Control of Surface Wound Infection: Skin Versus Synthetic Grafts

Auto-, iso-, or xenografts of skin and synthetics placed on surface wounds freshly contaminated with Pseudomonas aeruginosa stabilizes the wound bacterial population in rats over a 24-h period. When these wounds contained a bacterial contamination established for 24 h prior to grafting, only skin and the synthetic polyhydroxyethylmethacrylate were effective in lowering the initial bacterial concentration. Polyurethane foam and nylon velour were not effective in the established infection model. Skin placed on a contaminated wound for 2 h or longer appeared to equilibrate with the underlying muscle so that the bacterial count per milligram of skin was similar to that of the muscle. It was suggested that this preparation would be useful to obtain an estimate of surface contamination without biopsy of the infected muscle. Skin grafts in place for 2 h significantly lowered the bacterial count in a wound with an established infection. A second decrease occurred between 4 and 24 h after grafting. Histological studies of contaminated and exposed panniculus muscle showed that leukocytes tend to migrate from the muscle surface to its base. Skin grafts and polyhydroxyethylmethacrylate appear to reverse the white cell migration so that the cells move toward the surface of the muscle with preservation of normal staining characteristics in the muscle. It is suggested that this alteration in cell movement after graft application might modify the white cell function and result in a greater bactericidal activity. Apparently, grafts lower bacterial levels in an established infection by modifying the host response to the surface contamination.     

Monocyte subsets in bone marrow grafts may contribute to a low incidence of acute graft‐vs‐host disease for young donors

Young donors are associated with a lower cumulative incidence of acute graft‐vs‐host disease (aGVHD) after allogenic haematopoietic stem cell transplantation (allo‐HSCT) than old donors. Although grafts are harvested from healthy donors, it is unclear whether donor age is associated with aGVHD occurrence owing to its effect on cell compositions in grafts. Moreover, the differences in monocyte subsets in grafts between young and old donors and the association between monocyte subsets in bone marrow (BM) grafts and aGVHD remain to be elucidated. In the current study, non‐classical monocytes and the CD4⁺/CD8⁺ T cell ratio were remarkably decreased in BM grafts in donors <30 years old. Multivariate analysis further revealed that the level of non‐classical monocytes in BM grafts (≥0.31 × 10⁶/kg) was an independent risk factor for the occurrence of II‐IV aGVHD. In summary, our data indicate that non‐classical monocytes in BM grafts may help identify patients at high risk for aGVHD after allo‐HSCT. Although further validation is required, our results suggest that the low level of non‐classical monocytes and a low ratio of CD4⁺/CD8⁺ T cell in BM grafts may be correlated with the lower incidence of aGVHD in young donors.     

Response of Antarctic Soil Bacterial Assemblages to Contamination by Diesel Fuel and Crude Oil

Abstract The effects of diesel fuel and ``Arabian light' crude oil addition on Antarctic bacterial assemblages were studied in four contaminated soils during 1 year in the Terre Adelie land area. Monthly sampling allowed a regular survey of the bacterial changes occurring in the contaminated soils. All samples were analyzed for total bacteria, heterotrophic culturable microbiota, and hydrocarbon-utilizing microbiota. Crude oil contamination induced an initial increase of all bacterial parameters in all contaminated soils. Diesel oil contamination had a more complex effect. Hydrocarbon degrading bacterial abundance increases occurred after diesel oil addition. In contrast, general heterotrophic bacterial abundance could significantly decrease in the same conditions. In all cases the stimulatory effects of oil addition disappeared after several months of contamination. Received: 13 April 1999; Accepted: 24 February 2000; Online Publication: 29 May 2000     

A subset of asialo GM1+ cells play a protective role in the occurrence of graft-versus-host disease in mice

