A Rapid in vivo Bioassay for the Carcinogenicity of Pesticides

Eight pesticides were tested in a bioassay based on the induction of preneoplastic lesions in the liver. Rats were given diethylnitrosamine intraperitoneally at 200 mg/kg bw and two weeks later were treated with pesticides for six weeks and then killed; all rats had a partial hepatectomy at week 3. Hepatocarcinogenic potential was assessed by comparing the number and area of glutathione s-transferase (placental form) -positive foci In the liver with those of controls given diethylnitrosamine alone. Positive results were seen with Chinomethionat, Phosmet and Propiconazole; the results obtained with Captan and Prochloraz were borderline; Benomyl, Daminozide and Folpet gave negative results. Our findings provide enough experimental evidence to indicate that great care should be exercised in the use of these compounds.

Progressive lesions of central nervous system in microcephalic fetuses with suspected congenital Zika virus syndrome

OBJECTIVE

To describe the pattern and progression of central nervous system (CNS) lesions in microcephalic fetuses with suspected Zika virus (ZIKV) infection.

METHODS

In this prospective study in Salvador, Brazil, we analyzed fetuses diagnosed with microcephaly and suspected ZIKV infection after a routine primary care ultrasound scan between July 2015 and February 2016 raised suspicion of fetal microcephaly. The pregnancies were followed with serial ultrasound scans until delivery at one of the three main referral centers for fetal abnormalities in Salvador, Brazil. Microcephaly was diagnosed when the head circumference was two or more SDs below the mean for gestational age and its relationship with ZIKV infection was defined according to the World Health Organization's criteria. All women were interviewed, to assess potential factors associated with fetal microcephaly. Serology test results for toxoplasmosis, cytomegalovirus, rubella, syphilis and human immunodeficiency virus (HIV) were recorded, as were previous routine ultrasound results. Signs/symptoms of infection during the pregnancy were noted.

RESULTS

Of 60 cases of suspected ZIKV-related fetal microcephaly seen during the study period, eight were excluded due to serological evidence of other congenital infections or major ultrasound chromosomal markers. In the remaining 52 fetuses, microcephaly was diagnosed between 19 and 40 (median, 27.7; interquartile range, 23.4-32.0) weeks of gestation. The main ultrasound findings were: ventriculomegaly (65.4% of cases), cerebral calcifications (44.2%) and posterior fossa abnormalities (32.7%). 9.6% presented with arthrogryposis as an associated finding. Microcephaly was an isolated finding in four cases (7.7%). While ventriculomegaly was progressive in 41.2% of cases with this finding, the velocity of head circumference increase decreased progressively in almost all cases. Exanthematic disease was present in the majority (86.5%) of the women, 67.3% presenting in the first trimester of pregnancy. Additional lesions were detected after birth in 71.4% of the 35 cases with neonatal follow-up.

CONCLUSIONS

The majority of cases of congenital ZIKV syndrome have other ultrasonographic findings in addition to microcephaly. ZIKV-related CNS anomalies present mainly as progressive CNS lesions and slowing rate of growth of the fetal head, and this seems to be evident only in the late second trimester, even when maternal infection occurs in the first trimester. Other ultrasound findings, such as ventriculomegaly, brain calcifications and posterior fossa destruction lesions, are also common in this congenital syndrome. Posterior fossa destruction lesions and arthrogryposis are an uncommon finding in other congenital infections, perhaps suggesting a novel severe congenital syndrome associated with fetal ZIKV. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Early Identification and Linkage to Care for People with Chronic HBV and HCV Infection: The HepTLC Initiative

OBJECTIVE

In 2012, CDC's Division of Viral Hepatitis launched a public health initiative to increase hepatitis B virus (HBV) and hepatitis C virus (HCV) infection testing for those at risk and to improve linkage to medical care for those infected. We describe testing outcomes of previously unidentified people at risk for HBV and HCV infection and the lessons learned while linking patients to care.

METHODS

CDC's Hepatitis Testing and Linkage to Care (HepTLC) initiative provided 34 financial awards to U.S. organizations that serve people at risk for viral hepatitis, 25 of which focused on HCV and nine of which focused on HBV. Grantees offered testing and test result notification to people at risk for HBV and/or HCV infection, as well as counseling, referral, and verification or notification of linkage to care for people with positive test results. We entered demographic data, self-reported risk factors, country of origin (for HBV), and testing outcomes into a confidential database.

