Erythema multiforme after orf virus infection: a report of two cases and literature review.

Orf virus has a worldwide distribution among sheep and goats. The hypersensitivity reaction erythema multiforme (EM) is a known complication of orf infection in humans; however, its occurrence is poorly understood and has not been extensively reviewed. We present two unrelated cases of orf-associated EM, and a review of the literature, highlighting important clinical, epidemiological and immunological aspects of this condition. Orf and its associated complications can occur in rural areas, as well as urban settings, where it is less well-known, through religious or cultural practices involving animal slaughter. Obtaining a history of animal exposures from patients with lesions suspicious for orf and secondary skin eruptions can guide diagnosis and identification of the inciting immune stimulus. Determining the pathophysiology and relative contribution of host and viral factors contributing to EM and other orf-associated hypersensitivity reactions could facilitate the identification of risk factors and inform treatment decisions.

Hip joint replacement surgery for idiopathic osteoarthritis aggregates in families.

In order to determine whether there is a genetic component to hip or knee joint failure due to idiopathic osteoarthritis (OA), we invited patients (probands) undergoing hip or knee arthroplasty for management of idiopathic OA to provide detailed family histories regarding the prevalence of idiopathic OA requiring joint replacement in their siblings. We also invited their spouses to provide detailed family histories about their siblings to serve as a control group. In the probands, we confirmed the diagnosis of idiopathic OA using American College of Rheumatology criteria. The cohorts included the siblings of 635 probands undergoing total hip replacement, the siblings of 486 probands undergoing total knee replacement, and the siblings of 787 spouses. We compared the prevalence of arthroplasty for idiopathic OA among the siblings of the probands with that among the siblings of the spouses, and we used logistic regression to identify independent risk factors for hip and knee arthroplasty in the siblings. Familial aggregation for hip arthroplasty, but not for knee arthroplasty, was observed after controlling for age and sex, suggesting a genetic contribution to end-stage hip OA but not to end-stage knee OA. We conclude that attempts to identify genes that predispose to idiopathic OA resulting in joint failure are more likely to be successful in patients with hip OA than in those with knee OA.

Genetic testing and genetic counseling for deafness: the future is here.

Today, genetic testing is an option for individuals who have deafness and hard-of-hearing conditions (D/HOH) and their families for diagnosis and carrier detection. As more and more D/HOH genes are identified, genetic testing will become commonplace. However, genetic testing is different from other tests that physicians commonly order and therefore should be conducted differently. The objective of this study was to determine the best manner in which to conduct genetic testing for individuals who have D/HOH. Numerous studies have shown that pretest and post-test genetic counseling is beneficial for patients and families undergoing genetic testing for a variety of conditions. The need for counseling was emphasized by our recently completed study in which we found that the majority of individuals whose children had genetic testing for D/HOH had a poor understanding of many genetic issues concerning recurrence risks for D/HOH and the meaning of the test results. We think that genetic counseling should be an integral part of genetic testing for individuals who have D/HOH.

Parental attitudes toward genetic testing for pediatric deafness.

Recent molecular genetic advances have resulted in genetic testing becoming an option for deaf individuals and their families. However, there is little information about the interest in such testing. To investigate this issue, parents with normal hearing who have one or more deaf children were surveyed about their attitudes toward diagnostic, carrier, and prenatal genetic testing for deafness. This population was chosen because it represents the majority of individuals who are encountered in clinical practice, given that 90%-95% of deaf individuals are born to persons with normal hearing. Of 328 surveys distributed, 96 were completed and returned. Of the respondents, 96% recorded a positive attitude toward genetic testing for deafness, including prenatal testing, although none would use this information to terminate an affected pregnancy. All respondents had a poor understanding of genetics, with 98% both incorrectly estimating the recurrence risk of deafness and misunderstanding the concept of inheritance. Notably, these findings were similar in the group who had had genetic testing for their children and in the group who had not, suggesting either that the parents who received genetic testing did not receive genetic counseling or that the counseling was not effective. On the basis of these results, it was concluded that this population is interested in the use of genetic testing and that testing should not be done without first providing formal genetic counseling. Appropriate counseling can help parents to understand the risks, benefits, and limitations of genetic testing.

