External quality assessment of assays of lead in blood

The operation and results of the United Kingdom External Quality Assessment Scheme for Lead in Blood, which currently has about 140 participants within and outside the U.K. are described. The choice of specimens, scheme design, and scoring of performance are discussed, as is the validity of the consensus values used as a basis for the scoring. There has been a continued improvement in performance as assessed by this program, some of which appears to have been stimulated by the introduction of Variance Index scoring. The relative performance of the methods for assaying lead in blood is also examined.

Stafne's bone cavity: a review of the literature and report of two cases

This paper reports two cases of Stafne's bone cavity, one of which shows apparent regression over a period of 8 years: an unusual feature that has not previously been reported. A comprehensive review of the literature dealing with this well demarcated mandibular radiolucency of unknown aetiology accompanies these two case reports.

Thalidomide in severe orogenital ulceration

Thalidomide was given to 15 patients with severe orogenital ulceration (OGU). 4 patients underwent a double-blind controlled trial with glutethimide as placebo and 11 were treated openly. Treatment with thalidomide produced complete resolution of ulcers in 14 and significant improvement in the remaining patient. No peripheral neuropathies developed. Patients did not respond to glutethimide. Thalidomide is an effective treatment for severe OGU. Adequate contraceptive measures should be taken during treatment.

Networking in International Agricultural Research

Informal and structured collaboration is becoming increasingly common in international agricultural research. A network approach to research generally reduces costs, minimizes duplication, and boosts efficiency. Collaborative teams, sometimes involving hundreds of scientists in dozens of countries, have been formed to tackle numerous constraints to boosting food production. Networks have been established to test crop germplasm over a broad range of environments, explore ways of boosting the efficiency of fertilizer use, upgrade disease resistance in livestock, and identify socioeconomic obstacles to improved agricultural output. The benefits of networking are especially valuable to countries with limited funds and scientific manpower.

Weight control in the athlete

Altering body composition either through reducing body fat or increasing muscle mass is a frequent and very important concern of large numbers of young athletes. When efforts to induce these body changes are approached with sound principles of nutrition and training, the resulting changes in body composition can make the desired contribution to health and fitness as well as contributing to increasing the athlete's performance potential. Any attempt to alter body composition must be planned over a significant time period, making it essential to initiate the program several weeks prior to the competing season. Significant increases or decreases in any body tissue component cannot be safely accomplished in a brief period. Supervision by a physician or another legitimate health professional is highly recommended to protect the motivated athlete from the abuses of faddists, quacks, and nutrition charlatans. The proper educational information regarding the ineffectiveness and hazards of drug use by the athlete are also to be dealt with. Having achieved a desired body composition, the athlete will recognize an achieved weight as his or her desired competing weight. Monitoring body weight two or three times weekly during the season will identify any involuntary changes in body weight that, if continued, will inevitably compromise athletic performance.

Bifid mandibular condyle

Two cases of unilateral bifid mandibular condylar head are reported. A review of the literature showed that only four cases had been reported as occurring in living patients, although another twenty-two cases have been reported in dried skull or cadaver material. A brief discussion of the possible etiology is given.

Nutrition and athletic performance

Athletes have a keen interest in informed nutrition counsel. They recognize that food intakes are important determinants of energy availability and body fitness. For many sports, participation will prompt a general upgrading of dietary practices and nutrition-related well-being. Specific nutrition guidance can prevent abuses and can enhance the performance of the athlete and the team in many sports.

Comparability ratios by age: based on deaths of Metropolitan policyholders

Comparability ratios based on 42,229 deaths of Metropolitan policyholders in 1979 were computed by age between the 8th and 9th revision ICD codes for 72 selected causes of death. Comparability ratios by age are not available elsewhere. Except for accidents and adverse effects, the comparability ratios for the major causes of death at all ages combined were in close agreement with those computed by the National Center for Health Statistics.

