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Biomedical subjects

H-H Chen

Publications and source records attributed to H-H Chen.

10 recordsLinked to original sources
PubMed2006

Spontaneous spinal epidural hematoma in a 4-month-old infant.

STUDY DESIGN: A case report and a review of literature. OBJECTIVES: To present the first youngest infant of a 4-month-old boy with spontaneous spinal epidural hematoma in cervicothoracic spine. SETTING: National Cheng Kung University Hospital, Tainan, Taiwan. METHODS: A 4-month-old boy who initially presented with irritable crying, neck stiffness, and fever followed by progressive quadriparesis. Magnetic resonance imaging (MRI) of the spine disclosed a space-occupying lesion on the right posterior-lateral aspect of the cervicothoracic spinal canal. Laminectomy with reconstruction in situ from C4 to T4 was performed 5 days after the onset of symptoms. RESULTS: The boy had gradual improvement of his neurological status. Follow-up visit 1 year later, the infant's growth and development was within normal limit without any neurological deficits; his repeat MRI showed complete fusion of each implanted lamina and well expansion of the spinal cord. CONCLUSIONS: Prompt surgical decompression is valuable, irrespective of the time interval between symptom onset and operation in infant.

Cervical Vertebrae↗
PubMed2006

Ketamine, but not propofol, anaesthesia is regulated by metabotropic glutamate 5 receptors.

BACKGROUND: Group I metabotropic glutamate receptors (mGluRs) have been reported to regulate N-methyl-d-aspartate (NMDA) receptor function in various brain regions. The selective mGluR5 antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) can potentiate NMDA antagonists such as PCP and MK-801-induced behavioural responses. In the present study, the role of group I mGluRs on ketamine- and propofol-induced general anaesthesia was examined. METHODS: Mice were pretreated with various doses of the group I mGluR agonist (S)-3,5-dihydroxyphenylglycine (DHPG), selective mGluR5 agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG), mGluR1 antagonist 7-(hydroxyimino)cyclopropa[b]chromen-1a-carboxylate ethyl ester (CPCCOEt) and mGluR5 antagonist MPEP followed by administration of ketamine (120 mg kg(-1)) or propofol (140 mg kg(-1)) to induce anaesthesia. The duration of loss of righting reflex was recorded. RESULTS: DHPG and CHPG antagonized and MPEP potentiated ketamine-induced anaesthesia in a dose-dependent manner. CPCCOEt was ineffective. However, propofol-induced anaesthesia was not affected after manipulating mGluR1 and mGluR5 receptors. CONCLUSIONS: mGluR5 receptors play an important role in modulation of anaesthesia induced by ketamine, but not propofol.

Anesthetics, Dissociative↗
PubMed2005

Learning the pedalo locomotion task.

The authors examined the learning function of a multiple biomechanical degrees of freedom coordination task. Four adult participants practiced the pedalo locomotion task for 350 trials over 7 days. On the basis of the Cauchy theorem, the authors applied a movement pattern difference score that provides a measure of convergence to a fixed point as the criterion for quantifying learning. The findings showed a significant reduction of the movement pattern difference score over practice. Neither an exponential (0.11) nor a power law (0.10) function accommodated a large percentage of the variance of the pattern difference measure on individual learning functions, but the respective fits were higher, although not different, for movement time (.57, .55). Principal components analysis showed a decrease of components over practice; the analysis also showed that 3-5 components were required to accommodate 90% of the variance of the whole-body motion at the end of the final practice session. Those findings on the learning functions for movement and outcome scores are discussed in relation to the redundancy of the biomechanical system in moving to a dynamical stable fixed point in this task.

Adult↗
PubMed2004

Successive development of cutaneous polyarteritis nodosa, leucocytoclastic vasculitis and Sweet's syndrome in a patient with cervical lymphadenitis caused by Mycobacterium fortuitum.