RESULTS

The 34 grantees tested 87,860 people at more than 260 sites in 17 states. Of the 23,144 people tested for HBV, 1,317 (6%) were positive. Of the 64,716 people tested for HCV, 57,570 (89%) received an HCV antibody (anti-HCV) test, of whom 7,580 (13%) tested anti-HCV positive. Of the 4,765 people who received an HCV RNA test, 3,449 (72%) tested positive. Of the 4,766 people who tested positive for either HBV or HCV infection, 2,116 (44%) were linked to care.

CONCLUSION

Interventions targeting people at risk for HBV and HCV infection reached a substantial number of people for whom testing is recommended and identified a large proportion of those who had previously unrecognized infection. Patient navigation was critical for follow-up and linkage to care.

Multiple nevoid basal cell carcinoma syndrome associated with congenital orbital teratoma, caused by a PTCH1 frameshift mutation

Gorlin-Goltz syndrome, or nevoid basal cell carcinoma syndrome (NBCCS), is a rare autosomal dominant disorder caused by mutations in the PTCH1 gene and shows a high level of penetrance and variable expressivity. The syndrome is characterized by developmental abnormalities or neoplasms and is diagnosed with 2 major criteria, or with 1 major and 2 minor criteria. Here, we report a new clinical manifestation associated with this syndrome in a boy affected by NBCCS who had congenital orbital teratoma at birth. Later, at the age of 15 years, he presented with 4 major and 4 minor criteria of NBCCS, including multiple basal cell carcinoma and 2 odontogenic keratocysts of the jaw, both confirmed by histology, more than 5 palmar pits, calcification of the cerebral falx, extensive meningeal calcifications, macrocephaly, hypertelorism, frontal bosses, and kyphoscoliosis. PTCH1 mutation analysis revealed the heterozygous germline mutation c.290dupA. This mutation generated a frameshift within exon 2 and an early premature stop codon (p.Asn97LysfsX43), predicting a truncated protein with complete loss of function. Identification of this mutation is useful for genetic counseling. Although the clinical symptoms are well-known, our case contributes to the understanding of phenotypic variability in NBCCS, highlighting that PTCH1 mutations cannot be used for predicting disease burden and reinforces the need of a multidisciplinary team in the diagnosis, treatment, and follow-up of NBCCS patients.

Early identification and linkage to care of persons with chronic hepatitis B virus infection--three U.S. sites, 2012-2014

In the United States, an estimated 0.8-1.4 million persons are living with chronic hepatitis B virus (HBV) infection. Among these persons, as many as 70% were born in countries of Asia, Africa, or other regions where HBV is moderately or highly endemic (hepatitis B surface antigen [HBsAg] prevalence ≥2%). HBV-associated cirrhosis and liver cancer are major health problems for these populations. Most persons with HBV were infected at birth or during early childhood and are asymptomatic until advanced liver disease develops. To address these concerns, CDC recommends HBsAg testing for all persons born in these areas and linkage to medical care and preventive services for those who are infected. In 2012, CDC awarded funds to nine sites to implement this recommendation. This report describes programs at three sites (New York, New York; Minneapolis-St. Paul, Minnesota; and San Diego, California) that conducted HBV testing, in clinical or community settings, and referred for medical evaluation and care those persons whose HBsAg test results were positive. During October 2012-March 2014, the three sites tested 4,727 persons for HBV infection; 310 (6.6%) were HBsAg-positive. Among the HBsAg-positive persons, 94% were informed of their results, 90% were counseled, 86% were referred for care, and 66% attended their scheduled first medical visit. These projects demonstrate that community-based programs can identify infected persons among populations with a high prevalence of HBV infection and refer HBsAg-positive persons for care. Individualized efforts to assist patients with accessing and receiving health-care services ("patient navigation services") can increase the number of persons who follow up on referrals and receive recommended care.

Nationwide outbreak of Salmonella enterica serotype Kedougou infection in infants linked to infant formula milk, Spain, 2008

On 5 August 2008, the National Reference Laboratory of Salmonella (NRLS) noted an increase in the number of isolates of Salmonella enterica serotype Kedougou. As of 22 August, 29 isolates have been reported during 2008, which is ten times more than the average number of isolates identified by the NRLS during 2002-2007. All isolates have a typical, indistinguishable Pulse Field pattern (SALKEDXB-1, Spanish code) and are fully sensitive to the standard suite of antimicrobials.

