POS0181 EFFECT OF A MULTIDISCIPLINARY LIFESTYLE PROGRAM ON PATIENTS WITH METABOLIC SYNDROME-ASSOCIATED OSTEOARTHRITIS: THE PLANTS FOR JOINTS RANDOMIZED CONTROLLED TRIAL

Background

Metabolic syndrome with low grade inflammation is associated with chronic diseases including osteoarthritis (OA) (1). Nonpharmacological treatment with a combination of an intensive diet and exercise produced better results in people with osteoarthritis (OA) than either treatment alone (2). We further developed the concept of an integrated lifestyle intervention in people with metabolic syndrome-associated osteoarthritis (MSOA) by combining a whole food plant-based diet with physical activity and stress management.

Objectives

To determine the effect of a multidisciplinary lifestyle program on pain, stiffness, and physical function in patients with MSOA.

Methods

In the “Plants for Joints” (PFJ) parallel-arm, randomized clinical trial, patients with MSOA were assigned to the PFJ group or the control group. Patients with metabolic syndrome (according to NCEP criteria) and OA in the knee and/or hip (according to clinical ACR criteria) were eligible for participation. The PFJ group followed a 16-week lifestyle program based on a whole food plant-based diet, physical activity, and stress management in addition to usual care. The control group received usual care.

Prior to the start of the study, it was hypothesized that the lifestyle program would lower pain and stiffness and improve physical function, based on the Western Ontario and McMaster Universities Arthritis Index (WOMAC) score (primary outcome). Secondary outcomes included anthropometric, and metabolic markers. Patient partners selected the patient-reported outcome measures (PROMIS©) depression, fatigue, pain interference and physical function as additional secondary outcomes.

An intention-to-treat analysis with a linear mixed model, adjusted for baseline values (and age, sex, and body mass index [BMI] in additional analyses), was used to analyze the between-group differences of continuous outcomes.

Results

Of the 92 people screened, 66 were randomized and 64 completed the study (PFJ group: n = 32). Participants were 84% female, had a mean (SD) age of 63 (6) and a mean (SD) BMI of 33 (5) kg/m2. After 16 weeks the PFJ group had a mean 11-point greater improvement of the total WOMAC score (range 0-96) over time (95% CI 6 to 16; p = 0.0001) with significant improvements in all three components pain, stiffness, and physical function compared to the control group (Figure 1). Also, compared to the control group, the PFJ group lost more body weight (–3.9 kg, 95% CI –5.8 to –2.0; p < 0.001), fat mass as measured with dual-energy x-ray absorptiometry (–3.9 kg, 95% CI –5.3 to –2.5; p < 0.0001) and waist circumference (–4 cm, 95% CI –7 to –1; p = 0.01). HbA1c and fasting glucose improved in the PFJ versus control group, but not significantly. LDL decreased by 0.38 mmol/l (95% CI 0.07 to 0.69; p = 0.02) and triglycerides by 0.32 (95% CI 0.01 to 0.63; p = 0.04) in favour of the PFJ group. HDL and blood pressure remained unchanged. Of the patient reported outcome measures (PROMIS©) only fatigue showed a significant improvement. Based on a baseline mean (SD) value of 55 for all the participants, fatigue improved with 4 (95% CI 1 to 6; p = 0.03) in the PFJ group when compared with the control group. Additional analyses adjusted for age, sex, and BMI did not lead to different outcomes.

No serious adverse events occurred.

Conclusion

The 16-week “Plants for Joints” lifestyle program substantially decreased pain and stiffness and improved physical function in people with metabolic syndrome associated osteoarthritis of hip and/or knee. In addition, following the lifestyle program resulted in lower weight, fat mass and smaller waist circumference in comparison with usual care.

References

[1]Furman D et al. Chronic inflammation in the etiology of disease across the life span. Nat Med. 2019;25(12):1822-32.

[2]Messier SP et al. Effects of intensive diet & exercise on knee joint loads, inflammation, and clinical outcomes among overweight and obese adults with knee OA. JAMA. 2013;310(12):1263-73.

Disclosure of Interests

Wendy Walrabenstein: None declared, Carlijn Wagenaar: None declared, Marike van der Leeden: None declared, Martijn Gerritsen Grant/research support from: Menarini, Grunenthal and Horizon Pharma, Martin van der Esch: None declared, Dirkjan van Schaardenburg: None declared

Clinical guidance for podiatrists in the management of foot problems in rheumatic disorders: evaluation of an educational programme for podiatrists using a mixed methods design

Background

Foot and ankle problems are common in rheumatic disorders and often lead to pain and limitations in functioning, affecting quality of life. There appears to be large variability in the management of foot problems in rheumatic disorders across podiatrists. To increase uniformity and quality of podiatry care for rheumatoid arthritis (RA), osteoarthritis (OA), spondyloarthritis (SpA), and gout a clinical protocol has been developed.

Research objectives

[1] to evaluate an educational programme to train podiatrists in the use of the protocol and [2] to explore barriers and facilitators for the use of the protocol in daily practice.

