Preliminary pharmacokinetics and pharmacodynamics of an ultra-short-acting opioid: remifentanil (GI87084B)

Remifentanil is a newly synthesized 4-anilido-piperidine with an ester side chain susceptible to esterase metabolism. We evaluated the safety, analgesic efficacy, and pharmacokinetics of remifentanil in 48 male volunteers. Volunteers were randomized to receive increasing doses of remifentanil, alfentanil, or placebo. Analgesic efficacy was evaluated by increasing tolerance to a spring-loaded rod measured at the tibia and sternum at multiple time points. Respiratory depression was measured by changes in arterial blood gas tensions and peripheral hemoglobin oxygen saturation. Hemodynamics were continuously monitored by means of an intra-arterial catheter. Both remifentanil and alfentanil produced a dose-dependent increase in analgesia and respiratory depression. Remifentanil was 20 to 30 times more potent (milligram to milligram) than alfentanil when assessed by either analgesic efficacy or respiratory measures. The pharmacokinetics of remifentanil were best described by a biexponential decay curve. Remifentanil had a small volume of distribution of 0.39 (SD, +/- 0.25) L/kg (alfentanil, 0.52 +/- 2 L/kg), with a rapid distribution phase of 0.94 (SD, +/- 0.57) min and an extremely short elimination half-life of 9.5 (SD, +/- 4) min compared with an elimination half-life of alfentanil of 58 (SD, +/- 7.6) min. The t1/2 ke0 (half-time for equilibration between plasma and the effect compartment) of remifentanil for analgesia was calculated as 1.3 min. Thus, remifentanil appears to have a pharmacologic profile similar to other potent mu agonists, but with exceptionally short-lasting pharmacokinetics, which is likely to make it a very useful opioid for clinical practice.

Evolution of brain infarction after transient focal cerebral ischemia in mice

The evolution of brain infarction after transient focal cerebral ischemia was studied in mice using multiparametric imaging techniques. One-hour focal cerebral ischemia was induced by occluding the middle cerebral artery using the intraluminal filament technique. Cerebral protein synthesis (CPS) and the regional tissue content of adenosine triphosphate (ATP) were measured after recirculation times from 0 hours to 3 days. The observed changes were correlated with the expression of the mRNAs of hsp-70, c-fos, and junB, as well as the distribution of DNA double-strand breaks, visualized by TUNEL. At the end of 1 hour of ischemia, protein synthesis was suppressed in a larger tissue volume than ATP in accordance with the biochemical differentiation between core and penumbra. Hsp70 mRNA was selectively expressed in the cortical penumbra, whereas c-fos and junB mRNAs were increased both in the lateral part of the penumbra and in the ipsilateral cingulate cortex with normal metabolism. During reperfusion after withdrawal of the intraluminal filament, suppression of CPS persisted except in the most peripheral parts of the middle cerebral artery territory, in which it recovered between 6 hours and 3 days. ATP, in contrast, returned to normal levels within 1 hour but secondarily deteriorated from 3 hours on until, between 1 and 3 days, the ATP-depleted area merged with that of suppressed protein synthesis leading to delayed brain infarction. Hsp70 mRNA, but not c-fos and junB, was strongly expressed during reperfusion, peaking at 3 hours after reperfusion. TUNEL-positive cells were detected from 3 hours on, mainly in areas with secondary ATP depletion. These results stress the importance of an early recovery of CPS for the prevention of ischemic injury and suggest that TUNEL is an unspecific response of delayed brain infarction.

Alcohol-associated stimuli activate the ventral striatum in abstinent alcoholics

Alcohol-associated cues may act as conditioned stimuli that activate the brain reward system and motivate alcohol intake in alcoholics. Alcohol-associated visual stimuli were presented during functional magnetic resonance imaging. An activation of the ventral putamen was observed in alcoholics but not in control subjects. Patients with a strong activation of the ventral putamen relapsed during the next three months. This observation supports the hypothesis that alcohol use affects areas involved in brain reward circuits and that their stimulus-induced activation may be associated with an increased risk for relapse.

