A structural basis for reading fluency: white matter defects in a genetic brain malformation

BACKGROUND

Multiple lines of evidence have suggested that developmental dyslexia may be associated with abnormalities of neuronal migration or axonal connectivity. In patients with periventricular nodular heterotopia--a rare genetic brain malformation characterized by misplaced nodules of gray matter along the lateral ventricles--a specific and unexpected reading disability is present, despite normal intelligence. We sought to investigate the cognitive and structural brain bases of this phenomenon.

METHODS

Ten adult subjects with heterotopia, 10 with dyslexia, and 10 normal controls were evaluated, using a battery of neuropsychometric measures. White matter integrity and fiber tract organization were examined in six heterotopia subjects, using diffusion tensor imaging methods.

RESULTS

Subjects with heterotopia and those with developmental dyslexia shared a common behavioral profile, with specific deficits in reading fluency. Individuals with dyslexia seemed to have a more prominent phonological impairment than heterotopia subjects. Periventricular nodular heterotopia was associated with specific, focal disruptions in white matter microstructure and organization in the vicinity of gray matter nodules. The degree of white matter integrity correlated with reading fluency in this population.

CONCLUSIONS

We demonstrate that a genetic disorder of gray matter heterotopia shares behavioral characteristics with developmental dyslexia, and that focal white matter defects in this disorder may serve as the structural brain basis of this phenomenon. Our findings represent a potential model for the use of developmental brain malformations in the investigation of abnormal cognitive function.

Herniation of caecum through the foramen of Winslow

The radiological features on plain abdominal imaging and CT in a case of caecal herniation through the foramen of Winslow is presented. This rare condition is associated with a high morbidity and mortality, which emphasizes the importance of accurate preoperative diagnosis.

A pilot crossover study to evaluate the use of Regenecare topical wound gel in patients with cutaneous toxicity caused by epidermal growth factor receptor (HER1/EGFR) inhibitors

19643

Background: Acneform rash, including pain and pruritus, presents as a dose-limiting toxicity for HER1/EGFR (epidermal growth factor receptor) inhibitors which can lead to secondary skin infection. Antibiotics and corticosteroids are treatment options with minimal or moderate success. Better rash management is desirable for optimal use of these agents. Regenecare™ Gel contains 2% lidocaine for local pain management, marine collagen to promote tissue formation, aloe vera to promote circulation and emollient effect, and sodium alginate to absorb exudates. This study evaluates the effectiveness of Regenecare™ Gel in relieving the clinical symptoms of HER1/EGFR inhibitors-induced skin rash. The secondary objective assesses patient tolerability and satisfaction. Methods: A single center, prospective pilot cross- over study of 10–15 cancer patients treated with HER1/EGFR inhibitor. At the occurrence of grade 2 skin rash, subjects who signed an informed consent started applying study gel on the right side of the face and then crossed-over to both sides of the face after 1 week. Subjects were examined weekly for facial evaluations and photographs. The study continued for a total of six weeks. Results: Eight patients were enrolled with 6 evaluable (3 cetuximab, 2 panitumumab, 1 erlotinib). A summary of the itch and pain score responses are outlined below. Comparative analysis for Treatment vs. No Treatment show significant improvement with respect to self-reported level of itch (p=0.019) and pain (p=0.033). All patients tolerated the study gel without any adverse effect and 5 patients were very satisfied with the effectiveness of the gel. Conclusions: Regenecare™ Gel appears effective in relieving EGFR inhibitors rash-associated pruritus and pain based on these preliminary analyses. Study is ongoing for further assessment.

No significant financial relationships to disclose.

