Effects of 3-methylcholanthrene on covalent binding and toxicity of 4-ipomeanol in inducible and non-inducible (B6D2) mice

The effects of 3-methylcholanthrene (MC) on the covalent binding and toxicity of 4-ipomeanol (1-(3-furyl)-4-hydroxypentanone, IPO) were studied in (C57BL/6N)(DBA/2N)F1 X DBA/2N backcross (B6D2)D2) mice previously segregated into relatively "inducible" or "non-inducible" groups based on zoxazolamine (2-amino-5-chlorobenzoxazole, ZOX) paralysis times following MC treatment. MC decreased the covalently bound IPO metabolite(s) both in the lungs and in the kidneys of "inducible" and "non-inducible" mice when compared to controls not pretreated with MC. On the other hand, concentrations of covalently bound IPO metabolite(s) in liver were increased in "inducible" mice and decreased in "non-inducible" mice by MC pretreatment when compared to non-pretreated heterogenous mice. Associated with MC pretreatment was a significant decrease in the acute lethality of IPO both in the "inducible" and in the "non-inducible" mice when compared to nonpretreated control animals (LD50: 213 +/- 2, 140 +/- 14 and 14 +/- 4 mg/kg, respectively). Hepatic necrosis occurred frequently in the "inducible" mice and occasionally in the "non-inducible" mice given large IPO doses near the respective LD50-values. Hepatic necrosis was never observed in non-pretreated mice receiving near lethal doses of IPO. These results support previous studies indicating that reactive IPO metabolites binding to extrahepatic tissues are formed in situ and do not reflect binding of blood-borne metabolites formed in the liver.

In vitro activity of rifamycins alone and in combination with other antibiotics against Chlamydia trachomatis

Rifamycins are highly active against Chlamydia trachomatis, but the possible development of resistance has been of concern. The ability of rifampin, rifamide, and DL473 to induce resistance in chlamydiae and the effect of combinations of antibiotics on chlamydiae were evaluated in tissue culture. When chlamydiae were exposed to stepwise increases in the concentration of rifampin or rifamide, resistance rapidly emerged. Stepwise resistance did not emerge after exposure to DL473, although organisms resistant to one rifamycin were resistant to all three. Single-step emergence of resistance to rifampin or DL473 was also demonstrated. However, these resistant organisms were difficult to maintain in tissue culture. Combinations of ampicillin, erythromycin, or a tetracycline with rifampin or DL473 were neither synergistic nor antagonistic against chlamydiae. However, subinhibitory amounts of erythromycin or oxytetracycline prevented the emergence of resistance to rifampin. Such combinations may prove useful in therapy for chlamydial infections.

Ceftazidime: a new approach in the treatment of moderate and severe infections

Ninety patients with serious infections, including 61 with septicaemia, pneumonia, peritonitis or meningitis, were treated with ceftazidime. Of these patients, 85.6% were clinically cured (73.3%) or improved (12.2%) by the antibiotic. In this study, 57.7% had infections due to Escherichia coli (24.7%), Klebsiella sp. (14.5%) and Pseudomonas sp. (18.5%). Two children with cystic fibrosis and Pseudomonas pneumonia and an adult with Legionella pneumonia responded well to ceftazidime treatment. Seventy patients had fever before treatment and most of them became apyrexial in less than 2 to 3 days. Ceftazidime was given either intramuscularly (42 patients) or intravenously (48 patients), in a dose of 1 g tds in 71 patients or 2 g tds in severe infections in 11 patients, or reduced to suit the renal function (7 patients) or in paediatric doses (2 children). Blood ceftazidime levels were measured in eight patients with normal renal function. The average level one hour post dosing was 45.2 mg/l and the average trough level was 8.1 mg/l. Six patients were suffering from variable degrees of renal insufficiency (serum creatinine 149 to 668 mmol/l). Their average blood level 1 h post-dosing was 68.8 mg/l. In a patient with meningitis, the CSF level was 2.4 mg/l 2 h after a 1 g dose. These levels are several times the ceftazidime MIC values for most clinical bacterial isolates. Ceftazidime is a valuable and safe alternative to aminoglycoside therapy.

