Microdot test of foveal function. A comparison with visual acuity at high and low contrast

PURPOSE

To define normal values across age from novel computerized tests of foveal vision and to compare the findings with visual acuity (VA) at high and low contrast.

SUBJECTS AND METHODS

Sixty-one healthy volunteers, aged 22-87, with subjectively normal vision participated in the study. The right eye from each subject was tested with Snellen letter VA at high contrast, at 10% contrast using the Tri-VA test and with the Rarebit Microdot Fovea Test (RMFT), in addition to biomicroscopy and fundus examination.

RESULTS

The median letter VA was 0.77 minimum angle of resolution (MAR; range 0.63-1.54) with a significant decline in letter VA with increasing age (r = 0.7, p < 0.001). The median Tri-VA resolution threshold at 10% contrast was 1.8 MAR (range 0.9-4.1) and a significant age effect (r = 0.7) was observed, most pronounced above 65 years. The median RMFT hit rate was 100% (range 97-100) in the age group below 65 years and 87.5% (range 34-98) in subjects older than 65 years.

CONCLUSION

The study shows a decline in foveal function with age with all three methods, reflecting the loss of neural detectors with increasing age. The hit rate to microdot stimuli appears to be a sensitive measure, which can be used for fine-graded evaluation of foveal function.

Cellular localisation of survivin: impact on the prognosis in colorectal cancer

PURPOSE

The present study was designed to determine whether the nuclear or cytoplasmic expression of survivin, was related to clinicopathological parameters and survival in sporadic colon carcinomas.

METHODS

Western blotting of cell fractions and immunocytochemical methodology were used in five human colon cancer cell lines. Immunohistochemical study was performed in formalin-fixed paraffin-embedded section from 46 patients with sporadic colorectal adenocarcinomas with a polyclonal antibody directed against survivin. Apoptotic index was evaluated by using the M30 antibody. Survival rates were estimated by the Kaplan-Meier method and compared using the log-rank test. Multivariate survival analysis was performed by the Cox proportional hazards model.

RESULTS

Western blotting and immunocytochemistry analyses confirmed that survivin could be detected both in the nucleus and the cytoplasm. Immunohistochemical analysis demonstrated that 39% of tumours expressed survivin in the nucleus and 41% in the cytoplasm. No relationship was observed between survivin expression and clinicopathological features. Unexpectedly, the apoptotic index appeared to be linked with high survivin nuclear expression. Overall, 3-year observed survival rate was 73% in patients with cytoplasmic survivin expression versus 48% for negative expression (P = 0.14). Survival was 72% versus 50% for positive nuclear survivin expression versus negative (P = 0.16). After adjustment for age and stage, cytoplasmic survivin expression was a significant prognostic factor. A high level of expression was associated to a better survival: RR = 0.35 [0.13-0.98], P = 0.045.

CONCLUSION

These results indicate that the analysis of the subcellular expression of survivin is a determining factor to define the prognostic value. Its evaluation, using a polyclonal antibody, might help clinicians in the stratification of patients with colorectal cancer.

Pseudoxanthoma elasticum: a clinical, pathophysiological and genetic update including 11 novel ABCC6 mutations

Pseudoxanthoma elasticum (PXE) is an inherited systemic disease of connective tissue primarily affecting the skin, retina, and cardiovascular system. It is characterised pathologically by elastic fibre mineralisation and fragmentation (so called "elastorrhexia"), and clinically by high heterogeneity in age of onset and the extent and severity of organ system involvement. PXE was recently associated with mutations in the ABCC6 (ATP binding cassette subtype C number 6) gene. At least one ABCC6 mutation is found in about 80% of patients. These mutations are identifiable in most of the 31 ABCC6 exons and consist of missense, nonsense, frameshift mutations, or large deletions. No correlation between the nature or location of the mutations and phenotype severity has yet been established. Recent findings support exclusive recessive inheritance. The proposed prevalence of PXE is 1/25,000, but this is probably an underestimate. ABCC6 encodes the protein ABCC6 (also known as MRP6), a member of the large ATP dependent transmembrane transporter family that is expressed predominantly in the liver and kidneys, and only to a lesser extent in tissues affected by PXE. The physiological substrates of ABCC6 remain to be determined, but the current hypothesis is that PXE should be considered to be a metabolic disease with undetermined circulating molecules interacting with the synthesis, turnover, or maintenance of elastic fibres.

