CT-based sarcopenia and outcomes in patients undergoing VATS anatomical resection for NSCLC

Objective

Sarcopenia is defined by a progressive loss of skeletal muscle mass and strength, combined with muscle fatty infiltration. Lung cancer patients frequently suffer from sarcopenia which may be associated with poorer post-operative outcomes. The aim of this study is to evaluate whether preoperative CT-based sarcopenia was associated with postoperative outcomes and survival after VATS resections in patients with early-stage non-small cell lung cancer (NSCLC).

Methods

We retrospectively reviewed all consecutive patients that underwent anatomical resection for NSCLC between 2012 and 2019. The skeletal muscle index (SMI) and muscle quality (SMRA and IMAT) were measured at the L3 vertebral level on preoperative CT or PET/CT scans. We used the following SMI cut-off values for sarcopenia: 52.4 cm2 /m2 for men and 38.5 cm2 /m2 for women.

Results

In total, 401 patients (sex ratio F/M: 173/228, mean age: 67 +/- 9.3 years) underwent VATS lobectomies (n=304) and segmentectomies (n=97) for NSCLC. Overall morbidity and mortality were 42.4% and 0.2%, respectively. The median length of stay was 7 days (IQR: 4–10). Sarcopenia was identified in 92 patients (23%). Patients with sarcopenia were predominantly males (75% vs 25%, p<0.001) and had lower BMI (21.4 vs 26.5, p<0.001). Patients with sarcopenia presented significantly increased morbidity (53.2% vs 39.2%, p=0.017) and had longer lengths of stay (6 vs 8 days, p=0.032). However, only lower BMI and ASA score >2 remained associated with increased morbidity on multivariate analysis. The median overall survival was comparable between patients with sarcopenia and those without sarcopenia (41 vs. 46 months, p=0.240).

Conclusion

Based on CT assessment alone, preoperative sarcopenia appeared to have little impact on postoperative clinical outcomes or overall survival in patients undergoing VATS pulmonary resection. Further studies should also consider muscle strength and physical performance, in addition to CT imaging, for preoperative risk assessment.

Local control and short-term outcomes after VATS segmentectomy vs lobectomy for pT1c pN0 NSCLC (2–3 cm)

Objective

Pulmonary segmentectomy has shown comparable oncological results to lobectomy for non-small cell lung cancers (NSCLC) of less than 2 cm. However, controversy remains for tumors of larger size. The aim of this study was to compare short-term outcomes and local control in pT1c pN0 NSCLC that were intentionally treated by VATS segmentectomy or lobectomy.

Methods

Multicenter retrospective study from January 2014 to October 2021 of 162 consecutive patients undergoing complete (R0) anatomical resections for pT1c pN0 NSCLC. Two groups, VATS lobectomy (VL) or VATS segmentectomy (VS) were defined according to the extension of the resection. Patients’ characteristics, postoperative outcomes and survival were compared.

Results

In total, 162 patients underwent VL (n=81) or VS (n=81). Except for age (median of 68 vs 71 years, p=0.034) and past medical history of cancer (32% vs 48%, p=0.038), there was no difference between VL and VS in terms of demographics and comorbidities (table1). Segmentectomies were performed in upper lobes in 68% and single segments represented 46% of all cases. Conversion thoracotomy rate was 5% in both groups. Morbidity were similar in both groups (34% vs 30%, p=0.5). The median time for chest tube removal (3 vs 2 days, p=0.002) and median LOS (6 vs 5 days, p=0.039) were in favor of the VS group. Significantly larger tumor (25 mm vs 23.5 mm p=0.001) and an increased number of lymph nodes removal (median 14 vs 10, p<0.001) were found in the VL group. During the follow-up (median: 31 months), no statistical difference was found for local and distant recurrence in VL groups (12.3%) and VS group (6.2%) (p=0.414). Overall survival was comparable in-between both groups (p=0.166).

Conclusion

Despite a short follow-up, our preliminary data shows that local control is comparable for VATS lobectomy and VATS segmentectomy. Further prospective randomized trials are needed to corroborate these results.

Instant Visual Odometry Initialization for Mobile AR

Mobile AR applications benefit from fast initialization to display world-locked effects instantly. However, standard visual odometry or SLAM algorithms require motion parallax to initialize (see Figure 1) and, therefore, suffer from delayed initialization. In this paper, we present a 6-DoF monocular visual odometry that initializes instantly and without motion parallax. Our main contribution is a pose estimator that decouples estimating the 5-DoF relative rotation and translation direction from the 1-DoF translation magnitude. While scale is not observable in a monocular vision-only setting, it is still paramount to estimate a consistent scale over the whole trajectory (even if not physically accurate) to avoid AR effects moving erroneously along depth. In our approach, we leverage the fact that depth errors are not perceivable to the user during rotation-only motion. However, as the user starts translating the device, depth becomes perceivable and so does the capability to estimate consistent scale. Our proposed algorithm naturally transitions between these two modes. Our second contribution is a novel residual in the relative pose problem to further improve the results. The residual combines the Jacobians of the functional and the functional itself and is minimized using a Levenberg-Marquardt optimizer on the 5-DoF manifold. We perform extensive validations of our contributions with both a publicly available dataset and synthetic data. We show that the proposed pose estimator outperforms the classical approaches for 6-DoF pose estimation used in the literature in low-parallax configurations. Likewise, we show our relative pose estimator outperforms state-of-the-art approaches in an odometry pipeline configuration where we can leverage initial guesses. We release a dataset for the relative pose problem using real data to facilitate the comparison with future solutions for the relative pose problem. Our solution is either used as a full odometry or as a pre-SLAM component of any supported SLAM system (ARKit, ARCore) in world-locked AR effects on platforms such as Instagram and Facebook.

