Perinatal exposure to the fungicide prochloraz feminizes the male rat offspring.

Prochloraz is a commonly used fungicide that has shown multiple mechanisms of action in vitro. It antagonizes the androgen and the estrogen receptors, agonizes the Ah receptor, and inhibits aromatase activity. In vivo prochloraz acts antiandrogenically in the Hershberger assay by reducing weights of reproductive organs, affecting androgen-regulated gene expressions, and increasing luteinizing hormone (LH) levels. The purpose of this study was to investigate reproductive toxic effects after exposure during gestation and lactation to prochloraz alone and a mixture of five pesticides (deltamethrin, methiocarb, prochloraz, simazine, and tribenuron-methyl). Prochloraz (30 mg/kg/day) or the mixture (20 mg/kg/day) was dosed to pregnant Wistar dams from gestational day (GD) 7 until postnatal day (PND) 16. Some dams were taken for cesarean section at GD 21, and others were allowed to give birth. Results showed that prochloraz and the mixture significantly reduced plasma and testicular testosterone levels in GD 21 male fetuses, whereas testicular progesterone was increased. Gestational length was increased by prochloraz. Chemical analysis of the rat breast milk showed that prochloraz was transferred to the milk. In males a significant increase of nipple retention was found, and the bulbourethral gland weight was decreased, whereas other reproductive organs were unaffected. In addition cytochrome P450 (CYP)1A activities in livers were induced by prochloraz, possibly as a result of Ah receptor activation. Behavioral studies showed that the activity level and sweet preference of adult males were significantly increased. Overall these results strongly indicate that prochloraz feminizes the male offspring after perinatal exposure, and that these effects are due, at least in part, to diminished fetal steroidogenesis.     

Update in Outpatient General Internal Medicine: Practice-Changing Evidence Published in 2020

In a time of rapidly shifting evidence-based medicine, it is challenging to stay informed of research that modifies clinical practice. To enhance knowledge of practice-changing literature, a group of 7 internists reviewed titles and abstracts in 7 internal medicine journals with the highest impact factors and relevance to outpatient general internal medicine. Coronavirus disease-19 research was purposely excluded to highlight practice changes beyond the pandemic. New England Journal of Medicine (NEJM), The Lancet, Annals of Internal Medicine, Journal of the American Medical Association (JAMA), JAMA Internal Medicine, British Medical Journal (BMJ), and Public Library of Science (PLoS) Medicine were reviewed. The following collections of article synopses and databases were also reviewed: American College of Physicians Journal Club, NEJM Journal Watch, BMJ Evidence-Based Medicine, McMaster/DynaMed Evidence Alerts, and Cochrane Reviews. A modified Delphi method was used to gain consensus based on relevance to outpatient internal medicine, impact on practice, and strength of evidence. Clusters of articles pertaining to the same topic were considered together. In total, 7 practice-changing articles were included.     

Urological symptoms among 23,240 men in the general danish population – concerns about symptoms,their persistence and influence on primary care contacts

Objective: To analyse possible associations between men’s likelihood of contacting a general practitioner (GP) for urological symptoms and the persistence of the symptoms, the influence on daily activities and the level of concern about the symptoms.

Design: Web-based nationwide cross-sectional questionnaire study.

Setting: The general population in Denmark.

Subjects: 48,910 randomly selected men aged 20+ years.

Main outcome measures: Urological symptom prevalence and odds ratios for GP contact with urological symptoms in regard to concern for the symptom, influence on daily activities and the persistence of the symptom.

Results: Some 23,240 men responded to the questionnaire, yielding a response rate of 49.8%. The prevalence of at least one urological symptom was 59.9%. Among men experiencing at least one urological symptom almost one-fourth reported contact to general practice regarding the symptom. Approximately half of the symptoms reported to be extremely concerning were discussed with a GP.

Conclusion: Increased symptom concern, influence on daily activities and long-term persistence increased the likelihood of contacting a GP with urological symptoms. This research points out that guidelines for PSA testing might be challenged by the high prevalence of urological symptoms.

• Key points

• ?The decision process of whether to contact the general practitioner (GP) is influenced by different factors, but contradictory results has been found in triggers and barriers for help-seeking with urological symptoms.

• ??Increased symptom concern, influence on daily activities and long-term persistence consistently increased the likelihood of contacting a general practitioner with urological symptoms in men.

• ??Only 50% of the symptoms reported to be extremely concerning were however discussed with the GP.

• ??Guidelines for PSA testing might be challenged by the high prevalence of urological symptoms.

