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Biomedical subjects

R C Sanders

Publications and source records attributed to R C Sanders.

At least 55 records · Page 3Linked to original sources
PubMed1990

Cholecystokinin prevents parenteral nutrition induced biliary sludge in humans.

Long term total parenteral nutrition (TPN) induces biliary sludge and formation of gallstones. Cholecystectomy is hazardous in these patients because of the underlying medical problems. Therefore, a randomized, double-blind controlled study was designed to test the hypothesis that daily administration of cholecystokinin-octapeptide (CCK-OP) prevents the formation of biliary sludge in humans receiving long term TPN. Adult patients receiving TPN for more than 21 consecutive days were studied. After randomization of 15 patients, the study was concluded because statistical significance was achieved. Eight patients received saline solution (placebo) intravenously and seven received CCK-OP (50 nanograms per kilogram) intravenously over a ten minute period daily. The groups were similar with respect to age, sex, diagnosis, liver function tests, amylase levels, total TPN time and time of study. All of the patients underwent weekly ultrasound studies. Volume and emptying studies of the gallbladder in response to the study drug were performed after one week. None of the patients receiving CCK-OP had sludge whereas five of eight of the patients receiving placebo had sludge (p less than 0.02). The results of emptying studies showed significant contraction of the gallbladder in those in the CCK-OP group but not in the placebo group. These data suggest that CCK-OP given intravenously daily prevents TPN induced stasis and sludge of the gallbladder. We conclude that CCK-OP should be used as routine prophylaxis against biliary sludge and formation of gallstones in patients receiving long term TPN.

Adult↗
PubMed1990

Fetal genitourinary tract anomalies: evaluation, operative correction, and follow-up.

The prenatal diagnosis of a genitourinary anomaly was made in 53 fetuses. Sonographic findings, antenatal course, and postnatal treatment and outcomes were examined. No interventional therapy was undertaken in utero, and the natural history could be examined in the 44 of 53 (83%) who did not electively terminate their pregnancies. Twenty-three of the total 53 (43%) had unilateral disease and 30 (57%) had bilateral involvement. Thirty-five of 53 (66%) survived, with 22 undergoing operative therapy postnatally. In all but one of the 35 survivors, the anomaly was isolated to the genitourinary tract, and the majority of surviving fetuses had unilateral disease. Oligohydramnios was present in only three of 35 survivors, and none had severe oligohydramnios. Nine of 53 women underwent termination of pregnancy and nine others experienced a neonatal death. All 18 of their fetuses had bilateral disease, with oligohydramnios present in 14 (78%). All five fetuses with chromosomal abnormalities were found in this group of 18. The majority of fetuses with a genitourinary anomaly will do well postnatally. Pulmonary hypoplasia, extrarenal anomalies, and chromosomal defects are frequent findings in the minority with poor outcomes. A multidisciplinary approach to management of the pregnancy with a fetal genitourinary tract anomaly is essential to optimize outcome.

Abortion, Eugenic↗
PubMed1990

Prenatal ultrasonic detection of anomalies with a lethal or disastrous outcome.

Although rare, a number of fetal anomalies can be detected with ultrasound in which the prognosis is either fetal death or minimal development. Anomalies of this type include anencephaly, holoprosencephaly, hydranencephaly, iniencephaly, cystic hygroma with hydrops, cystadenomatoid malformation of the lung with hydrops, conjoined twins of some types, renal agenesis, bilateral renal dysplasia, lethal dwarfing syndromes, and some forms of hydrops. Syndromes in which the severe form only are fatal include intracranial teratoma, encephalocele, pentalogy of Cantrell, vein of Galen aneurysm, the limb body wall complex, and infantile polycystic kidney. Sonographic findings of these conditions and other rarer lethal lesions are reviewed.

Abortion, Eugenic↗
PubMed1989

Temporal relationship between A1 adenosine receptor upregulation and alterations in bicuculline seizure susceptibility in rats.

The temporal requirements for theophylline-induced upregulation of A1 adenosine receptors and elevation of seizure threshold were examined. Chronic theophylline exposure (75 mg/kg twice daily) elicited a significant upregulation of [3H]cyclohexyladenosine ([3H]CHA) binding sites following 7 and 14 days of treatment. Alterations in seizure threshold followed a similar temporal pattern of development. The reversibility of theophylline-induced upregulation of high affinity [3H]CHA binding sites was complete at 10 days following cessation of theophylline administration, while the alteration of seizure threshold required 21 days to return to control values.