Is faster better? Impact of operative time on postoperative outcomes after VATS anatomical pulmonary resection

Objective

Video-Assisted Thoracic Surgery (VATS) is now the preferred approach for standard anatomical pulmonary resections. However, operative time (OT) for this technique is correlated to many aspects, such as the surgical complexity or the surgeon’s experience and skills. The aim of this study was to identify the factors associated with prolonged OTs and to assess the impact of OT on the development of post-operative complications after VATS anatomical pulmonary resections.

Methods

Retrospective monocentric study including all consecutive patients undergoing a VATS anatomical pulmonary resection for benign or malignant lesions between January 2010 and December 2019. Postoperative outcomes were compared between short (<150 minutes) and long (≥150 minutes) OTs. A multivariate analysis was carried out to identify predictors of longer OTs and post-operative complications.

Results

A total of 836 patients underwent a VATS anatomical pulmonary resection for malignant (n = 767, 91.7%) or benign (n = 69, 8.3%) lesions. Lobectomies were performed in 555 (66.4%), segmentectomies in 250 (29.9%), sleeve lobectomies in 16 (1.9%), bilobectomies in 11 (1.3%) and pneumonectomy in 4 (0.5%) patients. The conversion rate to thoracotomy was 7.7%. Of those 836 patients, 495 (59.2%) were operated within 150 minutes. During the 30-postoperative day period, the overall morbidity was significantly lower in the short OT group (29.1% vs. 40.5%; p = 0.001). Both the duration of drainage (3 vs. 4 days; p < 0.00001) and the length of hospital stay (6 vs. 7 days; p < 0.00001) were significantly reduced in the short OT group. Two predictors of long OT were identified on multivariate analysis: male sex (OR 1.41, p = 0.04) and neoadjuvant chemotherapy (OR 3.46, p = 0.003). A long OT was identified as an individual predictor of postoperative complications (OR 1.84, p < 0.0001).

Conclusion

A prolonged OT is an individual risk factor for postoperative complications in patients undergoing VATS anatomical pulmonary resection.

[A Sweet Drink with Consequences]

A Sweet Drink with Consequences Abstract. Intoxications with ethylene glycol are rare, however, small quantities from the substance can be life-threatening. Regarding the treatment it is important to recognize the intoxication quickly and to immediately start the appropriate treatment. Intoxications with ethylene glycol or with methanol should always be considered as differential diagnosis in patients with severe metabolic acidosis. It is also very important to calculate the osmolal gap.

Painful Tooth Stimulation Elevates Matrix Metalloproteinase-8 Levels Locally in Human Gingival Crevicular Fluid

Recent studies have demonstrated that pulpal pain can induce neurogenic inflammatory reactions in gingiva and the expression of pro-inflammatory neuropeptides in gingival crevicular fluid (GCF). Neuropeptides co-ordinate the activity of immuno-effector cells and may influence the secretion of matrix metalloproteinase (MMP)-8, the major tissue-destructive protease in GCF. With this background, we studied whether experimental pulpal pain can trigger changes in GCF MMP-8 levels. The molecular forms of MMP-8 in the GCF of stimulated and non-stimulated teeth were analyzed by Western immunoblot, and MMP-8 levels by quantitative immunofluorometric assay. Painful stimulation of the upper incisor provoked significant elevations in GCF MMP-8 levels of the stimulated tooth. Western immunoblot revealed elevations in both neutrophil- and mesenchymal-type MMP-8 isoforms. At the same time, the GCF MMP-8 levels of the non-stimulated teeth were not changed. Analysis of these data indicated that pulpal pain can induce local elevations in MMP-8 levels in GCF.

Comparison of Plasma and Urine Biomarker Performance in Acute Kidney Injury

Background

New renal biomarkers measured in urine promise to increase specificity for risk stratification and early diagnosis of acute kidney injury (AKI) but concomitantly may be altered by urine concentration effects and chronic renal insufficiency. This study therefore directly compared the performance of AKI biomarkers in urine and plasma.

Methods

This single-center, prospective cohort study included 110 unselected adults undergoing cardiac surgery with cardiopulmonary bypass between 2009 and 2010. Plasma and/or urine concentrations of creatinine, cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), liver fatty acid-binding protein (L-FABP), kidney injury molecule 1 (KIM1), and albumin as well as 15 additional biomarkers in plasma and urine were measured during the perioperative period. The primary outcome was AKI defined by AKIN serum creatinine criteria within 72 hours after surgery.

Results

Biomarkers in plasma showed markedly better discriminative performance for preoperative risk stratification and early postoperative (within 24h after surgery) detection of AKI than urine biomarkers. Discriminative power of urine biomarkers improved when concentrations were normalized to urinary creatinine, but urine biomarkers had still lower AUC values than plasma biomarkers. Best diagnostic performance 4h after surgery had plasma NGAL (AUC 0.83), cystatin C (0.76), MIG (0.74), and L-FAPB (0.73). Combinations of multiple biomarkers did not improve their diagnostic power. Preoperative clinical scoring systems (EuroSCORE and Cleveland Clinic Foundation Score) predicted the risk for AKI (AUC 0.76 and 0.71) and were not inferior to biomarkers. Preexisting chronic kidney disease limited the diagnostic performance of both plasma and urine biomarkers.

Conclusions

In our cohort plasma biomarkers had higher discriminative power for risk stratification and early diagnosis of AKI than urine biomarkers. For preoperative risk stratification of AKI clinical models showed similar discriminative performance to biomarkers. The discriminative performance of both plasma and urine biomarkers was reduced by preexisting chronic kidney disease.

