Potential overestimation of cognitive impairment because of hearing loss: impact of test modalities on cognitive test scores

OBJECTIVE

Hearing impairment in older adults may affect cognitive function and increase the risk of dementia. Most cognitive tests are delivered auditorily, and individuals with hearing loss may fail to hear verbal instructions. Greater listening difficulty and fatigue in acoustic conditions may impact test performance. This study aimed to examine the effect of decreased audibility on cognitive screening test performance in older adults.

METHOD

Older adults (n = 63) with different levels of hearing loss completed a standard auditory Mini-Mental State Examination test and a written version of the test.

RESULTS

Individuals with moderate to moderately severe hearing loss (41-70 dB) performed significantly better on the written (24.34 ± 4.90) than on the standard test (22.55 ± 6.25), whereas scores were not impacted for mild hearing loss (less than 40 dB).

CONCLUSION

Hearing evaluations should be included in cognitive assessment, and test performance should be carefully interpreted in individuals with hearing loss to avoid overestimating cognitive decline.

A survey of enteric organisms detected by real-time PCR assay in faeces of dogs in Western Australia

This retrospective observational study reports the enteric organisms detected in dogs in Western Australia that had a faecal PCR (fPCR) submitted to a commercial veterinary laboratory. Of 2025 fPCR results, Clostridium perfringens alpha toxin gene was most frequently detected (87.2%), followed by Campylobacter spp. (37.8%), canine parvovirus (10.5%), Giardia spp. (9.7%), Salmonella spp. (7.0%), canine enteric coronavirus (2.3%), and canine distemper virus (0.3%). C.perfringens alpha toxin gene and Campylobacter spp. were the most common organisms co-detected. There was no statistically significant seasonal variation. Further studies are required to elucidate the role these organisms play in gastrointestinal disease in dogs.

Faecal PCR panel results and clinical findings in Western Australian dogs with diarrhoea

AIM

To describe faecal PCR (fPCR) results and clinical findings of dogs seen at a university teaching hospital for diarrhoea.

DESIGN

Retrospective case series (April 2015 to July 2018).

PROCEDURE

Data were collected from the hospital electronic medical records. Data extracted included signalment, history, clinical signs, treatment, fPCR panel results, other faecal diagnostic test results and antimicrobial use.

RESULTS

One hundred and sixty-eight dogs with diarrhoea had a fPCR panel submitted. Most dogs (115, 68.5%) had diarrhoea of 3 days or less duration. Clostridium perfringens alpha toxin gene was most frequently detected (156, 92.9%) by fPCR, followed by Campylobacter spp. (55, 32.7%), canine parvovirus (CPV) (29, 17.3%), Salmonella spp. (14, 8.3%) and Giardia spp. (9, 5.4%). For the 45 dogs that had a negative point-of-care CPV test, 13 were CPV fPCR positive; some of which were adult dogs with current vaccination status. A total of 94/168 (56%) dogs received antimicrobials at some time during the treatment of diarrhoea.

CONCLUSION

Faecal PCR panels can identify dogs with enteric organisms in their faeces that traditional faecal diagnostics may miss, thus contributing additional information to the diagnostic process. Nonetheless, fPCR results should be interpreted in light of the clinical findings, and particular consideration given to avoiding inappropriate use of antimicrobials. This study highlights that testing for C. perfringens alpha toxin gene is not likely to be diagnostically helpful, and that adult dogs with diarrhoea might be identified as CPV positive with PCR testing, despite a negative point-of-care CPV test result and a current vaccination status.

Sofosbuvir plus ribavirin for the treatment of hepatitis C virus genotype 2 in Korea: What's the optimal dosage of ribavirin in real-world setting?

OBJECTIVE

This study aimed to investigate the efficacy and safety of sofosbuvir plus ribavirin for the treatment of hepatitis C virus (HCV) genotype 2 infection and to determine the optimal ribavirin dosage.

METHODS

From May 2016 to March 2017, 199 patients received sofosbuvir plus ribavirin treatment for HCV genotype 2 infection at four centers in Jeollanam-do Province, Korea. After excluding patients lost to follow-up and those with insufficient data, we retrospectively assessed the data for 194 patients. The treatment efficacy and safety of sofosbuvir plus ribavirin were evaluated.

RESULTS

A sustained virological response was achieved in 189 patients (intention-to-treat [ITT] 97.4%; per protocol [PP]: 99.5%, both at 12 and 24 weeks) whose average ribavirin dosage was 937.1 mg/day. The most frequent adverse event was anemia (17.5%), and its incidence significantly increased (P < 0.001) with a higher ribavirin dosage per body weight. Discontinuation of ribavirin or dosage reduction occurred in 27 (14.2%). The ribavirin dosage reduction rate increased at a dosage of >15 mg/kg (area under the receiver operating characteristic curve 0.652, 95% confidence interval [CI] 0.54-0.76, P = 0.01). Multivariate analysis showed that age ≥70 years, with liver cirrhosis, and female gender were associated with ribavirin dosage reduction.

CONCLUSIONS

Remarkable outcomes were attained in patients with HCV genotype 2 infection treated with sofosbuvir plus ribavirin. Age ≥70 years, with liver cirrhosis, and female gender were associated with ribavirin dosage reduction. Thus, sustained virological response can be achieved with <1000 mg of ribavirin, with an optimal dosage of 15 mg/kg.

Chronic Hepatitis B Infection Is Significantly Associated with Chronic Kidney Disease: a Population-based, Matched Case-control Study

BACKGROUND

Hepatitis B virus (HBV) infection leads to hepatic and extrahepatic manifestations including chronic kidney disease (CKD). However, the association between HBV and CKD is not clear. This study investigated the association between chronic HBV infection and CKD in a nationwide multicenter study.

METHODS

A total of 265,086 subjects who underwent health-check examinations in 33 hospitals from January 2015 to December 2015 were enrolled. HBV surface antigen (HBsAg) positive cases (n = 10,048), and age- and gender-matched HBsAg negative controls (n = 40,192) were identified. CKD was defined as a glomerular filtration rate (GFR) < 60 mL/min/1.73 m² or proteinuria as at least grade 2+ of urine protein.

RESULTS

HBsAg positive cases showed a significantly higher prevalence of GFR < 60 mL/min/1.73 m² (3.3%), and proteinuria (18.9%) than that of the controls (2.6%, P < 0.001, and 14.1%, P < 0.001, respectively). In the multivariate analysis, HBsAg positivity was an independent factor associated with GFR < 60 mL/min/1.73 m² along with age, blood levels of albumin, bilirubin, anemia, and hemoglobin A1c (HbA1c). Likewise, HBsAg positivity was an independent factor for proteinuria along with age, male, blood levels of bilirubin, protein, albumin, and HbA1c. A subgroup analysis showed that HBsAg positive men but not women had a significantly increased risk for GFR < 60 mL/min/1.73 m².

CONCLUSION

Chronic HBV infection was significantly associated with a GFR < 60 mL/min/1.73 m² and proteinuria (≥ 2+). Therefore, clinical concern about CKD in chronic HBV infected patients, especially in male, is warranted.

Comparison of efficacy and safety between endoscopic submucosal dissection and transanal endoscopic microsurgery for the treatment of rectal tumor

BACKGROUND/AIM

To compare the treatment efficacy and safety between endoscopic submucosal dissection (ESD) and transanal endoscopic microsurgery (TEM) for the treatment of rectal epithelial tumors, including large adenoma, cancer, and subepithelial tumors (SET).

