B cell differentiation factor-induced B cell maturation: regulation via reduction in cAMP

We have previously described a novel human B cell differentiation factor (BCDF), 446-BCDF, that is distinct biochemically and functionally from other cytokines. Since signal transduction pathways involved in human B cell differentiation have been incompletely studied and are poorly understood, we assessed the effects of 446-BCDF on various intracellular second messenger systems. After exposure of B cells to 446-BCDF, intracellular cAMP concentration started to decrease at 5 min and was significantly lower at 30 min and reached the lowest level at 4 hr. In most cases, cAMP concentrations returned toward baseline by 24 hr. A cAMP analog (dibutyryl cAMP), a stimulator of adenyl cyclase (forskolin), and phosphodiesterase inhibitors (aminophylline and IBMX) which inhibited the 446-BCDF-induced decrease in intracellular cAMP, inhibited 446-BCDF-induced B cell differentiation, suggesting that the fall in intracellular cAMP was a critical event in this process. To understand the mechanism involved in the reduction of cAMP, B cells were treated with pertussis toxin (PTX), a Gi protein inhibitor. Pertussis toxin blocked 446-BCDF-induced B cell differentiation as well, suggesting that 446-BCDF may function by stimulation of a Gi-linked receptor resulting in the inhibition of adenylate cyclase with a consequent reduction in cAMP. Other cytokines known to promote Ig secretion (IL2 and IL6) also caused a reduction in cAMP, suggesting that this pathway may be generally important in B cell differentiation. Taken together, these data suggest that at least one pathway of terminal maturation in B cells may involve the reduction of intracellular cAMP.

Angiogenic potential of the avian somite

We have studied the angiogenic potential of the unsegmented paraxial mesoderm and epithelial somites of the trunk with homotopical grafts between quail and chick embryos. Quail endothelial cells of the grafts were stained with the QH-1 antibody after 1-6 days of reincubation. The unsegmented paraxial mesoderm and all parts of the epithelial somite were found to contain angioblasts which develop into QH-1 positive endothelial cells. These cells are incorporated into the lining of the host's blood vessels such as the perineural vascular plexus and the dorsal branches of the aorta. There is a certain preference as concerns the location of endothelial cells derived from different parts of the somites. Angioblasts from ventral somite halves are mainly found in ventrolateral blood vessels. Those from dorsomedial quadrants form vessels in the dermis of the back, and those from dorsolateral quadrants can be found in the ventrolateral body wall and the wing. With the exception of the dorsal perineural vascular plexus, angioblasts do not cross the median plane of the body. This shows that, although angioblasts migrate extensively, there is bilaterality of the vascular system in the trunk. It remains to be studied whether the notochord plays a role in the establishment of this bilaterality.

Morphology and morphogenesis of hepatitis E virus (strain 87A)

The morphology and morphogenesis of isolated hepatitis E virus (HEV, strain 87A) were observed by electron microscopy (EM) and immune electron microscopy (IEM). Progressively developing local vesicles, virions accumulation in crystalline arrays and viroplasmic focus were seen in cytoplasm of infected cells. Replication and assembly of the new generation viruses were closely associated with rough endoplasmic reticulum (RER), inclusion body (IB) and microfibrils. Condensation and margination of chromatin, dispersion of nucleolar material, nuclear membrane alteration and masses of threads, granular material, and fibrillar component of the nucleus were frequently found. These changes revealed that this strain virus was confirmed as a RNA virus. The shape of the virus particles appeared approximately spherical whether the specimens were from the tissue culture crude suspension or purified highly concentrated preparations. The size of the virion was about 30 nm in diameter. The viral particles appeared unsmooth and irregular in outline. The spike-like structures may be occasionally observed on the surface of some viral capsides. The diameter of the strain 87 A virus is larger than the picornavirus and smaller than the calicivirus. This strain virus is different from classical calicivirus in without the cup-shaped surface depressions. The new genus, heparnavirus genus of caliciviridae family should be proposed for HEV.

Neuroprotective effect of phenylsuccinate, an inhibitor of cytosolic glutamate formation from glutamine, under anoxic conditions but not during exposure to exogenous glutamate

Phenylsuccinate is an inhibitor of cytosolic glutamate formation from extracellular glutamine in cultured cerebellar granule cell neurons, a glutamatergic preparation. It prevents anoxic cell death in these cells as indicated by decreased lactate dehydrogenase (LDH) release and by the morphological appearance of the cells after the insult. In contrast, it does not prevent neurotoxicity by added glutamate because it is not an antagonist of the glutamate receptor.

Genetic competence in Escherichia coli requires poly-beta-hydroxybutyrate/calcium polyphosphate membrane complexes and certain divalent cations

In earlier studies of genetic competence in Escherichia coli induced with calcium-containing buffers, a strong correlation was found between transformation efficiency and the formation of poly-beta-hydroxybutyrate/calcium polyphosphate (PHB/Ca2+/PPi) complexes in the plasma membranes. In this study, we replaced Ca2+ with one of a number of other cations--monovalent, divalent, and trivalent--and found significant numbers of transformants (transformation efficiency, > 10(5)/micrograms of pBR322 DNA) only when the cells had high levels of PHB/Ca2+/PPi and the medium contained at least one of the divalent cations Ca2+, Mn2+, Sr2+, or Mg2+. Cells with high levels of the complexes were not competent when the medium did not contain these cations, but the cations were also ineffectual when the cells had few complexes. Surprisingly, Mn, Sr, and Mg were not incorporated into the complexes in place of Ca. These results indicate that PHB/Ca2+/PPi complexes and the above-mentioned divalent cations each have essential but disparate roles in genetic competence. Moreover, the strong selectivity of PHB/PPi for Ca2+ suggests the binding sites in the complexes are ionophoretic.

