Investigation of random telegraph signal in two junction layouts of proton irradiated CMOS SPADs.

This paper focuses on the understanding of the Random Telegraph Signal (RTS) in Single-Photon Avalanche Diodes (SPAD). We studied the RTS of two different SPAD layouts, designed and implemented in a 150-nm CMOS process, after proton irradiation. The two structures are characterized by different junction types: the first structure is constituted by a P+/Nwell junction, while the second is formed by a Pwell/Niso junction. RTS occurrence has been measured in about one thousand SPAD pixels and the differences addressed in two layouts are motivated and discussed. Hypotheses on the RTS origin are drawn by analyzing the RTS time constants and the RTS occurrence evolution as a function of the annealing temperature.

Angiopoietin-1 and Angiopoietin-2 in metabolic disorders: therapeutic strategies to restore the highs and lows of angiogenesis in diabetes.

The morbidity and mortality of diabetes mellitus are mostly attributed to cardiovascular complications. Despite tremendous advancement in glycemic control, anti-diabetic medications have failed to revert vascular impairment once triggered by the metabolic disorder. The angiogenic growth factors, Angiopoietin-1 (Ang1) and Angiopoietin-2 (Ang2), are crucial regulators of vessel formation and maintenance starting with embryonic development and continuing through life. In mature vessels, angiopoietins control vascular permeability, inflammation and remodeling. A crucial role of angiopoietins is to drive vascular inflammation from the active to the quiescent state, enabling restoration of tissue homeostasis. The mechanism is of particular importance for healing and repair after damage, two conditions typically impaired in metabolic disorders. There is an emerging body of evidences suggesting that the imbalance of Ang1 and Ang2 regulation, leading to an increased Ang2/Ang1 ratio, represents a culprit of the vascular alterations of patients with type-2 diabetes mellitus. Pharmacological modulation of Ang1 or Ang2 actions may help prevent or delay the onset of diabetic vascular complications by restoring vessel function, favoring tissue repair and maintaining endothelial quiescence. In this review, we present a summary of the role of Ang1 and Ang2, their involvement in diabetic complications, and novel therapeutic strategies targeting angiopoietins to ameliorate vascular health in metabolic disorders.

Effect of miR-21 and miR-30b/c on TRAIL-induced apoptosis in glioma cells.

Glioblastoma is the most frequent brain tumor in adults and is the most lethal form of human cancer. Despite the improvements in treatments, survival of patients remains poor. To define novel pathways that regulate susceptibility to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in glioma, we have performed genome-wide expression profiling of microRNAs (miRs). We show that in TRAIL-resistant glioma cells, levels of different miRs are increased, and in particular, miR-30b/c and -21. We demonstrate that these miRs impair TRAIL-dependent apoptosis by inhibiting the expression of key functional proteins. T98G-sensitive cells treated with miR-21 or -30b/c become resistant to TRAIL. Furthermore, we demonstrate that miR-30b/c and miR-21 target respectively the 3' untranslated region of caspase-3 and TAp63 mRNAs, and that those proteins mediate some of the effects of miR-30 and -21 on TRAIL resistance, even in human glioblastoma primary cells and in lung cancer cells. In conclusion, we show that high expression levels of miR-21 and -30b/c are needed to maintain the TRAIL-resistant phenotype, thus making these miRs as promising therapeutic targets for TRAIL resistance in glioma.

Lack of Influence of the Androgen Receptor Gene CAG-Repeat Polymorphism on Clinical and Electrocardiographic Manifestations of the Brugada Syndrome in Man.

BACKGROUND: Clinical studies suggest that testosterone (T) plays an important role in the male predominance of the clinical manifestations of the Brugada syndrome (BS). However, no statistically significant correlations have been observed between T levels and electrocardiogram (ECG) parameters in the BS patients. We investigated whether the hormonal pattern and the variation within CAG repeat polymorphism in exon 1 of the androgen receptor (AR) gene, affecting androgen sensitivity, are associated with the Brugada ECG phenotype in males. METHODS AND RESULTS: 16 male patients with BS (mean age 45.06 ± 11.3 years) were studied. 12-lead ECG was recorded. Blood levels of follicle-stimulating hormone, luteinizing hormone, prolactin, testosterone, free-T, dihydrotestosterone, 17-ß-estradiol, estrone, 3-alpha-androstanediol-glucuronide, delta-4-androstenedione, dehydroepiandrosterone sulphate, progesterone, 17-hydroxyprogesterone, and sex hormone binding globulin were assayed. Genotyping of CAG repeats on DNA extracted from leukocytes was carried out. No relationship was found between hormone values and ECG parameters of BS. BS patients showed the CAG length normally recognized in the human polymorphism range and the number of CAG repeats did not correlate with the ECG pattern of BS. CONCLUSIONS: The AR CAG repeat length does not correlate with the ECG features of the patients affected by BS. The search for genes downstream AR activation as possibly responsible for the increased risk of spontaneous arrhythmias in BS males after puberty is warranted.

