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Biomedical subjects

J Esteban

Publications and source records attributed to J Esteban.

At least 73 records · Page 4Linked to original sources

Bone marrow biopsy in the diagnosis of fever of unknown origin in patients with acquired immunodeficiency syndrome.

BACKGROUND: Fever is commonly observed in patients with human immunodeficiency virus (HIV) disease and frequently eludes diagnosis. The role of bone marrow biopsy in the diagnosis of fever of unknown origin in patients infected with HIV remains controversial. PATIENTS AND METHODS: One hundred twenty-three consecutive patients with 137 episodes of fever lasting 10 or more days without diagnosis after 1 week of hospitalization were evaluated by bone marrow biopsy. RESULTS: Overall, a specific diagnosis was achieved in 52 episodes by means of culture and histopathological examination (diagnostic yield, 37.9%). Three types of disease were found: mycobacterial infections (n = 36, 69% of documented episodes), including 18 patients with disseminated tuberculosis and 14 with Mycobacterium avium-intracellulare complex infections; non-Hodgkin lymphomas (n = 12, 23%); and visceral leishmaniasis (n = 4, 8%). Although bone marrow cultures were more sensitive than microscopic examination with special stains for the diagnosis of mycobacterial infections, the pathological examination of bone marrow led to a more rapid diagnosis of disease. In addition, the histopathological examination of bone marrow alone led to the diagnosis of a specific condition in 43 episodes (31.3% of all episodes). CONCLUSIONS: Bone marrow biopsy is a useful procedure for the diagnosis of fever in patients with advanced HIV disease, particularly in areas where tuberculosis and leishmaniasis are prevalent. Involvement of the marrow may be the first indication of the existence of extranodal non-Hodgkin lymphoma. For Mycobacterium avium-intracellulare complex infection, blood cultures were more sensitive than bone marrow biopsy.

AIDS-Related Opportunistic Infections↗

[Clinical significance of the isolation of rapidly growing mycobacteria].

BACKGROUND: To assess the clinical significance of the isolates of rapid-growing mycobacteria in a Universitary hospital from Madrid (Spain). PATIENTS AND METHODS: Review of medical records from patients with isolates of rapid-growing mycobacteria identified between 1979 and 1996 in the Microbiology department of the Fundación Jiménèz Díaz (Madrid, Spain). RESULTS: Rapid-growing mycobacteria were isolated from 28 patients during the study period (13 M. chelonae, 10 M. fortuitum, 2 M. mucogenicum, 1 M. marinum, 1 M. smegmatis and 1 M. flavascens). Clinical records of 26 patients were reviewed, being the isolate significative in 10 cases (5 soft tissue infections, 2 peritonitis in patients undergoing Continuous Ambulatory Peritoneal Dialysis [CAPD], 1 urinary tract infection, 1 osteomyelitis and 1 catheter-related soft-tissue infection). No patient was HIV+. All infections cured except 2 of them (the urinary tract infection and the osteomyelitis). Catheter withdrawal was needed in 3 cases (peritonitis in CAPD and catheter-related soft-tissue infection), apart from proper antimicrobial therapy. CONCLUSION: The most frequent rapid-growing mycobacteria isolated were those of the M. fortuitum complex. In our experience, isolation of rapid-growing mycobacteria from skin and soft-tissue samples was usually clinically significant, while isolates from respiratory tract, gut and blood cultures are always nonsignificant.

Adult↗

Role of endogenous sulphydryls and neutrophil infiltration in the pathogenesis of gastric mucosal injury induced by piroxicam in rats.

In the present report we studied the formation of severe gastric erosions produced in fasted rats by intragastric administration of piroxicam (PRX), an enolic acid-derived NSAID. The time course of gastric damage and the possible role of mucus secretion, endogenous sulphydryl compounds, changes of gastric vascular permeability and neutrophil infiltration in the development of PRX-induced gastric lesions were also investigated. PRX dose-dependently (1.25-20 mg/kg) caused acute gastric haemorrhagic erosion in the rat. The lesions increased with time until 9 hr after dosing. Mucus secretion did not change significantly with respect to the control group with 5, 10 and 20 mg/kg of PRX at different times (3 and 6 hours) of treatment. There was also no increase in the concentration of its components. In addition, oral pretreatment of the animals with PRX did not significantly change the amount of dye trapped in the stomach. In contrast, non-protein SH fraction was decreased after administration of PRX and MPO activity as an index of neutrophil infiltration was significantly increased. These results suggest that independently of the PRX dose, depletion of endogenous non-protein SH and neutrophil infiltration could play an important part in the pathogenesis of gastric mucosal injury induced by PRX.

