Stage-dependent regulation of ovarian pituitary adenylate cyclase-activating polypeptide mRNA levels by GnRH in cultured rat granulosa cells

The present study was designed to test whether GnRH regulates pituitary adenylate cyclase-activating polypeptide mRNA levels in a stage-dependent manner during follicle development in the rat ovary. The granulosa cells of preovulatory and immature follicles obtained from PMSG- and estrogen-treated rats, respectively, were cultured in serum-free conditions in the presence of various hormones. GnRH receptor mRNA expression was detected in both preovulatory and immature granulosa cells and was down-regulated by gonadotropins. Treatment of preovulatory granulosa cells with GnRH agonist stimulated pituitary adenylate cyclase-activating polypeptide mRNA levels in a dose-dependent manner. In situ hybridization analysis of cultured preovulatory follicles revealed that GnRH-induced pituitary adenylate cyclase- activating polypeptide signals were detected in granulosa cells, but not thecal cells. In immature granulosa cells, cotreatment with GnRH agonist suppressed FSH-stimulated pituitary adenylate cyclase-activating polypeptide mRNA levels in a dose-dependent manner, whereas treatment with GnRH alone had no effect. Furthermore, treatment with GnRH antagonist inhibited LH-induced pituitary adenylate cyclase-activating polypeptide gene expression in preovulatory granulosa cells, whereas it stimulated FSH-induced pituitary adenylate cyclase-activating polypeptide gene expression in immature granulosa cells. Interestingly, GnRH-stimulated pituitary adenylate cyclase-activating polypeptide mRNA levels in preovulatory granulosa cells was inhibited by arachidonyltri fluoromethyl ketone, an inhibitor of phospholipase A(2), but not by an inhibitor of protein kinase A or C. Lastly, treatment of preovulatory follicles with pituitary adenylate cyclase-activating polypeptide antagonist suppressed GnRH-stimulated progesterone production during 6--9 h of culture. Taken together, these results demonstrate the stage-dependent regulation of pituitary adenylate cyclase-activating polypeptide mRNA levels by GnRH, the stimulatory and inhibitory effect in granulosa cells of preovulatory and immature follicles, respectively.

Helicobacter pylori infection in Korea

Helicobacter pylori is a gram-negative bacterium that was first isolated in 1982. Since then, H. pylori infection in humans has been shown to be associated with gastritis, peptic ulcer disease, gastric carcinoma, and mucosa-associated lymphoid tissue (MALT) lymphoma as well. The epidemiology, transmission, and pathogenicity of H. pylori has been a subject of intensive study. Successful treatment improves the cure rate of peptic ulcerations and treatment with antimicrobials also decreases the recurrence rate of these diseases. Better regimens having less toxicity and a good eradication rate have also been developed. A better understanding of the pathophysiologic mechanisms relating to H. pylori induced mucosal damages would result in more options for the prevention of peptic ulcers and carcinogenesis. Korea has a relatively high incidence of H. pylori infection and gastric cancer. Growing interest has developed in view of its importance in being associated with various gastroduodenal diseases. Furthermore, along with a high incidence of H. pylori-related disease in Korea, because the interaction between H. pylori, host factors and environmental factors is important in disease pathogenesis, we need to have precise data on the characteristics of H. pylori-related diseases that occur in Korea. In the present report we review the epidemiology, transmission route, diagnosis, pathogenesis, treatment methods and relationship with gastroduodenal diseases with in special references to basic and clinical data that have been published.

Peroxynitrite scavenging and cytoprotective activity of 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether from the marine alga Symphyocladia latiuscula

Peroxynitrite (ONOO(-)), formed from the reaction of superoxide (O(2)*(-)) and nitric oxide (*NO), is a cytotoxic species that can oxidize several cellular components such as proteins, lipids, and DNA. It has been implicated in diseases such as Alzheimer's disease, rheumatoid arthritis, cancer, and atherosclerosis. Due to the lack of endogenous enzymes responsible for ONOO(-) inactivation, developing a specific ONOO(-) scavenger is of considerable importance. The aim of this study was to evaluate the ability of marine natural products to scavenge ONOO(-) and to protect cells against ONOO(-). Methanolic extracts of 17 marine alga were tested for their ONOO(-) scavenging activity. Among them, Symphyocladia latiuscula showed the potent scavenging activity. CH(2)CH(2) fraction was partitioned with CH(2)CH(2) following n-hexanal extraction from the methanol extract of S. latiuscula. It was highly effective for ONOO(-) scavenging activity. Further analysis of the active fractionated extract identified 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (TDB) as a potent ONOO(-) scavenger. The data demonstrated that TDB led to decreased ONOO(-)-mediated nitration of tyrosine through electron donation. TDB showed significant inhibition on nitration of bovine serum albumin and low-density lipoprotein by ONOO(-) in a dose-dependent manner. It also provided cytoprotection from cell damage induced by ONOO(-). TDB can be developed as an effective peroxynitrite scavenger for the prevention of the involved diseases.

Apoptosis-Inducing costunolide and a novel acyclic monoterpene from the stem bark of Magnolia sieboldii

In a course of obtaining more amount of bioactive costunolide and successive phytochemical isolation from Magnolia sieboldii (Magnoliaceae), a novel acyclic monoterpene 1 named deoxygeraniol [2,6(E)-dimethyl-2,6-octadiene] was isolated along with beta-sitosterol 3-O-linoleate (2), trilinolein (3) and high amount of costunolide (4) in the pure state. The structure of compound 1 was determined on the basis of spectroscopic data. Costunolide was found to induce apoptotic cell death in a dose-dependent manner by nucleosomal DNA ladder and flow cytometric analysis. Immunoblot analysis showed that the level of the anti-apoptotic protein, Bcl-2, was decreased, whereas the cleavage of poly-(ADP-ribose) polymerase was activated. Furthermore, the N-acetyl-L-cysteine antioxidant effectively prevented costunolide-induced cytotoxicity. These results suggest that costunolide-induced cell death is mediated by reactive oxygen species

Expression of exo-polygalacturonases in Botrytis cinerea

The pathogenic fungus, Botrytis cinerea, causing gray mold disease in a variety of plant species, secretes at least four polygalacturonases (PGs), cell wall degrading enzymes. Among them, we prepared polyclonal antibody against purified 66-kDa exo-PG in rabbit. Immunoblot analysis revealed that the antibody recognized two exo-PGs, 66 kDa and 70 kDa in molecular mass, secreted from B. cinerea cultured in the medium containing citrus pectin as a carbon source. By immunohistochemical analysis, the expression of exo-PGs was identified in cucumber leaves inoculated with spores of B. cinerea. The exo-PGs were observed 9 h after inoculation, and the amount of exo-PGs increased with time in the leaves. The exo-PGs were induced by polygalacturonic acid as well as its monomer, galacturonic acid, in vitro. The expression of 66-kDa exo-PG (exo-PG I) increased with time of culture, while 70-kDa exo-PG (exo-PG II) was transiently expressed soon after the start of culture. Therefore, exo-PGs might play an important role in pathogenesis at an early stage of infection as well as in tissue maceration of host plant.

