprising six nutrient concentrations and six renewal rates was set to optimize semicontinuous cultures of Phaeodactylum tricornutum. Maximal cell density, 85 x 10(sup6) cells ml(sup-1), was obtained with 8 and 16 mmol of N per liter and a renewal rate of 10%. Protein stabilized at about 60% of the organic fraction for nitrogen-sufficient cultures. Both lipids and carbohydrates were stored as energetic reserves.

Journal Article↗
PubMed1996

Distinctive control of metabolic pathways by Chlorella autotrophica in semicontinuous culture.

The marine microalga Chlorella autotrophica was cultured semicontinuously under light-dark synchronizing conditions at two nutrient concentrations (2 and 4 mmol N.L-1) and five rates of daily renewal (from 10 to 50% of culture volume). Under such conditions, the biochemical composition of C. autotrophica was strongly influenced by the renewal rate, but unlike other marine microalgae, the nutrient concentration had no effect on the biochemical composition of the organic fraction of the microalga at a given growth rate. Results suggest that this species exerts a strong control over metabolic pathways, independent of the nutrient concentration in the medium.

Carbohydrates↗
PubMed1996

[The effect of angioplasty on cerebral vasomotor reactivity in patients with important stenosis of the internal carotid artery].

INTRODUCTION: We present the preliminary results of the effects on percutaneous translumenal angioplasty (PTA) cerebral haemodynamics in thirty patients with important stenosis of the internal carotidal artery. MATERIALS AND METHODS: Using transcranial doppler (TCD) with acetazolamide (ACZ) as a vasodilatory stimulus, we assessed vasomotor reactivity (VR and pulsatility index (Pl) both before and three months after angioplasty. We also carried out single photon emission computerized tomography (SPECT) and cartography and frequency measurement by electroencephalogram (EEG) again both before and after PTA. RESULTS: Of the first twelve patients who completed the study, VR was maintained in nine and PI increased after PTA in seven. In three patients VR was exhausted and in two recovered after PTA. CONCLUSIONS: PTA improved cerebral haemodynamics. Similar more exhaustive studies are needed if revascularization techniques are to be useful in treating patients with this level of stenosis but who are asymptomatic as to the risk of haemodynamic cerebral vasomotor angioplasty.

Acetazolamide↗
PubMed1996

[Minimally invasive coronary surgery. Thoracostomy-assisted thoracotomy. Apropos a case].

UNLABELLED: CLINICAL CASE PRESENTATION: Male, 62 years old with progressive angina. Positive stress test. At catheterization a proximal 90% stenosis of the LAD was found. Not suitable for PTCA. SURGICAL TECHNIQUE: Double lumen endotracheal tube was inserted. Position was 30 degrees right lateral decubitus. The thoracoscope was introduced through the 7th intercostal space and a minithoracotomy was done. The internal mammary artery (IMA) was dissected partially through direct vision and partially with the help of the thoracoscope. The IMA graft was implanted to the LAD without cardiopulmonary bypass with a segmentary occlusion of the vessel with tourniquets. EVOLUTION: Thoracic drainage 575 cc, CK/MB 311/5, final hematocrit 37%. No blood transfusion. Dismissed on the 5th postoperative day.

Coronary Disease↗
PubMed1996

[Estimation of IgG Adenovirus antibody titers using a standard curve and an indirect ultramicroELISA essay].

It was possible to standardize a procedure which combined an indirect microELISA assay with a standard curve and that allowed to estimate the titre of IgG antibodies to Adenovirus in samples of human serum, using only one dilution of these. Based on the end-point titre previously determined for a panel of 117 serum samples, we selected 90 of these samples (r2 = 0.98) to build 4 standard curves that related the natural logarithm of the fluorescence responses to the natural logarithm of the end-point titre for a wide range of serum dilutions (1:40 = 1:320). It was selected the curve corresponding to serum dilution 1:40 (r2 = 0.81), which made possible an optimum utilization of those accessories designed to handle the volumes in the ultramicro range and, therefore, the automation of the whole procedure. The results obtained as regards the complement fixation test (100% of sensitivity and 97.3% of specificity) support the use of this method in our laboratory as a complementary tool to carry out seroepidemiological studies on a large scale and with diagnostic ends.

Adenovirus Infections, Human↗
PubMed1995

Variability in GPs' referral rates in Spain.

