Alpha-L-fucosidase enzyme in the prediction of colorectal cancer patients at high risk of tumor recurrence

The aim of this study was to examine the prognostic value of the alpha-L-fucosidase enzyme to determine whether it can help in the early recognition of colorectal cancer cases at high risk of tumor recurrence. One hundred and twenty-three colorectal carcinoma patients treated by curative surgery were studied. The alpha-L-fucosidase activity was assayed in the tumor and in normal mucosa from each patient using a fluorometric method. Seven other clinical and pathologic features were also studied. To evaluate the impact of each variable over the disease-free interval, a postoperative 30-month follow-up of patients was performed, and a statistical survival analysis was carried out. The recurrence appearance was higher when the relative decrease of alpha-L-fucosidase activity was more than 52% (log-rank test, P = .0261). The results of this work indicate that alpha-L-fucosidase activity appears to be a good independent prognostic factor of tumoral recurrence in colorectal carcinoma.     

Effect of DL-propranolol on nitric oxide production in perfused rat hindquarters.

The effect of DL-propranolol on NO release in perfused rat hindquarters was studied by using oxyhemoglobin as a capture system to allow the quantitative assay of NO production. In some experiments the stable prostacyclin metabolite 6-keto-PGF1 alpha (6-keto) was simultaneously assayed. We observed that: (1) DL-propranolol induced an increase in NO and 6-keto release. The dextro isomer was inactive; (2) DL-propranolol-induced NO release was only slightly reduced by acetylsalicylic acid in a concentration that inhibits prostacyclin synthesis, and was abolished by the chemical removal of the endothelium with 3-3 cholamidopropyl dimethylammonium 1-propane sulphonate (CHAPS) applied before or during stimulation; (3) NG-nitro-L-arginine blocked DL-propranolol-induced NO production, an effect that was antagonized by L-arginine but not by its dextro isomer.     

Quantitative Analysis of Microglial Reaction to a Cortical Excitotoxic Lesion in the Early Postnatal Brain

This study was designed to quantify the microglial response following an injection ofN-methyl- -aspartate (NMDA) into the sensorimotor cortex of 6-day-old rats. After survival times ranging from 10 h to 28 days, cryostat sections were processed for the demonstration of microglial cells by means of tomato lectin histochemistry. The injection of NMDA caused an extensive primary lesion involving the neocortex, the rostral hippocampus, and rostral thalamus. In addition, secondary retrograde/anterograde degeneration was also observed in the ventrobasal (VB) complex of the thalamus. Microglial reactivity was already present at 10 h postlesion and restricted to areas of neuronal degeneration. Quantitative analysis was performed on digitized images using NIH Image software and a Macintosh computer. The method is based on densitometric ratios, referred to as the “reactivity grade,” between the ipsilateral lesion side and the contralateral control side. Measurements were made to determine a possible increase in the number of microglial cells as well as an increase in lectin binding. The analysis showed that microglial reactivity in areas of primary degeneration peaked at 3 days postlesion, when it was significantly (P < 0.01) higher in comparison to saline-injected litter mates. Microglial response in the cerebral neocortex, showing the highest reactivity grade, as well as in other areas of primary degeneration, returned to control levels by Day 7. Microglial response in the VB complex also peaked at Day 3 (P < 0.05) but maintained this level of reactivity until 7 days postlesion (P < 0.01).     

Sampling limitations in studies of primary care: comparison of 4 sampling designs]

Different sampling methodologies have been used to avoid the great amount of information which arises in Primary Health Care. The objective of this study is to compare the estimates of four sampling schemes, analyzing variables of utilization, referral activity and diagnostic morbidity, based on data obtained from consultations in a health centre over a one-year period. The percentage of error between each sample estimation and the real value for the whole data set was obtained. Sampling schemes using week periods showed the worst results (40% of error in the estimation of chronic consultations, 18% of error in the percentage of radiology requests and more than 13% in the estimation of morbidity). The findings of this study suggest that some of the sampling schemes usually applied in primary care studies have important limitations, showing the need for more research in this field.     

Transfer of microsurgical flaps without an anoxic period at the time of vascular anastomoses

Summary Technical advances in microsurgery have made frequent use of free flaps possible. One of the concerns of the microsurgeons has been the role of ischemia in flap failure. In five patients, the rectus abdominis myocutaneous flap and the radial forearm flap each having with two dominant pedicles were used employing microsurgical vascular anastomoses before section of the second pedicle. This procedure eliminates the ischemic period of the flap and consequent accumulation of free radicals and development of microthrombi, ensuring vascular perfusion during the entire operation.     

Toxic effects of nifurtimox and benznidazole, two drugs used against American trypanosomiasis (Chagas' disease)

American trypanosomiasis (Chagas' disease) is an endemic parasitic disease afflicting more than 20 million persons in Latin America. Two drugs are currently being used for treatment of the acute phase of Chagas' disease: 4-[(5-nitrofurfurylidene)amino-3-methylthiomorpholine-1,1-di oxide] (Nifurtimox; Nfx) and (N-benzl-2-nitro-1-imidazole acetamide) (Benznidazole; Bz). Nfx and Bz have serious undesirable effects, which have been reported during their clinical use, including anorexia and weight loss, nausea and vomiting, nervous excitation, insomnia, psyche depressions, convulsions, vertigo, headache, sleepiness, myalgias, arthralgias, loss of balance, disorientation, forgetfulness, paresthesias, adynamia, acoustic phenomena, peripheral neuropathies, gastralgia, mucosal edema, hepatic intolerance, skin manifestations, and intolerance to drinking alcohol. Effects in the central and peripheral nervous system of Nfx were also reproduced in animals. Signs of testicular and ovarian injury were reported for both Nfx and Bz, the effects of Bz being in general less intense than those of Nfx. Both drugs evidenced mutagenicity. In light of the present knowledge about the toxicity of Nfx and Bz, further studies on the mutagenic, teratogenic, carcinogenic, and reproductive effects of both drugs are recommended. Lack of information is particularly serious for Bz. Studies on Nfx and Bz biotransformation, activation to reactive metabolites, and potential mechanisms for their toxic effects were analyzed. Risk-benefit considerations of the use of Nfx and Bz were made and an analysis of the need for research on Chagas' disease chemotherapy was also performed.