After virus exposure, early bystander naïve CD8 T cell activation relies on NAD+ salvage metabolism

CD8 T cells play a central role in antiviral immunity. Type I interferons are among the earliest responders after virus exposure and can cause extensive reprogramming and antigen-independent bystander activation of CD8 T cells. Although bystander activation of pre-existing memory CD8 T cells is known to play an important role in host defense and immunopathology, its impact on naïve CD8 T cells remains underappreciated. Here we report that exposure to reovirus, both in vitro or in vivo, promotes bystander activation of naïve CD8 T cells within 24 hours and that this distinct subtype of CD8 T cell displays an innate, antiviral, type I interferon sensitized signature. The induction of bystander naïve CD8 T cells is STAT1 dependent and regulated through nicotinamide phosphoribosyl transferase (NAMPT)-mediated enzymatic actions within NAD+ salvage metabolic biosynthesis. These findings identify a novel aspect of CD8 T cell activation following virus infection with implications for human health and physiology.

Alveolar macrophages and epithelial cells: The art of living together

In this issue of JEM, Gschwend et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20210745) reveal the indispensable role of alveolar epithelial cells type 2 in controlling the density of alveolar macrophages. This study highlights the intricate crosstalk that lung stroma and macrophages undergo to maintain homeostasis.

Pulmonary Lymphangioleiomyomatosis originates in the pleural mesothelial cell population

Lymphangioleiomyomatosis (LAM) is a cystic lung disease mainly affecting women, in which degradation of the lung parenchyma is associated with a cell of unknown provenance, known as a LAM cell. LAM cells carry TSC2 mutations and can be identified in the lung parenchyma by their expression of both smooth muscle actin and antigens characteristic of melanocytes and melanocytic tumors. The nature of the cell-of-origin of LAM is controversial, and despite continued research effort remains elusive. Further, it has not been possible to culture pulmonary LAM cells in vitro, and current research relies on cells and animal models which may not recapitulate all features of the disease. We noted aberrant expression of melanoma antigens in pleural mesothelial cells in lung tissue from LAM patients, indicating that these cells could be the precursors of parenchymal LAM cells. We hypothesise that loss of tuberin function following TSC2 mutation in the mesothelial cell lineage gives rise to the cell-of-origin of pulmonary LAM (P-LAM), and of other associated conditions commonly noted in LAM patients. The unique properties of mesothelial cells provide a straightforward explanation of the diverse presentation of LAM.

Multiplexed Relative Quantitation with Isobaric Tagging Mass Spectrometry Reveals Class I Major Histocompatibility Complex Ligand Dynamics in Response to Doxorubicin

MHC-I peptides are intracellular-cleaved peptides, usually 8-11 amino acids in length, which are presented on the cell surface and facilitate CD8⁺ T cell responses. Despite the appreciation of CD8⁺ T-cell antitumor immune responses toward improvement in patient outcomes, the MHC-I peptide ligands that facilitate the response are poorly described. Along these same lines, although many therapies have been recognized for their ability to reinvigorate antitumor CD8⁺ T-cell responses, whether these therapies alter the MHC-I peptide repertoire has not been fully assessed due to the lack of quantitative strategies. We develop a multiplexing platform for screening therapy-induced MHC-I ligands by employing tandem mass tags (TMTs). We applied this approach to measuring responses to doxorubicin, which is known to promote antitumor CD8⁺ T-cell responses during its therapeutic administration in cancer patients. Using both in vitro and in vivo systems, we show successful relative quantitation of MHC-I ligands using TMT-based multiplexing and demonstrate that doxorubicin induces MHC-I peptide ligands that are largely derived from mitotic progression and cell-cycle proteins. This high-throughput MHC-I ligand discovery approach may enable further explorations to understand how small molecules and other therapies alter MHC-I ligand presentation that may be harnessed for CD8⁺ T-cell-based immunotherapies.

RTN4 Knockdown Dysregulates the AKT Pathway, Destabilizes the Cytoskeleton, and Enhances Paclitaxel-Induced Cytotoxicity in Cancers

Reticulon-4 (RTN4), commonly known as a neurite outgrowth inhibitor (Nogo), is emerging as an important player in human cancers. Clinically, we found lower RTN4 expression in patient-derived tumors was associated with significantly better survival in lung, breast, cervical, and renal cancer patients. To identify the role of RTN4 in cancer biology, we performed mass spectrometry-based quantitative proteomic analysis on cancer cells following RTN4 knockdown and found its link with pro-survival as well as cytoskeleton-related processes. Subsequent mechanistic investigations revealed that RTN4 regulates lipid homeostasis, AKT signaling, and cytoskeleton modulation. In particular, downregulation of RTN4 reduced sphingomyelin synthesis and impaired plasma membrane localization of AKT, wherein AKT phosphorylation, involved in many cancers, was significantly reduced without any comparable effect on AKT-related upstream kinases, in a sphingolipid-dependent manner. Furthermore, knockdown of RTN4 retarded proliferation of cancer cells in vitro as well as tumor xenografts in mice. Finally, RTN4 knockdown affected tubulin stability and promoted higher cytotoxic effects with chemotherapeutic paclitaxel in cancer cells both in vitro and in vivo. In summary, RTN4 is involved in carcinogenesis and represents a molecular candidate that may be targeted to achieve desired antitumor effects in clinics.

