Search PubMed⌕ Search

Biomedical subjects

C L Morgan

Publications and source records attributed to C L Morgan.

At least 55 records · Page 3Linked to original sources
PubMed1992

Predictive markers for hepatitis C antibody ELISA specificity in Australian blood donors.

The hepatitis C antibody reactivity rate in 91,748 blood donors tested using the ORTHO HCV C-100 ELISA system was 0.51%. Specificity of ELISA positive reactions was measured using a recombinant immunoblot assay (RIBA). The aim of this study was to identify markers in ELISA positive donors which were predictive of a RIBA positive result. Samples from 430 ELISA positive donors were tested by the first generation RIBA, RIBA-1, which incorporates two HCV peptides C-100 and 5-1-1. Fifty-five per cent (236) were positive and 19% (83) indeterminate. Multivariate analysis of gender, age, HCV ELISA OD ratio, alanine aminotransferase (ALT) status and hepatitis B core antibody (anti-HBc) status identified age, magnitude of HCV ELISA OD ratio and anti-HBc status as the only independent predictors of a positive RIBA-1 result. The relative odds of being RIBA-1 positive were 4.6-fold (95% CI 1.3-16.4) higher among donors aged 25-34 years compared with donors less than 25 or greater than 44; 6.1-fold (2.1-17.9) higher if the donor was anti-HBc positive and 273.4-fold (30.9-2417) higher if the HCV ELISA OD ratio was greater than 5.98 compared to those with a ratio less than 1.77. Seventy-eight of the 83 RIBA-1 indeterminates were tested on the second generation RIBA, RIBA-2, which includes two additional HCV peptide, C22 and C33c. Thirty-one per cent (24) were positive and 41% (32) were negative.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Effects of subliminal backward-recorded messages on attitudes.

This study was designed to measure the effects of subliminal backward messages on attitudes. It was hypothesized that subliminal backward-recorded messages would influence the attitudes of listeners. Three subliminal backward-recorded messages from a popular song were used. 82 undergraduates were randomly assigned to one of four conditions: a three-message group heard a tape containing the backward messages recorded three times in succession, a six-message group heard a tape with the same backward messages recorded six times in succession, two control groups heard nonbackward recorded music. No statistically significant differences were found between the groups on a posttape attitude questionnaire. The results are discussed in terms of unconscious processing and the tricomponent theory of attitudes and attitude change.

Attitude↗
PubMed1991

The effect of intravenous immunoglobulin on placental transfer of a platelet-specific antibody: anti-P1A1.

The isolated perfused lobule of human placenta was used as an in-vitro model to study the effect of intravenous immunoglobulin (IVGG) on the placental transfer of a human platelet-specific antibody (anti-P1A1). Normal human IgG was shown to transfer from the maternal to the fetal circulation of the placental model after a lag period of 2-3 h. IVGG also transferred across the placenta but only after a longer lag period (3-4 h) than normal human IgG at the same concentration, which suggests that IVGG may contain a factor that inhibits the transfer of its own component IgG. The sensitive Western immunoblotting technique was used to demonstrate progressive transfer of anti-P1A1 antibody to the fetal circulation after a 2-3 h lag period. When IVGG and anti-P1A1 antibody were added simultaneously to the maternal circulation, the transfer of platelet-specific antibody was strongly inhibited by IVGG. The inhibitory effect of IVGG on anti-P1A1 antibody transfer was consistent for three different batches of the same IVGG product (Sandoglobulin). These studies provide the first scientific data to support the use of IVGG to inhibit antiplatelet antibody transfer as part of the antenatal management of neonatal alloimmune thrombocytopenia.

Antibodies↗
PubMed1987

An outbreak of watermelon-borne pesticide toxicity.

The largest reported United States outbreak of illness caused by a foodborne pesticide was due to aldicarb-contaminated watermelons. In Oregon, where the first episodes of toxicity were reported, 264 reports were received, and 61 definite cases were identified. Residues of aldicarb, a cholinesterase inhibitor, were found in 10 of 16 tested melons which had been eaten by persons meeting the case definition. The outbreak demonstrates the need for enhanced physician vigilance with respect to anticholinesterase intoxication. It also demonstrates the value of an established system for reporting of unusual illness to public health officials.

