Correlation of Disc Damage Likelihood Scale, visual field, and Heidelberg Retina Tomograph II in patients with glaucoma

PURPOSE

To correlate the analysis of the optic nerve head (ONH) obtained with Disc Damage Likelihood Scale (DDLS), Heidelberg Retina Tomograph II (HRT II), and visual field (VF) parameters (Aulhorn scale, mean deviation [MD], and pattern standard deviation [PSD]) in patients with glaucoma.

METHODS

Sixty-five eyes were evaluated using the DDLS classification. Fifty-seven eyes had stable primary open-angle glaucoma (POAG) and eight eyes were normal (control group). Classification of the ONH was performed using the HRT II, with Moorfields Regression Analysis (MRA) and Cup Shape Measure (CSM) indexes. The VF was examined by Full Threshold test (30-2) using the Humphrey Field Analyzer (HFA) perimeter and evaluated by three

METHODS

Aulhorn's scale of 0 to 6, and two global indices, MD and PSD.

RESULTS

The amount of ONH damage as estimated by the DDLS correlated well with topographic damage determined by HRT II (r=0.923 with MRA and r=0.807 with CSM) and with visual field loss as measured by the MD (r=-0.792) and PSD (r=0.718) of the HFA and Aulhorn field staging system (r=0.849).

CONCLUSIONS

This study shows that evaluation of the ONH using the DDLS provides information that correlates well with VF and with data obtained from HRT II.

A whole-genome scan to map quantitative trait loci for conformation and functional traits in Canadian Holstein bulls

Genetic improvement of livestock populations can be achieved through detection and mapping of genetic markers linked to quantitative trait loci (QTL). With the completion of the bovine genome sequence assembly, single nucleotide polymorphism (SNP) assays spanning the whole bovine genome and research work on large-scale identification, validation, and analysis of genotypic variation in cattle has become possible. A total of 462 Canadian Holstein Bulls were used to test the association between SNP and QTL. Single locus linkage disequilibrium regression model was implemented to perform a whole genome scan to identify and map QTL affecting conformation and functional traits. One thousand five hundred thirty-six SNP markers from introns and exons of potential QTL regions for economically important traits across the bovine genome were selected for association analysis. A total of 45 and 151 SNP were found to be associated with 17 conformation and functional traits at a genome- and chromosome-wise significance level, respectively. Among the 196 significant SNP, 169 of them are newly detected in this study, whereas 27 of them have been reported in previous literature and 161 of these were located in genes and are worth further investigating to potentially identify the causative mutations underlying the QTL. The single locus linkage disequilibrium regression method using SNP marker genotypes has proven to be a successful methodology for detecting and mapping QTL in dairy cattle populations.

Linkage disequilibrium and signatures of selection on chromosomes 19 and 29 in beef and dairy cattle

The objective of this study was to quantify the extent of linkage disequilibrium (LD) on bovine chromosomes 19 and 29 and to study the pattern of selection signatures in beef and dairy breeds (Angus and Holstein) of Bos taurus. The extent of LD was estimated for 370 and 186 single nucleotide polymorphism markers on BTA19 and 29 respectively using the square of the correlation coefficient (r(2)) among alleles at pairs of loci. A comparison of the extent of LD found that the decline of LD followed a similar pattern in both breeds. We observed long-range LD and found that LD dissipates to background levels at a locus separation of about 20 Mb on both chromosomes. Along each chromosome, patterns of LD were variable in both breeds. We find that a minimum of 30 000 informative and evenly spaced markers would be required for whole-genome association studies in cattle. In addition, we have identified chromosomal regions that show some evidence of selection for economically important traits in Angus and Holstein cattle. The results of this study are of importance for the design and application of association studies.

Carotid intimomedial thickness in type 2 diabetic patients and its correlation with coronary risk factors

AIMS

To compare the carotid intimal-medial thickness in type 2 diabetics with and without coronary artery disease (CAD), and to correlate the intimal-medial thickness (IMT) with known coronary risk factors.

METHODS

One hundred and eleven patients of type 2 diabetes were recruited for the study. History and physical examination were recorded. Laboratory investigations included fasting and 2-hour post-prandial blood sugar, blood urea, serum creatinine, lipid profile, glycated haemoglobin, and microalbuminuria. Ultrasonographic scanning of the carotid arteries was performed to measure the carotid IMT. For identification of cases of silent ischaemia, treadmill test (TMT) was performed.

