Whole-exome sequencing identifies ALMS1, IQCB1, CNGA3, and MYO7A mutations in patients with Leber congenital amaurosis

It has been well documented that mutations in the same retinal disease gene can result in different clinical phenotypes due to difference in the mutant allele and/or genetic background. To evaluate this, a set of consanguineous patient families with Leber congenital amaurosis (LCA) that do not carry mutations in known LCA disease genes was characterized through homozygosity mapping followed by targeted exon/whole-exome sequencing to identify genetic variations. Among these families, a total of five putative disease-causing mutations, including four novel alleles, were found for six families. These five mutations are located in four genes, ALMS1, IQCB1, CNGA3, and MYO7A. Therefore, in our LCA collection from Saudi Arabia, three of the 37 unassigned families carry mutations in retinal disease genes ALMS1, CNGA3, and MYO7A, which have not been previously associated with LCA, and 3 of the 37 carry novel mutations in IQCB1, which has been recently associated with LCA. Together with other reports, our results emphasize that the molecular heterogeneity underlying LCA, and likely other retinal diseases, may be highly complex. Thus, to obtain accurate diagnosis and gain a complete picture of the disease, it is essential to sequence a larger set of retinal disease genes and combine the clinical phenotype with molecular diagnosis.     

Spectral Analysis of the High Resolution QRS Complex During Exercise-Induced Ischemia

Background: The effect of acute myocardial infarction and regional ischemia on the frequency content of the ECG signal has been described by several investigators. In the present study, the feasibility of assessing changes in the QRS spectrum during exercise testing, and whether these changes are related to the occurrence of ischemia were examined. Methods: Spectral analysis of the high resolution ECGs from leads V₃, V₄, V₅, and V₆ were performed in two groups of male subjects before, during, and following treadmill exercise testing. Group A included 32 coronary artery disease (CAD) patients, with arteriographically proven >75% obstruction of at least two main coronary arteries, and group B included 30 healthy subjects, without history or symptoms of CAD. Signal averaging and filtering techniques were used in order to enhance the signal-to-noise ratio of the recorded ECGs. The power spectrum of the averaged QRS waveform for the different stages of the exercise testing was computed using a Fast Fourier Transform, and the slope of the linear regression line was found in the frequency range 7.81–249.92 Hz on the plot of log((amplitude)²) versus log(frequency). Results: Regression line slopes immediately after peak exercise were significantly lower for the CAD group than for the healthy subjects in 3 of the 4 examined leads. No significant changes in slopes were found between the two groups at rest or during late recovery. Comparing the differences between slopes at different stages of the test revealed that the difference between postexercise slope and rest slope has lower mean values for the CAD group in all four leads, with a significant difference in lead V6, and for the difference between postexercise slope and recovery slope, lower mean values were found for the CAD group in all four leads, with a significant difference in V5 and V6. Conclusions: These findings indicate that ischemic changes affect the power spectrum of the QRS complex, and result in a steeper regression line on a log-log scale.     

Mechanism of decreased baroreceptor activity in chronic hypertensive rabbits. Role of endogenous prostanoids.

We examined the contribution of endogenous prostanoids to baroreceptor activation in chronic renal hypertension. Baroreceptor activity was recorded from the vascularly isolated carotid sinus during slow ramp increases in pressure in rabbits anesthetized with pentothal and chloralose. Mean arterial pressure averaged 133 +/- 4 mmHg in hypertensive rabbits (one kidney, one wrap, n = 12) and 85 +/- 3 mmHg in normotensive rabbits (one kidney, no wrap, n = 13). Baroreceptor activity was decreased significantly (P less than 0.05) in the hypertensive compared with the normotensive rabbits. The decreased baroreceptor activity could not be explained by decreased distensibility of the carotid sinus (sonomicrometers). Inhibition of the endogenous formation of prostanoids with intrasinus administration of indomethacin (50 microM) decreased baroreceptor activity in normotensive (P less than 0.05) but not in hypertensive rabbits over a wide range of pressures. At a pressure of 120 mmHg, activity declined from 61 +/- 14 spikes/s before indomethacin to 47 +/- 12 spikes/s with indomethacin, i.e., a drop of 24 +/- 4%. In contrast, corresponding values in hypertensive rabbits averaged 41 +/- 13 and 40 +/- 12 spikes/s (-1 +/- 2%). Intrasinus prostacyclin, on the other hand, increased activity in both groups: at 120 mmHg activity increased from 62 +/- 9 to 92 +/- 15 spikes/s (51 +/- 17%) in normotensive rabbits and from 29+/- 7 to 47 +/- 14 spikes/s (68 +/- 23%) in hypertensive rabbits. Neither indomethacin nor prostacyclin (n = 5) influenced the pressure-diameter relation of the carotid sinus. The increase in prostacyclin (6-keto-PGF 1 alpha) formation by the sinus in response to its exposure to arachidonic acid (10 microM) was significant (P less than 0.05) in the normotensives (1,627 +/- 344%; n = 5) but not in the hypertensives (583 +/- 353%; n = 5). We conclude that the decreased baroreceptor activity in chronic hypertension may not be caused by decreased distensibility of the vascular wall of the sinus and that endogenous prostanoids that contribute to baroreceptor activation in normotensive rabbits fail to do so in hypertensive rabbits. This appears to be due to decreased formation of prostacyclin rather than decreased sensitivity of the baroreceptors to prostacyclin. The results suggest a new mechanism that contributes to chronic baroreceptor resetting in hypertension.     

