Conjugal amyotrophic lateral sclerosis: suggestion for the implication of environmental factors.
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Amyotrophic Lateral Sclerosis↗
Biomedical subjects
A Calvo
Publications and source records attributed to A Calvo.
[Activity of different antimicrobial agents against penicillin-resistant Streptococcus pneumoniae].
Since the first strains of penicillin-resistant Streptococcus pneumoniae were isolated in the 1960s, the rate of resistance has increased world- wide, though with geographic variations. Currently, the prevalence and patterns of antibiotic resistance in this microorganism vary widely from one country to another, as well as within in the same country. In our study we evaluated the in vitro susceptibility of 299 isolates of S. pneumoniae from patients with community-acquired respiratory tract infections from 1998-2000 to different antimicrobial agents. The following resistance results were obtained: 32.11% to penicillin, 4.35% to amoxicillin, 3.68% to amoxicillin-clavulanic acid, 69.9% to cefaclor, 32.44% to cefpodoxime, 34.11% to cefuroxime, and 24.41% to azithromycin. For cefixime and ceftibuten there are no NCCLS breakpoint criteria.
Amoxicillin↗
[Activity of new fluoroquinolones against clinical isolates of Acinetobacter baumannii].
Acinetobacter baumannii is an opportunistic pathogen associated with numerous nosocomial infections. In recent years it has shown extraordinary ease in developing resistance to most antimicrobial agents, which is a serious problem as it makes these infections difficult to treat. We determined the in vitro activity of eight quinolones, five betalactam agents and colistin in 160 clinical isolates of A. baumannii. In general, we observed a high rate of resistance to the quinolones (90%), excluding clinafloxacin (25%), and to ampicillin-sulbactam (61.25%) and imipenem (50%). Colistin is the agent with least resistance (13.125%), although its toxicity limits its therapeutic use. Clinafloxacin may be a good option to treat A. baumannii infections, especially in cases of therapeutic failure with other antimicrobial agents.
Acinetobacter↗
The C3(1)/SV40 T-antigen transgenic mouse model of mammary cancer: ductal epithelial cell targeting with multistage progression to carcinoma.
The 5' flanking region of the C3(1) component of the rat prostate steroid binding protein (PSBP) has been used to successfully target the expression of the SV40 large T-antigen (Tag) to the epithelium of both the mammary and prostate glands resulting in models of mammary and prostate cancers which histologically resemble the human diseases. Atypia of the mammary ductal epithelium develops at about 8 weeks of age, progressing to mammary intraepithelial neoplasia (resembling human ductal carcinoma in situ [DCIS]) at about 12 weeks of age with the development of invasive carcinomas at about 16 weeks of age in 100% of female mice. The carcinomas share features to what has been classified in human breast cancer as infiltrating ductal carcinomas. All FVB/N female mice carrying the transgene develop mammary cancer with about a 15% incidence of lung metastases. Approximately 10% of older male mice develop anaplastic mammary carcinomas. Unlike many other transgenic models in which hormones and pregnancy are used to induce a mammary phenotype, C3(1)/Tag mice develop mammary tumors in the mammary epithelium of virgin animals without hormone supplementation or pregnancy. Although mammary tumor development appears hormone-responsive at early stages, invasive carcinomas are hormone-independent, which corresponds to the loss of estrogen receptor-alpha expression during tumor progression. Molecular and biologic factors related to mammary tumor progression can be studied in this model since lesions evolve over a predictable time course. Genomic alterations have been identified during tumor progression, including an amplification of the distal portion of chromosome 6 containing ki-ras and loss of heterozygosity (LOH) in other chromosomal regions. We have demonstrated that stage specific alterations in the expression of genes which are critical regulators of the cell cycle and apoptosis are functionally important in vivo. C3(1)/Tag mice appear useful for testing particular therapies since growth of the mammary tumors can be reduced using chemopreventive agents, cytokines, and an anti-angiogenesis agent.
Androgen-Binding Protein↗
Insulin-like growth factor-I reverts testicular atrophy in rats with advanced cirrhosis.
