Paraneoplastic Polyarthritis in a Patient with Synchronous Lung and Colorectal Malignancy

Arthritis is an unusual manifestation of paraneoplastic syndrome, appearing in a variety of cancers, including pulmonary and colorectal. It can often pose a diagnostic challenge to physicians, since it may be difficult to distinguish from more commonly encountered rheumatic illnesses. Moreover, synchronous cancers are rare and unexpected in patients with symmetrical polyarthritis. Hypertrophic pulmonary osteoarthropathy is to be considered in patients with polyarthritis and lung neoplasia. The aim of this report is to highlight the case of a patient presenting with paraneoplastic polyarthritis, which led to identifying the presence of underlying synchronous lung and colorectal malignancies. Lymph node biopsy was performed raising suspicion of Caplan's syndrome but lung lobectomy confirmed adenocarcinoma. Rheumatologists should be reacquainted with rheumatic manifestations in malignant diseases.

Nurse Preceptors' Experiences of an Online Strength-Based Nursing Course in Clinical Teaching

Background: Online educational programs for nurse preceptors have been created based on various theoretical frameworks; however, no programs using a Strengths-Based Nursing (SBN) approach could be located. Purpose: This qualitative descriptive study explored the nurse preceptors' experiences in using a SBN approach to provide clinical teaching to nursing students after completing an online SBN clinical teaching course. Methods: Semi-structured interviews were conducted with six nurses. Data was thematically analyzed. Findings: Although their levels of familiarity with SBN varied, all preceptors acknowledged that using a SBN approach in clinical teaching benefits both students and educators. They reported that it empowered students and that it allowed them to discover their strengths. Getting to know their students helped the preceptors provide tailored learning experiences and feedback. Using the SBN approach simultaneously enhanced the preceptors' self-confidence and created opportunities for shared learning. Conclusion: Using a strengths' approach offers nurse preceptors a powerful tool to facilitate student learning and skills development in clinical practice.

Temporal evolution of liver function parameters predicts clinical outcome in chronic heart failure patients (Bio-SHiFT Study)

Background

Liver dysfunction contributes to worse clinical outcome in heart failure (HF) patients, and cholestatic enzymes are associated with mortality in the setting of chronic HF (CHF). However, the temporal evolutions of liver function parameters in stable CHF patients, and their associations with clinical outcome, have not yet been investigated.

Purpose

We aimed to investigate in detail the temporal patterns of alkaline phosphatase (ALP), gamma glutamyl transpeptidase (GGTP), total bilirubin (TBIL) and albumin (ALB), and their relation with clinical outcome, in patients with stable CHF with reduced ejection fraction (HFrEF).

Methods

During 2.2 (1.4–2.5) years of follow-up, we collected 1984 tri-monthly plasma samples in 263 patients. We selected 749 samples in the 250 HFrEF patients included in the study - all baseline samples, the last two samples before censoring in event-free patients, and the last two samples preceding the primary endpoint (PEP; composite of cardiac death, heart transplantation, LVAD implantation, and hospitalization for the management of acute or worsened HF). In these samples ALP, GGTP, and ALB were measured using colorimetric assays, TBIL using diazomethod, all by Roche/Hitachi Cobas c analyser. The relationship between repeatedly measured biomarker levels and the PEP was evaluated by joint models.

Results

Mean age was 68±18 years; 74% were men, 25% in NYHA class III or IV. 66 patients (26%) reached the PEP.

Repeatedly measured levels of TBIL, ALP, GGTP and ALB were associated with the PEP in a model adjusted for NT-proBNP and hs-TnT (hazard ratio (HR) [95% confidence interval] per doubling of biomarker level: 1.98 [1.32; 2.95], p=0.002; 1.84 [1.09; 3.05], p=0.018, 1.33 [1.08; 1.63], p=0.006 and 1.14 [1.09; 1.20], p<0.001, respectively). Serially measured ALP and GGTP remained significantly associated with the PEP after adjustment for clinical covariates (HR [95% CI]: 1.13 [1.07; 1.19], p=0.018; 1.03 [1.01; 1.06], p=0.006, respectively).

The levels of ALP and GGTP were higher in patients who experienced the PEP than in event-free patients long before the PEP occurred (>2 years), and as the PEP approached, levels diverged slightly between those with and without the PEP (Figure 1). Conversely, levels of ALB were higher in those with subsequent PEP, >2 years before the PEP, and subsequently fell; while TBIL levels rose less than 1 year before the PEP in those with subsequent PEP. The slopes of the temporal evolution of ALB and TBIL, adjusted for clinical variables, were also significantly associated with the PEP (HR [95% CI] per 20% decrease in the slope for albumin and increase in the slope of TBIL per year: 1.61 [1.43; 1.84], p<0.001 and 1.72 [1.28; 2.55], p<0.001, respectively).

