[Effects of exposure to noise in oil-drilling well sites on cochlea in guinea pigs]

OBJECTIVE

To prevent from hearing damage caused by noise in the sites with drilling wells.

METHODS

Intensity and spectrum of the noise produced in the sites with drilling wells were measured and analyzed. Measures, such as sound insulation, vibration damping and changing layouts of the drilling platform, were adopted, and electrocochleography (ECochG) and scanning electron microscopy were used to observe the effects of noise in the sites where drilling wells located on the hearing organs in guinea pigs after exposure.

RESULTS

There was no significant difference in APN1 latency of ECochG before and after exposure to noise. There were significant difference in hearing threshold values between the groups in a room with sound isolation, in moving status and beside the diesel engine, and no significant difference in those between the groups placed one meter horizontally and vertically away from the diesel engine on the drilling platform. Damage to hairy cell under scanning electron microscope was more severe in the guinea pigs placed beside the diesel engine and at the drilling well platform, with inclination and exfoliation of static pili of outer hairy cells, especially in the second and third lines, and part exfoliation of inner hairy cell. Hairy cells of the guinea pigs in a room with sound insulation and in moving status were basically normal. Inclination of hairy cells only could be seen in the third line.

CONCLUSION

Animal experiments indicated that the measures mentioned above are effective and should be applied widely for preventing from hearing damage.

Neurosteroids act on the GABA(A) receptor at sites on the N-terminal side of the middle of TM2

Two sets of chimeras between alphaxalone-sensitive GABA(A) receptor alpha2 or beta1 subunits and the alphaxalone-insensitive glycine receptor alpha1 subunit were constructed to determine the structural domains important for the modulatory actions of neuroactive steroids. These data suggest that the site of action for neurosteroids on GABA(A) receptors is not the same as that for volatile anesthetics and ethanol, but is on the N-terminal side of the middle of TM2.

Enhancement of glycine receptor function by ethanol is inversely correlated with molecular volume at position alpha267

Glycine and gamma-aminobutyric acid (GABA)A receptors are members of the "superfamily" of ion channels, and are sensitive to allosteric modulation by n-alcohols such as ethanol and butanol. We recently demonstrated that the mutation of Ser-267 to Ile in the alpha1 subunit abolished ethanol regulation of glycine receptors (Gly-R). In the present study, a pair of chimeric receptors was studied, in which a 45-amino acid domain comprising transmembrane domains 2 and 3 was exchanged between the Gly-Ralpha1 and gamma-aminobutyric acid rho1 subunits. Detailed pharmacologic analysis of these chimeras confirmed that this domain of the Gly-R confers enhancement of receptor function by ethanol and butanol. An extensive series of mutations at Ser-267 in the Gly-Ralpha1 subunit was also prepared, and the resulting homomeric receptors were expressed and tested for sensitivity to glycine, and allosteric modulation by alcohols. All of the mutant receptors expressed successfully in Xenopus oocytes. Mutation of Ser-267 to small amino acid residues such as Gly or Ala produced receptors in which glycine responses were potentiated by ethanol. As we have reported previously, the mutant Gly-Ralpha1 (Ser-267 --> Ile) was completely insensitive to ethanol; mutation of Ser-267 to Val had a similar effect. Mutation of Ser-267 to large residues such as His, Cys, or Tyr resulted in inhibition of Gly-R function by ethanol. These results demonstrate that the size of the amino acid residue at position alpha267 plays a crucial role in determining the functional consequences of allosteric modulation of the Gly-R by alcohols.

A subcutaneous tissue reaction in the early stage to a synthetic auditory ossicle (Bioceram) in rats

The discs of synthetic auditory ossicle (Bioceram), which are composed of aluminium oxide (Al2O3), were implanted subcutaneously in the interscapular region of 16 rats. The implanted specimens were removed at 1, 3, 7 and 14 days after implantation. The decalcified 6 microns thick sections were stained with H.E. and cell types around the implants were counted microscopically. We found that an acute inflammatory reaction occurred at one day, in which macrophages and neutrophiles predominated, and almost disappeared at about 7 days after implantation. Fibrosis began to be observed at 3 days. During this early stage, foreign body giant cells were found in only one specimen at 3 days. These findings, in comparison with those in the controls, showed that the chemical irritation of Bioceram to the subcutaneous tissue is slight, although the physical and/or chemical irritation of Bioceram lasts continuously and induces fibrosis around the bioimplant. The results so far suggest that Bioceram seems to be a satisfactorily biocompatible material, at least within the extent of 2 weeks.

The effects of steric mutations on the structure of type III antifreeze protein and its interaction with ice

