The Implant-Induced Foreign Body Response Is Limited by CD13-Dependent Regulation of Ubiquitination of Fusogenic Proteins

Implanted medical devices, from artificial heart valves and arthroscopic joints to implantable sensors, often induce a foreign body response (FBR), a form of chronic inflammation resulting from the inflammatory reaction to a persistent foreign stimulus. The FBR is characterized by a subset of multinucleated giant cells (MGCs) formed by macrophage fusion, the foreign body giant cells (FBGCs), accompanied by inflammatory cytokines, matrix deposition, and eventually deleterious fibrotic implant encapsulation. Despite efforts to improve biocompatibility, implant-induced FBR persists, compromising the utility of devices and making efforts to control the FBR imperative for long-term function. Controlling macrophage fusion in FBGC formation presents a logical target to prevent implant failure, but the actual contribution of FBGCs to FBR-induced damage is controversial. CD13 is a molecular scaffold, and in vitro induction of CD13KO bone marrow progenitors generates many more MGCs than the wild type, suggesting that CD13 regulates macrophage fusion. In the mesh implant model of FBR, CD13KO mice produced significantly more peri-implant FBGCs with enhanced TGF-β expression and increased collagen deposition versus the wild type. Prior to fusion, increased protrusion and microprotrusion formation accompanies hyperfusion in the absence of CD13. Expression of fusogenic proteins driving cell-cell fusion was aberrantly sustained at high levels in CD13KO MGCs, which we show is due to a novel CD13 function, to our knowledge, regulating ubiquitin/proteasomal protein degradation. We propose CD13 as a physiologic brake limiting aberrant macrophage fusion and the FBR, and it may be a novel therapeutic target to improve the success of implanted medical devices. Furthermore, our data directly implicate FBGCs in the detrimental fibrosis that characterizes the FBR.

Immunobiology of foreign body response to composite PLACL/gelatin electrospun nanofiber meshes with mesenchymal stem/stromal cells in a mouse model: Implications in pelvic floor tissue engineering and regeneration

Pelvic Organ Prolapse (POP) is a common gynaecological disorder where pelvic organs protrude into the vagina. While transvaginal mesh surgery using non-degradable polymers was a commonly accepted treatment for POP, it has been associated with high rates of adverse events such as mesh erosion, exposure and inflammation due to serious foreign body response and therefore banned from clinical use after regulatory mandates. This study proposes a tissue engineering strategy using uterine endometrium-derived mesenchymal stem/stromal cells (eMSC) delivered with degradable poly L-lactic acid-co-poly ε-caprolactone (PLACL) and gelatin (G) in form of a composite electrospun nanofibrous mesh (P + G nanomesh) and evaluates the immunomodulatory mechanism at the material interfaces. The study highlights the critical acute and chronic inflammatory markers along with remodelling factors that determine the mesh surgery outcome. We hypothesise that such a bioengineered construct enhances mesh integration and mitigates the Foreign Body Response (FBR) at the host interface associated with mesh complications. Our results show that eMSC-based nanomesh significantly increased 7 genes associated with ECM synthesis and cell adhesion including, Itgb1, Itgb2, Vcam1, Cd44, Cdh2, Tgfb1, Tgfbr1, 6 genes related to angiogenesis including Ang1, Ang2, Vegfa, Pdgfa, Serpin1, Cxcl12, and 5 genes associated with collagen remodelling Col1a1, Col3a1, Col6a1, Col6a2, Col4a5 at six weeks post-implantation. Our findings suggest that cell-based tissue-engineered constructs potentially mitigate the FBR response elicited by biomaterial implants. From a clinical perspective, this construct provides an alternative to current inadequacies in surgical outcomes by modulating the immune response, inducing angiogenesis and ECM synthesis during the acute and chronic phases of the FBR.

Recombinant sugarcane cystatin CaneCPI-5 down regulates inflammation and promotes angiogenesis and collagen deposition in a mouse subcutaneous sponge model

Cystatins are natural inhibitors of cysteine peptidases that are found practically in all living organisms. CaneCPI-5 is a sugarcane cystatin with inhibitory activity against human cathepsins B, K and L, which are cysteine proteases highly expressed in a variety of pathological conditions, usually marked by persistent inflammation and processing of the extracellular matrix. This work evaluated the effects of daily administration of the recombinant cystatin CaneCPI-5 [0.01, 0.1 or 1.0 μg in 10 μL of Phosphate-Buffered Saline (PBS)] on the inflammatory, angiogenic and fibrogenic components during chronic inflammatory response induced by subcutaneous sponge implants. The anti-inflammatory effect of treatment with CaneCPI-5 was confirmed by reduction of the levels of the pro-inflammatory mediators TNF-α, CXCL1 and CCL2/JE/MCP-1, as well as the activity of the myeloperoxidase and n-acetyl-β-D-glucosaminidase. Treatment with CaneCPI-5 promoted angiogenesis in the implants, increasing the production of cytokines VEGF and FGF and the formation of new blood vessels. Finally, the administration of the recombinant cystatin favored the production of the pro-fibrogenic cytokine TGF-β1 and collagen deposition next to the implants. Together, these results show the potential therapeutic application of CaneCPI-5 as an anti-inflammatory agent, capable of favoring angiogenesis and fibrogenesis processes, necessary for tissue repair.

Neuroinflammation, oxidative stress, and blood-brain barrier (BBB) disruption in acute Utah electrode array implants and the effect of deferoxamine as an iron chelator on acute foreign body response

The use of intracortical microelectrode arrays has gained significant attention in being able to help restore function in paralysis patients and study the brain in various neurological disorders. Electrode implantation in the cortex causes vasculature or blood-brain barrier (BBB) disruption and thus elicits a foreign body response (FBR) that results in chronic inflammation and may lead to poor electrode performance. In this study, a comprehensive insight into the acute molecular mechanisms occurring at the Utah electrode array-tissue interface is provided to understand the oxidative stress, neuroinflammation, and neurovascular unit (astrocytes, pericytes, and endothelial cells) disruption that occurs following microelectrode implantation. Quantitative real time polymerase chain reaction (qRT-PCR) was used to quantify the gene expression at acute time-points of 48-hr, 72-hr, and 7-days for factors mediating oxidative stress, inflammation, and BBB disruption in rats implanted with a non-functional 4 × 4 Utah array in the somatosensory cortex. During vascular disruption, free iron released into the brain parenchyma can exacerbate the FBR, leading to oxidative stress and thus further contributing to BBB degradation. To reduce the free iron released into the brain tissue, the effects of an iron chelator, deferoxamine mesylate (DFX), was also evaluated.

