Determinants of platelet responsiveness to nitric oxide in patients with chronic heart failure

Congestive heart failure (CHF) is associated with oxidative stress. Platelet responsiveness to nitric oxide (NO) donors, are impaired in patients with angina pectoris, possibly by increasing oxidative stress. We investigated the occurrence of platelet resistance to NO in patients, with ischaemic or non-ischaemic cardiomyopathy compared with normal subjects. Anti-aggregatory effects of sodium nitroprusside (SNP), oxidative stress and whole blood superoxide anion content were determined, with correlates of responsiveness to SNP. Inhibition of platelet aggregation by SNP was 65.4+/-3.55% in controls and 59.3+/-4.1% in CHF (P=ns) despite increased oxidative stress and post-aggregation O2- in CHF patients. However, subsets of CHF patients have NO-resistant platelets: this is associated with increasing age and/or increased oxidative stress (both p<0.05).

Incidence, survival and risk factors for the development of veno-occlusive disease in pediatric hematopoietic stem cell transplant recipients

The incidence, risk factors and mortality of veno-occlusive disease (VOD) were identified for 142 pediatric hematopoietic stem cell (HSC) transplant recipients with hematological malignancies (83), solid tumors (41) and nonmalignant diseases (18). This historical cohort of 142 HSC transplant patients, from January 1993 through June 2000, was assessed by chart review. Risk factors for the development of VOD and mortality were assessed by multiple logistic regression and Kaplan-Meier survival curves respectively. The incidence of VOD was 18.3% (26/142 transplants). Multivariate analysis reconfirmed the known pretransplant risk factors of induction therapy with busulfan and transplantation with matched unrelated donor cells as significant risk factors for the development of VOD. In addition, two new risk factors, positive CMV serology in the recipient and TPN provided in the 30 days prior to transplant, were identified. Mortality in transplant patients at 100 days was greater in the VOD-positive group (10/26 (38.5%)) compared to the VOD-negative group (11/116 (9.5%) (P=0.001)). The risk of death was 4.97 times higher with 95% CIs (2.11, 11.71) for the VOD-positive group. Decreasing the risk factors for VOD may decrease mortality in this patient population.

Phosphatidylinositol Phosphate Kinases Put PI4,5P 2 in Its Place

Phosphatidylinositol 4,5 bisphosphate (PI4,5P(2)) is a critical second messenger that regulates a myriad of diverse cellular activities including modulation of the actin cytoskeleton, vesicle trafficking, focal adhesion formation, and nuclear events. In order to effectively regulate these disparate cellular events, synthesis of PI4,5P(2) by phosphatidylinositol phosphate kinases (PIP kinases) must be both spatially and temporally regulated. Two subfamilies of PIP kinases, types I and II, allow the generation of PI4,5P(2) from independent pools of substrate, PI(4)P and PI(5)P respectively. In turn, type I and II PIP kinases show different subcellular localization and thus are involved in distinct signaling pathways. Additionally, several type I isoforms, and their splice variants, have now been shown to be differentially localized throughout the cell and to be involved in the synthesis of PI4,5P(2) at distinct sites. These findings implicate PIP kinases as the major regulators of PI4,5P(2)-mediated events, making them key signaling enzymes in a variety of processes. Understanding the mechanisms regulating spatial and temporal synthesis of PI4,5P(2) by PIP kinases is vital for understanding these processes as a whole. This review examines both structural and regulatory features that modulate activity, localization, and substrate usage of PIPKs.

Demonstration of progesterone receptor-mediated gonadotrophin suppression in the human male

OBJECTIVE

Synthetic gestogens in combination with testosterone have potential as a male hormonal contraceptive, predominantly acting by augmenting suppression of gonadotrophin secretion. Little is known, however, of the effects of gestogens in the male. Gestogens have affinity for both androgen and progesterone receptors but the relative contribution of action at these two receptors in gonadotrophin suppression remains unclear. In this study the effects of progesterone, with no significant androgen-receptor affinity are compared to desogestrel, a synthetic gestogen with relatively low affinity for the androgen receptor, on gonadotrophin secretion in normal men.

DESIGN

Subjects received either 50 mg progesterone intramuscularly (i.m.) or 300 micro g desogestrel orally daily for 7 days. Frequent blood sampling over 12 h was undertaken before and after drug administration. GnRH [100 micro g intravenously (i.v.)] was administered 2 h before the end of the frequent sampling period.

