Hong Kong consensus recommendations on the management of pancreatic ductal adenocarcinoma

This project was undertaken to develop the first set of consensus statements regarding the management of pancreatic ductal adenocarcinoma (PDAC) in Hong Kong, with the goal of providing guidance to local clinicians. A multidisciplinary panel of experts discussed issues surrounding current PDAC management and reviewed evidence gathered in the local context to propose treatment recommendations. The experts used the Delphi approach to finalise management recommendations. Consensus was defined as ≥80% acceptance among all expert panel members. Thirty-nine consensus statements were established. These statements cover all aspects of PDAC management, including diagnosis, resectability criteria, treatment modalities according to resectability, personalised management based on molecular profiling, palliative care, and supportive care. This project fulfils the need for guidance regarding PDAC management in Hong Kong. To assist clinicians with treatment decisions based on varying levels of evidence and clinical experience, treatment options are listed in several consensus statements.

A colorimetric lateral flow immunoassay based on oriented antibody immobilization for sensitive detection of SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19). The high human-to-human transmission and rapid evolution of SARS-CoV-2 have resulted in a worldwide pandemic. To contain SARS-CoV-2, it is essential to efficiently control the transmission of the virus through the early diagnosis of infected individuals, including asymptomatic people. Therefore, a rapid and accurate assay is vital for the early diagnosis of SARS-CoV-2 in suspected individuals. In this study, we developed a colorimetric lateral flow immunoassay (LFIA) in which a CBP31-BC linker was used to immobilize antibodies on a cellulose membrane in an oriented manner. The developed LFIA enabled sensitive detection of cultured SARS-CoV-2 in 15 min with a detection limit of 5 × 10⁴ copies/mL. The clinical performance of the LFIA for detecting SARS-CoV-2 was evaluated using 19 clinical samples validated by reverse transcription-polymerase chain reaction (RT-PCR). The LFIA detected all the positive and negative samples accurately, corresponding to 100% accuracy. Importantly, patient samples with low viral loads were accurately identified. Thus, the proposed method can provide a useful platform for rapid and accurate point-of-care testing of SARS-CoV-2 in infected individuals to efficiently control the COVID-19 pandemic.

Virus-like nanoparticles as a theranostic platform for cancer

Virus-like nanoparticles (VLPs) are natural polymer-based nanomaterials that mimic viral structures through the hierarchical assembly of viral coat proteins, while lacking viral genomes. VLPs have received enormous attention in a wide range of nanotechnology-based medical diagnostics and therapies, including cancer therapy, imaging, and theranostics. VLPs are biocompatible and biodegradable and have a uniform structure and controllable assembly. They can encapsulate a wide range of therapeutic and diagnostic agents, and can be genetically or chemically modified. These properties have led to sophisticated multifunctional theranostic platforms. This article reviews the current progress in developing and applying engineered VLPs for molecular imaging, drug delivery, and multifunctional theranostics in cancer research.

Successful implementation of diabetes audits in Australia: the Australian National Diabetes Information Audit and Benchmarking (ANDIAB) initiative

AIM

We developed and implemented a national audit and benchmarking programme to describe the clinical status of people with diabetes attending specialist diabetes services in Australia.

METHODS

The Australian National Diabetes Information Audit and Benchmarking (ANDIAB) initiative was established as a quality audit activity. De-identified data on demographic, clinical, biochemical and outcome items were collected from specialist diabetes services across Australia to provide cross-sectional data on people with diabetes attending specialist centres at least biennially during the years 1998 to 2011.

RESULTS

In total, 38 155 sets of data were collected over the eight ANDIAB audits. Each ANDIAB audit achieved its primary objective to collect, collate, analyse, audit and report clinical diabetes data in Australia. Each audit resulted in the production of a pooled data report, as well as individual site reports allowing comparison and benchmarking against other participating sites.

CONCLUSIONS

The ANDIAB initiative resulted in the largest cross-sectional national de-identified dataset describing the clinical status of people with diabetes attending specialist diabetes services in Australia. ANDIAB showed that people treated by specialist services had a high burden of diabetes complications. This quality audit activity provided a framework to guide planning of healthcare services.

Repeated threat (without direct harm) alters metabolic capacity in select regions that drive defensive behavior

To understand the behavioral consequences of intermittent anticipatory stress resulting from threats without accompanying physiological challenges, we developed a semi-naturalistic rodent housing and foraging environment that can include threats that are unpredictable in timing. Behavior is automatically recorded while rats forage for food or water. Over three weeks, the threats have been shown to elicit risk assessment behaviors, increase defensive burying and increase adrenal gland weight. To identify brain regions activated by this manipulation, we measured cytochrome c oxidase (COX), which is tightly coupled to neural activity. Adolescent male Sprague-Dawley rats were randomly assigned to control (CT) or unpredictable threat/stress (ST) housing conditions consisting of two tub cages, one with food and another with water, separated by a tunnel. Over three weeks (P31-P52), the ST group received randomly timed (probability of 0.25), simultaneous presentations of ferret odor, an abrupt light, and sound at the center of the tunnel. The ST group had consistently fewer tunnel crossings than the CT group, but similar body weights. Group differences in COX activity were detected in regions implicated in the control of defensive burying. There was an increase in COX activity in the hypothalamic premammillary dorsal nucleus (PMD) and lateral septum (LS), whereas a decrease was observed in the periaqueductal gray (PAG) and CA3 region of the hippocampus. There were no significant differences in the anterior cingulate cortex, prefrontal cortex, striatum or motor cortex. The sites with changes in metabolic capacity are candidates for the sites of plasticity that may underlie the behavioral adaptations to intermittent threats.

Induction of endoplasmic reticulum stress by deletion of Grp78 depletes Apc mutant intestinal epithelial stem cells

Intestinal epithelial stem cells are highly sensitive to differentiation induced by endoplasmic reticulum (ER) stress. Colorectal cancer develops from mutated intestinal epithelial stem cells. The most frequent initiating mutation occurs in Apc, which results in hyperactivated Wnt signalling. This causes hyperproliferation and reduced sensitivity to chemotherapy, but whether these mutated stem cells are sensitive to ER stress induced differentiation remains unknown. Here we examined this by generating mice in which both Apc and ER stress repressor chaperone Grp78 can be conditionally deleted from the intestinal epithelium. For molecular studies, we used intestinal organoids derived from these mice. Homozygous loss of Apc alone resulted in crypt elongation, activation of the Wnt signature and accumulation of intestinal epithelial stem cells, as expected. This phenotype was however completely rescued on activation of ER stress by additional deletion of Grp78. In these Apc-Grp78 double mutant animals, stem cells were rapidly lost and repopulation occurred by non-mutant cells that had escaped recombination, suggesting that Apc-Grp78 double mutant stem cells had lost self-renewal capacity. Although in Apc-Grp78 double mutant mice the Wnt signature was lost, these intestines exhibited ubiquitous epithelial presence of nuclear β-catenin. This suggests that ER stress interferes with Wnt signalling downstream of nuclear β-catenin. In conclusion, our findings indicate that ER stress signalling results in loss of Apc mutated intestinal epithelial stem cells by interference with the Wnt signature. In contrast to many known inhibitors of Wnt signalling, ER stress acts downstream of β-catenin. Therefore, ER stress poses a promising target in colorectal cancers, which develop as a result of Wnt activating mutations.

