Induction of O-deethylase activity as an index to exposure to coal-derived products and trace environmental pollutants

The metabolism of the synthetic substrate 7-ethoxyresorufin is a selective measure of the activity of cytochrome P-448 monooxygenase, the subset of cytochrome P-450-mediated enzymes preferentially induced by polycyclic aromatic hydrocarbons and related compounds. 7-Ethoxycoumarin metabolism, on the other hand, reflects total (nonselective) cytochrome P-450 monooxygenase activity. Either substrate yields a single, highly fluorescent product, amenable to direct, sensitive assay with the portable centrifugal analyzer. We used three assays with liver microsomes from C57/BL6 mice for the short-term bioassay of the dose-dependent effects of exposure to selected environmental toxins, including petroleums, polychlorinated biphenyls, and their oxidative degradation products.

Relative potency estimation for synthetic petroleum skin carcinogens

A procedure for quantitative analysis of skin carcinogenesis data, for the purpose of establishing carcinogenic potency, has been applied to observations obtained from C3H mice exposed continuously to synthetic and natural petroleums. The importance of total polynuclear aromatic (PNA) content to the skin carcinogenic activity of the crude materials was also examined. Of three synthetic petroleums evaluated, all were shown capable of inducing skin neoplasms within a two-year exposure period. Under comparable exposure conditions a composite sample of five natural petroleums was noncarcinogenic. Comparison of the distributions of times to initial skin neoplasm versus dose rate, for groups exposed to synthetic fossil liquids and the reference skin carcinogen, benzo(a)pyrene, provided estimates of relative carcinotenic potency for the synthetic petroleums ranging from 1/500 to 1/1400 the potency of benzo(a)pyrene. The carcinogenic activity of a chemically isolated PNA fraction versus the crude from which it was derived suggested that this fraction was responsible for the carcinogenic activity of these synthetic petroleums in mouse skin.

Conservative management of twisted testicular appendages

We planned non-operative treatment of a twisted intrascrotal appendage in 23 consecutive patients, ranging in age from 6 to 45 years, in whom the diagnosis could be made confidently. Only 3 patients have required subsequent removal of the infarcted appendage because of persistent or recurrent pain. The remaining patients became free of pain within a week. Prompt surgical exploration to exclude torsion of the spermatic cord remains necessary if scrotal swelling obscures the diagnosis. At operation for the latter indication 5 additional boys were found to have a twisted appendix testis during the study interval.

Interaction between benzo[a]pyrene and mouse skin in organ culture

An in vitro method for studying the interaction between tritiated benzo[a]pyrene ([3H]BP) and intact mouse skin was investigated. [3H]BP was applied to the epidermal surface of the skin floating on medium, and radioactivity in the medium was measured periodically. After 48-h incubation, about 45% of the radioactivity was in the medium; of this amount, about 80% accumulated during the first 24 h. Incubation temperature, metabolic inhibitors, and the amount of BP applied caused pronounced effects on accumulation; slight to moderate effects were noted for the type and volume of medium and vehicle used. Results of the temperature and inhibitor experiments indicated that accumulation of radioactivity depended on cell viability. About 80% of the radioactivity in the medium was water soluble, showing that biotransformation of BP by skin cells occurred. We are using the skin organ culture method to help understand the interaction of mammalian skin with hydrocarbon mixtures. A study of these interactions may lead to metabolic, cytotoxic, and macromolecular-binding profiles that characterize a carcinogenic mixture of hydrocarbons.

Binding of benzo [a]pyrene to epidermal DNA and RNA as detected by synchronous luminescence spectrometry at 77 K

The fluorescence associated with benzo[a]pyrene [BP] moieties covalently attached to the nucleic acid (DNA plus RNA) isolated from the epidermis of BP-treated mice was examined at 77 K in frozen aqueous solutions by use of a photon-counting fluorimeter operating in the synchronous scanning mode. The excitation and emission wavelengths were scanned simultaneously with the monochromators set 28 nm apart. This setting coincides with the difference in wavelength between the excitation and emission maxima for the fluorescence of bound BP. Currently the level of detection is in the order of 1 BP residue per 200,000 bases in 40 microgram of nucleic acid. This amount of nucleic acid can be isolated from the skin of a single mouse. The method described here is generally useful for detecting the binding to DNA of nonradioactive carcinogenic polynuclear aromatic which might occur following the topical application to animal skin in vivo of complex hydrocarbon mixtures such as synthetic fuels and crude oils.

Parent support groups for the families of mentally handicapped children

This paper describes a model of parent support group which has, as its aim, the provision of an effective clinical service to the handicapped child and his or her family. The aims and objectives of the group are outlined together with an evaluation of the effectiveness of the group after a period of 6 months. Conclusions are drawn as to the advantages of such a group and the importance of seeing the behaviour of the parent as an appropriate focus for intervention, is stressed.

Skin carcinogenicity of synthetic and natural petroleums

In a series of three separate experiments mice were exposed to various concentrations of fossil liquids obtained from coal, oil shale or natural petroleum. All materials were capable of inducing squamous cell carcinoma, but potency differed substantially. Skin carcinogenicity was markedly greater for both coal or oil shale liquids than for natural petroleums. None of the syncrudes approached the skin carcinogenicity of a pure reference carcinogen, benzo(a)pyrene (BP). It is unlikely that determination of the concentration of an active compound in material applied to the test animal will allow meaningful comparison among the diverse agents of interest to the synthetic fuels industry. To better establish the relationship between actual tissue dose and surface concentration the authors are investigating various in vitro and biochemical measures of hydrocarbon-skin interaction to determine which, if any, could serve as a more definitive measure of surface dose. Results, using BP as a marker carcinogenic hydocarbon, suggest that carcinogenic crudes inhibit both BP metabolism in skin organ culture and the interaction of BP adducts with epidermal DNA, in vivo.

