An unsupervised learning approach to identify immunoglobulin utilization patterns using electronic health records.

BACKGROUND: Managing Canada's immunoglobulin (Ig) product resource allocation is challenging due to increasing demand, high expenditure, and global shortages. Detection of groups with high utilization rates can help with resource planning for Ig products. This study aims to uncover utilization subgroups among the Ig recipients using electronic health records (EHRs). METHODS: The study included all Ig recipients (intravenous or subcutaneous) in Calgary from 2014 to 2020, and their EHR data, including blood inventory, recipient demographics, and laboratory test results, were analyzed. Patient clusters were derived based on patient characteristics and laboratory test data using K-means clustering. Clusters were interpreted using descriptive analyses and visualization techniques. RESULTS: Among 4112 recipients, six clusters were identified. Clusters 1 and 2 comprised 408 (9.9%) and 1272 (30.9%) patients, respectively, contributing to 62.2% and 27.1% of total Ig utilization. Cluster 3 included 1253 (30.5%) patients, with 86.4% of infusions administered in an inpatient setting. Cluster 4, comprising 1034 (25.1%) patients, had a median age of 4 years, while clusters 2-6 were adults with median ages of 46-60. Cluster 5 had 62 (1.5%) patients, with 77.3% infusions occurring in emergency departments. Cluster 6 contained 83 (2.0%) patients receiving subcutaneous Ig treatments. CONCLUSION: The results identified data-driven segmentations of patients with high Ig utilization rates and patients with high risk for short-term inpatient use. Our report is the first on EHR data-driven clustering of Ig utilization patterns. The findings hold the potential to inform demand forecasting and resource allocation decisions during shortages of Ig products.

Modulation of the anticonvulsant effect of swim stress by agmatine.

Agmatine is an endogenous l-arginine metabolite with neuroprotective effects in the stress-response system. It exerts anticonvulsant effects against several seizure paradigms. Swim stress induces an anticonvulsant effect by activation of endogenous antiseizure mechanisms. In this study, we investigated the interaction of agmatine with the anticonvulsant effect of swim stress in mice on pentylenetetrazole (PTZ)-induced seizure threshold. Then we studied the involvement of nitric oxide (NO) pathway and endogenous opioid system in that interaction. Swim stress induced an anticonvulsant effect on PTZ seizures which was opioid-independent in shorter than 1-min swim durations and opioid-dependent with longer swims, as it was completely reversed by pretreatment with naltrexone (NTX) (10mg/kg), an opioid receptor antagonist. Agmatine significantly enhanced the anticonvulsant effect of opioid-independent shorter swim stress, in which a combination of subthreshold swim stress duration (45s) and subeffective dose of agmatine (1mg/kg) revealed a significantly higher seizure threshold compared with either one. This effect was significantly reversed by NO synthase inhibitor NG-nitro-l-arginine (L-NAME (Nω-Nitro-L-arginine methyl ester), 5mg/kg), suggesting an NO-dependent mechanism, and was unaffected by NTX (10mg/kg), proving little role for endogenous opioids in the interaction. Our data suggest that pretreatment of animals with agmatine acts additively with short swim stress to exert anticonvulsant responses, possibly by mediating NO pathway.

Microglia-dependent alteration of glutamatergic synaptic transmission and plasticity in the hippocampus during peripheral inflammation.

Peripheral inflammatory diseases are often associated with behavioral comorbidities including anxiety, depression, and cognitive dysfunction, but the mechanism for these is not well understood. Changes in the neuronal and synaptic functions associated with neuroinflammation may underlie these behavioral abnormalities. We have used a model of colonic inflammation induced by 2,4,6-trinitrobenzenesulfonic acid in Sprague Dawley rats to identify inflammation-induced changes in hippocampal synaptic transmission. Hippocampal slices obtained 4 d after the induction of inflammation revealed enhanced Schaffer collateral-induced excitatory field potentials in CA1 stratum radiatum. This was associated with larger-amplitude mEPSCs, but unchanged mEPSC frequencies and paired-pulse ratios, suggesting altered postsynaptic effects. Both AMPA- and NMDA-mediated synaptic currents were enhanced, and analysis of AMPA-mediated currents revealed increased contributions of GluR2-lacking receptors. In keeping with this, both transcripts and protein levels of the GluR2 subunit were reduced in hippocampus. Both long-term potentiation (LTP) and depression (LTD) were significantly reduced in hippocampal slices taken from inflamed animals. Chronic administration of the microglial/macrophage activation inhibitor minocycline to the inflamed animals both lowered the level of the cytokine tumor necrosis factor α in the hippocampus and completely abolished the effect of peripheral inflammation on the field potentials and synaptic plasticity (LTP and LTD). Our results reveal profound synaptic changes caused by a mirror microglia-mediated inflammatory response in hippocampus during peripheral organ inflammation. These synaptic changes may underlie the behavioral comorbidities seen in patients.

