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Biomedical subjects

P Alonso

Publications and source records attributed to P Alonso.

At least 55 records · Page 3Linked to original sources
PubMed1997

Analysis of multiple Plasmodium falciparum infections in Tanzanian children during the phase III trial of the malaria vaccine SPf66.

In the first phase III efficacy trial of the malaria vaccine SPf66 in Africa, MOIs in SPf66- and placebo-vaccinated children were analyzed by polymerase chain reaction-restriction fragment length polymorphism of the Plasmodium falciparum merozoite surface antigen 2 (MSA2). MOIs were significantly reduced in asymptomatic vaccine recipients compared with those in asymptomatic placebo recipients; however, no differences were observed among symptomatic children in the vaccine and control groups. These results show that immunization with SPf66 modulates the course of naturally occurring infections, as reflected by reduced MOIs. In placebo recipients, however, there was a significant negative correlation between numbers of infecting genotypes, as identified by MSA2, and morbidity. Asymptomatic placebo recipients had an average of 5 concurrent infections, whereas children with clinical cases had an average of 3.4 infections. These data provide further evidence that premunition from concurrent infections is important in immunity against clinical malaria. No such effect of multiple infections was found in the vaccinated group.

Animals↗
PubMed1996

Prospective study of Streptococcus milleri bacteremia.

In a prospective study of bacteremia caused by organisms of the Streptococcus milleri group a total of 32 adult patients were observed over a seven-year period. These patients accounted for 1.6% of all patients diagnosed as having significant bacteremia and 17% of all cases of streptococcal (nonpneumococcal) bacteremia diagnosed during the study period. Only five patients had polymicrobic bacteremia. In 31 cases, a presumed origin of infection was identified, generally oral or gastrointestinal disease. There were only six cases of nosocomial acquisition. The most common presenting symptom was prolonged fever. The following forms of presentation were documented: bacteremia with local suppurative infection (56%), bacteremia without local suppurative infection (25%), and endocarditis (19%). An associated focus of infection was found in the abdominal cavity in 20 cases (62%). The mortality rate was 12.5%. All isolates were susceptible to penicillin. Caution is necessary in interpreting a blood culture positive for Streptococcus milleri group organisms, since, unlike other viridans streptococci, they are rarely contaminants. For this reason patients with suppurative processes and/or digestive tract disease must be carefully investigated.

Adult↗
PubMed1996

Comparison of partially attended night time respiratory recordings and full polysomnography in patients with suspected sleep apnoea/hypopnoea syndrome.

BACKGROUND: Laboratory full polysomnography (PSG) is considered to be the gold standard for the diagnosis of the sleep apnoea/hypopnoea syndrome (SAHS), but it is expensive and time consuming. A study was undertaken to evaluate the diagnostic usefulness of a partially attended night time respiratory recording (NTRR) and a clinical questionnaire in patients with suspected SAHS in comparison with full PSG. METHODS: Seventy six patients (54 men) of mean (SD) age 51 (11.5) years with a body mass index of 31 (5.7) kg/m2 were studied at random on two different nights with full PSG at the sleep laboratory and with NTRR on a respiratory ward. NTRR records oximetry, airflow, chest and abdominal motion. All signals were continuously displayed on a computer screen throughout the night and respiratory events were scored automatically the following morning. All patients completed a clinical questionnaire. RESULTS: Mean values of the apnoea/hypopnoea index (AHI) using NTRR were lower than those obtained with full PSG (22.7 (2.4) versus 32.2 (3) events/hour) which was mainly due to underrecognition of hypopnoeas. Sensitivity and specificity of NTRR for the diagnosis of SAHS were 82% and 90%, respectively, taking as reference AHI > 10 on full PSG (AHI-PSG > 10). The mean (+/-2SD) difference in AHI between the two methods was 9.6 (range -5.4-24.6) (95% confidence interval 6.2 to 13). Symptoms of witnessed apnoeas, impotence, the overall clinical impression of a trained physician, and a neck size over 40 cm were significantly more prevalent in patients with AHI-PSG of > 10, but impotence was the only clinical feature significantly more prevalent in patients with false negative compared with true negative NTRR results that helped to distinguish patients with NTRR < 10 but AHI-PSG > 10. CONCLUSIONS: NTRR is a helpful and easy complementary diagnostic tool in clinical practice because it detects patients with moderate to severe SAHS reasonably well and therefore can be useful for confirming a diagnosis of SAHS and also for treatment decisions. It is suggested that patients with suspicion of SAHS should be initially studied by NTRR. When NTRR is negative, a full PSG should be performed if witnessed apnoeas, impotence, systemic hypertension, ischaemic heart disease, and a trained physician's clinical impression of SAHS are present.