PATIENTS AND METHODS

We conducted a retrospective analysis of the medical records of 71 patients with rectal tumors who were treated with ESD (48 patients) or TEM (23 patients) from January 2013 to December 2015. The patient group comprised 56 patients with epithelial tumors and 15 patients with SET. Treatment efficacy such as en bloc resection, procedure time, local recurrence, hospital stay, additional procedure rate, and safety between the treatment groups were evaluated and analyzed.

RESULTS

There were no significant differences in tumor size, location, macroscopic appearance, and histological depth between ESD and TEM groups. For ESD compared to TEM in rectal epithelial tumors, en bloc resection rates were 95% vs. 93.7% and R0 resection rates were 92.5% vs. 87.5% (P = 0.617); in rectal SET, en bloc resection rates were 100% vs. 100% and R0 resection rates were 87% vs. 85% (P = 0.91). The procedure time was 71.5 ± 51.3 min vs. 105.6 ± 28.2 min (P = 0.016) for epithelial tumors and 32.13 ± 13.4 min vs. 80.71 ± 18.35 min (P = 0.00) for SET, respectively. Hospital stay was 4.3 ± 1.2 days vs. 5.8 ± 1.8 days (P = 0.001) for epithelial tumors and 4.1 ± 4.1 days vs. 5.5 ± 2 days (P = 0.42) for rectal SET, respectively. There were no significant differences between recurrence rates, additional procedure rates, and complications in the two groups.

CONCLUSIONS

ESD and TEM are both effective and safe for the treatment of rectal epithelial tumors and SET because of favorable R0 resection rates and recurrence rates. However, the ESD group showed shorter procedure times and hospital stays than the TEM group. Therefore, ESD should be considered more preferentially than TEM in the treatment of large rectal epithelial tumors and SET.

Prostanoid EP3 receptor agonist sulprostone enhances pacemaker activity of colonic interstitial cells of Cajal

EP receptor activation by PGE2 regulates gastrointestinal motility by modulating smooth muscle contractility. Interstitial cells of Cajal (ICCs) are pacemaker cells that regulate smooth muscle activity. We aimed to determine effects of the EP3 receptor agonist sulprostone on pacemaker potentials in colonic ICCs. We performed a whole cell patch clamp, RT-PCR, and Ca²⁺ imaging in cultured ICCs from mouse colon. Sulprostone depolarized the membrane and increased pacemaker frequency. EP3 receptor antagonist blocked these sulprostone-induced effects. EP3 receptors were expressed in ANO1-positive ICCs. Phospholipase C inhibitor or Ca²⁺-ATPase inhibitor from the endoplasmic reticulum blocked the sulprostone-induced effects and sulprostone increased intracellular Ca²⁺ ([Ca²⁺]_i) oscillations. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blockers also suppressed the sulprostone-induced effects. Sulprostone enhanced pacemaker activity through EP3 receptors by activating HCN channels via the [Ca²⁺]_i release pathway. Therefore, EP3 receptor activation in ICCs may modulate colonic motility and could be a therapeutic target for enhancing colonic GI motility.

Coffee consumption is associated with lower serum aminotransferases in the general Korean population and in those at high risk for hepatic disease

BACKGROUND AND OBJECTIVES

The favourable effects of coffee on liver enzymes have been reported worldwide. This study investigated the association between coffee consumption and serum aminotransferase concentration in Korean adults.

METHODS AND STUDY DESIGN

Data were obtained from the fourth and fifth Korea National Health and Nutrition Examination Surveys. Elevated alanine aminotransferase (ALT) and aspartate aminotransferase (AST) concentration were defined as >30 IU/L for men and >19 IU/L for women. The risk of elevated ALT and AST according to general characteristics and frequency of coffee consumption were tested by chi-square tests and multiple logistic regression analyses.

RESULTS

The prevalence of elevated ALT was 27.4%, 27.8%, and 26.9% in subjects who drank <1, 1, and >=2 times/day, respectively. The proportions of individuals with elevated AST were 32.5%, 33.1%, and 26.7% in subjects who drank <1, 1, and >=2 times/day, respectively. The aORs for elevated ALT and AST were significantly lower in subjects who drank >=2 times of coffee/day than in those who drank <1 time/day (ALT: aOR=0.86, 95% CI=0.79-0.94; AST: aOR=0.83, 95% CI=0.76-0.91). In subgroup analysis, consumption of >=2 times/day was associated with lower ORs for elevated ALT in the high-risk group overall and in the viral hepatitis and obesity subgroups, respectively. In sensitivity analysis, reduced frequency of coffee consumption was associated with an increased risk for elevated liver enzymes, although an association between coffee consumption and elevated ALT was not observed in women or current smokers.

CONCLUSIONS

Higher coffee consumption was associated with lower risk of elevated aminotransferase concentration in Korean adults.

The Correlation of Endoscopic Findings and Clinical Features in Korean Patients with Scrub Typhus: A Cohort Study

Scrub typhus is an infectious disease caused by Orientia tsutsugamushi-induced systemic vasculitis, but the involvement of the gastrointestinal tract and the endoscopic findings associated with scrub typhus are not well understood. We performed a prospective study and recommend performing esophagogastroduodenoscopy (EGD) for all possible scrub typhus patients, regardless of gastrointestinal symptoms. Gastrointestinal symptoms, endoscopic findings and clinical severity based on organ involvement and ICU admission were analyzed. Gastrointestinal symptoms occurred in up to 76.4% of scrub typhus patients. The major endoscopic findings were ulcers (43/127, 33.9%). Interestingly, 7.1% (9/127) of the patients presented with esophageal candidiasis. There was no correlation between the presence or absence of gastrointestinal symptoms and the endoscopic grade (P = 0.995). However, there was a positive correlation between the clinical severity and the endoscopic findings (P = 0.001). Sixty-three percent of the patients presented with erosion or ulcers on prospectively performed endoscopic evaluations, irrespective of gastrointestinal symptoms. Gastrointestinal symptoms did not reflect the need for endoscopy. Scrub typhus patients could have significant endoscopic abnormalities even in the absence of gastrointestinal symptoms.

Regulatory Roles of Endogenous Mitogen-Activated Protein Kinases and Tyrosine Kinases in the Pacemaker Activity of Colonic Interstitial Cells of Cajal

BACKGROUND AND PURPOSE

Mitogen-activated protein (MAP) and tyrosine kinases play an important role in regulating smooth muscle contraction of the gastrointestinal (GI) tract. Interstitial cells of Cajal (ICCs) are pacemaker cells that regulate GI smooth muscle activity. Thus, the role of MAP and tyrosine kinases on the pacemaker potentials of colonic ICCs was investigated.

METHODS

Cultured ICCs were prepared from mice colons, and their pacemaker potentials were recorded using whole-cell patch clamping.

RESULTS

In current-clamping mode, colonic ICCs displayed spontaneous pacemaker potentials. SB203580 (a p38 MAP kinase inhibitor), SP600125 (a c-jun NH2-terminal kinase (JNK) inhibitor), genistein and herbimycin A (tyrosine kinase inhibitors) blocked the generation of pacemaker potentials. However, PD98059 (a p42/44 MAP kinase inhibitor) had no effects on pacemaker potentials. LY-294002 (phosphoinositide 3-kinase inhibitor) also reduced the pacemaker potential frequency but calphostin C and chelerythrine (protein kinase C inhibitors) had no effects. However, PD98059, SB203589, SP600125, genistein, herbimycin A, LY-294002, and calphostin C had no effect on normal pacemaker activity in small intestinal ICCs.

