Matrix therapy in regenerative medicine, a new approach to chronic wound healing

Nonhealing wounds remain a major health problem whose treatment is challenging and costly. Treatments based on cells or growth factors are still not very effective. We developed an entirely novel strategy consisting in treatment of the wound-tissue matrix with biopolymers engineered to mimic heparan sulfates called OTR4120. This compound was dextran polymer with sulfated and carboxymethyl groupments. After binding to matrix proteins, the heparan-sulfate-mimicking polymer protects the microenvironment, maintaining the normal production of signals and growth factors needed for healing to occur. Here, we show that a specific biopolymer accelerates ulcer closure and improves re-epithelialization and dermal-matrix-component remodeling. OTR4120 treatment was associated with faster maturation of epidermal structures, most notably regarding the number of epithelial-cell layers, and with an appearance that more closely resembled normal skin. Treatment had also a main effect on collagen I and III expression. Necrotic skin ulcers induced in mice with doxorubicin recovered normal collagen levels and organization, with no evidence of fibrosis. Thus, appropriate polymer-based matrix therapy is a valid and simple alternative to regenerative medicine.

Banding pattern indicative of echinococcosis in a commercial cysticercosis Western blot

Objective

A commercial cysticercosis Western blot was evaluated for serological cross-reactivity of sera from patients with alveolar (AE) and cystic echinococcosis (CE).

Methods

A total of 161 sera were examined, including 31 sera from AE-patients, 11 sera from CE-patients, 9 sera from patients with other parasitic diseases and 109 sera from patients with unrelated medical conditions. All AE-and CE-sera were also examined by the echinococcosis Western blot.

Results

More sera from patients with AE than with CE showed cross-reactivity in the form of ladder-like patterns ("Mikado aspect") and untypical bands at 6-8 kDa (71% and 77.4% versus 27.3% and 45.5%, respectively). In contrast, triplets of bands in the area above 50 kDa and between 24 and 39-42 kDa were more frequent in CE than in AE sera. The fuzzy band at 50-55 kDa typical for cysticercosis was absent in all AE and CE sera.

Conclusions

Atypical banding patterns in the cysticercosis Western blot should raise the suspicion of a metacestode infection different from Taenia solium, i.e. Echinococcus multilocularis or E. granulosus, especially when the Mikado aspect and an altered 6-8 kDa band is visible in the absence of a fuzzy 50-55 kDa band.

Potency values from the local lymph node assay: application to classification, labelling and risk assessment

Hundreds of chemicals are contact allergens but there remains a need to identify and characterise accurately skin sensitising hazards. The purpose of this review was fourfold. First, when using the local lymph node assay (LLNA), consider whether an exposure concentration (EC3 value) lower than 100% can be defined and used as a threshold criterion for classification and labelling. Second, is there any reason to revise the recommendation of a previous ECETOC Task Force regarding specific EC3 values used for sub-categorisation of substances based upon potency? Third, what recommendations can be made regarding classification and labelling of preparations under GHS? Finally, consider how to integrate LLNA data into risk assessment and provide a rationale for using concentration responses and corresponding no-effect concentrations. Although skin sensitising chemicals having high EC3 values may represent only relatively low risks to humans, it is not possible currently to define an EC3 value below 100% that would serve as an appropriate threshold for classification and labelling. The conclusion drawn from reviewing the use of distinct categories for characterising contact allergens was that the most appropriate, science-based classification of contact allergens according to potency is one in which four sub-categories are identified: 'extreme', 'strong', 'moderate' and 'weak'. Since draining lymph node cell proliferation is related causally and quantitatively to potency, LLNA EC3 values are recommended for determination of a no expected sensitisation induction level that represents the first step in quantitative risk assessment.

Autochthonous cystic echinococcosis in patients who grew up in Germany

Human cystic echinococcosis (CE) is a widespread zoonosis. Cases occurring in Germany are considered to result from imported infection and it is unclear if Echinococcus granulosus (sensu lato) is still transmitted in Germany. Therefore, exposure was investigated in 15 patients with cystic echinococcosis (7 female, 8 male; age-range 16-68, with a median of 48 years) who grew up in Germany. Fourteen patients had most likely acquired their infection in rural Germany, 11 from local dogs, one from an imported dog, two without obvious dog contacts. Taking into account multiple conceivable confounding factors might also account for some of infections: contacts with imported dogs or contact with dogs during travel in highly endemic regions, and ingestion of food contaminated by worm ova, whether in Germany or abroad. However, in at least two cases autochthonous transmission is beyond doubt, because these patients had never left Germany. The long pre-symptomatic development of cystic echinococcosis does not allow for a precise evaluation of the actual epidemiological situation. Compulsory notification of human cystic echinococcosis is an important instrument in the surveillance of the disease in humans. Regular inquiries at laboratories carrying out work in the field of veterinary medicine and at slaughterhouses, supervision of dogs at risk as well as genetic investigations on the strain or species of the causal agent of cystic echinococcosis are needed.

