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Biomedical subjects

G H Ballantyne

Publications and source records attributed to G H Ballantyne.

At least 19 recordsLinked to original sources
PubMed1992

Incidence and mortality of carcinoids of the colon. Data from the Connecticut Tumor Registry.

The aims of this study were to calculate the true incidence of colonic carcinoids in Connecticut from 1976 to 1986 and to determine the outcome of patients with these lesions. Fifty-four patients with carcinoids of the colon were identified (23 male and 31 female patients). Their average age was 64.1 +/- 2.1 years, with a range of 12 to 83 years. The age-adjusted incidence was 0.31 cases/100,000 population/year. Forty-eight percent of the carcinoids were located in the cecum; 16%, ascending colon; 6%, transverse colon; 11%, descending colon; 13%, sigmoid colon; and 6%, not assigned. Follow-up information was available in all cases. The crude 2-year survival rate was 63%, whereas the 5-year survival rate was 37%. Only one of six (16.6%) lesions that were 2 cm or smaller metastasized, whereas 23 of 31 lesions larger than 2 cm metastasized (74%). Six patients have survived an average of 43.5 months after local excision of their carcinoids. Fourteen patients died of their carcinoids. Metachronous gastrointestinal malignant neoplasms developed in six patients. These results suggest that, when found at an early stage, carcinoids of the colon (2 cm or smaller) can be treated by local excision. The vast majority of colonic carcinoids, however, are discovered at an advanced stage and should be treated aggressively with standard colonic resection. In addition, surveillance of the entire gastrointestinal tract should be initiated in these patients because of a high rate of other gastrointestinal malignant neoplasms.

Adolescent↗
PubMed1992

Ischemic colitis: patterns and prognosis.

We identified 47 patients with nonocclusive ischemia of the large intestine over a seven-year period. The mean age at presentation was 56.2 years, with a 2:2:1 male predominance. Associated medical illnesses were diabetes (17 percent), renal failure (5 percent), and hematologic disorders (5 percent). Six patients developed ischemic colitis after aortic surgery. The mean delay in diagnosis was 1.8 days (range, three hours to 23 days). The right colon was involved in 21 patients (46 percent). Overall, 15 of 16 patients were successfully treated nonoperatively with bowel rest and antibiotics; one patient who was managed nonoperatively died. Among the 31 requiring intestinal resection, enteric continuity was reestablished in 14. Second-look laparotomy in eight patients revealed further ischemia in two (20 percent). Mortality in the operative group was 29 percent (9 of 31). No patient has developed recurrent ischemia (mean follow-up, 5.3 years). Ischemic colitis often occurs without an obvious predisposing event, may involve all segments of the large intestine, and frequently requires surgery. While its course may be self-limited, elderly and diabetic patients, as well as those developing ischemia following aortic surgery or hypotension, continue to have a poor prognosis.

Age Factors↗
PubMed1992

Erythromycin stimulates ileal motility by activation of dihydropyridine-sensitive calcium channels.

Erythromycin, a macrolide antibiotic, is a potent stimulant of small bowel motor activity (MA) which may motility either via the peptide motilin receptor or neural mechanisms. We hypothesized that erythromycin stimulates directly stimulates smooth muscle cells by a calcium-mediated event. Thus, we evaluated the effect of neuronal blockade with tetrodotoxin, muscarinic blockade with atropine, and opiate blockade with naloxone on erythromycin-stimulated MA in isolated perfused segments of rabbit terminal ileum. We also tested the effect of nonspecific calcium channel blockade (verapamil and cadmiun) and specific blockade (dihydroxypyridine and nichol) on erythromycin-stimulated MA. MA was measured with a multichannel continuous perfusion manometry catheter. Erythromycin caused a concentration-dependent increase in MA (ED100 5 x 10(-4) M). Tetrodotoxin, atropine, and naloxone did not effect erythromycin-stimulated MA (P greater than 0.05). Both verapamil (10(-7) M) and cadmium (10(-2)-10(-4) M) inhibited erythromycin-stimulated MA. Selective blockade of "l" type calcium channels using dihydropyridine (10(-6) M) and "t" channels with nickel (10(-2)-10(-4) M) both reversed erythromycin-stimulated MA. Since the isolated segments of terminal ileum were free of exogenous humoral and neural effects, these studies indicated that erythromycin directly stimulated MA in the terminal ileum. Furthermore, since tetrodotoxin, atropine, and naloxone did not inhibit this increase in MA, erythromycin acted by a mechanism which was independent of the intrinsic nervous and opiate systems. In conclusion, these data are consistent with the model that erythromycin stimulates ileal motility by a mechanism involving activation of dihydroxypyridine and nickel-sensitive calcium channels.

