Prognosis of glioblastoma patients improves significantly over time interrogating historical controls

BACKGROUND

Glioblastoma (GBM) is the most common devastating primary brain cancer in adults. In our clinical practice, median overall survival (mOS) of GBM patients seems increasing over time.

METHODS

To address this observation, we have retrospectively analyzed the prognosis of 722 newly diagnosed GBM patients, aged below 70, in good clinical conditions (i.e. Karnofsky Performance Status -KPS- above 70%) and treated in our department according to the standard of care (SOC) between 2005 and 2018. Patients were divided into two groups according to the year of diagnosis (group 1: from 2005 to 2012; group 2: from 2013 to 2018).

RESULTS

Characteristics of patients and tumors of both groups were very similar regarding confounding factors (age, KPS, MGMT promoter methylation status and treatments). Follow-up time was fixed at 24 months to ensure comparable survival times between both groups. Group 1 patients had a mOS of 19 months ([17.3-21.3]) while mOS of group 2 patients was not reached. The recent period of diagnosis was significantly associated with a longer mOS in univariate analysis (HR=0.64, 95% CI [0.51 - 0.81]), p < 0.001). Multivariate Cox analysis showed that the period of diagnosis remained significantly prognostic after adjustment on confounding factors (adjusted Hazard Ratio (aHR) 0.49, 95% CI [0.36-0.67], p < 0.001).

CONCLUSION

This increase of mOS over time in newly diagnosed GBM patients could be explained by better management of potentially associated non-neurological diseases, optimization of validated SOC, better management of treatments side effects, supportive care and participation in clinical trials.

A systematic review of the impact of brain tumours on risk of motor vehicle crashes

PURPOSE

Brain tumours are associated with neurocognitive impairments that are important for safe driving. Driving is vital to maintaining patient autonomy, despite this there is limited research on driving capacity amongst patients with brain tumours. The purpose of this review is to examine MVC risk in patients with brain tumours to inform development of clearer driving guidelines.

METHODS

A systematic review was performed using Medline and EMBASE. Observational studies were included. The outcome of interest was MVC or measured risk of MVC in patients with benign or malignant brain tumours. Descriptive analysis and synthesis without meta-analysis were used to summarise findings. A narrative review of driving guidelines from Australia, United Kingdom and Canada was completed.

RESULTS

Three studies were included in this review. One cohort study, one cross-sectional study and one case-control study were included (19,135 participants) across United States and Finland. One study evaluated the incidence of MVC in brain tumour patients, revealing no difference in MVC rates. Two studies measured MVC risk using driving simulation and cognitive testing. Patients found at higher risk of MVC had greater degrees of memory and visual attention impairments. However, predictive patient and tumour characteristics of MVC risk were heterogeneous across studies. Overall, driving guidelines had clear recommendations on selected conditions like seizures but were vague surrounding neurocognitive deficits.

CONCLUSION

Limited data exists regarding driving behaviour and MVC incidence in brain tumour patients. Existing guidelines inadequately address neurocognitive complexities in this group. Future studies evaluating real-world data is required to inform development of more applicable driving guidelines.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO 2023 CRD42023434608.

Hashimoto's thyroiditis and renal transplant rejection

PURPOSE

Hashimoto's thyroiditis (HT) is a common autoimmune thyroid disorder that can disrupt thyroid function and homeostasis. As HT results from a dysregulated immune system, we hypothesized that these patients might be more susceptible to transplant failure; however, literature on this association is limited. The purpose of this study is to examine the association of HT with the risk of renal transplant failure.

METHODS

We utilized the United States Renal Database System dataset collected from 2005 to 2014 and compared the time from first renal transplant to transplant failure in end-stage renal disease (ESRD) patients with a HT diagnosis to ESRD patients without a HT diagnosis that underwent renal transplant.

RESULTS

A total of 144 ESRD patients had International Classification of Disease-9 claim codes for HT prior to renal transplant, amongst a total cohort of 90,301 renal transplant patients aged 18-100 and meeting criteria. Patients with HT were significantly more likely to be female, white, and to have a diagnosis of cytomegalovirus compared to patients without. ESRD patients with a HT diagnosis that underwent renal transplant had a significantly increased risk of renal transplant failure compared to those ESRD renal transplant patients without an HT diagnosis. There was a significantly increased adjusted hazard ratio for graft failure in patients with a HT diagnosis compared to those without.

CONCLUSION

Thyroid health and HT may play a significant role in the development of the increased risk of renal transplant failure observed in this study. Additional studies are needed to investigate the underlying mechanisms for this association.

Human pegivirus identified in severe myelitis and optic neuritis in immunocompromised patients: A pathogenic role for a forgotten virus?

The role of Human pegivirus (HPgV) in patients with encephalitis has been recently questioned. We present cases of 4 patients with similar clinical, biological, and radiological characteristics, including a past history of transplantation with long-term immunosuppression and a progressive course of severe and predominantly myelitis, associated in 3 cases with optic neuropathy causing blindness. Extensive workup was negative but analysis of the CSF by use of pan-microorganism DNA- and RNA-based shotgun metagenomics was positive for HPgV. This case series further supports the hypothesis of HPgV CNS infection and highlights the utility of metagenomic next-generation sequencing of CSF in immunocompromised patients.

OS07.1.A A threshold of mitotic activity and post-surgery residual volume are independant prognostic factors in astrocytoma IDH-mutant

Background

The distinction between grade 2 and 3 is instrumental to choose between observational follow-up and adjuvant treatment in resected astrocytoma IDH-mutant. However, criteria of grade 2 versus 3 have not been updated since the WHO 2007 classification. There is no consensus on the method of evaluation of the mitotic activity or a cut-off of mitoses separating grade 2 and grade 3 tumors. The objectives were to evaluate the maximal mitotic activity on a series of resected astrocytoma IDH-mutant and assess its prognostic impact on survival.

Material and Methods

Maximal mitotic activity on consecutive high power fields corresponding to 3 mm2 was examined in 118 lower-grade astrocytoma IDH-mutant. The prognostic value for time-to-treatment (TTT) and overall survival (OS) of mitotic activity and other putative prognostic factors (including age, performance status, pre-surgical tumor volume, plurilobar involvement, post-surgical residual tumor volume, midline involvement) was assessed in tumors with (i) ATRX loss, and (ii) without CDKN2A homozygous deletion, lesional enhancement, histological necrosis nor microvascular proliferation.

