LOWER LIMB JOINT POSITION SENSE IN PATIENTS WITH TYPE II DIABETES MELLITUS

Diabetes mellitus (DM), of which type II has been described as an international epidemic, is a major cause of death. Diabetic peripheral neuropathy (PN) is a condition secondary to hyperglycemia, where progressive loss of peripheral nerve function, including sensory and motor functions, occurs over time. Early detection of PN-related impairments may be helpful for the management of patients with DM. Among the methods for the evaluation of these impairments, only that for joint position sense (JPS) requires both motor and sensory involvement. The purpose of the current study was to compare the JPS of the lower limb joints in patients with no or mild diabetic PN to those of normal controls both during weight-bearing (WB) and non-weight-bearing (NWB) conditions using 3D motion analysis methods. The results supported the hypothesis that in well controlled diabetic patients with no or mild PN, JPS deficits can be found only at the ankle joint during WB conditions, resulting in overestimation of dorsiflexion angles. This suggests that at the very early stage of development of diabetic PN, distal joint involvement precedes that of proximal joints. Early detection of these changes, through the assessment of the JPS for all the lower limb joints under both NWB and WB conditions, will be helpful for the development of clinical preventive and treatment programs for patients with DM, even if their glucose level are well controlled. Gait and balance training in these patients should emphasize proprioception training exercises during WB conditions.

EFFECTS OF KNEE OSTEOARTHRITIS ON BODY'S CENTER OF MASS MOTION IN OLDER ADULTS DURING LEVEL WALKING

Knowledge of the control of the body's dynamic stability in patients with knee osteoarthritis (OA) is helpful for the management of these patients and for the evaluation of treatment outcomes. The purpose of the current study was to investigate the dynamic stability of patients with knee OA during level walking using variables describing the motion of the body's center of mass (COM) and its relationship to the center of pressure (COP). Kinematic and kinetic data during level walking were obtained from 10 patients with bilateral knee OA and 10 normal controls using a motion analysis system and two forceplates. Compared to the normal controls, patients with knee OA exhibited normal COM positions and velocities at key instances of gait but with significant changes in COM accelerations. In the sagittal plane, adjustments to the anterioposterior acceleration of the COM throughout the complete gait cycle were needed for better control of the COM during the more challenging latter half of single leg stance. Diminished A/P COM–COP separation was also used to maintain body stability with reduced joint loadings. In the frontal plane, this was achieved by increasing the acceleration of the body's COM towards the stance leg. The more jerky motion of the body's COM observed may be a result of reduced ability associated with knee OA in the control of the motion of the COM. Strengthening of the muscles of the lower extremities, as well as training of the control of the COM through a dynamic balance training program, are equally important for the dynamic stability of patients with knee OA.

Acute disseminated encephalomyelitis that meets modified McDonald criteria for dissemination in space is associated with a high probability of conversion to multiple sclerosis in Taiwanese patients

BACKGROUND

Patients with acute disseminated encephalomyelitis (ADEM) may relapse and some may ultimately convert to multiple sclerosis (MS); however, no criteria that can predict MS conversion are available to date. Our aim was to describe the clinical and magnetic resonance imaging (MRI) features of patients with an initial ADEM attack and evaluate which MRI criteria can predict conversion to MS.

METHODS

We retrospectively reviewed the records of 36 patients diagnosed with ADEM. We determined clinical signs/symptoms, examined the cerebrospinal fluid (CSF), and performed brain MRI scans and compared the findings between patients who did and did not convert to MS.

RESULTS

Clinical signs/symptoms, and CSF analysis show no significant difference between the two groups. The rate of conversion to MS from ADEM in Taiwanese patients is low (11%) after a mean follow-up period of 28.36 months. Modified McDonald criteria were fulfilled in 19/36 patients: 21% (4/19) of those patients developed MS according to Poser criteria subsequently. Of the other patients (17/36) who did not fulfill these criteria, none converted to MS. (log rank test; P=0.027).

CONCLUSIONS

It is difficult to predict from initial clinical presentations to address which patients with ADEM will convert to MS. Patients with ADEM whose brain MRI findings met the modified McDonald criteria may have clinically isolated syndrome because they have a significantly higher probability of conversion to MS. In contrast, patients whose brain MRI findings did not meeting these criteria may be considered as having classic ADEM because they have a lower probability of conversion to MS.

