Biomedical subjects

R C Yang

Publications and source records attributed to R C Yang.

At least 37 records · Page 2Linked to original sources

PubMed1998

Albumin synthesis after intense intermittent exercise in human subjects.

We measured hepatic albumin synthesis in five volunteers (4 men and 1 woman) at 3 and 6 h after recovery from intense exercise. A primed-constant infusion of a stable isotopic tracer of phenylalanine was used to determine hepatic fractional synthetic rate (FSR) and absolute synthetic rate (ASR) of albumin from the enrichment of phenylalanine in albumin. The infusion of the stable isotope tracer began 2 h after upright exercise or upright rest. Albumin FSR and ASR were 6.39 +/- 0.48%/day and 120 +/- 9 mg.kg body wt-1.day-1, respectively, 3-6 h after recovery from exercise; the FSR and ASR on the time control study day were 5.94 +/- 0.47%/day and 104 +/- 9 mg.kg body wt-1.day-1, respectively. The 6 and 16% increases (P < 0.05) in FSR and ASR after exercise were associated with an elevated plasma albumin content at 5 and 6 h of recovery (P < 0.05), an increased total protein content throughout recovery (P < 0.05), and a negative free water clearance (P < 0.05) at 2, 3, and 6.5 h of recovery compared with baseline values; these variables were unchanged from their baselines on the time control study day. Increased albumin content and reduced free water clearance contribute to a retention of fluid within the circulation after intense exercise. The measured increase in albumin synthesis could not account for the entire increase in albumin content at 6 h of recovery from exercise. However, we estimate that if the increased activity was maintained for the next 18 h, it could account for the expected increase in albumin content at 24 h of recovery.

Adult↗

PubMed1998

Etiology, timing of insult, and neuropathology of cerebral palsy evaluated with magnetic resonance imaging.

To define the patterns of pathologic changes in cerebral palsy (CP) and to assess the etiology and time of brain damage, we reviewed the magnetic resonance images and clinical records of 86 pediatric CP patients seen over 8 years. Patients were divided into two groups, based on the gestational age at birth. The majority of CP patients (69) had spasticity. In the premature group (< 37 wk gestational age) n = 27), spastic diplegia (12 patients) and quadriplegia (8) were the major subtypes. In the term group (> or = 37 wk gestational age) ( n = 59), spastic hemiplegia (23) and quadriplegia (12) were most common. The other main clinical manifestations in the two groups were seizures (36) and mental retardation (15). Magnetic resonance (MR) imaging provided significant findings in 82 patients (95%). In the 27 patients born prematurely, MR imaging revealed periventricular leukomalacia (17), multicystic encephalomalacia (3), cortical and subcortical atrophy (4), migration disorders (2), and basal ganglia injury (1). Among the patients born at term, the MR imaging findings were more heterogeneous; they included cortical and subcortical atrophy (17), brain malformations (17), periventricular leukomalacia (6), multicystic encephalomalacia (5), porencephaly (4), hemiatrophy (3), delayed myelination (3), and none (4). MR imaging alone could define the time of brain insults in 73 of our 86 CP patients. Combined with clinical histories, MR imaging could help assess the time of insult in 93% of patients. The brain insults occurred prenatally in 34 of our patients, perinatally in 37, and postnatally in eight. The time of insult could not be determined in six patients. In the premature patients, the insult occurred most frequently perinatally (74%), whereas in the term group it occurred most frequently prenatally (54%). MR imaging was found to be very helpful in the evaluation of the various neuropathologic changes in CP, in the depiction of the etiology, and in the determination of the time of brain injury.

Adolescent↗

PubMed1998

Heat shock treatment decreases the mortality of sepsis in rats.

