Testing association between LRRK2 and Parkinson's disease and investigating linkage disequilibrium

BACKGROUND

We and others recently identified the gene underlying PARK8 linked Parkinson's disease (PD). This gene, LRRK2, contains mutations that cause an autosomal dominant PD, including a mutation, G2019S, which is the most common PD causing mutation identified to date. Common genetic variability in genes that contain PD causing mutations has previously been implicated as a risk factor for typical sporadic disease.

METHODS

We undertook a case-control association analysis of LRRK2 in two independent European PD cohorts using 31 tagging single nucleotide polymorphisms (tSNPs) and five potentially functional SNPs. To assess the structure of this locus in different populations, we have performed linkage disequilibrium (LD) analysis using these variants in a human diversity panel.

RESULTS

We show that common genetic variability in LRRK2 is not associated with risk for PD in the European populations studied here. We also show inter-population variability in the strength of LD across this locus.

CONCLUSIONS

To our knowledge this is the first comprehensive analysis of common variability within LRRK2 as a risk factor for PD.

Persistence and the random bond Ising model in two dimensions

We study the zero-temperature persistence phenomenon in the random bond +/-J Ising model on a square lattice via extensive numerical simulations. We find strong evidence for "blocking" regardless of the amount disorder present in the system. The fraction of spins which never flips displays interesting nonmonotonic, double-humped behavior as the concentration of ferromagnetic bonds is varied from zero to one. The peak is identified with the onset of the zero-temperature spin glass transition in the model. The residual persistence is found to decay algebraically and the persistence exponent theta(p) approximately = 0.9 over the range 0.1< or =p< or =0.9. Our results are completely consistent with the result of Gandolfi, Newman, and Stein for infinite systems that this model has "mixed" behavior, namely positive fractions of spins that flip finitely and infinitely often, respectively. [Gandolfi, Newman and Stein, Commun. Math. Phys. 214, 373 (2000).].

Altered plasma matrix metalloproteinase-9/tissue metalloproteinase-1 concentration during the early postoperative period in patients with colorectal cancer

BACKGROUND

The authors have previously demonstrated that insulin-like growth factor binding protein-3 (IGFBP-3) is depleted in plasma for 1 to 3 days after major open surgery (OS), but not after laparoscopic surgery (LS). After surgery, IGFP-3 cleavage occurs rapidly and is likely attributable to altered plasma proteolytic activity. This study aimed to assess plasma proteolysis after both open and closed colorectal resection and, if possible, to identify a protease/protease inhibitor system affected by surgery.

METHODS

Plasma from 88 patients with colorectal cancer (stages I-III) who underwent resection was obtained preoperatively (pre-OP) and on postoperative days (POD) 1 to 3. Plasma proteolytic activity was assessed via zymography. On the basis of the results, specific protease and protease inhibitor concentrations were next measured via enzyme-linked immunoassay (ELISA). Statistical analysis was performed using Wilcoxon's test.

RESULTS

Early after surgery, zymography showed a predominant band representing a 92-kDa gelatinase corresponding to a proform of matrix metalloproteinase-9 (MMP-9), a protease known to cleave IGFBP-3. In OS patients, the mean concentration of plasma MMP-9 was significantly higher on POD 1 than at pre-OP (p < 0.003). On POD 2 and 3, no differences were noted. In the LS group, the mean levels of MMP-9 before and after surgery were comparable. The levels of a natural MMP-9 inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), also were measured. In the OS group, the level of TIMP-1 was significantly higher on POD 1 (p < 0.0003) and POD 2 (p < 0.01) and 3 (p < 0.01) than at pre-OP. In the LS group, a smaller but significant increase in TIMP-1 levels was found between the pre-OP sample and the POD 1 (p < 0.01) and POD 2 (p < 0.01) samples. No difference was noted on POD 3 (p = 0.1).

CONCLUSIONS

Open surgery, but not laparoscopic surgery, is accompanied by a short-lived significant increase in MMP-9 levels, which likely accounts for the decrease in IGFBP-3 levels observed after OS. The transitory nature of MMP-9 imbalance may be attributable to the increase in TIMP-1 levels postoperatively.