Adult↗
PubMed1996

[Esophageal mucosal lesions and scleroderma: prevalence, symptoms and risk factors].

Scleroderma or systemic sclerosis (Ssc) is a connective tissue disease which frequently involves the esophagus. Motility disorders, such as a low pressure level in the Lower Esophageal Sphincter (LES), and disturbed esophageal peristalsis cause a higher acid exposition and mucosal damage. We study twenty Ssc patients using computerized esophageal manometry, endoscopy and clinical interview looking for prevalence of symptoms, esophageal dysmotility and erosive esophagitis, and trying to find risk factors involved in esophageal damage. Esophagitis was found in 40% of patients. Clinical presentation (diffuse or limited), age and time since diagnosis wer'nt accurate predictors of esophageal involvement. Symptoms such as dysphagia and heartburn had not any significant difference in those with and without esophagitis, so 25% of patients with mucosal damage had no symptoms and 60% of healthy ones complained about them. LES values were not significantly different between the two groups, with a great degree of overlap with normal values. Disturbed motility pattern of aperistalsis was the only factor that identified high and low risk groups for esophagitis, with a high statistical significance (p > 0.02). Mucosal sensitivity in severe esophagitis and pharyngeal and upper esophageal functions were normal in all patients. Impaired peristalsis, with a delayed clearance of acid is the most important factor for mucosal damage in scleroderma. Symptoms of gastroesophageal reflux are not a reliable predictor of erosive esophagitis. Endoscopy should be the usual method of diagnosis, in order to make a proper use of therapeutic weapons.

Adult↗
PubMed1995

The effect of amphotericin B on the viability of cryopreserved human skin.

To evaluate whether amphotericin B has a detrimental effect on the viability of cryopreserved skin, human skin samples were incubated during 7 and 24 h in three different media: 0.9% phosphate-buffered saline and Medium 199 with and without 10 micrograms/ml amphotericin B. The viability of the tissue was assessed by measuring the tetrazolium reductase activity before and after cryopreservation. A significant decrease in cryopreserved human skin viability was observed after 7 and 24 h incubation with amphotericin B. These results indicate that in the processing of skin preservation, the beneficial effect of using amphotericin B as an antifungal agent may be reduced by its negative effect on tissue viability.

Amphotericin B↗
PubMed1995

Early prediction of stroke severity. Role of the erythrocyte sedimentation rate.

BACKGROUND AND PURPOSE: Early predictors of functional outcome after stroke are necessary for better planning of treatment and care. METHODS: We evaluated prospectively early clinical predictors of short-term functional outcome in a group of patients with ischemic cerebral infarction and explored whether the intensity of the acute-phase response provided further information concerning the short-term functional outcome. We evaluated a group of 208 ischemic stroke patients using the Mathew scale at entry. All patients had neuroimaging studies and routine blood tests, including erythrocyte sedimentation rate (ESR), within 72 hours from clinical onset. At discharge, functional outcome was graded according to a Stroke Outcome Scale. RESULTS: Larger infarcts, more embolic infarcts, and fewer lacunar infarcts were observed in the poor-outcome group. Vascular risk factors, radiological findings not related to the index stroke, time to admission, and treatment were similar in the two outcome groups. Variables with statistically significant differences between outcome groups included the following: age > 65 years, female sex, admission Mathew score < 75, worsening at clinical presentation, infarct volume > 6 cm3, complicating infections, fasting glucose > 110 mg, nonfasting glucose > 130 mg, and elevated ESR. With stepwise logistic regression analysis, Mathew score on admission, infarct volume, mode of clinical presentation, and ESR remained in the predictive model of stroke outcome, with a sensitivity and specificity of 89.91% and 85.71%, respectively. After removing the computed tomographic information from the model the same variables remained, with a sensitivity and specificity of 83.05% and 94.29%, respectively. CONCLUSIONS: Infarct size and clinical severity on admission are the stronger predictors of short-term functional outcome. Mode of clinical presentation, clinical evolution during the first day of stroke, and ESR are also independent predictors of short-term stroke outcome. These findings might be indicative of an inadequate collateral profile and/or a more pronounced prothrombotic state.

