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Biomedical subjects

D L Bartlett

Publications and source records attributed to D L Bartlett.

At least 19 recordsLinked to original sources
PubMed2001

Systemic cancer therapy with a tumor-selective vaccinia virus mutant lacking thymidine kinase and vaccinia growth factor genes.

We have demonstrated previously the oncolytic effects of a systemically delivered, replicating vaccinia virus. To enhance the tumor specificity of this vector, we have developed a combined thymidine kinase-deleted (TK-) and vaccinia growth factor-deleted (VGF-) vaccinia virus and investigated its properties in vitro and in vivo. The gene for enhanced green fluorescent protein (EGFP) was inserted into the TK locus of a VGF- vaccinia virus by homologous recombination creating a double-deleted mutant vaccinia virus (vvDD-GFP). Infection of resting and dividing NIH3T3 cells with vvDD-GFP yielded reduced viral recovery compared with wild-type (WT), TK-, or VGF- viruses from resting cultures but equivalent virus recovery from dividing cultures. Eight days after nude mice were injected i.p. with 10(7) plaque-forming units (pfu) of WT, TK-, VGF-, or vvDD-GFP vaccinia virus, tissues and tumor were harvested for viral titer determination. No virus was recovered from the brains of mice injected with vvDD-GFP compared with the other viruses, which ranged from 130 to 28,000 pfu/mg protein; however, equivalent amounts were recovered from tumor. There was no toxicity from vvDD-GFP because nude mice receiving 10(8) pfu of IP vvDD-GFP lived >100 days, whereas mice receiving WT, VGF-, or TK- virus had median survivals of only 6, 17, and 29 days, respectively. Similar results were seen when 10(9) pfu of vvDD-GFP were given. Nude mice bearing s.c. murine colon adenocarcinoma (MC38) had significant tumor regression after treatment with 10(9) pfu of systemic (i.p.) vvDD-GFP compared with control (mean tumor size, 180.71 +/- 35.26 mm(3) versus 2796.79 +/- 573.20 mm(3) 12 days after injection of virus). Our data demonstrate that a TK- and VGF- mutant vaccinia virus is significantly attenuated in resting cells in vitro and demonstrates tumor-specific replication in vivo. It is a promising vector for use in tumor-directed gene therapy, given its enhanced safety profile, tumor selectivity, and the oncolytic effects after systemic delivery.

3T3 Cells↗
PubMed2001

Prognostic value of initial fasting serum gastrin levels in patients with Zollinger-Ellison syndrome.

PURPOSE: To assess the value of the initial fasting serum gastrin (FSG) at presentation in patients with Zollinger-Ellison Syndrome (ZES) in predicting primary tumor characteristics and survival. PATIENTS AND METHODS: A total of 239 patients were treated for ZES between December 1981 and September 1998, with a mean follow-up of 9.1 +/- 0.6 years. At initial evaluation, 86 patients (36%) had mild (0 to 499 pg/mL), 61 (25.5%) had moderate (500 to 1,000 pg/mL), and 92 (38.5%) had severe (> 1,000 pg/mL) elevations in FSG. Primary tumor location and size, presence of lymph node or hepatic metastases, and survival were analyzed based on the level of initial FSG. RESULTS: In patients with sporadic ZES, but not in those with multiple endocrine neoplasia type 1 (MEN-1) and ZES, there was a significant relationship between the level of initial FSG and tumor size and location of primary tumor, frequency of lymph node and liver metastases, and survival. The median 5- and 10-year survival decreased with increasing initial FSG (P <.001) in patients with sporadic ZES; MEN-1 patients lived longer than sporadic ZES patients (P =.012), and survival in this group was not associated with the level of initial FSG. Multivariate analysis showed that factors independently associated with death from disease in patients with sporadic ZES were liver metastases (P =.0001), a pancreatic site (P =.0027), and primary tumor size (P =.011) but not initial FSG (P >.30). CONCLUSION: The severity of FSG at presentation is associated with size and site of tumor and the presence of hepatic metastases, factors that are significant independent predictors of outcome. The level of FSG at presentation may be useful in planning the nature and extent of the initial evaluation and management in patients with sporadic ZES.