Temozolomide and radiation for aggressive pediatric central nervous system malignancies

This study describes the outcomes of children treated with combinations of temozolomide and radiation therapy for various aggressive central nervous system malignancies. Their age at diagnosis ranged from 1 to 15 years. Patients with focal disease were treated with concomitant temozolomide (daily 75 mg/m) and three-dimensional conformal radiotherapy in a dose that ranged from 50 to 54 Gy, followed by temozolomide (200 mg/m/d x 5 days/month in three patients, 150 mg/m x 5 days/ month in one patient). Patients with disseminated disease were treated with craniospinal radiation (39.6 Gy) before conformal boost. One patient received temozolomide (200 mg/m x 5 days/month) before craniospinal radiation, and one patient received temozolomide (daily 95 mg/m) concomitant with craniospinal radiation and a radiosurgical boost, followed by temozolomide (200 mg/m x 5 days/month). Three patients achieved a partial response during treatment, with two of these patients dying of progressive disease after treatment. One patient has no evidence of disease. Three patients achieved stable disease, with one of these patients dying of progressive disease after treatment. Toxicities observed included low-grade neutropenia, thrombocytopenia, and lymphopenia. The combination of temozolomide and radiotherapy appears to be well tolerated in a variety of treatment schemas for aggressive pediatric central nervous system malignancies. This information is of particular use in designing future studies, given the recent positive results in a randomized study examining the use of temozolomide concomitant with radiation in the treatment of adult glioblastoma.

Open charm yields in d+Au collisions at squareroot[sNN]=200 GeV

Midrapidity open charm spectra from direct reconstruction of D0(D0)-->K-/+pi+/- in d+Au collisions and indirect electron-positron measurements via charm semileptonic decays in p+p and d+Au collisions at squareroot[sNN]=200 GeV are reported. The D0(D0) spectrum covers a transverse momentum (pT) range of 0.1<pT<3 GeV/c, whereas the electron spectra cover a range of 1<pT<4 GeV/c. The electron spectra show approximate binary collision scaling between p+p and d+Au collisions. From these two independent analyses, the differential cross section per nucleon-nucleon binary interaction at midrapidity for open charm production from d+Au collisions at BNL RHIC is dsigma(NN)cc/dy=0.30+/-0.04(stat)+/-0.09(syst) mb. The results are compared to theoretical calculations. Implications for charmonium results in A+A collisions are discussed.

Purification, crystallization and preliminary X-ray analysis of Bacteroides fragilis Zn2+ beta-lactamase

The Zn(2+) beta-lactamase from Bacteroides fragilis (E.C. 3.5.2.6) was overexpressed in Escherichia coli using an isopropylthiogalactoside-inducible T7 RNA polymerase expression system. Crystallization trials by the hanging-drop vapour-diffusion method have yielded two different crystal forms from two slightly different conditions. Crystals of form I belong to the monoclinic space group C2 with unit-cell dimensions a = 56.03, b = 43.98, c = 105.32 A, beta = 112 degrees and diffracted only up to 4.0 A. Crystals of form II are orthorhombic, space group P2(1)2(1)2(1) with unit-cell dimensions a = 48.10, b = 98.05, c = 111.76 A, diffract to at least 2.0 A and are suitable for high-resolution structural analysis.

What is the best way to assess microsatellite instability status in colorectal cancer? Study on a population base of 462 colorectal cancers

The assessment of the microsatellite instability (MSI) status in colorectal cancers is presently warranted for three reasons: 1) as a screening tool for hereditary nonpolyposis colorectal cancer, 2) as a prognostic marker, and 3) as a potential predictive factor of chemotherapy response. The aim of this study was to evaluate, on a large scale with tissue samples coming from a number of different sources, the difficulties met with routine use of immunohistochemistry (IHC) and to determine if it really does offer an accurate alternative to PCR genotyping. Colorectal carcinomas from 462 consecutive patients resected in public or private hospitals were assessed for MSI status by two methods: MSI testing (with BAT-26 microsatellite) and IHC detection of hMLH1, hMSH2, and hMSH6 proteins. Of the 398 cancers tested, immunohistochemistry was noncontributory in 42 (10.5%), focal in 9 (2.3%), and discordant with the PCR results in 36 (9%). For these 87 cases, complementary analyses were performed to explain discrepancy. After additional IHC assay with modified processing protocols, 8 cases remained noncontributory, 2 focal, and 28 discordant: 18 microsatellite stability IHC/MSI PCR and 10 MSI IHC/microsatellite stability PCR. For these discordant cases, we performed a multiplex PCR assay on DNA extracted from the frozen sample and BAT-26 was amplified from DNA extracted from the paraffin blocks used for IHC. Four discordant cases were reclassified after PCR multiplex assay (3 as MSI and 1 as microsatellite stability). Five other cases displayed intratumoral heterogeneity and 19 remained discordant. The discrepancy could be partly explained by variable technical protocols of fixation in the different laboratories, leading to variations in staining quality and difficulties in IHC interpretation. This population-based study is the first one to show that IHC is not sensitive and specific enough to be used routinely. Immunohistochemistry analysis of MMR proteins must be performed in standardized conditions and interpreted by confirmed pathologists. It cannot replace PCR as long as protocols are not optimized and harmonized.

