The Colorectal Anastomosis: A Timeless Challenge.

Colorectal anastomosis is a sophisticated problem that demands an elaborate discussion and an elegant solution. "Those who forget the past are condemned to repeat it." George Santayana, Life of Reason , 1905.

Delayed onset of fatal encephalitis in a COVID-19 positive patient.

BACKGROUND: The SARS-nCoV-2019 epidemic has spread since December 2019, quickly gaining worldwide attention. Symptoms consist of fever, cough and breathing difficulties. An increasing number of studies are focusing on neurological manifestations. In addition to the typical ageusia and anosmia, up to 30% of cases can present headache, nausea and vomiting. More serious neurological manifestations, such as encephalitis, thrombosis and cerebral haemorrhage have been reported. CASE DESCRIPTION: We described the case of a 47-year-old man who tested positive for COVID-19 virus in early March 2020. After two negative nasopharyngeal swabs, 41 days after the diagnosis of COVID-19 infection, he developed intense headache with fever, and he was hospitalized. He had subsequent generalized epileptic seizures and intubation was necessary. Contrast Head MRI was negative for brain abscesses or tumours but detected severe vasogenic oedema of the white matter with 10 mm shift of the midline and compression of the right lateral ventricle. Massive cortisone support therapy was ineffective. We diagnosed brain death on day 43 from the infection diagnosis. DISCUSSION: COVID-19 virus can reach the brain, penetrating into the neuronal cells through the interaction between the spike protein S1 and the host ACE-2 receptor, expressed in the capillary endothelium. We believe that in this infection, the pro-inflammatory state induced by the cytokine storm can cause a cerebral cell-mediated response, with subsequent vasodilatation and brain oedema. CONCLUSION: To our knowledge, this is the first description of a delayed onset cell-mediated encephalitis caused by COVID-19 virus after more than 40 days from the diagnosis.

Identification of Highly Selective Orexin 1 Receptor Antagonists Driven by Structure-Based Design.

OX1 receptor antagonists are of interest to treat, for example, substance abuse disorders, personality disorders, eating disorders, or anxiety-related disorders. However, known dual OX1/OX2 receptor antagonists are not suitable due to their sleep-inducing effects; therefore, we were interested in identifying a highly OX1 selective antagonist with a sufficient window to OX2-mediated effects. Herein, we describe the design of highly selective OX1 receptor antagonists driven by the X-ray structure of OX1 with suvorexant, a dual OX1/OX2 receptor antagonist. Moderately selective OX1 antagonists comprising a [2.2.1]-bicyclic scaffold served as our starting point. Based on our binding mode hypothesis, we postulated which part of the scaffold points toward one of the regions where the two binding pockets differ. Structural changes in this part resulted in a modified core with higher inherent selectivity compared to the [2.2.1]-bicyclic template. The structure-based design, synthesis, and hit-to-lead evaluation of this novel OX1 receptor-selective scaffold are discussed herein.

Posttraumatic Vertebral Arteriovenous Fistula: A Lifeline from Tetraplegia?

BACKGROUND: Vertebral artery (VA) rupture is a rare condition that occurs about in 0.5% of cervical trauma. The management of our case was complicated by a spinal epidural hematoma (SEH) leading to worsening neurologic deficits. Only 1 similar case has been reported before in the literature. CASE DESCRIPTION: We report the case of a 37-year-old victim of a serious car accident. Shortly after admission to the emergency department, she developed weakness in all 4 limbs and sensory deficit below T6 level. Cervical spine computed tomography scan revealed an SEH from C1 to T3. Computed tomography angiography scan showed rupture of the left VA at C3 level, with a posttraumatic vertebral arteriovenous fistula at the same level, draining in the epidural venous plexus and to the right jugular internal vein. Immediately after embolization of the left VA, we performed a cervical decompression from C2 to C7. Three months after surgery the patient had a full recovery. CONCLUSIONS: No guidelines exist to treat this situation. We propose consequential steps to treat a posttraumatic cervical SEH with evidence of VA rupture.

Urological Injuries during Colorectal Surgery.

