Immunostimulatory Effects of ��-glucan Purified from Paenibacillus polymyxa JB115 on Mouse Splenocytes

We investigated the effects of β-glucan purified from Paenibacillus polymyxa JB115 on the viability and proliferation of splenocytes. Splenocytes play a critical role in host immunity. MTT assays and trypan blue exclusion tests revealed that β-glucan significantly promoted the viability and proliferation of splenocytes over a range of concentrations. However, there was no specific subset change. β-glucan protected splenocytes from cytokine withdrawal-induced spontaneous cell death. For further mechanistic studies, ELISA assay revealed that β-glucan enhanced the expression of anti-apoptotic molecules and interleukin 7 (IL-7), a cytokine critical for lymphocyte survival. We also investigated the IL-2 dependency of β-glucan-treated splenocytes to determine if treated cells could still undergo clonal expansion. In flow cytometric analysis, β-glucan induced increased levels of the activation marker CD25 on the surface of splenocytes and β-glucan-treated splenocytes showed higher proliferation rates in response to IL-2 treatment. This study demonstrates that β-glucan can enhance the survival of splenocytes and provides valuable information to broaden the use of β-glucan in research fields.     

Blockade of Glutamate Receptors and Barbiturate Anesthesia: Increased Sensitivity to Pentobarbital-induced Anesthesia Despite Reduced Inhibition of AMPA Receptors in GluR2 Null Mutant Mice

Background: Barbiturates enhance [gamma]-aminobutyric acid type A (GABAA) receptor function and also inhibit the [alpha]-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) subtype of glutamate receptor. The relative contribution of these actions to the behavioral properties of barbiturates is not certain. Because AMPA receptor complexes that lack the GluR2 subunit are relatively insensitive to pentobarbital inhibition, GluR2 null mutant mice provide a novel tool to investigate the importance of AMPA receptor inhibition to the anesthetic effects of barbiturates.

Methods: GluR2 null allele (-/-), heterozygous (+/-), and wild-type (+/+) mice were injected with pentobarbital (30 and 35 mg/kg intraperitoneally). Sensitivity to anesthetics was assessed by measuring the latency to loss of righting reflex, sleep time, and the loss of corneal, pineal, and toe-pinch withdrawal reflexes. In addition, patch-clamp recordings of acutely dissociated CA1 hippocampal pyramidal neurons from (-/-) and (+/+) mice were undertaken to investigate the effects of barbiturates on kainate-activated AMPA receptors and GABA-activated GABAA receptors.

Results: Behavioral tests indicate that sensitivity to pentobarbital was increased in (-/-) mice. In contrast, AMPA receptors from (-/-) neurons were less sensitive to inhibition by pentobarbital (concentrations that produced 50% of the maximal inhibition [IC50], 301 vs. 51 [mu]M), thiopental (IC50, 153 vs. 34 [mu]M), and phenobarbital (IC50, 930 vs. 205 [mu]M) compared with wild-type controls, respectively. In addition, the potency of kainate was greater in (-/-) neurons, whereas no differences were observed for the potentiation of GABAA receptors by pentobarbital.     

The Clinical Utility of a Adding Lateral Approach to Conventional Vertical Approach for Prone Stereotactic Vacuum-Assisted Breast Biopsy

Objective

The purpose of this study is to evaluate the clinical utility of adding lateral approach to conventional vertical approach for prone stereotactic vacuum-assisted breast biopsies.

Materials and Methods

From April 2010 to May 2012, 130 vacuum-assisted stereotactic biopsies were attempted in 127 patients. While a vertical approach was preferred, a lateral approach was used if the vertical approach failed. The success rate of biopsies utilizing only a vertical approach was compared with that using both vertical and lateral approaches and the breast thickness for both procedures was measured and compared with that for vertical approach. In addition, pathology results were evaluated and the causes of the failed biopsies were analyzed.

Results

Of the 130 cases, 127 biopsies were performed and 3 biopsies failed. The success rate of the vertical approach was 83.8% (109/130); however, when the lateral approach was also used, the success rate increased to 97.7% (127/130) (p = 0.0004). The mean breast thickness was 2.7 ± 1 cm for the lateral approach and 4 ± 1.2 cm for the vertical approach (p < 0.0001). The histopathologic results in 76 (59.8%) of the biopsies were benign, 23 (18.1%) were high-risk lesions, and 28 (22.0%) were malignant. The causes of biopsy failure were thin breasts (n = 2) and undetected difficult lesion location (n = 1).

Conclusion

The addition of lateral approach to conventional vertical approach in prone stereotactic vacuum-assisted breast biopsy improved the success rate of stereotactic biopsy, especially in patients with thin breasts.