Graphene oxide enhances alginate encapsulated cells viability and functionality while not affecting the foreign body response

The combination of protein-coated graphene oxide (GO) and microencapsulation technology has moved a step forward in the challenge of improving long-term alginate encapsulated cell survival and sustainable therapeutic protein release, bringing closer its translation from bench to the clinic. Although this new approach in cell microencapsulation represents a great promise for long-term drug delivery, previous studies have been performed only with encapsulated murine C2C12 myoblasts genetically engineered to secrete murine erythropoietin (C2C12-EPO) within 160 µm diameter hybrid alginate protein-coated GO microcapsules implanted into syngeneic mice. Here, we show that encapsulated C2C12-EPO myoblasts survive longer and release more therapeutic protein by doubling the micron diameter of hybrid alginate-protein-coated GO microcapsules to 380 µm range. Encapsulated mesenchymal stem cells (MSC) genetically modified to secrete erythropoietin (D1-MSCs-EPO) within 380 µm-diameter hybrid alginate-protein-coated GO microcapsules confirmed this improvement in survival and sustained protein release in vitro. This improved behavior is reflected in the hematocrit increase of allogeneic mice implanted with both encapsulated cell types within 380 µm diameter hybrid alginate-protein-coated GO microcapsules, showing lower immune response with encapsulated MSCs. These results provide a new relevant step for the future clinical application of protein-coated GO on cell microencapsulation.

Characterization of Cement Particles Found in Peri-implantitis-Affected Human Biopsy Specimens

PURPOSE

Peri-implantitis is a disease characterized by soft tissue inflammation and continued loss of supporting bone, which can result in implant failure. Peri-implantitis is a multifactorial disease, and one of its triggering factors may be the presence of excess cement in the soft tissues surrounding an implant. This descriptive study evaluated the composition of foreign particles from 36 human biopsy specimens with 19 specimens selected for analysis. The biopsy specimens were obtained from soft tissues affected by peri-implantitis around cement-retained implant crowns and compared with the elemental composition of commercial luting cement.

MATERIALS AND METHODS

Nineteen biopsy specimens were chosen for the comparison, and five test cements (TempBond, Telio, Premier Implant Cement, Intermediate Restorative Material, and Relyx) were analyzed using scanning electron microscopy equipped with energy dispersive x-ray spectroscopy. This enabled the identification of the chemical composition of foreign particles embedded in the tissue specimens and the composition of the five cements. Statistical analysis was conducted using classification trees to pair the particles present in each specimen with the known cements.

RESULTS

The particles in each biopsy specimen could be associated with one of the commercial cements with a level of probability ranging between .79 and 1. TempBond particles were found in one biopsy specimen, Telio particles in seven, Premier Implant Cement particles in four, Relyx particles in four, and Intermediate Restorative Material particles in three.

CONCLUSION

Particles found in human soft tissue biopsy specimens around implants affected by peri-implant disease were associated with five commercially available dental cements.

USTUR whole body case 0262: 33-y follow-up of PuO2 in a skin wound and associated axillary node

This whole body donation case (USTUR Registrant) involved two suspected PuO2 inhalation intakes, each indicated by a measurable Pu alpha activity in a single urine sample, followed about 1(1/2) y later by a puncture wound to the thumb while working in a Pu glovebox. The study is concerned with modelling simultaneously the biokinetics of deposition and retention in the respiratory tract and at the wound site; and the biokinetics of Pu subsequently transferred to other body organs, until the donor's death. Urine samples taken after the wound incident had readily measurable Pu alpha activity over the next 14 y, before dropping below the minimum detectable excretion rate (<0.4 mBq d(-1)). The Registrant died about 33 y after the wound intake, at the age of 71, from hepatocellular carcinoma with extensive metastases. At autopsy, all major soft tissue organs were harvested for analysis of their 238Pu, 239+240Pu and 241Am content. The amount of 239+240Pu retained at the wound site was 68 +/- 7 Bq (1 SD), measured by low-energy planar Ge spectrometry. A further 56.0 +/- 1.2 Bq was retained in an associated axillary lymph node, measured by radiochemistry. Simultaneous mathematical analysis (modelling) of all in vivo urinary excretion data, together with the measured lung, thoracic lymph node, wound, axillary lymph node and systemic tissue contents at death, yielded estimated intake amounts of 757 and 1504 Bq, respectively, for the first and second inhalation incidents, and 204 Bq for the total wound intake. The inhaled Pu material was highly insoluble, with an estimated long-term absorption rate from the lungs of 2 x 10(-5) d(-1). The Pu material deposited at the wound site was mixed: approximately 14% was rapidly absorbed, approximately 49% was absorbed at the rate of about 6 x 10(-5) d(-1), and the remainder ( approximately 37%) was absorbed extremely slowly (at the rate of about 5 x 10(-6) d(-1)). Thus, it was estimated that only approximately 40% of the Pu initially deposited in the wound had been absorbed systemically over the 33-y period until the donor's death. The biokinetic modelling also indicated that, in this individual case, some of the parameter values (rate constants) incorporated in the ICRP Publication 67 Pu model were up to a factor of 2 different from ICRP's recommended values (for reference man).