The interaction of proteins with ice is poorly understood and difficult to study, partly because ice is transitory and can present many binding surfaces, and partly because structures have been determined for only two ice-binding proteins. This paper focuses on one of these, a 66-residue antifreeze protein (AFP) from eel pout. The high resolution X-ray structure of this fish AFP demonstrated that the proposed ice-binding surface is remarkably flat for such a small protein. The residues on the planar surface thought to be involved in ice binding are restrained by hydrogen bonds or by tight packing of their side-chains. To probe the requirement for a flat binding surface, a conserved alanine in the center of the AFP planar surface was substituted with larger residues. Six alanine replacement mutants (Ala16 > Cys, Thr, Met, Arg, His and Tyr), designed to disrupt the planarity of the surface and sterically block binding to ice, were characterized by X-ray crystallography and compared with the wild-type AFP. In each case, the detail provided by these crystal structures has helped explain the effects of the mutation on antifreeze activity. The substitutions, Ala16 > His and Ala16 > Tyr, were large enough to shield Gln44, one of the putative ice-binding residues, contributing to their very low thermal hysteresis activity. In addition to sterically hindering the putative ice-binding site, the bulkier residues also caused shifts in the putative ice-binding residues owing to the tight packing of side-chains on the planar surface. This unexpected consequence of the mutations helps account for the severely reduced antifreeze activity. One explanation for residual antifreeze activity in some of the mutants lies in the possibility that AFPs have a role in shaping the site on the ice to which they bind. Thus, side-chain dislocations might be partially accommodated by ice that can freeze around them. It is evident that the disruption of the planarity, by introducing larger residues at the center of the proposed ice-binding site, is not the only factor responsible for the loss of antifreeze activity. There are multiple causes including positional change and steric blockage of some putative ice-binding residues.

[Oxygenation of liver transplants as a predictor of success]

Disturbances of microcirculation followed by an impaired tissue oxygenation contribute significantly to a possible organ dysfunction after liver implantation. This study investigated the influence of the explantation technique on and the possible predictive value of the liver transplant oxygenation. Two different explantation techniques were used. The livers were either explanted as rapidly as possible followed by the careful dissection of the vessels and the bile duct ex situ-rapid perfusion or were completely prepared--in situ perfusion in both groups, the livers were preserved by arterial and porto-venous infusion of ice-cold "UW"--solution. Local partial pressure values were obtained polarographically with miniaturized needle electrodes. The liver oxygenation directly after laparotomy was comparable in both groups. We systematically investigated the potential of liver oxygenation as a predictor of transplant quality.

Expression of calmodulin and calmodulin binding proteins in rat fibroblasts stably transfected with protein kinase C and oncogenes

Molecular mechanisms leading to elevated calmodulin (CaM) expression in cancer have not yet been discovered. We have quantitated the levels of transcripts derived from all three CaM genes in a variety of the same origin rat fibroblasts transformed with oncogenes in combination with gene for protein kinase C using Northern blot analysis with three CaM gene specific cDNA probes. Five species of CaM mRNA were detected in all these cells. Surprisingly many of the investigated cell lines exhibited a decreased content of all CaM mRNAs as compared to control cells with CaMI and CaMII transcripts showing the most pronounced alterations. In contrast, CaM protein levels were increased in all these cell lines as determined by a radioimmunoassay. These results suggest that oncogenic up-regulation of CaM synthesis takes place posttranscriptionally. Several CaM binding proteins were found at different concentrations in the studied cell lines depending on the oncogenes used for transformation. However, CaM overexpression does not seem to affect the overall levels of CaM binding proteins.

[The role of urokinase-type plasminogen activator in the pathogenesis of pemphigus]

OBJECTIVE

To investigate the changes of urokinase-type plasmino-gen activator (u-PA) in the process of acantholysis in pemphigus and observe the influence of purified urokinase on the cultured skin explant.

METHODS

The expression of urokinase antigen on the pemphigus organ model was revealed by immunohistochemical method; PA activity was assayed in the acantholysis model; the influence of urokinase on the epidermis was observed by adding purified urokinase into the cultured skin explant.

RESULTS

PA activity was elevated in the acantholysis model at 24 hour and was continuing its increase at 48 and 72 hours. The expression of urokinase was high in the epidermis of pemphigus organ model; purified urokinase could induce acantholysis like changes.

CONCLUSION

Pemphigus antibody induces acantholysis through activating keratinocytes. The latter secretes an elevated u-PA, which locates on the membrane of the epidermal cells producing a limited pro-teolysis which damages the cohesion of epidermal cells.

Sites of alcohol and volatile anaesthetic action on GABA(A) and glycine receptors

Volatile anaesthetics have historically been considered to act in a nonspecific manner on the central nervous system. More recent studies, however, have revealed that the receptors for inhibitory neurotransmitters such as gamma-aminobutyric acid (GABA) and glycine are sensitive to clinically relevant concentrations of inhaled anaesthetics. The function of GABA(A) and glycine receptors is enhanced by a number of anaesthetics and alcohols, whereas activity of the related GABA rho1 receptor is reduced. We have used this difference in pharmacology to investigate the molecular basis for modulation of these receptors by anaesthetics and alcohols. By using chimaeric receptor constructs, we have identified a region of 45 amino-acid residues that is both necessary and sufficient for the enhancement of receptor function. Within this region, two specific amino-acid residues in transmembrane domains 2 and 3 are critical for allosteric modulation of both GABA(A) and glycine receptors by alcohols and two volatile anaesthetics. These observations support the idea that anaesthetics exert a specific effect on these ion-channel proteins, and allow for the future testing of specific hypotheses of the action of anaesthetics.

[The use of "self-locking" artificial vertebral prosthesis in surgical treatment for spinal tumor]

OBJECTIVE

To evaluate the use of "self-locking" artificial vertebral prosthesis in surgical treatment for spinal tumor.

