Effects of chronic alcohol consumption on the cholinergic innervation of the rat hippocampal formation as revealed by choline acetyltransferase immunocytochemistry

The specific aim of this study was to evaluate whether the cholingeric innervation of the hippocampal formation is affected by chronic alcohol consumption in the rat. Choline acetyltransferase-immunoreactive fibres and neurons were analysed in both alcohol-fed and control rats using a monoclonal antibody against choline acetyltransferase and quantitative methods. We found a global reduction in the cholinergic plexus, which was more pronounced in the hippocampus proper than in the dentate gyrus. The areal density of choline acetyltransferase immunoreactive neurons was also reduced. Differences from controls in neuronal number were particularly striking in the stratum lacunosum moleculare of the regio superior, which is precisely the zone of the hippocampal formation where choline acetyltransferase immunoreactive neurons are more abundant in controls. In conclusion, our results show that prolonged ethanol consumption leads to a substantial reduction in the cholinergic innervation of the hippocampal formation, as there was a loss of cholinergic fibres and also an apparent loss of hippocampal cholingeric neurons. These findings may help to explain the cognitive dysfunctions observed after chronic alcohol consumption.

Development of a model for the delta opioid receptor pharmacophore. 1. Conformationally restricted Tyr1 replacements in the cyclic delta receptor selective tetrapeptide Tyr-c[D-Cys-Phe-D-Pen]OH (JOM-13)

A series of analogues of the conformationally restricted delta opioid receptor selective tetrapeptide Tyr-c[D-Cys-Phe-D-Pen]OH (JOM 13) was prepared in which the conformationally labile Tyr residue was replaced with several less flexible tyrosine analogues. Among these tyrosine analogues were the bicyclic structures 1,2,3,4-tetrahydro-7-hydroxyisoquinoline-3-carboxylic acid (HO-Tic), 2-amino-6-hydroxytetralin-2-carboxylic acid (Hat), and 2-amino-5-hydroxyindan-2-carboxylic acid (Hai) in which rotations about the C alpha-C beta and C beta-C gamma bonds are restricted due to cyclization of the side chain to the backbone. Also examined were analogues in which tyrosine was replaced with either trans-3-(4'-hydroxyphenyl)proline (t-Hpp) or cis-3-(4'-hydroxyphenyl)proline (c-Hpp), residues in which rotations about C alpha-C beta, but not C beta-C gamma, are restricted. Both the t-Hpp1 and c-Hpp1 analogues displayed delta receptor binding affinity similar to the parent Tyr1-containing peptide, while the D-Hat1, L-Hat1, and L-Hai1 analogues exhibited somewhat lower affinity. The results observed for the t-Hpp1 and c-Hpp1 analogues are particularly significant since these two residues have little accessible conformational space in common. Since the binding conformation of residue 1 must be included in this limited conformational intersection, its elucidation is facilitated. Bioassay results from guinea pig ileum and mouse vas deferens preparations are in general agreement with the binding results; however some potency discrepancies are observed. These discrepancies may reflect different selectivities among delta receptor subtypes for the analogues or may represent differing efficacies among these conformationally restricted peptides. The conformational properties of the parent tetrapeptide and the residue 1-modified analogues were studied by molecular mechanics computations. All these peptides share a common rigid tripeptide cycle with a single energetically preferred backbone conformation and three different conformers of the D-Cys, D-Pen disulfide bridge, two of which are observed in the solid state and in aqueous solution, as previously determined from X-ray crystallography and 1H NMR spectroscopy data (Lomize, A; et al. J. Am. Chem. Soc. 1994, 116, 429-436). All the peptides have similar sets of low-energy conformations of their common flexible elements, the Phe3 side chain and the peptide group between the first residue and the rigid tripeptide cycle. However, possible conformations of the first residue differ and depend on the covalent constraints incorporated into the side chain.(ABSTRACT TRUNCATED AT 400 WORDS)

Inhibitory effects of dietary curcumin on forestomach, duodenal, and colon carcinogenesis in mice

Curcumin (diferuloylmethane), a yellow pigment that is obtained from the rhizomes of Curcuma longa Linn., is a major component of turmeric and is commonly used as a spice and food-coloring agent. The inhibitory effects of feeding commercial grade curcumin (77% curcumin, 17% demethoxycurcumin, and 3% bisdemethoxycurcumin) in AIN 76A diet on carcinogen-induced tumorigenesis in the forestomach, duodenum, and colon of mice were evaluated. Administration p.o. of commercial grade curcumin in the diet inhibited benzo(a)pyrene-induced forestomach tumorigenesis in A/J mice, N-ethyl-N'-nitro-N-nitrosoguanidine-induced duodenal tumorigenesis in C57BL/6 mice, and azoxymethane (AOM)-induced colon tumorigenesis in CF-1 mice. Dietary commercial grade curcumin was given to mice at: (a) 2 weeks before, during, and for 1 week after carcinogen administration (during the initiation period); (b) 1 week after carcinogen treatment until the end of the experiment (during the postinitiation period); or (c) during both the initiation and postinitiation periods. Feeding 0.5-2.0% commercial grade curcumin in the diet decreased the number of benzo(a)pyrene-induced forestomach tumors per mouse by 51-53% when administered during the initiation period and 47-67% when administered during the postinitiation period. Feeding 0.5-2.0% commercial grade curcumin in the diet decreased the number of N-ethyl-N'-nitro-N-nitrosoguanidine-induced duodenal tumors per mouse by 47-77% when administered during the postinitiation period. Administration of 0.5-4.0% commercial grade curcumin in the diet both during the initiation and postinitation periods decreased the number of AOM-induced colon tumors per mouse by 51-62%. Administration of 2% commercial grade curcumin in the diet inhibited the number of AOM-induced colon tumors per mouse by 66% when fed during the initiation period and 25% when fed during the postinitiation period. The ability of commercial grade curcumin to inhibit AOM-induced colon tumorigenesis is comparable to that of pure curcumin (purity greater than 98%). Administration of pure or commercial grade curcumin in the diet to AOM-treated mice resulted in development of colon tumors which were generally smaller in number and size as compared to the control group of AOM-treated mice. These results indicate that not only did curcumin inhibit the number of tumors per mouse and the percentage of mice with tumors but it also reduced tumor size. Histopathological examination of the tumors showed that dietary curcumin inhibited the number of papillomas and squamous cell carcinomas of the forestomach as well as the number of adenomas and adenocarcinomas of the duodenum and colon.