MHC-I Ligand Discovery Using Targeted Database Searches of Mass Spectrometry Data: Implications for T-Cell Immunotherapies

Class I major histocompatibility complex (MHC-I)-bound peptide ligands dictate the activation and specificity of CD8⁺ T cells and thus are important for devising T-cell immunotherapies. In recent times, advances in mass spectrometry (MS) have enabled the precise identification of these MHC-I peptides, wherein MS spectra are compared against a reference proteome. Unfortunately, matching these spectra to reference proteome databases is hindered by inflated search spaces attributed to a lack of enzyme restriction in the searches, limiting the efficiency with which MHC ligands are discovered. Here we offer a solution to this problem whereby we developed a targeted database search approach and accompanying tool SpectMHC, that is based on a priori-predicted MHC-I peptides. We first validated the approach using MS data from two different allotype-specific immunoprecipitates for the C57BL/6 mouse background. We then developed allotype-specific HLA databases to search previously published MS data sets of human peripheral blood mononuclear cells (PBMCs). This targeted search strategy improved peptide identifications for both mouse and human ligandomes by greater than 2-fold and is superior to traditional "no enzyme" searches of reference proteomes. Our targeted database search promises to uncover otherwise missed novel T-cell epitopes of therapeutic potential.

Abstract 3661: ALDH1A3-inducible RARRES1 is a tumor suppressor in triple-negative breast cancer and is methylated in claudin-low breast cancers

The retinoic acid (RA) signalling pathway plays an important role in breast cancer progression and has either a pro-tumorigenic or tumor-suppressive role depending upon the effector function of RA-inducible genes that are expressed or epigenetically silenced. To study this paradigm in breast cancer, we focused on a controversial RA-inducible gene, the retinoic acid receptor responder 1 (RARRES1) protein that is often hypermethylated in cancer and has been reported to have tumor-suppressive function in prostate and nasopharyngeal carcinomas. However, in a study focused on a rare subtype of breast cancer, inflammatory breast cancer, RARRES1 is pro-tumorigenic. This functional discrepancy requires further investigation to determine its role in breast cancer in general.

First, analysis of patient data sets revealed that RARRES1 is predominantly expressed in triple-negative breast cancers (TNBCs). Knockdown of RARRES1 in claudin-low MDA-MB-231 and basal-like MDA-MB-468 and HCC1937 significantly increased tumor growth and cell proliferation, suggesting RARRES1 has a tumor suppressive function in (TNBC), regardless of position on the differentiation hierarchy.

Expression analyses of 24 breast cancer cell lines (including 18 TNBC and 2 normal-like cell lines) revealed that RARRES1 is predominantly expressed in basal-like TNBC cells We found that RARRES1 expression is dependent on, and strongly correlates with, the cancer stem cell marker, and RA-producing, ALDH1A3 in fixed breast cancer patient samples. Immunohistochemistry of the same patient tumor samples revealed RARRES1 expression is localized to the endoplasmic reticulum.

Importantly, however, the presence of ALDH1A3 or RA is not sufficient to induce RARRES1 expression. RARRES1 is hypermethylated in claudin-low breast cancer cell lines, and release of this silencing is required for full induction of RARRES1 expression. We have identified sites of regulation by methylation in RARRES1 using Illumina 450K methylation arrays and 5-methylcytosine ChIP.

We conclude that RARRES1 is an ALDH1A3/RA-inducible tumor suppressor in TNBC with methylation and expression profiles distinct to the differentiation hierarchy observed in breast cancer.

Citation Format: Krysta M. Coyle, Patrick Murphy, Dejan Vidovic, Cheryl A. Dean, Margaret L. Thomas, Derek Clements, Mohammad Sultan, Ahmad Vaghar-Kashani, Carman Giacomantonio, Lucy Helyer, Ian Weaver, Shashi Gujar, Patrick WK Lee, Paola Marcato. ALDH1A3-inducible RARRES1 is a tumor suppressor in triple-negative breast cancer and is methylated in claudin-low breast cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3661.

Core needle biopsy of breast cancer tumors increases distant metastases in a mouse model

INTRODUCTION: Incisional biopsies, including the diagnostic core needle biopsy (CNB), routinely performed before surgical excision of breast cancer tumors are hypothesized to increase the risk of metastatic disease. In this study, we experimentally determined whether CNB of breast cancer tumors results in increased distant metastases and examine important resultant changes in the primary tumor and tumor microenvironment associated with this outcome. METHOD: To evaluate the effect of CNB on metastasis development, we implanted murine mammary 4T1 tumor cells in BALB/c mice and performed CNB on palpable tumors in half the mice. Subsequently, emulating the human scenario, all mice underwent complete tumor excision and were allowed to recover, with attendant metastasis development. Tumor growth, lung metastasis, circulating tumor cell (CTC) levels, variation in gene expression, composition of the tumor microenvironment, and changes in immunologic markers were compared in biopsied and non-biopsied mice. RESULTS: Mice with biopsied tumors developed significantly more lung metastases compared to non-biopsied mice. Tumors from biopsied mice contained a higher frequency of myeloid-derived suppressor cells (MDSCs) accompanied by reduced CD4 + T cells, CD8 + T cells, and macrophages, suggesting biopsy-mediated development of an increasingly immunosuppressive tumor microenvironment. We also observed a CNB-dependent up-regulation in the expression of SOX4, Ezh2, and other key epithelial-mesenchymal transition (EMT) genes, as well as increased CTC levels among the biopsy group. CONCLUSION: CNB creates an immunosuppressive tumor microenvironment, increases EMT, and facilitates release of CTCs, all of which likely contribute to the observed increase in development of distant metastases.

