Cadmium-induced cancers in animals and in humans

Discovered in the early 1800s, the use of cadmium and various cadmium salts started to become industrially important near the close of the 19th century, rapidly thereafter began to flourish, yet has diminished more recently. Most cadmium used in the United States is a byproduct from the smelting of zinc, lead, or copper ores, and is used to manufacture batteries. Carcinogenic activity of cadmium was discovered first in animals and only subsequently in humans. Cadmium and cadmium compounds have been classified as known human carcinogens by the International Agency for Research on Cancer and the National Toxicology Program based on epidemiologic studies showing a causal association with lung cancer, and possibly prostate cancer, and studies in experimental animals, demonstrating that cadmium causes tumors at multiple tissue sites, by various routes of exposure, and in several species and strains. Epidemiologic studies published since these evaluations suggest that cadmium is also associated with cancers of the breast, kidney, pancreas, and urinary bladder. The basic metal cationic portion of cadmium is responsible for both toxic and carcinogenic activity, and the mechanism of carcinogenicity appears to be multifactorial. Available information about the carcinogenicity of cadmium and cadmium compounds is reviewed, evaluated, and discussed.     

Vitamin A levels and severity of measles. New York City.

Recent studies show that vitamin A levels decrease during measles and that vitamin A therapy can improve measles outcome in children in the developing world. Vitamin A levels of children with measles have not been studied in developed countries. We therefore measured vitamin A levels in 89 children with measles younger than 2 years and in a reference group in New York City, NY. Vitamin A levels in children with measles ranged from 0.42 to 3.0 mumol/L; 20 (22%) were low. Children with low levels were more likely to have fever at a temperature of 40 degrees C or higher (68% vs 44%), to have fever for 7 days or more (54% vs 23%), and to be hospitalized (55% vs 30%). Children with low vitamin A levels had lower measles-specific antibody levels. No child in the reference group had a low vitamin A level. Our data show that many children younger than 2 years in New York City have low vitamin A levels when ill with measles, and that such children seem to have lower measles-specific antibody levels and increased morbidity. Clinicians may wish to consider vitamin A therapy for children younger than 2 years with severe measles. Additional studies of vitamin A in measles and other infectious diseases, and in vaccine efficacy trials, should be done.     

Length polymorphism of heterochromatic segment of the Y chromosome in boys with acute leukemia

The extent of length polymorphisms of the heterochromatic and euchromatic segment of the human Y chromosome were investigated in 15 boys with acute leukemia and were compared with 15 normal controls. A greater value of the Yh/F index in relation to controls was established (P < 0.05). The length of the euchromatic segment was also shorter in the patients than the controls (P < 0.05).     

Effects on Plasma Glucose Concentration of Light-for-date Infants and Infants of Diabetic Mothers of Feeds Supplemented with a Glucose Polymer

ABSTRACT. Serial plasma glucose estimations were performed in 44 light-for-date infants and 17 infants of diabetic mothers fed 2, 3 or 4-hourly with feeds containing 10 % additional carbohydrate in the form of a glucose polymer (Caloreen). In the infants fed 2 and 3-hourly, plasma glucose was higher following the high carbohydrate feeds, particularly immediately before the next feed was due. Given 4-hourly, the high carbohydrate feed had little effect in most light-for-date infants, and in one light-for-date infant and two infants of diabetic mothers the plasma glucose was lower at the end of 4 hours than following normal formula. It is concluded that the addition of glucose polymer to feeds given 2 and 3 hourly has a potentially useful effect in neonates at risk of developing hypoglycaemia, but it cannot be used to increase the feed interval to 4 hours.     

Pharyngeal diverticula

A series of 73 hypopharyngeal (Zenker's) diverticula is reported and the choice of treatment and technique of excision are discussed. The problems of excision include operation on an infected site with limited access but few patients are unfit for the procedure. Preoperatively the sac should be packed and the oesophagus stented. The side of approach is unimportant as the condition is essentially midline. Cricopharyngeal myotomy appears to reduce the recurrence rate, possibly by improving coordination of pharyngeal contraction and upper oesophageal relaxation. The use of electrocoagulation is not recommended as 20% of patients require repeated general anaesthesia and the procedure fails in 13%. For all but the smallest pouches, excision is the treatment of choice.     

IARC monographs,industry influence,and upgrading,downgrading, and under-grading chemicals: a personal point of view. International Agency for Research on Cancer

The first IARC Monographs Volume was distributed in 1972, and over the 23 years through 1993, under the leadership of Dr Lorenzo Tomatis, 59 IARC Monographs were completed. During 1977-1979 the author was privileged to lead the program for Volumes 15-22, and participated in the pioneering development of the LARC Preamble and Categories of Evidence. During this era other Chiefs of the IARC Monographs included Claus Agthe, Harri Vainio, Antero Aitio, and Julian Wilbourn. Since then (starting with Volume 62: 1995), a new attitude seems to have pervaded the IARC Monographs program, resulting in an increasing influence of or partiality for industry and a diminishing dedication to public and occupational health and safety concerns, and for primary prevention. Some of this attitude comes from an apparent misguided scientific zest prematurely to endorse purported or hypothetical mechanisms of chemical carcinogenesis or modes of action of chemicals causing cancer in experimental animals. These speculations are in turn used cavalierly to discount the value of experimental evidence for predicting probable carcinogenicity to humans. Most often this is accomplished by opining that the mechanism(s) of carcinogenicity in animals would not be operative in humans. End of explanation. Examples whereby the IARC has recently "down-graded" or "under-graded" the available evidence of carcinogenicity include: acrylonitrile; atrazine; benzidine-based dyes; 1,3-butadiene, dichloromethane (methylene chloride); di (2-ethylhexyl) phthalate; glass wool insulation; MtBE [methyl tertiary butyl ether]; ochratoxin A; saccharin; sunlamps and sunbeds (use of); trichloroethylene; sulfamethazine; and others more inclusively mentioned in the text and tables. Further impeding or compromising public health, chemicals causing site-specific cancers in animals attendant with calculi/precipitate in the urinary bladder, goiter and thyroid gland, kidney and alpha-2mu globulin, peroxisome proliferation and liver tumors, and cell proliferation in general have led the IARC to discount these car- cinogenic effects. To stem this tide at the IARC, new leadership, with more objectivity and public health perspective, is needed.