Development of alcohol-associated cues and cue-induced brain activation in alcoholics

The objective of this study was to develop new standardized alcohol-associated cues and assess their effects on brain activation with functional magnetic resonance imaging (fMRI). Pictures of alcoholic and neutral beverages and affectively neutral pictures were presented to 44 abstinent alcoholics and 37 age-matched healthy control subjects. We assessed the skin conductance response, and the elicited arousal and valence. Alcoholics and control subjects did not differ in arousal, valence or skin conductance response evoked by alcohol-associated and affectively neutral stimuli, while nonalcoholic beverages were rated as more unpleasant and arousing by alcoholics compared with control subjects. In the fMRI pilot study, alcohol and abstract pictures were presented to six abstinent alcoholics and induced a significant activation of brain areas associated with visual emotional processes such as the fusiform gyrus, parts of the brain reward system (basal ganglia and orbitofrontal gyrus) and further brain regions in the frontal and parietal cortices associated with the attention network. These observations suggest that standardized pictures of alcoholic beverages can be used to assess brain circuits involved in the processing and evaluation of alcohol cues.

Dynamics of regional brain metabolism and gene expression after middle cerebral artery occlusion in mice

The evolution of brain infarcts during permanent occlusion of the middle cerebral artery (MCA) was studied in mice using multiparametric imaging techniques. Regional protein synthesis and the regional tissue content of ATP were measured on adjacent cryostat sections at increasing intervals after vascular occlusion ranging from 1 hour to 3 days. The observed changes were correlated with the expression of the mRNA of hsp70, c-fos, c-jun, and junB, as well as the distribution of DNA double-strand breaks visualized by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL). One hour after MCA occlusion, the tissue volume with suppressed protein synthesis was distinctly larger than that in which ATP was depleted. With ongoing ischemia time, the ATP-depleted area gradually expanded and, within 1 day, merged with the region of suppressed protein synthesis. Expression of hsp70 mRNA occurred mainly in the penumbra (defined as the region of suppressed protein synthesis but preserved ATP), peaking at 3 hours after vascular occlusion. Expression of the immediate-early genes c-jun, c-fos, and junB increased both in the penumbra and the periinfarct normal tissue already at 1 hour after vascular occlusion, with slightly different regional and temporal patterns for each of these genes. DNA fragmentations were clearly confined to neurons; they appeared after 1 day in the infarct core (defined as the region of suppressed ATP) and never were detected in the penumbra. The late appearance of TUNEL after infarcts had reached their final size and the absence in the penumbra points against a major pathogenetic role of apoptosis. Permanent MCA occlusion in mice thus produces a gradually expanding infarct, the final size of which is heralded by the early inhibition of protein synthesis.

Diurnal variations in the human host response to endotoxin

To investigate diurnal variations in the host response to endotoxin, Salmonella abortus equi endotoxin (0.8 ng/kg) was given intravenously to healthy men in a placebo-controlled design at 0900 or 1900 h. The time course of rectal temperature and the plasma levels of tumor necrosis factor- alpha (TNF-alpha), interleukin-6 (IL-6), adrenocorticotropic hormone (ACTH), and cortisol were monitored for 11 h following the injections. The time of day did not affect the endotoxin-induced increase in plasma TNF-alpha or IL-6. However, subjects who received endotoxin in the evening, when endogenous glucocorticoid levels were low, showed about twice the increases in rectal temperature and plasma ACTH and cortisol levels as those who received endotoxin in the morning, when endogenous glucocorticoid levels were high. These results demonstrate diurnal variations in the human susceptibility to endotoxin that may be due to a suppression of the biologic effects of TNF-alpha and IL-6 by endogenous glucocorticoids.

Development of a Multicompartment Permeability-Limited Lung PBPK Model and Its Application in Predicting Pulmonary Pharmacokinetics of Antituberculosis Drugs

Achieving sufficient concentrations of antituberculosis (TB) drugs in pulmonary tissue at the optimum time is still a challenge in developing therapeutic regimens for TB. A physiologically based pharmacokinetic model incorporating a multicompartment permeability-limited lung model was developed and used to simulate plasma and pulmonary concentrations of seven drugs. Passive permeability of drugs within the lung was predicted using an in vitro-in vivo extrapolation approach. Simulated epithelial lining fluid (ELF):plasma concentration ratios showed reasonable agreement with observed clinical data for rifampicin, isoniazid, ethambutol, and erythromycin. For clarithromycin, itraconazole and pyrazinamide the observed ELF:plasma ratios were significantly underpredicted. Sensitivity analyses showed that changing ELF pH or introducing efflux transporter activity between lung tissue and ELF can alter the ELF:plasma concentration ratios. The described model has shown utility in predicting the lung pharmacokinetics of anti-TB drugs and provides a framework for predicting pulmonary concentrations of novel anti-TB drugs.