Association between basal-like phenotype and BRCA1/2 germline mutations in Korean breast cancer patients

INTRODUCTION

BRCA mutation testing allows index patients and their families to be provided with appropriate cancer risk-reduction strategies. Because of the low prevalence of BRCA mutations in unselected breast cancer patients and the high cost of genetic testing, it is important to identify the subset of women who are likely to carry BRCA mutations. In the present study, we examined the association between BRCA1/2 germline mutations and the immunohistochemical features of breast cancer.

METHODS

In a retrospective review of 498 breast cancer patients who had undergone BRCA testing at Seoul National University Bundang Hospital between July 2003 and September 2012, we gathered immunohistochemical information on estrogen receptor (er), progesterone receptor (pr), her2 (human epidermal growth factor receptor 2), cytokeratin 5/6, egfr (epidermal growth factor receptor), and p53 status.

RESULTS

Among the 411 patients eligible for the study, 50 (12.2%) had germline mutations in BRCA1 or BRCA2. Of the 93 patients with triple-negative breast cancer (tnbc), 25 with BRCA1/2 mutations were identified (BRCA1, 20.4%; BRCA2, 6.5%). On univariate analysis, er, pr, cytokeratin 5/6, egfr, and tnbc were found to be related to BRCA1 mutations, but on multivariate analysis, only tnbc was significantly associated with BRCA1 mutations. Among patients with early-onset breast cancer or with a family history of breast or ovarian cancer, BRCA1 mutations were significantly more prevalent in the tnbc group than in the non-tnbc group.

CONCLUSIONS

In the present study, tnbc was the only independent predictor of BRCA1 mutation in patients at high risk of hereditary breast and ovarian cancers. Other histologic features of basal-like breast cancer did not improve the estimate of BRCA1 mutation risk.

L-type Ca2+ channels in mood, cognition and addiction: integrating human and rodent studies with a focus on behavioural endophenotypes

Brain Ca_v 1.2 and Ca_v 1.3 L-type Ca²⁺ channels play key physiological roles in various neuronal processes that contribute to brain function. Genetic studies have recently identified CACNA1C as a candidate risk gene for bipolar disorder (BD), schizophrenia (SCZ), major depressive disorder (MDD) and autism spectrum disorder (ASD), and CACNA1D for BD and ASD, suggesting a contribution of Ca_v 1.2 and Ca_v 1.3 Ca²⁺ signalling to the pathophysiology of neuropsychiatric disorders. Once considered sole clinical entities, it is now clear that BD, SCZ, MDD and ASD share common phenotypic features, most likely due to overlapping neurocircuitry and common molecular mechanisms. A major future challenge lies in translating the human genetic findings to pathological mechanisms that are translatable back to the patient. One approach for tackling such a daunting scientific endeavour for complex behaviour-based neuropsychiatric disorders is to examine intermediate biological phenotypes in the context of endophenotypes within distinct behavioural domains. This will better allow us to integrate findings from genes to behaviour across species, and improve the chances of translating preclinical findings to clinical practice.

Weak peristalsis with large breaks in chronic cough: association with poor esophageal clearance

BACKGROUND

Gastroesophageal reflux plays an important role in chronic cough (CC). Whether disturbed esophageal motility contributes to increased esophageal reflux exposure or interferes with swallowed bolus clearance is unclear. This study used high resolution esophageal manometry and impedance (HRIM) together with Chicago Classification, and 24-h impedance pH (MII/pH) to address these questions in patients with CC compared with heartburn (HB).

METHODS

A retrospective review of 32 patients with CC (mean age 57 [95% CI: 52-62] years) and 32 patients with symptoms of HB (55 [52-62] years) referred for HRIM and MII/pH between September 2012 and September 2013 was undertaken.

KEY RESULTS

Weak peristalsis with large breaks (WPLBs) was observed in 34% of CC patients compared with only 12% of HB patients (p = 0.027). Pathological acid exposure time (AET) was identified in 81% of CC patients with WPLBs compared with 29% without (p = 0.011). Increased AET was associated with prolonged clearance time of refluxed events (p = 0.006) rather than increased number of events. AET correlated with the percentage of peristaltic events with large breaks in CC (ρ = 0.467, p = 0.007). Similar data were obtained for total bolus (acid and non-acid) exposure time. Only one of the CC patients with WPLBs exhibited complete bolus transit (CBT) on swallowing compared with 81% without WPLBs (p < 0.001). Moreover, the percentage of peristaltic events associated with CBT negatively correlated with the percentage of peristaltic events with large breaks (r = -0.653, p < 0.001) in CC.

CONCLUSIONS & INFERENCES

One-third of CC patients exhibit WPLBs, which directly impacts on clearance of refluxed events and bolus's swallowed. These observations may have important implications for esophageal-bronchial interaction in CC.

GRP78 as a regulator of liver steatosis and cancer progression mediated by loss of the tumor suppressor PTEN

Glucose-regulated protein 78 (GRP78), a molecular chaperone widely elevated in human cancers, is critical for endoplasmic reticulum (ER) protein folding, stress signaling and PI3K/AKT activation. Genetic knockout models of GRP78 revealed that GRP78 maintains homeostasis of metabolic organs, including liver, pancreas and adipose tissues. Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the most common liver cancers. There is a lack of effective therapeutics for HCC and CC, highlighting the need to further understand liver tumorigenic mechanisms. PTEN, a tumor suppressor that antagonizes the PI3K/AKT pathway, is inactivated in a wide range of tumors, including 40–50% of human liver cancers. To elucidate the role of GRP78 in liver cancer, we created a mouse model with biallelic liver-specific deletion of Pten and Grp78 mediated by Albumin-Cre-recombinase (cP^f/f78^f/f). Interestingly, in contrast to PTEN, deletion of GRP78 was progressive but incomplete. At 3 months, cP^f/f78^f/f livers showed hepatomegaly, activation of lipogenic genes, exacerbated steatosis and liver injury, implying that GRP78 protects the liver against PTEN-null mediated pathogenesis. Furthermore, in response to liver injury, we observed increased proliferation and expansion of bile duct and liver progenitor cells in cP^f/f78^f/f livers. Strikingly, bile duct cells in cP^f/f78^f/f livers maintained wild-type (WT) GRP78 level while adjacent areas showed GRP78 reduction. Analysis of signaling pathways revealed selective JNK activation, β-catenin downregulation, along with PDGFRα upregulation, which was unique to cP^f/f78^f/f livers at 6 months. Development of both HCC and CC was accelerated and evident in cP^f/f78^f/f livers at 8–9 months, coinciding with intense GRP78 expression in the cancer lesions, and GRP78 expression in adjacent normal areas reverted back to the WT level. In contrast, c78^f/f livers showed no malignancy even at 14 months. These studies reveal GRP78 is a novel regulator for PTEN-loss mediated liver injury and cancer progression.

