[Application value of laparoscopic double stapler firings and double stapling technique combined with rectal eversion and total extra-abdominal resection in the sphincter-preserving resection of low rectal cancer]

Objectives: To investigate the application value of laparoscopic double stapler firings and double stapling technique combined with rectal eversion and total extra-abdominal resection (LDER) in the anal preservation treatment of low rectal cancer. Methods: Inclusion criteria: (1) age was 18-70; (2) the distance of the lower tumor edge from the anal verge was 4-5 cm; (3) primary tumor with a diameter ≤3 cm; (4) preoperative staging of T1~2N1~2M0; (5) "difficult pelvis", defined as ischial tuberosity diameter<10 cm or body mass index>25 kg/m2; (6) patients with strong intention for sphincter preservation; (7) no preoperative treatment (e.g., chemotherapy, radiotherapy, molecular targeted therapy, or immunotherapy); (8) no lateral lymph node enlargement; (9) no previous anorectal surgery; (10) patients with good basic condition who could tolerate surgery. Exclusion criteria: (1) previously suffered from malignant tumors of the digestive tract or currently suffering from malignant tumors out of the digestive tract; (2) patients with preoperative anal dysfunction (Wexner score ≥ 10), or fecal incontinence. The specific surgical steps are as follows: the distal end of the rectum was dissected to the level of the interspace between internal and external sphincters of anal canal. Five centimeters proximal to the tumor, the mesorectum was ligated, and a liner stapler was used to transect the rectum. The distal rectum with the tumor were then everted and extracted through the anus. The rectum was transected 0.5-1.0 cm distal to the tumor with a linear stapler. Full thickness suture was used to reinforce the stump of the rectum, which was then brought back into the pelvic cavity. Finally, an end-to-end anastomosis between the colon and the rectum was performed. A retrospective descriptive study was performed of the clinical and pathological data of 12 patients with T1-T2 stage low rectal cancer treated with LDER at Henan Provincial People's Hospital from January 2020 to December 2022. Results: All 12 patients successfully completed LDER with sphincter preservation, without conversion to open surgery or changes in surgical approach. The median surgical time was 272 (155-320) minutes, with a median bleeding volume of 100 (50-200) mL. No protective stoma was performed, and all patients received R0 resection. The average hospital stay was 9 (7-15) days. There were no postoperative anastomotic leakage or perioperative deaths. All 12 patients received postoperative follow-up, with a median follow-up of 12 months (6-36 months) and a Wexner score of 8 (5-14) at 6 months postoperatively. There was no tumor recurrence or metastasis during the follow-up period. Conclusions: LDER is safe and effective for the treatment of low rectal cancer.

Deep Underground Laboratory Measurement of ^{13}C(α,n)^{16}O in the Gamow Windows of the s and i Processes

The ^{13}C(α,n)^{16}O reaction is the main neutron source for the slow-neutron-capture process in asymptotic giant branch stars and for the intermediate process. Direct measurements at astrophysical energies in above-ground laboratories are hindered by the extremely small cross sections and vast cosmic-ray-induced background. We performed the first consistent direct measurement in the range of E_{c.m.}=0.24 to 1.9 MeV using the accelerators at the China Jinping Underground Laboratory and Sichuan University. Our measurement covers almost the entire intermediate process Gamow window in which the large uncertainty of the previous experiments has been reduced from 60% down to 15%, eliminates the large systematic uncertainty in the extrapolation arising from the inconsistency of existing datasets, and provides a more reliable reaction rate for the studies of the slow-neutron-capture and intermediate processes along with the first direct determination of the alpha strength for the near-threshold state.

