Hemangioma of the right ventricular outflow tract

Obstruction of the right ventricular outflow tract by a primary cardiac tumor is rare. Six cases of right ventricular outflow tract obstruction by a primary cardiac hemangioma have been reported; all but one were detected before the age of 25 years. In this report, we review the literature and describe what we believe to be only the second reported case of right ventricular outflow tract obstruction produced by a cardiac hemangioma that presented in late adulthood.

Caspase inhibitor z-VAD-FMK inhibits keratocyte apoptosis, but promotes keratocyte necrosis, after corneal epithelial scrape

The purpose of this study was to determine whether the caspase inhibitor z-VAD-FMK could be applied topically prior to epithelial scrape injury to inhibit keratocyte apoptosis. Rabbit corneas were treated with z-VAD-FMK or vehicle alone prior to epithelial scrape injury. Cell fate was analysed at 4 hr after epithelial scrape using quantitative TUNEL assay, propidium iodide staining, and transmission electron microscopy. Less stained anterior stromal keratocytes were detected with the quantitative TUNEL assay in corneas pre-treated with z-VAD-FMK than in corneas pretreated with vehicle at 4 hr after epithelial scrape. This difference appeared to be confirmed by propidium iodide staining of keratocyte nuclei. It was observed that fewer nuclei were stained with propidium iodide in the DMSO vehicle treated corneas compared to the z-VAD-FMK treated corneas. Analysis of corneas with transmission electron microscopy, however, indicated that many anterior stromal keratocytes in corneas pretreated with z-VAD-FMK, but not vehicle, had cell morphologic changes more consistent with necrosis. Although pretreatment of corneas with the caspase inhibitor z-VAD-FMK inhibited keratocyte apoptosis detected with the TUNEL assay, transmission electron microscopy revealed that many anterior stromal keratocytes in z-VAD-FMK-treated corneas instead died by necrosis. Thus, z-VAD-FMK is unlikely to be useful to modulate corneal would healing through inhibition of keratocyte apoptosis induced by epithelial injury. The TUNEL assay should not be used to monitor cell fate without confirmation using analyses that also detect necrosis.

Acceleration of DNA strand exchange by polycation comb-type copolymer

Polycation comb-type copolymers which are composed of poly(L-lysine) backbone and dextran graft chain (PLL-graft-Dex) accelerated DNA duplex and triplex formation and stabilized under physiologically relevant condition remarkably. In this study, we have examined the ability of polycation copolymer in promoting strand exchange between duplex DNA and its complementary single-stranded DNA. It was demonstrated that the strand exchange rate was considerably accelerated by the polycation comb-type copolymer.

Polymorphisms of N-acetyltransferase 2, glutathione S-transferase mu and theta genes as risk factors of bladder cancer in relation to asthma and tuberculosis

PURPOSE

We investigated whether the polymorphisms of N-acetyltransferase 2 (NAT2), glutathione S-transferase-mu (GSTM1) and glutathione S-transferase-theta (GSTT1) genes were risk factors of bladder cancer among Korean people in relation to other risk factors.

MATERIALS AND METHODS

In this case-control investigation of 113 patients with primary bladder cancer and 221 control subjects, we compared the association of bladder cancer with genetic polymorphisms of NAT2, GSTM1 and GSTT1, demographic characteristics, smoking status, and medical histories in a molecular epidemiological way.

RESULTS

The risk of bladder cancer was significantly increased in patients with a medical history of tuberculosis (OR 3.61, 95% CI 1.57 to 8.26) and bronchial asthma (OR 4.15, 95% CI 1.61 to 10.75), while smoking history turned out to be insignificant. GSTM1 null genotype was a significant risk factor of bladder cancer (OR 1.81, 95% CI 1.12 to 2.93). On the other hand, slow acetylator and GSTT1 genotypes were insignificant. Also, we could not find any association between GSTM1, GSTT1, slow acetylator genotypes and bladder cancer risk among smokers. The rapid acetylator, GSTM1 null and GSTT1 null genotypes with a medical history of asthma or tuberculosis combinations were significant risk factors in Korean subjects.

CONCLUSIONS

Among Korean subjects, GSTM1 null genotype was a significant risk factor for bladder cancer. The reason why bronchial asthma and tuberculosis are risk factors in Korean subjects is yet unknown, but a variety of factors, including enzyme activities for detoxification, medication for these diseases and immunological background might be involved.

Modulation of TNF-alpha-induced apoptosis in corneal fibroblasts by transcription factor NF-kappaB

PURPOSE

Previous studies have suggested no role for tumor necrosis factor (TNF)-alpha in the modulation of apoptosis in corneal fibroblasts. However, recent investigations have demonstrated that nuclear factor (NF)-kappaB activation by TNF-alpha mediates negative apoptotic effects that must be blocked to unmask the apoptotic effects of TNF-alpha in vitro. The purpose of this study was to investigate the role of transcription factor NF-kappaB in the suppression of TNF-alpha-induced apoptosis of corneal fibroblasts.

METHODS

mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) and RNase protection assay. Proteins were detected by immunocytochemistry and immunoprecipitation with Western blot analysis. Cell death was evaluated by trypan blue exclusion assay in corneal fibroblasts treated with TNF-alpha in presence or absence of the specific inhibitor of NF-kappaB activation, SN50, actinomycin D, or actinomycin D with dexamethasone, ketorolac tromethamine, or diclofenac sodium. Apoptosis was monitored by trypan blue exclusion, colorimetric cell assay, CPP32 activation assay, DNA fragmentation assay, and transmission electron microscopy. NF-KB activation was monitored using electrophoretic gel shift assay.

RESULTS

TNF-alpha, TNF receptor (R)I, and TNFRII mRNAs were detected in all three cultured corneal cell types and in ex vivo corneal epithelium using RT-PCR. TNF-alpha mRNA was also detected in ex vivo corneal epithelium, corneal epithelial cells, and stromal fibroblasts with the RNase protection assay. TNF-alpha, TNFRI, and TNFRII proteins were detected by immunocytochemistry in all three major corneal cell types in human corneal tissue. TNF-alpha protein was also detected in ex vivo corneal epithelium, primary corneal epithelial cells, and primary stromal fibroblasts using immunoprecipitation and Western blot analysis. TNF-alpha stimulated corneal fibroblast cell death when NF-kappaB activation was blocked with actinomycin D or SN50. Enhanced cell death was noted with dexamethasone, ketorolac tromethamine, or diclofenac sodium when used in the presence, but not in the absence, of actinomycin D. A gel shift assay revealed induction of NF-KB by TNF-alpha and suppression of induction in the presence of actinomycin D or SN50, but not by the control peptide SN50M.

CONCLUSIONS

The TNF-alpha receptor system is expressed in the cornea, and NF-kappaB activation is an important regulator of TNF-alpha-mediated corneal fibroblast apoptosis. Nonsteroidal anti-inflammatory agents or corticosteroids may potentiate corneal fibroblast apoptosis in response to cytokine stimulation.

Increase of [Ca(2+)]i and release of arachidonic acid via activation of M2 receptor coupled to Gi and rho proteins in oesophageal muscle

We have previously shown that acetylcholine-induced contraction of oesophageal circular muscle depends on activation of phosphatidylcholine selective phospholipase C and D, which result in formation of diacylglycerol, and of phospholipase 2 which produces arachidonic acid. Diacylglycerol and arachidonic acid interact synergistically to activate protein kinase C. We have therefore investigated the relationship between cytosolic Ca(2+) and activation of phospholipase A(2) in response to acetylcholine-induced stimulation, by measuring the intracellular free Ca(2+) ([Ca(2+)]i), muscle tension, and [3H] arachidonic acid release. Acetylcholine-induced contraction was associated with increased [Ca(2+)]i and arachidonic acid release in a dose-dependent manner. In Ca(2+)-free medium, acetylcholine did not produce contraction, [Ca(2+)]i increase, and arachidonic acid release. In contrast, after depletion of Ca(2+) stores by thapsigargin (3 microM), acetylcholine caused a normal contraction, [Ca(2+)]i increase and arachidonic acid release. The increase in [Ca(2+)]i and arachidonic acid release were attenuated by the M2 receptor antagonist methoctramine, but not by the M3 receptor antagonist p-fluoro-hexahydro siladifenidol. Increase in [Ca(2+)]i and arachidonic acid release by acetylcholine were inhibited by pertussis toxin and C3 toxin. These findings indicate that contraction and arachidonic acid release are mediated through muscarinic M2 coupled to Gi or rho protein activation and Ca(2+) influx. Acetylcholine-induced contraction and the associated increase in [Ca(2+)]i and release of arachidonic acid were completely reduced by the combination treatment with a phospholipase A(2) inhibitor dimethyleicosadienoic acid and a phospholipase D inhibitor pCMB. They increased by the action of the inhibitor of diacylglycerol kinase R59949, whereas they decreased by a protein kinase C inhibitor chelerythrine. These data suggest that in oesophageal circular muscle acetylcholine-induced [Ca(2+)]i increase and arachidonic acid release are mediated through activation of M2 receptor coupled to Gi or rho protein, resulting in the activation of phospholipase A(2) and phospholipase D to activate protein kinase C.

