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Biomedical subjects

F Teixeira

Publications and source records attributed to F Teixeira.

At least 55 records · Page 3Linked to original sources
PubMed1997

Therapeutic efficacy of interferon alfa-2b in infants with life-threatening giant hemangiomas.

BACKGROUND: Because of their size and the possibility of complications, giant hemangiomas represent a therapeutic challenge. Various forms of treatment have been used, with variable results, including surgery, embolization, lasers, pentoxifylline, and corticosteroids. Interferon alfa has been used successfully to treat life-threatening hemangiomas, possibly by means of its antiangiogenic activity. OBSERVATIONS: We treated 7 infants with organ-interfering and/or life-threatening giant hemangiomas with subcutaneous injections of 3 million U/m2 per day of interferon alfa-2b during the first month and subsequently every 48 to 72 hours, depending on the evolution in each case. The treatment lasted from 3 to 12 months. In 2 patients, interferon alfa-2b was administered while prednisone therapy was being tapered. In all 7 patients, there was considerable reduction of the volume of the hemangiomas and remission of their complications. All patients presented with fever, neutropenia, and an increase in serum aminotransferase levels. The patients who received interferon alfa-2b and prednisone seemed to improve at a faster rate. CONCLUSIONS: Interferon alfa-2b is a good option for the treatment of patients with steroid-resistant, organ-interfering and/or life-threatening giant hemangiomas. In our experience, the adverse effects were transient and minor and did not require the interruption of the treatment.

Antineoplastic Agents↗
PubMed1996

The triglyceride lowering effect of fish oils is affected by fish consumption.

We investigated the efficacy of fish oils in Portuguese patients with hypertriglyceridaemia and mixed hyperlipidaemia, and the influence of fish consumption on the triglyceride lowering capacity of fish oils. Forty patients participated in this double-blind study, consisting of a 4-week dietary or wash-out baseline period after which patients were randomly assigned to receive either 12 fish oil capsules (3.6 g/day of omega 3) or similar 12 soya oil capsules per day for a period of 2 months. There were no statistically significant changes of total, HDL or LDL-cholesterol, and triglycerides. Nevertheless, triglycerides increased 19.9% with soya oil and decreased 27.8% with fish oils. Also, there was an inverse relationship (rho = -0.352) between fish consumption and fish oils effect on triglycerides, and the triglyceride lowering with fish oils increased (from 27.8% to 44.4%), reaching borderline significance, if we excluded patients consuming one or more meals with fish per day. Glucose increased 11% (P = 0.0047) with fish oils. These findings suggest that the triglyceride lowering effect of fish oils is affected by fish consumption, and confirm that fish oils increase blood glucose levels in diabetics and non-diabetics.

Adolescent↗
PubMed1996

Effects of pentoxifylline or dexamethasone in combination with amphotericin B in experimental murine cerebral cryptococcosis: evidence of neuroexcitatory pathogenic mechanisms.

In a murine model of intracerebral infection by Cryptococcus neoformans the therapeutic effects of pentoxifylline or dexamethasone were studied alone and in combination with amphotericin B. Assessed parameters were mean survival time, brain histopathology index, amounts of glutamate and gamma-aminobutyric acid in the brain, and yeast CFU per brain. Survival increased significantly in mice treated with dexamethasone, amphotericin B, amphotericin B plus dexamethasone, and amphotericin B plus pentoxifylline; the latter had significantly longer survival than other treated groups. Indices of histopathological damage were similar in all treated groups. In infected untreated mice, the amounts of glutamate in the brain were decreased, presumably by depletion. In mice treated with amphotericin B plus dexamethasone, glutamate levels returned to the range of control mice. No differences in the amounts of gamma-aminobutyric acid were found between control and treatment groups. Brain fungal counts were significantly lower in mice treated with amphotericin B, amphotericin B plus dexamethasone, and amphotericin B plus pentoxifylline than in untreated animals. In this model, pentoxifylline in combination with amphotericin B improved survival, decreasing the fungal burden, and has potential as adjuvant therapy in cerebral cryptococcosis.

Amphotericin B↗
PubMed1995

Complexes of ciprofloxacin with metal ions contained in antacid drugs.

Simultaneous administration of antacids containing magnesium or aluminium and ciprofloxacin or other quinolones decreases the gastrointestinal absorption of those antibacterial agents. Current speculation about the mechanism of this interaction has focused on drug-cation chelation. The present study was designed to detect the protonation in solutions and the formation of the complex species at the pH levels typical of the gastrointestinal tract. It involves the study of ciprofloxacin in aqueous solutions containing Al3+ and (or) Mg2+ by combining the results of potentiometric and spectroscopic (1H nuclear magnetic resonance) techniques. Calculations were only performed for data in the range 4.5 < pH < 5.5 (pH levels typical of gastrointestinal tract) and the results of both methods are made self-consistent, assuming an equilibrium model including complex species MHL, MLOH (where H2L denotes ciprofloxacin and M is Al3+ or Mg2+); their formation constants are given.

