Baseline glycated albumin level and risk of type 2 diabetes mellitus in Healthy individuals: a retrospective longitudinal observation in Korea

Glycated albumin (GA) reflects glycemic status for the past three weeks. GA level demonstrates a strong correlation with HbA1c level and is used as an adjunctive biomarker for diagnosis and monitoring of type 2 diabetes mellitus (T2DM). In this study, we validated the predictive performance of baseline GA for development of T2DM in healthy individuals in Korea. From August 2013 to September 2014, the medical records of 3,771 healthy Koreans were retrospectively reviewed. Each participant was categorized into tertiles based on initial GA level. During the follow-up period through May 2020, study participants were evaluated for T2DM using HbA1c, fasting glucose level, and a self-reported diagnosis history. Baseline GA level by tertile (T1 to T3) was 10.4 ± 0.8% (mean ± SD), 12.1 ± 0.3%, and 13.7 ± 0.9%, respectively. The median follow-up was 5.97 years, during which 4.9% (186 of 3,771) of the participants developed T2DM. After adjusting for confounding factors, the hazard ratio for the development of T2DM in the highest GA level group (T3) compared to the reference group (T1) was 2.46 (95% CI, 1.7 to 3.58, p < 0.001 for trend) with a Harrell's C index of 0.80 (95% CI, 0.76 to 0.83). Also, within highest group of baseline HbA1c and FG levels, higher GA levels were associated with an increased HRs for T2DM. In conclusion, Our study confirms that the risk of T2DM increases with baseline GA level. Additional follow-up of the cohort is warranted to investigate the correlations between GA and other clinical indicators including diabetic complications.

Polysaccharides from Korean Citrus hallabong peels inhibit angiogenesis and breast cancer cell migration

Although the peel of the hallabong (Citrus sphaerocarpa) fruit is rich in polysaccharides, which are valuable dietary ingredients for human health, it is normally wasted. The present study aimed to utilize the peel waste and identify properties it may have against breast cancer metastasis. Hallabong peel extract containing crude polysaccharides was fractionated by gel permeation chromatography to produce four different polysaccharide fractions (HBE-I, -II, -III, and -IV). The HBE polysaccharides significantly blocked tube formation of human umbilical vein vascular endothelial cells (HUVECs), at a concentration of 12.5 or 25 μg/mL. Tube formation appeared to be more sensitive to HBE-II than to other HBE polysaccharides. HBE-II also inhibited breast cancer cell migration, through downregulation of matrix metalloproteinase-9 (MMP-9) in MDA-MB-231 triple-negative breast cancer cells. Therefore, inhibition of tube formation and MMP-9-mediated migration observed in HUVEC and MDA-MB-231 cells, respectively, are likely to be important therapeutic targets in triple-negative breast cancer metastasis.

Gigacycle fatigue behavior by ultrasonic nanocrystalline surface modification

Nanocrystalline surface layer up to 84 microm in thick is produced on a specimen made of Al6061-T6 alloy by means of surface treatment called ultrasonic nanocrystalline surface modification (UNSM) technique. The refined grain size is produced in the top-layer and it is increased with increasing depth from the top surface. Vickers microhardness measurement for each nanocrystalline surface layer is performed and measurement results showed that the microhardness is increased from 116 HV up to 150 HV, respectively. In this study, fatigue behavior of Al6061-T6 alloy was studied up to 10(7)-10(9) cycles by using a newly developed ultrasonic fatigue testing (UFT) rig. The fatigue results of the UNSM-treated Al6061-T6 alloy specimens were compared with those of the untreated specimens. The microstructure of the untreated and UNSM-treated specimens was characterized by means of scanning electron microscopey (SEM) and transmission electron microscopey (TEM).

Nonstructural 5A protein of hepatitis C virus regulates heat shock protein 72 for its own propagation

We identified heat shock protein 72 (Hsp72) as a host factor that was differentially expressed in cells expressing nonstructural 5A (NS5A) protein. To investigate how NS5A modulates Hsp72 in hepatitis C virus (HCV) life cycle, we examined the role of Hsp72 in HCV replication and virus production. NS5A specifically interacted with Hsp72. Both Hsp72 and nuclear factor of activated T cells 5 (NFAT5) levels were increased in cells expressing NS5A protein. Treatments of N-acetylcysteine and glutathione markedly reduced protein levels of both NFAT5 and Hsp72. Knockdown of NFAT5 resulted in decrease in Hsp72 level in cells expressing NS5A. Importantly, silencing of Hsp72 expression resulted in decrease in both RNA replication and virus production in HCV-infected cells. These data indicate that NS5A modulates Hsp72 via NFAT5 and reactive oxygen species activation for HCV propagation.

Culture and in vitro hepatogenic differentiation of placenta-derived stem cells, using placental extract as an alternative to serum

OBJECTIVES

Translational research using adult stem cells derived from various tissues has been highlighted in cell-based therapy. However, there are many limitations to using conventional culture systems of adult stem cells for clinically applicability, including limited combinations of cytokines and use of nutrients derived from animals. Here, we have investigated the effects of placental extract (PE) for culture of placenta-derived stem cells (PDSCs) as well as their potential for hepatogenic differentiation.

MATERIALS AND METHODS

Placental extract, extracted using water-soluble methods, was used as a supplement for culture of PDSCs. Cell viability was determined using the MTT assay, and cytokine assay was performed using Luminex assay kit. Gene expression, indocyanine green (ICG) up-take, PAS (Periodic Acid-Schiff) staining and urea production were also analysed.

RESULTS

The placental extract contained several types of cytokine and chemokine essential for maintenance and differentiation of stem cells. Expression of stemness markers in PDSCs cultured with PE is no different from that of PDSCs cultured with foetal bovine serum (FBS). After hepatogenic differentiation, expression patterns for hepatocyte-specific markers in PDSCs cultured with PE were consistent and potential for hepatogenic differentiation of PDSCs cultured with PE was similar to that of PDSCs cultured with FBS, as shown by PAS staining and urea production assays.

CONCLUSIONS

Our findings revealed that placental extract could be used as a new component for culture of adult stem cells, as well as for development of human-based medium, in translational research for regenerative medicine.

Hyperhydricity in apple: ultrastructural and physiological aspects

We studied the effects of hyperhydricity on subcellular ultrastructure and physiology of leaves during in vitro regeneration of apple plants. Morphological, anatomical and ultrastructural differences between healthy leaf tissues obtained from greenhouse-grown plants and healthy and hyperhydric leaves obtained from shoots raised from nodal shoot explants in a bioreactor were investigated by electron microscopy and confocal laser scanning microscopy. Compared with healthy leaves, hyperhydric leaves showed abnormal, often discontinuous development of the epidermis and cuticle. Stomata were malformed. The leaf lamina appeared thickened and was characterized by poor differentiation between the palisade and spongy mesophyll tissue. Hyperhydric leaves had a significantly lower chloroplast number per cell and chloroplasts showed reduced thylakoid stacking compared with healthy leaves. Hyperhydricity resulted in a general decrease in concentrations of reduced and oxidized pyridine nucleotides, reflecting a reduction in metabolic activity. The activities of antioxidant enzymes, such as superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase were higher in hyperhydric leaves than in healthy leaves, indicating that hyperhydricity was associated with oxidative stress. Chlorophyll fluorescence measurements provided evidence of oxidative damage to the photosynthetic machinery in hyperhydric leaves: photochemical efficiency of photosystem II, effective quantum efficiency and photochemical quenching were all lower in hyperhydric leaves compared with healthy leaves.

