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Biomedical subjects

J Esteban

Publications and source records attributed to J Esteban.

At least 55 records · Page 3Linked to original sources

[Abused children. Role of the pediatrician].

Child maltreatment, in it's different forms (physical, negligence, Münchausen syndrome by proxy, sexual abuses.), represents an important morbidity cause, especially in the first years of the life. Nowadays, the battered child syndrome includes forms of abuse and different degrees of negligence (moderate, serious and light) in which the physical abuse could be absent. Determination of the forms of abuse, their diagnosis, intervention and prevention, corresponds to multidisciplinary teams, in which the pediatrician has a crucial role.

Child↗

Microbiological characterization and clinical significance of Corynebacterium amycolatum strains.

The laboratory records of patients with bacillus isolates identified as Corynebacterium xerosis were reviewed in an attempt to establish the clinical significance of the isolates, and the isolated strains were reidentified. Of the 22 strains available for reidentification, four were identified as Corynebacterium striatum and 18 as Corynebacterium amycolatum. Forty-one patients were considered to have Corynebacterium amycolatum isolates, and in 13 (31.7%) of these patients a genuine clinical infection occurred, comprising catheter-related infection in seven cases, surgical wound infection in five cases, and pilonidal cyst infection in one case. Most patients were treated with antimicrobial agents (vancomycin in seven cases and amoxicillin/clavulanic acid in four cases). All patients were cured. Corynebacterium amycolatum can cause genuine infection, usually hospital-acquired, and the clinical significance of isolates must be determined to ensure proper management of patients.

Adult↗

Pseudo-outbreak of Aeromonas hydrophila isolates related to endoscopy.

Over a two-month period there was a sudden increase in Aeromonas hydrophila isolated from colon i.e., biopsies from patients without related symptoms. Strains were studied by biotyping (API 20 NE, bioMerieux), antibiotyping, plasmid analysis, SDS-PAGE of whole cell proteins and toxicity for cell cultures. All strains gave identical results. In particular SDS-PAGE of whole cell proteins showed an identical electrophoretic pattern for all the strains, and so all were considered to be of the same clone. During the study period, endoscopic materials were disinfected with quaternary ammonia and glutaraldehyde phenate. After these disinfectants were changed to glutaraldehyde 2%, there were no more isolates of A. hydrophila from the biopsies. We conclude that SDS-PAGE can be a useful technique for epidemiological characterization of A. hydrophila.

Aeromonas hydrophila↗

The bactericidal activities of HMR 3004, HMR 3647 and erythromycin against gram-positive bacilli and development of resistance.

The bactericidal activities of two new ketolides, HMR 3004 and HMR 3647, and the potential to develop resistance to these two antibiotics were studied in Gram-positive bacilli. As judged by time-kill kinetics both ketolides were mostly bacteriostatic, being bactericidal against only highly susceptible isolates of Corynebacterium striatum (two isolates) and Corynebacterium minutissimum (one isolate). Spontaneous resistant mutants were detected in seven of 30 strains tested, mainly in Rhodococcus equi, C. minutissimum and C. striatum, with a very low frequency of mutation (10(-12)-10(-15)).

Animals↗

Serum levels of beta-carotene, alpha-carotene, and vitamin A in patients with amyotrophic lateral sclerosis.

To elucidate whether serum alpha and beta-carotene and retinol levels are related with the risk for amyotrophic lateral sclerosis (ALS), we compared serum levels of alpha-carotene, beta-carotene, and retinol (vitamin A), measured by HPLC, in 40 patients with amyotrophic lateral sclerosis (ALS) and 87 matched controls using an isocratic high performance liquid chromatography technique. The mean serum alpha and beta-carotene, and retinol levels did not differ significantly between the 2 study groups. These values were not influenced by the clinical form (spinal vs bulbar) of ALS, and they did not correlate with age, age at onset, and duration of the disease. These results suggest that serum alpha and beta-carotene and retinol concentrations are unrelated with the risk for ALS.

Adult↗

[Infection by resistant Mycobacterium tuberculosis in a hospital population. A longitudinal study of incidental cases at the Fundación Jiménez Díaz].

OBJECTIVE: Evaluation of epidemiologic, clinical and prognostic characteristics in cases of resistant tuberculosis (MRTB). METHODS: Retrospective longitudinal and observational study of resistant cases of tuberculosis at Fundación Jiménez Díaz (1991-1997). Statistical analysis of conventional tests and significance level at p < 0.05. RESULTS: Twenty patients out of 558 with recovery of Mycobacterium tuberculosis showed resistance to some drugs (isoniazid, rifampicin, ethambutol, streptomycin or pyrazinamide). Information was gathered from 19 patients: eight (42%) HIV-positive patients; eight (42%) with the antecedent of tuberculosis (2 abandoned treatment). There were eleven cases (58%) of secondary resistance and eight of primary resistance but only five (25%) with multi-resistance criteria (1 primary and 4 secondary); five cases showed primary resistance to isoniazid. The number of resistances and HIV seropositivity or antecedent of prophylaxis was not statistically significant. In contrast, the higher number of resistances and tuberculosis antecedent were indeed statistically significant. CONCLUSIONS: There was a low resistance rate at our institution. All multi-resistant cases had antecedents of therapy or prophylaxis abandon or previous tuberculosis. Only one case was MRTB. The relevance of complying with a proper therapy is emphasized (consider therapies directly monitored if there is risk of abandon). In patients with epidemiologic risk factors susceptibility studies should be performed and also start therapy with four drugs. The objective is to decrease the percentages of resistance and morbi-mortality.

AIDS-Related Opportunistic Infections↗

Recurrent hepatitis C virus infection after liver transplantation: immunohistochemical assessment of the viral antigen.

