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International audience; Safe and effective vaccines against coronavirus disease 2019 (COVID-19) are essential for ending the ongoing pandemic. Although impressive progress has been made with several COVID-19 vaccines already approved, it is clear that those developed so far cannot meet the global vaccine demand alone. We describe a COVID-19 vaccine based on a replication-defective gorilla adenovirus expressing the stabilized prefusion severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein named GRAd-COV2. We assessed the safety and immunogenicity of a single-dose regimen of this vaccine in healthy younger and older adults to select the appropriate dose for each age group. For this purpose, a phase 1, dose-escalation, open-labeled trial was conducted including 90 healthy participants (45 aged 18 to 55 years old and 45 aged 65 to 85 years old) who received a single intramuscular administration of GRAd-COV2 at three escalating doses. Local and systemic adverse reactions were mostly mild or moderate and of short duration, and no serious adverse events were reported. Four weeks after vaccination, seroconversion to spike protein and receptor binding domain was achieved in 43 of 44 young volunteers and in 45 of 45 older participants. Consistently, neutralizing antibodies were detected in 42 of 44 younger-age and 45 of 45 older-age volunteers. In addition, GRAd-COV2 induced a robust and T helper 1 cell (T H 1)-skewed T cell response against the spike protein in 89 of 90 participants from both age groups. Overall, the safety and immunogenicity data from the phase 1 trial support the further development of this vaccine.

Recent findings indicate that in cancer, host immune suppression and resistance to therapy is orchestrated by the presence and activity of stromal cells in the tumor microenvironment. Therefore novel approaches to overcome stromal mediated resistance to therapy represent a potential strategy to improve the outcome to chemotherapy and immune checkpoint blockade, particularly in tumors that have a fibrotic microenviroment. Autotaxin is an enzyme that converts Lysophosphatidylcholine (LPC) to Lysophosphatidic Acid (LPA), a key pathway that is aberrantly activated in fibrosis. LPA has also been described to act directly on tumor cells, promoting their growth and proliferation via G protein-coupled LPA Receptors (LPARs). IOA-289 is a novel, potent, selective and orally bioavailable inhibitor of Autotaxin, a target with known clinical application in fibrotic diseases and with a strong rationale for exploration in cancer. In preclinical models, IOA-289 modulated levels of circulating LPA in a dose dependent manner. At doses achieving at least 50% reduction of circulating LPA, IOA-289 showed monotherapeutic efficacy in in vivo mouse models of cancer. Notably the effects were most prominent in orthotopic models that recapitulate the stromal components of the microenvironment. In vitro studies investigated the mechanism of action of IOA-289, and it was shown to be driven by: (i)Direct anti-tumor activity on cancer cell lines in vitro (ii)Modulation of the secretory profile of fibroblasts(iii)Increased T cell infiltration in vitro and in vivo In a healthy volunteer study following a single oral ascending dose, IOA-289 showed a dose dependent increase in plasma and a corresponding decrease in circulating LPA. We also demonstrated that ATX was elevated in plasma from pancreatic cancer patients compared to samples from healthy volunteers and are correlated with soluble CA19-9. Based on our preclinical data we postulate that inhibition of the ATX/LPA pathway with IOA-289 may be a beneficial therapeutic strategy for cancer patients with fibrotic tumor microenvironments. The predicted biologically effective dose of IOA-289 has been calculated using PK/PD modelling combining data from preclinical studies and from the phase Ia healthy volunteer study. IOA-289 is scheduled to enter a phase Ib clinical trial in pancreatic cancer. Citation Format: Zoe Johnson, Marcel Deken, Ragini Medhi, Lauren Maggs, Alan Carruthers, Anne Cheasty, Alessia Tagliavini, Andrea Nizzardo, Marco Pergher, Karolina Niewola, Amy Fraser, Lars van der Veen, Pritom Shah, Luigi ZIviani, Stefano Milleri, Michael Lahn. Targeting Autotaxin to suppress stromal signaling in the tumor microenvironment to improve outcome to therapy in fibrotic tumor types [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2636.