BetaPix-enhanced p38 activation by Cdc42/Rac/PAK/MKK3/6-mediated pathway. Implication in the regulation of membrane ruffling

betaPix (PAK-interacting exchange factor) is a recently identified guanine nucleotide exchange factor for Rho family small G protein Cdc42/Rac. The protein interacts with p21-activated protein kinase (PAK) through its SH3 domain. We examined the effect of betaPix on MAP kinase signaling and cytoskeletal rearrangement in NIH3T3 fibroblast cells. Overexpression of betaPix enhanced the activation of p38 in the absence of other stimuli and also induced translocation of p38 to the nucleus. This betaPix-induced p38 activation was blocked by coexpression of dominant-negative Cdc42/Rac or kinase-inactive PAK, indicating that the effect of betaPix on p38 is exerted through the Cdc42/Rac-PAK pathway and requires PAK kinase activity. The essential role of betaPix in growth factor-stimulated p38 activation was evidenced by the blocking of platelet-derived growth factor-induced p38 activation in the cells expressing betaPix SH3m (W43K) and betaPix DHm (L238R,L239R). In addition, SB203580, a p38 inhibitor, and kinase-inactive p38 (T180A,Y182F) blocked membrane ruffling induced by betaPix, suggesting that p38 might be involved in mediating betaPix-induced membrane ruffling. The results in this study suggest that betaPix might have a role in nuclear signaling, as well as in actin cytoskeleton regulation, and that some part of these cellular functions is possibly mediated by p38 MAP kinase.

Risk factors for recurrence of primary bile duct stones after endoscopic biliary sphincterotomy

BACKGROUND

Endoscopic biliary sphincterotomy (EST) is a well-established procedure for bile duct stone extraction. Bile duct stones can be classified as primary or secondary. However, few data are available on the recurrence of primary and secondary bile duct stones after EST. Therefore risk factors for the recurrence of primary bile duct stones after EST were prospectively studied.

METHODS

Between 1991 and 1997, 61 patients underwent EST for primary bile duct stones. All met the following criteria: (1) previous cholecystectomy without bile duct exploration, (2) detection of bile duct stones at least 2 years after initial cholecystectomy. Mean follow-up was 2.2 years. Fourteen patients were lost to follow-up. The recurrence of primary bile duct stones was defined as the detection of bile duct stones no sooner than 6 months after complete clearance of primary bile duct stones.

RESULTS

The overall recurrence rate of primary bile duct stones was 21% (10 of 47). Two significant risk factors for recurrence were identified by multivariate analysis: (1) patients with a bile duct diameter of 13 mm or greater after stone removal had recurrences more frequently than those with a duct diameter of 13 mm or less, and (2) patients whose papilla was located on the inner rim or deep within a diverticulum, so that the papillary orifice was not visible endoscopically, had more frequent recurrences than patients with a papilla outside the diverticulum, or no peripapillary diverticulum.

CONCLUSION

The independent risk factors for recurrence of primary bile duct stones were sustained dilation of the bile duct even after complete removal of stones and location of the papilla on the inner rim or deep within a diverticulum.

Gonadotropin regulation of NGFI-B messenger ribonucleic acid expression during ovarian follicle development in the rat

NGFI-B is an immediate-early gene that encodes an orphan nuclear receptor. The present study was designed to examine the localization and gonadotropin regulation of NGFI-B expression in the rat ovary. Northern blot analysis of ovaries obtained from prepubertal rats revealed the increased expression of NGFI-B during prepubertal development. Treatment of immature rats with PMSG, however, decreased ovarian NGFI-B expression. The major cell types expressing NGFI-B messenger RNA were thecal cells of follicles in different sizes. In contrast, treatment of PMSG-primed rats with human (h) CG resulted in the rapid and transient stimulation of ovarian NGFI-B messenger RNA, reaching a peak within 1 h. In situ hybridization analysis revealed that hCG treatment induced the expression of NGFI-B in granulosa cells of preovulatory follicles. Treatment of cultured preovulatory follicles in vitro with LH further confirmed the time- and dose-dependent stimulation of NGFI-B messenger RNA and protein. LH-stimulated NGFI-B expression in preovulatory follicles was abolished by alpha-amanitin, but was superinduced by cycloheximide. Furthermore, treatment of adult cycling rats with pentobarbital abolished NGFI-B expression on proestrus, and exogenous administration of hCG restored it, indicating the role of the preovulatory surge of LH in the stimulation of NGFI-B expression. These results demonstrate the cell type-specific expression and gonadotropin induction of NGFI-B in granulosa cells of preovulatory follicles and suggest a role for NGFI-B in the ovulatory process.

Finger reconstruction with a free neurovascular wrap-around flap from the big toe

From 1983 to 1998, 16 cases of finger reconstruction with a free neurovascular wrap-around flap from the big toe were treated. Fourteen cases were successful, and two cases failed. The authors reviewed these cases on the average of about 38 months after surgery. Pinch power was 51 percent of the unaffected normal hand, and two-point discrimination was 7.6 mm. The mean resorption of the grafted bone was 13 percent in width and 9 percent in length. There were no complications such as fracture of the grafted bone, nonunion, and pulp dislodgement. This procedure provided length, stability, and adequate sensibility for a functional pinch and grasp. Sensory return to the wrap-around flap on the thumb was often greater than for the same area on the opposite foot. The donor site of the wrap-around flap was acceptable, both aesthetically and functionally, and allowed the wearing of open-toed shoes by young women. Finger reconstruction with a wrap-around flap from the big toe yielded excellent cosmetic and functional results in cases involving amputation at the level of the metacarpophalangealjoints or distal to it. In addition, this procedure was an excellent choice for treatment in cases involving avulsion injuries of the fingers and reconstruction of soft-tissue defects after tumor excision.

Ecthyma gangrenosum without bacteraemia in a leukaemic patient

Ecthyma gangrenosum is a well recognized cutaneous manifestation of Pseudomonas aeruginosa infections in immunocompromised patients. Most cases of ecthyma gangrenosum have been associated with concomitant septicaemia. However, ecthyma gangrenosum rarely develops due to Ps. aeruginosa in the absence of bacteraemia. We report a rare case of a nonsepticaemic form of ecthyma gangrenosum presenting as a large solitary necrotic ulcer in a patient with acute myelogenous leukaemia. A culture from the lesion revealed the presence of Ps. aeruginosa, but the results of repeated blood cultures were negative. Histological examination revealed numerous tiny eosinophilic bacilli in the dermis and panniculus with Gram's stain.

