Biomedical subjects

E Park

Publications and source records attributed to E Park.

113 records · Page 7Linked to original sources

PubMedDate not supplied

Taurine protects rat bronchioles from acute ozone exposure: a freeze fracture and electron microscopic study.

Dietary taurine has been shown to protect rat and hamster lung epithelia from acute oxidant injury. One of the earliest morphologic criteria of oxidant injury is the alteration of tight junctions of the peripheral lung airways. In the present study, we have used this criteria to evaluate whether taurine was capable of protecting rat lungs from ozone exposure. Rats were treated for 10 days with 50% taurine in their drinking water, prior to exposure to 2 ppm of ozone for 3 hours. The lungs from rats pretreated with taurine and exposed to ozone were compared to untreated rats exposed to ozone and air-exposed controls. At 2, 6, 12, 24, 48, and 72 hours after exposure to air or ozone, rats were anesthetized and the lungs perfusion-fixed through the right side of the heart with a solution of glutaraldehyde and paraformaldehyde. Light microscopy revealed the typical, mild inflammatory cell infiltrate beginning at 6 hours after ozone exposure in bronchioles, alveolar ducts, and surrounding alveoli which was absent in the lungs of animals treated with taurine. Electron microscopic analysis of thin sections indicated alterations in tight junctions which was confirmed by tracer studies using ruthenium red and lanthanum. Alterations in airway epithelium tight junctions were seen 2 and 6 hours after ozone treatment and only in the 2-hour tissues from animals pretreated with taurine prior to ozone exposure. Freeze-fracture replicas from all exposure groups by electron microscopy revealed that only the 2- and 6-hour groups showed alterations in tight junctions. The alterations were characterized by decreased number of fibrils and breaks in the fibrils. Rats treated with taurine and exposed to ozone exhibited these alterations focally at 2 hours exposure and no changes were noted at 6 hours post ozone exposure. These data confirmed previous findings that injury induced by ozone is transient and that taurine protects the bronchioles from this form of oxidant injury.

Animals↗

PubMedDate not supplied

Radiosurgery for brain metastases from primary lung carcinoma.

PURPOSE: Brain metastases are a common problem in patients with lung cancer. This retrospective review was performed to describe the efficacy and toxicity of stereotactic radiosurgery for brain metastases from lung carcinoma and to evaluate prognostic factors for survival. PATIENTS AND METHODS: A retrospective review was performed of 113 patients with the diagnosis of lung carcinoma who underwent radiosurgery with or without whole-brain radiotherapy for management of newly diagnosed or recurrent, single, or multiple brain metastases from 1991 through 1998 at the University of California, San Francisco. Freedom from progression and survival were measured from the date of radiosurgery and estimated using the Kaplan-Meier method. Prognostic factors were evaluated with the log-rank test and Cox proportional hazards models. RESULTS: The median patient age at the time of radiosurgery was 59 years (range, 37-82 years), and the median Karnofsky performance score was 90 (range, 50-100). The median survival time from radiosurgery was 12.0 months overall, 13.9 months for 41 patients treated with radiosurgery alone initially, 14.5 months for 19 patients treated with radiosurgery and whole-brain radiotherapy initially, and 10.0 months for 53 patients with recurrent brain metastases. Among newly diagnosed patients, multivariate analysis showed that improved survival was associated with absence of extracranial metastases and fewer brain metastases. Among patients with recurrent brain metastases, improved survival was associated with higher Karnofsky performance score, control of the primary tumor, and fewer metastases. Measured by lesion, 1-year local freedom from progression probabilities were 81% for radiosurgery alone, 86% for radiosurgery and whole-brain radiotherapy, and 65% for radiosurgery performed after recurrence. In patients with newly diagnosed brain metastases, there was a significantly greater risk of developing subsequent brain metastases and of worse overall brain freedom from progression after radiosurgery alone versus radiosurgery and whole-brain radiotherapy. One-year brain freedom from progression probabilities were 13% without salvage therapy and 62% with salvage therapy in the 41 patients treated initially with radiosurgery alone, versus 67% without salvage therapy and 89% with salvage therapy in the 19 patients treated initially with radiosurgery plus whole-brain radiotherapy. DISCUSSION: Radiosurgery is an effective therapy for selected patients with newly diagnosed or recurrent brain metastases from lung carcinoma. Initial whole-brain radiotherapy with radiosurgery appears to improve brain control but not survival. Prospective, randomized trials are needed to further investigate the role of radiosurgery with and without whole-brain radiotherapy for brain metastases.

Adenocarcinoma↗

PubMedDate not supplied

Prognostic studies on gastric cancer with concomitant liver metastases.

