1/15. TCR V alpha- and V beta-gene segment use in T-cell subcultures derived from a type-III bare lymphocyte syndrome patient deficient in MHC class-II expression.Previously, we and others have shown that MHC class-II deficient humans have greatly reduced numbers of CD4 CD8- peripheral T cells. These type-III Bare Lymphocyte syndrome patients lack MHC class-II and have an impaired MHC class-I antigen expression. In this study, we analyzed the impact of the MHC class-II deficient environment on the TCR V-gene segment usage in this reduced CD4 CD8- T-cell subset. For these studies, we employed TcR V-region-specific monoclonal antibodies (mAbs) and a semiquantitative PCR technique with V alpha and V beta amplimers, specific for each of the most known V alpha- and V beta-gene region families. The results of our studies demonstrate that some of the V alpha-gene segments are used less frequent in the CD4 CD8- T-cell subset of the patient, whereas the majority of the TCR V alpha- and V beta-gene segments investigated were used with similar frequencies in both subsets in the type-III Bare Lymphocyte syndrome patient compared to healthy control family members. Interestingly, the frequency of TcR V alpha 12 transcripts was greatly diminished in the patient, both in the CD4 CD8- as well as in the CD4-CD8 compartment, whereas this gene segment could easily be detected in the healthy family controls. On the basis of the results obtained in this study, it is concluded that within the reduced CD4 CD8- T-cell subset of this patient, most of the TCR V-gene segments tested for are employed. However, a skewing in the usage frequency of some of the V alpha-gene segments toward the CD4-CD8 T-cell subset was noticeable in the MHC class-II deficient patient that differed from those observed in the healthy family controls.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
2/15. Adrenal toxicity in dogs and cats as a contributing cause of hormonal and immune destabilization.The adrenal cortex is regarded as the organ most vulnerable to toxicity within the endocrine system. The production of cortisol, among the many steroidal hormones produced by the cortex, may suffer as a result. In a veterinary clinical practice, household dogs and cats with a wide variety of diseases ranging from allergies to cancer commonly have a cortisol deficiency or defect that triggers endocrine imbalances and immune system destabilization. The causes of deficient cortisol are linked primarily to genetics but also to acquired adrenal damage likely stemming from environmental toxins. An innovative blood test to determine relevant endocrine-immune imbalances in pets and a treatment method based on low-dosage steroidal medication, as a form of cortisol replacement therapy, are described. Despite a prevailing reluctance to use steroidal medications long term because of the fear of side effects, extended and even life-time usage of these medications at low, physiologic dosages has been applied successfully for decades and appears to be gaining wider acceptance. The validity of a combined testing and treatment method for humans based on the veterinary model deserves investigation as a tool with which to identify and correct toxic damage to adrenal function.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
3/15. Disseminated mycobacterium avium infection in a 20-year-old female with partial recessive IFNgammaR1 deficiency.We report the case of a 20-year-old female with disseminated mycobacterium avium disease involving bones, lungs and brain. She was completely healthy up until the present illness and had been vaccinated with BCG in infancy without complications. Mycobacteriosis progressed in spite of treatment with antituberculous drugs and was controlled only after addition of interferon-gamma subcutaneously. A homozygous hypomorphic I87T mutation was found in the gene encoding the ligand-binding chain of the IFN-gamma receptor (IFNgammaR1). This mutation is the only known recessive hypomorphic lesion in IFNGR1 and had been reported before in only 1 child with curable BCG infection and his sibling with primary tuberculosis. Our report illustrates the clinical heterogeneity of patients sharing exactly the same form of partial recessive IFNgammaR1 deficiency. A diagnosis of partial recessive IFNgammaR1 deficiency should be contemplated in adults with unexplained environmental mycobacterial diseases.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
4/15. Thymic lymphocytes and thymic epithelial cells in 4 cases of congenital immunodeficiency.Congenital defects of predominantly cell-mediated immunity without other major defects or recognizable enzyme deficiency are classified "severe combined immunodeficiency" (SCID). Affected thymuses are severely reduced in size, microscopically they show only few lymphocytic cells and a cortico-medullary boundary is missing as well as Hassal's corpuscules. The primary defect is not yet clear. In this study 4 such cases were examined. The intrathymic epithelial cells showed expression of different cytokeratins and the typical strong positivity for the major histocompatibility complex. Lymphoid cells were phenotyped immunohistochemically and appeared as a very small population of cortical thymocytes, which was especially clear in a prenatally diagnosed and aborted fetus. His thymus, not altered by stress of infection or bone marrow transplantation, showed those few lymphocytes clustered around epithelial cells. The finding suggests an arrest in maturation and cell amplification rather than the absence of stem cells in the pathogenesis of SCID. Alterations in the thymic microenvironment could not be revealed by our methods.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
5/15. Chemical sensitivity in physicians.By the nature of their work environment, physicians may be exposed to potentially toxic substances that can trigger chemical sensitivity. Nineteen physicians with chemical sensitivity were evaluated at the environmental health Center - Dallas regarding: type of specialty, history of chemical exposure, symptoms produced, food and water tolerance, immune parameters and double-blind chemical inhalation challenge. food and chemical sensitivities were demonstrated in these physicians by oral, intradermal and inhalation challenges. After treatment, fifteen of the nineteen physicians were able to resume medical practice. Potential sources of chemical exposure in medical environments are evaluated.- - - - - - - - - - ranking = 2keywords = environment (Clic here for more details about this article) |
