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D Coit

Publications and source records attributed to D Coit.

At least 19 recordsLinked to original sources
PubMed2006

Current treatment options and biology of peritoneal mesothelioma: meeting summary of the first NIH peritoneal mesothelioma conference.

Peritoneal mesothelioma is a rare cancer of the peritoneum with about 250 new cases diagnosed each year in the United States. It is the second most common site for mesothelioma development and accounts for 10-20% of all mesotheliomas diagnosed in the United States. A meeting sponsored by the NIH Office of Rare Diseases was held in Bethesda, Maryland on September 13 and 14, 2004. The objective of this meeting was to review the epidemiology, biology and current surgical and medical management of peritoneal mesothelioma. In addition, the meeting also discussed clinical and pre-clinical evaluation of novel treatments for mesothelioma as well as ongoing laboratory research to better understand this disease. This report summarizes the proceedings of the meeting as well as directions for future clinical and basic research.

Clinical Trials as Topic↗
PubMed2005

Initial experience with hand-assisted laparoscopic distal pancreatectomy.

BACKGROUND: Hand-assisted laparoscopic distal pancreatectomy, with or without splenectomy, is gradually gaining acceptance, although its ultimate benefit is yet to be confirmed. This study aimed to report our initial experience with hand-assisted laparoscopic distal pancreatectomy. METHODS: A retrospective review of a prospectively collected database including 17 patients during the period 2002-2004 was conducted. The median age was 60 years (range, 29-85 years), and the female-to-male ratio was 13:4. The preoperative diagnoses included benign and malignant conditions. Besides two to three ports, a hand port was placed in the upper midline to aid in dissection. The pancreas was divided with a stapler in all the patients, and drains were placed in 10 patients (70%). RESULTS: One patient was found to be unresectable because of celiac artery involvement, and 2 of the remaining 16 patients underwent conversion to an open procedure. The median operating time was 196 min (range, 128-235 min). The mean tumor size was 4 cm (range, 2-7 cm), and the estimated blood loss was 125 ml (range, 50-1,250 ml). The median time to resumption of a regular diet was 3.5 days (range, 2-9 days), and the time to conversion to oral pain medications was 3 days (range, 2-9 days). The length of hospital stay was 5.5 days (range, 4-18 days), with a majority of the patients (11 patients, 78%) staying less than 7 days. There were no mortalities. The overall postoperative morbidity rate was 25%, and the morbidities consisted of pancreatic leak/fistula (2 patients, 14%) and fever (1 patient). The margins were negative in 10 (76%) of the relevant 13 patients. At a median follow-up period of 3.8 months (range, 5-14 months), 11 (84%) of 13 patients had no evidence of disease recurrence. CONCLUSIONS: The minimally invasive approach to pancreatic disease is safe and technically feasible. Further large studies with longer follow-up periods are necessary to determine the role of laparoscopic surgery in the management of pancreatic disease.

Adult↗
PubMed2004

Estimating the relative risk of developing melanoma in INK4A carriers.

Estimation of the relative risk of cancer due to rare germline mutations using population-based epidemiological techniques is challenging, since studies with very large numbers of subjects are required. In this pilot study using a novel study design, we evaluated the role of INK4A mutations in melanoma by comparing patients with multiple primary melanomas to those with single primaries. Patients were ascertained from the Surgery and Dermatology Clinics at Memorial Sloan-Kettering Cancer Center and at the Yale University Pigmented Lesion Clinic. Subjects completed a questionnaire covering risk factors for melanoma and were tested for INK4A mutations. Five (8%) of 65 patients with multiple primaries had a mutation, compared with none of 88 patients with single primaries (P=0.03). Examination of other factors, such as number of nevi on the arms of the patients, fair skin, hair and eye colour, and other phenotypic characteristics associated with the risk of melanoma, demonstrates that these factors exhibit higher prevalence in the multiple primary cases than in the single primaries. These results provide evidence of the utility of the new study design in evaluating the impact of rare but highly penetrant cancer risk factors.

Adolescent↗
PubMed2002

Randomized, placebo-controlled trial of dietary supplementation of alpha-tocopherol on mutagen sensitivity levels in melanoma patients: a pilot trial.