Morphological findings and energy dispersive X-ray microanalysis of oral amalgam tattoos

Oral amalgam tattoos (AT) are distinct pigmentations of the oral mucosa resulting from accidental incorporation of dental amalgam in the oral soft tissues. Dental amalgams and in particular mercury, one of the constituents of dental amalgams, have for long been considered toxic. Oral ATs are easily accessible to study soft tissue reaction to amalgam and its degradation products. In this study, 17 oral ATs were examined by transmission electron microscopy and energy dispersive X-ray microanalysis. Ultrastructurally, in the ATs, three kinds of electron-dense particles were observed. The largest particles ranged in size from 0.5 up to several 100 microm. Smaller electron-dense inclusions (0.5-0.1 microm) were seen extracellularly associated with meshworks of elastic fibers and collagen bundles. The third and smallest type of particles (5-30 nm in diameter) was found with basement membranes of small vessels and pericytes and particularly decorating collagen bundles. Element analysis regularly revealed the presence of silver, sulphur, copper and lead in the AT decay products. Mercury was found in only one instance. Tissue reactions due to ATs seem to be minimal. No acute inflammatory changes were seen. Larger inclusions occasionally were surrounded by macrophages and multinucleated cells. TEM and element analysis may in specific cases be helpful in the differential diagnosis of pigmented lesions of the oral mucosa.

Consequence of body packing of illicit drugs

BACKGROUND

During the last decade, increased rates of drug traffic have led the smugglers to use various methods. One of these methods of illicit drug smuggling is body packing. Smuggling by intra-abdominal concealment is called "body packing". In this research, mortality rate was investigated due to body packing in Tehran.

METHODS

A descriptive study (case series) was designed on all corpses referred to the Forensic Medicine Organization of Tehran between April 1999 - December 2000. Demographic data such as sex, age, marital status, addiction, job, education level, type of opioid and the weight, number of packets, and results of blood and urine morphine tests by thin-layer chromatographic method were investigated.

RESULTS

Continental system of law is used in Iran and 0.06% of the referred corpses to Forensic Medicine Organization of Tehran were body packers. There were 12 cases, all of them were men. The mean age of body packers was 43 years (range 20 - 62). The minimum weight of the packets was 20 g and the maximum weight was 1400 g (mean = 501 g). The minimum number of the packets was one and the maximum number of the packets was 48. Twenty five percent of the corps were putrefied and one corpse was mummified. None of the body packers had academic education nor were employed. Nine of them lived in cities. Twenty five percent of them were intravenous addicts. The corpses were found mostly in terminals (17%), roads (58%), and cities (25%).

CONCLUSION

Hospital physicians may neglect this type of gastrointestinal foreign body if they are not aware of the body packer syndrome. Body packing should be suspected in anyone with signs of drug-induced toxic effects after a recent arrival on city terminals or when there is no history of recreational drug use.

Activated omentum becomes rich in factors that promote healing and tissue regeneration

In order to study the mechanism by which an omental pedicle promotes healing when applied to an injured site, we injected a foreign body into the abdominal cavity to activate the omentum. One week after the injection, we isolated the omentum and measured blood vessel density, blood content, growth and angiogenesis factors (VEGF and others), chemotactic factors (SDF-1 alpha), and progenitor cells (CXCR-4, WT-1). We found that the native omentum, which consisted mostly of adipose tissue, expanded the mass of its non-adipose part (milky spots) 15- to 20-fold. VEGF and other growth factors increased by two- to four-fold, blood vessel density by three-fold, and blood content by two-fold. The activated omentum also showed increases in SDF-1 alpha, CXCR-4, and WT-1 cells (factors and cells positively associated with tissue regeneration). Thus, we propose that an omentum activated by a foreign body (or by injury) greatly expands its milky-spot tissue and becomes rich in growth factors and progenitor cells that facilitate the healing and regeneration of injured tissue.

The influence of the foreign body response evoked by fibroblast transplantation on soluble factor diffusion in surrounding brain tissue

The transplantation of genetically engineered fibroblasts has been shown to be an effective approach for achieving continuous and site-specific delivery of therapeutic molecules to various regions of the central nervous system. However, to our knowledge no one has asked whether soluble factors released from the transplanted fibroblasts influence the delivery of therapeutic molecules from the engrafted cells. To address this issue, we used a newly developed cell encapsulation device to study the functional consequence of the foreign body response on soluble factor delivery from fibroblasts transplanted into adult brain tissue. We found that transplanted fibroblasts increased the level of inflammation and glial cell encapsulation at the transplantation site, and reduced the diffusion of a 70 kDa dextran probe through the reactive tissue. The response, however, did not prevent the diffusion of the 70 kDa dextran test probe indicating that the approach appears suitable for the delivery of neurotrophins and other therapeutic molecules with a molecular weight less than 70 kDa. The results suggest that less reactive cell types may be better suited for sustained delivery of therapeutic molecules into brain tissue.

Percutaneous penetration of uranium in rats after a contamination on intact or wounded skin

The aim of this work is to assess in vivo in a hairless rat model, the percutaneous diffusion of uranium through intact or wounded rat skin. Six types of wounds were simulated by excoriation and burns with 10 N HF, 2, 5 and 14 N HNO3 and 10 N NaOH on anaesthetised hairless rats. Percutaneous penetration through wounded skin towards blood and subsequent urinary excretion of uranium was followed in vivo during 24 h. The influence of the physicochemical form (solution or powder) of uranyl nitrate (UN) on its percutaneous diffusion was also investigated. UN, even as a powder, can diffuse through intact skin. The presence of uranium in blood is more persistent and its urinary elimination is slower after an HF burn than after an HNO3 burn. Excoriation increases dramatically percutaneous absorption of UN. Thus, percutaneous diffusion of UN is largely dependent on skin barrier integrity with a particular importance of stratum corneum.

Beyond foreign-body-induced carcinogenesis: Impact of reactive oxygen species derived from inflammatory cells in tumorigenic conversion and tumor progression

Foreign-body-induced carcinogenesis is a traditional, maybe old, way of understanding cancer development. A number of novel approaches are available today to elucidate cancer development. However, there are things we learn from the old, and thus I bring out some examples of various clinical cases and experimental models of foreign-body-induced tumorigenesis. What is notable is that the foreign bodies themselves are unrelated to each other, whereas commonly underlying in them is to induce inflammatory reaction, especially stromal proliferation, where those exogenous materials are incorporated and undigested. Such foreign-body-induced carcinogenesis is also recognized in the step of tumor progression, the final step of carcinogenesis that tumor cells acquire malignant phenotypes including metastatic properties. And the phenomenon is universally observed in several cell lines of different origins. In this review I would like to show the evidence that tumor development and progression are accelerated inevitably by inflammation caused from foreign bodies, and that reactive oxygen species derived from inflammatory cells are one of the most important genotoxic mediators to accelerate the process.

