[Risk factors analysis of protein energy wasting in children with chronic kidney disease]

Objective: To analyze the clinical characteristics and risk factors of protein energy wasting (PEW) in children with chronic kidney disease (CKD). Methods: Clinical data of 231 children with chronic kidney disease hospitalized in Beijing Children's Hospital affiliated to Capital Medical University from January 2018 to January 2023 were retrospectively analyzed to explore the incidence of PEW. According to the diagnostic criteria of CKDPEW, they were divided into a CKDPEW group and a non PEW group. The comparison between the groups was performed by independent-sample t test and Chi-squared test, and the risk factors were analyzed by multivariate Logistic regression. Results: Among the 231 children, there were 138 males and 93 females, with a visiting age of 9.9 (7.9, 16.0) years; 6 cases were in stage 1, 14 cases in stage 2, 51 cases in stage 3, 36 cases in stage 4, and 124 cases in stage 5. A total of 30 children (13.0%) with CKD PEW were diagnosed at the age of 7. 1 (3.8, 13.2) years, including 1 case in stage 1, 1 case in stage 2, 5 cases in stage 3, 5 cases in stage 4, and 18 cases in stage 5. There were a total of 201 cases (87.0%) in the non PEW group, diagnosed at the age of 11.8 (8.5, 12.2) years, including 5 cases in stage 1, 13 cases in stage 2, 46 cases in stage 3, 31 cases in stage 4, and 106 cases in stage 5. The Chi-squared test and t test showed that the systolic blood pressure, diastolic blood pressure, birth weight and carbon dioxide binding capacity of the CKD PEW group were lower than those of the non PEW group ((109±22) vs. (120±20) mmHg (1 mmHg=0.133 kPa), (72±19) vs. (79±16) mmHg, (2.9±0.5) vs. (3.2±0.6) kg, (17±4) vs. (19±4) mmol/L,t=2.85, 2.14, 0.67, 2.63, all P<0.05). Multivariate logistic regression analysis showed that carbon dioxide binding capacity and birth weight were independent protective factors of CKDPEW in children (OR=0.81 and 0.36, 95%CI=0.73-0.90 and 0.17-0.77, respectively; both P<0.01); the risk of PEW in CKD children decreased by 0.187 times for every 1 mmol/L increment in carbon dioxide binding capacity, and 0.638 times for every 1 kg increment in birth weight. Conclusions: The incidence of protein energy expenditure in children with chronic kidney disease is lower than that in the previous researches. PEW can appear in CKD 1-2 stage, and attention should be paid to it in the early stage of CKD in clinical practice. Low birth weight CKD children are susceptible to PEW, and actively correcting metabolic acidosis can reduce the risk of CKDPEW.

Lateral retraction could achieve better early postoperative knee function than patellar eversion in total knee arthroplasty: a systematic review and meta-analysis

OBJECTIVE

Comparisons between patellar eversion (PE) and lateral retraction (LR) in total knee arthroplasty (TKA) are still inconclusive. To determine the most suitable procedure, we aimed to evaluate the safety and efficacy of PE and LR in TKA in this meta-analysis.

MATERIALS AND METHODS

This meta-analysis complied with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Web-based literature databases, including WANFANG, VIP, CNKI, the Cochrane Library, Embase, and PubMed, were utilized to conduct a comprehensive literature search for studies published until June 2022 that compared PE with LR in primary TKA. The quality of the selected randomized controlled trials (RCTs) was evaluated using guidelines of the Cochrane Reviews Handbook 5.0.2.

RESULTS

A total of 10 RCTs, including 782 patients and 823 TKAs, were selected in this meta-analysis. Our results showed that using LR improved postoperative knee extensor function and range of motion (ROM). In addition, PE and LR resulted in similar clinical benefits in terms of Knee Society Function score, pain, length of hospital stay, Insall-Salvati ratio, the occurrence of patella baja, and complications related to the operation.

CONCLUSIONS

Existing evidence suggested that using LR in TKA improved early postoperative knee function. Similar clinical and radiographic outcomes were obtained 1 year after the procedures were performed. Based on these findings, we recommended the use of LR in TKA. However, studies with large sample sizes are needed to validate these findings.

Aetiology of tinea capitis in China: A multicentre prospective study

BACKGROUND

Tinea capitis is still common in developing countries, such as China. Its pathogen spectrum varies across regions and changes over time.

OBJECTIVES

This study aimed to clarify the current epidemiological characteristics and pathogen spectrum of tinea capitis in China.

METHODS

A multicentre, prospective descriptive study involving 29 tertiary hospitals in China was conducted. From August 2019 to July 2020, 611 patients with tinea capitis were enrolled. Data concerning demography, risk factors and fungal tests were collected. The pathogens were further identified by morphology or molecular sequencing when necessary in the central laboratory.

RESULTS

Among all enrolled patients, 74.1% of the cases were 2- to 8-year-olds. The children with tinea capitis were mainly boys (56.2%) and more likely to have an animal contact history (57.4% vs. 35.3%, P = 0.012) and zoophilic dermatophyte infection (73.5%). The adults were mainly females (83.3%) and more likely to have anthropophilic agent infection (53.5%). The most common pathogen was zoophilic Microsporum canis (354, 65.2%), followed by anthropophilic Trichophyton violaceum (74, 13.6%). In contrast to the eastern, western and northeastern regions where zoophilic M. canis predominated, anthropophilic T. violaceum predominated in central China (69.2%, P < 0.0001), where the patients had the most tinea at other sites (20.3%) and dermatophytosis contact (25.9%) with the least animal contact (38.8%). Microsporum ferrugineum was the most common anthropophilic agent in the western area, especially in Xinjiang Province.

