Heterotopia in Individuals with 22q11.2 Deletion Syndrome.

BACKGROUND AND PURPOSE: MR imaging studies and neuropathologic findings in individuals with 22q11.2 deletion syndrome show anomalous early brain development. We aimed to retrospectively evaluate cerebral abnormalities, focusing on gray matter heterotopia, and to correlate these with subjects' neuropsychiatric impairments. MATERIALS AND METHODS: Three raters assessed gray matter heterotopia and other morphologic brain abnormalities on 3D T1WI and T2*WI in 75 individuals with 22q11.2 deletion syndrome (27 females, 15.5 [SD, 7.4] years of age) and 53 controls (24 females, 12.6 [SD, 4.7] years of age). We examined the association among the groups' most frequent morphologic findings, general cognitive performance, and comorbid neuropsychiatric conditions. RESULTS: Heterotopia in the white matter were the most frequent finding in individuals with 22q11.2 deletion syndrome (n = 29; controls, n = 0; between-group difference, P < .001), followed by cavum septi pellucidi and/or vergae (n = 20; controls, n = 0; P < .001), periventricular cysts (n = 10; controls, n = 0; P = .007), periventricular nodular heterotopia (n = 10; controls, n = 0; P = .007), and polymicrogyria (n = 3; controls, n = 0; P = .3). However, individuals with these morphologic brain abnormalities did not differ significantly from those without them in terms of general cognitive functioning and psychiatric comorbidities. CONCLUSIONS: Taken together, our findings, periventricular nodular heterotopia or heterotopia in the white matter (possibly related to interrupted Arc cells migration), persistent cavum septi pellucidi and/or vergae, and formation of periventricular cysts, give clues to the brain development disorder induced by the 22q11.2 deletion syndrome. There was no evidence that these morphologic findings were associated with differences in psychiatric or cognitive presentation of the 22q11.2 deletion syndrome.

Health care utilization and excess costs after pelvic fractures among older people in Germany.

Our study demonstrates a strong increase in utilization of inpatient health care and clear excess costs in older people in the first year after pelvic fracture, the latter even after adjustment for several confounders. Excess costs were particularly high in the first few months and mainly attributable to inpatient treatment. INTRODUCTION: We aimed to estimate health care utilization and excess costs in patients aged minimum 60 years up to 1 year after pelvic fracture compared to a population without pelvic fracture. METHODS: In this retrospective population-based observational study, we used routine data from a large statutory health insurance (SHI) in Germany. Patients with a first pelvic fracture between 2008 and 2010 (n=5685, 82% female, mean age 80±9 years) were frequency matched with controls (n=193,159) by sex, age at index date, and index month. We estimated health care utilization and mean total direct costs (SHI perspective) with 95% confidence intervals (CIs) using BCA bootstrap procedures for 52 weeks before and after the index date. We calculated cost ratios (CRs) in 4-week intervals after the index date by fitting mixed two-part models including adjustment for possible confounders and repeated measurement. All analyses were further stratified for men/women, in-/outpatient-treated, and major/minor pelvic fractures. RESULTS: Health care utilization and mean costs in the year after the index date were higher for cases than for controls, with inpatient treatment being particularly pronounced. CRs (95% CIs) decreased from 10.7 (10.2-11.1) within the first 4 weeks to 1.3 (1.2-1.4) within week 49-52. Excess costs were higher for inpatient than for outpatient-treated persons (CRs of 13.4 (12.9-13.9) and 2.3 (2.0-2.6) in week 1-4). In the first few months, high excess costs were detected for both persons with major and minor pelvic fracture. CONCLUSION: Pelvic fractures come along with high excess costs and should be considered when planning and allocating health care resources.

Two redundant octanoyltransferases and one obligatory lipoyl synthase provide protein-lipoylation autonomy to plastids of Arabidopsis.

