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Biomedical subjects

B L Chang

Publications and source records attributed to B L Chang.

At least 55 records · Page 3Linked to original sources
PubMed1992

Unilateral congenital ocular motor apraxia: a case report.

Congenital ocular motor apraxia (COA), first described by Cogan in 1953, is a rare disorder which shows characteristic defects of the horizontal voluntary saccades, and compensatory head thrust. Until now, most cases have showed a presumably congenital origin, bilaterality, and a tendency to various stages of recovery with aging. But the cause and mechanism of COA are not completely known. Occasionally, it combines with other neurologic abnormalities and metabolic diseases such as Gaucher's disease exhibit similar clinical characteristics to COA. We recently experienced a case of a 3-year-old girl who showed the clinical features of unilateral congenital ocular motor apraxia.

Apraxias↗
PubMed1992

Electron microscopic study on overacting inferior oblique muscles.

Overaction of the inferior oblique(IO) muscle is manifested by elevation of the adducted eye and from the clinical point of view there are two types of overaction. The primary type is of unknown cause, whereas the secondary type is usually related to the palsy of the ipsilateral superior oblique or contralateral superior rectus. An ultrastructural study on the overacting IO muscles was performed compared to normal IO muscles by electron microscopy. Of 16 biopsies of overacting IO muscles, four had primary overacting inferior obliques and twelve had secondary overacting inferior obliques due to paralysis of superior oblique muscle. Additional four IO muscle, obtained from patients with intraocular diseases served as control specimens. The most striking abnormalities were aggregations of mitochondria and degenerating mitochondrial profiles and increased vacuolization in primary and secondary overacting muscles. Many muscle fibers were in different stages of atrophy, and hypertrophy and regeneration of muscle fibers were sometimes visible. The results suggest that the primary overacting IO muscle might be the result of a paresis of the superior oblique muscle.

Biopsy↗
PubMed1992

[Integrated traditional and Western medicine treatment of severe viral myocarditis].

33 patients divided into 2 groups for treatment. Group A (18 cases) early use of adrenal cortico-steroid treatment in combination with traditional Chinese medicine; group B (15 cases): early use of adrenal cortico-steroid treatment is combination with interferon, then compared the therapeutic effects of these 2 groups. The results showed that, in these 2 groups, the sinus-atrial block, atrial ventricular block, ventricular tachycardia, acute pump failure as well as the EKG changes were relieved and improved to the same degree. In group A, after therapy, the parameters of OKT3 (%) was elevated from 51 +/- 15.22 to 55.23 +/- 8.53; OKT4(%) was elevated from 30.06 +/- 11.47 to 47.32 +/- 10.87; ratio of OKT4/OKT8 was elevated from 1.11 to 1.53; all of their P values were < 0.01. NK cell activity was elevated from 8.36 +/- 3.75 to 13.08 +/- 5.77, P value < 0.05. In group B, the parameters of OKT3 (%) was elevated from 50.91 +/- 8.12 to 56.75 +/- 8.29; OKT4 (%) was elevated from 32. 55 +/- 6.78 to 45.13 +/- 10.85; ratio of OKT4/OKT8 was elevated from 1.00 +/- 0.21 to 1.37 +/- 0.16; P value < 0.05, < 0.05 and < 0.01 respectively. NK cell activity (%) was elevated from 8.20 +/- 3.08 to 14. 0.3 +/- 4.89, P value also < 0.01. Hence, not only in group A but also in group B, after therapy, the parameters of OKT3,4,8, OKT4/OKT8 and NK cell activity (%) were all improved. But there was no significant statistical difference between group A and B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adams-Stokes Syndrome↗
PubMed1991

Agitation in the demented patient. A framework for management.

The inability to manage agitation has led to institutionalization of the patient by the family, overuse of physical restraints, and inappropriate use of psychotropic medication, all of which confound the behavior of the demented individual. It is not only the behavior of the patient but also the interpretation of that behavior that is critically important in the successful management of agitation. Caregivers must be careful to assess their own reactions and responses to patient behaviors before actions are taken that may not lessen agitation but increase the frequency and intensity of patient action.

Aged↗
PubMed1990

Effects of ibuprofen on pulmonary oedema in an animal smoke inhalation model.

The ability of ibuprofen to lower extravascular lung water significantly was examined in an animal smoke inhalation model. Adult New Zealand White rabbits weighing 3-5 kg were anaesthetized and intubated. They were then allowed to breathe cooled cotton smoke until the carboxyhaemoglobin (COHb) reached a level of 60 per cent or higher. Each ibuprofen-treated animal received a dose of 50 mg/kg either intraperitoneally or intravenously. Ibuprofen was administered to animals that received smoke inhalation alone and those that received smoke inhalation combined with a 10 per cent BSA partial skin thickness thermal injury. Control groups were established for both of the above-mentioned groups. Peak carboxyhaemoglobin levels as well as CO half-lives were not significantly different between ibuprofen-treated groups and the controls. Ibuprofen treatment resulted in significantly (P less than 0.05) decreased lung water in both smoke, and smoke plus thermal injury groups as compared to controls. These results suggest that ibuprofen promotes the reduction of early-onset lung water resulting from smoke inhalation injury alone or from smoke inhalation injury plus a thermal injury.