Abstract 1665: Biopsy induced metastasis: Role of SOX4/TGF-β driven EMT and immunosuppressive microenvironment

As a consequence of advances in digital diagnostic imaging, breast cancers are being diagnosed earlier in their development. These smaller tumors are less likely to be metastatic at time of discovery. The majority of newly diagnosed breast cancers in North America are confirmed using an incisional core needle biopsy (CNB). However an increasing number of studies highlight the pro-metastatic inflammatory and microenvironment changes occurring after incisional procedures on breast cancer tumors. This may account for reported higher incidences of lymph node metastases with increased risk of local recurrence and distant metastasis among patients undergoing incisional procedures.

Evidence from our studies using a metastatic mouse model shows that incisional core needle biopsies lead to increased pulmonary metastasis. To study the mechanism(s) involved we monitored changes in circulating tumor cells (CTC), cytokine levels, variations in gene expression, microenvironment alteration and pulmonary metastatic burden, following CNB.

Gene expression analysis by real-time qPCR showed increased TGF-β expression accompanied by SOX4 upregulation at 3 hours post biopsy (SOX4 is a Master regulator of EMT). This was followed, at 24 hours post biopsy, by significantly increased levels of the SOX4-associated Ezh2 gene and other EMT genes (ZEB2, SNAI2, SNAI3, and CDH2). Monitoring of CTCs over the same time frame showed them to be significantly increased in biopsied mice from 6 to 24 hours post biopsy, indicating continual CTC egress from biopsied tumors. Flow cytometry analysis of tumor microenvironment showed an immunosuppressive microenvironment with increased MDSC levels, reduced CD4+ and CD8+ T cells, macrophage and NKT cell. Interestingly, similar analysis of the Lung microenvironment 4 days later (day 7 post biopsy) revealed an inversion of the tumor situation, in the form of a significant uptick in Th1 type changes described by increased CD4+ and CD8+ type T cells, macrophages and NK cells, as well as increased TNF-β gene expression indicators corresponding to an early response to growth of metastases. We also compared H&E stained histological sections of lungs from biopsied and un-biopsied mice and recorded significant increase in pulmonary metastasis for the biopsied group.

The findings of our study indicate that performance of CNB results in increased metastasis with immunomodulation of the tumor microenvironment and unregulated SOX4/TGF- β. Additional studies are needed to further elucidate the mechanism, and explore mitigating strategies to counter CNB related metastasis.

Citation Format: Edward G. Mathenge, Cheryl Dean, Derek Clements, Ahmad Vagharkashani, Steffany Photopoulos, Krysta Coyle, Benjamin A. Malueth, Mike Giacomantonio, Anna Nunokawa, Julie Jordan, Shashi Gujar, Paola Marcato, Partick Lee, Carman A. Giacomantonio. Biopsy induced metastasis: Role of SOX4/TGF-β driven EMT and immunosuppressive microenvironment. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1665. doi:10.1158/1538-7445.AM2014-1665

Aldehyde dehydrogenase 1A3 influences breast cancer progression via differential retinoic acid signaling

Aldehyde dehydrogenase (ALDH) 1A enzymes produce retinoic acid (RA), a transcription induction molecule. To investigate if ALDH1A1 or ALDH1A3-mediated RA signaling has an active role in breast cancer tumorigenesis, we performed gene expression and tumor xenograft studies. Analysis of breast patient tumors revealed that high levels of ALDH1A3 correlated with expression of RA-inducible genes with retinoic acid response elements (RAREs), poorer patient survival and triple-negative breast cancers. This suggests a potential link between ALDH1A3 expression and RA signaling especially in aggressive and/or triple-negative breast cancers. In MDA-MB-231, MDA-MB-468 and MDA-MB-435 cells, ALDH1A3 and RA increased expression of RA-inducible genes. Interestingly, ALDH1A3 had opposing effects in tumor xenografts, increasing tumor growth and metastasis of MDA-MB-231 and MDA-MB-435 cells, but decreasing tumor growth of MDA-MB-468 cells. Exogenous RA replaced ALDH1A3 in inducing the same opposing tumor growth and metastasis effects, suggesting that ALDH1A3 mediates these effects by promoting RA signaling. Genome expression analysis revealed that ALDH1A3 induced largely divergent gene expression in MDA-MB-231 and MDA-MB-468 cells which likely resulted in the opposing tumor growth effects. Treatment with DNA methylation inhibitor 5-aza-2'deoxycytidine restored uniform RA-inducibility of RARE-containing HOXA1 and MUC4 in MDA-MB-231 and MDA-MB-468 cells, suggesting that differences in epigenetic modifications contribute to differential ALDH1A3/RA-induced gene expression in breast cancer. In summary, ALDH1A3 induces differential RA signaling in breast cancer cells which affects the rate of breast cancer progression.

