Subcellular distribution of the enzymes of the malate-aspartate shuttle in rat heart and effect of experimental cardiac hypertrophy

The effect of experimental cardiac hypertrophy on the enzymes of the malate - aspartate shuttle aspartate aminotransferase (AAT) and malate dehydrogenase (MDH) was studied. ( l ) Aortic constriction in adult rats resulted in 25% cardiac hypertrophy in 2 1/2-3 weeks. Total DNA (mg per heart) did not change. ( 2 ) The proportions of mitochondrial and cytosolic isozymes of AAT and MDH did not change as a result of cardiac h y p e r t r o p h y . About two-thirds of each enzyme occurred in the mitochondrial form and one-third in the cytosolic form. ( 3 ) Total AAT in hypertrophic hearts, in enzyme units per mg DNA, increased by 24% compared to AAT content in the hearts of sham-operated animals . Total MDH did not change. SoIubilized protein increased by 20%. Normal hearts contained 10 times more enzyme units of MDH than of AAT. (4) Cardiac growth stimulation induced in newborn rats did not result in specific changes of either enzyme. It is suggested that true cardiac hypertrophy acts as a specific stimulus for the possibly rate-limiting enzyme AAT of the shuttle.     

MORPHOLOGY AND LABORATORY CULTIVATION OF ECHINOSTELIUM MINUTUM

Alexopoulos , Constantine J. (State U. Iowa, Iowa City.) Morphology and laboratory cultivation of Echinostelium minutum. Amer. Jour. Bot. 47(1): 37—43. Illus. 1960.—The morphology of the sporangium, spores, swarm cells and Plasmodium of the white form of Echinostelium minutum is described. A peridium is present in the early stages of sporangial formation. It eventually disappears leaving only a small collar at the base of the columella. The structure of the spore wall is unique in this genus. The spore case may be described as consisting of a thin wall with several thickened portions distributed over its surface. These are particularly evident in germinated spores. Spore germination and swarm cells are described for the first time. Swarm cells are biflagellate with two long anterior flagella of nearly equal length. The Plasmodium remains microscopic until fruiting time, when it gives rise to but a single sporangium. The plasmodial protoplast never becomes differentiated into veins but remains more or less homogeneous. It exhibits almost imperceptibly slow, irregular streaming instead of the reversible, rapid, rhythmic motion characteristic of plasmodia of most other Myxomycetes which have been studied. It typifies, therefore, a third type of Plasmodium which may be placed alongside that of the Physarales, and that of Stemonitis flavogenita. The laboratory cultivation of E. minutum from spore to spore on agar media is reported here for the first time.     

THE LABORATORY CULTIVATION OF STEMONITIS

Alexopoulos , Constantine J. (State U. Iowa, Iowa City.) The laboratory cultivation of Stemonitis. Amer. Jour. Bot. 46(2): 140-142. Illus. 1959.—The cultivation of a species of Stemonitis, probably S. flavogenita, in laboratory culture is reported here for the first time. The organism completed its entire life cycle on artificial media from spore to spore, in the presence of contaminating bacteria, in 36 days. The plasmodium, characteristically different from those of the Physarales, is described and illustrated.     

A highly sensitive molecular structural probe applied to in situ biosensing of metabolites using PEDOT:PSS

A large amount of research within organic biosensors is dominated by organic electrochemical transistors (OECTs) that use conducting polymers such as poly(3,4-ethylene dioxythiophene) doped with poly(styrenesulfonate) (PEDOT:PSS). Despite the recent advances in OECT-based biosensors, the sensing is solely reliant on the amperometric detection of the bioanalytes. This is typically accompanied by large undesirable parasitic electrical signals from the electroactive components in the electrolyte. Herein, we present the use of in situ resonance Raman spectroscopy to probe subtle molecular structural changes of PEDOT:PSS associated with its doping level. We demonstrate how such doping level changes of PEDOT:PSS can be used, for the first time, on operational OECTs for sensitive and selective metabolite sensing while simultaneously performing amperometric detection of the analyte. We test the sensitivity by molecularly sensing a lowest glucose concentration of 0.02 mM in phosphate-buffered saline solution. By changing the electrolyte to cell culture media, the selectivity of in situ resonance Raman spectroscopy is emphasized as it remains unaffected by other electroactive components in the electrolyte. The application of this molecular structural probe highlights the importance of developing biosensing probes that benefit from high sensitivity of the material's structural and electrical properties while being complimentary with the electronic methods of detection.     

