Realtime physical simulator for virtual reality sailing by patients with spinal cord injury: an innovative voyage.

Background: The aim of this study was to explore whether sail training using a VSail® simulator would allow people with spinal cord injuries (SCI) to learn to sail in a safe controlled environment and then sail competently on the water in wind of moderate strength (12 knots). A battery of physical tests and questionnaires was used to evaluate possible improvements in health and well-being as a consequence of participation in the trial. Methods: Twenty participants were recruited with the assistance of their physicians from The International Center for Spinal Cord Injury, Kennedy Krieger Institute. Inclusion criteria were SCI >6 months previously, medically stable, with no recent (1 month or less) inpatient admission for acute medical or surgical issues. All neurological SCI levels (C1-S1) were eligible. All subjects followed a programme of instruction leading to mastery of basic sailing techniques (steering predetermined courses, sail trimming, tacking, gybing and mark rounding). Results: Not all participants completed the study for various reasons. Those that did were seven males and six females, six with tetraplegia and seven with paraplegia. The mean age was 45 years (23 to 63) and the average time since injury was 14.7 years (2 to 38 years). At the end of the course subjects were able to perform the sailing maneuvers and navigate a triangular racecourse on the simulator's display in 12 knots of wind within a pre-set time. At 6 weeks post completion of training most subjects showed a decrease in depression, physical and social limitations, and an improvement in physical tests. These improvements were maintained or increased in most participants by 12 weeks, but not others. Conclusions: The primary objective of the trial was achieved as all participants who completed the VSail® training were able to sail on the water at the Downtown Sailing Center in Baltimore.

Spinal cord injury can produce a variety of life-limiting chronic impairments, particularly as many occur in young adults. It affects the injured individual, their family, friends and society. Clinical care has improved substantially over the past decades allowing most with spinal injuries to have a normal life span. But many have difficulty in adjusting to the limitations of their new life and are often quite socially isolated. Sailing is usually considered out of reach to most people unless they have a connection through family or friends. It is generally viewed as elitist, expensive and at times dangerous. A view that probably stems from the publicity given to high profile events such as the Americas Cup or long-distance yachting competitions. However, small sailboat sailing is much more available. The problem for even able-bodied people is lack of access to an activity that does appear to carry some risks. For people with spinal injuries sailing seems even more daunting. The aim of this project is to investigate whether use of real time virtual sailing simulators can teach people with spinal cord injury to sail in a safe controlled environment and then easily transition to sail safely and competently on the water. In addition, this project was designed to evaluate the effects on physical and psychological health as well as effects on morale and self-esteem. The study recruited 20 people from the Kennedy Krieger Spinal Institute. They undertook a standard simulator training protocol involving 12 one-hour sessions. For mainly heath-related reasons not all participants completed these sessions. However, all of the 13 participants who completed the simulator training were able to sail in Hansa dinghies in Baltimore Harbor. Each individual showed improvement in most of the physical tests and in a Quality-of-Life Questionnaire and the Veterans RAND 36-Item Health Survey.

Trends in Pressure Injury Development in Patients With Lower Motor Neuron and Upper Motor Neuron Lesions: A Retrospective Descriptive Study.