CONCLUSIONS

Boys aged approximately 5 years were mainly affected. Dermatologists are advised to pay more attention to the different transmission routes and pathogen spectra in different age groups from different regions.

Oral immunization with a Lactobacillus casei-based anti-porcine epidemic diarrhoea virus (PEDV) vaccine expressing microfold cell-targeting peptide Co1 fused with the COE antigen of PEDV

AIMS

The aims of this study were to develop an effective M cell-targeting oral vaccine, involving Lactobacillus casei to deliver the porcine epidemic diarrhoea virus (PEDV) core neutralizing epitope (COE) antigen conjugated with M cell-targeting peptide Co1 as an adjuvant, against PEDV infection.

METHODS AND RESULTS

Genetically engineered L. casei 393 (L393) strains expressing PEDV COE antigen only (pPG-COE/L393) or fused-expressing COE and M cell-targeting peptide Co1 (pPG-COE-Co1/L393) were constructed, and the immunogenicity upon administration as an oral vaccine was evaluated. The results showed that higher anti-PEDV serum IgG and mucosal SIgA antibody responses were induced in mice orally immunized with strain pPG-COE-Co1/L393 as compared to the mice immunized with strain L393 expressing COE alone or carrying the empty plasmid. In addition, the use of the Co1 ligand elicited a splenocyte proliferative response more effectively in comparison with the COE antigen alone and supported a skewed T helper 2 type of immune response against PEDV.

CONCLUSIONS

pPG-COE-Co1/L393 can effectively induce mucosal, humoural and Th2-type cellular immune responses against PEDV infection via oral administration. Furthermore, M cell-targeting peptide ligand Co1 is a good mucosal adjuvant.

SIGNIFICANCE AND IMPACT OF THE STUDY

Lactobacillus casei delivering the COE antigen of PEDV conjugated with a M cell-targeting peptide Co1 as an immune adjuvant is a promising oral vaccine candidate for PEDV.

The nuclear hormone receptor E75A regulates vitellogenin gene (Al-Vg) expression in the mirid bug Apolygus lucorum

Apolygus lucorum is the predominant pest of Bacillus thuringiensis (Bt) cotton in China. 20-hydroxyecdysone (20E) plays a key role in the reproduction of this insect. To better understand the mechanism underlying 20E-regulated reproduction, the nuclear hormone receptor E75 isoform-A of Ap. lucorum (Al-E75A) was cloned and its expression analysed. A 2241-bp sequence of Al-E75A cDNA encoded an open reading frame of a polypeptide with a predicted molecular mass of 69.04 kDa. Al-E75A mRNA was detected in female adult stages of Ap. lucorum with peak expression in 7-day-old animals. Al-E75A was also expressed in several tissues, particularly in the fat body and ovary. A 3.2 kb Al-E75A mRNA was detected in all tissues by Northern blot. The fecundity and longevity were significantly decreased in female adults treated with Al-E75A small interfering RNA. The rates of egg incubation rates were considerably lower in the RNA interference-treated animals compared to the untreated controls. In order to investigate the molecular mechanism underlying the effects described above, vitellogenin (Al-Vg) was selected for further investigation. The expression pattern of Al-Vg was similar to that of Al-E75A and was up-regulated by 20E. After knockdown of Al-E75A, the expression profile of Al-Vg and the protein levels were down-regulated. These findings suggest that Al-E75A plays a crucial role in the regulation of Al-Vg expression in Ap. lucorum.

Analysis of the genome sequence of infectious hematopoietic necrosis virus HLJ-09 in China

Infectious hematopoietic necrosis virus (IHNV) is a highly contagious disease of juvenile salmonid fish. Six genome target fragments of the complete genome sequence of IHNV HLJ-09 were amplified by RT-PCR, and the 3'-terminal and 5'-terminal region of the genomic RNA were amplified using the RACE method. The complete genome sequence of HLJ-09 comprises 11,132 nucleotides (nt) (Accession number JX649101) and is different from that of other IHNV strains published in GenBank. Homology comparison and phylogenetic analysis of six ORF sequences were carried out using HLJ-09 and other IHNV strains published in GenBank. From phylogenetic tree analysis, the N gene, M gene, and P gene had the closest genetic relationship to IHNV-PRT from Korea. Phylogenetic analysis for the full length of the G gene showed that the HLJ-09 strain exhibited very close homology to the ChYa07, RtNag96, RtUi02, and RtGu01 strains from Korea and Japan, indicating that the HLJ-09 strain belonged to the genotype JRt. Ultimately, the Chinese IHNV HLJ-09 strain may have originated in Korea and Japan.

Development of a DNA microarray-based multiplex assay of avian influenza virus subtypes H5, H7, H9, N1, and N2

Outbreaks of highly pathogenic avian influenza have caused considerable economic losses in the poultry industry and have also resulted in human deaths since 2004. Rapid subtyping of highly pathogenic avian influenza viruses(HPAIVs) in clinical specimens is a prerequisite of prompt control of disease and prevention of its spreading. In this study, we describe development of a DNA microarray-based detection and subtyping of HPAIVs in field samples. DNA copies of matrix (M) protein genes for the H5, H7, and H9 subtypes of hemagglutinin (HA) and the N1 and N2 subtypes of neuraminidase (NA) were prepared by RT-PCR and specific primers and then spotted onto aldehyde slides to form DNA microarrays. The HPAIV samples to be tested were subjected to total RNA isolation, RT-PCR with universal primers and Cy3 labeling, and the obtained double-stranded DNAs (targets) were finally hybridized with DNA microarrays (probes). A fluorescent spot on the microarray, detected by scanning indicated positive hybridization, i.e. the involved subtype. The assay was specific as various heterologous viruses or HPAIVs of other subtypes tested were negative. No cross-hybridization among different subtypes could be detected. The assay was more sensitive than RT-PCR and chicken embryo inoculation and could be also used for field samples. Summing up, the assay has proved useful for simultaneous detection and differentiation of main epidemic HPAIV subtypes.