Prevalencia y consumo de medicación antidiabética en la Comunidad de Madrid (1996-2002)

OBJECTIVES/AIMS

To determine the prevalence of diabetes mellitus treated with drugs and the prescription of drugs in diabetes (oral anti-diabetics and insulin) in the Community of Madrid between 1996-2002.

METHODS

We used the indirect method for estimating the rate of prevalence of diabetes based on antidiabetic drug in the Madrid Community. We studied the consumption or oral antidiabetics (OH) and insulin (IN) in all the Madrid Community Area from 1996 to 2002. To make consumption uniform we used the daily doses/1,000 inhabitants/day (DHD). The total consumption was obtained using the official billing data and the annual population data provided by the "Institute Madrileño de Salud".

RESULTS

The prevalence of diabetes mellitus increased 62.5% in the period studied, ranging from 1.6% in 1996 up to 2.6% in 2002. The DHD of oral drugs increased 87.8% from 12.2 in 1996 to 23.07 in 2002. The DHD of insulin decreased 28.2% from 3.99 in 1996 down to 3.11 in 2002. The OH/IN ratio increased 138%, from 3.11 to 7.42 in 2002. There is a tendency to increase biguanide and sulfonilureas with low risk of hypoglycemia. The total cost of insulin and oral medication increase every year, the increase of diabetic patients and the cost/DDD of the new drugs are factors that increase the total cost of diabetes.

CONCLUSIONS

The prevalence of diabetes mellitus treated with drugs increased in the Community of Madrid. There is a progressive use of oral drugs versus insulin, and a tendency to prescribe biguanide, sulfonylureas, especially gliclazide and glimepiride. A tendency to substitute insulin with insulin analogues is also seen in the use of insulin. The cost of diabetes increases yearly.

The Y-chromosomal heritage of the Azores Islands population

The Azores, a Portuguese archipelago located in the north Atlantic Ocean, had no native population when the Portuguese first arrived in the 15th century. The islands were populated mainly by the Portuguese, but Jews, Moorish prisoners, African slaves, Flemish, French and Spaniards also contributed to the initial settlement. To understand the paternal origins and diversity of the extant Azorean population, we typed genomic DNA samples from 172 individuals using a combination of 10 Y-biallelic markers (YAP, SRY-1532, SRY-2627, 92R7, M9, sY81, Tat, SRY-8299, 12f2 and LLY22g) and the following Y-chromosomal STR systems: DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393 and DYS385. We identified nine different haplogroups, most of which are frequent in Europe. Haplogroup J* is the second most frequent in the Azores (13.4%), but it is modestly represented in mainland Portugal (6.8%). The other non-European haplogroups, N3 and E3a, which are prevalent in Asia and sub-Saharan Africa, respectively, have been found in the Azores (0.6% and 1.2%, respectively) but not in mainland Portugal. Microsatellite data indicate that the mean gene diversity (D) value for all the loci analysed in our sample set is 0.590, while haplotype diversity is 0.9994. Taken together, our analysis suggests that the current paternal pool of the Azorean population is, to a great extent, of Portuguese descent with significant contributions from people with other genetic backgrounds.

Reproductive health counseling at pregnancy testing: a pilot study

OBJECTIVES

To pilot brief reproductive health counseling for women obtaining pregnancy testing in a managed-care setting who did not desire pregnancy.

METHODS

Women received counseling, access to contraception and a booster call at 2 weeks. Changes in contraceptive behavior were evaluated.

RESULTS

Of 85 women who completed counseling, 58 (68%) completed follow-up. Participants reported that counseling was useful at baseline (94%) and follow-up (83%). The staff found the intervention important (100%) and implementation feasible (100%). Forty-one percent of participants improved their use of contraception (from no use or from less effective use to more effective use). Twenty-nine percent continued highly effective use and 9% recessed from highly effective use. Of 22 participants with risk of sexually transmitted disease, 3 (14%) began using condoms consistently, while 1 (5%) continued using condoms consistently.

CONCLUSIONS

Counseling at pregnancy testing was well accepted by the staff and participants. Observed behavioral changes suggest that this intervention may be effective in increasing effective use of contraception.