In three different murine models of bone marrow (BM) transplantation the capacity of asialo GM1+ cells to suppress graft-vs-host disease (GVHD) was investigated. In a first model, total lymphoid irradiation (TLI)-treated BALB/C mice were given 1 mg of anti-asialo GM1 antibody. This led to the disappearance of functional suppressor cells after TLI. Injections of anti-asialo GM1 into TLI-treated BALB/C mice before infusion of 30 x 10(6) fully allogeneic (C3H) BM cells, led to a significantly decreased survival rate as compared to TLI-treated mice injected with control serum before BM transplantation (survival 29 and 83%, respectively, at 120 days after transplantation, p = 0.0032 log rank). The mortality of the former group was due to GVHD as 1 degree all dying animals showed clinical and histologic signs of GVHD, 2 degrees all animals were chimeric and 3 degrees mice receiving no or syngeneic BALB/C BM had excellent survival rates excluding BM aplasia or increased susceptibility for infections as reason for the mortality of the allogeneic BM recipients. In a second model, asialo GM1+ cells were removed in vitro from the C3H BM inoculum before injection into lethally irradiated (9 Gy) BALB/C recipients. In mice kept in specific pathogen-free conditions, this procedure resulted into a significant mortality (12/12) as compared to mice receiving BM pretreated with control serum (1/12, p = 0.0001 log rank). When kept in conventional housing, GVHD occurred in both groups but much earlier in the group receiving anti-asialo GM1-treated BM (median survival time 6 vs 46 days for the control mice, p = 0.001 log rank). No animal receiving anti-asialo GM1 and treated with syngeneic BM died, thus excluding toxicity, increased susceptibility to infections, or decreased graft take as a cause of mortality. In a last model, asialo GM1 cells were removed from syngeneic BM in a BM transplantation model in which T cell-depleted syngeneic (BALB/C) and non-T cell-depleted allogeneic (C3H) BM was administered to lethally irradiated (9 Gy) BALB/C mice. Also in this model GVHD-related mortality only occurred in the group of mice receiving syngeneic BM from which asialo GM+ cells were depleted before infusion (3/12). Our experiments thus clearly show that asialo GM1+ cells from both recipient (the TLI model) as well as donor origin (the TBI experiments) can suppress the occurrence of GVHD.     

Low-dose infectivity of Staphylococcus aureus (SMH strain) in traumatized rat tibiae provides a model for studying early events in contaminated bone injuries

Animal models of post-traumatic acute osteomyelitis (OM) that closely mimic human scenarios, including infection prophylactic procedures such as debridement and lavage, may provide a better understanding of OM. We contaminated mechanically traumatized rat tibiae (n = 69) with various doses of a Staphylococcus aureus strain (SMH) known to cause human OM and then performed curettage and lavage. Tibiae were harvested 24 h after lavage for assessment of bacterial load and determination of minimal infective doses for 50% (ID50) and 95% (ID95) of rats. Some experiments varied tibial harvest time after lavage (n = 10); for progressive infection, tibiae were evaluated at 7 and 15 days after contamination (n = 17 for each time point). At 24 h after contamination, the ID50 was 1.8 x 10(3) CFU, and the ID95 was 9.2 x 10(3) CFU. Tibial bacterial loads did not increase with inocula greater than the ID95. Lavage removed many bacteria from bone, but it did not prevent subsequent infection or disease. At 15 days after contamination, most tibiae (14 of 17) were infected, with macroscopic and radiological signs of established OM. This newly described rat OM model, with a low ID95 despite prophylactic curettage and lavage, closely mimics events in contaminated human bone injuries. This situation will allow study of early factors in contaminated bone injuries, including clinical interventions that may reduce infection and prevent disease.     

PBSC collection in extremely low weight infants: a single-center experience

BACKGROUND: Peripheral blood progenitor cell (PBPC) collection has become the main source of hematopoietic cells for high-dose chemotherapy with stem cell rescue and, in some protocols, for allogeneic hematopoietic transplantation. This procedure is complicated in the smallest children because of difficulties related to their weight, and there is little published experience. We have conducted a prospective study to analyze the incidence of adverse events during PBPC collection in the smallest children (< or = 10 kg). METHODS: From January 2000 to November 2005, 257 leukapheresis were performed in our unit, and 13 of them (5%) in 12 children weighing up to 10 kg (median 9 kg, range 5.8-10.9 kg). RESULTS: Most cases had hypovolemic signs during the procedure (usually tachycardia); six cases had hypotension, five of them with pallor and diaphoresis, and, of those, two also had nausea. In all these cases infusion of saline or plasma volume expanders resolved the clinical findings. In two cases the nausea related to hypocalcemia was resolved after calcium gluconate infusion. Changes in platelet counts were also remarkable, with a median platelet loss of 52%. DISCUSSION: Leukapheresis with continuous-flow cell separators has frequent complications related to volume shift in the smallest children. These adverse events are mild and easily resolved with standard measures for hypovolemia, as plasma expander or normal saline infusions. However, we recommend that the procedure should only be performed by teams with extensive experience in the field.     

