Striatonigral GABA,dynorphin, substance P and neurokinin A modulation of nigrostriatal dopamine release: evidence for direct regulatory mechanisms

Summary The striatonigral pathway contains several neurotransmitters which may regulate the activity of the nigrostriatal dopamine projection in the rat. This was investigated by measuring extracellular dopamine levels in the striatum, using microdialysis, after injections of GABA (300 nmol/0.2 l), dynorphin A (0.5 nmol/0.2 l), substance P (0.07 mnol/0.2 l) or neurokinin A (0.09 nmol/0.2 l) into the ipsilateral substantia nigra, pars reticulata (SNR). Intranigral injections of GABA or dynorphin A inhibited, while intranigral injections of substance P or neurokinin A stimulated dopamine levels in the ipsilateral striatum. In rats with ibotenic acid lesions (2.5 g/0.5 l) in the SNR, intranigral injections of GABA or dynorphin A inhibited, while intranigral injections of substance P or neurokinin A stimulated dopamine levels in the ipsilateral striatum. These responses were not significantly different than those in unlesioned rats. Analysis of the intranigral lesion with in situ hybridization revealed a heavy loss of glutamic acid decarboxylase mRNA expression in the SNR and a significant loss of tyrosine hydroxylase (TH) mRNA expression in the SNC. Immunohistochemical analysis revealed a disappearance of TH-Like immunoreactivity (LI) im dendrites in the SNR, a considerable loss of TH-LI cell bodies in the SNC and a restricted loss of neuropeptide K-LI in the SNR around the tip of the injection cannula. Furthermore, lesioned rats rotated ipsilateral to the lesion after apomorphine (1 mg/kg, s.c.), indicating that the basal ganglia output mediated via the SNR GABA neurons was impaired on the lesioned side. Analysis of the striatum revealed that a dense TH-LI fiber network could still be seen on the lesioned side. Furthermore, basal and amphetamine stimulated extracellular dopamine levels in the striatum on the lesioned side were not significantly depleted. This indicates that the ascending nigrostriatal dopamine projection was functionally intact on the lesioned side. These findings indicate that intranigral GABA, dynorphin A, substance P and neurokinin A modulation of ipsilateral striatal dopamine release is mediated via direct action on the nigrostriatal projection. Thus, it is suggested that the striatonigral pathway, which contains GABA, dynorphin, substance P and neurokinin A, exerts a direct regulatory effect on the activity of the nigrostriatal dopamine projection.     

Which donor should be chosen for hematopoietic stem cell transplantation among unrelated HLA-A, -B, and -DRB1 genomically identical volunteers?

The aim of this study was to identify significant prognostic factors by using unrelated genomically HLA-A, -B and -DRB1-identical donors. Such data could help to choose the best donor. We studied 136 consecutive patients with hematologic malignancies and a median age of 32 years (range, 0-55 years) who received hematopoietic stem cell transplantation. Bone marrow grafts were given to 83 and peripheral blood stem cells to 53 patients. The cumulative incidence of grade II to IV acute graft-versus-host disease (GVHD) was 30% and of chronic GVHD was 54%. At 5 years, the overall transplant-related mortality (TRM) was 34%, and patient survival was 50%. In Cox multivariate analysis, 32 potential risk factors were analyzed. Monoclonal antibody OKT-3 during conditioning was correlated with grade II to IV acute GVHD, chronic GVHD, and TRM. HLA-DP mismatch was associated with poor TRM and poor survival. Cytomegalovirus-seropositive patients with a seronegative donor had a decreased leukemia-free survival. Five-year TRM was 14% with no risk factor, 38% with 1 risk factor, and 87% with 2 risk factors. The 5-year survival was 72%, 48%, and 30% with 0, 1, and 2 risk factors, respectively. We concluded that unrelated hematopoietic stem cell transplantation may be improved if an optimal donor and immunosuppression are chosen.     

