Fatal perinatal sarcocystosis in a lamb

A 3-wk-old lamb died because of neurological disease. The predominant microscopic lesions were in the brain and spinal cord and consisted of nonsuppurative encephalomyelitis with severe gliosis throughout the gray and white matter. Immature and mature schizonts, 15.7 x 10.6 microns (8-30 x 6-18 microns), occurred in capillaries and were structurally similar to those of Sarcocystis tenella.     

RAB-6.1 and RAB-6.2 Promote Retrograde Transport in C. elegans

Retrograde transport is a critical mechanism for recycling certain membrane cargo. Following endocytosis from the plasma membrane, retrograde cargo is moved from early endosomes to Golgi followed by transport (recycling) back to the plasma membrane. The complete molecular and cellular mechanisms of retrograde transport remain unclear. The small GTPase RAB-6.2 mediates the retrograde recycling of the AMPA-type glutamate receptor (AMPAR) subunit GLR-1 in C. elegans neurons. Here we show that RAB-6.2 and a close paralog, RAB-6.1, together regulate retrograde transport in both neurons and non-neuronal tissue. Mutants for rab-6.1 or rab-6.2 fail to recycle GLR-1 receptors, resulting in GLR-1 turnover and behavioral defects indicative of diminished GLR-1 function. Loss of both rab-6.1 and rab-6.2 results in an additive effect on GLR-1 retrograde recycling, indicating that these two C. elegans Rab6 isoforms have overlapping functions. MIG-14 (Wntless) protein, which undergoes retrograde recycling, undergoes a similar degradation in intestinal epithelia in both rab-6.1 and rab-6.2 mutants, suggesting a broader role for these proteins in retrograde transport. Surprisingly, MIG-14 is localized to separate, spatially segregated endosomal compartments in rab-6.1 mutants compared to rab-6.2 mutants. Our results indicate that RAB-6.1 and RAB-6.2 have partially redundant functions in overall retrograde transport, but also have their own unique cellular- and subcellular functions.     

The ossification centers in the lower end of tibiotarsus in domestic fowl.

The morphogenesis of lower end of tibia in chick is studied commonly but the process of ossification of the same has received very little attention so far. The present study is directed to throw some light on the appearance of ossification centers in the lower end of tibiotarsus of chick. The histology of lower end of tibiotarsus was studied by procuring developing tibiotarsi from chick embryos (20) of 6th day incubation till hatching and 3 post hatched chicks. The transparancies of chick embryos at different incubation periods and post hatched chicks were prepared by Dawson's Alizarin staining method. Three cartilage center (tibial, fibulare and intermedium) appeared in 6...9 days of incubation period in the tarsal region. These gradually fused with the lower end of tibia. Three ossification centres developed in the lower end of tibiotarsus. One for intermedium appeared on 16th day and two fotibial and fibulare on 20th day. All these three centres could be located in the transparancies of the chick embryos in tarsal region. The present study proves that the three cartilages centres maintain their individuality during the ossification process even though those fuse completely with the lower end of tibia in chick. The centers for tibial and fibulare are similar to epiphyseal centres of mammals in histological details.     

Induced Mutation inPetunia nyctaginiflora JUSS.

Seeds ofPetunia nyctaginifloraJuss. a common ornamental garden plant, were treated with two alkylating agents (methyl methane sulphonate and N-methyl-N’-nitro-N-nitrosoguanidine). Six morphological and seven chlorophyll mutants were isolated from M₂ segregating families. The isolated induced mutants are described and genetically analysed.     

Toxicity of chromium and tin toAnabaena doliolum Interaction with bivalent cations

Summary The toxicity of chromium and tin on growth, photosynthetic carbon-fixation, oxygen evolution, heterocyst differentiation and nitrogenase activity ofAnabaena doliolum and its interaction with bivalent cations has been studied. Some interacting cations, viz. Ca²⁺, Mg²⁺ and Mn²⁺, substantially antagonised the toxic effects of chromium and tin with reference to growth, heterocyst differentiation and nitrogenase activity in the following hierarchal sequence: Ca²⁺ > Mg²⁺ > Mn²⁺. However, the sequence of hierarchy was Mg²⁺ > Ca²⁺ > Mn²⁺ for carbon fixation and Mn²⁺ > Mg²⁺ > Ca²⁺ for photosynthetic oxygen evolution. Synergistically inhibitory patterns were noticed for all the parameters, viz. growth,¹⁴CO₂ uptake, oxygen evolution, heterocyst differentiation and nitrogenase activity ofA. doliolum when Ni²⁺, Co²⁺ and Zn²⁺ were combined with the test metals in the growth medium. These cations followed the following sequence of synergistic inhibition: Ni²⁺ > Co²⁺ > Zn²⁺. Among all the interacting cations, Ca²⁺, Mg²⁺ and Mn²⁺ exhibited antagonistic effects which relieved the test cyanobacterium from metal toxicity. In contrast to this, Ni²⁺, CO²⁺ and Zn²⁺ showed synergistic inhibition which potentiating the toxicity of test metals in the N₂-fixing cyanobacteriumA. doliolum. It is evident from the present study that bivalent cations, viz. Ca²⁺, Mg²⁺, Mn²⁺, Ni²⁺, Co²⁺ and Zn²⁺, may appreciably regulate the toxicity of heavy metals in N₂-fixing cyanobacteria if present in aquatic media.     

