Opsin localization and rhodopsin photochemistry in a transgenic mouse model of retinitis pigmentosa

In budding yeast, a protein kinase called Gin4 is specifically activated during mitosis and functions in a pathway initiated by the Clb2 cyclin to control bud growth. We have used genetics and biochemistry to identify additional proteins that function with Gin4 in this pathway, and both of these approaches have identified members of the septin family. Loss of septin function produces a phenotype that is very similar to the phenotype caused by loss of Gin4 function, and the septins are required early in mitosis to activate Gin4 kinase activity. Furthermore, septin mutants display a prolonged mitotic delay at the short spindle stage, consistent with a role for the septins in the control of mitotic events. Members of the septin family bind directly to Gin4, demonstrating that the functions of Gin4 and the septins must be closely linked within the cell. These results demonstrate that the septins in budding yeast play an integral role in the mitosis-specific regulation of the Gin4 kinase and that they carry out functions early in mitosis.     

Specific detection of the genus Serpulina, S. hyodysenteriae and S. pilosicoliin porcine intestines by fluorescent rRNA in situ hybridization

PURPOSE: Our purpose was to evaluate the utility of spectral imaging for multicolor, multichromosome enumeration in human interphase cell nuclei. METHODS: Chromosome-specific probes labeled with different fluorochromes or nonfluorescent haptens were obtained commercially or prepared in-house. Metaphase spreads, interphase lymphocytes, or blastomeres cells were hybridized with either 7 or 11 distinctly different probes. Following 46 hr of hybridization, slides were washed and detected using either a filter-based quantitative image processing system (QUIPS) developed in-house or a commercial spectral imaging system. RESULTS: The filter-based fluorescence microscope system is preferred for simultaneous detection of up to seven chromosome targets because of its high sensitivity and speed. However, this approach may not be applicable to interphase cells when 11 or more targets need to be discriminated. Interferometer-based spectral imaging with a spectral resolution of approximately 10 nm allows labeling of chromosome-specific DNA probes with fluorochromes having greatly overlapping emission spectra. This leads to increases in the number of fluorochromes or fluorochrome combinations available to score unambiguously chromosomes in interphase nuclei. CONCLUSIONS: Spectral imaging provides a significant improvement over conventional filter-based microscope systems for enumeration of multiple chromosomes in interphase nuclei, although further technical development is necessary in its application to embryonic blastomeres. When applied to preconception/preimplantation genetic diagnosis, presently available probes for spectral imaging are expected to detect abnormalities responsible for 70-80% of spontaneous abortions caused by chromosomal trisomies.     

Endoscopic hemostasis in bleeding gastroduodenal ulcer--a contribution to the cost aspect

Endoscopic injections of fibrin glue for the treatment of gastroduodenal ulcer hemorrhage have been increasingly used instead of sclerosing agents since 1987. Sclerosants have the drawback that they themselves have tissue-destroying or rather ulcerogenic effects. A difficult form of administration and a relatively high price are set against the good biological properties of the fibrin glue. In a randomized study comparing fibrin glue with polidocanol there was a statistically significant lower rebleeding rate in the fibrin group. The data of this study were analysed with regard to economic aspects. They showed an improved cost-benefit and cost-effectiveness ratio of the fibrin glue compared with polidocanol.     

The effect of abdominal wall morphology on ultrasonic pulse distortion. Part I. Measurements

The relative importance of the fat and muscle layers of the human abdominal wall in producing ultrasonic wavefront distortion was assessed by means of direct measurements. Specimens employed included six whole abdominal wall specimens and twelve partial specimens obtained by dividing each whole specimen into a fat and a muscle layer. In the measurement technique employed, a hemispheric transducer transmitted a 3.75-MHz ultrasonic pulse through a tissue section. The received wavefront was measured by a linear array translated in the elevation direction to synthesize a two-dimensional aperture. Insertion loss was also measured at various locations on each specimen. Differences in arrival time and energy level between the measured waveforms and computed references that account for geometric delay and spreading were calculated. After correction for the effects of geometry, the received waveforms were synthetically focused. The characteristics of the distortion produced by each specimen and the quality of the resulting focus were analyzed and compared. The measurements show that muscle produces greater arrival time distortion than fat while fat produces greater energy level distortion than muscle, but that the distortion produced by the entire abdominal wall is not equivalent to a simple combination of distortion effects produced by the layers. The results also indicate that both fat and muscle layers contribute significantly to the distortion of ultrasonic beams by the abdominal wall. However, the spatial characteristics of the distortion produced by fat and muscle layers differ substantially. Distortion produced by muscle layers, as well as focal images aberrated by muscle layers, show considerable anisotropy associated with muscle fiber orientation. Distortion produced by fat layers shows smaller-scale, granular structure associated with scattering from the septa surrounding individual fat lobules. Thick layers of fat may be expected to cause poor image quality due to both scattering and bulk absorption effects, while thick muscle layers may be expected to cause focus aberration due to large arrival time fluctuations. Correction of aberrated focuses using time-shift compensation shows more complete correction for muscle sections than for fat sections, so that correction methods based on phase screen models may be more appropriate for muscle layers than for fat layers.     