Survey of veterinary conference attendees for evidence of zoonotic infection by feline retroviruses.

OBJECTIVE: To examine exposure risks, possibility of zoonosis, and potential disease associations for feline retroviruses among a group of occupationally exposed individuals. DESIGN: Unlinked voluntary cross-sectional epidemiologic survey. SAMPLE POPULATION: 204 veterinarians, laboratory scientists, and other occupationally exposed individuals who attended a veterinary conference on feline geriatric medicine. PROCEDURE: Blood was collected from participants who also completed a 13-question survey requesting demographic, occupational, exposure, and health information. Blood specimens were fractionated into plasma and mononuclear cell components. Plasma was tested for antibodies against feline immunodeficiency virus (FIV) and feline foamy virus (FeFV), as well as p27 antigen of FeLV. Mononuclear cell lysates were tested for FeLV provirus. RESULTS: Subjects reported extensive duration of work with cats (mean, 17.3 years) and multiple high-risk exposures (eg, cat bites, scratches, and injuries with sharp instruments) per year. However, neither serologic nor molecular evidence of zoonosis with any of the 3 feline retroviruses was detected. CONCLUSIONS AND CLINICAL RELEVANCE: Veterinarians encounter occupational exposures to animal material that place them at high risk for zoonoses. For feline retroviruses, the risk of zoonosis among healthy adult humans appears to be extremely small. However, potential for retroviral zoonosis, especially for viruses such as FeLV and FeFV that can replicate in human cells, cannot be eliminated, and universal precautions to reduce potential exposures should be used when handling sick cats.

Recommendations for Telephone Counseling.

Telephone counseling can provide a convenient, accessible, and valuable source of information to the general public, health care providers, and other professionals. In the genetic counseling profession, telephone counseling is often associated with teratogen information services. However, genetic counselors routinely utilize the telephone in a number of different counseling encounters. Nevertheless, the literature provides very little guidance to how that encounter might be conducted, what information should be obtained and provided, or how the encounter should be documented. We present a brief overview of the history of telephone counseling, a description of the major differences between telephone counseling and a face-to-face counseling session, and a framework to optimize a telephone counseling session.

Persistent zoonotic infection of a human with simian foamy virus in the absence of an intact orf-2 accessory gene.

Although foamy viruses (FVs) are endemic among nonhuman primates, FV infection among humans is rare. Recently, simian foamy virus (SFV) infection was reported in 4 of 231 individuals occupationally exposed to primates (1.8%). Secondary transmission to spouses has not been seen, suggesting that while FV is readily zoonotic, humans may represent dead-end hosts. Among different simian species, SFV demonstrates significant sequence diversity within the U3 region of the long terminal repeat (LTR) and 3' accessory open reading frames (ORFs). To examine if persistent human SFV infection and apparent lack of secondary transmission are associated with genetic adaptations in FV regulatory regions, we conducted sequence analysis of the LTR, internal promoter, ORF-1, and ORF-2 on a tissue culture isolate and peripheral blood mononuclear cell samples from a human infected with SFV of African green monkey origin (SFV-3). Compared to the prototype SFV-3 sequence, the LTR, internal promoter, and FV transactivator (ORF-1) showed sequence conservation, suggesting that FV zoonosis is not dependent on host-specific adaptation to these transcriptionally important regions. However, ORF-2 contains a number of deleterious mutations predicted to result in premature termination of protein synthesis. ORF-2 codes in part for the 60-kDa Bet fusion protein, proposed to be involved in the establishment of persistent cellular SFV infections. These results suggest that persistent human infection by SFV and reduced transmissibility may be influenced by the absence of a functional ORF-2.

Development and validation of a Western immunoblot assay for detection of antibodies to porcine endogenous retrovirus.

