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Biomedical subjects

A Rodríguez

Publications and source records attributed to A Rodríguez.

At least 109 records · Page 6Linked to original sources
PubMed2001

[Identification of Helicobacter pylori and associated gastric lesions].

In this study is presented a silver stain technique for Helicobacter pylori with ammoniacal silver carbonato of Del Río Hortega, in biopsies and surgical specimens embebbed in paraffine. This study was performed between 1999 to 2001, and 717 gastroscopics biopsies were observed, that included: 705 chronic gastritis (98.32%), 11 gastric carcinomas (1.53%), and 1 low-grade lymphoma (0.13%). It is important to note the low incidence of adenocarcinomas and lymphomas from 717 gastroscopic biopsies during the period of 1999-2001, only 11 carcinomas and 1 lymphoma. We added 28 retrospective studies of biopsies and surgical specimens. These latter group included 21 adenocarcinomas and 7 low-grade lymphomas. Hence, there were a total of 745 cases with: 705 chronic gastritis, 32 adenocarcinomas, and 8 low-grade lymphomas. In 705 chronic gastritis, 325 (46.10%) were associated with H pylori, and they were Chronic Superficial Gastritis of Mild (8.62%), Moderate (61.23%), and Severe (12.92%) intensity; and Follicular Gastritis in 17.23%. In a serie of 82 total Follicular Gastritis (82/705), H pylori was founded in 68.29% (56/82). This relative frequency of association between H pylori with Chronic Gastritis in general (46.10%), and with Follicular Gastritis in particular (68.29%), could be explain because: a--many gastroscopic biopsies did not became from antrum, site of H pylori growing. Or b--there was another etiologic factor without morphologic value. There is a clear evidence that H pylori is an important factor in the pathogenesis of these chronic gastritis, from primary Acute Gastritis occurred in children and young patients, to Chronic Superficial Gastritis, Follicular Gastritis, Atrophic Gastritis, intestinal metaplasia, and Peptic Ulcer present in adult patients. Adenocarcinomas were associated with moderate and severe Chronic Superficial Gastritis, Atrophic Gastritis, intestinal metaplasia, and moderate and severe dysplasias of glandular epithelium. H pylori was founded in only 35% of adenocarcinomas, probably related to the presence of atrophic gastritis associated with metaplastic/dysplastic changes, or necrotic tissues, which would possibly explain the absent of H pylori growing under these circumstances. Low-grade lymphomas (MALT-type), arise from lymphatic tissue of the mucosa, and were associated with chronic gastritis, atrophy, and intestinal metaplasia. H pylori was founded in 75% of all lymphomas. Also in this case, there is a clear pathogenic evidence between H pylori infection and the development of low-grade lymphoma, specially in early stages, since it is possible the complete resolution after antibiotic therapy or partial gastrectomy.

Adenocarcinoma↗
PubMed2000

Two hydrochlorides of 7-methyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),13,15-triene.

The X-ray structure determinations of the two title compounds, namely 7-methyl-7,17-diaza-3,11-diazoniabicyclo[11.3.1]heptadeca-1(17),13,15-triene dichloride monohydrate, C(14)H(26)N(4)(2+).2Cl(-).H(2)O, (I), and 7-methyl-17-aza-3,7,11-triazoniabicyclo[11.3.1]heptadeca-1(17),13,15-triene 2.826-chloride 0.174-nitrate, C(14)H(27)N(4)(3+).2.826Cl(-).0.174NO(3)(-), (II), are reported. Protonation occurs at the secondary amine N atoms in (I) and at all three amine N atoms in (II) to which the Cl(-) ions are linked via N-H.Cl hydrogen bonds. The macrocyclic hole is quite different in both structures, as is observed by comparing particularly the N3.N4 distances [2.976 (4) and 4.175 (4) A for (I) and (II), respectively]. In (II), a Cl(-) ion alternates with an NO(3)(-) ion in a disordered structure.

Journal Article↗
PubMed2000

Study of Ligand Substitution Reactions at Pentacyanoferrates(II) in Aqueous Salt and Micellar Solutions.