SUBJECTS

Twenty healthy men were randomly allocated to the two treatment groups.

RESULTS

Both progesterone and desogestrel administration resulted in decreases in the concentration of both LH and FSH secretion, as well as testosterone. Analysis of the pulsatile nature of LH secretion indicated that both treatments reduced LH pulse amplitude, and that progesterone reduced LH pulse frequency. Progesterone, but not desogestrel, treatment also reduced the increase in LH secretion in response to GnRH.

CONCLUSIONS

The effects of progesterone were at least as marked as those of a maximally effective dose of desogestrel. As progesterone has negligible affinity for the androgen receptor, these results are compatible with the suppressive effects of synthetic 19-norgestogens on gonadotrophin secretion in the male being mediated via the progesterone receptor, with its androgenicity contributing minimally to gonadotrophin suppression.

Effects of insulin lispro and chronic vitamin C therapy on postprandial lipaemia, oxidative stress and endothelial function in patients with type 2 diabetes mellitus

BACKGROUND

Insulin therapy may influence cardiovascular disease (CVD) and lipid metabolism in type 2 diabetes (T2D). Exaggerated postprandial lipaemia (PPL) is a feature of diabetic dyslipidaemia affecting CVD via enhanced oxidative stress (OS) and endothelial dysfunction. We assessed endothelial function and OS during PPL following insulin and vitamin C. Twenty (17 M) T2D patients were studied (mean Hba1c 8.4%) at baseline, following 6 weeks of insulin lispro (0.2 Iu kg-1) and vitamin C 1-g daily. Eight-h lipid and glucose profiles were measured following a fatty meal. Endothelial function (flow-mediated vasodilatation: FMD) and OS were measured at fasting, 4 h and 8 h.

MATERIALS AND METHODS

Glucose, body mass index, and total and LDL cholesterol remained unchanged. FMD improved. Placebo group: fasting, 1.1 +/- 1.2 to 4.2 +/- 1.1% (P < 0.001); 4-h, 0.3 +/- 1.2 to 3.1 +/- 0.9% (P < 0.01); 8-h, 0.7 +/- 1.1 to 3.76 +/- 1.1% (P < 0.001). Vitamin C group: fasting, 0.9 +/- 1.1 to 6.1 +/- 1.3% (P < 0.001); 4-h, 0.7 +/- 1.5 to 4.9 +/- 2.1% (P < 0.001); 8-h, 0.8 +/- 0.9 to 5.8 +/- 0.6% (P < 0.01). Post-prandial lipaemia was attenuated: TG area-under-curve (mmol L-1 8 h-1), 52.6 +/- 11 to 39.1 +/- 12.5 (placebo group), P < 0.02; and 56.9 +/- 8 to 40.1 +/- 10.3 (vitamin C group), P < 0.02. Oxidative stress was reduced, with greater changes in the vitamin C group.

CONCLUSION

Insulin may thus exert vascular benefits in T2D, by modifying fasting and postprandial lipid metabolism resulting in reduced OS and improved EF. Vitamin C therapy may augment the vascular benefits of insulin in T2D through additional effects on OS and EF.

Male contraception

The provision of safe, effective contraception has been revolutionized in the past 40 yr following the development of synthetic steroids and the demonstration that administration of combinations of sex steroids can be used to suppress ovulation and, subsequently, other reproductive functions. This review addresses the current standing of male contraception, long the poor relation in family planning but currently enjoying a resurgence in both scientific and political interest as it is recognized that men have a larger role to play in the regulation of fertility, whether seen in geopolitical or individual terms. Condoms and vasectomy continue to be popular at particular phases of the reproductive lifespan and in certain cultures. Although not perfect contraceptives, condoms have the additional advantage of offering protection from sexually transmitted infection. The hormonal approach may have acquired the critical mass needed to make the transition from academic research to pharmaceutical development. Greatly increased understanding of male reproductive function, partly stimulated by interest in ageing and the potential benefits of androgen replacement, is opening up other avenues for investigation taking advantage of nonhormonal regulatory pathways specific to spermatogenesis and the reproductive tract.