[Table: see text]

First-in-human study of the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of PF-00299804, a small molecule irreversible panHER inhibitor in patients with advanced cancer

3599

Background: There are scientific rationale for inhibitors which provide combined and irreversible blockade of HER family members. PF-00299804 is an orally available, potent, irreversible small molecule inhibitor of the HER tyrosine kinases. Methods: The safety, tolerability, PK, PD, and efficacy of PF-00299804 administered orally once daily in 3-week cycles were assessed in patients with advanced solid tumors using an accelerated dose-escalation design. Safety assessments included adverse event (AE), laboratory, ECG, and LVEF assessments. PK parameters were determined after a single lead-in dose and on Day 14 by non-compartmental techniques. PD measures included assessment of HER-related signaling pathways via IHC analyses of serial skin and, in some patients, tumor biopsies. Serial 18F-FDG- PET/CT has been performed on a subset of patients with scans being classified according to modified EORTC criteria by a central reader. Results: 32 pts have been treated across 8 sequential dose levels ranging from 0.5 to 60 mg. The most common AEs were diarrhea, fatigue, nausea, and rash. 3/6 patients at 60 mg experienced a DLT [hand-foot syndrome (1), dehydration related to diarrhea(1), mucositis(1)]. Cmax and AUC of PF-00299804 increased with dose in an approximately proportional manner. Accumulation ranged from 3.3 to 6.8, suggesting a terminal t1/2>24 h. At the 30 mg dose level, mean Day 14 drug concentration was above the predicted efficacious concentration for tumor growth inhibition based on A431 xenograft model. Of 7 sets of PET data evaluated thus far, partial responses (PR) have been observed in 2 patients. A PR as assessed using RECIST criteria has been reported in 1 of 2 patients with advanced refractory NSCLC treated to date. Conclusions: Daily administration of PF-00299804 across many dose levels appears safe and tolerable. Diarrhea, fatigue, nausea, and rash are the most frequent AEs. Evaluation of 45 mg/d as the potential MTD is ongoing. Systemic exposures at doses = 30 mg exceed the threshold for efficacy as predicted from preclinical studies. Clinical and biological activity of PF-00299804 was observed including a PR in 1 of 2 patients with advanced refractory NSCLC.

No significant financial relationships to disclose.

Comparison of 1- and 2-dimensional measurements with volumetric measurements for evaluation of change in tumor size

3563

Background: Change in tumor size is commonly used as a surrogate endpoint for clinical outcome. Measurement of tumor volume, the gold standard for determining tumor size, is not clinically practical. The 2 most commonly used measurements of tumor size ie, longest diameter in axial plane (LD, used in RECIST) and cross product (CP) of LD and the longest perpendicular dimension in axial plane (used in WHO), are surrogates for tumor volume and assume simple tumor geometry. Since most tumors grow and regress irregularly, we determined which of these measurements most accurately reflects change in tumor volume by comparing change in tumor volume calculated using LD or CP with change in measured tumor volume. Methods: Computed tomography (CT) scans of the chest, abdomen, and pelvis were acquired at baseline and 8-week intervals during treatment in 22 patients (pts) enrolled in 2 first-in-human (FIH) clinical trials. CT scans were analyzed by a central reader to obtain LD, CP, and tumor volume. LD (assuming spherical tumor geometry) or CP (assuming spherical or elliptical tumor geometry) was used to calculate volume. The mean bias (μ: mean difference between measured and calculated percent change in tumor volume from baseline [%ΔVol]) and limits of agreement (μ ± 2s [s = standard deviation of difference]) from Bland-Altman analyses (used for assessing agreement between 2 measurement methods) were used for comparisons between measured and calculated %ΔVol. A nested effects model (tumor lesions considered as nested within pts) was used to test significance of differences between measured and calculated %ΔVol. Results: Bland-Altman analyses showed that μ ± 2s was -5% ± 70% for LD, 5% ± 38% for CP (spherical), and 7% ± 33% for CP (elliptical). Nested analyses indicated consistent results with an observed significant difference (p-value = 0.02) between measured and calculated %ΔVol using LD and non-significant differences (p-values = 0.28 and 0.05) using CP (assuming elliptical and spherical geometry respectively). Conclusions: In this diverse FIH population, 2-dimensional tumor measurements (using CP) are better than 1-dimensional tumor measurements (using LD) in representing changes in tumor volume and should decrease noise in the measurement of treatment response.

