Malignant rhabdoid tumor: a highly malignant childhood tumor with minimal karyotypic changes

Malignant rhabdoid tumors (MRT) are rare; thus very few cytogenetic studies of this type of tumor have been performed. We report the results of cytogenetic studies of 10 MRTs from various anatomic primary sites. Six cases had normal diploid karyotypes with no detectable rearrangements or aneuploidy except for occasional tetraploid cells. In 4 of these cases the tumor phenotype was verified by electron microscopic studies. In a seventh case only normal cells were identified in short-term culture, but a del(13)(q14) appeared after 4 months in culture. A soft tissue MRT contained a translocation, t(8;15)(q12;p11), and a liver MRT contained a del(3)(q21) or t(3;?)(q21;?). The single case of a primary brain MRT had monosomy 22 with deletion of part of the remaining chromosome 22. Our findings indicate that visible chromosomal rearrangements occur in fewer than half of MRTs. When combined with other reported series, our study indicates that monosomy 22 is a non-random chromosomal abnormality in primary MRT of the brain.

Diagnosis of adolescent hypertension on initial screening by the use of height age

The tremendous variability in growth and maturation during adolescence makes body mass a better determinant of blood pressure (BP) than chronologic age (CA). To evaluate whether two accepted indicators of body mass, height age (HA), and weight age (WA) could accurately predict hypertension on initial screening, 1426 healthy adolescents had their BP, height, and weight measured and Tanner stage assessed. The mean of three BP measurements were compared to eight published nomograms which correlate BP with height, weight, or CA. Patients with an initial elevated BP (greater than 95 percentile for height, weight or CA) were reevaluated to verify persistent hypertension. Eighty-seven (6.1%) initially appeared to be hypertensive with 0.84% persistently hypertensive. The diagnosis of hypertension varied considerably when the BP measurements were reevaluated based on HA or WA. Height age was the most sensitive (100%) and specific (62.6%) criteria for the diagnosis of hypertension and can be used for initial BP screening in this age group.

Effects of dose, age, inhibition of metabolism and elimination on the toxicokinetics of 2-butoxyethanol and its metabolites

Acute exposure to 2-butoxyethanol (BE) causes dose- and age-dependent hemolytic anemia in rats. Recently, we have shown that butoxyacetic acid (BAA) is the proximate hemolytic agent and that inhibition of alcohol or aldehyde dehydrogenases protected rats against BE-induced hemolytic anemia. In the present investigations, the kinetics of 14C-BE metabolism and clearance were studied in control adult (3-4 months old) and old (12-13 months old) male F344 rats and in adult male F344 rats treated with pyrazole, cyanamide or probenecid. Our results showed that the area under the curve (AUC), maximum plasma concentration (Cmax) and systemic clearance (Cls) of BE were dose-dependent. In contrast, there was no effect of dose on half-life (T1/2) or volume of distribution (Vd) of BE. These results also showed that there was no age effect on T1/2, Vd or Cls of BE. However, Cmax and AUC of BE increased as a function of age. Also, analysis of variance indicated no significant interactions (P less than or equal to .05) between dose and age in relation to BE kinetics. As expected, inhibition of BE metabolism by pretreatment of rats with pyrazole or cyanamide resulted in a significant increase in the T1/2 and AUC of BE, whereas it caused a significant decrease in the Cls. Furthermore, pyrazole had no effect, whereas cyanamide had decreased Vd of BE. Analysis of the toxicokinetic parameters of BAA revealed that T1/2, AUC and Cmax of BAA were directly related to the age of the rats and the dose of BE administered.(ABSTRACT TRUNCATED AT 250 WORDS)