RESULTS

The study group was divided into a non-CAD group (n=40), and a CAD group (n=71). The mean carotid IMT of the group as a whole, was 0.840 +/- 0.2 mm. The mean carotid IMT was significantly higher (p<0.0001) in type 2 diabetics with CAD (both overt and silent) than in those without CAD. In diabetics with CAD, the systolic blood pressure, diastolic blood pressure and triglycerides were found to be predictors of high mean carotid IMT. On subgroup analysis of the cases with silent ischaemia, the variables affecting carotid IMT were serum creatinine, total cholesterol, microalbuminuria/proteinuria, serum triglyceride levels, and diastolic blood pressure.

CONCLUSION

A high carotid IMT is a surrogate and reliable marker of higher risk of CAD amongst type 2 diabetic patients, even in those without overt CAD. The study underlines the utility of carotid IMT as a simple, non-invasive, safe, and cheap screening test for the assessment of risk/prognosis of CAD in type 2 diabetics. We have also demonstrated the usefulness of measuring IMT, as a means to detect silent CAD among type 2 diabetics.

Effect of zinc supplementation on respiratory tract infections in children with cystic fibrosis

Zinc (Zn) has significant anti-oxidant and anti-inflammatory activity. Zn deficiency can occur in subsets of patients with cystic fibrosis (CF) especially those with malabsorption and impaired growth. Although supplemental Zn has significantly reduced infections in various disorders, its efficacy has not been thoroughly investigated in CF. We performed a double blind placebo controlled pilot study to investigate the effect of daily 30 mg elemental Zn for 1 year on the rate of respiratory tract infections (RTIs), use of antibiotics and plasma cytokines in 26 children with CF (ages 7-18 years). Plasma Zn, Cu, inflammatory cytokines and ex vivo generation of IL-2 were measured at baseline and at the end of the study. The number of days of oral antibiotics was lower in Zn treated patients compared to placebo (P = 0.05). However, compared to placebo, the effect of Zn was greater in patients who exhibited low plasma Zn at baseline (P = 0.02) than those who had plasma Zn levels identical to normal subjects (P = 0.55). Zn supplementation was marginally effective in reducing percentage increase in plasma IL-6 and IL-8 while increasing the percentage change in ex vivo generation of IL-2 in isolated mononuclear cell. In conclusion, oral intake of 30 mg/day of Zn reduced the number of days of oral antibiotics used to treat RTIs in children with CF. A higher daily Zn dose may be needed to decrease RTIs and modify immune responses.

Recurrence analysis of strange nonchaotic dynamics in driven excitable systems

Numerous studies have shown that strange nonchaotic attractors (SNAs) can be observed generally in quasiperiodically forced systems. These systems could be one- or high-dimensional maps, continuous-time systems, or experimental models. Recently introduced measures of complexity based on recurrence plots can detect the transitions from quasiperiodic to chaotic motion via SNAs in the previously cited systems. We study here the case of continuous-time systems and experimental models. In particular, we show the performance of the recurrence measures in detecting transitions to SNAs in quasiperiodically forced excitable systems and experimental time series.

Analysis of skin-electrode impedance using concentric ring electrode

A significant contributor to artefact generation in surface electromyography (sEMG) and, functional electrical stimulation (FES) intensity is the skin-to-electrode impedance (Z(S/E)). While using electrolytic gels may initially lower Z(S/E), the impedance may not remain stable. It can vary over time due to changes in underlying structures such as sweat glands and physical deformations due to movements. An experiment seeking to identify major factors in the reduction of Z(S/E), and therefore mitigate these artefacts, was performed by varying a series of control factors on the concentric ring electrode (CRE). Unlike conventional disc electrodes, CREs have small surface areas which may exacerbate Z(S/E) changes. The factors tested were electrode material, electrode size, skin preparation, and surface pressure. This work analyzes how these factors in their various combinations effect changes in Z(S/E) and suggests protocols for improving recording or stimulation with CREs via lowered and consistent Z(S/E).