Investigation of hormonal male contraception in African men: suppression of spermatogenesis by oral desogestrel with depot testosterone

BACKGROUND

Suppression of spermatogenesis to azoospermia is required for effective hormonal male contraception, but the degree of suppression varies between ethnic groups. We here report the first study of hormonal suppression of spermatogenesis in two African centres using a regimen of oral progestogen with depot testosterone. METHODS A total of 31 healthy men (21 black) were recruited in Cape Town and 21 men in Sagamu, Nigeria. Subjects were randomized to take either 150 or 300 micro g desogestrel daily p.o. with testosterone pellets. In Cape Town, desogestrel was administered for 24 weeks with 400 mg testosterone re-administered 12 weekly. In Sagamu, desogestrel was administered for 52 weeks with 200 mg testosterone (later increased to 400 mg) re-administered 12-weekly.

RESULTS

In Cape Town, 22 men completed at least 20 weeks treatment. Azoospermia was achieved in 8/10 and 8/12 men in the 150 micro g and 300 micro g desogestrel groups. Four men in Sagamu withdrew. Azoospermia was achieved in all 17 men in the two groups. There were no significant changes in lipoprotein or haemoglobin concentrations in any group.

CONCLUSION

These data demonstrate that the combination of oral desogestrel with depot testosterone is an effective regimen for suppression of spermatogenesis in African as in Caucasian and Chinese men, with azoospermia achieved in a total of 83/98 (85%) men.

Investigation of a novel preparation of testosterone decanoate in men: pharmacokinetics and spermatogenic suppression with etonogestrel implants

We have investigated the pharmacokinetics and effects on the male reproductive axis of a novel preparation of testosterone decanoate (TD) with a progestogen implant. Twenty healthy Chinese men were administered TD (400 mg intramuscular 4 weekly) with two subcutaneous (SC) etonogestrel implants. Trough testosterone concentrations rose with repeated administration. Peak concentrations 1 week after the fourth injection were 31 +/- 2 nmol/liter. Both LH and FSH were rapidly suppressed and continued to fall during treatment. Spermatogenesis was also suppressed, to <or=1 x 10(6)/mL in all men with 16 (80%) azoospermic at 12 weeks. Treatment was associated with an increase in weight, and also increases in hemoglobin concentration (9%) and hematocrit (15%). No subjects withdrew from the study, although the study was terminated after subjects had completed 12 to 18 weeks as some men were found to have elevated liver enzyme tests. These data demonstrate that the pharmacokinetics of TD are improved compared to previous injectable testosterone preparations, although peak testosterone concentrations rise briefly into the supraphysiological range. The speed and degree of spermatogenic suppression suggest that this combination has promise as an effective male contraceptive.

Mandelic acid condensation polymer: novel candidate microbicide for prevention of human immunodeficiency virus and herpes simplex virus entry

Presently marketed vaginal barrier methods are cytotoxic and damaging to the vaginal epithelium and natural vaginal flora when used frequently. Novel noncytotoxic agents are needed to protect men and women from sexually transmitted diseases. One novel candidate is a mandelic acid condensation polymer, designated SAMMA. The spectrum and mechanism of antiviral activity were explored using clinical isolates and laboratory-adapted strains of human immunodeficiency virus (HIV) and herpes simplex virus (HSV). SAMMA is highly effective against all CCR5 and CXCR4 isolates of HIV in primary human macrophages and peripheral blood mononuclear cells. SAMMA also inhibits infection of cervical epithelial cells by HSV. Moreover, it exhibits little or no cytotoxicity and has an excellent selectivity index. SAMMA, although not a sulfonated or sulfated polymer, blocks the binding of HIV and HSV to cells by targeting the envelope glycoproteins gp120 and gB-2, respectively, and also inhibits HSV entry postattachment. SAMMA is an excellent, structurally novel candidate microbicide that warrants further preclinical evaluation.

Biomarkers of exposure to cyanogens in horses with grass sickness

To test the hypothesis that equine grass sickness may be associated with the ingestion of cyanogenic glycosides from white clover (Trifolium repens), the concentrations of whole blood cyanide, and plasma and urinary thiocyanate, the main metabolite of cyanide, were measured in 12 horses with acute grass sickness and 10 horses with subacute grass sickness, and in 43 control horses, of which 21 were co-grazing with cases of acute grass sickness, 12 grazed pastures where grass sickness had not been reported, and 10 were stabled horses. The healthy horses which grazed with cases of acute grass sickness had higher concentrations of blood cyanide, and plasma and urinary thiocyanate than the other control horses, consistent with an increased exposure to cyanogens. The horses with grass sickness had no evidence of a recent intake of cyanogens, but may have been exposed to increased levels of cyanogens before they became anorexic.

