[Report of 18 cases lymphoblastic lymphoma]

OBJECTIVE

To identify the clinical, pathological, and immunological characteristics of lymphoblastic lymphoma (LBL).

METHODS

The relation of clinical features, cellular morphology and immuno-phenotypes to the treatment outcome and prognosis was analyzed in 18 LBL patients.

RESULTS

The patients were 15 males and 3 females with a median age of 27 years. Fourteen cases showed bone marrow infiltration, 10 lymphoma leukemia and 9 mediastinal tumor. Fifteen cases were of convoluted cell type expressed T cell marker, three patients were of B-cell type and all achieved complete remission. The 5 year survival rate of the 18 cases was 11.2% with a median survival duration of 10.1 months.

CONCLUSION

LBL was found predominantly in male with a younger onset age, and was characterized by involvement of bone marrow and mediastina. The majority of LBL patients were of convoluted cell type expressed T cell marker. The patients showed poor response to therapy, while B-cell type showed a better prognosis than T-cell type.

A relationship between 5-lipoxygenase-activating protein and bcl-xL expression in murine pro-B lymphocytic FL5.12 cells

Inhibitors of 5-lipoxygenase-activating protein (FLAP) have been found to induce apoptosis. The current study examined the expression of FLAP and bcl family proteins and the induction of apoptosis in interleukin-3-dependent control and bcl-xL-overexpressing FL5.12 cell lines after treatment with MK886, a specific FLAP inhibitor. FL5.12 cells contained a substantial amount of FLAP protein and mRNA but surprisingly had no measurable 5-lipoxygenase protein or 5-, 12-, or 15-lipoxygenase activity. The basal level of FLAP protein in cells overexpressing bcl-xL was 70% less than in controls. FLAP disappeared 4 h after withdrawal of interleukin-3 in bcl-xL cells but not in control cells, which underwent apoptosis. A dose- and time-response study revealed that 5 nmol of MK886/10(6) cells was sufficient to induce apoptosis both in control and bcl-xL cells, respectively, but to different degrees. bcl-xL and bcl-2 proteins, but not bax or FLAP, were decreased by 4 h after 5 nmol of MK886/10(6) cells in both cell lines, although the higher levels of bcl-xL in overexpressors took longer to disappear. This early loss of bcl-xL and bcl-2 was not attributable to generalized proteolysis, as shown by Coomassie Blue staining and by the maintenance of bax. Caspase-3 was activated 2 h after MK886 treatment in control cells but not in bcl-xL cells. Inhibition of caspase-3 decreased MK886-induced apoptosis by 50% in control cells. Inhibition of this caspase after MK886 treatment was unable to prevent the loss of bcl-xL in control cells but did provide partial protection for the loss of the transfected form, but not the endogenous form, in overexpressing cells. These data indicate that MK886 induces extensive apoptosis that is partially caspase-3 dependent and may be related to a rapid loss of bcl-xL. Although caspase-3 inhibitors had no effect on the loss of bcl-xL, other caspases or protease systems may still be involved. The absence of 5-lipoxygenase in cells containing FLAP, the lower level of FLAP in bcl-xL cells, the apoptosis-inducing activity of MK886, and the rapid loss of bcl-xL and bcl-2 proteins after treatment with MK886 strongly indicate that FLAP has activities unrelated to lipoxygenase and suggest a possible functional or regulatory link between these proteins, which share similar subcellular localizations.

An essential role for autophosphorylation in the dissociation of activated protein kinase C from the plasma membrane

The cellular localization of protein kinase C (PKC) is intimately associated with the regulation of its biological activity. Previously we have demonstrated that the redistribution of PKC to the plasma membrane in response to physiological stimuli is followed by a rapid returning of PKC back to the cytoplasm (Feng, X., Zhang, J., Barak, L. S., Meyer, T., Caron, M. G., and Hannun, Y. A. (1998) J. Biol. Chem. 273, 10755-10762). Although the process of PKC membrane targeting has been extensively studied, the molecular mechanism underlying the dissociation of membrane-bound PKC remains unclear. In the present study, by examining the dynamic distribution of wild-type PKC betaII and its kinase-deficient mutant (K371R), we demonstrate that kinase activity is required for PKC membrane dissociation. Moreover, the inability of PKC betaII(K371R) to dissociate from the plasma membrane in cells overexpressing wild-type PKC betaII suggests that autophosphorylation activity of the kinase might be essential for its membrane dissociation. This was further supported by mutational analysis of two in vivo autophosphorylation sites on PKC betaII. The replacement of Ser660 or Thr641 by alanine (S660A or T641A) was found to synergistically reduce the reversal of PKC betaII membrane translocation, whereas the replacement of the same amino acids by glutamic acid (S660E or T641E), an amino acid commonly used to mimic phosphate, results in mutants behaving similar to wild-type PKC betaII. These findings point to an essential role for autophosphorylation in the dissociation of activated PKC from the plasma membrane and suggest that, like PKC membrane translocation, the returning of PKC to the cytoplasm after its activation is also delicately regulated.

