Single photon emission computed tomographic blood flow and magnetic resonance volume imaging of basal ganglia in Huntington''s disease

During oogenesis in Drosophila, germ cells appear in sequential clusters of 16 interconnected cells. The events surrounding the differentiation of these cells are not fully understood. Here we present genetic and morphological analysis of mutations in the gene stand still (stil). Through complementation analyses we have refined the location of this gene to cyological region 49B-C. Our analyses of ovaries from ethylmethane sulfonate (EMS)-induced mutant alleles of this gene suggest that mutations in the stil gene produce a wide range of phenotypic abnormalities, from the absence of germ cells in the most severe alleles, to egg chambers with cytoskeletal defects in the less severe alleles. Our results suggest a role for this gene in specifying or maintaining a cytoskeletal component, with consequences during oogenesis and possibly during germ line sex determination.     

Utility of the radial-deviated, thumb-abducted lateral radiographic view for the diagnosis of hamate hook fractures: case report

Data from all 225 women operated on for ectopic pregnancy in 1992-1994 at Sahlgrenska University Hospital were collected and compared with three previous cross-sectional investigations from our hospital (1975-1979, 1981-1982 and 1986-1987) in order to evaluate the extent to which surgical treatment and post-operative complications have changed over a 20 year period. Laparoscopic surgery, which was not possible in the 1970s, was used in almost 85% of the ectopic pregnancies in 1992-1994. Conservative treatment was still the most frequently used technique. The complication rate was 1.2% in 1975-1979 when only laparotomies were carried out. After the introduction of laparoscopic surgery (1986-1987), the complication rate rose significantly (7.3%) and continued to increase even when this procedure was established as routine (14.2% in 1992-1994). Post-operative complications were most frequent after conservative laparoscopic surgery (24.4%) while there were no complications after laparotomies. In spite of increasing complication rates the frequency of patients in pre-shock, as well as the proportion of patients with heavy intra-abdominal bleeding and tubal rupture, decreased over time.     

Surgery for asymptomatic carotid stenosis: a study of three patient subgroups

Increasing evidence suggests that non-steroidal anti-inflammatory drugs (NSAID) differ in gastrotoxicity. This study aimed to compare the effects of a short-acting NSAID, tiaprofenic acid, with indomethacin on experimental gastric ulcer healing in a rat model. Similar anti-inflammatory and prostaglandin-inhibitory doses of indomethacin (1 mg/kg) and tiaprofenic acid (2 mg/kg) were administered to rats with acetic acid-induced ulcers. After 2 weeks treatment, rats were killed and ulcer size determined. In addition, histological sections of ulcers were assessed for ulcer contraction and mucosal regeneration. The degree of inhibition of prostaglandin E2 (PGE2) synthesis was 72% at 2 h after tiaprofenic acid and 64% at 2 h after indomethacin administration, respectively. Rats treated with indomethacin for 2 weeks had significantly larger ulcers, both macroscopically and microscopically, than controls. Rats treated with tiaprofenic acid for 2 weeks had ulcers of a similar size to those of controls. Indomethacin-treated ulcers showed a failure in mucosal regeneration. Tiaprofenic acid-treated ulcers had significantly more regeneration than indomethacin-treated ulcers. We conclude that tiaprofenic acid inhibits mucosal prostaglandin levels but does not inhibit experimental gastric ulcer healing. These findings suggest that inhibition of PGE2 synthesis is not the only factor in generating gastrotoxicity and that a shift to low gastrotoxic NSAID may be clinically worthwhile.     

Ultrasonically activated shears in thyroid surgery

BACKGROUND: Ultrasonically activated shears (UAS) have been documented to be both safe and fast devices in laparoscopic surgery. We studied whether the use of UAS would have some advantage in thyroid surgery. METHODS: Thyroidectomies, performed by one senior endocrine surgeon between December 1996 and February 1997, were retrospectively matched, with patients operated on by the same surgeon using the conventional method. RESULTS: Six pairs of total thyroidectomies and one pair of lobectomies could be matched. Mean operating time was 100 minutes for the patients operated on with the UAS and 154 minutes for the patients operated on with the conventional method. The mean operating time with the UAS was thus on average 64.6% of the operation time with the conventional method, with a 95% confidence interval from 50.1% to 83.5% (t = 4.00, 6 df, P = 0.007). CONCLUSIONS: In this material the use of UAS reduced significantly operating time in thyroidectomies.     

Effect of bile/pancreatic secretions on absorption of radioactive or stable zinc. In vivo and in vitro studies

Biliary/pancreatic (B/P) secretions are a major component of endogenous secretions, and endogenously secreted Zn is a primary means of Zn homeostasis. This study examined whether B/P fluid alters the absorption/reabsorption of Zn and, in doing so, whether this contributes to homeostatic control of Zn. Animal experiments utilized rats fed 10 or 300 micrograms Zn/kg diet. An open-ended gut perfusion study in which 65Zn-labeled B/P fluid or 67Zn-labeled and digested diet found significantly decreased Zn absorption from B/P fluid. Although Zn absorption from both sources was less in animals fed diets higher in Zn, there was no interaction of treatment and diet. Further studies utilizing cultured human colon carcinoma cells (CACO-2) as in vitro models of gut enterocytes found that the presence of B/P fluid significantly decreased Zn retention and/or transport and resulted in a redistribution of cellular Zn after 1200 min of incubation. These studies show that a substance in B/P fluid can decrease the absorption of Zn and also suggest that dietary Zn and Zn associated with B/P secretions are absorbed from distinct pools. However, the lack of an interactive effect with diet, and the amount of time required to see differences in CACO-2 cells, suggest that differences in absorption are not a major contributor to Zn homeostasis.     