Background Premature ejaculation (PE) is a common male neurobiological sexual disorder, related to a disturbance in central serotonin (5-hydroxytryptamine or 5-HT) neurotransmission. Aim To assess the efficacy of a single oral dose of 5HT1A receptor antagonist GSK958108 on ejaculation latency time (ELT) in male subjects suffering from PE. Methods A total of 35 male subjects were enrolled in a Phase 1 double-blind, placebo-controlled, parallel group masturbation-model study. All subjects completed the study. No subject was withdrawn from the study. There were no major protocol deviations reported during the study. Outcomes The primary outcome of the study was to evaluate the effect of a single oral dose of 5HT1A receptor antagonist GSK958108 on ELT as measured in the masturbation model; additionally, we investigated drug’s safety and tolerability. Results In the 3 mg GSK958108 treatment group, the ELT was estimated to be 16% longer (1.542 vs 1.328, 95% CI: -16% to +61%) than if the subjects had taken placebo. In the 7 mg GSK958108 treatment group, the ELT was estimated to be 77% longer (2.346 vs 1.328, 95% CI: +28% to +144%) than in the placebo group. The systemic exposure to GSK958108 increased with dosage between 3 mg and 7 mg. A significant trend toward an increase of ELT was observed with increasing plasma concentrations of GSK958108. A total of 4 patients all treated with 7 mg dose experienced minor drug related adverse events (5 adverse events in 4 patients): somnolence (n = 3), headache (n = 1), tinnitus (n = 1). Clinical Implications In the current double-blind, placebo-controlled parallel group study the 5HT1A receptor antagonist GSK958108 was tested in 3 mg and 7 mg doses for PE treatment in humans. It was shown that GSK958108 significantly delayed ejaculation showing a new and safe alternative in PE treatment. Strengths & Limitations The present study showed innovative results suggesting an important role of 5HT1A receptor antagonist in the PE treatment. However, the use of masturbation model and the small population are the main limitations of this investigation. Conclusion 5HT1A receptor antagonist GSK958108 3 mg per day and 7 mg per day was found to be well-tolerated, safe and effective for the treatment of PE subjects and demonstrated a strong association between 5HT1A receptors and ejaculation control in humans (NCT00861484). Migliorini F, Tafuri A, Bettica P, et al. A Double-Blind, Placebo-Controlled Parallel Group Study to Evaluate the Effect of a Single Oral Dose of 5-HT1A Antagonist GSK958108 on Ejaculation Latency Time in Male Patients Suffering From Premature Ejaculation. J Sex Med 2021;18:63–71.

INTRODUCTION AND OBJECTIVES:To assess the efficacy of a single oral dose of 5HT1A antagonist GSK958108 on ejaculation latency time (ELT) in male subjects suffering from premature ejaculation (PE).M...

Stress affects the immune system and intestinal microbiota composition and can lead to imbalance between pro- and anti-inflammatory cytokines or to uncontrolled production of cytokines. The effect of emotional stress on secretory IgA levels also indicates that stress decreases mucosal integrity. Our aim was to evaluate whether a probiotic product (Lactoflorene® Plus) can prevent alterations in the immune response associated with self-reported stress and microbiota composition. Healthy adult volunteers who self-reported psychological stress were enrolled and randomised into a placebo and a probiotic group. Salivary stress markers (α-amylase, cortisol, chromogranin A) and immunological parameters (sIgA, NK cell activity, IL-8, IL-10, TNF-α) in feces and the composition of intestinal microbiota were evaluated. Administration of the product did not exert a direct effect on the salivary stress markers or NK cell activity but did reduce abdominal pain and increase faecal IgA and IL-10 levels. The probiotic product induced a moderate increase in Bifidobacterium and Lactobacillus spp., as expected, and in Faecalibacterium spp., and decreased the size of the Dialister spp. and Escherichia and Shigella populations. Administration of the product helped protect the mucosal barrier by supporting the number of short-chain fatty acid producers and decreasing the load of potentially harmful bacteria, thus reducing intestinal inflammation and abdominal discomfort. ClinicalTrials.gov: NCT03234452. Keywords: BB-12®, LA-5®, Immune response, Stress, Abdominal pain, IgA