In vivo and in vitro assessment of pathways involved in contrast media-induced renal cells apoptosis.

Contrast-induced nephropathy accounts for >10% of all causes of hospital-acquired renal failure, causes a prolonged in-hospital stay and represents a powerful predictor of poor early and late outcome. Mechanisms of contrast-induced nephropathy are not completely understood. In vitro data suggests that contrast media (CM) induces a direct toxic effect on renal tubular cells through the activation of the intrinsic apoptotic pathway. It is unclear whether this effect has a role in the clinical setting. In this work, we evaluated the effects of CM both in vivo and in vitro. By analyzing urine samples obtained from patients who experienced contrast-induced acute kidney injury (CI-AKI), we verified, by western blot and immunohistochemistry, that CM induces tubular renal cells apoptosis. Furthermore, in cultured cells, CM caused a dose-response increase in reactive oxygen species (ROS) production, which triggered Jun N-terminal kinases (JNK1/2) and p38 stress kinases marked activation and thus apoptosis. Inhibition of JNK1/2 and p38 by different approaches (i.e. pharmacological antagonists and transfection of kinase-death mutants of the upstream p38 and JNK kinases) prevented CM-induced apoptosis. Interestingly, N-acetylcysteine inhibited ROS production, and thus stress kinases and apoptosis activation. Therefore, we conclude that CM-induced tubular renal cells apoptosis represents a key mechanism of CI-AKI.

Metabolic or bariatric surgery? Long-term effects of malabsorptive vs restrictive bariatric techniques on body composition and cardiometabolic risk factors.

BACKGROUND: Obesity is an increasing health problem and surgery seems to be the only treatment effective in achieving weight loss without relapse. Among bariatric techniques, many differences exist in terms of weight loss and resolution of comorbidities. Up to now, there are no prospective studies comparing long-term effects of malabsorptive vs restrictive techniques. OBJECTIVE: In this study, cardiometabolic risk factors and body composition changes after malabsorptive biliointestinal bypass (BIBP) and restrictive laparoscopic adjustable gastric banding (LAGB) were compared during a 4-year follow-up. DESIGN: Prospective, case-control and cohort study. PATIENTS: In all, 80 obese subjects, matched for weight and age. Altogether, 40 patients underwent BIBP and 40 underwent LAGB. MEASUREMENTS: Weight, body composition, fasting and post-loading plasma glucose and insulin, homeostatic model assessment index (HOMA-I), lipid profile, blood pressure (BP), erythrocyte sedimentation rate and fibrinogen were monitored at baseline, 12 and 48 months. RESULTS: At 12 months after surgery, a significant reduction in body mass index, total fat mass (FM), trunk FM (trFM), trFM/legs FM (lFM) ratio (trFM/lFM), triglycerides, BP and inflammation markers was observed in both groups. BIBP patients showed a significant reduction in total cholesterol (Tot-C), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C), whereas the LAGB group showed a significant increase of HDL-C. A further improvement of all the parameters evaluated was seen in the BIBP group at 48 months after surgery. CONCLUSIONS: Both bariatric procedures exerted positive effects on cardiometabolic risk factors and on weight loss in the population studied, but on the long-term period, HOMA-I, Tot-C/HDL-C ratio and body composition improvements were more evident after BIBP. We conclude that malabsorptive BIBP seems to be more effective than LAGB in treating visceral obesity and its metabolic complications.

Multislice CT angiography in the selection of patients with ruptured intracranial aneurysms suitable for clipping or coiling.