[Effect of excitatoxicity on Ca2+/CaM PK II activity in rat hippocampal slices]

The relation between Ca2+/CaM PK II activity and excitatoxicity was studied in an in vitro model of rat hippocampal slices. The slices were exposed to 50-200 mumol.L-1 glutamate or 25-100 mumol.L-1 NMDA and glucose-free Krebs buffer for 30 min after being recovered to normal conditions by 2 hours of incubation with standard Krebs buffer. The results showed that inhibition of Ca2+/CaM PK II activity in rat hippocampal slices was induced by exogenous EAA (glutamate or NMDA), and Ca2+/CaM PK II activity values decreased to 50.1% and 44.7% of control at 200 mumol.L-1 glutamate and 100 mumol.L-1 NMDA, respectively; MK801, but not DNQX, antagonized EAA-induced inhibition of Ca2+/CaM PK II activity. When the slices were pretreated with MK801 prior to exposure to 200 mumol.L-1 glutamate or 100 mumol.L-1 NMDA, the Ca2+/Cam PK II activity values were 91.5% and 96.7%, respectively. The changes of extracellular Ca2+ or Mg2+ concentration influenced Ca2+/CaM PK II activity of the slices exposed to exogenous glutamate; Ca2+/CaM PK II activity values in the presence of extracellular Ca2+ was lower than that in the absence of extracellular Ca2+, and it changed from 50.1% of control (presence of Ca2+) to 64% of control (absence of Ca2+) at 200 mumol.L-1 glutamate, but Ca2+/CaM PK II activity values in the presence of extracellular Mg2+ was higher than that in the absence of extracellular Mg2+, and it changed from 50.1% of control(presence of Mg2+) to 36.6% of control (absence of Mg2+) at 200 mumol.L-1 glutamate. The results suggest that NMDA receptor may be involved in excitotoxicity-induced inhibition of Ca2+/CaM PK II activity.

Apoptosis detection by annexin V binding: a novel method for the quantitation of cell-mediated cytotoxicity

Current standard methods for the measurement of cell-mediated cytotoxicity rely on radioactive tracers, which either detect the release of cytoplasmic contents after plasma membrane disintegration by dying cells (51Cr release), or retained DNA by living cells (the JAM test). In this study, the annexin V binding assay of early apoptosis was applied to measure cell-mediated cytotoxicity. Primed human lymphocytes were examined for their ability to lyse either xenogeneic pig endothelial or allogeneic human PBMC target cells by assaying annexin V binding and the results compared with those obtained by the JAM test. Assaying annexin V binding by indirect immunofluorescence was demonstrated to be more sensitive and faster than the JAM test, which is a well-described, sensitive and simple assay for DNA fragmentation and cell death. However, the annexin V binding method was considered a more accurate measurement of absolute cytotoxicity as individual cell lysis was detected directly. In other methods, cytotoxic activity was calculated indirectly as a percentage of retained or released radioactive label. In addition, the apoptosis induced by the cell-mediated cytotoxicity can be visualized by this method thereby allowing a more accurate and sensitive quantitation of the number of apoptotic cells present when low effector to target ratios are used. These advantages make the annexin V binding method superior to other conventional cytotoxicity assays, particularly in situations where effector cells can be easily distinguished or separated from target cells.

[Demethyltenuicausine, a new bisindole alkaloid from Melodinus hemsleyanus]

Demethyltenuicausine (I), a new bisindole alkaloid, was isolated from Melodinus hemsleyanus and its structure was determined by spectral analysis and semisynthesis. This compound showed antitumor activities in pharmacologicat tests.