Linn County Dental Health Center--a successful dental public health access program of treatment and prevention

The Linn County Dental Health Center is an example of what appears to be a highly successful dental society access program. A target population, the children of the poor and working poor in Linn County, have an opportunity to enter a system of continuous dental care for the prevention and control of dental disease. This example of dental society and community involvement, in the form of the ADA's guidelines for establishment and management of such access programs, may provide an impetus for action by other concerned individuals and dental societies.

Continuity of care in a county dental public health center

Examination of continuity of care, periodic preventive dental visits in a county dental public health center, was the focus of this study. The purpose of the study was to investigate: a) the relation between continuity of care and untreated dental caries, the unmet restorative dental treatment need, in low SES children in a county dental health center; and b) the association of certain family characteristics with continuity of care. If children failed to return for periodic appointments, were they being cared for in the private sector or was their oral health significantly poorer than the regular users? What specific family characteristics were associated with periodic preventive dental services? The investigation was a comparative study between two groups of financially eligible families, a continuous care group and noncontinuous care group. The information gained through the study was useful in devising strategies which would aid in the satisfaction of a primary objective of a dental public health treatment facility: to provide the opportunity for low SES children to have access to regular, periodic, preventive dental visits.

Partial galactose disorders in families with premature cataracts

Minor and major deficiencies of enzymes affecting galactose metabolism may be associated with cataracts of early onset. Results are presented for 10 such families with minor enzymatic disorders. Expression of the major disorders probably involves galactitol accumulation and osmotic lens damage but this mechanism is not obviously associated with minor disorders. The observed incidence of minor incomplete enzymatic disorders of galactose metabolism in families with an incidence of cataracts of early onset may be at least partly incidental.

Disulfide-linked oligomers of the major outer membrane protein of chlamydiae

The major outer membrane protein of chlamydial elementary bodies was identified in dimer, trimer, and other multimeric forms. These natural multimers were stabilized by disulfide-mediated cross-linking. Such cross-linking of outer membrane proteins may play an important role in the formation and evolution of chlamydial cell wall structure.

Comparison of reticulate and elementary body antigens in detection of antibodies against Chlamydia trachomatis by an enzyme-linked immunosorbent assay

Reticulate bodies from a type C and elementary bodies from a type L2 strain of Chlamydia trachomatis were isolated and used as antigens in an enzyme-linked immunosorbent assay (ELISA). Results obtained for human sera with these two antigens used in the ELISA were compared with each other and with results obtained for the same sera by the micro-immunofluorescence test. Negative control populations included cloistered nuns and children with respiratory infections. Populations at risk for chlamydial infection consisted of 42 men with nongonococcal urethritis attending a sexually transmitted diseases clinic and 42 college women who had contact with men with nongonococcal urethritis. ELISAs done with the two antigens were equivalent to each other and to the micro-immunofluorescence test in the ability to predict the presence or absence of infection. None of the tests had high predictive values for the men with urethritis. However, the negative predictive value of both the micro-immunofluorescence test and the elementary body ELISA was 0.92 for the college women. Such serological tests may be of value in screening selected populations for subclinical infections with C. trachomatis.

The use of Tween 20 as a blocking agent in the immunological detection of proteins transferred to nitrocellulose membranes

The determination of the immunoreactivity of protein antigens in complex mixtures has been greatly facilitated by combining their separation via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with electrophoretic transfer to nitrocellulose membrane (NCM), and probing of bound proteins with specific antisera. Methods using various buffers and blocking agents have been published, but no studies have been published which compare these methods with each other or with others of potential merit. We have performed such a comparative study using protein antigens from Chlamydia trachomatis and Neisseria gonorrhoeae. In addition, we describe a method that blocks unoccupied protein binding sites on NCM with the nonionic detergent Tween 20, rather than proteins. This system proved to be equivalent or superior to other methods evaluated in the detection of immunoreactive proteins, and permitted staining of the NCM for protein after immunological probing. Such staining allowed precise identification of immunoreactive proteins. In addition, individual stained proteins could be excised and assessed for bound antibody in an indirect radioimmunoassay.

