Tracing clinically-relevant antimicrobial resistances in Acinetobacter baumannii-calcoaceticus complex across diverse environments: A study spanning clinical, livestock, and wastewater treatment settings

Acinetobacter baumannii has become a prominent nosocomial pathogen, primarily owing to its remarkable ability to rapidly acquire resistance to a wide range of antimicrobial agents and its ability to persist in diverse environments. However, there is a lack of data on the molecular epidemiology and its potential implications for public health of A. baumannii strains exhibiting clinically significant resistances that originate from non-clinical environments. Therefore, the genetic characteristics and resistance mechanisms of 80 A. baumannii-calcoaceticus (ABC) complex isolates, sourced from environments associated with poultry and pig production, municipal wastewater treatment plants (WWTPs), and clinical settings, were investigated. In total, our study classified 54 isolates into 29 previously described sequence types (STs), while 26 isolates exhibited as-yet-unassigned STs. We identified a broad range of A. baumannii STs originating from poultry and pig production environments (e.g., ST10, ST238, ST240, ST267, ST345, ST370, ST372, ST1112 according to Pasteur scheme). These STs have also been documented in clinical settings worldwide, highlighting their clinical significance. These findings also raise concerns about the potential zoonotic transmission of certain STs associated with livestock environments. Furthermore, we observed that clinical isolates exhibited the highest diversity of antimicrobial resistance genes (ARGs). In contrast to non-clinical isolates, clinical isolates typically carried a significantly higher number of ARGs, ranging from 10 to 15. They were also the exclusive carriers of biocide resistance genes and acquired carbapenemases (blaOXA-23, blaOXA-58, blaOXA-72, blaGIM-1, blaNDM-1). Additionally, we observed that clinical strains displayed an increased capacity for carrying plasmids and undergoing genetic transformation. This heightened capability could be linked to the intense selective pressures commonly found within clinical settings. Our study provides comprehensive insights into essential aspects of ABC isolates originating from livestock-associated environments and clinical settings. We explored their resistance mechanisms and potential implications for public health, providing valuable knowledge for addressing these critical issues.

PSIII-10 Body temperature changes in piglets anesthetized for castration during the recovery phase

In several countries, an application of general anesthesia for pain prevention during castration is discussed. A disadvantage is the prolonged recovery phase, accompanied by severe body temperature drops in piglets. Aim of this study was to investigate effects on body temperature during recovery after anesthesia. Piglets were anesthetized, castrated and placed in boxes (0.24m2) for 4h. Before, 2 and 4h after the application (0.3ml ketamine+azaperone/kg BW), rectal temperatures (RT) and skin temperatures behind the ear (ST) were measured. In a first trial, impacts of infrared lamp (250W, 50-55cm height) and number of animals per box (3 vs 6) were analyzed (n = 30). In a complementary trial, infrared lamps’ height (60 vs 70cm) and piglet age were varied (n = 27) and temperatures measured half-hourly. Differences were estimated in linear models (SAS® 9.4). Mean RT before anesthesia was 39.1±0.4°C with ranges of less than 1.9°C. After 2h, mean RT in lamp-warmed piglets increased to 40.8°C (P < 0.01), whereas in absence of lamps RT dropped to 37.3 (P < 0.001), with significant differences between groups (P < 0.001). To prevent life-threatening cooling, piglets with RT as minimal as 33.5°C were warmed immediately, so that their mean RT after 4h was not different from initial temperatures. Animal number per box caused no differences. Variation between individual RT was up to 8.2°C at 2h (first trial). Means in the second trial did not differ, but variation pattern of individual temperatures was highest after 1h (6.1°C), indicating that individual differences regarding anesthetics or external factors might occur. When lamps hung lower ST were higher after 3h (P < 0.05) and 4h (P < 0.01). RT and ST were dependent on age after 0.5h (P < 0,05, respectively) and tendentious at 1h and 2h, indicating that older piglets can rely on more distinct temperature regulation abilities and use endogenous energy resources to regain homeostasis.

PSII-10 In vitro simulation of biofilm development and detachment in dairy cow troughs within the first 7 days after cleaning

Water is one of the most important factors concerning animal health and welfare. Therefore, an impairment of livestock water quality through biofilm development and detachment in dairy cow troughs represents a serious threat. To gain a better understanding of biofilm development and detachment, this study evaluates influencing factors in vitro. Cattle trough materials were inoculated with two naturally occurring bacterial cultures from different dairy farms. In a latin square design, detachment of a biofilm within a recommended cleaning interval of 7 days was investigated via total viable count (TVC) of the surrounding medium, depending on origin of culture, trough material (polyethylene or stainless steel), water temperature (5°C or 25°C) or nutrient availability (10% or 50% of nutrient broth, Merck KGaSA). At day 7, developed biofilm was investigated for TVC, Enterobacteriaceae spp. and with an adenosine triphosphate (ATP)-rapid test. All treatments were replicated at least 3 times. From the 4th day on, TVC in the surrounding medium increased by 1.5 log10 cfu/ml on polyethylene at 5°C, suggesting a maturation and detachment of a grown biofilm. Material and temperature affected biofilm detachment (P < 0.05). In temperature treatments with 25°C, TVC reached maximum within 24h, suggesting that biofilm detached earlier. The composition of the grown biofilm was affected by material, temperature, nutrient level, but not by starting culture. Higher Enterobacteriaceae spp. and TVC were observed on polyethylene than on stainless steel and at higher temperatures compared to lower (P < 0.001, respectively). Nutrient level significantly increased Enterobacteriaceae spp. growth. Rapid ATP-test results showed high Pearson correlations with biofilms TVC (r >0.74; P < 0.001) and might be a practical method to check trough hygiene on farms. Based on our in vitro data, cleaning intervals should be less than 4 days even at low temperatures. Nevertheless, more research is needed to verify data in practice.