Suppression of spermatogenesis by etonogestrel implants with depot testosterone: potential for long-acting male contraception

The coadministration of a progestogen with testosterone increases the degree of suppression of spermatogenesis and is one approach to the development of hormonal male contraception. Depot formulations may allow a reduction in dosage, minimizing adverse effects. We have investigated the effects of a sc implant containing the progestogen etonogestrel (Implanon) with depot testosterone on spermatogenesis in normal men. Twenty-eight men were randomized to receive either one or two etonogestrel implants, removed after 24 wk. All men additionally received 400 mg testosterone pellets on d 1 and at 12 wk. Four men withdrew during the study, three because of side effects. Testosterone concentrations remained within the physiological range during treatment, although they were overall slightly reduced, compared with pretreatment. Both groups showed marked suppression of spermatogenesis, nine men in each group achieving azoospermia (64% and 75% in the one- and two-implant groups, respectively). Sperm concentrations in 13/14 men in the two-implant group fell to 0.1 x 10(6)/ml or less. Spermatogenic suppression was more variable in the one-implant group, with partial recovery in three men. Incomplete suppression of spermatogenesis in the one-implant group was associated with less complete suppression of gonadotropins. There were no significant changes in body weight, hemoglobin, hematocrit, or high-density lipoprotein cholesterol concentrations during treatment. These data demonstrate that etonogestrel implants with depot testosterone provide effective suppression of spermatogenesis with reduced metabolic effects and are, therefore, a promising approach to the development of long-acting yet reversible male contraception.

Investigation of suppression of the hypothalamic-pituitary-gonadal axis to restore spermatogenesis in azoospermic men treated for childhood cancer

BACKGROUND

Does suppression of the hypothalamic-pituitary-gonadal (HPG) axis restore spermatogenesis in men rendered azoospermic following treatment of childhood cancer?

METHODS

Seven men with azoospermia secondary to treatment for childhood cancer, median age (range), 22.2 (18-25.3) years, aged 10.4 (4.4-13.3) years at original diagnosis, participated. Each subject underwent semen analysis and testicular biopsy, followed by treatment with medroxyprogesterone acetate (MPA), 300 mg i.m. repeated after 12 weeks, with 800 mg testosterone pellets s.c. on day 1 to suppress the HPG axis. Hormone and semen analysis was performed every 6 weeks for 48 weeks. A second testicular biopsy was performed at week 48.

RESULTS

Before HPG axis suppression, mean +/- SEM plasma LH was 9.0 +/- 1.8 U/l, testosterone 17.9 +/- 1.5 nmol/l and FSH 22.4 +/- 4.4 U/l. Median (range) venous plasma and seminal plasma inhibin B levels were 10.0 (7.8-35) and 11.2 (7.8-770) ng/l respectively. During HPG suppression, FSH and LH levels were undetectable for > or =12 weeks followed by a gradual return to pretreatment concentrations by 48 weeks. All men remained azoospermic at study completion and complete absence of germ cells on biopsies was demonstrated by immunocytochemistry for all specimens pre- and post-HPG axis suppression.

CONCLUSIONS

HPG axis suppression with MPA-testosterone for > or =12 weeks did not restore spermatogenesis in azoospermic men treated with gonadotoxic radiotherapy and chemotherapy for childhood cancer.

Developmental changes in expression of myeloid cell leukemia-1 in human germ cells during oogenesis and early folliculogenesis

The regulation of germ cell number in the developing ovary is central to female reproduction. Members of the Bcl-2 family of proapoptotic and antiapoptotic proteins have been implicated in this process in rodents. We investigated the expression of Mcl-1, Bcl-2, Bax, and BAD at 13-21 gestational wk in the human fetal ovary and of Mcl-1 in the adult ovary. mRNA expression of Mcl-1 and its short form Mcl-1s, Bcl-2, Bax, and BAD was demonstrated in fetal ovary by RT-PCR. Hybridization array analysis suggested a selective increase in Mcl-1 expression between 14 and 18 wk gestation, which was confirmed by quantitative PCR. There was a corresponding change in the expression of Mcl-1 protein, detected by immunohistochemistry, from germ cells at the periphery of the ovary at 14-16 wk to the largest germ cells, including oocytes within newly formed primordial follicles, at 21 wk. Mcl-1 was also expressed by oocytes of primordial and preantral follicles in the adult. Bax and BAD immunostaining was detected in both somatic and germ cells in the fetal ovary, whereas Bcl-2 was restricted to somatic cells: no changes in expression were observed. Apoptotic cells, detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling, were observed in all fetal ovaries but were infrequent. These results confirm that Bcl-2 family members are differentially expressed in several cell types within the developing human ovary. Increased mRNA expression and the changing distribution of Mcl-1 in germ cells as they develop into primordial follicles as well as persistence in the growing oocyte in the adult may indicate an important role for this survival/antiapoptotic factor throughout germ cell development and maturation.

