Hair bleaching and skin burning

Hairdressing-related burns are preventable and therefore each case is one too many. We report a unique case of a 16-yr-old girl who suffered full-thickness chemical and thermal burns to the nape of her neck and superficial burns to the occiput after her hair had been dyed blond and placed under a dryer to accelerate the highlighting procedure. The wound on the nape of the neck required surgical debridement and skin grafting. The grafted area resulted in subsequent scar formation.

Obscurin modulates the assembly and organization of sarcomeres and the sarcoplasmic reticulum

Obscurin (approximately 800 kDa) in striated muscle closely surrounds sarcomeres at the level of the M-band and Z-disk where, we hypothesize, it participates in the assembly of the contractile apparatus and membrane systems required for Ca2+ homeostasis. In this study, we used small inhibitory RNA (siRNA) technology to reduce the levels of obscurin in primary cultures of skeletal myotubes to study its role in myofibrillogenesis and the organization of the sarcoplasmic reticulum (SR). siRNA-treated myotubes showed a specific and dramatic reduction in the approximately 800 kDa form of obscurin by reverse transcription-polymerase chain reaction, immunoblotting, and immunofluorescence. M-bands and A-bands, but not Z-disks or I-bands, were disrupted when the synthesis of obscurin was inhibited. Small ankyrin 1, an integral protein of the network SR that binds to obscurin, also failed to align around developing sarcomeres in treated myotubes. Myosin and myomesin levels were significantly reduced in treated myotubes but alpha-actinin was not, suggesting that down-regulation of obscurin destabilizes proteins of the M-band and A-band but not of the Z-disk. Our findings suggest that obscurin is required for the assembly of the M-band and A-band and for the regular alignment of the network SR around the contractile apparatus.

A new class of receptor for herpes simplex virus has heptad repeat motifs that are common to membrane fusion proteins

We isolated a human cDNA by expression cloning and characterized its gene product as a new human protein that enables entry and infection of herpes simplex virus (HSV). The gene, designated hfl-B5, encodes a type II cell surface membrane protein, B5, that is broadly expressed in human primary tissue and cell lines. It contains a high-scoring heptad repeat at the extracellular C terminus that is predicted to form an alpha-helix for coiled coils like those in cellular SNAREs or in some viral fusion proteins. A synthetic 30-mer peptide that has the same sequence as the heptad repeat alpha-helix blocks HSV infection of B5-expressing porcine cells and human HEp-2 cells. Transient expression of human B5 in HEp-2 cells results in increased polykarocyte formation even in the absence of viral proteins. The B5 protein fulfills all criteria as a receptor or coreceptor for HSV entry. Use by HSV of a human cellular receptor, such as B5, that contains putative membrane fusion domains provides an example where a pathogenic virus with broad tropism has usurped a widely expressed cellular protein to function in infection at events that lead to membrane fusion.

Clearance of lymphocytic choriomeningitis virus in antibody- and B-cell-deprived mice

The role of antibody in immune recovery from infection with lymphocytic choriomeningitis virus (LCMV) strain WE was evaluated in B-cell-depleted mice. Mice were treated from birth with either affinity-purified rabbit anti-mouse immunoglobulin M (IgM), normal rabbit immunoglobulin, or, alternatively, an affinity-purified monoclonal rat anti-mouse IgM antibody (LO-MM-9); untreated mice served as controls. B-cell depletion was considered complete in specifically treated mice according to the following criteria: absence of a significant response to the B-cell mitogen lipopolysaccharide, absence of B cells expressing immunoglobulin on their surfaces, absence of detectable IgM or IgG in serum, and presence in the serum of free anti-IgM antibodies. In organs of mu-suppressed BALB/c mice, LCMV-WE replicated, dependent upon organ, at the same rate or more rapidly and, in general, to higher titers than in normal rabbit immunoglobulin-treated mice; untreated mice eliminated the virus most rapidly and showed lower virus titers. In addition, LCMV-primed control mice cleared a second LCMV challenge very rapidly and contained no virus by day 3, whereas mu-suppressed mice had virus in their blood and organs (except the spleen) up to days 3 to 6. The observed effects of anti-mu treatment may reflect the action of neutralizing antibodies (which so far have been difficult to demonstrate in vivo) or other antibody-dependent antiviral mechanisms which, together with T cells, efficiently control LCMV clearance.

