Aminomethyl-Derived Beta Secretase (BACE1) Inhibitors: Engaging Gly230 without an Anilide Functionality

A growing subset of β-secretase (BACE1) inhibitors for the treatment of Alzheimer’s disease (AD) utilizes an anilide chemotype that engages a key residue (Gly230) in the BACE1 binding site. Although the anilide moiety affords excellent potency, it simultaneously introduces a third hydrogen bond donor that limits brain availability and provides a potential metabolic site leading to the formation of an aniline, a structural motif of prospective safety concern. We report herein an alternative aminomethyl linker that delivers similar potency and improved brain penetration relative to the amide moiety. Optimization of this series identified analogues with an excellent balance of ADME properties and potency; however, potential drug–drug interactions (DDI) were predicted based on CYP 2D6 affinities. Generation and analysis of key BACE1 and CYP 2D6 crystal structures identified strategies to obviate the DDI liability, leading to compound 16, which exhibits robust in vivo efficacy as a BACE1 inhibitor.

Utilizing structures of CYP2D6 and BACE1 complexes to reduce risk of drug-drug interactions with a novel series of centrally efficacious BACE1 inhibitors

In recent years, the first generation of β-secretase (BACE1) inhibitors advanced into clinical development for the treatment of Alzheimer’s disease (AD). However, the alignment of drug-like properties and selectivity remains a major challenge. Herein, we describe the discovery of a novel class of potent, low clearance, CNS penetrant BACE1 inhibitors represented by thioamidine 5. Further profiling suggested that a high fraction of the metabolism (>95%) was due to CYP2D6, increasing the potential risk for victim-based drug–drug interactions (DDI) and variable exposure in the clinic due to the polymorphic nature of this enzyme. To guide future design, we solved crystal structures of CYP2D6 complexes with substrate 5 and its corresponding metabolic product pyrazole 6, which provided insight into the binding mode and movements between substrate/inhibitor complexes. Guided by the BACE1 and CYP2D6 crystal structures, we designed and synthesized analogues with reduced risk for DDI, central efficacy, and improved hERG therapeutic margins.

Erratum to: 56 SINGLE LAYER CENTRIFUGATION THROUGH PURESPERM® 80 IMPROVES QUALITY OF CRYOPRESERVED DOG SPERMATOZOA

Density gradient centrifugation with PureSperm® (PureSperm® 40+PureSperm® 80; Nidacon International, Mölndal, Sweden) has been satisfactorily used to enhance the quality of dog semen samples; however, no studies have been performed on the effect of single layer centrifugation (SLC) with PureSperm® on frozen–thawed dog semen. The aim of this study was to investigate if SLC with PureSperm® 80 can improve the post-thaw semen quality of dog. Semen from 5 dogs was collected by digital manipulation. Two ejaculates from each dog were centrifuged with Tris-based extender, supernatant was removed, and sperm pellet was suspended to a final concentration of 300–400×106spermmL–1 with CaniPROTM Freeze A plus 20% egg yolk at 22°C. Extended semen was cooled to 5°C within an hour and then diluted to a final concentration of 150–200×106spermmL–1 in CaniPROTM Freeze B plus 20% egg yolk at 5°C, loaded in 0.5-mL plastic straws and frozen horizontally in ranks placed 4cm above the surface of liquid nitrogen vapors for 10min, after which they were directly placed in liquid nitrogen. After 24 to 48h of storage, straws were thawed in a water bath at 37°C for 30s. After thawing, semen samples were divided in 2 aliquots: one of them was used as control and the other one was processed by SLC PureSperm® 80. Assessment of sperm motility (assessed by computerized-assisted semen analysis), morphology (Diff-Quick staining), and viability [triple fluorescent stain of propidium iodine/isothiocyanate-labeled peanut (Arachis hypogaea) agglutinin/Rhodamine 123] were evaluated in control and treated semen samples. Data were studied by ANOVA. Results are expressed as mean ± SEM. Significant (P<0.001) differences were found between SLC-treated and control semen for sperm motility (percentage of total motile spermatozoa: 93.65±0.05 v. 83.79±0.13; percentage of progressive motile spermatozoa: 79.38±6.66 v. 54.61±16.11), morphology (86.45±0.01 v. 83.51±0.01), and viability (percentage of viable sperm with an intact acrosome: 58.32±0.04 v. 36.50±0.17; percentage of viable sperm with an acrosome reaction: 2.81±0.01 v. 9.74±0.21). Based on our results, we can conclude that SLC with PureSperm® 80 is an alternative and successful method for improving the quality of frozen–thawed dog spermatozoa, selecting good-quality spermatozoa (motile, morphologically normal, viable, and acrosome intact spermatozoa) from the rest of the semen sample.

