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M C de Castro

Publications and source records attributed to M C de Castro.

14 recordsLinked to original sources
PubMed2001

Agricultural colonization and malaria on the Amazon frontier.

The purpose of this paper is to characterize the interrelationships between macropolitical, social and economic policies, human migration, agricultural development, and malaria transmission on the Amazon frontier. We focus our analysis on a recent colonization project, POLONOROESTE, in the state of Rondonia. Employing data from field surveys in 1985-1987 and 1995, we use spatial statistical methodologies linked to a geographical information system (GIS) to describe the patterns of human settlement in the area, the ecological transformations induced by forest clearance practices, and the manner in which these factors determine gradations of malaria risk. Our findings show that land use patterns, linked to social organization of the community and the structure of the physical environment, played a key role in promoting malaria transmission. In addition, the location of each occupied area is itself an important determinant of the pattern of malaria risk. Based on lessons learned from our spatial and temporal characterization of malaria risk, we propose policies for malaria mitigation in the Brazilian Amazon.

Adult↗
PubMed2000

An artificial grasping evaluation system for the paralysed hand.

Neuromuscular electrical stimulation (NMES) has been used in upper limb rehabilitation towards restoring motor hand function. Quantitative evaluation of the artificially generated movement is necessary to achieve proper muscle activation. Custom-made gloves instrumented with force and position transducers were used to evaluate artificial quadriplegic grasping for a drinking activity. In spite of different sensor position, stimulation parameter dependence and lack of repeatability, grasp patterns achieved with the application of NMES follow the same patterns previously obtained with normal subjects, regarding force distribution among fingers and the shape of force curves. Larger forces were exerted by the thumb (average ranged from 2.8 to 4.5 N) following by index or long finger (average ranged from 1.8 to 3 N). The forces exerted ranged within the same interval as those previously measured and were sufficient to grasp an object of 10 N. Finger position achieved by interphalangeal joint status indicated the opening size of the hand throughout the range of movement. The instrumented gloves offer an alternative force and position feedback system for use in cylindrical grasp evaluation. The gloves can be used in a closed-loop control system, allowing on-line adjustment or in a clinical application to evaluate the results of a rehabilitation programme.

Biofeedback, Psychology↗
PubMed2000

Artificial sensorimotor integration in spinal cord injured subjects through neuromuscular and electrotactile stimulation.

Spinal cord injured (SCI) subjects lack sensorimotor functions. Neuromuscular electrical stimulation (NMES) systems have been used to artificially restore motor functions, but without proprioceptive feedback, SCI subjects can control NMES systems only when they can see their limbs. In a gait restoration system, the subject looks down to the ground to be aware of where his foot is while in a grasping activity, maximum grip strength is employed regardless of the force that is required to perform tasks. This report focuses on artificial sensorimotor integration. Multichannel stimulation was used to restore motor functions while encoded tactile sensation (moving fused phantom images) relating to artificially generated movements was provided by electrotactile stimulation during walking and grasping activities. The results showed that the sensorimotor integration attained yielded both the recognition of artificial grasp force patterns and a technique to be used by paraplegics allowing spatial awareness of their limb while walking.

Adult↗
PubMed1999

Effect of dialyser biocompatibility on recovery from acute renal failure after cadaver renal transplantation.

BACKGROUND: It has been reported that patients with acute renal failure (ARF) requiring haemodialysis show an improved recovery of renal function when the dialysis treatment is performed using a biocompatible membrane rather than a bioincompatible membrane. However, most recent published human trials have not been able to confirm these findings. METHOD: Over a 2-year period, we prospectively studied 53 patients with ARF after cadaver renal transplantation who required haemodialysis and randomized them into two treatment groups. One group underwent dialysis with a cuprophane membrane and the other group underwent haemodialysis with a more biocompatible membrane, polysulfone. All patients received an immunosuppressive regimen which included azathioprine, prednisone and cyclosporine. RESULTS: There was no difference by patient characteristics or immunosuppressive regimen before acute tubular necrosis (ATN) recovery. In both groups the number of haemodialysis sessions required prior to the recovery of renal function (6.57+/-2.79 vs 6.05+/-2.40), the number of oliguric days (16.25+/-5.14 vs 14.40+/-4.67) and the number of hospital days (33.38+/-12.85 vs 30.10+/-11.00), were not statistically different. There was also no difference in long-term allograft outcome. CONCLUSION: Our data demonstrate that the use of a more biocompatible membrane had no influence on the recovery from acute renal failure after renal transplantation.

Acute Kidney Injury↗
PubMed1998

Post-transplant neutrophilic interstitial nephritis--an important cause of graft dysfunction.

