Biomedical subjects
Publications and source records attributed to T Natsume.
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Clinical blood pressures measured at clinic by physician were higher than home blood pressures measured at home by patients in the majority of untreated patients with essential hypertension, but equivalent or lower in some patients. Clinic minus home blood pressure (delta P) were correlated with the levels of clinic blood pressure (r = 0.51, p less than 0.005 for systolic; r = 0.35, p less than 0.02 for diastolic blood pressure, respectively). The systolic delta P might be greater in the middle-aged women, especially in the fifties of females than the age-matched males (p less than 0.05). The delta P could not be altered by any antihypertensive drugs with the exception of systolic delta P with diuretic alone. The blood pressure tended to remain more stable throughout the 24-hour period in proportion as the severity of hypertension increased. The observation of circadian variation in blood pressure disclosed that the blood pressure was lower in the morning, but increased gradually, resulting in the relatively high blood pressure between the afternoon and evening in the low renin and volume expanded type of hypertension. On the contrary, the blood pressure was already high in the early morning in hypertensive patients characterized by the accelerated renin-angiotensin system and contracted volume factor.
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A case with ruptured aneurysm of the sinus of Valsalva into the right atrium directly visualized by cross-sectional echocardiography was reported. A 31-year-old male was referred to our hospital for evaluation of recently developed cardiac murmur. A systolic ejection murmur and diastolic blowing murmur were audible maximally at 3-4L and the latter one was also well audible at the right lower sternal border. Cardiac catheterization data revealed a large left-to-right shunt at the atrial level. The cross-sectional echocardiogram, obtained with a transducer at 5R towards the upwards and the medial direction, revealed a mass echo showing a pendulous motion through cardiac cycle in the right atrial cavity. Ruptured aneurysm of the sinus of Valsalva originated from the non-coronary sinus was demonstrated by aortography, and it showed the same motion as in echocardiography. From this angiographic finding and its disappearance after operation, the mass visualized by echocardiography was considered to be ruptured aneurysm itself. Thus, direct visualization of ruptured aneurysm of the sinus of Valsalva into the right atrium, as well as other types, was possible by cross-sectional echocardiography. In addition, multiple coronary A-V fistulae with a small shunt were demonstrated by coronary angiography in this case. Clinical significance of the complication has not been clarified.
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Major and minor axes of the left ventricle were measured by single beam echocardiography in ten cardiac patients and the measurements and calculated volumes by formula V=pi/6 D2 were compared with the angiocardiographic estimates. There was a favorable correlation between echocardiographic and angiocardiographic major axis dimention (r=0.79), left end-diastolic volume (r=0.96), and ejection fraction (r=0.81). On the contrary, left end-diastolic volume calculated by formula V=D3 was less correlated with angiocardiographic estimates (r=0.93) and the former had a tendency to overestimate the volumes where D exceeded 6.5 cm. These data indicate that in cases with markedly enlarged left ventricle, the use of formula V=pi/6 D2L is a more accurate predictor of volumes than formula V=D3.
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An artificial esophagus was fabricated from a collagen-coated silicone tube 5 cm long, with an inner diameter of 2.5 cm and a wall thickness of 1 mm. The outer surface was coated with dry collagen to 5 mm thickness. The bilayered prosthesis was anastomosed to the cervical esophagus of adult mongrel dogs that were fed only by intravenous hyperalimentation (IVH) with 80 cal/kg/day and 60 ml water/kg/day for 3 weeks after the operation. Once the dogs began to consume food orally, the artificial esophagus dropped spontaneously into the stomach and formation of the neoesophagus was complete. Macroscopically, the neoesophagus showed no evidence of leakage or inflammation and had a smooth internal surface, but it developed slight segmental narrowing. Microscopically, layers of stratified squamous epithelium covered the neoesophagus within 3 to 4 weeks. The most characteristic feature of the artificial esophagus was that the replacement prosthesis did not remain in the esophagus after healing. Esophageal epithelization extended into the collagen layer coating the silicone tube and a new esophageal lumen was regenerated, thereby decreasing the chance of infection and leakage. However, neoesophageal stenosis was observed when the silicone tube was removed.
BACKGROUND/AIMS: This study evaluated the drainage area of the capitular branches of the pancreas head by computed tomography under endoscopic retrograde pancreatography (ERP-CT). METHODOLOGY: ERP-CT was performed in 43 patients. The drainage area of the capitular branches of Wirsung's and Santorini's ducts were evaluated by dividing the pancreatic head into two areas, the anterior area and the posterior area. RESULTS: The pancreatic duct pattern was classified in 4 types; normal type, ansa type, loop type, and embryonic type. In normal type duct pattern, all inferior capitular branches of Wirsung's duct drained the posterior area and all inferior capitular branches of Santorini's duct drained the anterior area. In ansa type duct pattern, all inferior branches from Wirsung's duct drained the posterior area and inferior branches from Santorini's duct drained the anterior area and the posterior area. In loop type duct pattern, all inferior branches from Santorini's duct drained the posterior area and inferior branches from Wirsung's duct drained the anterior area and the posterior area. Middle capitular branches were detected only in normal B, normal C, and loop type. CONCLUSIONS: ERP-CT is a useful procedure that provided three-dimensional morphology of the capitular branch of the pancreas head.