Adolescent↗
PubMed2001

A prospective analysis of plasma endostatin levels in colorectal cancer patients with liver metastases.

BACKGROUND: Circulating inhibitors of angiogenesis have been suggested to affect the growth of distant micrometastatic disease in patients with cancer. This study was designed to evaluate circulating endostatin levels in colorectal cancer patients with liver metastases. METHODS: Plasma samples from 30 colorectal cancer patients with liver metastases were analyzed for endostatin and vascular endothelial growth factor (VEGF) by using competitive enzyme immunoassays. Samples were compared with plasma from age- and sex-matched healthy controls; values >2 SD above the control mean were considered elevated. RESULTS: Plasma endostatin levels were significantly higher in the 30 cancer patients than controls (P < .0001) and correlated with preoperative VEGF levels (P = .0008). Eighteen patients underwent surgical treatment (liver resection, n = 10; or isolated hepatic perfusion with melphalan, n = 8). Seventeen treated patients were available for follow-up. Eight of 11 patients who progressed had elevated plasma endostatin levels at the time of progression. None of six patients who remained progression free had elevated endostatin levels at last follow-up (P = .02). CONCLUSIONS: Plasma endostatin levels are elevated in colorectal cancer patients with liver metastases and correlate with VEGF levels. Elevated endostatin levels during follow-up are associated with disease progression. Understanding the role of endogenous endostatin in cancer patients may lead to novel strategies to inhibit tumor angiogenesis.

Adult↗
PubMed2001

Factors affecting survival after complete response to isolated limb perfusion in patients with in-transit melanoma.

BACKGROUND: Isolated limb perfusion (ILP) results in complete response (CR) rates of 60% to 90% in patients with regionally advanced melanoma. Survival after a CR may be influenced by various factors, particularly out-of-field disease in iliac lymph nodes (ILN) identified during lower-extremity ILP. We examined clinical and pathological parameters, including ILN status and outcome, for patients with in-transit melanoma who had a CR to ILP. METHODS: From May 1992 to July 1997, 50 patients (16 men and 34 women; median age, 57 years) with stage IIIA or IIIAB melanoma had a CR to a 90-minute hyperthermic iliac ILP with melphalan (10 mg/L limb volume, n = 20) or melphalan and tumor necrosis factor (4-6 mg+/-200 microg interferon; n = 30). Clinical and pathological parameters were analyzed by univariate and Cox proportional hazards models to determine which were associated with survival or in-field recurrence. RESULTS: The median in-field recurrence-free survival in the cohort of 50 patients after a CR to ILP was 1.4 years, and the actuarial 5-year in-field recurrence-free survival was 30%. By univariate analysis, there was a trend for improved outcome with female sex and stage IIIA (vs. IIIAB) at initial diagnosis was associated with improved survival after a CR to ILP (P = .056 and .012, respectively). Eleven (22%) of 50 patients had positive ILNs identified and resected at ILP. The probability of overall in-field recurrence was 70% after 4 years, and there was no difference between those with or without positive ILNs; median time to in-field recurrence was 13 and 19 months, respectively (P = .62). Similarly, overall survival was not influenced by positive ILN status (median [months]: +ILN, 69 vs. -ILN, 58; P = .68). Of note, Cox models identified that the risk of death was significantly greater in those with a history of prior systemic therapy (hazard ratio: 2.67 [95% confidence interval, 1.17-6.11]; P = .02) and those with an in-transit lesion size > or =1.4 cm2 (hazard ratio, 3.12 [95% confidence interval, 1.30-7.5]; P = .011). When these two variables were combined, there was a highly significant association with shortened survival (P = .002 by log-rank test). CONCLUSIONS: These data indicate that for patients undergoing ILP and in whom positive ILNs are found and resected, ILP is justified. In addition, patients who have a CR after ILP and have a history of prior treatment or larger lesions should be considered for adjuvant systemic therapy.

Adult↗
PubMed2001

A prospective study of 2-[18F] fluoro-2-deoxy-D-glucose/positron emission tomography scan, 99mTc-labeled arcitumomab (CEA-scan), and blind second-look laparotomy for detecting colon cancer recurrence in patients with increasing carcinoembryonic antigen levels.