In vivo analysis of kallikrein-related peptidase 6 (KLK6) function in oligodendrocyte development and the expression of myelin proteins

Oligodendrocytes are important for not only nerve conduction but also central nervous system (CNS) development and neuronal survival in a variety of conditions. Kallikrein-related peptidase 6 (KLK6) is expressed in oligodendrocytes in the CNS and its expression is changed in several physiological and pathological conditions, especially following spinal cord injury (SCI) and experimental autoimmune encephalomyelitis. In this study, we investigated the functions of KLK6 in oligodendrocyte lineage cell development and the production of myelin proteins using KLK6-deficient (KLK6(-/-)) mice. KLK6(-/-) mice were born without apparent defects and lived as long as wild-type (WT) mice. There was no significant difference in the numbers of oligodendrocyte precursor cells and mature oligodendrocytes in the adult naive spinal cord between WT and KLK6(-/-) mice. However, there were fewer mature oligodendrocytes in the KLK6(-/-) spinal cord than in the WT spinal cord at postnatal day 7 (P7). Expression of myelin basic protein (MBP) and oligodendrocyte-specific protein/claudin-11, major myelin proteins, was also decreased in the KLK6(-/-) spinal cord compared with the WT spinal cord at P7-21. Moreover, after SCI, the amount of MBP in the damaged spinal cords of KLK6(-/-) mice was significantly less than that in the damaged spinal cords of WT mice. These results indicate that KLK6 plays a functional role in oligodendrocyte development and the expression of myelin proteins.

Cerebral magnetic resonance imaging of compressed air divers in diving accidents

To investigate the characteristics of the cerebral magnetic resonance imaging (MRI) of compressed air divers in diving accidents, we conducted an observational case series study. MRI of brain were examined and analysed on seven cases compressed air divers complicated with cerebral arterial gas embolism CAGE. There were some characteristics of cerebral injury: (1) Multiple lesions; (2) larger size; (3) Susceptible to parietal and frontal lobe; (4) Both cortical grey matter and subcortical white matter can be affected; (5) Cerebellum is also the target of air embolism. The MRI of brain is an sensitive method for detecting cerebral lesions in compressed air divers in diving accidents. The MRI should be finished on divers in diving accidents within 5 days.

99mTc-TRODAT-1 SPECT study in early Parkinson's disease and essential tremor

OBJECTIVE

The clinical differentiation between early Parkinson's disease (PD) and essential tremor (ET) could be difficult, therefore, the aim of this study was to investigate 99mTc-TRODAT-1 SPECT as an applicable tool in this field.

METHODS

99mTc-TRODAT-1 single photon emission computed tomography (SPECT) was performed in 10 healthy volunteers, 27 patients with idiopathic PD (Hoehn and Yahr 1-1.5) and 12 patients with ET. The ratio of striatal (99m)Tc-TRODAT-1 binding was calculated as the index of (striatum - occipital cortex)/occipital cortex.

RESULTS

Compared with the striatal 99mTc-TRODAT-1 uptake in the ET group (0.49 +/- 0.07) or healthy controls (0.54 +/- 0.18), there was a significant decrease in the bilateral striatums of early PD, with a greater reduction in the contralateral striatum (0.27 +/- 0.08) than ipsilateral one (0.36 +/- 0.10, P < 0.01). Its sensitivity and specificity of differentiating early PD from ET was 96.4% and 91.7% respectively.

CONCLUSION

99mTc-TRODAT-1 SPECT can detect the dysfunction of nigrostriatal system in patients with early PD and provided a feasible tool to help differentiate early PD from ET.

Dual regulation of glycogen synthase kinase-3beta by the alpha1A-adrenergic receptor

Catecholamines, acting through adrenergic receptors, play an important role in modulating the effects of insulin on glucose metabolism. Insulin activation of glycogen synthesis is mediated in part by the inhibitory phosphorylation of glycogen synthase kinase-3 (GSK-3). In this study, catecholamine regulation of GSK-3beta was investigated in Rat-1 fibroblasts stably expressing the alpha1A-adrenergic receptor. Treatment of these cells with either insulin or phenylephrine (PE), an alpha1-adrenergic receptor agonist, induced Ser-9 phosphorylation of GSK-3beta and inhibited GSK-3beta activity. Insulin-induced GSK-3beta phosphorylation is mediated by the phosphatidylinositol 3-kinase/Akt signaling pathway. PE treatment does not activate phosphatidylinositol 3-kinase or Akt (Ballou, L. M., Cross, M. E., Huang, S., McReynolds, E. M., Zhang, B. X., and Lin, R. Z. (2000) J. Biol. Chem. 275, 4803-4809), but instead inhibits insulin-induced Akt activation and GSK-3beta phosphorylation. Experiments using protein kinase C (PKC) inhibitors suggest that phorbol ester-sensitive novel PKC and Gö 6983-sensitive atypical PKC isoforms are involved in the PE-induced phosphorylation of GSK-3beta. Indeed, PE treatment of Rat-1 cells increased the activity of atypical PKCzeta, and expression of PKCzeta in COS-7 cells stimulated GSK-3beta Ser-9 phosphorylation. In addition, PE-induced GSK-3beta phosphorylation was reduced in Rat-1 cells treated with a cell-permeable PKCzeta pseudosubstrate peptide inhibitor. These results suggest that the alpha1A-adrenergic receptor regulates GSK-3beta through two signaling pathways. One pathway inhibits insulin-induced GSK-3beta phosphorylation by blocking insulin activation of Akt. The second pathway stimulates Ser-9 phosphorylation of GSK-3beta, probably via PKC.