Geolocation Inference of Forensic Individual Origin by Soil Metagenomic Analysis

Abstract

Objective To preliminarily discuss the feasibility of geolocation inference of forensic individual origin by soil metagenomic analysis. Methods The 33 soil samples from Heilongjiang, Qinghai and Tibet were collected, total bacterial DNA in the samples were extracted, and universal primers were used to amplify the V3 and V4 hypervariable region of bacterial 16S rDNA. The region was sequenced by high-throughput sequencing （HTS） with the MiSeq sequencer. Bioinformatics analysis such as species composition and sample comparison was performed on sequencing data. The richness index and diversity index were calculated based on operational taxonomic unit （OTU） results. Results A total of 2 720 149 sequences were generated by sequencing. Those sequences were clustered into 114 848 OTUs. The Chao1 indexes of soil microorganisms in Heilongjiang, Qinghai, and Tibet were 797.45, 745.11 and 535.98, respectively, and Shannon indexes were 6.46, 6.36 and 6.25, respectively. The number of bacterial species and the community diversity in the soil from high to low were Heilongjiang > Qinghai > Tibet. The composition of soil bacteria in three provinces at various classification levels were obtained, the dominant genuses in Heilongjiang were Chthoniobacteraceae DA101 and an unannotated genus of Thermogemmatisporaceae; the dominant genuses in Qinghai were an unannotated genus of Cytophagaceae and an unannotated genus of Nocardioidaceae; the dominant genuses in Tibet were an unannotated genus of Comamonadaceae and Verrucomicrobiaceae Luteolibacter. The results of principal co-ordinates analysis demonstrated that, according to the weighted UniFrac analysis, the three principle components represented 56.36% of the total variable, and according to the unweighted UniFrac analysis, the three principle components represented 34.81% of the total variable. The samples from the same province could be clustered together, and the species and content of soil microorganisms from different provinces were significantly different. Conclusion Based on the metagenomic analysis method, soil samples from different regions can be effectively distinguished, which has potential application value in geolocation inference of forensic individual origin in the future.

Constraining the External Capture to the ^{16}O Ground State and the E2 S Factor of the ^{12}C(α,γ)^{16}O Reaction

The ^{12}C(α,γ)^{16}O reaction is one of the most crucial reactions in nuclear astrophysics. The E2 external capture to the ^{16}O ground state (GS) has not been emphasized in previous analyses but may make a significant contribution to the ^{12}C(α,γ)^{16}O cross section depending on the value of the GS asymptotic normalization coefficient (ANC). In the present work, we determine this ANC to be 337±45  fm^{-1/2} through the ^{12}C(^{11}B,^{7}Li)^{16}O reaction using a high-precision magnetic spectrograph. This sheds light on the existing large discrepancy of more than 2 orders of magnitude between the previously reported ANC values. Based on the new ANC, we experimentally constrain the GS external capture and show that through interference with the high energy tail of the 2^{+} subthreshold state, a substantial enhancement in the GS S_{E2}(300) factor can be obtained (70±7  keV b) compared to that of a recent review (45 keV b), resulting in an increase of the total S factor from 140 to 162 keV b, which is now in good agreement with the value obtained by reproducing supernova nucleosynthesis calculations with the solar-system abundances. This work emphasizes that the external capture contribution for the ground state transition cannot be neglected in future analyses of the ^{12}C(α,γ)^{16}O reaction.

Cost-effectiveness of Basal Flow Sevoflurane Anaesthesia Using the Komesaroff Vaporizer inside the Circle System

After ethics committee approval, 51 consenting ASA physical status 1 or 2 adult patients were given basal flow sevoflurane anaesthesia using fresh gas flows of 150 to 300 ml.min-1 oxygen. A Komesaroff vaporizer was placed on the inspiratory limb of the circle system. Basal flows were introduced immediately following intravenous induction of anaesthesia. The vaporizer was set to deliver the maximum concentration until the inspired sevoflurane concentration (FSI) reached 3%. The dial was then adjusted to maintain the FSI at 3%. After every 60 minutes, the circuit was washed out with 100% oxygen at a flow rate of 10 l.min-1 for one minute.

The FSI reached 3% after an average of 8.5 (3.8) [mean (SD)] minutes. The trends in FSI and the expired sevoflurane concentrations were significantly different (P<0.05) between the mechanically ventilated patients (n=21) and the spontaneously ventilating patients (n=30) and demonstrated a more gradual build-up in the former group. The consumption of sevoflurane was found to be 9.2 (2.8) ml.h-1. This represented a 52.5% cost saving over the clinical application of the Mapleson's ideal fresh gas flow sequence for low-flow anaesthesia.

The value of multislice spiral CT features of cavitary walls in differentiating between peripheral lung cancer cavities and single pulmonary tuberculous thick-walled cavities

OBJECTIVES

Form discordance of cavity walls (FDCW) and form concordance of cavity walls (FCCW) in multislice spiral CT (MSCT) were investigated to determine their value in differentiating between peripheral lung cancer cavities and single pulmonary tuberculous thick-walled cavities. An assessment of the role of multiplanar reconstruction (MPR) in detecting FDCW and FCCW was also performed.

METHODS

MSCT cross-sectional images of 116 consecutive cases (including 60 cases with available MPR images) with peripheral lung cancer cavities and 118 consecutive cases (including 62 cases with available MPR images) with single pulmonary tuberculous thick-walled cavities (wall thickness >3 mm) were retrospectively analysed. According to the characteristics of cavitary internal and external walls on MSCT, these cavities were divided into two types (FDCW and FCCW). FDCW was further divided into three subtypes (FDCW-I, FDCW-II and FDCW-III); FCCW was further divided into two subtypes (FCCW-I and FCCW-II).

