Comparative Analysis of Endoscope Obscuration With Utilization of an Endonasal Access Guide for Endonasal Skull Base Surgery.

BACKGROUND AND OBJECTIVES: In endoscopic endonasal approaches (EEAs) for skull base pathologies, endoscope view obscuration remains a persistent, time-consuming, and distracting issue for surgeons and may result in increased operative time. The endonasal access guide (EAG) has been demonstrated as a possible adjunct to minimize these events. However, to date, there have been no comparative studies performed and the potential time savings by using EAGs have yet to be quantified. This cohort study aimed to determine the operative efficiency benefits of the EAG in EEA operations. METHODS: Analysis of EEA operative videos from an EAG cohort (n = 20) and a control cohort (n = 20) was performed, assessing 12-minute segments in the first, middle, and last third of each operation. The first segment in each cohort was selected before EAG placement, serving as an internal control. Every endoscope lens soiling instance was counted (measured as cleaning actions per minute), timed (obscuration time %), and identified as a withdrawal, irrigation, or other cleaning action. Perioperative variables including skull base repair and postoperative cerebrospinal fluid leakage were assessed. RESULTS: Within the EAG cohort, obscuration time was reduced in the middle and last third compared with the first third (3.73% [CI: 2.39-5.07] vs 12.97% [CI: 10.24-15.70], P < .001; 4.19% [CI: 2.83-5.55] vs 12.97% [CI: 10.24-15.70], P < .001) and cleaning actions were also significantly reduced by EAG (0.69/min [CI: 0.39-0.99] vs 1.67/min [CI: 1.34-2.00], P = .001; 0.66/min [CI: 0.35-0.97] vs 1.67/min [CI: 1.34-2.00], P < .001). Between the control and EAG cohorts, there was no significant difference between obscuration time and cleaning actions in the first third (9.33% vs 12.97%, P = .086; 1.34/min vs 1.67/min, P = .151) or in the middle third (6.24% vs 3.73%, P = .140; 0.80/min vs 0.69/min, P = .335), but there was a significant difference in the last third (9.25% [CI: 6.95-11.55] vs 4.19% [CI: 2.83-5.55], P < .001; 0.95/min [CI: 0.73-1.17] vs 0.66/min [CI: 0.35-0.97], P = .018). CONCLUSION: EAG significantly reduces lens obscurations and cleaning events, particularly during the intradural portion of operations. This technology may offer a greater time-saving impact with patients undergoing long EEA operations.

Antigen presenting cell response to polysaccharide A is characterized by the generation of anti-inflammatory macrophages.

Polysaccharide A (PSA) is the immunodominant capsular carbohydrate from the gram negative commensal microbe Bacteroides fragilis that has shown remarkable potency in ameliorating many rodent models of inflammatory disease by eliciting downstream suppressive CD4+ T cells. PSA is composed of a zwitterionic repeating unit that allows it to be processed by antigen presenting cells (APCs) and presented by MHCII in a glycosylation-dependent manner. While previous work has uncovered much about the interactions between MHCII and PSA, as well as the downstream T cell response, little is known about how PSA affects the phenotype of MHCII+ APCs, including macrophages. Here, we utilized an unbiased systems approach consisting of RNAseq transcriptomics, high-throughput flow cytometry, Luminex analysis and targeted validation experiments to characterize the impact of PSA-mediated stimulation of splenic MHCII+ cells. The data revealed that PSA potently elicited the upregulation of an alternatively activated M2 macrophage transcriptomic and cell surface signature. Cell-type-specific validation experiments further demonstrated that PSA-exposed bone marrow-derived macrophages (BMDMs) induced cell surface and intracellular markers associated with M2 macrophages compared with conventional peptide ovalbumin (ova)-exposed BMDMs. In contrast to macrophages, we also found that CD11c+ dendritic cells (DCs) upregulated the pro-T cell activation costimulatory molecule CD86 following PSA stimulation. Consistent with the divergent BMDM and DC changes, PSA-exposed DCs elicited an antigen-experienced T cell phenotype in co-cultures, whereas macrophages did not. These findings collectively demonstrate that the PSA-induced immune response is characterized by both T cell stimulation via presentation by DCs, and a previously unrecognized anti-inflammatory polarization of macrophages.