22 Biological quality of drinking water for dairy cows - A risk oriented evaluation of influencing factors

Despite its importance, legal regulations and official guidelines regarding the quality of livestock drinking water are rather unspecific. The study aimed to investigate biological livestock drinking water quality considering influences of risk factors and relations to biofilm development and hygiene status of dairy troughs. On 24 dairy operations in Western Germany, 105 troughs were sampled. Water and biofilm were analyzed for aerobic total viable count (TVC), coliform count (CC), Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamases building bacteria (ESBL). 33 possible influences on biological water quality for each trough were either recorded or inquired. The troughs surface was examined with protein- and adenosine triphosphate (ATP)-rapid tests for hygiene. A mixed model and Spearman rank correlations (SAS 9.4) were used for estimating the probability of quality impairment in relation to recorded influences. Average TVC in water samples was 4.4 log10 cfu/ml. Coliforms were detectable in 94.3% of all troughs and E. coli in 48.6%. CC seems to be a more sensitive and suitable indicator to check fecal contamination because 16 water samples were positive for CC (>2.0 log10 cfu/ml) but negative for E. coli. MRSA were found in livestock drinking water of a single, and ESBL on three farms, suggesting that troughs might contribute to an exchange of antibiotic resistant bacteria in some dairy farms. Risk factors (P < 0.05) for at least one quality criteria (TVC, CC or E. coli) were water origin, trough type, degree of trough soiling, visible biofilm, ambient temperature and distance to the milking parlor. Water CC (r = 0.46; P < 0.001) and E. coli (r = 0.31; P < 0.01) correlated with their equivalent in biofilm and with hygiene tests on trough surfaces (0.31 >r >0.19; P < 0.05). Biological livestock drinking water quality can be improved by addressing the risk factors and be monitored with hygiene tests.

322 Challenges for porc value chains - simultaneous implementation of elevated animal welfare standards under field conditions

Consumers increasingly demand an improvement of animal welfare, in particular a refrainment from surgical interventions such as tail docking and castration. The aim of the study was to investigate effects of simultaneous implementation of elevated welfare standards under field conditions on valid indicators at the abattoir and product quality. Six different pig farms from birth to fattening were reimbursed for implementing elevated welfare standards (no tail docking in all and no castration of male piglets). Farmers were free to try Improvac® treatments and boar fattening. At the abattoir, welfare indicators like swellings and conditions of ears, claws, skin and tails were inspected on carcasses (pigs: n >1866). Meat quality was evaluated (n >185). Fixed effects of sex (females and barrows, Improvac® treated boars, boars) and farm were included in mixed models and Pearson correlations were calculated (SAS 9.4). Results were condensed with a Failure Mode and Effects Analysis (FMEA). Two farms managed to deliver around 90% of pigs with intact tails, whereas one completely failed (80% tails shorter than 1/3 of original length). Sex affected almost all welfare indicators, with least impairments in the females and barrows group and most in boars (P < 0.01). FMEA revealed concerns regarding animal welfare and meat quality in boars and immense variation between farms. For example, drip losses showed an interaction between sex and farm, suggesting that some farms provide better conditions for Improvac® treated pigs and boars than others. Besides that, transport duration from fattening location to abattoir correlated with swelling on fore and hind legs (0.15< r< 0.17; P < 0.001), but did not affect tail classification. In conclusion, the implementation of elevated animal welfare standards was highly dependent on the farm-specific management. Because used indicators were successfully assessed on the carcasses, they seem to be valid for future reward systems.

Bioinspired calcium phosphate mineralization on Net-Shape-Nonwoven chitosan scaffolds stimulates human bone marrow stromal cell differentiation

Chitosan fibers were processed using the Net-Shape-Nonwoven (NSN) technique in order to create porous scaffolds which were functionalized in two bioinspired ways: collagen type I coating and unique mineralization with organically modified hydroxyapatite (ormoHAP). While collagen is common to enhance cell attachment on surfaces, the electric-field assisted migration and deposition of ormoHAP on the surface of the NSN-scaffolds is a novel technique which enables sub-micrometer sized mineralization while maintaining the original pore structure. Microscopy revealed fast attachment and morphological adaptation of the cells on both, the pure and the functionalized NSN-scaffolds. Remarkably, the cell number of osteogenically induced hBMSC on ormoHAP-modified NSN-scaffolds increased 3.5-5 fold compared to pure NSN-scaffolds. Osteogenic differentiation of hBMSC/osteoblasts was highest on collagen-functionalized NSN-scaffolds. RT-PCR studies revealed gene expression of ALP, BSP II, and osteocalcin to be high for all NSN-scaffolds. Overall, the NSN-scaffold functionalization with collagen and ormoHAP improved attachment, proliferation, and differentiation of hBMSC and therefore revealed the remarkable potential of their application for the tissue engineering of bone.