BACKGROUND: Reports that pig endogenous retrovirus (PERV) infects human cells in vitro have heightened the importance of molecular and serologic monitoring of xenograft recipients for evidence of infection with PERV. We report the development and validation of a PERV-specific Western immunoblot assay for the diagnostic testing of porcine xenografts recipients. This assay is based upon the serological cross-reactivity observed between PERV variants capable of infecting human cells in vitro and other mammalian C type retroviruses. METHODS AND RESULTS: Strong reactivity between PERV expressing embryonic pig kidney PK-15 cells and antisera raised against whole virus preparations of murine leukemia virus, gibbon ape leukemia virus (GALV), and simian sarcoma-associated virus was demonstrated by an immunofluorescence assay, suggesting specific antigenic cross-reactivity between this group of viruses and PERV. Western immunoblot analysis demonstrated that anti-GALV antisera reacted with three proteins in PK-15 cells having molecular masses of 30, 55, and 66 kDa. Antisera specific for the Gag proteins of either GALV or simian sarcoma-associated virus reacted with the 30-kDa (major) and 55-kDa (minor) proteins present in PK-15 cells and in PERV-infected 293 human kidney cells, likely representing reactivity to the processed and precursor forms of the PERV Gag protein, respectively. No reactivity was seen in uninfected 293 cells. Analysis of plasma samples from 200 United States blood donors and from 58 human immunodeficiency virus-1, 18 human immunodeficiency virus-2, 13 human T-cell lymphotrophic virus-I, 21 human T-cell lymphotrophic virus-II, and 15 cytomegalovirus infected controls were negative. CONCLUSIONS: As this assay is based on PERV antigen derived from infected human cells, it clearly has the capacity to detect a serologic response towards PERV variants that have zoonotic potential and will allow for the accurate determination of PERV-specific seroreactivity in porcine xenograft recipients.

Chromosomal abnormalities: trisomy 18, trisomy 13, deletions, and microdeletions.

The birth of an infant with a chromosomal abnormality such as trisomy 18, 13, Wolf-Hirschhorn (4p-) syndrome, Cri-du-chat (5p-) syndrome, and the microdeletion syndromes creates a stressful and devastating experience for families. Many of these disorders have severe consequences encompassing major malformations and mental retardation. With increasing diagnostic accuracy, clinicians can now appreciate the wide variability and natural history of these disorders. Although many of these infants do not survive the neonatal period, others do. Neonatal nurses have the opportunity to assist families in these situations by providing anticipatory guidance and care.

Xenotransplantation and the risk of retroviral zoonosis.

It is hypothesized that xenotransplantation could facilitate the emergence of new human pathogens. Retroviruses might pose the greatest public health risk because of the possibility of undetected transmission within a population. Evidence from naturally occurring retroviral zoonoses and cross-species infections by animal retroviruses provides a basis for reasoned speculation on the risks posed by xenotransplantation.

Regional proteoglycan synthesis in the sclera of experimentally myopic chicks.

Proteoglycan distribution and synthesis were compared in the sclera of normal and 10-day-form-vision-deprived (myopic) chick eyes using immunocytochemical, biochemical and autoradiographic techniques. Immunostaining with specific antibodies indicated that decorin is present in both the fibrous and cartilaginous layers of chick sclera, while aggrecan localizes only to the cartilaginous layer. For biochemical analyses of proteoglycan synthesis, sclera were isolated from control and 10-day-form-vision-deprived eyes and radiolabeled in organ culture with 35SO4. Proteoglycan synthesis was significantly increased only within a 6.5-mm-diameter button from the posterior pole of deprived eyes (+113%, P = 0.04), while no significant differences were detected in anterior and equatorial regions of control and deprived eyes. Chromatographic analyses of newly synthesized proteoglycans indicated that form-deprivation stimulates the synthesis of a large chondroitin/keratan sulfate proteoglycan (+77.47%), eluting at the position of aggrecan, as well as smaller chondroitin sulfate and keratan sulfate proteoglycans (+91.05%), which coelute with decorin. Autoradiographic analysis of incorporated sulfate indicated that the increase in proteoglycan synthesis observed in the posterior pole of deprived eyes occurs only in the cartilaginous scleral layer. The distribution of incorporated 35SO4, present over the cartilaginous layer of deprived sclera indicates that proteoglycan synthesis is lowest in scleral cartilage adjacent to the choroid and higher in interstitial regions of posterior cartilaginous sclera as well as in regions near the outer fibrous perichondrium. These results suggest that form-deprivation induced scleral growth in chicks can be attributed to growth and differentiation of scleral cartilage in the posterior pole.

