Influence of Nitric Oxide-Cyclic GMP and Oxidative STRESS on Amyloid-ß Peptide Induced Decrease of Na,K-ATPase Activity in Rat Hippocampal Slices.

Amyloid-ß peptide (Aß) has been shown to cause synaptic dysfunction and can render neurons vulnerable to excitotoxicity and oxidative stress. Na,K-ATPase plays an important role to maintain cell ionic equilibrium and it can be modulated by N-methyl-D-aspartate (NMDA)-nitric oxide (NO)-cyclic GMP pathway. Disruption of NO synthase (NOS) activity and reactive oxygen species (ROS) production could lead to changes in Na,K-ATPase isoforms' activities that may be detrimental to the cells. Our aim was to evaluate the signaling pathways of Aß in relation to NMDA-NOS-cyclic GMP versus oxidative stress on α1-/α2,3-Na,K-ATPase activities in rat hippocampal slices. Aß1-40 induced a concentration-dependent increase of NOS activity and increased cyclic guanosine monophosphate (cGMP), TBARS (thiobarbituric acid reactive substances), and 3-Nitrotyrosine (3-NT)-modified protein levels in rat hippocampal slices. The increase in NOS activity and cyclic GMP levels induced by Aß1-40 was completely blocked by MK-801 (inhibitor of NMDA receptor) and L-NAME (inhibitor of NOS) pre-treatment but changes in TBARS levels were only partially blocked by both compounds. The Aß treatment also decreased Na,K-ATPase activity which was reverted by N-nitro-L-arginine methyl ester hydrochloride (L-NAME) but not by MK-801 pre-treatment. The decrease in enzyme activity induced by Aß was isoform-specific since only α1-Na,K-ATPase was affected. These findings suggest that the activation of NMDA-NOS signaling cascade linked to α2,3-Na,K-ATPase activity may mediate an adaptive, neuroprotective response to Aß in rat hippocampus.

Case report of gastrointestinal localization of SARS-CoV-2 and open abdomen technique in an Italian emergency surgery department for gastrointestinal bleeding.

This article aims to present the case of a man affected by SARS CoV-2 and to discuss the association between this manifestation, viral infection and Open Abodmen. A 52 years old Caucasian man, affected by SARS CoV-2 infection, was admitted to the Emergency department of Arcispedale Sant'Anna of Ferrara for epigastralgia followed by syncopal episode, vomiting and diarrhea with bloody stools. The next day the patient underwent colonoscopy, which detected an ulceration proximally to the ileocecal valve without active bleeding. Subsequently an initial non-operative management and two pharyngeal swabs negative, for another rectorrhagia and hypotensive episode, underwent emerging surgery and an Open Abdomen was performed. The patient was discharged in 12th post-surgery day without complications. The IHC analysis with anti-SARS-CoV-2 nucleocapsid-protein revealed the presence of viral protein expression in epithelial cell of ulcerated intestinal mucosa. In this case report, we showed the presence of viral inclusion in small intestinal wall after two negative pharyngeal swabs for SARS-CoV-2 RNA. We can also say that the largest amount of viral inclusions was in the tissue of ulceration of the last ileal loop. This case report showed that SARS-CoV-2 can be unseen also after clinical healing. It's probably can be expelled with stools and rectal swabs search for SARS-Cov-2 RNA after pharyngeal swabs could be mandatory for declare heled a patient. Moreover, damage control surgery and Open Abdomen as a surgical technique can be a valid alternative in case of uncertainty of the bleeding source and when a second surgical look is necessary.

Intermittent fasting uncovers and rescues cognitive phenotypes in PTEN neuronal haploinsufficient mice.

Phosphatase and tensin homolog (PTEN) is an important protein with key modulatory functions in cell growth and survival. PTEN is crucial during embryogenesis and plays a key role in the central nervous system (CNS), where it directly modulates neuronal development and synaptic plasticity. Loss of PTEN signaling function is associated with cognitive deficits and synaptic plasticity impairment. Accordingly, Pten mutations have a strong link with autism spectrum disorder. In this study, neuronal Pten haploinsufficient male mice were subjected to a long-term environmental intervention - intermittent fasting (IF) - and then evaluated for alterations in exploratory, anxiety and learning and memory behaviors. Although no significant effects on spatial memory were observed, mutant mice showed impaired contextual fear memory in the passive avoidance test - an outcome that was effectively rescued by IF. In this study, we demonstrated that IF modulation, in addition to its rescue of the memory deficit, was also required to uncover behavioral phenotypes otherwise hidden in this neuronal Pten haploinsufficiency model.