Infrequent co-localization of nitric oxide synthase and calcium binding proteins immunoreactivity in rat neocortical neurons

Immunoreactivity to nitric oxide synthase (NOS-IR) was detected in a small population of rat neocortical neurons scattered throughout the frontal, parietal, temporal and occipital cortices. Two-color double-labeling studies revealed that the number of NOS-IR neocortical neurons expressing immunoreactivity to the calcium binding proteins parvalbumin (PV-IR), calbindin-D28K (CB-IR) or calretinin (CR-IR), was low. The absence or low level of calcium binding proteins may imply a reduced Ca2+ buffering capacity in NOS-containing neurons, thereby contributing to their vulnerability to Ca2+ influx through the activated AMPA/kainate receptors reported by others.

Effect of anoxia on glutamate formation from glutamine in cultured neurons: dependence on neuronal subtype

Synthesis and release of glutamate formed from labeled glutamine were studied in primary cultures of the glutamatergic cerebellar granule cells and of the mainly GABAergic cerebral cortical neurons under anoxic conditions and under normoxic control conditions. Under both control and anoxic conditions cerebellar granule cells synthesized and released glutamate more intensely than cerebral cortical neurons, but this difference was enhanced under anoxic conditions. Thus, under normoxic conditions synthesis of intracellular labeled glutamate from glutamine was twice as high in cerebellar granule cell neurons as in cerebral cortical neurons during 30 min of incubation, but the release of newly synthesized labeled glutamate to the extracellular medium from cerebellar granule cell neurons was more than 4 times higher than the release from cerebral cortical neurons during 30 min of incubation. Based on these observations it is suggested that a major reason for the increase in extracellular glutamate concentration during brain ischemia may be enhanced production and release of glutamate, especially in glutamatergic neurons.

[Quantitative analysis of cellular morphometry and DNA content measurement of experimental lung adenocarcinoma]

This article reported the image analysis of normal epithelia of bronchi (group 1), hyperplasia epithelia (group 2), atypical hyperplasia epithelia (group 3) and adenocarcinoma (group 4) of the lung in the hamsters induced by tin mine dust and chimney dust in Yunnan Tin Min CO. 16 parameters were observed and compared. Each value was tested by stepwise discriminational classification and an accuracy rate of 95% was reached. DNA ploidy was investigated, and no case of > 5C cell was found in normal and hyperplasia group. Severe atypia had a lower percentage, (4.00%) and lung adenocarcinoma was characterized by a high percentage of > 5C cell (10.75%), A significant difference was shown between the percentage of > 5C cell of severe atypia and that of adenocarcinoma. Significantly different (P < 0.01).

Genes for mast-cell serine protease and their molecular evolution

Trypsin-related serine proteases are encoded by a very large gene family in mammals. We describe here a comparative analysis of the genomic DNA sequences of mouse, rat, and human mast-cell-specific serine protease genes. Strong evidence was found for multiple exchanges of genetic information between closely related members of this gene family. The 5' regulatory regions of MMCP-1 and MMCP-L share a remarkably high degree of sequence identity (98%), starting 10 base pairs downstream of exon 1 and extending to the end of the presently sequenced region at position -1347 of the MMCP-1 gene. The remaining parts of the two genes share approximately 80% sequence identity. Evidence for at least two additional, but not so recent, exchanges was found in the 3' regions of the MMCP-4 and MMCP-L genes and in the 5' regions of the genes for MMCP-1 and MMCP-2. The 5' regulatory regions of all presently characterized mouse mast-cell-specific chymotrypsin-like serine protease genes exhibit over 88% sequence identity in the region from the transcription initiation site to approximately position -600. An exception is MMCP-5 which is the most distantly related member of this subfamily. The high degree of sequence similarities indicates a strong evolutionary homogenization of the 5' regulatory region, possibly by several gene conversion events. In addition, several insertions of genetic information have been identified in genes for mast-cell chymases and genes for T-cell granzymes. A number of these have been found to represent repetitive sequences, such as L1. The previously characterized tissue-specific enhancer element of the RMCP II gene was identified as a member of a middle repetitive sequence. A cDNA for a newly discovered pseudogene, closely related to the mouse mast cell chymases was isolated by polymerase chain reaction amplification from a mouse connective tissue-like mast cell line. The structure of this cDNA is presented. We also present the characterization of a novel spliced variant of MMCP-6 that contains an alternative 3' terminal exon (exon 6). The function of this variant, if any, is still unknown. A comparative analysis of amino acid sequence identities between different hematopoietic serine proteases shows that a high degree of sequence similarity does not always correlate with relateness in cleavage specificity. This indicates that the substrate specificity evolved with a higher evolutionary rate than the degree of overall amino acid sequence identity of these proteases.

