Urban hospital cesarean section delivery rates in Paraíba State, Brazil, 1977-81.

Paraíba State, Brazil is one of the poorest areas in that country; many of the hospitals are not high quality and medical training is not comparable to that of developed countries. Nevertheless, the rate of cesarean section delivery in urban hospitals has risen from 19.0 per cent in 1977 to 28.5 in 1981. Despite the larger volume of obstetric services in government hospitals, these hospitals had lower cesarean section rates than private hospitals, both profit and non-profit.     

The response to carbogen breathing in experimental tumour models monitored by gradient-recalled echo magnetic resonance imaging.

Gradient-recalled echo magnetic resonance imaging (GRE MRI), which gives information on blood flow and oxygenation changes (Robinson SP, Howe FA, Griffiths JR 1995, Int J Radiat Oncol Biol Phys 33: 855), was used to observe the responses of six rodent tumour models to carbogen breathing. In one transplanted rat tumour, the Morris hepatoma 9618a, and a chemically induced rat tumour, the MNU-induced mammary adenocarcinoma, there were marked image intensity increases, similar to those previously observed in the rat GH3 prolactinoma. In contrast, the rat Walker carcinosarcoma showed no response. In two mouse tumours, the RIF-1 fibrosarcoma and the human xenograft HT29, carbogen breathing induced a transient fall in signal intensity that reversed spontaneously within a few minutes. The rat GH3 prolactinoma was xenografted into nude mice, and an increase in image intensity was found in response to carbogen, suggesting that any effects that carbogen may have had on the host were not significant determinants of the tumour response. The increases in GRE image intensity of the MNU, H9618a and GH3 tumours during carbogen breathing are consistent with increases in tumour oxygenation and blood flow, whereas the responses of the RIF-1 and HT29 tumours may be the result of a transient steal effect followed by homeostatic correction.     

Clinical research and drug development in Latin America: weighing the pros and cons, talking about the future.

Two decades ago, clinical trials were carried out only in developed countries. Drug development and the need to speed up clinical trials lead the conduction of clinical trials to other countries. Among the regions of interest, Latin America (LA) has played its role successfully. LA has a large number of naive patients, qualified investigators, established regulatory systems and reasonable costs. Furthermore, LA might be also considered as a new option for any company looking for international patterns on drug research and development. The region has good professionals with scientific qualifications, well-established multinational pharmaceutical bases and an expansive pharmaceutical regional market. This work summarizes the recent advances that have occurred in drug research and development in the region and the expansion of the clinical trial market in the last couple of years.     

Analysis of cytogenetic damage induced in cultured human lymphocytes by the pyrethroid insecticides cypermethrin and fenvalerate

Two pyrethroid insecticides, cypermethrin and fenvalerate, weretested for their ability to induce chromosome structural aberrationsand sister chromatid exchanges in cultured human peripheralblood lymphocytes. Fenvalerate, but not cypermethrin, increasedthe frequencies of chromosome-type aberrations and sister chromatidexchanges. In addition, both pyrethroids affected the cell cyclecausing a decrease in the proliferative rate index at concentrations> 10 µg/ml. ¹To whom correspondence should be addressed     

Head injury mortality in two centers with different emergency medical services and intensive care

The authors report data collected prospectively on 551 cases of head injury in New Delhi, India, and 822 cases in Charlottesville, Virginia. The mortality rate, adjusted for initial severity of injury, was 11.0% in New Delhi versus 7.2% in Charlottesville (p less than 0.02). There was a striking similarity in mortality rates at both centers when comparing patients with the least severe head injuries and those with the most severe injuries according to the motor score of the Glasgow Coma Scale (GCS M). However, in the group with an abnormal but purposeful motor response (GCS M = 5), the mortality rate was 12.5% in New Delhi versus 4.8% in Charlottesville (p less than 0.01). The relative absence of prehospital emergency care and the delay in admission after head injury in New Delhi are cited as two possible causes for the differences in mortality rates in this subgroup of patients with "moderate" head injuries.     

Adenosine administration produces an antidepressant-like effect in mice: evidence for the involvement of A1 and A2A receptors

This study investigated the effect of adenosine in the forced swimming test (FST) and the tail suspension test (TST) in mice, and the contribution of adenosine A1 and A2A receptors to adenosine's antidepressant-like effect. The immobility time in the FST was reduced by adenosine given either by i.p. (5-10 mg/kg) or i.c.v. (0.01-10 microg/site) route. Adenosine (1-10 mg/kg, i.p.) also produced an antidepressant-like effect in the TST. No treatment affected locomotion in an open-field. The anti-immobility effect of adenosine (10 mg/kg, i.p.) in the FST was prevented by i.p. pretreatment of mice with caffeine (3 mg/kg), DPCPX (2 mg/kg) and ZM241385 (1 mg/kg). CHA (0.05 mg/kg, i.p.) and DPMA (1-5 mg/kg, i.p.) also produced an antidepressant-like effect in the FST. This is the first report of an antidepressant-like effect of adenosine in mice, apparently mediated through an interaction with A1 and A2A receptors.     

Ontogenetic profile of glutamate uptake in brain structures slices from rats: sensitivity to guanosine

The excitotoxicity of the neurotransmitter glutamate has been shown to be connected with many acute and chronic diseases of the CNS. High affinity sodium-dependent glutamate transporters play a key role in maintaining adequate levels of extracellular glutamate. In the present study, we used slices of striatum, hippocampus and cortex from rat brain to describe the in vitro profile of glutamate uptake during development and ageing, and its sensitivity to guanosine. In all structures, glutamate uptake was higher in immature animals. There was a maximum decrease in glutamate uptake in striatum and hippocampus in 15-month-old rats, which later increased, while in cortex there was a significant decrease in rats aged 60 days old. The effect of guanosine seems to be age and structure dependent since the increase in basal glutamate uptake was only seen in slices of cortex from 10-day-old animals.