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Dive into the research topics where Michael O. Blackstone is active.

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Featured researches published by Michael O. Blackstone.


Digestive Diseases and Sciences | 1978

Cholangiographic abnormalities in ulcerative colitis associated pericholangitis which resemble sclerosing cholangitis

Michael O. Blackstone; Bernard A. Nemchausky

Cholangiographic abnormalities in asymptomatic patients with pericholangitis and longstanding ulcerative colitis, which resemble sclerosing cholangitis, have not been previously reported. Endoscopic retrograde cholangiography (ERC) performed in one such patient suggesting intrahepatic sclerosing cholongitis stimulated the study of seven additional patients with largely asymptomatic pericholangitis. In seven of these eight patients. ERC demonstrated abnormalities which resembled sclerosing cholangitis. These consisted of beading and structures mainly of the intrahepatic biliary tree (IHB). In two of the eight, the common bile duct was involved. In one, this was associated with histologic progression to cirrhosis and frank cholangitic episodes even though the initial clinical presentation and hepatic histology 2 1/2 years earlier suggested only pericholangitis. We therefore conclude that bile duct abnormalities resembling sclerosing cholangitis may be demonstrated cholangiographically in patients with ulcerative colitis who present with the typical picture of pericholangitis.


Cancer | 1985

Adenomatous polyposis coli and multiple endocrine neoplasia type 2b. A pathogenetic relationship

James T. Perkins; Michael O. Blackstone; Robert H. Riddell

A young man presenting with Cushings syndrome was found to have multiple endocrine neoplasia type 2b MEN 2b and adenomatous colonic polyposis with duodenal and gastric polyps. The entire syndrome of MEN 2b was present, including metastatic medullary carcinoma of the thyroid, a pheochromocytoma, and peripheral nerve abnormalities. The concurrence of these two inherited multiple neoplasia syndromes may reflect a common pathogenetic step in this patient.


Journal of Clinical Gastroenterology | 1990

Randomized clinical trial of two colonoscopy preparation methods for elderly patients.

Bret A. Lashner; Charles S. Winans; Michael O. Blackstone

Colonic lavage with enemas or with Golytely are standard preparation methods for colonoscopy. Previous studies have demonstrated that Golytely has a statistically significant advantage in both adequacy of preparation and patient tolerance. To determine if these effects are present in the elderly, we performed a randomized clinical trial on 124 consecutive patients scheduled for colonoscopy who were greater than or equal to 75 years of age. Sixty-three patients were randomized to receive Golytely; 17 were inpatients, 33 were outpatients, and colonoscopy was canceled in 13. Sixty-one patients were randomized to receive the enema preparation; 17 were inpatients, 30 were outpatients, and colonoscopy was canceled in 14. For adequacy of the preparation, no differences were statistically significant, but the enema preparation was superior in outpatients while Golytely was superior in inpatients. Patients tolerated the enema preparation better, a finding present in both outpatients and inpatients. Contrary to previous reports of a significant advantage with Golytely, patients greater than or equal to 75 years old did not enjoy this advantage, but seemed to tolerate enemas better than Golytely with little difference in adequacy of the preparation.


Journal of Clinical Gastroenterology | 1995

Rapidly progressive sclerosing cholangitis following surgical treatment of pancreatic pseudotumor

George Stathopoulos; A. Daniel Nourmand; Michael O. Blackstone; Dana K. Andersen; Alfred L. Baker

Two patients with sclerosing cholangitis presented with a distal stricture of the common bile duct in association with pancreatic pseudotumors. Jaundice resolved following surgery to correct biliary obstruction, but diffuse cholangiographic abnormalities and clinical evidence of sclerosing cholangitis became evident 2 and 4 months later. Rapid progression of symptomatic disease necessitated liver transplantation in one patient, but the other had a complete response to methotrexate therapy. The rapid disease progression in these two patients may have been triggered by surgery that resulted in a generalized fibroproliferative response of the biliary tree, already affected with localized sclerosing cholangitis contiguous to a pancreatic pseudotumor. We suggest that localized sclerosing cholangitis associated with pancreatic pseudotumors may be a unique variant that can progress rapidly but respond dramatically to antiinflammatory therapy.


