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Biomedical subjects

R C Sanders

Publications and source records attributed to R C Sanders.

At least 91 records · Page 5Linked to original sources
PubMed1986

Ultrasonography of prostatic carcinoma employing amplitude-enveloped (AM) and frequency-demodulated (FM) imaging: in vivo, in vitro, and pathologic correlation.

Thirty patients with biopsy proven carcinoma of the prostate were examined with transrectal (TR) (5-MHz linear array transducer) and transabdominal (TA) (3-MHz sector scanner) ultrasonography prior to prostatectomy. All patients had clinical stage A (n = 5) or B (n = 25) disease. Following retropubic radical prostatectomy, in vitro waterbath studies of the resected specimens were performed obtaining both conventional amplitude-enveloped (AM) images and frequency-demodulated (FM) images. The ability of each imaging modality (TR, TA, AM, FM) to detect the cancerous lesion was determined, and in all cases correlation with pathology was obtained. Transabdominal suprapubic ultrasonography did not prove helpful in detecting early carcinoma. Longitudinally oriented linear array transrectal ultrasonography was positive in nearly two thirds of the patients. Insignificantly lower positive correlation with pathologic findings was obtained from in vitro AM images; the lesions were often better visualized on transverse than on longitudinal images. The highest correlation with pathology was obtained from the in vitro frequency-demodulated images.

Aged↗
PubMed1985

Molecular epidemiology of human rotavirus infections.

Recognition of rotaviruses as a major aetiological agent of acute gastroenteritis in infants and young children has prompted the investigation of their epidemiology by molecular techniques. Genome analysis by electrophoretic separation of the RNA segments has been widely used to distinguish virus isolates and to monitor patterns of virus transmission. Examination of virus isolates from different epidemics has clearly demonstrated the existance of extensive genomic variation in viruses circulating in large communities; with the co-circulation of a number of viruses of differing electrophoretype. Preliminary studies using the more advanced techniques of oligonucleotide mapping and hybridization analysis have suggested that variation among the viruses may occur by processes involving both "drift" and "shift". Because of their ease and specificity the new hybridization analysis techniques should greatly facilitate both the rapid diagnosis of rotavirus infections, and the solution of many epidemiological and evolutionary questions. Continued and expanded use of molecular techniques for the study of the epidemiology of rotavirus infections will be required to manage future outbreaks and to effect long term control measures.

Electrophoresis, Polyacrylamide Gel↗
PubMed1985

Epidemiological aspects of rotavirus infection in young Gambian children.

Rotavirus gastro-enteritis in young Gambian children has its maximum impact on infants after the age of one month, in whom it produces short, well-defined annual winter epidemics with clinical dehydration in up to 18% of those infected. Sporadic infection was observed in neonates who were often asymptomatic, throughout one year but not in the subsequent year. In two consecutive years studied there was a major change from subgroup I, serotype 2 to subgroup II, serotypes 1 and 3. This could have contributed to the failure of children to develop protective immunity against sequential disease following an infection during infancy. If rotavirus morbidity in this community is to be notably reduced by a vaccination programme it would need to be carried out in early infancy prior to the winter season. Evaluation of a type-specific vaccine should include monitoring secular changes in rotavirus serotypes throughout subsequent epidemics.

Diarrhea, Infantile↗
PubMed1984

Molecular epidemiology of human rotaviruses. Analysis of outbreaks of acute gastroenteritis in Glasgow and the west of Scotland 1981/82 and 1982/83.

The molecular epidemiology of rotavirus infections in Glasgow and the west of Scotland during 1981/82 and 1982/83 was investigated by electron microscopy, ELISA testing and RNA migration pattern analysis. In 1981/82, rotaviruses of both the 'long' and the 'short' electropherotype (in different variants) co-circulated from the onset throughout the winter peak of the outbreak. Approximately 80% of the children were infected during the first year of life. No differences in incidence were found between sexes. In 1982/83 the isolated rotaviruses were almost exclusively of the 'long' electropherotype (in different variants) and 36% of the children were infected beyond the first year of life. Rotaviruses of the 'long' electropherotype serologically were of subgroup II and serotype 1 and those of the 'short' electropherotype of subgroup I and serotype 2.

Acute Disease↗
PubMed1984

Enzyme-linked immunosorbent assays based on polyclonal and monoclonal antibodies for rotavirus detection.

We describe two enzyme-linked immunosorbent assays for rotavirus antigen in feces, which were designed to be as sensitive and specific as possible, and easy to use anywhere. Both are indirect methods, using the antibody capture method, but the second assay utilizes a rotavirus group-specific monoclonal "detecting" antibody instead of the hyperimmune polyvalent guinea pig antisera used in the first assay. Both tests were found to be more sensitive than electron microscopy for detecting virus. To develop these tests, solid phase, antiserum production methods, treatment of the test antigen with EDTA, substrate, stability of reagents, and the need for confirmatory "blocking" tests were all examined. The first assay described is that used at present by the World Health Organization for their worldwide diarrheal disease control program.

Animals↗
PubMed1984

The sonographic distinction between neonatal multicystic kidney and hydronephrosis.