CONCLUSIONS

Endogenous p38 MAP kinases, JNKs, tyrosine kinases, and PI3-kinases participate in the generation of pacemaker potentials in colonic ICCs but not in ICCs of the small intestine.

Real time observation of ZnO nanostructure formation via the solid-vapor and solid-solid-vapor mechanisms

We report in situ transmission electron microscopy studies of the formation of ZnO nanostructures--nanoscale depressions, nanoholes, nanoribbons, and nanosheets--and the phase stability and kinetics of Au catalysts on ZnO. During annealing, the ZnO layer produces hexagonally shaped, vertical nanoscale depressions, which increase in size along the 〈 0001 〉 growth direction through preferential dissociation from the {101[combining macron]0} facet and which subsequently form hexagonal islands at their six-fold junctions. Real time observations of the annealing of Au deposited on ZnO show that the catalysts remain solid up to 900 °C, an observation that has implications regarding ZnO nanowire growth via the vapor-solid-solid mechanism (VSS). The Au also creates hexagonal nanoscale holes only at the location of solid Au catalysts, via the solid-solid-vapor (SSV) mechanism. Importantly, coarsening of the Au particles is negligible due to limited Au diffusion on the side facets of the nanoscale depressions, suggesting an approach to the growth of uniform hybrid nanowires with control over both diameter and location. Furthermore, we directly monitor the evolution of the transformation of a nanoribbon into a nanosheet with {101[combining macron]0} facets. This process takes place through a periodic, kinetic roughening transition of the surface, which is controlled by the kinetic competition between surface growth and the transfer of evaporated gases. In total, these observations give new insights into multiple growth processes occurring in this important materials system.

Peritonsillar Involvement in Pyoderma Gangrenosum associated with Ulcerative Colitis

Peritonsillar abscess is a common deep throat infection. Early diagnosis and prompt, appropriate management of a peritonsillar abscess prevents mortality. A 45-year-old woman on steroids for an ulcerative colitis (UC) exacerbation presented with sore throat and multiple skin ulcers on her left forearm and right foot. Computed tomography of the neck revealed a peritonsillar abscess. Gram staining and culture of the abscess were negative, and a skin biopsy suggested pyoderma gangrenosum (PG). The final diagnosis was peritonsillar involvement of steroid-refractory PG-associated UC. The patient showed a complete response to infliximab. Here, we report a case of successful infliximab treatment for peritonsillar involvement of steroid-refractory PG-associated UC.

A nationwide seroepidemiology of hepatitis C virus infection in South Korea

BACKGROUND & AIMS

The aim of this study was to reveal nationwide seroprevalence of HCV infection in South Korea by a large-scale survey.

METHODS

From January to December 2009, a total of 291 314 adults underwent health check-up in 29 centres nationwide. The data concerning anti-HCV antibody and biochemical tests were obtained from all participants. Among subjects with positive anti-HCV, such data as HCV RNA, genotypes and treatment detail were additionally analysed.

RESULTS

Using an estimated 2009 population of Korea, the age, sex and area-adjusted anti-HCV positive rate was 0.78%. Anti-HCV prevalence in female patients (0.83%) was higher than that in male patients (0.75%). Gradual increase in anti-HCV positivity was observed, from 0.34% in those aged 20-29 years to 2.31% in those >70 years. The age- and sex-adjusted anti-HCV prevalence varied in different areas, being higher in Busan and Jeonnam (1.53-2.07%), mid-level in Seoul and surrounding districts (0.50-0.61%) and lower in Jeju (0.23%). The comparative analysis of laboratory variables between anti-HCV (+) and anti-HCV (-) group revealed significantly higher levels of alanine aminotransferase and lower levels of serum lipids in anti-HCV (+) group. Among 1 718 anti-HCV positive subjects, serum HCV RNA was measured only in 478 people, of whom 268 (56.1%) patients had detectable HCV RNA in serum. Among 50 patients for whom assessment of response to antiviral therapy was feasible, overall sustained virological response was achieved in 84% of patients.

CONCLUSION

The prevalence of HCV infection is low in South Korea. Studies to analyse risk factors are warranted to reduce HCV infection.

A comparative study of hepatitis caused by scrub typhus and viral hepatitis A in South Korea

We compared clinical features and laboratory findings of 104 patients with hepatitis A and 197 patients with scrub typhus. Nausea, vomiting, abdominal pain, hepatomegaly, and jaundice were common in patient with hepatitis A, and fever and headache were significantly more common in patients with scrub typhus. At presentation, an alanine aminotransferase (ALT) level ≥ 500 U/L was observed in 1% of scrub typhus patients and in 87.5% of hepatitis A patients (P < 0.001). A bilirubin level ≥ 1.3 mg/dL was observed in 16.8% of scrub typhus patients and 90.4% of hepatitis A patients. The ALT:lactate dehydrogenase ratio was ≤ 5 in 97.4% of the patients with scrub typhus and > 5 in 95.2% of those with hepatitis A (P < 0.001). Fever, headache, rash, and eschar are findings that indicate scrub typhus. An ALT level ≥ 500 U/L (adjusted odds ratio = 0.011) a bilirubin level ≥ 1.3 (adjusted odds ratio = 0.024), an ALT:lactate dehydrogenase ratio > 5, and hepatomegaly are indications of viral hepatitis A.

Monte carlo simulations of tau proteins: effect of phosphorylation

We perform Monte Carlo simulations of tau proteins bound to a cylinder that mimics a microtubule (MT), and then study them in solution. Tau protein binds to a highly anionic MT surface to stabilize the cylindrical structure of MT. The negatively charged tail domain floats away from the anionic MT surface while positively charged tau segments localize near the MT surface. Monte Carlo simulations demonstrate that, in 3RS tau isoform (which has three imperfect repeats (R) short (S) isoform), amino acids are more condensed near a highly charged interface compared to 4RL isoform (which has four imperfect repeats (R) long (L) isoform). In 4RL isoform, amino acids in tail domain stay mostly apart from the MT surface. In the bulk solution, dephosphorylated taus are separated due to Coulomb repulsion between similarly charged isoforms. Moderate phosphorylation of 3RS isoform decreases average intermolecular distance between dephosphorylated and phosphorylated taus and lead to their overlap. Further phosphorylation does not change noticeably the intermolecular distances.

Lamellar phase coexistence induced by electrostatic interactions

Membranes containing highly charged biomolecules can have a minimal free-energy state at small separations that originates in the strongly correlated electrostatic interactions mediated by counterions. This phenomenon can lead to a condensed, lamellar phase of charged membranes that coexists in thermodynamic equilibrium with a very dilute membrane phase. Although the dilute phase is mostly water, entropy dictates that this phase must contain some membranes and counterions. Thus, electrostatics alone can give rise to the coexistence of a condensed and an unbound lamellar phase. We use numerical simulations to predict the nature of this coexistence when the charge density of the membrane is large, for the case of multivalent counterions and for a membrane charge that is characteristic of biomolecules. We also investigate the effects of counterion size and salt on the two coexisting phases. With increasing salt concentration, we predict that electrostatic screening by salt can destroy the phase separation.