Analysis of the human serological response to proteins of Chlamydia trachomatis

Sera from individuals with culture-proven genital infection with Chlamydia trachomatis were analyzed for the presence of antibodies to chlamydial proteins by an immunoelectrophoretic transfer method. Protein antigens from representative strains of the 15 known serotypes were resolved by gel electrophoresis and transferred to a nitrocellulose solid support before being probed with serum. Sera from infected patients reacted with many different proteins. Most of these sera reacted with a 60,000- and a 62,000-molecular-weight protein which were present in each of the C. trachomatis serotypes and clinical isolates analyzed. In contrast, reactions with the major outer membrane protein were frequently observed but were usually weak. Sera from control groups of children, cloistered nuns, and college women, who were presumed not to have had prior chlamydial infections, did not usually have antibodies against the 60,000- or 62,000-molecular-weight protein, but did react with the major outer membrane protein and a 29,000-molecular-weight protein. These observations may have implications for the development of serodiagnostic tests as well as the identification of candidate antigens for vaccine development.

Structure--mutagenicity relationships for chlorinated ethylenes: a model based on the stability of the metabolically derived epoxides

We have established an empirical structure-activity relationship for the mutagenicity of certain haloalkenes, based on the calculated stability of the corresponding epoxides. The overall form of the relationship can be understood in terms of a simple theoretical model wherein mutagenic activity results from a balance between DNA binding and detoxification by enzymes such as glutathione transferase and epoxide hydrolase. The activity patterns for two different sets of geometries are sufficiently close to support our theoretical model and to suggest that correlations of this type are relatively insensitive to small changes in molecular geometry. Finally, the mutagenic activity for nine other haloalkenes is predicted, based on the present relationships.

Correlation between serum antichlamydial antibodies and tubal factor as a cause of infertility

Although salpingitis frequently produces tubal damage and infertility, many women with tubal factor as a cause of their infertility do not have a clinical history of salpingitis. In order to investigate whether or not some such cases might be due to subclinical chlamydial infections, we measured antichlamydial antibodies in the serum of 172 women consecutively undergoing evaluation for infertility. Only 16 (9.3%) had a prior history of salpingitis. Sixty-one (35%) had antichlamydial antibodies (S+), and of these 75% had tubal factor as a sole or contributing cause of their infertility, versus 28% of the seronegative (S-) women (x2 - 34, P less than 0.001). There was no association between chlamydial seropositivity and any infertility factor other than tubal factor in multivariant analyses. Subclinical infections with Chlamydia trachomatitis may be a major cause of tubal infertility in the United States, and chlamydial serologic studies may be useful in identifying the subset of infertile women likely to have tubal factor.

Comparative evaluation of media for isolation of ureaplasma urealyticum and genital mycoplasma species

Two media systems were compared for isolation of Ureaplasma urealyticum and genital Mycoplasma sp. System 1 (S-1) consisted of arginine agar and an arginine biphasic medium for isolation of Mycoplasma sp. and urea agar and urea broth for isolation of U. urealyticum. System 2 (S-2) utilized Boston broth, which is a urea-containing broth, and A7 agar, both of which support the growth of both species. Urine samples, some freshly collected and some known-positive frozen samples, were used as inocula for the two media systems. With S-1, U. urealyticum was recovered in 68% of U. urealyticum-positive cultures: 58% were detected in urea broth, and 60% were identified on urea agar. When the S-2 system was used for culture of the same samples. U. urealyticum was recovered in 98% of the cultures, with 94% detected in Boston broth and 92% identified on A7 agar. Mycoplasma sp. was recovered in S-1 and S-2 in 97 and 100% of Mycoplasma sp.-positive cultures, respectively. The S-1 arginine broth gave positive results for 89% of the cultures, and the arginine agar was positive for 97% of the cultures. The S-2 Boston broth and A7 agar gave positive results for 92 and 97% of the cultures, respectively. For the isolation of U. urealyticum, colony counts were higher, growth was seen sooner, and colonies were larger when the S-2 media system was used. Overall, the cost per test of the S-2 system was less both in technologist time and in reagent costs.