BACKGROUND: Persons with spinal cord injury (SCI) are at high risk of pressure injury (PrI) development, but there is limited information about the effect of injury patterns (ie, upper motor neuron [UMN] or lower motor neuron [LMN] presentations) on PrI risk. PURPOSE: This study was conducted to explore the rate of PrI development in patients with LMN and UMN lesions. METHODS: A retrospective descriptive review of data from patients who were treated at a specialized outpatient SCI rehabilitation center in Baltimore, MD, between January 1, 2013, and December 31, 2019. Patients with neurological levels T8 and below, any type of SCI motor ability, and whose records were complete were included in the study. Data extracted included age, sex, date of injury, injury type, modified Ashworth Scale (MAS) score (ie, scale representing resistance to passive movement), date MAS was performed, body mass index, Spinal Cord Independent Measures-III, Braden Scale scores, ambulatory status, antispasticity medication, presence or history of PrI, and method of closure. Patients with a score of 0 on the MAS and without pharmacological management for spasticity were included in the LMN group, and patients with a score greater than 0 on the MAS with or without pharmacological management were included in the UMN group. Variables were compared using mean ± standard deviations, range, t-test, and Pearson's chi-squared and Fisher exact tests where appropriate. P values < .05 were considered statistically significant. RESULTS: Of the 602 records examined, 194 were complete and met inclusion criteria. Most patients (119, 61.34%) were male and classified in the UMN group (162, 84%). Mean age and time since injury were 35.20 ± 18.78 and 6.20 ± 7.62 years, respectively. Seventy-three (73) of 194 patients (37.6%) had, or had a history of, a PrI; 21 (66%) in the LMN and 52 (32%) in the UMN group (X21 = 12.8; P < .001). Statistically significant differences were noted between persons with LMN and UMN in terms of Braden Scale scores, age, body mass index, Spinal Cord Independent Measures-III, and time since injury. Compared with the UMN group, more patients in the LMN group had motor complete injuries with ISNCSCI levels A/B (P < .001)  and were nonambulatory (P < .001). CONCLUSION: The results of this study confirm that patients with SCI have a high rate of PrI development. The percentage of PrIs was significantly higher in the LMN than in the UMN group. Additional studies to examine the other variables that were significantly different between groups and their effect on PrI risk are needed.

Effects of drugs on bone metabolism in a cohort of individuals with traumatic spinal cord injury.

Study Design: This study is a retrospective review examining the prevalence of drugs commonly used in the management of spinal cord injury (SCI) which may influence bone health. Objective: The aim of our study was to examine the role commonly prescribed medications play in post-SCI bone health. Setting: We included all males 21 years of age and older who were evaluated over a 10-year period at an SCI-specialized center for a trauma-induced SCI. Method: We compared characteristics of individuals with normal bone mass to those with low bone mass according to their dual-energy X-ray absorptiometry (DXA) scan. Medication lists were reviewed for the presence of drugs considered to either positively or negatively affect bone metabolism. Results: Comparing individuals with normal bone mass (n = 68) to those with low bone mass (n = 211), only "Time after Injury" and "Level of Injury" were found to influence the likelihood of having low bone mass. Multivariate analysis failed to demonstrate significant associations between bone mass and the sum of drugs which either positively or negatively affect bone metabolism. When medications were reviewed individually, only bisphosphonates and anticonvulsants were found to be significantly associated with bone mass. Conclusions: Although 76% of our cohort was found to have low bone mass, the only major risk factors were "Time after Injury" and "Level of Injury". Anticonvulsant use was more common in individuals with low bone mass compared to those with normal bone mass. Given the retrospective methodology of this work, our findings underline associations that warrant further investigation.

Activity-Based Restorative Therapy and Skin Tears in Patients with Spinal Cord Injury.

OBJECTIVES: To determine the risk factors associated with skin tear development while participating in activity-based restorative therapy (ABRT), describe the possible consequences of skin tears incurred during therapy, and provide risk reduction strategies. METHODS: This was a retrospective review of electronic medical records from 2012 to 2015 in a spinal cord outpatient rehabilitation center; 21 of 54 patients who reported a wound at initial evaluation were diagnosed with skin tears. Nine of the 21 patients acquired skin tears during their course of ABRT. Of those 9, 7 were diagnosed with tetraplegia and 2 with paraplegia. All patients were treated by a wound care specialist 2 to 3 times per week while participating in therapy, with plan-of-care modifications to improve wound healing and maximize benefits of ABRT. MAIN OUTCOME MEASURES: Primary outcome measures were level of injury, International Standards for Neurological Classification of Spinal Cord Injury, age at initial evaluation, Spinal Cord Independence Measure, and International Skin Tear Advisory Panel skin tear classification. MAIN RESULTS: Six of 9 patients completed their full scheduled course of therapy with wounds closing within 30 days. Two patients' treatments were discontinued, and 1 patient was discharged because of exacerbation of a preexisting pressure injury. CONCLUSIONS: Skin tears can affect therapy by altering patient outcomes. Patient and clinician education, policy modifications, and risk management plans improved skin protection and prevented skin tears in this patient population. Only 2 subsequent cases of therapy-related skin tears were recorded in 2016.

Allergen homologs in the Euroglyphus maynei draft genome.

