Fibrin sealant matrix supports outgrowth of peripheral sensory axons

It has been suggested that fibrin-based matrix has an important role during the early stage of nerve regeneration. A fibrin sealant matrix, which was made by combining diluted human fibrinogen and thrombin, was used as a substrate for in vitro elongation of neurites and in vivo regeneration of axons. In the in vitro experiment, dissociated embryonic chick sensory neurons were cultured on dishes coated with fibrin sealant matrix and compared with the solution of thrombin/calcium chloride, or with poly-D-lysine (PDLctr). After 16 hours, cultures were stained immunohistochemically with a monoclonal antineurofilament antibody. The neurons survived well, and an abundant network of neurites, qualitatively similar to that on PDLctr, developed on the fibrin sealant matrix. The percentage of neurons that had outsprout at 16 hours was the same both in the fibrin sealant matrix and PDLctr groups. By contrast, all the neurons plated on the dishes treated with the solution of thrombin/calcium chloride were dead after 16 hours. Immunohistochemical staining of fibrinogen also showed an even distribution of fibrin matrix over the culture dishes. For the in vivo experiments, 48 rat sciatic nerves were cut and reconnected with two epineurial stitches. Fibrin sealant matrix or phosphate buffer solution was applied to the transsected and repaired region. Pinch reflex test showed that the regeneration of the leading sensory fibre was significantly faster in the fibrin sealant matrix group than in the control group at 3 and 4 days. These results indicate that fibrin sealant matrix accelerates regeneration of axons in vivo during the early phase, and also supports elongation of neurites in vitro.

New bioactive monotetrahydrofuran Annonaceous acetogenins, annomuricin C and muricatocin C, from the leaves of Annona muricata

The leaves of Annona muricata have yielded two additional monotetrahydrofuran Annonaceous acetogenins, annomuricin C [1] and muricatocin C [2]. Compounds 1 and 2 each possess five hydroxyl groups; two hydroxyl groups are at the C-10/C-11 and C-10/C-12 positions in 1 and 2, respectively. The absolute configurations of 1 and 2, except for positions C-10 and C-11 or C-12, were determined by Mosher ester methodology. The C-10/C-11 and C-10/C-12 acetonides (1c, 2c) suggested relative stereochemistry and significantly enhanced the cytotoxicities against the A-549 human lung and the MCF-7 human beast solid tumor cell lines. One known monotetrahydrofuran acetogenin, gigantetronenin, not described previously from this plant, was also found.

Two new cytotoxic monotetrahydrofuran Annonaceous acetogenins, annomuricins A and B, from the leaves of Annona muricata

The leaves of Annona muricata have yielded eight monotetrahydrofuran Annonaceous acetogenins. Two of them, annomuricins A [1] and B [2], whose chemical structures were deduced by ms, nmr, ir, and uv spectral and chemical methods, are novel and unusual. Compounds 1 and 2 each possess five hydroxyl groups; two hydroxyl groups are vicinal, with the vicinal group of 1 threo and that of 2 erythro. The absolute configurations of 1 and 2 were determined by Mosher ester methodology. Six monotetrahydrofuran acetogenins, previously described in the seeds, were found in the leaves; these are gigantetrocin A, annonacin-10-one, muricatetrocins A and B, annonacin, and goniothalamicin.

Muricatocins A and B, two new bioactive monotetrahydrofuran Annonaceous acetogenins from the leaves of Annona muricata

The leaves of Annona muricata have yielded the novel monotetrahydrofuran Annonaceous acetogenins, muricatocins A [1] and B [2]. Each compound possesses five hydroxyl groups, with two hydroxyl groups at the C-10 and C-12 positions. The absolute configurations of 1 and 2 (except for positions C-10 and C-12) were determined by Mosher ester methodology. The C-10, C-12 acetonides (1c, 2c) suggested relative stereochemistry and significantly enhanced cytotoxicity against the A-549 human lung tumor cell line. Three known monotetrahydrofuran acetogenins, annonacin A, (2,4-trans)-isoannonacin, and (2,4-cis)-isoannonacin, were also found.

