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Biomedical subjects

A Marco

Publications and source records attributed to A Marco.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1992

Choroiditis and meningitis in experimental murine infection with Listeria monocytogenes.

In a study of central nervous system involvement in experimental listeriosis 27 Swiss CD1 mice were inoculated subcutaneously with Listeria monocytogenes. Systemic infection developed, as shown by the isolation of Listeria monocytogenes and histopathological lesions in the spleen and liver. In the central nervous system a mixed inflammatory infiltration in the ventricular system, especially in the choroid plexus, and leptomeningitis were the most relevant lesions. Inflammatory lesions were associated with the presence of Listeria monocytogenes, as demonstrated by a positive anti-Listeria monocytogenes immunoperoxidase reaction within phagocytic cells. It is suggested that choroiditis and meningitis developed as a consequence of hematogenous dissemination of Listeria monocytogenes within mononuclear phagocytes and penetration of these cells into the ventricular system through the choroid plexus.

Animals↗
PubMed1992

Histochemical and immunohistochemical study of the mucosal lymphoid system in swine.

Enzyme histochemical and immunohistochemical techniques were used to examine palatine tonsils and aggregated lymphoid follicles (Peyer's patches) of the ileum in 6- to 9-day-old and in 6-month-old pigs. Histochemical techniques were used to detect alpha-naphthyl-acetate esterase (ANAE), alpha-naphthyl-butyrate esterase (ANBE), beta-glucuronidase, adenosine triphosphatase (ATPase), and acid phosphatase (AcP). Nonspecific esterases (ANAE, ANBE) were detected in macrophages, T-cell area lymphocytes, eosinophils, fibroblastic reticular cells (FRC), follicular dendritic cells (FDC), and interdigitating cells (IDC). beta-Glucuronidase reactivity was strong in macrophages, eosinophils, FDC, and IDC, and weaker in FRC. Adenosine triphosphatase reactivity was detected in B-cell area lymphocytes, FDC, FRC, and IDC. Cell types with acid phosphatase reactivity were macrophages, FDC, FRC, and IDC. Nonepithelial cells of tonsils and aggregated lymphoid follicles of the ileum had similar enzymatic reactions. In Peyer's patches, however, epithelial cells were positive for all enzymes studied; in tonsils, only nonspecific esterases were detected. Immunoperoxidase techniques were used to detect S-100 protein and cytoplasmic immunoglobulins (IgG, IgM, and IgA). The S-100 protein was detected in lymphocytes, FDC, and FRC of tonsils and Peyer's patches; in tonsillar epithelial and endothelial cells; and in IDC of Peyer's patches.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid Phosphatase↗
PubMed1992

Biliary excretion as possible origin of Listeria monocytogenes in fecal carriers.

The presence of Listeria monocytogenes in feces of animals has been related with ingestion of contaminated foods. In the study reported here, healthy mice inoculated SC with L monocytogenes excreted the organism in their feces, regardless of whether they developed clinical signs of infection. Listeria monocytogenes was isolated simultaneously from liver, feces, and bile of inoculated mice, which strongly suggested that the microorganism reached the gastrointestinal tract by biliary excretion.

Animals↗
PubMed1990

Scanning electron microscopy of swine lymphoid organs.

The aim of this investigation was to study by scanning electron microscopy the structure of several swine lymphoid organs (lymph nodes, Peyer's patches, and tonsil). Two groups of animals were used: six-month-old pigs and six- to nine-day-old piglets. Samples were jet-washed to eliminate most free cells in order to observe the reticular framework of these organs more clearly. Peyer's patches in piglets showed two types of villi. In one of them the cellular types were absorptive cells and goblet cells. The second type of villi were shorter and wider, with M cells characterized by presenting long, thick microvilli over their surfaces. Peyer's patches of pigs did not show this second type of villi but were usually covered by absorptive villi. The soft palate tonsil was similar in both groups of animals with its surface epithelial cells full of microfolds, partially and frequently obscured by microorganisms. The appearance of the surface epithelium in the same crypt was different depending on the area. There was a large number of holes through which cells apparently passed towards the crypt lumen. The medulla in the lymph nodes was at the periphery and showed a dense reticular framework. Cortex-like lymphoid tissue was formed by lymphoid follides and diffuse lymphoid tissue with high endothelid venules and lymphatic sinuses. The serosal surface of lymphoid organs was formed either by a typical mesothelial cell layer (small intestine) or by loosely arranged connective fibers (lymph nodes).