Vaginal absorption of polyvinyl alcohol in Fischer 344 rats

Polyvinyl alcohol (PVA) is a polymer with a wide range of molecular weights and uses. Recently, low molecular weight formulations of PVA have been used as components of contraceptive products designed for intravaginal administration in human females. Previous studies in animals have determined that little or no absorption of PVA occurs from the gastrointestinal (GI) tract. However, there is some concern that PVA of lower molecular weights might be absorbed across membranes of the reproductive tract. Consequently, this work has investigated the absorption of low molecular weight PVA across biological membranes of the reproductive and GI tracts of Fischer 344 rats. Oral administration of ten consecutive daily doses of 14C PVA resulted in little apparent absorption of the dose from the GI tract. In contrast, intravaginal administration of 14C PVA resulted in increasing concentrations of PVA-derived radioactivity in major tissues following one, three or ten daily doses of the estimated human dose of 3 mg/kg. PVA-derived radioactivity was concentrated mainly in the liver, reaching a peak greater than 1750 ng equivalents/g tissue 24 hours following ten daily doses. Over 300 ng equivalents/g tissue were still present in the liver 30 days following the last dose.

The bleeding time may be longer in children than in adults

The bleeding time, the most frequently performed test reflecting in vivo platelet function, is the duration of blood flow from a standardized incision on the volar surface of the forearm. Normal values have been determined in adult subjects, but with the exception of neonates, data on the range of bleeding time values in pediatric patients are unavailable. Standard hematology textbooks imply that bleeding time values in children are similar to those of adults. We have reviewed our 9 years of experience with 137 children (mean age 6.5 years) who were referred for diagnostic evaluation of a bleeding disorder but whose history and physical examination were felt by us to be inconsistent with an abnormality of hemostasis. Bleeding time values in these individuals (mean 6.0 min, 95th percentile 9.0 min) were compared with those of 85 normal adult volunteers (mean 4.4 min, 95th percentile 6.5 min). The Simplate-I disposable device and vertical (perpendicular to elbow crease) incision direction were used in both groups. This difference between the pediatric and adult bleeding time values is statistically significant (p less than 0.0001). Neither age nor sex had a significant effect on the pediatric bleeding time measurements. We conclude that the bleeding time, when performed as described, is longer in children than in adults and that pediatric standards for bleeding time should be used in order to avoid a spurious diagnosis of a primary hemostatic disorder in some normal children.

Complementary DNA for the folate binding protein correctly predicts anchoring to the membrane by glycosyl-phosphatidylinositol

Membrane bound and soluble forms of a high-affinity folate binding protein have been found in kidney, placenta, serum, milk, and in several cell lines. The two forms have similar binding characteristics for folates, are immunologically cross-reactive and based upon limited amino acid sequence data, are nearly identical. Based upon pulse-chase experiments, a precursor-product relationship has been suggested. The membrane form has been shown to mediate the transport of folate in cells grown in physiological concentrations of folate. A function for the soluble form has not yet been identified. We constructed a cDNA library from a human carcinoma cell line, Caco-2, which expresses the membrane form abundantly. The library was screened and a near full-length cDNA for the folate binder was isolated. Transfection of COS cells with the cDNA inserted in an expression vector resulted in marked overexpression of a membrane-associated folate binder as assessed by direct binding of radiolabeled folate and by indirect immunofluorescence. The deduced amino acid sequence is not consistent with a typical membrane spanning domain but rather with a signal for anchoring via a glycosyl-phosphatidylinositol linkage. Release of the binder with a phosphatidylinositol-specific phospholipase C strongly supports this hypothesis.

Pediatricians' use of chaperones when performing gynecologic examinations on adolescent females

This study assesses the influence of the interest and skill in adolescent health care on a pediatrician's use of a chaperone during the pelvic examination. A national sample of 558 pediatricians selected at random and 384 members of the American Academy of Pediatrics' Section on Adolescent Health (SAH) completed questionnaires assessing their perceived skills in and practice of adolescent medicine. Some 90.4% of the non-SAH males and 31.0% non-SAH females always used a chaperone compared to 69.4% of SAH males and 12.5% of SAH females (p less than or equal to 0.05). The actual frequency of chaperone use was less among SAH members than non-SAH pediatricians (p less than or equal to 0.013) and less among females in both groups (p less than or equal to 0.0001). Among male physicians, the variables found to have the strongest association with a less frequent use of chaperones included the frequency that oral contraceptives were prescribed, perceived skill in providing contraceptive counseling, percent of adolescents in the pediatrician's practice, and the frequency with which confidential services were provided. These correlations were stronger among SAH members than non-SAH pediatricians. Among female SAH members, not using a chaperone was associated with a higher perceived skill in managing sexually transmitted diseases, the frequency with which they performed pelvic examinations, and the percent of adolescents in their practice. Among non-SAH female physicians, the perceived skill to perform a pelvic examination and provide contraceptive counseling were associated with increased chaperone use. These data suggest that many factors other than gender and medicolegal influences are associated with the physician's decision concerning the use of a chaperone.