Method

This study used a mixed method design and included 32 podiatrists in the Netherlands. An educational programme was developed and provided to train the podiatrists in the use of the protocol. They thereafter received a digital questionnaire to evaluate the educational programme. Subsequently, podiatrists used the protocol for three months in their practice. Facilitators and barriers that they experienced in the use of the protocol were determined by a questionnaire. Semi-structured interviews were held to get more in-depth understanding.

Results

The mean satisfaction with the educational programme was 7.6 (SD 1.11), on a 11 point scale. Practical knowledge on joint palpation, programme variation and the use of practice cases were valued most. The protocol appeared to provide support in the diagnosis, treatment and evaluation of foot problems in rheumatic disorders and the treatment recommendations were clear and understandable. The main barrier for use of the protocol was time. The protocol has not yet been implemented in the electronic patient file, which makes it more time consuming. Other experienced barriers were the reimbursement for the treatment and financial compensation.

Conclusions

The educational programme concerning the clinical protocol for foot problems in rheumatic disorders appears to be helpful for podiatrists. Podiatrists perceived the protocol as being supportive during patient management. Barriers for use of the protocol were identified and should be addressed prior to large scale implementation. Whether the protocol is also beneficial for patients, needs to be determined in future research.

Neutrophil activation identifies patients with active polyarticular gout

Background

Gout is the most prevalent inflammatory arthritis in developed countries. A gout flare is mediated by phagocytosis of monosodium urate crystals by macrophages and neutrophils leading to subsequent activation of neutrophils contributing to synovitis, local joint destruction, and systemic inflammation. We hypothesize that biomarkers from activated neutrophils reflect gout disease activity.

The objective of this study therefore was to investigate the clinical utility of neutrophil-derived biomarkers in gout disease activity.

Methods

Plasma samples from 75 gout patients participating in the “Reade gout cohort Amsterdam” were compared with 30 healthy controls (HC). Levels of neutrophil extracellular traps (NETs) and neutrophil activation markers (calprotectin and peroxidase activity) were analyzed by ELISA and fluorimetry, compared to healthy controls, and related to markers of inflammation and disease activity.

Results

Levels of NETs, as well as neutrophil activation markers, were increased in gout patients compared to HC (p < 0.01). No associations were found between markers of cell death (cell-free DNA and NETs) and disease activity. Cell-free levels of genomic DNA were elevated among gout patients compared to HC (p < 0.05) and related to the number of gout attacks in the last year (β = 0.35, p < 0.01). Peroxidase activity correlated with disease activity (RAPID score: β = 0.49, p < 0.01, MHAQ: β = 0.66, p < 0.01) and inflammation markers (CRP: β = 0.25, p = 0.04, and ESR: β = 0.57, p < 0.001). Involvement of ankle or wrist resulted in significant higher peroxidase levels compared to mono-articular disease (β = 0.34, p < 0.01), indicating that peroxidase activity is a marker of poly-articular gout. Calprotectin (S100A8/A9) correlated with the inflammation marker CRP (β = 0.23, p = 0.05) and morning stiffness, especially in patients with chronic poly-articular gout (β = 0.71, p < 0.01).

Conclusions

Neutrophil activation markers are associated with characteristics of active, polyarticular gout. Furthermore, NETs are present in the peripheral blood of gout patients. However, NETs do not associate with markers of disease activity or inflammation. Future research should point out if peroxidase and calprotectin could be used in clinical practice as biomarkers for monitoring gout disease activity.

Ring sideroblasts in AML are associated with adverse risk characteristics and have a distinct gene expression pattern

Ring sideroblasts (RS) emerge as result of aberrant erythroid differentiation leading to excessive mitochondrial iron accumulation, a characteristic feature for myelodysplastic syndromes (MDS) with mutations in the spliceosome gene SF3B1. However, RS can also be observed in patients diagnosed with acute myeloid leukemia (AML). The objective of this study was to characterize RS in patients with AML. Clinically, RS-AML is enriched for ELN adverse risk (55%). In line with this finding, 35% of all cases had complex cytogenetic aberrancies, and TP53 was most recurrently mutated in this cohort (37%), followed by DNMT3A (26%), RUNX1 (25%), TET2 (20%), and ASXL1 (19%). In contrast to RS-MDS, the incidence of SF3B1 mutations was low (8%). Whole-exome sequencing and SNP array analysis on a subset of patients did not uncover a single genetic defect underlying the RS phenotype. Shared genetic defects between erythroblasts and total mononuclear cell fraction indicate common ancestry for the erythroid lineage and the myeloid blast cells in patients with RS-AML. RNA sequencing analysis on CD34+ AML cells revealed differential gene expression between RS-AML and non RS-AML cases, including genes involved in megakaryocyte and erythroid differentiation. Furthermore, several heme metabolism-related genes were found to be upregulated in RS- CD34+ AML cells, as was observed in SF3B1mut MDS. These results demonstrate that although the genetic background of RS-AML differs from that of RS-MDS, they have certain downstream effector pathways in common.