Manipulation of osteoclastogenesis: Bioactive multiphasic silica/collagen composites and their effects of surface and degradation products

The intent of the present study was to demonstrate that multiphasic silica/collagen xerogels are able to manipulate cellular processes. These xerogels were prepared by a sol-gel approach allowing the incorporation of mineral phases. The resulting nanocomposites are designed as biomaterial for bone regeneration. Human osteoclasts derived from peripheral blood mononuclear cells were cultured both indirectly and directly, either in presence of different xerogel types or on their surface, to investigate the factor with the main influence on osteoclastogenesis. To this end, the incorporation of a third phase to silica/collagen xerogels was used to affect osteoclastogenesis. In cell culture, ambient ion conditions controlled by both the degradation products of the xerogel and the bioactivity-dependent ion release and reprecipitation were shown to have the main effect on osteoclast specific enzyme tartrate-resistant acid phosphatase (TRAP) 5b. Late stage of osteoclastogenesis characterized by resorption was strongly dependent on the xerogels composition. Surface chemistry of the xerogels was displayed to play an important role in osteoclast resorption. Biphasic silica/collagen xerogels and triphasic xerogels with calcium carbonate offered widespread resorbed areas, whereas hydroxyapatite containing xerogels showed distinctly reduced resorption. The incorporation of strontium carbonate and phosphate, respectively, as third phase changed TRAP 5b activity dose-dependently and inhibited resorption within 21 days. Quantitative evaluation on osteoclast differentiation was carried out using biochemical methods (TRAP 5b, cathepsin K) and was supported by confocal laser scanning microscopy and scanning electron microscopy (SEM). Qualitative estimation of resorption was carried out by SEM.

Effect of methionine supplementation in chicken feed on the quality and shelf life of fresh poultry meat

The aim of this study was to investigate the influence of different methionine sources and concentrations on the quality and spoilage process of broiler meat. The trial was comprised of 7 treatment groups: one basal group (suboptimal in Methionine+Cysteine; i.e., 0.89, 0.74, 0.69% in DM SID Met+Cys in starter, grower, and finisher diets, respectively) and 3 doses (0.10, 0.25, and 0.40%) of either DL-Methionine (DLM) or DL-2-hydroxy-4-methylthio butanoic acid (DL-HMTBA) on an equimolar basis of the DLM-supplemented groups. The broilers were fed the diets for 35 d, then slaughtered and processed. The filets were aerobically packed and stored under temperature controlled conditions at 4°C. Meat quality investigations were comprised of microbial investigations (total viable count and Pseudomonas spp.), pH and drip loss measurements of the filets. The shelf life of the meat samples was determined based on sensory parameters. After slaughtering, all supplemented meat samples showed a high quality, whereby no differences between the 2 methionine sources could be detected for the microbial load, pH, and drip loss. In comparison to the control group, the supplemented samples showed a higher sensory quality, characterized by a fresh smell and fresh red color. Methionine supplementation had a significant influence on meat quality parameters during storage. The microbial load, pH and drip loss of the chicken filets were positively correlated to the methionine concentration. Additionally, the microbial load at the end of storage was positively correlated to pH and drip loss values. Nevertheless, the microbial parameters were in a normal range and the positive correlation to methionine concentration did not affect the sensory shelf life. The mean sensory shelf life of the broiler filets varied between 7 to 9 d. During storage, no difference in the development of sensory parameters was observed between the supplemented groups, while the spoilage process of the basal group occurred slightly faster. In conclusion, methionine concentration, but not methionine source, effected meat quality parameters in breast muscles of broilers.

Electric field-assisted formation of organically modified hydroxyapatite (ormoHAP) spheres in carboxymethylated gelatin gels

A biomimetic strategy was developed in order to prepare organically modified hydroxyapatite (ormoHAP) with spherical shape. The technical approach is based on electric field-assisted migration of calcium ions and phosphate ions into a hydrogel composed of carboxymethylated gelatin. The electric field as well as the carboxymethylation using glucuronic acid (GlcA) significantly accelerates the mineralization process, which makes the process feasible for lab scale production of ormoHAP spheres and probably beyond. A further process was developed for gentle separation of the ormoHAP spheres from the gelatin gel without compromising the morphology of the mineral. The term ormoHAP was chosen since morphological analyses using electron microscopy (SEM, TEM) and element analysis (EDX, FT-IR, XRD) confirmed that carboxymethylated gelatin molecules use to act as organic templates for the formation of nanocrystalline HAP. The hydroxyapatite (HAP) crystals self-organize to form hollow spheres with diameters ranging from 100 to 500nm. The combination of the biocompatible chemical composition and the unique structure of the nanocomposites is considered to be a useful basis for future applications in functionalized degradable biomaterials.

STATEMENT OF SIGNIFICANCE

A novel bioinspired mineralization process was developed based on electric field-assisted migration of calcium and phosphate ions into biochemically carboxymethylated gelatin acting as organic template. Advantages over conventional hydroxyapatite include particle size distribution and homogeneity as well as achievable mechanical properties of relevant composites. Moreover, specifically developed calcium ion or phosphate ion release during degradation can be useful to adjust the fate of bone cells in order to manipulate remodeling processes. The hollow structure of the spheres can be useful for embedding drugs in the core, encapsulated by the highly mineralized outer shell. In this way, controlled drug release could be achieved, which enables advanced strategies for threating bone-related diseases, e.g. osteoporosis and multiple myeloma.

