What is the effectiveness of surgical and non-surgical therapies in the treatment of ischemic priapism in patients with sickle cell disease? A systematic review by the EAU Sexual and Reproductive Health Guidelines Panel

Sickle cell disease (SCD) is an inherited hemoglobin disorder characterized by the occlusion of small blood vessels by sickle-shaped red blood cells. SCD is associated with a number of complications, including ischemic priapism. While SCD accounts for at least one-third of all priapism cases, no definitive treatment strategy has been established to specifically treat patients with SC priapism. The aim of this systematic review was to assess the efficacy and safety of contemporary treatment modalities for acute and stuttering ischemic priapism associated with SCD. The primary outcome measures were defined as resolution of acute priapism (detumescence) and complete response of stuttering priapism, while the primary harm outcome was as sexual dysfunction. The protocol for the review has been registered (PROSPERO Nr: CRD42020182001), and a systematic search of Medline, Embase, and Cochrane controlled trials databases was performed. Three trials with 41 observational studies met the criteria for inclusion in this review. None of the trials assessed detumescence, as a primary outcome. All of the trials reported a complete response of stuttering priapism; however, the certainty of the evidence was low. It is clear that assessing the effectiveness of specific interventions for priapism in SCD, well-designed, adequately-powered, multicenter trials are strongly required.

Design and characterization of an electromagnetic probe for distinguishing morphological differences in soft tissues

We present a method for designing and optimizing an in-house designed electromagnetic probe for distinguishing morphological differences in biological tissues. The probe comprises concentric multi-wound coils, the inner being the primary coil and the outer being the detector coil. A time-varying voltage is imposed on the primary coil, resulting in an induced current in the detector coil. For highly conductive samples, eddy currents are induced in the sample and inductively couple with the electromagnetic probe. However, in weakly conducting samples, the primary coupling mechanism is found to be capacitive though there can be a non-negligible inductive component. Both the mutual inductive coupling and the capacitive coupling between the sample and the probe are detected as a change in the induced voltage of the detector coil using lock-in detection. The induced voltage in the detector coil is influenced more by the morphological structure of the specimen rather than by changes in electrical conductivity within different regions of the sample. The instrument response of the lock-in amplifier is also examined with simulated input voltage signals to relate its output to specific changes in inductive and capacitive coupling, in order to relate sample characteristics to a single voltage output. A circuit element model is used to interpret the experimental measurements. It is found that the sensitivity of the measurement for a given set of probe characteristics (resistances, inductances, and capacitances) can be optimized by adding a small amount of capacitance in the external circuit in parallel with the detector coil. Illustrative measurements are presented on animal (porcine and bovine) tissue and on human liver tissue containing a metastatic tumor to demonstrate the capabilities of the probe and measurement method in distinguishing different tissue types despite having similar electrical conductivities. Since biological tissues are multi-scale, heterogeneous materials comprising regions of differing conductivity, permittivity, and morphological structure, the electromagnetic method presented here has the potential to examine structural variations in tissue undergoing physical changes due to healing or disease.

A new 2% testosterone gel formulation: a comparison with currently available topical preparations

Testosterone gel formulations have become a popular testosterone replacement therapy in patients with hypogonadism since their advent in the year 2000. The gel formulations restore testosterone levels to mid-normal physiological levels (14-17.5 nmol/L) as early as within 24 h, and help alleviate the signs and symptoms of testosterone deficiency, thereby leading to an improved quality of life. Although testosterone gels have a favourable efficacy and safety profile as compared to injectable and patch formulations, risk of secondary exposure poses a challenge. Approved testosterone topical formulations include Tostrex^® (Tostran^® , Fortesta^® ), Androgel^® (Testogel^® ), Testim^® and Axiron^® (solution), which have a favourable efficacy profile and positively impacted patient-reported outcome(s). Besides, Testavan, which is a 2% testosterone gel, is under registration in Europe and already approved in Australia in May 2017. Testavan uses a novel hydroalcoholic and highly viscous topical formulation. This product comes with a metered dose dispenser and a cap applicator that allows a hands-free application for precise dispensing and application. The present article provides a comprehensive review of pharmacokinetic, tolerability and safety profile of the testosterone gels available in the market along with the new 2% testosterone gel, Testavan.

Revascularization with percutaneous coronary intervention does not affect androgen status in males with chronic stable angina pectoris

There is a clear association between low serum testosterone and coronary artery disease (CAD) in men. Hypotestosteronaemia is associated with accelerated atherosclerosis and a quarter of men with CAD are biochemically hypogonadal. Amongst those with CAD, hypotestosteronaemia is associated with increased mortality. Testosterone vasodilates coronary arteries, and exogenous testosterone reduces ischaemia. Whether hypotestosteronaemia is a cause or a consequence of CAD remains unanswered. The aim of this prospective observational study was to investigate whether coronary revascularization affected androgen status in men with stable angina pectoris. Twenty five men (mean age 62.7, SD 9.18) with angiographically significant CAD and symptomatic angina underwent full coronary revascularization by percutaneous coronary intervention. Androgen status and symptoms of angina, stress, depression and sexual function were assessed before, and at one and 6 months after the coronary revascularization. All patients underwent complete revascularization which was associated with a significant reduction in angina symptoms and ischaemia. No significant difference was seen in total testosterone (11.33 nmol/L baseline; 12.56, 1 month post; 13.04 at 6 months; p = 0.08). A significant and sustained rise in sex hormone-binding globulin was seen (33.99 nm/L baseline; 36.11 nm/L 1 month post PCI; 37.94 nm/L at 6 months; p = 0.03) Overall, there was no significant alteration in any other marker of androgen status including free testosterone or bioavailable testosterone. There was no change in symptoms of anxiety, depression or sexual function. Coronary revascularization has no sustained effect on androgen status. This supports the hypothesis that hypotestosteronaemia is not a consequence of angina pectoris or myocardial ischaemia.

Testosterone and obesity

Testosterone is a key hormone in the pathology of metabolic diseases such as obesity. Low testosterone levels are associated with increased fat mass (particularly central adiposity) and reduced lean mass in males. These morphological features are linked to metabolic dysfunction, and testosterone deficiency is associated with energy imbalance, impaired glucose control, reduced insulin sensitivity and dyslipidaemia. A bidirectional relationship between testosterone and obesity underpins this association indicated by the hypogonadal-obesity cycle and evidence weight loss can lead to increased testosterone levels. Androgenic effects on enzymatic pathways of fatty acid metabolism, glucose control and energy utilization are apparent and often tissue specific with differential effects noted in different regional fat depots, muscle and liver to potentially explain the mechanisms of testosterone action. Testosterone replacement therapy demonstrates beneficial effects on measures of obesity that are partially explained by both direct metabolic actions on adipose and muscle and also potentially by increasing motivation, vigour and energy allowing obese individuals to engage in more active lifestyles. The degree of these beneficial effects may be dependent on the treatment modality with longer term administration often achieving greater improvements. Testosterone replacement may therefore potentially be an effective adjunctive treatment for weight management in obese men with concomitant hypogonadism.

