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G B Thompson

Publications and source records attributed to G B Thompson.

At least 73 records · Page 4Linked to original sources
PubMed1995

An immunohistochemical survey for neuroendocrine cells in regional pancreatic lymph nodes: a plausible explanation for primary nodal gastrinomas? Mayo Clinic Pancreatic Surgery Group.

BACKGROUND: The existence of primary gastrinomas in lymph nodes continues to be controversial, because distinction from metastases from occult or regressed primary tumors may be difficult to exclude with certainty. If primary nodal gastrinomas do indeed occur, precursor neuroendocrine cells should be identifiable within lymph nodes. In a effort to detect these cells we undertook an immunohistochemical survey of regional pancreatic lymph nodes by using antibody against chromogranin, a highly specific marker for mature neuroendocrine cells. METHODS: We retrospectively identified consecutive cases from five surgeons in which Whipple resections had been performed for nonendocrine pathologic conditions. All formalin-fixed, paraffin-embedded lymph nodes were identified from these 106 cases, excluding lymph nodes with metastases. Immunoperoxidase staining with monoclonal antibody against chromogranin A was performed on single tissue sections. All slides were reviewed by a single pathologist; chromogranin-positive cells were identified and, when possible, further evaluated immunohistochemically with additional neuroendocrine markers, including sequential synaptophysin staining. RESULTS: A total of 1026 lymph nodes were available for review. Although well-formed intranodal chromogranin-positive nests were not identified, six nodes from three patients contained 13 strongly chromogranin-positive cells representing putative neuroendocrine cells. Mast cells showed weak nonspecific staining with chromogranin but were morphologically distinct. Perinodal adipose tissue contained a single paraganglion and several small neuroendocrine clusters. CONCLUSIONS: Putative neuroendocrine cells are rarely (less than 1%) found in regional pancreatic lymph nodes. Although these may be embryonic rests and might represent precursors of primary nodal gastrinomas, specific hormones have yet to be identified in these cells. Although these data provide support for the concept of primary nodal gastrinomas, this remains a diagnosis of exclusion.

Adult↗
PubMed1995

The functions of phonology in the acquisition of reading: lexical and sentence processing.

It has been claimed (V. Coltheart, Laxon, Rickard, & Elton, 1988) that learners as well as skilled readers use phonology for multiple functions in reading-for-meaning tasks. This claim was examined using lexical decision and sentence evaluation tasks. It was found in the first experiment that the type of instruction learners had received determined whether there was prelexical use of phonology in responding to items out of sentence context. Type of instruction had no effect when the items were in context. In the second experiment, performances on a homophone sentence evaluation task and a homophone semantic decision task, which excluded sentence processing, were examined. The results suggest that phonology served the function of access to lexical meanings in addition to any function in postlexical sentence processing. The obtained relationships between relative frequencies of the presented and unpresented homophone mates and item accuracy on these tasks were inconsistent with exclusive use of "direct access" but consistent with access of lexical meaning via phonology and application of a "spelling-check" procedure when multiple homophonic meanings are activated.

Attention↗
PubMed1995

General surgical laparoscopic procedures for the "nonlaparologist".

OBJECTIVE: To assess our initial experience with a variety of laparoscopic procedures that can be performed by general surgeons with the basic skills used for laparoscopic cholecystectomy and without advanced laparoscopic expertise. MATERIAL AND METHODS: We retrospectively reviewed a 36-month experience (1991 through 1994) at our institution with a consecutive series of patients who underwent basic laparoscopic surgical procedures but specifically excluding cholecystectomy, appendectomy, herniorrhaphy, and colectomy. RESULTS: Procedures performed laparoscopically included gastrostomy, jejunostomy, small bowel resection, intra-abdominal and retroperitoneal biopsy, staging of intra-abdominal malignant lesions, and adhesiolysis for relief of small bowel obstruction. During the 3-year study period, 106 patients underwent 107 procedures, 89 of which were successful. Four patients had substantial complications, two of whom underwent surgical repair. CONCLUSION: A spectrum of procedures may be safely performed with the skills learned from laparoscopic cholecystectomy and without the need for advanced laparoscopic skills such as intracorporeal suturing or tying of knots.

Biopsy↗
PubMed1994

Paraneoplastic cholestasis and hypercoagulability associated with medullary thyroid carcinoma. Resolution with tumor debulking.