Use of checkerboard DNA-DNA hybridization to study complex microbial ecosystems

It has been difficult to conduct large scale studies of microbiologically complex ecosystems using conventional microbiological techniques. Molecular identification techniques in new probe-target formats, such as checkerboard DNA-DNA hybridization, permit enumeration of large numbers of species in very large numbers of samples. Digoxigenin-labeled whole genomic probes to 40 common subgingival species were tested in a checkerboard hydridization format. Chemifluorescent signals resulting from the hybridization reactions were quantified using a Fluorimager and used to evaluate sensitivity and specificity of the probes. Sensitivity of the DNA probes was adjusted to detect 10(4) cells. In all, 93.5% of potential cross-reactions to 80 cultivable species exhibited signals <5% of that detected for the homologous probe signal. Competitive hybridization and probes prepared by subtraction hybridization and polymerase chain reaction were effective in minimizing cross-reactions for closely related taxa. To demonstrate utility, the technique was used to evaluate 8887 subgingival plaque samples from 79 periodontally healthy and 272 chronic periodontitis subjects and 8126 samples from 166 subjects taken prior to and after periodontal therapy. Significant differences were detected for many taxa for mean counts, proportion of total sample, and percentage of sites colonized between samples from periodontally healthy and periodontitis subjects. Further, significant reductions were observed post therapy for many subgingival species including periodontal pathogens. DNA probes used in the checkerboard DNA-DNA format provide a useful tool for the enumeration of bacterial species in microbiologically complex systems.

Diminished suppression of the P50 auditory evoked potential in bipolar disorder subjects with a history of psychosis

OBJECTIVE

People with schizophrenia, schizoaffective disorder, and bipolar illness share clinical symptoms, biological findings, and genetic susceptibility. Diminished suppression of the P50 auditory evoked potential is a phenotype used in studies of genetic susceptibility in schizophrenia. In patients with acute mania, this inhibitory deficit has been correlated with severity of clinical symptoms. This study addresses whether diminished P50 auditory evoked potential suppression represents a phenotype associated with psychosis in bipolar illness.

METHOD

The P50 auditory evoked potential response to paired stimuli was measured in 64 subjects with bipolar illness. The Structured Clinical Interview for DSM-IV and a life chart determined diagnosis. The Beck Depression Inventory, Young Mania Rating Scale, and the Positive and Negative Syndrome Scale measured severity of current illness. Groups were compared with previously collected data from 36 schizophrenia patients and 42 healthy subjects.

RESULTS

P50 suppression significantly differed between bipolar disorder patients with a lifetime history of psychosis and healthy subjects. P50 suppression in bipolar disorder patients without a history of psychosis did not differ from that of the healthy subjects. Severity of current symptoms did not correlate with P50 suppression.

CONCLUSIONS

A longitudinal history of psychosis in subjects with bipolar illness was associated with diminished suppression of the P50 auditory evoked potential. This deficit may represent a common physiological mechanism associated with the vulnerability to psychosis in people with bipolar illness as well as in people with schizophrenia.

Lactate is mainly fermented to butyrate by human intestinal microfloras but inter-individual variation is evident

AIM

To assess the role of lactate as a precursor for butyrate biosynthesis in human colonic microflora.

