A novel unconventional antigen MPD5 elicits anti-tumor humoral immune responses in a subset of patients with polycythemia vera

In an effort to define the antigenic mechanism that contributes to beneficial therapeutic outcome in patients with polycythemia vera (PV), we screened a human testis cDNA library with serological cloning derived from sera of three PV patients who had undergone therapeutic-induced remission. As a result, we identified a novel antigen, MPD5, which belongs to the group of cryptic antigens with unconventional genomic intron/exon structure. Moreover, MPD5 elicited IgG antibody responses in a subset of PV patients who had benefited from a variety of therapies--including IFN-alpha, Hydroxyurea, Imatinib mesylate, Anagrelide, and phlebotomy--but not in untreated PV patients or healthy donors, suggesting that MPD5 is a PV-associated, therapy-related antigen. In the granulocytes of PV patients who are responsive to therapy, upregulated MPD5 expression may serve to enhance immune responses. These findings provide new insight into the mechanism underlying regulation of the self-antigen repertoire that elicits anti-tumor immune responses in patients with myeloproliferative diseases, indicating the potential of these self-antigens as targets of novel immunotherapy.

New symptomatic compression fracture after percutaneous vertebroplasty at the thoracolumbar junction

BACKGROUND AND PURPOSE

The purpose of this study was to investigate the risk factors for new symptomatic vertebral compression fractures after vertebroplasty at the thoracolumbar junction.

MATERIALS AND METHODS

We conducted a retrospective analysis of 53 patients treated with percutaneous vertebroplasty at the thoracolumbar junction (T12, L1). The follow-up period was 15-27 months. The occurrence of new symptomatic vertebral compression fractures was recorded after vertebroplasty. We evaluated patient age and sex, amount of injected cement, vacuum clefts in the collapsed bodies, initial wedge angle of the compression fracture, change of the wedge angle after vertebroplasty, intradiskal cement leak, and percentage of height restoration of the vertebral body. In this report, we surveyed the possible risk factors for new symptomatic vertebral compression fractures.

RESULTS

Thirty-nine (74%) of the 53 patients had fluid and/or air in the compression fracture at the thoracolumbar junction (T12, L1). Eight (20.5%) of the 39 patients with vacuum clefts had new symptomatic compression fracture after vertebroplasty between 1 month and 4 days after surgery to 23 months and 4 days after surgery. The patients with new symptomatic compression fracture had higher initial wedge angle and wedge angle change (more than 7 degrees ) after vertebroplasty than those without fractures; these data were considered statistically significant.

CONCLUSIONS

The incidence of vacuum clefts in the compression fracture at the thoracolumbar junction is high (74%). The severity of initial wedge angle and wedge angle change affects the incidence of new symptomatic compression fracture.

HLA-A2.1-restricted T cells react to SEREX-defined tumor antigen CML66L and are suppressed by CD4+CD25+ regulatory T cells

The question of whether T cell responses to SEREX-defined tumor antigens are under regulation of naturally occurring CD4+CD25+ regulatory T cells (nTreg cells) has not been answered. To address this issue, we first identified an HLA-A2.1-restricted T cell antigen epitope of SEREX-identified tumor antigen CML66L, 66Pa. The HLA-A2.1/66Pa peptide complex in vitro stimulated the in vivo-primed T cells as shown by increased T cell proliferation, higher secretion of the T cell cytokine interferon-gamma (IFN-gamma), increased production of intracellular IFN-gamma in CD8+ T cells, and higher T cell-mediated cytotoxicities of CML66L+ human tumor cells. This suggests that CML66L elicits T cell immune responses. We also developed a novel internal reference epitope for identification of T cell epitopes by construction of chimeric CML66L containing myeloid antigen proteinase 3 epitope Pr1 as a control. Finally, we found that nTreg cells regulates T cell responses to 66Pa, and that depletion of nTreg cells via a pro-apoptotic protein Bax-dependent mechanism enhances polyclonal T cell responses to 66Pa. These findings provide new insights into the T cell participation in SEREX-defined anti-tumor immune responses and novel direction in enhancement of anti-leukemia immunotherapy by modulation of homeostasis of nTreg cells.

Processing sites are different in the generation of HLA-A2.1-restricted, T cell reactive tumor antigen epitopes and viral epitopes

In order to improve the processing efficiency of T cell tumor antigen epitopes, this bioinformatic study compares proteolytic sites in the generation of 47 experimentally identified HLA-A2.1-restricted immunodominant tumor antigen epitopes to those of 52 documented HLA-A2.1-restricted immunodominant viral antigen epitopes. Our results show that the amino acid frequencies in the C-terminal cleavage sites of the tumor antigen epitopes, as well as several positions within the 10 amino acid (aa) flanking regions, are significantly different from those of the viral antigen epitopes. In the 9 amino acid epitope region, frequencies differed somewhat in the secondary-anchored amino acid residues on E3 (the third aa of the epitope), E4, E6, E7 and E8; however, frequencies in the primary-anchored positions, on E2 and E9, for binding in the HLA-A2.1 groove, remained almost identical. The most frequently occurring amino acid pairs in both N-terminal and C-terminal cleavage sites in the generation of tumor antigen epitopes were different from those of the viral antigen epitopes. Our findings demonstrate for the first time that these two groups of epitopes may be cleaved by distinct sets of proteasomes and peptidases or similar enzymes with lower efficiencies for tumor epitopes. In the future, in order to more effectively generate tumor antigen epitopes, targeted activation of the immunoproteasomes and peptidases that mediate the cleavage of viral epitopes could be achieved, thus enhancing our potential for antigen-specific tumor immunotherapy.

The use of the GlideScope ® for tracheal intubation in patients with ankylosing spondylitis

BACKGROUND

The GlideScopeVideo Laryngoscope is a new intubating device. The aim of the study was to investigate the use of the GlideScopefor tracheal intubation in patients with ankylosing spondylitis (AS) undergoing general anaesthesia.

METHODS

Twenty AS patients were chosen to undergo tracheal intubation by the GlideScope. Preoperative airway assessments were carried out to predict the difficulty of tracheal intubation. Before intubation all patients were given a modified Cormack and Lehane (MCLS) grade and percentage of glottic opening (POGO) score by a separate anaesthetist using a Macintosh size 3 blade. The patients were then intubated, using the GlideScope, by a different anaesthetist during which the larynx was inspected and given another MCLS grade and POGO score.

RESULTS

Twelve of the AS patients were judged to have had difficult intubation by preoperative airway assessment. Eleven of the twelve patients had MCLS grades III or IV by direct laryngoscopy and were considered to have had a difficult laryngoscopy. Naso-tracheal intubations by the GlideScope were successful on 17/20 occasions, including 8 of the 11 difficult laryngoscopy. The GlideScope improved the MCLS grade and POGO score in the majority of AS patients compared with direct laryngoscopy (P<0.01).

CONCLUSIONS

The GlideScope provides a better laryngoscopic view than that of direct laryngoscopy. Most of the AS patients presenting with MCLS grade III or IV by direct laryngoscopy can be intubated successfully by the GlideScope. In elective patients with AS, awake fibreoptic intubation offers a higher level of security because it can be applied while maintaining spontaneous breathing. The use of GlideScope for tracheal intubation may be an alternative option in these patients who prefer their airway management under anaesthesia.

The role of glottal gap in predicting aspiration in patients with unilateral vocal paralysis

Aspiration has been frequently noted among patients suffering from vocal-fold paralysis. The association between a defect of glottal closure and aspiration in patients with unilateral vocal paralysis appears to have been rarely reported. The current study reviews collected data consisting of videotaped flexible nasoendoscopy and stroboscopy for patients with a unilateral vocal-fold paralysis. Mean normalized glottal gap areas for patients suffering vocal paralysis with associated aspiration are significant greater than that for the non-aspiration group. Subsequent to the surgical correction of the glottal gap, all patients recovered well from their earlier aspiration. The investigation of objectively derived data revealed that poor airway protection due to incomplete closure of the vocal fold was the major cause of aspiration for patients suffering unilateral vocal-fold paralysis. Intracordal autologous fat injection can successfully improve the breath control and eliminate aspiration in patients with vocal-fold paralysis.

