Rebound bursts in GABAergic neurons of the thalamic reticular nucleus in postnatal mice

Whole cell patch-clamp recordings from GABAergic cells of thalamic reticular nucleus (RTN) in thalamocortical slices made from postnatal day 6 (P6) to 10 (P10) were used to investigate the pattern of rebound bursts (RBs) triggered by an injection of hyperpolarizing current into RTN cells. The number of RBs in the RTN and the overlying Na(+)/K(+) spikes changed in an age-dependent manner. The generation of RBs depended largely on the amplitude of the after-hyperpolarizations (AHPs). RB patterns in response to hyperpolarizing current injection into relay cells were markedly different from RB patterns in RTN cells with an after-depolarization. GABA(A) receptor antagonist bicuculline methiodide (BMI) changed burst firing patterns, increasing the duration of RB and decreasing the amplitude of AHP in RTN cells. Furthermore, local puffs of NMDA in the presence of BMI induced RBs. K(+) channel blocker 4-aminopyridine partially mimicked the effect of BMI on AHPs. The shapes of RBs were altered by a selective CaMKII inhibitor KN-62, but not by an inactive analog KN-04.

Mesothelin as a marker of response in malignant pleural mesothelioma

7581

Background: Malignant pleural mesothelioma (MPM) is a rare malignancy related to asbestos exposure. Radiological assessment of disease status and treatment response using RECIST criteria is often difficult, therefore blood markers of disease burden may be useful adjunctively. Soluble mesothelin related peptide (sMRP) can distinguish between MPM and benign pleural disease. We performed an exploratory analysis to determine whether sMRP correlates with MPM disease course. Methods: From December 2006 to August 2008 blood samples were collected from MPM patients during clinic visits. Plasma sMRP levels were measured using the MESOMARK assay (Fujirebio diagnostics). Changes in sMRP levels were compared with corresponding radiological tests, scored as progression, stable or disease shrinkage. Results: From 41 patients, 165 samples were collected (median 4/patient; range 2–10). At study entry 34/37 (92%) patients with measurable disease had elevated sMRP (>9ng/ml, range 14–60). In 22 patients receiving chemotherapy or biologic therapy, relative (Fisher's exact test, p=3.2x10–6) and absolute (p=2.6x10–5) changes in sMRP correlated with radiological assessment (Table). All 4 post-surgery surveillance patients, with no evidence of recurrence, had normal sMRP levels (1.8–4.9). Of 8 patients who underwent surgical resection, 7 had elevated pre-operative sMRP that fell to normal post-operatively (Wilcoxon rank (WR) p=0.02). Absolute sMRP rose in all patients with radiological progression (systemic therapy, n=9, WR p=0.004; supportive care, n=10, WR p=0.02). Conclusions: sMRP levels not only correlate with surgical debulking but we report, for the first time, that they also correlate with treatment response and radiological progression in MPM patients undergoing systemic therapy or supportive care. sMRP may be a clinically useful biomarker in MPM clinical trials and in patient management. These findings should be validated prospectively.

[Table: see text]

[Table: see text]

Pegfilgrastim in pediatric sarcoma patients undergoing dose-intensive chemotherapy: Phase II study results

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Background: Children with cancer undergoing dose-intensive chemotherapy often require G-CSF support. Patients (pts) < 2 yrs have the highest risk of prolonged neutropenia due to imprecise dosing and immature drug clearance. Once-per-cycle pegfilgrastim may be beneficial due to neutrophil-mediated clearance that allows adequate serum levels throughout the neutropenic period. Young pts, who receive relatively more myeloablative chemotherapy, should have the highest pegfilgrastim exposure. Methods: Pts ≤21 yrs (age groups 0–5, 6–11, and ≥12 yrs) with sarcoma and scheduled to receive VAdriaC (cycles 1 & 3) and IE (cycles 2 & 4) were randomized 6:1 to receive pegfilgrastim 100 μg/kg or filgrastim (5 μg/kg/d until ANC ≥ 10×109/L) 24 hrs after chemotherapy administration. Post-nadir ANC recovery, incidence of ANC recovery by day 21 of cycles 1 & 3, pharmacokinetics (PK), and safety by age group were evaluated. Results: 43 pts (63% male) received pegfilgrastim (n=37) or filgrastim (n=6). Maximum pegfilgrastim concentration was achieved ∼24-hrs postdose and sustained until ANC nadir. Pegfilgrastim levels fell rapidly as ANC recovered. One child did not achieve ANC recovery by day 21 in cycle 1: an 8-mo-old 7.9-kg boy with non-metastatic undifferentiated sarcoma had 24 days of severe neutropenia in cycle 1. The youngest age group (including this child) had longer duration of severe neutropenia and, consequently, higher pegfilgrastim exposure ( Table ). Treatment-related adverse events were generally mild to moderate (pegfilgrastim 22%, filgrastim 33%); the only treatment-related event reported by >1 pt was bone pain (pegfilgrastim=11%, filgrastim=17%). Conclusions: ANC, PK, and safety profiles in pediatric patients were comparable with those in adults and support pegfilgrastim dosing across pediatric age groups. Consistent with neutrophil-mediated clearance, adequate exposure to pegfilgrastim was maintained in the youngest pts who received the most myelosuppressive chemotherapy.