Reovirus in cancer therapy: an evidence-based review

Reovirus, a double-stranded ribonucleic acid virus and benign human pathogen, preferentially infects and kills cancer cells in its unmodified form, and is one of the leading oncolytic viruses currently undergoing clinical trials internationally. With 32 clinical trials completed or ongoing thus far, reovirus has demonstrated clinical therapeutic applicability against a multitude of cancers, including but not limited to breast cancer, prostate cancer, pancreatic cancer, malignant gliomas, advanced head and neck cancers, and metastatic ovarian cancers. Phase I trials have demonstrated that reovirus is safe to use via both intralesional/intratumoral and systemic routes of administration, with the most common adverse reactions being grade I/II toxicities, such as flu-like illness (fatigue, nausea, vomiting, headache, fever/chills, dizziness), diarrhea, and lymphopenia. In subsequent Phase II trials, reovirus administration was demonstrated to successfully decrease tumor size and promote tumor necrosis, thereby complementing compelling preclinical evidence of tumor destruction by the virus. Importantly, reovirus has been shown to be effective as a monotherapy, as well as in combination with other anticancer options, including radiation and chemotherapeutic agents, such as gemcitabine, docetaxel, paclitaxel, and carboplatin. Of note, the first Phase III clinical trial using reovirus in combination with paclitaxel and carboplatin for the treatment of head and neck cancers is under way. Based on the evidence from clinical trials, we comprehensively review the use of reovirus as an anticancer agent, acknowledge key obstacles, and suggest future directions to ultimately potentiate the efficacy of reovirus oncotherapy.

The NAD+ synthesizing enzyme nicotinamide mononucleotide adenylyltransferase 2 (NMNAT-2) is a p53 downstream target

NAD(+) metabolism plays key roles not only in energy production but also in diverse cellular physiology. Aberrant NAD(+) metabolism is considered a hallmark of cancer. Recently, the tumor suppressor p53, a major player in cancer signaling pathways, has been implicated as an important regulator of cellular metabolism. This notion led us to examine whether p53 can regulate NAD(+) biosynthesis in the cell. Our search resulted in the identification of nicotinamide mononucleotide adenylyltransferase 2 (NMNAT-2), a NAD(+) synthetase, as a novel downstream target gene of p53. We show that NMNAT-2 expression is induced upon DNA damage in a p53-dependent manner. Two putative p53 binding sites were identified within the human NMNAT-2 gene, and both were found to be functional in a p53-dependent manner. Furthermore, knockdown of NMNAT-2 significantly reduces cellular NAD(+) levels and protects cells from p53-dependent cell death upon DNA damage, suggesting an important functional role of NMNAT-2 in p53-mediated signaling. Our demonstration that p53 modulates cellular NAD(+) synthesis is congruent with p53's emerging role as a key regulator of metabolism and related cell fate.

Two is better than one: Complementing oncolytic virotherapy with gemcitabine to potentiate antitumor immune responses

Oncolytic viruses (OVs) preferentially infect and kill cancer cells. Additionally, OV-induced immune responses subvert cancer-associated immunosuppression and promote antitumor immunity. We have recently demonstrated that the complementation of oncolytic virotherapy with gemcitabine accentuates its immunostimulatory effects, hence exerting superior antineoplastic activity.

Gemcitabine enhances the efficacy of reovirus-based oncotherapy through anti-tumour immunological mechanisms

BACKGROUND

Reovirus preferentially infects and kills cancer cells and is currently undergoing clinical trials internationally. While oncolysis is the primary mode of tumour elimination, increasing evidence illustrates that reovirus additionally stimulates anti-tumour immunity with a capacity to target existing and possibly relapsing cancer cells. These virus-induced anti-tumour immune activities largely determine the efficacy of oncotherapy. On the other hand, anti-viral immune responses can negatively affect oncotherapy. Hence, the strategic management of anti-tumour and anti-viral immune responses through complementary therapeutics is crucial to achieve the maximum anti-cancer benefits of oncotherapy.

METHODS

Intra-peritoneal injection of mouse ovarian surface epithelial cells (ID8 cells) into wild-type C57BL/6 mice was treated with a therapeutic regimen of reovirus and/or gemcitabine and then analysed for prolonged survival, disease pathology, and various immunological parameters. Furthermore, in vitro analyses were conducted to assess apoptosis, viral spread, and viral production during reovirus and/or gemcitabine treatment.

RESULTS

We demonstrate that reovirus and gemcitabine combination treatment postpones peritoneal carcinomatosis development and prolongs the survival of cancer-bearing hosts. Importantly, these anti-cancer benefits are generated through various immunological mechanisms, including: (1) inhibition of myeloid-derived suppressor cells recruitment to the tumour microenvironment, (2) downmodulation of pro-MDSC factors, and (3) accelerated development of anti-tumour T-cell responses.

CONCLUSION

The complementation of reovirus with gemcitabine further potentiates virus-initiated anti-cancer immunity and enhances the efficacy of oncotherapy. In the context of ongoing clinical trials, our findings represent clinically relevant information capable of enhancing cancer outcomes.

CCR3 induced-p42/44 MAPK activation protects against staurosporine induced-DNA fragmentation but not apoptosis in airway smooth muscle cells

BACKGROUND

Chemokine receptors (CCRs) are expressed on airway smooth muscle (ASM) cells. As their ligands are present in the airways in asthma, we hypothesized that ASM CCR activation could promote the increase in ASM mass seen in patients with chronic asthma.

OBJECTIVE

To determine which CCRs are expressed by ASM cells and their potential functional relevance to the chronic airway changes seen in asthma.

METHODS

CCR expression in primary ASM cell cultures and airway biopsies from patients with and without asthma was examined by RT-PCR, fluorescence-activated cell sorting and immunohistochemistry. ASM p42/44 MAPK activity, proliferation, migration and apoptosis were examined by western blotting, thymidine incorporation, transwell assay and TUNEL assay respectively.