Tracking wind-dispersed seeds using (15)N-isotope enrichment

Seed dispersal influences a wide range of ecological processes. However, measuring dispersal patterns, particularly long-distance dispersal, has been a difficult task. Marking bird-dispersed seeds with stable (15)N isotopes has been shown to be a user-friendly method to trace seed dispersal. In this study, we determined whether (15)N urea solution could be used to enrich seeds of two common wind-dispersed plants, Eupatorium glaucescens (Asteraceae) and Sericocarpus tortifolius (Asteraceae). We further tested if the water type (distilled versus tap) in (15)N urea solutions influences the level and variability of enrichment of plant seeds, and if increasing spraying frequency per se increases enrichment. Because droughts may lower seed set or kill plants, we wanted to investigate if the additional use of an externally applied anti-transpirant affects the intake of externally applied (15)N into seeds. The results demonstrate that (15)N enrichment of seeds can facilitate dispersal experiments with wind-dispersed plants. The use of distilled water in (15)N urea solutions did not increase (15)N enrichment compared to tap water. Further, enrichment was more efficient at lower spray frequencies. Both the use of tap water and low frequencies could lower time, effort and project costs. The results suggest that species can be protected from drought using an anti-transpirant without decreasing the incorporation of (15)N into seeds.

Does single-source create an added value? Evaluating the impact of introducing x4T into the clinical routine on workflow modifications, data quality and cost-benefit

OBJECTIVES

The first objective of this study is to evaluate the impact of integrating a single-source system into the routine patient care documentation workflow with respect to process modifications, data quality and execution times in patient care as well as research documentation. The second one is to evaluate whether it is cost-efficient using a single-source system in terms of achieved savings in documentation expenditures.

METHODS

We analyzed the documentation workflow of routine patient care and research documentation in the medical field of pruritus to identify redundant and error-prone process steps. Based on this, we established a novel documentation workflow including the x4T (exchange for Trials) system to connect hospital information systems with electronic data capture systems for the exchange of study data. To evaluate the workflow modifications, we performed a before/after analysis as well as a time-motion study. Data quality was assessed by measuring completeness, correctness and concordance of previously and newly collected data. A cost-benefit analysis was conducted to estimate the savings using x4T per collected data element and the additional costs for introducing x4T.

RESULTS

The documentation workflow of patient care as well as clinical research was modified due to the introduction of the x4T system. After x4T implementation and workflow modifications, half of the redundant and error-prone process steps were eliminated. The generic x4T system allows direct transfer of routinely collected health care data into the x4T research database and avoids manual transcription steps. Since x4T has been introduced in March 2012, the number of included patients has increased by about 1000 per year. The average entire documentation time per patient visit has been significantly decreased by 70.1% (from 1116±185 to 334±83 s). After the introduction of the x4T system and associated workflow changes, the completeness of mandatory data elements raised from 82.2% to 100%. In case of the pruritus research study, the additional costs for introducing the x4T system are €434.01 and the savings are 0.48ct per collected data element. So, with the assumption of a 5-year runtime and 82 collected data elements per patient, the amount of documented patients has to be higher than 1102 to create a benefit.

CONCLUSION

Introduction of the x4T system into the clinical and research documentation workflow can optimize the data collection workflow in both areas. Redundant and cumbersome process steps can be eliminated in the research documentation, with the result of reduced documentation times as well as increased data quality. The usage of the x4T system is especially worthwhile in a study with a large amount of collected data or a high number of included patients.

Low-flow CO₂ removal integrated into a renal-replacement circuit can reduce acidosis and decrease vasopressor requirements

INTRODUCTION

Lung-protective ventilation in patients with ARDS and multiorgan failure, including renal failure, is often paralleled with a combined respiratory and metabolic acidosis. We assessed the effectiveness of a hollow-fiber gas exchanger integrated into a conventional renal-replacement circuit on CO₂ removal, acidosis, and hemodynamics.

METHODS

In ten ventilated critically ill patients with ARDS and AKI undergoing renal- and respiratory-replacement therapy, effects of low-flow CO₂ removal on respiratory acidosis compensation were tested by using a hollow-fiber gas exchanger added to the renal-replacement circuit. This was an observational study on safety, CO₂-removal capacity, effects on pH, ventilator settings, and hemodynamics.

RESULTS

CO₂ elimination in the low-flow circuit was safe and was well tolerated by all patients. After 4 hours of treatment, a mean reduction of 17.3 mm Hg (-28.1%) pCO₂ was observed, in line with an increase in pH. In hemodynamically instable patients, low-flow CO₂ elimination was paralleled by hemodynamic improvement, with an average reduction of vasopressors of 65% in five of six catecholamine-dependent patients during the first 24 hours.

CONCLUSIONS

Because no further catheters are needed, besides those for renal replacement, the implementation of a hollow-fiber gas exchanger in a renal circuit could be an attractive therapeutic tool with only a little additional trauma for patients with mild to moderate ARDS undergoing invasive ventilation with concomitant respiratory acidosis, as long as no severe oxygenation defects indicate ECMO therapy.

Zoledronate and pamidronate depress neutrophil functions and survival in mice

BACKGROUND AND PURPOSE

Bisphosphonate-related osteonecrosis of the jaw (BRONJ) has been identified as a severe complication of patients previously treated with i.v. bisphosphonates. It has been noted that necrotic bone from BRONJ sites display signs of bacterial infection suggesting that an immune defect may play a role in the pathophysiology of BRONJ. Here, we have examined the effect of two potent bisphosphonates, zoledronate and pamidronate, on neutrophil function, differentiation and survival.

EXPERIMENTAL APPROACH

The effect of bisphosphonates on chemotaxis, NADPH oxidase activity and neutrophil survival were assessed in vitro using bone marrow-derived primary neutrophils or in vitro differentiated haematopoetic progenitors from mice. The same parameters and the number of circulating neutrophils were quantified in neutrophils isolated from mice treated in vivo with zoledronate. In vivo recruitment of neutrophils was assessed by sodium periodate-induced peritonitis.

KEY RESULTS

Zoledronate and pamidronate inhibited in vitro neutrophil chemotaxis and NADPH oxidase activity in a dose-dependent manner. In vivo recruitment of neutrophils was also suppressed. Zoledronate did not affect in vitro differentiation of neutrophils but shortened their life span in a granulocyte-colony stimulating factor-dependent manner. fMLP-induced activation of RhoA activity was decreased by zoledronate treatment.