Rapamycin limits the growth of established experimental abdominal aortic aneurysms

OBJECTIVES

Abdominal aortic aneurysm (AAA) is a chronic inflammatory disease affecting 4-8% of men older than 60 years. No pharmacologic strategies limit disease progression, aneurysm rupture, or aneurysm-related death. We examined the ability of rapamycin to limit the progression of established experimental AAAs.

METHODS

AAAs were created in 10-12-week-old male C57BL/6J mice via the porcine pancreatic elastase (PPE) infusion method. Beginning 4 days after PPE infusion, mice were treated with rapamycin (5 mg/kg/day) or an equal volume of vehicle for 10 days. AAA progression was monitored by serial ultrasound examination. Aortae were harvested for histological analyses at sacrifice.

RESULTS

Three days after PPE infusion, prior to vehicle or rapamycin treatment, aneurysms were enlarging at an equal rate between groups. In the rapamycin group, treatment reduced aortic enlargement by 38%, and 53% at 3 and 10 days, respectively. On histological analysis, medial elastin and smooth muscle cell populations were relatively preserved in the rapamycin group. Rapamycin treatment also reduced mural macrophage density and neoangiogenesis.

CONCLUSION

Rapamycin limits the progression of established experimental aneurysms, increasing the translational potential of mechanistic target of rapamycin-related AAA inhibition strategies.

Knee joint stabilization therapy in patients with osteoarthritis of the knee: a randomized, controlled trial

OBJECTIVE

To investigate whether an exercise program, initially focusing on knee stabilization and subsequently on muscle strength and performance of daily activities is more effective than an exercise program focusing on muscle strength and performance of daily activities only, in reducing activity limitations in patients with knee osteoarthritis (OA) and instability of the knee joint.

DESIGN

A single-blind, randomized, controlled trial involving 159 knee OA patients with self-reported and/or biomechanically assessed knee instability, randomly assigned to two treatment groups. Both groups received a supervised exercise program for 12 weeks, consisting of muscle strengthening exercises and training of daily activities, but only in the experimental group specific knee joint stabilization training was provided. Outcome measures included activity limitations (Western Ontario and McMaster Universities Osteoarthritis Index - WOMAC physical function, primary outcome), pain, global perceived effect and knee stability.

RESULTS

Both treatment groups demonstrated large (∼20-40%) and clinically relevant reductions in activity limitations, pain and knee instability, which were sustained 6 months post-treatment. No differences in effectiveness between experimental and control treatment were found on WOMAC physical function (B (95% confidence interval - CI) = -0.01 (-2.58 to 2.57)) or secondary outcome measures, except for a higher global perceived effect in the experimental group (P = 0.04).

CONCLUSIONS

Both exercise programs were highly effective in reducing activity limitations and pain and restoring knee stability in knee OA patients with instability of the knee. In knee OA patients suffering from knee instability, specific knee joint stabilization training, in addition to muscle strengthening and functional exercises, does not seem to have any additional value. Dutch Trial Register (NTR) registration number: NTR1475.

The association between reduced knee joint proprioception and medial meniscal abnormalities using MRI in knee osteoarthritis: results from the Amsterdam osteoarthritis cohort

BACKGROUND

Osteoarthritis (OA) of the knee is characterized by pain and activity limitations. In knee OA, proprioceptive accuracy is reduced and might be associated with pain and activity limitations. Although causes of reduced proprioceptive accuracy are divergent, medial meniscal abnormalities, which are highly prevalent in knee OA, have been suggested to play an important role. No study has focussed on the association between proprioceptive accuracy and meniscal abnormalities in knee OA.

OBJECTIVE

To explore the association between reduced proprioceptive accuracy and medial meniscal abnormalities in a clinical sample of knee OA subjects.

METHODS

Cross-sectional study in 105 subjects with knee OA. Knee proprioceptive accuracy was assessed by determining the joint motion detection threshold in the knee extension direction. The knee was imaged with a 3.0 T magnetic resonance (MR) scanner. Number of regions with medial meniscal abnormalities and the extent of abnormality in the anterior and posterior horn and body were scored according to the Boston-Leeds Osteoarthritis Knee Score (BLOKS) method. Multiple regression analyzes were used to examine whether reduced proprioceptive accuracy was associated with medial meniscal abnormalities in knee OA subjects.

RESULTS

Mean proprioceptive accuracy was 2.9° ± 1.9°. Magnetic resonance imaging (MRI)-detected medial meniscal abnormalities were found in the anterior horn (78%), body (80%) and posterior horn (90%). Reduced proprioceptive accuracy was associated with both the number of regions with meniscal abnormalities (P < 0.01) and the extent of abnormality (P = 0.02). These associations were not confounded by muscle strength, joint laxity, pain, age, gender, body mass index (BMI) and duration of knee complaints.

CONCLUSION

This is the first study showing that reduced proprioceptive accuracy is associated with medial meniscal abnormalities in knee OA. The study highlights the importance of meniscal abnormalities in understanding reduced proprioceptive accuracy in persons with knee OA.