Oral desogestrel with testosterone pellets induces consistent suppression of spermatogenesis to azoospermia in both Caucasian and Chinese men

BACKGROUND

Effective hormonal male contraception requires a high prevalence of spermatogenic suppression, which has proved particularly difficult in Caucasian populations. We have investigated the combination of oral desogestrel with depot testosterone in Caucasian and Chinese men.

METHOD

Thirty men in Edinburgh and 36 men in Shanghai received 150 or 300 microg desogestrel p.o. daily for 24 weeks with 400 mg testosterone pellets s.c. on day 1 and at 12 weeks.

RESULTS

Eight men withdrew before completing 24 weeks treatment. Testosterone concentrations remained within the normal range. Spermatogenesis was profoundly suppressed in all men. Azoospermia was achieved by a higher proportion of men in the 300 microg desogestrel group: 28/28 men versus 22/31 men (P < 0.05). All Caucasian men in the 150 microg group achieved sperm concentrations of < 1 x 10(6)/ml whereas three men in the Shanghai group maintained sperm concentrations of > 3 x 10(6)/ml. Fifteen men continued on this regimen for a subsequent 24 weeks: all remained azoospermic for the duration of treatment. High-density lipoprotein cholesterol fell by 15% in Caucasian men, but was unchanged in the Chinese men; both groups showed some weight gain.

CONCLUSION

This combination of oral desogestrel with depot testosterone maintains physiological testosterone concentrations with consistent suppression of spermatogenesis to azoospermia in both Caucasian and Chinese men and therefore has many of the properties necessary for a contraceptive preparation for men.

Expression and localization of inhibin alpha, inhibin/activin betaA and betaB and the activin type II and inhibin beta-glycan receptors in the developing human testis

Inhibins and activins have roles in the regulation of cell proliferation and differentiation in a variety of tissues. This study investigated the distribution of the three inhibin/activin subunits (alpha, betaA and betaB) and their receptors in the human testis between week 13 and week 19 of gestation using RT-PCR and immunohistochemistry. mRNA for all three subunits and for the activin type II receptors ActRIIA and ActRIIB was detected at all stages of gestation examined. Sertoli cells showed intense immunostaining for the alpha subunit and some staining for the betaB subunit, whereas only the betaB subunit was detected in gonocytes. No betaA subunit staining was detected within the tubules. All three subunits were localized to interstitial Leydig cells. Cells of the rete testis and the epididymal epithelium also showed immunostaining for betaB; however, staining for the other subunits was weak or absent. Peritubular cells showed intense immunostaining for the beta-glycan inhibin receptor, which was also localized to interstitial cells, but was not detected within the tubular compartment, rete testis or epididymal epithelium. ActRIIA was detected in gonocytes and in interstitial cells; ActRIIB was distributed widely. These data indicate that fetal Leydig and Sertoli cells have the potential to produce both activins and inhibins, whereas gonocytes may produce only activin B. The distribution of activin and inhibin receptors implies that the intratubular compartment and developing duct system are sites of action of activin B but not inhibin at this stage of development, whereas both activins and inhibins may be involved in the development and function of the peritubular and interstitial cells.

Papillomavirus microbicidal activities of high-molecular-weight cellulose sulfate, dextran sulfate, and polystyrene sulfonate

