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Biomedical subjects

P Alonso

Publications and source records attributed to P Alonso.

At least 19 recordsLinked to original sources
PubMed1999

Achalasia: the usefulness of manometry for evaluation of treatment.

Although manometry is used with increasing frequency to evaluate the effectiveness of different treatments for achalasia, the criteria for a successful manometric response have not been well defined. Manometric responses were collected before and after 43 treatments in 35 patients with achalasia in order to determine manometric changes after different clinical outcomes: 15 unsuccessful outcomes and 28 successful outcomes were reported. In the latter, resting pressure of the lower esophageal sphincter decreased to 12.8 mm Hg, whereas in unsuccessful outcomes this was significantly higher (28.2 mm Hg). A decrease of lower esophageal sphincter pressure below 17 mm Hg or more than 40% of the pretreatment level was associated with successful outcomes. Our data suggest that manometry is a good indicator of therapeutic effectiveness and we propose that it be used systematically for objective evaluation of achalasia treatment.

Catheterization↗
PubMed1998

Clinical evaluation of a commercial ligase-based gene amplification method for detection of Mycobacterium tuberculosis.

The purpose of this study was to evaluate the clinical usefulness of a commercial ligase-based gene amplification method (LCx Mycobacterium tuberculosis test; Abbott Laboratories, USA) for detection of Mycobacterium tuberculosis. The tuberculosis infection rate among clinical samples was 10.6%. The sensitivity, specificity, and positive and negative predictive values were 23.5%, 100%, 100%, and 91.7%, respectively, with the fluorochrome auramine stain; 32.4%, 100%, 100%, and 92.6%, respectively, with culture; and 76.5%, 95.8%, 68.4% and 97.2%, respectively, with the gene amplification method. When only samples from patients without current or previous treatment were studied, the sensitivity was 36.4% with the auramine stain, 63.6% with culture, and 100% with the gene amplification assay. The mean treatment time for culture-negative and assay-negative samples was greater than that of culture-negative and assay-positive samples. The LCx Mycobacterium tuberculosis test is a sensitive method for detection and identification of Mycobacterium tuberculosis. It produces few false-positive results. However, as it can remain positive after the culture becomes negative, it is not recommended for evaluation of treatment efficiency.

Bacteriological Techniques↗
PubMed1998

Prospective study of Streptococcus milleri hepatic abscess.

Thirty-seven cases of microbiologically demonstrated pyogenic hepatic abscess were observed in a prospective study over a seven-year period. Biliary disease was the most common source of liver abscess (42%). Streptococcus milleri was the most common cause of hepatic abscess, accounting for 51% of the cases. Hepatic abscess is due to Streptococcus milleri clinically distinct from other forms of pyogenic liver abscess due to its torpid nature and the longer duration of its symptoms [42 vs. 11 days]. Occult hepatic abscess should be suspected if the blood culture is positive for Streptococcus milleri, since 28% of bacteremia cases due to Streptococcus milleri stem from hepatic abscesses. It is important to distinguish Streptococcus milleri from other members of the viridans streptococci group, which are frequently isolated as contaminants, but only exceptionally cause hepatic abscess. Unlike other pyogenic hepatic abscesses, those caused by Streptococcus milleri are frequently monomicrobial (79%). In the present study, empirical therapy of pyogenic hepatic abscess always included a drug that is effective against Streptococcus milleri.

Female↗
PubMed1998

[Variants of hepatitis C virus in different risk groups. Comparative study of a method for genotyping and another for serotyping].

AIMS: The aim of this study was to know the prevalence of the different variants of HCV in the Health Care area of Monforte de Lemos (Lugo, Spain) and its distribution according to risk factors and to compare the results obtained with one genotyping and one serotyping technique. PATIENTS AND METHODS: Eighty-four patients with hepatitis C were studied, 25 of whom were IVDA, 14 had received blood transfusions, 4 hemodialysis and the risk factor was unknown in 41. The antibodies against HCV were studied by second generation EIA and confirmed by an immunoblot technique. Serotyping was carried out by an ELISA test. Genotyping was undertaken with a reverse hybridation test of the amplification obtained by polymerase chain reaction prior to reverse transcription (RT-PCR). RESULTS AND CONCLUSIONS: The genotypes most frequently observed were 1b (47.6%), 1a (20.2%) and 3 (14.3%). In the IVDA patients the genotypes 1a (40%) and 3 (24%) predominated. The 1b genotype was the most prevalent in the patients of unknown risk (68.3%) and patients with a history of blood transfusion (50%). The prevalence of the different serotypes was similar to that of the corresponding genotypes, with nearly 100% agreement. The number of untypable cases was greater in the serotyping technique (20.2%) than in the genotyping (2.4%). A greater number of mixed infections was detected with serotyping (7 cases, 8.3%) than with genotyping (1 case, 1.2%). Lesser sensitivity of the serotyping test was observed in the patients lacking anti-NS4 antibodies.

Blood Transfusion↗
PubMed1997

GABAergic drugs inhibit amphetamine-induced distractibility in the rat.

Drugs facilitating GABAergic neurotransmission have been reported to block some behavioral actions of dopaminergic stimulation but not others. The present experiments were performed with the purpose to extend the range of behaviors in which the interaction between GABA and dopamine have been studied. The ability of the GABAB agonist baclofen and the GABA transaminase inhibitor sodium valproate to block the enhanced distractibility produced by amphetamine was evaluated in a procedure especially designed for analyzing drugs' effects on distractibility. Briefly, rats were trained to traverse a straight runway with a sucrose solution as reinforcement. Once the response had been acquired, an additional runway ending in an empty box was connected. The time spent investigating this additional runway is the measure of distractibility. Male rats treated with amphetamine, 1 mg/kg, displayed an increase of the time spent in the additional runway. Baclofen, 2.5 and 5 mg/kg, and sodium valproate, 100 and 200 mg/kg, had no effect on distraction behavior when administered alone. However, when these drugs were administered together with amphetamine, 1 mg/kg, they completely inhibited the effects of the stimulant on distractibility. These data show that distractibility is similar to discrimination learning with regard to the capacity of GABAergic drugs to block the effects of dopaminergic stimulation. It is different from locomotor activity, however, where GABAergic drugs are ineffective in this respect.

4-Aminobutyrate Transaminase↗
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↗