Conclusions

Changes in serum levels of TBIL, ALP, GGTP and ALB precede adverse cardiovascular events in patients with CHF. These routine liver function parameters may provide additional prognostic information in HFrEF patients in clinical practice.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Jaap Schouten Foundation (Rotterdam, the Netherlands)Noordwest Academie (Alkmaar, the Netherlands)

Therapeutic options in refractory anti-MDA5 dermatomyositis triggered by SARS-CoV-2 infection

Anti-MDA-5 dermatomyositis (DM) is a rare disease subtype characterized by rapidly progressive interstitial lung disease alongside skin, vascular and visceral involvement. The severity of the pulmonary disease is corelated with a weaker prognosis. A 31-year-old female patient was admitted for hand arthritis, upper girdle pain and multiple erythematous papular facial lesions on the face, digital ulcerations and Raynaud’s. The symptoms started immediately after the onset of the SARSCoV-2 infection. Positive anti-MDA5 and anti-centromere antibodies were identified, thus amyopathic DM - CREST syndrome overlap diagnosis was placed. Due to pulmonary involvement, corticosteroids, immunomodulatory drugs (mycophenolate mofetil, hydroxychloroquine, cyclophosphamide) were initiated, with no clinical benefits. Lack of response led to initiation of rituximab, oral tacrolimus and nintedanib with no apparent progression of the disease. Refractory cases require escalation of the standard therapeutic approach. SARS-CoV-2 infection can represent a trigger of autoimmunity in DM which needs to be further assessed.

AB0879-HPR MOTIVATION OF HEALTHCARE PROVIDERS DURING COVID19 PANDEMIC OUTBREAK

Background:

Since the beginning of 2020, the medical staff caring for patients with rheumatic disorders has been exposed to considerable emotional and physical stress due to the COVID19 pandemic outbreak. Newly-designed circuits were imposed to better manage chronic patient admissions.

Objectives:

To assess the level of motivation in healthcare personnel caring for patients with rheumatic disorders and identify determinants that lead to dissatisfaction during the COVID19 spread.

Methods:

A 15-item questionnaire was distributed among medical and paramedical staff looking after chronic rheumatic patients. Motivation factors were included in questions having five preset answers, ranging from “not al all”, “to a small extent”, “moderately”, “to a large extent” and “to a very large extent”. The final item was an open-type question, favoring personal suggestions and potential changes in local management.

Results:

Out of a total of a 124 responders, 82 were doctors with various degrees in training (fellow trainees, specialists in Rheumatology, Head of Department), 37 medical assistants, 3 nurses, a physical therapist, one clinical psychologist. Mean age in the group was 38.3 years old with a strikingly female dominance (87.6%). Within the responders, the financial factor represented by monthly salary or bonuses had no or little impact on work motivation during the pandemic since more than 70% answered with “not al all / to a small extent / moderately”. Regarding motivation through working hours, 26.7% responded either “not at all” or “to a small extent”, 32.4% were moderately motivated while only 12.4% were more enthusiastic. More than half (53.4%) of the staff stated that motivation was not entirely affected by working conditions in the hospital. Answers were relatively equally divided referring to motivation by safety at their workplace (almost 20% for each statement), and 40.9% suffered some extent of demotivation due to risk of contamination while caring for COVID19 positive patients. 42% of the staff was only moderately motivated by hospital’s measure to limit the spread of COVID throughout the personnel. Almost 75% of the healthcare workers were not motivated by news media. Around 54% said that personal motivation was not influenced by a larger work volume and 43% were very much motivated by work relationships with colleagues. 41% of the staff is only moderately satisfied with their work during the COVID outbreak while 18% are not at all satisfied. Finally, the last open-question confirmed that for some the pandemic period was a time to bring healthcare professionals together to a stronger bond. Other responders felt that chronic rheumatic patients were left aside, while caring mostly for COVID19 patients and only limited admissions for life-threatening conditions. Moreover, medical staff suggested that the lack of a more frequent testing throughout the personnel to avoid contamination was demotivating, while still living with families or relatives.

Conclusion:

Motivation of the personnel is a process with great economic and social impact. This study challenged the level of healthcare staff in difficult times caused by medical crisis. Results of the enquiry showed that financial benefits had no impact on motivation. Harsher working conditions or larger volume did not negatively impact motivation of staff, but the fear of contamination was considerable. Apparently the media influence was not a motivator for medical staff during the outbreak. Medical teams should find their stamina until the end of pandemia.