Characterization of the monocyte-specific esterase (MSE) gene

Carboxylic esterases are widely distributed in hematopoietic cells. Monocytes express the esterase isoenzyme (termed 'monocyte-specific esterase', MSE) that can be inhibited by NaF in the alpha-naphthyl acetate cytochemical staining. We examined the expression of MSE in normal cells and primary and cultured leukemia-lymphoma cells. The MSE protein was demonstrated by isoelectric focusing (IEF); MSE mRNA expression was investigated by Northern blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). The following samples were positive for MSE protein and Northern mRNA expression: 20/24 monocytic, 4/32 myeloid, and 1/20 erythroid-megakaryocytic leukemia cell lines, but none of the 112 lymphoid leukemia or lymphoma cell lines; of the normal purified cell populations only the monocytes were positive whereas, T, B cells, and granulocytes were negative; of primary acute (myelo) monocytic leukemia cells (CD14-positive, FAB M4/M5 morphology) 14/20 were Northern mRNA and 11/14 IEF protein positive. RT-PCR revealed MSE expression in 29/49 Northern-negative lymphoid leukemia-lymphoma cell lines. The RT-PCR signals in monocytic cell lines were on average 50-fold stronger than the mostly weak trace expression in lymphoid specimens. On treatment with various biomodulators, only all-trans retinoic acid significantly upregulated MSE message and protein levels but could not induce new MSE expression in several leukemia cell lines; lipopolysaccharide and interferon-gamma increased MSE expression in normal monocytes. Analysis of DNA methylation with sensitive restriction enzymes showed no apparent regulation of gene expression by differential methylation; the MSE gene is evolutionarily conserved among mammalian species; the half-life of the human MSE transcripts was about 5-6 h. The extent of MSE expression varied greatly among different monocytic leukemia samples. However, the MSE overexpression in a significant number of specimens was not associated with gene amplification, gross structural rearrangements or point mutations within the cDNA region. Taken together, the results suggest that MSE expression is not absolutely specific for, but strongly associated with cells of the monocytic lineage; MSE is either not expressed at all or expressed at much lower levels in cells from other lineages. The biological significance, if any, of rare MSE messages in lymphoid cells detectable only by the hypersensitive RT-PCR remains unclear. Further studies on the regulation of this gene and on the physiological function of the enzyme will no doubt be informative with respect to its striking overexpression in some malignant cells and to a possible role in the pathobiology of monocytic leukemias.

Yunnanxane and its homologous esters from cell cultures of Taxus chinensis var. mairei

From cell cultures of Taxus chinensis var. mairei, yunnanxane [2 alpha, 5 alpha, 10-beta triacetoxy-14 beta-(2'-methyl-3'-hydroxyl)-butyryloxy-4(20),11-taxadiene, [1], and four new homologous esters, 2 alpha, 5 alpha, 10 beta, 14 beta- tetra-acetoxy-4(20),11-taxadiene [2], 2 alpha, 5 alpha, 10 beta- triacetoxy-14 beta-propionyloxy-4(20),11-taxadiene [3], 2 alpha, 5 alpha, 10 beta- triacetoxy-14 beta-isobutyryloxy-4(20),11- taxadiene [4], and 2 alpha, 5 alpha, 10 beta- triacetoxy-14 beta-(2'-methyl)-butyryloxy-4(20),11- taxadiene [5] have been isolated. Their structures were determined by spectroscopic methods.

Transient increase in expression of GAD65 and GAD67 mRNAs during postnatal development of rat spinal cord

Gamma-aminobutyric acid (GABA) is thought to be one of the classic neurotransmitters acting as a developmental signal. To understand the role for GABA in development, we investigated the expression of transcripts encoding two forms of the GABA-synthesizing enzyme glutamate decarboxylase (GAD65 and GAD67) in the cervical enlargement of the rat spinal cord at successive postnatal days--P0, P7, P14, P21, and P90 (adult)--by using in situ hybridization histochemistry. Cells hybridized with two oligonucleotide probes designed to detect GAD65 and GAD67 mRNAs were widely distributed in all laminae, except in motoneurons of the spinal cord. The integrated densities of hybridization signals were measured across all layers of the gray matter. The relative number of GAD mRNA-labeled cells was determined within each of four regions: laminae I-III, laminae IV-VI, laminae VII and VIII, and lamina X. There was a transient increase in both the integrated density and the relative number of hybridized cells between P7 and P14, after which there was a marked decline to adult levels (lowest). An overall decrease in the number of GAD mRNA-labeled cells was evident in all layers, but a dramatic drop occurred in a subpopulation of cells within ventral portions of the spinal cord. The distribution patterns and postnatal changes in expression of the mRNAs encoding GAD65 and GAD67 were similar and closely paralleled reported changes in the abundance of GAD65 and GAD67 proteins and their product, GABA. Transient increases in GAD mRNA expression during the early postnatal period coincide with, and may be linked to, synapse formation and synapse elimination of the developing spinal cord.

Expression of the FLT3 gene in human leukemia-lymphoma cell lines

The FLT3 gene encodes a protein that appears to function as a receptor for a hematopoietic growth factor; together with the KIT and FMS receptors, FLT3 belongs to the superfamily of receptors with tyrosine kinase activity. We examined the expression of FLT3 mRNA in 36 human leukemia-lymphoma cell lines using Northern blot analysis. FLT3 transcripts were found in seven of seven pre B-ALL cell lines (derived from cases with pre B-acute lymphoblastic leukemia or chronic myeloid leukemia in lymphoid blast crisis), and in one of six B-cell lines (namely in a cell line established from a hairy cell leukemia). FLT3 message was not detected in five T-cell, five myeloid, four monocytic, four erythroid and five megakaryocytic cell lines. Two major mRNA species were expressed differentially by positive cell lines. KIT mRNA expression was also investigated in the same panel of cell lines, but was found only in cell lines with erythroid and megakaryocytic features (and not in any of the FLT3-positive cell lines). The pattern of expression of FLT3 contrasts with the transcription of FMS and KIT and suggests that the FLT3 product may play a role primary in immature lymphoid cells.

c-kit expression in human megakaryoblastic leukemia cell lines

A panel of 164 continuous human leukemia-lymphoma cell lines was analyzed for expression of c-kit using Northern blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). The c-kit transcripts were detectable in cell lines assigned to the myeloid (in 7 of 29 by Northern blotting and in 4 of 8 by RT-PCR), monocytic (in 1 of 24 by Northern blotting and in 3 of 6 by RT-PCR), erythroid (in 6 of 8 by Northern blotting and in 5 of 5 by RT-PCR), and megakaryoblastic (in 10 of 10 by Northern blotting) lineages, c-kit expression was not seen by Northern blotting or RT-PCR analysis in any of the 93 lymphoid leukemia, myeloma, or lymphoma cell lines. Treatment of four megakaryoblastic cell lines with protein kinase C activators (phorbol ester 12-O-tetradecanoylphorbol 13-acetate and Bryostatin 1) led to terminal differentiation as assessed by morphologic alterations, changes in the surface marker profile, and growth arrest. These effects were associated with enhanced c-kit mRNA expression. Exposure to all-trans retinoic acid down-regulated c-kit mRNA levels, while simultaneously causing morphologic alterations in all four cell lines. Stimulation with growth factors (interleukin-3, granulocyte macrophage-colony stimulating factor, and insulin-like growth factors I and II), used to assess any role of c-kit in proliferative processes, did not lead to significant upregulation or downregulation of c-kit expression. The finding of constitutive and high expression of c-kit mRNA in all megakaryoblastic leukemia cell lines and its modulation by various reagents might further contribute to the understanding of megakaryopoietic proliferation, differentiation, and leukemogenesis.

[A practical method of whole mount TEM sample preparation and the study of nuclear matrix-intermediate filament scaffolds in K562 cells]

We applied culture plates with bored holes covered with FORMVAR and coated with carbon, to replace the gold grids used in conventional whole mount TEM study. Human erythroleukemia cell line K562 cells plated on the plate surface were extracted using a modified protocol to study scaffolds of nuclear matrix (NM) and intermediate filament (IF). The NM of the K562 cells was found to be composed of interweaving filaments of different diameters, while the cytoplasmic IF were mainly distributed in a radialized pattern. Compared with other techniques of whole mount TEM sample preparations, this one is much more practical and economical, yielding clear NM-IF structures with few artifacts. Study of NM-IF scaffolds in K562 cells might provide a basis for further elucidation of the involvement of NM-IF in the denucleation of mammalian erythroblasts.

