Biomedical subjects

P C Chang

Publications and source records attributed to P C Chang.

At least 37 records · Page 2Linked to original sources

PubMed1999

The angiotensin-converting enzyme genotype and microalbuminuria in autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (AD-PKD) has a variable clinical course. Clinical parameters associated with a worse prognosis are hypertension and proteinuria or microalbuminuria (MA). Because chronic stimulation of the renin-angiotensin system is likely to be present in ADPKD patients, the effect of the angiotensin-converting enzyme insertion/deletion (ACE I/D) genotype on the variability of these clinical parameters was examined in untreated ADPKD patients. Proteinuria and MA were determined in 24-h urine collections. BP measurements were performed with an ambulatory monitor, over 24 h. With analysis of covariance, the ACE genotype was found to be significantly associated with MA, corrected for age, gender, GFR, mean arterial pressure, body surface area, and urinary Na+ excretion (P < 0.05). The patients homozygous for the deletion (DD) had the highest rate of MA (P < 0.05) compared to the patients homozygous for the insertion (II). There was no relationship between the ACE genotype and BP or renal function. A significant positive correlation was found between MA and mean arterial pressure (r = 0.31, P < 0.05), whereas a significant negative correlation was found between MA and renal function (r = -0.28, P < 0.05). In conclusion, in ADPKD patients, MA is partly determined by the ACE I/D polymorphism. Because MA is associated with an enhanced progression toward renal failure, the ACE genotype could help in identifying patients at risk for a worse prognosis.

Adult↗

PubMed1999

The results of autogenous tibial periosteal transplants for full thickness cartilage defects in the knee joints of pigs.

An experimental study was conducted to demonstrate macroscopic and microscopic healing of full thickness cartilage defects with mature stable hyaline cartilage after autogenous tibial periosteal transplants in the knee joints of pigs. Similar full thickness osteochondral defects were created in the medial femoral condyles of both knees in 10 healthy young adult pigs. Periosteal transplants were performed on the left knees and the right knees used as controls. The pigs were sacrified in two groups at 6 weeks and 3 months. The knees were inspected for healing and stability of the graft. Microscopic sections were taken and evaluated using a histological score developed by O'Driscoll. Macroscopically, almost all defects with periosteal grafts healed with a translucent bluish-white colour indicating articular cartilage formation. There was good restoration of the bony contour and filling of the defects were superior to controls. Histologically, we were able to demonstrate immature hyaline cartilage which matured at 3 months. The newly formed tissue was stable and well-incorporated. It had almost complete bonding to the adjacent articular margin, good reconstitution of the osteochondral junction and a well maintained structural integrity. We concluded that periosteal transplants in the knee of a pig model healed with mature stable hyaline cartilage.

Animals↗

PubMed1999

Effects of arm dominance and brachial artery cannulation on forearm blood flow measured by strain-gauge plethysmography.

The human forearm model is used extensively in physiological, pharmacological and clinical investigations. Effects of arm dominance or arterial cannulation on forearm flow measurements have never been tested formally. In the present study we tested the hypotheses that left or right arm dominance or cannulation of the brachial artery do not affect forearm haemodynamic responses to physiological or pharmacological stimuli. Results obtained in 16 volunteers showed that forearm blood flow responses to physiological stimuli are comparable before and after intra-arterial cannulation in either the dominant or the non-dominant forearm. Cannulation of a forearm brachial artery has a small effect on baseline blood flow. Responses to intra-arterially infused noradrenaline (norepinephrine) were not influenced by left or right arm dominance. Intravenous infusion of noradrenaline in eight subjects resulted in small responses in forearm blood flow that were slightly asymmetrical. During the intravenous infusion of noradrenaline, forearm blood flow or the forearm blood flow ratio did not reflect the marked increase in FVR that occurred. These results support our hypotheses (a) that either arm can be used as the control or intervention arm, and (b) that intra-arterial cannulation does not affect the results of intra-arterial infusion studies.

Adult↗

PubMed1998

Characterization of the C-terminal domain of Helicobacter pylori vacuolating toxin and its relationship with extracellular toxin production.