Effects of the different frequencies of whole-body vibration during the recovery phase after exhaustive exercise

AIM

This study was to investigate the effects of vibration exercise on the oxygen consumption (VO2) and heart rate variability (HRV) during the recovery phase after exhaustive exercise.

METHODS

Twenty male college students volunteered as subjects to participate in the study. The subjects were randomly crossover assigned to perform three 10 min vibration exercises, namely non-vibration (CON, 0 Hz, 0 mm), low-frequency (LFT, 20 Hz, 0.4 mm) and high-frequency (HFT, 36 Hz, 0.4 mm) treatments immediately after an incremental exhaustive cycling exercise in separated days. The beat-to-beat HRV, blood lactate concentration and VO2 were measured during the 1-hour recovery phase. The time- and frequency-domain indices of HRV were analyzed to confirm the effects of vibration exercises on the cardiac autonomic modulation.

RESULTS

There were no significant differences on the VO2, HRV and blood lactate concentrations at 30th minute (post-30 min) or 60th minute (post-60 min) during the recovery phase among the three treatments. There were also no significant differences on the excess post-exercise oxygen consumption (EPOC) during the recovery phase among the treatments. However, the VO2 at post-30 min in CON and LFT were significantly higher than the baseline values, whereas the VO2 in HFT returned to resting condition at the post-30 min.

CONCLUSIONS

The results indicate that both low and high frequency vibration exercises could not improve the physiological recovery after exhaustive cycling exercise. However, the high frequency vibration exercise probably has a potential to facilitate the VO2 to return to the resting level during the recovery phase.

Symmetrical kinematic changes in highly functioning older patients post-stroke during obstacle-crossing

With the advances in stroke care, the number of high-functioning patients after stroke is increasing. However, existing clinical tools may not be sensitive enough to identify the residual deficits in these patients. The current study aimed to investigate the control of the pelvis, and the joints and end-point of the lower limbs in high-functioning older patients post-stroke during obstacle-crossing using motion analysis techniques. Twenty-four high-functioning older patients following unilateral stroke and fifteen healthy controls walked and crossed obstacles of three different heights. End-point variables (leading toe-clearance and trailing toe-obstacle distance) and crossing pelvic and joint angles were obtained for both limbs during leading limb crossing. Whether leading with the contralesional or ipsilesional limb, the stroke group exhibited significantly different joint kinematics from the controls mainly in the frontal and transverse planes, with greater leading toe-clearance, trailing toe-obstacle distance, and posterior pelvic tilt. None of the end-point and joint variables were significantly different between limbs. High-functioning patients post-stroke appeared to have acquired a specific symmetric kinematic strategy with increased leading toe-clearance during obstacle-crossing, most likely in order to prevent tripping. This symmetric strategy, possibly a consequence of brain reorganization, may help in performing functional activities during which symmetric performance between the contralesional and ipsilesional sides is required. Obstacle-crossing training with both limbs leading alternately may be helpful for the development of this symmetric strategy. It is suggested that computerized motion analysis of obstacle-crossing can be a sensitive assessment tool for distinguishing the motor performance between normal and high-functioning patients post-stroke.

Patients with type II diabetes mellitus display reduced toe-obstacle clearance with altered gait patterns during obstacle-crossing

Patients with type II diabetes mellitus (DM) have been reported to be at high risk of falls that may be further increased by the effects of challenging activities such as obstacle-crossing. The purpose of this study was to compare the end-point trajectory and joint kinematic and kinetic patterns of the lower extremities between healthy subjects and individuals with DM during obstacle-crossing with the leading limb. Fourteen patients with type II DM, with no to minimal peripheral neuropathy (PN), and 14 healthy controls walked and crossed obstacles of three different heights (10%, 20% and 30% of leg length) while kinematic and kinetic data were measured using a motion analysis system and two forceplates. Compared to normal, the DM group had similar walking speeds and horizontal footobstacle distances but significantly reduced leading toe-obstacle clearances, suggesting an increased risk of tripping over the obstacle. When the swing toe was above the obstacle, the DM group showed greater pelvic anterior tilt, stance ankle dorsiflexion, and smaller swing hip abduction, with reduced hip abductor moments but greater knee flexor and ankle plantarflexor and adductor moments. It is suggested that patients with type II DM, with no or minimal PN, should also be targeted for prevention of falls. Possible therapeutic interventions to decrease falls for those with DM may include strengthening of the knee flexors and ankle plantarflexor muscles, together with proprioception and balance training.

