Nucleotide sequence of the pyruvate decarboxylase gene from Zymomonas mobilis.

Pyruvate decarboxylase (EC 4.1.1.1), the penultimate enzyme in the alcoholic fermentation pathway of Zymomonas mobilis, converts pyruvate to acetaldehyde and carbon dioxide. The complete nucleotide sequence of the structural gene encoding pyruvate decarboxylase from Zymomonas mobilis has been determined. The coding region is 1704 nucleotides long and encodes a polypeptide of 567 amino acids with a calculated subunit mass of 60,790 daltons. The amino acid sequence was confirmed by comparison with the amino acid sequence of a selection of tryptic fragments of the enzyme. The amino acid composition obtained from the nucleotide sequence is in good agreement with that obtained experimentally.     

Immunological Identification of Multiple α-Like Subunits of the γ-Aminobutyric AcidA Receptor Complex Purified from Neonatal Rat Cortex

Antibodies were prepared against a synthetic peptide corresponding to amino acid sequences 174-203 of the bovine gamma-aminobutyric acidA (GABAA) receptor alpha 1-subunit. The antibodies recognized this synthetic alpha 1-peptide, but failed to react with the homologous peptide sequence, 170-199, of the bovine beta 1-subunit. On Western blots, anti-alpha 1-subunit antibody recognized a 50-kilodalton (kDa) protein in affinity-purified receptor preparations from adult rat cortex and cerebellum. In receptor purified from neonatal cortex, the anti-alpha 1-antibody reacted with 50-kDa, 53-54-kDa, and 59-kDa proteins. After digestion with endoglycosidase F, these three protein bands retained differing electrophoretic mobilities. The 50-kDa and 59-kDa subunits of affinity-purified neonatal receptor, which were photoaffinity-labeled with [3H]flunitrazepam, were immunoprecipitated to different extents by alpha-subunit antibody. These data suggest the existence in GABAA receptor from neonatal cortex of three proteins (50 kDa, 53 kDa, and 59 kDa) which have immunological homology to alpha 1-subunit of bovine GABAA receptor. The presence of an alpha- and a beta-like subunit with similar mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis may account for the relatively high concentration of protein in the 53-54-kDa band which has been observed in receptor purified from neonatal cortex. The presence of multiple alpha-like subunits may be related to the presence of a relatively high concentration of type II GABA receptor in this tissue.     

Lucky rugose corals on crinoid stems: unusual examples of subepidermal epizoans from the Devonian of Morocco

Berkowski, B & Klug, C. 2011: Lucky rugose corals on crinoid stems: unusual examples of subepidermal epizoans from the Devonian of Morocco. Lethaia, Vol. 45, pp. 24–33. In the fossil record, evidence for true epizoans, i.e. living animals inhabiting other living host‐animals, is rather rare. A host reaction is usually needed to proof the syn vivo‐settling of the epizoan. Herein, we provide a first report of such an epizoan biocoenosis from various strata of the Early Devonian of Hamar Laghdad, the world‐renowned Moroccan mud‐mound locality. In this case, solitary rugose corals settled as larvae on crinoid stems, perhaps at a spot where the epidermis was missing for some reason (injury, disease). Both the crinoid and the coral began to grow around each other. By doing so, the affected crinoid columnals formed a swelling, where ultimately only an opening slightly larger than the coral orifice remained. We discuss both macroecological and small‐scale synecological aspects of this biocoenosis. The coral profited from its elevated home because it reached into more rapid currents providing the polyp with more food than at the densely populated seafloor, which was probably covered by a coral‐meadow around the mounds and hydrothermal vents. □Corals, crinoids, Early Devonian, epizoans, Morocco, Rugosa.     

Two forms of the GABAA receptor distinguished by anion-exchange chromatography

The GABAA receptor complex was solubilized from rat brain membranes in Triton X-100, enriched by 1012-S affinity chromatography, and subjected to DEAE anion-exchange chromatography. Two forms were distinguished by their differential elution during this HPLC with a KCl gradient. They displayed similar [3H]muscimol- and [3H]flunitrazepam-binding characteristics, as well as [3H]flunitrazepam-binding inhibition by CL 218872. Rechromatography of these distinct ionic forms indicated that they were not in dynamic equilibrium during chromatography. Resolution of these two pharmacologically similar populations of GABAA receptor by anion-exchange HPLC suggests that they differ in charge densities, a condition which may reflect differing glycosylation or phosphorylation states of the complex.     

Breast reconstruction in the burned adolescent female (an 11-year, 157 patient experience)

The experience accumulated after reconstruction of 157 burned breast patients has led to the development of surgical principles and techniques tailored to this problem. Most important among these principles is that the surgeon recognize and preserve viable breast bud tissue in the debridement phase of the acute burn. Reconstruction should begin when the burned breast envelope is insufficient and restricts normal growth. Best results are obtained if contracture release is complete, if defects are covered by thick split-thickness skin grafts, and if nipple-areola reconstruction is obtained from a normal opposite breast if present. Postoperative management should continue until wounds are mature and should include techniques to prevent contracture recurrence.     

Meta-analysis of the literature on diagnostic accuracy of SPECT in parkinsonian syndromes

Background  

Parkinson's disease (PD) is the second most common neurodegenerative disorder. One of the most widely used techniques to diagnose PD is a Single Photon Emission Computer Tomography (SPECT) scan to visualise the integrity of the dopaminergic pathways in the brain. Despite this there remains some discussion on the value of SPECT in the differential diagnosis of PD. We did a meta-analysis of all the existing literature on the diagnostic accuracy of both pre- and post-synaptic SPECT imaging in the differential diagnosis of PD.     

Nuclear-localized CTP:phosphocholine cytidylyltransferase α regulates phosphatidylcholine synthesis required for lipid droplet biogenesis

The reversible association of CTP:phosphocholine cytidylyltransferase α (CCTα) with membranes regulates the synthesis of phosphatidylcholine (PC) by the CDP-choline (Kennedy) pathway. Based on results with insect CCT homologues, translocation of nuclear CCTα onto cytoplasmic lipid droplets (LDs) is proposed to stimulate the synthesis of PC that is required for LD biogenesis and triacylglycerol (TAG) storage. We examined whether this regulatory mechanism applied to LD biogenesis in mammalian cells. During 3T3-L1 and human preadipocyte differentiation, CCTα expression and PC synthesis was induced. In 3T3-L1 cells, CCTα translocated from the nucleoplasm to the nuclear envelope and cytosol but did not associate with LDs. The enzyme also remained in the nucleus during human adipocyte differentiation. RNAi silencing in 3T3-L1 cells showed that CCTα regulated LD size but did not affect TAG storage or adipogenesis. LD biogenesis in nonadipocyte cell lines treated with oleate also promoted CCTα translocation to the nuclear envelope and/or cytoplasm but not LDs. In rat intestinal epithelial cells, CCTα silencing increased LD size, but LD number and TAG deposition were decreased due to oleate-induced cytotoxicity. We conclude that CCTα increases PC synthesis for LD biogenesis by translocation to the nuclear envelope and not cytoplasmic LDs.