The proximity of the colon and rectum to the organs of the urologic system virtually ensures that iatrogenic urologic injuries become a distinct possibility during complex colorectal surgical procedures. An intimate knowledge of urogenital anatomy as well as strategies for identification and repair of potential injuries is of paramount importance. Attention is mandated when operating within the narrow confines of the pelvis, as this is where these structures are most at risk. The ureters are at highest risk of injury, followed by the bladder and urethra. The nature of these injuries encompasses both functional and mechanical morbidities. Patient factors, including prior pelvic surgery, radiation, inflammatory bowel disease, infectious processes, and urogenital abnormalities all increase the risk of injury. As colorectal surgeons encounter an increasing number of patients with the above risk factors, it is important to be familiar with the various urologic injury patterns, their diagnosis, and appropriate management.

Identification of Isoform 2 Acid-Sensing Ion Channel Inhibitors as Tool Compounds for Target Validation Studies in CNS.

Acid-sensing ion channels (ASICs) are a family of ion channels permeable to cations and largely responsible for the onset of acid-evoked ion currents both in neurons and in different types of cancer cells, thus representing a potential target for drug discovery. Owing to the limited attention ASIC2 has received so far, an exploratory program was initiated to identify ASIC2 inhibitors using diminazene, a known pan-ASIC inhibitor, as a chemical starting point for structural elaboration. The performed exploration enabled the identification of a novel series of ASIC2 inhibitors. In particular, compound 2u is a brain penetrant ASIC2 inhibitor endowed with an optimal pharmacokinetic profile. This compound may represent a useful tool to validate in animal models in vivo the role of ASIC2 in different neurodegenerative central nervous system pathologies.

Enantioselective Synthesis of the Cyclopiazonic Acid Family Using Sulfur Ylides.

A convergent, nine-step (LLS), enantioselective synthesis of α-cyclopiazonic acid and related natural products is reported. The route features a) an enantioselective aziridination of an imine with a chiral sulfur ylide; b) a bioinspired (3+2)-cycloaddition of the aziridine onto an alkene; and c) installation of the acetyltetramic acid by an unprecedented tandem carbonylative lactamization/N-O cleavage of a bromoisoxazole.

Discovery of BI-2545: A Novel Autotaxin Inhibitor That Significantly Reduces LPA Levels in Vivo.

In an effort to find new therapeutic interventions addressing the unmet medical need of patients with idiopathic pulmonary fibrosis, we initiated a program to identify new autotaxin (ATX) inhibitors. Starting from a recently published compound (PF-8380), we identified several highly potent ATX inhibitors with improved pharmacokinetic and safety profiles. Further optimization efforts resulted in the identification of a single-digit nanomolar lead compound (BI-2545) that shows substantial lowering of LPA in vivo and is therefore considered a valuable tool for further studies.

Neuroimaging of the Postoperative Spine.

Operative treatments of the spine are becoming increasingly more common for the availability of a wide range of surgical and minimally invasive procedures. MR imaging allows for excellent evaluation of both normal and abnormal findings in the postoperative spine. This article provides the basic tools to evaluate complications after different operative procedures and offers an overview on the main topics a radiologist may encounter during his or her professional carrier.

P2-quinazolinones and bis-macrocycles as new templates for next-generation hepatitis C virus NS3/4a protease inhibitors: discovery of MK-2748 and MK-6325.

With the goal of identifying inhibitors of hepatitis C virus (HCV) NS3/4a protease that are potent against a wide range of genotypes and clinically relevant mutant viruses, several subseries of macrocycles were investigated based on observations made during the discovery of MK-5172. Quinazolinone-containing macrocycles were identified as promising leads, and optimization for superior cross-genotype and mutant enzyme potency as well as rat liver and plasma concentrations following oral dosing, led to the development of MK-2748. Additional investigation of a series of bis-macrocycles containing a fused 18- and 15-membered ring system were also optimized for the same properties, leading to the discovery of MK-6325. Both compounds display the broad genotype and mutant potency necessary for clinical development as next-generation HCV NS3/4a protease inhibitors.

Disease activity in Graves' ophthalmopathy: diagnosis with orbital MR imaging and correlation with clinical score.