PINK1 (PARK6) associated Parkinson disease in Ireland

Mutations in the PINK1 gene have recently been shown to cause autosomal recessive Parkinson disease (PD). The authors assessed the prevalence of PINK1 gene mutations in 290 well-characterized early- and late-onset PD patients from Ireland. In a 51-year-old PD patient with a family history of PD, the authors identified a novel heterozygous mutation (R147H) in exon 2 of the PINK1 gene. Overall, these data indicate that PINK1 mutations are a rare cause of PD in Ireland.

Search for the Higgs boson in H --> WW(*) decays in pp collisions at square root of 1.96 TeV

We present a search for the standard model Higgs boson in H --> WW(*) decays with e+e-, e+/-mu-/+, and mu+mu- final states in pp collisions at a center-of-mass energy of square root of s = 1.96 TeV. The data, collected from April 2002 to June 2004 with the D0 detector, correspond to an integrated luminosity of 300-325 pb(-1), depending on the final state. The number of events observed is consistent with the expectation from backgrounds. Limits from the combination of all three channels on the Higgs boson production cross section times branching ratio sigma x BR(H --> WW(*) are presented.

Revisiting reliability of quantified perineal ultrasound: Bland and Altman analysis of a new protocol for the rectangular coordinate method

AIMS

This study tested the reliability of a new protocol for the rectangular coordinate method of quantifying perineal ultrasound.

METHODS

Representative scans of healthy primiparous females were quantified by positioning a pubic bone template, drawn onto an acetate sheet containing x-y axes, over scans, by aligning the x-axis with the pubic bone central axis. Values for x (D(x)) and y (D(y)) located the urethrovesical junction (UVJ) at Rest, and at maximal Valsalva and Kegel. Range of motion (V-K) was calculated. Bland and Altman analysis, correlations, and t-tests determined intra- and inter-rater reliability, and variance due to designation of the pubic bone central axis (template control).

RESULTS

Correlations averaged 0.72, 0.70, and 0.92 for intra-rater, inter-rater, and template control experiments. D(x) Rest, D(x) Kegel, and V-K were reliable in all experiments. First and second measures for inter-rater D(y) Rest and D(y) Kegel, and template control D(y) Valsalva were significantly different. Bland and Altman analysis showed D(y) Rest, D(y) Kegel, and D(x) and D(y) Valsalva for both reliability experiments to have limits of agreement (LOA's) large enough to explain >or=50% of the actual value ranges. Template control LOA's explained <or=30% of the actual value ranges.

CONCLUSIONS

The reliability of this protocol varied according to the conditions analyzed; accurate reliability assessment of all conditions required Bland and Altman analysis; and the designation of the pubic bone central axis remained a source of variance between investigators. Our results suggest Bland and Altman analysis be used with each study that quantifies perineal ultrasound.

Evidence of a common founder for SCA12 in the Indian population

Spinocerebellar ataxia type 12 (SCA12) is an autosomal dominant cerebellar ataxia associated with the expansion of an unstable CAG repeat in the 5' region of the PPP2R2B gene on chromosome 5q31-5q32. We found that it accounts for approximately 16% (20/124) of all the autosomal dominant ataxia cases diagnosed in AIIMS, a major tertiary referral centre in North India. The length of the expanded allele in this population ranges from 51-69 CAG triplets. Interestingly, all the affected families belong to an endogamous population, which originated in the state of Haryana, India. We identified four novel SNPs and a dinucleotide marker spanning approximately 137 kb downstream of CAG repeat in the PPP2R2B gene. Analysis of 20 Indian SCA12 families and ethnically matched normal unrelated individuals revealed one haplotype to be significantly associated with the affected alleles (P= 0.000), clearly indicating the presence of a common founder for SCA12 in the Indian population. This haplotype was not shared by the American pedigree with SCA12. Therefore, the SCA12 expansion appears to have originated at least twice.

Unidirectional whole body turning: a new lateralising sign in complex partial seizures

BACKGROUND

The lateralising significance of unidirectional whole body turning in patients with complex partial seizures (CPS) arising from the temporal lobe was evaluated.

METHODS

A total of 330 patients undergoing long term video-EEG study were included. "Unidirectional whole body turning" was defined as rotation of the trunk, head, and limbs by >90 degrees and lasting >10 s. EEG correlates, MRI, and SPECT findings were compared and outcome after surgery was noted for patients with follow up data for >1 year.

RESULTS

Unidirectional whole body turning was observed in 13 patients with a mean age of 18+/-8 years. Concordance of the side of whole body turning with the EEG focus and MRI findings was observed in 11 of the 13 patients (84.7%) and in 26 of 28 seizures (92.8%). The six patients who underwent temporal lobectomy or resection of lesion, opposite to the direction of body turning, had good seizure outcome.