Erratum to: 56 SINGLE LAYER CENTRIFUGATION THROUGH PURESPERM® 80 IMPROVES QUALITY OF CRYOPRESERVED DOG SPERMATOZOA

Density gradient centrifugation with PureSperm® (PureSperm® 40 + PureSperm® 80; Nidacon International, Mölndal, Sweden) has been satisfactorily used to enhance the quality of dog semen samples; however, no studies have been performed on the effect of single layer centrifugation (SLC) with PureSperm® on frozen–thawed dog semen. The aim of this study was to investigate if SLC with PureSperm® 80 can improve the post-thaw semen quality of dog. Semen from 5 dogs was collected by digital manipulation. Two ejaculates from each dog were centrifuged with Tris-based extender, supernatant was removed, and sperm pellet was suspended to a final concentration of 300–400 × 106 sperm mL–1 with CaniPROTM Freeze A plus 20% egg yolk at 22°C. Extended semen was cooled to 5°C within an hour and then diluted to a final concentration of 150–200 × 106 sperm mL–1 in CaniPROTM Freeze B plus 20% egg yolk at 5°C, loaded in 0.5-mL plastic straws and frozen horizontally in ranks placed 4 cm above the surface of liquid nitrogen vapors for 10 min, after which they were directly placed in liquid nitrogen. After 24 to 48 h of storage, straws were thawed in a water bath at 37°C for 30 s. After thawing, semen samples were divided in 2 aliquots: one of them was used as control and the other one was processed by SLC PureSperm® 80. Assessment of sperm motility (assessed by computerized-assisted semen analysis), morphology (Diff-Quick staining), and viability [triple fluorescent stain of propidium iodine/isothiocyanate-labeled peanut (Arachis hypogaea) agglutinin/Rhodamine 123] were evaluated in control and treated semen samples. Data were studied by ANOVA. Results are expressed as mean ± SEM. Significant (P < 0.001) differences were found between SLC-treated and control semen for sperm motility (percentage of total motile spermatozoa: 93.65 ± 0.05 v. 83.79 ± 0.13; percentage of progressive motile spermatozoa: 79.38 ± 6.66 v. 54.61 ± 16.11), morphology (86.45 ± 0.01 v. 83.51 ± 0.01), and viability (percentage of viable sperm with an intact acrosome: 58.32 ± 0.04 v. 36.50 ± 0.17; percentage of viable sperm with an acrosome reaction: 2.81 ± 0.01 v. 9.74 ± 0.21). Based on our results, we can conclude that SLC with PureSperm® 80 is an alternative and successful method for improving the quality of frozen–thawed dog spermatozoa, selecting good-quality spermatozoa (motile, morphologically normal, viable, and acrosome intact spermatozoa) from the rest of the semen sample.

Alcohol consumption and risk of type 2 diabetes in European men and women: influence of beverage type and body size The EPIC-InterAct study

OBJECTIVE

To investigate the association between alcohol consumption and type 2 diabetes, and determine whether this is modified by sex, body mass index (BMI) and beverage type.

DESIGN

Multicentre prospective case-cohort study.

SETTING

Eight countries from the European Prospective Investigation into Cancer and Nutrition cohort.

SUBJECTS

A representative baseline sample of 16 154 participants and 12 403 incident cases of type 2 diabetes.

INTERVENTIONS

Alcohol consumption assessed using validated dietary questionnaires.

MAIN OUTCOME MEASURES

Occurrence of type 2 diabetes based on multiple sources (mainly self-reports), verified against medical information.

RESULTS

Amongst men, moderate alcohol consumption was nonsignificantly associated with a lower incidence of diabetes with a hazard ratio (HR) of 0.90 (95% CI: 0.78-1.05) for 6.1-12.0 versus 0.1-6.0 g day(-1) , adjusted for dietary and diabetes risk factors. However, the lowest risk was observed at higher intakes of 24.1-96.0 g day(-1) with an HR of 0.86 (95% CI: 0.75-0.98). Amongst women, moderate alcohol consumption was associated with a lower incidence of diabetes with a hazard ratio of 0.82 (95% CI: 0.72-0.92) for 6.1-12.0 g day(-1) (P interaction gender <0.01). The inverse association between alcohol consumption and diabetes was more pronounced amongst overweight (BMI ≥ 25 kg m(-2) ) than normal-weight men and women (P interaction < 0.05). Adjusting for waist and hip circumference did not alter the results for men, but attenuated the association for women (HR=0.90, 95% CI: 0.79-1.03 for 6.1-12.0 g day(-1) ). Wine consumption for men and fortified wine consumption for women were most strongly associated with a reduced risk of diabetes.

CONCLUSIONS

The results of this study show that moderate alcohol consumption is associated with a lower risk of type 2 diabetes amongst women only. However, this risk reduction is in part explained by fat distribution. The relation between alcohol consumption and type 2 diabetes was stronger for overweight than normal-weight women and men.

Long-lasting neuroprotection and neurological improvement in stroke models with new, potent and brain permeable inhibitors of poly(ADP-ribose) polymerase

BACKGROUND AND PURPOSES

Thienyl-isoquinolone (TIQ-A) is a relatively potent PARP inhibitor able to reduce post-ischaemic neuronal death in vitro. Here we have studied, in different stroke models in vivo, the neuroprotective properties of DAMTIQ and HYDAMTIQ, two TIQ-A derivatives able to reach the brain and to inhibit PARP-1 and PARP-2.