We evaluated the effects of vitamin E (dl-alpha-tocopherol) on mutagen sensitivity levels in a randomized placebo-controlled pilot trial. In brief, a dietary supplement of 1000 mg/day vitamin E or a placebo was randomly administered for 3 months to melanoma outpatients clinically free of the disease. Plasma vitamin E and mutagen sensitivity levels were measured at baseline and at the end of the trial after 3 months. At baseline, we found no significant differences in plasma vitamin E and mutagen sensitivity levels between the two groups. We also measured dietary intake at baseline and found dietary vitamin E to be a poor predictor of plasma levels of vitamin E. After 3 months of supplementation, we found that plasma levels of alpha-tocopherol increased significantly (P = 0.0005) in the vitamin E compared to the placebo group. We also found a non-significant, but consistent decrease in plasma gamma-tocopherol concentrations in the vitamin E supplemented compared to the placebo group. We did not find any significant difference between the vitamin E and placebo groups in mutagen sensitivity levels either at baseline or after 3 months of supplementation. We conclude that short term vitamin E supplementation, although it causes increased blood levels of alpha-tocopherol, does not provide protection against bleomycin-induced chromosome damage.

Adult↗
PubMed2001

The search for level I evidence in solid-tumor oncology.

BACKGROUND: We have developed a method to identify, filter, review, and distribute the published level I evidence for solid tumor oncology. METHODS: A standardized MEDLINE search identified prospective randomized controlled trials (PRCTs) in solid tumor oncology. Only PRCTs with therapeutic end points were included. All references were reviewed by a surgical oncology fellow in consultation with experts in the field. The full citations were imported into a comprehensive database. Data on statistical methods according to the Consolidated Standard of Reporting Trials statement were tabulated along with reviewer's comments. A designation of Ia was given to articles that were well designed and significant contributions to their field. The database powers a dynamic, easily searchable Web site on our intranet and is available in personal digital assistant (PDA) format. RESULTS: By using standard search criteria, only .03% of the 11 million articles listed in MEDLINE are PRCTs concerning therapy for solid organ malignancies. Approximately 14% of reviewed articles were given a designation of Ia. Having comprehensive data readily available with intranet access or PDAs during conferences enhances their educational value and specificity. CONCLUSIONS: We have developed an exciting tool that uses a highly trained filter to screen and record the medical data available to the clinician. This information has been made available and portable by using the Internet and PDAs.

Databases as Topic↗
PubMed2001

Intrahepatic genetic inoculation of hepatitis C virus RNA confers cross-protective immunity.

Naturally occurring hepatitis C virus (HCV) infection has long been thought to induce a weak immunity which is insufficient to protect an individual from subsequent infections and has cast doubt on the ability to develop effective vaccines. A series of intrahepatic genetic inoculations (IHGI) with type 1a HCV RNA were performed in a chimpanzee to determine whether a form of genetic immunization might stimulate protective immunity. We demonstrate that the chimpanzee not only developed protective immunity to the homologous type 1a RNA after rechallenge by IHGI but was also protected from chronic HCV infection after sequential rechallenge with 100 50% chimpanzee infectious doses of a heterologous type 1a (H77) and 1b (HC-J4) whole-virus inoculum. These results offer encouragement to pursue the development of HCV vaccines.

Amino Acid Sequence↗
PubMed2000

Hepatitis B virus e antigen specific epitopes and limitations of commercial anti-HBe immunoassays.

Current commercial hepatitis B virus (HBV) anti-HBe immunoassays are designed so that anti-HBe is detectable only in the absence of excess HBeAg. Recently, with the use of direct anti-HBe assays, anti-HBe was detected in individuals who had been seropositive for several years for HBeAg [Maruyama et al. (1993) J. Clin. Invest. 91:2586-2595]. Although anti-HBe seroconversion does not necessarily indicate subsequent HBeAg clearance, the ability to detect earlier anti-HBe seroconversion could have clinical significance for monitoring patients undergoing HBV immunotherapy (e.g., alpha interferon therapy). Because the HBeAg and the HBcAg share 149 amino acids, an anti-HBe assay must distinguish anti-HBe from anti-HBc antibodies. Although the HBV HBeAg and HBcAg display distinct immunogenic determinants, much remains unknown regarding the complete epitope spectrum specific to each antigen. The goal of this study was 3-fold. The first objective was to identify HBeAg specific linear epitopes. The second objective was to design an anti-HBe immunoassay capable of detecting anti-HBe specific antibody in the presence of excess HBeAg. The third objective was to characterize early anti-HBe seroconversion antibodies. The major linear epitope residing in the HBeAg amino acid sequence was mapped and 2 novel minor epitopes (delta, gamma) which appear to be HBeAg specific have been identified. An anti-HBe immunoassay capable of detecting anti-HBe specific antibody in the presence of excess HBeAg was designed. Finally, it was found that early anti-HBe seroconversion antibodies appear to be conformational, whereas later seroconversion, more typically associated with the clearance of HBeAg, is characterized by the presence of antibodies to the linear HBeAg epitopes.

