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Biomedical subjects

S Castro

Publications and source records attributed to S Castro.

At least 19 recordsLinked to original sources
PubMed2006

Glutamate is involved in acid stress response in Bradyrhizobium sp. SEMIA 6144 (Arachis hypogaea L.) microsymbiont.

In the present study, the effect of acid stress on ammonium assimilation in Bradyrhizobium sp. SEMIA 6144 (Arachis hypogaea L.) microsymbiont was analyzed. The bacterial growth rate was decreased by 50%, and a significant increase in intracellular glutamate concentration was detected when the strain grew at acid pH (5.5). Assays of the enzymes involved in glutamate synthesis showed increased activities of glutamine synthetase (GS) and glutamate synthase (NADPH-GOGAT) under acid stress condition. This would support the contention that the GS/NADPH-GOGAT pathway contributes to the increase of glutamate synthesis as a compatible solute in response to acid stress.

Acids↗
PubMed2006

[Treatment with intravenous rt-PA in a general hospital context: A review of the Saint-Jean Hospital experience from Perpignan, France].

INTRODUCTION: Intravenous recombinant tissue plasminogen activator (rt-PA) has approval for use despite of its authorization for treatment of ischemic stroke within the 3-hour time window in 2003, is rarely used in community hospital (CH). It therefore remains questionable if the positive results of the key studies conducted in specialized centers may be extended to community hospitals less specialized in the management of stroke. METHODS: We report the results of an observational cohort study including 39 patients treated with intravenous rt-Pa (according to the NINDS rt-PA stroke trail treatment protocol) at St Jean Hospital (Perpignan, France) between March 1, 2002 and August 31, 2005. Results are compared to those of the treated arm of the NINDS study. RESULTS: 1.2p.cent of ischemic stroke were treated with intravenous rt-Pa. Results are similar to those of the NINDS study: The outcome was favorable (modified Rankin score (mRS) with 0 or 1) for 44p.cent of the patients (as compared to 39p.cent in the NINDS study (X2 = 0.34; p = 0.5)) and there was no significant difference in term of death or outcome as assessed by mRS at 3 months (X2 = 0.09; p = 0.75 and X2 = 0.77; p = 0.75, respectively). No symptomatic hemmorrhagic transformation related to the use of rt-Pa was observed. CONCLUSION: Our results indicate that rt-PA therapy for ischemic stroke may be as safe and effective in the setting of a community hospital as it is in specialized centers.

Adult↗
PubMed2005

Isolation in cell culture and detection by PCR-based technology of IPNV-like virus from leucocytes of carrier turbot, Scophthalmus maximus (L.).

A non-destructive procedure was utilized to determine the infectious pancreatic necrosis virus (IPNV) status of an apparently healthy turbot broodstock. Blood samples were used to detect IPNV by reverse transcriptase-polymerase chain reaction (RT-PCR), Southern blot hybridization and nested PCR. In addition, viral isolation from turbot leucocytes was performed. Around 22% of the fish were IPNV positive by RT-PCR, and this increased to close to 60% when nested PCR was performed. The present report supports the use of blood samples for the detection of IPNV-like viruses in brood fish. In addition, we demonstrate that it is possible to isolate the virus from the blood of carrier fish, as a non-lethal detection method, although it is much less sensitive than RT-PCR and nested PCR as a IPNV-like strain was isolated from only five of the 15 blood sample pools assayed. The viral isolate was identified as type Dry Mills (genogroup I) by means of restriction fragment length polymorphisms and DNA sequencing.

Animals↗
PubMed2001

Forearm bone density in long-term users of oral combined contraceptives and depot medroxyprogesterone acetate.

OBJECTIVE: To compare the bone mineral density of users of combined oral contraceptives (OC) or depot medroxyprogesterone acetate (depot-MPA) with women who have never used a hormonal contraceptive method. DESIGN: Cross-sectional study. SETTING: Academic tertiary-care hospital. PATIENT(S): A total of 189 women, aged 30 to 34 years old, were allocated to three groups: 63 who had used OC for at least 2 years; 63 who had used depot-MPA for at least 2 years; and 63 control women who had never used hormonal contraceptives. INTERVENTION(S): Each woman's bone mineral density (BMD) was evaluated at the distal and ultradistal section of the radius of the nondominant forearm by the use of single x-ray absorptiometry. MAIN OUTCOME MEASURE(S): We obtained BMD measurements for each participant. RESULT(S): Independent of the period of use and the section of the forearm studied, we found no difference in BMD for OC or depot-MPA users when compared to women who had never used hormonal contraceptive methods. In addition, BMD was similar between OC users and depot-MPA users. The multiple linear regression analysis showed that the variables associated with BMD were weight, number of pregnancies, and the woman's occupation. CONCLUSION(S): Women aged 30 to 34 years who have used OC or depot-MPA have similar BMD as control women. These findings suggest that the use of OC or depot-MPA does not affect the BMD of women in this age group.