[Study protocol of the VISEP study. Response of the SepNet study group]

In the commentary by Zander et al. the authors appear concerned about the methods and results of our, at that time, unpublished sepsis trial evaluating hydroxyethyl starch (HES) and insulin therapy. Unfortunately, the authors' concerns are based on false assumptions about the design, conduct and modes of action of the compounds under investigation. For instance, in our study the HES solution was not used for maintenance of daily fluid requirements, so that the assumption of the authors that this colloid was used "exclusively" is wrong. Moreover, the manufacturer of Hemohes, the HES product we used, gives no cut-off value for creatinine, thus the assumption that this cut-off value was "doubled" in our study is also incorrect. Other claims by the authors such as that lactated solutions cause elevated lactate levels, iatrogenic hyperglycemia and increase O(2) consumption are unfounded. There is no randomized controlled trial supporting such a claim - this claim is neither consistent with our study data nor with any credible published sepsis guidelines or with routine practice worldwide. We fully support open scientific debate. Our study methods and results have now been published after a strict peer-reviewing process and this data is now open to critical and constructive reviewing. However, in our opinion this premature action based on wrong assumptions and containing comments by representatives of pharmaceutical companies does not contribute to a serious, unbiased scientific discourse.

Long-term follow-up of metabolic activity in human alveolar echinococcosis using FDG-PET

AIM

[(18)F]fluoro-deoxyglucose positron-emission-tomography (FDG-PET) detects metabolic activity in alveolar echinococcosis (AE). The slow changes in metabolic and morphological characteristics require long-term follow-up of patients. This is the first study to evaluate metabolic activity over may years, hereby assessing the utility of FDG-PET for the evaluation of disease progression and response to treatment.

PATIENTS, METHODS

15 patients received a follow-up FDG-PET combined with computed tomography (integrated PET/CT) with a median of 6.5 years after the first PET in 1999. Number and location of enhanced metabolic activity in the area of AE lesions was determined. Quantification of intensity of metabolic activity was assessed by calculation of mean standardized uptake values.

RESULTS

AE lesions in 11/15 patients had been metabolically inactive initially, but only two showed permanent inactivity over the course of 81 months. Interestingly, in two patients metabolic activity was newly detected after 80 and 82 months. Benzimidazole treatment was intermittently discontinued in seven cases. Persisting activity at FDG-PET demanded continued benzimidazole treatment in four patients. Neither treatment duration, lesional size, calcifications nor regressive changes correlated with metabolic activity.

CONCLUSION

Treatment responses are heterogeneous and vary from progressive disease despite treatment to long-term inactive disease with discontinued treatment. Lack of metabolic activity indicates suppressed parasite activity and is not equivalent to parasite death. However, metabolic activity may remain suppressed for years, allowing for temporary treatment discontinuation. Relapses are reliably detected with PET and restarting benzimidazole treatment prevents parasite expansion.

[The mechanism of bone loss in rheumatoid arthritis. Description based on a case report]

Various factors influencing bone turnover and bone loss in rheumatoid arthritis (RA) are illustrated using the example of a postmenopausal woman with a highly active RA. In particular, the relationships between disease activity, vitamin D metabolism, parathyroid hormone (PTH) levels and calcium metabolism are described. High disease activity is associated with low levels of 25-hydroxycholecalciferol, and especially of 1.25-dihydroxycholecalciferol. Despite vitamin D deficiency, PTH levels were decreased and histomorphometric investigation of the iliac crest biopsy showed severe osteoporosis but no signs of osteomalacia. Suppression of the inflammatory disease activity of RA led to a normalisation of the serum levels of 1.25-dihydroxycholecalciferol and PTH. This was associated with a reduction in the initially increased levels of bone specific alkaline phosphatase to normal values. This case report shows a close relationship between disease activity and bone turnover in RA and indicates that early investigation and therapy of disturbances of bone metabolism in RA are necessary.

A case of sporadic Echinococcus granulosus infection originating from Southern Germany

A 67-year-old woman with cystic echinococcosis (CE) is presented. She had complained of upper abdominal discomfort due to large hepatic cysts. These cysts showed no typical infrastructure characteristic for CE and she had never left the rural areas of southern Germany. Most remarkably, this area is highly endemic for alveolar echinococcosis, caused by Echinococcus multilocularis, but only sporadic cases of CE have been described. Due to the discrepancy between positive Echinococcus serology, atypical morphology and residency in an area non-endemic for Echinococcus granulosus, diagnostic puncture was performed with albendazole coverage. Puncture was complicated by anaphylaxis, from which the patient recovered without sequelae. The diagnosis of CE was highly likely due to the combination of positive serology with post puncture anaphylaxis, increasing antibody titers and eosinophilia. Retrospectively, the cysts had initially corresponded to the WHO stage CE 1. The patient was treated with albendazole for 15 weeks. Under treatment, the parasitic membrane detached from the cyst wall, revealing characteristic morphology for CE, now corresponding to the WHO stage CE 3. The patient remained asymptomatic during follow-up visits.

Electrophoretic deposition of zirconia-Bioglass composite coatings for biomedical implants

Composite bilayer coatings on Ti6Al4V substrates were prepared by electrophoretic deposition, a simple and fast low temperature coating technique. Biocompatible yttrium-stabilized zirconia (YSZ) in the form of nanoparticles and bioactive Bioglass (45S5) in the form of microparticles were chosen as coating materials. The first layer consisted of 5 microm of YSZ, deposited with the intention to avoid any metal tissue contact. The second layer consisted of 15-microm thick 45S5-YSZ composite, supposed to react with the surrounding bone tissue and to enhance implant fixation. The adsorption of YSZ nanoparticles on 45S5 microparticles in organic suspension was found to invert the surface charge of the 45S5 particles from negative to positive. This enabled cathodic electrophoretic deposition of 45S5, avoiding uncontrolled anodization (oxidation) of the substrate. The coatings were sintered at 900 degrees C for 2 h under argon flow. The characterization was performed using SEM, EDX, and nanoindentation (cross section). Potential applications in the orthopedics field are discussed.