Molecular characterization of the 3' terminus of the simian hemorrhagic fever virus genome

The 3' end of the simian hemorrhagic fever virus (SHFV) single-stranded RNA genome was cloned and sequenced. Adjacent to the 3' poly(A) tract, we identified a 76-nucleotide noncoding region preceded by two overlapping reading frames (ORFs). The ultimate 3' ORF of the viral genome encodes the capsid protein, and the penultimate ORF encodes the smallest SHFV envelope protein. These two ORFs overlap each other by 26 nucleotides. Northern (RNA) blot hybridization analyses of cytoplasmic RNA extracts from SHFV-infected MA-104 cells with gene-specific probes revealed the presence of full-length genomic RNA as well as six subgenomic SHFV-specific mRNA species. The subgenomic mRNAs are 3' coterminal. In its virion morphology and size, genome structure and length, and replication strategy, SHFV is most similar to lactate dehydrogenase-elevating virus, equine arteritis virus, and porcine reproductive and respiratory syndrome virus.

Venezenin: a new bioactive Annonaceous acetogenin from the bark of Xylopia aromatica

Asimicin and a new cytotoxic Annonaceous acetogenin, venezenin [1], were isolated from the bark of Xylopia aromatica by bioactivity-directed fractionation using lethality to brine shrimp. Compound 1 represents an unusual type of C37 Annonaceous acetogenin, lacking either tetrahydrofuran (THF) or epoxide rings and possessing a double bond located two methylenes away from a vicinal diol in the hydrocarbon chain. The structure of 1 was elucidated by 1H- and 13C-nmr, COSY, single-relayed COSY, and by HMBC techniques, and derivatization. Annomontacin 10-one [6] and 18/21-cis-annomontacin-10-one [7], two semi-synthetic mono-THF acetogenins were prepared from 1. These acetogenins showed cytotoxicity, comparable or superior to adriamycin, against three human solid tumor cell lines. Reduction of the 10-keto of 1 to the racemic OH-10 derivative enhanced the bioactivity, as did the conversion of 1 to 6 and 7. Venezenin [1], like other Annonaceous acetogenins, showed inhibition of oxygen uptake by rat liver mitochondria and demonstrated that the THF ring may not be essential to this mode of action.

Meliavolkenin, a new bioactive triterpenoid from Melia volkensii (Meliaceae)

Meliavolkenin, a new triterpene with an apotirucallane skeleton, has been isolated from the root bark of Melia volkensii (Meliaceae) by bioactivity-directed fractionation using the brine shrimp lethality test. The structure has been elucidated using spectral and chemical data. The relative stereochemistries were determined by reduction and acetonide derivations, and the ring conformations were analyzed using the results of NOESY experiments. Meliavolkenin was bioactive in the brine shrimp lethality test and gave moderate cytotoxicities against three human solid tumor lines.

A role for protein kinase C-mediated phosphorylation in eliciting glucagon desensitization in rat hepatocytes

An immobilized hepatocyte preparation was used to show that both vasopressin and glucagon could desensitize the ability of glucagon to increase intracellular cyclic AMP concentrations. This process was not dependent on any influx of extracellular Ca2+ and was not mediated by any rise in the intracellular level of Ca2+. The protein kinase C-selective inhibitors chelerythrine, staurosporine and calphostin C acted as potent inhibitors of the desensitization process but with various degrees of selectivity regarding their ability to inhibit the desensitizing actions of glucagon and vasopressin. The protein phosphatase inhibitor okadaic acid was just as potent as vasopressin and glucagon in causing desensitization. Treatment of hepatocyte membranes with alkaline phosphatase restored to near control levels the ability of glucagon to stimulate adenylate cyclase activity in membranes from both glucagon- and vasopressin-treated (desensitized) hepatocytes. It is suggested that the desensitization of glucagon-stimulated adenylate cyclase activity involves a reversible phosphorylation reaction with the likely target being the glucagon receptor itself.

