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Biomedical subjects

D K Rex

Publications and source records attributed to D K Rex.

At least 91 records · Page 5Linked to original sources
PubMed1991

Screening colonoscopy in asymptomatic average-risk persons with negative fecal occult blood tests.

Colonoscopy was performed on 210 asymptomatic average-risk persons, aged 50-75 years, who had negative fecal occult blood test results. Colonoscopy was complete to the cecum in 209 subjects. Fifty-three subjects (25%) had adenomas and two had cancer. All of the adenomas greater than or equal to 1 cm in size and both cancers occurred in subjects aged greater than or equal to 60 years. Fifty-one percent of subjects with adenomas and one with cancer had no neoplasms distal to the sigmoid-descending colon junction. One subject had a major postpolypectomy hemorrhage that stopped spontaneously. Screening colonoscopy, therefore, has a high yield for detection of neoplasms in asymptomatic average-risk persons aged greater than or equal to 60 years with negative fecal occult blood test results. The yield is low in persons aged 50-54 years and intermediate in persons aged 55-59 years.

Adenoma↗
PubMed1991

Endoscopic detection of a tiny cecal ulcer containing carcinoma in-situ.

A 3-mm cecal ulcer without any adjacent polypoid structure was detected in a 66-year-old asymptomatic man undergoing screening colonoscopy. Biopsies demonstrated carcinoma in-situ. The literature on tiny colonic carcinomas and carcinoma in-situ in the absence of any polyp is reviewed in this article.

Aged↗
PubMed1991

Barium enema use in Indiana.

All 118 hospital-based radiology departments in Indiana responded to a survey of barium enema (BE) use. The percentage of community hospitals in Indiana using barium enema, both single contrast (SCBE) and double contrast (DCBE) for various indications, was similar to that reported for major medical centers around the world. The use of SCBE and DCBE did not differ between small and large hospitals or between hospitals in small versus large communities. There was, however, wide variation among community hospitals in their overall use of either contrast technique. Barium enema usually was performed without antecedent sigmoidoscopy. However, 60% of Indiana hospitals perform BE on the same day as flexible sigmoidoscopy. The results indicate that the use of BE in community hospitals in Indiana is similar to that reported for major medical centers. Like major medical centers, there is no consensus regarding many issues in the performance of BE.

Barium Sulfate↗
PubMed1991

Radiographic evaluation of suspected small bowel obstruction.

Plain abdominal radiographs and enteroclysis studies were reviewed blindly in 117 consecutive patients undergoing enteroclysis for suspected small bowel obstruction. Plain radiographs were unreliably predictive of the presence of obstruction as determined by enteroclysis and surgery. Among patients with normal or abnormal nonspecific plain radiographs, varying degrees of small bowel obstruction were demonstrated by enteroclysis in 22%. Conversely, of patients with obstruction on plain radiographs, 42% had either normal enteroclysis studies or only minor adhesions. Enteroclysis correctly predicted the presence of obstruction in 100%, the absence of obstruction in 88%, the level (proximal vs distal) of obstruction in 89%, and the etiology of obstruction in 86% of operated patients. Enteroclysis is advocated as the definitive study in patients with clinical uncertainty about the diagnosis of small bowel obstruction.

Diagnosis, Differential↗
PubMed1991

Failure of physicians to recognize acetaminophen hepatotoxicity in chronic alcoholics.

We encountered six alcoholic patients with severe acetaminophen hepatotoxicity during a 2-year period. All patients had marked elevations of aminotransferases and sometimes remarkably high prothrombin times at, or shortly after, presentation. In five of six cases the diagnosis was missed by the physicians initially caring for the patient. The apparent reasons for the missed diagnosis were insufficient history regarding the use of acetaminophen, an inappropriate reliance on blood acetaminophen levels, and lack of knowledge regarding typical aminotransferase elevations in alcoholic hepatitis vs acetaminophen toxicity. The initial clinical presentation of acetaminophen hepatotoxicity in chronic alcoholics is easily recognized clinically and is distinct from acetaminophen hepatotoxicity in suicide ingestions and from alcoholic hepatitis. Internists and other physicians should be aware of this entity and rely on the clinical picture and the history of acetaminophen use to confirm the diagnosis.