Applying motivational interviewing to contraceptive counseling: ESP for clinicians

Healthcare providers are in a unique position to address women's risk of unintended pregnancy and sexually transmitted infections (STIs), yet evidence for effective counseling strategies is limited. One approach to developing effective contraceptive counseling methods may be the application of theory-based behavior counseling models. One such model, motivational interviewing (MI), is a promising approach for addressing risk-taking behaviors of many kinds. We propose application of MI to contraceptive counseling. This process, ESP, involves Exploring discrepancies between pregnancy intention and contraceptive use and between risk of STIs and condom use, Sharing information and Promoting behaviors to reduce risk. This model emphasizes the importance of identifying discrepancies between goals and behaviors and supporting women's confidence in using appropriate contraceptive methods

Complete myocardial revascularization using arterial grafts

BACKGROUND

Complete arterial revascularization is important in younger patients to reduce the likelihood of future reoperation. We assessed the short-term outcome of a strategy to provide complete arterial revascularization in a cohort of young patients.

METHODS

Three hundred and eighty-five patients underwent myocardial revascularization using artery grafts alone and were followed up for 30 months. One hundred fourteen patients (29.6%) had single-vessel disease, 118 (30.6%) had two-vessel disease, and 153 (39.7%) had three or more obstructed coronary arteries. Eight of the patients had undergone previous surgical revascularization. The left internal thoracic artery (LITA) was routinely used for the left anterior descending branch (LAD). In 103 patients (28.1%), the in situ right internal thoracic artery (RITA) was used for revascularization of the right coronary artery (RCA) and its branches. The RITA was sometimes used as a free graft from the aorta or as an artificial "Y" from the LITA to the diagonal and marginal branches. Other arterial conduits included the radial artery (RA) in 215 patients (55.8%), the right gastroepiploic artery (RGEA) in 24 patients (6.3%), and the inferior epigastric artery (IEA) in four patients (1.1%).

RESULTS

In patients having lesions in three or more arteries, the mean number of distal anastomoses was 3.2 per patient. There were no intraoperative deaths. Hospital mortality was 1.8% (n = 7). Of the fatal cases, two were redos and two underwent combined procedures (one for left ventricular aneurysm and one for double valve replacement), while only three of the fatal cases underwent revascularization as a primary and isolated procedure.

CONCLUSIONS

Complete arterial reconstruction carries an acceptably low operative mortality and excellent short-term follow-up. This strategy is particularly important for young patients to reduce the probability of future reoperation.

Psychosocial factors associated with self-reported male condom use among women attending public health clinics

BACKGROUND

Previous research has identified factors associated with condom use. However, less information exists on the impact that a history of sexually transmitted disease (STD) has on condom use.

GOAL

To identify factors associated with self-reported male condom use that relate to a history of STD.

STUDY DESIGN

Women attending STD clinics completed a survey that assessed sexual behavior, STD history, and psychosocial characteristics. Binomial regression was used to estimate the association between these factors and condom use.

RESULTS

Of the 12 factors included in the regression model, 11 were significant for all women. When the analysis was stratified by STD history, high condom use self-efficacy, high convenience of condom use, and high frequency of condom use requests were significantly associated with increased condom use among women with or without a history of STD. Factors such as greater perceived condom use norms, higher perceived level of risk, and greater need for condom use in long-term relationships were significantly associated with increased condom use among women with a history of STD. Factors such as shorter duration of a relationship, less violence in the relationship, and lifetime drug use were associated with increased condom use among women with no history of STD.

CONCLUSIONS

The pattern of psychosocial factors determining condom use is modified by a positive history of STD. These findings suggest that a history of STD could be an important factor in targeting condom use interventions.

Long-term effectiveness of a peer-based intervention to promote condom and contraceptive use among HIV-positive and at-risk women

OBJECTIVE

The authors used data from a larger study to evaluate the long-term effects of a peer advocate intervention on condom and contraceptive use among HIV-infected women and women at high risk for HIV infection.

METHODS

HIV-infected women in one study and women at high risk for HIV infection in a second study were selected from the Women and Infants Demonstration Project and assigned to a standard or an enhanced HIV prevention treatment group. The enhanced intervention included support groups and one-on-one contacts with peer advocates tailored to clients' needs. The authors interviewed women at baseline and at 6-, 12- and 18-months, and measured changes in consistency of condom and contraceptive use and in self-efficacy and perceived advantages and disadvantages of condom and contraceptive use.

