Biomedical subjects

C-Y Hsu

Publications and source records attributed to C-Y Hsu.

10 recordsLinked to original sources

PubMed2007

Vertebral osteonecrosis: MR imaging findings and related changes on adjacent levels.

BACKGROUND AND PURPOSE: No prior report has comprehensively discussed the intravertebral vacuum cleft sign and the fluid sign on MR images of vertebral osteonecrosis. The purpose of this study was to investigate MR images of osteonecrotic vertebral bodies and adjacent intervertebral disks and vertebral bodies. METHODS: We retrospectively reviewed MR images of patients with vertebral osteonecrosis. Affected vertebral bodies with osteonecrosis were defined as an avascular area (nonenhanced area on enhanced T1-weighted images) with collections of intravertebral fluid (hyperintense signal on T2-weighted images), air (signal void on all images), or both. The degree of vertebral collapse was classified as mild (>50%) or severe (<50%) preserved vertebral height. Changes in adjacent intervertebral disks or vertebral bodies 2 above and 2 below the affected vertebrae were compared. RESULTS: We enrolled 112 patients (30 men, 82 women; 121 vertebral bodies) in our study. Intravertebral air alone was observed in 48 involved levels (39.7%), intravertebral fluid alone was found in 47 (38.8%), and both coexisted in 26 (21.5%). Degree of vertebral collapse in affected vertebral bodies significantly differed with presence of air or fluid (P < .05). Vertebral compression fractures adjacent to the affected vertebral bodies were more common in those with intravertebral air alone than in those with intravertebral fluid alone (P < .05). CONCLUSION: Vertebral collapse was more advanced and adjacent vertebral compression fractures were more frequent in patients with intravertebral air than in those with intravertebral fluid.

Aged↗

PubMed2006

Transrectal ultrasound in the staging of clinical T3a prostate cancer.

INTRODUCTION: The clinical staging of T3a prostate cancer is usually based on digital rectal examination (DRE). Overstaging of clinical T3a prostate cancer is present in 13-27% of the cases presented and understaging is in the range of 30%. The value of transrectal ultrasound (TRUS) as a staging tool is not generally accepted. The purpose of this study is to determine whether TRUS can refine the local staging in unilateral clinical T3a (cT3a) prostate cancer. PATIENTS AND METHODS: Between 1987 and 2004, 200 patients were staged as unilateral cT3a prostate cancer by DRE. All patients underwent radical prostatectomy and bilateral pelvic lymphadenectomy. Preoperative TRUS staging was performed for all patients. Final histopathological staging was compared with DRE and TRUS staging. The operable group (OG) was defined as T2 to unilateral T3a, and the advanced group (AG) was defined as bilateral T3a to T4. RESULTS: All DRE patients were assumed operable. However, in this group histopathology showed 27.0% of the patients had advanced disease. TRUS confirmed 184 patients to be operable (140 having unilateral cT3a, 44 patients having cT1c to cT2). Sixteen patients were considered to have advanced disease by TRUS. Importantly, in this group, 68.7% of the cases were indeed confirmed to have advanced disease by histopathology. CONCLUSION: TRUS can be used to refine clinical staging in unilateral cT3a prostate cancer. In cases where TRUS indicates advanced disease, it might be wise to trust the TRUS staging, rather than the DRE.

Adult↗

PubMed2006

Hypokalemic paralysis due to Gitelman syndrome: a family study.

Hypokalemic paralysis is rarely seen as the presenting feature in patients with Gitelman syndrome. We report a Chinese man who presented with periodic paralysis, in whom molecular analysis revealed compound heterozygous inheritance of three mutations of the thiazide-sensitive sodium chloride cotransporter. Family history revealed intrafamilial variation in phenotypes. Gitelman syndrome should be considered as a cause of hypokalemic paralysis, and molecular analysis may help establish the diagnosis.

Adult↗

PubMed2006

Sleep-disordered breathing after stroke: a randomised controlled trial of continuous positive airway pressure.