Novel mutant Semliki Forest virus vectors: gene expression and localization studies in neuronal cells

Semliki Forest virus vectors (SFV) are suitable for high-level transgene expression in neuronal tissue, both in vitro and in vivo. Cortical and hippocampal primary neurons in culture are efficiently infected resulting in 75-95% of GFP-positive cells, and injection of SFV vectors into hippocampal slice cultures revealed a highly neuron-specific expression pattern with more than 90% of the infected cells being neurons. Here, we present novel SFV vector mutants and describe their infection patterns obtained in cultures of baby hamster kidney (BHK) cells, dissociated hippocampal neurons, and organotypic hippocampal slices. A less cytotoxic vector SFV(PD), carrying two point mutations in the nsP2 gene, showed much higher GFP expression levels in primary hippocampal neurons compared to the wild-type SFV vector. A triple mutant vector SFV(PDE153) demonstrated a temperature-sensitive phenotype in both BHK cells and primary neurons. In hippocampal slices cultured at 36 degrees C, SFV(PDE153) showed a remarkably higher (ca 250-fold) preference for expression in interneurons rather than in pyramidal cells as compared to wild-type SFV. The quadruple mutant SFV(PDTE) led to substantially increased and prolonged GFP expression in primary neurons. Relative to SFV(PDE153), a more pronounced temperature-sensitive phenotype was found resulting in no virus production and no GFP expression at the non-permissive temperature (36-37 degrees C) in BHK cells, in dissociated neurons, and in organotypic hippocampal slices. The described novel SFV vectors will be useful for several specific applications in neurobiology.

A model for the turnover of dihydrotestosterone in the presence of the irreversible 5 alpha-reductase inhibitors GI198745 and finasteride

OBJECTIVE

To develop a pharmacokinetic-pharmacodynamic model that characterizes the conversion of testosterone to dihydrotestosterone (DHT) by 5 alpha-reductase types 1 and 2 and the irreversible inhibition of 5 alpha-reductase by finasteride, a 5 alpha-reductase type 2 inhibitor and by GI198745 (dutasteride), a potent and specific dual 5 alpha-reductase inhibitor.

METHODS

Healthy men (n = 48) received doses of 0.1 to 40 mg GI198745 (n = 4 subjects per dose), 5 mg finasteride (n = 8), or placebo (n = 8) in a parallel-group study. Plasma concentrations of GI198745, finasteride, and DHT were measured frequently up to 8 weeks after dosing. Models were fitted with mixed-effects modeling with the NONMEM program.

RESULTS

The pharmacodynamics were well described with a model that accounted for the rates of DHT formation and elimination, 5 alpha-reductase turnover, relative capacity of the 2 5 alpha-reductase isozymes, and the rates of irreversible inhibition of one (finasteride) or both (GI198745) types of 5 alpha-reductase. The model indicated that type 2 5 alpha-reductase contributed approximately 80% of plasma DHT. GI198745 was about 3-fold more potent than finasteride on 5 alpha-reductase type 2. Nearly full blockade of both isozymes was achieved at doses of 10 mg or more GI198745, although the potency of this agent on 5 alpha-reductase type 1 was less than on type 2.

CONCLUSIONS

A physiologically based model for the turnover and irreversible inhibition of 5 alpha-reductase and for formation and elimination of DHT described the data well. This model helps explain differences in the rates of onset and offset of effect and offers a way to determine the relative potency of the irreversible 5 alpha-reductase inhibitors.

Semliki Forest virus vectors: efficient vehicles for in vitro and in vivo gene delivery

Rapidly generated high-titer Semliki Forest virus (SFV) vectors can infect numerous mammalian cell lines and primary cell cultures, and result in high levels of transgene expression. SFV-based expression of transmembrane receptors has been characterized by specific ligand-binding activity and functional responses. Adaptation of the SFV technology for mammalian suspension cultures has allowed the production of hundreds of milligrams of recombinant receptor for purification and structural studies. The same SFV stock solutions used for the infection of mammalian cells in culture have also been successfully applied for efficient transgene expression in organotypic hippocampal slices, as well as in vivo in rodent brain.