References:

[1]Barati, M, Bashirian, S et al, Factors associated with preventive behaviours of COVID-19 among hospital staff in Iran in 2020: an application of the Protection Motivation Theory, Journal of Hospital Infection 2020.

[2]Barati, M, Bashirian, S et al, Factors associated with preventive behaviours of COVID-19 among hospital staff in Iran in 2020: an application of the Protection Motivation Theory, Journal of Hospital Infection 2020.

Disclosure of Interests:

None declared

Electrochemical Platform Based on Modified Ti Electrodesto Test a Food Allergen pPresence

Celiac disease (CD) is an autoimmune disorder. For these patients, the only treatment is a gluten free diet. In this work we showed that there can be an easy and cheap method to test gluten presence. We used several modified Ti electrodes. All modified electrodes were prepared using electrochemical methods. Modified electrodes were tested using differential pulse voltammetry in solutions with or without gluten. Selected modified Ti electrode was tested using different known gluten concentrations and extracts from different aliments.

Hypoxic Rise in Cytosolic Calcium and Renal Proximal Tubule Injury Mediated by a Nickel-Sensitive Pathway

In the kidney, cell injury resulting from ischemia and hypoxia is thought to be due, in part, to increased cytosolic Ca2+ levels, [Ca2+]i, leading to activation of lytic enzymes, cell dysfunction, and necrosis. We report evidence of a progressive and exponential increase in [Ca2+]i (from 245 ± 10 to 975 ± 100 nM at 45 mins), cell permeabilization and propidium iodide (PI) staining of the nucleus, and partial loss of cell transport functions such as Na+-gradient–dependent uptakes of 14C-alpha-methyiglucopyranoside and inorganic phosphate (32Pi) in proximal convoluted tubules of adult rabbits subjected to hypoxia. The rise in [Ca2+]i depended on the presence of extracellular [Ca2+] and could be blocked by 50 μM Ni2+ but not by verapamil (100 μM). Presence of 50 μM Ni2+ also reduced the hypoxia-induced morphological and functional injuries. We also used HEK 293 cells, a kidney cell line, incubated in media without glucose and exposed for 3.5 hrs to 1% O2–5% CO2 and then returned to glucose-containing media for another 3.5 hrs in an air–5% CO2 atmosphere and finally exposed for 1 min to media containing 1 μM Pl. NiCl2 (50 μM) or pentobarbital (300 μM) more than phenobarbital (1.5 mM), when present in the incubation medium during both the hypoxic and the reoxygenation periods, induced significant (P < 0.001) reductions in the number of cell nuclei stained with Pl, similar to their relative potency as inhibitors of T channels. Our findings indicate that hypoxia-induced alterations in calcium level and subsequent cell injury in the proximal convoluted tubule and in HEK cells involve a nickel-sensitive and dihydropyridine insensitive pathway or channel.

The effect of levodopa-carbidopa intestinal gel infusion long-term therapy on motor complications in advanced Parkinson's disease: a multicenter Romanian experience

Chronic treatment with oral levodopa is associated with an increased frequency of motor complications in the late stages of Parkinson’s disease (PD). Continuous administration of levodopa–carbidopa intestinal gel (LCIG—Duodopa^®, Abbott Laboratories), which has been available in Romania since 2009, represents an option for treating patients with advanced PD. Our primary objective was to report changes in motor complications after initiation of LCIG therapy. The secondary objectives were as follows: to determine the impact of LCIG therapy on the daily levodopa dose variation before/and after LCIG, to collect patient self-assessments of quality of life (QoL), and to study the overall tolerability and safety of LCIG administration. A retrospective analysis (2009–2013) of LCIG therapy and the experience in nine neurology centers in Romania was performed. The impact of LCIG therapy was evaluated by analyzing changes in motor fluctuations, dyskinesia and the patients’ QoL after initiating therapy. The safety of LCIG therapy was estimated by noting agent-related adverse events (AEs) and medical device-related AEs. In the 113 patients included, we observed a significant improvement in PD symptoms after initiation of LCIG therapy. The “on” period increased, with a mean value of 6.14 h, and the dyskinesia period was reduced, with a mean value of 29.4 %. The quantified non-motor symptoms subsided. The patients exhibited significant improvements in QoL scores. There were few AEs and few cases of LCIG therapy discontinuation. LCIG is an important and available therapeutic option for managing patients with advanced PD.

