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Biomedical subjects

C Y Yang

Publications and source records attributed to C Y Yang.

At least 163 records · Page 9Linked to original sources
PubMed1996

Two-stage cementless revision THR after infection. 5 recurrences in 40 cases followed 2.5-7 years.

We revised 40 infected hip prostheses in 40 patients as a two-stage procedure, including intravenous and oral antibiotics, gentamicin beads, and delayed cementless implantation of porous-coated THR. The duration of antibiotic treatment was 8 weeks. The interval from resection to reimplantation was, on average, 48 (8-108) weeks. 39 patients were followed, on average, 4 (2.5-7) years. 5 patients had a recurrent infection. In patients who did not have a recurrent infection, the Harris hip score exceeded 80 in 32 patients. Radiographically, femoral component migration of 2-6 mm was noted in 3 cases. The recurrent infection rate, and the functional and radiographic results are comparable with those obtained using a two-stage procedure with antibiotic cement.

Adult↗
PubMed1996

Late-onset idiopathic hypoparathyroidism with thymoma: a case report.

A 62-year-old male was admitted because of numbness and twitching of both hands. Hypocalcemia with positive Trousseau's sign was noted. Chest X-ray and computed tomography (CT) showed an anterior mediastinal mass. Skull X-ray and whole body bone scan could not rule out bony metastasis to the left parietal bone, causing an anterior mediastinal tumor with bony metastasis to be suspected initially. Median sternotomy and extended thymectomy were done, and Stage II thymoma with negative calcitonin staining was noted. However, hypocalcemia persisted after thymectomy and the results of pre-operative and post-operative intact-parathyroid hormone (intact-PTH) were less than the detection limit (<13.3 pg/ml). Tumor markers and gallium tumor scan were all negative. Brain CT disclosed calcification over the bilateral basal ganglia and bilateral dentate nuclei of the cerebellum; the supposed metastatic osteolytic lesions of parietal bone were considered to result from pacchionion arachnoid granulation tissues. The coexistence of late-onset idiopathic hypoparathyroidism and thymoma has not been reported before. Long-term replacement therapy with vitamin D and calcium was necessary for this case.

Humans↗
PubMed1996

Cementless reimplantation of hydroxyapatite-coated total hips after periprosthetic infections.

From February 1991 to July 1993, 26 hydroxyapatite (HA) coated total hips were implanted in 26 patients with infected hip prostheses. Seven were done as one-stage exchange arthroplasties and the other 19 were delayed reimplantations. Successful reimplantation was defined as a functioning hip without recurrence of infection at least 2 years after reimplantation. During a follow-up period of 25 to 54 months, 24 of the reimplantations were successful. Our success rate using the HA-coated prosthesis is similar to previous reports that used antibiotic impregnated bone cement. The HA method avoids the complications encountered with bone cement.

Adult↗
PubMed1996

Glutamate immunoreactivity in the tiger salamander retina differentiates between GABA-immunoreactive and glycine-immunoreactive amacrine cells.

