Liver stiffness reduction and serum fibrosis score improvement in HIV/hepatitis C virus-coinfected patients treated with direct-acting antivirals

OBJECTIVES

Only a few studies have addressed liver stiffness dynamics after hepatitis C virus (HCV) treatment in patients with HIV/HCV coinfection. The aim was to evaluate the variation in liver stiffness and in serum liver fibrosis scores in HIV/HCV-coinfected patients before and after treatment with direct-acting antivirals (DAAs).

METHODS

Liver stiffness measured using transient elastography as well as serum liver fibrosis scores [fibrosis-4 (FIB-4) score and the aspartate aminotransferase to platelet ratio index (APRI)] were evaluated before and at 6-12 months after DAA treatment. Variation in the outcome variables was evaluated using the Wilcoxon nonparametric test. Univariate analysis and multivariate regression models were used.

RESULTS

A total of 78 HIV/HCV-coinfected subjects were included in the study. Median values of hepatic stiffness significantly decreased after DAA treatment compared with baseline [16.8 (interquartile range (IQR) 10.2-27.0) kPa at baseline vs. 9.4 (IQR 6.7-15.0) kPa after DAA treatment; P < 0.01). Further, a decrease in median FIB-4 score [2.8 (IQR 1.5-4.8) vs. 2.0 (IQR 1.3-3.2), respectively; P < 0.01] and APRI [0.9 (IQR 0.5-2.2) vs. 0.4 (IQR 0.2-0.7), respectively; P < 0.01] was found. In univariate analysis, liver stiffness decrease was associated with increasing age, 'other' HCV genotype (vs. G1), the presence of cirrhosis, higher pre-DAA liver stiffness, sofosbuvir-based regimens and longer DAA treatment (all P < 0.05). Multivariate regression confirmed the significance of the association only with higher baseline liver stiffness (P < 0.01). Greater FIB-4 and APRI reductions were associated with higher respective baseline values, while the presence of hepatic steatosis correlated with lower score reduction after DAA.

CONCLUSIONS

A reduction in liver stiffness and an improvement in fibrosis scores were observed in HIV/HCV-coinfected patients soon after DAA treatment. The clinical implications of these observations need to be evaluated in larger populations with longer follow-up.

Mucin-Producing Adenoma of the Thyroid Gland

The authors studied a case of mucin-producing adenoma of the thyroid gland. The tumor consisted almost entirely of signet-ring cells containing mucin, which was strongly positive with PAS, with and without diastase pre-treatment, and Alcian blue stain at pH 2.5. Immuno-peroxidase staining for thyreoglobulin was clearly positive within the cytoplasm of signet-ring cells and also in the follicle material, which indicates that the tumor derived from follicular epithelium.

Metastasizing Meningeal Melanocytoma

The first case in the literature of a metastasizing meningeal melanocytoma is described. The tumor, which arose at the D9-D11 spinal cord level of a 46-year-old woman, metastasized 7 years later to the latero-suprasellar region.

Increased risk of virologic failure to the first antiretroviral regimen in HIV-infected migrants compared to natives: data from the ICONA cohort

Migrant and Italian HIV-infected patients (n = 5773) enrolled in the ICONA cohort in 2004-2014 were compared for disparities in access to an initial antiretroviral regimen and/or risk of virologic failure (VF), and determinants of failure were evaluated. Variables associated with initiating antiretroviral therapy (ART) were analysed. Primary endpoint was time to failure after at least 6 months of ART and was defined as: VF, first of two consecutive virus loads (VL) >200 copies/mL; treatment discontinuation (TD) for any reason; and treatment failure as confirmed VL >200 copies/mL or TD. A Poisson multivariable analysis was performed to control for confounders. Migrants presented significantly lower CD4 counts and more frequent AIDS events at baseline. When adjusting for baseline confounders, migrants presented a lower likelihood to begin ART (odds ratio 0.80, 95% confidence interval (CI) 0.67-0.95, p 0.012). After initiating ART, the incidence VF rate was 6.4 per 100 person-years (95% CI 4.8-8.5) in migrants and 2.7 in natives (95% CI 2.2-3.3). Multivariable analysis confirmed that migrants had a higher risk of VF (incidence rate ratio 1.90, 95% CI 1.25-2.91, p 0.003) and treatment failure (incidence rate ratio 1.16, 95% CI 1.01-1.33, p 0.031), with no differences for TD. Among migrants, variables associated with VF were age, unemployment and use of a boosted protease inhibitor-based regimen versus nonnucleoside reverse transcriptase inhibitors. Despite the use of more potent and safer drugs in the last 10 years, and even in a universal health care setting, migrants living with HIV still present barriers to initiating ART and an increased risk of VF compared to natives.