Octanoyltransferases (LIP2) are important for the lipoylation of several α-ketoacid decarboxylases and glycine decarboxylase, all of which are essential multienzyme complexes of central metabolism, by attaching de novo-synthesised octanoyl moieties to the respective target subunits. Lipoyl synthase (LIP1) then inserts two sulphur atoms each into the protein-bound octanoyl chains to generate the functional lipoamide arms. In plants, most of the above multienzyme complexes occur only in mitochondria. Pyruvate dehydrogenase is an exception, since it also occurs in plastids. Plastidial LIP1 and LIP2 are known, but it is not clear how essential these enzymes are. Here, we report that not just one but two redundant LIP2 isoforms, LIP2p and LIP2p2, operate in plastids of Arabidopsis. The combined deletion of the two isoenzymes is embryo-lethal. Deletion of the plastidial lipoyl synthase LIP1p is also embryo-lethal, indicating that all plastidial LIP1 activity is due to LIP1p. These features suggest that protein lipoylation is based on an autonomous and partially redundant de novo lipoylation pathway in plastids.

[On the prognosis of hip fractures. Assessment of mortality after hip fractures by analyzing overlapping segments of longitudinal data]. / Zur Prognose der Schenkelhalsfraktur. Beurteilung der Mortalität nach Schenkelhalsfraktur durch sektorübergreifende Datenzusammenführung.

BACKGROUND: Data on the treatment of hip fractures in acute care settings have been collected in a report card system for quality assurance in Germany since the beginning of the 1990s. However, there are no data on the long-term outcome and long-term quality of care. MATERIAL AND METHOD: In a retrospective study, data on 1393 patients from 1999 were collected from different sources: from the department of quality assurance at the medical association of Westfalia-Lippe, the Statutory Health Insurance Funds (AOK), and the Medical Review Board of the Statutory Health Insurance Funds (Medizinischer Dienst der Krankenkasse, MDK). Statistical analyses were performed by the Center for Clinical Studies of the University of Düsseldorf. RESULTS: Uni- and multivariate analyses reveal the following prognostic parameters for survival after hip fracture: sex, age, nursing care dependency, living in a nursing home, risk stratification according to ASA, and postoperative complications. Timing of the operation had no affect on survival. CONCLUSIONS: Prognostic factors for the outcome after hip fracture can only be obtained by analyzing data from the hospital stay and the post-hospital setting as well. Chances of survival can be significantly improved by rehabilitative care.

Toxoplasma gondii myosins B/C: one gene, two tails, two localizations, and a role in parasite division.

In apicomplexan parasites, actin-disrupting drugs and the inhibitor of myosin heavy chain ATPase, 2,3-butanedione monoxime, have been shown to interfere with host cell invasion by inhibiting parasite gliding motility. We report here that the actomyosin system of Toxoplasma gondii also contributes to the process of cell division by ensuring accurate budding of daughter cells. T. gondii myosins B and C are encoded by alternatively spliced mRNAs and differ only in their COOH-terminal tails. MyoB and MyoC showed distinct subcellular localizations and dissimilar solubilities, which were conferred by their tails. MyoC is the first marker selectively concentrated at the anterior and posterior polar rings of the inner membrane complex, structures that play a key role in cell shape integrity during daughter cell biogenesis. When transiently expressed, MyoB, MyoC, as well as the common motor domain lacking the tail did not distribute evenly between daughter cells, suggesting some impairment in proper segregation. Stable overexpression of MyoB caused a significant defect in parasite cell division, leading to the formation of extensive residual bodies, a substantial delay in replication, and loss of acute virulence in mice. Altogether, these observations suggest that MyoB/C products play a role in proper daughter cell budding and separation.

Identification of a novel saturable endoplasmic reticulum localization mechanism mediated by the C-terminus of a Dictyostelium protein disulfide isomerase.