P-selectin-mediated monocyte-cerebral endothelium adhesive interactions link peripheral organ inflammation to sickness behaviors.

Sickness behaviors, such as fatigue, mood alterations, and cognitive dysfunction, which result from changes in central neurotransmission, are prevalent in systemic inflammatory diseases and greatly impact patient quality of life. Although, microglia (resident cerebral immune cells) and cytokines (e.g., TNFα) are associated with changes in central neurotransmission, the link between peripheral organ inflammation, circulating cytokine signaling, and microglial activation remains poorly understood. Here we demonstrate, using cerebral intravital microscopy, that in response to liver inflammation, there is increased monocyte specific rolling and adhesion along cerebral endothelial cells (CECs). Peripheral TNFα-TNFR1 signaling and the adhesion molecule P-selectin are central mediators of these monocyte-CEC adhesive interactions which were found to be closely associated with microglial activation, decreased central neural excitability and sickness behavior development. Similar monocyte-CEC adhesive interactions were also observed in another mouse model of peripheral organ inflammation (i.e., 2,4-dinitrobenzene sulfonic acid-induced colitis). Our observations provide a clear link between peripheral organ inflammation and cerebral changes that impact behavior, which can potentially allow for novel therapeutic interventions in patients with systemic inflammatory diseases.

Cytokines and brain excitability.

Cytokines are molecules secreted by peripheral immune cells, microglia, astrocytes and neurons in the central nervous system. Peripheral or central inflammation is characterized by an upregulation of cytokines and their receptors in the brain. Emerging evidence indicates that pro-inflammatory cytokines modulate brain excitability. Findings from both the clinical literature and from in vivo and in vitro laboratory studies suggest that cytokines can increase seizure susceptibility and may be involved in epileptogenesis. Cellular mechanisms that underlie these effects include upregulation of excitatory glutamatergic transmission and downregulation of inhibitory GABAergic transmission.

Increased excitability and molecular changes in adult rats after a febrile seizure.

Both early life inflammation and prolonged febrile seizures have been associated with increased excitation in the adult brain. We hypothesized this may be due in part to changes in the cation-chloride cotransporter system. Rat pups received saline or lipopolysaccharide/kainic acid (LPS/KA) resulting in inflammation, followed by a behavioral febrile seizure (FS) in approximately 50% of rats. Adult animals from the saline, inflammation, or inflammation + FS groups underwent the following: (1) in vitro electrophysiologic studies; (2) Western blotting or polymerase chain reaction; or (3) application of the Na-K-Cl cotransporter 1 (NKCC1) blocker bumetanide to determine its effect on reversing increased excitability in vitro. The inflammation and inflammation + FS groups demonstrated increased excitability in vitro and increased hippocampal protein expression of NR2B and GABAA α5 receptor subunits and mRNA expression of NKCC1. The inflammation + FS group also had decreased protein expression of GluR2 and GABAA α1 receptor subunits and mRNA and protein expression of KCC2. Bumetanide decreased in vitro 4-aminopyridine-induced inter-ictal activity in the inflammation and inflammation + FS groups. The results demonstrate early-life inflammation with or without a behavioral FS can lead to long-lasting molecular changes and increased excitability in the adult rat hippocampus, although some changes are more extensive when inflammation is accompanied by behavioral seizure activity. Bumetanide is effective in reversing increased excitability in vitro, providing evidence for a causal role for cation-chloride cotransporters and suggesting this drug may prove useful for treating epilepsy that develops after a FS.