Duct-to-duct biliary reconstructions and complications in 100 living donor liver transplantations

OBJECTIVE

We evaluated the risk factors for biliary complications and surgical procedures for duct-to-duct reconstructions in adult living donor liver transplantation (LDLT).

PATIENTS AND METHODS

From February 2005 to March 2008, we performed 100 cases of adult LDLT with duct-to-duct biliary reconstruction, using 64 right lobe grafts, 33 left lobe grafts, and 3 right lateral grafts. We employed 4 types of duct-to-duct procedures: all interrupted 6-0 Prolene suture (group 1, n = 9); continuous posterior and interrupted anterior wall 6-0 Prolene suture (group 2, n = 49); all continuous 7-0 Prolene suture (group 3, n = 26); and all continuous 7-0 Prolene suture with external stent (group 4, n = 16). Biliary complications were defined as an anastomosis stricture or a leakage.

RESULTS

Thirty-four patients experienced biliary complications during the follow-up period (median, 27 months). The incidence of stricture was 27% and that of leakage, 8%. There were no perioperative, intraoperative, or anatomic risk factors for biliary complications, except the type of duct-to-duct procedure. Group 1 and 2 patients showed higher incidences of biliary strictures than groups 3 and 4 (43.1% vs 4.7%; P = .00). Group 3 patients experienced a higher incidence of bile leakage than the other groups (23.1% vs 2.7%; P = .004).

CONCLUSIONS

The type of biliary reconstruction is a factor affecting biliary complications following duct-to-duct anastomosis in LDLT. Duct-to-duct biliary anastomosis with 7-0 monofilament suture and a small external stent is a feasible procedure in LDLT that significantly reduces the incidence of biliary complications.

Auxiliary partial orthotopic living donor liver transplantation in a patient with Wilson's disease: a case report

A patient with end-stage liver cirrhosis and neurological disorder due to Wilson's disease (WD) underwent auxiliary partial orthotopic liver transplantation (APOLT) using a living donor. He first visited our institute complaining of hand tremor, which was diagnosed as WD. Despite medical therapy, hepatic impairment progressed toward portal hypertensive complications. He was considered a suitable candidate for living donor-related liver transplantation. However, because of the impossibility of mobilization of the lateral section due to severe splenomegaly at the time of the recipient operation, we performed an APOLT using a right lobe graft. After transplantation, he suffered hepatic vein stenosis and biliary stenosis, receiving interventional therapy. The remnant native liver volume decreased, and the volume of the graft increased serially after transplantation. At the time of reporting, the patient had a normal working life with normal serum ceruloplasmin level and without neurologic problems at 26 months posttransplantation. APOLT may be a therapeutic option for patients with WD.

Strong-coupling electrostatics in the presence of dielectric inhomogeneities

We study the strong-coupling (SC) interaction between two like-charged membranes of finite thickness embedded in a medium of higher dielectric constant. A generalized SC theory is applied along with extensive Monte Carlo simulations to study the image charge effects induced by multiple dielectric discontinuities in this system. These effects lead to strong counterion crowding in the central region of the intersurface space upon increasing the solvent-membrane dielectric mismatch and change the membrane interactions from attractive to repulsive at small separations. These features agree quantitatively with the SC theory at elevated couplings or dielectric mismatch where the correlation hole around counterions is larger than the thickness of the central counterion layer.

[The effect of proton pump inhibitor on healing of post-esophageal variceal ligation ulcers]

BACKGROUND/AIMS

Esophageal variceal ligation (EVL) is the most preferable method for controlling variceal bleeding. However, EVL is associated with complications such as hemorrhage, chest pain, dysphagia, and odynophagia due to post-EVL ulcers in the esophageal mucosa. The aim of this study was to assess the effect of proton pump inhibitor (PPI), pantoprazole on the healing of post-EVL ulcers.

METHODS

Forty seven patients were randomly allocated into PPI group and control group. Patients in PPI group received 40 mg of pantoprazole intravenously for 3 days after EVL, then 40 mg of oral pantoprazole for 11 days consecutively. Control patients received intravenous and oral placebo. Endoscopic examinations were performed twice at 7+/-2 days and 14+/-2 days after EVL respectively. Clinical outcomes include the size of ulcers, symptoms reported by patients; chest pain, dysphagia, and odynophagia.

RESULTS

Forty seven patients completed the 7 days protocol (PPI/control; 25/22), and twenty six patients completed the 14 days protocol (PPI/control; 16/10). Post-EVL ulcers in PPI group were significantly smaller than those in control group (7 days; 98.7 mm2/119.4 m2, 14 days; 32.3 m2/43.8 m2, p<0.01). No difference was observed between two the groups with respect to summations of symptom scores (p> 0.05). Nineteen patients (PPI/control; 9/10) did not complete the 14 days protocol due to patients' refusal and adverse outcomes, such as hepatic failure and sepsis with bleeding from post-EVL ulcer occurred in two patients of control group.

CONCLUSIONS

PPI treatment following EVL may be effective in healing post-EVL ulcer.

Effects of dielectric discontinuities on two charged plates

Counterions in a biological system are charged in water and interact with charged macroions, which are generally made up of hydrocarbons. The dielectric difference between water and the hydrocarbon substrates occurs naturally, and may greatly affect the electrostatic properties of biological systems. Particularly for a slab geometry, bulk counterions that are dissolved in water are driven to the midplane of the slab because of their repulsive interaction with their image charges. The pressure between two charged plates becomes less repulsive since the low dielectric constant of the hydrocarbon substrate creates stronger association between counterions and surface charges as compared to the case of no dielectric discontinuity.

Temperature effect on the transport dynamics of a small molecule through a liposome bilayer

An ion having hydrophobic parts can directly transport through the liposome bilayer without an ion channel and its transport mechanism can be explained by the free-volume theory. This was confirmed by investigating the temperature effect on the transport dynamics of organic cations through anionic liposome bilayers made of unsaturated and saturated lipids by using optical second-harmonic generation (SHG) technique. This study provides useful information to design practical temperature-controlled drug delivery systems.

Effect of orbital rotation and mixing on the optical properties of orthorhombic RMnO3 (R=La, Pr, Nd, Gd, and Tb)

We investigated the ab-plane absorption spectra of RMnO3 (R=La, Pr, Nd, Gd, and Tb) thin films. As the ionic radius of the R ion decreases, we observed a drastic suppression of the 2 eV peak, i.e., the intersite optical transition between spin- and orbital-aligned states across the Mott gap. We found that, in addition to orbital rotation, orbital mixing in the orbital-ordered state should play an important role in the suppression of 2 eV peak. We also found that the spectral weight of 2 eV peak is proportional to the A-type antiferromagnetic ordering temperature, which suggests that the magnetic interaction should be sensitively coupled to the orbital degree of freedom.

Interaction between two inhomogeneously charged parallel surfaces in the strong coupling regime

The counterion density profile and pressure between two inhomogenously charged parallel plates are analyzed analytically and numerically in the strong-coupling regime. Point charges are used and the surface charges are immobile. It is found that when the surface charge distribution is inhomogeneous, the charge coupling effect becomes stronger, the counterion spatial distribution is more localized toward the plate surfaces, and, thus, the pressure between two plates becomes lower than in the case when the surface charge distribution is homogeneous.

