In vivo investigation of ceftiofur-loaded gelatin and PLGA microspheres in beagle dogs

Drug delivery systems based on polymer microspheres have received considerable attention. Ceftiofur sodium and ceftiofur hydrochloride is widely used for the treatment of bacterial diseases in animals but the delivery in vivo has not been reported. In this paper, we report the synthesis of microspheres from gelatin and PLGA, two kinds of typical natural and artificial materials, for loading ceftiofur and the in vivo investigation of the pharmacokinetics in beagle dogs. By controlling the synthesis parameters, gelatin and PLGA microspheres with diameter between 5 and 35 microns were obtained. Assay procedures based on high performance liquid chromatography were evaluated and confirmed. The dogs were randomly divided into three groups, i.e., control group, gelatin group, and PLGA group and administrated via intravenous injection. Plasma concentrations of ceftiofur over time were measured and analyzed. Results indicate that the main kinetic parameters do not show significant difference for the gelatin group and control group, but the area under the curve, plasma half-life, apparent volume of distribution, and clearance ratio of PLGA group show significant difference from the gelatin group and the control group. The PLGA microspheres show a low area under the curve but long time release.

Profilin 1 potentiates apoptosis induced by staurosporine in cancer cells

The correlation between the loss of Profilin 1 (Pfn1) with tumor progression indicated that Pfn1 is a tumor suppressor in human carcinoma. The molecular mechanisms underlying Pfn1 tumor suppression has yet to be elucidated. In this study, we showed that Pfn1 overexpression sensitizes cancer cells to apoptosis through the typical intrinsic apoptotic pathway. Mechanistically, the increased Pfn1 expression mediated the upregulation of p53R273H, one of the most common tumor-associated hotspot mutations of p53, with transactivation deletion in tumorigenesis and increased localization of p53R273H in cytoplasm. Further studies showed that mutant p53R273H was involved in apoptosis induced by Staurosporine (STS) via transcription-independent mitochondrial functions. We observed (i) the increased cytosolic localization of p53R273H, (ii) the activation of phosphorylation at Ser15, (iii) its mitochondrial localization; Pfn1 acted as a positive regulator of these processes. We also found that Pfn1 interacted with p53R273H and thus facilitated its exertion over the transcription-independent activity in the cytoplasm during drug action. Our results define a new function and mechanism of Pfn1 demonstrating that the combined effect with apoptotic agents led to a synergistic increase in apoptosis. In addition, p53R273H abrogating DNA binding was found to play a major role in the Pfn1- sensitized apoptosis through a transactivation-independent and cytosolic activity.

Silencing STAT3 may inhibit cell growth through regulating signaling pathway, telomerase, cell cycle, apoptosis and angiogenesis in hepatocellular carcinoma: potential uses for gene therapy

The genesis and development of hepatocellular carcinoma (HCC) is related to the abnormity of signaling pathway, telomerase, cell cycle, apoptosis, angiogenesis, and others, in which STAT3 signaling pathway plays a key role. The HCC cell line HepG2 was transfected with small interfering RNA (siRNA) directed against STAT3. After 72 h, cell growth and cycle were analysed by MTT and Flow cytometry. Then, the protein was extracted and the protein expression of STAT3, Smad3, p44/42, TERT, caspase-3, XIAP, Grp-78, HSP-27, MMP-2, MMP-9, VEGF-A, cyclin A, and cyclin E was detected by Western blot. After the transfection, HCC cell growth was inhibited during the 24-72 h time period and the cell cycle was arrested in G0/G1. STAT3 protein expression was inhibited at 72 h after the transfection. Interestingly, Smad3, p-caspase-3, p-p44/42, Grp78, cyclin A, and cyclin E protein expression was increased at 72 h, while TERT, caspase-3, XIAP, MMP-2, MMP-9, and VEGF-A protein expression decreased at 72 h. However, P44/42, and HSP27 protein expression showed no change following transfection. The results demonstrated that STAT3 signaling pathway may participate in HCC genesis and development through regulating the protein expression of other signaling pathway, telomerase, apoptosis, cell cycle and angiogenesis; thereby, blockade of the Stat3 pathway represents a potential strategy for future treatment.

KEYWORDS

STAT3, signaling pathway, telomerase, cell cycle, apoptosis, angiogenesis.