320EFFECT OF CYSTEAMINE DURING IN VITRO MATURATION ON FURTHER EMBRYONIC DEVELOPMENT AND POSTTHAW SURVIVAL OF IVP BOVINE EMBRYOS

The uptake of cysteamine by immature oocytes may facilitate the synthesis of glutathione (GSH) during in vitro maturation, as reported by Matos et al. (1995 Mol. Reprod. Dev. 42 432–436). GSH plays an important protective role in relation to reactive oxygen species generated by normal oxidative metabolism. This study investigated the effects of the presence of cysteamine during in vitro maturation on subsequent in vitro embryonic development and postthaw in vitro survival. Immature Cumulus-Oocyte-Complexes (COCs) were recovered from ovaries 6 to 8h after slaughter. COCs were matured in vitro for 22 to 24h in TCM199/FCS/LH/FSH supplemented either with or without cysteamine (0.1mM), Subsequently, matured oocytes were fertilized with frozen-thawed Percoll-separated semen and further cultured for seven days in SOFaaBSA. Morulae grade 1 (IETS) and blastocysts grades 1 and 2 (IETS) were frozen on Day 7 in 10% Glycerol using a conventional slow freezing procedure (Wagtendonk-de Leeuw et al. 1995 Cryobiology;; 32 157–167). In vitro survival was measured by rates of blastocyst formation and reexpansion at 24h and hatching/ed blastocysts at 72h in SOFaaBSA supplemented with 5% FCS. Results were analyzed by Chi-square analyses. The presence of cysteamine during in vitro maturation significantly affected the embryo production rate (19.4% and 24.0% for control and cysteamine at Day 7, respectively). The higher number of embryos at Day 7 was totally due to an increased number of blastocysts (Table 1); however, the distribution of embryos among the different quality grades was not affected. Addition of cysteamine did not affect the post thaw survival of the frozen/thawed embryos (85% v. 91% reexpansion and 33% v. 34% hatching/ed for control v. cysteamine, respectively). These results show that the presence of cysteamine during in vitro maturation, does affect further in vitro embryonic development, resulting in a higher embryo production rate. Embryo quality, expressed in morphological grades and postthaw survival rates, were not affected. A field trial will be conducted in order to confirm these results with ovum pick up-derived oocytes. Table 1 Effect of cysteamine during in vitro maturation on subsequent in vitro embryonic development of IVP bovine embryos (number of replicates: 5)

[Subcutaneously implantable glucose sensors in patients with diabetes mellitus; still many problems]

Despite considerable scientific efforts, no clinical method is currently available for the continuous monitoring of glucose in subcutaneous tissue fluid. In general, good results were obtained during in-vitro experiments with various implantable glucose sensors. However, after implantation these devices exhibited a progressive loss of sensor function. It is evident that the tissue reaction to the implanted sensor, especially the interactions at the sensor-tissue interface, plays an important role in this loss of function. Adequate strategies to improve in-vivo sensor performance can only be developed if there is a better understanding of the processes involved in sensor inactivation.

Splenic abscess caused by Peptostreptococcus species, diagnosed with the aid of abdominal computerized tomography and treated with percutaneous drainage and antibiotics: a case report

We describe herein a 63-year-old patient with a splenic abscess due to Peptostreptococcus spp., diagnosed with the aid of abdominal computerised tomography and treated with ultra-sound guided percutaneous drainage and antibiotics. The bacteriological characteristics of splenic abscesses are discussed.

Wound healing around bone-anchored percutaneous devices in experimental diabetes mellitus

The objective of this investigation was to study the influence of impaired wound healing on the tissue response to bone-anchored percutaneous devices. For this reason, diabetes mellitus was induced in rabbits with alloxan. Untreated rabbits were used as controls. Skin-penetrating titanium implants were inserted in the tibial bone of diabetic and healthy animals. The enossal part of half of the implants was provided with a thin magnetron-sputtered calcium-phosphate coating. The soft-tissue and bone response was evaluated clinically, histologically, and histomorphometrically. We did not observe more infectious complications in diabetic animals. Furthermore, histological analysis revealed no differences in soft-tissue response between diabetic and healthy animals. A close bone-implant contact was observed for all implants. Nevertheless, the density of cortical bone around the implants was clearly lower in diabetic animals compared with control animals. In control rabbits, but not diabetic animals, coated implants showed more downgrowth of bone into the marrow cavity than uncoated ones. In general, diabetes mellitus was shown to have no adverse effect on the clinical performance of the percutaneous devices. We think that this is due to the good fixation of the implants in diabetic as well as control animals. Therefore, we conclude that the presence of impaired healing in chronic health disorders like diabetes is no contra-indication for the anchorage of percutaneous implants in cortical bone.