Studies on wound healing: effects of calcium D-pantothenate on the migration, proliferation and protein synthesis of human dermal fibroblasts in culture

The effect of calcium D-pantothenate on the migration, proliferation and protein synthesis of human dermal fibroblasts from three different donors was investigated. The migration of cells into a wounded area was dose-dependently stimulated by Ca D-pantothenate. The number of cells that migrated across the edge of the wound increased from 32 +/- 7 cells/mm without Ca D-pantothenate to 76 +/- 2 cells/mm with 100 mg/ml Ca D-pantothenate. Moreover, the mean migration distance per cell increased from 0.23 +/- 0.05 mm to 0.33 +/- 0.02 mm. The mean migration speed was calculated to be 10.5 mm/hour without and 15 mm/hour with Ca D-pantothenate. Cell proliferation was also dose-dependently stimulated. The final cell densities were 1.2 to 1.6-fold higher in cultures containing 100 mg/ml Ca D-pantothenate. The protein synthesis was modulated, since two unidentified proteins were more strongly expressed in pantothenate supplemented cultures. In conclusion, Ca D-pantothenate accelerates the wound healing process by increasing the number of migrating cells, their distance and hence their speed. In addition, cell division is increased and the protein synthesis changed. These results suggest that higher quantities of pantothenate are locally required to enhance wound healing.

The effect of caffeine on intraocular pressure in glaucoma patients

The authors investigated the effect of drinking regular coffee on intraocular pressure (IOP) using a single-masked randomized crossover study comparing coffee and herbal tea in 13 glaucoma patients. Intraocular pressure and blood pressure were monitored before ingestion of coffee or tea and at 30, 60, and 90 minutes after ingestion. The mean (+/- standard error of measurement) change in IOP 30, 60, and 90 minutes after ingestion for the coffee drinkers was 0.96 +/- 0.4, 1.38 +/- 0.53, and 1.04 +/- 0.37 mmHg, respectively. The mean change in IOP for the tea drinkers 30, 60, and 90 minutes after ingestion was 0.85 +/- 0.41, 0.23 +/- 0.36, and -0.42 +/- 0.44 mmHg, respectively. There was a statistically significant difference in the change in IOP at 90 minutes when comparing coffee to tea (P = 0.003) and no significant difference for 30 and 60 minutes. Although there was a statistically significant difference in IOP at 90 minutes between coffee and tea drinkers, the change was not clinically significant.

Synaptic transmission is impaired prior to plaque formation in amyloid precursor protein-overexpressing mice without altering behaviorally-correlated sharp wave-ripple complexes

One of the hallmarks of Alzheimer's disease is the accumulation of amyloid plaques in brains of affected patients. Several recent studies provided evidence that soluble oligomer forms of amyloid-beta (Abeta) rather than plaques determine cognitive decline. In vitro studies using artificial Abeta oligomer preparations suggest that such pathophysiology is caused by a specific impairment of synaptic function. We examined whether synaptic deficits occur before deposition of insoluble fibrillar Abeta by analyzing brain slices taken from young Tg2576 mice overexpressing mutant amyloid precursor protein. Excitatory synaptic transmission in the hippocampal CA1 region was strongly impaired before plaque development, suggesting a dissociation of an early synaptic impairment, probably caused by soluble oligomeric amyloid-beta, from subsequent plaque formation. At higher age neurotransmission was also decreased in wild type mice, paralleling a cognitive decline of normal aged animals. Memory formation in rats is accompanied by distinct hippocampal network oscillations. It has recently been shown that hippocampal gamma oscillations, a network correlate of exploratory behavior, are impaired in amyloid precursor protein (APP)-overexpressing mice. We determined whether sharp wave-ripple complexes, which contribute to memory consolidation during slow wave-sleep, are modified in Tg2576 mice. Interestingly, neither sharp waves nor superimposed ripples were changed at pre-plaque or plaque stages. During aging, however, there was a strong reduction of sharp wave frequency and ripple energy in wild type and APP-overexpressing animals. This indicates that the reported changes in network oscillations following APP-overexpression are specific for gamma oscillations, whereas aging has a more general effect on network properties. Taken together our data suggest that non-fibrillar forms of Abeta--possibly Abeta oligomers--specifically interfere with synaptic function in Tg2576, but do not globally alter memory-related network properties. We propose that mechanisms leading to Abeta-related cognitive decline are different from those related to aging.