RESULTS

On the cross-sectional and MPR images, the total detection rate of FDCW-I and FDCW-III in peripheral lung cancer cavities was 76.7% (89/116) and 93.3% (56/60), respectively, whereas the total detection rate of FCCW-I and FCCW-II in single pulmonary tuberculous thick-walled cavities was 75.4% (89/118) and 91.9% (57/62), respectively.

CONCLUSIONS

FDCW-I, FDCW-III, FCCW-I and FCCW-II were valuable in differentiating between peripheral lung cancer cavities and single pulmonary tuberculous thick-walled cavities. MPR could improve the detection of FDCW-I and FDCW-III in peripheral lung cancer cavities and FCCW-I and FCCW-II in single pulmonary tuberculous thick-walled cavities.

Characterization and comparison of microbial community of different typical Chinese liquor Daqus by PCR-DGGE

AIMS

To identify and compare microbiota in Chinese liquor Daqu, which were produced in the different regions using different production process.

METHODS AND RESULTS

The DNA exacted from Daqu samples was used as a template for PCR with universal primers of 16S rRNA, 26S rRNA and 18S rRNA, respectively. The amplicons were analysed using denaturing gradient gel electrophoresis (DGGE). It was observed that the bacterial DGGE profile indicated high diversity and predominance of lactic acid bacteria. The results showed that Saccharomycopsis fibuligera and Pichia anomal were dominant yeast species and that several non-Saccharomyces yeasts including Hanseniaspora guilliermondii, Debaryomyces hansenii, Issatchenkia orientalis and Trichosporon asahii were also detected. As for fungal DGGE, Aspergillus oryzae and Absidia blakesleeana were the most common species amongst different samples. Based on the DGGE analysis, a few differences in community structure were found between Daqu samples.

CONCLUSIONS

A variety of bacteria, yeast and moulds were identified in Daqu samples, in addition to the present knowledge obtained mainly through the traditional culture-dependent methods. Moreover, production temperature played a more decisive role on the formation of micro-organism composition in Daqu than geographical region.

SIGNIFICANCE AND IMPACT OF THE STUDY

PCR-DGGE technique was used in this study to fully observe and asses all microbial community (including bacteria, yeast and mould) in Chinese liquor Daqu for the first time and proved to be effective in profiling Daqu microbial diversity.

Disruption of the midkine gene (Mdk) resulted in altered expression of a calcium binding protein in the hippocampus of infant mice and their abnormal behaviour

BACKGROUND

Midkine (MK) is a growth factor implicated in the development and repair of various tissues, especially neural tissues. However, its in vivo function has not been clarified.

RESULTS

Knockout mice lacking the MK gene (Mdk) showed no gross abnormalities. We closely analysed postnatal brain development in Mdk(-/-) mice using calcium binding proteins as markers to distinguish neuronal subpopulations. Intense and prolonged calretinin expression was found in the dentate gyrus granule cell layer of the hippocampus of infant Mdk(-/-) mice. In infant Mdk(+/+) mice, calretinin expression in the granule cell layer was weaker, and had disappeared by 4 weeks after birth, when calretinin expression still persisted in Mdk(-/-) mice. Furthermore, 4 weeks after birth, Mdk(-/-) mice showed a deficit in their working memory, as revealed by a Y-maze test, and had an increased anxiety, as demonstrated by the elevated plus-maze test.

CONCLUSION

Midkine plays an important role in the regulation of postnatal development of the hippocampus.

A novel action of alzheimer's amyloid beta-protein (Abeta): oligomeric Abeta promotes lipid release

Interactions between amyloid beta-protein (Abeta) and lipids have been suggested to play important roles in the pathogenesis of Alzheimer's disease. However, the molecular mechanism underlying these interactions has not been fully understood. We examined the effect of Abeta on lipid metabolism in cultured neurons and astrocytes and found that oligomeric Abeta, but not monomeric or fibrillar Abeta, promoted lipid release from both types of cells in a dose- and time-dependent manner. The main components of lipids released after the addition of Abeta were cholesterol, phospholipids, and monosialoganglioside (GM1). Density-gradient and electron microscopic analyses of the conditioned media demonstrated that these Abeta and lipids formed particles and were recovered from the fractions at densities of approximately 1.08-1.18 g/ml, which were similar to those of high-density lipoprotein (HDL) generated by apolipoproteins. The lipid release mediated by Abeta was abolished by concomitant treatment with Congo red and the PKC inhibitor, H7, whereas it was not inhibited with N-acetyl-l-cysteine. These Abeta-lipid particles were not internalized into neurons, whereas HDL-like particles produced by apolipoprotein E were internalized. Our findings indicate that oligomeric Abeta promotes lipid release from neuronal membrane, which may lead to the disruption of neuronal lipid homeostasis and the loss of neuronal function.