Effect of silica and hydroxyapatite mineralization on the mechanical properties and the biocompatibility of nanocomposite collagen scaffolds

A recently established materials concept of biomimetic composites based on silica, collagen, and calcium phosphates was adapted for the preparation of porous scaffolds suitable for tissue engineering applications. Mineralization was achieved by directed nucleation of silica on the templating organic phase during a sol-gel process with or without addition of hydroxyapatite. Both mineral phases (25 wt %, individually or combined in equal shares) influenced the scaffold's morphology at the nanoscale. Enhancement of apparent density and compressive strength was similar for silica or hydroxyapatite mineralization; however the stiffening effect of hydroxyapatite was much higher. All scaffold modifications provided proper conditions for adhesion, proliferation, and osteogenic differentiation of human bone marrow stromal cells. The open porosity allowed cells to migrate throughout the scaffolds while maintaining their viability, both confirmed by MTT staining and confocal laser scanning microscopy. Initial cell distributions were graduated due to collagen mineralization, but balanced out over the cultivation time of 28 days. RT-PCR analyses revealed higher gene expression of ALP but lower expression of BSP II and osteocalcin because of collagen mineralization. The results demonstrate that both silica and hydroxyapatite offer comparable possibilities to tailor mechanical properties of collagen-based scaffolds without being detrimental to in vitro biocompatibility.

Development of an osteoblast/osteoclast co-culture derived by human bone marrow stromal cells and human monocytes for biomaterials testing

The communication of bone-forming osteoblasts and bone-resorbing osteoclasts is a fundamental requirement for balanced bone remodelling. For biomaterial research, development of in vitro models is necessary to investigate this communication. In the present study human bone marrow stromal cells and human monocytes were cultivated in order to differentiate into osteoblasts and osteoclasts, respectively. Finally, a cultivation regime was identified which firstly induces the differentiation of the human bone marrow stromal cells followed by the induction of osteoclastogenesis through the osteoblasts formed--without the external addition of the factors RANKL and M-CSF. As a feedback on osteoblasts enhanced gene expression of BSP II was detected for modifications which facilitated the formation of large multinuclear osteoclasts. Phenotype characterization was performed by biochemical methods (DNA, LDH, ALP, TRAP 5b), gene expression analysis (ALP, BSP II, RANKL, IL-6, VTNR, CTSK, TRAP, OSCAR, CALCR) as well as light microscopy, confocal laser scanning microscopy, and scanning electron microscopy. After establishing this model on polystyrene, similar positive results were obtained for cultivation on a relevant bone substitution material--a composite xerogel of silica, collagen, and calcium phosphate.

In vitro osteoclastogenesis on textile chitosan scaffold

Textile chitosan fibre scaffolds were evaluated in terms of interaction with osteoclast-like cells, derived from human primary monocytes. Part of the scaffolds was further modified by coating with fibrillar collagen type I in order to make the surface biocompatible. Monocytes were cultured directly on the scaffolds in the presence of macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor kappaB ligand (RANKL) for up to 18 days. Confocal laser scanning microscopy (CLSM) as well as scanning electron microscopy (SEM) revealed the formation of multinuclear osteoclast-like cells on both the raw chitosan fibres and the collagen-coated scaffolds. The modified surface supported the osteoclastogenesis. Differentiation towards the osteoclastic lineage was confirmed by the microscopic detection of cathepsin K, tartrate resistant acid phosphatase (TRAP), acidic compartments using 3-(2,4-dinitroanillino)-3'-amino-N-methyldipropylamine (DAMP), immunological detection of TRAP isoform 5b, and analysis of gene expression of the osteoclastic markers TRAP, cathepsin K, vitronectin receptor, and calcitonin receptor using reverse transcription-polymerase chain reaction (RT-PCR). The feature of the collagen-coated but also of the raw chitosan fibre scaffolds to support attachment and differentiation of human monocytes facilitates cell-induced material resorption--one main requirement for successful bone tissue engineering.

Assessment of anti-inflammatory activity of Poria cocos in sodium lauryl sulphate-induced irritant contact dermatitis

OBJECTIVE

In the present study, we evaluated the anti-inflammatory activity of Poria cocos (PoCo) on experimentally induced irritant contact dermatitis (ICD) in a repeated sodium lauryl sulphate (SLS) irritation model.

METHODS

The anti-irritative effect of PoCo was evaluated with a visual score and quantified by non-invasive bioengineering methods, namely chromametry and transepidermal water loss. Three concentrations of PoCo in base cream DAC (amphiphilic emollient; German pharmacopoeia) were tested in a 4-day repetitive irritation test using SLS.

RESULTS

A statistically significant anti-inflammatory activity was observed for PoCo by all three methods when applied in parallel to the induction period of ICD. Application of PoCo after induction of ICD once a day for 5 days, starting just at the end of 4 days, was without any effect.

CONCLUSION

An anti-inflammatory efficacy of PoCo on the elicitation phase of the ICD induced by repeated SLS test could be observed and quantified by three independent, non-invasive biophysical assessment parameters. This effect can be explained by its influence on pro-inflammatory enzymes, namely phospholipase A2.

The quality of human skin xenografts on SCID mice: a noninvasive bioengineering approach

BACKGROUND

Animal models are important tools for studies in skin physiology and pathophysiology. Due to substantial differences in skin characteristics such as thickness and number of adnexa, the results of animal studies cannot always be directly transferred to the human situation. Therefore, transplantation of human skin on to SCID (severe combined immunodeficiency) mice might offer a promising tool to perform studies in viable human skin without the direct need for human volunteers.

OBJECTIVES

To characterize the physiological and anatomical changes of a human skin transplant on a SCID animal host.

METHODS

In this study human skin was transplanted on to 32 SCID mice and followed for 6 months. Barrier function was assessed by transepidermal water loss (TEWL; tewametry) and moisture content of the stratum corneum was studied by measurement of electrical capacitance (corneometry).

