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Biomedical subjects

C J Rodrigues

Publications and source records attributed to C J Rodrigues.

At least 19 recordsLinked to original sources
PubMed2005

Colletotrichum gloeosporioides can overgrow Colletotrichum kahawae on green coffee berries first inoculated with C. kahawae.

Colletotrichum gloeosporioides is a weak pathogen of coffee that infects ripe berries at dark red stage causing necrotic lesions, but only penetrates up to the second superficial layers of the pericarp at the rose and pink stages. C. kahawae, the causal agent of coffee berry disease (CBD) and responsible for 70-80% of crop loss, infects berries at any stage of development. When green berries are first inoculated with C. kahawae and then at 2, 72 or 96 h later with C. gloeosporioides, the necrotic lesions were significantly larger than in the controls, and were much more evident when the berries were incubated at the optimum growth temperature of 28 degrees C for C. gloeosporioides. Isolations from the lesions induced by the first inoculations with C. kahawae followed by inoculation with C. gloeosporioides revealed that all or most of the time the recovered isolates of the latter. Thus, C. gloeosporioides can overwhelm C. kahawae under conditions of higher environmental temperature and humidity and may enhance the CBD infection process under field conditions.

Coffea↗
PubMed2001

The value of teaching sectional anatomy to improve CT scan interpretation.

A specific course on sectional anatomy was developed to help medical students improve their knowledge of cross-sectional imaging. The educational methodology consists of identifying anatomical structures displayed in plastinated sections from human cadavers and corresponding anatomical structures in computed tomography (CT) sections from healthy patients. The course has a self-study format. To assess and verify the impact of learning sectional anatomy on radiological knowledge, students were asked to identify ten anatomical structures in CT images. This test was applied to two groups of students: Group I had been taught sectional anatomy with CT images 2 years before the test; Group II had not received instruction in sectional anatomy prior to the test. Analysis of the results revealed a significant difference in test scores (median percentages of correctly identified structures) between Group I and Group II, with scores of 100% and 63.4%, respectively. These results provide evidence that the inclusion of sectional anatomy training in medical school curricula has a great impact on subsequent CT interpretation.

Anatomy↗
PubMed2000

Morphology and diameter of infrarenal aortic aneurysms: a prospective autopsy study.

PURPOSE: To determine the diameter and morphology of infrarenal aortic aneurysms in 78 fresh autopsy specimens. METHODS: To avoid underestimation of the arterial diameter postmortem and to re-establish aneurysm morphology, a device was designed and introduced into the vessel, inflated to 80 mm Hg, and the largest external diameter was measured. RESULTS: The ages of the individuals ranged from 40 to 97 yr (mean 70). Thirty-eight aneurysms were ruptured with diameters ranging from 5.3 to 17.0 cm (mean 7.97), and 40 aneurysms were nonruptured with variations in diameters from 2.8 to 6.1 cm, mean 4.02 cm (P<0.01). Fusiform aneurysms were more frequent, and when they ruptured their diameters were smaller than the diameters of the spherical aneurysms (P<0.05). Aneurysms ruptured more frequently in the posterior wall (67%) and in the inferior portion (61%). A mural thrombus was found at the site of rupture in 80% of the specimens. CONCLUSION: In our samples, rupture was found solely in those aneurysms with a diameter over 5.0 cm, ruptures occurred earlier in fusiform aneurysms, mural thrombus was not a protective factor, and finally, aneurysms ruptured mainly in the posterior and inferior portions.

Adult↗
PubMed2000

A comparative study of aging of the elastic fiber system of the diaphragm and the rectus abdominis muscles in rats.

In the present study the age-related changes of the striated muscle elastic fiber system were investigated in the diaphragm and rectus abdominis muscles of 1-, 4-, 8- and 18-month-old rats. The activation patterns of these muscles differ in that the diaphragm is regularly mobilized tens of times every minute during the entire life of the animal whereas the rectus abdominis, although mobilized in respiration, is much less and more irregularly activated. The elastic fibers were stained by the Verhoeff technique for mature elastic fibers. Weigert stain was used to stain mature and elaunin elastic fibers, and Weigert-oxone to stain mature, elaunin and oxytalan elastic fibers. The density of mature and elaunin elastic fibers showed a progressive increase with age, whereas the amount of oxytalan elastic fibers decreased in both diaphragm and rectus abdominis muscles and their muscular fasciae. These age-related quantitative and structural changes of the elastic fiber system may reduce the viscoelastic properties of the diaphragm and rectus abdominis muscles, which may compromise the transmission of tensile muscle strength to the tendons and may affect maximum total strength.