Sensitivity of different methods for the detection of myeloperoxidase in leukemia cells

We examined the sensitivity of different myeloperoxidase (MPO) detection methods in leukemia cell lines. To this end the MPO-positive acute promyelocytic leukemia cell line NB-4 was diluted into cell populations of the MPO-negative myeloma cell line MM-1 at different ratios. MPO protein was identified by classical cytochemical staining and by a specific anti-MPO monoclonal antibody in an immunofluorescent reaction. Cytochemical staining detected 1% positive cells among 99% negative cells. Careful, but time-consuming observation enabled the detection of positive cells in even higher dilutions. At least a 10-fold increase in sensitivity was achieved with the immunofluorescent method, as brightly fluorescent cells are more amenable for a screening of slides at lower microscopic magnification than the cytochemically visualized cells. MPO mRNA expression was examined in whole cell populations by Northern blotting (maximal sensitivity 1%), a reverse transcriptase-polymerase chain reaction (RT-PCR) amplification assay (sensitivity 0.1%), and by RT-PCR followed by Southern blotting (sensitivity 0.05%). The high sensitivity of PCR-based techniques is offset by the fact that these methods do not allow for the identification and further characterization of the individual, MPO-positive cells. Thus, methods examining bulk populations require homogeneous cell samples in order to avoid false-positivity stemming from a few residual bystander cells. The five different techniques were used to determine the status of MPO expression in 20 randomly chosen leukemia cell lines of myelomonocytic origin. In 11 cell lines (8 positive and 3 negative) all five tests provided concordant results. Three cell lines were Northern-negative, but RT-PCR-positive and MPO protein-positive suggesting that Northern blot analysis is the least sensitive tool. Six cell lines were devoid of MPO protein, at least according to the methods used here, but trace expression of MPO message was documented by PCR. All five techniques have advantages and drawbacks and must be carefully selected in order to obtain useful data. The detection of MPO is of experimental and clinical importance in the distinction of myeloid from lymphoid leukemias, and in the lineage assignment of apparently biphenotypic or unclassifiable cases.

Inhibition of skin tumorigenesis by rosemary and its constituents carnosol and ursolic acid

A methanol extract of the leaves of the plant Rosmarinus officinalis L. (rosemary) was evaluated for its effects on tumor initiation and promotion in mouse skin. Application of rosemary to mouse skin inhibited the covalent binding of benzo(a)pyrene [B(a)P] to epidermal DNA and inhibited tumor initiation by B(a)P and 7,12-dimethylbenz[a]anthracene (DMBA). Topical application of 20 nmol B(a)P to the backs of mice once weekly for 10 weeks, followed 1 week later by promotion with 15 nmol 12-O-tetradecanoylphorbol-13-acetate (TPA) twice weekly for 21 weeks, resulted in the formation of 7.1 tumors per mouse. In a parallel group of animals that were treated topically with 1.2 or 3.6 mg of rosemary 5 min prior to each application of B(a)P, the number of tumors per mouse was decreased by 54 or 64%, respectively. Application of rosemary to mouse skin also inhibited TPA-induced ornithine decarboxylase activity, TPA-induced inflammation, arachidonic acid-induced inflammation, TPA-induced hyperplasia, and TPA-induced tumor promotion. Mice initiated with 200 nmol DMBA and promoted with 5 nmol TPA twice weekly for 19 weeks developed an average of 17.2 skin tumors per mouse. Treatment of the DMBA-initiated mice with 0.4, 1.2, or 3.6 mg of rosemary together with 5 nmol TPA twice weekly for 19 weeks inhibited the number of TPA-induced skin tumors per mouse by 40, 68, or 99%, respectively. Topical application of carnosol or ursolic acid isolated from rosemary inhibited TPA-induced ear inflammation, ornithine decarboxylase activity, and tumor promotion. Topical application of 1, 3, or 10 mumol carnosol together with 5 nmol TPA twice weekly for 20 weeks to the backs of mice previously initiated with DMBA inhibited the number of skin tumors per mouse by 38, 63, or 78%, respectively. Topical application of 0.1, 0.3, 1, or 2 mumol ursolic acid together with 5 nmol TPA twice weekly for 20 weeks to DMBA-initiated mice inhibited the number of tumors per mouse by 45-61%.

[Experimental gene transfer study using anucleated reticulocytes as target cells]

We report here a novel approach to introduce reporter beta-galactosidase genes into anucleated rabbit reticulocytes. The results indicate that the beta-galactosidase gene was expressed to certain degree in the cytoplasm of the reticulocytes. Our study has provided a useful model system for gene expression studies in anucleated eukaryotic cells.

Analysis of the anatomical distribution of GAD67 mRNA encoding truncated glutamic acid decarboxylase proteins in the embryonic rat brain

During development of the central nervous system (CNS) the gene that encodes the 67 kDa form of glutamic acid decarboxylase (GAD) undergoes alternative splicing. The alternatively spliced variants include an exon (referred to as ES, for embryonic stop) that contains a premature stop codon. The detection of mRNA containing the ES exon in embryonic rat brain has been previously reported (Proc. Natl. Acad. Sci., 87 (1990) 8771-8775). We have used in situ hybridization to identify the anatomical distribution of ES mRNA in the embryonic rat brain during two stages of development, embryonic day 17 (E17) and E20. At E17, GAD67 mRNA was expressed in several CNS regions that were destined to contain GABAergic neurons when mature. ES transcripts were predominantly localized to ventricular zones and other regions associated with populations of proliferative cells at E17 and E20. At both ages, however, the alternatively spliced variants were also detected in regions of brain associated with migratory or post-mitotic neurons. GAD67 transcripts that did not include the ES exon were localized to anatomical areas that contained post-mitotic, and often post-migratory neurons. The temporal and spatial disappearance of mRNA containing the ES exon generally followed a caudal-to-rostral gradient which paralleled neuronal terminal mitosis and differentiation.

New bioactive taxoids from cell cultures of Taxus baccata

Four new taxoids were isolated from cell cultures of Taxus baccata. Their structures were elucidated by spectroscopic analyses. Two were the aglycones corresponding to previously isolated 7-O-xylosides of taxol C [1] and 10-deacetyltaxol C [2]. The third [3] had an N-methylated side-chain, while the fourth, named taxcultine [4], contained an n-propyl group on the side-chain. All four compounds actively promoted tubulin assembly. Taxol C [1] showed potent and selective cytotoxicity in the NCI human cell line screen.

Computerized long-term trending of respiratory parameters

This paper presents a program that analyzes data recorded from a Puritan-Bennett 7200a mechanical ventilator. The program generates graphs of major ventilatory parameters, as well as the derivatives of the parameters, such as respiratory rate and minute volume with respect to time. The program also creates a series of reports that summarizes setting changes, alarm violations and resets, and lung mechanics maneuvers during the process of respiratory therapy. These graphs and reports provide clinicians with information, which was not captured for review before, in an organized format allowing them to easily identify trends and, in some cases, events that may affect the patient. The results of a clinical study are also presented. The study was designed to determine the effect of routine patient care on the primary and derived respiratory data so that a correct interpretation of the recorded data could be made. The study showed that the data acquisition program was not sensitive to routine bedside activities, and some significant events, such as patient disconnects, are identifiable in a timely manner and with good accuracy.