Stress affects the immune system and intestinal microbiota composition and can lead to imbalance between pro- and anti-inflammatory cytokines or to uncontrolled production of cytokines. The effect of emotional stress on secretory IgA levels also indicates that stress decreases mucosal integrity. Our aim was to evaluate whether a probiotic product (Lactoflorene® Plus) can prevent alterations in the immune response associated with self-reported stress and microbiota composition. Healthy adult volunteers who self-reported psychological stress were enrolled and randomised into a placebo and a probiotic group. Salivary stress markers (α-amylase, cortisol, chromogranin A) and immunological parameters (sIgA, NK cell activity, IL-8, IL-10, TNF-α) in feces and the composition of intestinal microbiota were evaluated. Administration of the product did not exert a direct effect on the salivary stress markers or NK cell activity but did reduce abdominal pain and increase faecal IgA and IL-10 levels. The probiotic product induced a moderate increase in Bifidobacterium and Lactobacillus spp., as expected, and in Faecalibacterium spp., and decreased the size of the Dialister spp. and Escherichia and Shigella populations. Administration of the product helped protect the mucosal barrier by supporting the number of short-chain fatty acid producers and decreasing the load of potentially harmful bacteria, thus reducing intestinal inflammation and abdominal discomfort. ClinicalTrials.gov NCT03234452.

The pharmacological properties of two NK1 antagonists were studied in comparison with a benzodiazepine during a 7% CO2 challenge in a population of healthy volunteers selected for a high sensitivity to the challenge. In total, 19 healthy subjects, pre-screened for their responsiveness to the 7% CO2 test, took part in the randomised, double-blind, cross-over, incomplete block design study. After receiving treatment or placebo, the volunteers were subjected to three 7% CO2 challenges each for a time of 20 min. The treatment consisted of the administration of the following three active drugs: a single dose of benzodiazepine alprazolam (0.75 mg) and a single dose of the NK1 antagonists vestipitant (GW597599) (15 mg) and vofopitant (GR205171) (25 mg). Anxiety during the challenge was evaluated with Visual Analogue Scale-Anxiety (VAS-A) and with Panic Symptom List (PSL III-R). Respiratory parameters, heart rate and skin conductance were also recorded. Compared with placebo, vestipitant showed a significant reduction ( p

Rationale. Research on the effects of nicotine abstinence and nicotine replacement has not provided consistent information about the impact of replacement therapies on tobacco withdrawal and craving. Objective. This study investigated craving and withdrawal symptoms over a 72-h period of abstinence from cigarettes. Methods. Twenty-four healthy volunteers, not intending to quit smoking, were housed in an experimental unit during three 72-h conditions, consisting of either free smoking, enforced smoking cessation with nicotine replacement therapy (NRT) patches, or enforced smoking cessation with placebo patches. The conditions were adhered to using a randomized crossover design, each separated by at least 10 days of washout. Patches, administered in a double-blind fashion, were given as nicotine (21 mg/24 h) and placebo every 24 h. Self-reported cigarette craving and withdrawal were assessed using multi-item scales at fixed intervals over each condition period. Urinary and plasma cortisol levels were also assayed at fixed intervals over each period. Results. Craving intensity was significantly lower with free smoke than with placebo and with NRT patches than with placebo. No difference in craving levels was found between those who smoked or those who had NRT patches. Withdrawal symptoms were significantly lower with free smoke than with either placebo or NRT patches, but there was no difference in levels of withdrawal between those on NRT patches and those on placebo. During the placebo and NRT patch periods, craving intensity displayed a circadian rhythm, with craving levels lowest in the morning and peaking in the evening. Nicotine delivered via the patch had no impact on these circadian variations in craving. There was no evidence of systematic temporal variations in craving levels during the free smoking period. Conclusions. The data suggested that craving and withdrawal symptoms may be sustained by different physiological pathways, and that only selected components of cigarette craving are influenced by NRT.