Efficacy of tertiary butylhydroquinone on the storage and heat stability of liquid canola shortening

The sensory (odor and flavor) and physicochemical characteristics of tertiary butylhydroquinone (TBHQ) treated and butylated hydroxyanisole/toluene (BHA/BHT) treated liquid canola shortenings, subjected to accelerated storage (Schaal oven test at 65°C) and deep fat heating (at 185°C), were determined. Data for the Schaal oven test indicate that TBHQ was effective in retarding oxidative rancidity in liquid canola shortenings. However, addition of the commonly used mixture of BHA/BHT to canola shortenings resulted in only a slight decrease in oxidation during schaal oven storage. The results obtained from deep fat heating of canola liquid shortening show that neither TBHQ nor BHA/BHT was effective in enhancing oxidative and thermal stability of this product.     

The formation of β′-sialon from a montmorillonite-polyacrylonitrile composite by carbothermal reduction: an NMR,TGA, XRD and EM study

The products of carbothermal reduction in N₂ of a nanocomposite between dodecylammonium-exchanged montmorillonite and polyacrylonitrile (PAN) have been studied by solid-state ²⁷Al and ²⁹SiNMR spectroscopy, X-ray diffraction, transmission electron microscopy and thermogravimetry. Comparison with analogous reactions involving sodium-exchanged montmorillonite and dodecylammonium-exchanged montmorillonite (without PAN) shows that in the presence of PAN, the formation of silica, cordierite or mullite is almost completely suppressed. The only crystalline phase detected between 1000 and 1300 °C was a -sialon, having a much higher SiAl ratio (7.051) than that of the precursor clay (2.441). Reduction of the octahedral AlO₆ begins near 1200 °C, forming increasing amounts of Al(N,O)₄ tetrahedra with temperature, so that by 1600 °C, complete reduction to AlN₄ (i.e. bulk AlN) has occurred. In contrast, reduction of the tetrahedral SiO₄ is appreciable at 1100 °C, and is almost complete (SiN₄ tetrahedra only) by 1200 °C. No intermediate Si(N,0)₄ environments are found. By 1600 °C, only the SiC₄ environment (i.e. bulk SiC) remains. A mechanism is suggested, involving the formation of alternating slabs of an amorphous aluminosilicate and carbon at 1000 °C, followed by diffusion of silicon from the outer regions of the aluminosilicate band towards the centre, and sequential reduction of Si(OSi)₄ and Si(OSi)₃ (OAl) groups.     

Isolation and characterization of a monoclonal anti-quadruplex DNA antibody from autoimmune "viable motheaten" mice

A cell line that produces an autoantibody specific for DNA quadruplex structures has been isolated and cloned from a hybridoma library derived from 3-month-old nonimmunized autoimmune, immunodeficient "viable motheaten" mice. This antibody has been tested extensively in vitro and found to bind specifically to DNA quadruplex structures formed by two biologically relevant sequence motifs. Scatchard and nonlinear regression analyses using both one- and two-site models were used to derive association constants for the antibody-DNA binding reactions. In both cases, quadruplexes had higher association constants than triplex and duplex molecules. The anti-quadruplex antibody binds to the quadruplex formed by the promoter-region-derived oligonucleotide d(CGCG4GCG) (Ka = 3.3 x 10(6) M-1), and has enhanced affinity for telomere-derived quadruplexes formed by the oligonucleotides d(TG4) and d(T2G4T2G4T2G4T2G4) (Ka = 5.38 x 10(6) and 1.66 x 10(7) M-1, respectively). The antibody binds both types of quadruplexes but has preferential affinity for the parallel four-stranded structure. In vitro radioimmunofilter binding experiments demonstrated that purified anti-DNA quadruplex antibodies from anti-quadruplex antibody-producing tissue culture supernatants have at least 10-fold higher affinity for quadruplexes than for triplex and duplex DNA structures of similar base composition and length. The antibody binds intramolecular DNA triplexes formed by d(G4T3G4T3C4) and d(C4T3G4T3G4), and the duplex d(CGCGCGCGCG)2 with an affinities of 6. 76 x 10(5), 5.59 x 10(5), and 8.26 x 10(5) M-1, respectively. Competition experiments showed that melted quadruplexes are not effective competitors for antibody binding when compared to native structures, confirming that the quadruplex is bound structure-specifically. To our knowledge, this is the first immunological reagent known to specifically recognize quadruplex structures. Subsequent sequence analysis demonstrates homologies between the antibody complementarity determining regions and sequences from Myb family telomere binding proteins, which are hypothesized to control cell aging via telomeric DNA interactions. The presence of this antibody in the autoimmune repertoire suggests a possible linkage between autoimmunity, telomeric DNA binding proteins, and aging.