Biomedical subjects
Publications and source records attributed to A Sierra.
We describe a 68-year-old patient with Parkinson's disease who developed retroperitoneal fibrosis during pergolide treatment. Because pergolide is an ergot derivative, it could be related to the development of this complication.
The in vitro susceptibility to ofloxacin, norfloxacin and ciprofloxacin or 54 Mycobacterium fortuitum isolates originating from clinical samples (7) of patients attending the Hospital Universitario de Canarias and Hospital del Tórax, and from environmental (47) sources, were determined. For this, two methods were used: dilution in agar with Middlebrook 7H10 Agar as a base medium culture, and broth microdilution, with Mueller-Hinton Broth without supplement. The different isolates under study revealed a uniform susceptibility by both methods against ciprofloxacin. 100% inhibition was obtained from a Minimum Inhibitory Concentration (MIC) of 0.25 microgram/ml, and 2 micrograms/ml of ciprofloxacin, for broth microdilution and dilution in agar, respectively. For ofloxacin and norfloxacin, all the isolates were inhibited at an MIC of 0.5 microgram/ml, by the broth microdilution method, which contrasted sharply with an MIC of 32 micrograms/ml, in the case of dilution in agar. In this study, we have observed the existence of differences in the in vitro susceptibility of the isolates of M. fortuitum against the three fluoroquinolones assayed, mainly for ofloxacin and norfloxacin, by both methods. We, therefore, consider it necessary to establish a standardized, reproducible assay method, for the study of sensitivity to atypical mycobacteria.
Infectious diseases of the ear are important in adults due to their incidence and relapses. We carried out a study of aerobic microorganisms on 251 otic exudates from patients diagnosed as having chronic suppurative otitis media without cholesteatoma (119), chronic suppurative otitis media with cholesteatoma (85) and chronic external otitis (47). The microorganisms predominantly isolated were, Pseudomonas aeruginosa, Staphylococcus aureus and other Enterobacteriaceae. 86% of isolates were monomicrobial and 14% of isolates were polymicrobial. In these latter the predominantly isolated microorganisms were also P. aeruginosa, S. aureus, Corynebacterium spp. and Proteus mirabilis. P. aeruginosa was the most commonly isolated and showed the highest percentages of resistance against antimicrobial agents tested. P. aeruginosa was most susceptible to ciprofloxacin and imipenem, but much less susceptible to cefotaxime, moxalactam and trimethoprim-sulfamethoxazole. S. aureus was highly sensitive to amoxicillin/clavulanate, trimethoprim-sulfamethoxazole, rifampin and teichoplanin. 100% of the isolates were resistant to penicillin G and ampicillin.
The authors investigated the in vitro susceptibility to antimicrobial agents of 220 Mycobacterium fortuitum isolates originating from clinical samples (14) of patients attending the Hospital Universitario de Canarias and Hospital del Tórax, and from environmental sources (206): 3 from sea water, 10 from the water supply and 193 from sewage. The Minimum Inhibitory Concentration (MIC) was calculated using the broth microdilution method with Mueller-Hinton Broth without supplement. Amikacin was the most efficacious antimicrobial agent against all the isolates of M. fortuitum with an MIC which was considerably lower than its critical concentration. The good results achieved with amikacin in vitro are confirmed by those obtained in vivo, with patients infected with M. fortuitum. No significant difference was found in the efficacy of amikacin and ofloxacin against all the isolates assayed.
Two atypical serological markers of hepatitis B virus (HBV) infection were detected in 19 patients during a 18-month period study. Pattern 1 (10 patients) was consistent with HBV-2 infection. Reactivity of HbsAG was confirmed by neutralization tests; the absence of other markers was also verified, included anti-HBcIgM. Three of the patients were classified in high risk groups and seven in the low risk groups for hepatitis B; in none of them was co-infection with hepatitis A virus (HAV) detected. Pattern 2 (9 patients) was characterized by the detection of HBsAg and HBeAg and the absence of other hepatitis B markers. Six of these patients were HIV-positive patients and had increased and persistent levels (for longer than 12 weeks) of these markers. In the three remaining patients (with no underlying immunological disorders) there was a loss of these markers within a variable time (2 days to 16 weeks). Nevertheless, DNA-VHB was detected in one of these serum samples once all markers of virus B had disappeared.
The in vitro susceptibility of 32 Mycobacterium chelonae strains to 10 antimicrobial agents was determined. The sources of the different strains were: clinical samples from patients treated at the Hospital Universitario de Canarias and Hospital del Tórax (General and Chest facilities) and from environmental sources (water supply, sewage, swimming pools and the sea). The susceptibility tests were performed by a broth microdilution method (Mueller-Hinton Broth). The results showed amikacin as the most effective antimicrobial agent against M. chelonae isolates, then ofloxacin and cefoxitin. However no statistical difference was detected among them. The least effective was imipenem, followed by ciprofloxacin and norfloxacin.