Testosterone deficiency and severity of erectile dysfunction are independently associated with reduced quality of life in men with type 2 diabetes

Erectile dysfunction (ED) and low testosterone levels are common in men with type 2 diabetes (T2D). We have investigated the impact of testosterone on quality of life (QoL) in diabetic men with ED. Men with ED were identified within a study cohort of 355 men with T2D. All subjects completed SF-36 health and Androgen Deficiency of the Aging Male questionnaires. Total tesosterone (TT), bioavailable testosterone (BT) and sex hormone-binding globulin levels of study participants were measured and free testosterone levels were calculated (cFT). A subgroup of 126 ED patients completed the International Index of Erectile Function-5 (IIEF-5) questionnaire. Linear regression analyses were corrected for age, body mass index (BMI), glycosylated haemoglobin (HbA1c), smoking, alcohol consumption and cardiovascular disease (CVD). Total SF-36 scores significantly and positively correlated with TT levels (r = 0.219, p = 0.001), BT levels (r = 0.199, p = 0.004) and cFT levels (r = 0.185, p = 0.007) among men with ED. These trends were strengthened after adjusting for age, BMI, HbA1c, smoking, alcohol consumption and CVD (TT r = 0.359, p = 0.015; BT r = 0.354, p = 0.024 and cFT r = 0.354, p = 0.024). IIEF-5 scores significantly correlated inversely with TT (r = 0.546, p = 0.001), BT (r = 0.506, p = 0.004) and cFT levels (r = 0.532, p = 0.001). A positive linear relationship was observed between IIEF-5 scores and total SF-36 score (r = 0.491, p = 0.003). Patients who reported having ED had an average SF-36 score of 9.1% less than those without ED (p < 0.001). Lower testosterone and greater severity of ED independently correlated with poorer physical function, social function, vitality and decline in general health domains of the SF-36. This is the first study to report that testosterone deficiency and severity of ED are both independently associated with reduced QoL in men with T2D. Furthermore, ED and low testosterone are markers of poor health which impact on an individual's self-perception of their health status.

The role of androgen receptor CAG repeat polymorphism and other factors which affect the clinical response to testosterone replacement in metabolic syndrome and type 2 diabetes: TIMES2 sub-study

CONTEXT

The TIMES2 (testosterone replacement in hypogonadal men with either metabolic syndrome or type 2 diabetes) study reported beneficial effects of testosterone replacement therapy (TRT) on insulin resistance and other variables in men with diabetes or metabolic syndrome. The androgen receptor CAG repeat polymorphism (AR CAG) is known to affect stimulated AR activity and has been linked to various clinically relevant variables.

OBJECTIVE

To assess the role of AR CAG in the alteration of clinical response to TRT in the TIMES2 study.

DESIGN

Subgroup analysis from a multicentre, randomised, double-blind, placebo-controlled and parallel group study.

SETTING

Outpatient study recruiting from secondary and primary care.

PATIENTS

A total of 139 men with hypogonadism and type 2 diabetes or metabolic syndrome, of which 73 received testosterone during the TIMES2 study.

INTERVENTION

Testosterone 2% transdermal gel vs placebo.

MAIN OUTCOME MEASURE

Regression coefficient of AR CAG from linear regression models for each variable.

RESULTS

AR CAG was independently positively associated with change in fasting insulin, triglycerides and diastolic blood pressure during TRT with a trend to association with HOMA-IR - the primary outcome variable. There was a trend to negative association between AR CAG and change in PSA. There was no association of AR CAG with change in other glycaemic variables, other lipid variables or obesity.

CONCLUSION

AR CAG affected the response of some variables to TRT in the TIMES2 study, although the association with HOMA-IR did not reach significance. Various factors may have limited the power of our study to detect the significant associations between AR CAG, testosterone levels and change in variables with testosterone treatment. Analysis of similar data sets from other clinical trials is warranted.

Defensive adaptations of eggs and adults ofGastrophysa cyanea (Coleoptera: Chrysomelidae)

Egg clusters and adults ofGastrophysa cyanea are conspicuous and, like their larvae, are chemically protected. The eggs owe their bright yellow color primarily to β-carotene and, in addition, contain substantial quantities of oleic acid. At natural concentrations oleic acid effectively deters many species of ants from feeding. The use of fatty acids as deterrents against ants is discussed as a possible widespread phenomenon among insects. During defensive confrontations, adults ofG. cyanea exhibit avoidance behavior and may also feign death. In addition, the adults may autohemmorhage or secrete a fluid from elytral or pronotal pores in response to traumatic stimuli. The secretions are effective against ants and contain a mixture of hydrocarbons as well as terpenoid components. The pattern of ontogenetic modification in the defensive chemical repertoire ofG. cyanea is discussed.

Venom chemistry of ants in the genusMonomorium

A comparative analysis of the venomous alkaloids produced by ant species in the subgenusMonomorium of the genusMonomorium has been undertaken. All species produce mixtures of unsymmetricaltrans-2,5-dialkylpyrrolidines, but the proportions of the constituents may vary considerably between species. All alkaloids contain both C6 and C9 side chains which are present as C9-saturated. C6-monounsaturated, and both C6-and C9-monounsaturated dialkylpyrrolidines. The structure of 2-(1-hex-5-enyl)-5-(1-non-8-enyl)pyrrolidine, a previously undescribed alkaloid, was proved by unambiguous synthesis after the location of the double bonds was established by the methoxymercuration-demercuration followed by mass spectrometry. The possible chemotaxonomic significance of the mixtures of venomous alkaloids produced by these species ofMonomorium is discussed.

Effect of handling and storage conditions and stabilizing agent on the recovery of viral RNA from oral fluid of pigs

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Inactivation of salivary enzymes by heating oral fluid for 15 min at 60 °C was detrimental to hepatitis E virus (HEV) RNA.

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HEV, F-RNA coliphage and murine norovirus RNA are not degraded in oral fluid stored at 4 °C for ≤24 h.

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Recovery of HEV RNA from oral fluid after 30 days at −20 °C was higher in the absence of RNA stabilizer.

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RNeasy Protect Saliva Mini kit does not work well for viral RNA.

There is an increasing interest in using oral fluid to determine herd health and documenting the circulation of viruses in commercial swine populations but little is known about the stability of viruses in oral fluid. Hepatitis E virus (HEV) is a zoonotic virus which is widespread in swine herds. Information on optimal handling methods such as heat treatments, freezing and RNA stabilization agents is needed to prevent or minimize degradation of viral RNA by degradative enzymes. The objectives of the study were to determine optimum handling conditions of the oral fluid before RNA extraction and to compare the performance of the RNeasy Protect Saliva Mini kit, which contains a stabilizing agent, with that of the QIAamp Viral RNA Mini kit, which does not contain a stabilizing agent. Preliminary studies with oral fluid inoculated with HEV indicated that a heat treatment of 60 °C for 15 min was detrimental to HEV RNA. HEV was recovered from 25/25 and 24/25 samples of oral fluid when samples were incubated for ≤24 h at 4 °C and 30 days at −20 °C, respectively, without a stabilizing agent and extracted with the QiaAMP kit. In contrast, HEV RNA was detected in 16/25 and 11/25 samples when samples were incubated with a stabilizing agent for 24 h at 37 °C and 30 days at −20 °C, respectively, and extracted with the RNeasy Protect Saliva kit. Moreover, the mean number of genome copies/ml of HEV recovered from oral fluid stored at −20 °C without the stabilizing agent was 2.9 log units higher than oral fluid stored at −20 °C in the presence of the stabilizing agent. The recovery of RNA from HEV, F-RNA coliphage MS2 and murine norovirus (MNV), which are surrogates for norovirus, was significantly greater when oral fluid was incubated for 24 h at 4 °C than when oral fluid was stabilized with RNAprotect Saliva Reagent for 24 h at 37 °C, where the relative differences between the two processes were 1.4, 1.8, and 2.7 log genome copies/ml for MS2, MNV, and HEV, respectively. The findings suggest that it is unnecessary to stabilize oral fluid from swine for the detection of viral RNA, provided the samples are stored at 4 °C or frozen at −20 °C, and that the RNeasy Protect Saliva Mini kit did not perform well for the detection of viral RNA.

Novel 2-ethyl-5-alkylpyrrolidines in the venom of an australian ant of the genusMonomorium

Novel 2-ethyl-5-alkylpyrrolidines and their corresponding 1-pyrrolines have been identified as poison gland products from an unidentified Australian species ofMonomorium. The major alkaloids present in the venom of this ant aretrans-2-ethyl-5-undecylpyrrolidine andtrans-2-ethyl-5-(12-tridecen-1-yl)pyrrolidine. The position of the double bond in the latter was established from its dimethyl-disulfide adduct after the amine function had been protected, and the stereochemistry of the alkyl groups was determined by direct comparison with synthetic compounds. The corresponding 1-pyrrolines were also detected in varying amounts in this venom. The pyrrolidines and 1-pyrrolines possess considerable insecticidal activity when evaluated against termite workers. The alkaloidal venoms ofMonomorium appear to be an important factor contributing to the success of these small ants both as competitors and as predators.

