Search PubMed⌕ Search

Biomedical subjects

S Wallace

Publications and source records attributed to S Wallace.

At least 433 records · Page 24Linked to original sources
PubMed1978

Laryngocele.

Laryngocele occurs more commonly than the literature indicates. Until recently, most were diagnosed clinically in the symptomatic patient. Although laryngocele is usually asymptomatic, greater numbers are being diagnosed because more patients suspected of head and neck cancer are undergoing sophisticated diagnostic radiographic procedures. Of 2,068 patients studied at M.D. Anderson Hospital and Tumor Institute for suspected laryngeal or hypopharyngeal cancer, 87 (4.2%) had laryngoceles. Three types of laryngocele are recognized: internal, external, and combined. They may be congenital or acquired and occur at any age. The coexistence of carcinoma and laryngocele has been discussed often enough in the literature to suggest a direct relationship; however, this series yielded no substantive evidence to implicate laryngocele as a precursor of carcinoma. The radiographic procedures currently used which readily establish the presence of laryngoceles are lateral soft tissue radiography of the neck, anteroposterior tomography of the larynx, and contrast laryngography.

Humans↗
PubMed1977

Selective inhibition of in vitro DNA synthesis dependent on phiX174 compared with fd DNA. I. Protein requirements for selective inhibition.

Crude extracts of Escherichia coli selectively convert fd viral DNA and not phiX174 DNA to duplex DNA via a complex series of reactions one of which involves RNA polymerase. Reactions leading to formation of fd duplex-replicative (RFII) structures have been reconstituted with purified proteins from E. coli. Maximal synthesis requires the combined action of E. coli binding protein, DNA elongation factor I, DNA elongation factor II preparations (which are a mixture of dna Z and DNA elongation factor III), DNA polymerase III, DNA-dependent RNA polymerase, Mg2+, dATP, dGTP, dCTP, dTTP, and ATP, GTP, CTP, and UTP. In contrast to crude extracts of E. coli, purified protein fractions do not distinguish between fd DNA and phiX174 DNA in duplex DNA formation. The addition of crude fractions of E. coli to the purified components listed above selectively permits fd RFII formation and prevents phiX RFII formation. This selective inhibition was used as an assay to isolate proteins essential for this phenomenon; they include RNase H, discriminatory factor alpha, and discriminatory factor beta.

Adenosine Triphosphatases↗
PubMed1977

Angiographic changes of head and neck chemodectomas following radiotherapy.

Angiography is useful in following selected patients with chemodectoma of the head and neck treated by radiotherapy. Comparison of preradiotherapy and post radiotherapy angiograms in three patients revealed a decrease in the following: size of feeding arteries, size of tumor, intensity of tumor opacification, and degree of venous shunting. When chemodectomas are not amenable to physical examination and when the question of radiotherapy complication vs further growth of tumor arises, postradiotheraphy angiography may be of particular value.

Adult↗
PubMed1977

Lymphangiography in the determination of the extent of metastatic carcinoma: the potential value of percutaneous lymph node biopsy.

In determining the extent of disease in patients with carcinoma, lymphangiography when read as positive has an accuracy of 90 to 95%. When considered negative 15 to 20% prove to have metastatic disease. the recent use of percutaneous transperitoneal aspiration biopsy of previously opacified lymph nodes has enhanced the value of lymphangiography. Eighty percent of the aspiration biopsies yield sufficient tissue for cytologic diagnosis.

Adult↗
PubMed1977

Renal adenocarcinoma in adolescence and childhood: emphasis on angiographic findings.

Four cases of hypernephroma occurring in the first 2 decades of life are presented. Of these patients 3 were adolescents and 1 was a child. Angiography was used in 8 cases, including 6 that were reported previously and 2 from the present series. Sparse neovascularity, faint tumor stain and no arteriovenous shunting were the manifestations in 4 cases. Differentiation from Wilms tumor could be difficult in this circumstance.

Adenocarcinoma↗
PubMed1977

Changes in the lymphatic dynamics after retroperitoneal lymph node dissection.

Lymphatic dynamics in the retroperitoneal space are altered after retroperitoneal lymph node dissection. Obstruction with or without visible collaterals is seen frequently. Lymphaticovenous communications and lymphocysts are also common findings. The immediate sequelae are of minor importance, although the mass effect of lymphocysts may be serious. The collateral pathways and lymphaticovenous anastomoses may result in the appearance of metastases in unusual sites.

Adolescent↗
PubMed1977

Transperitoneal percutaneous retroperitoneal lymph node aspiration biopsy.

Percutaneous aspiration biopsies of opacified retroperitoneal lymph nodes, and retroperitoneal, intraperitoneal and paraspinal masses were successfully accomplished in 14 of 17 patients. A 23-guage needle was utilized for the procedure which is performed under fluoroscopic guidance. Metastatic carcinoma, sarcoma and melanoma were readily identified by aspiration biopsy while the diagnosis of lymphoma, especially as to type, was more difficult. No significant complications have resulted from the passage of the needle through the peritoneal cavity.

