Role of N-glycosylation on Zika virus E protein secretion, viral assembly and infectivity.

Zika virus has rapidly spread reaching a global distribution pattern similar to that of dengue virus, and has been associated with serious neurological and developmental pathologies, like congenital malformation during pregnancy and Guillain-Barré syndrome. Sequence analysis of different clinical and laboratory isolates has shown the existence of mutants with loss of the conserved N-glycosylation motif on domain I of protein E that is common to all flaviviruses. We found that loss of E N-linked glycosylation leads to compromised expression and secretion of E ectodomain from mammalian cells. For both, wild type and glycosylation-negative mutant, secretion was independent of co-expression of the PrM viral protein, but highly dependent on temperature. Low temperature (28 °C) favoured secretion, although the glycosylation mutant E ectodomain showed impaired secretion and membrane display compared to the wild type. Production of pseudoviral particles with a West Nile virus replicon packaged with the Zika virus structural proteins C-PrM-E was significantly reduced with the non-glycosylated E. Similarly, glycosylation-negative pseudoviral particles showed impaired infectivity of Vero cells and reduced ability to infect K562 cells upon particles opsonisation with anti-E antibodies.

An unusual case of mammary Paget’s disease in a woman with psoriasis.

Mammary Paget’s disease (MPD) is a malignant breast tumor, which is characterized by intraepidermal infiltration from malignant glandular epithelial cells. Often it may include an underlying ductal carcinoma in situ or an invasive ductal carcinoma. Clinically it appears as an erythematous patch, moist or crusted, with or without desquamation that in some cases becomes ulcerated, causing infiltration and inversion of the nipple. We report the clinical case of a 60-year-old woman, treated in our department for psoriasis, presenting with erythema of nipple and areola with nipple erosion, ulceration and poor secretion. Suspecting Paget’s disease of the nipple, radiological exams (mammography and breast MRI) were performed. A biopsy for histological examination was carried out and confirmed the diagnosis of mammary Paget’s disease. MPD is sometimes difficult to diagnose both clinically and radiologically, therefore it is important to distinguish from other conditions: in literature MPD is reported in differential diagnosis with psoriasis given its similar clinical features, and in some cases MPD has been treated with topical and systemic steroids due to a wrong diagnosis. However, the concomitance, in the same individual, of mammary Paget’s disease and psoriasis has never been described.

Secretion of dengue virus envelope protein ectodomain from mammalian cells is dependent on domain II serotype and affects the immune response upon DNA vaccination.

Dengue virus (DENV) is currently among the most important human pathogens and affects millions of people throughout the tropical and subtropical regions of the world. Although it has been a World Health Organization priority for several years, there is still no efficient vaccine available to prevent infection. The envelope glycoprotein (E), exposed on the surface on infective viral particles, is the main target of neutralizing antibodies. For this reason it has been used as the antigen of choice for vaccine development efforts. Here we show a detailed analysis of factors involved in the expression, secretion and folding of E ectodomain from all four DENV serotypes in mammalian cells, and how this affects their ability to induce neutralizing antibody responses in DNA-vaccinated mice. Proper folding of E domain II (DII) is essential for efficient E ectodomain secretion, with DIII playing a significant role in stabilizing soluble dimers. We also show that the level of protein secreted from transfected cells determines the strength and efficiency of antibody responses in the context of DNA vaccination and should be considered a pivotal feature for the development of E-based DNA vaccines against DENV.

RECTAL IMPACTION DUE TO PRICKLY PEAR SEEDS BEZOAR: A CASE REPORT.