[Effects of tamoxifen on the voltage-dependent ionic currents in mouse colonic smooth muscle cells]

BACKGROUND/AIMS

Tamoxifen is a widely used anticancer drug for breast cancer with frequent gastrointestinal side effects. Changes in gastrointestinal motility is associated with altered activities of membrane ion channels. Ion channels have important role in regulating membrane potential and cell excitability. This study was performed to investigate the effects of tamoxifen on the membrane ionic currents in colonic smooth muscle cells.

METHODS

Murine colonic smooth muscle cells were isolated from the proximal colon using collagenase, and the membrane currents were recorded using a whole-cell patch clamp technique.

RESULTS

Two types of voltage-dependent K(+) currents were recorded (A-type and delayed rectifier K(+) currents). Tamoxifen inhibited both types of voltage-dependent K(+) currents in a dose-dependent manner. However, tamoxifen did not change the half-inactivation potential and the recovery time of voltage-dependent K(+) currents. Chelerythrine, a protein kinase C inhibitor or phorbol 12, 13-dibutyrate, a protein kinase C activator did not affect the voltage-dependent K(+) currents. Guanosine 5'-O-(2-thio-diphosphate) did not affect the tamoxifen-induced inhibition of voltage-dependent K(+) currents. Tamoxifen inhibited voltage-dependent Ca(2+) currents completely in whole-test ranges.

CONCLUSIONS

These results suggest that tamoxifen can alter various membrane ionic currents in smooth muscle cells and cause some adverse effects on the gastrointestinal motility.

ESHAP plus G-CSF as an effective peripheral blood progenitor cell mobilization regimen in pretreated non-Hodgkin's lymphoma: comparison with high-dose cyclophosphamide plus G-CSF

The ESHAP (etoposide, methylprednisolone, high-dose cytarabine, and cisplatin) regimen has been shown to be effective as an active salvage therapy for lymphoma. Mobilizing stem cells following ESHAP should decrease time to transplantation by making separate mobilizing chemotherapy (MC) unnecessary, while controlling a patient's lymphoma. We therefore assessed the mobilization potential of ESHAP plus G-CSF in 26 patients (ESHAP group) with non-Hodgkin's lymphoma (NHL) and compared these results with those of 24 patients with NHL who received high-dose (4 g/m2l) cyclophosphamide (HDCY) as MC (HDCY group). The age, sex, and radiotherapy to the axial skeleton were well matched between groups, but the number of patients with poor mobilization predictors was higher in the ESHAP group. Significantly higher numbers of CD34+ cells (x 10(6)/kg) (17.1+/-18.8 vs 5.8+/-5.0, P=0.03) and apheresis day 1 CD34+ cells (x 10(6)/kg) (5.5+/-6.6 vs 1.7+/-2.0, P=0.014) were collected from the ESHAP group than from the HDCY group, and the number of patients who achieved an optimal CD34+ cell target of 5 x 10(6)/kg was higher in the ESHAP group (81 vs 50%, P=0.022). Log-rank test revealed that time to target peripheral blood progenitor cell collection (> or =5 x 10(6)/kg) was shorter in the ESHAP group (P=0.007). These results indicate that ESHAP plus G-CSF is an excellent mobilization regimen in patients with relapsed and poor-risk aggressive NHL.

Optical-spectroscopic detection of spin-exchange interaction pyrochlore molybdates

Optical spectroscopy was used to determine nearest-neighbor spin correlations in pyrochlore molybdates R2Mo2O7 (R=Y, Sm, and Nd), which exhibit ferromagnetic metal to spin-glass insulator transition as the R ion size decreases. Using an analysis based on the orbitally degenerate Hubbard model, we could estimate important physical parameters, such as the effective on-site Coulomb energy U(eff) and the Hund rule exchange coupling J(H). We demonstrated experimentally and theoretically that the effective superexchange interaction between the Mo ions depends on J(H)/U(eff), which determines the phase boundary of the magnetic ground states.

[Characterization of pacemaking currents in cultured interstitial cells of Cajal from mice small intestine]

BACKGROUND/AIMS

Gastrointestinal motility is initiated by the periodic generation of slow waves. Interstitial cells of Cajal (ICC) are pacemaker cells that generate slow waves and drive spontaneous mechanical contractions of the gastrointestinal smooth muscle. Slow waves generate the periodic activation of spontaneous inward currents (pacemaker currents). The aim of this study was to investigate the characterization of pacemaker currents of ICC.

METHODS

The ICC in mice small intestine were cultured with stem cell factor for 2 days, and then we recorded pacemaker currents and slow waves using a whole-cell patch clamp technique.

RESULTS

Under voltage clamp at -80 mV of holding potential, ICC generated pacemaker currents. Tetrodotoxin and nifedipine did not affect on the pacemaker currents. In addition, tetraethylammonium, 4-aminopyridine and glibenclamide did not affect on the pacemaker currents. The reduction of external Na+ concentrations inhibited pacemaker currents. Moreover, these currents were completely abolished in the external Ca2+-free condition. Gadolinium and flufenamic acid, inhibitors of non-selective cationic currents, inhibited pacemaker currents. Thapsigargin and cyclopiazoic acid, inhibitors of Ca2+-ATPase in endoplasmic reticulum, abolished pacemaker currents. Carbachol depolarized membrane potential and increased inward currents.

CONCLUSIONS

These results suggest that pacemaker currents are mediated by the activation of non-selective cation channel and become a target of neurotransmitters in regulation of intestinal motility.

Long-term evaluation of mice model infected with Helicobacter pylori: focus on gastric pathology including gastric cancer

BACKGROUND

Long-term evaluation of gastric pathology after H. pylori infection is very important in order to reveal its clinical implications, since debate still exists on the gastric carcinogenesis provoked by H. pylori infection in animal models.

AIM

Either to evaluate the long-term outcome of H. pylori infection or to determine how H. pylori could provoke gastric cancer in the mice model.

METHODS

Four-week-old specific pathogen free C57BL/6 mice (n = 115) were infected with SS1, the mouse-adapted H. pylori strain. After 4, 8, 16, 24, 36, 50 and 80 weeks of bacterial infection, the H. pylori-infected mice were sacrificed.

RESULTS

After 80 weeks of infection, almost all the H. pylori-infected mice developed hyperplastic gastritis, but did not show any evidence of gastric adenoma, dysplasia or carcinoma. PCNA positive cells were most abundant after 50 weeks and tended to decrease thereafter up to 80 weeks, whereas apoptosis began to be noted 8 weeks after H. pylori infection, showing 7-8 apoptotic cells/high power field, and tending to increase as time passed. Normally observed neutral mucin decreased during the experiment, showing the most marked decrease 50 weeks after H. pylori infection. In contrast, acidic mucin was noted from 50 weeks after infection.

CONCLUSION

The SS1-infected mouse seems to be a suitable animal model for H. pylori-related research, and H. pylori itself does not induce gastric cancer in normal wild-type mouse model following long-term exposure, which could be explained by the balance that exists between cell proliferation and apoptosis.