Acute necrotizing pancreatitis: can tigecycline be included in a therapeutic strategy?

INTRODUCTION: Acute necrotizing pancreatitis is a severe and life-threatening disease. Infection, which occurs in about 30% of cases, is the most feared complication. Antibiotic therapy is still discussed and there are no clear recommendation in literature. These clinical series underline the importance of having a clear antibiotic protocol, including tigecycline, in the management of acute necrotizing pancreatitis. Clinical series. Six patients with clinical and radiological diagnosis of necrotizing acute pancreatitis are treated in Emergency Surgery Department, following a conservative management, which includes fluid resuscitation, intensive care unit and radiological monitoring, ultrasound-guided percutaneous drainage and an antibiotic treatment protocol, that includes tigecycline. No one of the six patient undergo surgery (mean hospital stay: 44 days). In a six months follow-up all patients are alive and in good clinical conditions. DISCUSSION: Infection is the most important factor which determinate prognosis and outcome of acute necrotizing pancreatitis. Antibiotic prophylaxis is still discussed and there are no clear antibiotic treatment guidelines in literature. Despite its side effects on pancreatic gland, tigecycline is successful in resolution of sepsis, caused by infected pancreatic necrosis. CONCLUSIONS: Collaboration with infectivologist and a clear antibiotic protocol is fundamental to solve infected necrosis. Antibiotic treatment, set up as soon as possible, is successful in our six patients, as they recover without undergoing surgical procedures. Tigecycline offers broad coverage and efficacy against resistant pathogens for the treatment of documented pancreatic necrosis infection. However, further studies are necessary to fully understand the safety profile and efficacy of tigecycline.

4''-O-(omega-Quinolylamino-alkylamino)propionyl derivatives of selected macrolides with the activity against the key erythromycin resistant respiratory pathogens.

Four macrolides-6-O-methyl-8a-aza-8a-homoerythromycin, clarithromycin, azithromycin and azithromycin 11,12-cyclic carbonate, have been selected for the construction of a series of new quinolone derivatives. The quinolone moiety is connected to the macrolide scaffold via a diaminoaklyl 4''-O-propionyl ester chain of varying length. At the terminus the linker is attached via one of the nitrogen atoms in the linker at C(6) or C(7) of the quinolone. Many of compounds described, particularly clarithromycin derivative 37, and azithromycin derivatives 48 and 55, exhibited excellent antibacterial activity against a wide range of clinically relevant macrolide-resistant organisms, with profiles superior to that of telithromycin, an enhanced spectrum ketolide.

The squalestatins: decarboxy and 4-deoxy analogues as potent squalene synthase inhibitors.

Squalestatins without either the hydroxy group at C-4 or the carboxylic acid at C-3 or C-4 were prepared and evaluated for their ability to inhibit rat liver microsomal squalene synthase (SQS) in vitro. These modifications were well tolerated for compounds with the 4,6-dimethyloctenoate ester at C-6 (S1 series). However in analogues without the C-6 ester (H1 series), removal of the C-4 hydroxy group gave compounds with reduced potency, whereas decarboxylation at C-3 resulted in a dramatic loss of SQS inhibitory activity. In comparison with S1 1, C-4 deoxyS1 3 and C-3 decarboxyS1 10 have shorter in vivo durations of action on the inhibition of hepatic cholesterol biosynthesis in rats. C-4 deoxyS1 3 retains good serum cholesterol-lowering ability in marmosets, while C-3 decarboxyS1 10 showed only a marginal effect even at high dose.

Synthesis of novel 6-alpha and 6-beta-alkylcarbonylmethyl substituted penems.

6-alpha and 6-beta Alkylcarbonylmethyl penems were synthesized from 6-alpha-bromo and 6-oxo penicillanates respectively and their in vitro antibacterial activity was studied. The compounds were generally active against Gram-positive but not against Gram-negative strains, the compounds of the 6-beta series being more active. Relatively to imipenem, taken as reference compound, the penems resulted more stable towards chemical hydrolysis in Tris-HCl buffered medium (pH 7.4) but more sensitive towards dehydropeptidase-I (DHP-I).