Multimodal nonlinear spectral microscopy based on a femtosecond Cr:forsterite laser

We demonstrate a novel multimodal nonlinear spectral microscopy based on a femtosecond Cr:forsterite laser at 1230 nm. By acquiring the whole nonlinear spectrum in the visible and near-NIR region, this novel technique allows a combination of different imaging modalities, including second-harmonic generation, third-harmonic generation, and multiple-photon fluorescence. Combined with the selected excitation wavelength, which is located in the IR transparency window, this microscopic technique can provide high penetration depth with reduced damage and is ideal for studying living cells.

Occupational exposure to wood, formaldehyde, and solvents and risk of nasopharyngeal carcinoma

Our objective was to evaluate the link between occupational exposures to wood dust, formaldehyde, and solvents and the development of nasopharyngeal carcinoma (NPC). A case-control study was conducted among 375 newly diagnosed cases of NPC in Taipei, Taiwan, and 325 community controls matched to cases on sex, age, and geographical residence (99 and 87% response rates, respectively). Most cases (>90%) were diagnosed with WHO Types 2 or 3 (nonkeratinizing and undifferentiated carcinomas), whereas the remaining cases were diagnosed with WHO Type 1 (squamous cell carcinomas). A complete occupational history was obtained via a personal interview and blindly assessed by an industrial hygienist for intensity and probability of exposure to wood dust, formaldehyde, and solvents. Information on socio-demographic characteristics, cigarette smoking, dietary consumption of nitrosamines, and other potential confounding factors was obtained via a personal interview. Blood specimens were tested for human leukocyte antigen class I/II genotypes, polymorphisms in cytochrome P450 2E1 genotype, and various anti-EBV antibodies known to be associated with NPC. Analysis was performed using logistic regression; relative risk (RR) estimates and 95% confidence intervals (CI) were calculated. Individuals exposed to wood dust had an adjusted RR of 1.7 (95% CI = 1.0-3.0). Those exposed to wood dust for >10 years had an adjusted RR of 2.4 (95% CI = 1.1-5.0; p(trend) = 0.02). Risk was strongest for those first exposed before the age of 25 years and those seropositive to EBV. Individuals exposed to formaldehyde were at a more modest and nonsignificant increased risk of NPC (RR = 1.4; 95% CI = 0.93-2.2). Those exposed to formaldehyde for >10 years had an adjusted RR of 1.6 (95% CI = 0.91-2.9). The association between formaldehyde and NPC was stronger in analyses restricted to EBV seropositive individuals (RR = 2.7; 95% CI = 1.2-5.9). However, no dose response was observed with increasing duration or cumulative use. No association was observed between solvent exposure and NPC (RR = 1.2; 95% CI = 0.86-1.7). Occupational exposure to wood dust is likely to be involved in the development of NPC, a finding that is consistent with the known link between wood exposure and nasal adenocarcinomas. Formaldehyde exposure is less clearly linked to NPC, whereas exposure to solvents is unlikely to be involved in NPC pathogenesis.

Characteristics of mutations in the p53 gene in oral squamous cell carcinoma associated with betel quid chewing and cigarette smoking in Taiwanese

p53 mutations are etiologically associated with the development of oral squamous cell carcinomas (OSCCs) or are associated with exposure to specific carcinogens. In this study, we used PCR-single strand conformation polymorphism and DNA sequencing to analyze the conserved regions of the p53 gene (exons 5-9) in OSCC tumor specimens from 187 patients with varied histories of betel quid, tobacco and alcohol use. Ninety-one of the 187 OSCCs (48.66%) showed p53 gene mutations at exons 5-9. The incidence of p53 mutations was not associated with age, sex, TNM stage, status of cigarette smoking or betel quid chewing. However, alcohol drinkers exhibited a significantly higher incidence (57/101, 56.44%) of p53 mutations than non-users (39.53%, 34/86) (P = 0.02). The effect of alcohol on the incidence of p53 mutations was still statistically significant (RR = 2.24; 95% CI, 1.21-4.15) after adjustment for cigarette smoking and betel quid (BQ) chewing. G:C to A:T transitions were the predominant mutations observed and associated with BQ and tobacco use. Alcohol drinking could enhance these transitions. After adjustment for cigarette smoking and BQ chewing, alcohol drinking still showed an independent effect on G:C to A:T transitions (RR = 2.41; 95% CI, 1.01-5.74). These findings strongly suggest an important contributive role of tobacco carcinogens to p53 mutation in this series of Taiwanese OSCCs and alcohol might enhance these mutagenic effects. As safrole-DNA adducts have been detected in 77% (23/30) of the OSCC tissues from Taiwanese oral cancer patients with a BQ chewing history, we cannot rule out the possibility that safrole or other carcinogens present in the BQ may cause a similar pattern of mutagenesis. Determination of the role of safrole and other carcinogens present in BQ on the pattern of p53 gene mutation in OSCC will require further study.

Transpedicular wedge osteotomy for correction of thoracolumbar kyphosis in ankylosing spondylitis: experience with 78 patients

STUDY DESIGN

This is a retrospective study of surgical correction of thoracolumbar kyphosis caused by ankylosing spondylitis.

OBJECTIVE

To report the surgical results of thoracolumbar kyphosis deformity corrected with transpedicular wedge osteotomy performed by a single surgeon at a university hospital.

SUMMARY OF BACKGROUND DATA

There has not been a large series in the literature reporting on results of the Thomasen-type closing wedge osteotomy for correction of kyphosis deformity secondary to ankylosing spondylitis, nor has two-level osteotomy of this type in one patient ever been described.

METHODS

From 1991 through 1998, 92 transpedicular wedge osteotomies were performed in 78 patients with ankylosing spondylitis for correction of fixed flexion deformity of the thoracolumbar spine.

RESULTS

The mean amount of correction for each level of osteotomy was 34.5 degrees (range, 15 degrees -60 degrees ). The largest amount of overall correction for a single patient was 100 degrees. Most of the osteotomies (64 of 92) were done at L2 and L3. Fourteen patients with severe deformity required staged two-level osteotomy. Excellent and good results were obtained in 77 patients (98.7%) at the final follow-up. There was no mortality, nor were there any major neurological complications.

CONCLUSIONS

Transpedicular wedge osteotomy can effectively and safely correct kyphotic deformity of the thoracolumbar spine caused by ankylosing spondylitis, regardless of rigidity of the spinal curves. Two-level osteotomy can provide sufficient correction for severe cases.

Use of bacterially expressed EBNA-1 protein cloned from a nasopharyngeal carcinoma (NPC) biopsy as a screening test for NPC patients

EBV serological tests have been used for many years as accessory diagnostic predictors of nasopharyngeal carcinoma (NPC). To increase the sensitivity and specificity of the NPC detection rate, a novel enzyme-linked immunosorbent assay (ELISA) was established using a bacterially-expressed GST-EBNA-1 protein, containing the EBNA-1 sequence cloned from an NPC patient. Serum samples were collected from age- and gender-matched patients with NPC, community control subjects and hospital control patients and tested using this ELISA. The positivity rates were 78.7% (247/314) in NPC, 11.5% (28/244) in hospital controls and 3.8% (10/263) in the community control group. These serum samples were also tested for IgA anti-VCA antibodies and their ability to neutralize EBV DNase and the sensitivities of the anti-VCA antibody and DNase-neutralization tests also were analyzed. The optimum combination is VCA plus EBNA-1, which can identify 92.5% (287/310) of NPC patients, and shows a specificity of 92.7% (242/261) for normal individuals.

Poor prognosis in nasopharyngeal cancer patients with low glucose-6-phosphate-dehydrogenase activity

Nasopharyngeal carcinoma (NPC) is endemic among well-defined ethnic groups in several world regions, such as Southeastern China and Taiwan. Glucose-6-phosphate-dehydrogenase (G6PD)- deficiency, a sex-linked disorder, is one of the most common enzymopathies in Taiwan. The major role of G6PD is to generate NADPH to protect cells from oxidative damage, which is a major contributing factor to certain degenerative diseases, such as aging and cancer. In view of the coincidence of epidemic distribution of NPC and G6PD deficiency, as well as the house-keeping function of G6PD in cellular oxidative defense, we investigated the correlation of G6PD activity with NPC. The stage of NPC was classified by AJCC (1997) criteria. G6PD levels were determined in 108 NPC male patients and 75 healthy male individuals. The mean G6PD level of NPC patients was 218.9 U/10(12) RBC or 7.53 U/g hemoglobin (Hb), being much lower than in normal individuals (260.6 U/10(12) erythrocytes (RBC) or 8.92 U / gHb). The level of G6PD activity had no correlation with tumor stage or lymph node or distant metastasis, but was significantly correlated with tumor recurrence (P = 0.004 when using G6PD = 130 U/10(12) RBC as cutoff value). These results indicated that low G6PD activity in patients with NPC is associated with poor prognosis.