Defective keratocyte apoptosis in response to epithelial injury in stat 1 null mice

Defects in apoptosis have been noted in signal transducer and activator of transcription (Stat) 1-null cells in vitro. The purpose of this study was to analyse the keratocyte apoptosis response that occurs in vivo in response to corneal epithelial injury in Stat 1null compared with control mice and to determine whether Stat 1null corneal fibroblasts have a defective response to death receptor activation in vitro. Corneal epithelial scrape injuries were performed in Stat 1-null and wild-type mice. Keratocyte apoptosis was monitored with the quantitative TUNEL assay and confirmed using transmission electron microscopy. Corneal fibroblast apoptosis in response to tumor necrosis factor (TNF) alpha, with and without inhibitors of nuclear factor kappa B (NF-kappaB) activation, was monitored using DNA laddering and the methylene blue assay. Significantly less keratocyte apoptosis was noted in Stat 1-null mice compared with wild-type controls. TNF alpha-induced apoptosis only occurred in wild-type mice in the presence of inhibitors of NF-kappaB activation. Corneal fibroblast TNF alpha-induced apoptosis was defective in Stat 1null corneal fibroblasts whether NF-kappaB activation was blocked or not. Stat 1 has an important role in the keratocyte apoptosis that occurs in response to corneal epithelial injury. Previous studies suggest that the defect is due to a lack of constitutive expression of caspases. This study demonstrates that this defect in apoptosis in Stat 1-null mice is present in vivo in Stat 1-null mice and suggests that Stat 1 could be a therapeutic target for transient inhibition of keratocyte apoptosis to modulate corneal wound healing.

Collagen-to-smooth muscle ratio helps prediction of prognosis after pyeloplasty

PURPOSE

We quantitatively evaluated the collagen-to-smooth muscle tissue matrix ratio in ureteropelvic junction obstruction, and compared the ratio with the degree of obstruction, patient age and postoperative renal recovery.

MATERIALS AND METHODS

We analyzed histological sections from 65 patients with ureteropelvic junction obstruction and 6 normal controls. Morphological and functional grading systems were adapted to determine the degree of renal obstruction. To examine smooth muscle and collagen tissue, sections were stained using Masson's trichrome. Two distinct populations of collagen versus smooth muscle were identified and the tissue matrix ratio was calculated by color image analysis.

RESULTS

The mean tissue matrix ratio plus or minus standard deviation was 1.32+/-0.79 in all patients with ureteropelvic junction obstruction but only 0.30+/-0.10 in normal controls (p <0.0001). It appeared that the lower the tissue matrix ratio, the better the improvement in postoperative hydronephrosis (r = -0.50, p = 0.0001). Better recovery of renal function after pyeloplasty was observed with a decrease in the tissue matrix ratio (r = -0.43, p = 0.0004). We divided patients according to the tissue matrix ratio into groups 1--ratio 1 or less, 2--greater than 1 to 1.5 and 3--greater than 1.5 to determine a more detailed and clinically applicable correlation of tissue matrix ratio with postoperative renal functional changes. Better improvement in postoperative renal function was observed in group 1 than in group 3 (p = 0.002). Also, the tissue matrix ratio increased with patient age (r = 0.33, p = 0.007).

CONCLUSIONS

Since our data represent an objective and quantitative parameter associated with ureteropelvic junction obstruction, we believe that our findings may help to predict the prognosis after pyeloplasty.

Clinical analysis of central islands after laser in situ keratomileusis

PURPOSE

To analyze the incidence and clinical characteristics of central islands after laser in situ keratomileusis (LASIK) and to elucidate factors associated with their formation.

SETTING

Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

METHODS

Laser in situ keratomileusis was performed in 103 eyes of 61 patients with myopia ranging from -4.0 to -13.5 diopters (D) using the Hansatome (Chiron) and SVS Apex Plus (version 3.2.1) excimer laser (Summit Technology) in which the anti-central-island program was implemented. After 1 week, corneal topography (Orbscan, Orbtek) was done and manifest refraction and visual acuity were measured.

RESULTS

Postoperatively, the mean uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were 0.12 and 0.06 (logMAR scale), respectively, and the mean refractive error (spherical equivalent) was 0.07 D +/- 0.76 (SD). On topographic examination, a central island was defined as an area of higher refractive power of more than 1.5 D and 2.5 mm or more in diameter. Budding or isolated central islands were observed in 12 eyes of 12 patients (11.7%). The peak, height, and area of the islands were 41.5 +/- 3.1 D, 5.6 +/- 1. 9 D, and 3.5 +/- 1.1 mm(2), respectively. In the eyes with central islands, there were statistically significant differences in the postoperative change in UCVA and BCVA (P <.05). There was no significant correlation between the occurrence of a central island and preoperative refractive error, corneal thickness, age, or in sex and correction of astigmatism (P >.05).

CONCLUSION

Despite use of the anti-central-island pretreatment program, the occurrence of central islands after LASIK was significant, as in photorefractive keratectomy. Further studies of the effect of central islands on surgical results and clinical progress and measures to prevent the occurrence are needed.

Involvement of progesterone in gonadotrophin-induced pituitary adenylate cyclase-activating polypeptide gene expression in pre-ovulatory follicles of rat ovary

The present study was designed to determine whether progesterone might have a role in gonadotrophin-induced pituitary adenylate cyclase-activating polypeptide (Pacap) gene expression in rat ovary. Northern blot analysis revealed that treatment of pregnant mare's serum gonadotrophin (PMSG)-primed immature rats with the progestin antagonist RU486 or an inhibitor of 3beta-hydroxysteroid dehydrogenase epostane, 1 h before HCG, resulted in a dose-dependent inhibition of the HCG-induced Pacap gene expression. In-situ hybridization demonstrated that the number of pre-ovulatory follicles expressing Pacap mRNA in their granulosa cells was greatly reduced in ovaries treated with RU486. Moreover, the suppressive effect of RU486 or epostane on the LH-induced Pacap gene expression in cultured pre-ovulatory follicles was reversed by co-treatment with the synthetic progestin R5020. We further cloned the 5'-flanking region of the rat Pacap gene and identified the presence of a consensus progesterone receptor element. When luciferase fusion genes containing Pacap gene promoter were transiently transfected into granulosa cells of pre-ovulatory follicles, luciferase activity was markedly stimulated by LH. Treatment with RU486 or epostane resulted in partial suppression of LH-stimulated PACAP promoter activity. Taken together, these results indicate that progesterone, acting through progesterone receptors, plays a role in gonadotrophin induction of Pacap gene expression in granulosa cells of pre-ovulatory follicles, and thereby may be involved in the process of ovulation.

Differential expression of receptor tyrosine kinases and Shc in fetal and adult rat fibroblasts: toward defining scarless versus scarring fibroblast phenotypes

The remarkable ability of the fetus to heal early gestation skin wounds without scarring remains poorly understood. Taking advantage of recent advances in signal transduction, the tyrosine phosphorylation patterns of fetal rat fibroblasts, representing the scarless cutaneous repair phenotype, and adult rat fibroblasts, representing scarforming phenotype, were examined whether there were inherent differences in cellular signaling. Specifically, correlation of the phosphorylation patterns with the expression levels of the signaling molecules that transmit information from the plasma membrane receptor to the nucleus was sought. By using three different cell lines of explanted fibroblasts from gestational day 13 fetal rat skin (n = 24) and 1-month-old postnatal adult rat skin (n = 3), immunoblotting was performed to compare tyrosine phosphorylation patterns. The results revealed five major protein bands of interest in fetal rat fibroblasts, but not in the adult rat fibroblasts. These phosphorylated protein bands are of interest because of their possible role in wound repair and may have the potential to regulate cellular responses to the extracellular matrix and their secondary signaling molecules. It was hypothesized that these bands represented receptor tyrosine kinases, epidermal growth factor receptor, and discoidin domain receptor 1, and their downstream adaptor protein Shc that binds receptor tyrosine kinases to transduce signals intracellularly. Furthermore, elevated expression of platelet-derived growth factor receptor-beta in adult compared with fetal fibroblasts was demonstrated, suggesting that decreased expression of certain growth factors may also be important for the scarless phenomenon to occur.

