Chemically doped double-walled carbon nanotubes: cylindrical molecular capacitors

A double-walled carbon nanotube is used to study the radial charge distribution on the positive inner electrode of a cylindrical molecular capacitor. The outer electrode is a shell of bromine anions. Resonant Raman scattering from phonons on each carbon shell reveals the radial charge distribution. A self-consistent tight-binding model confirms the observed molecular Faraday cage effect, i.e., most of the charge resides on the outer wall, even when this wall was originally semiconducting and the inner wall was metallic.

Direct imaging of Sc2@C84 molecules encapsulated inside single-wall carbon nanotubes by high resolution electron microscopy with atomic sensitivity

Intramolecular structure of the scandium dimetallofullerene (Sc(2)@C(84)) has been clearly revealed by high resolution transmission electron microscopy with the single-atom sensitivity. Direct observation of two Sc atoms inside each fullerene molecule has led to a successful determination of the molecular symmetry among the three possible structural isomers for the Sc(2)@C(84). The present work introduces a new electron microscopic approach to investigate individual molecular structures and demonstrates the possibility for determining the molecular isomer on a single-molecular basis.

Linking chiral indices and transport properties of double-walled carbon nanotubes

We performed in situ transport measurements in a transmission-electron microscope (TEM) on individual double-walled carbon nanotubes (DWNT). Using selected-area electron diffraction, the chiral indices of the two tubes constituting the DWNTs were determined through careful comparison with theory. We discuss the case of a DWNT whose two tubes have a gap at half filling and show a finite density of delocalized state at the Fermi level. The exact determination of chiral indices should be reachable in any transport-measurement experiment with samples that allow TEM characterization.

Distribution and partial characterisation of IgG Fc binding protein in various mucin producing cells and body fluids

BACKGROUND AND AIMS

Mucus released from goblet cells is important in intestinal mucosal defence, and mucin glycoproteins are thought to be major components of mucus. Recently, we identified and cloned another component of human colonic mucus, IgG Fc binding protein (Fc gamma BP). Fc gamma BP is immunologically distinct from known Fc gamma receptors and its structure contains repeated cysteine rich unit sequences resembling those present in mucins. In this work, we assessed the tissue distribution of Fc gamma BP, its binding activity in various body fluids, and its ability to inhibit complement mediated haemolysis.

METHODS

Immunohistochemical localisation of Fc gamma BP, using monoclonal antibodies against Fc gamma BP (K9 or K17) and labelled IgG, was conducted in various mucin producing tissues: colon, small intestine, stomach, gall bladder, cystic duct, choledochus, bronchus, submandibular gland, conjunctiva, and cervix uteri. The binding activity of Fc gamma BP in mucus extracted from colon, gastric juice, bile, nasal discharges, saliva, sputum, and tears was also examined by immunodotblot and immunoprecipitation using these monoclonal antibodies. Inhibition of complement mediated haemolysis by Fc gamma BP was investigated using sheep red blood cells (SRBC) and anti-SRBC IgG.

RESULTS

The immunohistochemical study revealed that mucin secreting cells in the colon, small intestine, gall bladder, cystic duct, choledochus, bronchus, submandibular gland, and cervix uteri contained Fc gamma BP, and immunodotblot and immunoprecipitation analysis using IgG and monoclonal antibodies demonstrated that the fluids secreted by these cells were capable of binding IgG. Mucin producing cells of the conjunctiva did not express Fc gamma BP molecules or bind to IgG. The surface mucus cells in the stomach were variably positive for Fc gamma BP. Perhaps because of proteolytic degradation, Fc gamma BP in gut lavage fluid did not have IgG binding activity, although this activity was present in the mucus covering the colon. Fc gamma BP suppressed complement mediated haemolysis of SRBC.

CONCLUSIONS

Fc gamma BP is widely expressed on mucosal surfaces and in external secretions. It is functionally intact in several fluids. These findings lend support to the concept that Fc gamma BP is an important component of mucosal immunological defences.