Intra-arterial plus i.v. chemotherapy for advanced bulky squamous cell carcinoma of the buccal mucosa

From July 1994 to December 1996, 41 patients with previously untreated, advanced bulky squamous cell carcinoma arising from the buccal mucosa (BSCC) were enrolled. All patients were males with a median age of 47 years (range 29-72). The tumor extent was stage III/IV: three of 38, T4: 85%, N2-3: 20%. Patients were initially scheduled to receive intra-arterial (i.a.) chemotherapy, followed by i.v. chemotherapy and regional therapy. The i.a. chemotherapy catheter was properly placed by external carotid artery angiography via the femoral artery. The i.a. chemotherapy consisted of cisplatin (P) 100 mg/m(2) day 1 plus 5-fluorouracil (F) 1000 mg/m(2) day 1-4, and the i.v. chemotherapy consisted of PF (10 patients) or PF plus methotrexate 200 mg/m(2) day 15 and 22 (31 patients). All chemotherapy regimens were administered at 4-week intervals. The response rate of i.a. plus i.v. chemotherapy for the primary site was 85% (35 of 41) with 29% complete remission (CR) (12 of 41). The response and CR rates of neck nodes were 82% (14 of 17) and 41% (seven of 17), respectively. The combined overall response rate was 80% (33 of 41) with a 29% CR (12 of 41). Major toxicity from i.a. chemotherapy of WHO grade > or = 3 included: mucositis of infusion area (76%), hemialopecia (56%) and leukopenia (5%). Three neurologic complications of i.a. chemotherapy including one hemiparesis occurred. The median follow-up time was 47 months (range 36-66 months), and the overall survival and disease-free survival were both 34% (14 of 41). Four patients were cured with chemotherapy alone and eight patients (19.5%) were cured without surgical intervention. Using i.a. chemotherapy as a cytoreductive therapy followed by subsequent i.v. chemotherapy produces a high response rate and an encouraging degree of complete response rate in advanced bulky BSCC. However, toxicity management and catheter placement will need to be improved in order to better define the role of this therapy in advanced BSCC.

Presence of Epstein-Barr virus latent membrane protein 1 gene in the nasopharyngeal swabs from patients with nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is the most common head and neck malignancy in southeastern China and Taiwan. Early detection of the local disease followed immediately by proper treatment is essential to increase the cure and survival rates. Because every NPC tumor cell carries Epstein-Barr Virus (EBV) genomes, detection of EBV genomic DNA such as latent membrane protein 1 gene (LMP1) might indicate the presence of NPC. We developed a simple and noninvasive technique of nasopharyngeal swabbing to acquire nasopharyngeal cells for detecting the presence of EBV genome. The aim of this study was to investigate the feasibility and reliability of this technique.

METHODS

We collected nasopharyngeal cells by means of a nasopharyngeal swabbing technique and detected the presence of EBV LMP1 with polymerase chain reaction (PCR). Thirty-eight swab specimens were obtained from patients with NPC who were newly diagnosed or were just beginning radiotherapy. Two groups of control subjects were recruited, including 20 patients with other head and neck cancers and eight family members of the NPC patients. An additional group of 65 NPC patients were enrolled in the course of regular follow-up after definitive radiotherapy.

RESULTS

All of the samples yielded sufficient DNA for PCR amplification. Thirty-six of 38 NPC swab samples were positive for EBV LMP1, and all the control subjects had swab sample results negative for EBV. All five patients with suspected local recurrence exhibited positive EBV test results.

CONCLUSIONS

Demonstration of EBV LMP1 in the nasopharyngeal swab specimens detected NPC with a sensitivity of 94.7% and specificity of 100%. This study confirms the reliability and feasibility of nasopharyngeal swab in the predicting and screening of NPC.

Mimicking lip features in free-flap reconstruction of lip defects

This paper introduces a technique of lip reconstruction using free flaps in which recognisable landmarks are mimicked by strategic placement of flap junctions. The technique was applied in 15 patients undergoing reconstruction of combined cheek and lip defects using single (n= 9) or double (n= 6) free flaps. Attention to flap design and strategic placement of flap junctions successfully created the vermilion-cutaneous junction, oral commissure and labiomental groove. The presence of these distinguishing features improved the appearance of the reconstructed lip.

Dietary exposure to nitrite and nitrosamines and risk of nasopharyngeal carcinoma in Taiwan

Previous studies of nasopharyngeal carcinoma (NPC) have found elevated risks with higher consumption of salted fish and preserved foods, particularly during childhood. These foods can contain high levels of nitrosamines; however, most studies have not estimated exposure to nitrosamines directly. We conducted a case-control study in Taiwan to evaluate dietary intakes and NPC risk. A total of 375 cases (99% response rate) and 327 controls (88% response rate) were interviewed about their diet as an adult and at age 10 using a food-frequency questionnaire. We interviewed mothers of participants about their child's diet at age 10, age 3 and during weaning and the mother's diet while she was breast-feeding. Mothers of 96 cases and 120 controls were interviewed. Nitrosamine and nitrite levels were assigned to 66 foods based on published values. Intake of nitrosamines and nitrite as an adult was not associated with risk of NPC. High intakes of nitrosamines and nitrite during childhood and weaning were associated with increased risks of NPC for foods other than soy products. Adjusted odds ratios for the highest quartile were 2.2 [95% confidence interval (CI) 0.8-5.6] for age 10, 2.6 (95% CI 1.0-7.0) for age 3 and 3.9 (95% CI 1.4-10.4) for weaning diet. Intakes of nitrite and nitrosamines from soybean products during childhood and weaning were inversely associated with risk. Soybeans contain known inhibitors of nitrosation, and thus may explain the inverse association we observed. Our results suggest that nitrosamine and nitrite intake during childhood may play a role in the development of NPC.

The expression of DAZL1 in the ovary of the human female fetus

OBJECTIVE

To determine whether DAZL1 is expressed in human fetal ovarian tissue.

DESIGN

The presence of DAZL1 expression was determined by reverse transcriptase polymerase chain reaction (RT-PCR).

SETTING

Academic tertiary care medical center and research unit of university.

PATIENT(S)

Five female abortuses between the 19th and 22nd week of gestational age.

INTERVENTION(S)

Fetal ovarian tissues were collected immediately after the cessation of the heart beat.

MAIN OUTCOME MEASURE(S)

The product of RT-PCR.

RESULT(S)

DAZL1 expression was detected in all five samples.

CONCLUSION(S)

DAZL1 is not only expressed in human testes but also in ovaries. It may play a role in germ cell survival and gonad development in both sexes.

Locally recurrent nasopharyngeal carcinoma

PURPOSE

To assess the outcome of and determine prognostic factors for locally recurrent nasopharyngeal carcinoma (NPC) in patients treated with a second course of radiotherapy (RT).

MATERIALS AND METHODS

From 1982 to 1995, 186 NPC patients, who had initially been treated in the Department of Radiation Oncology, Chang Gung Memorial Hospital-Linkou, developed local recurrence in the nasopharynx and were re-treated with RT (>/=20 Gy). The time from the initial RT to re-treatment ranged from 8 to 136 months (median: 23 months). All patients were treated with external RT and conformal radiotherapy was used in 35 patients after 1993. Fifteen received radiosurgery as a boost treatment. The RT dose at the nasopharyngeal tumor area ranged from 20 to 67.2 Gy (median 50 Gy). Eighty-two patients received one to eight courses of cisplatin-based chemotherapy in addition to RT.

RESULTS

The 1-, 3- and 5-year survival was 54.9, 22. 1 and 12.4%, respectively. Patients whose tumor relapsed later than 2 years after the first treatment had a better survival than those with earlier relapse (3-year survival: 30.1 vs. 10.8%; P=0.015), but the difference became insignificant in patients who received >/=50 Gy. Patients without evidence of intracranial invasion or cranial nerve palsy had better survival than those with such lesions (3-year survival: 30.9 vs. 3.7%; P=0.006). A re-treatment dose >/=50 Gy yielded better survival (3-year survival: 22.8 vs. 18.5%; P=0.003). Addition use of radiosurgery may improve survival. The use of chemotherapy did not improve survival. Conformal radiotherapy resulted in significantly fewer severe complications than conventional RT.