Chemistry of venom alkaloids in the ant genusMegalomyrmex

Chemical analyses of three species in the Neotropical ant genusMegalomyrmex have identified this taxon as the third myrmicine genus to produce alkaloids as major venom products. Workers ofM. leoninus and workers and ergatoids ofM. goeldii produce one or more of fourtrans-2,5-dialkylpyrrolidines previously identified in other myrmicine genera.M. modestus, on the other hand, is distinctive in producing the novel alkaloid (5E,8E)-3-butyl-5-hexylpyrrolizidine (5d), whose structure was established using a micro-Hofmann degradation sequence. The relationship ofMegalomyrmex to other alkaloid-producing ant genera is discussed along with the possible chemotaxonomic significance of the analyzed species when viewed in terms of the recognized species groups in this genus.

Chemistry of venom alkaloids in someSolenopsis (Diplorhoptrum) species from Puerto Rico

A number of 15-carbon alkaloids have been identified in venom extracts of four Puerto Rican species of ants in the genusSolenopsis (Diplorhoptrum). Workers of a species from El Verde produced thecis andtrans isomers of 2-methyl-6-nonylpiperidine with the latter isomer predominating. The same compounds were identified in queens of a species from Río Grande, but in this species no alkaloids were detected in worker extracts. Workers of aDiplorhoptrum species collected on Mona Island produced primarily atrans-2-methyl-6-(Z-4-nonenyl)piperidine,3, with smaller amounts of thecis isomer, whereas the major compound found in the queens of the same species on Mona Island was (5Z,9Z)-3-hexyl-5-methylindolizidine, identical with the alkaloid produced by queens of a species collected on Cabo Rojo. Surprisingly, workers of the Cabo Rojo species produced (5Z,9Z)- and (5E,9E)-3-butyl-5-propylindolizidine (4 and5, respectively) reported earlier as the 223AB indolizidines from skins of dendrobatid frogs. The possible significance of the qualitative and quantitative differences in the venom alkaloids synthesized by queens and workers is discussed as is the possibility that ants containing such alkaloids may serve as a dietary source for the skin alkaloids used by certain frogs in chemical defense.

Growth and filamentation of cold-adapted, log-phase Listeria monocytogenes exposed to salt, acid, or alkali stress at 3°C

In Canada, there is a zero tolerance for Listeria in a 125-g sample of product in which growth of Listeria monocytogenes can occur, and a limit of ≤100 CFU/g in ready-to-eat (RTE) food products that support limited growth during the stated shelf life and/or RTE refrigerated foods with a shelf life of ≤5 days. L. monocytogenes can form filaments in response to pH and osmotic, atmospheric, and temperature stress, which can result in an underestimation of the risk of RTE foods as filaments form single colonies on plate count agars but can divide into individual cells once the stress is removed. The objective was to investigate the filamentation characteristics of three strains of L. monocytogenes exposed to saline, acidic, basic, and simultaneous acidic and saline environments at 3°C. After 4 days at 3°C, log-phase cells grown in tryptic soy broth (TSB) were longer than cells grown at 15°C, and 68% of cells were below the reference value of the 90th percentile of control cultures. When cultures growing at 3°C were exposed to additional stresses, increases in the proportion and length of filaments in the population were observed, while increases in log CFU per milliliter were reduced. After 4 days of incubation at 3°C, the log CFU per milliliter of L. monocytogenes increased by 1.1 U in TSB and 0.4 to 0.5 U in TSB with 4% NaCl, TSB with a pH of 6.0 with 4% NaCl, and TSB with a pH of 5.5. Moreover, the longest 10% of cells were 6.4 to 8.5 times longer than control cells, and only 20 to 30% of cells were below the reference value. Cultures grown in TSB at pH 6.0 with 4% NaCl experienced more sustained filamentation than cultures grown in TSB with 4% NaCl, but less than cultures grown in TSB at pH 6.0. The mechanism involved in filamentation could be different for cells exposed to NaCl than exposed to acid, and additional stress might not necessarily result in more extensive filament formation. These findings contribute to a better understanding of the widespread potential of filament formation and the potential implications for food safety.

Survival of murine norovirus and F-RNA coliphage MS2 on pork during storage and retail display

The existence of animal strains of norovirus (NV) that are closely related to human strains raises concerns about interspecies recombination and the potential for zoonotic transmission through undercooked meat products. Contamination of meat with NV can occur both via meat processing operations and poor food handler hygiene. There is a lack of knowledge on the survival of NV on raw meat because NV cannot be effectively cultivated and its detection is limited to molecular methods. The survival of murine norovirus (MNV) and MS2, as surrogates for NV, was determined on pork chops by plaque assay and real time RT-PCR. Both MNV and MS2 displayed very high survival rates on vacuum packaged raw pork chops that were stored at 2°C for up to 7 weeks and numbers declined little during subsequent retail display for 7 days. Maximum reductions for MNV and MS2 were 1.0 log PFU/cm(2) and 0.6 log genome copies(GC)/cm(2) or 1.1 log PFU/cm(2) and 1.2 log GC/cm(2), respectively. The viability of MS2 and MNV was not affected by the proteolytic enzymes present in the meat nor by numbers of bacteria that increased with time during storage in vacuum packs and while on retail display. MNV and MS2 can be considered as good surrogates for NV on raw meat. The findings of this study indicate that potentially pathogenic NV will likely survive extremely well on fresh meat and consumers could potentially be at risk when consuming undercooked meat that is contaminated with NV.

Assessment of F-RNA coliphage as a potential indicator of enteric virus contamination of hog carcasses

Hepatitis E virus (HEV) is common in pigs, and some swine HEV strains are closely related to human strains. The zoonotic transmission of HEV is now well established. HEV can be detected by molecular techniques, but the significance of the presence of viral nucleic acid is questionable when foods are subjected to virus inactivation treatments. F-RNA coliphages are attractive candidates as indicators for enteric viruses because they are similar in size and survival characteristics and can be rapidly cultured. Information on the contamination of hog carcasses with enteric or hepatic viruses during slaughter is lacking. The objective of this study was to compare the incidence and levels of contamination of hog carcasses with F-RNA coliphages, HEV, total aerobic bacteria, coliforms, and Escherichia coli at different stages of the dressing process. Hog carcasses entering the commercial slaughter facility are heavily contaminated with F-RNA coliphages and HEV. Subsequent processes such as scalding, singing, and pasteurization can reduce the incidence and levels of F-RNA coliphages and HEV substantially to almost undetectable levels. Large discrepancies between the amount of viral nucleic acid and infectious F-RNA coliphage particles, both at high levels and low levels of contamination, were observed. The prevalence and levels of viable F-RNA coliphages were lower than those of total aerobic bacteria, coliforms, and E. coli in the anal area and on random sites before pasteurization. At a research abattoir, there was no overall mean reduction of viable F-RNA coliphages recovered from random sites before pasteurization and after washing, whereas overall mean reductions of 1.2, 2.6, and 2.9 log CFU for total aerobic bacteria, coliforms, and E. coli, respectively, were obtained. These findings suggest that bacteria such as coliforms and E. coli may not be suitable as indicators for enteric viruses in a meat processing environment.