Modelling of bioassay data from a Pu wound treated by repeated DTPA perfusions: biokinetics and dosimetric approaches

The aim of this study is to model plutonium (Pu) excretion from the analysis of a well-documented Pu wound case involving repeated diethylene-triamine-penta-acetic acid (DTPA) perfusions up to 390 d and monitoring up to 3109 d. Three modelling approaches were simultaneously applied involving: (1) release of soluble Pu from the wound, estimated with the ICRP66 dissolution model, (2) systemic behaviour of Pu by using ICRP67 model, but also two new models recently reported and (3) additional 'Pu-DTPA' compartments which transfer Pu directly to urinary compartment from blood, interstitial fluids and liver. The best fit of simulations to biological data was obtained by using the new Leggett's systemic model and assuming the presence of three DTPA compartments. Calculations have shown that DTPA treatments have contributed to a 3-fold reduction of the effective dose. Thus, reduction of doses associated with the DTPA treatments can be estimated by modelling which is useful to improve the efficacy of a DTPA treatment schedule based on a diminution of risk.

Oxidative and nitrative stress caused by subcutaneous implantation of a foreign body accelerates sarcoma development in Trp53+/- mice

Chronic inflammation is a recognized risk factor for human cancer at various sites because of persistent oxidative and nitrative tissue damage. Trp53+/- mice show the predisposition to tumor development, such as sarcomas and lymphomas, compared with Trp53+/+ mice. We investigated the effects of chronic inflammation, especially oxidative and nitrative stress, induced by subcutaneous implantation of a plastic plate (10 x 5 x 1 mm) as a foreign body on tumorigenesis in Trp53+/- and Trp53+/+ mice. The plastic plates were implanted at the age of about 11 weeks. Thirty out of 38 Trp53+/- mice (79%) developed sarcomas around the implant (mean time of tumor appearance was 45.8 +/- 12.0 weeks of age), whereas only one of 10 Trp53+/+ mice with an implant (10%) developed a tumor, at 56 weeks. No sarcomas developed at a sham-operation site. Two of 10 Trp53+/- mice with no implant (20%) also developed three sarcomas spontaneously at 77, 81 and 84 weeks. Increased immunostaining for markers of oxidative and nitrative stress (8-oxo-7,8-dihydro-2'-deoxyguanosine, 8-nitroguanine and 3-nitrotyrosine) and expression of inducible nitric oxide synthase in tumor cells and inflammatory cells were detected in implant-induced sarcomas compared with spontaneous sarcomas in Trp53+/- mice. Furthermore, p53 loss of heterozygosity was observed in 26 out of 29 implant-induced sarcomas (90%). These results indicate that implanted foreign bodies significantly enhanced sarcoma development in Trp53+/- mice, and this may be associated with increased oxidaive and nitrative stress. Loss of the remaining wild-type p53 allele and loss of p53 function appears to be, at least in part, underlying molecular mechanisms during the development of sarcomas at the implantation site in Trp53+/- mice. Such implant-induced sarcoma development in Trp53+/- mice could be useful for studying molecular mechanisms and developing new strategies for chemoprevention in human carcinogenesis induced by chronic inflammation and/or foreign bodies.

Fatal heroin intoxication in body packers in northern Thailand during the last decade: two case reports

A body packer is an important means of drug trafficking. While drug packets are inside the body, they can leak or rupture causing acute substance toxicity. Most of the reports of body packer syndrome have come from Europe and North America, which are destination targets. In the present study, the authors reported two cases of fatal heroin body packers from the northern part of Thailand. Both cases were foreign tourists who came to Chiang Mai and stayed in a hotel or a guesthouse room in which the deaths occurred. The autopsy findings revealed rupturing of heroin packages in the stomach. The packaging used in both cases was not sophisticated. The powder was packed inside condoms without extra covering, as observed in some other professional packers. The amount of heroin transported was about 30-50 gm. The purity of heroin in this powder was about 50-90%. Their destinations were their home countries and not directly to Europe or North America. Deaths occurred just prior to their return. The cause of death was a heroin overdose. A significant level of heroin metabolites, 6-MAM and morphine were detected in the blood and urine.

Toxicity of uranium and the removal effects of CBMIDA and EHBP in simulated wounds of rats

We examined the acute toxicity of uranium (99.3% 238U, 0.7% 235U) and the effects of Catechol-3,6-bis(methyleiminodiacetic acid) (CBMIDA) and Ethane-1-hydroxy-1,1-bisphosphonate (EHBP) on the removal of uranium after intramuscular injection as a simulated wound intake in rats. In this experiment, male Wistar rats, 8 wk old, were injected intramuscularly with uranyl nitrate in the femoral muscles. Experiment I: Rats died from 3 to 7 d after they were injected with five doses of 7.9, 15.8, 31.5, 63, and 126 mg kg(-1) uranium. The uranium retained 8.4-13.6% of the injected doses in the kidneys, showing the relationship between the injected dose and the retained concentration (r = 0.997). The excretion rates of the injected doses in the 63 and 126 mg kg(-1) uranium-injected rats were 1.73% and 3.09% in urine and 0.81% and 1.06% in feces on the first day, and 0.54% and 0.56% in feces on the second day, respectively. Experiment II: The retention of uranium at 1, 3, 6, and 24 h was examined after rats were injected with 63 mg kg(-1) uranium. The concentration of uranium decreased in the plasma, while it increased in the kidneys and femur until 6 h, and it continued to increase in the liver until 24 h. Experiment III: Rats were divided into four groups (n = 10) and were injected with a dose of 2 mg kg(-1) uranium. Two of the groups were then injected intraperitoneally with 240 or 480 mg kg-1 CBMIDA, and one group was injected with 10 mg kg(-1) EHBP once daily for 28 d, beginning 1 h after uranium injection on the first day. The fourth group was the non-treated control group. The survival rates at the end of the experiment were 80% and 40% in the 240 and 480 mg kg(-1) CBMIDA groups, 50% in the EHBP group, and 20% in the non-treated group. The successive administration of chelating agents was effective in decreasing the concentration of uranium in the kidneys, bone, and liver. The results indicated that uranium induces acute death and renal dysfunction by chemical toxicity, and both CBMIDA and EHBP were effective agents to prevent these effects.