EXPERIMENTAL APPROACH

Studies were carried out in (i) transient (2 h) middle cerebral artery occlusion (tMCAO), (ii) permanent MCAO (pMCAO) and (iii) electrocoagulation of the distal portion of MCA in conjunction with transient (90 min) bilateral carotid occlusion (focal cortical ischaemia).

KEY RESULTS

In male rats with tMCAO, HYDAMTIQ (0.1-10 mg·kg(-1)) injected i.p. three times, starting 4 h after MCAO, reduced infarct volumes by up to 70%, reduced the loss of body weight by up to 60% and attenuated the neurological impairment by up to 40%. In age-matched female rats, HYDAMTIQ also reduced brain damage. Protection, however, was less pronounced than in the male rats. In animals with pMCAO, HYDAMTIQ administered 30 min after MCAO reduced infarct volumes by approximately 40%. In animals with focal cortical ischaemia, HYDAMTIQ treatment decreased post-ischaemic accumulation of PAR (the product of PARP activity) and the presence of OX42-positive inflammatory cells in the ischaemic cortex. It also reduced sensorimotor deficits for up to 90 days after MCAO.

CONCLUSION AND IMPLICATIONS

Our results show that HYDAMTIQ is a potent PARP inhibitor that conferred robust neuroprotection and long-lasting improvement of post-stroke neurological deficits.

A dysregulated endocannabinoid-eicosanoid network supports pathogenesis in a mouse model of Alzheimer's disease

Although inflammation in the brain is meant as a defense mechanism against neurotoxic stimuli, increasing evidence suggests that uncontrolled, chronic, and persistent inflammation contributes to neurodegeneration. Most neurodegenerative diseases have now been associated with chronic inflammation, including Alzheimer's disease (AD). Whether anti-inflammatory approaches can be used to treat AD, however, is a major unanswered question. We recently demonstrated that monoacylglycerol lipase (MAGL) hydrolyzes endocannabinoids to generate the primary arachidonic acid pool for neuroinflammatory prostaglandins. In this study, we show that genetic inactivation of MAGL attenuates neuroinflammation and lowers amyloid β levels and plaques in an AD mouse model. We also find that pharmacological blockade of MAGL recapitulates the cytokine-lowering effects through reduced prostaglandin production, rather than enhanced endocannabinoid signaling. Our findings thus reveal a role of MAGL in modulating neuroinflammation and amyloidosis in AD etiology and put forth MAGL inhibitors as a potential next-generation strategy for combating AD.

Ablation of the locus coeruleus increases oxidative stress in tg-2576 transgenic but not wild-type mice

Mice transgenic for production of excessive or mutant forms of beta-amyloid differ from patients with Alzheimer's disease in the degree of inflammation, oxidative damage, and alteration of intermediary metabolism, as well as the paucity or absence of neuronal atrophy and cognitive impairment. Previous observers have suggested that differences in inflammatory response reflect a discrepancy in the state of the locus coeruleus (LC), loss of which is an early change in Alzheimer's disease but which is preserved in the transgenic mice. In this paper, we extend these observations by examining the effects of the LC on markers of oxidative stress and intermediary metabolism. We compare four groups: wild-type or Tg2576 Aβ transgenic mice injected with DSP4 or vehicle. Of greatest interest were metabolites different between ablated and intact transgenics, but not between ablated and intact wild-type animals. The Tg2576_DSP4 mice were distinguished from the other three groups by oxidative stress and altered energy metabolism. These observations provide further support for the hypothesis that Tg2576 Aβ transgenic mice with this ablation may be a more congruent model of Alzheimer's disease than are transgenics with an intact LC.

Neuroprotective profile of novel SRC kinase inhibitors in rodent models of cerebral ischemia

Src kinase signaling has been implicated in multiple mechanisms of ischemic injury, including vascular endothelial growth factor (VEGF)-mediated vascular permeability that leads to vasogenic edema, a major clinical complication in stroke and brain trauma. Here we report the effects of two novel Src kinase inhibitors, 4-[(2,4-dichloro-5-methoxyphenyl)amino]-6-methoxy-7-[3-(4-methyl-1-piperazinyl)propoxy]-3-quinolinecarbonitrile (SKI-606) and 4-[(2,4-dichloro-5-methoxyphenyl)amino]-6-methoxy-7-[4-(4-methypiperazin-1-yl)but-1-ynyl]-3-quinolinecarbonitrile (SKS-927), on ischemia-induced brain infarction and short- and long-term neurological deficits. Two well established transient [transient middle cerebral artery occlusion (tMCAO)] and permanent [permanent middle cerebral artery occlusion (pMCAO)] focal ischemia models in the rat were used with drug treatments initiated up to 6 h after onset of stroke to mimic the clinical scenario. Brain penetration of Src inhibitors, their effect on blood-brain barrier integrity and VEGF signaling in human endothelial cells were also evaluated. Our results demonstrate that both agents potently block VEGF-mediated signaling in human endothelial cells, penetrate rat brain upon systemic administration, and inhibit postischemic Src activation and vascular leakage. Treatment with SKI-606 or SKS-927 (at the doses of 3-30 mg/kg i.v.) resulted in a dose-dependent reduction in infarct volume and robust protection from neurological impairments even when the therapy was initiated up to 4- to 6-h after tMCAO. Src blockade after pMCAO resulted in accelerated improvement in recovery from motor, sensory, and reflex deficits during a long-term (3 weeks) testing period poststroke. These data demonstrate that the novel Src kinase inhibitors provide effective treatment against ischemic conditions within a clinically relevant therapeutic window and may constitute a viable therapy for acute stroke.