6/15. Establishment of a human cutaneous T-cell lymphoma in C.B-17 SCID mice.Investigation into the immunobiology of cutaneous T-cell lymphomas (CTCL) would be facilitated by the development of a suitable experimental system. The recent use of mice with severe combined immune deficiency (SCID) as a vehicle to study the human immune system prompted us to try to establish CTCL in SCID mice. We found that a CD4 lymphocytic infiltrate characteristic of CTCL was maintained within patient skin grafts in place on natural killer cell depleted SCID mice for the month of observation. CTCL cells were not found outside the human skin graft. This chimeric model using SCID mice and patient lesional skin should provide a useful tool to characterize CTCL/skin microenvironmental interactions and to test new therapeutic approaches.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
7/15. Disseminated aspergillus terreus infection in immunocompromised hosts.aspergillus terreus is ubiquitous in the environment but has rarely been found to be pathogenic. When recovered from clinical specimens, it is commonly considered a saprophyte. We report two cases of fatal disseminated A. terreus infection. The first patient was receiving corticosteroid therapy for immune thrombocytopenia when the condition developed, and the second patient was receiving immunosuppressive therapy after bone marrow transplantation for myelodysplasia. We also describe the frequency of recovery of A. terreus in our laboratory. The serious pathogenic potential of A. terreus in immunocompromised hosts should be recognized.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
8/15. Epstein-Barr virus-associated B-cell proliferations of diverse clonal origins after bone marrow transplantation in a 12-year-old patient with severe combined immunodeficiency.A 12-year-old boy with severe combined immunodeficiency who had been kept in a gnotobiotic environment since birth received bone marrow from a histoincompatible sibling in an attempt to reconstitute immunologic function. To prevent graft versus host disease, the donor's marrow was treated in vitro with monoclonal antibody and complement to remove alloreactive T cells. Eighty days after transplantation, the patient had a systemic illness characterized by fever, thrombocytopenia, gastrointestinal pain, and bleeding; he died on the 124th post-transplantation day. Postmortem examination revealed multiple tumor-like B-cell proliferations, recipient in origin, in numerous organs. Epstein-Barr virus (EBV) was isolated from the patient's pharyngeal secretions; EBV nuclear antigen was found in spontaneously transformed peripheral-blood lymphocytes, inflammatory cells from peritoneal fluid, and bone marrow cells; and EBV genomes were discovered in all tumor tissues. The donor's serum showed evidence of past EBV infection. Analysis of cellular immunoglobulin and immunoglobulin gene dna from the tumors indicated both monoclonal and oligoclonal B-cell proliferations. These findings provide evidence for the evolution of EBV-induced polyclonal activation of B cells to oligoclonal B-cell proliferation and finally to monoclonal B-cell lymphoma.- - - - - - - - - - ranking = 1keywords = environment (Clic here for more details about this article) |
9/15. Children reared in a reverse isolation environment: effects on cognitive and emotional development.Cognitive and emotional aspects of development in four infants reared in a reverse isolation environment because of congenital severe combined immunodeficiency disease were studied by psychological test performance and formal observation. The children were studied while they were inpatients and following their discharge after successful medical treatment was accomplished. Treatment time in reverse isolation varied from 10 to 52 months. Deficient self-generated activity, including motor and motor-based cognitive skills such as expressive language, were observed in two of the four children. Deficits were also observed to be at least moderately reversible either upon discharge or in relation to an inpatient intervention program. Case material is discussed with reference to severe disruption of oral feeding experience, quality of parental involvement, and sensory isolation inherent in the environment.- - - - - - - - - - ranking = 6keywords = environment (Clic here for more details about this article) |
10/15. Nine-year microflora study of an isolator-maintained immunodeficient child.A male child, maintained in a controlled environment, was monitored each month for bacteria, yeasts, and filamentous fungi recovered from the mouth, nasal passages, feces, and nine body surface sites. Three natural microbial categories became apparent. Incident microorganisms were recovered from within the isolator but did not establish permanent residence. Of the 53 incident types isolated, 20 were filamentous fungi and 4 were yeasts. Some genera, such as fusobacterium, lactobacillus, neisseria, and Rothia, which were commonly found in the reference group, did not become permanent inhabitants. Transient microorganisms were repeatedly recovered but could not be demonstrated within the isolated environment at the end of the study. The loss of only a few of the 19 transient species could be associated with antimicrobial therapy. Permanent microorganisms consisted of Pencillium citrinum and 17 bacterial types, of which alpha-hemolytic streptococci, staphylococcus edpidermidis subgroups II and V, micrococcus groups 1 and 2, clostridium bifermentans, and propionibacterium acnes were recovered throughout the entire 9 years of the study. The number of CFUs recovered from each sample type was generally not unlike that from the reference group of healthy male adults. Also, the number of different aerobic species recovered from the feces was within the normal range of that of the reference group. In contrast, the number of different species recovered from all other samples was less than that commonly found in the reference group.- - - - - - - - - - ranking = 2keywords = environment (Clic here for more details about this article) |
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