Neuropeptide gene expression in brain is differentially regulated by midbrain dopamine neurons

Summary In situ hybridization was used to study the expression of prepro-neuropeptide Y (NPY), preprosomatostatin (SOM), preprotachykinin (PPT) and preprocholecystokinin (CCK) mRNA in caudate-putamen and frontoparietal cortex of rat brain with unilateral lesion of midbrain dopamine neurons. Neurons expressing NPY and SOM mRNA showed a similar distribution and the expression of both NPY and SOM appears to be regulated by dopamine in a similar fashion. Following a dopamine deafferentation, the numerical density of both NPY and SOM mRNA producing neurons almost doubled in the lesioned caudate-putamen with no change in the average grain density over positive neurons. Hence, in the intact caudate-putamen dopamine appears to suppress expression of these two neuropeptide genes leading to an activation of both NPY and SOM mRNA expression in many non- or low-expressing neurons when the level of dopamine is decreased. In the fronto-parietal cortex, on the other hand, dopamine appears to stimulate NPY and SOM gene expression. Thus, in the absence of dopamine about half of the NPY positive neurons disappeared. However, for SOM the number of positive neurons did not change, but rather most positive neurons appeared to have down-regulated their SOM mRNA expression. No evidence was found for a change in CCK mRNA expression by the dopamine deafferentation, while PPT mRNA expression decreased in the deafferented caudate-putamen. Consequently, dopamine exerts dissimilar effects on the expression of different neuropeptide genes, that in turn do not respond in the same way in different brain regions.     

Distribution of galanin-binding sites in the monkey and human telencephalon: preliminary observations

Summary Using X-ray film autoradiography the distribution of ¹²⁵I-galanin binding sites was studied in the forebrain of monkey and man. In the monkey a high density was found in all areas of the neocortex, especially layer 4, and in certain subfields in the hippocampal region. Also in the human brain high activity was seen in neocortex, mainly layer 6 and in hippocampal areas, as well as in amygdala, piriform cortex and hypothalamus. These results suggest that the 29-amino acid peptide galanin may be involved in the regulation of higher cortical functions in primates.     

Classical and chondroid chordoma. A light-microscopic, histochemical, ultrastructural and immunohistochemical analysis of the various cell types.

The aim of the present investigation was to characterize the various cell types of classical and chondroid chordomas. Eight cases of classical chordoma, 1 case of sacrococcygeal chordoma with chondroid areas and 2 cases of spheno-occipital chondroid chordoma were studied. Ultrastructurally and immunohistochemically (immunoreactivity for cytokeratins, epithelial membrane antigen [EMA], tissue polypeptide antigen [TPA] and human milk fat globule protein [HMFG]) the 3 cell types (physaliferous, epithelial-like, and spindle-shaped) recognized light-microscopically presented features of epithelial differentiation and rather formed a continuous spectrum than being distinct cell types. The chondroid areas of the chondroid chordomas had similar ultrastructural and immunohistochemical properties except for the lack of immunoreactivity for EMA and HMFG. The results of the critical electrolyte concentration technique according to Scott and Dorling indicated that there was no difference in the sulfated glycosaminoglycan content between classical and chondroid chordomas: all the tumors contained chondroitin sulfate. The presence of chondroitin sulfate, immunoreactivity for vimentin and S-100 protein and areas of cartilaginous differentiation in three cases indicate a relationship both to chondromatous tumors and to normal notochord, from which chordoma is believed to originate.     

Incidence of deep vein thrombosis in bedridden non-surgical patients

In order to detect deep vein thrombosis (DVT), 101 patients with acute medical or infectious disorders were examined with the 125I-fibrinogen uptake test. All patients were bedridden on admission and were scanned daily from the second to the eighth day. Thirteen patients developed a positive fibrinogen uptake test. Thus, if a positive test is interpreted as DVT, the incidence of DVT was 13% in our bedridden patients. Of the patients admitted because of heart disease or pneumonia 20% had DVT, but only 4% of those admitted with other diagnoses. Other clinical "risk factors" studied, could not identify patients who developed DVT.     

Leakage of macromolecules from guinea-pig tracheobronchial microcirculation. Effects of allergen, leukotrienes, tachykinins, and anti-asthma drugs

The tracheobronchial mucosa of anaesthetized guinea-pigs (normal or sensitized with ovalbumin to produce IgE and IgG antibodies) was superfused (0.02 ml min-1, 5 min) with saline, mediators, and (in sensitized animals) ovalbumin via a catheter atraumatically introduced orally. The intravascular blood pool and amount of macromolecules in excised trachea and adjoining main bronchi were quantified by measuring erythrocytes, that had been labelled in vivo with 99Tcm, and analysing for FITC-dextran, MW = 70,000, that had been given i.v. Extravasation of macromolecules was determined as the analysed total content minus the calculated intravascular content of FITC-dextran. Capsaicin 0.1 nmol extravasated 223 micrograms of FITC-dextran per g wet weight of airway tissue (P less than 0.001). Substance P 0.1 nmol, 41 micrograms g-1 (P greater than 0.05); substance P 0.3 nmol, 142 micrograms g-1 (P less than 0.001); eledoisine 0.1 nmol, 101 micrograms g-1 (P less than 0.01); ovalbumin 0.1 microgram, 179 micrograms g-1 (P less than 0.001); LTC4 0.2 pmol, 180 micrograms g-1 (P less than 0.001); LTD4 0.2 pmol 223 micrograms ml-1 (P less than 0.001). Bronchi and trachea were similarly affected by these agents. Prior superfusion (0.02 ml min-1, 30 min) with terbutaline 0.06 nmol, enprofylline 12 nmol, or lidocaine 6 nmol significantly reduced the effect of capsaicin. Enprofylline also reduced significantly the effect of LTC4. The degree of extravasation in this study was smaller than could be detected by changes in tissue wet to dry weight ratios. The present data support the view that tracheobronchial vascular permeability to macromolecules is subject to physiological and pharmacological control.     

