Porous Functionally Graded Scaffold prepared by a single-step freeze-drying process. A bioinspired approach for wound care

Nowadays, chronic wounds are the major cause of morbidity worldwide and the healthcare costs related to wound care are a billion-dollar issue; chronic wounds involve a non-healing process that makes necessary the application of advanced wound dressings to promote skin integrity recovery. Functionally Graded Scaffolds (FGSs) are currently driving interest as promising candidates in mimicking the skin tissue environment and, thus, in enhancing a faster and more effective wound healing process. Aim of the present work was to design and develop a porous FGS based on κ-carrageenan (κCG) for the management of chronic skin wounds; a freeze-drying process was optimized to obtain in a single-step a three-layered FGS characterized by a pore size gradient functional to mimic the structure of native skin tissue. In addition to κCG, arginine and whey protein isolate were used as multifunctional agents for FGS preparation; these substances can not only intervene in some stages of wound healing but are able to establish non-covalent interactions with κCG, which were responsible for the production of layers with different pore size, water content capability and mechanical properties. Cell migration, adhesion and proliferation within the FGS structure were evaluated in vitro on fibroblasts and FGS wound healing potential was also studied in vivo on a murine model.

The Freeze-Drying of Pharmaceuticals in Vials Nested in a Rack System-Part II: Primary Drying Behaviour

The freeze-drying of biopharmaceuticals is a common strategy to extend their shelf-life and facilitate the distribution of therapeutics. The drying phase is the most demanding one in terms of energy consumption and determines the overall process time. Our previous work showed how the loading configuration can impact freezing. This paper focuses on primary drying by comparing the thermal behaviour of vials loaded in direct contact with the shelf or nested in a rack system. The overall heat transfer coefficient from the apparatus to the product was evaluated at different chamber pressures (5-30 Pa) and shelf temperatures (from -10 °C to +30 °C), and in the case of various vial positions (central, semi-border, and border vials). Because of the suspended configuration, the heat transfer coefficient was less affected by chamber pressure in vials nested in a rack system. The two loading configurations displayed comparable heat transfer efficiency below 10 Pa. For higher chamber pressure, the heat transfer coefficients of nested vials were lower than those of vials in direct contact with the shelf. Nevertheless, the rack system was beneficial for reducing the inter-vial variability as it promoted higher uniformity in the heat transfer coefficients of central vials. Eventually, thermal image analyses highlighted limited temperature differences between the vials and the rack system.

Freeze-Drying of Pharmaceuticals in Vials Nested in a Rack System-Part I: Freezing Behaviour

The distribution of biopharmaceuticals often requires either ultra-cold conditions or lyophilisation. In both cases, the drug product is frozen and, thus, exposed to similar stress conditions, which can be detrimental to its quality. However, these stresses can be inhibited or mitigated by a suitable formulation and/or an appropriate freezing design. This paper addresses how the key freezing parameters, i.e., ice nucleation temperature and cooling rate, impact the freezing behaviour of a sucrose-based formulation. The analysis included two loading configurations, vials directly resting on the shelf and nested in a rack system. The loading configuration affected the product freezing rate and the ice nucleation temperature distribution, resulting in larger ice crystals in the case of vials nested in a rack system. SEM micrographs and specific surface area measurements confirmed the different product morphology. Eventually, the different product morphology impacted the bioactivity recovery of lactate dehydrogenase.

27-Hydroxycholesterol inhibits rhinovirus replication in vitro and on human nasal and bronchial histocultures without selecting viral resistant variants

The genetic plasiticity of viruses is one of the main obstacles to the development of antivirals. The aim of this study has been to assess the ability of two physiologic oxysterols and host-targeting antivirals - namely 25- and 27-hydroxycholesterol (25OHC and 27OHC) - to select resistant strains, using human rhinovirus (HRV) as a challenging model of a viral quasispecies. Moreover, we selected 27OHC for further studies aimed at exploring its potential for the development of antiviral drugs. The results obtained with clonal or serial passage approaches show that 25OHC and 27OHC do not select HRV oxysterol-resistant variants. Moreover, we demonstrate the ability of 27OHC to inhibit the yield of HRV in 3D in vitro fully reconstituted human nasal and bronchial epithelia from cystic fibrosis patients and prevent virus-induced cilia damage. The promising antiviral activity of 27OHC and its competitive advantages over direct-acting antivirals, make this molecule a suitable candidate for further studies to explore its clinical potential.