Comparative metabolism and disposition of ethyl carbamate (urethane) in male Fischer 344 rats and male B6C3F1 mice

The metabolism, disposition, and excretion of ethyl carbamate (EC) was investigated following oral or iv administration of a wide range of doses to male rats and mice. At a low dose, 4.75 mg/kg, administered iv, approximately 98% was exhaled as CO2 within 8 or 12 hr by mice or rats, respectively. However, as the dose increased, the percentage of dose eliminated as CO2 decreased in a dose-dependent manner which was much more pronounced in rats than mice. At all doses studied, mice eliminated EC as CO2 (as % dose) more rapidly than rats. Evidence of saturation of metabolism and elimination was observed at doses greater than 4.75 mg/kg in rats and greater than 47.5 mg/kg in mice. Following iv administration of 47.5 or 475 mg/kg, EC was initially evenly distributed in all tissues of each species except fat. After the initial time point (15 min), rat tissues contained higher concentrations of 14C compared to tissues of mice receiving the same dose. The disappearance of 14C from blood and various tissues followed monoexponential kinetics with rates dependent upon the species and the dose but independent of the tissue. Following oral administration, EC was completely absorbed from the gastrointestinal tracts of rats and mice at all doses studied. Approximately 5, 0.7, and 1% of the doses were excreted in urine, in feces, and as volatile organics, respectively. EC was neither an inducer nor an inhibitor of its own metabolism to CO2 following daily treatment of rats with oral doses of 47.5 mg/kg for 9 days. Only the parent compound was present in blood, lungs, skin, liver, kidney, muscle, and bile of treated rats. The urinary metabolic profile of EC was not affected by the route of administration in either species; however, in the rat but not in the mouse it was influenced by dose. Pretreatment of rats with piperonyl butoxide or SKF 525A (cytochrome P-450 inhibitors) or tri-o-cresyl phosphate (TOCP) or paraoxon (carboxylesterase inhibitors) or methyl carbamate (competitive substrate) did not greatly alter the metabolism of EC to CO2. The in vitro metabolism of EC to CO2 was not highly localized in any particular tissue or subcellular fraction of liver and was not affected by NADPH, GSH, NADH, or combinations of these cofactors. This work indicates that a number of studies of EC carcinogenicity have used doses that exceed the capacity of rats and mice to metabolize this chemical in a linear fashion.

Sexual behavior and contraceptive risk taking among sexually active adolescent females

Drawing on DeLamater's conceptual model of premarital contraceptive activity, this study assessed the relationships between various social, developmental, and behavioral variables and contraceptive risk taking by sexually active adolescent females. The hypotheses were tested on a national random sample of unmarried sexually active adolescent females (n = 1512) ages 15-20 years from Cycle III of the National Survey of Family Growth. The number of years the subjects had been sexually active was the strongest predictor of their frequency of sexual intercourse, followed by their frequency of attendance at religious services. The inverse relationship between religious attendance and coital frequency was much stronger among whites than blacks. When the influence of these variables on contraceptive risk taking was assessed, coital frequency explained 7.2% of the variation in contraceptive risk taking, with the number of years the adolescent had been dating explaining a small amount of additional variation. Our data support not only the first stage of DeLamater's conceptual model of premarital contraceptive activity, but also aspects of Jessor's more general theory of adolescent risk taking and problem behavior.

