Search PubMed⌕ Search

Biomedical subjects

J W Charboneau

Publications and source records attributed to J W Charboneau.

At least 73 records · Page 4Linked to original sources
PubMed1987

Medullary thyroid carcinoma: role of high-resolution US.

Medullary thyroid carcinoma accounts for 10% of thyroid malignancies. Accurate determination of the extent of disease is important because surgery is required for initial treatment and recurrence. High-resolution (10-MHz) ultrasonography (US) of the neck was used to study 15 patients with medullary thyroid carcinoma; nine of the 15 had undergone thyroidectomy but had biochemical evidence of tumor recurrence. Metastatic cervical lymph nodes were detected with US in all 12 patients who had metastatic nodes at surgery, although these nodes were palpable in only four. Punctate bright echogenic foci were seen within some of the nodes in nine of the 12 patients (75%). Similar bright echogenic foci were seen within the primary intrathyroid tumor in five of the six patients who had not yet undergone thyroidectomy (83%). Pathologically, these foci correlated with deposits of calcium surrounded by amyloid, which is characteristic of medullary thyroid carcinoma. US is useful for the detection of nonpalpable recurrence of cervical metastatic lymph nodes, and because it is noninvasive and relatively inexpensive, it should be the first imaging investigation performed after thyroidectomy.

Adult↗
PubMed1987

Sensitivities of human jejunum, ileum, proximal colon, and gallbladder to cholecystokinin octapeptide.

We compared in humans simultaneous motor responses of the jejunum, ileum, proximal colon, and gallbladder (GB) to intravenous cholecystokinin octapeptide (CCK-OP). To gauge the physiological relevance of the doses of CCK-OP, intestinal motility and GB contraction were also quantified after a fatty meal. Eight healthy volunteers participated in both experiments. Six graded, 30-min intravenous infusions had a mean range of 2.2 to 73.2 pmol X kg-1 X h-1 of CCK-OP; these spanned from subphysiological (negligible contraction of GB) to pharmacological (producing intestinal symptoms and a 70-99% contraction of GB) levels. CCK-OP inhibited interdigestive cycles of motility, though in some persons fasting patterns persisted with doses of CCK-OP, which produced up to 50% reduction in GB volume. Motility indices of the ileum and proximal colon responded to CCK-OP by decreasing initially but then increasing with larger doses; motility of the jejunum increased gradually at all doses. Judged by the gallbladder's response to food (reduction in volume down from 74 to 29% of original volume), the physiological range of infused CCK-OP was approximately 5-16 pmol X kg-1 X h-1. Within this range of doses of CCK-OP, motility of the jejunum increased, whereas motility of the proximal colon was reduced. These data are consistent with CCK being a "physiological" mediator of intestinal motility in humans; responses of the intestine to the peptide appear to vary regionally.

Adult↗
PubMed1987

Altered sensitivity of the gallbladder to cholecystokinin octapeptide in irritable bowel syndrome.

We compared responses of the gallbladder to graded intravenous infusions of cholecystokinin octapeptide (CCK-OP) in normal controls (n = 8) and patients with irritable bowel syndrome (IBS) with predominant constipation (n = 8) or diarrhea (n = 8). The doses of CCK-OP ranged from subphysiological (negligible contraction of the gallbladder) to supraphysiological (90% contraction of gallbladder and abdominal side effects) amounts. All gallbladders contracted progressively in response to CCK-OP, and a Weibull model (power exponential function) described precisely the gallbladder's response to CCK-OP. Patients with IBS responded differently from normal patients; those with constipation contracted their gallbladders more and those with diarrhea contracted less in response to the peptide. Gallbladders were also stimulated with a high-fat, liquid meal; all patients' gallbladders contracted, but clear differences between groups could not be demonstrated postprandially. The results suggest that the smooth muscle of the gallbladder in IBS has an abnormal sensitivity to CCK-OP, and the results support the concept that IBS can be a generalized abnormality of the smooth muscle of the digestive tract.