Ontogeny of GABAA receptor subunit mRNAs in rat spinal cord and dorsal root ganglia

Relatively little is known about the development of GABAA receptor subunits and their gene expression in mammalian spinal cord. The expression of mRNAs encoding 13 GABAA receptor subunits (alpha 1-6, beta 1-3, gamma 1-3, and delta) in embryonic, postnatal, and adult rat spinal cord and dorsal root ganglia (DRG) cells were studied by in situ hybridization and reverse transcription-polymerase chain reaction (RT-PCR) analysis. Both techniques revealed the presence of all subunit mRNAs originally found in the rat brain, except for alpha 6, which was not detectable, and delta, which was weakly detected only by RT-PCR. Two anatomically distinctive sets of subunit mRNAs were found by in situ hybridization within the ventricular zone (VZ) and mantle zone (MZ). The trio of alpha 4, beta 1, and gamma 1 subunit mRNAs emerged exclusively in neuroepithelial cells at embryonic day 13 (E13) and remained detectable in the VZ until E17. In the MZ, beta 3 subunit mRNA was first detected at E12, while alpha 2, alpha 3, alpha 5, beta 2, gamma 2, and gamma 3 transcripts appeared at E13. Expressions of the subunit mRNAs in the MZ rapidly increased and expanded in a ventrodorsal sequence from motoneurons to dorsal horn neurons before reaching a peak in the late embryonic/early postnatal period. The mRNA expressions declined during postnatal development, by region-selective depletion, with alpha 4, alpha 5, beta 1, beta 2, gamma 1, and gamma 3 subunit mRNAs becoming barely detectable. In contrast, alpha 2, alpha 3, beta 3, and gamma 2 transcripts persisted into adulthood with distinct anatomical distributions. RT-PCR analysis revealed unique developmental patterns in the intensities of PCR products, most of which were in good agreement with developmental changes in the densities of hybridized mRNA signals. However, RT-PCR amplified minute amounts of mRNAs for alpha 1, alpha 4, alpha 5, beta 1, beta 2, gamma 1, gamma 3, and delta subunits in adults, which were not found in film autoradiograms, but could be detected in a few grain-positive cells in emulsion-dipped sections. DRG cells expressed alpha 2, alpha 3, alpha 5, beta 2, beta 3, and gamma 2 subunit mRNAs during embryogenesis but only alpha 2, beta 3, and gamma 2 subunit mRNAs were reliably detected in the adult.(ABSTRACT TRUNCATED AT 400 WORDS)

Modulation of gene expression in the acute promyelocytic leukemia cell line NB4

The human leukemic cell line NB4 was derived from a patient with acute promyelocytic leukemia and is characterized by a specific 15;17 chromosomal translocation. We analyzed the response of NB4 and HL-60 cells to the biomodulators all-transretinoic acid (ATRA), vitamin D3 (Vit D3) and the protein kinase C agonists bryostatin 1 (Bryo 1) and phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA). HL-60 cells were used for comparison being arrested at the myeloblastic-promyelocytic stage, but lacking the t(15;17) abnormality. In most experiments Vit D3 was only weakly or not at all effective. The other three reagents effectively slowed or stopped the proliferation of the cells in suspension. Associated with this proliferation arrest was the cell differentiation along the myeloid cell lineages: ATRA modulated morphological features indicative of granulocytic differentiation; Bryo 1 and TPA caused also distinct morphological changes. The inducers up-regulated the expression of CD11b (without changing the surface expression of other markers, e.g. CD13, CD14, CD15, CD33, CD68, HLA-DR) and completely down-regulated the originally strong expression of myeloperoxidase and c-myc at the mRNA level. Thus, ATRA- or protein kinase C activator-induced differentiation involved changes associated with maturational processes. Induction of terminal differentiation of leukemic cells by physiological or pharmacological modulators may be able to control the growth of the malignant cells and has therapeutic implications.

Expression and modulation of annexin VIII in human leukemia-lymphoma cell lines

Annexin VIII is a calcium- and phospholipid-binding protein with anticoagulant activity. Annexin VIII mRNA was found to be specifically expressed in acute promyelocytic leukemia (APL) cells; it was not found in other types of acute myeloid leukemia (AML) nor in lymphoid malignancies. Using Northern blot analysis we investigated annexin VIII expression in 142 continuous human leukemia and lymphoma cell lines at the mRNA level. While the only APL cell line, NB-4, was indeed positive, other cell lines also displayed annexin VIII mRNA: 4/22 myeloid cell lines, 8/23 monocytic cell lines, 2/8 megakaryoblastic cell lines, 5/26 lymphoma-derived cell lines, 2/10 myeloma cell lines and 1/44 lymphoid leukemia cell lines. The strongest expression was seen in NB-4 and in the Hodgkin's disease derived cell line HDLM-2. Treatment of NB-4 cells with all-trans retinoic acid (ATRA) or the phorbol ester TPA induced terminal differentiation and down-regulated annexin VIII mRNA expression rapidly within a few hours; vitamin D3 was ineffective in this regard; the protein kinase C activator Bryostatin 1 up-regulated the expression. A panel of initially negative cell lines could not be induced by any of these biomodulators to transcribe annexin VIII. The half-life (T1/2) of annexin VIII mRNA was about 3-4 h using actinomycin D as transcription inhibitor. Treatment with ATRA or TPA prior to exposure to actinomycin shortened the T1/2 to 2 h while Bryostatin 1 extended it to 6h. As 21/141 non-APL cell lines were positive, annexin VIII cannot be used as a marker gene for APL cells; however, it might be associated with myelomonocytic or erythro-megakaryoblastic precursor cells. Annexin VIII gene expression might play a unique role in the proliferation and/or differentiation of leukemic cells and could be associated with the particular abnormal hemostasis of some leukemias.

[The study of intermediate filament organization of highly and poorly differentiated nasopharyngeal carcinoma cell lines]

By employing cytochemistry, immunocytochemistry, selective double extraction, whole mount electron microscopy and electrophoretic scanning quantitative analysis, the intermediate filaments (IF) of in vitro cultured nasopharyngeal carcinoma cell lines CNE-1 (highly differentiated) and CNE-2Z (poorly differentiated) have been studied. The results demonstrated that although the keratin-type IF were organized in a network pattern in both kinds of cells, significant differences could be observed between the two kinds of cells regarding IF organization, subtypes and quantity of keratin. The poorly differentiated cell line CNE-2Z exhibited a far more irregular and confused IF organization structure, and the content of keratin was lower while the variety of keratin subtypes was increased.

Taxoid side-chain structure determination by electrospray ionization tandem mass spectrometry

A method to elucidate the side-chain structure of novel taxoids was developed through use of electrospray ionization tandem mass spectrometry. The intact side-chain fragments produced by source fragmentation in the atmosphere-to-vacuum interface were further dissociated in the collision cell of a triple quadrupole mass spectrometer. The distinctive collisionally induced dissociation mass spectra were remarkably informative and gave detailed information on the side-chain functionalities. This technique proved valuable in the characterization of new taxoids produced by yew-tree cell cultures.