Resistance to Fusarium head blight and seedling blight in wheat is associated with activation of a cytochrome p450 gene

ABSTRACT One plant genotype displays a resistance phenotype at one development stage but a susceptible reaction to the same pathogen at another stage, which is referred to here as resistance inversion. In wheat, Fusarium head blight (FHB)-resistant cv. Sumai3 showed a Fusarium seedling blight (FSB)-susceptible reaction whereas FHB-susceptible cv. Annong8455 exhibited FSB resistance when challenged with a Fusarium asiaticum strain that produces deoxynivalenol (DON). The resistance to FHB and FSB in wheat was closely associated with expression of a plant cytochrome P450 gene in response to FHB pathogens and mycotoxins. Quantitative real-time polymerase chain reaction analyses showed that expression of nine defense-related genes in spikes and seedlings was induced by the fungal infection, in which a massive accumulation of a plant cytochrome P450 gene, CYP709C1, was clearly associated with the resistance reaction in both seedling and spike. The FHB-resistant Sumai3 accumulated 7-fold more P450 transcripts than did the FHB-susceptible Annong8455, while 84-fold more P450 transcripts were accumulated in the FSB-resistant Annong8455 than the FSB-susceptible Sumai3. A Fusarium strain with a disrupted Tri5 gene, which is not able to produce the first enzyme essential for trichothecene mycotoxin biosynthesis, also induced more P450 transcripts in FHB- and FSB-resistant cultivars. The fungal activation of the P450 gene was more profound in the FSB-resistant reaction than the FHB-resistant reaction relative to their susceptible counterparts. DON triggered a differential expression of the P450 gene with comparable patterns in spikes and seedlings in a resistance-dependent manner. These results may provide a basis for dissecting mechanisms underlying FHB and FSB resistance reactions in wheat and revealing functions of the cytochrome P450 in plant detoxification and defense.

Novel Multiplexer to Enable Multiple-Module Imaging with Adjustable High Spatial Resolution and Predetermined Display Bandwidth for Array Medical Imaging Systems

We describe a custom multiple-module multiplexer integrated circuit (MMMIC) that enables the combination of discrete Electron multiplying charge coupled devices (EMCCD) based imaging modules to improve medical imaging systems. It is highly desirable to have flexible imaging systems that provide high spatial resolution over a specific region of interest (ROI) and a field of view (FOV) large enough to encompass areas of clinical interest. Also, such systems should be dynamic, i.e. should be able to maintain a specified acquisition bandwidth irrespective of the size of the imaged FOV. The MMMIC achieves these goals by 1) multiplexing the outputs of an array of imaging modules to enable a larger FOV, 2) enabling a number of binning modes for adjustable high spatial resolution, and 3) enabling selection of a subset of modules in the array to achieve ROI imaging at a predetermined display bandwidth. The MMMIC design also allows multiple MMMICs to be connected to control larger arrays. The prototype MMMIC was designed and fabricated in the ON-SEMI 0.5μm CMOS process through MOSIS (www.mosis.org). It has three 12-bit inputs, a single 12-bit output, three input enable bits, and one output enable, so that one MMMIC can control the output from three discrete imager arrays. The modular design of the MMMIC enables four identical chips, connected in a two-stage sequential arrangement, to readout a 3×3 collection of individual imaging modules. The first stage comprises three MMMICs (each connected to three of the individual imaging module), and the second stage is a single MMMIC whose 12-bit output is then sent via a CameraLink interface to the system computer. The prototype MMMIC was successfully tested using digital outputs from two EMCCD-based detectors to be used in an x-ray imaging array detector system.Finally, we show how the MMMIC can be used to extend an imaging system to include any arbitrary (M×N) array of imaging modules enabling a large FOV along with ROI imaging and adjustable high spatial resolution.

The relationship between Chinese construction workers' HIV/AIDS-related knowledge, attitudes and behaviour: a structural equation model

This study explored the relationship between human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS)-related knowledge, attitudes and behaviour in migrant urban construction workers using structural equation modelling (SEM). A cross-sectional study was conducted among 428 male subjects on three building sites in Shenyang City. The SEM model of HIV/AIDS-related knowledge, attitudes and behaviour was built using LISREL version 8.5 and it fitted the data well, as shown by an adjusted goodness of fit index of 0.82 and a root mean square error of approximation of 0.094. Knowledge of HIV/AIDS was closely correlated with attitudes and behaviour. Age was an important factor affecting HIV/AIDS-related knowledge, attitudes and behaviour. These findings suggest that increasing HIV/AIDS-related knowledge could improve the attitude and behaviour of migrant urban construction workers, enabling them to avoid high-risk behaviour that increases the spread of HIV/AIDS. Any intervention used will need to take the important factor of age into consideration.