The ligand substitution reactions Fe(CN)(5)(4-(t)bupy)(3-) + 4-CNpy and Fe(CN)(5)(4-(t)bupy)(3-) + pzCO(2)(-) (4-(t)Bupy = 4-tert-butylpyridine; 4-CNpy = 4-cyanopyridine; pzCO(2)(-) = pyrazinecarboxylate) were studied in several aqueous salt and micellar solutions. Kinetic data in aqueous solutions showed that the two processes follow a dissociative mechanism, D, and the dependence of the first-order rate constants on [salt] on electrolyte aqueous solutions allow the estimation of the activation volumes corresponding to both reactions. Under true first-order conditions no kinetic micellar effects were found in anionic (SDS) and nonionic (Triton X-100) aqueous micellar solutions. In cationic micellar solutions (CTAB, CTAC, and TTAB) small kinetic micellar effects were found. These were related to the different ionic concentrations and the different polarity and structure of the Stern layer surrounding the cationic micellar aggregates, where the reactions take place, with respect to pure water. Copyright 2000 Academic Press.

Journal Article↗
PubMed2000

Nucleotide sequence and analysis of pBL1, a bacteriocin-producing plasmid from Lactococcus lactis IPLA 972.

The complete sequence of the 10.9-kbp bacteriocinogenic plasmid pBL1 from Lactococcus lactis subsp. lactis IPLA 972 has been determined. Thirteen ORFs were encountered, of which 5 were incomplete. pBL1 proved to be a narrow-host-range plasmid which replicates neither in Bacilus subtilis nor in Lactobacillus spp. The structural organization of the pBL1 replication region was highly similar to other well-known theta-replicating plasmids of lactococci, at both the untranslated (the replication origin) and the translated (repB and orfX) sequences. As in other plasmids, the product of orfX was not necessary for plasmid replication. However, it was shown to be involved in plasmid stability. Three genes organized in an operon-like structure encompassed, most likely, the bacteriocin-encoding region. Upstream of the origin of replication a nicking site (oriT) was found. This oriT sequence proved to be functional by mobilization of plasmids wearing it. One complete and several partial IS elements were identified on pBL1.

Amino Acid Sequence↗
PubMed2000

Combined versus sequential phacotrabeculectomy with intraoperative 5-fluorouracil.

PURPOSE: To determine and compare the intraocular pressure (IOP) lowering effects of single-incision combined phacoemulsification and trabeculectomy with phacoemulsification done after previous trabeculectomy, both with an intraoperative dose of 5-fluorouracil (5-FU). SETTING: Hospital Del Salvador Ophthalmology Service, Clínica Oftalmológica Pasteur, Santiago, Chile. METHODS: The effects on IOP after phacoemulsification in eyes with previous trabeculectomy using intraoperative 5-fluorouracil (5-FU) (Group 1, n = 18) were compared with those in a matched group of eyes having combined phacoemulsification and trabeculectomy, also with intraoperative 5-FU (Group 2, n = 22). The mean postoperative IOPs and survival curves for IOP values less than 20 mm Hg and 15 mm Hg or less were determined in both groups. Data were retrospectively collected. Comparisons were made with the paired Student t test, and survival curves were compared using log-rank analysis. RESULTS: Mean postoperative IOP without medications was 12.6 mm Hg in Group 1 and 12.2 mm Hg in Group 2 (P = .64). Group 2 had a significant postoperative decrease in IOP (P = .0575); Group 1 did not have a significant increase or decrease. There was no significant difference in the survival curves between groups using arbitrarily defined failure criteria: (1) IOP greater than 15 mm Hg or (2) IOP equal to or greater than 20 mm Hg, both without medication (log-rank analysis, P = .333 and P = 1.00, respectively). CONCLUSION: Combined cataract and glaucoma surgery with intraoperative 5-FU was associated with good long-term IOP control similar to that after phacoemulsification with intraoperative 5-FU in eyes with previous trabeculectomy.

Aged↗
PubMed2000

SmcL, a novel membrane-damaging virulence factor in Listeria.

We describe here the fourth listerial membrane-damaging virulence factor, a sphingomyelinase C (SMase) that is produced specifically by the ruminant pathogen Listeria ivanovii. Its coding gene, smcL, is a monocistron expressed independently of PrfA. The smcL product, SmcL, is highly similar to the staphylococcal beta-toxin and is responsible for the differential hemolytic properties of L. ivanovii (bizonal hemolysis and CAMP-like reaction with R. equi). The role of SmcL in virulence was assessed by gene disruption and complementation. Our data show that SmcL mediates disruption of the membrane of primary phagosomes, thereby promoting bacterial intracellular proliferation. They also suggest that SmcL may play a role in host tropism. smcL is located in LIPI-2, a novel 18-kb pathogenicity island which also contains a cluster of internalin genes. LIPI-2 is unstable, L. ivanovii-specific and required for full virulence in mice and lambs.