Vitamin D Receptor Protects Against Dysbiosis and Tumorigenesis via the JAK/STAT Pathway in Intestine.

BACKGROUND & AIMS: Vitamin D exerts regulatory roles via vitamin D receptor (VDR) in mucosal immunity, host defense, and inflammation involving host factors and microbiome. Human Vdr gene variation shapes the microbiome and VDR deletion leads to dysbiosis. Low VDR expression and diminished vitamin D/VDR signaling are observed in colon cancer. Nevertheless, how intestinal epithelial VDR is involved in tumorigenesis through gut microbiota remains unknown. We hypothesized that intestinal VDR protects mice against dysbiosis via modulating the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway in tumorigenesis. METHODS: To test our hypothesis, we used an azoxymethane/dextran sulfate sodium-induced cancer model in intestinal VDR conditional knockout (VDRΔIEC) mice, cell cultures, stem cell-derived colonoids, and human colon cancer samples. RESULTS: VDRΔIEC mice have higher numbers of tumors, with the location shifted from the distal to proximal colon. Fecal microbiota analysis showed that VDR deletion leads to a bacterial profile shift from normal to susceptible carcinogenesis. We found enhanced bacterial staining in mouse and human tumors. Microbial metabolites from VDRΔIEC mice showed increased secondary bile acids, consistent with observations in human CRC. We further identified that VDR protein bound to the Jak2 promoter, suggesting that VDR transcriptionally regulated Jak2. The JAK/STAT pathway is critical in intestinal and microbial homeostasis. Fecal samples from VDRΔIEC mice activate the STAT3 signaling in human and mouse organoids. Lack of VDR led to hyperfunction of Jak2 in response to intestinal dysbiosis. A JAK/STAT inhibitor abolished the microbiome-induced activation of STAT3. CONCLUSIONS: We provide insights into the mechanism of VDR dysfunction leading to dysbiosis and tumorigenesis. It indicates a new target: microbiome and VDR for the prevention of cancer.

Correcting an instance of synthetic lethality with a pro-survival sequence.

A human cDNA encoding the LIM domain containing 194 amino acid cysteine and glycine rich protein 3 (CSRP3) was identified as a BAX suppressor in yeast and a pro-survival sequence that abrogated copper mediated regulated cell death (RCD). Yeast lacks a CSRP3 orthologue but it has four LIM sequences, namely RGA1, RGA2, LRG1 and PXL1. These are known regulators of stress responses yet their roles in RCD remain unknown. Given that LIMs interact with other LIMs, we ruled out the possibility that overexpressed yeast LIMs alone could prevent RCD and that CSRP3 functions by acting as a dominant regulator of yeast LIMs. Of interest was the discovery that even though yeast cells lacking the LIM encoding PXL1 had no overt growth defect, it was nevertheless supersensitive to the effects of sublethal levels of copper. Heterologous expression of human CSPR3 as well as the pro-survival 14-3-3 sequence corrected this copper supersensitivity. These results show that the pxl1∆-copper synthetic lethality is likely due to the induction of RCD. This differs from the prevailing model in which synthetic lethality occurs because of specific defects generated by the combined loss of two overlapping but non-essential functions.

Automated tracking of level of consciousness and delirium in critical illness using deep learning.