Helicobacter pylori vacuolating cytotoxin (VacA) induces gastric epithelial necrosis. Its C-terminal domain is hypothesized to be responsible for extracellular translocation of the mature cytotoxin. In this study, genetic-structural properties of VacA C-terminal domain and the level of cytotoxin secretion were investigated. Sau3AI-HaeIII restriction fragment length polymorphism (RFLP) analysis of the 1.1-kb PCR-amplified vacA fragment revealed 14 distinct combined patterns among 87 clinical isolates. Of the 4 popular groups (A-a, A-b, A-f, and B-a), A-a strains produced a higher level of the VacA protein than A-b strains and than A-f strains (P < 0.05). Sequence analysis and secondary structure prediction supported a beta-barrel structure that might act as a selective export channel like Iga beta-core of IgA proteases. Sequence differences in the predicted beta-barrel were present among strains of different RFLPs.

Amino Acid Sequence↗

PubMed1998

Heterobifunctional membranes by plasma induced graft polymerization as an artificial organ for penetration keratoprosthesis.

Highly biocompatible polymer membrane was developed for an artificial cornea in this surface modification study. Heterobifunctional silicone rubber membranes (hetero-SR) were prepared by grafting different functional polymers on each side of a silicone rubber membrane (SR). A novel type of bifunctional membrane was developed with the upper-side favoring cell attachment and growth, and the lower-side suppressing cell adhesion. The preparation of heterobifunctional membranes, characterization of polymer membrane surface properties such as ATR-FTIR and ESCA and contact angle, and biological analysis (in vitro and in vivo studies) were investigated in this work. Based on the biological analysis, the heterobifunctional membrane displays promising potential for use as an artificial cornea.

Adsorption↗

PubMed1998

Transient ST elevation and left ventricular asynergy associated with normal coronary artery and Tc-99m PYP Myocardial Infarct Scan in subarachnoid hemorrhage.

A 72-year-old woman who presented with transient electrocardiographic ST segment elevation and left ventricular asynergy in an acute phase of subarachnoid hemorrhage was found to have normal coronary angiogram and normal Tc-99m PYP myocardial infarct scan. These findings suggested that noninvasive Tc-99m PYP myocardial infarct scan could substitute coronary angiogram for differentiating wall motion and electrocardiographic abnormalities secondary to subarachnoid hemorrhage from those caused by coronary artery disease in patients with subarachnoid hemorrhage.

Aged↗

PubMed1998

Surface characterization and biological properties study of silicone rubber membrane grafted with phospholipid as biomaterial via plasma induced graft copolymerization.

Poly(2-methacryloyloxyethyl phosphorylcholine) (pMPC) was grafted onto the surface of a silicon rubber (SR) membrane (pMPC-SR) by plasma induced grafted copolymerization (PIP). Argon plasma was used to activate the SR surfaces. Determination was also made of the influences of grafted copolymerization reaction time, reaction temperature, and monomer concentration on polymerization yield. The surface properties of SR were characterized by ATR-FTIR, ESCA, and SEM. In those analyses the ATR-FTIR spectra indicated that the pMPC grafted onto the SR surface at 1720 and 3300 cm(-1). The elemental composition and different carbon bindings on the surface of the SR were examined by ESCA. An increasing P1s/C1s value g was obtained in the grafted polymerization yield with a concentration of 0.05-0.5M of MPC in the isolated ethanol solution. The surface morphologies of pMPC-SR differed more than those of control and Ar plasma treated surfaces. The difference could have been caused by the homogeneous graft polymerization of pMPC onto the SR membrane. In the biological analyses, protein adsorption on pMPC-SR surfaces was reduced. The reduced level increased with an increase in the pMPC grafted amount. The epithelial cell attachment and growth onto these samples were suppressed. The blood compatibility for a series of pMPC-SR surfaces was examined by platelet adhesion. Blood platelet morphologies in contact with the high ratio of pMPC-SR surfaces were maintained, meaning that in this case the release reaction for platelets never occurred. Consequently, the high amount of pMPC-SR surface had excellent blood compatibility, further suggesting that prevention of adhesion, activation of platelets, and adsorption of blood protein could be achieved.

Animals↗

PubMed1998

Calculation of plasma concentrations of intra-arterially infused compounds in forearm plethysmography.