Sepsis is an increasingly common and lethal diagnosis in hospitalized patients. In spite of the advances in antibiotics and medical equipment, the mortality rate has not been improved in the last decade. Recently, heat shock proteins (Hsps) have been well documented to play a self-protective role in almost all living cells under various pathological and physiological stresses through a mechanism known as thermotolerance or cross tolerance. The present study was designed to investigate the expression of Hsp72 and the protective role of pre-induction of Hsps in the mortality during different phases of sepsis. Adult male Sprague-Dawley rats were employed in the study. Sepsis was induced by cecal ligation and puncture (CLP). Heat shock treatment was performed 16 hrs before sepsis induction by heating the rats whole-bodily with an electric heating pad under general anesthesia. The mortality rates with time in both control and preheated groups were monitored. Hsp72 was detected by SDS-PAGE, Western blotting and immunostaining in the brain, heart, liver, kidney, lung, adrenal gland, muscle and lymphocytes. The results show that both early (9 hrs post-CLP) and late (18 hrs post-CLP) sepsis failed to increase the synthesis of Hsp72. Previous induction of Hsps by heat shock treatment significantly decreased the mortality rate of late sepsis. Applying a sufficient inducer to lymphocytes of late sepsis reversed the synthesis of Hsp72 from inactive state into an over-expressive situation in vitro. These results suggest that Hsps are involved in the pathogenesis of sepsis and the involvement of Hsps during the progression of sepsis could add to a first line of host defense against invasive pathogens. Searching for an acceptable agent or less invasive method that leads to increased Hsps expression may provide a means for better treatment of severe infection.

Animals↗

PubMed1997

Effects of sonication on articular cartilage in experimental osteoarthritis.

OBJECTIVE: To investigate the histological effect of therapeutic ultrasound on arthritic cartilage of rats with various severities of induced osteoarthritis. METHODS: Twenty-seven rats with 3 different stages (Grade I, II, III) of papain induced knee arthritis received 7 min pulse sonication treatment, 3 times/week for 4 weeks. Another 27 rats with the same severity of induced arthritis were studied as controls. The severity of arthritis and related histopathological changes of articular cartilage were evaluated by bone scan and histological findings with hematoxylin and eosin stain. RESULTS: "Severity indexes" based on bone scan decreased after sonication treatment in each study group. Histopathological findings indicated marked cartilage repair in the early stage of induced arthritis (Grade I). However, progressive cartilage damage present in untreated Grade II, III induced arthritis was significantly reduced after sonication. CONCLUSION: Therapeutic ultrasound enhances cartilage repair in the early stage, and has the effect of arresting further deteriorative damage in the later stage of induced arthritis.

Animals↗

PubMed1997

The role of mucopolysaccharide induction in treatment of experimental osteoarthritis in rats by ultrasound.

Therapeutic ultrasound has been used in the treatment of osteoarthritis for the relief of symptom and improvement of functional status. In recent study, we found that ultrasound enhances cartilage repair in experimental early stage osteoarthritis, and prevents deteriorative changes in later stages. In the present study, we further investigate the bioeffects of ultrasound on cartilage matrix of experimental arthritis. Fifty-four rats with three different degrees of papain induced osteoarthritis classified by 99m-Tc pertechnetate bone scan were collected for ultrasound treatment. The changes in their arthritic severity after sonication treatment and two months after treatment were measured using 99m-Tc bone scan. The histopathological changes were evaluated through light microscope after disarticulation sections (H.E. stain), and the changes in mucopolysaccharide density in cartilage matrix were measured using a Optimas scanner analyzer after Alcian blue staining. The results showed that the density of mucopolysaccharide rose in the initial stage of induced arthritis, and decreased progressively in the later stage. The density of mucopolysaccharide increased upon complete sonication more for the treated rats than for the controls, and this was closely related with the improvement in histopathological findings, but inversely with the changes in arthritic severity. In conclusion, therapeutic ultrasound enhances mucopolysaccharide synthesis of arthritic cartilage, and results in the repair of arthritic cartilage in the early stage of induced arthritis and the prevention of deteriorative changes in later stages.