Reliability and validity testing of the SF-36 questionnaire for the evaluation of the quality of life of Chinese urban construction workers

The quality of life (QOL) of the Chinese 'floating' migrant population is of growing concern. Urban construction workers are the main migrant population in China, but there is little published research on their QOL. The reliability and validity of the 36-Item Short Form Health Survey (SF-36) questionnaire were assessed by conducting a population-based study of migrant construction workers in Shenyang, China. Two construction sites were randomly selected from each of the five districts of Shenyang City and 1200 copies of the questionnaire were distributed to rurally-registered, non-Shenyang workers aged > or = 16 years at these sites. A total of 1125 questionnaires were evaluated. The overall Cronbach's alpha coefficient of the SF-36 questionnaire was 0.821 while the respective Cronbach's alpha coefficient for each dimension was > 0.70. Results showed that the SF-36 questionnaire demonstrated good reliability and validity, and that it can be used to measure QOL among Chinese migrant urban construction workers.

The role of liver transplantation in the treatment of hepatic myelopathy: case report with review of the literature

BACKGROUND AND AIMS

Hepatic myelopathy (HM) is a rare neurological complication of chronic liver disease, causing progressive spastic paraparesis. Unlike hepatic encephalopathy, the conservative treatment of HM is usually considered inefficient. Although some scattered case studies have reported that the clinical symptoms and signs of patients with HM were improved after orthotopic liver transplantation (OLT), there have also been cases of failure. The aim of this study was to identify the role of OLT in the treatment of HM.

PATIENTS AND METHODS

We present two patients, who underwent OLT at the early stage after progressive HM had been diagnosed, gaining definite improvement of their neurological status within a relatively short time. In addition, we review all five similar cases that have hitherto been reported in English literature.

RESULTS

The clinical symptoms and signs of HM improved to variable degrees after OLT in most cases except one with a long HM history. The degree of improvement correlated with the time interval between the onset of the first symptoms of HM and OLT.

CONCLUSIONS

OLT represents an effective therapeutic option for HM. The duration of clinical manifestations of HM before OLT may be the main factor affecting the therapeutic outcome.

Mechanism of clofibrate hepatotoxicity: mitochondrial damage and oxidative stress in hepatocytes

Peroxisome proliferators have been found to induce hepatocarcinogenesis in rodents, and may cause mitochondrial damage. Consistent with this, clofibrate increased hepatic mitochondrial oxidative DNA and protein damage in mice. The present investigation aimed to study the mechanism by which this might occur by examining the effect of clofibrate on freshly isolated mouse liver mitochondria and a cultured hepatocyte cell line, AML-12. Mitochondrial membrane potential (Delta Psi(m)) was determined by using the fluorescent dye 5,5',6,6'-tetrachloro-1,1', 3,3'-tetraethyl-benzimidazolylcarbocyanine iodide (JC-1) and tetramethylrhodamine methyl ester (TMRM). Application of clofibrate at concentrations greater than 0.3 mM rapidly collapsed the Delta Psi(m) both in liver cells and in isolated mitochondria. The loss of Delta Psi(m) occurred prior to cell death and appeared to involve the mitochondrial permeability transition (MPT), as revealed by calcein fluorescence studies and the protective effect of cyclosporin A (CsA) on the decrease in Delta Psi(m). Levels of reactive oxygen species (ROS) were measured with the fluorescent probes 5-(and-6)-carboxy-2',7'-dichlorofluorescein diacetate (DCFDA) and dihydrorhodamine 123 (DHR123). Treatment of the hepatocytes with clofibrate caused a significant increase in intracellular and mitochondrial ROS. Antioxidants such as vitamin C, deferoxamine, and catalase were able to protect the cells against the clofibrate-induced loss of viability, as was CsA, but to a lesser extent. These results suggest that one action of clofibrate might be to impair mitochondrial function, so stimulating formation of ROS, which eventually contribute to cell death.

High level expression of human factor VIII in mammalian cells after retroviral-mediated gene transfer

OBJECTIVE

To develop a retroviral-mediated high efficient expression system of human coagulation factor VIII.

METHODS

The LNC-FVIIIBD retroviral vector was generated by cloning a human B-domain-deleted (760aa-1639aa) Factor VIII (FVIII) cDNA (FVIII cDNA BD) into the retroviral vector pLNCX. Several mammalian cell lines, including NIH3T3, CHO, Cos-7 and human hepatic cell line, L-02, were transduced with viral supernatant from the highest virus-producing PA317 clone. Antigen and coagulant activity of human FVIII in cell culture medium were measured by ELISA and a one-stage method, respectively. RT-PCR was performed for the detection of FVIIIBD mRNA.

RESULTS

Human FVIII was expressed in all four target cells, with the highest FVIII expression observed in NIH3T3. The coagulant activity of secreted FVIII was up to 1.6 U/10(6) cells.24 hrs-1, and the FVIII antigen was 500 ng/10(6) cells.24 hrs-1. FVIII coagulant activity and antigen expressed by transduced CHO cells were 0.12 U/10(6) cells.24 hrs-1 and 62.4 ng/10(6) cells.24 hrs-1, respectively. Human FVIII expression was relatively low in Cos-7 and L-02 cells. RT-PCR results demonstrated transcription of FVIII cDNA BD in the target cells.

