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Biomedical subjects

T Y Chuang

Publications and source records attributed to T Y Chuang.

At least 37 records · Page 2Linked to original sources
PubMed1999

Melanoma in Kauai, Hawaii, 1981-1990: the significance of in situ melanoma and the incidence trend.

BACKGROUND: The incidence of melanoma has often been portrayed as reaching 'epidemic' proportions. The reality of such an epidemic is, however, not clearly established due to the methods of data collection and interpretation. The population-based incidence data and incidence trend of melanoma from the Island of Kauai, Hawaii provide an illustration of this 'epidemic'. METHODS: We used medical records housed at the dermatology clinic and pathology laboratory in Kauai to: identify residents of Kauai who had their first melanoma during the years 1981-1990; and to measure the 10-year population-based incidence of melanoma. RESULTS: In Caucasians: A total of 53 Caucasian residents (29 men and 24 women), were identified with an initial episode of melanoma (MM) during the 10-year period. The average annual standardized incidence rate per 100,000 Kauai Caucasian residents was 36. Whereas the incidence of in-situ MM increased during the 10-year period, the incidence of invasive MM did not. The average patient age was 55 years. The trunk and the limbs were the most common anatomic sites of MM. In men, one third of MM occur on the back. In women, one third develop on the leg/thigh. Three patients (6%) had metastasis and eventually died of MM. Thirteen patients (25%) had other skin cancers such as basal cell carcinoma and squamous cell carcinoma at some time. In Filipinos, Japanese and Hawaiians: Three Filipinos (all women), two Japanese (one man and one woman) and one Hawaiian (man) had melanoma. The standardized incidence rates, to the U.S.A. Caucasian population, were 3.1, 0.8 and 2.1 per 100,000 residents, respectively. CONCLUSIONS: The melanoma incidence in Kauai is one of the highest rates documented in the U.S.A. However, a decreased incidence of invasive melanoma during the 10-year period was unexpected. The finding of nonmelanoma skin cancer in these patients supports a common etiology among these skin cancers.

Adolescent↗
PubMed1999

EMG power spectrum analysis of first dorsal interosseous muscle in pianists.

PURPOSE: Long-term piano training may induce potential biochemical and structural adaptations in hand intrinsic muscles or alter the motor strategy in the nervous systems. METHODS: This study investigated, by electromyography (EMG) and strain gauge, whether this pedagogical training is aerobic or anaerobic by nature. Changes in EMG power spectrum during incremental isometric muscle contractions before and after a sustained, fatiguing muscular performance were studied in the first dorsal interosseous muscle (FDI) of 13 female pianists and 15 sedentary controls. The maximal voluntary contraction (MVC) force of the FDI and the time needed to induce fatigue were also measured. RESULTS: During fatigue, the median frequency (MF) shifted toward the low frequencies in both groups. The MF of 50% and 25%MVC subsequent to fatigue were significantly lower than those before fatigue in the control group (104.0 +/- 45.5 Hz vs 116.7 +/- 41.4 Hz at 50%, P < 0.05; 114.7 +/- 43.4 Hz vs 123.3 +/- 46.7 Hz at 25%, P < 0.05). There were no significant MF changes within the pianists before and after fatigue. The root mean squares (RMS) of 50%, 25%, and 10%MVC of control subjects after fatigue were significantly higher than those before fatigue, but not in pianists. There was no difference in MF and RMS between the two groups at any level of %MVC before or after fatigue, but the pianists tended to show higher MF at each level of %MVC. Although the MVC was similar in both groups, the pianists, however, needed a much longer time to induce fatigue than controls (14.3 +/- 5.8 min vs 5.8 +/- 3.3 min, P < 0.005). CONCLUSIONS: These observations are discussed in terms of the training-induced metabolic adaptations, the changes in the strategy of motor unit recruitment, and the possibility of differences in muscle fiber composition. This study indicates that piano training should not be classified as power training, rather as endurance training. Such findings may also provide information about fine motor training for athletes and other professionals.