Identification of H-2K(b)-restricted T-cell epitopes within the nucleocapsid protein of Hantaan virus and establishment of cytotoxic T-cell clones

Although neutralizing antibodies against Hantaan virus (HTV) can protect hosts from viral infection, T-cell responses to HTV are also important in host defense against HTV. However, much less is known about cytotoxic T lymphocyte (CTL) responses to HTV. To identify CTL epitopes in the HTV nucleocapsid protein (NP), we selected 7 H-2K(b)-motif-fitting peptides. Of these peptides, 3 peptides (NP3, NP4, and NP7) were recognized by CTL responses derived from HTV-immunized mouse splenocytes. NP3 and NP4 peptides were also recognized by HTV-immunized splenocytes after secondary in vitro stimulation with the relevant peptide, but NP7 could not be recognized after in vitro stimulation. These results agree well with peptide immunization studies showing that peptide-specific CTL responses could be induced with NP3 and NP4 but not with NP7 peptide. Furthermore, CTL activity assay using targets, prepared to express the antigen (NP) endogenously, demonstrated that NP3 and NP4 peptides could be presented endogenously. CTL elicited with NP4 peptide retained some cross-reactivity and was difficult to long-term culture. However, NP3-elicited CTL was very specific for NP3 peptide and was stable enough to be cloned. Among many CTL lines elicited with HTV or HTV NP peptides, 6 NP3-specific CTL clones were established and have been maintained more than 2 years. All 6 CTL clones were characterized to be CD3+, CD4-, CD8+, CD25+, CD62L-, and NK1.1-, and to use TCR Vbeta6. This preferential usage of TCR Vbeta6 indicates that TCR Vbeta6 regions are important for recognition of the HTV NP3 epitope (NP221-228, SVIGFLAL) on H-2K(b) molecule. Our data demonstrate the definition of mouse CTL epitopes in HTV and the generation of HTV-specific mouse CTL clones.

High-level expression of a foreign gene by a recombinant baculovirus with an expanded host range

The usefulness of host range expanded viruses as an expressionvector system was investigated by following the expression ofthe E. coli lacZ gene. The host range expanded recombinantviruses were obtained from Sf-21 or BmN-4 cells coinfected withAutographa californica and Bombyx mori nuclearpolyhedrosis viruses. Among the host range expanded viruses,RecB-8 and RecS-B6 have similar enzyme digestion profiles butdifferent infection characteristics in cells. Therefore, tostudy the foreign gene expression efficiency of these twoviruses, we constructed recombinant viruses RecB8-LacZ andRecSB6-LacZ containing the lacZ gene instead of the polyhedringene. Also, the host range expanded recombinant AcNPV, Bac-BH,containing lacZ gene in the polyhedrin gene locus was constructedby substitution of the 0.6 kb region within the helicase gene ofBacPAK6 with that of BmNPV. beta-Galactosidase expressionefficiency by these viruses were determined and compared in Sf-21and BmN-4 cells. The result showed that Bac-BH has highexpression efficiency only in Sf-21 cells, whereas RecB8-LacZhas high expression efficiency both in Sf-21 and BmN-4 cells.Also, in BmN-4 cells, beta-galactosidase expressionefficiency of RecB8-LacZ was higher than that of recombinantBmNPV (BmK1-LacZ containing lacZ gene in polyhedrin gene locus).In addition, the expression efficiency was not correlated withvirus titer.

Restoration of thoracic kyphosis in the hypokyphotic spine: a comparison between multiple-hook and segmental pedicle screw fixation in adolescent idiopathic scoliosis

This study verified the efficacy of segmental pedicle screw fixation in restoring thoracic kyphosis in persons with hypokyphotic scoliosis. Fifty-one patients were divided into three groups by the degree of preoperative thoracic hypokyphosis and fixation method used: the hypokyphosis-hook (HH), hypokyphosis-screw (HS), and normal kyphosis-screw (NS) group. They were compared after a minimum follow-up period of 2 years. Preoperative thoracic kyphosis of 4.1 degrees +/- 8.6 degrees, 8.1 degrees +/- 5.6 degrees and 27.3 degrees +/- 9.8 degrees in the HH, HS, and NS groups were restored to 14.5 degrees +/- 10.2 degrees, 27.3 degrees +/- 11.3 degrees, and 28.3 degrees +/- 13.7 degrees, respectively. The difference between the HH and HS groups was significant (p = 0.000). The HS and the NS groups did not differ (p = 0.16). This indicates that segmental pedicle screw fixation was more effective than multiple hooks in restoring kyphosis in patients with hypokyphotic scoliosis and created kyphosis similar to that in patients without preoperative hypokyphosis.

Keratocyte apoptosis associated with keratoconus

Keratoconus is an ectatic corneal dystrophy associated with stromal thinning and disruption of Bowman's layer. The purpose of this study was to explore a possible association between keratocyte apoptosis and keratoconus. Keratocyte apoptosis was evaluated in corneas of patients with keratoconus, corneas of patients with stromal dystrophies, and normal donor corneas using the transferase-mediated dUTP-digoxigenin nick and labeling (TUNEL) assay. Keratocyte apoptosis was also studied in keratoconus and normal corneas using transmission electron microscopy. TUNEL-stained keratocytes were detected in 60% of corneas with keratoconus, but only 35% of corneas with stromal dystrophies (P =0.03). The number of TUNEL-positive keratocytes detected in the keratoconus, stromal dystrophy, and normal corneas was 7+/-1 (mean+/-standard error, range 0-20), 2+/-0. 8 (range 0-9), and 0+/-0 (range 0-0) TUNEL-positive cells per section, respectively. The differences between the keratoconus and the stromal dystrophy (P =0.0097) or the normal cornea (P =0.01) groups were statistically significant. The difference between the stromal dystrophy and normal cornea groups was not statistically significant (P =0.45). The stromal dystrophy group was included to account for surgery-associated keratocyte apoptosis. No TUNEL-stained keratocytes were detected in normal corneas. Cell morphologic changes consistent with apoptosis were detected by transmission electron microscopy (TEM) in keratocytes of keratoconus corneas, but not in keratocytes in normal corneas. Chronic keratocyte apoptosis associated with ongoing epithelial injury may link risk factors associated with keratoconus such as chronic eye rubbing, contact lens wear, or atopic eye disease. Similarly, increases that have been detected in several different degradative enzymes in keratoconus corneas could be associated with chronic keratocyte apoptosis and less than perfect control of release of intracellular contents.

Lacrimal gland HGF, KGF, and EGF mRNA levels increase after corneal epithelial wounding

PURPOSE

To evaluate the effect of corneal epithelial wounding on lacrimal gland expression of hepatocyte growth factor (HGF), keratinocyte growth factor (KGF), and epidermal growth factor (EGF) in the rabbit model.

METHODS

Rabbits had corneal epithelial scrape injuries, and the lacrimal gland was removed at different times after wounding. HGF, KGF, and EGF mRNA expression was examined by quantitative RNase protection assay. HGF, KGF, and EGF proteins were detected in rabbit lacrimal tissue using immunoprecipitation and western blot analysis.

RESULTS

HGF mRNA and EGF mRNA were significantly increased in rabbit lacrimal gland tissue within 8 hours after corneal epithelial injury. The increase in KGF mRNA expression was small and reached significance I clay after corneal injury. Lacrimal gland expression peaked at 3 days after wounding for each growth factor mRNA, the same day, on average, that the epithelial defect healed. After the peak increase in expression, there was a progressive decline in expression of each growth factor mRNA, but production was still increased compared with prewound levels. HGF protein, KGF protein, and EGF proteins were detected in rabbit lacrimal gland tissue.

CONCLUSIONS

Levels of HGF, KGF, and EGF mRNAs increase in rabbit lacrimal gland tissue in response to corneal epithelial wounding. The results of this study are consistent with the existence of a cornea-nervous system-lacrimal gland regulatory loop modulating expression of these growth factor mRNAs. The lacrimal gland is a likely source of increased HGF and EGF proteins detected in tears in previous studies.

Expression of transforming growth factor beta 1, 2, and 3 proteins in keloids

Keloids represent a pathological response to cutaneous injury, creating disfiguring scars with no known satisfactory treatment. They are characterized by an excessive accumulation of extracellular matrix, especially collagen. Transforming growth factor beta (TGF-beta) has been implicated in the pathogenesis of keloids. The three TGF-beta isoforms identified in mammals (TGF-beta1, -beta2, and -beta3), are thought to have different biological activities in wound healing. TGF-beta1 and TGF-beta2 are believed to promote fibrosis and scar formation, whereas TGF-beta3 has been shown to be either scar inducing or reducing, depending on the study. The aim of this study was to characterize expression of TGF-beta isoforms in keloids at the protein level using Western blot analysis. The authors found that TGF-beta1 and -beta2 proteins were at higher levels in keloid fibroblast cultures compared with normal human dermal fibroblast cultures. In contrast, the expression of TGF-beta3 protein was comparable in both the normal (N = 3) and keloid (N = 3) cell lines. These findings, demonstrating increased TGF-beta1 and -beta2 protein expression in keloids relative to normal human dermal fibroblasts further support the roles of TGF-beta1 and -beta2 as fibrosis-inducing cytokines.