Localization of soluble endoplasmic reticulum (ER) resident proteins is likely achieved by the complementary action of retrieval and retention mechanisms. Whereas the machinery involving the H/KDEL and related retrieval signals in targeting escapees back to the ER is well characterized, other mechanisms including retention are still poorly understood. We have identified a protein disulfide isomerase (Dd-PDI) lacking the HDEL retrieval signal normally found at the C terminus of ER residents in Dictyostelium discoideum. Here we demonstrate that its 57 residue C-terminal domain is necessary for intracellular retention of Dd-PDI and sufficient to localize a green fluorescent protein (GFP) chimera to the ER, especially to the nuclear envelope. Dd-PDI and GFP-PDI57 are recovered in similar cation-dependent complexes. The overexpression of GFP-PDI57 leads to disruption of endogenous PDI complexes and induces the secretion of PDI, whereas overexpression of a GFP-HDEL chimera induces the secretion of endogenous calreticulin, revealing the presence of two independent and saturable mechanisms. Finally, low-level expression of Dd-PDI but not of PDI truncated of its 57 C-terminal residues complements the otherwise lethal yeast TRG1/PDI1 null mutation, demonstrating functional disulfide isomerase activity and ER localization. Altogether, these results indicate that the PDI57 peptide contains ER localization determinants recognized by a conserved machinery present in D. discoideum and Saccharomyces cerevisiae.

A myosin I is involved in membrane recycling from early endosomes.

Geometry-based mechanisms have been proposed to account for the sorting of membranes and fluid phase in the endocytic pathway, yet little is known about the involvement of the actin-myosin cytoskeleton. Here, we demonstrate that Dictyostelium discoideum myosin IB functions in the recycling of plasma membrane components from endosomes back to the cell surface. Cells lacking MyoB (myoA(-)/B(-), and myoB(-) cells) and wild-type cells treated with the myosin inhibitor butanedione monoxime accumulated a plasma membrane marker and biotinylated surface proteins on intracellular endocytic vacuoles. An assay based on reversible biotinylation of plasma membrane proteins demonstrated that recycling of membrane components is severely impaired in myoA/B null cells. In addition, MyoB was specifically found on magnetically purified early pinosomes. Using a rapid-freezing cryoelectron microscopy method, we observed an increased number of small vesicles tethered to relatively early endocytic vacuoles in myoA(-)/B(-) cells, but not to later endosomes and lysosomes. This accumulation of vesicles suggests that the defects in membrane recycling result from a disordered morphology of the sorting compartment.

Antimicrobial use in long-term-care facilities. SHEA Long-Term-Care Committee.

There is intense antimicrobial use in long-term-care facilities (LTCFs), and studies repeatedly document that much of this use is inappropriate. The current crisis in antimicrobial resistance, which encompasses the LTCF, heightens concerns of antimicrobial use. Attempts to improve antimicrobial use in the LTCF are complicated by characteristics of the patient population, limited availability of diagnostic tests, and the virtual absence of relevant clinical trials. This position paper recommends approaches to management of common infections in LTCF patients and proposes minimal standards for an antimicrobial review program. In developing these recommendations, the position paper acknowledges the unique aspects of provision of care in the LTCF.

Dictyostelium myosin IK is involved in the maintenance of cortical tension and affects motility and phagocytosis.

Dictyostelium discoideum myosin Ik (MyoK) is a novel type of myosin distinguished by a remarkable architecture. MyoK is related to class I myosins but lacks a cargo-binding tail domain and carries an insertion in a surface loop suggested to modulate motor velocity. This insertion shows similarity to a secondary actin-binding site present in the tail of some class I myosins, and indeed a GST-loop construct binds actin. Probably as a consequence, binding of MyoK to actin was not only ATP- but also salt-dependent. Moreover, as both binding sites reside within its motor domain and carry potential sites of regulation, MyoK might represent a new form of actin crosslinker. MyoK was distributed in the cytoplasm with a significant enrichment in dynamic regions of the cortex. Absence of MyoK resulted in a drop of cortical tension whereas overexpression led to significantly increased tension. Absence and overexpression of MyoK dramatically affected the cortical actin cytoskeleton and resulted in reduced initial rates of phagocytosis. Cells lacking MyoK showed excessive ruffling, mostly in the form of large lamellipodia, accompanied by a thicker basal actin cortex. At early stages of development, aggregation of myoK null cells was slowed due to reduced motility. Altogether, the data indicate a distinctive role for MyoK in the maintenance and dynamics of the cell cortex.

