Completed suicides of citalopram users-the role of CYP genotypes and adverse drug interactions.

Depression is known to be a risk factor for suicide. Currently, the most used antidepressants are selective serotonin reuptake inhibitors (SSRIs). Not all users, however, benefit from them. In such cases, treatment failure can be explained in part by genetic differences. In this study, we investigated the role of pharmacogenetic factors in citalopram-positive completed suicides (n = 349). Since citalopram is metabolized by CYP2C19 and CYP2D6 enzymes, the study population was genotyped for clinically relevant CYP2C19 and CYP2D6 polymorphisms and CYP2D6 copy number variation. To assess genetic differences between suicide cases and Finns in general, Finnish population samples (n = 855) were used as controls. Also, the role of drug interactions among suicide cases was evaluated. We found enrichment of a combined group of genetically predicted poor and ultrarapid metabolizer phenotypes (gMPs) of CYP2C19 among suicide victims compared to controls 0.356 [0.31-0.41] vs. 0.265 [0.24-0.30] (p = 0.0065). In CYP2D6 gMPs, there was no difference between cases and controls when the study population was analyzed as a whole. However, there were significantly more poor metabolizers among females who committed suicide by poisoning compared to female controls. In 8% of all drug poisoning deaths, lifetime drug-drug interaction was evaluated having a contribution to the fatal outcome. From clinical perspective, pharmacogenetic testing prior to initiation of SSRI drug could be beneficial. It may also be useful in medico-legal settings as it may elucidate obscure poisoning cases. Also, the possibility of unintentional drug interactions should be taken into account in drug poisoning deaths.

Ketamine and norketamine attenuate oxycodone tolerance markedly less than that of morphine: from behaviour to drug availability.

BACKGROUND: Ketamine attenuates morphine tolerance by antagonising N-methyl-d-aspartate receptors. However, a pharmacokinetic interaction between morphine and ketamine has also been suggested. The interaction between oxycodone and ketamine is unclear. We studied the effects of ketamine and norketamine on the attenuation of morphine and oxycodone tolerance focusing on both the pharmacodynamic and pharmacokinetic interactions. METHODS: Morphine 9.6 mg day-1 or oxycodone 3.6 mg day-1 was delivered to Sprague-Dawley rats by subcutaneous pumps. Once tolerance had developed, the rats received subcutaneous injections of ketamine or norketamine. Tail-flick, hot-plate, and rotarod tests were performed. Drug concentrations were measured with high-performance liquid chromatography-tandem mass spectrometry. RESULTS: Anti-nociceptive tolerance to morphine and oxycodone developed similarly by Day 6. Acute ketamine 10 mg kg-1 and norketamine 30 mg kg-1 attenuated morphine tolerance for 120 and 150 min, respectively, whereas in oxycodone-tolerant rats the effect lasted only 60 min. Both ketamine and norketamine increased the brain and serum concentrations of morphine, and inhibited its metabolism to morphine-3-glucuronide, whereas oxycodone concentrations were not changed. Morphine, but not oxycodone, pretreatment increased the brain and serum concentrations of ketamine and norketamine. Ketamine, but not norketamine, significantly impaired the motor coordination. CONCLUSIONS: Ketamine and norketamine attenuated morphine tolerance more effectively than oxycodone tolerance. Ketamine and norketamine increased morphine, but not oxycodone brain concentrations, which may partly explain this difference. Norketamine is effective in attenuating morphine tolerance with minor effects on motor coordination. These results warrant pharmacokinetic studies in patients who are co-treated with ketamine and opioids.

Charge separation and charge recombination photophysical studies in a series of perylene-C60 linear and cyclic dyads.

A new donor­acceptor doubly bridged perylenediimide­fullerene dyad (PDI­C60, DB-3), where the perylenediimide (PDI) acts as a donor, has been synthesized and studied by time-resolved absorption spectroscopy. The DB-3 undergoes an electron transfer (ET) in both polar and non-polar media under photo-excitation. Structurally the DB-3 dyad resembles four other recently studied dyads (R. K. Dubey et al., Chem. Eur. J., 2013, 19, 6791­6806). Analysis of the ET reactions in this series of dyads was carried out in frame of both classic and semi-quantum ET theories. The result of the analysis for DB-3 suggests that the electronic coupling for the ET reaction is roughly 0.005 eV, internal reorganization energy is 0.16 eV, and outer sphere or solvent reorganization energy is 0.5 and 0.3 eV in benzonitrile and toluene, respectively.