METHODS AND RESULTS

Three human faecal microfloras were incubated in vitro with media supplemented with 30 mmol l(-1) unenriched or 13C-enriched lactate. Lactate metabolism and short-chain fatty acid (SCFA) production were quantified. Lactate conversion to butyrate was investigated by gas chromatography-mass spectrometry and the pathways involved were identified by 13C nuclear magnetic resonance spectroscopy. All human faecal microfloras rapidly and completely fermented lactate, yielding approx. 19 mmol l(-1) total SCFAs. However, the SCFA composition varied markedly between microfloras. Butyrate was the main end-product for two microfloras but not for the third (60 and 61%vs 27% of the net concentration of SCFA produced respectively). The latter was typified by its ability to produce propionate as a major product (37%), and valerate (3%). 13C-Labelling showed that butyrate was produced through the acetyl-CoA pathway and that the three microfloras possessed significant differences in their metabolic pathways for lactate consumption.

CONCLUSIONS

In contrast to the ruminal microflora, the human intestinal microflora can utilize both d- and l-lactate as precursors for butyrate synthesis. Inter-individual variation is found.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study suggests that the butyrogenic capability of colonic prebiotics could be related to lactate availability. These findings will direct the development of selection strategies for the isolation of new butyrate-producing bacteria among the lactate-utilizing bacteria present in the human intestinal microfloras.

Azimuthal anisotropy and correlations at large transverse momenta in p + p and Au + Au collisions at square root sNN=200 GeV

Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au + Au collisions at square root s(NN)=200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au + Au collisions to those in p + p at the same energy. The elliptic anisotropy v(2) is found to reach its maximum at p(t) approximately 3 GeV/c, then decrease slowly and remain significant up to p(t) approximately 7-10 GeV/c. Stronger suppression is found in the back-to-back high-p(t) particle correlations for particles emitted out of plane compared to those emitted in plane. The centrality dependence of v(2) at intermediate p(t) is compared to simple models based on jet quenching.

Hybrid fluorocarbon-hydrocarbon CO2-philic surfactants. 2. formation and properties of water-in-CO2 microemulsions

Hybrid fluorocarbon-hydrocarbon (F-H) sulfate surfactants are shown to be efficient stabilizers in water-in-CO2 (w/c) microemulsions. The chain structure and F-H ratio affect the regions of P-T phase stability and aggregation structure in these w/c phases. High-pressure near-infrared spectroscopy and small-angle neutron scattering measurements of microemulsified water provide evidence for the stabilization of w/c microemulsion droplets. The relative lengths of the two chains were found to influence the favored aggregation structure: for symmetric chain surfactants (F8H8, F7H7) spherical reverse micelles are present, but for asymmetric chain surfactants (F7H4, F8H4) extended cylinder aggregates form. These changes in aggregation are consistent with different surfactant packing parameters owing to the controlled variations in molecular structure. Furthermore, the general order of w/c phase transition pressures (F8H8 < F7H7 and F8H4 < F7H4) is in line with estimations of surfactant fractional free volume, as proposed by Johnston et al. (J. Phys. Chem. B 2004, 108, 1962-1966). Studies of adsorption at the poly(dimethylsiloxane)-water interface are shown to be valuable for assessing the CO2-philicity of new surfactants. All in all, the symmetric F8H8 and F7H7 analogues are seen to be the most efficient compounds from this class for applications in CO2.

Hybrid fluorocarbon-hydrocarbon CO2-philic surfactants. 1. synthesis and properties of aqueous solutions

Six different hybrid fluorocarbon-hydrocarbon (F-H) sulfate and sulfonate surfactants, with variations in the relative F/H carbon chain length, have been synthesized and characterized in aqueous solution. These compounds have been targeted for potential activity in densified CO2. Tensiometric data and chemical analyses were consistent with surfactants of high chemical purity. Fluorination in terms of the F/H ratio exerts a strong control over all the surfactant physicochemical properties, including critical micelle concentrations (cmc's) and adsorption isotherms. One of these partially fluorinated surfactants (the sulfonate phi-F6H4) achieves very low surface tensions in water (gamma(cmc) approximately 19 mN m(-1)) more reminiscent of fully fluorinated double-chain compounds. Detailed 19F NMR studies revealed that omega'-CF3 groups can exhibit separate signals for monomeric and micellized forms, hence facilitating cmc determinations. Small-angle neutron scattering investigations confirmed the presence of ellipsoidal or extended disklike micelles, depending on the F-H chain asymmetry. For example, a symmetric hybrid F8H8 generates disklike micelles, whereas chain asymmetry in F8H4 or phi-F6H4 tends to drive cylindrical aggregation structures. These changes are consistent with variations in the surfactant packing parameter caused by the different chain F/H ratios. Hence, adsorption and aggregation are shown to respond in a predictable way to the molecular structure of these unusual surfactants.