Journal of Clinical Gastroenterology | 1997

Candida (Torulopsis glabrata) liver abscesses eight years after orthotopic liver transplantation.

Gary M. Annunziata; Michael O. Blackstone; John Hart; Piper Jb; Alfred L. Baker

The authors report the case of a 48-year-old man in whom candida (Torulopsis glabrata) liver abscesses developed 8 years after liver transplantation. After a week of fever, computed tomography and Doppler ultrasonography showed several fluid-filled loculations in the left lobe of the liver and hepatic arterial stenosis. Aspirates from the abscesses contained T. glabrata organisms. This complication probably developed because hepatic arterial stenosis resulted in bile infarcts (bilomas), which were contaminated via the biliary tract with candida from the biliary-enteric anastomosis. Catheter drainage and administration of amphotericin B for 10 weeks permitted successful retransplantation. T. glabrata liver abscesses, a life threatening complication that can occur long after liver transplantation, can be successfully managed by aggressive medical treatment followed by retransplantation.


Gastrointestinal Endoscopy | 1977

Intraductal aspiration for cytodiagnosis in pancreatic malignancy

Michael O. Blackstone; L. Cockerham; Joseph B. Kirsner; A.R. Moossa

Endoscopic pancreatic cytology was successfully performed in 11 of 14 consecutive patients with proven pancreatic malignancy. It was performed immediately following radiography after washing out the x-ray contrast material with normal saline. Cytology was positive in 8, equivocal in 2, and negative in 1. It was not performed in 3 patients in whom radiography was negative or unsuccessful. There was no associated morbidity. Endoscopic pancreatic cytology following radiography using a saline wash-out step is proposed as a rational and effective technique.


Journal of Clinical Gastroenterology | 1992

Prostate cancer metastatic to the stomach. Clinical aspects and endoscopic diagnosis.

William H. Holderman; J. Monique Jacques; Michael O. Blackstone; Thomas A. Brasitus

Although prostate carcinoma is the most common malignancy in males, it rarely involves the gastrointestinal (GI) tract. We report the first case of endoscopically diagnosed prostate carcinoma metastatic to the stomach in an 88-year-old man whose heralding symptoms were nausea, vomiting, and epigastric pain. The initial diagnosis was not suggested at presentation, but an upper endoscopy and biopsy suggested adenocarcinoma of uncertain primary site subsequently confirmed to be of prostatic origin by immunohistochemical staining. We review the clinical aspects and endoscopic diagnosis of this condition.


Digestive Diseases and Sciences | 1977

Reactive duodenal changes in chronic pancreatitis simulating the contiguous spread of pancreatic carcinoma.

Michael O. Blackstone; Hiroshi Mizuno

SummaryReactive duodenal changes including marked mucosal friability and nodularity were seen endoscopically in a patient with chronic pancreatitis and pseudocysts. These changes simulated the contiguous spread of cancer of the pancreas. In addition, their presence led to an unusual complication of endoscopic retrograde cholangiopancreatography (ERCP), a submucosal injection producing a portal venogram. The presence of marked mucosal friability may be a relative contraindication to performing ERCP in such patients.