[Triterpenoid saponins from Eclipta prostrata L]

AIM

To study the triterpenoid saponins in the Chinese traditional medicine Eclipta prostrata L..

METHODS

Column chromatography with silica gel and HPLC were employed for the isolation and purification. The molecular structures were determined on the basis of spectral analysis (IR, MS, 1HNMR, 13CNMR, HMQC and HMBC).

RESULTS

Two new triterpenoid saponins, named eclalbasaponins XI (4) and XII (5), were obtained and their structures were elucidated as 3-O-[beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl]-16 alpha-ethoxy-olean-12-ene-28-oic acid-28-O-beta-D-glucopyranoside and 3-O-[(2-O-sulfuryl-beta-D-glucopyranosyl) (1-->2)-beta-D-glucopyranosyl]-echinocystic acid-28-O-beta-D-glucopyranoside, respectively, along with three known saponins, eclalbasaponins II (1), I (2) and III (3).

CONCLUSION

Compounds 4 and 5 are new compounds, 1 and 5 induced morphological deformation of Pyricularia oryzae mycelia.

Rapamycin-insensitive regulation of 4e-BP1 in regenerating rat liver

In cultured cells, growth factor-induced phosphorylation of two translation modulators, p70 S6 kinase and eukaryotic initiation factor 4E-binding protein 1 (4E-BP1), is blocked by nanomolar concentrations of the immunosuppressant rapamycin. Rapamycin also attenuates liver regeneration after partial hepatectomy, but it is not known if this growth-suppressive effect is due to dephosphorylation of p70 S6 kinase and/or 4E-BP1. We found that partial hepatectomy induced a transient increase in liver p70 S6 kinase activity and 4E-BP1 phosphorylation as compared with sham-operated rats. The amount of p70 S6 kinase protein in regenerating liver did not increase, but active kinase from partially hepatectomized animals was highly phosphorylated. Phosphorylated 4E-BP1 from regenerating liver was unable to form an inhibitory complex with initiation factor 4E. Rapamycin blocked the activation of p70 S6 kinase in response to partial hepatectomy in a dose-dependent manner, but 4E-BP1 phosphorylation was not inhibited. By contrast, functional phosphorylation of 4E-BP1 induced by injection of cycloheximide or growth factors was partially reversed by the drug. The mammalian target of rapamycin (mTOR) has been proposed to directly phosphorylate 4E-BP1. Western blot analysis using phospho-specific antibodies showed that phosphorylation of Thr-36/45 and Ser-64 increased in response to partial hepatectomy in a rapamycin-resistant manner. Thus, rapamycin inhibits p70 S6 kinase activation and liver regeneration, but not functional phosphorylation of 4E-BP1, in response to partial hepatectomy. These results indicate that the effect of rapamycin on 4E-BP1 function in vivo can be significantly different from its effect in cultured cells.

Studying the growth of cervical carcinoma nests and angiogenesis by immunostaining, quantitation and three-dimensional structural analysis

OBJECTIVE

To analyze the relationship and mutual effect of the growth of cervical carcinoma nests and angiogenesis.

STUDY DESIGN

Serial paraffin sections of cervical squamous carcinoma were stained in repeated order with hematoxylin-eosin (HE), immunostain for factor VIII-related antigen, type IV collagen and proliferating cell nuclear antigen (PCNA). Three-dimensional reconstructions were made, and the volumes of carcinoma nests, necrosis and microvessels were measured.

RESULTS

Two types of cervical carcinoma nests were distinguished on the basis of their growth characteristics and vascularity (groups I and II). Group I nests: The carcinoma cells were proliferating actively, as determined by their morphology and PCNA staining. There were abundant microvessels. Some endothelial sprouts and cords penetrated the nests and then formed networks and new vessels. The volume ratio of microvessels, including sprouts and cords, to the nests was 0.6282:1. Group II nests: The center of these nests underwent necrosis. The peripheral cells were rather small, with no mitosis. The PCNA index was rather low; these nests grew very slowly. There were only a few surrounding microvessels with no endothelial sprouts or cords. The volume ratio of vessels to nest was 0.0657:1.

CONCLUSION

Two types of cervical carcinoma nests show a close relationship and mutual effect of the growth of carcinoma nest and angiogenesis. Group I nests grow and develop well, with abundant microvessels. Thus, many tumor cells may be angiogenic and induce angiogenesis; growth of the nests seemed dependent on adequate neovascularization. Group II nests grow slowly, with a few microvessels; the center of the nests undergoes necrosis. The inadequate blood supply must be one of the important causes of necrosis. Considering that there must have been abundant neovascularization during their growth in the past, most of the microvessels must have been obliterated and then reabsorbed to make the remaining vessels so few.