RESULTS

CCR3 was the most frequently expressed CCR protein and was present on 79 ± 14% of cells. CX3CR1 and CXCR6 were present on 6% and 11% of cells respectively. CCR3 ligands CCL11 and CCL24 caused rapid activation of p42/44 MAPK but not Akt. CCR3 activation did not affect ASM proliferation, migration or VEGF secretion. DNA fragmentation detected by TUNEL staining could be induced by staurosporine and Fas activation although only Fas activation resulted in caspase 3 cleavage. CCL11 and CCL24 protected ASM cells against DNA fragmentation dependent upon p42/44 MAPK activity only via caspase 3 independent pathways. CCR3 was expressed in the smooth muscle and epithelium in the airways of patients with and without asthma. Smooth muscle cell DNA fragmentation in the airways of patients with stable asthma and controls was very uncommon.

CONCLUSIONS AND CLINICAL RELEVANCE

CCR3 is strongly expressed by ASM cells in vitro and in vivo. Protection against cell death by CCR3 activation is dependent on p42/44 MAPK but does not affect caspase 3 mediated apoptosis.

Rectus abdominis myocutaneous flaps for perineal reconstruction: modifications to the technique based on a large single-centre experience

INTRODUCTION

Perineal wound breakdown with delayed wound healing represents a significant cause of morbidity following surgery and radiotherapy to the perineum. The rectus abdominis myocutaneous (RAM) flap has been used increasingly to reconstruct the perineum with good effect. We describe our six-year experience of reconstruction of the perineum with the RAM flap and share some surgical adjuncts we believe are useful.

METHODS

We conducted a retrospective case note review of all patients who underwent a reconstruction of the perineum using the RAM flap between August 2003 and October 2009. Indications for the flap, complication rates and outcomes were all observed.

RESULTS

We conducted 16 RAM flap procedures, 15 of which (94%) were primary repairs and 1 (6%) a secondary repair. Three (19%) developed donor site hernias, two (12.5%) developed minor perineal wound infections, eight (50%) developed minor perineal wound breakdown and in one (6%) flap failure was observed. No perineal hernias were observed. There were no surgical mortalities.

CONCLUSIONS

The RAM flap has a high success rate and an acceptable morbidity rate and is a useful tool in the reconstruction of complex perineal wounds. Modifications to the standard surgical technique may reduce complications and improve the versatility of this flap.

Short-term outcomes with intrathecal versus epidural analgesia in laparoscopic colorectal surgery

BACKGROUND

Epidural analgesia is the mainstay of perioperative pain management in enhanced recovery programmes. This study compared short-term outcomes following epidural or intrathecal analgesia in patients undergoing elective laparoscopic colorectal surgery.

METHODS

A single-centre observational study was carried out in 175 consecutive patients who had elective laparoscopic colorectal surgery for benign or malignant disease within an enhanced recovery programme. Seventy-six patients received epidural analgesia and 99 had a single injection of intrathecal analgesia to provide perioperative pain control.

RESULTS

Patients who had intrathecal analgesia had a reduced median postoperative pain score compared with those receiving epidural analgesia (0 versus 3.5; P < 0.001), an earlier return to mobility (1 versus 4 days; P < 0.001) and a shorter hospital stay (4 versus 5 days; P < 0.001). Return to normal gut function and postoperative nausea and vomiting were similar in the two groups.

CONCLUSION

Intrathecal analgesia may have advantages over epidural analgesia in patients undergoing laparoscopic colorectal surgery.

Management of the asymptomatic primary in the palliative treatment of metastatic colorectal cancer

OBJECTIVE

The management of the asymptomatic primary in stage IV colorectal cancer presents a dilemma. There is an increased morbidity and mortality from surgical resection. Nonresectional management of the primary is associated with the risks of obstruction, perforation or haemorrhage. Our practice in patients with stage IV disease is palliative chemotherapy and symptom control. We reviewed our nonoperatively managed patients with colorectal liver metastases in order to identify the percentage of patients requiring urgent operative interventions for symptoms related to the primary. SUBJECTS/PATIENTS AND METHOD: A retrospective review of all patients treated for stage IV disease at our institution from 2003-2006 was undertaken. Patients were identified from multidisciplinary team (MDT) records. Demographic detail, treatment, and follow-up data were extracted from hospital records. These were analysed with Microsoft Excel.

RESULTS

Thirty-seven patients were identified. 26 Male:11 Female. Median age 63 years (range 38-78). The median survival from diagnosis was 14 months. Three (8%) patients developed obstruction whilst having palliative chemotherapy. Two required a defunctioning stoma, and one was treated by means of a stent. There were no similarities between these three patients in terms of age, sex, site or stage of primary, volume of liver metastases, and alkaline phosphatase (ALP) or carcinoembryonic antigen (CEA) levels.

CONCLUSION

Of 37 patients initially treated palliatively for stage IV colorectal cancer, 92% required no surgical treatment of their primary. Therefore it is the experience of this MDT that it is acceptable to treat such patients in an expectant manner. It is not possible to predict those patients, likely to require surgical intervention.

Application of the BSG guidelines to a colonoscopy waiting list

Abstract Objective Currently priority for colonoscopy is given to diagnostic and therapeutic procedures. Surveillance colonoscopies place a significant demand on the service. These are held on a separate waiting list in our institution, which is currently several years behind. The purpose of this study was to apply the BSG guidelines to this waiting list in our institution in order to ascertain whether patients are appropriately listed. Method This was a retrospective review. The patients on the waiting list whose procedures were due in 2004 and 2005 formed the study group. Information on demographics, previous colonoscopies, and indication was taken from the case notes. Results were analysed using Microsoft Excel. Results A total of 172 patients were overdue their colonoscopies. If the BSG guidelines were strictly adhered to, 49% of these patients were inappropriately listed. If applied less rigidly, 42% of patients should not have been on the list. The reasons for removal from the list were as follows: Thirty-nine patients were older than the upper age limit, 23 had had clear colonoscopies after adenomatous polyp follow up, four were listed for diverticular disease follow up, four for metaplastic polyps, one for constipation and one for per rectum (PR) bleed follow up. Conclusion With strict application of the BSG guidelines to a surveillance colonoscopy waiting list, 49% of the patients on the list do not need the procedure. It is recommended that consultant led education and control of the waiting list be used to reduce unnecessary investigations.