The pathogenesis of hypogonadism in cirrhosis is not completely understood. The levels of insulin-like growth factor-I (IGF-I), an anabolic factor with trophic actions on testes, are reduced in cirrhosis. This study was undertaken to evaluate whether rats with advanced cirrhosis develop hypogonadism and whether the administration of IGF-I exerts beneficial effects on testicular structure and function. Wistar rats with ascitic cirrhosis induced with CCl(4) were allocated into 2 groups (n = 10, each) to receive recombinant IGF-I (20 microg x kg(-1) x d(-1), subcutaneously) or vehicle for 3 weeks. Healthy rats receiving vehicle were used as the control group (n = 10). At baseline, both cirrhotic groups showed similar deterioration of liver function tests. Compared with controls, nontreated cirrhotic rats showed decreased serum levels of IGF-I (P <.05), reduced testicular size and weight (P <.001), and intense histopathological testicular abnormalities, including reduced tubular diameters (P <.001), loss of the germinal line (P <. 001), and diminutions in cellular proliferation, spermatogenesis (P <.001), and testicular transferrin expression (P <.001). In addition, low serum testosterone (P <.01) and high serum LH (P <.01) were present in untreated cirrhotic animals. Cirrhotic rats that received IGF-I showed full recovery of testicular size and weight and of all histopathological abnormalities (P <.001 to <.01 vs. nontreated cirrhotic rats; P = ns vs. controls). Serum levels of sex hormones tended to normalize. In conclusion, IGF-I deficiency may play a pathogenetic role in hypogonadism of cirrhosis. Low doses of IGF-I for a short period of time revert testicular atrophy and appear to improve hypogonadism in advanced experimental cirrhosis.
Animals↗
Influence of the number of layers on the equilibrium of a granular packing
This paper reports an experimental study on avalanches in a granular material contained in a confined geometry. The granular packing is made of monosize glass beads initially poured into a box that is slowly inclined until an avalanche takes place at a critical angle straight theta(M) (maximum angle of stability). The avalanche involves a decrease of the surface slope until a second critical angle straight theta(r) (angle of repose) is reached. Both angles and the mass displaced out of the box during the avalanche are studied as a function of the height of the granular packing. In order to avoid cohesion effects, experiments are carried out in a humidity controlled environment. For small packings, up to approximately ten layers, the stability of the system is significantly affected by the rough surface at the bottom. In contrast, for thicker systems, critical angles do not depend on the height.
Journal Article↗
Prevention of renal fibrin deposition in endotoxin-induced DIC through inhibition of PAI-1.
Plasminogen activator inhibitor-1 (PAI-1) increases in endotoxemia thus possibly cooperating in altering the hemostatic balance in a prothrombotic direction. The effect of the inhibition of PAI-1 with the monoclonal antibody MA-33B8 was studied systemically and in kidneys in a lapine model of endotoxin-induced disseminated intravascular coagulation (DIC). The increase in plasmatic PAI activity in the control group (n = 9) was inhibited in the MA-33B8 treated rabbits (n = 5). Control rabbits showed renal fibrin deposits, whereas only one of the MA-33B8 rabbits did so. These results were confirmed immunohistochemically in kidneys as PAI-1 immunostaining was seen inside the glomeruli and larger vessels in the control group, whereas MA-33B8 rabbits showed a remarkable decrease, demonstrating that MA-33B8 successfully inhibited PAI-1 in the kidneys as well. Therefore evidence for the important role of PAI-1 in fibrin generation in endotoxin-induced DIC is presented, suggesting that strategies aiming at its reduction can be useful in this pathology.
Animals↗
Characterization of the glycoconjugates of boar testis and epididymis.
Lectin histochemistry was used to perform in situ characterization of the glycoconjugates present in boar testis and epididymis. Thirteen horseradish peroxidase- or digoxigenin-labelled lectins were used in samples obtained from healthy fertile boars. The acrosomes of the spermatids were stained intensely by lectins with affinity for galactose and N-acetyl-galactosamine residues, these being soybean, peanut and Ricinus communis agglutinins. Sertoli cells were stained selectively by Maackia ammurensis agglutinin. The lamina propria of seminiferous tubules showed the most intense staining with fucose-binding lectins. The Golgi area and the apical part of the principal cells of the epididymis were stained intensely with many lectins and their distribution was similar in the three zones of the epididymis. On the basis of lectin affinity, both testis and epididymis appear to have N- and O-linked glycoconjugates. Spermatozoa from different epididymal regions showed different expression of terminal galactose and N-acetyl-galactosamine. Sialic acid (specifically alpha2,3 neuraminic-5 acid) was probably incorporated into spermatozoa along the extratesticular ducts. These findings indicate that the development and maturation of boar spermatozoa are accompanied by changes in glycoconjugates. As some lectins stain cellular or extracellular compartments specifically, these lectins could be useful markers in histopathological evaluation of diseases of boar testis and epididymis.
Acrosome↗
Age-related changes in the hamster epididymis.