The observation of the local ordering characteristics of spermidine-condensed DNA: atomic force microscopy and polarizing microscopy studies

Condensation of DNA by multivalent cations can provide useful insights into the physical factors governing the folding and packaging of DNA in vivo. In this work, local ordered structures of spermidine-DNA complexes prepared from different DNA concentrations have been examined by using atomic force microscopy (AFM) and polarizing microscopy (PM). Two types (I and II) of DNA condensates, significantly different in sizes, were observed. It was found that for extremely dilute solutions (DNA concentrations around 1 ng/microl or below), the DNA molecules would collapse into toroidal structures with a volume equivalent to a single lambda-DNA (type I). In relatively dilute solutions (DNA concentrations between 1 and 10 ng/microll), a significantly larger structure of multimolecular toroids (circular and elliptical, type II) were formed, which were constructed by many fine particles. Measurements show that the average diameter of these fine particles was similar to the outer diameter of the monomolecular toroids observed in extremely dilute solutions, and the thickness of the multimolecular toroids had a distribution of multi-layers with height increments of 11 nm, indicating that the multimolecular toroidal structures have lamellar characteristics. Moreover, by enriching the DNA-spermidine complexes in very diluted solution, branch-like structures constructed by subunits were observed by using AFM. The analysis of the pellets in polarizing microscopy reveals a liquid-crystal-like pattern. These observations suggest that DNA-spermidine condensation could have multiple stages, which are very sensitive to the DNA and spermidine concentrations.

[Biodegradation and biocompatibility of a chitosan film]

The biodegradability and biocompatibility of a chitosan film were investigated in mice. The results showed that chitosan films had a mild inflammatory reaction in the early days of grafting, and after 16 weeks the inflammation basically subsided. Chitosan films were easily biodegraded. Chitosan is a novel natural absorbable medical film material and has a good developmental prospect.

[Precollagen III in the vitreous of eyes with proliferative vitreoretinopathy]

PURPOSE

To detect precollagen III (PC III) levels in serum and vitreous samples from patients with proliferative vitreoretinopathy (PVR).

METHODS

PC III levels were measured by radioimmunoassay in 5 cadaveric vitreous samples from normal subjects, 20 normal human serum samples, 29 vitreous and serum samples from patients with rhegmatogenous retinal detachment complicated with PVR. The relationship between PC III levels and PVR history, surgery, epiretinal membrane, severity of PVR were analyzed with Logistic regression analysis.

RESULTS

The mean PC III levels in serum samples of PVR patients and control subjects were 83.76 +/- 18.52 and 85.02 +/- 17.50 micrograms/L respectively (P > 0.05). PC III was not detected (< 40 micrograms/L) in the cadaveric vitreous. In vitreous aspirates from 29 eyes with PVR, it was not detected in 12 eyes, but higher than 40 micrograms/L in 17 eyes with the mean level of 268.69 +/- 176.07 micrograms/L. (P < 0.05) The high levels correlated with duration and severity of PVR. As onset time and PVR grade increasing, the probability of PC III concentration higher than 40 micrograms/L was 5.2655 and 2.7978 times the concentration lower than 40 micrograms/L respectively.

CONCLUSION

PC III can be detected in vitreous aspirates from PVR eyes. The PC III levels in the vitreous was an event of local responses and were correlated with severity and history of PVR. This suggests that PC III and collagen III be involved in the development of PVR.

[The distribution of nitric oxide synthetase in Vcx and its relation with the expression of FOS induced by teeth movement in rats]

It was studied the central role of nitric oxide(NO) during experimental teeth movement and the relation between nitric oxide synthetase (NOS) positive neurons and FOS like immunoreactivity (FLN) with the NADPH-diaphorase histochemistry and immunocytochemical reaction method. Results indicated that NOS positive neurons and FLN showed typical distribution in Vcx and there was some overlap between them. It suggests that NO is involved in the central modulation of the stimulating message of teeth movement, and which further explains the central modulation mechanism of experimental teeth movement in rats.

Visualization of dynamic trafficking of a protein kinase C betaII/green fluorescent protein conjugate reveals differences in G protein-coupled receptor activation and desensitization

Protein kinase C (PKC) links various extracellular signals to intracellular responses and is activated by diverse intracellular factors including diacylglycerol, Ca2+, and arachidonic acid. In this study, using a fully functional green fluorescent protein conjugated PKCbetaII (GFP-PKCbetaII), we demonstrate a novel approach to study the dynamic redistribution of PKC in live cells in response to G protein-coupled receptor activation. Agonist-induced PKC translocation was rapid, transient, and selectively mediated by the activation of Gqalpha- but not Gsalpha- or Gialpha-coupled receptors. Interestingly, although the stimuli were continuously present, only one brief peak of PKC membrane translocation was observed, consistent with rapid desensitization of the signaling pathway. Moreover, when GFP-PKCbetaII was used to examine cross-talk between two Gqalpha-coupled receptors, angiotensin II type 1A receptor (AT1AR) and endothelin A receptor (ETAR), activation of ETARs resulted in a subsequent loss of AT1AR responsiveness, whereas stimulation of AT1ARs did not cause desensitization of the ETAR signaling. The development of GFP-PKCbetaII has allowed not only the real time visualization of the dynamic PKC trafficking in live cells in response to physiological stimuli but has also provided a direct and sensitive means in the assessment of activation and desensitization of receptors implicated in the phospholipase C signaling pathway.