Adult↗
PubMed1986

Computed tomography and ultrasonography of hepatoma.

Computed tomography (CT) scans and sonograms of 37 patients with hepatocellular carcinoma (hepatoma) were reviewed to determine the characteristics of the tumour and to compare the modalities in terms of accuracy in defining tumour morphology and ability to predict vascular invasion and extrahepatic spread. By CT, slightly over 50% of the tumours were multicentric, about 40% were solitary, and the rest were diffuse. About half of the hepatomas were heterogeneous in density before injection of contrast agent and most became enhanced in a non-uniform manner. In addition, about a quarter of the tumours either became visible or were better seen after injection of contrast agent. At sonography, approximately two-thirds of the neoplasms were thought to be solitary and one-third multicentric. The majority also had a mixed echo texture. Although the lesion was identified in all 13 patients who had both studies, sonography underestimated the extent of hepatic involvement in 38% of the cases. Sonography also failed to demonstrate lymphadenopathy that was detected by CT in two patients. In general, both techniques were effective in identifying vascular invasion. CT was very accurate in showing the extent of hepatic involvement but was unable to identify direct invasion of neighbouring structures. Because each technique has limitations in the evaluation of hepatoma, we believe that both should be performed if curative resection is being considered.

Adult↗
PubMed1986

Intraoperative ultrasonography of the pancreas in children.

In children, lesions of the pancreas often are small, and precise localization is required for optimal surgical management. We have used newer-generation real-time ultrasonography of the pancreas intraoperatively in seven children. Five of these children had hypoglycemia, hyperinsulinemia, and insulinomas; one had a persistent small pancreatic pseudocyst with a disrupted secondary duct, and one had familial pancreatitis with a remarkably enlarged duct and a stone. Two of the five with adenomas had multiple endocrine neoplasia syndrome I (MEN I syndrome); in them, ultrasonography localized several adenomas preoperatively and several additional adenomas intraoperatively. This allowed a 90% pancreatectomy with enucleation of small adenomas in the remaining head. One child had a nonpalpable insulinoma deep in the head of the pancreas; intraoperative ultrasonography localized the lesion and permitted successful enucleation. Another child with a small pseudocyst and a disrupted secondary pancreatic duct ultimately required surgical drainage; intraoperative ultrasonography of the inflammatory mass immediately localized the small pseudocyst and thus decreased the operative time. The child with familial pancreatitis appeared to require a surgical drainage procedure; however, intraoperative ultrasonography demonstrated that the stone had passed spontaneously just prior to operation and the duct size had returned to normal, eliminating the need for the drainage procedure at that time.

Adenoma, Islet Cell↗
PubMed1986

Parathyroid carcinoma: high-frequency sonographic features.

The authors reviewed the features on high-frequency (10 MHz), realtime sonograms of parathyroid carcinoma in eight patients to identify characteristics that could preoperatively distinguish malignant from benign lesions. The mean diameter of the eight carcinomas was 2.4 cm. They were typically ovoid or round and had a lobulated contour. The carcinomas were predominantly hypoechoic relative to the adjacent thyroid, but two of the eight contained both hypoechoic and hyperechoic regions, and three contained cystic spaces. Two carcinomas were grossly invasive on ultrasonographic (US) examination, although seven were proved histologically to be invasive. High-resolution US provides a noninvasive means to localize primary and locally recurrent parathyroid carcinomas preoperatively but fails to distinguish carcinomas from large adenomas reliably, except in cases with extensive invasion of adjacent structures.

Adult↗
PubMed1986

Benign pancreatic insulinoma: preoperative and intraoperative sonographic localization.