Results

Among the 75 (64%) of tumors which had gone through observational follow-up after resection, the maximal mitotic activity, the post-surgical residual volume and the plurilobar involvement were independent prognostic factors of TTT (p &lt; 0.0001). A threshold of mitotic activity for grade 2 was fitted on TTT and OS prognosis. Using this threshold, patients with “grade 2 tumors” had a median TTT of 55 months versus 19 months for “grade 3” (p = 0.0057) and a median OS of 102 months versus 73 months respectively (p = 0.001). Residual volume &lt; 1 cm3 was associated with longer OS (113 months versus 88 months, p = 0.0021).

Conclusion

Mitotic activity and post-surgical residual volume can be combined to evaluate prognosis in resected astrocytoma IDH-mutant and could select the best candidates for observational follow-up.

Autophagy and post-ischemic conditioning in retinal ischemia

Retinal ischemia is a major cause of vision loss and a common underlying mechanism associated with diseases, such as diabetic retinopathy and central retinal artery occlusion. We have previously demonstrated the robust neuroprotection in retina induced by post-conditioning (post-C), a brief period of ischemia, 24 h, following a prolonged and damaging initial ischemia. The mechanisms underlying post-C-mediated retinal protection are largely uncharacterized. We hypothesized that macroautophagy/autophagy is a mediator of post-C-induced neuroprotection. This study employed an in vitro model of oxygen glucose deprivation (OGD) in the retinal R28 neuronal cell line, and an in vivo rat model of retinal ischemic injury. In vivo, there were significant increases in autophagy proteins, MAP1LC3-II/LC3-II, and decreases in SQSTM1/p62 (sequestosome 1) in ischemia/post-C vs. ischemia/sham post-C. Blockade of Atg5 and Atg7 in vivo decreased LC3-II, increased SQSTM1, attenuated the functional protective effect of post-C, and increased histological damage and TUNEL compared to non-silencing siRNA. TUNEL after ischemia in vivo was found in retinal ganglion, amacrine, and photoreceptor cells. Blockade of Atg5 attenuated the post-C neuroprotection by a brief period of OGD in vitro. Moreover, in vitro, post-C attenuated cell death, loss of cellular proliferation, and defective autophagic flux from prolonged OGD. Stimulating autophagy using Tat-Beclin 1 rescued retinal neurons from cell death after OGD. As a whole, our results suggest that autophagy is required for the neuroprotective effect of retinal ischemic post-conditioning and augmentation of autophagy offers promise in the treatment of retinal ischemic injury.Abbreviations: BECN1: Beclin 1, autophagy related; DAPI: 4',6-diamidino-2-phenylindole; DR: diabetic retinopathy; EdU: 5-ethynyl-2'-deoxyuridine; ERG: Electroretinogram; FITC: Fluorescein isothiocyanate; GCL: Ganglion cell layer; GFAP: Glial fibrillary acidic protein; INL: Inner nuclear layer; IPL: Inner plexiform layer; MAP1LC3/LC3: Microtubule-associated protein 1 light chain 3; OGD: Oxygen-glucose deprivation; ONL: Outer nuclear layer; OP: Oscillatory potential; PFA: Paraformaldehyde; PL: Photoreceptor layer; post-C: post-conditioning; RFP: Red fluorescent protein; RGC: Retinal ganglion cell; RPE: Retinal pigment epithelium; RT-PCR: Real-time polymerase chain reaction; SEM: Standard error of the mean; siRNA: Small interfering RNA; SQSTM1: Sequestosome 1; STR: Scotopic threshold response; Tat: Trans-activator of transcription; TUNEL: Terminal deoxynucleotidyl transferase dUTP nick end labeling.

Impaired Kupffer Cell Self-Renewal Alters the Liver Response to Lipid Overload during Non-alcoholic Steatohepatitis

Kupffer cells (KCs) are liver-resident macrophages that self-renew by proliferation in the adult independently from monocytes. However, how they are maintained during non-alcoholic steatohepatitis (NASH) remains ill defined. We found that a fraction of KCs derived from Ly-6C⁺ monocytes during NASH, underlying impaired KC self-renewal. Monocyte-derived KCs (MoKCs) gradually seeded the KC pool as disease progressed in a response to embryo-derived KC (EmKC) death. Those MoKCs were partly immature and exhibited a pro-inflammatory status compared to EmKCs. Yet, they engrafted the KC pool for the long term as they remained following disease regression while acquiring mature EmKC markers. While KCs as a whole favored hepatic triglyceride storage during NASH, EmKCs promoted it more efficiently than MoKCs, and the latter exacerbated liver damage, highlighting functional differences among KCs with different origins. Overall, our data reveal that KC homeostasis is impaired during NASH, altering the liver response to lipids, as well as KC ontogeny.

'Teach-back' is a simple communication tool that improves disease knowledge in people with chronic hepatitis B - a pilot randomized controlled study

BACKGROUND

The low diagnosis rate and poor access to clinical care among people with CHB is a major barrier to reducing HBV-related morbidity and mortality in Australia. One explanation for this is a lack of disease-specific knowledge among people living with CHB. Health literacy has been shown to be important for maximising engagement with medical care and adherence to recommended management. The 'teach-back' communication strategy has been shown to improve patient understanding in other clinical areas. This study aims to assess disease-specific knowledge; and evaluate the efficacy of the teach-back strategy for improving HBV knowledge, compared to a standard medical consultation.

METHOD

A randomized pilot study was conducted between February and June 2017. Participants were recruited from the liver clinic at an inner-city tertiary hospital. English-speaking patients aged ≥18 years and diagnosed with CHB were eligible for the study. Participants were randomised to a control group (medical specialist appointment) and intervention group (teach-back). Knowledge was assessed at baseline, immediately post-intervention and at one month using a validated questionnaire. Participants in the intervention group received a one-on-one teach-back session about CHB. The main outcome measure was a combined knowledge score of the domains assessed - transmission, natural history, epidemiology and prevention and clinical management.