Adult↗
PubMed1999

Risk factors of non-melanoma skin cancer in United States veterans patients: a pilot study and review of literature.

OBJECTIVE: To identify risk factors of non-melanoma skin cancer (NMSC) in US veterans patients. BACKGROUND: There are an estimated one million new NMSC cases annually in the United States alone. While other studies with varying foci have evaluated risk factors in different subsets of the general populace, none have examined veterans as a group with potentially unique exposures and risks. METHODS: An investigation of risk factors for skin cancer through questionnaire and physical examination on 145 veteran patients with skin cancer and 59 veteran patients without a history of skin cancer was conducted. RESULTS: Parents' ethnicity, actinic keratosis on the face or other anatomic sites, solar elastosis of the neck, facial telangiectasias, age of first sunburn, and residency in Indiana were risk factors significantly associated with the development of skin cancer. Other possible risk factors included smoking and radiation therapy. CONCLUSIONS: We documented several risk factors which significantly increased the chance of developing skin cancer among veterans. These included ethnic background and solar damage of the skin among others. A review of the literature confirms these risks in the general population, but also further study is warranted to address risk factors like smoking and radiation, particularly in veterans populations. Identification of pertinent risk factors will help to identify high risk individuals, allow detection of new skin cancer at its earliest stage, and develop a profile of favorable lifestyle characteristics that reduce NMSC risk.

Age Factors↗
PubMed1999

Acute postoperative aggravation of radiculopathy as a complication of free fat transplantation in lumbar disc surgery: case report.

This case report illustrates a rare case of motor weakness caused by a free fat graft herniation. A 40-year-old woman who had undergone surgery for a herniated lumbar intervertebral disc experienced right lower leg weakness. On magnetic resonance image (MRI) a herniated free fat graft was noted. An emergent operation was performed and the herniated fat graft was removed. Postoperatively, the patient recovered well with improvement of the motor weakness. MRI is a good method for diagnosis of fat graft herniation. The mechanisms of this complication have been documented, and the size of the fat graft plays an important role. The methods for prevention of this herniation are also discussed. Although the transplantation of adipose tissue has many advantages, including the prevention of postoperative epidural fibrosis, great care is needed when applying a fat graft intra-operatively. When a postoperative neurologic deficit develops, herniation of the fat graft must be considered. An emergent operation is the treatment of choice for this particular complication.

Acute Disease↗
PubMed1999

Treatment of cerebral palsy with botulinum toxin: evaluation with gross motor function measure.

The objective of this study was to investigate the effects of botulinum toxin A (BTA) injection in reducing muscular spasticity and improving locomotor function in children with cerebral palsy. Thirty-eight children with spastic cerebral palsy who were undergoing regular physical therapy were enrolled. Twenty-eight of these received BTA injection at the hip adductors and/or gastrocnemius, while the other 10, whose parents refused the BTA treatment protocol, served as the comparison group. The main outcome measures were: improvements in the severity of spasticity, walking distance, gross motor function (as assessed with the Gross Motor Function Measure, GMFM), and gait pattern (as assessed with the Physician Rating Scale, PRS), all measured 6 and 12 weeks after the start of BTA treatment. The severity of spasticity and walking distance at baseline did not differ significantly between the two groups. However, the severity of spasticity improved markedly in the BTA group, from 2.7 to 1.5 (Modified Ashworth Scale) at the hip adductor, and from 2.9 to 1.9 at the gastrocnemius at the 6-week follow-up. The walking distance improved from 46.17 m to 55.32 m at the 6-week follow-up, and to 66.6 m at the 12-week follow-up in the BTA group. Marked improvements in the quality of several gross motor functions were also noted in the BTA group. The improvements in spasticity, walking distance, and gross motor function were significantly greater in the BTA group than in the comparison group. The improvements in gait pattern did not differ significantly between the BTA and comparison groups. The findings of this study show BTA injection to be an effective treatment for reducing spasticity and improving gross motor function in children with spastic cerebral palsy. GMFM provides objective evidence regarding functional improvement after treatment in this patient population.