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.

Quantitative Trait Loci Mapping and Identification of Candidate Genes Linked to Fruit Acidity in Apricot (Prunus armeniaca L.)

Apricot breeding programs could be strongly improved by the availability of molecular markers linked to the main fruit quality traits. Fruit acidity is one of the key factors in consumer acceptance, but despite its importance, the molecular bases of this trait are still poorly understood. In order to increase the genetic knowledge on the fruit acidity, an F1 apricot population ('Lito' × 'BO81604311') has been phenotyped for titratable acidity and juice pH for the three following years. In addition, the contents of the main organic acids of the juice (malate, citrate, and quinate) were also evaluated. A Gaussian distribution was observed for most of the traits in this progeny, confirming their quantitative inheritance. An available simple sequence repeat (SSR)-based molecular map, implemented with new markers in specific genomic regions, was used to perform a quantitative trait loci (QTL) analysis. The molecular map was also anchored to the recently published apricot genome sequence of 'Stella.' Several major QTLs linked to fruit acidity-related traits have been identified both in the 'Lito' (no. 21) and 'BO81604311' (no. 13), distributed in five linkage groups (LG 4, 5, 6, 7, and 8). Some of these QTLs show good stability between years and their linked markers were used to identify candidate genes in specific QTLs genomic regions.

The cholesterol metabolite 27-hydroxycholesterol inhibits SARS-CoV-2 and is markedly decreased in COVID-19 patients

There is an urgent need to identify antivirals against the coronavirus SARS-CoV-2 in the current COVID-19 pandemic and to contain future similar emergencies early on. Specific side-chain cholesterol oxidation products of the oxysterols family have been shown to inhibit a large variety of both enveloped and non-enveloped human viral pathogens. Here we report on the in vitro inhibitory activity of the redox active oxysterol 27-hydroxycholesterol against SARS-CoV-2 and against one of the common cold agents HCoV-OC43 human coronavirus without significant cytotoxicity. Interestingly, physiological serum levels of 27-hydroxycholesterol in SARS-CoV-2 positive subjects were significantly decreased compared to the matched control group, reaching a marked 50% reduction in severe COVID-19 cases. Moreover, no correlation at all was observed between 24-hydroxycholesterol and 25-hydroxycholesterol serum levels and the severity of the disease. Opposite to that of 27-hydroxycholesterol was the behaviour of two recognized markers of redox imbalance, i.e. 7-ketocholesterol and 7β-hydroxycholesterol, whose serum levels were significantly increased especially in severe COVID-19. The exogenous administration of 27-hydroxycholesterol may represent in the near future a valid antiviral strategy in the worsening of diseases caused by present and emerging coronaviruses.

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27-hydroxycholesterol (27OHC) inhibits the replication of SARS-CoV-2 by interfering with its entry into target cells.

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The broad antiviral effect of 27OHC is also exerted against another β-coronavirus, HCoV-OC43.

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Blood levels of 27OHC were decreased in SARS-CoV-2 infected individuals, especially in patients with severe COVID-19.

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COVID-19 patients showed increased serum levels of 7-ketocholesterol and 7β-hydroxycholesterol, markers of oxidative stress.

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.

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.

Injectability evaluation: an open issue

The current work aimed to propose a system of scoring to rationalize and support the selection of the optimal diameter and length of needles. Four formulations at different viscosity and needles ranging from 21 to 26 G and length ranging from 16 to 40 mm were used. Plunger-stopper breakloose force, maximum force (F(max)), and dynamic glide force were measured by a texture analyzer at the crosshead speed of 1 mm/s. Testing was carried out into air or human subcutaneous tissue. The manual injectability of the highest viscosity product was assessed by ten evaluators. The comparison of the panel test score and the quantitative measurements of the forces permitted to score a given needle-syringe-formulation system keeping also in consideration the pressure created in the subcutaneous space and muscles at the injection site. In particular, the following relationship was drawn: at the F(max) up to 250 mPa, the injection was practically impossible; at F(max) ranging from 160 to 250 mPa, the injection was very difficult; at F(max) in the 125-160 mPa range, the injection was feasible, though with some difficulty; when the values of F(max) were lower 125 mPa, the injection went smoothly. On the basis of these preliminary data, a system of scoring the needle-syringe-formulation system is proposed to rationalize and support the selection of the optimal diameter and length of needles, keeping also in consideration the pressure created in the subcutaneous space and muscles at the injection site.