Animals↗
PubMed1999

Use of a novel hepatitis C virus (HCV) major-epitope chimeric polypeptide for diagnosis of HCV infection.

The genome of hepatitis C virus (HCV) consists of seven functional regions: the core, E1, E2/NS1, NS2, NS3, NS4, and NS5 regions. The U. S. Food and Drug Administration-licensed 2.0G immunoassay for the detection of anti-HCV uses proteins from the core, NS3, and NS4 regions (McHutchinson et al., Hepatology 15:19-25, 1992). The 3.0G enzyme-linked immunosorbent assay includes the protein from the NS5 region (Uyttendaele et al., Vox Sang. 66:122-129, 1994). The necessity of detecting antibodies to viral envelope proteins (E1 and E2) and to different genotype samples has been demonstrated previously (Chien et al., Lancet 342:933, 1993; Lok et al., Hepatology 18:497-502, 1993). In this study we have attempted to improve the sensitivity of the anti-HCV assay by developing a single multiple-epitope fusion antigen (MEFA; MEFA-6) which incorporates all of the major immunodominant epitopes from the seven functional regions of the HCV genome. A nucleic acid sequence consisting of proteins from the viral core, E1, E2, NS3, NS4, and NS5 regions and different subtype-specific regions of the NS4 region was constructed, cloned, and expressed in yeast. The epitopes present on this antigen can be detected by epitope-specific monoclonal and polyclonal antibodies. In a competition assay, the MEFA-6 protein competed with 83 to 96% of genotype-specific antibodies from HCV genotype-specific peptides. This recombinant antigen was subsequently used to design an anti-HCV chemiluminescent immunoassay. We designed our assay using a monoclonal anti-human immunoglobulin G antibody bound to the solid phase. Because MEFA-6 is fused with human superoxide dismutase (h-SOD), we used an anti-human superoxide dismutase, dimethyl acridinium ester-labeled monoclonal antibody for detection. Our results indicate that MEFA-6 exposes all of the major immunogenic epitopes. Its excellent sensitivity and specificity for the detection of clinical seroconversion are demonstrated by this assay.

Antigens, Viral↗
PubMed1998

Prognostic significance of peripheral blood and bone marrow tyrosinase messenger RNA in malignant melanoma.

The objectives of this study were to evaluate the prognostic significance of reverse transcription PCR (RT-PCR) detection of tyrosinase mRNA in the peripheral blood (PB) and bone marrow (BM) of patients with stage II-IV malignant melanoma (MM). Seventy-three PB samples and 109 BM aspirates from 123 assessable patients with stage II-IV MM were analyzed for tyrosinase mRNA using nested RT-PCR. Twenty-five controls without MM were also evaluated. The RT-PCR results were correlated with overall survival (OS) and clinical stage. Overall, 23 of the 123 patients with MM (19%) had tyrosinase mRNA in their blood and/or BM. RT-PCR positivity was present in the PB of 9 of 73 patients (12%), whereas 18 of 109 (16.5%) had tyrosinase mRNA in their BM. All controls were tyrosinase PCR negative. There was no correlation between RT-PCR results and clinical stage. Within stage II, BM PCR-positive patients had a shorter median survival (24 months) than BM PCR-negative individuals (median not reached), with a P approaching significance (P = 0.06). There was a statistically significant correlation between blood PCR positivity and decreased overall survival (P = 0.03) in all patients. Blood PCR positivity was associated with a significantly decreased OS in stage II and III (P = 0.01 and 0.02, respectively) and was not a predictor of OS in stage IV. In multivariate analysis, blood RT-PCR for tyrosinase mRNA was found to be an independent predictor of survival (P = 0.03; risk ratio, 2.87). RT-PCR can specifically detect tyrosinase mRNA in the PB and BM of patients with MM. Blood RT-PCR is an independent predictor of overall survival in stage II-III MM. Additional studies are needed to define the potential role of this assay in the management of patients with advanced melanoma.

Adult↗
PubMed1997

Signal transduction mediated by the truncated trkB receptor isoforms, trkB.T1 and trkB.T2.