Alternative N precursors and Mg doped GaN grown by MOVPE

In this paper, we address two different aspects relevant to the growth of GaN. The first part concerns alternative nitrogen source whereas in the second part, we report experimental results on Mg doping. Several nitrogen precursors have been used for the growth of GaN in MOVPE. To produce active species from N2 or NH3, a remote Plasma Enhanced Chemical Vapour Deposition (RPECVD) process has been implemented. In addition, nitrogen organic precursors, triethylamine and t-butylamine were also used. To accurately control the critical parameters of the MOVPE of GaN, we have implemented a laser reflectometry, which allows a real time in situ monitoring of the different steps of the growth. MeCp2Mg was used as Mg precursor for the p doping study. The dependence on the partial pressure of Mg precursor of dopant incorporation, electrical activity and growth rate are reported.

Yellow Band and Deep levels in Undoped MOVPE GaN

Undoped layers of GaN grown by MOVPE on sapphire substrates have been characterized by photoluminescence, photocapacitance and photoinduced current transient spectroscopy (PICTS). Photocapacitance reveals in all samples two specific signatures at photon energies of 1 eV and 2.5 eV. The photocapacitance decrease observed at 1 eV seems to be due to an electron capture process from the valence band, whereas the capacitance increase at 2.5 eV is related to an electron emission process. The fact that the capacitance step at 1 eV is only seen after photoionization at energies above 2.5 eV, and the observed correlation between its amplitude and the photoluminescence intensity of the “yellow band”, lead us to conclude that both transitions are linked to the same trap, which is also suggested to be responsible for the yellow band. The position of this trap, at 2.5 eV below the conduction band, is confirmed by PICTS measurements, that show a hole thermal emission activation energy of 0.9 eV at 350 K.

p-doping of GaN by MOVPE

Mg has been widely used as p-doping species despite its intrinsic difficulties. It is nowadays well established that during the growth process of Mg doped GaN, atomic H is generated from the decomposition of NH3 and Mg-H complexes are formed in the layer. This has been for instance shown by the occurrence of LO mode in IR absorption, and by the observation of the Mg-H local vibration modes. This H passivation limits the electrical activity of Mg, therefore an activation process is required to get full activation of the Mg atoms. In the present study, bismethylcyclopentadienyl magnesium [(MeCp)2Mg] was used as precursor. However, this precursor reacts in the gas phase with NH3 to produce tiny solid particles as evidenced by a very bright diffuse emission visible along the laser beam used for reflectometry measurements. This simplest obvious product would be [(MeCp)Mg(NH2)]m(m≥2). To limit this drawback, Ga and Mg precursor lines have been separated. With proper in situ heat treatment, doping densities up to 1.5×1018 cm−3 have been obtained. PL spectra of lightly Mg doped samples (1016 cm−3) are dominated by shallow donor-acceptor pairs whereas for higher doping densities ( 1018 cm−3), the luminescence is dominated by a broad band in the 2.7-2.9 eV range. GaN LEDs were fabricated from Si doped (n-type) and Mg-doped (p-type) GaN, these LEDs emit in the blue-UV range.

Antiretroviral treatment-based cost saving interventions may offset expenses for new patients and earlier treatment start

OBJECTIVES

Combination antiretroviral therapy (cART) has become the main driver of total costs of caring for persons living with HIV (PLHIV). The present study estimated the short/medium-term cost trends in response to the recent evolution of national guidelines and regional therapeutic protocols for cART in Italy.

METHODS

We developed a deterministic mathematical model that was calibrated using epidemic data for Lazio, a region located in central Italy with about six million inhabitants.