Myeloperoxidase: expression and modulation in a large panel of human leukemia-lymphoma cell lines

Myeloperoxidase (MPO) is found exclusively in the azurophilic granules (primary lysosomes) of normal myelomonocytic cells. Cytochemical staining for MPO activity is used clinically to distinguish myeloid from lymphoid leukemias. We studied the expression of MPO at the RNA and protein level in 140 continuous human leukemia-lymphoma cell lines using classical cytochemistry, immunofluorescent staining with a specific monoclonal antibody, Northern blot analysis, and a reverse transcription-polymerase chain reaction (RT-PCR) amplification assay. Seventy-eight lymphoid leukemia, myeloma, and lymphoma cell lines were negative; only 3 pre-B-acute lymphoblastic leukemia (ALL) cell lines were MPO-positive. Two of these MPO-positive pre-B-ALL cell lines showed a trace expression after RT-PCR and Southern blotting corresponding to 4% to 6% of the transcripts found in other positive myeloid cell lines. The third pre-B-ALL cell line was positive in Northern blots and cytochemical/immunofluorescent staining; however, only few cells were weakly positive in the latter assay. Although 15 of 59 cell lines assigned to the myeloid, monocytic, megakaryocytic, or erythroid lineages were MPO-positive in Northern blots, those 15 and 13 additional cell lines showed bands of mRNA after RT-PCR. MPO protein was detected in all 16 Northern-positive cell lines; on the other hand, there were 4 cell lines that were protein-positive, but Northern-negative. Differentiation induced by protein kinase C activators 12-O-tetradecanoylphorbol 13-acetate and Bryostatin 1 or by all-trans retinoic acid was associated with a decrease in MPO mRNA in all 7 initially positive cell lines studied, even leading to the complete absence of transcripts, but the enzymatic activity of the differentiated cells was only slightly less than that of unstimulated cells. MPO expression could not be induced in 10 initially negative cell lines. The half-life of MPO mRNA was found to be about 6 hours and was not shortened by prior exposure of the cells to the differentiation-inducing agents. These results confirm that MPO expression is mainly associated with myelomonocytic cells, but also underline the notion that MPO cannot be used as an absolutely lineage-specific marker for the distinction of leukemic cells. MPO can be used as an excellent parameter to characterize the various stages of normal and induced differentiation.

A transmembrane protein with a cdc2+/CDC28-related kinase activity is required for signaling from the ER to the nucleus

In eukaryotic cells, the accumulation of unfolded proteins in the endoplasmic reticulum (ER) triggers a signaling pathway from the ER to the nucleus. Several yeast mutants defective in this pathway map to the ERN1 gene, which protects cells from lethal consequences of stress by signaling for increased expression of BiP and other ER proteins. ERN1 encodes a 1115 amino acid transmembrane protein (Ern1p) whose glycosylated N-terminal portion is located inside microsomes and whose cytoplasmic C-terminal portion carries an essential protein kinase activity. We postulate that Ern1p is the proximal sensor of events in the ER and that binding of ligand causes transduction of information across the ER membrane, leading to activation of a specific set of transcription factors.

Analysis of taxol and related diterpenoids from cell cultures by liquid chromatography-electrospray mass spectrometry

Authentic taxanes (taxol, 10-deacetyltaxol, cephalomannine, 10-deacetylcephalomannine, baccatin III) and extracts from cell cultures derived from various yew tree species have been analyzed by microbore high-performance liquid chromatography (HPLC)-electrospray mass spectrometry (ESMS). All gave excellent positive-ion ES spectra with dominant protonated molecules at low nozzle-to-skimmer bias value (45 V). By increasing the voltage value to 85 V, fragmentation increased and structurally informative spectra were obtained. The fragments found were both of the C-13 side-chain and of the taxane ring, so their analysis gave important information about the taxane structure and any chemical modifications at different positions of the molecule. When tandem MS was used (argon gas, 25 eV collision energy), fragments similar to those obtained from collision-induced dissociation in the source were detected. The cell culture extracts were analyzed by microbore HPLC-ESMS and excellent spectra were obtained on 5-10 ng of separated compounds; even greater selectivity and sensitivity were obtained through use of selected-ion monitoring (SIM). With SIM, 100 pg of all taxanes could readily be detected. In the HPLC-ESMS mode, only 10% of the eluent was mass-analyzed, so 90% would be available for recovery through fraction collecting.

External craniofacial features, body size, and renal morphology in prenatal brachyrrhine mice

The Brachyrrhine (Br) semidominant mouse mutant provides a useful model for studying factors responsible for midfacial hypoplasia. In order to determine early morphogenetic events responsible for midfacial hypoplasia in these mice, prenatal mutants must be differentiated from nonaffected littermates. The purpose of this study was to determine whether prenatal offspring from Br matings could be separated morphologically into groups of normal or midfacially deficient embryos. Thirty embryos resulting from Br matings were collected between day 15 and birth (Theiler stages 23-27). Qualitative observations on craniofacial morphology as well as renal morphology and histology suggested that embryos segregated into two distinct groups. External craniofacial and body measurements, collected from the embryos, as well as renal volumes, determined from computerized reconstructions of the kidneys, were subjected to quantitative analyses. A discriminant function analysis segregated the sample into two groups based primarily on midfacial length and renal volume. Bivariate regression analysis showed that midfacial length and renal volume differed significantly, and cranial length marginally so, between the two groups. The results indicate that a proportion of prenatal offspring from Br matings exhibits midfacial and renal hypoplasia and that these animals segregate completely from nonaffected embryos.

A fluorescence quenching method for estimating chelating groups in chelate-conjugated macromolecules

A terbium-dipicolinic acid (Tb-DPA) fluorescence quenching method for estimating free chelating groups conjugated to protein molecules was developed. This method was based on competitive displacement of DPA from binding to terbium by stronger chelating groups such as diethylenetriaminepentaacetic acid (DTPA), EDTA, nitrilotriacetic acid (NTA), DTPA-conjugated bovine serum albumin (BSA-DTPA), or DTPA-conjugated immunoglobulin G (IgG-DTPA), resulting in a significant reduction in terbium fluorescence. The chelating ability of the tested reagent, from high to low, was in the following order: BSA-DTPA > DTPA > IgG-DTPA > EDTA, NTA. At low terbium concentrations, the reduction was linear for DTPA. This fluorescence quenching method was not only rapid, simple, and as accurate as conventional radiosotopic or chromatographic methods, but also sensitive and reproductible. The detection limit was 10 nM for DTPA. The interrun coefficient of variation was at most 8%. The advantage of this method over other indirect methods is that it reveals the actual chelating ability of the tested macromolecule, unencumbered by complicating factors such as trace metal contamination and dimer/polymer formation during conjugation.

Use of the gamma-ray perturbed angular correlation (PAC) technique for monitoring liposomal phospholipid bilayer integrity

A membrane labeling method based on the principle of gamma-ray perturbed angular correction (PAC) was developed to monitor the structural integrity of liposomal membranes. The reporter group was 111In(III) complexed with the lipophilic diethylenetriaminepentaacetic acid (DTPA) derivative of dipalmitoylphosphatidylethanolamine (DPPE) embedded in the phospholipid bilayers of small unilamellar liposomes. Using this method, complete chemical digestion of the constituent phospholipids in these DTPA-conjugated liposomes by phospholipase A2 or phospholipase C in the presence of Ca2+ was found not to be followed by an immediate disruption of the liposomal membrane. Compared with other methods, the method developed permits the continuous noninvasive monitoring of the microenvironment of the lipid bilayer at the molecular level. It may potentially be applicable to evaluate liposomal fusion, screen for penetration enhancers under development for enhancement in mucosal drug penetration, and monitor liposomal degradation within the living animal.

Inhibitory effect of green tea on the growth of established skin papillomas in mice

In 10 separate experiments, mice with established chemically induced or UV light-induced skin papillomas were treated continuously with green tea in the drinking water or with i.p. injections of a green tea polyphenol fraction or (-)-epigallocatechin gallate three times a week for 4-10 weeks. Partial tumor regression or > 90% inhibition of tumor growth, as measured by changes in tumor volume per mouse, was observed in 5 experiments, and marked inhibition of tumor growth (46-89%) was observed in 5 additional experiments. Treatment of the mice with green tea or green tea constituents had an inhibitory effect on body weight increases in several but not all of the studies. Examination of the data from all ten experiments revealed that complete tumor regression occurred in 14 of 346 papilloma-bearing mice (4%) that were treated with green tea in the drinking water or with i.p. injections of green tea constituents, whereas none of the 220 papilloma-bearing control mice treated with only vehicle exhibited complete tumor regression. These observations indicate that oral administration of green tea, i.p. administration of a green tea polyphenol fraction, or i.p. administration of (-)-epigallocatechin gallate inhibited the growth and/or caused the regression of established experimentally induced skin papillomas.