OBJECTIVE: Forearm blood flow plethysmography is a widely accepted in vivo technique for pharmacologic and functional studies in peripheral resistance vessels and veins. Pharmacological effects on forearm blood flow (FBF) are usually expressed by means of dose-response relationships. This approach does not consider the influence of variations in FBF on the actual plasma concentrations of compounds infused, and is less suitable for quantitative comparison of the pharmacologic characteristics of different compounds. The aim of this study was to validate an equation to estimate the plasma concentrations of intra-arterially infused compounds. This was done at different levels of FBF, using an indicator dilution technique with constant rate infusions of indocyanine green (ICG) and inulin. METHODS: ICG (0.5 mg/min) and insulin (5 mg/min) were infused into the brachial artery in the presence of sodium nitroprusside (10 ng/kg/min; to obtain high FBF), vehicle (0.9% saline; for intermediate FBF), and methoxamine (1 microgram/kg/min; for low FBF), FBF was measured using venous occlusion plethysmography in six healthy male volunteers. Plasma concentrations of the indicators, measured in venous blood samples, were compared with the calculated values. RESULTS: Excellent correspondence was observed between calculated and measured plasma concentrations for both ICG and inulin. Venous plasma concentrations of ICG (> or = 95% protein binding) reached steady-state within four min independent of FBF. Alternatively, the time required for venous plasma concentrations of inulin (not bound to protein) to reach steady-state appeared dependent on FBF. CONCLUSION: Total plasma concentrations of intra-arterially infused drugs can be appropriately estimated at the level of the arterioles by the proposed equation.

Adult↗

PubMed1998

Vacuolating toxin production in clinical isolates of Helicobacter pylori with different vacA genotypes.

A vacuolating cytotoxin encoded by vacA in Helicobacter pylori is known as a potential virulent determinant. The relationship between different vacA alleles, vacuolating ability, and H. pylori-related diseases was investigated. Genetic analysis of 119 isolates from Taiwanese patients revealed that 104 strains were s1a/m2, 13 strains were characterized as the s1a/m1T type, which was more homologous to the s1a/m1 strains, and 2 were characterized as the s1a/m1Tm2 chimeric type. Production of high-grade cytotoxin among 11 strains with s1a/m1T was higher (72.7%) than among 66 strains with s1a/m2 (21.2%) (P < .01). Peptic ulcer occurred in 76.9% of 13 patients with s1a/m1T strains compared with 46.2% of 104 patients with s1a/m2 strains (P < .05). These results suggest that s1a/m1T strains are associated with increased cytotoxic activity and higher ulcer prevalence than are s1a/m2 strains.

Amino Acid Sequence↗

PubMed1998

Effects of angiotensin II and losartan in the forearm of patients with essential hypertension.

OBJECTIVE: Angiotensin II type 1 receptor-mediated constrictor effects may be modulated by hypertension-related vascular changes, changes in receptor function and in neurohumoral activity. DESIGN: The forearm blood flow (FBF) effects of angiotensin II, methoxamine, and losartan were investigated in essential hypertensive patients. Minimal forearm vascular resistance was measured to determine structural vascular changes. METHODS: Seven hypertensive patients were selected, and seven matched normotensives. Angiotensin II (0.01-10 ng/kg per min) was infused during predilatation by sodium nitroprusside (6.1 +/- 0.6 ng/kg per min) before and during losartan infusion (0.3-3 microg/kg per min). Methoxamine (0.2-2 microg/kg per min) was co-infused with the nitric oxide synthase inhibitor NG-monomethyl-L-arginine. FBF, measured by venous occlusion plethysmography, was expressed as the change in FBF ratio (FBFinfused arm/FBFnon-infused arm). RESULTS: Baseline FBF (infused arm) was increased by sodium nitroprusside from 2.56 +/- 0.80 to 5.46 +/- 0.92 (P<0.05) and from 2.66 +/- 0.25 to 5.42 +/- 0.40 ml/100 ml per min (P<0.05) in the hypertensive and normotensive group, respectively. Baseline forearm vascular resistance (FVR) was higher in the hypertensive than in the normotensive group [51 +/- 8 versus 33 +/- 3 mmHg/ (ml/100 ml per min); P<0.05]. Angiotensin II caused a maximal change in FBF ratio (Emax) by -70 +/- 3 and -72 +/- 6% in the hypertensive and normotensive group, respectively (NS). Tachyphylaxis did not occur. Infusions of losartan at 0.3, 1 and 3 microg/kg per min reduced the Emax values from -70 +/- 3 to -50 +/- 5, -45 +/- 5 and -15 +/- 2%, respectively, in the hypertensive group, and from -72 +/- 6 to -62 +/- 4, -45 +/- 2 and -32 +/- 2%, respectively, in the normotensive group (NS). Infusion of methoxamine significantly reduced the FBF ratio by -58 +/- 6 and -69 +/- 5% in the hypertensive and normotensive groups, respectively (NS). Minimal FVR, after forearm ischemia, was the same in hypertensives and normotensives, namely 3.2 +/- 0.7 and 3.2 +/- 0.4 mmHg/(ml per 100 ml per min), respectively (NS). CONCLUSIONS: Angiotensin II type 1- and alpha1-mediated vascular effects were unchanged by essential hypertension. Baseline FVR was greater in the hypertensives than in the normotensives, while minimal FVR was the same. These results indicate that the forearm vascular bed of the patient group studied does not show important structural and renin-angiotensin system-related functional changes as a result of hypertension.