Observation of surface and bulk phase transitions in nematic liquid crystals

The behaviour of liquid crystal (LC) molecules near a surface is of both fundamental and technological interest: it gives rise to various surface phase-transition and wetting phenomena, and surface-induced ordering of the LC molecules is integral to the operation of LC displays. Here we report the observation of a pure isotropic-nematic (IN) surface phase transition-clearly separated from the bulk IN transition-in a nematic LC on a substrate. Differences in phase behaviour between surface and bulk are expected, but have hitherto proved difficult to distinguish, owing in part to the close proximity of their transition temperatures. We have overcome these difficulties by using a mixture of nematic LCs: small, surface-induced composition variations lead to complete separation of the surface and bulk transitions, which we then study independently as a function of substrate and applied magnetic field. We find the surface IN transition to be of first order on surfaces with a weak anchoring energy and continuous on surfaces with a strong anchoring. We show that the presence of high magnetic fields does not change the surface IN transition temperature, whereas the bulk IN transition temperature increases with field. We attribute this to the interaction energy between the surface and bulk phases, which is tuned by magnetic-field-induced order in the surface-wetting layer.

Spin-orbital pattern dependent polaron absorption in manganites

We systematically investigated optical properties of Nd1-xSrxMnO3 single crystals ( x = 0.40, 0.50, 0.55, and 0.65). They are similar in their spin-orbital (SO) disordered states at room temperature. At low temperature, the crystals enter into various SO ordered states, i.e., F-, CE-, A-, and C-type orderings, and their mid-infrared absorptions become quite different. The remarkable variation can be explained by polaron dynamics which depend on the ordering patterns. This SO pattern dependent polaron model can also explain the pseudo CE-type ordering case, demonstrating that this scheme can explain the carrier dynamics in complex SO configurations.

Expression of multidrug resistance-associated protein1,P-glycoprotein, and thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection

Both 5-fluorouracil and doxorubicin are commonly used agents in chemotherapy of gastric cancer in adjuvant setting as well as metastatic disease. In a variety of malignancies, high expression of multidrug resistance-associated protein1 and P-glycoprotein has been associated with resistance to doxorubicin, whereas 5-fluorouracil resistance has correlated with the level of thymidylate synthase expression. We evaluated the expression of multidrug resistance-associated protein1, P-glycoprotein, and thymidylate synthase using immunohistochemistry in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection and investigated the association between their expression and clinicopathologic characteristics including prognosis of the patients. While high expression (> or =5% of tumour cells positive) of multidrug resistance-associated protein1 and P-glycoprotein was observed in 70 patients (68%) and 42 patients (41%), respectively, 65 patients (63%) had primary tumours with high expression (> or =25% of tumour cells positive) of thymidylate synthase. There was a significant association between multidrug resistance-associated protein1 and P-glycoprotein expression (P<0.0001) as well as P-glycoprotein and thymidylate synthase expression (P<0.0001). High multidrug resistance-associated protein1 and P-glycoprotein expressions were associated with well and moderately differentiated histology (P<0.0001 and P=0.03, respectively) and intestinal type (P<0.0001 and P=0.009, respectively). High multidrug resistance-associated protein1 expression correlated with lymph node metastasis (P=0.037), advanced stage (P=0.015), and older age (P=0.021). Five-year disease-free survival and overall survival of total patients were 55.2% and 56.2%, respectively, with a median follow-up of 68 months. There were no significant differences in disease-free survival and overall survival according to the expression of multidrug resistance-associated protein1 (P=0.902 and P=0.975, respectively), P-glycoprotein (P=0.987 and P=0.955, respectively), and thymidylate synthase (P=0.604 and P=0.802, respectively). Concurrent high expression of these proteins (high multidrug resistance-associated protein1/P-glycoprotein, high multidrug resistance-associated protein1/thymidylate synthase, high P-glycoprotein/thymidylate synthase) did not correlate with disease-free survival or overall survival. Even high expression of all three proteins was not associated with poor disease-free survival (P=0.919) and overall survival (P=0.852). In conclusion, high expression of multidrug resistance-associated protein1, P-glycoprotein, and thymidylate synthase did not predict poor prognosis of gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy. A larger study including patients treated with surgical resection alone would be necessary.

Conditional loss of TGF-beta signalling leads to increased susceptibility to gastrointestinal carcinogenesis in mice

BACKGROUND

Downregulation of TGF-beta receptors is implicated in colon cancer development. Inactivation of either of the two transmembrane serine/threonine kinases, TGF-beta1 types I/II receptors, is now implicated in carcinogenesis, especially gastrointestinal carcinogenesis.

METHODS

We generated transgenic mice, called pS2-dnRII or ITF-dnRII, of which the dominant negative mutant of the TGF-beta type II receptor was expressed under the control of tissue-specific promoters, the pS2 promoter for stomach and ITF for intestine. They were either infected with H.pylori (ATCC 43504 strain, CagA+ and VacA+) or administered with azoxymethane to determine the significance of loss of TGF-beta signalling in gastrointestinal carcinogenesis.

RESULTS

Gastric adenocarcinoma developed in pS2-dnRII mice, whereas only chronic active gastritis was noted in wild-type littermates after 36 weeks of H.pylori infection. Mice lacking in TGF-beta signalling specifically in the stomach showed a significantly higher proliferation cell nuclear antigen-labelling index when infected with H.pylori than wild-type littermates (P < 0.01). Development of colonic aberrant crypt foci was provoked in mice by intraperitoneal injections of azoxymethane, and ITF-dnRII mice showed significantly higher incidences of ACF and colon cancers than wild-type littermates.

CONCLUSIONS

Maintaining normal TGF-beta signalling in the gastrointestinal tract seems to be important either for preventing abnormal mucosal proliferation, or for suppressing or retarding carcinogenesis.

Reconsideration of intermittent synchronization in coupled chaotic pendula

We reinvestigate the intermittent synchronization phenomenon of coupled chaotic pendula that has recently been a controversy. We propose a simple numerical scheme by which one can easily determine whether the observed synchronization is a numerical artifact of computer analysis or not. By using this scheme, for certain coupling strength regime, we find that the average time taken for synchronization linearly depends on the precision of calculations. According to Longa et al.'s criterion for synchronization, this implies that the observed synchronization is genuine.

Development of expression systems for the production of recombinant human serum albumin using the MOX promoter in Hansenula polymorpha DL-1

To optimize the secretory expression of recombinant human serum albumin (HSA) under the control of methanol oxidase (MOX) promoter in the methylotrophic yeast Hansenula polymorpha DL-1, we analyzed several parameters affecting the expression of HSA from the MOX promoter. Removal of the 5'-untranslated region derived from HSA cDNA in the expression cassette led to at least a fivefold improvement of HSA expression efficiency at the translational level. With the optimized expression cassette, the gene dosage effect on HSA expression was abolished and thus, a single copy of the expression vector integrated into the MOX locus became sufficient for the maximal expression of HSA. Northern blot analysis revealed that the levels of HSA transcript did not increase any further upon increasing copy number. The mox-disrupted (mox Delta) transformant was constructed, in which the genomic MOX gene was transplaced with the HSA expression cassette, to examine the effect of the methanol oxidase-deficient phenotype of the host on HSA expression. The mox Delta transformant showed higher levels of HSA production in shake-flask cultures than the MOX wild-type transformant, especially at low concentrations of methanol and a twofold higher specific HSA production rate in fed-batch fermentation with an abrupt induction mode. The native prepro signal sequence of HSA secreted in H. polymorpha was correctly processed and the mature recombinant protein had a pI value identical to that of the authentic HSA. Our results suggest that the H. polymorpha expression systems developed in this study are suitable for large-scale production of recombinant albumin.