Chemoradiotherapy followed by surgery for thoracic esophageal cancer potentially or actually involving adjacent organs

The objective of this study was to evaluate the therapeutic usefulness of chemoradiotherapy (CRT) followed by surgery in patients with clinically T4 (cT4) esophageal cancer involving adjacent organs such as the trachea, main bronchi, and large vessels. Thirty-seven patients with cT4 squamous cell carcinoma of the thoracic esophagus were enrolled in this study. The CRT regimen comprised cisplatin (70 mg/m2) on day 1, 5-fluorouracil (700 mg/m2) on days 1-4 and external irradiation (200 cGy/day, total 30 Gy) on either days 8-26 (sequential schedule, n=15) or days 1-19 (concurrent schedule, n022). Two courses of CRT were given. The results of CRT were complete response in nine patients, partial response in 19, no change in three (minor response in two), and progressive disease in six patients. The median response duration in all responders was 172 days (range: 56-2469, n=19). After CRT, 13 patients received surgery. In 12 of these patients, tumors were completely resected. Histopathologic examination of the resected specimen revealed a discrepancy between clinical response and histopathologic effect. The median duration of survival and the 1-, 2- and 5-year survival rates were 304 days (84-3155), 45%, 35% and 23% in all patients, respectively, 866 days (190-3155), 83%, 83% and 57% in the 13 patients whose tumors were resected, and 187 days (84--2630), 25%, 5% and 5% in the 24 patients whose tumors were not resected. Grade 3 toxicity, especially hematological reactions, was noted in 13.5% (5/37) of the patients. There was one toxicity-related death (sepsis). A good outcome may be obtained with CRT, followed by surgery when feasible. However, CRT can cause toxic reactions, and close monitoring of patients is required.

Type-specific separation of animal cells in aqueous two-phase systems using antibody conjugates with temperature-sensitive polymers

A new type of aqueous two-phase system (ATPS) has been developed in which a temperature-sensitive polymer, poly-N-isopropylacrylamide [poly (NIPAM)] was used as a ligand carrier for the specific separation of animal cells. Monoclonal antibodies were modified with itaconic anhydride and copolymerized with N-isopropylacrylamide, and the ligand-conjugated carriers were added to the polyethylene glycol 8000-dextran T500 aqueous two-phase systems. The antibody-polymer conjugates were partitioned to the top phase in the absence or presence of 0.15 M NaCl. When ligand-conjugated carriers were used, more than 80% of the cells were specifically partitioned to the top phase in the presence of NaCl up to 0.1 M. The cells were partitioned almost completely to the bottom phase at 0.1 M NaCl or above, when no antibody-conjugate was added in the ATPS. As a model system, CD34-positive human acute myeloid leukemia cells (KG-1) were specifically separated from human T lymphoma cells (Jurkat) by applying anti-CD34 conjugated with poly-N-isopropylacrylamide in the aqueous two-phase system. By the temperature-induced precipitation of the polymer, about 90% of the antibody-polymer conjugates were recovered from the top phase, which gave approximately 75% cell separating efficiency in the next cycle of reuse.

[The new portable system for home enteral nutrition, Portermate, made a patient possible go out for a long time: report of a case]

The patient, who is received home enteral nutrition (HEN) for a long time in a day, has problems on moving all days. Now, we tried Portermate, which is new portable devices for HEN, in his clinical care. The patient is chronic pancreatitis, and his clinical problems becomes to be worse after he ate. He was under total enteral nutrition via jejunostomy. His clinical complications were almost controlled after HEN, but he has a few complains receiving enteral nutrition. He would not move easily, for an old HEN system was not compact to move. Portermate made him go everywhere he wanted any time. It extremely improved his QOL under HEN. He continues to use Portermate.