[Oleanolic acid saponins from the root bark of Aralia taibaiensis]

Five oleanolic acid saponins were isolated from the root bark of Aralia taibaiensis Z.Z. Wang et H.C. Zheng. By spectroscopic and chemical methods, they were identified as araloside A (1), 3-O-[alpha-L-arabinofuranosyl(1-->4)-6'-O-n-butyl-beta-D- glucuronopyranosyl]-oleanolic acid-28-O-beta-D-glucopyranoside (2), 3-O-[alpha-L-arabinofuranosyl(1-->4)-6'-O-ethyl-beta-D- glucuronopyra-nosyl]-oleanolic acid-28-O-beta-D-glucopyranoside (3), stipuleanoside R2(4) and 3-O-(beta-D-glucopyranosyl(1-->3) [alpha-L-arabinofuranosyl(1-->4)]-6'-O-ethyl-beta-D- glucuronopyranosyl)-oleanolic acid-28-O-beta-D-glucopyranoside (5). Saponin 1 and 4 were isolated from the title plant for the first time. 2, 3 and 5 are new compounds and named taibaienoside I, taibaienoside II and taibaienoside III, respectively.

[Effect of sijunzi decoction on motilin and pharmacokinetic characteristics of tetramethylpyrazine in rat model of spleen deficiency syndrome]

OBJECTIVE

To explore relationship between the essence of Spleen Deficiency Syndrome (SDS) and pharmacokinetic characteristics (PK).

METHODS

The level of motilin in serum and intestine, and PK of tetramethylpyrazine phosphate (TMPP) in rat model of SDS were observed simultaneously and treated with Sijunzi decoction (SJZD) for confirmation.

RESULTS

The atrioventricular model of TMPP in SDS, normal and SJZD treated rats all belonged to the open double ventricular type; there were insignificant differences between normal and SJZD treated rats in motilin level and PK of TMPP, but the differences of these parameters between normal and SDS model rats were significantly (P < 0.01). The SDS state could markedly affect the absorption, distribution, metabolism and elimination of TMPP in rat; SJZD could normalize the abnormal PK of TMPP in SDS model rats.

CONCLUSIONS

A supplementary scientific evidence for the hypothesis of "Pharmacokinetics of Syndrome Differentiation" is provided.

A death-domain-containing receptor that mediates apoptosis

The cell-killing effects of the cytokines TNF-alpha and FasL are mediated by the distinct cell-surface receptors TNFR1, TNFR2 and Fas (also known as CD95/APO-1), which are all members of a receptor superfamily that is important for regulating cell survival. The cytoplasmic regions of TNFR1 and Fas contain a conserved 'death' domain which is an essential component of the signal pathway that triggers apoptosis and activation of the transcription factor NF-kappaB (refs 5,6). Here we report the isolation of a 54K receptor that is a new member of the TNFR superfamily, using the death domain of TNFR1 in a yeast two-hybrid system. This protein, WSL-1, is most similar to TNFR1 itself, particularly in the death-domain region. The gene wsl-1 is capable of inducing apoptosis when transfected into 3T3 and 293 cells, and can also activate NF-kappaB in 293 cells. Like TNFR1, WSL-1 will homodimerize in yeast. WSL-1 also interacts specifically with the TNFR1-associated molecule TRADD. The tissue distribution is very restricted and significantly different from that of Fas and TNFR1.

Effects of HI-6 on muscle acetylcholine receptor: analysis on minimal reaction model

AIM

To study the action of 1-(2-hydroxyiminomethyl-1-pyridino)-3-(4-carbamoyl-1-pyridino)-2-oxapropane dichloride (HI-6) on skeletal muscle acetylcholine receptor (N2-ChR).

METHODS

N2-ChR was expressed in Xenopus laevis oocyte after injection with mRNA extracted from denervated rat leg muscles. The inward membrane currents induced by various concentrations of carbamylcholine and effects of HI-6 or d-tubocurarine on the currents were measured with voltage clamp technique by fast cell flow of agents. The actions of HI-6 and d-tubocurarine on N2-ChR were analyzed by using the minimal reaction model.

RESULTS

K of 40.05, 156.00, and 334.67 mumol.L-1 for HI-6, K of 0.02, 0.10, and 0.18 mumol.L-1 for d-tubocurarine were obtained by using the competing for single acetylcholine (ACh)-binding site model, the competing for two ACh-binding sites model, and the noncompetitive inhibition model, respectively.

CONCLUSION

HI-6 and d-tubocurarine competed for two ACh-binding sites of N2-ChR with equal affinity to antagonize the effects of the agonist on N2-ChR. The N2-ChR inhibition by HI-6 is much weaker than that by d-tubocurarine.

[Study on pharmacokinetic characteristics of tetramethylpyrazine and hemodynamics of heart blood stasis in dogs]

"Blood stasis syndrome pharmacokinetics" means the pathophysiological state of blood stasis syndrome affectes significantly the pharmacokinetic parameters. In order to provide scientific evidence for the new hypothesis, the authors studied the hemodynamic changes induced by quantitative coronary artery stenosis and pharmacokinetics of tetramethylpyrazine (TMP) in dog model with heart blood stasis (HBS) and in normal dog (for control) simultaneously. Compared with healthy dog, serum TMP concentration, drug concentration time, area under curve (AUC) and t1/2 beta in HBS dog were increased significantly (P < 0.01). The mechanism might be related with the abnormal changes in hemodynamics (indude decrease in cardiac output, left ventricular systolic pressure and coronary blood flow, etc.) caused by coronary artery stenosis.

