Strong Anisotropic Spin-Orbit Interaction Induced in Graphene by Monolayer WS_{2}.

We demonstrate strong anisotropic spin-orbit interaction (SOI) in graphene induced by monolayer WS_{2}. Direct comparison between graphene-monolayer WS_{2} and graphene-bulk WS_{2} systems in magnetotransport measurements reveals that monolayer transition metal dichalcogenide can induce much stronger SOI than bulk. Detailed theoretical analysis of the weak antilocalization curves gives an estimated spin-orbit energy (E_{so}) higher than 10 meV. The symmetry of the induced SOI is also discussed, and the dominant z→-z symmetric SOI can only explain the experimental results. Spin relaxation by the Elliot-Yafet mechanism and anomalous resistance increase with temperature close to the Dirac point indicates Kane-Mele SOI induced in graphene.

Evidence of nonthermal particles in coronal loops heated impulsively by nanoflares.

The physical processes causing energy exchange between the Sun's hot corona and its cool lower atmosphere remain poorly understood. The chromosphere and transition region (TR) form an interface region between the surface and the corona that is highly sensitive to the coronal heating mechanism. High-resolution observations with the Interface Region Imaging Spectrograph (IRIS) reveal rapid variability (~20 to 60 seconds) of intensity and velocity on small spatial scales (≲500 kilometers) at the footpoints of hot and dynamic coronal loops. The observations are consistent with numerical simulations of heating by beams of nonthermal electrons, which are generated in small impulsive (≲30 seconds) heating events called "coronal nanoflares." The accelerated electrons deposit a sizable fraction of their energy (≲10(25) erg) in the chromosphere and TR. Our analysis provides tight constraints on the properties of such electron beams and new diagnostics for their presence in the nonflaring corona.

Ultrasonographic and functional changes of the ulnar nerve at Guyon's canal after carpal tunnel release.

OBJECTIVE: To describe morphologic and functional modifications of the ulnar nerve at the wrist in carpal tunnel syndrome (CTS) after carpal tunnel release (CTR). METHODS: Ultrasonography was used to study the cross sectional area (CSA) of the ulnar nerve at Guyon's canal, before and 1 and 6 months after CTR, in 18 CTS patients. A parallel electrophysiological and clinical analysis was also conducted. RESULTS: CSA of the ulnar nerve significantly increased 6 months after CTR. Ten (55%) cases showed abnormal CSA values compared to a control group before surgery and five (28%) at 6 month follow-up. In addition, there were improvements in the motor and sensory ulnar axon recruitment properties and the conduction values in sensory ulnar fibres. Patients with extra-median distribution of paresthesia (4 subjects) were free from symptoms. CONCLUSIONS: CTR has a significant effect not only on the anatomical geometry of Guyon's canal, but also on the morphology and function of the ulnar nerve. SIGNIFICANCE: In CTS, high pressure in the carpal tunnel may result in anatomical changes of ulnar nerve, thus causing functional impairment to the ulnar fibres. CTR appears to reverse some of this damage.

Ultrasonography before and after surgery in carpal tunnel syndrome and relationship with clinical and electrophysiological findings. A new outcome predictor?

OBJECTIVE: To measure the cross-sectional area (CSA) of the median nerve by ultrasonography (US) before and after surgery in subjects with carpal tunnel syndrome (CTS), and to verify whether the normalization of presurgical parameters can be predicted by presurgical CSA values. PATIENTS AND METHODS: Sixty-seven consecutive cases, mean age 60.5 years, underwent surgical decompression. Before surgery, clinical and electrophysiological severity and self-assessment of symptoms (using the Boston questionnaire, BQ) were recorded. CSAs were measured proximal to the carpal tunnel inlet (CSA-I), at mid-tunnel (CSA-M), and at the tunnel outlet (CSA-O). Follow-ups were performed 1 and 6 months after surgery. Logistic regressions were performed with normalization of CSA, clinical and electrophysiological parameters as independent variables, and presurgical findings as dependent variables. RESULTS: Before and after surgery there were correlations between CSA-I and clinical and electrophysiological severity scales. After 1 and 6 months, the clinical, electrophysiological, and BQ findings improved. CSA-I reduced at the 1-month follow-up and CSA-O increased between the first and second follow-up. Presurgical values of CSA-I could predict the normalization of its postsurgical value, normalization of the clinical severity scale, BQ, and full patient satisfaction postsurgery. CONCLUSIONS: CSA-I is the most sensitive US measurement before surgery. The presurgical value of CSA-I is a predictor of postsurgical normalization of clinical parameters and of its own value.

