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Biomedical subjects

A Marco

Publications and source records attributed to A Marco.

At least 19 recordsLinked to original sources
PubMed1998

Sex recognition and mate choice by male western toads, Bufo boreas.

In field-based choice experiments, we examined sex recognition and mate choice in male western toads, Bufo boreas. When given a simultaneous choice between a male and a female of equal size, males did not discriminate between the sexes and attempted to amplex a male or a female with equal frequency. When a test male clasped a stimulus male, the stimulus male uttered a release call that caused the test male to release the stimulus male. Male-male amplexus never lasted more than 3 s, but male-female amplexus was tenacious and prolonged. Furthermore, males discriminated between gravid females that differed in body size, choosing larger gravid females over smaller ones, but they did not discriminate between gravid females or non-gravid females of equal size. In choice tests that excluded chemical cues, males jumped more frequently towards large females than small ones. Given that females are significantly larger than males, selecting larger individuals as potential mates increases the probability that males amplex with a female. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1998

Phase I study of temozolomide in paediatric patients with advanced cancer. United Kingdom Children's Cancer Study Group.

A phase I study of temozolomide administered orally once a day, on 5 consecutive days, between 500 and 1200 mg m(-2) per 28-day cycle was performed. Children were stratified according to prior craniospinal irradiation or nitrosourea therapy. Sixteen of 20 patients who had not received prior craniospinal irradiation or nitrosourea therapy were evaluable. Myelosuppression was dose limiting, with Common Toxicity Criteria (CTC) grade 4 thrombocytopenia occurring in one of six patients receiving 1000 mg m(-2) per cycle, and two of four patients treated at 1200 mg m(-2) per cycle. Therefore, the maximum-tolerated dose (MTD) was 1000 mg m(-2) per cycle. The MTD was not defined for children with prior craniospinal irradiation because of poor recruitment. Plasma pharmacokinetic analyses showed temozolomide to be rapidly absorbed and eliminated, with linear increases in peak plasma concentrations and systemic exposure with increasing dose. Responses (CR and PR) were seen in two out of five patients with high-grade astrocytomas, and one patient had stable disease. One of ten patients with diffuse intrinsic brain stem glioma achieved a long-term partial response, and a further two patients had stable disease. Therefore, the dose recommended for phase II studies in patients who have not received prior craniospinal irradiation or nitrosoureas is 1000 mg m(-2) per cycle. Further evaluation in diffuse intrinsic brain stem gliomas and other high-grade astrocytomas is warranted.

Adolescent↗
PubMed1998

Predictors of adherence to tuberculosis treatment in a supervised therapy programme for prisoners before and after release. Study Group of Adherence to Tuberculosis Treatment of Prisoners.

The prison population is a high-risk group for tuberculosis (TB). This investigation aimed to study predictive factors of treatment adherence among prisoners involved in a pilot programme of supervised treatment. The study included TB patients from the Men's Penitentiary Center of Barcelona (MPCB) in 1995. Directly observed therapy (DOT) was carried out in the infirmary or in a methadone programme. Released prisoners were referred to the municipal maintenance methadone programmes (MMP) and other social resources. Incentives and enablers were used to improve compliance (economic aid for nutritional and housing needs, methadone programmes and admittance to a sociosanitary centre). The outcome of the patients' adherence was classified as follows: completed, defaulted, dead or transferred out. Factors associated with adherence were investigated through logistic regression. The programme included 62 patients, 43 of whom were intravenous drug users (IVDU) and 46 were infected with the human immunodeficiency virus (HIV). Nineteen had previously had TB and 32 were released from prison during TB treatment. Overall adherence was 89%; 97% among those who completed treatment in prison, and 79% among those who completed treatment outside prison (p=0.05). Ninety-five per cent of IVDU in an MMP completed treatment. Homeless or alcoholic exprisoners completed treatment only if they were admitted to sociosanitary centres. DOT throughout treatment resulted in better adherence (odds ratio (OR)= 16.80; confidence interval (CI): 2.42-116.2)). Those who were incarcerated throughout treatment also showed better adherence (OR= 7.36; CI: 0.79-48.16). Antituberculosis treatment adherence in prisoners was high even after release with adequate co-ordination among intrapenitentiary and extrapenitentiary programmes. Maintenance methadone programmes proved very useful in intravenous drug users, as did admittance to sociosanitary centres for indigent or alcoholic exprisoners undergoing treatment.

AIDS-Related Opportunistic Infections↗
PubMed1997

High-performance liquid chromatographic determination and stability of 5-(3-methyltriazen-1-yl)-imidazo-4-carboximide, the biologically active product of the antitumor agent temozolomide, in human plasma.