The fate of somitocoele cells in avian embryos

The early somite of avian embryos is made up of an epithelial wall and mesenchymal cells located within the somitocoele. We have studied the fate of somitocoele cells for a period of up to 6 days, using the quail-chick marker technique. We also applied the QH-1 antibody, which specifically stains hemangiopoietic cells of quail origin, and studied the proliferative activity of epithelial somites with the BrdU anti-BrdU method. Our results show that somitocoele cells mainly give rise to the ribs and peripheral parts of the intervertebral discs. After 1 and 2 days of reincubation, the grafted somitocoele cells were located in the lateral part of the sclerotome, and only a few cells migrated axially towards the notochord. In frontal sections, the cells were located in a triangular area within the cranial part of the caudal sclerotome half. After 3 days of reincubation, some of the cells had migrated cranially along the myotome. After longer reincubation periods, cells grafted into one somite could be found in two adjacent ribs. The studies with the QH-1 antibody show that a subpopulation of somitocoele cells has angiogenic potency. Endothelial cells originating from the mesenchyme of the somitocoele migrated actively and even invaded the ipsilateral half of the neural tube. In the epithelial wall of the somite, BrdU-labelled nuclei were found basally, whereas more apically the nuclei were not stained, but mitotic figures were frequently present. The somitocoele cells also showed a high proliferative activity with about 26% of nuclei labelled with BrdU.

Human cell lines U-937, THP-1 and Mono Mac 6 represent relatively immature cells of the monocyte-macrophage cell lineage

Three human monocytic cell lines, U-937, THP-1 and Mono Mac 6 have, because of their morphology and staining properties, been classed as cell lines frozen in a window of the monocyte differentiation lineage corresponding to monoblasts and/or immature monocytes. These cell lines were analyzed for expression of a panel of hematopoietic differentiation markers by Northern blot analysis. They were all found to express one or several biochemical markers characteristic of immature cells in monocytic development, including myeloperoxidase, N-elastase, cathepsin G, myeloblastin, and azurocidin. Normal peripheral blood monocytes did not express these markers. Moreover, several markers expressed at high levels in mature monocytes, such as lysozyme, CD14, MHC class II and alpha-1 antitrypsin were either not expressed or were expressed only at low levels in the three cell lines analyzed. These results show that arrested differentiation at a relatively early stage of monoblast development is a common denominator for these human monocytic cell lines. Thus, transforming mutations acting at such an immature differentiation stage may frequently lead to neoplastic transformation, whereas similar mutations occurring at a more mature differentiation stage never give rise to any leukemias due to the loss of proliferative potential in committed cells.

Expression of the murine plasma cell nucleotide pyrophosphohydrolase PC-1 is shared by human liver, bone, and cartilage cells. Regulation of PC-1 expression in osteosarcoma cells by transforming growth factor-beta

A bone and cartilage enzyme with both 5'-nucleotide phosphodiesterase I and nucleotide pyrophosphohydrolase (NTPPPH) activity modulates physiologic mineralization and pathologic chondrocalcinosis by generating inorganic pyrophosphate. We hypothesized that, as for alkaline phosphatase, expression of an NTPPPH gene can be shared by cells from bone, cartilage, and liver and by certain leukocytes. Recently, we demonstrated the hepatocyte and murine plasma cell membrane glycoprotein PC-1 to have both 5'-nucleotide phosphodiesterase I and NTPPPH activity. We detected polypeptides cross-reactive with PC-1 in human U20S osteosarcoma cells, articular chondrocytes, homogenized human knee cartilages, human knee synovial fluids, hepatoma cells, and murine plasmacytoma cells. Constitutive low abundance PC-1 mRNA expression was detected in U20S cells and chondrocytes by a nested RNA-PCR assay and by Northern blotting. TGF beta is known to substantially increase NTPPPH activity in primary osteoblast cultures. We demonstrated that TGF beta 1 increased NTPPPH activity and the level of PC-1 mRNA and immunoprecipitable [35S]-methionine-labeled PC-1 polypeptides in U20S cells. The identification of PC-1 as an NTPPPH expressed in cells derived from bone and cartilage may prove useful in furthering the understanding of the role of NTPPPH i n physiologic and pathologic mineralization.

Phosphatidylinositol 3,4,5-trisphosphate is formed from phosphatidylinositol 4,5-bisphosphate in thrombin-stimulated platelets