Sex differences in carpal tunnel syndrome: comparison of surgical and non-surgical populations.

Carpal tunnel syndrome (CTS) patients are known to show gender-related differences in severity. The main aim of this cross-sectional study was to determine whether these differences between women and men may be related to age, education or body mass index (BMI) in two populations, one with idiopathic CTS not treated surgically and the other with idiopathic CTS treated by surgical decompression. A secondary aim was to check differences in surgical results between the genders in the surgical population. The non-surgical population consisted of 172 subjects (126 women and 46 men, mean age 55.1 years) whose data were obtained at electrophysiological examination. The surgical population consisted of 219 patients (177 women and 42 men, mean age 55.1 years) whose data were obtained before surgery. Age, education, BMI, duration of symptoms, electrophysiological and clinical severity of CTS (with ordinal scales), and the self-administered Boston Questionnaire (BQ) of symptoms and functional status of hands were considered. There were no differences in age or clinical and electrophysiological severity between women and men in either group, except for distal motor latency of the median nerve that was more delayed and duration of symptoms that was shorter in men than women in non-surgical sample. Men had a higher BMI than women. Women had higher BQ scores in the surgical and non-surgical samples. These differences remained when the results were analysed matching the men with an identical number of women of the same age, education and BMI. In the surgical population, the results of surgical decompression did not modify the gender-related differences in severity. As in many other syndromes and diseases, for a given clinical severity, women with CTS were more sensitive than men in reporting their symptoms. Risk factors of CTS, such as age, education and BMI, were not responsible for these differences. The results of surgical decompression were similar in men and women.

123I-MIBG radioaerosol lung clearance in COPD patients with fixed and partially reversible obstruction to evaluate the functional status of pulmonary adrenergic innervation.

In order to test the hypothesis that a greater sympathetic activity underlies partial reversibility of the bronchial obstruction in selected patients with chronic obstructive pulmonary disease (COPD), we assessed the pulmonary clearance of inhaled I-meta-iodobenzylguanidine ( I-MIBG) radioaerosol in 10 patients with fixed and nine with reversible obstruction. The clearance of inhaled I-MIBG is known to be inversely related to I-MIBG uptake by adrenergic terminals. Groups were matched for age and judged free from confounding comorbidity. The penetration index did not distinguish between the groups (fixed obstruction, 97.39+/-14.59%; reversible obstruction, 89.09+/-19.95%; P=0.659); this excludes the possibility that the inequality of tracer penetration could affect I-MIBG clearance. The I-MIBG clearance was 140.92+/-7.67 min in patients with fixed obstruction and 151.08+/-31.54 min in patients with reversible obstruction ( P=0.604). In conclusion, COPD patients with fixed and reversible obstruction show comparable binding of the tracer to adrenergic pulmonary receptors. Thus, a greater receptor responsiveness or post-receptor mechanism probably underlies the partial reversibility of bronchial obstruction.

Inter-observer reproducibility and responsiveness of a clinical severity scale in surgically treated carpal tunnel syndrome.

OBJECTIVES: To test a recently proposed carpal tunnel syndrome (CTS) clinical severity scale for reproducibility between two observers (neurosurgeon and neurophysiologist) before surgery, for responsiveness to changes in clinical status 6 months after surgery, and for correlations with the electrophysiological findings and 'Boston Carpal Tunnel Syndrome Questionnaire' (BQ). MATERIAL AND METHODS: The tests were applied prospectively to a consecutive series of 254 hands with idiopathic CTS, referred for surgical decompression. The hands belonged to 219 subjects (177 women and 42 men, mean age 55.6). RESULTS: Percentage agreement between the two observers in assigning severity to the same class was 78% and Cohen coefficient kappa was 0.69 (P < 0.001). The scale was found to be responsive to changes in clinical status after surgery. Direct correlations were also found between the scale and patient age, duration of symptoms, BQ scores and the neurophysiological severity scale. The significance of these associations was maintained for 6 months after the operation. CONCLUSION: This clinical severity scale is simple, reproducible and sensitive for evaluating severity of CTS in patients undergoing surgery.

