Effect of artificial cells on hepatic function after ischemia-reperfusion injury in liver

BACKGROUND: The liver suffers from ischemia/reperfusion injury during transplantation. Reactive oxygen species generated by xanthine oxidase during reperfusion of the ischemic liver may be partially responsible for the hepatic injury. Oxygen free radicals are removed by antioxidant enzymes such as superoxide dismutase (SOD), catalase, and glutathione peroxidase. Using glutaraldehyde and lysine we constructed crosslinked hemoglobin, containing SOD and catalase, and assessed its ability to protect against ischemia/reperfusion injury during transplantation. METHODS: In contrast to the sham-operated control groups, blood was exchanged using crosslinked hemoglobin (polyHb) a PolyHb-SOD-catalase (PSC) group. After ischemia/reperfusion injury, several parameters of hepatic damage and oxygen free radicals were measured as well as microscopic examination. RESULTS: Alanine aminotransferase, aspartate aminotransferase, superoxide production, hydrogen peroxide, and malondialdehyde levels were higher among the PolyHb group than sham-operated controls. The PolyHb group revealed a few apoptotic bodies, some acute inflammatory infiltrates in the sinusoids, nuclear fragmentations, cell shrinkage, and chromatin clumping with formation of apoptotic bodies in the apoptotic cells under microscopic examination. Alanine aminotransferase, aspartate aminotransferase, superoxide production, and hydrogen peroxide levels were lower in the PSC than the PolyHb group. Hepatic structures were well preserved in the PSC group. CONCLUSIONS: Reactive oxygen species contribute to hepatic dysfunction with morphologic changes. PSC is effective to reduce hepatic damage by lowering oxygen free radical-mediated injury after ischemia/reperfusion in the liver.     

Fixation using acetabular reconstruction cage and cancellous allografts for intraoperative acetabular fractures associated with cementless acetabular component insertion

Displaced acetabular fractures that occur during insertion of cementless acetabular component are a rare but very serious complication. We report two cases that were treated successfully with the utilization of an acetabular reconstruction cage and morsellized allografts.     

Endothelial injury in peritoneal dialysis patients with ultrafiltration failure

To evaluate endothelial injury in peritoneal dialysis patients with ultrafiltration failure (UFF), we performed a modified peritoneal equilibration test utilizing 3.86% glucose in 41 patients who had been on peritoneal dialysis for longer than 4 years. Twelve patients whose net ultrafiltrate was less than 400 mL during a 4-hour exchange were assigned to the UFF group and another 29 patients to the control group. The blood levels of vWF, a marker of endothelial injury, albumin, and lipid profile were measured. The number of antihypertensive medications and amount of 3.86% solution used were higher in the UFF group than those used in the control group (p < 0.05, p < 0.001, respectively). The patients in the UFF group had a significantly higher vWF level than those in the control group (164.8 +/- 23.1% vs. 144.5 +/- 22.4%, p < 0.05). These results showed that peritoneal dialysis patients with ultrafiltration failure had more severe endothelial injury than those without.     

A retrospective study of the clinical outcomes and significant variables in the surgical treatment of temporal lobe tumor associated with intractable seizures

A retrospective study was performed assessing the preoperative evaluation, and the postoperative outcomes in 35 patients with a temporal lobe tumor with intractable seizures who were treated by our neurosurgery service between October 1995 and December 1999. The mean age of the patients at the time of surgery was 27.9 years. The period of follow-up after surgery was a mean of 33.0 months. Of the study group of 35 patients, 27 (77.1%) became completely seizure free after surgery (class I), and 2 patients (5.7%) had no more than 2 seizures per year (class II). Worthwhile seizure control was achieved in 29 patients (82.8%). There was a statistical significance between the extent of tumor resection and favorable seizure outcome (p = 0.014). The most frequent histopathological diagnoses were classic epilepsy-associated ganglioglioma in 16 (45.7%) patients and low-grade astrocytoma in 10 (28.6%) patients. Complete resection of tumor was the most significant factor in obtaining a favorable seizure outcome.     

