Radiation-induced hearing impairment in patients treated for malignant parotid tumor

Radiation-induced hearing loss was evaluated in 21 patients with unilateral malignant parotid tumors treated with surgery and radiotherapy. The contralateral ear was used as a control. Eight patients (38%) were found to have a reduction in static compliance of the tympanic membrane (type B tympanogram) in the irradiated ear. By audiometry, significant hearing loss was found in 9 patients (43%). These hearing losses were mainly sensorineural, as shown by a similar reduction in both air and bone conduction, although mixed-type hearing loss existed in some patients. A statistically significant difference in incidence of 67% versus 0% (p = .0085) was noted for patients with a cochlear dose of greater than or equal to 60 Gy, in comparison to those receiving doses of less than 60 Gy. A type B tympanogram was also found to be a prognostic factor for significant sensorineural hearing loss. Patients with type B tympanograms had a much higher incidence of significant sensorineural hearing loss than those with type A tympanograms (88% versus 15%, p = .02). This study clearly shows that radiotherapy can induce significant hearing impairment, especially when the cochlear doses are higher than 60 Gy.

Rapid induction of cytokine gene expression in the lung after single and fractionated doses of radiation

PURPOSE

To investigate cytokine gene expression in the lung after single and fractionated doses of radiation, and to investigate the effect of steroids and the genetic background.

MATERIALS AND METHODS

Expression of cytokine genes (mTNF-alpha, mIL-1alpha, mIL-1beta, mIL-2, mIL-3, mIL-4, mIL-5, mIL-6, mIFN-gamma) in the lungs of C3H/HeJ and C57BL/6J mice was measured by RNase protection assay at different times after various doses of radiation. The effects of dexamethasone and fractionated radiation treatment on gene expression were also studied.

RESULTS

IL-1beta was the major cytokine induced in the lungs of C3H/HeJ mice within the first day after thoracic irradiation. Radiation doses as low as 1 Gy were effective. Responses to 20 Gy irradiation peaked within 4-8h and subsided by 24 h. With the exception of IL-1alpha and TNF-alpha, the other cytokines that were investigated had undetectable pre-treatment mRNA levels and were not radiation inducible. Similar responses were seen in C57BL/6J mice, although TNF-alpha was induced and there were some quantitative differences. Pre-treatment of C3H/HeJ mice with dexamethasone reduced basal and induced IL-1 levels, but complete inhibition was not achieved. Dexamethasone was also effective if given immediately after irradiation. Fractionated daily doses of radiation (4 Gy/day) helped to maintain cytokine gene expression for a longer period.

CONCLUSIONS

Inflammatory genes are rapidly induced in the lung by irradiation. This response cannot be readily abolished by steroid pre-treatment. Fractionated treatment schedules help to perpetuate the response.

Recurrent cervical carcinoma after primary radical surgery

OBJECTIVE

This study was undertaken to investigate prognostic factors in patients with recurrent cervical carcinoma who had undergone a primary radical hysterectomy and pelvic lymphadenectomy.

STUDY DESIGN

A retrospective analysis of 177 patients with recurrent cervical carcinoma after radical hysterectomy and pelvic lymphadenectomy for stage IB to II disease at a single institution was performed to evaluate clinicopathologic parameters, time to recurrence, pattern of failure, use of salvage therapy, and survival after recurrence.

RESULTS

The 5-year survival rate from diagnosis of recurrence in this series was 10.1%. Survival after recurrence was significantly decreased in patients with pelvic lymph node metastasis at primary surgery and adenocarcinoma-adenosquamous carcinoma histologic type. Patients with extravaginal recurrences receiving chemoradiation for recurrent cervical carcinoma had significantly better outcomes than those receiving radiation alone. Six patients who had a distant relapse at a sole site had prolonged survival after salvage therapy, which was accomplished by chemoradiation, surgery plus radiotherapy, or surgery alone.

CONCLUSIONS

Our results demonstrate the benefit of adding chemotherapy to radiotherapy in the treatment of recurrent cervical carcinoma. Salvage multimodality treatment should be offered to selected patients who have isolated relapse at a single distant site.

Light-controlled electro-optic power limiter with a Bi(12)SiO(20) crystal

An optical power limiter is a self-actuating nonlinear optical device that transmits low-intensity light and blocks high-intensity light. A light-controlled electro-optic power limiter that uses a Bi(12)SiO(20) crystal has been demonstrated. The threshold light intensity is determined by the control light and can be set to any desired level. The response time of the light-controlled electro-optic power limiter is of the order of 1 ms.

Detection of human papillomavirus types 16 and 18 mRNA in peripheral blood of advanced cervical cancer patients and its association with prognosis

PURPOSE

To evaluate the feasibility of detecting human papillomavirus E6 (HPVE6) gene mRNA in the peripheral blood of patients with locally advanced cervical cancer, and the relationship of the circulating HPV viral-specific mRNA with clinicopathologic factors and prognosis of locally advanced cervical cancer.

PATIENTS AND METHODS

The presence of types 16 and 18 HPVE6 gene mRNA was determined by reverse transcription followed by nested polymerase chain reaction. Thirty-five patients with locally advanced cervical cancer who were positive for HPV type 16 or 18 DNA were included in the study. All patients received external-beam radiation therapy followed by intracavitary brachytherapy.

RESULTS

Eighteen (51.4%) of 35 HPV DNA-positive cervical cancer patients had HPV-specific mRNA in their peripheral blood cells, compared with none of 17 HPV DNA-negative cervical cancer patients and none of 12 control volunteers. The presence of HPVE6 gene mRNA in peripheral blood was associated with bulky tumor volume (> 4 cm) and pelvic lymph node metastasis (tumor volume, P = .03; lymph node status, P = .03). After a median follow-up of 22 months, patients who were positive for peripheral-blood HPVE6 gene mRNA had a significantly higher risk of recurrence than those who were negative (10 of 18 v three of 17, P = .02; mean recurrent time, 20.7 months v 12.6 months, P = .02). There was also a statistically significant association of peripheral-blood HPVE6 gene mRNA positivity with distant metastasis (eight of 18 vone of 17; P = .01).

