Biomedical subjects

Yi-Ching Chen

Publications and source records attributed to Yi-Ching Chen.

11 recordsLinked to original sources

PubMed2006

Contrast of directional influence upon motor overflow between submaximal and maximal static exertions.

This study investigated exertion-dependent motor overflow among healthy adults when they performed isometric tasks with contralateral joints in different task directions. Twenty healthy adults (10 males and 10 females, mean age = 26.2 yrs) were instructed to complete a set of isometric contractions of various force vectors with the shoulder, elbow, and wrist joints, in a total of ten motor tasks at submaximal and maximal intensities (50%, 100% maximal voluntary contractions). The electromyographical activities from eight muscles of the unexercised upper limb were recorded to characterize intensity of motor overflow during sustained isometric contraction. Both occurrence frequency and magnitude of motor overflow in terms of standardized net excitation (SNE) increased with exertion level for all joint movements (P < 0.001). Additionally, the motor overflow magnitude depended strongly on the task direction of maximal isometric contraction (P < 0.05). Motor overflow was particularly augmented by the contralateral isometric contractions where task directions were opposed to gravity. However, such a directional effect upon SNE was not evident during submaximal contraction (P > 0.05). The difference of the net excitation between maximal and submaximal contraction (DNE(100%-50%MVC) data) indicated that the pectoralis major and triceps brachii consistently exhibited a marked recruitment in reaction to change in task direction of isometric contraction. Patterned motor overflow may be physiologically relevant to topological mapping of the ipsilateral pathways and altered effectiveness of use-dependent interhemispherical connectivity. The current observations provide better insight into gain in muscle strength due to contralateral exercise.

Adult↗

PubMed2005

Electromyographic analysis of joint-dependent global synkinesis in the upper limb of healthy adults: laterality of intensity and symmetry of spatial representation.

The intensity and spatial representation of electromyographical (EMG) activity were examined to characterize the effects of limb dominance and movement direction upon global synkinesis (GS). Twenty-two healthy young subjects (11 men, 11 women) with a mean age of 24.7 years participated in this study. Three trials of EMG activities from eight primary muscles in the unexercised limb were recorded when a maximal isometric contraction in various directions was performed by the shoulder, elbow, and wrist of the dominant and non-dominant upper limbs. The features of GS, including intensity and spatial representation, were quantified with standardized net excitation levels (SNE) and relative excitation (RE), respectively. Our data indicated that (1) GS intensity was strongly limb-dependent with a larger SNE level arising when target joints of the non-dominant upper limb were active, (2) the GS intensity was more influenced by movement direction of the non-dominant limb than by that of the dominant limb, (3) the gradient change in GS intensity was observed bilaterally with a larger SNE level associated with contralateral movements of a proximal joint than a distal joint, and (4) GS spatial representations of the upper limbs were patterned and symmetrical, but seemly insensitive to movement direction. Laterality in GS intensity and structured GS spatial representation with symmetry could be a consequence of use-dependent hemispheric organization.

Adult↗

PubMed2005

What affects the occurrence of nocturia more: menopause or age?

OBJECTIVES: Prevalence studies show that nocturia is a very common condition, affecting older age groups in particular. In this study, we evaluate (1) the community-based prevalence of nocturia and its associated overactive bladder according to the patient's perception and disturbance to sleep and (2) whether age or menopausal (MP) transition has a greater effect on the occurrence of nocturia. METHODS: The questions regarding nocturia were part of the Bristol female lower urinary tract symptoms questionnaire (translated into Mandarin, the correlation coefficient r = 0.91). A total of 1253 (79.1% response rate) women were randomly sampled from a community-based female population, aged 20 years or older. Samples were subdivided into reproductive age, perimenopausal stage and elderly. If the participants reported having nocturia, they were further questioned with, "Does it interfere with your sleep or bother your daily life?" The chi-square test and the Cochran-Armitage trend test were used to analyze the data. RESULTS: Nocturia in older age groups was significantly higher than that of the younger age groups. The occurrence of nocturia was significantly associated with the elderly (compared with the reproductive age, P < 0.05). There were no significant differences in the prevalence of nocturia between the perimenopausal stage and the reproductive age (P > 0.05). CONCLUSIONS: Our data implies that the increasing occurrence of nocturia is age-related and is not affected by the transition from pre- to postmenopause. Large-scale prospective longitudinal studies need to be conducted to clarify the effects of the aging process and estrogen deficiency.