Determining the spatial distribution of viable and nonviable bacteria in hydrated microcosm dental plaques by viability profiling

AIMS

The aim of this study was to use confocal laser scanning microscopy (CLSM) to examine the spatial distribution of both viable and nonviable bacteria within microcosm dental plaques grown in vitro. Previous in vivo studies have reported upon the distribution of viable bacteria only.

METHODS AND RESULTS

Oral biofilms were grown on hydroxyapatite (HA) discs in a constant-depth film fermenter (CDFF) from a saliva inoculum. The biofilms were stained with the BacLight LIVE/DEAD system and examined by CLSM. Fluorescence intensity profiles through the depth of the biofilm showed an offset between the maximum viable intensity and the maximum nonviable intensity. Topographical differences between the surface properties of the viable and nonviable biofilm virtual surfaces were also measured.

CONCLUSIONS

The profile of fluorescence intensity from viable and nonviable staining suggested that the upper layers of the biofilm contain proportionally more viable bacteria than the lower regions of the biofilm.

SIGNIFICANCE AND IMPACT OF STUDY

Viability profiling records the transition from predominantly viable to nonviable bacteria through biofilms suggesting that this technique may be of use for quantifying the effects of antimicrobial compounds upon biofilms. The distribution of viable bacteria was similar to that found in dental plaque in vivo suggesting that the CDFF produces in vitro biofilms which are comparable to their in vivo counterparts in terms of the spatial distribution of viable bacteria.

Delayed post-traumatic osteonecrosis of a vertebral body (Kummell's disease)

Kummell's disease is a rare spinal disorder characterized as avascular necrosis of a vertebral body occurring in a delayed fashion after minor trauma. The disease derives its name from the German surgeon Hermann Kummell, who described a series of patients with the disorder in 1895. Kummell's disease is distinguished from typical osteoporotic compression fractures, by virtue of the fact that patients with Kummell's disease develop symptoms in delayed fashion. In addition, Kummell's disease exhibits different signal characteristics on magnetic resonance imaging when compared to osteoporotic compression fractures. In this review we discuss the pathophysiology, histopathology and treatment of this interesting disorder.

Initiation and early patterning of the endoderm

We review the early stages of endoderm formation in the major animal models. In Amphibia maternal molecules are important in initiating endoderm formation. This is followed by successive signaling events that establish and then pattern the endoderm. In other organisms there are differences in endodermal development, particularly in the initial, prephylotypic stages. Later many of the same key families of transcription factors and signaling cassettes are used in all animals, but more work will be needed to establish exact evolutionary homologies.

Changes in embryonic cell fate produced by expression of an endodermal transcription factor, Xsox17

Many molecules induce the ectopic expression of tissue-specific genes in Xenopus embryos. Conversely, interfering with their activity disrupts patterns of gene expression, implicating them in normal development. Does this mean that they control cell fate (i.e. position, as well as differentiation)? Xsox17alpha and beta can induce ectopic expression of endodermal markers; inhibiting their function suppresses expression of endodermal marker genes in the developing gut (Cell 91 (1997) 397). Here we show the effect of these manipulations on cell lineage. Expressing Xsox17 in a cells normally fated to become ectoderm causes their descendants either to relocate into the embryonic gut or to die at a late developmental stage. Conversely, disrupting Xsox17 activity in cells normally fated to be endodermal causes them to enter mesodermal and ectodermal lineages.

Interference of antibody production to hepatitis B surface antigen in a combination hepatitis A/hepatitis B vaccine

A randomized trial comparing 3 manufacturing consistency lots of a combination hepatitis A/hepatitis B vaccine to each other and to hepatitis A vaccine and hepatitis B vaccine given separately and concurrently was done to evaluate safety, tolerability, and immunogenicity. Healthy volunteers >/=11 years of age were divided into 4 groups. Each of 3 groups received a separate consistency lot of the combination vaccine, and 1 group received separate but concurrent injections of hepatitis A and hepatitis B vaccines. Injections were given at weeks 0 and 24. The combination vaccine was generally well tolerated. The hepatitis A portion of the combination vaccine produced clinically acceptable high seropositivity rates 4 and 52 weeks after the first injection. The hepatitis B portion of the vaccine did not produce clinically acceptable seropositivity rates 4 weeks after the second injection. Lack of antibody production may be attributed, at least in part, to immunologic interference.

Mode of action of VegT in mesoderm and endoderm formation

mRNA encoding the T-box transcription factor VegT is located throughout the vegetal pole of the Xenopus egg and is believed to play an important part in endoderm and mesoderm formation. We find that VegT generates endoderm both by cell-autonomous action and by generating TGF-beta family signals, the latter being entirely responsible for its mesoderm-inducing activity. Signalling molecules induced cell-autonomously by VegT include derriere, Xnr4 and activin B. Xnr1 and Xnr2 are also induced, but primarily in a non-autonomous manner. All of these signalling molecules are found in the blastula and gastrula vegetal pole and induce both endoderm and mesoderm in the animal cap assay, and hence are good candidates both for the endogenous zygotic mesoderm-inducing signal and for reinforcing the vegetal expression of endoderm markers.