Primary intraventricular haemorrhage in adults.

INTRODUCTION: Primary intraventricular haemorrhage (PIVH) is an uncommon type of intracerebral haemorrhage. Relatively little is known about clinical and imaging features, and even less about prognosis and predictors of mortality. MATERIAL AND METHODS: We analysed clinical and imaging features, causative factors and outcome of 26 patients with CT brain scan evidence of PIVH. A multivariate regression model of failure time data was used to assess predictors of in-hospital mortality. RESULTS: Loss of consciousness was the first manifestation of PIVH in six patients and occurred after all other symptoms in five. In other patients, onset was characterized by headache, vomiting, confusion and disorientation (n=8) or by headache with or without vomiting (n=7). Angiography revealed vascular malformations in eight patients (31%). Other possible causative factors were clotting disorder in one patient and arterial hypertension in 10. No cause was identified in seven patients. Early hydrocephalus was the most frequent complication and resolved spontaneously in a minority of patients. In-hospital mortality was high (42%): four patients died early of direct consequence of bleeding and seven died after clinical worsening because of increasing hydrocephalus or other adverse events. Multivariate analysis indicated Glasgow Coma Scale < or = 8 (OR 4.67; 95% CI 1.22-17.92) and early hydrocephalus (OR 4.93; 95% CI 1.13-21.59) as independent predictors of in-hospital mortality. CONCLUSION: In patients with PIVH, hydrocephalus seems to be a critical determinant of in-hospital mortality and this suggests the need for early treatment strategies.

Validity of thyroglobulin mRNA assay in peripheral blood of postoperative thyroid carcinoma patients in predicting tumor recurrences varies according to the histologic type: results of a prospective study.

BACKGROUND: The objective of the current study was to evaluate the ability of serum thyroglobulin mRNA assay in detecting local and distant recurrences in patients who underwent surgery for thyroid carcinoma. METHODS: Sixty-six consecutive patients were studied. One year after surgery, all patients underwent clinical examination and radioiodine scan, and a blood sample was taken for serum thyroglobulin (Tg) immunoassay and for Tg mRNA assay by reverse transcription-polymerase chain reaction (RT-PCR). RNA was extracted from cells pellet and analyzed by RT-PCR using specific primers for Tg. RESULTS: Thyroglobulin mRNA was detected in 14 (21.2%) patients. Seven of 16 patients with elevated serum thyroglobulin had detectable Tg mRNA. Six of 30 (20%) patients with absent or minimal thyroid bed radioiodine uptake and 7 of 36 (19.4%) patients with significant thyroid bed uptake had detectable Tg mRNA. Among 5 patients with metastases, only 1 (20%) showed circulating Tg mRNA. Overall, the sensitivity, specificity, and accuracy of Tg mRNA assay in predicting the results of the (131)I whole-body scans was 25%, 80%, 25%, respectively. Fourteen of 53 (26.4%) patients with papillary thyroid carcinoma had detectable thyroglobulin mRNA whereas none of the patients with other histologic types did. The sensitivity, specificity, and accuracy of Tg mRNA assay in predicting the results of the (131)I whole-body scans in patients with papillary thyroid carcinoma was 100%, 75%, and 100%, respectively. Of note, the percentage of cases with detectable Tg mRNA was similar among patients who did not receive postoperative (131)I and those who had postoperative radioiodine treatment. CONCLUSIONS: The current study suggests that the validity of the Tg mRNA assay varies according to the histologic type of thyroid carcinoma and that this assay may play a role in the identification of metastatic disease in the subgroup of patients affected by papillary thyroid carcinoma but does not appear to be sensitive or active enough to direct clinical management.

Potential triggering factors of intracerebral hemorrhage.