Disruption of a dynamin homologue affects endocytosis, organelle morphology, and cytokinesis in Dictyostelium discoideum.

The identification and functional characterization of Dictyostelium discoideum dynamin A, a protein composed of 853 amino acids that shares up to 44% sequence identity with other dynamin-related proteins, is described. Dynamin A is present during all stages of D. discoideum development and is found predominantly in the cytosolic fraction and in association with endosomal and postlysosomal vacuoles. Overexpression of the protein has no adverse effect on the cells, whereas depletion of dynamin A by gene-targeting techniques leads to multiple and complex phenotypic changes. Cells lacking a functional copy of dymA show alterations of mitochondrial, nuclear, and endosomal morphology and a defect in fluid-phase uptake. They also become multinucleated due to a failure to complete normal cytokinesis. These pleiotropic effects of dynamin A depletion can be rescued by complementation with the cloned gene. Morphological studies using cells producing green fluorescent protein-dynamin A revealed that dynamin A associates with punctate cytoplasmic vesicles. Double labeling with vacuolin, a marker of a postlysosomal compartment in D. discoideum, showed an almost complete colocalization of vacuolin and dynamin A. Our results suggest that that dynamin A is likely to function in membrane trafficking processes along the endo-lysosomal pathway of D. discoideum but not at the plasma membrane.

Ethane-freezing/methanol-fixation of cell monolayers: a procedure for improved preservation of structure and antigenicity for light and electron microscopies.

In order to dissect at the ultrastructural level the morphology of highly dynamic processes such as cell motility, membrane trafficking events, and organelle movements, it is necessary to fix/stop time-dependent events in the millisecond range. Ideally, immunoelectron microscopical labeling experiments require the availability of high-affinity antibodies and accessibility to all compartments of the cell. The biggest challenge is to define an optimum between significant preservation of the antigenicity in the fixed material without compromising the intactness of fine structures. Here, we present a procedure which offers an opportunity to unify preparation of cell monolayers for immunocytochemistry in fluorescence and electron microscopy. This novel strategy combines a rapid ethane-freezing technique with a low temperature methanol-fixation treatment (EFMF) and completely avoids chemical fixatives. It preserves the position and delicate shape of cells and organelles and leads to improved accessibility of the intracellular antigens and to high antigenicity preservation. We illustrate the establishment of this procedure using Dictyostelium discoideum, a powerful model organism to study molecular mechanisms of membrane trafficking and cytoskeleton.

A model for the unusual kinetics of thermal denaturation of rubredoxin.

The thermal denaturation of the simple, redox-active iron protein rubredoxin is characterized by a slow, irreversible decay of the characteristic red color of the iron center at elevated temperatures in the presence of oxygen at pH 7.8. The denaturation rate is essentially constant and the time period for complete bleaching is nearly independent of protein concentration. These two characteristics of the kinetics can be fit by a simple self-catalyzed kinetics model consisting of the combination of a first-order decay and catalysis by some product of that decay, i.e., dP/dt = k1[A] + (k2[P][A])/(K(m) + [A]), where A is native rubredoxin, P, is unspecified product, k1 is a first-order rate constant, and k2 and K(m) are the catalytic constants. In order for the second term to be of this simple form over the full course of a decay, the model must include the condition that the reaction is effectively irreversible. This model has properties which suggest other biological roles in regulation (changes in k1 or k2 can dramatically modulate the kinetics), in timing (titer-independent fixed reaction time), and in self-activation reactions. At one extreme (k1 >> k2) the kinetics becomes exponential, but at the other extreme (k2 >> k1) they show a dramatic and rapid terminal increase after a lag period. Some obvious possible roles in the kinetics of programmed cell death, prion disease, and protease autoactivation are discussed.

