Environmental mercury exposure,semen quality and reproductive hormones in Greenlandic Inuit and European men: a cross-sectional study

Several animal studies indicate that mercury is a male reproductive toxicant, but human studies are few and contradictory. We examined semen characteristics and serum levels of reproductive hormones in relation to environmental exposure to mercury. Blood and semen samples were collected from 529 male partners of pregnant women living in Greenland, Poland and Ukraine between May 2002 and February 2004. The median concentration of the total content of mercury in whole blood was 9.2 ng ml⁻¹ in Greenland (0.2–385.8 ng ml⁻¹), 1.0 ng ml⁻¹ in Poland (0.2–6.4 ng ml⁻¹) and 1.0 ng ml⁻¹ in Ukraine (0.2–4.9 ng ml⁻¹). We found a significantly positive association between the blood levels of mercury and serum concentration of inhibin B in men from Greenland (β=0.074, 95% confidence interval (CI)=0.021 to 0.126) and in an analysis including men from all three regions (β=0.067, 95% CI=0.024 to 0.110). The association may be due to beneficial effects of polyunsaturated fatty acids (PUFAs), which are contained in seafood and fish. No significant association (P>0.05) was found between blood concentrations of mercury and any of the other measured semen characteristics (semen volume, total sperm count, sperm concentration, morphology and motility) and reproductive hormones (free androgen index (FAI), follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone and LH×testosterone) in any region. In conclusion, the findings do not provide evidence that environmental mercury exposure in Greenlandic and European men with median whole blood concentration up to 10 ng ml⁻¹ has adverse effects on biomarkers of male reproductive health.     

Weighted Fourier analysis of blood pressure curves after lisinopril versus atenolol administration in young hypertensives

OBJECTIVE: To evaluate and compare the effects of lisinopril versus atenolol administration on the diurnal blood pressure profile and the nocturnal blood pressure fall in young mild-to-moderate essential hypertensives.METHODS: Thirty patients were studied. After a 2-week placebo run-in period, they were single-blind randomly assigned to receive 20 mg lisinopril or 100 mg atenolol. Using a SpaceLabs 90207 device, their ambulatory blood pressure was measured before and after 12 weeks of therapy. The readings were analysed using Fourer series with four harmonics. RESULTS: Lisinopril and atenolol administration significantly decreased office and ambulatory blood pressure values compared with the placebo period. The daily blood pressure curves obtained from Fourier analysis showed that the circadian rhythm was not altered by lisinopril and atenolol administration. From the night:day ratio for the nocturnal blood pressure fall, we found that atenolol administration minimized the average night-time blood pressure dip by increasing the number of non-dippers. In contrast, lisinopril administration did not modify the day-night difference, preserving the nocturnal blood pressure fall. CONCLUSION: Lisinopril and atenolol administration as a first-step treatment of young essential hypertensives produced comparable degrees of diurnal control of arterial pressure. The blood pressure fall at night in patients treated with atenolol was slightly less than that found with lisinopril treatment.     

An effective utilization of MXene and its effect on electromagnetic interference shielding: flexible,free-standing and thermally conductive composite from MXene–PAT–poly(p-aminophenol)–polyaniline co-polymer

MXene and conductive polymers are attractive candidates for electromagnetic interference shielding (EMI) applications. The MXene–PAT-conductive polymer (CP) composites were fabricated by a cost-effective spray coating technique and characterized using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy. A new approach has been developed for the synthesis of exfoliated MXene. The MXene–PAT–poly(p-aminophenol)–polyaniline co-polymer composite exhibited good electric conductivity (EC) of 7.813 S cm⁻¹. The composites revealed an excellent thermal properties, which were 0.687 W (m K)⁻¹ thermal conductivity, 2.247 J (g K)⁻¹ heat capacity, 0.282 mm² s⁻¹ thermal diffusivity and 1.330 W s^1/2 m⁻² K⁻¹ thermal effusivity. The composites showed 99.99% shielding efficiency and the MXene–PAT–PANI–PpAP composite (MXPATPA) had EMI shielding effectiveness of 45.18 dB at 8.2 GHz. The reduced form of MXene (r-Ti₃C₂T_x) increased the shielding effectiveness (SE) by 7.26% and the absorption (SE_A) was greatly enhanced by the ant farm like structure. The composites possess excellent thermal and EMI SE characteristics, thus can be applied in areas, such as mobile phones, military utensils, heat-emitting electronic devices, automobiles and radars.

MXene and conductive polymers are attractive candidates for electromagnetic interference shielding (EMI) applications.     