Temporal variation in coat colour (genotypes) supports major changes in the Nordic cattle population after Iron Age.

Variation in coat colour genotypes of archaeological cattle samples from Finland was studied by sequencing 69 base pairs of the extension locus (melanocortin 1-receptor, MC1R) targeting both a transition and a deletion defining the three main alleles, such as dominant black (E(D) ), wild type (E(+) ) and recessive red (e). The 69-bp MC1R sequence was successfully analysed from 23 ancient (1000-1800 AD) samples. All three main alleles and genotype combinations were detected with allele frequencies of 0.26, 0.17 and 0.57 for E(D) , E(+) and e respectively. Recessive red and dominant black alleles were detected in both sexes. According to the best of our knowledge, this is the first ancient DNA study defining all three main MC1R alleles. Observed MC1R alleles are in agreement with calculated phenotype frequencies from historical sources. The division of ancient Finnish cattle population into modern Finnish breeds with settled colours was dated to the 20th century. From the existing genotyped populations in Europe (43 breeds, n = 2360), the closest match to ancient MC1R genotype frequencies was with the Norwegian native multicoloured breeds. In combined published genotype data of ancient (n = 147) and genotypes and phenotypes of modern Nordic cattle (n = 738), MC1R allele frequencies showed temporal changes similar to neutral mitochondrial DNA and Y-chromosomal haplotypes analysed earlier. All three markers indicate major change in genotypes in Nordic cattle from the Late Iron Age to the Medieval period followed by slower change through the historical periods until the present.

Maternal and paternal genetic diversity of ancient sheep in Estonia from the Late Bronze Age to the post-medieval period and comparison with other regions in Eurasia.

Sheep were among the first domesticated animals to appear in Estonia in the late Neolithic and became one of the most widespread livestock species in the region from the Late Bronze Age onwards. However, the origin and historical expansion of local sheep populations in Estonia remain poorly understood. Here, we analysed fragments of the hypervariable D-loop of mitochondrial DNA (mtDNA; 213 bp) and the Y-chromosome SRY gene (130 bp) extracted from 31 archaeological sheep bones dated from approximately 800 BC to 1700 AD. The ancient DNA data of sheep from Estonia were compared with ancient sheep from Finland as well as a set of contemporary sheep breeds from across Eurasia in order to place them in a wider phylogeographical context. The analysis shows that: (i) 24 successfully amplified and analysed mtDNA sequences of ancient sheep cluster into two haplogroups, A and B, of which B is predominant; (ii) four of the ancient mtDNA haplotypes are novel; (iii) higher mtDNA haplotype diversity occurred during the Middle Ages as compared to other periods, a fact concordant with the historical context of expanding international trade during the Middle Ages; (iv) the proportion of rarer haplotypes declined during the expansion of sheep from the Near Eastern domestication centre to the northern European region; (v) three male samples showed the presence of the characteristic northern European haplotype, SNP G-oY1 of the Y-chromosome, and represent the earliest occurrence of this haplotype. Our results provide the first insight into the genetic diversity and phylogeographical background of ancient sheep in Estonia and provide basis for further studies on the temporal fluctuations of ancient sheep populations.

Association between fluid balance and survival in critically ill patients.