A percutaneous device as model to study the in vivo performance of implantable amperometric glucose sensors

Glucose kinetics were investigated in subcutaneous tissue of rabbits, in which a percutaneous device was implanted. The device was used for collection of tissue fluid and as carrier of an amperometric glucose sensor. Changes in glycaemia were reflected in subcutaneous tissue fluid. However, a limited number of responses of the implanted sensors were observed. Histologic evaluation showed thin fibrous capsules surrounding the implants. Accumulations of inflammatory cells were observed inside the subcutaneous chamber. The experiments again showed that changes in blood glucose concentration can be measured in subcutaneous tissue fluid collected with a percutaneous device. Nevertheless, implanted glucose sensors could not reliably monitor these changes. Supported by our histological observations and sufficient in vitro performance, we suppose that the cellular reaction to the sensor plays an important role in this poor in vivo performance. In combination with adsorption of tissue fluid proteins, this results in a reversible deactivation of implanted sensors. The exact mechanisms involved in this process are currently unknown and need further investigation.

[Snijders-Oomen Nonverbal Intelligence Test: useful for the elderly?]

The feasibility of the SON-R 5 1/2-17, a non-verbal intelligence test for deaf children, was investigated in a group of older adults, with a view to the future use of the test in older neurological patients. In a group of 58 healthy elderly persons intelligence was measured with the SON, the Raven Progressive Matrices and a Dutch reading test. The subjects were also asked for their subjective judgements of the tests. The SON-R 5 1/2-17 appears to be a user-friendly test. The high correlations between the subtests, and between the SON and other measures of intelligence suggest that the SON is a valid test for measuring fluid intelligence in elderly persons. The existing norms are not suitable when the SON is used in elderly people, new norms for adults should therefore be developed.

Influence of inflammatory cells and serum on the performance of implantable glucose sensors

The objective of this investigation was to evaluate the influence of polymorphonuclear granulocytes on the performance of uncoated and cellulose acetate/Nafion coated amperometric glucose sensors in vitro. The response of these sensors was also investigated in serum. Uncoated and coated sensors showed lower sensitivities to glucose, with a significant drift in sensor output upon exposure to serum or leukocytes. Although the use of a coating resulted in higher sensitivity, the progressive loss of output was not completely prevented. Stimulated granulocytes were shown to excrete components, probably catalase and myeloperoxidase, which consumed the hydrogen peroxide formed by the oxidation of glucose. In addition, adsorbed serum proteins formed a diffusional barrier for glucose. Furthermore, serum was found to contain low-molecular weight components that alone inhibited glucose oxidase activity. Based on preliminary electrochemical results, we postulate that rabbit serum contains oxidizing substrates that compete with molecular oxygen for the acceptance of electrons from the oxidized enzyme. Consequently, future efforts should be aimed at elucidating the mechanisms involved in the interference of unknown serum components with electron transfer. In addition, further investigations have to be performed to develop an outer membrane that minimizes protein adsorption as well as the actions of inflammatory cells.

The influence of impaired wound healing on the tissue reaction to percutaneous devices using titanium fiber mesh anchorage

The objective of this investigation was to study the influence of impaired wound healing on the soft-tissue response to percutaneous devices using titanium fiber mesh anchorage. For this reason, diabetes mellitus was induced in rabbits with alloxan. Untreated rabbits were used as controls. Two implant types were inserted subcutaneously: two-stage percutaneous devices as well as separate titanium fiber mesh sheets. The soft-tissue response to both implants was assessed by clinical, histologic, and histomorphometric evaluation. Clinically, we observed a higher number of infectious complications around percutaneous implants in diabetic animals. Histologic and histomorphometric analyses revealed that severe diabetes effected matrix maturation and delayed neovascularization (p<0.05). We also observed higher numbers of inflammatory cells in the mesh porosity of percutaneous implants in severely diabetic animals (p = 0.09). Our results indicate that severe, uncontrolled diabetes negatively influences the maturity and neovascularization of connective tissue inside the fiber mesh porosity. The higher number of infectious complications in diabetic animals suggests that the presence of impaired healing conditions facilitates infection around skin penetrating devices.

A percutaneous device to study glucose kinetics in subcutaneous tissue fluid

In the current study subcutaneous glucose kinetics were investigated in tissue fluid collected with a percutaneous device (PD). PDs containing a subcutaneous tissue chamber were implanted subcutaneously in New Zealand white rabbits. Sintered titanium fiber mesh sheets were used for subcutaneous anchorage of the PD. The bottom of the subcutaneous tissue chamber was either covered with a titanium fiber mesh sheet, a cellulose acetate membrane, or left uncovered. Subcutaneous glucose kinetics were determined after injection of octreotide and glucagon. The tissue reaction to the implants was evaluated histologically. No dynamic relationship was observed between glycaemia and subcutaneous tissue fluid glucose for all membrane covered devices. Histological evaluation showed that the presence of a seroma cavity in combination with obstruction of the membrane prevented adjustment of the subcutaneous glucose concentration in response to changes in glycaemia. In the uncovered devices, on the other hand, changes in glycaemia were reflected in subcutaneous tissue fluid. Our results prove that it is possible to measure changes in the glucose concentration in subcutaneous tissue fluid collected with a percutaneous device. Therefore, we conclude that a percutaneous device has an application as model to study the in vivo performance of implantable glucose sensors. The use of porous membranes in such devices has to be avoided.

