Systemic epigenome-wide association study of elk treponeme-associated hoof disease

Treponeme-associated hoof disease (TAHD) is an emerging disease of elk (Cervus canadensis) in the U.S. Pacific West. Because environmental epigenetics is the primary molecular process that mediates environmental factor impacts on a host organism and disease, the role of epigenetics in TAHD etiology was examined. The current study was designed to examine potential effects of TAHD on systemic epigenetic modifications in infected elk over a range of TAHD lesion severity. Leg tendons that contain predominantly fibroblast connective tissue cells were used to isolate fibroblast cells for epigenetic analysis in unaffected and TAHD-positive male and female Roosevelt and Rocky Mountain elk. Differential DNA methylation regions (DMRs) between the unaffected and TAHD-positive elk were identified for both female and male elk. The presence of TAHD was associated with alteration of the connective tissue cell epigenetics, and DMR associated genes identified. Therefore, the infected elk were found to have a systemic epigenetic alteration that was associated with the disease, despite pathology being generally limited to feet. If the elk germline epigenetics is altered then generational transmission of susceptibility to TAHD may impact subsequent generations through epigenetic inheritance. This first study of epigenetic changes associated with disease in elk suggests that TAHD promotes a systemic effect on the elk epigenetics which could exert health impacts on the elk.

Transmission and lesion progression of treponeme-associated hoof disease in captive elk (Cervus canadensis)

Treponeme-associated hoof disease (TAHD) is a debilitating disease of free-ranging elk (Cervus canadensis) in the northwestern U.S. While treponemes are associated with lesions, the etiology and transmissibility between elk are unknown. Our objective was to determine whether the disease can be environmentally transmitted to captive elk. Four individually housed treatment elk and 2 control elk were challenged with soil mixed with inoculum prepared from free-ranging elk hooves from TAHD-positive elk or autoclaved hooves from normal elk, respectively. The inoculum for each group was applied to the interdigital space and added to pre-existing soil in each pen. Eight challenges were conducted at 1-4-week intervals and lesion development was assessed during a 138-day challenge period that was followed by a 170-day monitoring period to document lesion progression. All treatment elk, but no control elk, developed gross and histologic lesions consistent with TAHD. Treponema phylotypes similar to those in bovine digital dermatitis in cattle were detected using 16S rRNA gene amplicon sequencing from lesions in all treatment elk, but no control elk, during the challenge period. Lesions progressed from ulcerations in the interdigital space to extensive ulceration and underrunning of the hoof capsule by 35 and 173 days following the initial inoculation, respectively. Lameness in treatment elk was correlated with lesion development (R = 0.702, p≤0.001), and activity of infected elk was reduced during the challenge (p≤0.001) and monitoring periods (p = 0.004). Body condition was significantly lower in treatment than control elk 168 days following the initial inoculation (p = 0.05) and at each individual elk's study endpoint (p = 0.006). Three of 4 treatment elk were euthanized when they reached humane endpoints, and one elk recovered. These results provide direct evidence that TAHD is a transmissible infectious disease in elk. As such, actions that reduce transmission risk can support disease management and prevention.

ABORTION AND NEONATAL MORTALITY DUE TO TOXOPLASMA GONDII IN BIGHORN SHEEP (OVIS CANADENSIS)

Low lamb recruitment can be an obstacle to bighorn sheep (Ovis canadensis) conservation and restoration. Causes of abortion and neonate loss in bighorn sheep, which may affect recruitment, are poorly understood. Toxoplasma gondii is a major cause of abortion and stillbirth in domestic small ruminants worldwide, but no reports exist documenting abortion or neonatal death in bighorn sheep attributable to toxoplasmosis. Between March 2019 and May 2021, eight fetal and neonatal bighorn lamb cadavers from four western US states (Idaho, Montana, Nebraska, and Washington) were submitted to the Washington Animal Disease Diagnostic Laboratory for postmortem examination, histologic examination, and ancillary testing to determine the cause of abortion or neonatal death. Necrotizing encephalitis characteristic of toxoplasmosis was identified histologically in six of eight cases, and T. gondii infection was confirmed by PCR in five cases with characteristic lesions. Other lesions attributable to toxoplasmosis were pneumonia (3/5 cases) and myocarditis (2/5 cases). Protozoal cysts were identified histologically within brain, lung, heart, skeletal muscle, adipose tissue, or a combination of samples in all five sheep with PCR-confirmed T. gondii infections. Seroprevalence of T. gondii ranged from 40-81% of adult females sampled in the Washington population in October and November 2018-2021, confirming high rates of exposure before detection of Toxoplasma abortions in this study. Of 1,149 bighorn sheep postmortem samples submitted to Washington Animal Disease Diagnostic Laboratory between January 2000 and May 2021, 21 of which were from fetuses or neonates, a single case of chronic toxoplasmosis was diagnosed in one adult ewe. Recent identification of Toxoplasma abortions in bighorn sheep suggests that toxoplasmosis is an underappreciated cause of reproductive loss. Abortions and neonatal mortalities should be investigated through postmortem and histologic examination, particularly in herds that are chronically small, demographically stagnant, or exhibit reproductive rates lower than expected.

