PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Digestive System Neoplasms”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMed1999

O6-benzylguanine: a clinical trial establishing the biochemical modulatory dose in tumor tissue for alkyltransferase-directed DNA repair.

Early phase evaluation of anticancer drugs has traditionally used toxicity (usually hematological) rather than efficacy end points to establish appropriate dosing schedules. To establish a biochemical efficacy end point for overcoming alkylguanine DNA alkyltransferase (AGT)-mediated tumor cell resistance to 1,3-bis(2-chloroethyl)-1-nitrosourea, we performed a novel dose escalation clinical trial for the AGT-depleting agent O6-benzylguanine (BG). The dose of BG required to deplete AGT to undetectable levels (BMD(T)) in sequential computed tomography-guided tumor tissue biopsies before BG and 18 h after BG was determined. Thirty patients received doses of BG ranging from 10 to 120 mg/m2. In tumor tissue, AGT depletion >86% of baseline was demonstrated at all doses tested. Residual tumor AGT activity, present 18 h after BG doses of 10-80 mg/m2, was eliminated at the 120 mg/m2 dose and is thus the BMD(T) of BG. BG pharmacokinetics are characterized by the rapid, dose-independent clearance of BG from plasma Metabolism of BG to its biologically active metabolite, 8-oxo-benzylguanine (8-oxo-BG), was found. The t(1/2) of 8-oxo-BG is longer than BG. Plasma concentrations of 8-oxo-BG well above 200 ng/ml 18 h after the end of the BG infusion were observed at the highest dose levels tested and appeared to correlate with depletion of AGT activity to undetectable levels in tumor tissue. AGT activity in peripheral blood mononuclear cells at baseline did not correlate with tumor tissue AGT activity. Depletion of AGT activity to undetectable levels in peripheral blood mononuclear cells occurred at lower doses and was not a reliable predictor for tumor tissue depletion. No serious side effects were observed with administration of BG alone or in combination with 13 mg/m2 1,3-bis(2-chloroethyl)-1-nitrosourea. This is the first clinical study in which biochemical analyses from pre- and posttreatment tumor biopsies have been used as an efficacy end point for the clinical development of an anticancer agent. From our tumor tissue biopsy data, we have established that a BG dose of 120 mg/m2 infused over 1 h should be used in Phase II clinical trials.

Adult↗
PubMed1999

The wallstent endoprosthesis.

The Wallstent endoprosthesis is the most widely used self-expanding metal stent for treating digestive disease worldwide. This article presents detailed metallurgical and physical information on the Wallstent endoprosthesis, and addresses implications for its clinical use. Detailed product information provides technical insight into the implantable stent and associated delivery systems. Current worldwide product indications and configurations are discussed, as well as insight into new products in clinical evaluation.

Coated Materials, Biocompatible↗
PubMed1999

High inter- and intrapatient variation in 5-fluorouracil plasma concentrations during a prolonged drug infusion.

The purpose of the study was to examine inter- and intrapatient variation in 5-fluorouracil (5-FU) plasma concentrations in adult cancer patients receiving a 3-day drug infusion. Fourteen patients received 1266 mg/m2 N-(phosphonacetyl)-L-aspartate (PALA) infused i.v. over 15 min on day 1, followed immediately by a loading dose of 500 mg/m2 calcium leucovorin over 30 min. Then a prolonged infusion of leucovorin at 500 mg/m2/day and 5-FU at 1750 mg/m2/day was administered as either a constant rate or as a circadian infusion over 72 h. During constant rate infusions, 5-FU concentrations within individuals varied by 1.7-fold, but no uniform time of peak or trough concentration was observed. Transformation of these data by setting the time of peak to 0 h and by expressing concentrations as the percentage of the 24-h mean value revealed a nonrandom distribution of the time from peak to trough with a median time of 12 h (P = 0.027). These transformed data were also successfully fit to a circadian cosinor function (P < 0.001). During multiple constant rate 5-FU infusions, the intrapatient variability was high; the times of peak 5-FU concentration occurred at the same approximate sampling time 43% of the time, and troughs coincided 17% of the time. No difference in clinical toxicity was observed when matched constant rate and circadian infusions of 5-FU were compared. High inter- and intrapatient variability exists in 5-FU plasma concentrations in adult cancer patients during constant rate infusions with no evidence of a consistent circadian rhythm in untransformed data.

Adult↗
PubMed1999

Total number and size distribution of hepatic metastases of carcinoma.

OBJECTIVE: To quantify the susceptibility of carcinoma to hepatic metastases by studying autopsy livers with carcinoma metastases, the primary sites of which were mostly the digestive organs. STUDY DESIGN: We developed a stereologic method of estimating the total number, N, and the size distribution of metastatic tumors in the liver based on a geometric model of spherical nodules with varying radii, r. This method proved to be sufficiently reliable by disector analysis simultaneously performed in some cases; it gave an approximate result. This method was applied to the 31 autopsy cases. Correlation and regression analyses were performed among N, the mean radius of nodules, rmean, and conventional pathologic features of the primary tumor. RESULTS: The estimates of N ranged from 10 to 3.2 x 10(5). A close negative correlation was confirmed between N and rmean. Neither significant correlation nor regression was observed among N and the other pathologic factors of the primary tumors. CONCLUSION: N turned out to serve as a useful index for evaluating the metastatic potential of a carcinoma. However, investigation has yet to be made to determine biologic factors in the primary tumor closely associated with N.

Carcinoma↗
PubMed2000

[Simultaneous digestive tumors].

Synchronous and metachronous gastrointestinal tumors are well know entities, describing malignant tumors placed in the same organ, at the time of initial diagnosis or during the follow-up control. I would like to present two cases of malignant tumors placed in different organs of the digestive tube, at the time of diagnosis, coining the name simultaneous for these entities, stating laboratory finding and signo-symptomatologic interpretation difficulties, and proposing endoscopic approach as a valid diagnostic method.