[Table: see text]

[Table: see text]

MR imaging findings of the uveal schwannoma

BACKGROUND AND PURPOSE

Uveal schwannoma is a rare benign neoplastic proliferation of pure Schwann cells. The purpose of this study was to describe MR imaging features of uveal schwannoma.

MATERIALS AND METHODS

MR images in 6 female patients with uveal schwannoma confirmed by pathologic examination were retrospectively reviewed. MR imaging was performed in all 6 patients, with postcontrast T1-weighted imaging (T1WI) completed in all 6 patients and dynamic contrast-enhanced MR imaging, in 5. MR imaging findings of the tumor were evaluated with emphasis on the location, size, shape, margin, signal intensity, and pattern of enhancement.

RESULTS

The lesions appeared as solitary well-defined ovoid masses in the ciliochoroidal region in 5 patients and in the choroid in 1. With respect to the vitreous body, uveal schwannoma was hyperintense on T1WI spin-echo (SE) images in all 6 patients. The tumors were hypointense to the vitreous body on fast SE (FSE) T2-weighted images (T2WI) in 4 patients and isointense in 1. However, with respect to the brain, uveal schwannoma demonstrated isointensity on T1WI SE images in all 6 patients, isointensity on FSE T2WI images in 5 patients, and hyperintensity on T2WI SE images in 1. On postcontrast T1WI images, 3 patients showed markedly heterogeneous enhancement, and 3 showed markedly homogeneous enhancement.

CONCLUSIONS

Uveal schwannoma should be included in the differential diagnosis when an oval isointense mass relative to brain is seen in the ciliochoroidal region.

A pig-human comparative RH map comprising 20 genes on pig chromosome 13q41 that harbours the ETEC F4ac receptor locus

The enterotoxigenic Escherichia coli (ETEC) F4ac is a major cause of diarrhoea in newborn and young pigs. The locus for the intestinal ETEC F4ac receptor (F4acR) has been mapped to pig chromosome (SSC) 13q41 with known homology to human chromosome (HSA) 3q21 and q29. However, the causative gene and mutation(s) remain unknown. The aim of this study was to characterize gene-derived markers on SSC13q41 for fine mapping of the F4acR locus, and construct a high-resolution pig-human comparative map to select positional candidate genes for F4acR. Pig-specific sequence-tagged site markers were developed for 20 genes that are located in a 6.8-Mb region on HSA3q21 and q29, and a total of 34 single-nucleotide polymorphisms (SNPs) were identified in 14 of 20 markers developed. Eighteen markers were mapped to SSC13q41, while the other two markers (PLXNA1 and KLF15) were assigned to SSC13q32 and SSC7q13, respectively, by radiation hybrid mapping. This result showed that there was a small conserved segment on SSC7 corresponding to HSA3q21. A framework map comprising 18 markers on SSC13q41 was established, refining the synteny breakpoint on SSC13q41 to a region of 12.3 centiRay. The comparative radiation hybrid (RH) map revealed three interesting candidate genes for F4acR from the human genome, viz. MUC4, MUC13 and MUC20. Linkage analysis with six marker polymorphisms revealed that MUC4 had the most significant linkage with the F4acR locus.