Adenosine↗
PubMed1989

Determination of canine prostatic size in situ: comparison of direct caliper measurement with radiologic and transrectal ultrasonographic measurements.

The use of transrectal ultrasonography to estimate canine prostatic size in situ was evaluated and compared to that of direct measurement via calipers and an in situ radiologic procedure. The length, width, and depth of prostates were measured by transrectal ultrasound in both the transverse and sagittal planes from which prostatic volume was calculated. Prostatic volumes were subsequently transformed into prostatic weights using the following nomogram: prostatic Weight (g) = 0.602 x prostatic Volume (cm3) + 1.16. Prostatic weights estimated by ultrasound as well as by direct measurement with caliper were similar (P greater than 0.10) to the true gravimetric weight; however, prostate weights estimated by the radiological X-ray procedure were significantly (P less than 0.01) lower. The relationship between true gravimetric prostate weight and that estimated by ultrasound was described by the following regression equation: estimated weight (g) = 1.127 gravimetric weight (g) - 1.665; r = 0.900; P less than 0.001; n = 23. In summary, the results of this study demonstrate that transrectal ultrasonography can be used to accurately predict canine prostatic weight.

Animals↗
PubMed1989

Evaluation of transrectal ultrasound in the early detection of prostate cancer.

To determine the ability of transrectal ultrasound to detect early localized prostate cancer, unsuspected (nonpalpable) cancer in the contralateral lobe of patients undergoing radical prostatectomy for clinically localized disease was evaluated. A total of 59 patients with palpable prostate cancer clinically confined to 1 lobe underwent transrectal ultrasound before radical prostatectomy and step-sectioning of the radical prostatectomy specimen. Transrectal ultrasound was performed with 5 or 7 MHz. real-time transrectal units. Pathological findings in these 59 cases revealed no tumor in the contralateral lobe in 34 (58%) and the presence of unsuspected tumor in 25 (42%). Transrectal ultrasound detected 13 of 25 unsuspected cancers for a sensitivity of 52%. Of 34 patients with no contralateral lobe lesion transrectal ultrasound was correct in 23 for a specificity of 68%. The positive and negative predictive values for transrectal ultrasound in this study group were 54 and 66%, respectively. There was no significant difference in the pathological size of the clinically suspected and clinically unsuspected cancers as measured by average largest dimension, and transrectal ultrasound sensitivity did not correlate with the size of the cancer. Based on careful sonopathological analysis, transrectal ultrasound may not be a good method to detect clinically unsuspected prostate cancer and the false positive rate would appear to be high.

Humans↗
PubMed1989

Lethal fetal anomalies: sonographic demonstration.

Sonographic demonstration of a lethal fetal anomaly may dramatically alter obstetrical management. For example, cesarean section for fetal distress may not be performed if it is known that the fetus will not survive outside the uterus. The author describes the common fetal anomalies that are predictably fatal.

Bone and Bones↗
PubMed1989

Relationship between image quality and ultrasound exposure level in diagnostic US devices.

Ultrasonographic B-mode images were obtained at various exposure levels with three real-time diagnostic scanners. Adult human and tissue-equivalent phantom images were compared in terms of diagnostic content and depth of penetration. For the exposure level settings used, spatial-peak pulse-average intensities ranged from approximately 10 to 500 W/cm2. At the 3.50-3.75-MHz nominal frequencies used in the study, images of the human abdomen showed little discernible change in quality with varying exposure levels. However, phantom tests confirmed that depth of penetration is a function of exposure level. The results suggest that a judicious use of exposure level and receiver gain controls can be a practical means for minimizing patient exposure to ultrasound without sacrifice of diagnostic effectiveness.

Abdomen↗
PubMed1989

Sonographic observations in a patient with typhlitis.

The sonographic findings in a patient with typhlitis are presented. Sonography showed a solid mass with a "target" sign in the right lower quadrant, continuous with the ascending colon. In addition to suggesting the diagnosis, sonography was helpful in the follow-up examination of the patient because it was able to assess the gradual decrease in the thickness of the bowel wall and ultimate resolution of the inflammatory process.

Anemia, Aplastic↗
PubMed1989

Wrongful life and wrongful birth. Implications for diagnostic sonography.