Associations between hair trace mineral concentrations and the occurrence of treponeme-associated hoof disease in elk (Cervus canadensis)

BACKGROUND

Trace minerals are important for animal health. Mineral deficiency or excess can negatively affect immune function, wound healing, and hoof health in domestic livestock, but normal concentrations and health impairment associated with mineral imbalances in wild animals are poorly understood. Treponeme-associated hoof disease (TAHD) is an emerging disease of free-ranging elk (Cervus canadensis) in the U.S. Pacific Northwest. Selenium and copper levels identified in a small number of elk from areas where TAHD is established (i.e., southwestern Washington) suggested a mineral deficiency may have increased susceptibility to TAHD. Our objectives were to determine trace mineral concentrations using hair from elk originating in TAHD affected areas of Washington, California, Idaho, and Oregon and assess their associations with the occurrence of the disease.

RESULTS

We identified limited associations between TAHD occurrence and severity with hair mineral concentrations in 72 free-ranging elk, using Firth's logistic regression and multinomial regression models. We found consistent support for a priori hypotheses that selenium concentration, an important mineral for hoof health, is inversely associated with the occurrence of TAHD. Less consistent support was observed for effects of other minerals previously associated with hoof health (e.g., copper or zinc) or increased disease risk from potential toxicants.

CONCLUSION

Trace mineral analysis of hair is a non-invasive sampling technique that offers feasibility in storage and collection from live animals and carcasses. For some minerals, levels in hair correlate with visceral organs that are challenging to obtain. Our study using hair collected opportunistically from elk feet submitted for diagnostic investigations provides a modest reference of hair mineral levels in elk from the U.S. Pacific Northwest that may be useful in future determination of reference ranges. Although our results revealed high variability in mineral concentrations between elk, consistent relationship of possibly low selenium levels and TAHD suggest that further investigations are warranted.

Effective gene expression prediction from sequence by integrating long-range interactions

How noncoding DNA determines gene expression in different cell types is a major unsolved problem, and critical downstream applications in human genetics depend on improved solutions. Here, we report substantially improved gene expression prediction accuracy from DNA sequences through the use of a deep learning architecture, called Enformer, that is able to integrate information from long-range interactions (up to 100 kb away) in the genome. This improvement yielded more accurate variant effect predictions on gene expression for both natural genetic variants and saturation mutagenesis measured by massively parallel reporter assays. Furthermore, Enformer learned to predict enhancer-promoter interactions directly from the DNA sequence competitively with methods that take direct experimental data as input. We expect that these advances will enable more effective fine-mapping of human disease associations and provide a framework to interpret cis-regulatory evolution.

Vitronectin binding protein, BOM1093, confers serum resistance on Borrelia miyamotoi

Borrelia miyamotoi, a member of the tick-borne relapsing fever spirochetes, shows a serum-resistant phenotype in vitro. This ability of B. miyamotoi may contribute to bacterial evasion of the host innate immune system. To investigate the molecular mechanism of serum-resistance, we constructed a membrane protein-encoding gene library of B. miyamotoi using Borrelia garinii strain HT59G, which shows a transformable and serum-susceptible phenotype. By screening the library, we found that bom1093 and bom1515 of B. miyamotoi provided a serum-resistant phenotype to the recipient B. garinii. These B. miyamotoi genes are predicted to encode P35-like antigen genes and are conserved among relapsing fever borreliae. Functional analysis revealed that BOM1093 bound to serum vitronectin and that the C-terminal region of BOM1093 was involved in the vitronectin-binding property. Importantly, the B. garinii transformant was not serum-resistant when the C terminus-truncated BOM1093 was expressed. We also observed that the depletion of vitronectin from human serum enhances the bactericidal activity of BOM1093 expressing B. garinii, and the survival rate of BOM1093 expressing B. garinii in vitronectin-depleted serum is enhanced by the addition of purified vitronectin. Our data suggests that B. miyamotoi utilize BOM1093-mediated binding to vitronectin as a mechanism of serum resistance.

