Routine treatment pathways of patients with major depression and active suicidal ideation with intent in Italy: interim results from the ARIANNA observational study

Introduction

Major depressive disorder (MDD), especially in case of suicidal risk, is a psychiatric emergency, associated with high patient burden and healthcare resource utilization. Although active and urgent treatment is crucial, little is known on comprehensive care management of this condition in Italy.

Objectives

Here we report the ARIANNA study [NCT04463108] interim results to primarily describe the treatment utilization pathways of patients with MDD and active suicidal ideation with intent in the current clinical practice in Italy.

Methods

This observational prospective cohort study included adult patients with a moderate-to-severe major depressive episode (MDE) and active suicidality from 24 Italian sites. Real-world data on patient characteristics, treatments, clinical outcomes, and healthcare utilization were collected during a 90-day follow-up. Data collection is still ongoing.

Results

Sixty-four evaluable patients were considered for this interim analysis: 41 (64.1%) females, mean [SD] age 46.0 [15.4] years, a concomitant psychiatric diagnosis in 7 (10.9%), and other comorbidities in 26 (40.6%). The baseline mean [SD] MADRS total score was 37.5 [7.2], with severe MDE and prior suicidal behavior in 30 (46.9%) and 21 (32.8%) patients, respectively. Median [25th;75th percentiles] duration of current MDE was 1.1 [0.3;2.1] months. Acute inpatient hospitalization was provided for 43 (67.2%) patients. Antidepressant augmentation with mood stabilizers and/or antipsychotic drugs and optimization were the most frequent early standard-of-care treatment regimens in 32 (53.3%) and 24 (40.0%) patients with available data (N=60), respectively.

Conclusions

Our preliminary results suggest that initial treatment approaches in this critical population are mostly polypharmacological and delivered as inpatient care, with consequent intensive resource utilization.

Disclosure

The ARIANNA study was sponsored by Janssen-Cilag SpA, Italy. DD and MA are employees of Janssen-Cilag SpA. DA and BR are employees of MediNeos S.U.R.L., a company subject to the direction and coordination of IQVIA Solutions HQ Ltd.

Eosinophils adhesion assay as a tool for phenotypic drug screening - The pharmacology of 1,3,5 - Triazine and 1H-indole like derivatives against the human histamine H4 receptor

Histamine is a pleiotropic biogenic amine, having affinity towards four distinct histamine receptors. The existing pharmacological studies suggest the usefulness of histamine H₄ receptor ligands in the treatment of many inflammatory and immunomodulatory diseases, including allergic rhinitis, asthma, atopic dermatitis, colitis or pruritus. Up to date, several potent histamine H₄ receptor ligands were developed, none of which was registered as a drug yet. In this study, a series of potent indole-like and triazine derivatives were tested, in radioligand displacement and functional assays at histamine H₄ receptor, as well as in human eosinophils adhesion assay to endothelium. For selected compounds permeability, cytotoxicity, metabolic and in vivo studies were conducted. Adhesion assay differentiated the activity of different groups of compounds with a known affinity towards the histamine H₄ receptor. Most of the tested compounds downregulated the number of adherent cells. However, adhesion assay revealed additional properties of tested compounds that had not been detected in radioligand displacement and aequorin-based functional assays. Furthermore, for some tested compounds, these abnormal effects were confirmed during the in vivo studies. In conclusion, eosinophils adhesion assay uncovered pharmacological activity of histamine H₄ receptor ligands that has been later confirmed in vivo, underscoring the value of well-suited cell-based phenotypic screening approach in drug discovery.

Treatments for COVID-19: emerging drugs against the coronavirus

The Coronavirus disease 19 (COVID-19) outbreak has been recognized as a global threat to public health. It is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and no effective therapies currently exist against this novel viral agent. Along with extensive public health measures, an unprecedented global effort in identifying effective drugs for the treatment is being implemented. Potential drug targets are emerging as the result of a fast-evolving understanding of SARS-CoV-2 virology, host response to the infection, and clinical course of the disease. This brief review focuses on the latest and most promising pharmacological treatments against COVID-19 currently under investigation and discuss their potential use based on either documented efficacy in similar viral infections, or their activity against inflammatory syndromes. Ongoing clinical trials are also emphasized.

Weekend effects on health outcomes and operational efficiency in emergency admissions to general medicine services of the Central Hospital of the Autonomous Province of Bolzano, Italy

The possibility of higher death rates after admission to hospital during the weekend has been intensively investigated in North America and Northern Europe, while data are almost absent from Southern Europe and other WHOV regions. Increased death rates have not been uniformly confirmed. Differences in hospital care on weekends can vary depending on the reason for hospital admission, place and time. The aim was to verify whether weekend admission from the emergency department to internal medicine services is associated with parameters of operational efficiency in a Northern Italian hospital. A retrospective analysis was performed using hospital administration data of 3,594 admissions in 2016. A total of 287 patients (8.0%) had intensive care unit/IMCU transfers and 218 patients (6.1%) deceased in the hospital. Patients admitted on the weekend were similar to patients admitted during the week across age and gender, while weekend patients were more likely to be admitted on a "bad" day, defined as a day with a median number of admitted patients per day of >10 during the week and >9 on weekend. When adjusting for age and gender, patients admitted on weekend had significantly shorter length of stay compared to patients admitted during the week. In conclusion, emergency weekend admission to an internal medicine service was not associated with worse hospitalization-relevant outcomes in a regional hospital in Italy. Lower length-of-stay when emergency admission was on weekend is suggestive of lower disease severity of patients admitted to internal medicine services than on weekdays. If this represents higher risk of inappropriate hospital admission on weekends requires further study.

