Biomedical subjects

J J Chang

Publications and source records attributed to J J Chang.

At least 37 records · Page 2Linked to original sources

PubMed1999

The skill components of a therapeutic chopsticks task and their relationship with hand function tests.

Chopsticks are the primary tools used for eating and the physical movements of control are familiar to Chinese people. Chopsticks are easy to obtain in most rehabilitative settings. Occupational therapists often guide patients to practice miscellaneous chopsticks tasks to increase hand function in any case. The objective of this study was to investigate the skill components of the therapeutic chopsticks task and their relationship with hand function tests, and to identify clinical value. Eighty normal subjects (41 males and 39 females) whose age ranged from 17 to 26 years old participated in this study. Five standard hand function tests including three dexterity tests [Minnesota Rate of Manipulation Test (MRMT), Purdue Pegboard Test, and O'Connor Tweezer Dexterity Test (OTDT)], and two strength tests (Jamar Handgrip Test, and Pinchometer Test) were chosen to measure the dexterity and strength of hands. Additionally, the Test of Chopsticks Manipulation (TCM) was designed and used to assess the chopsticks manipulation skills. Subjects were tested with all the hand function tests and TCM in a random sequence. Results of six tests were obtained for each subject. Factor analysis showed that the skill components of TCM should be categorized into the "dexterity" component. In addition, a significant relationship (p < 0.05) was only seen between TCM and OTDT, there was no significant correlation between TCM and the other hand function tests. Findings in this study are valuable in setting the rehabilitation programs for patients with dexterity problems.

Adolescent↗

PubMed1998

Prospective evaluation of systematic sextant transition zone biopsies in large prostates for cancer detection.

OBJECTIVES: A prospective evaluation was performed to define the role of systematic transition zone (TZ) biopsies in prostates larger than 50 cc. METHODS: From August 1994 to July 1997, 213 consecutive patients referred because of an abnormal digital rectal examination or prostate-specific antigen greater than 4.0 ng/mL had a calculated prostate size greater than 50 cc by transrectal ultrasound (TRUS) measurement. These patients underwent TRUS-guided sextant biopsies of the peripheral zone (PZ) and TZ. RESULTS: The median calculated prostate size was 70 cc with a TZ size of 39 cc. Fifty-five cases of carcinoma of the prostate were found, giving a 26% detection rate. The TZ biopsies detected cancer in 30 of the 55 patients (55% sensitivity) compared with the 47 patients detected by the PZ biopsies (85% sensitivity). Seven cancers (13%) were detected only by the additional TZ biopsies. TZ biopsies revealed bilateral tumors when the PZ biopsies had shown unilateral disease in 2 cases. In 6 cases the TZ biopsies showed higher Gleason grade tumors than was found in the PZ. In the 30 cases with positive TZ biopsy, concordance between the PZ and TZ biopsies occurred in 74% (133 of 180) of the sectors. The PZ biopsy detected cancer in 43 of 66 corresponding sectors that had positive TZ biopsies, giving a sensitivity of 65% and a negative predictive value of 80%. CONCLUSIONS: Routine PZ biopsies missed detecting 13% of the cancers found with the addition of sextant TZ biopsies in patients with large prostates (greater than 50 cc). In addition, 14% of the patients with cancer had upgrading or detection of bilateral tumor with the added biopsies. Routine systematic sextant TZ biopsies should be considered in patients with prostates greater than 50 cc in size.

Aged↗

PubMed1998

Consideration of conformational transitions and racemization during process development of recombinant glucagon-like peptide-1.

Physicochemical characterization of dry, excipient-free recombinant glucagon-like peptide-1 (rGLP-1) indicates the conformation and purity of the bulk peptide is dependent on the purification scheme and the in-process storage and handling. The recombinant peptide preparations were highly pure and consistent with the expected primary structure and bioactivity. However, variations in solubility were observed for preparations processed by different methods. The differences in solubility were shown to be due to conformational differences induced during purification. A processing scheme was identified to produce rGLP-1 in its native, soluble form, which exhibits FT-IR spectra, consistent with glucagon-like peptide-1 synthesized by solid-state peptide synthesis. rGLP-1 was also found to undergo base-catalyzed amino acid racemization. Racemization can impact the yield and impurity profile of bulk rGLP-1, since the peptide is exposed to alkali during its purification. A combination of enzymatic digestion using leucine aminopeptidase (which cleaves N-terminal L-amino acids >> D-amino acids) and matrix-assisted laser desorption ionization mass spectrometry was used to identify racemization as a degradation pathway. The racemization rate increased with increasing temperature and base concentration, but decreased with increasing peptide concentration. The racemized peptides were shown to be less bioactive than rGLP-1.