Impact of riparian zone protection from cattle on nutrient, bacteria, F-coliphage, and loading of an intermittent stream

This 5-yr study compared, via an upstream-downstream experimental design, nutrient and microbial water quality of an intermittent stream running through a small pasture (∼2.5 animals ha) where cattle are restricted from the riparian zone (restricted cattle access [RCA]) and where cattle have unrestricted access to the stream (unrestricted cattle access [URCA]). Fencing in the RCA excluded pasturing cattle to within ∼3 to 5 m of the stream. Approximately 88% (26/32) of all comparisons of mean contaminant load reduction for lower, higher, and all stream flow conditions during the 5-yr study indicated net contaminant load reductions in the RCA; for the URCA, this percentage was 38% (12/32). For all flow conditions, mean percent load reductions in the RCA for nutrients and bacteria plus F-coliphage were 24 and 23%, respectively. These respective percentages for the URCA were -9 and -57% (positive values are reductions; negative values are increases). However, potentially as a result of protected wildlife habitat in the RCA, the mean percent load reduction for for "all flow" was -321% for the RCA and 60% for the URCA; for , these respective percentages were -209% (RCA) and 73% (URCA). For "all flow" situations, mean load reductions for the RCA were significantly greater ( < 0.1) than those from the URCA for NH-N, dissolved reactive phosphorus (DRP), total coliform, , and . For "high flow" situations, mean load reductions were significantly greater for the RCA for DRP, total coliform, and . For "low flow" conditions, significantly greater mean load reductions were in favor of the RCA for DRP, total P, total coliforms, fecal coliforms, , and . In no case were mean pollutant loads in the URCA significantly higher than RCA pollutant loads. Restricting pasturing livestock to within 3 to 5 m of intermittent streams can improve water quality; however, water quality impairment can occur if livestock have unrestricted access to a stream.

Dyslipidaemia is associated with testosterone, oestradiol and androgen receptor CAG repeat polymorphism in men with type 2 diabetes

OBJECTIVE

There is a high prevalence of low testosterone and dyslipidaemia in men with type 2 diabetes. The androgen receptor CAG repeat polymorphism (AR CAG) affects receptor transcriptional activity (the shorter repeats the more sensitive AR) and is associated with androgenic parameters and obesity. This study describes the relationships between testosterone, AR CAG and serum lipids in men with type 2 diabetes.

DESIGN AND PATIENTS

Cross-sectional study of men with type 2 diabetes in a District General Hospital Diabetes Centre.

MEASUREMENTS

Correlation between testosterone, AR CAG and serum lipids.

RESULTS

HDL cholesterol (HDL-C) correlated with total testosterone (TT) (r = 0·251, P < 0·001), bioavailable testosterone (BT) (r = 0·19, P = 0·001), free testosterone (FT) (r = 0·165, P = 0·005) and sex hormone-binding globulin (SHBG) (r = 0·147, P = 0·014). HDL-C did not correlate with oestradiol, but men with the lowest quartile of oestradiol had lower HDL-C compared to highest quartile (P = 0·046). Triglycerides correlated negatively with TT (r = -0·195, P = 0·001), BT (r = -0·148, P = 0·013) and SHBG (-0·14, P = 0·019) but not with FT or oestradiol. Total and LDL cholesterol (LDL-C) correlated negatively with oestradiol (r = -0·121, P = 0·05) but not with testosterone or SHBG. One-way anova testing across four quartiles of AR CAG showed a trend to alteration in HDL-C across groups of AR CAG (P = 0·08). HDL-C was significantly higher in men with the longest AR CAG compared with the shortest (1·19 vs 1·08 mmol/l, P = 0·02).

CONCLUSIONS

Lower testosterone and oestradiol levels in men with diabetes are associated with an adverse lipid profile. Shorter AR CAG is associated with low HDL-C and testosterone. The paradox that HDL-C is associated with low testosterone levels and a more active AR may suggest divergent effect of testosterone on HDL-C via genomic vs nongenomic mechanisms.

Testosterone deficiency: a risk factor for cardiovascular disease?

Male gender is a major risk factor for premature cardiovascular death, a relationship not yet explained. Low testosterone in men is a risk factor for the metabolic syndrome and type 2 diabetes and is associated independently with individual components of the metabolic syndrome--visceral obesity, insulin resistance, hyperglycemia, hypertension and dyslipidemia. Epidemiological studies report increased mortality in men with low testosterone. Testosterone replacement in the short-term reduces waist circumference, cholesterol and circulating pro-inflammatory cytokines and improves insulin sensitivity and glycemic control in diabetics. Testosterone also has beneficial effects on cardiac ischemia, angina and chronic heart failure. This manuscript reviews the current evidence supporting a link between low testosterone and cardiovascular disease, highlighting the need for larger, longer-term studies.

Testosterone acts as an efficacious vasodilator in isolated human pulmonary arteries and veins: evidence for a biphasic effect at physiological and supra-physiological concentrations

BACKGROUND

Testosterone is recognized to elicit vasodilatation in numerous vascular beds, however to date no study has investigated whether testosterone has this effect in the human pulmonary vasculature.

AIM

To determine whether isolated human pulmonary arteries and veins dilate in response to testosterone and whether the response differs in relation to gender, endothelial function or location with the pulmonary vasculature.

METHODS

Intralobar pulmonary arteries [no.=44, diameter =581 (349) microm] and veins [no.=27, diameter =573 (302) microm] were dissected from lobectomy samples obtained from male and female patients [no.=40, age =69 (8) yr]. Vessels were mounted in an automated wire myograph, bathed in physiological saline at 37 C and pH 7.4, and loaded to their in vivo pressure. Vessels were preconstricted with noradrenaline (10 microM) and exposed to acetylcholine (1 microM) to assess endothelial function, washed and then preconstricted with potassium chloride (1-100 mM) followed by either cumulative concentrations of testosterone (1 nM-100 microM) or ethanol vehicle (<0.1%).

RESULTS

Significant marked vasodilatation was seen in all vessels, irrespective of size, gender and endothelial function at micromolar concentrations. Testosterone triggered significant vasodilatation at concentrations > or = 10 nM in pulmonary arteries obtained from males, a response which was not observed in vessels from females. The maximal response at 100 microM was also significantly greater in male pulmonary arteries. Significant vasodilatation was only observed at physiological (nM) concentrations in pulmonary resistance arteries and pulmonary arteries with good endothelial function.

CONCLUSION

Testosterone acts as an efficacious vasodilator in the human pulmonary vasculature, with dilatation observed at physiological concentrations in the male arterial resistance bed, dependent on the presence of an intact endothelium.

Androgen receptor CAG repeat polymorphism is associated with serum testosterone levels, obesity and serum leptin in men with type 2 diabetes

OBJECTIVE

To determine the relationships between androgen receptor CAG repeat polymorphism length (AR CAG), sex hormones and clinical variables in men with type 2 diabetes (DM2). Men with DM2 are known to have a high prevalence of low testosterone levels. Studies suggest that testosterone replacement therapy may improve insulin sensitivity and glycaemic control in men with DM2 and reduces central obesity and serum leptin. AR CAG is known to correlate negatively with AR sensitivity and positively with body fat, insulin levels, and leptin in healthy men.

DESIGN

Cross-sectional study set in a district general hospital diabetes centre.

METHODS

Sex hormones, AR CAG and symptoms of hypogonadism were assessed in 233 men with DM2. Associations were sought between these variables and others such as obesity, leptin, glycaemic control, and blood pressure.

RESULTS

Testosterone was negatively associated and AR CAG positively associated with obesity and leptin. The associations of AR CAG with leptin and obesity were independent of testosterone, estradiol, gonadotropins, and age. AR CAG was also independently associated with total, bioavailable and free testosterone, LH, waist circumference, body mass index, leptin, and systolic blood pressure. There was no association of AR CAG with sex hormone binding globulin, estradiol, HbA(1C) or the symptoms of hypogonadism.

CONCLUSIONS

The association of longer AR CAG with obesity and leptin suggests that shorter AR CAG may have an influence in maintaining healthy anthropomorphics and metabolism in men with DM2. Testosterone and LH levels are higher in men with longer AR CAG, probably reflecting reduced negative feedback through a less sensitive receptor.

Testosterone replacement therapy

Hypgonadism has important adverse effects on the health and quality of life of affected men, but remains underdiagnosed in clinical practice. This article reviews the physiology, causes and diagnosis of hypogonadism and the potential benefits of treatment with testosterone replacement therapy.