BACKGROUND: Sleep-disordered breathing (SDB) is common after stroke, but it is unclear whether it should be treated. OBJECTIVE: To conduct a randomised controlled trial of continuous positive airway pressure (CPAP) after stroke. METHODS: Patients with stroke with > or = 30 apnoeas and hypopnoeas per hour ((A+H)/h) with predominant obstructive sleep apnoea or hypopnoea were randomised to either CPAP treatment or conservative treatment for 8 weeks. Outcomes were measured blind to treatment allocation at 8 weeks and 6 months after the stroke. The primary outcome was physical function on the Nottingham Extended Activities of Daily Living Scale. RESULTS: Of 658 patients with stroke screened, only 71 (10.7%) were eligible and consented to a sleep study 14-19 days after stroke. 66 patients completed the sleep study (21 women; mean age 72 years), 33 (50%) had > or = 30 (A+H)/h that were predominantly obstructive. 15 were randomised to CPAP treatment and 15 to conventional treatment. Despite intensive efforts, objective use of CPAP was poor, averaging 1.4 h a night. CPAP treatment resulted in no significant improvements (p>0.1) in the primary outcome or in neurological function or sleepiness, and in poorer health status on some measures. CONCLUSIONS: This trial showed no benefit from CPAP treatment, the relevance of the observed detrimental effects is questionable. Even in our highly selected patients with stroke, use of CPAP was poor. At present, CPAP treatment should be advocated for patients with stroke only if they have symptoms of SDB.

Activities of Daily Living↗

PubMed2006

Physiological changes during hemodialysis in patients with intradialysis hypertension.

Intradialysis hypertension is a frustrating complication among hemodialysis (HD) patients. This study was conducted to investigate the physiological changes during intradialytic hypertension. The beat-to-beat continuous heart rate, hematocrit (Hct) changes during HD, serum levels of nitric oxide, plasma levels of catecholamine, renin, endothelin (ET-1), cardiac output (CO), and peripheral vascular resistance (PVR) were measured before and after HD in patients prone to develop intradialysis hypertension (n = 30) and from age, sex-matched control HD subjects (n = 30). It was found that the baseline values of Hct, serum levels of nitric oxide, plasma levels of catecholamine, renin, and ET-1, CO, PVR, and power index (low frequency/high frequency ratios) of heart rate variability were not significantly different between the patients and control subjects. In the hypertension-prone group, the plasma levels of catecholamine, renin, and the serial measurements of power index, did not show significant changes. However, the patients showed a significant elevation of systemic vascular resistance (56.8 +/- 9.2% vs 17.7 +/- 9.5; P < 0.05), ET-1 (510.9 +/- 43.3 vs 276.7 +/- 30.1 pg/ml; P < 0.05) and a significant decrease of nitric oxide (NO)/ET-1 balance (0.018 +/- 0.003 vs 0.034 +/- 0.005; P < 0.05) at the end of HD compared with the control patients. It was found that the physiological changes in intradialysis hypertension patients were characterized by inappropriately increased PVR through mechanisms that did not involve sympathetic stimulation or renin activation but might be related with altered NO/ET-1 balance.

Autonomic Nervous System↗

PubMed2006

Laser-fluoride effect on root demineralization.

Although the individual cariostatic effects of laser and fluoride have been shown, the combined effect of CO(2) laser and fluoride on root demineralization remains uncertain and was the main aim of this study. By using a pH-cycling system and Polarized Light Microscopy, we demonstrated the synergistic effect of fluoride combined with CO(2) laser treatment on reducing root demineralization. The mean lesion depths (in microm) for each group were 160 +/- 14 (Control), 113 +/- 8 (Laser treatment alone), 111 +/- 6 (Fluoride treatment alone), and 25 +/- 7 (Fluoride followed by laser treatment). A significant laser-enhanced fluoride uptake, characterized by the ToF-SIMS analysis, was revealed by the 37% and 400% increments in loosely and firmly bound fluorides (both p < 0.002) in laser-irradiated areas, compared with the non-irradiated controls. In conclusion, there is a significant synergistic effect of combined CO(2) laser and fluoride treatment on the inhibition of root demineralization, possibly due to laser-enhanced fluoride uptake in the root.

Carbon Dioxide↗

PubMed2004

A computer program to calculate the size of tympanic membrane perforations.

Chronic suppurative otitis media is characterized by the presence of a persistent perforation of the tympanic membrane. Accurate estimation of the perforation size is helpful in clinical management and research. In this study, a computer program was developed to calculate the percentage of a perforation relative to the whole tympanic membrane including the pars tensa and pars flaccida. In order to demonstrate the variability of estimations of perforation size by different surgeons, we calculated the percentage of perforation for four tympanic membranes, and compared the results with those estimated by five experienced otologists and 10 senior residents. The results show that the estimations from both otologists and residents departed from the values calculated by the computer program quite substantially. Beside, the variance of the estimation is large. However, the variances of computer calculation are quite small, which means that the results obtain from different users are quite consistent. Therefore, we concluded that this program is necessary and useful to evaluate the size of the perforation as the differences in visual estimations can be very big and the variances can be large for different individuals, even by experienced otologists.