INTRODUCTION: We sought to establish whether CT angiography (CTA) can be applied to the planning and performance of clipping or coiling in ruptured intracranial aneurysms without recourse to intraarterial digital subtraction angiography (IA-DSA). METHODS: Over the period April 2003 to January 2006 in all patients presenting with a subarachnoid haemorrhage CTA was performed primarily. If CTA demonstrated an aneurysm, coiling or clipping was undertaken. IA-DSA was limited to patients with negative or inconclusive CTA findings. We compared CTA images with findings at surgery or coiling in patients with positive CTA findings and in patients with negative and inconclusive findings in whom IA-DSA had been performed. RESULTS: In this study, 224 consecutive patients (mean age 52.7 years, 135 women) were included. In 133 patients (59%) CTA demonstrated an aneurysm, and CTA was followed directly by neurosurgical (n = 55) or endovascular treatment (n = 78). In 31 patients (14%) CTA findings were categorized as inconclusive, and in 60 (27%) CTA findings were negative. One patient received surgical treatment on the basis of false-positive CTA findings. In 17 patients in whom CTA findings were inconclusive, IA-DSA provided further diagnostic information required for correct patient selection for any therapy. Five ruptured aneurysms in patients with a nonperimesencephalic SAH were negative on CTA, and four of these were also false-negative on IA-DSA. On a patient basis the positive predictive value, negative predictive value, sensitivity, specificity and accuracy of CTA for symptomatic aneurysms were 99%, 90%, 96%, 98% and 96%, respectively. CONCLUSION: CTA should be used as the first diagnostic modality in the selection of patients for surgical or endovascular treatment of ruptured intracranial aneurysms. If CTA renders inconclusive results, IA-DSA should be performed. With negative CTA results the complementary value of IA-DSA is marginal. IA-DSA is not needed in patients with negative CTA and classic perimesencephalic SAH. Repeat IA-DSA or CTA should still be performed in patients with a nonperimesencephalic SAH.

Multimodal imaging of esophagus and cardia cancer before and after treatment.

PURPOSE: Prognosis and treatment of esophagus and cardia cancer (ECC) depend on the precision with which the disease is staged according to the American Joint Committee of Cancer (AJCC) criteria. Imaging modalities normally used in clinical staging are esophagography, esophagoscopy, endoscopic ultrasound (EUS), computed tomography (CT) and positron emission tomography- CT fusion (CT-PET). The combination of these methods is crucial in determining not only the right diagnosis but also the stage and follow-up after multimodal treatment. The purpose of our investigation was to define the role of each imaging modality in determining the most appropriate treatment options in patients with ECC. MATERIALS AND METHODS: Fifty-six patients with ECC diagnosed by X-ray of the upper digestive tract, endoscopy and biopsy were staged using EUS, chest and abdomen CT scan, and CT-PET. Thirty-four patients in stage II and 18 patients in stage III underwent surgery after neoadjuvant chemotherapy; four patients in stage IV were treated with the positioning of an endoprosthesis after chemoradiotherapy. In the 52 patients who had surgery, follow-up included digestive tract X-ray, endoscopy and CT of the chest and abdomen every 6-8 months for the first 3 years. CT-PET was only performed in patients with a clinical suspicion of recurrence and/or CT findings suspicious of persistent disease (12 cases). RESULTS: In all 56 patients, endoscopy, EUS, CT and CT-PET in combination were crucial in determining the site of disease, locoregional extent and depth of esophageal wall penetration (T), and any involvement of the mediastinal lymph nodes (N1), extrathoracic lymph nodes (M1) or hepatic metastases. In the locoregional staging of ECC before chemotherapy, we were able to differentiate T2-T3 from T4 in 40 patients; T4 disease was found in 12 potentially resectable cases. We were able to distinguish N0 from N1 in 12 patients. In four cases, the presence of small lymph node and/or liver metastases prompted positioning of an endoprosthesis. The specificity of CT in detecting small lymph nodes in the mediastinum was less than 50% while for CT-PET, it was more than 80%; EUS revealed sensitivity higher than 90% but a low specificity in seven cases. Only CT-PET revealed metastatic subdiaphragmatic lymph nodes (diameter <15 mm) in three cases. Presurgical restaging of the 18 patients (stage III) who had chemotherapy was based on endoscopy, EUS, CT of the chest and abdomen and CT-PET (only in suspected cases) and was compatible with surgery. Anastomotic recurrence was diagnosed in 16 patients by endoscopy with associated biopsy; any intramediastinal spread from anastomotic recurrences was evaluated by chest CT, and CT-PET in suspected cases. CONCLUSIONS: X-ray of the upper digestive tract and chest and abdomen CT scan are useful in preliminary evaluation of ECC. Endoscopy is particularly indicated for evaluating tumour morphology, taking biopsies for a histological diagnosis and the early diagnosis of anastomotic recurrences. EUS is indicated mainly for evaluating T stage before and after chemotherapy or chemoradiotherapy. CT-PET is extremely useful in identifying small mediastinal metastatic lymph nodes (N1) or extrathoracic lymph nodes (M1) and hepatic metastases (