Animals↗
PubMed1992

Laparoscopically assisted anterior resection for rectal prolapse.

We report for the first time the treatment of rectal prolapse by laparoscopically assisted anterior resection. A 52-year-old woman, institutionalized for the last 10 years after diffuse cerebral injury secondary to toxic shock syndrome, developed rectal prolapse. A long life span is anticipated for this otherwise healthy middle-aged woman. Anterior resection was selected as treatment because of the low, long-term rates of recurrence of rectal prolapse. Approximately 2 1/2 ft of sigmoid colon and proximal rectum were resected. The anastomosis was constructed using a double-stapling technique. After surgery, the patient experienced virtually no pain and received only a single injection of pain medicine in the postoperative period. She was started on clear liquids on the first postoperative day and a regular diet on the second. She passed flatus on postoperative day 2 and stool on day 5. She was discharged 7 days after the operation. We believe that laparoscopically assisted anterior resection offers a promising new option for the treatment of rectal prolapse.

Female↗
PubMed1992

Laparoscopic-assisted sigmoid colectomy for sigmoid volvulus.

A 75-year-old black man came to the emergency room because of nausea, vomiting, abdominal pain, and distension and obstipation. An abdominal radiograph revealed a sigmoid volvulus. This was nonoperatively reduced in the emergency room. Following a mechanical and antibiotic bowel preparation, the patient underwent elective exploration. We report, for the first time, operative treatment of sigmoid volvulus with a laparoscopic-assisted sigmoid colectomy and primary anastomosis. Because of dense fibrous scarring of the sigmoid mesentery produced by chronic mesosigmoiditis, the redundant sigmoid was exteriorized and resected extracorporeally. A stapled, side-to-side, functional end-to-end anastomosis was constructed. The patient experienced little postoperative pain and virtually no postoperative ileus. We believe that laparoscopic-assisted sigmoid resection may offer distinct advantages for the treatment of the typically elderly, debilitated patient in whom sigmoid volvulus develops. Furthermore, because of the characteristic mesosigmoiditis associated with sigmoid volvulus, we suspect that exteriorization and extracorporeal resection may prove the easiest and most rapid laparoscopic approach to this disease.

Aged↗
PubMed1992

Diagnosis and treatment of enterovesical fistulae.

Presenting symptoms, diagnostic progression, etiology, therapy, and complications of 44 patients with enterovesical fistulae who came to three Yale teaching hospitals over a 9-year period were reviewed. Patients with diverticulitis as the cause of their fistula were older and came to the hospital with pneumaturia/fecaluria. Patients with pelvic cancer were more likely to have fecaluria, gastrointestinal symptoms, or hematuria. Patients with Crohn's disease were an average of 20 years younger than the patients with cancer or diverticulitis and they came to the hospital with pneumaturia, abdominal pain, abdominal mass, and tenderness. Computerized axial tomography scanning, cystoscopy, charcoaluria, and barium enema were useful in making the diagnosis; intravenous pyelography and colonoscopy were not. One-tenth of the patients were not candidates for operation, and one-quarter of the patients did not undergo complete operative resolution with restoration of enteric and urinary continuity. Nine patients underwent a two-stage repair consisting of resection/repair of the fistula with proximal fecal diversion and subsequent re-establishment of bowel continuity. These patients had a higher morbidity than the 19 patients who underwent one-stage repair. Enterovesical fistula is a challenging entity, the etiology of which may be suspected upon taking the patient's history or performing the physical assessment; however, the definitive diagnosis of enterovesical fistula can remain elusive. Single-stage repair can be achieved with low morbidity and mortality in many candidates.