CONCLUSION

Results of this study seem to suggest that the presence of HPVE6 gene mRNA in peripheral blood may provide an early marker that identifies patients who are at risk for metastasis.

Preoperative prognostic variables and the impact of postoperative adjuvant therapy on the outcomes of Stage IB or II cervical carcinoma patients with or without pelvic lymph node metastases: an analysis of 891 cases

BACKGROUND

The purpose of this study was to investigate pretreatment variables that could predict prognosis and to evaluate the impact of postoperative adjuvant therapy on the outcomes of patients with Stage IB or II cervical carcinoma with or without pelvic lymph node metastases.

METHODS

Eight hundred ninety-one patients with Stage IB or II cervical carcinoma who underwent radical hysterectomy and bilateral pelvic lymphadenectomy as primary treatment at a single institution were analyzed. Potential prognostic variables were studied.

RESULTS

Among the variables that could be assessed before treatment, depth of cervical stromal invasion (determined by magnetic resonance imaging), clinical stage, tumor size, grade of differentiation, and DNA index (determined by flow cytometry) were independent predictors of outcome in multivariate analysis using a Cox regression model. Three distinct prognostic groups (low, intermediate, and high risk) were defined using these variables. Five-year recurrence free survival (RFS) rates for the low, intermediate, and high risk groups were 94.6%, 82.7%, and 62.3%, respectively (P = 0.0001), and overall survival (OS) rates were 98.4%, 84.5%, and 68.7%, respectively (P = 0.0001). Among patients with pelvic lymph node metastases who were free of parametrial extension, those who received postoperative chemotherapy or chemoradiotherapy had significantly better RFS (P = 0.017) and OS (P = 0.043) than those who received no adjuvant therapy. Among patients without pelvic lymph node metastases but at high risk of recurrence, those who received adjuvant radiotherapy had significantly better RFS (P = 0.015) and marginally improved OS (P = 0.087) compared with those who received no adjuvant therapy.

CONCLUSIONS

A model containing assessable pretreatment variables for predicting the prognoses of patients with early stage cervical carcinoma was formulated. Subsets of patients for whom postoperative chemotherapy or radiotherapy might be beneficial were identified. The data from this retrospective review may be useful when future prospective trials of the treatment of early stage cervical carcinoma are designed.

New classes of fluorinated L-nucleosides; synthesis and antiviral activity

The synthesis of 3'-fluorinated apionucleosides 7 and 2'-fluoro-2',3'-unsaturated L-nucleosides 8 via common synthon, 2-fluoro-butenolide 2, has been described. Among the newly synthesized nucleosides, L-2'-F-d4C, L-2'-F-d4FC and L-2'-F-d4A exhibit significant anti-HIV and anti-HBV activities.

Cysteine carboxyl O-methylation of human placental 23 kDa protein

C-Terminal carboxyl methylation of a human placental 23 kDa protein catalyzed by membrane-associated methyltransferase has been investigated. The 23 kDa protein substrate methylated was partially purified by DEAE-Sephacel, hydroxyapatite and Sephadex G-100 gel filtration chromatographies. The substrate protein was eluted on Sephadex G-100 gel filtration chromatography as a protein of about 29 kDa. In the absence of Mg2+, the methylation was stimulated by guanine nucleotides (GTP, GDP and GTPgammaS), but in the presence of Mg2+, only GTPgammaS stimulated the methylation which was similar to the effect on the G25K/rhoGDI complex. AFC, an inhibitor of C-terminal carboxyl methylation, inhibited the methylation of human placental 23 kDa protein. These results suggests that the substrate is a small G protein different from the G25K and is methylated on C-terminal isoprenylated cysteine residue. This was also confirmed by vapor phase analysis. The methylated substrate protein was redistributed to membrane after in vitro methylation, suggesting that the methylation of this protein is important for the redistribution of the 23 kDa small G protein for its putative role in intracellular signaling.

Regulation of c-fos gene transcription and myeloid cell differentiation by acute myeloid leukemia 1 and acute myeloid leukemia-MTG8, a chimeric leukemogenic derivative of acute myeloid leukemia 1

Both acute myeloid leukemia 1 and c-Fos are regulatory factors of hematopoietic cell differentiation. We identified that the c-fos promoter contains an acute myeloid leukemia 1 binding site at nucleotide positions -6-+14. c-fos promoter activity was induced by transient overexpression of acute myeloid leukemia 1 in Jurkat T-cells, but not by that of the short form of acute myeloid leukemia 1-MTG8, a chimeric acute myeloid leukemia 1 protein. In 32Dcl3 myeloid cells, stable overexpression of acute myeloid leukemia 1-MTG8 blocked the c-fos gene transcription and cell differentiation, but that of acute myeloid leukemia did not. These data suggest that acute myeloid leukemia 1 and acute myeloid leukemia 1-MTG8 reciprocally regulate the myeloid cell differentiation, possibly by the way of regulating c-fos gene transcription.

A practical synthesis of L-FMAU from L-arabinose

A practical synthesis of 2'-deoxy-2'-fluoro-5-methyl-beta-L-arabinofuranosyl uracil (14, L-FMAU) was developed from L-arabinose. L-Arabinose was converted to L-ribose 5, which was used for the synthesis of bromosugar 12 via 2,3,5-O-tribenzoyl-1-O-acetyl-beta-L-ribofuranose 8, which was subjected to condensation with silylated thymine and the resulting protected L-FMAU 13 was deprotected to afford L-FMAU in 14 steps in 8% overall yield.