The consumption of lacteal desserts in the province of Santa Cruz de Tenerife is notably high. However, there are no legal standards in Spain regarding microbiological quality. For this reason, we have decided that it would be of interest to carry out a health-sanitary study of these products, with the aim of discovering their microbial content. 330 samples of lacteal desserts on sale in the province of Santa Cruz de Tenerife have undergone analysis. They have been divided into three groups: cream caramel (egg and vanilla) (80), mousse (60) and the third group, known as "other desserts", which includes custard and the rest of lacteal desserts not included in the previous groupings (190). Neither E. coli, Salmonella spp., Shigella spp., nor Staphylococcus aureus have been detected in any of the samples analysed. In spite of the fact that the results obtained do not reflect high microbiological contamination, we consider it necessary to lay down legal standards, with reference values, for these lacteal products, which will guarantee good microbiological quality.
The in vitro activity of fluconazole, itraconazole and ketoconazole against 625 Candida yeast strains from patients treated at the University Hospital of the Canaries, by means of a micromethod of dilution in broth enriched with Yeast Nitrogen Base (YNB), and buffered to pH7, has been assessed. Species distribution was as follows: Candida albicans (388), Candida tropicalis (84), Candida glabrata (84), Candida parapsilosis (69). Our results show 10.0% and 8.8% of C. albicans resistant to itraconazole and fluconazole, respectively, and 1.8% resistant to ketoconazole; 39.5% of C. tropicalis were resistant to itraconazole, 34.5% to fluconazole and 2.4% to ketaconazole. 19.1% of C. glabrata were resistant to fluconazole and 13.1% to itraconazole; 4.4% of C. parapsilosis were resistant to fluconazole and 1.5% to itraconazole. In general C. tropicalis was the most resistant strain and C. parapsilosis the most sensitive. The greatest percentages of resistance in vitro were seen with the two triazols.
Wistar rats, eight days old, were subjected to permanent bilateral forebrain ischemia, followed by hypoxia for 15 minutes. A cerebral infarct, mainly involving the cerebral neocortex, hippocampus, amygdala, striatum and subcortical white matter was produced. Neurons and glia showing punctate chromatin condensation and karyorrhectic cells were observed 12 hours after hypoxia-ischemia. Their number increased during the first two days and recruitment of cells with degenerating nuclei occurred until day five. In situ labeling of nuclear DNA fragmentation stained many normal-appearing nuclei, as well as punctate chromatin condensations and nuclear fragments in karyorrhectic cells. Delayed neuronal death in the CA1 area of the hippocampus was observed after 20 minutes of transient forebrain ischemia in the adult gerbil. In situ labeling of nuclear DNA fragmentation demonstrated stained punctate chromatin condensation in a few degenerating cells at 48 hours post-ischemia. Substantial labeling of CA1 neurons occurred in the fourth day. Agarose gel electrophoresis of extracted brain DNA from ischemic infant rats and adult gerbils showed a ladder-type pattern which is typical of nuclear DNA fragmentation into oligonucleosomal fragments (internucleosomal cleavage). These findings suggest that endonuclease(s) activation may play a role in cell death induced by different forms of hypoxia-ischemia.
The extended lymphadenectomy has been proposed as routine procedure in the surgical treatment of gastric cancer, although some controversies have been published. We present a retrospective analysis on the impact of extended lymph node dissection after total gastrectomy, in terms of post-operative course and histopathologic findings, in a group of 30 patients with R2 lymphadenectomy and in 16 patients with R1 lymphadenectomy. There were no significant differences in duration of operation, amount of blood transfusion and length of hospital stay between the 2 groups. The only significant difference was found in the greater amount of drainage output after R2 lymphadenectomy as compared with R1. There were no mortalities in either group and morbidity rate was similar for both [43% in R1 and 40% in R2) mostly in the form of abdominal infections (18% in R1 and 16% in R2]). A significantly greater number of lymph nodes was identified after R2 gastrectomy. Fifty-three per cent of patients has positive lymph nodes, 12% of them being from the N2 echelon of nodes (including one case of early gastric cancer). Careful lymph node dissection in gastric cancer surgery allows a more precise staging of the tumor with no increase in postoperative morbidity.
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The effects of unilateral injections of 6-hydroxydopamine into the subthalamic nucleus on muscular rigidity and on motor behavior were examined. Muscular rigidity was judged by the appearance of electromyographical activity in the gastrocnemius-soleus muscle and motor behavior by the turning induced by DL-methamphetamine. The unilateral injection of 6-hydroxydopamine produced the appearance of electromyographical activity ipsilateral to the injected side and ipsilateral turning in response to systemic administration of DL-methamphetamine. These results suggest that the dopaminergic innervation exerts a tonic inhibitory action on the spontaneous activity of the subthalamic neurons. The loss of this action would cause muscular rigidity and motor asymmetry.