Chemical Precipitation↗

PubMed1998

Prospective evaluation of lateral biopsies of the peripheral zone for prostate cancer detection.

PURPOSE: We evaluate the usefulness of adding 4 lateral biopsies of the peripheral zone to the routine sextant biopsy regimen for prostate cancer. MATERIALS AND METHODS: A total of 273 consecutive patients referred for abnormal digital rectal examination and/or prostate specific antigen 4 ng./ml. or greater underwent transrectal ultrasound and systematic biopsy. Lateral biopsies of the peripheral zone taken just medial to the lateral border of the prostate were added to the routine lesion directed and systematic sextant biopsy regimen. Comparisons between positive and negative biopsy groups as well as among various biopsy schemes were performed. RESULTS: Of the patients 44% had cancer on biopsy (121 of 273). While routine sextant biopsies detected 82% of cancers, 77% (17 of 22) of missed cancers were detected on lateral biopsies. Overall, lateral biopsies detected 70% of cancers, and tended to be positive in patients with small prostates and high grade tumors. A significant correlation was found between hypoechoic lesions on transrectal ultrasound and positive lateral biopsies (Fisher's exact test p = 0.0005). Cancer was found in 74 of 147 patients with lesions on transrectal ultrasound (50%). Routine sextant biopsies detected 76% of cancers (56 of 74 patients) while lateral biopsies detected 80% (59). Of these patients 15 (20%) had positive lateral and negative sextant biopsies. Routine sextant biopsies detected 91% of cancers in 121 patients without lesions on ultrasound (43 of 47). CONCLUSIONS: The addition of lateral peripheral zone biopsies increases the sensitivity for cancer detection while nearly eliminating the need for lesion directed biopsies.

Aged↗

PubMed1997

A sequence-ready physical map of a region of 12q24.1.

We developed a sequence-ready map of a part of human chromosome 12q24.1. We utilized a number of sequence-tagged site (STS) markers from 12q24.1 to screen large insert bacterial chromosome libraries and a chromosome 12-specific cosmid library. The clones were assembled into contiguous sets (contigs) by STS-content analysis. Contigs were extended by obtaining end sequences of bacterial clones, generation of additional STSs, rescreening the libraries, and screening the additional clones for the presence of STSs. The resulting contig covers nearly 2 Mb of DNA and provides an average marker resolution of 16 kb. Based on the STS content, we developed fingerprints of a subset of clones. The STS content and fingerprint data allowed us to define a minimal tiling path of clones. These clones are being used to sequence this part of chromosome 12. This contig contains the Ataxin 2 gene, and it covers the interval harboring the gene responsible for Darier disease.

Ataxins↗

PubMed1997

Structural studies of the surface projections of Chlamydia trachomatis by electron microscopy.

Rod-like projections on the surface of Chlamydia trachomatis have been studied by a combination of computer image analysis and electron microscopy. The rods, c. 60-80 A in diameter and c. 500 A in length, were found on the surface of prokaryocells of C. trachomatis inserted in the cytoplasmic membrane through a ring-like structure in the outer membrane. The rod-like structures were found at all stages of the life cycle, even in very small elementary bodies (EBs) of C. trachomatis and in vesicles < 0.2 micron. Computer image analysis of isolated rods indicated that they comprise helically arranged subunits with a periodicity of c. 50 A. From their localisation and distribution, these structures may be related to the proliferation, or to the infectivity, of chlamydiae.

Animals↗

PubMed1997

Effects of jumping skill training on walking balance for children with mental retardation and Down's syndrome.

