PubMed Health⌕ Search

Biomedical subjects

J Borges

Publications and source records attributed to J Borges.

16 recordsLinked to original sources
PubMed2002

Activity profile in multiple sclerosis: an integrative approach. A preliminary report.

In order to define an activity profile in patients with multiple sclerosis (MS), T-cell subpopulations and proliferative responses to myelin basic protein (MBP) associated with anti-MBP antibodies, nitrotyrosine levels in serum and cerebrospinal fluid (CSF), and serum CD40L (sCD154) were simultaneously assessed in 29 consecutive and untreated MS patients. When compared to controls, patients in secondary progressive stable (SP/I), or in full remission (RR/I) stages, individuals with secondary progressive active disease (SPIA) or in acute relapse (RR/A) showed a significant decrease of CD4/CD45RA+ T cells associated with an increase of absolute numbers of CD4/45R0+ T cells (p < 0.001). In addition, in vitro-specific T-cell proliferative responses against MBP (SP/A, RR/A, SP/I: p < 0.001 versus controls) in association with augmented sCD154 serum levels (SP/A, RR/A, versus controls p < 0.001) and a significant increase of both CSF and serum levels of anti-MBP antibodies and nitrotyrosine levels (p < 0.001) were also found. Thus, the simultaneous evaluation of antibody and cell-mediated immunopathological parameters, along with the effector mediators of inflammation such as the nitric oxide products, offers a new integrative approach to characterize markers of clinical activity in MS patients, which may be used at the moment of the initial diagnosis and during an apparent recurrences of the disease to monitor therapeutic protocols and to determine whether immune-based nerve destruction mechanisms are still operating in patients with few clinical findings.

Adolescent↗
PubMed2001

A reversible abnormal form of myelin: an X-ray scattering study of human sural and rat sciatic nerves.

A sural nerve dissected from a recently dead patient displayed an unusual X-ray diffraction pattern, suggesting that in situ and at the time of the patient's death the myelin sheaths were in a swollen state. Diffraction patterns of the swollen type were also recorded from: (1) a sural nerve from the corpse of a neurologically healthy person after soaking the nerve with Ringer solution at pH 5.5; (2) sciatic nerves dissected from rat cadavers at increasing time after death. In all the cases the swollen patterns reversed to the native type upon superfusion with Ringer solution at pH 7.3. The postmortem effect is to decrease the pH of the fluids surrounding the nerves in the cadavers. Our experiments show that the early postmortem processes have the effect of acidifying PNS nerves and that as a consequence of acidification the myelin sheaths swell.

Animals↗
PubMed2001

Plasmid gene delivery to human keratinocytes through a fibrin-mediated transfection system.

We have developed a matrix-mediated transfection system to deliver plasmids to human keratinocytes. The matrix is a soluble, self-hardening fibrin matrix (Tissucol), Baxter) that has been used clinically. Recently it has been shown that full thickness burn wounds can be successfully treated with a keratinocyte fibrin glue suspension. Further, it has been demonstrated that hEGF transfected cells accelerate wound healing. In this study, we inoculated the matrix with the hEGF expression plasmid and resuspended the matrix with either cultured or noncultured human keratinocytes. We obtained successful transfection rates of these cells (up to a 100-fold increase compared to controls containing no EGF expression plasmid) in vitro. After transplantation to full thickness wounds on athymic mice we were able to show a 180-fold increase in EGF concentration compared to controls, which persisted over the entire 7-day monitored period, decreasing from 180 to 20 pg/mL at day seven. This unique approach indicates the possible utility to combine a matrix for cell transplantation with a transfection system to release therapeutic proteins in vitro and in vivo.

Animals↗
PubMed2000

Acute endotoxemia protracts leukocyte / endothelium interaction after local ischemia and reperfusion in striated muscle.

Postischemic reperfusion injury and endotoxemia have been shown to promote multiple organ failure in polytraumatized patients. Both pathomechanisms comprise endothelial injury, leukocyte activation, and enhanced leukocyte/endothelium interaction in the microcirculation. Using a dorsal skinfold chamber model for intravital microscopy in striated muscle of awake hamsters, we investigated whether acute endotoxemia enhances postischemic leukocyte/endothelium interaction. - In control animals (n = 8), reperfusion after 2 hours of pressure induced ischemia elicited the rolling and adhesion of fluorescently stained leukocytes to the endothelium of postcapillary venules with a maximum at 0.5 and 2 hours after reperfusion and a decline towards preischemic values after 24 hours. Postischemic leukocyte adhesion was enhanced and protracted in animals where acute endotoxemia was induced through intravenous injection of endotoxin (Salmonella abortus equi, 0.1 microg¿kg superset-1) either 10 minutes prior to ischemia (n = 8) or to reperfusion (n = 8). - These results suggest that acute endotoxemia has the potential to aggravate the leukocyte-triggered reperfusion damage to striated muscle and presumably to vital organs and thus favours the development of multiple organ failure after primarily successful reperfusion.