Animals↗
PubMed1989

Pathologic findings after recession and resection of extraocular muscles in rabbits.

A study on the pathologic findings after recession and resection of extraocular muscles in rabbits was performed. Fibrosis of the extraocular muscles increased with time, which showed no difference between the recessed and resected muscles. Inflammation and foreign body reaction decreased with time, which showed no difference between the recessed and resected muscles. Adhesions of extraocular muscles to the sclera were observed from one month after the operation. The resected muscles showed milder adhesion to the sclera than the recessed ones. The operated extraocular muscles showed atrophies at one month, which showed no difference between the recessed and resected muscles. According to our results, when reoperation is needed, fibrosis of the extraocular muscles after recession and resection should be considered when making a decision on the amount of muscle to be recessed and resected.

Animals↗
PubMed1989

The pattern of delivery and distribution of coronary venous retroinfusate in canine hearts.

The delivery and distribution of retroinfusate premixed with radionuclide microspheres (15 microns) in the coronary venous system of canine hearts was studied in in vitro and in vivo experiments. Results showed that about 51-85% of the retroinfusate was shunted directly by vessels greater than 15 microns in diameter to the right heart in cases of isolated heart study, while the remaining 21-42% passed through intramyocardial capillaries with obvious nutritional effects. In the closed-chest experiments, 95% of the retroinfusate was bypassed to the right heart; less than 5% went through the intramyocardial microcirculation system. Intramyocardial distribution pattern of the retroinfusate indicated a predominant supply to the left ventricular free wall. There was a preferential distribution of the retroinfusate to the ischemic area with a subendo subepi blood flow ratio of up to 1.79 +/- 0.21 post-LAD occlusion.

Animals↗
PubMed1987

Enhanced myocardial washout and retrograde blood delivery with synchronized retroperfusion during acute myocardial ischemia.

The effects of synchronized coronary venous retroperfusion of arterial blood on myocardial washout were studied with digital subtraction angiography in 10 closed chest dogs during balloon occlusion of the proximal left anterior descending coronary artery. The center lumen of the intracoronary balloon catheter was used for sequential injections of 1 ml (meglumine diatrizoate) Renografin-76, and contrast washout rate was determined by videodensitometry in myocardial regions subserved by the left anterior descending coronary artery. Before coronary artery occlusion, washout rate was 22.4 +/- 2.7 min-1 (mean +/- SEM). Five minutes after occlusion, and immediately before synchronized retroperfusion, washout rate dropped sharply to 2.0 +/- 0.7 min-1. Twenty-five minutes after occlusion, with 50 ml/min synchronized retroperfusion treatment applied for 5 minutes, washout rate was 5.0 +/- 1.5 min-1. Thus, synchronized retroperfusion significantly (p less than 0.05) accelerated contrast disappearance over that during presynchronized retroperfusion ischemia. To determine the effects of synchronized retroperfusion on retrograde delivery to the ischemic myocardium, monastral blue dye was retroinfused through the system into the great cardiac vein before the dog was killed. Transverse heart slices were then studied by light microscopy, and regional intravascular dye content was scored from 0 to 3 (0 = no dye, 3 = maximal dye). After great cardiac vein synchronized retroperfusion, blue dye content in capillaries of ischemic anterior and nonischemic posterior aspects of the left ventricle was 2.3 +/- 0.5 versus 0.7 +/- 0.3, respectively (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1986

Digital angiographic measurement of radiographic contrast material kinetics for estimation of myocardial perfusion.

We studied the use of digital angiography for the quantification of regional myocardial perfusion in the dog using selective left coronary arterial injection of radiographic contrast material as a flow dilution indicator. We developed algorithms for generating time-intensity curves from regions of interest over the proximal coronary artery and the myocardium and for densitometric error correction by subtraction of the intensity curve over a small lead blocker before logarithmic transformation. The resultant myocardial time-density curves were analyzed for time from injection to peak concentration (TPC) and for exponential washout rate (k). A linear correlation was found between absolute coronary arterial blood flow and both k (slope = 0.13, r = .85) and 1/TPC (slope = 0.18, r = .85). Reproducibility of TPC and k for repeated studies was 11% and 16%. Induced hyperemia significantly improved the sensitivity to stenosis by increasing the average difference in TPC and k between regions served by normal and stenotic coronary arteries to 65% and 80%, respectively. By combining selective coronary arterial injection with the left lateral x-ray projection it was possible to avoid most overlap of regional perfusion beds in the dog. This study suggests that contrast dilution measurements made during digital coronary angiography provide a means for assessing the hemodynamic significance of stenoses and the efficacy of therapeutic interventions.

Angiography↗