Over- and under-sedation are common in the ICU, and contribute to poor ICU outcomes including delirium. Behavioral assessments, such as Richmond Agitation-Sedation Scale (RASS) for monitoring levels of sedation and Confusion Assessment Method for the ICU (CAM-ICU) for detecting signs of delirium, are often used. As an alternative, brain monitoring with electroencephalography (EEG) has been proposed in the operating room, but is challenging to implement in ICU due to the differences between critical illness and elective surgery, as well as the duration of sedation. Here we present a deep learning model based on a combination of convolutional and recurrent neural networks that automatically tracks both the level of consciousness and delirium using frontal EEG signals in the ICU. For level of consciousness, the system achieves a median accuracy of 70% when allowing prediction to be within one RASS level difference across all patients, which is comparable or higher than the median technician-nurse agreement at 59%. For delirium, the system achieves an AUC of 0.80 with 69% sensitivity and 83% specificity at the optimal operating point. The results show it is feasible to continuously track level of consciousness and delirium in the ICU.

Lack of Vitamin D Receptor Leads to Hyperfunction of Claudin-2 in Intestinal Inflammatory Responses.

Background: Vitamin D3 and vitamin D receptor (VDR) are involved in the pathogenesis of inflammatory bowel disease (IBD) and bacterial infection. Claudin-2 is a junction protein that mediates paracellular water transport in epithelia. Elevation of Claudin-2 is associated with active IBD. However, VDR involved in epithelial junctions under inflammation and infection remains largely unknown. We investigated the mechanisms on how VDR and Claudin-2 are related in inflamed states. Methods: Using cultured VDR-/- enteroids, human intestinal epithelial cells, VDR-/- mice with Salmonella- or DSS-colitis, and human IBD samples, we investigated the mechanisms how VDR and Claudin-2 are related in inflamed states. Results: After Salmonella infection had taken place, we observed significantly enhanced Claudin-2 and an increased bacterial invasion and translocation. A lack of VDR regulation led to a robust increase of Claudin-2 at the mRNA and protein levels post-infection. In DSS-treated VDR-/- mice, Claudin-2 was significantly increased. Location and quantification of Claudin-2 protein in the mouse colons treated with DSS also confirmed these results. Inflammatory cytokines were significantly higher in the serum and mRNA levels in intestine, which are known to increase Claudin-2. Furthermore, in inflamed intestine of ulcerative colitis patients, VDR expression was low and Claudin-2 was enhanced. Mechanistically, we identified the enhanced Claudin-2 promoter activity through the binding sites of NF-κB and STAT in inflamed VDR-/- cells. Conclusions: Our studies have identified a new role for intestinal epithelial VDR in regulating barrier functions in the context of infection and inflammation.

Heterologous expression of anti-apoptotic human 14-3-3ß/α enhances iron-mediated programmed cell death in yeast.

The induction of Programmed Cell Death (PCD) requires the activation of complex responses involving the interplay of a variety of different cellular proteins, pathways, and processes. Uncovering the mechanisms regulating PCD requires an understanding of the different processes that both positively and negatively regulate cell death. Here we have examined the response of normal as well as PCD resistant yeast cells to different PCD inducing stresses. As expected cells expressing the pro-survival human 14-3-3ß/α sequence show increased resistance to numerous stresses including copper and rapamycin. In contrast, other stresses including iron were more lethal in PCD resistant 14-3-3ß/α expressing cells. The increased sensitivity to PCD was not iron and 14-3-3ß/α specific since it was also observed with other stresses (hydroxyurea and zinc) and other pro-survival sequences (human TC-1 and H-ferritin). Although microscopical examination revealed little differences in morphology with iron or copper stresses, cells undergoing PCD in response to high levels of prolonged copper treatment were reduced in size. This supports the interaction some forms of PCD have with the mechanisms regulating cell growth. Analysis of iron-mediated effects in yeast mutant strains lacking key regulators suggests that a functional vacuole is required to mediate the synergistic effects of iron and 14-3-3ß/α on yeast PCD. Finally, mild sub-lethal levels of copper were found to attenuate the observed inhibitory effects of iron. Taken together, we propose a model in which a subset of stresses like iron induces a complex process that requires the cross-talk of two different PCD inducing pathways.

Membranous staining of ß-catenin and E-cadherin expression in patients with gastric cancer.