Aldosterone directly induces Na, K-ATPase alpha 1-subunit mRNA in the renal cortex of rat

The change of blood pressure and the induction of Na, K-ATPase alpha 1-subunit mRNA have been investigated in the renal cortex of aldosterone-treated hypertensive rat. The increase of blood pressure by aldosterone-treatment for 25 days was decreased by the treatment of amiloride or spironolactone. The level of Na, K-ATPase alpha 1-subunit mRNA of the renal cortex in aldosterone-treated rat was increased than that in the control, and its increase was repressed by treatment of spironolactone, but not altered by the treatment of amiloride. This result suggests that the increase of Na, K-ATPase alpha 1-subunit mRNA in the renal cortex of aldosterone-treated hypertensive rat may be related with the direct induction of Na, K-ATPase mRNA without the increase of Na-traffic through Na-channel.

Regulation of Na,K-ATPase activity in renal basolateral membrane of 1-clip-1-kidney hypertensive rat

The changes of Na,K-ATPase activity and its regulation have been investigated in the renal cortex of 1-clip-1-kidney hypertensive rat. Ouabain-sensitive Na,K-ATPase activity (Emax) and [3H]ouabain-binding site (Bmax) in the hypertensive rat were slightly increased than those in the control. The levels of Na,K-ATPase alpha 1- and beta 1-subunit mRNA of the renal cortex in hypertensive rat were more increased than those in the control. Their increases were repressed by actinomycin-D, but not altered or more increased by cycloheximide. These results suggest that the increase of Na,K-ATPase activities and ouabain binding sites in 1-clip-1-kidney hypertensive rat may be correlated with the increases of gene expression in transcription level and/or of mRNA stability of Na,K-ATPase.

Implications of a failed prospective trial of adjuvant therapy after radical hysterectomy for stage Ib-IIa cervical carcinoma with pelvic node metastases

BACKGROUND

Lymph node metastasis is established as a poor prognostic factor in cervical carcinoma patients undergoing primary surgery. However the optimal postoperative therapy for node-positive patients remains to be defined.

MATERIALS AND METHODS

To determine the role of adjuvant therapy in stage Ib-IIa cervical carcinoma patients who had pelvic node metastases after radical hysterectomy, a single institutional randomized controlled trial with factorial design, comparing concurrent chemo-radiotherapy (CT + RT) versus chemotherapy (CT) or radiotherapy (RT) alone was conducted. Study endpoints included site of recurrence, time to recurrence, relapse-free and overall survivals, and toxicity of treatment.

RESULTS

At a median follow-up of 61 months, the 6-year relapse-free and overall survival rates of the 39 patients entered into this trial were 78.2% and 85.2%, respectively. This trial was prematurely closed due to suboptimal accrual and protocol violation. It is inconclusive regarding the efficacy of CT because of the limitation of the sample size and the imbalance of prognostic features by actual treatment. A model for risk group classification of patients with stage Ib-II cervical carcinoma with pelvic node metastases from a retrospective analysis was validated by this prospective cohort. The results of this failed trial suggest that adjuvant CT alone seemed comparable to RT alone or CT + RT in survival but was associated with significantly less morbidity.

CONCLUSION

It is warranted to consider a CT alone arm in comparison with either observation or CT + RT according to risk of recurrence in future prospective trials. However, this important issue can only be addressed by a large multicenter trial.

NGF-induced cytotoxicity in PC12 cells in a hypoglycemic environment

Surprisingly, we observed that nerve growth factor (NGF) potentiated death of PC12 cells induced by glucose withdrawal, although NGF is widely believed to exert its protective role against several types of cell death. Since either glucose withdrawal or NGF treatment increases intracellular calcium levels of target cells in many cases, we hypothesized that further increase of intracellular calcium by NGF may be a determinant factor in the NGF-mediated cell death. To test this hypothesis, we examined the effect of NGF on cell death pharmacologically by measuring cell viability and traced the changes of intracellular calcium in various conditions using a confocal laser microscope. NGF promoted cell death under a glucose-deprived condition in a manner dependent on extracellular calcium, and nifedipine, but not ryanodine, could partially block the cell death. NGF treatment augmented further intracellular calcium that had been elevated by glucose withdrawal, the event that nifedipine could block. In this study, therefore, we tentatively concluded that NGF potentiates cell death of starved PC12 cells by accelerating the initial increase of intracellular calcium through activation of a dihydropyridine-sensitive calcium channel.

Aldosterone stimulates Na,K-ATPase activity in basolateral membrane of rat kidney

The changes of Na,K-ATPase activity and its regulation have been investigated in the renal cortex and its basolateral membrane of aldosterone-induced hypertensive rat. Ouabain-sensitive Na,K-ATPase activity and [3H]ouabain-binding site (Bmax) in the hypertensive rat were significantly increased than those in the control. The levels of Na,K-ATPase alpha 1- and beta 1-subunit mRNA of the renal cortex in hypertensive rat were more increased than those in the control, and their increases were repressed by actinomycin-D. These results suggest that the increase of Na,K-ATPase activities and ouabain binding sites in aldosterone-induced hypertensive rat may be correlated with transcriptional regulation of Na,K-ATPase gene expression.

The prognostic significance of pre- and posttreatment SCC levels in patients with squamous cell carcinoma of the cervix treated by radiotherapy

PURPOSE

To investigate the prognostic significance of the pre- and posttreatment serum squamous cell carcinoma antigen (SCC) levels in patients with Stage I-IVA squamous cell carcinoma of the cervix primarily treated by radiotherapy.

MATERIALS AND METHODS

401 patients with squamous cell carcinoma of cervix primarily treated with radiotherapy (RT) were included in this study. All had preRT, and 249 patients had postRT serum SCC values. The association of pretreatment SCC level with the clinical parameters, including stage, hemoglobin (Hb) level, age, cell differentiation, and lymph node status, was assessed by univariate and multivariate analysis. The prognostic significance of pretreatment SCC level and these clinical parameters were evaluated. The impact of postRT residual induration and SCC levels on survival was analyzed.