Dentists' professional satisfaction with adolescent dentistry and its association with adolescent dental health behavior

This study examines dentists' perceptions of behaviors felt to interfere with providing adequate dental care to adolescents. We analyzed gender differences, and whether the dentists' perceptions of adolescent patients were associated with their professional satisfaction. A stratified random sample of 227 graduates (males = 180, females = 47) from a Southern dental school were asked to complete a questionnaire assessing professional satisfaction. Based on Kruskall-Wallis analysis of variance tests, female dentists expressed generally higher levels of satisfaction than males with adolescent dentistry, diagnosis and treatment planning, patient education, preventive procedures, and the adolescent dentistry curricula during dental school. Male dentists felt that the male adolescents' failure to keep appointments, communication problems, seeking dental care only in emergency situations, and resentment of authority interfered more with their providing adequate dental care than did female dentists. Male dentists also felt that the female patients' menstrual period, communication problems, low tolerance of pain, seeking dental care only in emergency situations, and resentment toward authority were more significant problems than did the female dentists. Communication problems with both male and female adolescents were more strongly correlated with the dentists' satisfaction with adolescent dentistry than any other variable.

Agonist and antagonist activities of arylpiperazines at human platelet serotonin2 receptors

A series of arylpiperazines was examined for structure-function relationships at the human platelet serotonin (5-HT) receptor. Amplification of ADP-induced aggregation was used to measure 5-HT receptor activation. The platelet serotonergic agonists 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI), 5-HT and 5-methoxytryptamine (5-MeOT) and the antagonist ketanserin were used for comparison of potency and amplitude of response. All arylpiperazines, including the parent compound phenylpiperazine (PP) showed antagonist activity. The monosubstituted phenylpiperazines acted only as antagonists, and electron-withdrawing substituents markedly enhanced activity. Modification of PP by addition of another phenyl ring or benz-fusion also enhanced antagonist activity. Benz-fusion at the b face of PP (1-NP) yielded greater antagonist potency than benz-fusion at the c face (2-NP). The latter modification, however, also conferred a variable agonist activity with a very weak response. In contrast, the heteroaromatic piperazines consistently demonstrated concentration dependent mixed antagonist-agonist activity. These compounds were weak agonists compared with 5-HT, 5-MeOT and DOI, although the amplitude of the quipazine response was similar to DOI. This study demonstrates that the arylpiperazines, which are variably selective for the multiple brain 5-HT receptors, are all antagonists on the platelet 5-HT receptor. The antagonist activity is markedly increased by ring monosubstitution or aryl modification. Compared with the monosubstituted analogues, antagonist activity is decreased by heteroaromatic modification or by the addition of an N-aminophenethyl group to the 4-position nitrogen. Weak agonist activity can be conferred by heteroaromatic modification.

Analysis of contraceptive behavior of sexually active female adolescents in the United States

Drawing on a theoretical model of adolescent contraceptive behavior, we examined the relationships between various social and behavioral variables and contraceptive use by sexually active female adolescents. Hypotheses were tested with the use of a national random sample of sexually active female adolescents (n = 1426), aged 15 to 20 years, from Cycle III of the National Survey of Family Growth. The data were analyzed with Pearson correlation coefficients and multiple regression analysis. Noncompliance with the initial birth control method was the strongest predictor of the adolescents' contraceptive behavior at the time of the interview. Not acquiring birth control at the initial family planning visit and the frequency of family planning visits during the previous 12 months were the second and third best predictors of subjects' contraceptive use. Coital frequency and the length of time between first coitus and the initiation of birth control each explained a small amount of additional variation in the regression model. When combined, these five variables explained 40% of the variation in the contraceptive behavior of this representative sample of sexually active female adolescents. The findings could be useful for clinicians in providing more effective birth control counseling to adolescent patients.

