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Biomedical subjects

Y C Chiang

Publications and source records attributed to Y C Chiang.

At least 91 records · Page 5Linked to original sources
PubMed1993

Primary structure and biological activity of a third gonadotropin-releasing hormone from lamprey brain.

Previous studies have led to the identification of two molecular forms of GnRH (GnRH-I and II) in the brain of the sea lamprey, Petromyzon marinus. From analysis of these two forms, the primary structure of GnRH-I and the amino acid composition of GnRH-II were determined. We have now isolated a third molecular form of GnRH (GnRH-III) from the brain of this species that is different from GnRH-I and -II. The primary structure of GnRH-III is pGlu-His-Trp-Ser-His-Asp-Trp-Lys- Pro-Gly-NH2. A synthetic decapeptide with this amino acid sequence was chromatographically identical to natural GnRH-III. Intraperitoneal injection of synthetic lamprey GnRH-III (0.1 microgram/g) produced a significant (P < 0.05) elevation of plasma progesterone (31% over basal values) in female lampreys that was comparable to that produced by the same dose of lamprey GnRH-I (36% over basal). The elevation in plasma estradiol produced by lamprey GnRH-III (244% over basal) was significantly (P < 0.05) less than the elevation produced by GnRH-I (322% over basal). We propose based on the biological activity of lamprey GnRH-III in these studies and the occurrence of this peptide during metamorphosis in lampreys, that both lamprey GnRH-I and -III are neurohormones involved in reproduction in lampreys.

Amino Acid Sequence↗
PubMed1993

Two molecular forms of gonadotropin-releasing hormone from the brain of the frog, Rana ribibunda: purification, characterization, and distribution.

The molecular forms of GnRH in amphibia have not been characterized structurally. An antiserum to mammalian GnRH that shows appreciable cross-reactivity with chicken GnRH-I ([Gln8]GnRH), chicken GnRH-II ([His5,Trp7,Tyr8]GnRH), and salmon GnRH ([Trp7, Leu8]GnRH) was used in a RIA to detect GnRH-related peptides in an extract of the brain of the European green frog, Rana ridibunda. Two peptides were purified to apparent homogeneity, and determination of their primary structures showed that they are identical to mammalian GnRH and chicken GnRH-II. Salmon GnRH and lamprey GnRH-I ([Tyr3,Leu5,Glu6,Trp7,Lys8]GnRH) were not identified in this species of frog. Immunocytochemical analysis using specific antisera has identified regions of the frog diencephalon and telencephalon in which chicken GnRH-II and mammalian GnRH are localized to different populations of neurons. This differential distribution suggests distinct physiological roles for the two forms of GnRH in amphibia.

Animals↗
PubMed1993

Repository dexamethasone in the treatment of acute bronchial asthma.

Fifty-two patients with acute asthma requiring immediate therapy but not hospitalization were studied in an emergency department following conventional therapy with bronchodilators. After discharge, the patients were treated with a controlled regimen of long-acting theophylline and beta-agonist inhalation as necessary. They were randomly assigned to one of three groups using a double blind model. Group A received intramuscular and oral placebos. Group B received intramuscular dexamethasone injection along with oral placebo treatment. Group C received oral dexamethasone by a tapering schedule associated with placebo intramuscular injection. Follow-up was carried out 7 days after the treatment in the emergency room. There were no significant statistical differences in the relapse rate among the three groups. Those patients who received oral or intramuscular dexamethasone had a decrease in the need for beta-agonist inhalation and fewer respiratory symptoms. However, there was no significant statistical difference between groups B and C. It was concluded that repository steroids could reduce the respiratory symptoms and frequency of beta-agonist usage as effectively as oral steroid treatment. However, the steroids do not improve the relapse rate in patients with only mild symptoms.

Acute Disease↗
PubMed1992

Acute renal failure and severe thrombocytopenia induced by rifampicin: report of a case.

We report on a patient who developed life-threatening thrombocytopenia and acute renal failure after the reinstitution of rifampicin therapy for pulmonary tuberculosis. This combined reaction is rarely reported. Supportive treatment and withdrawal of rifampicin led to complete recovery. The increased incidence of drug-resistant tuberculosis and the need for the reintroduction of rifampicin therapy may lead to more such reactions being observed.

Acute Kidney Injury↗
PubMed1992

Broncholithiasis: a neglected bronchial disease in this country. Illustration of three cases.

