Search PubMed⌕ Search

Biomedical subjects

F C Chang

Publications and source records attributed to F C Chang.

At least 127 records · Page 7Linked to original sources
PubMed1984

Intraplaque hemorrhage: its significance in cerebrovascular disease.

Recently, carotid plaque factors, specifically intraplaque hemorrhage, have been studied with respect to the production of cerebrovascular symptoms. Ninety-five carotid endarterectomies were performed and the plaques that were removed were examined for intraplaque hemorrhage. Patients were separated into three groups: those with specific neurologic symptoms, those with nonlateralizing symptoms, and those who were asymptomatic. In the group of patients who presented with specific neurologic symptoms, correlation was made between the age of the intraplaque hemorrhage and the timing of symptoms. The vast majority of patients with specific neurologic symptoms exhibited carotid plaque hemorrhage, but patients with nonlateralizing symptoms and those who were asymptomatic also demonstrated an unexpectedly high percentage of intraplaque hemorrhage. Moreover, our results show a poor relationship between the timing of symptoms and the age of the intraplaque hemorrhage. These data do not refute the concept that intraplaque hemorrhage may play a role in the production of cerebrovascular symptoms, but they do refute the notion that the mere presence of hemorrhage causes specific neurologic symptoms and they also refute the previous report that demonstrates a good correlation between the timing of symptoms and the age of the intraplaque hemorrhage.

Aged↗
PubMed1984

Conditioned taste aversions modify neural responses in the rat nucleus tractus solitarius.

Explorations of the neural substrates of conditioned taste aversions (CTAs) have focused principally on diencephalic and telencephalic structures. The nucleus tractus solitarius (NTS) is the initial gustatory relay in the rat's hindbrain. It is worthy of investigation for its part in mediating CTAs in that it is sensitive to several physiological conditions which affect feeding while also being a site of anatomical convergence for vagal afferents from the viscera and centrifugal projections from areas (hypothalamus, amygdala) implicated in emotions and hedonics. We compared single neuron responses from NTS to several taste stimuli in three groups of rats: (1) those receiving exposure to 0.0025 M sodium saccharin without physiological consequences; (2) those made ill through intraperitoneal injections of LiCl but having no obvious gustatory referent for their malaise (sensitization-pseudoconditioning controls); (3) those in which exposure to 0.0025 M sodium saccharin (the CS) was paired with LiCl-induced poisoning (the US), creating a pronounced aversion to the saccharin. According to response profiles, NTS neurons in all three groups could be divided into subsets of about 30%, which showed a sweet-sensitive profile, and 70%, which were primarily sensitive to nonsweet qualities. The major effect of the conditioning procedure was to increase responsiveness to the saccharin CS only among the sweet-sensitive subset. Moreover, the peak of activity which largely accounted for the increase occurred with a latency of 900 msec, perhaps implicating a secondary input to NTS from diencephalic or telencephalic sites. The significance of the results is that: (1) CTAs affect sensory activity at a lower order level than had heretofore been demonstrated; (2) NTS shows sensitivity to yet another physiological condition, reinforcing the involvement of the hindbrain in hedonics and sophisticated taste-related processes; (3) there is a subset of taste neurons, rather distinct according to its sensitivity profile, which is also functionally unique in its response to conditioning by a sweet CS.

Animals↗
PubMed1983

Separation of mono-, di-, and trihydroxy stereoisomers of bile acids by capillary gas-liquid chromatography.

Capillary gas-liquid chromatographic separation was studied for the complete set of the 26 theoretically possible isomers of mono-, di-, and trihydroxylated 5 beta-cholanic acids, which differ from one another in the number, position, and configuration of hydroxyl groups at C-3, C-7, and/or C-12 in the nucleus, as well as for some of their related acids. The bile acid samples were chromatographed as their methyl ester-trimethylsilyl (TMSi) ether derivatives and analyzed on three capillary columns coated with nonpolar OV-1, slightly polar OV-17, and polar SP-2340 as liquid phases. The retention times on capillary gas-liquid chromatography (GLC) responded dramatically to the minor structural differences, and almost complete separation of the positional and stereochemical isomers was achieved by the combined use of SP-2340 and OV-17 (or OV-1) capillary columns.

Bile Acids and Salts↗
PubMed1982

The stereospecificity of 3 alpha- and 12 alpha-bile salt hydroxysteroid dehydrogenase systems from four microbial sources.

5 beta-Cholanoates, having a hydroxyl group in the 3 alpha and 3 beta and/or 12 alpha and 12 beta configurations, were tested as substrates for two preparation of 3 alpha-hydroxysteroid dehydrogenase (HSDH) and two preparations of 12 alpha-HSDH. When the 3-OH group was in the alpha configuration, both 3 alpha-HSDH preparations reacted, but when it was in the beta configuration, neither 3 alpha-HSDH preparations reacted. This also held true for the 12 alpha-HSDH preparations.