A higher proportion of retinal amacrine cells, largely thought to be inhibitory, in tiger salamander retina are immunoreactive (+) for the excitatory amino acid glutamate than for either of the inhibitory amino acids, GABA and glycine. The colocalizations of glutamate immunoreactivity, GABA immunoreactivity and glycine immunoreactivity were studied in the proximal retina of tiger salamander using postembedding immunocytochemical methods in consecutive semithin sections. A considerable degree of colocalization was observed between glutamate immunoreactivity and GABA immunoreactivity and to a lesser extent with glycine immunoreactivity. No glutamate-immunoreactive cells were single labelled in INL3 (proximal inner nuclear), 12% were single labelled in INL2 (mid INL; these are bipolar cells), 62% were singled labelled in the ganglion cell layer (GCL) and likely to be ganglion cells. Single-labelled glycine-immunoreactive cells comprised 16% in INL3, 2%; INL2 and GCL, 0%). Glutamate immunoreactivity co-localized four times as often with GABA immunoreactivity than glycine immunoreactivity in INL3 (77% versus 19%), comparably in INL2 (37% and 32%) and six times as often in the GCL (29% versus 5%). A computerized image analysis of the relative intensities of glutamate immunoreactivity in GABA-immunoreactive/glutamate-immunoreactive and glycine-immunoreactive/glutamate-immunoreactive double labelled amacrine cells in INL3 revealed that all glycine-immunoreactive cells contained low intensities of glutamate immunoreactivity; whereas 35% of GABA-positive cells had medium to high intensities of glutamate immunoreactivity. There was a significant correlation (r = 0.44; p < 0.01) between the intensities of glutamate immunoreactivity and GABA immunoreactivity in GABA-immunoreactive/glutamate-immunoreactive amacrine cells. The common colocalization of glutamate immunoreactivity with GABA immunoreactivity and the positive correlation of their relative intensities suggests that glutamate is likely to serve as a precursor for GABA synthesis. However, intense glutamate immunoreactivity in 5% of the amacrine cells suggests a transmitter function. Glycine-immunoreactive amacrine cells contained little or no glutamate immunoreactivity, suggesting a minimal role for glutamate as a neurotransmitter in these cells. The major distribution of intense glutamate immunoreactivity is in bipolar cells and ganglion cells, consistent with data suggesting that glutamate is the transmitter in the retinal through pathway.

Animals↗
PubMed1996

Erratic passage and anchorage of a right subclavian catheter caused by preoccupancy of an indwelling right jugular venous catheter--a case report.

We report a case of central venous catheter (CVC) malposition. Through subclavian approach the CVC tip was intended to anchor in the superior cava, but it turned out to be in the right internal jugular vein as revealed by chest X-ray. The cause of malposition was perhaps the preoccupancy of the jugular venous CVC which interferred with a normal advancement. Although the malposition of the catheter might not produce any immediate problem, later complication might occur. Thus, removal of a problematic catheter and recatheterization was indicated.

Aged↗
PubMed1995

Changes in phases and crystallinity of plasma-sprayed hydroxyapatite coatings under heat treatment: a quantitative study.

With three kinds of plasma-sprayed hydroxyapatite coatings (HACs) prepared, the objectives of this study were (1) to establish the calibration methods for quantitatively measuring the concentration of impurity phases and the degree of crystallinity of the HACs, and (2) to explore the effects of postheat treatments at various temperatures in vacuo on the changes of phases and crystallinity of the HACs. By the internal standard method used, the concentrations of impurity phases, such as alpha-TCP, beta-TCP, and TP, of the assprayed HACs were significantly higher than those measured by the direct intensity-ratio method, and the CaO phase was lower than the direct intensity-ratio method. When the HACs were heat treated in the temperature interval 630-850 degrees C, the concentrations of impurity phases obviously decreased, and the coating crystallinity apparently increased. After annealing at 850 degrees C, an HAC consisting of at least 95% crystallinity with few impurity phases was obtained. As the annealing temperatures in the interval 850-1000 degrees C were applied, however, the HA phase seriously decomposed, resulting in the appearance of a large number (higher than 20 wt%) of impurity phases in the HACs. This work suggests that the optimum heat treatment conditions in vacuo for maximizing crystallinity and minimizing impurity phases of the HACs do not occur at the same temperature.

Alloys↗
PubMed1995

A double-blind comparison of once-daily metoprolol controlled-release and atenolol in the treatment of Chinese patients with mild to moderate hypertension.