miR-30d, miR-181a and miR-199a-5p cooperatively suppress the endoplasmic reticulum chaperone and signaling regulator GRP78 in cancer

GRP78, a major endoplasmic reticulum chaperone and signaling regulator, is commonly overexpressed in cancer. Moreover, induction of GRP78 by a variety of anti-cancer drugs, including histone deacetylase inhibitors, confers chemoresistance to cancer, thereby contributing to tumorigenesis. Thus, therapies aimed at decreasing GRP78 levels, which results in the inhibition of tumor cell proliferation and resensitization of tumor cells to chemotherapeutic drugs may hold promise for cancer treatment. Despite advances in our understanding of GRP78 actions, little is known about endogenous inhibitors controlling its expression. As endogenous regulators, microRNAs (miRNAs) play important roles in modulating gene expression; therefore, we sought to identify miRNA(s) that target GRP78, under the hypothesis that these miRNAs may serve as therapeutic agents. Here, we report that three miRNAs (miR-30d, miR-181a, miR-199a-5p) predicted to target GRP78 are down-regulated in prostate, colon and bladder tumors, and human cancer cell lines. We show that in C42B prostate cancer cells, these miRNAs down-regulate GRP78 and induce apoptosis by directly targeting its 3' untranslated region. Importantly, we demonstrate that the three miRNAs act cooperatively to decrease GRP78 levels, suggesting that multiple miRNAs may be required to efficiently control the expression of some genes. In addition, delivery of multiple miRNAs by either transient transfection or lentivirus transduction increased the sensitivity of cancer cells to the histone deacetylase inhibitor, trichostatin A, in C42B, HCT116 and HL-60 cells. Together, our results indicate that the delivery of co-transcribed miRNAs can efficiently suppress GRP78 levels and GRP78-mediated chemoresistance, and suggest that this strategy holds therapeutic potential.

Toll-like receptor 7 stimulation promotes autoimmune diabetes in the NOD mouse

AIMS/HYPOTHESIS

The role of Toll-like receptor 7 (TLR7), a sensor of viral and self RNA, in promoting autoimmune diabetes remains unclear. Our goal was to determine the effect of TLR7 stimulation on the priming and activation of diabetogenic CD8(+) T cells.

METHODS

We explored the effects of CL097 (TLR7/8 agonist) and immunoregulatory sequence 661 (IRS661, TLR7 inhibitor) on bone marrow-derived dendritic cells (BMDCs), diabetogenic CD8(+) T cell function and autoimmune diabetes onset in NOD and 8.3 NOD T cell receptor transgenic mice (8.3 NOD mice).

RESULTS

TLR7 stimulation of NOD BMDCs increased activation and production of proinflammatory cytokines. In vivo administration of CL097 activated T cells and dendritic cells and increased levels of proinflammatory cytokines and type 1/2 IFNs in NOD mice. In vivo antigen-specific cytotoxicity studies revealed enhanced cytotoxicity against islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP, an islet autoantigen) peptide pulsed targets in NOD mice treated with CL097 plus CD40 agonist. This combination treatment accelerated the onset of autoimmune diabetes in 8.3 NOD mice. Likewise, topical treatment of NOD mice with a TLR7 agonist accelerated diabetes onset. Spontaneous disease in 8.3 NOD mice and accelerated disease in CL097+CD40 agonist-treated 8.3 NOD mice were delayed by IRS661 treatment, which is associated with inhibition of the endogenous upregulation of IFN-α levels within the pancreatic lymph nodes.

CONCLUSIONS/INTERPRETATION

TLR7 stimulation accelerates the spontaneous onset of autoimmune diabetes in 8.3 NOD and NOD mice. Conversely, TLR7 inhibition prevents the early events associated with diabetogenesis.

GRP78 promoter polymorphism rs391957 as potential predictor for clinical outcome in gastric and colorectal cancer patients

BACKGROUND

Recently, the analysis of gastric and colorectal tumor specimens determined that 78-kiloDalton glucose-regulated protein (GRP78), an endoplasmic reticulum chaperone, up-regulation serves as an efficient mechanism protecting cells against apoptosis and can confer drug resistance. We tested whether functional polymorphisms within the GRP78 gene are related to clinical outcome in gastric and colorectal cancer (CRC) patients.

PATIENTS AND METHODS

Blood samples of 234 stage II/III CRC patients at the University of Southern California (USC) and formalin-fixed paraffin-embedded tissues of 137 patients with localized gastric adenocarcinoma (GA) at USC and Memorial Sloan-Kettering Cancer Centers were obtained. GRP78 polymorphisms analyzed on germline DNA were correlated with clinical outcome using univariate and multivariate analyses.

RESULTS

GA patients with the combined GRP78 rs391957 C/T and T/T genotype were at higher risk for tumor recurrence and death [hazard ratio (HR) 2.61; P < 0.001 and HR 3.17; P < 0.001, respectively], than those with C/C. These findings were subsequently tested in a CRC cohort where patients with the homozygous T/T genotype were at highest risk for tumor recurrence (HR 2.61; P = 0.015). The results remained significant after adjusting for clinicopathologic determinants.

CONCLUSION

These data provide the first evidence that the GRP78 rs391957 polymorphism can predict clinical outcome in localized GA and locally advanced CRC patients.

Gut barrier disruption by an enteric bacterial pathogen accelerates insulitis in NOD mice

AIMS/HYPOTHESIS

Increased exposure to enteric microbes as a result of intestinal barrier disruption is thought to contribute to the development of several intestinal inflammatory diseases; however, it less clear whether such exposure modulates the development of extra-intestinal inflammatory and autoimmune diseases. The goal of this study was to examine the potential role of pathogenic enteric microbes and intestinal barrier dysfunction in the pathogenesis of type 1 diabetes.