Fecal impaction is the third cause of lower gastrointestinal tract obstruction after strictures for colon cancer and postoperative adhesions. A rapid diagnosis is necessary to avoid complications due to intestinal obstruction. Rectal phytobezoar due to prickly pear fruit seeds are an extremely rare entity, in the literature about twenty similar cases are described. Prickly pears are common in many countries, even in the Mediterranean area. When the ingestion of their fruit is excessive, this can be harmful, leading to the formation of phytobezoar causing fecal impaction. We describe the first case of phytobezoar due to prickly pear fruit seeds in continental Europe: a 76-year-old Italian female who ingested almost 40 prickly pear fruit leading to the composition of a large rectal phytobezoar. The patient presented clinically with fecal impaction, diagnosed by imaging and successfully treated by rectal irrigation and manual disimpaction. Our aim is to remind the physicians of these risks in evaluating patients with intestinal obstruction, when there is positive anamnesis for provenience from some areas in which these fruits are eaten. We also want to underline the role of Imaging Multi Detector Computed Tomography (MDCT) in the diagnosis of these very uncommon entities.

Short-term spatial and temporal variability in greenhouse gas fluxes in riparian zones.

Recent research indicates that riparian zones have the potential to contribute significant amounts of greenhouse gases (GHG: N2O, CO2, CH4) to the atmosphere. Yet, the short-term spatial and temporal variability in GHG emission in these systems is poorly understood. Using two transects of three static chambers at two North Carolina agricultural riparian zones (one restored, one unrestored), we show that estimates of the average GHG flux at the site scale can vary by one order of magnitude depending on whether the mean or the median is used as a measure of central tendency. Because the median tends to mute the effect of outlier points (hot spots and hot moments), we propose that both must be reported or that other more advanced spatial averaging techniques (e.g., kriging, area-weighted average) should be used to estimate GHG fluxes at the site scale. Results also indicate that short-term temporal variability in GHG fluxes (a few days) under seemingly constant temperature and hydrological conditions can be as large as spatial variability at the site scale, suggesting that the scientific community should rethink sampling protocols for GHG at the soil-atmosphere interface to include repeated measures over short periods of time at select chambers to estimate GHG emissions in the field. Although recent advances in technology provide tools to address these challenges, their cost is often too high for widespread implementation. Until technology improves, sampling design strategies will need to be carefully considered to balance cost, time, and spatial and temporal representativeness of measurements.

A rare case of myeloid sarcoma presenting as anal fissure.

Myeloid sarcoma is a tumor composed of myeloblasts occurring at an extramedullary site. It may develop in patients with acute myeloid leukemia, myeloproliferative or myelodysplastic syndrome, sometimes preceding onset of the systemic disease. Frequent sites of myeloid sarcoma are bones or various soft tissues. Gastrointestinal involvement is very rare. We report a unique case of myeloid sarcoma presenting as a painful anal fissure, in a patient with a history of acute myeloid leukemia. The diagnosis was achieved by a surgical excisional biopsy and immunoistochemical staining.

Surgical reconstructive procedures for treatment of ischial, sacral and trochanteric pressure ulcers.

BACKGROUND: Pressure ulcers are frequent complications for long term hospitalized bed-ridden patients which are not able to move or move very little. In fact, the lesion forms in a skin and muscle region which undergoes a constant pressure between an underlying bone protrusion and a support structure such as a bed or a wheelchair. Initially only the outer layers are involved but in time, the ulcer can spread to the deeper structures and reach the bone. PATIENTS AND METHODS: In our work we described the anatomical areas that are most often subject to developing a pressure ulcer and we considered the surgical treatment and reconstructive procedures which are applied using a logical and rigorous sequence. RESULTS: We considered 4 clinical cases (2 ischiatic sores, 1 sacral sore and 1 gluteal-trochanteric sore) which demonstrate the surgical treatment and the reconstructive procedures. CONCLUSIONS: It is crucial to cover the defects with a thick flap to give more support and protection to the areas which undergo pressure and to lower the incidence of recurrences.

Surgical drain after open or laparoscopic splenectomy: is it needed or contraindicated?