Post-transplant neutrophilic interstitial nephritis (NIN) is characterized by an interstitial infiltrate consisting of polymorphonuclear cells that leads frequently to acute graft dysfunction. In 220 graft biopsies performed because of renal dysfunction over 2 years in our unit, 11 (5%) diagnoses of NIN were made. Only two patients had chronic pyelonephritis as original disease. Four patients had urological problems before transplantation. After transplantation, five patients had urinary tract infection, one had urethral stenosis, two had vesicourethral reflux and one patient had a perinephritic abscess. Seven patients had fever (63%). Only in six patients did urine culture lead to microorganism isolation. After 6 months, only two patients had a serum creatinine level < 1.4 mg/dl, five patients had abnormal function, three had lost their grafts, and one patient had died with sepsis. We conclude that 5% of the biopsies performed in our center disclosed NIN, an entity that causes graft dysfunction and progresses frequently to chronic renal failure. In some cases, no infectious etiology could be detected.

Female↗
PubMedDate not supplied

Hair removal.

Explore the source record for details and available documents.

Cosmetics↗
PubMedDate not supplied

Seasonal variation of blood pressure in maintenance hemodialysis.

CONTEXT: Seasonal variation in arterial blood pressure has been reported in studies with hypertensive and normotensive subjects. However, the influence of seasonal change on blood pressure of hemodialysis patients has not been reported. OBJECTIVE: To investigate the seasonal variation of blood pressure in Brazil, a tropical country, in patients on hemodialysis. DESIGN: Prospective, cohort study. SETTING: Dialysis unit of a tertiary medical center (a teaching hospital of the University of São Paulo School of Medicine, São Paulo). PATIENTS: Sixteen patients with chronic renal failure undergoing hemodialysis. OUTCOMES: Blood pressure, body weight, and ambient temperature were evaluated during 6 hemodialysis sessions carried out on 13 days during the four seasons. RESULTS: The diastolic blood pressure was lower in summer than in fall and winter (95 +/- 8 vs 107 +/- 10 and 101 +/- 10 mmHg, respectively; p < 0.05). The same was observed with mean blood pressure (116 +/- 8 vs 130 +/- 11 and 124 +/- 9 mmHg, respectively; p < 0.01). On the other hand, the ambient temperature was higher in summer than in fall and winter (23.0 +/- 1.6 vs 19.5 +/- 3.0 and 15.8 +/- 1.9 degrees C, respectively; p < 0.01). CONCLUSIONS: We concluded that for patients with chronic renal failure the blood pressure has a seasonal variation with higher pressures in fall and winter than in summer. Thus, further studies are needed to elucidate the impact of this observation on the adjustment of antihypertensive treatment and on morbidity and mortality in maintenance dialysis patients.

Adult↗
PubMedDate not supplied

[Cyclosporin A: experience of the Renal Transplant Unit of the Clinical Hospital of the Medical College of the University of Sao Paulo].

The authors report their experience using cyclosporine-A (CsA) in renal transplant patients. When compared with azathioprine/prednisone, CsA contributed significantly to a better graft and patient survival, either if used associated with prednisone of with azathioprine plus prednisone. CsA was also used in substitution to azathioprine in patients with hepatopathy attributed to azathioprine toxicity. The initial results are promising. The association of CsA and azathioprine with corticosteroids withdrawal was used as an attempt to allow normal growth in children. This seems to be the best choice of treatment for children. Careful monitoring of CsA blood levels avoids, or at least, minimizes nephrotoxicity. To achieve therapeutic CsA levels, patients with liver damage need lower, while children need higher oral CsA doses. To summarise: when CsA in carefully used, it is an excellent immunosuppressive drug.

Azathioprine↗
PubMedDate not supplied

[Corrosion of burnished or polished amalgam samples, using loss of mass after immersion in 1% NaCl solution].

This research evaluates the corrosion as expressed by the mass loss of experimental samples of both (conventional amalgam alloys (New True, Dentalloy and Velvalloy) and copper-rich alloys (Dispersalloy, Rezzizt II, Novaloy and Novaloy Plus) after immersion in a 1% NaCl solution. The sequence of treatments was: a) carved and burnished and b) carved, burnished and polished under uniform and controlled conditions the samples were weighed and alternatively submitted to immersion and finally brushed and weighed again after period of 30, 60 and 90 days. The polished samples exhibited a mass loss significantly lower than the burnished ones. The mass loss was statistically significant for the three experimental periods of time and presented a continuous mode. Differences among the alloys were detected either as to composition or surface treatment adapted.

Copper↗
PubMedDate not supplied

[Comparison of clinical and histological diagnosis in kidney post-transplantation period].

PURPOSE: To assess the agreement between clinical and histopathological diagnosis in a renal transplantation center, 40 episodes of acute renal failure were studied. METHODS: Kidney biopsies were performed at the moment that a clinical diagnosis was made by the staff. RESULTS: Nineteen episodes of acute tubular necrosis (ATN), eighteen episodes of acute cellular rejection (ACR), 2 humoral rejections and 1 acute cyclosporin nephrotoxicity episodes were diagnosed. ATN episodes were confirmed by renal biopsy in 84.21%, ACR episodes in 83.33%, humoral rejections in 100%. Renal biopsy showed ATN in the occurrence of clinical cyclosporin nephrotoxicity. Total agreement was 82.5%. CONCLUSION: There is a good relationship between clinical and histopathological diagnosis in the post-transplantation period. Diagnostic mistakes occurred mainly when oliguria was present.

Biopsy, Needle↗