METHODS

From 1992 to 1996, 14 cases with spinal tumor and paraplegia were treated with "self locking" artificial vertebral prosthesis designed by one of the authors (Ye Qibin) in our department. There were malignant giant cell tumor 2 cases; myeloma 4 cases; metastatic tumor 4 cases and one each with chondrosarcoma, malignant fibrous histocytoma, fibrosarcoma, hemangioma. After radical resection of the tumor and thorough decompression, the vertebral prosthesis was applied to reconstruct the spinal stability. Adjunctive chemotherapy or/and radiotherapy was given postoperatively.

RESULTS

At the average follow-up period of 20.6 months 10 cases are still alive, 5 of them had survived for more than 2 years. 4 cases died with the average survival period of 19.8 months after operation. Almost all the patients obtained the improvement of the quality of the life with relative pain-free and intact neurologic function after operation.

CONCLUSION

With "self-locking" artificial vertebral prosthesis after thorough anterior resection of spinal tumor, it is possible to provide solid internal fixation to reconstruct the spinal stability.

Long-term observation of subcutaneous tissue reaction to synthetic auditory ossicle (Apaceram) in rats

The present study evaluates histological characteristics of the soft tissue response to long-term implantation of Apaceram discs composed of dense hydroxyapatite in rats. Discs were implanted into the subcutaneous tissue of 76 rats for six to 20 months. Decalcified histological sections stained with haematoxylin and eosin (H & E) and Mallory's azan were examined. Different cell types surrounding implants were counted. The greatest proportion of macrophages was found at six months (13.5 per cent). This proportion gradually decreased to four per cent at 20 months. Small numbers of lymphocytes and foreign body giant cells were observed in every group, but neither neutrophils nor osteogenesis were observed in any specimens. Results of the present study and previous related studies indicate that despite reappearance of a small number of macrophages six months after implantation, Apaceram is useful for reconstructive surgery.

Formation of DNA adducts and oxidative base damage by copper mediated oxidation of dopamine and 6-hydroxydopamine

We have investigated the formation of DNA adducts and oxidative base damage produced by copper sulfate activation of dopamine and 6-hydroxydopamine. In the presence of 10 microM copper sulfate both 100 microM dopamine and 100 microM 6-hydroxydopamine formed three similar DNA adducts with relative adduct levels of 8.36 +/- 2.23 x 10(-8) and 7.98 +/- 2.53 x 10(-8), respectively. The levels of 8-hydroxy-2'-deoxyguanosine produced by these incubations were 5.2 +/- 0.03, 32.6 +/- 2.4, and 0.01 pmol/microg DNA for dopamine, 6-hydroxydopamine, and control incubations, respectively, representing a 520- to 3260-fold increase in the level of this base oxidation product. The use of specific chelators and catalase demonstrated that the reduction of Cu2+ to Cu1+ and the formation of a peroxide plays an important role in the activation of dopamine and 6-hydroxydopamine to form adducts and oxidative base damage. Our results suggest that the oxidation of dopamine by transition metals present in the brain may lead to the formation of both DNA adducts and oxidative base damage in dopaminergic cells. We propose that these processes may contribute to the observed loss of dopaminergic neurons in patients with Parkinson's disease.

Structure and expression of the chicken calmodulin I gene

The chicken calmodulin I (CaMI) gene has been isolated and characterized on the level of cDNA and genomic DNA. The deduced amino acid (aa) sequence is identical to the one of chicken CaMII which consists of 148 aa. The CaMI gene contains six exons. Its intron/exon organization is identical to that of the chicken CaMII and the CaMI and CaMIII genes of rat and human. Expression of the CaMI gene was detected in all chicken tissues examined, although at varying levels. The gene is transcribed into four mRNAs of 0.8, 1.4, 1.7 and 4.4 kb as determined by Northern blot analysis. Our results demonstrate that the "multigene-one-protein" principle of CaM synthesis is not only applicable to mammals whose CaM is encoded by three different genes, but also to chickens.

Effect in supralethally irradiated rats of granulocyte colony-stimulating factor and lisofylline on hematopoietic reconstitution by syngeneic bone marrow or whole organ passenger leukocytes

We have previously shown the existence of migratory hematopoietic stem cells in adult solid organs. This study demonstrates that granulocyte colony-stimulating factor (G-CSF) and lisofylline, a phosphatidic acid inhibitor that suppresses hematopoiesis-inhibiting cytokines, can enhance the engraftment of organ-based hematopoietic stem cells. When syngeneic heart grafts or liver nonparenchymal cells were transplanted into lethally irradiated (9.5 Gy) Lewis rats, complete hematopoietic reconstitution and animal survival were significantly improved by treating the recipient with G-CSF or, to a lesser extent, with lisofylline. Pretreatment of hepatic nonparenchymal cell donors with G-CSF, but not lisofylline, also resulted in striking improvement of recipient survival which was associated with an augmented subpopulation of donor stem cells. The results suggest that these drugs can be used to enhance the chimerism that we postulate to be the basis of organ allograft acceptance.

Detection of N7-(2-hydroxyethyl)guanine adducts in DNA and 9L cells treated with 1-(2-chloroethyl)-1-nitrosourea

A sensitive analytical method, HPLC-ED, was developed for the measurement of N7-(2-hydroxyethyl)guanine (N7-HOEtG). A detection limit of 3.2 N7-HOEtG/10(8) nucleotides was obtained with this method. Linear dose response curves for the formation of N7-HOEtG were obtained following treatment of either calf thymus DNA or 9L cells with 1-(2-chloroethyl)-1-nitrosourea (CNU). Using HPLC-ED a significant increase in the level of N7-HOEtG could be detected in 9L cells following treatment with 5 microM CNU. Our study suggests that with this analytical method the formation of N7-HOEtG in the white blood cells of patients treated with chloroethylnitrosoureas may be determined.

