Mechanical properties of nerve roots and rami radiculares isolated from fresh pig spinal cords

No reports have described experiments designed to determine the strength characteristics of spinal nerve roots and rami radiculares for the purpose of explaining the complexity of symptoms of medullary cone lesions and cauda equina syndrome. In this study, to explain the pathogenesis of cauda equina syndrome, monoaxial tensile tests were performed to determine the strength characteristics of spinal nerve roots and rami radiculares, and analysis was conducted to evaluate the stress-strain relationship and strength characteristics. Using the same tensile test device, the nerve root and ramus radiculares isolated from the spinal cords of pigs were subjected to the tensile test and stress relaxation test at load strain rates of 0.1, 1, 10, and 100 s^-1 under identical settings. The tensile strength of the nerve root was not rate dependent, while the ramus radiculares tensile strength tended to decrease as the strain rate increased. These findings provide important insights into cauda equina symptoms, radiculopathy, and clinical symptoms of the medullary cone.     

Treatment of rheumatoid arthritis with humanized anti-interleukin-6 receptor antibody: a multicenter, double-blind, placebo-controlled trial

OBJECTIVE: Interleukin-6 (IL-6) is a pleiotropic cytokine that regulates the immune response, inflammation, and hematopoiesis. Overproduction of IL-6 plays pathologic roles in rheumatoid arthritis (RA), and the blockade of IL-6 may be therapeutically effective for the disease. This study was undertaken to evaluate the safety and efficacy of a humanized anti-IL-6 receptor antibody, MRA, in patients with RA. METHODS: In a multicenter, double-blind, placebo-controlled trial, 164 patients with refractory RA were randomized to receive either MRA (4 mg/kg body weight or 8 mg/kg body weight) or placebo. MRA was administered intravenously every 4 weeks for a total of 3 months. The clinical responses were measured using the American College of Rheumatology (ACR) criteria. RESULTS: Treatment with MRA reduced disease activity in a dose-dependent manner. At 3 months, 78% of patients in the 8-mg group, 57% in the 4-mg group, and 11% in the placebo group achieved at least a 20% improvement in disease activity according to the ACR criteria (an ACR20 response) (P < 0.001 for 8-mg group versus placebo). Forty percent of patients in the 8-mg group and 1.9% in the placebo group achieved an ACR50 response (P < 0.001). The overall incidences of adverse events were 56%, 59%, and 51% in the placebo, 4-mg, and 8-mg groups, respectively, and the adverse events were not dose dependent. A blood cholesterol increase was observed in 44.0% of the patients. Liver function disorders and decreases in white blood cell counts were also observed, but these were mild and transient. There was no increase in antinuclear antibodies or anti-DNA antibodies. Anti-MRA antibodies were detected in 2 patients. CONCLUSION: Treatment with MRA was generally well tolerated and significantly reduced the disease activity of RA.     

Squamous Cell Carcinoma after Endoscopic Injection Sclerotherapy for Esophageal Varices

We report two cases of squamous cell carcinoma of the esophagus following endoscopic injection sclerotherapy for esophageal varices. The interval between sclerotherapy and the development of carcinoma was 24 months in case 1 and 21 months in case 2. The sclerosant was 5% sodium morrhuate in case 1 (total dose, 10 ml) and 5% ethanolamine oleate in case 2 (45.5 ml). Although no recurrent variceal bleeding occurred after sclerotherapy, we could not perform any curative surgical treatment for esophageal cancer because of the advanced stage of the cancer and the severity of the accompanying liver dysfunction. It is difficult to determine the relationship between sclerotherapy and carcinoma; however, long-term surveillance is essential to avoid overlooking a neoplasm in the esophagus after endoscopic injection sclerotherapy.     

Cervical ossification of the posterior longitudinal ligament: Biomechanical analysis of the influence of static and dynamic factors

Objective

Cervical myelopathy due to ossification of the posterior longitudinal ligament (OPLL) is induced by static factors, dynamic factors, or a combination of both. We used a three-dimensional finite element method (3D-FEM) to analyze the stress distributions in the cervical spinal cord under static compression, dynamic compression, or a combination of both in the context of OPLL.

Methods

Experimental conditions were established for the 3D-FEM spinal cord, lamina, and hill-shaped OPLL. To simulate static compression of the spinal cord, anterior compression at 10, 20, and 30% of the anterior–posterior diameter of the spinal cord was applied by the OPLL. To simulate dynamic compression, the OPLL was rotated 5°, 10°, and 15° in the flexion direction. To simulate combined static and dynamic compression under 10 and 20% anterior static compression, the OPLL was rotated 5°, 10°, and 15° in the flexion direction.

Results

The stress distribution in the spinal cord increased following static and dynamic compression by cervical OPLL. However, the stress distribution did not increase throughout the entire spinal cord. For combined static and dynamic compression, the stress distribution increased as the static compression increased, even for a mild range of motion (ROM).

