Roles of acetyl-CoA carboxylase beta in muscle cell differentiation and in mitochondrial fatty acid oxidation

Acetyl-CoA carboxylase beta is expressed primarily in heart and skeletal muscle, where it may play a role in the control of mitochondrial fatty acid uptake and oxidation by controlling carnitine-palmitoyl-CoA transferase 1. To investigate the relationship between ACC-beta expression and myoblast differentiation, we specifically blocked ACC-beta production by expressing an antisense gene to the specific N-terminal region of ACC-beta in H9c2 cells. The expression of the antisense ACC-beta mRNA retarded cell fusion, myosin formation, and creatine kinase induction; all of these parameters are hallmarks of muscle cell differentiation. On the other hand, the rate of fatty acid oxidation was not affected by the presence or absence of ACC-beta in the cells.

Clinical significance of intrahepatic biliary stricture in efficacy of hepatic resection for intrahepatic stones

In the Far East, hepatic resection is the definitive treatment for complicated intrahepatic stones (IHS). However, many investigators have reported that the associated intrahepatic biliary stricture is the main cause of treatment failure. A retrospective comparative study was undertaken to clarify the long-term efficacy of hepatic resection for treatment of IHS and to investigate the clinical significance of intrahepatic biliary stricture in treatment failure after hepatic resection performed in 44 patients with symptomatic IHS. The patients were divided into two study groups: group A, with intrahepatic biliary stricture (n = 28) and group B, without stricture (n = 16). Residual or recurrent stones, recurrence of intrahepatic biliary stricture, late cholangitis, and final outcomes were analyzed and compared statistically between the two groups. The patients were followed up for a median duration of 65 months after hepatectomy. The overall incidence of residual or recurrent stones was 36% and 11%, respectively, in groups A and B. The initial treatment failure rate was 50% in group A and 31% in group B. Intrahepatic biliary stricture recurred in 46% of patients in group A, while none of the group B patients had biliary stricture recurrence (P = 0.001). More than two-thirds of the restrictures in group A were identified at the primary site. The incidence of late cholangitis was higher in group A (54%) than in group B (6%) (P = 0. 002). Three-quarters of the patients with cholangitis in group A had severe cholangitis, that was recurrent, and related to stones and strictures (n = 11). They and 2 asymptomatic patients in group B required secondary procedures done at a median of 12 months after hepatectomy. Final outcomes after hepatectomy with or without secondary management were good in 80%, fair in 16%, and poor in 4% of our 44 patients. Most recurrent cholangitis after hepatectomy in patients with IHS was related to recurrent intrahepatic ductal strictures. Therefore, to be effective, hepatic resection should include the strictured duct. However, with hepatectomy alone it is difficult to clear the IHS or relieve the ductal strictures completely, particularly in patients with bilateral IHS, so perioperative team approaches that include both radiologic and cholangioscopic interventions should be combined for the effective management of IHS.

The effect of prostaglandin and its inhibitor on antibody-dependent cellular cytotoxicity against human squamous cell carcinoma of head and neck

The effects of chimeric monoclonal antibodies (cMAbs), prostaglandin E2(PGE2), and indomethacin (INDO) on antibody-dependent cellular cytotoxicity (ADCC) against human squamous cell carcinoma of head and neck (SCCHN) cell line were examined. Using the PCI-50 SCCHN cell line as target and normal human peripheral blood mononuclear cells as the effector, ADCC was enhanced by the treatment of cMAbs (1.25 micrograms/ml), but was inhibited by exogenous PGE2(5 x 10-7M). The effects of cMAb and PGE2 were dose-dependent. Maximal suppression of activity occurred when PGE2 was present during the entire 4 hour 51Cr-release assay period, whereas pretreatment of effector cells with PGE2 had minimal inhibitory effect after washing. These results indicate that decreased ADCC seen with SCCHN targets treated with PGE2 is related to post-binding events, such as binding of effector and target cells. Pre-treatment of effector cells with INDO (1 microgram/ml) resulted in restoration of NK activity which was inhibited by PGE2. Our in vitro results suggest that INDO can increase tumor cell killing by the reversal of the suppression for many immune functions by PGE2.