METHODS

Using NOD mice, we assessed: (1) intrinsic barrier function in mice at different ages by measuring serum levels of FITC-labelled dextran; and (2) the impact on insulitis development of infection by strains of an enteric bacterial pathogen (Citrobacter rodentium) either capable (wild-type) or incapable (lacking Escherichia coli secreted protein F virulence factor owing to deletion of the gene [DeltaespF]) of causing intestinal epithelial barrier disruption.

RESULTS

Here we demonstrate that prediabetic (12-week-old) NOD mice display increased intestinal permeability compared with non-obese diabetes-resistant and C57BL/6 mice. We also found that young (4-week-old) NOD mice infected with wild-type C. rodentium exhibited accelerated development of insulitis in concert with infection-induced barrier disruption. In contrast, insulitis development was not altered in NOD mice infected with the non-barrier-disrupting DeltaespF strain. Moreover, C. rodentium-infected NOD mice demonstrated increased activation and proliferation of pancreatic-draining lymph node T cells, including diabetogenic CD8(+) T cells, compared with uninfected NOD mice.

CONCLUSIONS/INTERPRETATION

This is the first demonstration that a loss of intestinal barrier integrity caused by an enteric bacterial pathogen results in the activation of diabetogenic CD8(+) T cells and modulates insulitis.

Essential role of the unfolded protein response regulator GRP78/BiP in protection from neuronal apoptosis

Neurodegenerative diseases are often associated with dysfunction in protein quality control. The endoplasmic reticulum (ER), a key site for protein synthesis, senses stressful conditions by activating the unfolded protein response (UPR). Here we report the creation of a novel mouse model where GRP78/BiP, a major ER chaperone and master regulator of UPR, is specifically eliminated in the Purkinje cells (PCs). GRP78 depleted PCs activate UPR including induction of GRP94, PDI, CHOP and GADD34, feedback suppression of eIF2α phosphorylation and apoptotic cell death. In contrast to current models of protein misfolding where abnormal accumulation of ubiquitinated protein is prominent, cytosolic ubiquitin staining is dramatically reduced in GRP78 null PCs. Ultrastructural evaluation reveals that the ER shows prominent dilatation with focal accumulation of electron-dense material within the ER. The mice show retarded growth and severe motor coordination defect by week 5 and cerebellar atrophy by week 13. Our studies uncover a novel link between GRP78 depletion and reduction in cytosolic ubiquitination and establish a novel mouse model of accelerated cerebellar degeneration with basic and clinical applications.

Aberrant middle turbinate masquerading as a nasopharyngeal mass

We present a unique variant of the middle turbinate that extends posteriorly through the choana to wrap around the posterior free edge of the nasal septum. The embryology and anatomy of the lateral nasal wall and the nasal septum are reviewed.

Agreement of anti-neutrophil cytoplasmic antibody measurements obtained from serum and plasma

Serum and plasma are used interchangeably to measure anti-neutrophil cytoplasmic antibodies (ANCA), even though the release of ANCA target antigens during the preparation of serum could affect ANCA assays and cause discrepancies between the results obtained from serum and plasma. To what extent ANCA test results obtained from serum agree and correlate with results from plasma remains unknown. Therefore, a comprehensive comparison was performed using serum and plasma samples which were collected in 175 patients with active Wegener's granulomatosis at enrollment of a recent randomized trial. These paired serum and plasma samples were subjected to parallel ANCA testing by standard indirect immunofluorescence on ethanol-fixed neutrophils, a direct enzyme-linked immunoassay (ELISA) for proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA, and two different capture ELISAs for PR3-ANCA. The concordance of categorical serum and plasma ANCA results was assessed using kappa-coefficients. These were > 0.8 for all assays, indicating a very good concordance between positive and negative serum and plasma results. Spearman's correlation coefficients for serum and plasma PR3-ANCA values obtained by direct ELISA and both capture ELISAs were > or = 0.95 (P < 0.0001). Our study shows that serum and plasma samples can be used interchangeably for measuring ANCA.

The effect of dexamethasone on defective nephrin transport caused by ER stress: a potential mechanism for the therapeutic action of glucocorticoids in the acquired glomerular diseases

The mechanism by which glucocorticoids govern antiproteinuric effect in nephrotic syndrome remains unknown. Present study examined the protective role of dexamethasone (DEX) in the intracellular trafficking of nephrin under endoplasmic reticulum (ER) stress. Human embryonic kidney-293 cell line expressing a full-length human nephrin was cultured in mediums containing 5.5 or 25 mM glucose with or without DEX. The result revealed that glucose starvation evoked a rapid ER stress leading to formation of underglycosylated nephrin that was remained in the ER as a complex with calreticulin/calnexin. DEX rescued this interfered trafficking through binding to its receptor and stimulating the mitochondrial transcripts and adenosine 5' triphosphate (ATP) production, leading to synthesis of fully glycosylated nephrin. These results suggest that ER-stress in podocytes may cause alteration of nephrin N-glycosylation, which may be an underlying factor in the pathomechanism of the proteinuria in nephrotic syndrome. DEX may restore this imbalance by stimulating expression of mitochondrial genes, resulted in the production of ATP that is essential factor for proper folding machinery aided by the ER chaperones.

Characterization of the structure and properties of authentic and counterfeit polypropylene surgical meshes

A counterfeit version of the Ethicon Prolene polypropylene mesh was distributed to hospitals and clinics and unintentionally implanted into patients undergoing tension-free hernia repair. On December 19, 2003, the Food and Drug Administration (FDA) issued a public health web notification indicating that the counterfeit mesh was not sterile or safe to use. To develop safety recommendations for patients with the counterfeit mesh implant, we compared the counterfeit's structural, physical, chemical and mechanical properties with polypropylene meshes previously cleared by FDA. The mesh fibers for all the products tested were found to have similar chemical and physical properties. The mechanical properties were directly related to the knitted structure (loop size, repeat distance, fabric tightness) and the porosity. Extracts from the counterfeit mesh passed cytotoxicity screening tests. The FDA further recommended that if the mesh had been inadvertently implanted, then those patients should be monitored as would be the practice for any patient with an implanted surgical mesh.

Brachiocephalic-superior vena cava metallic stenting in malignant superior vena cava obstruction

INTRODUCTION

We studied the effectiveness of unilateral brachiocephalic (BC)-superior vena cava (SVC) metallic stent therapy in malignant SVC obstruction.