The trkB family of transmembrane proteins serves as receptors for BDNF and NT-4/5. The family is composed of a tyrosine kinase-containing isoform as well as several alternatively spliced "truncated receptors" with identical extracellular ligand-binding domains but very small intracellular domains. The two best-characterized truncated trkB receptors, designated as trkB.T1 and trkB.T2, contain intracellular domains of only 23 and 21 amino acids, respectively. Although it is known that the tyrosine kinase isoform (trkB.FL) is capable of initiating BDNF and NT-4/5-induced signal transduction, the functional role or roles of the truncated receptors remain enigmatic. At the same time, the potential importance of the truncated receptors in the development, maintenance, and regeneration of the nervous system has been highlighted by recent developmental and injury paradigm investigations. Here we have used trkB cDNA transfected cell lines to demonstrate that both trkB.T1 and trkB.T2 are capable of mediating BDNF-induced signal transduction. More specifically, BDNF activation of either trkB.T1 or trkB.T2 increases the rate of acidic metabolite release from the cell, a common physiological consequence of many signaling pathways. Further, these trkB.T1- and trkB. T2-mediated changes occur with kinetics distinct from changes mediated by trkB.FL, suggesting the participation of at least some unique rate-limiting component or components. Mutational analysis demonstrates that the isoform-specific sequences within the intracellular domains of each receptor are essential for signaling capability. Finally, inhibitor studies suggest that kinases are likely to be involved in the trkB.T1 and trkB.T2 signaling pathways.

Alternative Splicing↗
PubMed1994

Prospective evaluation of unilateral adrenal masses in patients with operable non-small-cell lung cancer. Impact of magnetic resonance imaging.

UNLABELLED: We designed a prospective study to evaluate the accuracy of magnetic resonance imaging in distinguishing a benign from a malignant adrenal mass in patients with otherwise operable non-small-cell lung cancer. METHODS: Potentially operable non-small-cell lung cancer was prospectively staged. If a unilateral adrenal mass was found by computed tomographic scanning, respiratory compensated and cardiac gated thin section magnetic resonance imaging of the adrenal glands was done. One radiologist interpreted the magnetic resonance imaging scan blinded and, on the basis of the relative signal strengths of the T1- and T2-weighted images, judged whether the adrenal mass was benign or malignant. The patients then underwent a percutaneous needle biopsy of the adrenal mass, if technically feasible. If the result of the needle biopsy was nondiagnostic or if the biopsy was not feasible, an adrenalectomy through a posterior approach was performed. RESULTS: Twenty-seven patients with a unilateral adrenal mass entered the study-11 men and 16 women whose ages ranged from 42 to 75 years (median 58 years). Four patients had epidermoid and 23 adenocarcinoma of the lung. The clinical locoregional stage was I in 9, II in 1, IIIA in 16, and IIIB in 1. Twenty-five completed the magnetic resonance imaging procedure. Five adrenal masses (19%) were metastatic non-small-cell lung cancer (adenocarcinoma = 4, epidermoid = 1); 22 masses (81%) were benign (adenoma = 20, hyperplasia = 2). There were no significant differences in age, sex, histologic type, or locoregional stage between those with a benign versus a malignant mass. However, the malignant masses were significantly larger (3.8 +/- 1.9 cm; range 2.5 to 7.1; median 3.1) than the benign masses (2.0 +/- 0.4 cm, range 1.2 to 2.8; median 2.0) (p < 0.001). Among those having magnetic resonance imaging (n = 25), the technique correctly predicted a malignant mass in the four patients with a histologically confirmed metastasis from non-small-cell lung cancer. However, among the 21 histologically benign masses, the magnetic resonance imaging was interpreted as benign in 5, malignant in 14, and indeterminate in 2. Therefore, although the false-negative rate was 0%, the false-positive rate was 67%. CONCLUSION: Most adrenal masses in patients with otherwise operable non-small-cell lung cancer are benign. Currently available magnetic resonance imaging methods cannot replace biopsy.

Adrenal Gland Diseases↗
PubMed1993

A prospective, randomized evaluation of the effect of silver impregnated subcutaneous cuffs for preventing tunneled chronic venous access catheter infections in cancer patients.