RESULTS

Of HIV-infected women, the enhanced group had improved consistency in condom use, increased perceived advantages of condom use, and increased level of self-efficacy compared with the standard group. Of women at risk, the enhanced intervention group at six months maintained consistent condom use with a main partner and perceived more benefit of condom use compared with the standard group. These differences diminished at 12 months.

CONCLUSIONS

The enhanced intervention was generally effective in the HIV+ study. In the at-risk study, however, intervention effects were minimal and short-lived. Factors related to the theory, intervention design, and sample characteristics help explain these differences.

Female condom use among women at high risk of sexually transmitted disease

CONTEXT

Whereas the female condom has been evaluated in many hypothetical acceptability or short-term use studies, there is little information about its suitability for the prevention of sexually transmitted diseases (STDs) or HIV over extended periods of time.

METHODOLOGY

As part of a six-month prospective follow-up study of 1,159 STD clinic patients, clients were interviewed during their initial visit, exposed to a behavioral intervention promoting condoms, given a physical examination and provided with instructions on completing a sexual diary. Potential predictors of trying the female condom were evaluated using logistic regression, and three condom-use groups (exclusive users of female condoms, exclusive users of male condoms and users of both types of condoms) were compared using multinomial regression.

RESULTS

Among 895 women who reported having engaged in vaginal intercourse during the study period, one-half had sex with only one partner, while one-quarter each had two partners or three or more partners. A total of 731 women reported using the female condom at least once during the follow-up period--85% during the first month of follow-up. Multiple logistic regression analyses indicated that employed women and those with a regular sexual partner at baseline were significantly more likely to try the female condom. By the end of the follow-up period, 8% of participants had used the female condom exclusively, 15% had used the male condom exclusively, 73% had used both types of condom and 3% had used no condoms. Twenty percent of women who tried the female condom used it only once and 13% used it twice, while 20% used 5-9 female condoms and 32% used 10 or more. Consistent condom users (N=309) were predominantly users of both types of condom (75%), and were less often exclusive users of the male condom (18%) or the female condom (7%). According to a multivariate analysis, women who used the female condom exclusively or who mixed condom types were more likely to be black, were more likely to be employed and were more likely to have a regular partner than were users of the male condom.

CONCLUSIONS

Women at risk of STDs find the female condom acceptable and will try it, and some use it consistently. Mixing use of female condoms and male condoms may facilitate consistent condom use. The female condom may improve an individual's options for risk reduction and help reduce the spread of STDs.

[Aids neurologic manifestations in childhood]

INTRODUCTION

Children with AIDS get infected mainly by vertical transmission.

DEVELOPMENT

That was what happened in 90% of the cases in a series of 340 HIV+ children followed at Hospital de Clínicas de Porto Alegre, Brazil. Currently, after the use of prophylactic treatment during pregnancy and the six first weeks of life, our transmission rate is 3% to 4%. The incidence of neurologic complications in the vertical transmission group was 49% in our prospective series, and due either to immunosuppression or primary neurological disease. Neurologic changes secondary to HIV constitute a complex syndrome, manifested by various degrees of cognitive, motor and behavioral delay. Encephalopathy can be either progressive or static. In our series, encephalopathy occurred in 32.5% of cases, developmental delay in 42.5%, seizures in 6%, speech delay in 5%, headaches in 2.5% and behavioral disorders in 2%. Central nervous system infections happened in 33.8% of our cases: acute bacterial infections in 11%, cytomegalovirus in 6.8%, toxoplasmosis in 5.9%, cryptococcal in 5%, tuberculous in 3.8% and syphilis in 1.3%. Hemorrhagic cerebrovascular accidents were seen in 2.5% of our cases, and peripheral neuropathy in 5%. Seventy percent of our cases had abnormalities in the CSF, 75% in brain CT scans and 45% in EEGs.

CONCLUSIONS

Treatment of children with AIDS and neurologic manifestations was based on specific drugs aimed at controlling viral replication. Best response was obtained with combined use of AZT and other anti-retroviral neuro-protective.

Policies for developing workplace violence prevention strategies

The paradox that some strategies to prevent workplace violence may actually increase the potential for violence is addressed. Strategies that might prevent crime-related internecine workplace violence are described and several ineffective and even potentially deleterious strategies examined.

