Dacarbazine alone or associated with melanoma-bearing cancer pain model induces painful hypersensitivity by TRPA1 activation in mice

Antineoplastic therapy has been associated with pain syndrome development characterized by acute and chronic pain. The chemotherapeutic agent dacarbazine, used mainly to treat metastatic melanoma, is reported to cause painful symptoms, compromising patient quality of life. Evidence has proposed that transient receptor potential ankyrin 1 (TRPA1) plays a critical role in chemotherapy-induced pain syndrome. Here, we investigated whether dacarbazine causes painful hypersensitivity in naive or melanoma-bearing mice and the involvement of TRPA1 in these models. Mouse dorsal root ganglion (DRG) neurons and human TRPA1-transfected HEK293 (hTRPA1-HEK293) cells were used to evaluate the TRPA1-mediated calcium response evoked by dacarbazine. Mechanical and cold allodynia were evaluated after acute or repeated dacarbazine administration in naive mice or after inoculation of B16-F10 melanoma cells in C57BL/6 mice. TRPA1 involvement was investigated by using pharmacological and genetic tools (selective antagonist or antisense oligonucleotide treatment and Trpa1 knockout mice). Dacarbazine directly activated TRPA1 in hTRPA1-HEK293 cells and mouse DRG neurons and appears to sensitize TRPA1 indirectly by generating oxidative stress products. Moreover, dacarbazine caused mechanical and cold allodynia in naive but not Trpa1 knockout mice. Also, dacarbazine-induced nociception was reduced by the pharmacological TRPA1 blockade (antagonism), antioxidants, and by ablation of TRPA1 expression. TRPA1 pharmacological blockade also reduced dacarbazine-induced nociception in a tumor-associated pain model. Thus, dacarbazine causes nociception by TRPA1 activation, indicating that this receptor may represent a pharmacological target for treating chemotherapy-induced pain syndrome in cancer patients submitted to antineoplastic treatment with dacarbazine.     

Effects of capsaicin,tachykinins, calcitonin gene-related peptide and bradykinin in the pig iris sphincter muscle

Summary Capsaicin-sensitive sensory neurons of the rabbit iris, by releasing tachykinins, exert a major role in the control of pupil motility in response to various noxious stimuli. However, the contribution of sensory innervation to the regulation of iris smooth muscle tone in other mammals species is not known. We have studied the effects produced by electrical field stimulation, capsaicin, substance P, neurokinin A, calcitonin gene-related peptide (CGRP), and bradykinin in the isolated iris sphincter muscle of the pig.Capsaicin (10 M): a) contracted the isolated sphincter muscle and; b) released immunoreactivity for substance P (SP-LI) and CGRP (CGRP-LI) from this preparation. These two effects were no longer observed at the second exposure to the drug. Electrical field stimulation (10 Hz, 60 V, 0.5 ms for 5 s) produced a biphasic contractile response. The rapid component was inhibited by atropine (1 M), while the delayed response was blocked by previous exposure to capsaicin (10 M).Substance P and neurokinin A consistently produced contraction of the pig iris sphincter muscle, substance P being more potent than neurokinin A. CGRP induced a contractile response in more than 50% of the preparations. The tachykinin antagonist [D-Argl, D-Trp^7,9, Leu¹¹-substance P (3 M) blocked: a) the effect of substance P (1 nM); b) the delayed response to electrical field stimulation and; c) reduced by more than 50% response to capsaicin. Bradykinin (10 M) failed to release either SP-LI or CGRP-LI. The contractile response evoked by bradykinin was unaffected by in vitro pretreatment with capsaicin (10 M).The existence in the pig iris of capsaicin-sensitive sensory fibres releasing neuropeptides and thus regulating sphincter muscle tone is proposed. Send offprint requests to Dr. P. Geppetti at the above address     

Hydrogen sulfide inhibits human platelet aggregation

Gaseous mediators such as nitric oxide (NO) play a major regulatory role in the cardiovascular system homeostasis, including platelet aggregation. Here, we investigated whether hydrogen sulfide (H(2)S), a newly recognized endogenous mediator, can affects aggregation of human platelets, using sodium hydrogen sulfide (NaHS) as H(2)S-donor. NaHS inhibited platelet aggregation induced by ADP, collagen, epinephrine, arachidonic acid, thromboxane mimetic, U46619, and thrombin. H(2)S effect was not dependent by cAMP/cGMP generation, NO production or potassium-channels opening. NaHS concentrations (up to 10 mM) did not exert toxic effects on platelet viability. The possible protective role of endogenous H(2)S in cardiovascular system is discussed.     

Retrospective analysis in 46 women with vulvovaginal atrophy treated with ospemifene for 12 weeks: improvement in overactive bladder symptoms

Aims: The aim of this study was to assess the effectiveness and safety of ospemifene in the improvement of overactive bladder (OAB) symptoms in postmenopausal women affected by vulvovaginal atrophy (VVA).