Immunoglobulin utilization in Canada: a comparative analysis of provincial guidelines and a scoping review of the literature.

BACKGROUND: Canada has high immunoglobulin (IG) product utilization, raising concerns about appropriate utilization, cost and risk of shortages. Currently, there is no national set of standardized IG guidelines, and considerable variations exist among the existing provincial guidelines. The aims of this study were: (1) to compare the existing Canadian provincial guidelines on the use of IG products to identify their consistencies and differences and (2) to examine the existing research in Canada on IG supply and utilization following the establishment of IG guidelines to understand the scope of research and pinpoint the gaps. METHODS: A comparative analysis accounted for the differences across provincial IG guidelines. We highlighted similarities and differences in recommendations for medical conditions. A scoping review of citations from MEDLINE, PubMed, Scopus and Embase databases was conducted for studies published from January 01, 2014, to April 12, 2023. RESULTS: While provincial guidelines represented a considerable overlap in the medical conditions delineated and relatively uniform dose calculations, numerous differences were observed, including in recommendation categories, provision of pediatric dosing, and divergent recommendations for identical conditions based on patient demographics. The scoping review identified 29 studies that focused on the use of IG in Canada. The themes of the studies included: IVIG utilization and audits, the switch from IVIG to SCIG, patient satisfaction with IVIG and/or SCIG, the economic impact of self-administered SCIG versus clinically administered IVIG therapy, and the efficacy and cost-effectiveness of alternative medications to IG treatment. CONCLUSION: The differences in guidelines across provinces and the factors influencing IVIG/SCIG use, patient satisfaction, and cost savings are highlighted. Future research may focus on clarifying costs and comparative effectiveness, exploring factors influencing guideline adherence, and evaluating the impact of updated guidelines on IG use and patient outcomes.

Race and Ethnicity in Non-Alcoholic Fatty Liver Disease (NAFLD): A Narrative Review.

Non-alcoholic fatty liver disease (NAFLD) is a significant public health concern worldwide with a complex etiology attributed to behavioural, environmental, and genetic causes. The worldwide prevalence of NAFLD is estimated to be 32.4% and constantly rising. Global data, however, indicate considerable heterogeneity among studies for both NAFLD prevalence and incidence. Identifying variables that affect the estimated epidemiological measures is essential to all stakeholders, including patients, researchers, healthcare providers, and policymakers. Besides helping with the research on disease etiology, it helps to identify individuals at risk of the disease, which in turn will outline the focus of the preventive measures and help to fittingly tailor individualized treatments, targeted prevention, screening, or treatment programs. Several studies suggest differences in the prevalence and severity of NAFLD by race or ethnicity, which may be linked to differences in lifestyle, diet, metabolic comorbidity profile, and genetic background, among others. Race/ethnicity research is essential as it can provide valuable information regarding biological and genetic differences among people with similar cultural, dietary, and geographical backgrounds. In this review, we examined the existing literature on race/ethnicity differences in susceptibility to NAFLD and discussed the contributing variables to such differences, including diet and physical activity, the comorbidity profile, and genetic susceptibility. We also reviewed the limitations of race/ethnicity studies in NAFLD.