Mycobacterium fortuitum is a rapidly growing mycobacterium found in soil and water throughout the world. It can cause diseases in immunocompetent patients, usually resulting in localized skin and soft tissue infections. Cervical lymphadenitis caused by M. fortuitum is rare. We report a 46-year-old woman in whom skin lesions of cutaneous polyarteritis nodosa, leucocytoclastic vasculitis and Sweet's syndrome had successively developed before the diagnosis of cervical lymphadenitis caused by M. fortuitum was made. The skin lesions responded to colchicine and systemic corticosteroids but recurred intermittently. After establishment of the diagnosis, she received treatment with clarithromycin and ciprofloxacin. The cervical lymph nodes decreased in size 6 months later and no more new skin lesions were found.

Female↗
PubMed2003

Quantifying the potential problem of overdiagnosis of ductal carcinoma in situ in breast cancer screening.

The relevance of detection of ductal carcinoma in situ (DCIS) in a breast cancer screening programme, and the extent of overdiagnosis of non-progressive lesions, remains controversial. It was the purpose of this paper to estimate the incidence of non-progressive, 'overdiagnosed' DCIS. We defined non-progressive DCIS (DCIS(0)) as DCIS which could not have progressed to invasive disease if left untreated. Progressive DCIS (DCIS(1)) was defined as DCIS which has the propensity to progress to invasive disease. We fitted a Markov process model of the incidence of progressive and non-progressive DCIS, the transition of the former to preclinical invasive disease and the subsequent progression to clinical symptomatic cancer. We used data from the Swedish Two-County Trial and from service screening programmes in the UK, Netherlands, Australia and the USA to estimate the incidence of progressive and non-progressive DCIS, and the detection rates of each at the first and subsequent screening. Average incidence of non-progressive DCIS was 1.11 per 100000 per year. Average incidence of progressive DCIS was 2.1 per 1000 per year. At prevalence screen, 37% of DCIS cases were estimated to be non-progressive. A woman attending prevalence screen has a 19 times greater chance of having a progressive DCIS or an invasive tumour diagnosed than of having a non-progressive DCIS diagnosed. At incidence screen, only 4% of DCIS cases were estimated to be non-progressive. A woman attending an incidence screen has a 166 times higher probability of having a progressive DCIS or invasive lesion diagnosed than of having a non-progressive DCIS diagnosed. There is an element of overdiagnosis of DCIS in breast cancer screening, but the phenomenon is small in both relative and absolute terms.

Adult↗
PubMed2003

TGF-beta1 suppresses apoptosis via differential regulation of MAP kinases and ceramide production.

Serum deprivation induces apoptosis in NIH3T3 cells, which is associated with increased intracellular ceramide generation and with the activation of p38 mitogen-activated protein (MAP) kinase. Treatment of cells with transforming growth factor-beta1 (TGF-beta1) activated the extracellular signal regulated kinases 1 and 2 (ERK1/ERK2), inhibited the serum deprivation-induced p38 activation and the increase in intracellular ceramide formation, leading to the stimulation of cell proliferation and the suppression of apoptosis. Inhibition of p38 MAP kinase by SB203580 significantly reduced the serum-deprivation-induced apoptosis. Overexpression of p38 increased the cell apoptosis and reduced the antiapoptotic effect of TGF-beta1. Inhibition of ERK1/ERK2 by PD98059 completely inhibited the TGF-beta1-stimulated proliferation and partially inhibited the antiapoptotic effects of TGF-beta1. Neither SB203580 nor PD98059 has obvious effect on TGF-beta1-mediated inhibition of the increased ceramide generation. Serum-deprivation-induced apoptosis in NIH3T3 cells can also be blocked by broad-spectrum caspase inhibitor. TGF-beta1 treatment has an inhibitory effect on caspase activities. Our results indicate that ceramide, p38, and ERK1/ERK2 play critical but differential roles in cell proliferation and stress-induced apoptosis. TGF-beta1 suppresses the serum-deprivation-induced apoptosis via its distinct effects on complex signaling events involving the activation of ERK1/ERK2 and the inhibition of p38 activation and increased ceramide generation.