RESULTS

Seventy participants were recruited (control n = 32, teach-back n = 38). Mean baseline knowledge score was 19.1 out of 23 with 55 (79%) participants scoring ≥17.3 (defined as high knowledge) (7). Sub-analysis of CHB knowledge domains identified focal deficits concerning transmission and whether HBV is curable. Knowledge scores were found to be positively associated with English proficiency and antiviral treatment experience (p < 0.05). Teach-back was associated with a significant increase in CHB knowledge at early recall (22.5 vs 18.7, p < 0.001) and at 1-month follow-up (21.9 vs 18.7, p < 0.001); there was no improvement in CHB knowledge associated with standard clinical consultant (early recall: 19.6 vs 19.4, p = 0.49, one-month follow-up: 19.5 vs 19.4, p = 0.94).

CONCLUSION

In a tertiary hospital liver clinic population, baseline knowledge about CHB was good, but there were focal deficits concerning transmission and potential for cure. Teach-back was associated with improvement in CHB knowledge and it is a simple communication tool suitable for incorporation into a standard medical consultation.

Point-of-care Hepatitis C virus testing and linkage to treatment in an Australian inner-city emergency department

BACKGROUND

In Australia, Hepatitis C Virus (HCV) treatment is declining, despite broad access to direct-acting antiviral medication. People who inject drugs are proportionally over-represented in emergency department presentations. Emergency department assessment of people who have injected drugs for HCV presents an opportunity to engage this marginalised population with treatment. We describe the outcomes of risk-based screening and point-of-care anti-HCV testing for emergency department patients, and linkage to outpatient antiviral treatment.

METHODS

During the three-month study period, consecutive adult patients who presented to the emergency department during the study times were screened for risk factors and offered the OraQuick oral HCV antibody test. Those with reactive results were offered venepuncture in the emergency department for confirmatory testing and direct-acting antiviral treatment in clinic. The main outcome measures were the number and proportion of viremic participants that were linked to the hepatitis clinic, commenced treatment and achieved a sustained viral response. Secondary outcome measures were the proportion (%) of presentations screened that were oral antibody reactive, and the prevalence and type of HCV risk factors.

RESULTS

During the study period, 2408 of the 3931 (61%) presentations to the emergency department were eligible for screening. Of these 2408 patients, 1122 (47%) participated, 307 (13%) declined participation and 977 (41%) could not be approached during their time in the emergency department. Among the 1122 participants, 378 (34%) reported at least one risk factor. Subsequently, 368 (97%) of the 378 participants underwent OraQuick anti-HCV test, and 50 (14%) had a reactive result. A risk factor of ever having injected drugs was present in 44 (88%) of participants who were sero-positive. Of the 45 that had blood tested, 30 (67%) were HCV ribonucleic acid (RNA) positive. Three participants died. Of the 27 remaining participants, 10 (37%) commenced treatment and 7 of these 10 (70%) obtained a cure. There was a high rate of homelessness (24%) among anti-HCV positive participants.

CONCLUSION

Among emergency department participants with a risk factor for HCV, positive serology was common using a rapid point-of-care test. A history of injecting drug use was identified as the risk factor with highest yield for positive HCV serology, and is suitable as a single screening question. However, linkage to care post ED presentation was low in this marginalised population. There is a need for new pathways to improve the care cascade for marginalised individuals living with HCV infection.

The Recommendation and Use of Extracorporeal Membrane Oxygenation (ECMO) in Cases Reported to the California Poison Control System

INTRODUCTION

Antidotes are available to treat some specific poisonings; however, the mainstay of treatment for the poisoned patient remains supportive care. Extracorporeal membrane oxygenation (ECMO) is one of the most aggressive supportive measures available to manage poisoned patients.

OBJECTIVE

To characterize the recommendation and use of ECMO in cases reported to the California Poison Control System (CPCS).

METHODS

This retrospective chart review queried the CPCS database from 1997 to 2016 for cases containing the American Association of Poison Control Centers (AAPCC) code for ECMO, and "ECMO" and "ECLS" free-text searches. The collected data included year, age, gender, substances involved, route of exposure, clinical effects, treatments, and medical outcome.

RESULTS

A total of 94 cases discussed ECMO as a supportive option with 16 cases utilizing ECMO. Cases where ECMO was discussed rose from one case in 1997 to 13 cases in 2016. Of the 94 cases where ECMO was discussed, 38 cases (40%) involved toxicity from a cardiovascular agent(s) and 33 cases (35%) involved exposure to hydrocarbons. Of the 16 cases where ECMO was performed, 13 (81%) involved males. The median age was 17 years (range 1 month-54 years). Ten cases (63%) involve patients under the age of 18. In this series, 13 of 16 ECMO-supported patients survived (81%).

CONCLUSIONS

ECMO is being recommended more often for treatment of acute poisoning cases by the CPCS. All caregivers involved in the treatment of poisoning should gain a working knowledge of the potentially lifesaving technology of ECMO, its indications for use, adverse effects, and drug or poison interactions.

Selecting for a sustainable workforce to meet the future healthcare needs of rural communities in Australia

An undersupply of generalists doctors in rural communities globally led to widening participation (WP) initiatives to increase the proportion of rural origin medical students. In 2002 the Australian Government mandated that 25% of commencing Australian medical students be of rural origin. Meeting this target has largely been achieved through reduced standards of entry for rural relative to urban applicants. This initiative is based on the assumption that rural origin students will succeed during training, and return to practice in rural locations. One aim of this study was to determine the relationships between student geographical origin (rural or urban), selection scores, and future practice intentions of medical students at course entry and course exit. Two multicentre databases containing selection and future practice preferences (location and specialisation) were combined (5862), representing 54% of undergraduate medical students commencing from 2006 to 2013 across nine Australian medical schools. A second aim was to determine course performance of rural origin students selected on lower scores than their urban peers. Selection and course performance data for rural (461) and urban (1431) origin students commencing 2006-2014 from one medical school was used. For Aim 1, a third (33.7%) of rural origin students indicated a preference for future rural practice at course exit, and even fewer (6.7%) urban origin students made this preference. Results from logistic regression analyses showed significant independent predictors were rural origin (OR 4.0), lower Australian Tertiary Admissions Rank (ATAR) (OR 2.1), or lower Undergraduate Medical and Health Sciences Admissions Test Section 3 (non-verbal reasoning) (OR 1.3). Less than a fifth (17.6%) of rural origin students indicated a preference for future generalist practice at course exit. Significant predictors were female gender (OR 1.7) or lower ATAR (OR 1.2), but not rural origin. Fewer (10.5%) urban origin students indicated a preference for generalist practice at course exit. For Aim 2, results of Mann-Whitney U tests confirmed that slightly reducing selection scores does not result in increased failure, or meaningfully impaired performance during training relative to urban origin students. Our multicentre analysis supports success of the rural origin WP pathway to increase rural student participation in medical training. However, our findings confirm that current selection initiatives are insufficient to address the continuing problem of doctor maldistribution in Australia. We argue for further reform to current medical student selection, which remains largely determined by academic meritocracy. Our findings have relevance to the selection of students into health professions globally.