Modulation of in vitro eosinophil progenitors by hydrocortisone: role of accessory cells and interleukins

The growth of human eosinophil progenitors (CFU-Eo) and the modulation of growth by hydrocortisone were studied as functions of the presence of lymphocytes and monocytes in marrow cells under study; and the source of colony-stimulating factors, specifically, media conditioned by macrophage-like cell line, GCT; phytohemagglutinin-stimulated mononuclear cells (PHA-LCM); or the T cell line, MO. CFU-Eo growth was greatest in marrow containing accessory cells as compared to marrow depleted of accessory cells; and in marrow treated with phytohemagglutinin-stimulated leukocyte conditioned media (PHA-LCM) or MO (T cell line)-conditioned medium (MO-CM) as compared with GCT cell- conditioned medium (GCT-CM). Hydrocortisone reproducibly inhibited eosinophil progenitor growth in unfractionated marrow stimulated by GCT- CM. This effect was abrogated by admixing irradiated mononuclear cells or T lymphocytes with the target marrow or by adding interleukin 1 or interleukin 2 (IL-1, IL-2). Inhibition by hydrocortisone did not occur when monocyte and T lymphocyte depleted marrow was studied. Unlike GCT- CM, MO-CM and PHA-LCM stimulated equal proportions of eosinophil progenitors in nondepleted and accessory cell-depleted marrow and demonstrated less hydrocortisone inhibition. However, both GCT-CM and PHA-LCM produced in the presence of hydrocortisone stimulated significantly fewer CFU-Eos in both unfractionated and accessory cell- depleted marrow target populations. These results indicate that the growth of CFU-Eo and inhibition of growth by hydrocortisone is a direct function of a monocyte-T cell interaction and probably is mediated through effects on the production/release of eosinophil colony stimulating factor (Eo-CSF).     

Trunk motor variability in patients with non-specific chronic low back pain

Purpose

To identify and characterize trunk neuromuscular adaptations during muscle fatigue in patients with chronic low back pain (LBP) and healthy participants.

Methods

Forty-six patients with non-specific chronic LBP and 23 healthy controls were asked to perform a trunk muscles fatigue protocol. Surface electromyography was recorded using two adhesive matrix of 64 electrodes applied bilaterally over the erector spinae. Pain score, kinesiophobia and physical disability were analyzed through different questionnaires. To characterize motor variability, dispersion of muscular activity center of gravity was computed. Motor variability between groups was compared using repeated-measures analyses of variance.

Results

Score of disability and kinesiophobia were significantly higher in patients with LBP. Results indicated a significant group effect characterized by an increased motor variability in the healthy group through the entire fatigue task on the left (p = 0.003) and right side (p = 0.048). Interestingly, increasing muscle fatigue led to increased motor variability in both groups (on both sides (p < 0.001) but with a greater increase in the healthy group.

Conclusion

Muscle recruitment is altered in patients with chronic LBP in the presence of muscle fatigue. Consequently, these patients exhibit changes in muscle recruitment pattern and intensity (lower levels of motor variability) during sustained isometric contraction that may be attributed to variation in the control of motor units within and between muscles. However, patients with LBP are able to increase their motor variability over time but with a lower increase compared to healthy participants.     

The Impact of Advances in Instrumentation and Techniques of Colonoscopy from 1988 to 2008 on Inpatient Colonoscopy Performance at a High Volume Endoscopy Unit in the United States: Significantly Shorter Procedure Time,Higher Completion Rate,Performance on Sicker Inpatients,and Near Disappearance of Flexible Sigmoidoscopy

Background and Aims  

Colonoscopy instrumentation and technique have improved from 1988 to 2008. We analyze whether these improvements have resulted in improved colonoscopy performance.     

The Effect of Hypercholesterolemia on Rotator Cuff Disease

Background  

The causes of rotator cuff tendon rupture are multifactorial and still unclear. Intrinsic and extrinsic factors have been implicated as predisposing risk factors for rotator cuff rupture. Previous studies have suggested a relationship between elevated serum lipid profiles and tendon ruptures, although not rotator cuff tears specifically.     