Aging↗
PubMed1999

The effects of early and delayed immunosuppression in experimental tracheal transplantation with omentopexy.

BACKGROUND/PURPOSE: Best results in experimental tracheal allotransplantation are obtained when metachronous revascularization by omentopexy and immunosuppression are used. Nevertheless, this method of revascularization implies in a 4-day period of ischemia to the graft. The aim of this study was to assess the influence of the 4-day period of ischemia on host sensitization as well as the effect of early or delayed immunosuppression on the outcome of the grafts. METHODS: Thirty rabbits were submitted to tracheal allotransplantation and divided according to position of the graft (orthotopic or heterotopic transplants) and the initiation of immunosuppression (early or delayed). The quality of the revascularization was evaluated by the identification of Indian ink, perfused through the abdominal aorta, inside the submucosal vessels. The outcome of the grafts was evaluated by histological analysis according to a semiquantitative scale of alterations. RESULTS: Grafts were better revascularized in heterotopic position. Grafts with late immunosuppression presented good outcome only when heterotopically positioned. No significant differences were observed in grafts placed heterotopically or orthotopically when immunosuppression was initiated early after the transplant. CONCLUSIONS: Transient ischemia produced by metachronous revascularization is not the single factor responsible for the histological alterations observed in tracheal allografts. These alterations probably also are produced by the activation of immune responses. This activation is more intense in more ischemic grafts, but can be suppressed by early administration of immunosuppression.

Animals↗
PubMed1999

Age-related changes in the elastic fiber network of the human splenic capsule.

The structural arrangement of elastic fibers in the splenic capsule from 16 human cadavers ranging in age from 1 month to 76 years was studied by histologic sections stained with selective methods for elastin. In infants the elastic fibers of the splenic capsule were homogeneously intermingled with collagen fibers, an arrangement that stabilizes the capsule during spleen growth and enlargement. With aging, collagen fibers predominate in the outer capsular surface over elastic fibers with the latter more evident in the deep lamina of the splenic capsule. In elderly individuals, the elastic fibers shorten, fragment, and thicken. The progressive decrease in the amount of elastic fibers in the splenic capsule with aging may restrict splenic distention and contribute to involution of the spleen as one grows older.

Adolescent↗
PubMed1998

The effects of prenatal intraamniotic surfactant or dexamethasone administration on lung development are comparable to changes induced by tracheal ligation in an animal model of congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Lung surfactant deficiency contributes to the pathophysiology of congenital diaphragmatic hernia (CDH) and the high neonatal mortality rate. Acceleration of lung surfactant system maturation by prenatal administration of hormones has been described in animal models of CDH. However, in utero tracheal ligation (TL) is the best method to accelerate lung growth and reverse the pulmonary hypoplasia associated with CDH. Although this method offers promise, its application in humans is limited. The aim of this study was to investigate a new noninvasive therapeutic strategy, that is, the prenatal intraamniotic administration of exogenous porcine surfactant or dexamethasone, and compare it with the effects of TL in an animal model of CDH. METHODS: Twenty-four pregnant New Zealand rabbits underwent surgery on gestational day 24 or 25 to create CDH in 26 fetuses. Five groups of animals were studied: (1) Control, nonoperated fetuses (n=14), (2) CDH (n=6), (3) CDH plus TL (n 6), (4) CDH plus intraamniotic administration of Curosurf (40 mg; n=6), and (5) CDH plus intraamniotic infusion of dexamethasone (0.4 mg; n=8). On gestational day 30, the fetuses were delivered by cesarean section. Functional studies (lung hysteresis curves and lung distensibility), weight and volume of lungs, histopathologic and histomorphometric analysis of lungs were performed. RESULTS: The authors demonstrated that the hysteresis curve of CDH animals was shifted downward in comparison with controls. The analyses of curves standardized for lung weight indicated that intraamniotic administration of surfactant or dexamethasone improved lung compliance in comparison with controls and CDH fetuses, but TL had no effect on this parameter. Lung distensibility (maximum lung volume at 32 cm of water pressure per gram of lung) was reduced by CDH, but this parameter was increased by intraamniotic administration of drugs and not by TL (P< .05). CDH decreased the weight and volume of lungs (P< .05), and these changes were reversed only by TL, which prevented the herniation of the liver from the abdomen to the thorax. Histologically, CDH lungs treated with TL or intraamniotic administration of drugs demonstrated structural patterns similar to those of controls. Histomorphometric studies proved that CDH promoted significant thickening of septa walls (P< .05), and all the therapeutic methods could reverse this alteration to control values. The alveolar number per area in control lungs, CDH, and CDH plus TL lungs were similar, but in CDH plus surfactant and CDH plus dexamethasone lungs, the decreased number per area (P< .05) demonstrated that the alveolar airspace was increased. CONCLUSION: From these data the authors conclude that intraamniotic surfactant or dexamethasone administration is capable of preventing pulmonary hypoplasia in fetuses with CDH, and thus, this method may be a substitute for TL.