Neuroepithelial cells in the rat spinal cord express glutamate decarboxylase immunoreactivity in vivo and in vitro

It is unknown whether neuroepithelial cells in the mammalian central nervous system express neurotransmitter-synthesizing enzymes. In this study, expression of glutamate decarboxylase (GAD), the gamma-aminobutyric acid (GABA)-synthesizing enzyme, was examined in proliferative cells and postmitotic neuroblasts in embryonic rat spinal cord. Immunostaining coronal sections of the embryonic spinal cord with K2 antiserum, which recognizes GAD proteins encoded by the GAD67 gene, revealed intensely stained neuroepithelial cells in the basal plate at embryonic day (E) 13, in the intermediate plate between E 13-16, and last seen in the alar plate at E 16. Nissl counterstaining demonstrated that a small number of these GAD-immunoreactive cells adjacent to the neural tube lumen were mitotic. The ventral-to-dorsal gradient of GAD expression in precursor cells and postmitotic neuroblasts correlates anatomically and temporally with the sequential generation of motoneurons, commissural neurons, and interneurons in the dorsal horn. Some of these GAD-immunoreactive neuroepithelial cells may re-enter the mitotic cycle, while others are postmitotic neuroblasts presumably migrating to the intermediate zone to differentiate into young neurons. Double-immunostaining cells acutely dissociated from E 11-18 spinal cords with K2 and anti-bromodeoxyuridine antisera, following a bromodeoxyuridine pulse in vivo, revealed considerable numbers of DNA-synthesizing cells immunoreactive for GAD. The absolute number of double-stained cells peaked during E 12-15, coinciding with terminal cell division in most spinal neurons. These observations suggest that spinal neuronal precursors can synthesize GAD-related proteins prior to, or during, the terminal cell cycle. Although GAD immunoreactivity revealed by K2 antiserum was detected in proliferative cells and in migrating postmitotic neuroblasts, GABA immunoreactivity was never detectable in these cells. These early embryonic GAD-immunoreactive neuroepithelial cells may either synthesize levels of GABA that cannot be detected immunocytochemically, and/or express enzymatically inactive GAD-related proteins.

Transient expression of GABA immunoreactivity in the developing rat spinal cord

The development of GABAergic neurons in the spinal cord of the rat has been investigated by immunocytochemical staining of frozen sections with anti-gamma-aminobutyric acid (GABA) antiserum. In the cervical cord, GABA-immunoreactive fibers first appeared at embryonic day (E) 13 in the presumptive white matter within the ventral commissure, ventral funiculus, and dorsal root entrance zone, and in the ventral roots. There were no GABA-immunoreactive cell bodies detected at this age. By E14, motoneurons, the earliest generated spinal cells, were the first cell population to become GABA-immunoreactive at the cell body level. Thereafter, GABA-immunoreactive neurons increased progressively in number and extended from ventral to dorsal regions. GABA-immunoreactive relay neurons within lamina I of the dorsal horn were initially detected at E17. Interneurons in the substantia gelatinosa, the latest generated cells in the spinal cord, were also the last to express the GABA immunoreactivity at E18. Immunoreactive neurons peaked in intensity and extent at E18 and 19. GABA immunoreactivity was only detectable in neurons within the intermediate and marginal zones 1-3 days after they withdrew from the cell cycle. This contrasts to glutamate decarboxylase immunoreactivity, which is detected in precursor cells in the ventricular zone prior to, or during, withdrawal from the cell cycle. Toward the end of gestation, GABA immunoreactivity declined in intensity and extent. This regression began in the ventral horn of the cervical region and ended in the dorsal horn of the lumbosacral region. During the first week after birth, immunoreactivity in motoneurons and in many other neurons within the ventral horn, intermediate gray, and deeper layers of the dorsal horn disappeared, and only in those neurons predominantly within the superficial layers of the dorsal horn did it persist into adulthood. Thus, the expression and regression of GABA immunoreactivity in the spinal cord followed ventral-to-dorsal, rostral-to-caudal, and medial-to-lateral gradients. These observations indicate that the majority of embryonic spinal neurons pass through a stage of transient expression of GABA immunoreactivity. The functional significance of this transient expression is unknown, but it coincides with the period of intense neurite growth of motoneurons, sensory neurons, and interneurons, and of neuromuscular junction formation, suggesting that the transient presence of GABA may play an important role in the differentiation of sensorimotor neuronal circuits.

Electromagnetic field for a beam incident on two adjacent spherical particles

Through an application of our previously derived single spherical particle-arbitrary beam interaction theory, an iterative procedure has been developed for the determination of the electromagnetic field for a beam incident on two adjacent spherical particles. The two particles can differ in size and composition and can have any positioning relative to each other and relative to the focal point and propagation direction of the incident beam. Example calculations of internal and near-field normalized source function ( approximately |E|(2)) distributions are presented. Also presented are calculations demonstrating the effect of the relative positioning of the second adjacent particle on far-field scattering patterns.

The relationship between thalamocortical connections and stimulus-evoked metabolic activity in the ventroposterior nucleus of the monkey

Although a highly organized system of reciprocal projections exists between the cerebral cortex and the thalamus, the relationship of the thalamocortical projections to functional activity remains unclear. This study attempts to identify the correlation between thalamic relay cells and functional activity evoked in the ventroposterior nucleus (VP) of cynomolgus and squirrel monkeys. Wheatgerm agglutinin conjugated to horseradish peroxidase (WGA:HRP) was iontophoretically injected into physiologically determined sites in the somatosensory cortex, resulting in retrogradely labeled cells and anterogradely labeled terminals in corresponding somatosensory thalamic regions. In the same animals, 2-deoxyglucose (2DG) experiments were carried out 2 days later, using the somatic stimuli identified as best exciting the cortical neurons. Stimulation to the limbs produced crescent-shaped clusters of metabolic label arranged in a somatotopically organized fashion in the ventral posterior lateral nucleus (VPL). Following WGA:HRP injections into area 3b, the stimulus-evoked 2DG label was colocalized with the retrograde and anterograde tracer. This finding suggests that the location of stimulus-evoked metabolic activity can be predicted by the presence of transported WGA:HRP clusters.