Euroglyphus maynei is a house dust mite commonly found in homes worldwide and is the source of allergens that sensitize and induce allergic reactions in humans. It is the source of species-specific allergens as well as allergens that are cross-reactive with the allergens from house dust mites Dermatophagoides farinae and D. pteronyssinus, and the ectoparasitic scabies mite Sarcoptes scabiei. The genomics, proteomics and molecular biology of E. maynei and its allergens have not been as extensively investigated as those of D. farinae, D. pteronyssinus, and S. scabiei where natural and recombinant allergens from these species have been characterized. Until now, little was known about the genome of E. maynei and it allergens but this information will be important for producing recombinant allergens for diagnostic and therapeutic purposes and for understanding the allergic response mechanism by immune effector cells that mediate the allergic reaction. We sequenced and assembled the 59 Mb E. maynei genome to aid the identification of homologs for known allergenic proteins. The predicted proteome shared orthologs with D. farinae and S. scabiei, and included proteins with homology to more than 30 different groups of allergens. However, the majority of allergen candidates could not be assigned as clear orthologs to known mite allergens. The genomic sequence data, predicted proteome, and allergen homologs identified from E. maynei provide insight into the relationships among astigmatid mites and their allergens, which should allow for the development of improved diagnostics and immunotherapy.

Identification of antigenic Sarcoptes scabiei proteins for use in a diagnostic test and of non-antigenic proteins that may be immunomodulatory.

BACKGROUND: Scabies, caused by the mite, Sarcoptes scabiei, infects millions of humans, and many wild and domestic mammals. Scabies mites burrow in the lower stratum corneum of the epidermis of the skin and are the source of substances that are antigenic or modulate aspects of the protective response of the host. Ordinary scabies is a difficult disease to diagnose. OBJECTIVE: The goal of this project was to identify S. scabiei proteins that may be candidate antigens for use in a diagnostic test or may be used by the mite to modulate the host's protective response. METHODS: An aqueous extract of S. scabiei was separated by 2-dimensional electrophoresis and proteins were identified by mass spectrometry. A parallel immunoblot was probed with serum from patients with ordinary scabies to identify IgM and/or IgG-binding antigens. The genes coding for 23 selected proteins were cloned into E. coli and the expressed recombinant proteins were screened with serum from patients with confirmed ordinary scabies. RESULTS: We identified 50 different proteins produced by S. scabiei, 34 of which were not previously identified, and determined that 66% were recognized by patient IgM and/or IgG. Fourteen proteins were screened for use in a diagnostic test but none possessed enough sensitivity and specificity to be useful. Six of the 9 proteins selected for the possibility that they may be immunomodulatory were not recognized by antibodies in patient serum. CONCLUSIONS: Thirty-three proteins that bound IgM and/or IgG from the serum of patients with ordinary scabies were identified. None of the 14 tested were useful for inclusion in a diagnostic test. The identities of 16 proteins that are not recognized as antigens by infected patients were also determined. These could be among the molecules that are responsible for this mite's ability to modulate its host's innate and adaptive immune responses.

A review of Sarcoptes scabiei: past, present and future.

The disease scabies is one of the earliest diseases of humans for which the cause was known. It is caused by the mite, Sarcoptes scabiei, that burrows in the epidermis of the skin of humans and many other mammals. This mite was previously known as Acarus scabiei DeGeer, 1778 before the genus Sarcoptes was established (Latreille 1802) and it became S. scabiei. Research during the last 40 years has tremendously increased insight into the mite's biology, parasite-host interactions, and the mechanisms it uses to evade the host's defenses. This review highlights some of the major advancements of our knowledge of the mite's biology, genome, proteome, and immunomodulating abilities all of which provide a basis for control of the disease. Advances toward the development of a diagnostic blood test to detect a scabies infection and a vaccine to protect susceptible populations from becoming infected, or at least limiting the transmission of the disease, are also presented.

Sarcoptes scabiei: genomics to proteomics to biology.

