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Biomedical subjects

W E Longo

Publications and source records attributed to W E Longo.

At least 109 records · Page 6Linked to original sources
PubMed1991

Mineral fiber content of lung tissue in patients with environmental exposures: household contacts vs. building occupants.

Analysis of tissue mineral fiber content in patients with environmental exposures has seldom been reported in the past. Our studies of six household contacts of asbestos workers indicate that these individuals often have pulmonary asbestos concentrations similar to some occupationally exposed individuals. In contrast, our studies of four occupants of buildings with asbestos-containing materials indicate that these individuals often have pulmonary asbestos burdens indistinguishable from the general nonoccupationally exposed population. However, one such building occupant exposed for many years and who later developed pleural mesothelioma was studied in detail, and it was concluded that her exposure as a teacher's aide in a school building containing acoustical plaster was the likely cause of her mesothelioma.

Adult↗
PubMed1991

Exposure to airborne asbestos associated with simulated cable installation above a suspended ceiling.

Installing cable above a suspended ceiling in the presence of asbestos-containing fireproofing is an example of an activity that may disturb in-place asbestos and associated dust and debris. Two simulations of cable installation were conducted in a room of an unoccupied school to test the extent of such disturbance and resulting elevations in airborne asbestos. Average airborne asbestos concentrations in the room increased over 500-fold during the simulations, with several samples exceeding 50 structures per cubic centimeter (s/cm3), as measured by transmission electron microscopy (TEM) with an indirect preparation technique. Elevated concentrations persisted during a subsequent cleaning of horizontal surfaces in the room and for several hours thereafter. Personal samples collected on the cable installers yielded TEM measurements averaging approximately 68 s/cm3 for the two simulations.

Air Pollutants↗
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

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 increasing prevalence of acalculous cholecystitis in outpatients. Results of a 7-year study.

Acute acalculous cholecystitis (AAC) is a disease that causes high rates of morbidity such as those traditionally observed in the critically ill. Recently we noted an increase in the de novo presentation of outpatients with this disease. Our aim was to characterize this disease in outpatients, identify risk factors, and assess clinical outcome. Therefore a 7-year review of the Yale experience with AAC was undertaken. Forty-seven patients were identified. Seventy-seven per cent (36 of 47 patients) developed AAC at home without evidence of acute illness or trauma, while 23% (11 of 47 patients) developed the disease while hospitalized. Significant vascular disease was observed in 72% of outpatients. A 38% morbidity rate and 6% mortality rate were observed. We conclude that AAC occurs commonly in elderly male outpatients with vascular disease and that these patients incur significant morbidity in association with this condition. AAC should be suspected and prompt surgical management instituted when these patients present with an acute right upper quadrant inflammatory process.

Acute Disease↗
PubMed1990

Does visceral ischemia play a role in the pathogenesis of acute acalculous cholecystitis?

Acute acalculous cholecystitis is a virulent disease of uncertain etiology observed most commonly in critically ill patients. Although the precise mechanism is unknown, the most commonly postulated theories regarding its pathogenesis are bile stasis, sepsis, and ischemia. The role of ischemia in this process, whose etiology is multifactorial, has been difficult to elucidate. Consequently, we report two patients who developed acute acalculous cholecystitis without apparent risk for the disease other than severe visceral atherosclerosis. Both patients had symptomatic mesenteric vascular disease requiring revascularization and developed fulminant acalculous cholecystitis temporally related to exacerbation of their visceral ischemia. These cases suggest that patients with visceral atherosclerosis may be at increased risk for acute acalculous cholecystitis, perhaps due to impaired mucosal resistance when other factors, such as bile statis and sepsis, are also present.

Acute Disease↗
PubMed1989

The colon, anorectum, and spinal cord patient. A review of the functional alterations of the denervated hindgut.

As humans have become more mechanized, the number of persons sustaining spinal cord injuries resulting in quadriplegia or paraplegia has increased. Because colorectal function is modulated by a combination of neural, hormonal, and luminal influences, many of the normal regulatory mechanisms remain intact in patients with spinal cord injuries. Management of these patients, however, requires an understanding of altered function in the denervated hindgut. The foregut and midgut are innervated by parasympathetic fibers in the vagus and sympathetic fibers from the lower six thoracic vertebra. In contrast, the hindgut is innervated by parasympathetic fibers arising from the sacral plexus and sympathetic fibers from the lumbar spinal column. Consequently, in most spinal cord injuries, the foregut and midgut remain normally innervated whereas the hindgut looses input from cerebral and spinal cord sources. In high cord lesions this results in decreased colonic motility. In low cord injuries there is loss of inhibitory influences that normally down-regulate left colonic and rectosigmoid sphincter activity. This increased motility causes a loss of left colonic compliance and increases left colonic transit, thus leading to chronic constipation. At the same time in both high and low cord injuries, reflex activity of the anorectum is left unregulated by cerebral input. Once stimulated by distention, the rectum spontaneously evacuates its contents. Thus, fecal impaction and incontinence in these patients principally results from loss of inhibitory influences on rectosigmoid sphincter activity and on rectal reflex activity.

