Percutaneous absorption of N,N-dimethylformamide in humans

Summary Skin penetration fo N,N-dimethylformamide (DMF) liquid or vapour was studied in volunteers. Exposure to liquid DMF was performed in two ways: in a dipping experiment, one hand was dipped up to the wrist in DMF for 2–20 min, while in a patch experiment, 2 mmol DMF was applied to the skin and allowed to be absorbed completely. The period of exposure to DMF vapour (50 mg · m^–3) was 4 h. The DMF metabolites N-hydroxymethyl-N-methylformamide (MF), N-hydroxymethylformamide (F), and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) were monitored in the urine. Liquid DMF was absorbed through the skin at a rate of 9.4 mg · cm^–2 · h^–1. Percutaneous absorption of DMF vapour depended strongly on ambient temperature and humidity and accounted for 13%–36% of totally excreted MF. The results suggest that skin absorption of liquid DMF is likely to contribute to occupational exposure substantially more than penetration of DMF vapour. The yield of metabolites after transdermal DMF absorption was only half of that seen after pulmonary absorption. Elimination of MF and F but not that of AMCC was delayed, which supports the contention that AMCC should be used instead of MF as the most suitable biomarker of DMF in cases where percutaneous intake can occur.     

Susceptibility of clinical isolates of campylobacter pylori to 24 antimicrobial and anti-ulcer agents

Forty-nine isolates of Campylobacter pylori were tested for their susceptibility to twenty antibiotics and four anti-ulcer agents by an agar dilution technique. Penicillin and amoxycillin were the most active drugs (MIC₉₀, 0.06 /ml); erythromycin, cefazolin, minocycline, ciprofloxacin, ofloxacin and gentamicin were sligthtly less active (MIC₉₀, 1 g/ml). Moderate activity was found for doxycyclin, rifampin, nitrofurantoin, norfloxacin, pefloxacin, enoxacin, paromomycin, metronidazole and tinidazole. All strains were resistant to trimethoprim (MIC > 512 g/ml). Nalidixic acid (MIC₉₀, > 256 g/ml) and colistin (MIC₉₀, > 64 gg/m1) had little to no activity. Of four anti-ulcer drugs, only bismuth subcitrate showed activity (MIC₉₀, 64 g./ml).Strains resistant to all 4-quinolones were found in patients who had previously received ofloxacin as part of a clinical trial aimed at eradication of C. pylori. These isolates remained susceptible to amoxycillin, tetracyclines and to other classes of antibiotics.Corresponding author.     

Number-Between g-Type Statistical Quality Control Charts for Monitoring Adverse Events

Alternate Shewhart-type statistical control charts, called g and h charts, are developed and evaluated for monitoring the number of cases between hospital-acquired infections and other adverse events, such as heart surgery complications, catheter-related infections, surgical site infections, contaminated needle sticks, and other iatrically induced outcomes. These new charts, based on inverse sampling from geometric and negative binomial distributions, are simple to use and can exhibit significantly greater detection power over conventional binomial-based approaches, particularly for infrequent events and low defect rates. A companion article illustrates several interesting properties of these charts and design modifications that significantly can improve their statistical properties, operating characteristics, and sensitivity.     

Absorption,metabolism and elimination of N,N-dimethylformamide in humans

Summary Excretion of N,N-dimethylformamide (DMF) and DMF metabolites N-hydroxymethyl-N-methylformamide (MF), N-hydroxymethyl-formamide (F) and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC) has been monitored in the urine of volunteers during and after their 8-h exposure to DMF vapour at a concentration of 10, 30 and 60 mg · m^–3. The pulmonary ventilation in these experiments was typically about 101 · min^–1 and the retention in the respiratory tract was 90%. After exposure to 30 mg DMF · m^–3, the yield of compound determined in the urine represented 0.3% (DMF), 22.3% (MF), 13.2% (F) and 13.4% (AMCC) of the dose absorbed via the respiratory tract. The excretion curves of the particular compounds attained their maximum 6–8h (DMF), 6–8h (MF), 8–14h (F) and 24–34h (AMCC) after the start of the exposure. The half-times of excretion were approximately 2, 4, 7 and 23 h respectively. In contrast to slow elimination of AMCC after exposure to DMF, AMCC was eliminated rapidly after AMCC intake. This discrepancy could be explained by rate-limiting reversible protein binding of a reactive metabolic intermediate of DMF, possibly methylisocyanate.     