Platelets accumulate PtdIns(3,4,5)P3 and PtdIns(3,4)P2 in response to thrombin and thrombin-receptor-directed peptide in a GTP-dependent manner. These phosphoinositides are considered to be mediators of signaling events in a variety of cells. We have examined the metabolic route by which PtdIns(3,4,5)P3 and PtdIns(3,4)P2 are synthesized by briefly (10 min) incubating platelets with high activities of [32P]Pi, followed by 20 or 60 s exposure to thrombin, and analysing the relative radioactivities of the individual phosphate groups in the resulting labelled PtdIns(3,4,5)P3 and PtdIns(3,4)P2. The phosphate group possessing the highest specific activity under such non-equilibrium labelling conditions indicates the last one added in a metabolic sequence. The thrombin-stimulated rate of labelling of PtdIns(3,4)P2 was significantly slower than that of PtdIns(3,4,5)P3. Increased labelled PtdIns3P was not detected within 60 s. The measured relative radioactivities decreased in the order 3 > 5 > 4 >> 1 for PtdIns(3,4,5)P3 and 3 > 4 >> 1 for PtdIns(3,4)P2. On the basis of the results of both rate-of-labelling and specific radioactivity analyses we conclude that PtdIns(3,4,5)Pa is formed by 3-OH phosphorylation of PtdIns(4,5)P2, whereas PtdIns(3,4)P2, may be formed by 3-OH phosphorylation of PtdIns4P and/or dephosphorylation of PtdIns(3,4,5)P3. These findings point to the activation of phosphoinositide 3-kinase as a critical receptor-regulated step in thrombin-stimulated platelets.

Effects of chronic exposure to ammonia on glutamate and glutamine interconversion and compartmentation in homogeneous primary cultures of mouse astrocytes

Accumulation of radioactivity was studied in primary cultures of mouse astrocytes as a function of time of exposure (4-60 min) to 50 microM glutamate and 200 microM glutamine (initial concentrations), of which either glutamate or glutamine was 14C-labeled. Both the glutamate pool and the glutamine pool were compartmentalized. Initially, by far the major intracellular glutamate pool (> or = 90%) was derived from extracellular glutamate and could be converted to glutamine. This allowed a rather accurate determination of metabolic flux from glutamate to glutamine, which under control conditions amounted to 2.0-2.2 nmol/min per mg protein. After chronic exposure to 3 mM ammonia for 3 days this flux was significantly increased to 3.1-3.6 nmol/min per mg protein. Acute exposure to ammonia caused a smaller, apparent increase, which was not statistically significant. The glutamine content was compartmentalized at all stages of the incubation. It consisted of at least two different pools. One of these was accessible to extracellular glutamine and could be converted to intracellular glutamate (constituting a sizeable fraction of the total glutamate pool after longer incubation), whereas the other constituted endogenously derived glutamine, formed from accumulated glutamate. The specific activity of the precursor pool for glutamate synthesis could not be accurately determined and relatively exact fluxes therefore not be calculated. There was, however, no evidence that chronic exposure to ammonia decreases the rate of glutamine hydrolysis.

Clonidine enhances astrocytic glutamine uptake by authentic alpha 2-adrenoceptor stimulation

The alpha 2-adrenergic agonist clonidine stimulates glutamine uptake and metabolism in primary cultures of mouse astrocytes. This is important because glutamine is a metabolic substrate for these cells. The alpha 2-antagonist yohimbine inhibits the clonidine stimulation, although not completely. The residual effect in the presence of yohimbine can be explained by the fact that this drug is also a serotonin agonist. Idazoxan, which specifically inhibits imidazoline preferring receptors, exerts no inhibition of glutamine uptake. These results suggest that the stimulatory effect of clonidine on glutamine accumulation in mouse astrocytes is due to its effect at an authentic alpha 2-adrenergic receptor site, not at the imidazoline preferring receptor site.

Programmed cell-death and its control in the development of adult T-cell leukemia - hypothesis

Despite the progress in virological and molecular studies on human T-cell leukaemia virus (HTLV-1), there still exist enigmas in biological and clinical features of adult T-cell leukaemia/lymphoma (ATL). They include the way of the development of ATL clones, the role of interleukin-2 (IL-2) receptors on the tumour cells and spontaneous fluctuation of the clinical activity frequently observed in chronic type of the disease. To elucidate these enigmas, based on our recent experimental data, we would like to present a model of the development of ATL clones from: the view point of programmed cell death (PCD) and its control.

Accuracy of age reporting in census regarding nationalities with population over one million people in China

"Quality inspection of census results may be conducted in three areas: failure to report...,repetitive reportage...,and erroneous reportage.... This study focuses on error report on age by people of different nationalities in China.... Discussions in this paper are mainly devoted to the accuracy of age reporting...in the fourth census [of 1990]."

Signalling effect of elevated potassium concentrations and monoamines on brain energy metabolism at the cellular level

The effects of elevated K+ concentrations and monoamine transmitters on different cell types in the CNS and on different subcellular structures in these cells are reviewed. Pronounced differences exist in the metabolic processes that are stimulated by excess K+ and by adrenergic agonists, e.g., noradrenaline. An elevation in the extracellular K+ concentration appears to enhance neuronal-astrocytic interaction by stimulating metabolic processes involved in (1) the promotion of supply of precursors for transmitter glutamate, and (2) reestablishment of resting ion distribution following neuronal excitation. The monoamine transmitters stimulate energy production and Na+,K(+)-ATPase activity in astrocytes in a complex manner and, in so doing, facilitate their role in ion regulation. However, in contrast to excess K+, they do not enhance the production of astrocytic precursors for neuronal glutamate production. Emphasis is placed on possible profound differences in metabolic effects on excitatory and inhibitory neurotransmission and on the importance of stimulation of glycolytic metabolism in astrocytes versus oxidative metabolism in neurons.

