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Biomedical subjects

W T Knoefel

Publications and source records attributed to W T Knoefel.

11 recordsLinked to original sources
PubMed1992

A better model of acute pancreatitis for evaluating therapy.

Existing models of acute pancreatitis have limitations to studying novel therapy. Whereas some produce mild self-limited pancreatitis, others result in sudden necrotizing injury. The authors developed an improved model providing homogeneous moderately severe injury by superimposing secretory hyperstimulation on minimal intraductal bile acid exposure. Sprague-Dawley rats (n = 231) received low-pressure intraductal glycodeoxycholic acid (GDOC) at very low (5 or 10 mmol/L) concentrations followed by intravenous cerulein. Cerulein or GDOC alone caused only very mild inflammation. However, GDOC combined with cerulein was uniformly associated with more edema (p less than 0.0005), acinar necrosis (p less than 0.01), inflammation (p less than 0.006), and hemorrhage (p less than 0.01). Pancreatic injury was further increased and death was potentiated by increasing volume and duration of intraductal low-dose GDOC infusion. There was significant morphologic progression between 6 and 24 hours. The authors conclude that (1) combining minimal intraductal bile acid exposure with intravenous hyperstimulation produces homogeneous pancreatitis of intermediate severity that can be modulated at will; (2) the injury is progressive over at least 24 hours with finite mortality rate; (3) the model provides superior opportunity to study innovative therapy.

Acute Disease↗
PubMed1992

Is aggressive surgical palliation of proximal bile duct cancer with involvement of both main hepatic ducts worthwhile?

The only curative treatment for proximal bile duct cancer with involvement of both main hepatic ducts is liver transplantation. Most patients do not fulfill the requirements for liver transplantation. Our treatment strategy in appropriate cases is palliative tumor resection and reconstruction of the biliary passage by sutureless bilioenteric anastomosis. We have treated 12 patients, 5 in combination with intraluminal and percutaneous radiotherapy. Our results indicate that this strategy leads to effective palliation in some cases provided that only microscopic residual tumor is left in-situ. Our survival times compare favourably with survival after liver transplantation.

Aged↗
PubMed1992

Accurate diagnosis of acute appendicitis: a retrospective and prospective analysis of 686 patients.

OBJECTIVE: To formulate a score system that would make the preoperative diagnosis of acute appendicitis more accurate. DESIGN: Retrospective then prospective study. SETTING: City University Hospital. SUBJECTS: 536 patients who had their appendixes removed between 1981 and 1986 (retrospective study), and 150 consecutive patients admitted with a presumptive diagnosis of appendicitis between 1987 and 1988 (prospective study). MAIN OUTCOME MEASURES: Correlation between the histological diagnosis of appendicitis and variables representing history, clinical examination, and laboratory investigations. RESULTS: The rate of histologically proven negative appendicectomies in the retrospective series was 40% and in the prospective series 33%. The variables that were thought to be predictive were: male sex, white cell count of greater than 11 x 10(9)/l, history of less than 24 hours with no previous complaints, rebound tenderness, shift of pain from the epigastrium, and localised guarding, but all criteria had low specificities and sensitivities when applied prospectively, and combining the scores did not improve them. CONCLUSION: The accurate diagnosis of appendicitis depends largely on the experience of the surgeon and is not improved by the application of a score system that includes the above variables.

Acute Disease↗
PubMed1991

Optimal technique for detection of gallstones at injection cholecystography: in vitro analysis.

Injection cholecystography is often employed during invasive gallbladder procedures to determine the number of gallstones that are present. The authors undertook this study to define the optimal radiographic technique for performance of injection cholecystography. Condoms filled with 100 mL of contrast medium at four different iodine concentrations (30%, 15%, 7.5%, and 3.8% [wt/vol]) and containing up to five 4-mm-thick gallstones or a single 10-mm-thick gallstone were radiographed in a 20-cm-deep water bath by using four kilovolt peak settings (70, 80, 90, and 100 kVp). Images were read by three radiologists who were blinded to the radiographic technique. significantly (P less than .05) improved Decreasing iodine concentration significantly (P less than .05) improved detection of 4-mm-thick gallstones at a constant kilovolt peak setting. However, increasing the kilovolt peak setting while using the same concentration of contrast medium had no statistically significant influence on gallstone detectability, although radiologists did indicate a preference for the high-kilovolt peak technique. Results of the authors' experiments showed that for detection of small gallstones at injection cholecystography, use of a low-concentration contrast medium and a high kilovolt peak setting is the recommended radiographic technique.

Cholecystography↗
PubMed1991

[The treatment of humeral shaft fractures. Results of a prospective AO multicenter study].

This prospective multicenter study conducted by the German section of the AO International analyzes 302 fractures of the humeral shaft, 170 (56%) of which were operated upon and 132 (44%), treated conservatively. Among those operated upon, 3.5% developed infections and 10% showed paresis of the radial nerve. In contrast, the only complication in the group treated conservatively was pseudarthrosis, in 1 case. However, further analysis revealed that complications were distributed unequally among the centers and the most complications were reported from only a few hospitals. We were able to contact 173 (57%) patients for follow-up. Results of operative and conservative treatment were compared for similar fractures. Both techniques resulted in predominantly good to excellent results. The somewhat inferior results in the group operated upon were explained by the higher percentage of associated local injuries and concomitant injuries to other organs. The results of this study were compared with those of other recent studies, and recommendations were established for the operative and conservative treatment of fractures of the humeral shaft.

Adolescent↗
PubMed1990

Duodenum-preserving resection of the head of the pancreas in treatment of chronic pancreatitis.

Twenty-four patients underwent duodenum-preserving resection of the head of the pancreas for chronic pancreatitis of the head. All patients were reassessed in our follow-up clinic. Comparison with partial duodenopancreatectomy showed that both procedures can alleviate the majority of symptoms. However, duodenum-preserving resection of the head of the pancreas has lower early and late postoperative complication rates. It facilitates occupational rehabilitation, does not alter the patients glucose metabolism, and leaves fewer patients symptomatic in long-term follow-up. A higher rate of recurrence of pancreatitis of the tail is not found. Duodenum-preserving resection of the head of the pancreas is thus considered to be an alternative to partial duodenopancreatectomy in treatment of severe chronic pancreatitis of the head.

Adult↗