OBJECTIVE: This study was performed to evaluate the effect of a silver-impregnated cuff on the incidence of catheter-related bacteremia/fungemia or tunnel tract infection in cancer patients with chronic dual-lumen tunneled venous access catheters. SUMMARY BACKGROUND DATA: Infection is a frequent and potentially life-threatening complication of tunneled chronic cuffed silastic central venous access catheters in cancer patients. Recent experience with antimicrobial silver-impregnated cuffs placed on nontunneled percutaneously inserted central venous catheters suggests that such a cuff may render the catheter less prone to infection. METHODS: The authors prospectively randomized 200 cancer patients to receive either a dual-lumen 10 French tunneled cuffed silastic central venous access catheter or the same catheter with a second more proximal subcutaneous silver-impregnated cuff. All patients then were followed prospectively for infectious morbidity until the device was removed or the patient died. RESULTS: The hazard rate for infection/day (95% confidence limits) was 0.0022 (0.0015 to 0.0030) for standard catheters compared with 0.0027 (0.0019 to 0.0037) for catheters with silver-impregnated cuffs (p = not significant). Regression analysis of infection-free interval of both catheter types shows no difference over the lifetime of catheter as well as the over the first 48 days after insertion. CONCLUSIONS: The study indicated no effect of a silver-impregnated cuff in decreasing the incidence of catheter-related bacteremias/fungemias, tunnel infections, or the spectrum of causative microorganisms involved in cancer patients with tunneled chronic venous access catheters.

Adolescent↗
PubMed1992

A phase II trial of biochemical modulation using N-phosphonacetyl-L-aspartate, high-dose methotrexate, high-dose 5-fluorouracil, and leucovorin in patients with adenocarcinoma of unknown primary site.

BACKGROUND: 5-Fluorouracil (5-FU) has modest activity as a single agent in a number of human adenocarcinomas. The technique of biochemical modulation has been used preclinically to increase the activity of 5-FU. METHODS: With doses based on a Phase I study, the authors performed a Phase II trial in patients with advanced metastatic adenocarcinoma of an unknown primary site using N-phosphonacetyl-l-aspartate (PALA), methotrexate (MTX), 5-FU, and leucovorin. In some patients, 5-phosphoriosyl-l-pyrophosphate (PRPP) and uridine triphosphate (UTP) metabolite pools were assayed before and after PALA and MTX to assess metabolite pool shifts. RESULTS: Twenty-one patients were treated in this Phase II trial. Toxicity was tolerable. Biopsy specimens of tumor tissue showed increases in PRPP and decreases in UTP levels in two of three and three of four patients, respectively. However, only one objective response was seen, which is not different from that expected with 5-FU alone. CONCLUSIONS: Expected PRPP and UTP metabolite pool shifts were seen when biochemical modulation was performed with these drugs according to this schedule. Because toxicity was mild, more intense dose schedules of 5-FU are planned for future studies.

Adenocarcinoma↗
PubMed1992

Extraneural cysticercosis presenting as a tumor in a seronegative patient.

A case of cysticercosis involving only the sternocleidomastoid muscle of an otherwise-healthy pregnant woman is presented. An enzyme-linked immunoelectrotransfer blot assay for cysticercosis was nonreactive. The clinical features of extraneural cysticercosis are reviewed with special attention to musculocutaneous involvement. The results of serological tests for such patients may not be positive and histopathology remains the only reliable method for confirming the diagnosis of cysticercosis.

Adult↗
PubMed1991

Genetic organization and diversity of the hepatitis C virus.

The nucleotide sequence of the RNA genome of the human hepatitis C virus (HCV) has been determined from overlapping cDNA clones. The sequence (9379 nucleotides) has a single large open reading frame that could encode a viral polyprotein precursor of 3011 amino acids. While there as little overall amino acid and nucleotide sequence homology with other viruses, the 5' HCV nucleotide sequence upstream of this large open reading frame has substantial similarity to the 5' termini of pestiviral genomes. The polyprotein also has significant sequence similarity to helicases encoded by animal pestiviruses, plant potyviruses, and human flaviviruses, and it contains sequence motifs widely conserved among viral replicases and trypsin-like proteases. A basic, presumed nucleocapsid domain is located at the N terminus upstream of a region containing numerous potential N-linked glycosylation sites. These HCV domains are located in the same relative position as observed in the pestiviruses and flaviviruses and the hydrophobic profiles of all three viral polyproteins are similar. These combined data indicate that HCV is an unusual virus that is most related to the pestiviruses. Significant genome diversity is apparent within the putative 5' structural gene region of different HCV isolates, suggesting the presence of closely related but distinct viral genotypes.

Amino Acid Sequence↗