Expression of a mast cell tryptase in the human monocytic cell lines U-937 and Mono Mac 6

Expression of a mast cell tryptase mRNA was detected in two human monocytic cell lines, the U-937 and the Mono Mac 6, and in normal human peripheral blood (PB) monocytes. In the U-937 cell line but not in normal PB monocytes, the tryptase expression was upregulated 3-50 fold following phorbol ester (PMA)-induced differentiation, but no such induction was seen after retinoic acid, interferon-gamma or vitamin D3 exposure. The tryptases expressed in PMA-induced and non-induced U-937 and in Mono Mac 6 were characterized by PCR amplification and nucleotide sequence analysis. The U-937 cell line was found to express a tryptase identical to one of the previously cloned mast-cell beta tryptases (Tryptase I), and the tryptase expressed in Mono Mac 6 was found to be nearly identical to the previously cloned alpha tryptase. By northern blot analysis with oligonucleotide probes specific for the alpha and beta tryptases both cell lines were found to express only one type of tryptase. Densitometric quantifications of tryptase mRNA levels, in the two cell lines, showed approximately 80 times higher mRNA levels in Mono Mac 6 compared to non-induced U-937. Immunohistochemical staining for tryptase showed a marked heterogeneity in the Mono Mac 6 cell line. Only one out of 10 cells were positive for the protein but the levels in these cells were very high, equivalent, or even higher than the levels seen in the human mast cell line HMC-1. This shows that the expression of a single tryptase, in this case the alpha tryptase, is sufficient for the production of a stable protein and probably also a stable proteolytically active tetramer. The family of human mast-cell tryptases has been considered to represent a class of proteases specifically expressed in mast cells and basophilic leucocytes. The expression of tryptases in two monocytic cell lines and in normal PB monocytes indicate that in humans, the lineage specificity of these serine proteases is less restricted than earlier expected. The cloning of a full length cDNA for the murine counterpart to the human mast cell tryptases, the MMCP-6, is presented. No expression of the MMCP-6 was detected in a panel of mouse monocyte or macrophage cell lines indicating a species difference in the lineage specificity of the 'mast cell tryptases'.

Glutamate uptake and glutamate content in primary cultures of mouse astrocytes during anoxia, substrate deprivation and simulated ischemia under normothermic and hypothermic conditions

During brain ischemia in vivo the extracellular concentration of the excitotoxic amino acid, glutamate, increases. This increase could be caused either by an enhanced formation rate of glutamate (from glutamine) or by an impaired re-uptake (or both). This re-uptake occurs to a large extent in astrocytes. In the present study we have determined glutamate uptake and the ability of the cells to maintain their glutamate content during exposure to anoxia, substrate deprivation and combined substrate deprivation and anoxia ('simulated ischemia') for a duration of up to 4 h. Isolated anoxia had no significant effect, whereas both substrate deprivation alone and 'simulated ischemia' reduced glutamate uptake and glutamate content by one-half after 2 h. Under hypothermic conditions (incubation at 32 degrees C), which in in vivo experiments exerts some protection against ischemic cell death in neurons, ischemia of intermediate duration (2 h) decreased glutamate uptake and glutamate content to a less extent than at 37 degrees C. Hypothermia did not have a similar effect during exposure to isolated substrate deprivation.

Utilization of glutamine and of TCA cycle constituents as precursors for transmitter glutamate and GABA

In the present review evidence is presented that (1) glutamine synthesis in astrocytes is essential for synthesis of GABA in neurons; (2) alpha-ketoglutarate in the presence of alanine (as an amino group donor) can replace glutamine as a precursor for synthesis of transmitter glutamate, but maybe not as a precursor for transmitter GABA; (3) differences exist in the intraneuronal metabolic pathways for utilization of alpha-ketoglutarate plus alanine and of glutamine, and (4) alanine also functions as a substrate for oxidative metabolism in glutamatergic neurons. It should be emphasized that the supply of precursors for transmitter glutamate and GABA in glutamatergic and GABAergic neurons depends on metabolic processes in astrocytes regardless whether glutamine or alpha-ketoglutarate plus L-alanine function as the transmitter precursors. The key reason that an interaction with astrocytes is essential is that both pyruvate carboxylase, the major enzyme in the brain for net synthesis of tricarboxylic acid cycle intermediates, and glutamine synthetase, the enzyme forming glutamine from glutamate, are specifically located in astrocytes, but not in neurons.

Glutamate and glutamine metabolism and compartmentation in astrocytes

Metabolism of glutamate and glutamine in cultured mouse cerebral cortical astrocytes has been investigated using either radioactively labelled (14C) amino acids or 13C-labelled amino acids combined with NMR spectroscopy of cell extracts and lyophilyzed incubation media. Using [U-13C]glutamate it has been shown that in astrocytes exogenously supplied glutamate is primarily (70%) metabolized oxidatively through the tricarboxylic acid (TCA) cycle and to a lesser extent (30%) directly to glutamine. Glutamate metabolized in the TCA cycle is to a large extent recovered as lactate showing that the astrocyte-specific enzyme, malic enzyme is functionally active. Incubation with [U-14C]glutamine led to a higher specific radioactivity in glutamate than in glutamine. It could also be shown that glutamate and glutamine were metabolized differently to aspartate and alanine. These results taken together strongly suggest that glutamate/glutamine metabolism in astrocytes is compartmentalized and a model with multiple cytoplasmic and mitochondrial compartments of these amino acids is proposed.

