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Biomedical subjects

J Linares

Publications and source records attributed to J Linares.

At least 19 recordsLinked to original sources

A positive association of peripheral arterial occlusive disease (PAD) and Chlamydophila (Clamydia) pneumoniae.

The relationship between Chlamydophila pneumoniae (Cp) infection and peripheral arterial occlusive disease (PAD) was studied by analyzing clinical samples from 95 patients with PAD and 100 controls. The following investigations were conducted: IgG and IgA against lipopolysaccharide (LPS) and against purified Cp-specific antigens from elementary bodies (EB) with ELISA; anti-EB IgG, with MIF; Cp DNA in arterial biopsy and peripheral blood mononuclear cells with heminested PCR; LPS with ELISA; and bacteria culture in HEp-2 cells from arterial biopsy. A significantly higher ratio of anti-EB IgG was detected in patients. There were no significant differences in anti-LPS IgG, anti-LPS IgA and anti-EB IgA between cases and controls. Cp DNA findings in the vascular wall biopsy showed significant differences between cases and controls. We obtained results that significantly involve Cp infection with PAD through the detection of anti-EB IgG from serum and bacterial DNA from arterial biopsy.

Aged↗

A new microimmunofluorescence test for the detection of Chlamydia pneumoniae specific antibodies.

To evaluate a microimmunofluorescence (MIF) test (Chlamydia pneumoniae IgG, Vircell, Spain) that detects IgG against Chlamydophila pneumoniae (Cp), MRL Diagnostics MIF was used as reference test. Cross-reactivity against Chlamydia trachomatis (Ct) and Chlamydophila psittaci (Cps) was investigated. Eighty sera were analysed from 22 subjects with vascular disease, 38 with multiple sclerosis and 20 healthy individuals. Vircell and MRL MIF tests assessed 58.75% and 60% of the samples as positive, respectively, and their results coincided (positive/negative) in 98.75% of samples. One major (>1 IgG titre) and 32 minor (1 titre) discrepancies were observed. Correlation between tests was significant. Vircell MIF test demonstrated 97.9% sensitivity and 100% specificity. Differences in simultaneous reactivity to Ct and Cps between the tests were not significant. Vircell MIF test showed a good performance to detect the IgG against Cp.

Adult↗

Role of apolipoprotein E epsilon 4 allele on chronic allograft nephropathy after renal transplantation.

Lipid abnormalities may contribute to chronic allograft nephropathy (CAN). Apolipoprotein E (ApoE) gene polymorphism regulates lipoprotein metabolism, but little is known about an association between CAN and this polymorphism. The ApoE gene (E3/E4) polymorphism was typed by PCR assay (99 E3/E3, 28 E3/E4, 1 E4/E4) on 128 consecutive renal transplant patients with functioning grafts for more than 3 years (6.7 +/- 2.8 years). Twenty-eight patients with histological CAN were compared with 100 patients who had no clinical evidence of chronic rejection (no proteinuria and sCr < 2.5 mg%). As expected, univariate analysis revealed that patients with CAN experienced a greater acute rejection rate (78% vs 21%; P=.001), a higher serum creatinine (3.6 +/- 1.7 vs 1.4 +/- 0.5 mg%; P=.0001), and an older organ donor (43 +/- 20 vs 29 +/- 13 years; P=.0001). The lipid profiles (total cholesterol and triglycerides levels) were similar in both groups with 60% in each group receiving anti-lipemic drugs. Interestingly, the ApoE epsilon 4 allele was overrepresented in the group with CAN (39% vs 17%, P=.019). Logistic regression analysis showed that the epsilon 4 allele was an independent predictor of CAN (OR: 3.4; CI 95%: 1.07 to 11; P=.040) as were donor age and acute rejection episodes. In conclusion, an interaction between risk factors and genetic factors may determine CAN in this population. This finding may help to target prophylactic interventions in these recipients.

Adult↗

Regression of left ventricular hypertrophy by lisinopril after renal transplantation: role of ACE gene polymorphism.