Generation of multi-octave-spanning laser harmonics by cascaded quasi-phase matching in a monolithic ferroelectric crystal

We report the generation of the second to the sixth harmonics of a fundamental frequency covering two and a half octaves in a multiply-periodically poled lithium tantalate crystal by cascaded quasi-phase-matched frequency mixing. A frequency comb that is composed of these harmonics will permit the synthesis of a train of periodic subcycle subfemtosecond pulses in a compact setting.

Broadband antireflective poly-Si nanosponge for thin film solar cells

Antireflective nanosponges are fabricated on polycrystalline silicon (poly-Si) thin films using Ag-nanoparticles (NPs) assisted etching. Crystal orientations and grain sizes of the poly-Si thin films are investigated for the poly-Si nanosponge formation and the resultant optical properties. The Ag-NPs assisted etching preferentially etches the poly-Si thin films along crystal orientation of [110]. A 400 nm thick poly-Si nanosponge reduces effective optical reflection of the poly-Si thin film with substrate crystal orientation of (110) and averaged grain size of 250 nm from 26 % to 3 % at the wavelengths ranging from 400 nm to 1000 nm. Carrier lifetimes were found to be 41 and 36 mus for poly-Si thin film and RTO-passivated nanosponges, respectively.

Clinical features, vascular risk factors, and prognosis for transient global amnesia in Chinese patients

BACKGROUND

Transient global amnesia (TGA) is an intriguing clinical syndrome that has not been studied in a series of Chinese patients.

METHODS

From 1989 to 1995, we observed 28 consecutive patients with TGA. Their clinical characteristics, risk factors, and outcome were retrospectively reviewed and analyzed.

RESULTS

There were 13 men and 15 women with a mean age of 62 years (range, 39 to 76). The duration of amnesic attack ranged from 20 minutes to 24 hours (mean, 8 hours), with the majority (76%) of attacks lasting for 2 to 12 hours. In 9 (32%) of the 28 patients, the TGA was triggered by a potential precipitating factor including bathing, emotional stress, and headache. The most prominent symptom exhibited by patients during an attack was repetitive questioning, which occurred in 21 (75%) of the 28 patients. No focal neurological abnormality was noted during or after the attack. Electroencephalograms were obtained in 26 patients after experiencing TGA, which showed nonspecific findings in 6 patients and were normal in 20. In 21 patients who had cranial computed tomography scans, cortical atrophy was found in 5 (24%), focal infarction in 4 (19%), and the results were negative in 12 (57%). Hypertension was the predominant vascular risk factor (11 cases, 39%), then hyperlipidemia (7 cases, 25%), and smoking (3 cases, 11%). No vascular risk factor was found in 13 patients (46%). Recurrent TGA was found in 5 patients (18%), and stroke in 2 (7%).

CONCLUSION

Our study largely confirms the demographic pattern, clinical characteristics, and prognosis of TGA patients reported from the western countries. Although the cause is uncertain, TGA is a relatively benign entity.

Clinical characteristics of multiple sclerosis in Taiwan: a cross-sectional study

This study reviewed the clinical characteristics of multiple sclerosis (MS) in Taiwanese patients from 1993 to 2001. Of the 75 MS patients with a mean age of onset of 35.6 +/- 12.6 years, the female-to-male ratio was 4.4 (61/14). In 42 (56%) optico-spinal MS (OS-MS) patients, the age of onset (37.6 +/- 11.1 years) tended to be older than conventional MS (C-MS) patients (33.1 +/- 14.1 years, P = 0.08). In 60 cerebrospinal fluid (CSF) specimens, raised IgG index (>0.7) and oligoclonal bands were noted in 26 (43.3%) and two (3.3%) cases, respectively. The frequency of raised IgG index was lower in OS-MS (31.3%) than in C-MS (57.1%, P = 0.07). The CSF total protein concentrations were significantly higher in OS-MS (64.5 mg/dL) than in C-MS (46.6 mg/dL, P = 0.047). The mean annual relapse rate was 54.1%, and was significantly higher within the first year (59.7%, P < 0.001). The mean annual relapse rate in OS-MS (62.7%) was significantly higher than in C-MS (41.2%, P=0.01). The differences in the annual relapse rate and total protein concentration in CSF between OS-MS and C-MS suggest probably two distinct immunopathogenesis. The higher first year relapse rate of MS patients in Taiwan may address the importance of early intervention with immunomodulatory therapy.

