Stimulation of myogenesis by 2,2'-thiodiethanol in suboptimal tissue culture conditions

It is shown that 2,2'-thiodiethanol, a product of yperite hydrolysis, strongly stimulates differentiation of chick embryo myogenic cells. In its presence myoblasts fused, yielding myotubes with the same efficiency in standard media for chick embryo fibroblast-like cell culture (containing 4% bovine serum and 1% chick serum) as in media specially designed to promote myoblast fusion (containing 10% horse serum and 5% chick serum). What is more, the myofibres formed in the presence of 0.1% 2,2'-thiodiethanol morphologically resembled more closely myofibres formed in vivo than those formed in the presence of horse serum.     

Activation of mitochondrial glycerol 3-phosphate dehydrogenase by cadmium ions

Mitochondrial glycerol 3-phosphate dehydrogenase (EC 1.1.2.1.) requires Ca2+ ions for its activity. Cadmium ions also have activatory effect on the enzyme. They activate the glycerol 3-phosphate dehydrogenase in a very narrow concentration range (1-2 mmol/l). As contrasted with calcium, strong inhibitory effect occurred at higher concentrations (3-4 mmol/l). The inhibition induced by cadmium ions was completely reversible by washing of the mitochondria.     

Architecture and anatomy of the chromosomal locus in human chromosome 21 encoding the Cu/Zn superoxide dismutase.

The SOD-1 gene on chromosome 21 and approximately 100 kb of chromosomal DNA from the 21q22 region have been isolated and characterized. The gene which is present as a single copy per haploid genome spans 11 kb of chromosomal DNA. Heteroduplex analysis and DNA sequencing reveals five rather small exons and four introns that interrupt the coding region. The donor sequence at the first intron contains an unusual variant dinucleotide 5'-G-C, rather than the highly conserved 5'-GT. The unusual splice junction is functional in vivo since it was detected in both alleles of the SOD-1 gene, which were defined by differences in the length of restriction endonuclease fragments (RFLPs) that hybridize to the cDNA probe. Genomic blots of human DNA isolated from cells trisomic for chromosome 21 (Down's syndrome patients) show the normal pattern of bands. At the 5' end of gene there are the 'TATA' and 'CAT' promoter sequences as well as four copies of the -GGCGGG- hexanucleotide. Two of these -GC- elements are contained within a 13 nucleotide inverted repeat that could form a stem-loop structure with stability of -33 kcal. The 3'-non coding region of the gene contains five short open reading-frames starting with ATG and terminating with stop codons.     

Sequence comparison of 'states' of a1-m1 suggests a model of Spm (En) action

Two states of the a1-m1 allele featuring different phenotypes in the absence as well as in the presence of Spm or En have been cloned and sequenced.. The insertion site and orientation of the Inhibitor (I) element within the two alleles is identical. The sizes of the I elements differ, being 2.2 kb in state 6078 and 789 bp in state 5719A-1. The internal deletion in state 5719A-1 affects sequences within one side of the terminal inverted repeats of the I element. This alteration can be correlated with the decreased response of this state to the Mutator function of Spm. A model for the interaction between Spm (En)-encoded functions and the receptor element is discussed explaining the phenotypic differences between the states of the locus.     

Plasma concentrations of arginine vasotocin, prolactin, aldosterone and corticosterone in relation to oviposition and dietary NaCl in the domestic fowl

The osmolality and concentrations of Na, K, Cl and the hormones arginine vasotocin (AVT), prolactin, aldosterone and corticosterone were measured in plasma as functions of time in relation to oviposition, changing NaCl content of the diet, and feeding-inanition. AVT was significantly increased immediately after oviposition (but not during the hour before) with a calculated average value of 38.0 +/- 4.1 pg/ml at oviposition. A moderate increase in concentrations of prolactin and corticosterone were observed immediately after oviposition. Oviposition was not associated with detectable changes in plasma osmolality (and electrolyte concentrations) nor with the concentration of aldosterone. After a sudden change from a high NaCl diet to a low NaCl diet the plasma osmolality and concentrations of NaCl, AVT and prolactin reached new stable levels in 24 hr, whereas the plasma aldosterone concentration required more than 4 days to reach a steady level. After resalination plasma aldosterone was suppressed in less than 8 hr. Both osmolality and concentrations of AVT and prolactin showed transient overshoots during the first 24 hr. NaCl depletion resulted in a transient increase of corticosterone.     