Representation of nociceptive stimuli in primary sensory cortex

Using fMRI, we observed cortical activity associated with nociceptive hot and cold sensations applied to hand and foot that are not spatially restricted to the corresponding regions of the primary somatosensory cortex (SI). Hot (55-57 degrees C) and cold (0-2 degrees C) tactile stimuli were applied separately to the right hand and foot of eight right-handed subjects. Although somatotopic mapping of hand and foot was observed as expected based on the Penfield homunculus, activations associated with hot during both hand and foot stimulation and subsequently, cold, activated regions unique to each thermal modality irrespective of the body part. This distributed system for thermal information is present at both nociceptive and more neutral thermal intensities (i.e. warm and cool sensations) indicating the presence of distributed sensory processing associated with thermal-related sensations in human primary sensorimotor cortex.

Characterization of FEN-1 from Xenopus laevis. cDNA cloning and role in DNA metabolism

cDNAs for the Xenopus laevis homologue of the endo/exonuclease FEN-1 (DNase IV) have been cloned using a polymerase chain reaction strategy. Products were obtained from two nonallelic Xenopus genes (xFEN-1a and xFEN-1b) that differ from each other by 4.5% in amino acid sequence. Both are 80% identical to mammalian FEN-1 proteins and 55% identical to the yeast homologues. When expressed in Escherichia coli, the Xenopus enzymes showed flap endonuclease activity, a unique feature of this class of nucleases. In addition, expression from the Xenopus cDNAs complemented the temperature and methyl methanesulfonate sensitivity of a yeast rad27 deletion, which eliminates the endogenous FEN-1 gene product. Antiserum raised against xFEN-1 was used to show that the protein accumulates during the middle and late stages of oogenesis, in parallel with other DNA metabolic activities, and that it is localized to the oocyte nucleus. Flap endonuclease activity was demonstrated in oocyte nuclear extracts, and this was inhibited by the anti-xFEN-1 antiserum. The antiserum did not inhibit the major oocyte 5' --> 3' exonuclease activity. DNA synthesis in oocyte extracts was blocked by the antiserum, and the nature of this inhibition suggests that xFEN-1 may be part of a large complex of replication factors. Chromatographic evidence was obtained for the existence of a complex that forms during DNA synthesis and includes proliferating cell nuclear antigen in addition to xFEN-1. These observations support a critical role for xFEN-1 in DNA replication, but indicate that another enzyme must be responsible for the exonuclease function required for homologous recombination in Xenopus oocytes.

Stem-loop structure in the 5' region of potato virus X genome required for plus-strand RNA accumulation

Computer-generated thermodynamic predictions and solution structure probing indicated two stem-loop structures, stem-loop 1 (SL1; nt 32-106) and stem-loop 2 (SL2; nt 143-183), within the 5' 230 nt of potato virus X (PVX) RNA. Because the existence of SL1 was further supported by covariation analysis of several PVX strains, the functional significance of this structure was investigated by site-directed mutational analysis in a tobacco protoplast system. In general, mutations that reduced genomic plus-strand RNA accumulation similarly affected coat protein accumulation, indicating that subgenomic plus-strand RNA was also affected. In contrast, minus-strand RNA levels remained relatively unchanged. Mutational analysis of the stem C (SC) region of SL1 indicated that pairing was more important than sequence, which was consistent with the covariation analysis. Alterations that increased length and stability of either SC or stem D (SD) were deleterious to plus-strand RNA accumulation. The formation of internal loop C between SC and SD, as well as specific nucleotides within this loop, were also required. Several modifications were made to the terminal GAAA tetraloop, a motif known for enhanced RNA stability. Both GANA and GAAG motifs resulted in wild-type levels of RNA accumulation. However, a UUCG tetraloop was detrimental, indicating that the sequence of this element was important beyond just providing stabilization of the structure. These data indicate that multiple features of SL1 are critical for accumulation of PVX plus-strand RNA.

Determination of aloesin in plasma by high-performance liquid chromatography as fluorescent 9-anthroyl derivative

A sensitive high-performance liquid chromatographic (HPLC) method for the determination of aloesin in plasma was developed. After solid-phase extraction from plasma and derivatization of aloesin and compound AD-1, which was prepared from aloesin as a internal standard, with 9-anthroylnitrile in the presence of quinuclidine, the derivatives were separated on a inertsil ODS-3 column using acetonitrile/methanol/water (3:1:6) as a mobile phase, and detected fluorimetrically at 460 nm with excitation at 360 nm. The detection limit of aloesin was 3.2 ng/ml in plasma (S/N = 3).