Apolipoprotein E, angiotensin-converting enzyme and kallikrein gene polymorphisms and the risk of Alzheimer's disease and vascular dementia

Lipoproteins and vascular factors may play roles in the development of Alzheimer's disease (AD) and/or vascular dementia (VaD). In this study, odd ratios (ORs) and 95% confidence intervals (CIs) for apolipoprotein E (APOE), angiotensin-converting enzyme (ACE), and kallikrein (KLK1) polymorphisms were computed to test their association with the disease by a case-control study. The risk of AD was significantly increased for individuals with APOE varepsilon4 allele (OR = 3.73, 95% CI = 2.38-5.98). The risk of AD was also significant for people with ACE DD genotype, D allele, or T-D haplotype [OR (95% CI) = 4.29 (1.96-10.23), 1.90 (1.35-2.70), or 2.91 (1.71-5.10), respectively]. The above association between ACE-VaD was also strong (p = 0.0012, 0.0050, 0.0007, respectively). Reporter constructs containing the -240 A or T allele displayed similar transcriptional activity in both HEK-293 and IMR-32 cells. Thus, another putative pathogenic marker that is linked with the Alu D allele might affect the risk of AD and VaD in Taiwan.

Heat shock protein 70 and tumor necrosis factor alpha in Taiwanese patients with dementia

This study was to determine whether polymorphisms of heat shock protein 70-1 (HSP70-1) and tumor necrosis factor alpha (TNF-alpha) are associated with the risk of Alzheimer's disease (AD) and vascular dementia (VaD). Using the criteria of the NINCDS-ADRDA and NINDS-AIREN, 125 AD patients, 57 VaD patients and 109 ethnically matched nondemented controls were enrolled. The HSP70-1 -110 A/C and TNF-alpha -1031 T/C, -863 C/A and -857 C/T polymorphisms were analyzed by means of genotype or haplotype association methods. None of the four genotypes examined showed a statistically significant difference in genotype distribution between the AD cases and controls. However, the HSP70-1 -110 CC genotype occurred more frequently among AD cases (p=0.0821; odds ratio: 2.08; 95% confidence interval, CI: 0.92-4.98). The overall genotype distribution among the VaD cases tended to be different at the HSP70-1 -110 and TNF-alpha -1031 sites (p=0.0604 and 0.0316, respectively). The HSP70-1 -110 CC genotype was more frequent (p=0.0459), and the association of the -110 CC genotype with VaD was evident (p=0.0207; odds ratio: 3.22; 95% CI: 1.20-8.87). The more frequent TNF-alpha -1031 TC genotype (p=0.0614) was also evidently associated with VaD (p=0.0209; odds ratio: 2.32; 95% CI: 1.14-4.78). Multivariate analysis demonstrated the synergistic effect of the HSP70-1 -110 CC and TNF-alpha -1031 TC/CC genotypes on VaD (p=0.0091; odds ratio: 10.09; 95% CI: 2.01-75.97). Haplotype analysis among TNF-alpha -1031, -863, -857 sites revealed that -1031C-857C may act as a risk haplotype among VaD cases (p=0.0132, odds ratio: 2.26; 95% CI: 1.19-4.33). Our results suggest a potential protective role for HSP70 in both VaD and AD, whereas TNF-alpha may act as a risk factor only for VaD, and not for AD.

Enhanced sodium absorption in middle ear epithelial cells cultured at air-liquid interface

CONCLUSION

As we demonstrated previously that transcription of alpha-ENaC was correlated with oxygen tension in the culture medium, this study suggests that the increase in alpha-ENaC expression observed under ALI conditions may result from greater oxygenation of ME cells.