[Structural quantification of bone from radiographs using power spectral analysis]

Bone mineral density (BMD) and bone structure are very important indices for prevention of fracture. However, it is very difficult to quantify bone structure, and only a few indices for structural quantification of bone have been reported. The purpose of this research was to investigate a new index for bone structure. The subjects were 52 women aged from 20 to 85 years. Directivity index (DI) is a new index of bone structure calculated by directivity of power spectrum from radiographs of metacarpal bone using fast Fourier transform (FFT). DI was obtained by subtracting the integral power value at 0 and 90 degree directions on the x-y plane of the two-dimensional power spectrum of bone from the integral power value at a direction of 45 degrees. A significant relationship between BMD and DI was indicated by correlation coefficient. However, no significant relationship between BMD and the first moment of the Fourier power spectrum or the fractal dimension was found. There is a possibility that DI estimates a slight deformation of bone structure. In the future, we will apply DI to the prevention of fractures and osteoarthritis.

Production of transgenic quails with high frequency of germ-line transmission using VSV-G pseudotyped retroviral vector

We report here the production of transgenic quails using a replication-defective pantropic retroviral vector based on Moloney murine leukemia virus (MoMLV) pseudotyped with vesicular stomatitis virus G protein (VSV-G). The retroviral vector was injected into laid quail embryos at the blastodermal stage, and the embryos were incubated to hatch to produce G(0) transgenic quails. Among 134 embryos subjected to viral injection, 37 hatched. The viral vector sequence was detected in the tissues of all G(0) quails. The germ-line transmission efficiency of G(0) quails mated with nontransgenic quails was more than 80% on average. Southern blot analysis revealed that the G(1) transgenic progeny had one to three copies of the transgene. The expression of vector-encoded neomycin-resistance gene under the control of the Rous sarcoma virus (RSV) promoter was observed in several tissues including heart and muscle of both G(1) and G(2) transgenic offspring. Due to the high frequency of germ-line transmission, this method may markedly facilitate the production of transgenic avian.

Cholecystokinin-8 (CCK-8) has no effect on heart rate in rats lacking CCK-A receptors

Heart rate responses to i.v. administration of cholecystokinin-8 (CCK-8) were investigated in Otsuka Long-Evans Tokushima Fatty (OLETF) rats lacking CCK-A receptors and control Long-Evans Tokushima Otsuka (LETO) rats. The heart rate decreased after i.v. administration of 3 nmol.kg(-)(1) of CCK-8 in LETO rats, but not in OLETF rats. Bradycardia in the LETO rats disappeared after treatment with MK-329, but not after treatment with L-365,260. The expression of CCK-A receptor precursor mRNA was found exclusively in the atrium in LETO rats. These results suggest that CCK-8 decreases heart rate via CCK-A receptors located in the atrium of the rats.

Novel polygonized single-wall carbon nanotube bundles

We have synthesized novel crystalline ropes of "polygonized" single-wall carbon nanotubes (SWCNTs). The tubes exhibit rounded-hexagonal cross sections in contrast to the earlier observations of nearly circular tubes. To investigate the structural characteristics of the lattice of SWCNTs we have performed extensive molecular-dynamics simulations. We find several metastable structures of the lattice characterized by different tube cross sections, hexagonal, rounded-hexagonal, and circular, and increasing cell volume. The competition between different tube shapes as a function of tube diameter is analyzed and compared to experiments.

Construction of tumor-specific cells expressing a membrane-anchored single-chain Fv of anti-ErbB-2 antibody

Cells expressing a membrane-anchored single-chain fragment variable (scFv) domain against a tumor-specific antibody were fabricated. These cells were able to bind to cells of a human colon cancer line (BM314) expressing the erbB-2 proto-oncogene. A plasmid, pMFverbB, was first constructed in which the anti-ErbB-2 scFv gene was cloned in-frame between a signal peptide sequence and the platelet-derived growth factor receptor (PDGFR) transmembrane domain gene to express scFv on the cell surface. An African green monkey cell line, COS-1, was stably transfected with pMFverbB. Immunofluorescence assay experiments and microscopic observation showed that the cells expressing scFv bound to the human tumor cells overexpressing the ErbB-2 protein as well as to cells of a mouse fibroblast line (NIH-3T3) transfected with the erbB-2 gene. The cells expressing scFv could take up magnetite cationic liposomes as a model of particle-type drug and retained the ability to target ErbB-2-expressing cells. The fabricated cells have the potential to serve as drug carriers in drug targeting applications.