Cholesterol-dependent modulation of tau phosphorylation in cultured neurons

One of the hallmarks of Alzheimer's disease (AD) is the abnormal state of tau. It is both highly phosphorylated and aggregated into paired helical filaments (PHFs) in neurofibrillary tangles (NFTs). However, the mechanism underlying the hyperphosphorylation of tau in NFTs and neuronal degeneration in AD remains to be elucidated. The fact that hyperphosphorylation of tau in NFTs are also found in the patients with Niemann-Pick disease, type C (NPC), which is a cholesterol storage disease associated with defective intracellular trafficking of exogenous cholesterol, implies that perturbation of cholesterol metabolism may be involved in tau phosphorylation and neurodegeneration. Here, we report that cholesterol deficiency induced by inhibition of cholesterol biosynthesis in cultured neurons results in hyperphosphorylation of tau, accompanied by axonal degeneration associated with microtubule depolymerization. These changes were prevented by concurrent treatment with beta-migrating very low-density lipoprotein (beta-VLDL) or cholesterol. We propose that intracellular cholesterol plays an essential role in the modulation of tau phosphorylation and the maintenance of microtubule stability.

Distinct expression of midkine and pleiotrophin in the spinal cord and placental tissues during early mouse development

Midkine and pleiotrophin comprise a family of heparin-binding growth factors, and are expressed in overlapping tissues during the mid- to late-gestation periods of mouse development. Their distinct expression during early mouse development, as revealed by in situ hybridization, was reported. Midkine was expressed in the embryonic ectoderm from as early as embryonic day (E5.5). In the neural tube midkine was expressed specifically in the neuroepithelium, that is, in the whole area of the neural tube at E9.5, and in the ventricular zone from E10.5-13.5. At E15.5, when the neuroepithelium disappeared, midkine concomitantly became undetectable. In contrast, pleiotrophin expression started exclusively in the neural plate at E8.5, and in the lateral plate of the neural tube at E9.5. It then became restricted to a dorsal ventricular zone from E11.5-13.5, and finally to the central gray neurons at E15.5. Moreover, pleiotrophin was expressed in the ventral horns. Among placental tissues, midkine was detected in the chorion, the fetal component of the placenta, whereas pleiotrophin was found in the decidua basalis, the maternal component of the placenta. The distinct expression of midkine and pleiotrophin suggests their differential role in early development.

Apolipoprotein E exhibits isoform-specific promotion of lipid efflux from astrocytes and neurons in culture

Many studies have shown that apolipoprotein E (apoE) plays important roles in maintaining intracellular lipid homeostasis in nonneuronal cells. However, little is known about the extracellular transport of lipids in the CNS. In this study, we determined whether and to what degree lipid efflux from astrocytes and neurons depended on apoE. Our results showed that exogenously added apoE promoted the efflux of cholesterol and phosphatidylcholine from both astrocytes and neurons in culture, resulting in the generation of high-density lipoprotein-like particles. The order of potency of the apoE isoforms as lipid acceptors was apoE2 > apoE3 = apoE4 in astrocytes and apoE2 > apoE3 > apoE4 in neurons. Treatment with brefeldin A, monensin, and a protein kinase C inhibitor, H7, abolished the ability of apoE to promote cholesterol efflux from cultured astrocytes, without altering apoE-mediated phosphatidylcholine efflux. In contrast, the efflux of both cholesterol and phosphatidylcholine promoted by apoE was abolished following treatment with heparinase or lactoferrin, which block the interaction of apoE with heparan sulfate proteoglycans (HSPGs) or low-density lipoprotein receptor-related protein (LRP), respectively. This study suggests that apoE promotes lipid efflux from astrocytes and neurons in an isoform-specific manner and that cell surface HSPGs and/or HSPG-LRP pathway may mediate this apoE-promoted lipid efflux.