RESULTS

In the Base Case Scenario, the estimated number of PLHIV in the Lazio region increased over the period 2012-2016 from 14 414 to 17 179. Over the same period, the average projected annual cost for treating the HIV-infected population was €147.0 million. An earlier cART initiation resulted in a rise of 2.3% in the average estimated annual cost, whereas an increase from 27% to 50% in the proportion of naïve subjects starting cART with a nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen resulted in a reduction of 0.3%. Simplification strategies based on NNRTIs co-formulated in a single tablet regimen and protease inhibitor/ritonavir-boosted monotherapy produced an overall reduction in average annual costs of 1.5%. A further average saving of 3.3% resulted from the introduction of generic antiretroviral drugs.

CONCLUSIONS

In the medium term, cost saving interventions could finance the increase in costs resulting from the inertial growth in the number of patients requiring treatment and from the earlier treatment initiation recommended in recent guidelines.

Effect of suppressing HIV viremia on the HIV progression of patients undergoing a genotype resistance test after treatment failure

BACKGROUND

Treatment guidelines for multi-experienced HIV patients have recently evolved from aiming to preserve immunity to achieving virological success, largely due to the availability of new antiretroviral drugs and drug classes. To assess the role of viral suppression on clinical progression following a genotypic resistance test (GRT), we have examined a database on patients failing to respond to combined antiretroviral therapy (cART).

METHODS

Patients undergoing a GRT after failure to respond to cART between January 1999 and May 2006 were followed up to December 2006. Time-to-death or a new AIDS event/death were considered to be analysis end-points. Viral suppression (< 50 copies/ml [c/ml]) after GRT, a time-dependent covariate, was tested as predictor of disease progression.

RESULTS

Overall, 1,389 patients were included in this observational study. After the GRT, patients were followed up to 72 months (median 28 months, IQ range 13-51 months). During the follow-up, 124 patients (9%) died, and 86 (6%) experienced a new AIDS event. 774 patients (56%) achieved < 50 c/ml HIV-RNA. The results of an adjusted Cox model showed that undetectable HIV-RNA after the GRT was significantly associated with a lower risk of death (hazard ration [HR] 0.46, 95% confidence interval [CI] 0.27-0.76) and AIDS/death (HR 0.43, 95% CI 0.28-0.65). The adjusted hazard ratios suggested a twofold risk reduction. A threefold risk reduction of death related to achieved undetectable viral load was found in patients with resistance to more than one drug class and with CDC-C diagnosis; a fourfold reduction was found in patients with < 200 CD4+/mm(3).

CONCLUSIONS

Maximal viral suppression has a large impact on HIV progression, particularly in heavily pre-treated individuals. Our findings support the latest treatment guidelines, which have rapidly evolved from an initial lack of indication to suggestions, and finally to strong recommendations for achieving the goal of suppressing viremia.

Probiotics: from research to consumer

Intestinal microflora has metabolic, trophic and protective functions, and can be modified in pathological conditions and by the exogenous administration of probiotics. Probiotics are defined as living microorganisms which resist gastric, bile, and pancreatic secretions, attach to epithelial cells and colonize the human intestine. In the last twenty years research has been focused on the identification of the role of planktonic flora and adhesive bacteria in health and disease, and on the requisite of bacterial strains to become probiotic product which can be marketed. Probiotics can be commercialized either as nutritional supplements, pharmaceuticals or foods, but the marketing as a pharmaceutical product requires significant time, complex and costly research, and the demonstration of a well-defined therapeutic target. This review examines the sequential steps of research which, from the identification of a possible probiotic strain, lead to its production and marketing, summarizing the whole process existing behind its development, through its growth in laboratory, the studies performed to test its resistance to human secretions and stability, microencapsulation technologies, and safety tests.

Age-dependent MRI-detected lesions at early stages of transient global ischemia in rat brain

Although ischemic stroke has higher incidence and severity in aged than in young humans, the age factor is generally neglected in ischemia animal models. This study was aimed at comparing age-dependent effects at early stages of transient global cerebral ischemia (TGCI) in rats. TGCI was induced in two groups of rats (3-6 and 20-24 months old, respectively) by exposure to 15% oxygen and 15 min occlusion of the two common carotid arteries. Brains were analysed in vivo by MRI-apparent diffusion coefficient (ADC) and T2 maps--at 1-3 h post-TGCI and in vitro by histochemical examination of triphenyltetrazolium chloride (TTC)-stained slices. At 1-3 h post-TGCI, a higher incidence of lesions was found in aged than in young rats especially in the hippocampus and cortex (occipital plus parietal) but not in the thalamus. The lesioned regions showed lower ADC values in aged than in younger rats. The most substantial ADC decreases were associated with enhanced spin-spin relaxation and lower TTC staining. The different responses of the two age groups support the use of aged animals for investigations on different ischemia models. Our model of brain ischemia appears appropriate for further studies including drug effects.