The distributions of intracerebral hemorrhage (ICH) according to place of onset, degree of physical activity at onset and potential triggering factors were analyzed in 848 patients with ICH. Patients were grouped according to the presumed cause of ICH: hypertensive ICH, secondary ICH and ICH of undetermined origin. The influence of demographic and temporal factors on the relative frequency of events was also assessed. In 30% of the cases, ICH occurred during inactivity or sedentary activity, in 50% during light exertion and in 20% during moderate/vigorous exertion. During inactivity or sedentary activity, hypertensive ICH was significantly less frequent than secondary ICH (OR 0.32; 95% CI 0.21-0.47) and undetermined ICH (OR 0.36; 95% CI 0.23-0.55), whereas during moderate or vigorous exertion hypertensive ICH was more frequent than secondary (OR 1.88; 95% CI 1.16-3.05) and undetermined ICH (OR 2.29; 95% CI 1.31-4.00) Potential triggering factors were observed in 27% of patients and were significantly more frequent in patients with hypertensive ICH than in patients with secondary ICH (OR 2.90; 95% CI 1.85-4.54) or undetermined ICH (OR 2.44; 95% CI 1.54-3.87). Our findings suggest that many potential external triggers that act mainly by raising blood pressure may interact, and their concurrence may favor cerebral hemorrhage, particularly in hypertensive patients. In many cases, these circumstances of increased risk may be mitigated by preventive measures.

Clinical and neurophysiological outcome of surgery in extreme carpal tunnel syndrome.

INTRODUCTION: Surgical release is the most effective therapy for the symptoms of carpal tunnel syndrome (CTS). It is widely considered that surgery may be ineffective in 'extreme' cases (those with atrophy of the thenar eminence muscles and no sensory and motor response of the median nerve). OBJECTIVE: To report clinical and electrophysiological outcome of 10 subjects with 'extreme' CTS surgically treated. METHODS: Ten hands belonging to 10 patients (9 women and one man, mean age 65 years) underwent surgical release by the mini-incision of the palm technique. All showed atrophy of thenar eminence and absence of motor and sensory responses of the median nerve. The protocol consisted of clinical and electrophysiological evaluation, with the patient completing the self-administered Boston questionnaire (BQ) before the operation and one and 6 months after it. RESULTS: After surgical release, all patients reported an absence of pain and disappearance or reduction of paraesthesia. Six months after the operation, motor and sensory responses of the median nerve returned in 8 and 5 hands, respectively. The BQ showed a significant improvement in symptom and functional scores, although muscle atrophy remained unchanged. No correlation was found between the degree of clinical and electrical improvement and the age of the patients. CONCLUSION: It is possible to obtain good clinical and electrophysiological results even in extreme cases of CTS.

Follicular variant of papillary thyroid carcinoma: a comparative study of histopathologic features and cytology results in 141 patients.

OBJECTIVE: To characterize the histopathologic features of follicular variant of papillary thyroid carcinoma (FVPC) and its cytology results on fine-needle aspiration (FNA) biopsy and compare them with those of papillary thyroid carcinoma (PC). METHODS: We searched the University of Massachusetts Medical Center pathology database for all surgical specimens associated with a diagnosis of FVPC or PC between January 1992 and February 1998 and reviewed the related pathology reports. In addition, the associated preoperative FNA results were analyzed. RESULTS: On initial assessment, FVPC was associated with a significantly lower incidence of cervical lymph node metastatic involvement in comparison with PC (5.6% versus 35.7%; P<0.001). Even though the mean size of FVPC was larger than that of PC (2.57 cm versus 1.75 cm; P<0.05), FVPC showed a lower incidence of thyroid capsule invasion (5.6% versus 11.4%), infiltrative resection margins (2.8% versus 20.0%; P = 0.01), local soft tissue invasion (7.0% versus 25.7%; P<0.005), and multicentricity (25.4% versus 47.1%; P<0.01). Lymphocytic thyroiditis was a common feature of both FVPC (36.6%) and PC (35.7%). FNA biopsy revealed the presence of malignant cells in 9.8% of patients with FVPC in comparison with 67.5% of patients with PC. Most cytology specimens of FVPC (58.8%) were interpreted as suspicious for a malignant lesion or as a follicular neoplasm. CONCLUSION: FVPC is associated with a significantly lower incidence of cervical lymph node metastatic lesions and invasive histologic features than is PC. Long-term prospective clinical studies are needed to determine whether these findings translate into a more benign natural history for this variant of PC. Results of FNA biopsy in FVPC are more commonly interpreted as suspicious rather than malignant; this factor has major implications for preoperative planning.