Mouse homologues of the human AZF candidate gene RBM are expressed in spermatogonia and spermatids, and map to a Y chromosome deletion interval associated with a high incidence of sperm abnormalities

An RNA-binding motif (RBM) gene family has been identified on the human Y chromosome that maps to the same deletion interval as the 'azoospermia factor' (AZF). We have identified the homologous gene family (Rbm) on the mouse Y with a view to investigating the proposal that this gene family plays a role in spermatogenesis. At least 25 and probably >50 copies of Rbm are present on the mouse Y chromosome short arm located between Sry and the centromere. As in the human, a role in spermatogenesis is indicated by a germ cell-specific pattern of expression in the testis, but there are distinct differences in the pattern of expression between the two species. Mice carrying the deletion Yd1, that maps to the proximal Y short arm, are female due to a position effect resulting in non-expression of Sry ; sex-reversing such mice with an Sry transgene produces males with a high incidence of abnormal sperm, making this the third deletion interval on the mouse Y that affects some aspect of spermatogenesis. Most of the copies of Rbm map to this deletion interval, and the Yd1males have markedly reduced Rbm expression, suggesting that RBM deficiency may be responsible for, or contribute to, the abnormal sperm development. In man, deletion of the functional copies of RBM is associated with meiotic arrest rather than sperm anomalies; however, the different effects of deletion are consistent with the differences in expression between the two species.      

A Primary Male Autosomal Linkage Map of the Horse Genome

A primary male autosomal linkage map of the domestic horse (Equus caballus) has been developed by segregation analysis of 140 genetic markers within eight half-sib families. The family material comprised four Standardbred trotters and four Icelandic horses, with a total of 263 offspring. The marker set included 121 microsatellite markers, eight protein polymorphisms, five RFLPs, three blood group polymorphisms, two PCR–RFLPs, and one single strand conformation polymorphism (SSCP). One hundred markers were arranged into 25 linkage groups, 22 of which could be assigned physically to 18 different chromosomes (ECA1, ECA2, ECA3, ECA4, ECA5, ECA6, ECA7, ECA9, ECA10, ECA11, ECA13, ECA15, ECA16, ECA18, ECA19, ECA21, ECA22, and ECA30). The average distance between linked markers was 12.6 cM and the longest linkage group measured 103 cM. The total map distance contained within linkage groups was 679 cM. If the distances covered outside the ends of linkage groups and by unlinked markers were included, it was estimated that the marker set covered at least 1500 cM, that is, at least 50% of the genome. A comparison of the relationship between genetic and physical distances in anchored linkage groups gave ratios of 0.5–0.8 cM per Mb of DNA. This would suggest that the total male recombinational distance in the horse is 2000 cM; this value is lower than that suggested by chiasma counts. The present map should provide an important framework for future genome mapping in the horse.     

Increased levels of interferon-gamma (IFN-gamma), IL-4 and transforming growth factor-beta (TGF-beta) mRNA expressing blood mononuclear cells in human HIV infection.

Evidence has been presented for the involvement of IFN-gamma, IL-4 and TGF-beta in AIDS. Measured plasma levels may, however, poorly reflect in vivo production, since cytokines act auto- and paracrinally and have very short half life in plasma. In situ hybridization with complementary DNA oligonucleotide probes was used to enumerate blood mononuclear cells expressing cytokine messenger RNA (mRNA). HIV-infected patients had elevated blood levels of cells expressing each of the cytokines, with predominance for cells expressing TGF-beta mRNA. All AIDS patients included had elevated numbers of IL-4 mRNA-expressing cells, and levels of cells expressing this cytokine correlated inversely with counts of CD4+ cells in blood, reflecting the involvement of Th2-like cells in later stages of HIV infection. The described approach should be useful in further studies of cytokines in HIV infection and other diseases.