A comparison of region-of-interest measures for extracting whole brain data using survival analysis in alcoholism as an example

BACKGROUND

Aggregation of functional magnetic resonance imaging (fMRI) data in regions-of-interest (ROIs) is required for complex statistical analyses not implemented in standard fMRI software. Different data-aggregation measures assess various aspects of neural activation, including spatial extent and intensity.

NEW METHOD

In this study, conducted within the framework of the PREDICT study, we compared different aggregation measures for voxel-wise fMRI activations to be used as prognostic factors for relapse in 49 abstinent alcohol-dependent individuals in an outpatient setting using a cue-reactivity task. We compared the importance of the data-aggregation measures as prognostic factors for treatment outcomes by calculating the proportion of explained variation.

RESULTS AND COMPARISON WITH EXISTING METHOD(S)

Relapse risk was associated with cue-induced brain activation during abstinence in the ventral striatum (VS) and in the orbitofrontal cortex (OFC). While various ROI measures proved appropriate for using fMRI cue-reactivity to predict relapse, on the descriptive level the most "important" prognostic factor was a measure defined as the sum of t-values exceeding an individually defined threshold. Data collected in the VS was superior to that from other regions.

CONCLUSIONS

In conclusion, it seems that fMRI cue-reactivity, especially in the VS, can be used as prognostic factor for relapse in abstinent alcohol-dependent patients. Our findings suggest that data-aggregation measures that take both spatial extent and intensity of cue-induced brain activation into account make better biomarkers for predicting relapse than measures that consider an activation's spatial extent or intensity alone.

Age-dependent suppression of nocturnal growth hormone levels during sleep deprivation

Although the major daily peak in plasma growth hormone (GH) level normally occurs during the early part of nocturnal sleep, it is known that in about one quarter of young healthy men, peaks in circulating human GH occur before sleep onset. Possible factors associated with these nocturnal peaks were investigated in the absence of sleep, including subjectively defined sleepiness, electroencephalographically defined drowsiness and short lapses into sleep, measures of cortisol and temperature. Healthy men between the ages of 20 and 34 years were studied in a between-subjects design, 16 assigned to a sleep deprivation group, and 16 age matched and assigned to a group permitted to sleep. The average GH peak level in the sleeping subjects was 19.9 micrograms/l (+/- 8.4 SD). In the sleep-deprivation group there was a wide range of nocturnal GH patterns, from no detectable rise to normal nocturnal levels (average peak of 10.5 +/- 10.0 micrograms/l). Within the narrow age range sampled, age, body mass index, temperature and cortisol failed to predict nocturnal GH peak in the sleeping group, but regression analysis found age to be a significant negative predictor of nocturnal GH peak level in sleep-deprived subjects. All sleep-deprived subjects who had peak GH levels over 7 micrograms/l were 24 years of age or less. Subjective sleepiness and electroencephalographically defined drowsiness failed to predict either the peak level of GH during sleep deprivation or the cumulative amount measured across the night. These results suggest that the well-known suppressive effect of sleep deprivation on GH secretion is an age-dependent phenomenon which evolves during early adulthood.

The pharmacokinetic modelling of GI198745 (dutasteride), a compound with parallel linear and nonlinear elimination

AIMS

To characterize the pharmacokinetics of the dual 5alpha-reductase inhibitor GI198745 (dutasteride) to allow for more accurate predictions of GI198745 concentrations after different dosing schedules.

METHODS

In this randomized, single-blind, parallel group study, 32 healthy male volunteers received single oral doses of GI198745 ranging from 0.01 to 40 mg. Data were analysed by nonlinear mixed effects modelling using NONMEM where both linear and nonlinear pharmacokinetic models were examined.

RESULTS

The time course of GI198745 serum concentrations indicated concentration dependent elimination, with the apparent half-life increasing with dose. Data were best described by a two-compartment model with first order absorption and parallel linear and nonlinear elimination pathways. Drug absorption was rapid, and was followed by a short distribution phase. A high volume of distribution (511 l) and a low linear clearance (0.58 l h(-1)) combined to give a half-life of up to 5 (1-7) weeks at high concentrations. As concentrations declined towards Km (0.96 ng ml(-1)), the proportion eliminated by the relatively rapid saturable elimination pathway, with a maximum clearance of 6.2 l h(-1), increased and the half-life reduced to about 3 days. The estimated inter individual variability for the linear clearance was high (CV = 70%).