Effects of gastric acid on euro coins: chemical reaction and radiographic appearance after ingestion by infants and children

OBJECTIVES

This study investigated whether coins of the new European currency (euro) corrode when they are exposed to gastric acid, and whether this change can be detected radiographically.

METHODS

The eight different denominations of coins were immersed for seven days in 0.15 N hydrochloride acid (HCl), which corresponds to the level of post-prandial gastric acid. A Swedish crown coin and three different Austrian schilling coins were used as controls. The coins were weighed and radiographed daily to evaluate visible corrosions and HCl was analysed daily for possible dissolved substances.

RESULTS

All coins lost weight within 24 hours after exposure to HCl. The 1, 2, and 5 euro cent coins developed changes that were visible on radiographs. The weights of all coins decreased by 0.43% to 11.30% during one week. The dissolved substances measured in the HCl corresponded to the different metals and alloys of the coins, except for copper, which does not dissolve in HCl. The highest absolute weight loss was observed in the Swedish crown coin (0.67 g), and the highest relative weight loss in the 1 Austrian schilling coin (11.30%). The two coins that showed the highest absolute and relative weight losses were the 2 euro (0.54 g or 6.35%) and the 1 euro (0.48 g or 6.39%) coin.

CONCLUSIONS

A higher rate of toxicity for the new European coins compared with coins of other currencies is not expected, unless a massive coin ingestion occurs.

The influence of molecular weight, crosslinking and counterface roughness on TNF-alpha production by macrophages in response to ultra high molecular weight polyethylene particles

The response of murine macrophages to clinically relevant polyethylene wear particles generated from different polyethylenes at various time points and volumetric doses in vitro was evaluated. Clinically relevant ultra high molecular weight polyethylene (UHMWPE) wear debris was generated in vitro in a lubricant of RPMI 1640 supplemented with 25% (v/v) foetal calf serum using a multi-directional pin-on-plate wear rig under sterile conditions. Wear debris was cultured with C3H murine peritoneal macrophages at various particle volume (microm(3)): cell number ratios. The secretion of TNF-alpha was determined by ELISA. Initially the effect of molecular weight of UHMWPE was considered. Higher molecular weight GUR415HP was shown to have a lower wear rate than the lower molecular weight GUR1120, however a greater volume of the wear debris produced by the high molecular weight GUR415HP was in the 0.1-1.0 microm size range. Wear debris from GUR415HP produced significant levels of TNF-alpha at a concentration of 1 microm(3)/cell while at least 10 microm(3)/cell of GUR1120 wear debris per cell was needed to produce significant levels of TNF-alpha. Secondly the effects of crosslinking GUR1050 was examined when worn against a scratched counterface. The wear rate of the material was shown to decrease as the level of crosslinking increased. However the materials crosslinked with 5 and 10 Mrad of gamma irradiation produced higher percentages of 0.1-1.0 microm size wear particles than the non-crosslinked material. While the crosslinked material was able to stimulate cells to produce significantly elevated TNF-alpha levels at a particle concentration of just 0.1 microm(3)/cell only concentrations of 10 microm(3)/cell and above of the non-crosslinked wear debris were stimulatory. When the counterface was changed from scratched to smooth the wear rate for all three GUR1050 materials was further reduced. For the first time nanometre size wear particles were observed from polyethylene which reduced the percentage mass of debris in the 0.1-1.0 microm size range. For all three materials on the smooth counterface only concentrations of 50 microm(3)/cell and above were stimulatory. This study has demonstrated that molecular weight, crosslinking and counterface roughness are important factors in determining the biological activity of polyethylene.

Accumulation of aluminium in lamellar bone after implantation of titanium plates, Ti-6Al-4V screws, hydroxyapatite granules

Titanium plates, Ti6Al4V screws and surrounding tissues, and biopsies of hydroxyapatite (Osprovit) grafts of maxillary sinus lifting were investigated to evaluate the release and accumulation of ions. Optical microscopy, SEM and X-ray microanalysis were carried out to evaluate the plates and screws removed from patients presenting inflammation and biopsies. Ions release from metallic appliances or leaching from granules towards soft tissues was observed. An accumulation of aluminium but not titanium was found in soft tissues. A peculiar accumulation of aluminium in the dense lamella of newly formed bone was recorded. The results seem to indicate that biological perturbations may be related to aluminium release from the tested biomaterials. The aluminium content of these biomaterials, its diffusion and accumulation are discussed. Further studies on ion release from biomaterials and aluminium fate in skeletal tissues are suggested.

Investigation of the activation of a human serum complement protein, C3, by orthopedic prosthetic particulates

Myriad molecular, cellular, and physiological processes underlie the inflammatory and osteolytic processes induced by particles of biomaterials resulting from the wear of implants such as total joint replacement prostheses. The objective this study was to investigate the role that the complement system may be playing in these phenomena. The aim was to evaluate the degree to which particles of selected orthopaedic materials--high density and ultrahigh molecular weight polyethylene, polymethylmethacrylate, and commercially pure titanium--cause the elevation of a key complement molecule, C3a, in an in vitro assay that directly measured the concentration of C3a. The results demonstrated that HDPE particles, at high concentration, are capable of causing the elevation of C3a in the in vitro assay. This finding is discussed in the context of other work and the mechanics of the complement system as it may affect the osteolytic process.