The neuroprotective activity of GV150526 (3-[2-(Phenylaminocarbonyl)ethenyl]-4,6-dichloroindole-2-carboxylic acid sodium salt), a selective glycine receptor antagonist of the NMDA receptor, has been evaluated by magnetic resonance imaging (MRI) in a rat model of middle cerebral artery occlusion. The aim of the work was to evaluate, using an in vivo method, whether GV150526 was able to reduce the extent of ischemic brain damage when administered both before and after (6 h) middle cerebral artery occlusion. GV150526 was administered at a dose of 3 mg/kg i.v. T2-weighted (T2W) and diffusion weighted (DW) images were acquired at 6, 24 and 144 h after the establishment of the cerebral ischemia. Substantial neuroprotection was demonstrated at all investigated time points when GV150526 was administered before the ischemic insult. The ischemic volume was reduced by 84% and 72%, compared to control values, when measured from T2W and DW images, acquired 24 h after middle cerebral artery occlusion. Administration of the same dose of GV150526, 6 h post-ischemia, also resulted in a significant (p

The neuroprotective activity of the novel, selective glycine antagonist GV150526 was assessed in the middle artery occlusion (MCAo) model of focal ischemia. Postischemia administration of GV150526 (3 mg/kg i.v.) up to 6 h post-MCAo resulted in a significant reduction of the infarct volume measured histologically 24 h later. The neuronal protection by GV150526 was accompanied by functionally significant protection determined by somatosensory evoked potential (SEP) responses recorded from the primary somatosensory cortex of rats under urethane anesthesia. Experimental occlusion of the MCA 7 days prior to electrophysiological testing induced a clear reduction in the SEP amplitude. GV150526 (3mg/kg, i.v.) was able to protect SEP responses recorded from the hindpaw cortical field in two groups of animals treated either 1 (n = 9) or 6 h (n = 10) post-MCAo. SEP responses recorded from the forepaw cortical field, an area closer to the core of the ischemic damage, were significantly protected only in the group treated 1 h post-MCAo. Histological evaluation of the rat brain regions showed a correlated decrease in the ischemic area of GV150526-treated groups. The volumes of the ischemic brains of both GV150526 groups were statistically different from the MCAo group (P < 0.05). These findings demonstrate that GV150526 is able to prevent the ischemic damage assessed histologically and affect the functional correlates of the ischemia evaluated by the electrophysiological SEP measurements.

Induction of NADPH-diaphorase (NDP) following ischemic infarction was studied by means of histochemistry in the rat cerebral cortex 1, 2, 7, and 14 days after distal occlusion of the right middle cerebral artery (MCA). The fine structure of cells in the penumbra region of the necrotic center was also investigated. MCA distal occlusion resulted in ischemic lesion of the frontoparietal cortex of variable extent; NDP induction was detected in neurons, astrocytes, macrophages, and endothelial cells, with a regional specificity and a temporal gradient. One, two, and seven days after MCA occlusion, weak NDP positivity was consistently induced in some pyramidal neurons in cortical areas neighboring the necrotic area; NDP induction was also seen in pyramidal neurons of the ipsilateral anterior cingulate and infralimbic cortices and in the tenia tecta. In addition, numerous NDP-positive pyramidal neurons were detected in the contralateral frontoparietal cortex after relatively large ischemic lesions. Two weeks after MCA occlusion, NDP induction in neurons was only evident in the deep cortical layers near the lesion. NDP histochemistry combined with glial fibrillary acidic protein immunofluorescence, performed 7 days after MCA occlusion, indicated that the astrocytes at the periphery of the necrotic area were hypertrophic and some of them were also NDP-positive. One and two days after MCA occlusion, numerous macrophages displaying NDP positivity of variable intensity were seen at the periphery of the necrotic area and in the external capsule of the ischemic cerebral hemisphere. Many endothelial cells in the cortex and subcortical white matter were consistently NDP-positive in all rats. Electron microscopic study indicated that the area adjacent to the necrotic center was composed of fibrous astrocytes, with the morphological characteristics of proliferation, and numerous lysosome-filled macrophages. Altogether the present results suggest that focal cerebral ischemia may induce in different cell types nitric oxide synthase, which is equivalent to NDP in fixed tissue. The induction of nitric oxide synthase may be related to (1) blood-flow regulation at relatively early postischemic stages, which may decline when collateral circulation is established, and/or (2) cytotoxic or neuroprotective mechanisms.