OBJECTIVE: Although the consequences of chronic fluid retention are well known, those of iatrogenic fluid retention that occurs during critical illness have not been fully determined. Therefore, we investigated the association between fluid balance and survival in a cohort of almost 16,000 individuals who survived an intensive care unit (ICU) stay in a large, urban, tertiary medical centre. DESIGN: Longitudinal analysis of fluid balance at ICU discharge and 90-day post-ICU survival. MEASUREMENTS: Associations between fluid balance during the ICU stay, determined from the electronic bedside record, and survival were tested using Cox proportional hazard models adjusted for severity of critical illness. RESULTS: There were 1827 deaths in the first 90 days after ICU discharge. Compared with the lowest quartile of discharge fluid balance [median (interquartile range) -1.5 (-3.1, -0.7) L], the highest quartile [7.6 (5.7, 10.8) L] was associated with a 35% [95% confidence interval (CI) 1.13-1.61)] higher adjusted risk of death. Fluid balance was not associated with outcome amongst individuals without congestive heart failure or renal dysfunction. Amongst patients with either comorbidity, however, fluid balance was strongly associated with outcome, with the highest quartile having a 55% (95% CI 1.24-1.95) higher adjusted risk of death than the lowest quartile. Isotonic fluid balance, defined as the difference between intravenous isotonic fluid administration and urine output, was similarly associated with 90-day outcomes. CONCLUSION: Positive fluid balance at the time of ICU discharge is associated with increased risk of death, after adjusting for markers of illness severity and chronic medical conditions, particularly in patients with underlying heart or kidney disease. Restoration of euvolaemia prior to discharge may improve survival after acute illness.

Trends in population attributable fraction of acute coronary syndrome and ischaemic stroke due to diabetes in Finland.

AIMS/HYPOTHESIS: Cardiovascular disease (CVD) event rates are decreasing, but the prevalence of diabetes is increasing. The effect of these developments on the population attributable fraction (PAF) of CVD events due to diabetes is not known. METHODS: We used country-wide healthcare registers to identify all persons aged 25-80 years treated for diabetes in Finland during 1992-2002. These data were further linked to the National Cardiovascular Disease Register to identify the first CVD events (acute coronary syndrome and ischaemic stroke) among the individuals with and without diabetes. We calculated the annual PAF of the first CVD events due to diabetes separately for men and women. RESULTS: The number of men treated for diabetes each year almost doubled during the study period from 37,073 to 69,158 between 1992 and 2002. Among women, the number increased from 42,485 to 57,372. The annual number of first CVD events in the country declined among men with diabetes from 13,436 to 12,678 and among women with diabetes from 8,658 to 7,521 between 1992 and 2002. During the same period, the PAF due to diabetes of the first CVD events increased among men from 11.4% (95% CI 10.8, 12.0%) to 13.8% (95% CI 13.2, 14.5%) and decreased among women from 20.1% (95% CI 19.2, 21.0%) to 16.9% (95% CI 15.9, 17.8%). The trends in PAF were different between the sexes (p < 0.001 for the interaction year × sex). CONCLUSIONS/INTERPRETATION: Despite the very large increase in the prevalence of diabetes, the PAF of the first CVD events due to diabetes decreased in women and increased only slightly in men.

Case fatality rates after first acute coronary syndrome in persons treated for type 2 diabetes show an improving trend.

AIMS/HYPOTHESIS: We analysed whether the prognosis of a first acute coronary syndrome (ACS) in patients treated for type 2 diabetes has improved. We also compared the trends in patients with and without diabetes. METHODS: We used national registers to identify all patients with clinically known type 2 diabetes in Finland during the years 1988 to 2002 (n = 222,940). All first-ever ACS events (n = 43,412) among these patients were identified using the Hospital Discharge Register and the Causes of Death Register. From the National Cardiovascular Disease Register we identified all first ACS attacks (n = 191,403) among non-diabetic patients in the country. Finally, we calculated annual age-standardised case fatality rates for ACS for three time periods: prehospital, days 0 to 27 and days 28 to 364 after the first ACS. RESULTS: The case fatality rate of first ACS declined significantly in both sexes at all time points considered. The declining trends were not different between patients with type 2 diabetes and those without. Among men aged 35 to 74 years, 58.5% (95% CI 57.6-59.4%) with type 2 diabetes and 44.1% (95% CI 43.8-44.5%) without diabetes had died from cardiovascular causes 1 year after their first ACS. Among women of the same age, the corresponding figures were 54.2% (95% CI 53.0-55.4%) and 36.5% (95% CI 35.9-37.1%). Men generally had higher case fatality rates than women. However, except for prehospital deaths, diabetic women had the same or even higher case fatality rates than non-diabetic men. CONCLUSIONS/INTERPRETATION: The case fatality rates for first ACS show similar improving trends in patients with type 2 diabetes and in those without. However, case fatality rates have remained higher in patients with type 2 diabetes.