Imaging before and after multimodal treatment for malignant pleural mesothelioma.

PURPOSE: Computed tomography (CT), magnetic resonance (MR) and positron emission tomography (PET) have a very important role in the diagnosis of malignant pleural mesothelioma (MPM) in the choice of chemoradiotherapy alone or in combination with surgery and in evaluating possible recurrence. It is also essential for assessing the possible benefits of radical surgery (pleuropneumonectomy) in terms of patient survival. MATERIALS AND METHODS: We considered 28 patients suffering from MPM whose mean survival after diagnosis was 15-18 months. Sixteen of these patients had radiotherapy or chemoradiotherapy alone, according to standard protocols, while 12 also underwent surgery. The CT features of MPM were thoroughly examined, as was the role of PET and CT-PET in achieving accurate disease staging and consequent selection of candidates for surgery. RESULTS: Nine of the 12 patients who underwent pleuropneumonectomy had no significant survival advantage over the mean survival in the 16 who were not operated whereas the other three lived 1-3 years longer. Two patients underwent surgery after an optimal response to chemoradiotherapy, but both survived less than a year due to particularly aggressive recurrences. CONCLUSIONS: CT, PET and CT-PET are indicated for diagnosis and, above all, for staging of MPM, in the selection of patients who might benefit from surgery after neoadjuvant therapy and also in identifying small recurrences and/or remote metastases. Being highly specific, PET is essential in the follow-up of patients undergoing chemoradiotherapy alone and/or surgery. Each imaging modality has its advantages and limitations, but their combined use is crucial in determining the most appropriate treatment options for patients with MPM.

[Role of CT/111In-octreotide SPECT digital fusion imaging in the localization of loco-regional recurrence of medullary thyroid carcinoma]. / Ruolo della tecnica digitale di fusione di immagini TC/111In-octreotide SPECT nella localizzazione di recidiva loco-regionale di carcinoma midollare della tiroide.

The case of a female patient affected by a sporadic medullary thyroid carcinoma (pT1N1aM0 at the onset) is reported. The patient had been initially treated by total thyroidectomy and lymphadenectomy of the central and lateral portions of the neck. During the following 30 years of follow-up, the patient experienced 3 consecutive loco-regional tumoral relapses. At the moment of each relapse, an increase of serum calcitonin levels has anticipated the subsequent detection of tumor deposits at clinical and radiological examination (ultrasound, CT scan). It is well known that, after multiple operations, the structures of the neck can present anatomical distortion and fibrosis that can interfere with ultrasound and CT scan interpretation. In the present patient, a scintigraphic examination with 111In-octreotide, that is a specific radio-tracer for somatostatin receptors, allowed to correctly visualize a tumoral relapse in the left thyroid bed, located in deep para-tracheal planes: in that site the CT scan only showed an unspecific solid mass. Furthermore, the utilization of a digital image fusion technique for CT scan and 111In-octreotide SPECT, furnished useful information for the purpose of planning an accurate re-intervention, both morphologic information (mass size, precise site of the mass and their relationship with the surrounding anatomical structures) and functional information (biological characterization of the mass that was classified as a neuroendocrine tumoral deposit with high density of somatostatin receptors.

Injuries in whitewater kayaking.