Accessory Tragus: A Rare Congenital Anomaly in a Dog

Accessory tragus is a congenital malformation of part of the external ear, commonly reported in humans. Clinically, it is a benign, cutaneous mass located anywhere between the tragus of the ear and the angle of the mouth, along the migratory path of the first branchial arch. An accessory tragus was diagnosed in an otherwise healthy six-month-old male castrated American pit bull terrier that had a haired, pedunculated cutaneous mass on the left maxillary region from birth. Histologically, the mass was a polypoid extension of histologically normal haired skin with a central core of subcutaneous adipose tissue and well-differentiated elastic cartilage. To the authors' knowledge, this is the first report of this lesion in a non-human species. Retrospective examination of records from 2008 to 2018 at the Washington Animal Disease Diagnostic Laboratory failed to identify any other case. As accessory tragus in humans is commonly linked with other congenital anomalies and syndromes, recognition of this lesion in animals may aid in early discovery of other congenital defects and inform adequate excision of the lesion to prevent chondrodermatitis.

Schwannosis in Three Foals and a Calf

Proliferation of ectopic Schwann cells within the central nervous system (CNS) parenchyma (schwannosis) in early life is most commonly associated with human neurofibromatosis type-2 and has been unrecognized in domestic animals. Three foals and a calf, 5 to 11 weeks old, with progressive neurological signs from birth were studied. Histologically, at multiple levels of the spinal cord, all animals had bilateral plaques of proliferative spindle cells, predominantly affecting the white matter adjacent to dorsal and ventral nerve roots and variably extending into the gray matter. Proliferating cells had strong intracytoplasmic immunoreactivity for the Schwann cell markers myelin protein zero and periaxin, highlighting the formation of peripheral nervous system (PNS) myelin within the spinal cord. In all cases, foci of disorganized neural tissue (glioneuronal hamartomas) were present, which in 2 cases formed a mass effect that resulted in syringohydromyelia. Neonatal presentation suggests a congenital maldevelopment of the nervous system, with spontaneous invasion of PNS-derived Schwann cells into the CNS.

A relapsing fever group Borrelia sp. is widely distributed among wild deer in Japan

A relapsing fever group Borrelia sp. was detected from the blood of wild deer (Cervus nippon) in Japan. The Borrelia sp. was distributed nationwide among deer with an overall prevalence of 26% in blood samples. The prevalence of infection was significantly higher in fawns (48.4%) compared to adult deer (23.6%). Sequencing analysis reveals that this Borrelia sp. belongs to the hard tick-borne relapsing fever borreliae, and that it forms a single lineage based on sequences of the flagellin and glycerophosphodiester phosphodiesterase genes. Borrelial genome copy number was estimated at 8.8 × 10³ genome copies/μl of blood. Other hard tick-borne relapsing fever borrelia (e.g. Borrelia miyamotoi) were not detected in deer blood in this study. These findings suggest that wild deer may act as reservoirs for this Borrelia sp. in Japan.

Suspected myelodysplastic/myeloproliferative neoplasm in a feline leukemia virus-negative cat

A 10-year-old castrated Domestic Short-Haired cat was presented to a primary care veterinarian for a wellness examination and laboratory examination for monitoring of diabetes mellitus. The CBC revealed marked thrombocytosis, leukopenia and macrocytic, normochromic anemia. The cat tested negative for FeLV and feline immunodeficiency virus, but was positive for Mycoplasma haemominutum by PCR. Hematologic abnormalities were not responsive to therapy, so a repeat CBC and a bone marrow aspiration for cytology were performed. Additional blood smear findings included anisocytosis with megaloblastic erythroid precursors, large platelets, eosinophilic myelocytes and metamyelocytes, and rare unidentified blasts. The bone marrow smear was highly cellular, and the cytologic pattern was consistent with myelodysplastic syndrome with an erythroid predominance. At that time, 15% blasts were present. The cat was treated with a vitamin K₂ analog, doxycycline, and prednisolone, but without a clinical response. Within 3 months, euthanasia was elected due to declining quality of life, and a necropsy was performed. Postmortem bone marrow smears were highly cellular and dominated by monomorphic blasts of unknown line of origin (52%), persistent marked erythroid and megakaryocytic dysplasia, and ineffective erythropoiesis and granulopoiesis. Immunohistochemical, immunocytochemical, and cytochemical stains resulted in a diagnosis of acute myeloid leukemia of unclassified type. Additional histologic findings included mixed hepatitis with trematode infestation and lymphoplasmacytic interstitial nephritis with fibrosis. The marked thrombocytosis with myelodysplastic syndrome and the FeLV-negative status of this cat were unusual. The difficulty in classifying the myelodysplasia and subsequent leukemia highlights a need for further reporting and characterization of these types of disease.