Behaviours of log phase cultures of eight strains of Escherichia coli incubated at temperatures of 2, 6, 8 and 10 °C

The behaviours of cold-adapted, log-phase cultures of eight strains of Escherichia coli incubated at 2, 6, 8 and 10 degrees C for 10 days were examined by determining absorbance at 600 nm (A(600)), viable counts and cell size distribution as indicated by forward angle light scattering (FALS) values, obtained for samples collected each day from each culture. Cell lengths were determined from photomicrographs of samples for which the flow cytometry data indicated the mean cell lengths were maximal or minimal for each culture. At 2 degrees C, A(600) values for all strains and viable counts for some changed little, while viable counts for other strains declined progressively by >1 log unit. At 6 degrees C, A(600) values for most strains increased at progressively declining rates and then remained constant while viable counts increased to reach maximum values before maximum A(600) values were attained, and then declined. At 8 degrees C, the behaviours of most strains were similar to the behaviour at 6 degrees C. At 10 degrees C, seven of the strains grew exponentially, but for most of these the growth rate determined from A(600) values differed from that determined from viable count data. Mean FALS values for cultures incubated at 6, 8, or 10 degrees C showed various patterns of increase and decrease, indicating fluctuations in cell lengths. For all strains, the minimum cell length was <3 microm, but the maximum cell lengths ranged from <20 to >140 microm. The findings suggest that the formation of elongated cells or filaments is usual behaviour for E. coli growing at temperatures approaching or below the minimum for sustained growth.

The effect of testosterone replacement therapy on adipocytokines and C-reactive protein in hypogonadal men with type 2 diabetes

OBJECTIVE

Serum testosterone levels are known to inversely correlate with insulin sensitivity and obesity in men. Furthermore, there is evidence to suggest that testosterone replacement therapy reduces insulin resistance and visceral adiposity in type 2 diabetic men. Adipocytokines are hormones secreted by adipose tissue and contribute to insulin resistance. We examined the effects of testosterone replacement treatment on various adipocytokines and C-reactive protein (CRP) in type 2 diabetic men.

DESIGN

Double-blinded placebo-controlled crossover study in 20 hypogonadal type 2 diabetic men. Patients were treated with testosterone (sustanon 200 mg) or placebo intramuscularly every 2 weeks for 3 months in random order followed by a washout period of 1 month before the alternate treatment phase.

METHODS

Leptin, adiponectin, resistin, tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-6 and CRP levels were measured before and after each treatment phase. Body mass index (BMI) and waist circumference were also recorded.

RESULTS

At baseline, leptin levels significantly correlated with BMI and waist circumference. There was a significant inverse correlation between baseline IL-6 and total testosterone (r=-0.68; P=0.002) and bioavailable testosterone levels (r=-0.73; P=0.007). CRP levels also correlated significantly with total testosterone levels (r=-0.59; P=0.01). Testosterone treatment reduced leptin (-7141.9 +/- 1461.8 pg/ml; P=0.0001) and adiponectin levels (-2075.8 +/- 852.3 ng/ml; P=0.02). There was a significant reduction in waist circumference. No significant effects of testosterone therapy on resistin, TNF-alpha, IL-6 or CRP levels were observed.

CONCLUSION

Testosterone replacement treatment decreases leptin and adiponectin levels in type 2 diabetic men. Moreover, low levels of testosterone in men are associated with pro-inflammatory profile, though testosterone treatment over 3 months had no effect on inflammatory markers.

Interest and responsibility of ADA in dental licensure

Initial licensure is a critical milestone and point of entry to the profession; it should go without saying that the organization that represents more than 70% of professionally active dentists would care deeply about the process that determines the character of its future and defines its image in the eyes of the public. The American Dental Association's (ADA) documented history of activity and leadership on licensure issues and the organization's guiding documents (Strategic Plan, Current Policies, Principles of Ethics and Code of Professional Conduct and Constitution and Bylaws) all lend credence to the Association's role in the licensure process. ADA members, other dental organizations, private and governmental agencies, and the public recognize the ADA as an authority on matters relating to dentistry. These circumstances comprise the best available evidence supporting the important role of the ADA in facilitating communication, collaboration and consensus-building in the continuous enhancement of the licensure process to meet the needs of all stakeholders.

Setting control limits for Escherichia coli counts in samples collected routinely from pig or beef carcasses

Records of Escherichia coli counts in samples routinely collected from carcasses were obtained from one pork and three beef packing plants. The data obtained from each plant were divided into sets from consecutive 6-month periods. For each set of counts, log total counts were calculated for subsets of various sizes. For each set of log total counts, the mean (x), the standard deviation (SD), and an action limit of x + 3 SD were calculated, and the set was tested for a normal distribution. With the data from samples collected at the pork packing plant during 6 years, the proportion of samples with counts of zero in the 12 sets ranged from 15 to 45%. For that plant, appropriate action limits could be derived from log total counts for subsets of nine unit values. With the data from samples collected during 8 years at one beef packing plant, the proportion of samples with counts of zero in the 16 sets ranged from 88 to 99%. For that plant, appropriate action limits could be derived from log total counts for subsets of 15 unit values. With the data from samples collected during 2 or 2.5 years at each of the other beef packing plants, the proportion of samples with counts of zero in all sets was > 99%. For those data, action limits could not be derived from values for subsets of log total counts.

Selective inhibition of L-type Ca2+ channels in A7r5 cells by physiological levels of testosterone

Testosterone has marked beneficial cardiovascular effects, many of which have been attributed to a vasodilatory action. However, the molecular target of testosterone underlying this effect is subject to debate. In this study, we have used microfluorimetry as a noninvasive means of examining whether testosterone could exert dilatory effects via inhibition of voltage-gated Ca2+ entry in the model vascular smooth muscle cell line, A7r5. Rises of [Ca2+]i evoked by 50 mm K+ -containing solution were suppressed in a concentration-dependent manner by testosterone (IC50, 3.1 nm) and by the nonaromatizable analog, 5beta-dihydrotestosterone (IC50, 6.9 nm). The effects of testosterone were apparent in the presence of pimozide (to block T-type Ca2+ channels) but not nifedipine (to block L-type Ca2+ channels). Testosterone did not alter Ca2+ mobilization from intracellular stores by the prostaglandin analog U46619 or capacitative Ca2+ entry in cells pretreated with thapsigargin. Our results indicate that testosterone, at physiological concentrations, can selectively suppress Ca2+ entry into A7r5 cells via L-type Ca2+ channels. We suggest this effect is a likely mechanism underlying its vasodilatory actions and beneficial cardiovascular effects.

Testosterone replacement therapy improves insulin resistance, glycaemic control, visceral adiposity and hypercholesterolaemia in hypogonadal men with type 2 diabetes

OBJECTIVE

Low levels of testosterone in men have been shown to be associated with type 2 diabetes, visceral adiposity, dyslipidaemia and metabolic syndrome. We investigated the effect of testosterone treatment on insulin resistance and glycaemic control in hypogonadal men with type 2 diabetes.

DESIGN

This was a double-blind placebo-controlled crossover study in 24 hypogonadal men (10 treated with insulin) over the age of 30 years with type 2 diabetes.

METHODS

Patients were treated with i.m. testosterone 200 mg every 2 weeks or placebo for 3 months in random order, followed by a washout period of 1 month before the alternate treatment phase. The primary outcomes were changes in fasting insulin sensitivity (as measured by homeostatic model index (HOMA) in those not on insulin), fasting blood glucose and glycated haemoglobin. The secondary outcomes were changes in body composition, fasting lipids and blood pressure. Statistical analysis was performed on the delta values, with the treatment effect of placebo compared against the treatment effect of testosterone.

RESULTS

Testosterone therapy reduced the HOMA index (-1.73 +/- 0.67, P = 0.02, n = 14), indicating an improved fasting insulin sensitivity. Glycated haemoglobin was also reduced (-0.37 +/- 0.17%, P = 0.03), as was the fasting blood glucose (-1.58 +/- 0.68 mmol/l, P = 0.03). Testosterone treatment resulted in a reduction in visceral adiposity as assessed by waist circumference (-1.63 +/- 0.71 cm, P = 0.03) and waist/hip ratio (-0.03 +/- 0.01, P = 0.01). Total cholesterol decreased with testosterone therapy (-0.4 +/- 0.17 mmol/l, P = 0.03) but no effect on blood pressure was observed.