The efficacy and tolerability of controlled-release metoprolol (metoprolol CR/ZOK), 100-200 mg, and atenolol, 50-100 mg, once daily was compared in Chinese patients with mild to moderate essential hypertension. The study was of a randomized, double-blind, two-way crossover design. The active treatment periods lasted 4 weeks each and were preceded by a 4-week placebo run-in period. The two double-blind phases were separated by a 2-week washout period on placebo. Blood pressures and heart rates were measured at rest in each 2-week visit and during exercise at the end of each treatment period. Twenty-four patients (M/F = 14/10) were valid for efficacy analysis. Their ages ranged from 39 to 68, with a mean of 53.5 years. The rest supine blood pressure and heart rate before active treatment was 160 +/- 15/106 +/- 6 mmHg and 75 +/- 14 beats/min (mean +/- SD), respectively. A responder was defined as exhibiting a supine diastolic blood pressure < or = 90 mmHg or a supine diastolic blood pressure reduction of at least 10% of the baseline level. Both agents had high response rate: 88% and 92% of all patients responded to metoprolol CR/ZOK and atenolol, respectively. Both active treatments considerably reduced resting systolic and diastolic blood pressures and heart rates as compared with baseline (p < 0.001), respectively. With controlled-release metoprolol, a more pronounced beta 1 blockade was obtained than with atenolol, which was expressed as a significant reduction in exercise-induced heart rate at the highest comparable workload compared with placebo (p < 0.05). These findings are compatible with those reported from western populations.

Administration, Oral↗
PubMed1995

ELISA quantitation of apolipoproteins in plasma lipoprotein fractions: ApoE in ApoB-containing lipoproteins (Lp B:E) and ApoB in ApoE-containing lipoproteins (Lp E:B).

Growing clinical evidence suggests that metabolic behavior and atherogenic potential vary within lipoprotein subclasses that can be defined by apolipoprotein variation. Variant constituency of apolipoproteins B and E (apoB and apoE) may be particularly important because of the central roles of these apolipoproteins in the endogenous lipid delivery cascade. ApoB is the sole protein of low-density lipoprotein (LDL), and like LDL cholesterol, the plasma apoB level has been positively correlated with risk for atherosclerotic disease. ApoE is a major functional lipoprotein in the triglyceride-rich lipoproteins, and may be crucial in the conversion of very low density lipoprotein (VLDL) to LDL. Based on work by others that enabled the quantititation of apoB-containing particles by content of up to two other types of apolipoprotein, we have developed a method for determining the amount of apoE in apoB-containing lipoproteins (Lp B:E) and the amount of apoB in apoE-containing lipoproteins (Lp E:B). From the Lp B:E and Lp E:B concentrations, the molar ratio of apoE to apoB in lipoproteins containing apoB and/or apoE in plasma can be determined. The methodology is fast, specific, and sensitive and should prove extremely useful in further categorizing lipoproteins and characterizing their behavior. In applying this method to clinical groupings of normo- and hyperlipidemia, we found that the plasma triglyceride level correlated with the apoE and Lp B:E concentrations in plasma, while the total cholesterol level correlated with the apoB and Lp E:B levels.

Antibody Specificity↗
PubMed1995

Application of anticancer agent embolism in Miles' operation.

Presented in this paper is a report of the prospective studies on rectal cancer. By using the method of anticancer agent gelatin sponge to form embolism and by ligating the bilateral arteria iliaca internal, we performed Miles' operation on 64 cases of rectal cancer. Only 24 cases in the control group had Miles' operation. The amount of blood transfused during operation, duration of operation, days of hospitalization, infection rate of incision on the peritoneum, and relapse rate in treated group were significantly different from those in the control group (P < 0.05).

Adult↗
PubMed1995

Upright postures and isoproterenol infusion for provocation of neurocardiogenic syncope: a comparison of standing and head-up tilting.