Role of histamine H4 receptors in the gastrointestinal tract

The location and functional role of histamine H4 receptors (H4Rs) in the gastrointestinal tract (GI) is reviewed, with particular reference to their involvement in the regulation of gastric acid secretion, gastric mucosal defense, intestinal motility and secretion, visceral sensitivity, inflammation, immunity and carcinogenesis. H4Rs have been detected in different cell types of the gut, including immune cells, paracrine cells, endocrine cells and neurons; moreover, H4R expression was reported in human colorectal cancer specimens. Functional studies with selective H4R ligands demonstrated protective effects in several experimental models of gastric mucosal damage and intestinal inflammation, suggesting a potential therapeutic role of drugs targeting this new receptor subtype in GI disorders, such as allergic enteropathy, inflammatory bowel disease (IBD), irritable bowel syndrome (IBS) and cancer.

Galantamine and behavior in Alzheimer disease: analysis of four trials

OBJECTIVES

Many individuals with Alzheimer's disease (AD) experience behavioral and neuropsychiatric symptoms, which may cause caregiver distress and lead to the institutionalization of the patient. This analysis characterized behavioral symptoms and caregiver distress in trials of galantamine and their response to treatment.

MATERIALS AND METHODS

Data were pooled from four randomized, placebo-controlled clinical trials of galantamine in patients with mild to moderate AD (three studies) or AD plus cerebrovascular disease (one study) (n = 2177). Behavior and associated caregiver distress were assessed in each study using the Neuropsychiatric Inventory (NPI) and NPI distress (NPI-D), respectively.

RESULTS

After 5/6 months, but not after 3 months, NPI score was significantly improved with galantamine vs placebo (P = 0.013). The benefit was particularly pronounced in patients categorized as having advanced moderate AD. At 5/6 months, there was a numerical benefit of galantamine over placebo in terms of caregiver distress; the difference was statistically significant in patients with moderate or advanced moderate AD.

CONCLUSIONS

Galantamine reduces behavioral symptoms in patients with mild to moderate AD, leading to reduced caregiver burden. The reductions were greatest in patients with moderate or advanced moderate disease.

Selective histamine H₃ and H₄ receptor agonists exert opposite effects against the gastric lesions induced by HCl in the rat stomach

The present study investigated the role of histamine H(3) and H(4) receptors in gastric mucosal defense, by the use of selective ligands. Firstly, the affinities of several histaminergic agonists for the rat histamine H(3) and H(4) receptors were checked in HEK 293T cells transfected with either receptor subtype. Next, functional activities were determined in conscious rat against the ulcerogenic effect of 0.6N HCl. Radioligand binding studies showed that immethridine and methimepip were the most selective agonists at rat H(3) receptors, whereas VUF10460 displayed approximately a 50-fold selectivity for the rat H(4) receptor over the H(3) receptor. In conscious rats, immethridine and methimepip significantly reduced (66% and 48% inhibition, respectively) the gastric lesions induced by HCl; the effect of immethridine was antagonized by the H(3) receptor antagonist A-331440, but not by the H(4) receptor antagonist JNJ7777120. The mixed H(3)/H(4) receptor agonist immepip induced a significant aggravation of HCl damage, which was prevented by JNJ7777120; HCl-induced lesions were also significantly enhanced by the H(4) receptor agonists VUF10460 and VUF8430; however, this effect was not modified by JNJ7777120. Overall, this study indicates that, whereas the histamine H(3) receptor is involved in the protection of rat stomach against concentrated HCl, the functional role of the H(4) receptor is still to be defined, although selective agonists induce proulcerogenic effects under HCl challenge. Finally, the species-dependent variations in affinity and receptor selectivity observed for most ligands need to be carefully addressed in the pharmacological characterization of histamine H(3) and H(4) receptor functions in vivo.

Measurement of gastric acid secretion in the anaesthetized rat

The protocols described in this unit are designed to assess the effects of substances on gastric acid secretion by the rat stomach, with the animal under general anesthesia. Both stimulatory and inhibitory effects of compounds can be evaluated and specific mechanisms of action can also be investigated. Acid secretion is induced by substances that directly activate parietal cell receptors (histamine and bethanechol), by indirect stimuli, like 2-deoxy-D-glucose, by electrical stimulation of vagal nerves, or by the peptide pentagastrin. Reference antisecretory drugs are represented by histamine H(2) receptor antagonists and proton pump inhibitors. This model allows the evaluation of complete dose-response curves together with a time-course of the secretory/antisecretory effects. Indirect effects involving activation or inhibition of vagal pathways are evaluated in intact animals by means of electrical vagal stimulation or in vagotomized animals.

Histamine H(3) receptors are involved in the protective effect of ghrelin against HCl-induced gastric damage in rats

In the present study, the effects of ghrelin against the gastric damage induced by intragastric administration of 0.6 N HCl and the involvement of histamine H₃ receptors (H₃Rs) were investigated in conscious rats with selective H₃R ligands. Intraperitoneal (i.p.) injection of ghrelin (40 μg/kg) significantly reduced (43%) the gastric lesions caused by concentrated acid. The effect of ghrelin was prevented by prior administration of the ghrelin receptor antagonist [D-Lys³]-GHRP-6 (100 μg/kg i.p.) and by subcutaneous (s.c.) injection of the nonimidazole H₃R antagonist UCL2138 (30 mg/kg). The selective H₃R agonist immethridine (30 mg/kg s.c.) significantly inhibited (64.60%) the gastric lesions induced by 0.6 N HCl. The effect of immethridine was prevented by prior administration of UCL2138 (30 mg/kg s.c.), but not by [D-Lys³]-GHRP-6 (100 μg/kg i.p.). Neither [D-Lys³]-GHRP-6 nor UCL2138 modified HCl-induced gastric damage per se. These data enlarge previous studies showing protective effects of ghrelin against ulcerogenic stimuli; in addition, they clearly indicate that ghrelin-induced gastroprotection involves the release of histamine, which enhances gastric mucosal defense through the activation of histamine H₃Rs.