The significance of CT scan or MRI in the evaluation of salivary gland tumors

Imaging modalities such as CT scan or MRI are frequently employed for the diagnosis of neoplastic lesions in the salivary glands. To evaluate the efficacy of the CT scan and the MRI in differentiating malignant neoplasm from benign lesions, 120 CT scans and 31 MRIs were retrospectively analyzed from 147 patients with salivary gland masses. All images were analyzed focusing on the presence of several relevant features. The pathologic results were matched with radiological features and also tabulated with radiological assessment. For the CT scans, the contour and margin of the lesion and tissue plane obliteration were found to be statistically significant indicators for malignant neoplasms. Among 69 CT scans interpreted as 'benign' by a radiologist, five cases (7%) were histologically diagnosed as 'malignant'. On the other hand, 20 out of 51 CT scans (39%) were misinterpreted as 'malignant'. For MRI, two out of 14 cases (14%) were radiologically misdiagnosed as 'benign' and six out of 17 patients (35%) as 'malignant'. In conclusion, whereas both the CT and MRI showed a similar level of accuracy in evaluation of salivary gland tumors, they showed a considerable tendency of misdiagnosis, especially by interpreting benign tumors as 'malignant'.

Synthesis and evaluation of 2-amino-6-fluoro-9-(2-hydroxyethoxymethyl)purine esters as potential prodrugs of acyclovir

2-Amino-6-fluoro-9-(2-hydroxyethoxymethyl)purine (2) and its ester derivatives 4a-d were synthesized as potential prodrugs of acyclovir, and were evaluated for their oral acyclovir bioavailability in rats and in vivo antiviral efficacy in HSV-1-infected mice. Treatment of 2-amino-6-chloro-9-(2-hydroxyethoxymethyl)purine (3) with trimethylamine in THF/DMF (4:1) followed by a reaction of the resulting trimethylammonium chloride salt 5 with KF in DMF gave 2 in 78% yield. Esterification of 2 with an appropriate acid anhydride (Ac2O, (EtCO)2O, (n-PrCO)2O, or (i-PrCO)2O) in DMF in the presence of a catalytic amount of DMAP at room temperature produced the esters 4a-d in 90-98% yields. Of the prodrugs tested in rats, the isobutyrate 4d achieved the highest mean urinary recovery of acyclovir (51%) that is 5.7-fold higher than that of acyclovir (9%) and comparable to that of valacyclovir (50%). The prodrug 4d protected dose-dependently the mortality of HSV-1-infected mice, and the group treated with 4d at a dose of 400 mg/kg showed the longest mean survival day (14.6+/-3.1 days) (mean+/-S.D.).

Effect of nitric oxide on hydrogen peroxide-induced damage in isolated rabbit gastric glands

The present study aims at investigating the effects of nitric oxide (NO) on hydrogen peroxide (H2O2)-induced damage in isolated rabbit gastric glands. NO synthesis modulators such as L-arginine and NG-nitro-L-arginine methyl ester (L-NAME) and an NO donor, sodium nitroprusside, were added to isolated rabbit gastric glands exposed to H2O2, generated by glucose oxidase acting on beta-D-glucose. As a result, glucose/glucose oxidase caused an increase in lipid peroxide production and decreases in reduced glutathione (GSH) content, GSH peroxidase activity, nitrite release, and mucus secretion in gastric glands. The alterations in lipid peroxide production, GSH content, and mucus secretion were prevented by pretreatment with L-arginine, a substrate for NO synthase and sodium nitroprusside, but not by L-NAME. In conclusion, NO protects gastric glands from H2O2 by inhibiting lipid peroxidation and maintaining cellular GSH content and mucus secretion.