Anti-Dyskinesia Agents↗
PubMed1998

Brachial plexopathy in gunshot wounds and motor vehicle accidents: comparison of electrophysiologic findings.

OBJECTIVE: To characterize the extent and degree of severity in subjects with gunshot wounds (GSWs) to the brachial plexus and to investigate the association between type of injuries and the predominant level involved. DESIGN: A cross-sectional, retrospective review of electrophysiologic data. SETTING: Electromyography laboratory of a county hospital. PATIENTS: Thirty consecutive patients with GSWs and 14 patients with traction brachial plexopathies during a 5-year period (1992 through 1996). MAIN OUTCOME MEASURES: The injury was categorized according to the level predominantly involved, and each component of the four major levels of the plexus was analyzed. The association between type of injury and predominant level involved was assessed via two-tailed chi 2 test. The mean number of elements per subject to each level involved was compared between GSW and motor vehicle accident (MVA) patients using unpaired t test. RESULTS: The type of injury (GSW vs MVA) is significantly associated with the level involved. GSWs were implicated in infraclavicular rather than supraclavicular injury. Compared with MVA, the GSW plexopathies had significant lower mean number of components involved at the root and cord levels, but higher at the terminal nerve branches of plexus. In GSWs, nearly two thirds of all components were severely injured and 60% were completely damaged. CONCLUSION: These findings demonstrate that gunshot plexopathies are characterized with multielement distribution and a mixture of lesions with or without continuity.

Accidents, Traffic↗
PubMed1998

Abnormal vagal cholinergic function and psychological behaviors in irritable bowel syndrome patients: a hospital-based Oriental study.

Irritable bowel syndrome (IBS) patients in Western countries usually manifest autonomic nerve dysfunctions and abnormal psychological behaviors. The purpose of this study was to assess whether Oriental IBS patients with predominant bowel symptoms also exhibited similar abnormalities. We enrolled 40 IBS patients from the outpatient clinic and 20 controls with normal daily bowel habit for study. The IBS patients were further divided according to their predominant bowel habit: 20 were constipation-predominant and 20 were diarrhea-predominant. Sympathetic function was evaluated by sympathetic skin response (SSR) while vagal cholinergic function was determined by measuring R-R interval variation (RRIV) in electrocardiography during rest and deep breathing. Psychological parameters were assessed by scales of the Minnesota Multiphasic Personality Inventory (MMPI) and the Hopkins Symptom Checklist (HSCL-90). IBS patients, despite their bowel habit, showed normal SSR response. RRIV during deep breathing was significantly lower in constipation-predominant IBS patients than in controls or diarrhea-predominant IBS patients (16.5+/-3.1% vs 20.5+/-4.8% and 21.5+/-4.6%, P < 0.001). IBS patients also exhibited abnormal MMPI measuring scores on depression, hysteria, paranoia, and masculinity/femininity scales. In addition, they also had more severe psychological distress in the items of HSCL-90 measurement. In conclusion, vagal dysfunction characterizes Oriental constipation-predominant IBS patients seeking medical help. Abnormal psychoneurotic profiles also exist in these IBS patients, irrespective of their bowel habits.

Attitude to Health↗
PubMed1998

Dermatoepidemiology. III. ABC principles for a critical review of the literature.

