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Biomedical subjects

C C Chen

Publications and source records attributed to C C Chen.

At least 577 records · Page 32Linked to original sources
PubMed1988

[Immunological study of colostrum].

Breast milk has many advantages over cow's milk in feeding of infants. Breast-fed newborns usually have much less chance of infections than do bottle-fed ones. In this communication, the cellular and humoral immunocompetent components in the colostra of 80 mothers were studied. The results showed: 1) Colostrum contained a large number of viable leukocytes as blood, but the vast majority was monocyte/macrophage (63.76%); 2) T and B lymphocytes were present in the colostrum, the number of T cell was much less than that of the blood; 3) The colostral mononuclear cells (MNC) had lymphoproliferative responses to mitogens and the mitogenic capability decreased gradually postpartum; 4) The colostral MNC were able to produce interleukin 2, and 5) Immunoglobulins G, A and M and C3 and C4 were present in small amount in the colostrum, however, the concentration of IgA was nearly half of that of the blood. In conclusion, colostrum contains a lot of cellular and humoral immunocompetent components which will confer newborns with passive immunity to various microorganisms.

B-Lymphocytes↗
PubMed1988

Effects of gating modes on the analysis of left ventricular function in the presence of heart rate variation.

Variations in cardiac cycle length during ECG-gated radionuclide ventriculography cause errors in measurement of left ventricular (LV) diastolic function. We used a computer model to investigate the relative accuracy of forward gating (FG), backward gating (BG), and three methods of combined forward-backward gating (FBG). LV time-activity curves (TAC) were simulated with total cycle lengths randomly varied (1 s.d. = +/- 10%). To match the known differential effects of cycle-length variation on various parts of the cardiac cycle, 90% this variation was placed in diastasis and 10% in the rapid filling phase. Three hundred cycles of TACs were summed to form one "study". A total of 25 studies were performed and systolic and diastolic parameters were determined for each. These were compared to those of the mean length TAC. With a 20% cycle-length acceptance window, error in peak filling rate by FG was 0.7% root-mean-squared (RMS) compared to 18.5% RMS by BG. With a 5% window, RMS error by FG was 0.2% and 2.4% RMS by BG. Combined FBG algorithms gave intermediate results. We conclude that the simplest and most accurate method of analysis is to acquire forward gated TACs with appropriate cycle-length windows.

Algorithms↗
PubMed1987

Rat intestinal trehalase. Studies of the active site.

Rat intestinal trehalase was solubilized, purified and reconstituted into proteoliposomes. With octyl glucoside as the solubilizing detergent, the purified protein appeared as a single band on SDS/polyacrylamide-gel electrophoresis with an apparent molecular mass of 67 kDa. Kinetic studies indicated that the active site of this enzyme can be functionally divided into two adjacent regions, namely a binding site (with pKa 4.8) and a catalytic site (with pKa 7.2). Other findings suggested that the catalytic site contains a functional thiol group, which is sensitive to inhibition by N-ethylmaleimide, Hg2+ and iodoacetate. Substrate protection and iodoacetate labelling of the thiol group demonstrated that only a protein of 67 kDa was labelled. Furthermore, sucrose and phlorizin protected the thiol group, but Tris-like inhibitors did not. Structure-inhibition analysis of Tris-like inhibitors, the pH effect of Tris inhibition and Tris protection of 1-(3-dimethylaminopropyl)-3-ethylcarbodi-imide inactivation permitted characterization and location of a separate site containing a carboxy group for Tris binding, which may also be the binding region. On the basis of these findings, a possible structure for the active site of trehalase is proposed.

Animals↗
PubMed1987

An initial screening of serum lipids and fatty acid profiles of hypertensive and normotensive subjects.

Serum lipids and their acyl group profiles from a group of hypertensive patients with elevated systolic and diastolic pressure were compared with normotensive subjects of matched age, body weight and dietary habits. The level of serum triacylglycerols was elevated in the hypertensive subjects, but the cholesterol level remained normal. The acyl groups of serum triacylglycerols and cholesterylesters from hypertensive subjects indicated a higher proportion of the saturated fatty acids (16:0 and 18:0) and a lower proportion of linoleic acid (18:2) as compared to normal controls. There was no obvious change in the level and acyl group composition of serum phosphatidylcholine between the two groups. Since the hypertensive and normotensive subjects indicated similar dietary habits, the resulting differences in serum lipids reflected an abnormality in the lipolytic process in the hypertensive subjects.

Body Weight↗
PubMed1987

Role of surgery in the treatment of primary carcinoma of the liver: a 31-year experience.