Four Cases of Spontaneous Neoplasia in the Naked Mole-Rat (Heterocephalus glaber), A Putative Cancer-Resistant Species

The naked mole-rat (Heterocephalus glaber) is widely acclaimed to be cancer-resistant and of considerable research interest based on a paucity of reports of neoplasia in this species. We have, however, encountered four spontaneous cases of neoplasia and one presumptive case of neoplasia through routine necropsy and biopsy of individuals in a zoo collection of nonhybrid naked mole-rats bred from a single pair. One case each of metastasizing hepatocellular carcinoma, nephroblastoma (Wilms' tumor), and multicentric lymphosarcoma, as well as presumptive esophageal adenocarcinoma (Barrett's esophagus-like) was identified postmortem among 37 nonautolyzed necropsy submissions of naked mole-rats over 1-year-old that were submitted for necropsy between 1998 and August 2015. One incidental case of cutaneous hemangioma was also identified antemortem by skin biopsy from one naked mole-rat examined for trauma.

Spinal Cord Hamartomatous Myelodysplasia in 2 Horses With Clinical Neurologic Deficits

Two horses euthanized for neurologic deficits were diagnosed with hamartomatous myelodysplasia of the spinal cord. One was a 5-week-old Holsteiner colt exhibiting spasms of muscle rigidity in the extensor muscles of the limbs and epaxial muscles, and the other was a 3-year-old Thoroughbred colt exhibiting progressive ataxia and hypermetria in the pelvic limbs. Each had focal disorganization of the white and gray matter of the spinal cord forming a mass interspersed with neurons, glial cells, and disoriented axon bundles. In the Holsteiner colt, the mass was at the level of C5 and included islands of meningeal tissue contiguous with the leptomeninges. The mass occluded the central canal forming hydromyelia cranial to the occlusion. In the Thoroughbred colt, the mass was at the level of L1 on the dorsal periphery of the spinal cord and did not involve the central canal.

Audioprofile Surfaces: The 21st Century Audiogram

OBJECTIVE

To present audiometric data in 3 dimensions by considering age as an addition dimension.

METHODS

Audioprofile surfaces (APSs) were fitted to a set of audiograms by plotting each measurement of an audiogram as an independent point in 3 dimensions with the x, y, and z axes representing frequency, hearing loss in dB, and age, respectively.

RESULTS

Using the Java-based APS viewer as a standalone application, APSs were pre-computed for 34 loci. By selecting APSs for the appropriate genetic locus, a clinician can compare this APS-generated average surface to a specific patient's audiogram.

CONCLUSION

Audioprofile surfaces provide an easily interpreted visual representation of a person's hearing acuity relative to others with the same genetic cause of hearing loss. Audioprofile surfaces will support the generation and testing of sophisticated hypotheses to further refine our understanding of the biology of hearing.

Multiple-locus variable-number tandem repeat analysis of Leptospira interrogans and Leptospira borgpetersenii isolated from small feral and wild mammals in East Asia

Leptospira spp. are the causative agents of a worldwide zoonosis, leptospirosis, maintained by various mammals. Each Leptospira serovar is frequently associated with a particular maintenance host, and recently, Leptospira genotype-host association has also been suggested to limit serovars to restricted areas. We investigated the molecular characteristics of L. interrogans and L. borgpetersenii which were isolated from small feral and wild animals in four East Asian states using multiple-locus variable-number tandem repeat analysis (MLVA). MLVA using 11 loci was performed on 110 L. interrogans serogroups from Japan (79 strains of 5 serogroups from 3 animal species), Philippines (21; 3; 2), Taiwan (7; 2; 3), and Vietnam (3; 1; 1). A MLVA method using 4 loci for L. borgpetersenii was established and performed on 52 isolates from Japan (26; 3; 7), Philippines (13; 1; 2), and Taiwan (13; 1; 3). In L. interrogans, serogroups Autumnalis and Hebdomadis appeared more genetically diverse than serogroups Bataviae, Grippotyphosa, Icterohaemorrhagiae, Pomona, or Pyrogenes. The former serogroup strains with the exception of one Hebdomadis strain were isolated from Apodemus speciosus while all the latter serogroup strains with the exception of Grippotyphosa were isolated from Rattus norvegicus. L. borgpetersenii was isolated from at least 11 animal species while L. interrogans was isolated from five species, which might suggest a wider host range for L. borgpetersenii. Broad host preference in a single genotype was also observed, which colonized not only different species of the same genera but also multiple animal genera. This study demonstrates that there may be variability in the range of genetic diversity among different Leptospira serogroups, which may be attributed to maintenance host animals and environmental factors.