Expression of chromatin remodeling factors during neural differentiation

The yeast SWI/SNF complex is involved in remodeling of chromatin structure during transcriptional modulation. One of the key subunits of this complex, called SWI2/SNF2, has a DNA-dependent ATPase activity. Two different types of mammalian homolog of yeast SWI2/SNF2, called BRM and BRG1, were recently identified. They are closely similar in structure but have distinct functions. We investigated the expression of BRM and BRG1 during differentiation of neural precursor cells (NPCs) cultured in vitro. The expression of BRM was very low in NPCs and was induced to a high level during differentiation to neurons and astrocytes. In contrast, BRG1 was constantly expressed throughout differentiation. These phenomena were also observed in differentiation of P19 embryonal carcinoma cells to neural cells. Immunocytochemical analyses revealed that the expression of BRM started even in the undifferentiated nestin-positive cells. These results indicate that BRM may have an important role in neural cell differentiation.

Protamine-modified DDAB lipid vesicles promote gene transfer in the presence of serum

Cationic lipid vesicle-mediated gene transfer has become common for in vitro gene delivery. However, the transfection efficiency is often impaired by serum. DDAB (dimethyldioctadecyl ammonium bromide) lipid vesicle-mediated gene transfer, which we previously reported, has the same problem. To overcome this obstacle, we here report a novel transfection vehicle using protamine-modified DDAB lipid vesicles. While free protamine was simply added to the DNA/lipid complex in the previous study, in the present method the protamine is chemically conjugated to stearic acid and incorporated into DDAB lipid vesicles. Gene transfer was not significantly inhibited in 10% serum-containing medium by this method for the transfection of cultured cells. Protamine-modified DDAB lipid vesicles also enhanced virus transduction efficiency in the presence of serum using a replication-defective retroviral vector. Furthermore, the vesicles allowed efficient gene transfer for avian embryos in vivo. These results indicate that the method is useful for the production of transgenic animals and gene therapy.

Element-selective single atom imaging

Electron energy-loss spectroscopy (EELS) is widely used to identify elemental compositions of materials studied by microscopy. We demonstrate that the sensitivity and spatial resolution of EELS can be extended to the single-atom limit. A chemical map for gadolinium (Gd) clearly reveals the distribution of Gd atoms inside a single chain of metallofullerene molecules (Gd@C82) generated within a single-wall carbon nanotube. This characterization technique thus provides the "eyes" to see and identify individual atoms in nanostructures. It is likely to find broad application in nanoscale science and technology research.

One-dimensional metallofullerene crystal generated inside single-walled carbon nanotubes

Electron microscope imaging for gadolinium metallofullerenes encapsulating in single-wall carbon nanotubes [(Gd@C82)n@SWNTs] identifies the single Gd atom encaged in each. The intermolecular distance between Gd@C82 is extremely regular, regarding the chains of Gd@C82 as novel one-dimensional crystals. Chemical state analysis of Gd atoms suggests evidence for charge transfer from Gd to either a fullerene cage or a nanotube. The slopes of the temperature dependence of electric resistance for the mat-like films of (Gd@C82)n@SWNTs and (C60)n@SWNTs are much steeper than that for empty SWNTs, suggesting the electron scattering due to the electrostatic potential from inside fullerenes playing an important role.