Analysis of simian hemorrhagic fever virus (SHFV) subgenomic RNAs, junction sequences, and 5' leader

Full-length simian hemorrhagic fever virus (SHFV) genome RNA (about 15 kb in length) and six subgenomic RNAs, ranging in size from 0.65 to 4.7 kb, were detected by Northern blot hybridization in MA104 cytoplasmic extracts with a 3' genomic antisense probe. The 5' regions of the two smallest subgenomic RNAs (RNAs 6 and 7) were cloned and sequenced. Sequence analysis indicated that these two RNAs contained a common 5' leader sequence joined to the subgenomic RNA bodies via a highly conserved junction sequence; the junction sequence of RNA 7 was 5'-TTAACC-3', while that of RNA 6 was 5'-TCAACC-3'. The complete 5' leader sequence (208 nt) was obtained from genomic RNA. The genomic 5' junction sequence is identical to that of RNA 7. Northern blot hybridization with an antisense 5' leader probe confirmed the presence of the complete leader sequence in all six species of subgenomic RNA. In its virion morphology, genome size, gene order, and replication strategy, SHFV is most similar to viruses such as equine arteritis virus, lactate dehydrogenase-elevating virus, and Lelystad virus/porcine respiratory and reproductive syndrome virus.

The analysis of disparity evoked potentials by a new form of static random-dot stereograms

PURPOSE

A new form of static random-dot stereograms free of monocular clues was designed as stimulus to elicit disparity evoked potentials.

METHODS

Disparity evoked potentials were recorded in 40 stereo-normal subjects. The stimulator was a white-black static random-dot stereograms generated by a computer and had no monocular clues. Every subject was tested in disparity stimulus, zero disparity stimulus, monocular stimulus and wearing prism condition.

RESULTS

A characteristic wide positive wave at about 250 ms was consistently recorded in disparity stimulus, which may be regarded as evidence of the presence of stereopsis. In contrast, recordings for zero disparity stimulus, monocular vision, stimulus and wearing prism condition all demonstrated a markedly difference from recording for disparity stimulus.

Specific suppression by prostaglandin E2 of activation-induced apoptosis of human CD4+CD8+ T lymphoblasts

Receptors (Rs) for prostaglandin E2 (PGE2) of the EP2 subtype are expressed at high levels in rodent and human thymuses, with preferential localization on immature thymocytes. Human cultured lymphoblasts of the Tsup-1 line express CD4 and CD8 but only a low level of CD3, typical of immature thymocytes, and bear EP2-type Rs for PGE2 that were identified by binding of [3H]PGE2 and Ab to recombinant EP2Rs, and by cAMP responses to PGE2. PGE2 protected Tsup-1 cells from apoptosis initiated by diverse stimuli, including mitogenic lectins and anti-Fas or anti-CD3 plus anti-CD28 Abs, but not ionomycin, as assessed by suppression of both fragmentation of [3H]thymidine-labeled DNA and appearance of free 3'-OH ends of cleaved DNA. An EP2R-selective synthetic agonist also significantly suppressed lectin-induced apoptosis of Tsup-1 cells. Phosphodiesterase inhibition synergistically enhanced PGE2-induced increases in cAMP and decreases in apoptosis in parallel, which suggests that the EP2R-specific protective effect of PGE2 is mediated predominantly by cAMP suppression of apoptosis. Dibutyrylcyclic AMP alone protected Tsup-1 cells against lectin-induced apoptosis, but the maximal effect was less than that for PGE2. The thromboxane A2 mimetic U46619 initiated apoptosis of Tsup-1 cells that was suppressed significantly by PGE2. Immune negative selection of immature thymocytes thus may be regulated by opposing effects of endogenous eicosanoids that include destruction by thromboxane A2 and protection by PGE2.

A new cytotoxic dihydroxy sterol from the soft coral Alcyonium patagonicum

A new sterol, 24-methylenecholest-4-ene-3 beta,6 beta-diol [1] was isolated from the soft coral Alcyonium patagonicum collected from the South China Sea. Its structure was determined by spectral analysis. Compound 1 was cytotoxic against the P-388 cell line with an IC50 value of 1 microgram/ml.