Domain-specific interactions of human HP1-type chromodomain proteins and inner nuclear membrane protein LBR

HP1-type chromodomain proteins self-associate as well as interact with the inner nuclear membrane protein LBR (lamin B receptor) and transcriptional coactivators TIF1alpha and TIF1beta. The domains of these proteins that mediate their various interactions have not been entirely defined. HP1-type proteins are predicted by hydrophobic cluster analysis to consist of two homologous but distinct globular domains, corresponding to the chromodomain and chromo shadow domain, separated by a hinge region. We show here that the chromo shadow domain mediates the self-associations of HP1-type proteins and is also necessary for binding to LBR both in vitro and in the yeast two-hybrid assay. Hydrophobic cluster analysis also predicts that the nucleoplasmic amino-terminal portion of LBR contains two globular domains separated by a hinge region. The interactions of the LBR domains with an HP1-type protein were also analyzed by the yeast two-hybrid and in vitro binding assays, which showed that a portion of the second globular domain is necessary for binding. The modular domain organization of HP1-type proteins and LBR can explain some of the diverse protein-protein interactions at the chromatin-lamina-membrane interface of the nuclear envelope.

Bripiodionen, a new inhibitor of human cytomegalovirus protease from Streptomyces sp. WC76599

Bripiodionen (1), a new natural product, was isolated from Streptomyces sp. WC76599 during the screening of microbial fermentation extracts for their ability to inhibit human cytomegalovirus protease. The structure of 1 was elucidated by spectroscopic methods. Compound 1 displayed inhibitory activity against human cytomegalovirus protease with an IC50 value of 30 microM.

Konishiol, a new sesquiterpene, and bioactive components from Cunninghamia konishii

Three sesquiterpenes, konishiol (1), cadalenol (2), 3-cedranol (3), one diterpene, manool (4), and one lignan, (+)-tsugacetal (5), have been isolated, for the first time, from the whole plant of Cunninghamia konishii by using bioactivity-directed fractionation. Compound 1 is new to the literature, and its chemical structure was determined by various spectroscopic analyses including EIMS, HREIMS, NOE, NOESY, and by preparing its di-acetyl derivative (1a). Compounds 2-5 showed moderate to weak bioactivities in brine shrimp (BST) and mosquito larvae (YFM) bioassays as well as cytotoxicities against three human solid tumor cell lines.

[A seroepidemiological study of hepatitis viruses among the patients with different types of liver disease in Qinhuangdao]

This article described a seroepidemiological surveillance in 326 patients with different clinical types of liver disease (acute hepatitis, AH; chronic hepatitis, CH; liver cirrhosis, LC; hepatocellular carcinoma, HCC) from hospitals in Qinhuangdao city during 1992-1995. The results showed that HAV infection could not develop chronic hepatitis. Among 238 patients of CH, LC, and HCC, anti-HAV IgM was not detected. HBV infection was the main pathogenic factor of CH, LC, and HCC with an infection rates of 77.78%, 84.21%, and 94.29%, respectively, the average rate of infection was 3.8 times higher than that in AH. HCV infection rate was increased gradually with development of chronic liver syndrome. Anti-HCV positive rate was 5.56% in CH, but 14.74% and 20.00% in LC and HCC respectively. HEV infection was found in patients with all types of liver disease with an average positive rate of 13.19%. It was not found that single HEV infection developed in CH, LC, and HCC. The average rate of super infection was 17.18% among all the patients, but the super infection rate in LC and HCC was 1.93 times higher than that in AH and CH. It seems that the super infection of HBV and HCV was the main factor for worsened liver symptoms and for developing LC and HCC.

4-deoxyannomontacin and (2,4-cis and trans)-annomontacinone, new bioactive mono-tetrahydrofuran annonaceous acetogenins from Goniothalamus giganteus

4-Deoxyannomontacin (1) and a mixture of (2,4-cis and trans)-annomontacinone (2), new bioactive mono-tetrahydrofuran (THF) gamma-lactone and keto-lactone acetogenins, respectively, as well as five known mono-THF acetogenins [xylomaticin, longifolicin, longicoricin, (2,4-cis and trans)-gigantetrocinone, and (2,4-cis and trans)-gigantetroneninone], were isolated from the bark of Goniothalamus giganteus (Annonaceae) by activity-directed fractionation using the brine shrimp lethality test (BST). The structures were elucidated based on spectroscopic and chemical methods. The absolute stereochemistries of 1 and 2 were determined by the advanced Mosher ester method and by circular dichroism (CD). Determination of the absolute stereochemistry at C-10 as R for 1 is the first example of the direct determination of the absolute stereochemistry of a carbinol position isolated from other functional groups in the annonaceous acetogenins. 1 and 2 showed selective and potent cytotoxicities to certain human tumor cell lines and were comparable to the activity of rotenone against yellow fever mosquito larvae.

