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Biomedical subjects

C Liu

Publications and source records attributed to C Liu.

At least 379 records · Page 21Linked to original sources
PubMed1999

Randomised, double blind, placebo controlled study of interferon beta-1a in relapsing-remitting multiple sclerosis analysed by area under disability/time curves.

OBJECTIVES: The commonly employed outcome measures on disability and relapse rates in treatment trials of relapsing-remitting multiple sclerosis have well demonstrated sensitivity to treatment effects, but their clinical interpretation is problematic. An alternative method of analysis, which is more clinically meaningful and statistically appropriate to a condition with a fluctuating disease course, uses the summary measure statistic "area under the disability/time curve (AUC)", to estimate each patient's total in trial morbidity experience. METHODS: The AUC technique was applied in an intention to treat analysis of serial disability data derived from the expanded disability status scale (EDSS), the Scripps neurologic rating scale (SNRS), and the ambulation index (AI), collected during a double blind, randomised, placebo controlled, phase III trial of subcutaneous interferon beta-1a (INFbeta-1a) in relapsing-remitting multiple sclerosis (PRISMS Study). The results were compared with the often quoted "conventional" end point of mean change in rating scores from baseline to trial completion. Analyses were also carried out on subgroups with entry EDSS stratified above and below 3.5. RESULTS: EDSS data analysed by AUC normalised to baseline scores disclosed that both doses of IFNbeta-1a (22 or 44 microg) were superior to placebo (p= 0.008 and 0.013, respectively). In addition, the high dose (44 microg) was more beneficial than placebo using SNRS (p= 0.038) and AI data (p= 0.039). AUC analysis of SNRS scores also showed that for patients with baseline EDSS>3.5, the 44 microg (but not the 22 microg) dose was more advantageous than placebo (p=0.028). CONCLUSIONS: Summary measure analysis using the AUC of serial disability/time plots, confirms and extends the results of conventional end point analysis of disability from the PRISMS Study data. AUC evaluations show that high dose INFbeta-1a (44 microg three times weekly) was beneficial on all of the clinical rating scale scores used in this study. This method provides a statistically powerful and clinically meaningful assessment of treatment effects on in trial disability in patients with multiple sclerosis with fluctuating and highly heterogeneous disease courses.

Analysis of Variance↗
PubMed1999

Assessing relapses in treatment trials of relapsing and remitting multiple sclerosis: can we do better?

Published Phase III immunomodulatory treatment trials in relapsing and remitting multiple sclerosis have demonstrated a modest decline in attack rates, but only a minor effect on disability. As genuine disability progression is difficult to ascertain in relatively short studies with the conventional rating scales available, the acquisition and analysis of relapse data are critical. However, there are as yet unresolved questions related to the latter. We will first discuss the problems associated with relapse definitions by trial investigators, the paucity of the data collected (especially on the magnitude and duration of exacerbations) and statistical issues in their analysis. We will then suggest practical points for obtaining more accurate information on relapses and evaluating them meaningfully. While there is still general consensus among neurologists that primary endpoints for therapeutic trials should be clinical, improvements for future protocols are essential.

Clinical Trials as Topic↗
PubMed1999

Virulizin(R) - A review of its antineoplastic activity.