[Giant-cell reaction in the breast after fine-needle aspiration]

We report two cases in which fine needle aspiration (FNA) in the breast generated changes histologically mimicking malignant lesions. In both cases a population of giant cells was present; the cells were osteoclast-like in the first case and 'atypical' multinucleated stromal giant cells in the second. The underlying lesion was pseudoangiomatous stromal hyperplasia (PASH) in both cases. The reactive nature was confirmed by retracing the needle tract and by the uneventful follow-up of 7 or 2 years, respectively. We propose that giant cell reaction be included in the list of FNA-generated changes.

Small cell neuroendocrine carcinoma with skeletal muscle differentiation: report of three cases

Three cases of neuroendocrine carcinoma showing skeletal muscle differentiation are presented. The tumors were located in the skin and subcutaneous tissue, the urinary bladder, and the nasal cavity respectively, and were composed by two cell types admixed intimately with each other. One cell type had features identical to those seen in conventional small cell neuroendocrine carcinoma, including scanty cytoplasm, round nuclei with fine granular chromatin, immunohistochemical reactivity for neuron-specific enolase, chromogranin and cytokeratins, and electron-dense granules on ultrastructural examination. The second cell type was either plasmacytoid or elongated and straplike, with abundant eosinophilic cytoplasm and irregular nuclei with prominent nucleoli. These cells showed immunohistochemical positivity for desmin, sarcomeric actin, myoglobin, and myogenin. They also exhibited ultrastructural evidence of rhabdomyoblastic differentiation in the form of contractile filaments with abortive Z-band formation. An origin from a cell capable of dual differentiation toward neuroendocrine and rhabdomyoblastic elements is postulated for these tumors.

Metabotropic glutamate receptors and brain ischemia: differential effects on phospoinositide turnover in young and aged rats

Neuronal damage and phosphoinositide hydrolysis stimulated by neurotransmitter receptor agonists in cerebral cortex of 3- and 24-month Fischer 344 rats, following an episode of brain ischemia, were compared. Transient global ischemia was induced by occlusion of common carotid arteries for 15 minutes in conditions of moderate hypoxia. Seven days after, histological examination of cerebral cortex showed cell loss, neurons with nuclear pyknosis, cytoplasmatic degeneration, and glial proliferation. Ischemic lesions appeared moderate to severe in young rats and intermediate in all the aged animals. In young rats inositol phosphates accumulation stimulated by excitatory amino acids (ACPD, ibotenate and quisqualate), but not by norepinephrine or carbachol, was enhanced significantly with respect to sham-operated animals. No potentiation at all was observed in aged rats. This finding suggests that the events leading to the increased metabotropic response in the post-ischemia period is impaired by the ageing process.

Influence of urethane and ketamine on rat hepatic cytochrome P450 in vivo

The aim of this study was to identify the effects of widely used laboratory anaesthetics on cytochrome (CYP) activity in male Sprague Dawley rats in vivo. The anaesthetics used were urethane and ketamine. 7-Ethoxyresorufin (EROD), 7-pentoxyresorufin (PROD), aniline and ethylmorphine were used as substrates for CYP 1A, CYP 2B, CYP 2E1 and CYP 3A, respectively. Urethane increased EROD (CYP 1A) activity by 40 % (p < 0.01), and hydroxylation of aniline (CYP 2E1) by 14 % in the early phase of anaesthesia and by 60 % (p < 0.01) in the later one. Urethane also reduced the demethylation of ethylmorphine by 37 % (p < 0.01), but did not affect CYP 2B activity significantly. Ketamine did not significantly affect CYP 1A, 2B or 2E1. However, it reduced the demethylation of ethylmorphine (i.e. CYP 3A) by 32 % (p < 0.01). From these data, we concluded that a single dose of urethane inhibits CYP 3A but increases CYP 2E1 and CYP 1A, and that a single dose of ketamine inhibits the activity of CYP 3A.

