The genetic architecture of mitochondrial dysfunction in Parkinson's disease.

Mitochondrial impairment is a well-established pathological pathway implicated in Parkinson's disease (PD). Defects of the complex I of the mitochondrial respiratory chain have been found in post-mortem brains from sporadic PD patients. Furthermore, several disease-related genes are linked to mitochondrial pathways, such as PRKN, PINK1, DJ-1 and HTRA2 and are associated with mitochondrial impairment. This phenotype can be caused by the dysfunction of mitochondrial quality control machinery at different levels: molecular, organellar or cellular. Mitochondrial unfolded protein response represents the molecular level and implicates various chaperones and proteases. If the molecular level of quality control is not sufficient, the organellar level is required and involves mitophagy and mitochondrial-derived vesicles to sequester whole dysfunctional organelle or parts of it. Only when the impairment is too severe, does it lead to cell death via apoptosis, which defines the cellular level of quality control. Here, we review how currently known PD-linked genetic variants interfere with different levels of mitochondrial quality control. We discuss the graded risk concept of the most recently identified PARK loci (PARK 17-23) and some susceptibility variants in GBA, LRRK2 and SNCA. Finally, the emerging concept of rare genetic variants in candidates genes for PD, such as HSPA9, TRAP1 and RHOT1, complete the picture of the complex genetic architecture of PD that will direct future precision medicine approaches.

Use of non-prescription analgesics and male reproductive function.

We studied the association between intake of non-prescription analgesics and semen quality and male reproductive hormone levels in a cross-sectional study among 1493 men. The men provided one semen (n=1493) and blood sample (n=1056) and filled in questionnaires on use of non-prescription analgesics (paracetamol, NSAIDs and combination drugs (yes/no)). Adjusting for age, study and other covariates, we observed no association between intake of non-prescription analgesics and markers of semen quality. Adjusting for age and time of day of blood sampling, users of non-prescription analgesics had a 10.4% (95% confidence interval (CI) 4.0-17.1%) higher testosterone level than non-users. When we stratified by medication type, the association between analgesics and higher testosterone was observed between users of non-steroidal anti-inflammatory drugs (NSAIDs) and combination drugs but not paracetamol. This study suggests that use of non-prescription analgesics is associated with slightly higher serum testosterone levels than non-use.

Exercise gaming - a motivational approach for older adults with vestibular dysfunction.

Purpose The purpose of the study was to identify possible reasons for a modest level of exercise compliance during computer-assisted training for vestibular rehabilitation. Method Qualitative design and analysis of 14 semi-structured interviews with seven participants before and after a period with computer-assisted home training. The interviews evolved around themes, such as the elderly participants' self-efficacy, motivation and acceptance of the technology. Results Age was not an excuse for the modest exercise compliance. The participants were basically self-efficient and accepted the technology, but their knowledge and understanding of the training programme were insufficient. The participants asked for a greater variation in the exercises and asked for closer contact with the physiotherapist. When Mitii is used for vestibular rehabilitation, the system has some limitations. Conclusions The modest level of exercise compliance can be explained by (1) missing variety of exercise speed and duration and lack of introducing new exercises, (2) insufficient interaction with the physiotherapist regarding the participants' performance and lack of social contact with other patients and (3) desire for a deeper understanding of the training programme with supplying information on the parts of the vestibular system addressed by the training. Implications for Rehabilitation Computer-assisted technologies should generate feedback on the quality of user performance and inform the patient of the relevance of the exercise. The technology should support social contact among patients with the same diagnosis and establish contact with the physiotherapist at the hospital advice and feedback. Varity and adjustments to exercises are necessary to maintain motivation and exercise compliance.

The influence of type 2 diabetes on fibrin clot properties in patients with coronary artery disease.