Virulizin(R) (registered trademark of Lorus Therapeutics, Inc.) is a novel biological response modifier (BRM) that enhances cell-mediated immune response to tumour cells by direct macrophage activation. The agent, an aqueous solution containing a 5% (w/v) solid material mixture comprised of inorganic salts (95 - 99% of the dry weight) and organic compounds of molecular weight < 3000 Daltons (1 - 5% of the dry weight), is provided as a sterile, injectable formulation. Virtually all the organic compounds and ionic components in the mixture have been identified by chemical and spectroscopic methods. Virulizin(R) is obtained from bovine bile by a standardised process involving solvent extraction and heat hydrolysis. In vitro studies have shown that Virulizin(R) can stimulate blood monocytes, peritoneal macrophages and alveolar macrophages from patients with malignant and non-malignant diseases to mediate a level of tumour cell cytolysis that is equal to, or greater than, that elicited in the same cells by other, more conventional biological activators. Other studies have shown that the stimulation of cytotoxic function by Virulizin(R) is insensitive to the inhibitory effects of prostaglandins and, hence, is distinct from many other activators. Furthermore, the blood monocytes of patients currently receiving cytotoxic chemotherapy showed activation with Virulizin(R). In preclinical studies, Virulizin(R) showed modest inhibition of tumour growth in a human pancreatic cancer xenograft model (T/C, 0.60; p = 0.012) and increased survival time by 8% (p = 0.046) in a murine melanoma model. Toxicity studies in rats indicated that Virulizin(R) injected intramuscularly was well-tolerated by the animals. Except for a lower rate of body weight gain in the high dose group, no toxicological effect related to treatment was observed in a chronic 13-week study (three weekly im. injections of up to 1.1 ml/kg). Mutagenicity studies with Virulizin(R) were negative. Many Phase I/II and Phase II clinical trials were carried out with Virulizin(R) to evaluate the safety and efficacy of the agent to treat cancer patients. Three of those studies involved the treatment of patients with pancreatic adenocarcinoma. The majority of patients participating in these studies were those who had failed conventional treatment including surgery or chemotherapy. Disease stabilisation was observed in patients treated with Virulizin(R), and, based on a meta-analysis of the data from the three studies, the survival of the patients treated with Virulizin(R) was better than a similar patient population receiving standard chemotherapeutic agent for that disease indication. However, randomised studies may be required to confirm the effect of Virulizin(R) on disease stabilisation and survival. In the three studies on patients with malignant melanoma, at least 69% treated with Virulizin(R) showed no additional deterioration or had improved at four weeks with response being only slightly reduced after eight weeks. In the evaluation of safety, assessed overall from these clinical studies in 200 patients treated with Virulizin(R), the number and severity of adverse events were small. In conclusion, Virulizin(R) is a novel, clinically non-toxic biological response modifier that appears to have a clinical effect on disease stabilisation and survival in patients with pancreatic cancer and malignant melanoma. However, additional randomised studies may be required to confirm those effects. Future studies on Virulizin(R) will focus on the characterisation of the active components in the agent and the development of a synthetic formulation. Subsequently, the preclinical and clinical pharmacokinetics of Virulizin(R) will be determined and studies to optimise the human dose of the agent will be carried out.

Journal Article↗
PubMed1999

[Molecular characterization of glucose-6-phosphate dehydrogenase variants in four ethnic groups in Yunnan province of China].

OBJECTIVE: In order to understand the molecular evolution, race origin and the relationship between the G6PD gene structure and clinical symptoms, the authors identified the molecular characterization of glucose-6-phosphate dehydrogenase and determined the G6PD gene frequency in four ethnic groups in Yunnan province of China. METHODS: The point mutations of G6PD were detected by Mismatch-PCR/RE, SSCP,ARMS,DNA sequence and so on. G6PD gene frequency was determined by Hardy-Weinberg Law. RESULTS: G6PD G1388A, G1376T,A95G mutations were determined in Bai and Dai people for the first time and G1388A also in Harni people by DNA sequence. G6PD C1024T were detected in Dai population by Mismatch-PCR/RE. The gene frequency of G6PD in Bai population in Dali city is 0.0113, and the incidence is 1.19% which are different from those in Dai population. CONCLUSION: G6PD G1388A,G1376T, A95G and C1024T are the mutations in national minorities as well as in the Han people. The results suggest that different national minorities of China may have the same ancestor. The incidence of G6PD deficiency and the G6PD gene frequency in Bai population are different from those in Dai population. The distribution of G6PD deficiency in Yunnan is associated with the distribution of malaria epidemic in that province.

China↗
PubMed1999

Light treatment enhances photoreceptor survival in dystrophic retinas of Royal College of Surgeons rats.