Extraovarian granulosa cell tumor

A 54-year-old woman was admitted to our hospital complaining of postcoital bleeding. Sonography of the abdomen showed a 8.2 x 8.9 cm-sized solid heterogeneous mass occupying the cul-de-sac, which appeared to be in no way connected with the ovary. On exploratory laparotomy, the tumor mass protruded from the posterolateral retroperitoneum of the pelvic cavity and severely replaced the uterus and adnexa with the outer surface being grossly intact. It grossly measured 10 cm in maximal diameter. The histologic features closely resembled those of ovarian granulosa cell tumor. The primary extraovarian granulosa cell tumor is extremely rare such that in the English literature only 7 cases have been reported to date. Of those granulosa cell tumors are especially rare and only two cases have been reported to arise from retroperitoneum. We herein present a case of retroperitoneal granulosa cell tumor with special regard to differential diagnosis from other solid tumors with similar histology.

Induction of plant gp91 phox homolog by fungal cell wall, arachidonic acid, and salicylic acid in potato

The oxidative burst has been suggested to be a primary event responsible for triggering the cascade of defense responses in various plant species against infection with avirulent pathogens or pathogen-derived elicitors. The molecular mechanisms of rapid production of active oxygen species (AOS), however, are not well known. We isolated homologs of gp91 phox, a plasma membrane protein of the neutrophil NADPH oxidase, from a potato cDNA library. Molecular cloning of the cDNA showed that there are two isogenes, designated StrbohA and StrbohB, respectively. The RNA gel blot analyses showed that StrbohA was constitutively expressed at a low level, whereas StrbohB was induced by hyphal wall components (HWC elicitor) from Phytophthora infestans in potato tubers. Treatment of potato tubers with HWC elicitor caused a rapid but weak transient accumulation of H2O2 (phase I), followed by a massive oxidative burst 6 to 9 h after treatment (phase II). Diphenylene iodonium (DPI), an inhibitor of the neutrophil NADPH oxidase, blocked both bursts, whereas pretreatment of the protein synthesis inhibitor cycloheximide with the tuber abolished only the second burst. These results suggest that the expression of StrbohA and StrbohB contributes to phase I and II bursts, respectively. The same is true for arachidonic acid, a lipid component of P. infestans-stimulated biphasic oxidative burst, whereas an endogenous signaling molecule, salicylic acid, only induced a weak phase II burst. Both molecules induced the StrbohB expression, which is in agreement with the second burst. To characterize the signal transduction pathway leading to the oxidative burst, we examined the role of protein phosphorylation in HWC-stimulated StrbohB gene expression. K252a and staurosporine, two protein kinase inhibitors, blocked the transcript accumulation. Two inhibitors of extracellular Ca2+ movement, however, did not abolish the transcript accumulation of StrbohB, suggesting that certain calcium-independent protein kinases are involved in the process of StrbohB gene expression. Additionally, we examined a causal relationship between the oxidative burst and expression of defense genes induced by the HWC elicitor. The transcript accumulation of genes related to sesquiterpenoid phytoalexin synthesis (lubimin and rishitin) and phenylpropanoid pathway was inhibited slightly by the DPI treatment, suggesting that the oxidative burst is not essential to activate these genes. Interestingly, the concomitant presence of DPI with the elicitor resulted in an increase in lubimin accumulation and a decrease in rishitin accumulation. Because it is known that lubimin is metabolized into rishitin via oxylubimin, we propose that AOS mediates the synthesis of rishitin from lubimin.

Arterial switch operation: factors impacting survival in the current era

BACKGROUND

The arterial switch procedure has become the preferred procedure for the transposition of the great arteries (TGA) and Taussig-Bing anomaly. This analysis is intended to identify potential factors affecting survival in the current era.

METHODS

From 1986 to 1999, 201 consecutive patients underwent an arterial switch operation for TGA or Taussig-Bing anomaly. Multivariate analysis of perioperative variables was performed for operative morbidity/ mortality. Patients were separated into two groups. Phase 1 (n = 29) included patients before mid-1989 who underwent an open coronary reimplantation technique. Phase 2 (n = 172) included the patients undergoing a technique of reimplanting coronary buttons after neoaortic reconstruction.

RESULTS

The patient population included TGA with intact ventricular septum (58.7%, 118 of 201), with ventricular septal defect (31.3%, 61 of 201), and Taussig-Bing anomaly (10.0%, 22 of 201). Overall, early mortality was 9.5% (19 of 201) and there were five late deaths (2.7%). One-month, 1-year, and 5-year actuarial survival rates were 90.4%, 87.9%, and 87.9%, respectively. Reoperation rate for late pulmonary stenosis was 2.7% (5 of 182). The freedom from reoperation at 3 and 5 years was 97.5% and 93.3%, respectively. In the analysis by time period, the operative mortality declined from 27.6% (8 of 29) to 6.4% (11 of 172) (p = 0.002). Risk factors for operative death were coronary artery patterns (usual vs retropulmonary left coronary artery, p = 0.009) in phase 1 and preoperative instability in phase 2 (p = 0.002).

CONCLUSIONS

The arterial switch operation for TGA and Taussig-Bing anomaly has early low and late mortality and reoperation rates. Technical modifications in coronary reimplantation have minimized coronary artery pattern-related risks.

Toxicology of Kalopanax pictus extract and hematological effect of the isolated anti-rheumatoidal kalopanaxsaponin A on the Freunds complete adjuvant reagent-treated rat

We have reported that kalopanaxsaponin A (KPS-A) isolated from Kalopanax pictus have anti-rheumatoidal activity in the rat treated with Freunds complete adjuvant (FCA) reagent. In addition, it has been also reported that KPS-A is a potent antioxidant in the rheumatoidal rat. This research was undertaken to examine whether the saponins of KPS-A and -I could adjust the abnormal lipid metabolisms and hematological changes in immunological diseases. KPS-A significantly inhibited the increases in both triglycerides and total proteins in addition to the decrease in total cholesterol induced by FCA reagent treatment. KPS-A treatment decreased the number of leucocytes elevated by FCA reagent treatment. Excess dose of the methanol extract produced no severe toxicity on the body weight, wet organ weights and hepatic functions. Since LD50 value of K. pictus methanol extract was shown to be 4,033 mg/kg, it could be estimated to be a safe agent for anti-rheumatoidal herbal medicines.

Acidic environment modifies heat- or radiation-induced apoptosis in human maxillary cancer cells

PURPOSE

The effects of hyperthermia or irradiation on cell killing and induction of apoptosis were evaluated using human maxillary carcinoma IMC-3 cells and low pH (pH 6.8) adapted cells (IMC-3-pH).

METHODS AND MATERIALS

Cellular heat-sensitivity or radiosensitivity was determined using the clonogenic assay. Apoptosis was assessed on the basis of a flow cytometric determination of the DNA content, DNA fragmentation, and poly(ADP-ribose)polymerase cleavage.