Reproductive ability is decreased in aged animals and in men. Little is known about the changes taking place in the epididymis, and the possible influence on the loss of sperm quality. We studied the age-related alterations in the epididymis and in epididymal spermatozoa of hamsters. Adult (6-month-old), middle-aged (18-month-old), and aged (24-month-old) hamsters were used. Serum samples were obtained to determine testosterone levels. Testes and epididymides were removed and studied by light and electron microscopy. Epididymal sperm was also obtained and the motility, position of cytoplasmic droplet, and concentration were evaluated. Measurements of the height of the epithelium, length of stereocilia, external tubular diameter, and thickness of the muscular wall were performed. The proliferative activity was also studied. An ANOVA analysis was used to compare quantitative differences between epididymal zones and age groups. Aged hamsters presented involutive changes in the epididymis. A decrease in tubular diameter was found in cauda; principal cell ultrastructure showed changes including the appearance of damaged mitochondria, bundles of filaments, and the accumulation of lipofuscin. Some clear cells showed an unusual morphology by the presence of large electrondense vacuoles. A reduction in sperm quality was also observed, including a decrease in sperm motility and concentration, and alterations in the migration of sperm cytoplasmic droplet. Testosterone levels and cellular proliferative activity did not change. Aging causes a morphological alteration of hamster epididymis (mainly in the cauda), and a decrease in sperm quality.
Aging↗
Amyotrophic lateral sclerosis among the migrant population to Piemonte, northwestern Italy.
Recent surveys indicate a decreasing north-to-south gradient in the mortality and incidence rates of amyotrophic lateral sclerosis (ALS) in Italy, possibly indicating a different susceptibility to ALS in these populations. Piemonte, a region of northwestern Italy, experienced a considerable migration from other regions in Italy between 1940 and 1975; we therefore analyzed the effects of place of birth and migration upon the risk of developing ALS. Data on all ALS cases occurring in Piemonte during the period 1971-1990 were collected. Standardized incidence ratios (SIRs) for patients born outside Piemonte were calculated, using the Piemonte-born population as reference. A total of 962 ALS cases were identified during the study period, corresponding to a mean annual crude incidence rate of 1.37/100,000 population (95% confidence interval, 1.29-1.46). The SIRs of patients born in three southern Italian regions and of foreign-born persons were significantly higher than those of persons born in Piemonte and or other regions in Italy, and increased with age. This observation may be explained by an interaction between environmental and genetic factors or by selective migration.
Adult↗
Expression of adrenomedullin and proadrenomedullin N-terminal 20 peptide in human and rat prostate.
Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are two recently discovered hypotensive peptides translated from the same message transcript (preproAM mRNA). In this article we report the presence of AM, PAMP, and their mRNA in human and rat prostate and of AM receptor mRNA in rat prostate. PreproAM mRNA was found in the epithelium of normal human and rat prostate glands by in situ hybridization. In humans, it was mainly expressed in the basal cells. In rat, its expression was higher in the ducts than in the acini of all the prostate lobes. Immunocytochemistry identified a similar distribution pattern for AM compared with its mRNA but showed different locations for AM and PAMP immunoreactivity. The former was widespread in the epithelia, whereas the latter was almost exclusively found in neuroendocrine cells. In rat, Western blot analysis confirmed the presence of high levels of AM peptide in the ventral lobe and of its precursor in the ventral and dorsolateral lobes. Immunoreactivity for serotonin, chromogranin A, PAMP, and AM defined four subpopulations of prostate neuroendocrine-like cells in rat, a cell type that has not been previously described.
Adolescent↗
Self-administered joint counts in rheumatoid arthritis: comparison with standard joint counts.
OBJECTIVE: To test the reliability and validity of a self-administered 36 joint count developed after the Rapid Assessment of Disease Activity in Rheumatology (RADAR) questionnaire for assessing pain/tenderness. METHODS: Two self-administered formats (mannequin and text) were evaluated in 60 patients with rheumatoid arthritis (RA). Reliability between both formats was tested by Spearman rank correlation. Criterion validity/accuracy was tested by Spearman correlation coefficient between each self-report format and a joint count performed by a physician. Construct validity was ascertained by correlation of each format with other variables of disease activity. RESULTS: Reliability between the 2 formats was high (R = 0.94). Correlations between each format and the physician's joint count were also high (R = 0.77 for mannequin, 0.75 for text). Patients consistently rated their joint pain/tenderness higher than the physician (means 29, 27, and 12 for text, mannequin, and physician, respectively; p < 0.01). Construct validity of the text, mannequin, and physician formats compared with the modified Health Assessment Questionnaire showed R = 0.61, 0.65, 0.63; with Steinbrocker functional class R = 0.41, 0.46, 0.56; with pain R = 0.59, 0.61, 0.62; with global evaluation R = 0.66, 0.71, 0.84; and with morning stiffness R = 0.64, 0.59, 0.60, respectively. CONCLUSION: Although both self-administered formats exhibited adequate reliability and construct validity, a systematic difference between patient and physician/trained assistant performed joint counts was observed, with patients consistently rating their pain/tenderness higher. We thus do not believe they can replace standard physician/trained assistant evaluation in obtaining clinical research data in rheumatology.
