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Biomedical subjects

F E Eckhauser

Publications and source records attributed to F E Eckhauser.

At least 19 recordsLinked to original sources

Phase I trial of radiation dose escalation with concurrent weekly full-dose gemcitabine in patients with advanced pancreatic cancer.

PURPOSE: The primary objective of this phase I trial was to determine the maximum-tolerated dose of radiation that could be delivered to the primary tumor concurrent with full-dose gemcitabine in patients with advanced pancreatic cancer. PATIENTS AND METHODS: Thirty seven patients with unresectable (n = 34) or incompletely resected pancreatic cancer (n = 3) were treated. Gemcitabine was administered as a 30-minute intravenous infusion at a dose of 1,000 mg/m(2) on days 1, 8, and 15 of a 28-day cycle. Radiation therapy was initiated on day 1 and directed at the primary tumor alone, without prophylactic nodal coverage. The starting radiation dose was 24 Gy in 1.6-Gy fractions. Escalation was achieved by increasing the fraction size in increments of 0.2 Gy, keeping the duration of radiation constant at 3 weeks. A second cycle of gemcitabine alone was intended after a 1-week rest. RESULTS: Two of six assessable patients experienced dose-limiting toxicity at the final planned dose level of the trial (42 Gy in 2.8-Gy fractions), one with grade 4 vomiting and one with gastric/duodenal ulceration. Two additional patients at this dose level experienced late gastrointestinal toxicity that required surgical management. CONCLUSION: The final dose investigated (42 Gy) is not recommended for further study considering the occurrence of both acute and late toxicity. However, a phase II trial of this novel gemcitabine-based chemoradiotherapy approach, at a radiation dose of 36 Gy in 2.4-Gy fractions, is recommended on the basis of tolerance, patterns of failure, and survival data.

Adenocarcinoma↗

Doctor-patient communication in surgery: attitudes and expectations of general surgery patients about the involvement and education of surgical residents.

BACKGROUND: Education is a major function of academic medical centers. At these teaching institutions residents provide a substantial amount of care on medical and surgical services. The attitudes of patients about the training of surgical residents and the impact of residents on patients' perceptions of care in a surgical setting are unknown. STUDY DESIGN: Patients admitted to the gastrointestinal surgery service completed a 30-item survey designed for this study. Patients included in the study underwent operations and had a postoperative inpatient hospital stay. We analyzed patients' answers to determine frequency and correlations among answers. RESULTS: Two hundred patients participated in the study during a 7-month period between July 1999 and January 2000. A majority of patients were comfortable having residents involved in their care (86%) and felt it was important to help educate future surgeons (91%). Most did not feel inconvenienced by being at a teaching hospital (71%) and felt they received extra attention there (74%). Patients were more willing to participate in resident education if they expected to have several physicians involved in their care, felt that they received extra attention, or if the teaching atmosphere did not inconvenience them. Despite the stated willingness of patients to help with surgical resident education, 32% answered that they would not want residents doing any of their operation. CONCLUSIONS: Surgical resident education is well received and considered important by patients. Patient orientation to the resident education process is vital to patients' perceptions of care and may render patients more willing to participate in educational activities.

Academic Medical Centers↗

Burnout among American surgeons.

BACKGROUND: The long-term consequences of stress on the surgeon are unknown. One manifestation of stress is burnout. The purpose of this study was to measure the prevalence of burnout in actively practicing American surgeons. METHODS: The Maslach Burnout Inventory and a questionnaire of our own design were sent to 1706 graduates of various University of Michigan surgical residencies (1222) and members of the Midwest Surgical Association (484). The response rate was 44%. Responses from 582 actively practicing surgeons were the sample used for analysis. RESULTS: Thirty-two percent of actively practicing surgeons showed "high" levels of emotional exhaustion, 13% showed "high" levels of depersonalization, and 4% showed evidence for low personal accomplishment. Younger surgeons were more susceptible to burnout (r = -0.28, P <.01). Burnout was not related to caseload, practice setting, or percent of patients insured by a health maintenance organization. Important etiologic factors were a sense that work was "overwhelming" (r = 0.61, P <.01), a perceived imbalance between career, family, and personal growth (r = -0.56), P <.01), perceptions that career was unrewarding (r = -0.42, P <.01), and lack of autonomy or decision involvement (r = -0.39, P <.01). A strong association was noted between burnout elements and a desire to retire early (r = 0.50, P <.01). CONCLUSIONS: Burnout is an important problem for actively practicing American surgeons. These data could be used to modify existing surgical training curricula or as an aid to surgical leadership when negotiating about the surgical work environment.