BACKGROUND: Cardiac complications are the main cause of death in renal transplantation (RT), and left ventricular hypertrophy (LVH) may play an important role in these patients. The unfavorable genotype of the angiotensin-converting enzyme (ACE) gene has been associated with cardiovascular disease, including LVH. ACE inhibitors (ACEIs) reduce LVH, but little is known about the effects of ACEIs on LVH in RT patients with different insertion/deletion (I/D) genotypes of the ACE gene. METHODS: We prospectively studied 57 stable nondiabetic RT patients with hypertension and echocardiographic LVH as well as a functional graft for 69.5 +/- 5.6 months. Patients randomly received either lisinopril 10 mg/day (group A, N = 29; 5 were excluded due to reversible acute renal failure) or placebo (group B, N = 28) for 12 months. Echocardiography (M-mode, 2-B, and color flow Doppler) was performed at baseline and 6 and 12 months later by the same examiner without previous knowledge of the genetic typing. The ACE genotype (I or D alleles) was ascertained by polymerase chain reaction (PCR; group A, DD = 10 and ID/II = 14; group B, DD = 15 and ID/II = 13). RESULTS: All patients maintained a good renal function (serum creatinine <2.5 mg/dL) during the follow-up and both groups received a similar proportion of antihypertensive drugs (beta-blockers 83 vs. 79%; Ca antagonists 66 vs. 68%; alpha1-adrenoreceptor antagonists 50 vs. 67%) during the study. As expected, mean arterial blood pressure and hemoglobin levels showed a higher percentage reduction in group A versus group B (-4 +/- 2.8 vs. 2.1 +/- 2.6%, P = 0.07, and -11.5 +/- 1.5 vs. -0.5 +/- 2.3%, P < 0.01, respectively). Group A patients showed a significantly higher decrement in LV mass index (LVMI) than group B at the end of follow-up, after adjusting for age, baseline LVMI, time after grafting and changes in systolic blood pressure, renal function, and hemoglobin levels (group A, -9.5 +/- 3.5% vs. group B, 3 +/- 3.2%, P < 0.05). As a result, 46% of group A and only 7% of group B patients showed a reduction of LVMI >/=15% (P < 0.01). The beneficial effect of lisinopril on LVMI reduction was more evident in DD patients (placebo DD, 8.4 +/- 4.1% vs. lisinopril DD, -7.2 +/- 5.3, P < 0.05), and a trend was observed in patients with other genotypes (placebo ID/II, 2.8 +/- 5.4% vs. lisinopril ID/II, -11.4 +/- 5%, P = 0.33). CONCLUSIONS: Lisinopril decreases LVM in renal transplant patients with hypertension and LVH, and the ACE gene polymorphism may predict the beneficial effect of this therapy. This finding may be important in targeting prophylactic interventions in this population.

Acute Kidney Injury↗

Interleukin-7, a non-redundant potent cytokine whose over-expression massively perturbs B-lymphopoiesis.

Interleukin-7, originally described as a factor controlling the survival of B-cell progenitors, has been shown by gene knock-out technology to be a non-redundant cytokine. Of all single cytokine knock-out mice, those in which the IL-7 gene has been ablated show a profound defect in lymphocyte development. Likewise, mice in which signals emanating from the corresponding receptor, whether it be by ablation of the unique alpha or common gamma chain of the receptor, or by interference with downstream signalling elements generated by this receptor complex, also show profound defects in lymphocyte differentiation. Transgenic mice over-expressing the IL-7 gene also show profound changes in lymphocyte development which, in some instances can result in the development of lymphoid tumours. Here, we review some of these aspects of IL-7 biology with particular reference to an IL-7 over-expressing transgenic mouse line in which the IL-7 transgene is controlled by the mouse MHC class II promoter.

Animals↗

Gastric mucosa abnormalities and tumorigenesis in mice lacking the pS2 trefoil protein.