Synthesis and QSAR of quinazoline sulfonamides as highly potent human histamine H4 receptor inverse agonists

Hit optimization of the class of quinazoline containing histamine H(4) receptor (H(4)R) ligands resulted in a sulfonamide substituted analogue with high affinity for the H(4)R. This moiety leads to improved physicochemical properties and is believed to probe a distinct H(4)R binding pocket that was previously identified using pharmacophore modeling. By introducing a variety of sulfonamide substituents, the H(4)R affinity was optimized. The interaction of the new ligands, in combination with a set of previously published quinazoline compounds, was described by a QSAR equation. Pharmacological studies revealed that the sulfonamide analogues have excellent H(4)R affinity and behave as inverse agonists at the human H(4)R. In vivo evaluation of the potent 2-(6-chloro-2-(4-methylpiperazin-1-yl)quinazoline-4-amino)-N-phenylethanesulfonamide (54) (pK(i) = 8.31 +/- 0.10) revealed it to have anti-inflammatory activity in an animal model of acute inflammation.

Pharmacological characterization of the new histamine H4 receptor agonist VUF 8430

BACKGROUND AND PURPOSE

We compare the pharmacological profiles of a new histamine H4 receptor agonist 2-(2-guanidinoethyl)isothiourea (VUF 8430) with that of a previously described H4 receptor agonist, 4-methylhistamine.

EXPERIMENTAL APPROACH

Radioligand binding and functional assays were performed using histamine H4 receptors expressed in mammalian cell lines. Compounds were also evaluated ex vivo in monocyte-derived dendritic cells endogenously expressing H4 receptors and in vivo in anaesthetized rats for gastric acid secretion activity.

KEY RESULTS

Both VUF 8430 and 4-methylhistamine were full agonists at human H4 receptors with lower affinity at rat and mouse H4 receptors. Both compounds induced chemotaxis of monocyte-derived dendritic cells. VUF 8430 also showed reasonable affinity and was a full agonist at the H3 receptor. Agmatine is a metabolite of arginine, structurally related to VUF 8430, and was a H4 receptor agonist with micromolar affinity. At histamine H3 receptors, agmatine was a full agonist, whereas 4-methylhistamine was an agonist only at high concentrations. Both VUF 8430 and agmatine were inactive at H1 and H2 receptors, whereas 4-methylhistamine is as active as histamine at H2 receptors. In vivo, VUF 8430 only caused a weak secretion of gastric acid mediated by H2 receptors, whereas 4-methylhistamine, dimaprit, histamine and amthamine, at equimolar doses, induced 2.5- to 6-fold higher output than VUF 8430.

CONCLUSIONS AND IMPLICATIONS

Our results suggest complementary use of 4-methylhistamine and VUF 8430 as H4 receptor agonists. Along with H4 receptor antagonists, both agonists can serve as useful pharmacological tools in studies of histamine H4 receptors.

Discovery of quinazolines as histamine H4 receptor inverse agonists using a scaffold hopping approach

From a series of small fragments that was designed to probe the histamine H(4) receptor (H(4)R), we previously described quinoxaline-containing fragments that were grown into high affinity H(4)R ligands in a process that was guided by pharmacophore modeling. With a scaffold hopping exercise and using the same in silico models, we now report the identification and optimization of a series of quinazoline-containing H(4)R compounds. This approach led to the discovery of 6-chloro-N-(furan-3-ylmethyl)2-(4-methylpiperazin-1-yl)quinazolin-4-amine (VUF10499, 54) and 6-chloro-2-(4-methylpiperazin-1-yl)-N-(thiophen-2-ylmethyl)quinazolin-4-amine (VUF10497, 55) as potent human H(4)R inverse agonists (pK(i) = 8.12 and 7.57, respectively). Interestingly, both compounds also possess considerable affinity for the human histamine H(1) receptor (H(1)R) and therefore represent a novel class of dual action H(1)R/H(4)R ligands, a profile that potentially leads to added therapeutic benefit. Compounds from this novel series of quinazolines are antagonists at the rat H(4)R and were found to possess anti-inflammatory properties in vivo in the rat.

Antiinflammatory and antinociceptive effects of the selective histamine H4-receptor antagonists JNJ7777120 and VUF6002 in a rat model of carrageenan-induced acute inflammation

The effects of the highly selective histamine H4 receptor antagonists JNJ7777120 and VUF6002 were investigated on the carrageenan-induced inflammation and thermal hyperalgesia in rats. JNJ7777120 (10 and 30 mg/kg, s.c.) and VUF6002 (10 mg/kg, s.c.) significantly reduced paw edema and hyperalgesia provoked by subplantar injection of carrageenan; the effect was evident against the early (2 h) phase of inflammation. An inactive analog of VUF6002, VUF6007 (10 mg/kg, s.c.) slightly aggravated paw edema, while leaving unaltered carrageenan-induced nociception. These findings indicate that histamine H4 receptors participate in the early phase of acute inflammation induced by carrageenan in rats, influencing both edema and thermal hyperalgesia.