Animals↗

Hypokalemic periodic paralysis mutations: confirmation of mutation and analysis of founder effect.

In three families with hypokalemic periodic paralysis (HOPP) we have confirmed the presence of a missense mutation (arginine 528 to histidine) within the gene CACNL1A3 encoding the alpha 1 subunit of the L-type, voltage-sensitive calcium channel. Additionally, we have identified two novel polymorphisms within this gene located in close proximity to the mutation. Haplotype analysis using these and other polymorphisms indicates that these families do not share a common mutation due to a founder effect. Rather, an HOPP phenotype has arisen in these families from three separate but identical mutations.

Adolescent↗

Three novel mutations and two variants in the gene for Cu/Zn superoxide dismutase in familial amyotrophic lateral sclerosis.

Autosomal dominant inheritance is exhibited by about 10% of cases of amyotrophic lateral sclerosis (ALS), a paralytic disorder characterized by the death of motor neurons in the brain and spinal cord. A subgroup of these familial cases are linked to mutations in the gene which codes for Cu/Zn superoxide dismutase (SOD1). We report three additional mutations occurring in the SOD1 gene in ALS patients and two single base pair variant changes. The single base pair change in an ALS family causes a glycine 93 to valine substitution, which is the fifth distinct amino acid change reported for the glycine 93 residue. One missense mutation in exon 5 would substitute neutral valine for the negatively-charged aspartate 124 (aspartate 124 to valine). An individual with an apparently sporadic case of ALS carries a three base pair deletion in exon 5 of the SOD1 gene. These three mutations bring to 38 the total number of distinct SOD1 mutations associated with familial ALS.

Amyotrophic Lateral Sclerosis↗

Aromatase gene expression and its exon I usage in human breast tumors. Detection of aromatase messenger RNA by reverse transcription-polymerase chain reaction.

The expression of aromatase in human breast tumors has been studied by the reverse-transcription polymerase chain reaction (RT-PCR) method on 70 breast tissue specimens. An RT-PCR analysis using two oligonucleotide primers derived from the exon II of the human aromatase gene revealed that aromatase mRNA was detected in all but three tissue specimens. Furthermore, primer-directed RT-PCR was performed to determine the exon I usage in aromatase mRNA in these breast tumor specimens. The analysis has revealed that exons I.3 and PII are the two major exon Is present in aromatase mRNA isolated from breast tumors, suggesting that promoters I.3 and II are the major promoters driving aromatase expression in breast cancer and surrounding adipose stromal cells. The RT-PCR analysis also detected two products, I.3A (334 bp in length) and I.3B (222 bp in length), when it was carried out using a primer derived from exon I.3 and a reverse primer derived from exon II. The nucleotide sequences of these products have been determined and indicate that I.3A contains a region which was previously thought to be an intron. In addition, RT-PCR analyses of RNA isolated from eight pairs of breast tumor and neighboring normal tissue specimens were performed to evaluate the exon I usage and the distribution of I.3A- and I.3B-containing aromatase RNA messages in breast tumor and neighboring normal tissues. The results suggest that I.3B- and I.3A-containing messages are mainly present in breast tumor and neighboring normal tissues, respectively. Finally, the exon I/promoter usage for aromatase expression in eight cell lines (skin fibroblast, MCF-7, MDA-MB-231, T-47D, SK-BR-3, JAR, OVCAR-3, and human adipose stromal cells) was examined by primer-directed RT-PCR analyses. These studies provide a basis for further evaluation of the control mechanism of aromatase expression and estrogen biosynthesis in breast tumors.

Adipose Tissue↗

Localized cutaneous infection caused by Mycobacterium avium complex in an AIDS patient.