Type 2 diabetes mellitus (T2DM) increases the risk of coronary thrombosis and both conditions are associated with altered fibrin clot properties. However, the influence of T2DM on fibrin clot properties in patients with coronary artery disease (CAD) remains unclear. We aimed to investigate the influence of T2DM on fibrin clot properties in patients with CAD. Fibrin clot structure and fibrinolysis were investigated in 581 CAD patients (148 with T2DM) using turbidimetric assays, confocal and scanning electron microscopy. Clots made from plasma and plasma-purified fibrinogen were studied, and plasma levels of inflammatory markers were analysed. T2DM patients had increased clot maximum absorbance compared with non-diabetic patients (0.36 ± 0.1 vs 0.33 ± 0.1 au; p=0.01), displayed longer lysis time (804 [618;1002] vs 750 [624;906] seconds; p=0.03) and showed more compact fibrin structure assessed by confocal and electron microscopy. Fibrinogen levels were elevated in T2DM (p< 0.001), but clots made from purified fibrinogen showed no differences in fibrin properties in the two populations. Adjusting for fibrinogen levels, T2DM was associated with C-reactive protein and complement C3 plasma levels, with the former correlating with clot maximum absorbance (r=0.24, p< 0.0001) and the latter with lysis time (r=0.30, p< 0.0001). Independent of fibrinogen levels, females had more compact clots with prolonged lysis time compared with males (all p-values< 0.001). In conclusion, T2DM is associated with prothrombotic changes in fibrin clot properties in patients with CAD. This is related to quantitative rather than qualitative changes in fibrinogen with a possible role for inflammatory proteins.

Reduced antiplatelet effect of aspirin is associated with low-grade inflammation in patients with coronary artery disease.

Inflammation has been proposed to modify platelet function. This may lead to increased platelet reactivity and reduced antiplatelet drug efficacy in patients with coronary artery disease (CAD). However, this hypothesis has not been investigated in stable CAD patients receiving aspirin as mono antiplatelet therapy. It was the objective of this study to investigate the association between platelet reactivity, the inflammatory markers high-sensitive C-reactive protein (hs-CRP) and interleukin-6 (IL-6), and platelet activation. We performed a cross-sectional study on 524 stable high-risk CAD patients. Among these, 91% had a history of myocardial infarction, 23% had type 2 diabetes, and 13% had both. All patients received 75 mg aspirin daily as mono antiplatelet therapy. Platelet reactivity was assessed by multiple electrode aggregometry (Multiplate®, MEA) and VerifyNow®. Inflammation was evaluated by hs-CRP and IL-6. Platelet activation was assessed by soluble P-selectin (sP-selectin), and cyclooxygenase-1 inhibition was evaluated by measurement of serum thromboxane B2. Hs-CRP levels were significantly higher in upper platelet reactivity tertile patients than in lower platelet reactivity tertile patients (p≤0.02). Similar results were obtained with IL-6, though not statististically significant (p≥0.15). Platelet activation evaluated by sP-selectin was significantly higher in patients with MEA reactivity levels in the upper tertile than in the lower tertile (p=0.0001). Optimal compliance was confirmed by low serum thromboxane B2 levels in all patients. In conclusion, increased levels of hs-CRP were associated with augmented platelet reactivity in stable high-risk CAD patients receiving aspirin as mono antiplatelet therapy. These findings may suggest that chronic low-grade inflammation reduce the antiplatelet effect of aspirin.

Men with cancer change their health behaviour: a prospective study from the Danish diet, cancer and health study.