The use of 7-amino actinomycin D in identifying apoptosis: simplicity of use and broad spectrum of application compared with other techniques

The detection and quantitation of apoptotic cells is becoming increasingly important in the investigation of the role of apoptosis in cellular proliferation and differentiation. The pathogenesis of hematologic disorders such as aplastic anemia and the development of neoplasia are believed to involve dysregulation of apoptosis. To quantitate accurately the proportion of apoptosis cells within different cell types of a heterogeneous cell population such as blood or bone marrow, a method is required that combines the analysis of large numbers of cells with concurrent immunophenotyping of cell surface antigens. In this study, we have evaluated such a method using the fluorescent DNA binding agent, 7-amino actinomycin D (7AAD), to stain three diverse human cell lines, induced to undergo apoptosis by three different stimuli. Flow cytometric analysis defines three populations on the basis of 7AAD fluorescence and forward light scatter. We have shown by cell sorting and subsequent morphological assessment and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling that the populations defined by 7AAD represent live, apoptotic, and late-apoptotic/dead cells. This method is quick, simple, reproducible, and cheap and will be a valuable tool in the investigation of the role of apoptosis in normal physiology and in disease states.     

Optimal management strategies for placenta accreta

Objective  To determine which interventions for managing placenta accreta were associated with reduced maternal morbidity.
Design  Retrospective cohort study.
Setting  Two tertiary care teaching hospitals in Utah.
Population  All identified cases of placenta accreta from 1996 to 2008.
Methods  Cases of placenta accreta were identified using standard ICD-9 codes for placenta accreta, placenta praevia, and caesarean hysterectomy. Medical records were then abstracted for maternal medical history, hospital course, and maternal and neonatal outcomes. Maternal and neonatal complications were compared according to antenatal suspicion of accreta, indications for delivery, preoperative preparation, attempts at placental removal before hysterectomy, and hypogastric artery ligation.
Main outcome measures  Early morbidity (prolonged maternal intensive care unit admission, large volume of blood transfusion, coagulopathy, ureteral injury, or early re-operation) and late morbidity (intra-abdominal infection, hospital re-admission, or need for delayed re-operation).
Results  Seventy-six cases of placenta accreta were identified. When accreta was suspected, scheduled caesarean hysterectomy without attempting placental removal was associated with a significantly reduced rate of early morbidity compared with cases in which placental removal was attempted (67 versus 36%, P = 0.038). Women with preoperative bilateral ureteric stents had a lower incidence of early morbidity compared with women without stents (18 versus 55%, P = 0.018). Hypogastric artery ligation did not reduce maternal morbidity.
Conclusions  Scheduled caesarean hysterectomy with preoperative ureteric stent placement and avoiding attempted placental removal are associated with reduced maternal morbidity in women with suspected placenta accreta.     

Urinary C-peptide creatinine ratio to detect absolute insulin deficiency in type 2 diabetes

BackgroundNational Institute for Health and Clinical Excellence guidelines (CG87) recommend neutral protamine hagedorn (NPH) insulin for the provision of basal insulin in type 2 diabetes, but use of analogue insulin is as much as 40%. Where residual endogenous insulin secretory capacity is present there is no evidence that analogue insulins provide any additional benefit over human insulins, and they come at an expensive premium. Anecdotally, however, there is a reluctance to switch people back to NPH insulin, partly because of a perceived risk of pancreatic failure and potential ketosis. Urinary C-peptide creatinine ratio (UCPCR) has been validated as a method for evaluating residual endogenous insulin secretion in type 1 and type 2 diabetes, with a UCPCR of no more than 0·2 nmol/mmol suggestive of absolute insulin deficiency. We aimed to evaluate the prevalence of true insulin deficiency among patients with type 2 diabetes with UCPCR, and confirm findings with the gold standard mixed meal tolerance test (MMTT).Methods191 insulin-treated patients with a clinical diagnosis of type 2 diabetes (diagnosed at or after age 45 years and who did not start insulin within the first year of diagnosis) collected a 2-h post-prandial urine sample for UCPCR measurement. Nine patients from two subgroups (UCPCR ≤0·2 nmol/mmol and UCPCR >0·2) completed a standard MMTT.Findings11 (5·8%) of 191 patients had two consistent UCPCRs of less than or equal to 0·2 nmol/mmol. Nine were able to do the MMTT, of whom five were confirmed to have absolute insulin deficiency (stimulated serum c-peptide <0·2 nmol/L). Three of these five patients were glutamic acid decarboxylase antibody-negative. Nine of nine patients with UCPCR of more than 0·2 nmol/L had confirmed endogenous insulin secretion in their MMTT. Those with insulin deficiency had a shorter time to starting insulin (median 2·5 years [IQR 1·5–3·0] vs 6·0 [3·0–10·75], p=0·005) and lower body-mass index (25 kg/m² vs 29, p=0·04) but no other significant differences in clinical characteristics.InterpretationWe have demonstrated a very low prevalence of true pancreatic failure in this population of insulin-treated patients with type 2 diabetes. This requires further exploration by comparison of a population being treated with NPH insulin with one on analogue insulin, and then determining whether UCPCR could act as a clinical decision support tool to safely switch from analogue insulin to NPH insulin.FundingNational Institute for Health Research.