Analysis of Variance↗
PubMed1998

The effects of prenatal intraamniotic surfactant or dexamethasone administration on lung development are comparable to changes induced by tracheal ligation in an animal model of congenital diaphragmatic hernia: studies of lung glycogen content, elastic fiber density, and collagen content.

BACKGROUND/PURPOSE: A new noninvasive therapeutic strategy, which consisted of prenatal intraamniotic administration of porcine surfactant or dexamethasone, was previously used to prevent the functional and structural immaturity of lungs associated with congenital diaphragmatic hernia (CDH), and its effects on lung development were comparable with the changes induced by tracheal ligation (TL). The purpose of this study is to verify if this novel therapeutic modality has any effect in the elevated concentration of lung glycogen and altered contents of lung elastic fiber and collagen promoted by CDH. METHODS: A pilot study was performed to investigate in the rabbit model if the infused drugs in the amniotic cavity were aspirated by the CDH and non-CDH fetuses, and if there was correspondence between lung immaturity and high glycogen concentration in lung tissue. Experimental groups consisted of 50 pregnant rabbits that underwent surgery on gestational day 24 or 25 to create left-sided diaphragmatic hernias in 56 fetuses, which were divided in groups according to the procedures: CDH (n = 12), CDH plus TL (n = 16), CDH plus intraamniotic administration of Curosurf (40 mg, n = 12), and CDH plus intraamniotic administration of dexamethasone (n = 16). On gestational day 30, the fetuses were delivered by cesarean section, and 28 normal unoperated fetuses served as controls. The lungs were weighed and submitted to biochemical determination of glycogen, morphometric evaluation of elastic fibers, and colorimetric analysis of collagen. RESULTS: In all CDH and non-CDH fetuses of the pilot study, the amniotic content was massively aspirated into the lungs and trachea. There was an increase in lung glycogen content of fetuses at 24 days' gestation in comparison with 20-day gestational age fetuses, followed by a decrease in the near full-term fetuses. In the fetuses of the experimental groups, CDH decreased the lung weight to body weight ratios of lungs ipsilateral to the hernia. These changes were reversed by TL but not by intraamniotic administration of surfactant or dexamethasone. Lung glycogen concentrations in the lungs of CDH fetuses were significantly higher than those in the control group. These changes were reversed by intraamniotic administration of surfactant but not by dexamethasone administration or TL. In the lungs ipsilateral to the hernia, surfactant administration promoted a significant decrease in glycogen content to levels lower than control lungs. CDH promoted a decrease in the linear density of elastic fibers in both lungs, ipsilateral and contralateral to the hernia. This alteration was partially corrected by TL and surfactant administration, although dexamethasone administration had no effect. The concentrations of collagen in both lungs were increased significantly by CDH, and these alterations could not be reversed by TL. In the lungs ipsilateral to the hernia, intraamniotic administration of surfactant or dexamethasone promoted a significant decrease in the lung concentration of collagen but not to control levels. CONCLUSIONS: The positive effects of intraamniotic surfactant or dexamethasone administration on lung maturity of fetuses with CDH were observed. This therapy may be a substitute for TL.

Animals↗
PubMed1998

Circumscribed lesion of the medial forebrain bundle area causes structural impairment of lymphoid organs and severe depression of immune function in rats.