UNLABELLED: In the present study, we hypothesized that the enhancements obtained from the practice of jumping activity could be transferred to improve the walking balance in children with mental retardation (MR) and Down's syndrome (DS). SUBJECTS: Fourteen children with the diagnosis of MR or DS, aged 3 to 6 years, were recruited from a day care institution. They were ambulant but without jumping ability. Sixty-one non-handicapped children was used to serve as a normative comparison group. METHOD: Before the training program, the performances of walking balance, jump skills and jumping distances were assessed individually by one physical therapist. The balance sub-test in the Bruininks Oseretsky Test of Motor Proficiency (BOTMP) was administered to assess the walking balance. Motor Skill Inventory (MSI) was used to assess the qualitative levels of jumping skills. A jumping skill training lesson that included horizontal jumps and vertical jumps was designed and integrated into the educational program. The recruited children received 3 sessions of training per-week for 6 weeks. A post-training test and a follow-up test were administered to the handicapped children. RESULT: In BOTMP scores, statistical differences exited between the pre-training and post-training tests in the tested items of floor walk and beam walk. However, no significant difference was found in the items of floor stand, beam stand and floor heel-toe walk. MSI scales revealed there were significant differences between pre-training and post-training tests. There was no significant difference between the scores of post-training test and the follow-up test. DISCUSSION: The results implicated that the jumping activity might effectively evoke the automatic and dynamic postural control. Moreover, the significant improvements of the floor walk and beam walk performances might be due to the transferred effects via the practice of dynamic jumping activity. Furthermore, implications and suggestions are discussed.

Child, Preschool↗

PubMed1997

Predictors of adolescent psychopathy: oppositional and conduct-disordered symptoms.

Psychopathy is an important clinical construct in the evaluation and treatment of adolescent offenders. In this study, predictors of adolescent psychopathy are explored in 81 adolescents from a residential treatment program for dually diagnosed offenders. The number of aggressive conduct disorder symptoms and total rate (number x frequency of symptoms) of deceit/theft symptoms are predictive of adolescent psychopathy. Although age of onset for conduct disorder symptoms is associated with psychopathy, its interpretation appears to be confounded by gender and ethnicity correlates. Unexpectedly, adolescent psychopathy was only modestly associated with institutional infractions. Past research and current findings are summarized with reference to their forensic implications.

Adolescent↗

PubMed1995

Pneumoperitoneum in peritoneal dialysis patients.

There has been recent controversy regarding the clinical significance of pneumoperitoneum in patients undergoing peritoneal dialysis. The incidence of pneumoperitoneum has been estimated to be 21.2% to 33.7% in prior studies of peritoneal dialysis patients. Of the peritoneal dialysis patients with pneumoperitoneum, only a small percentage (5.9% to 14.3%) had documented visceral perforations. The controversy arises in that anywhere from 20% to 100% of peritoneal dialysis patients with pneumoperitoneum and peritonitis had visceral perforation, and 32.4% to 57.1% of chronic ambulatory peritoneal dialysis patients had asymptomatic pneumoperitoneum of unknown etiology. These disparate incidences made clinical interpretation of pneumoperitoneum difficult. In addition, prior study result disagreed as to the usefulness of the extent of pneumoperitoneum in predicting visceral perforation. We retrospectively reviewed 694 chest x-ray film and acute abdominal series reports from 1982 to 1993 in 75 peritoneal dialysis patients, with 9.3 +/- 1.3 (mean +/- SEM) x-ray films per patient. The reports were confirmed by reviewing 363 x-ray films (52%). Eight patients (10.7%) had 10 episodes of pneumoperitoneum. Six of these eight patients had asymptomatic pneumoperitoneum from a known etiology: four had undergone abdominal surgery for catheter placement the prior week and two had catheter manipulation immediately preceding the x-ray. One patient had three episodes of pneumoperitoneum: one after catheter placement and two not associated with a known etiology for pneumoperitoneum while on the cycler. One patient had a surgically confirmed colonic perforation with a large pneumoperitoneum and peritonitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

PubMed1995

Antitumor agents, 154. Cytotoxic and antimitotic flavonols from Polanisia dodecandra.

