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Biomedical subjects

A Ramos

Publications and source records attributed to A Ramos.

At least 19 recordsLinked to original sources

Self-limited autoimmune disease related to transient donor B cell activation in mice neonatally injected with semi-allogeneic F1 cells.

BALB/c mice injected at birth with 10(8) semi-allogeneic (C57BL/6 x BALB.IgHb)F1 spleen cells develop a lupus-like syndrome in which autoantibodies bear exclusively the donor allotype. We have analyzed the evolution of donor B cell chimerism and the autoimmune manifestations during the first year of life in these mice. Anti-DNA, -histone, and -cardiolipin IgG antibodies as well as circulating immune complexes appeared in the second week of life, reached the highest values around the sixth week, and then progressively dropped to normal values after the sixth month in most mice. The kinetics of the evolution of the autoimmune manifestations, as well as the kinetics of serum donor Ig allotype, were parallel to the kinetics of donor B cell chimerism, which was particularly prominent in the spleens in early weeks of life, and progressively decreased after remission of the autoimmune syndrome. Membrane-proliferative glomerulonephritis, which was followed as the more representative histological abnormality in this model, was particularly evident after 10 weeks of life, but disappeared by the end of the follow-up. Interestingly, when mice with a self-limited disease were re-injected with 10(8) F1 spleen cells i.v., a flare in the serological manifestations was observed. In these re-injected mice a predominance of anti-DNA, IgG1 antibodies bearing exclusively the donor allotype was also observed, as in the early weeks of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Di(1,N6-ethenoadenosine)5', 5'''-P1,P4-tetraphosphate, a fluorescent enzymatically active derivative of Ap4A.

Di(1,N6-ethenoadenosine)5',5'''-P1,P4-tetraphosphate, epsilon-(Ap4A), a fluorescent analog of Ap4A has been synthesized by reaction of 2-chloroacetaldehyde with Ap4A. At neutral pH this Ap4A analog presents characteristics maxima at 265 and 274 nm, shoulders at ca 260 and 310 nm and moderate fluorescence (lambda exc 307 nm, lambda em 410 nm). Enzymatic hydrolysis of the phosphate backbone produced a slight hyperchromic effect but a notorious increase of the fluorescence emission. Cytosolic extracts from adrenochromaffin tissue as well as cultured chromaffin cells were able to split epsilon(Ap4A) and catabolize the resulting epsilon-nucleotide moieties up to epsilon-Ado.

Adrenal Medulla

The clinical presentation of acute myocardial infarction predicts the severity of the lesion in the infarct-related artery.

The purpose of this study was to correlate the clinical presentation of acute myocardial infarction with the patency rate and degree of residual stenosis of the infarct-related artery. One hundred and forty-five patients who underwent angiography after acute myocardial infarction were divided into two groups according to the time of onset of anginal pain prior to infarction. Group A comprised 119 patients, (109 men, 10 women, aged 53 +/- 9 years) who did not experience any symptoms before infarction or with anginal pain of less than 5 days preceding myocardial infarction, and group B 26 patients (all men, aged 54 +/- 12 years) with previous stable angina for greater than or equal to 1 year. Twenty-two days after acute myocardial infarction, 68 of the 145 patients (47%) had a patent infarct-related artery: 64 patients in group A (54%) and four patients in group B (15.4%) (P less than 0.006). Furthermore, 19 patients in group A (16%) and none in group B had less than 70% stenosis in the infarct-related artery (P less than 0.02). The mean residual stenosis in group A was 83.3 +/- 27% whereas in group B it was 98.1 +/- 4% (P less than 0.001). These results indicate that a long-standing history of angina before acute myocardial infarction is often related to a severe pre-existing atheromatous obstruction, which would account for the higher incidence of total coronary occlusion observed in group B. Thus angina of recent onset preceding acute myocardial infarction is associated with a higher patency rate of the infarct-related artery and frequent less than 70% residual lesions.

Adult

Differential staining of mucin granules from epoxy resin sections by a phosphotungstic acid-methyl green procedure.