To determine the function of the pS2 trefoil protein, which is normally expressed in the gastric mucosa, the mouse pS2 (mpS2) gene was inactivated. The antral and pyloric gastric mucosa of mpS2-null mice was dysfunctional and exhibited severe hyperplasia and dysplasia. All homozygous mutant mice developed antropyloric adenoma, and 30 percent developed multifocal intraepithelial or intramucosal carcinomas. The small intestine was characterized by enlarged villi and an abnormal infiltrate of lymphoid cells. These results indicate that mpS2 is essential for normal differentiation of the antral and pyloric gastric mucosa and may function as a gastric-specific tumor suppressor gene.

Adenoma↗

Spread and maintenance of a dominant methicillin-resistant Staphylococcus aureus (MRSA) clone during an outbreak of MRSA disease in a Spanish hospital.

It was not until November 1989 that the 1,000-bed University-affiliated Hospital de Bellvitge "Princeps d'Espanya" in Barcelona first acquired methicillin-resistant Staphylococcus aureus (MRSA). Since that time, the outbreak of MRSA disease has continued. We have analyzed by genomic DNA fingerprinting 189 MRSA isolates collected between late 1989 and the end of 1993. The isolates include both invasive and colonizing strains as well as isolates from health-care workers and environmental sources. In addition, 52 clinical isolates of methicillin-susceptible S. aureus (MSSA) collected in the same hospital were also analyzed. Isolates were classified into clonal types on the basis of molecular typing techniques. A single MRSA clone (I::B::a) belonging to ClaI type I, pulsed-field gel electrophoretic pattern B, and Tn554 pattern a was responsible for the great majority of infections (73% of blood cultures and 79% of specimens from other clinical sources). This clone appeared at the very beginning of the outbreak, spread throughout the hospital wards, and was also carried by inpatients and health-care workers and on environmental surfaces. In contrast, no dominant lineage was apparent among MSSA isolates (33 distinct pulsed-field gel electrophoretic patterns among 52 isolates). Two MSSA isolates seem to have originated from the dominant clone by deletion of the mecA gene and some additional DNA. In several isolates, different mecA polymorphs were present in identical chromosomal backgrounds or cells with distinct chromosomal backgrounds carried the same mecA polymorph, suggesting horizontal transfer of the mecA gene.

Adult↗

Myxoid change in decidualized scar endometriosis mimicking malignancy.

A case of cesarean scar endometriosis with massive decidualization is presented. The 25-year-old patient had an extensive, ulcerated lesion that mimicked malignancy microscopically due to myxoid change with alveolar patterns reminiscent of some soft tissue sarcomas, signet ring-like cells similar to mucin-producing carcinoma, and pseudoinfiltration of the fascia. The myxoid tissue was positive for acid mucopolysaccharides but negative with PAS. Decidual cells were vimentin positive and keratin negative. No atypia or mitoses were seen. The pseudoinfiltrative aspect was due to abundant extracellular matrix that separated the fascicles of the fascial tissue. There was a metaplastic decidual "proximity effect" in the surrounding, unaffected dermis, which may be responsible for the expansile features of the lesion. This case exemplifies the differential diagnosis of myxoid endometriosis with malignant conditions of the skin.

Abdomen↗

[Seroprevalence of antibodies against Plasmodium falciparum in volunteer donors from various cities in Venezuela].

The prevalence of antibodies to Plasmodium falciparum was studied in 890 blood donors from different geographical areas of Venezuela. The overall prevalence, as established by ELISA, was (1.7%). Seropositivity was higher in those samples obtained in Sucre (2.5%) and Apure (1.7%) states both with foci of malaria transmission. It is proposed that medical history should be reinforced by screening antimalarial antibodies in donors at risk.

Animals↗

Pseudomyxoma peritonei et ovarii associated with sequential ovarian and appendicular tumors and acromegaly.