Homophilic interactions mediated by receptor tyrosine phosphatases mu and kappa. A critical role for the novel extracellular MAM domain

The receptor-like protein tyrosine phosphatases (RPTP) mu and RPTP kappa have a modular ectodomain consisting of four fibronectin type III-like repeats, a single Ig-like domain, and a newly identified N-terminal MAM domain. The function of the latter module, which comprises about 160 amino acids and is found in diverse transmembrane proteins, is not known. We previously reported that both RPTP mu and RPTP kappa can mediate homophilic cell interactions when expressed in insect cells. Here we show that despite their striking structural similarity, RPTP mu and RPTP kappa fail to interact in a heterophilic manner. To examine the role of the MAM domain in homophilic binding, we expressed a mutant RPTP mu lacking the MAM domain in insect Sf9 cells. Truncated RPTP mu is properly expressed at the cell surface but fails to promote cell-cell adhesion. Homophilic cell adhesion is fully restored in a chimeric RPTP mu molecule containing the MAM domain of RPTP kappa. However, this chimeric RPTP mu does not interact with either RPTP mu or RPTP kappa. These results indicate that the MAM domain of RPTP mu and RPTP kappa is essential for homophilic cell-cell interaction and helps determine the specificity of these interactions.

[Protective effects of ginsenoside on myocardiac ischemic and reperfusion injuries]

Thirty mitral valvular surgical patients were randomly divided into three groups for study of protective effects of Ginsenoside on myocardiac ischemic and reperfusion injuries. In GI, 11 patients (controls), no Ginsenoside was used, in GII, 11, Ginsenoside in total was added into the cardioplegic solusion made in our hospital, and in GIII, 8, instead of Ginsenoside in total Ginsenoside Rb was added. During operation comparative studies were made of pre- and postoperative cardiac functions with intraoperative transesophageal echocardiography and ultrastructures of myocardiac cells with electromicroscopy. We conclude that both Ginsenoside in total and Ginsenoside Rb have protective effects on myocardiac ischemic and reperfusion injuries in open heart surgery, and the effect of Ginsenoside in total is even better than that of Ginsenoside Rb.

Inhibition of sympathetic neurotransmission via NEM-sensitive H3-receptors in the guinea pig vas deferens

The influence of N-ethylmaleimide (NEM) on sympathetic neurotransmission induced by field stimulation on the isolated guinea pig vas deferens was studied. Application of (R)-alpha-methylhistamine (0.1 mcmol/l) significantly inhibited the sympathetic response by 26.0%, while thioperamide facilitated the sympathetic contraction of vas deferens evoked by field pulses by 221.1%. Pretreatment of vas deferens with NEM (60 mcmol/l) for 15 min abolished both the inhibitory and facilitatory effects. Attenuation of thioperamide facilitatory effect by NEM was not significantly altered when the H3-receptors were occupied by thioperamide prior to and during NEM treatment. The results suggest that effects mediated by H3-receptors in the guinea pig vas deferens were NEM-sensitive and possibly transmitted by Gi or Go proteins.

Receptor tyrosine phosphatase R-PTP-kappa mediates homophilic binding

Receptor tyrosine phosphatases (R-PTPases) feature PTPase domains in the context of a receptor-like transmembrane topology. The R-PTPase R-PTP-kappa displays an extracellular domain composed of fibronectin type III motifs, a single immunoglobulin domain, as well as a recently defined MAM domain (Y.-P. Jiang, H. Wang, P. D'Eustachio, J.M. Musacchio, J. Schlessinger, and J. Sap, Mol. Cell. Biol. 13:2942-2951, 1993). We report here that R-PTP-kappa can mediate homophilic intercellular interaction. Inducible expression of the R-PTP-kappa protein in heterologous cells results in formation of stable cellular aggregates strictly consisting of R-PTP-kappa-expressing cells. Moreover, the purified extracellular domain of R-PTP-kappa functions as a substrate for adhesion by cells expressing R-PTP-kappa and induces aggregation of coated synthetic beads. R-PTP-kappa-mediated intercellular adhesion does not require PTPase activity or posttranslational proteolytic cleavage of the R-PTP-kappa protein and is calcium independent. The results suggest that R-PTPases may provide a link between cell-cell contact and cellular signaling events involving tyrosine phosphorylation.

[Changes in oxygen free radical and prostacyclin in thromboangiitis obliterans and its relationship with syndrome differentiation]

Malondialdehyde (MDA) and 6-keto-PGF1 alpha levels in plasma and erythrocyte superoxide dismutase activities (Ery-SODA) were observed in 56 cases of thromboangiitis obliterans (TAO). The results showed that: (1) Ery-SODA and 6-keto-PGF1 alpha levels lowered and MDA raised significantly in TAO (P < 0.01), compared with that in control. (2) 6-keto-PGF1 alpha levels were markedly related with Ery-SODA and MDA in TAO (P < 0.01). (3) Ery-SODA and 6-keto-PGF1 alpha levels were lower and MDA higher in III phase of TAO than that in II phase. (4) Ery-SODA and 6-keto-PGF1 alpha levels markedly declined and MDA contents elevated significantly in Dampness-Heat (DH) and Heat-Toxin (HT) group, compared with that in Yin-Cold (YC) group and Blood-Stasis (BS) group, respectively (P < 0.05, P < 0.01); all above substances between YC and BS group or between DH and HT group had no significant differences (P > 0.05). (5) Ery-SODA and 6-keto-PGF1 alpha levels were lower and MDA higher in Heat Syndrome than that in Cold Syndrome (P < 0.01). It suggested that oxygen free radical and lipid peroxide response that might participate in vascular endothelial cell injury in TAO markedly increased and the detection of these substances might provide complementary evidences for syndrome differentiation of TAO.