ABCB1 haplotypes differentially affect the pharmacokinetics of the acid and lactone forms of simvastatin and atorvastatin.

ABCB1 haplotypes were determined in 534 healthy Finnish volunteers, of whom 24 participated in a pharmacokinetic study on simvastatin and atorvastatin. The frequencies of occurrence of haplotypes c.1236T-c.2677T-c.3435T and c.1236C-c.2677G-c.3435C were 42.7 and 34.4%, respectively. The simvastatin acid AUC(0-12h) was 60% larger, the atorvastatin AUC(0-infinity) 55% larger, and the atorvastatin half-life 24% longer in subjects with the ABCB1 TTT/TTT genotype (n = 12) than in those with the CGC/CGC genotype (n = 12) (P < 0.05), but there were no differences between the two genotypes with respect to the pharmacokinetics of the lactones of these drugs.

Effects of gemfibrozil and atorvastatin on the pharmacokinetics of repaglinide in relation to SLCO1B1 polymorphism.

In a randomized crossover study, 24 SLCO181-genotyped healthy volunteers were given daily doses of 1,200 mg gemfibrozil, 40 mg atorvastatin, or placebo, followed by 0.25 mg of repaglinide on day 3. The mean increase in the repaglinide area under the plasma concentration-time curve from 0 h to infinity (AUC(0-infinity)) produced by gemfibrozil was larger in individuals with the SLCO1B1 c.521CC genotype (n = 6) than in those with the c.521TC (n = 6) and c.521TT (n = 12) genotypes, by factors of 1.56 (P = 0.004) and 1.54 (P = 0.002), respectively. Gemfibrozil prolonged the repaglinide elimination half-life 1.43 times more in the c.521 CC group than in the c.521TT group (P = 0.047), but no differences were seen in the effects on peak plasma concentration (C(max)). While on gemfibrozil, the minimum blood glucose concentration after repaglinide intake was 19% lower in the c.521CC participants than in the c.521TT participants (P = 0.009). In the c.521TT group, atorvastatin intake had the effect of increasing repaglinide Cmax and AUC(0-infinity) by41% (P = 0.001) and 18% (P = 0.033), respectively. In conclusion, the extent of gemfibrozil-repaglinide interaction depends on SLCO1B1 genotype. Atorvastatin raises plasma repaglinide concentrations, probably by inhibiting organic anion transporting polypeptide 1B1 (OATP1B1).

Characterization of novel CYP2C8 haplotypes and their contribution to paclitaxel and repaglinide metabolism.

Cytochrome P450 2C8 (CYP2C8) plays a major role in the metabolism of therapeutically important drugs which exhibit large interindividual differences in their pharmacokinetics. In order to evaluate any genetic influence on this variation, a CYP2C8 phenotype-genotype evaluation was carried out in Caucasians. Two novel CYP2C8 haplotypes, named B and C with frequencies of 24 and 22% in Caucasians, respectively, were identified and caused a significantly increased and reduced paclitaxel 6alpha-hydroxylation, respectively, as evident from analyses of 49 human liver samples. In healthy white subjects, CYP2C8*3 and the two novel haplotypes significantly influenced repaglinide pharmacokinetics in SLCO1B1c.521T/C heterozygous individuals: haplotype B was associated with reduced and haplotype C with increased repaglinide AUC (0-infinity). Functional studies suggested -271C>A (CYP2C8*1B) as a causative SNP in haplotype B. In conclusion, two novel common CYP2C8 haplotypes were identified and significantly associated with altered rate of CYP2C8-dependent drug metabolism in vitro and in vivo.

Weakened [corrected] taste-LPS association during endotoxin tolerance.

