Biomedical subjects

P J Lou

Publications and source records attributed to P J Lou.

14 recordsLinked to original sources

PubMed2001

Induction chemotherapy with mitomycin, epirubicin, cisplatin, fluorouracil, and leucovorin followed by radiotherapy in the treatment of locoregionally advanced nasopharyngeal carcinoma.

PURPOSE: Survival in advanced nasopharyngeal carcinoma (NPC) is compromised by distant metastasis. Because mitomycin is active against hypoxic and G0 cells, which may help to eradicate micrometastasis, we investigated the effect of mitomycin-containing cisplatin-based induction chemotherapy. PATIENTS AND METHODS: Recruited for this study were American Joint Committee on Cancer (AJCC) 1992 staging system stage IV NPC patients with the following adverse features: obvious intracranial invasion, supraclavicular or bilateral neck lymph node metastasis, large neck node (> 6 cm), or elevated serum lactate dehydrogenase (LDH) level. Patients were given three cycles of chemotherapy before radiotherapy. The chemotherapy comprised a 3-week cycle of mitomycin, epirubicin, and cisplatin on day 1 and fluorouracil and leucovorin on day 8 (MEPFL). RESULTS: From January 1994 to December 1997, 111 patients were recruited. The median follow-up period was 43 months. The actuarial 5-year overall survival rate was 70% (95% confidence interval [CI], 60% to 80%; n = 111). For patients having completed radiotherapy (n = 100), the 5-year locoregional control rate was 70% (95% CI, 55% to 84%) and the distant metastasis-free rate was 81% (95% CI, 73% to 89%). The 5-year distant metastasis-free rate of N3a and N3b disease of AJCC 1997 staging system were 79% (95% CI, 62% to 95%) and 74% (95% CI, 60% to 89%), respectively. By Cox multivariate analysis, high pretreatment serum LDH level (P = .04) and neck nodal enlargement before radiotherapy (P = .001) were adverse prognostic factors of survival. CONCLUSION: The good 5-year survival of N3 disease supports the effectiveness of induction MEPFL in the primary treatment of advanced NPC. Further investigation to incorporate concurrent chemoradiotherapy is warranted.

Adolescent↗

PubMed2001

Intracranial relapse of nasopharyngeal carcinoma manifested as sudden deafness.

OBJECTIVE: To differentiate tumor relapse from postirradiation sudden deafness (PISD) in patients with nasopharyngeal carcinoma (NPC). STUDY DESIGN: A retrospective study from December 1991 to November 1999. SETTING: University hospital. PATIENTS: Twenty-five irradiated NPC patients with sudden deafness were investigated. All patients received local examination of ears, nose, nasopharynx, and throat fields, as well as a battery of audiologic and neurotologic tests. RESULTS: Three patients with sudden deafness within 3 years after irradiation received a diagnosis of tumor relapse. Magnetic resonance imaging revealed cerebellopontine angle metastasis in one and intracranial invasion in two. Comparison of the remaining 22 NPC patients who had PISD showed that the mean interval between the completion of irradiation to the onset of sudden deafness was 10+/-5 years. CONCLUSION: Magnetic resonance imaging should be performed to exclude intracranial relapse if sudden deafness develops in a patient with NPC within 5 years after irradiation.

Adult↗

PubMed2001

Multicentricity of intraparotid facial nerve schwannomas.

Facial nerve schwannomas are uncommon neoplasms. Multiple schwannomas of the facial nerve in the parotid region are rare. Research regarding the pathogenesis of multiple facial nerve schwannomas is incomplete. Both the neoplastic bridging of tumor cells and tumor multicentricity have been hypothesized. We present a case of multiple intraparotid facial nerve schwannomas. In this case, the histologic features of the tumors support the multicentric hypothesis.

Adult↗

PubMed2001

Primary cutaneous adenoid cystic carcinoma with regional lymph node metastasis.