Recommended changes in pediatric education: the impact on pediatrician involvement in health care delivery to adolescents

In an attempt to examine the extent of implementation of the recommendations issued by the Task Force on Pediatric Education for increased emphasis on adolescent medicine during residency training, pediatricians' perceptions of their skills and abilities to provide health care to adolescents were evaluated. A sample of 558 pediatricians selected at random and 385 members of the American Academy of Pediatrics' Section on Adolescent Health (SAH) completed a 41-item questionnaire. The physicians' perceived levels of skill in ten areas were analyzed while simultaneously assessing the impact of SAH membership, year of graduation from medical school, gender, and percentage of practice time devoted to adolescents on each issue. SAH members, as expected, ranked their levels of skill significantly higher than did the other pediatricians in all areas surveyed. A significant percentage of the SAH pediatricians, however, indicated that their skills were acquired through postresidency fellowship training. There was an increasing trend among all pediatricians in their perceived levels of skill to deliver health care to adolescents during the past several decades, but there has been no appreciable increase in such perceived skill levels since the task force issued its recommendations. In fact, pediatricians graduating from medical school in the decade prior to 1976 who are not SAH members ranked their skills higher than did non-SAH pediatricians who graduated in the past 10 years. These data lead to the conclusion that the recommendations of the Task Force on Pediatric Education have not been adequately implemented.

Adolescent females' readiness to participate in sports. Sex and race differences in the preparticipation athletic examination

With the increasing number of adolescent females participating in organized athletics, there has been concern over their susceptibility to injury during participation. This study assesses whether females differ from males in the severity and frequency of abnormalities on the preparticipation athletic examination (PAE). Standardized PAEs were performed on 1259 high school athletes. Females were found to have significantly less orthopedic problems than males on both the health history and the physical examination. Females were found to have a lower percentage of abnormalities of the hips, knees, and ankles than males. Black males had a significantly higher rate of hip abnormalities than white males, and black females had a higher rate of knee abnormalities than white females. A significantly higher percentage of males than females were referred for further evaluation prior to athletic participation. Although our adolescent females had fewer physical problems on the PAE that might add to their risk of having an athletic injury, the types of problems that were found in our females suggest that they should participate in more aerobic and strength training sessions prior to the sports season.

Analysis of glutathione conjugates and related compounds by thermospray mass spectrometry

A series of 17 cysteine, N-acetyl cysteine, glutathione, and N-trifluoroacetyl glutathione conjugates have been prepared, and their thermospray (TSP) spectra have been recorded in the positive and negative ion modes. The compounds undergo extensive fragmentation, which primarily occurs at the carbon-sulfur bonds. For most of the compounds, positive ion TSP is more sensitive than negative ion thermospray. Probably due to the thermal lability of these adducts, the quality of the spectra obtained are dependent on source conditions, requiring fine control of the vaporization/desolvation process.

Methyl carbamate. Species-dependent variations in metabolism and clearance in rats and mice

Studies of the chronic toxicity and carcinogenicity of methyl carbamate (MC) in F344 rats and B6C3F1 mice indicate that this compound is more toxic to rats than mice. MC was also a carcinogen for rats but not a carcinogen for mice even when administered at a higher dose. The present study of the comparative metabolism and disposition of MC in these two species was conducted to determine possible sources of these varying responses. Results of this study indicate that, although the initial distribution of MC in the two species is similar, the mouse metabolizes and clears MC much more rapidly than does the rat. In the mouse, clearance was primarily by metabolism to CO2 and elimination in exhaled air, which accounted for approximately 70% of the dose in 48 hr. On the other hand, the rat eliminated approximately 18% of the dose as CO2 in 48 hr and a similar amount in urine. The parent compound accounted for approximately 90% of the material excreted in urine of both rats and mice. Only the parent compound was detected in tissues of either species. Less than 4% of the dose was excreted in feces of either species. The lesser ability of the rat to metabolize and eliminate MC as CO2 results in bioaccumulation of this compound on repeat exposure. Therefore, bioaccumulation of MC by the rat on chronic exposure probably results in both greater total exposure and higher peak exposure of most rat tissues vs. those of mice and may thus account for the greater toxicity and possibly carcinogenicity of MC to rats.