CONCLUSIONS

Testosterone replacement therapy reduces insulin resistance and improves glycaemic control in hypogonadal men with type 2 diabetes. Improvements in glycaemic control, insulin resistance, cholesterol and visceral adiposity together represent an overall reduction in cardiovascular risk.

Consequences for host-parasitoid interactions of grazing-dependent habitat heterogeneity

1. Environmental heterogeneity can produce effects that cascade up to higher trophic levels and affect species interactions. We hypothesized that grazing-dependent habitat heterogeneity and grazing-independent host plant heterogeneity would influence directly and indirectly a host-parasitoid interaction in a woodland habitat. 2. Thistles were planted randomly in 20 birch woodlands, half of which are grazed by cattle. The abundances of two species of seed herbivore and their shared parasitoid were measured, and related to habitat and host-plant heterogeneity. 3. The presence of cattle grazing created a structurally and compositionally distinct plant assemblage from the ungrazed seminatural situation. Grazing did not affect the number or dispersion of the host plant underpinning the host-parasitoid interaction. 4. The density of one insect herbivore, Tephritis conura, and its parasitoid Pteromalus elevatus was significantly increased by the presence of cattle; but another herbivore, Xyphosia miliaria, was unaffected. The percentage of parasitism of T. conura was increased in grazed habitat occurring at twice the rate found in ungrazed habitat. 5. The increase in T. conura abundance was correlated with increased species richness and cover of forbs in grazed sites. This effect of grazing-dependent habitat variation on host insect density cascaded up to parasitoid density and percentage of parasitism. Habitat heterogeneity had a further direct, positive effect on parasitoid density and percentage of parasitism after controlling for host-insect density. 6. Independent of grazing, heterogeneity in host-plant flowering, architecture and stature further affected T. conura and its parasitoid's densities. Parasitoid density was also affected by the dispersion of the host plant. 7. A combination of habitat and host-plant scale environmental heterogeneity influenced a host-parasitoid interaction indirectly and directly, providing a rare example of an anthropogenic disturbance positively affecting a tertiary trophic level. This finding highlights the need to consider not only the importance of bottom-up effects for top-down processes, but also the role of environmental heterogeneity arising from anthropogenic disturbance for trophic interactions such as parasitism.

Junior doctors and the full shift rota--psychological and hormonal changes: a comparative cross-sectional study

We studied the hormonal and psychological effect of the full shift rota on junior doctors after implementation of the European Working Time Directive, using a comparative, cross-sectional study design of male doctors in South Yorkshire. Cortisol and testosterone levels were measured and subjects completed the general health questionnaire (GHQ-12) and the androgen deficiency in the aging male screening questionnaire (ADAM), after a week of holiday (baseline), a week of nights, and a normal working week. The results showed that cortisol levels decreased from 480.6 +/- 33.1 nmol/l at baseline (after a week of holiday), to 355.7 +/- 29.1 nmol/l post normal working week (p = 0.003); to 396.7 +/- 32.5 nmol/l post nights (p = 0.03). GHQ-12 scores increased from 0.5 +/- 0.3 at baseline, to 1.8 +/- 0.5 post normal working week (p = 0.02) and to 2.3 +/- 0.5 post nights (p = 0.005). These results suggest that there are still appreciable physiological consequences with new work patterns.

Differential expression of proteins in cold-adapted log-phase cultures of Escherichia coli incubated at 8, 6 or 2 degrees C

Temperature is used to control the growth of microorganisms in foods. The minimum temperature for sustained growth of Escherichia coli is 7 degrees C. E. coli cells in the logarithmic phase of growth at 15 degrees C were incubated at 8, 6 or 2 degrees C. The cells grew with the formation of filaments at the two higher temperatures, but did not grow at 2 degrees C. In order to investigate more thoroughly the nature of filament formation in E. coli at temperatures near the minimum temperature for sustained growth, cells were harvested after 1 day at 2 degrees C or at times up to 4 or 8 days at 8 or 6 degrees C, respectively. Proteins extracted from the cells were separated by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), and spots containing differentially expressed proteins were identified by quadropole time-of-flight tandem (Q-ToF-2) mass spectrometry. For most of the identified proteins, the amounts were not substantially different in cells grown at 15 degrees C or incubated at 2 degrees C. In cells incubated at 8 or 6 degrees C, proteins associated with stress responses, the tricarboxylic acid cycle and electron transport were present in substantially greater amounts, and proteins associated with protein synthesis were present in substantially smaller amounts than in cells grown at 15 degrees C. These findings suggest that the stringent response is induced in E. coli incubated at temperatures near the minimum for growth, so the formation of filaments at those temperatures may be a result of the stringent response.

Falsely high glycated haemoglobin [HbA1C] because of haemoglobin OSU-Christiansborg

Glycated haemoglobin (HbA1c) is routinely used to assess the degree of glycaemic control in diabetic patients. We report a case of a 73 year old diabetic woman who had an elevated HbA1c of 13.4%. She was on maximum oral hypoglycaemic agents and was commenced on insulin. However, her HbA1c continued to remain high at 20.4%. Subsequent tests revealed that she had a haemoglobin variant, Haemoglobin Osu-Christiansborg, causing the falsely high glycated haemoglobin.

Androgens, insulin resistance and vascular disease in men

Type 2 diabetes mellitus is increasing globally and is an established risk factor for the development of atherosclerotic vascular disease. Insulin resistance is the hallmark feature of type 2 diabetes and is also an important component of the metabolic syndrome. There is evidence to suggest that testosterone is an important regulator of insulin sensitivity in men. Observational studies have shown that testosterone levels are low in men with diabetes, visceral obesity (which is strongly associated with insulin resistance), coronary artery disease and metabolic syndrome. Short-term interventional studies have also demonstrated that testosterone replacement therapy produces an improvement in insulin sensitivity in men. Thus hypotestosteronaemia may have a role in the pathogenesis of insulin-resistant states and androgen replacement therapy could be a potential treatment that could be offered for improvements in glycaemic control and reduction in cardiovascular risk, particularly in diabetic men.

Chemical odorant of colonial seabird repels mosquitoes

The crested auklet, Aethia cristatella, emits a class of aldehydes shown to be potent invertebrate repellents when used by heteropterans against their predators. Our aim was to determine the efficacy of these aldehydes against mosquitoes in the laboratory. Synthetic analogues of the auklet odorant were strongly repellent to mosquitoes in controlled laboratory trials. Furthermore, the efficacy was similar to previous reports for commercial mosquito repellents. These results, in combination with a previously published study, show that constituents of the aldehyde odorant are broad spectrum in efficacy against ectoparasitic arthropods of birds. Our report is the first empirical evidence for an endogenous mosquito repellent in birds.

Smoking and hormones in health and endocrine disorders

Smoking has multiple effects on hormone secretion, some of which are associated with important clinical implications. These effects are mainly mediated by the pharmacological action of nicotine and also by toxins such as thiocyanate. Smoking affects pituitary, thyroid, adrenal, testicular and ovarian function, calcium metabolism and the action of insulin. The major salient clinical effects are the increased risk and severity of Graves' hyperthyroidism and opthalmopathy, osteoporosis and reduced fertility. Smoking also contributes to the development of insulin resistance and hence type 2 diabetes mellitus. An important concern is also the effect of smoking on the foetus and young children. Passive transfer of thiocyanate can cause disturbance of thyroid size and function. Furthermore, maternal smoking causes increased catecholamine production, which may contribute to under perfusion of the foetoplacental unit.

