Biomedical subjects
Publications and source records attributed to S R Baker.
Thyroid abscess is a rare disorder, particularly since the advent of antibiotic agents. A case of thyroid abscess, which developed without systemic disturbance, and presented as a pulsatile mass in the neck, is reported. Excision with primary closure was followed by uncomplicated recovery, and is suggested as the preferred form of management.
Malignant salivary gland neoplasms in children are rare. Such tumors usually occur in the parotid gland of older children. Sixteen cases of major salivary gland malignancy are reviewed, 14 occurring in the parotid gland and two in the submandibular gland. Adenoid cystic carcinoma was the most common malignancy encountered, occurring in five patients; four have died of disease. Low-grade mucoepidermoid carcinoma occurred in three patients and all remain alive and free of disease. An assorted variety of other cancers occurred in eight patients. One child died of reticulum cell sarcoma of the parotid gland, and two children have died of adenocarcinoma. The remaining five patients remain alive and free of disease. Salivary gland malignancies in children appear to have similar biological activity as those occurring in adults. Such tumors must be treated according to the same principles generally accepted for management of salivary gland malignancies in adults.
The oblique forehead flap provides sufficient tissue for total reconstruction on the nasal tip and columella. In the majority of cases, the secondary defect of the forehead can be closed primarily. Thus, the oblique forehead flap often obviates the need for a scalping flap, which is a surgical procedure of greater magnitude and results in more significant secondary deformity of the skin of the forehead.
The false-negative rate of barium enema examinations for the recognition of polypoid sigmoid cancer was evaluated in 167 patients with histologically proven carcinoma. The cases were classified according to the coexistence of sigmoid diverticula. In patients with less than 15 diverticula, 3.1% of lesions were missed, while in those with more than 15 diverticula, 20.4% of tumors were undetected. The overall error rate was 7.2%. Extensive diverticulosis is an important factor limiting the sensitivity of barium enema examinations for the evaluation of sigmoid masses.
Two cases of giant vascular malformation of the kidney demonstrated by computed tomography and angiography are presented. The vascular malformations form completely outside the kidney. They arise from the renal parenchyma, simulating renal cyst, and present as a renal pelvic mass causing hydronephrosis. The finding of a renal mass with a markedly and uniformly contrast enhancement demonstrated by computed tomography should suggest the possibility of a vascular malformation.
The effectiveness of intra-arterial chemotherapy is dependent on a high tumour to normal blood flow ratio (T/NT). This report demonstrates the use of a vasoconstrictor (NE) to improve the relative blood flow to head and neck tumours by causing vasoconstriction and decreased blood flow to normal soft tissue. Five quantitative planar Tc-MAA perfusion studies were performed on three patients with increasing dose rates of norepinephrine (NE) to determine the optimal dose in each patient that would produce the best T/NT. All patients demonstrated a change in perfusion pattern with increasing dose rates (0.1 to 15 micrograms min-1), although there was considerable variation between patients. Quantitative SPECT was performed on two patients. In one, there was a 35% increase in the T/NT and a 16% decrease in arteriovenous (A-V) shunting to the lung.
A prospective study was performed to determine the effect of restrictive criteria on the use of emergency skull radiography and computed tomography (CT) of the head. Emergency skull radiography required the completion of a special requisition form. Emergency CT of the head was done at the request of senior consultants and was available on a full-time basis. Over 1 year, 2,758 skull studies were performed, a decrease of 39.1% when compared with the year before restrictive criteria were instituted, during which 4,587 skull examinations were done. In the same period, the number of emergency CT scans of the head increased by 45.7%, from 471 in the control year to 686 in the experimental year. With the use of restrictive criteria, a net savings of +164,000 was achieved. Our results suggest that the use of restrictive criteria is a cost-effective means of limiting skull radiography when CT of the head is readily available.