Conclusion

Symptoms may appear under static or dynamic compression only. However, under static compression, the stress distribution increases with the ROM of the responsible level and this makes it very likely that symptoms will worsen. We conclude that cervical OPLL myelopathy is induced by static factors, dynamic factors, and a combination of both.     

Acid and duodenogastroesophageal reflux after esophagectomy with gastric tube reconstruction

OBJECTIVE: Patients who undergo esophagectomy with gastric tube reconstruction incur increased risk for acid reflux and duodenogastroesophageal reflux. Few postesophagectomy studies of gastroesophageal reflux disease have included simultaneous 24-h pH and bilirubin monitoring. The aim of this study is to evaluate acid reflux and duodenogastroesophageal reflux after esophagectomy with gastric tube reconstruction. METHODS: Reflux symptom evaluation, endoscopy, and simultaneous 24-h pH and bilirubin monitoring in the cervical esophagus were performed in 25 patients who underwent Ivor Lewis esophagectomy, intrathoracic esophagogastrostomy, and digital dilation of the pyloric ring as treatment for esophageal cancer. RESULTS: Reflux symptoms were severe, mild, and absent in 2, 7, and 16 patients, respectively. Reflux esophagitis and Barrett's esophagus was observed in 11 and 1 patients, respectively. Elevated acid reflux occurred in 7 patients (28%). Elevated duodenogastroesophageal reflux was recorded in 11 patients (44%). Reflux profile analysis identified three patterns: 4 subjects (16%) with both elevated acid reflux and duodenogastroesophageal reflux; 3 (12%) with only elevated acid reflux; and 7 (28%) with only elevated duodenogastroesophageal reflux. Of 7 patients with only elevated duodenogastroesophageal reflux, 4 developed reflux esophagitis. Although reflux symptoms did not correlate with endoscopic esophagitis, a significant correlation was observed between endoscopic esophagitis and acid reflux and/or duodenogastroesophageal reflux. CONCLUSIONS: Reflux symptoms represented a poor indication of esophagitis in patients with esophagectomy and gastric tube reconstruction. Simultaneous 24-h pH and bilirubin monitoring can help in identifying patients at high risk for reflux esophagitis, as well as indicating the cause of esophagitis.     

Risk factors for a prolonged operative time in a single-incision laparoscopic cholecystectomy

Background: A prolonged operative time is associated with adverse post-operative outcomes in laparoscopic surgery. Although a single-incision laparoscopic cholecystectomy (SILC) requires a longer operative time as compared with a conventional laparoscopic cholecystectomy, risk factors for a prolonged operative time in SILC remain unknown.Methods: A total of 20 clinical variables were retrospectively reviewed to identify factors for a prolonged operative time (longer than 3 h) in a total of 220 consecutive patients undergoing SILC.Results: The median operative time was 145 min (range, 55–435) and a prolonged operative time was required in 62 patients (28%). Independent factors that predict a prolonged operative time as identified through multivariate analysis were body mass index (BMI) (P = 0.009), acute cholecystitis (P < 0.001) and operator (resident or staff surgeon) (P < 0.001). Furthermore, a prolonged operative time was significantly associated with an increased amount of intra-operative blood loss (P < 0.001) and a prolonged stay after surgery (P < 0.001).Conclusions: These findings suggest that a higher BMI, acute cholecystitis and a resident as an operator significantly increase the duration of SILC procedures.     

Notch Signaling May Be Involved in the Abnormal Differentiation of Epidermal Keratinocytes in Psoriasis

Localization of each keratin isoform differs among epidermal layers. Proliferating basal cells synthesize keratin 14 (K14) and suprabasal cells express keratin 10 (K10) in normal skin. Notch signaling is essential for keratinocyte differentiation. Notch1 is expressed in all epidermal layers, Notch2 in the basal cell layer and Notch3 in basal cell and spinous cell layers in normal epidermis. It has been poorly elucidated how localization and expression levels of Notch molecules are related to epidermal molecular markers K10 and K14 in psoriatic skin with abnormal differentiation of epidermal tissue. This study aimed to investigate the relationship between abnormal differentiation of epidermal cells in psoriatic skin and expression of Notch molecules. We investigated keratins (K14 and K10) and Notches (1, 2, 3 and 4) using immunohistochemistry in psoriatic skin (n=30) and normal skin (n=10). In normal skin, K14 and K10 were discretely observed in the basal cell layer and suprabasal layer, respectively. In psoriatic skin, K14 was expressed in the pan epidermal layer while it and K10 were co-expressed in some middle suprabasal layer cells. Notch1, 2, 3, and 4 localized in all epidermal layers in normal skin. In psoriatic skin, Notch1, 2, and 4 mainly localized in suprabasilar layers and Notch3 is lacalized in pan epidermal, suprabasilar, and basilar layers. Protein and mRNA of Notch1, 2, and 3 isoforms decreased in psoriatic epidermis compared with normal epidermis. These data suggest that decrements in these Notch molecules might cause aberrant expression of K10 and K14 leading to anomalous differentiation of the epidermis in psoriatic lesions.