Mechanical environment of the supraspinatus tendon: three-dimensional finite element model analysis

BACKGROUND: We analyzed the mechanical environment of the supraspinatus tendon using a three-dimensional finite element model with the software programs MENTAT and MARC. METHODS: The supraspinatus tendon that attaches to the superior facet was extracted and modeled. The geometric shape of the humeral head was determined from computed tomography images, and the shape of the supraspinatus tendon was determined from magnetic resonance images of the shoulder at 0 degrees of abduction in a healthy 27-year-old man. The distal portion of the humeral head was fixed, and 10 N of tensile force was applied to the proximal end of the tendon. The tensile stress was calculated. RESULTS: The tensile stress was 1.8 MPa for the bursal side and 15.0 MPa for the articular side of the anterior portion of the supraspinatus tendon. The intensity was 0 MPa for the bursal side and 4.5 MPa for the articular side of the middle portion of the tendon. The intensity was 0.1 MPa for the bursal side and 5.2 MPa for the posterior edge of the tendon. CONCLUSIONS: Based on the three-dimensional finite element method, the maximal tensile stress was observed on the articular side of the anterior edge of the supraspinatus tendon. Our result may explain the frequent occurrence of rotator cuff tears at this site.     

Reversal of Portosystemic Encephalopathy after Endoscopic Embolization of Recurrent Gastroesophageal Varices

Chronic portosystemic encephalopathy (CPSE) due to a shunt via gastroesophageal varices is uncommon. We were able to control a case of CPSE due to recurrent gastroesophageal varices using endoscopic embolization (EE). A 68-year-old man presented at our hospital in a confused, apathetic and tremulous state. He had undergone devascularization, proximal gastric transection and splenectomy for esopha-geal varices due to liver cirrhosis 16 years previously. The patient had hyperammone-mia (228 µg/dl), and endoscopic examination revealed nodular cardiac varices and large recurrent esophageal varices. Superior mesenteric arterial portography revealed that a large volume of superior mesenteric venous blood drained into the cardiac and esophageal varices through the remnant left gastric vein. The plasma ammonia level in the esophageal varices taken at the time of EE was 419 pg/dl, which was a much higher level than that of peripheral vessels, the superior vena cava and azygos vein, and suggested that the encephalopathy was due to the portosystemic shunt via the gastroesophageal varices. EE was performed using 5% ethanolamine oleate with iopamidol under fluoroscopy. The esophageal and cardiac varices were successfully embolized, the CPSE disappeared, and the plasma ammonia level decreased to 27 pg/dl. No complications were observed, and the patient was discharged on day 37 after EE. We conclude that EE is an effective and safe treatment for CPSE due to gastroesophageal varices.     

Mouse Homologue of the Human SART3 Gene Encoding Tumor-rejection Antigen

We recently isolated a human SART3 ( hSART3 ) gene encoding a tumor-rejection antigen recognized by HLA-A2402-restricted cytotoxic T lymphocytes (CTLs). The hSART3 was also found to exist as an RNA-binding nuclear protein of unknown biological function. In this study, we cloned and analyzed the homologous mouse SART3 ( mSART3 ) gene in order to understand better the function of hSART3, and to aid in establishing animal models of specific immunotherapy. The cloned 3586-bp cDNA encoded a 962-amino acid polypeptide with high homology to hSART3 (80% or 86% identity at the nucleotide or protein level, respectively). Nonapeptides recognized by the HLA-A2402-restricted CTLs and all of the RNA-binding motifs were conserved between hSART3 and mSART3. The mSART3 mRNA was ubiquitously expressed in normal tissues, with low level expression in the liver, heart, and skeletal muscle. It was widely expressed in various organs from as early as day 7 of gestation. mSART3 was mapped to chromosome 5, a syntenic region for human chromosome 12q23–24, and its genomic DNA extended over 28-kb and consisted of 19 exons. This information should be important for studies of the biological functions of the SART3 protein and for the establishment of animal models of specific cancer immunotherapy.     

Establishment of local diagnostic reference levels for quality control in intraoral radiography

Objective

To investigate the dosage and imaging conditions for patients undergoing intraoral radiography at Meikai University Hospital and establish assurance and quality control data.

Methods

Tube voltage, exposure time, and air kinetic energy released per unit mass (air kerma) of three intraoral radiography units were measured. To calculate the patient entrance dose (PED) for each radiograph using Insight film, we extracted data for 1063 patients from their exposure records. The PED was compared with the diagnostic reference level (DRL) from the European Commission and the UK.

Results

The tube voltage of the three units was maintained at 60 ± 2 kV. Differences in exposure time were less than 1.7 % for all units. The air kerma rates were well maintained within a 4.2 % error. Based on the patient data, there were no significant differences in the mean exposure times for males and females for all anatomical sites. The mean PED ranged from 1.09 ± 0.31 mGy for the mandibular incisors to 2.42 ± 0.33 mGy for the maxillary molars. The mean PED at the mandibular molars using InSight film was 1.59 ± 0.20 mGy, being less than the recommended value based on the DRL for intraoral radiography in the UK.

Conclusions

We concluded that radiographic conditions at the hospital have been properly maintained. This basic quality control data may assist other dental radiation facilities to reduce patient dosage.