Cloning and characterization of R-PTP-kappa, a new member of the receptor protein tyrosine phosphatase family with a proteolytically cleaved cellular adhesion molecule-like extracellular region

We describe a new member of the receptor protein tyrosine phosphatase family, R-PTP-kappa, cDNA cloning predicts that R-PTP-kappa is synthesized from a precursor protein of 1,457 amino acids. Its intracellular domain displays the classical tandemly repeated protein tyrosine phosphatase homology, separated from the transmembrane segment by an uncharacteristically large juxta-membrane region. The extracellular domain of the R-PTP-kappa precursor protein contains an immunoglobulin-like domain and four fibronectin type III-like repeats, preceded by a signal peptide and a region of about 150 amino acids with similarity to the Xenopus A5 antigen, a putative neuronal recognition molecule (S. Takagi, T. Hsrata, K. Agata, M. Mochii, G. Eguchi, and H. Fujisawa, Neuron 7:295-307, 1991). Antibodies directed against the intra- and extracellular domains reveal that the R-PTP-kappa precursor protein undergoes proteolytic processing, following which both cleavage products remain associated. By site-directed mutagenesis, the likely cleavage site was shown to be a consensus sequence for cleavage by the processing endopeptidase furin, located in the fourth fibronectin type III-like repeat. In situ hybridization analysis indicates that expression of R-PTP-kappa in the central nervous system is developmentally regulated, with highest expression seen in actively developing areas and, in the adult, in areas capable of developmental plasticity such as the hippocampal formation and cerebral cortex. The mouse R-PTP-kappa gene maps to chromosome 10, at approximately 21 centimorgans from the centromere.

PPACK-thrombin is a noncompetitive inhibitor of alpha-thrombin binding to human platelets

Recent studies from our laboratory indicate that purified kininogens are noncompetitive inhibitors of human alpha-thrombin but not PPACK-thrombin, binding to human washed platelets. In order to understand the mechanism by which the kininogens inhibit alpha-thrombin binding, investigations were initiated to determine if alpha-thrombin and PPACK-thrombin bound to the same site on human platelets. Initial investigations reveal that alpha-thrombin is a more potent inhibitor of 125I-PPACK-thrombin binding than PPACK-thrombin. Further studies show that PPACK-thrombin is a noncompetitive inhibitor of 125I-alpha-thrombin binding to platelets. These studies suggest that human alpha-thrombin binds on the platelet surface to a different site or binds differently to the same site from PPACK-thrombin. These data indicate that the ability of the kininogens to block alpha-thrombin binding to platelets but not PPACK-thrombin binding results from these thrombins having either two different binding sites or one binding site on the platelet surface which they interact with differently.

Domain 3 of kininogens contains a cell-binding site and a site that modifies thrombin activation of platelets

High and low molecular weight kininogens (HK and LK) are able to bind to platelets to inhibit thrombin binding to and activation of platelets. The heavy chain domain on the kininogens that contains these functions has been determined. Domain 3 (D3) but not domains 1 or 2, completely inhibited 125I-HK binding to platelets (Ki = 24 +/- 7 nM, n = 4). 125I-D3 specifically bound to unstimulated platelets and human umbilical vein endothelial cells. On platelets, it was blocked by unlabeled D3 and HK but not prekallikrein, factor XII, C1s, or C1 inhibitor. Further, one monoclonal antibody (HKH13) directed to kininogens' D3 blocked 125I-HK and 125I-D3 binding to platelets. The binding of 125I-D3 to platelets was fully reversible by addition of 35 molar excess of unlabeled D3. D3 binding to platelets was saturable with an apparent Kd of 39 +/- 8 nM (n = 4) and 1227 +/- 404 binding sites/platelet. D3, like HK and LK, inhibited thrombin-induced platelet activation by preventing thrombin binding to platelets. Another monoclonal antibody (HKH12), directed to D3, which did not block HK binding to platelets, reduced HK's ability to inhibit 125I-alpha-thrombin binding. This result suggests that the region on D3 that inhibits 125I-alpha-thrombin binding to platelets is different from that which directly binds to platelets. These studies indicate that D3 of the kininogens contains both a binding region for platelets and endothelial cells and another region that inhibits thrombin-induced platelet activation.

Characterization of cell binding and thrombin inhibitory regions on kininogens' heavy chain

Investigations have been performed to determine the domain(s) on kininogens' heavy chain that binds to platelets and contains thrombin inhibitory region Domain 3, but not domains 1 or 2, completely inhibited 125I-HK binding to platelets (Ki = 24 nM +/- 7, n = 4). D3 binding to platelets was saturable with an apparent Kd of 39 nM +/- 8 (n = 4) and 1227 +/- 404 binding sites/platelet. D3 inhibited 125I-thrombin binding to platelets which prevented thrombin-induced platelet aggregation and secretion. These studies indicate that D3 on kininogens' heavy chain contains a cell binding region and another region which inhibits thrombin binding and activation of platelets.

Cells secreting anti-MAG antibody occur in cerebrospinal fluid and bone marrow in patients with polyneuropathy associated with M component

Occurrence and distribution of cells secreting antibodies against myelin associated glycoprotein (MAG) were studied in 9 patients with polyneuropathy associated with the monoclonal (M) component in serum. Utilizing an immunospot assay, we found that 4 of 7 patients with polyneuropathy associated with an IgM M component had cells secreting anti-MAG IgM antibody in cerebrospinal fluid (CSF) numbering between 1 per 212 and 1 per 3333 mononuclear cells. All 7 patients had cells secreting anti-MAG IgM antibody in bone marrow (median value 1 per 2000 cells). In contrast, peripheral blood from only 2 of these patients contained low numbers of such cells. One patient with polyneuropathy associated with an IgA M component had cells secreting anti-MAG IgA antibody in CSF, and 1 with an IgG M component had cells secreting anti-MAG IgG antibody in CSF; both patients also had anti-MAG IgM antibodies detectable in CSF only by ELISA. These 2 patients may thus have concurrent intrathecal production of antibodies of 2 different isotypes which are directed against the same or different epitopes of MAG. The production of antibodies directed against a component of myelin occurring in the immediate vicinity of the peripheral nervous system might be involved in the pathogenesis of the polyneuropathy.