Dictyostelium discoideum protein disulfide isomerase, an endoplasmic reticulum resident enzyme lacking a KDEL-type retrieval signal.

The primary activity of protein disulfide isomerase (PDI), a multifunctional resident of the endoplasmic reticulum (ER), is the isomerization of disulfide bridges during protein folding. We isolated a cDNA encoding Dictyostelium discoideum PDI (Dd-PDI). Phylogenetic analyses and basic biochemical properties indicate that it belongs to a subfamily called P5, many members of which differ from the classical PDIs in many respects. They lack an intervening inactive thioredoxin module, a C-terminal acidic domain involved in Ca2+ binding and a KDEL-type retrieval signal. Despite the absence of this motif, the ER is the steady-state location of Dd-PDI, suggesting the existence of an alternative retention mechanism for P5-related enzymes.

Antimicrobial use in long-term-care facilities.

There is intense antimicrobial use in long-term-care facilities (LTCF), and studies repeatedly document that much of this use is inappropriate. The current crisis in antimicrobial resistance, which encompasses the LTCF, heightens concerns of antimicrobial use. Attempts to improve antimicrobial use in the LTCF are complicated by characteristics of the patient population, limited availability of diagnostic tests, and virtual absence of relevant clinical trials. This article recommends approaches to management of common LTCF infections and proposes minimal standards for an antimicrobial review program. In developing these recommendations, the article acknowledges the unique aspects of provision of care in the LTCF.

Short-term water stress leads to a stimulation of sucrose synthesis by activating sucrose-phosphate synthase.

The aim of this work was to identify which aspects of photosynthetic metabolism respond most sensitively to leaf water deficit. Spinach (Spinacia oleracea L.) leaf discs were floated on sorbitol concentrations of increasing molarity and changes of the protoplast volume were estimated using [(14)C]sorbitol and (3)H2O penetration. Detached leaves were also wilted until 10% of their fresh weight was lost. Photosynthesis was studied at very high external CO2 concentrations, to eliminate the effect of closing stomata. There was no large inhibition of CO2 fixation after wilting leaves, or until the external water deficit was greater than-1.2 MPa. However, partitioning changed markedly at these moderate water deficits: more sucrose and less starch was made. When an inhibition of CO2-saturated photosynthesis did appear at a water deficit of-2.0 MPa and above, measurements of chlorophyll-fluorescence quenching and metabolite levels showed the thylakoid reactions were not especially susceptible to short-term water stress. The inhibition was accompanied by a small increase of the triose phosphate: ribulose-1,5-bisphosphate ratio, showing regeneration of ribulose-1,5-bisphosphate was affected. However, there was also a general increase of the estimated concentrations of most metabolites, indicating that there is no specific site for the inhibition of photosynthesis. Increasing water deficit led to a large increase of fructose-2,6-bisphosphate. This is explained in terms of a simultaneous increase of fructose-6-phosphate and inorganic phosphate as the cell shrinks. The high fructose-2,6-bisphosphate led to the accumulation of triose phosphates, and the potential significance of this for protection against photoinhibition is discussed. There was an increase in the extractable activity of sucrose-phosphate synthase. This was only detected when the enzyme was assayed in conditions which distinguish between different kinetic forms which have previously been identified in spinach leaves. It is proposed that activation of sucrose-phosphate synthase is one of the first sites at which spinach leaves respond to a rising water deficit. This could be of importance for osmoregulation.

A multi-hospital hepatitis B vaccine program: prevalence of antibody and acceptance of vaccination among high-risk hospital employees.