The experiences of hilar skeletonization for the treatment of locally advanced proximal bile duct cancer

BACKGROUND/AIMS

Because proximal bile duct cancer easily involves the surrounding tissue, tumor cells often remain after apparent macroscopically complete radical resection. We evaluated the effect of resective modality of these tumors on prognosis and the effect of postoperative radiotherapy on survival of patients with microscopic residual tumor following local resection in locally advanced proximal bile duct cancer.

METHODOLOGY

From November, 1990 to October, 1993, 45 proximal bile duct cancer patients who received local excision were entered onto this prospective, nonrandomized study. The patients were divided into three groups after operation, 16 patients with curative resection; 15 noncurative resection; and 14 nonresection. Patients who had positive lymph nodes or microscopic cancer cells in resection margin or adjacent major vessels, were treated with postoperative external radiotherapy, 5040 cGy for 40 days.

RESULTS

The overall 1-, 2-, and 5-year survival of the patients was 62.2%, 24.4%, and 15.6%, respectively. The overall mean and median survival of patients was 24.1 +/- 3.98 (mean +/- SE) months and 13 +/- 0.74 months, respectively. Survival rates between resection and nonresection showed a statistically significant difference (P < 0.05). However, survival rates between curative resection and noncurative resection with postoperative radiotherapy were not statistically significant (P > 0.05).

CONCLUSIONS

The resection is the treatment of choice for locally advanced proximal bile duct cancer, if resectable and the noncurative resection followed by postoperative external radiotherapy may be beneficial to the patients with locally advanced proximal bile duct cancer.

Glomus tumor of the stomach: CT findings

We present the radiologic findings of gastric glomus tumors in two patients, in whom upper gastrointestinal series and computed tomography (CT) were primarily used for diagnosis. The diagnosis was surgically confirmed. Contrast-enhanced CT showed peripheral nodular or homogeneous strong enhancement in the arterial phase and prolonged enhancement in the delayed phase.

Expression of thymidylate synthase in gastric cancer patients treated with 5-fluorouracil and doxorubicin-based adjuvant chemotherapy after curative resection

We evaluated the expression of thymidylate synthase (TS) in locally advanced gastric cancer patients treated with adjuvant chemotherapy after curative resection and investigated the association between TS expression and clinicopathologic characteristics including prognosis of the patients. TS expression was evaluated by immunohistochemical staining using TS106 monoclonal antibody in 103 locally advanced gastric cancer patients (stage IB-IV) who underwent 5-fluorouracil (5-FU) and doxorubicin-based adjuvant chemotherapy after curative resection. 65 patients (63%) had primary tumours with high TS expression (> or = 25% of tumour cells positive), and 38 patients (37%) demonstrated low TS expression (< 25% of tumour cells positive or no staining). High TS expression was associated with male gender (P = 0.002), poorly differentiated histology (P = 0.015), and mixed type in Lauren's classification (P = 0.027). There were no statistically significant differences in 4-year disease-free survival (60.0% vs. 57.2%, P = 0.548) and overall survival (59.6% vs. 59.3%, P = 0.792) between high-TS group and low-TS group. In conclusion, although high TS expression was associated with poorly differentiated histology and mixed type in Lauren's classification, it did not predict poor disease-free and overall survival in gastric cancer patients treated with 5-FU and doxorubicin-based adjuvant chemotherapy after curative resection. Further prospective studies including the evaluation of other biological markers associated with the resistance to 5-FU and doxorubicin are necessary.

Perigastric lymph node status can be a simple prognostic parameter in patients with gastric cancer

BACKGROUND/AIMS

The number of metastatic lymph nodes has been a significant prognostic factor after curative resection of gastric cancer and adopted as a new UICC classification of nodal stages in gastric cancer. The extent of lymphadenectomy is another significant factor but has been fiercely debated. Regardless of the type of lymphadenectomy, perigastric lymph node dissection is always carried out. In this study, we examined whether the number of metastatic perigastric nodes can be a prognostic indicator of gastric cancer.

METHODOLOGY

For the purpose of evaluating perigastric lymph node status, a retrospective study was carried out with 760 patients who underwent curative gastric resection from June 1994 to November 1998.

RESULTS

The 4-year cumulative survival rate was 64% and the survival rate decreased significantly when the number of positive perigastric nodes exceeded 3. Comparing with the patients having 0-2 positive perigastric nodes, patients whose metastatic perigastric lymph nodes exceeded 3 or more exhibited deeper tumor invasion, larger tumor size and older age. Multivariate analysis identified the number of positive perigastric nodes, together with depth of tumor invasion, as the strongest independent prognostic factors for survival.

CONCLUSIONS

We suggest that the number of metastatic perigastric nodes can be used as a simple prognostic parameter in patients with gastric cancer and that intensive follow-up and adjuvant chemotherapy should be recommended for the patients with more than 3 metastatic perigastric nodes.

Production and characterization of immortalized rat hepatocytes secreting hepatocyte growth factor/scatter factor

BACKGROUND/AIMS

Hepatocyte transplantation is a recently attractive field in the treatment of liver failure and enzyme-deficient diseases. However, procurement of sufficient quantities of hepatocytes is almost impossible. We attempted to create a hepatocyte cell line that could be used for hepatocyte transplantation.

METHODOLOGY

L2A2 is a conditionally immortalized rat hepatocyte cell line produced by transfection of temperature-sensitive simian virus T antigen to the hepatocytes in the Lewis rat. Hepatocyte Growth Factor/Scatter Factor (HGF/SF)-secreting L2A2 cells, designated as SF-21, was produced by transfecting human HGF/SF cDNA into L2A2 cells.

RESULTS

This cell line was able to produce HGF/SF at the rate of 5-10 ng/10(6) cells/24 hrs, and the recombinant HGF/SF was of the expected size and was functionally active in that it could scatter Madin-Darby canine kidney cells. The SF-21 cells grew faster than its parental cell clone, and survived and proliferated at 37 degrees C in vitro. Also, the SF-21 cells were able to survive and proliferate when transplanted into the spleen of syngeneic rat, and expressed glucose-6-phosphatase.

CONCLUSIONS

These HGF/SF-secreting hepatocytes can be used as a model system to test a feasibility of using genetically engineered hepatocyte cell line for hepatocyte transplantation in the rat.

Alignment of liquid crystals on a photosensitive substrate studied by surface optical second-harmonic generation

The adsorption kinetics and orientational ordering of 4(')-n-octyl-4-cyanobiphenyl (8CB) liquid crystal films evaporated onto photosensitive poly(vinyl-cinnamate) (PVCN) substrates were investigated by surface optical second-harmonic generation. The adsorption rate of the first monolayer decreases with increasing degree of photochemical modification of the polymer. The in-plane orientational anisotropy of the 8CB films grown on unidirectionally photopolymerized PVCN substrates is considerably lower than the intrinsic surface orientational anisotropy of these substrates, which can explain the generally found weak surface anchoring of liquid crystals on PVCN alignment layers.

Intraportal insulin therapy after partial hepatectomy for hepatoma patients with insulinopenia

BACKGROUND/AIMS

This prospective study was carried out in order to assess the role of intraportal insulin infusion after partial hepatectomy in hepatoma patients with insulinopenia.