CONCLUSIONS

The constructed retroviral vector was able to direct high level expression of human FVIII in various mammalian cell lines. It has potential utility in the future gene therapy for Hemophilia A.

Effects of All-Trans-Retinoic Acid and Arsenic Trioxide on the Hemostatic Disturbance Associated with Acute Promyelocytic Leukemia

To study the in vivo effect of all-trans-retinoic acid (ATRA) and arsenic trioxide (As(2)O(3)) on the expression of tissue factor (TF) and the other hemostatic disturbance, a series of parameters were measured either in bone marrow blasts or plasma from acute promyelocytic leukemia (APL) patients. The plasma parameters were measured by ELISA or chromogenic studies. The TF transcription was assessed using reverse transcription-polymerase chain reaction (RT-PCR) technique. The results indicated that the blast cell procoagulant activity (PCA), TF antigen of APL cell lysate, as well as the transcription of APL TF mRNA elevated at diagnosis, were reduced after ATRA or As(2)O(3) therapy. The plasma level of P-selectin, TF, thrombin-antithrombin complex (TAT), soluble fibrinmonomer complex, thrombomodulin (TM), tissue factor pathway inhibitor (TFPI), plasmin-antiplasmin complex, tissue plasminogen activator (t-PA) activity, urokinase plasminogen activator (u-PA) and its receptor (u-PAR), and D-dimer (D-D) significantly increased. Fibrinogen (Fg), antigen level of protein C (PC), plasminogen (PLG) activity, alpha(2)-plasminogen inhibitor activity (alpha(2)-PI), and plasminogen activator inhibitor (PAI) activity were decreased at diagnosis. The protein C activity (PC:A) and protein S (PS) remained unchanged. All the parameters were restored to normal ranges after complete remission (CR) except elevation of TF and TAT in both groups, as well as PC:A, PS, and t-PA in the ATRA group. In conclusion, there existed activation of platelets and consumption of anticoagulants as well as activation of coagulation and fibrinolytic system before treatment. Both ATRA and As(2)O(3) therapy downregulated the expression of TF mRNA, decreased the PCA and TF level in APL cells, significantly inhibited coagulation activation, corrected secondary hyperfibrinolysis and the other hemostatic abnormalities, and thus greatly improved the bleeding symptom in early stage of the treatment.

[Clinical significance of hemostatic molecular markers in acute leukemia]

OBJECTIVE

To study the changes of hemostatic molecular markers in acute leukemia (AL) for elucidating their clinical significance.

METHODS

A series of hemostatic molecular markers, including TF, TFPI, TAT, PAP, u-PA and u-PAR were measured in 82 acute leukemia.

RESULTS

The plasma levels of TF, TAT, u-PA and u-PAR were elevated significantly at diagnosis in all AL patients tested, while TFPI, PAP did only in AML. After treatment, TF and TAT remained high in AML, u-PA and u-PAR were still high in un-remission patients. PAP and u-PA remarkably elevated in patients with severe hemorrhage.

CONCLUSIONS

There existed hemostatic abnormality as well as hyperfibrinolysis, which varied with leukemia types and was ameliorated with clinical improvement. The measurement of TF, TAT and PAP may provide useful information for the diagnosis of DIC. u-PA and u-PAR may be considered as a useful indicator for prognosis. Patient with severe hemorrhage should be treated with antifibrinolysis drugs. The prevention of hypercoagulability after treatment should be kept in mind.

Refinement of the locus for autosomal dominant hereditary gingival fibromatosis (GINGF) to a 3.8-cM region on 2p21

Hereditary gingival fibromatosis (HGF, MIM 135300; approved gene symbol GINGF) is an oral disease characterized by enlargement of gingiva. Recently, a locus for autosomal dominant HGF has been mapped to an 11-cM region on chromosome 2p21. In the current investigation, we genotyped four Chinese HGF families using polymorphic microsatellite markers on 2p21. The HOMOG test provided evidence for genetic homogeneity, with evidence for linkage in four families (heterogeneity versus homogeneity test HOMOG, chi(2) = 0. 00). A cumulative maximum two-point lod score of 5.04 was produced with marker D2S390 at a recombination frequency of θ = 0 in the four linked families. Haplotype analysis localized the hereditary gingival fibromatosis locus within the region defined by D2S352 and D2S2163. This region overlaps by 3.8 cM with the previously reported HGF region. Single-strand conformation polymorphism and sequence analysis of the coding region of cytochrome P450 1B1 (CYP1B1) excluded it as a likely candidate gene.