Phenotypic characterization of KU812, a cell line identified as an immature human basophilic leukocyte

The knowledge about the differentiation of basophilic leukocytes is fragmentary. This report discusses a detailed phenotypic characterization of molecular markers for hematopoietic differentiation in a basophilic leukemia cell line, KU812. The expression of markers for lymphoid, erythroid, neutrophil, eosinophil, monocytic, megakaryocytic, mast cell and basophil differentiation was analyzed at the mRNA level by Northern blots in the KU812 cells, and for reference, in a panel of human cell lines representative of the different hematopoietic differentiation lineages. KU812 was found to express a number of mast cell and basophil-related proteins, i.e. mast cell tryptase, mast cell carboxypeptidase A, high-affinity immunoglobulin (IgE) receptor alpha and gamma chains and the core protein for heparin and chondroitin sulphate synthesis. We found no expression of a number of monocyte/-macrophage or neutrophil leukocyte markers except for lysozyme. From earlier studies, it has been shown that lysozyme is not expressed in murine mucosal mast cell lines. This finding, together with the expression of the mast cell carboxypeptidase in KU812 might distinguish the phenotype of this cell line from that typical of mucosal mast cell lines in rodents. We found a low level of expression of the eosinophil and basophil marker, major basic protein, which might indicate a relationship between basophils and eosinophils. No expression is, however, detected with the eosinophil-specific markers eosinophil cationic protein, eosinophil-derived neurotoxin or eosinophil peroxidase. We also report an extensive screening for inducers of basophilic differentiation of the KU812 cells. The most efficient protocol of induction included serum starvation which led to a dramatic increase in a number of markers specific for mast cells and basophils such as tryptase, carboxypeptidase A and the heparin core protein. Finally, diisopropylfluorophosphate analysis of total protein extracts from KU812 show four labeled protein bands with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that this cell line expresses at least three previously undescribed serine proteases of which one or more could be a potential basophil-specific marker(s).

Prospective analysis of mental status progression in ethanol-intoxicated patients

Distinguishing patients with uncomplicated ethanol intoxication from intoxicated patients with other causes of mental status depression is a common clinical dilemma. The authors serially tested mental status in a group of ethanol-intoxicated patients to determine the interval over which mental status changes could be attributed to uncomplicated intoxication. Study patients were identified by (1) admission breath ethanol greater than or equal to 100 mg/dL; (2) ethanol-related impairment necessitating further observation or treatment; and (3) not critically ill or exhibiting focal neurologic signs. Mental status scores (sums of specific indices of alertness, orientation, and agitation) were determined initially, 1 hour after arrival, then every 2 hours. Causes of mental status depression other than acute intoxication were diagnosed in 16 patients, while another 18 failed to completely normalize mental status by the time of emergency department discharge or hospital admission. The remaining 71 with uncomplicated ethanol intoxication required (mean +/- SD) 3.2 +/- 3.6 hours to normalize mental status scores. A large proportion, however, took considerably longer to normalize mental status: 15 (21%) took 7 or more hours, and three (4%) took as long as 11 hours. Although patients with ethanol-associated depression of mental status lasting 3 hours after emergency department admission should be carefully evaluated for other causes of mental status abnormalities, the authors' observations indicate considerable individual variation in the duration of mental status depression caused by uncomplicated ethanol intoxication.

Effect of body locale and addition of epinephrine on the duration of action of a local anesthetic agent

STUDY OBJECTIVE

Little information exists relating body locale to the duration of action of local anesthetics. We tested the duration of action of a local anesthetic with and without epinephrine at different body locales.

PARTICIPANTS

Twenty healthy volunteers aged 27 to 48 years (mean, 32.0 years).

INTERVENTIONS

In the first of two experiments (L), 20 subjects had 1 mL buffered 1% lidocaine injected intradermally on the forehead, hand, forearm, and calf. In the second experiment (LE), ten subjects were injected at the same sites with lidocaine containing epinephrine.

METHODS

Subjects ranked anesthesia by reaction to pinprick from 0 (complete) to 20 (none) on a scale with testing done every 15 (L) or 30 (LE) minutes and continued until no anesthetic effect was present. Duration of effective and of any anesthesia were times until score of more than 5 and of more than 19, respectively. Mean duration of anesthesia was compared by analysis of variance (between body areas) and paired two-tailed t-test (L vs LE). Significance was taken as P less than or equal to .05.

RESULTS

Anesthesia was significantly briefer for the face than for all other body locales by both indexes of duration and for both plain lidocaine and lidocaine with epinephrine (P less than .001 to P less than .05). Anesthesia with epinephrine lasted significantly longer than with lidocaine alone at all body locales and for duration of both effective or any anesthesia (P = .0001 to P = .001). Based on 95% confidence interval limits, the duration of anesthesia at other body locales is predicted to be 1.3- to 3.2-fold that on the face. Confidence interval analysis indicated that addition of epinephrine to lidocaine increases the duration of anesthetic action by 1.3- to 13.0-fold that of lidocaine alone.

