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Biomedical subjects

T L Kennedy

Publications and source records attributed to T L Kennedy.

At least 37 records · Page 2Linked to original sources

Complement kinetics during continuous arteriovenous hemofiltration: studies with a new polysulfone hemofilter.

Biocompatibility of the Renaflo polysulfone hemofilter was assessed during treatments with continuous arteriovenous hemofiltration. Pre- versus postfilter levels of C3a, C4a, C5a and leukocyte counts were measured prior to and 15, 60 and 90 min after placement of the Renaflo. Results revealed a small, and previously unrecognized, increase in postfilter C3a (1,224 +/- 56 vs. 1,535 +/- 150 ng/ml, mean +/- SEM, n = 15; p less than 0.01). A comparable increase was also found during treatment with an Amicon polysulfone filter. There were no other significant changes in any parameter studied and no patient exhibited symptoms related to complement activation. We conclude that the Renaflo filter is safe for use during continuous arteriovenous hemofiltration. Although clinically insignificant, there is a detectable activation of C3 by polysulfone membranes.

Aged↗

Primary small cell carcinoma of the larynx: analysis of treatment.

Primary small cell carcinoma of the larynx continues to pose problems in its treatment. Four patients with this neoplasm were seen in a seven-year period at our institution and 49 patients were reviewed from the world literature. The only variables which significantly affected survival were the presence of metastases at initial examination and treatment modality. Those patients treated with chemotherapy and radiation therapy had an increased length of survival and increased chance of survival as compared to patients subjected to other treatment modalities. Because of the small number of patients reported in the world literature and lack of controlled studies, the treatment of small cell carcinoma of the larynx remains controversial; this retrospective analysis suggests that combination chemotherapy plus radiation offers the best chance for cure.

Aged↗

Neuroendocrine tumors. A European view.

A center in Belfast, Northern Ireland, has established a register for tumors of the gastroenteropancreatic endocrine system. Carcinoid tumors occur most frequently. Of the non-carcinoid tumors, insulinomas, gastrinomas, and unknown types have the highest incidence, with other types being extremely rare. The potentially remediable nature of the tumors is stressed, and frequently a good quality of life can be experienced even in the presence of metastatic disease. The syndromes are probably underdiagnosed as they present with clinical features for which there are more common explanations, and appropriate diagnostic methods are therefore not used. The management of the syndromes is reviewed with particular emphasis on the treatment of patients with inoperable disease. Histamine (H2)-receptor antagonist therapy has made an impact in Zollinger-Ellison syndrome, and streptozotocin and somatostatin analogues can control tumor growth and endocrine syndromes, respectively.

Apudoma↗

Indium-111 autologous leukocyte imaging in pancreatitis.

Thirty-nine patients with acute pancreatitis have been assessed using a prognostic factor grading system, abdominal ultrasound, and autologous leukocyte imaging. Both prognostic factor grading and leukocyte imaging can accurately assess the severity of the disease early in its course. All patients with a negative indium-labeled leukocyte image recovered without sequelae, whereas five of the 12 patients with a positive image developed complications, including two deaths. Abdominal ultrasound is of no value in assessing severity, but is a useful method of detecting those patients with gallstone-associated disease. In patients with suspected abscess formation following acute pancreatitis, indium leukocyte imaging does not differentiate between fat necrosis and abscess formation. In this situation, computerized tomography should be carried out before laparotomy is undertaken.

Abscess↗

Characterization of immunoreactive forms of pancreatic polypeptide in islet cell tumors using antisera with different regional specificities.

Tumor tissue from a heterogeneous group of patients with clinically and histologically diagnosed islet cell tumors has been assessed for pancreatic polypeptide (PP) content using radioimmunoassay. Immunoreactive forms of PP, obtained by gel filtration of tissue extracts, were detected using antisera with different regional specificities. Normal pancreatic tissue contained one form of PP coeluting with human PP whereas, tumor tissue from patients with insulinoma, Zollinger-Ellison, and WDHA (watery diarrhea hypokalemic achlorhydric) syndromes contained, in addition, higher molecular weight forms of immunoreactive PP. Furthermore, a lower molecular weight form was detected in tumor tissue from a Zollinger-Ellison syndrome patient. The high molecular weight forms of immunoreactive PP were not recognized using a C-terminal-specific antiserum, whereas the smaller form was only detected using this antiserum. The variation in cross-reactivity observed with two antisera in this study emphasizes the limitations of using a single antiserum to detect molecular forms of peptide hormones, particularly those in islet cell tumors.