Construction of a recombinant human GM-CSF/MCAF fusion protein and study on itsin vitro andin vivo antitumor effects

A novel cytokine fusion protein was constructed by fusing granulocyte macrophage colony stimulating factor (GM-CSF) with monocyte chemotactic activating factor (MCAF), which acts as a factor directing effector cells (monocytes) to a target site. The recombinant human GM-CSF/MCAF fusion protein could sustain the growth of GMCSF-dependent cell line TF1 and was chemotactic for monocytes. Thein vitro antitumor effect showed that rhGM-CSF/MCAF could activate monocytes to inhibit the growth of several human tumor cell lines, including a promyelocyte leukemia cell line HL-60, a lung adenocarcinoma cell line A549, a hepatoma cell line SMMC-7721 and a melanoma cell line Bowes. Furthermore, the cytotoxicity of monocytes activated by rhGM-CSF/MCAF against HL-60 and A549 was greater than that activated by GM-CSF or MCAF alone, even greater than that activated by a combination of GM-CSF and MCAF, suggesting that the fusion protein has synergistic or enhanced effects. Thein vivo antitumor effect indicated that rhGM-CSF/MCAF had marked antitumor effect against A549 tumor in nude mice and even completely suppressed tumor formation. rhGM-CSF/MCAF was significantly more effective in inhibiting tumor growth than rhGM-CSF. Histological analysis showed that tumor site injected with rhGM-CSF/MCAF was infiltrated by a large number of monocytes while a sparse infiltration of monocytes was observed at the tumor site injected with rhGM-CSF or normal saline, suggesting that the antitumor effect of rhGM-CSF/MCAF was mediated by the recruitment of a large number of monocytes to the tumor site.

Analysis of chronic rejection and obliterative arteriopathy. Possible contributions of donor antigen-presenting cells and lymphatic disruption

Sequential analysis of changes that lead to chronic rejection was undertaken in an animal model of chronic rejection and obliterative arteriopathy. Brown Norway rats are pretreated with a Lewis bone marrow infusion or a Lewis orthotopic liver allograft and a short course of immunosuppression. They are challenged 100 days later with a Lewis heterotopic heart graft without immunosuppression. The heart grafts in both groups undergo a transient acute rejection, but all rats are operationally tolerant; the heart grafts are accepted and remain beating for more than 100 days. Early arterial remodeling, marked by arterial bromodeoxyuridine incorporation, occurred in both groups between 5 and 30 days during the transient acute rejection. It coincided with the presence of interstitial (but not arterial intimal) inflammation and lymphatic disruption and resulted in mild intimal thickening. Significant arterial narrowing occurred only in the bone-marrow-pretreated rats between 60 and 100 days. It was associated with T lymphocyte and macrophage inflammation of the heart graft that accumulated in the endocardium and arterial intima and adventitia near draining lymphatics. There also was loss of passenger leukocytes from the heart graft, up-regulation of cytokine mRNA and major histocompatibility class II on the endothelium, and focal disruption of lymphatics. In contrast, long-surviving heart grafts from the Lewis orthotopic liver allograft pretreated group are near normal and freedom from chronic rejection in this group was associated with persistence of donor major histocompatibility class-II-positive hematolymphoid cells, including OX62+ donor dendritic cells. This study offers insights into two different aspects of chronic rejection: 1) possible mechanisms underlying the persistent immunological injury and 2) the association between immunological injury and the development of obliterative arteriopathy. Based on the findings, it is not unreasonable to raise the testable hypothesis that direct presentation of alloantigen by donor antigen-presenting cells is required for long-term, chronic-rejection-free allograft acceptance. In addition, chronic intermittent lymphatic disruption is implicated as a possible mechanism for the association between chronic interstitial allograft inflammation and the development of obliterative arteriopathy.

[Ultramicrostructural changes of articular cartilage, subchondral bone and synovium in human osteoarthritis of patellofemoral joint]

Ten patients with patellofemoral joint osteoarthritis (OA) were studied by electron microscope (SEM&TEM) to identify ultramicrostructural changes in the destroyed articular cartilage, subchondral bone and synovium. According to the results obtained, the author suggested that (1) Articular cartilage, subchondral bone and synovium in patellofemoral joint OA were noted to be in various degree of ultramicrostructural changes; (2) The cartilage degeneration in lateral compartment of patellofemoral joint were much more severe than that in medial compartment; (3) The subchondral bone had a strong tendency to undergo selerosis in the form of thicking and confluence of the trabeculae to form massive block of bone, which were not parallel to alteration of cartilage, and the rules of alteration were related to the character of loading; (4) The repair tissues of I-II grade degenerative cartilage were similar to normal cartilage, but those of III-IV grade degenerative cartilage were similar to fibrocartilage in many ways, because the source of repair tissues were different between them; (5) Alteration of synovium revealed only mild non-specific inflammatory changes following the changes of articular cartilage; (6) I-II grade patellofemoral joint OA was treated by conservative methods and III-IV grade OA should be treated by patellofemoral joint resurfacing.