     

Association between alcohol consumption and plasma fetuin-A and its contribution to incident type 2 diabetes in women

Aims/hypothesis

The benefits of moderate alcohol consumption for type 2 diabetes have been postulated to involve a mechanism of improved insulin sensitivity. Fetuin-A, which is known to inhibit insulin signalling, has emerged as a biomarker for diabetes risk. Alcohol consumption may influence circulating fetuin-A concentrations and subsequently diabetes risk by altering the insulin signal. We therefore hypothesised that moderate alcohol consumption would be associated with lower fetuin-A concentration and that fetuin-A would partly explain the association between alcohol consumption and incident type 2 diabetes.

Methods

Among diabetes-free female participants in the Nurses’ Health Study (n?=?1,331), multiple linear regression was conducted to assess the association between alcohol consumption and plasma fetuin-A. Least-squares means (lsmeans) of fetuin-A were estimated in categories of alcohol consumption (0, 0.1–4.9, 5–14.9 and ≥15 g/day). The proportion of alcohol consumption and diabetes association explained by baseline fetuin-A was assessed in 470 matched incident diabetes case–control pairs with follow-up 2000–2006.

Results

Higher alcohol consumption was associated with lower plasma fetuin-A (p for trend?=?0.009): lsmean ± SE 476.5?±?5.9 μg/ml for abstainers, 468.9?±?5.2 μg/ml for 0.1–4.9 g/day consumers, 455.9?±?7.0 μg/ml for 5.0–14.9 g/day consumers, and 450.0?±?9.4 μg/ml for ≥15.0 g/day consumers. Fetuin-A and fasting insulin explained 18.4% and 54.8%, respectively, of the inverse association between alcohol consumption and diabetes after multiple adjustment (both p for contribution <0.04).

Conclusions/interpretation

Moderate alcohol consumption is associated with lower plasma fetuin-A in diabetes-free women. Fetuin-A and insulin explain a significant proportion of the association between alcohol consumption and incident type 2 diabetes. Further studies are needed to examine potential biological mechanisms underlying this association.     

Tumor initiating but differentiated luminal-like breast cancer cells are highly invasive in the absence of basal-like activity

The majority of human breast cancers exhibit luminal epithelial differentiation. However, most aggressive behavior, including invasion and purported cancer stem cell activity, are considered characteristics of basal-like cells. We asked the following questions: Must luminal-like breast cancer cells become basal-like to initiate tumors or to invade? Could luminally differentiated cells within a basally initiated hierarchy also be tumorigenic? To answer these questions, we used rare and mutually exclusive lineage markers to isolate subsets of luminal-like and basal-like cells from human breast tumors. We enriched for populations with or without prominent basal-like traits from individual tumors or single cell cloning from cell lines and recovered cells with a luminal-like phenotype. Tumor cells with basal-like traits mimicked phenotypic and functional behavior associated with stem cells assessed by gene expression, mammosphere formation and lineage markers. Luminal-like cells without basal-like traits, surprisingly, were fully capable of initiating invasive tumors in NOD SCID gamma (NSG) mice. In fact, these phenotypically pure luminal-like cells generated larger and more invasive tumors than their basal-like counterparts. The tumorigenicity and invasive potential of the luminal-like cancer cells relied strongly on the expression of the gene GCNT1, which encodes a key glycosyltransferase controlling O-glycan branching. These findings demonstrate that basal-like cells, as defined currently, are not a requirement for breast tumor aggressiveness, and that within a single tumor there are multiple “stem-like” cells with tumorigenic potential casting some doubt on the hypothesis of hierarchical or differentiative loss of tumorigenicity.     

Endocrine-disrupting activities in vivo of the fungicides tebuconazole and epoxiconazole.

The triazole fungicides tebuconazole and epoxiconazole were investigated for reproductive toxic effects after exposure during gestation and lactation. Rats were dosed with epoxiconazole (15 or 50 mg/kg bw/day) or tebuconazole (50 or 100 mg/kg bw/day) during pregnancy from gestational day (GD) 7 and continued during lactation until postnatal day (PND) 16. Some dams were randomly chosen for cesarean section at GD 21 to evaluate effects on sexual differentiation in the fetuses. Other dams delivered normally, and the pups were examined (e.g., anogenital distance [AGD] and hormone levels) at birth, at PND 13 or PND 16, and semen quality was assessed in adults. Both tebuconazole and epoxiconazole affected reproductive development in the offspring after exposure in utero. Both compounds virilized the female offspring as shown by an increased AGD PND 0. Furthermore, tebuconazole had a feminizing effect on male offspring as shown by increased nipple retention. This effect was likely caused by the reduced testosterone levels seen in male fetuses. Tebuconazole increased the testicular concentrations of progesterone and 17alpha-hydroxyprogesterone in male fetuses, indicating a direct impact on the steroid synthesis pathway in the Leydig cells. The high dose of epoxiconazole had marked fetotoxic effects, while the lower dose caused increased birth weights. The increased birth weights may be explained by a marked increase in testosterone levels in dams during gestation. Common features for azole fungicides are that they increase gestational length, virilize female pups, and affect steroid hormone levels in fetuses and/or dams. These effects strongly indicate that one major underlying mechanism for the endocrine-disrupting effects of azole fungicides is disturbance of key enzymes like CYP17 involved in the synthesis of steroid hormones.     