The asymmetric synthesis of both enantiomers of the racemic NMDA antagonist eliprodil was accomplished in a novel application of Sharpless' asymmetric dihydroxylation (AD) methodology. A difference in neuroprotective activity was noted for the enantiomers in an in vivo model of rat focal cerebral ischemia.

To evaluate the postoperative analgesic efficacy of GW842166, a noncannabinoid CB2 agonist, in patients undergoing third molar tooth extraction.This randomized, double-blind, placebo-controlled study compared the analgesic efficacy of single doses of GW842166 (100 or 800 mg) or ibuprofen with placebo in patients undergoing extraction of at least 1 fully or partially impacted third molar tooth. Eligible participants were dosed preoperatively within 1 hour of surgery. Participants allocated to active comparator received a second dose of ibuprofen (400 mg), 4 hours after the first 800 mg dose. Participants in the GW842166 and placebo groups received placebo at 4 hours. Procedures for the assessment of efficacy included a visual analog scale and verbal rating scale for scoring pain up to 10 hours postsurgery, duration of analgesia, patient global evaluation, proportion of patients requiring rescue medication, and elapsed time to rescue analgesia. Analysis of covariance was used to compare efficacy variables. Patient global evaluation was analyzed using Wilcoxon rank-sum tests and time to data was analyzed using the log-rank test.Ibuprofen was significantly more effective than placebo across all endpoints. Trends for an improvement in pain scores for GW842166 800 mg failed to be of either clinical or statistical significance. GW842166 100 mg showed little separation from placebo. There was no evidence for any beneficial adjunctive effect after coadministration of rescue analgesia with GW842166. All treatments were well tolerated.In comparison to ibuprofen, single doses of GW842166 (100 and 800 mg) failed to demonstrate clinically meaningful analgesia in the setting of acute dental pain.

Sustained-release (SR) bupropion enhances quit rates of smokers, generally decreases tobacco withdrawal, and in some studies, reduces craving. Investigate the effects of SR bupropion on craving and withdrawal during cigarette abstinence. Twenty three smokers participated in three 17-day periods composed of 14 out-patient days followed by 3 (72 h) in-patient days. During the out-patient days, subjects received SR bupropion, placebo, or no drug. During the in-patient days, subjects were abstinent from cigarettes on two occasions while receiving either SR bupropion or placebo and smoked freely during the other occasion. SR bupropion was titrated over the first three out-patient days followed by a fixed dose (300 mg/day) for 14 days (including the three in-patient abstinence days). Cigarette craving, withdrawal, and selected physiological measures were assessed repeatedly over the 72-h periods. During the 72-h periods, craving intensity was significantly lower with free smoke and SR bupropion than with placebo, and significantly lower during free smoke than during SR bupropion. Overall withdrawal symptoms were significantly lower with free smoke than with either placebo or SR bupropion. Among individual withdrawal symptoms (excluding craving), appetite increase was significantly reduced during SR bupropion compared to placebo. During placebo and SR bupropion, craving intensity displayed a circadian pattern that was different from that observed during free smoke. SR bupropion reduced craving and appetite increase during smoking abstinence. These findings support the hypothesis that craving and withdrawal symptoms may be controlled by distinct central nervous system pathways.

We investigated resting EEG and auditory P300 during free smoking and 36 h of enforced smoking abstinence in 12 healthy volunteers. Resting EEG was recorded on 19 scalp leads and auditory P300 was obtained by an oddball paradigm task. Spectral analysis of EEG (absolute and relative power, mean frequency), latency and amplitude of auditory P300 were considered for statistical analysis. EEG changes were not significant during free smoking but were significant during smoking abstinence. Theta absolute power increased by +57% (P