Biocompatibility evaluation of sol-gel coatings for subcutaneously implantable glucose sensors

The objective of the current investigation is to determine the soft-tissue biocompatibility of sol-gel matrices which can be used to optimize the properties of implantable glucose sensors. The biocompatibility of sol-gel matrices with heparin, dextran sulphate, Nafion, polyethylene glycol, and polystyrene sulphonate was examined in vitro in simulated body fluid and with cell culture experiments using human dermal fibroblasts. Finally, an in vivo study was performed. Therefore, sol-gel coated polystyrene discs were inserted subcutaneously in the back of rabbits. After 4 and 12 weeks, the implants with surrounding tissue were retrieved and processed histologically. In simulated body fluid, the formation of a granular calcium phosphate precipitate was observed. Cell proliferation on polyethylene glycol, Nafion, and heparin coated substrates was comparable to control samples and significantly higher than on dextran sulphate and polystyrene sulphate coated substrates. Light microscopic evaluation of the retrieved in vivo samples showed a fair tissue reaction to all materials. Histomorphometric analysis demonstrated that there were no differences in tissue response to the different sol-gel coatings. In conclusion, sol-gel matrices exhibit a fair biocompatibility both in vitro and in vivo. These results will form the basis for further research into the real merits of sol-gel coatings in optimizing the properties of subcutaneously implantable glucose sensors.

Quantification of murine endothelial cell adhesion molecules in solid tumors

Coordinated adhesive interactions between lymphocyte receptors and endothelial cell adhesion molecules (CAMs) are a prerequisite for effector cell entry into tumor stroma. Whereas the diminished leukocyte-endothelial cell interactions observed in tumor microvessels have been attributed to a reduced expression of endothelial CAMs, there is no quantitative data bearing on this issue. The dual-radiolabeled monoclonal antibody technique was used to quantify constitutive and tumor necrosis factor (TNF)-alpha-induced expression of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), ICAM-2, P-selectin, E-selectin, and platelet-endothelial cell adhesion molecule 1 (PECAM-1) in different vascular beds of normal (C57Bl/6) and RM-1 tumor-bearing mice. When corrected for endothelial surface area, the constitutive expression of selectins in tumor vessels was higher than that observed in other vascular beds. Both constitutive and induced expression of endothelial CAMs in peripheral vascular beds did not differ between normal and tumor-bearing mice. Within the tumor, the magnitude of the upregulation of P-selectin, ICAM-1, and VCAM-1 after TNF-alpha was similar to that within other vascular beds. E-selectin expression in tumors was refractory to TNF-alpha, whereas PECAM-1 and ICAM-2 expression were significantly reduced. Our findings suggest that the presence of a solid tumor does not influence endothelial CAM expression in other vascular beds and that the higher density of selectins in nonstimulated tumor vessels may promote the recruitment of rolling leukocytes in this tissue.

Performance of subcutaneously implanted glucose sensors for continuous monitoring

Despite a considerable amount of research attributed to the development of an implantable glucose sensor, to date there is no clinically applicable concept for continuous glucose monitoring. Investigations to validate the subcutaneous tissue for continuous glucose sensing mostly comprised short-term implantations of glucose sensors. Most implanted glucose sensors showed a significant drift in sensitivity over the implantation period. This bioinstability was not to be expected from the in vitro performance of the sensors. In this paper, the influence of possible failure mechanisms on the poor in vivo performance of subcutaneously implanted glucose sensors is reviewed.

Role of tumor necrosis factor and interferon gamma in endotoxin-induced E-selectin expression

Tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), potent inflammatory cytokines, are released by macrophages during endotoxin shock. However, the contribution of these cytokines to endotoxin-induced inflammation has not been defined. The expression of E-selectin, measured using the dual radiolabeled monoclonal antibody (mAb) technique, was monitored in different tissues of endotoxin-challenged wild-type and IFN-gamma-deficient mice receiving a mAb to TNF-alpha (TN3). A significant elevation in E-selectin expression occurred in all tissues of wild-type mice challenged with endotoxin. Injection of TN3 in wild-type mice significantly attenuated the endotoxin-induced up-regulation of E-selectin in all tissues (p < .05) except the pancreas. The level of reduction in endotoxin-induced E-selectin expression ranged between 30% in the stomach to 60% in the small intestine. E-selectin expression in endotoxin-challenged, IFN-gamma-deficient mice was significantly reduced in the small and large intestines, when compared with endotoxin-challenged wild-type mice. Although IFN-gamma deficiency had no effect on E-selectin expression in other tissues, administration of TN3 to endotoxin-challenged, IFN-gamma-deficient mice significantly reduced E-selectin expression to levels observed in endotoxin-challenged, wild-type mice that received TN3. These findings indicate that TNF-alpha is essential for achievement of maximal E-selectin expression in most vascular beds during endotoxemia, whereas the contribution of IFN-gamma is largely confined to the small intestine.