Distinction between multicystic kidney and hydronephrosis, the two most common causes of neonatal abdominal masses, is important because of differences in management; however, these two entities may have a similar ultrasonographic appearance. Sonograms of 22 cases of multicystic kidney and hydronephrosis were retrospectively reviewed without knowledge of the pathologic findings to determine if the sonographic patterns were sufficiently distinct to be usable in clinical diagnosis. Nine of the 22 cases were correctly diagnosed with ultrasound as multicystic kidney, 6 cases were correctly diagnosed as hydronephrosis, and 7 cases of pathologically proved multicystic kidney were incorrectly diagnosed as hydronephrosis. Four of these incorrect diagnoses occurred in cases of the hydronephrotic type of multicystic kidney. An additional 9 cases were reviewed with knowledge of the pathologic results. It is concluded that sonography is accurate at differentiating classic multicystic kidney disease from moderate hydronephrosis; however, there is often considerable difficulty in distinguishing severe hydronephrosis from the hydronephrotic form of multicystic kidney disease.

Diagnosis, Differential↗
PubMed1984

Fatty infiltration of the liver: ultrasonographic and computed tomographic correlation.

To evaluate the accuracy of ultrasonography in diagnosing fatty infiltration of the liver (FIL), the authors compared gray-scale B-mode ultrasonography and unenhanced computed tomographic (CT) liver images in a study of 47 patients. The CT scans, which served as the diagnostic standard, were classified as normal, Grade 1 (mild FIL), Grade 2 (moderate FIL), and Grade 3 (severe FIL). Applying predetermined sonographic textural criteria, two experienced radiologists independently graded each ultrasound study for the presence and severity of FIL. The overall accuracy of ultrasonography in detecting FIL was 85 per cent, with 100 per cent sensitivity and 56 per cent specificity. The sonographic/CT correlation in grading the severity of FIL was particularly good for Grade 2 and Grade 3 FIL. Ultrasound is a sensitive and reasonably accurate diagnostic tool in assessing fatty infiltration of the liver.

False Positive Reactions↗
PubMed1984

Xanthogranulomatous pyelonephritis: sonographic--pathologic correlation of 16 cases.

Xanthogranulomatous pyelonephritis (XGP) is an uncommon renal inflammatory disease characterized by the destruction and replacement of normal parenchyma by sheets of lipid-laden histiocytes. The process may be diffuse or segmental. Sonograms of 16 cases of XGP (13 diffuse, three segmental) were retrospectively reviewed and correlated with their pathologic findings. The typical case of diffuse XGP demonstrates the following: renal enlargement, replacement of normal architecture by multiple fluid-filled masses, pelvic contraction or only moderate separation of the central echo complex, and a pelvic calculus. Although most cases have a large staghorn calculus, its sonographic demonstration may be difficult, perhaps as a consequence of peripelvic fibrosis. Atypical cases of diffuse XGP mimic pyelonephrosis with massive hydronephrosis and fluid--debris levels. In these atypical cases, a staghorn calculus is often conspicuously absent. Segmental XGP is recognized as an area of parenchymal destruction surrounding one calyx or one pole of duplication. Segmental XGP should be distinguished from focal xanthogranulomatous inflammation of the kidney, which is a distinct pathologic entity (cortical location, no pelvic communication, absent pyelitis). When typical gross pathologic features are present, sonography should make possible accurate identification of diffuse and segmental XGP.

Adult↗
PubMed1983

Mid-trimester fetal ultrasound: diagnostic dilemmas.

Two cases are reported in which an unusual ultrasound finding preceded diagnostic amniocentesis and led to further work-up. In both cases a decision was made to terminate the pregnancy. One fetus in which a neck mass was detected by ultrasound was shown to be normal on post-mortem examination. The second fetus was aborted because of Rh sensitization and had the abnormality seen by ultrasound. However, this lesion, calcified intrahepatic plaques, had no presumed pathological significance. These cases suggest caution in the interpretation of results obtained with the new technologies used for prenatal diagnosis.

Abortion, Therapeutic↗
PubMed1983

A prospective study of computed tomography and ultrasound in the detection and staging of pelvic masses.

Findings from computed tomography (CT) and ultrasound (US) examinations of 74 patients who were clinically thought to have pelvic masses and of 110 patients who had possible recurrence of pelvic tumors were analyzed. There was no significant difference in the ability of the two modalities to identify masses or to predict disease extent. Although both CT and US failed to detect some examples of spread outside of the pelvis, overstaging (apart from two cases of unconfirmed parametrial spread) did not occur with CT and occurred only once with US. The sensitivity was 0.96 for CT and 0.91 for US in the detection of pelvic masses. Both modalities had an accuracy of 0.81 in the detection of recurrent disease.

Diatrizoate↗
PubMed1983

Doppler ultrasound and maternal erythrocyte fragility.

Maternal erythrocyte fragility was studied in eight controls and in 16 women exposed to Doppler ultrasound monitoring during labor. Blood samples were taken before and after Doppler monitoring and no significant change in erythrocyte fragility was seen, although there was a trend toward increased fragility in patients exposed continuously for more than seven hours.

Adolescent↗