In July 1982, five Hartford hospitals embarked on a joint hospital-sponsored program to immunize high-risk employees against hepatitis B virus (HBV). The program included a questionnaire to characterize relative risk, serology for anti-HBs, vaccination and a follow-up survey of vaccine non-recipients. Of 2,065 employees who were considered to be at high-risk for infection with HBV, 1,894 (91.7%) responded to the screening questionnaire and 1,279 (67.5%) were tested for anti-HBs serology. The prevalence of antibody varied from hospital to hospital; the highest prevalence (10.9%) was observed at one of the urban university-affiliated community hospitals and the lowest prevalence (4.1%) was reported from the smaller, rural hospital. The prevalence of antibody also varied greatly within the high-risk groups; the highest prevalence of antibody was seen among surgical house officers (15%). The rate of acceptance of vaccine among hospitals ranged from 57.5% to 23.7%. Reasons for vaccine non-acceptance included fear of as yet unknown side effects, perceived low risk of hepatitis acquisition and possible effects on present or future pregnancies. Our experience illustrates some of the epidemiologic and practical aspects that must be addressed in administering a hospital-based HBV vaccine program. Among the five hospitals, we saw marked inter- and intra-hospital variations in the prevalence of anti-HBs among high-risk employees. More significantly, we observed unexpectedly low rates of vaccine acceptance among high-risk personnel.

Relationships of physician characteristics to performance quality and improvement.

The quality of ambulatory medical care provided by 1,135 physicians in five separate practice settings in the Midwest was measured using predetermined process criteria. Specialists performed better in their own areas of specialized training than did family/general practitioners or specialists performing outside their specialty areas. Physicians with fewer years of practice performed somewhat better than physicians with more years since medical school graduation. Board certification was not consistently related to performance. Performances of the physicians improved following quality assurance interventions in these sites. Differences in the rates of change in performance quality were not consistently related to any of the physician characteristics studied.

Method of evaluating and improving ambulatory medical care.

The usefulness of an action-research model is demonstrated in the evaluation and improvement of ambulatory medical care in a variety of settings: solo office practice, prepaid capitation multiple-specialty group practice, and medical school hospital-based outpatient clinic practice. Improvements in the process of medical care are found to relate directly to the intensity and duration of planned interventions by the study group and are demonstrated to follow organizational changes in the participating sites--primarily managerial and support services initiated by policy decisions in each study site. Improvement in performance approaching one standard deviation results from the most intense intervention, about one-half standard deviation at the next level of intervention, and virtually no change from a simple feedback of performance measures. On the basis of these findings and other operational and research efforts to improve physician performance, it is unlikely that simple feedback of performance measures will elicit a change in behavior. However, noncoercive methods involving health care providers in problem identification, problem solving, and solution implementation are demonstrated to be effective.

Effect of penicillin on the adherence of Streptococcus sanguis in vitro and in the rabbit model of endocarditis.

The effect of penicillin treatment of Streptococcus sanguis in vitro, on subsequent bacterial density in the bloodstream and on cardiac valves in the rabbit model of endocarditis was studied. As experimental tools for this study, isogenic pairs of S. sanguis differing in resistance to streptomycin or rifampin were prepared by genetic transformation. Rabbits with traumatized heart valves received an intravenous inoculation of penicillin treated (1 mug/ml) and untreated S. sanguis, each marked by resistance to either streptomycin or rifampin. The number of penicillin-treated and untreated bacteria attached to the valvular surfaces was determined by differential counting on streptomycin or rifampin containing media. Penicillin pretreatment reduced cardiac valve colonization 5 min after inoculation ("adherence ratio" x 10(8) was 4.11 for the control and 3.66 for the penicillin-treated bacteria, P < 0.001). The results were not due to differences in serum killing or bacterial densities in the bloodstream. There was no difference in valvular bacterial densities 24 h after bacterial inoculation (adherence ratio x 10(8), 7.26 untreated vs. 6.34 penicillin-pretreated, P > 0.10). In vitro experiments were performed using platelet-fibrin surfaces to test the possibility that penicillin-induced loss of lipoteichoic acid was responsible for decreased streptococcal adherence. Pretreatment of S. sanguis cultures with inhibitory concentrations of penicillin or with antiserum against lipoteichoic acid and precoating of the platelet-fibrin surfaces with lipoteichoic acid, all caused reduction in bacterial adherence. The findings are interpreted as support for the role of lipoteichoic acid as an adhesin in S. sanguis interactions with particular host tissue surfaces.