Vascular endothelial growth factor (VEGF) is known as a potent inducer of angiogenesis in various human cancers. Serum VEGF concentrations of colorectal cancer patients was assessed for their clinical significance as a tumor marker. Serum samples were obtained at admission from 24 healthy volunteers and 111 patients with colorectal cancer. Preoperative serum VEGF concentrations, which are significantly higher than those of healthy controls, reflect clinical stage progression, depth of invasion, liver metastasis, lymph node metastasis and lymphatic invasion. Consequently, detection of VEGF could serve as a clinically useful marker for colorectal cancer progression and metastasis independent of other markers.
The efficiency of a new tracheal prosthesis was studied. The prosthesis consists of fine Marlex mesh reinforced with a continuous Teflon spiral, and it is grafted and coated with pig collagen, with the aim of promoting connective tissue infiltration and providing air-tightness during the initial stage of implantation. Complete surgical resection and replacement of a 4-6 tracheal ring segment of the cervical trachea was performed in 13 adult mongrel dogs. Except for two dogs that developed anastomotic insufficiency, the prostheses in all dogs were infiltrated by the surrounding connective tissue, and were completely incorporated by the host trachea at the anastomotic sites. Formation of respiratory epithelium that lined the prosthesis lumen, was seen to varying degrees, and in one dog killed at 4 months after reconstruction, this was confirmed histologically from the upper to the lower anastomosis of the prosthesis. Stenosis of the lumen often occurred, however, due to deformation of the prosthesis and overgrowth of granulation tissue. The authors conclude that this tracheal prosthesis is highly biocompatible, and might be useful for repairing tracheal defects by improving prosthesis processing, especially that used for insertion of stents.
Preliminary results, obtained using an artificial esophagus combined with autologous mucosal cells in dogs, are reported. The authors' prosthesis is a silicone tube coated with freeze dried collagen sponge. Cells infiltrate this collagen layer and synthesize new tissue, which will become the neoesophagus. The silicone tube imparts rigidity to the prosthesis and prevents infection, leakage, and dislocation of the prosthesis at the anastomotic site. After formation of the epithelized neoesophageal lumen, the silicone tube drops into the stomach as the result of peristalsis in response to food. Eventually, no artificial prosthesis remains in place, and the defect is replaced by ingrowing tissue. This process was shortened by mucosal cell seeding. Before replacement, the authors harvested oral mucosal (OM) cells, cultured them for 10 days, and seeded them in the collagen layer of the prosthesis just after anastomosis. The neo-esophageal lumen was formed 1 week after the operation without any local complications, infection, leakage, or stenosis, and 2 weeks later the firm, epithelized neoesophagus was completed. OM cell seeding accelerated not only epithelization, but also regeneration of mesenchymal tissue. Parallel with this, transmission electron microscopy showed that most of the cells in the neoesophagus exhibited large nuclei and prominent rough endoplasmic reticulum, indicative of active collagen production.
The authors studied the efficacy of a new tracheal prosthesis made from mesh. The prosthesis, 50 mm long and 18-22 mm in diameter, is made from a Marlex mesh cylinder reinforced with a continuous polypropylene spiral that is grafted and coated with porcine collagen to increase its biocompatibility and provide an airtight seal during the initial implantation stage. Circumferential surgical resection and replacement of a seven to nine ring segment of the cervical trachea was performed in 20 adult mongrel dogs. At the time of surgery, a silicone tube was inserted into the tracheal prosthetic lumen to promote secretory transportation until the prosthesis was covered with host tissue. The silicone tube was removed during fiber bronchoscopy 1 month after surgery. With the exception of the prostheses in 3 dogs that died of unrelated causes, all were infiltrated by connective tissue and incorporated completely by the host. One of these 17 dogs died of suffocation caused by luminal stenosis 2.5 months after surgery, but the others survived until they were killed at more than 6 months. The luminal surfaces of the reconstructed tracheae were covered with respiratory epithelium to varying degrees, and in one dog killed at 22 months after surgery, confluent epithelization throughout the length of the prosthesis was confirmed histologically. In eight dogs, prosthetic luminal stenosis occurred because of overgrowth of granulation tissue, which generally was mild in all but three dogs. The authors conclude that this tracheal prosthesis is highly biocompatible and shows promise for clinical application.
This study investigated ways of preventing late stenosis after replacing the esophagus with a prosthetic device and increasing survival time in an animal model. In a previous study, the authors induced neoesophageal formation and re-epithelialization at an early stage, although stenosis in the chronic stage remained a problem, and long-term survival was prevented. The authors developed an artificial esophagus made from a collagen-silicone composite tube. The silicone tube (25 mm in diameter, 50 mm long, and 1 mm thick) was covered with collagen sponge (5 mm thick). The collagen sponge was intended to be replaced by host tissue, leading to neoesophageal regeneration. The authors thought stenosis was caused primarily by poor regeneration of submucosal tissue, rather than reepithelialization. Thus, they examined the grade of stenosis relative to the time the stent became dislodged. They concluded that the occurrence of stenosis after anastomosis depends upon the duration of stenting and that stenosis did not develop when the portion replaced by the artificial esophagus was stented for at least 4 weeks.