BACKGROUND: ß-catenin and E-cadherin are adhesion molecules that promote metastatic potential through epithelial-mesenchymal transition (EMT). Although they have not been extensively studied in gastric cancers, they represent potential testable prognostic markers. METHODS: We explored the association between the immunohistochemical expression of these markers and clinicopathologic parameters by retrospectively reviewing 205 cases of gastric cancer from tissue microarrays (TMA). A method was developed to evaluate for membranous staining of ß-catenin and E-cadherin using grading criteria that characterized both the intensity of staining and the percentage of cells with loss of staining. RESULTS: Weak membranous expression of E-cadherin and ß-catenin were associated with worse overall survival (p<0.05). Abnormal expression of E-cadherin and ß-catenin were significantly associated with each other (p<0.01). Loss of and/or weak membranous staining for both E-cadherin and ß-catenin was significantly associated with advanced cancer stage T2-T4 (versus stage T1, p<0.05) and tumors that are negative for H pylori infection (p<0.05). In addition, loss of and/or weak membranous staining for ß-catenin was significantly associated with poorly differentiated tumors (p<0.05), diffuse Lauren-type gastric tissue (p=0.02), and tumors with a significantly higher rate of lymphovascular invasion (p=0.02). CONCLUSION: Loss of/weak membranous expression of both E-cadherin and ß-catenin was associated with poorer overall survival rates and clinicopathologic parameters that indicated an aggressive clinical behavior. ß-catenin shows significant associations with more clinical parameters, making it a better biomarker than E-cadherin. In our multivariate analysis, weak intensity of staining of ß-catenin was an independent prognostic factor for survival and may be a useful immunohistochemical prognostic marker for patients with gastric cancer.

A rare case of anal carcinosarcoma with human papilloma virus infection in both biphasic tumor elements: An immunohistochemical, molecular and ultrastructural study.

Carcinosarcoma of the anus is rare and has yet to be reportedly associated with the keratinocyte-specific Human Papilloma Virus (HPV). We describe a case of anal carcinosarcoma with HPV infection in both the epithelial and mesenchymal components of the tumor by immunohistochemistry, chromogenic in-situ hybridization (CISH) and further supported by electron microscopy (EM). Microscopic examination of the tumor showed nests of poorly-differentiated invasive squamous cell carcinoma with basaloid features intermixed with a hypercellular, atypical spindle cell proliferation. Immunohistochemistry demonstrated that the epithelial component was positive for AE1/AE3, p63, CK5/6 and p16, whilst the mesenchymal component was positive for smooth muscle actin, vimentin, and focally positive for desmin and p16, consistent with carcinosarcoma. The tumor was negative for GATA-3, CK7 and CK20. CISH demonstrated that the tumor was positive for high risk HPV (subtype 16/18) in both tumor components. EM further supported the presence of intracellular virus particles (~50 nm) that is compatible with HPV infection. Infection of both epithelial and mesenchymal tumor components by HPV has not been previously observed in the gastrointestinal tract. This finding may represent initial epithelial HPV infection with subsequent divergent tumoral differentiation and suggests the presence of viral replication in both biphasic tumor components.

Clinical impact of tumor-infiltrating inflammatory cells in primary small cell esophageal carcinoma.

Primary small cell esophageal carcinoma is a rare and aggressive type of gastrointestinal cancer with poor prognosis. In the present study, the impact of tumour infiltrating inflammatory cells on clinico-pathological characteristics and the patients' prognosis were analysed. A total of 36 small cell esophageal carcinomas, 19 adjacent normal tissues and 16 esophageal squamous cell carcinoma samples were collected. Qualified pathologists examined eosinophils, neutrophils, lymphocytes and macrophages on histochemical slides. The infiltration of eosinophils and macrophages in small cell esophageal carcinoma was significantly increased as compared with tumor adjacent normal tissues, and was significantly less in esophageal squamous cell carcinoma. Macrophage count was significantly associated with (p = 0.015) lymph node-stage in small cell esophageal carcinoma. When we grouped patients into two groups by counts of infiltrated inflammatory cells, Kaplan-Meier analysis revealed that high macrophage infiltration group (p = 0.004) and high eosinophil infiltration group (p = 0.027) had significantly enhanced survival. In addition, multivariate analysis unveiled that eosinophil count (p = 0.002) and chemotherapy (Yes vs. No, p = 0.001) were independent prognostic indicators. Taken together, infiltration of macrophages and eosinophils into the solid tumor appear to be important in the progression of small cell esophageal carcinoma and patients' prognosis.