Adult↗

Hereditary chronic pancreatitis: implications for surgical treatment and follow-up.

Hereditary pancreatitis is an uncommon cause of chronic pancreatitis in Western society. It should be suspected when chronic pancreatitis presents in young adults. The diagnosis is made when chronic pancreatitis is present in several members of the same family who are determined not to have other risk factors for chronic pancreatitis. Molecular research focusing on mutations in the trypsinogen gene has uncovered the genetic defects associated with hereditary pancreatitis, and this knowledge has suggested the possible pathophysiologic mechanism of this disease. Because patients with hereditary pancreatitis develop their disease early in life they are very likely to require treatment for complications. As in patients with chronic pancreatitis of other etiologies those with hereditary pancreatitis should be treated medically for acute exacerbations. When complications occur or when the disease causes intractable pain surgery is recommended. Surgical therapy is tailored to the patient's pancreatic anatomy based on endoscopic retrograde cholangiopancreatography or CT scan. The two patients described in this report underwent successful longitudinal pancreaticojejunostomy (Puestow procedure) with good results. Finally it has been shown that patients with hereditary pancreatitis are at increased risk for developing pancreatic adenocarcinoma. Although not widely used pancreatic cancer screening programs have been suggested for surveillance of these patients.

Abdominal Pain↗

Safety and long-term durability of completion gastrectomy in 81 patients with postsurgical gastroparesis syndrome.

Postsurgical gastroparesis syndrome (PGS) is characterized by postcibal nausea and vomiting and is associated with functional gastric dysmotility. Patients frequently present with marked weight loss and malnutrition requiring hospitalization and prolonged parenteral nutrition. Typically, these patients fail to respond to prokinetic agents. Gastric reoperations are frequent and usually unsuccessful. Near-completion gastrectomy (NCG) has proved useful in small series of patients, but long-term follow-up has been lacking. The purpose of this study is to assess the safety and durability of NCG in a large group of patients with PGS. Eighty-one patients with documented PGS who failed to respond to prokinetic drug therapy were treated with NCG over an 11-year period. NCG was standardized with a 55-cm Roux-en-Y reconstruction. Patients were evaluated by a retrospective chart review and a prospective phone interview that compared pre- and postoperative health status based on a standardized severity of symptoms score. There were no operative deaths or complications related to the anastomosis. Average patient follow-up was 56.1 months (range, 2-142 months). Fifteen patients died of unrelated causes, and 14 patients were lost to follow-up. The remaining 52 patients showed a significant overall decrease in severity of symptoms score largely due to reduction in gastrointestinal symptoms and to a smaller but significant reduction in systemic symptoms. Nearly 80 per cent of patients reported long-term relief of symptoms. NCG is the procedure of choice for carefully selected patients with documented. Low morbidity and durable results can be anticipated in the majority of patients.

Adult↗

Treatment of cirrhotic rats with epidermal growth factor and insulin accelerates liver DNA synthesis after partial hepatectomy.

Prevention of postoperative hepatic failure is important after hepatic resection. In patients with cirrhosis, impaired liver function and regenerative capacity after major hepatic resection are associated with increased morbidity and mortality. In this study, a combination of epidermal growth factor (EGF) and insulin were used as hepatotrophic factors in an attempt to stimulate DNA synthesis after 70% hepatectomy (HTX). Regenerative capacity was evaluated in normal and cirrhotic rat liver by measuring DNA synthesis in vivo. Micronodular liver cirrhosis was established by the simultaneous oral administration of CCl4 and phenobarbital. Epidermal growth factor plus insulin was injected subcutaneously immediately after and 12 h after HTX or sham operation was performed. Rats were killed 24 h after the operation and liver regeneration was estimated by [3H]-thymidine incorporation into DNA as well as an autoradiographic nuclear labelling index. Hepatectomy increased [3H]-thymidine incorporation significantly in both normal and cirrhotic rats. In cirrhotic rats, [3H]-thymidine incorporation after HTX was significantly lower than in normal rats and administration of a combination of EGF and insulin after HTX enhanced [3H]-thymidine incorporation. In conclusion, DNA synthesis 24 h after HTX is decreased in cirrhotic rats compared with normal rats and EGF supplementation with insulin accelerates DNA synthesis in hepatectomized cirrhotic rats. The data suggest that administration of combinations of exogenous hepatotrophic factors may play a useful role in the treatment of cirrhotic patients undergoing major hepatic resection.

