Mx proteins: GTPases with antiviral activity

Mx proteins are synthesized in interferon-treated vertebrate cells. They have attracted much attention because some of them can block the multiplication of influenza A virus and certain other negative-stranded RNA viruses. Recently, Mx proteins have been shown to be GTPases with significant homology to dynamins and yeast VPS1, enzymes involved in intracellular protein trafficking. Several biochemical properties of dynamin and VPS1 are similar to those of Mx, promoting new speculation about how Mx proteins might interfere with virus multiplication.     

Quantitative changes in the expression of histone H1 and H2B subtypes and their relationship to the differentiation of mouse embryonal carcinoma cells

The pattern of histones from several mouse embryonal carcinoma cell (ECC) lines, differentiated cell lines, and adult organs was analyzed using acid-urea gels containing Triton X-100 and long SDS-gel electrophoresis. All cell lines had comparable histone types except for a unique H2B-like component that was found only in the ECC line PCC4. The mouse histone H1 has four different subtypes (H1a, H1b, H1c, and H1d), as resolved in SDS-gel electrophoresis. The expression of the four subtypes was shown to be cell line specific. Subtypes H1a and H1d are present in approximately the same relative amounts in all cell lines investigated. Subtype H1b is found in higher relative amounts than subtype H1c in ECC lines and testis. The ratio of H1b and H1c is reversed in differentiated cell lines and in kidney, white blood cells, liver and spleen. All four subtypes of H1 are phosphorylated although to a different extent in different cell lines. In ECC lines, subtypes H1b and especially H1d incorporate most of a ³²P label, whereas H1c is predominately phosphorylated in differentiated parietal endoderm cell lines. These data indicate that H1 subtypes differ depending on the stage of cell differentiation. Difference in ratio between H1 subtypes and in phosphorylation might influence the chromatin configuration and thus gene expression in these cells.     

Teratocarcinoma antigen is secreted by epididymal cells and coupled to maturing sperm

Teratocarcinoma specified antigen SSEA-1, is present on ejaculated sperm, but it is not evident on testicular sperm. We show that SSEA-1 is secreted by the chief cells of the caput epididymis and is then adsorbed to the surface of the spermatozoa during their passage through the epididymis.     

Virus-Eiweißspindeln der Kakteen in Lokalläsionen vonChenopodium

Zusammenfassung Das Virus, das beiZygocactus, Opuntia und vielen anderen Kakteen die Entstehung von Eiweißspindeln veranlaßt, wurde mechanisch aufChenopodium amaranticolor undChenopodium album übertragen. Unter dem Einfluß dieses Virus erscheinen an den Blättern dieser Pflanzen 20 bis 45 Tage nach Inokulation Lokalläsionen in Form von chlorotischen Flecken. Die Läsionen sind manchmal durch Anthozyan deutlich rot gefärbt und häufig von einem grünen Ring umgeben. Bei der mikroskopischen Durchsicht der inokulierten Blätter wurde festgestellt, daß sich nur im Bereiche der Lokalläsionen eine große Anzahl von Eiweißspindeln befindet.Außerdem wurden große X-Körper auch in den Lokalläsionen gefunden, die sich unter dem Einfluß des Tabakmosaikvirus an den Blättern vonChenopodium amaranticolor bildeten. Diese Einschlüsse befanden sich sehr reichlich in den roten Höfen, welche die nekrotische Zentren der Lokalläsionen umgaben.     

Ketamine does not affect intestinal microcirculation in pentobarbital-anaesthetized rats during experimental endotoxaemia

The objective of the study was to evaluate the effects of ketamine on intestinal microcirculation in pentobarbital-anaesthetized rats during experimental endotoxaemia. A prospective, randomized, controlled study was carried out using 32 male Lewis rats. The animals were divided into four groups (n = 8 each). All animals were initially anaesthetized with 60 mg/kg pentobarbital (i.p.). Group 1 served as a control (18.5 mg/kg/h pentobarbital i.v.). Groups 2 and 4 received an endotoxin intravenous infusion of 15 mg/kg lipopolysaccharide (LPS) from Escherichia coli. Groups 3 and 4 also received 10 mg/kg/h ketamine (i.v.). After 2 h of observation, the animals were examined for intestinal functional capillary density (FCD) and leukocyte adherence to the venular endothelium by means of intravital fluorescence microscopy (IVM). Subsequent to this examination, blood samples were collected to determine release of the cytokines tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6 and IL-10. Endotoxaemia tended to decrease intestinal FCD (mucosa: -10.1%, muscularis longitudinalis: -2%, muscularis circularis: -9.8%) and significantly increase leukocyte adherence within submucosal venules (collecting venules: +133%, postcapillary venules: +207%; P<0.05). TNF-alpha, IL-1beta, IL-6 and IL-10 levels were significantly elevated following endotoxin challenge. The addition of ketamine to pentobarbital anaesthesia did not significantly affect FCD, leukocyte behaviour or cytokine levels. In conclusion, intravenous pentobarbital anaesthesia with the additional administration of ketamine did not cause alterations within the microcirculation or changes in cytokine release during endotoxaemia. In rats, the combination of pentobarbital and ketamine is suitable for use during the study of intestinal microcirculation in experimental endotoxaemia.     