Molecular tagging of a senescence gene by introgression mapping of a stay-green mutation from Festuca pratensis

* Intergeneric hybrids between Lolium multiflorum and Festuca pratensis (Lm/Fp) and their derivatives exhibit a unique combination of genetic and cytogenetic characteristics: chromosomes undergo a high frequency of homoeologous recombination at meiosis; the chromosomes of the two species can easily be discriminated by genomic in situ hybridization (GISH); recombination occurs along the entire length of homoeologous bivalents; a high frequency of marker polymorphism is observed between the two species. * This combination of characters has been used to transfer and isolate a F. pratensis chromosome segment carrying a mutant 'stay-green' gene conferring a disrupted leaf senescence phenotype into L. multiflorum. * The genetic location within the introgressed F. pratensis segment of the senescence gene has been mapped using amplified fragment length polymorphisms (AFLPs), and F. pratensis-specific AFLP markers closely flanking the green gene have been cloned. * The use of these cloned sequences as markers for the stay-green locus in marker-assisted selection programmes has been tested. The potential application of Lm/Fp introgressions as a tool for the map-based cloning of introgressed Fp genes is discussed.

The chemistry of exploding ants, Camponotus spp. (cylindricus complex)

A detailed comparative analysis of the exocrine chemistry of nine Bruneian Camponotus species in the cylindricus complex is reported. Workers of these species are known to have hypertrophied mandibular glands and release their glandular contents suicidally from the head by rupturing the intersegmental membrane of the gaster. All of the species produce mixtures of polyacetate-derived aromatics, including hydroxyacetophenones, which display pH-dependent color changes, and aliphatic hydrocarbons and alcohols. In addition, three species contained (6R)-2,6-dimethyl-(2E)-octen-1,8-dioic acid (9) or (3S)-8-hydroxycitro-nellic acid (10a), previously unreported from insects. These compounds were characterized from their spectral data, and confirmed by comparison with synthetic samples. The allomonal role of these compounds is based on numerous field observations, and their chemotaxonomic value is presented.

6-Alkylsalicylic Acids and 6-Alkylresorcylic Acids from Ants in the Genus Crematogaster from Brunei

The defensive chemistry of two species of ants from Brunei in the genus Crematogaster (Physocrema group) has been investigated. Ants in this group release a white secretion from hypertrophied metapleural glands on their thorax when they are disturbed. Previously, one species in this group has been shown to produce alkylphenols and alkylresorcinols. In the present investigation, similar compounds along with salicylic acids and resorcylic acids that are anacardic acid and olivetolic acid homologs, respectively, are described from two species. The structures of these compounds were suggested by their spectroscopic data and confirmed by direct comparison with synthetic samples. Some of these compounds occur in lichens and have well documented physiological activities.

Correlation of VEGF production with IL1 alpha and IL6 secretion by human pituitary adenoma cells

OBJECTIVES

Vascular endothelial growth factor (VEGF) is considered to be the most important angiogenic factor involved in the neovascularisation of solid tumours. Regulatory molecules include cytokines and growth factors. Interleukin (IL)1 and IL6 have both been shown to regulate VEGF levels in a variety of tissues. The role of cytokines in the pathogenesis of pituitary tumours remains unclear. We have examined the expression of VEGF and its relationships with IL1 and IL6 in the human pituitary tumour cell line HP75 and a series of human pituitary tumours. We have also looked at the relationship of tumour volume and invasive status to VEGF secretion.

METHODS

Surgically resected tumours were routinely cultured in single-cell suspension at 200 K/well (standard unit for culture of dispersed primary pituitary adenoma cells). We measured VEGF, IL1 alpha and IL6 levels by ELISA. Tumour volume and invasion grade were assessed by preoperative magnetic resonance imaging.

RESULTS

VEGF was detected in conditioned medium of HP75 cells (900+/-52 pg/ml) and in 82% of tumours tested (range 26-16 464 pg/ml). Tumour volume and secretion of VEGF were significantly associated with levels of IL6 (volume, P = 0.056; VEGF, P < 0.001 (P values based on Spearman's test)) and IL1 alpha produced (volume, P < 0.005; VEGF, P < 0.001). Invasive tumours showed a higher basal secretion of VEGF that that of the non-invasive type; however, this difference was not significant. Addition of exogenous IL1 alpha, but not IL6, significantly increased VEGF production.

CONCLUSIONS

The significant associations between VEGF and the levels of IL6 and IL1 alpha suggest an important role for these cytokines in the development of these tumours.

Testosterone does not adversely affect fibrinogen or tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) levels in 46 men with chronic stable angina

OBJECTIVE

In women, sex hormones cause increased morbidity and mortality in patients with coronary heart disease (CHD) and adversely affect the coagulation profile. We have studied the effect of physiological testosterone replacement therapy in men on coagulation factor expression, to determine if there is an increased risk of thrombosis.

METHODS

Double-blind, randomized, placebo-controlled trial of testosterone in 46 men with chronic stable angina. Measurements of free, total and bioavailable testosterone, luteinising hormone (LH) and follicle-stimulating hormone (FSH), estradiol, plasminogen activator inhibitor-1 (PAI-1), fibrinogen, tissue plasminogen activator (tPA) and full blood count were made at 0, 6 and 14 weeks.

RESULTS

Bioavailable testosterone levels were: 2.58 +/- 0.58 nmol/l at baseline, compared with 3.35 +/- 0.31 nmol/l at week 14 (P < 0.001) after treatment compared with 2.6 +/- 0.18 nmol/l and 2.44 +/- 0.18 nmol/l in the placebo group (P was not significant). There was no change in fibrinogen (3.03 +/- 0.18 g/l at baseline and 3.02 +/- 0.18 g/l at week 14, P = 0.24), tPA activity (26.77 +/- 4.9 Iu/ml and 25.67 +/- 4.4 Iu/ml, P = 0.88) or PAI-1 activity (0.49 +/- 0.85 Iu/ml and 0.36 +/- 0.06 Iu/ml, P = 0.16) with active treatment and no differences between the groups (at week 14, P value 0.98, 0.59 and 0.8 for fibrinogen, PAI-1 and tPA respectively). Haemoglobin concentration did not change over time, in the testosterone group (1.44 +/- 0.02 g/l and 1.45 +/- 0.02 g/l, P = 0.22).

CONCLUSION

Physiological testosterone replacement does not adversely affect blood coagulation status.

Testosterone replacement therapy: current trends and future directions

Male hypogonadism is characterized by abnormally low serum testosterone levels associated with typical symptoms, including mood disturbance, sexual dysfunction, decreased muscle mass and strength, and decreased bone mineral density. By restoring serum testosterone levels to the normal range using testosterone replacement therapy, many of these symptoms can be relieved. For many years, injectable testosterone esters or surgically implanted testosterone pellets have been the preferred treatment for male hypogonadism. Recently, newer treatment modalities have been introduced, including transdermal patches and gels. The development of a mucoadhesive sustained-release buccal tablet is the latest innovation, which will provide patients with an additional option. The availability of new treatment modalities has helped to renew interest in the management of male hypogonadism, highlighting the need to address a number of important but previously neglected questions in testosterone replacement therapy. These include the risks and benefits of treatment in different patient populations (e.g. the elderly) and the need for evidence-based diagnosis and treatment monitoring guidelines. While some recommendations have been developed in individual countries, up-to-date, internationally accepted evidence-based guidelines that take into account national differences in clinical practice and healthcare delivery would optimize patient care universally.

Testosterone replacement in hypogonadal men with angina improves ischaemic threshold and quality of life

BACKGROUND

Low serum testosterone is associated with several cardiovascular risk factors including dyslipidaemia, adverse clotting profiles, obesity, and insulin resistance. Testosterone has been reported to improve symptoms of angina and delay time to ischaemic threshold in unselected men with coronary disease.

OBJECTIVE

This randomised single blind placebo controlled crossover study compared testosterone replacement therapy (Sustanon 100) with placebo in 10 men with ischaemic heart disease and hypogonadism.