Defining functional drug-interaction domains on topoisomerase II by exploiting mechanistic differences between drug classes

Topoisomerase II is the primary cellular target for a variety of antineoplastic drugs that are active against human cancers. These drugs exert their cytotoxic effects by stabilizing covalent topoisomerase II-cleaved DNA complexes that are fleeting intermediates in the catalytic cycle of the enzyme. Despite this common feature of drug action, a number of mechanistic differences between drug classes have been described. These mechanistic differences (including effects on DNA cleavage/religation, DNA strand passage, and adenosine triphosphate hydrolysis) were used as the basis for a series of competition experiments to determine whether different compounds share a common site of action on topoisomerase II or interact at distinct sites. Results of the present study strongly suggest that at least four structurally disparate antineoplastic drugs, etoposide, amsacrine, genistein, and the quinolone CP-115,953, share an overlapping interaction domain on the enzyme.Paper presented at the Topoisomerase Inhibitors Conference, University of Maryland Cancer Center, 27–30 October 1993, Monterey, California, USA. Supported in part by Bristol Myers Oncology Division     

Nonlinear relation between alcohol intake and high-density lipoprotein cholesterol level: results from the Copenhagen City Heart Study

BACKGROUND: It has been suggested that the level of high-density lipoprotein cholesterol (HDL-C) in the blood can be used as a marker of recent alcohol intake. However, before using HDL-C as a predictor of alcoholism, the relation between alcohol intake and HDL-C in the entire range of consumption must be explored. Most studies model the relation between alcohol intake and HDL-C linearly, although a threshold effect is expected. The objective of this study was to evaluate the shape of the relation between intake of alcohol and HDL-C and to determine whether there are differential effects of beer, wine, and spirits on HDL-C and whether they remain after adjusting for total alcohol. METHOD: The relation between alcohol intake and HDL-C was investigated by means of generalized additive models using data from the Copenhagen City Heart Study. RESULTS: A nonlinear effect of alcohol improved the model fit significantly, and the nonlinearity of alcohol was highly significant in both men and women. The relation was concave: HDL-C was stable in men and women who drank more than approximately 35 and 20 drinks per week, respectively. We found a significant nonlinear term of wine on HDL-C in men after adjustment for total alcohol intake. CONCLUSIONS: There was a concave relation between alcohol intake and HDL-C, indicating a threshold effect of alcohol on HDL-C. The association between wine and HDL-C in men after adjusting for total alcohol intake may be due to residual lifestyle confounding.     

Impact of different antidopaminergic mechanisms on the dopaminergic control of prolactin secretion

Antipsychotics are the most common cause of pharmacologically induced hyperprolactinemia. Although this adverse effect was the subject of numerous observations, the mechanisms and promotive factors were not completely investigated yet. Increased awareness of clinical consequences of hyperprolactinemia implicates the necessity for further examinations. The aim of this randomized, single-blinded, placebo-controlled study was to do a systematic examination of the effects of different antidopaminergic mechanisms on prolactin secretion in healthy volunteers. A 7-day intervention was performed with aripiprazole, haloperidol, or reserpine. Prolactin levels changed significantly in the haloperidol (from 177.2 ± 74.6 to 350.7 ± 202.6 mU/L; P < 0.0001) and in the reserpine groups (from 149.6 ± 80.2 to 540.3 ± 280.8 mU/L; P < 0.0001) but not after aripiprazole (from 160.9 ± 65.0 to 189.6 ± 209.6 mU/L; P = 0.69) or placebo (from 211.6 ± 113.4 mU/L to 196.1 ± 85.6 mU/L; P = 0.8). After haloperidol and reserpine, increases in prolactin were significantly more pronounced in women than in men. Furthermore, in women using hormonal contraception, the increase in prolactin was significantly greater than in those without additional estrogen supply. These results demonstrate that the effect of antipsychotic drugs on prolactin levels strongly depends on their mechanism of action. Reserpine, a vesicular monoamine transporter type 2 blocker, causes the most distinct increase. This implies that D? receptor blockade on the lactotrophs is not the sole major cause leading to hyperprolactinemia. The partial agonistic effect of aripiprazole was sufficient to maintain prolactin on physiologic levels. The strong influences of sex and hormonal contraception underline the sensitizing effect of estrogens to the antipsychotic-induced prolactin increase.