Visual deprivation upregulates extracellular matrix synthesis by chick scleral chondrocytes.

PURPOSE: To characterize the cellular events responsible for the exaggerated ocular growth associated with experimental myopia in chicks, the accumulation and synthesis of proteoglycans and collagen were measured in the posterior sclera of control and form vision-deprived chick eyes. METHODS: Buttons (10 mm) from the posterior sclera of control and deprived eyes were used for biochemical measurements of glycosaminoglycans and hydroxyproline to estimate proteoglycan and collagen accumulation, respectively. The synthesis of proteoglycan, collagen, total protein, and RNA were measured in cultures of scleral chondrocytes isolated from posterior scleral buttons of control and deprived eyes by measuring the specific incorporation of 35SO4, [3H]proline, [35S]methionine, and [5-3H]uridine, respectively. The relative rate of aggrecan precursor protein synthesis was measured in cultures of control and deprived chondrocytes using immunoprecipitation assays. RESULTS: Form deprivation resulted in increased accumulation of proteoglycans but not collagen within the posterior sclera. In contrast, chondrocytes isolated from the posterior sclera of form-deprived eyes maintained elevated rates compared with controls of proteoglycan synthesis (+143%) and collagen synthesis (155%), as well as total protein synthesis (115%) and total RNA synthesis (44%). Because total protein synthesis was higher in cultures of deprived chondrocytes, the rate of aggrecan precursor protein synthesis, relative to total protein synthesis, was similar for both populations of cells. Pretreatment of scleral chondrocytes with actinomycin D, an inhibitor of RNA synthesis, resulted in a 112% increase in the rate of proteoglycan synthesis by control chondrocytes, but had no significant effect on the rate of proteoglycan synthesis by chondrocytes isolated from form-deprived eyes. CONCLUSIONS: Because proteoglycans accumulate within the posterior sclera of deprived eyes to a greater extent than collagen, yet form deprivation stimulates the synthesis of collagen and total protein as well as proteoglycans, these data suggest that collagen, and perhaps other scleral components, are selectively remodeled within the posterior sclera during the process of ocular elongation. Furthermore, experiments with actinomycin D suggest that the general upregulation observed in form-deprived chondrocytes may be due to the absence of a inhibitor normally present under conditions of form vision.

Molecular characterization and rescue of acatalasemic mutants of Drosophila melanogaster.

The enzyme catalase protects aerobic organisms from oxygen-free radical damage by converting hydrogen peroxide to molecular oxygen and water before it can decompose to form the highly reactive hydroxyl radical. Hydroxyl radicals are the most deleterious of the activated oxygen intermediates found in aerobic organisms. If formed, they can react with biological molecules in their proximity; the ensuing damage has been implicated in the increasing risk of disease and death associated with aging. To study further the regulation and role of catalase we have undertaken a molecular characterization of the Drosophila catalase gene and two potentially acatalasemic alleles. We have demonstrated that a previously existing allele, Catn4, likely contains a null mutation, a mutation which blocks normal translation of the encoded mRNA. The Catn1 mutation appears to cause a significant change in the protein sequence; however, it is unclear why this change leads to a nonfunctioning protein. Viability of these acatalasemic flies can be restored by transformation with the wild-type catalase gene; hence, we conclude that the lethality of these genotypes is due solely to the lack of catalase. The availability of flies with transformed catalase genes has allowed us to address the effect of catalase levels on aging in Drosophila. Though lack of catalase activity caused decreased viability and life span, increasing catalase activity above wild-type levels had no effect on normal life span.