Detection of anti-Haemonchus contortus antibodies in sheep by dot-ELISA with immunoaffinity purified fraction of ES antigen during prepatency

Haemonchosis is a very common disease in small ruminants caused by H. contortus, a blood sucking parasite causing anaemia that may be fatal particularly to young animals. Therefore, detection of the infection during prepatent period is important for early treatment. Excretory-Secretory (ES) protein of H. contortus was purified through immunoaffinity chromatography. Dot -ELISA was performed with crude ES antigen as well as immunoaffinity purified fraction (F-1) with experimental and natural sera of sheep infected with H. contortus. Solid dot formation took place with 4 day, 1, 2 and 3 weeks post infection sera. Dot formation did not take place with negative control serum and uninfected control animal serum. When crude ES antigens was reacted to natural sheep sera having H. contortus infection, 60% sera samples showed solid dot formation whereas in F-1 fraction 75% of the sera samples showed solid dot indicating purified fraction was a more potent antigen. Crude ES and F-1 were also fractionated through SDS-PAGE. ES antigen revealed polypeptides in the range of 10 to 200 kDa of which 26, 32, 60 and 120 kDa were found more prominent. F-1 fraction on SDS-PAGE analysis revealed only four polypeptides of 26, 32, 60, and 120 of which 60 and 120 kDa were found to be most prominent. Results indicate that the purified fraction of ES antigen may be utilized for early diagnosis of haemonchosis. Further studies on cross antigenicity of this fraction with other nematode and trematode needs to be conducted.

In vivo demonstration of neuroinflammatory molecule expression in brain abscess with diffusion tensor imaging

BACKGROUND AND PURPOSE

Neuroinflammatory molecules, including tumor necrosis factor-alpha, interleukin1-beta, lymphocyte function associated molecule-1, and intercellular cell adhesion molecule-1 contribute to the development of brain abscess. We hypothesized that the high fractional anisotropy (FA) in the brain abscess cavity reflects the upregulation of these neuroinflammatory molecules.

MATERIALS AND METHODS

Diffusion tensor imaging (DTI) was performed in 24 patients with brain abscess and Staphylococcus aureus-treated as well as nontreated Jurket cell lines (at 4 time points: 1, 24, 48, and 72 hours). Neuroinflammatory molecules were quantified from the brain abscess cavity aspirate of the patients as well as from the heat-killed S aureus-treated and nontreated cell lines and correlated with DTI measures.

RESULTS

The DTI-derived FA strongly correlated with the presence of neuroinflammatory molecules in the pus as well as in S aureus-treated cell lines; no such correlation was observed in nontreated cell lines.

CONCLUSIONS

These data indicate that neuroinflammatory molecules confer high diffusion anisotropy inside the brain abscess cavity. We propose that increased FA reflects upregulated inflammatory response in brain abscess.

Characterization of adsorbed silane on fillers used in dental composite restoratives and its effect on composite properties

The purpose was to study the effect of silane treatment of fillers on viscosity, flexural strength, and hydrolytic degradation of experimental dental composite resins fabricated with these fillers. The fillers consisted of a mixture of barium glass and amorphous silica. The resin was mainly based on ethoxylated bisphenol A dimethacrylate and polycarbonate dimethacrylate. The adsorption of silane on the filler surface was characterized by FTIR. There was significant correlation between the adsorbed silane on filler surface and the silane concentration in silane/methanol solution used for filler treatment. The silane concentration varied from 0.75 to 14% by weight. An increase in silane concentration led to a decrease in viscosities of the corresponding composite resins. The flexural strengths of composites with silanated fillers were greater than that of composites with unsilanated fillers: however, no significant difference was found between the flexural strengths of various silanated groups. The resistance to hydrolytic degradation of different composites increased when the fillers were treated with silane and was the highest at 1.1% silane.