Adolescent↗
PubMed1991

Adaptive increase in peptide YY and enteroglucagon after proctocolectomy and pelvic ileal reservoir construction.

Functional results improve with time after proctocolectomy and pelvic ileal reservoir construction. We hypothesized that adaptive increases of circulating and tissue levels of the gut hormones peptide YY (PYY) and enteroglucagon may contribute to this improvement by slowing small bowel transit and increasing small bowel absorption. The specific aim of this study was to measure plasma and ileal mucosal concentrations of PYY and enteroglucagon in dogs 1 year after proctocolectomy and ileal reservoir-anal anastomosis. In the ileal reservoir dogs, postprandial PYY levels reached 238 +/- 31 pmol/liter compared with 93 +/- 33 pmol/liter in sham operated controls (P less than 0.001). Postprandial plasma enteroglucagon levels reached 199 +/- 53 pmol/liter in reservoir animals and 52 +/- 4 pmol/liter in controls (P less than 0.05). Tissue levels of PYY in the mucosa of the ileal reservoirs were 419 +/- 43 pmol/g compared with 133 +/- 23 pmol/g in normal terminal ileum (P less than 0.0001). Enteroglucagon levels were also elevated in reservoir mucosa (193 +/- 21 pmol/g vs. 113 +/- 9 pmol/g in controls, P less than 0.05). These data demonstrate that postprandial and tissue levels of PYY and enteroglucagon increase in dogs 1 year after construction of ileal reservoirs. The adaptive increase in PYY would slow small bowel transit and the increase in enteroglucagon would promote mucosal growth, each contributing to the improved functional results.

Adaptation, Physiological↗
PubMed1991

Distribution and immunocytochemical colocalization of peptide YY and enteroglucagon in endocrine cells of the rabbit colon.

Peptide YY (PYY) is 36 amino acid peptide hormone present in high concentrations in the colon where it is colocalized with enteroglucagon in L cells. A selective release of PYY and enteroglucagon from the rabbit colon has been described, raising the question of the exact localization of the two hormones in the rabbit colon. We have therefore examined the distribution of PYY and enteroglucagon as well as somatostatin in the rabbit colon using RIA and electron microscopic immunocytochemistry. PYY and enteroglucagon were present in high concentrations in the colorectal mucosa with peak concentrations in the left colon (PYY 544 +/- 87 pmol/g, enteroglucagon 152 +/- 10 pmol/g). Electron microscopic examination of the colonic mucosa demonstrated a large population (65%) of EC cells, a moderate population (30%) of L cells, and a small population (5%) of D cells. By immunogold labeling serotonin was localized to EC cells, PYY and enteroglucagon to L cells, and somatostatin to the D cell. Double immunogold labeling revealed PYY and enteroglucagon in all L cells examined (93 cells). A majority of the secretory granules (83%) were labeled by both PYY and glucagon antibodies, whereas a significant portion of granules (15%) was labeled by the PYY antibodies alone. The results demonstrate that L cells are the sole source of PYY and enteroglucagon in the rabbit colon and that L cells contain different populations of secretory granules. The existence of different secretory granules in L cells may explain the selective release of PYY and enteroglucagon observed in the rabbit colon.

Animals↗
PubMed1991

Short-chain fatty acid release of peptide YY in the isolated rabbit distal colon.