Preventing LVAD implantation by early short-term mechanical support and prolonged inodilator therapy : A case series with acute refractory cardiogenic shock treated with veno-arterial extracorporeal membrane oxygenation and optimised medical strategy

Cardiogenic shock continues to be a life-threatening condition carrying a high mortality and morbidity, where the prognosis remains poor despite intensive modern treatment modalities. In recent years, mainly technical improvements have led to a more widespread use of short- and long-term mechanical circulatory support, such as veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and left ventricular assist devices (LVADs). Currently, LVADs are indispensable as 'bridge' to cardiac recovery, heart transplantation (HTX), and/or as destination therapy Importantly, both LVADs and HTX put a vast burden on financial resources, besides significant short- and long-term risks of morbidity and mortality. These considerations underscore the importance of optimal timing and appropriate patient selection for LVAD therapy, avoiding as much as possible an unfortunate and costly clinical path. In this report, we present a series of three cases with acute refractory cardiogenic shock ('crash and burn', INTERMACS profile 1) successfully treated by ECMO and early optimal medical therapy preventing a certain path towards LVAD and/or HTX, for which they were initially referred. This conservative approach in INTERMACS profile one patients warrants very early introduction of adequate medical heart failure therapy under the umbrella of a combination of short-term mechanical circulatory and inotropic support by phosphodiesterase inhibitors. Therefore, this novel combined medical-mechanical approach could have important clinical implications for this extremely challenging patient category, as it may avoid an unnecessary and costly clinical path towards LVAD and/or heart transplantation.

Commissioning of an integrated platform for time-resolved treatment delivery in scanned ion beam therapy by means of optical motion monitoring

The integrated use of optical technologies for patient monitoring is addressed in the framework of time-resolved treatment delivery for scanned ion beam therapy. A software application has been designed to provide the therapy control system (TCS) with a continuous geometrical feedback by processing the external surrogates tridimensional data, detected in real-time via optical tracking. Conventional procedures for phase-based respiratory phase detection were implemented, as well as the interface to patient specific correlation models, in order to estimate internal tumor motion from surface markers. In this paper, particular attention is dedicated to the quantification of time delays resulting from system integration and its compensation by means of polynomial interpolation in the time domain. Dedicated tests to assess the separate delay contributions due to optical signal processing, digital data transfer to the TCS and passive beam energy modulation actuation have been performed. We report the system technological commissioning activities reporting dose distribution errors in a phantom study, where the treatment of a lung lesion was simulated, with both lateral and range beam position compensation. The zero-delay systems integration with a specific active scanning delivery machine was achieved by tuning the amount of time prediction applied to lateral (14.61 ± 0.98 ms) and depth (34.1 ± 6.29 ms) beam position correction signals, featuring sub-millimeter accuracy in forward estimation. Direct optical target observation and motion phase (MPh) based tumor motion discretization strategies were tested, resulting in −0.3(2.3)% and −1.2(9.3)% median (IQR) percentual relative dose difference with respect to static irradiation, respectively. Results confirm the technical feasibility of the implemented strategy towards 4D treatment delivery, with negligible percentual dose deviations with respect to static irradiation.

Clinical improvement and cortical adaptations after functional electrical stimulation in Parkinson's disease patients

Parkinson's disease (PD) is a neurodegenerative disease of the central nervous system. Although PD is commonly characterized by well-known clinical manifestations, it also involves imbalances in the cortico-subcortical excitation and inhibition processes. Functional electrical stimulation can improve the motor condition of PD patients as a supplement to levodopa therapy. In this study, clinical (using specific tests) and paraclinical (using single-pulse transcranial magnetic stimulation) examinations revealed an improvement in the motor symptoms and the bilateral activation of the primary motor areas of the upper limbs after unilateral functional electrical stimulation in PD patients.

Living donor liver transplantation with dual grafts -- a case report

BACKGROUND

Living donor liver transplantation (LDLT) exposes to risks both the donor, due to a potential small residual liver volume, and the recipient, who faces the risk of small-for-size graft syndrome. In order to overcome these drawbacks, liver grafts from two different donors can be used. This paper presents a case of dual graft LDLT using a right hemiliver and a left lateral section from related donors.

CASE PRESENTATION

A 14-year old female diagnosed with chronic hepatic failure due to Wilson's disease with Model-for-End- Stage-Liver-Disease score of 25, underwent a dual graft LDLT, receiving a right hemiliver with a reconstructed middle hepatic vein from her sister, and a left lateral section from her mother. None of the grafts complied with a satisfactory graft-to-recipient weight ratio (GRWR), if they would have been independently transplanted. The combined GRWR was 1.10. The donors and the recipient have been followed-up for over 1 year.

RESULTS

The donors had no postoperative complications. The donors and the recipient were discharged 8 and 19 days after surgery, respectively. After 12-month follow-up, both donors and the recipient were alive, with normal graft function.

CONCLUSION

Dual graft LDLT can be a feasible solution to overcome the risk of small-for-size graft syndrome.