An ex-vivo experimental study on optimization of bipolar radiofrequency liver ablation using perfusion-cooled electrodes

PURPOSE

To determine optimal parameters for bipolar radiofrequency ablation (RFA) using perfusion-cooled electrodes to create a large ablation volume in ex vivo bovine liver.

MATERIAL AND METHODS

Three sets of RF experiments were performed using a 200-Watt generator and two 15-gauge perfusion-cooled or internally cooled electrodes in ex vivo bovine livers. In the first set of experiments, to find the ideal inter-electrode distance for creating large coagulation necrosis, 30 ablation lesions were created by bipolar RFAs at inter-electrode spacings of 3 cm, 4 cm, and 5 cm. In the second set of experiments, to explore the ideal duration of RF application, bipolar RFAs were performed for 10 min and 20 min. In the first and second experiments, 10 lesions were made for each condition with infusion of 6% hypertonic saline (HS) at 2 ml/min. In the third set of experiments, 10 ablation lesions were created by bipolar RFAs using internally cooled electrodes without HS infusion. The mean volume of those ablation lesions was then compared to that of the lesions created by bipolar RFA using perfusion-cooled electrodes in the second experiments. Tissue impedance, dimension, and shape of the ablated areas were compared in each condition.

RESULTS

In the first set of experiments, bipolar RFA created a homogeneous oval or spherical-shaped ablation area between the electrodes at 3-5 cm spacing, but showed a more spherical-shaped lesion at 3 cm inter-electrode spacing than at 4 cm and 5 cm spacing. In the second set of experiments, RF energy delivered for 20 min created a larger dimension of coagulation necrosis than energy delivered for 10 min: 107.6 +/- 34 cm3 versus 59.5 +/- 27 cm3 (P<0.05). In addition, the mean volume of ablation regions obtained with bipolar RFA using the internally cooled electrode was 47.5+/- 17 cm3, which was significantly less than that with bipolar RFA using perfusion-cooled electrodes (P <0.05).

CONCLUSION

Bipolar RFA using perfusion-cooled electrodes achieves homogeneous areas of coagulation necrosis between two electrodes, preferably at 3 or 4 cm inter-electrode distance for 20 min, and is better in creating large coagulation necrosis than bipolar RFA using internally cooled electrodes.

Macrophage-stimulating activity of exo-biopolymer from cultured rice bran with Monascus pilosus

To find a new use of rice bran, five fungi were examined for the production of exo-biopolymer with macrophage-stimulating activity from rice bran. Among the exo-biopolymers produced from the cultures, Monascus pilosus had the most potent macrophage stimulating activity in a liquid culture rather than in a solid culture. In order to improve the yield of exo-biopolymer with macrophage-stimulating activity, a suitable medium for exo-biopolymer was tested in submerged culture of M. pilosus. The highest amount of exo-biopolymer (13.9 mg/mL) was obtained in a medium containing rice bran as an only carbon source followed by media with additional maltose and sucrose (13.8 and 13.7 mg/mL, respectively). The addition of peptone resulted in the production of high amount of exo-biopolymer (15.1 mg/mL), meanwhile the addition of ammonium chloride resulted in 264.0 microg/mL of glucosamine content. Among eight different kinds of inorganic salts tested, potassium phosphate (0.1%) was the most effective inorganic salt for the mycelial growth and exo-biopolymer production. Therefore the optimal medium composition was as follows (g/L): 20 g of rice bran, 5 g of peptone, and 1 g of KH2PO4. The optimal culture pH and time for mycelial growth and exo-biopolymer production was pH 5.0 and 25 degrees C, respectively. The maximum exo-biopolymer (20.1 mg/mL) was observed at the fourth day of cultivation. Exo-biopolymer, a crude polysaccharide fraction, mainly contained neutral sugar (81.8%) with considerable amounts of uronic acid (18.2%). Component sugar analysis showed that the active fraction consisted mainly of arabinose, galactose, glucose, which was digested from starch of rice bran during cultivation, and uronic acid (molar ratio; 0.8:1.0:0.7:0.8).

Alpha-difluoromethylornithine, ornithine decarboxylase inhibitor, antagonizes H2O2-induced cytotoxicity in HL-60 leukemia cells: regulation of iron-dependent lysosomal damage

Recent studies indicate that reactive oxygen species, such as H2O2, can be generated by anti-cancer drugs, can damage cells, and then induce apoptotic cell death. In this study, we reported whether polyamines were capable of affecting apoptotic cell death triggered by H2O2 in leukemia cells or not. Alpha-difluoromethylornithine treatment (DFMO, 3 mmol/L, 48 h), which depletes intracellular putrescine by inhibiting ornithine decarboxylase, reduced H2O2-induced cell death in the HL-60 leukemia cells. Cytotoxicity caused by H2O2 in putrescine-depleted cells was 50% lower than that in the control cells, as determined by propidium iodide, the annexin V and DNA fragmentation assays. Following putrescine (1 mmol/L) supplement, cell death induction caused by H2O2 was restored to a similar level as the DFMO-untreated control cells. It seems that this partly resulted from the intralysosomal iron-dependent oxidation of the cells because DFMO did not significantly affect the increment of enzymes related to oxidative-stress resistance. Putrescine depletion by DFMO treatment reduced the cellular iron uptake of the cells by about 70%. In parallel to the reduction of iron uptake, lysosomal damage (assayed by acridine orange relocalization or uptake test) in the DFMO-treated cells was far less than that in the control cells. Moreover, putrescine supplement also restored the iron uptake to the control cell levels. Pre-incubation with desferrioxamine (DFO), which chelates iron and forms a non-reactive Fe-DFO complex that is localized in the lysosomal compartment, inhibited H2O2-induced cell death. This work suggests that polyamines may play a critical role in apoptotic cell death triggered by H2O2 via the regulation of the iron-dependent instability of the lysosome.

Association of the oestrogen receptor alpha gene polymorphisms with disease onset in systemic lupus erythematosus

OBJECTIVE

To evaluate the genetic influence of PvuII and XbaI polymorphisms of oestrogen receptor alpha (ORalpha) in patients with systemic lupus erythematosus (SLE) in Korea.

METHODS

Genomic DNA from 268 female controls and 137 female SLE patients (41 childhood onset and 96 adult onset) were analysed using PvuII and XbaI restriction fragment length polymorphism. Comparison of the frequencies of alleles and genotypes was made in control and patient groups and in childhood onset and adult onset SLE subgroups.