Conformational study of new amphipathic alpha-helical peptide models of apoA-I as potential atheroprotective agents

Aiming at contributing to the development of potential atheroprotective agents, we report on the concept and design of two peptide models, which mimic the amphipathic helices of apoA-I and incorporate Met into their sequences to validate its role as oxidant scavenger: Ac-ESK(Palm)KELSKSW(10)SEM(13)LKEK(Palm)SKS-NH(2) (model 1 [W(10), M(13)]) and Ac-ESK(Palm)KELSKSM(10)SEW(13)LKEK(Palm)SKS-NH(2) (model 2 [M(10), W(13)]). Hydrophobic residues of both models cover about the half of the surface, while the positively and negatively charged residues constitute two separate clusters on the hydrophilic face. Palmitoyl groups were introduced into the Lys-N(epsilon)H(2) groups at positions 3 and 17 to contribute to the amphipathic character of the peptides and stabilize the nonpolar face of the helix. Conformational study by the combined application of 2D-NMR and molecular dynamics simulations, CD, FTIR, and fluorescence spectroscopy revealed that model 1 adopts helical conformation and Met is well exposed to the microenvironment. Model 2 that derives from model 1 by exchanging W(10) (model 1) with M(10) and M(13) (model 1) with W(13) also displays helical characteristics, while Met is rather shielded. Oxidation experiments indicated that model 1 exhibits a 2-fold more potent antioxidant activity towards LDL oxidation, compared to model 2, confirming the role of Met, when is devoid of steric hindrances, as oxidant scavenger for the protection of LDL.     

Rapid growth and elongation of bovine blastocysts in vitro in a three-dimensional gel system

The aim of this study was to establish an in vitro system that supports development and differentiation of bovine blastocysts. Agar gel tunnels were covered with modified synthetic oviduct fluid medium supplemented with 10% fetal calf serum and 3g/l D-glucose. Of the total 67 blastocysts loaded individually into the tunnels, 46 continued expansion to 1mm and reached the walls of the gel on Day 10. On Day 12, 35 blastocysts elongated to minimum 1.6 mm while filling completely the space between the walls of the tunnel, and 16 still continued growth and reached an average of 4.3 mm length on Day 14. The largest blastocyst on Day 16 was 12 mm long. On Day 12, in 31 of the 35 elongated blastocysts a second cell layer occurred beneath the trophoblast and formed a complete cover in surviving Day 14 embryos. In most proliferating embryos the inner cell mass was prominent, however, the detection of signs of embryonic disc formation will require further studies. The established system was suitable to induce in vitro elongation, rapid growth and further differentiation, and may have considerable theoretical and practical value for studies of development and differentiation of bovine embryos.     

Association of Fusarium mycotoxicosis with failure in applying an induction of parturition program with PGF2alpha and oxytocin in sows