No significant financial relationships to disclose.

Effect of Arylamine AcetyltransferaseNat3Gene Knockout onN-Acetylation in the Mouse

Arylamine N-acetyltransferases (NAT) catalyze the biotransformation of many important arylamine drugs and procarcinogens. NAT can either detoxify or activate procarcinogens, complicating the manner in which these enzymes may participate in enhancing or preventing toxic responses to particular agents. Mice possess three NAT isoenzymes: Nat1, Nat2, and Nat3. Whereas Nat1 and Nat2 can efficiently acetylate many arylamines, few substrates appear to be appreciably metabolized by Nat3. We generated a Nat3 knockout mouse strain and used it along with our double Nat1/2(-/-) knockout strain to further investigate the functional role of Nat3. Nat3(-/-) mice showed normal viability and reproductive capacity. Nat3 expression was very low in wild-type animals and completely undetectable in Nat3(-/-) mice. In contrast, greatly elevated expression of Nat3 transcript was observed in Nat1/2(-/-) mice. We used a transcribed marker polymorphism approach to establish that the increased expression of Nat3 in Nat1/2(-/-) mice is a positional artifact of insertion of the phosphoglycerate kinase-neomycin resistance cassette in place of the Nat1/Nat2 gene region and upstream of the intact Nat3 gene, rather than a biological compensatory mechanism. Despite the increase in Nat3 transcript, the N-acetylation of p-aminosalicylate, sulfamethazine, 2-aminofluorene, and 4-aminobiphenyl was undetectable either in vivo or in vitro in Nat1/2(-/-) animals. In parallel, no difference was observed in the in vivo clearance or in vitro metabolism of any of these substrates between wild-type and Nat3(-/-) mice. Thus, Nat3 is unlikely to play a significant role in the N-acetylation of arylamines either in wild-type mice or in mice lacking Nat1 and Nat2 activities.

Larval anisakid infections of some tropical fish species from north-west Australia

Despite the commercial and zoonotic importance of larval anisakid infestations of teleosts, their distribution among Australia's diverse marine fish fauna is poorly understood. A preliminary survey of Australia's tropical north-west revealed a generally high prevalence of larval anisakids representing four genera (Anisakis, Terranova, Thynnascaris and Raphidascaris) among only seven fish species. The potential impact of high larval anisakid infections on both the health of recreational fishermen and aquaculture environments is discussed.

Multiple Factor Analysis of the Autonomous Nervous System during PTCA

This study describes the Autonomic Nervous System (ANS) response before, during and after a percutaneous transluminal coronary angioplasty (PTCA). The study population consisted of 37 patients undergoing PTCA from Staff-3 Database. Classical Heart rate variability (HRV) parameters: RR mean, SD, rMSSD, LF, HF, LF/HF and LF/(HF+LF) were extracted and a multiple factorial analysis (MFA) was carried out. Preliminary results show that sympathetic activity increases during and after PTCA, and global HRV decreases during PTCA and increases after PTCA. These findings suggest that MFA provides a powerful tool allowing assessment of ANS's response during PTCA.

