Search PubMed⌕ Search

Biomedical subjects

H Y Liu

Publications and source records attributed to H Y Liu.

At least 73 records · Page 4Linked to original sources
PubMed1993

Hemodynamic evaluation of bovine pericardial xenograft valves in the mitral position by stress Doppler echocardiography.

The function of a bovine pericardial xenograft valve in the mitral position was studied in 18 patients by using stress Doppler echocardiography after submaximal supine exercise. In 10 patients with normally functioning tissue valve, peak and mean gradients increased from 9.3 +/- 1.3 and 2.7 +/- 0.7 mmHg, respectively at rest, to 14.7 +/- 0.9 and 4.1 +/- 1.0 mmHg at peak exercise. The tissue valve area assessed by the Doppler pressure half-time method increased from 2.69 +/- 0.38 cm2 at rest, to 3.15 +/- 0.38 cm2 at peak exercise (P < 0.05). In 6 patients with mitral regurgitation, peak and mean gradients increased from 17.3 +/- 5.3 and 7.0 +/- 1.8 mmHg, respectively at rest, to 24.3 +/- 5.0 and 9.0 +/- 2.6 mmHg at peak exercise, but there was no significant change in valve area at peak exercise. Patients with severe isolated mitral regurgitation had a Vmax of more than 2 m/s and elevated pressure gradients at peak exercise. But the pressure half-time was relatively unaffected, allowing their differentiation from patients with tissue valvular stenosis. Stress Doppler echocardiography is a simple, noninvasive and reliable method for the evaluation of the mitral tissue valve function which is recommendable for patients with suspected mitral tissue valve dysfunction.

Adult↗
PubMed1991

Chemotherapy of head louse (Pediculus humanus capitis) infestation gamma benzene hexachloride (gamma-BHC) among school children in Szu-Hu District, Yunlin County, Central West Taiwan.

In order to evaluate the effectiveness of 1% gamma-BHC emulsion against head louse infestation, 1,527 school children were examined using observation by ocular and combing methods were used and infested children were treated with three regimes of 1% gamma-BHC emulsion. An overall infestation rate of 40% was found. The infestation rate was highest in Tung-Kuang Primary School (59%) and lowest in Chien-Hua Primary Schools (7%). The rate was highest among school children grade 2 (45%) and lowest in grade 3 (35%). The rate of girls (65%) was much higher than that of boys (9%). A total of 443 lice were collected from 78 infested school girls: 56 males, 59 females, and 328 nymph. The average number of head lice in each infested girl was 5.7. Follow-up examination was conducted one week after treatment. The cure rates for dosages of 10.0 ml, 5.0 ml, and 2.5 ml 1% gamma-BHC emulsion were 96%, 88%, 68% for girls and 100%, 92%, and 33% for boys, respectively. Only mild and transient itching and burn sensation of scalp were reported by a few children. The overall infestation rate 5 months (April-September 1981) after treatment was 23% (286/1,245). The rate of girls decreased from 65% to 40% and that of boys from 9% to 3%. Results of the present study indicates that 1% gamma-BHC emulsion is an effective pediculicide at a dosage of 5 ml or 10 ml. However, the overall infestation rate remained high (23%) 5 months after treatment. These findings suggest that treatment of head louse infestation must be conducted continuously.

Adolescent↗
PubMed1991

[Changes in parameters of hemorheology and circulation 6-keto-PGF1 alpha and TXB2 in dilated cardiomyopathy].

The changes in 12 parameters of hemorheology were observed and the levels of peripheral plasma 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and thromboxane B2 (TXB2) measured in 35 cases of dilated cardiomyopathy (DCM), including 6 peripartum cardiomyopathy (PCM). We found that there is of hyperviscosity in DCM, the causes were decrease of erythrocyte deformability, increase of red blood cell aggregation, increase of plasma fibrinogen and TXA2 level and decrease of plasma 6-keto-PGF1 alpha level.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

Risk factor analysis of an epidemic of hepatitis A in a factory in Shanghai.

Investigation of an epidemic of hepatitis A which occurred in Shanghai in early 1988 was conducted at the Shanghai No. 2 Yarn Dyeing and Weaving Mill. In this factory the attack rate between January and April 1988 was 9%. The rate was highest among staff who ate raw clams (18%) and higher among those who ate cooked clams (7%) than among those who did not eat clams (2%). In addition, independent risk factors for infection were: age below 30 years (relative risk (RR) = 3.0, 95% Cl: 2.0, 4.5) shift work (RR = 3.3, 95% Cl: 1.9, 5.8) and eating out (RR = 4.7, 95% Cl: 2.3, 9.7). Consumption of clams contaminated with hepatitis A was the main risk factor in this episode. The study indicates that strengthening surveillance of shellfish hygiene is important in preventing future epidemics of hepatitis A.

Adult↗
PubMed1990

[Purge of malignant cells from bone marrow by hematoporphyrin derivatives and light exposure in vitro].