Acetaminophen↗
PubMed1990

Barium enema utilization within a defined geographic region: a survey.

All 118 hospital-based radiology departments in Indiana (USA) responded to a survey of barium enema (BE) utilization. The percentage of community hospitals in Indiana using barium enema, both single contrast (SCBE) and double contrast (DCBE), for various indications was similar to that reported for major medical centers around the world (RF Thoeni and AR Margulis, Radiology, 167: 7-12, 1988). The use of SCBE and DCBE did not differ between small and large hospitals, or between hospitals in small vs large communities. There was, however, wide variation among community hospitals in their overall use of either contrast technique. Barium enema was usually performed without antecedent sigmoidoscopy. However, 60% of Indiana hospitals perform BE on the same day as flexible sigmoidoscopy. The results indicate that the use of BE in community hospitals in Indiana is similar to that reported for major medical centers. Also like major medical centers, there is no consensus regarding many issues in the performance of BE.

Barium↗
PubMed1990

Association of anterior ectopic anus and partial absence of levator musculature in a woman with impaired defecation. Report of a case.

A 25-year-old nulliparous woman with adult onset constipation and slight anterior displacement of the anus underwent pelvic magnetic resonance imaging and was diagnosed with congenital hemiabsence of the levator ani sling. Impaired defecation was confirmed by anorectal function studies and defecography demonstrated an anterior rectocele, perineal descent at the upper limit of normal, and partial obstruction of defecation, which appeared related to the levator sling abnormality. To our knowledge, this combination of findings has not been previously described as a cause of adult onset constipation.

Adult↗
PubMed1990

Flexible sigmoidoscopy plus air contrast barium enema versus colonoscopy for suspected lower gastrointestinal bleeding.

A randomized, controlled trial was performed to compare the diagnostic yields and cost-effectiveness of two strategies for the evaluation of nonemergent lower gastrointestinal bleeding. Three hundred eighty patients aged greater than or equal to 40 yr were randomized to undergo initial flexible sigmoidoscopy plus air contrast barium enema or colonoscopy; 332 completed the initial studies. Initial colonoscopy detected more cases of polyps less than 9 mm in size, adenomas, and arteriovenous malformations but fewer cases of diverticulosis. No significant difference was found between strategies in the number of patients detected with cancers or polyps greater than or equal to 9 mm in size. In both strategies, cancers were more common in subjects aged greater than or equal to 55 yr (8% overall) than in those aged less than 55 yr (1%). Among patients aged less than 55 yr with suspected lower gastrointestinal bleeding, initial flexible sigmoidoscopy plus air contrast barium enema is a more cost-effective strategy for the detection of colonic neoplasms than initial colonoscopy. However, initial colonoscopy is more cost effective for those aged greater than or equal to 55 yr.

Barium Sulfate↗
PubMed1989

Enteroclysis in the evaluation of suspected small intestinal bleeding.

One hundred twenty-five consecutive enteroclysis studies performed for the indication of gastrointestinal bleeding were reviewed. The overall yield of positive studies was low (10%) but important lesions were found. Patients with unequivocally normal evaluations of the upper gastrointestinal tract and colon had the highest yield of positive enteroclysis studies (20%). Neither the specific type of bleeding, the presence or absence of abdominal symptoms or physical examination findings, nor the results of laboratory tests were associated with a positive or negative enteroclysis study.

Angiography↗
PubMed1988

Further characterization of the pigment in pseudomelanosis duodeni in three patients.

Pseudomelanosis duodeni is a rare condition in which dark pigment accumulates in macrophages located in the lamina propria of the duodenal mucosa. Three cases are reported here and the literature is reviewed. No clinical association can be found that points clearly to the underlying etiology. Electron probe x-ray microanalysis was used to study the pigment in macrophage granules in 2 of our patients and demonstrated high iron and sulfur content. Iron accumulation in ferritinlike particles was detected in absorptive cell lysosomes. A possible mechanism for the accumulation of absorbed iron by macrophages is considered.

