Biomedical subjects

C H Chiang

Publications and source records attributed to C H Chiang.

At least 91 records · Page 5Linked to original sources

PubMed1992

Role of platelets in microembolism-induced acute lung injury.

The role of platelets in acute lung injury has not been well defined. In the present study of isolated perfused rat lungs, a significant increase in pulmonary arterial pressure (PAP), lung weight and the lung lavage fluid protein concentration occurred when 3 mL of a CaCl2 suspension (25 mg/mL) was mixed with blood-KHB (Krebs-Henseleit Buffer) perfusate; or when platelets were added instead of blood. However, such an increase was not observed (p > 0.05) when only KHB was used. When a comparatively small amount (0.75 mL) of the CaCl2 suspension (50 mg/mL) was added to the KHB perfusate, PAP, lung weight and the lung lavage protein concentration increased only when PAF (platelet activating factor) and platelets were both added before, but not separately. The above phenomena show that platelets are actively involved in the mechanism of acute lung injury and play an extremely important role in this microembolic model.

Acute Disease↗

PubMed1991

Mental retardation in congenital nonprogressive myopathy with uniform type 1 fibers.

A 12-year-old girl with proximal muscle weakness and delayed psychomotor development from early infancy is presented. She had a myopathic face, high-arched palate, nasal tone vocalization, positive Gowers' sign, waddling gait and decreased deep tendon reflexes. Her IQ was 40 (PIQ = 39, VIQ = 51). The serum creatine kinase level and peripheral nerve conduction velocity as well as electrocardiogram were normal. The electromyogram showed myopathic changes. Magnetic resonance imaging (MRI) of thigh muscles revealed fatty infiltration of all muscle groups, the hypertrophic biceps femoris and semimembranous muscles being spared. A biopsy specimen from the left biceps brachii muscle revealed small caliber fibers, increased variability of fiber size and uniformity of type 1 fibers (greater than 99%). This case was diagnosed as having congenital nonprogressive myopathy with uniform type 1 fibers, and had a non-deteriorating clinical course as in most congenital nonprogressive myopathy cases.

Child↗

PubMed1991

Effect of stabilization temperature on the degradation of adriamycin in albumin microspheres.

The effect of stabilization temperature on the degradation of adriamycin HCl during the preparation of albumin microspheres was investigated. The degradation of adriamycin HCl by heating at various temperature with different time interval in dried adriamycin HCl powder, adriamycin HCl aqueous solution, wetted Adriablastina (adriamycin HCl with lactose) powder and Adriablastina aqueous solution was also studied. In the presence of water the degradation of adriamycin HCl was found; whereas, in the absence of water no degradation occurred. The degradation of adriamycin HCl in solution and wetted powder showed a zero order reaction. An increase in temperature increased degradation rate. The rate constant for adriamycin HCl degradation in Adriablastina solution obtained was in good agreement with that in adriamycin HCl solution. It was suggested that the presence of lactose had no interference in the degradation of adriamycin HCl. The zero-order reaction of degradation was attributed to the drug behaved like a suspension. The degradation of adriamycin HCl at various stabilization temperature during the preparation of microspheres had the same tendency as those of the adriamycin HCl solution and the wetted adriamycin HCl powder that were heated by the DSC instrument with the condition similar to the preparation of microspheres.

Doxorubicin↗

PubMed1991

Dystrophin immunostaining of muscle from Chinese patients with various neuromuscular diseases.

The localization of dystrophin was studied using the immunohistochemical method of diagnostic muscle specimens from 68 patients, aged 9 days to 65 years, with various neuromuscular disorders. Additionally muscle specimens from 2 normal humans and 2 normal mice were used as positive controls, and those from 2 mice with x-linked muscular dystrophy as negative controls. The specimens from all 14 Duchenne muscular dystrophy (DMD) patients, including one with preclinical DMD, showed negative dystrophin staining except for two which had 0.2% to 0.8% positive fibers. The mdx mice also showed negative dystrophin staining. In Becker muscular dystrophy (BMD), muscle fibers stained in a patchy or discontinuous fashion. Two symptomatic DMD carriers exhibited a distinct mosaic pattern of dystrophin positive and negative fibers. In contrast, dystrophin was present in all 7 biopsies from patients with 4 other types of muscular dystrophy (limb-girdle, congenital, myotonic and facioscapulohumeral). Other specimens, those from normal humans and control mice, revealed homogeneous immunostaining along the surface membranes of all muscle fibers. We thus conclude that immunohistochemical dystrophin staining can aid in differentiating DMD from preclinical DMD or BMD, as well as in the detection of DMD carriers.