Animals↗

Surgery for primary and metastatic colorectal cancer.

Carcinoma of the colon and rectum currently ranks as the second leading cause of death from cancer in the United States. Surgery remains the cornerstone of treatment for colorectal cancer but has inherent limitations imposed by the biology and stage of the tumor and its location. Ultimately, 50% of patients who undergo curative resection develop local, regional, or widespread recurrence. These statistics have remained relatively constant over several decades despite improved methods of early diagnosis and surgical treatment but may change as new multimodality treatment regimens are developed and clinically evaluated. This article summarizes the surgical management of colorectal cancer and discusses issues pertaining to postoperative surveillance and the diagnosis and management of local or widespread cancer recurrence.

Anastomosis, Surgical↗

Multimodality staging optimizes resectability in patients with pancreatic and ampullary cancer.

Few patients with pancreatic cancer have resectable disease at the time of diagnosis, and a variety of nonsurgical techniques are available to provide effective palliation of jaundice and pain. Accurate preoperative staging is essential to identify patients with unresectable disease, thereby minimizing unnecessary surgery. Currently used diagnostic tests include contrast-enhanced computerized tomography (CT), visceral angiography, endoscopic ultrasound, and laparoscopy, but their utility remains controversial. To evaluate the accuracy of these various diagnostic tests, 30 consecutive patients with histologically proven pancreatic or ampullary adenocarcinoma treated between 1992 and 1996 were evaluated. All 30 patients had contrast-enhanced CT and laparoscopy, 22 patients (73%) had visceral angiography, and 16 patients (53%) had endoscopic ultrasound. Individual and combined predictive values of resectability and unresectability as well as the sensitivities and specificities were determined for all diagnostic tests and compared with intraoperative findings. When CT, visceral angiography, and laparoscopy were combined, the predictive values of resectability and unresectability were 75 and 90 per cent, respectively, with a sensitivity of 75 per cent and a specificity of 90 per cent. Therefore, the combined use of selected diagnostic tests proved more effective than any single diagnostic test for accurately staging patients with pancreatic head and ampullary cancers and should be considered to minimize unnecessary surgery.

Adenocarcinoma↗

Preferential suppression of insulin-stimulated proliferation of cultured hepatocytes by somatostatin: evidence for receptor-mediated growth regulation.

The role of somatostatin (SS-14) in the regulation of rat liver regeneration was examined by using thymidine incorporation into hepatocyte DNA labeled with tritiated thymidine, a nuclear-labeling index, and the binding of 125I-tyr11-SS-14 to hepatocytes isolated at various times after partial hepatectomy. The data demonstrated no suppressive effect of SS-14 on insulin and glucagon-stimulated thymidine incorporation into hepatocyte DNA as early as 2 h after partial hepatectomy. These data were substantiated by a nuclear labeling index studies. At 2 h, 125I-tyr11-SS-14 binding to its specific sites on isolated hepatocytes was undetectable. There was a time-dependent increase in binding of 125I-tyr11-SS-14 to hepatocytes obtained at various times after partial hepatectomy. There was a significant decrease in the number of binding sites after partial hepatectomy as determined by Scatchard analysis. The data were supported by autoradiography analysis of affinity labeled 125I-tyr11-SS-14-binding protein complex followed by SDS-PAGE. SS-14 also inhibited intracellular cAMP in hepatocytes obtained at 18 h after hepatectomy. The data are consistent with the hypothesis that SS-14 participates via its own receptor in the regulation of the liver regeneration.

Animals↗

Impaired phorbol ester-induced hepatocyte proliferation in cirrhosis.