Aluminum↗
PubMed1995

Contralateral trigeminal neuralgia: a new clinical manifestation of neurocysticercosis: case report.

In cysticercosis, the central nervous system is one of the most commonly affected sites; the clinical manifestations of this disease in the central nervous system can be very severe. The nature and intensity of the signs and symptoms depend on the location of the parasite; cysticeric situated in the cysternae may cause arachnoiditis and vasculitis, but the manifestations are rarely the result of their mass effect. We report the case of a 52-year-old woman with a racemose cysticercus in the left cerebellopontine angle, who presented with contralateral trigeminal neuralgia. The parasite was completely removed via a left suboccipital craniotomy. On the first postoperative day, the patient indicated that the pain had disappeared. The neuralgia was possibly caused by the distortion of the brain stem and the compression of the nerve against an arterial loop at the entry zone. This case demonstrates the advisability of obtaining imaging studies in all patients with trigeminal neuralgia before starting any treatment.

Brain Diseases↗
PubMed1995

Reversibility of the alterations induced by chronic alcoholism and malnutrition in rats after alcohol withdrawal and proper nutrition.

OBJECTIVE: The specific influence of malnutrition on the cellular damage induced by alcoholism has been poorly defined; therefore, the possible degree of improvement that could be obtained after the institution of proper nutrition and after alcohol withdrawal remains unclear. We studied both conditions in several combinations, either after chronic alcoholism, chronic malnutrition or both, and after reversal of each condition or of both. METHOD: Using experimental models of alcoholism and malnutrition, we studied the alterations induced by each condition and on the combination of both in five histological locations and in 10 hematological and biochemical parameters; afterwards, we studied the possible restorative effect on each parameter after 4 months of alcohol withdrawal or proper nutrition or both. RESULTS: Our results showed that chronic alcoholism induced a mean of 31% deviation from values obtained in controls, malnutrition induced 17%, and alcoholism and malnutrition combined induced 52%. Upon the removal of the offending condition, alcohol withdrawal brought 13% improvement and proper nutrition 5% improvement; in the animals with alcoholism and malnutrition, alcohol withdrawal and proper nutrition brought 26% improvement, alcohol withdrawal but continuation of malnutrition 10% improvement, and continuation of alcoholism but proper nutrition led to a further 8% worsening from the alterations already found during alcoholism and malnutrition. CONCLUSIONS: Multivariate statistical comparisons demonstrated that chronic malnutrition produced an important, independent and difficult to reverse effect on the damage induced by alcoholism in several histological and physiological parameters.

Alcoholism↗
PubMed1995

Clinico-pathological correlation in dementias.

The object of this study is to investigate whether or not there are clinical signs and symptoms in patients with dementia that, by themselves or jointly, can be associated with the pathological diagnosis of Alzheimer's disease. Twelve patients with dementia were studied, in whom the clinical diagnosis of Alzheimer's disease was made according to established criteria. A sample of leptomeninges, cortex and subcortical white matter was obtained from each patient and was processed for light and electron microscopy. In the cases in whom neuritic plaques and neurofibrilary tangles were present, pathological changes were quantified. The diagnosis of Alzheimer's disease was confirmed in 5 cases, whereas in 3 patients spongiform encephalopathy was present. In the remaining patients, the number of neuritic plaques was within normal limits for the age of the subjects. Comparison of the data in Alzheimer (n = 5) and non-Alzheimer (n = 7) groups showed an increased, statistically significant incidence of acalculia, abnormalities of judgment, impairment of abstraction and primitive reflexes in the former. Although good fitting models were obtained, none achieved perfect discrimination. The model that included alterations of judgment and acalculia gave the best fit.

Aged↗
PubMed1994

Cavernous hemangiomas of the dura mater at the convexity. Report of a case and therapeutical considerations.

A rare case of cavernous angioma of the dura mater at the convexity is presented. In comparison with the more common cavernous hemangiomas that arise from dural sinuses, the ones on the convexity have a much better prognosis. They do not seem to be associated with spontaneous hemorrhage, their removal is simpler and, transoperatory bleeding, if it occurs, is scanty. Computerized tomography detects the presence of cavernous angiomas of the convexity in only 70% of the cases, magnetic resonance imaging in 100%.

Aged↗
PubMed1994

Detrimental effects of malnutrition on the damage induced by alcoholism: a study of animal models that simulate chronic alcoholism and malnutrition of large human groups.