In Graves' ophthalmopathy (GO) it is important to distinguish acute inflammation at an early stage, responsive to immunosuppressive treatment, from inactive fibrotic end stage disease, unresponsive to the same treatment. The purpose of this study was to identify the most relevant signal intensities on orbital MR imaging with contrast administration both to classify patients according to their clinical activity score (defined by a cut-off value of 3) and to make a prediction of patient's CAS. Such threshold was considered as widely used in literature. Sixteen consecutive patients with a diagnosis of GO in different phases of thyroid disease based on clinical and orbital MR imaging signs, and six normal volunteers were examined. Orbital MR imaging was performed on a 1.5 Tesla MR Unit. MR scans were assessed by an experienced neuroradiologist, blinded to the clinical examinations. We found a statistical correlation between CAS and both STIR and contrast enhanced T1-weighted sequences. There was also a statistically significant correlation between STIR and contrast-enhanced T1 images disclosing the possibility of avoiding the injection of contrast medium. Our study proved that signal intensity values on STIR sequence increase in the inflammatory oedematous phase of disease. We confirmed the correlation between signal intensities on this sequence and CAS, showing an increase in signal intensity proportional to the CAS value. So we validated MRI use to establish the activity phase of disease more sensitively than CAS alone.

MK-5172, a selective inhibitor of hepatitis C virus NS3/4a protease with broad activity across genotypes and resistant variants.

HCV NS3/4a protease inhibitors are proven therapeutic agents against chronic hepatitis C virus infection, with boceprevir and telaprevir having recently received regulatory approval as add-on therapy to pegylated interferon/ribavirin for patients harboring genotype 1 infections. Overcoming antiviral resistance, broad genotype coverage, and a convenient dosing regimen are important attributes for future agents to be used in combinations without interferon. In this communication, we report the preclinical profile of MK-5172, a novel P2-P4 quinoxaline macrocyclic NS3/4a protease inhibitor currently in clinical development. The compound demonstrates subnanomolar activity against a broad enzyme panel encompassing major hepatitis C virus (HCV) genotypes as well as variants resistant to earlier protease inhibitors. In replicon selections, MK-5172 exerted high selective pressure, which yielded few resistant colonies. In both rat and dog, MK-5172 demonstrates good plasma and liver exposures, with 24-h liver levels suggestive of once-daily dosing. When administered to HCV-infected chimpanzees harboring chronic gt1a or gt1b infections, MK-5172 suppressed viral load between 4 to 5 logs at a dose of 1 mg/kg of body weight twice daily (b.i.d.) for 7 days. Based on its preclinical profile, MK-5172 is anticipated to be broadly active against multiple HCV genotypes and clinically important resistance variants and highly suited for incorporation into newer all-oral regimens.

Discovery of MK-5172, a Macrocyclic Hepatitis C Virus NS3/4a Protease Inhibitor.

A new class of HCV NS3/4a protease inhibitors containing a P2 to P4 macrocyclic constraint was designed using a molecular modeling-derived strategy. Building on the profile of previous clinical compounds and exploring the P2 and linker regions of the series allowed for optimization of broad genotype and mutant enzyme potency, cellular activity, and rat liver exposure following oral dosing. These studies led to the identification of clinical candidate 15 (MK-5172), which is active against genotype 1-3 NS3/4a and clinically relevant mutant enzymes and has good plasma exposure and excellent liver exposure in multiple species.

Discovery of (7R)-14-cyclohexyl-7-{[2-(dimethylamino)ethyl](methyl) amino}-7,8-dihydro-6H-indolo[1,2-e][1,5]benzoxazocine-11-carboxylic acid (MK-3281), a potent and orally bioavailable finger-loop inhibitor of the hepatitis C virus NS5B polymerase.