Adolescent↗
PubMed1977

Percutaneous fine needle aspiration biopsy of pancreatic and other abdominal masses.

Percutaneous fine needle aspiration biopsy of 18 patients with pancreatic masses, and 19 with other intra-abdominal tumors, showed it to be a safe, accurate procedure. A diagnostic biopsy yield was obtained in over 85% of the cases without clinical complications. Indications for fine needle biopsy are: (a) to avoid surgery by obtaining a histologic diagnosis; (b) to determine the staging of a neoplastic disease process; and (c) to facilitate treatment planning. The technique of "skinny needle" biopsy is discussed.

Abdominal Neoplasms↗
PubMed1977

Fine needle aspiration biopsy of retroperitoneal lymph nodes and abdominal masses: an updated report.

Percutaneous fine needle aspiration biopsy of retroperitoneal lymph nodes and abdominal masses was performed in 109 patients. Eighty-five per cent of the aspiration biopsies yielded sufficient cytologic material for a correct diagnosis. Indications include confirmation of lymphangiographic findings and the establishment of a histologic diagnosis in lieu of surgery. No significant complications were encountered.

Abdominal Neoplasms↗
PubMed1977

Transcatheter splenic arterial occlusion: an experimental study in dogs.

Three techniques of transcatheter splenic arterial occlusion were evaluated in dogs. Angiographic, hematologic, and morphologic studies were done up to 9 weeks postocclusion. All animals showed hematologic changes characteristic of depressed splenic function; the degree and duration of these changes depended upon the technique. Alterations in histology including vascular congestion, infarction, and fibrosis, were also dependent upon the method used and the time elapsed after occlusion. Celiac angiography demonstrated the extent of collateral circulation and degree of recanalization of the occluded vessels. Potential clinical applications are discussed.

Angiography↗
PubMed1977

The use of prostaglandin E1 for enhanced visualization of the splanchnic circulation.

A single bolus injection of prostaglandin E1 (5-7.5 microgram) into the superior mesenteric, hepatic or pancreatico-duodenal arteries was employed as a pharmacoangiographic aid in 22 patients. Good quality arterial phase and greatly enhanced portal venograms were obtained. No significant complications were observed. The authors found the technique useful in diagnosis of primary and metastatic lesions in the liver and pancreas.

Abdomen↗
PubMed1977

Sarcoma of the kidney: angiographic features.

Sarcomas of the kidney are highly malignant neoplasms. Abnormal vascularity can be detected in almost all types of sarcomas, but arteriovenous shunting, pooling of contrast material, and tumor staining are seldom present. Extension to renal vein and inferior vena cava may occur. While angiographic findings in our seven cases of renal sarcomas were nonspecific, this diagnosis should be considered in a relatively hypovascular neoplasm especially when the capsular arteries contribute considerably to the vascular supply. Nevertheless, statistically the most likely diagnosis of a hypovascular mass is renal cell carcinoma. Angiographic studies do not alter the management of the patient but merely suggest the diagnostic possibility of sarcoma. Angiographic diagnosis of different histologic types of sarcomas is not possible.

Adult↗
PubMed1977

Angiographic observations on chemodectomas of the head and neck.

Angiographic experience with chemodectomas in 21 patients is reviewed. Arterial supply was identified from the vertebral artery, the internal carotid artery, and branches of the external carotid artery. A striated cephalad extension from a cervical chemodectoma (five patients) is believed to represent arterial supply to tumor in vein. In two patients, internal and external carotid arteriograms did not opacify important arteries originating near the carotid bifurcation. Retrograde filling of sigmoid sinus (four patients), tumor mass in jugular vein (two patients), and arteriovenous shunting (nine patients) were observed during the venous phase. Thorough angiogra phy is essential for evaluation of chemodectomas of the head and neck.

Angiography↗
PubMed1977

Laryngeal tuberculosis.

Laryngeal lesions observed in patients with pulmonary tuberculosis are most likely tuberculous. Although tuberculosis and carcinoma may be indistinguishable clinically and radiographically, specific radiographic studies better delineate the lesion and may suggest its true etiology. Five cases of laryngeal tuberculosis referred to M.D. Anderson Hospital and Tumor Institute as carcinoma of the larynx are described and illustrated. In the acute exudative type, inflammatory disease was suspected, but in the chronic localized lesion, carcinoma was the primary consideration. The histologic diagnosis was established by biopsy.

Adolescent↗
PubMed1977

Transcatheter intravascular coil occlusion of experimental arteriovenous fistulas.

Fistulas were surgically created between the carotid artery and jugular vein in dogs. They were successfully occluded by means of transcatheter placement of stainless steel coils with attached woolen strands. Angiographic studies performed prior to, immediately after, and 4 weeks after occlusion were used to evaluate the efficacy of the procedure. Specimens excised 4 weeks after occlusion revealed fibrotic encasement of the coil in the fistula, forming a permanent occlusion. The technique has clinical application, and suggestions concerning its clinical use are presented based on information gained from the animal study.

Animals↗