Adenoma, Islet Cell↗

Macrophage chemotaxis in anti-tubular basement membrane-induced interstitial nephritis in guinea pigs.

Interstitial renal lesions containing T cells and macrophages develop after 14 days in guinea pigs immunized to produce anti-tubular basement membrane-induced interstitial nephritis. We serially examined the renal venous and systemic arterial sera from such animals to determine if chemotactic factors were released across their kidneys. Our findings demonstrated the presence of a macrophage-specific renal chemoattractant with peak detectability on Days 10-14, just subsequent to the deposition of alpha TBM-Ab, but prior to the development of significant renal injury. We propose that such factors may provide important communication signals in the immunopathogenesis of this form of interstitial injury.

Animals↗

Late mortality after vagotomy and drainage for duodenal ulcer.

Seven hundred and thirty five patients who underwent elective vagotomy and drainage procedures in one hospital during 1957-67 were followed up until 1 September 1982. At this time 281 were dead compared with an expected 184. This gives a ratio of observed to expected deaths of 1.53 (p less than 0.0001). The most important cause of increased mortality was lung cancer, which accounted for 33 of the excess deaths (observed to expected ratio 3.53). Gastric cancer yielded an observed to expected ratio of 3.3. Other causes of death that were significantly more common than expected were cerebrovascular accident, bronchopneumonia, and colorectal cancer. It is concluded that although gastric cancer occurs more commonly after vagotomy and drainage than in the general population, it is not as important a cause of death as diseases related to smoking.

Adolescent↗

A controlled trial of bipolar electrocoagulation in patients with upper gastrointestinal bleeding.

We have assessed the value of the BICAP electrocoagulation probe in reducing the incidence of further bleeding in patients with upper gastrointestinal haemorrhage. One hundred and twenty-nine patients were studied in a prospective randomized controlled trial. There were 85 male and 44 female patients, age range 16-92 years. Forty-five patients had stigmata of recent haemorrhage (visible vessel or spot) and were randomized during endoscopy to 24 control and 21 treatment patients. Seven control patients rebled compared with nine treated patients (Fisher's exact probability test P = 0.44). The transfusion requirements of control patients (3.9 +/- 3.2 units) was not different from that of treated patients (5.7 +/- 3.7 units): Mann Whitney U test, P = 0.06. In the treatment group there was no difference in the operation rate. Also, the number of probe applications between patients with further bleeding and those with no further bleeding was similar (11.6 +/- 5.5 and 11.0 +/- 5.75 respectively). Access with the probe was considered inadequate in 50 per cent of lesions, but this did not correlate with the incidence of rebleeding. Stigmata of recent haemorrhage were significant in predicting rebleeding (P = 0.0019 Fisher's exact probability test). Overall mortality rate of 3.2 per cent was low and was not influenced by electrocoagulation or presence of stigmata of recent haemorrhage. We have not shown that BICAP bipolar electrocoagulation reduces the incidence of rebleeding in upper gastrointestinal haemorrhage.

Adult↗

Meta-iodobenzylguanidine in metastatic phaeochromocytoma.

A case of metastatic phaeochromocytoma is presented. Meta-iodobenzylguanidine was used to locate the tumour but failed to show two functioning abdominal metastatic deposits. Although meta-iodobenzylguanidine appears to be highly specific for phaeochromocytoma, a negative scan does not exclude a functioning tumour with confidence.

3-Iodobenzylguanidine↗

Relationship between histology and gastric juice pH and nitrite in the stomach after operation for duodenal ulcer.

