Behavioral Effects of Deep Brain Stimulation of the Anterior Nucleus of Thalamus,Entorhinal Cortex and Fornix in a Rat Model of Alzheimer's Disease

Background:

Recent clinical and preclinical studies have suggested that deep brain stimulation (DBS) can be used as a tool to enhance cognitive functions. The aim of the present study was to investigate the impact of DBS at three separate targets in the Papez circuit, including the anterior nucleus of thalamus (ANT), the entorhinal cortex (EC), and the fornix (FX), on cognitive behaviors in an Alzheimer''s disease (AD) rat model.

Methods:

Forty-eight rats were subjected to an intrahippocampal injection of amyloid peptides 1-42 to induce an AD model. Rats were divided into six groups: DBS and sham DBS groups of ANT, EC, and FX. Spatial learning and memory were assessed by the Morris water maze (MWM). Recognition memory was investigated by the novel object recognition memory test (NORM). Locomotor and anxiety-related behaviors were detected by the open field test (OF). By using two-way analysis of variance (ANOVA), behavior differences between the six groups were analyzed.

Results:

In the MWM, the ANT, EC, and FX DBS groups performed differently in terms of the time spent in the platform zone (F_(2,23) = 6.04, P < 0.01), the frequency of platform crossing (F_(2,23) = 11.53, P < 0.001), and the percent time spent within the platform quadrant (F_(2,23) = 6.29, P < 0.01). In the NORM, the EC and FX DBS groups spent more time with the novel object, although the ANT DBS group did not (F_(2,23) = 10.03, P < 0.001). In the OF, all of the groups showed a similar total distance moved (F_(1,42) = 1.14, P = 0.29) and relative time spent in the center (F_(2,42) = 0.56, P = 0.58).

Conclusions:

Our results demonstrated that DBS of the EC and FX facilitated hippocampus-dependent spatial memory more prominently than ANT DBS. In addition, hippocampus-independent recognition memory was enhanced by EC and FX DBS. None of the targets showed side-effects of anxiety or locomotor behaviors.     

A novel method to identify and isolate proliferative inflammatory atrophy (PIA) clusters and to extract high-quality PIA RNA

Epidemiological and histopathological studies have indicated that proliferative inflammatory atrophy (PIA) of the prostate is closely associated with the onset and development of prostate cancer (PCa). However, accurate isolation of PIA still remains a difficult matter, as well as high-quality RNA extraction from isolated PIA. These issues generated a lack of molecular evidence to support the mechanistic explanation proposed for the progression of PIA to PCa. Therefore, the isolation of PIA and the extraction of high-quality RNA from isolated PIA are of great importance to further demonstrate the correlation between PIA and the development of PCa at a molecular level. In this study, clinical samples from radical prostatectomy were stored in liquid nitrogen, PIA was identified by H&E staining of cryosections, PIA clusters were isolated by manual microdissection, total RNA was extracted from the PIA clusters by Trizol, and RNA quality was determined using the Agilent 2100 Bioanalyzer. Our results showed that PIA might be isolated by manual microdissection of cryosections stored in liquid nitrogen from clinical radical prostatectomy and used for extracting high-quality RNA (RIN > 7.5) by Trizol. Therefore, the present study established a valid method to discover molecular evidence in support of the correlation between PIA and the development of PCa.     

High miR-196a and low miR-367 cooperatively correlate with unfavorable prognosis of high-grade glioma

Identification of microRNAs (miRNAs) could be beneficial for the diagnosis and prognosis of glioma. Therefore, we attempted to identify and develop specific miRNAs as prognostic and predictive markers for glioma patients. We compared the expression profiles of 365 miRNAs between 4 glioblastomas (GBMs, WHO grade IV) and 4 anaplastic astrocytomas (AAs, WHO grade III) using miRNA qPCR Array. MiR-196a (P = 0.004, fold change = 289.86) and miR-367 (P = 0.044, fold change = 0.03) were identified as the most up-regulated and down-regulated miRNAs in GBMs compared with AAs, respectively. We subsequently examined miR-196a and miR-367 expression levels in an independent series of 63 gliomas including 50 GBMs and 13 AAs, as well as 10 non-neoplastic brain tissues, and statistically analyzed the associations between miRNA expression and clinicopathological characteristics and survivals of these glioma patients. MiR-196a and miR-367 showed significant increased and decreased expression in high-grade gliomas relative to non-neoplastic brains, as well as in GBMs versus AAs, respectively. Additionally, high-miR-196a and low-miR-367 expression, alone or in combination, statistically correlated with aggressive clinicopathological features of gliomas. Furthermore, overall survivals of glioma patients with high-miR-196a, low-miR-367 and high-miR-196a/low-miR-367 expression tended to be shorter than the corresponding control groups (all P ≤ 0.001). Moreover, multivariate analysis indicated high-miR-196a/low-miR-367 as an independent prognostic indicator for glioma patients (P = 0.005, risk ratio = 1.8). Our results suggested that both high-miR-196a and low-miR-367 expression may be associated with aggressive progression and unfavorable clinical outcome in glioma patients. And combination of high-miR-196a and low-miR-367 expression may be a novel biomarker in identifying a poor prognosis group of high-grade glioma.     