The high-molecular-weight sulfated or sulfonated polysaccharides or polymers cellulose sulfate, dextran sulfate, and polystyrene sulfonate were tested for microbicidal activity against bovine papillomavirus type 1 (BPV-1) and human papillomavirus type 11 (HPV-11) and type 40 (HPV-40). In vitro assays included the BPV-1-induced focus-forming assay and transient infection of human A431 cells with HPVs. The compounds were tested for microbicidal activity directly by preincubation with virus prior to addition to cell cultures and indirectly by addition of virus to compound-treated cells and to virus-coated cells to test inactivation of the virus after virus-cell binding. The data indicated that all three compounds showed direct microbicidal activity with 50% effective concentrations between 10 to 100 microg/ml. These concentrations were nontoxic to cell cultures for both assays. When a clone of C127 cells was tested for microbicidal activity, approximately 10-fold-less compound was required to achieve a 50% reduction in BPV-1-induced foci than for the uncloned parental C127 cells. Pretreatment of cells with compound prior to addition of virus also demonstrated strong microbicidal activity with dextran sulfate and polystyrene sulfonate, but cellulose sulfate required several orders of magnitude more compound for virus inactivation. Polystyrene sulfonate prevented subsequent infection of HPV-11 after virus-cell binding, and this inactivation was observed up to 4 h after addition of virus. These data indicate that the polysulfated and polysulfonated compounds may be useful nontoxic microbicidal compounds that are active against a variety of sexually transmitted disease agents including papillomaviruses.

EDTA chelation effects on urinary losses of cadmium, calcium, chromium, cobalt, copper, lead, magnesium, and zinc

The efficacy of a chelating agent in binding a given metal in a biological system depends on the binding constants of the chelator for the particular metals in the system, the concentration of the metals, and the presence and concentrations of other ligands competing for the metals in question. In this study, we make a comparison of the in vitro binding constants for the chelator, ethylenediaminetetraacetic acid, with the quantitative urinary excretion of the metals measured before and after EDTA infusion in 16 patients. There were significant increases in lead, zinc, cadmium, and calcium, and these increases roughly corresponded to the expected relative increases predicted by the EDTA-metal-binding constants as measured in vitro. There were no significant increases in urinary cobalt, chromium, or copper as a result of EDTA infusion. The actual increase in cobalt could be entirely attributed to the cobalt content of the cyanocobalamin that was added to the infusion. Although copper did increase in the post-EDTA specimens, the increase was not statistically significant. In the case of magnesium, there was a net retention of approximately 85% following chelation. These data demonstrate that EDTA chelation therapy results in significantly increased urinary losses of lead, zinc, cadmium, and calcium following EDTA chelation therapy. There were no significant changes in cobalt, chromium, or copper and a retention of magnesium. These effects are likely to have significant effects on nutrient concentrations and interactions and partially explain the clinical improvements seen in patients undergoing EDTA chelation therapy.

Effects of a high polyunsaturated fat diet and vitamin E supplementation on high-density lipoprotein oxidation in humans

Oxidative modification of high-density lipoproteins (HDL) impairs several biologic functions critical to its role in reverse cholesterol transport. We therefore investigated the effect of dietary polyunsaturated fat and vitamin E on the kinetics of HDL oxidation. Ten subjects were fed sequentially: a baseline diet in which the major fat source was olive oil; a high polyunsaturated fat diet in which the major fat source was safflower oil; and the safflower oil diet plus 800 I.U. vitamin E per day. Plasma lipoprotein levels, vitamin E content, fatty acid composition, and oxidation lag time and rate were determined after 3 weeks on each diet. The polyunsaturated fat diet increased the mean HDL(2) lag time from 45.8+/-12.5 to 83.3+/-11.6 min with no change in oxidation rate. Addition of vitamin E further increased the HDL(2) lag time to 115.6+/-4.4 min and decreased the HDL(2) oxidation rate 10-fold. Neither the polyunsaturated diet alone nor the diet with vitamin E supplementation had any effect on HDL(3) oxidation. We conclude that under conditions of controlled dietary fat intake, a high polyunsaturated fat intake does not increase the oxidation susceptibility of HDL subfractions, and that in this setting, vitamin E supplementation reduces the oxidation susceptibility of HDL(2). These data suggest that antioxidants could influence HDL function in vivo.

Is the fatty meal a trigger for acute coronary syndromes

This hypothesis paper aims to illustrate the role of fatty meal ingestion has on the vascular endothelium and coagulation system. In particular highlighting the potential risk of fatty meal ingestion both as a trigger to an adverse factor in patients with acute coronary syndromes. We propose that as a result of ingesting fatty meals as a part of daily living, there occurs a constellation of changes in the vasculature that results in both a hypercoagulable and a provasoconstrictor state. These acute changes in response to a fatty meal on endothelial function, prothrombosis, and platelet activation can potentially trigger, facilitate and propagate the forces that drive acute coronary syndromes. In type 2 diabetes, adverse postprandial phenomena are exaggerated and prolonged and may therefore be expected to contribute significantly to the excess risk of acute coronary syndromes and atherosclerotic development in these subjects.