BACKGROUND: The common scabies mite, Sarcoptes scabiei is a cosmopolitan parasite of humans and other mammals. An annotated genome of Sarcoptes scabiei var. canis has been deposited in the National Center for Biotechnology Information (NCBI) and VectorBase and a proteomic analysis of proteins in extracts of mite bodies and eggs from this strain has been reported. Here we mined the data to identify predicted proteins that are known to be involved in specific biological processes in other animals. RESULTS: We identified predicted proteins that are associated with immunomodulation of the host defense system, and biological processes of the mite including oxygen procurement and aerobic respiration, oxidative metabolism, sensory reception and locating a host, neuronal transmission, stressors (heat shock proteins), molting, movement, nutrient procurement and digestion, and excretion and water balance. We used these data to speculate that certain biological processes may occur in scabies mites. CONCLUSION: This analysis helps understand the biology of Sarcoptes scabiei var. canis and adds to the data already available in NCBI and VectorBase.

A Proteomic Analysis of Sarcoptes scabiei (Acari: Sarcoptidae).

The pruritic skin disease scabies is caused by the burrowing of the itch mite Sarcoptes scabiei (De Geer). It is difficult to diagnose this disease because its symptoms often resemble those of other skin diseases. No reliable blood or molecular diagnostic test is available. The aim of this project was to begin to characterize the scabies proteome to identify scabies mite proteins, including those that may be useful in the development of a diagnostic test or vaccine. Various scabies mite extracts were separated by two-dimensional electrophoresis, and 844 Coomassie Blue-stained protein spots were excised, subjected to trypsin digestion, and analyzed by Matrix Assisted Laser Desorption/Ionization Time-Of-Flight/Time-Of-Flight (MALDI-TOF/TOF) mass spectrometry (MS). Tryptic fragment sequences determined by MS were searched against the recently completed S. scabiei annotated genome, leading to the identification of >150 proteins. Only 10 proteins hit to previously identified scabies proteins including actin, tropomyosin, and several ABC transporters. Thirteen proteins had homology to dust mite allergens (members of groups 8, 10, 13, 17, 20, 25, and 28). Most other sequences showed some homology to proteins in other mites and ticks including homologs of calmodulin, calreticulin, lipocalin, and glutathione-S-transferase. These data will now allow the identification of the proteins to which scabies patients produce antibodies, including those that may be good candidates for inclusion in a diagnostic test and vaccine.

Draft genome of the scabies mite.

BACKGROUND: The disease scabies, caused by the ectoparasitic mite, Sarcoptes scabiei, causes significant morbidity in humans and other mammals worldwide. However, there is limited data available regarding the molecular basis of host specificity and host-parasite interactions. Therefore, we sought to produce a draft genome for S. scabiei and use this to identify molecular markers that will be useful for phylogenetic population studies and to identify candidate protein-coding genes that are critical to the unique biology of the parasite. METHODS: S. scabiei var. canis DNA was isolated from living mites and sequenced to ultra-deep coverage using paired-end technology. Sequence reads were assembled into gapped contigs using de Bruijn graph based algorithms. The assembled genome was examined for repetitive elements and gene annotation was performed using ab initio, and homology-based methods. RESULTS: The draft genome assembly was about 56.2 Mb and included a mitochondrial genome contig. The predicted proteome contained 10,644 proteins, ~67 % of which appear to have clear orthologs in other species. The genome also contained more than 140,000 simple sequence repeat loci that may be useful for population-level studies. The mitochondrial genome contained 13 protein coding loci and 20 transfer RNAs. Hundreds of candidate salivary gland protein genes were identified by comparing the scabies mite predicted proteome with sialoproteins and transcripts identified in ticks and other hematophagous arthropods. These include serpins, ferritins, reprolysins, apyrases and new members of the macrophage migration inhibitory factor (MIF) gene family. Numerous other genes coding for salivary proteins, metabolic enzymes, structural proteins, proteins that are potentially immune modulating, and vaccine candidates were identified. The genes encoding cysteine and serine protease paralogs as well as mu-type glutathione S-transferases are represented by gene clusters. S. scabiei possessed homologs for most of the 33 dust mite allergens. CONCLUSION: The draft genome is useful for advancing our understanding of the host-parasite interaction, the biology of the mite and its phylogenetic relationship to other Acari. The identification of antigen-producing genes, candidate immune modulating proteins and pathways, and genes responsible for acaricide resistance offers opportunities for developing new methods for diagnosing, treating and preventing this disease.