[Enteral nutrition for gastrointestinal disease in home care]

We report 5 patients given enteral feeding in order to continue its nutritional supportive care of our hospital. In patients 1, 2, and 3 who were malnourished, enteral nutrition was provided due to poor oral intakes after surgical treatment. In patients 4 and 5, enteral feedings were made via the proximal jejunum in order to bypass the duodenum, for nutrients in the duodenum enhanced their biliary infection or chronic pancreatitis, respectively. All patients' nutritional status was satisfactory, but two of five patients could not be discharged from the hospital. The reason was that the patients and their families wanted to continue the hospital care in spite of the improvement in the clinical problem. They had no help at home to care for the patient. We conclude that enteral nutrition is very useful for gastrointestinal disease, but that social problems affect home care with enteral nutrition.

Oral supplementation with gamma-linolenic acid extracted from Mucor circinelloides improves the deformability of red blood cells in hemodialysis patients

BACKGROUND

The development of abnormalities in red blood cell (RBC) deformability in patients undergoing hemodialysis remains a major problem, because it is related to peripheral microcirculation, oxygen supply, and various complications in such patients. gamma-Linolenic acid (GLA; 18:3n-6), one of the polyunsaturated fatty acids and a precursor of prostaglandin E(1), is reported to have a favorable effect on the deformability of circulating blood cells in diabetic patients.

METHODS

In order to clarify the efficacy of GLA on RBC deformability in 7 patients undergoing maintenance hemodialysis, we examined in a pilot study the changes in the deformability of RBC and the changes in the phospholipid fatty acid composition in both plasma and RBC membrane before and after high-dose oral supplementation with GLA derived from Mucor circinelloides for 12 weeks.

RESULTS

Before supplementation, the micropore passage time of RBC suspension, which is an indicator of RBC deformability, in these patients was markedly longer than that in healthy control subjects. After administering GLA, the prolonged passage time of the patients both rapidly and steadily decreased and nearly reached control levels. Light microscopic observations of RBCs using Giemsa stain revealed a decreased number of poikilocytes after supplementation. An analysis of the fatty acid composition before treatment and 8 weeks after starting the treatment showed the dihomo-gamma-linolenic acid (DGLA; 20:3n-6) level in the plasma to have increased (p < 0.05), while the arachidonic acid (AA; 20:4n-6) concentration in the RBC membrane decreased (p < 0.05). The level of DGLA in the RBC membrane, the level of GLA, and the ratio of GLA + DGLA/AA in plasma and RBC membrane did not change significantly; however, these all tended to increase.

CONCLUSION

The results of this pilot study indicate that the oral supplementation of GLA extracted from M. circinelloides improves the poor RBC deformability in hemodialysis patients, partly by inducing changes in the composition of fatty acids in plasma and RBC membrane.

Compressibility and polygonization of single-walled carbon nanotubes under hydrostatic pressure

Single-walled carbon nanotubes show linear elasticity under hydrostatic pressure up to 1.5 GPa at room temperature. The volume compressibility, measured by in situ synchrotron x-ray diffraction, has been determined to be 0.024 GPa (-1). Theoretical calculations suggest that single-walled carbon nanotubes are polygonized when they form bundles of hexagonal close-packed structure and the intertubular gap is smaller than the equilibrium spacing of graphite (002) (d = 3.35 A). It has also been determined that the deformation of the trigonal nanotube lattice under hydrostatic pressure is reversible up to 4 GPa, beyond which the nanotube lattice is destroyed.

[SIRS in surgical stress]

It has been suggested that SIRS are triggered by superfluous pro-inflammatory cytokine production, and that organ injury is caused by uncontrolled inflammatory responses. However, the results of clinical studies, on the usefulness of specific cytokine antagonists and anti-TNF antibodies for the treatment of septic shock, have been unsatisfactory. The reason for this might have been that when uncontrolled inflammatory reactions progressed locally, anti-inflammatory reactions were elevated in the circulated blood by way of CARS, thus the timing of administration and pharmacokinetics did not match clinical course. Recent research has shown that SIRS is always accompanied by CARS, and since it seems to do the amplitude of SIRS and CARS to each other so that there may be a deep valley, if there is a high mountain. We introduce the recent knowledge which indicates that SIRS is a preliminary alert for not only organ dysfunction but also immunosuppression after severe injury or major surgery.