Intensity of case managers' participation in organizational decision making

Prior research has indicated that registered nurse (RN) participation in decision making (PDM) is related to better outcomes in nursing homes and hospitals. Little is known, however, about the roles of community-based case managers (CMs), most of whom are RNs. Data from 68 prenatal case management programs were used to test hypotheses about the intensity of CM PDM and to describe their patterns of involvement in decision activities and mechanisms. CMs were most involved in the activity of "raising the issue" and least involved in "choosing the alternative." However, "choosing the alternative" was the strongest predictor of perceived CM influence over the final choice. When CMs were involved in informal meetings and chance encounters with administrators, they were more likely to be perceived as having influence over the final choices made. Intensity of CM PDM varied by decision level and content, supporting two of the three hypotheses. The findings are discussed in light of prior research and complexity theory.

Expression of COX-2 and PGE synthase and synthesis of PGE(2)in endometrial adenocarcinoma: a possible autocrine/paracrine regulation of neoplastic cell function via EP2/EP4 receptors

This study was designed to investigate the possible role of cyclo-oxygenase-2 (COX-2) and prostaglandin E(2)(PGE(2)) in endometrial adenocarcinoma. COX-2 RNA expression was confirmed in various grades of adenocarcinoma by ribonuclease protection assay. COX-2 and microsomal glutathione-dependent prostaglandin E synthase (mPGES) expression and PGE(2)synthesis were localised to the neoplastic epithelial cells and endothelial cells. In order to establish whether PGE(2)has an autocrine/paracrine effect in adenocarcinomas, we investigated the expression of 2 subtypes of PGE(2)receptors, namely EP2 and EP4, by real time quantitative PCR. Expression of EP2 and EP4 receptors was detected in adenocarcinomas from all grades of differentiation and was significantly higher than that detected in normal secretory phase endometrium (P< 0.01). The fold induction of expression in adenocarcinoma compared with normal secretory phase endometrium was 28.0 +/- 7.4 and 52.5 +/- 10.1 for EP2 and EP4 receptors respectively. Immunohistochemistry localised the site of expression of EP4 receptor in neoplastic epithelial cells and in the endothelium of carcinomas of all grades of differentiation. Finally, the functionality of the EP2/EP4 receptors was assessed by investigating cAMP generation following in vitro culture of adenocarcinoma tissue in the presence or absence of 300 nM PGE(2). cAMP production in response to PGE(2)was significantly higher in carcinoma tissue than that detected in normal secretory phase endometrium (3.42 +/- 0.46 vs 1.15 +/- 0.05 respectively; P< 0.001). In conclusion, these data suggest that PGE(2)may regulate neoplastic cell function in an autocrine/paracrine manner via the EP2/EP4 receptors.

Hypothalamic-pituitary-ovarian dysfunction after prepubertal chemotherapy and cranial irradiation for acute leukaemia

BACKGROUND

We assessed adult hypothalamic-pituitary-ovarian function following treatment with chemotherapy and cranial irradiation for childhood acute lymphoblastic leukaemia.

METHODS

The patients (n = 12) had median age at diagnosis of 4.7 years, and at assessment of 20.8 years. They collected a daily urine sample over two to five consecutive menstrual cycles (total of 41 cycles) for analysis of LH and steroid excretion. Blood sampling and ovarian ultrasound examination was performed in the early follicular phase. Sixteen healthy women with regular menstrual cycles were recruited as controls.

RESULTS

Urinary LH excretion was significantly lower in patients throughout the cycle, particularly during the LH surge (P < 0.0001). The length of the luteal phase was significantly shorter in patients than in normal controls (12.2 +/- 0.3 versus 13.6 +/- 0.4 days, P = 0.01) with a high prevalence of short (< or =11 days) luteal phases (15/39 cycles). Luteal phase pregnanediol excretion was slightly but not significantly lower. Follicular and luteal phase excretion of oestrone was lower in patients than in controls (P = 0.01). Early follicular phase plasma oestradiol was also lower in the patient group (P = 0.032) although LH, FSH, inhibin A and B concentrations were similar.

CONCLUSIONS

These data indicate that treatment for childhood leukaemia results in subtle ovulatory disorder in some patients, probably related to cranial irradiation. Follow-up of these women is required to detect any effect on reproductive potential.