Adult↗

PubMed2005

Multilocus DNA sequence comparisons rapidly identify pathogenic molds.

The increasing incidence of opportunistic fungal infections necessitates rapid and accurate identification of the associated fungi to facilitate optimal patient treatment. Traditional phenotype-based identification methods utilized in clinical laboratories rely on the production and recognition of reproductive structures, making identification difficult or impossible when these structures are not observed. We hypothesized that DNA sequence analysis of multiple loci is useful for rapidly identifying medically important molds. Our study included the analysis of the D1/D2 hypervariable region of the 28S ribosomal gene and the internal transcribed spacer (ITS) regions 1 and 2 of the rRNA operon. Two hundred one strains, including 143 clinical isolates and 58 reference and type strains, representing 43 recognized species and one possible new species, were examined. We generated a phenotypically validated database of 118 diagnostic alleles. DNA length polymorphisms detected among ITS1 and ITS2 PCR products can differentiate 20 of 33 species of molds tested, and ITS DNA sequence analysis permits identification of all species tested. For 42 of 44 species tested, conspecific strains displayed >99% sequence identity at ITS1 and ITS2; sequevars were detected in two species. For all 44 species, identifications by genotypic and traditional phenotypic methods were 100% concordant. Because dendrograms based on ITS sequence analysis are similar in topology to 28S-based trees, we conclude that ITS sequences provide phylogenetically valid information and can be utilized to identify clinically important molds. Additionally, this phenotypically validated database of ITS sequences will be useful for identifying new species of pathogenic molds.

DNA, Fungal↗

PubMed2005

Electromyographic analyses of global synkinesis in the paretic upper limb after stroke.

BACKGROUND AND PURPOSE: Global synkinesis (GS), or motor irradiation, is an involuntary movement associated with the coactivation of numerous muscles in one limb when the opposite limb is active. The electromyographic (EMG) patterns of people with stroke and people who were healthy were analyzed to characterize GS development in relation to joint involvement and to attempt to relate these findings to clinical observations. SUBJECTS AND METHODS: Twenty patients with stroke, divided into 2 groups with either greater levels of irradiation (SG, n = 10) or lesser levels of irradiation (SL, n = 10), and 20 subjects in a control group were studied. A dynamometer was used to provide resistance for voluntary isometric muscle contractions of the flexor muscle groups of the shoulder, elbow, and wrist. The summated and standardized net EMG amplitudes of 8 principal muscles of the unexercised (paretic) upper extremity were used to characterize intensity and spatial representation of GS. Clinical measurements included the Fugl-Meyer Assessment Scale (FMA), Barthel Index of Activities of Daily Living (BI), and the stage on the Brunnström Stages of Motor Recovery Scale (BR). RESULTS: In the SG and control groups, a more substantial GS intensity was associated with muscle contractions of the flexor muscles of the opposite proximal joint than was the case for contractions of the flexor muscles of the distal joint, whereas such a gradient change was absent in the SL group. The corresponding spatial patterns of GS exhibited a predominant cross-excitation over the unexercised pectoralis major and extensor carpi radialis muscles in the control group, contrary to the enhanced activation of the brachioradialis and biceps brachii muscles noted in patients with stroke. The SG group had a better FMA score and a more satisfactory BR stage than did the SL group, and the 2 neurological scores were related to GS intensity for patients with stroke, depending on joint involvement. DISCUSSION AND CONCLUSION: Intensity of GS provided an affiliation with motor deficits and a promising window for poststroke recovery mechanisms.

Adult↗

PubMed2004

Different expression of calpains in the anterior vaginal wall of women with and without uterovaginal prolapse.

OBJECTIVE: Tissue ischemia-hypoxia can activate the calpain proteolytic system. Mechanical trauma to the upper vaginal wall and pelvic floor could compromise vascular perfusion and could also result in calpain expression. The aims of this investigation were to assess the expression messenger RNA and proteins for m-calpain and micro-calpain in the vaginal walls of women with and without uterovaginal prolapse. METHODS: The anterior vaginal walls of 22 women with and without uterovaginal prolpase were evaluated using a reverse transcription polymerase chain reaction and western blotting for detecting calpain expression. RESULTS: The number of messenger RNA transcripts of m- and micro-calpain was significantly less in women with uterovaginal prolapse than in women without uterovaginal prolapse (two of 11 and zero of 11 versus eight of 11 and five of 11, P < .05). All women had m-calpain protein expression in the anterior vaginal wall. However, the concentration of m-calpain protein was less, but not significantly different, in women with uterovaginal prolapse than in the women without uterovaginal prolapse (0.386 +/- 0.018 versus 0.439 +/- 0.011 optical density/mm2, P > .05). None of the women with uterovaginal prolapse had expression of micro-calpain mRNA or protein (zero of 11). Expression of protein of calpains in the anterior vaginal wall is not consistent with mRNA transcripts. CONCLUSION: Calpain expression may be compromised in the anterior vaginal wall of women with uterovaginal prolapse who have abnormal histologic changes in the vaginal connective tissues or have anterior vaginal laxity.