RESULTS

When IMC-3 cells or IMC-3-pH cells were exposed to heat at 44 degrees C in pH 6.8 medium, an increase in thermosensitivity was observed compared with when the IMC-3 cells were exposed to heat at 44 degrees C in pH 7.4 medium. However, the selective reduction in survival was not observed after irradiation. In IMC-3 cells, apoptosis after heating at 44 degrees C for 60 min in pH 7.4 medium occurred earlier than that after 8 Gy irradiation, although both thermal and irradiated doses decreased the cell count to 10%. The degree of apoptosis after heating at pH 6.8 in IMC-3 cells or IMC-3-pH cells was greater than that at pH 7.4 in IMC-3 cells. However, the degree of apoptosis after 8 Gy irradiation at pH 6.8 in IMC-3 cells or IMC-3-pH cells was smaller than that at pH 7.4 in IMC-3 cells.

CONCLUSION

Hyperthermia treatment is more effective at inducing apoptosis than radiation is in tumors that contain a population of low pH adapted cells.

Immunohistochemical study on proliferative activity of experimental cholesteatoma

In this study, we induced canal ligation cholesteatoma using Mongolian gerbils and investigated the hyperproliferative nature of canal ligation cholesteatoma by using an immunohistochemical technique with proliferation markers (cytokeratin 13/16, PCNA, EGFR, thrombomodulin). Canal ligation cholesteatoma using Mongolian gerbils had a hyperproliferative character in the suprabasal cell layer similar to human cholesteatomas. This result will provide a good morphological basis for future cholesteatoma animal research concerning the pathogenesis of cholesteatoma.

Growth inhibition and chemosensitivity of poorly differentiated human thyroid cancer cell line (NPA) transfected with p53 gene

BACKGROUND

We investigated whether retroviral p53 transfection could enhance growth inhibition and chemosensitivity in a p53 mutant papillary thyroid cancer cell line (NPA).

METHODS

NPA cells were transfected with either LXSN/p53 or mock infection in the presence of Adriamycin. Gene expression was confirmed by western blotting. Nude mice were injected subcutaneously with NPA cells after transfection with either LXSN/p53 or mock infection on opposite sides, and the tumor growth was compared.

RESULTS

There was a dose-dependent inhibition of tumor growth with LXSN/p53 transfection. Tumor growth was inhibited more by p53 gene transfection relative to mock transfection in the presence of Adriamycin.

CONCLUSION

These treatment modalities could be beneficial in the treatment of p53 mutant positive thyroid cancers.

Percutaneous transhepatic cholangioscopic treatment for hepatolithiasis: an evaluation of long-term results and risk factors for recurrence

BACKGROUND

Percutaneous transhepatic cholangioscopy (PTCS) has a major role in the treatment of hepatolithiasis. The aims of this study were to evaluate immediate and long-term results of PTCS treatment and to elucidate the risk factors for recurrence of stones or cholangitis.

METHODS

A retrospective study was conducted of patients with hepatolithiasis who underwent PTCS treatment. A total of 92 patients underwent PTCS treatment and 68 were followed for 24 to 60 months (median 42 months).

RESULTS

Complete clearance of stones was achieved in 74 (80%) patients. The rate of complete clearance was significantly lower in patients with severe intrahepatic strictures compared with that for those with no strictures (14 of 24, 58% vs. 16 of 16, 100%, p < 0.01) and those with mild to moderate strictures (14 of 24, 58% vs. 44 of 52, 85%, p < 0.05). Patients with severe intrahepatic strictures had a higher recurrence rate than those with no or mild strictures (100% vs. 28%, p < 0.01). In addition the recurrence rate in patients with advanced biliary cirrhosis (Child's class B or C) was higher than in those with no or mild (Child's class A) cirrhosis (89% vs. 29%, p < 0.01). In patients with type I and II hepatolithiasis (Tsunoda classification), stones recurred in 2 (12%) patients at 28 and 32 months after successful stone removal, without further recurrence afterwards. The recurrence rate in patients with type III and IV hepatolithiasis increased gradually up to 50% at 60 months of follow-up.

CONCLUSIONS

Severe intrahepatic stricture was the only factor that affected the immediate success rate of PTCS in the treatment of hepatolithiasis. Several risk factors including severe biliary stricture, advanced biliary cirrhosis and Tsunoda type III and IV affected the long-term results.

L-Arginine regulates the expression of the T-cell receptor zeta chain (CD3zeta) in Jurkat cells

L-Arginine is a versatile amino acid that plays a central role in the normal function of several organ systems including the immune system. Its availability is tightly controlled and varies significantly in different organs and tissues in the body. L-Arginine plays an important role in supporting T-cell proliferation. Its depletion in certain disease states results in a diminished T-cell response. The main purpose of this study was to determine the effect of the depletion of L-arginine on the expression of the T-cell receptor (TCR) proteins. When the helper T-cell line Jurkat was cultured in arginine-free medium, there was a preferential decrease in the expression of the TCR zeta chain (CD3zeta). The reduced expression of CD3zeta was observed within 24 h of culture in L-arginine-free medium and was completely reversed with the replenishment of L-arginine. Furthermore, the absence of L-arginine blocked the normal re-expression of the TCR that had been internalized after antigen stimulation. There also was a significant decrease in proliferation of Jurkat cells in the absence of L-arginine; however, L-arginine depletion did not prevent the up-regulation of the interleukin 2 receptor chains upon stimulation, nor did it significantly diminish the production of interleukin 2. The changes in the expression of CD3zeta chain were not induced by apoptosis. Thus, the availability of L-arginine in the microenvironment may play a significant role in regulating the expression of the TCR.

Kalopanaxsaponin A is a basic saponin structure for the anti-tumor activity of hederagenin monodesmosides

Hederagenin, delta-hederin [hederagenin alpha-L-arabinoside], kalopanax-saponin A [hederagenin 3-O-alpha-L-rhamnosyl(1-->2)-alpha-L- arabinoside], kalopanaxsaponin I [hederagenin 3-O-beta-D-xylosyl(1-->3)-alpha-L- rhamnosyl(1-->2)-alpha-L-arabinoside], and sapindoside C [hederagenin 3-O-beta-D-glucosyl(1-->4)-beta-D-xylsyl (1-->3)-alpha-L-rhamnosyl(1-->2)-alpha-L-arabinoside] were isolated from stem bark of Kalopanax pictus Nakai (Araliaceae). Among glycosides of hederagenin, disaccharide (kalopanaxsaponin A, commonly also called alpha-hederin), trisaccharide (kalopanaxsaponin I), and tetrasaccharide (sapindoside C) showed significant cytotoxicity on several types of tumor cells, while hederagenin itself exhibited only weak cytotoxicity and its monosaccharide (delta-hederin) was non-cytotoxic. From these results, it suggests that the arabinosyl moiety at C-3 blocks the activity of hederagenin and the position of the second sugar for glycoside linkage is also important for cytotoxicity. In the in vivo experiments, kalopanaxsaponin A (15 mg/kg, i.p.) apparently increased the life span of mice bearing Colon 26 and 3LL Lewis lung carcinoma, as well as cisplatin (3 mg/kg, i.p.). These results indicated that kalopanaxsaponin A has potential anti-tumor applications.