3-Hydroxysteroid Dehydrogenases↗
PubMed1981

Debridement pancreatectomy for pancreatic abscess.

Experience with seven cases of pancreatic abscess is reviewed. All patients were treated with radical pancreatic debridement, large sump drainage with postoperative irrigation, gastrointestinal defunctionalization, antibiotic therapy and nutritional support. One patient died, for a mortality rate of 14 percent. We feel that this regimen will help maximize survival in patients with pancreatic abscess.

Abscess↗
PubMed1981

Drainage in elective cholecystectomy.

This randomized, prospective study evaluates drainage of the subhepatic space in patients undergoing simple, uncomplicated cholecystectomy. One hundred twenty-two patients were divided into open (Penrose) drainage, closed sump drainage and no drainage groups. Open drainage resulted in increased morbidity and a longer postoperative hospital stay. The best results were in patients without drains. Subhepatic drainage is unnecessary in simple, uncomplicated cholecystectomy.

Acute Disease↗
PubMed1980

The incidence and significance of elevations of serum and urinary amylase levels following transcystic duct cholangiography.

Transcystic duct cholangiography does not increase the incidence of amylase elevations or clinical pancreatitis postoperatively. Significant rises in serum and two hour urinary amylase following routine cholecystectomy are quite common, regardless of whether or not transcystic duct cholangiography is performed. Many of these elevated amylase levels may arise from sources other than the pancreas.

Adult↗
PubMed1978

Intravenous cholangiography in the diagnosis of acute cholecystitis.

We reviewed our experience with intravenous cholangiography in the evaluation of 70 patients with suspected acute cholecystitis. Twenty-one of these patients had visualization of the biliary ducts without opacification of the gallbladder, a roentgenographic finding that was considered diagnostic of acute cholecystitis. Twenty of the 21 patients were noted to have acute cholecystitis during exploratory laparotomy. The remaining patient had a normal gallbladder, but was found to have a liver abscess. Opacification of the gallbladder with evidence of gallstones was found in eight patients; all had acute cholecystitis. Visualization of the gallbladder without gallstones was found in 22 patients, revealing no acute cholecystitis in this group. Many of these patients were admitted to the hospital with a primary diagnosis of acute cholecystitis and were spared an unnecessary surgical exploration. Nineteen patients had nonvisualization of the gallbladder and biliary ducts. This roentgenographic finding may be caused by acute intra-abdominal conditions other than cholecystitis and caution is warranted in its interpretation. This test has been found to be a reliable adjunct in the work-up of patients with suspected acute cholecystitis.

Acute Disease↗
PubMed1978

Abdominal aortic aneurysms. A comparative analysis of surgical treatment of symptomatic and asymptomatic patients.

This retrospective study of 120 patients identified three separate variables that influence operative mortality in patients with abdominal aortic aneurysms. These are age, presence or absence of symptoms, and presence of three preoperative risk factors or more. Based on this study and the fact that any aneurysm may rupture without warning, we conclude that observation of good risk asymptomatic patients until symptoms occur is unjustified. Asymptomatic patients less than seventy years old can undergo abdominal aortic aneurysmectomy with minimal mortality. Carefully selected asymptomatic patients more than seventy years old can also under surgical intervention with acceptable results.

Age Factors↗
PubMed1977

Inguinal herniorrhaphy under local anesthesia. A prospective study of 100 consecutive patients with emphasis of perioperative morbidity and patient acceptance.

For various reasons, repair of inguinal hernias under local anesthesia is not well accepted. The purpose of this study is to evaluate the effectiveness of local anesthesia in inguinal hernia repairs. One hundred consecutive inguinal herniorrhaphies are reported. The selection of patients, surgical technique, and incidence of intraoperative and postoperative complications are reported. Patient acceptance and their immediate postoperative course are also described. The study demonstrates that inguinal hernias can be easily repaired under local anesthesia, complications are minimal, and patient acceptance, excellent. We strongly recommend thath this form of anesthesia be used in the "routine" repair of inguinal hernias in cooperative patients.

Adult↗
PubMed1977

Massive upper gastrointestinal hemorrhage in the elderly.

Sixty-six elderly patients with massive upper gastrointestinal bleeding were retrospectively analyzed. This study supports the concept of vigorous resuscitation, early diagnosis with fiberoptic endoscopy, and prompt surgical intervention in patients with continued bleeding. When this approach was utilized in a community hospital, operative mortality was reduced to 5 per cent.

Aged↗