Influence of the degree of donor bone marrow hyperplasia on patient clinical outcomes after allogeneic hematopoietic stem cell transplantation

This study evaluated the influence of the degree of donor bone marrow(BM) hyperplasia on patient clinical outcomes after allogeneic hematopoietic stem cell transplantation(allo-HSCT). Twelve patients received allo-HSCT from hypoplastic BM donors between January 2010 and December 2017. Forty-eight patients whose donors demonstrated BM hyperplasia were selected using a propensity score matching method(1:4). Primary graft failure including poor graft function and graft rejection did not occur in two groups. In BM hypoplasia and hyperplasia groups,the cumulative incidence(CI) of neutrophil engraftment at day 28(91.7% vs. 93.8%, P=0.75), platelet engraftment at day 150(83.3% vs. 93.8%, P=0.48), the median time to myeloid engraftment(14 days vs. 14 days, P=0.85) and platelet engraftment(14 days vs. 14 days, P=0.85) were comparable. The 3-year progression-free survival, overall survival, CI of non-relapse mortality and relapse were 67.8% vs. 71.7%(P=0.98), 69.8% vs.77.8%(P=0.69), 18.5% vs. 13.6%(P=0.66), and 10.2% vs. 10.4%(P=0.82), respectively. In multivariate analysis, donor BM hypoplasia did not affect patient clinical outcomes after allo-HSCT. If patients have no other suitable donor, a donor with BM hypoplasia can be used for patients receiving allo-HSCT if the donor Complete Blood Count and other examinations are normal.     

Utility of routine evaluation of sterility of cellular therapy products with or without extensive manipulation: Best practices and clinical significance

Background

We analyzed the results of routine sterility testing performed in our center over the last 10 years, in the context both hematopoietic stem cell transplantation (HSCT) and Advanced Therapeutic Medicinal Products (ATMPs).

Muscle flaps in the management of vascular grafts in contaminated wounds: an experimental study in dogs

This study evaluates in an animal model the efficacy of muscle flaps in protecting the fabric vascular prosthesis when placed in contaminated wounds. A total of 20 adult mongrel dogs received a 2-cm interpositional polytetrafluoroethylene (PTFE) graft to each femoral artery at the groin level. During the surgical procedure, the wounds were inoculated with a Staphylococcus aureus suspension containing either 1 x 10(4) or 1 x 10(5) organisms per milliliter. In half the animals, the grafts were wrapped with a distally based sartorius muscle flap before a standard two-layer closure was completed. One month after the surgery, all the animals were sacrificed and quantitative cultures were performed of the grafts and wounds. The muscle flaps were capable of protecting the vascular prosthesis with inoculums up to 1 x 10(4) organisms (p less than 0.05), but at greater bacterial contamination their efficacy was no longer significant.     

Corneal transplantation: study of the data of a regional eye bank for the year 2013 and analysis of the evolution of the adverse events reported in France since 2010