Effect of PDGF, IL-1alpha, and BMP2/4 on corneal fibroblast chemotaxis: expression of the platelet-derived growth factor system in the cornea

PURPOSE

The purpose of this study was to examine expression of platelet-derived growth factor (PDGF) and PDGF receptors in the human cornea and to study the effects of the PDGF isotypes on proliferation and chemotaxis of human corneal fibroblasts. The effects of interleukin (IL)-1alpha, bone morphogenic protein (BMP)2, and BMP4 on chemotaxis of human corneal fibroblasts were also studied.

METHODS

mRNA expression was monitored with reverse transcription-polymerase chain reaction (RT-PCR) in primary cultured cells. Protein expression in fresh-frozen human corneal sections was studied with immunocytology. Chemotaxis was measured using a modified Boyden chamber, and proliferation was quantitated by cell counting.

RESULTS

PDGF A, PDGF B, PDGF receptor alpha, and PDGF receptor beta mRNAs were detected in corneal epithelial cells, fibroblasts, and endothelial cells in culture. The proteins were expressed in each major cell type in human corneal sections, with PDGF A and PDGF B detected at high levels in the epithelial basement membrane. PDGF, BMP2, and BMP4 had attractive chemotactic effects on corneal fibroblasts, with the PDGF BB dimer having a significantly greater positive chemotactic effect than the other PDGF isotypes. Interleukin-1alpha had a repulsive chemotactic effect on corneal fibroblasts. PDGF AA, AB, and BB stimulated proliferation of human corneal fibroblasts.

CONCLUSIONS

The PDGF growth factor receptor system is expressed in the human cornea. PDGF, BMP2, BMP4, and IL-1alpha may modulate keratocyte chemotaxis and proliferation during homeostasis and wound healing.

Comparison of Korean-American adoptees and biological children of their adoptive parents: a pilot study

This study compared a small group of Korean-American adoptees with their adoptive siblings who are biological children of the adoptive parents with respect to their psychosocial adjustment. Eighteen Korean-American adoptees were compared with nine biological children by a structured demographic, medical, clinical survey form and the Child Behavior Checklist-Parent Form (CBCL-P). The parents did not raise any more concerns about the adjustment of adopted children than their biological children. On the CBCL-P, the two groups did not differ significantly in competence T-scores, total behavioral problems, broad and T-scores and the total number of problem behaviors except for lower social competence in adopted children and a higher internalization score in biological children. In conclusion, the international adoptees, the Korean-American children have adjusted well during their early childhood after early adoption. Further studies employing a larger sample are warranted to better understand the international adoption practice.

The prognosis for control of seizures with medications in patients with MRI evidence for mesial temporal sclerosis

PURPOSE

Mesial temporal sclerosis (MTS) is the most common and important pathology in temporal lobe epilepsy (TLE), and its presence in magnetic resonance imaging (MRI) scans is strongly correlated with a successful surgical outcome. Despite the general assumption that patients with MTS respond poorly to medication, the long-term prognosis for such patients has not yet been investigated. We studied the overall clinical prognosis of patients with MTS and analyzed the factors related to the degree of medical responsiveness.

METHODS

Case patients were actively followed up at the Yonsei Epilepsy Clinic in Seoul, Korea, for >2 years. A structured interview and a thorough clinical evaluation were conducted. MRI scans, at the field strength of 1.0 or 1.5 Tesla, were performed with T1- and T2-weighted coronal and axial spin-echo images. All coronal slices were < or = 5-mm thick with no gap. Two neurologists and one radiologist determined the presence of MTS in MRIs by visual analysis.

RESULTS

The MTS group consisted of 104 patients. Of these, 26 (25%) were completely controlled with adequate therapy, and 40 (38%) were intractable, despite aggressive anticonvulsant polytherapy. The remaining 37% had their seizure frequencies reduced by > or = 50%, but were not seizure free. The age of seizure onset was significantly younger in the intractable group than in the well-controlled group. Patients with a history of febrile convulsions or with epileptiform discharges in their electroencephalogram (EEG) had poorer seizure control (p < 0.05) than those who did not. Among the 16 patients who had no previous treatment, five (31%) became seizure free, and two were intractable.

CONCLUSIONS

Not all patients with MTS are medically intractable; 25% of the patients in our study achieved complete control while receiving medication. Poor seizure control was related to an early age of seizure onset, a history of febrile convulsions, and epileptiform discharges on the EEG.

The changing molecular epidemiology and establishment of endemicity of vancomycin resistance in enterococci at one hospital over a 6-year period

The contributions of clonal spread, transfer of genetic elements, and introduction of new strains to the establishment of endemicity of vancomycin-resistant enterococci (VRE) were determined. The study took place at one hospital between 1990, when VRE were first detected, and 1996, when endemicity had become established. Isolates from 183 patients were categorized into 24 strain types by pulsed-field gel electrophoresis; the resistance genotype was determined by polymerase chain reaction. Between 1990 and 1993, 69% of patients were infected with the same vanB Enterococcus faecium strain. VanA resistance was not detected until 1993, but in 1996, the ratio of vanA to vanB was 2.2:1. Over time, 8 vanA strains were detected; a 35- or 40-kb conjugative vanA plasmid was found in 4 of the 8 strains. Clonal spread was a major factor in the establishment of endemicity. Transfer of genetic elements and introduction of new strain types were detected less often. However, these events may have been equally important evolutionarily.

A bit allocation method based on picture activity for still image coding

Bit allocation or the quantizer assignment problem is a basic and essential issue in lossy picture coding. The optimal solution for the bit allocation problem can be found by the Lagrangian method. However, it requires much computational time and memory. To reduce complexity overhead, we propose a fast scheme using a picture activity measure. Comparison among the existing activity measurement methods is presented to select the most reliable activity measure and the mapping relation between the activity value, and a quantization parameter is proposed.

Pylephlebitis associated with appendicitis

Pylephlebitis usually occurs secondary to infection in the region drained by the portal venous system. A most common antesecent focus of infection is diverticulitis and the most common blood isolate is E. coli (54%), followed by Proteus mirabilis (23%). Overall mortality is 32% and most of the patients who had died had severe sepsis prior to the initiation of antibiotic therapy. We describe a case of pylephlebitis which had appendicitis and consequent septic thrombosis of the portal vein and its branches, with dissemination of infection to the liver. The patient had recovered due to timely antibiotic treatment alone and resulted in complete resolution. Early diagnosis and treatment are basic to a favorable clinical course.

Changes in corneal morphology associated with chronic epithelial injury

PURPOSE

The purpose of this study was to evaluate the effect of chronic epithelial scrape injury on corneal morphology.

METHODS

The corneal epithelia in one eye of 8-week-old New Zealand White rabbits were scraped at weekly intervals. Central corneal thickness was measured by ultrasonic pachymetry before epithelial scrape each week. Control never wounded (C), chronic wounded with scrape the last week (W), and chronic wounded without scrape the last week (WW) corneas were processed for histologic analysis and transmission electron microscopy (TEM). The time intervals for histologic analysis were 4 (4 C, 2 W, 2 WW), 8 (4 C, 2 W, 2 WW), and 16 (7 C, 2 W, 5 WW) weeks. Histologic findings were monitored using hematoxylin and eosin staining, the TdT-dUTP terminal nick-end labeling (TUNEL) assay, and TEM.

RESULTS

Chronic wounded corneas developed marked epithelial hyperplasia and a subepithelial acellular zone. Keratocytes undergoing apoptosis were primarily detected adjacent to the acellular zone by TUNEL assay and TEM. Total central corneal thickness measured by ultrasonic pachymetry (n=7) was significantly thinner in chronically scraped eyes compared with control eyes after 8, 12, and 16 weeks (P < 0.05). Control corneas increased in total thickness over the 16 weeks of the study, but there was no significant change in total thickness of the corneas that had chronic epithelial scrape injury over this time interval. Two scraped corneas had marked decreases in total corneal thickness relative to the corneal thickness at the beginning of the study. Epithelial hyperplasia developed in all scraped corneas examined histologically after 4, 8, or 16 weeks of scraping. When central epithelial thickness measured on hematoxylin and eosin-stained sections was subtracted from the total pachymetric corneal thickness to give approximate stromal thickness, the stromal thickness was 23% lower in the chronic wounded (277+/-15 microm) compared with the unwounded (356+/-6 microm) corneas (P=0.0008) after 16 weeks of wounding.