Absorptiometry, Photon↗
PubMed2001

[Meningioma of the olfactory groove: review of a series of 27 cases].

OBJECTIVE: To describe our experience with olfactory groove meningiomas, analysing their clinical and radiological form of presentation and their surgical treatment. METHODS: The clinical records of 27 patients diagnosed of olfactory groove meningioma, extracted from the series of meningiomas operated on in our department since 1973, were retrospectively reviewed. Demographical data, the clinical presentation and duration of the symptoms before diagnosis were collected. Several radiological characteristics were also reviewed such as the tumour size, associated brain edema, type of contrast enhancement, presence of endostosis and invasion of the cranial base. The surgical resection grade, the histological type and the presence of recurrences in the follow-up were also analysed. RESULTS: The average age at presentation was 59 years. Average duration of symptoms prior to diagnosis was 39 months. The most frequent symptom at presentation was higher function impairment (52%), The average maximum tumoral diameter was 6.2 cm. 61% of the patients presented moderate or severe brain edema, which was quite frequently bilateral (74%). Radiological endostosis was present in 37% of the cases, but there were no signs of bone invasion in any case. The approach used was the basal frontal, uni or bilateral. In all cases the grade of resection was Simpson II. The majority of the cases presented a typical histology. Over 80% of the cases presented a good recovery at discharge. None of the patients presented with a tumoral recurrence after an average radiological follow-up of 74 months. CONCLUSIONS: The olfactory groove is an infrequent location for intracranial meningiomas, accounting for only 4.5% of all meningiomas in our experience. These tumours reach a big size due to the delay in diagnosis. Drilling of the cranial base does not seem necessary for preventing tumoral recurrence.

Adult↗
PubMed2001

Diagnosis disclosure in a Portuguese oncological centre.

The disclosure of a diagnosis of cancer to patients is a controversial matter. There have been major differences in practice concerning this issue through time and between cultures. A questionnaire was sent to the doctors of the Oporto Centre of the Portuguese Institute of Oncology in order to assess their attitudes. We received 45 responses (40%) from the 113 questionnaires sent. Of these, 32 (71%) said that they disclose the diagnosis as a general policy or at the patients' request, and 13 (29%) disclose it rarely or not at all. The most frequent reason indicated by these 13 physicians was that the disclosure might damage the patients psychologically. Forty-four (98%) doctors inform the family of the diagnosis. Thirty-nine (87%) think that patients are satisfied with the information provided. This study was carried out in one oncological centre only, so it is inappropriate to conclude that this is what happens throughout Portugal. As far as we know, this is the first study in Portugal addressing this area of practice. This subject is a very important topic of research both in Portugal and in other countries, as many published recommendations are not research based.

Attitude of Health Personnel↗
PubMed2001

Microcosm studies on the persistence of peanut inoculant in acid soil and its interaction with indigenous soil micro-organisms.

The effect of a native peanut (Arachis hypogaea) microsymbiont strain (streptomycin resistant mutant) introduced into acid soil on the indigenous micro-organism population as well as the survival of this isolate was studied. Although the isolate survived at a fairly low population level after the 3 month period of soil incubation, it maintained its antibiotic resistance. Slight changes in the total bacteria and fungi soil populations as a result of this inoculation were also detected.

Arachis↗
PubMed2000

Effects of salts on Debaryomyces hansenii and Saccharomyces cerevisiae under stress conditions.