Chordomas at High Prevalence in the Captive Population of the Endangered Perdido Key Beach Mouse (Peromyscus polionotus trissyllepsis)

The Perdido Key beach mouse (Peromyscus polionotus trissyllepsis) is a critically endangered subspecies of the oldfield mouse. The captive population, currently maintained by 3 Florida zoos, is entirely derived from just 3 wild-caught ancestor mice. Necropsy and histopathology revealed chordoma of the vertebral column in 38 of 88 (43%) mice. The tumors were locally expansile and invasive masses of large physaliferous (vacuolated) cells with small, round, hyperchromatic nuclei, similar to the "classic" form of chordomas described in humans. Primary tumors rarely contained small amounts of bone and cartilaginous matrix, characteristic of the "chondroid" form. Neoplastic cells contained abundant granules positive by the periodic acid-Schiff reaction. Brachyury and cytokeratin AE1/AE3 were detected in neoplastic cells by immunohistochemistry, but uncoupling protein 1 was not identified. Primary tumors occurred along the entire vertebral column--cervical, 5 of 38 (13%); thoracic, 16 (42%); lumbar, 13 (34%); and sacral, 10 (26%)--and 10 (26%) mice had multiple primary masses. Metastases to the lungs were noted in 13 of the 38 (34%) mice. Mice diagnosed with chordomas postmortem ranged from 424 to 2170 days old, with a mean of 1399 days. The prevalence of chordoma was not significantly different between males (n = 23 of 50; 46%) and females (n = 15 of 38; 39%).

Cordova: web-based management of genetic variation data

Cordova is an out-of-the-box solution for building and maintaining an online database of genetic variations integrated with pathogenicity prediction results from popular algorithms. Our primary motivation for developing this system is to aid researchers and clinician-scientists in determining the clinical significance of genetic variations. To achieve this goal, Cordova provides an interface to review and manually or computationally curate genetic variation data as well as share it for clinical diagnostics and the advancement of research.

AVAILABILITY AND IMPLEMENTATION

Cordova is open source under the MIT license and is freely available for download at https://github.com/clcg/cordova.

Advancing genetic testing for deafness with genomic technology

BACKGROUND

Non-syndromic hearing loss (NSHL) is the most common sensory impairment in humans. Until recently its extreme genetic heterogeneity precluded comprehensive genetic testing. Using a platform that couples targeted genomic enrichment (TGE) and massively parallel sequencing (MPS) to sequence all exons of all genes implicated in NSHL, we tested 100 persons with presumed genetic NSHL and in so doing established sequencing requirements for maximum sensitivity and defined MPS quality score metrics that obviate Sanger validation of variants.

METHODS

We examined DNA from 100 sequentially collected probands with presumed genetic NSHL without exclusions due to inheritance, previous genetic testing, or type of hearing loss. We performed TGE using post-capture multiplexing in variable pool sizes followed by Illumina sequencing. We developed a local Galaxy installation on a high performance computing cluster for bioinformatics analysis.

RESULTS

To obtain maximum variant sensitivity with this platform 3.2-6.3 million total mapped sequencing reads per sample were required. Quality score analysis showed that Sanger validation was not required for 95% of variants. Our overall diagnostic rate was 42%, but this varied by clinical features from 0% for persons with asymmetric hearing loss to 56% for persons with bilateral autosomal recessive NSHL.

CONCLUSIONS

These findings will direct the use of TGE and MPS strategies for genetic diagnosis for NSHL. Our diagnostic rate highlights the need for further research on genetic deafness focused on novel gene identification and an improved understanding of the role of non-exonic mutations. The unsolved families we have identified provide a valuable resource to address these areas.

Prioritization of retinal disease genes: an integrative approach

The discovery of novel disease-associated variations in genes is often a daunting task in highly heterogeneous disease classes. We seek a generalizable algorithm that integrates multiple publicly available genomic data sources in a machine-learning model for the prioritization of candidates identified in patients with retinal disease. To approach this problem, we generate a set of feature vectors from publicly available microarray, RNA-seq, and ChIP-seq datasets of biological relevance to retinal disease, to observe patterns in gene expression specificity among tissues of the body and the eye, in addition to photoreceptor-specific signals by the CRX transcription factor. Using these features, we describe a novel algorithm, positive and unlabeled learning for prioritization (PULP). This article compares several popular supervised learning techniques as the regression function for PULP. The results demonstrate a highly significant enrichment for previously characterized disease genes using a logistic regression method. Finally, a comparison of PULP with the popular gene prioritization tool ENDEAVOUR shows superior prioritization of retinal disease genes from previous studies. The java source code, compiled binary, assembled feature vectors, and instructions are available online at https://github.com/ahwagner/PULP.