CONCLUSIONS

Chronic epithelial injury induces stromal thinning and epithelial hyperplasia. These changes in cornea structure associated with chronic epithelial injury may have relevance to the pathophysiology of keratoconus.

Bacterial resistance to antimicrobial agents: an overview from Korea

Antimicrobial resistance of bacteria has become a worldwide problem. Available data suggest that the resistance problem is comparatively more serious in Korea. In large hospitals, the proportion of methicillin-resistant Staphylococcus aureus (MRSA) has been reported at over 70%, and of penicillin-nonsusceptible Streptococcus pneumoniae at around 70%. Infection or colonization of vancomycin-resistant enterococci has started to increase. Extended-spectrum beta-lactamase producing Escherichia coli and Klebsiella pneumoniae has become widespread and even carbapenem-resistant Pseudomonas aeruginosa has been increasing. Community-acquired pathogens such as Salmonella, Shigella and Neisseria gonorrhoeae are often resistant to various antimicrobial agents. The prevalence of resistant bacteria can lead to erroneous empirical selection of either noneffective or expensive drugs, prolonging hospitalization and higher mortality. The emergence and spread of resistant bacteria are unavoidable unless antimicrobial agents are not used at all. The high prevalence of resistant bacteria in Korea seems to be related to antibiotic usage: 1) easy availability without prescription at drug stores, 2) injudicious use in hospitals, and 3) uncontrolled use in agriculture, animal husbandry, and fisheries. Nosocomial infection is an important factor in the spread of resistant bacteria. Antimicrobial resistance problems should be regarded as the major public health concern in Korea. It is urgently required to ban the sale of antibiotics without prescription, to use antibiotics more judiciously in hospitals by intensive teaching of the principles of the use of antibiotics, and to establish better control measures of nosocomial infections. Regulation of antimicrobials for other than human use should also be required. These issues are not easy to address and require the collective action of governments, the pharmaceutical industry, health care providers, and consumers.

Bone morphogenic proteins 2 and 4 and their receptors in the adult human cornea

PURPOSE

To examine the expression of transforming growth factor family members bone morphogenic proteins 2 and 4 (BMP2, BMP4), their receptor mRNAs, and BMP2 and BMP4 proteins in the cells of the human cornea. The effects of BMP2 and BMP4 on corneal fibroblast proliferation and apoptosis were also examined.

METHODS

Reverse transcription-polymerase chain reaction, immunoprecipitation, and western blot analysis were used to examine mRNA and protein expression in cultured human corneal cells. Immunocytochemistry was applied to examine protein localization in fresh frozen human cornea cells. Stimulation and inhibition of nuclear factor-kappaB (NF-kappaB) activation was evaluated by gel shift assay. Apoptosis was examined using trypan blue exclusion, laddering of DNA, CPP32 assay, and transmission electron microscopy. Proliferation was monitored by counting cells.

RESULTS

BMP2 and BMP4 mRNAs and proteins were expressed in cultured human corneal epithelial cells, keratocytes, and corneal endothelial cells. BMP2 and BMP4 were detected in each major corneal cell type in fresh frozen human cornea. BMP receptor IA, IB, and II mRNAs were also detected in cultured human corneal epithelial cells, keratocytes, and endothelial cells. BMP2 and BMP4 stimulated activation of NF-kappaB. Actinomycin D and SN50 peptide, but not SN50M control peptide, inhibited NF-kappaB activation in response to BMP2 or BMP4. BMP2 and BMP4 stimulated apoptosis of corneal fibroblast cells when NF-kappaB activation was inhibited with the nonselective inhibitor actinomycin D or selective inhibitor SN50. The nonsteroidal anti-inflammatory agents ketorolac tromethamine and diclofenac sodium augmented the effect of BMP2 on corneal fibroblast apoptosis. BMP2 and BMP4 both stimulated proliferation of corneal fibroblast cells in the absence of inhibitors of NF-kappaB activation.

CONCLUSIONS

BMP2, BMP4, and their receptors are expressed in the cells of the adult human cornea. The functions regulated by these cytokines may include keratocyte proliferation and apoptosis.

Signal transduction in wound pharmacology

Growth factors such as TGF-beta, PDGF and FGF are thought to play important roles in wound healing. However, their biological activity and signal transduction during wound repair remain poorly understood. Growth factors are often ligands for receptor tyrosine kinase and receptor serine/threonine kinases. With recent advances in signal transduction by receptor kinases, we are beginning to understand the underlying mechanism of how growth factors may regulate cutaneous wound repair. In this paper, we will describe the pharmacological effects of growth factors on wound healing, and discuss the potential underlying signaling mechanisms. Thus, we hope to provide the basis for designing more specific therapeutics for wound healing in the near future.

Clinical courses of pure sleep epilepsies

This study aims to understand seizure control outcomes and the risk of developing new wake seizures (WS) related to the different types of pure sleep epilepsies (SE), which is important in making rational management plans. A retrospective review of the Yonsei Epilepsy Clinic Registry identified 63 patients with pure SE not belonging to any specific epileptic syndromes. They were divided into the group of generalized tonic-clonic seizures during sleep (S-GTCS : n = 21) and the group of partial epilepsies during sleep (S-PE: n = 42) on the basis of seizure phenomenology, EEG, and neuroimaging data. These patients were followed for 2 years and their clinical variables were analysed for seizure control outcomes and development of new WS. Of 21 patients with S-GTCS, 17 achieved a seizure-free outcome and only one patient developed a new WS, which was consistent with a partial-onset secondary GTCS in phenomenology. Of 42 patients with S-PE only 15 patients achieved a seizure-free outcome and 11 patients developed WS during the 2-year follow-up period. Higher baseline seizure frequency and longer duration of epilepsy were associated with a higher incidence of new WS. The results suggest that the patients with S-GTCS carry a favorable clinical course, thus driving privileges or freedom of daily activities can be conferred without delay once their seizures are well controlled. However, the seizure control outcome was poor and the development of WS was frequent in patients with recurrent S-PE.

Differences in Keratocyte Apoptosis Following Transepithelial and Laser-scrape Photorefractive Keratectomy in Rabbits

BACKGROUND

Anterior stromal keratocyte cells undergo programmed cell death (apoptosis) in response to corneal epithelial injury. Keratocyte apoptosis may be an initiator of the corneal wound healing response that includes keratocyte proliferation and activation, as well as changes to the overlying epithelium, occurring following refractive surgical procedures such as photorefractive keratectomy (PRK). This study compared the effect of laser-scrape and transepithelial PRK on keratocyte apoptosis.

METHODS

Photorefractive keratectomy was performed in both eyes of 10 New Zealand white rabbits using the Summit Apex excimer laser. Surgery was performed using transepithelial PRK in one eye and laser-scrape PRK in the other. The central cornea was analyzed at 4 hours after surgery using a quantitative TUNEL assay that detects fragmented DNA characteristic of apoptosis. Hepatocyte growth factor (HGF) production by keratocytes was detected by immunocytochemistry.

RESULTS

Average apoptotic cells per 400X microscopic field determined by 2 independent masked observers were 0.9 +/- 0.5 (scanning electron microscopy) and 0.2 +/- 0.2 in the transepithelial PRK group compared with 5.1 +/- 2.9 and 4.1 +/- 3.2 in the laser-scrape group. The difference between the two groups was statistically significant for both observers (P < .05, ANOVA). HGF was detected within keratocytes throughout the corneal stroma. Less HGF was detected in the anterior stroma in the laser-scrape group at 4 hours after surgery, consistent with more anterior keratocyte apoptosis in this group.

CONCLUSIONS

Transepithelial PRK induced less anterior keratocyte apoptosis in rabbits than laser-scrape PRK. This suggests that transepithelial PRK could be useful in preventing or minimizing refractive regression and subepithelial scarring.

The morphology of the polyhedra of a host range-expanded recombinant baculovirus and its parents

The host range-expanded recombinant baculovirus, RecB-8 was isolated from BmN-4 cells coinfected with Autographa californica and Bombyx mori nuclear polyhedrosis viruses. Its genome was compared with those of its parents by restriction endonuclease digestion and their polyhedra compared in an electron microscope. Interestingly, the polyhedra of RecB-8 were tetrahedral although the polyhedrin gene was the same as that of the BmNPV parent which has icosahedral polyhedra. Thus the morphology of the RecB-8 polyhedra resulted from host cell factors and/or another viral genome in the host cells.

Keratocyte apoptosis after corneal surgery

PURPOSE

Programmed cell death (apoptosis) is the controlled death of cells that occurs with minimal collateral damage to surrounding cells or tissue during development, homeostasis, and wound healing. The authors hypothesize the keratocyte apoptosis is an initiating factor in the wound-healing response after refractive surgical procedures. To evaluate the effects of different corneal manipulations, keratocyte apoptosis was examined qualitatively and quantitatively after traditional epithelial scrape-photorefractive keratectomy (PRK), transepithelial PRK, removal of a cap of superficial cornea using a microkeratome, production of a flap of superficial cornea with a microkeratome, and laser-assisted in situ keratomileusis (LASIK) compared with unwounded controls in rabbit corneas.