RESULTS

Although the Pp genotype occurred more often in SLE patients than in controls (p(c) = 0.017), ORalpha genotype distributions of adult onset SLE did not differ significantly from controls. The PP, Pp, and xx genotypes occurred less often in childhood onset SLE (p(c) = 0.0045, 0.0498, and 0.0255, respectively) than in controls. Additionally, the PP genotype was less common in childhood onset than in adult onset SLE (p(c) = 0.016). SLE patients with the PP genotypes were older at disease onset than those with the other genotypes (p = 0.001). Patients with the Xx genotype had an earlier onset of SLE than those with the xx genotype (p = 0.025). The frequency of the combined ppXx genotype was greater in childhood onset SLE than in controls (p(c) = 0.0009) or adult onset SLE (p(c) = 0.027). The same trend was supported by subgroup analyses according to age at menarche and logistic multivariate analyses.

CONCLUSIONS

ORalpha polymorphisms are significantly associated with the age at disease onset in Koreans with SLE.

Phylogenetic relationships between the six superoxide dismutase proteins (FeSOD) of Trichomonas vaginalis and FeSOD6 genetic diversity

The parasitic protozoan Trichomonas vaginalis is known to contain several types of Fe-containing superoxide dismutase proteins (FeSOD). Using three different methods of phylogenetic analysis, maximum parsimony (MP), neighbor joining (NJ), and maximum likelihood (ML) methods, we examined the phylogenetic relationships among the six FeSOD (FeSOD1-FeSOD6) based on their amino acid sequences. All the analyses consistently suggested that the six proteins formed a monophyletic group implying that they probably be originated from an ancestral protein form through repeated duplication events. Although MP tree was totally unresolved, the NJ and ML trees revealed that FeSOD6 placed the most basal position and thus emerged earlier than the other five gene types during the evolution of T. vaginalis. Phylogenetic relationships among the five remaining proteins were (FeSOD2, FeSOD3), (FeSOD4, (FeSOD1, FeSOD5)) although weakly supported in terms of bootstrapping values. In addition to this, we newly designed two PCR primer specifically amplifying full-length FeSOD6 gene and examined its genetic diversity among 12 T. vaginalis isolates from five countries and three continents. They had the same nucleotide sequences except those of three Korean isolates which showed one to three different nucleotides.

Involvement of phospholipase D in oxidative stress-induced necrosis of vascular smooth muscle cells

Phospholipase D (PLD) has been associated with necrosis. However, it is not clear whether PLD plays a causative role in this cellular process. We investigated the role of PLD in oxidative stress-induced necrosis of vascular smooth muscle cells (VSMCs). Pervanadate (hydrogen peroxide plus orthovanadate) but not hydrogen peroxide alone activated PLD in a dose- and time-dependent manner. Exposure of VSMCs to pervanadate resulted in necrosis. Pretreatment with butan-1-ol, a PLD inhibitor, attenuated both pervanadate-induced necrosis and increase of intracellular Ca(2+). Removal of extracellular Ca(2+) inhibited pervanadate-induced necrosis by 50%. These results suggest that PLD activation mediates pervanadate-induced necrosis of VSMCs, which is at least partly due to Ca(2+) toxicity.

Candida thermophila sp. nov., a novel thermophilic yeast isolated from soil

Yeast strain Y94T, which is capable of growth at high temperature, was isolated from soil in Korea. Characteristics of the strain include asexual reproduction by multilateral budding, the absence of extracellular starch-like compounds, a negative Diazonium blue B colour reaction, and the absence of arthrospores, ballistoconidia and ascospores; the strain can therefore be placed in the genus Candida. A maximum growth temperature of 50-51 degrees C, along with certain other physiological characteristics, and a unique 26S rDNA partial sequence separate this strain from other ascomycetous yeasts. Taken together, these results suggest that the strain is a novel species and the name Candida thermophila sp. nov. (type strain is Y94T = JCM 10994T = KCCM 50661T) is proposed.

Effects of polysaccharides from rhizomes of Curcuma zedoaria on macrophage functions

The effects of Curcuma zedoaria, which is used as a condiment, in perfumery, and as a medicine, on immune response were investigated by measuring macrophage-stimulating activity in macrophages and RAW 264.7 cells. In this study, CZ-1 and CZ-1-III, the fractions partially purified from C. zedoaria, had a strong, dose-dependent lysosomal enzyme activity. It was suggested that active portions of CZ-1-III were polysaccharides rather than proteins. Phagocytic activity increased as a similar pattern in both the gram-negative and gram-positive bacteria, time-dependently. It was demonstrated that CZ-1-III can augment the oxygen burst response but had an even higher activity in vivo than in vitro. Also a significant increase of H2O2, NO, and TNF-alpha production was observed. However, the production of TNF-alpha at the concentration of 1,000 microg/ml decreased. These data suggested that C. zedoaria had macrophage-stimulating activity and the possibility of being used as a biological response modifier.

Blocker state dependence and trapping in hyperpolarization-activated cation channels: evidence for an intracellular activation gate

Hyperpolarization-activated cation currents (I(h)) are key determinants of repetitive electrical activity in heart and nerve cells. The bradycardic agent ZD7288 is a selective blocker of these currents. We studied the mechanism for ZD7288 blockade of cloned I(h) channels in excised inside-out patches. ZD7288 blockade of the mammalian mHCN1 channel appeared to require opening of the channel, but strong hyperpolarization disfavored blockade. The steepness of this voltage-dependent effect (an apparent valence of approximately 4) makes it unlikely to arise solely from a direct effect of voltage on blocker binding. Instead, it probably indicates a differential affinity of the blocker for different channel conformations. Similar properties were seen for ZD7288 blockade of the sea urchin homologue of I(h) channels (SPIH), but some of the blockade was irreversible. To explore the molecular basis for the difference in reversibility, we constructed chimeric channels from mHCN1 and SPIH and localized the structural determinant for the reversibility to three residues in the S6 region likely to line the pore. Using a triple point mutant in S6, we also revealed the trapping of ZD7288 by the closing of the channel. Overall, the observations led us to hypothesize that the residues responsible for ZD7288 block of I(h) channels are located in the pore lining, and are guarded by an intracellular activation gate of the channel.

Pretreatment of whole blood for use in immunochromatographic assays for hepatitis B virus surface antigen

Immunochromatographic assays (ICAs) are also referred to as rapid tests, since they are simple and the results can be obtained within minutes after manually loading a few drops of a sample into each sample well of the test device. However, whole blood cannot be tested with ICA kits due to the visual hindrance caused by the color of red blood cells (RBCs), unless a cell-removing device such as a filter is mounted on the kits. Thus, when testing with blood, the advantage of the ICA kit is lost because of the additional time and machines required to coagulate and separate whole blood before preparing the serum. To overcome this limitation, whole-blood samples were added to a pretreatment solution to decolor the RBCs; the resulting mixtures were then loaded into the sample wells of the test device. The pretreating solution was composed of hydrogen peroxide (H(2)O(2)) to decolor the RBCs, Sag 471 (Osi Specialties) to restrain the mixture from vigorous foaming, sodium azide (NaN(3)) to inhibit the enzyme, which generates excessive foam at the beginning of decolorization, and EDTA as a chelating agent. As a result of this pretreatment, whole blood could be used with the ICA kit without reducing its simplicity and rapidity.