RESULTS

The results showed considerable deviations of TEWL values and skin hydration between the grafts and human skin in vivo. The human skin showed epidermal hyperkeratosis and moderate sclerosis of the corium 4 and 6 months after transplantation on to SCID mice.

CONCLUSIONS

Our results indicate that human skin does not completely preserve its physiological and morphological properties after transplantation on to SCID mice. Therefore, results from experiments using this model system need to be discussed cautiously.

Intra-articular ganglion cysts of the knee joint: a report of 85 cases and review of the literature

Intra-articular ganglia and cysts of the knee joint are rare and mostly incidental findings in MRI and arthroscopy. During a period of 15 years, nearly 8000 knees were arthroscopically examined. In total, 85 intra-articular soft tissue masses were found within the knee cavity. Of these, 76 were incidental and asymptomatic findings in arthroscopy performed for treatment of osteoarthritic symptoms. Several repeated minor knee traumata were reported in this group but no histories of serious traumatic events. Nine ganglion cysts were obviously solely responsible for the intermittent or chronic non-specific knee discomfort, and classified as symptomatic. There were no histories of previous injury to the knees, no clinical signs of instabilities or meniscal and femoropatellar pathologies, and no associated further intra-articular lesions in arthroscopy. Forty-nine cystic masses originated from the ACL, 16 from the PCL, 12 from the anterior (eight medial, four lateral) and three from the posterior horn of the menisci (two medial, one lateral). Three were located in the infrapatellar fat pad, one arose from a medial plica and one from a subchondral bone cyst. All ganglion cysts were successfully resected or excised using arthroscopic technique. A review of the literature is given and compared with the findings and data of this study.

Erythema induratum of Bazin and Poncet's disease -- successful treatment with antitubercular drugs

Erythema induratum of Bazin (EIB) is considered a tuberculide reaction and consists of recurrent painful nodules predominantly on the calves. Clinically it has common features with diseases like nodular vasculitis, perniosis, polyarteritis nodosa and erythema nodosum. Poncet's disease is a reactive arthritis that may accompany tuberculosis. We report a case of a young woman in which the simultaneous occurrence of erythema induratum of Bazin and Poncet's disease led to a clinical picture very similar to Löfgren's syndrome. The final diagnosis was obtained by polymerase chain reaction detection of mycobacterial DNA in a skin biopsy. A systemic therapy with tuberculostatic drugs led to the disappearance of symptoms. The presented case shows the usefulness of polymerase chain reaction diagnostics in EIB patients without other clinical signs of tuberculosis and a confusing combination of symptoms, and further confirms the presence of mycobacterial DNA in EIB lesions.

Efficacy measurement of topical antihistamines: a review

More and more antihistamines are used in gels or ointments for local antipruritic therapy. Among other factors, the efficacy is dependent on the penetration properties of the respective agents and the optimal choice of vehicle substances. To avoid expensive treatment with unsatisfying success, a reliable efficacy measurement would be desirable prior to the admission of new topical antihistamine preparations. Therefore we reviewed the literature for common methods to assess the efficacy of local antihistamines in healthy volunteers. The principle is to apply the test substance to marked test areas and to challenge the skin after a certain time with a standardised amount of histamine, allergens or mast-cell-degranulating substances. For the test evaluation, the areas of wheal, flare and itch are measured and compared between antihistamine-treated and control fields. Challenge models and most of the described evaluation methods are suited for the preliminary efficacy measurement of antihistamines. However, to be able to compare the results, a standardised procedure used by all investigators would be desirable.

The atopy patch test -- reproducibility and comparison of different evaluation methods

BACKGROUND

There is still a lack of standardization of the atopy patch test (APT) in test procedures and evaluation methods. Our aim was to examine the reproducibility of APT results and to compare visual evaluation to chromametry and laser Doppler imaging.

METHODS

Fifty-two volunteers with atopic eczema/dermatitis syndrome (AEDS) were included. The APT was performed on tape-stripped and unstripped test fields on their backs using cat dander, house dust mite and grass pollen allergens from two different suppliers. Responders were re-tested 4-12 weeks later with the same allergens on their forearms.

RESULTS

Using Allergopharma allergens, 14 (26.9%) volunteers showed one or more positive reactions. The reproducibility rate was 56.3%. The Erlangen atopy score in APT-positive and negative volunteers was 19 +/- 6 vs 15 +/- 6. The test agreement in volunteers tested with both allergens, from Allergopharma and Stallergènes, was poor. Correlation of the results between the three evaluation methods was significant (P < or = 0.001).

CONCLUSIONS

The low reproducibility rate of APT results and the poor inter-test-agreement using allergens from different suppliers show that much work remains to make the APT a reliable tool in identifying relevant aeroallergens that lead to flare ups of AEDS. Compared to chromametry and laser Doppler imaging, visual scoring was superior in differentiation between irritative and allergic reactions.

Tacrolimus enhances irritation in a 5-day human irritancy in vivo model

Tacrolimus (FK 506) is a macrolide discovered in 1984 as a metabolic product of Streptomyces tsukabaensis. It has been used successfully in treating atopic dermatitis, allergic contact dermatitis, lichen planus mucosae and pyoderma gangrenosum. In the present study, we evaluated the anti-inflammatory activity of FK 506 in 2 human skin inflammation models. FK 506 as Protopic(R) cream was tested (i) in a 4-day repetitive irritation test with 2 x daily application of sodium lauryl sulphate (SLS), and (ii) in a UVB erythema model. The effect was evaluated visually and quantified by non-invasive bioengineering methods, namely chromametry and tewametry (TEWL). When FK 506 was applied 30 min after SLS irritation, an increased inflammation in comparison to controls was observed with all 3 methods, with only the TEWL data reaching statistical significance. 1 x daily application of FK 506 for 5 days, starting at the end of the 4-day irritation period, was without any effect. Similarly, no effect of FK 506 was seen in the UVB model. In conclusion, FK 506 was shown to enhance experimentally induced irritant contact dermatitis and not to accelerate healing of irritant contact dermatitis and UVB erythema.