Anti-Listeria monocytogenes immunity in mu-suppressed mice: a comparison of treatment with conventional hyperimmune rabbit anti-mouse IgM and affinity-purified, monoclonal rat anti-mouse IgM

The capacity of anti-IgM treated, B-cell-depleted mice to control infection by Listeria monocytogenes was evaluated. Suppression was achieved with a hyperimmune rabbit anti-mouse-IgM antiserum (IRS), with affinity-purified IRS (IRP), or with an affinity-purified, monoclonal, rat anti-mouse-IgM antibody (LO-MM-9). B-cell depletion in specifically treated mice was judged to be complete by the following criteria: absence of significant response to a B-cell mitogen lipopolysaccharide, absence of B-cells with detectable IgM or kappa light chain on their surface, absence of detectable IgM, and presence of free anti-IgM antibodies in serum. BALB/c mice, conventionally treated from birth with IRS, had an increased capacity to clear L. monocytogenes from the blood during the first 5 min after intravenous infection. Furthermore, control of infection seemed to be enhanced during the first 24 h but was found to be impaired when assessed 3 and 4 days after initiation of infection. These effects were, however, not IRS specific, because control mice treated with normal rabbit serum behaved comparably. Mortality caused by 2 x 10(3) L. monocytogenes injected intraperitoneally into BALB/c mice susceptible to L. monocytogenes was increased more in NRS-than in IRS-treated mice when both were compared with untreated control mice. Therefore, chronic injection of IRS or NRS seemed to disturb anti-L. monocytogenes immunity, rendering an evaluation of the role of antibodies impossible.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment with high doses of anti-IgM prevents, but with lower doses accelerates autoimmune disease in (NZW x BXSB)F1 hybrid mice

We have treated autoimmune-prone (NZW x BXSB)F1 hybrid mice with polyclonal rabbit anti-mouse IgM antibodies starting from birth to define conditions leading to quantitative and functional elimination of the B cell compartment and to determine the effect of anti-IgM treatment on the development of autoimmune disease. A maintenance dose of anti-IgM antibodies (600 micrograms/wk), which efficiently induced B cell depletion in various non-autoimmune strains of mice, was not sufficient to deplete B cells from autoimmune-prone (NZW x BXSB)F1 mice. (NZW x BXSB)F1 mice required approximately twice as many anti-IgM antibodies (1200 micrograms/wk) to maintain the suppression of B cell development. Continuous treatment with the sub-suppressive dose of anti-IgM antibodies led to a marked acceleration of autoimmune disease in (NZW x BXSB)F1 mice. In contrast, elimination of B cells in (NZW x BXSB)F1 mice with a higher dose of anti-IgM antibodies (1200 micrograms/wk) completely prevented autoantibody production, immune complex formation, and development of glomerulonephritis and vascular lesions associated with mononuclear cell infiltrations. Our results are a direct demonstration of the primary role of autoantibodies for the development of various tissue lesions seen in systemic lupus erythematosus (SLE) and indicates that autoreactive effector T cells, if they exist, play no major direct role in the pathogenesis of SLE, at least in (NZW x BXSB)F1 hybrid mice.

Treatment with high doses of anti-IgM prevents, but with lower doses accelerates autoimmune disease in (NZW x BXSB)F1 hybrid mice