To analyze the data of the adverse events collected in a single major eye bank (EFS Bourgogne Franche Comté, Besançon, France) for the year 2013 and to report the French data of biovigilance provided by the French National Agency for Medicines and Health Products Safety (ANSM) between 2010 and 2013. we have set up a study of adverse events in 2013, in collaboration with a single eye bank (EFS Bourgogne Franche Comté, Besançon, France). A survey was sent to the surgeon for each delivered corneal button by the eye bank in 2013. They were asked for each grafted patient performed in their center, the type of graft (penetrating keratoplasty, anterior keratoplasty or endothelial keratoplasty), the occurrence of adverse events (primary failure, infectious keratis, endophthalmitis, immune rejection, and other events) and the time interval between surgery and events (Less than 1 postoperative month, between 1 month and 1 year postoperatively, >1 year postoperatively). In 2013, 407 corneal buttons were delivered by the eye bank of Besançon in 21 medical centers which performed corneal grafts and we sent 407 surveys. We received 243 completed questionnaires (59.75%) from 11 centers (52.38%). The global reported rate of adverse events was 27.54% of the graft (n = 65/236 corneal grafts performed in 11 centers in 2013; 20% of Primary graft failure, 11% of infectious keratitis, 1% of endophthalmitis, 34% of rejection, 34% of other incidents). 30.16% of complications were noticed before the first month after surgery versus 52.38% of complications noticed between the first month and the first year after surgery and 17.46% of complications noticed after the post-operative first year The most common causes of adverse events after PK were Immune rejection (13.17%), surgical causes (5.98%) and infection (4.79%) and after EK were Primary graft failure (8.2%) and surgical causes (19.67%). In 2013, in France 0.83% of adverse events were notified in ANSM. For the 236 performed graft issued from a major eye bank (EFS Besançon) in 2013 the global reported rate of post-graft adverse events was 27.54% of the grafts (20% of Primary graft failure, 11% of infectious keratitis, 1% of endophthalmitis, 34% of rejection and 34% of other incidents). Compared to the ANSM data (0.83% of adverse events reported in 2013) this rate is high. This difference can be explained by the low rate of annual notification to the ANSM and shows that biovigilance in France must be more developed. Since biovigilance needs constant improvement for the safety of the graft system, training, information for practitioners, simplifications of procedures and international standardization of the definition are the main points that could be improved.     

Comparative phylogenetic analysis of microbial communities in pristine and hydrocarbon-contaminated Alpine soils

A molecular characterization of pristine and petroleum hydrocarbon-contaminated Alpine soils sampled in Tyrol (Austria) was performed. To identify predominant bacteria, PCR-amplified 16S rRNA gene fragments from five pristine and nine contaminated soils were analysed using denaturing gradient gel electrophoresis (DGGE). Sequencing and phylogenetic analyses demonstrated that the majority of the DGGE bands represented bacteria in the Actinobacteria and Proteobacteria phyla: 18 and 73%, respectively, in pristine soils, compared with 20 and 76%, respectively, in contaminated soils. A different distribution pattern of bacterial classes in the Proteobacteria was observed between pristine and contaminated soils. The relative proportion of microorganisms belonging to the Alphaproteobacteria was larger in pristine (46%) than in contaminated (24%) soils, while Betaproteobacteria and Gammaproteobacteria were detected only in the hydrocarbon-contaminated soils. This result compared favourably with earlier work in which hydrocarbon-degradation genotypes, largely pseudomonads and Acinetobacter, belonging to the Gammaproteobacteria, were enriched following oil hydrocarbon contamination. In contrast, members of the Actinobacteria phylum, represented by Rhodococcus and Mycobacterium, were found in pristine soils where contamination events had not occurred. The results demonstrate a significant shift in the microbial community structure in Alpine soils following contamination. Furthermore, more potentially novel phylotypes were found in the pristine soils than in the contaminated soils.     

Human Adipose-Derived Mesenchymal Stem Cells in Cell Therapy: Safety and Feasibility in Different "Hospital Exemption" Clinical Applications