Expression of the mRNA for two isoforms of neural plakophilin-related arm-repeat protein/delta-catenin in rodent neurons and glial cells

Neural plakophilin-related arm-repeat protein (NPRAP) is a mammalian brain protein of the armadillo family. Here, in an attempt to elucidate its function, we determined the mouse brain regions and cell types expressing the mRNAs for two NPRAP isoforms (the longer and the shorter isoforms), and examined the regulation of expression of the NPRAP mRNAs during the differentiation of P19 cells into neurons. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that both variants were expressed in various mouse brain regions, but the mRNA for the short isoform was predominant in most regions. Primary cultures of both neurons and glial cells exhibited high expression levels of both the mRNAs, indicating that NPRAP mRNA expression is not neuron-specific. The expression of the two NPRAP mRNA variants was dramatically induced even prior to the terminal neuronal and glial differentiation of P19 cells after retinoic acid treatment. These data suggest that the two NPRAP isoforms function not only in neurons and glial cells in the brain, but also play a role in the differentiation of precursor cells into neurons and glial cells.

Spatially and temporally regulated expression of N-acetylglucosamine-6-O-sulfotransferase during mouse embryogenesis

GlcNAc-6-O-sulfotransferase is involved in formation of 6-sulfo-N -acetyllactosamine-containing structures such as 6-sulfo sialyl Lewis x. We investigated the mode of expression of GlcNAc-6-O-sulfotransferase during postimplantation embryogenesis in the mouse by in situ hybridization. Sulfotransferase mRNA was not detected on embryonic day (E) 6.5, while on E7.5 it was detected in the mesoderm, ectoderm, and ectoplacental cone. On E10.5, the sulfotransferase signals were mainly observed in the nervous tissue. On E12.5 and 13.5, various tissues in the process of differentiation expressed this mRNA. Several epithelial and mesenchymal tissues undergoing epithelial-mesenchymal interactions strongly expressed the mRNA. For example, in the developing tooth strong sulfotransferase mRNA expression was found only in the condensing mesenchyme on E13.5. On E13.5 and 15.5, the sites showing intense expression of the sulfotransferase again became restricted. In the brain, sulfotransferase mRNA was frequently found as discrete signals in narrow regions. These results suggest that 6-sulfo-N-acetyllactosamine structures have important roles in development. On E13.5 and 15.5, G152 (6-sulfo sialyl Lewis x antigen) was expressed in the neocortex, and AG223 (6-sulfo Lewis x antigen) in the thalamus and neocortex where the sulfotransferase signal was detected. However, in other organs, expression of these antigens did not correlate with the sulfotransferase mRNA, implicating complex nature of regulation of expression of the fucosyl 6-sulfo antigens.

Expression of midkine in the early stage of carcinogenesis in human colorectal cancer

It has been suggested that a heparin-binding growth factor, midkine (MK), plays an important role in carcinogenesis because of its frequent overexpression in various malignant tumours. To clarify whether or not MK contributes to the early stage of carcinogenesis, we examined the status of MK mRNA in 20 adenomas with moderate- and severe-grade dysplasia, 28 carcinomas and 28 corresponding normal tissues, by means of Northern blotting. The MK expression level was significantly more elevated in adenomas than in normal tissues (P < 0.001, unpaired Student's t-test). A difference was also observed between carcinomas and the corresponding normal tissues (P < 0.04, paired Student's t-test). Moreover, MK immunostaining was positive in the adenomas with moderate- and severe-grade dysplasia and in the carcinomas, but not in mild-grade dysplasia or in normal tissues. These findings were in line with those on Western blotting. In three patients with both adenomas with moderate- or severe-grade dysplasia and carcinomas, elevated MK expression was observed in the neoplastic lesions. This is the first report of the association of elevated MK expression with the early stage of carcinogenesis in humans.

Zep: A novel zinc finger protein containing a large proline-rich domain

Zep, a novel 49 kDa zinc finger protein, was found in the brain of day-13 mouse embryos and cloned. Zep contains two C2H2-type zinc finger motifs close to the N-terminal region. The majority of the molecule is composed of a proline-rich domain showing similarity to proline-rich domains in transcription factors and a salivary proline-rich protein. In addition to the proline-rich domain, Zep has an acidic domain and a serine/threonine-rich domain, all of which are frequently found in many transcription factors. The overall organization of Zep shows no similarity to any other proteins. There is a nuclear localization signal in Zep, and the Zep-GFP (green fluorescent protein) fusion protein is located predominantly in the nucleus. In the day-13 mouse embryo, Zep is strongly expressed in the nervous system, i.e. brain, spinal cord, and dorsal root ganglia, with strong to weak expression observed in other regions. Zep continues to be strongly expressed in the neonatal brain; however, its expression is weak in the brain and spinal cord of adult mice. In situ hybridization reveals strong signals for Zep mRNA in the cerebellum and olfactory bulb with moderate signals detected in the hippocampus and cortex. Strong Zep expression is observed in adult thymus, lung, spleen, testis, and ovary. Zep may be involved in the formation and remodeling of various tissues including nervous tissue, probably through transcriptional regulation.