CONCLUSIONS AND IMPLICATIONS

Our results show that bisphosphonate exposure leads to impaired neutrophil chemotaxis, neutrophil NADPH oxidase activity and reduced circulating neutrophil counts. This work suggests that bisphosphonates have the potential to depress the innate immune system for a prolonged time, possibly contributing to the pathogenesis of BRONJ.

Catheter related blood stream infections in critically ill patients with continuous haemo(dia)filtration and temporary non-tunnelled vascular access

This prospective, single centre, observational study analysed the rate of catheter related blood stream infections in critically ill patients in intensive care units treated with haemo(dia)filtration. The infection rate was 3.8 per 1000 patient days. All infections were caused by coagulase negative staphylococci.

BACKGROUND

Temporary central venous catheters in patients undergoing continuous veno-venous haemo(dia)filtration contribute to serious infectious complications. The goal of this study was to assess the incidence of catheter related blood stream infections in critically ill patients treated with continuous veno-venous haemo(dia)filtration.

METHODS

Prospective observational study of all intensive care unit patients treated with continuous veno-venous haemo(dia)filtration by a central venous catheter at the University Hospital Basel. All patients underwent a standardised anti-infective protocol including screening for nasal colonisation with S. aureus on the day of catheter insertion, antiseptic catheter placement technique and daily disinfection of the insertion site followed by local mupirocin application. Catheter related blood stream infection was diagnosed according to standard guidelines of the Center of Disease Control and Prevention. Primary end point was the incidence of catheter related blood stream infection in all intensive care unit patients treated with continuous veno-venous haemo(dia)filtration.

RESULTS

From 2003 to 2007 a total of 194 consecutive critically ill patients treated with continuous veno-venous haemo(dia)filtration were investigated. 173 patients (63% men) were suitable for final analysis. Median age was 68.6 years (18.9-87.8). Eight patients (4.6%) had positive blood cultures, six of them had a catheter related blood stream infection (incidence 3.8/1000 catheter days). All infections were caused by coagulase negative staphylococci. The duration of catheter use (p = 0.02) and pre-existing chronic skin disease (p = 0.042) were identified as potential risk factors for catheter related blood stream infection.

CONCLUSIONS

The incidence of catheter related blood stream infection in critically ill patients on intensive care units treated with continuous veno-venous haemo(dia)filtration was 3.8 per 1000 catheter days. All catheter related blood stream infections were caused by coagulase negative staphylococci.

The single source architecture x4T to connect medical documentation and clinical research

Clinical trials often require large and redundant documentation efforts, because information systems in patient care and research are separated. In two clinical trials we have assessed the number of study items available in the clinical information system for re-use in clinical research. We have analysed common standards such as HL7, IHE RFD and CDISC ODM, regulatory constraints and the documentation process. Based on this analysis we have designed and implemented an architecture for an integrated clinical trial documentation workflow. Key aspects are the re-use of existing medical routine data and the integration into current documentation workflows.

[Calciphylaxis. A less well-known, clinically relevant disease]

Calciphylaxis is a rare disease which has been increasingly reported in recent decades and has consequently shifted into the focus of clinical and scientific research. The clinical picture is characterized by extensive ischemic ulcerations of the skin and subcutis. Histologically, the small vessels in these lesions show prominent calcifications. Due to the extensive areas of ulceration and necrosis as well as frequently present comorbidities, patients with calciphylaxis are prone to infection and sepsis. In this work, we describe the case of a female kidney-transplant patient with vasculitis who, despite good graft function, developed a fulminant calciphylaxis of both thighs 4 years post transplantation and died of septic complications. The differential diagnoses as well as clinical procedures are described in detail in the case history. In the discussion, we give an overview of the current state of knowledge regarding the etiopathogenesis, risk factors, diagnostic measures and clinical management of calciphylaxis.

Postural and dynamic masseter and anterior temporalis muscle EMG repeatability in serial assessments

Electromyographic (EMG) assessment has been used as a non-invasive tool to objectively assess muscle function, although with controversial research and clinical potential. The aim of this study was to assess within-, inter-subject and between-day repeatability of serial EMG recordings. The study sample included 10 asymptomatic subjects with no history of temporomandibular disorders or muscle parafunctions. Bilateral masseter and anterior temporalis muscle EMG parameters were assessed in two standardized serial recordings (day 1 to day 2) using a portable EMG equipment (ME 6000 recorder, Mega Electronics, Kuopio, Finland). The functional tasks included postural/resting activities as pre- and post-recording series of 30 s each and jaw opening/closing, intercuspal and maximal voluntary clenching activities of 5 s, repeated three times. The assessed EMG parameters included the mean amplitude, s.d. and error. In addition, the power spectrum EMG parameter assessment included the median power frequencies and the averaged EMG spectrum data values. The results of the intraclass correlation coefficient analysis indicated reliability for nearly all of the intercuspal and all clenching EMG amplitude and power spectrum parameters. This was complemented by the repeated measures anova and post hoc analyses that indicated non-significant differences between day 1 and 2 in task- and muscle-related analyses. Most variability was noted in postural and some in opening/closing tasks. In conclusion this study assessed the reliability, repeatability and limitations of postural and various dynamic masseter and temporalis EMG recordings for serial assessment.

Severe course of rat bite-associated Weil's disease in a patient diagnosed with a new Leptospira-specific real-time quantitative LUX-PCR

Leptospirosis is a zoonotic disease with global distribution, caused by spirochaetes of the genus Leptospira. Transmission of Leptospira interrogans serovar Icterohaemorrhagiae, the causative agent of Weil's disease, to humans usually results from exposure to the urine of infected, but mostly asymptomatic, rodents, either by direct contact or indirectly through contaminated soil or water. Although regarded as a re-emerging infectious disease, human leptospirosis is probably underdiagnosed due to its often unspecific clinical appearance and difficulties in culturing leptospires. Therefore, more rapid and specific diagnostic procedures are needed. Here we describe a novel real-time quantitative PCR system developed for the accurate and fast diagnosis of pathogenic Leptospira spp. Its usefulness in the management of a patient with rat bite-associated multiorgan failure is demonstrated.