Three flavonols, 5,3'-dihydroxy-3,6,7,8,4'-pentamethoxyflavone [1], 5,4'-dihydroxy-3,6,7,8,3'-pentamethoxyflavone [2], and quercetin 3-O-beta-D-glucopyranosyl-7-O-alpha-L-rhamnopyranoside [3], were isolated from Polanisia dodecandra. Compound 1 showed remarkable cytotoxicity in vitro against panels of central nervous system cancer (SF-268, SF-539, SNB-75, U-251), non-small cell lung cancer (HOP-62, NCI-H266, NCI-H460, NCI-H522), small cell lung cancer (DMS-114), ovarian cancer (OVCAR-3, SK-OV-3), colon cancer (HCT-116), renal cancer (UO-31), a melanoma cell line (SK-MEL-5), and two leukemia cell lines (HL-60 [TB], SR), with GI50 values in the low micromolar to nanomolar concentration range. This substance also inhibited rubulin polymerization (IC50 = 0.83 +/- 0.2 microM) and the binding of radiolabeled colchicine to tubulin with 59% inhibition when present in equimolar concentrations with colchicine. Compound 2 also showed cytotoxicity against medulloblastoma (TE-671) tumor cells with an ED50 value of 0.98 microgram/ml. Compound 1 appears to be the first example of a flavonol to exhibit potent inhibition of tubulin polymerization and, therefore, warrants further investigation as an antimitotic agent.

Antineoplastic Agents↗

PubMed1995

Predictors of shoulder subluxation in stroke patients.

Shoulder subluxation has been recognized as a major and frequent complication in patients with hemiplegia. It may worsen and may be associated with shoulder and extremity pain, nerve damage, and interfere with functional activities. The overall goal of this study was to examine the significant predictors of shoulder subluxation in stroke patients and to suggest a way of early prevention and management of hemiplegic shoulder subluxation. A retrospective study was performed and backward stepwise logistic regression analysis was used to analyze the available collected data. The result showed that significant predictors of hemiplegic shoulder subluxation were Brunnstrom's arm motor stage (beta = -2.480, the Wald statistic = 10.03, p = 0.0015) and arm sensory (tactile) status (beta = 1.0283, the Wald statistic = 3.93, p = 0.0474). This study supports that sensory (tactile) impairment may be a precipitating factor for hemiplegic shoulder subluxation and it may highlight the importance of both motor and sensory preventive strategies in early prevention and management of shoulder subluxation. The preventive strategies for shoulder subluxation during the acute/flaccid phase of neural recovery are also discussed in this study.

Adult↗

PubMed1994

Acute toxic and teratogenic effects of cyclic imides in rodents.

Four structurally different cyclic imides or related derivatives (o-(N-phthalimido)acetophenone (1), 2,3-dihydrophthalazine-1,4-dione (2), N-(4-methylphenyl)diphenamide (3), and 4,6-dihydro-5H-dibenz[c,e]azepine (4) were examined for acute toxicity in mice at multiple doses, for long term toxicity at a single dose in rats, and for deleterious effects on fertility and pup development in rodents. No deleterious effects were observed when mice were administered agents at 20, 50, and 100 mg/kg/day for seven days. All other measured characteristics and values were normal for the four compounds. The principle effect of the compounds was to reduce the percent pregnancies in treated mice compared to the controls. Compound 2 afforded the greatest reduction of pregnancy (54%) at 100 mg/kg/day. Compounds 3 and 4 caused a minor reduction in pregnancy (12-20%). The compounds did not appear to cause measureable teratogenic effects; pups of treated rodents thrived and survived as well as controls. There were no effects on murine male fertility when compounds were administered at 20, 50, and 100 mg/kg/day for six weeks.

Animals↗

PubMed1994

Displacement of hepatitis B virus by hepatitis C virus as the cause of continuing chronic hepatitis.

BACKGROUND/AIMS: It has been shown that hepatitis C virus (HCV) superinfection may suppress hepatitis B virus (HBV) leading to hepatitis B surface antigen (HBsAg) clearance and that hepatitis may persist after HBsAg clearance in a few patients. The role of HCV in continuing hepatitis after termination of chronic HBsAg antigenemia remains to be explored in a series of patients. METHODS: HCV markers were studied using second generation enzyme immunoassay and polymerase chain reaction with reverse transcription and were compared between 41 patients with persistent alanine aminotransferase (ALT) elevation (hepatitis group) and 82 age/sex-matched patients with normal ALT (control group) after HBsAg clearance. RESULTS: Twenty-six (63%) of the 41 hepatitis group patients were seropositive for antibodies to HCV (anti-HCV) compared with only 4 (5%) of 82 controls (P < 0.0001). Six patients of the hepatitis group and 1 control had an episode of acute hepatitis C with seroconversion of anti-HCV 1-68 months before HBsAg clearance. Of those seropositive for anti-HCV, serum HBV DNA was not detectable, and serum HCV RNA was detected in 23 (88.5%) of the 26 hepatitis patients but none of the 4 controls (P < 0.001). Liver biopsy in 6 anti-HCV positive patients with continuing hepatitis showed features compatible with chronic hepatitis C. HCV RNA, but not HBV DNA, was detected in liver tissues of these 6 patients. CONCLUSIONS: The results suggest that HCV may usurp the role of HBV in chronic hepatitis and act as the major cause of continuing hepatitis or ALT elevation after HBV/HBsAg clearance.