The purpose of this study is to explore the causes that may influence the variations on referral rates in a sample of 242 general practitioners (GPs) in Spain. We applied Poisson multivariant regression modeling to analyze the role played by different variables related to doctors, patients and practices. The mean referral rate was 6.92 +/- 0.22 with a variant coefficient of 50.6%. The results of the Poisson model showed a statistically significant variation on the following variables: 1) doctor gender; 2) proportion of consultations to the practice made by male patients; 3) proportion of consultations made by patients over 65 years of age; 4) list size, 5) number of doctors in the PCT; 6) number of practice consultations to each doctor per week; 7) accredited practice for VT; 8) location of practice; 9) proportion of outpatient referrals; 10) proportion of private referrals; 11) proportion of emergency referrals; 12) proportion of referrals in which the patient's attitude did not influence the doctor for the referral; 13) proportion of new referrals. The statistical significance for the final model was very high (P < 0.00001). The study draws attention to the influence of some structural characteristics of health care system on the referral rates that could be modified to reduce the number of referrals from Primary to Secondary Care.

Accreditation↗
PubMed1995

Numerical characterization study of Micrococcaceae associated with lamb spoilage.

A computer-assisted characterization of 296 Micrococcaceae isolates obtained from aerobically chill-stored lamb carcasses was carried out using a probability matrix and Bayesian identification theorems, complemented with cluster analysis. Preliminary identification was done with an original probability matrix comprising 37 previously described taxa and 32 tests. Although its statistical quality was adequate, the percentage of identification of field strains to species level was only 70% (96.6% identified with genera). To achieve an improved characterization, cluster analysis was subsequently performed on this group and an additional 26% could be associated with defined species, with five more taxa defined. The combined use of both approaches was judged positive as new identifications and better discrimination could be achieved. The majority of our isolates belonged to the Staphylococcus species group. Many species and groups of staphylococci increased as the spoilage progressed.

Animals↗
PubMed1995

[The use of ELISA and ultramicro ELISA in identifying a Coxsackie A9 strain isolated during the epidemic of neuropathy in Cuba].

During 1993 an outbreak of epidemic neuropathy characterized by 2 major clinical forms: the optic neuropathy and peripheral neuropathy, occurred in our country. Although the cause of the disease was considered to be multifactorial (mainly due to neurotoxic agents and to nutritional deficiency) an Enterovirus was isolated from the cerebrospinal fluid of a patient (strain 47/93, IPK) which was subsequently classified as a Coxsackie A9 virus (Cox A9) by the neutralization test, and using pools of Lim Benyesh Melnick (LBM) serum. Results obtained during the application of ELISA and ultramicro ELISA techniques for the identification of this agent from the supernatant of a culture of infected cells are reported, as well as the detection of antibodies to the strain found within populations with high and low incidence rates of the disease.

Antibodies, Viral↗
PubMed1995

[An immunoenzyme assay for the detection of monoclonal antibodies against the E and NS1 proteins of the dengue virus].

The ELISA was standardized to detect monoclonal antibodies of dengue virus proteins E and NS1. One indirect ELISA was applied, using C6-36 cells inoculated with the A-15 strain, isolated during the dengue 2 epidemic in 1981 as an antigen source. These cells were fixed in ELISA plates at a 200,000 cell/well concentration. A cell control in similar conditions was used. Specific monoclonal antibodies to both proteins were used to standardize the system. Studies at different incubation periods, to determine the highest expression moment of these proteins in the cell membrane, were carried out. The results show a full response at 72 hours postinoculation for both proteins; a 14.7 ng/mL sensitivity was obtained for the detection of NS1, and of 1.43 ng/mL for E protein. This system allows the monoclonal antibodies primary screening to dengue 2 virus E and NS1 proteins.

Aedes↗
PubMed1994

Characterization of a human astrovirus serotype 2 structural protein (VP26) that contains an epitope involved in virus neutralization.

An improved purification procedure for human astrovirus serotype 2 (H-Ast2) has facilitated the isolation of a neutralizing monoclonal antibody (PL-2) directed against one of the major structural proteins (VP26) of H-Ast2. A minor component (VP29) of the virus particles is also recognized by PL-2 antibody. Immunofluorescent staining indicated that VP26 (and/or VP29) has mainly a cytoplasmic location in LLCMK2-infected cells. Immunoelectron microscopy demonstrated that the PL-2 epitope was present in the surface of astrovirus particles. Pulse-chase radiolabeling and immunoprecipitation of H-Ast2-infected cell extracts identified a P86 precursor of VP26. Several intermediate protein species (P74 to P35) that shared the PL-2 epitope were also identified in the infected cells. Finally, partial N-terminal sequencing of VP29 and VP26 polypeptides demonstrated that they originated by alternative processing of P86 after residues 361 and 394, respectively. These results corroborate the location of the astrovirus structural genes at the 3' end of the viral genome included in the previously identified 2.8-kb subgenomic RNA.