Biomarkers of oxidative stress are significantly elevated in Down syndrome

There is convincing epidemiological and in vitro evidence of chronic oxidative stress in individuals with Down syndrome (DS). These individuals develop Alzheimer like changes in the brain in their 30s and 40s. The incidence of autoimmune diseases and cataracts is significantly increased, and the overall ageing process is accelerated. In vitro studies show that impaired viability of DS neurons may be amended by simple chemical antioxidants, such as vitamin E, BHT and propyl gallate, clearly indicative of oxyl radical involvement. However, because of the lack of in vivo experiments, the role of oxidative stress in DS remains controversial. We report here on the results of the chemical analyses of urine samples of 166 individuals, where DS subjects were matched by their siblings. The levels of 8-hydroxy-2'-deoxyguanosine (2.35 +/- 1.69 in DS vs. 1.35 +/- 1.04 in controls, P = 0.00011), a biomarker of oxidative damage to DNA, and malondialdehyde (0.255 +/- 0.158 in DS vs. 0.204 +/- 0.128 in controls, P = 0.033), a biomarker of lipid peroxidation, are significantly elevated in individuals with DS. Dietary influences failed to show any significant correlation with the oxidative stress biomarkers. These results provide direct evidence for increased oxidative stress in individuals with DS.

Xsox17alpha and -beta mediate endoderm formation in Xenopus

We have isolated two Xenopus relatives of murine Sox17 expressed in gastrula presumptive endoderm. Xsox17alpha and -beta expression can be induced in animal caps by activin, but not by FGF. Ectopic expression of these genes in animal caps induces the expression of endoderm markers; this induction is blocked by overexpression of a fusion of the Xsox17beta HMG domain to the Drosophila Engrailed repressor domain, as is induction of endoderm markers by activin and the expression of endodermal markers in whole embryos and isolated vegetal poles. These experiments, as well as the effects of the mRNAs on embryo phenotypes, suggest that the Xsox17 genes mediate an activin-induced endoderm differentiation pathway in animal caps and are involved in normal endoderm differentiation in embryos.

Semirigid instrumentation in the management of lumbar spinal conditions combined with circumferential fusion. A multicenter study

STUDY DESIGN

Patients with the diagnosis of degenerative disc conditions or spondylolisthesis undergoing circumferential fusion with posterior pedicle screw fixation using a semirigid rod were reviewed.

OBJECTIVES

To determine the effectiveness of this approach in achieving a spinal fusion and satisfactory clinical outcome, and to determine the complications associated with the procedure.

SUMMARY OF BACKGROUND DATA

The use of instrumentation to stabilize the lumbar motion segments and thereby enhance the fusion rate has been proposed in a number of studies. Semirigid fixation was believed to be effective in achieving these objectives without concern for stress-shielding, which was suggested by some authors using rigid fixation systems.

METHODS

Patients who required spinal fusion with anterior and posterior approaches because of specific lumbar pathology or previous surgeries were selected. The surgery consisted of an anterior interbody fusion using allograft, followed by a posterolateral fusion and pedicle screw fixation. Fusion was determined by continuity of trabecular bridging, and outcomes were determined by pain reduction and return to previous levels of activity. Fusion was considered solid if the two posterolateral areas were fused (Zones one and two), if the anterior interbody area was fused (Zone three), or if all three zones were fused. Complications were documented during and after surgery.

RESULTS

Sixty-two percent of patients had previous surgery with 25% of these patients having a diagnosis of pseudarthrosis. Fifty-five percent of patients had two or more levels fused, and 43% were heavy smokers. Ninety-seven percent of patients had successful fusions. Pain was significantly reduced on a pain analogue scale from 7.1 to 2.1 in the back and from 5.8 to 1.5 in the leg (p < 0.006 and 0.0001, respectively). Fifty-nine percent of patients returned to their previous level of activity, and 18% returned to lighter work or job retraining, for a total of 77% returning to the same or lighter levels of activity. Complications included metal failure, 4.9%; neurologic deficit, 1.2%; deep infection, 1.2%; deep venous thrombosis, 4.9%; and vascular injury, 2.4%. Fatal pulmonary embolus occurred in one patient.

CONCLUSION

This technique produces a satisfactory fusion rate (97%) and a good clinical outcome based on pain reduction and return to a satisfactory level of activity (77%). It is associated with few, but significant, complications that compare well with other reported series in a difficult group of patients. This procedure should be reserved for patients who are considered to be at high risk for not achieving spinal fusion.

Distinct regulatory control of the Brachyury gene in axial and non-axial mesoderm suggests separation of mesoderm lineages early in mouse gastrulation

Brachyury is required for the normal extension of the anteroposterior axis during mouse embryogenesis. A transgene comprising sequences from -500 to +150 relative to the start of Brachyury transcription, and the reporter gene lacZ, recapitulates some, but not all elements of Brachyury expression. Beta-Galactosidase expression is seen in the primitive streak from 6.5 d.p.c. but there is no detectable reporter expression in the node or notochord. Thus, the regulatory sequences required for the expression of Brachyury in the cells traversing the primitive streak are distinct from those required for the initiation of expression in the node. This suggests that different or additional signals are involved in activation of Brachyury in the node and notochord than those inducing Brachyury in the primitive streak. Additionally, the data suggest the possibility that axial and non-axial mesoderm are distinct from the earliest stages of Brachyury expression.

