To investigate whether muscle fiber conduction velocity reflects muscle fiber type, we studied the extensor digitorum longus (EDL) and soleus (SOL) muscle in 7 male rats aged 12 weeks. Muscle fiber conduction velocity was measured with a surface electrode array during stimulated contraction and calculated from the delay between two action potentials along muscle fibers for a given inter-electrode distance. Conduction velocity in the EDL (2.71±0.50 m/s) was significantly higher (p<0.05) than that in the SOL (2.14±0.34 m/s) . Fiber type, fiber area and fiber diameter were determinated by myosin ATPase staining and NADH-tetrazolium reductase staining. Muscle fiber composition of the EDL and SOL was 94.6±1.8 and 14.8±4.3% FT fibers, respectively, and mean muscle fiber diameter was 62.7±6.2 pm and 79.2±7.8pm, respectively, that of the EDL being significantly smaller (p<0.01) than that of the SOL. It was suggested that individual differences in conduction velocity were caused by differences in muscle fiber composition rather than differences in muscle diameter.

A 67-year-old man receiving treatment for choledocholithiasis was found to have an abdominal aortic aneurysm on CT. The maximum diameter of the aneurysm was 60mm, and the isthmus of a horseshoe kidney was also observed. A total of four renal arteries, two each on the right and left sides, was detected by angiography and helical CT. Two of four arteries bifurcated from the aneurysm. Laparotomy confirmed the presence of a fifth renal artery, which extended from the left common iliac artery to the isthmus. It was not difficult to free the isthmus from the aneurysm. A Y-shaped prosthesis was placed between the normal portion of the aorta and the common iliac arteries without severing the isthmus. The left renal artery arose from the aneurysm and was reconstructed with 6mm knitted Dacron. The right renal artery, which was located below the isthmus, was ligated. The absence of postoperative renal dysfunction confirmed the patency of the reconstructed renal artery. Eleven such cases have been reported in Japan, including the present case. In 5 cases, renal artery reconstruction was performed, and the isthmus was preserved in 8 cases. However, the sites of renal artery bifurcation were correctly detected preoperatively in only 3 of these patients. It appears that accurate preoperative imaging is very important, along with renal artery reconstruction.

We report a 78-year-old man who had an impending ruptured atherosclerotic arch aneurysm combined with chronic dissecting ascending aortic aneurysm. The patient underwent a graft replacement of the ascending aorta and aortic arch using the elephant trunk method with the aid of profound hypothermia and continuous retrograde cerebral perfusion. Cerebral blood velocity was measured with transcranial Doppler (TCD) during operation. The TCD flow pattern after weaning of cardiopulmonary bypass indicated a state of brain edema. Therefore it is important in extensive retrograde cerebral perfusion to control the perfusion pressure and prevent destruction of the blood brain barrier aggressively. Pharmacological intervention could improve the safety of retrograde cerebral perfusion. Postoperative diagnostic images showed that the part of the distal anastomosis around the elephant trunk was not surrounded with thrombus. At this stage, it is not necessary to perform next extensive aortic replacement. It is important to consider the occurrence of complication, who using elephant trunk method, including paraplegia, thromboembolism, kinking of prothesis.

We report a case of dysphagia caused by compression of the esophagus by the nonaneurysmal tortuous descending aorta (dysphagia aortica). A 69-year-old woman was admitted suffering from dysphagia. Esophagoscopy showed esophageal stenosis caused by pulsatile and extramural compression. Esophagography and aortograms also showed that the nonaneurysmal tortuous descending aorta compressed the esophagus in an anteromedian direction. To avoid the esophageal ulcer and the aortoesophageal fistula, resection of the tortuous aorta and a Dacron graft replacement was performed. After operation compression of the esophagus was released and her complaint improved.

A 16-year-old girl with aortitis syndrome under treatment with a low dose of prednisolone was admitted because of severe headache and intermittent claudication. Angiography revealed diffuse stenosis of the thoracoabdominal aorta and the bilateral renal arteries. Extra-anatomical bypass grafting from the ascending to the abdominal aorta was first made with a 14mm woven Dacron graft through a midline sternolaparotomy. Bilateral renal arteries were difficult to dissect due to periarterial adhesion. Bypass grafting for the left renal artery could be performed with a 5mm external velour wrap-knit Dacron graft (Sauvage, Bionit); however, the right renal artery was so thin that bypass was made with a 4mm EPTFE graft which was demonstrated to be occluded by follow-up angiography 3 years after surgery. The postoperative course has been uneventful and she has been free from symptoms up to now. The good long-term function of the bypass graft from the ascending aorta holds promise for diffuse coarctation of the thoracoabdominal aorta due to aortitis syndrome.

There are many published studies on postoperative deep venous thrombosis (DVT) which can develop after hip joint arthroplasty, but very few reports are available on the incidence of thigh DVT following or thopedic treatment of transcervical fractures. In this study, therefore, we tried to find out a screening method just right for the early detection of clots that develop in the deep femoral veins after treatment of the feactures in the neck of femurs. Between March and September 1999, a total of 24 patients were operated on for fractures on the cervix of thighbone in our hospital. Of the total, 19 were recruited for this study. The five cases were excluded because some of them were on medication that could affect the coagulation/ fibrinogenolysis factors and some were under management of other departments. After surgery, a series of blood biochemical tests were performed, and changes in the partial pressure of arterial blood oxygen and D-dimer (??) level were examined with the passage of time. In the cases which were suspected to have thrombosis in the veins in the lower extremities by ultrasonography performed six to 18 days after surgery, definitive diagnosis was made by the aid of venography. DVT was found in three in the 19 cases. Routine blood biochemical tests and measurements of oxygen partial pressure in the artery were not so much helpful as were expected in the early detection of thrombosis, whereas measurements of D-dimer levels were considered useful because the levels were well over 20μg/ml one week after surgery in the positive-DVT cases.

The effect of lemon slices, as well as ascorbic and citric acid impregnated paper discs, on the growth of ten non-typhoidal Salmonella, six Citrobacter freundii and four Proteus mirabilis species on Desoxycholate Hydrogen Sulfide Lactose (DHL) agar were examined in comparison to controls without fruit slices or paper discs applied. After 24 h incubation, thick black rings were observed around fruit slices and impregnated discs growing on non-typhoidal Salmonella serovars and not around the other species. We named this the “MY Phenomenon”. We propose that the phenomenon can be used as a rapid, simple and inexpensive screening test that distinguishes non-typhoidal Salmonella species from other enterobacteriaceae in stool samples.