Infection rate of Leptospira interrogans in the field rodent, Apodemus agrarius, in Korea

Leptospirosis has significantly decreased in Korea since 1988, following the leptospiral vaccination programme initiated in 1988. Whether this wholly explains the decreased incidence is uncertain. As an initial step to answer this question, infection rates of Leptospira interrogans in field rodents, Apodemis agrarius, were examined and compared with previous data. Two hundred and twenty-two A. agrarius were captured during October-December 1996. Spirochaetes were isolated from 22 (9.9%) and leptospiral DNA was detected in an additional 6 rodents (12.6%). Subsequent microscopic agglutination tests (MAT) classified all these isolates as L. interrogans serogroup Icterohaemorrhagiae serovar lai. The above data did not significantly differ from previous surveys in 1984-7. There was no significant change of L. interrogans infection in field rodents following the introduction of the vaccination programme in Korea. Further studies are needed to determine the role of human vaccination in reducing incidence.

Heterogeneity of human papillomavirus DNA in a patient with Bowenoid papulosis that progressed to squamous cell carcinoma

Bowenoid papulosis (BP) of the genitalia, characterized by the histological findings of a squamous cell carcinoma, follows a largely benign clinical course. The detection of oncogenic human papilloma viruses (HPV) from BP points to an aetiological role of these viral infections. A 47-year-old man with multiple genital skin lesions was seen over a 10-year period with the diagnosis of BP. Recently, he attended again with a recurrent genital tumour that was diagnosed as squamous cell carcinoma. His genital lesions progressed and became polymorphic in appearance, from a wart-like tumour to a reddish invasive plaque. To screen for the presence of different HPV sequences from different skin lesions and to correlate each HPV type with distinct clinical manifestations, polymerase chain reaction and single-strand conformational polymorphism (PCR-SSCP) were performed. PCR-SSCP revealed the presence of several types of HPV from different genital lesions. Sequencing results disclosed that he had a mixed infection of HPV6b, HPV16, HPV18 and HPV33, respectively. Interestingly, the clinical findings were fairly well correlated with the oncogenic potential of HPV found from each lesion.

Generation of multiorder Stokes and anti-Stokes lines in a Brillouin erbium-fiber laser with a Sagnac loop mirror

We have demonstrated a novel multiwavelength lasing scheme in which a Brillouin erbium-fiber laser with a Sagnac loop mirror and a metal-coated planar mirror were used. The Sagnac loop permitted the simultaneous presence of a stimulated Brillouin scattering (SBS) pump and Stokes lines within the loop and thus generated high-order Stokes and anti-Stokes waves through a four-wave mixing (FWM) process. A total of 34 lines of Stokes and anti-Stokes waves with 0.08-nm line spacing was generated through the SBS and FWM processes with 1.5-mW SBS pump power at 1561 nm and 80-mW erbium-doped-fiber pump power.

Inhibitory effect of ginsenoside on the mediator release in the guinea pig lung mast cells activated by specific antigen-antibody reactions

We reported that some components of ginsenosides decreased mediator release which was evoked by the activation of mast cells caused by specific antigen-antibody reactions. This study aimed to assess the effects of ginsenoside, Rb1, which belongs to the protopanaxadiol, on the mechanism of mediator release during mast cell activation. Pretreatment of Rb1 (100 microg) significantly decreased histamine and leukotriene in a dose-dependent manner during mast cell activation. The PLD activity during mast cell activation decreased in the pretreatment of Rb1 (300 microg). The amount of DAG produced by PLC activity decreased because of Rb1 pretreatment. The amount of mass DAG decreased due to Rb1 pretreatment during mast cell activation. Rb1 (300 microg) pretreatment strongly inhibited the incorporation of the [3H]methyl moiety into phospholipids. The data suggest that Rb1, purified from Korean Red Ginseng Radix, inhibits an increase of DAG production during mast cell activation caused by antigen-antibody reactions, which is mediated via phosphatidylcholine-PLD and phosphatidylinositol-PLC systems. This is then followed by the inhibition of histamine releases. Furthermore, Rb1 reduces the phosphatidylcholine production by inhibiting the methyl-transferase I and II, and the reduction of phosphatidylcholine production inhibits leukotriene release.

Characterization of coronavirus DI RNA packaging

Studies of defective interfering (DI) RNAs of mouse hepatitis virus (MHV), suggest that a 69 nt-long packaging signal, which is located about 20 kb from the 5'-end of the 31 kb-long MHV genomic RNA, is necessary and sufficient for MHV genomic RNA packaging into MHV particles. We demonstrated that use of a low pH culture medium combined with subsequent ultrafiltration increased MHV infectivity about 60 times over MHV preparations grown in neutral medium. Using this virus concentration procedure, we successfully prepared DI particle-rich MHV preparations. Characterization of virus samples released from the cells infected with DI particle-rich MHV revealed that infectious MHV genomic RNA was not required for packaging of DI RNAs. These data suggested that interaction of the DI packaging signal with an unidentified region(s) of helper virus genomic RNA is unlikely, and therefore unlikely to facilitate the packaging of MHV DI RNA into the MHV virion. Rather, both DI RNA and MHV genomic RNA probably use the packaging signal for RNA packaging.