[Calculation of 3-D deformity in scoliosis by MRI of the total spine in two perpendicular reconstructed planes]

AIM

Scoliosis is a spinal deformity that is more complex and does not exist in one plane only. There have been many attempts to analyse three-dimensional spinal deformity, however, these procedures necessitate higher radiation doses.

METHOD

In this study we define angles according to the Cobb Definition. By means of trigonometrical evaluation, 3D calculation of spinal deformity is demonstrated using MRI of the total spine in two reconstructed perpendicular planes. 3D spinal analysis was performed on 41 female and 7 male patients with scoliosis.

RESULTS

79 angles were measured by using the Cobb angle in reconstructed coronal plane of MRI of the total spine and, in addition, by using our method. The scoliosis Cobb angles ranged from 11 - 59 degrees (mean: 23 degrees +/- 9 degrees ), the real angles ranged from 12 - 70 degrees (mean: 32 +/- 14 degrees ). There was a poor correlation between Cobb angles and the 3D calculated angles (r = 0.37; p < 0.0001).

CONCLUSION

Our method enables us to determine the real angle of scoliosis and to avoid techniques with any radiation risk for the patient.

Probiotic Lactobacillus dose required to restore and maintain a normal vaginal flora

Forty-two healthy women were randomized to receive one of three encapsulated Lactobacillus rhamnosus GR-1 plus Lactobacillus fermentum RC-14 probiotic dosage regimens or L. rhamnosus GG by mouth each day for 28 days. However, the vaginal flora, assessed by Nugent scoring, was only normal in 40% of the cases, and 14 patients had asymptomatic bacterial vaginosis. Treatment with L. rhamnosus GR-1/L. fermentum RC-14 once and twice daily correlated with a healthy vaginal flora in up to 90% of patients, and 7/11 patients with bacterial vaginosis converted to normal or intermediate scores within 1 month. Ingestion of L. rhamnosus GG failed to have an effect. This study confirms the potential efficacy of orally administered lactobacilli as a non-chemotherapeutic means to restore and maintain a normal urogenital flora, and shows that over 10(8) viable organisms per day is the required dose.

Tandem application of sodium lauryl sulfate and n-propanol does not lead to enhancement of cumulative skin irritation

Irritant contact dermatitis has a broad spectrum of clinical features and is a leading cause of occupational disease worldwide. It has been shown previously that a combination of chemically different irritants may cause an additive effect compared to single application of these substances. In this study, tandem application of sodium lauryl sulfate and n-propanol was investigated in 20 human volunteers using non-invasive bioengineering methods, such as measurement of transepidermal water loss and chromametry. N-propanol did not enhance cumulative skin irritation when used with sodium lauryl sulfate, as has been reported for toluene. As n-propanol is the active ingredient in many disinfectants, this is of particular interest regarding occupational skin irritation in health care workers.

Evidence of starch inclusion complexation with lactones

Starch, in particular the linear amylose, is able to form inclusion complexes with a wide spectrum of ligand molecules, among them flavor compounds. The complexing ability of a homologous series of gamma- and delta-lactones with potato starch was followed by amperometric iodine titration, differential scanning calorimetry, and wide-angle X-ray diffraction measurements. Lactones with a linear chain of a size > or = C(5) form inclusion complexes with starch, whereas lactones with a short linear chain, such as gamma-heptalactone, show poor complexing ability. The thermal stability of starch-lactone complexes increases with increasing chain length of the lactone. In general, lactones induce the formation of V(h) helices. Only delta-decalactone complexes with starch were not definitely identified as V(h) amylose helices. Complexation of starch dispersions with lactones induce turbidity and gelation or phase separation, both phenomena being the result of microphase separation.

Oral probiotics can resolve urogenital infections

We report the first clinical evidence that probiotic lactobacilli can be delivered to the vagina following oral intake. In 10 women with a history of recurrent yeast vaginitis, bacterial vaginosis (BV) and urinary tract infections, strains Lactobacillus rhamnosus GR-1 and Lactobacillus fermentum RC-14 suspended in skim milk and given twice daily for 14 days, were recovered from the vagina and identified by morphology and molecular typing within 1 week of commencement of therapy. In six cases of asymptomatic BV or intermediate BV (based upon Nugent scoring) was resolved within 1 week of therapy.

Identification of collagen-binding proteins in Lactobacillus spp. with surface-enhanced laser desorption/ionization-time of flight ProteinChip technology

Biosurfactants produced by Lactobacillus fermentum RC-14, L. rhamnosus GR-1 and 36, and L. casei Shirota were found to contain proteins that bind to both collagen types III and VI, as determined by surface-enhanced laser desorption/ionization (SELDI)-time of flight mass spectrometry. Both collagen types III and VI immobilized on SELDI preactivated ProteinChip arrays detected several different sizes (2 to 48 kDa) of collagen-binding proteins. Overall, the RC-14-produced biosurfactant contained the greatest number of collagen-binding proteins (RC-14 > GR-1 > 36 > Shirota), including the mature form of a previously cloned 29-kDa collagen-binding protein (referred to in its mature 26-kDa form). Although biosurfactants isolated from L. casei Shirota and L. rhamnosus 36 and GR-1 also contain several collagen-binding proteins, they do not contain the 26-kDa collagen-binding protein. Together, these results demonstrate the utility of the SELDI system as a means of rapidly characterizing clinically important but complex biosurfactant solutions.