METHODS

Refractive surgical procedures or their components were performed in rabbit eyes. Keratocyte apoptosis was monitored using the terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick-end labeling assay to detect DNA fragmentation. Cellular morphologic changes were evaluated by electron microscope examination.

RESULTS

Keratocyte apoptosis was noted with each refractive procedure or corneal manipulation and was variable from eye to eye with each procedure. Transepithelial PRK was associated with the lowest levels of central corneal apoptosis, even if the stromal surface was scraped after the procedure. Keratocyte apoptosis is confined to the superficial stroma extending to a depth of approximately 50 microns to 75 microns after epithelial scrape-PRK and transepithelial PRK. Apoptosis was noted in the deeper central corneal keratocytes located anteriorly and posteriorly to the lamellar cut in LASIK.

CONCLUSIONS

There are qualitative and quantitative differences in keratocyte apoptosis between LASIK, epithelial scrape-PRK, and transepithelial PRK. Epithelial injury is an important factor modulating keratocyte apoptosis. The level and distribution of keratocyte apoptosis, along with subsequent repopulation by activated stromal keratocytes, are likely to be important determinants of corneal wound healing associated with variability and regression after PRK and LASIK. Transepithelial PRK induces low levels of keratocyte apoptosis, and, therefore, this approach may be useful for treating higher levels of myopia and for retreatment after regression.

The Effect of Topical Corticosteroids on Refractive Outcome and Corneal Haze after Photorefractive Keratectomy

BACKGROUND

The effect of topical corticosteroids after excimer laser photorefractive keratectomy (PRK) remains a matter of some controversy. Refractive effects may be different according to the amount of myopia and timing of instillation.

METHODS

Two groups of patients were studied: Study A consisted of 215 eyes (128 patients) with PRK (mean baseline myopia, -6.53 +/- 2.22 D) that received no corticosteroids (No Corticosteroid Group) unless significant regression or corneal haze appeared (Delayed Corticosteroid Group), and in Study B, we randomly assigned eyes to the Initial Corticosteroid Group (mean baseline myopia, -6.39 +/- 1.84 D) or the No/delayed Corticosteroid Group (mean baseline myopia -5.78 +/- 2.02 D). Clinical results after PRK for low-to-moderate and high myopia were compared.

RESULTS

In the first group, 70.9% (73 eyes) of moderately myopic eyes (mean, -4.56 +/- 1.10 D) belonged to the No Corticosteroid Group that had a mean refraction of -5.39 +/- 1.77 D. Delayed Corticosteroid Group eyes were more myopic (mean, -7.52 +/- 2.10 D), and showed more severe haze than those in the No Corticosteroid Group. In study B, only in high myopes with more than -6.00 D (mean, -7.76 +/- 1.15 D) did refraction and corneal haze outcomes show significant difference between the Initial Corticosteroid Group and the No/delayed Corticosteroid Group.

CONCLUSIONS

The effects of topical corticosteroids after PRK were less in moderate myopes compared to high myopes. Delayed instillation of corticosteroids did not reverse the regression or haze whereas initial instillation showed a beneficial effect on high myopes but not on moderate myopes.

Multifactorial involvement of multidrug resistance-associated [correction of resistance] protein, DNA topoisomerase II and glutathione/glutathione-S-transferase in nonP-glycoprotein-mediated multidrug resistance in human bladder cancer cells

BACKGROUND

Multiple mechanisms are important in multidrug resistance in urothelial cancers. We investigated the acquisition of a multidrug resistance phenotype in human bladder cancer cells exposed to doxorubicin.

METHODS

Human bladder cancer cell line 5637 and 2 doxorubicin drug-resistant sublines (5637/DR5.5 and 5637/DR50) were used. Measurements were made of the steady state mRNA levels of the multidrug resistance gene (mdr1), multidrug resistance-associated protein (MRP), glutathione-S-transferase-pi and DNA topoisomerase II (topo II) genes, P-glycoprotein (PgP) and MRP expression, glutathione (GSH) and GSH enzyme activity, and topo II catalytic activity. The pharmacokinetics were compared between the parent and the drug-resistant sublines.

RESULTS

5637/DR5.5 and 5637/DR50 cells were 7.6- and 16.2-fold more resistant to doxorubicin and 16.7- and 48.3-fold more resistant to etoposide, respectively, compared with 5637 cells. A dose escalation of doxorubicin increased the MRP expression, GSH levels and glutathione-S-transferase (GST) activity, although no PgP expression was observed in any cell line. Resistance was brought about by decreased drug accumulation through drug efflux, although intracellular daunorubicin concentrations were similar between DR5.5 and DR50 cells. Topo II catalytic activity was undetectable in DR50 cells, but maintained in both the parent and DR5.5 cells.

CONCLUSION

Reduced drug accumulation in doxorubicin-resistant cells was mediated by MRP instead of PgP indicating that MRP-mediated drug efflux functions in a limited manner for drug resistance. An increase in drug efflux via MRP, reduced topo II activity, and increased GSH levels/GSH-related enzyme activities may play major roles in nonPgP-mediated multidrug resistance in urothelial cancers treated with anthracyclines.

Single photon emission computed tomography-EEG relations in temporal lobe epilepsy

The role of single photon emission computed tomography (SPECT) as an independent confirmation test in presurgical evaluation of medically intractable temporal lobe epilepsy has not been critically investigated. Because spreading ictal discharges may cause a concomitant increase of cerebral blood flow in remote cerebral regions, a careful analysis of peri-injection EEG patterns and their relation to ictal SPECT may be important in evaluating the reliability of ictal SPECT. Both interictal and ictal EEG and SPECT were reviewed in 19 patients with temporal lobe epilepsy who achieved a successful seizure outcome after surgery. Patients were divided into unitemporal and bitemporal groups according to the lateralization of interictal epileptiform discharges (IED). Ictal EEG features were classified into lateralized and nonlateralized groups. The concordance between SPECT and EEG lateralizations was examined in each patient and correlated to the documented epileptogenic temporal lobe. Interictal SPECT correctly lateralized in eight of nine patients with unitemporal IED and in five of 10 patients with bitemporal IED. Ictal SPECT was highly concordant with the peri-injection ictal EEG but correctly lateralized the epileptogenic region in only 11 of 19 patients. When both pre- and postinjection EEG epochs lateralized ipsilaterally, all ictal SPECT images showed concordant lateralization. If pre- and postinjection EEG epochs were either different in lateralization or nonlateralization, ictal SPECT images often showed complex patterns of cerebral perfusion with a high incidence of false lateralization. Interictal SPECT was more sensitive and reliable in patients with unitemporal IED than in patients with bitemporal IEDs. Ictal SPECT was closely related with peri-injection EEG epochs but with frequent false lateralization. The role of ictal SPECT as an independent confirmation test in presurgical evaluation should be reappraised.

Additive Effects on the Microstructure Evolution in Hexadecyltrimethylammonium Bromide Solution and Its Rheological Properties

The effects of various additives on the microstructure evolution in hexadecyltrimethylammonium bromide micellar solution and its rheological properties are investigated. The additives considered in the present study are primary, secondary, and tertiary heptanols and sodium salicylate (NaSal). The microstructure is developed via the two-step shape transitions in the micellar solution; first, the initial spherical micelles undergo shape transition to rod-like or disc-like micelles as the micelles tend to be packed compactly with increase in the surfactant concentration; then further increment in the surfactant concentration makes the anisotropic rod-like micelles overlap each other. Solutions in these states exhibit typical non-Newtonian behaviors such as shear thinning at high shear rates. In the present study, the additive effects on the microstructure evolution are investigated by employing various techniques including a phase modulated flow birefringence, a dynamic light scattering and a dynamic oscillatory rheometry. The results show that addition of the solubilized additives enhances the microstructure transitions, which are affected by the additive concentration and its chemical structure. Presence of the cosurfactants such as heptanols with hydrophobic alkyl chains reduces the repulsion by forming surfactant-alcohol mixed micelles. The primary heptanol can penetrate easily into the micelles and aligned parallel to the surfactant molecules compared with the secondary and tertiary heptanols. Thus, the primary heptanol enhances the two-step shape evolutions more effectively than the other types. In the presence of NaSal, on the other hand, the micellar solution exhibits the viscoelastic properties and the yield stress owing to the formation of networked or worm-like micelles. Copyright 1997 Academic Press. Copyright 1997Academic Press