Safety and cellular and humoral immune responses of a booster dose of varicella vaccine 6 years after primary immunization

Four hundred nineteen children and adolescents immunized with live varicella vaccine 4-6 years earlier were enrolled in a study to evaluate the safety and immune response to a booster dose containing approximately 3300 pfu of virus. Of the subjects, 99% (414/419) maintained antibody to varicella zoster virus (VZV) with a geometric mean titer of 25.7 and mean stimulation index (SI) for VZV-specific lymphoproliferation response of 40.3 +/- 5.3 (SE). Some 7-10 days after the booster immunization, seropositivity rates increased to 100% (302/302), and GMT was 143.6 (anamnestic response). At 6 weeks after the booster inoculation, a subset of subjects had 100% seropositivity (74/74) with a GMT of 218.8 and an SI of 58.6. After 3 months, seropositivity was 100% (358/358), GMT was 119.0, and SI was 61.4.

Audit of coding in gastrointestinal endoscopy

The accuracy of the coding of gastrointestinal endoscopic procedures at Llandough Hospital was audited over 12 months. Although the endoscopy unit kept its own records, none of the staff were initially aware of the coding system used for endoscopic procedures for subsequent hospital activity analysis. Conventional typed discharge summaries were usually inadequate for coding purposes, and there was considerable variation in the proportion of procedures coded. Changes made to improve the accuracy and completeness of coding for endoscopic procedures were seen to be effective in a follow-up study.

Bone loss in normal British women; a 5 year follow-up

To assess the rates of loss, forearm and spinal bone mineral were remeasured in 16 out of 18 peri- and post-menopausal women aged 45 to 60 years who had taken part in a previously reported cross-sectional study. The mean interval between measurements was 4.8 years (range 4.2-5.3 years). The mean (95% confidence interval (CI)) annual change in radial bone mineral density was -0.78%/year (-1.73 to +0.18%; not significant) and in spinal bone mineral -2.41%/year (-3.55 to 1.27%; p < 0.001). There was considerable variation in the rate of change in radius and spine, and between individuals. There was no significant correlation between rates of bone loss at either site, or between rates of loss and the initial bone density at either the radius or spine. There was no significant correlation between the rates of change and the age or number of years post-menopause of the women. There was no significant change in the Z score for the forearm (mean -0.20; 95% CI -0.65 to +0.25) or for the spine (mean -0.04; 95% CI -0.30 to +0.22). There have been no previous longitudinal studies of the changes of bone density in normal British women. These results show considerable variation between individuals, and rates of change at one site cannot be predicted from measurements at another site. Untreated, some normal individuals have high rates of loss that cannot be predicted from baseline values, age or number of years post-menopause.

Hormone replacement therapy prevents bone loss in patients with inflammatory bowel disease

Patients with inflammatory bowel disease have an increased prevalence of osteoporosis, and suffer high rates of spinal bone loss. Hormone replacement therapy (HRT) is effective in the treatment and prevention of osteoporosis but has not been studied in patients with inflammatory bowel disease. A two year prospective study of HRT in inflammatory bowel disease was performed in 47 postmenopausal women aged 44 to 67 years with ulcerative colitis (25) or Crohn's disease (22). Patients had radial and spinal bone density measured annually by single photon absorptiometry and quantitative computed tomography respectively. The mean (95% confidence intervals) annual change in radial bone density was +1.42%/yr (+0.58 to +2.26; P < 0.005) and for spinal bone +2.60%/yr (+1.06 to +4.15; p < 0.005). There was no significant correlation between rates of change of bone density at the two sites, or between the rates of change and the initial bone density either in the radius or spine. Twelve patients were given prednisolone during the study, and their rates of change for spinal bone density were lower, but values were not statistically significantly different from those who did not receive corticosteroids. Changes in bone density for patients with ulcerative colitis and Crohn's disease were not significantly different. The change in bone density did not correlate with the patients' age or number of years after the menopause. It is concluded that HRT is effective in prevention of bone loss in postmenopausal women with inflammatory bowel disease.

A four-year longitudinal study of bone loss in patients with inflammatory bowel disease

Serial measurements of spinal trabecular and radial cortical bone density were made over 4 years in 70 patients with inflammatory bowel disease. Mean rates of bone loss for the cohort differed little from rates reported in normal populations; however, some patients showed increased rates of loss, including patients whose bone density at entry to the study was already well below normal. There was a significant correlation between the amount of corticosteroid prescribed and spinal trabecular bone loss in males, but no significant correlation with other clinical parameters. Increased rates of bone loss emphasise the need for bone densitometry and prophylactic measures in patients with inflammatory bowel disease.

Hormone replacement therapy in chronic active hepatitis; a case report

There is an increased incidence of osteoporosis in patients with chronic liver disease. Because patients with chronic active hepatitis (CAH) usually require corticosteroids for their liver disease prevention and treatment of bone loss presents a difficult problem. This case report describes a 41 year old female patient with CAH who had a high rate of bone loss. After an early menopause with noticeable menopausal symptoms, she was given transdermal oestrogen replacement therapy. The menopausal symptoms resolved completely, and there was no deterioration in her liver function tests or corticosteroid requirement. In addition, follow up quantitative bone mineral measurements over two years have shown improvement. This case shows the value of measurements of bone density, and oestrogen replacement therapy in CAH, even in the presence of continued corticosteroids.