Adult↗

PubMed1994

Vibrio vulnificus infection--report of 8 cases and review of cases in Taiwan.

Vibrio vulnificus infection, which is a rare and fatal disease, can be categorized clinically as either primary septicemia or wound infection. The clinical presentation of patients with primary septicemia can vary from fever alone to a more severe illness including high-grade bullous lesions, hypotension, and shock. Wound infection typically results from either injury to the skin in a marine environment or contact of a preexisting wound with sea water. We reported eight cases with Vibrio vulnificus infection in Chang gung Memorial Hospital and reviewed ten other cases previously reported with details in Taiwan. Fourteen patients presented with primary septicemia, and four with wound infection. Thirteen patients had alcoholism or chronic liver disease, two had peptic ulcer disease, one was steroids abuser, and one patient had thalassemia and chronic liver disease. Overall mortality was 55.6% (ten patients). Patients with hypotension within 48 hours of admission had higher mortality than normotensive patients (77% vs. 0%, P = 0.007). Patients with chronic liver disease or liver cirrhosis also had tendency to a higher mortality than not (64% vs. 25%, P = 0.274). Chronic liver diseases and liver cirrhosis are common disease in Taiwan. They take a high risk for Vibrio vulnificus infection. Clinician should keep in mind of this potentially fatal infection in these patients reporting a history of recent raw oyster consumption and presented with sepsis and characterized skin lesions. Prompt empirical antibiotics treatment and aggressive surgical treatment may be lifesaving for this acute and fatal disease.

Adult↗

PubMed1993

Synthesis and cytotoxicity of 1,6,7,8-substituted 2-(4'-substituted phenyl)-4-quinolones and related compounds: identification as antimitotic agents interacting with tubulin.

A series of 1,6,7,8-substituted 2-(4'-substituted phenyl)-4-quinolones and related compounds have been synthesized and evaluated as cytotoxic compounds and as antimitotic agents interacting with tubulin. The 2-phenyl-4-quinolones (22-30) with substituents (e.g. F, Cl, and OCH3) at C-6, C-7, and C-8 show, in general, potent cytotoxicity against human lung carcinoma (A-549), ileocecal carcinoma (HCT-8), melanoma (RPMI-7951), and epidermoid carcinoma of the nasopharynx (KB) and two murine leukemia lines (P-388 and L1210). Introduction of alkyl groups at N-1 or C-4 oxygen led to inactive compounds (35-43 and 50). In addition, compounds 24, 26, and 27 were evaluated in the National Cancer Institute's 60 human tumor cell line in vitro screen. These compounds demonstrated the most marked effects in the screen on two colon carcinoma cell lines (COLO-205 and KM-20L2) and on a central nervous system tumor cell line (SF-539) with compound 26 the most potent of the three agents. Compounds 24, 26, and 27 were potent inhibitors of tubulin polymerization, with activity nearly comparable to that of the potent antimitotic natural products colchicine, podophyllotoxin, and combretastatin A-4. The three agents also inhibited the binding of radiolabeled colchicine to tubulin, but this inhibition was less potent than that obtained with the natural products.

Animals↗

PubMed1993

Antitumor agents. 139. Synthesis and biological evaluation of thiocolchicine analogs 5,6-dihydro-6(S)-(acyloxy)- and 5,6-dihydro-6(S)-[(aroyloxy)methyl]-1,2,3-trimethoxy-9-(methylthio)-8H- cyclohepta[a]naphthalen-8-ones as novel cytotoxic and antimitotic agents.