Amino Acid Sequence↗
PubMed2000

CCR5 (chemokine receptor-5) DNA-polymorphism influences the severity of rheumatoid arthritis.

Chemokines are critical for the inflammatory process in autoimmune diseases such as rheumatoid arthritis (RA). The chemokine receptor-5 (CCR5) mediates chemotaxis by CC-chemokines and is expressed by lymphocytes with the Th1 phenotype and monocyte/macrophages. A 32 bp deletion in the CCR5 (CCR5-delta 32 allele) abolishes receptor expression in homozygotes, while CCR5-delta 32 carriers would express less receptor than wild-type homozygotes. This polymorphism is related to the resistance to HIV-1 infection and progression towards AIDS. We hypothesized that the CCR5-delta 32 allele may modulate the severity of disease in RA. A total of 160 RA-patients (71 and 89 with severe and non-severe phenotypes, respectively) and 500 healthy individuals from the same Caucasian population (Asturias, northern Spain) were genotyped. Carriers of the CCR5-delta 32 allele were at a significantly higher frequency (P = 0.012) in non-severe compared to severe patients (17% vs 4%). Our results suggest that the CCR5-delta 32 polymorphism is a genetic marker related to the severity of RA.

Arthritis, Rheumatoid↗
PubMed2000

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↗
PubMed2000

Sterol carrier protein 2 gene transfer changes lipid metabolism and enterohepatic sterol circulation in mice.

BACKGROUND & AIMS: Sterol carrier protein 2 (SCP-2) enhances sterol cycling and facilitates cholesterol translocation between intracellular organelles and plasma membrane in cultured cells, including hepatocytes. We examined the role of SCP-2 in hepatic cholesterol and lipid trafficking through the sinusoidal and canalicular secretory pathways of the liver in vivo. METHODS: Recombinant adenovirus-mediated SCP-2 gene transfer was used to obtain hepatic overexpression of SCP-2 in C57BL/6 mice. RESULTS: SCP-2 overexpression in the mouse liver resulted in an 8-fold increase of SCP-2 protein levels and determined various effects on lipid metabolism. It decreased high-density lipoprotein cholesterol and increased low-density lipoprotein (LDL) cholesterol concentrations. The expressions of hepatic LDL receptor, apolipoprotein (apo) A-I, apoB, and apoE were decreased. SCP-2 overexpression also increased hepatic cholesterol concentration, associated with decreased cholesterol neosynthesis. Increased biliary cholesterol and bile acid secretion, bile acid pool size, and intestinal cholesterol absorption were also observed. CONCLUSIONS: These results indicate that modulation of SCP-2 expression in the liver determines important modifications on lipoprotein metabolism, hepatic cholesterol synthesis and storage, biliary lipid secretion, bile acid metabolism, and intestinal cholesterol absorption.

Animals↗
PubMed2000

Primary idiopathic chylopericardium in a 2 month old successfully treated without surgery.

The authors report a case of primary idiopathic chylopericardium in a previously healthy 2-month-old infant. He was treated with continuous pericardial drainage and low-fat total parenteral nutrition. He remains asymptomatic after 14 months of follow-up. This is the first report of primary idiopathic chylopericardium successfully treated nonoperatively.

Drainage↗
PubMed2000

Homeostasis of REM sleep after total and selective sleep deprivation in the rat.

During specific rapid eye movement (REM) sleep deprivation its homeostatic regulation is expressed by progressively more frequent attempts to enter REM and by a compensatory rebound after the deprivation ends. The buildup of pressure to enter REM may be hypothesized to depend just on the time elapsed without REM or to be differentially related to non-REM (NREM) and wakefulness. This problem bears direct implications on the issue of the function of REM and its relation to NREM. We compared three protocols that combined REM-specific and total sleep deprivation so that animals underwent similar 3-h REM deprivations but different concomitant NREM deprivations for the first 2 (2T1R), 1 (1T2R), or 0 (3R) hours. Deprivation periods started at hour 6 after lights on. Twenty-two chronically implanted rats were recorded. The median amount of REM during all three protocols was approximately 1 min. The deficits of median amount of NREM in minutes within the 3-h deprivation periods as compared with their baselines were, respectively for 2T1R, 1T2R, and 3R, 35 (43%), 25 (25%), and 7 (7%). Medians of REM rebound in the three succeeding hours, in minutes above baseline, were, respectively, 8 (44%), 9 (53%), and 9 (50%), showing no significant differences among protocols. Attempted transitions to REM showed a rising trend during REM deprivations reaching a final value that did not differ significantly among the three protocols. These results support the hypothesis that the build up of REM pressure and its subsequent rebound is primarily related to REM absence independent of the presence of NREM.