Investigation of the DNA adducts formed in B6C3F1 mice treated with benzene: implications for molecular dosimetry

We have investigated the formation of DNA adducts in the bone marrow and white blood cells of male B6C3F1 mice treated with benzene using P1-enhanced 32P-postlabeling. No adducts were detected in the bone marrow of controls or mice treated with various doses of benzene once a day. After twice-daily treatment for 1 to 7 days with benzene, 440 mg/kg, one major (no. 1) and up to two minor DNA adducts were detected in both the bone marrow and white blood cells. The relative adduct levels in these cells ranged from 0.06 to 1.46 x 10(-7). a significant correlation (r2 = 0.95) between levels of adducts in bone marrow and white blood cells was observed. After a 7-day treatment with benzene, 440 mg/kg twice a day, the number of cells per femur decreased from 1.6 x 10(7) to 0.85 x 10(7), indicating myelotoxicity. In contrast, administration of benzene once a day produced only a small decrease in bone marrow cellularity. The observed induction of toxicity in bone marrow was paralleled by formation of DNA adducts. In vitro treatment of bone marrow with hydroquinone (HQ) for 24 hr produced the same DNA adducts as found after treatment of mice with benzene, suggesting that HQ is the principal metabolite of benzene leading to DNA adduct formation in vivo. Using P-postlabeling the principal DNA adduct formed in vivo was compared with N2-(4-hydroxyphenyl)-2'-deoxyguanosine-3'-phosphate. The results of this comparison demonstrated that the DNA adduct formed in vivo co-chromatographs with N2-(4-hydroxyphenyl)-2'-deoxyguanosine-3'-phosphate. These studies indicate that metabolic activation of benzene leads to the formation of DNA adducts in bone marrow and white blood cells and suggest that measurement of DNA adducts in white blood cells may be an indicator of biological effect following benzene exposure.

Three new adjacent bis-tetrahydrofuran acetogenins with four hydroxyl groups from Asimina triloba

Three new adjacent bis-tetrahydrofuran ring Annonaceous acetogenins with four hydroxy groups, bullatetrocin (1), 10-hydroxyasimicin (2), and 10-hydroxytrilobacin (3), were isolated by activity-directed fractionation from the stem bark of Asimina triloba. Their structures were established on the basis of chemical and spectral evidence. The absolute stereochemistry at the C-10 hydroxy position was determined by converting 2 and 3 to their ketolactone isomers, 2,4-cis/trans 10-hydroxyasimicinones and 2,4-cis/trans 10-hydroxytrilobacinones, respectively. The bioactivities of the new compounds against brine shrimp larvae and six human solid-tumor cell lines are reported, and structure-activity relationships between trihydroxylated and tetrahydroxylated acetogenins are discussed. In addition to 1-3, gigantetrocin A, 2,4-cis/trans-gigantetrocin A-ones, annonacin, and annonacin A were also isolated for the first time from this species.

Chlorinated annonaceous acetogenins and their bioactivities

4(S)-Chloro-4-deoxygigantetrocin A and 4(S), 18-dichloro-4,18-dideoxyasimilobin were obtained by treating gigantetrocin A with triphenylphosphine and CCl4. The structures were determined by spectroscopic methods. The chlorinated compounds show decreased bioactivities in the brine shrimp lethality test and against human tumor cell lines.

Effect of anticomplement agent K76 COOH on hamster-to-rat and guinea pig-to-rat heart xenotransplantation

In normal rats, the xenobiotic K76 inhibited the C5 and probably the C2 and C3 steps of complement and effectively depressed classical complement pathway activity, alternative complement pathway activity, and the C3 complement component during and well beyond the drug's 3-hr half-life. It was tested alone and with intramuscular tacrolimus (TAC) and/or intragastric cyclophosphamide (CP) in rat recipients of heterotopic hearts from guinea pig (discordant) and hamster (concordant) donors. Single prevascularization doses of 100 and 200 mg/kg increased the median survival time of guinea pig hearts from 0.17 hr in untreated controls to 1.7 hr and 10.2 hr, respectively; with repeated injections of the 200-mg dose every 9-12 hr, graft survival time was increased to 18.1 hr. Pretreatment of guinea pig heart recipients for 10 days with TAC and CP, with or without perioperative splenectomy or infusion of donor bone marrow, further increased median graft survival time to 24 hr. Among the guinea pig recipients, the majority of treated animals died with a beating heart from respiratory failure that was ascribed to anaphylatoxins. Hamster heart survival also was increased with monotherapy using 200 mg/kg b.i.d. i.v. K76 (limited by protocol to 6 days), but only from 3 to 4 days. Survival was prolonged to 7 days with the addition of K76 of intragastric CP at 5 mg/kg per day begun 1 day before operation (to a limit of 9 days); it was prolonged to 4.5 days with the addition of intramuscular TAC at 2 mg/kg per day beginning on the day of transplantation and continued indefinitely. In contrast to the limited efficacy of the single drugs, or any two drugs in combination, the three drugs together (K76, CP, and TAC) in the same dose schedules increased median graft survival time to 61 days. Antihamster antibodies rapidly increased during the first 5 days after transplantation, and plateaued at an abnormal level in animals with long graft survival times without immediate humoral rejection. However, rejection could not be reliably prevented, and was present even in most of the xenografts recovered from most of the animals dying (usually from infection) with a beating heart. Thus, although effective complement inhibition with K76 was achieved in both guinea pig- and hamster-to-rat heart transplant models, the results suggest that effective interruption of the complement cascade will have a limited role, if any, in the induction of xenograft acceptance.

Surgical treatment of spinal tumor (analysis of 32 cases)

With the advance of spinal surgery in the last decade, surgical treatment of spinal tumors has been no longer limited to simple laminectomy. The principles of surgical treatment of spinal tumors include: (1) anterior approach for the anterior lesion and posterior approach for the posterior lesion; (2) combined anterior and posterior approach for extensive lesions and (3) internal fixation for spinal stability. 32 cases of spinal tumors were treated on the basis of the above guiding principles and 84% (27/32) showed excellent or good results.