Metabolism and disposition of n-butyl acrylate in male Fischer rats

Butyl acrylate (BA) is one of the major monomers used in the manufacture of polymers and resins. Because little is known regarding its metabolic fate in animals, it was of interest to study the metabolism and disposition of BA in the rat. After oral administration, butyl [2,3-14C]acrylate was rapidly absorbed and metabolized. The acrylate moiety was metabolized primarily to CO2, accounting for elimination of up to 75% of the administered radiolabel. Elimination in urine and feces accounted for approximately 10 and 2% of the dose, respectively. Initial clearance of radioactivity from the tissues was very rapid and then decreased to a negligible rate 2 hr after iv administration. Total radioactivity in the major tissues was relatively constant from 2 to 24 hr. The majority of the radioactivity in the blood at 24 hr was found to be covalently bound to the protein fraction of the red blood cell membranes. There was some evidence of a first-pass effect when BA was administered by gavage because iv administration resulted in less metabolism to CO2 and quantitative differences in urinary metabolites. The two major metabolites in urine were identified as N-acetyl-S-(2-carboxyethyl)cysteine and N-acetyl-S-(2-carboxyethyl)cysteine-S-oxide. Results of this study indicated that the major portion of a BA dose was hydrolyzed to acrylic acid, which was further metabolized to compounds available for oxidative metabolism. Radiolabeled carbons from the BA molecule were excreted as CO2 or incorporated in trace amounts into lipids, proteins, and other products of de novo synthesis. A smaller portion of the BA dose was conjugated with endogenous glutathione.(ABSTRACT TRUNCATED AT 250 WORDS)

Metabolism and disposition of ethylene glycol monobutyl ether (2-butoxyethanol) in rats

Ethylene glycol monobutyl ether (2-butoxyethanol, BE) is a major industrial chemical with multiple and diverse uses that may result in significant risk of human exposure and environmental contamination. The current studies were undertaken to investigate the metabolism and disposition of this chemical in male F344 rats. Data presented in this report showed that BE is rapidly absorbed after gavage administration, metabolized, and eliminated. Tissue distribution of BE revealed that BE is distributed to all tissues with the highest levels (determined 48 hr after dosing) detected in the forestomach followed by the liver, kidney, spleen, and the glandular stomach. However, the increase in the tissue concentration in rats treated with 500 mg/kg (as compared to that in rats treated with 125 mg/kg BE) was not proportional to the increase in BE dose. The major route of BE elimination was in the urine, followed by 14CO2 exhalation. The portion of the BE dose eliminated in urine or as 14CO2 was significantly higher in rats treated with 125 mg/kg than in the rats treated with 500 mg/kg. This may indicate that saturation of BE-metabolizing enzymes occurs at the high dose. A small portion (8%) of the administered dose (500 mg/kg) was excreted in the bile in 8 hr after dosing. Qualitative and quantitative HPLC analysis of the urinary and biliary metabolites of BE revealed that the major urinary metabolite, butoxyacetic acid (BAA), accounted for more than 75% of the radioactivity excreted in the urine. The second major metabolite in urine was the glucuronide conjugate of BE (BEG).(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption, distribution, metabolism, and excretion of 1,2-dihydro-2,2,4-trimethylquinoline in the male F344 rat

1,2-Dihydro-2,2,4-trimethylquinoline (TMQ), an antioxidant used in the rubber industry, was readily absorbed from the gastrointestinal tract of the male Fischer 344/N rat and rapidly distributed throughout the body tissues. Absorption, distribution, metabolism, and excretion were not significantly affected by dose in the range 11.5-1150 mumol/kg. Following iv administration, the greatest amounts of TMQ-derived radioactivity were present in the high volume tissues including muscle, adipose, skin, liver, and blood. TMQ had no particular affinity for any tissue. TMQ-derived radioactivity was excreted primarily in urine (60-70%) and feces (20-30%) within 3 days after administration. Greater than 99% of the TMQ dose excreted in urine and feces was in the form of metabolites. Urine contained two major and ten minor metabolites while feces contained two major and four minor metabolites. The two major TMQ metabolites in urine were identified by NMR and mass spectroscopy as the O-sulfate conjugate of 1,2-dihydro-6-hydroxy-2,2,4-trimethylquinoline and the monosulfate conjugate of 1,2-dihydro-1,6-dihydroxy-2,2,4-trimethylquinoline. In vitro studies with liver subcellular fractions suggest that most of the metabolites present in urine, feces, and bile are the products of mixed function oxidase activity and conjugates of these metabolites. Multiple exposure of rats to high TMQ doses (1150 mumol/kg) resulted in some bioaccumulation of TMQ-derived radioactivity in all tissues examined, but these residues did not persist when dosing was discontinued.