Hyalinosis cutis et mucosae

Hyalinosis cutis et mucosae is an uncommon genetic disease characterized by accumulation of glycoproteinaceous material not only at mucocutaneous sites but also in salivary glands, central and peripheral nervous systems, eyes, nd other organs and tissues. The course of the disease is protracted, and it is not likely to regress, either spontaneously or with therapy. Although it does not usually result in decreased longevity, the disorder may produce considerable disfigurement and functional impairment. This article documents the case of a 5-year-old girl who presented with vocal weakness, misarticulations, and hoarseness; hypopigmented scarring of the arms and pubis; fibrotic thickenings of the oral and laryngeal mucosa; and serous otitis media. A tongue biopsy revealed diffuse hyaline deposits throughout the connective tissue and in a lamellar pattern about blood vessels. A diagnosis of hyalinosis cutis et mucosae was made.

Galactose intolerance and the risk of cataract

Cataracts may arise in association with various major and minor disorders restricting galactose metabolism, and the risk is broadly associated with the degree of galactose intolerance. A family is described in which a girl presented at the age of 7 3/4 years with cataracts, galactosuria, and partial deficiencies of the enzymes galactokinase and galactose-1-phosphate uridyl transferase. Galactose intolerance as determined by an oral test was impaired and fluctuated with variation in activity of the above galactose enzymes. Minor defects were also present in the parents and a maternal half-brother. The child has a compound disorder of galactose metabolism differing from those previously described. Assessment of galactose tolerance may be useful in the investigation of families with an incidence of cataract.

Protective role of endogenous pulmonary glutathione and other sulfhydryl compounds against lung damage by alkylating agents. Investigations with 4-ipomeanol in the rat

Because endogenous glutathione is known to participate in the detoxification of highly reactive, hepatotoxic drug metabolites, we studied the role of this substance in the pulmonary toxicity of 4-ipomeanol [1-(3-furyl)-4-hydroxypentanone] in rats. 4-Ipomeanol was an appropriate model for these studies since previous investigations have indicated that an alkylating metabolite, formed in situ, is responsible for selective lung damage by 4-ipomeanol. Toxic doses of 4-ipomeanol preferentially depleted rat lung glutathione. Pretreatment of animals with piperonyl butoxide, an inhibitor of the metabolic activation of 4-ipomeanol, prevented both the depletion of lung glutathione and the pulmonary toxicity of 4-ipomeanol. Prior depletion of lung glutathione by diethylmaleate increased both the pulmonary covalent binding and the toxicity of 4-ipomeanol, whereas administration of cysteine and cysteamine decreased both the covalent binding and the toxicity. These in vivo studies, in conjunction with previous in vitro studies which showed inhibitory effects of sulfhydryl compounds on the covalent binding of 4-ipomeanol, are consistent with the view that pulmonary glutathione plays a protective role against pulmonary alkylation and lung toxicity by 4-ipomeanol, probably by reacting with the toxic metabolite(s) to form nontoxic conjugate(s). Pulmonary glutathione may similarly provide protection against other electrophilic drugs or metabolites that can damage the lungs.

Effects of early environmental enrichment upon open-field behavior and timidity in the domestic chick

Early environmental enrichment was evaluated by its effect on the behavior of 7-day-old male and female domestic chicks in an open field or novel environment and in a hole-in-the-wall test of timidity. The chicks were housed in same-sex groups of 10. The bare environments contained wood litter, food, and water, whereas the enriched boxes also contained various objects. In the open field, immobility was lower while feeding, walking, jumping and vocalization were higher in the enriched birds than in those reared in the bare environment. Enrichment also decreased emergence latencies in the hole-in-the-wall box. The increased stimulation provided by environmental enrichment may decrease fearfulness in subsequent fear-inducing situations and may enhance the ability of animals to adapt to novelty.