We have evaluated the use of the completely implantable infusaid pump in 22 patients with advanced cancer confined to the head and neck. Unilateral head lesions are treated with a single-catheter pump infusing the external carotid artery. A dual-catheter pump is used for midline or bilateral head lesions (both external carotid arteries infused) or unilateral head and neck disease (the second catheter positioned in the thyrocervical trunk). The infused volume of each catheter is determined by nuclear tomography after slow intra-arterial injection of 99mTc-labeled macroaggregated albumin through the pump's auxiliary port. The injection port/infusion chamber configuration of the pump permits long-term, multiple-course, combination-drug intra-arterial therapy on an outpatient basis. To date, 15 patients have been treated longer than 6 months and five longer than 1 year with no bleeding or neurologic complications. Eight of 10 patients treated with cisplatin and fluorodeoxyuridine (FUdR) have responded. The Infusaid pump permits long-term, practical, cost-effective, intra-arterial therapy to the entire tumor volume of ambulatory head and neck cancer patients with a high rate of tumor response.
In recent years, the successful grafting of human tumors into immune deprived animals has spurred the hopes of developing a reliable in vivo model for evaluation of human cancer. The nude mouse has created new perspectives in many different areas of cancer research, and has proved to be the most useful recipient of any animal system for tumor heterotransplantation. This study determined which of several squamous cell carcinoma (SCC) cell lines would reproducibly grow as heterotransplants in nude mice, and allowed an opportunity to determine whether characteristics of the tumor changed as a result of propagation in tissue culture. Sixteen (76%) of the 21 SCC lines heterotransplanted in nude mice remained as viable tumor nodules. Nine (43%) of these lines reproducibly produced progressively enlarging tumor masses. Five (24%) SCC lines failed to grow as heterotransplants. The average lag phase between implantation and the beginning of growth for all SCC lines tested was approximately 7 weeks and emphasizes the need for prolonged observation of nude mice following SCC heterotransplantation. The rate and pattern of growth of SCC in nude mice appears to be related specifically to the tumorigenic factors of a given cell line. The concurrent presence of other SCC or non-SCC tumors in a given mouse do not appear to influence the growth of a specific cell line. In addition, specific host factors that might vary from one mouse to another did not alter the growth patterns of SCC. Histological examination of the SCC lines successfully heterotransplanted in nude mice showed similar histological appearances to the original tumor in the human host.
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The high tumor response rates associated with intensive chemotherapy in previously untreated patients with advanced head and neck squamous cell carcinoma (HNSCC) led to the initiation of a multi-institutional National Cancer Institute trial. This trial used preoperative chemotherapy in patients with resectable Stage III and IV squamous cell carcinoma of the oral cavity or larynx/hypopharynx. Response rates, toxicity, and a variety of patient and tumor characteristics were analyzed to determine which factors might be useful in predicting tumor response to preoperative chemotherapy. Two hundred eighty-two patients received one course of preoperative cisplatin and bleomycin chemotherapy and were evaluable. There were 22 complete responses (CR) and 114 partial responses (PR) at the primary site (48% response rate). Of 197 patients with clinically positive regional adenopathy, 29 CRs and 73 PRs were observed (52%). Toxicity associated with the chemotherapy regimen was minimal. Primary tumor and regional node responses to chemotherapy were strongly correlated. No significant differences were found in primary or nodal response rates with respect to differing tumor site, stage, histologic differentiation, patient performance status, nutritional status, leukocyte count, hemoglobin level, age, sex, or alcohol use. Primary tumor response, however, was significantly related to T classification (P = 0.048). Nodal response was strongly associated with N classification and nodal size (P = 0.02 and P = 0.075, respectively). These findings suggest that, of the patient and tumor characteristics analyzed, none were more useful in predicting tumor response than clinical tumor staging parameters.
Chemotherapy delivered through angiographically placed catheters requires patient hospitalization, and is usually limited to short-term infusions. Treatment given through surgically placed catheters with external portable infusion pumps permits greater patient freedom and longer infusion durations. However, some patient restrictions remain, and thrombotic or infectious complications are common with long-term therapy. A totally implantable pump has allowed long-term intraarterial therapy in an outpatient population. Patient activity was unrestricted, and the complication rate has been low. This system has been used to deliver single-agent therapy with FUdR, dichloromethotrexate or bleomycin, and combination-drug treatment with cisplatin + FUdR or bleomycin + mitomycin C + dichloromethotrexate. The majority of patients have responded to at least one drug program. Seven of 14 patients who had pumps implanted over 1 year ago have received therapy for at least 1 year, and four patients have had functioning system for over 2 years. Systemic toxicity (except for nausea and vomiting with cisplatin) has been uncommon. Further clinical experience with these programs will be necessary to fully establish the objective response rate. However, the Infusaid Pump has proven safe, reliable and has high patient acceptance.