BOLD fMRI deactivation of limbic and temporal brain structures and mood enhancing effect by transcutaneous vagus nerve stimulation

Direct vagus nerve stimulation (VNS) has proved to be an effective treatment for seizure disorder and major depression. However, since this invasive technique implies surgery, with its side-effects and relatively high financial costs, a non-invasive method to stimulate vagal afferences would be a great step forward. We studied effects of non-invasive electrical stimulation of the nerves in the left outer auditory canal in healthy subjects (n = 22), aiming to activate vagal afferences transcutaneously (t-VNS). Short-term changes in brain activation and subjective well-being induced by t-VNS were investigated by functional magnetic resonance imaging (fMRI) and psychometric assessment using the Adjective Mood Scale (AMS), a self-rating scale for current subjective feeling. Stimulation of the ear lobe served as a sham control. fMRI showed that robust t-VNS induced BOLD-signal decreases in limbic brain areas, including the amygdala, hippocampus, parahippocampal gyrus and the middle and superior temporal gyrus. Increased activation was seen in the insula, precentral gyrus and the thalamus. Psychometric assessment revealed significant improvement of well-being after t-VNS. Ear lobe stimulation as a sham control intervention did not show similar effects in either fMRI or psychometric assessment. No significant effects on heart rate, blood pressure or peripheral microcirculation could be detected during the stimulation procedure.

CONCLUSIONS

Our study shows the feasibility and beneficial effects of transcutaneous nerve stimulation in the left auditory canal of healthy subjects. Brain activation patterns clearly share features with changes observed during invasive vagus nerve stimulation.

Whole blood mercury and selenium concentrations in a selected Austrian population: does gender matter?

BACKGROUND

Data on mercury exposure of the Austrian population were inadequate. This study was performed to determine the causal factors underlying mercury exposure and selenium concentrations, and to estimate the gender-related health impacts.

METHODOLOGY

Venous blood samples of 78 women and 81 men were drawn at the Austrian Red Cross, Vienna. Mercury contents in acid-digested whole blood samples were measured after amalgam enrichment by CV-AAS, and selenium by AAS (heated quartz-cell) after hydrid formation.

RESULTS

The average total mercury blood content of Austrians was low (2.38+/-1.55 microgL(-1); N=152). Mercury and selenium concentrations were not different between the genders (P>0.05) but we observed discrepancies regarding the causal factors. Mercury levels in men were influenced not only by fish consumption but also by age, education level, and amalgam fillings, whereas in women, only the diet (fish/seafood, red wine consumption) determined blood mercury (P<0.05). Moreover, only the males indicated a depressive effect of dental amalgam on hematocrit (P<0.05). Regarding selenium, age and alcohol consumption led to lower concentrations in men, whereas a high-level education had the opposite effect; no determinant was found for women. For the whole study group, a significant effect of chronic disease on selenium levels could be detected (P<0.05). 18% of women and 13% of men showed marginal selenium deficiency (blood selenium<65 microgL(-1)). Selenium and mercury concentrations were not correlated.

CONCLUSIONS

Our results indicate the need to evaluate and integrate gender-related findings in metal toxicology and trace element research, because different causal factors require different preventive measures to reduce mercury exposure and the risk of low selenium concentrations. Future research is needed on the gender- and age-related differences in fish/seafood consumption habits, the modifications of mercury toxicokinetics through sex hormones, the selenium supply in Austria, and the clinical relevance of a low selenium status.

Analysis of glomerular VEGF mRNA and protein expression in murine mesangioproliferative glomerulonephritis

Capillary repair is crucial in the healing of glomerulonephritis (GN). The vascular endothelial growth factor (VEGF) has pro-angiogenic properties and plays an important role in glomerular capillary regeneration. Habu Snake Venom (HSV) GN, a murine model for mesangioproliferative GN, was induced in uninephrectomized C57/BL6 mice. Glomerular damage and capillary repair were assessed using morphometry, stereology, and confocal laser scanning microscopy. Mesangiolytic glomeruli were microdissected (days 1,3,7,14) using laser capture microdissection technique. VEGF mRNA expression was analyzed by real-time polymerase chain reaction and compared to intact glomeruli of healthy controls. Spatiotemporal VEGF gene and protein expression was determined using nonradioactive in situ hybridization and immunohistochemistry. On day 1, diseased animals developed focal mesangiolysis paralleled by a significant decrease in length density of glomerular capillaries that gradually returned to baseline levels thereafter, indicating capillary growth in response to initial injury. Glomerular VEGF mRNA expression increased on day 3 and returned back to baseline and beyond at day 14 when the glomerular recovery process was completed. Similarly, glomerular VEGF protein expression tended to be higher on day 3. The present study documents temporarily increased glomerular VEGF gene and protein expression during the healing of HSV GN, suggesting a potential role of VEGF in the repair of mesangiolytic glomerular damage.

Cerebral representation of the anorectum using functional magnetic resonance imaging

BACKGROUND

Anorectal continence depends not only on the organs of continence but also on cerebral control. There are relatively few data regarding cerebral processing of anorectal continence.

METHODS

Thirteen healthy subjects underwent rectal distension to cause urge increasing to discomfort during functional magnetic resonance imaging (fMRI). In addition, a painful heat stimulus was applied to the skin of the anterior abdominal wall in the dermatome corresponding to the rectum. Voluntary contraction of the anal sphincter was also performed. Subjective rating of stimulus intensity was recorded. Evaluation of the data used a general linear model with Brain Voyager(trade mark).