The prevalence and incidence of NAFLD worldwide: a systematic review and meta-analysis.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide and the leading cause of liver-related morbidity and mortality. We aimed to predict the burden of NAFLD by examining and estimating the temporal trends of its worldwide prevalence and incidence. METHODS: In this systematic review and meta-analysis, we searched MEDLINE, EMBASE, Scopus, and Web of Science without language restrictions for reports published between date of database inception and May 25, 2021. We included observational cross-sectional or longitudinal studies done in study populations representative of the general adult population, in whom NAFLD was diagnosed using an imaging method in the absence of excessive alcohol consumption and viral hepatitis. Studies were excluded if conducted in paediatric populations (aged <18 years) or subgroups of the general population. Summary estimates were extracted from included reports by KR and independently verified by HA using the population, intervention, comparison, and outcomes framework. Primary outcomes were the prevalence and incidence of NAFLD. A random-effects meta-analysis was used to calculate overall and sex-specific pooled effect estimates and 95% CIs. FINDINGS: The search identified 28 557 records, of which 13 577 records were screened; 299 records were also identified via other methods. In total, 72 publications with a sample population of 1 030 160 individuals from 17 countries were included in the prevalence analysis, and 16 publications with a sample population of 381 765 individuals from five countries were included in the incidence analysis. The overall prevalence of NAFLD worldwide was estimated to be 32·4% (95% CI 29·9-34·9). Prevalence increased significantly over time, from 25·5% (20·1-31·0) in or before 2005 to 37·8% (32·4-43·3) in 2016 or later (p=0·013). Overall prevalence of NAFLD was significantly higher in men than in women (39·7% [36·6-42·8] vs 25·6% [22·3-28·8]; p<0·0001). The overall incidence of NAFLD was estimated to be 46·9 cases per 1000 person-years (36·4-57·5); 70·8 cases per 1000 person-years (48·7-92·8) in men and 29·6 cases per 1000 person-years (20·2-38·9) in women (p<0·0001). There was considerable heterogeneity between studies of both NAFLD prevalence (I2=99·9%) and NAFLD incidence (I2=99·9%). INTERPRETATION: Worldwide prevalence of NAFLD is considerably higher than previously estimated and is continuing to increase at an alarming rate. Incidence and prevalence of NAFLD are significantly higher among men than among women. Greater awareness of NAFLD and the development of cost-effective risk stratification strategies are warranted to address the growing burden of NAFLD. FUNDING: Canadian Institutes of Health.

Microglial activation and TNFalpha production mediate altered CNS excitability following peripheral inflammation.

Peripheral inflammation leads to a number of centrally mediated physiological and behavioral changes. The underlying mechanisms and the signaling pathways involved in these phenomena are not yet well understood. We hypothesized that peripheral inflammation leads to increased neuronal excitability arising from a CNS immune response. We induced inflammation in the gut by intracolonic administration of 2,4,6-trinitrobenzene sulfonic acid (TNBS) to adult male rats. To examine the excitability of the brain in vivo, we administered pentylenetetrazole (PTZ; a GABAergic antagonist) intravenously to evoke clonic seizures. Rats treated with TNBS showed increased susceptibility to PTZ seizures that was strongly correlated with the severity and progression of intestinal inflammation. In vitro hippocampal slices from inflamed, TNBS-treated rats showed increased spontaneous interictal burst firing following application of 4-aminopyridine, indicating increased intrinsic excitability. The TNBS-treated rats exhibited a marked, reversible inflammatory response within the hippocampus, characterized by microglial activation and increases in tumor necrosis factor alpha (TNFalpha) levels. Central antagonism of TNFalpha using a monoclonal antibody or inhibition of microglial activation by i.c.v. injection of minocycline prevented the increase in seizure susceptibility. Moreover, i.c.v. infusion of TNFalpha in untreated rats for 4 days also increased seizure susceptibility and thus mimicked the changes in seizure threshold observed with intestinal inflammation. Our finding of a microglia-dependent TNFalpha-mediated increase in CNS excitability provides insight into potential mechanisms underlying the disparate neurological and behavioral changes associated with chronic inflammation.

Risk stratification of patients with nonalcoholic fatty liver disease using a case identification pathway in primary care: a cross-sectional study.