We trust that this communication will further the understanding of the concepts involved in wrongful life and wrongful birth and will assist the conduct of medical practice in such a way to minimize risks to patients and ultrasound physicians with regard to their liability. When these physicians are involved in wrongful life cases, we believe that the concepts presented will assist them in understanding the legal and societal environment in which they find themselves. We hope also that this communication may assist the defense attorney to more effectively prepare a response to the plaintiff's legal theory. Knowledge should provide understanding, if not relief.

Expert Testimony↗
PubMed1988

Chronic theophylline exposure increases agonist and antagonist binding to A1 adenosine receptors in rat brain.

Chronic treatment of rats with theophylline (75mg/kg twice-daily for 21 consecutive days) significantly increased the specific binding of [3H]CHA and [3H]DPCPX in cerebral cortical membranes. The absolute increase in the number of binding sites following theophylline treatment was approximately the same for each ligand, although this number represents a larger percentage of the total sites available to [3H]CHA. Saturation analysis of [3H]DPCPX binding indicated that theophylline treatment increased the maximum number of binding sites from 799 +/- 13 to 920 +/- 22 fmol/mg protein, while the affinity of [3H]DPCPX for A1 receptors was unaltered. These results suggest that chronic theophylline exposure produces both an increase in the number of A1 adenosine receptors and an enhancement of coupling of these receptors to G proteins.

Adenosine↗
PubMed1988

Renal dysplasia: sonographic findings.

In 38 pediatric patients (predominantly neonates) with a proved pathologic diagnosis of renal dysplasia, a variety of sonographic appearances were seen. When the obstruction was at the level of the ureteropelvic junction (12 patients, 12 kidneys), the typical appearance was of a large kidney containing multiple large or moderate-sized cysts. When the obstruction was at the level of the distal ureter (14 patients, 14 kidneys), a smaller kidney containing a few cysts of variable sizes was usually seen. When the obstruction was at the level of the urethra (eight patients, 13 kidneys), the kidney was typically small with few or no cysts. In four patients (seven kidneys) in whom no cause of the obstruction was evident, the kidneys were small and echogenic. There was one case of segmental dysplasia.

Adolescent↗
PubMed1988

Neonatal ovarian cysts: sonographic-pathologic correlation.

The authors reviewed the prenatal (11 infants) and postnatal (17 infants) sonograms and the clinical, surgical, and pathologic findings in 17 infants with an ovarian cyst to determine the sonographic features and natural history of neonatal ovarian cysts. An uncomplicated cyst (nontwisted, nonhemorrhagic) was completely anechoic and the cyst wall was imperceptible with sonography (five cases). A twisted or hemorrhagic cyst was cystic with a fluid-debris level, cystic with a retracting clot, septated with or without internal echoes, or solid (12 cases). These complicated cysts contained liquid and/or organized hematoma. Eleven of the 12 complicated cysts had a thin, highly echogenic wall. Cyst torsion commonly occurred in utero and could be diagnosed on prenatal sonograms by a typical sonographic appearance (eight cases). All of these infants were asymptomatic after birth. Four infants with hemorrhagic or twisted cysts were symptomatic. All cysts except one that resolved spontaneously were treated surgically, including three twisted cysts that showed no change in size over a 1-8-month interval. All of the cysts were of follicular origin.

Female↗
PubMed1988

Prenatal diagnosis of sacrococcygeal teratoma: sonographic-pathologic correlation.

The prenatal sonograms of 15 fetuses with sacrococcygeal teratoma were reviewed to determine the sonographic appearance and the role of sonography in the obstetric management. Each tumor appeared as a large mass arising from the fetal rump. The teratomas exhibited three sonographic patterns: nine were mixtures of cystic and solid components in equal proportions, four were predominantly solid with a few scattered anechoic areas, and two were unilocular cystic masses. Calcifications were detected in six cases. There was no correlation between the sonographic appearance and the presence of immature or malignant components. Ultrasonography allowed visualization of an intraabdominal component in six cases and assessment of findings that were of prognostic importance. Prenatal detection and size determination of the external component can play an important role in planning obstetric management because fetuses with a large tumor should be delivered by cesarean section to avoid dystocia and catastrophic hemorrhage during delivery.

Female↗
PubMed1988

Renal involvement in AIDS: sonographic-pathologic correlation.