RESULTS

Subjective sensation of discomfort increased during repeated rectal distension and caused activation in the anterior cingulate gyrus, insula, thalamus and secondary somatosensory cortex seen on fMRI. Perception of rectal urge and discomfort activated the same cerebral regions with differing intensity. Application of a painful thermal stimulus in the corresponding dermatome showed a modification of the response. Voluntary contraction of the anal sphincter led to activation of the motor cortex and increased activity in the supplementary motor cortex and the insula.

CONCLUSION

Cerebral representation of the anorectum as mapped by fMRI is intricate and reflects the complexity of the continence mechanism.

Capsaicin-induced local elevations in collagenase-2 (matrix metalloproteinase-8) levels in human gingival crevice fluid

BACKGROUND AND OBJECTIVES

Application of capsaicin on alveolar mucosa provokes pain and neurogenic vasodilatation in the adjacent gingiva. Pain-associated inflammatory reactions may initiate expression of several pro-inflammatory mediators. Collagenase-2 (matrix metalloproteinase-8: MMP-8) is the major destructive protease, especially in the periodontitis-affected gingival crevice fluid (GCF). With this background, we wished to study whether capsaicin stimulation of alveolar mucosa can induce changes in the GCF MMP-8 levels.

MATERIAL AND METHODS

For 10 generally and periodontally healthy human volunteers, capsaicin (3%)-moistened filter paper was applied unilaterally to the buccal alveolar mucosa on the anterior maxilla. GCF samples were collected from the tooth at the stimulation site and from several other incisors in the upper jaw. MMP-8 levels and molecular forms in GCF samples were determined by immunofluorometric assay (IFMA) and western immunoblotting, respectively.

RESULTS

Capsaicin stimulation of the alveolar mucosa induced significant local elevations in levels and activation of MMP-8 in GCF of the adjacent teeth. Western immunoblot revealed that both neutrophil- and mesenchymal-type MMP-8 isoforms were elevated and activated, together with 110 kDa high-molecular size MMP-8 species. This capsaicin-evoked MMP-8 elevation lasted several minutes after stimulation. During the experiments, no marked changes occurred in MMP-8 levels in the GCF of distantly located teeth.

CONCLUSIONS

These results suggest that capsaicin-evoked neurogenic gingival inflammation can trigger the expression and activation of MMP-8 in GCF of the adjacent teeth.

Cortical representation of experimental tooth pain in humans

Cortical processing of electrically induced pain from the tooth pulp was studied in healthy volunteers with fMRI. In a first experiment, cortical representation of tooth pain was compared with that of painful mechanical stimulation to the hand. The contralateral S1 cortex was activated during painful mechanical stimulation of the hand, whereas tooth pain lead to bilateral activation of S1. The S2 and insular region were bilaterally activated by both stimuli. In S2, the center of gravity of the activation during painful mechanical stimulation was more medial/posterior compared to tooth pain. In the insular region, tooth pain induced a stronger activation of the anterior and medial parts. The posterior part of the anterior cingulate gyrus was more strongly activated by painful stimulation of the hand. Differential activations were also found in motor and frontal areas including the orbital frontal cortex where tooth pain lead to greater activations. In a second experiment, we compared the effect of weak with strong tooth pain. A significantly greater activation by more painful tooth stimuli was found in most of those areas in which tooth pain had induced more activation than hand pain. In the medial frontal and right superior frontal gyri, we found an inverse relationship between pain intensity and BOLD contrast. We concluded that tooth pain activates a cortical network which is in several respects different from that activated by painful mechanical stimulation of the hand, not only in the somatotopically organized somatosensory areas but also in parts of the 'medial' pain projection system.

Tau suppression in a neurodegenerative mouse model improves memory function

Neurofibrillary tangles (NFTs) are the most common intraneuronal inclusion in the brains of patients with neurodegenerative diseases and have been implicated in mediating neuronal death and cognitive deficits. Here, we found that mice expressing a repressible human tau variant developed progressive age-related NFTs, neuronal loss, and behavioral impairments. After the suppression of transgenic tau, memory function recovered, and neuron numbers stabilized, but to our surprise, NFTs continued to accumulate. Thus, NFTs are not sufficient to cause cognitive decline or neuronal death in this model of tauopathy.

BOLD effects in different areas of the cerebral cortex during painful mechanical stimulation

The contribution of four cortical areas (S1, S2, insular cortex and gyrus cinguli) to pain processing was assessed by functional magnetic resonance imaging (fMRI). Phasic (mechanical impact) and tonic stimuli (squeezing) were applied to the back of a finger, both at two different strengths. Stimuli were adjusted to inflict weak and strong pain sensations. It had been shown before that stronger noxious mechanical stimuli induce a weaker input from myelinated mechanoreceptors, but a more vigorous input from nociceptive primary afferents, and vice versa. Sizes of activation clusters and percent increase of the blood oxygenation level dependent (BOLD) signal during activation were compared in the areas of interest. Phasic stimulus patterns were more closely reflected in the time course of the MR signal in S1, S2 and the cingulate than tonic patterns, since the tonic stimuli tended to induce slow MR signal increase also during the resting periods which is in parallel to the persisting character of the tonic pain sensations. In S1 only the contralateral side was activated in most cases, and the more painful stimuli did not induce greater BOLD responses compared to the less painful stimuli in this area. Paradoxically, more painful stimuli produced smaller activation clusters in S1, both in tonic and phasic stimulus trials. In contralateral S2 more painful phasic stimuli induced significantly stronger BOLD responses than the weaker stimuli. The responses to tonic stimuli did not differentiate painfulness and were significantly smaller than the phasic. Activation clusters in this area were also smaller for tonic stimuli. In the gyrus cinguli more painful phasic stimuli induced stronger BOLD responses, but no difference was seen between tonic stimulation of different strength. Though the insular cortex was often bilaterally activated, no significant differences between stimulus quality or intensity were found. Our results provide evidence for a contribution of the S2 projection area and of the cingulate cortex to the processing of the intensity dimension of phasic mechanical pain. Such evidence was not found for the S1 area, which probably receives dominant input from non-nociceptive mechanoreceptors.

