Pesticide food poisoning from contaminated watermelons in California, 1985

Aldicarb, a carbamate pesticide, is the most potent pesticide in the market and has a LD50 of 1 mg/kg. In the United States it is illegal to use aldicarb on certain crops, e.g., watermelons, because it is incorporated into the flesh of the fruit. Once an accidental or illegal use of such a potent pesticide occurs, there is no easy way for the agricultural or public health system to protect the populace. This paper describes the impact of one such event upon the health of individuals and the institutions of California. On July 4, 1985, California and other western states experienced the largest known outbreak of food-borne pesticide illness ever to occur in North America. This was attributed to watermelons contaminated through the illegal or accidental use of aldicarb by a few farmers in one part of the state. Within California, a total of 1,376 illnesses resulting from consumption of watermelons was reported to the California Department of Health Services (CDHS). Of the 1,376 illnesses, 77% were classified as being probable or possible carbamate illnesses. Many of the case reports involved multiple illnesses associated with the same melon among unrelated individuals. Seventeen individuals required hospitalization. There were 47 reports of illness involving pregnant women, two of whom reported having subsequent stillbirths. Thirty-five of the remaining pregnant women were followed-up 9 mo after the epidemic; no additional stillbirths were found.(ABSTRACT TRUNCATED AT 250 WORDS)     

Arterial medial necrosis and hemorrhage induced in rats by intravenous infusion of fenoldopam mesylate, a dopaminergic vasodilator.

Fenoldopam mesylate, a selective, postsynaptic, dopaminergic vasodilator, was administered to rats for assessment of its clinical, toxicologic, and pathologic effects. Groups of 8 male and 8 female rats received 5, 25, 50, or 100 micrograms/kg/min by intravenous infusion for 24 hours. Groups of 12 male and 12 female rats received 2, 8, 16, or 20 mg/kg/day by intravenous injection once daily for 12 days. Tissues were examined by light microscopy. Rats infused for 24-hours with 5-100 micrograms/kg/min of fenoldopam had lesions of renal and splanchnic arteries characterized by medial necrosis and hemorrhage. None were seen in control rats or those administered the compound by intravenous injection. Arteries with four to five layers of medial smooth-muscle cells were most severely and frequently affected. Lesions were particularly severe in interlobular pancreatic arteries and subserosal gastric arteries. They occurred first at 4 hours, were present at low incidence at 8 hours, were induced in unrestrained rats, and were not caused by the experimental procedures employed. The nature and disposition of this novel arterial lesion in the rat suggests that its pathogenesis may be related to the pharmacologic activity of fenoldopam mesylate at the dopamine receptor.     

Intracranial blood velocity in head injury. A transcranial ultrasound Doppler study

We report our experience monitoring head-injured patients by means of transcranial Doppler sonography. Cerebral velocity measurements and waveforms change in a consistent pattern with the existence of intracranial pressure, and it is possible to discriminate low versus high flow states. The technique, in contrast to cerebral blood flow measurement, is reliable, atraumatic, and repeatable so that diagnostic assessments can be made and the patient can be followed for therapeutic efficacy.     

The effect of hypercapnia on a blood-brain barrier mechanism in foetal and new-born sheep.

1. The effect of marked hypercapnia (arterial PCO2 100 mmHg), nonrespiratory acidosis (pH 6-95-7-15) or hypoxia (arterial PO2 10-15 mmHg) upon penetration of labelled sucrose from blood into brain and c.s.f. has been investigated in exteriorized foetal sheep and new-born lambs. 2. In hypercapnia there was a consistent increase in c.s.f./plasma sucrose ratio after 90 min I.V. sucrose to four to five times control. Brain/plasma sucrose ratios were more variable. Usually there was an increase (up to three-and-a-half-times control); sometimes there was no change or even a decrease. The effect of hypercapnia on sucrose penetration was reversible. 3. Hypercapnia reduced c.s.f. secretion rate to approximately half the control value. Hypercapnia also caused a decrease in brain extracellular space. 4. Non-respiratory acidosis did not affect sucrose penetration. Hypoxia caused a decrease in brain/plasma sucrose ratio. 5. It is concluded that hypercapnia can cuase an increase in cerebral vascular permeability to sucrose in foetal and new-born sheep. Some possible mechanisms are discussed.     

Latest concepts in root canal treatment

This paper highlights one aspect of a presentation to be given at the BDA Conference and is written in the context of dentistry in primary care. Careful oral health assessment as a foundation to good treatment planning and quality dentistry is not new, but there are a number of important new perspectives emerging across countries and healthcare systems in terms of the content and role of such an assessment in modern dental practice.     

Dental caries in older adults

Dental caries is one of the most significant health problems facing older adults. More than half of the elderly who are dentate are affected with either coronal or root caries, and caries is the primary cause of tooth loss in this population. New materials and techniques are emerging to help with geriatric preventive and restorative needs, but ongoing vigilance for caries will be required in this population, which is experiencing increased longevity and tooth retention.