Twenty-nine patients with surgically proved benign pancreatic insulinoma were studied by preoperative or intraoperative sonography. Twenty-five patients had solitary pancreatic tumors; four had multiple tumors. Six of the patients with solitary insulinomas and one of the patients with multiple insulinomas had undergone previous unsuccessful exploration. Preoperative sonography was performed in 24 patients with solitary insulinomas, and 15 (63%) were localized. Intraoperative sonography was performed in 22 patients with solitary insulinomas, and 19 (86%) were visualized without having been previously located by palpation. Four of these visible solitary tumors (18%) were not detected by palpation at surgery. All the solitary insulinomas were detected with the combination of palpation and intraoperative sonography. In each of the six patients with solitary insulinoma who had undergone previous surgery, the tumor was visible with intraoperative sonography, which also demonstrated nonpalpable insulinomas in two of the four patients with multiple tumors. Preoperative real-time sonography is a sensitive, noninvasive, inexpensive method for localization of insulinoma. Intraoperative high-frequency sonography is a highly sensitive method for the detection of insulinoma. Intraoperative sonography is also valuable to determine the relationship of the insulinoma to pancreatic and bile ducts and thereby facilitate safe enucleation.

Adenoma, Islet Cell↗
PubMed1985

Focal nodular hyperplasia and hepatic adenoma: comparison of angiography, CT, US, and scintigraphy.

The authors reviewed 23 cases of focal nodular hyperplasia and 13 cases of hepatic adenoma, all of which were confirmed pathologically. All solitary masses that exhibited normal or increased uptake of technetium 99m-sulfur colloid were shown to be hyperplasia; while previous criteria such as a central blood supply on angiograms or a central scar on computed tomography (CT) or ultrasound (US) scans were helpful, they were relatively infrequent. A mass that was slightly hypodense and homogeneous on a CT or US scan and highly vascular with an intense capillary stain on an angiogram was almost always hyperplasia. Acute hemorrhage within a focal hepatic tumor was common in adenoma but did not occur in hyperplasia.

Adenoma↗
PubMed1985

Testicular neoplasms: 29 tumors studied by high-resolution US.

High-resolution (10-MHz) ultrasonography produces extremely detailed anatomic images of the testis. The sonographic features most helpful in detecting tumors are mass, bright echogenic foci, and diffuse parenchymal texture change. Of 29 patients with testicular neoplasms, 21 (72%) had one or more masses, 19 (66%) had one or more echogenic foci, and nine (31%) had a diffuse parenchymal texture change. Bright echogenic foci were present in six (86%) of seven testes that had a regressed germ-cell tumor. In an attempt to define the histologic features of bright echogenic foci, we performed needle localization under real-time guidance on four operative specimens. We observed immature bone and cartilage, calcification, tubular atrophy and fibrosis, and focal noncalcific scarring. Discovery of occult testicular neoplasms was common (9/29); four patients were thought to have had "extragonadal" germ-cell tumors before abnormalities were found on the sonograms.

Adolescent↗
PubMed1985

Postoperative parathyroid high-frequency sonography: evaluation of persistent or recurrent hyperparathyroidism.

Sixty consecutive postoperative patients with recurrent or persistent hyperparathyroidism were scanned before reoperation using high-frequency (10 MHz) real-time sonography. The sonograms were interpreted prospectively, and the results correlated with subsequent surgical findings to determine the diagnostic accuracy of this technique in the localization of enlarged parathyroid glands. A total of 59 abnormal glands were found in 51 patients at operation: 45 in the neck and 14 in the mediastinum. Sonography identified 37 of the 45 cervical glands for a sensitivity of 82% in the neck. The mediastinum cannot be evaluated by sonography due to the bony thoracic cage, although if the mediastinal glands are included, the overall sensitivity was 63%. In the 14 patients with negative neck explorations but positive mediastinal explorations, sonography was negative in 12 patients, but false-positives were suspected in two patients, yielding a specificity of 86% in the neck. High-frequency sonography is a sensitive, rapid, and noninvasive technique for localizing enlarged cervical parathyroid glands in patients with recurrent or persistent hyperparathyroidism.

Adolescent↗