Adult↗

PubMed1998

Venoconstriction by angiotensin II in the human forearm is inhibited by losartan but not by nicardipine.

Arterial constriction by angiotensin II (Ang II) in the human forearm is inhibited by the infusion of the AT1-receptor antagonist losartan. We investigated venous constriction by Ang II in the forearm of 19 healthy subjects (23 +/- 1 years) and the inhibitory effects of losartan. Furthermore, we investigated, in both the arterial and venous systems, whether the constrictor effects of Ang II are calcium influx dependent by determining the influence of nicardipine. Arterial forearm blood flow (FBF) and maximal venous outflow (MVO) were measured by venous-occlusion plethysmography. Sodium nitroprusside (5-12.5 ng/kg/min) was infused to predilate the forearm vasculature. Ang II (0.1, 1, and 10 ng/kg/min) was infused before and during losartan (0.3 and 3 microg/kg/min) or nicardipine (0.05 and 0.15 microg/kg/min), respectively. Ang II decreased FBF (Emax-FBF) by 79 +/- 4% and MVO (Emax-MVO) by 28 +/- 3% (p < 0.05). Nicardipine at 0.05 and 0.15 microg/kg/min reduced Emax-FBF from -79 +/- 4% to -48 +/- 4% and -6 +/- 2%, respectively (p < 0.05). Losartan in both doses completely inhibited Emax-MVO (p < 0.05), whereas nicardipine did not influence the venoconstriction by Ang II (p > 0.05). In conclusion, Ang II causes a constriction of both arteries and veins in the human forearm, which may be inhibited by losartan. The arterial constriction appears to be caused by an AT1-receptor-mediated calcium influx via L-type calcium channels. In contrast, the venoconstrictor effect of Ang II proved insensitive to the calcium antagonist nicardipine.

Adult↗

PubMed1998

Anthropometry of anterior cruciate ligament in Singaporean Chinese.

Accurate reproduction of the anatomy of the anterior cruciate ligament during reconstructive surgery is paramount for obtaining good functional results. Graft size and length are important components of the reconstruction and the references we have used are Western figures. We feel that these Western figures do not apply to our local population. We performed an anthropometric study to test the hypothesis that the anterior cruciate ligament in the Singaporean Chinese is smaller than that quoted in Western literature. The study revealed that the anterior cruciate ligament in Singaporean Chinese is shorter and narrower. More importantly, the anterior cruciate ligament orientation in our study population is more vertical. This suggests that placement of the femoral tunnel in anterior cruciate ligament reconstruction has to be in a more vertical position to reproduce the physiometry of the anterior cruciate ligament.

Aged↗

PubMed1998

Modulation of vasoconstriction by insulin.