Adolescent↗

PubMed1991

Pleomorphic adenoma of the trachea: report of two cases.

Two unusual cases of pleomorphic adenoma (benign mixed tumor) of the trachea were found in a 56-year-old woman and a 20-year-old man. Both patients had been initially treated for presumed bronchial asthma for 5 years and 4 years, respectively. Pulmonary function tests in each showed typical extrathoracic obstruction. The diagnosis of tracheal lesions in both cases was based principally on the following: 1) dyspnea without complete remission over an extended period of time following initial examination; 2) marked retraction of the supraclavicular and suprasternal notches during inspiration with stridor on physical examination; and 3) a high degree of suspicion. Large tumors were found within the air column of the trachea by soft tissue density X-ray films and electroradiographs of the neck, CT scans of the neck and mediastinum in each patient revealed that the tumor originated from the membranous layers of the trachea in the woman and the posterolateral wall of the trachea in the man. Fiberoptic bronchoscopy confirmed the clinical diagnosis. Both cases were successfully treated by segmental resection of the trachea with end-to-end anastomosis.

Adult↗

PubMed1991

Somatostatin, substance P, prolactin and vasoactive intestinal peptide levels in serum and cerebrospinal fluid of children with seizure disorders.

Seventy patients aged from one month to 18 years with seizure disorders were classified into three groups: I. Patients who had hard control seizure attacks even under medication; II. those who had occasional seizure attacks (less than 6 times per year) and III. those who had no seizure attacks after receiving medication for at least one year. Blood samples were taken for somatostatin, substance P, prolactin and vasoactive intestinal peptide (VIP) assays. Lumbar puncture was made in 32 children and CSF samples were also assayed for neuropeptides. Somatostatin levels in serum were significantly elevated in group I and group II (P = 0.05, ANOVA) but not in group III and control group. Similar observations were made in substance P, prolactin and VIP studies. In CSF, the somatostation can better indicate the difference between epileptic and normal children (comparison with group I, P greater than 0.001; with group II, P less than 0.001; even with those who were seizure free after medication, P less than 0.05). In conclusion, the levels of several neuropeptides (somatostatin, substance P. prolactin, VIP) were elevated in children with seizure disorders both in serum and CSF. The present investigation provides a new category for the understanding of the pathogenesis, treatment as well as prognosis of seizure disorders.

Adolescent↗

PubMed1990

The study of ocular hypotensive effect of 6-hydroxyethoxy-2-benzothiazole sulfonamide: a topical carbonic anhydrase inhibitor.

A newly synthesized topical carbonic anhydrase inhibitor, 6-hydroxyethoxy-2-benzothiazole sulfonamide (6-HS), was administered systemically and topically to alpha-chymotrypsin-induced glaucoma rabbits to evaluate its ocular hypotensive effect. A significant IOP lowering effect was observed after topical application of 50 microL of 3% 6-HS gel, but a dose of 50 microL of 3% 6-HS suspension failed to reduce IOP. The maximal magnitude of reduced IOP after topical gel instillation was 24.4%, very close to the result obtained following intravenous injection of 6 mg/kg of 6-HS (23.3%). However, the blood levels of 6-HS after topical instillation with 3% 6-HS gel was much lower than that following 6 mg/kg of 6-HS injected intravenously (less than 5%). Since a lower dose of 6-HS (1 mg/Kg) administered intravenously did not cause a significant drop in IOP, it is reasonable to deduct that the ocular hypotensive effect of 6-HS applied topically can then be attributed to the inhibition of intraocular carbonic anhydrase activity. It was also noted that a larger dose of intravenous administration of 6-HS (20 mg/Kg) had a more profound IOP and blood pressure reducing effect with moderate metabolic acidosis.