[Hemostatic variations associated with acute leukemia: clinical and prognostic significance]

OBJECTIVE

To study the hemostatic abnormalities and their association with bleeding manifestation and prognosis in acute leukemia (AL) patients.

METHODS

A series of hemostatic parameters were determined in 93 cases of AL using ELISA or chromogenic assay.

RESULTS

At diagnosis, plasma levels of P-selectin, soluble fibrinomonomer complex (SFMC), thrombomodulin (TM), tissue plasminogen activator, D-dimer (D-D) were significantly elevated, but protein C antigen (PC:Ag), plasminogen (PLG), alpha(2)-antiplasmin (alpha(2)-PI) and plasminogen activator inhibitor (PAI) were decreased, and fibrinogen (Fg), PC activity (PC:A) and protein S (PS) were in normal range. All the above abnormalities returned to normal after complete remission (CR) except for PC:A and PC:Ag. Platelet counts, Fg, SFMC, PLG, alpha(2)-PI and D-D were significantly associated with hemorrhagic manifestations. TM, PS and PAI were related to prognosis.

CONCLUSION

There existed the consumption of platelets as well as the activation of coagulant, anticoagulant and fibrinolytic systems in AL, which was greatly improved after CR.

[Retroviral-mediated high efficient in vitro expression of human coagulation factor VIII]

OBJECTIVE

To develop a retroviral-mediated high efficient expression system of human coagulation factor VIII.

METHODS

The retroviral vector LNC-VIIIBD was generated by cloning a B-domain-deleted FVIII cDNA (760aa - 1639aa) into retroviral vector pLNCX. Several cell lines including NIH3T3, CHO, COS-7 and human hepatic cell line L-02 were infected with viral supernatant from the highest productive PA317 clones. The antigen and procoagulant activity of human FVIII in the cell culture medium were measured by ELISA assay and one-stage method, respectively. RT-PCR was performed for the detection of F VIII BD mRNA.

RESULTS

Human FVIII was expressed in all four target cells. The highest expression was observed in NIH3T3, the procoagulant activity of secreted FVIII was up to 1.6 U, and the FVIII antigen was 500 ng by 10(6) cells/ml in 24 hours, respectively.

CONCLUSION

The constructed retroviral vector was able to generate high level expression of human FVIII in some cell lines, and it might have potential utility in the gene therapy for Hemophilia A.

Development of cytotoxic cerebral edema in rats following intracaudatum injection of tACPD, an agonist of metabotropic glutamate receptors

OBJECTIVE

To explore the involvement of metabotropic glutamate receptors (mGluRs) in the formation of cerebral edema.

METHODS

Male Wistar rats weighing from 250 g to 300 g were used. Trans-1-aminocyclopentane-1, 3-diacarboxylic acid (tACPD), an agonist of mGluRs, was microinjected into the right caudatum. Brain water content was determined by a wet weight/dry weight technique and Na+, K+ and Ca2+ contents were measured by inductive Couple Plasma-9000 at 6 h, 24 h and 48 h post-injection. Extravasation of Evan's blue (EB) into the brain was determined as an indicator of disturbance in the blood-brain barrier (BBB) and endothelial cells. Histologic studies were performed under a Leitz microscope and a Philips EM208s electron microscope.

RESULTS

Dose-dependent and time-related increase of brain water was induced after tACPD (10, 50, 500 and 1000 nmol) injection. A significant increase in Na+ and K+ content but not in Ca2+ content was observed. EB extravasation showed no blue stain, indicating no increase in BBB permeability induced by tACPD-injection. Electron microscope study confirmed this finding and revealed remarkable swelling of astrocytes especially endfoot processes of astrocytes around capillaries at 6 h after tACPD-injection. In addition, all changes mentioned above occurred in both caudatum.

CONCLUSION

These results indicate that activation of mGluRs by tACPD injected into the caudatum induced cytotoxic brain edema and interfered with astrocyte K+ buffering. This may provide new clues for therapeutic intervention.

Caloric restriction prevents oxidative damage induced by the carcinogen clofibrate in mouse liver

Long-term caloric restriction in rodents is known to decrease levels of oxidative damage, which may contribute to an 'anti-ageing' effect. We show here that a shorter period (10 months) of caloric restriction had only small effects on levels of oxidative DNA and protein damage in the livers of mice, but completely attenuated increased oxidative damage caused by the carcinogen clofibrate. Since clofibrate is thought to exert its actions by increasing oxidative damage, our data suggest that 10 months of caloric restriction can increase the resistance of tissues to agents inducing oxidative stress. This may be an important factor in explaining how caloric restriction decreases cancer incidence.