Human N-acetylglucosamine-6-O-sulfotransferase involved in the biosynthesis of 6-sulfo sialyl Lewis X: molecular cloning, chromosomal mapping, and expression in various organs and tumor cells

N-Acetylglucosamine-6-O-sulfotransferase catalyzes the transfer of sulfate from 3'-phosphoadenosine 5'-phosphosulfate to position 6 of a non-reducing N-acetylglucosamine (GlcNAc) residue. We have cloned human GlcNAc-6-O-sulfotransferase cDNA, based on the sequence homology to cloned cDNA of mouse GlcNAc-6-O-sulfotransferase. The predicted protein sequence of the human enzyme was highly homologous to that of the mouse enzyme; in the 363 amino acid stretch of the catalytic region, the two proteins were nearly identical except for conservative changes in 3 amino acid residues. The expressed enzyme transferred sulfate to GlcNAcbeta1-3Galbeta1-4GlcNAcbeta1-3Galbeta1-4Gl cNAc. Co-transfection of the enzyme cDNA and fucosyltransferase VII cDNA into COS-7 cells resulted in cell surface expression of 6-sulfo sialyl Lewis X. Fluorescence in situ hybridization analysis revealed that the GlcNAc-6-O-sulfotransferase gene is located on human chromosome 7q31. mRNA of the human enzyme was strongly expressed in the bone marrow, peripheral blood leukocytes, spleen, brain, spinal cord, ovary, and placenta, and moderate levels of expression were observed in many organs including lymph nodes and thymus. In situ hybridization with the mouse system showed that the transcript was localized in specific regions of the brain, i.e. pyramidal cells in the CA3 subregion of the hippocampus, cerebellar nucleus and Purkinje cells. Among human tumor cells, strong expression of the mRNA was found in MOLT-4 and Jarkat lymphoblastic leukemia cells, Raji lymphoma cells, K-562 chronic myelogeneous leukemia cells, U251 glioma cells, and G361 melanoma cells. Carbohydrate structures synthesized by the sulfotransferase may be involved in various aspects of the differentiation and behavior of blood cells, their progenitor cells, and neurons in the central nervous system.

Molecular cloning and characterization of an N-acetylglucosamine-6-O-sulfotransferase

We isolated a cDNA clone encoding mouse N-acetylglucosamine-6-O-sulfotransferase based on sequence homology to the previously cloned mouse chondroitin 6-sulfotransferase. The cDNA clone contained an open reading frame that predicts a type II transmembrane protein composed of 483 amino acid residues. The expressed enzyme transferred sulfate to the 6 position of nonreducing GlcNAc in GlcNAcbeta1-3Galbeta1-4GlcNAc. Galbeta1-4GlcNAcbeta1-3Galbeta1-4GlcNAc and various glycosaminoglycans did not serve as acceptors. Expression of the cDNA in COS-7 cells resulted in production of a cell-surface antigen, the epitope of which was NeuAcalpha2-3Galbeta1-4(SO4-6)GlcNAc; double transfection with fucosyltransferase IV yielded Galbeta1-4(Fucalpha1-3)(SO4-6)GlcNAc antigen. The sulfotransferase mRNA was strongly expressed in the cerebrum, cerebellum, eye, pancreas, and lung of adult mice. In situ hybridization revealed that the mRNA was localized in high endothelial venules of mesenteric lymph nodes. The sulfotransferase was concluded to be involved in biosynthesis of glycoconjugates bearing the 6-sulfo N-acetyllactosamine structure such as 6-sulfo sialyl Lewis X. The products of the sulfotransferase probably include glycoconjugates with intercellular recognition signals; one candidate of such a glycoconjugate is an L-selectin ligand.

Embigin/basigin subgroup of the immunoglobulin superfamily: different modes of expression during mouse embryogenesis and correlated expression with carbohydrate antigenic markers

Embigin and basigin are highly glycosylated transmembrane glycoproteins with two immunoglobulin domains and form a subgroup in the immunoglobulin superfamily. Previous studies have demonstrated the functional significance of these molecules. In the present study, in situ hybridization analysis of their expression was performed during mouse embryogenesis. Embigin was strongly expressed in the endoderm during early postimplantation embryogenesis, and in the somite stage in the gut and visceral endoderm. Embryonic ectoderm and its derivative tissues weakly to moderately expressed this molecule. From day 10 to 15 of gestation, no embigin signal was detected. Basigin was more broadly expressed. During the organogenesis period, basigin was expressed in various epithelial tissues, brain ventricles, the spinal cord and dorsal root ganglion. The modes of expression of these two proteins throughout the egg cylinder stage correlated with the expression of the carbohydrate markers that they carry; embigin with Dolichos biflorus agglutinin binding sites and basigin with LeX antigen and more closely with fucosyltransferase IV, which forms the antigenic epitope. These findings imply that proteins with specific carbohydrate epitopes play roles in early postimpantation embryogenesis.