Animals↗

PubMed1990

Corneal and scleral penetration studies of 6-hydroxyethoxy-2-benzothiazole sulfonamide: a topical carbonic anhydrase inhibitor.

A newly synthesized topical carbonic anhydrase inhibitor, 6-hydroxyethoxy-2-benzothiazole sulfonamide (6-HS), was used as a model drug to determine its corneal and scleral permeabilities in rabbit eyes. The corneal permeability coefficient of 6-HS for short duration glaucoma and normal rabbit eye was not significantly different (its mean value was around 2.9 x 10(-6) cm/sec), while the corneal permeability coefficient for long duration glaucoma rabbit eye was 1.8 times greater than that for the normal eye. The sclera was found to have a higher permeability than the cornea in that after four hours perfusion the amount of drug which passed through the sclera was 11 times greater than that of the cornea. In addition, it was also noted that after topical instillation of 50 microL of 3% 6-HS gel the aqueous humor concentrations of 6-HS in short duration glaucoma eye and normal eye were not statistically different.

Administration, Topical↗

PubMed1990

Correlation between cardiopulmonary changes and severity of acute lung injury in dogs.

In an attempt to determine the physiologic parameters that best correlate with severity of lung edema (wet/dry [W/D] weight), we serially monitored multiple cardiopulmonary hemodynamics, airway pressure, and blood gases on both 100% oxygen and room air after graded infusions of oleic acid (OA) in dogs. We found significant increases in the intrapulmonary shunt fraction (Qsp/Qt), mean pulmonary arterial pressure (MPAP), pulmonary (PVR) and systemic vascular resistance (SVR), alveolar-arterial PO2 difference (P[A-a] O2), and peak airway pressure (Paw), but decreases in PaO2 and pH. These cardiopulmonary hemodynamic changes were similar to those found in adult respiratory distress syndrome (ARDS). This study showed that Qsp/Qt (r = .72, p less than .001), PaO2 (r = -.60, p less than .01), P(A-a)O2 (r = .55, p less than .01), pH (r = -.55, p less than .01), MPAP (r = .50, p less than .05) and Paw (r = .49, p less than .05) significantly correlated linearly with W/D. The significant correlation is not high enough clinically to predict the severity of acute permeability pulmonary edema considering only one parameter of cardiopulmonary hemodynamic change. Therefore, we propose the possible prediction of the severity of ARDS by considering all of the above hemodynamic changes together with Paw or dynamic compliance.

Acute Disease↗

PubMed1990

The different changes of phrenic nerve activity and frequency elicited by microinjection of L-glutamic acid into ventrolateral nucleus of the tractus solitarius in cats.

There is only limited information of the neurotransmitters in central respiratory control. L-glutamic acid has been proposed as the primary neurotransmitter in the nucleus of the tractus solitarius (NTS) in cats. To test whether there is a respiratory effect of glutamic acid in the respiratory center or not, we microinjected L-glutamic acid (1 M, 0.1 microliter) via 1 microliter Hamilton microsyringe into the ventrolateral nucleus of NTS, namely dorsal respiratory group (DRG) over two-second intervals with continuous monitoring of phrenic nerve activity (PNA), frequency (f), end tidal CO2, blood pressure and heart rate. Glutamate induced various respiratory changes including: increase in PNA and f decrease in PNA and f [corrected] increase in PNA but decrease in f and decrease in PNA but increase in f. In addition to regular changes of PNA or f elicited by glutamate microinjection were found. Other patterns of irregular rhythmic changes such as absence of PNA, continuous phrenic nerve discharge and irregular phrenic nerve discharge with reflex apnea, apneusis and irregular respiration respectively were also observed. Glutamic acid appears to significantly modulate respiratory drive in DRG. We suggested that L-glutamic acid may be a neurotransmitter in the respiratory center and be involved in central respiratory control.