OBJECTIVE: To provide epidemiological data on whitewater kayaking injuries using a descriptive study. METHODS: A retrospective survey was distributed at whitewater events and club meetings, and made available and advertised on the world wide web, through postings and announcements to newsgroups, related sites, and search engines. Data on sex, age, experience, and ability were collected. Injury data collected included mechanism, activity, difficulty of rapid, and self reported severity. RESULTS: Of the 392 kayaking respondents included in the final analysis, 219 suffered 282 distinct injury events. The number of days spent kayaking per season was the only independent predictor of injury. The overwhelming majority of injuries occurred while the kayaker was still in the boat (87%). Striking an object was the most common mechanism of injury (44%), followed by traumatic stress and overuse (25% each). The most common types of injury were abrasion (25%), tendinitis (25%), contusion (22%), and dislocation (17%). The upper extremity, especially the shoulder, was the most commonly injured area of the body. Although half of injured kayakers sought medical care for their injury, and almost one third missed more than one month of kayaking because of the injury, almost all (96%) reported a complete or good recovery. CONCLUSIONS: Factors relating to likelihood of injury appear to be connected with exposure, namely the number of days a year that the sport was pursued. Except for class V (extreme) kayakers, reports of injuries paralleled the number of participants. Kayakers reported injuries predominantly on rivers that they assessed to be at a level appropriate to their skills.

[Internal abdominal hernia. Unusual cause of intestinal occlusion]. / Ernia addominale interna. Una insolita causa di occlusione intestinale.

Internal abdominal hernias are an unusual cause of intestinal occlusion. They are responsible for 2% of all the intestinal obstructions. Various types of hernia have been described. The diagnosis is difficult, but should be suspected in patients suffering from intestinal obstruction who have undergone earlier laparotomy. Diagnosis is even more difficult in cases of congenital internal hernia. The authors report a case of left paraduodenal hernia (congenital), and a case of transmesenteric hernia (acquired). Both patients complained of a short history of abdominal pain and characteristic symptoms of acute abdomen (nausea, vomit, cramps and obstipation). Emergency surgery using laparotomy enabled diagnosis and treatment. The authors underline the difficulty of diagnosing these hernias and emphasise the diagnostic and therapeutic importance of emergency surgery.

Visceral fat loss evaluated by total body magnetic resonance imaging in obese women operated with laparascopic adjustable silicone gastric banding.

OBJECTIVE: To investigate the changes of visceral fat, as compared with total and subcutaneous adipose tissue (AT) in obese patients operated with laparascopic adjustable silicone gastric banding (LAP-BAND). SUBJECTS: Six premenopausal morbid obese (body mass index range: 41.4-44.2 kg/m2) women, aged 38-42 y, operated with LAP-BAND, evaluated before, 8 weeks after, and 24 weeks after surgery. MEASUREMENTS: Fat distribution was analysed by total body multi-slices MRI. Total AT, gluteo-femoral subcutaneous AT, abdominal subcutaneous AT, and abdominal visceral AT volumes were measured. FM was calculated from MRI-determined total AT volume and AT density. RESULTS: A weight loss of 9.9+/-3.8 kg was observed in the first 8 weeks after LAP-BAND (0-8 weeks), and a further weight loss of 7.1+/-4.9 kg in the subsequent 16 weeks (8-24 weeks). Total AT showed a statistically significant reduction of 6.2+/-4.0 l in 0-8 weeks and a further significant reduction of 7.7+/-3.9 l in 8-24 weeks (P<0.01 from baseline). A similar trend was observed for both abdominal and gluteo-femoral subcutaneous AT. Visceral AT showed a statistically significant reduction of 1.0+/-0.9 l in the 0-8 weeks (P<0.05) and a further non-significant reduction of 0.6+/-0.7 l in 8-24 weeks (P<0.05 from baseline). In 0-8 weeks, the relative reduction of visceral AT was higher than the relative reduction of both total AT and gluteo-femoral subcutaneous AT. A highly significant correlation was observed between the reduction of total AT and the reduction of both abdominal and gluteo-femoral subcutaneous AT. By contrast, in 0-8 weeks, the reduction of total AT and the reduction of visceral AT were not correlated. In a subsequent analysis, both observations collected in the first 8 weeks after LAP-BAND and observations collected in the last 16 weeks are simultaneously considered, leading to a total of 12 time periods (two time periods for each individual patient). In order to identify factors associated with preferential visceral fat reduction, we calculated for each of the 12 time periods the difference between the percentage changes of visceral AT and the percentage changes of total AT. The relationship between this difference and several other variables were investigated by simple correlation analysis. The only variables found to be associated were the initial visceral AT volume, the absolute level of weight loss (kg) per week of observation, and the relative level of weight loss (%) per week of observation. CONCLUSION: In the phase of rapid weight loss following LAP-BAND, a preferential mobilization of visceral fat, as compared with total and subcutaneous AT, can occur. However, this preferential visceral fat reduction occurs only in those patients presenting higher levels of visceral fat deposition at baseline and higher levels of weight loss. International Journal of Obesity (2000)24, 60-69

Adrenocortical oncocytoma: case report and review of the literature.