After treatment of epoxy resin semithin sections from glutaraldehyde fixed rat large intestine with 5% aqueous phosphotungstic acid (PTA), staining with unpurified 0.2% solutions of methyl green at 60 C for 5 min produces a color differentiation between mucin granules of goblet cells. Some mucin granules and the glycocalyx appear deep green while the remaining granules, luminal mucin and collagen fibers are pink. The known contamination of unpurified methyl green with crystal violet seems to be responsible for the pink staining reaction of the latter structures, which also present an orange-red fluorescence under green exciting light. Electron microscopic observations show selective contrast of mucin granules which appear with a different amount of PTA deposits. This procedure is useful to reveal the heterogeneity of mucin granules in light and electron microscopy.

Animals

An immunogenetically defined and immunodominant Trypanosoma cruzi antigen.

Two strains of mice, A. SW (H-2s) and A.CA (H-2f), were immunized with live trypomastigotes or epimastigotes of the Tulahuen strain of Trypanosoma cruzi or with their sonicates. By immunowestern blotting, sera from A.SW mice, but not from A.CA, recognized, in an immunodominant fashion, a 45 kDal polypeptide (Tc45) present in both epimastigotes and trypomastigotes. Since A.SW and A.CA strains are congenic for the major histocompatibility H-2 complex, recognition of Tc45 seems to be controlled by this genetic region or by gene(s) located in its immediate vicinity. Subcellular fractionation revealed that Tc45 is mainly present at the cytoplasmic compartment.

Animals

Seasonal changes in the levels of anti-Dirofilaria immitis antibodies in an exposed human population.

A prospective follow-up study to define seasonal changes in the level of anti-Dirofilaria immitis antibodies in an exposed human population in Western Spain was conducted. Specific antibodies were detected using an enzymelinked immunosorbent assay (ELISA). Ig M antibodies predominated in Summer, during maximal vector activity, while Ig G rose to a maximum in Winter. The sole risk factor associated with higher optical densities in the ELISA proved to be age, indicating that repeated exposure to the parasite is the rule. It is concluded that, for serodiagnosis the endemic or non-endemic nature of the geographical area and the season of the year should be considered to define the basal level of positivity, and that as well as Ig G, Ig M should always be determined.

Adolescent

Intestinal intussusception as a presenting feature of choledochocele.

Choledochocele is a rare form of choledochal cyst [1, 2]. Usually, it manifests clinically with epigastric pain of colic type, jaundice, and/or pancreatitis. Occasionally, a palpable mass may be found. We describe two cases of intestinal intussusception as a presenting feature of choledochocele.

Adult

Mouse bone marrow cytogenetic damage produced by residues of tequila.

Five concentrations (50-860 mg/kg) of residues obtained after distillation and lyophilization of commercial tequila were injected into mice for evaluation of chromosome aberrations, sister-chromatid exchanges, and proliferation kinetics in mouse bone marrow cells. Appropriate positive and negative controls were included. Our results showed significant dose-related increases of chromosomal aberrations starting at 50 mg/kg and for sister-chromatid exchanges at 430 mg/kg. Cellular proliferation kinetics showed no alterations. With these data we demonstrated that the residues of tequila are genotoxic in vivo.

Alcoholic Beverages

Enterotoxins and adhesins of enterotoxigenic Escherichia coli: are they risk factors for acute diarrhea in the community?

A cohort of 228 Mexican children less than 5 years old was followed during the enterotoxigenic Escherichia coli(ETEC) season. The incidence of ETEC diarrhea-associated and asymptomatic infections was determined, and E. coli strains isolated from stool samples were tested for heat-labile and heat-stable toxins and for expression of colonization factor antigens (CFA). Of the children, 61% had at least one ETEC infection. Children with ETEC isolated from stools were more likely to have diarrhea than were ETEC-free age-matched control children (odds ratio [OR] = 4.5; 95% confidence interval [CI] = 2.9-7.0). Strains carrying CFA/IV, CFA/I, or CFA/II were found in 23%, 18%, and 5% of ETEC infections, respectively. The risk of having diarrhea associated with a CFA-expressing versus a CFA-negative ETEC strain was the same (age-adjusted OR = 0.8; 95% CI = 0.4-1.6). These data should be considered in the development of a diarrhea vaccine containing only CFAs.

Adhesins, Escherichia coli

Non-lytic antibodies in H-2-controlled resistance to acute infection with Trypanosoma cruzi.