Identification of cis- and trans-verbenol in human urine after occupational exposure to terpenes

Summary Urine from sawmill workers exposed to -pinene, -pinene and -3-carene was collected and hydrolyzed with -glucuronidase at pH 5.0 for 24h at 37°C. After hydrolysis the urine was cleaned on a SEP-PAK C₁₈ cartridge. The cartridge was eluted with n-heptane. The eluate was injected onto a gas chromatograph equipped with a 25-m (0.32-mm ID) SP-1000 capillary column. The major peak in the chromatogram was identified by GC-MS as trans-verbenol by electron impact at 70 eV. cis-Verbenol was also identified. These metabolites could not be detected in non-hydrolyzed urine from the exposed workers or in hydrolyzed urine from an unexposed individual. The recoveries of the verbenols from hydrolyzed urine were in the range of 85 to 94% and the metabolites were stable both in urine and in n-heptane after sample cleaning at –20°C for at least 12 weeks. We suggest that these metabolites are formed from -pinene by hydroxylation.     

In vitro susceptibility of mycelial and yeast forms of Penicillium marneffei to amphotericin B,fluconazole, 5-fluorocytosine and itraconazole

The mycelial (25°C) and yeast-like (37°C) forms of Penicillium marneffei clinical and type strains were investigated for their in vitro susceptibility to amphotericin B (AmB), 5-fluorocytosine (5-FC), fluconazole (FLU) and itraconazole (ITZ), using Bacto antibiotic medium 3, yeast-nitrogen, Sabouraud's dextrose (pH 5.7) and high resolution (pH 7.1) broth media (1ml/tube), respectively. Results indicated that the minimal inhibitory and minimal fungicidal concentrations (MICs and MFCs) for the mycelial cultures of P. marneffei to AmB were in the range 0.78–1.56 and 0.78–3.125 g/ml, respectively, as against 3.125–25 g (MICs) for the yeast form cultures. The MFCs to AmB for the yeast form were one dilution higher. The MICs to FLU were generally lower for the yeast form (6.25–25 g) than the mycelial form (25–50 g/ml), whereas MFCs for the mycelial cultures were > 100 g as compared to 6.25–100 g for their yeast form. The MICs for the mycelial form to 5-FC ranged from < 0.195–0.39 g. Higher MICs (6.25 g) were recorded for their yeast form. The MFCs to 5-FC for the yeast form were 25–100 g/ml. The MICs for the mycelial form to ITZ ranged from < 0.195 to 3.125 g/ml. Higher values (< 0.195–50 g) were recorded for their yeast-like form. The MFCs to ITZ for mycelial and yeast forms ranged from < 0.195–0.39 and 25–100 g/ml, respectively. Results indicate that P. marnefei's yeast form is more sensitive to FLU and ITZ (8 of 10 strains) while the mycelial form displayed greater susceptibility to AmB and 5-FC. The MICs for ITZ remained steady in SD medium, pH 5.7 to 7.1. However, some strains gave higher MIC values (0.39–1.56 g/ml) when tested in the HR.     

Interregional foodborne salmonellosis outbreak due to powdered infant formula contaminated with lactose-fermenting Salmonella virchow

Spain's Salmonella surveillance system backed by regionally-based epidemiologists around the country made it possible to detect and halt the spread of a foodborne salmonellosis outbreak due to powdered infant formula contaminated with a lactose-fermenting strain of Salmonella virchow. Forty-eight cases involving children, mostly under 7 months old, were detected in 14 out of Spain's 17 Regions. The outbreak started in January and ended in June 1994. All cases were microbiologically confirmed. The implicated strain had a 3.6 kb plasmid, was susceptible to all antimicrobials tested except nitrofurantoin and was phagetype 4a. Isolates from 8 of 24 Brand A milk samples tested had the same characteristics as case isolates. All affected/suspect batches of Brand A milk were destroyed and the product withdrawn from sale, which led to the end of the outbreak. This incident underscores the importance of maintaining surveillance systems able to detect and prevent foodborne outbreaks and alert to the possibility of isolating unusual lactose-fermenting Salmonella serotypes in especially sensitive food products.     

Kidney function in stainless steel welders

Summary Seventeen male manual metal-arc stainless steel welders (mean exposure time 20 years) had far higher levels of chromium in urine than individually matched controls (medians 23 vs 1.5 mol/mol creatinine;10.5 vs 0.7 g/g creatinine). However, there were no signs of kidney damage in tests of function of tubuli (-hexosaminidase, lysozyme, and ₂-microglobuline) or glomeruli (albumine clearance).     