The influence of alumina and ultra-high molecular weight polyethylene particles on osteoblast–osteoclast cooperation

Particle-induced macrophage activation, mainly by UHMWPE wear, has been recognized as the biological mechanism leading to periprosthetic bone resorption, which is responsible for the loosening of the total hip replacements (THR). Ceramic-on-ceramic implants have been advocated as a means of reducing wear products. Many studies investigated the effect of alumina (Al(2)O(3)) particles on monocytes/macrophages, but only limited information are available on their participation to bone turnover. An in vitro model was performed to investigate how Al(2)O(3) and UHMWPE particles may influence the osteoblast-osteoclast interaction: human osteoblasts (HOB) were obtained from trabecular bone, while osteoclasts were derived from peripheral blood mononuclear cells (PBMC) of healthy donors. The amount of IL6, TNF alpha, GM-CSF, and other factors acting on the bone turnover, i.e. the 'receptor activator of NF kappa B' ligand (RANKL) and osteoprotegerin (OPG), was detected in culture medium of particle-challenged HOB (HOB-CM). The Al(2)O(3) and UHMWPE particles did not affect either cell viability or TNF and GM-CSF release, while the increase in IL6 release seemed to be dependent on the particle concentration. UHMWPE increased the release of RANKL from HOB, while OPG and OPG-to-RANKL ratio were significantly inhibited. The ability of HOB-CM to promote osteoclastogenesis was tested via osteoblast/monocyte cooperation: after seven days of culture UHMWPE HOB-CM induced a large amount of multinucleated TRAP-positive giant cells, as well as significantly reduced the amount of IL6, GM-CSF and RANKL in the supernatant. With regard to the inductive effect on the osteoclastogenesis, our results show that the Al(2)O(3) wear debris are less active.

Metal degradation products: a cause for concern in metal-metal bearings?

In the majority of patients, orthopaedic implants are biocompatible. However, there is an increasing recognition that, in the long-term, permanent orthopaedic implants may be associated with adverse local and remote tissue responses in some individuals. These adverse effects are mediated by the degradation products of implant materials. The recent reintroduction of metal-on-metal bearings for total hip arthroplasty has heightened concerns about the biologic response to metal degradation products in light of the fact that the serum and urine metal concentrations in patients with these implants typically are higher than those seen in patients with conventional metal-on-polyethylene bearings. From previous studies of long-term metal-on-metal McKee-Farrar implants, it seems that these elevated levels may persist for the duration of the implant's lifetime. This is of particular concern in the younger and more active patient in whom life expectancy after implantation may exceed 30 years. The association of metal release from orthopaedic implants with any metabolic, bacteriologic, immunologic, or carcinogenic toxicity currently remains conjectural because cause and effect have not been established in human subjects. However, continued surveillance of patient populations with metal implants, particularly those with metal-metal bearings, is warranted.

Semi-quantitative analysis of cytokines in MM THR tissues and their relationship to metal particles

Cytokines associated with osteolysis have been demonstrated in tissues surrounding failed metal-metal (MM) total hip replacements (THRs). The objective of the present study was to semi-quantify the amounts of inflammatory cytokines in tissues from 28 failed MM THRs, and determine their relationship with the quantity of metal particles. Paraffin sections were immunohistochemically stained with monoclonal antibodies: anti-IL-1-beta, anti-IL-6 and anti-TNF-alpha. Cytokines and metal particles were rated in 10 fields per tissue using standard light microscopy. Because of the use of light microscopy, only relatively large particles or agglomerations of particles were visible. Therefore, a polarized light and a semi-quantitative scheme based on the discoloration of cell cytoplasms induced by the presence of particles were used to evaluate the quantity of metal particles. Results showed an overall higher amount of IL-6 than IL-1beta while TNF-alpha remained at very low levels. For each patient, the average IL-1beta and IL-6 ratings decreased when the average particle rating increased, following a linear regression, with relatively high correlation factors (r=-0.69 for IL-1beta and r=-0.57 for IL-6). IL-1beta decreased about twice as fast as IL-6. TNF-alpha, remaining at very low levels, did not demonstrate any correlation with particle rating. When multiple tissues were available for the same patient, the correlation factors between the average cytokine and particle ratings were highly variable between samples, demonstrating the heterogeneity between the tissues from the same patient. At the cellular level, there was an even higher correlation between the quantity of metal particles and the production of IL-1beta and IL-6 (r=-0.99), while TNF-alpha did not demonstrate any correlation, remaining at very low levels. In conclusion, this study showed that tissues surrounding failed MM THRs with low to moderate quantities of metal particles can induce the production of potentially osteolytic cytokines. However, the overall number of cells producing these cytokines tended to be lower than that typically seen in tissues surrounding metal-polyethylene THRs.

The biological reaction to polyethylene wear debris can be related with oxidation of the UHMWPE cups

BACKGROUND

Oxidised UHMWPE due to gamma irradiation in air has a greater susceptibility to wear than non-oxidised UHMWPE (ethylene oxide, EtO).

AIM

To evaluate, the biological reaction of loose implants with oxidised and non-oxidised PE components.

MATERIALS AND METHODS

Ten loose PE cups sterilised by EtO (group 1) and 13 sterilised by gamma irradiation in air (group 2) were studied. PE wear and oxidation were related to biological reaction.

RESULTS

Group 1: PE cups had low wear score and no oxidation. In the oldest implants, a few PE particles and macrophages were observed in the interface membrane. Group 2: PE inserts had medium-to-high PE wear score and variable oxidation. In the interface membrane, the number and total area of PE particles were high and variable; giant cells were more numerous than macrophages.

CONCLUSION

Junctional tissues around loose oxidised PE components contain more PE debris and giant cells than membranes around PE components that are not oxidised.