Animals↗
PubMed1989

Nonoperative management of adult blunt splenic trauma. Criteria for successful outcome.

Nonoperative management of blunt splenic trauma in adults is controversial despite numerous reports advocating this mode of therapy. Blunt splenic trauma is frequently managed without operation at our institution and, to define criteria that may predict a successful outcome, a retrospective review (1980 to 1988) of all adult splenic injuries was undertaken. Splenic injuries were documented by scintillation studies, CAT scanning, or at laparotomy. Sixty of 252 (24%) splenic injuries were initially treated without operation, which included bed rest, ICU monitoring, frequent physical exams, nasogastric tube, serial hematocrits, and follow-up splenic imaging. Five patients (5 of 60) failed nonoperative management and required interval laparotomy. Reasons for failure included blood loss greater than four units, enlarging splenic defect, or increasing peritoneal signs. Parameters predicting a successful outcome were localized trauma to the left flank or abdomen, hemodynamic stability, transfusion requirements less than four units, rapid return of GI function, age less than 60 years, and early resolution of splenic defects on imaging studies. No morbidity or deaths resulted from delayed operative intervention. In carefully selected adult patients, blunt splenic trauma may be successfully managed without operation.

Adolescent↗
PubMed1989

Deoxycholate-stimulated release of peptide YY from the isolated perfused rabbit left colon.

The purpose of this study was 1) to measure the effect of graded concentrations of oleic acid and deoxycholic acid (DCA) on the release of peptide YY (PYY) and enteroglucagon and 2) to test whether DCA-stimulated release of PYY was neurally mediated by blocking neuronal conduction with tetrodotoxin. Studies were performed in isolated left colons from New Zealand White rabbits. Oleic acid in concentrations from 0.22 to 22 mM suspended in 10 mM DCA significantly stimulated release of PYY (P less than 0.01) but resulted in no graded response (Bartlett's test, P = 0.15). Similarly, oleic acid (2.2 mM) suspended with ursodeoxycholic acid (10 mM) produced no increased release of PYY above that achieved by ursodeoxycholic acid alone. In contrast, oleic acid (2.2 and 22 mM suspended with 10 mM DCA) produced a graded release of enteroglucagon during the stimulated period. Deoxycholic acid caused a concentration-dependent release of PYY (1, 3.3, 10, and 25 mM) during the stimulated period. Deoxycholic acid (1 and 10 mM) did not significantly increase enteroglucagon release. Tetrodotoxin blockade had no effect on release of PYY stimulated by 10 mM DCA. Because PYY and enteroglucagon are both found in colonic endocrine cells, these results suggest that the release of PYY and enteroglucagon are mediated by specific secretagogues and not simply caused by noxious effects of the agonists. Also, this study has demonstrated that DCA-stimulated release of PYY is not dependent on neuronally mediated mechanisms.

Animals↗
PubMed1989

Malignant diathesis from jejunal-ileal carcinoids.

A facet of carcinoid tumors often not recognized is their close association with other, noncarcinoid malignancies. The clinical course of two patients with multiple ileal-jejunal carcinoids and multiple other noncarcinoid malignancies is described. These patients were found to have elevated circulating levels of gastrin, bombesin, glucagon, enteroglucagon, pancreatic polypeptide, and peptide tyrosine tyrosine. These regulatory peptides have been demonstrated to promote trophic effects on the gastrointestinal tract as well as malignant tumors. We propose that the release of these bioactive hormones into the portal and systemic circulation by carcinoid tumors may play some role in their association with these multiple second tumors.

Adolescent↗
PubMed1989

Blunt hollow viscus injuries of the digestive tract: a poorly recognized phenomenon.

A review of records from admission to the trauma center at Yale-New Haven Hospital for a five year period (July 1981 through June 1986) revealed 41 blunt hollow viscus injuries in 31 patients. Organs injured included small intestine (18), large intestine (14), duodenum (6), stomach (2), and gall bladder (1). The most accurate predictors of blunt hollow viscus injury were peritoneal lavage (91%, n = 14) and abdominal tenderness (50%). Seventeen patients underwent early celiotomy with morbidity and mortality rates of 16% each. Nonetheless, 13 patients had delay in diagnosis with substantially higher morbidity (46%) and mortality (31%). Blunt hollow viscus injuries are uncommon, are difficult to diagnose, and can lead to major morbidity and mortality when diagnosis is delayed.

Accidents, Traffic↗
PubMed1989

Detection of early gastric cancer in an aggressive endoscopy unit.