Factors associated with coronary artery calcification in young female patients with SLE

BACKGROUND

With improved survival rates of patients with systemic lupus erythematosus (SLE), damage such as accelerated atherosclerosis gains increasing importance.

OBJECTIVE

To identify the prevalence of coronary artery calcifications (CAC) in asymptomatic patients.

METHODS

Electron beam tomography (EBT) was performed in 75 female patients with SLE aged <50. The results were correlated with traditional and SLE related factors associated with CAC. 49 women with symptomatic coronary heart disease (CHD) and 279 women without CHD were also analysed.

RESULTS

Overall, 21/75 (28%) patients had CAC. Low HDL cholesterol levels <1.40 mmol/l (p=0.03, OR=1.8, 67% v 39%) and cigarette smoking (p=0.01, OR=5.7, 76% v 44%) were identified as factors associated with CAC. Hypertension and high cholesterol were more common in women with CHD (p<0.01) than in those without CHD. SLE related factors were proteinuria (1331 v 465 mg/day, p=0.02), impaired renal function (p=0.02, OR=2.6, 26% v 6%), and high C3 levels (p=0.04, OR=1.8, 65% v 38%). High C3 levels were also more common in symptomatic CHD (p=0.02). The prevalence of Sm antibodies was lower in patients with CAC (15% v 42%, p=0.03). In a multivariate analysis, cigarette smoking, reduced renal function, high C3, and a cumulative steroid dose above 30 g were the most important CAC associated factors in the lupus cohort.

CONCLUSION

A subgroup of patients with SLE with CAC without any clinical symptoms of CHD was identified by EBT. Therefore, EBT is useful for assessing asymptomatic atherosclerosis in this group.

Laser capture microdissection and real-time PCR for analysis of glomerular endothelin-1 gene expression in mesangiolysis of rat anti-Thy 1.1 and murine Habu Snake Venom glomerulonephritis

Molecular analysis of pathologic changes in glomeruli requires methods allowing rapid and exact detection of alterations in gene expression. Here, we analyzed endothelin-1 (ET-1) mRNA expression in mesangiolytic glomeruli during the course of a rat and murine model of mesangioproliferative glomerulonephritis (GN). A novel method combining laser capture microdissection (LCM), which permits the precise removal of selected mesangiolytic glomeruli, with a highly sensitive real-time RT-PCR technique was used. Anti-Thy 1.1. GN was introduced in male Sprague-Dawley rats (1.0 mg/kg body weight of OX-7 IV) and Habu Snake Venom GN was introduced in C57BL6 mice (habu snake venom toxin 6 mg/kg body weight IV). The degree of mesangiolysis during both GNs was analyzed using a semiquantitative scoring system. Mesangiolytic glomeruli were microdissected at different days of the diseases (day 2, 6, and 12 in anti-Thy 1.1 GN and days 1, 3, 7, and 14 in Habu Snake Venom GN) and from normal control animals. After RNA extraction and cDNA synthesis, ET-1 gene expression was measured by real-time RT-PCR. In parallel, in anti-Thy 1.1. GN ET-1 mRNA expression was analyzed using semiquantitative nonradioactive in situ hybridization; ET-1 protein expression was investigated by immunohistochemistry. Mesangiolysis peaked at day 6 in anti-Thy1.1 GN and at day 1 in Habu Snake Venom GN. Mesangiolytic glomeruli were easily microdissected on cryostat sections in both models; quantification of mRNA with RT-PCR was reliable and reproducible. Glomerular ET-1 mRNA expression increased during the course of anti-Thy 1.1 GN and Habu Snake Venom GN peaked when mesangiolysis was most pronounced. This was seen by RT-PCR after glomerular LCM and by in situ hybridization; in parallel, glomerular ET-1 protein expression was increased. Combination of LCM and RT-PCR is a reliable method for quantification of localized gene expression in isolated renal structures. The above data argue for an important role of ET-1 in pathogenesis and/or repair of mesangiolysis in experimental mesangioproliferative GN.

Low-threshold heat receptor in chick sensory neurons is upregulated independently of nerve growth factor after nerve injury

In mammals, the cloned low-threshold heat receptor, vanilloid receptor subtype 1 (VR1), is involved in the genesis of thermal hyperalgesia after inflammation. However, there is evidence that VR1 is not involved in the thermal hyperalgesia that occurs after nerve injury. In search for other heat receptors which might be involved in this phenomenon, we previously demonstrated that chick dorsal root ganglion neurons, which are insensitive to capsaicin, respond to low-threshold heat. Here, we investigated whether expression of the low-threshold noxious heat receptor in chicks is regulated by nerve growth factor (NGF), as VR1 is in mammals. Heat (44 degrees C) responsiveness of isolated dorsal root ganglion neurons of chicks was investigated (i) under culture conditions for up to 4 days with and without NGF and (ii) after a tight ligation of the sciatic nerve for up to 6 days, using cobalt-uptake method. In every case, a significant upregulation in the proportion of heat-responsive neurons was observed. On the molecular level, there was an increase of chick VR1 mRNA level in dorsal root ganglion cells cultured for 3 days in medium lacking NGF. In rat dorsal root ganglion neurons cultured for 1-4 days without NGF, patch-clamp experiments revealed that after 1 day almost all neurons responding to heat also responded to capsaicin, whereas after 3-4 days, more than one-half of the heat-responsive neurons did not respond to capsaicin. These data suggest the existence of low-threshold heat receptors in chick dorsal root ganglion neurons, the expression of which is regulated independently of NGF.