RESULTS

1. PreRT SCC level strongly correlated with stage. After controlling for stage, only SCC levels higher than 10 ng/ml were associated with enlarged lymph nodes shown in CT scan. No association of preRT SCC level with other clinical parameters was found. 2. SCC level higher than 10 ng/ml, but not between 2-10 ng/ml, had significant impact on survival in a multivariate analysis. Stage, Hb levels (<10 g/dl) and positive lymph node shown by CT scan were also independent prognostic factors for survival. No significant difference in failure pattern in terms of local and/or distant sites was found in patients with different SCC levels. 3. Patients with residual induration and/or persistently elevated SCC level at 2-3 months after RT had a significantly higher incidence of treatment failure. Persistently elevated SCC level is a stronger predictor for treatment failure than residual induration by pelvic examination, and is associated with a higher incidence of distant metastasis. One third of patients with initial SCC level higher than 10 ng/ml had persistently elevated SCC.

CONCLUSION

Pretreatment SCC levels higher than 10 ng/ml are an independent predictor for poor prognosis in patients included in this study, and can be used as one of the prognostic factors for selection of patients for intensive treatment. Persistently elevated SCC levels after RT is a strong predictor for treatment failure. A combination of clinical pelvic examination and SCC levels provides useful information for the need of further work-up and management.

Current status of anti-HBV chemotherapy

In the past decade, significant progress has been achieved in the battle against hepatitis B virus. In addition to the immunomodulating agents such as interferon-alpha and thymosin, many novel antiviral agents have been discovered, among which nucleoside analogues are the mainstay. New-generation compounds such as 3TC and famciclovir have shown promise in the treatment of patients chronically infected by this virus, and are on the line for approval. However, viral rebound after cessation of therapy still remains a major problem. Additionally, the reports on the drug resistance to these antiviral agents suggest that combination therapy will be the eventual strategy (Bartholomew et al., 1997; Tipples et al., 1996). Therefore, developments of safe and effective antiviral agents which do not cross-resist with currently available antiviral drugs are still much needed.

Diabetes mellitus after renal transplantation: as deleterious as non-transplant-associated diabetes?

BACKGROUND

Despite use of lower doses of corticosteroid hormones after renal allotransplantation in the era of cyclosporine and tacrolimus, posttransplant diabetes mellitus remains a common clinical problem.

METHODS

We prospectively investigated the effect of posttransplant diabetes on long-term (mean follow-up, 9.3+/-1.5 years) graft and patient survival in the 11.8% of our renal transplant population (n = 40) who developed diabetes after kidney transplantation, and we compared outcome in 38 randomly chosen nondiabetic control patients who had received transplants concurrently.

RESULTS

Twelve-year graft survival in diabetic patients was 48%, compared with 70% in control patients (P = 0.04), and Cox's regression analysis revealed diabetes to be a significant predictor of graft loss (P = 0.04, relative risk = 3.72) independent of age, sex, and race. Renal function at 5 years as assessed by serum creatinine level was inferior in diabetic patients compared to control patients (2.9+/-2.6 vs. 2.0+/-0.07 mg/dl, P = 0.05). Two diabetic patient who experienced graft loss had a clinical course and histological features consistent with diabetic nephropathy; other diabetes-related morbidity in patients with posttransplant diabetes included ketoacidosis, hyperosmolar coma or precoma, and sensorimotor peripheral neuropathy. Patient survival at 12 years was similar in diabetic and control patients (71% vs. 74%).

CONCLUSIONS

Posttransplant diabetes mellitus is associated with impaired long-term renal allograft survival and function, complications similar to those in non-transplant-associated diabetes may occur in posttransplant diabetes, and, hence, as in non-transplant-associated diabetes, tight glycemic control may also be warranted in patients with posttransplant diabetes.

Effects of IL-3 gene expression on tumor response to irradiation in vitro and in vivo

Expression of a murine interleukin 3 gene in murine fibrosarcoma cells (FSA-JmIL-3) did not alter their survival after in vitro irradiation. However, FSA-JmIL-3 tumors established in vivo were much more sensitive to irradiation than was the parental tumor. Following 25 Gy of irradiation, parental fibrosarcoma tumors regrew after a growth delay of 10 days, but FSA-JmIL-3 tumors continued to regress. Examination of the cellular composition of tumors following irradiation revealed that, instead of tumor cell repopulation, the FSA-JmIL-3 tumors became heavily infiltrated with lymphocytes, indicating that the effect of irradiation was to allow the IL-3-elicited cellular immune response to infiltrate the tumors and mediate rejection. This study indicates that combining gene immunotherapy approaches with radiotherapy might increase the effectiveness of both, and it seems logical to pursue such treatment options.

Induction of c-fos and junB mRNA following in vivo brain irradiation

Although radiotherapy is a front line treatment for brain tumors, little is known about the in vivo molecular responses of brain to irradiation. In this study, expression of c-fos, c-jun and junB immediate-early genes were followed in mouse brain after irradiation. C-fos and junB, but not c-jun, mRNA was induced within 15 min in unanesthetized irradiated mice. Induction was transient and lasted < 4 h. The response was dose-dependent with increases in c-fos and junB mRNA levels after dose of > or = 2 and 7 Gy, respectively. Anesthesia of mice with pentobarbitol delayed the increases in mRNA expression and the response was attenuated. Pre-treatment of mice with dexamethasone, in a schedule which suppressed acute-phase gene expression after brain irradiation, did not significantly change c-fos and junB induction. Our results show that c-fos and junB responses occur in the brain in response to irradiation and that they can be modified by pentobarbital treatment but suggest that there is no direct correlation between the level of mRNA expression and later expression of cytokines or other acute-phase response genes.

Nonmechanical image rotation with an acousto-optic dove prism

We report what we believe to be the first method for nonmechanical and programmable image rotation. The method uses a pair of crossed acousto-optic beam deflectors and a polygon mirror to emulate the mechanical dove prism. It is capable of fast (of the order of microseconds) image rotation to an arbitrary angle in a programmable manner. An experimental result that proves the concept is provided.