Animals↗

PubMed1990

Clinical observations and virological study of aseptic meningitis in the Kaohsiung area.

During 1988, an endemic outbreak of aseptic meningitis was noted in the Kaohsiung area. Throughout the year, a total of 89 cases were identified by cerebrospinal fluid (CSF) examination at the Pediatric Department of Kaohsiung Medical College. The peak incidence was from June to October. Scattered cases still occurred during November and December. The male to female ratio was 1.7:1 and the age distribution ranged from 1 month to 15 years old. Two peaks of age distribution were observed; one in infancy and the other in the 4-7 year old age group. Most of them exhibited fever (94.4%), headache (68.9%), and vomiting (68.5%). Other associated symptoms and signs included neck stiffness, sore throat, cough, Brudzinski's sign, abdominal pain, seizure, dizziness, rhinorrhea, diarrhea, Kernig's sign, skin rash, hyperemic conjunctiva, apnea, and oral ulcers. Most of them had CSF white blood cell (WBC) counts less than 1000/mm3, normal or mild elevated protein, and normal CSF/plasma sugar ratio. Three patients were found to have a virus in their CSF without pleocytosis. Virus isolations from CSF throat swabs and/or rectal swabs were performed in 65 patients, half of them (35/65, 53.8%) had positive results including echovirus type 9 (sixteen), echovirus type 30 (eighteen), and adenovirus type 3 (one). Echovirus type 9 was predominant during July and August whereas echovirus type 30 became predominant after September. All patients recovered spontaneously without any sequelae.

Adolescent↗

PubMed1990

Minimal change myopathy: report of a case.

A young boy, aged 5 years 7 months, presented with generalized hypotonia and proximal muscle weakness, and had exhibited delayed motor milestones since birth, He showed talipes planovalgus, a myopathic face, nasal tone vocalization, positive Gowers' sign and decreased tendon reflexes, but there was no intellectual impairment or seizure. The serum creatine kinase level and peripheral nerve conduction velocity, as well as the electromyogram and electrocardiogram, were within normal limits. A biopsy specimen from the left biceps brachii muscle revealed minimal nonspecific changes and mild variations in fiber size with an increased number of undifferentiated type 2C fibers, but no subcellular abnormalities were found on either the histochemical or electron microscopic examinations. The patient was diagnosed as having minimal change myopathy and improved clinically in muscle strength after one year of follow-up.

Child, Preschool↗

PubMed1990

Evaluation of vaccines designed to induce protective cellular immunity against the Plasmodium yoelii circumsporozoite protein: vaccinia, pseudorabies, and Salmonella transformed with circumsporozoite gene.

In an attempt to induce a protective cytotoxic T-cell mediated immunity against sporozoites of Plasmodium yoelii, the gene encoding the P. yoelii circumsporozoite (CS) protein was engineered into three live vectors: vaccinia, attenuated pseudorabies, and attenuated Salmonella typhimurium. Balb/c mice were immunized with 1-4 doses of 10(8) pfu of the vaccinia construct (IP), 3 doses of 10(5), 10(6) or 10(7) pfu of pseudorabies construct (IV), and 3 doses of 10(9) salmonella transformants (orally). In the case of vaccinia and pseudorabies constructs, an excellent immune response was obtained as measured by antibodies to sporozoites. No protection or delay in prepatent period was seen in any of the experimental animals when challenged with 200 (vaccinia, pseudorabies) or 100 (salmonella) sporozoites, although mice immunized with irradiation-attenuated sporozoites were consistently protected against challenge with greater than 10(4) sporozoites. Since other vaccinia, pseudorabies, and salmonella CS constructs have been shown to induce cytotoxic T lymphocytes (CTL) against the CS protein, it is likely that CTL against the CS protein were induced during these studies. It is currently unclear if the vaccines did not induce the appropriate CTL or inadequate numbers of CTL, or if CTL against the P. yoelii CS protein are inadequate to protect against sporozoite challenge.

Animals↗

PubMed1990

[Comparative study on the pharmacokinetics and bioequivalence of two brands of norfloxacin preparation].