Forebrain neural patterns associated with sex differences in autonomic and cardiovascular function during baroreceptor unloading

Generally, women demonstrate smaller autonomic and cardiovascular reactions to stress, compared with men. The mechanism of this sex-dependent difference is unknown, although reduced baroreflex sensitivity may be involved. Recently, we identified a cortical network associated with autonomic cardiovascular responses to baroreceptor unloading in men. The current investigation examined whether differences in the neural activity patterns within this network were related to sex-related physiological responses to lower body negative pressure (LBNP, 5, 15, and 35 mmHg). Forebrain activity in healthy men and women ( n = 8 each) was measured using functional magnetic resonance imaging with blood oxygen level-dependent (BOLD) contrast. Stroke volume (SV), heart rate (HR), and muscle sympathetic nerve activity (MSNA) were collected on a separate day. Men had larger decreases in SV than women ( P < 0.01) during 35 mmHg LBNP only. At 35 mmHg LBNP, HR increased more in males then females (9 ± 1 beats/min vs. 4 ± 1 beats/min, P < 0.05). Compared with women, increases in total MSNA were similar at 15 mmHg LBNP but greater during 35 mmHg LBNP in men [1,067 ± 123 vs. 658 ± 103 arbitrary units (au), P < 0.05]. BOLD signal changes ( P < 0.005, uncorrected) were identified within discrete forebrain regions associated with these sex-specific HR and MSNA responses. Men had larger increases in BOLD signal within the right insula and dorsal anterior cingulate cortex than women. Furthermore, men demonstrated greater BOLD signal reductions in the right amygdala, left insula, ventral anterior cingulate, and ventral medial prefrontal cortex vs. women. The greater changes in forebrain activity in men vs. women may have contributed to the elevated HR and sympathetic responses observed in men during 35 mmHg LBNP.

Characterization of Anaplasma phagocytophilum major surface protein 5 and the extent of its cross-reactivity with A. marginale

Major surface protein 5 (Msp5) of Anaplasma marginale is highly conserved in the genus Anaplasma and the antigen used in a commercially available competitive enzyme-linked immunosorbent assay (cELISA) for serologic identification of cattle with anaplasmosis. This study analyzes the degrees of conservation of Msp5 among various isolates of Anaplasma phagocytophilum and the extent of serologic cross-reactivity between recombinant Msp5 (rMsp5) of Anaplasma marginale and A. phagocytophilum. The msp5 genes from various isolates of A. phagocytophilum were sequenced and compared. rMsp5 proteins of A. phagocytophilum and A. marginale were used separately in an indirect ELISA to detect cross-reactivity in serum samples from humans and dogs infected with A. phagocytophilum and cattle infected with A. marginale. Serum samples were also tested with a commercially available competitive ELISA that uses monoclonal antibody ANAF16C1. There were 100% sequence identities in the msp5 genes among all of the A. phagocytophilum isolates from the United States and a horse isolate from Sweden. Sheep isolates from Norway and dog isolates from Sweden were 99% identical to one another but differed in 17 base pairs from the United States isolates and the horse isolate. Serologic cross-reactivity was identified when serum samples from cattle infected with A. marginale were reacted with rMsp5 of A. phagocytophilum and when serum samples from humans and dogs infected with A. phagocytophilum were reacted with rMsp5 of A. marginale in an indirect-ELISA format. Serum samples from dogs or humans infected with A. phagocytophilum did not cross-react with rMsp5 of A. marginale when tested with the commercially available cELISA. These results suggest that rMsp5 of A. phagocytophilum is highly conserved among United States and European isolates and that serologic distinction between A. phagocytophilum and A. marginale infections cannot be accomplished if rMsp5 from either organism is used in an indirect ELISA.

Design of a methodology for assessing an electrocardiographic telemonitoring system

Recent studies in Bioengineering show a great interest in telemedicine projects, it is motivated mainly for the fast communication technologies reached during the last decade. Since then many telemedicine projects in different areas have been pursued, among them the electrocardiographic monitoring, as well as methodological reports for the evaluation of these projects. In this work a methodology to evaluate an electrocardiographic telemonitoring system is presented. A procedure to verify the operation of Data Acquisition Module (DAM) of an electrocardiographic telemonitoring system is given, taking as reference defined standards, and procedures for the measurement of the Quality of Service (QoS) parameters required by the system in a Local Area Network (LAN). Finally a graphical model and protocols of evaluation are proposed.