Transient global brain ischemia in young and aged rats: differences in severity and progression, but not localisation, of lesions evaluated by magnetic resonance imaging

A model of transient global brain ischemia consisting of bilateral occlusion of common carotid arteries for 10 min and mild hypoxia (15% O2-85% N2) for 20 min was studied by means of MRI in young and aged Fischer 344 rats (3-4 and 24-26 months, respectively). Ischemia was assessed by full suppression of spontaneous EEG activity, which reappeared and normalized similarly in the two age-groups. The survival of young with respect to aged rats was considerably higher both at 24 h (20/20, i.e. 100% vs 12/16, i.e. 75%) and at 48 h (16/20, i.e. 80% vs 6/16, i.e. 38%). The localisation of brain lesions, their severity and progression were evaluated by a diffusion-weighted MRI (DWI) sequence at 24 and 48 h post-ischemia. There were no DWI-detectable lesions in eight out of 20 young and two out of 12 aged rats. The localisation of DWI-detected lesions was rather similar in rats of the two age-groups. In fact, the cerebral cortex, mainly parietal, occipital and temporal lobes were damaged in 83% of young and 90% of aged rats. The respective percentages for the thalamus were 83 and 60%, for the striatum 58 and 50%, and for the hippocampus 25 and 30%. The lesions present in the cerebral cortex and the thalamus were considerably more severe in aged than in young rats. In conclusion, in spite of similar localisation of ischemic lesions in the two age-groups, their incidence was higher, appearance more rapid and severity more pronounced in aged with respect to young rats. This resulted in a considerably higher mortality of the former. The overall data indicate that the age issue is very important in experimental ischemia research.

Transient global brain hypoxia-ischemia in adult rats: neuronal damage, glial proliferation, and alterations in inositol phospholipid hydrolysis

A model of ischemic-hypoxic brain injury which combines bilateral occlusion of common carotid arteries for 10 min and mild hypoxia (15% O2 for 10 min before and during occlusion) was developed. Global ischemia was assessed by a simplified EEG recording indicating isoelectric line, i.e. full arrest of cortical electrical activity. Histological examination of brain 7 days after ischemic insult showed from moderate to severe damage, mainly in the cerebral cortex (layers III, V and VI) and hippocampus (mainly CA1 subfield). The injury consisted of neuronal degeneration and necrosis with nuclear pyknosis and karyorrhexis. Immunohistochemical staining for gliofibrillar acidic protein showed a marked glial proliferation in the cerebral cortex and hippocampus. In the cortical slices, inositol phosphates accumulation stimulated by excitatory amino acid agonists (ACPD, ibotenate and quisqualate), as well as by norepinephrine and carbachol, was enhanced significantly (p < 0.01) with respect to sham-operated rats 7 days, but not 24 h, after the ischemic insult. The overall data show that the relatively simple transient brain hypoxia/ischemia rat model produces full arrest of cortical EEG, histopathological alterations and those relative to post-receptor neurochemical mechanisms characteristic of four-vessel occlusion model.

Transient global brain ischemia in the rat: spatial distribution, extension, and evolution of lesions evaluated by magnetic resonance imaging

A newly developed model of transient global ischemia in the rat was evaluated by magnetic resonance imaging (MRI) in terms of localization of brain lesions, their extent and severity, and temporal evolution. Such a model, consisting of bilateral occlusion of common carotid arteries for 10 minutes and mild hypoxia (15% O2) for 20 minutes induces delayed neuronal degeneration, necrosis, and gliosis (detected histologically and immunohistochemically). Ischemia was assessed by full suppression of spontaneous electroencephalographic activity. A "hybrid" T2-/diffusion-weighted MR sequence enhancing more effectively the contrast between injured and intact tissues as compared to T2-weighted MRI was used at 24, 48, 72, and 96 hours and at 7 days postischemia. Twenty hypoxic-ischemic rats showed a considerable variability in brain damage. In 8, there were no MRI-detectable lesions at any interval. In the other 12 rats, the severity and extension of neuronal damage varied markedly, but the lesions were always localized (monolaterally in 8 and bilaterally in 4 rats) in the occipital, temporal, or parietal cerebral cortex. Mainly, they were of intermediate severity or were severe (as assessed by MRI hyperintensity) and were accompanied by usually less severe lesions in the thalamus and/or caudate putamen. The hippocampus was affected moderately or severely in 4 of 12 rats. In most cases, there was at 48 hours a considerable growth in severity and/or extension of lesions, which usually remained stable at later intervals. In conclusion, MRI allowed us to follow brain lesions during the first week in this relatively simple and noninvasive model of transient global ischemia.