BACKGROUND: Health behaviour changes may improve the quality of life and survival among cancer survivors. We prospectively examined changes in health behaviour among and between men with prostate cancer (PC), men with cancers other than PC and cancer-free men. METHODS: We analysed data for 20 914 men (50-65 years), 426 with cancer, and 20 488 persons who were cancer-free between baseline (1993-1997) and follow-up (2000-2002) in multiple linear regression models to determine differences in changes in body mass index (BMI) and in alcohol and tobacco consumption. RESULTS: Body mass index and tobacco and alcohol consumption decreased significantly (P<0.001) between baseline and follow-up among both men with cancer and cancer-free men. Men with cancers other than PC significantly decreased their BMI (ß=-058; 95% confidence interval (CI): -0.77, -0.40) and tobacco consumption (ß=-1.36; 95% CI: -2.22, -0.49) compared with cancer-free men and were significantly more likely to quit smoking and lose weight. CONCLUSION: Men with cancers other than PC decreased their tobacco consumption and BMI significantly more than cancer-free men. Men with cancer do change their health behaviour; clinicians should take this into account in planning follow-up care for cancer survivors.

Adenomyosis and junctional zone changes in patients with endometriosis.

OBJECTIVES: To evaluate image findings in the junctional zone (JZ) in patients with endometriosis and correlate with image findings of adenomyosis. To attempt a correlation of the degree of adenomyotic infiltration with the degree of infiltration and stage of endometriosis. STUDY DESIGN: Magnetic resonance imaging (MRI) of the uterus was performed in 153 women with suspected deeply infiltrating endometriosis and planned surgery, and in a reference group of 129 women without endometriosis, verified during hysterectomy. Changes in the JZ and endometriosis in the pelvis were described in detail. Diagnosis of adenomyosis at MRI was based on optimal criteria derived from the hysterectomy control group. The stage of endometriosis (AFS stage) was determined during surgery. RESULTS: In the group of women with endometriosis 34.6% had adenomyosis compared with 19.4% in the reference group (p<0.05). More women with endometriosis (39.9%) had an irregular JZ compared to 22.5% in the reference group (p<0.01). Among women with severe endometriosis (AFS stage IV) 42.8% had adenomyosis compared to 29.4% in the women with other stages of endometriosis (AFS stages I+II+III) (p=0.10). More women with severe endometriosis (AFS stage IV) had deeper wall invasion of adenomyosis (p>0.05) but the presence of deep infiltrative rectovaginal endometriosis and the size of infiltration were not correlated to adenomyosis or depth of infiltration of adenomyosis. CONCLUSIONS: In a group of young women with severe symptomatic endometriosis and planned surgery a systematic evaluation of the JZ revealed that one third had uterine adenomyosis, but the invasive potential of endometrial cells in the uterus and in the peritoneum corresponded only to a limited degree.

Effect of platelet turnover on whole blood platelet aggregation in patients with coronary artery disease.

BACKGROUND: Previous studies have demonstrated considerable variation in the antiplatelet effect of aspirin. OBJECTIVES: To investigate the impact of platelet turnover on the antiplatelet effect of aspirin in patients with stable coronary artery disease (CAD) and to identify determinants of platelet turnover. METHODS: Platelet turnover was evaluated by measurements of immature platelets and thrombopoietin in 177 stable CAD patients on aspirin monotherapy, including 85 type 2 diabetics and 92 non-diabetics. Whole blood platelet aggregation was determined using the VerifyNow(®) Aspirin test and multiple electrode aggregometry (MEA, Multiplate(®) ) induced by arachidonic acid (AA) (1.0 mm), adenosine diphosphate (ADP) (10 µm) and collagen (1.0 µg mL(-1) ). RESULTS: Immature platelet levels significantly correlated with MEA (r = 0.31-0.36, P-values < 0.0001) and the platelet activation marker sP-selectin (r = 0.19, P = 0.014). Contrary to the VerifyNow(®) test, MEA significantly correlated with variations in platelet count (r = 0.45-0.68, P-values < 0.0001). Among patients with residual platelet reactivity according to AA, there were significantly more diabetics (61% vs. 41%, P = 0.027) and higher levels of sP-selectin (77.7 ± 29 vs. 70.2 ± 25 ng mL(-1) , P = 0.070) and serum thromboxane B(2) (0.81 [0.46; 1.70] vs. 0.56 [0.31; 1.12] ng mL(-1) , P = 0.034). In a multivariate regression analysis, immature platelet levels were determined by thrombopoietin levels (P < 0.001), smoking (P = 0.020) and type 2 diabetes (P = 0.042). CONCLUSIONS: The antiplatelet effect of aspirin was reduced in CAD patients with an increased platelet turnover. Once-daily dosing of aspirin might not suffice to adequately inhibit platelet aggregation in patients with an increased platelet turnover.

