Cancer among indigenous people in the Amazon Basin of Ecuador, 1985-2000.

OBJECTIVE: To provide some of the first data on cancer incidence among indigenous people in the Amazon basin of Ecuador, and to compare that incidence with the level found among nonindigenous persons living in that same area. METHODS: From the study area 1 207 cancer cases were reported to the National Cancer Registry over the 1985-2000 period. Frequency and relative risks were calculated for the indigenous residents and for the nonindigenous residents of the area. RESULTS: Cancer of the testes and leukemia were the most common cancer types among indigenous men, and cancer of the cervix uteri was the most common among indigenous women. Indigenous men were at significantly lower risk for cancer of the stomach, skin, prostate, and lymph nodes and for leukemia than were nonindigenous men. Indigenous women were at significantly lower risk for cancer of the stomach, skin, breast, cervix uteri, and lymph nodes than were nonindigenous women. CONCLUSION: Our data from the Ecuadorian Amazon indicate the need to develop appropriate mechanisms to register the indigenous population in the national census as well as in the National Cancer Registry. Also needed are cancer early detection programs, more health education efforts, and stronger health services that are adapted to the local conditions. Future research should focus on factors that may help to explain the different cancer patterns found among indigenous persons and nonindigenous persons.     

Influence of number of pregnancies and total breast-feeding time on bone mineral density

OBJECTIVE: To analyze how the number of pregnancies and total breast-feeding time influence bone mineral density. METHODS: 50 healthy women aged 35 to 40 years were studied. Weight, height, number of term pregnancies, time since last pregnancy and breast-feeding time were analyzed. They were divided in three groups as follows: I: nulligravidas; II: with term pregnancies, but no breast-feeding; III: with term pregnancies, with breast-feeding. Bone absorptiometry was done on all, at lumbar column and femur. The WHO criteria were used to define osteopenia and osteoporosis. Comparison among the groups was done with Student's t-test for independent samples, and simple regression analysis was done for number of gestations, total breast-feeding time, time since last birth, and T-score at lumbar column and femur. RESULTS: The women were divided as follows: 15 in group I, 15 in group II, and 20 in group III. The average age was 37.7 +/- 1.5 years. No differences were found among the three groups in analyzed variables, when comparing bone mineral density, T- and Z-scores in L1-L4 average, femoral neck, trochanter, and Ward's triangle. There was no correlation among the number of gestations, total breast-feeding time, time since last birth, or T-scores at lumbar column and femur. CONCLUSION: The number of pregnancies and breast-feeding time do not affect bone mineral density.     

6-methylapigenin and hesperidin: new valeriana flavonoids with activity on the CNS

Valerian is an ancient tranquillizing drug obtained from the underground organs of several Valeriana species. Its active principles were assumed to be terpenoids in the form of valepotriates and/or as components of the essential oil. However, unknown active compounds were not discarded and synergic effects were suspected.We have recently isolated 6-methylapigenin (MA) from Valeriana wallichii and proved that it is a benzodiazepine binding site (BDZ-bs) ligand [Planta Med. 68 (2002) 934].The present paper is the first report of the presence of 2S(-)-hesperidin in valeriana and describes that it has sedative and sleep-enhancing properties. MA, in turn, was found to have anxiolytic properties and was able to potentiate the sleep-enhancing properties of hesperidin (HN).MA and HN are new members of the growing family of natural flavonoids with activity on the CNS, and their properties suggest that they are promising drug leads in the field.     

Improving immunization coverage in rural areas of Ecuador: a cost-effectiveness analysis

This study describes the costs and outcomes of two different immunization strategies used by the district level of the Ministry of Health carried out between 1993 and 1995 in Low-Napo area, Napo, Ecuador. One was centrally planned and managed by the District Hospital (DH) and the other planned and implemented together with community health workers (CHW). Immunization costs were estimated directly from survey records and communication of the Ministry of Health. Outcomes information was abstracted from the vaccination statistics of the Napo Province Health Department for 1993/1995. Community health workers strategy immunized 113 children with an average cost of US $32 per child. District Hospital strategy had an average cost of US $777.6 per immunized child.Thus, CHWs strategy is more effective and less costly than the DH strategy.This study shows that in order to maximize the cost-effectiveness of immunization, it is important to involve community participation in both planning and implementation. Continuous follow-up and evaluation of the immunization programme and further research on vaccine efficacy are necessary in order to maintain these results.     

Fine-tuning neuromodulation by adenosine

In addition to its direct pre- and postsynaptic actions on neurones, adenosine is rich in nuances of priming, triggering and inhibiting the action of several neurotransmitters and neuromodulators. These actions are mediated by membrane adenosine receptors (A1, A2 and A3) and involve receptor-receptor interactions, which require, in most cases, the formation of an intermediate second messenger. The harmonic way adenosine builds its influence at synapses to control neuronal communication is operated through fine-tuning, 'synchronizing' or 'desynchronizing' receptor activation for neuropeptides such as calcitonin gene-related peptide and vasoactive intestinal peptide, nicotinic acetylcholine autofacilitatory receptors, NMDA receptors, metabotropic glutamate receptors, as well as its own adenosine receptors.     

Tonic activation of A(2A) adenosine receptors unmasks, and of A(1) receptors prevents, a facilitatory action of calcitonin gene-related peptide in the rat hippocampus

1. We investigated how manipulations of the degree of activation of adenosine A(1) and A(2A) receptors influences the action of the neuropeptide, calcitonin gene-related peptide (CGRP) on synaptic transmission in hippocampal slices. Field excitatory post-synaptic potentials (EPSPs) from the CA1 area were recorded. 2. When applied alone, CGRP (1 - 30 nM) was without effect on field EPSPs. However, CGRP (10 - 30 nM) significantly increased the field EPSP slope when applied to hippocampal slices in the presence of the A(1) receptor antagonist, 1,3-dipropyl-8-cyclopenthyl xanthine (DPCPX, 10 nM), or in the presence of the A(2A) adenosine receptor agonist CGS 21680 (10 nM). 3. The A(2A) receptor antagonist, ZM 241385 (10 nM) as well as adenosine deaminase (ADA, 2 U ml(-1)), prevented the enhancement of field EPSP slope caused by CGRP (30 nM) in the presence of DPCPX (10 nM), suggesting that this effect of CGRP requires the concomitant activation of A(2A) adenosine receptors by endogenous adenosine. 4. The protein kinase-A inhibitors, N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA-1004, 10 microM) and adenosine 3',5'-cyclic monophosphorothioate, Rp-isomer (Rp-cAMPS, 50 microM), as well as the inhibitor of ATP-sensitive potassium (K(ATP)) channels, glibenclamide (30 microM), prevented the facilitation of synaptic transmission caused by CGRP (30 nM) in the presence of DPCPX (10 nM), suggesting that this effect of CGRP involves both K(ATP) channels and protein kinase-A. 5. It is concluded that the ability of CGRP to facilitate synaptic transmission in the CA1 area of the hippocampus is under tight control by adenosine, with tonic A(1) receptor activation by endogenous adenosine 'braking' the action of CGRP, and the A(2A) receptors triggering this action.