Cirrhotic livers are considered to regenerate less actively than normal livers after hepatic resection. Little is known about the mechanisms responsible for impaired capacity of regeneration in cirrhotic liver. In the present study, we investigated the effect of phorbol ester on hepatocyte proliferation in healthy and cirrhotic hepatocytes, using one of the phorbol esters, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), which has a direct effect on activation of protein kinase C (PKC). Cirrhosis was established by the administration of carbon tetrachloride and phenobarbital to rats. Healthy and cirrhotic hepatocytes were isolated from Wistar male rats by a two-step collagenase perfusion technique. DNA synthesis was estimated by [3H]thymidine incorporation into DNA and by autoradiographic nuclear labeling index. [3H]Thymidine incorporation was measured 24 hr after hepatocytes were stimulated by appropriate reagents. TPA (50 nM) stimulated [3H]thymidine incorporation in healthy hepatocytes (control vs TPA, 991 +/- 247 vs 2569 +/- 766 mean +/- SEM cpm/microgram DNA; P < 0.05), whereas TPA (50 nM) failed to stimulate in cirrhotic hepatocytes (control vs TPA, 1144 +/- 184 vs 1304 +/- 187 cpm/microgram DNA; NS). Staurosporine, a specific PKC inhibitor, suppressed [3H]thymidine incorporation in TPA-stimulated healthy hepatocytes (806 +/- 263 cpm/microgram DNA; P < 0.05); however, it had no effect on cirrhotic hepatocytes (1295 +/- 180 cpm/microgram DNA; NS). An autoradiographic nuclear labeling index exhibited the same results with [3H]thymidine incorporation. We conclude that TPA stimulates hepatocyte proliferation in healthy rat hepatocytes but has no effect on cirrhotic hepatocytes.

Alkaloids↗

Are traditional prognostic criteria useful in pancreatic abscess?

Pancreatic abscess remains a potentially lethal disease. Efforts to relate outcome to the severity of associated pancreatitis or the type of surgical drainage employed have yielded conflicting results. This study was designed to test the validity of traditional prognostic criteria in the clinical setting of pancreatic abscess and to determine whether the technique of surgical drainage employed correlated with survival. The records of 40 consecutive patients with pancreatic abscess were reviewed. In each case the diagnosis was confirmed by operation. Prognostic factors analyzed included number of Ranson criteria, etiology, type, and number of microorganisms isolated, extent of abscess, time to diagnosis and operation, and technique of surgical drainage. Of the 11 Ranson criteria evaluated, only an elevation in blood urea nitrogen > 5 mg/dl correlated with decreased survival (p < 0.001). Polymicrobial abscesses (three or more organisms) resulted in a higher mortality than abscesses where fewer than three organisms were isolated (45.4 vs 13.8%; p < 0.05). Intraperitoneal extension of the abscess was associated with an increased mortality rate compared to those confined to the retroperitoneum (57.1 vs 15.2%; p < 0.01). In patients requiring unplanned reexploration, mortality was significantly increased (42.9 vs 11.5%; p < 0.05). The technique of surgical drainage employed (open versus closed) did not influence overall mortality (23.5 vs 21.7%; p = NS). Extent of disease at operation, polymicrobial abscess, reexploration for persistent or recurrent disease, and deterioration in renal function were all predictive of increased mortality in cases of pancreatic abscess.(ABSTRACT TRUNCATED AT 250 WORDS)

Abscess↗

Vasopressin stimulates DNA synthesis in cultured rat hepatocytes.

Liver regeneration following partial hepatectomy is significantly impaired in rats with hereditary vasopressin (AVP) deficiency. This suggested that AVP might have a direct effect on cultured rat hepatocytes. Hepatocytes from male Sprague-Dawley rats were isolated using a two-step collagenase perfusion technique and plated at a density of 10(5)/16-mm Primaria plate. After a suitable attachment period, hepatocytes were incubated with minimal essential media, AVP, AVP plus a specific AVP antagonist, or oxytocin. Hepatocyte proliferation was measured by [3H]thymidine incorporation ([3H]Thy) into hepatocyte DNA. AVP (10 nM) increased [3H]Thy significantly (and this effect was blocked by an AVP-specific antagonist (50 nM). Oxytocin had no effect on hepatocyte DNA synthesis. To further investigate the influence of AVP on hepatocyte proliferation, the effect of AVP on transforming growth factor-alpha (TGF-alpha)-stimulated hepatocyte proliferation was also studied. This combination was chosen based on the ability of AVP to inhibit the biologic effects of EGF (a TGF-alpha analog). There was significant attenuation of TGF-alpha (50 nM)-stimulated [3H]Thy in the presence of AVP (10 nM). In summary: (1) AVP stimulates proliferation of cultured rat hepatocytes. (2) The effect of AVP can be significantly abolished by a specific AVP antagonist. (3) The proliferative response of AVP is specific. (4) AVP significantly attenuates TGF-alpha-stimulated hepatocyte hepatic DNA synthesis. Further studies should elucidate the mechanisms for the effects of AVP on hepatic proliferation alone or in combination with other factors.