Effects of cannabinoid receptor agonists on rat gastric acid secretion: discrepancy between in vitro and in vivo data

The effects of the cannabinoid (CB)-receptor agonists WIN55,212-2 and HU-210 and the selective CB(1)-receptor antagonist SR141716A were tested on in vitro and in vivo acid secretion assays from the rat. In the isolated gastric fundus from immature rats, WIN55,212-2 (0.001-30 microM), HU-210 (0.001-10 microM), or SR141716A (0.1-10 microM) did not change the basal acid output or acid responses to histamine, pentagastrin, or electrical field stimulation. HU-210 (0.3 micromol/kg, intravenously) inhibited the acid response to pentagastrin in anesthetized adult, young, or immature rats with lumen-perfused stomachs; moreover, HU-210 reduced vagally induced acid secretion in adult animals, its antisecretory effect being reversed by SR141716A (0.65 micromol/kg, intravenously). In vitro and in vivo data indicate that CB(1) receptors are not located on parietal cells but, rather, on vagal pathways (possibly at preganglionic sites) supplying the gastric mucosa. The lack of effect of CB-receptor ligands in vitro cannot be ascribed to the use of immature rats, since HU-210 inhibited stimulated acid secretion in vivo, irrespective of the animal age.

Scanning Electron Microscopy of the Choroid Plexus of the Lateral Ventricle of the Horse

The present study examined the ultrastructure of the choroid plexus of the lateral ventricle of the horse. The material was fixed in 2.5% glutaraldehyde in 0.1 m sodium phosphate buffer, pH 7.3, processed and analysed by scanning electron microscopy. The choroid plexus was characterized by regions with a predominance of villi, which resembled finger-like projections or bunches of grapes, and others where straight and uniform folds predominated. Epithelial cells projected into the ventricle and large amounts of cilia and microvilli were observed on their surface. The choroid glomus corresponded to a dilatation of the choroid plexus and was characterized by blood vessels of different calibres surrounded by connective tissue.

Effects of cyclooxygenase-1 and -2 inhibition on gastric acid secretion and cardiovascular functions in rats

The discovery of a second isoform of cyclooxygenase has led to a re-evaluation of the mechanisms underlying the adverse effects of nonsteroidal anti-inflammatory drugs, focusing in particular on the gastrointestinal system. We investigated the involvement of cyclooxygenase-1 and -2 in the regulation of gastric acid secretion and cardiovascular functions in anesthetized rats, after acute intravenous administration of the selective cyclooxygenase-1 inhibitor SC-560, the selective cyclooxygenase-2 inhibitor celecoxib and the nonselective inhibitor indomethacin. Indomethacin, celecoxib and SC-560 did not significantly modify basal acid secretion. Indomethacin and celecoxib were also ineffective on the acid secretion stimulated by pentagastrin; by contrast, SC-560 significantly enhanced the acid secretion stimulated by pentagastrin, electrical vagal stimulation or histamine. The stimulatory effects of SC-560 were prevented by cervical vagotomy, atropine and famotidine. Indomethacin caused either no change, increasing or decreasing effects on mean arterial pressure and heart rate. By contrast, SC-560 was unable to change cardiovascular parameters at 5 mg/kg, while inducing a marked bradycardia at 10 mg/kg. Celecoxib was ineffective. Our findings indicate that cyclooxygenase-1-derived prostaglandins are involved in the regulation of stimulated acid secretion and of basal heart rate; the role of prostaglandins in the acute control of systemic blood pressure under resting conditions seems to be negligible.

Gastric antisecretory effects of synthetic cannabinoids after central or peripheral administration in the rat

Previous studies have revealed that cannabinoid (CB)-receptor agonists inhibit gastric acid secretion stimulated by indirectly acting agents, but not by histamine. Aiming to investigate whether central or peripheral mechanisms are involved, the effects of the synthetic CB-receptor agonists WIN55,212-2 and HU-210, administered either intracerebroventricularly (i.c.v.) or intravenously (i.v.) to the anaesthetized rat with lumen-perfused stomach, against gastric acid secretion induced by pentagastrin were tested. Injected i.c.v., both WIN55,212-2 (50 and 100 microg/kg) and HU-210 (25, 50 and 100 microg/kg) were ineffective on either basal secretion or acid output induced by pentagastrin (7.7 microg/kg, i.v.). By contrast, i.v. injections of WIN55,212-2 (100 and 1000 microg/kg) or HU-210 (10-100 microg/kg) significantly inhibited pentagastrin-induced acid secretion, maximal reductions being 75.70 and 82.24% for WIN55,212-2 and HU-210, respectively. The gastric antisecretory effect of HU-210 was prevented by administration of the selective CB(1)-receptor antagonist SR141716A (1000 microg/kg, i.v.). These results show that CB(1)-receptors mediating inhibition of gastric acid secretion in the rat are mainly peripherally located.

Pharmacological evidence for beta3 adrenoceptors in the control of rat gastric acid secretion

The effect of the beta3-adrenoceptor agonist BRL37344 on gastric acid secretion evoked by different secretory stimuli was investigated in anaesthetized rats with lumen-perfused stomachs in comparison with the beta2-adrenoceptor agonist clenbuterol. Intravenous injections of BRL37344 (1-10 micromol/kg) and clenbuterol (0.01-1 micromol/kg) dose-dependently reduced 2-deoxy-D-glucose-induced acid secretion, with BRL37344 about forty times less potent than clenbuterol. BRL37344 (0.1-3 micromol/kg) inhibited pentagastrin-induced acid output, whereas clenbuterol was effective only at high doses (10-100 micromol/kg). The inhibitory effect of BRL37344 on pentagastrin-induced acid secretion was not modified by the nonselective beta-adrenoceptor antagonist propranolol, but it was prevented by bupranolol, a beta3-adrenoceptor antagonist. Furthermore, neither BRL37344 (10 micromol/kg) nor clenbuterol (100 micromol/kg) modified the acid secretion induced by histamine. These data suggest that beta3 adrenoceptors have an inhibitory role in the control of rat gastric acid secretion induced by indirect stimuli.

