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Biomedical subjects

W H Yang

Publications and source records attributed to W H Yang.

10 recordsLinked to original sources

Studies of the HLA class II alleles involved in human responses to ragweed allergens Ambrosia artemisiifolia V (Ra5S) and Ambrosia trifida V (Ra5G)

Previous studies have associated skin test sensitivity and specific IgE response to Ambrosia artemisiifolia V (Amb a V) with HLA-DR2, and to Ambrosia trifida V (Amb t V) with HLA-DRw52 haplotypes in atopic individuals. Using HLA class II typing by restriction fragment length polymorphism (RFLP) analysis with DRB, DQB and DQA DNA probes to define the HLA-D alleles, we have demonstrated the association of the DQw6 in 16 out of 16 (100%) Amb a V-responsive individuals, compared to 3 out of 18 (17%) ragweed-sensitive but Amb a V-nonresponsive individuals (p = 5.7 x 10(-6), RR greater than 75). We suggest that the DQw6 association with Amb a V sensitivity may be a reflection of an association with the DQA*0102 allele. This suggests an association of a particular HLA class II allele with an immune response to a well-characterized antigen (Amb a V). The HLA-DRw52 haplotypes in the Amb t V-sensitive individuals are not of one particular subtype. The HLA-DRw52 association with Amb t V sensitivity may reside in homologous DRB1 alleles linked on HLA-DRw52-bearing haplotypes.

Alleles

[Modern extracapsular extraction for cataract of uveitis].

Cataract of uveitis is difficult for extracapsular extraction (ECE) because of posterior synechiae. 21 cases (24 eyes) of the cataract were performed modern ECE with satisfactory results. Postoperative visual acuity was 0.1 or better in 20 eyes, and 0.5 or better in 7 eyes. The optimal time for the operation and the procedures were discussed. The authors opined that removal of the cataract could prevent recurrences in some severe refractory cases of uveitis.

Adolescent

Melkersson-Rosenthal syndrome: clinical, pathologic, and therapeutic considerations.

Melkersson-Rosenthal syndrome (MRS) has been described as a rare disease. Localized swelling (usually of the lips) with noncaseating epithelioid granuloma is necessary for diagnosis. We report 11 patients with biopsy-proven MRS. Mean age was 28 years (range 12-47 years). Mean duration of lesions was 4.4 years. Lip biopsy confirmed typical sarcoid-like granuloma. Five additional patients with typical symptoms are awaiting or refused lip biopsy. Clinically all patients presented with localized swelling of the lips. Treatment with clofazimine (100 mg 4 times weekly for 3-11 months) was associated with complete remission in 5/10 patients and clinical improvement in 3/10 patients with moderate constant swelling. Two patients (one severe and one moderate swelling) failed to respond to treatment. Rebiopsy in four patients confirmed improvement with disappearance or decreased granulomatous inflammation in 3/4. Complete spontaneous remission was also seen in three untreated patients. We conclude MRS is not uncommon, clofazimine may be effective treatment in moderate lesions and spontaneous remissions can occur.

Adolescent

Clinical evaluation of the efficacy and safety of noberastine, a new H1 antagonist, in seasonal allergic rhinitis: a placebo-controlled, dose-response study.

Noberastine (NOB), a new histamine H1 antagonist, has potent and specific peripheral antihistaminic activity. To evaluate the efficacy and safety of NOB in ragweed seasonal allergic rhinitis, 250 eligible patients were randomized to one of four parallel, double-blind treatment groups: NOB, 10, 20, and 30 mg, or placebo, each administered once daily for 3 weeks. Rescue medication was prohibited. Efficacy parameters included global response rate (percentage of responders), physician visit, patient-diary symptom scores, and onset of action. Efficacy analyses used alpha = 0.0167 (adjusted for multiple comparisons). Efficacy parameters demonstrated universal superiority of NOB therapy over placebo therapy with statistical significance achieved frequently; no statistically or clinically significant separation was demonstrated among NOB-treated groups. Global-response rates for all active-treatment groups (range, 62.7% to 71.1%) were statistically significantly greater than rates for the placebo-treated group (39.6%). Median time to first relief of symptoms was within 2 to 4 hours for NOB-treated groups versus 72 hours for the placebo-treated group. No significant abnormalities in safety parameters were ascribed to NOB treatment. Incidence and severity of adverse experiences of NOB-treated groups were comparable in incidence and severity to placebo treatment. NOB treatment did not appear to cause weight gain or sedation. Once-daily NOB, 10, 20, and 30 mg, is equally and highly effective and safe in the symptomatic management of seasonal allergic rhinitis compared to placebo.