Sympathetic skin response before and after surgical release of carpal tunnel syndrome.

Sympathetic skin response (SSR) was performed before and 1 year after surgical release of the median nerve in 20 subjects (mean age 52.8 years) with unilateral idiopathic carpal tunnel syndrome (CTS). SSR was evoked by stimulation of the ulnar nerve at the wrist contralateral to the side with CTS, recording from the palm, third (M3) and fifth fingers, and from the third finger contralateral to the side of CTS (M3c). Before surgery, anomalies of M3 SSR were found in 8 hands (40%): M3 SSR was absent in 1 hand; and the M3c/M3 SSR largest area ratio was abnormal in 7 hands, 3 of which also had abnormal mean differences between M3 and M3c SSR latencies. M3 SSRs were not significantly modified after surgery. The absence of postsurgical improvement may be due to the poor reinnervation capacity of sympathetic fibers.

Coexpression of granulocyte colony stimulating factor and its receptor in primary ovarian carcinomas.

Immunohistochemistry was used to determine the expression of granulocyte colony-stimulating factor (G-CSF) and its receptor (G-CSFR) in primary ovarian carcinomas. The expression of G-CSFR was observed in the malignant cells of each of the 46 primary carcinomas examined; G-CSF was coexpressed in both the malignant epithelial cells and the stroma of 56.5% of the specimens. Thus the majority of ovarian carcinomas harbor both potential autocrine and paracrine G-CSF axes. In 37% of the samples, G-CSF was expressed only within stromal cells, suggesting that only a potential paracrine system is in place. In a preliminary, retrospective, evaluation, the survival of patients whose tumors expressed only the apparent paracrine loop was significantly worse than patients whose tumors expressed both potential autocrine and paracrine G-CSF-based regulatory loops (14.5 vs. 42.5 months, respectively). Studies on the potential function of G-CSF were performed using the G-CSFR-expressing OVCAR-3 ovarian carcinoma line. As a single agent, rhG-CSF failed to stimulate [3H]-thymidine incorporation in these cells, but enhanced the mitogenic action of epidermal growth factor (EGF) in a dose-dependent manner. Thus, potential autocrine and/or paracrine loops involving G-CSF and its receptor occur in over 90% of primary ovarian carcinomas, and may act to modulate the action of growth factors.

Relationship between the self-administered Boston questionnaire and electrophysiological findings in follow-up of surgically-treated carpal tunnel syndrome.

A prospective study of electrophysiological examination and the Boston self-administered questionnaire (BQ) was carried out in patients with surgically-treated carpal tunnel syndrome. There were 104 hands in 93 patients (13 men and 80 women, mean age 56 years). The BQ was used to assess the severity of symptoms and function, and nerve conduction studies were done before surgical release by short incision at the palm, and at follow-ups 1 and 6 months after surgery. The BQ severity score improved or became normal in 98% of hands. The mean BQ scores and distal sensory and motor conduction velocities in the median nerve showed significant improvement at the 1 month follow-up. Further significant improvement was found at 6 months. There was no relationship between the improvements in BQ scores and the distal conduction in the median nerve. The degree of improvement in sensory and motor distal conduction velocities could be forecast from presurgical values, whereas the degree of improvement in the symptoms and the functional status after release could not be predicted from the presurgical BQ scores.

Differing temporal patterns of onset in subgroups of patients with intracerebral hemorrhage.