The effect of Na+ and K+ on growth and thermal death of Debaryomyces hansenii and Saccharomyces cerevisiae were compared under stress conditions as those commonly found in food environments. At the supraoptimal temperature of 34 degrees C both cations at concentrations of 0.5 M stimulated growth of D. hansenii, while K+ had no effect and Na+ inhibited growth of S. cerevisiae. At 8 degrees C, close to the minimum temperature for growth in both species, both cations inhibited both yeasts, this effect being more pronounced with Na+ in S. cerevisiae. At extreme pH values (7.8 and 3.5) both cations at concentrations of 0.25 M stimulated D. hansenii while Na+ inhibited S. cerevisiae. K+ inhibited this yeast at pH 3.5. Thermal inactivation rates, measured at 38 degrees C in D. hansenii and at 48 degrees C in S. cerevisiae, decreased in the presence of both cations. This protective effect could be observed in a wider range of concentrations in D. hansenii. These results call the attention to the fact that not all yeasts have the same behaviour on what concerns synergy or antagonism of salt together with other stress factors and should be taken into consideration in the establishment of food preservation procedures.

Potassium↗
PubMed2000

The effect upon the human vaginal histology of the long-term use of the injectable contraceptive Depo-Provera.

The objective of the study was to evaluate the effect of long-term use of the injectable contraceptive depot medroxyprogesterone acetate (DMPA) on human vaginal histology. Twenty premenopausal women currently using DMPA as a contraceptive method for two and three years were compared with 20 regularly menstruating women, who never used Depo-Provera and/or other kind of hormonal contraceptive in the last 6 months prior to the study. Subjects and controls were matched by age (+/-1 year), body mass index (kg/m2) (+/-1.0), number of pregnancies (+/-1), age at first intercourse (+/-1 year), years of sexual activity (+/-1 year), and number of partners during their life (+/-1). Vaginal biopsies were performed in users at 90+/-7 days after the last injection and in nonusers at day 20-25 of the menstrual cycle. In addition, at the day of the biopsy a blood sample was collected to measure estradiol (in all women) and DMPA in users. The level of serum estradiol was significant lower in Depo-Provera users than in controls (p < 0.001). The thickness of the vaginal epithelium was not smaller among DMPA users than among controls, the mean count of Langerhans cells per mm of epithelium were almost identical in both groups, and no significant differences were found on the vaginal maturation indices. In conclusion, the use of Depo-Provera between two and three years did not affect vaginal thinning of the epithelium, Langerhans cell count or maturation index.

Adult↗
PubMed2000

Methods to evaluate nodulation competitiveness between Sinorhizobium meliloti strains using melanin production as a marker.

Three methods to evaluate the relative ability of different strains of Sinorhizobium meliloti to occupy nodules formed on alfalfa after co-inoculation were compare in this study. Results obtained using the three methods of evaluation together, provided insight into the relative nodulation competitiveness between two given sinorhizobial strains. A simple visual phenotypic marker, i.e., melanin production was used to distinguish individual strains in a given assay. As such, melanin producing strains were compared with melanin non-producing strains throughout this study. Method 1 required the use of an ELISA plate, took 35 min for the analysis of 40 nodules, and allowed strain identification by melanin production 2 days after nodule harvest. Method 2 required 3 h for the analysis of 40 nodules, used an ELISA plate, growth of bacteria on Petri dishes, and melanin production was analysed after 48 h of cell culture. Finally, method 3 involved the whole nodulated plant root, required less material than the above methods, and results were obtained after 24 h. Only method 2 was useful in determining if both a melanin producing strain and a melanin non-producing strain had occupied an individual nodule. Each of the three methods represented a rapid way of studying strain competition for field studies, using a natural trait as a marker.

Bacteriological Techniques↗
PubMed2000

Beneficial effects of modest systemic hypothermia on locomotor function and histopathological damage following contusion-induced spinal cord injury in rats.