MATERIALS AND METHODS

From November 1998 to February 2002, SVC stenting was performed in 11 patients with symptomatic malignant SVC obstruction. There were 10 males and 1 female, with a mean age of 64.2 years (range, 37 to 78 years). The computed tomography (CT) scan and superior vena cavogram findings of all patients showed malignant SVC obstruction. Both internal jugular veins were patent in all patients by ultrasound. SVC stenting was performed with Wallstent (Boston Scientific, Minneapolis, MN, USA) in 10 patients and Memotherm stent (Bard angiomed, Wachhausstrasse, Germany) in 1 patient. Pressure gradient, duration of the procedure, peri-procedural morbidity and mortality and the general well-being of the patients were reviewed.

RESULTS

SVC stenting was performed at a mean duration of 9.6 days (range, 3 to 30 days) after presentation. All were technically successful with 10 across the right BC-SVC and 1 across the left BC-SVC. There was no peri-procedural morbidity or mortality. The entire procedure was completed at a mean duration of 115 minutes (range, 75 to 225 minutes) with good angiographic and pressure results. Immediate symptomatic relief of SVC syndrome was achieved in 10 patients who had received prompt work-up and stenting 3 to 18 days after presentation. The remaining patient, who received work-up and stenting 30 days after presentation, remained dyspnoeic and died of pneumonia 7 days after the procedure.

CONCLUSION

Unilateral BC-SVC metallic stenting is an effective measure in malignant SVC obstruction. Prompt pre-stenting work-up and stenting are recommended to achieve a longer symptomatic relief period.

Patellar tendon length following opening wedge high tibial osteotomy using an external fixator with particular reference to later total knee replacement

The aim of this retrospective study was to examine a cohort of patients who had undergone high tibial osteotomy (HTO) using the method of opening wedge hemicallotasis, and who later required conversion to total knee replacement (TKR). The incidence of patella infra and any technical difficulties encountered during TKR operation were examined. A consecutive series of 76 valgus osteotomies in 65 patients were carried out by one surgeon using a dynamic axial fixator (DAF). Later conversion to TKR, required for the progression of symptoms, was carried out in nine knees (seven patients) at a mean time from the initial osteotomy of 7 years (1.5-11). All of those patients who underwent HTO and subsequently required conversion to TKR were followed up. The patellar height was assessed by one observer in all knees pre- and post-HTO using the Insall and Salvati and Blackburne and Peel ratios. Using these criteria, only one case of patella infra occurred. There were no added technical difficulties in performing TKR as a result of the previous osteotomy and clinical outcomes using the Oxford knee score were satisfactory (34 where 48 is maximum).

The glucose-regulated proteins: stress induction and clinical applications

A protective mechanism used by cells to adapt to stress of the endoplasmic reticulum (ER) is the induction of members of the glucose-regulated protein (Grp) family. The induction of mammalian Grp proteins in response to ER stress involves a complex network of regulators and novel mechanisms. The elucidation of Grp function and regulation opens up new therapeutic approaches to diseases associated with ER stress and cancer.

Novel mutations in ndh in isoniazid-resistant Mycobacterium tuberculosis isolates

Novel mutations in NADH dehydrogenase (ndh) were detected in 8 of 84 (9.5%) isoniazid (INH)-resistant isolates (T110A [n = 1], R268H [n = 7]), but not in 22 INH-susceptible isolates of Mycobacterium tuberculosis. Significantly, all eight isolates with mutations at ndh did not have mutations at katG, kasA, or the promoter regions of inhA or ahpC, except for one isolate. Mutations in ndh appear to be an additional molecular mechanism for isoniazid resistance in M. tuberculosis.

Identification of TFII-I as the endoplasmic reticulum stress response element binding factor ERSF: its autoregulation by stress and interaction with ATF6

When mammalian cells are subjected to stress targeted to the endoplasmic reticulum (ER), such as depletion of the ER Ca(2+) store, the transcription of a family of glucose-regulated protein (GRP) genes encoding ER chaperones is induced. The GRP promoters contain multiple copies of the ER stress response element (ERSE), consisting of a unique tripartite structure, CCAAT(N(9))CCACG. Within a subset of mammalian ERSEs, N(9) represents a GC-rich sequence of 9 bp that is conserved across species. A novel complex (termed ERSF) exhibits enhanced binding to the ERSE of the grp78 and ERp72 promoters using HeLa nuclear extracts prepared from ER-stressed cells. Optimal binding of ERSF to ERSE and maximal ERSE-mediated stress inducibility require the conserved GGC motif within the 9-bp region. Through chromatographic purification and subsequent microsequencing, we have identified ERSF as TFII-I. Whereas TFII-I remains predominantly nuclear in both nontreated NIH 3T3 cells and cells treated with thapsigargin (Tg), a potent inducer of the GRP stress response through depletion of the ER Ca(2+) store, the level of TFII-I transcript was elevated in Tg-stressed cells, correlating with an increase in TFII-I protein level in the nuclei of Tg-stressed cells. Purified recombinant TFII-I isoforms bind directly to the ERSEs of grp78 and ERp72 promoters. The stimulation of ERSE-mediated transcription by TFII-I requires the consensus tyrosine phosphorylation site of TFII-I and the GGC sequence motif of the ERSE. We further discovered that TFII-I is an interactive protein partner of ATF6 and that optimal stimulation of ERSE by ATF6 requires TFII-I.

Vitrectomy for pars planitis complicated by vitreous hemorrhage: visual outcome and long-term follow-up

PURPOSE

To characterize the visual results of vitrectomy for nonclearing vitreous hemorrhage in pars planitis.

METHODS

Case series.

RESULTS

All six eyes (100%) had a visual acuity of 20/200 or less preoperatively. Postoperatively, five eyes (83%) improved to a final visual acuity of better than 20/30, and one eye improved to 20/100. The poorer vision of the latter patient was attributed to cystoid macular edema. Postoperative follow-up range was from 1.3 to 9 years (mean, 4.2 years).

CONCLUSION

A substantial long-term benefit is seen in patients with pars planitis treated with vitrectomy for nonclearing vitreous hemorrhage. A larger case series will be needed to confirm whether such excellent outcomes can be expected.

YY1 as a regulator of replication-dependent hamster histone H3.2 promoter and an interactive partner of AP-2

In analyzing cis-regulatory elements important for cell cycle control of the replication-dependent hamster histone H3.2 gene, we discovered a binding site for the transcription factor YY1 embedded within GC-rich sequences between the two tandem CCAAT repeats proximal to the TATA element. Base mutations that specifically eliminated YY1 binding resulted in suppression of the S phase induction of the H3.2 promoter. In addition, we discovered that YY1 is an interactive partner of AP-2, which also binds the H3.2 promoter and regulates its cell cycle-dependent expression. The critical domains for YY1 and AP-2A interaction are mapped, revealing that the N-terminal portion of YY1 (amino acids 1-300) and the DNA-binding/dimerization region of AP-2A are required. Our results suggest that YY1, acting as a transcription factor binding to its site on the promoter, or through protein-protein interaction with AP-2, may be part of a regulatory network including key cell cycle regulators such as c-Myc and Rb in controlling growth- and differentiation-regulated gene expression.