CONCLUSIONS

A repeat course of RT for locally recurrent NPC successfully prolongs survival in a significant number of patients. Intracranial invasion and/or cranial nerve palsy and re-treatment dose affect the prognosis, with a dose of >/=50 Gy significantly improving survival. Radiosurgery boost may also improve survival. Our preliminary data indicates that conformal radiotherapy may decrease the severity of radiation-induced complications. However; longer follow-up and larger sample size is necessary to document the findings.

Impact of oral submucous fibrosis on chemotherapy-induced mucositis for head and neck cancer in a geographic area in which betel quid chewing is prevalent

In Southeast Asia and Taiwan, betel quid chewing is prevalent. Patients with head and neck cancer who chewed betel quid habitually seem to experience more severe chemotherapy-induced mucositis in our clinical practice. To validate this issue, patients with untreated head and neck cancer who received cisplatin (cDDP) plus a 5-fluorouracil (5-FU)-based neoadjuvant chemotherapy were included in this analysis. Information on the consumption of betel quid, tobacco, and alcohol were recorded before chemotherapy. Oral submucous fibrosis (OSF) was diagnosed clinically according to the fibrotic appearance of the mucosa and trismus. Mucositis was scored according to the World Health Organization criteria, and the mucositis score of the first course of chemotherapy was used for analysis. From December 1993 to April 1996, 120 patients were enrolled in this trial. Neither the betel quid chewing nor the cancer of the oral cavity was to be a significant factor for mucositis. However, clinically diagnosed OSF was found to display a significant correlation with more severe mucositis (p = 0.02). We concluded that in betel quid chewing-prevalent areas, OSF was a risk factor of more severe mucositis in head and neck cancer patients treated by CDDP and 5-FU-based regimens.

Oromandibular reconstruction using a third free flap in sequence in recurrent carcinoma

Successful results of a second microsurgical reconstructive attempt have been reported previously in recurrent oral carcinoma. However, the feasibility of a third free flap following a third excision has remained to be determined. Six oral carcinoma patients with multiple recurrences, surgical excisions and free flap reconstructions on three separate occasions are presented. Resections had a curative intent in all cases in the first and second ablations and in four of the six cases in the third one. Five radial forearm flaps and one double free flap were used for the first reconstruction. During the second reconstruction two radial forearm, two fibula osteoseptocutaneous, one double free flap and one rectus femoris flap were used to reconstruct the larger defects resulting from excision of the recurrent tumours. However, no vascularised bone transfers were performed following the third excision and soft tissue free flap plus plate option was used for segmental mandibular defects. There was one partial flap loss among 21 free flaps performed. Three patients died within an average of 8 months following the third reconstruction while the others remained alive, surviving an average of 6 months. In conclusion, a third free tissue transfer for reconstruction in multiply recurrent oral carcinoma was found to be feasible, safe and effective. The use of free flaps contributed to the prevention of complications in these difficult cases and enabled the patients to spend the remaining days of their lives outside hospital.

Cigarette smoking, alcohol consumption and risk of nasopharyngeal carcinoma in Taiwan

OBJECTIVES

Nasopharyngeal carcinoma (NPC) is rare in most countries but occurs with relatively high frequency among southern Chinese populations throughout the world. A case-control study of NPC was conducted in Taiwan to investigate the importance of active and passive cigarette exposure and alcohol consumption as risk factors for this disease.

METHODS

375 histologically confirmed incident NPC cases (99% response rate) were prospectively identified from two hospitals in Taipei between July 1991 and December 1994 and administered a detailed questionnaire. 327 healthy community controls individually matched to cases on sex, age and residence were selected (88% response rate).

RESULTS

After multivariate adjustment, the odds ratio (OR) and 95% confidence interval (CI) was 1.7 (1.1-2.9 with p = 0.03 for increasing dose-response) for those who smoked for > or = 25 years compared with non-smokers. Passive smoking during childhood or adult life was not associated with an increased risk of disease. Alcohol consumption was not associated with NPC risk. The OR for subjects with > or = 15 grams of ethanol per day compared to non-drinkers was 1.1 (95% CI = 0.7-1.7).

CONCLUSIONS

Our results suggest that long term cigarette smoking is associated with NPC but that low level exposure to cigarette smoke via passive exposure and alcohol consumption are not associated with disease risk.

Anesthesia for ankylosing spondylitis patients undergoing transpedicle vertebrectomy

BACKGROUND

Ankylosing Spondylitis (AS) patients present specific challenges to the anesthesiologists. Airway management, central venous access, positioning, neuraxial monitoring and protection as well as management of massive blood loss may prove to be difficult. We retrospectively reviewed the anesthetic management of consecutive AS patients who underwent transpedicle vertebrectomy (TPV).

METHODS

To secure airway and administer anesthesia, we used awake fiberoptic endotracheal intubation. The central venous access was attempted through the infraclavicular approach. The positioning was made possible with modification of the operation table and padding. The neuraxial monitoring was done with both somatosensory evoked potentials (SSEPs) and the modified transcranial magnetic evoked potential (tcMMEP). The spinal cord protection was attempted with deliberate hypothermia. To prevent massive blood loss we did controlled hypotension, and autotransfusion.

RESULTS

Fiberoptic endotracheal intubation was done smoothly in all cases except two. In one of these two cases, endotracheal intubation was successful only after cricothyroidectomy and retrograde intubation. In the other case antegrade stiff catheter guided intubation was attempted to overcome the acute angulation cause by fixed cervical flexion. Central venous access through infraclavicular approach was agreeable except one case of pneumothorax. Massive rapid blood loss during vertebral osteotomy, occurred in one patient with fall of the mean blood pressure to 20 mmHg and ventricular tachycardia for 10 min, during which all the SSEPs and tcMMEP activities disappeared. The patient recovered without sequelae.

CONCLUSIONS

Although it is extremely challenging, with proper planning, anticipation of difficulties and meticulous work in airway management, central venous catheterization and positioning as well as prevention of neurological injury and massive bleeding, we successfully accomplished fine job of anesthesia for the AS patients presented for correction of severe kyphosis.

Management of secondary soft-tissue deficits following microsurgical head and neck reconstruction by means of another free flap

Secondary soft-tissue deficits may develop following a microsurgical reconstruction in the head and neck region because of inadequate planning or chronic effects of radiotherapy. Although most cases could be managed with alternative methods, free flaps might be necessary in difficult cases. Herein are described 11 cases of microsurgical head and neck reconstruction in which secondary soft-tissue deficits required transfer of another soft-tissue free flap. All patients had malignant tumors treated with surgical resection, and their defects were reconstructed with free flaps. Seven patients received either preoperative or postoperative adjunctive radiotherapy. These patients gradually developed signs and symptoms of soft-tissue deficiency in the reconstructed area, and a soft-tissue free flap transfer was required for treatment within an average of 21.5 months of their initial reconstruction. Five rectus abdominis, one rectus femoris, one latissimus dorsi, one tensor fasciae latae myocutaneous, one radial forearm, one medial arm, and one dorsalis pedis flap were used for this purpose. All flaps survived completely. The average follow-up time was 32 months. Significant improvement was achieved in all cases, and no further major surgical procedures were required. Secondary soft-tissue deficits that could not be predicted or prevented during the initial microsurgical reconstruction may be treated successfully by a subsequent free soft-tissue transfer in selected cases.

Free fibula osteoseptocutaneous-pedicled pectoralis major myocutaneous flap combination in reconstruction of extensive composite mandibular defects

Lateral composite mandibular defects resulting from excision of advanced oral carcinoma often require mandible, intra-oral lining, external face, and soft-tissue bulk reconstruction. Ignorance of importance soft-tissue deficit in those patients may cause significant morbidity and functional loss. Such defects, therefore, can be reconstructed best with a double free flap technique. However, this procedure may not be feasible for every patient or surgeon. An alternative procedure is a free fibula osteoseptocutaneous flap combined with a pedicled pectoralis major myocutaneous flap. This combination was used in reconstruction of extensive composite mandibular defects in 14 patients with T3/T4 oral squamous cell carcinoma. All patients were men, and the average age was 54.3 years. The septocutaneous paddle of the fibula flap was used for the mucosal lining of the defects while the bony part established the rigid mandibular continuity. The pectoralis major flap then covered the external skin defect in the face and cheek, and the dead spaces left by the extirpated masticator muscles, buccal fat, and parotid gland. One free fibula flap failed totally, and one pectoralis major flap developed marginal necrosis. At the time of final evaluation, nine patients (64.3 percent) were alive, surviving an average of 25.7 months. All patients eventually regained their oral continence and an acceptable cosmetic appearance. In conclusion, the fibula osteoseptocutaneous flap plus regional myocutaneous flap choice is a successful and technically less demanding alternative to the double free flap procedures in reconstruction of extensive lateral mandibular defects.