Delayed molecular responses to brain irradiation

The chance of life-threatening complications occurring late after brain irradiation limits the efficacy of this form of cancer therapy. The molecular and cellular events that trigger radiation-induced brain damage are still unknown, but since they have the potential to serve as valuable targets for therapeutic intervention they are worth delineating. In this murine study, the effect of irradiation on the expression of molecules which are known to contribute to brain damage in other model systems was examined. Expression of genes encoding cytokines (TNF-alpha/beta, IL-1 alpha/beta, IL-2, IL-3, IL-4, IL-5, IL-6 and IFN-gamma), cytokine receptors (TNF-Rp55 and p75, IL-1R- p60 and p80, IFN-gamma R, and IL-6R), the cell adhesion molecule (ICAM-1), inducible nitric oxide synthetase (iNOS), anti-chymotrypsin (EB22/5.3), and the gliotic marker (GFAP) was evaluated over a 6-month period using a sensitive RNase protection assay (RPA). We had previously demonstrated that within 24 h of brain irradiation there is an acute transitory molecular response involving TNF-alpha, IL-1, ICAM-1, EB22/5.3 and GFAP. This study shows re-elevation of TNF-alpha, EB22/5.3 and GFAP mRNA levels at 2-3 months, but only TNF-alpha mRNA was overexpressed at 6 months. These time points are when neurological abnormalities are seen after higher doses. The data suggest that TNF-alpha may be involved in late brain responses to irradiation and could contribute to clinical symptoms.

A randomized trial of concurrent chemoradiotherapy versus radiotherapy in advanced carcinoma of the uterine cervix

The purpose of our study was to determine whether the chemoradiation is better than radiotherapy alone with respect to survival and treatment toxicity in patients with advanced carcinoma of the cervix. From October 1990 to April 1995, a total of 122 patients with advanced cervical carcinoma were included in this study and randomly assigned to either radiotherapy or concurrent chemotherapy and radiotherapy. The patients in the concurrent group received cisplatin, vincristine, and bleomycin every 3 weeks for a total of four courses, in combination with radiotherapy concurrently. Sixty patients were randomized to the concurrent chemoradiotherapy, and 62 were randomized to the radiotherapy alone. A tumor response was observed in 88.3% of the patients in concurrent group and in 74.2% of the patients in radiotherapy group (P = 0.04). After a median follow-up of 46.8 months, the overall disease-free survival and actuarial survival rate at 3 years were 51.7 and 61.7% in the concurrent group, and 53.2 and 64.5% in the radiotherapy group, respectively. Treatment-related toxicity appears to be higher with the combination of radiotherapy and chemotherapy compared with radiotherapy alone (36.7% versus 17.7%, P = 0.02). However, analysis by Kaplan-Meier method showed that the actuarial survival was not statistically different between the chemoradiotherapy and radiotherapy groups (mean survival time: 38.1 months versus 41.5 months, P = 0.27). In conclusion, this study showed that concurrent multiagent chemoradiotherapy did not prove to be a superior definitive therapy over radiotherapy alone for patients with advanced cervical carcinoma.

Unemployment in inner-city renal transplant recipients: predictive and sociodemographic factors

Studies of dialysis patients report unemployment rates of 60% to 75%; however, it is generally believed that following transplantation, improvement in well-being and removal of time constraints imposed by the dialytic regimen afford improvement in employment status. We studied 58 stable renal transplant recipient attending an outpatient transplant clinic by questionnaire, administered anonymously. Only 25 (43%) of the patients were currently employed. Employed and unemployed patients did not differ when compared for age, gender, race, cause of renal disease, type of transplant or prior dialysis, time on dialysis or time since transplantation, years of education, or prestige score or classification ("blue collar" v "white collar") of prior job. In the employed group, 24 (96%) patients had worked before developing kidney disease compared with 23 (70%) patients in the unemployed group (P < 0.05). While on dialysis, 19 (79%) of the employed patients continued working compared with 10 (30%) of the unemployed patients (P < 0.005). Major reasons for discontinuing work after starting dialysis for both groups were subjective illness (feeling too sick, 51%), followed by interference of the dialysis regimen with time necessary for work (32%). Only 15% of the previously employed patients did not work after transplantation because of feeling too sick. By multiple logistic regression, the strongest predictors of employment posttransplant were being more than 1 year posttransplant (odds ratio, 2.35; 95% confidence interval, 1.01 to 5.5) and having been employed before transplantation (odds ratio, 3.79; 95% confidence interval, 1.60 to 9.02). Over half of the unemployed patients (20 [61%]) expressed interest in job training. Eighty percent to 90% of patients in both groups were insured by Medicare, with the second greatest number insured by Medicaid. Of the 15 unemployed patients insured by Medicaid, 67% reported that their decision not to work was related to fear of losing Medicaid benefits because they could not afford medications without it. Despite no difference in actual type of insurance carried, 17 (51%) of the unemployed patients believed their health insurance coverage was inadequate compared with four (12%) of the employed patients (P = 0.005, chi-squared test). Unemployment remains a significant problem for our population of inner-city renal transplant recipients. Attention to job retention or retraining during the early renal disease and dialysis therapy period may promote better rehabilitation following transplantation. However, for this population, with limited employment opportunities, removal of disincentives to work, including loss of Insurance and Inability to pay for medications, will be necessary before we can provide optimal rehabilitation for renal transplant recipients from all social strata.

dl-propranolol negatively regulates the transcription of proliferating cell nuclear antigen (PCNA)-gene and thereby suppresses DNA synthesis in regenerating rat liver

Previous reports have suggested that dl-propranolol (PRL) suppresses DNA synthesis by blocking cAMP-mediated signaling in rat liver after partial hepatectomy (PH). Here, we examined if PRL negatively regulates the expression of genes involved in cell cycle progression. Immunoblotting assays showed that the protein levels of cyclins A and E, Cdk2, p21WAF1, and p27KIP1 did not significantly change in liver tissues from either vehicle- or PRL-injected rats after PH. However, the levels of PCNA and PCNA-mRNA markedly decreased in the remnant liver in response to PRL-injection. Similarly, PCNA-CRE binding activity of nuclear 43kDa CREB was suppressed, although the protein levels were not altered. We suggest that PRL negatively regulates the PCNA-gene transcription by interfering with the cAMP/PKA-mediated induction of CREB binding to the CRE-sequences and thereby suppresses DNA synthesis in regenerating rat liver.