Based on immunomodulatory, osteogenic, and pro-angiogenic properties of adipose-derived stem cells (ASCs), this study aims to assess the safety and efficacy of ASC-derived cell therapies for clinical indications. Two autologous ASC-derived products were proposed to 17 patients who had not experienced any success with conventional therapies: (1) a scaffold-free osteogenic three-dimensional graft for the treatment of bone non-union and (2) a biological dressing for dermal reconstruction of non-healing chronic wounds. Safety was studied using the quality control of the final product (genetic stability, microbiological/mycoplasma/endotoxin contamination) and the in vivo evaluation of adverse events after transplantation. Feasibility was assessed by the ability to reproducibly obtain the final ASC-based product with specific characteristics, the time necessary for graft manufacturing, the capacity to produce enough material to treat the lesion, the surgical handling of the graft, and the ability to manufacture the graft in line with hospital exemption regulations. For 16 patients (one patient did not undergo grafting because of spontaneous bone healing), in-process controls found no microbiological/mycoplasma/endotoxin contamination, no obvious deleterious genomic anomalies, and optimal ASC purity. Each type of graft was reproducibly obtained without significant delay for implantation and surgical handling was always according to the surgical procedure and the implantation site. No serious adverse events were noted for up to 54 months. We demonstrated that autologous ASC transplantation can be considered a safe and feasible therapy tool for extreme clinical indications of ASC properties and physiopathology of disease.     

Adverse events after infusions of cryopreserved hematopoietic stem cells depend on non-mononuclear cells in the infused suspension and patient age

BACKGROUND: Adverse events (AE) represent a significant clinical problem after infusion of cryopreserved HPC. However, the factors playing a role in the pathogenesis have not yet been fully established. METHODS: We prospectively collected data on AE that occurred with 179 HPC infusions performed on patients affected with hematologic neoplasm after high-dose chemotherapy. The stem cell source was hemopoietic progenitor cells aphaeresis (HPC-A) in 157 cases and hemopoietic progenitor cell BM (HPC-BM) in 22 cases. In all cases, an endotoxin-free DMSO was used. RESULTS: One or more AE were registered in 51/179 infusions (28.6%). The frequency of AE was higher after HPC-A than after HPC-BM (31.3% vs. 4.5%; chi(2) test, P =0.008). With univariate logistic regression, other factors found important for AE were age (P =0.028), number of total nucleated cells infused per kilogram (P =0.002), volume per kilogram infused (P =0.057), volume of packed RBC (P =0.019), a content of non-mononuclear cells >0.5 x 10(8)/kg (

0.5 x 10(8)/kg (P =0.0003) remained significant. A significant correlation existed between reduction of cardiac frequency both with volume per kilogram infused (r =0.221, P =0.02) and actual time of infusion (r =0.269, P =0.005). DISCUSSION: Cardiovascular changes are influenced by volume per kilogram infused and by actual time of infusion, while non-cardiovascular AE are dependent on patient age and contamination by non-mononuclear cells in apheretic harvests.     

Flow cytometric determination of ploidy and proliferative activity on isolated bone marrow particles and on total bone marrow aspirate

The nuclear DNA content distribution of peripheral blood (PB) and bone marrow (BM) cells was determined by propidium iodide flow cytometry in 33 patients who underwent BM aspiration for diagnostic purposes. Two types of BM samples were taken during every aspiration procedure: whole BM aspirate, composed of BM particles contaminated by PB cells; isolated BM particles. Proliferative activity was calculated as the percentage of cells with DNA content intermediate between the diploid (2n) and the tetraploid (4n) values (2n-4n%). Ploidy was expressed as the ratio between the modal channel of the G0-G1 peak of the probe and that of an internal reference standard (DNA index, DI). The 2n-4n% was very close to zero in all PB samples. It was significantly greater in BM particles (21.2 +/- 6.6%) than in whole BM aspirate (16.6 +/- 5.5%, p less than .0005), with a close correlation (r2 = 66; p less than .0001) between the two values. Aneuploid stem lines were found in BM but not in PB. The DI of BM stem lines were similar in whole BM aspirate and BM particles, but the percentage of aneuploid cells was usually higher in BM particles. The reduced proliferative activity and the lower percent of aneuploid cells found in whole BM aspirates, with respect to BM particles, can be attributed to the contamination of BM tissue by PB, which had a very low proliferative activity and did not show aneuploidy. BM particles are therefore an easily obtained and reliable sample for routine evaluation of proliferative activity and ploidy of BM cells by DNA flow cytometry.     