Animals↗

PubMed1996

Previous heat shock treatment attenuates bicuculline-induced convulsions in rats.

Exposure to elevated temperature provokes a sequence of events (heat shock response) in all living organisms. Through this response, heat shock proteins (HSPs) are induced and protect the cells against subsequent injury. We investigated the effect of heat treatment on bicuculline-induced convulsions, and analyzed a possible role of HSPs. Screw electrodes were implanted in the brain of mature male Wistar rats for electroencephalogram (EEG) recording. Experimental rats were subjected to whole-body hyperthermia at 41-42 degrees C for 15 min. Fifteen hours later, bicuculline was injected intraperitoneally to induce convulsions in both experimental and control groups. The heated rats showed a significant attenuation of the convulsive response, in terms of both spike discharges in EEG and clinical seizures. Further-more, induction of HSP72 was detected in the brain of heat-treated rats by immunoblotting, appearing at 4 h and reaching a maximal level 16-24 h after the heat shock. We conclude that the previous heat treatment stabilized neuronal excitability, most probably through the induction of HSP72.

Animals↗

PubMed1996

A comparison of isozyme and quantitative genetic variation in Pinus contorta ssp. latifolia by FST.

We employed F-statistics to analyze quantitative and isozyme variation among five populations of Pinus contorta ssp. latifolia, a wind-pollinated outcrossing conifer with wide and continuous distribution in west North America. Estimates of population differentiation (FST) for six quantitative traits were compared with the overall estimate of the differentiation (F*ST) from 19 isozymes that tested neutral to examine whether similar evolutionary processes were involved in morphological and isozyme differentiation. While the FST estimates for specific gravity, stem diameter, stem height and branch length were significantly greater than the F*ST estimate, as judged from the 95% confidence intervals by bootstrapping, the FST estimates for branch angle and branch diameter were indistinguishable from the F*ST estimate. Differentiation in stem height and stem diameter might reflect the inherent adaptation of the populations for rapid growth to escape suppression by neighboring plants during establishment and to regional differences in photoperiod, precipitation and temperature. In contrast, divergences in wood specific gravity and branch length might be correlated responses to population differentiation in stem growth. Possible bias in the estimation of FST due to Hardy-Weinberg disequilibrium (FIS not equal to 0), linkage disequilibrium, maternal effects and nonadditive genetic effects was discussed with special reference to P. contorta ssp. latifolia.

Genetic Variation↗

PubMed1996

The early evaluation of induced osteoarthritis in rats with 99Tcm-pertechnetate scans.

Osteoarthritis was induced in 30 adult rats by serial injection of papain (3.5 mg kg-1) into the right knee on days 1, 4 and 7 of the study, with equal volumes of normal saline being injected into the left knee as a control. The severity of the induced arthritis was observed after the subcutaneous injection of 37 MBq kg-1 (1 mCi kg-1) 99Tcm-pertechnetate in the neck 24 h and 1, 2, 4, 6 and 8 weeks after the first intra-articular injection of papain. The ratio of radioactivity in the right compared with the left knee of each rat was measured as an index of the severity of osteoarthritis. After the scans, X-rays of both knees were obtained. At each state of progression, a rat was sacrificed and bilateral knee sections were performed for further pathological evaluation. The results were then compared with the changes in the radioactivity ratio and the X-rays. The radioactivity ratio of the knees reached a peak approximately 25 min after the subcutaneous injection of 99Tcm-pertechnetate and this value was chosen as the index of the severity of osteoarthritis. Marked differences in radioactivity in the left and right knees were observed as early as 24 h after the first intra-articular injection of papain. The radioactivity ratio increased with time, which correlated well with pathological changes. Joint space narrowing was not found on X-ray until 4 weeks post-injection. The results showed that the 99Tcm-pertechnetate scans correlated well with the pathological changes and that this method can detect osteoarthritis earlier than joint X-rays. It is suggested that a 99Tcm-pertechnetate scan is a useful means of evaluating early changes in induced osteoarthritis in rats.