Chronic Disease↗

PubMed2003

Outpatient weekly neoadjuvant chemotherapy followed by radiotherapy for advanced nasopharyngeal carcinoma: high complete response and low toxicity rates.

Nasopharyngeal carcinoma (NPC) is a radiosensitive and chemosensitive tumour. The aim of this prospective study is to evaluate the toxicity and efficacy of an outpatient weekly neoadjuvant chemotherapy (NeoCT) plus radiotherapy for advanced NPC. From November 1998 to August 2001, 90 NPC patients meeting the following criteria were treated: (1) neck node >6 cm; (2) supraclavicular node metastasis; (3) skull base destruction/intracranial invasion plus multiple nodes metastasis; (4) multiple neck nodes metastasis with one of nodal size >4 cm; or (5) elevated serum LDH level. The NeoCT consists of cisplatin 60 mg m(-2), alternating with 5-fluorouracil 2500 mg m(-2) plus leucovorin 250 mg m(-2) (P-FL) by an outpatient weekly schedule for a total of 10 weeks. Local radiotherapy > or =70 Gy by conventional fractionation was delivered within 1 week after NeoCT. Patient compliance was rather good. Grade 3-4 toxicity of NeoCT included leucopaenia (7.8%), anaemia (18.9%), thrombocytopaenia (3.3%), nausea/vomiting (4.4%), and weight loss (1.1%). Response evaluated after NeoCT showed 73.3% complete response (CR) rate of primary tumour, 71.1% CR rate of neck nodes, and an overall CR rate of 57.8%. In all, 88 out of 90 patients received rebiopsy of primary tumour and 55 patients (62.5%) revealed pathological CR. After a median follow-up time of 24 months, one persistent disease and 18 relapses were noted. The 2-year nasopharynx disease-free, neck disease-free, distant disease-free, overall, and progression-free survival rates are 98.9, 95.9, 80.0, 92.1, and 77.5%, respectively. Preliminary data of the current study show that P-FL NeoCT plus radiotherapy is a low-toxic regimen with promising results on very advanced NPC patients and merits to be investigated in phase III trials.

Adenocarcinoma↗

PubMed2002

Ultrasonography is superior to plain radiography in the diagnosis of pneumoperitoneum.

BACKGROUND: The aim of this study was to compare plain radiography with abdominal ultrasonography in the detection of pneumoperitoneum. METHODS: A total of 188 patients with suspected hollow organ perforation were studied. All patients had abdominal ultrasonography, upright chest radiography and left lateral decubitus abdominal radiography examinations. The sensitivity, specificity, positive and negative predictive value, and accuracy of chest and abdominal radiography were compared with that of abdominal ultrasonography. RESULTS: One hundred and seventy-eight patients underwent laparotomy; 170 patients had hollow organ perforation, five patients had perforated appendicitis and three had acute cholecystitis. In the diagnosis of pneumoperitoneum, ultrasonography had improved sensitivity (92 versus 78 per cent), negative predictive value (39 versus 20 per cent) and accuracy (88 versus 76 per cent), and similar specificity (both 53 per cent) and positive predictive value (95 versus 94 per cent) compared with plain radiography. CONCLUSION: Ultrasonography is more sensitive than plain radiography in the diagnosis of pneumoperitoneum.

Adolescent↗

PubMed2002

Tophaceous gout of the spine: MR imaging features.

AIM: To define the magnetic resonance (MR) imaging features of tophaceous gout of the spine. MATERIALS AND METHODS: We present the MR imaging examinations of 4 patients with spinal tophaceous gout. Spin-echo T1-weighted and fast spin-echo T2-weighted images were obtained for all patients, and 2 patients had gadolinium-enhanced MR imaging studies. Corresponding computed tomography (CT) was performed in one patient. All images were evaluated for the characteristics of the gouty tophi. RESULTS: The gouty tophi were located at the lower thoracic (n=1) and lumbar (n=3) levels. All tophi yielded homogeneous intermediate to low signal on T1-weighted images and variable signal intensity on T2-weighted images, comprising small foci of very low signal intensity on all sequences. Gadolinium-enhanced MR imaging studies revealed homogeneous enhancement or heterogeneous peripheral enhancement. Diffuse stippled calcifications were found in the tophi on CT images. Periarticular tophi with juxtaarticular bony erosions around facet joints occurred in 3 patients. CONCLUSION: Spinal tophaceous gout should be considered in the differential diagnosis when periarticular deposits contain very low signal foci on all MR imaging sequences.

Adult↗