Molecular identification of Paragonimus ohirai and P. westermani from Anhui Province, China

Nucleotide sequences of the internal transcribed spacer 2 (ITS2) region were determined from seven adults of species Paragonimus collected from Jinde and Xiuning Counties, Anhui Province, China. Among these, the nucleotide sequence obtained from one Paragonimus adult (Jinde County) was identical to the ITS2 sequence of P. ohirai previously reported. In order to confirm the result, partial regions of mitochondrial cytochrome C oxidase I (COI) and NADH dehydrogenase 1 (ND1) from the putative P. ohirai sample were further sequenced. They showed a high level of similarity with those of P. ohirai, COI (99.7%) and ND1 (99.5%), supporting the result obtained from the ITS2. In addition to this, we designed P. ohirai- and P. westermani-specific primers (BDW and BD2OH) from ITS2 to identify P. westermani and P. ohirai easily and rapidly. After testing utility of the primers, they were applied to identify seven unidentified Paragonimus samples collected from Jinde and Xiuning Counties, China. All the examined samples showed P. westermani band pattern, and it was reconfirmed by sequencing their ITS2 regions that they are P. westermani. This result indicates that the two newly designed specific primers could be quite helpful for easily identifying P. westermani and P. ohirai, that most of Paragonimus in Jinde and Xiuning Counties consist of P. westermani, and that P. ohirai exists in Jinde County with minority.

Purification and characterization of a new member of the laccase family from the white-rot basidiomycete Coriolus hirsutus

Laccase produced by Coriolus hirsutus was purified to electrophoretic homogeneity by acetone precipitation, DEAE Sepharose CL-6B, Sephacryl S-200 HR, Hitrap SP, and Mono S chromatography. The purification was 14.5-fold with an overall yield of 32.3%. The enzyme is a monomeric glycoprotein with 11% carbohydrate content, an isoelectric point of 7.4, and a molecular mass of 73 kDa. The N-terminal amino acid sequence showed low homology to those of the laccases of other white-rot basidiomycetes. Spectroscopic analyses revealed a typical laccase active site in the C. hirsutus enzyme, as all three Cu centers were identified. The absorption spectrum showed a type 1 signal at around 600 nm and a type 3 signal near 330 nm. Type 3 Cu showed fluorescence emission near 418 nm and an excitation maximum at 332 nm. The EPR spectrum yielded parameters for the type 1 and type 2 Cu of gII = 2.191 and AII = 0.0097 cm(-1), and gII = 2.222 and AII = 0.0198 cm(-1), respectively. The highest rate of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) oxidation for the enzyme was reached at 45 degrees C, and the pH optima of the enzyme varied and was substrate dependent in the range of 2.5 to 4.0. The enzyme oxidized a variety of the usual laccase substrates, including lignin-related phenols and had highest affinity toward guaiacol. Under standard assay conditions, the apparent Km value of the enzyme toward guaiacol was 10.9 microM. The enzyme catalyzed single electron transfer via the phenoxy radical as an intermediate and was completely inhibited by L-cysteine and sodium azide but not by EDTA.

Heterotopic pancreas in the stomach: CT findings

PURPOSE

To describe the computed tomographic (CT) findings of heterotopic pancreas in the stomach.

MATERIALS AND METHODS

CT findings in 12 patients with heterotopic pancreas in the stomach were reviewed. Surgical resection (n = 11) or endoscopic excision (n = 1) was performed in cases of symptomatic heterotopic pancreas (n = 4), suspected submucosal tumors (n = 7), and gastric carcinoma (n = 1). Seven patients underwent helical CT with water as an oral contrast agent; five underwent nonhelical CT with water-soluble contrast material.

RESULTS

Nine heterotopic pancreata were in the antrum and one each was in the body, fundus, and perigastric fat. Seven lesions were on the greater curvature aspect; five, on the lesser curvature aspect. Common CT findings were well-defined oval or round masses with smooth or serrated margins in the gastric antral wall. Four of the seven lesions in which helical CT was performed enhanced similarly to normal pancreas. Preoperatively, CT depicted 11 of the 12 lesions, but CT findings were interpreted correctly as heterotopic pancreas in only two; the remaining 10 were misinterpreted as other lesions. Atypical findings were cystic dilatation of heterotopic pancreatic duct in two, unusual location in the fundus or perigastric fat in two, and malignant transformation in one.

CONCLUSION

CT findings of heterotopic pancreas in the stomach appear to be nonspecific for diagnosis, except for location.

Up-regulation and co-expression of fibroblast growth factor receptors in human gastric cancer

Fibroblast growth factor (FGF), a key regulatory factor of cell growth and differentiation, is involved in embryonic development, angiogenesis, and tumorigenesis. To date, four different FGF receptors (FGFRs) have been cloned and characterized. We examined the expression of four FGFRs in human gastric cancer tissues and cell lines using Northern analysis, ribonuclease protection assay, and immunohistochemistry. The mRNAs of FGFR-1 (10/14), FGFR-2 (9/14), and FGFR-4 (9/14) were up-regulated in cancer compared with normal tissues. FGFR-3 mRNAs were barely detectable in both normal and cancer tissues. These FGFR mRNAs were co-expressed in various combinations of two or three in the same tissue. Immunohistochemistry confirmed specific staining of multiple FGFRs, except FGFR-3, in the cancer specimens. To investigate the functional significance of FGFR co-expression we examined the invasive property of SNU-16 cells, which exhibited gene amplification of FGFR-2, -3, and -4 as well as over-expression of keratinocyte growth factor receptor (KGFR), a splice variant of FGFR-2, and FGFR-4 mRNA. KGF plus acidic FGF (aFGF), KGF, and aFGF treatment enhanced the invasive potential of SNU-16 cells over the control by 100%, 107%, and 47%, respectively, indicating that neither additive nor synergistic effect was induced by stimulation with aFGF plus KGF. These results suggest that co-expression of FGFRs in various combinations may cause subtle changes in the progression of gastric cancer.

Surface-displayed viral antigens on Salmonella carrier vaccine

We have developed a recombinant live oral vaccine using the ice-nucleation protein (Inp) from Pseudomonas syringae to display viral antigens on the surface of Salmonella spp. Fusion proteins containing viral antigens were expressed in the oral vaccine strain, Salmonella typhi Ty21a. Surface localization was verified by immunoblotting and fluorescence-activated cell sorting. The immunogenicity of surface-displayed viral antigens on the recombinant live vaccine strain was assessed in mice inoculated intranasally and intraperitoneally. Inoculation resulted in significantly higher serum antibody level than those induced by viral antigens expressed intracellularly. Thus, this multivalent mucosal live vaccine may provide an effective means for inducing mucosal or systemic immune responses against multiple viral antigens.

Ultrasonic surgical aspiration with endoscopic confirmation for osmidrosis

Ultrasonic surgical aspiration of axillary apocrine glands with endoscopic confirmation was used for treating osmidrosis in 87 patients. Ultrasound energy liquefies fat and sweat glands via cavitation, but minimally affects blood vessels and nerves at the same energy level. We hypothesised that since the apocrine glands were located within the subcutaneous fat layer, ultrasound liposuction would be effective in its removal and also preserve vasculature of the axillary skin for optimal wound healing. The endoscope was used to visually confirm adequate removal of fat and sweat glands. Our method was effective in 84 patients (96.5%) and recurrence of odour occurred in three patients (3.5%). There were no cases of haematoma, seroma, or skin necrosis. Our method leaves a small inconspicuous scar, maintains normal axillary hair pattern and avoids contracture of the axillary skin after a short and comfortable recovery period.