METHODOLOGY

Of the 38 patients who underwent hepatic resection for hepatocellular carcinoma from August 1994 to August 1995, 21 patients took an oral glucose tolerance test with insulin measurement preoperatively. Five patients were treated postoperatively with intraportal insulin infusion, as follows: A 16-gauge catheter was inserted into a reopened umbilical vein and fixed in place by a few absorbable stitches. Regular insulin was administered just after the operation at the rate of 2 units/hour for 2-3 weeks. Blood glucose levels were maintained between 150 and 200 mg/dL. Arterial ketone body ratio was used in monitoring the function of the liver during the perioperative periods.

RESULTS

Ten patients (47.6%) were found to be insulinopenic. In the insulin therapy group (n = 5), the arterial ketone body ratio of 3 patients recovered within a few hours after the operation, and that of the remaining 2 patients recovered on the 1st postoperative day. But in the control group (n = 5), none of the 5 cases had an arterial ketone body ratio of more than 0.7 on the day of operation. The arterial ketone body ratio returned to normal on the 1st postoperative day in 2 cases, on the 2nd postoperative day in 1 case, and on the 5th day in 1 case. The arterial ketone body ratio recovery time was shorter in the intraportal insulin therapy group than in the control group (P = 0.042).

CONCLUSIONS

Intraportal insulin infusion after hepatectomy via the reopened umbilical vein may be a very simple and safe means of promoting recovery of remnant liver function after hepatectomy in hepatoma patients with insulinopenia.

Relation between the risk of gallstone pancreatitis and characteristics of gallstone in Korea

BACKGROUND/AIMS

Pancreatitis is a serious complication of patients with gallstones. However, risk factors of gallstone pancreatitis were unpredictable until recently. In Korea, characteristics of gallstones are different from Western countries. The present study was designed to determine differences in the risk of gallstone pancreatitis and characteristics of gallstones in Korean patients.

METHODOLOGY

Clinical data were collected on patients undergoing laparoscopic cholecystectomy. The physical characteristics of gallstones recovered at surgery were also recorded. Patients with gallstone pancreatitis were compared with patients who had uncomplicated biliary pain.

RESULTS

In a logistic regression model, acute gallstone pancreatitis was associated with a stone diameter of less than 5 mm (odds ratio: 3.3695; P = 0.0352) and with stone number of more than 20 (odds ratio: 3.8686; P = 0.0361). No other variable, including pigment stone, age, and sex, remained statistically significant in the adjusted analysis (P > 0.05).

CONCLUSIONS

Patients with at least 1 gallstone smaller than 5 mm in diameter and stone number more than 20 each have a more than 3-fold increased risk of presenting with acute gallstone pancreatitis. The composition of gallstones, especially pigment stones, was not an important risk factor in gallstone pancreatitis in Korean patients with stones having a different composition than those from Western countries.

Systematic analysis of the effects of hepatocyte transplantation on rats with acute liver failure

BACKGROUND/AIMS

Acute liver failure either after liver resection or as part of underlying liver disease is still associated with high mortality. Hepatocyte transplantation in various forms has attracted attention recently. However, none of those reports have investigated the thorough and systematic analysis of effect of hepatocyte transplantation on acute liver failure induced by 90% hepatectomy. Therefore, we investigated systematic analysis of effect of hepatocyte transplantation on rats with acute liver failure.

METHODOLOGY

Male Sprague-Dawley rats were used. Group I rats (n = 26) received intrasplenic injection of 2 x 10(7) hepatocytes in 0.3 mL Dulbecco's modified Eagle's medium (DMEM) 24 hours prior to 90% hepatectomy. Group II rats (n = 24) received intrasplenic injection of DMEM only. Twenty-two rats from group I and 20 from group II were observed for the determination of survival time. The remaining 8 (4/each group) rats were used to assess the liver function and regeneration.

RESULTS

The hepatocyte bearing spleen revealed active glucose-6-phosphatase activity. In group I rats, the survival was longer and that group had more long-term survivors than those of group II controls. In group I, there was significant increase in the ratio of weight of remnant liver lobes to body weight. At 24 hours after hepatectomy, group I rats had improved biochemical parameters compared to those of group II rats.

CONCLUSIONS

In rats with acute liver failure, intrasplenic hepatocyte transplantation acts as a bridge to support experimental rats from acute liver failure to liver regeneration, prolong survival in rats with acute liver failure and improve biochemical parameters.

Expression of vascular endothelial growth factor in otitis media

Increased vascular permeability and endothelial cell growth are important in the pathogenesis of otitis media with effusion (OME) and the vascular endothelial growth factor (VEGF) is known to play an important role in the increased vascular permeability and angiogenesis. To date, at least five isoforms of the VEGF family have been identified as VEGF transcripts, encoding polypeptides of 206, 189, 165, 145 and 121, but their physiological roles are unclear. The purpose of this study was to investigate the expression of VEGF, in both endotoxin-induced OME of the rat and human otitis media. We instilled endotoxin and saline as a control into the middle ear cavity of the rat. Middle ear mucosa were taken at 0 h, 1 h, 3 h, 6 h, 12 h, 1 day, 3 days, 7 days and 14 days and the expression of VEGF mRNA and VEGF protein was evaluated using semi-quantitative RT-PCR and immunohistochemistry. Expression of VEGF164 mRNA and VEGF120 mRNA was first identified 1 h after endotoxin instillation and was dramatically increased over the period 6 h-1 day and then progressively decreased by day 7. The level of expression of VEGF120 mRNA was slightly higher than that of VEGF164 mRNA and that of VEGF164 mRNA was much higher than that of VEGF188 mRNA. Immunostaining revealed expression of VEGF during 6 h to day 3 and its expression was localized to ciliated cells and some inflammatory cells. We also performed RT-PCRs of cDNA from middle ear fluids of 8 human OME patients and middle ear mucosa of 4 chronic otitis media patients for the identification of VEGF mRNA expression. VEGF121 mRNA was highly expressed in all samples compared with VEGF165 mRNA. These results suggest that VEGF may be primarily responsible for increased vascular permeability and endothelial cell growth in OME and that VEGF seems to play a significant role in the pathogenesis of OME.

Significant correlation between serum level of hepatocyte growth factor and progression of gastric carcinoma

Hepatocyte growth factor (HGF) can promote proliferation of many types of tumor cells including gastric cancer cells. To study the role of HGF in the progression of gastric carcinoma, HGF levels were measured by an enzyme immunoassay (EIA) system in sera of gastric cancer patients and followed up the levels after the operation. The mean serum HGF level in 212 healthy control subjects, 140 patients with primary gastric cancer, and 13 patients with recurrent gastric cancer were 0.199 +/- 0.073, 0.325 +/- 0.209, and 0.578 +/- 0.258 ng/ml, respectively. The increase of the levels was significantly correlated with the progression of tumor stage. The levels decreased to normal levels 1 month after curative resection of the tumors. However, the levels did not decrease significantly in nonresected cases. During the follow-up of the patients for several months, the level was significantly increased in recurrent gastric cancer patients, whereas there was no increase in nonrecurrent patients. In conclusion, the serum HGF levels significantly correlated with the aggressiveness of the tumors, suggesting an important role of HGF in the progression of gastric carcinoma.