During autologous bone marrow graft in treatment of malignant diseases, it is critical to purge malignant cells from the marrow. In the present study, the sensitivity to photodynamic inactivation of 3 leukemic cell lines was compared with their counterpart normal hematopoietic cells. After mouse leukemic L1210 cells were treated with a preparation of hematoporphyrin derivatives, YHpD, 10 micrograms/ml for 1 h and irradiated with black light (peak wavelength 395 nm, light intensity 0.6 mW/cm2) for 5 min, the survival rate of clonogenic cells decreased to less than 10%, while that of bone marrow granulocyte-macrophage progenitor cells (CFU-GM) in DBA/2 mice remained at nearly normal level (greater than 80%). Similar results were obtained when human leukemic HL-60 cells were compared to human CFU-GM and mouse leukemic L615 cells to CFU-GM in 615 strain mice. It is suggested that hematoporphyrin photoradiation may be useful for selectivity killing leukemic cells in bone marrow.

Animals↗
PubMed1989

Adult Hirschsprung's disease.

This report presents a series of 17 patients with adult Hirschsprung's disease treated at the National Taiwan University Hospital and its affiliated hospitals from 1965 to 1988. Adults with Hirschsprung's disease may present with symptoms and operative findings different from those of children with Hirschsprung's disease. The symptoms, signs, criteria for diagnosis, operative findings, and operative procedures are presented.

Adolescent↗
PubMed1989

Real-time, multiplanar computerized tomography: a new diagnostic modality used in the detection and endoscopic removal of a distal ureteral fibroepithelial polyp and adjacent calculus.

Ureteral fibroepithelial polyps are rare benign mesodermal tumors that occur predominantly in the upper ureter. We report on a patient with a fibroepithelial polyp in the distal ureter that resulted in entrapment of a calculus and partial obstruction of the collecting system. Preoperatively, diagnosis by standard radiographic methods, such as excretory urogram, retrograde pyelogram and conventional computerized tomography with and without contrast enhancement, was not possible because of the close proximity of the fibroepithelial polyp, the ureteral calculus and calcifications in the adjacent internal iliac artery. The new diagnostic modality of real-time, multiplanar computerized tomography imaging using the Sun/Pixar computer system and the 2D/3D Orthotool software was used to make the correct preoperative assessment. Subsequently, the patient underwent ureteroscopic resection of the polyp and extraction of the calculus. A year later she was free of symptoms and there was no evidence of regrowth of the polyp. To our knowledge this is the first report to describe the use of real-time, multiplanar computerized tomography imaging as an effective diagnostic modality in the genitourinary tract. In addition, this is the first ureteral fibroepithelial polyp reported in the literature to be associated with a ureteral calculus and to be excised endoscopically with no recurrence on long-term followup.

Endoscopy↗
PubMed1989

Experiences in the treatment of electrical burns covering deep wounds with various tissue flaps.

From 1979 to 1986, 121 patients with electrical burns were admitted to our, unit (6% of all the burned patients admitted during that period). Of these cases 64 were regarded as having deep burns (e.g. burns which injured muscles, tendons, nerves, bones and capsules of the joints etc.). Thirty-five flaps of various types of tissues (including one free muscle flap, two island fascial flaps, four island skin flaps, three arterial skin flaps, two musculocutaneous flaps and twenty-three random skin flaps) were used for the coverage of deep burns in twenty-seven patients. Thirty three flaps survived completely while two were partially lost; three flaps developed severe sub-flap infections but the tissue of the flaps survived totally. Three typical cases are reported in this paper. The advantages of early extensive exploration and thorough debridement of the deep electrical wounds are discussed. It also introduces the practical usage of various flaps for wound coverage in these typical cases. When flaps were needed for deep electrical burns, we chose local flaps first, and used axial pattern flaps, island flaps, etc. as much as possible; if only a random flap was available in the site, we elevated it with some deep fascia to enhance its ability to prevent infection. We considered the free tissue transfer and the transfer of fascial flaps to be important alternatives. Debridement followed by immediate wound coverage should be done as soon after resuscitation as possible. Generally the operations were performed within the third to fifth days after the electrical burn. This is the best period for active treatment in order to salvage the remaining functions of the burned extremities. Operations performed after six days must be done only under the careful control of anti-infective measures. From our experience we have found that muscle flaps and musculocutaneous flaps were the most suitable approaches for the coverage of deeply infected wounds especially when bones were involved. Careful attention was taken to excise the necrotic muscle tissues, especially those that were "sandwiched" between necrotic muscle bundles. This was done primarily by gross evaluation according to the judgement of the surgeon intraoperatively. The swollen and hardened regions of the skin of involved extremities generally corresponded to the areas of necrotic muscle tissue at about three days after the injuries or later. This was used as a reference to indicate where to place or extend the exploratory incisions. We frequently preserved denatured peripheral nerves and tendons, because these injured structures often later regain their functions partially or completely with a reliable coverage.(ABSTRACT TRUNCATED AT 400 WORDS)

Accidents, Occupational↗
PubMed1989

An analysis of prognostic factors in cirrhosis.