Microsurgical reconstruction in recurrent oral cancer: use of a second free flap in the same patient

Primary microsurgical reconstruction is the treatment of choice for ablative defects of oral carcinoma. As a result of this trend, more and more patients with recurrent oral carcinoma who have been initially treated with surgical excision and reconstructed with free flaps are being seen. However, a second microsurgical reconstruction attempt in these cases raises questions about the flap choices, availability of recipient vessels, and effects of previous treatment modalities. Herein, 35 patients with perioral carcinoma who had two successive tumor resections and reconstruction with free flaps on each occasion are presented. A total of 75 free tissue transfers were carried out for the first and second reconstructions. After the first tumor resection, 28 radial forearm fasciocutaneous flaps, 7 fibula osteoseptocutaneous flaps, 1 iliac osteomyocutaneous flap, and 2 rectus abdominis myocutaneous flaps were used. For reconstruction after the recurrence, 17 radial forearm fasciocutaneous flaps, 13 fibula osteoseptocutaneous flaps, 3 rectus abdominis myocutaneous flaps, 2 anterolateral thigh flaps, 1 jejunum flap, and 1 tensor fasciae latae flap were used. More vascularized bone transfers were performed during the second reconstruction since the excision for the recurrence frequently required segmental mandibulectomy. The complete flap survival rate was 97.3 percent and 94.6 percent with a reexploration rate of 7.9 percent and 13.5 percent for the first and second free tissue transfers, respectively. The mean follow-up time throughout the procedures was 37.5 months. Disease-free interval between reconstructions was 20.8 months. At the time of evaluation, 54.3 percent of the patients were surviving an average of 19 months since the second reconstruction. The results suggest that free flaps represent an important option in reconstruction of recurrent perioral carcinoma cases undergoing reexcision. When used in this indication they are as safe and effective as the initial procedure.

Sensation recovery on innervated radial forearm flap for hemiglossectomy reconstruction by using different recipient nerves

The objectives of this study were (1) to determine the extent of sensory recovery on hemitongues reconstructed with innervated radial forearm flaps and (2) to assess the influence of various clinical and surgical factors over the return of sensation, including the use of different recipient nerves for neurorrhaphy. Twenty-eight patients with tongue cancer who underwent hemiglossectomy and primary reconstruction with innervated radial forearm flaps over a 3-year period were studied. Mean postoperative follow-up was 18.2 months (range 6 to 32 months). Sensory recovery was assessed in a blind manner by two examiners that used (1) static two-point discrimination, (2) light touch sensation, (3) pain perception, and (4) hot and cold temperature perception. Different surfaces were assessed with each method on the reconstructed hemitongue and on the intact contralateral hemitongue (used as control). The following factors and their relationship with flap sensory recovery were analyzed: age, smoking history, size of the reconstructed defect, administration of postoperative radiation therapy, recipient nerve, and neurorrhaphy technique. Comparative statistical analysis (p < 0.05) between both hemitongues was performed using paired t test followed by Bonferroni correction for static two-point discrimination and light touch sensation. Fisher exact test analysis was used for pinprick and hot and cold temperature perception. The control side was ignored in analyzing the effects of the risk factors. The tip, dorsal aspect, ventral surface, and floor of mouth on the reconstructed hemitongue had comparable static two-point discrimination when compared with the intact hemitongue. Light touch sensation was also similar in the tip and dorsal aspect of both hemitongues; however, a statistically significant difference (p < 0.05) was observed on the ventral surface and floor of mouth of the reconstructed hemitongues. Likewise, pain perception was significantly decreased in the floor of the mouth, compared with other surfaces. No clearly dependent association was established between return of flap sensation and age, tobacco use, and size of the reconstructed defect. Light touch sensation, pain, and temperature perception were significantly decreased when the patients had received postoperative radiation therapy. In addition, all four sensory tests were significantly diminished (p < 0.05) when the recipient nerve used for neurorrhaphy was a nerve other than the lingual or the inferior alveolar nerve, and also when an end-to-side nerve repair was used. Sensation recovery of the innervated radial forearm flap after hemitongue reconstruction approaches normal compared with the contralateral intact hemitongue. Lower return of sensation may be anticipated in patients who receive postoperative radiotherapy. Good recovery of sensation is predictable when either the lingual or inferior alveolar nerve is used for neurorrhaphy, in contrast to using other recipient nerves.

Familial and sporadic cases of nasopharyngeal carcinoma in Taiwan

BACKGROUND

Nasopharyngeal carcinoma (NPC) has a striking geographic/ethnic distribution, with especially high rates among southern Chinese. Previous studies have indicated that a family history of NPC is associated with increased risk and noted familial clustering in low-risk populations.

MATERIALS AND METHODS

We investigated differences between sporadic and familial cases of NPC in a case-control study of 375 histologically confirmed NPC cases (99% response rate) and 328 age-, sex-, and geographically-matched controls (88% response rate). All participants answered a detailed risk factor interview and donated blood for EBV and CYP 2E1 testing.

RESULTS

Subjects with a first degree relative with NPC had on odds ratio (OR) of 7.6 (95% confidence interval (CI) = 2.3-25), while those with a family history of any other cancer had only a slightly elevated risk of disease (OR = 1.4; 95% CI = .93-2.2). Of the cases, 25 (6.7%) were familial--having at least one first degree relative with NPC. No significant difference was seen between familial and sporadic cases with respect to sex, age, ethnicity, histology or stage. There was a nonsignificant (p = 0.16) increase in T1N2 tumors among familial cases, suggesting a more aggressive tumor. Family history of other cancers, EBV serologies, or the distribution of the RsaI c2 form of the allele of cytochrome P450 2E1 were also not significantly different between the two groups.

CONCLUSIONS

In conclusion, while genetic factors are likely to play an important role in NPC pathogenesis, our results provide little evidence that a familial form of NPC exists with characteristics notably distinct from sporadic cases.

Routine donor leg angiography before vascularized free fibula transplantation is not necessary: a prospective study in 120 clinical cases

To evaluate the value of routine preoperative angiographies of donor sites, 120 patients with free fibula osteoseptocutaneous flap transplantations were included in this prospective study, which consisted of preoperative evaluation of dorsalis pedis and tibial posterior artery pulsation and angiographies of the donor legs (120 patients) and contralateral legs (111 patients). Both pedal pulses were palpable in 114 patients, and only one pulse was palpable in six patients. The respective nonpalpable foot pulses were detectable with pencil Doppler in five patients, but they were not detectable in one patient. Intraoperatively, the latter patient had a relatively hypertrophied peroneal artery as compared with both the tibial posterior and tibial anterior arteries. The angiographic result was arteria peronea magna. The other five patients showed intraoperatively and angiographically normal-sized major arteries of the lower leg. In three patients with normal pedal pulses, hypoplasias of either the tibial anterior or tibial posterior arteries were found intraoperatively. These findings corresponded with the angiographical results. In all patients (n = 119), except one with peroneal artery hemangioma, free osteoseptocutaneous fibula flap was harvested from the originally planned leg without subsequent sequelae to the respective donor leg. In 231 leg angiographies, only 7 cases (3 percent) with abnormalsized major lower leg arteries were described. The diagnoses in these cases were hypoplasia of either the tibial posterior or tibial anterior artery (4 cases), arteria peronea magna (2 cases, one of which was a false positive), absence of peroneal artery combined with hypoplastic tibial posterior artery (1 case), and hemangioma of the peroneal artery (1 case). From this prospective study, it was determined that routine preoperative angiography of the donor leg before fibula transplantation is not justified. It does not add relevant new information about donor leg vascularity, provided that the clinical evaluation of the pedal pulses is well conducted. The only two conditions that may require a preoperative donor leg angiography are abnormal pedal pulses or significant previous lower leg trauma.