Adolescent

Gas-forming infection of the urinary tract: an investigation of fermentation as a mechanism.

Most gas-forming infections occur in patients with diabetes. Carbon dioxide formation, resulting from fermentation of the high concentration of sugar in the urine and tissue by infecting organisms, was regarded as the key factor of gas formation in previous reports. Gas from an emphysematous infection of a polycystic kidney was analyzed to understand better the mechanisms involved in gas-forming infections of the urinary tract. The term emphysematous renal polycystic infection is proposed for this particular condition. Gas from the cysts contained 4.1% carbon dioxide, 10.5% oxygen, 67.3% nitrogen and 18.1% unknown gas. This finding is astonishingly similar to that of Wheeler in 1954 and cannot be fully explained by the sugar fermentation theory. Therefore, we propose a new hypothesis. Impaired transportation of gas produced by rapid catabolism leads to gas accumulation in the tissue, which will gradually expand and create chambers to form gas bubbles. Gas of adjacent tissues will attempt to come into equilibrium with the gas bubbles. Positive equilibrium will lead to continuous expansion of the lesion bubble. However, if the chamber is unable to withstand the increasing pressure then rupture or spontaneous drainage of the gas bubble may occur. During negative equilibrium gas in the bubble gradually simulates tissue gas with eventual shrinkage of the bubble. If the chamber is unable to sustain the pressure it collapses and the bubble disappears. However, if the chamber is capable of sustaining the pressure the bubble still may persist even when the gas content is equivalent to tissue gas. This hypothesis may lead to better understanding of emphysematous infections of the urinary tract and also may cast light on emphysematous infections of other organ systems.

Aged

[Extracapsular cataract extraction for highly myopic patients].

Extracapsular cataract extraction was performed on 54 cataract cases with high myopia. During a follow-up of 5-18 months, the corrected visual acuity was 0.1-0.2 in 18 cases (33%), 0.3-0.5 in 16 cases (30%), 0.6-0.9 in 8 cases (15%), and 1.0 or over in 7 cases (13%). The major complications included intraoperative posterior capsular tear in 3 cases, secondary glaucoma due to residual cortex in 2 cases, posterior capsular opacity in 7 cases, cystoid macular edema in 1 case, and retinal detachment in 1 case. The study indicated that ECCE was safe and desirable for highly myopic patients.

Adult

Potentially fatal hereditary angioedema: a review and case report.

Hereditary angioedema is a disease based upon a biochemical deficiency which may result in sudden and unexpected death principally from respiratory distress due to swelling of the pharyngeal tissues. Dental treatment is not an uncommon initiator of such edema. To perform dental care safely, it is necessary to understand the etiology, diagnosis, and treatment of the condition. This article presents a review of these features, and indicates via a case report how knowledge of them was essential in conducting safe, effective and efficient dental treatment.

Angioedema

Electronic fetal monitoring during labor.

Intrapartum electronic fetal monitoring tracings from 620 women monitored internally over 60 minutes were analyzed. Fetal heart rate patterns were statistically analyzed against four variables of labor: 1) the presence of meconium; 2) fetal acidosis; 3) 1-minute Apgar score; and 4) clinical correlates considered as etiologic factors in FHR decelerations. No significant etiologic correlation was found between these clinical correlates and FHR deceleration patterns. Statistically significant correlations were established between poor neonatal outcome and fetal acidosis (P less than 0.01) and the presence of meconium (P less than 0.05). No correlation was found between FHR patterns and fetal acidosis. Variable deceleration showed no significant relation to low Apgar score (less than or equal to 6). Late deceleration showed a significant correlation with depressed infants. FHR patterns are best used as an alarm system of fetal difficulty than as an absolute measure of fetal distress.

Acidosis