Vietnamese community screening for hepatitis B virus and hepatitis C virus

Asian Americans represent an important cohort at high risk for viral hepatitis. To determine the prevalence of Hepatitis B virus (HBV) and Hepatitis C virus (HCV) infection and HBV vaccination in a Vietnamese community, a total of 322 Vietnamese subjects from a local doctor's office and annual Vietnamese Health Fair were included in this study. Demographic and clinical data were collected. 2.2% of the screened cohort tested positive for anti-HCV and 9.3% tested positive for HBsAg. Unlike HBV-positive subjects, HCV-positive subjects had significantly higher liver enzymes (P = 0.0045 and P = 0.0332, respectively). The HBV-positive group was more likely to report jaundice (P = 0.0138) and a family history of HBV (P = 0.0115) compared to HBV-negative subjects. Forty-eight patients (15.5%) reported a family history of liver disease (HBV, HCV, HCC, cirrhosis, other). Of this 48, 68.8% reported no personal history of HBV vaccination and 77.1% reported no family history of vaccination for HBV. Among the 183 subjects without a family history of liver disease, 156 (85.2%) reported no personal history of vaccination and 168 (91.8%) reported no family history of vaccination. HBV vaccination rates in those reporting a family history of liver disease were significantly higher (P =0.020). There was a high prevalence of HBV infection in this community screening. Nevertheless, the rate for HBV vaccination was low. The low prevalence of abnormal liver enzymes in HBV-positive subjects emphasizes the need for screening to be triggered by risk factors and not by abnormal liver enzymes.

Novel APC-cleavage sites in FVa provide insights into mechanisms of action of APC and its cofactor protein S

BACKGROUND

Activated protein C (APC) inhibits factor Va (FVa) by cleaving at Arg306, Arg506 and Arg679. Protein S serves as cofactor, in particular for the Arg306 site, and a protein S-mediated relocation of the active site of APC closer to the membrane has been proposed as a mechanism. Recently, it was demonstrated that FVa, which was mutated at all three APC-cleavage sites (FVa-306Q/506Q/679Q), could still be cleaved by APC. These sites were close to Arg306 and Arg506 but not further defined.

OBJECTIVE

To identify and characterize the additional APC-cleavage sites in FVa.

METHODS

The cDNA for FV-306Q/506Q/679Q was used as a template to create FV variants with one or more possible cleavage sites being mutated. The FV variants were expressed and their sensitivity for APC characterized functionally and with Western blotting.

RESULTS

The additional APC-cleavage sites were located at Lys309, Arg313, Arg316, Arg317 and Arg505. FVa-306Q/309Q/313Q/316Q/317Q/505Q/506Q/679Q (denoted 8M-FVa) was APC resistant. To investigate individual sites, they were mutated back using 8M-FV as a template. The kinetics of APC-degradation of these variants demonstrated that protein S was equally efficient in enhancing the APC effect for all the novel sites.

CONCLUSIONS

Multiple APC-cleavage sites close to Arg306 and a single site close to Arg506 were identified. Protein S was equally efficient as APC cofactor for all novel sites. The stimulation by protein S of the Arg505 cleavage argues against a specific protein S-mediated stimulation of cleavage at Arg306 due to relocation of the APC active site closer to the membrane.

Does donating blood for the first time during a national emergency create a better commitment to donating again?

BACKGROUND AND OBJECTIVES

Emergency situations often elicit a generous response from the public. This occurred after attacks on the US on September 11, 2001 when many new blood donors lined up to donate. This study was performed to compare return rates for first time donors (FTD) after September 11th, 2001 to FTD during a comparable period in 2000.

MATERIALS AND METHODS

A total of 3315 allogeneic whole blood donations from FTD at a regional blood centre were collected between September 11th and 30th, 2001. Subsequent donations by the FTD before March 31, 2002 were reviewed. This (test) group was compared to 1279 FTD (control group) donating during the same time period in September 2000 and to their return rate in the subsequent 6 months.

RESULTS

Following September 11, 2001, 1087/3315 (32.8%) FTD returned by March 31, 2002. This return rate was similar to the control group [427/1279 (33.4%)]. The deferral rate during the donor screening process for the control group was significantly higher than the deferral rate for the September 11-30, 2001 group (P < 0.01). The odds of an individual FTD returning increased with age, and the chance of a female donor returning was 1.13 times higher than a male (P = 0.06). There was a carryover effect after September 11, 2001 too.

CONCLUSION

A national emergency, September 11, 2001, inspired people to donate blood for the first time. However, the proportion of return donations amongst them was not increased. Females and males in certain age groups were more likely to become repeat donors due to the residual effect of September 11, 2001. Additional efforts are needed to retain eligible FTD in donor pools.

