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Biomedical subjects

James Lee

Publications and source records attributed to James Lee.

42 records · Page 3Linked to original sources
PubMed2002

Helicobacter pylori CagA seropositivity and gastric carcinoma risk in a Japanese American population.

Helicobacter pylori colonization is associated with gastric cancer, but whether and to what extent the risk is greater for strains with the cagA gene than for those without needs to be determined. Between 1967 and 1977, 9963 Japanese American men were recruited and examined. By 1996, incident cases of gastric carcinoma of the distal stomach had been diagnosed in 261 men. Stored serum samples from these case patients and 261 age-matched control subjects were tested for immunoglobulin G antibodies to H. pylori and to the CagA product of H. pylori, using antibody-specific enzyme-linked immunosorbent assays. Compared with H. pylori-negative, CagA-negative men, H. pylori-positive, CagA-negative men had an odds ratio (OR) of 2.7 (95% confidence interval [CI], 1.3-5.6) for intestinal gastric carcinoma. Men seropositive for both H. pylori and CagA had an OR of 4.1 (95% CI, 2.2-7.7). This suggests that colonization by an H. pylori strain with the cagA gene is associated with a greater risk of intestinal gastric carcinoma.

Adult↗
PubMed2002

Relation between Helicobacter pylori cagA status and risk of peptic ulcer disease.

Although colonization with any Helicobacter pylori strain is associated with peptic ulcer, it is uncertain whether the risk is greater with cagA(+) or cagA(-) strains, which differ in their biology. A nested case-control study was done, based on a cohort of 5,443 Japanese-American men examined on the Hawaiian island of Oahu from 1967 to 1970. A total of 150 men with gastric ulcer, 65 with duodenal ulcer, and 14 with both diseases were identified. The authors matched the 229 cases with 229 population controls and tested their serum for immunoglobulin G antibodies to H. pylori and immunoglobulin G antibodies to the cagA product of H. pylori using enzyme-linked immunosorbent assays. Persons with H. pylori positivity had an odds ratio of 4.0 (95% confidence interval (CI): 1.9, 8.5) for gastric ulcer and 2.5 (95% CI: 0.8, 7.4) for duodenal ulcer. For CagA positivity, the odds ratios were 1.4 (95% CI: 0.9, 2.4) for gastric ulcer and 2.6 (95% CI: 1.1, 5.8) for duodenal ulcer. Subjects who were seropositive for both H. pylori and CagA had an odds ratio of 4.4 (95% CI: 1.8, 10.5) for gastric ulcer and 5.8 (95% CI: 1.1, 30.0) for duodenal ulcer. The results suggest that colonization with a cag(+) H. pylori strain elevates the risk beyond that of a cag(-) H. pylori strain for both gastric and duodenal ulcers.

Antibodies, Bacterial↗
PubMed2002

Regression of a descending thoracoabdominal aortic dissection following staged deployment of thoracic and abdominal aortic endografts.

PURPOSE: To describe the successful endovascular repair and regression of an extensive descending thoracoabdominal aortic dissection associated with thoracic and abdominal aortic aneurysms. CASE REPORT: An 83-year-old man presented with acute chest pain and shortness of breath. A descending thoracoabdominal aortic dissection that extended from near the left subclavian artery (LSA) to the right common iliac artery was found on computed tomography. Separate aneurysms in the thoracic and abdominal aorta were also identified. Staged endovascular procedures were undertaken to (1) close the single entry site and exclude the aneurysm in the thoracic aorta with an AneuRx thoracic stent-graft, (2) exclude the abdominal aneurysm and distal re-entry site with a bifurcated AneuRx endograft, and (3) treat a newly dilated thoracic segment between the LSA and first thoracic stent-graft. At 1 year, the false lumen had completely disappeared, the thoracic aneurysm had collapsed onto the endograft, and the abdominal aneurysm had shrunk by 30%. CONCLUSIONS: The potential to treat extensive aortic dissections with the hope that they might regress is promising, but repair of highly complex lesions involving one or more aneurysms in addition to the dissection requires meticulous imaging studies both preoperatively and intraprocedurally.

Aged↗
PubMedDate not supplied

Favorable clinical outcomes of three-dimensional computer-optimized high-dose-rate prostate brachytherapy in the management of localized prostate cancer.

PURPOSE: To report PSA relapse-free survival and toxicity outcomes of prostate cancer patients who have undergone three-dimensional computer-optimized high-dose-rate (HDR) brachytherapy with external beam radiotherapy as definitive treatment. METHODS AND MATERIALS: One hundred five patients consecutively treated between 1998 and 2004 are reported. All patients were treated with HDR boost with lr 192 (5.5-7.0 Gy), based upon postimplant CT three-dimensional treatment planning using an in-house treatment plan optimization algorithm. Three-dimensional conformal external beam radiotherapy (45-50.4 Gy) was also administered 3 weeks after the HDR procedure. Toxicity was measured using National Cancer Institutes Common Toxicity Criteria and International Prostate Symptom Score indices. RESULTS: With a median followup of 44 months (8-79 months), the 5-year PSA relapse-free survival outcomes for low, intermediate and high-risk patients were 100%, 98%, and 92%, respectively, Median urinary toxicity, and 93% of patients denied rectal problems at the time of last followup. Erectile dysfunction was noted in 47% patients at the time of last followup, but overall 80% were able to achieve vaginal penetration when those who responded to sildenafil were included. CONCLUSION: Computer-optimized three-dimensional HDR prostate brachytherapy provides excellent disease control for even high risk localized prostate cancer. Significant toxicity has been minimal.

Adult↗
PubMedDate not supplied

Novacor left ventricular assist system long-term performance: comparison of clinical experience with demonstrated in vitro reliability.

Since the first implant of the Novacor wearable left ventricular assist system (LVAS) in 1993, median implant duration worldwide has increased from 93 days (max 2.2 years) to 202 days (max 4.1 years) in May 2001. In vitro reliability/durability testing of the Novacor LVAS has previously demonstrated a mean time to failure of 4.2 (3.04-5.59) years. These tests revealed a single failure mode--main bearing wear--with measurable symptoms gradually appearing before degradation of pump function. An ongoing clinical study of 37 recipients implanted for more than 1 year has shown that a simple noninvasive method of pump surveillance, derived from the in vitro experience, is well tolerated in the clinical setting. The overall clinical experience is consistent with in vitro reliability/durability tests that demonstrated 99.9%, 98.5%, and 87.4% freedom from wear at 1, 2, and 3 years (80% confidence). So far, the clinical study has shown 99.4%, 91.5%, and 91.5% freedom from wear at the same 1, 2, and 3 year intervals (95% confidence). Furthermore, the clinical findings have corroborated the in vitro experience that the wear mechanism is generally measurable and gradual, enabling elective clinical LVAS replacement or transplantation. Clinical valve performance was also monitored, using an exercise protocol and collecting comparative data on peak flows across the valves. It was determined that developing valve dysfunction could be diagnosed early and, in the failures that did occur (n = 2), these were related to the patient's disease state. In conclusion, although clinical conditions exposed the LVAS to a wide range of different environmental and hydraulic stresses, the surveillance program described appears practical and reliable, and its findings broadly parallel those of the earlier in vitro study. Additional data needed to complete formal validation continue to be collected.

Adult↗