We have treated autoimmune-prone (NZW x BXSB)F1 hybrid mice with polyclonal rabbit anti-mouse IgM antibodies starting from birth to define conditions leading to quantitative and functional elimination of the B cell compartment and to determine the effect of anti-IgM treatment on the development of autoimmune disease. A maintenance dose of anti-IgM antibodies (600 micrograms/wk), which efficiently induced B cell depletion in various non-autoimmune strains of mice, was not sufficient to deplete B cells from autoimmune-prone (NZW x BXSB)F1 mice. (NZW x BXSB)F1 mice required approximately twice as many anti-IgM antibodies (1200 micrograms/wk) to maintain the suppression of B cell development. Continuous treatment with the sub-suppressive dose of anti-IgM antibodies led to a marked acceleration of autoimmune disease in (NZW x BXSB)F1 mice. In contrast, elimination of B cells in (NZW x BXSB)F1 mice with a higher dose of anti-IgM antibodies (1200 micrograms/wk) completely prevented autoantibody production, immune complex formation, and development of glomerulonephritis and vascular lesions associated with mononuclear cell infiltrations. Our results are a direct demonstration of the primary role of autoantibodies for the development of various tissue lesions seen in systemic lupus erythematosus (SLE) and indicates that autoreactive effector T cells, if they exist, play no major direct role in the pathogenesis of SLE, at least in (NZW x BXSB)F1 hybrid mice.

Serotyping and electron microscopy studies of Staphylococcus aureus clinical isolates with monoclonal antibodies to capsular polysaccharide types 5 and 8

Monoclonal antibodies to Staphylococcus aureus capsular polysaccharide types 5 and 8 were prepared and used to serotype 821 clinical isolates of S. aureus from four countries. The capsular polysaccharide-binding sites on the bacterial membrane were examined by transmission and scanning electron microscopy.

Generation of agammaglobulinaemic mice by prenatal and postnatal exposure to polyclonal or monoclonal anti-IgM antibodies

Improved experimental conditions are described for the treatment of mice with anti-IgM antibody, which subsequently lead to B-cell deficiency and agammaglobulinaemia. Antibody transmitted via maternal milk alone was found to be more efficient in inducing suppression of serum immunoglobulin isotypes than prenatal transmission or postnatal intraperitoneal injections alone. However, the combined treatment by all three routes of exposure to anti-IgM resulted in total B-cell suppression associated with undetectable levels of all serum immunoglobulin isotypes. Furthermore, suppression of B-cell generation was also achieved with a rat monoclonal mu-specific antibody. The possibility of generating agammaglobulinaemic mice may be useful for investigating the influence of B cells on the generation of T-cell reactivities, and for analysing the effects of monoclonal antibodies in the absence of interfering serum immunoglobulin.

Immunity to lymphocytic choriomeningitis virus in B cell-depleted mice: evidence for B cell and antibody-independent protection by memory T cells

Immunity against lymphocytic choriomeningitis virus (LCMV) in anti-IgM-treated B cell-depleted mice was evaluated. We found that the following immune phenomena were independent of antibodies: the generation of virus-specific cytotoxic T cells; the footpad swelling response against locally injected LCMV; natural killer cell activity basic levels or after LCMV or poly(I) X poly(C) stimulation; immunopathologically mediated LCM after primary intracerebral inoculation; immunological memory in LCMV-immune mice assessed by immune protection against LCM after intracerebrally injected virus or as resistance against the local footpad swelling response to LCMV. This study demonstrates that humoral immunity plays no crucial role in immune protection and immunopathology in murine LCMV infection and suggests that protective memory T cell function is B cell and antibody independent.

Suppression of B cell development and antibody responses in mice with polyclonal rabbit and monoclonal rat anti-IgM antibodies. I. Characterization of the suppressed state

Mice treated from birth with polyclonal, crude or affinity purified rabbit or monoclonal rat anti-mouse IgM antibodies [b-7-6 and C-2-23: Eur. J. Immunol. 14: 753-757, 1984] were found to be heavily suppressed with respect to B-cell activities. Crude or affinity purified rabbit or monoclonal rat anti-mouse IgM gave comparable results as follows: serum IgM was below detectable levels; serum IgG was reduced to about 1-3% of normal levels; free anti-IgM was always detectable; IgM and/or kappa-light-chain positive cells as well as IgM-secreting cells were absent in various lymphoid organs; the B-cell mitogen lipopolysaccharide was unable to induce proliferative responses; primary antibody responses could not be induced against sheep red blood cells and phosphorylcholine; lymphoid organs were reduced in size and B-cell areas were not populated with lymphocytes; besides a 40% reduction in absolute lymphocyte numbers in the blood, we found increased platelet counts and a 10% eosinophilia in anti-IgM-treated mice.