Cyclic mechanical stretch stress increases the growth rate and collagen synthesis of nucleus pulposus cells in vitro

STUDY DESIGN: A rabbit model designed to investigate the effects of applied cyclic tensile stress on the cell division rate and the collagen synthesis in the rabbit nucleus pulposus cells in vitro. OBJECTIVE: To evaluate the effects of mechanical stress on nucleus pulposus cells, thus adding to the understanding of the adaptation of the intervertebral disc to mechanical stress. SUMMARY OF BACKGROUND DATA: Intervertebral disc cells in vivo are exposed to a multitude of physical forces during physical motion. Although it is known that in intervertebral disc disease, a common pathway of disc degeneration is mechanical stress on the nucleus pulposus or the anulus fibrosus or both, the underlying mechanism has been less well defined. METHODS: Nucleus pulposus cells were isolated from 4-week-old Japanese white rabbits. These cells were subjected to the mechanical cyclic stretch stress using a computerized, pressure-operated instrument that physically deformed the cells. The DNA synthesis rate, collagen synthesis rate, and cell cycle progression were measured. RESULTS: Cyclic tensile stretch increased the DNA synthesis rate in nucleus pulposus cells and in the population of cells in the S phase of the cell cycle during 1 to 2 days of subjugation to stress. Cyclic tensile stretch also increased collagenous protein synthesis in nucleus pulposus cells during 1 to 4 days of stress. CONCLUSIONS: Mechanical stress on nucleus pulposus cells promotes the proliferation of cells and alters the properties of intervertebral disc cells. This study may reflect the adaptation of the intervertebral disc to increased motion and stress.     

Functional MR imaging with venography for neurosurgical identification of the central sulcus

We evaluated the applicability of functional MR imaging overlaid onto brain images superimposed venography for neurosurgical identification of the central sulcus. In 20 volunteers and 12 patients with brain tumors located around the sensorimotor cortex, gradient echo and large flip angle functional MR image was performed to allow visualization of flow effect and susceptibility related changes in relative large vein by motor hand task. Functional MR image acquired was overlaid on 3D anatomical image with 3D venography. Based on the 3D mapping, intra-operative cortical somatosensory evoked potentials (SEPs) were recorded. The significant activation area obtained from functional MR imaging was projected on an ascending cortical vein in 16 volunteers (80%) and 10 patients (83%). Comparing the anatomical activation map with visual inspection of the exposed cortical surface made it easy to identify the activation area during surgery. The cortical veins in 9 of 10 were validated as a central vein by intra-operative cortical recording of SEPs. Combination of functional MR imaging overlaid onto 3D anatomical image with venography and intra-operative SEPs permitted rapid and accurate localization of the central sulcus during surgery.     

Patil-Syracuse mask for fiberoptic intubation

Patil-Syracuse mask, recently introduced in Japan, has a port for fiberscopy. A fiberoptic bronchoscope and an endotracheal tube can be passed through the port with little air leakage. Positive pressure ventilation can be continuously maintained using this mask during fiberoptic intubation. This mask is particularly useful when a patient can be easily ventilated through a face mask but the trachea is unexpectedly difficult to intubate. With a modified endoscopy mask technique, the mean expiratory tidal volume of 10 ml.kg-1 could be obtained during fiberoptic orotracheal intubation. We describe a fiberoptic intubation technique using this mask, and discuss the complications and limitations of this method.     

Laparoscopic cholecystectomy using a newly developed laparoscope manipulator for 10 patients with cholelithiasis

Background Laparoscopic surgery has continued to gain popularity in almost all fields of abdominal surgery, and robotic systems have been introduced in general surgery. Naviot is a new remote-controlled laparoscope manipulator system controlled by the operator’s hand. This study assessed its introduction into clinical practice. Methods A group of 10 consecutive patients with cholelithiasis underwent laparoscopic cholecystectomy assisted by the Naviot system (Naviot group). Another group of 41 patients who underwent laparoscopic cholecystectomy with a conventional human camera holder (human camera group) were selected for a comparison of their operative results with those of the Naviot group. Results The operative time of 89.3 ± 27.1 min for the Naviot group was significantly longer than that of 74.8 ± 28.1 min for the human camera group (p < 0.05). However, when the setup time for the Naviot system was excluded, the operative time was not significantly different from that for the human camera group. Other operative results showed no significant difference between the two groups. Conclusions The authors believe that the new Naviot system is feasible for clinical use, and that it enables surgeons to perform solo gastrointestinal surgery.     

Evaluation of the epidermal growth factor receptor gene mutation and copy number in non-small cell lung cancer with gefitinib therapy

Several studies have suggested that epidermal growth factor receptor (EGFR) gene mutation, EGFR gene amplification, and some other biomarkers may be predictors of gefitinib sensitivity. We analyzed EGFR mutation and EGFR copy number in 22 gefitinib-treated non-small cell lung cancer (NSCLC) cases and their relation to the survival of patients. We also studied 143 gefitinib-na?ve Japanese NSCLC cases. The erbB2 copy number was also studied in 59 gefitinib-na?ve NSCLC cases. In gefitinib-treated patients, the presence of EGFR mutation was associated with a higher response rate to gefitinib and a longer overall survival, but the increased EGFR gene copy number was not. In gefitinib-na?ve cases, EGFR mutation but not EGFR gene copy number was significantly correlated with gender, pathological subtypes, and smoking status. The erbB2 copy number was not significantly correlated with the EGFR mutation or EGFR copy number in 59 cases. In conclusion, EGFR mutation was a better predictor of clinical outcome in gefitinib-treated patients than the EGFR gene copy number.     