Children's blood lead and standardized test performance response as indicators of neurotoxicity in metropolitan New Orleans elementary schools

This study analyzes pre-Katrina variation in aggregate student performance and children's blood lead (BPb) in 117 elementary school districts in metropolitan New Orleans. Fourth grade student achievement on Louisiana Educational Assessment Program (LEAP) tests were analyzed as a function of BPb for children 1-6 years old within school districts, controlling for student-teacher ratios, percent of students eligible for a free or discounted lunch, and school racial demography. Measures of performance across subject areas (English Language Arts, Science, Mathematics, and Social Studies) include school Achievement Test Scores (ATS) and indices of agreement and variation in student achievement. ATS are measured on a 5-point scale, corresponding to achievement categories of advanced=5 to unsatisfactory=1. Regression results show that median BPb (microg/dL) and percent of children with BPb > or =10 microg/dL are significantly associated with reductions in test scores across all subjects and depress variation in student performance across achievement categories. These data suggest that assisting children with improved school performance requires alleviation of pre-school Pb exposure and its associated neurotoxic damage. Cost-benefit calculations suggest that it is more cost effective to pay for onetime primary prevention instead of paying continuous expenses focused on reversing neurotoxic damage.

Tropaeolum tuberosum (Mashua) reduces testicular function: effect of different treatment times

Tropaeolum tuberosum Ruiz & Pavon, along with other several species, is an edible-tuber crop that grows in the Andean region. Folk medicine describes the use of mashua to reduce reproductive function in men. The present study aimed to evaluate the effect of mashua (1 g kg(-1)) on sperm production in rats during 7, 12, 21 and 42 days of treatment. The following parameters were assessed: reproductive organ weights, spermatid count and daily sperm production (DSP), sperm count in epididymis and sperm transit and serum testosterone levels. Freeze-dried extract of mashua had 3.7 g 100 g(-1) of benzyl glucosinolate. Mashua-treated rats showed a reduction in testicular spermatid number and DSP from day 12 to day 42; meanwhile, the effect of mashua was noted in epididymal sperm count after 12 and 42 days of treatment. In addition, epididymal sperm transit time was delayed at day 7 and it was accelerated on days 12 and 21 of treatment. No differences in serum testosterone levels were found between rats treated with vehicle and mashua after 42 days of treatment. Finally, mashua reduces testicular function after one spermatogenic cycle by reducing spermatid and sperm number, DSP and epididymal sperm transit time.

Cranberry juice improved antioxidant status without affecting bone quality in orchidectomized male rats

BACKGROUND

We reported that drinking citrus juice improves bone quality in orchidectomized senescent male rats. Because cranberry juice, like citrus, is rich in nutrients and phenolic compounds, beneficial effects of citrus juice might also be seen with cranberry juice. An experiment evaluated effect of drinking cranberry juice on bone quality in orchidectomized rats.

METHODS

Thirty-two 1-year-old male rats were randomized to two groups: a sham-control group (n=8) and an orchidectomized group (n=24). The treatments for the 4 months duration of the study were SHAM, orchidectomy (ORX), ORX+drinking either 27% or 45% cranberry juice concentrate added to drinking water. At the termination of the study, the rats were euthanized, blood was collected for plasma antioxidant status and IGF-I. The femur, tibia and the 4th lumbar were evaluated for bone quality. Total calcium and magnesium concentration in the femurs were also evaluated.

RESULTS

ORX did not affect red blood cell (RBC)-induced hemolysis despite lowering (p<0.05) plasma antioxidant capacity; reduced (p<0.05) plasma IGF-I, femoral density, femoral strength, time-induced femoral fracture, bone mineral content, bone mineral area; numerically (p=0.07) lowered 4th lumbar density; decreased (p<0.05) trabecular connectivity, trabecular number, femoral ash; increased (p<0.05) trabecular separation in comparison to the SHAM group. Drinking cranberry juice increased (p<0.05) plasma antioxidant status, protected RBC against hemolysis, but had no positive effect on bone quality or bone mineral status.

CONCLUSIONS

Cranberry juice increases plasma antioxidant status without affecting bone quality.

AMPA potentiator treatment of cognitive deficits in Alzheimer disease

OBJECTIVE

To investigate the efficacy and safety of the positive alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid modulator LY451395 in patients with mild to moderate Alzheimer disease (AD) (Mini-Mental State Examination scores 14 to 26).