Uterine myxoid leiomyosarcoma

BACKGROUND

Uterine myxoid leiomyosarcoma is rare, has a poor prognosis, and must be distinguished from a uterine myoma with myxomatous change.

CASE

A 56-year-old woman with a history of epigastric pain and generalized abdominal swelling had a peritoneal cavity filled with tumor that originated from the posterior uterine wall. Chemotherapy and two operations for recurrence could not prevent fatal metastases to the vascular system. Histopathology showed a typical myxoid leiomyosarcoma.

CONCLUSION

Although the patient's prognosis was poor, no mitoses were observed, and the nuclear abnormalities were not sufficient to diagnose the tumor as malignant at the initial surgery. Whenever a uterine myoma with myxomatous change is found, the patient should be monitored carefully.

An alternative method of arterial reconstruction after hepatic arterial thrombosis following living-related liver transplantation

BACKGROUND

Hepatic artery thrombosis (HAT) remains an important cause of graft loss after liver transplantation. Emergency rearterialization methods are limited in cases of living-related liver transplantation in which the graft hepatic artery is thin and short.

CASE

A 19-year-old woman who underwent living-related liver transplantation for biliary atresia developed HAT on the 4th postoperative day. During the emergency laparotomy the recipient hepatic artery was found to be too short to anastomose, so the recipient's right gastroepiploic artery was anastomosed to the graft hepatic artery. The patient is now alive and well 6 months after reoperation, and she has experienced no further episode of HAT.

CONCLUSION

The right gastroepiploic artery can be used easily and safely for hepatic graft revascularization without causing ischemia of the stomach. An additional skin incision is not required, and the artery is long enough to anastomose to the graft artery directly. The method of hepatic graft rearterialization described here is an important option for patients who undergo living-related or split liver transplantation.

Changes of alpha1-acid glycoprotein microheterogeneity in acute inflammation stages analyzed by isoelectric focusing using serum obtained postoperatively

The relationship between variations of alpha1-acid glycoprotein (orosomucoid, AGP) microheterogeneity detected from isoelectric focusing (IEF) patterns and clinical stage of acute inflammation based on serum C-reactive protein (CRP) levels and interleukin-6 (IL-6) levels was investigated. Serum samples were obtained from healthy subjects, and from patients with esophageal or stomach carcinoma before and after operation. Samples without neuraminidase treatment were used for AGP microheterogeneity analysis, and samples with neuraminidase treatment for AGP heterogeneity analysis. In AGP microheterogeneity, nine bands were detected in the range of pI 3.18-3.57 in sera obtained from healthy subjects. In patients, AGP microheterogeneity changed the first day after operation; the percentage of bands surrounding pI 3.5 increased, and the highest value appeared in sera taken the first or second day after operation and then decreased quickly. These bands showed reactivity for concanavalin A (Con A). The increase in Con A-reactive AGP occurred later than the increase in IL-6, and occurred earlier than the increase in CRP. On the seventh day after operation, the percentage of bands around pI 3.2 increased. These bands showed the reactivity for Datura stramonium agglutinin. On the other hand, in samples with neuraminidase treatment, little change of AGP heterogeneity was observed in most samples, which did not reflect the stage of inflammation. These findings suggested that AGP microheterogeneity detection was a useful marker for the clinical stage of inflammation.

Structure and function of a novel coliphage-associated sialidase

A coliphage named 63D, isolated previously, associated sialidase as a component of phage particles. In order to localize the enzyme in phage particles, phages were partially destroyed by sonication, and the disrupted particles were size fractionated using a sucrose density gradient. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, enzyme assay and electron micrography of the fractions revealed the enzyme to be composed of four identical subunits with a molecular mass of 90 kDa, and the subunits were cross-linked by disulfide bonds. Electron micrographic observation indicated that six enzyme molecules were localized in a phage tail plate as a hexagonal array.