Donor site morbidity after suprafascial elevation of the radial forearm flap: a prospective study in 95 consecutive cases

From March of 1995 to November of 1997, 95 free radial forearm flaps for orofacial reconstructions were performed and included in this prospective study of donor site morbidity. All flaps were elevated using the suprafascial dissection technique. Donor site closure was performed with either split-thickness skin grafts (64 cases) or full-thickness skin grafts (31 cases). Among the 95 flaps, there were two complete flap losses and one partial flap loss because of arterial thrombosis. One orocutaneus fistula was successfully treated with a pedicled pectoralis major flap. At the donor site, the rate of complete take of skin graft was 94 percent in 95 patients. Functional and aesthetic results evaluated at least 6 months postoperatively in 50 patients revealed no significant change in grip power, pulp-to-pulp pinch power, or wrist movement in the complete skin graft take group (45 cases), whereas in the partial skin graft failure group (5 cases), both grip power and movement were significantly decreased. There was no remarkable cold intolerance in any of the 50 patients. Critical evaluations of sensory change revealed numbness distal to the donor site in 54 percent of the patients. However, dysesthesia was usually mild and improved spontaneously as time passed. Aesthetic outcome was rated as good or fair in 98 percent of the cases. The results of this prospective study show that suprafascial elevation of the radial forearm flap is superior to the classic elevation technique, particularly with regard to a higher rate of immediate complete take of skin grafts, thus avoiding impairment of range of motion and strength of the donor hand.

Double free flaps in reconstruction of extensive composite mandibular defects in head and neck cancer

Extensive composite defects of the lower jaw are defined as those that involve skin, mandible, oral mucosa, and soft tissues. The enormous size and multilayered nature of these defects challenge most of the current reconstructive techniques. For reconstruction of extensive composite mandibular defects in 36 advanced oral cancer patients, two free flaps were used simultaneously in a complementary fashion. The aim was to provide bone reconstruction and adequate soft-tissue coverage in an optimal form. Primary reconstruction was carried out in 34 of 36 cases. The fibula osteoseptocutaneous-radial forearm fasciocutaneous flap combination was most commonly used (n = 20), followed by the fibula osteoseptocutaneous-rectus abdominis myocutaneous flap (n = 11). The other combinations included the fibula osteoseptocutaneous-tensor fasciae latae, the fibula osteoseptocutaneous-rectus femoris, the iliac crest-radial forearm, and the iliac crest-tensor fasciae latae flaps. In 11 cases, the second free flaps were attached to the distal runoff of the first free flaps because of unavailability of recipient vessels. The mean operation time was 12 hours 10 minutes. The complete flap survival rate was 93 percent (67 of 72 flaps) with 2.8 percent total (2 of 72) and 4.2 percent partial (3 of 72) flap failures. Median follow-up time was 14 months, and 44 percent of the patients were alive at the time of evaluation, surviving an average of 36 months. The average survival time for those who died was 11.1 months. The authors believe that in selected cases the double free-flap procedure for one-stage reconstruction of massive mandibular defects is justified because it is safe and effective and improves the quality of life and the number of days spent outside of the hospital for these patients.

Modified transcranial electromagnetic motor evoked potential obtained with train-of-four monitor for scoliosis surgery

BACKGROUND

To monitor the spinal cord with somatosensory evoked potential (SSEP) is an accepted adjunct in the surgical correction of spinal deformities, but it does not directly assess the motor function. The use of motor evoked potential (MEP) has thus been introduced in an effort to meet this important need.

METHODS

This preliminary report concerned 30 cases of scoliosis who underwent surgical correction under the surveillance of modified transcranial electromagnetic motor evoked potential (tcMMEP). Train-of four (TOF) stimulator output was connected to an electromagnetic stimulator. The rate of repetition and interval of stimulation were controlled by TOF stimulator. Electromyographic (EMG) signals were obtained from the abductor hallucis muscle of both feet and interpreted as MEP activity. Anesthesia was made possible by propofol as a basic agent and isoflurane as supplement. Analgesia was obtained with sufentanil and fentanyl and amnesia enhanced by midazolam. Atracurium mixed with vecuronium in a ratio of 4:1 by weight in possible lowest dose was given to provide adequate muscle relaxation yet without the molestation of rapid reversal upon the request of wake-up test by the surgeon. Deliberate hypothermia and controlled hypotension were also applied since they did not interfere with the tcMMEP signals.

RESULTS

Although no attempt was made to control the level of muscle relaxation at T1 more than 30%, tcMMEP signals could be obtainable during induction, at the time of surgical correction and at the end of the operation. TcMMEP onset latency was 27.32 +/- 0.45 msec on the left side and 27.27 +/- 0.54 msec on the right side. The amplitude was 3.52 +/- 1.97 mV on the left side and 4.05 +/- 1.22 mV on the right side.

CONCLUSIONS

The modified tcMMEP is so stable and convincing that research for similar modification is now undergoing with the other brand of TOF monitor by our team.

Reliability of the venae comitantes in venous drainage of the free radial forearm flaps

The radial venae comitantes are usually considered as an accessory venous outflow tract in the free radial forearm flap because of their smaller size and thinner structure when compared with those of the cephalic vein. To evaluate the reliability of the deep venous system, a single radial vena comitans anastomosis was performed to serve as the sole venous outflow tract in 94 consecutive radial forearm free flap transfers. The suprafascial dissection technique was used in flap elevation, which allowed preservation of the cephalic vein and the dorsal branch of the radial nerve. In all cases, the external diameter of at least one vena comitans was adequate (< or = 1.5 mm) to perform a smooth microvascular anastomosis; in none of the cases was a venous anastomosis failure detected. Preselected use of a single vena comitans for the venous drainage of radial forearm free flaps was proven to be reliable and was preferred because of the ease of flap dissection and better donor site appearance.

Increased C-type natriuretic peptide mRNA expression in the kidney of diabetic rats

To investigate the responsiveness of renal-synthesized C-type natriuretic peptide (CNP) to changes in water and electrolyte balance, we measured renal CNP mRNA levels, plasma CNP concentrations and urinary CNP excretion rates in streptozotocin-induced diabetic rats eating a normal (0.26% NaCl) or low (0.04% NaCl) salt diet. Using reverse transcription-PCR followed by Southern blot analysis, we found that renal cortical and medullary CNP mRNA levels were markedly enhanced in diabetic rats from the 14th day and remained enhanced with an accompanying elevation of urinary CNP excretion rates for the entire 60-day study period. All increases of renal CNP mRNA and urinary CNP excretion rates in diabetic rats were attenuated in low salt diet-treated diabetic rats as well as insulin-treated diabetic rats. These results demonstrate that renal CNP synthesis is enhanced in diabetic rats and the increase of renal CNP mRNA is ameliorated by salt restriction and insulin treatment. These results imply that renal-synthesized CNP is responsive to the alteration of water and electrolyte homeostasis in diabetic rats.

CYP2E1 genetic polymorphisms and risk of nasopharyngeal carcinoma in Taiwan

BACKGROUND

Nasopharyngeal carcinoma occurs disproportionately among individuals of Chinese descent. The cytochrome P450 2E1 enzyme (CYP2E1) is known to activate nitrosamines and other carcinogens that are possibly involved in the development of this disease. Certain alleles of the CYP2E1 gene are thought to be more highly expressed than others, and their distribution varies between Asian and Caucasian populations. We conducted a case-control study to investigate whether such variations affect the risk of developing nasopharyngeal cancer.

METHODS

Three hundred sixty-four patients with nasopharyngeal carcinoma (96% of 378 eligible patients) and 320 control subjects (86% of 374 eligible subjects) were studied. A risk factor questionnaire was administered to participants to assess factors postulated to be linked to nasopharyngeal carcinoma. Peripheral blood was obtained from all subjects and DNA was purified from nucleated cells. A polymerase chain reaction-based restriction fragment length polymorphism assay that used the restriction enzymes Rsa I and Dra I was used to detect wild-type and variant forms of the CYP2E1 gene.

RESULTS

Individuals homozygous for an allele of the CYP2E1 gene that is detected by Rsa I digestion (c2 allele) were found to have an increased risk of nasopharyngeal carcinoma (relative risk [RR] = 2.6; 95% confidence interval [CI] = 1.2-5.7); this effect was limited to nonsmokers (RR = 9.3; 95% CI = 2.7-32) and was not affected by alcohol consumption.

CONCLUSIONS

Our findings suggest that the CYP2E1 genotype is a determinant of nasopharyngeal carcinoma risk.