To investigate the potential for systemic pharmacodynamic and pharmacokinetic interactions between inhaled salmeterol and fluticasone propionate when repeat doses of the two drugs are given in combination to healthy subjects.Twenty-eight healthy subjects received salmeterol 100 microg, salmeterol 100 microg/fluticasone propionate 500 microg and fluticasone propionate 500 microg via a Diskus dry powder inhaler twice daily for 11 days according to a randomised, double-blind, placebo-controlled, crossover design. Subjects in the placebo group also received a single dose of salmeterol 100 microg on the morning of day 10. On day 10, the systemic effects of salmeterol [on pulse rate, blood pressure, corrected QT (QTc) interval and serum potassium and glucose levels] and fluticasone propionate (on 24-h urinary cortisol and morning plasma cortisol levels) were assessed. Maximal number and affinity of lymphocyte beta2-adrenoceptors and beta2-adrenoceptor polymorphism at loci 16 and 27 were also determined. Plasma pharmacokinetics of salmeterol and fluticasone propionate were determined after the morning dose on day 10. Dosing continued on the evening of day 10 and on day 11, and on day 12 the effect of repeat-dose treatment with salmeterol and salmeterol/fluticasone propionate on the systemic effects of cumulative doses of inhaled salbutamol (up to a total dosage of 3,200 microg) was evaluated.All treatments were safe and well tolerated. With the exception of a higher pulse rate after repeat administration of salmeterol [66.2 beats per minute (bpm) versus 63.6 bpm], there were no significant differences between the single-dose and repeat-dose salmeterol groups. The systemic pharmacodynamic effects of inhaled salmeterol were not affected by the co-administration of fluticasone propionate. Eleven days of treatment with salmeterol induced tachyphylaxis to the systemic effects of cumulative doses of salbutamol; however, co-administration of fluticasone propionate did not affect the response to salbutamol. Fluticasone propionate reduced 24-h urinary cortisol excretion (22.4 microg compared with 48.6 microg with placebo), but this was unaffected by the co-administration of salmeterol. Morning plasma cortisol levels were not reduced compared with placebo. There was no significant treatment effect on lymphocyte beta2-adrenoceptors and no correlation of beta2-adrenoceptor polymorphism at loci 16 and 27 with the development of tachyphylaxis. Salmeterol plasma concentrations were measurable only during the first half-hour after dosing. Co-administration of fluticasone propionate did not affect the peak plasma concentration (Cmax) of salmeterol. For fluticasone propionate, there were no statistically significant differences between salmeterol/fluticasone propionate and fluticasone propionate with respect to Cmax, plasma concentration at the end of the dosing interval (Ct), terminal elimination half-life (t1/2) or time to Cmax (tmax). The area under the concentration-time curve within a dosing interval (AUCt) for fluticasone propionate after inhalation of salmeterol/fluticasone propionate was statistically significantly higher (about 8%) than after inhalation of fluticasone propionate alone (P=0.0135). However, the 90% confidence intervals (CIs) for the AUCt and Cmax ratios for the two treatments were within the accepted limits for bioequivalence (1.03, 1.13 and 0.97, 1.12, respectively).These results in healthy subjects indicate that there is no systemic pharmacodynamic or pharmacokinetic interaction between inhaled salmeterol and fluticasone propionate when given in combination.

Lacidipine, a long acting 2, 4-dihydropyridine calcium channel antagonist is frequently administered with cholesterol lowering agents, particularly in elderly populations. The effects of lacidipine on the pharmacokinetics of simvastatin were investigated, since they share the CYP3A4 pathway for metabolism.The study was an open, randomised, two-way crossover design, with at least 7 days washout. Eighteen healthy subjects received simvastatin, 40 mg once daily, alone and together with lacidipine, 4 mg once daily, for 8 days. The pharmacokinetics of simvastatin were studied on the eighth day. Analysis was made of total simvastatin acid concentrations (naive simvastatin acid plus that derived from alkaline hydrolysis of the lactone).Lacidipine increased the maximum concentration of simvastatin (Cmax) by approximately 70% (P=0.016) and the area under the plasma concentration-time curve AUC(0,24 h) by approximately 35% (P=0.001). The mean Cmax and AUC(0,24 h) of simvastatin (95% confidence interval) when given alone were 8.76 (6.72-11.41) ng ml(-1) and 60.36 (47.15-77.28) ng ml(-1) h. During treatment with lacidipine they were, respectively, 14.89 (10.77-20.58) ng ml(-1) and 80.96 (64.62-101.44) ng ml(-1) h. No significant differences were observed in either time to peak concentration (tmax was 1.0 h for simvastatin alone and 1.5 h for the combination) or in the half-life (t1/2,z was 8.5 h in both cases). The combination was safe and well tolerated.The observed increased exposure to simvastatin 40 mg following coadministration of lacidipine is unlikely to be of clinical relevance.