BACKGROUND: The value of immunohistochemical methods to identify hepatitis C virus antigen (HCVAg) in liver tissue has not been established. We have evaluated the significance of HCVAg expression in livers of patients with transplants and recurrent hepatitis C virus (HCV) infection. METHODS: Forty-two liver biopsy specimens from 32 liver-transplant recipients with recurrent HCV infection were tested for HCVAg using fluorescein isothiocyanate-labeled polyclonal, polyreactive human immunoglobulin. Histologic assessment of liver and quantitation of HCV RNA in sera were carried out in specimens obtained simultaneously with biopsies. RESULTS: HCVAg was found in 33% of the liver specimens obtained during the first month after transplantation and in all liver specimens obtained between 1 and 18 months after transplantation. Amounts of the antigen were significantly greater in specimens obtained more than 1 month after transplantation. A statistically significant increase of the average HCV RNA level in serum was observed in samples tested after the first month after the transplantation, and some decrease in the HCV RNA level was found in those obtained between 6 and 18 months after transplantation. Larger amounts of HCVAg were observed in specimens corresponding to episodes of acute or chronic hepatitis than in those associated with minimal parenchymal evidence of rejection. CONCLUSIONS: OBSERVATIONS of HCVAg expression in liver biopsy specimens indicated that the presence of viral antigens in hepatocytes is a constant finding in specimens obtained 1 month or longer after transplantation. Although large amounts of HCVAg correlated with acute or chronic hepatitis, the nature of this association with the development of pathologic changes remains to be established.

Adult↗

Cerebrospinal fluid levels of alpha-tocopherol in amyotrophic lateral sclerosis.

We compared CSF and serum levels, and the CSF/serum ratio of alpha-tocopherol (vitamin E), measured by HPLC, in 30 patients with sporadic amyotrophic lateral sclerosis (SALS) and 78 matched controls. The mean CSF and serum vitamin E levels did not differ significantly between the 2 study groups. These values were not influenced by the clinical form (spinal versus bulbar) of SALS. CSF alpha-tocopherol levels did not correlate with age, age at onset, and duration of the disease. These results suggest that CSF and serum alpha-tocopherol concentrations are unrelated with the risk for ALS.

Aged↗

Identification of two mutations and a polymorphism in the chloride channel CLCN-1 in patients with Becker's generalized myotonia.

Myotonia congenita is an inherited muscle disorder characterized by muscle stiffness and hypertrophy. Its clinical phenotype depends, in part, on whether it is inherited as a dominant or recessive trait, respectively designated Thomsen's disease or Becker's generalized myotonia (BGM). In either case, it is associated with abnormalities in the muscle currents that are linked to the gene (CLCN-1) on human chromosome 7q35 encoding the skeletal muscle chloride channel. Single-strand conformation polymorphism analysis was used to screen two families with the BGM for mutations in the CLCN-1 gene. Two new mutations were found (G 201ins and A317Q). The latter mutation has been previously described in Thomsen's disease.

Amino Acid Substitution↗

Cutaneous manifestations of infection by nontuberculous mycobacteria.

Cutaneous infections by nontuberculous mycobacteria (NTM) are not usual but their relative importance has changed during the last few years and still further changes are expected. This study comprised 13 patients from whom NTM were recovered from skin biopsy specimens, sinus exudates or cutaneous abscesses. All samples were processed according to standard methods, and the isolates were identified by biochemical testing. Skin biopsy specimens, when available, were processed for histopathological study. The clinical records of the patients were reviewed, and the relevant clinical, microbiological and epidemiological data collected. The clinical manifestations were noted to be relatively nonspecific and consisted of draining sinuses, abscesses, ulcers and nodules with multicentric or sporotrichoid patterns. Tissue culture isolated Mycobacterium fortuitum complex in nine patients, M. avium in three, and M. marinum in one. In the nine patients studied by histopathology, various patterns were observed. These included dermo-hypodermal abscesses, suppurative granulomas, tuberculoid granulomas and granulomas with a perifollicular distribution. Cutaneous lesions can thus be the first and the only sign of NTM disease, and culture still remains the definitive diagnostic procedure.

Adult↗

Shared tumor antigens in colorectal carcinoma and neuroendocrine tumors.

ND4 monoclonal antibody recognizes a tumor marker found on poorly differentiated colorectal cancer. We demonstrate its expression in 25% of gastrointestinal neuroendocrine tumors, which also express CEA in 37% of cases. As in colorectal cancer the ND4 marker is predominantly membrane bound in a colonic neuroendocrine tumor cell line, LCC-18 (p < 0.05). The ND4 marker is absent in a poorly differentiated colorectal cancer cell line that does not express CEA or other tumor antigens. Shed antigen in the serum of patients with neuroendocrine tumors is detected in only five of seven patients with the carcinoid syndrome and two of four of those without evidence of the syndrome. However, the reactivity was less in the patients with localized disease, and this test is unlikely to be of diagnostic utility in this group of patients. The sharing of this antigen in colorectal cancer and neuroendocrine tumors is not universal, but does support the common-cell progenitor theory for the origin of these tumors.

Animals↗

Number of days required for recovery of mycobacteria from blood and other samples.

From 1991 to 1996, 541 blood samples were tested for the presence of mycobacteria; 56 were positive (30 patients, 26 human immunodeficiency virus positive). The species found were Mycobacterium avium (41 samples from 18 patients), Mycobacterium tuberculosis (12 samples from 9 patients), and three other species (1 sample each). The average time to detection was 25.23 days (22.65 for M. avium and 35.33 for M. tuberculosis). For 10 patients, the blood isolate was the only mycobacterium detected (4 M. tuberculosis).

Cell Culture Techniques↗