Identification of a two EF-hand Ca2+ binding domain in lobster skeletal muscle ryanodine receptor/Ca2+ release channel

The lobster skeletal muscle Ca2+ release channel, known also as the ryanodine receptor, is composed of four polypeptides of approximately 5000 amino acids each, like its mammalian counterparts. Clones encoding the carboxy-terminal region of the lobster ryanodine receptor were isolated from a lobster skeletal muscle cDNA library. Analysis of the deduced 1513 carboxy-terminal amino acid sequence suggests a cytoplasmic Ca2+ binding domain consisting of two EF-hand Ca2+ binding motifs (amino acid residues 594-656). The Ca2+ binding properties of this domain were assessed by preparing bacterial fusion proteins with sequences from the lobster Ca2+ binding domain and the corresponding sequences of the rabbit cardiac and skeletal muscle ryanodine receptors. The lobster skeletal muscle fusion protein bound 45Ca2+ in Ca2+ overlays, and bound two Ca2+ under equilibrium binding conditions with a Hill dissociation constant (KH) of 0.9 mM and coefficient (nH) of 1.4. Rabbit skeletal and cardiac fusion proteins bound two Ca2+ with KHs of 3.7 and 3.8 mM and nHs of 1.1 and 1.3, respectively. Similar to results previously reported for the mammalian RyRs, the lobster RyR was activated by micromolar Ca2+ and inhibited by millimolar Ca2+, as determined in single-channel and [3H]ryanodine binding measurements. These results suggest that the two EF-hand Ca2+ binding domain of the lobster Ca2+ release channel as well as the corresponding regions of the mammalian channels may play a role in Ca2+ inactivation of sarcoplasmic reticulum Ca2+ release.

New anti-Cu-TETA and anti-Y-DOTA monoclonal antibodies for potential use in the pre-targeted delivery of radiopharmaceuticals to tumor

Monoclonal antibodies were raised against yttrium(III)-1, 4, 7, 10-tetraazacyclododecane-N,N',N''N'''--tetraacetic acid (Y-DOTA) and copper(II)-1, 4, 8, 11-tetraazacyclotetradecane-N,N',N'',N'''-tetraacetic acid (Cu-TETA). Four hybridomas with high Y-DOTA binding activity and one hybridoma with Cu-TETA activity were selected. MAbs were purified from mouse ascites by Protein A affinity chromatography and characterized. Affinity constants were determined by equilibrium dialysis and the highest affinity Y-DOTA MAb (K(aff) = 1.9 x 10(8) M(-1)) was further characterized by competitive ELISA. Gd-DOTA competed as well as Y-DOTA, whereas In-DOTA required 740x higher concentrations for 50% inhibition of this Y-DOTA MAb binding to human serum albumin-Y-DOTA-coated microtiter plates. These anti-metal chelate MAbs have potential use as vehicles for the pretargeted delivery of radiometal chelates to tumors.

Post-transcriptional suppression of cytosolic ascorbate peroxidase expression during pathogen-induced programmed cell death in tobacco

As a means to eliminate pathogen-infected cells and prevent diseases, programmed cell death (PCD) appears to be a defense strategy employed by most multicellular organisms. Recent studies have indicated that reactive oxygen species, such as O2.- and H2O2, play a central role in the activation and propagation of pathogen-induced PCD in plants. However, plants contain several mechanisms that detoxify O2.- and H2O2 and may inhibit PCD. We found that during viral-induced PCD in tobacco, the expression of cytosolic ascorbate peroxidase (cAPX), a key H2O2 detoxifying enzyme, is post-transcriptionally suppressed. Thus, although the steady state level of transcripts encoding cAPX was induced during PCD, as expected under conditions of elevated H2O2, the level of the cAPX protein declined. In vivo protein labeling, followed by immunoprecipitation, indicated that the synthesis of the cAPX protein was inhibited. Although transcripts encoding cAPX were found to associate with polysomes during PCD, no cAPX protein was detected after in vitro polysome run-off assays. Our findings suggest that viral-induced PCD in tobacco is accompanied by the suppression of cAPX expression, possibly at the level of translation elongation. This suppression is likely to contribute to a reduction in the capability of cells to scavenge H2O2, which in turn enables the accumulation of H2O2 and the acceleration of PCD.