In the rat, normal blood flow can be restored in the territory of the occluded artery after an arterial occlusion. This event has been attributed to changes in the collateral vessels supplying the territory of the occluded artery. Since only a limited amount of data is available about the plasticity of the microvascular system after a cortical ischemic lesion, in the present study we have evaluated whether the restoration of blood flow to normal levels in the territory of the middle cerebral artery after permanent ischemia is due only to flow through preexisting collateral vessels or also to the development of new microvessels. Middle cerebral artery occlusion was performed in 45 rats. After 24 h of ischemia, magnetic resonance imaging was used to select 16 rats with cortical lesions of similar size and location. After 2 weeks, vascular corrosion casts were obtained from 8 rats by injection of low-viscosity resin and observed by scanning electron microscopy. A correlative light and electron microscopy study was performed using the remaining 8 rats. Two different patterns of vascular modifications were found, one dorsal and one ventral to the lesion. The dorsal portion of the lesion was vascularized by collateral arteries originating from the anterior or posterior cerebral arteries. Collateral trunks showed a meandering course, mainly in the occipital pole. In the ventral portion of the lesion a complex microvascular system was found characterized by an intense vascular proliferation. The arterioles showed a parallel, candelabrum-like pattern with dichotomic branching. Contraction rings were frequently seen. The capillaries showed a sinusoid-like structure, with a large lumen and a continuous endothelium with many micropinocytotic vesicles. A peripheral ring-shaped venous sinus was composed of a network of flat vessels. These results give the first comprehensive description of the microvascular modifications in a focal model of infarct and suggest that the restoration of blood flow to normal levels described in the territory of the middle cerebral artery after permanent ischemia may be due not only to flow through collateral vessels but also to the development of a new vascular system originating mainly from branches of the middle cerebral artery before the occlusion point.

Fluticasone propionate pressurized metered dose inhalers (pMDIs) containing the hydrofluoroalkane (HFA) propellant, HFA 134a, are being developed to replace existing chlorofluorocarbon (CFC) pMDIs. This is part of the ongoing worldwide project to limit the damage to the earth's ozone layer. The in vivo performance and dose proportionality of fluticasone propionate HFA 134a pMDIs was examined for fluticasone propionate doses of 400, 1000 and 2000 μg using the 50, 125 and 250 μg strength pMDIs, respectively. The 125 and 250 μg strength HFA 134a pMDIs were compared with corresponding fluticasone propionate CFC pMDIs. Twenty-three healthy subjects participated in this single dose, randomized, five-way, cross-over study. Serial blood samples were collected 24 h post-dose to measure fluticasone propionate plasma concentrations. Twenty-four hour urinary-free cortisol was also measured before and after dosing. A dose-proportional increase in plasma fluticasone propionate concentrations was observed with increasing dose for the HFA 134a pMDIs. This was associated with a dose-related decrease in urinary cortisol excretion. Similar or lower fluticasone propionate systemic exposure was observed with the HFA 134a pMDIs compared to the corresponding CFC inhalers. The differences in systemic exposure observed for the HFA 134a and CFC pMDIs were too small to produce a differential effect on urinary cortisol excretion. Since fluticasone propionate has negligible oral bioavailability, the systemic exposure, which arises only from pulmonary absorption, is a measure of lung deposition. There was a good correlation between the in vitro fine particle mass produced by the different strengths and types of pMDI and the systemic exposure to fluticasone propionate. Therefore, the fluticasone propionate HFA 134a pMDI is an acceptable pharmaceutical alternative to the current CFC pMDI, producing similar lung deposition and no increase in systemic exposure at microgram equivalent doses.