PURPOSE: To determine whether treatment with bright light elicits a protective response that enhances photoreceptor survival in Royal College of Surgeons (RCS) rats with inherited retinal degeneration. METHODS: RCS rats were illuminated for 10 to 12 hours with 130 foot-candles (fc) of white or green light. Untreated littermates that were kept under low cyclic light levels were used as control subjects. Photoreceptor survival was determined by quantitative analysis of photoreceptor nuclei and ultrastructural assessment of cellular organization. Basic fibroblast growth factor (bFGF) and ciliary neurotrophic factor (CNTF) gene expression were determined at the mRNA and protein levels. RESULTS: Treatments of RCS rats with a single dose of bright light on postnatal day 23 (P23) greatly enhanced photoreceptor survival. Ultrasturctural analysis revealed intact inner segments in light-treated retinas, whereas in untreated retinas only remnants of inner segments were observed. By P42, numerous viable nuclei were counted in the posterior retina of light-treated rats, whereas most of the remaining nuclei in untreated RCS rat retinas were highly pyknotic. At 2.5 days after treatment with a single dose of bright light, bFGF gene expression was significantly higher than in untreated RCS rat retinas. By P42, bFGF protein levels were still significantly higher in the treated retinas. CONCLUSIONS: Exogenous bFGF has been shown to promote photoreceptor survival in the RCS rat retina. Thus, the increased bFGF expression that was measured in the light-treated RCS rat retinas may be a protective response to light stress, which supports the observed rescue of photoreceptors in light-treated RCS rat retinas.

Animals↗
PubMed1999

[CAG trinucleotide mutation detection in patients with hereditary spinocerebellar ataxia].

OBJECTIVE: To assess the frequency of the SCA1, SCA2,SCA3/MJD, SCA6, SCA7 and DRPLA CAG trinucleotide repeat expansions(CAG)n among individuals diagnosed with hereditary spinocerebellar ataxia(SCA) from Chinese families. METHODS: The SCA1, SCA2, SCA3/MJD, SCA6, SCA7 and DRPLA(CAG)n mutations were detected by polymerase chain reaction (PCR), denaturing polyacrylamide gel electrophoresis and silver staining technique in 167 patients with autosomal dominant SCA from 85 Chinese families and 37 sporadic SCA patients. RESULTS: Among 85 families, four families(4.70%) had seven SCA1 patients with the CAG repeat expanded to 53 to 62 repeats, five (5.88%) had twelve SCA2 patients with the CAG repeat expanded to 43 to 47 repeats, and 41 (48.23%) had 83 SCA3/MJD patients with the CAG repeat expanded to 68 to 83 repeats. Analysis of the mutation in these families showed a strong negative correlation between the size of the expanded CAG repeat and the age of disease onset. None of the SCA patients were positive for SCA6, SCA7, or DRPLA. Nor was any of the sporadic SCA patients positive for the CAG repeat expansion in the SCA1, SCA2, SCA3/MJD, SCA6, SCA7, or DRPLA gene. CONCLUSION: The frequency of SCA3/MJD is substantially higher than that of SCA1 and SCA2 in the autosomal dominant SCA from Chinese families. Chinese SCA3/MJD patients are non-Portuguese. Clinical expressions of the various SCAs overlap one another and hence can make the phenotype-based diagnostic classification inaccurate in many instances. It is important for SCA clinical studies to make an SCA gene diagnosis and genotype analysis.

Adult↗
PubMed1999

Effect of aerobic training on orthostatic tolerance, circulatory response, and heart rate dynamics.

BACKGROUND: This study was performed to investigate the effects of aerobic training on orthostatic tolerance and to quantify the post-training changes in cardiovascular response and heart rate variability (HRV). METHODS: Tolerance and circulatory responses to two types of lower body negative pressure (LBNP) were examined and compared in a group of healthy male students before and after 6 mo of aerobic training, and the results were further compared with a group of athletes (runners). Changes in HRV associated with training were analyzed by conventional and time-varying autoregressive spectral analysis, as well as by approximate entropy measurement (ApEn)--a statistic quantifying heart rate "complexity" derived from non-linear dynamics. RESULTS: After aerobic training, there was an initial transient hypotension during the supine -50 mmHg LBNP testing and a significant decrease in tolerance to upright graded LBNP in most of the student-subjects. Moreover, after training, there was a significant decrease in ApEn value of the HRV time series during both supine control and LBNP testing, and the rate of cardiac vagal withdrawal and sympathetic activation during the onset of LBNP was faster than that before training. CONCLUSIONS: The present study has provided further evidence that certain types of aerobic training may affect orthostatic tolerance and may be associated with a loss of complexity of HRV during supine resting and orthostatic stress.