Only 9 oncocytic neoplasms of true adrenal origin have been described to date. It therefore seemed of interest to study the histochemical and ultrastructural features of a non-functioning monolateral adrenocortical oncocytoma which was incidentally detected by ultrasonography and magnetic resonance imaging in a 28-year-old woman. The tumor was round, well encapsulated and weighed 73 g. It consisted of islets of eosinophilic cells, and did not display any sign of necrosis. The proliferation rate (as evaluated by mitotic index and percentage of MIB-1 Ki67 positive cells) was low, and atypic mitoses were absent; some rare cells with nuclear atypias were observed and the capsule was focally invaded by oncocytes. Immunocytochemistry did not show expression of vimentin or cytokeratin. The oncocytes had an abundant cytoplasm packed with mitochondria containing plate-like cristae. Smooth endoplasmic reticulum was virtually absent, while rough endoplasmic reticulum cisternae and free ribosomes were abundant. Although the classic histological approach clearly indicates the benign nature of the tumor, the immunocytochemical and ultrastructural features of oncocytes may suggest their potential for malignant behavior.

Online medical surveys: using the Internet as a research tool.

Technologic advances and popularization of the World Wide Web now allow researchers to use the Internet for medical surveys. The Internet provides access to a rapidly growing and widespread population of potential research subjects. Specific populations can be selected from the larger Internet community, which is itself becoming more representative of society as a whole. The hypertext markup language can be used to create interactive forms with an intuitive and intelligent interface. Response collection by means of common gateway interface scripts can afford automated data compilation and exportation to other software packages. Furthermore, real-time evaluation of incoming data can ensure that the data are complete and accurate before they are accepted. Used properly and for appropriate research projects, the Internet can provide a fast, cost-effective, and efficient mechanism for administering medical surveys.

Injury in traditional and sport rock climbing.

The objective of this study was to compare patterns of injury found in traditional rock climbing with those found in sport climbing. A questionnaire was administered to rock climbers by mail, in person, and via the World Wide Web. Injuries that occurred while rope-protected climbing on rock were analyzed regarding the anatomical location and the mechanism and activity at the time of injury. Ninety-four climbers reported sustaining an injury while rope-protected climbing on rock. Most injuries occurred while leading and involved the upper extremity, especially the fingers. Falling was the predominant mechanism of injury on traditional climbs, and stress over a joint while attempting a difficult move was the most common mechanism on sport climbs. Potential for injury prevention lies in teaching climbers to recognize the limitations of the fingers as weight-bearing structures.

Distinct functions and requirements for the Cys-His boxes of the human immunodeficiency virus type 1 nucleocapsid protein during RNA encapsidation and replication.

The process of retroviral RNA encapsidation involves interaction between trans-acting viral proteins and cis-acting RNA elements. The encapsidation signal on human immunodeficiency virus type 1 (HIV-1) RNA is a multipartite structure composed of functional stem-loop structures. The nucleocapsid (NC) domain of the Gag polyprotein precursor contains two copies of a Cys-His box motif that have been demonstrated to be important in RNA encapsidation. To further characterize the role of the Cys-His boxes of the HIV-1 NC protein in RNA encapsidation, the relative efficiency of RNA encapsidation for virus particles that contained mutations within the Cys-His boxes was measured. Mutations that disrupted the first Cys-His box of the NC protein resulted in virus particles that encapsidated genomic RNA less efficiently and subgenomic RNA more efficiently than did wild-type virus. Mutations within the second Cys-His box did not significantly affect RNA encapsidation. In addition, a full complement of wild-type NC protein in virus particles is not required for efficient RNA encapsidation or virus replication. Finally, both Cys-His boxes of the NC protein play additional roles in virus replication.