Crosslinking of chromosomal antigen common in human tumors to DNA by cis-diamminedichloroplatinum (II)

The antisera specific for dehistonized Hela cell chromatin were obtained by injecting rabbits or goats. Treatment of chromatin with cis-DDP crosslinked the active proteins to DNA thus preventing dissociation of the proteins in a high salt environment.Immunochemical staining of electrophoretically separated chromosomal proteins transferred to nitrocellulose sheets revealed that cis-DDP among others crosslinked the protein with m.w. of about 81 000. This protein is the only major protein antigen presented in several human tumors and absent in normal human tissues.     

Simultaneous ultrastructural demonstration of retrogradely transported horseradish peroxidase and choline acetyltransferase immunoreactivity

In order to study the synaptic connections of neurons identified by their projection target and neurotransmitter content, we have adapted a method of combining retrograde tracing of horseradish peroxidase (HRP) and immunocytochemistry at the electron microscopic level. HRP was injected into the rat amygdala. Sections from the rostral forebrain were processed according to the 3,3'-diaminobenzidine/glucose oxidase reaction followed by choline acetyltransferase (ChAT) localization. Neurons in the ventral pallidum which contained both the diffuse immunoperoxidase reaction product (ChAT) and large electron dense bodies characteristic of retrogradely transported HRP were defined as double labeled, i.e. cholinergic neurons that project to the amygdaloid body.     

The origin and ultrastructural characteristics of corticotropin-releasing factor (CRF)-immunoreactive nerve fibers in the posterior pituitary of the rat

Summary A fine network of corticotropin-releasing factor (CRF)-immunopositive fibers was found in the posterior lobe of the pituitary of the rat. The intermediate and distal lobes were free of CRF-immunoreactivity. Varicose, terminal-like axons were frequently observed around capillary vessels. Surgical isolation of the paraventricular nuclei resulted in a complete disappearance of CRF-immunoreactive fibers from the posterior lobe. CRF-immunopositive fibers show the general characteristics of peptidergic axons. These ultrastructural observations support the idea that CRF is secreted into capillary vessels.     

Blood supply of the bed nucleus of the stria terminalis in rat

Summary The topographical distribution of the blood vessels in the bed nucleus of the stria terminalis (NIST) has been mapped in rats. Arteries and veins were visualized in red and blue by using a double-ink perfusion technique. Arteries supplying the NIST arise from the anterior cerebral artery directly or through the anterior communicating and interhemispheric arteries. Only a few, dorsal branches derive from the medial cerebral artery through thalamostriatal arteries. According to their terminal branches, NIST arteries can be divided into five groups: medial, ventral, lateral, septal and dorsal, which have only a relatively small overlap in their territories. About 90% of veins from the NIST drain into the major basal veins. Medial branches run into the perioptic and interhemispheric veins, while the ventral branches and the large lateral vein drain directly into the anterior cerebral vein. A small proportion of NIST veins run dorsalward into the vena cerebri magna via thalamostriatal veins.     

Application of antigens from Taenia hydatigena cyst fluid for the immunodiagnosis of human hydatidosis

Fluid was collected from cysts of Taenia hydatigena in 60 adult sheep and fluid from each animal pooled separately. By double diffusion antigen 5 was demonstrated in all pools but one. The criteria are described for selection and standardization of these preparations for use as antigens for the immunodiagnosis of human hydatid disease. Sera from 50 persons harbouring hydatid cysts and from 50 patients with other disease conditions were examined by the arc-5 double-diffusion test, using two antigens prepared from Echinococcus granulosus and T. hydatigena cyst fluids, respectively. The results showed that a higher diagnostic sensitivity was obtained with the hydatid antigen. The significance of the findings is discussed in terms of their application to human immunodiagnosis in areas where hydatidosis, but not cysticercosis, is rare in livestock.