METHODS

One hundred eighty-one patients were randomized to treatment in an 11-week, double-blind, placebo-controlled trial. Patients received either LY451395 0.2 mg BID for 28 days and 1.0 mg BID thereafter (n = 90) or placebo (n = 91). The primary outcome measurement was the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) with several secondary outcome measurements: Clinician's Interview-Based Impression of Change, Trail Making Part A, Stylus Tapping Test, Single Digit Modality Test, and Neuropsychiatric Inventory (NPI).

RESULTS

Baseline demographics were similar between the two groups. Patients did not show any mean change from baseline in the ADAS-Cog after treatment with LY451395 for 4 weeks (p = 0.60) or 8 weeks (p = 0.83). The only secondary outcome measurement that showed changes from baseline compared with placebo was the NPI Total Score: p = 0.06 (marginal significance) after 4 weeks of treatment and p = 0.03 after 8 weeks of treatment. Ninety-two percent of LY451395-treated patients and 95% of placebo-treated patients completed the trial. Adverse events were experienced by 83% of LY451395-treated patients and 86% of placebo-treated patients, the majority of which were rated mild in severity.

CONCLUSION

Patients treated with LY451395 did not show a statistically significant separation from patients taking placebo on the Alzheimer's Disease Assessment Scale-Cognitive Subscale, the primary outcome measure.

Pancortin-2 interacts with WAVE1 and Bcl-xL in a mitochondria-associated protein complex that mediates ischemic neuronal death

The actin-modulating protein Wiskott-Aldrich syndrome protein verprolin homologous-1 (WAVE1) and a novel CNS-specific protein, pancortin, are highly enriched in adult cerebral cortex, but their functions are unknown. Here we show that WAVE1 and pancortin-2 interact in a novel cell death cascade in adult, but not embryonic, cerebral cortical neurons. Focal ischemic stroke induces the formation of a protein complex that includes pancortin-2, WAVE1, and the anti-apoptotic protein Bcl-xL. The three-protein complex is associated with mitochondria resulting in increased association of Bax with mitochondria, cytochrome c release, and neuronal apoptosis. In pancortin null mice generated using a Cre-loxP system, ischemia-induced WAVE1-Bcl-xL interaction is diminished, and cortical neurons in these mice are protected against ischemic injury. Thus, pancortin-2 is a mediator of ischemia-induced apoptosis of neurons in the adult cerebral cortex and functions in a novel mitochondrial/actin-associated protein complex that sequesters Bcl-xL.

Phospho-dependent functional modulation of GABA(B) receptors by the metabolic sensor AMP-dependent protein kinase

GABA(B) receptors are heterodimeric G protein-coupled receptors composed of R1 and R2 subunits that mediate slow synaptic inhibition in the brain by activating inwardly rectifying K(+) channels (GIRKs) and inhibiting Ca(2+) channels. We demonstrate here that GABA(B) receptors are intimately associated with 5'AMP-dependent protein kinase (AMPK). AMPK acts as a metabolic sensor that is potently activated by increases in 5'AMP concentration that are caused by enhanced metabolic activity, anoxia, or ischemia. AMPK binds the R1 subunit and directly phosphorylates S783 in the R2 subunit to enhance GABA(B) receptor activation of GIRKs. Phosphorylation of S783 is evident in many brain regions, and is increased dramatically after ischemic injury. Finally, we also reveal that S783 plays a critical role in enhancing neuronal survival after ischemia. Together our results provide evidence of a neuroprotective mechanism, which, under conditions of metabolic stress or after ischemia, increases GABA(B) receptor function to reduce excitotoxicity and thereby promotes neuronal survival.

255 EFFECT OF THE TYPE OF DIETARY FATTY ACID (α-LINOLENIC ACID OR LINOLEIC ACID) ON THE NUMBER AND THE QUALITY OF OOCYTES COLLECTED BY OVUM PICKUP AND ON IN VITRO EMBRYO PRODUCTION BY DAIRY HEIFERS

