Biomedical subjects

H J Chen

Publications and source records attributed to H J Chen.

At least 37 records · Page 2Linked to original sources

PubMed2001

Streptococcal brain abscess: analysis of clinical features in 20 patients.

BACKGROUND: To assess the clinical features and therapeutic outcomes of brain abscess caused by streptococci. METHODS: Twenty patients, 18 males and 2 females, aged 3 to 76 years, collected over a 14-year period, have been identified at Kaohsiung Chang Gung Memorial Hospital. RESULTS: Among these 20 patients, 13 had viridans streptococci infection alone, one had non-A, non-B, and non-D streptococci infection alone, and the other 6 had mixed infections each including streptococci. The locations of all of the abscesses were supratentorial. Among these patients, 18 had a single abscess and 2 had multiple abscesses. Underlying conditions were common in our patients, including head trauma, heart disease, otopharyngeal infection, and medical procedures. Nineteen patients were treated surgically and 1 was treated with antibiotics alone. Nineteen survived and 1 died, with an overall mortality rate of 5%. CONCLUSION: The clinical presentations and underlying conditions varied according to the different streptococcal species. Streptococcal brain abscesses accounted for 17% of our cases with brain abscesses, and 30% of our streptococcal infections had polymicrobial infections. Although streptococcal brain abscesses were commonly associated with otopharyngeal infections or infectious endocarditis, they also appeared to be often related to neurosurgical events or medical procedures in recent years. Based on our study, prognosis is favorable with early diagnosis and prompt treatment.

Adolescent↗

PubMed2001

Non-traumatic cerebrospinal fluid rhinorrhea indirectly caused by remote brain tumor: a case report and review of the literature.

Non-traumatic cerebrospinal fluid rhinorrhea indirectly caused by a remote brain tumor has rarely been reported. Here we describe a case of non-traumatic cerebrospinal fluid rhinorrhea that occurred as the initial symptom of a posterior falx meningioma. In addition, based on the period of occurrence of cerebrospinal fluid rhinorrhea before or after the tumor operation, we introduced a novel classification for these cases into pre-treatment and post-treatment types. The findings of the present case and the results of our literature research suggest that different treatments should be used for patients with these two types of non-traumatic cerebrospinal fluid rhinorrhea resulting from remote brain tumor. After tumor excision, patients of the pre-treatment type may receive conservative management or cerebrospinal fluid shunting, while patients of the post-treatment type need direct repair of the fistula.

Adult↗

PubMed2001

Antioxidant activities of trypsin inhibitor, a 33 KDa root storage protein of sweet potato (Ipomoea batatas (L.) Lam cv. Tainong 57).

Trypsin inhibitors (TIs), root storage proteins, were purified from sweet potato (Ipomoea batatas[L.] Lam cv. Tainong 57) roots by trypsin affinity column according to the methods of Hou and Lin (Plant Sci. 1997, 126, 11-19 and Plant Sci. 1997, 128, 151-158). A single band of 33 kDa TI was obtained by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels. This purified 33 kDa TI had scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. There was positive correlation between scavenging effects against DPPH (2 to 22%) and amounts of 33 kDa TI (1.92 to 46 pmol). The scavenging activities of 33 kDa TI against DPPH were calculated from linear regression to be about one-third of those of glutathione between 5 and 80 pmol. Using electron paramagnetic resonance (EPR) spectrometry for hydroxyl radical detection, it was found that 33 kDa TI could capture hydroxyl radical, and the intensities of EPR signal were significantly decreased from 1.5 to 6 pmol of 33 kDa TI compared to those of the controls. It is suggested that 33 kDa TI, one of the sweet potato root storage proteins, may play a role as an antioxidant in roots and may be beneficial to health when it is consumed.

Antioxidants↗

PubMed2001

Antioxidant activities of dioscorin, the storage protein of yam (Dioscorea batatas Decne) tuber.