High tibial osteotomy using a dynamic axial external fixator

High tibial osteotomy is an accepted treatment for unicompartmental osteoarthritis of the knee. Conventional osteotomy can be a demanding procedure with potential for complications. Opening wedge high tibial osteotomy using an external fixator is an alternative that may have advantages in comparison with classic methods. The aims of the current study were to determine if opening wedge osteotomy using hemicallotasis techniques is safer than, and the outcome comparable with that of, conventional techniques. Seventy-six high tibial osteotomies were performed in 65 patients for primary osteoarthritis. The mean age of the patients was 54.8 years (range, 36-70 years). The mean followup was 6 years. The only serious complication occurred in one patient, who had chronic osteomyelitis develop 2 years after surgery. There were no neurologic or vascular complications. The authors think this technique is safer than conventional techniques. Survivorship at 5 and 10 years was 89% and 63%, respectively. The mean knee score in osteotomies was 26.6 (maximum possible score, 48). The outcome is comparable with, or better than, that of other techniques for osteotomy. Subsequent knee replacement, in cases requiring conversion, was straightforward. The mean score in knees that had osteotomies that were converted to total knee replacements was 33.7.

Upregulation of BiP and CHOP by the unfolded-protein response is independent of presenilin expression

Presenilin 1 (PS1), a polytopic membrane protein, has a critical role in the trafficking and proteolysis of a selected set of transmembrane proteins. The vast majority of individuals affected with early onset familial Alzheimer's disease (FAD) carry missense mutations in PS1. Two studies have suggested that loss of PS1 function, or expression of FAD-linked PS1 variants, compromises the mammalian unfolded-protein response (UPR), and we sought to evaluate the potential role of PS1 in the mammalian UPR. Here we show that that neither the endoplasmic reticulum (ER) stress-induced accumulation of BiP and CHOP messenger RNA, nor the activation of ER stress kinases IRE1alpha and PERK, is compromised in cells lacking both PS1 and PS2 or in cells expressing FAD-linked PS1 variants. We also show that the levels of BiP are not significantly different in the brains of individuals with sporadic Alzheimer's disease or PS1-mediated FAD to levels in control brains. Our findings provide evidence that neither loss of PS1 and PS2 function, nor expression of PS1 variants, has a discernable impact on ER stress-mediated induction of the several established 'readouts' of the UPR pathway.

Heterogeneous nuclear ribonucleoproteins as regulators of gene expression through interactions with the human thymidine kinase promoter

In search for nuclear proteins that interact with the human thymidine kinase (htk) promoter, we discovered that p37AUF, a hnRNP C-like protein, and hnRNP A1, both members of the heterogeneous ribonucleoprotein family, can bind with high affinity to an ATTT sequence motif contained within the cell cycle regulatory unit (CCRU). We report here that over-expression of p37AUF stimulates gene expression mediated by the htk promoter in a promoter-sequence specific manner, whereas hnRNP A1 suppresses it. Both recombinant p37AUF and hnRNP A1 can bind the htk CCRU, suggesting that their binding to the DNA target does not require additional cellular components. We further discovered that hnRNP K is a potent suppressor of htk mediated gene activity. However, its mechanism of action is mediated through protein-protein interaction, since hnRNP K itself cannot bind the htk CCRU but can competitively inhibit the binding of other hnRNPs. The binding site for the hnRNPs on the htk CCRU is not required for S-phase induction of the htk promoter. However, in stable but not transient transfectants, the mutation of the hnRNP binding site results in 5- to 10-fold reduction of htk mediated gene activity in synchronized and exponentially growing cells. Collectively, these findings support emerging evidence that hnRNPs, in addition to their traditional role in RNA biogenesis, could be regulators of gene expression through direct DNA binding or interaction with other proteins.

Detailed deletion mapping at chromosome 11q23 in colorectal carcinoma

Loss of heterozygosity (LOH) is frequent at the chromosomal region 11q22-q23 in several types of tumours of diverse cell origin. Previous investigations of LOH at this chromosomal region in colorectal carcinoma have been contradictory in their findings, and have only included between 1-4 loci. In order to define any regions of LOH on 11q23, we investigated 16 loci between D11S940 and D11S934 on the long arm of chromosome 11 using microsatellite analysis. Of 57 colorectal carcinomas specimens, 36 (63.2%) demonstrated LOH at one or more marker, with the highest frequencies of LOH at D11S1340 (41.0%), located between 105.13-111.97 Mb from the centromere, and D11S924 (37.1%) and D11S4107 (40.5%), both located approximately 113 Mb from the centromere. No statistically significant associations between LOH and age-of-presentation or Dukes' stage were found. LOH was observed in colorectal tumours of all Dukes' stages, including Dukes' stages A and B, suggesting that the inactivation of a tumour suppressor gene(s) on 11q23 occurs in the early stages of colorectal carcinoma. These results confirm the presence of putative tumour suppressor gene(s) at chromosome 11q23, involved in the carcinogenesis of colorectal carcinoma, and will facilitate future identification of candidate genes.

ATF6 as a transcription activator of the endoplasmic reticulum stress element: thapsigargin stress-induced changes and synergistic interactions with NF-Y and YY1

ATF6, a member of the leucine zipper protein family, can constitutively induce the promoter of glucose-regulated protein (grp) genes through activation of the endoplasmic reticulum (ER) stress element (ERSE). To understand the mechanism of grp78 induction by ATF6 in cells subjected to ER calcium depletion stress mediated by thapsigargin (Tg) treatment, we discovered that ATF6 itself undergoes Tg stress-induced changes. In nonstressed cells, ATF6, which contains a putative short transmembrane domain, is primarily associated with the perinuclear region. Upon Tg stress, the ATF6 protein level dropped initially but quickly recovered with the additional appearance of a faster-migrating form. This new form of ATF6 was recovered as soluble nuclear protein by biochemical fractionation, correlating with enhanced nuclear localization of ATF6 as revealed by immunofluorescence. Optimal ATF6 stimulation requires at least two copies of the ERSE and the integrity of the tripartite structure of the ERSE. Of primary importance is a functional NF-Y complex and a high-affinity NF-Y binding site that confers selectivity among different ERSEs for ATF6 inducibility. In addition, we showed that YY1 interacts with ATF6 and in Tg-treated cells can enhance ATF6 activity. The ERSE stimulatory activity of ATF6 exhibits properties distinct from those of human Ire1p, an upstream regulator of the mammalian unfolded protein response. The requirement for a high-affinity NF-Y site for ATF6 but not human Ire1p activity suggests that they stimulate the ERSE through diverse pathways.