ABBREVIATIONS

BSA = body surface area, GRWR = graft-to-recipient weight ratio, GV SLV = recipient standard liver volume, HA = hepatic artery, HD = hepatic duct, HV = hepatic vein, LDLT = Living donor liver transplantation, LL = left lobe, LLS = left lateral section, MELD = Model for End-Stage Liver Disease, POD = postoperative day, PV = portal vein, RL = right lobe, SFS = small-for-size graft, SLV = standard liver volume, WD = Wilson's disease.

Tumor tracking based on correlation models in scanned ion beam therapy: an experimental study

Accurate dose delivery to extra-cranial lesions requires tumor motion compensation. An effective compensation can be achieved by real-time tracking of the target position, either measured in fluoroscopy or estimated through correlation models as a function of external surrogate motion. In this work, we integrated two internal/external correlation models (a state space model and an artificial neural network-based model) into a custom infra-red optical tracking system (OTS). Dedicated experiments were designed and conducted at GSI (Helmholtzzentrum für Schwerionenforschung). A robotic breathing phantom was used to reproduce regular and irregular internal target motion as well as external thorax motion. The position of a set of markers placed on the phantom thorax was measured with the OTS and used by the correlation models to infer the internal target position in real-time. Finally, the estimated target position was provided as input for the dynamic steering of a carbon ion beam. Geometric results showed that the correlation models transversal (2D) targeting error was always lower than 1.3 mm (root mean square). A significant decrease of the dosimetric error with respect to the uncompensated irradiation was achieved in four out of six experiments, demonstrating that phase shifts are the most critical irregularity for external/internal correlation models.

On the Early Stages of the Formation Reaction of Cementite, Fe3C

The formation of cementite, Fe3C, in thin iron foils has been studied under in-situ conditions in the temperature range from 500 °C to 600 °C by means of Mössbauer spectroscopy in time-resolved experiments at different carbon activities. Overall, the reaction shows a two-step process exhibiting two different kinetic regimes, which can be well described on the basis of a modified Johnson–Mehl–Avrami kinetics with a characteristic parameter n = 3/2. Deviations from this behaviour, occurring in the early stages of the reaction, are discussed.

Changes of the nutrient loads of the Danube since the late eighties: An analysis based on long term changes along the whole Danube River and its main tributaries

The Danube nutrient loads are affected by human impacts mainly from agriculture and wastewater discharges. Knowledge about the Danube nutrient loads and the changes of these loads over time is essential for understanding the changes within the ecosystem of the Black Sea, induced by these loads. The paper shows the long term changes of the nutrient load along the Danube estimated by measurements from different countries and institutions. The results show large differences between Dissolved Inorganic Nitrogen (DIN) and Total Phosphorus (TP). For TP, the Danube River loads show a strong decrease since 1988-1992, especially in the Middle and Lower basin. This change is probably partly connected to the dramatic economic changes in the Middle and Eastern European countries following the collapse of the communist system. The DIN load does not show a decreasing trend in the last decade. The data indicate that there may be a decreasing trend in the anthropogenic emissions, but that such a trend is counteracted by a significantly increasing trend of the Danube discharge in the last decade. The accuracy of the available data is analysed in the paper as well.

Wilson's Disease: a challenge of diagnosis. The 5-year experience of a tertiary centre

BACKGROUND

Because molecular diagnosis is considered impractical and no patognomonic features have been described, diagnosis of Wilson's disease (WD) using clinical and biochemical findings is still challenging.

PATIENTS AND METHOD

We analysed predictive factors for the diagnosis in 55 patients with WD diagnosed in our centre between 1st January 1999 and 1st April 2004. All patients presented predominant liver disease classified as: 1) asymptomatic, found incidentally, 2) chronic hepatitis or cirrhosis, or 3) fulminant hepatic failure. Diagnosis was considered as classic (two out of the three following criteria: 1) serum ceruloplasmin < 20 mg/dl, 2) the presence of Kayser-Fleischer rings and/or 3) hepatic copper > 250 mg/g dry weight liver tissue), and non-classic (clinical manifestations plus laboratory parameters suggesting impaired copper metabolism). The association between the predictive factors and non-classic diagnosis was assessed based on the level of statistical significance (p value<0.05) associated with the chi-squared test in contingency tables. Multivariate analysis was performed by logistic regression using SPSS 10.