The authors report a 69-year-old woman with a hypercoagulable state manifesting as superior sagittal sinus thrombosis, thrombocytosis, right lower extremity deep venous thrombosis, and subsequent pulmonary embolus. The liver enzyme values were elevated in a cholestatic pattern. Carcinoembryonic antigen level was markedly elevated. Evaluation revealed that her longstanding "goiter" had slowly enlarged during the past 6 years. The serum calcitonin level was markedly elevated. Subsequent biopsy revealed medullary thyroid carcinoma. Surgical debulking of the tumor and lymph nodes resulted in substantial reduction of the calcitonin and carcinoembryonic antigen levels in a matter of days. Long-term follow-up revealed normalization of cholestasis and resolution of the hypercoagulable state. Review of the literature revealed no previously reported cholestasis or hypercoagulable state associated with medullary thyroid carcinoma. The literature on paraneoplastic cholestasis, carcinoembryonic antigen production, and hypercoagulable states is reviewed.

Aged↗
PubMed1994

Extrapancreatic gastrinomas. Surgical experience.

OBJECTIVE: Although widely reported on, the clinical diversity and eventual varied outcome of patients with extrapancreatic gastrinomas remain a medical mystery. In an attempt to help clarify conflicting management of extrapancreatic gastrinomas, we reviewed our experience with these unique tumors. DESIGN: Retrospective analysis with long-term follow-up (mean, 8 years). SETTING: Tertiary care referral center. PATIENTS: From January 1958 through January 1993, we identified and operated on 23 patients with extrapancreatic gastrinomas (duodenum, n = 18; stomach, n = 3; nodal, n = 2). The 12 men and 11 women (none with multiple endocrine neoplasia type I syndrome) ranged in age from 12 to 68 years (mean, 47 years). Preoperatively, all patients were symptomatic with peptic ulcer disease (duodenal [n = 18, 78%], jejunal [n = 4, 17%]) and/or diarrhea (n = 17, 74%). INTERVENTION: Preoperatively, tumor localization was successful in only three patients (13%). Surgical management included tumor excision only in 14 patients (61%), partial gastroduodenectomy in six (27%), total gastrectomy in one (4%), limited enterectomy in one (4%), and tumor biopsy alone in one (4%). Seven patients had evidence of lymphatic metastases at the time of operation, including a single patient with hepatic metastases (malignancy rate, 30%). Postoperatively, complications developed in seven patients (30%): wound infection in two, ileus in two, pulmonary sepsis in one, intra-abdominal abscess in one, and diabetic ketoacidosis in one. The postoperative mortality rate was 4%. MAIN OUTCOME MEASURE: Emphasis was placed on rendering patients eugastrinemic. RESULTS: Long-term follow-up (mean, 8 years) of all patients revealed that 11 patients (48%) were eugastrinemic, asymptomatic, and not receiving gastric acid-reducing medication. Sixteen patients remain alive and well. Of the six now decreased patients who had been participating in long-term follow-up (mean survival, 14 years), death was due to atherosclerotic coronary artery disease in four and tumor progression in two. CONCLUSION: Following surgical excision, patients with extrapancreatic gastrinomas have a favorable outcome, with nearly half being cured.

Adolescent↗
PubMed1994

Recovery rate and plasma zinc and copper concentrations of steer calves fed organic and inorganic zinc and manganese sources with or without injectable copper and challenged with infectious bovine rhinotracheitis virus.

Two experiments were conducted using feeder calves in a randomized block design to determine the effects of organic and inorganic sources of Zn and Mn fed pre- and posttransit (Exp. 1 and 2) with or without injectable Cu (Exp. 2) on DMI, rectal temperature, BW changes, and plasma Zn and Cu concentrations of feedlot steers challenged with infectious bovine rhinotracheitis virus (IBRV). In Exp. 1, before weaning, all steers and their dams received the following free-choice mineral supplements: 1) control (no supplemental Zn or Mn), 2) ZnO+MnO (ZnMnO), and 3) Zn methionine+Mn methionine (ZnMnMet). In Exp. 2, 18 d before weaning and shipping, steers were allotted into two groups (22 steers/group) and fed 225 mg of Zn.steer-1 x d-1 in .9 kg of ground corn as ZnO or ZnMet. Half of the steers from each group were injected (s.c.) with 120 mg of Cu from Cu glycinate. Steers (Exp. 1 and 2) were weaned and shipped approximately 2,500 km to the feedlot, where they received the same supplements in the form of a complete diet for 34 d, during which time calves recovered from the stress due to shipment. All steers were initially sero-negative to IBRV. On d 34 (d 0 of IBRV), all steers were challenged with IBRV and DMI, rectal temperature, and BW change were monitored for 28 d.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1994

Parathyroid imaging with technetium-99m-sestamibi: an initial institutional experience.