A broncholith is a calcified lymph node which partially or completely erodes into the bronchial lumen. Its manifestations are non-specific and may result in life-threatening complications. In Taiwan, pulmonary tuberculosis, one of the most common etiologies of broncholithiasis, is common. To our knowledge, no report on broncholithiasis can be found in literature in this country. We herein present three cases of broncholithiasis experienced in the past 11 years in Chang Gung Memorial Hospital. The presenting manifestations are obstructive pneumonia in two cases, and hemoptysis in the other one. In two of them, the broncholiths were located in the right side. Fiberoptic bronchoscopy was performed, and the stones were visible in all of them. Bronchoscopic removal of stone was successful in two cases, and the other coughed up stones spontaneously after bronchoscopies. In the absence of significant symptoms or complications, only observation is necessary. For the symptomatic borncholiths, we advocate that bronchoscopic removal is worth trying to eliminate the necessity of thoracotomy unless complications are present, which indicate surgical intervention such as massive hemoptysis, fistula formation between tracheobronchial trees and esophagus or vessels, recurrent pulmonary infection or suspicion of malignancy.

Adult↗
PubMed1991

Pneumonia preceding respiratory failure. A rare, easily misleading clinical manifestation in adult Arnold-Chiari malformation.

A 47-year-old woman was admitted for bilateral lower lobe pneumonia with respiratory distress. Two episodes of respiratory failure developed despite improvement of pneumonia after antibiotic chemotherapy. Loss of consciousness and quadriplegia accompanied the last episode of respiratory failure. Arnold-Chiari malformation type 1 was diagnosed and a suboccipital craniectomy was performed. The neuromuscular and respiratory disorders greatly improved after operation. We believe that ACM 1 should be considered when an adult develops unexpected respiratory failure after improvement of the primary pulmonary condition. This disease is potentially treatable by surgical management, and if it is misdiagnosed, will be fatal.

Arnold-Chiari Malformation↗
PubMed1991

Trichotillomania: a clinical study of 36 patients.

To understand the clinical characteristics of trichotillomania, 36 patients were investigated at the psychocutaneous special clinic from February 1982 to October 1990. There were 16 males and 20 females. The most prominent age was found in a group of 23 (63.9%) elementary school children, and in regards to the age of disease onset, 35 (97.2%) of our patients were under the age of 18. A 30-year-old woman with schizophrenia and a 6-year-old boy with mental retardation were noted in our study; the remaining 34 patients were generally well without signs of mental illness except for the recurrent failure to resist impulses to pull out their own hair. The common life events precipitating stress were academic problems and parent-child conflicts. The duration of follow-up was for at least 6 months. The habit of hair plucking was easily corrected if the duration of the disease was less than 6 months. Usually these patients had a satisfactory regrowth of hair within 1-3 months after our explanation and reassurance. In contrast, the patients with a hair loss of more than half a year were not easy to approach, and needed psychiatric treatment.

Adolescent↗
PubMed1991

Thoracic actinomycosis--review of 9 cases.

Nine cases of thoracic actinomycosis treated in the period from 1976 to 1990 were reviewed. Among them, 4 cases were children. The clinical symptoms and laboratory examinations were non-specific. Chest roentgenographic manifestations including nodular (3 cases), infiltrations (4 cases), and infiltrations with pleural changes (2 cases) were also non-specific. Chest wall masses were noted in four patients. There were no cases correctly diagnosed on admission. The diagnosis of thoracic actinomycosis was made from thoracotomy in 6 cases, from culture of chest wall mass incisional specimens in 2 cases and from bronchoscopic biopsy in 1. All the patients received antibiotics, however the varied duration of postoperative antibiotics did not change the outcome. No mortality or recurrence was noted in our 9 patients with a mean follow-up of 1.9 years (from 2 months to 6 years.) We conclude that surgical intervention is still the cardinal method for diagnosis and treatment. Establishment of the role of postoperative antibiotics will need further prospective study. The prognosis of thoracic actinomycosis is fairly good.

Actinomycosis↗
PubMed1991

Mycoplasma pneumoniae pneumonia: clinical analysis of 45 cases.

Mycoplasma pneumoniae (M. Pneumoniae) is a primarily pathogen of the respiratory tract. The clinical characteristics, laboratory findings, and roentgenographic patterns of 45 patients with serologically proven M. pneumoniae pneumonia admitted to Chang Gung Hospital from 1981 to 1989 have been reviewed. There were 23 males and 22 females. Forty-one (91%) were below 40 years old and 13 patients (29%) were below 5 years old. Fever, cough and chest rales were the most common symptoms and signs. A transient mild elevation of liver enzymes was seen in 33% of the patients, most of whom were below the age of ten (73%). A leukocyte count over 15,000/cu mm was not rare (16%). Roentgenographic features included unilateral infiltration (84%), lower lobe predominance (60%), and either confluent (56%) or patchy (33%) consolidation. Pleural effusion occurred in 24% of the patients. Complete resolution of chest roentgenography took from 8 to 42 days with a mean of 20 days. The response of fever to treatment with erythromycin took from 1 to 6 days with a mean of 3 days. There were no life threatening pulmonic or extrapulmonic complications.

Adolescent↗
PubMed1989

The role of fiberoptic bronchoscopy in patients with hemoptysis and a normal chest roentgenogram.