Catalase overexpression attenuates angiotensinogen expression and apoptosis in diabetic mice

Increased generation of reactive oxygen species (ROS) leads to oxidative stress in diabetes. Catalase is a highly conserved heme-containing protein that reduces hydrogen peroxide to water and oxygen and is an important factor decreasing cellular injury owing to oxidative stress. Hyperglycemic conditions increase oxidative stress and angiotensinogen gene expression. Angiotensinogen conversion to angiotensin II leads to a furtherance in oxidative stress through increased generation of reactive oxygen species. In this study, we utilized mice transgenically overexpressing rat catalase in a kidney-specific manner to determine the impact on ROS, angiotensinogen and apoptotic gene expression in proximal tubule cells of diabetic animals. Proximal tubules isolated from wild-type and transgenic animals without or with streptozotocin-induced diabetes were incubated in low glucose media in the absence or presence of angiotensin II or in a high-glucose media. Our results show that the overexpression of catalase prevents the stimulation of ROS and angiotensinogen mRNA in tubules owing to elevated glucose or angiotensin II in vitro. Additionally, overexpression of catalase attenuated ROS generation, angiotensinogen and proapoptotic gene expression and apoptosis in the kidneys of diabetic mice in vivo. Our studies point to an important role of ROS in the pathophysiology of diabetic nephropathy.

Reactive oxygen species and nuclear factor-kappa B pathway mediate high glucose-induced Pax-2 gene expression in mouse embryonic mesenchymal epithelial cells and kidney explants

Diabetic mellitus confers a major risk of congenital malformations, and is associated with diabetic embryopathy, affecting multiple organs including the kidney. The DNA paired box-2 (Pax-2) gene is essential in nephrogenesis. We investigated whether high glucose alters Pax-2 gene expression and aimed to delineate its underlying mechanism(s) of action using both in vitro (mouse embryonic mesenchymal epithelial cells (MK4) and ex vivo (kidney explant from Hoxb7-green florescent protein (GFP) mice) approaches. Pax-2 gene expression was determined by reverse transcriptase-polymerase chain reaction, Western blotting, and immunofluorescent staining. A fusion gene containing the full-length 5'-flanking region of the human Pax-2 promoter linked to a luciferase reporter gene, pGL-2/hPax-2, was transfected into MK4 cells with or without dominant negative IkappaBalpha (DN IkappaBalpha) cotransfection. Fusion gene expression level was quantified by cellular luciferase activity. Reactive oxygen species (ROS) generation was measured by lucigenin assay. Embryonic kidneys from Hoxb7-GFP mice were cultured ex vivo. High D(+) glucose (25 mM), compared to normal glucose (5 mM), specifically induced Pax-2 gene expression in MK4 cells and kidney explants. High glucose-induced Pax-2 gene expression is mediated, at least in part, via ROS generation and activation of the nuclear factor kappa B signaling pathway, but not via protein kinase C, p38 mitogen-activated protein kinase (MAPK), and p44/42 MAPK signaling.

Retrospective study of clinical and radiographic risk factors associated with early onset, severe pulmonary hemorrhage in bevacizumab-treated patients with advanced non-small cell lung cancer (NSCLC)

7068

Background: Bevacizumab (BV) added to chemotherapy prolongs survival in non-squamous NSCLC, but was uncommonly associated with serious pulmonary hemorrhage (PH) (Sandler A, et al, ASCO 2005). A retrospective study was conducted to potentially identify clinical or radiographic (CT) risk factors associated with early onset (<150 days from initial treatment) PH. Methods: A broad search of the E4599 database for selected bleeding terms among BV-treated patients was conducted. Cases of PH were identified and adjudicated. Associations between baseline clinical factors and incidence of PH were evaluated in the full cohort of E4599 patients. In addition, a separate case-control analysis, using controls matched on age and sex, was conducted to evaluate baseline CT variables. Chest CTs were evaluated by blinded independent assessment of lesion location, cavitation, size of largest tumor or nodal mass, vascular involvement, presence of an endobronchial tumor, and total number of intra-thoracic lesions. Additional analyses were also conducted including cases of late-onset PH, post-baseline variables such as unconfirmed tumor response at 6 weeks (RECIST) and cavitation, and combined CT data from E4599 and an earlier Ph II trial. Results: Of 425 BV-treated pts, 10 cases of PH were identified. Of these, 7 were PH without additional complicating factors, and 6 were of early-onset. The cohort analysis of these 6 early-onset cases is presented ( table ). The case-control analysis on CT risk factors is ongoing. Conclusion: PH was an uncommon event, and based on this, no evidence was observed for an association between the baseline clinical variables and the incidence of early-onset events of PH without additional complicating factors. Conclusions for the CT variables evaluated will be presented.

[Table: see text]

[Table: see text]

Helicobacter DNA in bile: correlation with hepato-biliary diseases

BACKGROUND

Helicobacter has been identified in isolated cases of hepato-biliary diseases, but its role in the pathogenesis of these conditions remains unclear.

AIM

To determine whether Helicobacter could be detected in bile obtained at endoscopic retrograde cholangiopancreatography, and to evaluate the prevalence of this infection in patients with hepato-biliary diseases.

METHODS

Bile was collected from 125 patients with various hepato-biliary diseases undergoing endoscopic retrograde cholangiopancreatography. Among them, 75 were diagnosed with biliary stones, 15 with pancreatico-biliary malignancies and four with primary sclerosing cholangitis. The detection of Helicobacter in DNA extracted from these bile samples was performed using Helicobacter genus-specific primers (capable of detecting 100-1000 organisms/mL).

RESULTS

Helicobacter was detected in all positive controls. Only three samples had polymerase chain reaction inhibitors. All remaining bile samples (122 patients with hepato-biliary diseases) were negative for Helicobacter DNA.

CONCLUSIONS

Helicobacter can be detected in bile samples using polymerase chain reaction. This infection, however, was not present in any of our patients diagnosed with gallstones or hepato-biliary malignancies, raising doubt as to the possible association between Helicobacter and these entities. Given the low sample size of patients with primary sclerosing cholangitis, more studies are required to determine whether an association exists with this condition.

Recurrent and de novo diabetic nephropathy in renal allografts

BACKGROUND

Histologic findings of diabetic nephropathy (DN) are observed in allografts of patients with pretransplant (PreTx) diabetes mellitus (DM) and in patients who develop DM posttransplant (PostTx). Patients with allograft biopsies (Bx) were retrospectively studied to determine the incidence of recurrent and de novo DN and to ascertain what, if any, risk factors predispose to histologic DN in either patient population.