Biomechanical evaluation of anterior and posterior fixations in an unstable calf spine model

STUDY DESIGN

Fresh calf lumbar spines were used to perform flexibility tests in multiple loading directions to compare the stabilizing effects of anterior and posterior rigid instrumentations.

OBJECTIVE

To compare the biomechanical flexibility of anterior and posterior instrumentation constructs using an unstable calf spine model.

SUMMARY OF BACKGROUND DATA

Unstable burst fractures of the thoracolumbar spine can be managed anteriorly or posteriorly. Controversy persists, however, on the merit of anterior fixation versus that of posterior fixation in terms of how much stability can be achieved.

METHODS

Fifteen fresh calf spines (L2-L5) were loaded with pure unconstrained moments in flexion, extension, axial rotation, and lateral bending directions. After removal of L3-L4 disc and endplates to create an 1.5-cm anterior and middle column defect, testing was performed on five specimens after anterior Kaneda rod fixation, anterior University Plate fixation, or posterior ISOLA pedicle screw fixation (AcroMed, Cleveland, OH). Testing was repeated after inserting a polymethylmethacrylate block to stimulate an interbody anterior graft with instrumentation.

RESULTS

All fixation devices provided a significant stabilizing effect in flexion and lateral bending. In extension, all constructs except ISOLA (AcroMed) without graft were stiffer than the intact specimen. In axial rotation with no graft, only the Kaneda device significantly reduced the flexibility from that of the intact specimen. The interbody graft provided additional rigidity to the ISOLA (AcroMed) instrumentation construct in flexion and extension and to the Kaneda construct in lateral bending. There was no significant effect of grafting in axial rotation.

CONCLUSIONS

A short, transpedicular instrumentation, such as ISOLA (AcroMed), provided less rigid fixation in flexion and extension without the anterior structural graft. The Kaneda rod and University plate with grafting provided a significant stabilizing effect in all directions compared with the intact specimen. When no graft was inserted, the Kaneda device was more effective in preventing axial rotation than the other devices. In lateral bending, the University plate provided more rigid fixation than the Kaneda device without grafting.

Nasopharyngeal adenoid cystic carcinoma: five new cases and a literature review

OBJECTIVE

Nasopharyngeal adenoid cystic carcinoma (NACC) is a rare tumour, and its mainstay treatment is different from adenoid cystic carcinoma arising from another head and neck region. In this study, we analyzed 20 cases of NACC with complete clinical information, 5 from Chang Gung Memorial Hospital and 15 from the literature review.

RESULTS

The time interval between first symptom and treatment ranged from 2 weeks to 8 years, with a median of 24 months. Compared with usual nasopharyngeal carcinoma, NACC has higher incidence of cranial nerve involvement (55%) and lower incidence of cervical adenopathy (15%). All patients were treated by radiotherapy and 6 patients received surgical treatment. The 5- and 10-year overall survival rates were 78% and 49.5%, respectively. Seven patients developed metastasis to lung or bone. After a minimum of 5 years' follow-up, the local control rate was 45.5% in patients receiving radiation dose > 70 Gy, and 28.6% in those receiving dose < or = 70 Gy, suggesting higher radiation dose is necessary to achieve better local control in NACC.

The role of brachytherapy in early-stage nasopharyngeal carcinoma

PURPOSE

To present the treatment results and assess the optimal radiation dose and the role of brachytherapy in early stage nasopharyngeal cancer (NPC).

METHODS AND MATERIALS

One hundred eighty-three patients with Stage I and II (American Joint Committee on Cancer Staging System, 1987) NPC completed the planned radiotherapy in our institution from 1979 to 1991. In 133 patients, radiotherapy was given to the nasopharynx by external beam to 64.8-68.4 Gy. Further boost was done by high dose rate (HDR) brachytherapy for 5-16.5 Gy in one to three fractions. For the remaining 50 patients, a course of external radiotherapy to the nasopharynx for 68.4-72 Gy was given to nasopharynx. Age (>40 or not), sex, neck boost or not, brachytherapy, and irradiation dose were analyzed to determine significant factors that influence the probabilities of local control and actuarial survival.

RESULTS

The 5-year disease-specific survival was 85.8% and local control was 83%. Only the brachytherapy and irradiation dose significantly affected the results. The use of the brachytherapy had significant impact on overall survival and local control. Furthermore, we compared the prognostic effect of various radiation dosage among Group I of 50 patients (<72.5 Gy, no brachytherapy, excluding four patients who received brachytherapy), Group II of 71 patients (72.5-75 Gy; one to two fractions of brachytherapy), and Group III of 58 patients (>75 Gy; three fractions of brachytherapy). Five-year disease-specific survival rates of Group I, Group II, and Group III were 77, 95.5, and 82.4%, respectively. Five-year local control rates were: 73.7, 93.9, and 79.5%. We found that the Group II had the best actuarial survival and local control rate (log-rank test,p < 0.05). Most patients receiving brachytherapy encountered foul odor because of nasopharynx crust; 12 of them had palate or sphenoid sinus floor perforation or nasopharynx necrosis. None of the patients without brachytherapy experienced the same complications.

CONCLUSIONS

The optimal radiotherapy dose to the nasopharynx area in early stage NPC may be within 72.5 to 75 Gy by our treatment protocol. A dose of more than 75 Gy did not have significant local control or survival advantage. The use of brachytherapy to elevate radiation dose had significant local control and survival benefit for early stage NPC patients, but the fractionation size should be decreased to reduce the complications.

Biomechanics of transfixation in pedicle screw instrumentation

STUDY DESIGN

The biomechanical role of transfixation in pedicle screw instrumentation was investigated using flexibility tests and finite element analyses.

OBJECTIVE

To assess the stabilizing effect of use and position of transfixators.