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.

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.

Response variability to ischemic injury in the Mongolian gerbil: an electroencephalographic and behavioral study

The early effects of 5 or 10 min global cerebral ischemia, sham operation and halothane anesthesia were evaluated in Mongolian gerbils by means of electroencephalography (EEG), neurological examination and passive avoidance training. The "ischemia-sensitive" gerbils (33% and 64% of the 5 and 10 min ischemic groups, respectively) died during carotid ligation or within 24 h; the "ischemia-resistant" gerbils showed variable behavioral responses. Six hours after ischemia, all of the animals presented EEG activity characterized by increased delta (1-4 Hz) activity and a decreased theta 2 (6-9 Hz) band, with a tendency to recovery at 24 h. Learning impairment was observed in 5 of the 5 min ischemic animals (83%) and in 1 sham (17%) and 1 halothane (17%) control. Fourteen days after ischemia, histologic damage was observed in 4 ischemic gerbils and 1 sham control. On the whole, this study confirms the widely variable susceptibility of gerbils to cerebral ischemia. Moreover, although the variable effects of carotid occlusion have been attributed to multiple factors involving the cerebrovascular system, our data suggest that endogenous cellular mechanisms might protect against ischemia. In view of this consideration, it would be useful to investigate the molecular causes of the variable cerebral ischemic tolerance shown by Mongolian gerbils.

Effects of four antiepileptic drugs on sleep and waking in the rat under both light and dark phases

Sedation is a common side effect of anticonvulsant drug therapy. To find out whether the new antiepileptic drugs, felbamate and lamotrigine, are able to produce sedation, we carried out electroencephalographic (EEG) studies in the rat to measure drug effects on sleep-wake patterns, during both light and dark phases. For comparison, the reference drugs, carbamazepine and phenobarbital, were also studied. EEG activity was recorded for 6 h after oral (PO) administration of drugs or vehicle, and the stages of wakefulness, rapid eye movements (REM) sleep and non-REM sleep were classified thereafter. In the light phase, felbamate (30-300 mg/kg) did not produce sedative effects, while lamotrigine (3-30 mg/kg) increased wakefulness at each dose tested. Carbamazepine (10-100 mg/kg) did not produce sleep-wake alterations, and phenobarbital (100 mg/kg) markedly suppressed REM. In the dark phase, felbamate (300 mg/kg), lamotrigine (30 mg/kg), and carbamazepine (100 mg/kg) reduced REM but did not change the total amount of sleep. Phenobarbital, at 100 mg/kg, markedly increased total sleep and greatly reduced REM. This study shows that the anticonvulsant drugs examined have different effects on the states of sleep and wakefulness in the rat. The data are discussed on the basis of the mechanism of action that characterizes each individual drug.

Effects of repeated administration of selective adenosine A1 and A2A receptor agonists on pentylenetetrazole-induced convulsions in the rat

The protective effects of the selective adenosine A1 receptor agonist 2-chloro-N(6)-cyclopentyladenosine (CCPA), the selective adenosine A2A receptor agonist, 2-hexynyl-5'-N-ethylcarboxamidoadenosine (2HE-NECA), and the non-selective agonist, 5'-N-ethylcarboxamidoadenosine (NECA) were studied against lethal seizures induced by intraperitoneal (i.p.) injection of pentylenetetrazole (80 mg/kg). In acute studies there was a dose-dependent reduction of lethal seizures, as shown by the low dose's protecting 50% of animals (PD50): 0.11, 0.05 and 0.05 mg/kg i.p. for CCPA, 2HE-NECA and NECA, respectively. In the repeated administration studies the animals received either vehicle or drug i.p. twice daily for 12 days. The drug doses were twice the PD50 value: 0.3 mg/kg for CCPA or 0.1 mg/kg for both 2HE-NECA and NECA. 2HE-NECA and NECA maintained their protective activity against pentylenetetrazole-induced seizures (63% or 60% vs. 60% or 58% in acute studies, respectively). Conversely, repeated treatment with CCPA resulted in a marked decrease of its effects (67% vs. 30% in acute studies; P < 0.05). The data indicate that in addition to adenosine A1 the A2A receptors also appear to be involved in the protection from seizures. The anticonvulsant effects induced by repeated stimulation of adenosine A1 receptors are subject to tolerance, whereas effects depending on adenosine A2A receptor activation are maintained.