AudioGene: predicting hearing loss genotypes from phenotypes to guide genetic screening

Autosomal dominant nonsyndromic hearing loss (ADNSHL) is a common and often progressive sensory deficit. ADNSHL displays a high degree of genetic heterogeneity and varying rates of progression. Accurate, comprehensive, and cost-effective genetic testing facilitates genetic counseling and provides valuable prognostic information to affected individuals. In this article, we describe the algorithm underlying AudioGene, a software system employing machine-learning techniques that utilizes phenotypic information derived from audiograms to predict the genetic cause of hearing loss in persons segregating ADNSHL. Our data show that AudioGene has an accuracy of 68% in predicting the causative gene within its top three predictions, as compared with 44% for a majority classifier. We also show that AudioGene remains effective for audiograms with high levels of clinical measurement noise. We identify audiometric outliers for each genetic locus and hypothesize that outliers may reflect modifying genetic effects. As personalized genomic medicine becomes more common, AudioGene will be increasingly useful as a phenotypic filter to assess pathogenicity of variants identified by massively parallel sequencing.

Differential tick burdens may explain differential Borrelia afzelii and Borrelia garinii infection rates among four, wild, rodent species in Hokkaido, Japan

The ecologies of Lyme disease Borrelia spp. are very specific to location, as they are dependent upon the spirochete species and genotypes, the vectors and the host vertebrates present. In Hokkaido, Japan, where two human pathogenic, Lyme disease Borrelia spp. are present, and human cases are reported annually, the ecologies have been poorly studied. Our goal was to determine whether variation in borrelial infection rates among rodent species sharing an environment, is due to immunological or ecological differences. To this end, we examined the relationships between tick burden and borrelial infection, by including examination of agreement between nested PCR, as a test for infection, and serology, as a test for exposure. We collected 868 rodents, comprised of four species commonly found in Hokkaido, and tested for infection rates with Borrelia spp. using PCR for the borrelial flaB gene, seroprevalence of Borrelia afzelii and Borrelia garinii using ELISA, and attachment of ticks by direct counts. We noted a correlation between differential nymph and larval burdens and the borrelial infection rates found among the four rodent species. Furthermore, there was significant correlation between infection and seroprevalence of B. afzelii and B. garinii (P<0.01), between infection and Ixodes persulcatus nymph burden (P<0.01), and between seroprevalence and I. persulcatus nymph burden (P<0.01). The close agreement among rodent species seroprevalences with infection rates and tick burdens suggest the differences in infection rates of Borrelia spp. may largely be a direct consequence of differential exposure to vectors.

Borrelia miyamotoi infections among wild rodents show age and month independence and correlation with Ixodes persulcatus larval attachment in Hokkaido, Japan

To clarify how Borrelia miyamotoi is maintained in the environment in Hokkaido, we examined Ixodes persulcatus for its prevalence among wild rodents and its tick vector by detecting a portion of the borrelial flaB gene in rodent urinary bladder and blood samples, and from whole ticks. We compared B. miyamotoi infection rates to Borrelia garinii and Borrelia afzelii, which are human Lyme disease pathogens also carried by wild rodents, and which are transmitted by the same vector tick. Whereas B. garinii and B. afzelii showed age dependence of infection rates among wild rodents (18.4% and 9.9% among adults and 6.0% and 3.4% among sub-adults, respectively) when looking at urinary bladder samples, B. miyamotoi infection rates were not age dependent for either blood (4.2% among adults, and 7.9% among sub-adults) or urinary bladder samples (1.0% among adults, and 1.7% among sub-adults). Moreover, while B. garinii and B. afzelii infection rates showed increases across months (June, July [p<0.05] and August [p<0.01] had higher rates than in May for adult rodents with B. garinii, and July and August had higher rates than in May [p<0.01] for adult rodents with B. afzelii), B. miyamotoi infection rates did not show significant month dependence. These differences in month and age dependence led us to suspect that B. miyamotoi may not develop persistent infections in wild rodents, as B. garinii and B. afzelii are thought to. Furthermore, we examined the extent of rodent exposure to I. persulcatus nymphs and larvae throughout most of the tick's active season (May through September), and determined that B. miyamotoi infection rates in sub-adult rodents were correlated with larval burden (p<0.01), suggesting that larvae may be very important in transmission of B. miyamotoi to wild rodents.