5-(3-Methyltriazen-1-yl)-imidazo-4-carboximide (MTIC) is a highly unstable compound which is believed to be the biologically active degradation product of the antitumor agent temozolomide. An HPLC method has been developed and validated for the analysis of MTIC in human plasma. Because of the instability of MTIC, sample processing was kept to minimal. The method involved precipitation of plasma protein with methanol followed by analysis of the supernatant using reversed-phase column and UV detection at 316 nm. The linearity (r>0.99), precision (C.V.<9%) and accuracy (bias<5%) were satisfactory. The lower limit of quantitation (LOQ) was 10 ng/ml. The recovery of MTIC and internal standard was > or = 86.7%. MTIC was stable in plasma though three freeze-thaw cycles, and was stable at 4 degrees C for 1 h and at -80 degrees C for at least 70 days. MTIC may be unstable at 10 degrees C in processed samples; therefore, samples were placed in the autosampler (10 degrees C) immediately prior to injection. By using this analytical method, MTIC was quantified in plasma of cancer patients (n=12) within 0.25-12 h after oral administration of temozolomide at 150 mg/m2. The mean maximum plasma concentration (Cmax) was 211 ng/ml which was observed at a mean Tmax of 1.88 h post dose. MTIC disappeared rapidly from plasma with an apparent in vivo half-life (t1/2) of 1.9 h similar to that of temozolomide. Following in vitro incubation of MTIC in human plasma at 25 degrees C, MTIC disappearance was bioexponential with estimated t1/2 values of 25 and 60 min for the first and second phases, respectively. Therefore, the elimination t1/2 of MTIC in human in vivo (1.9 h) was controlled by the rate of its formation from temozolomide.

Administration, Oral↗
PubMed1997

Survival of heated Bacillus coagulans spores in a medium acidified with lactic or citric acid.

The influence of the intensity of heat treatments on the capacity of citric or lactic acid to prevent growth of survivors of Bacillus coagulans spores after 10 days storage at 35 degrees C was studied. In most cases, the number of survivors during storage decreased. The extent of this spore inactivation depended on the intensity of previous heat treatment and the pH of the medium and the acidulant used. The inactivating effect of storage was pronounced even at pH values less acidic than those used by the canning industry. Citric acid was more effective than lactic acid on spores given only low heat treatments, but lactic was more effective against those given more severe heat treatments. The severity of heat treatment required for lactic to be more effective than citric acid increased with pH of the medium. Heat treatment also required increased pH for heated spores to grow. pH 4.6, regardless of acidulant used, was unable to prevent growth of unheated spores but a less acidic pH (pH 5.2) did prevent growth even when spores had been given only mild heat treatments (10 s at 100 degrees C).

Bacillus↗
PubMed1995

[Characteristics of AIDS cases detected at a prison in Barcelona (1991-1993)].

OBJECTIVE: To describe the cases of AIDS detected in a Barcelona prison. DESIGN: A prospective study. SETTING: A penitentiary for men in Barcelona. PATIENTS: All those inmates who had AIDS or were diagnosed with the illness during their stay in prison during the 36 months between 1/1/1991 and 31/12/93. RESULTS: 220 cases of AIDS (91.7% PVDA), 60% of which were diagnosed in prison. The PVDA were younger (p < 0.0001). There were a greater number of Spaniards among the UDVP (p < 0.01) and among those with tattoos (p < 0.001). The first manifestation of the disease in 53% of the cases was extrapulmonary Tuberculosis. CONCLUSIONS: Prisons are key places in the prevention and monitoring of HIV infection. The use of care programmes, including maintenance programmes using Methadone, for drug-dependent patients are recommended. The continuation of programmes tracking Tuberculosis, the main illness related to HIV infection in prison, is also recommended.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Myoepithelial hamartoma of the ileum: a rare cause of intestinal intussusception in children.

Herein we present a case report of a 2-year-old male child who suffered an ileocecal intussusception not reduced by pneumoenema. At the apex of the intussusception there was a 2 cm tumor. The pathologic diagnosis was myoepithelial hamartoma. In a review of the literature we could find no previous reference to myoepithelial hamartomas located in distal ileum causing intussusception in children.

Child, Preschool↗
PubMed1995

Differential characteristics of AIDS patients with a history of imprisonment.