Purification and characterization of a surface-binding protein from Lactobacillus fermentum RC-14 that inhibits adhesion of Enterococcus faecalis 1131

Lactobacilli have been shown to be important in the maintenance of the healthy urogenital flora. One strain, Lactobacillus fermentum RC-14, releases surface-active components which can inhibit adhesion of uropathogenic bacteria. Using a quantitative method for determining inhibition of adhesion, a protein with high anti-adhesive properties against Enterococcus faecalis 1131 was purified. The N-terminal sequence of the 29-kDa protein was identical to that of a collagen-binding protein from Lactobacillus reuteri NCIB 11951, and exhibited close homology with a basic surface protein from L. fermentum BR11. The results suggest that this anti-adhesive cell surface protein of Lactobacillus could protect against uropathogens by preventing their adhesion. the Federation of European Microbiological Societies.

Structural chemistry of polycyclic heteroaromatic compounds. Part XI. Photoelectron spectra and electronic structures of tetracyclic hetarenes of the triphenylene type

The UV photoelectron spectra of several tetracyclic heteroaromatic compounds (2-9) which are pi-isoelectronic with triphenylene (1) have been recorded and analysed making use of semiempirical AM1 and PM3 as well as ab initio/DFT B3LYP calculations. In one series of compounds (2-7), the peripheral benzene rings of 1 are successively substituted by thiophene rings that are either [b]- or [c]-annellated with the central benzene unit. In 2-7 only marginal shifts are found for most of the IPs of electrons. In the benzotrithiophenes 5-7, a systematic variation is displayed by IP(pi7). Compared to 1, the pi electron system of benzo[c]trithiophene (7) is approximately two times as much destabilized as in the isomers 5 and 6 with [b]annellated thiophene rings. The IP[n(S)] values of the thiophene derivatives 2-7 indicate that these orbitals are clearly destabilized relative to thiophene. The same holds for the n(O) orbital of the furane derivative 9 in comparison with that of furane. In 9, only the higher pi MOs (pi7-pi9) are destabilized whereas the lower levels (pi1-pi4) are stabilized, and those in between (pi5-pi6) remain essentially unshifted. In the pyrrole derivative 8, all pi MOs are substantially destabilized by about 0.5-1.6 eV relative to 1.

Analysis of fast dynamic processes in living cells: high-resolution and high-speed dual-color imaging combined with automated image analysis

The generation of spectral mutants of the green fluorescent protein (GFP) set the stage for multiple-color imaging in living cells. However, the use of this technique has been limited by a spectral overlap of the available GFP mutants and/or by insufficient resolution in both time and space. Using a new setup for dual-color imaging, we demonstrate here the visualization of small, fast moving vesicular structures with a high time resolution. Two GFP-fusion proteins were generated: human chromogranin B, a secretory granule matrix protein, and phogrin, a secretory granule membrane protein. They were tagged with enhanced yellow fluorescent protein (EYFP) and enhanced cyan fluorescent protein (ECFP), respectively. Both fusion proteins were cotransfected in Vero cells, a cell line from green monkey kidney. EYFP and ECFP were excited sequentially at high time rates using a monochromator. Charged coupled device (CCD)-based image acquisition resulted in 5-8 dual-color images per second, with a resolution sufficient to detect transport vesicles in mammalian cells. Under these conditions, a fully automated time-resolved analysis of the movement of color-coded objects was achieved. The development of specialized software permitted the analysis of the extent of colocalization between the two differentially labeled sets of cellular structures over time. This technical advance will provide an important tool to study the dynamic interactions of subcellular structures in living cells.

Overexpression of CXC-chemokines and CXC-chemokine receptor type II constitute an autocrine growth mechanism in the epidermoid carcinoma cells KB and A431

The CXC-chemokines Groalpha and interleukin-8 (IL-8) are well characterized growth factors for melanoma cells. Here the constitutive expression of Groalpha, IL-8 and their receptors (CXCR1 and CXCR2) as well as their functional involvement in the proliferation response were analyzed in normal keratinocytes and epidermoid carcinoma cell lines A431 and KB. Flow cytometric measurements, ELISA and semi-quantitative RT-PCR revealed low constitutive protein secretion and mRNA expression of both CXC-chemokines as well as CXCR1 and 2 in normal keratinocytes, whereas significant higher levels of CXC-chemokines and CXCR2 were deteced in epidermoid carcinoma cells. Proliferation of epidermoid carcinoma cells could be induced by CXC-chemokines and constitutive proliferation could be inhibited by neutralizing antibodies against CXC-chemokines and CXCR2. These studies indicate that constitutive Groalpha, IL-8 and CXCR2 protein expression enable an autocrine growth mechanism in epidermoid carcinoma cells.