CONCLUSION

The duration of action of local anesthesia is considerably shorter for the face than for other body areas. Epinephrine significantly increases the duration of action of lidocaine at all body locales.

[Acid-base imbalance in acute cerebrovascular diseases]

Ninety cases of cerebral hemorrhage or infarction confirmed with CT scans were reported. Blood specimens were taken within 4 to 24 hours after the onset of the strokes for blood gas analysis. The results showed that respiratory alkalosis occurred in all patients with cerebral hemorrhage or embolism, while the metabolic acidosis accompanied only those with severe cerebral infarctions or intracerebral hematomas rupturing into the ventricles small local infarcts caused only hypoxemia or no changes at all. It seemed likely that the blood acid-base changes were closely related to the nature and the size of the lesions. It was suggested that since hyperventilation caused by cerebral lesions might be the main factor that give rise to respiratory alkalosis, it would be of great importance to maintain the acid base balance in the acute stage of the stroke with proper dehydration therapy and oxygen administration.

Anti-PPD antibodies in Chinese Behçet's disease

Anti-PPD antibody determinations were carried out by the ELISA method using extracted PPD of tubercle bacillus H37RV as the target antigen. The positive rates of anti-PPD antibodies in patients with active tuberculosis, inactive tuberculosis, Behçet's disease, or non-tubercular disease and in a village population were 97.5%, 77.4%, 48.9%, 33.6% and 13.9%, respectively. Although the average titer of anti-PPD antibodies in Behçet's disease was lower (2.168 +/- 0.854) than that in active tuberculosis (3.126 +/- 1.182), it was about the same as that in inactive tuberculosis (2.336 +/- 1.250). In comparison with the village community population surveyed, the average titer of anti-PPD antibodies in Behçet's disease patients was distinctly higher (P less than 0.001). These results indicate that tuberculosis may be etiologically related to Behçet's disease.

Cytokines regulating human B cell growth and differentiation

Utilizing a model system of anti-CD3-stimulated T cells, we have identified a potent B cell differentiation factor (BCDF) in the supernatant of these cells. This factor, 446-BCDF, appears to act on SAC-activated B cells inducing a 10- to 100-fold increase in Ig secretion. 446-BCDF has an apparent MW of 32 kDa and a pI of 6.0. Its activity cannot be inhibited by an anti-IL-6 antiserum, and activity is enhanced after passage over an anti-IL-6 affinity column. 446-BCDF activity is detected in the 50 mM salt fraction eluted from a Mono Q column. This 50 mM fraction has the only activity detected after passage over an anti-IL-6 affinity column and migrates with an apparent pI of 6.0. Taken together these data suggest that 446-BCDF is a unique potent polyclonal human BCDF which may be a predominant factor regulating terminal B cell differentiation.

Antiviral activity of some natural and synthetic sugar analogues

A number of natural and synthetic sugar analogues have been tested for their antiviral activity, using an influenza virus strain as a model. Hemagglutinating titres (HA) and cytopathic effect (CPE) were surveyed to estimate the virus production. It was found that introduction of the benzyl group into these sugars generally causes them to become antivirally active. Substitution with methyl, acetyl, uridyl and thiocyanyl groups or derivatization with azido, isopropylidene and benzylidene groups were without effect. All sugars containing the 2-deoxy-2-acetamido group were inactive.

Elevated cytosolic Ca2+ activates phospholipase D in human platelets

We have examined the activation of phospholipase D in human platelets treated with alpha-thrombin. When incubated with 1-O-[9,10-3H2]hexadecyl-2-lysophosphatidylcholine (PtdCho) and 1-alkyl-[32P]lysoPtdCho for 2 h, platelets formed 3H/32P-labeled PtdCho in a ratio of 11:1. After incubation of such labeled platelets with alpha-thrombin for 5 min, increased accumulation of 3H/32P-labeled phosphatidic acid (PtdOH) was detected in the same ratio, indicating the action of phospholipase D. The Ca2+ ionophore A23187 and alpha-thrombin each stimulated the formation of labeled PtdOH as above in a time- and concentration-dependent manner, with only minor changes in labeled diglyceride. A23187 was able to cause increases in labeled PtdOH comparable to those observed with alpha-thrombin. beta-Phorbol 12,13-dibutyrate, an activator of protein kinase C, only slightly stimulated the accumulation of labeled PtOH. The protein kinase C inhibitor, staurosporine, totally blocked these changes but only slightly inhibited the increases in labeled PtdOH promoted by alpha-thrombin. These results suggest that an increase in intracellular Ca2+, rather than protein kinase C activity, is a major factor regulating phospholipase D in platelets exposed to alpha-thrombin. We have also examined the relative contributions of phospholipase D and diglyceride kinase (following phospholipase C action) to PtdOH accumulation in [32P]Pi-labeled platelets by comparing the 32P-specific radioactivities of PtdOH, PtdCho, and metabolic gamma-ATP in control and alpha-thrombin-exposed platelets. Based on these determinations, we conclude that 13 and 87% of incremental PtdOH in human platelets exposed to alpha-thrombin arises via phospholipase D acting on PtdCho and phospholipase C/diglyceride kinase, respectively.