Interleukin-4 induces two distinct GAS-binding complexes containing STAT6: evidence for DNA binding of STAT6 monomer

Treatment of tonsillar mononuclear cells with interleukin-4 (IL-4) rapidly induced the formation of two distinct complexes upon reaction of the cell extracts with the IL-4-responsive element (IL-4RE) of the CD23b promoter in the electrophoretic mobility sift assays (EMSA). The two complexes were detected with a similar activation kinetics upon IL-4 stimulation. They were both immunoreactive with antibodies to signal transducer and activator of transcription (STAT) 6. The upper complex, however, appeared more stable in the competitor oligomer binding assays and more resistant in the anti-phosphotyrosine antibody inhibition assays than the lower complex. Western blot analysis revealed a single peptide of 105 kDa reacting with anti-STAT6 antibodies, which ruled out the possibility for multiple isoforms of STAT6 in these cells. Subsequently, Southwestern analysis demonstrated that monomeric STAT6 in the IL-4-treated nuclear extract can bind the labeled IL-4RE in an activation-dependent manner. Our data strongly suggests that in addition to dimeric STAT6, monomeric STAT6, albeit with a lower affinity, can bind the IL-4RE/gamma activation site (GAS) upon IL-4-induced activation. Also, the upper and lower bands observed in EMSA are likely to represent dimeric and monomeric STAT6 bound to the IL-4RE oligomer, respectively. The functional implication of the STAT6 monomer binding to GAS in the IL-4-induced gene activation is discussed.

Two cases of Kimura's disease with unusual clinical manifestations

We report 2 cases of Kimura's disease with unusual clinical presentation. Lesions were itching nodules located at the elbow and the dorsum of the hand, and were associated with unusual laboratory values. These features may lead to problems in clinical differential diagnosis.

Effects of red ginseng upon vascular endothelial function in patients with essential hypertension

This study is to estimate the effect of Korean red ginseng on vascular endothelial cell dysfunction in patients with hypertension. Seventeen patients with hypertension who were divided into ginseng-treated (7) and non-treated (10) groups and 10 normotensive subjects were included. To assess the function of the vascular endothelial cell, changes of forearm blood flow to infusion of acetylcholine, sodium nitroprusside and bradykinin in incremental doses were measured by venous occlusion plethysmography. In the ginseng-treated hypertensive group, forearm blood flows at the highest dose of acetylcholine and bradykinin were significantly higher than those of the non-treated hypertensive group and were not different from those of the control group. In the case of sodium nitroprusside infusion, no significant differences were observed between the control, non-treated and treated groups. In conclusion, Korean red ginseng can improve the vascular endothelial dysfunction in patients with hypertension possibly through increasing synthesis of nitric oxide.

Lower gastrointestinal bleeding due to cytomegalovirus ileal ulcers in an immunocompetent man

Cytomegalovirus (CMV) infections are commonly reported in severely immunocompromised hosts and ulcers of the alimentary tract are frequently observed in systemic CMV infections. However, invasive and ulcerative disease of the gastrointestinal (GI) tract caused by CMV has also been reported in healthy adults. Many reports show that a CMV infection can produce localized ulcerations in the esophagus, stomach, small intestine, and colon in nonimmunocompromised individuals. The most common site of involvement by CMV infection in the GI tract is the colon followed by the upper GI tract and the least common site is the small intestine. Although GI bleeding is one of the major presenting symptoms of patients with CMV infections of the GI tract, lower GI bleeding due to CMV ileal ulcers in immunocompetent patients, to our knowledge, has not been reported in the English literature. Recently, we experienced a case of lower GI bleeding due to CMV ileal ulcers in a 57-year-old man who had no evidence of immunocompromise. This case suggests that small intestinal ulcers due to CMV infection should be included in the differential diagnosis of lower GI bleeding even in immunocompetent hosts.

Reduction in intraocular pressure after laser in situ keratomileusis

PURPOSE

To investigate whether intraocular pressure (IOP) measured on the nasal side is affected after laser in situ keratomileusis (LASIK).

SETTING

The Glaucoma Service, Dr. Hong's Eye Clinic, Seoul, Korea.

METHODS

In 83 patients, IOP was prospectively measured with the Goldmann tonometer at the central (Tcenter) and nasal (Tnasal) areas of the cornea before and after LASIK. The Tcenter and Tnasal IOP between baseline and 1, 3, and 6 months postoperatively was compared. The correlation between ablation depth, amount of treatment, refractive change, and change in central corneal thickness and Tcenter change was evaluated.

RESULTS

Six months after LASIK, Tcenter IOP decreased 3.9 mm Hg (25.2%) and Tnasal IOP decreased 2.0 mm Hg (12.7%) (P < .001, P = .02, respectively). The Tnasal measurement was 1.8 mm Hg higher than the Tcenter measurement (P < .001). Significant correlation between each corneal parameter and the Tcenter reduction at 1 month did not continue to 6 months (P > .05).

CONCLUSION

At each follow-up, Tnasal IOP was statistically lower than at baseline, although the reduction was not as great as that of Tcenter IOP. A 2 to 3 mm Hg drop in Tnasal up to 6 months after LASIK should be expected. An alternative would be to measure IOP with the Tono-Pen on the nasal side to fit the tip to the relatively unchanged nasal side of the cornea.

Primary unreamed intramedullary nailing for open fractures of the tibia

Forty-six open tibial fractures (42 patients) were treated by primary unreamed intramedullary nailing, with debridement of open wounds and treatment of soft tissue. According to Gustilo-Anderson classification there were 18 grade I cases, 18 grade II cases and 10 grade III cases. The incidence of infection was low with two cases of superficial infection and one of deep infection. The mean time for union was 21.9 weeks and the rate of nonunion was 10.8%. There was no significant difference in the mean time to union, infection rate and rate of nonunion with different site and grade of fracture, but there was a longer union time and a higher rate of nonunion in complex and comminuted fractures. Unreamed intramedullary nailing, with appropriate soft tissue treatment, gives good results in the treatment of open tibial fractures including grade III.

Oxidative stress effect on the activation of hepatic stellate cells

Collagen is the most excessive extracellular matrix protein in hepatic fibrosis. Activated, but not quiescent, hepatic stellate cells (HSCs) have a high level of collagen and a smooth muscle actin (alpha SMA) expression. HSCs play a key role in the pathogenesis of hepatic fibrosis. We analyzed a mechanism leading to HSC activation by evaluating the role of oxidative stress and the expression of NFkB. In vitro study HSCs were proliferated (PCNA:2% vs 68%) and activated (alpha SMA: 5% vs 78%) by ascorbate/FeSO4, and HSCs activated by type I collagen were blocked (PCNA: 97% vs 4%, a SMA: 86% vs 9%) by a-tocopherol. In vivo study means of a SMA positive cells in liver at 400 x HPF were 48.3+/-5.2 and 15.2+/-1.8 and [3H]thymidine uptake of HSC was 529.2+/-284.8 cpm and 223.0+/-86.3 cpm in control and a-tocopherol treated group respectively at 32 hours after CCl4 injection. Nuclear extracts from activated, but not from quiescent, HSCs formed a complex with the NFkB cognate oligonucleotidesand alpha-tocopherol inhibited this bindings. This study indicates that oxidative stress plays an essential role through the induction of NFkB on HSC activation.