Methods: Forty-six postmenopausal patients affected by VVA with OAB syndrome were enrolled for the study. All patients received Ospemifene 60?mg for 12?weeks. Clinical examination, 3-day voiding diary, urodynamic testing, ultrasound measurement of endometrial and bladder wall thickness (BWT) and the Vaginal Health Index (VHI) were performed at baseline and 12?weeks. Patients completed the OAB-Q SF and UDI-6.

Results: After 12-weeks, the number of patients with detrusor overactivity decreased from 39% to 13% (p?=?0.04). The reduction in the mean number in 24?h of voids (9.57?±?2.12 vs. 6.63?±?1.22, p?p?p?p?=?0.003) was observed. The UDI-6, OAB-Q symptoms, OAB-Q (HRQL) scores were 8.95?±?0.91 vs. 5.56?±?1.40, 62.60?±?14.70 vs. 20.08?±?10.83 and 18.71?±?7.41 vs. 79.45?±?14.47 (p?Conclusion: Ospemifene is an effective potential therapy for postmenopausal women with VVA improving OAB symptoms and quality of life.     

Pilocarpine-induced temporal lobe epilepsy in the rat is associated with increased dopamine neuron activity

Temporal lobe epilepsy (TLE) is defined as the occurrence of spontaneous seizures that involve the limbic system, with the hippocampal formation and associated structures being central to the most prevalent refractory form of adult focal epilepsy. TLE is often associated with psychotic features resembling the hallucinations and delusions that occur with schizophrenia. Given evidence that the ventral hippocampus plays an important role in the maintenance of temporal lobe seizures, we investigated whether an animal model of TLE using intrahippocampal injection of pilocarpine induces alterations in mesolimbic dopamine neuron activity. We found that in 60% of rats in which pilocarpine induced seizure activity, there was a significant increase in the number of dopamine neurons firing per electrode track. Furthermore, this occurred in concert with an increase in amphetamine-stimulated locomotor activity. Both observations are similar to those observed in a rodent developmental model of psychosis. Therefore, as in animal models of schizophrenia, TLE-associated psychosis is probably due to abnormal hippocampal overdrive of dopamine neuron activity.     

N-valproyl-L-tryptophan for CNS-targeting: synthesis, characterization and efficacy in vitro studies of a new potential antiepileptic drug

A new aminoacidic derivative of valproic acid (VPA) has been synthesized and characterized by analytical and spectral data. The rationale for the preparation of such potential antiepileptic agent is based on the observation that chemical combination of the anticonvulsant pharmacophore, VPA with essential aminoacids could afford more effective and less toxic actives. The synthesis, characterization, physico-chemical parameters functional for crossing Blood Brain Barrier of N-valproyl-L-tryptophan (4) are reported. The Log D (pH7.4) (0.3) indicates that (4) is adequate to cross biological membranes. Its chemical and enzymatic stability were assessed. The experiments indicate high stability of compound (4) at pH conditions of physiological fluids. Moreover, both in plasma and in cerebral enzymatic environments compound (4) doesn't undergo cleavage after 24 h. The anticonvulsant activity of the new compound was assessed against epileptic burst discharges evoked in vitro in rat hippocampal slices (Seizure like events - SLEs) and compared with that of the widely used VPA. Compound (4), even at the lower tested concentration, when compared to VPA, showed an improved protective effect against hippocampal seizures. The collected data suggest that compound (4) could be considered a very valuable candidate for subsequent in vivo evaluation as new potential antiepileptic drug.     

Serological diagnosis of Epstein-Barr virus infection: Problems and solutions

Serological tests for antibodies specific for Epstein-Barr virus (EBV) antigens are frequently used to define infection status and for the differential diagnosis of other pathogens responsible for mononucleosis syndrome. Using only three parameters [viral capsid antigen (VCA) IgG, VCA IgM and EBV nuclear antigen (EBNA)-1 IgG],it is normally possible to distinguish acute from past infection: the presence of VCA IgM and VCA IgG without EBNA-1 IgG indicates acute infection, whereas the presence of VCA IgG and EBNA-1 IgG without VCA IgM is typical of past infection. However, serological findings may sometimes be difficult to interpret as VCA IgG can be present without VCA IgM or EBNA-1 IgG in cases of acute or past infection, or all the three parameters may be detected simultaneously in the case of recent infection or during the course of reactivation. A profile of isolated EBNA-1 IgG may also create some doubts. In order to interpret these patterns correctly, it is necessary to determine IgG avidity, identify anti-EBV IgG and IgM antibodies by immunoblotting, and look for heterophile antibodies, anti-EA (D) antibodies or viral genome using molecular biology methods. These tests make it possible to define the status of the infection and solve any problems that may arise in routine laboratory practice.     