Comparison of total hip and knee joint replacement in patients with rheumatoid arthritis and osteoarthritis: a nationwide,population-based study

INTRODUCTION

Patients with rheumatoid arthritis (RA) and osteoarthritis (OA) may require total hip replacement (THR) or total knee replacement (TKR). The present study aimed to compare the demographic characteristics and medical costs of RA and OA patients from Taiwan who underwent either THR or TKR.

METHODS

The medical records of patients who had undergone THR or TKR from 1 January 1996 to 31 December 2010 were obtained from the Taiwan National Health Insurance Research Database (NHIRD). In all, we found 49 and 146 RA patients who received THR and TKR, respectively, and 1,191 and 6,574 OA patients who received THR and TKR, respectively. The gender, age, Charlson comorbidity index (CCI), hospital grade, age at registration in the catastrophic illness dataset, and medical utilisation costs of the different groups were compared.

RESULTS

There were statistically significant differences in age, CCI score, drug costs and surgery costs between RA and OA patients. Joint replacement incidence was lower in RA patients than in OA patients, and among patients who underwent THR, total medical costs incurred were higher for RA patients than OA patients. RA patients who underwent THR incurred a significantly greater total medical utilisation cost in the outpatient department (3 months before surgery and 12 months after surgery) than OA patients who underwent THR.

CONCLUSION

Analysis of Taiwan NHIRD with regard to patients who had undergone either THR or TKR indicated that RA patients were younger than OA patients, and that significantly more medical resources were used for RA patients before, during and after hospitalisation for these procedures.     

Posterior compensatory network in cognitively intact elders with hippocampal atrophy

Functional compensation in late life is poorly understood but may be vital to understanding long‐term cognitive trajectories. To study this we first established an empirically derived threshold to distinguish hippocampal atrophy in those with Mild Cognitive Impairment (MCI n = 34) from those with proficient cognition (PRO n = 22), using data from a population‐based cohort. Next, to identify compensatory networks we compared cortical activity patterns during a graded spatial working memory (SWM) task in only cognitively proficient individuals, either with (PRO_ATR) or without hippocampal atrophy (PRO_NIL). Multivariate Partial Least Squares analyses revealed that these groups engaged spatially distinct SWM‐related networks. In those with hippocampal atrophy and under conditions of basic‐SWM demand, expression of a posterior compensatory network (PCN) comprised calcarine and posterior parietal cortex strongly correlated with superior SWM performance (r = −0.96). In these individuals, basic level SWM response times were faster and no less accurate than in those with no hippocampal atrophy. Cognitively proficient older individuals with hippocampal atrophy may, therefore, uniquely engage posterior brain areas when performing simple spatial working memory tasks. © 2014 Wiley Periodicals, Inc.     

Osteomyelitis of multiple lumbar vertebrae associated with infected aortic aneurysm: a case report

A 73-year-old male patient presented with a pulsating abdominal mass and intractable low back pain for several days. Magnetic resonance imaging revealed an infected abdominal aortic aneurysm invading the second, third, and fourth lumbar vertebrae. He underwent radical debridement of the infected aneurysm with reconstruction using vascular bypass, partial corpectomy of the L2 to L4 vertebrae, anterior reconstruction with autogenous fibular shaft, and posterior instrumentation with posterolateral fusion. Culture of the necrotic tissues grew oxacillin-resistant Staphylococcus aureus. He received intravenous vancomycin infusion for 4 weeks and oral ciprofloxacin for 6 months postoperatively. After a 15-month follow-up, no apparent signs of further infection were noted. C-reactive protein and erythrocyte sedimentation rate returned to normal during follow-up. No neurologic symptoms other than mild low back soreness were noted. The stability of the lumbar spine was maintained using long segment reconstruction with autogenous fibula shaft and posterior instrumentation along with posterolateral fusion. Infected aortic aneurysm with vertebral osteomyelitis is a rare clinical entity. Prompt diagnosis and adequate treatment are essential.