Gastric antisecretory activity of lansoprazole in different experimental models: comparison with omeprazole

1. The activity of the novel proton pump with inhibitor lansoprazole was examined in different gastric secretion models in vitro and in vivo, in comparison with omeprazole. 2. In the conscious cat with gastric fistula lansoprazole (0.25-2 mumol/kg i.v.) caused a dose-dependent reduction of the acid secretion induced by dimaprit, pentagastrin, 2-deoxy-D-glucose and bombesin, being approximately as potent as omeprazole (0.25-1.5 mumol/kg i.v.). Similar to omeprazole, lansoprazole was also more effective when administered in hyperacidic states. 3. In the anaesthetized rat with lumen perfused stomach lansoprazole (0.03-1 mumol/kg i.v.) was approximately 3 times more potent than omeprazole (0.1-3 mumol/kg i.v.) in inhibiting the acid secretion induced by histamine, 2-deoxy-D-glucose and forskolin. 4. In the isolated gastric fundus from the immature rat lansoprazole (1-30 microM) reduced basal acid secretion and the acid response to histamine and forskolin, with a potency not significantly different from that of omeprazole. 5. No significant differences were found in the different species between lansoprazole and omeprazole as for the duration of action. 6. In conclusion, lansoprazole exerts a marked antisecretory effect in a variety of gastric secretion models from different species. However, it did not significantly differ from omeprazole when considering either the potency or the duration of action.

Distemper in wild carnivores: an epidemiological, histological and immunocytochemical study

Brain tissue from 236 wild carnivores, 146 mustelids and 90 foxes, originating from the same geographical area in southwest Germany was collected over a 2 year period between May 1989 and May 1991 and studied for the presence of canine distemper virus (CDV) antigen by immunohistochemistry. CDV antigen was found in the brains of 54 (37%) mustelids, predominantly in the cerebellar grey matter. Interestingly, no CDV infection was observed in foxes. An increasing number of CDV infections among mustelids was noted between November 1989 and November 1990, peaking in summer 1990. Histological brain lesions, demonstrated only in 45% of the CDV positive mustelids, were characterized by non-purulent encephalitis predominantly in the cerebrum and focal vacuolation of the cerebellar white matter, whereas demyelination was only rarely observed. Histological and immunocytochemical CNS findings indicate an early stage of distemper infection in these mustelids and the high percentage of CDV positive animals together with the seasonal prevalence are suggestive of a CDV epizootic among mustelids.

The Mongolian gerbil in experimental epilepsy

The Mongolian gerbil is recognized as a suitable experimental model for studying epileptiform seizures. About 10-20% of the gerbils provided by animal breeders show convulsions when placed in a new laboratory environment or handled for drug administration. In this review, the usefulness of the gerbil is critically evaluated on the basis of the literature available and our experience. Since gerbils often react with seizures in response to external stimuli we utilized a blast of compressed air. Seven gerbils were tested once weekly, for 15 consecutive weeks, and electroencephalographic (EEG) activity was recorded. When the animals were challenged by a blast of compressed air they developed seizures, but with varying intensity and frequency. In the first weeks the majority of gerbils did not show seizures but they began to be susceptible to the stimulus from the 5th or 6th week. Four out of 7 animals proceeded to more severe seizures, characterized by clonic-tonic components. The pattern of behavioral seizures was paralleled by changes in the EEG recording. Altogether, data available indicate that the gerbil model is interesting in ethological studies and may be useful for investigating the mechanisms underlying "spontaneous" seizures. In pharmacology, however, the model has some weaknesses which limit its application in the study of new and established antiepileptic drugs.

Sleep-wake variables and EEG power spectra in Mongolian gerbils and Wistar rats

Using electroencephalographic methods (EEG), we have analyzed the basal sleep structure and the EEG power spectra of gerbils and rats during periods of wakefulness (W), synchronized sleep (SS) and paradoxical sleep (PS). During the 6 hr light period examined, duration of sleep was similar for rats and gerbils, but gerbils showed fewer PS episodes and a longer amount of SS episodes followed by wakefulness. In addition, SS episodes preceding PS were of longer duration in gerbils than in rats. EEG power spectral analysis indicated a higher relative output in the 1-4 Hz range in gerbils in comparison with rats. On the whole, the data indicate the existence of significant differences in the basal sleep structure and EEG power spectra of gerbils and rats. This background information might be useful in the comparison of the effects of a given experimental treatment, such as cerebral ischemia, on the EEG activity of these two animal species.