BACKGROUND: An increasing carcinoembryonic antigen (CEA) level in the absence of disease on imaging studies can present a diagnostic challenge. We evaluated 2-[18F] fluoro-2-deoxy-D-glucose and positron emission tomography (FDG-PET) scan and CEA scan before second-look laparotomy as a means of localizing recurrent colorectal cancer. METHODS: Patients underwent computed tomography scan, bone scan, colonoscopy, and magnetic resonance imaging, and those without evidence of disease or resectable disease in the abdomen had FDG-PET and CEA scans. At second-look laparotomy, a surgeon blinded to the results of the FDG-PET and CEA scans performed an exploration and mapped findings. A second surgeon, with knowledge of the FDG-PET and CEA scans, then explored the patient; all lesions were biopsied or resected for pathology. RESULTS: In 28 patients explored, disease was found at operation in 26 (94%). Ten had unresectable disease. FDG-PET scans predicted unresectable disease in 90% of patients. CEA scans failed to predict unresectable disease in any patient. In 16 patients found to have resectable disease or disease that could be treated with regional therapy, FDG-PET scan predicted this in 81% and CEA scan in 13%. CONCLUSIONS: FDG-PET scan can predict those patients who would likely benefit from a laparotomy. If the FDG-PET scan indicates resectable disease, laparotomy can be considered. However, if the findings predict unresectable disease or the absence of disease, the patient should pursue systemic therapy or continued observation.

Adult↗
PubMed2001

Comparison of NIS and NHIS/NIPRCS vaccination coverage estimates. National Immunization Survey. National Health Interview Survey/National Immunization Provider Record Check Study.

BACKGROUND: The National Immunization Survey (NIS) and the National Health Interview Survey (NHIS) produce national coverage estimates for children aged 19 months to 35 months. The NIS is a cost-effective, random-digit-dialing telephone survey that produces national and state-level vaccination coverage estimates. The National Immunization Provider Record Check Study (NIPRCS) is conducted in conjunction with the annual NHIS, which is a face-to-face household survey. As the NIS is a telephone survey, potential coverage bias exists as the survey excludes children living in nontelephone households. METHODS: To assess the validity of estimates of vaccine coverage from the NIS, we compared 1995 and 1996 NIS national estimates with results from the NHIS/NIPRCS for the same years. RESULTS: Both the NIS and the NHIS/NIPRCS produce similar results. CONCLUSION: The NHIS/NIPRCS supports the findings of the NIS.

Child, Preschool↗
PubMed2001

Isolated hepatic perfusion for unresectable hepatic metastases from colorectal cancer.

BACKGROUND: Unresectable colorectal liver metastases are a significant clinical problem. Isolated hepatic perfusion (IHP) is a regional treatment technique that delivers high dose chemotherapy, biologic agents, and hyperthermia via a completely isolated vascular recirculating perfusion circuit as a means of regionally treating liver tumors. This study presents our results of IHP with tumor necrosis factor (TNF) plus melphalan or IHP with melphalan alone followed by infusional floxuridine (FUDR) and leucovorin in patients with advanced or refractory unresectable hepatic colorectal metastases. METHODS: Fifty-one patients with unresectable colorectal hepatic metastases underwent a 60-minute IHP with 1.5 mg/kg melphalan and hyperthermia (39 degrees C to 40 degrees C). Thirty-two patients received IHP with 1 mg TNF with melphalan and 19 patients had IHP with melphalan alone followed by monthly hepatic intra-arterial infusional (HAI) FUDR (0.2 mg/kg/day) and leucovorin (15 mg/M(2)/day) for 14 days monthly for up to 12 months. Twenty-six patients failed 1 or more previous treatment regimens for established hepatic metastases and 27 had greater than 25% hepatic replacement (PHR) by tumor. Patients were monitored for response, toxicity, and survival. RESULTS: There was 1 perioperative death (2%), and only 2 patients (4%) had measurable perfusate leak during IHP (both less than 4%). In the 32 patients treated with IHP alone there were no detectable systemic TNF or melphalan levels during perfusion. The overall objective radiographic response rate (all partial [PR]) was 76% (38 of 50 assessable patients) with a median duration of 10.5 months (range, 2 to 21 months). Twenty-four of 31 patients (77%) had a PR after IHP alone and 14 of 19 (74%) after IHP with postperfusion HAI. Median duration of response was 8.5 months after IHP alone and 14.5 months after IHP and HAI; median survival was 16 and 27 months, respectively. There were 18 PRs in 26 patients (69%) whose prior therapy had failed and 18 PRs in 27 patients (67%) with PHR of 25 or greater. CONCLUSIONS: IHP can be performed with acceptably low morbidity and has significant antitumor activity in patients with unresectable hepatic metastases from colorectal cancer including those with refractory disease or PHR of 25 or greater. HAI appears to prolong the duration of response after IHP, and this combined treatment strategy deserves additional clinical evaluation as a therapeutic modality in this setting.