Antibodies to myelin-associated glycoprotein are found in cerebrospinal fluid in polyneuropathy associated with monoclonal serum IgM

Antibodies to myelin-associated glycoprotein (MAG) have been demonstrated in the serum samples from about half the patients with polyneuropathy associated with serum IgM monoclonal component. We examined cerebrospinal fluid (CSF) and serum samples from 13 patients with this disease by enzyme-linked immunosorbent assay for anti-MAG IgM antibodies. We detected these antibodies in both CSF and serum samples in 10 of the patients; in three of them the antibodies were at higher levels in the CSF. The remaining three patients had anti-MAG IgM antibodies in the CSF only. Intrathecal production of anti-MAG IgM antibodies is thus common in polyneuropathy associated with IgM monoclonal component. In three patients, examined on two occasions from 1 to 7 years, high anti-MAG IgM antibody levels persisted in CSF and serum samples. Among 165 patients with other neurologic diseases, including 60 with multiple sclerosis and 60 control subjects with tension headache, anti-MAG IgM antibodies were detected in the CSF from three patients (two with multiple sclerosis, one with aseptic meningitis), and in the serum sample of one patient with multiple sclerosis. Whether the frequent occurrence of anti-MAG IgM antibodies in CSF and their intrathecal synthesis has pathogenetic relevance for the development of polyneuropathy associated with IgM monoclonal component is unsure.

Autoreactive T lymphocytes in multiple sclerosis determined by antigen-induced secretion of interferon-gamma

Multiple sclerosis (MS) is a disease with unknown cause characterized by inflammation and demyelination in the central nervous system. Although an autoimmune pathogenesis has been suggested, there are no conclusive data on the number of T cells autoreactive with myelin antigens in MS compared to controls. We showed that T lymphocytes secreting interferon-gamma in response to possible target autoantigens are severalfold more common among PBL mononuclear cells in patients with MS than in patients with aseptic meningitis and tension headache. On average T cells reactive with myelin basic protein (MBP), two different MBP peptides, or with proteolipid protein amounted to 2.7-5.2/10(5) PBL from MS patients. MBP-reactive T cells were still more frequent among mononuclear cells isolated from the cerebrospinal fluid (CSF; 185/10(5) CSF cells). We concluded that T cells reactive with myelin autoantigens are strongly increased in MS. This approach to detect them could allow definition of immunodominant T cell epitopes in individual MS patients, and thereby enable further development towards specific immunotherapy.

Persistent anti-myelin basic protein IgG antibody response in multiple sclerosis cerebrospinal fluid

Antibodies to myelin components, such as myelin basic protein (MBP), may play a role in pathogenesis of multiple sclerosis (MS) but results from determinations of anti-MBP antibodies are inconsistent. Enumeration of cells secreting antibodies represents a new approach to evaluate a specific antibody response regarding extent and localization, and reduces effects of e.g. antibody binding to target. Anti-MBP IgG antibody secreting cells were present in MS patients' cerebrospinal fluid (CSF) at a mean value of 1 per 833 cells, and they amounted to a mean value of about 2454 in the whole CSF compartment. Similar numbers were encountered in patients with other inflammatory neurological diseases (OIND). During follow-up, anti-MBP IgG antibody secreting cells persisted regarding frequency and numbers in MS, but decreased in OIND. Such cells were rarely detected in patients with tension headache. No correlations to clinical exacerbation of MS, disability or duration were discernable. In blood from MS and OIND patients, anti-MBP IgG antibody secreting cells were detected infrequently and at low numbers. The anti-MBP antibody response is strongly restricted to the IgG isotype. The anti-MBP IgG antibody response which is persistent and compartmentalized to the diseased organ, may be important for the development of MS.

B cells and antibodies in MS

When the B-cell response was examined by enumeration of immunoglobulin (Ig)-secreting cells, normal cerebrospinal fluid (CSF)--in contrast to previous beliefs--contained IgG-secreting cells, indeed at an 8-fold higher proportion per 10(4) mononuclear cells (MNC) than blood. As expected, the proportion of IgG-producing cells was greatly increased in MS CSF. Evaluation of antibody (Ab) responses at the cellular level, thereby bypassing draw-backs inherent in determinations of circulating Ab levels, such as Ab binding to target, revealed that in one MS patient group, 57% had, in CSF, cells secreting IgG Ab against myelin basic protein (MBP) and, in another MS group, 55% had, in CSF, cells producing IgG Ab against myelin-associated glycoprotein (MAG); both MBP and MAG are possible targets for immune attack in MS. Anti-MBP and anti-MAG IgG antibody-secreting cells could occur in parallel or independently. They were rarely detected in blood, reflecting strong sequestration in CNS CSF. Their possible role in MS pathogenesis is envisaged in light of recently suggested coupling between polyclonal B-cell hyperresponsiveness and antigen-driven specific responses in autoimmune-prone individuals.

Gastrointestinal helminth fauna of Japanese moles, Mogera spp

One trematode, Echinostoma macrorchis, 2 cestodes, Hymenolepis diminuta and Choanotaenia spasskii and 5 nematodes, Parastrongyloides winchesi, Tricholinstowia talpae, Heterakis spumosa, Trichuris sp. and Capillaria soricis were obtained from 129 Mogera wogura, 233 M. kobeae and 28 M. tokudae, which were collected from almost all over Japan. All present cases were new host and locality records. The discovery of T. talpae in Japan shows the wide distribution of this species from Japan to Europe.