Gastric antisecretory role and immunohistochemical localization of cannabinoid receptors in the rat stomach

1. The role of cannabinoid (CB) receptors in the regulation of gastric acid secretion was investigated in the rat by means of functional experiments and by immunohistochemistry. 2. In anaesthetized rats with lumen-perfused stomach, the non selective CB-receptor agonist WIN 55,212-2 (0.30 - 4.00 micromol kg(-1), i.v.) and the selective CB(1)-receptor agonist HU-210 (0.03 - 1.50 micromol kg(-1), i.v.), dose-dependently decreased the acid secretion induced by both pentagastrin (30 nmol kg(-1) h(-1)) and 2-deoxy-D-glucose (1.25 mmol kg(-1), i.v.). By contrast, neither WIN 55,212-2 (1 - 4 micromol kg(-1), i.v.) nor HU-210 (0.03 - 1.50 micromol kg(-1), i.v.) did modify histamine-induced acid secretion (20 micromol kg(-1) h(-1)). The selective CB(2)-receptor agonist JWH-015 (3 - 10 micromol kg(-1), i.v.) was ineffective. 3. The gastric antisecretory effects of WIN 55,212-2 and HU-210 on pentagastrin-induced acid secretion were prevented by the selective CB(1)-receptor antagonist SR141716A (0.65 micromol kg(-1), i.v.) and unaffected by the selective CB(2)-receptor antagonist SR144528 (0.65 - 2 micromol kg(-1), i.v.). 4. Bilateral cervical vagotomy and ganglionic blockade with hexamethonium (10 mg kg(-1), i.v., followed by continuous infusion of 10 mg kg(-1) h(-1)) significantly reduced, but not abolished, the maximal inhibitory effect of HU-210 (0.3 micromol kg(-1), i.v.) on pentagastrin-induced acid secretion; by contrast, pretreatment with atropine (1 mg kg(-1), i.v.) did not modify the antisecretory effect of HU-210. 5. Immunoreactivity to the CB(1) receptor was co-localized with that of the cholinergic marker choline acetyltransferase in neural elements innervating smooth muscle, mucosa and submucosal blood vessels of rat stomach fundus, corpus and antrum. In contrast, CB(2) receptor-like immunoreactivity was not observed. 6. These results indicate that gastric antisecretory effects of cannabinoids in the rat are mediated by suppression of vagal drive to the stomach through activation of CB(1) receptors, located on pre- and postganglionic cholinergic pathways. However, the ineffectiveness of atropine in reducing the effect of HU-210 suggests that the release of non cholinergic excitatory neurotransmitters may be regulated by CB(1) receptors.

Role of histamine H3 receptors in the regulation of gastric functions

The role of central and peripheral histamine H3 receptors in the regulation of gastric acid secretion and gastric mucosal integrity is reviewed. The activation of H3 receptors by peripheral administration of the selective agonist (R)alpha-methylhistamine reduced acid secretion in cats, dogs, rats and rabbits, while increasing it in mice. The antisecretory effects were observed against indirect stimuli that act on vagal pathways or on enterochromaffin-like (ECL) cells, such as 2-deoxy-D-glucose, food or pentagastrin, but not against histamine or dimaprit. Inhibitory effects on acid production were observed in rats after central administration of histamine or of H3 receptor agonists. In the conscious rat intragastric administration of (R)alpha-methylhistamine caused gastroprotective effects against the damage induced by absolute ethanol, HCl, aspirin and stress. The mechanism involved seems to be related to the increased mucus production, via nitric oxide-independent mechanisms. Gastroprotective effects against ethanol were also observed after central administration of histamine or its metabolite N(alpha)-methylhistamine, suggesting that brain receptors participate the histamine-mediated effects on gastric functions.

[Intraoperative expansion of scalp flaps. Quantitative assessment]

BACKGROUND

The aim of this study was to test the ex-vivo biomechanical properties of acutely expanded scalp flaps, in order to quantitatively assess the efficacy of acute scalp expansion.

METHODS

A total of 14 fresh male cadavers were used for the study. In each cadaver, a rectangular (4 x 10 cm), laterally-based flap was designed on each side of the scalp, starting from the superior margin of the external auditory canal. One randomly-selected flap per each scalp underwent acute-intermittent expansion (3-minute expansion-3-minute rest cycle per three times with the maximal expansion achievable), while the contralateral flap served as control. After the expansion process, the acutely-expanded flaps were measured to assess if the applied biomechanical stress have determined any changes in their dimensions. The biomechanical properties (stress/strain ratio, mean stiffness) of both expanded and control flaps were then assessed by means of a dynamometer and a force-transducer.

RESULTS

The obtained data showed that the biomechanical benefits provided by acute scalp expansion were not statistically different (p < 0.05) from those obtained by simple subgaleal undermining. Neither any change of length nor any gain in the compliance have been observed in the acutely-expanded flaps as compared to control scalp flaps.

CONCLUSIONS

In our opinion, a possible explanation (to be further validated) for the lack of effect of acute scalp expansion might be that inelastic galea aponeurotica did not allow the mechanical creep to exploit the inherent elastic properties of the overlying scalp skin.