Theiler's murine encephalomyelitis virus (TMEV) is known to interact with cells of the central nervous system (CNS). Here we report that, interestingly, it is a potent inductor of interleukin-6 (IL-6) in the CNS of infected animals and in pure cultures of astrocytes. Maximal IL-6 gene transcription in glial cells, as detected by bioassay and ELISA, was observed at 6 and 24 h after infection. Astrocytes from both SJL/J and Balb/c (strains of mice susceptible and resistant, respectively, to TMEV-induced demyelination) produced similar amounts of IL-6, measured in tissue culture supernatants. These results indicate that although an immunomodulatory effect can be exercised by IL-6 synthesized by astrocytes, it does not play a crucial role in immune-mediated demyelination induced by TMEV.
Velocity-encoded Cine magnetic resonance imaging (MRI) was used to measure blood flow in the anterior tibial artery (AT), posterior tibial artery (PT), and popliteal artery of adult human subjects (mean age 29 yr) before and after 90 s of ankle dorsiflexion exercise. Before exercise, mean flow, peak systolic velocity, and end-diastolic velocity in AT were 8.1 +/- 1.6 (SE, n = 6) ml/min, 26.9 +/- 2.6 cm/s, and -0.6 +/- 0.4 cm/s, respectively. After exercise, mean flow and peak systolic velocity in AT increased by 19-fold and 3-fold, respectively, and end-diastolic velocity increased to 8.7 +/- 1.1 cm/s. Flow in popliteal artery above its bifurcation was similar to the sum of flows in AT and PT, both before and after exercise. Flow in AT declined exponentially after exercise with a mean half-time of 4 min. The results demonstrate the utility of MR phase-encoded flow-velocity measurements for physiological studies of peripheral vascular dynamics after exercise.
Cytokines have been postulated to exert an important modulatory and recruiting role in demyelination induced by Theiler's murine encephalomyelitis virus (TMEV) in SJL/J mice. Using a cytolytic bioassay and ELISA, we have detected and quantified a cytokine, tumour necrosis factor-alpha (TNF-alpha), in supernatants from astrocyte cultures infected in vitro with TMEV. TNF was detected only after TMEV-specific infection of astrocyte cultures (approximately 200-400 U/ml). In vitro TNF synthesis appeared in a dose- and time-dependent manner and was produced by both SJL/J (a strain susceptible to TMEV-induced demyelination) and BALB/c (a resistant strain) astrocytes. The precise nature of TNF activity was further assessed by fast protein liquid chromatography (FPLC) and antibody neutralization. These results indicate an active role for astrocytes as accessory immune cells in our experimental model for multiple sclerosis.
D1 dopamine receptors are present on terminals of striatal neurons to the pars reticulata of the substantia nigra in the rat. Here we have studied the effect of the activation of these receptors on the synthesis of gamma-aminobutyric acid (GABA) in slices of the pars reticulata of the substantia nigra isolated from 6-hydroxydopamine-lesioned rats. The synthesis was judged by the accumulation of GABA after inhibiting GABA transaminase with aminooxyacetic acid. Both dopamine and SCH 23390, a D1 agonist, stimulated the synthesis. The effect of both compounds was blocked by SCH 23390, a D1 antagonist, but not by sulpiride, a D2 antagonist. In the absence of receptor activation, the synthesis was very slow. The results suggest a trophic influence of dopamine upon the synthesis of GABA via D1 receptors.
The authors analyze the distribution of suicides according to the variables of sex, age and marital status in the Canary Islands, during the period 1977-1983, by means of a register that they themselves created in order to correct serious deficiencies in the official data. There were notable differences between men and women, and the tendencies observed in each case are also very different. The authors argue that this makes it necessary to separate the sexes in the epidemiological studies on suicide. The advantages and disadvantages of the direct and indirect methods in the standardization of the specific suicide rates are discussed. The specific rates related to marital status are standardized according to age and, likewise, the specific rates related to age are standardized according to marital status, for each sex. Once confounding factors are controlled, it becomes clear that there is a direct relationship between age and suicide. After adjusting for age, it is noted that the pattern of risk for different marital status categories varies by sex.
The production of interferon-tau (IFN-tau), interleukin-2 (IL-2) and prostaglandin-E2 (PGE2) in peripheral blood mononuclear cells (PBMC) stimulated with phytohemagglutinin (PHA) and the repercussion which these cytokines have on the growth and activity of the 2', 3' and cyclonucleotide-3'-phosphohydrolase (CNP) of cultures of rat oligodendrocytes were analyzed. The study was carried out in a group of patients (20 with active disease, 23 in remission) with defined multiple sclerosis (MS), a group of subjects with other central nervous system diseases (OCNSD) and a group of 20 healthy (HS). Increases in PGE2 were found in PBMC cultures of patients with MS (p < 0.0005, ANOVA test) and the production of PGE2 in patients with active MS correlated positively (R2 = 0.743, p = 0.02) with CNP activity in the oligodendroglial cultures. These results suggest that PGE2 may influence in the re-myelinization process.