EPIDEMIOLOGY: Is the study of disease occurrence in human populations. As a science, epidemiology emphasizes descriptive and analytic observation, clinical trial, behavioral intervention, and the practical utility of diagnostic tests. "Epidemiology" is derived from the Greek epi (among), demos (people), and logos (doctrine). CLINICAL EPIDEMIOLOGY: Is the application of epidemiologic principles and methods to problems arising in clinical medicine, dermatology included. For dermatologists, understanding this discipline is as important as mastering other basic sciences, such as immunology, microbiology, and dermatopathology. The recognization of Lyme disease is a classic work of "infectious" disease epidemiology. In 1972, a disease characterized by erythema chronicum migrans and "endemic arthritis" clustered in Lyme, Connecticut. By 1975, an infectious agent was suspected to be the cause of the disease. In 1977, the tick was thought to be the vector; in 1980, the spirochete became the prime suspect and, in 1982, Borrelia burgdorferi was identified as the etiologic agent. The study of hexachlorobenzene exposure, resulting in porphyria turcica, is an example of classic "chronic" disease epidemiology. The illness began in 1955 when sporadic cases of porphyria occurred in eastern Turkey. In 1957, the first case with illness resembling congenital erythropoietic porphyria was described. In subsequent years, over 3000 patients developed "epidemic" porphyria. The cause was due to the ingestion of seed wheat which had been treated with fungicides containing 20% hexachlorobenzene. EPIDEMIOLOGIC METHODS: For research, published elsewhere as Dermatoepidemiology. I., include descriptive observational study, analytic observational study, epidemiologic experimental study and tests for sensitivity, specificity, and positive/negative predictive value. Epidemiologic principles, instead, stress the correct interpretation of data, minimization of bias, and the appreciation of natural variations in collected data.

Bias↗
PubMed1998

Effect of nerve block on sural amplitude during remote muscle contraction.

We previously reported that the median sensory nerve action potentials (SNAPs) increased in amplitude during both near (3) and remote (4) muscle contraction. The objective of the present project was to begin to study the pathway by which this occurred. The sural amplitude was measured after one min. of isometric biceps contraction and compared pre and post lidocaine nerve block in 10 healthy subjects. The baseline was defined as the least amount of current needed to elicit a minimal sural response pre contraction. This level of stimulus remained constant throughout the experiment. Results showed that the sural amplitude peaked 4 min. after muscle contraction. An 8.1 microV increase in sural amplitude from baseline was noted pre injection as 5 min. post contraction, and an increase of 13.4 microV was noted comparing pre to post injection amplitudes at the same time. Statistical analysis using two-way interaction comparing the time courses pre and post injection showed a 92% chance the responses were dissimilar Post hoc least significant difference (LSD) analyses were significant at 4 min. (p = .005) and 6 min. (p = 0.29) post contraction. In conclusion, the increase in sural amplitude after remote muscle contraction was no longer apparent after proximal sural nerve block. This suggests that the nerve itself is required in the final common pathway for the transmission of this induced signal.

Action Potentials↗
PubMed1997

Neuropsychological sequelae after treatment for medulloblastoma in childhood--the Taiwan experience.

The purpose of this study was to investigate the functional independence, intellectual performance and academic achievement of children treated for medulloblastoma at the Veterans General Hospital-Taipei. Adverse factors that it was thought would result in significant intellectual impairment were also studied. Nineteen patients with medulloblastoma located over the posterior fossa were enrolled in this study. Their mean age at tumor removal was 6.16 +/- 3.30 (range 2-14) years. Mean full intelligent quotient (FIQ) was 86.00 +/- 22.66, performance intelligent quotient (PIQ) was 85.29 +/- 21.23, and verbal intelligent quotient (VIQ) was 90.50 +/- 23.50. In 11 cases academic achievement at school was poor. Sixteen patients received radiation therapy after tumor removal. Significant negative correlations were noted between IQ and whole-brain irradiation dose (r = -0.72) and between IQ and years after radiation therapy (r = -0.63). The results indicate a need for ongoing attention and intervention to prevent, remedy or minimize deficits produced by the tumor itself and by the cancer treatment.

Achievement↗
PubMed1997

Intraoperative monitoring of skin temperature changes of hands before, during, and after endoscopic thoracic sympathectomy: using infrared thermograph and thermometer for measurement.