Heterosexual copulatory patterns in stumptail macaques (Macaca arctoides) and in other macaque species

A comparison of the mating behavior patterns of several macaque species reveals that the mating behavior of Macaca arctoidesexhibits several unique features. The laboratory groups of stumptail monkeys observed had exceptionally long single-mount copulations characterized by a large number of pelvic thrusts, a slow thrusting rate, and an unusually salient male orgasmic pattern (characterized by body rigidity followed by body spasms and a typical facial expression and vocalization). The frequency with which the copulation culminates in ejaculation is unusually high, and copulating stumptails generally manifest tieing in a genital lock after ejaculation. This research was supported in part by the Interdisciplinary Training Program, Langley Porter Neuropsychiatric Institute, University of California, San Francisco; by United States Public Health Service Training Grant No. 5-T1-MH-7082 from the National Institute of Public Health; and by Grant No. GS-31943X from the National Science Foundation to Dr. S. L. Washburn of the University of California at Berkeley, given for Primate Studies and Human Evolution.This paper was given as one part of the presentation prepared for the symposium Male and Female Sexual Behavior in Primate Societies, Fourth International Congress of Primatology, Portland, Oregon, August 1972. The first part was published as Male-Female, Female-Female, and Male-Male Sexual Behavior in the Stumptail Monkey, with Special Attention to the Female Orgasm,Archives of Sexual Behavior 3: 95–116, 1974.     

An evolutionary perspective of sex-typed toy preferences: pink,blue, and the brain

Large sex differences in children's toy preferences are attributed to gender group identification and social learning. The proposal outlined in this paper is that contemporary conceptual categories of masculine or feminine toys are also influenced by evolved perceptual categories of male-preferred and female-preferred objects. Research on children exposed prenatally to atypical levels of androgens and research on typically developing infants suggest sex-dimorphic preferences exist for object features, such as movement or color/form. The evolution and neurobiology of mammalian visual processing—and recent findings on sex-dimorphic toy preferences in nonhuman primates—suggest further that an innate bias for processing object movement or color/form may contribute to behaviors with differential adaptive significance for males and females. In this way, preferences for objects such as toys may indicate a biological preparedness for a masculine or feminine gender role—one that develops more fully as early perceptual preferences are coupled with object experiences imposed by contemporary gender socialization.     

Belgian collaborative study of the in-vitro susceptibility of the Bacteroides fragilis group

The antimicrobial susceptibility of clinical isolates of the Bacteroides fragilis group obtained from nine large Belgian university and community hospitals was studied. Of the -lactam antibiotics tested, none were active against 100% of the isolates. Piperacillin was active against 93% of the strains at a breakpoint of 64 lag/ml. The percentage of isolates inhibited at 16 g/ml (and 32 g/ml) for the 7-alpha-methoxy antibiotics was: cefoxitin 84 [94]; latamoxef 87 [93]; and cefotetan 64 [79]. B. fragilis tended to be more susceptible to all -lactams than the other members of the group.Among the non -lactam antibiotics, the resistance rate for minocycline, doxycycline, clindamycin and erythromycin (at a breakpoint of 4 g/ml) were l%, 4%, 14% and 34%, respectively. Like the -lactams, clindamycin was less active against non B. fragilis species of the group.Chloramphenicol, metronidazole and tinidazole were still active against 100% of the isolates at their breakpoint values (8 lag/ml).     

Occurrence of Borrelia burgdorferi sensu stricto, Borrelia garinii and Borrelia afzelii in the Ixodes ricinus ticks from Eastern Slovakia

A total of 2816 unfed adults nymphs of Ixodes ricinus ticks were collected from vegetation in Koice (Eastern Slovakia) from 1994 to 1997. Prevalence of Borrelia burgdorferi s. 1. in I. ricinus ticks, detected by dark field microscopy, varied and depended upon the year and the habitat of the collected ticks. The lowest prevalence was observed in 1994 (4.8%). During 1995 it increased to 17.2% and during the next two years decreased to 15.5% and 14.2%. The rate of infection varied from 2.1 to 23.3% within 10 examined habitats of the Koice area. A different value of relative density of ticks was observed in various habitats. It ranged from 9–212 ticks per collecting hour within one flagged area (600m²) which is 1.5–35.5 ticks per 100m². Eight isolates were obtained from the infected ticks. Electrophoresis and immunoblotting with 6 monoclonal antibodies were used for the identification of Borrelia strains. Three tick isolates were identified as B. burgdorferi s. s. and the other three isolates were found to be B. garinii. One strain reacted as a mixed culture of B. burgdorferi s. s., and B. garinii. The strain originated from the Vihorlat Mountains habitat and was detected by PCR-SSCP as B. burgdorferi s. s. with a small amount of B. afzelii. The obtained results emphasize the epidemiological importance not only of B. garinii and B. afzelii but also of B. burgdorferi s. s. in Central Europe.     

