Hot beverages and oesophageal cancer in southern Brazil: a case-control study

There is a cluster of high-incidence areas of oesophageal cancer in south-eastern South America, including Southern Brazil, Uruguay and parts of Argentina. The present case-control study investigated the hypothesis that this may be due to the drinking of maté, a traditional beverage drunk at a very high temperature, and also studied the role of other known risk factors such as alcohol and tobacco. Cases (171) and age- and sex-matched controls (342) were recruited from hospitals in the State of Rio Grande do Sul in Southern Brazil. The crude odds ratio for daily maté drinkers was 1.92 relative to those drinking less frequently than daily (p = 0.006). Other risk factors included the drinking of cachaça (a sugar cane spirit), smoking, rural residence, low fruit consumption and high intake of meats. After adjustment for these variables through conditional logistic regression, the odds ratio associated with daily maté drinking was reduced to 1.47 (90% CI = 0.87 - 2.50). Although the study failed to provide evidence of a strong association between maté and oesophageal cancer, the cluster of high rates could be explained by relative risks of the magnitude observed. This is due to the fact that approximately 70% of adult males and 50% of females are daily drinkers. In addition, this study revealed that alcohol, tobacco smoking and rural residence are the main risk factors for oesophageal cancer in this population and the fruit consumption confers some degree of protection.     

Phospholipid determination in platelets,plasma and red cells of patients with chronic myeloproliferative disorders

Abstract: Red cell phospholipids (PLs) were assessed in 11 patients with essential thrombocythemia and 5 patients with polycythemia vera. Platelet and plasma PLs were also determined in 10 of these patients, and the results were compared with studies performed in 16 healthy volunteers. The amount of platelet PLs in patients was similar to controls (556 ± 90 nmol/10⁹cells, versus 481 ± 91 nmol/10⁹cells), as was the percentage of the main specimens of these compounds, including phosphatidylserine (11.1 ± 0.8%), which is relevant for platelet procoagulant activity. We did not find differences between red cell PLs of patients (300 ± 60 nmol/10⁹cells), versus controls (289 ± 71 nmol/10⁹cells), and the sphingomyelin/phosphatidylcholine ratio in these cells was the same in both groups (0.75 ± 0.1). Finally, we did not detect any alteration in the amount of plasma PLs specimens.     

Quantitative (82)Rb PET/CT: development and validation of myocardial perfusion database.

The use of myocardial perfusion (82)Rb PET/CT studies continues to increase but its accuracy using database quantification methods for the diagnosis of coronary artery disease (CAD) has not been established. METHODS: A sex-independent normal database and criteria for abnormality for rest-stress (82)Rb PET/CT myocardial perfusion imaging were developed and validated by evaluation of 281 patients (136 females: mean age +/- SD, 63.3 +/- 13.3 y; 145 males: mean age +/- SD, 63.9 +/- 12.8 y) who underwent a rest-adenosine stress (82)Rb PET/CT study. These patients were divided into 3 groups: (a) healthy group: 30 patients, with <5% likelihood of CAD (low likelihood [LLK]) based on sequential Bayesian analysis; these patients were used to generate the normal distribution; (b) pilot group: 174 patients; these patients were used to determine the optimal criteria for detecting and localizing the perfusion abnormality; and (c) validation group: 76 patients (23 with LLK of CAD and 53 who underwent coronary angiography; these patients were used for prospective validation. RESULTS: Of the 53 patients who underwent coronary angiography, 8 had <50% stenosis and 45 patients had at least one stenosis > or =50% in one major artery. Fifteen patients had single-vessel disease, 17 had double-vessel disease, and 13 had triple-vessel disease. The prospective validation shows a normalcy rate of 78% (18/23) for global CAD. The analyses by individual arteries show a normalcy rate of 96% (22/23) for the left anterior descending coronary artery, 96% for the left circumflex coronary artery (22/23), and 100% for the right coronary artery (23/23). The overall sensitivity for detection of CAD (> or =50% stenosis) was 93% (42/45). The overall specificity for detection of the absence of CAD (< or =50% stenosis) was 75% (6/8). Also, the positive predictive value for global CAD was 95% (42/44), the negative predictive value was 67% (6/9), and the accuracy was 91% (48/53). CONCLUSION: The quantitative (82)Rb PET/CT database created and validated in this study is highly accurate for the detection and localization of CAD. Physicians should consider using the quantitative output of these algorithms as decision support tools to aid with image interpretation.     