[Dirofilaria (Nochtiella) repens in the spermatic cord: a new human case in Italy]

A case of human dirofilariasis associated with Dirofilaria (Nochtiella) repens, localised in the spermatic duct, is reported in a 52-year-old man from Lugo di Romagna (Ravenna province, Northern Italy). It represents the 22nd case of human dirofilariasis occurring until now in the same region. According to the relevant world literature this appears to be the 2nd case with this rare localisation the first one occurring in Italy as well.

Ubiquitin-mediated stress response in a rat model of brain transient ischemia/hypoxia

Ubiquitin (Ub) is a small 76-residue protein, involved in intracellular protein degradation through a specific ATP-dependent system, which uses Ub as a tag to label proteins committed to be hydrolyzed by a specific 26 S protease. PGP-9.5 is another important component of the Ub system, i.e. a neuron-specific carboxyl-terminal hydrolase, which recycles Ub from Ub-polypeptide complexes. We have investigated the expression of Ub and PGP-9.5 in rat hippocampal neurons in an early phase of reperfusion in a model of transient global brain ischemia/hypoxia (bilateral occlusion of common carotid arteries for 10 min accompanied by mild hypoxia-15% O2-for 20 min), by means of immunohistochemical methods using light and electron microscopy. The intensity of Ub and PGP-9.5 immunoreactivity was evaluated by image analysis. We have detected a marked increase of Ub immunoreactivity (UIR) in neurons of CA1, CA2, CA3, CA4, and dentate gyrus subfields 1 hr after ischemia/hypoxia (but not after hypoxia only), statistically significant as confirmed by image analysis. Such increase in immunoreactivity in ischemic/hypoxic rats was localized essentially in the nuclei of hippocampal neurons. There were no changes in PGP-9.5 immunoreactivity. The data suggest that in the present model of rat brain ischemia/hypoxia Ub is involved in the neuronal stress response.

Influences of hypothyroidism on lipid composition and inositol lipid-linked receptors responsiveness and protein kinase C (PKC) activity in the cerebral cortex of Lewis rats

The influence of hypothyroidism (HO) induced by treatment with propylthiouracil on lipid composition, receptor responsiveness of M1-muscarinic receptors (M1AChRs) and metabotropic glutamate receptors (mGluRs) as well as on protein kinase C (PKC) activity was investigated in the cerebral cortex of Lewis rats. HO did not influence the lipid composition. There was a significant 2-fold increase of efficacy and 6-fold decrease of potency of carbachol-induced inositol phosphate (IP) accumulation in HO, with respect to control rats. The efficacy of trans-(1S,3R)-1-amino-1,3-cyclopentanedicarboxylic acid (ACPD)-induced IP accumulation was also higher in HO (by 50%), without differences in EC50 values. The activities of soluble calcium-dependent and calcium-independent PKC were higher in HO than in control rats (both roughly 30%); membrane-associated PKCs were not modified. The data indicate that HO induces an increased responsiveness of M1AChRs and mGluRs and a rise in the soluble PKC activity that could be available and ready for translocation.

Differential responsiveness of metabotropic glutamate receptors coupled to phosphoinositide hydrolysis to agonists in various brain areas of the adult rat

The effects of metabotropic glutamate receptor (mGluR) agonists on inositol phosphates (IP) accumulation were investigated in slices of the cerebral cortex, hippocampus, striatum and cerebellum of adult Sprague-Dawley rats. EC(50) values for 1S, 3R-1-aminocyclopentane-1, 3-dicarboxylic acid (ACPD) did not differ significantly between various brain areas (range 10(-5) M), quisqualate was the most potent in all the brain areas (range 10(-7) - 10(-6) M), except the cerebellum (10(-5) M), ibotenate was the most potent in the striatum (range 10(-6) M) and the least potent in the cerebral cortex and hippocampus (range 10(-4) M). The efficacy in the four brain areas showed the following trend of ranking order for ACPD and quisqualate: hippocampus > striatum > cerebral cortex > cerebellum, and for ibotenate: hippocampus > cerebral cortex > striatum > cerebellum, although the observed differences reached the level of statistical significance only in the case of ACPD (hippocampus and striatum vs cerebellum) and ibotenate (hippocampus vs cerebellum). Co-incubation of the agonists at maximally effective concentrations in any pairwise combination resulted in no substantial additivity of IP accumulation. D,L-1-amino-3-phosphonopropionic acid (AP3) and D,L-2-amino-4-phosphonobutyric acid (AP4) at 0.5 mM concentration antagonized ACPD-induced IP accumulation by about 70 and 45 percent, respectively, without differences between brain areas. On the other hand, the antagonistic effects of L-serine-o-phosphate (SOP) at 1 mM concentration were the highest in the hippocampus (75 percent) and the lowest in the cerebellum (25 percent). The comparative data indicate considerable regional receptor heterogeneity, in terms of different ratios of response to the agonists (but not antagonists, except SOP). There is a robust responsiveness of mGluRs not only in the hippocampus and cerebral cortex, but also in the striatum which exhibits the highest affinity to both quisqualate and ibotenate.