OBJECTIVE

The physiology of the middle ear (ME) is primarily concerned with keeping the cavities fluid-free, to allow transmission of sound vibrations from the eardrum to the inner ear. ME epithelial cells are thought to play a key role in this process as they actively absorb sodium and water in order to clear any excess fluid present in the cavities.

MATERIAL AND METHODS

As an air-liquid interface (ALI) model has been shown to improve differentiation and enhance sodium absorption in other respiratory epithelia, we established an ALI model for ME cells.

RESULTS

ME cells cultured under ALI conditions exhibited a fourfold increase in sodium absorption, which was not related to either a metabolic effect or to enhanced morphological differentiation, but instead to an increase in expression of the alpha-subunit of the epithelial sodium channel (alpha-ENaC).

Prenatal three-dimensional ultrasound and magnetic resonance imaging evaluation of a fetal oral tumor in preparation for the ex-utero intrapartum treatment (EXIT) procedure

Recent attempts at predelivery management of obstructed fetal airways have focused on the EXIT (ex-utero intrapartum treatment) procedure, which allows sufficient time to secure the fetal airway through preservation of uteroplacental gas exchange. We report a fetus with an exophytic oral tumor noted at 34 weeks of gestation. In this case, three-dimensional (3D) ultrasound allowed a complete and interactive evaluation of the tumor and related facial anatomy, and confirmed that access to the fetal airway was unlikely during delivery. Fetal magnetic resonance imaging (MRI) further demonstrated that the tumor originated in the nasopharynx and obstructed the upper airway. Both imaging results led to a final decision to offer an EXIT procedure for the neonate. At 36 weeks' gestation, a successful EXIT procedure was performed to reduce the risk of respiratory distress immediately after birth. This report highlights the value of 3D ultrasound and MRI as essential prerequisites for optimization of the triage process in selecting EXIT candidates.

Dynamic evaluation of 18F-FDG uptake by microPET and whole-body autoradiography in a fibrosarcoma-bearing mouse model

BACKGROUND AND PURPOSE

Fluorine-18-2-deoxy-D-glucose (18F-FDG) has been used in the clinic as a diagnostic radiotracer for monitoring many kinds of tumors, but its value for monitoring fibrosarcoma is not well established.

METHODS

In this study, the uptake of 18F-FDG in a fibrosarcoma-bearing mouse model was evaluated using the high resolution positron emission tomography (PET) system microPET. Tumor cells were implanted in 3 FVB/N mice, and static microPET scanning was performed on day 1, 7, 12 and 15 after implantation. A dynamic microPET image was scanned on day 12 to determine the 18F-FDG uptake in 3 other tumor-bearing mice. Time-activity curves were plotted by drawing regions of interest in the tumor, liver, kidneys and muscles. The mice were sacrificed after dynamic microPET imaging and whole-body autoradiography (WBAR) was performed. For biodistribution study, 9 tumor-bearing mice, 3 per experimental group, were studied at 3 time points and the results were compared with the static microPET images.

RESULTS

MicroPET images suggested that 18F-FDG could be used to monitor the growth of tumors 7 days after implantation. Dynamic scans of 18F-FDG uptake reached a plateau in the tumor after 20 minutes on day 12 after implantation. Both microPET and WBAR revealed evidence of tumor necrosis. The results of biodistribution and WBAR agreed with those from microPET images.

CONCLUSION

MicroPET was useful for monitoring the growth of fibrosarcoma and determination of the maximal uptake time point of 18F-FDG in tumors in this tumor-bearing mouse model.

The enhancement of nuclear receptor transcriptional activation by a mouse actin-binding protein, alpha actinin 2

The p160 coactivators, steroid receptor coactivator 1, glucocorticoid receptor interacting protein 1 (GRIP1) and the activator of thyroid and retinoic acid receptor, have two activation domains, AD1 and AD2, which transmit the activation signal from the DNA-bound nuclear receptor to the chromatin and/or transcription machinery. In screening for mammalian proteins that bind the AD2 of GRIP1, we identified a mouse actin-binding protein, alpha actinin 2 (mACTN2). mACTN2 was expressed in the heart, skeletal muscle, lung, brain and testis, but there was no expression in the spleen, liver or kidney. Interestingly, the expression level of mACTN2 in the developing embryo depended on the embryonic stage. We further demonstrated that mACTN2 could enhance two transactivation activities of GRIP1, which in turn could enhance the homodimerization of mACTN2. Importantly, mACTN2 not only served as a primary coactivator for androgen receptor, estrogen receptor and thyroid receptor activities, but also acted synergistically with GRIP1 to enhance these nuclear receptor (NR) functions. However, the NR binding motif, LXXLL, conserved in mACTN2 and other actinin family proteins, might be a dispensable domain for its coactivator roles in NRs. These findings suggested that mACTN2 might play an important role in GRIP1-induced NR coactivator functions.