Post‐marketing observational study on 5% intravenous immunoglobulin therapy in patients with secondary immunodeficiency and recurrent serious bacterial infections

Secondary hypogammaglobulinemia is one of the factors responsible for the increased susceptibility to infection in patients with chronic lymphocytic leukemia (CLL). This study assessed the therapeutic results, concomitant medication and tolerance of administering 5% intravenous immunoglobulin, secondary immunodeficiency and recurrent serious bacterial infections. A single center, post‐marketing, observational clinical study was performed on 10 patients with a variety of hematological malignancies (CLL, follicular non‐Hodgkin lymphoma, IgM‐secreting immunocytoma, IgA plasmacytoma and myelodysplastic syndrome/non‐Hodgkin lymphoma) who had been infused with IVIG from June 1994 to May 2009. The clinical benefit of IVIG was assessed by comparing the incidence of bacterial infections before and after starting this therapy. Plasma immunoglobulin concentrations and relevant hematological variables were recorded. For safety assessment, adverse events were monitored. The standard IVIG dosage was approximately 0.35 g/kg body weight every 3–4 weeks. Most patients had normal IgG trough values of >600 mg/dL during the IVIG treatment period. The rate of bacterial infections was reduced from 2.4 per patient in the 3 months before IVIG to 0.7 (0–1.5) per patient per year during IVIG treatment. All patients received concomitant medication, mainly anticancer and anti‐anemia therapy (100%). No serious adverse events related to IVIG were observed. The frequency of at least one minor adverse reaction was 1.44% (8/556 infusions). In conclusion, the investigated IVIG preparation was well tolerated and clinically beneficial in reducing the long term rate of serious bacterial infections in patients receiving concomitant treatment for malignant diseases.     

经桡动脉脑血管造影及术后血管封堵术对患者疗效及安全性观察

目的:探讨经桡动脉脑血管造影(transradial angiography,TRA)及术后血管封堵术对患者疗效及安全性。方法:选取我院2019年1月-2019年10月收治的193例行脑血管造影及术后血管封堵术的患者作为研究对象,将其随机分为TRA组(n=97例)和经股动脉途径(Transfemoral approach,TFA)组(n=96例)。观察两组穿刺成功率、术后3 d主要终点事件发生率、穿刺时间、术后住院时间、手术时间、受线时间、材料费、穿刺点局部并发症等。结果:TRA组穿刺成功率为98.97%,TFA组穿刺成功率为97.91%,两组对比无统计学意义(P>0.05);TRA组的穿刺时间长于TFA组、术后住院时间少于TFA组,差异有统计学意义(P<0.05);TRA组的受线时间、手术时间及材料费显著低于TFA组,有统计学意义(P<0.05);两组术后3 d主要终点事件发生率比较无统计学意义(P>0.05);TRA组穿刺点血肿及穿刺点并发症发生率较TFA组明显降低,差异有统计学意义(P<0.05),且无其他并发症情况发生。结论:经桡动脉脑血管造影(TRA)及术后血管封堵术具有局部穿刺点并发症发生率低、术后住院时间短、费用低、可以提高患者的舒适度等特点,更为安全有效,具有一定的临床优势。     

Gram-negative bacteria influence on the ability of the arginine-vasotocin to stimulate osmotic permeability of the frog urinary bladder epithelium

The influence of endogenous gram-negative bacteria colonizing the mucosal epithelium of frog Rana temporaria L. urinary bladders (FUB) on arginine-vasotocin AVT-stimulated osmotic water flow in isolated urinary bladders was investigated. 170 animals were examined and only 40% were contaminated with gram-negative bacteria (about 10(3)-10(6) CFU per hemibladder). Several Enterobacteriaceae species were identified (Hafnia alvei, 36.7%, E. coli, 32.3%, Serratia marcescens, 8.8%, Citrobacter freundii, 4.4% etc.). Basal osmotic water flow level was invariable in "clean" and contaminated FUB, whereas bacterial contamination resulted in considerable decrease in AVT-stimulated water flow ("clean": 2.53 +/- 0.13, n = 59, contaminated: 1.21 +/- 0.17 me/min/cm2, n = 38, p < 0.001, within first 15 min of incubation with 5 x 10(-10)M AVT). Gentamycin protection assay revealed predominantly adhesive forms of bacteria. Thus our data indicated that the presence of gram-negative bacteria colonizing the mucosal epithelium of the urinary bladder results in decreased adility of ADH to rise osmotic water permeability which in turn could impair body osmoregulation.     