OBJECTIVE: To test the hypothesis that insulin differently modifies vasoconstriction and recovery from vasoconstriction induced by endogenously released versus circulating norepinephrine, and to investigate the time-dependency of its effect METHODS: Healthy male subjects were studied. Norepinephrine was infused for 10 min into the brachial artery with 40 min pauses in between, three times with vehicle and three times during concurrent intra-arterial infusion of 0.1 mU/kg per min insulin, inducing locally high, above physiologic, concentrations of insulin. We infused tyramine, to release endogenous norepinephrine from sympathetic nerve endings, similarly into six other subjects. Ratios of infused: control arm forearm blood flow (FBFi: FBFc) were determined during the infusions of agonists and for 10 min after their cessation. Because of insulin's vasodilator effect, responses to norepinephrine after vasodilatation by isoproterenol or sodium nitroprusside were also determined for six other subjects. RESULTS: Exogenous norepinephrine induced a transient peak vasoconstriction and then a partial recovery from vasoconstriction that remained stable throughout the infusion. Administration of norepinephrine decreased the FBFi: FBFc ratio by 29+/-7% (mean +/- SEM) before and 45+/-4% during infusion of insulin (P < 0.01). After cessation of the norepinephrine infusions blood flow rapidly recovered, which even resulted in an overshoot vasodilatation during infusion of insulin. Administration of tyramine induced only a plateau vasoconstrictor phase; the FBFi: FBFc ratio decreased by 49+/-6% before and 63+/-5% during infusion of insulin (P < 0.01). After cessation of the tyramine infusions, vasoconstriction slowly and only partially recovered, which was not affected by infusion of insulin. No time-dependency was observed for the repeated infusions of agonist. Infusion of insulin significantly reduced the apparent concentrations of norepinephrine and tyramine at which half maximal effect occurs (EC50). Dilatation with isoproterenol or sodium nitroprusside beforehand dose-dependently also reduced the EC50 of norepinephrine, with a correlation coefficient of 0.613 (P < 0.001) for relationship between individual EC50 values and baseline flows. CONCLUSIONS: Vasoconstriction induced by exogenous or endogenous norepinephrine is augmented by a high concentration of insulin. This augmentation is not time-dependent This augmentation is, however, an unspecific effect insofar as other vasodilators also enhance norepinephrine-induced vasoconstriction. The finding that hyperinsulinemia stimulates norepinephrine's vasoconstrictor effect implies that these two growth-stimulating and vascular hypertrophy-stimulating factors may act synergistically on vascular remodeling in patients with hypertension and hyperinsulinemia.

Adult↗

PubMed1997

Prostaglandins and nitric oxide mediate insulin-induced vasodilation in the human forearm.

OBJECTIVE: To determine the involvement of prostaglandins, nitric oxide, and beta-adrenoceptor activation in insulin-induced vasodilation in the human forearm. METHODS: Fifteen normal subjects were studied. Insulin was administered into the brachial artery in the presence of saline, the cyclo-oxygenase inhibitor indomethacin (0.65 microgram/kg/min), the inhibitor of nitric oxide synthase NG-mono-methyl-L-arginine (L-NMMA, 30 micrograms/kg/min), or the non-selective beta-adrenoceptor blocker propranolol (0.2 microgram/kg/min). Forearm vascular resistance (FVR) was derived from forearm blood flow and concomitantly measured intra-arterial blood pressure. RESULTS: Insulin decreased FVR by 32 +/- 5% (P < 0.01). Both indomethacin and L-NMMA inhibited insulin-induced vasodilation, while propranolol had no effect. Single infusion of indomethacin was without effect on vascular tone, while single infusion of L-NMMA increased FVR by 81 +/- 19% (P < 0.01). CONCLUSIONS: Insulin has vasodilating properties in skeletal muscle vasculature that is mediated by increases in nitric oxide, that subsequently stimulates prostaglandin release. The latter appears to be a novel vascular action of insulin.

Adrenergic beta-Agonists↗

PubMed1997

Rapid differentiation of vaccine strains and field isolates of infectious laryngotracheitis virus by restriction fragment length polymorphism of PCR products.

A procedure was developed for differentiation of vaccine strains and field isolates of infectious laryngotracheitis virus (ILTV) by restriction fragment length polymorphism (RFLP) of DNA fragments amplified from the genome of ILTV by polymerase chain reaction (PCR). RFLP patterns of viral thymidine kinase (TK) gene, glycoprotein C (gC) gene, glycoprotein X (gX) gene and ICP4 gene amplified from different ILT viruses were compared. The results showed that the vaccine strain of tissue-culture-origin (TCO) could be readily distinguished from other ILT viruses. Moreover, two out of the four field isolates could be differentiated from vaccine strains of chicken embryo origin (CEO); but the remaining two field isolates were identical to the CEO vaccine strains. These results suggested that both vaccine-like and vaccine-unlike ILT viruses were involved in the field outbreak of this disease, and that the PCR/RFLP procedure could serve as a fast and sensitive method for the detection and differentiation of vaccine strains and field isolates of ILT viruses.

Alphaherpesvirinae↗

PubMed1997

Influence of indomethacin and L-NMMA on vascular tone and angiotensin II-induced vasoconstriction in the human forearm.