The Potential for a Blood Test for Scabies.

BACKGROUND: Scabies afflicts millions of people worldwide, but it is very difficult to diagnose by the usual skin scrape test, and a presumptive diagnosis is often made based on clinical signs such as rash and intense itch. A sensitive and specific blood test to detect scabies would allow a physician to quickly make a correct diagnosis. OBJECTIVE: Our objective was to profile the mite-specific antibodies present in the sera of patients with ordinary scabies. METHODS: Sera of 91 patients were screened for Ig, IgD, IgE, IgG and IgM antibodies to S. scabiei, as well as to the house dust mites Dermatophagoides farinae, D. pteronyssinus and Euroglyphus maynei. RESULTS: 45%, 27% and 2.2% of the patients had measurable amounts of mixed Ig, IgG and IgE that recognized scabies mite antigens. However, 73.6% of the scabies patients had serum IgM that recognized scabies proteins, and all except two of them also had IgM that recognized all of the three species of dust mites. No patient had serum antibody exclusively reactive to scabies mite antigens. CONCLUSIONS: Co-sensitization or cross-reactivity between antigens from scabies and house dust mites confounds developing a blood test for scabies.

Population Growth and Allergen Content of Cultured Euroglyphus maynei House Dust Mites.

BACKGROUND: The house dust mite, Euroglyphus maynei, occurs in homes worldwide and is an important source of many allergens. Many patients sensitive to Dermatophagoides farinae and D. pteronyssinus are also sensitive to E. maynei. Extracts to detect sensitivity to E. maynei and reagents to detect E. maynei allergens in the environment or in cultures are not readily available. Information for the culture of E. maynei and for the determination of allergen and endotoxin levels in cultures is limited. METHOD: We mass cultured E. maynei at 23 and 30°C and determined the population growth profiles from inoculation until cultures could be harvested for the production of extracts. We also developed an ELISA to measure Eur m 1 and Eur m 2 allergens using mouse monoclonal antibodies directed at cross-reacting epitopes of group 1 and group 2 allergens of D. farinae and D. pteronyssinus. RESULTS: The E. maynei populations grew exponentially at both 23 and 30°C; however, the cultures matured more rapidly at 23°C. The Eur m 1 and Eur m 2 allergen concentrations in culture extracts changed independently as the cultures grew and matured. At both temperatures, the Eur m 1 concentrations increased as the cultures matured, while the Eur m 2 concentrations did not. The endotoxin levels in these cultures were low. CONCLUSION: We report here that E. maynei can be cultured at 23 and 30°C. Monoclonal antibodies directed at cross-reacting epitopes on Dermatophagoides allergens can be used to measure the associated E. maynei allergen levels in these cultures.

Reproductive biology of Euroglyphus maynei with comparisons to Dermatophagoides farinae and D. pteronyssinus.

The reproductive biology of the house dust mite, Euroglyphus maynei, is not well studied. This mite is usually less common in homes than Dermatophagoides farinae and D. pteronyssinus. When it is present, it usually co-inhabits with the Dermatophagoides spp. and is more restricted in geographical distribution. In this study, the duration of the life cycle (egg to adult) at 23 and 30 °C at 75% relative humidity (RH) and fecundity at 23 °C and 75% RH were determined for E. maynei and the data were compared to similar data for D. farinae and D. pteronyssinus. Adults hatched from eggs after 28 days at 23 °C and 20 days at 30 °C. Females produced 1.4 eggs/day during a reproductive period of 24 days at 23 °C. Euroglyphus maynei has a shorter life cycle than D. farinae and D. pteronyssinus at 23 °C but a longer life cycle at 30 °C. Euroglyphus maynei has a shorter reproductive period and produces fewer eggs than both D. farinae and D. pteronyssinus.

Use of a virtual reality physical ride-on sailing simulator as a rehabilitation tool for recreational sports and community reintegration: a pilot study.