1. Resistance to acute Trypanosoma cruzi infection in mice is a polygenic character with a major factor linked to the murine major histocompatibility system (H-2). We found that F1 hybrids A.CA(H-2f)/B10.Br(H-2k) between two susceptible strains are strongly resistant. 2. Resistant B10(H-2b) and A.SW(H-2s) animals survived 60 or more days after an intraperitoneal injection of 10(4) Tulahuén strain blood trypomastigotes. The specific antibody response of these individuals increased continuously up to 100 days or more. Parasitemia reached a peak at day 8 in all strains. Thereafter, the number of blood parasites in resistant animals showed an irregular but persistent decrease. 3. Susceptible congenic B10.Br and A.CA animals showed lower levels of specific anti-T. cruzi antibodies and an increase in parasitemia until death. B10.Br mice died 14 to 20 days after infection. A.CA animals were extremely susceptible, showing a sharp and sustained increase in parasitemia starting on day 12, followed by death no later than day 15 post-inoculation. 4. We found a significant correlation between IgG levels present in serum of resistant mice from 20 days on and protection against acute death. Whole immune anti-T. cruzi serum or its purified IgG class fraction neutralized T. cruzi inocula in vitro as shown by a significantly increased survival of recipient susceptible A.CA mice. 5. This IgG protective effect is independent of the protective effect mediated by the terminal activation of the complement cascade, since the parasites were inoculated with heat-inactivated immune sera and both recipient (A.CA) and donor (A.SW) strains lack C5.

Animals

[Efficacy of the electrocardiographic diagnosis of left ventricular hypertrophy on the basis of gender].

STUDY OBJECTIVE: To determine the efficacy of electrocardiographic criteria of Left Ventricular Hypertrophy (RVL greater than 11 mm, SVE3 + RVL greater than 20 mm in females and greater than 28 mm in males, SV1 + RV6 or SV2 + RV5) in hypertensive patients according to sex. DESIGN: Retrospective study. Gold standard M mode echocardiography. SETTING: Pulido Valente Hospital Department of Cardiology (Lisbon). PATIENTS: 56 hypertensive patients (age 55.1 s.d. 11.6), 27 females and 29 males, with LVH by echocardiographic Left Ventricular Mass Index (LVMI) greater than 110 g/m2 in woman and greater than 134 g/m2 in men, respectively 10 and 19 patients. The LVMI was calculated by the formula of the American Society of Echocardiography modified by Devereux. RESULTS: The LVMI was smaller in females than in males (P = 0.007). The Cornell Criteria had the greatest efficacy in woman and the Sokolow criteria satisfactory efficacy but in man. The electrocardiogram (1 of the 4 criteria positive) had low diagnostic efficacy in woman. CONCLUSIONS: We concluded that echocardiogram is the best non-invasive diagnostic tool of Left Ventricular Hypertrophy in hypertensive females and is necessary to adjust and choose the electrocardiographic Left Ventricular Hypertrophy criteria according to sex.

Adult

The liver in autosomal dominant polycystic kidney disease. Implications for pathogenesis.

A histomorphometric and clinico-pathologic analysis of 26 autopsy cases of autosomal dominant polycystic kidney disease (ADPKD) showed that (1) the density of biliary microhamartomas (BMHs) and the stage of polycystic liver disease were strongly correlated, and (2) both were positively correlated with the stage of renal dysfunction and age at autopsy. Using multiple linear regression analysis, only the stage of renal dysfunction was significantly predictive of the density of BMHs, but both variables were simultaneously predictive for the stage of polycystic liver disease. On serial sections, 41.4% of cysts were connected to BMHs and 81.0% of BMHs to portal tracts. Bile-like material was found in 10.7% of BMHs. Flat or polypoid hyperplasia of the epithelium was observed in 2.7% of cysts. These results support the long-maintained view that hepatic cysts in ADPKD result from cystic dilatation of BMHs. They indicate, however, that the number of BMHs increases during life. These observations are consistent with the hypothesis that hepatic and renal cysts in ADPKD have similar pathogeneses, that BMHs and hepatic cysts result from hyperplasia of the bile duct epithelium, and that as they grow, the hepatic cysts become disconnected from the biliary ducts from which they are derived.

Adult

Intravenous ciprofloxacin and ceftazidime in serious infections. A prospective, controlled clinical trial with third-party blinding.