Low-level doxorubicin resistance in benzo[a]pyrene-treated KB-3-1 cells is associated with increased LRP expression and altered subcellular drug distribution

The P-glycoprotein (P-gp)-negative epidermoid pharyngeal carcinoma cells KB-3-1 were grown in 0.25 mM benzo[a]pyrene (BaP) for 3 months and increased resistance to doxorubicin, but not to vinblastine, colchicine, or cisplatin, was found. Doxorubicin resistance was not altered by cyclosporin, the P-gp inhibitor. Intracellular accumulation of BaP or calcein, a substrate for P-gp and multidrug resistance protein (MRP), was not altered by inhibitors of the P-gp and MRP. The expression of cytochrome P450 (CYP) 1A1, lung-resistance-related protein (LRP), P-gp, and MRP was investigated. Overexpression of CYP1A and LRP, on the mRNA and protein levels, was found. BaP-treated KB-3-1 cells remained P-gp negative while the level of MRP was not altered. Subcellular accumulation of BaP was found to be localized in the cytoplasm and minimal in the nuclei in BaP treated cells. In contrast, even penetration of BaP to the nuclei and cytoplasm was found in untreated cells. Subcellular distribution of doxorubicin was altered following BaP treatment with localized accumulation of the cancer drug in cytoplasmic organelles but not in the nuclei. Our data suggested that LRP might play a protective role against toxic compounds. The correlation of increased expression of LRP, but not P-gp nor MRP, with decreased doxorubicin accumulation in the nuclear target suggests a pivotal role of this perinuclear transporter in the MDR phenotype of P-gp-negative cancer cells. These results also propose an alternative mechanism of cancer drug resistance emergence, namely, induction of LRP activity following treatment with BaP, an environmental toxicant and a carcinogen.

Triclosan: a review of effectiveness and safety in health care settings

Triclosan is a widely accepted antimicrobial ingredient because of its safety and antimicrobial efficacy. Triclosan is a unique antimicrobial well suited for use in the health care industry in which mildness is a necessity to protect the health care worker during repeated use and antimicrobial activity is a necessity to protect public health. Triclosan has demonstrated immediate, persistent, broad-spectrum antimicrobial effectiveness and utility in clinical health care settings. This review highlights the utility and effectiveness of a 1% triclosan formulation for use in high-risk, high-frequency handwashing.

Improvement in macular function after retinal translocation surgery in a patient with age-related macular degeneration

PURPOSE

To assess focal electroretinographic findings before and after retinal translocation surgery in a patient with age-related macular degeneration.

METHOD

Case report. A 79-year-old man with a well-defined subfoveal choroidal neovascular membrane from age-related macular degeneration underwent preoperative and postoperative focal electroretinography.

RESULTS

After retinal translocation surgery, best-corrected Snellen visual acuity improved from 9/200 to 20/60. A significant increase in mean foveal amplitude, from 0.08 microV to 0.16 microV (P = 0.008) was recorded.

CONCLUSION

Age-related macular degenerative changes in visual acuity and foveal electroretinogram amplitude may be reversible after retinal translocation surgery.

Eradication of murine mammary adenocarcinoma through HSVtk expression directed by the glucose-starvation inducible grp78 promoter

Gene therapy strategies employing the HSVtk/ganciclovir (GCV) suicide gene offer promising approaches towards the treatment of metastatic breast cancer. These include bystander effects on non-transduced tumor cells, lower systemic toxicity, and the possibility of inducing immunity against the tumor. Previously we have demonstrated the ability of the grp78 stress-inducible promoter to stimulate expression of reporter genes within the tumor microenvironment. However, experimental evidence demonstrating the ability of this promoter to activate therapeutic agents within the breast cancer environment causing tumor eradication is needed prior to clinical trials. In this report, we test the efficacy of the grp78 promoter in a retroviral system to drive the expression of the HSVtk suicide gene in a murine mammary adenocarcinoma cell line (TSA) in syngeneic, immune-competent hosts. Our results show that under glucose-starvation conditions in vitro, the expression of HSVtk and GCV induced cell death are enhanced in tumor cells in which the HSVtk gene is driven by the internal grp78 promoter compared to cells in which the Moloney murine leukemia virus LTR drives HSVtk. In in vivo studies, in tumors in which the HSVtk gene is driven by the grp78 promoter, GCV treatment causes complete tumor eradication, whereas tumors persist when the HSVtk gene is driven by the retroviral LTR. Our study suggests that the grp78 promoter may be useful to enhance the effectivity of therapeutic agents within a breast tumor. In addition, it is shown that immune memory is induced in syngeneic, immune-competent hosts. This new retroviral vector might therefore be useful for breast cancer gene therapy.

Clinical and immunocytochemical findings in a case of melanoma-associated retinopathy

OBJECTIVE

To describe an unusual case of melanoma-associated retinopathy (MAR).

DESIGN

Retrospective, observational case report and experimental study.

PARTICIPANTS

A 61-year-old man with a history of cutaneous melanoma, acquired bilateral central scotomas, and night blindness.

INTERVENTION

Serial full-field electroretinography (ERG) and Goldmann perimetry were performed. Serum was screened for cancer-associated retinopathy (CAR) antibodies by Western blotting. Sections of human and rat retina were examined by immunofluorescence microscopy to determine whether retinal cells were reactive with this patient's serum. A metastatic workup was performed.

MAIN OUTCOME MEASURES

Electroretinography, Goldmann visual field testing, and immunocytochemistry were performed.

RESULTS

The results were as follows: (1) The ERG showed a profound loss of the b-wave amplitude and a "negative" b-wave characteristic of congenital stationary night blindness; (2) a central scotoma and peripheral constriction were identified on Goldmann visual field tests; (3) as in other patients with MAR, bipolar cells in human and rat retinas were immunolabeled with this patient's serum; and (4) a previously unsuspected focus of metastatic melanoma was discovered.

CONCLUSIONS

Recognition of this condition may help to identify an occult focus of metastatic melanoma.

