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Biomedical subjects

T C Kao

Publications and source records attributed to T C Kao.

9 recordsLinked to original sources
PubMed1992

Photic maculopathy after extracapsular cataract surgery. A prospective study.

Photic retinal injuries have been described after surgical exposure to the intense illumination systems of operating microscopes. The overall incidence of such injuries has been postulated at less than 10%. The authors prospectively studied 43 consecutive patients to determine the incidence of photic macular injuries during cataract surgery. Patients underwent complete ophthalmic examinations, fundus photography, and oral fluorography before and after surgery. Photic macular injuries developed in 12 of 43 eyes (28%) as a result of intraocular surgery. This incidence is much higher than previous estimates. The association with possible risk factors, cystoid macular edema, and the effect of these injuries on final visual acuity are discussed.

Cataract Extraction↗
PubMed1992

Analyzing the effect of prenatal care on pregnancy outcome: a conditional approach.

We used vital statistics data to examine the effect of the time of entry into prenatal care relative to the gestational age of delivery on pregnancy outcome. Early entry into prenatal care was associated with better outcomes only in women who delivered at 37 through 42 weeks of gestation. We are concerned that the evaluation of the effect of prenatal care using vital statistics data may be questionable because of the problems inherent in the data.

Bias↗
PubMed1992

The clinicopathological implication of myocytes with contraction bands in autopsy hearts. Quantitative analysis of myocytes with contraction bands in autopsy hearts.

To define the normal extent of myocytes with contraction bands, 51 adult autopsied hearts including 30 normal and 21 common hypertrophic hearts were studied. Based on the histologic features, contraction bands were divided into mild and severe types. They were found in 48 and 32 of the total 51 cases, respectively. However, in five hearts, myocytes with contraction bands were more diffused or localized in one part of the ventricular wall. There were no special different treatments before death among the five cases or others. They seemed however to correlate with sudden death or acute cerebral damages. Therefore, reperfusion injury and metabolic cell injuries were considered. If these 5 cases were excluded, the normal extend of myocytes with contraction bands was considered as less than a 1.7% area in the mild type and a 0.5% area in the severe type found in the ventricular wall. These mild and severe contraction bands were considered related to autolysis or events occurring before death.

Adult↗
PubMed1991

Cryptosporidium infection in an adult mouse model. Independent roles for IFN-gamma and CD4+ T lymphocytes in protective immunity.

Cryptosporidium is a protozoan parasite that can cause chronic life-threatening diarrhea in immunocompromised persons. Host immune responses are poorly understood, an impediment to development of effective therapy. In mice, normal adult BALB/c animals resist infection whereas chronic symptomatic cryptosporidiosis develops in adult nude mice and in neonatally infected BALB/c mice treated with anti-CD4 mAb. To define further the immune defects that allow mice to be infected with Cryptosporidium, adult BALB/c mice were treated with cytolytic anti-CD4 or anti-CD8 or with neutralizing anti-IFN-gamma or anti-IL-2 mAb. Chronic infection, manifested by continuous shedding of sparse but statistically significant numbers of oocysts, occurred with anti-CD4 +/- anti-CD8 mAb treatment although anti-CD8 mAb treatment alone did not allow infection. Treatment with anti-IFN-gamma mAb greatly enhanced oocyst shedding but infection was self-limited. Treatment with a combination of anti-CD4 and anti-IFN-gamma mAb permitted both chronic infection and shedding of large numbers of oocysts. Furthermore mice treated initially with anti-CD4 mAb showed a substantial increase in oocyst shedding when later treated with anti-IFN-gamma mAb; and mice treated initially with both mAbs showed a decline in oocyst shedding when anti-IFN-gamma mAb was stopped. Anti-IFN-gamma mAb treatment of congenitally athymic adult BALB/c mice led to an approximately a 75-fold increase in oocyst shedding. Treatment of adult BALB/c mice with anti-IL-2 mAb did not permit Cryptosporidium infection. These results suggest that redundant immunologic mechanisms limit Cryptosporidium infection such that both CD4+ cells and IFN-gamma are required to prevent initiation of infection whereas either alone can limit the extent (IFN-gamma) or duration (CD4+ T cells) of infection. They also suggest that production of IFN-gamma by a non-T cell contributes to host immunity.