High-level secretory production of recombinant human platelet-derived growth factor--BB by Saccharomyces cerevisiae under the non-selective conditions

Recombinant human platelet-derived growth factor-BB (rhPDGF-BB) was produced by Saccharomyces cerevisiae. A two-stage cultivation strategy with mixture of glucose and galactose was developed to enhance rhPDGF-BB production, with its concentration being 32 mg/l fermentation broth under optimal conditions: corn steep powder as nitrogen source, 2 g/1 of glucose concentration at the beginning of induction phase, a pH of 5.0 and 6.5 for cell growth and rhPDGF-BB accumulation. The purification process consisted of yeast supernatant ultrafiltration followed by ion exchange chromatography and molecular sieve, and the recovery of rhPDGF-BB was estimated to be 20.28%. Biological activity of the purified rhPDGF-BB was 3.05 ng/ml.

Quantitative trait loci for porcine white blood cells and platelet-related traits in a White Duroc x Erhualian F resource population

White blood cell count and platelets are implicated as risk factors for common complex diseases. Genetic factors substantially affect these traits in humans and mice. However, little is known about the genetic architecture of these traits in pigs. To identify quantitative trait loci (QTL) for leucocyte- and platelet-related traits in pigs, the total leucocyte number and differential leucocyte counts including the fraction of basophils, eosinophils, lymphocytes, monocytes, neutrophils, and a series of platelet parameters including platelet count, mean platelet volume, platelet distribution width and plateletcrit were measured in 1033 F(2) animals on 240 days from a White Duroc x Erhualian intercross resource population. A total of 183 informative microsatellites distributed across 19 pig chromosomes (SSC) were genotyped across the entire resource population. Thirty-three QTL were identified for the examined traits, including eight genome-wide significant QTL for white blood cells and differential leucocyte counts on SSC2, 7, 8, 12 and 15 and six significant QTL for platelet-related traits on SSC2, 8, 13 and X. Erhualian or White Duroc alleles were not systematically associated with increased phenotypic values. These results not only confirmed many QTL identified previously in the mouse and swine, but also revealed a number of novel QTL for the traits recorded. Moreover, it is the first time that QTL for platelet-related traits in pigs have been reported.

Variation in content of monomeric phenolics during the processing of grape seed and skin flours

Phenolic compounds were extracted from grape seed and skin flours. Three major monomeric phenolics, gallic acid, (+)-catechin and (−)-epicatechin, were identified and quantified by high performance liquid chromatography. To evaluate the feasibility of using both flours for the development of phenolic-rich functional foods, the variation in content of these monomeric phenolics were determined after baking, illumination and microwave radiation processes. The results showed that baking both flours at 110°C had no significant influence on the contents of the three monomeric phenolics. However, after baking at 145°C, the contents of gallic acid exhibited an increasing trend, while the contents of (+)-catechin and (−)-epicatechin gradually declined. During the illumination process, the contents of gallic acid and (+)-catechin in both flours increased, while (−)-epicatechin decreased after 10 days. Microwave processing baked flours for 1 min had no significant effect on the contents of these three monomeric phenolics. After processing for 3 and 5 min, the gallic acid contents significantly increased, but the other two decreased. These results indicated that producing foods containing grape seed or skin flours should avoid being baked at higher temperatures for long periods, and the microwave radiation process should be performed as quickly as possible, so that the phenolic ingredients in these foods are better retained.

The involvement of GABA-C receptors in paired-pulse depression of inhibitory postsynaptic currents in rat hippocampal CA1 pyramidal neurons

In rat hippocampal CA1 pyramidal neurons, gamma-aminobutyric acid (GABA) A receptor-mediated inhibitory postsynaptic currents (IPSCs) undergo a paired-pulse depression (PPD) by the second of two pulses, with inter-pulse intervals of 100-2000 ms, applied to the stratum radiatum. While GABA-C receptors are described in the CA1 area, their functional significance is unknown. In this study, the involvement of GABA-C receptors in PPD was examined using an in vitro hippocampal slice preparation. IPSCs evoked by stimulations in stratum radiatum were recorded with patch pipettes from CA1 pyramidal cells. PPD, when induced in the above fashion, was blocked by the GABA-C receptor antagonist (1,2,5,6-Tetrahydropyridin-4-yl) methylphosphinic acid (TPMPA, 10 muM, applied in the superfusing medium). GABA-A and GABA-B receptor-mediated IPSCs, as well as the baclofen-induced suppression of the GABA-A receptor mediated IPSC, were not antagonized by TPMPA (10-20 muM). These results indicate that PPD of the IPSC is mediated by the activation of GABA-C receptors.