A supplement of dietary fat can improve oocyte quality in ruminants. However, to our knowledge, the effect of the type dietary fat (differing in fatty acid profile) on oocyte and embryo production has never been reported in cattle. Therefore, in this study the effect of the type of fat supplement on the number and quality of oocytes collected by ovum pickup (OPU) and on the production of embryos was investigated in Holstein heifers. The experiment was conducted over 2 years: year 1: 8 heifers, and year 2: 10 heifers (16 to 20 months old, body weight 368 � 8.2 kg and BCS 2.3 � 0.1). Heifers were given a diet of hay (67% DM) and a concentrate (33% DM). The concentrate (130 g fat/kg DM) was formulated with either extruded linseeds (L, rich in α-linolenic acid (ω-3 fatty acid),n = 9) or extruded soybeans (S, rich in linoleic acid (ω-6 fatty acid), n = 9). Oocytes were collected by OPU for 6 weeks (2 sessions/week) and their morphological quality was assessed (Q1, excellent; Q2, good; Q3, fair; and Q4, low). The oocytes from one session/week were frozen and those from the other session were used to produce embryos (in vitro maturation and fertilization). Embryo quality was judged following IETS criteria (EQ1, excellent; EQ2, good; EQ3, fair; and EQ4, low). Blood samples were collected weekly throughout the experiment for the analysis of insulin, insulin-like growth factor-1, glucose, non-esterified fatty acids, β-hydroxybutyrate, and urea. Statistical analysis was performed on the growth rate, BCS, hormone, metabolite, and fatty acid data and on the oocyte and embryo data using Split plot ANOVA. Growth rate was not affected by diet (S, 0.93 � 0.21 kg d-1 vs. L, 0.90 � 0.21 kg d-1), and there was no effect of dietary treatment on plasma hormone and metabolite concentrations. However, treatment L increased the proportion of α-linolenic acid (P &lt; 0.0001), and treatment S increased the proportion of linoleic acid (P &lt; 0.0001) in the plasma. Neither the oocyte characteristics (number of oocytes collected, 5.3 � 1.0 vs. 5.7 � 1.0; their quality: Q1, 1.1 � 0.3 vs. 1.0 � 0.3; Q2, 1.8 � 0.3 vs. 1.6 � 0.3; Q3, 1.4 � 0.4 vs. 2.1 � 0.4; and Q4, 1.0 � 0.2 vs. 1.1 � 0.2; and oocytes inseminated, 4.4 � 0.8 vs. 5.1 � 0.8, and cleaved, 3.4 � 0.7 vs. 3.5 � 0.7 per heifer per session; L vs. S, respectively) nor the embryo characteristics (number of embryos, 1.1 � 0.3 vs. 0.9 � 0.3; their quality: EQ1, 0.4 � 0.1 vs. 0.3 � 0.1; EQ2, 0.4 � 0.1 vs. 0.3 � 0.1; EQ3, 0.2 � 0.1 vs. 0.3 � 0.1; and EQ4, 0.04 � 0.03 vs. 0.05 � 0.03 per heifer per session; L vs. S, respectively) were affected by dietary treatment. In conclusion, under our experimental conditions, the type of fatty acid (ω-3 vs. ω-6) does not modify significantly the numbers of oocytes and embryos produced by OPU and their quality in dairy eifers.

Effects of a gamma-secretase inhibitor in a randomized study of patients with Alzheimer disease

LY450139 dihydrate, a gamma-secretase inhibitor, was studied in a randomized, controlled trial of 70 patients with Alzheimer disease. Subjects were given 30 mg for 1 week followed by 40 mg for 5 weeks. Treatment was well tolerated. Abeta(1-40) in plasma decreased by 38.2%; in CSF, Abeta(1-40) decreased by 4.42 +/- 9.55% (p = not significant). Higher drug doses may result in additional decreases in plasma Abeta concentrations and a measurable decrease in CSF Abeta.

Duloxetine pharmacokinetics in cirrhotics compared with healthy subjects

OBJECTIVE

To compare the pharmacokinetics of single-dose duloxetine in cirrhotic and healthy subjects.

METHODS

An open-label inpatient study compared duloxetine pharmacokinetics in six subjects with moderate liver cirrhosis (Child-Pugh class B) to those in six healthy subjects. Subjects received a single 20 mg capsule of duloxetine following overnight fasting. Blood samples were collected up to 120 h post dose for determination of plasma concentrations of duloxetine and its major metabolites using a validated LC/MS/MS method. Plasma concentration-time data for duloxetine and its major metabolites were analyzed by noncompartmental methods. Specific pharmacokinetic parameters were assessed statistically using a mixed-effects model.

RESULTS

Duloxetine apparent clearance was significantly lower (24 vs 160 l/h, p < 0.05) and AUC values were substantially higher (775 vs 268 ng x (h/ml) in cirrhotic compared to healthy subjects. The half-life of duloxetine was about three times longer (47.8 vs 13.5 h) in cirrhotic than in healthy subjects (p < 0.05). In contrast, there was no significant difference in Cmax or apparent volume of distribution between the two groups. The metabolites exhibited lower levels and longer half-lives in cirrhotic subjects compared to healthy subjects. The lower clearance and slower elimination of duloxetine in cirrhotic individuals is likely attributable to impaired duloxetine metabolism.

CONCLUSIONS

The rate of duloxetine elimination is reduced for cirrhotic subjects, making dosage adjustments appropriate. Based on simulations, the duloxetine dose for at least an initial treatment period may need to be reduced and/or less frequently administered for patients with moderate cirrhosis.

Expression of NALP1 in cerebellar granule neurons stimulates apoptosis

NAcht Leucine-rich-repeat Protein 1 (NALP1) contains a putative nucleotide binding site, a region of leucine-rich repeats, and death domain folds at both termini providing protein/protein association functions such as caspase recruitment. We report here that NALP1 gene expression was induced in primary cerebellar granule neurons (CGN) upon injury. Up-regulation of NALP1 was also observed in a model of transient focal ischemia induced by middle cerebral artery occlusion. We investigated the biological consequence of over-expression of NALP1 in both HeLa cells and in CGN. Expression of recombinant NALP1 stimulated cell death in both HeLa cells and CGN by an apoptotic mechanism, demonstrated by the induction of apoptotic nuclear morphology and activation of the apoptotic enzyme caspase-3. Also described here are studies on the mechanism of action studies including deletion analyses and investigations of nucleotide binding, which begin to elucidate a regulatory function for NALP1 in neuronal apoptosis.