CONCLUSIONS

G1198745 pharmacokinetics are well described by a pharmacokinetic model with parallel linear and nonlinear elimination. Simulations using this model show that at daily doses of 0.1 mg the steady state drug concentrations, and the rate at which these are achieved, are mainly influenced by the nonlinear pathway, while at daily doses above 1 mg they are almost entirely influenced by the linear pathway.

Hemodynamics and metabolism in stroke-prone spontaneously hypertensive rats before manifestation of brain infarcts

Genomic screening of hybrids from stroke-prone (SHR-SP) and stroke-resistant spontaneously hypertensive rats (SHR) identified a STR1 locus on the rat chromosome 1, which correlates with the susceptibility to cerebral stroke but not with hypertension. The authors examined whether this genetic abnormality is associated with hemodynamic or metabolic alterations in the brain that can be detected before the manifestation of brain infarction. Starting at 6 weeks of age, SHR-SP were fed with a salt-rich diet to accelerate arterial hypertension. At the age of 12 weeks, animals developed functional symptoms and were age-matched with symptom-negative SHR-SP to differentiate between presymptomatic and postsymptomatic changes. Brains were investigated by multiparametric imaging comprising quantitative double-tracer autoradiography of CBF and cerebral protein synthesis (CPS); bioluminescence imaging of regional ATP, glucose, and lactate content; and umbelliferone fluoroscopic imaging of tissue pH. None of the animals exhibited focal hemodynamic or biochemical abnormalities. In symptom-negative SHR-SP, global CBF was 1.1+/-0.3 mL x g(-1) x min(-1), cortical CPS was 10.1+/-3.1 nmol x g(-1) x min(-1), and cortical ATP, glucose, lactate, and pH levels were in the normal range. In SHR-SP with functional symptoms, ATP, glucose, and lactate levels also were normal, but tissue pH exhibited periventricular alkalosis, CBF was significantly reduced to 0.7+/-0.2 mL x g(-1) x min(-1) (P < 0.001), and cortical CPS was significantly reduced to 6.7+/-2.1 nmol x g(-1) x min(-1) (P < 0.001). The decline in brain perfusion of SHR-SP correlated significantly with both the severity of functional deficits and the decline of protein synthesis. Our observations demonstrate that SHR-SP had already developed functional symptoms before the manifestation of overt brain infarcts and that the symptoms are initiated by a decline in global CBF and cortical CPS. Genetic abnormalities in SHR-SP are associated with a diffuse vascular process that results in global decompensation of blood flow well before the onset of focal brain infarction.

Surgery for nonpalpable breast lesions

Nonpalpable lesions detected on mammograms were localized in 475 women between 1976 and 1988 by means of the spot method. A malignant neoplasm was noted in 149 patients (31%), including 69 (33%) of 206 with clusters of microcalcifications, 16 (41%) of 39 with calcifications associated with densities and 64 (28%) of 230 with nonpalpable masses. Infiltrating lesions were present in 89 (60%) of 149 patients. Among women with infiltrating lesions who had axillary dissection, 14 (21%) of 67 had positive nodes. In younger women, microcalcifications were more likely to represent neoplasms, masses frequently represented invasive tumors. Among patients with invasive malignant neoplasms who had calcifications, 39% had positive axillary lymph nodes. Spot localization, rather than monitoring, seems appropriate in young women with microcalcifications suggestive of malignant neoplasms and older patients with nonpalpable masses to achieve earlier and more effective treatment of biologically significant occult neoplasms.

Increased apoptosis in bovine blastocysts exposed to high levels of IGF1 is not associated with downregulation of the IGF1 receptor