Although infection due to Mycobacterium avium complex (MAC) has long been recognized, it was not until the current AIDS epidemic that isolation of these mycobacteria became common in microbiology laboratories. The disseminated form of the disease is the commonest type. Localized disease as the first manifestation of MAC infection is a rare finding among these patients. Herein we report a case of localized cutaneous infection due to MAC in an AIDS patient.

AIDS-Related Opportunistic Infections↗

Cutaneous tuberculosis: a clinical, histopathologic, and bacteriologic study.

BACKGROUND: In recent years cutaneous infections with Mycobacterium tuberculosis with an atypical clinical appearance have become more common because of the increasing number of immunocompromised patients. OBJECTIVE: We report the clinical, histopathologic, and bacteriologic data of 11 patients with several forms of cutaneous tuberculosis seen during the past 14 years. METHODS: Patients from whom M. tuberculosis was isolated from culture of skin biopsy specimens, sinus drainage, or material aspirated from cutaneous abscesses were included. In all but two patients a biopsy specimen was obtained for histopathologic study. All but one patient received combined antituberculous therapy. RESULTS: The clinical diagnoses were scrofuloderma (four cases), cutaneous miliary tuberculosis (two), lupus vulgaris (two), tuberculous gumma (two), and one unclassified. All but three patients had evidence of either previous or simultaneous tuberculous foci other than in the skin. Histopathologic findings varied according to the type of cutaneous tuberculosis. CONCLUSION: In some patients with cutaneous tuberculosis, lesions are atypical in appearance because of immunodeficiency. Culture for M. tuberculosis should be performed in all suspected cases, even in those in whom special stains for acid-fast bacilli are negative.

Abscess↗

Identification of three novel mutations in the gene for Cu/Zn superoxide dismutase in patients with familial amyotrophic lateral sclerosis.

About 10% of cases of amyotrophic lateral sclerosis (ALS), a paralytic disorder characterized by death of motor neurons in the brain and spinal cord, exhibit autosomal dominant inheritance. A subgroup of these familial cases are caused by mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1). We report here three additional mutations occurring in the SOD1 gene in three families with ALS. Two of these changes are missense mutations in exon 5 of the SOD1 gene, resulting in leucine 144 to serine and alanine 145 to threonine substitutions. The third, a single base pair change in intron 4 immediately upstream of exon 5, results in an alternatively spliced mRNA. The alternate transcript conserves the open reading frame of exon 5, producing an SOD1 protein with three amino acids inserted between exons 4 and 5 (following residue 118). These three mutations bring to 29 the total number of distinct SOD1 mutations associated with familial ALS.

Adult↗

Surgical wound infections due to Propionibacterium acnes: a study of 10 cases.

Ten cases of surgical wound infection in which Propionibacterium acnes was probably the aetiologic agent were reviewed; in five the organism was isolated in pure culture. Six patients underwent a neurosurgical procedure. The average time for development of infection was 17.5 days (range 1-30 days). All patients were cured by surgical drainage and, in nine cases, with appropriate antimicrobial therapy. In conclusion, P. acnes must be considered as a cause of surgical wound infections especially after neurosurgery.

Adult↗

Isolation of Propionibacterium acnes from central nervous system infections.

Propionibacterium acnes is a common skin colonizer and its involvement in central nervous system (CNS) infections may be related with previous neurosurgical procedures. P. acnes was isolated in pure or mixed cultures from ten patients with CNS infections during a 5-year period. The clinical presentation, treatment and outcome were retrospectively reviewed. Nine out of 11 patients had CNS infections after a neurosurgical procedure. The clinical presentation was: brain abscess (five patients), subdural or epidural empyema (four patients) and shunt meningitis (one patient). Three patients had also secondary meningitis. All patients received antibiotic therapy and all abscesses and empyemas were drained. The patient with shunt meningitis cured without catheter removal. Only one patient with a brain abscess by P. acnes died, but several months thereafter and as a consequence of a Gram-negative superinfection. P. acnes is a pathogen for the CNS and infections must be surgically managed under adequate antibiotic treatment.

Journal Article↗