Early Gastric Cancer (EGC) is defined as tumor invasion limited to the mucosa and submucosa, irrespective of regional lymph node involvement. These patients have five-year survival rates in excess of 90 per cent. Although frequently seen in Japan, the detection of ECG remains uncommon in the United States. Twenty-two patients with EGC over a 15-year period were reviewed. EGC was identified in 0.5 per cent (1/207) of all gastric cancers before the widespread use of endoscopy (1972-1979) in our institution and in 16.5 per cent (21/127) of such patients after endoscopy began to replace barium contrast studies (1980-1987). Radiographic studies were performed initially in 14 out of 22 patients with EGC, and in ten patients were reported as normal. Endoscopy was used to make the diagnosis of EGC in 21 of 22 patients. Nineteen of the 22 patients are currently alive and free of disease (86%) with a mean follow-up of 3.4 years (range 6 months to 12 years). Our experience has paralleled that of the Japanese in that, with the adoption of fiberoptic endoscopy as the first-line diagnostic modality in patients with GI complaints, the detection of EGC has significantly increased.

Adult↗
PubMed1988

Treatment of Crohn's colitis. Segmental or total colectomy?

In our institution, segmental Crohn's colitis has been treated with segmental colectomy rather than more extensive resection. The purpose of this study was to review the rate of recurrence following surgical treatment of Crohn's colitis using this approach. From 1974 through 1984, 37 patients with Crohn's disease limited to the colon or rectum underwent resection. Average time of follow-up was 5.5 years. There were recurrences in 13 (62%) of 21 patients treated by segmental colectomy and four (67%) of six patients treated by total abdominal colectomy and small-bowel recurrences in two (20%) of ten patients treated by proctocolectomy. Intestinal continuity was maintained in 17 (81%) of the 21 patients treated by segmental resection. Although recurrence is likely, segmental colectomy improves the quality of life by delaying the need for a stoma and by preserving functioning bowel.

Adult↗
PubMed1988

Advanced rectal cancer. What is the best palliation?

The best treatment of advanced rectal cancer remains uncertain. The aim of this study was to determine the outcome after palliative procedures in patients with advanced rectal cancer. One hundred and three patients treated over a seven-year period were identified, including 30 with local invasion, 18 with local metastases, and 55 with distant metastases. Patients were grouped into two groups: those who underwent palliative resection (68) and those who were treated without rectal resection (55). The nonresected group included patients who underwent diverting colostomies (28) and those who received multimodality therapy without surgery (7). The average age of all patients was 63.1 years. Patients in the nonresected group had more distant disease (68 percent) than the resected group (46 percent). Significant pelvic pain was a more common problem in the nonresected group (15 percent) than in the resected group (4 percent). Similarly, pelvic sepsis was more common in the nonresected group (14 percent) than in the resected group (9 percent). Postoperative mortality was 4.3 percent after palliative resection and 3.8 percent after diverting colostomy. Survival of the resected group at one year was 65 percent and at two years 20 percent. Survival of the nonresected group at one year was 20 percent and at two years 0 percent. Survival in the resected group was significantly (P less than .01) better than the nonresected group but probably can be attributed to the more extensive disease generally present in the patients who did not undergo resection. These results suggest that patients with advanced rectal cancers should undergo palliative resection whenever possible because resection decreases pelvic complications and may improve quality of life.

Adult↗
PubMed1988

Colonoscopic detection of early colorectal cancers. Impact of a surgical endoscopy service.

The Surgical Endoscopy Service has been aggressively evaluating gastrointestinal symptoms with colonoscopy and screening asymptomatic patients with flexible sigmoidoscopy in hopes of finding early curable colorectal cancers. The purpose of this study was to compare the stages of colorectal cancers resected during the 18-month period prior to (Pre-SES) and during the first 18 months (Post-SES) after the creation of the Surgical Endoscopy Service. In addition, the yield of lesions that would have been obtained by depending upon patient symptoms or occult blood testing were determined. A total of 361 colonoscopies were performed Pre-SES and 874 colonoscopies Post-SES; 26 patients underwent resection of colorectal cancers Pre-SES and 32 Post-SES. Whereas early colorectal cancers (Dukes' A and B1) were found in only three patients (12%) Pre-SES period, early cancers were found in 13 (41%) Post-SES. Doubling the number of colonoscopies produced a fourfold increase in the number of early lesions. Furthermore, disseminated cancers (D lesions) dropped from 19% Pre-SES to 3% Post-SES. Among the total 58 patients, 43% of the A lesions and 40% of the B1 lesions were asymptomatic. Even more alarming, 86% of the A lesions, 50% of the B1 lesions, 31% of the B2 lesions, and 14% of the C2 lesions were occult blood negative. Indeed, only the D lesions were uniformly occult blood positive. This study demonstrates that aggressive colonoscopy detects early colorectal cancers. Moreover, patient symptoms or occult blood testing will fail to indicate the majority of early colorectal cancers.

Aged↗