Primary cutaneous adenoid cystic carcinoma (PCACC) is a particularly rare variant of sweat gland carcinoma with characteristics of indolent and progressive course and high incidence of perineural invasion and local recurrence. However, regional lymph node metastasis in PCACC is exceedingly rare and its prognostic implication is unknown. Only two previous cases of recurrent scalp PCACC were reported to be associated with cervical lymph node metastases at 42 months and 20 years, respectively, after the initial treatment. We present a case of PCACC occurring in the left parotid region with regional neck lymph node metastasis in a 64-year-old man. Because the occurrence of lymph node metastasis seems to be associated with recurrent PCACC, we suggest that neck dissection may be included in the treatment for recurrent PCACC patients.

Carcinoma, Adenoid Cystic↗

PubMed2001

Factors affecting the overall survival after salvage surgery in patients with recurrent nasopharyngeal carcinoma at the primary site: experience with 60 cases.

OBJECTIVE: To analyze the factors affecting overall survival after salvage surgery in patients with recurrent nasopharyngeal carcinoma at the primary site after a full course of radiotherapy. DESIGN: Retrospective analysis of 60 consecutive patients treated by surgical resection of the recurrent tumors, with a mean follow-up of 43.1 months (range, 19-96 months). SETTING: Academic tertiary referral center. RESULTS: The overall survival and locoregional relapse-free survival were 56% and 60% at 2 years, respectively, and 30% and 40% at 5 years. Twenty-nine (81%) of 36 patients died with uncontrolled local disease. The T stage of the recurrent tumors appeared to be an important prognostic factor. Age, sex, pathologic findings, and disease-free interval (time between previous radiotherapy and local recurrence) were not significant prognosis-affecting factors by the log-rank test. Multivariate analysis showed that patients with recurrent tumors of undifferentiated carcinoma, sarcoma, or small cell carcinoma had unfavorable prognoses. Uncontrolled local disease and the emergence of distant metastasis predicted grave results as well. Postoperative irradiation showed some benefit to patients, but the difference was not statistically significant. CONCLUSIONS: The T stage of the recurrence was the prominent prognosis-affecting factor in patients with recurrent nasopharyngeal carcinoma who received salvage surgery. Patients with local recurrence should be carefully selected for the salvage surgery. We recommend this surgery for patients with rT1, rT2, or limited rT3 lesions. The results of surgical resection in terms of local control and overall survival were slightly better than those of high-dose reirradiation, with fewer late complications.

Adult↗

PubMed2000

Taxol reduces cytosolic E-cadherin and beta-catenin levels in nasopharyngeal carcinoma cell line TW-039: cross-talk between the microtubule- and actin-based cytoskeletons.

Taxol affects microtubule dynamics by promoting microtubule assembly. To obtain a better insight into possible cross-talk between the microtubule- and actin-based cytoskeletons, we studied the short-term effects of Taxol treatment on the expression of actin and the E-cadherin/catenin complex in the nasopharyngeal carcinoma cell line TW-039 using immunofluorescence, immunoprecipitation, and immunoblotting methods. Morphologic changes in actin filaments, including ventral actin clumps and perijunctional actin blebs, were seen at Taxol concentrations > or =1 microM. Levels of detergent-soluble E-cadherin fell to 53% or 58% compared to controls in cells treated, respectively, with 1 or 5 microM Taxol, while levels of detergent-soluble beta-catenin fell to 76% or 74%. Levels of the detergent-soluble pool of alpha- and gamma-catenin and the detergent-insoluble pool of the E-cadherin/catenin complex were unchanged by Taxol treatment and no significant difference was seen in the levels of adenomatous polyposis coli or glycogen synthase-3beta or tyrosine phosphorylation patterns. These results suggest that modulation of microtubule dynamics by Taxol may have effects on the expression of actin and the cytosolic E-cadherin and beta-catenin in nasopharyngeal carcinoma cells through pathways not involving the phosphorylation of beta-catenin.

Actins↗

PubMed2000

Mucociliary transport pathway on laryngotracheal tract and stented glottis in guinea pigs.