RESULTS

There were 31 males (56.3%) and 24 females (43.7%) with the mean age at diagnosis of 20.92 +/- 9.97 years (4-52 years); 51 patients (92.7%) were younger than 40 years. Asymptomatic WD was diagnosed in 14 patients (25.4%), chronic liver disease due to WD in 29 patients (52.8%) and fulminant hepatic failure in 12 patients (21.8%). The classic diagnosis was made in 32 patients (58.18%). In the univariate analysis the non-classic diagnosis was associated with: age>18 years (p=0.03), increased copper excretion (p<0.0001), Coombs-negative hemolysis (p=0.03), absence of neurological manifestations (p<0.0001). Multivariate analysis identified age over 18 years, increased urinary copper, and isolated hepatic involvement as independent predictors.

CONCLUSION

In clinical practice, WD should be considered also in patients who do not fulfil classic criteria. Independent factors associated with non-classic diagnosis were age over 18 years, increased cupruresis and isolated liver disease.

Solving the ultranonlocality problem in time-dependent spin-density-functional theory

It has been known for some time that the exchange-correlation potential in time-dependent density-functional theory is an intrinsically nonlocal functional of the density as soon as one goes beyond the adiabatic approximation. In this paper we show that a much more severe nonlocality problem, with a completely different physical origin, plagues the exchange-correlation potentials in time-dependent spin-density functional theory. We show how the use of the spin current density as a basic variable solves this problem, and we provide an explicit local expression for the exchange-correlation fields as functionals of the spin currents.

Bone phenotype of the aromatase deficient mouse

Estrogens are important for normal bone growth and metabolism. The mechanisms are incompletely understood. Thus, we have undertaken characterization of the skeletal phenotype of aromatase (ArKO) deficient mice. No abnormalities have been noted in skeletal patterning in newborns. Adult ArKO mice show decreased femur length and decreased peak Bone Mineral Density (BMD) with accelerated bone loss by 7 months of age in females. Magnetic resonance microscopy (MR) and microCT (microCT) imaging disclosed decreased cancellous connectivity and reduced cancellous bone volume in ArKO females. Bone formation rate (BFR) is increased in ArKO females and decreased in ArKO males. Estradiol therapy reverses these changes. This anabolic effect of estradiol in the male skeleton is supported by 18-F- Positron Emission Tomography (PET) imaging, which clearly demonstrates decreased spinal uptake, but marked increase after estradiol therapy. Serum IGF-1 levels are high in young female ArKO mice but low in young ArKO males. The reduced BMD in ArKO females, despite the presence of elevated serum IGF 1, suggests that other mechanism(s) are operative. There is increased B-cell lymphopoiesis in adult female ArKO bone marrow cells. These results show that ArKO mice show the effects of estrogen deficiency on bone growth, mass, metabolism, microarchitecture and the hematopoietic microenvironment.

Tumor oxygen dynamics with respect to growth and respiratory challenge: investigation of the Dunning prostate R3327-HI tumor

We recently described a novel approach to measuring regional tumor oxygen tension using (19)F nuclear magnetic resonance echo planar imaging relaxometry (FREDOM) of hexafluorobenzene. We have now applied this technique to evaluate in detail the oxygen tension dynamics in the relatively slowly growing, moderately well-differentiated Dunning prostate R3327 HI rat tumor with respect to tumor growth and respiratory challenge. Seven individual tumors were assessed repeatedly over a period of 5 weeks ( approximately 4 volume doubling times). For small tumors (<1 cm(3)), the mean pO(2) ranged from 28 to 44 Torr under baseline conditions, decreasing to less than 10 Torr when the tumors reached 5 to 6 cm(3), with a strong inverse correlation between the baseline tumor oxygen tension and the tumor size. The hypoxic fraction (defined as the percentage of the voxels with pO(2) <10 Torr) increased significantly with tumor growth. Administration of oxygen or carbogen produced a significant increase (P < 0.0001) in tumor oxygenation at all stages of tumor growth. Most interestingly, even regions of these tumors that were initially poorly oxygenated responded rapidly, and significantly, to respiratory intervention, in contrast to the behavior of the faster-growing rat prostate tumors investigated previously.

Prognostic radiology: quantitative assessment of tumor oxygen dynamics by MRI

It is generally recognized that tumor hypoxia has a strong influence over therapeutic outcome in the clinic. The authors have developed an oximetry approach using 19F echo planar magnetic resonance imaging-FREDOM (Fluorocarbon Relaxometry using Echoplanar imaging for Dynamic Oxygen Mapping), which reveals dynamic changes based on sequential maps of regional tumor PO2. Preclinical investigations focused on diverse sublines of the Dunning prostate R3327 tumor. As expected, intratumoral heterogeneity was considerable. However, large tumors (>3.5 cm3) were significantly less well oxygenated than smaller tumors (<2 cm3). Faster growing, less differentiated tumors were less well oxygenated than size-matched tumors of slower growing sublines. The greatest potential of this technique is the ability to follow the fate of individual tumor regions with respect to interventions. For each subline, there was a significant response to respiratory challenge with oxygen for initially well-oxygenated regions (baseline PO2 > 10 mm Hg). More interestingly, subline dependent behavior was found for initially hypoxic regions that correlated with rate of growth. The authors believe the FREDOM approach is essentially ripe for translation to the clinic. This approach could help to identify patients with hypoxic tumors and indicate the feasibility of manipulating tumor characteristics through adjuvant interventions to improve therapeutic response.