Diarrhoea in piglets and monkeys experimentally infected with Balantidium coli isolated from human faeces

Ten piglets and four monkeys free from Balantidium were dosed with human faecal homogenate which contained 1.2 x 10(4)-4.8 x 10(4) B. coli cysts. The infection resulted in severe diarrhoea in piglets 1-6 and hydrocortisone-treated monkeys 1-2, moderate diarrhoea in piglets 7-10 and a subclinical infection in monkeys 3-4. In piglets 1-3 and monkeys 1-2, heavy infection of the intestinal mucosa extended from the terminal ileum to the rectum and the mucosa was severely damaged. In piglets 4-10, infection was heavy in the large intestine with moderate mucosal damage.

Specific suppression by prostaglandin E2 of activation-induced apoptosis of human CD4+CD8+ T lymphoblasts

Receptors (Rs) for prostaglandin E2 (PGE2) of the EP2 subtype are expressed at high levels in rodent and human thymuses, with preferential localization on immature thymocytes. Human cultured lymphoblasts of the Tsup-1 line express CD4 and CD8 but only a low level of CD3, typical of immature thymocytes, and bear EP2-type Rs for PGE2 that were identified by binding of [3H]PGE2 and Ab to recombinant EP2Rs, and by cAMP responses to PGE2. PGE2 protected Tsup-1 cells from apoptosis initiated by diverse stimuli, including mitogenic lectins and anti-Fas or anti-CD3 plus anti-CD28 Abs, but not ionomycin, as assessed by suppression of both fragmentation of [3H]thymidine-labeled DNA and appearance of free 3'-OH ends of cleaved DNA. An EP2R-selective synthetic agonist also significantly suppressed lectin-induced apoptosis of Tsup-1 cells. Phosphodiesterase inhibition synergistically enhanced PGE2-induced increases in cAMP and decreases in apoptosis in parallel, which suggests that the EP2R-specific protective effect of PGE2 is mediated predominantly by cAMP suppression of apoptosis. Dibutyrylcyclic AMP alone protected Tsup-1 cells against lectin-induced apoptosis, but the maximal effect was less than that for PGE2. The thromboxane A2 mimetic U46619 initiated apoptosis of Tsup-1 cells that was suppressed significantly by PGE2. Immune negative selection of immature thymocytes thus may be regulated by opposing effects of endogenous eicosanoids that include destruction by thromboxane A2 and protection by PGE2.

Stable SV40-transformation and characterisation of some DNA repair properties of fibroblasts from a trichothiodystrophy patient

To characterize nucleotide excision repair properties of cells from trichothiodystrophy (TTD) patients genetically-related to the xeroderma pigmentosum (XP) group D, TTD skin fibroblasts from two unrelated patients (TTD1VI and TTD2VI) belonging to the TTD/XPD group were transformed with a plasmid containing SV40 large T antigen-coding sequences and some DNA repair properties, such as unscheduled DNA synthesis (UDS), UV-survival, in vitro repair synthesis of cell extracts and reactivation of UV-irradiated reporter plasmid were studied. Results showed that: a) both untransformed and transformed TTD cells present a reduced UV-survival, compared to wild-type cells, but at significantly less reduced levels than XP-D cells; b) reduced repair activities were detected in both TTD and XP-D transformed cells by using in vitro cell free extract repair and reactivation of UV-irradiated plasmid procedures, and these relative reduced extents correlated with respective UV-survival; c) surprisingly, near wild-type UDS levels were detected in TTD2VILas transformed cells at different passages after the crisis, suggesting a phenotypic reversion of this transformed cell line; d) fluoro-cytometric analysis of TTD2VILas cells revealed a strong increase of a cell population containing a DNA amount more than twice as high than that of untransformed cells; finally, e) when UDS data were normalized to the DNA content in TTD2VILas cells, it appeared that the repair efficiency was only slightly higher than in untransformed cells. This implies that in transformed cells DNA repair properties should be evaluated, taking into account additional parameters. We obtained an immortalized TTD cell line which maintains DNA repair properties similar to those of parental untransformed cells and may be used to characterize the TTD defect at genetic, molecular and biochemical levels.