METHODS

From the renal transplant services at four hospitals from 1992 to 2000, the authors identified all patients with PreTxDM and PostTxDM (n=81). Those with renal biopsies performed >/=18 months PostTx were classified according to the presence or absence of histologic DN (Bx-positive, n=23; Bx-negative, n=35). Patients were then subdivided into four categories-recurrent DN (n=16), de novo DN (n=7), no recurrent DN (n=27), and no de novo DN (n=8)-for analyses.

RESULTS

Among these 58 patients, 74.1% had PreTx and 25.9% had PostTx diabetes. Of those with histologic DN, 69.6% were recurrent DN and 30.4% were de novo DN, making de novo DN at least as likely to develop as recurrent DN. After the onset of diabetes in the de novo population, the time to development of histologic DN was similar in the recurrent and the de novo patients (6.68+/-3.86 years vs. 5.90+/-3.13 years, P=0.66) and more rapid than previously reported. Apart from a more frequent family history of hypertension in patients with allograft DN compared with those without allograft DN, known risk factors for the development of native DN did not significantly differ among patients in the four cohorts. Proposed risk factors related to transplantation did not correlate with the development of recurrent or de novo DN.

CONCLUSION

Among patients with histologic DN, de novo DN occurred at least as frequently as recurrent DN, and the time to onset of histologically apparent DN was more rapid than previously reported. Neither the usual clinical predictors of DN nor clinical variables related to transplantation clearly distinguished the group with DN from the group without it, potentially implicating novel mechanisms in its pathogenesis.

Functional characterization of domains found within a lytic enzyme produced by Streptococcus equi subsp. zooepidemicus

Zoocin A is a lysostaphin-like streptococcolytic enzyme produced by Streptococcus equi subsp. zooepidemicus 4881 that specifically targets the cell walls of some closely related species. On the basis of sequence homology it was suggested that zoocin A was a domain-structured enzyme with the N-terminal domain responsible for catalysis (CAT) and the C-terminal domain for target recognition (SBD). Polypeptides corresponding to zoocin A (rZooA) and each of the putative domains (rCAT and rSBD) were prepared by use of recombinant technology. The biological activities of each was compared by use of a dye-release assay and a cell-binding assay. Cell wall hydrolysis was shown to be a function of CAT and target recognition a function of the SBD. Expression of the zoocin A immunity factor gene produced cell walls resistant to hydrolysis by either rZooA or its component domains, and with reduced capacity to bind rZooA and rSBD.

The effects of continuous 5-HT(3) receptor antagonist administration on the subsequent behavioral response to cocaine

A functional down-regulation of central serotonin3 (5-HT(3)) receptors represents a partial mechanism of the tolerance to cocaine induced by the continuous administration of cocaine. Blocking this down-regulation by co-administering continuous cocaine and daily injections of 5-HT(3) receptor antagonists blocks the development of tolerance. The present experiment evaluated the ability of continuously administered 5-HT(3) receptor antagonists, to induce sensitization (reverse tolerance) to the behavioral effects of cocaine, based on the hypothesis that chronic blockade of 5-HT(3) receptors should induce an up-regulation of these receptors. In all experiments, rats received a 14 day pretreatment involving the continuous administration of tropisetron (0.0, 1.0, 4.0, or 8.0 mg/kg/day) or LY 278584 (0.001, 0.01, or 0.1 mg/kg/day). The rats were withdrawn for 7 days from this pretreatment regimen. On day 7 of withdrawal from the pretreatment regiment, the rats received a 0.0, 7.5, or 15.0 mg/kg i.p. cocaine challenge. Ambulatory behavior was automatically recorded for 60 min. Both continuous tropisetron and LY 278584, opposite to the initial hypothesis, induced tolerance, and not sensitization, to the behavioral effects of cocaine. The results clearly indicate that central 5-HT(3) receptors are critical for the effects of chronic cocaine administration.

The effects of continuous cocaine duration on the induction of behavioral tolerance and dopamine autoreceptor function

The current experiment evaluated the duration-dependent nature of the induction of behavioral tolerance and changes in dopamine autoreceptor function by continuously administering cocaine for different durations. For all experiments, rats were exposed to a pretreatment regimen involving the continuous administration of 40 mg/kg/day cocaine. The pretreatment regimen lasted 3, 7, or 14 days. All subjects were then withdrawn from the pretreatment regimen for 7 days. The subjects were placed in activity monitors and ambulation measured. In experiment 1, the subjects were challenged with 0.0, 7.5, or 15.0 mg/kg i.p. cocaine on day 7 of withdrawal from the continuous cocaine administration regimen. The results indicated that all continuous cocaine durations induced significant tolerance to the 7.5 and 15.0 mg/kg cocaine challenge, relative to the control group. However, the magnitude of tolerance was not duration dependent. In experiment 2, the subjects were challenged with 0.063 or 0.125 mg/kg quinpirole. The results indicated that the 0.063 mg/kg quinpirole challenge inhibited activity in both pretreatment groups, while the 0.125 mg/kg quinpirole challenge enhanced behavior in the saline control, but not the cocaine, pretreatment group. In experiment 3, the subjects were challenged with the same doses of quinpirole in combination with 7.5 mg/kg i.p. cocaine. Both quinpirole challenge doses inhibited cocaine-induced hyperactivity. The results suggest that the induction of tolerance by continuous cocaine administration is not duration-dependent. Continuous cocaine administration did induce dopamine autoreceptor supersensitivity. Different continuous cocaine durations may induce differential degrees of dopamine autoreceptor supersensitivity.