Stimulated release of vasodilator prostaglandins and nitric oxide by angiotensin II may counteract the vasoconstrictor effects of this octapeptide. We investigated the effects of inhibition of prostaglandin synthesis by indomethacin and of nitric oxide formation by NG-monomethyl-L-arginine (L-NMMA) on baseline forearm blood flow (FBF) and on angiotensin II-induced vasoconstriction in healthy subjects. For comparison, the effects of the AT1-receptor antagonist losartan on these parameters were determined. FBF was measured by venous occlusion plethysmography. Angiotensin II (0.01-10 ng/kg/min) was infused into the brachial artery, in the absence and presence of indomethacin (0.65 micrograms/kg/min; n = 8), L-NMMA (30 micrograms/kg/min; n = 5), and losartan (3 micrograms/kg/min; n = 12), respectively. Sodium nitroprusside was used to submaximally predilate the forearm vascular system. Baseline FBF remained unchanged with indomethacin and losartan, but was significantly decreased by -42 +/- 6% (mean +/- SEM) by L-NMMA. The dose-dependent angiotensin II-induced vasoconstriction was unaffected by indomethacin and L-NMMA, but was inhibited by losartan. Emax was -78 +/- 2% during control conditions, -84 +/- 3% during indomethacin (n.s.), -74 +/- 4% during L-NMMA (n.s.), and -17 +/- 6% during losartan infusion (p < 0.05). None of the interventions significantly changed the EC50 value of angiotensin II of -9.4 +/- 0.14 log M. In conclusion, in the human forearm of healthy subjects, neither endogenous angiotensin II nor cyclooxygenase-dependent prostaglandin synthesis plays a role in the genesis of vascular tone, whereas endogenous nitric oxide production does. The constrictor effects of angiotensin II are counteracted by neither stimulated release of prostaglandins nor by that of nitric oxide.

Adult↗

PubMed1997

Anterior knee pain in the military population.

Anterior knee pain in our military population consititutes a diagnostic and therapeutic problem that is not always easily solved. In recent years, a better understanding of the biomechanics of the patello-femoral joint has contributed to the successful classification and treatment of many patients. However, the cause of pain remains elusive in a significant subset of patients who show no clinical or radiographic evidence of patellar malalignment and continue to have persistent pain despite adequate physiotherapy. In this article, the classification and approach to anterior knee pain are reviewed. Emphasis is placed on dividing patients into four subsets namely; normal tracking, patellar tilt, patellar subluxation and extra-articular causes of anterior knee pain. A more rational approach to the problem can then be employed and successful rehabilitation and/or surgery can be expected.

Biomechanical Phenomena↗

PubMed1996

Plasma-induced grafted polymerization of acrylic acid and subsequent grafting of collagen onto polymer film as biomaterials.

Polyacrylic acid (pAA) was introduced onto Ar-plasma treatment silicone rubber (SR) membrane surfaces by plasma-induced grafted polymerization. Collagen (type III) was also linked with the carboxylic group of pAA grafted onto the SR surface via a carbodiimine agent to obtain a secondary structure of SR. The SR surface properties were characterized by ATR-FTIR, ESCA, contact angle, and SEM. The biocompatibility of the SR surface was evaluated by a culture of cornea epithelial (CE) cells. Subsequently, 75-450 micrograms cm-2 of pAA were obtained on the SR surfaces under different reactive conditions; 3-12 micrograms cm-2 of collagen were linked on modified surfaces of SR. Moreover, ATR-FTIR and ESCA were utilized to confirm the proceedings of these reactions. The hydrophility of the modified SR was measured by a contact angle meter. The values of contact angle for SR grafted with pAA were approximately 45-50 degrees; a 50-55 degrees contact angle on pAA-g-SR to be further linked with collagen was subsequently obtained. Moreover, the influence of surface properties toward migration, growth and attachment of CE cells on the modified surfaces was also examined. Here, untreated SR was used as a control. Experimental results indicated that the number of CE cells attached onto the controlled SR was negligible. The attachment of cells onto pAA-grafted surfaces was clearly observed and peusopoda occurred; however, cell growth was depressed. This depression may have been caused by the acid environment of the pAA-grafted membrane. Nevertheless, both cell attachment and growth onto collagen-linked surfaces were significant. In addition, the morphology of the cells attached onto this surface was considered normal for primary cells. Collagen introduced on the SR surface was not denatured, i.e the natural properties of collagen were maintained. The results obtained in this study will hopefully lead to the successful development of modified SR for clinical applications.

Acrylic Resins↗