Animals↗
PubMed2000

Malnutrition and myelin structure: an X-ray scattering study of rat sciatic and optic nerves.

Taking advantage of the fast and accurate X-ray scattering techniques recently developed in our laboratory, we tackled the study of the structural alterations induced in myelin by malnutrition. Our work was performed on sciatic and optic nerves dissected from rats fed with either a normal or a low-protein caloric diet, as a function of age (from birth to 60 days). By way of electrophysiological controls we also measured (on the sciatic nerves) the height and velocity of the compound action potential. Malnutrition was found to decrease the amount of myelin and to impair the packing order of the membranes in the sheaths.

Aging↗
PubMed2000

Gallstone ileus.

Explore the source record for details and available documents.

Aged↗
PubMed2000

Clinical comparative study between cryotherapy and local dermabrasion for the treatment of solar lentigo on the back of the hands.

BACKGROUND: Solar lentigo is a common and unsightly dermatosis that has a variety of proposed treatments. OBJECTIVE: This study was done to assess the efficacy and the effectiveness of localized dermabrasion compared with cryotherapy with liquid nitrogen on solar lentigo on the back of the hands. METHODS: Ten female patients aged 64-96 years with solar lentigo on the back of the hands were treated with dermabrasion or cryotherapy and observed over a 6-month period. RESULTS: The postsurgery signs and symptoms were less intense and better tolerated with localized dermabrasion. More than 50% of the patients treated with cryotherapy still had hypochromia in the treated areas 6 months after treatment, compared with 11% of the patients treated with dermabrasion. The percentage of recurrence was the same with the both treatments (55.55%). CONCLUSION: Localized dermabrasion is an efficacious and effective technique comparable to cryotherapy for the treatment of solar lentigo on the back of the hands.

Adult↗
PubMed2000

Role of L-selectin in leukocyte sequestration in lung capillaries in a rabbit model of endotoxemia.

After a variety of pathophysiologic stimuli, neutrophils accumulate in lung capillaries and contribute to the pathogenesis of acute lung injury. Lung neutrophil sequestration has previously been attributed to mechanical retention of stiffened neutrophils, but L-selectin-mediated leukocyte/endothelial interaction may be an essential step. We investigated the effect of the anti-L-selectin antibody HuDreg 200 on leukocyte sequestration and microhemodynamics in alveolar capillaries in a model of acute endotoxemia. We used in vivo fluorescence microscopy to analyze kinetics of fluorescently labeled red and white blood cells in alveolar capillary networks of the rabbit lung. Investigations were performed over 2 h after an intravenous infusion of 0.2 ml/kg body weight (bw) NaCl, 2 mg/kg bw HuDreg 200, 20 microg/kg bw lipopolysaccharide (LPS) of Escherichia coli 0111:B4, or the combination of HuDreg 200 and LPS, respectively. Infusion of LPS induced leukocyte sequestration in alveolar capillaries, which was accompanied by a reduction of alveolar capillary perfusion and functional capillary density. These effects could be completely blocked by pretreatment of animals with HuDreg 200. We conclude that L-selectin-mediated leukocyte/endothelial interaction is a necessary prerequisite for leukocyte sequestration in alveolar capillaries in this model. Impaired alveolar capillary perfusion appeared to result directly from capillary leukocyte sequestration.

Acute Disease↗
PubMed1993

Phacolytic glaucoma and lens-induced uveitis.

The pathogenesis of lens-induced uveitis and phacolytic glaucoma is still not fully understood. The authors report a case of a 62-year-old white female, with bilateral lens dislocation into the vitreous, who presented clinical and pathological features of phacolytic glaucoma in the left eye. The ultrastructural study of aqueous and vitreous aspirates showed lenticular fragments and macrophages with lipofuscin granules and phagocytic vacuoles containing lens proteins. Immunocytochemistry revealed foamy macrophages immunoreactive for CD68 and HLA-DR. One year later the right eye disclosed a mild anterior granulomatous uveitis with corneal mutton-fat keratic precipitates that remained unchanged in the course of sixteen months follow-up without further treatment. These findings corroborate the possibility that, besides their mechanical and inflammatory roles in the impairment of the outflow system of the (exciting) left eye, phacolytic macrophages might also have been involved in the afferent phase of the mild chronic uveitis of the (fellow) right eye.

Aqueous Humor↗
PubMed1990

Effects of repeated photic exposures on the monkey macula.