Animals↗
PubMed1989

Serological diagnosis of listeriosis in man, sheep and rabbit by immunoperoxidase technique.

Due to the already demonstrated specificity and usefulness of Listeria intracellular antigen in paraffin-embedded tissues for the direct diagnosis, we have used an indirect immunoperoxidase technique for the serological diagnosis of listeriosis in man, sheep and rabbit. This technique has been compared with other immunoperoxidase techniques (PAP) using the same antigen, and with other serlogical techniques--ELISA and microplate agglutination test--using two kinds of Listeria antigens, live formalinized and heat at 100 degrees C for one hour whole cells.

Agglutination Tests↗
PubMed1988

Increased soluble interleukin-2 receptor levels in the sera of type 1 diabetic patients.

Recently, the presence of a soluble form of IL-2 receptor (IL-2RS) in human sera and in supernatants of PHA-stimulated lymphocytes has been demonstrated. It has been suggested that autoimmune diseases could be characterized by a defect in production of IL-2RS, unlike immunoproliferative disorders which are characterized by overproduction. Our aim was to investigate serum IL-2RS levels in 35 newly diagnosed Type 1 diabetic patients, in 25 age-matched healthy blood donors and in five patients with Hodgkin's disease. We found that newly diagnosed diabetic patients have higher IL-2RS levels (424.8 +/- 203 U/ml) than normal controls (252.4 +/- 38.4 U/ml) (p less than 0.005). In 22 out of 35 patients (62.8%) the IL-2RS values were above the higher 95% tolerance limit of controls. Furthermore, the persistence of high IL-2RS levels was observed in 18/35 diabetic patients six months after diagnosis (470 +/- 195.6 U/ml). The increased levels were not correlated with glycaemic and HbA1c levels and patients' age. Our findings suggest a potentially significant role for the released IL-2R in the regulation of IL-2 dependent lymphocyte functions in Type 1 diabetes. The study of IL-2RS in Type 1 diabetes may provide a new tool for the knowledge of cytokine involvement in the disease.

Adolescent↗
PubMed1987

Pharmacokinetics and metabolism of an intravenously administered penem (Sch 34343) in humans.

The pharmacokinetics of Sch 34343, a new broad-spectrum penem antibiotic, was studied in subjects receiving 1 g of 14C-labeled drug by intravenous administration. At the end of a 30-min intravenous infusion, the mean maximum concentration of drug in serum was 39 micrograms/ml for unchanged Sch 34343 and 49 mu eq/ml for total radioactivity. The mean serum half-lives of Sch 34343 were 0.16 h for the distribution phase and 0.80 h for the elimination phase. The total body clearance of Sch 34343 was 7.52 ml/min per kg, and the mean apparent volume of distribution was 525 ml/kg. Over a 4-day period, mean urinary excretion of radioactivity accounted for 87.9% of the dose, and mean urinary excretion of unchanged Sch 34343 accounted for 23.6% of the dose. The total radioactivity in feces on days 0 to 6 accounted for only 0.8% of the dose. In serum from 0.5 and 1 h, unchanged Sch 34343 represented the major radioactive peak, with negligible amounts of several metabolites. In urine, there were at least six metabolites in addition to Sch 34343. The amount of unchanged Sch 34343 accounted for 33% of radioactivity in samples of urine from 0 to 2 h, 22% in urine from 2 to 4 h, 15% in urine from 4 to 8 h, and 0% in urine from 8 to 12 h.

Adult↗