Thimerosal decreases TRPV1 activity by oxidation of extracellular sulfhydryl residues

TRPV1, a receptor for capsaicin, plays a key role in mediating thermal and inflammatory pain. Because the modulation of ion channels by the cellular redox state is a significant determinant of channel function, we investigated the effects of sulfhydryl modification on the activity of TRPV1. Thimerosal, which oxidizes sulfhydryls, blocked the capsaicin-activated inward current (I(cap)) in cultured sensory neurons, in a reversible and dose-dependent manner, which was prevented by the co-application of the reducing agent, dithiothreitol. Among the three cysteine residues of TRPV1 that are exposed to the extracellular space, the oxidation-induced effect of thimerosal on I(cap) was blocked only by a point mutation at Cys621. These results suggest that the modification of an extracellular thiol group can alter the activity of TRPV1. Consequently, we propose that such a modulation of the redox state might regulate the physiological activity of TRPV1.     

pH-dependent elution profiles of selected proteins in HPLC having a stationary phase modified with pH-sensitive sulfonamide polymers

An approach to controlling protein interactions with silica (glass) beads grafted with pH-sensitive copolymers of a sulfonamide and N,N-dimethylacrylamide is proposed. The bead surface was modified with poly(N.N-dimethyl acrylamide-co-methacryloyl sulfadimethoxine), which exhibits hydrophobic/hydrophilic switching around pH 7.0. Phase transition in the aqueous solution, the wettability change of the modified surface and surface tension of the polymer-grafted glass surface was characterized by changes in turbidity and the dynamic contact angle as a function of pH. The discontinuous phase transition in the copolymer solution shifted to a higher pH region as the composition of sulfadimethoxine monomer (SDM) was increased. However, the transition pH in continuous wettability changes on the modified surface was not affected by polymer composition due to differences in the dynamic motion. The ionized SDM of the copolymers enhanced wettability. Therefore, the advancing contact angle of the surface decreased by 45 degrees above pH 7.0, whereas wettability at low pH values was low due to the hydrophobic surface. Elution behavior of the selected four model proteins with different pI (bovine serum albumin (pI 5.0), insulin (pI 5.3), fibrinogen (pI 6.1) and myoglobin (pI 7.1)) was investigated by using pH-sensitive copolymer-modified glass beads at four pH values (5.0, 6.0, 7.0 and 8.0). Retention time of the proteins in pH-sensitive aqueous chromatography was easily regulated by eluent pH that controls the proportion of electrostatic and hydrophobic interactions between the stationary phase and the protein. At pH 5.0, hydrophobic interaction on the deionized polymer-grafted surface is an important force in separating the proteins. However, identification of the proteins at pH 7.0 was effectively facilitated due to the electrostatic interaction between the negatively charged polymer support and positive charges on protein.     

Camptodactyly, arthropathy, coxa vara, pericarditis (CACP)syndrome: a case report

The camptodactyly-arthropathy-coxa vara-pericarditis syndrome (CACP) is characterized by congenital or early-onset camptodactyly, childhood-onset noninflammatory arthropathy associated with synovial hyperplasia. Some patients have progressive coxa vara deformity and/or noninflammatory pericardial effusion. CACP is inherited as an autosomal recessive mode and the disease gene is assigned to a 1.9-cM interval on human chromosome 1q25-31. We describe a 10-yr-old boy who has typical features of CACP without familial association.     

Association of Angiotensin-converting enzyme and angiotensinogen gene polymorphisms with preeclampsia

We tested the hypothesis that angiotensin-converting enzyme (ACE) and angiotensinogen gene polymorphism influence the incidence, development and outcome of preeclampsia. Subjects were recruited from 90 Korean patients with preeclampsia during pregnancy and 98 age-matched controls. After isolation of DNA, polymerase chain reactions (PCR) were carried out to detect polymorphism of the ACE and angiotensinogen. M235T and T174M genotypes of angiotensinogen were determined by digestion with restriction enzyme endonuclease Tth 111-I and NCo I, respectively. The frequency of DD genotype was significantly greater in preeclampsia (0.36) than in controls (0.14) (p<0.05). The frequency of D allele was 0.55 in preeclampsia and 0.40 in controls (p<0.05). There were no differences in the onset of preeclampsia and pregnancy outcomes according to the ACE genotypes. There was no difference in the frequency of a allele of angiotensinogen M235T between the groups (0.79:0.78 in preeclampsia : controls). The frequency of T allele of angiotensinogen T174M gene was slightly increased, but not significantly, in preeclampsia (0.11) than in controls (0.07). In a multivariate analysis, only ACE genotype was associated with the development of preeclampsia (beta=0.27, p=0.05). In conclusion, a molecular variant of ACE, but not angiotensinogen, gene is associated with preeclampsia in Korean women.