Estimating dose equivalence for new routes of drug administration

For patient's convenience, dose administration of insulin via oral inhalation is often considered as an alternative to subcutaneous administration. An important statistical problem is to estimate dose equivalence, which is the amount of drug needed to be delivered by inhalation to generate an equivalent pharmacokinetic (PK) response produced by a therapeutic dose of subcutaneous insulin. Because of high intersubject variability, a crossover design clinical trial is typically used where data from both routes of administration are obtained from the same subject. A linear mixed effects model is proposed to describe the relationship between AK response and insulin dose for the two routes of administration. Estimation of dose equivalence in this setting has not been discussed in the statistical literature. Several competing methods for estimating dose equivalence are proposed and contrasted. A formula for calculating an approximate sample size necessary to estimate dose equivalence with a desired precision for the new route of administration is also provided.

Inhaled micronized crystalline human insulin using a dry powder inhaler: dose-response and time-action profiles

AIM

The aim of this euglycaemic glucose clamp study was to investigate the pharmacokinetics, glucodynamics, safety and tolerability of micronized crystalline human insulin inhalation powder delivered by a Spiros dry powder inhaler system in healthy volunteers.

METHODS

Thirteen healthy, non-smoking, male and female volunteers [age 30 +/- 7 years; BMI 23.5 +/- 2.7 kg/m(2); (mean +/- sd)] with normal pulmonary function participated in an open-label, randomised, 6-period crossover trial. Each volunteer received four single doses of inhaled insulin (60, 90, 120, 150 U) on separate occasions. For comparison, each volunteer also received two of three possible doses of subcutaneous (s.c.) injected regular human insulin (8, 14, or 20 U).

RESULTS

Serum immunoreactive insulin following inhalation of insulin peaked an average of 60 min earlier compared with s.c. injected insulin (P < 0.0001). Following inhalation, the time to maximum glucose infusion rate occurred an average of 70 min earlier than with s.c. insulin: 187, 129, 161 and 162 min vs. 227, 241 and 241 min (P < 0.0001). The dose-response relationships for serum insulin pharmacokinetics and glucodynamics were linear for both inhaled and s.c. insulin. Relative bioavailability (based on serum insulin levels) ranged from 11.5 to 12.2% for the four doses of inhaled insulin and relative biopotency (based on glucose infusion rates) was 10.0 to 16.5%, respectively. Dosing was well tolerated by all volunteers.

CONCLUSION

This study demonstrates that inhalation of human insulin via a dry powder inhaler system provides a promising alternative route for administration of insulin.

Temporal assessment of caspase activation in experimental models of focal and global ischemia

Rodent models of focal and global ischemia were used to examine caspase activation. Several readouts were employed on identical tissue to provide correlative measurement of caspase induction, activation and enzymatic activity. In a rat focal ischemia model, caspase-3 enzymatic activity, as recorded by DEVD-AMC cleavage, peaked in penumbral cortex at 6-12 h following ischemia, correlating with increases in caspase 3-cleaved substrates of PARP and alpha-spectrin and subsequent disappearance of caspase-3 zymogen. Although induction of caspases 8 and 2 proteins was detectable as early as 6 h following ischemia, examination of the same tissues for caspase 8 or 2 enzymatic activities did not show significant modulation up to 12 h after ischemic insult. Caspase 9 induction was evident only after 24 h postischemia and did not correlate with elevated LDHD-AMC cleavage. Following global ischemia in gerbils, levels of caspase-3 enzyme activity peaked at 12 h in hippocampal tissue extracts. Cleaved caspase-3 signal was prominent in NeuN-positive layers in the CA1 region 6-12 h following ischemia. Interestingly, strong caspase-3 immunoreactivity was also detected in the subgranular zone of the dentate gyrus, a known region of ischemia-induced neurogenesis. Caspase-3 activation may be responsible for the loss of these cells, thereby hindering the endogenous recovery process.

Characterization of the WAVE1 knock-out mouse: implications for CNS development

Developing neurons must respond to a wide range of extracellular signals during the process of brain morphogenesis. One mechanism through which immature neurons respond to such signals is by altering cellular actin dynamics. A recently discovered link between extracellular signaling events and the actin cytoskeleton is the WASP/WAVE (Wiscott-Aldrich Syndrome protein/WASP-family verprolin-homologous protein) family of proteins. Through a direct interaction with the Arp2/3 (actin-related protein) complex, this family functions to regulate the actin cytoskeleton by mediating signals from cdc42 as well as other small GTPases. To evaluate the role of WASP/WAVE proteins in the process of neuronal morphogenesis, we used a retroviral gene trap to generate a line of mice bearing a disruption in the WAVE1 gene. Using a heterologous reporter gene, we found that WAVE1 expression becomes increasingly restricted to the CNS over the course of development. Homozygous disruption of the WAVE1 gene results in postnatal lethality. In addition, these animals have severe limb weakness, a resting tremor, and notable neuroanatomical malformations without overt histopathology of peripheral organs. We did not detect any alterations in neuronal morphology in vivo or the ability of embryonic neurons to form processes in vitro. Our data indicate that WAVE1, although important for the general development of the CNS, is not essential for the formation and extension of neuritic processes.