Amino Acid Sequence↗
PubMed1994

Effect of three commercial starters on growth of Staphylococcus aureus and enterotoxins (A-D) and thermonuclease production in broth.

The growth of four enterotoxigenic Staphylococcus aureus strains was partially inhibited by three commercial starters used in the meat sausage industry when grown in APT broth at 30 degrees C statically. Starter SP318 (a mixture of selected strains of Lactobacillus sake, Pediococcus pentosaceus and Staphylococcus xylosus) showed the most inhibitory activity. Staphylococcal enterotoxins (A, B, C1 and D) synthesis was totally inhibited by the growth of the three starters, whereas staphylococcal thermonuclease production was partially inhibited in mixed cultures.

Animals↗
PubMed1994

Detection of human papillomavirus by nonradioactive hybridization.

The presence of the human papillomavirus (HPV) DNA sequence in cervical smears of women with cervical intraepithelial neoplasia (CIN) was investigated through dot blot using a nonradioactive method based on the principle of enhanced chemiluminiscence. From 154 samples examined, 59 (38.3%) had HPV-related sequences determined by dot-blot hybridization; among these, 18 samples (11.68%) reacted either to HPV 6/11 or to HPV 16/18 probes, 20 (12.98%) reacted to only HPV 16/18, and 21 (13.63%) reacted exclusively to HPV 6/11. The relative sensitivity of the method was controlled comparing the results of both tests with those obtained by Southern blot in 32 samples. The risk of HPV positivity was increased in women who first had intercourse at an early age and in patients with CIN II or III. Both associations were significant at the 95% confidence interval (CI). An increased risk of HPV positivity was also associated with patient's age at diagnosis, education levels, number of sexual partners, and use of oral contraceptives, but none of these factors were significant at 95% CI. Other risk factors for cervical cancer, such as the number of pregnancies or cigarette smoking, were not found to be associated with HPV infection and indicate that the association of these factors with cervical cancer probably is independent of HPV infection. Even if HPV is the major risk factor for CIN, this also supports a multifactorial model of cervical cancer etiology with an increased risk of HPV infection.

Adult↗
PubMed1994

Influence of breast-feeding on the infant's intellectual development.

The objective of this study was to analyze the effects of breast-feeding on the intellectual development of the infant, controlling for possible confounding factors. A prospective study of cohorts was carried out in a group of 229 healthy infants, studied from birth to 2 years of age. The infants were divided into two groups: group 1, 99 infants who were bottle-fed; and group 0, 130 who were breast-fed. All other characteristics in both groups were similar. Psychomotor development was measured between 18 and 29 months using the Bayley scales. Lower results on the Index of Mental Development were associated with bottle-fed infants, lower-middle and lower social class, elementary education of the mother, temper tantrums, and having siblings. Lower results on the Index of Motor Development were associated only with lower and lower-middle social class.

Adult↗
PubMed1994

Staphylococcal growth and enterotoxins (A-D) and thermonuclease synthesis in the presence of dehydrated garlic.

The inhibition of Staphylococcus aureus growth and enterotoxin and thermonuclease production by various concentrations of garlic (Allium sativum) was studied in BHI broth. The growth of Staph. aureus was inhibited by dehydrated garlic at levels of 1.5% (w/v) and over. Enterotoxins A, B and C1 were only detectable in broth containing < 1% of garlic while enterotoxin D was produced at a level of 2%. Garlic also inhibited thermonuclease (TNAse) production, complete inhibition being observed at levels > or = 1.5%. TNAse was not always detected when enterotoxin was present.

Bacterial Toxins↗
PubMed1994

[Design of a curve model for the detection of human immunoglobulin G against herpes simplex virus in ultramicroELISA from a single serum dilution].

The use of a curve model in the application of a ultramicroELISA technique for the detection of human immunoglobulin G against herpes simplex virus is reported. Based on end point titration (linear regression) of 100 initial sera, 51 of these, with r2 > 0.98, were selected, and 4 curve models were elaborated to relate the natural fluorescence logarithm for 4 dilutions with the previously determined natural end point titration logarithm. The curve corresponding to the 1:40 (r2 = 0.9645) was selected to evaluate 39 additional serum samples whose approximate titration was known through the graphic design of the 4 dilutions. An 89% coincidence was found regarding the latter. Divergence of the other 11% was due to the lack of accuracy of the graphic method in the points near the cutline.

Algorithms↗