OBJECTIVE: The Authors report their experience with the routine use of surgical drainage in a large series of splenectomies. SUMMARY OF BACKGROUND DATA: Benefits and risks related to surgical drains have been always discussed, with some surgeons in favor of them and skeptic others considering not physiological their use. After splenectomy, their use is also largely debated, especially because of susceptibility of operated patients to infections. PATIENTS AND METHODS: Two thousand nine cases have been reviewed. Indications for splenectomy, performed either by open or laparoscopic approach, included idiopathic thrombocytopenic purpura in 137 patients (65,4%), splenic lymphoma in 36 (17,2%), hereditary spherocytosis in 15 (7,4%), ß-thalassemia in 8 (3,7%), other diseases in 13 (6,1%). RESULTS: "Active" or "passive" drains were placed in 80% and 20% of cases, respectively. Drains were removed 2-3 days after surgery in 90,2%, within 10 days in 4,3%, within 2 months in 0,4% of cases. In 2 cases a post-operative bleeding, detected through the drainage, required re-operation. One patient developed a subphrenic abscess, successfully treated by a percutaneous drainage. One case of pancreatic fistula was observed. CONCLUSIONS: In Authors' experience, the use of drains after splenectomy does not affect the risk of subsequent infectious complications, independently on the type of the drainage system used. Early removal of drains in this series might have played an important role in the very low incidence of abdominal infections reported. The use of surgical drains after splenectomy might play an important role to early detect post-operative bleeding, as it happened in 2 cases of this series.

Subcutaneous cervical emphysema and pneumomediastinum due to a diastatic rupture of the cecum.

Pneumomediastinum usually occurs after esophageal or chest trauma. Subcutaneous cervical emphysema as a presentation of non-traumatic colonic perforation following colorectal cancer or diverticulitis, is very rare. We report a case of a patient with rectal cancer who developed a diastatic cecum retroperitoneal perforation with a secondary pneumomediastinum and cervical emphysema. The patient was in treatment with a neoadjuvant chemo-radiotherapy for a low rectal cancer. Treatment consisted in an emergency right hemi-colectomy with ileostomy and performance of distal colonic fistula. The Authors discuss the occurrence of pneumomediastinum and cervical emphysema complicating rectal cancer, pointing out ethiopathogenesis, clinical presentation, diagnosis and treatment. The importance of performing a diverting colostomy when neoadjuvant chemotherapy is scheduled in patients with stenotic rectal cancer, although not clinically occluded.

Laparoscopic-endoscopic rendez-vous resection of iuxta-cardial gastric GIST.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract and they often require a surgical removal. Gastrointestinal stromal tumors can originate from any part of the gastrointestinal tract but gastric location is the most common. In the past the risk of rupture of pseudocapsula and peritoneal dissemination have discouraged surgeons from making a minimally invasive surgical treatment. Recently laparoscopic wedge resection has been proposed. Performance of this mini-invasive technique is however difficult in some gastric location of gastrointestinal stromal tumors, such as iuxta-cardial region. The Authors report and discuss a new technique they used to remove a gastrointestinal stromal tumor located just below the cardia, using a rendez-vous endoscopic and laparoscopic technique.

Laparoscopic treatment of mucinous adenocarcinoma of jejunum associated with celiac disease. Case report.

Mucinous adenocarcinoma of the small bowel is very rare, and only few cases have been described in the literature. Association of this tumor with celiac disease has never been published. The authors report a unique case of jejunal mucinous adenocarcinoma in which a concomitant celiac disease has been histologically recognized. The difficult diagnosis, the role of laparoscopic surgery and the relationship between small bowel tumors and celiac disease are discussed. A 49-year-old man presented with recurrent melena, nausea, vomiting and anemia. A stenosis of the jejunum was documented by means of CT scan and video capsule enteroscopy. A laparoscopy was scheduled. A tumor, found in the first jejunal loop, was removed by laparoscopic surgery. Histopathology revealed a rare mucinous adenocarcinoma associated with epithelial changes secondary to celiac disease. Although small bowel tumors are rare entity, in patients with celiac disease complaining of symptoms related to altered intestinal transit or occult bleeding, an appropriate work-up should be planned for diagnosis. Mucinous type intestinal adenocarcinoma, even if never published before, could be observed. Laparoscopic surgery is often essential for the diagnosis and treatment.