We investigated the laryngotracheal mucociliary transport pathway of guinea pigs in vivo and immediately postmortem. Only intraperitoneal anesthesia was used during the procedure to avoid the disturbance of mucociliary function. Resin particles were used as the marking substance. A microcolpohysteroscope was placed at different levels in the laryngotracheal region for observing the marking particles and recording the transport pattern. The tracheal mucociliary transport flow primarily moved along the posterior wall and both lateral walls in a zigzag trace. Upon reaching the subglottis, the resin particles stayed underneath the vocal cords, and a whirlpool phenomenon developed. The majority of the particles were shifted and directed onto the posterior glottic area. With a short delay, some resin particles crossed over the free edge of the vocal cords and turned posteriorly along the medial upper cordal margin. No mucociliary transport could be observed on the entire upper surface of the true vocal cords, which is covered by squamous epithelium. Occasionally, a few resin particles in the vicinity of the epiglottic root traveled along the aryepiglottic folds toward the posterior commissure. All streams of mucociliary transport finally joined together in the interarytenoid area. After leaving the glottis, the resin particles traveled to the hypopharynx and entered the esophagus through the motion of deglutition. The pattern of mucociliary clearance in the laryngotracheal region was not delayed by stenting.

Animals↗

PubMed2000

Actinomycosis imitating nasopharyngeal carcinoma.

The incidence of nasopharyngeal actinomycosis is exceedingly rare. To our knowledge, only 1 case has been reported previously. This article presents 4 cases of actinomycosis involving the nasopharynx that imitated nasopharyngeal carcinoma. Acidic gas exposure and farming of aquatic products are possibly involved in the pathogenesis of nasopharyngeal actinomycosis. Patients in the case studies completely recovered after 4 weeks of oral antibiotic treatment. We recommend including actinomycosis in the differential diagnosis of nasopharyngeal neoplasms.

Abscess↗

PubMed1999

Post-irradiation sudden deafness.

As in radiation-induced cancer, post-irradiation sudden deafness (PISD) is defined as sudden onset deafness in patients post-irradiation. Fifteen nasopharyngeal carcinoma (NPC) patients with PISD were enrolled in this study. The mean interval from the completion of irradiation to the occurrence of PISD was 12 years. Seven had total deafness, seven had profound hearing loss, and one had moderate hearing loss. Nine out of 15 (60 per cent) patients experienced hearing recovery within three months after treatment. In conclusion, PISD is a late complication in NPC patients post-irradiation. The causative mechanism is theorized as vascular insufficiency.

Adult↗

PubMed1999

Spontaneous resolution of internal jugular vein thrombosis in a Salmonella neck abscess patient.

This article describes a rare case of Salmonella neck abscess complicated by internal jugular vein thrombosis in a 51-year-old patient with previously undiagnosed diabetes. The patient was discharged without any complications after a combination of medical and surgical treatment. Also discussed here are the clinical manifestations, imaging findings, and spontaneous resolution of the internal jugular vein thrombosis. Being immunocompromised is a critical predisposing factor for Salmonella neck abscess. Patient recovery is largely determined by proper incision, drainage of pus and adequate intravenous antibiotics according to bacterial sensitivity tests. Detection of an internal jugular vein thrombosis does not signify a poor prognosis. Spontaneous resolution of thrombosis is encountered after treating the infection.

Abscess↗

PubMed1999

Patulous eustachian tube in long-term survivors of nasopharyngeal carcinoma.

This article reports on 21 long-term (10 years) survivors of nasopharyngeal carcinoma, divided into 2 groups: those subjected to an inflation-deflation test and a clearance function test in a longitudinal study, and those receiving sonotubometry in a cross-sectional study. On the inflation-deflation test, 12 (55%) out of 22 ears had a patulous eustachian tube, and on sonotubometry, 10 (50%) out of 20 ears also revealed a patulous eustachian tube. Except for 4 ears with chronic otitis media, the ears had resolved to a normal eardrum appearance at 10 years postirradiation. The phenomenon might be attributed to both restoration of the impaired tubal function and the development of a patulous tube.

Case-Control Studies↗

PubMed1999

Delayed irradiation effects on nasal epithelium in patients with nasopharyngeal carcinoma. An ultrastructural study.