Antisecretory and gastroprotective activities of compounds endowed with H2 antagonistic and nitric oxide (NO) donor properties

In spite of the well recognized gastric antisecretory activity, the gastroprotective potential of histamine H2 receptor antagonists is controversial. Most clinical studies in fact indicate that these drugs do not substantially protect the gastric mucosa from aggressive factors. Nitric oxide (NO) has been recently recognized as a fundamental mediator in gastric defence mechanisms, due to its ability to increase gastric mucosal blood flow and mucus production and to inhibit neutrophils adherence to endothelial cells. The aim of this study was to investigate the gastroprotective and H2 receptor antagonistic activity of a series of lamtidine analogues which contain different NO-releasing moieties (furoxan, nitroxy and nitrosothiol). These compounds were tested, in comparison with related H2 antagonists devoid of NO-donor structures, in different H2 receptor assays and in the conscious rat against 0.6 N HCl-induced gastric lesions. All the compounds tested were able to antagonize histamine-mediated responses at cardiac and gastric H2 receptors; however, furoxan and nitroxy derivatives were 10-fold less potent than the analogues devoid of NO-donor properties. By contrast, NO-donor compounds were more active than reference H2 antagonists as gastroprotective agents against mucosal injury induced by 0.6 N HCl. Among the different NO-donor moieties, the furoxan group conferred to the H2 antagonist molecule the highest gastroprotective potential; this finding closely correlates with the characteristics of NO release. In conclusions, lamtidine-analogue H2 antagonists combined with NO-donor moieties are endowed with gastric antisecretory and protective activity and could be the prototypes of a new class of anti-ulcer drugs. Finally, the furoxan NO donor group seems to be the most favourable among the different moieties tested.

Inhibitory effect of the cannabinoid receptor agonist WIN 55,212-2 on pentagastrin-induced gastric acid secretion in the anaesthetized rat

The effect of the cannabinoid (CB) receptor agonist WIN 55,212-2 on gastric acid secretion was studied in the anaesthetized rat after stimulation with pentagastrin. WIN 55,212-2 (0.5-2 mg/kg, i.v.) was inactive on basal secretion but caused a marked inhibition (80%) of the acid secretion stimulated by pentagastrin (10 microg/kg, i.v.). The enantiomer WIN 55,212-3 (1-3 mg/kg, i.v.) did not significantly modify basal or pentagastrin-induced acid secretion. The inhibitory effect of WIN 55,212-2 against pentagastrin was prevented by the administration of the selective cannabinoid CB1 receptor antagonists SR141716A (1 mg/kg, i.v.) and LY320135 (1 mg/kg, i.v.); by contrast, the CB2 receptor antagonist SR144528 (0.3-1 mg/kg, i.v.) was without effect. The selective CB2 receptor agonist JWH-015 (0.1-10 mg/kg, i.v.) was inactive on the increase of acid output stimulated by pentagastrin. These results suggest that the inhibitory effect of WIN 55,212-2 on pentagastrin-stimulated acid secretion in the anaesthetized rat is mediated by specific cannabinoid receptors. Moreover, the antagonism of WIN 55,212-2-induced effects by the selective CB1 receptor antagonists SR141716A and LY320135 together with the ineffectiveness of both the CB2 receptor agonist JWH-015 and the CB2 receptor antagonist SR144528 indicate that CB1 receptor subtypes are predominantly involved in the antisecretory effect of WIN 55,212-2.

Synthesis of 1,2-benzisothiazole derivatives and investigation of their putative histaminergic activity

Some new 2-(1,2-benzisothiazol-3-yl)ethylamine derivatives were synthesised and their putative histaminergic activity was investigated in in vitro gastrointestinal and cardiac preparations. In the isolated guinea pig duodenum, all the compounds induced a tetrodotoxin- and atropine-sensitive contractile activity, which was minimally affected by mepyramine in the case of the compound 2-(1,2-benzisothiazol-3-yl)ethylamine. In the same tissue, all the compounds were devoid of any H3 receptor agonistic or antagonistic activity, but caused a nicotinic and/or 5-HT3 receptor activation. None of these compounds induced any histamine H2 agonistic or antagonistic activity in the isolated guinea pig gastric mucosa or in the isolated papillary muscle. On this latter substrate, the compound N,N,N-trimethyl-2-(1,2-benzisothiazol-3-yl)ethylammonium iodide induced a positive inotropic activity, apparently due to a release of catecholamines. These results demonstrate the substantial inability of 1,2-benzisothiazole derivatives to interact with histamine receptors in functional tests. These compounds, however, possess gangliomimetic properties, related to the activation of 5HT3 and/or nicotinic receptors.

The "parasite" TRAM flap for autogenous tissue breast reconstruction in patients with vertical midabdominal scars

Abdominal scars play an important role in risk factors in transverse rectus abdominis musculocutaneous (TRAM) flap breast reconstruction. In particular, vertical midline scars are a difficult problem to solve. Traditional techniques include the use of a single hemiflap (which may be insufficient to achieve an adequate volume), the transfer of a double-pedicle flap (which causes major trauma to the abdominal wall), or more complicated procedures such as two free hemiflaps. Since 1991 the authors have used an innovative technique to improve vascularity in the contralateral side of a standard unipedicled TRAM flap. They call this flap the recharged TRAM flap. By means of their technique, the retrograde flow coming from the deep inferior epigastric vessels raised in continuity with a superiorly pedicled flap is used to "recharge" the contralateral rectus muscle harvested as a free flap. On the basis of hemodynamic studies, this procedure was carried out in patients with vertical midabdominal scars. This flap was named the parasite flap because the free unit survives on the vascular source of the pedicled unit-the superior epigastric artery supplying both flaps in a retrograde fashion. Sixteen patients with vertical midabdominal scars underwent this procedure. Total flap survival was observed in 15 patients. One patient developed a partial flap necrosis and 1 patient developed abdominal bulging on the pedicled side. According to the surgeons' evaluation, aesthetic outcome was considered to be good to excellent in all patients.

