Ligustrazine inhibits high voltage-gated Ca~(2+) and TTX-resistant Na~+ channels of primary sensory neuron and thermal nociception in the rat:a study on peripheral mechanism

Objective Ligustrazine, also named as tetramethylpyrazine, is a compound purified from Ligusticum chuanxiong hort and has ever been testified to be a calcium antagonist. The present investigation was to determine the antinoci-ceptive effect of ligustrazine and, if any, the peripheral ionic mechanism involved. Methods Paw withdrawal Latency ( PWL) to noxious heating was measured in vivo and whole-cell patch recording was performed on small dorsal root ganglion (DRG) neurons. Results Intraplantar injection of ligustrazine (0.5 mg in 25μl) significantly prolonged the withdrawal latency of ipsilateral hindpaw to noxious heating in the rat. Ligustrazine not only reversibly inhibited high-voltage gated calcium current of dorsal root ganglion (DRG) neuron in dose-dependent manner with IC50 of 1.89 mmol/L, but also decreased tetrodotoxin (TTX) -resistant sodium current in relatively selective and dose-dependent manner with IC50 of 2.49 mmol/L. Conclusion The results suggested that ligustrazine could elevate the threshold of thermal nociception through inhibiting the high-voltage gated calcium current and TTX-resistant sodium current of DRG neuron in the rat.     

NEUROTROPIN IMMUNOSTIMULATING ACTION ON IMMUNOCOMPETENT CELLS

Neurotropin (NSP) is an extract isolated from the skin of rabbits inoculated with vaccinia virus. The present study examines the possible action of NSP on the number and function of immunocompe tent cells in mice. The experiment showed that NSP had no effect on both T and B lymphocytes of nor- malimmunized mouse spleen. The degree of plaque forming cell reaction and titre of specific antibody showed no significant differences when the NSP treated group and controls were compared. How- ever, NSP exhibited promotive effect on specific antigen binding cells in the early stage of immune responses. It was also noted that the rosette forming capacity of human T lymphocytes in vitro was restor- ed markedly by NSP. These results suggest that NSP possesses certain immunostimulating activity, particularly on the specific antigen binding cells and human T lymphocytes.     

ULTRASTRUCTURAL INVESTIGATION OF EXPERIMENTAL FRACTURE HEALING ROLE OF OSTEOGENESIS PLAYED BY FIBROBLASTS

Transmission electron microscopic investigation of standardized fractures of radii in 50 rabbits re vealed that fibroblasts took part in the formation of bony callus. The osteogenetic role played by the fibroblasts can be categorized into the following 5 aspects: a. Fibroblasts synthesize and secrete Type collagen fibrils and induce deposition of calcium salt crystals in the collagen fibrils. b. Fibroblasts produce matrix vesicles in their surroundings. These matrix vesicles become calcified and turn into floccu- lent calcospherules which coalesce and fuse into bone tissues. c. Fibroblasts harbor calcium granules in their mitochondria, thus providing calcium for calci- fication of the intercellular matrix and bone forma tion between the cells. d. Fibroblasts can transform directly into osteocytes; there is bone formation around the fibroblasts, the bone tissues surround the fibroblast in the form of bony lacuna, then the fibro- blast in the lacuna transforms into osteocyte. e. Fibroblasts can undergo degenerative changes leading to decease and replacement by bone tissues.     

EXPRESSION OF C-MYC AND N-RAS ONCOGENES IN HUMANHEPATOCELLULAR CARCINOMA AND PANCREATIC ADENOCARCINOMA A BIOCHEMICAL ANDIMMUNOCYTOCHEMICAL STUDY

WiLh RNA-DNA dot blot technique, the expression of c-myc and N-ras oncogenes in human hepato cellular carcinoma was found to be higher than in tie non-cancerous liver tissue adjacent to the carci noma (p<0.01). The expression of both oncogenes was high in the fetal liver and gradually decreased with age during development, indicating a probable co-operation of c-myc and N-ras. Immunocytochemi- cal analysis showed changes in protein products of c-myc hepatocellular carcinoma and its nan cancerous tissue were similar to those in mRNA expression. The same was true for the fetal liver during its development. A comparable study was also made on the ex pression of c-myc and N-ras oncogenes in limited samples of human pancreatic adenocarcinoma and its noncancerous tissue. The results are inconclu sive, and further studies are needed.     