     

Superior mesenteric artery syndrome treated with single‐incision laparoscopy‐assisted duodenojejunostomy

Superior mesenteric artery (SMA) syndrome is an uncommon disease resulting from compression and partial obstruction of the third portion of the duodenum from the SMA. A 77‐year‐old man, who did not have a history of surgery, experienced repeated vomiting and developed abdominal distension. Abdominal CT showed a narrowed third portion of the duodenum, with a distended stomach and proximal duodenum. The patient was diagnosed as having SMA syndrome and was initially treated conservatively, but his condition did not improve. Single‐incision laparoscopy‐assisted duodenojejunostomy was performed. The patient recovered well and was discharged from hospital on postoperative day 8. Laparoscopic treatment is feasible for the treatment of SMA syndrome given its safety and minimal invasiveness. This is a report of the first case of single‐incision laparoscopy‐assisted duodenojejunostomy. This procedure is safer and less invasive than a conventional laparoscopic approach in a patient with SMA syndrome.     

Vascular pedicled jejunal Roux-en-Y reconstruction with supercharge technique for necrosis of the gastric tube following subtotal esophagectomy

Necrosis of the esophageal conduit is a life-threatening complication in esophageal cancer surgery, and secondary reconstruction options for esophageal discontinuity are quite limited. We present a procedure in which we used a long-segment jejunal flap with a supercharged vascular pedicle to treat gastric tube necrosis following subtotal esophagectomy in a 64-year-old man with esophageal cancer. The proximal jejunal flap was pulled up in Roux-en-Y fashion through the subcutaneous route together with the vascular pedicle of the fourth branch of the jejunal vessels, and the cut edges of the second jejunal vessel were anastomosed microscopically to the internal thoracic vessels for supercharging. No problems occurred with either vessel or digestive tract anastomosis. The patient was able to commence oral intake on postoperative day (POD) 10, was discharged on POD 37, and obtained a good quality of life at home. This result suggests that supercharged vascular pedicled jejunum is a suitable alternative conduit for secondary reconstruction following necrosis of the esophageal conduit in esophageal cancer surgery.     

Contact between the glenoid and the humeral head in abduction, external rotation, and horizontal extension: a new concept of glenoid track

To date, no anatomic or biomechanical studies have been conducted to clarify what size of a Hill-Sachs lesion needs to be treated. Nine fresh-frozen cadaveric shoulders were tested in a custom device. With the arm in maximum external rotation, horizontal extension, and 0 degrees, 30 degrees, and 60 degrees of abduction, the location of the entire rim of the glenoid was marked on the humeral head using a Kirschner wire. The distance from the contact area to the footprint of the rotator cuff with the arm in 60 degrees of abduction was measured by a digital caliper. With an increase in arm elevation, the glenoid contact shifted from the inferomedial to the superolateral portion of the posterior aspect of the humeral head, creating a zone of contact (glenoid track). The medial margin of the glenoid track was located 18.4 +/- 2.5 mm medial from the footprint, which was equivalent to 84% +/- 14% of the glenoid width. A Hill-Sachs lesion has a risk of engagement and dislocation if it extends medially over the medial margin of the glenoid track.     

Therapeutic benefits of intrathecal protein therapy in a mouse model of amyotrophic lateral sclerosis

When fused with the protein transduction domain (PTD) derived from the human immunodeficiency virus TAT protein, proteins can cross the blood-brain barrier and cell membrane and transfer into several tissues, including the brain, making protein therapy feasible for various neurological disorders. We have constructed a powerful antiapoptotic modified Bcl-X(L) protein (originally constructed from Bcl-X(L)) fused with PTD derived from TAT (TAT-modified Bcl-X(L)), and, to examine its clinical effectiveness in a mouse model of familial amyotrophic lateral sclerosis (ALS), transgenic mice expressing human Cu/Zn superoxide dismutase (SOD1) bearing a G93A mutation were treated by intrathecal infusion of TAT-modified Bcl-X(L). We demonstrate that intrathecally infused TAT-fused protein was effectively transferred into spinal cord neurons, including motor neurons, and that intrathecal infusion of TAT-modified Bcl-X(L) delayed disease onset, prolonged survival, and improved motor performance. Histological studies show an attenuation of motor neuron loss and a decrease in the number of cleaved caspase 9-, cleaved caspase 3-, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells in the lumbar cords of TAT-modified Bcl-X(L)-treated G93A mice. Our results indicate that intrathecal protein therapy using a TAT-fused protein is an effective clinical tool for the treatment of ALS.     

Clinical applications of imaging reconstruction by virtual sonography]

AIM: One of the pitfalls in managing multiple liver tumors is the difficulty in identifying individual tumors on ultrasonography. Computed tomography (CT)-assisted virtual sonography has been shown to improve sonographic diagnosis, however it requires additional equipment and software. We have developed a simple reconstruction method of virtual sonography (SRVS). METHODS: We reconstructed SRVS mimicking ultrasonographic images, utilizing a workstation software attached to a multi-detector row CT system without any additional program. RESULTS: We have performed SRVS in 32 patients with 41 liver tumors that could hardly be identify on ultrasonography. SRVS assisted the identification of malignant form non-pathologic ones and thereby contributed to the appropriate clinical strategy including RFA (18 tumors), liver biopsy (2 tumors), other therapies (4 tumors) and follow-up (17 tumors). CONCLUSION: We have developed virtual sonography using conventional CT software. SRVS seems useful in the clinical practice in managing liver tumors.     

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.