Sequence element required for efficient -1 ribosomal frameshifting in red clover necrotic mosaic dianthovirus

The RNA-1 of the bipartite red clover necrotic mosaic dianthovirus (RCNMV) genome encodes the 88-kDa polymerase. The polymerase is translated from both 5' proximal and internal open reading frames by a -1 ribosomal frameshifting event. A shifty heptanucleotide conforming to the simultaneous slippage model is identified, and a downstream stem-loop structure and atypical pseudoknot are predicted. A beta-glucuronidase reporter assay identified a 118-nucleotide element containing both the shifty heptanucleotide and the predicted secondary structures that were required for efficient -1 ribosomal frameshift expression in vivo. A series of site-directed and compensatory mutations affecting the base-paired regions of the predicted secondary structure were introduced into a RCNMV RNA-1 cDNA clone from which infectious transcripts were derived. Mutations that destroyed the predicted pseudoknot had no effect on frameshifting efficiency in vitro or infectivity of the virus, whereas mutations destabilizing the stem-loop structure abolished both ribosomal frameshifting in vitro and biological activity. These results demonstrate the essential role of a predicted secondary structure that does not involve a pseudoknot in the expression of the RCNMV polymerase by ribosomal frameshifting.

Angular and Speckle Multiplexing of Photorefractive Holograms by use of Fiber Speckle Patterns

The scheme of using fiber speckle patterns can be applied to the multiplexing of photorefractive holograms. Fiber speckle referencing enhances the angular selectivity of the holograms. Speckle multiplexing is also possible by use of a mode scrambler. Also studied is the feasibility of a hybrid scheme involving simultaneous shift and speckle multiplexing.

Comparative activities of novel beta-lactamase inhibitors, 6-exomethylene penamsulfones (CH1240, CH2140) in experimental mouse infection model

The antibacterial activity of novel beta-lactamase inhibitors, 6-exomethylene penamsulfones (CH1240, CH2140), has been compared in vivo with that of sulbactam and clavulanic acid against beta-lactamase producing strains. In vivo microbiological assessment was used as experimental mouse infection model by gram negative strains. Against Pseudomonas aeruginosa F0013, cefoperazone/CH1240 was slightly less active than sulbactam. Ampicillin/CH1240 was more active than sulbactam against Citrobacter diversus species. That of ampicillin/CH2140 was less effective than sulbactam against Escheriachia coli 3457. Especially against Citrobacter diversus 2046E, amoxicillin/CH2140 was the most potent and amoxicillin/CH1240 was slightly more active than clavulanic acid. Consequently the difference in efficacy between the drug combinations appears to be related to the degree of protection afforded the animals by the beta-lactamase inhibitors. CH1240 and CH2140 are promising new agents and should undergo further investigations.

The development of a new method to detect the adulteration of commercial aloe gel powders

Simple and accurate methods to detect the adulteration of commercial aloe gel powder were developed. Crude polysaccharide in aloe gel powder was isolated by precipitating with excess ethyl alcohol and total hexose in isolated polysaccharide was determined by Dubois assay. After hydrolysis of non-dialysable polysaccharides, resultant free sugar was determined by gas chromatography for sugar recognition and ash contents was considered simultaneously. In some products, the content of ash was very low while the content of total hexose was very high. And polysaccharides of these products revealed typical dextran pattern, therefore, these products could be identified that adulterated with commercial maltodextrin. The content of maltodextrin in adulterated product was determined by HPLC and TLC analysis which could be adopted as a part of a certification process.