Aldicarb↗
PubMed1981

Ultrasonic angiographic and pathologic correlation of noncystic-appearing renal masses.

The ultrasonic echo pattern of renal masses is retrospectively correlated with the angiographic vascular pattern in 36 cases where a noncystic-appearing mass was identified by either study. Pathologic or cytologic correlation was available in 31 of these masses. In carcinomas the echogenicity was usually found to correlate well with the degree of neovascularity.

Adenocarcinoma↗
PubMed1981

Computed tomography in the evaluation, staging, and therapy of carcinoma of the bladder and prostate.

Computed tomography was performed in 24 patients with bladder carcinoma, 29 patients with prostate carcinoma, and one patient with simultaneous bladder and prostate carcinoma. In nine patients (16%), the stage of the carcinoma would have been underestimated based on CT alone. Six of these nine patients had only microscopic or laboratory evidence (elevated serum acid phosphatase level) of more widespread disease than what was demonstrated by CT. The overall accuracy of pelvic lymph node evaluation by CT was 79% in 34 patients. The 21% inaccuracy arises from five false-negative cass in which there was microscopic involvement within normal-sized nodes (4 patients) or only minimally enlarged (2.0 cm or less) nodes (1 patient), and two false-positive cases related to benign changes in nodes. CT was unable to differentiate Stage A, B1, and B2 bladder tumors. CT was used in planning portals for 16 patients who underwent external beam radiation therapy. CT was also used to measure the volume of the prostate prior to placement of 125I seeds for therapy, and to assess the positioning of the seeds.

Brachytherapy↗
PubMed1980

Abdominal and obstetric applications of a dynamically focused phased array real time ultrasound system.

Abdominal and obstetric applications of a dynamically focused phased array real time ultrasonic system are described. This work was performed utilising both the Thaumascan (two-dimensional, high resolution, actual time, ultrasound, multi-element array scanner) and the first commercial unit based on this system, the Grumman RT-400. Examples of normal and pathological anatomy are presented from over 300 examinations performed to date, including a series of 28 abdominal aortic aneurysms studied with the RT-400. Following electronic alterations in the Thaumascan with resultant improvement in the grey scale, prospective analyses in 86 obstetric and 23 abdominal examinations were undertaken. These studies indicate that fetal, intra-uterine, and abdominal structures can be rapidly and consistently imaged. The value of real time ultrasonic scanning in obstetric and abdominal examinations is illustrated. The principles of dynamically focused phased arrays are described, and the merits and limitations of these systems are discussed.

Abdomen↗
PubMed1980

Ultrasonic diagnosis of obstructed renal duplication and ureterocele.

The diagnoses of complete obstruction in a duplicated renal collecting system and ureterocele can be made with a high degree of confidence by ultrasound. Two children presenting with abdominal masses were examined by gray scale ultrasonography which demonstrated large cystic masses dorsal to and displacing the lower pole of the kidney ventrally and laterally. In one patient the dilated ureter terminated in a ureterocele. Ultrasonography is the appropriate imaging modality for this disease process, though it generally becomes the complementary study to excretory urography in the diagnosis of an obstructed duplicated system. The dilated pelvis and ureter can be imaged to ultrasonography even when their presence is only implied on an excretory urogram. Finally, the cystic nature of a ureterocele, as well as its relationship to the ureter and bladder, makes ultrasonography an ideal technic for evaluating this anomaly.

Child↗
PubMed1980

Ultrasound patterns of disorders affecting the gastrointestinal tract.