BACKGROUND: The ideal method for preoperative localization of abnormal parathyroid glands has yet to be determined. Technetium-99m-sestamibi, previously used for myocardial perfusion studies, has recently been introduced for parathyroid imaging. METHODS: From August 1991 to September 1993, 44 patients underwent Tc-99m-sestamibi scanning (45 scans) and surgical exploration for hyperparathyroidism at our institution. These 44 patients form the database for this retrospective study. Twenty-eight patients had persistent hyperparathyroidism, six had recurrent disease, three had prior thyroid operation, and seven underwent first time neck operations. The nature of disease was complex and varied: single gland, 26; primary hyperplasia, 5; multiple endocrine neoplasia type 1, 5; familial, 3; secondary or tertiary, 5. One patient with single gland disease and one patient with multiple endocrine neoplasia type 1 had parathyroid carcinoma. All patients had biochemical confirmation of hyperparathyroidism. RESULTS: Twenty-six (58%) of 45 scans accurately predicted the location(s) of all abnormal gland(s) involved (true positive). Surgical removal of these glands was curative. Sixteen (36%) of 45 scans were false negative because they did not show all abnormal glands involved; however, 7 of these 16 scans did localize at least one abnormal gland. The overall sensitivity of this test was 62% when all abnormal glands were considered but increased to 79% with the demonstration of at least one abnormal gland. These values increased to 80% and 90% (p = 0.03), respectively, in the last 20 patients when the injected dose of Tc-99m-sestamibi was increased from 10 to 15 mCi. Thirty-seven of 44 patients were cured after operation. Six of the seven patients who experienced surgical failure had multigland disease, one of which was malignant. Sestamibi scans correctly identified abnormal cervical glands in 18 (58%) of 31 patients and abnormal mediastinal glands in six (75%) of eight patients. CONCLUSIONS: Tc-99m-sestamibi scanning is helpful in the reoperative setting as an adjunct to localizing abnormal parathyroid tissue. A higher percentage of positive tests occurs in patients with mediastinal and single gland disease. A higher dose of Tc-99m-sestamibi (15 mCi) significantly improves test sensitivity.

Adult↗
PubMed1993

Reoperative insulinomas, 1927 to 1992: an institutional experience.

BACKGROUND: Between 1927 and 1992, 313 patients have undergone surgery for insulinoma(s) at our institution, 12% of which were reoperations. We retrospectively reviewed all cases (n = 39) of reoperative surgery for persistent hyperinsulinism to identify changing patterns in surgical approach, morbidity, and outcome and to evaluate the influence of preoperative and intraoperative localization studies. METHODS: The diagnosis of endogenous hyperinsulinism has evolved from satisfying Whipple's triad to documenting concomitant hypoglycemia and endogenous hyperinsulinemia. Thirty-nine patients were divided into two groups for comparison: those treated before localization studies were available (1927 to 1967) (n = 17) and those treated since that time (n = 22). Initial operations were also compared with reoperations among these 39 patients. RESULTS: There were 26 women and 13 men (mean age, 42 years). There was at least one positive preoperative localization study in 16 of 22 patients (73%). Intraoperative ultrasonogram and careful palpation successfully identified 10 of 11 tumors in the reoperative setting. Blind or completion pancreatectomies were common before 1967 (10 of 17 patients). Since 1967, 14 of 22 patients have undergone enucleation of their primary tumor. Operative morbidity increased from 21% to 58% with reoperation but decreased from 65% to 29% (p = 0.026) when comparing the preangiography to the postangiography eras. The development of iatrogenic diabetes mellitus occurred in 13 patients (33%) after reoperation. Forty-one percent had diabetes before 1967 and 27% since that time (p = not significant). Thirty-four of 36 patients (94%) without malignant tumors were cured by reoperation. There was one operative death. Survival for patients who underwent completion or total pancreatectomy was significantly reduced (p = 0.003). CONCLUSIONS: Reoperations for persistent hyperinsulinism can be highly successful in experienced hands. These reoperations, however, are associated with increased morbidity and iatrogenic diabetes. With experience and the use of selected localization studies, first-time failures can be avoided in most cases thus reducing the need for reoperations and its inherent sequelae.