Fitting it all in: integration of 12 cross-cutting themes into a School of Medicine curriculum

Changing demographic, social, economic and technological trends have impacted the expectations of the Academic Health Center in preparing physicians to serve the needs of the American society, resulting in revisions to current curricula. In addition to the traditional basic sciences and clinical disciplines, accredited medical schools are required to provide curriculum exposure in behavioral health, communication skills, diversity and cultural awareness, ethics, evidence-based medicine, geriatrics, integrative medicine, pain management, palliative care, public health, socio-economic dynamics, and domestic violence. These themes are considered 'cross-cutting' since it is recognized these important curricular components apply across all years of medical school. In this article, the authors describe a strategic model developed at the University of New Mexico School of Medicine (UNMSOM) to integrate horizontally and vertically 12 cross-cutting themes as an evolving interdisciplinary curriculum reform process. These areas were defined through a combination of internal self-study, external requirements, and student and faculty interest. In the early stage of use of this model at UNMSOM, the authors describe the new cross-cutting themes that have been integrated. Minimal disruption and a spirit of cooperation and acceptance have characterized the curricular change that has been required. Preliminary assessment indicates that the program has been successful.

A kinematic description of the trajectories of Listeria monocytogenes propelled by actin comet tails

The bacterial pathogen Listeria monocytogenes propels itself in the cytoplasm of the infected cells by forming a filamentous comet tail assembled by the polymerization of the cytoskeletal protein actin. Although a great deal is known about the molecular processes that lead to actin-based movement, most macroscale aspects of motion, including the nature of the trajectories traced out by the motile bacteria, are not well understood. Here, we present 2D trajectories of Listeria moving between a glass-slide and coverslip in a Xenopus frog egg extract motility assay. We observe that the bacteria move in a number of fascinating geometrical trajectories, including winding S curves, translating figure eights, small- and large-amplitude sine curves, serpentine shapes, circles, and a variety of spirals. We then develop a dynamic model that provides a unified description of these seemingly unrelated trajectories. A key ingredient of the model is a torque (not included in any microscopic models of which we are aware) that arises from the rotation of the propulsive force about the body axis of the bacterium. We show that a large variety of trajectories with a rich mathematical structure are obtained by varying the rate at which the propulsive force moves about the long axis. The trajectories of bacteria executing both steady and saltatory motion are found to be in excellent agreement with the predictions of our dynamic model. When the constraints that lead to planar motion are removed, our model predicts motion along regular helical trajectories, observed in recent experiments.

Serum prostate-specific antigen levels in Middle Eastern men with subclinical prostatitis

OBJECTIVE

To investigate the influence of subclinical or histologically diagnosed prostatitis on serum prostate-specific antigen (PSA) in patients investigated for prostatic disease in Kuwait.

MATERIALS AND METHODS

Serum PSA was assayed in patients investigated for prostatic disease in Mubarak Al-Kabeer Hospital, Kuwait, between December 2002 and December 2004. These included patients undergoing transrectal ultrasound with needle biopsy of the prostate gland and those who were treated with transurethral resection of the prostate or retropubic prostatectomy. The tissue was evaluated for prostatitis as well as the underlying disease, and the type and severity of prostatitis were compared with levels of serum PSA.

RESULTS

Of the 331 tissue specimens, 18 (5.4%) did not show prostatitis, while 233 (70.4%) with benign prostate and 80 (24.2%) with malignant prostate disease showed prostatitis. Of 270 men with known serum PSA levels, 198 and 72 had benign and malignant prostate disease, respectively. Of the 198, 77 (41%) with benign prostate disease and prostatitis and of the 72, 52 (76%) with malignant prostate disease and prostatitis had serum PSA levels >10 ng/ml.

CONCLUSION

The data showed that although raised serum PSA is more commonly associated with prostate cancer, subclinical prostatitis is a significant source of high serum PSA in over 40% of men in Kuwait. That local factors may obscure the usefulness of serum PSA as a screening tool suggests the need for a locally applicable paradigm to identify prostate cancer.

A randomised controlled trial of ablation of Barrett's oesophagus with multipolar electrocoagulation versus argon plasma coagulation in combination with acid suppression: long term results

BACKGROUND

Many modalities have been used to ablate Barrett's oesophagus (BO). However, long term results and comparative effectiveness are unknown.

AIMS

Our aim was to compare the long term efficacy of achieving complete reversal (endoscopic and histological) between multipolar electrocoagulation (MPEC) and argon plasma coagulation (APC) in BO patients and assess factors influencing successful ablation.

METHODS

Patients with BO, 2-6 cm long, underwent 24 hour pH testing on proton pump inhibitor (PPI) therapy. Patients were then randomised by BO length to undergo ablation with MPEC or APC every 4-8 weeks until endoscopic reversal or maximal of six treatment sessions.