SUMMARY OF BACKGROUND DATA

Transfixation is common in pedicle screw instrumentation, however, its biomechanical role and optimal position are not completely understood.

METHODS

Specimens underwent nondestructive flexibility tests using a three-dimensional motion analysis system. Tests compared the intact spine with instrumentation with and without transfixators Rotational angles of the superior vertebra, resulting from the maximum moment of 6.4 Nm, were compared. Three-dimensional finite element models investigated transfixator position. Rotations of the superior vertebra were compared for cases with and without transfixators to determine the position providing the greatest stability.

RESULTS

Biomechanical test showed that only axial rotational stability significantly improved with transfixators compared with instrumentation alone. Pimte element models predicted improvement in lateral bending and axial rotation with transfixators compared with the case with no transfixator. With one transfixator, the greatest improvement in axial rotation stability occurred with the transfixator at the proximal 1/4 position of the rods. When two transfixators were used, the optimal locations were with one transfixator in the middle and the second at the proximal 1/8 position.

CONCLUSIONS

Transfixators improved the stabilizing effects of pedicle screw instrumentation. The greatest axial rotation stability was obtained with two transfixators; one in the middle and the other at the proximal 1/8 position of the longitudinal rods.

Apoptosis and delayed expression of c-jun and c-fos after gamma irradiation of Jurkat T cells

The purpose of this study was to determine the role of radiation-induced expression of c-jun and c-fos in radiation-induced apoptosis of cells of the Jurkat T-cell line. Doses of 10-20 Gy caused a massive number of cells to undergo apoptosis within the first 24 h. This was accompanied by extensive increases in c-jun mRNA levels and moderate increases in c-fos levels, both occurring at the time of onset of internucleosomal DNA fragmentation. Increased c-jun and c-fos expression was maximum at 8 h after irradiation with a 10-fold increase in c-jun and a 2-fold increase in c-fos mRNA levels. In comparison, stimulation of the Jurkat cells with PMA resulted in rapid induction of c-jun and c-fos within 1 h. The late induction of c-jun and c-fos was not preceded by induction of tumor necrosis factor-alpha (TNF-alpha) or the bifunctional repair endonuclease and nuclear redox factor Ref-1; rather a slow decrease in Ref-1 mRNA levels was found over the first 24 h. Our results showed that radiation-induced c-jun and c-fos expression is a late response in Jurkat cells, and is most likely a secondary effect not necessary for radiation-induced apoptosis. Furthermore, apoptosis was induced by the RNA synthesis inhibitor actinomycin D, which does not induce c-jun or c-fos expression. This demonstrates that massive late induction of c-jun and c-fos is not a general requirement for apoptosis in Jurkat cells.

Near-infrared diffuse reflectance spectroscopic analysis of the amounts of moisture, protein, starch, amylose, and tannin in buckwheat flours

The feasibility of near-infrared (NIR) diffuse reflectance spectroscopy scanning from 1100 to 2500 nm in the analyses of the amounts of moisture, protein, starch, amylose, and tannin in buckwheat flours was examined. Fifty ground samples comprised of 27 different cultivars harvested in 12 different countries were divided into two sets: 35 samples as a calibration set and 15 samples as a prediction set. The multiple regression equations (MREs) established between the second derivative NIR spectra data and the reference data, which were obtained by chemical analyses of the calibration set, gave multiple correlation coefficients of higher than 0.93 for moisture, protein, and starch, and workable standard error of predictions (SEPs) in relation to the reference standard deviation data. In contrast, the MREs for amylose and tannin were judged as unstable because the SEPs had no difference with their reference standard deviation data. The influential wavelengths were 1925 nm for water (assigned to the combination of the stretching and bending vibrations of hydroxyl [OH]), 2057 nm for protein (assigned to the combination of NH and amide II or III), and 2100 nm for starch (assigned to the combination of OH and CO). The obtained results indicated that the NIR procedure can be used as a nondestructive analysis method for rapid and simple measurement of the amounts of moisture, protein, and starch in buckwheat flours.

Compact holographic storage demonstrator with rapid access

We discuss the design of a complete, compact holographic storage demonstrator based on a combination of spatial and angular multiplexing and using acousto-optic deflectors for rapid nonmechanical access. We also describe the implementation of this design and preliminary results of both the analog storage and the retrieval of 20,000 holograms in twenty 1-mm-thick layers of a lithium niobate crystal and of the digital storage and error-free retrieval of color images by using error-correcting techniques.

The effect of kidney size on cadaveric renal allograft outcome

Chronic rejection is the commonest cause of long-term renal allograft loss. Though immunologic factors are thought dominant in its pathogenesis, nonimmunologic factors, in particular, hyperfiltration damage related to reduced renal mass, have also been proposed as factors in the causation of chronic allograft rejection. We assessed the influence of renal size on graft survival and function in all cyclosporine-treated cadaver donor adult renal allograft recipients engrafted at a single center between June 1989 and July 1994, whose grafts functioned for > or = to 3 months (n=169). Patients were divided into 4 groups based on the ratio of kidney volume to recipient body surface area (volume/BSA) (ml/m2), and outcome in groups compared by methods including Cox's proportional hazards and Kaplan-Meier analysis. No significant differences between groups existed for serum creatinine levels, presence of significant proteinuria, or 1- and 5-year graft survival. There was no correlation between volume/BSA and either serum creatinine or degree of proteinuria at 3, 6, 12, 36, and 60 months posttransplant. Volume/BSA was similar in patients with good or poor renal function (58 +/-21 vs. 56 +/- 28 ml/m2), with or without significant proteinuria (57 +/- 24 vs. 60 +/- 25 ml/m2) or in patients who lost their grafts to chronic rejection compared with those with stable allograft function (64 +/- 34 vs. 59 +/- 24 ml/m2). Volume/BSA was not a predictor of graft survival on multivariate regression. We conclude that donor kidney size has no apparent effect on cadaveric renal allograft outcome in the short and intermediate-term, suggesting that close matching of donor kidney size to recipient size is not presently indicated.