Dioscorin, the storage protein of yam (Dioscorea batatas Decne) tuber (which is different from dioscorine found in tubers of Dioscorea hirsuta), was purified to homogeneity after DE-52 ion exchange column according to the methods of Hou et al. (J. Agric. Food Chem. 1999, 47, 2168-2172). A single band of 32 kDa dioscorin was obtained on a sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel with 2-mercaptoethanol treatment. This purified dioscorin was shown by spectrophotometric method to have scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in a pH-dependent manner. There is a positive correlation between scavenging effects against DPPH (8-46%) and amounts of 32 kDa dioscorin (5.97-47.80 nmol) added in Tris-HCl buffer (pH 7.9), which are comparable to those of glutathione at the same concentrations. Using electron paramagnetic resonance (EPR) spectrometry for DPPH radical detection, it was found that the intensities of the EPR signal were decreased by 28.6 and 57 nmol of 32 kDa dioscorin in Tris-HCl buffer (pH 7.9) more than in distilled water compared to controls. EPR spectrometry was also used for hydroxyl radical detection. It was found that 32 kDa dioscorin could capture hydroxyl radical, and the intensities of the EPR signal were significantly decreased dose-dependently by 1.79-14.32 nmol of 32 kDa dioscorin (r = 0.975) compared to the control. It is suggested that 32 kDa dioscorin, the storage protein of yam tuber, may play a role as antioxidant in tubers and may be beneficial for health when people take it as a food additive or consume yam tubers.

Antioxidants↗

PubMed2001

Cytotoxic dolabellane diterpenes from the Formosan soft coral Clavularia inflata.

Six new cytotoxic dolabellane diterpenes, (1R,12R)-dolabella-4(16),7,10-triene-3,13-dione (1), (1R*,7R*,8S*,12R*)-dolabella-4(16),10-diene-7,8-epoxy- 3,13-dione (2), (1R*,10R*,11S*,12R*)-dolabella-4(16),7-diene-10,11-epoxy-3,13-dione (3), (1R)-dolabella-4(16),7,11(12)-triene-3,13-dione (4), (1R*,3R*)-3-hydroxydolabella-4(16),7,11(12)-triene-3,13-dione (5), and (1R*,7R*)-7-hydroperoxydolabella-4(16),8(17),11(12)-triene-3,13-dione (6), have been isolated from the Formosan soft coral Clavularia inflata. The structures of compounds 1-6 were determined by 1D and 2D spectral analysis, and their cytotoxicity against selected cancer cells was measured in vitro.

Animals↗

PubMed2001

8-Nitroxanthine, an adduct derived from 2'-deoxyguanosine or DNA reaction with nitryl chloride.

Activated phagocytic cells generate reactive nitrogen species, including nitryl chloride and peroxynitrite, for host defense against invading pathogens. It has been proposed that these reactive nitrogen species may cause DNA damage and thus contribute to the multistage carcinogenesis process associated with chronic infections and inflammation. Previous studies showed that peroxynitrite reacted with guanine, 2'-deoxyguanosine, or DNA forming 8-nitroguanine. We herein report formation of 8-nitroxanthine as the major nitration product in reactions of 2'-deoxyguanosine or calf thymus DNA with nitryl chloride produced by mixing nitrite with hypochlorous acid, and 8-nitroguanine was a minor product in these reactions. 8-Nitroxanthine was characterized by its NMR and laser desorption ionization mass spectra and by deamination of 8-nitroguanine. Formation of 8-nitroxanthine was also detected by xanthine reaction with various reactive nitrogen species, including nitryl chloride, peroxynitrite, nitronium tetrafluoroborate, and heated nitric and nitrous acid. The identity of 8-nitroxanthine in nitryl chloride-treated dG and DNA was confirmed by co-injection with synthetic 8-nitroxanthine and by its reduction to 8-aminoxanthine. Levels of 8-nitroxanthine and 8-nitroguanine in these reactions were quantified by reversed-phase HPLC with photodiode array detection. Once formed, 8-nitroxanthine was spontaneously removed from DNA with a half-life of 2 h at 37 degrees C and pH 7.4. Therefore, 8-nitroxanthine might be an important DNA lesion derived from reactive nitrogen species in vivo.

Chromatography, High Pressure Liquid↗

PubMed2001

Analysis of 3,N(4)-ethenocytosine in DNA and in human urine by isotope dilution gas chromatography/negative ion chemical ionization/mass spectrometry.