Oral ciprofloxacin has been shown to be effective in the treatment of infections due to gram-positive cocci and gram-negative rods. The efficacy and safety of intravenous ciprofloxacin was compared with that of intravenous ceftazidime in the treatment of 59 patients with well-documented serious infections in a prospective, controlled, randomized study with a third-party blinding. Thirty-three patients were treated with intravenous ciprofloxacin (200 mg every 12 hours, plus a daily extra placebo dose); 26 patients were treated with ceftazidime (1 g every eight hours). The severity of the infections, underlying diseases, and demographic features were comparable in both groups, although there were more men in the ciprofloxacin group. For ciprofloxacin/ceftazidime treatments, respectively, the evaluated infections were: pyelonephritis (16 patients/nine patients), pneumonia (three/five), soft-tissue infections (four/zero), spontaneous peritonitis (five/two), primary bacteremia (three/eight), and other (two/two). Isolated pathogens included: Escherichia coli (22/12), Klebsiella sp. (five/four), Pseudomonas aeruginosa (two/three), Haemophilus influenzae (one/one), Proteus mirabilis (two/zero), Proteus vulgaris (one/zero), Salmonella sp. (zero/two), Plesiomonas shigelloides (one/zero), and others (one/four). The clinical responses were cure or improvement in 31 ciprofloxacin cases/21 ceftazidime cases; failure, zero/four; and indeterminate, two/one. The bacteriologic responses were eradication in 28 ciprofloxacin cases/22 ceftazidime cases; persistence, one/three; and indeterminate, four/one. Mild intolerance occurred in three ciprofloxacin cases and two ceftazidime cases. A mild increase in serum hepatic enzymes was observed in two patients in each group. Superinfections occurred in five patients: enterococcal septicemia (zero/two) and urinary tract infections (one/two). The results presented suggest that intravenous ciprofloxacin is an effective and safe antimicrobial agent for the treatment of serious infections, with an efficacy comparable with that of ceftazidime, a broad-spectrum cephalosporin. An additional advantage seems to be a lower rate of superinfections.

Adolescent

[Effect of marked obesity on the emotional status of children].

Fifty children with overweight exceeding 50% of the expected weight were studied for establishing the occurrence of emotional disturbances caused by lack of acceptance by peers. Obese children were found to suffer often from discrimination by their schoolmates which was, in some degree, connected with their low fitness. This may lead to various emotional disturbances requiring even psychotherapeutic measures.

Adolescent

First stages of crystallization in a silicate glass: study by high-resolution electron microscopy.

The first stages of crystallization have been investigated for a glass in the system SiO2-Al2O3-Li2O with small amounts of titanium and zirconium as nucleating elements. The studies were performed by electron diffraction and electron microscopy in high-resolution mode. It has been found that the two phases forming the final glass ceramic crystallize successively. The first one gives small crystallites (less than 5 nm) randomly dispersed. The lattice plane images in several orientations are in good agreement with TiZrO4 crystal lattice. At 780 degrees C the average crystal size increases with increasing time of the heat treatments from 2.5 nm at 0.5 h to 4.5 nm at 2 h and then remains nearly constant. The crystallization of the second phase, a silicate solid solution with beta-quartz structure, occurs after complete crystallization of TiZrO4.

Ceramics

Renal involvement in leprosy.

Renal involvement in Hansen's disease was evaluated in 94 Portuguese patients, average age and duration of disease of 47.6 and 6.8 years respectively. Sixty-seven were studied retrospectively and 27 prospectively; renal biopsy was obtained in 4, fat-tissue needle aspiration for amyloidosis in 20, and tubular function was tested in ten. Mild proteinuria and/or haematuria was found in 33 patients, the severity increasing during erythema nodosum leprosum reactions, but without overt nephritic or nephrotic syndrome. Two patients had renal amyloidosis on biopsy and two more were confirmed by fat biopsy, a 10.5% incidence in those studied prospectively; all but one were of the lepromatous type, with frequent bouts of erythema nodosum leprosum. The two other renal biopsies showed mesangial glomerulonephritis, and one unexplained acute tubular necrosis; none had immune deposits by immunofluorescence. Proximal acidification was always normal, distal acidification tested by bicarbonate infusion was abnormal in one of nine patients, and six of nine patients had concentration defects. Leprosy causes frequent urinary sediment changes and concentration defects, usually without clinical expression; proteinuria and/or glomerular involvement is mainly due to amyloidosis.

Adolescent