Adult↗
PubMed2001

Reoperation for hyperparathyroidism in multiple endocrine neoplasia type 1.

BACKGROUND: Patients with multiple endocrine neoplasia type 1 and hyperparathyroidism often undergo multiple operations because of inadequate initial surgery, presence of supernumerary and ectopic glands, regrowth of remnant glands, or autograft hyperfunction. Management of this patient population is complex. METHODS: From January 1975 to December 2000 we performed 94 reoperative parathyroidectomies consisting of 79 neck reexplorations, 12 autograft removals, and 3 median sternotomies in 75 patients. Data were gathered by retrospective chart review and follow-up telephone interviews. RESULTS: Excluding autograft excision, reoperative surgery was successful (normocalcemia longer than 6 months) in 91%; autograft removal was successful in only 58%. With a median follow-up of 59 months, 64% of patients are currently free from hypercalcemia, and this outcome was not influenced by the total number of glands resected. The median time to recurrent hypercalcemia was 125 months. Thirty patients received an autograft after reoperation. The complication rate for all reoperations was 12%, including permanent recurrent laryngeal nerve injury in 2 patients (2.1%). CONCLUSIONS: Reoperative parathyroidectomy in patients with multiple endocrine neoplasia type 1 was safe and successful in the majority of patients; however, recurrent hyperparathyroidism is likely to develop in most individuals beyond 10 years of follow-up. The total number of glands accounted for after reoperation is not associated with successful outcome.

Adult↗
PubMed2001

Yaba-like disease virus: an alternative replicating poxvirus vector for cancer gene therapy.

Vaccinia virus is being investigated as a replicating vector for tumor-directed gene therapy. However, the majority of cancer patients have preformed immunologic reactivity against vaccinia virus, as a result of smallpox vaccination, which may limit its use as a vector. The Yaba-like disease (YLD) virus was investigated here as an alternative, replicating poxvirus for cancer gene therapy. We have demonstrated that the YLD virus does not cross-react with vaccinia virus antibodies, and it replicates efficiently in human tumor cells. YLD virus can be expanded and purified to high titer in CV-1 cells under conditions utilized for vaccinia virus. The YLD virus RNA polymerase was able to express genes regulated by a synthetic promoter designed for use in orthopoxviruses. We sequenced the YLD virus TK gene and created a shuttle plasmid, which allowed the recombination of the green fluorescent protein (GFP) gene into the YLD virus. In a murine model of ovarian cancer, up to 38% of cells in the tumor expressed the GFP transgene 12 days after intraperitoneal virus delivery. YLD virus has favorable characteristics as a vector for cancer gene therapy, and this potential should be explored further.

Animals↗
PubMed2001

Role of tumor necrosis factor on toxicity and cytokine production after isolated hepatic perfusion.