In naive individuals, the administration of bacterial lipopolysaccharide (LPS) provokes a rapid systemic increase in pro-inflammatory cytokines such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6, inducing an acute phase response including sickness behavior. Strong associative learning occurs when relevant gustatory/olfactory stimuli precede the activation of the immune system, affecting long-term individual food selection and nutritional strategies. Repeated LPS administration results in the development of an endotoxin tolerance status, characterized by a drastic reduction in the LPS-induced cytokine response. Here we investigated how the postprandial categorization of a relevant taste (0.2% saccharin) changed after administration of a high dose of LPS (0.5 mg/kg i.p.) in LPS-tolerant animals. Determination of the consummatory fluid intake revealed that, in contrast to LPS-naive rats, taste-LPS association did not occur during endotoxin tolerance. Ninety minutes after the single association trial, the plasma responses of TNF-alpha, IL-1beta and IL-6 were completely blunted in LPS-tolerant animals, which also resulted in low LPS-adipsogenic and LPS-anorexic effects. These findings indicate that an identical immune challenge can result in completely different neuro-behavioral consequences depending on the immune history of the individual, thus revealing part of the complex interconnection between the immune and neuro-endocrine systems in regulating food selection and consumption during the infectious process.

The effect of a cannula milk sampling technique on the microbiological diagnosis of bovine mastitis.

Two methods of collecting milk samples from mastitic bovine mammary quarters were compared. Samples were taken in a consistent order in which standard aseptic technique sampling was done first, followed by insertion of a sterile cannula through the teat canal and collection of a second sample. Microbiological results of those two sampling techniques were compared. Milk samples were analysed using multiplex real-time polymerase chain reaction (PCR). The cannula technique produced a reduced number of microbial species or groups of species per sample compared with conventional sampling. Staphylococcus spp. were the most common species identified and were detected more often during conventional sampling than with cannula sampling. Staphylococcus spp. identified in milk samples could also have originated from the teat canal without being present in the milk. The number of samples positive for Trueperella pyogenes or yeasts in the conventional samples was twice as high as in the cannula samples, indicating that the presence of Trueperella pyogenes and yeast species should not necessarily be interpreted as being the causative agents of bovine intra-mammary infections (IMI).

Effects of transitory lingual nerve impairment on speech: an acoustic study of sibilant sound /s/.

By measuring spectral characteristics of the sibilant /s/ this study investigated whether the reduced orosensory feedback caused by lingual nerve impairment affects the acoustics and articulation of sibilants. A further goal was to examine speakers' capability to compensate for the deviant control of the delicate movements required for the proper production of /s/ by experimentally modifying the function of the tongue in a way that reduces the necessary somatosensory information in articulation. Five healthy men with no speech, language or hearing abnormalities were enrolled. They produced the sibilant /s/ in a variety of phonetic contexts in two sessions: first in normal conditions and then with local anaesthesia of the right lingual nerve. From the speech samples, the spectral characteristics of the sibilant sound (i.e. the centre of gravity, standard deviation, skewness and kurtosis) were analysed acoustically. The results showed that the reduced tactile sensation has effects on the tongue function resulting in individual and variable spectral alterations. The variation between different speakers indicates individual ability to compensate for the effects caused by the sensory dysfunction of the tongue. It seems, therefore, that the compensatory mechanisms for speech production are highly speaker-dependent.

Pregabalin enhances the antinociceptive effect of oxycodone and morphine in thermal models of nociception in the rat without any pharmacokinetic interactions.

BACKGROUND: Oxycodone is increasingly being used in combination with pregabalin. Pregabalin use is prevalent in opioid-dependent individuals. A high number of deaths caused by the co-use of gabapentinoids and opioids occur. It is not known whether pregabalin affects concentrations of oxycodone or morphine in the central nervous system. METHODS: Effects of pregabalin on acute oxycodone or morphine-induced antinociception, tolerance and sedation were studied using tail-flick, hot plate and rotarod tests in male Sprague-Dawley rats. Concentrations of pregabalin, opioids and their major metabolites in the brain were quantified by mass spectrometry. RESULTS: In the hot plate test, morphine (2.5 mg/kg, s.c.) caused antinociception of 28% maximum possible effect (MPE), whereas pregabalin (50 mg/kg, i.p.) produced 8-10% MPE. Co-administration of pregabalin and morphine resulted in antinociception of 63% MPE. Oxycodone (0.6 mg/kg s.c.) produced antinociception of 18% MPE, which increased to 39% MPE after co-administration with pregabalin. When pregabalin 10 mg/kg was administered before oxycodone (0.6 mg/kg, s.c.) or morphine (2.5 mg/kg), only the effect of oxycodone was potentiated in the tail-flick and the hot plate tests. Brain concentrations of the opioids, their major metabolites and pregabalin were unchanged. Pregabalin co-administration (50 mg/kg, i.p., once daily) did not prevent the development of morphine tolerance. CONCLUSIONS: Pregabalin potentiated antinociceptive and sedative effects of oxycodone and morphine in acute nociception. Co-administration of pregabalin with the opioids did not affect the brain concentrations of oxycodone or morphine. Pregabalin did not prevent morphine tolerance.