Polyp of the cecum. Laparoscopic-assisted polypectomy.

The Authors discuss on a laparoscopic-assisted approach for excision of a sessile villous adenomatous polyp of the cecum, unresectable by endoscopy. Because of the large implant of the polyp, endoscopic polypectomy was considered at high risk and a surgical laparoscopic procedure was scheduled for removal of the lesion. After right colon mobilization, an intraoperative endoscopy confirmed the location of th polyp in the posterior wall of the cecum, closed to the ileo-cecal valve. A small 10 cm laparotomy, through which the cecum was pulled out the abdominal cavity, was performed. Then, a minimal colotomy along the intestinal taenia was carried out to allow a safe and complete excision of the polyp. This laparoscopic approach differs from the other laparoscopic-assisted methods reported in the Literature since it provides at the same time the postoperative advantages associated with minimal access surgery and a safe oncological removal of the polyp with low risks of complications.

Laparoscopic splenectomy in patients under the age of eighteen. Experience in 18 cases.

BACKGROUND: Pediatric surgery is now in the forefront of minimal access procedures. Although pediatric surgeons have been skeptic about laparoscopic splenectomy, recently minimally invasive approach for spleen removal has been revaluated also in young patients. Purpose of this study was to report Authors' personal experience in patients under eighteen who underwent laparoscopic splenectomy. Results of the procedure were evaluated. PATIENTS AND METHODS: A retrospective review was undertaken in 18 splenectomised patients under the age of eighteen. Indications were hereditary spherocytosis in 10 patients, ß-thalassemia in 4, idiopathic thrombocytopenic purpura in 3 and a splenic cyst in 1 child. RESULTS: No intra-operative complications occurred. No conversion to open surgery was reported. During the follow-up one case of portal vein thrombosis, treated by medical therapy, was encountered and no other postoperative complications were observed. CONCLUSIONS: Laparoscopic approach has to be preferable for all those children undergoing spleen surgery. In experienced hands, it is of beneficial effects with a very reasonable rate of complications.

Laparoscopic left colectomy: from the perfect knowledge of surgical anatomy to the proper surgical technique.

Laparoscopic colo-rectal surgery has been increasingly accepted and performed in several surgical centres. However, there are still concerns about the intra-operative risks and therefore on the safety of the procedure especially during the learning curve. As a matter of fact, in approximately one third of laparoscopic colo-rectal procedures, an intra-operative complication, mainly bleeding or iatrogenic injuries, may occur. In this paper, according to our experience, we analyse step by step the surgical technique of the laparoscopic left colectomy and evaluate the technical difficulties and complications in order to avoid them.

High precision optical characterization of semiconductor saturable absorber mirrors.

Semiconductor saturable absorber mirrors (SESAMs) have become a key element of many ultrafast laser sources, enabling passively modelocked lasers with >100 GHz repetition rate or with >10 microJ pulse energy. Precise knowledge of the nonlinear optical reflectivity is required to optimize the SESAMs for self-starting passive modelocking at record high repetition rates or pulse energies. In this article, we discuss a new method for wide dynamic range nonlinear reflectivity measurements. We achieve a higher accuracy (<0.05%) with a simpler and more cost-efficient measurement scheme compared with previous measurement systems. The method can easily be implemented for arbitrary wavelength regions and fluence ranges.

Femtosecond thin disk laser oscillator with pulse energy beyond the 10-microjoule level.

We report on a passively mode-locked Yb:YAG thin disk laser oscillator that generates 11.3-microJ pulses without the use of any additional external amplification. A repetition rate of 4 MHz is obtained using a 23.4-m-long multiple-pass cavity that extends the resonator length to a total of 37 m. The nearly transform-limited pulses at 45 W of average output power have a duration of 791 fs with a 1.56-nm-broad spectrum centered at 1030 nm. The laser is operated in a helium atmosphere to eliminate the air nonlinearity inside the resonator that previously limited the pulse energy.