Participation in sailing by people with disabilities, particularly in small sailboats, is widely regarded as having positive outcomes on self-esteem and general health for the participants. However, a major hurdle for people with no previous experience of sailing, even by those without disabilities, is the perception that sailing is elitist, expensive, and dangerous. Real-time "ride-on" sailing simulators have the potential to bridge the gap between dry-land and on-the-water sailing. These provide a realistic, safe, and easily supervised medium in which nonsailors can easily and systematically learn the required skills before venturing out on the water. The authors report a 12-wk pilot therapeutic sailing program using the VSail-Access sailing simulation system followed by on-water experience. After completion of the training, all subjects demonstrated the ability to navigate a simple course around marker buoys (triangular configuration) on the computer screen, the ability to sail independently in winds of moderate strength (up to 14 knots) on water, and measurable improvements in their psychologic health. In addition, the subjects were able to participate in a sports activity with their respective family members and experienced a sense of optimism about their future.

Sarcoptes scabiei mites modulate gene expression in human skin equivalents.

The ectoparasitic mite, Sarcoptes scabiei that burrows in the epidermis of mammalian skin has a long co-evolution with its hosts. Phenotypic studies show that the mites have the ability to modulate cytokine secretion and expression of cell adhesion molecules in cells of the skin and other cells of the innate and adaptive immune systems that may assist the mites to survive in the skin. The purpose of this study was to identify genes in keratinocytes and fibroblasts in human skin equivalents (HSEs) that changed expression in response to the burrowing of live scabies mites. Overall, of the more than 25,800 genes measured, 189 genes were up-regulated >2-fold in response to scabies mite burrowing while 152 genes were down-regulated to the same degree. HSEs differentially expressed large numbers of genes that were related to host protective responses including those involved in immune response, defense response, cytokine activity, taxis, response to other organisms, and cell adhesion. Genes for the expression of interleukin-1α (IL-1α) precursor, IL-1ß, granulocyte/macrophage-colony stimulating factor (GM-CSF) precursor, and G-CSF precursor were up-regulated 2.8- to 7.4-fold, paralleling cytokine secretion profiles. A large number of genes involved in epithelium development and keratinization were also differentially expressed in response to live scabies mites. Thus, these skin cells are directly responding as expected in an inflammatory response to products of the mites and the disruption of the skin's protective barrier caused by burrowing. This suggests that in vivo the interplay among these skin cells and other cell types, including Langerhans cells, dendritic cells, lymphocytes and endothelial cells, is responsible for depressing the host's protective response allowing these mites to survive in the skin.

Proteins and endotoxin in house dust mite extracts modulate cytokine secretion and gene expression by dermal fibroblasts.

House dust mite extracts used for diagnostic tests and immunotherapy contain bioreactive molecules including proteins and endotoxin. These extracts can influence the cytokine secretion and adhesion molecule expression by cells in the skin and lung airways. The aim of this study was to determine the role of proteins and endotoxin in mite extracts in modulating gene expression and cytokine secretion by human dermal fibroblasts. Cultured normal human dermal fibroblasts were stimulated with whole mite extracts, mite extracts boiled to denature proteins, or mite extracts treated with polymyxin B to inactivate lipopolysaccharide. Gene expression and secretion of interleukin-6 (IL-6), IL-8, and monocyte chemoattractant protein-1 (MCP-1) were determined after 6 h of stimulation. Whole Dermatophagoides farinae, D. pteronyssinus and Euroglyphus maynei extracts induced dose-dependent IL-6 and IL-8 secretion. In addition, D. farinae and E. maynei induced secretion of MCP-1. Dermatophagoides farinae and E. maynei also induced parallel cytokine gene expression. Cells stimulated with boiled D. farinae extract showed moderate to marked reductions in IL-6 and IL-8 secretion. In contrast, boiled D. pteronyssinus and E. maynei extracts induced equal or greater cytokine secretions than untreated extracts. The stimulating properties were reduced for all three extracts following treatment with polymyxin B. Our data suggest that both endotoxin and proteins in mite extracts modulate the secretion of cytokines by dermal fibroblasts. The biological activities of D. farinae, D. pteronyssinus, and E. maynei extracts are not equivalent. There appears to be a lipopolysaccharide-binding protein in some mite extracts.

Population growth and allergen accumulation of Dermatophagoides farinae cultured at 20 and 25 °C.