Locoregional response and increased natural killer activity after intratumoral injection of HLA-B7/beta2-microglobulin gene in patients with cancer

The purpose of this study was to assess the therapeutic potential of injecting the gene for HLA-B7/beta2-microglobulin into the subcutaneous metastatic nodules of patients who are refractory to conventional treatments. The nine patients evaluated were divided into three groups and given escalating doses of DNA (20, 40, and 100 microg of the HLA-B7 plasmid DNA/lipid complex for each group) every 2 weeks. Biopsy specimens from the treated tumor nodules of all nine patients were positive for the presence of DNA and for HLA-B7 mRNA expression. Moreover, in six of the nine patients, immunohistology of tumor biopsy samples revealed the expression of recombinant HLA-B7 protein. Also, all nine patients showed an increase in NK activity in their circulating peripheral blood lymphocytes. In two lung cancer patients, one partial and one mixed response was observed after gene transfer. These responses were confined to the treated nodules and the untreated locoregional lymph nodes; the lung masses showed no regression. Remission durations were 14 and 6 weeks, respectively, and in a total of 35 cycles no significant toxicities were observed. Immunohistologic analysis revealed an increased infiltration of CD4+ T cells, macrophages, and NK cells after therapy. In two responding cases, direct intratumoral injection of an allogeneic class I gene could elicit an antitumor response in locoregional areas, possibly through the activation of NK cells.

A case of nodular cystic fat necrosis: the end stage lesion showing calcification and lipomembranous changes

Nodular cystic fat necrosis, first described by Przyjemski et al. in 1978, is a distinct, benign subcutaneous lesion characterized histologically by encapsulated fat necrosis. We report a case of nodular cystic fat necrosis in a 22-year-old man who had had two mobile, rice-sized, deep-seated papules on his right shin for ten years after trauma. Histologically, the excised mass showed encapsulated fat necrosis, calcification, and lipomembranous changes. The encapsulation of necrotic tissue may prevent further extension of adiponecrosis. The subcutaneous fat is prone to trauma or ischemia. The observation of lipomembranous changes in nodular cystic fat necrosis seems to support the concept that lipomembranous change is a nonspecific pattern of the fat necrosis due to multiple local or systemic events causing a compromise in the blood supply of the subcutaneous tissue.

Neoplagioporus zacconis (Trematoda: Opecoelidae) from the intestine of the pale chub, Zacco platypus, in Korea

Neoplagioporus zacconis (Yamaguti, 1934) (Trematoda: Opecoelidae) was found from the intestine of the pale chub, Zacco platypus, for the first time in Korea. The worms were characterized morphologically by oval body shape, bipartited seminal vesicle, sinistrally located genital pore, and lobed ovary, and distinguished from the two other species of Neoplagioporous by body shape and distribution of vitelline follicles. The morphological characteristics, except the ovary, well corresponded to those of the previous descriptions. The morphological difference of the ovary was considered as a character of geographical phenotypic variation.

Overexpression and characterization of the cDNA encoding the coat protein of cucumber mosaic virus (Strain ABI) isolated in Korea

We constructed a recombinant CMVCP expression vector termed pMALCMV in which cDNA fragment encoding CMVCP is ligated into pMAL-c2, an E. coli expression vector. Overexpression of pMALCMV containing the entire open reading frame of CMV cDNA sequence and the maltose binding protein (MBP) leader gene was facilitated in E. coli TB1 cells, which resulted in the production of a fusion protein of MBP-CMVCP (Mr 67.7 kDa) that was immunoprecipitable with rabbit polyclonal antiserum specific for MBP. The CMVCP (Mr 24.5 kDa) was isolated through a preparative SDS polyacrylamide gel following digestion of the affinity ligand purified fusion protein with Factor Xa. The partial amino acid sequences of the cleaved proteins were confirmed at the amino terminus by peptide sequencing. The CMVCP antiserum was also prepared by intraperitoneal injection of this purified CP into a BALB/c mouse. Immunoblot analysis showed that the purified CMVCP from the Factor Xa cleavage reaction was an authentic overexpression product of the cloned CMVCP. Using an RNA mobility shift assay, it was demonstrated that CMVCP can bind to its own RNA transcript in a concentration dependent manner. However, the complex formed between CMVCP and its RNA was abolished by the addition of a polyclonal antibody that had been raised against CMVCP, confirming that the overexpressed CMVCP specifically interacts with its own RNA. Thus, our results can provide a basis for the development of a hybridoma cell line expressing the monoclonal antibody for CMVCP and molecular cloning of their genes, which may lead to the creation of CMV-resistant transgenic plants.