The Facioscapulohumeral muscular dystrophy region on 4qter and the homologous locus on 10qter evolved independently under different evolutionary pressure

Background  

The homologous 4q and 10q subtelomeric regions include two distinctive polymorphic arrays of 3.3 kb repeats, named D4Z4. An additional BlnI restriction site on the 10q-type sequence allows to distinguish the chromosomal origin of the repeats. Reduction in the number of D4Z4 repeats below a threshold of 10 at the 4q locus is tightly linked to Facioscapulohumeral Muscular Dystrophy (FSHD), while similar contractions at 10q locus, are not pathogenic. Sequence variations due to the presence of BlnI-sensitive repeats (10q-type) on chromosome 4 or viceversa of BlnI-resistant repeats (4q-type) on chromosome 10 are observed in both alleles.     

The role of auxiliary dihydropyridine receptor subunits in muscle

The skeletal muscle dihydropyridine receptor is a slowly-activating calcium channel that functions as the voltage sensor in excitation-contraction coupling. In addition to the pore-forming α_1S subunit it contains the transmembrane α₂δ-1 and γ₁ subunits and the cytoplasmic β_1a subunit. Although the roles of the auxiliary subunits in calcium channel function have been intensively studied in heterologous expression systems, their functions in excitation-contraction coupling has only recently been elucidated in muscle cells of various null-mutant animal models. In this article we will briefly outline the current state of these investigations. * To whom correspondence should be addressed: Tel.: +43-512-507-3787; Fax: +43-512-507-2836; E-mail: bernhard.e.flucher@uibk.ac.at     

Bileaflet Aortic Valve Prosthesis Pivot Geometry Influences Platelet Secretion and Anionic Phospholipid Exposure

The clinical histories of the Medtronic Parallel (MP) and St. Jude Medical (SJM) Standard valves suggest pivot geometry influences the thrombogenic characteristics of bileaflet prostheses. This work studied the effects of various pivot geometries on markers of platelet damage in a controlled, in vitro apparatus. The Medtronic Parallel valve, two St. Jude Medical valves, and two demonstration prostheses were used to study the effects of bileaflet pivot design, gap width, and size on platelet secretion and anionic phospholipid expression during leakage flow. A centrifugal pump was used to drive blood through a circuit containing a bileaflet prosthesis. Samples were taken at set time intervals after the start of the pump. These samples were analyzed by cell counting, flow cytometry, and enzyme-linked immunosorbant assay. No significant differences were observed in platelet secretion or anionic phospholipid expression between experiments with the SJM 27 Standard regular leaker, the SJM 20 regular leaker, and the MP 27 valves. Significant differences in platelet secretion and anionic phospholipid expression were observed between a SJM 27 Standard regular leaker and a SJM 27 high leaker valve. These studies suggest that leakage gap width within bileaflet valve pivots has a significant effect on platelet damage initiated by leakage flow. © 2001 Biomedical Engineering Society. PAC01: 8719Uv, 8719Tt, 8380Lz, 8768+z     

Immunohistochemical and electron microscopic observations of stromal cells in the human oviduct mucosa

Stromal cells in the lamina propria of the human oviduct mucosa are unique cells that can differentiate into decidual cells during ectopic pregnancy in the oviduct. The nature of stromal cells is still unknown. In the present study, we investigated human oviductal stromal cells with transmission electron microscopy and immunohistochemistry and revealed that they had ultrastructural features similar to myofibroblasts and expressed alpha-smooth muscle actin, a marker used to identify myofibroblasts. Primary cilia were also one of the characteristic profiles of the stromal cells. These findings showed that the connective tissue-stromal cells in the human oviduct mucosa are myofibroblasts. They are considered to play an important role in the transport of oocytes by bringing about contraction of the mucosal folds.     

Concurrent infections with vector-borne pathogens associated with fatal anaemia in cattle: haematology and blood chemistry