House dust mites are cultured to obtain mite allergen material to produce allergen extracts (vaccines) for diagnostic tests, immunotherapy, and research purposes. Research laboratories and manufacturers have their own culturing protocols to grow these mites and these may vary between manufacturers and between research laboratories. The temperature at which mites are cultured may influence the allergen composition, allergen ratio of Der 1: Der 2 and endotoxin levels in the extracts produced from these cultured mites. In order to produce standardized and uniform extracts, across the industry and in various research laboratories, the influence of culture conditions must be understood. Here we determined how temperature affects mite population growth rates, dynamics of allergen production, Der f 1: Der f 2 ratio and endotoxin levels in extracts made from Dermatophagoides farinae mites cultured at 20 and 25 °C. We found that Der f 1 and Der f 2 accumulated exponentially in the cultures with Der f 1 accumulating faster than Der f 2. When the live mite populations peaked, the ratios for Der f 1: Der f 2 were 4.1 and 4.7 for cultures reared at 20 and 25 °C, respectively. Most of the Der f 1 and Der f 2 allergen in whole cultures is not in mite bodies and is lost when the mite material is washed. Thus, if the ratio of Der f 1 and Der f 2 is an important consideration for commercial and research extracts, then the temperature at which the mites are cultured and the collection procedure are important considerations.

Effect of stored product mite extracts on human dermal microvascular endothelial cells.

Stored product mites commonly occur in agricultural work environments and sometimes in homes in significant numbers. They are a source of allergens that sensitize and induce allergic reactions. This may include atopic dermatitis. The purpose of this investigation was to determine if the common species of storage mites are the sources of molecules that influence the function of human dermal microvascular endothelial cells that regulate the trafficking of inflammatory and immune cells into the dermis during allergic reactions and other skin diseases. Human dermal microvascular endothelial cells were challenged with varying doses of extracts of the storage mites Acarus siro L., Chortoglyphus arcuatus (Troupeau), Lepidoglyphus destructor (Schrank), or Tyrophagus putrescentiae (Schrank) and the secretion of cytokines and expression of adhesion molecules were measured. The role of endotoxin and protein in inducing these responses was evaluated. These stored product mite extracts induced secretion of interleukin-6, interleukin-8, monocyte chemotactic protein-1, and granulocyte/monocyte colony stimulating factor. Some of these effects were induced by protein present in the extracts, some were induced by endotoxin, and some were induced by other substances. C. arcuatus and T. putrescentiae extracts also down-regulated tumor necrosis factor a-induced vascular cell adhesion molecule-1 expression. Stored product mite extracts contain an assortment of molecules, including endotoxins and proteins, which modulate the expression of cell adhesion molecules and the secretion of cytokines by microvascular endothelial cells. These modulating properties varied among mite species indicating that each mite species has a unique set of molecules that is responsible for its activity.

Diet influences growth rates and allergen and endotoxin contents of cultured Dermatophagoides farinae and Dermatophagoides pteronyssinus house dust mites.

BACKGROUND: The house dust mites Dermatophagoides farinae and Dermatophagoides pteronyssinus are cultured to obtain material for the production of allergen extracts for research, diagnostic and immunotherapeutic purposes. METHODS: We cultured mites on two different diets that supported thriving populations and determined the population growth rates, dynamics of allergen accumulation, and endotoxin concentrations in extracts made from mites harvested from the cultures. RESULTS: D. farinae populations grew faster on a diet of rodent chow/yeast than on an egg/yeast diet but a larger peak population size was achieved on the egg/yeast diet. Diet influenced the dynamics of the production of groups 1 and 2 allergens and the group 1/2 ratios for both species. To population peak, Der f 1 was produced at a faster rate on the chow/yeast diet but greater amounts of Der f 1 were produced by mites grown on the egg/yeast diet. D. pteronyssinus populations grew faster and achieved greater density on the egg/yeast diet compared to the chow/yeast diet. D. pteronyssinus produced more Der p 1 than Der p 2 when grown on chow/yeast while more Der p 2 than Der p 1 was produced on egg/yeast. Endotoxin concentrations in extracts made from whole cultures for both species at maximum population density were very different in the two diets. Washing the mites resulted in the loss of up to 88% of the allergen. CONCLUSION: Mite-culturing diet directly effects population growth, the dynamics of allergen accumulation, the group 1/2 allergen ratio and the endotoxin contents in extracts of cultured house dust mites.