Medium-term bioassay for the hepatocarcinogenicity of hexachlorobenzene

Hexachlorobenzene (HCB) is an important environmental contaminant derived mainly from industrial and agricultural sources. It is carcinogenic in mice, rats and hamsters. It has now been studied in a medium-term bioassay for carcinogenicity based on the induction of preneoplastic lesions in the liver. We report here that the bioassay can rapidly detect carcinogenic doses of HCB and that there is a clear dose-response relationship. At the lowest dose of HCB administered, the incidence of preneoplastic lesions in the liver was no different from that in controls.

Lack of carcinogenicity of daminozide, alone or in combination with its contaminant 1,1-dimethylhydrazine, in a medium-term bioassay

The carcinogenicity of daminozide (succinic acid-2,2-dimethylhydrazide; Alar), a plant growth regulator used primarily in apple orchards, has been the subject of recent investigations by several national and international organizations because of contradictory study results. The aim of the present study was to assess the carcinogenicity of daminozide alone and in combination with 1,1-dimethylhydrazine (UDMH), its major contaminant, in a novel medium-term bioassay in Fischer 344 rats, the DEN-PH model. Rats were given diethylnitrosamine (DEN) at 200 mg/kg body weight intraperitoneally and then 2 weeks later were given daminozide at 20,000 ppm or daminozide plus UDMH at 75, 150, or 300 ppm in the diet for 6 weeks and were then killed; all rats underwent a partial (two-thirds) hepatectomy (PH) at week 3. Hepatocarcinogenic potential was assessed by comparing the number and area of preneoplastic foci positive for the glutathione S-transferase placental form (GST-P+) in the liver of treated rats, with those in controls given DEN alone. Daminozide, UDMH, and the combination were not carcinogenic in this model. This novel medium-term bioassay for carcinogenicity is considered to be practical for the rapid evaluation of both agrochemical formulations and contaminants found in agrochemicals and other compounds.

Recent epidemics of poisoning by pesticides

The mechanisms of production of collective poisoning by pesticides have been contamination of foods consumed by man, cutaneous contact and occupational exposure. It is possible to distinguish 4 groups of alimentary epidemics: (1) contamination during transport or storage; (2) ingestion of seed dressed for sowing: (3) use of pesticides in food preparation because of their organoleptic similarity to alimentary products; (4) presence of pesticides in water or food owing to unsafe use of pesticides. Occupational exposure affects clusters of workers in pesticide manufacture, pesticide application and crop management. Some episodes of every kind of the mentioned groups have been published recently.

Progesterone and pregnanolone derivatives relaxing effect on smooth muscle

1. The effect of gestagens, 5 alpha-hydroxyprogesterone (10(-6) x 10(-5) M), 5 beta-hydroxyprogesterone (10(-6)-3 x 10(-5) M), progesterone (6 x 10(-6)-10(-4) M), pregnanolone (10(-6)-10(-5) M), allopregnanolone (10(-6)-10(-4) M) and epipregnanolone (10(-6)-6 x 10(-5) M) on rat uterine contractions induced by KCl (60 mM), has been assayed. 2. All drugs assayed relaxed the tonic-contraction induced by KCl in a concentration-dependent way. The respectives IC50 were 31.3 +/- 4.1 x 10(-6) M (progesterone), 8.9 +/- 0.8 x 10(-6) M (5 alpha-hydroxyprogesterone), 3.8 +/- 0.3 x 10(-6) M (5 beta-hydroxyprogesterone), 3.1 +/- 0.1 x 10(-6) M (pregnanolone), 21.2 +/- 3.1 x 10(-6) M (allopregnanolone) and 6.3 +/- 1.3 x 10(-6) M (epipregnanolone). This relaxing effect was partially or totally counteracted by CaCl2 (1-10 mM) 3. Cycloheximide (10 micrograms/ml) significantly shifted to the right the effect of allopregnanolone but not the effect of the other drugs. Actinomycin D (5 micrograms/ml) did not modify the effect of allopregnanolone. 4. Our results suggest that the relaxing effect of gestagens in the rat uterus could be related to inhibition on calcium influx and mainly occur through non-genomic mechanisms.