Effect of reactive cell density on net [2-14C]acetate uptake into rat brain: labeling of clusters containing GFAP+- and lectin+-immunoreactive cells

Astrocytic proliferation is a hallmark of brain injury, but the biological functions and metabolic activities of reactive astrocytes in vivo are poorly understood. [2-14C]Acetate, which is preferentially transported into and, therefore, metabolized by astrocytes, was used to assess injury- and trophic factor-induced changes in astrocyte metabolic activity. Local rates of net [2-14C]acetate uptake and glucose utilization (CMR(glc)), determined with [14C]deoxyglucose to assay overall metabolic activity of all brain cells, were assayed 7 days after a cannula placement; adjacent brain sections were immunostained to identify glial fibrillary acidic protein-positive (GFAP(+)) astrocytes and microglia plus macrophages (lectin-positive cells). GFAP(+) cells were abundant in tissue surrounding the cannula compared to the contralateral hemisphere, whereas lectin(+) cells were restricted to the wound boundary. CMR(glc) fell 25% in regions enriched in reactive astrocytes compared to the homologous contralateral hemisphere, whereas [14C]acetate uptake increased slightly (6%) but statistically significantly; metabolism of both tracers in 13 other brain structures was unchanged. Injection of basic fibroblast growth factor (b-FGF) into cerebral cortex or superior colliculus produced fiber-rich cell clusters containing both GFAP(+) and lectin(+) cells that had a 37% increase in [14C]acetate uptake; GFAP(+)-cell density rose in the nearby neuropil but the corresponding change in [14C]acetate uptake was small (6-8%). Sensory stimulation did not alter [14C]acetate uptake into the clusters. Thus, [14C]acetate uptake was relatively stable with respect to changes in the density of reactive astrocytes that are dispersed throughout the neuropil and to changes in cellular activity arising from sensory stimulation. In contrast, b-FGF-induced cell clusters that contain mixed cell types and numerous fibers accumulated higher levels of [14C]acetate, raising the possibility that increased uptake might be due to high numbers of activated astrocytes and, perhaps, acetate metabolism by other cell types.

Practical system to detect and assess consequences of radioactivity in a wound

Any wound received within the controlled areas of Dounreay could potentially be contaminated with plutonium and/or uranium isotopes. Wounding bypasses the body's natural barriers to foreign objects, such as the skin and the lining of the alimentary canal. Therefore a relatively low intake can potentially result in a high committed effective dose. The likelihood of contamination of a wound with either plutonium or uranium is low. The decision-making process for dealing with wounds has been continually reviewed and updated by the approved dosimetry service (ADS) at Dounreay. Each wound is considered on an individual basis by the ADS in order to decide what follow-up actions, if any, are necessary. The aim of the process is to maximise the probability that a significant intake is detected, while targeting resources in an appropriate manner.

A case of rhinolithiasis in botswana: a mineralogical, microscopic and chemical study

A case of rhinolithiasis in Southeast Botswana was treated and after removal in hospital, the rhinolith was subjected to macroscopic and microscopic examination, X-ray diffraction analysis, electron microscope analysis and partial botanical analysis. The rhinolith consists of a strongly elliptical core of calcium stearate (C36H70CaO4.H2O), surrounded by approximately 30 elongated concentric growth rings, consisting of sodium-containing whitlockite (Ca18Mg2(Na,H)(PO4)14). The different layers have various degrees of porosity and red staining, probably due to traces of amorphous iron oxide. The origin of the rhinolith started with a piece of plant material, lodged in the nose, which was replaced by calcium stearate, leaving some remnants of resistant epidermal plant tissue. During subsequent years, thin layers of whitlockite were deposited periodically around the core with the reddish brown bands representing deposition during the dry season when atmospheric dust rich in amorphous iron oxide is at its highest in Botswana.

Cutaneous angiosarcoma arising in a gouty tophus: report of a unique case and a review of foreign material-associated angiosarcomas

Rare cases of angiosarcoma have been reported to arise in the setting of retained foreign material or in association with arteriovenous fistulae. No previous case of angiosarcoma, or any other malignancy, has been reported to arise with a gouty tophus. We present a case of an 86-year-old man with a high-grade angiosarcoma that arose within a long-standing tophus.

Pathological mineralizations: calcifications and Si-bearing particles in soft tissues and their eventual relationship to different prostheses

Polarizing microscopy (PM), scanning electron microscopy (SEM), x-ray dispersive analysis (EDAX), x-ray diffraction (XRD), and infrared spectrometry (IR) were used to study the following pathological mineralizations: calcifications and silicon(Si)-bearing mineralizations in cerebral tissue from an epileptic child; traces of Si-bearing particles in periprosthesic mammarian tissue, and calcifications in capsular mammarian tissue from a patient with a silicone gel mammarian implant, and 2 calcium-bearing compounds, a typical apatitic calcification, and a nonphosphorous-bearing calcification in arterial tissues. In this tissue we also found Si-bearing particles due to an artifact from glassware.

[Effection of children airway foreign bodies on blood acid-base disturbances]

OBJECTIVE

To explore the effects of children airway foreign bodies on blood acid-base disturbances.

METHOD

To detect the blood-gas and electrolyte of 50 cases by children airway foreign bodies (test group), they were compared with 50 cases normal children (control group). To calculate anion gap (AG), to determine types of acidbase disturbances.

RESULT

The blood-gas and K+ were significant difference between that two groups. In the test group, there were 25 simple and 19 mixed acid-base disturbances; 6 acid-base balances. There were 31 high AG, 18 normal AG, one low AG.

CONCLUSION

Children airway foreign bodies can cause acid-base disturbances. It was major in simple metabolic acidosis and mixed metabolic acidosis with respiratory alkalosis, it was more in high AG-metabobic acidosis.

Metal debris from titanium spinal implants

STUDY DESIGN

A prospective study of tissue surrounding spinal instrumentation was performed using histologic and chemical analysis.

OBJECTIVES

To identify and quantify the amount of metal debris generated by titanium pedicle screw instrumentation and to evaluate the histologic response in the spinal tissues.

SUMMARY OF BACKGROUND DATA

Microscopic metal particles from the soft tissue surrounding joint arthroplasties have been shown to activate a macrophage response that leads to bone resorption and increased inflammation. The use of titanium spinal implants for spine surgery projects the possibility of generating wear debris in the spine.

METHODS

Nine patients with titanium instrumentation from a prior lumbar decompression and fusion procedure who were undergoing reoperation were entered into this study. Tissue samples were collected from areas near the pedicle screw-rod junction, the scar tissue overlying the dura, and the pedicle screw holes. Metal levels for titanium were determined by electrothermal atomic absorption spectroscopy, and histologic analysis was performed by light and electron microscopy.