Acute Disease↗
Mycoplasma pneumoniae antigen detection in Guillain-Barré syndrome.
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Antigens, Bacterial↗
[Chromosome anomaly and flow cytometry in gallbladder adenocarcinoma].
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Adenocarcinoma↗
Morphological and histochemical changes in the epididymis of hamsters (Mesocricetus auratus) subjected to short photoperiod.
The morphological involution and histochemical changes of the Syrian hamster (Mesocricetus auratus) epididymis induced by a short light period were investigated. Under short-day conditions, the epididymis showed marked morphological changes including a decrease in luminal diameter, disappearance of spermatozoa, increase of interductal tissue, increase of intraepithelial lipofuscin deposits, the presence of phagolysosomes in the principal cells and macrophage-like cells, and a considerable modification of most clear cells. With lectin histochemistry changes were found in the glycoconjugates of principal cells of the regressed epididymis, either a decrease (PNA, WGA, HPA and DBA) or an increase (MAA) in the affinity of lectins to the Golgi area, or a decrease (HPA) or an increase (PNA) in lectin binding to stereocilia. Both morphological and histochemical results showed that, under this light condition, the cauda epididymidis presented the most prominent alterations, and that the epididymis showed increased absorptive activity and a decreased synthesis of glycoproteins. All these changes are probably due to the decrease in testosterone levels.
Animals↗
[Risk factors for gallbladder cancer in Chilean females].
A case-control study of gallbladder cancer was conducted with 90 Chilean cases registered at one hospital in Santiago city, Chile from January, 1992 to August, 1994. Controls were selected among outpatients of the hospital who received abdominal echography. Each case was assigned 2 age- and sex-matched controls; either with or without gallstone(s). Study subjects were all directly interviewed by well-trained medical students. The present study focused on 74 female pairs and the following findings were obtained: 1) Odds Ratio(OR)s were significantly high for education years less than or equal to 6, body mass index greater than or equal to 24.0, constipation, and consumption of egg, fried meals, green and red chili. Chili pepper consumption of both types in cases showed significantly elevated risks with higher frequency. 2) While high ORs were observed, biliary symptoms such as dyspepsia and past history of cholelithiasis were strongly involved with present gallstone(s) and may not be independent factors for gallbladder cancer. 3) Significantly low ORs were seen for past history of intestinal parasitosis and surgical operation, hormone therapy, all industrial workers and workers in clothes & textile industry. However results may be influenced by more years of education or recall bias. 4) When a conditional logistic model was applied and controls with gallstone(s) were taken as reference, those with the habit of constipation showed a significantly high risk of 2.10 (95% CI: 1.01-4.38), and the consumers of red chili with a frequency > or = 1 time/day had elevated risks of 2.16 (1.27-3.66) vs those < 1 time/day and 4.66 (1.63-13.40) vs non-consumers, respectively. From the above results, the occurrence of gallbladder cancer in Chilean females may be related to constipation and chili pepper consumption, based on the presence of gallstone(s). Further investigations are needed to elucidate whether these are actual risk factors or whether only a false association was detected.
Case-Control Studies↗
Risk factors for gallbladder cancer. An international collaborative case-control study.
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Case-Control Studies↗
Lectin histochemistry during in vitro capacitation and acrosome reaction in boar spermatozoa: new lectins for evaluating acrosomal status of boar spermatozoa.
Six peroxidase (HRP)-conjugated lectins have been used to analyze the distribution of carbohydrates in ejaculated boar spermatozoa during in vitro capacitation and acrosome reaction in air-dried preparations. The membranes of boar spermatozoa were positive to WGA and Con-A in the acrosome, middle piece and principal piece. PNA labelled the acrosomal region. DBA, UEA-I and LTA bound weakly or not to the spermatozoa. The lectin labelling pattern did not change during the in vitro capacitation. A diminution in the proportion of spermatozoa with acrosome positive to lectins PNA, WGA and Con-A was observed after coincubation with homologous immature oocytes. A positive correlation existed between the percentages of lectins bound to spermatozoa and the triple stain technique. The results show that peroxidase-conjugated lectins may be useful in determining acrosomal integrity of boar spermatozoa during in vitro capacitation and acrosome reaction.
Acrosome↗