Production of 8-hydroxy-2'-deoxguanosine in DNA by microsomal activation of tamoxifen and 4-hydroxytamoxifen

Using rat liver microsomal preparations, we have investigated the activation of the anti-estrogen compound tamoxifen (TAM) and its metabolite 4-hydroxytamoxifen (4-OH-TAM) to form 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in DNA. When reduced nicotinamide adenine dinucleotide phosphate (NADPH) was used as a cofactor in microsomal activation of either TAM or 4-OH-TAM, the levels of 8-OH-dG were 3-fold higher than in microsomes plus cofactor only. In contrast, no significant increase in the level of 8-OH-dG was detected in DNA samples from microsomal activation of either TAM or 4-OH-TAM with cumene hydroperoxide as the cofactor. These results demonstrate that the microsomal activation of TAM and 4-OH-TAM to form 8-OH-dG is dependent upon the cofactor used. The addition of either EDTA or catalase to the activation system significantly decreased the formation of 8-OH-dG by TAM, but not by 4-OH-TAM. The presence of either sodium azide, superoxide dismutase or mannitol inhibited the formation of 8-OH-dG by both TAM and 4-OH-TAM. Taken together these findings indicate that microsomal activation of TAM and 4-OH-TAM with NADPH generates reactive oxygen species which result in the formation of 8-OH-dG. We propose that the formation of 8-OH-dG by TAM and its metabolites may contribute to the observed carcinogenic effects of TAM.

cis-gigantrionenin and 4-acetyl gigantetrocin A, two new bioactive annonaceous acetogenins from Goniothalamus giganteus, and the stereochemistries of acetogenin 1,2,5-triols

Using activity-directed fractionation, two new bioactive acetogenins, cis-gigantrionenin (1) and 4-acetyl gigantetrocin A (2), have been isolated from the bark of Goniothalamus giganteus (Annonaceae). Compound 1 has a cis-mono-THF ring with one flanking hydroxyl and possesses a cis-double bond at C-21/22 of the aliphatic chain; it represents only the second example of the cis-mono-THF ring annonaceous acetogenins having one flanking hydroxyl. Compound 2 has a trans-mono-THF ring with one flanking hydroxyl, but it possesses a mono-acetyl group at the 4-OH position; it represents only the second natural example of the acetylated annonaceous acetogenins; the first acetogenin reported, uvaricin, was mono-acetylated at the 24-OH. The stereochemistries of 1 and 2 were determined by the advanced Mosher ester method. In addition, the absolute stereochemistries of gigantriocin (3), gigantrionenin (4), and giganenin (5) were determined by the advanced Mosher ester method and by circular dichroism (CD). The stereochemistries of the 7,8-diols in murihexocins A (6) and B (7) were determined to have the S,S-configurations, respectively.

[Different techniques of internal fixation applied in lumbosacral fusion: 83 cases analysis]

Posterior lumbosacral fusion using bone graft without internal fixation requires long immobilization and has high rate of pseudoarthrosis. To overcome such limitation technique of spinal internal fixation has been developed and applied in past twenty years. Since 1982, the authors have done lumbosacral fusion with internal fixation and bone graft by using Harrington alar hook (32 cases), luque ring (26 cases), Galveston technique (7 cases), Steffee plate (10 cases), Dick pedicle screw (1 cases), RF instrumentation (3 cases) and CD technique (4 cases). Totally 83 cases have been treated, which include paralytic pelvic tilt (9 cases), spinal fracture (4 cases), lumbosacral tuberculosis (5 cases), degenerative stenosis (21 cases); L5-S1 spondylolisthesis (38 cases), L5-S1 disc protrusion (4 cases); L5 semivertebra (1 cases) and neurofibromatosis (1 cases). Patients have been follow-up for 63.7 months on average. Good fusion has been seen in 82 cases (98.8%). The procedure does not need long immobilization and has less complication.

Applying Mosher's method to acetogenins bearing vicinal diols. The absolute configurations of muricatetrocin C and rollidecins A and B, new bioactive acetogenins from Rollinia mucosa

Muricatetrocin C (1), rollidecin A (2), and rollidecin B (3), three new bioactive annonaceous acetogenins bearing vicinal diols, were isolated from the leaves of Rollinia mucosa (Annonaceae) using activity-directed fractionation. The total structural elucidations of 1-3, including the absolute stereochemistries of the vicinal diols, were achieved by analyzing their per-Mosher ester derivatives. All three compounds showed potent and selective inhibitory effects against several human cancer cell lines.

An alpha-mercaptoacrylic acid derivative is a selective nonpeptide cell-permeable calpain inhibitor and is neuroprotective

Overactivation of calcium-activated neutral protease (calpain) has been implicated in the pathophysiology of several degenerative conditions, including stroke, myocardial ischemia, neuromuscular degeneration, and cataract formation. Alpha-mercaptoacrylate derivatives (exemplified by PD150606), with potent and selective inhibitory actions against calpain, have been identified. PD150606 exhibits the following characteristics: (i) Ki values for mu- and m-calpains of 0.21 microM and 0.37 microM, respectively, (ii) high specificity for calpains relative to other proteases, (iii) uncompetitive inhibition with respect to substrate, and (iv) it does not shield calpain against inactivation by the active-site inhibitor trans-(epoxysuccinyl)-L-leucyl-amido-3-methylbutane, suggesting a nonactive site action for PD150606. The recombinant calcium-binding domain from each of the large or small subunits of mu-calpain was found to interact with PD150606. In low micromolar range, PD15O6O6 inhibited calpain activity in two intact cell systems. The neuroprotective effects of this class of compound were also demonstrated by the ability of PD150606 to attenuate hypoxic/hypoglycemic injury to cerebrocortical neurons in culture and excitotoxic injury to Purkinje cells in cerebellar slices.