[Experimental study on induction of lung cancer in hamster by fifteen chemical elements in the industrial dust from Yunnan Tin and other mines]

To exclude the carcinogenicity of trace radioactive elements in the mine powder and flue dust and clarify those inorganic chemical elements related to carcinogenesis of lung cancer, 15 non-radioactive inorganic chemical elements (CM1) responsible for mutagenesis, tumorigenesis and promotion of cancer from mine powder and flue dust were mixed for Ames test and carcinoma-inducing-experiment in animals. The results were as follows: 1. Ames test of CM1 showed positivity. 2. Lung cancer-inducing-experiment of CM1 in the hamster was successful with an incidence of 8.8% whereas in the control group, no lung cancer developed which showed that CM1 was related to the development of lung cancer. 3. Hyperplastic cells under light microscope showed Type II alveolar cells and Clara cells under electron microscope. It is possible that hyperplastic, precancerous and malignant cells in the lung are derived from these two kinds of cells. One case of multiple microcarcinoma was found in this experiment.

[Rapid identification of Mycobacterium tuberculosis and other mycobacteria with Mycobacterium tuberculosis whole chromosomal DNA probe]

The dot-blots containing DNA isolated from nonmycobacterial and mycobacterial microorganisms were hybridized with 32P-labeled M. tuberculosis whole chromosomal DNA at the various temperatures. The probe did not cross-hybridize to DNA of nonmycobacterial microorganisms (E. coli, Plasmid pUC19, Nocardia asteriodes), nor with DNA from all mycobacteria tested except M. bovis BCG under the higher temperature conditions. Microorganisms could also be directly spotted and lysed on nitrocellulose filters and used for hybridization thus making this technique suitable for clinical diagnosis.

Mortality of population in China and Japan: a comparative analysis

The author compares mortality in China and Japan from 1950 to 1985 and analyzes the differences between the two countries. Consideration is given to sex differences, regional differences, and trends in the major causes of death. The analysis shows "the gap between China and Japan in the health standards of the population [and also suggests] a course for [reducing] mortality of the Chinese population.... There is great potential...of reducing infant mortality, especially for female infants....Moreover, the further control of infectious diseases can still play a major role in raising the average life expectancy of the Chinese population in the years ahead."

Alteration by perfluorodecalin of hepatic metabolism and excretion of phenobarbital

The bile duct was cannulated in rats that had been infused intravenously with an emulsion of perfluorodecalin at intervals from 2 to 34 weeks earlier. After injection of [14C]phenobarbital, urine and bile were collected during the next 24 hr and were analyzed for phenobarbital and its metabolites. There was a decrease in the biliary excretion of phenobarbital and its metabolites for several weeks after infusion of perfluorodecalin, but conjugation of the metabolites was not decreased. The reduced excretion returned to normal after about 20 weeks.

Effects of intravenous emulsified perfluorochemicals on hepatic cytochrome P-450

Intravenous infusion of emulsified perfluorodecalin in rats caused a large increase in hepatic cytochrome P-450 concentration which persisted for many weeks. In contrast, hepatic cytochrome P-450 concentration was not changed significantly after infusion of perfluorotributylamine, but subsequent administration of phenobarbital caused the usual increase of cytochrome P-450. The cytochrome P-450 activity for demethylation of benzphetamine was decreased slightly after perfluorodecalin but was unchanged after perfluorotributylamine. The difference in the effects of these perfluorochemicals on hepatic cytochrome P-450 may be related to the difference in the time these compounds are retained in the liver.

Prolonged cardiac arrest and resuscitation in dogs: brain mitochondrial function with different artificial perfusion methods

Clinical techniques for artificial perfusion have not previously been examined directly for their effects on brain high-energy metabolism. Our study involved 24 large mongrel dogs that were anesthetized, instrumented for central venous intravenous access, and subjected to craniotomy to expose the dura and underlying parietal cortex. The animals were divided into the following six experimental groups of four animals each: nonischemic controls; 15-minute cardiac arrest without resuscitation; 45-minute cardiac arrest without resuscitation; 15-minute cardiac arrest plus 30 minutes resuscitation with conventional cardiopulmonary resuscitation (CPR); 15-minute cardiac arrest plus 30 minutes resuscitation with interposed abdominal compression (IAC) CPR; and 15-minute cardiac arrest plus 30 minutes resuscitation with internal cardiac massage. Cardiac arrest was induced by central venous injection of KCl 0.6 mEq/kg, and it was confirmed by continuous ECG monitoring. The three active resuscitation models included administration of NaHCO3 and epinephrine, but no attempt was made to restart the heart by defibrillation during resuscitation. At the indicated time in each group, a 4- to 5-g sample of brain was removed through the craniotomy, immediately cooled to 0 C and processed for isolation of mitochondria. The mitochondria were studied for their content of superoxide dismutase and for quantitative oxygen consumption with glutamate/malate substrate during resting and ADP-stimulated respiration. Our results show a significant drop in brain mitochondrial superoxide dismutase activity during the first 15 minutes of cardiac arrest. There is minimal injury to brain mitochondrial oxygen consumption during both 15 and 45 minutes of complete ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)