Skin flap prefabrication using acellular dermal matrix and cultured keratinocytes in a porcine model

In an effort to minimize the amount of autogenous tissue that is sacrificed in using a random skin flap, the authors, in a porcine model, implanted 3.0 x 7.0-cm (median thickness, 1 mm) sheets of commercially available nonmeshed acellular dermal matrix (AlloDerm) subcutaneously. After a vascularization period of 2 weeks, the implants were elevated and used as turnover dermal flaps to cover adjacent 3.0 x 3.0-cm full-thickness skin defects. Sheets of autogenous cultured keratinocytes were used for epithelium. The AlloDerm-cultured keratinocyte complex flaps healed without any complications. Measurements for percent contraction of the wound to determine the suitability of AlloDerm as a dermal flap showed that the wounds had contracted an average of 18 +/- 3.6% at 24 weeks. Histological evaluation revealed multilayered keratinocytes and indurations between the cultured keratinocytes and AlloDerm. Fibroblast infiltration and the presence of luminal spaces surrounded by capillary endothelium characteristic of neovascularization of the matrix were also noted. This preliminary study may form the basis for developing other types of prefabricated flaps using AlloDerm and cultured keratinocytes.

Human granulocytic ehrlichiosis agent infection in a pony vaccinated with a Borrelia burgdorferi recombinant OspA vaccine and challenged by exposure to naturally infected ticks

A pony was vaccinated with recombinant OspA vaccine (rOspA) and then exposed 3 months later to Borrelia burgdorferi-infected ticks (Ixodes scapularis) collected in Westchester County, N.Y. At 2 weeks after tick exposure, the pony developed a high fever (105 degrees F). Buffy coat smears showed that 20% of neutrophils contained ehrlichial inclusion bodies (morulae). Flunixin Meglumine (1 g daily) was given for 2 days, and the body temperature returned to normal. PCR for ehrlichial DNA was performed on blood samples for 10 consecutive days beginning when the pony was first febrile. This pony was monitored for another 3.5 months but developed no further clinical signs. The 44-kDa immunodominant human granulocytic ehrlichiosis antigen gene was amplified by PCR and cloned into a pCR2.1 vector. DNA sequence analysis of this gene showed it was only 8 bp different (99% identity) from the results reported by others (J. W. Ijdo et al., Infect. Immun. 66:3264-3269, 1998). Western blot analysis, growth inhibition assays, and repeated attempts to isolate B. burgdorferi all demonstrated the pony was protected against B. burgdorferi infection. These results highlight the potential for ticks to harbor and transmit several pathogens simultaneously, which further complicates the diagnosis and vaccination of these emerging tick-borne diseases.

Role of hyperpolarization attained by linoleic acid in chick myoblast fusion

Our previous report has suggested that hyperpolarization generated by reciprocal activation of calcium-activated potassium (K(Ca)) channels and stretch-activated channels induces calcium influx that triggers myoblast fusion. Here we show that linoleic acid is involved in the process of generating hyperpolarization in cultured chick myoblasts and hence in promotion of the cell fusion. Linoleic acid dramatically hyperpolarized the membrane potential from -14 +/- 3 to -58 +/- 5 mV within 10 min. This effect was partially blocked by 1 mM tetraethylammonium (TEA) or 30 nM charybdotoxin, a selective K(Ca) channel inhibitor, and completely abolished by 10 mM TEA. Single-channel recordings revealed that linoleic acid activates TEA-resistant potassium channels as well as K(Ca) channels. Furthermore, linoleic acid induced calcium influx from extracellular solution, and this effect was partially blocked by 1 mM TEA and completely prevented at 10 mM, similar to the effect of TEA on linoleic acid-mediated hyperpolarization. Since the valinomycin-mediated hyperpolarization promoted calcium influx, hyperpolarization itself appears capable of inducing calcium influx. In addition, gadolinium prevented the valinomycin-mediated increase in intracellular calcium level under hypotonic conditions, revealing the involvement of stretch-activated channels in calcium influx. Furthermore, linoleic acid stimulated myoblast fusion, and this stimulatory effect could completely be prevented by 10 mM TEA. These results suggest that linoleic acid induces hyperpolarization of membrane potential by activation of potassium channels, which induces calcium influx through stretch-activated channels, and thereby triggers myoblast fusion.

An unusual case of colonic duplication causing chronic constipation in a child

A case of colonic duplication producing chronic constipation in a 8-year-old boy is presented. Barium enema studies demonstrated a long tubular shape of duplication that branched out from the lower part of descending colon. Successful surgical treatment was achieved by excision of the duplication with a portion of adjacent bowel and an end-to-end anastomosis.

Down-regulation of phospholipase D during differentiation of mouse F9 teratocarcinoma cells

Phospholipase D has been recognized as playing an important role in signal transduction in many types of cells. We investigated the expression of phospholipase D during the differentiation of F9 embryonal teratocarcinoma cells. The ADP ribosylation factor-dependent phospholipase D activity, as measured by an in vitro assay, and H2O2-induced phospholipase D activity and phospholipase D protein content in whole cells were decreased during the differentiation of F9 cells induced by a combination of dibutyryl cyclic AMP and all-trans retinoic acid. In contrast, these changes were not observed when cells were induced by retinoic acid. These results suggest that down-regulation of phospholipase D protein is associated with differentiation of F9 cells to a parietal endoderm lineage.

Expression of SET is modulated as a function of cell proliferation

We explored a biological role of SET as it relates to cell proliferation and differentiation. Immunohistochemical staining demonstrated that the expression of SET was ubiquitous and diffuse over the whole embryo on gestational day 15. At a later stage of development, SET was expressed at relatively lower levels and localized to specific tissues and cells. On embryonic day 19, specific SET immunoreactivity was found in the epithelium of skin, respiratory tract, intestine, and retina as well as in muscle and cartilage. In these cells SET was stained mostly in the nucleus, which was supported indirectly by nuclear transport of enhanced green fluorescence protein-SET fusion proteins in ECV304 endothelial cells. Set mRNA expression was further confirmed in various cultured cells, including NIH 3T3 cells, L6 myoblast cells, human umbilical vein endothelial cells, and ECV304 cells. Using F9 teratocarcinoma cell lines, which were stimulated to differentiate into the two different cell lineages of parietal and visceral endoderm, we have further examined the role of SET. The expression of set mRNA and SET protein was diminished about three-fold in both differentiated endoderm cells compared to the undifferentiated F9 cells. However, when F9 cells were subjected to serum starvation, reduction of set mRNA abundance also took place at a similar level to that observed in response to differentiation. Consistent with this, quiescent L6 myoblast showed a marked downregulation of set mRNA compared to proliferating cells. These results suggest that SET is involved mainly in the regulation of cell proliferation rather than differentiation during embryonic development.

Drug-resistant pulmonary tuberculosis in a tertiary referral hospital in Korea

OBJECTIVES

To estimate the resistance rate and to correlate the clinical characteristics of resistant tuberculosis with the patients of pulmonary tuberculosis who were referred to the university hospital.