Correlation of fluorescence intensity and carcinogenic potency of synthetic and natural petroleums in mouse skin

After standardized topical exposure of mouse skin to synthetic and natural petroleums, the penetration and persistence of the fluorescent components have been quantitated. Carcinogenicity of the same materials was determined by repeated skin application following by a period without treatment ot allow expression of malignantly transformed epidermal cells. No simple correlation was found for the materials between total specific fluorescence in either tissue or the test tube and their observed capacity to elicit skin necrosis or malignancy. The number of test materials was insufficient to allow generalization; however, the results do suggest that before fluorescence can be effectively employed as a tool for assessing potential occupational exposure to complex hydrocarbon mixtures, considerable refinement of the methodology will be required.

Leukocyte-platelet interactions in a murine model of Chediak-Higashi syndrome

Chediak-Higashi (CH) syndrome, a genetic disease affecting man and other animals, is partially characterized by defective platelets that lack serotonin and dense bodies and by impaired leukocyte function where chemotaxis, degranulation, and bacterial killing are decreased. The effects of normal platelets containing serotonin and of reagent serotonin on the subnormal microbicidal activity of CH leukocytes were evaluated. The peripheral blood leukocytes of the beige mouse, an animal model with CH syndrome, were used with Staphylococcus aureus as the bacterial challenge. Addition of as few as two normal platelets/leukocyte resulted in normal levels of microbicidal activity of CH leukocytes. A similar normalization of leukocyte function was seen when 1-100-micrometer serotonin was added to the incubation mixture. Based on this work and work of others, a plausible explanation for these observations is that normal platelets interact with CH leukocytes, releasing serotonin, which results in reversal of the CH leukocyte defect in bacterial killing.

Mutagenicity of dimethylnitrosamine and ethyl methanesulfonate as determined by the host-mediated CHO/HGPRT assay

Host-mediated assays have been developed to allow determination of the mutagenic potential of promutagens and procarcinogens which require metabolic activation to exert their effects on indicator organisms. We report here the development of the host-(mouse)-mediated CHO/HGPRT system using the procarcinogen dimethylnitrosamine (DMN) as a model agent. Using a 2--h treatment time, we observed a linear dose-response relationship up to 250 mg of DMN per kg body weight. At 100 and 500 mg/kg DMN, mutation induction increased with time up to at least 6 h. DMN was not mutagenic when tested in vitro. Athymic (nude) mice, their phenotypically normal littermates, or BALB/c mice of both sexes were found to be suitable as hosts. A time- and dose-dependency of induced mutation frequency by a direct-acting agent, ethyl methanesulfonate (EMS), was observed in both the in vitro and the host-mediated assays.

Radiation therapy for carcinoma of the prostate 5-year followup

Our original series of patients with prostatic carcinoma treated with irradiation as the initial modality has been updated. The over-all 5-year survival rate for patients with stage III carcinoma of the prostate was 55 per cent--26 per cent were alive with residual disease and have had post-irradiation hormone manipulation, while 29 per cent were alive without metastases at 5 years.

Ultrastructural and morphometric studies of platelets from cattle with the Chediak-Higashi syndrome

This study revealed that the lesions in platelets from cattle with the Chediak-Higashi syndrome (CHS) are not morphologically analogousto those present in the other granule-containing cells in cattle and other species with CHS. There was no evidence of enlargement of the lysosomal granules in bovine CHS platelets...

Serotonin deficiency and prolonged bleeding in beige mice

Beige mice have been observed to bleed excessively from small wounds. Platelets obtained from these mice were deficient in adenine nucleotides and serotonin and in vivo uptake of labeled serotonin was impaired. Heterozygotes of beige and C57BL/6 mice have adenine nucleotide and serotonin levels comparable to control and do not manifest a bleeding tendency, consistent with the recessive mode of inheritance of the beige mouse syndrome. Morphologic confirmation of the observed biochemical defects was obtained by the demonstration that serotonin storage organelles were not observed in electron photomicrographs of beige mouse platelets. The demonstration that small doses of serotonin were effective in reversing the bleeding tendency in beige mice suggested a causal role for defective storage and release of endogenous serotonin as the basis for the bleeding tendency, acting either independently or synergistically with impaired release of adenine nucleotides.

Development of fewer tumor colonies in lungs of athymic nude mice after intravenous injection of tumor cells

The formation of tumor colonies was compared in the lungs of athymic nude and normal littermate mice after an iv injection of transplantable syngeneic tumor cells. Each of 5 tumors tested formed fewer colonies in the lungs of nude recepients.

Lateral hermaphroditism in a C3H mouse

A spontaneous case of true lateral hermaphroditism was observed in one of approximately 1000 necropsies of 12-wk-old female C3Hf-Wg mice (a substrain of C3H/He). Both the right ovary and abdominal left testis were functional as evidenced by the presence of oocytes in graffian follicles and spermatocytes maturing on sertoli cells. Both gonads communicated, the ovary via an oviduct and normal right uterine horn and the testis via an epididymus and vas deferens, with a vagina which ended in a blind pouch and was filled with squamous debris.

Priapism in boys. Management with cavernosaphenous shunt

Two children with priapism are presented; one case was secondary to trauma and the other was idiopathic in nature. Both boys were effectively treated by bilateral corporosaphenous shunts. The mechanism of normal erection and the pathophysiology of priapism are discussed.