Primary cervical neuroblastoma in infants

Although neuroblastoma is a relatively common malignancy of childhood, it is rarely of cervical origin. We encountered two cases of primary cervical neuroblastoma in infants. The first case was in a newborn who presented with noisy breathing, dyspnea, and choking on feeding soon after birth. Physical examination disclosed a left retropharyngeal mass near the midline causing aerodigestive compromise. Magnetic resonance imaging showed a well-defined hyperintense mass in the corresponding region. The infant underwent complete surgical excision of the mass 1 month after birth. The pathology report confirmed neuroblastoma. Horner's syndrome developed soon after surgery but resolved spontaneously within 6 months. No recurrence was noted during a 3-year follow-up period. The second patient, a 5-month-old female, presented with stridor and shortness of breath of 2-weeks' duration due to a right cervical mass. Magnetic resonance imaging showed a parapharyngeal mass suggestive of neuroblastoma. Complete surgical excision was done at the expense of sacrificing the sympathetic nerve trunk. The pathologic diagnosis was moderately differentiated neuroblastoma. No recurrence was noted when the patient was seen 2 years after surgery, although right-sided Horner's syndrome persisted. Surgical intervention can result in a good prognosis for low stage cervical neuroblastomas; however, long-term follow-up is important.

Atlantoaxial arthrodesis using Halifax interlaminar clamps reinforced by halo vest immobilization: a long-term follow-up experience

Thirty-two patients who underwent atlantoaxial arthrodesis using Halifax interlaminar clamps and halo vests between January 1989 and December 1992 were reviewed. The atlantoaxial instabilities were related to trauma in 16 patients, including 14 patients with unstable odontoid fractures, 1 patient with a complex C2 fracture, and 1 patient with a disrupted transverse ligament. Of the other 16 patients, whose atlantoaxial instabilities were nontraumatic in origin, 9 had instabilities that were secondary to rheumatoid arthritis, 1 had instability that was secondary to tuberculous infection, and 6 had instabilities that were caused by os odontoideum. The patients were followed postoperatively with lateral cervical radiographs for an average of 37 months (range, 16-59 mo). Solid atlantoaxial arthrodeses were achieved in all (100%) of these 32 patients after 32 to 111 days (average, 84.5 d) of halo immobilization, indicating atlantoaxial arthrodeses can be reasonably anticipated when Halifax interlaminar clamps with autogenous iliac bone grafting are reinforced by halo vest immobilization for 3 months.

[Pulmonary and paradoxical embolism after total knee replacement--a case report]

Pneumatic tourniquet and hone cement are often applied in orthopaedic surgery. In lower limb surgery, deep vein thrombosis may occur after release of tourniquet, causing embolism of lungs and vital organs. Paradoxical embolism may develop if the patients present extracardiac or intracardiac right to left shunt, such as atrial septum defect, etc. A 60-year-old female patient suffered from osteoarthritis of both knees was admitted for total knee replacement (TKR). Pneumatic tourniquet was inflated on the operated leg for the orthopaedic surgery which lasted for 2h. Dyspnea, sinus tachycardia and abdominal pain were noted after TKR. Blood gases analysis showed arterial hypoxemia and respiratory alkalosis. Chest X-ray revealed diffused bilateral pulmonary infiltration, pulmonary trunk engorgement, and decreased lung markings. Two days after TKR under the impression of peritonitis, she received exploratory laparotomy in which ischemic bowel and gall bladder were found. Pulmonary and paradoxical embolism were diagnosed, both of which were the well-known complications of TKR with tourniquet and bone cement application. The patient finally succumbed because of multiple organ failures.

Biomechanical evaluation of subcortical versus bicortical screw purchase in anterior cervical plating

The purpose of this in vitro study is to compare the stabilities provided by anterior cervical H-plating with screws purchased either subcortically or bicortically on porcine cervical spines. Nine porcine cervical spines (C3-C4) were challenged by 12 Nm in extension followed by 6 Nm in flexion in 6 consecutive steps, i.e., (1) when disc was intact, (2) after discectomy. Subsequently, a tricortical bone graft was inserted to simulate interbody fusion. Each specimen was tested again (3) when plated with 16 mm screws to purchase subcortically and (4) after cyclic loading (f = 0.5 Hz, n = 1000), (5) when plated with 30 mm screws to purchase bicortically and (6) after cyclic loading. Neutral zone and range of motion were parameters normalized for comparison. The results showed comparable stability in constructs plated with screws purchased either subcortically or bicortically before cyclic loading. Cyclic loading deteriorated construct-bone relation in both groups, yet bicortically purchased screws rendered additional stability in anterior cervical plating.

Cytochrome P4502E1 genetic polymorphisms and risk of nasopharyngeal carcinoma: results from a case-control study conducted in Taiwan

CYP2E1 is responsible for the metabolic activation of nitrosamines believed to be involved in the pathogenesis of various tumors. Nasopharyngeal carcinoma (NPC) is a tumor thought to be linked to nitrosamine exposure. To investigate the possible role of CYP2E1 genetic polymorphisms in the etiology of this tumor, we investigated 50 histologically confirmed NPC cases from Taiwan and 50 controls matched to cases on age, sex, and residence. Samples were examined for RFLPs in the CYP2E1 gene by PCR amplification followed by digestion with DraI and RsaI. Among healthy controls, the allelic frequency of wild-type and variant forms of CYP2E1 were 79 and 21%, respectively, using DraI enzyme digestion and 82 and 18%, respectively, using RsaI enzyme digestion. As compared with individuals who were homozygous for the wild-type CYP2E1 gene, those found to be homozygous for the variant form of the gene by DraI digestion were at a 5-fold excess risk of disease (95% confidence interval = 0.95-16). Similarly, subjects homozygous for the variant form of the CYP2E1 gene by RsaI digestion were at 7.7-fold excess risk of developing NPC (95% confidence interval = 0.87-68). Individuals found to be heterozygous for the gene were at similar risk of disease compared to those homozygous for the wild-type gene. A strong association was observed between the RFLPs detected by DraI and RsaI digestion of CYP2E1; a correlation coefficient of 0.86 for controls and 0.91 for cases was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Variance in the measurement of sagittal lumbar spine range of motion among examiners, subjects, and instruments

STUDY DESIGN

Repeated measurements were made of lumbar sagittal range of motion by 14 examiners using three different measurement instruments.

OBJECTIVES

To determine the reliability of lumbar range of motion measurements among examiners, subjects, and instruments, and to determine whether variance is due to subject inconsistency, examiner inconsistency, differences between examiners, or differences between instruments.

SUMMARY OF BACKGROUND DATA

Measurements of lumbar spine range of motion are widely used in research and clinical applications as well as in disability rating systems for patients with low back pain.

METHODS

Fourteen examiners measured the sagittal range of motion. Using three instruments, 18 healthy subjects were measured twice in a randomized sequence with blinded readings when performing full flexion, and partial flexion to a defined midpoint. None of the examiners routinely used the particular instruments in their practices.

RESULTS

The mean test-retest reliability was 4.9 degrees. The intraexaminer reliability did not differ significantly among the examiners. Furthermore, there was no systematic difference resulting from instruments or posture condition. However, there was a statistically significant variance among examiners--i.e., a poor interexaminer reliability.

CONCLUSION

The most likely explanation for these findings is the variability among examiners in locating bony landmarks. The results indicate that range of motion measurements must be interpreted with caution in clinical, research, and disability applications. Test administrator training may improve results, but this could not be determined from this study.

Overlapping initiator and TATA box functions in the basal core promoter of hepatitis B virus

The regulation of transcription of the hepatitis B virus core promoter is an important event in the viral life cycle. Two messages, precore and pregenomic RNAs, that are initiated 30 nucleotides apart are produced by the core promoter. Precore RNA encodes nucleocapsid protein and pregenomic RNA core and polymerase. The latter transcript also serves as a template for viral genome replication via reverse transcription. We have previously defined a basal core promoter, which contains four TA-rich sequences (TA1 through TA4) but no canonical TATA element, that can direct transcription of both messages. In this study, we demonstrated that a stretch of 15 nucleotides containing TA4 is sufficient to direct precise initiation of both precore and pregenomic transcripts. This sequence can function as both an initiator and a TATA element. Mutational analysis further revealed that sequences essential for either function are colocalized. The significance of this finding with respect to the basal transcription mechanism and regulation of viral gene expression is discussed.