PURPOSE: Isolated limb or liver perfusion with tumor necrosis factor (TNF) and melphalan results in regression of advanced cancers in the majority of treated patients. However, the contribution of TNF to the efficacy of isolation perfusion with melphalan has not been demonstrated conclusively in random assignment trials. Furthermore, TNF is an inflammatory cytokine and may be associated with significant systemic and regional toxicity. This study was conducted to characterize the toxicity and secondary cytokine production attributable to TNF by comparing these parameters in patients undergoing isolated hepatic perfusion (IHP) using melphalan with or without TNF. EXPERIMENTAL DESIGN: Thirty-two patients with unresectable colorectal cancer confined to the liver underwent a 60-min hyperthermic IHP using 1.5 mg/kg melphalan alone (n = 17) or with 1.0 mg of TNF (n = 15) with inflow via the gastroduodenal artery and outflow via an isolated segment of inferior vena cava. Complete vascular isolation was confirmed using the I-131 radiolabeled albumin-monitoring technique. Post-IHP parameters of hepatic and systemic toxicity and cytokine levels [TNF, interleukin (IL)-6 and IL-8] in perfusate and serum were measured. RESULTS: Levels of IL-6 and IL-8 in perfusate at the end of the 60-min IHP were significantly higher in TNF-treated patients (P < or = 0.001). Peak systemic IL-6 and IL-8 levels post-IHP were also significantly higher in TNF-treated compared with non-TNF-treated patients (P < 0.0001) by 28- and 268-fold, respectively. The peak levels of these cytokines were associated with significantly lower systolic blood pressure and higher heart rate and mean pulmonary artery blood pressure in TNF-treated patients during the first 48 h post-IHP (P < or = 0.03). Serum bilirubin levels were significantly higher (P = 0.017) and platelets lower (P = 0.03) in TNF-treated compared with non-TNF-treated patients. However, elevations in aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase were not significantly different between groups and returned toward baseline within 1 week after IHP. CONCLUSIONS: Addition of TNF to melphalan during IHP results in significant differences in post-IHP production of IL-6 and IL-8 with associated changes in mean arterial blood pressure and greater regional toxicity, as reflected in higher levels of serum bilirubin. However, these measurable differences were transient and did not appear to be of major clinical consequence. Prior to its routine use, the benefit of TNF in isolation perfusion should be demonstrated in random assignment trials.

Adult↗
PubMed2000

Antiangiogenic gene therapy of cancer utilizing a recombinant adenovirus to elevate systemic endostatin levels in mice.

Gene therapy represents a possible alternative to the chronic delivery of recombinant antiangiogenic proteins to cancer patients. Inducing normal host tissues to produce high circulating levels of these proteins may be more effective than targeting antiangiogenic genes to tumor tissue specifically. Previously reported gene therapy approaches in mice have achieved peak circulating endostatin levels of 8-33 ng/ml. Here we report plasma endostatin levels of 1770 ng/ml after administration of a recombinant adenovirus. Growth of MC38 adenocarcinoma, which is relatively resistant to adenoviral infection, was inhibited by 40%. These findings encourage gene delivery approaches that use the host as a "factory" to produce high circulating levels of antiangiogenic agents.

Adenoviridae↗
PubMed2000

Vaccinia as a vector for tumor-directed gene therapy: biodistribution of a thymidine kinase-deleted mutant.

Tumor-directed gene therapy, such as "suicide gene" therapy, requires high levels of gene expression in a high percentage of tumor cells in vivo to be effective. Current vector strategies have been ineffective in achieving these goals. This report introduces the attenuated (thymidine kinase (TK)-negative) replication-competent vaccinia virus (VV) as a potential vector for tumor-directed gene therapy by studying the biodistribution of VV in animal tumor models. A TK-deleted recombinant VV (Western Reserve strain) expressing luciferase on a synthetic promoter was constructed. Luciferase activity was measured in vitro after transduction of a variety of human and murine tumor cell lines and in vivo after intraperitoneal (i.p.) delivery in C57BL/6 mice with 7-day i.p. tumors (10(6) MC-38 cells). Three other in vivo tumor models were examined for tumor-specific gene expression after intravenous delivery of VV (human melanoma in nude mice, adenocarcinoma liver metastasis in immunocompetent mice, and subcutaneous sarcoma in the rat). In addition, a replication-incompetent vaccinia (1 microg of psoralen and ultraviolet light, 365 nm, 4 minutes) was tested in vitro and in vivo and compared with active virus. Luciferase activity in i.p. tumors at 4 days after i.p. injection of VV was >7000-fold higher than lung, >3000-fold higher than liver, and >250-fold higher than ovary. In addition, intravenous injection of VV resulted in markedly higher tumor luciferase activity compared with any other organ in every model tested (up to 188,000-fold higher than liver and 77,000-fold higher than lung). Inactivation of the virus resulted in negligible gene expression in vivo. In summary, VV has a high transduction efficiency in tumor cells with high levels of gene expression. The results suggest a selective in vivo replication of TK-deleted VV in tumor cells. Replication competent, TK-deleted VV appears to be an ideal vector for testing the in vivo delivery of toxic genes to tumor cells.