Isoforms of the EP3 subtype of human prostaglandin E2 receptor transduce both intracellular calcium and cAMP signals

The EP3 subtype of prostaglandin E2 receptor transduces diverse physiological responses in mammalian tissues through signaling pathways coupled to heterotrimeric G proteins. Distinct cDNA clones encoding five isoforms of the EP3 receptor were isolated from a human uterus cDNA library. The human EP3 receptor isoforms designated hEP3-I, I', II, III, and IV are derived from alternative RNA splicing and differ only in the distal sequences of their carboxyl-terminal cytoplasmic tails. The unique cytoplasmic tails consist of 31 amino acids for isoforms I and I', 29 for II, 6 for III, and 15 for IV. When stably expressed in CHO cell transfectants, all isoforms exhibited similar EP3-specific binding of [3H]-PGE2 and PGE2 analogs. The EP3-selective agonist M&B 28767 both decreased the intracellular cAMP concentration ([cAMP]i) and increased the intracellular concentration of calcium ([Ca2+]i) with quantitative differences among different isoforms, but none mediated an increase in [cAMP]i. Pertussis toxin treatment completely blocked the decrease in [cAMP]i, but not the increase in [Ca2+]i evoked by M&B 28767. PGE2-induced desensitization of [3H]PGE2 binding by isoforms III and IV was rapid and transient, whereas that by isoform II was slow and persistent. Reverse transcription-PCR amplification of EP3 receptor messages in human kidney and uterine tissue RNA detected expression of all isoforms with different abundancies. The dual signal transduction pathways and distinctive tissue distribution of isoforms of the EP3 receptor are consistent with its mediation of diverse functions of PGE2.

[Studies on MDA and MDA/MDAa in patients with retinitis pigmentosa]

With fluorimetry, the concentration of malondialdehyde (MDA) and the ratio of MDA before and after the blood platelets activated (MDA/MDAa) were determined in patients with retinitis pigmentosa (RP). The results showed the above two parameters were statistically higher than those of the normal controls, which indicated the superoxidation metabolism increased and the blood was in a state of hypercoagulation in RP patients. The reasons for the results and their roles in RP disease were discussed. Treatments with anti-lipid, and anti-coagulation drugs combined with Chinese medicines were suggested.

Intrapleural production of interleukin 6 during mesothelioma and its modulation by gamma-interferon treatment

In vivo production of monokines was analyzed in 17 human malignant pleural mesotheliomas. High concentrations of interleukin 6 (IL-6) were detected in pleural effusions, contrasting with low levels of IL-1 beta and tumor necrosis factor alpha. This production arose from malignant cells, as shown by immunochemical analysis of pleural cells and by production of IL-6 by mesothelial cell lines. Intrapleural administration of recombinant human gamma-interferon to six patients led to a marked decrease in intrapleural IL-6 concentrations in all cases. This treatment was associated with in situ activation of macrophages and cytotoxic T-lymphocytes, as indicated by increased intrapleural neopterin and soluble CD8 concentrations. In vitro gamma-interferon had no effect on the production of IL-6 by mesothelial cell lines but decreased the growth of 3 of 6 mesothelioma cell lines. These results indicate that systemic manifestations of malignant mesothelioma, including fever, cachexia, and thrombocytosis may be related to the production of IL-6 by malignant cells, and that local gamma-interferon infusion may reduce this production by stimulating antitumoral immunity and/or by directly decreasing the proliferation of malignant cells.

A noninvasive functional evaluation following peripheral nerve repair with electromyography in a rat model

A new bipolar surface electrode array was designed and constructed for a noninvasive "closed" functional evaluation with electromyography following sciatic nerve transection in a rat model. This "closed" method was compared with a conventional one-shot "open" measurement. Nerve conduction velocity and distal latency were calculated. Data obtained from the recordings from different animals as well as from the same animal at different points in time yielded excellent reproducibilities. There is no difference in the mean values whether nerve conduction velocity and distal latency are obtained by "closed" or "open" measurements. Correlation was significant (p < 0.01; rNCV = 0.77, rDL = 0.63) between these two methods. The results lead to the conclusion that the noninvasive functional evaluation with the parameters of nerve conduction velocity and distal latency introduced in the present study could be employed as a reliable method for serial functional evaluations following nerve transection in a long-term study in a rat model.