OBJECT: Local spinal cord cooling (LSCC) is associated with beneficial effects when applied following ischemic or traumatic spinal cord injury (SCI). However, the clinical application of LSCC is associated with many technical difficulties such as the requirement of special cooling devices, emergency surgery, and complicated postoperative management. If hypothermia is to be considered for future application in the treatment of SCI, alternative approaches must be developed. The objectives of the present study were to evaluate 1) the relationship between systemic and epidural temperature after SCI; 2) the effects of modest systemic hypothermia on histopathological damage at 7 and 44 days post-SCI; and 3) the effects of modest systemic hypothermia on locomotor outcome at 44 days post-SCI. METHODS: A spinal cord contusion (12.5 mm at T-10) was produced in adult rats that had been randomly divided into two groups. Group 1 rats (seven in Experiment 1; 12 in Experiment 2) received hypothermic treatment (epidural temperature 32-33 degrees C) 30 minutes postinjury for 4 hours; Group 2 rats (nine in Experiment 1; eight in Experiment 2) received normothermic treatment (epidural temperature 37 degrees C) 30 minutes postinjury for 4 hours. Blood pressure, blood gas levels, and temperatures (epidural and rectal) were monitored throughout the 4-hour treatment period. Twice weekly assessment of locomotor function was performed over a 6-week survival period by using the Basso-Beattie-Bresnahan locomotor rating scale. Seven (Experiment 1) and 44 (Experiment 2) days after injury, animals were killed, perfused, and their spinal cords were serially sectioned. The area of tissue damage was quantitatively analyzed from 16 longitudinal sections selected from the central core of the spinal cord. CONCLUSIONS: The results showed that 1) modest changes in the epidural temperature of the spinal cord can be produced using systemic hypothermia; 2) modest systemic hypothermia (32-33 degrees C) significantly protects against locomotor deficits following traumatic SCI; and 3) modest systemic hypothermia (32-33 degrees C) reduces the area of tissue damage at both 7 and 44 days postinjury. Although additional research is needed to study the therapeutic window and long-term benefits of systemic hypothermia, these data support the possible use of modest systemic hypothermia in the treatment of acute SCI.

Analysis of Variance↗
PubMed1999

Forearm bone density in users of Depo-Provera as a contraceptive method.

OBJECTIVE: To determine the influence of depot medroxyprogesterone acetate (MPA) on bone mineral density when used as a contraceptive method. DESIGN: Cross-sectional study. SETTING: Academic tertiary-care hospital. PATIENT(S): Fifty premenopausal women who had used depot MPA as a contraceptive method for > or =1 year and 50 women who had never used hormonal contraceptive methods. INTERVENTION(S): Bone mineral density was evaluated at the midshaft and at the distal radius of the nondominant forearm using single x-ray absorptiometry. MAIN OUTCOME MEASURE(S): Bone mineral density. RESULT(S): Bone mineral density at the midshaft of the forearm was lower in depot MPA users than in women who had never used hormonal contraceptive methods, but the difference was not statistically significant. At the distal portion, bone mineral density was significantly lower in the study group. The duration of depot MPA use was not related to bone mineral density. CONCLUSION(S): Women > or =35 years of age presented with a lower bone mineral density only at the distal portion of the forearm after the use of depot MPA for > or =1 year. However, this decrease was not related to the duration of depot MPA use. It is not possible to conclude that women who use depot MPA are at risk of osteoporosis.

Adult↗
PubMed1998

The risk of inadvertent intrauterine device insertion in women carriers of endocervical Chlamydia trachomatis.

The most important complication attributed to the use of intrauterine device (IUD) is pelvic inflammatory disease (PID), often associated with Neisseria or Chlamydia infection. Consequently, the IUD should not be inserted in women at risk of infection or with symptoms of endocervicitis. To evaluate the effectiveness of such a policy, a systematic investigation of Chlamydia and Neisseria was carried out among 407 contraceptive acceptors. Twenty-seven cases were positive for Chlamydia and none were positive for Neisseria. There were no statistical differences in the proportion of women with and without Chlamydia who had vulvovaginal or cervical signs or symptoms, although twice as many women had pain at pelvic exam in the Chlamydia-infected group. In 29 women in whom infection was clinically suspected, two were found to be infected with Chlamydia. IUD were not inserted in women suspected of having infection, but 19 of 327 IUD acceptors were subsequently found to have a positive Chlamydia test result. Two women returned with symptoms of PID and 17 were asymptomatic, but all were treated. PID was not suspected in any other subject. These results reinforce the need for careful selection of IUD acceptors and for thorough counseling for symptoms of PID and the need for immediate consultation.

Adult↗
PubMed1998

Biochemical alterations in Bradyrhizobium sp USDA 3187 induced by the fungicide Mancozeb.