Induction of acute phase gene expression by brain irradiation

PURPOSE

To investigate the in vivo acute phase molecular response of the brain to ionizing radiation.

METHODS AND MATERIALS

C3Hf/Sed/Kam mice were given midbrain or whole-body irradiation. Cerebral expression of interleukins (IL-1 alpha, IL-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6), interferon (IFN-gamma), tumor necrosis factors (TNF-alpha and TNF-beta), intercellular adhesion molecule-1 (ICAM-1), inducible nitric oxide synthetase (iNOS), von Willebrand factor (vWF), alpha 1-antichymotrypsin (EB22/5.3), and glial fibrillary acidic protein (GFAP) was measured at various times after various radiation doses by ribonuclease (RNase) protection assay. The effects of dexamethasone or pentoxifylline treatment of mice on radiation-induced gene expression were also examined.

RESULTS

Levels of TNF-alpha, IL-1 beta, ICAM-1, EB22/5.3 and to a lesser extent IL-1 alpha and GFAP, messenger RNA were increased in the brain after irradiation, whether the dose was delivered to the whole body or only to the midbrain. Responses were radiation dose dependent, but were not found below 7 Gy; the exception being ICAM-1, which was increased by doses as low as 2 Gy. Most responses were rapid, peaking within 4-8 h, but antichymotrypsin and GFAP responses were delayed and still elevated at 24 h, by which time the others had subsided. Pretreatment of mice with dexamethasone or pentoxifylline suppressed radiation-induced gene expression, either partially or completely. Dexamethasone was more inhibitory than pentoxifylline at the doses chosen.

CONCLUSIONS

The initial response of the brain to irradiation involves expression of inflammatory gene products, which are probably responsible for clinically observed early symptoms of brain radiotherapy. This mechanism explains the beneficial effects of the clinical use of steroids in such circumstances.

Photorefractive integrator characterization

We describe the recent results of our efforts to characterize a photorefractive crystal to be used as a time-integrating device in an optically implemented null-steering adaptive processor for phased-array radar. We review frequency response data for the Bi(12)SiO(20) crystals, measured with an acousto-optic apparatus, and we present measured dynamic range data for the candidate Bi(12)SiO(20) crystals.

Fast reconfigurable optical image switching/routing system

A novel system that is capable of switching/routing two-dimensional images in arbitrary configurations is described. The switching network can be reconfigured in a few microseconds with high light efficiency.

Biomechanical evaluation of anterior thoracolumbar spinal instrumentation

STUDY DESIGN

A biomechanical study was designed to assess relative construct stabilities of modern anterior thoracolumbar instrumentations in a calf spine model with an anterior and middle column defect.

OBJECTIVES

The purpose is to compare the biomechanical stability of various anterior fixation devices in an unstable calf spine model.

SUMMARY OF BACKGROUND DATA

Modern types of anterior thoracolumbar instrumentations evolved to either rods or plates. Biomechanical properties and comparative studies of these instrumentations are lacking.

METHODS

Twenty fresh calf spines (L2-L5) were used for the biomechanical tests. L2 and L5 vertebrae were used to attach the loading and base frames, respectively. Specimens underwent nondestructive biomechanical tests performed using a three-dimensional motion measuring system. In each specimen, three different cases were tested: intact spine, anterior fixation with an interbody graft after total discectomy and endplate excision of L3-L4 disc, anterior fixation only without the graft. Four anterior fixators, University Anterior Plating System, the Kaneda device, the Z-plate, and Texas Scottish Rite Hospital system were used. Each device was tested on five specimens. A polymethylmethacrylate block was inserted into the disc space to simulate the interbody grafting, and a fixation device was implanted with axial compression. Rotational angles of the L3-L4 segment stabilized by a fixation device and graft were normalized by the corresponding angles of the intact specimen to study the overall stabilizing effects.

RESULTS

With the interbody graft and fixation devices, all showed significant stabilizing effects in flexion, extension, and lateral bending. All devices restored axial rotation stability to intact specimen, but only the Kaneda device restored the torsional stability beyond the intact specimen. No statistical differences in stabilizing effects in axial rotation were found between any of the tested devices. When the graft was removed, the Kaneda device significantly decreased the motions in all directions compared with the intact motion, whereas the University plate decreased the motions in flexion, extension, and lateral bending. The Texas Scottish Rite Hospital system was found to reduce the flexion and lateral bending motions significantly, and Z-plate decreased lateral bending motions only. Stabilizing effects of the interbody graft were significant in lateral bendings for all devices. Additionally, the significant stabilizing role of the graft was noted in flexion and extension in Z-plate only. The graft did not significantly reduce the axial rotation motion in any instrumentations.

CONCLUSIONS

Modern anterior instrumentations for the thoracolumbar spine, such as the Kaneda device, Texas Scottish Rite Hospital system, Z-plate, and University plate, restored the stability in all motions when an interbody graft was inserted. The stability of fixation devices revealed that the Kaneda device is the best, particularly in restoring the torsional stability. The information on the relative stability provided by different instrumentations should help the spine surgeon in choosing the appropriate instrumentation for the particular circumstance.

Modification of tumor microenvironment by cytokine gene transfer

The tumor microenvironment is determined by the interactions between host and tumor cells, a process in which cytokines play a major role. We have used retroviral vectors to insert and express cytokine genes in tumor cells so as to induce predictable changes in the host cells that infiltrate tumors. This frequently caused changes in tumor cell phenotype through autocrine/intracrine pathways. We reasoned that cytokine-induced alterations in tumor cell phenotype and/or in infiltrating host cells might alter the in vitro and in vivo cellular response to irradiation. In the present paper we document some of the effects of expression of interleukin-6 (IL-6) and IL-7 genes in tumor cells in this regard. The studies support the hypothesis that cytokines may play a role in determining both intrinsic tumor radioresponsiveness and the tumor microenvironment and in these ways may influence in vivo tumor irradiation responses. Possible cytokine gene-mediated approaches to radiotherapy cancer are discussed.