Iron repletion decreases maximal exercise lactate concentrations in female athletes with minimal iron-deficiency anemia

We studied the effect of 2 weeks of iron therapy on exercise performance and exercise-induced lactate production in trained women athletes: six control subjects with normal parameters of iron status and nine with mild iron-deficiency anemia defined by low Fe/TIBC, ferritin, and minimally decreased Hgb values. Iron therapy improved the abnormal measures of iron status and low Hgb in the second group to normal. Exercise performance in a progressive work-exercise protocol on a bicycle ergometer to exhaustion was unchanged after iron therapy in both groups; however, blood lactate levels at maximum exercise in the iron-deficient group decreased significantly from 10.3 +/- 0.6 mmol/L before therapy to 8.42 +/- 0.7 after therapy (p less than 0.03). The control subjects did not significantly alter lactate levels after maximal exercise on iron compared to placebo: 8.3 +/- 0.8 mmol/L vs. 8.5 +/- 0.7. Although there was not a significant difference in maximum exercise performance after iron therapy, these data support animal experiments implying that iron may play a role in oxidative metabolism and that minimal decreases in Hgb may impair arterial oxygen content enough to affect aerobic metabolism. In addition, these findings may have important implications for competitive women athletes in whom mild iron deficiency may go unnoticed.

Renal dysfunction in cadmium smelters: relation to in-vivo liver and kidney cadmium concentrations

Biochemical indicators of renal dysfunction have been compared with liver and kidney cadmium levels measured by neutron activation analysis in a group of 37 cadmium smelters. Higher than normal concentrations of cadmium in the liver reflect past exposure; they were associated with evidence of renal dysfunction in workers exposed to cadmium for more than 10 years. A small group of 6 workers exposed to cadmium for only a short time (mean = 4.6 years) had high hepatic cadmium concentrations but normal renal function. Longitudinal studies are required to establish the natural history of renal dysfunction following cadmium accumulation in industrial workers.

Crop Germplasm Conservation and Developing Countries

Loss of the genetic diversity of some of the world's crops has accelerated in recent decades, with many crops becoming increasingly susceptible to diseases, pests, and environmental stresses. A global network of gene banks has therefore been established to provide plant breeders with the genetic resources necessary for developing more resistant crops that will enable farmers to maintain high yields. Most of these gene banks now store the germplasm of only the major crops such as cereals, potatoes, and grain legumes. Cultivated varieties of these crops are conserved as well as wild species that might otherwise become extinct. Tropical cash crops such as bananas and coconuts are also important food crops in many Third World countries, and more effort needs to be made to conserve the germplasm of these crops as well as of other important plants such as plantation crops, medicinal herbs, and fruit and timber trees.

Alcohol use and iron status in pregnant women

Iron status, assessed by ferritin (ng/ml), transferrin saturation (%), and hemoglobin (g/100 ml), was examined in a sample of 1398 women from blood samples drawn at their first prenatal visit and in 712 of these women later at their 32-week prenatal visit. Self-reported alcohol use (average ounces of absolute alcohol consumed per day around the time of conception) was not systematically related to iron status. Furthermore, the proportion of iron-depleted or anemic women did not vary according to different levels of alcohol use. An exception is noted in a small group of nine very heavy drinkers, reporting eight or more drinks per day, who, at 32 weeks gestation, had a higher proportion of iron depletion but not anemia. It was concluded that at least in a sample of primarily middle class women receiving good prenatal care, iron depletion and/or anemia probably do not explain the alcohol-related adverse pregnancy outcomes that have been reported previously. Nevertheless, results from several very heavy drinkers suggest that the iron status of pregnant alcoholic women should be investigated further.

Teratogenicity study of ethylene glycol in rats

Ethylene glycol was administered in the diet to pregnant Fischer 344 rats on days 6 through 15 of gestation. Target dosage levels were 1.0, 0.2, 0.04, and 0.00 g/kg/day. There was no maternal toxicity, embryotoxicity, or increased incidence of malformations in fetuses from doses dams. Positive control dams received 500 mg/kg of hydroxyurea on gestation day 11 and had fetuses with numerous soft tissue and skeletal malformations. Results are interpreted as preliminary indication of lack of teratogenicity of ethylene glycol.

Agricultural research and Third World food production

By the close of this century the world may have to feed as many as 2 billion additional people. Most of them will be born in developing countries, especially in marginal lands ill-suited for food production. This article focuses on efforts by the International Agricultural Research Centers to increase food production in the Third World and addresses the social and ecological issues raised by the introduction of high-yielding varieties into fertile Third World lands and describe how varieties are being tailored for introduction into marginal areas.