Animals↗

PubMed1996

I-cell disease: report of a case.

I-cell disease, or mucolipidosis type II (ML II), resembles Hurler syndrome but without the mucopolysacchariduria. I-cell disease is a slowly progressive disorder with onset at birth and fatal outcome in childhood. The neonate with I-cell disease usually has a low birth weight. Unlike Hurler syndrome, there is no temporary acceleration of skeletal growth around one year of age. Instead, clinical characteristics included coarse face and skin, skeletal abnormalities, gum hypertrophy, and severe psychomotor retardation. Head size is proportional to stature. Psychomotor retardation is extreme in some patients but rather mild in others. The most frequent causes of death are bronchopneumonia and congestive heart failure. We report a 9 month-old male infant with characteristic clinical features of I-cell disease. Cytoplasmic inclusions were observed in cultured skin fibroblasts. Ultrastructural study of normal looking skin revealed numerous cytoplasmic inclusions with pleomorphic contents in the fibroblasts and Schwann cells. The diagnosis was confirmed by lysosomal enzyme assay in serum and fibroblasts.

Clinical Enzyme Tests↗

PubMed1996

Analysis of cellular proteins in achondroplasia by two-dimensional electrophoresis.

An abnormal protein pattern was found in cultured fibroblasts from three of seven patients with achondroplasia. All three patients showed two abnormal protein spots which were not detected in any of the normal and pathological cell strains examined in this study. Clinical manifestations of these three cases were compared with those of other cases, but no differences were identified between them from the data available at present. The significance of these protein spots were discussed.

Achondroplasia↗

PubMed1996

Preliminary results of triple therapy for obesity.

OBJECTIVE: To evaluate the effectiveness of triple therapy in treatment of simple obesity. SUBJECTS: Forty-five cases of simple obesity with a body mass index (BMI) above 30 kg/m2 and percentage of body fat more than 25% in males, and 30% in females were collected. Subjects were composed of 8 males and 37 females ranging in age from 16 to 70 years old with a mean age of 33.8 years. METHODS: The triple therapy for obesity included weekly auricular acupuncture, diet control and aerobic exercise counseling for eight weeks. The reduction in body weight and body fat were measured upon just completing the therapeutic course. The changes of body weight in follow-up at one month and one year later were also analyzed respectively. RESULTS: The results showed a 4.4 +/- 2.9 kg reduction in body weight and a 5.6 +/- 3.0% reduction in body fat after completing the treatment course. Five cases had their body weight reduced to within the normal range, 18 cases showed a marked effect (body weight reduced by more than 5 kg and body fat reduced more than 5%), 16 cases were considered effective (body weight reduced by 2-5 kg and body fat reduced by 1-5%), and 6 cases were considered to be ineffective (body weight reduced by less than 2 kg and body fat reduced by less than 1%). The rate of effectiveness was 86.7%. The rate of body weight rebound (weight regained more than 1.5 kg) was 6.7% and 18.9% one month and one year later, respectively. The effectiveness of weight reduction was significant correlated with the compliance of participants with each therapeutic method, but not with age. No special side effects were noted during or after the treatment except for two cases who had intolerable pain when receiving auricular acupuncture. CONCLUSION: The triple therapy resulted in a satisfactory body weight reduction and a good maintenance of the target weight after treatment. Furthermore, more frequent aerobic exercise during the treatment course contributed greatly to body weight reduction and maintenance, as indicated by the correlation analysis.

Acupuncture Therapy↗

PubMed1995

Synthesis of Hsp72 induced by exercise in high temperature.