A mass associated with the gastrointestinal tract was detected by sonography in 33 patients. Etiologies included primary or metastatic tumor; intussusception; inflammation secondary to bowel infarction, pancreatitis, or irradiation; and a dilated, fluid-filled gut related to retained gastric contents, obstruction, ileus, or an ileal bypass. Mesenteric or omental changes were identified with inflammation and frequently with metastatic disease. The diagnosis was confirmed by repeat sonography, abdominal radiography, barium examination of the small bowel, computed tomography, surgery, or autopsy. Ultrasound patterns are characteristic in tumor, intussusception, and inflammation; specific features allowing differentiation between tumor and inflammation are described. Colonic haustra, valvulae conniventes, or bowel contours and peristalsis on real-time sonography are helpful in identifying fluid-filled bowel loops.

Adult↗
PubMed1979

Applications of real-time ultrasound in obstetrics: the linear and dynamically focused phased arrays.

Real-time ultrasound is a dynamic imaging technique that allows in utero orientation to the fetus. It permits rapid and efficient examination of fetal anatomy and provides a dynamic assessment of fetal well-being. The energy dissipation can be comparable to that in conventional ultrasonic B-mode scanning. We have used both linear and dynamically focused phased arrays for fetal examinations in conjunction with conventional gray scale B-mode scanners. The sophisticated phased-array real-time systems have demonstrated higher resolution and an improved gray scale as compared with the linear arrays. Applications of real-time ultrasound in obstetrics are discussed, and appropriate clinical examples are cited that illustrate the value of the technique for study of both normal and abnormal fetal development. We believe that this technique is the most sensitive method of detecting intrauterine fetal demise. The relative advantages and disadvantages of linear and dynamically focused phased arrays in obstetric evaluation are considered.

Abdomen↗
PubMed1979

Roentgenographic findings in a spectrum of uncommon tracheo-oesophageal anomalies.

Roentgenographic and clinical findings in a spectrum of malformations of the trachea and oesophagus are discussed. Five previously unreported patients representing four rare anomalies of tracheal agenesis, laryngotracheo-oesophageal cleft, oesophageal atresia with a tracheo-oesophageal (T-E) fistula to the proximal oesophageal pouch, and T-E fistula without oesophageal atresia (H-type fistula) are presented. These anomalies can be characterised by a failure in separation of the oesophagus and trachea and by atresia of either organ. All of the patients were diagnosed roentgenographically. Since the incidence of associated abnormalities is high in babies with these anomalies, a generalised embryological defect must be a basic assumption in any theory to explain the development of T-E anomalies.

Esophageal Atresia↗
PubMed1979

Computed tomography in the diagnosis of intra-abdominal abscesses.

The diagnosis of intra-abdominal abscess by radiographic means often relies on combining the results of several different imaging modalities. Computed tomography (CT) has been shown to be a safe, accurate and rapid diagnostic method of diagnosing these abscesses. Five patients with a variety of intra-abdominal abscesses are presented in whom the CT scan alone provided the correct diagnosis. The various imaging modalities available for the radiologic diagnosis of intra-abdominal abscess are described and are compared to CT diagnosis regarding their pitfalls.

Abscess↗
PubMed1979

Comparison of gray-scale ultrasonography and computed tomography in the evaluation of macrocrania in infants.

Head scans in 27 infants were done to compare the value of ultrasonography and computed tomography (CT) in the evaluation of macrocrania and encephalocele. Ultrasonography and CT correlated well with regard to anatomical information, especially in the assessment of the lateral and third ventricles. However, unlike CT, ultrasonography uses no ionizing radiation, is less expensive, eliminates sedation, and reduces artifacts due to motion and metal clips. In conjunction with an initial CT examination, ultrasonography is useful for serial evaluation of the lateral and third ventricles. It can also be helpful in assessing extraventricular fluid collections and suspected encephaloceles.

Cerebral Ventricles↗
PubMed1979

Type II choledochal cyst: ultrasonographic appearance.

The ultrasonic findings in a rare Type II choledochal cyst are described. In patients with a right upper quadrant mass in whom the clinical, ultrasonic, or radiographic findings are atypical for other etiologies, this diagnosis should be considered.

Biliary Tract Diseases↗