The Lancet | 1997

Fibrin glue for bleeding peptic ulcers

Michael O. Blackstone

Spanish drug policy at the crossroads The Spanish pharmaceutical market is the seventh largest in the world and the fifth in Europe. Drug costs account for 25·3% of state health-care expenditure, reportedly the highest proportion in the industrialised world. Costcontainment measures introduced in recent years include a new system for fixing prices, a new reimbursement system, the separation of the authorisation and registration of products from reimbursement decisions (formerly all medicines were reimbursable), and a Fibrin glue for bleeding peptic ulcers See page 692 Bleeding peptic ulcers represent about 60% of the sources of upper gastrointestinal haemorrhage found at emergency endoscopy. Most will not be actively bleeding at the time of the examination. About half will have a clean base and uncomplicated presentation requiring no further treatment. For the 10% that are actively bleeding (ie, spurting or oozing), as well as those that look likely to bleed again (ie, have an adherent clot or visible vessel), an endoscopic injection of an agent such as adrenaline, alcohol, or polidocanol can be given, or the vessel heat treated with a thermal heater probe or by bipolar electrocoagulation. In about 80% treatment will be successful. The failure of initial endoscopic treatment in up to 20% has led to a search for better agents as well as better ways of using existing treatments. In today’s Lancet P Rutgeerts and colleagues report the results of a large (854 patients), randomised European trial of three different injection regimens—a single application of a sclerosing agent, polidocanol, single or multiple applications of fibrin glue. All patients were observed for at least 5 days after the initial treatment. There was no difference in the overall failure rate (patients requiring surgery) between polidocanol and a single fibrin-glue application (13% vs 12·4%), but in the group receiving fibrin-glue applications daily it was almost halved (7·7%). Most important was the influence of appearance of the ulcer at the time of randomisation, with the rate of studies of evolution. The finding of ICAM-1 polymorphism adds another level of diversity in the immune responses. If this polymorphism in ICAM-1 were to be found in the other adhesion receptors such as LFA3(CD58), this would amplify immune responses even further. The lessons about natural selection pressures to be learned by studying infectious diseases and these adhesion receptors cannot be underestimated or overemphasised strongly enough. M W Makgoba Department of Molecular Immunology, University of the Witwatersrand, Johannesburg 2000, South Africa


Digestive Diseases and Sciences | 1996

Chronic pancreatitis with alpha 1-antitrypsin deficiency: from uncontrolled trypsin activation?

Michael O. Blackstone

To The Editolv After catheterization of the duodenal papilla, especially following ERCP, an elewttion in the patients serum pancreatic enzyme levels is usually noted. Usually, this elevation is not associated with clinical manifestations and is called post-ERCP biological pancrcatitis ( 1 ). ERCP currently provides the best objective method for the diagnosis of pancreatic disease. Although the morbidity associated with ERCP in our department is very low, it is not completely absent (2). Several procedures have been suggested to reduce morbidity, including routine insertion of a pancreatic endoprothesis and administration of a somatostatin analog (3). None have proven useful. We therefore wished to compare two sexand age-matched groups of patients who had justifiable indications for ERCP. Group A consisted of 37 chronic alcoholic patients (>80 g alcohol/day for >5 years) without chronic calcifying pancreatitis (no ductal abnormalities), and group B consisted of 88 nonalcoholic patients (<30 g alcohol/day). Serum lipase (normal < 208 IU/liter) and amylase (normal < 110 1U/liter) were measured before ERCP and then 8 and 24 hr afterwards. No clinical symptoms or signs of pancreatitis were observed in either group. Serum amylase and lipase levels of >3 times normal were considered sufficient for the diagnosis of biological pancreatitis. Six patients from group A and 36 patients from group B were found to meet this criterion. This represents a statistically significant difference (P < 0.001). How can the difference between the two groups be interpreted? Chronic alcoholism causes pancreatic fibrosis, particularly around the ducts (4, 5). We suggest that this fibrosis may partially prevent the release of pancreatic enzymes into the blood following the rupture of acini due to rises in pressure in small pancreatic ducts (1). It is recognized that alcoholic patients with chronic calcifying pancreatitis tolerate therapeutic endoscopic procedures better than normal patients. Our study suggests that alcoholics may also have less hyperamylasemia and hyperlipasemia following ERCP even at an early stage before the onset of overt ductal abnormalities. We believe that this is a true protective effect rather than a misleadingly reassuring biological phenomenon. P. HASTIER, MD A.G. HARRIS, MD F.X. CAROLI-Bosc, MD R. DUMAS, MD J.P. DELMONT, MD Department of Hepatogastroenterology Nice University Hospital, Avenue Reine Victoria, 06000 Nice, France

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John Hart

University of Chicago

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Otto S. Lin

Virginia Mason Medical Center

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