Constituents and the antitumor principle of Allium victorialis var. platyphyllum

To search for cytotoxic components from Allium victorialis, MTT assays on each extract and an isolated component, gitogenin 3-O-lycotetroside, were performed against cancer cell lines. Cytotoxicities of most extract were shown to be comparatively weak, though IC50 values of CHCl3 fraction was found to be <31.3-368.4 microg/ml. From the incubated methanol extract at 36 degrees C, eleven kinds of organosulfuric flavours were predictable by GC-MS performance. The most abundant peak was revealed to be 2-vinyl-4H-1,3-dithiin (1) by its mass spectrum. Further, this extract showed significant cytotoxicities toward cancer cell lies. Silica gel column chromatography of the n-butanol fraction led to the isolation of gitogenin 3-O-lycotetroside (3) along with astragalin (4) and kaempferol 3, 4'-di-O-beta-D-glucoside (5). This steroidal saponin exhibited significant cytotoxic activities (IC50, 6.51-36.5 microg/ml) over several cancer cell lines. When compound 3 was incubated for 24 h with human intestinal bacteria, a major metabolite was produced and then isolated by silica gel column chromatography. By examining parent- and prominent ion peak in FAB-MS spectrum of the metabolite, the structure was speculated not to be any of prosapogenins of 3, suggesting that spiroketal ring were labile to the bacterial reaction. These suggest that disulfides produced secondarily are the antitumor principles.

Role of Hck in the pathogenesis of encephalomyocarditis virus-induced diabetes in mice

Soluble mediators such as interleukin-1beta, tumor necrosis factor alpha (TNF-alpha), and inducible nitric oxide synthase (iNOS) produced from activated macrophages play an important role in the destruction of pancreatic beta cells in mice infected with a low dose of the D variant of encephalomyocarditis (EMC-D) virus. The tyrosine kinase signaling pathway was shown to be involved in EMC-D virus-induced activation of macrophages. This investigation was initiated to determine whether the Src family of kinases plays a role in the activation of macrophages, subsequently resulting in the destruction of beta cells, in mice infected with a low dose of EMC-D virus. We examined the activation of p59/p56(Hck), p55(Fgr), and p56/p53(Lyn) in macrophages from DBA/2 mice infected with the virus. We found that p59/p56(Hck) showed a marked increase in both autophosphorylation and kinase activity at 48 h after infection, whereas p55(Fgr) and p56/p53(Lyn) did not. The p59/p56(Hck) activity was closely correlated with the tyrosine phosphorylation level of Vav. Treatment of EMC-D virus-infected mice with the Src kinase inhibitor, PP2, resulted in the inhibition of p59/p56(Hck) activity and almost complete inhibition of the production of TNF-alpha and iNOS in macrophages and the subsequent prevention of diabetes in mice. On the basis of these observations, we conclude that the Src kinase, p59/p56(Hck), plays an important role in the activation of macrophages and the subsequent production of TNF-alpha and nitric oxide, leading to the destruction of pancreatic beta cells, which results in the development of diabetes in mice infected with a low dose of EMC-D virus.

Effect of protein kinase C inhibitor (PKCI) on radiation sensitivity and c-fos transcription

PURPOSE

The human genetic disorder ataxia-telangiectasia (AT) is a multisystem disease characterized by extreme radiosensitivity. Although ionizing radiation was known to induce c-fos transcription and cellular protein kinase C (PKC) induces the expression of this immediate response gene, little is known about how mutated AT (ATM) or PKC-mediated signal transduction pathway modulates the c-fos gene transcription and gene expression. Here we have studied the effect of PKC inhibitor (PKCI) on radiation sensitivity and c-fos transcription in normal and AT cells, and also studied whether PKCI effect on c-fos occurs in Ras-dependent pathway.

METHODS AND MATERIALS

Normal (LM217) and AT (AT5BIVA) cells were transfected with PKCI expression plasmid and integration and overexpression of PKCI was evaluated by polymerase chain reaction and northern blotting, respectively. Cells were irradiated at a dose of 5 Gy/min with 137Cs irradiator and harvested 48 h after irradiation and investigated apoptosis with TUNEL method. The c-fos transcription activity was studied by performing compute assisted tomography (CAT) assay of reporter gene after transfection of c-fos CAT plasmid into LM and AT cells. Overexpression of Ras protein in transfected cells was shown by western blotting.

RESULTS

Our results demonstrated for the first time a role of PKCI on the radiation sensitivity and c-fos transcription in LM and AT cells. PKCI increased radiation induced apoptosis in LM cells (5% to 20%) but reduced apoptosis slightly in AT cells. The basal c-fos transcription activity is 70 times lower in AT cells than in LM cells. This c-fos transcription activity was repressed by overexpression of PKCI in LM cells but not in AT cells. After induction of c-fos by Ras protein, overexpression of PKCI repressed c-fos transcription in LM cells but not in AT cells.

CONCLUSIONS

Overexpression of PKCI increased radiation sensitivity and repressed c-fos transcription in LM cells but not in AT cells, and this is related with Ras. These results suggest that the effect of PKCI on c-fos transcription activity is related with Ras dependent signal transduction pathways and these mechanisms are different between normal fibroblasts, LM and ATM mutated, AT cells. The data obtained by this study provided evidence for novel transcriptional difference between LM and AT cells and this may be a reason for increased radiation sensitivity of AT cells.

Temporary tattooing followed by Q-switched alexandrite laser for treatment of syringomas

BACKGROUND

Syringomas usually develop in women as multiple skin-colored papules primarily seen on the periocular regions and cheeks. They can cause cosmetic problems and lead to poor self-esteem. Though several treatment modalities have been established, such as excision, electro/cryosurgery, chemical peeling, and CO2 laser surgery, none of them are satisfactory due to their limitations and side effects, for example, pain, prolonged healing time, postoperative erythema/pigmentary changes, and scarring.

OBJECTIVE

The objective of this study was to develop a new treatment method for syringoma and to minimize the side effects through selective destruction of the tumor.

METHODS

Six patients with multiple periorbital syringomas were enrolled in this study. The surface epithelium of the syringomas was vaporized by CO2 laser, and black ink was introduced in order to allow penetration to the dermis using iontophoresis. Subsequently the artificial tattoos were removed by Q-switched alexandrite laser. The results were evaluated clinically by both physicians and patients at 1, 2, 4, and 8 weeks after treatment.

RESULTS

The majority of syringoma in the six patients disappeared by the first follow-up 1 week after treatment. There were no cases of prolonged erythema persisting beyond 2 weeks. Additional treatment was repeated in the same manner in order to remove the remaining syringomas in one patient. There were no recurrences during the 8-week follow-up period.

CONCLUSION

Our new treatment was safer, less painful, nonscarring, and there was a quicker recovery period and less of a burden to repeat treatment when necessary.