To develop a more comprehensive index for predicting the prognous of liver cirrhosis. 300 consecutive patients with cirrhosis were studied in terms of survival from 1975 to 1986. Median follow-up period was 5.3 years. A multivariable survival analysis (Cox's regression model) using clinical biochemical data obtained at admission disclosed eight factors of value in predicting prognosis: age, frequency of previous GI bleeding, ascites, hepatic encephalopathy, serum albumin, serum bilirubin, hemoglobin and prothrombin time. A prognostic index was constructed for the calculation of the estimated survival probability.

Adult↗
PubMed1989

[The significance and state of pre-S2 and antibodies to pre-S2 in 30 cases of acute viral hepatitis type B].

Determination of time sequence of pre-S2 and its antibody response during the symptomatic phase of acute viral hepatitis type B, as well as their relationship to the HBV-markers, was carried out in 30 subjects after the onset of liver damage by means of monoclone antibody-captured enzyme immunoassay were analysed. The results showed that anti-pre-S2 were positive in 80.3% of patients recovering from acute viral hepatitis type B, being higher than the percentage during maximal liver damage (P less than 0.001). Such antibodies were absent in cases showing chronic evolution and were found in less than 8% of chronic hepatitis B cases, with no relation to liver damage. Anti-pre-S2 were detected after the immune clearance of HBsAg and HBV-DNA, and thereafter the anti-HBs were present in 80% of patients after recovery (P less than 0.001). Our observations significantly suggest that anti-pre-S2 may be valuable as a marker of the favourable prognosis of acute viral hepatitis type B and of HBV clearance. They did not play any role in the pathogenesis of HBV-related liver damage. The continuous presence of pre-S2 with the absence of anti-pre-S2, on the contrary, is considered as a characteristic sign and a new information of chronic viral hepatitis type B.

Acute Disease↗
PubMed1989

[Studies on the chemical components and anti-tumour action of the volatile oils from Pelargonium graveoleus].

Three geranium oils were separated, identified and compared by high resolution cross-linked fused silica capillary GC and GC-MSD. It was found that their chemical constituents are very similar, but the contents of some components (linalool, citronellol, cis-caryophyllene and guaiene) differ appreciably. Pharmacological experiments showed that citronellol, citronellyl formate, geraniol and citronellyl acetate exhibited marginal antitumour activities. The activity of the latter two components has not been reported in the literature.

Acyclic Monoterpenes↗
PubMed1989

[Optimum number of mixed peripheral blood samples by membrane filtration technique for mass blood survey of filariasis].

The membrane filtration technique has been used widely in the evaluation of effect of control and survey of filariasis. The present study was made to explore an optimum number of mixed peripheral blood samples and a mathematical model of work load for this method in surveying filariasis. By analysing the correlation between the microfilaremia rate and the optimum number of mixed peripheral blood samples and applying the theory of Binomial Distribution or Poisson Distribution, the authors reckoned a table for estimating the number of filariasis cases in villages with different microfilarial rates and different population as well as the optimum number of mixed peripheral blood samples.

Animals↗
PubMed1989

[Use of baculovector for the expression of HBsAg gene in insect cells].

Based on the information of molecular biology of Autographa californica Nuclear Polyhedrosis virus (AcNPV), a recombinant transfer plasmid pAcMV was constructed by molecular procedures included using two synthetic localized probes, which provided an inserted position linked with BamHI sequences nearly at polyhedrin initiating ATG codon. Then an expression vector pAcMV-HBsAg was reconstructed, it contained HBsAg gene from subclone pYPSS-1 derived from adwserotype of HBV. The recombinant virus containing HBsAg gene was isolated and purified through 3 cycles plaques and hybridization experiment after cotransfection of Spodoptera frugiperda cells with DNA of pAcMV-HBsAg and AcNPV. The expression of HBsAg gene in S. frugiperda cells infected with recombinant virus AcRV-HBsAg was identified by ELISA as haemagglutination tests. The yield of HBsAg excreted from S. frugiperda cells (an appropriate density usually between 1-2 X 10(6) cells/ml) after 48-72 h infected with AcRV-HBsAg was 4-8 mg/L. HBsAg harvested from the infected culture medium was shown immunoelectromicroscopy to be composed of spherical particles of about 22 nm diameter. Using this purified HBsAg, Bal b/c mice was immunized, the titer of anti-HBsAg serum measured measured by RIA was similar to that of purified HBsAg from human blood. Stable recombinant virus was isolated and could be shown to replicate in corn borer (Ostrinia nubilalis) larvae. All of these results can be expected that this expression vector system will be commercially developed to its fullest potential for diagnosis and vaccine HBsAg.

Animals↗