The ketogenic diet: from molecular mechanisms to clinical effects

Recent years have witnessed an increased interest from pediatric neurologists, neuropediatricians, epileptologists and general neurologists in the use of the ketogenic diet (KD) for the management of refractory epilepsies, particularly in children and adolescents. This article summarizes current knowledge on various issues related to its use, as discussed at a recent international workshop. Aspects discussed in some detail include (i) the putative mechanisms responsible for the diet's anticonvulsant effects,based on results of biochemical and neurophysiological studies in experimental models; (ii) consensus and controversies on the modalities of initiation of the diet, and different protocols of implementation; (iii) indications and contraindications; (iv) efficacy data, also in relation to seizure type, syndromic form and patients age; (v) adverse effects; (vi) methodological aspects related to assessment of the diet's clinical effects, and perspectives for future research. Overall, the data reviewed indicate that considerable advances have been made in understanding the modes of action of the diet, its efficacy and tolerability profiles and its potential role in different types of epilepsy. Although clinical studies performed to date have important methodological limitations, including suboptimally characterized patients' populations and an uncontrolled design, a number of innovative, prospective randomized study protocols have been recently proposed and are being implemented. The results of these will hopefully provide much needed high-quality information to better define the role of the diet in the treatment algorithms in different epilepsy syndromes.     

Bedside diagnostic laparoscopy to diagnose intraabdominal pathology in the intensive care unit

Introduction

Delayed diagnosis of intraabdominal pathology in the intensive care unit (ICU) increases rates of morbidity and mortality. Intraabdominal pathologies are usually identified through presenting symptoms, clinical signs, and laboratory and radiological results; however, these could also delay diagnosis because of inconclusive laboratory tests or imaging results, or the inability to safely transfer a patient to the radiology room. In the current study we evaluated the safety and accuracy of bedside diagnostic laparoscopy to confirm the presence of intraabdominal pathology in an ICU setting.

Methods

This retrospective study, carried out between January 2006 and June 2008, evaluated the diagnostic accuracy of bedside diagnostic laparoscopy performed on patients with a suspicion of ongoing intraabdominal pathology. Clinical indications for bedside diagnostic laparoscopy were: ultrasonography (US) images of gallbladder distension or wall thickening of more than 3 to 4 mm, with or without pericholecystic fluid; elevation of laboratory tests (bilirubin, transaminases, myoglobin, lactate dehydrogenase, creatine phosphokinase, gamma-glutamyltransferase); high level of lactate/metabolic acidosis; CT images inconclusive for intraabdominal pathology; or inability to perform a CT scan. Patients did not undergo bedside diagnostic laparoscopy if they presented clear indications for open surgery, coagulopathy, abdominal wall infection or high intraabdominal pressure.

Results

Thirty-two patients underwent bedside diagnostic laparoscopy (Visiport Plus, Autosuture, US), 14 of whom had been admitted to the ICU for major trauma, 12 for sepsis of unknown origin and 6 for complications after cardiac surgery. The procedure was performed on an average of eight days after ICU admission (95% confidence interval = 5 to 15 days) and mean procedure duration was 40 minutes. None of the procedures resulted in complications. Bedside diagnostic laparoscopy was diagnostic for intraabdominal pathology in 15 patients, who subsequently underwent surgery, except in two cases of diffuse gut hypoperfusion. Diagnosis of cholecystitis was obtained in seven cases: two were treated with laparotomic cholecystectomy and five with percutaneous gallbladder drainage positioning.

Conclusions

Bedside diagnostic laparoscopy represents a safe and accurate technique for diagnosing intraabdominal pathology in an ICU setting and should be taken into consideration when patient transfer to radiology or the operating room is considered unsafe, or when routine radiological examinations are not conclusive enough to reach a definite diagnosis.     

Obstetric brachial plexus palsy: a population-based retrospective case-control study and medicolegal considerations

Aims: The aim of this study was to examine 24 cases of obstetric brachial plexus palsy (OBPP) in 41,002 deliveries occurred at San Camillo–Forlanini Hospital in Rome, during the period 2000–2012.

Materials and methods: A population-based retrospective case-control study was designed and the database of the hospital was searched; for each case, maternal and fetal records were examined and some risk factors were evaluated.

Results: A statistically significant association between the 24 cases OBPP and the following risk factors: primiparity (p?p?p?p?p?Conclusions: The absence of OBPP cases in cesarean deliveries highlighted in this study supports the option of proposing an elective cesarean in the presence of known risk factors after a full disclosure with the mother of risks and benefits in order to obtain a valid consent. Furthermore, when cases of OBPP occur, communication between the physician and the parents of newborns is crucial and it may represent a valid risk-management tool to reduce malpractice lawsuits.