The effect of Sairei-to on oxygen-induced retinal neovascularization in the neonatal rat

PURPOSE: To study the effect of Sairei-to (ST), a Japanese traditional medicine, on oxygen-induced retinopathy (OIR) in rats. METHODS: OIR was induced by maintaining Sprague-Dawley neonatal rats in 80% oxygen for 12 days. The rats were treated once daily with oral administration of 0.75 g/kg (n = 9), 1.5 g/kg (n = 13) of ST in water, or water alone (WA, n = 13) at 5 mL/ kg body weight from day 6 to day 17. On day 18, retinal samples were collected. Retinal neovascularization (NV) was assessed by the NV score, and by the percentage of avascular area (% AVA), using a method previously reported. The number of severe retinal NV cases (NV > or = 9) was compared. The retinal vascular endothelial growth factor (VEGF) concentrations were measured with an immunoassay kit, at 0, 12, 24, 72 and 144 hours after oxygenation. RESULTS: NV score and % AVA decreased in the ST treated group compared to the WA group. However, severe NV was seen in five cases of WA and in one case of the ST treated group. Thus severe NV was inhibited significantly by ST treatment (p = 0.0185). Retinal VEGF did not differ between groups at any time points. CONCLUSION: These data suggest that severe NV in OIR is inhibited by ST treatment.     

Physical activity and colorectal cancer: the Fukuoka Colorectal Cancer Study

The number of cases of colorectal cancer in Japan has increased over the past few decades, and incidence rates are now among the highest in the world. The present investigation within the Fukuoka Colorectal Cancer Study, including 778 cases and 767 controls aged 20-74 years, examined the association between physical activity and colorectal cancer risk by subsite. Employment-associated and leisure time physical activity was assessed by a questionnaire and interview. Division of sites into the proximal and distal colon, as well as the rectum, revealed clear site-dependent protective effects, with adjustment for smoking, alcohol consumption, BMI and age. In males, greater job-related physical activity was associated with significant reduction of risk in the distal colon and rectum (P = 0.047 and 0.02, respectively), whereas total and moderate or hard non-job physical activity exerted effects limited to the rectum (P = 0.01 and 0.004, respectively). In females, job-related physical activity and moderate or hard non-job physical activity was also protective, but only in the distal colon. Separate assessment of the influence of BMI 10 years previous to the study showed increase in risk with obesity in males but not in females, limited to distal colon and rectum. The results of the present study indicate that physical activity associated with work and leisure-time exerts beneficial effects in Japanese, but not on the proximal colon.     

Pleiotropic effects of nifedipine on atherosclerosis

Impaired endothelial cell (EC) growth and function have been proposed to be an initial event that leads to the development of atherosclerosis. There is a growing body of evidence that atherosclerosis is an inflammatory-fibroproliferative disease, and ECs are target for cytokines and growth factors released during inflammation. Recently, nifedipine, one of the most widely used dihydropyridine-based calcium antagonists (DHPs) for treatments of patients with hypertension, was shown to inhibit vascular inflammation and subsequently improve endothelial function in many cardiovascular diseases, thus slowing the development and progression of atherosclerosis. However, the molecular mechanisms underlying this are not fully understood, because ECs do not possess voltage-operated L-type calcium channels. In this review, we discuss the pleiotropic effects of nifedipine on atherosclerosis, especially focusing on its anti-oxidative properties.     

Anticoagulant-induced pseudothrombocytopenia occurring after transcatheter arterial embolization for hepatocellular carcinoma

Pseudothrombocytopenia (PTCP) is the in vitro phenomenon of anticoagulant-activated platelet agglutination that results in spuriously low platelet counts. We report the case of a 65-year-old man with EDTA- and sodium citrate-dependent PTCP occurring after transcatheter arterial embolization (TAE) for hepatocellular carcinoma (HCC) due to hepatitis C cirrhosis. Invasion of the portal and hepatic veins by HCC formed severe trans-tumoral arterio-venous shunts that were effectively treated by TAE. Two days after the therapy, PTCP was seen on blood count and continued for 4 months. The patient received unnecessary treatment for disseminated intravascular coagulation (DIC) until the diagnosis of PTCP was established. PTCP is a rare complication but should be considered after TAE for HCC; lack of recognition may lead the physician to misdiagnosis and patient mismanagement.     

Expression and mutation statuses of epidermal growth factor receptor in thymic epithelial tumors

BACKGROUND: Epidermal growth factor receptor (EGFR) gene mutations have been reported to correlate with the sensitivity to the tyrosine kinase inhibitor treatment for advanced lung cancers. Since several reports have shown that invasive thymoma overexpress the EGFR protein, we examined the EGFR expression and mutation statuses in thymoma and thymic carcinoma tissues. METHODS: EGFR mutation statuses from 99 thymic epithelial tumor samples were evaluated by a rapid and sensitive TaqMan assay using Applied Biosysytems 7500 real-time PCR system. Probes were designed according to the 13 different EGFR mutations reported previously in lung cancers. A total of 38 thymoma samples were directly sequenced for the EGFR gene. Protein expressions were evaluated for 56 thymic epithelial tumors by immunohistochemistry. RESULTS: EGFR gene mutations were not detected in any of the thymoma and thymic cancer samples using TaqMan PCR assay. Of the 38 samples 3 showed a heterozygous silent mutation without changes in the protein, a G to A transition at the nucleotide 2361 in exon 18. EGFR expression was significantly higher in invasive thymomas (stages III-IV, 15/19 were positive) than in early stage thymomas (stages I-II, 7/33 were positive) (P < 0.0001). All four carcinomas and all seven B3 thymomas showed EGFR positive staining. CONCLUSIONS: Although EGFR mutation at the tyrosine kinase domain is unlikely to be a therapeutic target for thymoma, the information about EGFR expression would contribute to the further identification of the therapeutic target for advanced thymomas.