OBJECTIVE: To investigate the roles of the second and third thoracic spinal segments in the preganglionic sympathetic innervation of the hand, and to compare skin temperature changes between thenar and other parts of palm before, during, and after endoscopic thoracic sympathectomy. DESIGN: Twelve patients, four women and eight men, with severe palmar hyperhydrosis underwent endoscopic thoracic sympathectomy. The T3 segment was identified and dissected first, followed by T2 segment extirpation. Skin temperature changes of the hand were assessed by thermograph and thermometer simultaneously before, during, and after sympathectomy. Sympathetic skin responses were undertaken 1 day preoperatively and followed up 6 months postoperatively. SETTING: An electrophysiological laboratory and operating room in a national medical center. SUBJECTS: Twelve patients who sustained a profound degree of palmar hyperhydrosis. INTERVENTIONS: Skin temperature differences of the hands were measured by infrared thermograph and thermometer before, during, and after endoscopic thoracic sympathectomy. MAIN OUTCOME MEASURES: Group's average temperature differences, and sympathetic skin response (all or none response). RESULTS: The T2 spinal segment is thought to be the main source of sympathetic outflow to the sweat glands of the hand. The group's average temperature changes were significantly higher at the 2nd through 5th fingers' tips than at the thenar after completion of T2 extirpation (p < .005). CONCLUSIONS: Intraoperative monitoring of palmar skin temperature, as judiciously measured by infrared thermograph, yields useful information about the locations of the sympathetic segments and confirmation of their entire ablation by endoscopic thoracic sympathectomy.

Adolescent↗
PubMed1997

Diversion colitis: a cause of abdominal discomfort in spinal cord injury patients with colostomy.

Diversion colitis is thought to result from nutritional deficiencies secondary to fecal diversion. Symptoms include hemorrhagic purulent rectal discharge, abdominal pain, and tenesmus. 5-Aminosalicylic acid (5-ASA) and N-butyrate enemas have been reported to help this condition non-spinal cord injury (SCI) patients. We report the case of a 49-year-old C6 ASIA B tetraplegic man who had received colostomy because of intractable ileus 10 years earlier. He presented with a 2-week history of rectal pain and bleeding. Abdominal and rectal examination on admission were unremarkable. Colonoscopy showed a partial stricture 70cm proximally to the rectum. The colonic mucosa appeared granular and friable with evidence of linear ulceration. Histopathologic study was consistent with colitis. The patient developed fever, abdominal distention, and extensive retroperitoneal air after endoscopy, suggesting colonic perforation. He was treated with daily 5-ASA suppository and total parenteral nutrition for the presumed diagnosis of diversion colitis, and intravenous antibiotics for perforated colon. After 6 weeks of treatment with 5-ASA, the patient had decreased rectal pain and bleeding. This experience suggests that diversion colitis may be a cause of abdominal discomfort in SCI patients and that 5-ASA may be used in the management of diversion colitis.

Abdominal Pain↗
PubMed1997

Outcomes research: an overview.

During the past few years there has been significant interest in studying methods that document outcomes of medical care. Outcomes management should result in higher quality health care at lower cost. However, what does outcomes research mean and how does it apply to dermatology and specifically to the individual dermatologist? This article reviews the evolution of medical outcomes research and presents the status of the current instruments, indices, and methods.

Dermatology↗
PubMed1997

Xanthoerythrodermia perstans and alopecia mucinosa in a patient with CD-30 cutaneous T-cell lymphoma.

Xanthoerythrodermia perstans (XEP) is a distinctive variant of large-plaque parapsoriasis. Along with alopecia mucinosa and lymphomatoid papulosis, there is a strong association between large-plaque parapsoriasis and evolving cutaneous T-cell lymphoma (CTCL). In some reports, large-plaque parapsoriasis was suggested to be a precursor lesion that converted to CTCL in 10 to 30 percent of cases. We describe a patient who presented clinically with both XEP and alopecia mucinosa and was subsequently shown to have CD-30 CTCL.

Adult↗
PubMed1997

The diagnostic yield of histologic examination of seborrheic keratoses.