BACKGROUND: Identification of patients with nonalcoholic fatty liver disease (NAFLD) with advanced liver fibrosis in primary care remains an unmet need. Our primary objective was to implement a pathway driven by shear wave elastography (SWE) to facilitate risk stratification of patients with NAFLD within primary care and evaluate whether SWE assessment can reduce referrals of patients with NAFLD at low risk for fibrosis to hepatology. METHODS: A multidisciplinary NAFLD clinical care pathway was codeveloped by hepatologists, radiologists and primary care physicians in Calgary to provide access to SWE-based screening of patients with NAFLD risk factors in primary care. The study outcome measures were estimated NAFLD-related referrals to the hepatology service in Calgary after implementation of the NAFLD pathway and characteristics of patients with NAFLD at risk for advanced fibrosis. The NAFLD pathway was implemented in January 2018 and was made available to all primary care physicians in the Calgary Health Zone. Patients with NAFLD who had liver stiffness (SWE value ≥ 8.0 kPa) or an inconclusive assessment were referred to hepatology. A serum liver fibrosis score was also measured with the fibrosis-4 (FIB-4) index, and performance of an FIB-4 index score of 1.30 or greater to risk stratify patients with NAFLD was evaluated. Demographic, clinical and laboratory characteristics of study groups were compared. RESULTS: Between March and October 2018, 2084 patients with suspected NAFLD were evaluated. Nonalcoholic fatty liver disease was confirmed by ultrasonography in 1958 (94.1%). A majority of the cohort had elevated liver enzyme values (1028 [52.5%]) and obesity (body mass index ≥ 30) (1063/1764 [60.3%]). Most patients with NAFLD (1791 [91.5%]) had an SWE value less than 8.0 kPa and were not referred to hepatology. Sixty-seven patients (3.4%) had an SWE value of 8.0 kPa or more, and 100 (5.1%) had an inconclusive SWE; these patients were referred to hepatology. Using an FIB-4 index score cut-off of 1.30 would have led to hepatology referral of 396/1251 patients (31.6%). INTERPRETATION: Implementation of a primary care-accessible SWE pathway for patients with NAFLD facilitated fibrosis risk stratification and greatly reduced hepatology referrals. Using the FIB-4 index score alone would led to higher rates of referral of patients with NAFLD.

Postnatal inflammation increases seizure susceptibility in adult rats.

There are critical postnatal periods during which even subtle interventions can have long-lasting effects on adult physiology. We asked whether an immune challenge during early postnatal development can alter neuronal excitability and seizure susceptibility in adults. Postnatal day 14 (P14) male Sprague Dawley rats were injected with the bacterial endotoxin lipopolysaccharide (LPS), and control animals received sterile saline. Three weeks later, extracellular recordings from hippocampal slices revealed enhanced field EPSP slopes after Schaffer collateral stimulation and increased epileptiform burst-firing activity in CA1 after 4-aminopyridine application. Six to 8 weeks after postnatal LPS injection, seizure susceptibility was assessed in response to lithium-pilocarpine, kainic acid, and pentylenetetrazol. Rats treated with LPS showed significantly greater adult seizure susceptibility to all convulsants, as well as increased cytokine release and enhanced neuronal degeneration within the hippocampus after limbic seizures. These persistent increases in seizure susceptibility occurred only when LPS was given during a critical postnatal period (P7 and P14) and not before (P1) or after (P20). This early effect of LPS on adult seizures was blocked by concurrent intracerebroventricular administration of a tumor necrosis factor alpha (TNFalpha) antibody and mimicked by intracerebroventricular injection of rat recombinant TNFalpha. Postnatal LPS injection did not result in permanent changes in microglial (Iba1) activity or hippocampal cytokine [IL-1beta (interleukin-1beta) and TNFalpha] levels, but caused a slight increase in astrocyte (GFAP) numbers. These novel results indicate that a single LPS injection during a critical postnatal period causes a long-lasting increase in seizure susceptibility that is strongly dependent on TNFalpha.

Dietary Patterns and Components in Nonalcoholic Fatty Liver Disease (NAFLD): What Key Messages Can Health Care Providers Offer?

Nonalcoholic fatty liver disease (NAFLD) is a rising epidemic worldwide and will be the leading cause of cirrhosis, hepatocellular carcinoma, and liver transplant within the next decade. NAFLD is considered as the hepatic manifestation of metabolic syndrome. Behaviors, such as a sedentary lifestyle and consuming a Western diet, have led to substantial challenges in managing NAFLD patients. With no curative pharmaceutical therapies, lifestyle modifications, including dietary changes and exercise, that ultimately lead to weight loss remain the only effective therapy for NAFLD. Multiple diets, including low-carbohydrate, low-fat, Dietary Approaches to Stop Hypertension (DASH), and Mediterranean (MD) diets, have been evaluated. NAFLD patients have shown better outcomes with a modified diet, such as the MD diet, where patients are encouraged to increase the consumption of fruits and vegetables, whole grains, and olive oil. It is increasingly clear that a personalized approach to managing NAFLD patients, based on their preferences and needs, should be implemented. In our review, we cover NAFLD management, with a specific focus on dietary patterns and their components. We emphasize the successful approaches highlighted in recent studies to provide recommendations that health care providers could apply in managing their NAFLD patients.