G-->A mutations in p53 and Ha-ras genes in esophageal papillomas induced by N-nitrosomethylbenzylamine in two strains of rats

In human esophageal cancers, no ras gene mutations but a relatively high prevalence of p53 gene mutations have been reported. We found a high prevalence of point mutations in Ha-ras and p53 genes in N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumors in two strains of rats (BD VI and F344). Our analysis showed the point mutation GGA-->GAA (expected from the known mechanisms of action of NMBA) at Ha-ras codon 12 in 22 of 46 (48%) and 22 of 38 (58%) papillomas from BD VI and F344 rats, respectively. There was no significant difference in the prevalence of ras mutations in tumors induced by high doses (5.0 mg/kg) and low doses (2.5 mg/kg) of NMBA. Eleven papillomas from each strain were analyzed for p53 mutations. The prevalent mutations found were G-->A and C-->T transitions. The frequency of p53 mutation was 36% (four of 11) for each strain. No apparent hot-spot codon or exon was found in the p53 gene, and two papillomas contained double mutations in this gene. The high prevalence of G-->A mutations in the rat Ha-ras gene contrasts with that in the human gene, in which no ras mutations have been found in primary tumors, and suggests either that the biology of esophageal carcinogenesis differs in humans and rats or that nitrosamines are not the major etiological risk factor for human esophageal cancers.

Enhancement by non-mutagenic pesticides of GST-P positive hepatic foci development initiated with diethylnitrosamine in the rat

The potential hepatocarcinogenicity of seven pesticides was examined using a rapid bioassay based on the induction of glutathione S-transferase placental form positive foci in the rat liver. Rats were initially injected with diethylnitrosamine and two weeks later were fed on diet supplemented with one of the pesticides for 6 weeks and then killed; all rats were subjected to a partial hepatectomy at week 3. Positive results were seen with chlorobenzilate (2000 ppm), vinclozolin (2000 ppm), malathion (4000 ppm), tecnazene (2000 ppm) and isoproturon (2000 ppm). S,S,S-tributylphosphorotrithioate (DEF, 200 ppm) and dicloran (2000 ppm) were negative in both number and area analyses. Although chlorobenzilate is carcinogenic in mice, malathion and vinclozolin have been reported as non-carcinogens in both rats and mice. Since the present system is based on the two-stage carcinogenesis hypothesis, it is possible that the chemicals showing positive results in this system possess at least tumor-promoting activity in the rat liver. This is very significant, as most carcinogens show tumor-promoting activity in their target organs.

Carcinogenic potential of some pesticides in a medium-term multi-organ bioassay in rats

The carcinogenic potential of 5 pesticides was analyzed using a medium-term multi-organ bioassay for carcinogenicity. Male F344 rats were initially treated with 3 known carcinogens (diethylnitrosamine, N-methyl-N-nitrosourea and N-bis(2-hydroxypropyl)nitrosamine) during a period of 4 weeks to induce neoplastic changes in a variety of organs, and then given one of 5 pesticides in the diet for a further 16 weeks. Neoplastic and pre-neoplastic lesions were found in the thyroid, kidney and urinary bladder with propineb, in the forestomach, kidney and thyroid with captan and folpet. The number of glutathione S-transferase placental-form-positive liver-cell foci was significantly increased in the captan- and phosmet-treated groups. Based on these findings, captan and propineb can be considered as carcinogens and carcinogenicity is suspected for folpet and phosmet. These results are in concordance with reported long-term carcinogenicity for captan, folpet and propineb. Daminozide was considered not to be carcinogenic. Thus, the present assay of 20 weeks' duration is useful for the prediction of potential carcinogens.

Demonstration of initiation potential of carcinogens by induction of preneoplastic glutathione S-transferase P-form-positive liver cell foci: possible in vivo assay system for environmental carcinogens

In a development trial for an initiation bioassay system, 7 known carcinogens and 1 suspected carcinogen were examined. In experiment 1, group 1 animals were initially subjected to partial hepatectomy (PH) 12 h before administration of diethylnitrosamine, 2-amino-3-methylimidazo[4,5-f]-quinoline (IQ), captafol, alpha-hexachlorocyclohexane or diethylstilbestrol (DES), then 2 weeks later underwent a promotion procedure comprising administration of phenobarbital (0.05% in diet) for 8 weeks and D-galactosamine (300 mg/kg, i.g.) at week 3. Group 2 received the promotion protocol alone as in group 1. Initiating potential was assayed on the basis of significant increase in values of preneoplastic placental form glutathione S-transferase-positive (GST-P+) foci of more than 3 cells in cross section at week 10. Numbers and areas of GST-P+ foci in group 1 given IQ, captafol and DES were significantly increased as compared to group 2, confirming the validity of the protocol as an initiation assay. In Experiment 2, group 1 rats were subjected to PH and 12 h later received a suspected carcinogenic mixture of opium pyrolysate (OP) or carcinogenic pesticide p,p'-dichloro-diphenyltrichloroethane or hexachlorobenzene. Application of a modified promotion procedure comprising cholic acid (0.15%) and carbon tetrachloride (1 ml/kg, i.g.) revealed significant initiation potential for OP. Overall the results indicate that the current protocols may be useful for detection of the initiation potential of carcinogens irrespective of their mutagenicity.