OBJECTIVE: To examine the diagnostic yield in submitting clinically diagnosed seborrheic keratoses for routine microscopic examination. DESIGN: Retrospective examination of preoperative and postoperative diagnoses based on information provided by the clinician on the laboratory worksheet and the subsequent histopathologic diagnosis. SETTING: A regional nonhospital-based dermatopathology laboratory with specimens submitted by physicians (dermatologists and nondermatologists) practicing in a 4-state midwestern region of the United States. PATIENT MATERIAL: A total of 5592 cutaneous pathology reports were reviewed. Specimens submitted with a preoperative clinical diagnosis of seborrheic keratosis, with or without a modifier, were examined. A comparison group with the clinical diagnosis of melanocytic nevus was reviewed. MAIN OUTCOME MEASUREMENT: Preoperative clinical diagnoses were compared with the microscopic diagnoses. RESULTS: Of 577 specimens clinically diagnosed and submitted as seborrheic keratoses, 37 (6.4%) were histologically diagnosed as malignant tumors. The rate of malignant tumors increased when clinical information suggested findings beyond the classic clinical presentation, such as irritation, or when a malignant tumor was considered in the differential diagnosis. Two lesions that histologically proved to be melanomas were in this group. Comparison of the seborrheic keratosis group with the nevus group showed that seborrheic keratoses were more likely to be malignant tumors than were melanocytic nevi. Clinically diagnosed seborrheic keratoses submitted by dermatologists were more likely than clinically diagnosed melanocytic nevi to be melanomas. CONCLUSIONS: Our data suggest that there were differences in the rate of malignant tumors between dermatologists and nondermatologists and that clinically diagnosed, surgically removed seborrheic keratoses are more likely than clinically diagnosed, surgically removed melanocytic nevi to be malignant tumors.

Clinical Protocols↗
PubMed1997

Reliability testing of the dermatology index of disease severity (DIDS). An index for staging the severity of cutaneous inflammatory disease.

OBJECTIVES: To describe a new severity of illness index for inflammatory skin disease called the Dermatology Index of Disease Severity (DIDS), and to show its preliminary use and reliability in staging disease in patients with psoriasis and dermatitis. DESIGN: Interobserver rating study using the DIDS with as many as 10 observers independently rating the same patient at a single point in time. SETTING: Ambulatory care clinics at an academic medical center with patients from various socioeconomic backgrounds. PATIENTS: Thirty-four patients with psoriasis and 15 patients with dermatitis were included in the study. MAIN OUTCOME MEASURES: The severity of illness for each patient was rated as 1 of 5 stages: 0, no evidence of clinical disease; I, limited disease; II, mild disease; III, moderate disease; and IV, severe disease. The degree of interobserver concordance was measured by the Cohen kappa statistic. RESULTS: All 5 stages were represented in the study of patients with psoriasis. The overall kappa statistic was 0.76, which is defined as substantial interobserver concordance. The use of the instrument in dermatitis showed good consensus in staging, where the kappa statistic was 0.41. CONCLUSION: We introduce an easy and efficient instrument for staging the severity of illness in inflammatory cutaneous diseases. The reliability of the DIDS is demonstrated in patients with psoriasis and in patients with dermatitis.

Adult↗
PubMed1996

Guillain-Barré syndrome: an unusual complication after snake bite.

The mortality rate of the Formosan krait bite has been reported to be 23%; death is from respiratory paralysis caused by neuromuscular junctions being blocked by bungarotoxin. This article presents the first case report of Guillain-Barré syndrome after snake envenomization. The patient presented with symmetric paresis and sensory signs in the upper and lower limbs, autonomic dysfunction, facial nerve involvement, and mild elevated cerebrospinal fluid protein at about 4 weeks after the bite. Electrodiagnostic studies revealed profound sensory and motor polyneuropathy. Repeated electrophysiologic findings confirmed nerve regeneration. The patient reached satisfactory functional outcome after a short-term intensive rehabilitation program despite severe axonal degeneration. This article also discusses the possible mechanism of immunopathogenesis of Guillain-Barré syndrome after krait bite.

Activities of Daily Living↗