The hypothesis that high concentrations of IGF1 can impair embryo development was investigated in a bovine in vitro model to reflect conditions in polycystic ovary syndrome (PCOS) patients. Embryos were either cultured in the absence or presence of a physiological (100 ng/ml) or supraphysiological (1000 ng/ml) IGF1 concentration. Cell allocation, apoptosis, transcript and protein expression of selected genes involved in apoptosis, glucose metabolism and the IGF system were analysed. Supraphysiological IGF1 concentration did not improve blastocyst formation over controls, but induced higher levels of apoptosis, decreased TP53 protein expression in the trophectoderm and increased the number of cells in the inner cell mass (ICM). The increase in ICM cells corresponded with an increase in IGF1 receptor (IGF1R) protein in the ICM. A small, but significant, percentage of blastocysts displayed a hypertrophic ICM, not observed in controls and virtually absent in embryos treated with physiological concentrations of IGF1. Physiological IGF1 concentrations increased total IGF1R protein expression and upregulated IGFBP3 transcripts leading to an increase in blastocyst formation with no effects on cell number or apoptosis. In conclusion, the results support the hypothesis of detrimental effects of supraphysiological IGF1 concentrations on early pregnancy. However, our results do not support the premise that increased apoptosis associated with high levels of IGF1 is mediated via downregulation of the IGF1R as previously found in preimplantation mouse embryos. This in vitro system with the bovine preimplantation embryo reflects critical features of fertility in PCOS patients and could thus serve as a useful model for in-depth mechanistic studies.

Clofazimine for Treatment of Cryptosporidiosis in Human Immunodeficiency Virus Infected Adults: An Experimental Medicine, Randomized, Double-blind, Placebo-controlled Phase 2a Trial

BACKGROUND

We evaluated the efficacy, pharmacokinetics (PK), and safety of clofazimine (CFZ) in patients living with human immunodeficiency virus (HIV) with cryptosporidiosis.

METHODS

We performed a randomized, double-blind, placebo-controlled study. Primary outcomes in part A were reduction in Cryptosporidium shedding, safety, and PK. Primary analysis was according to protocol (ATP). Part B of the study compared CFZ PK in matched individuals living with HIV without cryptosporidiosis.

RESULTS

Twenty part A and 10 part B participants completed the study ATP. Almost all part A participants had high viral loads and low CD4 counts, consistent with failure of antiretroviral (ARV) therapy. At study entry, the part A CFZ group had higher Cryptosporidium shedding, total stool weight, and more diarrheal episodes compared with the placebo group. Over the inpatient period, compared with those who received placebo, the CFZ group Cryptosporidium shedding increased by 2.17 log2 Cryptosporidium per gram stool (95% upper confidence limit, 3.82), total stool weight decreased by 45.3 g (P = .37), and number of diarrheal episodes increased by 2.32 (P = .87). The most frequent solicited adverse effects were diarrhea, abdominal pain, and malaise. One placebo and 3 CFZ participants died during the study. Plasma levels of CFZ in participants with cryptosporidiosis were 2-fold lower than in part B controls.

CONCLUSIONS

Our findings do not support the efficacy of CFZ for the treatment of cryptosporidiosis in a severely immunocompromised HIV population. However, this trial demonstrates a pathway to assess the therapeutic potential of drugs for cryptosporidiosis treatment. Screening persons living with HIV for diarrhea, and especially Cryptosporidium infection, may identify those failing ARV therapy.

CLINICAL TRIALS REGISTRATION

NCT03341767.

Quetiapine in relapse prevention in alcoholics suffering from craving and affective symptoms: a case series

PURPOSE

Quetiapine is a novel antipsychotic, which is efficacious in the treatment of positive and negative symptoms in schizophrenia. Research has shown that atypical antipsychotic also reduce the craving and consumption for stimulants and alcohol. Due to Quetiapine's particulars and the promising receptor profile concerning addiction medicine, we set out to examine the tolerability and efficacy concerning relapse prevention of withdrawn alcoholics suffering from craving and affective symptoms.

SUBJECTS AND METHODS

Our case observations attempted to evaluate nine alcoholics after withdrawal suffering from persisting craving, sleep disorder, excitement, depressive symptoms or anxiety symptoms. The patients were treated with quetiapine as relapse prevention and we followed them up in our outpatient clinic.

RESULTS

Eight out of nine patients were abstinent under quetiapine over a period of 2-7 months. One of these patients relapsed after he stopped taking the preparation at his own initiative after 10 weeks. The ninth patient stopped taking the preparation immediately because of swollen nasal mucosae. All target symptoms disappeared in the patients after an average of (mean+/-S.D.) 24.5+/-18.1 days. The overall tolerability was considered to be very good; however, initial sleepiness appeared in four patients.

CONCLUSION

Although uncontrolled case observations can only be interpreted with caution quetiapine seems to deserve further investigation and may hold the potential for preventing alcohol relapse in alcoholics suffering from additional above-mentioned symptoms.