Analysis of Variance↗
PubMed1991

Changes in human plasma catecholamine concentrations during epidural anesthesia depend on the level of block.

To test the hypothesis that increasing levels of epidural analgesia will produce progressive decreases in circulating catecholamines, we sequentially produced three levels of analgesia, T8, T4, and C8, to pin prick in young, healthy volunteers. Three percent chloroprocaine (plain) was used as the local anesthetic. The epidural analgesia was allowed to dissipate following the T8 and T4 levels of block. After the C8 level the block was reinforced to study the effect of a "top-up" dose. Blood samples were drawn from a central venous catheter. Plasma concentrations of norepinephrine and epinephrine were determined by the single isotope radioenzymatic method. Despite extensive block, hemodynamic alterations were minimal, and no significant decrease in plasma epinephrine was observed as the level of analgesia was raised to the C8 dermatome. When the level of analgesia was raised above T8, there was a trend for norepinephrine to decrease, but this decrease did not become statistically significant until analgesia reached the C8 dermatome. Reinforcing the epidural block at the C8 level of analgesia resulted an insignificant decrease in epinephrine and norepinephrine NE. Under the conditions of the present study, epidural block with a sensory analgesia level as high as C8 did not significantly decrease the plasma concentration of epinephrine in unstressed volunteers. The plasma concentration of norepinephrine significantly decreased only when the level of sensory analgesia was approximately C8.

Adult↗
PubMed1986

Pathology of Kawasaki disease in the healed stage. Relationships between typical and atypical cases of Kawasaki disease.

To define the pathological features of Kawasaki disease (KD) in the healed stage (over 40 days of illness), 69 autopsied infants with clinically typical KD (25 in the healed stage and 38 in the acute stage) and atypical KD (four in the healed stage and two in the acute stage) were examined. In the medium-sized arteries with coronary aneurysm in KD, panvasculitis was evident in the acute stages, while scar formation was noted in the healed stage. Thrombi, marked intimal thickening, marked stenosis, and recanalization were seen in the coronary arteries. In KD without aneurysm, acute inflammation was localized in the intima and the perivascular area of the coronary arteries in the acute stages, but was absent in the healed stage. Although intimal thickening was noted, marked stenosis and thrombi were not evident in KD without aneurysm. In KD with and without aneurysm, acute angiitis in small arteries and micro-vessels and acute inflammation of various organs were noted in the acute stages, but disappeared in the healed stage. Fibrinoid necrosis of the artery was rare in the acute stages and was not noted in the healed stage. Atypical cases of KD showed the same pathological features as those in cases with clinically typical KD. The common cause of death in the healed stage was ischemic heart disease. Old myocardial infarction was noted in 80% of the cases, and acute myocardial infarction was seen in 35%. KD is an acute systemic inflammatory disease and KD without aneurysm is a disease with mild angiitis.

Autopsy↗
PubMedDate not supplied

Differential epidural block.

BACKGROUND AND OBJECTIVES: Loss of sensation to pinprick and cold are commonly used to test the extent of epidural anesthesia. To see what difference exists between the level of epidural block determined by various sensory modalities, we performed this study in ten volunteers using epidural anesthesia with plain 3% chloroprocaine hydrochloride. METHODS: Four injections of chloroprocaine were made via an epidural catheter inserted at L2-3 with increasing larger volumes. Sensory modalities tested were (1) absence of sensation when tested by pinprick (anesthesia), (2) loss of a sharp sensation compared to an unblocked dermatome when tested by pinprick (analgesia), and (3) loss of cold sensation when tested with an alcohol swab compared to an unblocked dermatome. RESULTS: At 20 minutes after each injection the level of anesthesia was found to be most caudad and the level of analgesia most cephalad. The zone of differential block was greater than four dermatomes at the highest level of block tested. The level of loss of cold sensation was found between the other two levels. Differences between the levels of analgesia and cold sensation tended to be greater with more extensive block. Differences between levels of anesthesia and cold sensation did not significantly change as the extent of epidural anesthesia was increased. CONCLUSIONS: This study establishes the existence of a differential epidural anesthesia during high thoracic block with chloroprocaine and suggests that the intensity of block diminishes as distance from site of injection increases.

Adult↗