The ostiomeatal complex is responsible for the clearance of most sinus secretions. To evaluate the delayed effects of irradiation. this study examined the infundibulum mucosa of 10 patients who developed sinusitis after receiving radiotherapy for nasopharyngeal carcinoma (NPC). Pathologic findings under the light microscope revealed an increased deposition of dense collagenous fibers in the lamina propria. The epithelial cells also transformed into a stratified arrangement and showed gradual reduction of cytoplasmic volume. Ultrastructural observations detected areas of ciliary loss, intercellular and intracellular vacuolation, and ciliary dysmorphism. Most of these pathologic findings were observed even in a patient 23 years after irradiation. The results presented herein suggest that radiotherapy may cause long-term damage to the nasal epithelium that may be responsible for the prolonged sinusitis of irradiated NPC patients.

Adult↗

PubMed1999

E-, P-, and N-cadherin are co-expressed in the nasopharyngeal carcinoma cell line TW-039.

The cadherin/catenin complex plays a key role in the initiation of cell-cell recognition, and adhesion, and the elaboration of structural and functional organization in multicellular tissues and organs. It is associated with tumor metastasis and also acts as an "invasion suppressor" of cancer cells. Nasopharyngeal carcinoma (NPC) is notorious for its highly metastatic nature. The expression of the E-cadherin/catenin complex is down-regulated in NPC tumor specimens. To obtain better insight into the intercellular adhesive property of NPC cells, we used immunofluorescence microscopy, immunoprecipitation, and immunoblot analysis to examine the expression of the classical cadherins and beta-catenin in a NPC cell line, TW-039. The results demonstrate a change in the distribution of E-cadherin from cytosolic flakes to cell-cell contacts with increasing time in culture. Between days 1 and 5 after plating, the detergent-insoluble fraction of E-cadherin increased from 20% to 37% of total E-cadherin, and that for P-cadherin increased from 33% to 40%. By contrast, the values for beta-catenin remained unchanged (26% and 25%). Both immunofluorescence and immunoblot studies suggested that P-cadherin may be involved in pioneer contact adhesion of TW-039 cells. Interestingly, E-, P-, and N-cadherin are co-expressed in this cell line. Immunoprecipitation studies also showed that other members of the cadherin family may be involved in the contact adhesion of TW-039 cells.

Blotting, Western↗

PubMed1998

Increased mutagen sensitivity in patients with head and neck cancer is less pronounced in patients with nasopharyngeal carcinoma.

BACKGROUND: Mutagen sensitivity tested with bleomycin sulfate can determine a susceptible phenotype, which is relevant only in organs and tissues that have direct contact with the external environment. Patients with head and neck cancers have more mutagen sensitivity than control subjects without cancer, and the hypersensitive phenotype has a risk for the development of a second primary cancer. Head and neck cancers, however, represent a heterogeneous group of neoplasm. The biological behavior of nasopharyngeal carcinoma (NPC) and other head and neck cancers differs. OBJECTIVE: To evaluate the difference in mutagen sensitivity among patients without cancer, patients with NPC, patients with oral or oropharyngeal cancer (ORC), and patients with laryngeal or hypopharyngeal cancer (LHC). DESIGN: Peripheral blood was cultured at 37 degrees C, using 5% carbon dioxide, for 72 hours. After 67 hours of incubation, bleomycin in a concentration of 30 IU/L was added to induce chromatid breaks. The number of chromatid breaks per cell was scored in 50 metaphases of cultured lymphocytes and compared in the 4 groups. SUBJECTS: Patients with histologically proven squamous cell carcinoma of the mucosa of the upper digestive tract, which included 3 groups: patients with NPC, patients with ORC, and those with LHC. Control subjects were hospital inpatients with no tumor history. There were 35 patients in each group. RESULTS: The mean (+/-SD) number of breaks per cell in the control group and in the groups with NPC, ORC, and LHC were 0.80 (+/-0.32), 1.03 (+/-0.45), 1.30 (+/-0.44), and 1.35 (+/-0.46), respectively. All the cancer groups had significantly higher mean breaks per cell and a higher prevalence of hypersensitivity than the control group. Patients with NPC had a significantly lower mean number of breaks per cell than the group with ORC or that with LHC. CONCLUSIONS: Patients with NPC had less mutagen sensitivity than those with ORC or LHC. Our results support the clinical and epidemiological findings of a difference between NPC and other head and neck cancers. Environmental factors might play a less pronounced role in the carcinogenesis of NPC.

Adult↗