The geochemistry of mercury in central Amazonian soils developed on the Alter-do-Chão formation of the lower Tapajós River Valley, Pará state, Brazil

In an oxisol-spodosol system developed on the terrestrial surface of the lower Tapajós Valley, the determination of total mercury (Hg), organic carbon (C), iron and aluminum oxy-hydroxide (Fe(cdb) and Al(cdb)) concentrations in the surface soil horizons are used to characterise the geochemical processes controlling the accumulation of Hg in soils under natural vegetation cover and in deforested and cultivated sites. Oxisols from the plateau have homogeneous and relatively high background Hg contents and burdens constituting an important natural reservoir of Hg for the region (90-210 ng/g dry wt. and 19-33 mg/m2 for the first 20 cm). The Fe(cdb) and Al(cdb) contents associated with the fine fraction (< 63 microns) of the soil suggest that oxy-hydroxides and, particularly Al-substituted Fe oxy-hydroxides, control the Hg concentrations observed in all of the soils of the study region. Consequently, the geochemistry of these minerals along the slopes governs the accumulation or the release of the Hg according to the natural evolution of the soil cover and/or following the degradation of soils by erosion after deforestation and cultivation. These observations have important implications for the interpretation of Hg contamination patterns observed in Amazonian aquatic systems that could be linked to different drainage sources of Hg from the terrestrial surface. The sandification and podzolisation that is characteristic of the evolution of numerous pedological systems in the equatorial Amazon could be responsible for exportation of the naturally accumulated Hg, as for other metals, by acidic complexation and migration to the black waters of the Amazon. In the central Amazon region, as a result of the fragility of the soil cover, deforestation and cultivation, affecting principally the superficial soil, promote the selective erosion of fine particles enriched in oxides and Hg. The erosion of soil could be responsible for an important release of Hg, transported in particulate form by drainage waters.

Overexpression of metallothionein decreases sensitivity of pulmonary endothelial cells to oxidant injury

Metallothionein (MT) is a low-molecular-weight cysteine-rich protein with extensive metal binding capacity and potential nonenzymatic antioxidant activity. Despite the sensitivity of vascular endothelium to either heavy metal toxicity or oxidative stress, little is known regarding the role of MT in endothelial cells. Accordingly, we determined the sensitivity of cultured sheep pulmonary artery endothelial cells (SPAEC) that overexpressed MT to tert-butyl hydroperoxide (t-BOOH), hyperoxia, or 2,2'-azobis(2,4-dimethylvaleronitrile) (AMVN; peroxyl radical generator). Nontoxic doses of 10 microM Cd increased MT levels from 0.21 +/- 0.03 to 2.07 +/- 0.24 microg/mg and resulted in resistance to t-BOOH and hyperoxia as determined by reduction of Alamar blue or [3H]serotonin transport, respectively. SPAEC stably transfected with plasmids containing either mouse or human cDNA for MT were resistant to both t-BOOH and hyperoxia. In addition, we examined transition metal-independent, noncytotoxic AMVN-induced lipid peroxidation after metabolic incorporation of the oxidant-sensitive fluorescent fatty acid cis-parinaric acid into phospholipids and high-performance liquid chromatography separation. SPAEC that overexpressed MT after gene transfer completely inhibited peroxyl oxidation of phosphatidylserine, phosphatidylcholine, and sphingomyelin (but not phosphatidylethanolamine) noted in wild-type SPAEC. These data show for the first time that MT can 1) protect pulmonary artery endothelium against a diverse array of prooxidant stimuli and 2) directly intercept peroxyl radicals in a metal-independent fashion, thereby preventing lipid peroxidation in intact cells.

Differential effects of voltage-dependent Ca2+ channels on low and high frequency mediated neurotransmission in guinea-pig ileum and rat vas deferens

The omega-conotoxins GVIA, MVIIA, MVIIC and SVIB reduced in a concentration-dependent manner the low frequency electrically stimulated twitch response of the guinea-pig ileum and rat vas deferens. The relative activities of the conotoxins showed some difference between the two preparations in that for ileum it was MVIIA = GVIA > MVIIC = SVIB and for the vas deferens it was MVIIA > GVIA >> SVIB > MVIIC. High frequency electrical stimulation of both preparations resulted in a neurally-mediated omega-conotoxin GVIA resistant component that was sensitive to high concentrations of either omega-conotoxin MVIIC (300 nM- 1 microM) or omega-agatoxin IVA (300 nM-1 microM) but not to omega-conotoxin MVIIA. Lower levels of either omega-conotoxin MVIIC or omega-agatoxin IVA (30-100 nM) failed to significantly affect the omega-conotoxin GVIA resistant component. This omega-conotoxin GVIA resistant component was large in the ileal preparation comprising 30-40% of the maximal response at 20 Hz but relatively small (10%) in the vas deferens. These studies revealed that the N-type voltage-dependent calcium channel (VDCCs) exclusively controls neurotransmission during low frequency stimulation but at higher frequencies there is an additional non-adrenergic, non-cholinergic (NANC) neurotransmission that appears to be regulated via Q-type VDCC.

The use of cryopreserved microvenous allografts in the venous system without immunosuppression: an experimental study

Autogenous vein grafts are currently the number one choice in microsurgical practice for managing vessel length discrepancies. A significant percentage of these grafts is used in the venous system. Allografts may serve as a viable alternative source of vein grafts. Few studies in the past have described the use of cryopreserved vein grafts (1 mm in diameter) in the venous system. In the present study, we cryopreserved the femoral veins of rats and transplanted these across rat species (ACI to Lewis) as interpositional vein grafts into a defect in the femoral vein. Short-term patencies (21 days), expressions of systemic antigenicity, histology, and scanning electron microscopic studies were performed. We obtained 100% patencies with fresh control veins and cryopreserved veins at 21 days.

Serum hepatitis C RNA titers after liver transplantation are not correlated with immunosuppression or hepatitis

The degree to which immunosuppression and/or rejection influences recurrent hepatitis C (HCV) after liver transplantation (LT) for end-stage HCV cirrhosis remains poorly defined. We quantified serum HCV-RNA in 84 serum samples from 28 anti-HCV-positive patients taken 223 days prior to and up to 1719 days after liver transplantation to determine if cumulative immunosuppression, rejection, or histologic recurrence correlated with HCV-RNA levels. Histologic, serum chemistry, cumulative steroid, and OKT3 and alpha-interferon (INF) dose data were collected at the time of HCV-RNA sampling. Eighteen of 24 evaluable patients (75%) had HCV-RNA detected in their sera after transplant. Eight patients had 14 rejection episodes, 9 patients received OKT3, and 5 were given INF for histologically moderate hepatitis. Five patients died - two of recurrent hepatitis C - and no retransplants were performed for recurrent hepatitis. Of the 23 survivors, 7 have histologic hepatitis - 2 with persistent ascites, and 2 with mild fibrosis. We could show no correlation between HCV-RNA levels and any of the variables examined although a trend toward increasing HCV-RNA levels with increasing numbers of rejection episodes was observed. In addition, histologic recurrence occurred more frequently for patients treated with OKT3. We conclude that the quantity of circulating viral genome is not influenced by immunosuppressive load and does not correlate with laboratory or histologic signs of recurrence. The roles that rejection, and possibly OKT3, play in the recurrence of HCV after liver transplant need further study.