Psychosocial stressors associated with Mexican migrant farmworkers in the midwest United States

Although estimates suggest that there are upwards of 5 million migrant farmworkers in the United States, scant research has explored the stressors associated with their lifestyle. Contrary to previous work, the present study directly explored migrant farmworkers' own perceptions of what is difficult in their lives. The purposes of the present study were to qualitatively explore, from a phenomenological standpoint, the stressors associated with living as a migrant farmworker in the Midwest United States; and to determine the stressors that were most strongly related to symptoms of anxiety and depression. The findings indicated that 18 stressors were commonly experienced by the migrant farmworkers and that the farmworkers experienced overall elevated levels of anxiety and depression. A number of stressors that were not previously reported in the literature were identified. The stressors of rigid work demands and poor housing conditions were significantly associated with higher levels of anxiety and low family income/living in poverty and rigid work demands were significantly associated with depression. Implications of findings and prevention strategies are discussed.     

Chronic toxicity and bioaccumulation of 2,5,2′,5′- and 3,4,3′,4′-tetrachlorobiphenyl and Aroclor® 1242 in the amphipodHyalella azteca

The addition of 100 (g/L of Aroclor^® 1242 (A1242) or 2,5,2,5-tetrachlorobiphenyl (TeCB) during 10 week chronic toxicity tests withHyalella azteca resulted in complete mortality. There were no effects on survival, growth, or reproduction after addition of 30 g/L. Toxic effects were observed at tissue levels of between 30 and 180 g/g on a wet weight basis, and tissue levels appear to be a better indicator of toxicity than levels in water. No toxic effects were observed after additions of up to 2,700 g/L of the coplanar congener 3,4,3,4-TeCB.H. azteca has the ability to avoid accumulating in excess of 140 g/g 3,4,3,4-TeCB. The amount taken up was proportional to the amount added in water up to 100 g/L, but was constant at higher additions, possibly accounting for its relatively low toxicity. The low toxicity of the coplanar congener, as compared to the non-coplanar 2,5,2,5-TeCB, is in direct contrast to the high toxicity of coplanar PCB congeners to mammals and may be associated with slower rates of aromatic hydrocarbon metabolism in amphipods. Polychlorinated biphenyl levels measured in amphipods from Lake Ontario are approximately 100-fold below levels associated with toxicity inH. azteca, but are above levels which, through biomagnification up the food chain, lead to salmonid residues in excess of 2 g/g, a tolerance limit for human consumption.     

Chromatographic determination of dicofol and metabolites in egg yolks

Egg yolk was spiked withp,p-dicofol (p,p-DCF) (0.1–2.0 g/gm),p,p-dichlorobenzophenone (p,p-DCBP) (0.1–2.0 (g/gm), and 1,1-bis(4-chlorophenyl)-2,2-dichloroethylene (p,p- DDE) (0.05–1.0 g/gm). The fortified egg yolk (2–5 g) was mixed with acetonitrile to extract non-fat organic materials. After removal of acetonitrile, the spiked chemicals were separated with a column chromatograph packed with acid alumina. Recovery efficiencies forp,p-DCBP andp,p-DDE were determined by gas chromatography, and forp,p-dicofol by high performance liquid chromatography. The recovery efficiencies forp,p-dicofol,p,p-DCBP andp,p-DDE were 77.2–93.8%, 84.1–101.1%, and 88.5–96.0%, respectively.     

An assessment of a urinary biomarker for total human environmental exposure to benzo[a]pyrene

Urinary banzo[a]pyrene (BaP) metabolite levels were compared to human environmental exposure to BaP through inhalation and dietary ingestion to assess the predictive validity of the exposure biomarker. These measurements were made for 14 adult volunteers over 14 consecutive days, once during summer/fall, again during winter periods. Based on personal air monitoring, median potential inhalation doses of 11.0 and 2.3 ng/day were estimated for the winter and summer/fall studies, respectively. A median potential ingested dose of 176 ng/day, estimated from duplicate plate sampling, exceeded inhalation by 6-and 122-fold for the winter and summer/fall studies, respectively. Total urinary BaP metabolites were measured using a published reverse metabolism (BaP) method of analysis. Median rates of urinary BaP metabolite elimination for the winter and summer/fall studies were 121 and 129 ng/day, respectively. The changes in inhaled and ingested potential doses were regressed on the change in urinary metabolite elimination from week 1 to week 2 to test the predictive validity of the biomarker measurement. The regression was statistically significant (r = 0.620, p = 0.015, n = 25) when body weight was included and two extreme values were removed. Consistent with the exposure measurements showing diet as the dominant route of exposure, most of the variation in urinary metabolite elimination was explained by the ingested dose. It is concluded that the measurement of urinary BaP by reverse metabolism is qualitative and of marginal predictive validity as an exposure biomarker due to the method's low recoveries and the large unexplained variance.     