[Inguinal pseudotumor: relapse of a pemphigus after 15 years' remission]

INTRODUCTION

Pemphigus vegetans (PV) is a rare type of pemphigus vulgaris. We report a patient with pemphigus vulgaris relapsing as an isolated vegetative tumour.

CASE REPORT

A 59-year-old man was seen in February 2001 for a tumour on the right groin. He had received systemic corticosteroids and cyclophosphamide for pemphigus vulgaris from 1974 to 1985, and he had been in complete remission since 1985. At the time of evaluation, a 10 x 5 x 5 cm, smooth vegetative tumour was seen on the right groin. Biopsies showed spongiosis, acanthosis and some acantholysis. Direct immunofluorescence showed strong deposition of immunoglobulin G within the intercellular substance of the epidermis. Indirect immunofluorescence revealed anti-intercellular antibodies at a titer of 1/800. Immunoblot analysis showed reactivity with the 130 kD pemphigus vulgaris antigen. PVg was diagnosed. Local corticosteroid treatment was initiated. The patient was disease-free at follow-up three years later.

DISCUSSION

Localised forms of pemphigus are very rare. Twenty four other cases have been reported among them just one case of localised PV. Our case report is very unusual because of the variability of the expression of the disease, the high antibody level, the absence of trigger factors, and the efficacy of the local corticosteroid treatment.

Insulin resistance and changes in plasma concentration of TNFalpha, IGF1, and NEFA in dogs during weight gain and obesity

Obesity-induced insulin resistance (IR) is a common problem in humans as well as domestic dogs. It is well-known that this syndrome is associated with many modifications but it is still unclear if the changes are alterations or adaptations. The purpose of this study was to develop obesity-induced IR in dogs, through a long-term overfeeding period, and to explore hormonal and metabolic disturbances associated with the development of this syndrome. Dogs were overfed for 7 months. Body weight increased by 43 +/- 5%, and insulin sensitivity decreased by 44 +/- 5%. Plasma insulin-like growth factor 1 (IGF1), tumour necrosis factor alpha (TNFalpha), and non-esterified fatty acids (NEFA) concentrations progressively increased during the overfeeding period (IGF1: 111 +/- 13 to 266 +/- 32 ng/ml, p < 0.001; TNFalpha: 5 +/- 5 to 134 +/- 41 pg/ml; NEFA: 0.974 +/- 0.094 to 1.590 +/- 0.127 mmol/l, p < 0.05). These metabolic and hormonal impairments are associated with IR, in obese dogs, and could explain, at least in part, the outbreak of this syndrome.

Un cas de lésion artérielle pelvienne post-traumatique masquée à l'angiographie par l'emploi d'un pantalon antichoc

Initial reports of pneumatic anti-shock garment (PASG) in severely hypotensive patients appeared promising. Nevertheless, large-scale studies in prehospital settings have shown no overall reduction in mortality rates among hypotensive patients with application of the PASG. However, in a subsample of patients with blood pressure < or =50 mmHg, PASG seems to be useful to reduce bleeding and improve survival. To our knowledge, our case report is the first which directly showns on angiography the hemostatic effect of PASG on pelvic trauma bleeding. In spite of its possible complications, PASG remains one of the tools of trained trauma teams who regularly treated severe haemorrhagic shock.

Mandatory pharmacosurveillance--a Canadian model for access to therapy and research

Regulatory authorities in Canada have expressed a vital need for pharmacoepidemiological data on long-term effectiveness, safety, and cost-benefit of new therapies, particularly in comparison to currently available therapies, in routine clinical practice to allow informed decision making in listing new therapies on formulary. We describe the evolution of a new model of pharmacosurveillance involving a partnership between academic and community rheumatologists, government, and industry whereby access to therapy is conditional on participation in an industry-funded pharmacosurveillance study that assesses long-term effectiveness, safety, and cost-benefit. Though funded by industry, the program is administered by government and designed and operated at arms length from industry. The clinic data sheets are available at www. altarheum.com. The program also provides a sustainable model for promoting observational research on therapeutics in general.