Comparison of secretory responses as measured by membrane capacitance and by amperometry

We have compared capacitance and amperometric measurements in bovine chromaffin cells when secretion was elicited by flash photolysis of caged-calcium or step depolarizations. Total amperometric charge depended linearly on the amount of capacitance increase in both types of experiments. Furthermore, the properties of resolvable amperometric spikes after flashes were comparable to those observed after depolarizations, and their timing was compatible with the rate of capacitance increase. For a more detailed comparison, we used Monte Carlo simulations of multiple amperometric events occurring randomly over the surface of a sphere and summing together, to generate a reference amperometric signal for a given measured capacitance increase. Even after correction for endocytotic processes, the time courses of the integrated experimental records lagged behind the integrated Monte Carlo records by approximately 50 ms in flash and depolarization experiments. This delay was larger by approximately 40 ms than what can be expected from the "pre-foot delay" or the foot duration. Possible sources for the remaining delay could be diffusional barriers like the patch-pipette and the chamber bottom, which are not taken into account in the model. We also applied a novel type of fluctuation analysis to estimate the relative quantum size of an amperometric event. On average the estimates from experimental amperometric traces, in both flash and depolarization experiments, were 3-5 times smaller than estimates from simulated ones. This discrepancy can be due to contributions to the amperometric current from small vesicles, preferred release from cellular regions orientated toward the chamber bottom, or abundance of "foot-only" events. In conclusion, amperometric signals in flash and depolarization experiments displayed similar delayed average time courses and a lower estimate for the relative quantum size compared to the modeled amperometric signals. However, individual amperometric spikes were in agreement with expectations derived from capacitance signals.

Modulation of in vivo migratory function of alpha 2 beta 1 integrin in mouse liver

We report herein that expression of alpha 2 beta 1 integrin increased human erythroleukemia K562 transfectant (KX2C2) cell movement after extravasation into liver parenchyma. In contrast, a previous study demonstrated that alpha 2 beta 1 expression conferred a stationary phenotype to human rhabdomyosarcoma RD transfectant (RDX2C2) cells after extravasation into the liver. We therefore assessed the adhesive and migratory function of alpha 2 beta 1 on KX2C2 and RDX2C2 cells using a alpha 2 beta 1-specific stimulatory monoclonal antibody (mAb), JBS2, and a blocking mAb, BHA2.1. In comparison with RDX2C2 cells, KX2C2 were only weakly adherent to collagen and laminin. JBS2 stimulated alpha 2 beta 1-mediated interaction of KX2C2 cells with both collagen and laminin resulting in increases in cell movement on both matrix proteins. In the presence of Mn2+, JBS2-stimulated adhesion on collagen beyond an optimal level for cell movement. In comparison, an increase in RDX2C2 cell movement on collagen required a reduction in its adhesive strength provided by the blocking mAb BHA2.1. Consistent with these in vitro findings, in vivo videomicroscopy revealed that alpha 2 beta 1-mediated postextravasation cell movement of KX2C2 cells in the liver tissue could also be stimulated by JBS2. Thus, results demonstrate that alpha 2 beta 1 expression can modulate postextravasation cell movement by conferring either a stationary or motile phenotype to different cell types. These findings may be related to the differing metastatic activities of different tumor cell types.

Alteration of Ca2+ dependence of neurotransmitter release by disruption of Ca2+ channel/syntaxin interaction

Presynaptic N-type calcium channels interact with syntaxin and synaptosome-associated protein of 25 kDa (SNAP-25) through a binding site in the intracellular loop connecting domains II and III of the alpha1 subunit. This binding region was loaded into embryonic spinal neurons of Xenopus by early blastomere injection. After culturing, synaptic transmission of peptide-loaded and control cells was compared by measuring postsynaptic responses under different external Ca2+ concentrations. The relative transmitter release of injected neurons was reduced by approximately 25% at physiological Ca2+ concentration, whereas injection of the corresponding region of the L-type Ca2+ channel had virtually no effect. When applied to a theoretical model, these results imply that 70% of the formerly linked vesicles have been uncoupled after action of the peptide. Our data suggest that severing the physical interaction between presynaptic calcium channels and synaptic proteins will not prevent synaptic transmission at this synapse but will make it less efficient by shifting its Ca2+ dependence to higher values.

RISC (Repolarization-induced stop of caffeine-contracture) is not due to store depletion in cultured murine skeletal muscle

We have combined the patch-clamp technique with Fura-2 measurements to investigate whether RISC (repolarization-induced stop of caffeine-contracture) is a consequence of store depletion in cultured skeletal muscles of rats and mice. Weak depolarizations (-45 to -40 mV) of long duration induced a barely detectable Ca2+ transient. Even under these conditions, caffeine-activated Ca2+transients (CafTs) were terminated upon membrane repolarization (-70 mV) at all stages of CafT. Following the peak of the CafT, massive Ca2+ release was elicited by either flash-photolysis of caged Ca2+ or further depolarization to 0 mV, demonstrating the lack of store depletion. Thus, RISC is not due primarily to store depletion but to closure of the Ca2+ release channels possibly through a mechanical interaction with voltage sensors. RISC was not present in rat heart muscle, further supporting a role of direct interaction in skeletal muscle.

Mechanisms determining the time course of secretion in neuroendocrine cells

Transmitter release from chromaffin cells differs from that in synapses in that it persists for a longer time after Ca2+ entry has stopped. This prolonged secretion is not due to a delay between vesicle fusion and transmitter release, nor to slow detection of released substance: step increases in capacitance due to single vesicle fusion precede the release detected by amperometry by only a few milliseconds. The persistence of secretion after a depolarization is reduced by addition of mobile calcium buffer. This suggests that most of the delay is due to diffusion of Ca2+ between channels and release sites, implying that Ca2+ channels and secretory vesicles are not colocalized in chromaffin cells, in contrast to presynaptic active zones.