Reduced platelet response to aspirin in patients with coronary artery disease and type 2 diabetes mellitus.

INTRODUCTION: Diabetes mellitus is complicated by accelerated atherosclerosis, resulting in an increased risk of coronary artery disease (CAD) and thrombosis. Despite the proven benefits of aspirin, previous studies indicate a reduced cardiovascular protection from aspirin in diabetic patients. We aimed to investigate whether diabetes mellitus influenced the platelet response to aspirin in patients with CAD. MATERIALS AND METHODS: Platelet aggregation and activation were evaluated during aspirin treatment in 85 diabetic and 92 non-diabetic patients with CAD. Adherence to aspirin was carefully controlled. All patients had CAD verified by coronary angiography and were taking 75 mg non-enteric coated aspirin daily. RESULTS: Diabetic patients showed significantly higher levels of platelet aggregation compared to non-diabetic patients evaluated by VerifyNow® Aspirin (p=0.03) and Multiplate® aggregometry using arachidonic acid (AA) 0.5 mM (p=0.005) and 1.0 mM (p=0.009). In addition, platelet activation determined by soluble P-selectin was significantly higher in diabetics compared to non-diabetics (p=0.005). The higher AA-induced aggregation was associated with higher levels of HbA(1c). Compliance was confirmed by low levels of serum thromboxane B(2) (below 7.2 ng/mL). Diabetics had significantly higher levels of serum thromboxane B(2) (p<0.0001). CONCLUSIONS: Diabetic patients with CAD had significantly higher levels of both platelet aggregation and activation compared to non-diabetic patients with CAD despite treatment with the same dosage of aspirin. These findings may partly explain the reduced cardiovascular protection from aspirin in diabetic patients.

Human semen quality in relation to dietary pesticide exposure and organic diet.

The objective of the study was to corroborate or refute the hypothesis that farmers having a high intake of organic grown commodities have a high semen quality due to their expected lower level of dietary pesticides intake. Food frequency data and semen were collected from 256 farmers (171 traditional farmers and 85 organic farmers, overall participation rate: 32%) who were selected from central registers. Each farmer delivered one semen sample before the spraying season started. The farmers were divided into three groups where the commodities from organic production contributed no (N, 0%), medium (M, 1-49%), or a high (H, 50-100%) proportion of the fruit and vegetables consumed. Farmers having a high relative intake of organically grown fruit and vegetables also had a high relative consumption of organically produced meat, milk, and bread, and differences were observed comparing the actual mean intake of single commodities, such as rice, potato, and pork meat. The current individual dietary intake of 40 pesticides was estimated using food frequencies and generalized serving size data in combination with data on pesticide concentrations in food commodities as obtained from the National Danish Food Monitoring Program. The estimated pesticide intake was significantly lower among farmers of group H, but for all three groups of farmers the average dietary intake of 40 pesticides was at or below 1% of the acceptable daily intake (ADI) except for the dithiocarbamates (max = 0.21 microg/kg day = 2.2% ADI), methidathion, (max = 0.01 microg/kg day = 1.4% ADI), and 2-phenylphenol (max = 0.21 microg/kg day = 1.1% ADI). The median sperm concentration for the three groups of farmers was not significantly different (p = 0.40, median sperm concentration was N = 62, M = 44, and H = 75 million/ml). The group of men without organic food intake had a significant lower proportion of morphologically normal spermatozoa, but in relation to 14 other semen parameters no significant differences were found between the groups. Intake of 40 individual pesticides was correlated with four semen parameters (concentration, percentage dead spermatozoa, percentage normal sperm heads, and motility [VCL]). Five significant correlations (p value 0.01) were found among the 160 comparisons in relation to percentage dead spermatozoa: azinphos-methyl, carbaryl, chlorfenson, fenitrothion, and tetradifon. For all of them a lower percentage of dead spermatozoa were found in the groups with a high dietary intake of the specific pesticide. In contrast, for all pesticides evaluated only minor differences were found between the groups when considering spermatozoa concentration, morphology, and motility. In conclusion, the estimated dietary intake of 40 pesticides did not entail a risk of impaired semen quality, but precautions should be taken when generalizing this negative result to populations with a higher dietary exposure level or an intake of other groups of pesticides.