One hundred patients who had undergone operation for duodenal ulcer (68 vagotomy and gastroenterostomy; seven vagotomy and pyloroplasty; 22 gastrectomy and three gastroenterostomy) 10 or more years previously each underwent endoscopy. Biopsies were taken and gastric juice aspirated for measurement of pH and nitrite concentration. Patients were divided into five histological grades; chronic superficial gastritis (+/- minimal atrophic gastritis) (35), atrophic gastritis/intestinal metaplasia (30), mild dysplasia (21), moderate/severe dysplasia (13) and carcinoma (one). A wide spectrum of pH values was found with 35 patients having a fasting intragastric pH below 4.0 and 65 above 4.0. A strong relationship was found between histological grade and pH. Patients with chronic superficial gastritis had a fasting intragastric pH below 4.0 more frequently than those with moderate/severe dysplasia (p less than 0.001). Gastric juice nitrite concentrations were higher in the moderate/severe dysplasia group than in the chronic superficial gastritis group (p = 0.02). The strong correlation between pH and nitrite concentration, previously documented, was confirmed. The implications of these findings in the pathogenesis of carcinogenesis in the postoperative stomach are discussed.

Adult↗

Relation between intragastric bile acid concentration and mucosal abnormality in the stomach after vagotomy and gastroenterostomy for duodenal ulcer.

A high incidence of possible premalignant conditions of the gastric mucosa has been reported in the postoperative stomach and it has been suggested that bile plays a role in their pathogenesis. Fifty eight patients who had had a vagotomy and gastrojejunostomy between 1957 and 1967 underwent endoscopy and biopsy. Subsequently, samples of fasting and postprandial gastric juice were taken from all patients for analysis of total bile acid. The patients were divided into three histological groups: group 1 (24 patients) had gastritis or mucosal atrophy but no more than mild dysplasia; group 2 (23 patients) had intestinal metaplasia in one or more biopsies; group 3 (11 patients) had moderate or severe dysplasia in one or more biopsies. Group 2 and group 3 patients had higher fasting intragastric bile acid concentrations than group 1 (p less than 0.01 in both cases). There was no difference between fasting bile acid concentrations in groups 2 and 3. In the postprandial phase groups 2 and 3 also had higher peak intragastric concentrations than group 1 (p less than 0.01 in both cases). Again, there was no significant difference between groups 2 and 3. It is concluded that there is a relation between mucosal abnormality in the postoperative stomach and intragastric bile acid concentration. The possible aetiological link between bile acid and these mucosal abnormalities is discussed.

Adult↗

Relation between gastric histology and gastric juice pH and nitrite and N-nitroso compound concentrations in the stomach after surgery for duodenal ulcer.

Formation of N-nitroso compounds in gastric juice has been implicated in the pathogenesis of cancer in the stomach after operation. Gastric juice was aspirated from 85 subjects: 23 were controls, 51 had previously undergone vagotomy and gastrojejunostomy, and 11 had previously undergone vagotomy and pyloroplasty. The gastric juice samples were analysed for pH, nitrite, and total N-nitroso compounds. A significant correlation was found between pH and nitrite concentration (p less than 0.01). No significant correlation was found between pH and total N-nitroso compound concentration or between nitrite and N-nitroso compound concentration. The vagotomy and gastrojejunostomy patients had higher pH values and higher concentrations of nitrites and N-nitroso compounds than controls (p = 0.01 in all cases). The 51 vagotomy and gastrojejunostomy patients also underwent endoscopy and biopsy. They were divided into three groups: group 1 (21 patients) had no intestinal metaplasia and no more than mild dysplasia; group 2 (20 patients) had intestinal metaplasia; and group 3 (10 patients) had moderate or severe dysplasia. Groups 2 and 3 both had higher pH values and higher nitrite concentrations than group 1 (p = 0.01 in all cases). There was no significant difference, however, between either group 2 or 3 and group 1 for total N-nitroso compound concentration. Since there was no simple linear relation between pH and N-nitroso compound concentration, it was concluded that formation of N-nitroso compounds at high pH was unlikely to be involved in the pathogenesis of gastric cancer in the hypochlorhydric stomach after operation. The relation between nitrite and histological abnormality was not associated with a similar relation between N-nitroso compounds and histological abnormality. It therefore appears that there is no simple relation between N-nitroso compounds and the pathogenesis of premalignant gastric mucosal changes.

Duodenal Ulcer↗