During the 31 year period 1954 to 1985, 225 major hepatic resections have been performed for symptomatic primary carcinoma of the liver, of which right hepatic lobectomy was performed in 115, extended right hepatic lobectomy in 11, trisegmentectomy in 2, left hepatic lobectomy in 94, and middle hepatectomy in 3. In addition there were 107 partial hepatic resections for 89 asymptomatic small hepatocellular carcinomas. In the 225 patients undergoing major hepatic resection, the operative mortality was 8.0 per cent. In the 107 patients undergoing partial hepatic resection, the operative mortality was 5.6 per cent. Of the total of 314 hepatic resections for primary carcinoma of the liver, 309 were undertaken for hepatocellular carcinoma and the remaining 5 were carried out for cholangiocarcinoma. All hepatic resections in this series were performed with the finger fracture technique without controlling the hepatic hilar vessels, hepatic ducts or hepatic veins outside the liver, although hepatic clamping and the Pringle manoeuvre were also used in selective cases. Of 207 cases who survived major hepatic resection, 119 cases died within one year after the operation, mainly due to recurrence of cancer in the remaining residual lobe, lung metastasis or late hepatic failure. The 5 year survival rate is 18.0 per cent, 12 patients are still alive and well after more than 5 years and the longest survival is 23 years. Of the 89 patients with small asymptomatic hepatocellular carcinomas, 28 died within one to four years of surgery because of a second new growth.

Adult↗
PubMed1987

The disposition of bunolol in the rabbit eye.

Following topical administration to albino rabbits, bunolol hydrochloride, a beta 1- and beta 2-adrenoceptor antagonist, was rapidly absorbed and distributed in ocular tissues, and transformed intraocularly to a single metabolite, dihydrobunolol. The half-life of bunolol was approximately 1.26 hours in the aqueous humor and 1.63 hours in the ciliary body. There was no significant accumulation of bunolol during a four-day period of twice-daily dosing. Most of the drug was excreted in the urine following ocular or intravenous administration.

Absorption↗
PubMed1987

Alterations of Na+-K+-ATPase, Ca2+-ATPase, and Mg2+-ATPase activities in erythrocyte, muscle, and liver of traumatic and septic patients.

Na+-K+-ATPase, Ca2+-ATPase and Mg2+-ATPase activities of erythrocyte membrane, microsomal fractions of rectus muscle, and liver were measured colorimetrically in the biopsy specimens of 14 control, 7 uncomplicated trauma (group 2), and 14 severe trauma or septic patients (groups 3-A and 3-B). In erythrocytes, these three ATPase activities in group 2 were not significantly changed but sepsis of both the acute (group 3-A) and ongoing type (group 3-B) decreased all of the ATPase activities. In muscle, there was a significant loss of three ATPase activities in the acute insult of severe trauma or sepsis (group 3-A), while Na+-K+-ATPase and Mg2+-ATPase activities were not significantly changed in ongoing, severe trauma (group 3-B). In the liver, a tendency for all three ATPase activities to decrease is noted in the severe traumatic group. However, a statistical difference between the control and severe traumatic group showed only for Na+-K+ ATPase and Mg2+-ATPase in group 3-A and Ca2+-ATPase in group 3-B. Correlation coefficients between erythrocyte, muscle, and liver for three ATPase activities are between 0.4 and 0.5. The mechanism which alters ATPase activity remains unknown in this study, but it may account for the variation in traumatic insult, in hemodynamic and hormone changes, and in tissue energy stores.

Adenosine Triphosphatases↗
PubMed1987

Exsheathment of microfilariae of Brugia pahangi in Anopheles quadrimaculatus and Culex quinquefasciatus.

In order to determine whether the exsheathment patterns described in our previous study occurred in other microfilaria-mosquito systems, exsheathment of microfilariae of Brugia pahangi was studied in two species of mosquitoes. The results of the quantitative observation revealed that the microfilariae of Brugia pahangi tend to carry their sheaths into the haemocoel of Anopheles quadrimaculatus and Culex quinquefasciatus within 4 hr after infected blood meals. The percentage of the sheathed microfilariae in the haemocoel progressively decreased to 0% at 24 hr post-ingestion. Microfilariae remaining in the midgut of both species of mosquitoes were recorded most frequently casting off their sheaths in the midgut 2 hr post-ingestion. The percentage of microfilariae exsheathed in the midgut progressively increased to about 100% and 40% 24 hr post-ingestion in Anopheles quadrimaculatus and Culex quinquefasciatus respectively. These results confirm that exsheathment of microfilariae of Brugia pahangi occurs both in the haemocoel and in the midgut of two species of mosquitoes.

Animals↗