A series of novel thiocolchicine analogs, 5,6-dihydro-6(S)-(acyloxy)-and 5,6-dihydro-6(S)-[(aroyloxy)-methyl]-1,2,3-trimethoxy-9-(methylthi o)-8H- cyclohepta[a]naphthalen-8-ones, possessing a six-membered ring B, have been synthesized and evaluated for their cytotoxicity against various tumor cell lines, including solid tumor cell lines, and for their interaction with tubulin. The configuration of the parent alcohol (compound 5) was established unequivocally as (aR,6S) by X-ray crystallographic analysis. The side chain at the C(6) position is in a pseudoaxial orientation. The optical properties and 1H NMR data indicated that these compounds have the same conformations in solution as in the solid state. Biological results showed that compounds (5, 6, 14, 15, 17, and 18) bearing a small side chain at C(6) demonstrate high potency in inhibiting tubulin polymerization and binding of radiolabeled colchicine to tubulin. The most cytotoxic compounds were 14, 15, 17, and 18, with good activity against several solid tumor cell lines. To explain the strong antitubulin activity of compound 5 (with an aR configured biaryl system in contrast to the aS configuration previously described for colchicinoids, allocolchicinoids, and steganacin) we speculate that a rapid atropisomerism equilibrium must exist for 5 and its active derivatives. This equilibrium would yield adequate amounts of aS-configured conformers that interact, strongly with tubulin. Since the optically inactive 18 is also a potent inhibitor of tubulin, the configuration of the side chain of these six-membered ring B analogs cannot be essential for their binding to tubulin. Instead we propose that the size of ring B and of its side chain play important roles in tubulin binding activity by affecting the rotation of the rings A and C along their linking C-C bond axis.

Animals↗

PubMed1993

Terephthalic acid in Sprague-Dawley rats as a hypolipidemic agent.

Terephthalic acid at 20 mg/kg/day in lowered serum cholesterol and triglyceride levels in rats. The cholesterol content was lowered in the lipoprotein fractions. The effects of the agents on de novo lipid synthesis showed that similar enzymes were affected in rat liver and small intestinal mucosa cells as when compared to in vitro tissue culture cells from rats and humans, e.g. reduction of acyl CoA cholesterol acyl transferase and elevation of neutral cholesterol ester hydrolase activities suggest that net cholesterol esters deposition in foam cells should be reduced and plaque growth should be slowed. The suppression of LDL receptor binding and degradation by the drug suggest that less apoB lipoproteins are taken up by peripheral tissues. The elevated HDL receptor binding and internalization in the liver suggest that the drug accelerates cholesterol return to the liver. Additional studies show that cholesterol and bile acid secretion in the bile is elevated. However, the bile acids secreted are not lithogenic. Acute toxicity studies show that the agent appears to be safe in rodents. Two observations of increased serum alkaline phosphatase levels and increased liver vacuolation suggest some alteration of hepatic cell morphology, which requires further investigation.

Animals↗

PubMed1993

The hypolipidemic effects of 2-furoic acid in Sprague-Dawley rats.

2-Furoic acid was shown to be effective in lowering both serum cholesterol and serum triglyceride levels significantly in rats with an elevation of HDL cholesterol level at 20 mg/kg/day orally. LDL receptor activity was reduced in hepatocytes, aorta foam cells, small intestinal epithelium cells and fibroblasts. HDL receptor activity was elevated in the rat hepatocytes and small intestinal cells. These activities were correlated with inhibition of acyl CoA cholesterol acyl transferase activity. Neutral cholesterol ester hydrolase activity was elevated in rat hepatocytes and human fibroblasts. Thus, 2-furoic acid appears to interfere directly with activity of intracellular enzymes rather than affecting high affinity-mediated lipoprotein membrane receptors. In vivo treatment with 2-furoic acid led to reduction in the liver and small intestine ATP dependent citrate lyase, acetyl CoA synthetase, acyl CoA cholesterol acyl transferase, sn-glycerol 3-phosphate acyl transferase, phosphatidylate phosphohydrolase and heparin induced lipoprotein lipase activities. 2-Furoic acid reduced biliary cholesterol levels but the agent increased bile salts which are lithogenic. Acute toxicity studies in mice suggest that the agent has some hepatic toxicity effects. The LD50 was relatively low at 250 mg/kg IP in mice.

Animals↗