Adult↗

PubMed2004

Characterization of a novel group of mycobacteria and proposal of Mycobacterium sherrisii sp. nov.

We describe here the characterization of five isolates of Mycobacterium simiae-like organisms representing a novel group based on whole-cell fatty acid analysis and genotypic evaluation. Two of the five isolates in this study, W55 and W58, were previously considered to belong to M. simiae serotype 2. Analysis of cellular fatty acids by gas-liquid chromatography indicated a close clustering of this group, which was well differentiated from the other M. simiae-like species. Molecular characterization was performed by nucleic acid sequencing of the small subunit rRNA gene and the gene encoding the 65-kDa heat shock protein and genomic DNA hybridization. Sequence analysis of the entire 16S rRNA gene showed a unique sequence most closely related to those of M. triplex and M. simiae. The hsp65 partial gene sequence was identical for the five isolates, with 97% identity to the M. simiae type strain. However, qualitative whole genomic DNA hybridization analysis confirmed that this group is genetically distinct from M. simiae and M. triplex. Antimicrobial susceptibilities for this group resemble those of M. simiae and M. lentiflavum. We conclude that this group represents a unique Mycobacterium species for which we propose the name Mycobacterium sherrisii sp. nov.

Base Sequence↗

PubMed2003

Prevalence and correlation of urinary incontinence and overactive bladder in Taiwanese women.

AIMS: We randomly sampled a community-based, healthy population to evaluate the prevalence and correlation of urinary incontinence and overactive bladder. We also assessed the influences of these conditions on quality of life and associated risk factors. METHODS: Of the 1,581 women sampled (2.92% of registered female residents aged 20 years and older), 1,253 (79.1%) women were successfully interviewed by using the Bristol Female Urinary Tract Symptoms Questionnaire (r=0.87, P<0.05) and the Questionnaire of Impact index regarding the impact on quality of life (r=0.91, P<0.05). RESULTS: A total of 53.7% of the women sampled suffered from urinary incontinence and related symptoms. The prevalence of stress urinary incontinence, overactive bladder, and mixed incontinence, mutually exclusive of each, was 18.0%, 18.6%, and 17.1%, respectively, from the patients' perceptions. Judging by the criteria of the International Continence Society, the prevalence of the above three conditions was 4.3%, 2.4%, and 1.8%, respectively. Of the women who perceived storage symptoms, 21.1% experienced frequency, 12.6% had urgency, 25.5% had nocturia, and 9.1% had urge incontinence. The occurrence of stress urinary incontinence increased with age up to 65 years old (25% in 50-65-year-old cohort), and the number of overactive bladder conditions significantly increased in the elderly women (over 65 years old, 39.3%). Approximately two thirds of the incontinent women had restricted their social activities (due to worrying about wetting or leakage and no toilet facilities available), and approximately 19% of the incontinent women had an affected sexual life. However, only 27.1% of the women with urinary incontinence and related symptoms in this study had reported seeking medical services to solve these problems. CONCLUSIONS: The prevalence of urinary incontinence and overactive bladder in Taiwanese women is similar to that of Western women.

Adult↗

PubMed2003

Prevalence and correlations of anal incontinence and constipation in Taiwanese women.