Activity of the new histamine H2-receptor antagonist zolantidine at cardiac and gastric H2-receptors

The effect of the new histamine H2-receptor antagonist zolantidine was studied in different cardiac and gastric H2-receptor assays in comparison with ranitidine. Zolantidine (0.1-10 mumol/l) competitively antagonized the positive effects of histamine in the spontaneously beating guinea pig atria and in the electrically stimulated guinea pig papillary muscle (pA2 values were 6.98 and 6.78, respectively). At the highest concentrations zolantidine also reduced basal heart rate and cardiac contractility. In the isolated rat gastric fundus zolantidine up to 100 mumol/l did not modify histamine-induced acid secretion; it was similarly ineffective against dimaprit-induced acid secretion in the gastric fistula of conscious cats (up to 3 mumol/kg i.v.) and against histamine in the anesthetized rat with lumen-perfused stomach (up to 30 mumol/kg i.v.). In all these gastric secretory models ranitidine, as expected, antagonized histamine H2-receptor-mediated responses, showing a potency comparable to that found in cardiac preparations (pA2 values were 6.84, 6.38 and 6.78 in the atria, papillary muscle and gastric fundus, respectively). These data clearly showed that zolantidine is a very peculiar histamine H2-receptor antagonist, capable of distinguishing between cardiac and gastric H2-receptors; however, it still has to be elucidated whether this depends on a true heterogeneity in the histamine H2-receptor population or on the physicochemical properties of the drug.

Mandible reconstruction with metallic endoprosthesis following Commando's operation for advanced head and neck cancer. Personal experience

Invasion of the mandible is found in 22% to 29% of advanced (Stage III-IV) head and neck cancers; only an aggressive surgical technique, such as Commando's operation with subsequent reconstruction of tissue defects, can give a chance of cure to these patients. The reconstruction is feasible both by means of microsurgical free-tissue transfers or with alloplastic materials and myocutaneous flaps. Between 1982 and 1991, 34 patients in Stage III (n = 6; 17.7%) and IV (n = 28; 82.3%) head and neck cancers underwent Commando's operation with different types of reconstruction in 30 patients: pectoralis myocutaneous flap (n = 9), osteo-myocutaneous flap with the underlying segment of the fifth rib (n = 2), myocutaneous flap plus prosthesis (n = 17), or prosthesis alone (n = 2). Two different prostheses were implanted: the linear A-O mandibular reconstruction plate (n = 13), and the Dumbach titanium cage (n = 6). In the group of patients in which the linear A-O mandibular reconstruction plate was used there were four cases of prosthesis dislodgement and major exposure and one case of prosthesis breakage while in patients who were given the Dumbach titanium cage there were four cases of major exposure. Prosthesis removal was required in five and two patients with linear A-O and Dumbach titanium cage prosthesis, respectively. Median survival was 14 months with 28% five-year survival. In our experience, metallic prostheses with a shape and arrangement that allow a distribution of traction forces on a wider surface, with screws drilled in nonaligned points of the mandible, seem to be more reliable as they reduce the risk of dislodgement and breakage.

The new potent and selective histamine H2 receptor agonist amthamine as a tool to study gastric secretion

The new histamine H2 receptor agonist amthamine, [2-amino-5-(2-aminoethyl)-4-methylthiazole], was tested for its activity on gastric acid secretion in different in vivo and in vitro experimental models. Amthamine induced a dose-related increase in acid secretion both in conscious cats with a gastric fistula (ED50 = 0.069 mumol/kg/h) and in anaesthetized rats with a lumen-perfused stomach (ED50 = 11.69 mumol/kg i.v.). In this last preparation the efficacy of amthamine was significantly higher than that of histamine and dimaprit. Amthamine was an effective secretagogue also in the rat isolated gastric fundus, behaving as a full agonist (EC50 = 18.9 mumol/l). In all the experimental models amthamine was more potent than dimaprit (from 3 to 10 fold) and approximately equipotent with histamine, and its effect was competitively antagonized by the histamine H2 receptor antagonists famotidine or ranitidine. Experiments with H1 and H3 receptor antagonists indicated that amthamine is devoid of stimulatory activity at H1 and H3 receptors. The present data indicate that amthamine is a full agonist at histamine H2 receptors and, being more effective and selective than the other compounds of the family, it may represent a good alternative to the other available histamine H2 receptor agonists for the study of gastric acid secretion.