A novel relapsing fever Borrelia sp. infects the salivary glands of the molted hard tick, Amblyomma geoemydae

A novel relapsing fever Borrelia sp. was found in Amblyomma geoemydae in Japan. The novel Borrelia sp. was phylogenetically related to the hard (ixodid) tick-borne relapsing fever Borrelia spp. Borrelia miyamotoi and B. lonestari. The novel relapsing fever Borrelia sp. was detected in 39 A. geoemydae (39/274: 14.2%), of which 14 (14/274: 5.1%) were co-infected with the novel relapsing fever Borrelia sp. and Borrelia sp. tAG, one of the reptile-associated borreliae. Transstadial transmission of the novel relapsing fever Borrelia sp. occurred in the tick midgut and the salivary glands, although Borrelia sp. tAG was only detected in the tick midgut. The difference of the borrelial niche in molted ticks might be associated with borrelial characterization.

DFNA8/12 caused by TECTA mutations is the most identified subtype of nonsyndromic autosomal dominant hearing loss

The prevalence of DFNA8/DFNA12 (DFNA8/12), a type of autosomal dominant nonsyndromic hearing loss (ADNSHL), is unknown as comprehensive population-based genetic screening has not been conducted. We therefore completed unbiased screening for TECTA mutations in a Spanish cohort of 372 probands from ADNSHL families. Three additional families (Spanish, Belgian, and English) known to be linked to DFNA8/12 were also included in the screening. In an additional cohort of 835 American ADNSHL families, we preselected 73 probands for TECTA screening based on audiometric data. In aggregate, we identified 23 TECTA mutations in this process. Remarkably, 20 of these mutations are novel, more than doubling the number of reported TECTA ADNSHL mutations from 13 to 33. Mutations lie in all domains of the α-tectorin protein, including those for the first time identified in the entactin domain, as well as the vWFD1, vWFD2, and vWFD3 repeats, and the D1-D2 and TIL2 connectors. Although the majority are private mutations, four of them-p.Cys1036Tyr, p.Cys1837Gly, p.Thr1866Met, and p.Arg1890Cys-were observed in more than one unrelated family. For two of these mutations founder effects were also confirmed. Our data validate previously observed genotype-phenotype correlations in DFNA8/12 and introduce new correlations. Specifically, mutations in the N-terminal region of α-tectorin (entactin domain, vWFD1, and vWFD2) lead to mid-frequency NSHL, a phenotype previously associated only with mutations in the ZP domain. Collectively, our results indicate that DFNA8/12 hearing loss is a frequent type of ADNSHL.

Bringing Chemical Data onto the Semantic Web

Present chemical data storage methodologies place many restrictions on the use of the stored data. The absence of sufficient high-quality metadata prevents intelligent computer access to the data without human intervention. This creates barriers to the automation of data mining in activities such as quantitative structure-activity relationship modelling. The application of Semantic Web technologies to chemical data is shown to reduce these limitations. The use of unique identifiers and relationships (represented as uniform resource identifiers, URIs, and resource description framework, RDF) held in a triplestore provides for greater detail and flexibility in the sharing and storage of molecular structures and properties.

Patient mutations in doublecortin define a repeated tubulin-binding domain

Doublecortin (DCX) missense mutations are found in two clusters in patients with defective cortical neuronal migration. Although DCX can function as a microtubule-associated protein (MAP), the potential relationship between its MAP activity and neuronal migration is not understood. Here we show that the two clusters of patient mutations precisely define an internal tandem repeat. Each repeat alone binds tubulin, whereas neither repeat is sufficient for co-assembly with microtubules. The two tandem repeats are sufficient to mediate microtubule polymerization, and representative patient missense mutations lead to impaired polymerization both in vitro and in vivo as well as impaired microtubule stabilization. Furthermore, each repeat is predicted to have the secondary structure of a beta-grasp superfold motif, a motif not found in other MAPs. The patient mutations are predicted to disrupt the structure of the motif, suggesting that the motif may be critical for the DCX-tubulin interaction. These data provide both genetic and biochemical evidence that the interaction of DCX with microtubules is dependent upon this novel repeated tubulin-binding motif.

Survey of hepatitis B and C in addiction treatment unit

The survey on our unit revealed that 80% of injection drug users (IDUs) had hepatitis B core antibody (HBcAB), and 90% had hepatitis C virus antibody (HCVAB). Less than half of each group did not know or were unsure of the mode of transmission and spread of HCV. These findings emphasize the need to focus on education, especially about transmission of hepatitis B and C infection in drug addicts, particularly IDUs.