[Mechanism of tissue factor expression on NB4 cells down-regulated by all-trans retinoic acid and arsenic trioxide]

OBJECTIVE

To investigate molecular mechanism of tissue factor (TF) expression on acute promyelocytic leukemia cell line NB4 cells down-regulated by all-trans retinoic acid (ATRA) and arsenic trioxide (As(2)O(3)).

METHODS

Cyclohexamide (CHX) inhibition test for de novo protein synthesis and actinomycin D (Act D) inhibition test for RNA synthesis were used to check the effect of ATRA on the TF expression. TF antigen of U937 cells transfected with pMSCV-PML-RARalpha treated with or without ATRA and As(2)O(3) was detected.

RESULTS

CHX treatment completely suppressed the down-regulation effect of ATRA on the TF mRNA expression, Act D inhibition test showed that half-life of TF mRNA in treated NB4 cells was shortened to about 30 min from that of around 60 min in untreated NB4 cells. The TF antigen contents in U937 cells transfected with pMSCV-PML-RARalpha were significantly higher than that in transfected U937 cells with retrovirus vector. Both ATRA and As(2)O(3) could down-regulate the TF antigen level in U937 cells transfected with or without PML-RARalpha.

CONCLUSION

The modulation of the TF mRNA expression in NB4 cells by ATRA might be indirect. TF mRNA destabilization was involved in the TF regulation process mediated by ATRA. Elevated TF antigen level in U937 cells transfected with pMSCV-PML-RARalpha may be related to the fusion protein PML-RARalpha. The down-regulation effect of ATRA and As(2)O(3) on the TF expression of U937 cells might not involve the fusion protein.

[Effects of holothuria glycosaminoglycan on the expression of tissue factor and thrombomodulin in stimulated endothelial cells]

OBJECTIVE

To study the mechanism of antithrombotic effects of holothuria glycosaminoglycan (GAG).

METHODS

Endothelial cells from human umbilical vein which were pre-induced with 1 mg/L lipopolysaccharide, were treated by GAG (1 mg/L, 5 mg/L, and 10 mg/L, respectively) and 5 mg/L heparin as a control for 6 hours. Procoagulant activity (PCA), the expressions of tissue factor (TF) antigen and thrombomodulin (TM) antigen and their mRNA transcriptions were investigated.

RESULTS

GAG could down-regulate the expression of TF antigen and mRNA, up-regulate the expression of TM antigen and mRNA, down-regulate the PCA of stimulated endothelial cells.

CONCLUSION

Down-regulating TF expression and up-regulating TM expression of stimulated endothelial cells may be one of the mechanisms of GAG antithrombosis.

Hemostatic abnormalities associated with acute promyelocytic leukemia and corrective effects of all-trans-retinoic acid or arsenic trioxide treatment

OBJECTIVE

To study in vivo effect of all-trans-retinoic acid (ATRA) or arsenic trioxide (As2O3) on the expression of tissue factor (TF) and the hemostatic disorders, a series of parameters were measured in bone marrow blasts and plasma from acute promyelocytic leukemia (APL) patients.

METHODS

The plasma variables were measured by ELISA or chromogenic study. The TF transcription was assessed using reverse transcription-polymerase chain reaction technique (RT-PCR).

RESULTS

The blast cell procoagulant activity (PCA), TF antigen of APL cell lysates, as well as the transcription of APL TF mRNA elevated at diagnosis, were reduced after ATRA or As2O3 therapy. The plasma level of platelet alpha-granular membrane protein-140, soluble fibrinomonomer complex, thrombomodulin, tissue plasminogen activator and D-dimer significantly increased, fibrinogen, antigen level of protein C, plasminogen, alpha 2-plasminogen inhibitor and plasminogen activator inhibitor decreased at diagnosis, were restored to normal after complete remission but protein C activity and protein S remained elevated in ATRA group.

CONCLUSIONS

There existed activation of platelets and consumption of anticoagulants as well as activation of coagulation and fibrinolytic system before treatment. Both ATRA and As2O3 therapy down-regulated the expression of TF mRNA, decreased the PCA and TF level in APL cells, inhibited coagulation activation, secondary hyperfibrinolysis and recorrected other hemostatic abnormalities, thus greatly improved the bleeding symptom in early stage of the treatment.

Mitochondrial damage by the "pro-oxidant" peroxisomal proliferator clofibrate

Clofibrate is a peroxisome proliferator that can cause hepatic cancer in rodents. It has been suggested that oxidative damage is involved in this hepatocarcinogenesis, although the data are conflicting. We confirmed that clofibrate causes oxidative damage in nuclei from the livers of mice treated with this substance, measured both as protein carbonyls and levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in DNA. In addition, clofibrate also affects mitochondria, causing elevated levels of carbonyls and 8-OHdG, increased state 4 respiration and decreased adenosine triphosphatase (ATPase) activity. No evidence for clofibrate-induced lipid peroxidation in mitochondria was obtained. We propose that mitochondria may be a major target of injury and a source of oxidative stress in clofibrate-treated animals.