A feasibility study on the predictive emission monitoring system applied to the Hsinta power plant of Taiwan Power Company

The continuous emission monitoring system (CEMS) can monitor flue gas emissions continuously and instantaneously. However, it has the disadvantages of enormous cost, easily producing errors in sampling periods of bad weather, lagging response in variable ambient environments, and missing data in daily zero and span tests and maintenance. The concept of a predictive emission monitoring system (PEMS) is to use the operating parameters of combustion equipment through thermodynamic or statistical methods to construct a mathematic model that can predict emissions by a computer program. The goal of this study is to set up a PEMS in a gas-fired combined cycle power generation unit at the Hsinta station of Taiwan Power Co. The emissions to be monitored include nitrogen oxides (NOx) and oxygen (O2) in flue gas. The major variables of the predictive model were determined based on the combustion theory. The data of these variables then were analyzed to establish a regression model. From the regression results, the influences of these variables are discussed and the predicted values are compared with the CEMS data for accuracy. In addition, according to the cost information, the capital and operation and maintenance costs for a PEMS can be much lower than those for a CEMS.

Cochlear electrical stimulation: influence of age of implantation on Fos immunocytochemical reactions in inferior colliculi and dorsal cochlear nuclei of the rat

The influence of age at the time of implantation of a stimulating electrode unilaterally in the inner ear on central auditory pathways was investigated in rats deafened shortly after birth. Immunoreactivity for Fos served as a functional marker of neuronal activity. Electrodes were implanted in the left cochlea of rats aged 3 weeks or 4 months. Stimulation lasted 45 minutes, then rats were sacrificed and tissues processed for immunocytochemistry. The younger animals showed significantly more neurons with Fos immunoreactivity bilaterally in the dorsal cochlear nuclei (DCN) and inferior colliculi (IC) than the older rats or control animals with normal hearing receiving the same stimulation. Activity was more prominent in the left DCN and right IC. The results show that electrical stimulation of the inner ear is more effective in younger animals in eliciting gene expression associated with development of a functional network in the auditory pathways. This suggests that deaf children should be provided with cochlear implants as early as possible.

Specific IgA antibodies to recombinant early and nuclear antigens of Epstein-Barr virus in nasopharyngeal carcinoma

Nasopharyngeal carcinoma is a common cancer in Taiwan. The Epstein-Barr virus (EBV) is closely associated with nasopharyngeal carcinoma. The sera of patients with nasopharyngeal carcinoma have IgA antibodies to a variety of EBV latent and replicated antigens. Recently, an enzyme-linked immunosorbent assay (ELISA) kit, combining both the EBV early antigen (EA) and nuclear antigen (EBNA-1) became commercially available. The purpose of this study was to assess its clinical application. Serum IgA antibodies to the EBV EA and EBNA-1 were measured by using the ELISA kit in various groups of subjects. Fluorescence antibody (FA) tests against EBV viral capsid antigen (VCA) and EA in the IgA and IgG classes were also studied for comparison. The DNA content analysis was also carried out to investigate the association with IgA antibody titres using ELISA. The sensitivity, specificity and accuracy of the ELISA test were 98.1%, 81.8% and 88.7% respectively. It was far better than any FA tests. The IgA antibody titres showed no association with DNA content analysis. Univariate analysis of various factors revealed that IgA antibody titres were statistically correlated to N stage (P = 0.0291) and M status (P = 0.001). However, there was no association with the age, sex, T stage and clinical stage. Multivariate analysis of various factors was found to be statistically significant in patients with T4 (P = 0.0133), N3 (P = 0.0244) or M1 (P = 0.001) respectively. Serial testing of antibody titres in 22 previously untreated patients found a trend of decreasing IgA antibody titres after initial treatment when the tumours disappeared (P = 0.0358). The ELISA kit to identify specific IgA antibodies with the combination of EBV EA and EBNA-1 recombinant antigens has high sensitivity and acceptable specificity and accuracy in the diagnosis of nasopharyngeal carcinoma. This assay should be useful for early diagnosis and mass screening of patients.