Interactions between the immune system and the brain are a key element in the pathophysiology of diseases such as multiple sclerosis, neuroAIDS, and Alzheimer's, which affect large numbers of individuals and are associated with a high social cost. However, the neuroanatomical basis of brain-immune interactions has not been elucidated. We report that in Wistar rats of either sex bilateral electrolytic lesion of the medial forebrain bundle reduces body weight by 28% 7 days after lesioning, and causes widespread infections, aphagia, adypsia, structural damage to the lymphoid organs and heavy depression of T lymphocytes cytotoxicity. The following alterations occur in the immune system after those lesions: the weight of the thymus, spleen and lymphonodes is reduced by 77.9%, 49.1% and 48.4%, respectively. The thymus is atrophied and contains fewer lymphoid cells in the cortex than in the medulla. In the spleen the white pulp is reduced and lymphoid cells from periarteriolar zones and at the chords are almost absent. In lymph nodes cortical small lymphocytes are depleted and primary and secondary nodules and germinal centers all but disappear. Cytotoxicity of lymphocytes is reduced by 86.2% in the thymus, 77.6% in the spleen and 70.2% in lymph nodes. The critical area of lesion is at the medialmost portion of the medial forebrain bundle, at the preoptic area and rostral part of the anterior hypothalamus. We suggest that this area contains neural circuits that are crucial for keeping the structure of lymphoid organs and the functional integrity of the immune system.

Animals↗
PubMed1996

Effects of aging on muscle fibers and collagen content of the diaphragm: a comparison with the rectus abdominis muscle.

Age-related changes of muscle fiber and collagen content of the diaphragm (DIA) and rectus abdominis (RA) muscles were examined in rats aged 1, 4, 8 and 18 months. The cross-sectional areas of all muscle fiber types (I, IIa, IIb) and the amount of collagen in both DIA and RA increased up to the age of 8 months after which a decrease in growth following a parabolic curve was found. The older DIA showed an increase in the percentage of type I fibers while in RA there was a high percentage of type IIb fibers. The aged DIA became more resistant to fatigue but at the expense of slow contraction while older RA is faster and stronger. Aged DIA and RA muscles showed a low amount of collagen with great concentration of cross-linkings leading to a tissue with low viscoelastic properties and reduced compliance.

Aging↗
PubMed1995

Sonographic assessment of normal spleen volume.

Thirty-two morphologically normal spleens from adult corpses were excised and immersed into a graduated water tank and the water volume displaced was considered as the actual spleen volume. After that, the splenic maximal height, width, and breadth were determined by a pachimeter. All the reference points were marked with a metal clip. Utilizing the metal clip references ultrasound maximal height, width, and breadth were determined. It was assumed that the ultrasound spleen volume was the result of the multiplication of the three ultrasonographic measurements previously obtained. There was no significant difference between pachimeter and ultrasound determinations. The mean actual spleen volume was 147.5 cm3 (SD = 81.46). The mean ultrasound spleen volume was 283.8 cm3 (SD = 168.27). A roughly linear correlation between actual spleen volume (y) and ultrasound spleen volume (x) was found, y = 14.23 + 0.469 x (R2 = 0.94, P < 0.01).

Adult↗
PubMed1993

[Myopathies associated with tubular aggregates].

The authors report the case of a 58-year-old male patient with clinical and electromyographic features of myasthenia. Muscle biopsy with histochemistry and electronic microscopy made it possible to diagnose a myopathy associated with tubular aggregates. Attention is called to the fact that the anatomical pathologic alterations which were found may be present in a heterogenous group of patients showing a great variety of symptoms. Thus, there is no reason to consider the existence of a myopathy associated with tubular aggregates, since the anatomical and pathologic findings are inespecific and do not characterize any specific disease.

Biopsy↗
PubMed1993

[Morphologic study of the inferior cavo-atrial transition in man. Morphofunctional considerations].

PURPOSE: Analysis the fibrous elements of the transition between the inferior vena cava and right atrium. METHODS: Twenty adult (20-40 ys) were used. Properly preserved samples were analysed macro and microscopically. Fragments were excised from the inferior cavo-atrial transition and analysed under stereomicroscopic. RESULTS: The inferior vena cava valve was disposed at the wall of the vein. Insertions of striated muscular cardiac fibers bundles are seen at the anterior wall of inferior vena cava. These muscular bundles are directed towards the intima of the vein. There were at the venous posterior wall insertions of the cardiac muscular bundles, originated from the crista terminalis and from the interatrial septum, these bundles show an orientation predominantly oblique, with tendency to become circular. At the transition level, the bundles of smooth muscular fibers of the inferior vena cava, presented an oblique disposition, becoming predominantly circular. CONCLUSION: As the disposition of muscular cardiac fibers presents a predominantly circular direction and, the bundles of smooth muscular fibers of the inferior vena cava present the same direction, we could postulate that, when the atrial systole occurs, these muscular bundles would obliterate the cavo-atrial transition, preventing, this way, the venous reflux.