Absorption and metabolism of 5-(4-nitrophenyl)-2,4-pentadienal (Spydust)

5-(4-Nitrophenyl)-2,4-pentadienal (NPPD) was recently alleged to have been used as a tracking agent to monitor the activities of U.S. citizens in the Soviet Union. In order to better assess human risk from possible exposure to this compound the absorption and metabolism of [14C]NPPD has been investigated in male F344 rats. These studies have revealed that NPPD was readily and quantitatively absorbed from the gastrointestinal tract, distributed throughout the tissues, metabolized, and rapidly excreted primarily in urine. NPPD was sparingly absorbed following dermal administration of 0.01, 0.1, and 1.0 mg/cm2. The amount absorbed increased as the dose increased but the percentage of the dose absorbed decreased as the dose increased, e.g., 50% (5 of 10 micrograms applied) of the low dose was absorbed but only 5% (50 of 100 micrograms applied) of the high dose was absorbed. The material absorbed after dermal administration was rapidly excreted and the distribution and metabolism of the dermally administered compound was no different from oral administration. A total of five metabolites, 4-nitrocinnamic acid, 4-acetamidobenzoic acid, 4-nitrohippuric acid, 4-acetamidocinnamic acid, and 4-nitrobenzoic acid, were identified by cochromatography with authentic standards and comparison of UV spectra. These metabolites are formed by oxidative metabolism of the pentadienal side chain, reduction of the nitro group, and/or conjugation of the resulting amino group with acetate or carboxylic acid with glycine.

Isolation and characterization of two types of MDCK epithelial cell clones based on glycosphingolipid pattern

The Madin-Darby canine kidney (MDCK) epithelial cell line was shown previously to be heterogeneous with marked differences reported between low-passage (strain I) and high-passage (strain II) cultures (Richardson, J.C.W., Scalera, V. and Simmons, N.L. (1981) Biochim. Biophys. Acta 673, 26-36). This report describes major differences in the glycolipids of the two subpopulations of cells that comprise strain I and strain II cultures. The majority of strain II cells were strongly positive for the Forssman glycolipid antigen, while strain I cells were Forssman-deficient. Upon finding that strain I cells were contaminated with mycoplasma, we rescued Forssman-deficient cells from strain II using an anti-Forssman plus complement lysis procedure. Clones of surviving cells consisted of two distinct cell types. The first were Forssman-deficient, non-ciliated, spindle-shaped cells which generated negative (apical to basolateral) transepithelial potential differences. Clones of the second type were strongly Forssman-positive, ciliated, and formed island-shaped clusters of cuboidal cells. These latter clones generated positive potential differences and grew more slowly than the spindle-shaped clones. Spindle cells were enriched in fucolipids, while cuboidal cells contained higher levels of sulfated glycolipids. These two types of clones should provide excellent model systems in which to study the processing and polarity of glycolipids in epithelial cells.

Driving safety and adolescent behavior

Accidents, and mainly automotive accidents, are currently the leading cause of mortality and morbidity among young people. Understanding and addressing the issue of automotive accident prevention requires an awareness of the multiple psychodynamic, familial, and societal influences that affect the development and behavior of adolescents. Risk-taking behavior is the product of complex personal and environmental factors. As pediatricians, we have the obligation and the opportunity to improve the safety of our youth who drive and ride. This opportunity is available to us not only in our roles as counselors to youth and families, but also as we serve as role models, educators, and agents for change within our communities.