Failure of grommet insertion in post-irradiation otitis media with effusion

Nasopharyngeal carcinoma (NPC) survivors with post-irradiation otitis media with effusion (OME; 100 ears) were divided into 2 groups. One group underwent grommet insertion, and the other group was treated by repeated myringotomies plus aspiration to evaluate the outcome of the OME. Computed tomography, magnetic resonance imaging, audiometry, and local checks of the ear, nose, and nasopharyngeal fields were performed to evaluate the sinus and middle ear conditions over a long-term (more than 10 years) follow-up period. The results in these NPC survivors with OME indicated that the prevalence of middle ear complications in the myringotomized group (33%) was less than that in the grommeted group (90%). Grommets alone cannot eradicate inflammation outside the middle ear cavity, but rather, they can aggravate it by superinfection. We therefore recommend that controlling the radiation-induced inflammation in areas such as the ears, nose, sinuses, and nasopharynx is most important. In conclusion, post-irradiation OME should be treated in a different way from conventional OME. Restated, grommet insertion is contraindicated in post-irradiation OME.

Accumulation of mitochondrial DNA deletions in human oral tissues -- effects of betel quid chewing and oral cancer

Accumulation of mitochondrial DNA (mtDNA) mutations in human tissues has been associated with intrinsic aging and environmental insult. Recently, mtDNA mutations have been detected in various tumors, including head and neck tumors. However, the factors affecting the occurrence and accumulation of mtDNA deletions in tumor tissues are poorly understood. In Taiwan, betel quid chewing is a major risk factor for oral cancer. Using polymerase chain reaction (PCR) techniques, we examined large-scale deletions of mtDNA in 53 pairs of tumor and non-tumor oral tissues from the patients with or without betel quid chewing history. The results revealed that irrespective of the history of betel quid chewing, the incidences of the 4977bp deletion and other deletions of mtDNA were lower in the tumor portion as compared with the non-tumor portion. The average proportions of the 4977bp deleted mtDNA in the tumor tissues of the betel quid chewers and non-betel quid chewers were 13- and 5-fold, respectively, lower than those in the corresponding non-tumor tissues. Moreover, the average proportion of 4977bp deleted mtDNA was significantly higher (P<0.05) in the non-tumor oral tissues of the patients with betel quid chewing history than that of the patients without the history of betel quid chewing. These results suggest that betel quid chewing may increase mtDNA mutation in human oral tissues and that accumulation of mtDNA deletions and subsequent cytoplasmic segregation of these mutations during cell division could be an important contributor to the early phase of oral carcinogenesis.

Computed tomography-guided percutaneous transpedicular biopsy of the thoracic spine

BACKGROUND

Despite the recent, widespread use around the world of computed tomography (CT)-guided spinal biopsy for presurgical evaluation, its use has remained uncommon in Taiwan. Using 9 patients, we attempted to evaluate the safety of its use for the thoracic spine biopsy.

METHODS

In the past 3 years (May 1996 to May 1999), 9 patients with known thoracic or multiple spinal lesions underwent CT-guided biopsy. The patients comprised 4 men and 5 women; with ages ranging between 28 and 85 years. For the transpedicular approach, patients were laid prone on the CT table. A trephine bone biopsy needle set was used after local anaesthesia. The specimens obtained had tissue pathology and/or bacterial/tuberculosis (TB) culture.

RESULTS

Excellent results were achieved in 8 of the 9 patients, with no significant procedure-related complications. Among them, 2 were diagnosed as metastatic carcinomas; 3 as osteoporotic compression fractures; 2 were proved to be bacterial or tuberculosis spondylitis and the last one was a healing fracture.

CONCLUSION

CT-guided transpedicular trephine biopsy of the thoracic spine is a safe and effective method for preoperative evaluation of various thoracic spinal disorders. Based on the biopsy results, more effective treatment regimens were prescribed and, in turn, better outcomes were expected.