[Identification of powdered Bungarus multieinctus Blyth and its adulterants]

This paper reports the results of identification of powdered Bungarus muliteinctus and its adulterants (Natrix annularis; Dinodon rufozonatum and Bungarus fascitus). A comparative table of and a key to the characteristics are given.

Observation on electromyogram changes in 93 cases of peripheral facial paralysis treated by point-through-point acupuncture

Bioelectricity of the affected muscles at acute stage, recovery stage and sequel state in 93 cases of peripheral facial paralysis was observed with EMG. Pathological potential or motor potential was found to be reduced to varying degrees in all the affected muscles. After treatment by point-through-point acupuncture, myodynamia recovered fairly rapidly, EMG showed obvious changes, pathological potential decreased, and the normal motor unit potential increased remarkably. Comparative analysis of EMG before and after acupuncture indicated that point-through-point acupuncture had an obvious therapeutic effect on the disease. It was also very significant that EMG was used in diagnosing various stages of peripheral facial paralysis, evaluation of prognosis and guidance in clinical treatment.

High- and low-abundance chemoreceptors in Escherichia coli: differential activities associated with closely related cytoplasmic domains

In Escherichia coli, two high-abundance chemoreceptors are present in cellular dosages approximately ten-fold greater than two low-abundance receptors. In the absence of high-abundance receptors, cells exhibit an abnormally low tumble frequency and the ability of the remaining receptors to mediate directed migration in spatial gradients is substantially compromised. We found that increasing the cellular amount of the low-abundance receptor Trg over a range of dosages did not alleviate these defects and thus concluded that high- and low-abundance receptors are distinguished not simply by their different dosages in a wild-type cell but also by an inherent difference in activity. By creating hybrids of the low-abundance receptor Trg and the high-abundance receptor Tsr, we investigated the possibility that this inherent difference could be localized to a specific receptor domain and found that the cytoplasmic domain of the high-abundance receptor Tsr conferred the essential features of that receptor class on the low-abundance receptor Trg, even though it is in this domain that residue identity between the two receptors is substantially conserved.

Carbofuran degradation in soil profiles

Two soils, Puyallup fine sandy loam from Puyallup, WA, and Ellzey fine sand from Hastings, FL, each with a prior history of carbofuran exposure but with different pedological and climatological characteristics, were found to exhibit enhanced degradation toward carbofuran in surface and subsurface soil layers. The treated Puyallup and Ellzey soils exhibited higher mineralization rates for both the carbonyl and the aromatic ring of carbofuran when compared to untreated soils. Disappearance rates of [14C-URL (uniformly ring labeled)] carbofuran in the treated Ellzey soil was faster than in untreated soil, and also faster in surface soil than in subsurface soil. Initial degradation patterns in the treated Ellzey soil were also different from those in the untreated soil. The treated Ellzey soil degraded carbofuran mainly through biological hydrolysis, while untreated soil degraded carbofuran through both oxidative and hydrolytic processes.

The conformation of an inhibitor bound to the gastric proton pump

Substituted imidazo[1,2-a]pyridines are pharmaceutically important small molecule inhibitors of the gastric H+/K+-ATPase, the membrane-bound therapeutic target for peptic ulcer disease. A non-perturbing analytical technique, rotational resonance NMR spectroscopy, was used to measure a precise (to +/-0.2 A) distance between atomic sites in a substituted imidazo[1,2-a]pyridine, TMPIP, bound to H+/K+-ATPase at its high-affinity site in the intact, native membrane. The structural analysis of the enzyme-inhibitor complex revealed that the flexible moiety of TMPIP adopts a 'syn-type' conformation at its site of action. Hence, the conformation of an inhibitor has been resolved directly under near-physiological conditions, providing a sound experimental basis for rational design of many active compounds of pharmaceutical interest. Chemically restraining the flexible moiety of compounds like TMPIP in the syn-type binding conformation was found to increase activity by over 2 orders of magnitude. Such information is normally only available after extensive synthesis of related compounds and multiple screening approaches.