Adaptation, Physiological↗
PubMed1999

[Changes and significance of natural killer cell, IL-2, IL-6 and TNF alpha of heroin addicts after detoxification].

In order to find out the activity of NKC and production of IL-2 in the peripheral blood mononuclear cells and the level of IL-6 and TNF alpha in the peripheral blood serum, we investigated 51 herion addicts who were in the course of detoxification. MTT colorimetric assay and ELISA assay methods were adopted. The results showed that, in the herion addicts, NK activity was 30.11 +/- 5.2%, IL-2 activity was 8.06 +/- 1.66 IU/ml, IL-6 level was 61.17 +/- 12.07 pg/ml, and TNF alpha level was 91.83 +/- 19.19 pg/ml, whereas in the healthy controls, the results were 44.89 +/- 4.75%, 15.91 +/- 3.83 IU/ml, 22.18 +/- 9.31 pg/ml and 30.55 +/- 11.94 pg/ml respectively. When the herion addicts were subjected to detoxication, their NKC and IL-2 activities, IL-6 and TNF alpha levels gradually restored to normal, and were correlated with the time of their detoxification (NKC: r = 0.626, P < 0.001; IL-2: r = 0.684, P < 0.001; IL-6: r = -0.791, P < 0.001; TNF alpha: r = -0.703, P < 0.001).

Adult↗
PubMed1999

[Cleft lip repair using a lateral columellar flap].

OBJECTIVE: Since the important cosmetic structures of a good looking lip, viz. the philtrum column, philtrum dimple and Cupid's bow of a cleft lip repaired with the commonly used methods, are still defective in various degrees, a new method is designed. METHODS: On the medial side of the cleft, the short philtrum is lengthened and the upwardly displaced Cupid's bow maintained in a lowered position by a rectangular flap transplanted from the lateral surface of the columella. No lip flap has been formed on the lateral side of the cleft. RESULTS: In a period of three years (1996-1998), 23 cases of unilateral cleft lip, 9 cases of bilateral cleft lip and 14 cases of secondary deformities of cleft lip have been repaired with this new method. All of the repaired lips have normal looking philtrum column (limited by an uninterrupted straight-line scar), philtrum dimple and Cupid's bow. CONCLUSION: The lateral columellar flap method is a more rational surgical procedure for cleft lip repair in that it repairs tissue defect by transplanting tissue from the unexposed area. The appearance of the repaired lip is better than that of the commonly used methods.

Cleft Lip↗
PubMed1999

[Tissue response in circum-maxillary sutures after transverse palated suture expansion].

OBJECTIVE: This study was carried out to investigate the histological reactions of midfacial sutures induced by transverse palatal suture expansion. METHODS: Nine mongrel dogs of 8-week old were used in the study. Six of them were used as experimental group as described in a previous paper. The additional three served as controls. In the experimental dogs, a NiTi-shape memory alloy (NiTi-SMA) arch wire was used to expand the transverse palatal suture. Tetracycline was injected intramuscularly (50 mg/kg) three days before operation and at the time of sacrifice. Tissue reactions of premaxillo-maxillary suture, transverse palatal suture, zygomatico-maxillary suture, zygomatico-temporal suture and fronto-maxillary suture were observed in undecalcified tetracycline labeled sections and decalcified histological sections. RESULTS: The sutures in normal young dogs showed active bone formation. With the increase of age, the cellular components of the suture decreased. A great amount of new bone apposition was found in the bony front of expanded transverse palatal suture of the experimental dogs. Degenerative changes were found in premaxillo-maxillary suture at the expanded side while the contralateral showed active osteogenesis. Other sutures manifested both bone apposition and deposition due to the irregular interdigitations. CONCLUSION: After expansion, a great amount of new bone formed in the transverse palatal suture and thus the hard palate was lengthened. All the circum-maxillary sutures reacted in different patterns.