Pseudomyxoma peritonei associated with highly differentiated mucinous, intestinal-type ovarian tumor is reported in a 46-year-old acromegalic patient. Five years after its discovery a second operation revealed a mucinous cystadenoma of the appendix. The coexistence of pseudomyxoma peritonei with ovarian and appendicular tumors is rare, raising questions about the primary was origin of the peritoneal tumor. In this case the primary was ovarian while the appendicular tumor occurred later. Since acromegaly is associated with a high risk for the development of colorectal tumors, it could also have elicited a similar response in the intestinal-type ovarian tumor and the appendicular neoplasm found in this patient. The role of appendectomy in the surgical treatment and staging of ovarian tumors is stressed.

Acromegaly↗

[Preservation of blood platelets concentrates at different temperatures].

The temperature storage of the platelet concentrates (PC) it's of utmost importance in order to preserve the viability and the hemostatic function of the platelets. In the following study we made a comparative evaluation of the PC stored at three different temperatures: Volume, platelet count, pH, pCO2, pO2, in vitro aggregation, bacterial growth, ultrastructure changes and survival, to test its quality and usefulness. The results provide evidence that the PC kept at 27 degrees C showed marked differences compared with the PC stored at 22 degrees C. For example, the platelets showed the strongest morphological changes, less survival and probably a higher metabolic activity than those kept at 22 degrees C. Although the in vitro function was altered, it was recovered after 90 minutes of incubation with fresh frozen plasma. According with these results we can conclude that the in vivo hemostatic activity of these PC is as efficient as those stored at 4 and 22 degrees C, but due to the decreased of the in vivo platelet survival, we support that the 22 degrees C remain as the best temperature for the PC storage.

Adult↗

Intravenous ciprofloxacin therapy in severe infections.

Fifty evaluable patients (34 men and 16 women; mean age, 47 years) with severe infections were given intravenous ciprofloxacin (200 mg every 12 hours) for a mean of 14 days. Therapy was continued with oral ciprofloxacin 500 to 750 mg every 12 hours in 34 cases for a mean of 57 days. The sources of the infections were bone and joint (26 patients), respiratory tract (10 patients), urinary tract (four patients), soft tissue (four patients), abdominal (three patients), bacteremia of unknown origin (two patients), and right-sided endocarditis (one patient). Fifteen patients (30 percent) were bacteremic. Causative organisms included Pseudomonas aeruginosa (32 patients), other gram-negative bacilli (18 patients), and gram-positive cocci (nine patients). Minimal inhibitory concentrations ranged between 0.03 and 1 microgram/ml. Mean peak serum concentrations were 1.58 micrograms/ml (intravenous) and 2 micrograms/ml (oral); mean trough serum concentrations were 0.23 micrograms/ml (intravenous) and 0.32 micrograms/ml (oral). Serum bactericidal activity values achieved after intravenous and oral therapy were similar. Response to therapy was evaluated separately in patients with or without osteomyelitis. In 30 patients with infections other than osteomyelitis, clinical cure was achieved in 27 (90 percent), and therapy failure occurred in three patients. In the 20 remaining patients with osteomyelitis, 15 (75 percent) had a satisfactory response, with apparent cure after a mean follow-up of 11 months, whereas five had therapeutical failure (P. aeruginosa became resistant in four of them). Overall, no major adverse effects were encountered. Superinfection by a resistant P. aeruginosa was observed in three patients. Intravenous ciprofloxacin is an effective and safe agent for the therapy of severe infections caused by susceptible organisms.

Adolescent↗

Origin of the ultimobranchial body and its colonizing cells in human embryos.

The early development of the ultimobranchial body and its colonizing cells was studied in human embryos (O'Rahilly's stages 14 and 15). In our studies we have obtained evidence that permits us to propose a new hypothesis on the origin of both the ultimobranchial body and its colonizing cells. Based on our interpretation of the morphogenetic features in human development, we think that the ultimobranchial body derives from the fifth endodermal pharyngeal pouch, which is colonized, from O'Rahilly's stage 14 on, by cellular material of ectodermal placodial nature that originates in the most caudal portion of the epicardiac branchial placode.

Animals↗