Cholinergic manipulation alters stimulus-evoked metabolic activity in cat somatosensory cortex

The role of acetylcholine (ACh) in cerebral cortical activity has recently been reevaluated. It now seems clear that this neurotransmitter increases the magnitude of cortical responses. Although substantial information has been gathered regarding the role of ACh in sensory information processing, little is known about the participation of ACh in the organization of maps in the cerebral cortex. To address this issue, we used 2 methods to manipulate the supply of ACh in the somatosensory cortex of cats: 1) unilateral neurotoxic lesions of the basal forebrain and 2) unilateral topical applications of the cholinergic antagonist, atropine. For each experimental condition, the animal received an injection of 2-deoxyglucose (2DG) while identical somatic stimuli were delivered to the right and left forepaws. In the somatosensory cortex, the 2DG uptake most often occurred in the form of patches that extended from layer II to IV. When the patches were reconstructed into 2-dimensional maps of activity throughout the somatosensory cortex, they formed strips that ran in the rostrocaudal direction. The reconstructed maps revealed that the 2DG patterns in ACh-depleted and the normal cortex were similar in their overall topographic distribution. Depletion or antagonism of ACh, however, caused the stimulus-evoked metabolic label to be reduced in dimension and density. Measurements of background activity levels were obtained by using 1) cytochrome oxidase histochemistry or 2) metabolic activity values in regions of somatosensory cortex that were not specifically stimulated. This analysis indicated that background values in the ACh-depleted hemispheres were not different from those in the normal hemispheres. The absence of ACh therefore appears to reduce the cortical response to stimulation, while background activity values do not change. These observations indicate that ACh plays a significant role in the processing of sensory information and the organization of somatosensory cortical maps.

[Detection of antibodies to citric acid extract of skeletal muscle (CAE-ab) in the sera of patients with myasthenia gravis using indirect hemagglutination]

In this paper are described the method and results for the demonstration of the antibodies to citric acid extract of skeletal muscle (CAE-ab) in the sera from myasthenia gravis (MG) patients with or without thymoma, in patients with other diseases and in healthy controls by an indirect hemagglutination assay (IHA), were described. The CAE-ab titers were positive in 15 (71.43%) of the 21 MG patients with thymoma, the antibody titers ranging from 1:16 to 1:512. In the 35 MG patients without thymoma, as well as in the 32 healthy controls and 22 patients with other diseases, the antibody titers were all negative A statistically significant difference was found between the CAE-ab titers in the group of MG patients with thymoma and those in the other three groups. It was considered that IHA for the purpose of demonstrating CAE-ab could serve as a supplementary diagnostic method for early detection of thymoma in MG patients at an early stage.

Lesions of the basal forebrain alter stimulus-evoked metabolic activity in mouse somatosensory cortex

The role that acetylcholine plays in processing sensory stimuli is beginning to be characterized; however, morphological correlates of cholinergic effects on activity patterns in sensory cortex are not available. To study this problem, unilateral neurotoxic lesions that depleted the necortex of acetylcholine were made in the basal forebrains of mice. The aim of these experiments was to study the effect of cholinergic depletion on stimulus-evoked activity in the barrel field of the mouse somatosensory cortex. One month following the lesion, 2-deoxyglucose (2DG) experiments were conducted on the lesioned and on normal mice while the animal received bilateral stimulation to the C3 whisker. The tissue was processed for acetylcholinesterase and cytochrome oxidase histochemistry and 2DG autoradiography. Evaluation of the column-like 2DG label evoked in the somatosensory cortex revealed that the activity on the lesioned side was significantly reduced in dimension and intensity from that in the normal hemisphere. On the normal side, the activated barrels averaged 641 microns in tangential width, were 76.5% above background in density, and extended from lamina I-V. On the lesioned side, the activated barrels were 485 microns in tangential width, 65.4% above background in density, and extended from lamina II-V. In other cortical regions, outside the stimulus-evoked barrel field, 2DG activity values were similar on the normal and lesioned side. Additionally, both the pattern and intensity of the cytochrome oxidase staining within the barrel field displayed no differences in either hemisphere. These studies suggest that acetylcholine plays a significant role in the processing of somatosensory information. Neurotoxic lesions that diminish cortical cholinergic innervation cause a reduction of stimulus-evoked activity levels, while underlying metabolic activity is either not affected or recovers over time.

Spino-diencephalic relays through the parabrachial nucleus in the cat

Previous studies have shown that the spinal input to the parabrachial nucleus (PBN) in the cat is limited to certain portions of its lateral division 8,21,45. The purpose of the present study was to determine some of the output targets of PBN neurons located within this spinal terminal domain by means of single, double and triple light microscopic labeling strategies. Combinations of tracers included the retrograde transport of tritiated wheat germ agglutinin, wheat germ agglutinin conjugated with horseradish peroxidase (WGA-HRP) and Fluoro-Gold from the hypothalamus, amygdala or thalamus/zona incerta together with either the anterograde transport of WGA-HRP from the spinal cord or the degeneration of spinal terminals following spinal lesions. The results (summarized in Fig. 10) showed that the spinal terminal domain contains separable populations of neurons projecting to the thalamus/zona incerta and hypothalamus. Only a limited number of amygdala-projecting neurons was located in this domain. Evidence from several laboratories supports the conclusion that these potential spino-diencephalic relays are involved somehow in nociception. More information is needed, however, regarding differences in the response properties of these separable populations of spinal-recipient neurons before more specific hypotheses concerning the precise nature of their nociceptive functions can be formulated.

Spinal input to the parabrachial nucleus in the cat

The projections from the spinal cord to the parabrachial nucleus in the cat were investigated using both the degeneration method and the anterograde transport of wheat germ agglutinin-horseradish peroxidase conjugate. Both methods produced similar results. Spinal input to the parabrachial nucleus was bilateral, with a slight contralateral predominance. The termination area was localized predominantly in the dorsal part of the lateral parabrachial nucleus, with additional limited terminations in the Kölliker-Fuse subnucleus. Projections from different rostrocaudal levels of the spinal cord overlapped completely, suggesting that spinal input to the parabrachial nucleus is not topographically organized. Taking these results together with those of others indicating that spinal input to the parabrachial nucleus arises primarily from nociceptive-specific neurons in lamina I of the dorsal horn, it is concluded that the spinal projections to the parabrachial nucleus are likely to be involved in various generalized aspects of nociception.

An ultrastructural analysis of serotoninergic neurons in the nucleus raphe magnus of the rat

The synaptic organization of serotonin elements in the nucleus raphe magnus of adult rat was investigated by electron microscopic immunocytochemistry with an antiserum against serotonin itself. Immunoreactive somata in the nucleus raphe magnus were usually of the same size (7-15 microns) and showed similar cytological features as their unlabeled congeners. The serotonin perikarya were contacted by a few unlabeled axon terminals containing round synaptic vesicles, and gave rise to dendrites which often ran perpendicularly to the midline. These dendrites received many contacts from axon terminals containing round or pleomorphic synaptic vesicles, but themselves failed to show vesicular aggregates or membrane differentiations suggestive of synaptic specialization. Immunoreactive axon terminals were numerous and mostly contained round or pleomorphic vesicles. Several exhibited synaptic contacts on dendrites, but there were also others which did not show any synaptic membranous differentiation, even when followed in serial sections. Immunostained myelinated as well as unmyelinated axons could be observed. These results provide a first description of the morphology and synaptic organization of the serotonin neurons in adult rat nucleus raphe magnus.

Fine structure of the dorsal part of the nucleus submedius of the rat thalamus: an anatomical study with reference to possible pain pathways

The dorsal portion of the nucleus submedius of the rat thalamus receives spinal and trigeminal projections which may convey noxious inputs. The present study was undertaken to analyse the fine structure of the nucleus with particular reference to a possible trigemino-thalamo-prefrontal cortical pathway relaying in nucleus submedius. Presynaptic terminals in the dorsal portion of the nucleus submedius were classified into three broad categories usually observed in thalamic nuclei: "small round", "flat" and "large round" types. Axonal tracing using either anterograde transport of horseradish peroxidase or degeneration methods indicated that some "small round" terminals originate from the pre-frontal cortex. Some "large round" terminals were labelled from the trigeminal subnucleus caudalis. These "large round" terminals exhibited distinct morphological features when compared with trigeminal terminals in other thalamic nuclei. In particular they made synaptic contacts predominantly with dendritic protrusions and were surrounded by multilamellate astrocytic processes. Double-labelling experiments were performed by means of the combined retrograde transport of horseradish peroxidase and Wallerian degradation techniques. Terminals degrading after lesion of the trigeminal subnucleus caudalis contacted submedius neurons labelled retrogradely from the prefrontal cortex. These observations demonstrate the existence of a direct monosynaptically relayed pathway from subnucleus caudalis to prefrontal cortex which relays in the dorsal part of nucleus submedius.