Molecular cloning and characterization of a novel bacteriophage-associated sialidase

Bacteriophage 63D, previously isolated from sewage, is associated with alpha-2,8-linked polysialic acid degrading activity. We cloned a DNA fragment containing the sialidase gene from a 63D phage genomic library and the enzyme was functionally expressed in Escherichia coli. Determination of the nucleotide sequence of the fragment revealed that it contained one open reading frame (ORF) coding for a 108-kDa polypeptide consisting of 984 amino acid residues. The fragment had promoter sequences similar to the E. coli consensus promoters for sigma70. The deduced amino acid sequence of the central region of the ORF showed homology to those of phages K1F (51.6% identity) and PK1E (51.7% identity) endosialidases. Two Asp-box motifs that are widely found in sialidases were conserved. Purification of the soluble enzyme from lysed culture broth of infected E. coli yielded a 90-kDa protein upon SDS polyacrylamide gel electrophoresis, suggesting that the primary translational product is processed to the mature 90-kDa protein. The molecular mass of the enzyme was determined as 360 kDa by gel filtration, indicating that the native enzyme was probably a tetramer of identical 90-kDa subunits.

Transcriptional regulation of nir and nor operons of Paracoccus denitrificans

Transcripts of nitrite reductase (nir) and nitric oxide reductase (nor) operons of Paracoccus denitrificans were expressed only under anaerobic conditions in the presence of potassium nitrite. The nir and nor operons produced at least two transcription products. Large transcripts seemed to contain whole operons and small ones seemed to contain the genes encoding denitrifying enzymes. All transcription start sites were detected 41.5 or 42.5 bp downstream from the center of FNR boxes.

New detection method after cellulose acetate membrane isoelectric focusing: activity staining for lactate dehydrogenase, detection for sugar chains using lectin and simple western blotting

To extend the clinical applications for cellulose acetate (CA) membrane isoelectric focusing, we designed two detection methods and two blotting methods that improve the characteristics of the CA membrane; that is, detection of the lactate dehydrogenase (LD) isozyme on the CA membrane, detection of the sugar chain in glycoprotein on the CA membrane, and simple and rapid methods for western blotting. In the detection of the LD isozyme, when 50% saturated ammonium sulfate solution was used as a fixing solution, five main LD bands and seven sub LD bands were detected clearly. By treating the CA membrane with 5% sulfosalicylic acid, glycoprotein was fixed on the CA prior to detection of the sugar chain of glycoprotein using Lens Culinaris (LCA), Phasseolus Vulgaris-L(4 )(PHA-L(4)), Maackia Amurensis (MAM), and Sambucus Siedoldiana (SSA) lectins. Using this procedure, clear electrophoretic patterns were obtained. As simple and rapid methods for blotting proteins on polyvinylidene difluoride membranes, we designed natural contact blotting and suction blotting techniques. The natural contact blotting method did not need special apparatus. The suction blotting method completed protein blotting for 10 minutes. By both methods, clear electrophoretic patterns were obtained.

Heterostructures of single-walled carbon nanotubes and carbide nanorods

A method based on a controlled solid-solid reaction was used to fabricate heterostructures between single-walled carbon nanotubes (SWCNTs) and nanorods or particles of silicon carbide and transition metal carbides. Characterization by high-resolution transmission electron microscopy and electron diffraction indicates that the heterostructures have well-defined crystalline interfaces. The SWCNT/carbide interface, with a nanometer-scale area defined by the cross section of a SWCNT bundle or of a single nanotube, represents the smallest heterojunction that can be achieved using carbon nanotubes, and it can be expected to play an important role in the future fabrication of hybrid nanodevices.