Experimental Sarcocystis hominis infection in cattle: lesions and ultrastructure of sarcocysts

Five calves inoculated orally with 10(5)-10(6) sporocysts of Sarcocystis hominis from human feces were necropsied 10, 18, 24, 111, and 222 days postinoculation (DPI). Calves became febrile (greater than 40-41 C) between 10 and 24 DPI and developed mild anemia (packed cell volumes were reduced by 40% of initial values) between 29 and 57 DPI but otherwise remained clinically normal. Focal hepatitis, mesenteric lymphadenitis, and myocarditis were seen in calves at 10, 18, and 24 DPI. No stages of the parasite were found at any of these times except for a few merozoites in macrophages associated with myocardial lesions in the calf necropsied 24 DPI. Mature sarcocysts at 111 and 222 DPI were up to 950 microm long and their walls were up to 6 microm thick. They were found only in skeletal muscles. One immature sarcocyst was seen in the myocardium of the calf at 222 DPI.     

An unusual structure in the primary cyst wall of Sarcocystis hemionilatrantis

Disc-shaped plaques were found in the primary cyst wall of sarcocysts of Sarcocystis hemionilatrantis in mule deer in Montana. Ultrastructurally, the plaques were 190.5 nm in diameter, 161.6 nm thick and consisted of six distinct layers with microfilaments arising from the innermost layer. These unusual plaques have not been reported previously for any species of Sarcocystis.     

Synthesis of 2-acetamido-2-deoxy-4-O-β-d-galactopyranosyl-3-O-methyl-d-glucopyranose (N-acetyl-3-O-methyllactosamine) and its benzyl α-glycoside

Benzyl 2-acetamido-2-deoxy-3-O-methyl-α-d-glucopyranoside (3) was obtained by deacetalation of its 4,6-O-benzylidene derivative (2). Compound 2 was prepared by methylation of benzyl 2-acetamido-4,6-O-benzylidene-2-deoxy-α-d-glucopyranoside with methyl iodide-silver oxide in N,N-dimethylformamide. Diol 3 was selectively benzoylated and p-toluenesulfonylated, to give the 6-benzoic and 6-p-toluenesulfonic esters (4 and 5, respectively). Displacement of the sulfonyl group of 5 with sodium benzoxide in benzyl alcohol afforded the 6-O-benzyl derivative (6). Glycosylation of 4 with 2,3,4,6-tetra-O-acetyl-α-d-galactopyranosyl bromide (7) in dichloromethane, in the presence of 1,1,3,3-tetramethylurea, furnished the disaccharide derivative 8. Similar glycosylation of compound 6 with bromide 7 gave the disaccharide derivative 10. O-Deacetylation of 8 and 10 afforded disaccharides 9 and 11. The structure of compound 9 was established by ¹³C-n.m.r. spectroscopy. Hydrogenolysis of the benzyl groups of 11 furnished the disaccharide 2-acetamido-2-deoxy-4-O-β-d-galactopyranosyl-3-O-methyl-d-glucopyranose (N-acetyl-3-O-methyllactosamine).     

Application of new catalytic phosphate protecting groups for the highly efficient phosphotriester oligonucleotide synthesis.

An effective procedure for the synthesis of oligonucleotides by the phosphotriester method has been developed. The procedure is based on the use of phosphate protecting groups enabling O-nucleophilic intramolecular catalysis in the reaction of internucleotide bond formation under the action of arylsulfonyl chlorides and their derivatives. Using this new procedure, the time needed to perform one elongation step on polymer support is 7-8 min. The effectiveness of the methodology has been demonstrated in the synthesis of many oligodeoxyribonucleotides of different length with high yields.