Analysis of carcinogenic activity of some pesticides in a medium-term liver bioassay in the rat

Eight pesticides were tested in a medium-term bioassay based upon the induction of preneoplastic lesions in the liver. Rats were initially given diethylnitrosamine intraperitoneally at a dose of 200 mg/kg body weight and 2 weeks later were treated with the pesticides for 6 weeks and then killed; all rats had a partial hepatectomy at week 3. Hepatocarcinogenic potential was assessed by comparing the number and area of glutathione S-transferase placental form positive foci in the liver with those of controls given diethylnitrosamine (DEN) alone. Positive results were seen with p,p-DDT and Triadimefon. Permethrin (mixture of 39% cis form and 61% trans form) showed borderline results. Permethrin (25/75), Deltamethrin, Cypermethrin (52/48), while Trimorphamide and Propineb gave negative results. Our findings provide experimental evidence to indicate that compounds active in this assay have a potential for liver carcinogenicity in rodents.

Toxic epidemics caused by alimentary exposure to pesticides: a review

Toxic epidemics have become a serious problem during the twentieth century, due mainly to the huge expansion over the last 50 years of the chemical industry, which has placed tens of thousands of new synthetic organic compounds in the human environment. In the particular case of chemical pesticides, their undiscriminating, widespread use, and harmful potential has been demonstrated by the epidemics generated by accidental contamination by pesticides of foods consumed by man, resulting in high mortality and morbidity rates. We have analysed the main characteristics of 63 outbreaks of toxicity caused by alimentary exposure to pesticides described in the scientific literature of this century, with the aim of increasing knowledge and understanding of the factors that are conducive to them or that trigger their onset. Such episodes are good indicators of the incorrect use of these products and serve to demonstrate failures of the available safety systems. We conclude by identifying some preventive measures that could be used to avoid their future repetition.

Carcinogenicity of captafol in F344/DuCrj rats

Captafol was administered at dietary levels of 0 (control), 750 and 1,500 parts per million (ppm) to groups of 50 male and 50 female F344/DuCrj rats for 104 weeks, and then all animals were maintained without captafol for a further 8 weeks, and killed in week 113. Renal cell carcinoma was found in eight of 50 male rats treated with 1,500 ppm and in one of 50 male rats treated with 750 ppm of captafol. The incidences of renal adenomas, including micro-adenomas, and basophilic altered cell tubules were significantly higher in both sexes treated with captafol than in controls, and the increases were apparently dose-dependent except that of adenomas in females. The incidences of neoplastic and preneoplastic lesions of the kidney in captafol-treated animals were higher in males than in females. Captafol also induced hepatocellular carcinomas in four of 50 female rats in the 1,500 ppm group. The incidences of hyperplastic (neoplastic) nodules and foci of cellular alterations in the liver were also significantly increased in both sexes treated with captafol, the increases being dose-dependent. In conclusion, captafol induced renal cell carcinomas in male rats and hepatocellular carcinomas in female rats.

Hodgkin disease clinical stages I, II, and III (A, B): results of radiotherapy with or without chemotherapy

Between 1961 and 1976, 387 patients with Hodgkin disease were examined, evaluated, and treated at the Instituto Portugues de Oncologia de Francisco Gentil. After reviewing histological and clinical staging presentation, the authors retrospectively analyzed the results obtained with 303 patients classified in clinical stages I, II, and III (A, B) who were treated with or without chemotherapy in two time periods (before and after 1970) according to individual therapeutic modalities. The improvement of the 5-year survival rates in the last period was associated with the introduction of extended-field irradiation and multidrug chemotherapy (MOPP). However, the incidence of serious complications was higher in the group of patients subjected to combined field irradiation and MOPP. The authors suggest a stricter protocol based on the current recommendations for the treatment of Hodgkin disease in order to achieve better results with minimum possible hazards.