Molecular characterization of type-specific capsular polysaccharide biosynthesis genes of Streptococcus agalactiae type Ia

The type-specific capsular polysaccharide (CP) of a group B streptococcus, Streptococcus agalactiae type Ia, is a high-molecular-weight polymer consisting of the pentasaccharide repeating unit 4)-[alpha-D-NeupNAc-(2-->3)-beta-D-Galp-(1-->4)-beta-D-GlcpNAc-(1- ->3 )]-beta-D-Galp-(1-->4)-beta-D-Glcp-(1. Here, cloning, sequencing, and transcription of the type Ia-specific capsular polysaccharide synthesis (cps) genes and functional analysis of these gene products are described. A 26-kb DNA fragment containing 18 complete open reading frames (ORFs) was cloned. These ORFs were designated cpsIaA to cpsIaL, neu (neuraminic acid synthesis gene) A to D, orf1 and ung (uracil DNA glycosylase). The cps gene products of S. agalactiae type Ia were homologous to proteins involved in CP synthesis of S. agalactiae type III and S. pneumoniae serotype 14. Unlike the cps gene cluster of S. pneumoniae serotype 14, transcription of this operon may start from cpsIaA, cpsIaE, and orf1 because putative promoter sequences were found in front of these genes. Northern hybridization, reverse transcription-PCR, and primer extension analyses supported this hypothesis. DNA sequence analysis showed that there were two transcriptional terminators in the 3' end of this operon (downstream of orf1 and ung). The functions of CpsIaE, CpsIaG, CpsIaI, and CpsIaJ were examined by glycosyltransferase assay by using the gene products expressed in Escherichia coli JM109 harboring plasmids containing various S. agalactiae type Ia cps gene fragments. Enzyme assays suggested that the gene products of cpsIaE, cpsIaG, cpsIaI, and cpsIaJ are putative glucosyltransferase, beta-1, 4-galactosyltransferase, beta-1,3-N-acetylglucosaminyltransferase, and beta-1,4-galactosyltransferase, respectively.

Nucleotides and intestine

BACKGROUND

Dietary nucleotides play an important role in the growth and development of the intestine. Parenteral supplementation of nucleic acids may be necessary to maintain the mucosal proliferation and barrier functions during parenteral nutrition (PN).

METHODS

Male Wistar rats were divided into 3 groups: FED (food ad libitum with saline infusion); PN (a standard PN solution); and OG (OG-6, a mixture of nucleotide and nucleosides, in addition to the PN solution). The mucosal wet weight, protein, and DNA contents, villous height and crypt depth, electronmicroscopic examination of the intercellular junctions, proliferating activity of the mucosal cells, mucosal permeability, bacterial translocation, and mucosal cathepsin activities were examined.

RESULTS

The wet weight, protein, and DNA contents of the jejunal mucosa were significantly increased in the OG group, compared with those in the PN group. The morphometric examination revealed a significant increase in the villous height but not in the crypt depth in the OG group. The widths of both the tight and intermediate junctions were narrower in the OG group than those in the PN group. The activity of diamine oxidase was increased in the OG group, compared with that in the PN group. The ratio of proliferating cell nuclear antigen positive cells and the index of bromodeoxy uridine labeling index in the OG group were as high as in the FED group, and significantly higher than those in the PN group. The portal concentration of fluorescein isothiocyanate-dextran 70,000 after intragastric loading was significantly higher in the PN group than that in OG group. Likewise, the rate of urinary lactulose excretion after intragastric loading was higher in the PN group. The positive rate of bacteria cultured in mesenteric lymph nodes was higher in the PN group than in the OG group although the difference was not significant. The activities of mucosal cathepsins (B, H, and L), markers for phagocytic degradation of extrinsic substances and organisms, were higher in the PN group than those in the OG and FED groups.

CONCLUSIONS

Parenteral supplementation of nucleic acids supports the mucosal cell proliferation and functions.