RESULTS

Thirty five BO patients have been followed for at least two years following endoscopic ablation, 16 treated with MPEC and 19 with APC. There was complete reversal of BO in 24 patients (69%); 75% with MPEC and 63% with APC (p = 0.49). There was no difference in the number of sessions required in the two groups. There was no difference in age, pH results, BO length, PPI dose, or hiatal hernia size between patients with and without complete reversal. One patient developed an oesophageal stricture but there were no major complications such as bleeding or perforation.

CONCLUSIONS

In BO patients treated with MPEC or APC in combination with acid suppression, at long term follow up, complete reversal of BO can be maintained in approximately 70% of patients, irrespective of the technique. There are no predictors associated with achieving complete reversal of BO. Continued surveillance is still indicated in the post ablative setting. As yet, these techniques are not ready for clinical application (other than for high grade dysplasia or early oesophageal adenocarcinoma) and cannot be offered outside the research arena.

Computed tomography perfusion of ischaemic stroke patients in a rural Malaysian tertiary referral centre

INTRODUCTION

Computed tomography (CT) perfusion is a new method to diagnose ischaemic stroke especially in developing countries. It identifies the area and is useful to predict the size of final infarction. The aim of this study was to assess cerebral ischaemia with CT perfusion (CTP) among patients with acute ischaemic stroke in Hospital Universiti Sains Malaysia, a tertiary referral centre in a rural setting.

METHODS

42 consecutive unenhanced CT and CTP examinations of the brain in adult patients were evaluated prospectively. Unenhanced CT images were divided into normal, suspicious or frank infarction. CTP images was classified as normal or ischaemic. Subgroup analysis was carried out with a limit of six hours from time of ictus.

RESULTS

Out of 42 patients, 20 had frank infarction on unenhanced CT, 15 had suspicious CT studies, while seven were normal. There was no significant association of demographical, clinical and radiological parameters to CTP in the whole group among acute stroke patients without frank infarction. Among the subgroup of patients without frank infarction, there was no significant association between unenhanced CT and CTP in patients who were studied less than six hours after stroke (p-value is 0.063) as well as those after six hours (p-value is 0.317). The prevalence of a normal unenhanced CT and positive CTP for ischaemia was 22.7 percent (95 percent confidence interval 7.8, 45.4).

CONCLUSION

CTP may be a useful imaging tool for determining cerebral infarction in a rural-based community population, especially in cases where the unenhanced CT is normal. Thrombolysis is a therapeutic option, even when the history of onset of stroke is unclear.

Relationship between Serum Prostate Specific Antigen and the Pattern of Inflammation in Both Benign and Malignant Prostatic Disease in Middle Eastern Men

To determine the effect of prostatitis on serum prostate specific antigen in the diagnosis of prostate cancer in Middle Eastern men, H&E-stained sections of all consecutive prostate specimens were reviewed for diagnosis (malignant or benign) and pattern of inflammation. Inflammation was categorized into acute, active chronic and chronic inactive and graded semi-quantitatively according to previously published criteria. Results were correlated with serum PSA obtained from patients' records. Of 513 prostate specimens reviewed; 435 (84.8%) were benign and 78 (15.2%) were malignant. Chronic inactive prostatitis was present in 259 (204 benign, 55 malignant) and active chronic prostatitis in 221 (204 benign, 17 malignant). Acute prostatitis alone was not observed and prostatitis was absent in 33 (27 benign, 6 malignant). There was no significant difference in the prevalence of inactive chronic prostatitis between benign and malignant specimens (p < 0.071), but active chronic prostatitis was more prevalent in benign specimens (p < 0.001). Increasing serum PSA was observed for increasing grades of both inactive and active chronic prostatitis in both benign and malignant disease. Prostate cancer showed higher serum PSA levels than benign, at different cut-off points (4 ng/ml = p < 0.0001; 8 ng/ml = p < 0.0001; 12 ng/ml = p < 0.0001). However, significant numbers of patients with benign prostate biopsies presented with PSA above 12 ng/ml (82/260 = 32%). We conclude that active chronic prostatitis is common in Middle Eastern men with benign prostatic disease and a significant number of these present with very high PSA levels, some over 300 ng/ml.