Interaction between an integral protein of the nuclear envelope inner membrane and human chromodomain proteins homologous to Drosophila HP1

At the nuclear envelope in higher eukaryotic cells, the nuclear lamina and the heterochromatin are adjacent to the inner nuclear membrane, and their attachment is presumably mediated by integral membrane proteins. In a yeast two-hybrid screen, the nucleoplasmic domain of lamin B receptor (LBR), an integral protein of the inner nuclear membrane, associated with two human polypeptides homologous to Drosophila HP1, a heterochromatin protein involved in position-effect variegation. LBR fusion proteins bound to HP1 proteins synthesized by in vitro translation and present in cell lysates. Antibodies against LBR also co-immunoprecipitated HP1 proteins from cell extracts. LBR can interact with chromodomain proteins that are highly conserved in eukaryotic species and may function in the attachment of heterochromatin to the inner nuclear membrane in cells.

[Failure and complication following surgical treatment of scoliosis: analysis of 101 cases]

Complications occur frequently after surgical treatment of scoliosis. In order to prevent from them effectively, 101 cases with failure and postoperative complications were analysed. They included rod fracture in 22 cases (15 Harrington rods, 4 Zielke rods, and 3 Luque rods); recurrence of curve severity in 12 cases; broken or loossened luque wires in 15 cases; loss of thoracic kyphosis (flat back) in 6 cases; progressive kyphosis with or without paraplegia following incorrect posterior decompression in 5 cases; and increased unbalance of shoulders after instrumentation in 2 cases due to neglect of the tilting of the first thoracic vertebra. Infection occurred in 8 cases (incision infection 7 cases; deep wound infection in 1 case); and pneumothorax in 1 cases. They were induced by biomechanical factors in 23 cases (22.77%), incorrect selections of indications in 29 cases (28.71%), oprational mistakes in 37 cases (36.63%), internal fixation factors in 15 cases (14.85%). The authors hold that there are quite a lot of factors leading to occurrence of complications and the effective way for prevention from them is to understand the factors and main technical points related to internal fixation.

Rollinecins A and B: two new bioactive annonaceous acetogenins from Rollinia mucosa

Two new mono-THF ring acetogenins, rollinecins A (1) and B (2), were isolated from the partitioned ethanolic extracts of the leaves of Rollinia mucosa (Annonaceae) by activity-directed fractionation. 1 and 2 are epimeric at the C-14 carbinol stereocenter. Their absolute stereochemical structures were solved by preparing their respective per-Mosher ester derivatives. 1 and 2 showed equivalent and selective in vitro activities against several human solid tumor cell lines.

Longimicins A-D: novel bioactive acetogenins from Asimina longifolia (annonaceae) and structure-activity relationships of asimicin type of annonaceous acetogenins

Bioactivity-directed fractionation of the ethanol extract of Asimina longifolia led to the isolation of four novel bioactive annonaceous acetogenins: longimicins A-D (1-4). Compounds 1-4 represent the asimicin type of acetogenins; however, the locations of the adjacent bis-tetrahydrofuran (THF) ring moieties are shifted along the aliphatic chains compared to the known compounds of this type. They are the first examples among this type of acetogenins with the placements of the ring systems altered. Compounds 1-4 showed bioactivities in several bioassays, but they are less active than their structural isomers. Study of their structure-activity relationships (SAR) reveals that the position of the adjacent bis-THF ring moiety is essential for maximization of the bioactivities among these asimicin type annonaceous acetogenins.

[Selective training of the vastus medialis muscle using electrical stimulator for chondromalacia patella]

Chondromalacia patella is closely related with subluxation and tilt of patella, as well as with muscular atrophy of quadriceps, especially in vastus medialis muscle. 364 cases of chondromalacia patella were treated with selective training of the vastus medialis muscle using electrical stimulator in our hospital. 211 cases were followed up after treatment from 6 months to 3 years. Among them excellent and good results were seen in 130 cases (62%), fair results were seen in 69 cases (33%) and no change was seen in 12 cases (5%). Significant reduction of CA (P < 0.01) and LPA (P < 0.001) were observed in all these patients in comparison with their primary angle. We believe that the selective training of the vastus medialis muscle using electrical stimulator is one of the effective methods for the treatment of chondromalacia patella.

Longifolicin, longicoricin, and gigantetroneninone, three novel bioactive mono-tetrahydrofuran annonaceous acetogenins from Asimina longifolia (Annonaceae)

Longifolicin (1), longicoricin (2) and (2,4-cis and trans)-gigantetroneninone (3), three novel bioactive mono-tetra-hydrofuran (THF) gamma-lactone acetogenins, were isolated from the leaves and twigs of Asimina longifolia (Annonaceae) by directing the fractionation with the brine shrimp lethality test (BST). The structures were elucidated based on spectroscopic and chemical methods. Compounds 1-3 showed selective and potent cytotoxicities to certain human tumor cell lines.