Managing capital and administrative (indirect) costs to achieve strategic objectives: the dialysis clinic versus the outpatient clinic

During the race for costing accuracy in health care, managers should acknowledge the equal importance of interdepartmental relations. Although newer costing systems can produce more accurate numbers, greater costing accuracy may not always strengthen the organization. This article demonstrates that subsidizing some capital and administrative (indirect) costs for select hospital departments may help to achieve strategic management objectives.     

Radon penetration of concrete slab cracks, joints, pipe penetrations, and sealants

Radon movement through 12 test slabs with different cracks, pipe penetrations, cold joints, masonry blocks, sealants, and tensile stresses characterized the importance of these anomalous structural domains. Diffusive and advective radon transport were measured with steady-state air pressure differences controlled throughout the deltaP = 0 to 60 Pa range. Diffusion coefficients (deltaP = 0) initially averaged 6.5 x 10(-8) m2 s(-1) among nine slabs with only 8% standard deviation, but increased due to drying by 0.16% per day over a 2-y period to an average of 2.0 x 10(-7) m2 s(-1). An asphalt coating reduced diffusion sixfold but an acrylic surface sealant had no effect. Diffusion was 42 times higher in solid masonry blocks than in concrete and was not affected by small cracks. Advective transport (deltaP < or = 60 Pa) was negligible for the slabs (10(-16) m2 permeability), pipe penetrations, and caulked gaps, but was significant for cracks, disturbed pipe penetrations, cold joints, masonry blocks, and concrete under tensile stress. Crack areas calculated to be as small as 10(-7) m2 significantly increased radon advection. Algebraic expressions predict air velocity and effective crack width from enhanced radon transport and air pressures. Masonry blocks, open cracks, and slab cold joints enhance radon penetration but stressed slabs, undisturbed pipe penetrations, and sealed cracks may not.     

Status of iodine deficiency in selected blocks of Kangra District, Himachal Pradesh

Using polymerase chain reaction single strand conformational polymorphism (PCR-SSCP) and EB staining technique, paraffin-embeded sections of 20 hydatidiform mole and 4 choriocarcinoma were detected in the exons 5 and 8 of p53 gene. The results showed that mutations of p53 gene were 0/9 in the normal chorionic villi, 6/20 (30%) in hydatidiform mole and 3/4 in choriocarcinoma. This study suggests that mutations of p53 gene may be an important event in human gestational trophoblastic neoplastigenesis and its progression.     

Structure, subunit topology, and actin-binding activity of the Arp2/3 complex from Acanthamoeba

The Arp2/3 complex, first isolated from Acanthamoeba castellani by affinity chromatography on profilin, consists of seven polypeptides; two actin-related proteins, Arp2 and Arp3; and five apparently novel proteins, p40, p35, p19, p18, and p14 (Machesky et al., 1994). The complex is homogeneous by hydrodynamic criteria with a Stokes' radius of 5.3 nm by gel filtration, sedimentation coefficient of 8.7 S, and molecular mass of 197 kD by analytical ultracentrifugation. The stoichiometry of the subunits is 1:1:1:1:1:1:1, indicating the purified complex contains one copy each of seven polypeptides. In electron micrographs, the complex has a bilobed or horseshoe shape with outer dimensions of approximately 13 x 10 nm, and mathematical models of such a shape and size are consistent with the measured hydrodynamic properties. Chemical cross-linking with a battery of cross-linkers of different spacer arm lengths and chemical reactivities identify the following nearest neighbors within the complex: Arp2 and p40; Arp2 and p35; Arp3 and p35; Arp3 and either p18 or p19; and p19 and p14. By fluorescent antibody staining with anti-p40 and -p35, the complex is concentrated in the cortex of the ameba, especially in linear structures, possibly actin filament bundles, that lie perpendicular to the leading edge. Purified Arp2/3 complex binds actin filaments with a Kd of 2.3 microM and a stoichiometry of approximately one complex molecule per actin monomer. In electron micrographs of negatively stained samples, Arp2/3 complex decorates the sides of actin filaments. EDC/NHS cross-links actin to Arp3, p35, and a low molecular weight subunit, p19, p18, or p14. We propose structural and topological models for the Arp2/3 complex and suggest that affinity for actin filaments accounts for the localization of complex subunits to actin-rich regions of Acanthamoeba.