Adolescent↗
PubMed1992

A study of metastatic cancer found during inguinal hernia repair.

Among 22,816 inguinal hernia repairs done between 1950 and 1988, 15 patients (0.07%) had metastatic tumors found within their hernias. Inguinal herniation was the initial sign of cancer in six patients. A palpable inguinal mass (53%) and abdominal or groin pain (67%) were the most common presenting sign and symptom, respectively. Primary tumor sites included the gastrointestinal tract (40%), ovary (20%), prostate (13%), mesothelium (13%), and unknown sites (13%). The median patient survival was 20 months and depended on the primary tumor site. Grossly apparent inguinal hernia sac abnormalities should be examined microscopically to avoid missing the diagnosis of metastatic cancer, but routine histologic examination of all hernia sacs is not warranted.

Abdominal Neoplasms↗
PubMed1991

Signal transduction via CD4, CD8, and CD28 in mature and immature thymocytes. Implications for thymic selection.

The positive and negative selection of immature thymocytes that shapes the mature T cell repertoire appears to occur at an intermediate stage of development when the cells express low levels of TCR/CD3. These cells are also CD4+CD8+ and CD28+ (dull), and signals delivered by these three accessory molecules have been implicated in the selection process. We have examined the regulatory function of these accessory molecules on responses of immature thymocytes stimulated through the TCR/CD3 complex. Cross-linking CD4 or CD8 with CD3 strongly enhanced signal transduction via CD3 as assessed by protein tyrosine phosphorylation and calcium mobilization. Subsequent cell proliferation could be induced by soluble anti-CD28 mAb, which was comitogenic for cells stimulated with CD3 x CD4 or CD3 x CD8 cross-linking, but was without effect on cells stimulated with CD3 x CD3 cross-linking. A potential role for CD28 signal transduction in thymic maturation is suggested by the demonstration that the BB-1 molecule, a natural ligand for CD28, is expressed on thymic stromal cells. Taken together, our data suggest a model of thymic development in which CD4 or CD8 may enhance TCR/CD3 signaling upon coligation by an MHC molecule. If the CD28 surface receptor is simultaneously stimulated by a BB-1 expressing stromal cell, this set of interactions could lead to proliferation and positive selection. In the absence of CD28 stimulation the enhanced TCR/CD3 signals might lead to apoptosis and negative selection.

Antibodies, Monoclonal↗
PubMed1991

Intellectual loss in Alzheimer's dementia and WAIS-R intrasubtest scatter.

Patterns of intrasubtest scatter in the WAIS-R protocols of patients (n = 32) with Alzheimer's disease were compared to those of normal elderly controls (n = 32). The Alzheimer's patients showed more randomly dispersed item failures on some subtests, but normal controls showed more intrasubtest variability on other measures. Rates of correct diagnostic classification based on scatter measures were only slightly better than chance despite the presence of prominent anomia, memory impairment, construction apraxia, and significant decline from premorbid intellectual level in demented patients. In contrast, demographically based estimates of intellectual loss produced accurate diagnostic classification in 81% of the cases. The incremental validity of qualitative scatter analysis in the evaluation of suspected Alzheimer's disease appears to be minimal.

Aged↗
PubMed1991

Feed intake, rectal temperature, and serum mineral concentrations of feedlot cattle fed zinc oxide or zinc methionine and challenged with infectious bovine rhinotracheitis virus.