The nonadrenergic noncholinergic-mediated relaxation of corpus cavernosum was impaired in chronic lithium-treated rats: improvement with l-arginine.

One-third of lithium-treated men complain from sexual dysfunction, although the exact mechanisms of which are not yet known. In this study we investigated the effect of chronic lithium (LiCl, 600 mg/l for 30 days) administration on the neurogenic relaxation of isolated rat corpus cavernosum. The corporal strips were precontracted with phenylephrine and electrical field stimulation (EFS) was applied to obtain relaxation. Relaxation to EFS was significantly (P<0.001) impaired in LiCl-treated rats. The nitric oxide (NO) synthase inhibitor Nomega-nitro-l-arginine methyl ester (l-NAME; 100 microM) inhibited the relaxation to EFS in both LiCl-treated and control rats. The NO precursor l-arginine, at per se noneffective concentration (0.1 mM), significantly (P<0.001) enhanced the EFS-induced relaxation of LiCl-treated corporal strips. The relaxation responses to the NO donor sodium nitroprusside were similar between two groups. These data demonstrate that chronic lithium treatment could impair the NO-mediated neurogenic relaxation of rat corpus cavernosum which could be prevented by l-arginine.

Seizure susceptibility alteration following reversible cholestasis in mice: Modulation by opioids and nitric oxide.

There is an increasing body of evidence that the central nervous system is affected by cholestatic liver disorders. Cholestasis has been shown to result in a decreased seizure propensity which is believed to be mediated by an increased opioidergic tone and nitric oxide (NO) signaling pathway. In this study, we used a reversible chemically-induced cholestasis model in mice to investigate the changes in seizure susceptibility. The cholestasis was induced by intragastric administration of alpha-naphthylisothiocyanate (ANIT) (100 mg/kg) or vehicle (corn oil). The threshold to generalized clonic seizures induced by timed intravenous infusion of pentylenetetrazole (PTZ) was used as an index of seizure propensity. The role of opioid receptors and NO pathway in the changes of seizure threshold, and the responsiveness to the anticonvulsant effect of opioid agonist, morphine, during and after the resolution of cholestasis was studied in this reversible paradigm of cholestatic disease. A significant increase in cholestasis-related biochemical markers as well as in clonic seizure threshold was observed; it was maximal at day 3 after cholestasis induction and slowly decreased to normal thereafter. Seizure threshold rise was inhibited by chronic administration of the opioid antagonist naltrexone or acute administration of N-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO production. Co-administration of subeffective doses of L-NAME and naltrexone showed an additive effect. Injection of an anticonvulsant dose of morphine on day 7 after cholestasis induction did not increase seizure threshold, suggestive of a downregulation of receptors even after cholestasis resolution. These data shows that ANIT-induced cholestasis leads to a reversible increased resistance to PTZ-induced seizures through an opioid/NO-mediated pathway, and is probably accompanied by downregulation of opioid receptors.

Role of nitric oxide in the anticonvulsive effect of progesterone.

Described here is an investigation of the potential interaction of the nitric oxide signaling pathway with the anticonvulsant effects of progesterone. In ovariectomized Swiss mice, the threshold for seizures induced by intravenous infusion of pentylenetetrazole was determined after treatment with progesterone (25, 50, or 75 mg/kg, given subcutaneously 6h before seizure testing) or vehicle. Progesterone induced significant anticonvulsive activity at moderate (50 mg/kg) and high (75 mg/kg) doses. This effect of progesterone was abolished by the NO precursor compound L-arginine (200 mg/kg). Moreover, when subeffective doses of progesterone (25 mg/kg) and the NO synthase inhibitor N(omega)-nitro-L-arginine methyl ester (10 mg/kg) were injected, a strong anticonvulsant effect was observed. These findings suggest a potential role for NO signaling as an anticonvulsant target in females.

Nitric oxide involvement in estrous cycle-dependent changes of the behavioral responses of female rats in the elevated plus-maze test.