Infections caused by hepatitis C virus (HCV) are a significant world health problem for which novel therapies are in urgent demand. The polymerase of HCV is responsible for the replication of viral genome and has been a prime target for drug discovery efforts. Here, we report on the further development of tetracyclic indole inhibitors, binding to an allosteric site on the thumb domain. Structure-activity relationship (SAR) studies around an indolo-benzoxazocine scaffold led to the identification of compound 33 (MK-3281), an inhibitor with good potency in the HCV subgenomic replication assay and attractive molecular properties suitable for a clinical candidate. The compound caused a consistent decrease in viremia in vivo using the chimeric mouse model of HCV infection.

Development of 2-pyrrolidinyl-N-methyl pyrimidones as potent and orally bioavailable HIV integrase inhibitors.

A series of 2-pyrrolidinyl-N-methyl pyrimidones HIV integrase inhibitors has been explored leading to the identification of derivative 13, which showed high activity at inhibiting viral replication in cell culture, favorable pharmacokinetic profile in two preclinical species, and an attractive profile against a panel of HIV-integrase mutants.

Allosteric inhibitors of hepatitis C virus NS5B polymerase thumb domain site II: structure-based design and synthesis of new templates.

Chronic hepatitis C virus (HCV) infections are a significant medical problem worldwide. The NS5B Polymerase of HCV plays a central role in virus replication and is a prime target for the discovery of new treatment options. We recently disclosed 1H-benzo[de]isoquinoline-1,3(2H)-diones as allosteric inhibitors of NS5B Polymerase. Structural and SAR information guided us in the modification of the core structure leading to new templates with improved activity and toxicity/activity window.

[Feasibility of colorectal cancer screening with fecal occult blood test distributed by public pharmacies]. / Studio di fattibilità per lo screening del cancro del colon retto con sangue occulto fecale, mediante le farmacie comunali.

We conducted a colorectal cancer (CRC) screening program, in which public pharmacies provided the faecal occult blood test (FOBT), addressed to 50-70 years residents of 12th Municipality of Rome. A total of 5003 subjects were invited and 1103 (22.0%) performed the screening test, the adjusted compliance was 24.0%. Among 72 (6.5%) FOBT-positive subjects, 50 (69.5%) had colonoscopies; a CRC was detected in 5 subjects. Screening through the public pharmacies was feasible but the limited number of pharmacies enrolled have influenced compliance. A screening model that offers multiple providers (including private pharmacies) should be tested in order to improve screening compliance.

Selection of a palatable dietary option is not preferentially reduced by cannabinoid CB1 receptor antagonist AM251 in female C57Bl/6J mice.

We previously showed in female rats that administration of the cannabinoid CB1 receptor antagonist AM251 reduced energy intake by selectively decreasing consumption of a palatable dietary option in comparison to a standard maintenance chow. In the present study we sought to generalize these findings to mice. We presented 6 week old female C57Bl/6J mice with daily 8 h access to a sugar fat whip dietary option along with ad libitum access to moist chow. Mice were injected daily with either vehicle (equal parts polyethylene glycol and saline, 2 ml/kg) or one of three doses of AM251 (1, 3, or 10 mg/kg). Food intake and body weight were measured daily for 21 days. Although 8 h access to sugar fat whip did not induce overconsumption in female mice, AM251 reduced their energy intake and body weight in a dose-dependent manner. The decrease in energy intake occurred for both chow and sugar fat whip. This difference from results in rats suggests that the effect of AM251 on palatable food intake may only be evident in models that induce overconsumption and/or that rats and mice may react differently to CB1 receptor antagonists.

Inhibitors of the hepatitis C virus NS3 protease with basic amine functionality at the P3-amino acid N-terminus: discovery and optimization of a new series of P2-P4 macrocycles.

In a follow-up to our recent disclosure of P2-P4 macrocyclic inhibitors of the hepatitis C virus (HCV) NS3 protease (e.g., 1, Chart 1), we report a new but related compound series featuring a basic amine at the N-terminus of the P3-amino acid residue. Replacement of the electroneutral P3-amino acid capping group (which is a feature of almost all tripeptide-like inhibitors of NS3 reported to date) with a basic group is not only tolerated but can result in advantageous cell based potency. Optimization of this new class of P3-amine based inhibitors gave compounds such as 25 and 26 that combine excellent cell based activity with pharmacokinetic properties that are attractive for an antiviral targeting HCV.