CONCLUSION

Unidirectional whole body turning is a new lateralising sign in temporal lobe CPS with good predictive value for epileptogenic focus contralateral to the direction of turning.

Analysis software can put surgical precision into medical device design

Use of finite element analysis software can give design engineers greater freedom to experiment with new designs and materials and allow companies to get products through clinical trials and onto the market faster. This article suggests how.

Measurement of the lifetime difference in the B0(s) system

We present a study of the decay B0(s) --> J/psiphi. We obtain the CP-odd fraction in the final state at time zero, Rperpendicular = 0.16 +/- 0.10(stat) +/- 0.02 (syst), the average lifetime of the (B0(s), B0(s)) system, tau(B0(s)) = 1.39(+0.13)(-0.16)(stat)(+0.01)(-0.02)(syst) ps, and the relative width difference between the heavy and light mass eigenstates, DeltaGamma/Gamma tripple bond (GammaL - GammaH)/Gamma = 0.24(+0.28)(-0.38)(stat)(+0.03)(-0.04)(syst). With the additional constraint from the world average of the lifetime measurements using semileptonic decays, we find tau(B0(s)) = 1.39 +/- 0.06 ps and DeltaGamma/Gamma = 0.25(+0.14)(-0.15). For the ratio of the B0(s) and B0 lifetimes we obtain tau(B0(s))/tau(B0) = 0.91 +/- 0.09(stat) +/- 0.003(syst).

Measurement of semileptonic branching fractions of B mesons to narrow D** states

Using the data accumulated in 2002-2004 with the D0 detector in proton-antiproton collisions at the Fermilab Tevatron collider with a center-of-mass energy of 1.96 TeV, the branching fractions of the decays B --> D0(1)(2420)mu+ vmuX and B --> D2(*0)(2460)mu+ vmuX and their ratio have been measured: B(b --> B) x B(B --> D0(1)mu+ vmuX) x B(D0(*0) --> D*- pi+) = [0.087 +/- 0.007(stat) +/- 0.014(syst)]%; B(b --> B) x B(B --> D2(*0) mu+ vmuX) x B(D2(*0) --> D*- pi+) = [0.035 +/- 0.007(stat) +/- 0.008(syst)]% and [B(B --> D2(*0)mu+ vmuX) x B(D2(*0) --> D*- pi+)]/[B(B --> D0(1)mu+ vmuX) x B(D0(1) --> D*- pi+)] = 0.39 +/- 0.09(stat) +/- 0.12 (syst), where the charge conjugated states are always implied.

Search for large extra spatial dimensions in dimuon production with the d0 detector

We present the results of a search for the effects of large extra spatial dimensions in pp collisions at sqrt[s] = 1.96 TeV in events containing a pair of energetic muons. The data correspond to 246 pb(-1) of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider. Good agreement with the expected background was found, yielding no evidence for large extra dimensions. We set 95% C.L. lower limits on the fundamental Planck scale between 0.85 and 1.27 TeV within several formalisms. These are the most stringent limits achieved in the dimuon channel to date.

Search for supersymmetry via associated production of charginos and neutralinos in final states with three leptons

A search for associated production of charginos and neutralinos is performed using data recorded with the D0 detector at a pp center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider. This analysis considers final states with missing transverse energy and three charged leptons, of which at least two are electrons or muons. No evidence for supersymmetry is found in a data set corresponding to an integrated luminosity of 320 pb-1. Limits on the product of the production cross section and leptonic branching fraction are set. For the minimal supergravity model, a chargino lower mass limit of 117 GeV at the 95% C.L. is derived in regions of parameter space with enhanced leptonic branching fractions.

Search for neutral supersymmetric Higgs Bosons in multijet events at sqrt[s]=1.96 TeV

We have performed a search for neutral Higgs bosons produced in association with bottom quarks in pp collisions, using 260 pb-1 of data collected with the D0 detector in Run II of the Fermilab Tevatron Collider. The cross sections for these processes are enhanced in many extensions of the standard model (SM), such as in its minimal supersymmetric extension at large tanbeta. The results of our analysis agree with expectations from the SM, and we use our measurements to set upper limits on the production of neutral Higgs bosons in the mass range of 90 to 150 GeV.