Nitric oxide (NO)/cGMP pathway is known as a mediator in anxiety modulation. In this study, we assessed the involvement of NO pathway in the estrous cycle-related changes of anxiety level in rat. By using elevated plus-maze test, we studied the changes of serum nitrate and nitrite (NO(x)) levels in comparison to the estrous cycle-dependent changes of anxiety state. Then, we tested the effects of nitric oxide synthase (NOS) inhibitor, L-NAME (10, 60mg/kg, i.p.), and the NO precursor, l-arginine (100mg/kg, i.p.) on anxiety modulatory properties of exogenous ovarian hormones in ovariectomized (OVX) rats. Compared with other cycle phases and with OVX rats, cycling rats spent more time in open arms and had lower levels of serum NO(x) levels during metestrous while they spent less time in open arms and had lower levels of serum NO(x) levels during proestrous. In OVX rats, L-NAME (60mg/kg, i.p.) exerted anxiolytic effect while l-arginine showed no effect. In comparison with corn oil-treated controls, estradiol benzoate (10microg/kg, subcutaneously (s.c.)) significantly increased the serum NO(x) level and exerted anxiogenic effect, which was dose-dependently inhibited by L-NAME but was not changed by l-arginine. In contrast, progesterone (25mg/kg, s.c.) significantly decreased the serum NO(x) level and exerted anxiolytic effect, which was abolished by l-arginine but was not affected by L-NAME. These findings suggest that NO system might be involved in the estrous cycle-related changes of anxiety level, probably by mediating the effect of ovarian sex hormones.

Melatonin enhances the anticonvulsant and proconvulsant effects of morphine in mice: role for nitric oxide signaling pathway.

Melatonin has different interactions with opioids including enhancing their analgesic effect and reversal of opioid tolerance and dependence. Opioids are known to exert dose-dependent anti- and proconvulsant effects in different experimental seizure paradigms. This study investigated the effect of melatonin on biphasic modulation of seizure susceptibility by morphine, in mouse model of pentylenetetrazole (PTZ)-induced clonic seizures. We further investigated the involvement of the nitric oxidergic pathway in this interaction, using a nitric oxide synthase inhibitor, NG-nitro-L-arginine-methyl-ester (L-NAME). Melatonin exerted anticonvulsant effect with doses as high as 40-80 mg/kg, but with a dose far bellow that amount (10 mg/kg), it potentiated both the anticonvulsant and proconvulsant effects of morphine on the PTZ-induced clonic seizures. Possible pharmacokinetic interaction of melatonin and morphine cannot be ruled out in the enhancement of two opposing effects of morphine on seizure threshold. L-NAME (1 mg/kg) reversed the anticonvulsant property of the combination of melatonin (10 mg/kg) plus morphine (0.5 mg/kg). Moreover, L-NAME (5 mg/kg) blocked the enhancing effect of melatonin (10 mg/kg) on proconvulsant activity of morphine (60 mg/kg). Our results indicate that co-administration of melatonin enhances both anti- and proconvulsant effects of morphine via a mechanism that may involve the nitric oxidergic pathway.

Effect of low-dose aspirin therapy on implantation rate in women undergoing in-vitro fertilization cycles.

OBJECTIVE: To determine the effect of low-dose aspirin on ovarian response, implantation and pregnancy rates in patients undergoing in-vitro fertilization (IVF) cycles. METHODS: We performed a randomized analysis of 145 infertile women with a mean+/-SD age of 29.6 +/- 4.47 years who underwent cycles of IVF. Patients received 100 mg of aspirin (n=72) or placebo (n=73) daily. This study was conducted in Royan Institute, Tehran, Iran from April 2002 to January 2004. Aspirin was started on the 21st of their preceding menstrual cycle and it was continued until menstruation or a negative pregnancy test. Pregnant women received the medication until 12 weeks of pregnancy. The main outcome measures were number of follicles >or=15 mm, number of oocytes retrieved, serum E2 levels, cancellation rate, Ovarian Hyperstimulation Syndrome (OHSS) occurrence, number of embryos transferred, and implantation and pregnancy rates. RESULTS: There were statistically significant differences between the treatment group and the control group in the number of follicles (7.4 +/- 4.1 versus 9.0 +/- 4.8) and OHSS occurrence (5.6% versus 23.3%) but not in the other measures. CONCLUSION: The addition of aspirin low dose (100 mg/daily) to the standard long protocol for oocyte retrieval did not improve implantation and pregnancy rates in unselected patients undergoing IVF cycles.