BACKGROUND/AIMS: The aim of this study was to clarify prognostic factors after surgical treatments in gastric cancer patients having synchronous liver metastases. METHODOLOGY: Clinicopathological features and prognosis were retrospectively reviewed in 43 surgical patients with gastric cancer with concomitant liver metastases from 1984 to 1998. RESULTS: More than half of the patients (51.2%) had numerous liver metastases (H3). Rates of peritoneal metastases (P1, P2, P3: 34.9%), tumor serosal invasion (T3 or T4: 73.8%) and widespread lymph node metastases (N3, N4: 69.8%) were also high. Although the gastric resection was performed in 29 patients (67.5%), concomitant hepatectomy resection was performed in only 3 patients (7.0%). Univariate analysis revealed that the grade of liver metastases (H1, H2, H3) was only a statistically significant prognostic factor (P = 0.008). Concerning surgical treatments, the resection group had tendency to better survival than the nonresection group (P = 0.074). Eight cases survived more than 1 year. Seven of the 8 cases (87.5%) were patients with gastrectomy. All of the 5 two-year survivors were patients with gastrectomy. CONCLUSIONS: In patients with gastric cancer with concomitant liver metastases, the grade of liver metastases indicate prognosis. In addition, there is possibility of palliative gastrectomy increasing the survival rare to more than one year.

Adult↗

PubMedDate not supplied

Factors influencing survival after gamma knife radiosurgery for patients with single and multiple brain metastases.

PURPOSE: Radiosurgery has been reported to yield high local control rates for brain metastases. However, further work is needed to define which subgroups of patients may benefit from this treatment modality. PATIENTS AND METHODS: We reviewed 116 patients who underwent stereotactic radiosurgery for initial management or recurrence of solitary or multiple brain metastases from September 1991 through December 1994 at the University of California, San Francisco. Survival time and time to local-regional failure were calculated using the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Cox proportional hazards model. RESULTS: Median survival was 40 weeks from radiosurgery. In multivariate analysis, smaller total tumor volume, absence of extracranial metastases, higher Karnofsky score, and age < or = 70 had a positive effect on survival. In patients initially managed for brain metastases, the addition of whole brain radiotherapy to radiosurgery had no significant effect on survival. Although the presence of multiple metastases was associated with a significantly worse survival rate in patients initially managed with radiosurgery in univariate analysis, it was not as a significant factor in multivariate analysis. An analysis of patients within this series treated with radiosurgery who would have been eligible for Patchell's study on the role of surgery in the treatment of solitary brain metastasis revealed a favorable median survival of 70 weeks. CONCLUSIONS: We conclude that radiosurgical treatment of brain metastases results in survival times that compare favorably with the historic experience in patients treated with whole brain radiotherapy alone or with surgical resection. In patients presenting initially with brain metastases, radiosurgery alone may yield survival results equivalent to radiosurgery with whole brain radiotherapy, but intracranial control and quality of life also need to be evaluated. Also, the presence of multiple brain metastases should not be a contraindication for the use of radiosurgery given the good survival achieved with such patients in this series. Each such case should therefore be evaluated based on other factors such as patient's age, Karnofsky score and systemic disease.

Adolescent↗

PubMedDate not supplied

Uterine closure with the endo stitch 10-mm laparoscopic suturing device--a review of 50 laparoscopic myomectomies.

OBJECTIVE: To evaluate the mechanical performance of the Endo Stitch Laparoscopic Suturing Device and the clinical effectiveness of both a running, locked suture technique and a new modified suture technique for closure of uterine defects after laparoscopic removal of myomas. STUDY SUBJECTS: Fifty consecutive patients with symptomatic uterine leiomyomata. OBSERVATIONAL METHOD: Retrospective chart review. MAIN FINDINGS: The endometrial cavity was entered and sutured laparoscopically, in two layers, in 22 patients. In 28 patients, only the myometrium was sutured. A two-layered closure of the endometrium and myometrium was completed in an average time of 10 minutes. Mechanical problems with the Endo Stitch occurred in 11 cases. In all patients with second-look laparoscopies, the fallopian tubes were patent bilaterally without adhesions. No uterine fistulas were present in any patients with second-look laparoscopies. Posterior myomas were removed and sutured without adhesion formation. Grade 3 adhesions, to the uterine surface, were associated with transverse incisions of the uterus and over-treatment with GnRH analogs. CONCLUSIONS: The Endo Stitch Laparoscopic Suturing Device in combination with a running, locked suture technique achieves a rapid, hemostatic, clinically secure closure of the endometrium and myometrium. The Endo Stitch and our modified suture technique were not associated with adhesions or blockage of the fallopian tubes or uterine fistulas following laparoscopic myomectomies. The initial mechanical problems with the Endo Stitch were resolved. In our experience, currently the Endo Stitch is the best instrument for laparoscopic suture closure of uterine defects.

Adult↗