A cyclohexanonyl bromophenol from the red alga Symphyocladia latiuscula

From an extract of the red alga Symphyocladia latiuscula, a bromophenol (1) was isolated and characterized as (2R)-2-(2,3, 6-tribromo-4,5-dihydroxybenzyl)-cyclohexanone based on the spectroscopic evidence. The bromophenol was found to be a scavenger of 1,1-diphenyl-2-picrylhydrazyl radical.

Axial length in branch retinal vein occlusion

To determine the effects of axial length on the development of branch retinal vein occlusion (BRVO), determination of the affected eye, development of surgical complications, and visual prognosis, axial length was measured in 27 eyes each in surgical, non-surgical and control group and in 54 eyes each in occlusion (surgical + non-surgical group), non-affected eye (non-affected eyes of occlusion group), and non-occlusion group (both eyes of the control group). The average axial length was 22.61 mm in surgical, 22.48 mm in non-surgical, 23.09 mm in control, 22.55 mm in occlusion, 22.56 mm in non-affected eye, and 23.11 mm in non-occlusion group. The axial length showed a statistically significant difference between surgical and control group (p = 0.018), between non-surgical and control group (p = 0.002), and between occlusion and non-occlusion group (p < 0.001); however, no statistically significant difference was seen between surgical and non-surgical group, between non-affected eyes of surgical and non-surgical group, and between occlusion and non-affected eye group. Also, in such as BRVO groups as surgical, non-surgical, and occlusion groups, no correlation was present between axial length and degree of visual acuity recovery and final visual acuity. Although the possibility of developing BRVO is higher in those with short axial length, the axial length may have no relationship with the determination of the affected eye, visual prognosis and development of surgical complications.

Comparative evaluation of antioxidant potential of alaternin (2-hydroxyemodin) and emodin

The antioxidant activities of alaternin (2-hydroxyemodin) and emodin were compared for their respective potentials to inhibit lipid peroxidation in the linoleic acid system by the thiocyanate method, to inhibit total reactive oxygen species generation in kidney homogenates using 2',7'-dichlorodihydrofluorescein diacetate, to inhibit peroxynitrite formation by the 3-morpholinosydnonimine system, which generates superoxide radical and nitrogen monooxide, and to scavenge authentic peroxynitrites. Both alaternin and emodin were found to inhibit the peroxidation of linoleic acid by the thiocyanate method in a dose-dependent manner. Whereas the former shows inhibitory activities in reactive oxygen- and nitogen-mediated reactions, the latter does not. These results indicate that alaternin is a potentially effective and versatile antioxidant and can be used to protect biological systems and functions against various oxidative stresses.

Sesquiterpenes from the leaves of Ligularia fischeri var. spiciformis

From the leaves of Ligularia fischeri var. spiciformis, a new eremophilanolide, 8 alpha-methoxy-6-oxoeremophil-7(11)-en-12,8-olide (6-oxoeremophilenolide) and a eudesmane-type sesquiterpene, (+)-intermedeol were isolated. The structures were determined on the basis of 2D-NMR spectral data. Data on cytotoxicity showed that the latter was clearly more potent than the former compound.

Analytical procedure for quantifying five compounds suspected as possible contaminants in recycled paper/paperboard for food packaging

Because contaminants in recycled paper intended for food packaging could be a risk to public health, analytical methods are needed to identify and quantify residues of concern in paper/paperboard. The U. S. Food and Drug Administration is considering development of a guidance document for testing levels of contaminants that might be retained through paper recycling processes. An analytical procedure was developed using paper spiked with suspected contaminants at concentrations of 1-50 ppm in the paper. Benzophenone, dimethyl phthalate, anthracene, methyl stearate, and pentachlorophenol were introduced by soaking the paper in a solution in acetone at 25 degrees C for 24 h; the paper was removed and dried by evaporating the solvent with nitrogen. The model contaminant residues were extracted from the paper using ultrasonication and quantified by GC with flame ionization and electron capture detectors. Recoveries from the spiked paper were 80-109% with a repeatability of +/-4%. The method was also used to analyze commercial recycled paperboard to validate its applicability.

Effect of acidic environment and p53 on apoptosis induction by hyperthermia

The effect of environmental acidity on the induction of apoptosis by heat was investigated. Human colorectal tumour RKO.C cells, carrying wild-type p53 and isogenic RC10.1 cells deficient in p53, were heated at 42.0 degrees C for 1 h in pH 7.5 or pH 6.6 medium and the apoptosis was assessed based on the flow cytometic determination of DNA content, DNA fragmentation, and PARP cleavage. The degree of apoptosis after heating in pH6.6 medium was greater than that in pH 7.5 medium in both RKO.C cells and RC10.1 cells. When heated in the same pH medium, more apoptosis occurred in the RC10.1 cells than in the RKO.C cells. Heating increased the expression of p53 protein and p21 protein markedly in RKO.C cells and slightly in RC10.1 cells. Expression of these proteins was slightly greater in pH 7.5 medium than in pH 6.6 medium. The expressions of Bax protein and Bcl-2 protein, which are known to control apoptosis, were not altered by heating. It was concluded that an acidic environment enhances heat-induced apoptosis. It was also concluded that heat-induced apoptosis is lessened by p53 and that Bcl-2 and Bax are not involved in the induction of apoptosis by hyperthermia.

A case of extragenital lichen sclerosus following Blaschko's lines

Extragenital lichen sclerosus is most common on the neck, shoulders, and upper portion of the trunk. A 20-year-old Korean man had asymptomatic, well-demarcated, linear violaceous plaques on the left lateral chest, in a pattern corresponding to the lines of Blaschko. We describe a case with a pattern of extragenital lichen sclerosus following Blaschko's lines.

Granulomatous pyoderma gangrenosum: two unusual cases showing necrotizing granulomatous inflammation

We present two cases of pyoderma gangrenosum (PG) with unusual histopathological findings. The main histopathological feature of PG is usually massive neutrophilic infiltration; the neutrophil is thus the cytologic hallmark of PG. The occurrence of vasculitis is controversial. In our patients, in contrast, biopsy specimens revealed extensive granulomatous inflammation with massive tissue necrosis throughout the entire dermis and subcutaneous tissue and vascular involvement simulating many other granulomatous diseases. However, there was no evidence of systemic disease. Our cases may therefore represent a histopathologically distinct subset of PG.