Differences between tooth stimulation and capsaicin-induced neurogenic vasodilatation in human gingiva

Animal experiments have shown that the application of capsaicin to oral mucosa leads to a neurogenic inflammation associated with blood flow elevations in gingivomucosal tissues. In this investigation, we measured the tooth stimulation and capsaicin-evoked blood flow responses in maxillary gingiva in humans to study whether axon-reflex-mediated vasodilatation crosses the midline of the maxilla. The vasoactive reactions were mapped by laser Doppler imaging. Unilateral stimulation of alveolar mucosa and attached gingiva by capsaicin evoked a distinct neurogenic vasodilatation in ipsilateral gingiva, which rapidly attenuated at the midline. Capsaicin stimulation of alveolar mucosa provoked clear inflammatory reactions. In contrast to capsaicin stimuli, tooth stimulation produced symmetrical vasodilatations bilaterally in the gingiva. The ipsilateral responses were significantly smaller during tooth stimulation than during capsaicin stimuli. Analysis of these data suggests that capsaicin-induced inflammatory reactions in gingivomucosal tissues do not cross the midline in the anterior maxilla. The enhanced reaction found during stimulation of alveolar mucosa indicates that alveolar mucosa is more sensitive to chemical irritants than attached gingiva.

Blood flow increase in the human lip after high-intensity tooth stimulation is not based on cholinergic mechanisms

The purpose of this study was to investigate whether parasympathetic cholinergic pathways are involved in the regulation of orofacial blood flow. The effect of atropin (1 mg, iv.) on blood flow responses in the lower lip, nose and hand during painful tooth stimulation was studied in healthy human subjects (n=8). In all subjects, tooth stimulation caused a long lasting vasodilatation in the lower lip. During stimulation there was a transient elevation in heart rate (HR) and blood pressure (BP) concomitantly with a blood flow decrease in the finger and nose. With atropin, the pain-induced HR and BP elevations and blood flow reductions in the nose and finger were decreased. However, the pain-induced blood flow increase in the lip was not changed. This study indicates that the tooth stimulation-induced vasodilatation in the lip is not based on parasympathetic cholinergic mechanisms.

Cyclooxygenase-2 inhibitor ns-398 protects neuronal cultures from lipopolysaccharide-induced neurotoxicity

BACKGROUND AND PURPOSE

The prostanoid-synthesizing enzyme cyclooxygenase (COX)-2 is markedly upregulated after cerebral ischemia and may participate in the mechanisms by which postischemic inflammation contributes to the late stages of ischemic brain injury. In the present study, we sought to provide additional evidence for a role of COX-2 in the mechanisms of neurotoxicity associated with inflammation.

METHODS

Nine-day-old neuronal-glial cultures, prepared from the cerebral cortex of newborn C57BL/6J mice, were exposed to lipopolysaccharide (LPS), a potent proinflammatory agent. The contribution of COX-2 was investigated by using the COX-2 inhibitor NS-398.

RESULTS

LPS produced a dose-dependent (0.001 to 10 microg/mL) and selective neuronal death that was well developed 72 hours after treatment. The effect was associated with a marked increase in the concentration of the COX reaction product prostaglandin E(2) (PGE(2)) and of the cytokine tumor necrosis factor-alpha (TNF-alpha). NS-398 (10 micromol/L) blocked the PGE(2) increase, attenuated the TNF-alpha increase, and prevented the neuronal death produced by LPS. TNF-alpha-blocking antibodies attenuated LPS-induced neuronal death, but the protection was less pronounced than that afforded by NS-398. LPS failed to elevate PGE(2) or to produce cell death in neuron-enriched cultures, suggesting that glial cells are required for these effects.

CONCLUSIONS

COX-2, in part through TNF-alpha-related mechanisms, contributes to LPS-induced neuronal death. The data support the hypothesis that COX-2, in addition to its role in glutamate excitotoxicity, participates in the cytotoxicity associated with inflammation.

Structural alterations of adhesion mediating components in cells cultured on poly-beta-hydroxy butyric acid

Polymers may serve as a biodegradable material in tissue engineering. To assess the biocompatibility of poly-beta-hydroxy butyric acid (PHB), we studied the structural organization of cellular molecules involved in adhesion using osteoblastic and epithelial cell lines. On PHB, both cell lines revealed a rounded cell shape due to reduced spreading. The filamentous organization of the actin cytoskeleton was impaired. In double immunofluorescence analyses we demostrated that the colocalization of the fibronectin fibrils with the actin filaments was lost in cultures on PHB. Similarly, collagen II distribution was altered, whereas the organization of collagen I was not obviously affected. Further evidence for impaired structural organization was obtained for the beta1-integrin receptor and vinculin which mediate the interaction of the cytoskeleton with the extracellular matrix. In confluent epithelial cells, the tight junction protein ZO-1 showed a larger lateral extension in the cell-cell contacts when cells were grown on PHB. Because structural organization of components which mediate cell-matrix and cell-cell adhesion controls cell physiology these parameters could be a sensitive indicator for the biocompatibility of implant materials.

Seizure's outcome after cortical resections including the face and tongue rolandic areas in patients with refractory epilepsy and normal MRI submitted to subdural grids' implantation

PURPOSE

To study the seizure's outcome in patients with refractory epilepsy and normal MRI submitted to resections including the rolandic cortex.

METHODS

Four adult patients were studied. All patients had motor or somatosensory simple partial seizures and normal MRI and were submitted to subdural grids' implantation with extensive coverage of the cortical convexity (1 in the non-dominant and 3 in the dominant hemisphere).

RESULTS

ECoG was able to define focal areas of seizures' onset in every patient. All patients were submitted to resection of the face and tongue motor and sensitive cortex; two patients had resections including the perirolandic cortex and 2 had additional cortical removals. Three patients are seizures' free and one had a greater then 90% reduction in seizure frequency.

CONCLUSION

Resections including the face and tongue rolandic cortex can be safely performed even within the dominant hemisphere.