Percutaneous endoscopic recanalization of the catheter: a new technique of proximal shunt revision

OBJECTIVE

Proximal ventricular catheter obstruction by the choroid plexus is a frequent occurrence in children with shunted hydrocephalus. In some cases, the flow is obstructed owing to membranous occlusion by a small amount of tissue. It has been shown that only a few of the multiple catheter openings need be patent to maintain adequate shunt function. Recent advances in technology have improved our ability to perform intraluminal endoscopic catheter dissection and minimize the morbidity associated with shunt maintenance.

METHODS

Percutaneous endoscopic shunt recanalization was performed in 20 cases (18 children) under institutional review board study protocol. The mean age was 32 months, and all children had signs and symptoms of shunt malfunction, confirmed by computed tomography and magnetic resonance imaging and verified by shunt taps. Under aseptic conditions in the operating room, the Rickham reservoir was entered with a 16-gauge intravenous catheter, and the obstruction was visualized with a fiber endoscope (0.5-0.8 mm). Intraluminal dissection using electrocautery was performed with endoscopic guidance to visualize the catheter and flushing of the valve.

RESULTS

At a mean follow-up time of 20 months (range, 15-29 mo), the children are doing well, with computed tomographic and magnetic resonance imaging confirmation of adequate ventricular decompression in the 17 successful cases (85%). There were three failures in the study, necessitating a standard open shunt revision.

CONCLUSION

The percutaneous endoscopic shunt recanalization procedure can be used successfully to treat proximal shunt malfunction.

Aspects of calcium transport by the ovine placenta: studies based on the interplacentomal region of the chorion

An in vitro technique for the measurement of calcium uptake into the maternal-facing fetal chorionic membrane (apical trophoblast) was used to study the relationship between calcium uptake and stage of pregnancy in the sheep. The effects on calcium uptake of varying calcium concentration and temperature of the incubation medium, of adding calcium channel blockers or heavy metals (lanthanum and nickel) or calcium ionophore/agonist were also studied. The data indicate a saturable calcium uptake process, plateauing after 15 min incubation. This uptake remained constant throughout the last third of gestation until a significant fall in uptake was noted during the final week prior to parturition. This uptake was not due to extracellular cellular diffusion since there was no significant uptake of tritiated inulin over the same period in each case. Calcium uptake in this system was also shown to be a temperature dependent process which was abolished at temperatures of 0-4 degrees C. A decrease in calcium concentration to 0.12 mM in the incubation medium also caused a corresponding decrease in calcium uptake to 21 per cent of control (1.2 mM). The addition of the heavy metals lanthanum and nickel also significantly reduced calcium uptake as did the calcium channel blockers verapamil, metoprolol and diltiazem. The calcium channel ionophore A23187 increased calcium uptake into the material facing chorion. Although the interplacentomal chorion may not be representative of the whole of the placental unit, it clearly contains a specific calcium uptake process under local physiological control. The blocking of calcium uptake by the specific I-type calcium channel blocker verapamil may indicate the presence of I-type channels of unusually low sensitivity since the concentration needed to block them was much higher than would be required for excitable I-type channels in isolated cells.

Development of a litigaphobia scale: measurement of excessive fear of litigation

The present investigation was directed toward the development of a psychometrically sound instrument that would permit measurement and understanding of the phenomenon of litigaphobia. An initial item pool of 143 items was subjected to a Thurstone analysis. 47 items survived this screening for low ambiguity and uniform spread of tearfulness. These 47 items were administered to 123 physicians and psychologists in a six-point Likert format. The Kuder-Richardson-20 split-half analysis was .90. Next a series of factor analyses were performed. A main factor was identified as generalized litigaphobia and a second factor was labelled invulnerability to litigation. A Guttman scaling procedure for Factor I yielded a four-item scale with a reproducibility coefficient of .92.

Levels and temporal trends of trace element concentrations in vertebral bone

An X-ray fluorescence analysis study of iron, zinc, rubidium, strontium, and lead in ashed vertebral column whole bone samples of 51 sudden death victims in Western Australia gave median values of 893, 213, 25, 108, and 25 ppm, respectively. Highly significant concentration-age Spearman correlations were observed for iron-age (rs = 0.45, P less than .004), Zn-age (0.43, P less than .006), and lead-age (0.63, P less than .001), the mean per annum rates of increase being 26, 0.4, and 0.8 ppm, respectively, and marked concentration-concentration correlations were found for iron-lead (0.44, P less than .003) and strontium (0.30, P less than .06). The median zinc concentrations for the male and female subsets are 216 and 205 ppm, respectively; the corresponding values for strontium are 100 and 120 ppm.