RESULTS

Baseline total testosterone and bioavailable testosterone were respectively 4.2 (0.5) nmol/l and 1.7 (0.4) nmol/l. After a month of testosterone, delta value analysis between testosterone and placebo phase showed that mean (SD) trough testosterone concentrations increased significantly by 4.8 (6.6) nmol/l (total testosterone) (p = 0.05) and 3.8 (4.5) nmol/l (bioavailable testosterone) (p = 0.025), time to 1 mm ST segment depression assessed by Bruce protocol exercise treadmill testing increased by 74 (54) seconds (p = 0.002), and mood scores assessed with validated questionnaires all improved. Compared with placebo, testosterone therapy was also associated with a significant reduction of total cholesterol and serum tumour necrosis factor alpha with delta values of -0.41 (0.54) mmol/l (p = 0.04) and -1.8 (2.4) pg/ml (p = 0.05) respectively.

CONCLUSION

Testosterone replacement therapy in hypogonadal men delays time to ischaemia, improves mood, and is associated with potentially beneficial reductions of total cholesterol and serum tumour necrosis factor alpha.

Population dynamics and gene transfer in genetically modified bacteria in a model microcosm

The horizontal transfer and effects on host fitness of a neutral gene cassette inserted into three different genomic loci of a plant-colonizing pseudomonad was assessed in a model ecosystem. The KX reporter cassette (kanamycin resistance, aph, and catechol 2, 3, dioxygenase, xylE) was introduced on the disarmed transposon mini-Tn5 into: (I) the chromosome of a spontaneous rifampicin resistant mutant Pseudomonas fluorescens SBW25R; (II) the chromosome of SBW25R in the presence of a naturally occurring lysogenic-phage (phage Phi101); and (III) a naturally occurring plasmid pQBR11 (330 kbp, tra+, Hgr) introduced into SBW25R. These bacteria were applied to Stellaria media (chickweed) plants as seed dressings [c. 5 x 104 colony-forming units (cfu)/seed] and the seedlings planted in 16 microcosm chambers containing model plant and animal communities. Gene transfer to pseudomonads in the phyllosphere and rhizosphere was found only in the plasmid treatment (III). Bacteria in the phage treatment (II) initially declined in density and free phage was detected, but populations partly recovered as the plants matured. Surprisingly, bacteria in the chromosome insertion treatment (I) consistently achieved higher population densities than the unmanipulated control and other treatments. Plasmids were acquired from indigenous bacterial populations in the control and chromosome insertion treatments. Plasmid acquisition, plasmid transfer from inocula and selection for plasmid carrying inocula coincided with plant maturation.

Pharmacokinetics and tolerability of a bioadhesive buccal testosterone tablet in hypogonadal men

OBJECTIVE

A phase I single centre, open label study of the pharmacokinetics and tolerability of a buccal testosterone tablet (COL 1621) was carried out.

DESIGN

Twelve testosterone-deficient males were treated with the buccal tablet twice daily for 7 consecutive days. Multiple blood samples were drawn for testosterone, dihydrotestosterone (DHT), bioavailable testosterone and sex hormone-binding globulin (SHBG).

RESULTS

After COL 1621, means+/-S.D. serum testosterone level increased to a peak concentration of 26.6+/-5.8 nmol/l (7.7+/-1.7 ng/ml) at 4.8+/-5.8 h and stayed in the eugonadal range. Steady state was achieved within the first 24 h and was maintained in the normal range. The bioavailable testosterone, DHT and free testosterone index followed a pattern very similar to that of testosterone. The mean serum testosterone to DHT ratio was within the normal male range throughout treatment. There was only one treatment-related adverse event (headache). Two-thirds of patients indicated that treatment with COL 1621 was acceptable and that the tablet was convenient to use. Six patients (50.0%) preferred COL 1621 to their previous testosterone replacement therapy, two patients gave preference to their previous treatment and three patients found both treatments to be equally acceptable. Data for one patient was not available.

CONCLUSION

We conclude that COL 1621 can efficiently elevate serum testosterone and DHT levels in hypogonadal men within the first day of application, achieve a steady state within 24 h and maintain serum testosterone in the normal range with a twice-daily treatment regimen. COL 1621 provides an effective alternative oral testosterone replacement therapy that gives physiological levels of testosterone and is well tolerated by the patients.

The Venom Alkaloids from Some African Monomorium Species

A comparative analysis of the venom alkaloids of 13 species of ants in the genus Monomorium collected in Africa was undertaken. Ants were collected in Kenya and South Africa. Most species produced 2,5-dialkylpyrrolidines and some of their analogous 1-pyrrolines. No alkaloids were detected in two species. M. robustior and M. macrops. Additionally, a novel 2-alkyl-1-pyrroline, whose structure was established by synthesis, was detected in M. notulum. This compound and others like it may serve as biosynthetic precursors for the formation of the 2,5-dialkylpyrrolidines found in many Myrmicine ant species.

Expression of interleukin-6 and its effects on growth of HP75 human pituitary tumor cells

The role of IL-6 in the pathogenesis of pituitary adenomas is unclear, as tumor biology is difficult to study in primary culture. We have shown here that the human pituitary cell line HP75 synthesizes IL-6 mRNA and expresses and secretes IL-6 (6167 +/- 56 pg/ml/72 h for 30,000 cells). IL-6 receptor (IL-6R) mRNA was identified by in situ hybridization and RT-PCR. Exogenous IL-6 in low dose (1 ng/ml) stimulated, whereas higher doses (100 ng/ml) inhibited, growth. This diverse effect occurs in other cell types as a result of receptor down-regulation. Cell growth was inhibited by IL-6-blocking antibody (76 +/- 6.5% inhibition; P < 0.0001). This demonstrates that IL-6 is an important growth regulator in HP75 cells, having an autocrine growth stimulatory effect under basal conditions. IL-1alpha and dibutyryl cAMP stimulated and dexamethasone inhibited IL-6 secretion; however, bacterial lipopolysaccharide, forskolin, and cholera toxin had no effect. This implies that there is a defect in the control of IL-6 secretion. Soluble IL-6R was not detected, but soluble gp130 receptor was present in the conditioned medium. Stimulation of cleavage of soluble IL-6R from the membrane-bound IL-6R could not be induced by phorbol ester or dexamethasone. Whether IL-6 has a similar effect in human pituitary adenomas requires further investigation.

Testosterone inhibits the prostaglandin F2alpha-mediated increase in intracellular calcium in A7r5 aortic smooth muscle cells: evidence of an antagonistic action upon store-operated calcium channels

Testosterone-induced vasodilatation is proposed to contribute to the beneficial effects associated with testosterone replacement therapy in men with cardiovascular disease, and is postulated to occur via either direct calcium channel blockade, or through potassium channel activation via increased production of cyclic nucleotides. We utilised flow cytometry to investigate whether testosterone inhibits the increase in cellular fluorescence induced by prostaglandin F(2alpha) in A7r5 smooth muscle cells loaded with the calcium fluorescent probe indo-1-AM, and to study the cellular mechanisms involved. Two-minute incubation with testosterone (1 microM) significantly inhibited the change in cellular fluorescence in response to prostaglandin F(2alpha) (10 microM) (3.6+/-0.6 vs 7.6+/-1.0 arbitrary units, P=0.001). The change in cellular fluorescence in response to prostaglandin F(2alpha) (10 microM) was also significantly attenuated in the absence of extracellular calcium (3.6+/-0.3 vs 15.6+/-0.7 arbitrary units, P=0.0000002), and by a 2-min incubation with the store-operated calcium channel blocker SK&F 96365 (50 microM) (4.7+/-0.8 vs 8.1+/-0.4 arbitrary units, P=0.003). The response was insensitive to similar incubation with the voltage-operated calcium channel blockers verapamil (10 microM) (12.6+/-1.2 vs 11.9+/-0.2 arbitrary units, P=0.7) or nifedipine (10 microM) (13.9+/-1.3 vs 13.3+/-0.5 arbitrary units, P=0.7). Forskolin (1 microM) and sodium nitroprusside (100 microM) significantly increased the cellular concentration of cyclic adenosine monophosphate and cyclic guanosine monophosphate respectively, but testosterone (100 nM-100 microM) had no effect. These data indicate that the increase in intracellular calcium in response to prostaglandin F(2alpha) occurs primarily via extracellular calcium entry through store-operated calcium channels. Testosterone inhibits the response, suggesting an antagonistic action upon these channels.