Animals↗

Enucleation combined with hepatic vascular exclusion is a safe and effective alternative to hepatic resection for liver cell adenoma.

Liver cell adenomas are benign, rare tumors that occur primarily in women with a history of oral contraceptive use. Surgical treatment is recommended to reduce the risk of sudden, unpredictable hemorrhage or malignant transformation, but mortality rates of 5 to 8 per cent are reported for major hepatic resections. This report summarizes an experience of eight patients with liver cell adenoma treated by enucleation or resection, alone or combined with hepatic vascular exclusion (HVE). The latter technique, originally described in the mid-1960s, markedly reduces operative blood loss associated with hepatic resection. All eight patients were women of child-bearing age, and seven reported previous oral contraceptive use. The majority of patients were asymptomatic at the time of presentation. Six patients (75%) had a single adenoma and the remaining two had multiple lesions. HVE was used successfully in four patients with no perioperative mortality and reduced by nearly 50 per cent the intraoperative blood loss compared to conventional hepatic resection (1635 mL versus 3875 mL, respectively). Six evaluable patients were followed for an average of 65 months, with no evidence of liver dysfunction or adenoma recurrence. Enucleation of liver cell adenoma appears to be a safe alternative to formal hepatic resection and provides excellent long-term results. HVE markedly reduces operative blood loss, has no adverse effect on metabolic function, decreases the potential health risk associated with transfusion, and should be used whenever possible.

Adenoma, Liver Cell↗

Cushing's syndrome secondary to bronchial carcinoid secretion of ACTH: a review.

Cushing's syndrome as a result of the ectopic production of adrenocorticotrophic hormone by bronchial carcinoids is a rare phenomena. The clinical course of two patients is presented in depth, and a review of the literature is provided. A discussion of various forms of therapy and an algorithm for the evaluation and management of the patients is presented.

Adolescent↗

Inhibition of DNA synthesis by somatostatin in rat hepatocytes stimulated by hepatocyte growth factor or epidermal growth factor.

The antiproliferative effects of somatostatin on hepatocytes stimulated by hepatocyte growth factor (HGF) or epidermal growth factor (EGF) were investigated using primary cultures of adult rat hepatocytes. Somatostatin inhibits HGF-induced (at a dose of 10 ng/mL) or EGF-induced (at a dose of 100 ng/mL) 3H-thymidine incorporation into hepatocytes in a dose-dependent manner (10(-10) to 10(-8) M). This inhibition was confirmed by autoradiography. The effect of somatostatin was nontoxic as judged by preserved albumin synthesis, a marker for differentiated hepatocyte function. In the presence or absence of somatostatin, neither HGF nor EGF significantly altered intracellular cyclic adenosine monophosphate (cAMP). We conclude that somatostatin is a potent inhibitor of HGF- or EGF-induced deoxyribonucleic acid synthesis in adult rat hepatocytes. The mechanism of this inhibition appears to be independent of cAMP. The significance of somatostatin in liver regeneration has yet to be assessed.

Animals↗

Transforming growth factor-alpha (TGF-alpha) improves hepatic DNA synthesis after hepatectomy in cirrhotic rats.

Impaired liver regeneration in cirrhosis complicates the surgical treatment of liver tumors which arise in this setting. We developed a rat model to investigate the regenerative response of cirrhotic liver after hepatectomy and studied the effect of exogenous transforming growth factor-alpha (TGF-alpha), a potent liver mitogen. Micronodular cirrhosis was established by the simultaneous administration of CCl4 and phenobarbital. Hepatic DNA synthesis ([3H]thymidine incorporation into DNA) 24 hr after partial hepatectomy in cirrhotic rats was 15.6 +/- 3.4 cpm/micrograms DNA (means +/- SEM), which was significantly lower than in normal rats (37.3 +/- 3.4 cpm/micrograms DNA, P less than 0.05). Exogenous TGF-alpha (30 nmol/kg, sc every 12 hr) significantly improved [3H]thymidine incorporation (35.6 +/- 8.2 cpm/micrograms DNA, P less than 0.05). An autoradiographic nuclear labeling index also confirmed increased DNA synthesis (6.7% vs 13.4%). TGF-alpha had no effect on normal regenerating liver (42.5 +/- 8.8 cpm/micrograms DNA, NS). Although the significance of TGF-alpha-enhanced liver regeneration in cirrhosis has yet to be assessed, this model may be useful for the study of mechanisms which control hepatic proliferation.

Animals↗