We reviewed the charts of 478 patients who had fiberoptic bronchoscopy (FOB) performed for evaluating hemoptysis with a normal chest roentgenogram. FOB provided a definite diagnosis of endobronchial lesion in only 10 patients (2.1%): bronchogenic carcinoma in 2 patients, bronchial adenoma in 1 patient, tracheal cancer in 1 patient, foreign body in 3 patients and endobronchial tuberculosis in 3 patients. FOB neither visualized tumor mass nor localized the bleeding site in 300 (95.8%) of 313 patients with mild hemoptysis. However, the bleeding site could be localized by FOB in 56% of the patients (n = 165) if the bleeding amount exceeded 60 ml/day. In conclusion, in patients with hemoptysis and normal chest roentgenograms, routine FOB may not rule out airway malignancy. In contrast, it is a good diagnostic tool for localizing the bleeding site if patients present with moderate amount of hemoptysis.

Adolescent↗
PubMed1989

Pleural mesothelioma--analysis of 12 cases in Chang-Gung Memorial Hospital.

Twelve cases of pathologically proved pleural mesothelioma collected from 1983 to 1987 were analyzed retrospectively. There were 9 males, and 3 females, aged 14-76 year-old (mean 54 year-old). Eight cases were malignant mesothelioma. Four cases were benign mesothelioma. The male to female ratio in malignant tumor was 1 to 7; in benign tumor it was 1 to 1. The mean age in malignant mesothelioma was 45 year-old, and in benign mesothelioma it was 58. Of the 8 cases with malignant mesothelioma, there were 2 cases (25%) of fibrous type, 1 case (12.5%) of epithelial type, and 5 cases (62.5%) of mixed type. Asbestos exposure history was not evident in our series. Definitive diagnosis was obtained in 10 cases by thoracotomy (83%). Two cases of malignant mesothelioma were verified by pleural biopsy. The diagnostic yield is 40% for pleural biopsy, and 100% for thoracotomy. Bronchoscopic examination, percutaneous biopsy, and pleural effusion analysis were useless in making a definitive diagnosis and distinguishing from metastatic adenocarcinoma in our opinions.

Adenocarcinoma↗
PubMed1989

Use of fiberoptic bronchoscopy to retrieve bronchial foreign bodies in adults.

The flexible fiberoptic bronchoscope was used to treat bronchial foreign bodies in 33 adults. The length of time that the foreign body was in the lung was less than 1 wk in six (acute group), more than 1 month in 21 (chronic group), and uncertain in two (uncertain group), and the foreign body was an endogenous broncholith in four patients (broncholith group). The foreign bodies were nonfragile, solid matter in most cases and they frequently had sharp projections on them. Granulations around the foreign body were common in the chronic group, but there was no correlation between the length of time the foreign body was in the lung and the amount of granulation or the number of the bronchoscopies needed for diagnosis or management. The granulations did not bleed easily on biopsy or during removal of the foreign body. In fact, they receded if several pieces were removed, making the foreign body much easier to recognize and to retrieve in the next bronchoscopy (about 1 wk later). After removal of the foreign body, the residual granulations regressed, and the bronchial lumen became more patent. The mortality, morbidity, and complication rates were very low, whereas the success rate was high. We conclude that flexible fiberoptic bronchoscopy is practical and safe in retrieving bronchial foreign bodies in adult patients.

Adult↗
PubMed1989

Airway lesions presenting with a normal chest X-ray.

From August 1980 to December 1987, 2,020 patients were proved by bronchoscopy to have endobronchial lesions at Chang Gung Memorial Hospital, Taipei. The chest roentgenograms, reviewed by 2 thoracic physicians and 1 radiologist, were reported to be normal in 31 of these patients. The incidence of airway lesions with a normal chest X-ray was 1.5% (31 out of 2,020 cases). These 31 patients included 18 males and 13 females, and their ages ranged from 7 months to 75 years with a mean of 40.3 years. The leading diseases in these cases were tracheal cancer (8 cases), tracheal and/or bronchial tuberculosis (6 cases), bronchogenic carcinoma (5 cases), tracheal schwannoma (2 cases), tracheal cyst (1 case) and bronchial adenoma (1 case). The trachea and main bronchi were the two most frequent sites of radiologically occult endobronchial lesions. Although the majority of the lesions occupied more than 50% of the diameter of the airway lumen, they were not well demonstrated in the routine chest radiological studies. Location, size and nature of the lesions were the major consideration that contributed to the normal-looking appearance of the chest X-ray. Alertness to the symptoms, physical signs and clinical history led to further investigation and the final diagnosis. The conclusion is that some airway lesions may present with a normal chest X-ray and delay the diagnosis. Careful history taking and observation of clinical symptoms and signs are important in the final diagnosis of these patients.

Adult↗