Poisoning mortality in the United States: comparison of national mortality statistics and poison control center reports.

STUDY OBJECTIVE: To determine whether the distributions of age and poisoning categories for poisoning deaths are similar in death certificates as compiled by the National Center for Health Statistics (NCHS) and US poison control centers as reported by the Toxic Exposure Surveillance System (TESS). METHODS: Data from both databases for 1994 were examined. Mortality data from NCHS were identified by applicable E-codes of the International Classification of Diseases-ninth revision (ICD-9). All fatalities described in the TESS report were coded to conform to the ICD-9 system. RESULTS: A total of 16,527 poisoning deaths were recorded by NCHS; 766 deaths were reported by TESS. For NCHS and TESS, respectively, the age distribution of unintentional drug poisonings (N=7,823; 155) and unintentional non-drug poisonings (N=1,234; 102) differed (P <.001), whereas those for intentional poisonings (N=5,320; 413) did not differ significantly. In the NCHS and TESS data sets, respectively, the relative distribution of death circumstances differed (P <.001) for unintentional drug poisonings (47% versus 20%), unintentional non-drug poisonings (8% versus 14%), intentional poisonings (32% versus 54%), and unknown or other circumstances (13% versus 12%). The distributions of poisoning circumstances and age categories were dependent on the data source (P <.001). There was no statistical agreement between the data sets in rankings of the 12 most frequent ICD-9 codes and toxins associated with poisoning deaths. CONCLUSION: Deaths reported in TESS represent 5% of the poisoning deaths tabulated by NCHS. Differences observed in the 2 data sets may lead to differing health policies to address poisoning hazards.

When patients become cyanotic: acquired methemoglobinemia.

BACKGROUND: The authors conducted literature review to create a heightened awareness of the potential for developing toxic methemoglobinemia from local anesthetics. Methemoglobin normally is present in the blood at levels less than 1 percent. Levels may become toxic as hemoglobin is oxidized to methemoglobin after local anesthetics such as benzocaine and prilocaine are administered. TYPES OF STUDIES REVIEWED: The authors searched the medical and pharmaceutical industry literature. They found and reviewed case studies of incidences of methemoglobinemia that resulted from local anesthetic overdoses. RESULTS: Cases of local anesthetic-induced methemoglobinemia in dental practice are under-recognized and rare. Reported cases of prilocaine-induced methemoglobinemia have resulted in recent changes in some prilocaine literature. These changes include maximum recommended doses for patients of various weights. CLINICAL IMPLICATIONS: Dentists should identify patients who are at increased risk of developing methemoglobinemia before administering local anesthetics. They also should follow new recommended dosing guidelines for prilocaine and be aware of symptoms of this adverse reaction.

Reduction of enhanced mammary carcinogenesis in LA/N-cp (corpulent) rats by energy restriction.

Restriction of energy intake significantly reduces mammary tumorigenesis in normal rats exposed to carcinogens. Genetically obese LA/N-cp (corpulent) female rats were given 7,12-dimethylbenz[a]anthracene and fed purified diets ad libitum or restricted to 60% of the ad libitum caloric intake. Phenotypically lean littermates were also fed ad libitum. Obese animals developed large mammary tumors more rapidly than genetically normal rats so that 100% of the animals had tumors in less than 16 weeks. Only 21% of the lean animals developed tumors; the energy restricted obese animals had a tumor incidence of 27%. Although obese rats fed the restricted diet weighed significantly less than those fed ad libitum, percent body fat was not reduced, indicating that lean tissue was affected more. Obese animals were markedly hyperinsulinemic (1003 +/- 193 microunits/ml) and energy restriction reduced this to 328 +/- 41; the lean animals had insulin levels of 12 +/- 2. Tumor-bearing rats had higher insulin levels than rats without tumors. These data suggest that body fatness is not directly associated with risk of carcinogenesis. Lean body mass, adipose tissue mass, and their interaction with insulin in its capacity as a growth factor rather than body fatness per se may be determinants of tumor promotion.

Inhibition of DMBA-induced mammary tumorigenesis by caloric restriction in rats fed high-fat diets.

Most previous studies on the inhibiting effect of caloric restriction during promotion of DMBA-induced mammary carcinogenesis have used low to moderate levels of dietary fat, i.e., about 4 to 14% by weight. The current study was designed to test whether a moderate degree of caloric restriction, 25%, would inhibit tumor growth in rats fed the equivalent of 20% dietary fat which approximates human consumption in affluent countries. Rats were fed diets ad libitum that contained 5, 15 or 20% corn oil. Groups of rats were pair-fed to the last 2 groups, but subjected to a 25% caloric restriction. These groups were fed 20 or 26.7% corn oil so that absolute fat intake in the paired groups was identical. Significant inhibition of tumor incidence, tumor weight, tumor burden, body fat deposition, and fasting serum insulin were observed in the 2 calorically restricted groups. We conclude that moderate caloric restriction is significantly more effective in inhibiting tumor growth than is the promoting effect of diets high in fat. Total body weight, body fat and serum insulin concentrations may be better correlates of risk of developing mammary tumors than is dietary fat.