Apoptosis in the cornea: further characterization of Fas/Fas ligand system

This study was performed to further characterize expression and function of the Fas/Fas ligand system in the cornea. Specifically, these experiments examined (1) the effect of genetic inactivation of Fas or Fas ligand genes on keratocyte apoptosis in response to corneal epithelial wounding, (2) whether cultured human corneal epithelial and endothelial cells are competent to undergo apoptosis in response to Fas activation, (3) expression of membrane bound and soluble Fas and Fas ligand in corneal cells, and (4) the effect of IL-1 on expression of Fas and Fas ligand in corneal fibroblasts. Keratocyte apoptosis in response to corneal epithelial scrape detected by TUNEL assay and transmission electron microscopy was significantly decreased, but not eliminated, in Fas ligand -/- mice compared with control +/+ mice. There was also a decrease in Fas -/- mice that did not reach statistical significance. Thus, while the Fas/Fas ligand system is likely involved in regulating keratocyte apoptosis in response to epithelial wounding, systems with redundant function probably also modulate this response. Activation of the Fas receptor triggered death with ultrastructural changes characteristic of apoptosis in corneal epithelial and endothelial cells in culture. Since these cell types express both Fas and Fas ligand in vivo, systems must be in place to prevent uncontrolled activation via autocrine ligand-receptor interaction. Messenger RNAs coding for both membrane bound and soluble splicing variants of Fas were expressed in each corneal cell type, suggesting that soluble Fas production could be one mechanism to antagonize membrane bound Fas activation. Soluble Fas ligand protein was expressed in wounded ex vivo corneal epithelium, providing a mechanism for Fas ligand from epithelium to mediate keratocyte apoptosis. IL-1, however, also stimulated corneal fibroblasts to express Fas ligand mRNA and protein. Therefore, an alternative mode for epithelial injury to trigger keratocyte apoptosis may be by release of IL-1, subsequent induction of Fas ligand in keratocytes, and apoptosis mediated by autocrine mechanisms.

Effect of silkworm hemolymph on the expression of E. coli beta-galactosidase in insect cell lines infected with recombinant baculoviruses

The effects of silkworm hemolymph on the expression of foreign genes by recombinant baculoviruses in cell lines were studied. The expression efficiency of beta-galactosidase by recombinant virus containing the E. coli lacZ gene at various concentrations of hemolymph and FBS was determined in BmN and Sf cell lines. The addition of hemolymph to the medium containing FBS accelerated the expression of beta-galactosidase by recombinant viruses in both cells. It was more effective in BmN cells than in Sf cells. Hemolymph was most effective in enhancing virus multiplicity under conditions of 5% FBS.

Rapid purification, partial characterization, and antimicrobial spectrum of the bacteriocin, Pediocin AcM, from Pediococcus acidilactici M

The bacteriocin from Pediococcus acidilactici M, designated as Pediocin AcM, was rapidly purified to homogeneity by the pH mediated cell adsorption-desorption method and semi-preparative reversed-phase HPLC. The purification yield was 40.4% and the specific activity was increased by 2450-fold. It gave a single band and a single peak on SDS-PAGE and HPLC analysis, respectively. When subjected to electrospray LC-MS analysis, the protein was found to be highly pure and the molecular weight was determined as 4,618 Da. High concentration of the bacteriocin (> 50 micrograms/ml) showed good resistance to extremes of pH (1-12) and temperature (121 degrees C). Pediocin AcM was deduced to be a monomer with an intra-peptide disulfide bond from the results of reversed-phase analytical HPLC analyses after reduction, oxidation and trypsin digestion. P. acidilactici M inhibited a large number of bacteria, including Staphylococcus aureus, Listeria monocytogenes, Clostridium perfringens, Bacillus coagulans, B. cereus, and Aeromonas hydrophila.

Experiences of epilepsy surgery in intractable seizures with past history of CNS infection

We studied the clinical characteristics, location of epileptogenic regions, and the surgical outcomes in 18 patients with intractable epilepsy associated with previous CNS infections. All patients underwent an extensive presurgical evaluation and 11 patients had intracranial EEG monitoring. On the basis of presurgical evaluation, epileptic regions were localized to the mesial temporal (n = 12) and the neocortical (n = 6) regions. The age of the time of CNS infection was significantly younger and the latent period of non-febrile seizures after CNS infection was longer in patients with mesial temporal lobe epilepsy (MTLE). MRI showed hippocampal atrophy and hippocampal signal changes in 11 of 12 patients with MTLE. Among 6 patients with neocortical epilepsy (NE) 5 patients had normal MRI and one showed cerebral hemi-atrophy. Surgery was successful (class I & II) in all patients with MTLE, however, in the patients with neocortical epilepsy, seizure-free results were not achieved in any patients after resective surgery (6 patients) and only 2 patients achieved Class II outcomes after a second epilepsy surgery consisting of neocortical resection. Patients with MTLE after CNS infection were differentiated from the group of neocortical epilepsy by an earlier onset of CNS infection, a prolonged latent period and a higher frequency of meningitis. The characteristic pathology in this group was hippocampal sclerosis and the surgical result was excellent. Neocortical epilepsy following CNS infection usually had no focal lesion on MRI and was associated with a relatively poor surgical result. This study suggested that the surgical outcome was influenced by the type of epileptic syndromes rather than the etiology of seizures. The association of MTLE with the younger age of CNS infections and with meningitis more frequently suggested that the neocortical neurons during infancy or early childhood may be more resistant to the epileptogenesis, or that the CNS infections in patients with MTLE might be milder in severity to cause selective injuries to the hippocampal neurons during their vulnerable stage.

Adding posterior lumbar interbody fusion to pedicle screw fixation and posterolateral fusion after decompression in spondylolytic spondylolisthesis

STUDY DESIGN

This is a retrospective study analyzing 76 patients treated by decompression, pedicle screw instrumentation, and fusion for spondylolytic spondyiolisthesis with symptomatic spinal stenosis.

OBJECTIVES

To verify the advantages of adding posterior lumbar interbody fusion to the usual posterolateral fusion with pedicle screw instrumentation.

SUMMARY OF BACKGROUND DATA

Stabilization after decompression of spondylolytic spondylolisthesis is difficult because of a lack of fusional bone bases, gap between the transverse process bases, and incompetent anterior disc support. Posterior lumbar interbody fusion offers anterior support, reduction, and a broad fusion base.

METHODS

Forty patients were treated with posterolateral fusion, and 36 were treated with additional posterior lumbar interbody fusion. They were compared for union, reduction of the deformity, and clinical results.

RESULTS

The patients were followed up for more than 2 years. Nonunion was observed in three patients who underwent posterolateral fusion (7.5%), and no cases of nonunion was found in patients who underwent posterior lumbar interbody fusion. Reduction of slippage was 28.3% in those who underwent posterolateral fusion and 41.6% in those who had posterior lumbar interbody fusion (P = 0.05). In the posterolateral fusion group, eight patients (20%) had recurrence of deformity, with loss of reduction more than 50%. Hardware failures occurred in two patients who had posterolateral fusion. There was no major neurologic complications in both groups. Both groups had satisfactory results in more than 90% of patients, with marked improvement of claudication. However, subjective improvement of back pain by Kirkaldy-Willis criteria revealed differences in the excellent results. An excellent result was reported by 45% in the posterolateral fusion group and by 75% in posterior lumbar interbody fusion group.

CONCLUSIONS

The addition of posterior lumbar interbody fusion to posterolateral fusion after a complete decompression and pedicle screw fixation is a recommended procedure for the treatment of spondylolytic spondylolishesis with spinal stenosis.

Effect of optic zone size on the outcome of photorefractive keratectomy for myopia

PURPOSE

To determine the effect of optic zone size on the outcome of photorefractive keratectomy (PRK) for myopia.

SETTING

Department of Ophthalmology, Samsung Medical Center, Seoul, Korea.

METHODS

Twenty patients, 10 with myopia under 6.00 diopters (D) and 10 with myopia over 6.00 D, had bilateral PRK with identical dioptric corrections in both eyes. One eye was treated with a 5.0 mm diameter optic zone and the other with a 6.0 mm diameter optic zone. An identical postoperative eyedrop regimen was used. During the 6 month follow-up, changes in refraction, uncorrected visual acuity, and corneal anterior stromal haze were evaluated. At the end of the follow-up, patients completed a questionnaire on night-vision disturbance, foreign-body sensation, tenderness, and preference.

RESULTS

Two weeks postoperatively, eyes with a 5.0 mm optic zone had a significantly greater hyperopic shift than those with a 6.0 mm optic zone. Eyes with myopia over 6.00 D and a 6.0 mm optic zone had significantly faster recovery of uncorrected visual acuity at 2 and 12 weeks. There was no increased anterior stromal haze in the 6.0 mm optic zone eyes, despite the deeper stromal ablation. Night-vision problems were more prevalent in the 5.0 mm optic zone group, which also had a greater incidence of ablation decentration.