SAR studies on H2 antagonists containing alkylamino substituted 1,2, 5-thiadiazole 1-oxide moieties

A number of ranitidine analogues in which the diamino-1,2,5-thiadiazole 1-oxide substructure bearing alkyl chains of different length is present as the urea equivalent group, were synthesised and studied for their lipophilic and H2 antagonist properties. Derivatives which displayed a logP < or = 3 behaved as competitive antagonists of histamine at H2 receptors present on guinea pig right atrium. The remaining more lipophilic members of the series showed an insurmountable antagonism not completely reversible after prolonged washing. A binding study suggested that an increase in the length of alkyl chain gave rise to hydrophobic interactions with the receptor which were responsible for the apparent irreversible H2 antagonism shown by the higher homologues of the series.

MK 801 and dexamethasone reduce both tumor necrosis factor levels and infarct volume after focal cerebral ischemia in the rat brain

Focal cerebral ischemia in rats produces elevated levels of tumor necrosis factor (TNF)alpha in the ischemic brain region. To better understand the modulation of TNF during brain ischemia processes we carried out studies in a model of permanent middle cerebral artery occlusion (MCAo) in the rat. In non-treated ischemic animals, the maximum expression of TNF was observed at 12 h (246.1+/-33 U/g) in the ischemic cortex and declined reaching near zero levels 24 h after MCAo. Given 10 min after MCAo, MK 801 (3 mg/kg, i.p.), a non-competitive NMDA receptor antagonist, exerted significant neuroprotection as measured by 47% reduction of total volume of infarction (P < 0.01 vs. ischemic-control). At the high dose of 3 mg/kg i.p., dexamethasone (DEX), which is known to reduce brain edema, decreased infarct size by 50% (P < 0.01 vs. ischemic-control). Both MK 801 and DEX reduced TNF production in the ipsilateral cortex of ischemic animals by 61 and 73%, respectively (P < 0.01 vs. ischemic-control). The data indicate that TNF levels increase after brain infarction, whereas they are reduced by neuroprotective agents, such as MK 801 and DEX, which act on different cellular levels.

Human defunctionalized colon: a histopathological and pharmacological study of muscularis propria in resection specimens

Despite the regression of "diversion colitis," temporary functional disorders after bowel continuity restoration could be caused by changes in the smooth muscle of excluded segments; however, studies on the muscularis propria have yielded contradictory results. This study was aimed at evaluating possible histopathological changes in muscular layers and motility of the defunctionalized human colon. Ten patients with defunctionalized colorectum (group A) and 10 controls (group B) underwent restorative or primary resection surgery. Strips were taken proximal to the colostomy (specimens A1) and the defunctionalized segment (specimens A2), and from the proximal (specimens B1) and distal extremity (specimens B2) of resected colons. Measurements of the thickness of the muscularis propria and of the volume density of the myenteric plexus, as well as of spontaneous motility and responses to electrical and pharmacological stimulation were taken. The muscularis propria was thicker in A2 than in A1 specimens (P = 0.004) and in B2 than in B1 specimens (P = 0.007). No differences were recorded either in the myenteric plexus volume density or in colonic motility. No differences were recorded in intergroup comparisons. As no structural or functional changes related to defunctionalization were found, clinical disorders after colorectal restoration could rather result from underlying colonic pathology and/or incomplete distal colon resection.

Adenosine A2A receptors and neuroprotection

The adenosine A2A receptor subtype is one of the four adenosine receptors that have been identified in the mammalian organism. In addition to being found in blood vessels, platelets and polymorphonuclear leukocytes, the A2A receptors are abundant in the central nervous system, especially in the striatum. The recent development of selective A2A receptor ligands, in particular of receptor antagonists, makes it possible to elucidate the function of A2A receptors in normal and altered conditions. Pharmacological studies have shown that A2A receptor antagonists are potentially effective for treatment of neurodegenerative processes such as Parkinson's disease. Their activity is attributed to the close anatomical and functional links between A2A receptors and dopaminergic pathways in the basal ganglia. More recently, A2A receptor antagonists have proved to be active in models of cerebral ischemia. While the mechanisms underlying the role of A2A receptors in the hypoxia/ ischemia processes remains to be clarified, it is recognized that A2A receptor antagonists counteract the effects of excitatory aminoacids, which are massively released after cerebral ischemia. Another function of A2A receptors is related to protection from seizures, but further studies are needed to elucidate their specific interaction, if any, with neuronal excitability. Altogether, the great advance recently made with the discovery of selective A2A receptor ligands provides increasing information on the function of A2A receptors and opens new perspectives for treatment of neurological disorders.

Systemic interleukin 10 administration inhibits brain tumor necrosis factor production in mice

Interleukin 10 is an antiinflammatory cytokine and inhibits the production of tumor necrosis factor. We have previously found that intracerebroventricular (i.c.v.) administration of recombinant human interleukin 10 inhibits brain tumor necrosis factor production induced by an i.c.v. injection of lipopolysaccharide in mice. In view of its possible pharmacological use, we have now studied whether interleukin 10 administered peripherally could inhibit brain tumor necrosis factor production. Mice were injected with recombinant human interleukin 10 (20 microg/mouse, i.v.) 10 min-24 h before lipopolysaccharide (2.5 microg, i.c.v.). Tumor necrosis factor was measured, using a bioassay, in brain homogenates 90 min after lipopolysaccharide. Recombinant human interleukin 10 administered i.v. between 10 min and 6 h before lipopolysaccharide markedly inhibited brain tumor necrosis factor production. We also measured the production of tumor necrosis factor by whole blood of these mice, and it was also markedly inhibited by recombinant human interleukin 10 treatment. In conclusion, systemic recombinant human interleukin 10 administration inhibits brain tumor necrosis factor production. suggesting its usefulness in tumor necrosis factor-mediated pathologies of the central nervous system.