Evaluation of the tissue reaction to a percutaneous access device using titanium fibre mesh anchorage in goats

The tissue reaction to a percutaneous access device, applicable as a carrier for an implantable glucose sensor, was evaluated in goats. Titanium fibre mesh structures were used for anchorage of the device in superficial as well as deeper soft-tissue locations. The percutaneous part was subcutaneously anchored with a fibre mesh sheet. The distal part was placed intraperitoneally and anchored in deeper soft-tissue layers using a fibre mesh cuff. All implants showed good healing with the surrounding tissue. Histological evaluation showed that the subcutaneous fibre mesh sheets and peritoneal fibre mesh cuffs were filled with immature connective tissue, generally free of inflammation. Problems concerning disconnection of the silicone catheter from the titanium holding element and filling of part of the peritoneal fibre mesh cuff with silicone glue have to be overcome by more appropriate preclinical testing and improved implant design. Our results demonstrate that titanium fibre mesh structures can be used effectively for soft-tissue anchorage of percutaneous access devices. A sufficient ingrowth of connective tissue was obtained in superficial as well as in deeper soft-tissue layers. The access device could have application as a carrier for an implantable glucose sensor for glucose monitoring in different tissue compartments.

Performance of subcutaneously implanted glucose sensors: a review

Despite a considerable amount of research attributed to the development of an implantable glucose sensor, to date there is no clinically applicable concept for continuous glucose monitoring. Investigations to validate the subcutaneous tissue for continuous glucose sensing mostly comprise short-term implantations of glucose sensors. Most implanted glucose sensors showed a significant decay in sensitivity over the implantation period. This bioinstability was not to be expected from the in vitro performance of the sensors. In this article, the influence of possible failure mechanisms on the poor in vivo performance of subcutaneously implanted glucose sensors is reviewed.

Cytokine-induced VCAM-1 and ICAM-1 expression in different organs of the mouse

The dual radiolabeled mAb technique was used to quantify the constitutive and induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the microvasculature of different organs of the mouse. The constitutive expression of both adhesion molecules varied significantly between tissues, with ICAM-1 levels consistently higher than VCAM-1 in all tissues studied. Following systemic administration of endotoxin (LPS), an increased surface expression of both adhesion molecules occurred in most organs, with the largest increases for ICAM-1 (2 to 3x increase) noted in the heart, small intestine, and brain, while heart and small intestine exhibited the largest increases in LPS-induced VCAM-1 expression (2 to 5x increase). These responses occurred in the face of an unaltered expression of platelet endothelial cell adhesion molecule-1 (PECAM-1) in all tissues. TNF-alpha also elicited an increased expression of both adhesion molecules, with initial increases noted at 2 to 5 h, peak levels at 5 to 9 h, and a sustained elevation above baseline at 24 h. The TNF-alpha-induced increases in both ICAM-1 and VCAM-1 were dose dependent, with significant up-regulation noted at 5 microg/kg and maximal increases occurring at 10 to 25 microg/kg. These studies indicate that while there are significant quantitative differences in constitutive and induced expression of murine ICAM-1 and VCAM-1, the kinetics and dose-response characteristics of the two adhesion molecules to TNF-alpha are qualitatively similar.

Cytokine-induced VCAM-1 and ICAM-1 expression in different organs of the mouse

The dual radiolabeled mAb technique was used to quantify the constitutive and induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in the microvasculature of different organs of the mouse. The constitutive expression of both adhesion molecules varied significantly between tissues, with ICAM-1 levels consistently higher than VCAM-1 in all tissues studied. Following systemic administration of endotoxin (LPS), an increased surface expression of both adhesion molecules occurred in most organs, with the largest increases for ICAM-1 (2 to 3x increase) noted in the heart, small intestine, and brain, while heart and small intestine exhibited the largest increases in LPS-induced VCAM-1 expression (2 to 5x increase). These responses occurred in the face of an unaltered expression of platelet endothelial cell adhesion molecule-1 (PECAM-1) in all tissues. TNF-alpha also elicited an increased expression of both adhesion molecules, with initial increases noted at 2 to 5 h, peak levels at 5 to 9 h, and a sustained elevation above baseline at 24 h. The TNF-alpha-induced increases in both ICAM-1 and VCAM-1 were dose dependent, with significant up-regulation noted at 5 microg/kg and maximal increases occurring at 10 to 25 microg/kg. These studies indicate that while there are significant quantitative differences in constitutive and induced expression of murine ICAM-1 and VCAM-1, the kinetics and dose-response characteristics of the two adhesion molecules to TNF-alpha are qualitatively similar.

Palliative chemotherapy with CMF after the same adjuvant regimen for breast cancer. The Breast Cancer Study Group

BACKGROUND

The results of palliative chemotherapy with cyclophosphamide, methotrexate and 5-fluorouracil (CMF) in patients with advanced breast cancer who received adjuvant therapy with the same regimen were investigated.