The pharmacokinetics and bioequivalence of two norfloxacin, Gentle capsule and Baccidal tablet, were compared in eight healthy male volunteers. A 400 mg dose of norfloxacin was given orally after an overnight fasting to volunteers in a balanced two-way cross-over study. Blood samples were obtained at 0, 0.5, 1.0, 2.0, 4.0, 8.0, 12.0 and 24.0 hours after the dosing. Norfloxacin concentration in serum was assayed by a high pressure liquid chromatographic method using an UV detector. All the data was processed by KMCP computer software and the pharmacokinetic parameters were calculated, based on one-compartment model. The results revealed that the maximal concentration (Cmax) of Gentle and Baccidal was 0.96 +/- 0.089 and 0.99 +/- 0.110; the time to reach maximal concentration (Tmax) was 2.0 +/- 0.0 for both; the elimination constant (Kel) was 0.101 +/- 0.006 and 0.098 +/- 0.005 hr-1; the elimination half life (T1/2, beta) was 6.909 +/- 0.483 and 7.094 +/- 0.350 hr; the absorption constant (Ka) was 2.444 +/- 0.188 and 2.490 +/- 0.096 hr-1; the absorption half life (T1/2, alpha) was 0.278 +/- 0.019 and 0.277 +/- 0.010 hr; the area under curve (from 0 to 12 hours) (AUC0-12) was 7.106 +/- 1.065 and 7.380 +/- 1.044 micrograms.hr/ml; and the area under curve (from 0 hour to infinity) (AUC0-infinity) was 9.183 +/- 1.257 and 9.550 +/- 1.300 micrograms.hr/ml respectively. There were no significant difference found between the two groups after statistical analysis with two-way ANOVA (p greater than 0.05). A series of statistical parameters including d%, delta, and 95% C.I. were calculated by a bioequivalence test computer software of Yamaoka Simi. In order to strengthen the statistical evidence, the power of the test (1 - beta) was also calculated. After evaluating all the parameters, there was no significant difference found between the two groups. Therefore, the high similarity of these two formulations is suggested by the authors.

Adult↗

PubMed1990

Studies of neuron-specific enolase levels in serum and cerebrospinal fluid of children with neurological diseases.

Neuron-specific enolase (NSE) has recently proved to be a useful marker of neuron damage. We determined NSE levels in the serum and CSF of 117 children with various neurological disorders (43 with febrile convulsion, 25 with seizure disorder, 32 with meningitis, 3 with brain tumor, 2 with Reye syndrome, 3 with congenital CNS malformation and 9 with other disorders). The purpose of this study is to assess the potential usefulness of NSE in diagnosis and prognosis. Twenty CSF and serum samples of children without neurological problem served as a control. The mean values of the NSE levels in the CSF and serum of the control group were 5.00 +/- 1.65 ng/ml and 8.34 +/- 4.40 ng/ml respectively. The peak values were found in cases with brain tumor. A patient died of Reye syndrome didn't show a very high level of NSE in the serum or CSF. However, we found significant differences in NSE levels between the patients with febrile convulsions and those with seizure disorders (non-febrile, abnormal EEG). Most of our patients with febrile convulsions were cases of simple febrile convulsion, and their NSE levesin the CSF and serum were 4.55 +/- 1.00 and 8.06 +/- 3.18 ng/ml. Cases with non-febrile seizure disorders had significantly higher level of NSE in both CSF and serum (P less than 0.05). Patients with purulent meningitis usually had higher levels than those with aseptic meningitis. Our study can be summarized thus: 1. A normal level of NSE does not exclude severe neuron damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗

PubMed1989

Brain abscesses in children--a cooperative study of 83 cases.