Short-chain fatty acids (SCFAs) form the major ionic fraction of stool, provide the major metabolic substrate for colonic epithelium, and promote mucosal ion transport. Despite this prominent role of SCFAs in metabolism of the colon, their effect on colonic endocrine cell function has not been studied. Consequently, we hypothesized that SCFAs might modulate release of peptide YY (PYY) from colonic type-L endocrine cells. The specific aims of this study were to measure release of PYY from the isolated perfused rabbit distal colon stimulated by intraluminal infusion of 0.9% saline, acetate (10 mM), acetoacetate (10 mM), n-butyrate (1, 3.3, 10, 100 mM), and pyruvate (10 mM). PYY levels were measured by radioimmunoassay in the venous effluent of the rabbit colon. All four SCFAs (10 mM) caused at least a twofold increase in integrated release of PYY from the isolated perfused rabbit colon. Graded concentrations of n-butyrate caused a stepwise release of PYY. This study suggests that SCFAs may modulate the release of colonic PYY in rabbits.

Acetates↗
PubMed1990

Increasing incidence of cecal and sigmoid carcinoma. Data from the Connecticut Tumor Registry.

We have studied both the distribution and incidence of colorectal cancer using The Connecticut Tumor Registry, the oldest tumor registry in the United States. During the time period 1973 to 1985, left-sided colon cancers accounted for 63% of the cancers, right-sided cancers 33%, and cancers with unspecified sites 4%. Indeed, this pattern of distribution has remained constant for 25 years. For the period 1935 to 1985, we calculated the sex-specific, age-adjusted (normalized to the 1970 U.S. Census) incidence. Age-adjusted incidence of rectal cancer has remained stable for 50 years: for men, 22.8 cases/100,000/year, and for women, 13.9 cases/100,000/year. During these 50 years, the age-adjusted incidence of cecal carcinoma for men has increased from 3.6 to 16.7 cases/100,000/year, while for women, it has increased from 4.9 to 14.2 cases/100,000/year. Sigmoid carcinoma for men has increased from 8.8 to 18.7 cases/100,000/year, and for women, it has increased from 7.7 to 12.8 cases/100,000/year. The incidence of colon cancer at each site has been and continues to be increasing at a constant rate. Age-adjusted incidence for all colorectal cancers has increased from 35.2 to 70.2 cases/100,000/year for men and from 32.1 to 49.2 cases/100,000/year for women. Thus, distribution of colorectal cancers by site in Connecticut has remained stable for 25 years. More importantly, however, the age-adjusted incidence of colon cancer has continued to increase for 50 years, whereas that of rectal cancer has remained relatively stable.

Cecal Neoplasms↗
PubMed1990

Neuropeptide Y inhibition of vasoactive intestinal polypeptide-stimulated ion transport in the rabbit distal colon.

We have studied the effect of neuropeptide Y on basal and vasoactive intestinal polypeptide-stimulated changes in the short-circuit current of strips of colonic mucosa from New Zealand white rabbits mounted in Ussing chambers. When administered to the basolateral surface, neuropeptide Y is found to decrease basal short-circuit current. Neuropeptide Y inhibits vasoactive intestinal peptide-stimulated increases in short-circuit current in a concentration-dependent fashion by a tetrodotoxin-insensitive mechanism. Also, neuropeptide Y inhibited increases in short-circuit current produced by direct stimulation of adenylate cyclase with forskolin. Furthermore, neuropeptide Y prevents vasoactive intestinal peptide-stimulated increases in tissue cyclic adenosine monophosphate levels. These results indicate that neuropeptide Y administered to the basolateral membrane inhibits vasoactive intestinal peptide-stimulated short-circuit current changes by a tetrodotoxin-insensitive mechanism that decreases tissue levels of cyclic adenosine 3',5'-monophosphate.

Animals↗
PubMed1990

Gastrointestinal malignancies in Crohn's disease. A 20-year experience.