Adenocarcinoma↗
PubMed2000

Laparoscopy for staging abdominal malignancies.

We continue to advocate liberal use of laparoscopy as a primary staging tool for upper GI carcinoma, believing it to be a safe, cost-effective tool with clear benefit in 20% of patients with these diseases.

Abdominal Neoplasms↗
PubMed2000

Strategies for laparoscopic diagnosis of malignancy.

Accurate cancer diagnosis and staging are crucial to the determination of an efficacious treatment plan for localized and advanced malignancy. The physician must differentiate patients with potentially resectable, localized disease from those with advanced and/or distant disease. The diagnostic and staging modalities currently available are expensive and often inaccurate. This can result in the nonoperative management of potentially resectable malignancies or, more commonly, in an underestimation of the preoperative cancer stage with intraoperative evidence of advanced/metastatic disease. The combination of laparoscopy and laparoscopic ultrasonography can be used to help diagnose and stage malignancies and select patients for either curative or palliative procedures.

Adrenal Gland Neoplasms↗
PubMed2001

Introduction to endoscopic mucosal resection.

The advent of videoendoscopes showed the very minute details of the gastrointestinal tract. Three American and five Japanese endoscopists who are experts and founders in their original EMR for the entire gastrointestinal tract were invited. All of them have tremendous experience with EMR. One can appreciate the technique and pitfalls of EMR through their data analyses based on a large number of cases. In western countries, early esophageal cancers arising from Barrett's esophagus seem to be the most likely candidates for EMR. It is hoped that these techniques aid the reader's endoscopic practice and provide a better quality of life to patients.

Digestive System Neoplasms↗
PubMed2001

Perspectives in endoscopic mucosal resection.

The birth of endoscopic mucosal resection probably can be traced back to the early days of colonoscopy and polypectomy. With the advent of colonoscopy, endoscopists began encountering pedunculated and sessile mass lesions arising from the mucosal surface. The concept of snare polypectomy developed quickly, and this technique has become the standard of care in the management of colon polyps. Large sessile lesions, however, remain problematic, especially when they arise from the thin wall of the cecum and ascending colon. Serosal burns and frank perforations represent the most significant complication of this technique.

Digestive System Neoplasms↗
PubMed2001

[Molecular genetics and gene therapy in diseases of the esophagus, stomach, colon and pancreas].

There has been a major improvement in our knowledge in the area of molecular genetics in the past 20 years. It has become evident that genetic factors are important in the initiation, progression and prognosis of most diseases. Many studies addressed the issue of tumorigenesis, which provided insight into the molecular basis of the sequencional development of cancer, driven by the accumulation of genomic defects. Most of the neoplasms are genetically heterogeneous, independent pathways and simultaneous tumorigenesis may exist within the same organ. As some mutations exist in benignant and also in malignant conditions, it is an important challenge to define the molecular characteristics of significant versus non-significant lesions. A new form of therapeutic intervention is gene therapy. During the next decade it will likely play an increasing role in clinical practice and particularly in the treatment of cancer.

Animals↗
PubMed2002

[Binding pancreaticojejunostomy: clinical report of 150 cases].

OBJECTIVE: To study the safety and feasibility of a new operative procedure called binding pancreaticojejunostomy (BPJ) used to prevent anastomotic leakage following pancreatoduodenectomy (PD). METHODS: From 1996 to 2001, a newly developed operative procedure, binding pancreaticojejunostomy, was performed upon 150 cases undergoing PD. The remnant of pancreas was sutured with and invaginated into the jejunum, with the suture needle only penetrating the mucosa and not the seromuscular layer. The mucosa of jejunum near the pancreatic remnant was destroyed by electric coagulation or phenol. The pancreas and jejunum were bound together so that they were pressed close to each other. The clinical data were reviewed and analysed. RESULTS: The operation of BPJ was performed smoothly on all 150 patients. No pancreatic leakage occurred. CONCLUSION: The BPJ procedure is effective in avoiding anastomotic leakage following PD.

Adult↗
PubMed2003

Untreatable pain resulting from abdominal cancer: new hope from biophysics?

CONTEXT: Visceral pain characterizing pancreatic cancer is the most difficult symptom of the disease to control and can significantly impair the quality of life which remains and increase the demand for euthanasia. AIM: To investigate a possible new method based on biophysical principles (scrambler therapy) to be used in the effective treatment of drug-resistant oncological pain of the visceral/neuropathic type. SETTING: Eleven terminal cancer patients (3 pancreas, 4 colon, 4 gastric) suffering from elevated drug resistant visceral pain. DESIGN: The trial program was related to the first ten treatment sessions. Subsequently, each patient continued to receive treatment until death. MAIN OUTCOME MEASURES: Pain measures were performed using the visual analogue scale before and after each treatment session and accompanied by diary recordings of the duration of analgesia in the hours following each single application. Any variation in pain-killing drug consumption was also recorded. RESULTS: All patients reacted positively to the treatment throughout the whole reference period. Pain intensity showed a significant decrease (P<0.001), accompanied by a gradual rise both in the pain threshold and the duration of analgesia. Nine (81.8%) of the patients suspended pain-killers within the first 5 applications, while the remaining two (18.2%) considerably reduced the dosage taken prior to scrambler therapy. No undesirable side effects were observed. Compliance was found to be optimal. CONCLUSIONS: The preliminary results obtained using scrambler therapy are extremely encouraging, both in terms of enhanced pain control after each treatment session and in view of the possible maintenance of effectiveness over time.

Abdominal Pain↗