BACKGROUND: AIDS is among the leading causes of death in prisons, but there is little information about AIDS patients with a history of imprisonment. METHODS: AIDS patients diagnosed in Barcelona between 1988 and 1993 were studied. Those with prison histories were compared to those without, with respect to epidemiological variables, including survival analysis. RESULTS: 28.5% of 2336 AIDS patients, 49.4% of intravenous drug users (IVDU) and only 2.6% of homosexuals who were not IVDU had a prison history. Those with prison histories, compared to those without, were younger (median age of 30.6 versus 36.4, P < 0.0001), more often IVDU than homosexuals (87.8% versus 35.8%, OR = 36.9, 95% CI: 22.6-60.8, P < 0.0001), and diagnosed with AIDS because of extrapulmonary tuberculosis (32.0% versus 14.7%, P < 0.001). Among IVDU, those with prison histories were more frequently males (OR: 2.2; 95% CI: 1.6-2.9), lived in the poorest district of Barcelona more frequently than in the richest district (OR: 6.6; 95% CI: 3.4-12.9) and presented with extra-pulmonary tuberculosis more frequently than Pneumocystis carinii pneumonia (OR: 1.7; 95% CI: 1.2-2.4). Longer survival in the prison group did not persist when adjusted for age and AIDS-defining disease. Those with prison histories who presented with AIDS with only extrapulmonary tuberculosis had better probability of survival than those who presented only with P. carinii pneumonia (P < 0.001). CONCLUSIONS: AIDS patients in Barcelona with prison histories tended to be younger, more likely to be IVDU, and to present with extrapulmonary tuberculosis as an AIDS-defining illness than other patient groups. Better survival appears to be related to age and AIDS-defining illnesses in the prison group. The fact that half the IVDU AIDS cases had prison histories has important implications for the care and prevention of HIV, tuberculosis, and drug abuse in comparable prison settings.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Pharmacokinetics and dose proportionality of ceftibuten in men.

The pharmacokinetics and dose proportionality of ceftibuten were evaluated in healthy male volunteers receiving single oral doses of 200, 400, and 800 mg of ceftibuten. The drug was absorbed with similar times to the maximum concentration of drug in plasma for all three doses. Concentrations of ceftibuten in plasma increased with increasing dose. Analysis of variance was carried out on the dose-adjusted values for the maximum concentration of drug in plasma and the area under the plasma concentration-time curve; the results indicated that the concentrations in plasma after the 200- and 400-mg doses were dose proportional, and after the 800-mg of dose they were less than dose proportional. The elimination half-life from plasma ranged from 2.0 to 2.3 h and was independent of dose. The total excretion of unchanged ceftibuten in urine accounted for 53 to 68% of the dose, and the renal clearance was estimated to be 53 to 61 ml/min after all doses. The amount of ceftibuten-trans, the major in vitro and in vivo conversion product of ceftibuten, was low in both plasma and urine.

Adult↗
PubMed1994

Liquid chromatographic determination of ceftibuten, a new oral cephalosporin, in human plasma and urine.

Two liquid chromatographic methods with UV detection were developed for the determination of ceftibuten in human plasma and urine. Diluted plasma samples were directly injected onto a reversed-phase column without prior protein precipitation while diluted urine samples were processed through an automated on-line sample clean-up procedure using column-switching. Both methods were linear over clinically relevant concentration ranges in plasma (from 0.1 to 50 micrograms ml-1) and urine (from 0.5 to 60 micrograms ml-1). The methods showed acceptable precision (RSD < 20%) and accuracy (bias < 15%) at the limit of quantitation (LOQ) for ceftibuten in plasma and urine. These LOQs represented the lowest concentrations of ceftibuten in plasma (0.1 micrograms ml-1) and urine (0.5 micrograms ml-1) that could be measured with acceptable precision and accuracy. RSDs for both within-day and between-day analyses were < or = 12% for plasma and < 7% for urine. These methods have been used successfully for the analysis of ceftibuten in plasma and urine following single oral doses of 200, 400 and 800 mg in man.

Administration, Oral↗
PubMed1994

[The gammagraphic diagnosis of acute pulmonary thromboembolism].

We aimed to determine the prevalence of acute pulmonary embolism (APE) in our population and to establish the diagnostic reliability of pulmonary scintigraphy (PS), as well as the influence of the clinical context (CC). During a 2-year prospective study, patients were diagnosed by either pulmonary angiography or normal-perfusion PS. A diagnosis of APE was made in 73 (75%) of a total of 97 patients. In the group of 58 patients diagnosed by ventilation/perfusion (V/Q) PS, 33 were classified as "highly probably" having APE; 32 of these in fact had the syndrome (sensitivity 88%, specificity 94%). Combining the "highly probable" patients with the "highly suspected" patients diagnosed by ventilation/perfusion PS, we obtained a sensitivity of 51% and specificity of 100%. Ventilation scintigrams were unobtainable in 28 older patients with greater dyspnea and tachypnea, who were unable to perform the maneuvers. Of the 21 "highly probable" patients as assessed by PS, 19 were diagnosed as having APE (sensitivity 86%, specificity 85%). Combining the "highly probable" patients with the "highly suspected" group, we obtained a sensitivity of 32% and specificity of 100%. Normal perfusion PS excludes clinically relevant APE. "Intermediate" or "slight" probability PS results, even when combined with CC, have no diagnostic validity.