BACKGROUND AND PURPOSE: The purpose of this study was to further analyze the temporal patterns of onset of intracerebral hemorrhage (ICH) and to determine whether or not subgroups with specific clinical characteristics exhibit different patterns of onset. METHODS: The daily, weekly, and yearly variations in occurrence of ICH together with the relationship between ICH occurrence and changes in air temperature were evaluated in 1018 patients. Patients were grouped according to the presumed etiology of ICH: hypertensive ICH, secondary ICH, and ICH of undetermined origin. The contribution of demographic and clinical factors to the temporal distributions of ICH was also evaluated. RESULTS: Marked differences in seasonal and diurnal patterns of ICH onset were observed in the different groups. The incidence of hypertensive ICH reflected seasonal and circadian changes in blood pressure, whereas the latter did not seem related to the onset of nonhypertensive ICH. The seasonal pattern was more evident in elderly patients with hypertensive ICH than in younger subjects. No significant weekly variations were observed; however, risk was greater on Monday in the working population. CONCLUSIONS: Our results suggest that the higher incidence of ICH in the colder months is due to the effect of low temperatures on blood pressure and that the clustering of ICH events in the morning is due to the increase in sympathetic tone, and consequent increase in blood pressure, on awakening.

[Validity of schintigraphy in the study of neurogenic dysphagia]. / Validità della metodica scintigrafica nello studio della disfagia neurogena.

The purpose of the present study was to verify the validity and potential application of oropharyngealesophageal scintigraphy in the analysis of neurogenic dysphagia. Scintigraphy was used on 36 patients divided into 2 groups: Group 1 (control) comprised 17 healthy volunteers; Group 2 included 19 patients suffering from various neurological and neuromuscular pathologies (myasthenia gravis, Parkinson's disease, polymyositis, stroke, paralysis of the last cranial nerves). In group 1 scintigraphy provided normal results both for mode of swallowing and transit, and for the values of the various parameters studied. On the other hand, scintigraphy showed that in group 2 all oral, pharyngeal and esophageal phases of swallowing were altered vs the controls with a statistically significant increase in the average values for the oral transit time (OTT) (1.45 sec., p = 0.0005), pharyngeal transit time (OTT) (3.23 sec., p = 0.044), esophageal transit time (ETT) e19.87 sec., p = 0.005) as well as in the corresponding bolus retention indexes ORU (12.95%, p = 0.0003), FIR (15.05%, p = 0.0003) and ERI (28.63%, p = 0.002). Moreover, the quality and means of swallowing also proved altered while tracheobronchial aspiration was only seen in 6 of the 19 patients (maximum value: 90%, average value; 7.66%) with a marked prevalence in the stroke subgroup (4/8). In light of these results and considering the low dose of radiation (0.00043 Gy), the lack of invasiveness and excellent tolerability, scintigraphy has confirmed its clinical validity in the functional, objective and quali-quantitative study of deglutition, even in patients suffering from neurogenic dysphagia.

Diagnostic imaging of differentiated thyroid carcinoma.

The role of diagnostic imaging in differentiated thyroid carcinoma is analyzed. 99mTc-pertechnetate 123I and 131I scintigraphy allows the evaluation of nodules with their differentiation in cold (hypofunctioning) and hot (functionally autonomous) nodules; thyroid carcinomas are cold nodules even if most of them are benign. On sonography thyroid nodules are well visualized with the definition of their site, number, size (not very useful parameters for the diagnosis of malignancy), echoic structure, and vascularization on color Doppler. The sonographic findings suggestive of differentiated thyroid carcinoma are: solid and hypoechoic structure, irregular ill-defined margins, absent or discontinuous peripheral ring, microcalcification, intranodular vascularization, local lymphadenopathies. These findings are characteristic but not pathognomonic, mostly for papillary carcinoma, while in the frequently isoechoic follicular carcinoma microcalcification and lymph node metastases are rare. Only the finding, although rather infrequent, of the dissemination to adjacent structures (muscles and vessels) is a definite indication for malignancy of a thyroid nodule. Color Doppler sonography plays a major role in the postoperative staging and follow-up, in combination with thyroglobulin determination and 131I whole body scintigraphy and it allows the detection of local and/or laterocervical lymph node recurrence. The most typical sonographic findings of metastatic lymphadenopathy are the roundish shape (length/anteroposterior diameter ratio-L/A < 1.5), not visible or displaced nodal hilum, thickened cortical layer with echoic structure similar to that of thyroid parenchyma, at times with microcalcification, cortical vascularization and dismantled angioarchitecture. CT and MRI are occasionally more useful to evaluate the substernal or retrosternal extension of voluminous thyroid masses and to identify local or distant metastases.