Dimensionen der Zufriedenheit im Alter

Zusammenfassung In einer Interview-Studie von 480 Betagten in städtischen Verhältnissen wurden neben anderen Fragen auch solche zur Zufriedenheit gestellt. Eine Faktoranalyse der Antworten erlaubt die Unterscheidung eines Faktors Depressivität von einem Faktor Zufriedenheit mit Sozial-kontakten und einer gesundheitlichen Dimension.

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Dimensions of satisfaction among old people

Summary In an interview study of 480 aged persons, questions on satisfaction with several aspects of life were included. A factor analysis allows to distinguish a factor relating to depressivity from a factor satisfaction with social contacts and a health-related dimension.

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Dimensions de la satisfaction des personnes âgées

Résumé Das une enquête d'un échantillon de 480 personnes âgées, des questions concernant leur satisfaction ont été inclues dans l'interview. Une analyse factorielle permet de distinguer un facteur associé à la dépressivité d'un facteur satisfaction avec les contactes sociaux et d'une dimension santé.

     

Performance of Number-Between g-Type Statistical Control Charts for Monitoring Adverse Events

Alternate Shewhart-type statistical control charts, called g and h charts, have been developed for monitoring the number of cases between hospital-acquired infections and other adverse events, such as heart surgery complications, catheter-related infections, surgical site infections, contaminated needle sticks, medication errors and other care induced concerns. This article investigates the statistical properties of these new charts and illustrates several design considerations that significantly can improve their operating characteristics and sensitivity, including the use of with-in limit rules, a new in-control rule, redefined Bernoulli trials, and probability-based limits. These new charts are based on inverse sampling from geometric and negative binomial distributions, are simple for practitioners to use, and in some cases exhibit significantly greater detection power over conventional binomial-based approaches, particularly for infrequent events and low defect rates.     

Bromacil and diuron herbicides: Toxicity,uptake, and elimination in freshwater fish

Fathead minnows, 30 days old, were exposed to technical grade bromacil and diuron in flow-through tests to determine acute toxicity. LC₅₀ values for bromacil were 185, 183, 182 and 167 mg/L at 24, 48, 96, and 168 hr, respectively; and for diuron, 23.3, 19.9, 14.2, and 7.7 mg/L at 24, 48, 96, and 192 hr, respectively. Eggs, newly hatched fry, and juvenile fish were continuously exposed to lower concentrations of the herbicides for 64 days. Growth was significantly reduced (p 0.01) at the lowest bromacil exposure of 1.0 mg/L. Therefore, it was not possible to determine a no effect concentration. The no effect concentration for diuron was 33.4 g/L, while the lowest concentration which resulted in adverse effects was 78.0 g/L. Adverse effects at 78.0 g/L were an increased incidence of abnormal or dead fry immediately after hatch (p 0.01) and decreased survival throughout the exposure period (p 0.05). Neither herbicide accumulated significantly in fish tissue, as bioconcentration factors were <3.2 and 2.0 for bromacil and diuron, respectively. Rainbow trout (Salmo gairdneri) injected with radiolabeled bromacil or diuron eliminated over 90% of the radioactivity within 24 hr. Parent compound and metabolites were detected in the aquarium water in both cases. Metabolites of diuron recovered from the water included 3,4-dichloroaniline and several demethylated products.     

Hard hats vs. soft hearts: The conflict between principles and reality in child and adolescent care and treatment programs

Much of child care in volves quick reactions based on one's automatic pilot derived from how we were parented. This paper is about two seemingly universal automatic pilot systems—the hard hats and the soft hearts. Hard hats are behavior management and modification oriented, while soft hearts are psychodynamically and counselling oriented. Typically, the hard hats tend to have the upper hand due to the nature of our culture, and they therefore have the effect of preventing the contributions of the soft hearts from being realized. That all too frequently sets up a dominant culture and a resentful minority situation. To correct this imbalance, a value orientation from the top which emphasizes mutual respect and utilization is suggested.Grateful acknowledgement is made to Ray Peterson for his helpful suggestions in the preparation of this paper.