Aneuploidy in sperm and exposure to fungicides and lifestyle factors. ASCLEPIOS. A European Concerted Action on Occupational Hazards to Male Reproductive Capability.

Fungicides include chemicals that are known aneugens. The purpose of the present study was to investigate whether occupational exposure to these and other agricultural pesticides induces aneuploidy in human sperm. The contribution of lifestyle factors (smoking and alcohol consumption) to the frequency of aneuploid sperm was evaluated as well. The effects of age and sperm concentration were analyzed as confounders. Spermatozoa from 30 healthy farmers were studied before and after exposure to fungicides, using fluorescence in situ hybridization (FISH). Ten thousand spermatozoa were scored per semen sample to determine the disomy and diploidy frequencies for chromosomes 1 and 7. Exposure to fungicides was not associated with sperm aneuploidy. Smoking was significantly associated with sperm carrying an extra chromosome 1 and with diploid sperm as well as with the aggregate frequency of aneuploid sperm. Alcohol consumption, sperm concentration, and age showed inconsistent results before and after the season of exposure to fungicides. For low-level exposures, such as occupational exposures, the sensitivity of the sperm-FISH method may not be sufficient. The present study supports earlier ones showing that smoking can increase aneuploidy in human sperm.

Semen quality and sex hormones among organic and traditional Danish farmers. ASCLEPIOS Study Group.

OBJECTIVES: To confirm or refute the hypothesis that organic farmers have higher sperm concentrations than traditional farmers. METHODS: Traditional and organic farmers were selected randomly from central registers, and 171 traditional farmers and 85 organic farmers delivered one semen sample before the start of the spraying season. The participation rate was 28.8% among traditional farmers and 42.9% among organic farmers. RESULTS: The median sperm concentration for traditional and organic farmers was 58 million/ml and 64 million/ml, respectively. After adjustment for several confounders, sperm concentration, total count, proportion of non-vital spermatozoa, sperm chromatin structure, and motility variables did not differ significantly between the two groups. The traditional farmers had a significantly lower proportion of normal spermatozoa, but this result was not confirmed in a second sample. Organic farmers had slightly higher inhibin B concentration and testosterone/sex hormone binding globulin ratio. CONCLUSION: Despite slight differences in concentrations of reproductive hormones, no significant differences in conventional measures of semen quality were found between organic and traditional farmers.

Change in semen quality and sperm chromatin structure following occupational styrene exposure. ASCLEPIOS.

OBJECTIVES: Organic solvents have been suspected to exert detrimental effects on human spermiogenesis. Styrene, which is both mutagenic and neurotoxic, was selected as a suitable organic solvent for further assessment of a possible effect on semen quality and sperm DNA damage. SUBJECTS AND METHODS: Semen samples were collected from 23 reinforced plastics workers at the time of employment and after 6 months of styrene exposure and from 21 nonexposed farmers. Intra-individual changes in conventional semen parameters and sperm-DNA denaturation patterns were related to the internal dose of styrene exposure as measured by postshift urinary mandelic acid. RESULTS: A statistically significant decline in sperm density was seen during styrene exposure from 63.5 to 46.0 million sperm/ml, whereas no decline was seen in the nonexposed subjects. The total sperm count was almost halved from an initial value of 175 million sperm/ejaculate. However, no relationship was apparent when the sperm parameters were related to internal levels of exposure. However, an exposure-response relationship was shown for DNA-denaturation patterns, but the numbers were small. CONCLUSION: A declining sperm count following styrene exposure is suggested. However, the findings of the internal and external comparisons are inconsistent, and this may be due to the high intraindividual variability of semen parameters and the limited study size but may also be attributable to a weak internal exposure gradient. Spermatogenesis may be vulnerable to styrene exposure. However, due to the small numbers these findings are only preliminary.