Mouse chondroitin 6-sulfotransferase: molecular cloning, characterization and chromosomal mapping

Chondroitin 6-sulfotransferase (C6ST) catalyzes the transfer of sulfate from 3'-phosphoadenosine 5'-phosphosulfate to position 6 of the N-acetylgalactosamine residue of chondroitin. Using chick C6ST cDNA as a probe, we cloned the cDNA of mouse C6ST. The mouse enzyme was predicted to be composed of 472 amino acids, and exhibited 71% sequence identity with the chicken enzyme. The mouse and chicken catalytic domains exposed to the luminal side exhibited 81% identity, while the homology of the remaining regions was less. Transfection and expression of the mouse cDNA in COS-7 cells yielded C6ST activity. Keratan sulfate sulfotransferase activity, which was simultaneously expressed, amounted to 3% of the C6ST activity, this value being significantly lower than that observed in the case of the chicken enzyme. Mouse C6ST mRNA was strongly expressed in the spleen, lung, and eye. In situ hybridization revealed that the transcript was localized in stromal cells in the marginal zone and red pulp of the spleen, and stromal cells in the bone marrow. Fluorescence in situ hybridization analysis revealed the gene is located in mouse chromosome 9.

Female sterility in mice lacking the basigin gene, which encodes a transmembrane glycoprotein belonging to the immunoglobulin superfamily

Basigin (Bsg) is a transmembrane glycoprotein belonging to the immunoglobulin superfamily. Bsg knock-out mice exhibit infertility of both sexes. Based on limited results, defective implantation has been considered to be the cause of the female infertility. We demonstrate here that disruption of the Bsg gene produces the failure of female reproductive processes including not only implantation but also fertilization. Bsg mRNA expression in cumulus cells and basolateral localization of the Bsg protein in the endometrial epithelium further support the importance of Bsg in these processes.

A null mutation in basigin, an immunoglobulin superfamily member, indicates its important roles in peri-implantation development and spermatogenesis

Basigin is a highly glycosylated transmembrane protein with two immunoglobulin-like domains. We generated mutant mice lacking the basigin gene (Bsg) by gene targeting. Bsg (-/-) embryos developed normally during preimplantation stages. However, the majority of Bsg (-/-) embryos died around the time of implantation. At this time, basigin mRNA was strongly expressed in the trophectoderm, embryo proper, and uterine endometrium of Bsg (+/+) mice. These results suggest that basigin is involved in intercellular recognition during implantation. Embryos which survived the critical period yielded Bsg (-/-) mutant mice. Half of the mutant mice died before 1 month after birth, due to interstitial pneumonia. The surviving adult mutant mice were small and sterile. Spermatogenesis was arrested in the mutant mice. Most of the spermatocytes in the Bsg (-/-) mouse were arrested and degenerated at the metaphase of the first meiosis, and only a small number differentiated to step 1 spermatids. In the female mutants, the ovaries and genital tract were morphologically normal, and the defect was probably in the capability of implantation of the uterus. In conclusion, basigin is an important cell-surface molecule involved in early embryogenesis and reproduction.

Functional modules and expression of mouse p40(phox) and p67(phox), SH3-domain-containing proteins involved in the phagocyte NADPH oxidase complex

The phagocyte NADPH oxidase is activated during phagocytosis to produce superoxide, a precursor of microbicidal oxidants. The formation of the active oxidase complex at the membrane requires translocation of the Rac GTPase and two specialized cytosolic proteins that harbor SH3 domains, p67phox and p47phox. Another SH3-domain-containing protein p40phox, which is constitutively associated with p67phox in phagocytes, also enters the complex upon cell stimulation. Here we describe how we cloned mouse cDNAs encoding p40phox and its partner in phagocytes, p67phox. Both p40phox and p67phox comprise several protein-binding modules that are structurally and functionally well conserved between mouse and human, indicating their nature as adaptor proteins. We have also systematically investigated expression of the gene for p40phox in comparison with those for p67phox and p47phox. Distributions of the mRNAs for the three proteins among tissues are similar, with the most abundant expression in the spleen. The messages are abundant not only in phagocytic cells, but also in B cell lineage. The p40phox gene, but not the other two, is expressed in some types of cells such as plasma cells and T lymphocytes. Furthermore, in situ hybridization analysis shows that the p40phox mRNA is distributed in neuronal cells of mouse brain, providing evidence that one of the genes for the specialized oxidase factors is expressed in neurons. These observations raise the possibility that the adaptor protein p40phox plays a heretofore unsuspected role via interacting with other proteins in the cells that do not express p67phox or p47phox.