Prognostic importance and therapeutic implications of PAK1, a drugable protein kinase, in gastroesophageal junction adenocarcinoma.

Gastroesophageal junction (GEJ) adenocarcinoma is a lethal cancer with rising incidence, yet the molecular biomarkers that have strong prognostic impact and also hold great therapeutic promise remain elusive. We used a data mining approach and identified the p21 protein-activated kinase 1 (PAK1), an oncogene and drugable protein kinase, to be among the most promising targets for GEJ adenocarcinoma. Immunoblot analysis and data mining demonstrated that PAK1 protein and mRNA were upregulated in cancer tissues compared to the noncancerous tissues. Immunohistochemistry revealed PAK1 overexpression in 72.6% of primary GEJ adenocarcinomas (n = 113). A step-wise increase in PAK1 levels was noted from paired normal epithelium, to atypical hyperplasia and adenocarcinoma. PAK1 overexpression in tumor was associated with lymph node (LN) metastasis (P<0.001), advanced tumor stage (P<0.001), large tumor size (P = 0.006), residual surgical margin (P = 0.033), and unfavorable overall survival (P<0.001). Multivariate analysis showed PAK1 overexpression is an independent high-risk prognostic predictor (P<0.001). Collectively, PAK1 is overexpressed during tumorigenic progression and its upregulation correlates with malignant properties mainly relevant to invasion and metastasis. PAK1 expression could serve as a prognostic predictor that holds therapeutic promise for GEJ adenocarcinoma.

In situ kinase profiling reveals functionally relevant properties of native kinases.

Protein kinases are intensely studied mediators of cellular signaling, yet important questions remain regarding their regulation and in vivo properties. Here, we use a probe-based chemoprotemics platform to profile several well studied kinase inhibitors against >200 kinases in native cell proteomes and reveal biological targets for some of these inhibitors. Several striking differences were identified between native and recombinant kinase inhibitory profiles, in particular, for the Raf kinases. The native kinase binding profiles presented here closely mirror the cellular activity of these inhibitors, even when the inhibition profiles differ dramatically from recombinant assay results. Additionally, Raf activation events could be detected on live cell treatment with inhibitors. These studies highlight the complexities of protein kinase behavior in the cellular context and demonstrate that profiling with only recombinant/purified enzymes can be misleading.

A phase III randomized trial of the timing of meloxicam with iodine-125 prostate brachytherapy.

PURPOSE: Nonsteroidal anti-inflammatory medication is used to reduce prostate edema and urinary symptoms following prostate brachytherapy. We hypothesized that a cyclooxygenase-2 (COX-2) inhibitor regimen started 1 week prior to seed implant might diminish the inflammatory response, thus reducing edema, retention rates, and symptom severity. METHODS AND MATERIALS: From March 2004 to February 2008, 316 men consented to an institutional review board-approved randomized study of a 4-week course of meloxicam, 7.5 mg orally twice per day, starting either on the day of implant or 1 week prior to implant. Brachytherapy was performed using iodine-125 seeds and was preplanned and performed under transrectal ultrasound (TRUS) and fluoroscopic guidance. Prostate volume obtained by MR imaging at 1 month was compared to baseline prostate volume obtained by TRUS planimetry and expressed as an edema factor. The trial endpoints were prostate edema at 1 month, International Prostate Symptom Score (IPSS) questionnaire results at 1 and 3 months, and any need for catheterization. RESULTS: Results for 300 men were analyzed. Median age was 61 (range, 45-79 years), and median TRUS prostate volume was 35.7 cc (range, 18.1-69.5 cc). Median IPSS at baseline was 5 (range, 0-24) and was 15 at 1 month, 16 at 3 months, and 10 at 6 months. Catheterization was required for 7% of patients (6.2% day 0 arm vs. 7.9% day -7 arm; p = 0.65). The median edema factor at 1 month was 1.02 (range, 0.73-1.7). 1.01 day 0 arm vs. 1.05 day -7 arm. Baseline prostate volume remained the primary predictor of postimplant urinary retention. CONCLUSIONS: Starting meloxicam 1 week prior to brachytherapy compared to starting immediately after the procedure did not reduce 1-month edema, improve IPSSs at 1 or 3 months, or reduce the need for catheterization.