Intravascular adenovirus-mediated VEGF-C gene transfer reduces neointima formation in balloon-denuded rabbit aorta.

BACKGROUND: Gene transfer to the vessel wall may provide new possibilities for the treatment of vascular disorders, such as postangioplasty restenosis. In this study, we analyzed the effects of adenovirus-mediated vascular endothelial growth factor (VEGF)-C gene transfer on neointima formation after endothelial denudation in rabbits. For comparison, a second group was treated with VEGF-A adenovirus and a third group with lacZ adenovirus. Clinical-grade adenoviruses were used for the study. METHODS AND RESULTS: Aortas of cholesterol-fed New Zealand White rabbits were balloon-denuded, and gene transfer was performed 3 days later. Animals were euthanized 2 and 4 weeks after the gene transfer, and intima/media ratio (I/M), histology, and cell proliferation were analyzed. Two weeks after the gene transfer, I/M in the lacZ-transfected control group was 0. 57+/-0.04. VEGF-C gene transfer reduced I/M to 0.38+/-0.02 (P:<0.05 versus lacZ group). I/M in VEGF-A-treated animals was 0.49+/-0.17 (P:=NS). The tendency that both VEGF groups had smaller I/M persisted at the 4-week time point, when the lacZ group had an I/M of 0.73+/-0.16, the VEGF-C group 0.44+/-0.14, and the VEGF-A group 0. 63+/-0.21 (P:=NS). Expression of VEGF receptors 1, 2, and 3 was detected in the vessel wall by immunocytochemistry and in situ hybridization. As an additional control, the effect of adenovirus on cell proliferation was analyzed by performing gene transfer to intact aorta without endothelial denudation. No differences were seen in smooth muscle cell proliferation or I/M between lacZ adenovirus and 0.9% saline-treated animals. CONCLUSIONS: Adenovirus-mediated VEGF-C gene transfer may be useful for the treatment of postangioplasty restenosis and vessel wall thickening after vascular manipulations.

Angiogenesis, vascular endothelial growth factor and platelet-derived growth factor-BB expression, iron deposition, and oxidation-specific epitopes in stented human coronary arteries.

Pathogenesis of in-stent restenosis remains poorly understood because information from human histopathologic studies is scarce. We used an improved saw-grinding and cutting method on methacrylate-embedded samples containing metal stents, which allows in situ hybridization and immunohistochemical analysis of in-stent restenosis. Twenty-one samples were collected 3 hours to 3 years after stenting from 6 patients aged 36 to 81 years. Except in very early samples collected within hours after the stent deployment, neovascularization was present in all segments studied. At advanced stages, extensive neovascularization was located mainly at the luminal side of the stent struts and was only rarely accompanied by inflammatory cells. The neovessels colocalized with vascular endothelial growth factor (VEGF)-A mRNA and protein expression as well as with iron deposits and oxidation-specific epitopes, which imply the presence of chronic oxidative stress. VEGF-A expression was detected in the same areas containing macrophages, endothelial cells, and, to a lesser extent, smooth muscle cells, which also showed platelet-derived growth factor-BB expression. We conclude that in-stent restenosis features neovascularization, VEGF-A and platelet-derived growth factor-BB expression, and iron deposition, which is most probably derived from microhemorrhages. These mechanisms may play an important role in the development of neointimal thickening and could provide useful targets for the prevention and treatment of in-stent restenosis.

Liver function tests in diabetic patients.