Spinal and trigeminal projections to the parabrachial nucleus in the rat: electron-microscopic evidence of a spino-ponto-amygdalian somatosensory pathway

The fine structure of spinal and trigeminal projections to the parabrachial area (PB) of the rat was studied using either the anterograde transport of a lectin-peroxidase conjugate or the degeneration technique. Two morphologically different types of terminals were observed. Most labeled terminals contained round vesicles (R type) and formed asymmetrical synapses, usually with large dendrites. Others contained pleomorphic vesicles (P type) and usually made symmetrical contacts with large or medium-size dendrites. A double-labeling strategy was used, combining the retrograde labeling of PB neurons with lectin-peroxidase conjugate from the amygdala and the identification of degenerating terminals after lesions of spinal or trigeminal pathways. These experiments demonstrated that spinal and trigeminal terminals contact PB neurons that project to the central nucleus of the amygdala. The role of this spino(trigemino)-ponto-amygdalian pathway is discussed in relation to some aspects of pain.

The differential synaptic organization of the spinal and lemniscal projections to the ventrobasal complex of the rat thalamus. Evidence for convergence of the two systems upon single thalamic neurons

The synaptic organization of terminals originating either from the spinal cord (spinothalamic) or from the dorsal column nuclei (lemniscal) was investigated in the ventrobasal complex of the rat thalamus. Wheatgerm agglutinin conjugated to horseradish peroxidase was used as an anterogradely transported axonal tracer, using benzidine dihydrochloride as a chromogen for the identification by electron microscopy of spinal and lemniscal projections to the ventrobasal thalamus. A double anterograde tract tracing strategy, based labeling by wheatgerm agglutinin conjugated to horseradish peroxidase of spinal terminals and simultaneous visualization of lemniscal terminals identified by Wallerian degeneration induced by lesion of the neurons of origin in the dorsal column nuclei, was used to compare the postsynaptic elements contacted by the two pathways and to look for a possible convergence of the two pathways onto single thalamic neurons. Spinal and lemniscal terminals are large (2-2.5 microns mean average diameter) terminals containing several mitochondria and numerous rounded vesicles. A quantitative analysis of the mean average diameters of the terminals revealed that one could not differentiate between synapses formed by the two pathways on a morphological basis. Terminals of the two pathways make asymmetrical contacts (Gray type I) with dendrites of varying diameter, dendritic protrusions, and cell somata. A quantitative analysis of the least diameter of the postsynaptic elements demonstrates projections of the two systems to different, partially overlapping regions of thalamic neurons. Lemniscal terminals originating from the dorsal column nuclei frequently contact cell somata; axosomatic spinothalamic contacts are uncommon. In addition, lemniscal projections tend to contact more proximal dendrites than do spinal projections, and this differential synaptic organization is statistically significant. From a functional point of view, this differential synaptic organization might indicate that lemniscal inputs have greater influence than spinal inputs in affecting the activity of thalamic neurons. Labeled spinothalamic terminals contact the same dendritic profile as do degenerating lemniscal terminals in about 10% of single sections. Because the present study did not include a complete reconstruction of ventrobasal complex neurons of the thalamus or even regions of dendritic arbors, the degree of convergence is likely to be significantly underestimated. These findings indicate that the anatomical basis exists for an interaction between nociceptive and non-nociceptive somesthetic systems at the level of single ventrobasal neurons of the thalamus of the rat.

Synaptic glomeruli in the nucleus submedius of the rat thalamus

Synaptic glomeruli in the nucleus submedius of the rat are described and the source of some of the component terminals identified. The glomeruli consist of large terminals with round synaptic vesicles establishing Gray type I contacts with dendrites and surrounded by layers of astrocyte derived membranes. The astrocyte processes may be composed of cell membranes with minimal interventing cytoplasm or, less frequently, contain larger amounts of cytoplasm. Horseradish peroxidase injected into the trigeminal nucleus caudalis labels some of the large astrocyte-enclosed terminals in nucleus submedius.

Fine structure of the spinothalamic projections to the central lateral nucleus of the rat thalamus

The fine structure of labelled spinothalamic terminals in the central lateral nucleus has been studied in the rat following injection of wheat germ agglutinin-horseradish peroxidase into the spinal cord. Myelinated axons gave rise to the labelled terminals, which were large profiles which contained round vesicles, numerous mitochondria, and formed asymmetrical contacts with large dendrites or dendritic protrusions. These profiles are similar to those described in other somatosensory thalamic nuclei, and in many other nuclei of the thalamus.

Swallow syncope after aneurysmectomy of the thoracic aorta

A case of swallow syncope is presented and 30 previously reported cases from the literature in English are reviewed. A 67-year-old male developed syncope on swallowing 3 months after the resection of an aneurysm of the descending thoracic aorta. Electrocardiographic monitoring during eating demonstrated sinus bradycardia and sinus arrest with loss of consciousness. Neither Valsalva's maneuver nor carotid massage could produce bradycardia or syncope. Intravenous administration of edrophonium produced sinus bradycardia and the drinking of water by the patient after edrophonium administration brought about sinus bradycardia and sinus arrest with loss of consciousness. Sinoatrial node and atrioventricular node functions, evaluated by an atropine test, overdrive suppression test, and His bundle electrocardiogram were normal. No pathological changes were observed following a barium swallow. The patient was treated with a permanent pacemaker.

The overlap of spinothalamic and dorsal column nuclei projections in the ventrobasal complex of the rat thalamus: a double anterograde labeling study using light microscopy analysis

Projections from the spinal cord and the dorsal column nuclei (DCN) to the ventrobasal complex of the thalamus (VB) were studied in the rat by using double anterograde labeling strategy. This strategy was based on the injection of 3H-leucine into the DCN and of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) into the spinal cord and their subsequent transport. Adjacent 30-micron-thick sections were then processed differentially for autoradiography or for HRP by using tetramethyl benzidine (TMB) as a chromogen. Similar areas of the ventrobasal complex were labeled, in adjacent sections, after a large injection of 3H-leucine into the DCN and when wheat germ agglutinin-HRP had been injected in any part of the spinal cord. If, however, a small injection of the radioactive tracer was centered in the gracile nucleus and compared with an injection of WGA-HRP placed in the lumbar enlargement of the cord, the rostral and dorsal portions of the lateral VB were labeled from both sources. On the other hand, if tritiated leucine was injected into the cuneate nucleus, and WGA-HRP placed in the cervical enlargement, then the caudal and ventral portions of the lateral VB demonstrated overlap of both labels. The present results show that, in the rat, areas of termination of both the spinothalamic tract and the lemniscal pathway originating from the DCN overlap in the lateral VB. This overlap is somatotopically organized, thus indicating that the same area of the VB receives somatic inputs from one particular part of the body through both pathways. These results are discussed in comparison to those of comparable studies performed in the cat and in the monkey and with reference to the electrophysiological data that have demonstrated that, in the rat VB, neurons responding to noxious stimulation are intermingled with neurons exclusively responding to non-noxious stimulation.