Are endoscopic therapies appropriate for superficial submucosal esophageal adenocarcinoma? An analysis of esophagectomy specimens.

BACKGROUND: Endoscopic resection and ablation have advanced the treatment of intramucosal esophageal adenocarcinoma and have been promoted as definitive therapy for selected superficial submucosal tumors. Controversy exists regarding the prevalence of nodal metastases at various depths of mucosal and submucosal invasion. Our aim was to clarify this prevalence and identify predictors of nodal spread. STUDY DESIGN: An expert gastrointestinal pathologist retrospectively reviewed 54 T1 adenocarcinomas from 258 esophagectomy specimens (2000 to 2008). Tumors were classified as intramucosal or submucosal, the latter being subclassified as SM1 (upper third), SM2 (middle third), or SM3 (lower third) based on the depth of tumor invasion. The depth of invasion was correlated with the prevalence of positive nodes. Fisher's exact test and univariate and multivariate logistic regression were used to identify variables predicting nodal disease. RESULTS: Nodal metastases were present in 0% (0 of 25) of intramucosal, 21% (3 of 14) of SM1, 36% (4 of 11) of SM2, and 50% (2 of 4) of SM3 tumors. The differences were significant between intramucosal and submucosal tumors (p < 0.0001), although not between the various subclassifications of submucosal tumors (p = 0.503). Univariate logistic regression identified poor differentiation (p = 0.024), lymphovascular invasion (p = 0.049), and number of harvested lymph nodes (p = 0.037) as significantly correlated with nodal disease. Multivariate logistic regression did not identify any of the tested variables as independent predictors of the prevalence of positive lymph nodes. CONCLUSIONS: All depths of submucosal invasion of esophageal adenocarcinoma were associated with an unacceptably high prevalence of nodal metastases and a marked increase relative to intramucosal cancer. Accurate predictors of nodal spread, independent of tumor depth, are currently lacking and will be necessary before recommending endoscopic resection with or without concomitant ablation as curative treatment for even superficial submucosal neoplasia.

Relationship between mitochondrial DNA mutations and clinical characteristics in human lung cancer.

Mitochondrial DNA (mtDNA) is known for its high frequencies of polymorphisms and mutations, some of which are related to various diseases, including cancers. However, roles of mutations and polymorphisms in some diseases are among heated debate, especially for cancer. To investigate the possible role of mtDNA mutations in lung cancer, we sequenced complete mtDNA of lung cancer tissues, corresponding normal (i.e., non-cancerous) lung tissues, and peripheral blood samples from 55 lung cancer patients and examined the relationship between mtDNA mutations or polymorphisms and clinical parameters. We identified 56 mutations in 33 (60%) of the 55 patients, including 48 point mutations, four single-nucleotide insertions, and four single-nucleotide deletions. Nineteen of these mutations resulted in amino acid substitution. These missense mtDNA mutations were distributed in 9 of 13 mitochondrial DNA coding genes. Three hundred eighty eight polymorphisms were identified among the 55 patients. Seventy-three polymorphisms resulted in amino acid substitution. There was no association of incidence of specific mtDNA mutation or polymorphism with patients' gender, age at diagnosis, smoking history, tumor type or tumor stage (P>0.05). This study revealed a variety of mtDNA mutations and mtDNA polymorphisms in human lung cancer, some of which might be involved in human lung carcinogenesis.

