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Biomedical subjects

H Yoshimoto

Publications and source records attributed to H Yoshimoto.

At least 127 records · Page 7Linked to original sources
PubMed1986

Endoscopic retrograde cholangiography with a balloon catheter: analysis of 100 consecutive cases.

One hundred patients whose standard endoscopic retrograde cholangiographic studies gave poor visualization of the biliary tract were investigated using a balloon catheter introduced into the common bile duct by duodenoscopy to block contrast material leakage. Full diagnostic visualization was obtained in 90 patients, leading to accurate diagnosis in 88. In two other patients, the diagnosis was not confirmed. In ten patients the bile ducts were not filled because of balloon size (seven), vagovagal reflex (two), and fistula (one). There were no serious clinical complications. Laboratory studies following the procedure disclosed impaired liver function (three patients), hyperamylasemia (two), and leukocytosis (two) of 41 patients tested, and positive blood culture in three of 81 patients studied. When standard retrograde cholangiography fails to visualize the biliary tract, endoscopic retrograde balloon catheter cholangiography is a useful diagnostic procedure, associated with acceptable minor complications.

Adult↗
PubMed1985

Identification of an Rts1 DNA fragment conferring temperature-dependent instability to vector plasmids.

The multiphenotypic drug resistance factor Rts1 expresses a temperature-dependent instability characteristic. This plasmid was digested with the restriction enzyme BamHI. A DNA fragment with a molecular weight of 5.6 MDa (the H fragment) was inserted into plasmid pBR322 (pFK896) or into pSC105 (pYH156) at the BamHI site. These plasmids were unstable at 42 degrees C but stable at 32 degrees C. A restriction-enzyme map of the H fragment was constructed and the instability phenotype (Tdi) was localized to a DNA fragment with 0.5 MDa molecular weight. The temperature-dependent loss of the unstable plasmid pFK896 is abrupt and no gradual plasmid loss of this multicopy recombinant plasmid is observed. The possibility that the Tdi phenotype is due to overgrowth of R- cells was eliminated.

Ampicillin↗
PubMed1985

Cholangiography of intrahepatic bile ducts in hepatolithiasis by endoscopic placement of an indwelling balloon catheter.

To improve the diagnostic yield and safety of endoscopic retrograde balloon catheter cholangiography, two technical refinements were added: (1) intraductal retention of a balloon catheter allowing injection of a contrast medium in the supine position; and (2) slow, constant injection of the contrast medium with a heavy-duty infusion pump. Maximum filling of intrahepatic branches was attempted by both the original balloon method and the new method in seven hepatolithiasis patients. The new method was superior for visualization of the right intrahepatic ducts. Although there were no significant differences in the amount of filling of the left intrahepatic ducts, the new method provided an unobstructed view since the endoscope was out of the way. Harmful rapid increase of intraductal pressure and excessive injection of contrast medium were avoided by fluoroscopically controlled infusion. No serious complications were encountered.

Adult↗
PubMed1985

Manometric diagnosis of sphincter of Oddi spasm as a cause of postcholecystectomy pain and the treatment by endoscopic sphincterotomy.

Seventeen patients with postcholecystectomy pain and nine controls were studied by nonoperative biliary manometry with stimulation of sphincter of Oddi spasm by morphine. The controls remained asymptomatic despite an elevation of bile duct pressure after morphine. In 13 patients with postcholecystectomy pain, morphine induced pain paralleling a pressure rise. Three other patients had pain not paralleling a pressure change, and another showed a pressure rise without pain. None of the controls, four with the parallel pain-pressure change, and one with the discordant pain-pressure correlation were positive at the traditional morphine-Prostigmin test. Endoscopic sphincterotomy provided complete (8), moderate (3), or slight (1) relief of pain to 12 patients with the parallel pain-pressure relationship. Postsphincterotomy manometry showed disappearance of both the pressure elevation and pain induction, and the morphine-Prostigmin test turned negative. It is concluded that morphine-induced bile duct pressure elevation coinciding with pain is diagnostic of sphincter spasm as a cause of postcholecystectomy pain, the morphine-Prostigmin test, although helpful, is less specific and less sensitive in diagnosing sphincter spasm than the manometry, and endoscopic sphincterotomy relieves the pain due to this condition in most cases.

Adult↗
PubMed1985

Two approaches for electrohydraulic lithotripsy in the common bile duct.

Electrohydraulic lithotripsy is a method used to break up a stone by electric discharge in the presence of liquid medium. After the effect of crushing gallstones was tested in vitro, efficacy and safety of this method were investigated with 11 mongrel dogs. When the electrode was in touch with or close to the bile duct wall, the discharge caused perforation or potentially serious mucosal injury. However, a stone held in a basket catheter combined with the lithotripsy probe was fragmented safely in the bile duct in all the animals. Bile duct manometry showed a transient fall, which was followed by a slight increase, of the pressure on crushing the stone. After these studies in animals, three patients with stones in the common bile duct were treated successfully with the device via the percutaneous transhepatic route (one patient) or through the duodenoscopic route (two patients). Two approaches are now available for electrohydraulic lithotripsy in the common bile duct.

Adult↗
PubMed1984

Vitreous morphology after carbon dioxide laser irradiation.

The immediate vitreous changes produced by a continuous-wave carbon-dioxide laser beam in freshly enucleated bovine and pig eyes were studied by gross examination with a dissecting microscope, and histopathologically by light microscopy and transmission electron microscopy. The lesions produced by the laser beam on the vitreous in an air tissue interface technique were remarkable for their ring-shaped vitreous condensations. The diameter and density of these condensations increased with irradiance. With the same irradiation parameters the lesions at the anterior hyaloid membranes showed greater size and density than those in the central area of the vitreous. These vitreous condensations were demonstrated to consist of heat-denatured collagen fibrils. For light microscopic evaluation of the vitreous a modified method of tissue processing according to Szent Györgi has proven optimal in reducing vitreous shrinkage from dehydration. This method of fixation and tissue processing appeared to be useful in evaluating lesions of the vitreous and their relationship to their surroundings.

Animals↗