Immunoassay of tryptase from human mast cells

A sandwich ELISA was developed for the measurement of tryptase. The assay utilizes the mouse monoclonal anti-tryptase antibody, termed G5 (IgG2b kappa) in the solid phase and monospecific goat IgG anti-tryptase antibody together with tryptase in the fluid phase. The immunoassay will quantify 0.1 ng-5.6 ng of tryptase per 100 microliters of sample solution to within 0.1 ng. Intra-assay coefficients of variation were determined at 0.3 ng, 1.0 ng and 3.0 ng of tryptase per assay, respectively, to be 19%, 7% and 4% with buffer and 10%, 4%, and 4% in the presence of 20% plasma. Inter-assay coefficients of variation at the same respective levels of tryptase were 22%, 18% and 15% with buffer and 18%, 11% and 14% with 20% plasma. Net absorbance values obtained with a standard amount of tryptase in buffer alone and up to 50% (v/v) normal human citrate-treated plasma were within 10% of one another, indicating nearly complete detection of tryptase added to plasma. This represents the first sensitive immunoassay for a preformed mediator specific for human mast cells.

Cerebral venous sinus thrombosis: report of a case and review of the literature

Cerebral venous sinus thrombosis is a condition that is well documented as a complication of the latter stages of pregnancy and with an even greater incidence during the puerperium. More recently this entity had been associated with the use of oral contraceptives. A case is presented of a 15-year-old girl with this condition, in whom the occurrence as well as the resolution of a superior sagittal sinus thrombosis was demonstrated with serial computed tomography (CT) scans and radionuclide studies. The discussion of this case, coupled with a review of the literature, describes the clinical presentation, explores the possible etiology, offers a noninvasive technique for confirming the diagnosis, and presents the medical management of this condition. It is postulated that cerebral venous sinus thrombosis occurs with a greater frequency than is currently recognized. Health professionals involved with monitoring the health care of adolescents during pregnancy and in the puerperium should be aware of this potential complications. In addition, association of this condition with oral contraceptive use should be recognized.

Health needs of adolescents in the military services

The decade of the 1970's has seen the integration of educational concepts concerning adolescent medicine into pediatric residency training programs within the military medical centers. A nucleus of professionals with this specialized training has been developed, and is currently providing health care to eligible adolescents residing in close proximity to these medical centers. The goal of the next decade is to expand these services and make them available to all dependents of active duty and retired military personnel around the world. Perhaps then, with continued growth and development, attention could be directed toward further expansion of these services to include the young active duty military personnel.

Antimalarials. 11. 2-Vinylogs of substituted 2-aryl-4-quinoline amino alcohols

3-(P-Chlorobenzylidene)-5, 7-dimethyl-2, 3-dihydro-1H-cyclopenta[b]quinoline-9-(di-n-butylaminomethyl)methanol and 2-[beta-(p-chlorostyryl)]-6, 8-dimethylquinoline-4-(di-n-butylaminomethyl)methanol were synthesized from 6, -8-dimethyl-4-hydroxycarbostyril by 3, 3-dichlorination, dimethoxylation th the 3-ketal, basic hydrolysis to the glyoxal acetal, Pfitzinger condensation with cylopentanone or acetone to the 2, 3-trimethylene or 2-methylquinoline, condensation with p-ClPhCHO at the 2-methylene or 2-methyl group, hydrolysis to the 4-quinaldehyde, methylenation to the epoxide, and condensation with Bu2NH. Both were curative against P. berghei in mice. The first was the more effective: active at 10 mg/kg, completely curative at 40 mg/kg, and only mildly phototoxic in animals.

Antimalarials. 10. Substituted 3-halo- and 3-methoxy-2-aryl-4-quinoline(di-n-butylaminomethyl)methanols

Four 2-aryl-4-quinoline(di-n-butylaminomethyl)methanols with Br, Cl, F, or OMe in position 3 were synthesized by modifications of standard reactions. The antimalarial activity decreased with increased size of the 3-substituent. The 3-F-4',6,8-Cl3 compound was the most active (at 2.5 mg/kg) and was completely curative at 80 mg/kg against P. berghei in mice.