Conservation and divergence of the yeast and mammalian unfolded protein response. Activation of specific mammalian endoplasmic reticulum stress element of the grp78/BiP promoter by yeast Hac1

Yeast Hac1 (yHac1), the transcription factor that binds and activates the unfolded protein response element of endoplasmic reticulum (ER)-chaperone gene promoters, only accumulates in stressed cells after an unconventional splicesosome-free mRNA processing step and escape from translation block. In determining whether the novel regulatory mechanisms for yHac1 are conserved in mammalian cells, we discovered a unique unfolded protein response element-like sequence within the endoplasmic reticulum stress element 163, one of the three ER stress elements recently identified in the rat grp78 promoter. The unspliced form of yHac1 is stably expressed in nonstressed mammalian cells and is as active as the spliced form in stimulating the promoter activities of grp genes. Further, the yHac1 mRNA is not processed in response to ER stress in mammalian cells. We identified a CCAGC motif as the yHac1 binding site, which is contained within a YY1 binding site previously shown to be important for mammalian UPR. Dissection of the yHac1 and the YY1 binding sites uncovered specific contact points for an activator protein predicted to be the mammalian homolog of yHac1, the activity of which can be stimulated by YY1. A model of the conserved and unique features of the yeast and mammalian unfolded protein response transcription machinery is proposed.

The Endoplasmic Reticulum Chaperone Glycoprotein GRP94 with Ca2+-binding and Antiapoptotic Properties Is a Novel Proteolytic Target of Calpain during Etoposide-induced Apoptosis

GRP94 is a 94-kDa chaperone glycoprotein with Ca(2+)-binding properties. We report here that during apoptosis induced by the topoisomerase II inhibitor etoposide, a fraction of GRP94 associated with the endoplasmic reticulum membrane undergoes specific proteolytic cleavage, coinciding with the activation of the caspase CPP32 and initiation of DNA fragmentation. In vivo, inhibitors of caspases able to block etoposide-induced apoptosis can only partially protect GRP94 from proteolytic cleavage, whereas complete inhibition is observed with calpain inhibitor I but not with the proteasome inhibitor. In vitro, GRP94 is not a substrate for CPP32; rather, it can be completely cleaved by calpain, a Ca(2+)-regulated protease. The cleavage of GRP94 by calpain is Ca(2+)-dependent and generates a discrete polypeptide of 80 kDa. In contrast, calpain has no effect on other stress proteins such as GRP78 or HSP70. Further, immunohistochemical staining reveals specific co-localization of GRP94 with calpain in the perinuclear region following etoposide treatment. We further showed that reduction of GRP94 by antisense decreased cell viability in etoposide-treated Jurkat cells. Our studies provide new evidence that the cytoprotective GRP94, as in the case of the antiapoptotic protein Bcl-2, can be targets of proteolytic cleavage themselves during the apoptotic process.

Contribution of kasA analysis to detection of isoniazid-resistant Mycobacterium tuberculosis in Singapore

Genotypic analysis of resistance to isoniazid (INH) in Mycobacterium tuberculosis is complex due to the various genes potentially involved. Mutations in ketoacyl acyl carrier protein synthase (encoded by kasA) were present in 16 of 160 (10%) INH-resistant isolates (R121K [n = 1], G269S [n = 3], G312S [n = 11], G387D [n = 1]). However, G312S was also present in 6 of 32 (19%) susceptible strains. kasA analysis contributed marginally to the performance of INH genotypic testing in Singapore. The significance of kasA polymorphisms in INH resistance should be carefully established.

Use of the glucose starvation-inducible glucose-regulated protein 78 promoter in suicide gene therapy of murine fibrosarcoma

A new strategy in anticancer gene therapy uses stress-responsive cellular promoters that offer the advantage of enhanced gene expression in a variety of tumors. Although the feasibility of their selective expression has been demonstrated, functional evidence of their ability to activate therapeutic agents within the tumor environment leading to tumor eradication has not been established. Glucose deprivation, chronic anoxia, and acidic pH known to persist in poorly vascularized solid tumors strongly induce the transcription of the glucose-regulated protein 78 (grp78) gene, which encodes an Mr 78,000 stress-inducible protein. In this report, we tested directly the efficacy of the grp78 promoter in a retroviral system to drive the expression of the herpes simplex virus-thymidine kinase (HSVtk) suicide gene, using a murine fibrosarcoma model, in the context of their syngeneic, immunocompetent hosts. Our results showed that under glucose starvation conditions, the expression of HSVTK was enhanced in tumor cells where the HSVtk gene was driven by the internal grp78 promoter, in contrast to the Moloney murine leukemia virus long terminal repeat, where suppression was observed. We further demonstrated that in vivo, HSVTK expression was elevated to much higher levels inside tumors when driven by the internal grp78 promoter, resulting in complete eradication of sizable tumor mass, with no recurrence of tumor growth. Our study suggests that the glucose starvation-inducible grp78 promoter could be useful for enhanced expression of a variety of therapeutic agents within the solid tumor environment.

Recovery of poliovirus from cut surface of stored fresh papaya fruit

Poliovirus kept on the cut surfaces of fully ripe papaya cubes placed in an ice box showed a sharp and significant reduction in the recovery of infectious virus about 15 minutes after exposure. Thereafter, a very gradual decrease ensued and infectious residual virus was detected up to the end of the 6-hour exposure period. Papaya cubes washed or kept overnight before virus inoculation, and from less ripe fruits produced a similar survival pattern. A very small proportion of the inoculum was recovered from the mashed content of the inoculated papaya cubes thus suggesting that most of the non-recovered virus particles were inactivated. The results suggest that the importance of poliovirus-contaminated cut papayas as a transmission vehicle for the virus is greatly reduced by the rapid decline in the infectivity of a large proportion of the virus soon after contamination. Nevertheless, the potential to transmit remains as a small residual pool of infectious poliovirus is able to survive for a relatively long period.

Vertebral Aspergillus osteomyelitis and acute diskitis in patients with chronic obstructive pulmonary disease

Aspergillus osteomyelitis of the spine with acute diskitis has been well documented in immunocompromised hosts but is rare in immunocompetent patients. Predisposing factors to infection are prolonged neutropenia, hematologic malignancies, chemotherapy, history of prior spinal trauma or surgery, allograft transplantation, or any condition requiring the use of long-term immunosuppressive agents or systemic corticosteroids. Patients with chronic obstructive pulmonary disease (COPD) treated with systemic corticosteroids for either long-term management or frequent exacerbations are at potential risk for such infections. Patients with severe COPD treated primarily with inhaled corticosteroids are considered immunocompetent. This report describes 2 cases of Aspergillus osteomyelitis with acute diskitis in apparently immunocompetent patients with COPD who, aside from brief courses of systemic corticosteroids, were using inhaled corticosteroid therapy. One patient was treated with intravenous amphotericin B alone, whereas the other received amphotericin B and underwent surgical debridement. Both have done well and were symptom free at 6-month follow-up.