Efficient femtosecond high power Yb:Lu(2)O(3) thin disk laser.

We demonstrate the first passively mode-locked thin disk laser based on Yb:Lu(2)O(3). The laser generates 370-fs pulses with 20.5 W of average power in a diffraction-limited beam (M(2) < 1.1). The nearly transform-limited pulses have a spectral bandwidth of 3.4 nm centered near 1034 nm. With slightly longer pulses (523 fs) we obtained 24 W of average power at a pump power of 56 W, resulting in an optical-to-optical efficiency of 43%, which is higher than for any previously mode-locked thin disk laser.

Temperature-dependent folding allows stable dimerization of secretory and virus-associated E proteins of Dengue and Zika viruses in mammalian cells.

Dengue and Zika are two of the most important human viral pathogens worldwide. In both cases, the envelope glycoprotein E is the main target of the antibody response. Recently, new complex quaternary epitopes were identified which are the consequence of the arrangement of the antiparallel E dimers on the viral surface. Such epitopes can be exploited to develop more efficient cross-neutralizing vaccines. Here we describe a successful covalent stabilization of E dimers from Dengue and Zika viruses in mammalian cells. Folding and dimerization of secretory E was found to be strongly dependent on temperature but independent of PrM co-expression. In addition, we found that, due to the close relationship between flaviviruses, Dengue and Zika viruses E proteins can form heterodimers and assemble into mosaic viral particles. Finally, we present new virus-free analytical platforms to study and screen antibody responses against Dengue and Zika, which allow for differentiation of epitopes restricted to specific domains, dimers and higher order arrangements of E.

Neuropeptide Y release from cultured hippocampal neurons: stimulation by glutamate acting at N-methyl-D-aspartate and AMPA receptors.

L-Glutamate, N-methyl-D-aspartate, DL-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and kainate increased the release of neuropeptide Y-like immunoreactivity from primary cultures of rat hippocampal neurons incubated in Mg2+(1.2 mM)-containing medium. The neuropeptide Y-like immunoreactivity released by 100 microM glutamate was mainly accounted for by neuropeptide Y (1-36), but consisted in part (about 20%) of peptide YY. The effect of 100 microM glutamate on neuropeptide Y-like immunoreactivity release was largely (about 70%) prevented by the N-methyl-D-aspartate receptor antagonist dizocilpine maleate (10 microM), while the remainder (about 30%) was sensitive to the AMPA/ kainate receptor antagonist 6-nitro-7-sulphamoylbenzo(f)quinoxaline-2-3-dione (10 microM). The AMPA(100 microM)-evoked release of neuropeptide Y-like immunoreactivity was strongly antagonized by 6-nitro-7-sulphamoylbenzo(f)quinoxaline-2-3-dione and by 1-aminophenyl-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine, but it was in part (15-20%) sensitive to dizocilpine. The releases of neuropeptide Y-like immunoreactivity elicited by glutamate, N-methyl-D-aspartate, AMPA and kainate were all strongly Ca(2+)-dependent. Tetrodotoxin (1 microM) abrogated the N-methyl-D-aspartate-evoked release and partly inhibited the release caused by glutamate, but did not modify significantly AMPA- or kainate-evoked release. Removal of Mg2+ from the medium caused increase of neuropeptide Y-like immunoreactivity release, an effect prevented by dizocilpine maleate or 7-Cl-kynurenate. Cyclothiazide (10 microM), a drug known to prevent AMPA receptor desensitization, enhanced the neuropeptide Y-like immunoreactivity release elicited by 100 microM AMPA, but not that caused by 100 microM kainate. However, when used at a lower concentration (50 microM), kainate elicited a response that was potentiated significantly by cyclothiazide. It is concluded that glutamate can stimulate Ca(2+)-dependent release of neuropeptide Y from hippocampal neurons mainly through N-methyl-D-aspartate receptors and, less so, by activating cyclothiazide-sensitive receptors of the AMPA-preferring type.