Head-up tilt testing has proved to be useful in provocation of neurocardiogenic syncope. The purpose of this study was to examine whether simply assuming an upright posture by standing can be an alternative to the head-up tilt testing for diagnosis of neurocardiogenic syncope. Eighty-four patients with recurrent unexplained syncope and 22 normal volunteers were recruited into the study. Forty-seven patients with syncope and all normal volunteers received the standing test. Thirty-seven of the patients with syncope received head-up tilt testing (90 degrees). All subjects lay down for 5 minutes and then assumed an upright posture until syncope or presyncope occurred or until a maximum of 10 minutes was reached in each stage of the test. The tests included four stages: baseline and infusion of 1, 2, or 3 micrograms/min isoproterenol in each of the successive stages. Five subjects could not tolerate the procedure, and further testing was terminated. Overall, the standing test was positive in 83% of the patients with syncope, and its specificity was 74%. The head-up tilt testing was positive in 75% of the patients with syncope. The duration of assuming an upright posture before occurrence of syncope or presyncope was significantly longer in the syncope-tilting group in the third stage (p < 0.01) and the fourth stage (p < 0.05) compared with the syncope-standing group. However, the curves of the time course for cumulative positive rates were not significantly different (p = 0.0739) in the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Electropharmacological actions of propofol on calcium current in guinea-pig ventricular myocytes.

Propofol, a widely-used intravenous anesthetic, causes bradycardia, depression in contractility and hypotension. The cellular mechanisms responsible for these cardiac toxicity remain unclear. In this study, we examined the cellular electropharmacological actions of propofol on calcium current in guinea-pig heart. Single ventricular myocytes were freshly isolated from guinea-pig using modified enzymatic method. Whole-cell voltage-clamp technique was applied with one suction pipette. Transmembrane L-type calcium current (ICa(L)) was separated from other ionic currents by voltage-control, ionic channel blockers and ion substitution methods. Our results show that propofol decreased ICa(L) in a concentration-dependent manner (KD = 54.2 microM). Slope conductance of current-voltage relation was decreased by 56 microM propofol. Propofol did not affect the steady-state activation curve, but shifted the inactivation curve to hyperpolarizing direction. Recovery from inactivation was slowed down by propofol. Marked resting block and use-dependent block were noted. In conclusion, our results indicate that propofol inhibits cardiac L-type calcium current mainly by shifting inactivation curve and retarding the recovery from inactivation.

Anesthetics, Intravenous↗
PubMed1995

MELAS syndrome associated with diabetes mellitus and hyperthyroidism: a case report from Taiwan.

MELAS syndrome is a form of mitochondrial myopathy with manifestations of seizure, stroke-like syndrome, lactic acidosis, ragged red muscle fibres and mitochondrial encephalopathy. The syndrome has been reported in association with a variety of endocrine and metabolic disorders including diabetes mellitus (DM), hypothalamo-pituitary hypofunction, hypothalamic growth hormone deficiency and delayed puberty. Mitochondrial DNA (mtDNA) point mutation may be the major pathological defect. However, association of MELAS syndrome with hyperthyroidism has not previously been reported. A case is reported from Taiwan of a 32-year-old woman suffering from MELAS syndrome with associated DM and hyperthyroidism. When the latter was diagnosed in April 1988, the patient underwent subtotal thyroidectomy. There was no family history of thyroid disease. Because of repeated seizures, she had computed tomography (CT) and magnetic resonance imaging (MRI) of the brain which showed focal, low-density lesions over the cerebral hemispheres. Both serum and cerebral spinal fluid lactic acid levels were elevated. Mild elevations of serum T4 and T3 and a high titre of TSH receptor antibody were still present. Hyperglycaemia was noted during hospitalization and DM confirmed by oral glucose tolerance test. Muscle biopsy showed ragged red fibres. DNA analysis showed an A-to-G transition at the 3243rd nucleotide position of the tRNA(Leu(UUR)) gene of the mtDNA from the patient. Quantitative polymerase chain reaction (PCR) and restriction analysis revealed that about 60% of the blood mtDNA was of mutant type. The patient received antithyroid drugs for hyperthyroidism, diet control for DM and anti-epileptic drugs for seizure.

Adult↗
PubMed1995

Impact of decreased serum transaminase levels on the evaluation of viral hepatitis in hemodialysis patients.