A 2-year follow-up study of alcohol consumption and risk of dementia.

BACKGROUND: This report focused on investigating the relationship between alcohol consumption and dementia in elderly people through prospective studies. METHODS: We conducted a 2-year follow-up study of elderly people from six communities in Chongqing, China. Dementia was detected using the Mini-Mental State Examination (MMSE) and the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R). The relationship between alcohol consumption and dementia was investigated using multiple logistic regression models, adjusting for the potential confounders age, sex, educational level and cigarette smoking. RESULTS: Light-to-moderate drinking was associated with a significantly lower risk of dementia compared with non-drinking. Excessive drinking was related to a higher risk of dementia. The effect of light-to-moderate drinking seemed most prominent among vascular dementia, 0.63 (0.55-0.72) for Alzheimer's disease, 0.31 (0.19-0.51) for vascular dementia and 0.45 (0.12-1.69) for other dementia. In a model adjusting for confounding variables, a light-to-moderate intake of beer was associated with a significantly higher risk of dementia than a non-drinker of beer. For wine, a significantly lower risk of dementia existed for a light-to-moderate drinker. CONCLUSIONS: Light-to-moderate drinking was associated with a significantly lower risk of dementia compared with a non-drinker.

Effects of titanium particle size on osteoblast functions in vitro and in vivo.

The formation of titanium (Ti)-wear particles during the lifetime of an implant is believed to be a major component of loosening due to debris-induced changes in bone cell function. Radiographic evidence indicates a loss of fixation at the implant-bone interface, and we believe that the accumulation of Ti particles may act on the bone-remodeling process and impact both long- and short-term implant-fixation strengths. To determine the effects of various sizes of the Ti particles on osteoblast function in vivo, we measured the loss of integration strength around Ti-pin implants inserted into a rat tibia in conjunction with Ti particles from one of four size-groups. Implant integration is mediated primarily by osteoblast adhesion/focal contact pattern, viability, proliferation and differentiation, and osteoclast recruitment at the implant site in vivo. This study demonstrates the significant attenuation of osteoblast function concurrent with increased expression of receptor activator of nuclear factor kappaB ligand (RANKL), a dominant signal for osteoclast recruitment, which is regulated differentially, depending on the size of the Ti particle. Zymography studies have also demonstrated increased activities of matrix metalloproteinases (MMP) 2 and 9 in cells exposed to larger Ti particles. In summary, all particles have adverse effects on osteoblast function, resulting in decreased bone formation and integration, but different mechanisms are elicited by particles of different sizes.

Peripheral blood mononuclear cell production of TNF-alpha in response to North American ginseng stimulation.

North American ginseng (Panax quinquefolium) root extract (NAGE) with known ginsenosides composition was examined for its affinity to stimulate human tumour necrosis factor alpha (TNF-alpha) production in human peripheral blood mononuclear cells. Case studies were conducted in three donors, one that was diagnosed with an atopic allergy and two that were normal, healthy subjects. Cultured mononuclear cells were incubated with varying concentrations of NAGE for up to 72 h and culture media were tested for TNF-alpha concentration. Direct stimulation of mononuclear cell TNF-alpha production in vitro by NAGE occurred as early as 6 h with 200 microg NAGE/mL. The stimulation of TNF-alpha production was confirmed by TNF-alpha mRNA gene expression. These interesting results show the immunostimulating activity of NAGE components in reference to TNF-alpha production. This observation requires further investigation with more subjects to determine the affinity of ginseng in stimulating the human immune system. Moreover, the method of evaluating this response is very useful for standardizing ginseng extracts to a known bioactivity.