METHODS

We prospectively performed sensitivity tests for all patients who were diagnosed as active tuberculosis by sputum smear or sputum culture from January, 1995 to June, 1996. Patients profile, previous treatment history, patterns of drug resistance, initial chest films and other clinical findings were analysed.

RESULTS

Overall, 24(26.0%) of the 92 patients had resistance to at least one drug and 8(8.6%) had resistance to isoniazid(INH) and rifampin(RFP). Among the 66 patients without previous tuberculosis therapy, 11(16.6%) were drug-resistant and 2(3.0%) were multi-drug resistant. Among the 26 patients with previous therapy, 13(50.0%) were drug-resistant and 6(23.0%) were multi-drug resistant. For all 92, resistance to INH was most common (19.5%), followed by RFP (9.7%) and ethambutol (9.7%). Drug resistance was significantly high in previously treated patients and in cavity-positive patients. Treatment failure was also high in previously treated patients with resistant tuberculosis. In patients with primary resistance, treatment failure was not observed.

CONCLUSION

Sensitivity tests are strongly recommended in all culture positive patients with previous therapy but, in patients with primary resistance, sensitivity tests are not required. Proper combination chemotherapy should be given under careful surveillance.

The activation gate of a voltage-gated K+ channel can be trapped in the open state by an intersubunit metal bridge

Voltage-activated K+ channels are integral membrane proteins containing a potassium-selective transmembrane pore gated by changes in the membrane potential. This activation gating (opening) occurs in milliseconds and involves a gate at the cytoplasmic side of the pore. We found that substituting cysteine at a particular position in the last transmembrane region (S6) of the homotetrameric Shaker K+ channel creates metal binding sites at which Cd2+ ions can bind with high affinity. The bound Cd2+ ions form a bridge between the introduced cysteine in one channel subunit and a native histidine in another subunit, and the bridge traps the gate in the open state. These results suggest that gating involves a rearrangement of the intersubunit contacts at the intracellular end of S6. The recently solved structure of a bacterial K+ channel shows that the S6 homologs cross in a bundle, leaving an aperture at the bundle crossing. In the context of this structure, the metal ions form a bridge between a cysteine above the bundle crossing and a histidine below the bundle crossing in a neighboring subunit. Our results suggest that gating occurs at the bundle crossing, possibly through a change in the conformation of the bundle itself.

Paenibacillus campinasensis sp. nov., a cyclodextrin-producing bacterium isolated in Brazil

An alkaliphilic, endospore-forming bacterium isolated from Brazilian soil was taxonomically studied and is proposed as a new Paenibacillus species. This organism (strain 324T) was particularly distinguishable from other Paenibacillus species by its ability to grow optimally at pH 10 and 40 degrees C. The DNA G+C content was 5.0 mol%. The diamine acid of the cell-wall peptidoglycan was meso-diaminopimelic acid. MK-7 was the predominant menaquinone and anteiso-C15:0 was the major fatty acid. Levels of 16S rDNA similarity between strain 324T and other Paenibacillus species were 90.6-95.9%. Phylogenetically, strain 324T formed an evolutionary lineage distinct from other species within the evolutionary radiation encompassing the genus Paenibacillus. Based on phenotyic and chemotaxonomic properties, and phylogenetic inference, it is proposed that strain 324T should be placed in the genus Paenibacillus as a new species is strain 324T should be placed in the genus Paenibacilus as a new species, Paenibacillus campinasensis. This type strain of the new species is strain 325T (= KCTC 0364BP).

Pulp reconstruction of fingers with very small sensate medial plantar free flap

The essence in dealing with the pulp deficit accompanying fingertip injuries lies in functional restitution of the inherent skin texture and characteristics unique to that area and sufficient preservation of digital length, along with successful restoration of fine tactile sensation indispensable to delicate and skillful maneuvers. Among various techniques used to meet such demands, the very small sensate medial plantar free flap can be considered an excellent method in view of the skin texture that allows firm grasping, durability to friction rub, a cushion effect, and adequate sensation. Six cases of finger pulp reconstruction with the very small sensate medial plantar free flap are presented. At follow-up examination (an average follow-up of 24.3 months), the patients were evaluated clinically and neurologically. The operative procedures, advantages, and results in clinical cases are presented. Satisfactory results were obtained with sufficient preservation of digital length and good sensory recovery. No functional deficit was found at the donor site.

Opposite effect of intracellular Ca2+ and protein kinase C on the expression of inwardly rectifying K+ channel 1 in mouse skeletal muscle

The level of inwardly rectifying K+ channel 1 (IRK1) mRNA decreased upon denervation and increased during muscle differentiation in mouse skeletal muscle. To identify the mechanism(s) underlying the regulation of IRK1 mRNA expression, we examined its expression using the well differentiated C2C12 mouse skeletal muscle cell line as a model system. Since nerve-induced muscle activity results in contraction, it was questioned whether the changes in IRK1 expression might be relevant to the increased intracellular calcium that functions as a cytoplasmic messenger in excitation-contraction coupling. Indeed, activation of either L-type calcium channels or ryanodine receptors increased the level of IRK1 mRNA. More directly, ionomycin activated the IRK1 expression in time- and dose-dependent manners, which was abolished by treatment with EGTA. Genistein, a tyrosine kinase inhibitor, also abolished the stimulating effect of ionomycin. Meanwhile, activation of protein kinase C by 12-O-tetradecanoylphorbol acetate (TPA) markedly decreased the level of IRK1 mRNA, which required ongoing protein synthesis. Actinomycin D experiments revealed that ionomycin increased the half-life of IRK1 mRNA from 0.86 to 1.97 h, but TPA decreased it to 0.38 h. However, neither ionomycin nor TPA appreciably altered the rate of IRK1 gene transcription. Based on these observations, we conclude that intracellular calcium and protein kinase C are oppositely involved in the muscle activity-dependent regulation of IRK1 gene expression and that both act at the level of mRNA stability.

Unilateral multilayered musculocutaneous V-Y advancement flap for the treatment of pressure sore

We have devised a modified technique using the gluteus maximus musculocutaneous flap as multilayered sliding V-Y advancement to cover pressure sores on the sacral area. Nine patients with relatively large (average 7 x 7 cm) sacral grade IV pressure sores underwent unilateral multilayered V-Y advancement flap. All patients were followed for a minimum of 8 weeks. The mean postoperative follow-up was 32.3 months, with a range of 24 to 39 months. Using this technique, the success of surgery, i.e., the percentage of sores that healed, was 100 percent in our patients. The advantages of this technique include sufficient advancement of the flap, coverage of large ulcer defects using only a unilateral musculocutaneous flap, and preservation of the contralateral gluteus maximus muscle for future use.