Animals↗
PubMed2000

[Fulminant streptococcus infection of soft tissue].

BACKGROUND: In recent years there has been an apparent increase in severe infections produced by group A beta-hemolytic Streptococci in developed countries. Necrotizing fascitis and myositis are two rare but fearsome complications caused by this microorganism. METHODS: Two cases of fulminant soft tissue infection recently observed in the authors' center are presented and the clinical presentation and differential diagnosis commented upon. RESULTS: The first case was a necrotizing fascitis at a surgical wound which appeared following a gynecological surgery. The second case reports gluteal myositis following intramuscular injection. In both cases the evolution was disastrous. CONCLUSIONS: Streptococcus pyogenes may produce fulminant infections in patients without underlying disease either spontaneously or following minimum traumas. The most frequent involvement is of the soft tissues. This virulence at a local tissue and systemic level has been associated with the production of exotoxin.

Diagnosis, Differential↗
PubMed2000

A DNA polymorphism at the alpha2-macroglobulin gene is associated with the severity of rheumatoid arthritis.

OBJECTIVE: To determine if DNA polymorphisms at the alpha2-macroglobulin (alpha2m) and angiotensin converting enzyme (ACE) genes were associated with rheumatoid arthritis (RA). METHODS: A total of 160 patients (71 with early active severe RA, 89 with non-severe RA) were genotyped (polymerase chain reaction) for the alpha2m (5 bp deletion/insertion) and ACE (I/D) polymorphisms. We also genotyped 500 healthy controls from the same Caucasian population (Asturias, Northern Spain). RESULTS: Carriers of the alpha2m deletion allele were at a significantly higher frequency among patients with an early active severe form of the disease, compared to patients with non-severe RA (p = 0.037). The frequency of the alpha2m deletion allele was significantly higher in patients with severe compared to nonsevere RA (p = 0.017). In addition, the frequency of the deletion allele was significantly higher among patients with 5 or more episodes of acute exacerbation of disease activity per year (n = 39) compared to those with none (n = 46) (p = 0.002). Gene and genotype frequencies for the ACE-I/D polymorphism did not differ between those with early active severe and non-severe RA. CONCLUSION: The genetic variation at alpha2m is associated with the severity of RA. Carriers of the alpha2m deletion allele would have increased risk of developing an early active severe form of the disease. Our data suggest that alpha2m could be a valuable target in the treatment of RA.

Arthritis, Rheumatoid↗
PubMed2000

[Determination of anti-HC in relatives of carriers as a way of detecting new cases].

A matter of interest is still knowing the disease in carriers of HVC among relatives. We studied 270 relatives of carriers of HVC. In only 3 cases the serology was (+). We did not found differences between our results and what was published. This could mean that the differences were not due only too transfusional transmission and could exist others possibilities.

Argentina↗
PubMed2000

[Morphology of the cells in myxoid tumors].

We describe a morphologic study of myxoid cells in myxoid tumors or with myxoid regions: myxoid fibrosarcoma, myxoma, myxoid liposarcoma, embryonal rhabdomyosarcoma, chondroma, chondrosarcoma, myxoid leiomyosarcoma, schwannoma, and odontoameloblastoma; and we compare with fibroblasts of umbilical cord, embryonal mesenquima and loose connective tissue in inflammatory conditions. Histologic techniques: H-E, PAS, Masson's trichrom, and Del Río Hortega's panoptic silver staining. Histologically Del Río Hortega's technique reveals bipolar fibroblasts with long processes. In myxoma and myxoid fibrosarcoma they are stellated with abundant processes and mucin cytoplasm secretion contained in bowls that slides through cytoplasmic expansions and discharge into intercellular space. The lipoblasts of myxoid liposarcoma are also stellated with abundant processes and contain drops of lipids. The rhabdomyoblasts are raquetoid cells with cross striated cytoplasm, myofibrils and cigar-shaped nuclei. Schwannomas are composed of spindle and bipolar cells with long and thin cytoplasmic extensions. The chondroblasts in chondromas and chondrosarcomas have wide cytoplasm with short processes. The odontoblasts in odontoameloblastomas have wide cytoplasm and long processes directly extended toward adjacent dentinal. These morphologic details can help in the differential diagnosis associated with immunoperoxidase stains.

Adolescent↗