The value of serum transaminases (ST) in evaluating hepatitis B (HBV) and C (HCV) infection was studied in 217 hemodialysis (HD) patients and 804 normal controls. Mean serum aspartate aminotransferase (AST) was 22.3 (22.0-22.7) and 22.6 (21.6-23.6) IU/l or 0.371 (0.366-0.378) and 0.376 (0.36-0.393) mu kat/l in controls and HD patients, respectively (nonsignificant), while mean serum alanine aminotransferase (ALT) was 20.3 (19.9-20.7) and 16.3 (15.3-17.3) IU/l or 0.338 (0.331-0.345) and 0.271 (0.255-0.288) mu kat/l in these two groups (p < 0.001). However, both AST and ALT became significantly depressed in HD patients after adjusting for age, gender, HBV surface antigen (HBsAg) and anti-HCV. The usual practice of regarding AST and ALT as being 'abnormal' in evaluating viral hepatitis when they exceeded the upper reference range (40 and 46 IU/l or 0.666 and 0.766 mu kat/l in our laboratory) was then critically assessed by the receiver operating characteristic (ROC) curve. ROC analysis showed that ST was useless in detecting HBsAg, while the best cutoff point for detecting the presence of anti-HCV was 18 IU/l (0.3 mu kat/l) for AST and 16 IU/l (0.266 mu kat/l) for ALT in HD patients, respectively. These are considerably lower than the conventional criteria for an 'abnormal' ST. We conclude that ST are decreased in HD patients and that the cutoff value of ST for detecting HCV should be set at lower levels to enhance their diagnostic yield.

Alanine Transaminase↗
PubMed1995

[The design and application of speech signal processing system by computer in stomatology.].

In this study we established a computer bases on Speech Signal Processing System and changes of formant frequencies of the vowel/i/accompany the changes in the oral cavity after maxillary surgery and prosthodontic reconstruction.The study found the F1 for vowel/i/has no change,while the F2 peak significantly shifted between the preprosthetic and postprosthetic speaking condition after anterior resection of relative energy error value and the speech intelligible measured aurally(P<0.05).

English Abstract↗
PubMed1995

[Static palatography and image processing system by computer.].

In this study the artificial palates made of black vinyl seat covering the palate and occlusal surfaces of maxillary teeth were coated with white alginate powder and inserted into the mouth of the subjects.After pronunciation of the test sounds,the tongue contact areas on artificial palate were demonstrated by wetting of powder and changing in color from white to black.Thus,photographnys of palatograms were taken.After taking 5 palatogram of each sound,the samples were averaged by an image processor.The averaged outline of each subject's palatogram was converted into a standarized dental arch form,with the gray scale of each image reversed and reduced,and then added to every pattern of the same sound produced by all subjects.Thus,palatograms were based on the frequency of over lapping.From this compiling, contact areas that were common in more than four out of six subjects were extracted.

English Abstract↗
PubMed1995

Does endothelin play a role in the pathogenesis of early diabetic nephropathy?

Endothelin-1 (ET-1) causes dramatic vasoconstriction and reduction of renal blood flow, with a decreased glomerular filtration rate (GFR). Early diabetic nephropathy is characterized by elevation of GFR and the formation of intrarenal microaneurysms. However, the mechanisms are unclear. To elucidate the pathophysiologic significance of urinary ET-1 in early diabetic nephropathy, the 24-h urinary excretion of ET-1 in 12 normal subjects and 20 patients with newly diagnosed type 2 diabetes mellitus were determined by a highly sensitive radioimmunoassay. The 24-h urinary ET-1 excretion in patients with diabetes mellitus (14.2 +/- 3.1 pmol, mean +/- SEM) was significantly lower (p < 0.05) than that of normal subjects (25.0 +/- 3.7 pmol). This decrease in urinary excretion of ET-1 in patients with recent-onset diabetes mellitus suggests a possible role of ET-1 in the pathogenesis of early diabetic nephropathy.

Adult↗