Anal incontinence and constipation are not only physically and psychologically disabling symptoms but also a significant social and public health problem. The epidemiology of anal incontinence and constipation from community-bases remains largely unknown, especially in Asian women. This study is a continuation of a previous survey taken on the epidemiology of urinary incontinence and overactive bladder in Taiwanese women by using a second questionnaire (correlation coefficient for symptoms, r=0.87; P<0.05). We evaluated the prevalence and potential risk factors associated with anal incontinence and constipation in the general population. Of the 1,584 (2.92%) women sampled, 1,253 (79.1%) were successfully interviewed at home. The prevalence of fecal incontinence and flatus incontinence was 35 (2.8%) and 107 (8.6%), respectively. There were 306 (24.5%) participants who reported constipation. However, according to the current medical criteria for constipation, the prevalence of constipation was only 2.7%. The prevalence of anal incontinence did not increase after the age of 65 years (9.7%, including 3.5% of elderly women with fecal incontinence and 6.2% of elderly women with flatus incontinence). The prevalence of constipation significantly increased in the women aged 65 years and over (self-reported prevalence: 32.4%, fitted in medical criteria for constipation: 8.3%). Our results demonstrated that constipation shares some of the same risk factors, namely, symptoms of uterovaginal prolapse, prior gynecologic surgery, and overactive bladder that predispose women to the occurrence of anal incontinence. The questionnaire needs a higher discriminatory capacity, and a longitudinal study should be conducted to clarify this conflict further.

Activities of Daily Living↗

PubMed2002

Periodontal bone loss in Chinese subjects with untreated early-onset and adult periodontitis: a cross-sectional study using digital scanning radiographic image analysis.

The purpose of this investigation was to evaluate the differences in radiographic alveolar bone loss (RABL) in Taiwanese subjects with early-onset periodontitis (EOP) and adult periodontitis (AP) using the digital scanning radiographic image analysis (DSRIA). A total of 4,262 teeth from 178 individuals (96 males and 82 females) were examined for RABL due to EOP and AP. The subjects with EOP and a comparison group with AP were identified from the Periodontal Clinic population (College of Dental Medicine, Kaohsiung Medical University). The following criteria were used to classify subjects with EOP and AP during the past 20 years. The RABL of teeth were calculated using a computer system equipped with Microstation 95 software, under 10 X magnification of the radiographs. Quantity assessment of RABL using the DSRIA showed that: (1) the means of RABL of maxillary and mandibular anterior teeth in the EOP group were significant greater than those in the AP group when the two sample t-test was used. (2) The greatest values of mean RABL of affected sites in the EOP group occurred most commonly in the first molars and mandibular incisors, whereas, in the AP group, the greatest values of mean RABL of affected sites occurred most commonly in the first and second molars. (3) Molars had the greatest mean RABL followed by incisors, premolars and canines. (4) The mean RABL increased with increasing age. We conclude that the features of naturally progressing alveolar bone loss at the molar and incisor sites in untreated subjects with the EOP and AP revealed that the mean RABL in the EOP group was faster and greater than that in the AP group.

Adult↗

PubMedDate not supplied

Is the occurrence of storage and voiding dysfunction affected by menopausal transition or associated with the normal aging process?

OBJECTIVES: To evaluate whether the increasing occurrence of urinary and voiding dysfunction is independently influenced by the transition from pre- to postmenopause or by the interactive and additive effects of age-associated changes in bladder and urethral function. DESIGN: Of the 1,584 women randomly sampled from a community-based health population, 1,253 (79.1%) were successfully interviewed. The participants were asked to reply to the Bristol Female Urinary Tract Symptoms Questionnaire regarding various storage symptoms and voiding dysfunction. The chi2 test and Cochran-Armitage trend test were used for analysis. RESULTS: The prevalence of storage symptoms such as frequency, urgency, nocturia, and urge incontinence in premenopausal and menopausal groups was 18.0% versus 29.8%, 9.8% versus 20.7%, 21.2% versus 38.2%, and 6.8% versus 15.7%, respectively (all P < 0.05). In premenopausal and menopausal groups, the prevalence of hesitancy, poor stream, incomplete emptying, voiding with abdominal straining, discontinuous urine flow, and dribbling was also significantly different (17.2% v 22.9%, 17.8% v 25.7%, 12.7% v 21.9%, 4.9% v 11.6%, 16.2% v 24.5%, and 9.4% v 17.6%, respectively; all P < 0.05). However, the occurrences of various storage symptoms, namely, frequency, urgency, nocturia, and urge incontinence, as well as voiding symptoms such as incomplete emptying, discontinuous urine flow, and dribbling, were also significantly associated with the normal aging process (P < 0.05). CONCLUSIONS: Our results imply that the increasing occurrences of storage and voiding dysfunctions are not only affected by pre- and postmenopausal transition but are also closely associated with aging changes.

Adult↗