Secondary correction of unsatisfactory blepharoplasty: removing multilaminated septal structures and grafting of preaponeurotic fat

Oriental blepharoplasty, commonly known as a "double eyelid operation," is the most frequently practiced cosmetic procedure in Orientals, who have probably become more fold conscious because of social westernization and an influx of Caucasians into their society. Anatomically, the upper eyelids of an Oriental are considerably different from those of a white person, and nearly half of Orientals have single eyelids. When performing blepharoplasty, an appropriate design and operative technique must be carefully selected, taking into consideration the anatomical characteristics of Koreans to obtain an aesthetically pleasing result. However, the incidence of complications is high. Patients who are faced with unsatisfactory results are often perplexed by the fact that such a commonly performed procedure could have a very high rate of dissatisfaction and that an improvement is not easy. An unfavorable result need not imply a postoperative complication, but only that the result is not acceptable to the patient, whose goal may not be based on good aesthetic principles. The most common sources of dissatisfaction are postoperative asymmetry and high placement of the lid fold. From 1991 to 1998, secondary blepharoplasty was performed on 72 patients by slitting transversely, removing the multilaminated septal structures exposed to the previous operative scar, spreading the preaponeurotic fat that extruded, and removing the septal structures into a space where the scar was eliminated to prevent secondary adhesion. The average age of the patients was 26.5 years, and the average follow-up period was 2 years. No remarkable complication was encountered after operation with this method, and the desired aesthetic improvements were achieved in the majority of the patients.

Automated sleep stage scoring using hybrid rule- and case-based reasoning

We propose an automated method for sleep stage scoring using hybrid rule- and case-based reasoning. The system first performs rule-based sleep stage scoring, according to the Rechtschaffen and Kale's sleep-scoring rule (1968), and then supplements the scoring with case-based reasoning. This method comprises signal processing unit, rule-based scoring unit, and case-based scoring unit. We applied this methodology to three recordings of normal sleep and three recordings of obstructive sleep apnea (OSA). Average agreement rate in normal recordings was 87.5% and case-based scoring enhanced the agreement rate by 5.6%. This architecture showed several advantages over the other analytical approaches in sleep scoring: high performance on sleep disordered recordings, the explanation facility, and the learning ability. The results suggest that combination of rule-based reasoning and case-based reasoning is promising for an automated sleep scoring and it is also considered to be a good model of the cognitive scoring process.

Hypoglycemic and hypolipidemic effects of tectorigenin and kaikasaponin III in the streptozotocin-lnduced diabetic rat and their antioxidant activity in vitro

Tectorigenin and kaikasaponin III from the flowers of Pueraria thunbergiana showed potent hypoglycemic and hypolipidemic effects in the streptozotocin-induced diabetic rats. Intraperitoneal administration of these two compounds with 5 and 10 mg/kg, respectively, for seven days to streptozotocin-induced rats significantly reduced the blood glucose, total cholesterol, LDL- and VLDL-cholesterol and triglyceride levels when compared with those of control group. Glycitein in which 5-OH is unlinked and tectoridin (7-O-glycoside of tectorigenin) isolated from the flowers of P. thunbergiana did not improve hyperglycemia and hyperlipidemia. In addition, tectorigenin showed in vitro antioxidant effects on 1,1diphenyl-2-pirylhydrazyl (DPPH) radical, xanthine-xanthine oxidase superoxide anion radical, and lipid peroxidation in rat microsomes induced by enzymatic and non-enzymatic methods. We further found that tectorigenin and kaikasaponin III protected the Vero cell line (normal monkey kidney) from injury by hydrogen peroxide. From these findings, it seems likely that the antioxidant action of tectorigenin and kaikasaponin III may alleviate the streptozotocin-induced toxicity and contribute to hypoglycemic and hypolipidemic effects.

Effects of gamma-aminobutyric acid on secretagogue-induced exocrine secretion of isolated, perfused rat pancreas

Because GABA and its related enzymes have been determined in beta-cells of pancreas islets, effects of GABA on pancreatic exocrine secretion were investigated in the isolated, perfused rat pancreas. GABA, given intra-arterially at concentrations of 3, 10, 30, and 100 microM, did not exert any influence on spontaneous or secretin (12 pM)-induced pancreatic exocrine secretion. However, GABA further elevated CCK (10 pM)-, gastrin-releasing peptide (100 pM)-, or electrical field stimulation-induced pancreatic secretions of fluid and amylase dose dependently. The GABA (30 microM)-enhanced CCK-induced pancreatic secretions were completely blocked by bicuculline (10 microM), a GABA(A) receptor antagonist, but were not affected by saclofen (10 microM), a GABA(B) receptor antagonist. The enhancing effects of GABA (30 microM) on CCK-induced pancreatic secretions were not changed by tetrodotoxin (1 microM) but were partially reduced by cyclo-(7-aminoheptanonyl-Phe-D-Trp-Lys-Thr[BZL]) (10 nM), a somatostatin antagonist. In conclusion, GABA enhances pancreatic exocrine secretion induced by secretagogues, which predominantly induce enzyme secretion, via GABA(A) receptors in the rat pancreas. The enhancing effect of GABA is partially mediated by inhibition of islet somatostatin release.

Gossypol-induced DNA breaks in rat lymphocytes are secondary to cytotoxicity

Gossypol, a male antifertility and potential anticancer agent, was found to induce DNA strand breaks in rat lymphocytes. DNA breaks were measured with the single-cell gel electrophoresis (SCGE) or 'comet' assay. A significant increase in DNA breaks was observed after 1 h incubation at concentrations of 2 microg/ml or greater. The inclusion of 10% fetal bovine serum in the media reduced the toxicity of gossypol, and DNA breaks were only observed at a concentration of 80 microg/ml. However, the increase in DNA strand breaks, for incubations with and without serum, only occurred when cell viability was reduced to less than 70%. Examination of cell morphology and DNA fragmentation at incubations up to 5 h yielded no evidence that DNA strand breaks were occurring due to apoptosis. We conclude that gossypol is not primarily genotoxic in this cell type, and that the DNA breaks observed arose secondary to cytotoxicity.

Connexin26 mutations associated with nonsyndromic hearing loss

OBJECTIVE

Mutations in the GJB2 gene are a major cause of autosomal recessive and sporadic types of congenital deafness. The 35delG mutation is the most frequent type of mutation in white populations. However, several other forms were reported, such as 167delT among Ashkenazi Jews and R143W in Africans. The present study investigated the mutations of connexin26 (Cx26) found in patients with nonsyndromic hearing loss (NSHL) and newborns in the Korean population.

STUDY DESIGN

The sequencing data for 147 unrelated patients with congenital NSHL and 100 audiologically screened newborns were included in this prospective study.

METHODS

Genomic DNA samples from all patients and newborns were sequenced in both directions for detection of Cx26 mutations.

RESULTS

Thirteen different types of mutations were found in the patients and newborns. V27I and E114G are the popular types of polymorphic mutations in both groups. 235delC-deletion and frameshift--was detected in patients (15 in 294 alleles) and newborns (1 in 200 alleles). 35delG was rarely found in both group. In addition to above mutations, several types of mutations--S85P, K41R, S72C, V84A, 176-191del, and 299-300del-were identified. The family study of the 235delC showed a typical autosomal recessive trait of NSHL in their audiological evaluation of hearing threshold.

CONCLUSION

The frequency of 235delC allele showed much higher in the patients (5%) than in newborns (0.5%). We rarely found 35delC mutant in both groups. These results suggest that the different types of Cx26 mutations affect autosomal recessive NSHL according to ethnic background.