An investigation was undertaken involving the physiological effects of exercise in high temperature and its effect on the induction of heat shock proteins synthesis in peripheral lymphocytes and gastrocnemius. Male Long-Evans rats were employed. Environmental temperature was designed as three conditions: room temperature (26-27 degrees C), middle temperature (30-31 degrees C), and high temperature (36-37 degrees C). Rats were divided into one of three groups and exercised passively in an automatic round treadmill. Body temperature, biochemical changes were determined and the synthesis of heat shock protein 72 were analyzed by SDS-PAGE and immunochemical stain with monoclonal anti-Hsp72 antibody. Those results indicated that the body temperature elevated faster and higher in rats of high-temperature exercise group than those of a house temperature significantly (p < 0.05). Hsp72 could be detected only in lymphocytes from rats exercising in high temperature more than 60 minutes whose body temperatures were elevated above 41 degrees C. The induced Hsp72 appeared in lymphocytes 2 hours after exercise and reached maximally at 16-24 hours and then disappeared gradually. In gastrocnemius, Hsp72 could be detected even before the passive exercise, and its amount changed as in lymphocytes did in all three groups. No difference was found in blood sugar, hematocrit and CK among the three groups of rats. On the basis of above results, we can conclude that Hsp72 is synthesized in the muscle of intact rats, and exercise is a sufficient inducer. For lymphocytes, the presence of Hsp72 can be viewed as a heat stress in exercise.

Animals↗

PubMed1994

The effect of hyperthermic treatment on electroencephalographic recovery after interruption of respiration in rats.

Electroencephalography (EEG) was utilized for investigating the effect of hyperthermia followed by apneic hypoxia in rats. They were heated whole-bodily to 41 degrees C for 15 min under the control of an artificial rodent ventilator, after drug-induced generalized paralysis. A transcutaneous oxygen saturation monitor was applied to detect the hypoxic condition. EEG was monitored with bipolar needle electrodes. The 72-kDa heat-shock protein (HSP72) in brain was analyzed by sodium dodecyl sulfate-polyacrylamide electrophoresis, followed by immunostaining with an anti-HSP72 antibody. There was no difference in the time interval from onset of apneic hypoxia to flat EEG between the hyperthermic and control groups, but cortical electrical activity appeared earlier in the hyperthermia group than the control group, after 90 s of ventilation interruption. The cardiac function did not change in the two groups. The HSP72 synthesis significantly increased in the brain of the rats with hyperthermic treatment.

Animals↗

PubMed1994

Nucleotide divergence between populations of trembling aspen (Populus tremuloides) estimated with RAPDs.

In the present study, a total of 142 trees sampled from five populations of trembling aspen (Populus tremuloides Michx.) in Alberta was analyzed by the polymerase chain reaction (PCR) with five random oligonucleotide primers. Null-allele frequencies of 28 putative RAPD loci were estimated using the given departure from Hardy-Weinberg equilibrium (F1S) previously estimated with isozyme markers for the same population. Nucleotide divergence between populations was then estimated in a fashion similar to restriction-fragment data, but considering the dominance of the RAPDs. The average of nucleotide divergence between populations was in the order of 0.0005 and nucleotide divergence were found to be highly correlated with geographic distance. The results suggest that isolation by distance may be an important factor in the genetic differentiation of trembling aspen.

Alberta↗

PubMed1994

A dimeric hydrolysable tannin from Camellia oleifera.

Camellioferin A, a new dimeric ellagitannin, was isolated, together with 13 known tannins, including camellins A and B, from Camellia oleifera. The structure of the new tannin elucidated by spectroscopic methods.

Circular Dichroism↗

PubMed1994

Detection of dystrophin gene deletion in Chinese Duchenne/Becker muscular dystrophy patients utilizing multiplex polymerase chain reaction.