Adult↗
PubMed1991

Morphometric evaluation of acinar cell number and volume in rat pancreas treated with dl-ethionine.

1. The morphological changes of the pancreas induced by administration of dl-ethionine were determined for treated rats and for a group of pair-fed untreated controls in order to separate the direct effect of dl-ethionine from the effect of accompanying reduction of food intake. 2. Adult male Wistar rats were studied in 3 groups of 10 animals each: 1) fed ad libitum and treated daily with dl-ethionine (35 mg/100 g body weight, ip) for 10 days; 2) treated daily with vehicle (saline) as group 1 and pair-fed to group 1; 3) treated daily with vehicle (saline) and fed ad libitum. Two rats from each group were killed on days 2, 4, 6, 8 and 10 to characterize the pancreas in terms of morphological properties using morphometric analysis. 3. Exposure to dl-ethionine induced a progressive and significant decrease in both pancreas weight and acinar cell number and volume. Pair feeding induced less pronounced decreases in pancreas weight and acinar cell volume. Pancreas weight was 125 mg/100 g body weight for dl-ethionine-treated vs 205 mg/100 g body weight for pair-fed controls and 320 mg/100 g body weight for ad libitum-fed controls after 10 days. Acinar cell number (x +/- sigma/square root of n): 175 x 10(6) +/- 28.4 per micron3 for dl-ethionine-treated vs 221 x 10(6) +/- 17.3 per micron3 for pair-fed controls and 271 x 10(6) +/- 23.9 per micron3 for ad libitum-fed controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1991

Structural and cytochemical study of the rat exocrine pancreas treated with dl-ethionine. I. Multilayered bodies and lesioned areas.

The fine structural changes and the reactivity for acid phosphatase (AcPase) and thiamine pyrophosphatase (TPPase) were studied in thin sections from rat pancreatic acinar cells exposed to dl-ethionine for 2-10 days. The cells from ad libitum and pair-fed controls exhibit occasionally 0.2-0.6 microns circular profiles showing reaction for AcPase and considered as presumptive lysosomes. At days 2 and 4 of dl-ethionine treatment the acinar cells exhibit presumptive lysosomes, autophagosomes and membrane-bounded cytoplasmic areas devoid of electron density and AcPase activity, containing scattered membranous elements. These regions were named lesioned areas. On 6th, 8th and 10th days a membrane bound anomalous cytoplasmic structure that represents a dense pile of layered membrane-like material (multilayered bodies, MB) was seen. The MBs consistently show AcPase activity and in rare instances TPPase activity. Freeze fracture studies reveal that the limiting membrane of the MBs has intramembranous particles whereas the multilayered membranous contents are devoid of such particles. The structure and disposition of the lamellae of the MBs seen in the replicas are similar to those of artificially prepared phospholipidic membranes.

Acid Phosphatase↗
PubMed1991

Predicting the immediate outcome of patients with cerebrovascular accident: a prognostic score.

A prognostic score was derived from a prospective study of 120 consecutive patients with cerebrovascular accident. Multivariate analysis was used to compare the presenting clinical features of 106 (88%) of these patients with their immediate outcome (survival or death). Similar analysis was also used to compare features on CT scan with immediate outcome in 45 patients. The immediate prognostic features included old age, history of previous stroke, mental obtundation at the onset, persistent altered consciousness greater than or equal to first 48 hours, altered consciousness appearing in the first 24-72 hours, complete hemiplegia, seizures, aspiration pneumonitis, and multiple/massive lesions and gross mass effect on CT scan. The prognostic score derived from discriminant function using CT scan variables was less accurate than that formulated from only clinical variables. In the latter (using clinical variables) a prognostic score of 46 or less suggested a 50% chance of recovery, scores of 47 or more a 50% chance of death, while scores of 12 or less and 63 or more suggested a 99% likelihood of survival and death respectively.

Brain Damage, Chronic↗