The effects of lateral trunk bending on muscle recruitments when resisting nonsagittally symmetric bending moments

STUDY DESIGN

Surface electromyographic activities were measured in 15 subjects as they maintained a static laterally bent trunk posture and resisted sagittally symmetric and asymmetric moments applied to their torsos. The moment magnitudes were 20 and 40 Nm and had transverse plane directional components in 30 degrees increments surrounding the subjects' torsos.

OBJECTIVES

To quantify the myoelectric responses from eight trunk muscles as asymmetric loads were applied to the laterally bent torso.

SUMMARY OF BACKGROUND DATA

Asymmetric material handling frequently results in lateral bending of the torso. Each of these factors have been linked via epidemiologic investigations to the incidence of low back disorders. Little information is available that describes the response of the trunk muscles when the trunk is bent to the side.

METHODS

Subjects stood in a reference frame and adjusted their trunk posture to marks on a video display that indicated when a 20 degrees lateral bend to the right had been achieved. Moments were applied to the torso by connecting weights via cables and pulleys to a chest harness. Electromyographic activities were recorded bilaterally from the erector spinae, latissimus dorsi rectus abdominis, and external oblique muscles.

RESULTS

The electromyographic data indicated that the muscles showed the greatest activity when they were in opposition to the applied sagittal and frontal plane moments. The left external oblique showed the greatest response and was sensitive to the widest range of moment direction conditions. All of the muscles, except for the left latissimus dorsi, at times contributed antagonistic moments in the sagittal plane or the frontal plane, or in both planes. These data were compared with previously obtained data from an upright neutral posture.

CONCLUSIONS

Statistical analyses indicated that the responses of both external obliques and the left erector spinae to the moment direction conditions were significantly different between the laterally bent and neutral postures.

Double intraspinal enterogenous cysts

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Effectiveness of shunting in patients with normal pressure hydrocephalus predicted by temporary, controlled-resistance, continuous lumbar drainage: a pilot study

From 1984 to 1992 15 consecutive cases of normal pressure hydrocephalus were included in this pilot study. A series of tests included CT of the brain, grading of the cognitive mental state with the mini-mental state examination; urodynamic studies, and gait evaluation. These tests were carried out on admission, and repeated on day 1, day 3, and day 5 after controlled-resistance, continuous lumbar drainage (CRCLD). During this period, eight patients showed significant improvements of cognitive mental state, urodynamic studies, or gait and were regarded as CRCLD responders; the remaining seven patients were regarded as CRCLD non-responders. The CRCLD was routinely removed on day 6 after the drainage procedure and a ventriculoperitoneal (VP) or a lumboperitoneal (LP) shunt was randomly selected for each patient. The tests were repeated one week after shunting and a year later. All the CRCLD responders continued to benefit from shunting at one week and one year after the procedure irrespective of the type of shunting they received. By comparison, none of the CRCLD non-responders showed any improvement a year after the shunting. In conclusion, CRCLD proved to be a safe and effective way to predict the effectiveness of shunting in patients with normal pressure hydrocephalus.

Measurement of cervical canal sagittal diameter in Chinese males with cervical spondylotic myelopathy

BACKGROUND

Cervical canal encroachment can be properly assessed from lateral cervical radiographs either by defining its magnification rate or by a ratio-method. Data of the latter obtained from Chinese males with cervical myelopathy were compared with the data of general population in different age groups.

METHODS

A total of 200 Chinese males were included in this study. Half of them had undergone decompressive procedures for cervical myelopathy, while the remaining 100 cases were volunteers. Sagittal diameters of cervical canal and vertebra were measured from C3 to C6 on lateral cervical radiographs, while ratios (Torg-Pavlov's ratios) of the two reflected the extent of sagittal canal encroachment. Cut-off values and discriminant rates of these parameters in different age groups were obtained by discriminant analysis. The tube-to-film distance was set as 40 inches.

RESULTS

In myelopathic group (age < 55 y/o), Torg-Pavlov's ratios, as expressed by mean +/- standard deviation, were 0.77 +/- 0.12 for C3, 0.75 +/- 0.14 for C4, 0.80 +/- 0.14 for C5, and 0.81 +/- 0.15 for C6. In control group (age < 55 y/o) the ratios were 0.94 +/- 0.12, 0.95 +/- 0.13, 0.97 +/- 0.13, and 0.97 +/- 0.13 respectively. In myelopathic group (age > or = 55 y/o), the ratios were 0.76 +/- 0.09, 0.71 +/- 0.10, 0.73 +/- 0.11, and 0.76 +/- 0.11; while in control group (age > or = 55 y/o), the ratios were 0.93 +/- 0.10, 0.89 +/- 0.09, 0.88 +/- 0.11, and 0.91 +/- 0.12 respectively. The cutoff values and their discriminant rates are also presented.

CONCLUSIONS

The differences of canal sagittal diameter as well as Torg-Pavlov ratio between myelopathic and control group of Chinese males in individual age group were statistically significant. It is concluded that congenitally narrow cervical canal is a major predisposing factor to cervical spondylotic myelopathy.

Measurement of Chinese lumbar pedicles: with special reference to transpedicular screw fixation

BACKGROUND

Thorough understanding of the morphometric parameters of the lumbar pedicles is essential for transpedicular screw fixation. The purpose of this study is to establish a database for proper spinal instrumentations in Chinese patients.

METHODS

A total of 764 pedicles (L2-S1) were measured from spinal computed tomography (CT) of 100 Chinese volunteers. Parameters related to transpedicular fixation include pedicle width (PW), pedicle transverse angle (PTA), pedicle angle measured from the entry point of Roy-Camille through the midpoint of the pedicle (PPA), screw insertion depths to the anterior cortex from the entry point of Roy-Camille along the line parallel to the midsagittal line (PPLP) and from the entry point of Magerl along the pedicle axis (PPLS).

RESULTS

The mean age of the volunteers was 46.2 years. The average PWs from L2 to S1 were: 0.85 +/- 0.15 cm for L2, 0.92 +/- 0.22 cm for L3, 1.19 +/- 0.24 cm for L4, 1.70 +/- 0.28 cm for L5 and 2.31 +/- 0.35 cm for S1. The average PTAs from L2 to S1 were: 13.9 degrees +/- 4.9 degrees for L2, 13.4 degrees +/- 5.1 degrees for L3, 16.2 degrees +/- 5.9 degrees for L4, 27.8 degrees +/- 7.2 degrees for L5 and 44.0 degrees +/- 8.4 degrees for S1. The average PPAs from L2 to S1 were: 5.3 degrees +/- 2.4 degrees for L2, 6.3 degrees +/- 2.2 degrees for L3, 7.2 degrees +/- 2.5 degrees for L4, 10.1 degrees +/- 3.6 degrees for L5 and 17.0 degrees +/- 4.8 degrees for S1. The average PPLPs from L2 to S1 were: 5.64 +/- 0.82 cm for L2, 5.05 +/- 0.62 cm for L3, 4.99 +/- 0.89 cm for L4, 4.42 +/- 0.77 cm for L5 and 4.23 +/- 0.72 cm for S1. The average PPLSs from L2 to S1 were: 5.75 +/- 0.72 cm for L2, 5.24 +/- 0.75 cm for L3, 5.27 +/- 0.84 cm for L4, 4.88 +/- 0.72 cm for L5 and 4.99 +/- 0.72 cm for S1.

CONCLUSIONS

Transpedicular screw fixation should be tailored on individual basis. Though variation exists, no sufficient evidence can be found to suggest major morphometric differences of the Chinese lumbar pedicles from the studies in the English literature.

Trunk muscle activation. The effects of torso flexion, moment direction, and moment magnitude

OBJECTIVES

This study was performed to quantify the electromyographic trunk muscle activities in response to variations in moment magnitude and direction while in forward-flexed postures.

METHODS

Recordings were made over eight trunk muscles in 19 subjects who maintained forward-flexed postures of 30 degrees and 60 degrees. In each of the two flexed postures, external moments of 20 Nm and 40 Nm were applied via a chest harness. The moment directions were varied in seven 30 degrees increments to a subject's right side, such that the direction of the applied load ranged from the upper body's anterior midsagittal plane (0 degree) to the posterior midsagittal plane (180 degrees).

RESULTS

Statistical analyses yielded significant moment magnitude by moment-direction interaction effects for the EMG output from six of the eight muscles. Trunk flexion by moment-direction interactions were observed in the responses from three muscles.

CONCLUSIONS

In general, the primary muscle supporting the torso and the applied load was the contralateral (left) erector spinae. The level of electromyographic activity in the anterior muscles was quite low, even with the posterior moment directions.