3T3 Cells↗
PubMed2002

Hydroa vacciniforme-like primary cutaneous CD8-positive T-cell lymphoma.

An 8-year-old Taiwanese girl had a 6-month history of a relapsing papulovesicular eruption on her face that resembled hydroa vacciniforme (HV). Histologically, there was a dense infiltration of large atypical lymphocytic cells expressing CD8. TCR-gamma gene rearrangement study revealed a monoclonal band present in the DNA extracted from the specimen. A diagnosis of CD8+ cutaneous T-cell lymphoma (CTCL) was made. The patient was treated with Chinese herbal drugs and her skin lesions waxed and waned. At this writing, 11 months after establishment of the diagnosis, the skin lesions have been limited to the facial area and no definite evidence of systemic involvement is noted. To our knowledge, this is the first case of CD8+ primary CTCL with clinical features resembling HV.

CD8-Positive T-Lymphocytes↗
PubMed2002

All-cause mortality among breast cancer patients in a screening trial: support for breast cancer mortality as an end point.

BACKGROUND: It has recently been suggested that all-cause mortality is a more appropriate end point than disease specific mortality in cancer screening trials, and that disease specific mortality is biased in favour of screening. This suggestion is based partly on supposed inconsistencies between all-cause mortality results and disease specific results in cancer screening trials, and alleged increases in deaths from causes other than breast cancer among breast cancer cases diagnosed among women invited to screening. METHODS: We used data from the Swedish Two-County Trial of mammographic screening for breast cancer, in which 77 080 women were randomised to an invitation to screening and 55 985 to no invitation. We estimated relative risks (RRs) (invited v control) of death from breast cancer, death from other causes within the breast cancer cases, and death from all causes within the breast cancer cases. RRs were adjusted for age and took account of the longer follow up of breast cancer cases in the invited group due to lead time. RESULTS: There was a significant 31% reduction in breast cancer mortality in the invited group (RR 0.69, 95% confidence interval (CI) 0.58-0.80; p<0.001). There was no significant increase in deaths from other causes among breast cancer cases in the invited group (RR 1.12, 95% CI 0.96-1.31; p=0.14). A significant 19% reduction in deaths from all causes was observed among breast cancer cases in the group invited to screening (RR 0.81, 95% CI 0.72-0.90; p<0.001). A more conservative estimation gave a significant 13% reduction (RR 0.87, 95% CI 0.78-0.97; p=0.01). These findings are consistent with the magnitude of the reduction in breast cancer mortality. CONCLUSIONS: Invitation to screening was associated with a reduction in deaths from all causes among breast cancer cases, consistent with high participation rates in screening. There is no significant evidence of bias in cause of death classification in the Two-County Trial, and as breast cancer mortality is the targeted clinical outcome in breast cancer screening, it is the appropriate end point in a breast cancer screening trial. All-cause mortality is a poor and inefficient surrogate for breast cancer mortality.

Adult↗
PubMedDate not supplied

Extrauterine müllerian adenosarcoma associated with endometriosis and rectal villotubular adenoma: report of a case and review of the literature.

Extrauterine mullerian adenosarcoma is rare and is thought to arise from endometriotic deposits or pluripotent mesothelial and mesenchymal cells of the pelvic cavity. Concomitant colon-rectal neoplasm was reported but the relationship between extrauterine adenosarcoma and colon tumor was not studied. We describe an extrauterine adenosarcoma with a concomitant rectal tubulovillous adenoma. The patient had a long-term history of endometriosis and unopposed estrogen therapy. Immunohistochemical study was performed to investigate the origin and nature of the adenosarcoma. Immunostaining provided the evidence to distinguish between rectal tumor and adenosarcoma. Extrauterine adenosarcoma may arise from endometriosis, and hormone replacement therapy may have some role in the malignant transformation process. Adenosarcoma should be considered in the differential diagnosis of a new pelvic tumor in a patient with a history of endometriosis.

Adenoma↗