Lepidium meyenii (Maca) improved semen parameters in adult men

AIM

The present study was designed to determine the effect of a 4-month oral treatment with tablets of Lepidium meyenii (Maca) on seminal analysis in nine adult normal men aged 24-44 years old.

METHODS

Nine men received tablets of Maca (1500 or 3000 mg/day) for 4 months. Seminal analysis was performed according to guidelines of the World Health Organization (WHO). Serum luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL), testosterone (T) and estradiol (E2) were measured before and after treatment.

RESULTS

Treatment with Maca resulted in increased seminal volume, sperm count per ejaculum, motile sperm count, and sperm motility. Serum hormone levels were not modified with Maca treatment. Increase of sperm count was not related to dose of Maca.

CONCLUSION

Maca improved sperm production and sperm motility by mechanisms not related to LH, FSH, PRL, T and E2.

Education and training in hyperbaric medicine. The Icelandic experience. An example of international scientific cooperation

The authors describe their experience in the practice, education and learning in the field of hyperbaric medicine, following a project of international scientific cooperation, first in history, between Italy and Iceland. As a result of this project, the first hyperbaric facility came into use in Iceland in March 1993, initially entirely run and economically supported by the Italian side. Since 1997 the activity has been entirely financed by Icelandic National Health System with a special budget established each year according to an agreement between Icelandic and Italian Health Authorities, leaving the medical and the economical management of the Service to Italian personnel. Hyperbaric medicine is now a reality in the Icelandic medical practice. Moreover, since 1994 young Italian doctors from the University of Trieste, Italy, enrolled in the School of Specialization in Anesthesia, Intensive Care, have received training at the Service of Hyperbaric Medicine of the University of Reykjavik City Hospital, as part of their training. The educational activity, endorsed by the Italian Ministry of University and Research, consists of a theoretical part and of a practical part of operational assistance. At the end of his or her training, the resident has a full knowledge of the indications for hyperbaric oxygen therapy (HBOT) and of the related diagnostic and therapeutic procedures, is autonomous and is able to safely operate an hyperbaric chamber. An analytical report of the activity in year 2000 is also included.

Altitude decompression sickness. Case presentation

The in-flight altitude-related decompression sickness (DCS) is not as common as DCS occurring after working or recreational diving, or, at least, it is not commonly described in the medical literature. Though modern aircraft are safer and more reliable, occupants are still subject to the stress of high altitude flight, and altitude DCS still represents a risk to the occupants, mostly if they are exposed to altitudes of 25,000 ft or higher. The authors report their experience about two different accidents involving a US Air Force pilot and a navigator, treated at the Service of Hyperbaric Medicine at Landspitallin Fossvogur, the University of Reykjavik City Hospital, Iceland, because of occurrence of type II altitude-related DCS. A US Navy Oxygen Treatment Table 6 was successfully applied in both cases. Also considered are some aspects related to physiopathology, clinical presentation and therapy of DCS, with particular regard to the occurrence of DCS during flight.

HBO and gas gangrene. A case report

A 58-year old man, in a mediocre health condition, was admitted into Landspitallin Fossvogur, the University of Reykjavik City Hospital, Iceland, because of fever, chills, local pain and swelling due to the presence of a big old wound in his left heel. The first clinical appearance showed a gas gangrene of the area. The patient immediately underwent a surgical debridement and a fasciotomy, and antibiotic intravenous therapy and hyperbaric oxygen therapy (HBOT) were started. During the treatment the patient suffered for a multi-organ failure syndrome (MOFS), was admitted in ICU and survived. A total of 52 HBO sessions were performed and one month since the admission into the hospital the patient received a skin transplant. He achieved a complete restitutio ad integrum after 78 days of hospitalization. Gas gangrene is a fulminating infection caused by the genus of Clostridia. If not treated, it leads to the death of the host. The actual treatment for gas gangrene includes surgery, antibiotics, general resuscitative measures and HBOT.

Effect of Lepidium meyenii (maca) roots on spermatogenesis of male rats

AIM

To determine the effect of oral administration of an aqueous extract from the roots of Lepidium meyenii (maca) on spermatogenesis in adult male rats.

METHODS

Male rats received an aqueous extract of the root (66.7 mg in one mL) twice a day for 14 consecutive days.

RESULTS

Treatment with Lepidium meyenii resulted in an increase in the weights of testis and epididymis but not the seminal vesicle weight. The length and frequency of stages IX-XIV seminiferous tubules, where mitosis occurred, were increased and stages I-VI were reduced in rats treated with Lepidium meyenii.

CONCLUSION

The Lepidium meyenii root invigorates spermatogenesis in male rats by acting on its initial stages (IX-XIV).