THE BASIC CHARACTERISTICS OF THE NUCLEOTIDE SEQUENCE OF 5S RIBOSOMAL RNA FROM THE HUMAN WORM PARASITE FASCIOLOPSIS BUSKI

With the method of rapid gel sequencing, the complete nueleotide sequence of Fasciolopsis buski 5S rRNA has been determined: AAC GGG AUG AAG CUA GAC AUG UGG CGG CCU AGU UGG AGG UCG GAA CUC GGA AGU UAA GGA AUG UUG GGC CUG GUU AGU ACU GGU AUG GGU GAC CUU GGG AAU ACC GGG UGU UGC GUC CA_(OH) This have been compared with 553 species of other organisms 5S rRNA sequences previously published and fitted to a secondary structural model.     

Electro-oculogram of Retinal Vein Occlusion

Twenty five cases, including 26 eyes with retinal vein occlusion (RVO) were examined by means of the electro-oculogram. The results showed that 23 of the 26 eyes suffering from RVO exhibited abnormalities of the electro-oculogram (EOG). The potential difference and Arden ratio in the RVO eyes were lower than those in the normal eyes (P<0.01). The more the visual acuity of ill eyes was decreased, the higher the abnormal rate of EOG in ill eyes was. 14 eyes had the visual acuity less than 0.1, whose EOGs were abnortmal. Six eyes had the visual acuity from 0. 2 to 0. 4, in which the EOGs of 5 eyes were abnormal. Six eyes had the visual acuity more than 0. 5, a-mong which the EOGs of 4 eyes were abnormal. Based on the above observations, it may be considered that the circulatory disturbance resulting from RVO damages not only the internal layer but also the external layer of the retina. We suggest that EOG is a useful method for distingquishing lesions caused by RVO and may reflect the functional condition     

Observation on 108 Normal Ophthalmic Arteries in 80 Patients by Digital Subtraction Angiography

By digital subtraction angiography(DSA), the authors made observations on 108 normal ophthalmic arteries in 80 patients with regard to the origins, courses, branching, morphology and anastomoses of the vessels. The merits and demerits of DSA in observing the ophthalmic artery were discussed. Eye Science 1994; 10: 157- 162.     

ACTIVIT OF HUMAN PLACENTAL GAMMA GLOBULININ BLOCKING IMMUNE FUNCTIONS IN VITRO AND IN ABROGATING THE XENOGENEIC, LOCAL GRAFT-VERSUS-HOST-REEACTEON

In order to understand the mechanism of immunosuppression caused by infusion of placental gamma globulin (PGG) in patients with renal allografts, rheumatoid arthritis, and graft – versus –host disease (GCHD) following bone marrow transplantation (BMT) ,we have examined the effect of PGG in vitro and in a model of the xenogeneic , local graft –ver- sus – host reaction (LGVHR) .PGG inhibited lymphocyte proliferation in mixed lymphocyte cultures (MLC) (P<0.005) and depressed interleukin -2 (IL-2) levels in such cultures at 72 hours (P<0.01) . In contrast phytohemagglutinin (PHA) –and pokeweed mitogen (PWM) –induced T and B lymphocyte blastogenesis was not affected by such PGG treatment .PGG treatment .PGG neither decreased the [3H] TdR pulse incorporation in unstimulated lymphocytes nor affected cell viability .Cell cycle analysis by flow cytometry showed that PGG reduced the percentage of cells in S and G2, M phases during the MLC, but did not alter cell cycling during PWM-stimulated proliferation . An immunosuppressive effect of PGG on the LGCHR was tested in a model of intracutaneous transplantation of PGG –treat human lymphocytes into cyclophosphamide – immunosuppressed rats. Lymphoprep – separated human tonsillar lymphocytes were incubated with RPMI-1640 buffer containing：（1）PGG,4mg/ml,(2) human plasma albumin,4mg/ml,(3)mitomycin-C,25ug/ml, or (4) no additive. Cell of each preparation (3x107cells in 0.1ml) were injected intracutaneously into cyclophosphamide-treated male rats at separate abdominal locations. A fifth site received only the buffer solution. Five days after injection of cells ,each rat received [125 I]IUdR (10uCi) intraperitoneally and was killed after 5 hours. For each site of injection, the diameters of induration were measured and 125 I was counted . There was no difference between buffer – treated and a ibumin – treated groups either in the diameter of the area of induration (t=0.66;P>0.5)or in radioactive counts(t=0.22;P>0.05).In the PGG –treated group, the induration and radioactivity measurements were significantly less than in control groups (t=3.72 and P<0.1;t=2.62 and P<0.02,respectively ) Cytophilic antibodies in PGG were thought to inhibit an early phase of T cell activation, and not to be cytotoxicity .In the LGVHR, the immune response might be abrogated either by immuno- regulatory suppression of T cell function or by toxicity to the infused lymphoid cells. For some clinical purposes, immuno- modulating, human antibodies might be preferred to murine, monoclonal antibodies.