The promutagenic etheno DNA adducts have been detected in tissue DNA of rodents and humans from various exogenous and endogenous sources. While other etheno DNA adducts have been detected and quantified by isotope dilution gas chromatography/negative ion chemical ionization/mass spectrometry (GC/NICI/MS), similar analysis for 3,N(4)-ethenocytosine (epsilonCyt) has not been available. In this report, a GC/NICI/MS assay was developed for detection and quantification of epsilonCyt in DNA and in human urine samples. The stable isotope of epsilonCyt with 7 mass units higher than the normal epsilonCyt was synthesized and used as internal standard of the assay. The adduct-enriched fraction of DNA hydrolysate was derivatized with pentafluorobenzyl bromide before GC/NICI/MS analysis with selective ion monitoring at [M - 181](-) fragments of pentafluorobenzylated epsilonCyt and its isotope analogue. One femtogram (S/N > 40) of pentafluorobenzylated epsilonCyt was detected when injected on column with selective ion monitoring mode. The limit of quantification for the entire assay was 7.4 fmol of epsilonCyt, which was approximately one thousand times lower than that of the HPLC/fluorescence assay for the nucleoside 3,N(4)-etheno-2'-deoxycytidine in DNA. Analysis of chloroacetaldehyde-treated calf thymus DNA by both GC/NICI/MS and HPLC/fluorescence methods provided similar adduct levels and thus verified the assay. This GC/NICI/MS method was used for analysis of epsilonCyt in two smokers' urine samples and the average level of epsilonCyt was 101 +/- 17 pg/mL/g of creatinine. Thus, quantification of epsilonCyt in DNA and in urine by this highly specific and ultrasensitive isotope dilution GC/NICI/MS assay may facilitate research on the role of epsilonCyt in carcinogenesis and in cancer development.

Animals↗

PubMed2001

Early prediction of aphasia outcome in left basal ganglia hemorrhage.

OBJECTIVES: The independent predictors of aphasia outcome for patients with left basal ganglia hemorrhage were evaluated. PATIENTS AND METHODS: We included 140 patients of 1,036 patients with spontaneous intracerebral hemorrhage admitted to our hospital from January 1993 through December 1997. Aphasia was assessed using the aphasia scale of the Scandinavian stroke scale. Univariate and step-wise logistic regression analyses were performed to assess the relationships between the initial aphasia score, age, gender, blood volume, locations of hematoma and aphasia outcome. RESULTS: Step-wise logistic regression analysis revealed that the following two factors were independently associated with the final aphasia outcome: initial aphasia score (P < 0.0001) and location of hematoma involving the posterior limb of the internal capsule (P = 0.004). CONCLUSIONS: A particularly high likelihood of poor aphasia outcomes of patients with left basal ganglia hemorrhage are predicted in those who have poor initial aphasia score and whose brain computed tomography shows the hematoma involves the posterior limb of the internal capsule.

Aged↗

PubMed2001

Reversible bilateral internuclear ophthalmoplegia following head injury.

PURPOSE: Internuclear ophthalmoplegia is a syndrome produced by a lesion in the medial longitudinal fasciculus. Head trauma is a rare cause. We describe an unusual case of bilateral internuclear ophthalmoplegia as an isolated sequela following a minor head injury that resolved completely 3 months later. METHODS: Case report. Magnetic resonance images. RESULTS: A 34-year-old male developed typical bilateral internuclear ophthalmoplegia after closed head injury. Attempted convergence was normal. Magnetic resonance imaging clearly delineated the focal hemorrhage in the medial longitudinal fasciculus region by showing a small bright lesion in the pontomesencephalic junction in the midline on both T2-weighted and T1-weighted images. The diplopia resolved 4 weeks later. Three months after the accident, his versions were completely normal. CONCLUSION: Isolated internuclear ophthalmoplegia should be considered in the differential diagnosis when one encounters an adduction deficit in a recently traumatized patient. Magnetic resonance images enhance the ability to correlate the clinical findings with the anatomic lesion.

Accidents, Traffic↗

PubMed2001

One-stage posterior decompression and fusion using a Luque rod for occipito-cervical instability and neural compression.

STUDY DESIGN: Original article. OBJECTIVE: The authors present seven cases who underwent one-stage suboccipital, C1 and/or C2 posterior decompression and fusion by Luque rod, wiring and autogenic bone graft for occipito-cervical instability and neural compression. SETTING: Chang Gung University and Medical Center at Kaohsiung, Taiwan. METHOD: Since January 1996, 20 cases of craniovertebral and upper cervical spinal instability were encountered. Seven of these cases had no neurological improvment under Cone-Barton Skeletal traction. Imaging studies revealed poor reduction with persistent neural compression. One patient underwent unsuccessful anterior trans-oral vertebrectomy for decompression. All patients underwent posterior suboccipital craniectomy, C1 and/or C2 laminectomy for decompression. Contoured Luque rod with wiring and autogeneic bone graft was used for craniocervical fusion. After surgical treatment, halo-vest or sterno-occipito-mandibular immobilizer (SOMI) was used for 3-6 months. RESULTS: Suboccipital craniectomy and C1 laminectomy could afford a 30-50% increment of anteroposterior diameter in the neural canal and effective decompression of the low medulla and cord. All patients made neurological improvement. The ASIA-MIS scores improved from pre-operative 49 (mean) to 78. Four patients can walk without any support. There were no major complications except for one case requiring readjustment of the halo-vest brace. CONCLUSION: The authors recommend this procedure as one choice for relieving craniocervical instability with neurological compromise. A programmed rehabilitation will afford better neurological improvement.

