Cross reaction pattern of 26 acrylic monomers on guinea pig skin

The cross reaction pattern of acrylic monomers was investigated in 20 groups of animals sensitized to a different acrylic monomer. Animals sensitized to one monoacrylate tend to react to other monoacrylates. Reactions to corresponding monomethacrylates (same alcohol group in the ester) or other monomethacrylates did not occur. Some reactions to di(meth)acrylates were observed. A number of animals sensitized to one monomethacrylate reacted to some other monomethacrylates and to monoacrylates. Reactions to di(meth)acrylates were observed. Animals sensitized to di(meth)acrylates showed hardly any positive cross reaction. A universal screening allergen to detect acrylic monomer sensitizations does not exist. The composition of (industrial) products should be made accessible to the occupational dermatologist in order to prevent the undesirable situation in which a patient suspected of having an acrylic monomer sensitization must be tested with a large series of potent allergens in order to detect the real origin of the sensitization.     

Detection of Salmonella typhi in the blood of patients with typhoid fever by polymerase chain reaction

A polymerase chain reaction (PCR)-based test was developed for the detection of Salmonella typhi in the blood specimens from patients with typhoid fever. Two pairs of oligonucleotide primers were designed to amplify a 343-bp fragment of the flagellin gene of S. typhi. Amplified products were analyzed by agarose gel electrophoresis and Southern blot hybridization by using a 32P-labeled 40-base probe internal to the amplified DNA. The nested PCR with two pairs of primers could detect 10 organisms of S. typhi as determined by serial dilutions of DNA from S. typhi. The peripheral mononuclear cells from 11 of 12 patients with typhoid fever confirmed by blood culture were positive for DNA fragment of the flagellin gene of S. typhi, whereas 10 blood specimens of patients with other febrile diseases were negative. With the nested PCR, S. typhi DNAs were detected from blood specimens of four patients with suspected typhoid fever on the basis of clinical features but with negative cultures. We suggest that the PCR technique could be used as a novel diagnostic method of typhoid fever, particularly in culture-negative cases.     

Expression of endogenous retroviruses in blood mononuclear cells and brain tissue from multiple sclerosis patients

To help clarify the complex association between negative childhood experiences and somatization, the authors examined the possible relationship between self-reported childhood sexual abuse, dysfunctional family background and several types of somatization in a nonclinical sample. Three anonymous questionnaires were completed by 202 female university students (average age 22 years). The findings confirm that severe or repeated childhood sexual victimization and a familial deficiency syndrome in childhood may be important in the pathogenesis of somatization.     

Directed inactivation of the psbI gene does not affect photosystem II in the cyanobacterium Synechocystis sp. PCC 6803

PsbI is a small, integral membrane protein component of photosystem II (PSII), a pigment-protein complex in cyanobacteria, algae and higher plants. To understand the function of this protein, we have isolated the psbI gene from the unicellular cyanobacterium Synechocystis sp. PCC 6803 and determined its nucleotide sequence. Using an antibiotic-resistance cartridge to disrupt and replace the psbI gene, we have created mutants of Synechocystis 6803 that lack the PsbI protein. Analysis of these mutants revealed that absence of the PsbI protein results in a 25-30% loss of PSII activity. However, other PSII polypeptides are present in near wild-type amounts, indicating that no significant destabilization of the PSII complex has occurred. These results contrast with recently reported data indicating that PsbI-deficient mutants of the eukaryotic alga Chlamydomonas reinhardtii are highly light-sensitive and have a significantly lower (80-90%) titer of the PSII complex. In Synechocystis 6803, PsbI-deficient cells appear to be slightly more photosensitive than wild-type cells, suggesting that this protein, while not essential for PSII biogenesis or function, plays a role in the optimization of PSII activity.     

Clinical results of the Mayo total ankle arthroplasty

Two hundred and four primary Mayo total ankle arthroplasties were performed in 179 patients at the Mayo Clinic from 1974 through 1988. We evaluated the clinical result after 160 arthroplasties in 143 patients who had been followed for two years or more (mean, nine years; range, two to seventeen years). The result was good for thirty-one ankles (19 per cent), fair for fifty-five (34 per cent), and poor for seventeen (11 per cent); fifty-seven arthroplasties (36 per cent) were considered to be a failure (defined as removal of the implant). Adequate preoperative and follow-up radiographs were available for 101 ankles (eighty-nine patients). There was radiographic evidence of loosening of eight tibial components (8 per cent) and fifty-eight talar components (57 per cent), but we found no association between the clinical and radiographic results. Complications occurred after nineteen (12 per cent) of the 160 arthroplasties, and ninety-four additional reoperations were necessary after sixty-six (41 per cent). On the basis of these findings, we do not recommend ankle arthroplasty with a constrained Mayo implant for rheumatoid arthritis or osteoarthrosis of the ankle.     

Pulmonary lymphocyte recruitment: depletion of CD8+ T cells does not impair the pulmonary immune response to intratracheal antigen

CD8+ T cells predominate in the lungs in hypersensitivity and human immunodeficiency virus-related lymphocytic pneumonitis, but their role in the immunopathogenesis of lung disease is unknown. We have shown that in immunized mice depleted of CD4+ T cells, CD8+ T cells are recruited into the lungs in response to intratracheal antigen challenge with sheep red blood cells (SRBC) (J. Clin. Invest. 1991; 88:1244-1254) or to pulmonary infection with Pneumocystis carinii (Am. J. Respir. Cell Mol. Biol. 1991; 5:186-197), suggesting that recruitment of CD8+ T cells does not depend on CD4+ T cell-derived signals. Because CD8+ T cells themselves produce a variety of chemotactic and immunoregulatory cytokines, CD8+ T cells may be important participants in, and modulators of, pulmonary immune responses. To test this hypothesis, we examined the effects of CD8+ T cell depletion on the generation of a pulmonary immune response in vivo. We monitored the recruitment of mononuclear cells into lungs in the absence of CD8-dependent signals and measured the duration of pulmonary inflammation in the absence of suppressor CD8+ T cells. Primed mice were treated with anti-CD8 monoclonal antibody to deplete CD8+ T cells and subsequently were challenged intratracheally with 5 x 10(8) SRBC. At various times after challenge, total and differential cell counts and lymphocyte phenotypes were measured in bronchoalveolar lavage fluid by flow cytometry and lungs were scored histologically. We found that depletion of CD8+ T cells neither decreased recruitment of immune and inflammatory cells nor prolonged the pulmonary immune response.(ABSTRACT TRUNCATED AT 250 WORDS)     

Somatic mosaicism in the central nervous system in spinocerebellar ataxia type 1 and Machado-Joseph disease

Glucocorticoids (GC) are widely used for anti-inflammatory and immunosuppressive therapy. Thirty to 50% of GC-treated patients develop osteoporosis. Potential mechanisms of GC-induced osteoporosis (GC-OP) include abnormalities in calcium balance, vitamin D metabolism, parathyroid hormone release and activity, prostaglandin E2 and cytokine synthesis, interference with c-fos and p-53 expression in osteoblasts, and hypogonadism. Early diagnosis and detection of patients at risk are accomplished with rapid, safe and non-invasive bone density measurements. Preventive measures include maintaining a positive calcium balance, vitamin D supplementation (if indicated) and treatment of hypogonadism. The shortest duration and the smallest doses possible of GC for a particular condition are advisable. For high-risk patients and those with established GC-OP calcitonin or bisphosphonate therapy is recommended.