An Improved Prognostic Parameter for Non-Hodgkin's Lymphoma Based on the Combination of Three Serum Tumor Markers

We aimed to evaluate the prognostic value of the combination of three serum tumor markers (LDH, β2-M and CA 125) in patients with non-Hodgkin's lymphoma (NHL). Clinical and pathological variables including the levels of these markers were measured in 415 NHL patients. Statistical analysis showed that increased levels of all three markers were associated with stage, B symptoms, effusions, bone marrow involvement, and International Prognostic Index (IPI) in NHL patients (p<0.05). Overall survival and event-free survival rates were associated not only with LDH but also with β2-M and CA125 (p<0.001). Response to treatment and overall survival rates were different in three groups with elevated LDH; in particular, the combination of three or two elevated markers seemed to identify a group of patients at higher risk of treatment failure and/or relapse than the group with a high LDH level only. Furthermore, multiple Cox regression analysis showed that IPI score complemented by the additional serum markers β2-M and CA125 was a better prognosticator of overall and event-free survival than LDH alone. This result suggests that if the combination of three elevated serum tumor markers is included as a parameter in the IPI instead of LDH alone, the prognostic value of IPI can be improved.

Effects of telomerase activity on carcinogenesis and survival in laryngeal carcinoma

This study aimed to look at whether a correlation exists between telomerase activity and survival of laryngeal carcinoma patients. Telomerase activity was measured by telomerase repeat amplification protocol in 31 laryngeal carcinomas and adjacent normal tissues, and in 21 vocal cord polyps (controls). Follow-up was for at least 60 months. Telomerase activity in tissues adjacent to laryngeal carcinomas was significantly higher than in the carcinomas which was, in turn, significantly higher than in vocal cord polyps. There was no significant difference between telomerase activity in carcinomas or adjacent tissues and clinicopathological characteristics. Patients with high telomerase activity in carcinoma tissue had significantly shorter survival times than those with low activity, but no significance difference was observed between survival time and telomerase status in adjacent tissues. Linear regression showed significant association between telomerase activity levels in carcinoma tissues and survival time, but this was not observed in adjacent tissues. This study suggests that telomerase activation probably takes place before the cancer phenotype develops and has prognostic significance for survival of patients with laryngeal carcinoma.

Influence of saliva contamination on zirconia ceramic bonding

OBJECTIVES

The purpose of this study was to investigate the influence of saliva contamination and cleaning methods on adhesive bonding to dental zirconia ceramic with a phosphate-monomer-containing luting resin.

METHODS

After saliva immersion, airborne-particle abraded ceramic specimens were cleaned with water rinsing, with isopropanol, with phosphoric acid gel, or with additional airborne-particle abrasion. Airborne-particle abraded specimens without contamination were used as the control group. Chemical analysis of the ceramic surfaces of all groups was done using X-ray photoelectron spectroscopy (XPS). The influence of contamination and cleaning methods on ceramic bond durability was examined by tensile bond strength (TBS) testing after 3 days or 150 days water storage with 37,500 thermal cycles.

RESULTS

After saliva contamination XPS revealed an organic coating which was not removed completely with water rinsing, with isopropanol, or with phosphoric acid. Using TBS testing a strong influence of contamination and cleaning methods on resin bond strength and its durability was found.

SIGNIFICANCE

Saliva contamination significantly affected resin bonds to zirconia ceramic and its durability. Airborne-particle abrasion was the most effective cleaning method.

Posterior fossa abscesses secondary to dermal sinus associated with dermoid cyst in children

We report on the rare disease of posterior fossa abscesses secondary to dermal sinus associated with dermoid cyst in 4 pediatric cases seen over a 15-year of period. All children had a small dimple or a pinhole on the skin of the occipital region. On admission they had the signs of increased intracranial pressure, while 3 of them still suffered from signs of meningitis resulting from a bacterial infection through the dermal sinus. CT scan and MR images revealed both the route of the dermal sinus and intracranial lesions. Total resection was successfully achieved before various treatments in all patients without nervous sequelae. In conclusion, a posterior fossa dermoid cyst should be considered in all children with an occipital dermal sinus. Cerebellar abscesses will arise once bacterial infection has occurred through the associated dermal sinus. Radiological studies such as CT scans and MR images can help confirm the diagnosis and locate the lesions. Early neurosurgical interventions including external ventricular drainage, external abscess drainage and primary removal should be planned as soon as possible in accord with the children's condition.