Glutamate-dependent mechanisms in the induction of a calcium long-term potentiation-like phenomenon

The electric synaptic efficacy, in terms of extracellular electrical potentials, and the intracellular postsynaptic efficacy, in terms of inositol phosphate (IP) accumulation, were evaluated in rat hippocampal slices exposed for a brief period (10 min) to a high concentration of calcium (+2.7 mM). In addition, the effects of N-methyl-D-asparate (NMDA) ionotropic and metabotropic glutamate receptor (mGluR) antagonists on the induction and the establishment or maintenance of enhanced synaptic efficacy of CA1 pyramidal neurons due to high-calcium exposure were also tested. Elevation of the calcium concentration from 1.3-4 mM in the medium bathing hippocampal slices produced a long-lasting (80 over 90 min) increase in the slope of the CA1 somatic excitatory postsynaptic potential and the amplitude of the population spike (PS). Slice perfusion with NMDA antagonists cyclazocine and cis-4-phosphonomethyl-2-piperidine-carboxylic acid (CGS 19755) or with mGluR antagonists L-2-amino-3-phosphonopropionic acid (AP3) or alpha-methyl-4-carboxyphenyl-glycine (all 0.1 mM), during the 10-min period of exposure to high-calcium prevented the induction of such changes. By contrast, slice perfusion with the same concentration of CGS 19755 or L-AP3 did not affect the already established long-lasting increase in amplitude of CA1 PS induced by high-calcium. Moreover, high-calcium failed to produce any significant modification of the basal IP accumulation or of the IP accumulation elicited by mGluR agonist 1S,3R-trans-amino cyclo-pentane-1,3-dicarboxylic acid (ACPD). In conclusion, the results confirm that high-calcium induces a long-lasting increase in synaptic efficacy in rat hippocampal slices. Both NMDA ionotropic and mGluR receptors are involved in the induction, but not in the maintenance, of this phenomenon. In line with these data no modifications of basal or ACPD-induced phosphoinositide hydrolysis have been found during the maintenance stage.

Antinociceptive action of opiates and opioid peptides after unilateral microinjection into area tempestas in rats

Area tempestas (AT) is a forebrain area involved in the genesis and generalization of clonic convulsions in rats. This study reports that upon AT application opiates and opioid peptides produce antinociceptive effects as measured with the hot-plate (HP) and tail-flick (TF) tests in rats. Unilateral infusion of mu and kappa agonists into AT at doses in the nanogram range delayed the latency to respond for the contralateral paws in the HP test (Emax, 67-91 degrees of analgesia), beginning 1 to 5 min after application. A smaller effect was observed after the Leu-enkephalin, [D-Ala2,D-Leu5][enkephalin and D-Pen2,D-Pen5]enkephalin. No effect was observed after Met-enkephalin. In the TF test, unilateral application of mu and kappa agonists in the nanogram range produced antinociception with Emax values of 43 to 62 degrees of analgesia, beginning 5 to 15 min after infusion. No significant effect was found after unilateral infusion of delta agonists. Infusion into AT (10 min before) of naltrexone (2-4 ng), ICI 154, 129 (1-10 ng) and WIN 44,441-3 (2-20 ng) antagonized the antinociception evoked by locally applied morphine (25 ng), [D-Pen2,D-Pen5]enkephalin (50 ng) and U 50,488 (100 ng), respectively. In addition, antinociception induced by systemic morphine (2.5 mg/kg sc) was antagonized by subsequent (23 min) unilateral application of naltrexone (15 ng). In the HP test, a reduction of the antinociceptive effect of morphine was obtained for both ipsilateral and contralateral paws after the antagonists.(ABSTRACT TRUNCATED AT 250 WORDS)