Prior studies of impaired cellular immune reactivity in patients with head and neck squamous carcinoma (HNSC) suggest that immune deficiency associated with tumor growth may be related, in part, to alterations in immunoregulatory functions. To determine if production of soluble mediators of the immune response (lymphokines) is impaired in patients with HNSC, leukocyte migration inhibition in response to phytohemagglutinin was assessed in 32 patients with HNSC and 29 normal subjects and was correlated with levels of specific peripheral blood lymphocyte subpopulations to determine if quantitative levels of immunoregulatory lymphocyte subpopulations were related to in vitro lymphokine production. In the patients with cancer, leukocyte inhibitory factor production was consistently and significantly impaired and was directly related to levels of T4-positive (helper/inducer) lymphocytes. Substantial differences in levels of individual subpopulations were not detected among normal subjects and patients with cancer; however, the mean T4/T8 ratio was substantially increased in the patients with cancer. The findings confirm and extend prior observations of impaired cellular immune mechanisms in patients with HNSC and suggest that impaired lymphokine production may be related to quantitative and qualitative alterations in lymphocyte subpopulations.
Periosteal osteosarcoma, a variant of juxtacortical osteosarcoma, is seldom seen in the jaws. The clinical, radiographic, and histopathologic features of a rare mandibular periosteal osteosarcoma presenting as a deep mass in the area of the parotid are reported. The clinicopathologic features that distinguish this lesion from the more common parosteal osteosarcoma are also discussed.
We present the results of a questionnaire sent in the autumn of 1981 to all board certified specialists practicing radiology, pathology and anesthesiology who are graduates of Indian medical schools and now reside in the United States. Respondents were asked to indicate their Indian state of birth, the size of the community in which they were born. The location of their medical school, the size of the city in which they now reside and their reasons for emigrating to the United States. The respondents tended to settle in the larger cities of the Northeast and Midwest, filling, to some degree, positions provided by the movement of American trained physicians to the West and South. Most came from urban areas and from the more urbanized Indian states. Rajasthan, Madhya Pradesh and the East Indian states were underrepresented. The limited opportunities for specialty practice at home and the perception of an unmet physician demand in the United States were the twomost important reasons for emigration. Job availability largely determined locational choice in the United States. The distribution of emigrants arriving from 1965 to 1975 were similar to that of a much smaller group of early emigrants. Restrictions on entry of foreign born, foreign trained physicians as prescribed by the Health Professionals Assistance Act of 1976 (Public Law 94-284) mandates that the cohort of young specialists will not be supplemented to a significant extent by future arrivals from the Indian sub-continent. This will create an encapsulated minority of highly trained Asian-Americans. As they grow older their locational choices and integration into American society bears watching.
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The therapeutic advantage of intraarterial infusion chemotherapy depends upon delivery of a high drug concentration to the entire tumor bulk with maximum sparing of critical normal tissues. It is clear that successful application of regional therapy must include methodology to assess quantitatively and qualitatively the infused area. 99mTc macroaggregated albumin (Tc-MAA) injected intraarterially is held on first pass in the arteriolar capillary bed, thus providing a map of blood flow distribution. Analog and digital planar images and single photon emission computed tomography (SPECT) after Tc-MAA injections provide static and transaxial tomographic images of head and neck intraarterial infusions. SPECT can be viewed as an endless movie-type display, thus producing a "rotating cimematic display." These radionuclide localization techniques provide a three-dimensional delineation of the tissues infused, including subsurface details not appreciated with dye injection alone. These procedures should be considered an integral part of intraarterial therapy of head and neck cancer.
Calcification in the portal vein is a rare radiologic finding, occurring almost always in patients with portal hypertension. Calcium may be deposited in a thrombus or, as in this patient, in the vein wall. The characteristic position, location, and pattern of portal vein wall calcification permit its diagnosis from radiographs of the abdomen.