Adult↗

PubMed2001

Linear accelerator based radiosurgery as a salvage treatment for skull base and intracranial invasion of recurrent nasopharyngeal carcinomas.

Nasopharyngeal carcinoma is a common disease entity in Taiwan. It can spread in the prestyloid, retrostyloid compartments, parapharyngeal space, and skull base, and induce paralysis of cranial nerves. We have treated more than 1,500 cases in the past 14 years. Since 1994, we have treated 11 cases of nasopharyngeal carcinomas with skull base invasion by linear accelerator-based stereotactic radiosurgery. There were six male and five female patients. The mean age was 48.4 years. Seven patients had symptoms of low cranial nerves. For these patients, conformal radiotherapy plus brachytherapy was used for the masses beyond the skull base. Stereotactic radiosurgery with a dose of 10 Gy to 19 Gy for one treatment was used for the masses invading the skull base. Eight patients died in follow-up periods from 5 months to 2 years 7 months. Approximately half of patients revealed good response of tumor to radiosurgery. Two patients demonstrated no response of tumors to radiosurgery. Stereotactic radiosurgery may be an adjuvant treatment for recurrent nasopharyngeal carcinomas with skull base and intracranial invasion.

Adult↗

PubMed2001

Clinical experiences in neuronavigation.

We have successfully used a navigation system in more than 120 neurosurgical operations for past two years. The neuronavigation system provides high levels of mechanical accuracy in surgical localization, especially for small deep-seated masses or epileptic foci, surgical planning for intrinsic and extrinsic brain tumors, and arteriovenous malformation and guidance of instrumentation of spinal surgery. The ages of the patients were from 12 months to 75 years. The sex distribution was equal. Computed tomography or magnetic resonance imaging with 2-3 mm thick slices were employed for image guidance. The clinical experiences included 50 cases of deep-seated mass, 50 cases of surgical planning for tumor or vascular mass excision and 20 cases of spinal instrumentation treatment. There were no mechanical failures. Neuronavigation definitely provides a good technology in frameless brain and spinal surgeries.

Brain Neoplasms↗

PubMed2001

Hypertensive caudate hemorrhage prognostic predictor, outcome, and role of external ventricular drainage.

BACKGROUND AND PURPOSE: The purpose of the present study was to analyze the outcome and outcome predictors of caudate hemorrhage and role of external ventricular drainage in acute hydrocephalus. METHODS: Clinical data from 36 consecutive patients with hypertensive caudate hemorrhage was used in the present study. Age, gender, volume of parenchymal hematoma, hematoma in the internal capsule, initial Glasgow Coma Scale (GCS), hydrocephalus, severity of intraventricular hemorrhage, and hemorrhagic dilatation of the fourth ventricle were analyzed for effect on outcome. Effect of external ventricle drainage for hydrocephalus was evaluated by comparing preoperative and postoperative GCS scores. RESULTS: By univariate analyses, poor outcome was associated with a poor initial GCS score (P=0.016), hydrocephalus (P<0.001), intraventricular hemorrhage severity (P<0.01), and hemorrhagic dilatation of the fourth ventricle (P=0.02). By multivariate analysis, stepwise logistic regression revealed that hydrocephalus was the only independent prognostic factor for poor outcome (P<0.001). Postoperative 48-hour GCS score was better than the preoperative score by use of paired-sample t test (P<0.001). CONCLUSIONS: Hydrocephalus is the most important predictor of poor outcome. External ventricular drainage response for hydrocephalus was good in the present study, whereas an early decision should be made regarding preoperative neurological condition.

Basal Ganglia Hemorrhage↗

PubMed2001

Superior sagittal sinus thrombosis induced by thyrotoxicosis. Case report.