Immunocytochemical characterization of cell lines from human malignant mesothelioma: characterization of human mesothelioma cell lines by immunocytochemistry with a panel of monoclonal antibodies

A panel of nine monoclonal antibodies was used to characterize human mesothelioma cell lines that we established from human malignant mesothelioma. The antigens detected were cytokeratin, vimentin, epithelial membrane antigen, carcinoembryonic antigen, Leu-M1 (CD15), desmin, factor VIII-related antigen (von Willebrand factor antigen), OV632, and ME1, a specific monoclonal antibody directed against human malignant mesothelioma. The technique used was the alkaline phosphatase anti-alkaline phosphatase method. All 30 cell lines, either epithelial, sarcomatous, or mixed, showed strong reactivity with cytokeratin and vimentin antibodies. None of the cell lines demonstrated any reactivity with carcinoembryonic antigen, Leu-M1, or factor VIII antibodies; moreover, all of 22 cell lines studied were positive for ME1 antibody and 10 of 12 cell lines studied were positive for OV632. Some interesting features were noted: only two of the 30 cell lines presented a weak positive staining with epithelial membrane antigen, and nine of 19 cell lines tested demonstrated a cytoplasmic staining pattern with desmin antibody. These results show that established human mesothelioma cell lines still possess the immunocytochemical characteristics that are basically consistent with the immunohistochemical features described in tumor tissues of malignant mesothelioma. These characteristics can be used to identify the mesothelioma cells grown from human malignant mesothelioma. Hence, the mesothelioma cell lines will provide a useful tool for the investigation of the cell biology of the tumor and the mechanisms of mesothelial cell transformation, as well as the in vitro evaluation of the effects of some drugs in order to develop new therapies for malignant mesothelioma.

Kneglomeratanol, kneglomeratanones A and B, and related bioactive compounds from Knema glomerata

One new phenylalkyl phenol, kneglomeratanol [1], and two new acetophenones, kneglomeratanones A [2] and B [3], together with ten known compounds, 3-(12'-phenyldodecyl)-phenol [4], 3-(10'-phenyldecyl)-phenol [5], 5-pentadecylresorcinol [6], 5-(10'-phenyldecyl)-resorcinol [7], 5-(12'-phenyldodecyl)-resorcinol [8], 2,4-dihydroxy-6-(10'-phenyldecyl)-acetophenone [9], 2-hydroxy-6-(12'-phenyldodecyl)-benzoic acid [10], formononetin, biochanin A, and 8-O-methylretusin, have been isolated from the stem bark of Knema glomerata. Brine shrimp lethality was used for the activity-directed chromatographic fractionations. All of these compounds showed moderate but significant toxicities to three human tumor cell lines and inhibited the growth of crown gall tumors on discs of potato tubers.

Specificity of DnaK-peptide binding

The sequence specificity of DnaK substrate binding has been studied using a peptide display library. Based on the amino acid patterns that appeared in this selection, short peptides were synthesized for direct measurements of DnaK affinity. The results show that peptides enriched in internal hydrophobic residues are preferential DnaK substrates, and negatively charged peptides have poor affinity. The isolated C-terminal domain of DnaK binds peptides. Peptide dissociation studies indicate that bound peptides are released from the C-terminal fragment and from DnaK at identical rates. ATP stimulates peptide dissociation from DnaK but not from the C-terminal fragment.

In vitro effects of recombinant human interferon gamma on human mesothelioma cell lines

Malignant mesothelioma is a tumor arising from serous surfaces and often related to asbestos exposure. Malignant mesothelioma is resistant to various forms of therapy. Radiotherapy, surgery or chemotherapy only slightly improve prognosis. IFN-gamma produces complete or partial responses in stage-I patients with malignant mesothelioma. The in vitro biological effect of IFN-gamma on malignant mesothelioma cells remains poorly elucidated. In the present study, 32 well-characterized human mesothelioma cell lines (HMCL) were treated with r-hu IFN-gamma at 4 doses and cell growth was determined by a colorimetric method (MTT assay). Among the 32 HMCLs tested, II exhibited significant cell-growth inhibition; 16 were insensitive to r-hu IFN-gamma, and 5 were slightly inhibited. The sensitive cell lines were strongly inhibited by r-hu IFN-gamma. Our results show that HMCL exhibit a large range of responses to r-hu IFN-gamma, some of which can be compared with those obtained in vivo in humans.