RESULTS

Tissue concentrations of titanium were highest in patients with a pseudarthrosis (30.36 micrograms/g of dry tissue). Patients with a solid fusion had low concentrations of titanium (0.586 microgram/g of dry tissue). Standard light microscopy identified metal particles in the soft tissues. Transmission electron microscopy demonstrated macrophages with numerous secondary lysosomes containing electron-dense bodies and collagenous stroma with electron-dense rod-like profiles consistent with metal debris.

CONCLUSIONS

Wear debris is generated by the use of titanium spinal instrumentation in patients with a pseudarthrosis. These particles activate a macrophage cellular response in the spinal tissues similar to that seen in surrounding joint prostheses. Patients with a solid spinal fusion have negligible levels of particulate matter.

Silicone deposition in reconstruction scars of women with silicone breast implants

BACKGROUND

The possible association of silicone breast implants and disease is a subject of continuous debate and concern.

OBJECTIVE

Our purpose was to examine microscopically and ultrastructurally the periprosthetic fibrous capsules and reconstruction scars of women with silicone breast implants.

METHODS

Representative samples from the periprosthetic capsules and reconstruction scars from six women with silicone breast implants were examined by a variety of light microscopy techniques, transmission electron microscopy, and electron probe microanalysis.

RESULTS

Silicone globules of various sizes were identified in every periprosthetic capsule and reconstruction scar.

CONCLUSION

Extrusion and seeding of the incision tract during surgery most likely accounts for the presence of silicone in the reconstruction scar specimens. This observation suggests that the identification of silicone in the reconstruction scars of women with silicone breast implants does not necessarily implicate rupture of the silicone breast implant with systemic dissemination of silicone gel.

The expression of osteoclast markers on foreign body giant cells

The expression of some candidate osteoclast markers, tartrate-resistant acid phosphatase (TRAP), macrophage associated antigens (M phi Ag), and vitronectin receptor (VNR) on foreign body giant cells (FBGCs) was investigated in peri-implant tissues of loosened total joint arthroplasties. Osteoclasts showed distinct staining characteristics. They were strongly TRAP-positive at tartrate concentrations of 50-200 mM and expressed VNR and a restricted range of M phi Ag. In contrast, FBGCs were shown to be significantly heterogeneous. Significant numbers of FBGCs were TRAP-positive at a 100 mM tartrate concentration and some were more intense than osteoclasts. A population of FBGCs did not express M phi Ag such as CD11b, but expressed VNR. It was demonstrated that these candidate osteoclast markers were also positive on FBGCs. These results have highlighted the difficulty in distinguishing these two cell lineages and suggested that there might be some uncertainty in defining osteoclast-like cells in culture studies.

Angiosarcoma of the colon developing in a capsule of a foreign body. Report of a case with associated hemorrhagic diathesis

A case of angiosarcoma of the colon is reported. The tumor developed in the fibrous capsule of a retained sponge that was lost 25 years earlier during a gynecologic surgical procedure. The postoperative course was dominated by a fatal consumptive thrombohemorrhagic disorder. Angiosarcoma associated with a retained foreign body and development of hemorrhagic diathesis in angiosarcoma are discussed.

An unusual skin exposure to copper; clinical and pharmacokinetic evaluation

Skin exposure to copper is rare and has been described only with copper sulfate. A case of skin exposure to copper after an explosion of copper azide is presented. The amount of copper absorbed by this route was estimated to be 7.7 mg. Calculated distribution volume was 2.02 I/kg, half-life was 167.4 days and clearance was 0.0058 ml/min/kg. The authors also demonstrated metallic copper to be radiopaque, in contrast to copper salts. It is suggested that copper may be absorbed from the skin even if it is in the metal form. Careful clinical follow up as well as serial determinations of serum copper should guide the need for chelation therapy.

The use of elemental microanalysis in verification of the composition of presumptive amalgam tattoo

Routine histochemistry, special stains, and energy dispersive x-ray microanalysis (EDX) were used to analyze 15 cases of presumptive amalgam tattoo. Histologically, the fine, spherical, golden brown granules of amalgam were remarkably similar to hemosiderin and melanin granules, and routine and special stains were not always reliable in differentiating one from the others. EDX provided a simple, fast, inexpensive, and reliable method for identifying the precise elemental composition of the pigmented material.

[Rhinolithiasis--with special reference to minerology]

A rhinolith present for 77 years and weighing 18 g. is reported. Special emphasis is given to the problems of establishing the diagnosis of nasal calculi and foreign bodies. Furthermore, the study discusses the mineralogy of the rhinolith on the basis of the results yielded by the electron-ray micro-probe, x-ray diffractometry and infrared-spectroscopy with respect to the mineral Whitlockite.

Enzymic modification of environmental intoxicants: the role of cytochrome P-450

As of November 1977, the American Chemical Society's Chemical Abstracts Service computer registry of chemicals contained 4039907 distinct entities, and has been growing at an average rate of about 6000 per week. How many of these chemicals are in everyday use? Current estimates from the Environmental Protection Agency indicate that there may be as many as 50000 commonly used chemicals, not including pesticides, pharmaceuticals, and food additives. The EPA estimates that there may be as many as 1500 different active ingredients in pesticides. The Food and Drug Administration estimates that there are about 4000 active ingredients in drugs and about 2000 other ancillary compounds used in the drug industry. The FDA also estimates that there are about 2500 additives used for nutritional value and flavouring and 3000 chemicals used to preserve processed food. Thus there seem to be about 63000 chemicals in common use.

Pulmonary excretion of foreign bodies and necrotic material from the bladder wall

Following injection of carbon suspension into the bladder wall of white rats, carbon particles were observed in the cytoplasm of cells located as the alveolar macrophages. Following injections of a solution of AgNO3 into the bladder wall of white rats, dark stained spots were observed in the cytoplasm of cells located as the alveolar macrophages. It is suggested that pulmonary excretion of carbon particles and silver stained necrotic material from the bladder wall takes place. These results may contribute to the problems involved by pulmonary changes observed in the X-irradiated patients with carcinoma of the bladder.