This trial was conducted in a farrow-to-finish pig unit from November 1999 to February 2000. Since November 1998 an induction-of-parturition program was applied in gilts and sows with PGF2alpha (2 mL Dinolytic, i.m.) 113 d post service, followed by oxytocin (1 mL Intertocine-S, i.m.) 24 h later. This program resulted in a high proportion of animals farrowing within the working hours of the day. At mid December 1999 splay-legs and edematous swelling and reddening of the vulva started to be observed in newborn piglets. A concurrent decline of parameters related to parturition also was noticed. Mycotoxicological analyses of the feeds revealed a co-occurring contamination with deoxynivalenol and zearalenone. For a 4-week period, sows were divided into two groups: (a) an induction-of-parturition and (b) a non-induction-of-parturition group. Significant differences were found between the two groups relating to prevalence of dystocia (<.05) and pregnancy duration (<.05). Moreover, it was found that prevalence of splay-legs and swelling of the vulva were highly correlated (<.05) with reduction of percentage of sows farrowing within the working day and increase of pre-weaning mortality. It was concluded that such an induction-of-parturition program should be avoided during a Fusarium mycotoxicosis.     

The position of the LysN epsilon H2-grafted antigens along the sequential oligopeptide carrier, Ac-(Aib-Lys-Aib-Gly)n (SOCn-II), influences the antibody recognition: application to the Sm main autoimmune epitope

A sequential oligopeptide carrier of antigenic peptides is presented, incorporating two Aib residues in each repetitive moiety: Ac-(Aib-Lys-Aib-Gly)(n) (SOC(n) -II; n = 2-4). The conformational study, by (1)H-nmr, CD, and Fourier transform ir spectroscopy, indicated that the SOC(n) -II carrier displays a pronounced 3(10)-helix, compared to the Ac-(Lys-Aib-Gly)(n) (SOC(n) -I) carrier of the same approximately backbone length, previously reported. One of the dominant autoimmune epitopes of the Sm and U1RNP cellular components, the PPGMRPP sequence, was coupled to the Lys-N(epsilon)H(2) groups of the SOC(n) -II carrier and used as antigenic substrate for detecting anti-Sm/U1RNP autoantibodies in ELISA assays. Anti-Sm antibodies are highly specific for systemic lupus erythematosus, while anti-U1RNP are specific for mixed connective tissue disease. The anti-(PPGMRPP)(5)-SOC(n) -II ELISA was compared with the anti-(PPGMRPP)(n) -SOC(n) -I ELISA, provided that both antigenic substrates possess the same amount of the epitope replicates. The significance of the lysine positions along the oligopeptide backbone of the carrier for a favorable antibody recognition of the anchored antigens is also examined.     

Genetic skeletal disorders of the fetus and infant: Pathologic and molecular findings in a series of 41 cases

BACKGROUND: Genetic skeletal disorders of the fetus and infant are a large group of genetic disorders, comprising the groups formerly assigned as skeletal dysplasias (osteochondrodysplasias), dysostoses, and malformation syndromes with a skeletal component. Genetic skeletal disorders may be prenatally detected by ultrasonography or result in intrauterine or early postnatal death, constituting one difficult diagnostic field met by the pathologist who performs the perinatal autopsy. METHODS: In this retrospective study, we have gathered radiologic, physical, histopathologic, and molecular data regarding 41 cases of genetic skeletal disorders diagnosed among 1980 fetal and perinatal autopsies over a 10‐year period. RESULTS: Our series of cases were classified according to the 2006 Nosology and Classification of Genetic Skeletal Disorders. The overall frequency of genetic skeletal disorders was 1:48 autopsies. The FGFR3 group and osteogenesis imperfecta type 2 were the more frequently encountered disorders. The mean gestational age at autopsy was 21.9 weeks (range, 12–37 weeks). A final diagnosis was obtained in 95% of cases. Genetic skeletal disorders were detected by prenatal ultrasound in 90% of cases, with a correct typing of the disorder achieved in only 34%. Molecular analysis was confirmative in 5 cases. CONCLUSIONS: The central role of the perinatal pathologist in collaboration with specialized services is essential for the correct interpretation of the radiologic, physical, and histopathologic findings, to accurately classify specific types of genetic skeletal disorders and enable genetic counseling. Birth Defects Research (Part A), 2009. © 2009 Wiley‐Liss, Inc.