Dexamethasone in the treatment of meningeal leukemia

To determine if dexamethasone has a role in the treatment of meningeal leukemia, 8 consecutive patients with acute lymphoblastic and signs or symptoms of CNS were included in the study. After the confirmation of leukemic blast cells on cerebrospinal fluid, they received intrathecal and IV dexamethasone; 3 days later the patients received “triple” intrathecal chemotherapy with dexamethasone, methotrexate and cytarabine, and the spinal fluid was studied again. All patients had good clinical response and 7 out of the 8 patients showed reduction on the CSF cell count after the use of dexamethasone alone. The results suggest that dexamethasone is a lympholytic agent that could play a more active role in the prevention and therapy of meningeal leukemia and should be preferred over hydrocortisone in the so called “triple” intrathecal chemotherapy for the prevention and treatment of CNS leukemia. © 1995 Wiley-Liss, Inc.     

Angiotensin-(1–7) stimulates water transport in rat inner medullary collecting duct: evidence for involvement of vasopressin V2 receptors

The peptide angiotensin-(1–7) [Ang-(1–7)] is known to enhance water transport in rat inner medullary collecting duct (IMCD). The aim of this study was to determine the mechanism of the Ang-(1–7) effect on osmotic water permeability (P _f). P _f was measured in the normal rat IMCD perfused in vitro in presence of agonists [Ang-(1–7), arginine vasopressin (AVP) and Ang-(3–8)], and antagonists of the angiotensin and the vasopressin cascade. Ang-(1–7), but not Ang-(3–8), increased P _f significantly. The effect of Ang-(1–7) on P _f was abolished by its selective antagonist, A-779, added before or after Ang-(1–7). Prostaglandin E₂ and the protein kinase A inhibitor H8 also blocked the Ang-(1–7) effect. Blockade of vasopressin V₁ receptors by antagonists did not change the Ang-(1–7) effect, but pre-treatment with a V₂ antagonist abolished the effect of Ang-(1–7) on P _f. Similarly, pre-treatment with A-779 inhibited AVPs effect on P _f. Forskolin-stimulated P _f was blocked both by A-779 and by the V₂ antagonist. Finally, Ang-(1–7) increased cAMP levels in fresh IMCD cell suspensions whilst the forskolin-stimulated cAMP synthesis was decreased by A-779 and the V₂ antagonist. These data provide evidence that Ang-(1–7) interacts via its receptor with the AVP V₂ system through a mechanism involving adenylate-cyclase activation.     

Antimutagenic activity of extracts of natural substances in the Salmonella/microsome assay

Scientific information regarding plants used in folk medicine in the form of teas and their effect on human health or on genetic material has been the subject of many different types of investigation. The antimutagenic activity of two plants Maytenus ilicifolia and Peltastes peltatus, both rich in compounds of the flavonoid and tannin groups and frequently employed in folk medicine, was studied. Antimutagenicity was determined against known mutagenic substances (4-oxide-1-nitroquinoline, sodium azide, 2-nitrofluorene, aflatoxin B(1), 2-aminofluorene and 2-aminoanthracene), using the Salmonella/microsome assay. Infusions of P.peltatus showed high cytotoxicity and a co-mutagenic effect for induction of base pair substitution mutations with 4-oxide-1-nitroquinoline (-S9 mix). Infusions of M.ilicifolia produced similar effects for frameshift and base pair substitution mutations. With the mutagens 2-nitrofluorene (TA98) and sodium azide (TA100) no significant enhancement effects (co-mutagenic effects) were observed and inhibition of mutagenic activity and cytotoxicity were also diminished. In assays evaluating antimutagenic activity in the presence of metabolic activation utilizing S9 mix, high and significant inhibition of aflatoxin B(1)-, 2-aminofluorene- and 2-aminoanthracene-induced mutagenicity was observed in the presence of the infusions using both TA98 and TA100 and employing doses ranging from 25 to 500 mg/plate. Seventy-five percent of the doses tested exhibited a significant or suggestive decrease in induced mutagenicity with the infusion of M.ilicifolia. With the infusion of P.peltatus significant or suggestive antimutagenic responses were observed with 50% of the doses evaluated. Complexity was clearly noted in the responses observed in the interaction of aqueous extracts of M.ilicifolia and P.peltastes with the genetic material and metabolites generated by the S9 mix played an important role in the protection of DNA.