[Molecular characterization of genetic defects in hemophilia in Shanghai]

OBJECTIVE

To detect gene mutations in hemophilia A in Shanghai.

METHODS

PCR, denaturing gradient gel electrophoresis (DGGE) and DNA sequencing were used. Fifty Chinese cases of hemophilia A without intron 22 inversion, including 24 severe, 9 moderate and 17 mild cases, were screened. Genomic DNA was amplified using GC-clamped primers covering all the exons and flanking intron regions, excluding the middle portion of extron 14 encoding the B domain, but including the thrombin cleavage sites at AA740 and 1689. The amplified GC-clamped PCR fragments were then electrophoresed on DGGE. The abnormal bands were sequenced.

RESULTS

Eleven different mutations were identified, including 5 nonsense mutations, 5 missense mutations and one small deletion. Among them, 3 mutations, 466Lys (AAG)-Thr (ACG), 719Tyr (TAC)-Stop (TAG) and 312Ile (ATC)-xxC have not been reported before.

CONCLUSION

Apart from intron 22 inversion, most gene mutations in hemophilia A were point mutations resulted from single base substitution. Generally the genetic defects correspond to the clinical manifestations.

[Clinical study on the antithrombotic effects of Holothuria ldeucospilota acidic mucopolysaccharide]

OBJECTIVE

To study the antithrombotic effects of Holothuria Ldeucospilota Acidic Mucopolysaccharide (HLAM).

METHODS

A series of variables were observed before and after treatment with HLAM in normal middle-aged subjects and patients recovering from cerebral embolism or suffering from ischemic heart disease, each of which were divided into two groups according to the dosage administered (60 mg/d and 120 mg/d).

RESULTS

The fat metabolism was enhanced in addition to the anticoagulant and the blood viscosity reducing effects. No side-effect was found.

CONCLUSION

HLAM is a promising drug for antithrombotic therapy.

[Drug addiction--origin, development and pharmacological intervention]

The present essay on drug addiction deals, under the escort of empirical knowledges emanating from medico-legal toxicology, mainly with the behavioural, neurobiological, forensic and pharmacotherapeutical aspects of drug seeking and taking behaviour. The article emphasizes the idea that treatment of drug dependence [including that of the associated diseases and complications] should be performed according to the specific pharmacological and toxicological properties of the drugs involved. Furthermore, the treatment of drug dependence should be carried out in agreement with the individual needs of the patient, and in concordance with the multiple factors involved in the development and maintenance of drug addiction.

Poly (alpha 2,8-deaminoneuraminic acid) is expressed in lung on a single 150-kDa glycoprotein and is an oncodevelopmental antigen

Homopolymers of alpha 2,8-linked N-acetylneuraminic acid [poly(alpha 2,8-Neu5Ac)] of the neural cell adhesion molecule NCAM have been shown to be temporally expressed during lung development and represent a marker for small cell lung carcinoma. We report the presence of a further polysialic acid in lung that consists of oligo/polymers of alpha 2,8-linked deaminoneuraminic acid residues [poly (alpha 2,8-KDN)], as detected with a monoclonal antibody in conjunction with a specific sialidase. Although the various cell types forming the bronchi, alveolar septs, and blood vessels were positive for poly (alpha 2,8-KDN) by immunohistochemistry, this polysialic acid was found on a single 150-kDa glycoprotein by immunoblot analysis. The poly(alpha 2,8-KDN)-bearing glycoprotein was not related to an NCAM protein based on immunochemical criteria. The expression of the poly (alpha 2,8-KDN) was developmentally regulated as evidenced by its gradual disappearance in the rat lung parenchyma commencing 1 week after birth. In adult lung the blood vessel endothelia and the smooth muscle fibers of both blood vessels and bronchi were positive but not the bronchial and alveolar epithelium. The poly (alpha 2,8-KDN)-bearing 150-kDa glycoprotein became reexpressed in various histological types of lung carcinomas and cell lines derived from them and represents a new oncodevelopmental antigen in lung.

Spike waves and synaptic ultrastructure in human epileptic brains

OBJECTIVE

To find morphological changes of synapses related to the spike discharge by observation on ultrastructures of the EEG spike foci of cerebral cortexes.

MATERIAL AND METHODS

The cerebral cortexes were obtained surgically from the EEG spike (recorded by flaky silver electrodes on the surface of cortexes) foci and nonspike areas within the limits of the brain tissue that would be removed in 20 cases of human epilepsy, and were processed for transmission electron microscopic (TEM) observation.