The posterior pole of the eyes of rhesus monkeys was exposed to the light of an indirect ophthalmoscope. The tissue changes caused by repeated (three to five) photic injuries were compared with those produced by a single photic insult. The ophthalmoscopic and angiographic examinations showed a progressive involvement of the foveal area after multiple exposures to light. Histopathologic study showed that after one exposure the retinal pigment epithelium appeared focally atrophic. Plaques of proliferated retinal pigment epithelium could also be seen, and on the anterior surface of these plaques a layer of relatively cuboidal hypopigmented retinal pigment epithelial cells was present. With multiple exposures, focal areas of total absence of retinal pigment epithelium were seen in these eyes. The eyes that received only one exposure showed partially regenerated photoreceptor outer segments. After repeated photic exposures, the photoreceptor outer segments failed to regenerate even 6 to 8 months after the last exposure. In one eye exposed five times for 60 minutes, areas of total absence of photoreceptor cells could be seen, and the inner nuclear layer was directly apposed to Bruch's membrane. These experimental exposures to the light of an indirect ophthalmoscope were 60 to 120 minutes long and were not comparable to clinical exposures of the ophthalmoscope in patient examination. Our observation highlighted the cumulative effects of repeated light injury to the retinal pigment epithelial and photoreceptor cells and also showed the similarity between this animal model of photic maculopathy and the changes present in the eyes of human patients with atrophic agerlated macular degeneration.

Animals↗
PubMed1976

Study of a new analgesic compound in the treatment of tension headache.

The effect of a new analgesic compound (propoxyphene, acetaminophen, caffeine, hydroxyzine) was investigated in a single-blind study comparing it with plain acetaminophen administered to forty patients with tension headache. For the study, patients were assigned to one of two groups of twenty each. Starting dose for each group was one to two tablets followed by one tablet every four to six hours. The results show that 90% clinical success was obtained with the analgesic compound, while a 45% success was obtained with plain acetaminophen. This is a statistically significant difference. Side-effects observed with analgesic compound were primarily drowsiness and dizziness of mild intensity; acetaminophen caused gastro-intestinal alterations (nausea, vomiting) and dizziness of greater severity. Therapy was withdrawn in 20% of patients taking acetaminophen because of side-effects. The dosage of analgesic compound required to control each episode of tension headache was smaller than that of acetaminophen. These results can be explained by a possible potentiation of pharmacological activity of the compound's components. It can be concluded that the analgesic compound is a new and effective combination for the symptomatic treatment of tension headache.

Acetaminophen↗
PubMedDate not supplied

Magnetic resonance imaging in retinoblastoma and retinocytoma: a case report.

Magnetic resonance imaging (MRI) is playing a growing role in the evaluation of ocular and orbital tumors. We report the case of a 26-month-old child presenting an undifferentiated retinoblastoma with a differentiated retinocytoma component in his left eye. After the eye was enucleated, we could correlate the clinicopathologic findings with the MRI scans. Both the undifferentiated retinoblastoma and the differentiated retinocytoma components could be determined on magnetic resonance imaging. Because different levels of metabolic activity within a tumor mass may influence largely T1 and T2 parameters, accurate determination of these values may be useful in determining the differentiation of a retinoblastoma, enabling a better therapeutic approach and assessment of the response to treatment.

Child, Preschool↗
PubMedDate not supplied

Percutaneous transluminal ultrasonic angioplasty: preliminary clinical report of ultrasound plaque ablation in totally occluded peripheral arteries.

Peripheral arterial obstructive disease has been treated with ultrasound ablation. Thirty two patients (pts), mean age 67 +/- 10 years underwent angiosonoplasty, with a prototype ultrasonic system, due to severe claudication (31%), rest pain (44%), rest pain and ulceration (25%). Angiosonoplasty was successful in 26/32 (81%) stenoses, (1/2 iliac, 9/2 femorals, 11/12 popliteal, 5/6 tibial). Angiography before and after angiosonoplasty confirmed that the lesions were successfully opened, (81%, p less than 0.05). A mean of 3 +/- 2 passes were required to adequately remove sufficient plaque. Balloon angioplasty was used in combination with angiosonoplasty in 11/32 (34%) occluded vessels. Complications included groin hematoma in 4 pts (12%) and vascular spasm in two patients (6%). Within 24 hours, 27/32 (94%) pts were discharged clinically improved. Reocclusion occurred in 4 pts (12%) immediately after the procedure. Ankle brachial indices significantly increased from 0.52 +/- 0.10 before to 0.70 +/- 0.12 after (p less than 0.05). In conclusion, the use of ultrasound energy to ablate atherosclerotic plaque would appear safe, and has shown no restenosis and a low incidence of complications over a six month period.

Aged↗