Multiplex PCR was utilized to detect deletions at the hot spot regions of dystrophin gene. Thirty-four cases of DMD and 7 cases of BMD, based on their clinical manifestations, were examined. Eight normal male adults were included as control. Eleven DNA fragments coding the exons 1, 3, 6, 8, 13, 17, 43, 47, 50, 52 and 60 were chosen and primers were prepared with oligonucleotide synthesizer. Multiplex PCR was performed under the condition of 94 degrees C 1 minute for denaturation, 65 degrees C 3 minutes for annealing, 72 degrees C 3 minutes for extension. Thirty cycles were followed by a last cycle with 7 minutes extension. Clinically, there were no significant differences between Chinese patients and those reported in other areas except the low rate of positive family history (32%). The results from multiplex PCR showed that 15 cases (37%), 11 DMD and 4 BMD, proved to have deletions in the exons studied; 1 located at exons 6 and 8, 1 at exon 8, 1 at exons 8, 13 and 17, 1 at exons 13 and 17, 1 at exon 17, 3 at exon 43, 1 at exon 50, and 3 at exons 50 and 52, after false negatives were excluded. No difference in size or location was noticed between DMD and BMD in the sample-limited result.

Adult↗

PubMed1993

Progressive alterations of cytokeratin expressions in the process of chronic arsenism.

Recent studies of an endemic occurrence of chronic arsenism in a limited area on the southwest coast of Taiwan are focusing on its cytokeratin analysis in hopes of tracing the disease's biochemical expression. Specimens were obtained from uninvolved skin and arsenical cancers including Bowen's disease, basal cell carcinoma, and squamous cell carcinoma. In this study, we used two-dimensional polyacrylamide gel electrophoresis to analyse cytokeratin expression. Progressive alterations in cytokeratin expression were found in various skin lesions. These include an expression of K16 in the uninvolved skin; K16 and K6 in Bowen's disease; and K16, K6 and K17 in squamous cell carcinoma and basal cell carcinoma. In addition, we found that the K1 isoelectric variants shifted to more acidic forms with the complete absence of K1 in basal cell carcinoma. K16 expression in uninvolved skin indicates that it is nevertheless in a hyperproliferative status. K17 was expressed in squamous cell carcinoma and basal cell carcinoma, but not in Bowen's disease. The progressive impairment of phosphorylation of K1 and K2 in the process of chronic arsenism provides us with a suitable model for studying the biological significance of phosphorylation in intermediate filaments during chemical carcinogenesis.

Arsenic Poisoning↗

PubMed1993

[Lysosomal enzyme activity of cultured fetal cells in Chinese and its clinical application].

Lysosomal storage diseases (LSD) are caused by deficient activity of specific lysosomal enzymes. Early diagnosis and selective termination is still the trend of therapy. The purpose of this study was to establish an assay system and investigate the reference range of lysosomal enzyme activity of cultured fetal cells in the Chinese population. Seventy amniotic fluid and 9 chorionic villi samples were collected and cultured in this study. Enzyme activity assay was done by synthesized 4-Mu-binded substrates. The activity was expressed as nmol/mg protein/hour. In cultured amniotic cells, the results showed 14-138 of alpha-glucosidase, 8-133 of alpha-galactosidase, 32-470 of alpha-mannosidase, 101-1121 of alpha-fucosidase, 106-1321 of beta-galactosidase, 15-268 of beta-glucosidase, 11-279 of beta-glucuronidase, 101-1193 of Hexosaminidase A, and 886-6204 of N-acetyl-alpha-glucosaminidase. In cultured chorionic villi samples, it showed 22-335 of alpha-glucosidase, 31-230 of alpha-galactosidase, 47-250 of alpha-mannosidase, 35-218 of alpha-fucosidase, 49-934 of beta-galactosidase, 34-329, of beta-glucosidase, 57-379 of beta-glucuronidase, and 328-3412 of Hexosaminidase A. The enzyme activity was not correlated with the gestation age when sample was obtained. Furthermore, there was no statistical significance among the range of amniotic cells, chorionic villi samples, skin fibroblasts and peripheral leukocytes for each enzyme studied. It is suggested that the synthesis of lysosomal enzymes has been mature since the early fetal state, and the samples obtained as early as 8 weeks of gestation age can be used for early diagnosis of lysosomal storage diseases.

Cells, Cultured↗