Expression of basigin, a member of the immunoglobulin superfamily, in the mouse central nervous system

Basigin (Bsg) is a transmembrane glycoprotein belonging to the immunoglobulin superfamily. Chicken Bsg (HT7/neurothelin/ 5A11) is expressed in neuroblasts, but disappears from neurons after a specific stage of cytodifferentiation, and becomes restrictedly expressed in the capillary endothelium in the adult brain. We show herein by means of in situ hybridization that Bsg mRNA was expressed in neuroblasts in 13.5 day old mouse embryos. In the adult mouse, Bsg was differentially expressed in subregions of the brain. Strong Bsg expression was detected in the limbic system, including the olfactory system, hippocampal formation, septal area, amygdala, thalamic anterior nuclei, hypothalamus, mesencephalic tegmentum, entorhinal cortex, and cingulate gyrus. Bsg was also intensely expressed in the retinal neuronal layers, the Vth layer of the cerebral neocortex, Purkinje cells of the cerebellum, several nuclei of the brain stem, and the gray matter of the spinal cord. Although in situ hybridization showed a weak signal in the brain capillary endothelium, protein expression of Bsg was strong enough to be detected by immunohistochemistry. Northern blot analysis confirmed the strong expression of Bsg in the central nervous system. Taking into account that Bsg knockout mice exhibit abnormalities in behavior, but a normal blood-brain barrier function, the present findings suggest that Bsg functions actively in neuronal interactions in the central nervous system.

Abnormalities of sensory and memory functions in mice lacking Bsg gene

Basigin is a highly glycosylated transmembrane protein belonging to the immunoglobulin superfamily. We used mutant mice lacking the basigin gene (Bsg) to investigate its involvement in learning and memory. Mutations were generated by the gene targeting method. Various kinds of learning and memory tasks were performed in mutant, hetero and wild type mice. The mutant mice showed worse performance than the wild and hetero mice in the Y-maze task, which assesses short-term memory, and in the water finding task, which examines latent learning, without any motor dysfunction. Moreover, the mutant mice showed less acclimation in the habituation task compared with the wild-type mice. The mutant mice were also more sensitive to electric foot-shock. These findings are consistent with the expression profile of basigin in the central nervous system. Thus, basigin may play an important role in learning and memory as well as in the sensory functions.

Midkine induces the transformation of NIH3T3 cells

Midkine (MK) is a heparin-binding growth factor and is frequently expressed at high levels in many human carcinomas. To investigate further the roles of MK in the regulation of cell growth, we introduced MK expression in NIH3T3 cells. A mixture of transfectants of an MK expression vector, but not a control vector, formed colonies in soft agar, showed an elevated cell number at confluence, and formed tumours in nude mice. An interesting characteristic of the transformed cells was that they became spontaneously detached from the culture dish substratum. In the transformed cells, MK was not only secreted, but also localized, in the perinuclear region as spots. The present data indicate that MK has the potential to transform NIH3T3 cells and suggest that overexpression of the MK gene may promote unregulated cell growth in vivo.

Restricted expression of Xenopus midkine gene during early development

Midkine (MK) is a heparin-binding growth factor and forms a novel protein family together with another member, pleiotrophin (PTN)/heparin-binding growth-associated molecule (HB-GAM). A cDNA clone isolated from Xenopus laevis specifies for the Xenopus counterpart of MK (XMK), and the mode of XMK expression was studied by in situ hybridization and Northern blot analysis. XMK was first expressed at stage 11 (middle gastrula) and was located in the neural anlage at stage 12 (late gastrula). Through stage 13 to 15 (early neurula), XMK expression was restricted to the neural folds. At stage 23 (tailbud stage), XMK was predominantly localized in the brain and neural tube. At the larva stage, XMK expression was again restrictedly observed in the brain, the optic vesicles, the otic vesicle, and the spinal cord, all of which are derivatives of the neural tube, as well as in the branchial arches, derivatives of the cranial neural crest. Comparing the mode of MK expression between Xenopus and the mouse, we propose that MK plays evolutionally conserved roles in neurogenesis and development of the craniofacial architecture of ectomesenchymal origin. We also found that XMK was expressed in various adult organs; strong expression was observed in the brain, the eye and the spinal cord, all of which showed intense MK expression at the larva stage.