Characterization of nuclear factors that bind to a critical positive regulatory element of the human granulocyte-macrophage colony-stimulating factor promoter

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a hematopoietic growth factor that stimulates the proliferation, maturation, and functional activity of myeloid cells in peripheral blood and bone marrow. Expression of GM-CSF is tightly regulated and is limited to cells stimulated directly (T cells, macrophages) or indirectly (fibroblasts, endothelial cells) by immune challenge. Several studies of the transcriptional control of GM-CSF expression have elucidated a region of the GM-CSF promoter that mediates positive regulatory activity in a number of cell types. This region contains a direct repeat of the sequence CATTA/T that extends from nucleotides -37 to -48 upstream of the start of mRNA synthesis. Although specific DNA:protein interactions have been shown within this region, neither the nature nor the number of nuclear factors responsible for these interactions have been characterized. In this study, we use DNase I footprinting analysis to demonstrate that point mutations, which inactivate the GM-CSF promoter, disrupt DNA:protein interactions within this region. By combined electrophoretic mobility shift and ultraviolet cross-linking analysis, we have detected several protein species that bind specifically to the positive regulatory sequence.

Prevalence of hepatitis C virus infection in asymptomatic anti-HIV1 negative pregnant women and their children

The prevalence of hepatitis C virus (HCV) infection was studied prospectively in pregnant women in France and their children by detection of anti-HCV with second-generation ELISA (ELISA2). In ELISA2-positive women, anti-HCV was detected with second- and third-generation RIBA (RIBA2 and RIBA3) and serum HCV RNA was detected with PCR. Among 670 women, anti-HIV1-negative, 26 (3.9%) were positive with ELISA2. RIBA2 was positive in 13 and HCV RNA was found in 10. Ten ELISA2-positive women had a further evaluation with assessment of HCV infection in their children. Among the 10 children born to the index pregnancy, only one was positive with ELISA2 and RIBA2 but negative with RIBA3 and PCR; the nine other children were ELISA2, RIBA2, RIBA3, and PCR negative. All 26 siblings (2-16 years old), of whom 14 were born to PCR-positive mothers, were ELISA2 and RIBA2 negative. We conclude that among anti-HIV1-negative pregnant women with normal serum ALT levels, the prevalence of HCV infection is relatively high but the risk for mother-to-infant transmission of HCV seems to be low.

Return to work for persons following severe traumatic brain injury. Supported employment outcomes after five years

Supported employment is a recently developed rehabilitation alternative that is being used to assist individuals with traumatic brain injury to return to work. The present study reports the results of a supported employment program that has placed 80 individuals into competitive employment during a 5-year time period. All individuals had sustained a severe traumatic brain injury; 72% of the injuries involved a motor vehicle. A mean of 6.1 years had passed since injury for all participants, who had been unconscious an average of 48 days. Neuropsychologic evaluation revealed defective cognitive functioning, which contributed to diminished employment potential. A key outcome indicator used to assess return to work capacity is the monthly employment ratio, which is computed by dividing the number of months employed during an employment phase (i.e., pre/post injury) by the total possible months an individual would have the opportunity to be employed. The monthly employment ratio increased from 13% after injury with no supported employment to 67% with supported employment services. The majority of individuals were employed in warehouse, clerical and service-related occupations. A mean of 250 staff intervention hours were required to train and provide follow-up services to program participants.

The use of cryopreserved venous allografts in microvascular surgery without immunosuppression: an experimental study

Excellent patency rates are currently established in the use of autogenous veins as interposition vein grafts in microsurgical practice. Allografts may be a viable alternative source of vein grafts. Recent advances in cryobiology have enabled the controlled freezing of tissues with preservation of vital cellular elements. Although several reports have shown the successful use of cryopreserved large-vessel allografts, few have addressed cryopreservation of microvessels (1 to 2 mm in diameter). In this study, the authors have successfully cryopreserved femoral veins in a rat model and transplanted them as interposition vein grafts into arterial defects across major histocompatibility barriers (ACI to Lewis). Short-term patencies (21 days) were determined, and histologic and scanning electron microscopic analysis were performed. Patency of 100 percent was achieved in both fresh control veins and in cryopreserved veins at 21 days.

The nonreciprocating robot: effects on verbal discourse, social play, and social referencing at two years of age

2-year-old children interacted with a robot in a large playroom while their mother sat quietly in the corner. Identical vocalizations from the robot had very different effects on 3 dimensions of the children's behavior when the vocalizations were embedded in reciprocating and nonreciprocating social structures. The reciprocating robot produced (1) more topic-maintaining verbal dialogue, (2) less physical and more linguistically mediated social play, and (3) gender-specific effects on the children's tendency to visually reference their mother during the play session. The data are discussed with reference to the frequently encountered assumption that reciprocal social structures have an impact on children's behavior when the quantity and other qualitative dimensions of social stimulation are held constant, and with reference to the children's attributions about the robot as a social partner.

Growth of the clavicle and development of clavicular secondary cartilage in the embryonic mouse

Whether secondary cartilage develops in the mammalian clavicle has been a matter of controversy. This study documents, in the embryonic mouse: (a) the onset of clavicular osteogenesis at 14 days of gestation (Theiler stage 22); (b) the appearance of secondary cartilage at 16 days of gestation (Theiler stage 24) and its persistence as a prominent cartilage until 18 days of gestation; (c) that the relative growth rate of the clavicle is much higher (0.097 mg/g body weight/day) between 16 and 17 days of gestation than at later ages (mean of 0.005 mg/g/day between 17 days of gestation and 4 days postnatally), and (d) that secondary cartilage failed to form in clavicles from 15-day-old embryos maintained in vitro. We conclude that secondary cartilage is a feature of the developing mouse clavicle, that it arises when the relative growth rate of the clavicle is highest, and that the most likely stimulus for differentiation of this cartilage is mechanical, muscle-based and associated with rapid relative clavicular growth.