Nine different liver function tests (LFT) were assessed in 175 unselected diabetic outpatients stabilized on diet, insulin, or oral hypoglycemic drugs. In another group of 72 diabetic inpatients having diagnostic liver biopsy, relationships between LFT and histologic changes in the liver were investigated. Abnormalities in at least one of the tests were noted in 57% of the outpatients, and two tests gave pathologic results in 27%. The non-insulin-dependent diabetic patients more often had abnormal LFT results than did the insulin-dependent diabetic patients. Serum chenodeoxycholic acid concentrations were increased in 27%, gamma-glutamyl transpeptidase (gGT) activities in 19%, and alanine aminotransferase (Alt) activities in 17% of the outpatients, but the increases were rarely more than twice the upper limit of normal. In multivariate analysis, outpatients who were overweight, showed poor diabetes control during a short duration of diabetes controlled by treatment with diet or oral agents, and had a mature age at onset of diabetes displayed the most significant clinical explanatory variables associated with abnormal Alt. In the inpatients, the percentages of abnormal Alt and gGT results were augmented, along with increasing severity of histologic changes, but the mean values of Alt and gGT did not differ significantly between the various histologic groups. In addition, the diabetic patients with nonspecific inflammatory changes or increase in liver fibrosis often showed normal or only minor elevations in these test values.

Ketamine coadministration attenuates morphine tolerance and leads to increased brain concentrations of both drugs in the rat.

BACKGROUND AND PURPOSE: The effects of ketamine in attenuating morphine tolerance have been suggested to result from a pharmacodynamic interaction. We studied whether ketamine might increase brain morphine concentrations in acute coadministration, in morphine tolerance and morphine withdrawal. EXPERIMENTAL APPROACH: Morphine minipumps (6 mg·day(-1) ) induced tolerance during 5 days in Sprague-Dawley rats, after which s.c. ketamine (10 mg·kg(-1) ) was administered. Tail flick, hot plate and rotarod tests were used for behavioural testing. Serum levels and whole tissue brain and liver concentrations of morphine, morphine-3-glucuronide, ketamine and norketamine were measured using HPLC-tandem mass spectrometry. KEY RESULTS: In morphine-naïve rats, ketamine caused no antinociception whereas in morphine-tolerant rats there was significant antinociception (57% maximum possible effect in the tail flick test 90 min after administration) lasting up to 150 min. In the brain of morphine-tolerant ketamine-treated rats, the morphine, ketamine and norketamine concentrations were 2.1-, 1.4- and 3.4-fold, respectively, compared with the rats treated with morphine or ketamine only. In the liver of morphine-tolerant ketamine-treated rats, ketamine concentration was sixfold compared with morphine-naïve rats. After a 2 day morphine withdrawal period, smaller but parallel concentration changes were observed. In acute coadministration, ketamine increased the brain morphine concentration by 20%, but no increase in ketamine concentrations or increased antinociception was observed. CONCLUSIONS AND IMPLICATIONS: The ability of ketamine to induce antinociception in rats made tolerant to morphine may also be due to increased brain concentrations of morphine, ketamine and norketamine. The relevance of these findings needs to be assessed in humans.

Carboxylesterase 1 c.428G>A single nucleotide variation increases the antiplatelet effects of clopidogrel by reducing its hydrolysis in humans.

Carboxylesterase 1 (CES1) hydrolyzes the prodrug clopidogrel to an inactive carboxylic acid metabolite. We studied the pharmacokinetics and pharmacodynamics of 600 mg oral clopidogrel in healthy white volunteers, including 10 carriers and 12 noncarriers of CES1 c.428G>A (p.Gly143Glu, rs71647871) single nucleotide variation (SNV). Clopidogrel carboxylic acid to clopidogrel area under the plasma concentration-time curve from 0 hours to infinity (AUC0-∞ ) ratio was 53% less in CES1 c.428G>A carriers than in noncarriers (P = 0.009), indicating impaired hydrolysis of clopidogrel. Consequently, the AUC0-∞ of clopidogrel and its active metabolite were 123% (P = 0.004) and 67% (P = 0.009) larger in the c.428G>A carriers than in noncarriers. Consistent with these findings, the average inhibition of P2Y12 -mediated platelet aggregation 0-12 hours after clopidogrel intake was 19 percentage points higher in the c.428G>A carriers than in noncarriers (P = 0.036). In conclusion, the CES1 c.428G>A SNV increases clopidogrel active metabolite concentrations and antiplatelet effects by reducing clopidogrel hydrolysis to inactive metabolites.