Animals↗
PubMed2000

Complex interactions between the replicating oncolytic effect and the enzyme/prodrug effect of vaccinia-mediated tumor regression.

Replicating viruses for cancer gene therapy have beneficial antitumor effects, however, in the setting of an enzyme/prodrug system, the interactions between these viruses and the activated agents are complex. A replicating vaccinia virus expressing the cytosine deaminase gene (VVCD), which converts the prodrug 5-FC into 5-FU, was characterized in vitro and in vivo for its antitumor effects and pathogenicity. Replicating VVCD (+/-5-FC) at various MOIs was used to infect MC38 murine colon adenocarcinoma cells. At high MOIs (>0.1) virus alone was able to kill the majority (65-90%) of cells by day 5 with no additional benefit from prodrug. At low MOIs only the effect of prodrug is seen. Cell lysates demonstrated 300-fold reduced viral recovery from cells treated with both VVCD and 5-FC compared with controls treated with virus alone. Nude mice bearing subcutaneous MC38 tumors were injected with VVCD (or control) and treated with 5FC or control. Mice injected with VVCD (with or without 5FC treatment) had smaller tumors than the controls, suggesting that replicating vaccinia alone is cytotoxic to tumors in vivo. The addition of 5-FC improved the antitumor response when a low dose of virus was injected into tumors. Also, compared with mice that received virus alone, those that received VVCD and 5FC had significantly prolonged survival from virus-mediated death. In conclusion, the addition of an enzyme/prodrug system to a replicating virus can improve the antitumor response and decrease viral pathogenicity. Gene Therapy (2000) 7, 1217-1223.

Adenocarcinoma↗
PubMed2000

Ultrasound and sestamibi scan as the only preoperative imaging tests in reoperation for parathyroid adenomas.

BACKGROUND: In an effort to determine an efficient algorithm for the evaluation of patients with parathyroid adenomas in the reoperative setting, we explored the combination of using ultrasound scans (US) and sestamibi scintigraphy as the only preoperative imaging tests. METHODS: We analyzed the outcomes of 62 consecutive patients who were treated between January 1995 and May 1999 and who were referred for persistent primary hyperparathyroidism after initial surgical exploration, at which time no abnormal parathyroid glands had been found. Although all patients underwent US, computed tomography scan, magnetic resonance imaging, and sestamibi scan, we analyzed the success of localization and reoperation using only the results of US and sestamibi scan. RESULTS: Sixty-one patients (98%) underwent curative reoperations. The sensitivity, positive predictive value, and accuracy for US were 90%, 86%, and 84%, respectively; the corresponding values for sestamibi imaging were 78%, 94%, and 74%, respectively. In 58 of 62 cases (94%) preoperative US and/or sestamibi scan accurately identified the adenoma. In 3 patients for whom combined US and sestamibi scan were inaccurate, 1 adenoma was found by intraoperative US in the strap muscle; 1 adenoma was found by blind cervical thymectomy, and 1 adenoma was found by planned sternotomy that was based on computed tomography findings. CONCLUSIONS: This study supports an algorithm of obtaining US and sestamibi scan as the initial and perhaps only preoperative localization tests for patients with primary hyperparathyroidism after failed operation, at which time no abnormal glands had been found.

Adenoma↗
PubMed2000

Clinical and genetic analysis of patients with pancreatic neuroendocrine tumors associated with von Hippel-Lindau disease.