The relationship between gastrointestinal neoplasms and Crohn's disease is poorly defined. The purpose of this study was to characterize the features of gastrointestinal malignancies that developed in Crohn's patients. In this retrospective review the authors identified six patients with Crohn's disease who developed such lesions over a 20-year period: four patients had colorectal cancers and two had ileal malignant neoplasms. Patients averaged 52.7 years of age (range, 21 to 61 years). Three patients were men and three women. Five of the six patients had endured Crohn's disease for more than 20 years. Only two lesions were diagnosed before surgery. The colorectal lesions were predominantly right-sided and all occurred in bowel segments with active Crohn's disease. The lesions demonstrated aggressive histologic features: three of six tumors were poorly differentiated, one of the five adenocarcinomas was mucinous, and three of the colorectal cancers were Dukes' B or C lesions. Four of six patients survived five or more years. There was a single malignant carcinoid, which represents the seventh case report of a carcinoid tumor occurring in a patient with Crohn's disease. This study indicates that patients with Crohn's disease develop a wide variety of small bowel and colorectal cancers. Furthermore, it suggests that Crohn's patients with colonic disease should periodically undergo surveillance colonoscopy.

Adenocarcinoma↗
PubMed1990

Colorectal disease in spinal cord patients. An occult diagnosis.

Undiagnosed abdominal emergencies account for 10 percent of all fatalities among patients with spinal cord injuries. A large number of these emergencies involve the lower gastrointestinal tract. The purpose of this study is to bring attention to the occult nature of colorectal disease in spinal cord patients and to highlight the subtle, but characteristic, symptoms and signs that develop in these patients. The authors identified 13 spinal cord patients in whom a lesion developed in either the appendix, colon, rectum, or anus. The average age of all patients was 36.2 years. Trauma and multiple sclerosis were the most common etiology of spinal cord injury. The most common presenting symptoms were abdominal distention, vomiting, and constipation. The average delay in diagnosis of the colorectal disease was 35.8 hours. An 84% morbidity and 22% mortality were observed. This study indicates that any deviation from the normal lifestyle of the spinal cord patient should alert one to the possibility of visceral inflammation. Furthermore, close attention to the signs of autonomic dysreflexia or changes in spasticity, along with a thorough evaluation of the ill-appearing spinal cord patient, may uncover occult colonic or rectal disease.

Adolescent↗
PubMed1990

Malignant potential of juvenile polyposis coli. Report of a case and review of the literature.

Juvenile polyps of the colon and rectum traditionally have been viewed as being benign inflammatory or harmartomatous lesions without potential for malignant change. The authors report a case of adenocarcinoma developing in a patient with sporadic juvenile polyposis. Juvenile polyposis was diagnosed in the patient at age 4 years. He underwent subtotal colectomy at age 6 years. At age 12, he underwent a proctectomy and a Swenson pull-through because of adenomatous changes in the rectal stump. At age 19 surveillance endoscopy revealed invasive cancer in a juvenile polyp.

Adenocarcinoma↗
PubMed1990

The adenoma to carcinoma sequence.

The frequent coexistence of adenoma with primary carcinoma of the colon and their association with higher incidences of both synchronous and metachronous carcinomas offers only circumstantial evidence that adenomas are premalignant lesions. Detailed histopathologic investigations, however, have documented the transition from adenoma to carcinoma. Although the common, minute adenomatous polyp has a low potential of malignancy, the risk increases with size, villous architecture and degree of epithelial dysplasia. Furthermore, the association of dysplasia, which shares many adenomatous features with carcinoma in patients with chronic ulcerative colitis, and the inevitable development of adenomatous polyps followed by carcinoma of the colon and rectum in patients with familial polyposis further support this concept. Most colorectal malignant lesions, therefore, are believed to progress through the adenoma to carcinoma sequence. Moreover, histochemical investigations have demonstrated that abnormalities of DNA content, enzyme activities, CEA expression and mucin composition are shared by both adenoma and carcinoma. Thus, the malignancy potential of adenoma of the colon and rectum is reflected not only in the overt histologic transition to carcinoma, but in the disruption of the genetic and biochemical control mechanisms of cellular function as well.

Adenoma↗