The specific influence of malnutrition on the pathophysiological changes induced by chronic alcoholism is controversial; most studies are inconclusive because they have been made in chronic alcoholics that develop malnutrition as a complication of alcoholism. However, in vast human groups, alcoholism evolves in individuals that belong to a chronically undernourished population. In an attempt to simulate real-life conditions of malnutrition-alcoholism in humans, we studied in rats: (1) the effects of chronic malnutrition with tortilla, a corn bread that constitutes the main diet of large human groups; (2) the effects of chronic alcoholism with commercial brandy; and (3) the effects of chronic alcoholism and malnutrition combined. The damage induced either by alcoholism or that induced by malnutrition alone were of similar degree, whereas the combination of malnutrition and alcoholism led to a worsening of some parameters studied: body weight, leucocyte count and, more remarkably, in the tissue damage of several areas of the central nervous system.

Alcoholism↗
PubMed1993

Experimental studies on the mechanisms of tiaprofenic acid photosensitization.

Red blood cell lysis and histidine degradation, photosensitized by tiaprofenic acid (TIA), were investigated. Photohaemolysis was markedly enhanced in oxygenated solutions, but was also intense in the presence of nitrogen. Photohaemolysis was inhibited by butylated hydroxyanisole and reduced glutathione, but was unaffected by sodium azide, superoxide dismutase and mannitol. The TIA-induced photo-oxidation of histidine was greatly enhanced in the presence of oxygen and almost completely inhibited in solutions bubbled with nitrogen. Sodium azide, butylated hydroxyanisole and reduced glutathione inhibited the photodegradation of histidine. Phototoxicity to histidine was unaffected by mannitol and superoxide dismutase. The overall results suggest that molecular mechanisms involving free radicals and singlet oxygen are responsible for TIA-photosensitized reactions. These two in vitro models (photohaemolysis and histidine degradation) represent different mechanisms of phototoxicity, but complement one another in the investigation of potential phototoxic substances.

Butylated Hydroxyanisole↗
PubMed1993

Protein kinase-C stimulatory activity in human amnion cytosol.

Cytosolic preparations from human amnions at term were tested for the presence of endogenous modulators of protein kinase-C (PKC) activity. Tissues were obtained from 14 patients undergoing cesarean section (CS) and 14 patients after spontaneous delivery (SL). PKC activity was significantly greater in cytosols from CS than SL amnion (1.65 +/- 0.04 vs 0.73 +/- 0.2 pmol/min, respectively; mean +/- SE; n = 14 CS; n = 14 SL; P < 0.05). When amnion cytosols were mixed with a control preparation of PKC (rat brain cytosol partially purified on diethylaminoethyl), PKC activity was significantly increased compared to the control value (control, 12.81 +/- 2.1; control + CS, 22.19 +/- 1.5; control + SL, 21.98 +/- 0.7 pmol/min). The stimulation of PKC was dose dependent. The PKC stimulatory factor in amnion cytosol was stable to heat treatment at 80-90 C for 2 min (control + heat-treated CS, 23.20 +/- 1.2; control + heat-treated SL, 24.49 +/- 1.0 pmol/min) and substituted for phosphatidylserine and diacylglycerol in the PKC assay (control, no lipids, 0.05 +/- 0.04 pmol/min; control + amnion cytosol, no lipids, 9.60 +/- 1.06 pmol/min). The PKC stimulatory factor was calcium dependent, was not extractable in organic solvents, and was greater then 100,000 mol wt. Thus, the human amnion contains a PKC stimulatory factor which may modify or mediate the cellular response to extracellular stimulators of the PKC pathway.

Amnion↗
PubMed1992

Photosensitivity to piroxicam: absence of cross-reaction with tenoxicam.

We studied 2 groups of patients. One group of 10 patients had a photosensitive eruption to piroxicam. Another group of 24 patients had positive patch test reactions to thimerosal and thiosalicylic acid and had never taken piroxicam or tenoxicam. Patients were patch tested with thimerosal 0.1% pet., thiosalicylic acid 0.1% pet., salicylic acid 2.0% pet., piroxicam 1 and 5% pet. and tenoxicam 1 and 5% pet. Photopatch tests were also performed with piroxicam and tenoxicam. All 10 patients with photosensitivity to piroxicam had positive patch tests to thimerosal and thiosalicylic acid and 9 of them had positive photopatch tests to piroxicam. 20 out of 24 patients with positive patch tests to thiosalicylic acid also had positive photopatch tests to piroxicam. All the patients tested with salicyclic acid were negative. Out of the 29 patients with positive photopatch tests to piroxicam, none reacted to tenoxicam. In countries with a high incidence of contact sensitivity to thimerosal/thiosalicylic acid, the use of piroxicam should be avoided and replaced by tenoxicam, a drug without reported photosensitivity.

Adult↗