Three experiments were conducted using feedlot steers in a randomized block design to determine the effect of zinc methionine (ZnMet) and zinc oxide (Exp. 3) on feed intake (DMI), rectal temperature, and serum mineral concentrations of feedlot cattle challenged with infectious bovine rhinotracheitis virus (IBRV). All the steers used were seronegative to IBRV. Steers were adapted for 7 d to their respective diets and challenged with 3.7 x 10(5) plaque forming units of IRBV on d 0 of each experiment. Live BW, rectal temperature, and individual daily DMI were recorded for 14 d. Blood samples were taken on d 0, 7, and 14. In Exp. 1, daily DMI of the control steers (Zn = 31 ppm) decreased 50% compared with 15% in the ZnMet (Zn = 90 ppm) steers 3 d after IBRV challenge. By d 6, the ZnMet steers had regained their pretrial mean daily DMI, but the control steers took 11 d. The ZnMet steers had lower (P less than .05) mean rectal temperature than the control steers on d 7 and 12. In Exp. 2, the control (Zn = 35 ppm) steers had lower (P less than .05) daily DMI on d 8 to 12 than the ZnMet (Zn = 89 ppm) steers. In Exp. 3, the mean decrease in daily DMI tended to be more rapid in the ZnO steers than in the control and ZnMet steers. All steers had the lowest daily DMI on d 5 and 6, coinciding with the highest rectal temperature. Serum Zn, P, and Mg concentrations decreased and serum Cu increased in all steers after infection. These data suggest that dietary Zn enhanced the recovery rate of IBRV-stressed cattle.

Animals↗
PubMed1991

Differences in rates of cancer screening by usual source of medical care. Data from the 1987 National Health Interview Survey.

Data from the Cancer Control Supplement of the 1987 Health Interview Survey (NHIS), a nationally representative sample of the United States population, was used to examine rates of six screening tests for cancer. The rates of screening were compared for people who receive their usual source of medical care in an HMO or prepaid group practice versus those who receive it in the fee-for-service sector. The purpose of this article is to determine whether HMOs remain more likely to offer cancer screening examinations than the fee-for-service sector. Results indicate that for five of six screening tests examined (Pap smear, mammography, breast physical examination, digital rectal examination, and blood stool test), members of HMOs are significantly more likely to have received the test within the last 3-year period. These results hold in a multivariate analysis when many factors correlated with selection into HMOs, health status, and use of medical services are controlled for, although results are only generalizable to whites. Future research should focus on why the rates for five of the six cancer screening tests examined are higher in HMO settings, and how we can use the HMO experience to improve consensus as to the usefulness of the tests in the non-HMO physician pool, and ultimately increase rates of screening tests in the non-HMO population.

Adolescent↗
PubMed1990

The knowledge and use of screening tests for colorectal and prostate cancer: data from the 1987 National Health Interview Survey.

Data based on the 1987 National Health Interview Survey are presented depicting factors associated with the knowledge and use of three tests for the early detection of colorectal and prostate cancer: digital rectal examination, fecal occult blood tests, and flexible sigmoidoscopy. The percentage of the at risk adult population who have ever heard of or had these tests is reported. The association of demographic, personal resource, and health system factors with knowledge of these tests is explored using multivariate logistic regression. Health system factors are most consistently associated with use of the tests and with knowledge. Family income, family size, education, knowledge of cancer early warning signs, and measures of encounters with the health care system are associated both with knowledge of and, independent of knowledge, with use of the tests. Residency in the non-South, being white or female, and having an optimistic attitude about cancer prevention are all factors associated with greater knowledge of the tests, but not greater use among those aware of the tests. Membership in a health maintenance organization is more strongly associated with knowledge and use of fecal occult blood tests than the other tests. No association was found between current smoking status and knowledge of or use of any of the tests.

Adult↗
PubMed1990

Pion therapy at TRIUMF. Treatment results for astrocytoma grades 3 and 4: a pilot study.

At TRIUMF, (located on the University of B.C. Campus), 53 patients with supratentorial astrocytoma grades 3 and 4 were treated with pions between 1982 and 1985. A 3-dimensional spot-scanning treatment technique has proven to be practical. The accuracy of the beam alignment system used for treatment was reproducible daily within 2 mm. Low pion flux has hindered optimal beam shaping but this will soon be remedied as flux improves. The overall median survival observed (53 patients) is 262 days from date of first radiation treatment. Younger (less than 49 years) patients have significantly better survival than older (greater than 50 years) patients (p = 0.001). From a base line dose of 40 Gy photons whole brain and 17.5 Gy pion boost, doses were escalated to 33 Gy pions localised to the primary tumour and the median survival improved from 198 to 436 days. Survival curves for patients treated with localised pion techniques to doses above 30 Gy are significantly better than for those treated with schedules of pions mixed with photons (p = 0.04). It appears that optimal pion dose for brain tumours is 33 Gy minimum with a possible maximum of 36 Gy and doses delivered in 15 fractions in 3 weeks. Requirements for future trials are discussed.

Adult↗