Transient adhesion of platelets in pump-oxygenator systems: influence of SMA and nitric oxide treatments

We employed gamma scintigraphy to quantify the transient accumulations of platelets in pump-oxygenator systems employed in cardiopulmonary bypass (CPB). A flat sheet microporous polypropylene membrane oxygenator (Cobe Duo) was employed, with and without siloxane/caprolactone oligomer coating (SMA) (n = 8 each). The effect of nitric oxide gas infusion on platelet deposition was also evaluated for the uncoated Cobe Duo system (n = 10 each). Scintigraphic images of radiolabelled cells were obtained and converted to numbers of all platelets, labeled and unlabeled, adhering to the pump and oxygenator surfaces. These numbers were compared, by study group, for a 90-min period of normothermic CPB in the adult pig, employing standard prime and anticoagulation regimens. Platelets adhered in large numbers to control oxygenators, reaching maxima (> 20% of the circulating platelet mass) 30 min following institution of CPB, and decreasing for the duration of CPB. SMA treatment significantly decreased platelet adhesion following a 5-10-min transient accumulation period. Nitric oxide infusion significantly reduced platelet adhesion throughout the CPB period. Platelet accumulations on the high fluid shear centrifugal pump surfaces increased monotonically to maxima at about the same time as for the oxygenators, but did not decrease thereafter. Higher platelet surface densities were observed on the centrifugal pump surfaces than on the oxygenator surfaces. CPB with the untreated circuit tended to reduce circulating platelet counts vs theoretical values based on hemodilution alone. In contrast, SMA significantly increased the circulating platelet count versus the untreated control group. These results indicate that platelet adherence to the foreign surfaces of CPB equipment are influenced in characteristic ways by time and fluid shear. SMA treatment and nitric oxide infusion both reduce platelet adhesion to oxygenator surfaces. SMA treatment spares these cells for the circulation.

Tumor oximetry: demonstration of an enhanced dynamic mapping procedure using fluorine-19 echo planar magnetic resonance imaging in the Dunning prostate R3327-AT1 rat tumor

PURPOSE

We have developed an enhanced approach to measuring regional oxygen tension (pO(2)) dynamics in tumors. The technique is demonstrated in a group of 8 Dunning prostate rat tumors (R3327-AT1) with respect to respiratory challenge.

METHODS AND MATERIALS

Hexafluorobenzene was injected directly into the tumors of anesthetized rats. (19)F nuclear magnetic resonance echo planar imaging relaxometry was performed to obtain maps of regional tumor oxygenation under baseline conditions and when the inhaled gas was changed to oxygen or carbogen.

RESULTS

Sequential pO(2) maps required 8 min, with a typical precision of 1-3 torr at 30-100 individual regions across a tumor. When rats breathed 33% oxygen, distinct heterogeneity was observed for baseline oxygenation in each tumor with pO(2) values ranging from hypoxic to greater than 100 torr. Larger tumors showed significantly lower baseline pO(2). Respiratory challenge with oxygen or carbogen produced significant increases in tumor oxygenation with a close correlation between the response to each gas at individual locations. Regions of both small and large tumors responded to respiratory challenge, but the rate was generally much faster in initially well-oxygenated regions.

CONCLUSIONS

Regional pO(2) was assessed quantitatively and the response of multiple individual tumor regions observed simultaneously with respect to interventions.

Annexin V binds to positively selected B cells

Recombinant annexin V (rAnV) has been used in flow cytometry to identify cells undergoing apoptosis, based on its ability to bind to phosphatidylserine, a negatively charged lipid normally restricted to the cytoplasmic face of the plasma membrane but externalized early during apoptosis. When we stained murine bone marrow (BM) cells with fluorescently labeled rAnV, we found that a surprisingly large fraction of BM B cells bearing selectable transgenic Ag receptors bind significant amounts of rAnV, but that these cells are not apoptotic. Here, we show that binding of rAnV to developing B cells in normal mice correlates with B cell receptor-dependent selection events at several stages of development within both B-1 and B-2 cell subsets. In fact, nearly all B-1 B cells and splenic marginal zone B cells bind rAnV, suggesting that the externalization of phosphatidylserine occurs once mature B cells are selected through BCR-mediated signaling. However, this plasma membrane alteration is apparently not shared by all lymphocytes, because we did not find a parallel population of rAnV-binding viable T cells in vivo in normal or TCR transgenic mice. We also show that BM stromal cell lines can influence the extent of rAnV binding by viable BM B cells during coculture in vitro. We suggest that rAnV detects a potentially important membrane alteration that occurs as B cells develop in the BM and are readied for export to the peripheral lymphoid organs and again among mature B cells recruited to the marginal zone or the B-1 compartment.