CONCLUSION

A 6.0 mm optic zone for myopic PRK seems to produce better outcomes. Further evaluation of long-term results is needed.

Expression of multidrug resistance-related genes (mdrl, MRP, GST-pi and DNA topoisomerase II) in urothelial cancers

OBJECTIVE

To characterize the multidrug resistance (MDR) phenotype in human urothelial cancers, the expression levels of four MDR-related genes (multidrug resistance, mdrl; multidrug resistance-associated protein, MRP; glutathione S-transferase-pi, GST-pi; and DNA topoisomerase II, topo II) were analysed in urothelial cancers.

MATERIALS AND METHODS

Fifty-two tumour tissue and three normal urothelial mucosa samples were obtained from 44 patients with urothelial cancers. The expression of each gene was analysed with a reverse-transcription polymerase chain reaction (RT-PCR) method using beta 2-microglobulin (b2m) mRNA as an endogenous control. Levels of expression were expressed as the ratio of the specific products of the target gene to those specific to b2m.

RESULTS

In primary urothelial cancer tissues, the mean (SD) expression of mdrl, MRP, GST-pi and topo II relative to b2m expression were 0.067 (0.061), 0.27 (0.23), 0.35 (0.31) and 0.12 (0.05), respectively. The mean expressions of MRP and GST-pi were higher than those of mdrl and topo II. The mean ratios of mdrl/b2m, MRP/b2m, GST-pi/b2m and topo II/b2m in normal urothelial mucosa were 0.06 (0.03), 0.12 (0.09), 0.30 (0.32) and 0.14 (0.01), respectively. There was no significant association of the expression of each gene with either the grade or extent of the primary tumour. The level of MRP expression in each sample was correlated significantly with the expression of mdrl and GST-pi in the urothelial cancers (r = 0.637 and 0.537, respectively). Chemotherapy did not markedly influence the induction of expression of the MDR-related genes, except for one case in which mdrl expression was 15 times greater than before chemotherapy. The expression of GST-pi in the patients not receiving chemotherapy was significantly higher than in those that did.

CONCLUSIONS

These results suggest that the activation of MRP and GST-pi expression occurs during the tumorigenesis of urothelial cancers and that it may confer de novo and acquired drug resistance on urothelial cancers. These results should provide further insight into the complex role postulated for MDR-related genes in chemotherapy, carcinogenesis and tumour progression.

Expression patterns of multidrug-resistance (MDR1), multidrug resistance-associated protein (MRP),glutathione-S-transferase-pi (GST-pi) and DNA topoisomerase II (Topo II) genes in renal cell carcinomas and normal kidney

PURPOSE

Expression levels of the multidrug-resistance (mdr1), multidrug resistance-associated protein (MRP), glutathione-S-transferase-pi (GST-pi) and DNA topoisomerase II (Topo II) genes in normal kidney and renal cell carcinomas were analyzed to study the complexity of the roles of these genes.

MATERIALS AND METHODS

The reverse transcription-polymerase chain reaction (RT-PCR) assay was used with beta 2 microglobulin (beta 2 m) as the internal control.

RESULTS

In normal kidneys, the expression levels of the 4 genes in individual normal kidney samples correlated significantly with one another. Comparisons of the expression levels between normal kidneys and renal cell carcinomas showed that only the mean MRP gene expression level was higher in renal cell carcinomas than in normal kidneys (p = 0.018). The expression patterns of the 4 genes in renal cell carcinomas differed markedly for nonpapillary and papillary tumors. The mean MRP/beta 2 m ratio for the papillary type was significantly lower than that for the nonpapillary alveolar type carcinoma (p = 0.004). The 4 genes showed moderate positive correlations with one another in alveolar type renal carcinoma similar to the correlations observed in normal kidneys. In contrast, in papillary type, MRP expression was inversely correlated with mdr1 and Topo II expression.

CONCLUSION

Differences in cytogenetic changes, origins and natural histories between papillary and nonpapillary carcinoma may be associated with these distinct expression patterns of the resistance-related genes. Further study is required to clarify whether the differences in the expression patterns between these 2 structural types of carcinoma affect their chemosensitivities and clinical outcomes.

Overexpression of human mutT homologue gene messenger RNA in renal-cell carcinoma: evidence of persistent oxidative stress in cancer

Data regarding oxidatively modified DNA bases suggest that cancer cells are more exposed to oxidative stress than adjacent non-tumorous tissue. This novel concept may contribute to the understanding of certain aspects of tumor biology such as activated transcription factors, genetic instability, chemotherapy-resistance and metastasis. We therefore tested this concept in human renal-cell carcinomas (RCCs) by evaluating the expression of hMTH1, an enzyme preventing the misincorporation into DNA of 8-oxo-dGTP (8-oxo-7,8-dihydrodeoxyguanosine triphosphate), an oxidized form of dGTP in the nucleotide pool. The expression of hMTH1 messenger RNA (mRNA) in RCC was significantly higher than that in adjacent non-tumorous kidney. Moreover, advanced-stage tumors showed significantly higher hMTH1 mRNA expression than early-stage tumors, and there was a modest linear correlation between hMTH1 expression and c-myc expression. The results provide logical support for the concept of "persistent oxidative stress in cancer" and suggest a role of hMTH1 mRNA level as a prognostic marker.

Overexpression of human mutT homologue gene messenger RNA in renal-cell carcinoma: evidence of persistent oxidative stress in cancer

Data regarding oxidatively modified DNA bases suggest that cancer cells are more exposed to oxidative stress than adjacent non-tumorous tissue. This novel concept may contribute to the understanding of certain aspects of tumor biology such as activated transcription factors, genetic instability, chemotherapy-resistance and metastasis. We therefore tested this concept in human renal-cell carcinomas (RCCs) by evaluating the expression of hMTH1, an enzyme preventing the misincorporation into DNA of 8-oxo-dGTP (8-oxo-7,8-dihydrodeoxyguanosine triphosphate), an oxidized form of dGTP in the nucleotide pool. The expression of hMTH1 messenger RNA (mRNA) in RCC was significantly higher than that in adjacent non-tumorous kidney. Moreover, advanced-stage tumors showed significantly higher hMTH1 mRNA expression than early-stage tumors, and there was a modest linear correlation between hMTH1 expression and c-myc expression. The results provide logical support for the concept of "persistent oxidative stress in cancer" and suggest a role of hMTH1 mRNA level as a prognostic marker.

Holmium:YAG Laser Thermokeratoplasty for Astigmatism in Rabbits

BACKGROUND

Holmium:YAG laser thermokeratoplasty has generated considerable interest as a technique for correcting hyperopia. In this study, the effect of holmium:YAG laser on inducing astigmatism according to application patterns was evaluated.

METHODS

An experimental study based on the results of astigmatic holmium:YAG laser thermokeratoplasty using the Summit OmniMed laser system (Summit Technology Inc, Waltham, Mass) in 36 rabbit eyes is presented. We divided the rabbits into four groups: arcuate, reverse arcuate, linear, and control group according to application patterns. All rabbits were followed for 3 months and cycloplegic refractive measurements were carried out.

RESULTS

The average surgically induced astigmatism was 1.86 diopters (D) for the arcuate group, 2.93 D for the reverse arcuate group, and 1.31 D for the linear group. No significant complications related to the operation were noted.

CONCLUSION

The reverse arcuate pattern of holmium:YAG laser thermokeratoplasty is most effective in inducing astigmatism in rabbits.

A clinical study of chronic headaches: clinical characteristics and depressive trends in migraine & tension-type headaches

BACKGROUND & OBJECTIVES

Chronic headache is commonly encountered in the neurology outpatient clinic and it is often associated with depression. In Korea, however, chronic headache has not yet been systematically investigated. We conducted this study to investigate this clinical characteristics and level of depression in patients who presented migraine, tension-type headache, or transformed migraine.

METHOD

Among those with chronic headache during the period from January 1, 1994 through December 31, 1994, 131 patients were diagnosed to have either migraine, tension-type headache (by IHS classification), or transformed migraine: migraine in 60 patients, tension-type headache in 49 patients, and transformed migraine in 22 patients. Beck Depression Inventory (BDI) was performed in 116 of the 131 patients.

RESULTS & CONCLUSION

There was no significant difference in the age of onset, duration of headache, and family history among the three groups. However, patients with migraine had a more severe, unilateral, and throbbing characteristic pain than those with a tension-type headache. The mean BDI scores in the transformed migraine and the tension-type headache patients were significantly higher than those of migraine, but the level of depression did not correlate with the patient's age, duration, character, severity, and frequency of headache. These findings suggest that migraine, tension-type headache and transformed migraine may be considered clinically distinct entities in viewing their different clinical characteristics and level of depression.