Characterization of lamin mutation phenotypes in Drosophila and comparison to human laminopathies

Lamins are intermediate filament proteins that make up the nuclear lamina, a matrix underlying the nuclear membrane in all metazoan cells that is important for nuclear form and function. Vertebrate A-type lamins are expressed in differentiating cells, while B-type lamins are expressed ubiquitously. Drosophila has two lamin genes that are expressed in A- and B-type patterns, and it is assumed that similarly expressed lamins perform similar functions. However, Drosophila and vertebrate lamins are not orthologous, and their expression patterns evolved independently. It is therefore of interest to examine the effects of mutations in lamin genes. Mutations in the mammalian lamin A/C gene cause a range of diseases, collectively called laminopathies, that include muscular dystrophies and premature aging disorders. We compared the sequences of lamin genes from different species, and we have characterized larval and adult phenotypes in Drosophila bearing mutations in the lam gene that is expressed in the B-type pattern. Larvae move less and show subtle muscle defects, and surviving lam adults are flightless and walk like aged wild-type flies, suggesting that lam phenotypes might result from neuromuscular defects, premature aging, or both. The resemblance of Drosophila lam phenotypes to human laminopathies suggests that some lamin functions may be performed by differently expressed genes in flies and mammals. Such still-unknown functions thus would not be dependent on lamin gene expression pattern, suggesting the presence of other lamin functions that are expression dependent. Our results illustrate a complex interplay between lamin gene expression and function through evolution.     

Deamination of 2',3'-O-isopropylideneadenosine-5'- carboxylic acid catalyzed by adenosine deaminase (ADA) and adenylate deaminase (AMPDA): influence of substrate ionization on the activity of the enzymes

Adenosine deaminase (ADA) and adenylate deaminase (AMPDA) catalyze the deamination of 2 ',3 '-O-isopropylideneadenosine-5'-carboxylic acid to the corresponding inosine derivative and dependence of the rate of enzymatic reaction on the ionization degree of the substrate has been studied at different pH values.     

Effect of monosodium glutamate on oxidative stress and apoptosis in rat thymus

It has been demonstrated that administration of high concentrations of monosodium glutamate (MSG), induce oxidative stress in different organs, but not in thymus. In the present study we examined the role of oxidative stress in MSG-induced thymocyte apoptosis. MSG was administrated intraperitoneally (4 mg/g of body weight) for six consecutive days. Animals were sacrificed at 1st, 7th, and 15th day after last MSG dose. MSG administration to animals significantly increased apoptotic rate of thymocytes (P < 0.01), together with significant increase of malondialdehyde (MDA) level (P < 0.001) and xanthine oxidase (XO) activity (P < 0.01), in time dependent manner. Catalase activity, during examination period, was significantly decreased (0 < 0.01). Obtained results showed that MSG treatment induced oxidative stress in thymus, which may have an important role in thymocyte apoptosis induced by MSG.     

Snodgrass' urethroplasty in hypospadias surgery in Clinical Hospital Mostar--preliminary report

Amongst the various methods of reconstructing the hypospadic urethra such as the MAGPI, Mathieu's and Preputial island flap urethroplasty method and the Snodgrass method, the latter is being used more frequently nowadays in patients with the urethral meatus located in the proximity of the penis. In the Pediatric ward at Mostar Clinical Hospital, we have recently adopted the Snodgrass method when reconstructing the hypospadic urethra. We herewith present our research regarding the successful results in adopting the aforementioned method. Success was evaluated according to the frequency of post-operative complications, as well as the patients' satisfaction with the functional and the cosmetic result of the urethra reconstruction. The conclusions relating to our research result in an addition basis from which to evaluate whether the Snodgrass method should receive privileged preference in future operative treatment of the hypospadias over others methods, as can be seen from our research.