RESULTS

In the spike foci, presynaptic terminals of axospinal asymmetric synapses were obviously swollen but postsynaptic spines were relatively unaffected. In these synapses, the synaptic vesicles remarkably decreased in number and accumulated predominantly at the presynaptic membranes or aggregated. Similar changes were observed in the presynaptic terminals of the axospinal asymmetric synapses in the nonspike areas but were of milder degree than in the spike foci.

CONCLUSION

Axospinal asymmetric synapses may release a large quantity of excitatory neurotransmitters, which may result in epileptic abnormal electric activities during seizure.

Occurrence of poly(alpha2,8-deaminoneuraminic acid) in mammalian tissues: widespread and developmentally regulated but highly selective expression on glycoproteins

In tissues of higher organisms homopolymers of alpha2,8-linked N-acetylneuraminic acid can be found as a posttranslational modification on selected proteins. We report here the discovery of homopolymers of alpha2,8-linked deaminoneuraminic acid [poly(alpha2,8-KDN)] in various tissues derived from all three germ layers in vertebrates including mammals. The monoclonal antibody kdn8kdn in conjunction with a bacterial KDNase permitted the detection of poly(alpha2,8-KDN) by immunohistochemistry and immunoblotting. Further evidence for the existence of poly(alpha2,8-KDN) was obtained by gas/liquid chromatography. The poly(alpha2,8-KDN) glycan was detectable in all tissues studied with the exception of mucus-producing cells present in various organs, the extracellular matrix, and basement membranes. However, in certain organs such as muscle, kidney, lung, and brain its expression was developmentally regulated. Despite its widespread tissue distribution, the poly(alpha2,8-KDN) glycan was detected on a single 150-kDa glycoprotein except for a single >350-kDa glycoprotein in kidney, which makes it most distinctive among polysialic acids. The ubiquitous yet selective expression may be indicative of a general function of the poly(alpha2,8-KDN)-bearing glycoproteins.

Letters

SHEEPSKINS AND PRESSURE SORE PREVENTION PROFESSIONAL SOCIETIES TREATMENT OF DEGLOVING INJURY ISCHAEMIC-INDUCED HYPOXIA.

The effects of hyperbaric oxygen on cultured fibroblasts

The effect of hyperbaric oxygen on the proliferative and synthetic responses of fibroblasts derived from wounds and normal skin was examined in this study. Hyperbaric oxygen treatment resulted in a slight decrease in fibroblast proliferation but an increase in the synthesis of extracellular matrix components. Relating these results to the process of wound healing suggests that hyperbaric oxygen therapy would increase the matrix:cell ratio, which could have important consequences for repair processes such as cell migration and regulation of cell activity. There was no apparent difference in the response to hyperbaric oxygen of fibroblasts derived from different sources.

Dynamic investigation on chromosome aberration of a human retinoblastoma cell line So-Rb50

G-banding and karyotype analyses of cells in seventeen passages of SO-Rb50 during a long period of culture for about four years were performed. Three chromosome markers 13q14-, 1p36+ and 12p13+ were found. Cells possessed 13q14- reduced to zero after the 200th passage while 1p+ and 12p+ cells increased to 100% after 30 and 200 passages respectively. Abnormal chromosomes, ring chromosomes, chromosome radiuses and double minutes were also observed. These chromosomal changes were more often seen before the 200th passage. The significance of these changes are discussed.

Mortality and incidence of bladder cancer in benzidine-exposed workers in China

We examined bladder cancer mortality and incidence to 1981 in 1,972 workers employed in benzidine-exposed jobs in Tianjin, Shanghai, and Jilin, China, between 1972 and 1977, and in 1,974 unexposed workers employed during the same time period. In comparison to general population rates, in the benzidine-exposed group the ratio of observed to expected deaths (SMR) was 17.5 (95% C.I.: 7.5-34.5) and the ratio of observed to expected incident cases (SIR) was 25.0 (95% C.I.: 16.9-35.7). No excess was noted in the unexposed group. The 25-fold increase in bladder cancer incidence in the exposed group was related to level of exposure, with the SIR rising from 4.8 for low exposure to 36.2 for medium exposure, and 158.4 for high exposure. Risks were elevated both for producers of benzidine (SIR = 45.7; 95% C.I.: 20.9-86.8) and for users (SIR = 20.9; 95% C.I.: 12.9-32.0) of benzidine dyes. Benzidine-exposed workers who smoked tobacco had a 31-fold risk (95% C.I.: 20.4-46.4), while non-smoking workers had an 11-fold risk (95% C.I.: 3.6-25.8), suggestive of a multiplicative relationship between these two carcinogens.