Animals↗
PubMed1999

[Suture expansion osteogenesis for closing the posterior hard palate: an experimental study in dogs].

OBJECTIVE: This study investigated the possibility of a new approach, e.g. suture expansion osteogenesis for closing the posterior hard palate. By this technique we might hope to replace missing tissue in the clefts by tissue regeneration and achieve bony repair in the posterior hard palate and circumvent the problems of speech and facial growth seen in traditional cleft surgery. METHODS: Nine 8-month mongrel dogs were divided into three groups: the control(n = 1), sham control(n = 2) and the experimental group(n = 6). In six experimental dogs, an 8 mm wide cleft was made surgically. Suture expansion devices made of NiTi-shape memory alloy with force levels of 200 g, 360 g and 480 g were secured in the palatine bones to expand the lateral sutures of the palatine bones. Clinical and histological examinations were performed to observe the changes. RESULTS: The clefts in the experimental group were closed completely sooner or later within a period from 5 to 14 days. While the clefts in the sham group became a little larger than their original size. There was significant new bone formation at the edge of the expanded suture. CONCLUSION: The clefts in young dogs could be closed by the technique of suture expansion. The NiTi-SMA expander used in the study was consistently effective and all the force levels could induce a great amount of new bone formation with the trabeculae being thinner and longer by heavy forces.

Animals↗
PubMed1999

[Hard palate lengthening by palatal suture expansion: an experimental study in dogs].

OBJECTIVE: Scar contraction and lack of bony support for soft palate in traditional surgery of cleft palate are main causes of a shortening soft palate and its developmental deficiency. The wound and scar also lead to aberration of facial growth. In order to resolve these problems, lengthening of hard palate by transverse palatal suture expansion was studied. METHODS: Six mongrel dogs of 8-week age were used in the study. Amalgam markers were implanted in the hard palate of the animal. A NiTi-shaped memory alloy (NiTi-SMA) arch wire with a force level of 600 g was used to expand the palato-maxillary suture with a retention period of 8 weeks. The dogs were killed at the age of 36 weeks. Serial X-ray and cephalometry were used to investigate the changes. RESULTS: The suture expansion was generally completed in 4 weeks. The distance of separation of the palatine bone and maxilla was 1.0 to 1.5 cm. Premaxilla became protrusive significantly at the beginning of the suture expansion, then restored gradually to its original position. The length of hard palate increased 4.6 to 5.9 mm by dry skull measurement. CONCLUSION: Hard palate could be permanently lengthened anterior-posteriorly by transverse palatal suture expansion.

Animals↗
PubMed1999

Subclavian steal syndrome: report of 28 cases.

OBJECTIVE: To study the experience in the treatment of subclavian steal syndrome (SSS) and the relation between SSS and the damage of brain. METHODS: In 28 patients with SSS, 23 were operated on. They complained of vertigo, TIA, and claudication of arms. One patient suffered from severe stem ischemia spasm. All the patients were subjected to subtraction angiography. Fifteen of them showed retrograde flow in the vertebral arteries. Transcranial Doppler revealed retrograde blood flow in 8 patients. Single photon emission tomography showed inadequate blood supply to the brain with affected subclavian arteries in 4 patients. Carotid-subclavian arterial bypass was performed in 16 patients, axilloauxillary bypass in 3, PTA in 1, and aorta-carotid graft bypass in 3. RESULTS: 13 patients (13/23) had their cerebrovascular symptoms relieved. Transcranial Doppler and emission tomography after operation showed nothing abnormal. CONCLUSION: SSS is harmful and the patients should be closely monitored by means of transcranial Doppler and emission tomography.

Adult↗
PubMed1999

[Follow-up study of lung function changes for 10 years in healthy elder of ex-smokers].