RESULTS

Of 47 patients, 14 (30%) achieved an objective remission (median duration 9.5, range 5-21 months) and 8 (17%) stabilisation of disease (median duration 6, range 3-17 months). Objective remissions were observed in premenopausal as well as in postmenopausal women, in patients with all categories of dominant localisation of disease and regardless of the oestradiol receptor status of the primary tumour or eventual previous endocrine therapy. One of 4 and 13 of 43 patients who started palliative chemotherapy within or later than 12 months after the last adjuvant course obtained an objective remission. The median survival time from start of therapy of all treated patients was 12 (range 1-40) months. Patients with an objective remission or stable disease and patients with progressive disease had a median survival time of 20 (range 6-40) and 6 (range 1-35) months respectively (p < 0.0001).

CONCLUSIONS

Palliative treatment with CMF should not be rejected for patients who have relapsed after adjuvant chemotherapy with the same modality.

DT-diaphorase protects cells from the hypoxic cytotoxicity of indoloquinone EO9

Aerobic sensitivity to indoloquinone EO9 has been shown to correlate with cellular levels of the two-electron reducing enzyme DT-diaphorase. However, little is known about the relative roles of one- and two-electron reducing enzymes in the hypoxic cytotoxicity of EO9. We have characterised a panel of 23 human tumour cell lines for both bioreductive enzyme activities and aerobic sensitivity to EO9. Eight cell lines were then selected for a comparison of aerobic and hypoxic sensitivities. Activities of DT-diaphorase showed a wide range (> 10,000-fold), while activities of the one-electron reducing cytochrome b5 and cytochrome P450 reductases were generally lower and showed only a 15- and 25-fold range respectively. The aerobic cytotoxicity of EO9 was clearly related to the cellular levels of DT-diaphorase (r = 0.87), with higher levels giving increased sensitivity, but not to the levels of one-electron reducing enzymes. In contrast, there was no relationship between sensitivity to BCNU, cisplatin or the bioreductive agent SR 4233 (tirapazamine) and activities of any of these reducing enzymes. Under hypoxic conditions sensitivity to EO9 was markedly increased in cell lines with low levels of DT-diaphorase activity, while cell lines with high levels show only a small increase in sensitivity. This is reflected by a clear correlation (r = 0.98) between cellular DT-diaphorase activity and the ratio of aerobic to hypoxic sensitivity to EO9. However, we have now for the first time demonstrated an inverse correlation (r = 0.93) between the cellular activity of DT-diaphorase and hypoxic sensitivity to EO9, that is sensitivity decreases with increasing DT-diaphorase activity. Moreover, this correlation was lost when cells were exposed to drug in the presence of dicoumarol, supporting an involvement of DT-diaphorase in this relationship. These observations question the previously straightforward role for DT-diaphorase in the metabolic activation of EO9. Whereas DT-diaphorase is associated with increased toxicity in air, it appears to reduce the cytotoxicity of EO9 in hypoxic conditions. This suggests either that the one-electron reduction product of EO9 metabolism, the semiquinone, is more toxic than the two-electron reduction product, the hydroquinone, or that the hydroquinone is not cytotoxic and aerobic toxicity is due to the transient appearance of the semiquinone upon back oxidation of the hydroquinone.

Relative importance of DT-diaphorase and hypoxia in the bioactivation of EO9 by human lung tumor cell lines

PURPOSE

Although a number of bioreductive agents are substrates for purified DT-diaphorase the role of this enzyme in either activation or detoxification of these agents in the whole cell is unclear. The aim of this study was to determine the role of DT-diaphorase in the metabolic activation of EO9 under both aerobic and hypoxic conditions.

METHODS AND MATERIALS

A panel of lung cancer cell lines was used and drug sensitivity was determined by clonogenic or tetrazolium-dye-based assays. Activities of DT-diaphorase, cytochrome P450 and cytochrome b5 reductase were determined spectrophotometrically by following the reduction of cytochrome c.

RESULTS

Small-cell lung cancer cell lines showed a 600-fold range in DT-diaphorase activities but levels were much higher in three of the four non-small-cell lines. Activities of cytochromes P450 and b5 reductase were much lower than those of DT-diaphorase and showed much less variation between cell lines. There was no relationship between the activities of any of the enzymes and aerobic sensitivity to SR 4233, BCNU and cis-platin. Under aerobic conditions there was a clear correlation between DT-diaphorase activity and sensitivity to EO9. The small-cell lines were much more resistant to EO9 than the DT-diaphorase rich non-small-cell lines. A doxorubicin resistant variant of one of the small-cell lines (H69LX10) did not show cross resistance to EO9 but did show a small degree (3-fold) of cross resistance to SR 4233. Under hypoxic conditions, cell lines with high levels of DT-diaphorase showed only a small increase in sensitivity to EO9 (1.5-7 fold); cell lines with low levels of activity showed a 10-37-fold increase in sensitivity.

CONCLUSION

These results suggest that under hypoxic conditions, EO9 is metabolized by 1-electron reducing enzymes to a toxic species. This reduction product is oxygen sensitive but a similar degree of activation is obtained under aerobic conditions in cell lines with high levels of 2-electron reducing DT-diaphorase.