Adult↗
PubMed1994

Characterization of SPf(66)n: a chimeric molecule used as a malaria vaccine.

SPf66 is a chemically synthesized 45 amino acid peptide derived from fractions of four different proteins of Plasmodium falciparum (83, 55 and 35 kDa and CS, the circumsporozoite protein) that elicits a protective immune response against malaria. In this paper we show the characterization of the SPf(66)n in batch 9 to be used in a field trial in young children at Ifakara in Tanzania. The analysis of SPf(66)n indicates that it is highly soluble in water and that the amino acid composition and sequence corresponds to that designed for the synthesis of the polypeptide. The packed product has a molecular weight ranging from 10 to 25 kDa. It is pure, free of metallic contaminants, atoxic and stable at 4 degrees C. The antibodies raised against this product in rabbits recognize the individual antigenic determinants of the molecule and the native epitopes of merozoites.

Amino Acid Sequence↗
PubMed1993

Prognostic value of the CD4/CD8 lymphocyte ratio in moderately burned patients.

We investigated CD3+, CD4+ and CD8+ T-cell subpopulations, as well as the CD4/CD8 ratio in 84 moderately burned patients with injuries affecting 11-36 per cent of their total body surface area (TBSA). These lymphocyte subpopulations were quantified by indirect immunofluorescence measurement 7 and 60 days postburn. The results obtained 7 days postburn were highly significant in those patients who developed septicaemia, all of whom had considerably decreased CD4+ and increased CD8+ T-cell numbers, as well as inverted CD4/CD8 ratios. Consequently, the CD4/CD8 ratio may provide valuable information for prognosis of patient evolution and the establishment of early treatment in order to avoid likely future complications.

Adolescent↗
PubMed1992

[Intestinal inflammatory disease in the province of Soria. Retrospective clinical and epidemiologic study from 1981 to 1990].

The inflammatory bowel disease cases in Soria have been reviewed from 1981 to 1990. Thirty-two cases of ulcerative colitis (UC) and thirteen cases of Crohn's disease (CD) have been found. The mean incidence was 3.2/100.000 inhabitants/year in UC and 1.3/100.000/inhabitants/year in CD. The prevalence was 32 and 13/100.000 inhabitants respectively. We have found a progressive increase in incidence in both UC and CD during the period analyzed. Epidemiologic data (considering the majority come from rural areas), clinical course, endoscopic and radiologic findings, are similar to the results published in the literature. We have found a minor percentage that other authors in extraintestinal signs, complications and need of surgical intervention.

Adolescent↗
PubMed1991

The apical oblique view of the clavicle: its usefulness in neonatal and childhood trauma.

We analyzed clavicular radiographs of 26 patients with a history of trauma. The apical oblique projection of the clavicle was obtained with the injured side of the patient angled 45 degrees towards the X-ray tube and a 20 degrees cephalad angulation of the X-ray beam. This view proved to be more informative than the routine apical anteroposterior projection. It is especially effective in detecting nondisplaced fractures of the middle third of the clavicle in neonates and children. To verify our findings, we obtained apical anteroposterior and oblique radiographs of a specimen adult clavicle. On the oblique view with 20 degrees cephalad angulation of the X-ray beam, the measurements of the projected lengths of the anatomical specimen, especially those of the middle portion of the clavicle, were very close to the corresponding anatomical lengths.

Birth Injuries↗
PubMed1991

Risk factors for HIV-2 infection in The Gambia.

A serosurvey was carried out to assess the prevalence of HIV infection in The Gambia and the importance of possible risk factors. The overall prevalence of HIV-2 infection among the 4228 adults studied was 1.7% while that of HIV-1 was 0.1%. The prevalence of HIV-2 was similar in both sexes but higher among those greater than 25 years of age and those who lived in two small towns along a main transport route. Among men, multivariate analysis showed prevalence of HIV-2 infection was significantly greater among those in the more affluent occupations, those without a secondary education and those with a history of urethral discharge. Among women, infection was more frequent in divorcees and widows and those who had been married several times. The prevalence was also higher in individuals born in Guinea-Bissau and in an ethnic group which originated there.

Adolescent↗
PubMed1991

Neonatal cavernous hemangioma of the dura mater: case report.

A case of dural cavernous hemangioma, diagnosed prenatally as an intracranial mass by ultrasonography and surgically treated after elective delivery, is presented. The clinical and pathological features of this unusual type of congenital vascular malformation are reported, and the relevant literature is reviewed.

Adult↗