Renal sonography was performed in 36 patients with clinical and/or laboratory evidence of AIDS, usually because of deteriorating renal function. In 15 patients, histopathologic specimens were reviewed to characterize renal pathologic changes underlying the sonographic findings. Sonographic evaluation included determination of renal size and cortical echogenicity according to a standard grading system. Pathologic specimens were evaluated for tubular and glomerular abnormalities. Sonography showed either normal-sized or enlarged kidneys with grade I cortical echogenicity in 13 patients (36%), grade II in three patients (8%), and grade III in five patients (14%). Fifteen patients (42%) had normal renal echogenicity. In addition to focal segmental glomerulosclerosis the pathologic examination showed different degrees of tubular abnormalities. Striking, irregularly dilated, infolded tubules with flattened epithelium and intratubular deposits of proteinaceous material, and sometimes cystlike formation involving the medulla and cortex, were seen in two patients with grade III kidneys, and mild dilatation of the tubules was seen in four patients with grade I disease. Moderate tubular dilatation was observed in one patient with grade I disease. No significant tubular abnormality was seen in one patient with grade I disease or in seven patients with normal renal echogenicity. Although glomerular changes contribute to the increase in renal echogenicity, we postulate that the main factors responsible for the increased echogenicity in AIDS nephropathy are the striking tubular abnormalities seen in these patients.

Acquired Immunodeficiency Syndrome↗
PubMed1988

The variable sonographic appearances of ovarian teratomas: correlation with CT.

To better understand how the internal composition of ovarian teratomas influences their sonographic features, we compared their sonographic and CT appearances in 23 cases. Sixteen lesions had a mixed echo texture, with hypoechoic as well as echogenic components; two were anechoic and five were entirely echogenic. Correlation with the CT images showed that the fat present in most teratomas had variable sonographic appearances. Pure sebum was anechoic or hypoechoic, but fat intermixed with hair strands was echogenic and often attenuated the sound beam because of the numerous tissue interfaces created within the mass. The hypoechoic component of the teratoma corresponded, on CT, to low-attenuation fat in 12 tumors and to fluid in five. Most teratomas contained a dermoid plug, a protuberance arising from the tumor wall and containing hair follicles and often fragments of bone or teeth. On sonography, all dermoid plugs were seen as an echogenic mass, often associated with distal acoustic shadowing and protruding into the hypoechoic portion of the teratoma. When the dermoid plug was large and occupied most of the tumor, the entire teratoma appeared echogenic, with no discernible anechoic component. We found that three factors greatly affected the sonographic appearance of ovarian teratomas: the size of the dermoid plug, the presence and location of calcified elements, and the histologic composition of the fatty component.

Adult↗
PubMed1988

Comparison of transvaginal and transabdominal sonography in the detection of early pregnancy and its complications.

Ninety women with a positive pregnancy test and signs and symptoms of threatened abortion or ectopic pregnancy had endovaginal and abdominal sonography in order to compare the value of the two techniques for the detection of gestational abnormalities. Either a normal delivery occurred or surgical and/or pathologic confirmation of the diagnosis was available in all cases. Fifty-five women had normal intrauterine pregnancies, 22 had ectopic pregnancies, seven had blighted ova, and six had missed abortions. All 55 normal intrauterine pregnancies were detected by endovaginal sonography, while only 11 (20%) were diagnosed by transabdominal sonography. The yolk sac, fetal pole, and fetal heart motion were seen as early as 34 days from the last menstrual period with endovaginal sonography, compared with 42 days with transabdominal sonography. Fetal heart motion was detected with endovaginal sonography in fetal poles with a crown-rump length of 3 mm or greater, whereas the fetal pole had to be at least 6 mm before fetal heart motion could be detected with the transabdominal technique. In the 22 ectopic pregnancies, a specific diagnosis of an extrauterine sac containing a fetal pole with heart motion or yolk sac was possible in three cases with the endovaginal technique, but it was not possible in any case with transabdominal sonography. Both techniques showed that each of the seven patients with final diagnosis of blighted ova had a gestational sac that was 1.7 cm or larger without visualization of the fetal pole or yolk sac. All six missed abortions were detected by endovaginal sonography, but only three were diagnosed on transabdominal sonograms. Our findings show that endovaginal sonography is more sensitive than transabdominal sonography in the detection of early pregnancy and its complications.

Female↗