Effects on platelet function of an EP3 receptor antagonist used alone and in combination with a P2Y12 antagonist both in-vitro and ex-vivo in human volunteers

EP3 receptor antagonists may provide a new approach to the treatment of atherothrombotic disease by blocking the ability of prostaglandin E2 (PGE2) to promote platelet function acting via EP3 receptors. DG-041 is an EP3 antagonist in the early stage of clinical development. Here, we quantitated effects on platelet function of DG-041 in-vitro and ex-vivo after administration to man when given alone and concomitantly with clopidogrel or clopidogrel and aspirin. With its unique mechanism of action, it was anticipated that DG-041 would potentiate inhibition of platelet function when given in combination with clopidogrel without materially increasing bleeding time. Initially, in-vitro studies were performed to determine inhibitory effects of DG-041 (3 µM) used alone or in combination with the P2Y12 antagonist cangrelor (1 µM), both without and with aspirin (100 µM). Platelet aggregation and P-selectin expression were measured in whole blood (n = 10) following stimulation with the thromboxane A2 (TXA2) mimetic U46619 (0.3 or 1 µM) in combination with either the EP3 agonist sulprostone (0.1 µM), or PGE2 (1 µM). DG-041 alone partially inhibited platelet function in-vitro, as did cangrelor. Addition of both DG-041 and cangrelor in combination provided significantly greater inhibition. An ex-vivo study was then performed using the same experimental approaches. This clinical study was a prospective, randomised, blinded (for DG-041/matching placebo), blocked, crossover study designed to compare the effects of DG-041, clopidogrel, or the combination of DG-041 with either clopidogrel or clopidogrel and aspirin. Healthy volunteers (n = 42) were randomly assigned to receive no background treatment, clopidogrel (300 mg loading dose plus 75 mg daily) or clopidogrel and aspirin (75 mg daily) for 10 days alongside DG-041 (200 mg twice daily) or placebo for 5 days, crossed over to placebo or DG-041 for the next 5 days. Platelet effects and bleeding time were measured at baseline, days 5 and 10. DG-041 partially inhibited platelet function ex-vivo, as did clopidogrel, while administration of both DG-041 and clopidogrel provided significantly greater inhibition. Administration of DG-041 alone did not increase bleeding time, and did not significantly affect the increased bleeding time seen with clopidogrel or clopidogrel with aspirin. Using these experimental approaches, the antiplatelet effects of DG-041 and a P2Y12 antagonist used alone and in combination can be determined both in-vitro and ex-vivo. Results show inhibitory effects of DG-041 on platelet function acting via EP3 receptor blockade, confirmed to be additional to those brought about by P2Y12 blockade. In both in-vitro and ex-vivo studies, aspirin neither promoted nor negated the effects of the other drugs.

Dissociation of double-stranded poly(I) . poly(C) by cis-diammine-dichloro-Pt(II)

The covalent binding of cis-Pt(NH3)2Cl2 on the double stranded poly(I) . poly(C) induced an irreversible dissociation of the two strands. This dissociation was evidenced mainly by poly(I)-Agarose affinity chromatography which allowed to recover free strands of cis-Pt(NH3)2Cl2-poly(I) from a cis-Pt(NH3)2Cl2-poly(I) . poly(C) complex, by density equilibrium centrifugation where free poly(C) could be isolated, and by acid titrations of the metal-poly(I) . poly(C) complexes. The separation of the two strands of the polyribonucleotide upon cis-Pt(NH3)2Cl2 fixation was shown not to exceed 90--95%. A dissociation curve of the polynucleotide double helix as a function of the amount of bound cis-Pt(NH3)2Cl2 was determined and was shown to be of a characteristic cooperative effect. The fixation of the paltinum compound to poly(I) . poly(C) seemed also to be cooperative.

Reduction of Side Effects by Combining Clozapine with Amisulpride: Case Report and Short Review of Clozapine-Induced Hypersalivation

Side effects from a high-dose clozapine treatment for a schizophrenic patient led to massive compliance problems. The dose of clozapine could be halved without recurrence of an acute psychotic symptomatology by concomitantly administering amisulpride. The side effects, especially hypersalivation, disappeared almost entirely, which in turn led to good compliance. In a short review we would like to present the pathophysiology and therapeutic options of clozapine-induced hypersalivation.