OBJECTIVE: To observe changes of lung function for 10 years in healthy elderly ex-smokers who have quitted smoking for more than 10 years. METHODS: 51 healthy elderly ex-smokers were selected and routine lung function tests were performed, 12 subjects, who have never smoked and all other criteria were similar, were chosen as controls. Their routine lung function tests have also been followed up for 10 years. RESULTS: The decrease of VC, FVC, FEV1 and PEF of ex-smokers were significantly lower than non-smokers, the increase of RV and RV/TLC were significantly higher than non-smokers. FEV1/FVC, MVV, MMEF, FRC and TLC were also different, however, the difference has not reached statistically significant. CONCLUSIONS: The influence of smoking could be prolonged, even the subject has stopped smoking for years, so we suggested to stop smoking the early the better.

Aged↗
PubMed1999

[Comparative study of conventional CT and spiral CT in diagnosis of lung cancer].

OBJECTIVE: To observe and compare the findings of lung cancer with conventional CT and spiral CT. METHODS: One hundred and thirty-four cases of pathologicalty confirmed lung cancer, including 56 centrally located and 78 peripherally located lung cancer, were examined by conventional CT and spiral CT, and their findings compared. RESULTS: In 30 of the 56 cases with central lung cancer, the lesion was located in the right bronchus and in 26 of them the lesion was in the left bronchus. On spiral CT, the display rate of obstructive findings and invasion to big vessels in the mediastinum was higher than that on conventional CT. There was no remarkable difference in density of the lesion and detection of metastasis in hilar and mediastinal lymph nodes between conventional and spiral CT. In 34 of the 78 cases with peripheral lung cancer, the lesion was in the right lung and in 44 was the lesion in the left lung. Calcification, air-bronchogram, cavity and pleural indentation of the lesion in the peripheral lung cancer were better displayed by spiral than by conventional CT. CONCLUSION: Spiral CT is superior to conventional CT in the observation of signs characteristic of central and peripheral lung cancers.

Adult↗
PubMed1999

[Effect of acupuncture on enzymology of motor neuron of anterior horn of experimental spinal cord injury in rats].

OBJECTIVE: To study the effect of acupuncture on enzymology of the motor neuron of anterior horn of injured spinal cord in rats. METHODS: Chemical staining method was used to quantitatively analyze the acetylcholinesterase (ACHE), succinate dehydrogenase (SDH), acid phosphatase (ACP), changes in motor neuron of anterior horn of spinal cord simultaneously, and auto-analysis photogram apparatus was used to quantitatively analyze. RESULTS: After spinal cord was injured, the AchE and SDH reduced, ACP raised; in the acupuncture group, ACHE and SDH were increased and ACP was lowered after acupuncture (P < 0.05, P < 0.01). CONCLUSION: Acupuncture could regulate enzymology of the motor neuron of anterior horn of injured spinal cord. Acupuncture could inhibit or delay the deterioration of neuron, and also could promote the recovery.

Acetylcholinesterase↗
PubMed1999

[Serapharmacological effect of fuzheng huayu 319 Decoction on expression of type I collagen and transforming growth factor beta 1 in hepatic stellate cells].

OBJECTIVE: To investigate the main serapharmacological mechanism of antifibrotic action of Fuzheng Huayu 319 Decoction (FHD) at cellular and molecular level. METHODS: Hepatic stellate cells (HSC) were isolated from the normal rats and subcultured. Normal rats were medicated with FHD and their blood serum collected to prepare the medicated serum, which was incubated with the subcultured HSC. Then, the extra- and intracellular collagen synthetic rates were assayed with collagenase digestion method, type I collagen content in the medium measured with ELISA, transforming growth factor beta 1 (TGF beta 1) protein production semiquantified by immunocytochemistry stain and image analysis system, the gene expressions of type I procollagen and TGF beta 1 analyzed by RT-PCR. RESULTS: FHD medicated serum could obviously inhibit the extra- and intracellular collagen synthetic rates, decreased type I procollagen mRNA expression and its secretion, downregulate TGF beta 1 mRNA and its protein expression. CONCLUSION: FHD could inhibit HSC activation markedly, the main mechanism of its antifibrotic action may be the medicated serum inhibition on type I procollagen and TGF beta 1 gene expression.

Animals↗