Rhamnogalacturonan II from the leaves of Panax ginseng C.A. Meyer as a macrophage Fc receptor expression-enhancing polysaccharide

A complex pectic polysaccharide (GL-4IIb2) has been isolated from the leaves of Panax ginseng C.A. Meyer, and shown to be a macrophage Fc receptor expression-enhancing polysaccharide. The primary structure of GL-4IIb2 was elucidated by composition. 1H NMR, methylation, and oligosaccharide analyses. GL-4IIb2 consisted of 15 different monosaccharides which included rarely observed sugars, such as 2-O-methylfucose, 2-O-methylxylose, apiose, 3-C-carboxy-5-deoxy-L-xylose (aceric acid, AceA), 3-deoxy-D-manno-2-octulosonic acid (Kdo), and 3-deoxy-D-lyxo-2-heptulosaric acid (Dha). Methylation analysis indicated that GL-4IIb2 comprised 34 different glycosyl linkages, such as 3,4-linked Fuc, 3- and 2,3,4-linked Rha, and 2-linked GlcA, which are characteristic of rhamnogalacturonan II (RG-II). Sequential degradation using partial acid hydrolysis indicated that GL-4IIb2 contained alpha-Rhap-(1-->5)-Kdo and Araf-(1-->5) Dha structural elements, an AceA-containing oligosaccharide, and uronic acid-rich oligosaccharide chains in addition to an alpha-(1 -->4)-galacturono-oligosaccharide chain. FABMS and methylation analyses suggested that the AceA-containing oligosaccharide was a nonasaccharide in which terminal Rha was additionally attached to position 3 of 2-linked Arap of the octasaccharide chain observed in sycamore RG-II. Component sugar and methylation analyses assumed that the uronic acid-rich oligosaccharides possessed a similar structural feature as those in sycamore RG-II. GL-4IIb2 had a larger molecular mass (11,000) than sycamore RG-II (approximately 5000).

A possible role of inwardly rectifying K+ channels in chick myoblast differentiation

We examined the developmental change of inwardly rectifying K+ channels (IRK) and its possible role in myogenesis. Northern blot analysis revealed an increase in the level of IRK mRNA during myogenesis. Accordingly, IRK current was not detectable in replicating myoblasts but first appeared in aligned myoblasts that were competent for fusion and gradually increased thereafter. The time course change of IRK activity was closely related to the increase in resting membrane potential during myogenesis. Application of 0.5 mM Ba2+ to the bath depolarized the membrane and blocked IRK currents dramatically but not outwardly rectifying K+ currents. Myoblasts devoid of IRK had low resting K+ permeability, whereas myotubes that possess IRK had high resting K+ permeability. In some aligned myoblasts, anomalous hyperpolarization was elicited by increasing extracellular K+ concentration, which may be attributable to the increased conductance of IRK. Noteworthy was the fact that maximal fusion was obtained at this range of K+ concentration. These findings imply that IRK is responsible for the change in the K+ permeability during chick myogenesis, which may provide a larger driving force for Ca2+ influx that is a prerequisite for myoblast fusion.

Involvement of K(Ca) channels and stretch-activated channels in calcium influx, triggering membrane fusion of chick embryonic myoblasts

Calcium influx is known to be prerequisite for membrane fusion of myoblasts. However, little is known about the channels that are responsible for the entry of calcium into the cells. Here we show that K(Ca) channels and stretch-activated channels are involved in the calcium influx. Upon analysis of single-channel recordings, calcium sensitivity of K(Ca) channels in myoblasts was found to be about sixfold higher than that in myotubes. Their density in myoblasts (1.68 micron(-2)) was also about sixfold higher than that in myotubes (0.27 micron(-2)). In addition, the opening of the calcium-permeable cationic channels in myoblasts was found to increase with membrane stretching and could be blocked by gadolinium. The density of stretch-activated channels was 0.22 micron(-2) for myoblasts, and the relative permeability of calcium to potassium was P(Ca)/P(K) approximately 3.6. The channels could generate inward calcium currents to open K(Ca) channels in physiological solution. Furthermore, the activation of K(Ca) channels by phloretin dramatically hyperpolarized the resting membrane potential of myoblasts and this effect could be reversed upon treatment of tetraethylammonium. While phloretin induced precocious fusion, tetraethylammonium or gadolinium blocked not only the phloretin-induced precocious fusion but also the spontaneous fusion of myoblasts. These results suggest that hyperpolarization generated by reciprocal activation of stretch-activated channels and K(Ca) channels is involved in the calcium influx that triggers myoblast fusion.

Rhomboid design for tubed inguinal flap in fingertip reconstruction

The authors present a rhomboid design for the tubed inguinal flap mainly nourished by the superficial circumflex iliac vessels and the superficial inferior epigastric vessels. The length and width of the flap are mathematically determined based on the perimeter and length of the fingertip soft-tissue defect, respectively. The rhomboid tubed inguinal flap was used in the treatment of 21 patients with a variety of fingertip injuries. The thumb was involved in 12 patients and other digits in 9 patients. A complication, flap necrosis, occurred in one obese female patient and osteomyelitis of an amputated phalangeal bone developed in another. In all other patients, the rhomboid tubed inguinal flap healed uneventfully and provided satisfying results with minimal donor site morbidity. As a secondary procedure in thumb injuries, four neurovascular island flaps and one wrap around flap from the great toe were done for improved sensation. The precisely tailored rhomboid flap, with a safe and abundant vascular pedicle, allows for effective reconstruction of the fingertip with easy primary closure and minimal morbidity of the donor site.

Mode of action and active site of an extracellular peroxidase from Pleurotus ostreatus

The properties of the haem environment of an extracellular peroxidase from Pleurotus ostreatus were studied by electronic absorption spectroscopy. A high-spin ferric form was predominant in the native enzyme and a high-spin ferrous form in the reduced enzyme. Cyanide was readily bound to the haem iron in the native form, thereby changing the enzyme to a low-spin cyano adduct. The electronic absorption spectra of the enzyme were similar to those of lignin peroxidase from Phanerochaete chrysosporium. Compound III of the enzyme was formed after the addition of an excess of H2O2 to the native enzyme, and thereafter spontaneously reverted to the native form. The enzyme oxidized 1-(3,5-dimethoxy-4-hydroxyphenyl)-2-(2-methoxyphenoxy)-1,3-dihydroxyp ropane in the presence of H2O2 to produce 1-(3,5-dimethoxy-4-hydroxyphenyl)-2-(2-methoxyphenoxy)-1-oxo-3-hydroxypr opane , 2,6-dimethoxyhydroquinone, 2-(2-methoxyphenoxy)-3-hydroxypropanal, 2-(2-methoxyphenoxy)-3-hydroxypropanoic acid, 2,6-dimethoxy-1,4-benzoquinone and guaiacol. A similar oxidation pattern was demonstrated with a one-electron oxidant, ammonium cerium(IV)nitrate. Free radicals were detected as intermediates of the enzyme-mediated oxidation of 1-(3,5-dimethoxy-5-hydroxyphenyl)-2-(2-methoxyphenoxy)-1,3-dihydroxyp ropane and acetosyringone. These results can be explained by the mechanisms involving an initial one-electron oxidation of the lignin substructure. This radical may undergo C alpha-C beta cleavage, C alpha-oxidation and alkyl-phenyl cleavage.