An outbreak of a fatal haemolytic anaemia in a dairy herd of cattle in Switzerland was shown to be associated with infections with five vector-borne pathogens, namely Anaplasma marginale, A. phagocytophilum, Babesia bigemina, a Theileria spp belonging to the buffeli/sergenti/orientalis complex and haemotrophic Mycoplasma spp. The latter three had not been documented before this outbreak in Switzerland. To characterise the haematological and blood chemical changes in these unique cows, packed cell volume was determined in all 286 blood samples, blood smears, and complete haematology were performed from 285 and 173 blood samples, respectively, and biochemical parameters were assayed in 105 serum samples. Regenerative anaemia was the key sign of illness. Red blood cells of anaemic cattle were hypochromic and macrocytic. Anaemic animals had reduced platelet cell counts and increased total white cell counts. In addition, increased serum bilirubin, blood aspartate aminotransferase, gamma glutamyltransferase, glutamic dehydrogenase and blood urea nitrogen and decreased magnesium, calcium and albumin levels were found in anaemic cattle when compared to animals with normal packed cell volume. Most changes could not be attributed to a single infection. A. marginale seemed to be important in causing the outbreak, but co-infections may have aggravated the disease development and clinical signs. Thus, when encountering cattle with haemolytic anaemia, all of the mentioned pathogens should be included as differential diagnosis.     

L-arginine-dependent killing of intracellular Ehrlichia risticii by macrophages treated with gamma interferon.

Thioglycolate-induced murine peritoneal macrophages infected with Ehrlichia risticii and treated in vitro with gamma interferon (IFN-gamma) developed antiehrlichial activity that eliminated the intracellular bacteria. This antiehrlichial activity was suppressed by NG-monomethyl-L-arginine, a competitive inhibitor of nitric oxide synthesis from L-arginine, but not by L-tryptophan. Increased levels of nitrite, an oxidative product of nitric oxide, were measured in cultures of infected macrophages treated with IFN-gamma. Sodium nitroprusside, which spontaneously releases nitric oxide, also showed the antiehrlichial activity. The antiehrlichial activity by reactive nitrogen intermediates was not mediated by elevation of the cellular concentration of cyclic GMP since the addition of 8-bromo-cyclic GMP itself had no influence on ehrlichial infection of macrophages. Addition of the intracellular iron chelator deferoxamine also inhibited E. risticii infection in vitro. These results suggest that intracellular E. risticii survival is iron dependent and that production of reactive nitrogen intermediates triggers iron loss from critical target enzymes of E. risticii, leading to lethal metabolic inhibition. However, addition of excess FeSO4, ferric citrate, or iron-saturated transferrin did not counteract the antiehrlichial effect induced by IFN-gamma.     

Rapid detection (4 h) of methicillin-resistant Staphylococcus aureus by a bioluminescence method.

A 4-h bioluminescence method for methicillin susceptibility determination was compared with reference methods. Of the Staphylococcus aureus strains tested, 80 were methicillin resistant, 180 were methicillin susceptible, and 10 were borderline susceptible. There was 100% correlation between bioluminescence and reference methods for methicillin-susceptible and methicillin-resistant strains. All borderline-susceptible strains were identified as methicillin resistant by bioluminescence.     

Congenital cytomegalovirus infection in Korean population with very high prevalence of maternal immunity.

In order to asses congenital cytomegalovirus (CMV) infection in Korea, five hundred and seventy five pregnant women (mean age 29.5 +/- 3.8 yrs., mean gestational age at test 37.5 +/- 6.7 weeks) visiting the prenatal clinic at Severance Hospital, Seoul, Korea were studied. CMV IgG antibody was present in 96% (552/575) and IgM antibody was present in 0.7% (4/575) of the pregnant women by the third trimester. Four of 445 cord sera were positive for CMV IgM antibody (0.9%). Urine samples from 514 newborns were tested for the evaluation of congenital CMV infection. Six (1.2%) of 514 newborns excreted CMV in their urine. All the congenitally infected infants had subclinical involvement at birth and during the 12 months of the follow-up period. These results indicate that Korean pregnant women were highly immunized against CMV by the third trimester. Furthermore this study suggests that the rate of congenital CMV infection is relatively as high as rates previously reported from other countries, although there is a very high prevalence of maternal immunity. The incidence of maternal primary infection during pregnancy seems to be rare and therefore most congenital infections in Korea might be following by maternal reactivation or reinfection.     

Fracture behavior of dental composite resins.

Fracture toughness (KIC), critical stress intensity factor, and bending strength of 3 types of commercially available dental composite resins (macrofilled, hybrid and microfilled type) were determined using three point bend specimens. Acoustic Emission (AE), which is the generation of elastic wave due to the release of energy from the localized sources in material, was also detected during the fracture toughness test. Fracture surfaces were examined by scanning electron microscope. The fracture toughness values, AE patterns, and the nature of fracture surface were analyzed to understand fracture behavior of dental composite resins and fracture mechanism for each dental composite resin are proposed.