Acute Disease↗
PubMed1994

[Pyogenic liver abscess. Study of 20 patients treated with percutaneous drainage].

We conducted a descriptive study of pyogenous hepatic abscesses (PHA) and their treatment with percutaneous drainage and antibiotherapy in the general hospital of Galdácano between 1989 and 1992. We assessed prevalence, clinical characteristics, responses to treatment, evolution and complications. We studied 20 PHAs in adults confirmed through puncture guided with echography and/or computerized tomography. We considered as causal germs those isolated in the abscess and/or hemocultures. All the patients were treated with catheter drainage and antibiotics. After discharge, follow-up and regular TC controls were performed at least for 6 months. The average age of the patients was 56 +/- 3 years and the men/women rate was 2.5:1. The most frequent origin of the infection was cholecystitis/cholangitis in 50% of patients and hydatidic cysts in 20%. Twelve patients had isolated abscess and 8 patients, multiple abscesses. The diagnostic sensitivity was 95% for the echography and 100% for CAT. The most frequent germs were E. Coli, Streptococcus, K. pneumoniae and Salmonella spp. In three cases, it was not possible to bacteriologically identified the germ. After drainage, the abscesses disappeared in 16 patients. The average duration of percutaneous drainage was 10 days. Three patients required surgery after drainage due to complications or incomplete drainage; two other patients required extirpation of hydatidic cysts. The mortality rate was 10%, although it was not related to PHA. We did not observe any differences between isolated or multiple abscesses with regard to prognosis. The drainage guided by echography and/or CT, associated to antibiotic therapy, is a successful technique for the treatment of PHAs in most patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Bioenergetic radiographic absorptiometry in hemodialysis].

UNLABELLED: In order to assess bone loss in uremic renal osteodystrophy (URO), we have measured total and regional mineral bone density (TMBD and RMBD, respectively) by using bioenergetic radiographic absorptiometry (BRA) in a population of patients on hemodialysis (HD). Thirty one patients have been evaluated, with a mean age of 55 and a mean time on hemodialysis of 31 mo. (range 2-120 mo.). Bone absorptiometry consisted of measurement of total body (TMBD) and regional analysis of head, upper limb, lower limb, ribs, pelvis and spine (RMBD). TMBD inversely correlated with alkaline phosphatase and parathyroid hormone levels; it also correlated inversely with age, but only in females. TMBD showed significantly lower values in HD patients than in chronic renal failure patients and controls. All the regional parameters correlated inversely with alkaline phosphatase levels. CONCLUSION: BRA is a non invasive method which quantifies TMBD and RMBD with a very low radiologic exposure and correlates adequately with levels of alkaline phosphatase and parathyroid hormone in URO. TMBD measures total cortical bone of the skeleton with good accuracy, RMBD allows a selective analysis of regional bone changes and a evolutive control in these patients, given the nonuniform decrease of mineral density in the skeleton.

Absorptiometry, Photon↗
PubMed1993

[Congenital prepubic sinus: blind epispadial duplication of the urethra].

Presentation of one case of congenital epispadial urethral duplication in a 1-year old child. The malformation consisted on one normal urethra and the other one a prepubic epispadial accessory urethra, with the proximal end finishing blind into the anterior side of the bladder. The mictional cystography performed showed normal bladder and urethra, while the retrograde urethrography through the dorsal sinus showed a 3 cm long tract with no communication to the urethra or the bladder. Treatment consisted in total exeresis of the accessory urethra by way of suprapubic approach, with no symphysiotomy. Up to the present date, the patient remains asymptomatic.

Epispadias↗
PubMed1992

Effectiveness of pneumatic reduction of ileocolic intussusception in children.

A total of 158 consecutive therapeutic air enemas were performed upon 133 patients during a 2-year period. Perforation and/or an impairment of the general condition of the children were the only main contraindications for the reduction attempt (five patients). Successful reductions were achieved in 89% of cases with no complications. Operation was performed in all 17 cases of unsuccessful reduction: resection in four cases, easy manual reduction in nine, difficult manual reduction in two, and spontaneous reduction in two. There were 16 (12%) patients with one or more recurrent episodes. In 23 (16%) cases, following pneumatic reduction, a swollen ileocecal valve showing a multiple appearance was observed. This fact sometimes results in a differential diagnosis with incomplete reduction; in all these cases, small bowel aeration was always a sign of complete reduction. No significant difference was noted between a swollen ileocecal valve and patient age, duration of symptoms, presence of small bowel obstruction, and further recurrences. Air enema has improved our previous success obtained with hydrostatic reduction (79%), as well as being a simpler, cleaner, and faster technique for intussusception reduction in children.

Air↗