Arachidonic acid-dependent activation of a p22(phox)-based NAD(P)H oxidase mediates angiotensin II-induced mesangial cell protein synthesis and fibronectin expression via Akt/PKB

Angiotensin II (Ang II) induces protein synthesis and hypertrophy through arachidonic acid (AA)- and redoxdependent activation of the serine-threonine kinase Akt/PKB in mesangial cells (MCs). The role of NAD(P)H oxidase component p22( phox ) was explored in this signaling pathway and in Ang II-induced expression of the extracellular matrix protein fibronectin. Ang II causes activation of Akt/PKB and induces fibronectin protein expression, effects abrogated by phospholipase A(2) inhibition and mimicked by AA. Ang II and AAalso elicited an increase in fibronectin expression that was reduced with a dominant negative mutant of Akt/PKB. Exposure of the cells to hydrogen peroxide stimulates Akt/PKB activity and fibronectin synthesis. The antioxidant N-acetylcysteine abolished Ang II- and AA-induced Akt/PKB activation and fibronectin expression. Western blot analysis revealed high levels of p22( phox ) in MCs. Antisense (AS) but not sense oligonucleotides for p22( phox ) prevented ROS generation in response to Ang II and AA. AS p22( phox ) inhibited Ang II- or AA-induced Akt/PKB as well as protein synthesis and fibronectin expression. These data provide the first evidence, in MCs, of activation by AAof a p22( phox )-based NAD(P)H oxidase and subsequent generation of ROS. Moreover, this pathway mediates the effect of Ang II on Akt/PKB-induced protein synthesis and fibronectin expression.     

Phenotypic delineation of the retinal arterial macroaneurysms with supravalvular pulmonic stenosis syndrome

Retinal arterial macroaneurysms with supravalvular pulmonic stenosis (RAMSVPS), also known as Familial Retinal Arterial Macroaneurysms (FRAM) syndrome, is a very rare multisystem disorder. Here, we present a case series comprising ophthalmologic and systemic evaluation of patients homozygous for RAMSVPS syndrome causative IGFBP7 variant. New clinical details on 22 previously published and 8 previously unpublished patients are described. Age at first presentation ranged from 1 to 34 years. The classical feature of macroaneurysms and vascular beading involving the retinal arteries was universal. Follow up extending up to 14 years after initial diagnosis revealed recurrent episodes of bleeding and leakage from macroaneurysms in 55% and 59% of patients, respectively. The majority of patients who underwent echocardiography (18/23) showed evidence of heart involvement, most characteristically pulmonary (valvular or supravalvular) stenosis, often requiring surgical correction (12/18). Four patients died in the course of the study from complications of pulmonary stenosis, cerebral hemorrhage, and cardiac complications. Liver involvement (usually cirrhosis) was observed in eight patients. Cerebral vascular involvement was observed in one patient, and stroke was observed in two. We conclude that RAMSVPS is a recognizable syndrome characterized by a high burden of ocular and systemic morbidity, and risk of premature death. Recommendations are proposed for early detection and management of these complications.     

Salvage therapy for acute myeloid leukemia with fludarabine,cytarabine, and idarubicin with or without gemtuzumab ozogamicin and with concurrent or sequential G‐CSF

The current salvage therapies for relapsed/refractory acute myeloid leukemia (AML) are unsatisfactory. Over the past 7 years, we have used two salvage regimens: fludarabine, cytarabine, and idarubicin with (FLAG‐IM) or without gemtuzumab ozogamicin (GO) (9 mg/m² on Day 8) (FLAG‐I) in relapsed/refractory AML. Three‐quarters of patients also received concurrent G‐CSF. Seventy‐one patients were treated, 23 with FLAG‐I and 48 with FLAG‐IM. The median duration of follow‐up was 30.6 months. The treatment groups were well balanced with median ages of 48 years (range 18–70) and 47 years (range 20–68), unfavorable cytogenetics in 57% and 35%, prior allogeneic stem cell transplant in 43% and 42%, and CR1 duration <1 year in 60% and 67%, respectively, for FLAG‐I and FLAG‐IM. The complete remission (CR) rate in the FLAG‐I group was 39% with an additional 13% achieving a CRp [overall response rate (ORR) 52%]; the CR rate in the FLAG‐IM group was 29% with an additional 27% achieving a CRp (ORR 56%). The median duration of response (DOR; 16.8 vs. 8.3 months), event‐free survival (EFS; 7.4 vs. 4.1 months), and overall survival (OS; 8.8 vs. 5.0 months) trended to favor FLAG‐I over FLAG‐IM. The patients who received G‐CSF concurrent with chemotherapy had superior overall response rate (ORR; 62% vs. 29%, P = 0.026), median EFS (6.2 vs. 3.4 months, P = 0.010), and OS (8.8 vs. 3.9 months, P = 0.004) when compared with those who sequentially received G‐CSF and chemotherapy, regardless of chemotherapy regimen. The addition of GO, at this dose and schedule, to FLAG‐I failed to improve the outcomes in patients with relapsed/refractory AML. The patients who received G‐CSF concurrently with chemotherapy had improved outcomes. Am. J. Hematol., 2009. © 2009 Wiley‐Liss, Inc.