Characterization and quantification of bacterial pathogens and indicator organisms inhousehold kitchens with and without the use of a disinfectant cleaner

This two year study evaluated the prevalence of indicator bacteria and specific pathogens in10 'normal' kitchens in the United States. In Phase I, none of the kitchens wascleaned with an antimicrobial cleaner or disinfectant. Eight locations within the kitchens weremonitored for: total heterotrophs, staphylococci, Pseudomonas , total coliforms andfaecal coliforms. Almost all locations at all households exhibited contamination, with the sink andsponge samples exhibiting large bacterial concentrations. The faecal coliform concentrations insink and sponge samples were very high, with 63 and 67% of all samples being positive,respectively. Escherichia coli was detected in 16·7% of all sink surfaces and33·3% of all sponges. Salmonella was detected once and Campylobacter , on two occasions. In a second phase, households were provided with an antimicrobialdisinfectant cleaner which families were encouraged to use but not forced to do so; in some cases,the product was used infrequently or not at all. This regimen did not demonstrate any consistentreduction in the incidence of bacterial contamination. By contrast, in the final phase of the studywhere disinfectant use was targeted for surfaces soon after contamination with foods or hands,the incidence of contamination decreased dramatically. These data show that normal kitchens caneasily be contaminated with a variety of bacterial contaminants including faecal coliforms, E.coli, Salmonella and Campylobacter . Irregular use, or not using antimicrobialagents, is unlikely to reduce the risk of these infectious agents. By contrast, targeted use is likelyto reduce the incidence of bacterial contaminants.     

Maintenance of the normal flora of human skin grafts transplanted to mice

Full-thickness human cadaver skin was maintained on the dorso-lateral thoracic region of hairless mice whose immune rejection mechanism was suppressed using anti-mouse-thymocyte globulin. The bacterial profile of the pregrafted skin did not differ significantly from the normal human microflora. In contrast, the murine skin exhibited quantitative and qualitative differences from the human flora, in particular by the complete absence of Propionibacterium acnes, the dominant bacterium on sebum-rich areas of human skin. The normal microbial profile of the human grafts was maintained throughout the experimental period despite the novel environmental milieu. There was little contamination of the grafts from the normal murine flora. It was concluded that the grafted human skin would provide a realistic model for studying the ecology of human cutaneous micro-organisms.     

Good manufacturing practice-compliant validation and preparation of BM cells for the therapy of acute myocardial infarction

BACKGROUND: Intracoronary application of BM-derived cells for the treatment of acute myocardial infarction (AMI) is currently being studied intensively. Simultaneously, strict legal requirements surround the production of cells for clinical studies. Thus good manufacturing practice (GMP)-compliant collection and preparation of BM for patients with AMI was established by the Cytonet group. METHODS: As well as fulfillment of standard GMP requirements, including a manufacturing license, validation of the preparation process and the final product was performed. Whole blood (n=6) and BM (n=3) validation samples were processed under GMP conditions by gelafundin or hydroxyethylstarch sedimentation in order to reduce erythrocytes/platelets and volume and to achieve specifications defined in advance. Special attention was paid to the free potassium (<6 mmol/L), some rheologically relevant cellular characteristics (hematocrit <0.45, platelets <450 x 10(6)/mL) and the sterility of the final product. RESULTS: The data were reviewed and GMP compliance was confirmed by the German authorities (Paul-Ehrlich Institute). Forty-five BM cell preparations for clinical use were carried out following the validated methodology and standards. Additionally three selections of CD34+ BM cells for infusion were performed. All specification limits were met. Discussion In conclusion, preparation of BM cells for intracoronary application is feasible under GMP conditions. As the results of sterility testing may not be available at the time of intracoronary application, the highest possible standards to avoid bacterial and other contaminations have to be applied. The increased expense of the GMP-compliant process can be justified by higher safety for patients and better control of the final product.