Noninvasive investigation of blood oxygenation dynamics of tumors by near-infrared spectroscopy

The measurement of dynamic changes in the blood oxygenation of tumor vasculature could be valuable for tumor prognosis and optimizing tumor treatment plans. In this study we employed near-infrared spectroscopy (NIRS) to measure changes in the total hemoglobin concentration together with the degree of hemoglobin oxygenation in the vascular bed of breast and prostate tumors implanted in rats. Measurements were made while inhaled gas was alternated between 33% oxygen and carbogen (95% O(2), 5% CO(2)). Significant dynamic changes in tumor oxygenation were observed to accompany respiratory challenge, and these changes could be modeled with two exponential components, yielding two time constants. Following the Fick principle, we derived a simplified model to relate the time constants to tumor blood-perfusion rates. This study demonstrates that the NIRS technology can provide an efficient, real-time, noninvasive means of monitoring the vascular oxygenation dynamics of tumors and facilitate investigations of tumor vascular perfusion. This may have prognostic value and promises insight into tumor vascular development.

Enhancing hepatocyte adhesion by pulsed plasma deposition and polyethylene glycol coupling

Decreased hepatocyte adhesion to polymeric constructs limits the function of tissue engineered hepatic assist devices. We grafted adhesion peptides (RGD and YIGSR) to polycaprolactone (PCL) and poly-L-lactic acid (PLLA) in order to mimic the in vivo extracellular matrix and thus enhance hepatocyte adhesion. Peptide grafting was done by a novel technique in which polyethylene glycol (PEG)-adhesion peptide was linked to allyl-amine coated on the surface of PCL and PLLA by pulsed plasma deposition (PPD). Peptide grafting density, quantified by radio-iodinated tyrosine in YIGSR, was 158 fmol/cm(2) on PLLA and 425 fmol/cm(2) on PCL surfaces. The adhesion of hepatocytes was determined by plating 250,000 hepatocytes/well (test substrates were coated on 12 well plates) and quantifying the percentage of adhered cells after 6 h by MTT assay. Adhesion on PCL surfaces was significantly enhanced (p < 0.05) by both YIGSR (percentage of adhered cells = 53 +/- 7%) and RGD (53 +/- 12%) when compared to control surfaces (31 +/- 8%). Hepatocyte adhesion on PLLA was significantly (p < 0.05) enhanced on PLLA-PEG-RGD surfaces (76 +/- 14%) compared to control surfaces (42 +/- 19%) and more (68 +/- 25%) but not statistically significant (p = 0.15) on PLLA-PEG-YIGSR surfaces compared to control surfaces. These results indicate that hepatocyte adhesion to PCL and PLLA based polymeric surfaces can be enhanced by a novel adhesion peptide grafting technique using pulsed plasma deposition and PEG cross-linking.

Ethanol-induced translocation of cAMP-dependent protein kinase to the nucleus. Mechanism and functional consequences

Ethanol induces translocation of the catalytic subunit (Calpha) of cAMP-dependent protein kinase (PKA) from the Golgi area to the nucleus in NG108-15 cells. Ethanol also induces translocation of the RIIbeta regulatory subunit of PKA to the nucleus; RI and Cbeta are not translocated. Nuclear PKA activity in ethanol-treated cells is no longer regulated by cAMP. Gel filtration and immunoprecipitation analysis confirm that ethanol blocks the reassociation of Calpha with RII but does not induce dissociation of these subunits. Ethanol also reduces inhibition of Calpha by the PKA inhibitor PKI. Pre-incubation of Calpha with ethanol decreases phosphorylation of Leu-Arg-Arg-Ala-Ser-Leu-Gly (Kemptide) and casein but has no effect on the phosphorylation of highly charged molecules such as histone H1 or protamine. cAMP-response element-binding protein (CREB) phosphorylation by Calpha is also increased in ethanol-treated cells. This increase in CREB phosphorylation is inhibited by the PKA antagonist (R(p))-cAMPS and by an adenosine receptor antagonist. These results suggest that ethanol affects a cascade of events allowing for sustained nuclear localization of Calpha and prolonged CREB phosphorylation. These events may account for ethanol-induced changes in cAMP-dependent gene expression.