Mixed antisecretory and gastroprotective activities of a new H2-antagonist containing a nitric oxide-donor furoxan moiety

The effect of a new histamine H2-receptor antagonist derived from the lamtidine molecule and containing a nitric oxide (NO)-donor furoxan moiety (derivative 1) was studied for its gastric antisecretory activity and for a possible gastroprotective effect, in comparison with the analog without the furoxan moiety (derivative 2). The H2-receptor antagonistic activity was also investigated in the isolated guinea pig papillary muscle. Derivative 1 was approximately 10 times less potent than derivative 2 at the H2-receptor level; conversely, it was about 10 times more effective as a gastroprotective agent against ethanol- and 0.6 N HCl-induced gastric lesions. The mechanism of the gastroprotection exerted by derivative 1 is probably connected with the release of NO, whose vasodilating action on gastric mucosa vessels is crucial. The combined antisecretory and gastroprotective activity of derivative 1 allows this compound to be considered as a prototype of a new class of antiulcer agents.

Effect of fedotozine on human distal colon

Fedotozine was rested in colonic strips removed during surgery from patients suffering from different diseases of the colon; the effects were compared to those of morphine and of the selective opiate agonist U-69593. Fedotozine did not affect the spontaneous motility of human colonic strips, unless very high concentrations were used. Fedotozine (10(-6)-3 x 10(-4) M) induced a concentration-dependent reduction of the excitatory effect induced by field stimulation, an effect which was partially mimicked by compound U-69593 and by morphine but not inhibited by naloxone. The cumulative dose-response curve to exogenous acetylcholine was inhibited by fedotozine (3 x 10(-4) M), whereas morphine had no effect up to 3 x 10(-4) M. In colonic strips incubated with [3H]-choline, fedotozine (10(-5)-10(-4) M) induced an erratic decrease of acetylcholine-release induced by electric stimulation. In our experimental model, the inhibitory effect of fedotozine does not seem to be related to opioid receptor activation.

Cardiac and gastric effects of histamine H2 receptor antagonists: no evidence for a correlation between lipophilicity and receptor affinity

1. A series of histamine H2 receptor antagonists with different lipophilicity were tested in cardiac and gastric assays in order to reveal possible differences in receptor affinity. Lipophilicity of the compounds was expressed as CLOG P (theoretically-determined logarithm of octanol:water partition coefficient) and log k' (logarithm of capacity factor, experimentally-determined by reverse-phase high performance liquid chromatography). 2. Aminopotentidine (APT) and iodoaminopotentidine (I-APT), which are both lipophilic compounds, behaved as insurmountable antagonists of histamine responses in rat isolated gastric fundus (pKB = 6.20 +/- 0.16 and 6.89 +/- 0.19, respectively) and guinea-pig isolated papillary muscle (pKB = 6.34 +/- 0.37 and 6.81 +/- 0.26, respectively). They were approximately as effective as ranitidine (RAN) in reducing histamine-induced acid secretion in the anaesthetized rat, ID50 values being 0.018 +/- 0.02, 0.020 +/- 0.03 and 0.036 +/- 0.01 mumol kg-1 i.v. for APT, I-APT and RAN, respectively. Both APT and I-APT had a significantly longer duration of action than RAN. 3. The hydrophilic compound, SK&F 92857, was inactive up to 10 microM in modifying histamine-induced acid secretion in the isolated rat stomach. In the papillary muscle, low concentrations (0.1-1 microM) of this compound produced a competitive antagonism of the histamine responses (pA2 value = 7.38 +/- 0.11), while a higher concentration (10 microM) significantly reduced the maximal response to histamine. 4. RAN competitively antagonized histamine effects with a comparable affinity in cardiac and gastric preparations (pA2 values were 6.42 +/- 0.09 and 6.78 +/- 0.38 in heart and stomach, respectively). 5. Results obtained in this study clearly showed that the discrepancies between gastric and cardiac effects observed for some H2 antagonists are not explained solely by differences in lipophilicity of compounds. Moreover, the significant correlation found between CLOG P and log k' parameter, which takes into account, besides their lipophilicity, the ionization of the molecules, suggests that ionization has a similar influence for all the molecules on the partition between the lipophilic and aqueous phase.

Potentiometric alternating biosensing system for in continuum toxicity tests on cell population

In this paper, we investigate the possibility to monitor, in continuum, changes of cellular metabolism. Examples of this feature are shown: metabolic changes due to drugs administration are evaluated as a decrease of extracellular acidification rate on CHO-K1 and HeLa cells. Parallel experiments with a standard test were performed to validate the results obtained with the biosensor.

Neuroprotective effects of felbamate on global ischaemia in Mongolian gerbils

Felbamate is an antiepileptic drug whose action appears to occur mainly through an interaction with neurotransmission mediated by excitatory amino acids. We assessed its effectiveness in a model of transient global ischaemia in Mongolian gerbils. Dizocilpine (MK 801) was used for comparison. Treatment was given 10 min after transient forebrain ischaemia which was performed by occluding both common carotid arteries for 10 min. Felbamate (300 mg/kg i.p.) increased the number of surviving neurons in the CA1, CA2 and CA3 hippocampal cells. In particular, the CA1 area had a significantly higher number of surviving pyramidal neurons than that of vehicle-treated animals (67 +/- 11 vs 33 +/- 6 surviving neurons/mm; P < 0.05). No significant difference in density of surviving neurons was observed between dizocilpine (3 mg/kg i.p.) and vehicle (54 +/- 10 vs 33 +/- 6 surviving neurons/mm). The EEG results indicated that the effect of felbamate, used alone, is the same in the ischaemic-vehicle group as non-ischaemic group. Our results show that felbamate exerts neuroprotective effects in a model of severe cerebral ischaemia.