Elastofibroma: an in vivo model of abnormal neoelastogenesis

Thirteen cases of elastofibroma have been studied by conventional light and electron microscopy, as well as by histochemistry and immunohistochemistry. By light microscopy elastinophilic material appeared as huge fibers crossing collagen bundles. Immunohistochemistry demonstrated a strong positivity for elastin in numerous and circumscribed areas of the extracellular matrix. By electron microscopy, collagen consisted of 40-50-nm wide fibrils, and elastin was made of large aggregates of moderately electron-dense material surrounding a very thin, apparently normal, elastin core. At high magnification these aggregates consisted of short tubules, often in regular arrays, surrounded by microfibrils and microfilaments. These data, associated with selective digestions on thin sections with elastase, purified collagenase, hyaluronidase, and chondroitinase ABC, revealed that elastic fibers in elastofibroma seem to be made of true elastin surrounded by an enormous amount of hydrophilic material, in which some elastin, chondroitin sulfates, and collagenase type-VII sensitive material are aggregated forming a rather ordered array of short tubules.

Primary intracranial lymphomas

We reviewed the cases of 16 patients with primary intracranial lymphomas. The clinical and radiological data proved to be helpful in suggesting the diagnosis, but only tumoral biopsy provided unequivocal diagnosis. In our cases radiotherapy proved to be the most effective treatment.

A comparison of methods for the detection of hepatitis B virus surface antigen (HBsAg)

Our aim was to check the relative sensitivity of the various commercial kits available on the Italian market for the detection of hepatitis B virus surface antigen (HBsAg) in its two subtypes ay and ad. To this end, panels from different producers were compared by parallel sensitivity assays of several kits. It was found that the kits revealed different sensitivities depending on the panel used, and that sensitivity curves were not parallel. Given the lack of uniformity of response in the various panels currently available, we preferred to use two panels prepared at the Istituto Superiore di Sanità, one for each of the aforementioned subtypes. These HBsAg serial-concentration preparations were used to measure the sensitivity of the different kits on the basis of distinct methodological principles, i.e. RIA, ELISA and RPHA. These are currently considered the most sensitive methodologies and are used for kits classified as belonging to the 3rd generation. For each kit we used the procedure indicated by its manufacturer as being the most sensitive. For some of the kits we adopted all procedures in parallel recommended by respective manufacturers for different conditions of use. Sensitivity was found to be a function of lot, kit, methodology and procedure used. For the RIA and ELISA kits, we also used a modified method in parallel with the normal procedures. This method consisted in presaturating the solid phase in a solution of bovine albumin serum and was generally shown to increase the sensitivity of the kit adopted. For the majority of the kits examined, as well as the direct tests, a confirmatory test was also used, i.e. a specific inhibition test to verify the positivity revealed. In this way an increase in the sensitivity of the sample was also obtained.

[Studies on iodine exchange in thermal therapy with salsobromoiodic water]

We have attempted a quantitative evaluation of the iodine taken in with the thermal waters from Salsomaggiore during therapeutic bathing, inhalation (dry and damp spray), or ingestion. For this purpose to 127I we have applied the metabolic parameters obtained through a 131I inhalation test and a 125I ingestion test. Of the iodine inhaled by aerosol 45% becomes exhaled; by 24 hours 2% is in the serum and in the extra-thyroid area of iodine distribution, 16% in the thyroid, 16% in the urine. By adding the amount of iodine exhaled to that found in the metabolic cycle of iodine, we find that about 21% of the inhaled iodine is still missing. This amount is trapped in the respiratory tract from where it disappears only very gradually. At the end of the 24 hours, therefore, in the metabolic cycle of the iodine we find 34% of that inhaled, whereas we find 87% of that ingested. The level of iodine in the serum reached in thermal therapeutic inhalation, never stays at a level which might alter the functioning of a normal thyroid. The amount of inhaled iodine which is excreted with the urine is usually eliminated during the first excretions. Experimental studies suggest that the iodine taken in during bathing in the thermal-pools mainly comes from iodine released from the water through the addition of hypochlorites, and is then inhaled through breathing the air just above the water.