Effects of pesticide exposure on time to pregnancy: results of a multicenter study in France and Denmark. ASCLEPIOS Study Group.

The aim of this study was to determine whether there was a relation between male exposure to pesticides and the amount of time needed to conceive (time to pregnancy) for farmers and agricultural workers in France and Denmark. The authors used retrospective studies to compare the time to pregnancy of couples in which the man was exposed to pesticides during the year before the birth of their youngest child with that of couples in which the man was not exposed. In 1995 and 1996, the authors studied 362 French rural workers (142 exposed to pesticides and 220 not exposed), 449 Danish farmers (326 conventional farmers exposed to pesticides and 123 nonexposed organic farmers), and 121 Danish greenhouse workers exposed to pesticides. The fecundability ratio for exposure to pesticides (Cox model, before and after adjustment for confounding factors) did not differ from 1 in any of the three populations. In France, the adjusted fecundability ratio was 1.17 (95% confidence interval (CI) 0.89-1.55) for exposed and nonexposed agricultural workers. In Denmark, it was 1.09 (95% CI 0.82-1.43) for exposed and nonexposed farmers and 0.83 (95% CI 0.69-1.18) for greenhouse workers and nonexposed farmers. Thus, this study found no relation between fertility (time to pregnancy) and male exposure to pesticides.

Environmental semen studies--is infertility increased by a decline in sperm count?

The objective of the studies was to evaluate infertility according to sperm count shifts. The distribution of the sperm count of 1024 Danish men (median 56 million/ml) served as reference. The data were transformed with multiplicative or additive models to create alternative distributions with median sperm count values changed by 25-100%. Sperm-count-specific fecundabilities were provided from a follow-up of first-pregnancy planners in a Danish population. The estimated average fecundability of the 1024 Danish men was 16.9% [95% confidence interval (95% CI) 16.7-17.2], and the proportion of cohabiting men with spouses pregnant within 1 year was 86.0% (95% CI 84.1-87.8). Simulations of alternative sperm count distributions indicated that the relationship between sperm count shift and fertility strongly depends on the median level of the sperm count at onset and the type of shift, a dramatic decline from a high level in a multiplicative model indicating a marginal change and a minor decline from a low level in an additive model representing a strong decrease in fertility. In some cases sperm count, therefore, may be an early warning of changes in fertility.

[Pesticides and time to pregnancy among Danish farmers]. / Pesticider og ventetid til graviditet hos danske landmaend. ASCLEPIOS Study Group.

The aim of this study was to examine time to pregnancy among farmers who used pesticides (traditional farmers) and farmers who did not (organic farmers). A total of 904 men, selected from the Danish Ministry of Agriculture lists of traditional and organic farmers, participated in telephone interviews. The participation rate was 84%. Information was collected on "time to pregnancy" for the youngest child, exposure to pesticides and potential confounders. Using the discrete analogue of the Cox Regression Model (including potential confounders: male and female smoking, female age, parity and contraceptive method), the fecundability ratio between traditional farmers using pesticides and organic farmers was 1.03 (95% CI: 0.75-1.40). In the group of farmers who sprayed with pesticides, none of the characteristics related to the use of pesticides could account for the variation in time to pregnancy. No overall effect of pesticides on male fecundability could be demonstrated in this retrospective study among Danish farmers.