There is a wide variety of disorders associated with thrombosis of the superior sagittal sinus (SSS), including infectious disease. noninfectious conditions such as vasculitis and hypercoagulable states, and complications arising from pregnancy or use of oral contraceptive medications. Despite these well-defined associations, approximately 25% of the cases remain idiopathic. In this article the authors describe a patient who was found to have SSS thrombosis while experiencing a thyrotoxic phase of Graves disease. The patient presented with intracerebral hemorrhage, subarachnoid hemorrhage, seizure, coma, a raised fibrinogen concentration, low protein C activity, and atrial fibrillations. Thrombolysis was successfully performed despite the coexistence of thrombosis and intracranial hemorrhage. Patients with thyrotoxicosis and a diffuse goiter may be predisposed to the development of SSS thrombosis, as a result of hypercoagulation and stasis of local venous blood flow. In the present case, a patient in whom thrombosis coexisted with intracranial hemorrhage was successfully treated using thrombolytic therapy.

Carotid Arteries↗

PubMed2001

Intraspinal osteolipoma. Case report.

Lipomatous tumors can contain uncommon or rare components (such as fibrolipoma or angiolipoma) that may result in the development of symptoms. To the best of the authors' knowledge, lipoma associated with an osseous component has not been previously reported. A case of intraspinal extradural tumor composed of both adipose and bone tissue is presented. Current theories on the cause of lipoma with an osseous component are discussed. The tumor was histologically confirmed to be an osteolipoma, and the patient recovered well after resection.

Adult↗

PubMed2001

Associated change in plantar temperature and sweating after transthoracic endoscopic T2-3 sympathectomy for palmar hyperhidrosis.

OBJECT: Transthoracic endoscopic T2-3 sympathectomy is currently the treatment of choice for palmar hyperhidrosis. Compensatory sweating of the face, trunk, thigh, and sole of the foot was found in more than 50% of patients who underwent this procedure. The authors conducted this study to investigate the associated intraoperative changes in plantar skin temperature and postoperative plantar sweating. METHODS: One hundred patients with palmar hyperhidrosis underwent bilateral transthoracic endoscopic T2-3 sympathectomy. There were 60 female and 40 male patients who ranged in age from 13 to 40 years (mean age 21.6 years). Characteristics studied included changes in palmar and plantar skin temperature measured intraoperatively, as well as pre- and postoperative changes in plantar sweating and sympathetic skin responses (SSRs). In 59 patients (59%) elevation of plantar temperature was demonstrated at the end of the surgical procedure. In this group, plantar sweating was found to be exacerbated in three patients (5%); plantar sweating was improved in 52 patients (88.1%); and no change was demonstrated in four patients (6.8%). In the other group of patients in whom no temperature change occurred, increased plantar sweating was demonstrated in three patients (7.3%); plantar sweating was improved in 20 patients (48.8%); and no change was shown in 18 patients (43.9%). The difference between temperature and sweating change was significant (p = 0.001). Compared with the presympathectomy rate, the rate of absent SSR also significantly increased after sympathectomy: from 20 to 76% after electrical stimulation and 36 to 64% after deep inspiration stimulation, respectively (p < 0.05). CONCLUSIONS: In contrast to compensatory sweating in other parts of the body after T2-3 sympathetomy, improvement: in plantar sweating was shown in 72% and worsened symptoms in 6% of patients. The intraoperative plantar skin temperature change and perioperative SSR demonstrated a correlation between these changes.

Adolescent↗

PubMed2001

Atlantoaxial stability in ossiculum terminale. Case report.

The authors describe a patient with ossiculum terminale. Thin-section three-dimensional computerized tomography reconstructions, magnetic resonance images, and radiographs of the cervical spine were obtained to evaluate the atlantoaxial stability and structures of the ossiculum terminale. Bone had formed between the ossicles and the body of the odontoid process, and good atlantoaxial stability was clearly demonstrated.

Adult↗

PubMed2001

Hypocomplementemic urticarial vasculitis, jaccoud's arthropathy, valvular heart disease, and reversible tracheal stenosis: a surfeit of syndromes.

We describe a patient who, during 29 years of observation, manifested polyarthralgia and polyarthritis leading to progressive deformity of the joints of hands and feet (without loss of cartilage or erosion of bone); persistent urticaria made worse by cold and accompanied by hypocomplementemia; and progressive cardiac valvular disease with mitral and aortic stenosis and regurgitation. In 1996, she developed subglottic tracheal stenosis that resolved by the end of 1997 without a change in treatment, which has consisted of low dose azathioprine, glucocorticoid, and nonsteroidal antiinflammatory drugs. Tests for cryoprecipitable protein, antineutrophil cytoplasmic antibodies, antinuclear antibody, and rheumatoid factor were negative. Skin biopsy was consistent with "leukocytoclastic vasculitis." The pathogenesis of this remarkable combination of syndromes is unknown.

Anti-Inflammatory Agents↗