BACKGROUND: Patients with von Hippel-Lindau disease (VHL) may develop pancreatic neuroendocrine tumors (PNETs), which can behave in a malignant fashion. We prospectively evaluated size criteria for resection of lesions and the role of genotype/phenotype analysis of germline VHL mutations in predicting clinical course. METHODS: From December 1988 through December 1999 we screened 389 patients with VHL. The diagnosis of PNET was made by pathologic analysis of tissues or by radiographic appearance. Germline mutations were determined by quantitative Southern blotting, fluorescence in situ hybridization and complete gene sequencing. RESULTS: Forty-four patients with PNETs have been identified; 25 have undergone surgical resection, 5 had metastatic disease, and 14 are being monitored. No patient who has undergone resection based on tumor size criteria has developed metastases. Patients with PNETs were more likely to have missense mutations (58%), and 4 of 5 patients (80%) with metastatic disease had mutations in exon 3 compared with 18 of 39 (46%) patients without metastatic disease. CONCLUSIONS: Imaging for detection and surgical resection based on size criteria have resulted in the successful management of VHL patients with PNETs. Analysis of germline mutations may help identify patients at risk for PNET and which patients may benefit from surgical intervention.

Adolescent↗
PubMed2000

Forty-eight-hour fast: the diagnostic test for insulinoma.

Insulinoma causes fasting hypoglycemia due to inappropriate insulin secretion. Its diagnosis is based on demonstrating Whipple's triad during a supervised 72-h fast. For 75 yr, the 72-h fast has been the cornerstone for the diagnosis; however, it has never been critically assessed using newer assays for insulin, C peptide, and proinsulin. Thus, the aim of the current study is to assess the need for a full 72-h fast for the diagnosis of insulinoma. Patients with suspected hypoglycemia with documented glucose concentrations below 45 mg/dL were admitted to the NIH. Data obtained during the supervised fast of patients with pathologically proven insulinoma over a 30-yr period (1970-2000) were reviewed. We identified 127 patients with insulinoma. The average age of patients was 42.7 +/- 15.9 yr, with a predominance of females (62%). 107 patients had a benign tumor, 20 had malignant insulinoma, and 15 patients had multiple endocrine neoplasia type 1. The fast was terminated due to hypoglycemia in 44 patients (42.5%) by 12 h, 85 patients (66.9%) by 24 h, and 120 (94.5%) by 48 h. Seven patients fasted beyond 48 h despite subtle neuroglycopenic symptoms and glucose and insulin concentrations diagnostic of insulinoma. Immunoreactive proinsulin was elevated at the beginning of the fast in 90% of 42 patients. Proinsulin in noninsulinoma, in contrast to insulinoma, patients is usually suppressible; therefore, samples taken in the suppressed state have the greatest diagnostic value. We conclude that with the current available insulin and proinsulin assays, the diagnosis of insulinoma can be made within 48 h. Thus, the 48-h fast should replace the 72-h fast in textbooks and hospital protocols as the new diagnostic standard.

Adolescent↗
PubMed2000

Current status of isolated hepatic perfusion with or without tumor necrosis factor for the treatment of unresectable cancers confined to liver.

Metastatic or primary unresectable cancers confined to the liver are the sole or life-limiting component of disease for many patients with colorectal cancer, ocular melanoma, neuroendocrine tumors or primary colangio- or hepatocellular carcinomas. A number of regional treatment strategies including infusional chemotherapy and local ablative therapy are under clinical development and attest to the difficulty in adequately treating this condition. Isolated hepatic perfusion (IHP) was first clinically applied over 40 years ago, but because of its technical complexity, the attendant potential morbidity, and the lack of documented efficacy, it has not gained widespread application. In light of the remarkable antitumor activity with isolated limb perfusion with tumor necrosis factor (TNF) and melphalan in patients with unresectable extremity sarcoma or in transit melanoma, this regimen has been administered via IHP at several centers worldwide for unresectable liver cancers. IHP with TNF and melphalan can result in significant regression of advanced refractory cancers confined to the liver and, with additional clinical development, will most likely be a more routinely considered option for patients with this condition.

Antineoplastic Agents↗