Reduction mammaplasty by central pedicle flap with short submammary scar

Reduction mammaplasty was performed in 30 patients by combining the central pedicle flap method with the short submammary scar (3-S) technique to avoid the common drawbacks of currently popular dermoglandular procedures. Reduction was accomplished by using perforating vascular branches from the pectoralis major muscle and its fascia supplying the nipple and breast parenchyme instead of the subdermal plexus. The central vascular pedicle supplying the nipple-areola complex was preserved. Only the periphery of the breast parenchyme was resected circumferentially, with the exception of the inferolateral portion, so as not to injure the sensory nerve. The remaining breast parenchyme was preserved in an inverted cone shape. The nipple-areola complex was safely transposed with great freedom, and the amount of resection was accurately adjusted for symmetry. No cases of nipple-areola complex sensory change occurred postoperatively, and lactation is possible because of preservation of the lactiferous ducts. The length of postoperative scars was reduced by using the short submammary scar technique. We believe this combined method is ideal in patients requiring resections ranging from 200 to 600 g per breast with good skin elasticity and moderate degree of ptosis.

Involvement of transglutaminase in myofibril assembly of chick embryonic myoblasts in culture

Involvement of transglutaminase in myofibrillogenesis of chick embryonic myoblasts has been investigated in vitro. Both the activity and protein level of transglutaminase initially decreased to a minimal level at the time of burst of myoblast fusion but gradually increased thereafter. The localization of transglutaminase underwent a dramatic change from the whole cytoplasm in a diffuse pattern to the cross-striated sarcomeric A band, being strictly colocalized with the myosin thick filaments. For a brief period prior to the appearance of cross-striation, transglutaminase was localized in nonstriated filamental structures that coincided with the stress fiber-like structures. When 12-o-tetradecanoyl phorbol acetate was added to muscle cell cultures to induce the sequential disassembly of thin and thick filaments, transglutaminase was strictly colocalized with the myosin thick filaments even in the myosacs, of which most of the thin filaments were disrupted. Moreover, monodansylcadaverine, a competitive inhibitor of transglutaminase, reversibly inhibited the myofibril maturation. In addition, myosin heavy chain behaved as one of the potential intracellular substrates for transglutaminase. The cross-linked myosin complex constituted approximately 5% of the total Triton X-100-insoluble pool of myosin molecules in developing muscle cells, and its level was reduced to below 1% upon treatment with monodansylcadaverine. These results suggest that transglutaminase plays a crucial role in myofibrillogenesis of developing chick skeletal muscle.

Genotype distribution and comparison of the putative envelope region of hepatitis C virus from Korean patients

Comparative nucleotide sequence studies of the genomes of hepatitis C virus (HCV) revealed that there are at least 6 different genotypes of HCV. The prevalence of HCV genotypes among the patients with liver diseases in Korea was investigated using the polymerase chain reaction (PCR) for the NS5 region. In the 75 HCV RNA positive samples, two genotypes, type 1b and type 2a, were the major causative agents which accounted for 60% and 33% of infections respectively, while 7% could not be assigned a genotype by the methods used. The nucleotide sequences of cDNAs encoding the putative envelope proteins from 10 type 1b and 5 type 2a genotype samples were analyzed. Approximately 31-42% of the nucleotide sequences of type 1b samples examined differed from those of different genotypes. In the case of type 2a samples, 36-42% of the nucleotide sequences differed from those of different genotypes. The diversities of the amino acid sequences were the same or greater than those of the nucleotide sequences. Two hypervariable regions (HVR1 and HVR2) were recognized in both HCV genomes of genotypes 1b and 2a. However, the sequence divergence within the HVR2 region of genotype 2a was less than that of genotype 1b.

An improved burying method for salvaging an amputated auricular cartilage

An improved burying method for salvaging an amputated auricle is presented. We elevated a mastoid skin flap and a fascial flap simultaneously and inserted the denuded auricular cartilage between them. This procedure can maintain the auricular cartilage in a more natural form by eliminating undue skin tension and can give a favorable aesthetic result.

Columella lengthening in nasal tip plasty of Orientals

To elevate the nasal tip in Orientals, two simple adjunctive procedures are presented. Either V-Y advancement or earlobe composite graft can be used after the open rhinoplasty incision on the columella-labial junction. Over the past 6 years, 62 Oriental patients with short columella were treated with one of the above procedures. The nasal tip projection as well as nasal tip appearance greatly improved. The scar in the columellar base posed no problems, and none of the patients complained about the scar. The procedures are particularly useful for cosmetic rhinoplasty in Orientals as well as in cleft lip nasal deformity.

A candidate molecule for the matrix assembly receptor to the N-terminal 29-kDa fragment of fibronectin in chick myoblasts

Myoblast surface proteins with binding activity toward the N-terminal 29-kDa fragment of fibronectin were identified by two different experimental techniques: one involves radioiodination of the cell surface proteins, followed by solubilization with Triton X-100 and affinity purification on a Sepharose column conjugated with the 29-kDa fragment, and the other involves cross-linking of the 29-kDa fragment to the cells metabolically labeled with [35S]methionine, followed by immunoprecipitation with anti-29-kDa IgG. Both approaches revealed that primary cultures of chick myoblasts contain the 66- and 48-kDa proteins that bind to the 29-kDa fragment. These binding proteins were then purified to apparent homogeneity by two successive chromatographies of the solubilized extracts of 12-day-old embryonic muscle on wheat germ agglutinin-agarose and 29-kDa fragment-Sepharose columns. However, the 48-kDa protein was found to be derived from contaminating fibroblasts upon immunoblot analysis of the myogenic cell lines, rat L8E63 and mouse C2A3, and cultured fibroblasts using the antibody raised against the 66-kDa protein. Anti-66-kDa IgG inhibited the binding of the 125I-29-kDa protein to the primary culture of myoblasts in a dose-dependent manner. On the other hand, the same antibody showed little or no effect on the initial binding of 125I-fibronectin to the cell surface, but dramatically inhibited its incorporation into deoxycholate-insoluble matrices. Furthermore, Fab fragments of anti-66-kDa IgG completely blocked the incorporation of fluoresceinated fibronectin into matrices but not its binding to the cell surface. These results suggest that fibronectin matrix assembly is mediated at least in part by the interaction of the 66-kDa protein with the N-terminal type I domain of fibronectin.

Purification and characterisation of D-glucose oxidase from white-rot fungus Pleurotus ostreatus

D-Glucose oxidase was purified 27.5-fold to apparent homogeneity with an overall yield of 23.8%, from Pleurotus ostreatus, through a purification procedure of ammonium sulphate precipitation, gel-permeation, anion-exchange and hydrophobic-interaction chromatography. The molecular mass determined by gel filtration was found to be 290 kDa. SDS/PAGE revealed that the enzyme consists of four subunits with a molecular mass of 70 kDa. The absorption spectra of the enzyme exhibit maxima at 280, 360 and 460 nm. The enzyme shows a fluorescence spectrum with an excitation maximum at 470 nm and an emission maximum at 530 nm. These results indicate that the prosthetic group of the enzyme is flavin and that the enzyme contains 4 mol flavin/mol enzyme. The enzyme is optimally active at 50 degrees C and at pH 5.5-6.0. It exhibits broad affinity for various sugars and specificity for D-glucose with Km value of 1.34 mM. 2,6-Dichloroindophenol, Wurster's blue, and 4-benzoquinone can function as electron acceptors but phenazine methosulphate cannot function as an electron acceptor. The enzyme is inhibited completely by mercuric chloride and partially by silver sulphate, sodium azide 8-hydroxyquinoline.