We have previously shown that fungicide Mancozeb causes a 50% decrease in Bradyhizobium sp USDA 3187 growth rate and affects the bacteria-root symbiotic interaction. In order to elucidate the fungicide toxicity mechanism we determined the effects of Mancozeb on cell chemical composition, glutathione (GSH) content (molecule involved in the detoxification process), glutathione S-transferase (GST) activity and on polyamine, exopolysaccharides, capsular polysaccharides and lipopolysaccharides. Mancozeb produced biochemical alterations in membrane composition, polysaccharides and polyamines. In spite of the increment of GSH content and GST activity, they are not enough to prevent the growth diminution.

Bradyrhizobium↗
PubMed1998

Response of Azospirillum brasilense Cd to sodium chloride stress.

Growth of Azospirillum brasilense Cd in the presence of different NaCl concentrations showed that it tolerates up to 200 mM NaCl in the medium, without appreciable decline in growth rate. At 300 mM NaCl, a decrease of 66% in growth was observed at 24 h of culture. At 48 h of culture, bacteria in the presence of 300 mM NaCl reached the maximum optical density value that was attained at 12 h by control cultures. This investigation was designed to elucidate the effect of saline stress on Azospirillum brasilense Cd and the physiologic mechanism involved in its possible salinity tolerance. For this reason, studies of other osmolytes, as well as of putrescine metabolism and protein patterns were done with bacteria grown with this NaCl concentration in the medium, at 24 and at 48 hours. A. brasilense responded to saline stress elevating the intracellular concentration of glutamate at 24 h, and of K+ at 48 h. Glucan pattern, putrescine metabolism, and total and periplasmic protein patterns of the treated group showed several changes with respect to the control. In spite of the several cellular functions affected by saline stress, the results imply that A. brasilense Cd shows salinity tolerance in these experimental conditions.

Azospirillum brasilense↗
PubMed1998

[Ambulatory geriatric assessment of 2116 in poor elderly].

BACKGROUND: Geriatric assessment quantifies medical, functional, mental and social capabilities and alterations of elders and is the first step to initiate specific intervention programs. AIM: To report the initial geriatric assessment of a program aimed to help poor elders living in Metropolitan Santiago. SUBJECTS AND METHODS: Two thousand one hundred sixteen free living subjects aged 65 to 99 years old (711 males) were subjected to an assessment using a simple geriatric score validated abroad and used previously in Chile. The resulting score ranges from 0 (better) to 5 (worst). RESULTS: Eighty eight percent of elders did not have problems in the functional evaluation. Subjects over 75 years old needed occasional support for the daily activities with higher frequency than younger subjects (12 and 5.4% respectively, p < 0.001) and had a higher frequency of major functional limitations (7.8 and 3.2% respectively, p < 0.001). Mental assessment was considered normal in 89.4% of subjects. Those over 75 years old had a higher frequency of memory disturbances (11.4 and 6.5% respectively) and cognitive alterations (4.6 and 1.8% respectively). Indefinite social support could be received by 84% of subjects, but 7.4% did not have access to this resource. CONCLUSIONS: Geriatric assessment of poor elders gives useful information to identify those subjects that require community help.

Age Distribution↗
PubMed1998

[Application of RUG-T18 classification system to elderly patients admitted to a university hospital].

BACKGROUND: Among case mix classifications, the best for hospitalized elders is the Resource Utilization Groups (RUG) system, which allows a better location of patients, resource administration and the design of health care strategies for elderly people. AIM: To report the results of RUG-T18 classification of elderly patients admitted to an university hospital. PATIENTS AND METHODS: RUG-T18 classification was applied to 210 patients aged 75.2 +/- 7.2 years old, 108 male, admitted to the Clinical Hospital of the Catholic University of Chile. RESULTS: The clinical classification of assessed patients was rehabilitation in 50.9% of cases, special care in 10.5%, clinically complex in 37.1% and reduced physical functions in 0.5%. None had behavioral alterations. There were no differences between subjects older or younger than 75 years old. Daily life activities showed that help was required for sphincter control in 46% of patients, for feeding in 44% and for mobilization in 64% (28% of patients required help from two or more people). Geriatric assessment showed that, since 1993, the proportion of elders with greater functional derangement increased from 18 to 28%, and the proportion of those with mental disturbances from 4 to 12%, specially among those over 75 years old. CONCLUSIONS: Most elders admitted to the hospital are classified in the superior categories of the RUG-T18 system and have severe mental and functional limitations. These patients require a multidisciplinary approach with a great emphasis in rehabilitation.

Aged↗