Aged↗
PubMed1988

Comparison of radially sensitive and circumferentially sensitive microtransducer esophageal manometry probes in normal subjects.

Circumferentially sensitive microtransducer probes are commercially available for use in esophageal manometry, and may offer an advantage over radially sensitive microtransducer probes in sphincters with radial asymmetry. In order to compare performance of the two probes, we performed esophageal manometry in 30 healthy adult volunteers with both probes. In only three of 52 manometric parameters measured were differences between mean values for the two probes statistically significant. Intrasubject variability was significantly (p = less than 0.005) less with the circumferentially sensitive probe (coefficient of variation 37% vs. 53%).

Adult↗
PubMed1987

Purification and characterization of the Danish (Skive) variant of mouse liver alcohol dehydrogenase.

The partially inbred Danish (Skive) strain of mice exhibits a form of liver alcohol dehydrogenase (ADH) which differs in electrophoretic mobility from that of all other inbred mouse strains thus far examined, e.g., C57BL/10, DBA/2J, and BALB/c. In order to compare the catalytic and molecular properties of the "variant" and "normal" enzyme forms, they were purified to homogeneity by ion-exchange and affinity chromatography. Tryptic peptides of reduced and carboxymethylated subunits of the normal and variant ADH forms were mapped by thin-layer two-dimensional electrophoresis and chromatography and by reversed-phase high-performance liquid chromatography. A unique nonapeptide in the Danish mouse liver ADH which did not appear in enzymes from C57BL/10, DBA/2J, or BALB/c mice was identified by both methods. Amino acid sequencing of this peptide revealed that the Arg residue at position 124, as predicted from the cDNA sequence of ADH in DBA/2J mice, has been replaced by Leu in the Danish variant. The Leu for Arg substitution in the variant form appears to account for its decreased cathodic mobility with electrophoresis in starch gels at pH 7.2. The Km and Vmax of ADH from the Danish strain for three primary alcohols and three aldehydes were similar in value to those of ADH from the C57BL/10, DBA/2J, and BALB/c strains. Based on the X-ray structure of horse liver ADH, position 124 is on the solvent-exposed surface of the catalytic domain. The finding that the kinetic constants are similar for the normal and variant forms is consistent with the observation that this residue is not in the active site and that there is no known role for it in the ADH catalytic mechanism.

Alcohol Dehydrogenase↗
PubMed1986

Sensitivity of double-contrast barium study for left-colon polyps.

A blinded, prospective study was conducted to determine the sensitivity of double-contrast barium enema examination (DCBE) in detecting left-colon polyps. Metal clips were endoscopically placed on normal mucosa either adjacent to polyps (in 65 study subjects with 92 polyps) or not adjacent to polyps (in 50 control subjects). DCBE had a high sensitivity for detection of polyps greater than or equal to 1 cm and 6-9 mm in size (100% and 83% detection, respectively) but was insensitive in detecting polyps in the 4 to 5-mm and 2 to 3-mm size ranges (56% and 22% detection, respectively). The factors contributing most commonly to false-negative interpretations were the presence of air bubbles, overlap of bowel loops, and luminal fecal debris. No error in radiographic technique was evident to account for false-negative interpretations in 14 (41%) of 34 polyps that were not detected by DCBE.

Barium Sulfate↗
PubMed1985

Gastric concretion forming around a suture nidus and mimicking a gastric polyp on radiographs.

A small gastric mass was detected by upper GI X-ray series and found at endoscopy to be a concretion hanging from a suture at a previous gastrostomy site. The suture was clipped and the concretion was removed endoscopically. Sutures protruding into the gastric lumen may serve as a nidus for the formation of concretions and because of their fixed position, these masses may mimic neoplasms on upper GI X-rays.

Diagnosis, Differential↗