This study reviews our experience in 83 cases of brain abscesses in children diagnosed at seven teaching hospitals during the 10-year period from June 1978 to July 1987. The average age of the patients was 7 years, with 12% of them less than 1 year old. The male-to-female ratio was 1.7:1. Of the brain abscesses, 90.4% were detected by CT brain scan. A total of 50.6% patients had congenital heart disease, and 20.4% patients had sepsis and/or meningitis. Only 6% cases had ear, nose, and throat infection. Sixty-eight (81.9%) patients received a combination of antibiotics and surgical treatment. The cerebral abscesses were totally excised in 26 cases, aspirated and partially excised in 6, and aspirated in 32. Sixty patients had pus cultures from the cerebral abscesses. Organisms were isolated in 29 (49.2%) of them. Streptococcus was by far the most common organism. The overall outcome was: 49 (59%) alive; 16 (19.3%) dead; 18 (21.7%) lost to follow-up. Among the 16 mortalities, the causes of death were due to failure to treat the diseases causing the brain abscesses. We had a better outcome in patients whose cerebral abscesses were totally excised or whose abscesses were aspirated, and in patients who were older than 1 year of age.

Adolescent↗

PubMed1989

Different respiratory patterns elicited by microinjection of L-glutamic acid into the ventrolateral nucleus of the tractus solitarius in cats.

Only limited information relating neurotransmitters to central regulation of the respiratory system exists. L-glutamic acid has been proposed as the primary neurotransmitter in the nucleus of the tractus solitarius (NTS) of cats. To test whether or not glutamic acid has an effect on the respiratory center, we microinjected L-glutamic acid (1 M, 0.1 microliter) via a 1 microliter Hamilton microsyringe into the ventrolateral area of the NTS dorsal respiratory groups (DRG) of unanesthetized, decerebrated cats at two-second intervals with continuous monitoring of tidal volume (VT), respiratory rate (f), end tidal CO2, blood pressure and heart rate. The results showed that glutamate induced the following respiratory changes: VT and f increased; VT and f decreased; and VT decreased but f increased. In addition to VT or f changes elicited by glutamate microinjection, changes in other rhythmic patterns such as apnea, apneusis and irregular respiration were observed. Glutamic acid appears to play a significant role in the modulation of the respiratory drive in the DRG. We, therefore, suggest that the excitatory amino acid L-glutamic acid may be involved in central respiratory control.

Animals↗

PubMed1989

[The measurement of airway responsive index in normal individuals and asthmatic patients].

Measurement of airway responsiveness to nonallergenic stimuli can be used to confirm the diagnosis of asthma, document the severity of airway responsiveness, and follow changes in airway responsiveness with time in relation to treatment or exposure to occupational sensitizers. Methacholine inhalation is the preferred test for the clinical laboratory as it is more sensitive than exercise or cold air, and there are fewer side effects than with histamine. Airway responsiveness to nonspecific, pharmacologic, bronchoconstricting stimuli has been described using various methods of summarizing dose-response data. The purpone of this study was to examine a simple index of nonspecific airway responsiveness to methacholine, i.e., the slope of a straight line approximation of the dose-response curve. Twelve normal and 19 asthmatic volunteers were studied. Subjects underwent a standard methacholine challenge test, both specific airway conductance (SGaw) and forced expiratory volume of one second (FEV1) were measured. We examined the relationship between response assessed by SGaw or FEV1 and dose of methacholine in each subject. The results showed that, in most of the subjects, the decline of pulmonary function with increasing dose of methacholine almost followed a simple linear relationship. A straight line extending from the origin to the last data point obtained approximating this relationship provides a reasonable summary of each plot. This were true not only in asthmatic subjects but also in normals, and not only for FEV1 but also for SGaw. The slope of this straight line was denominate as responsive index. The summary dose-response slope effectively separated asthmatic from normal subjects without any overlapping; this was true not only when FEV1 but also for SGaw was used as the parameter of response. The responsive index was much greater among asthmatics than among normal subjects (P less than 0.001). The responsive index from the parameter of SGaw was nearly perfectively correlated with which was from FEV1 (r = 0.989, P less than 0.001). We considered that airway responsive index can be calculated not only when FEV1 but also SGaw was used as a parameter of pulmonary function response. The dose-response slope calculated in the present analysis is a summary of the overall dose-response relationship and thus differs from the slope of the latter part of the log dose-response curve. It has the advantage of providing a single, continuous, easily interpreted measure of responsiveness for all subjects.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