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Biomedical subjects

J L Benach

Publications and source records attributed to J L Benach.

At least 73 records · Page 4Linked to original sources
PubMed1989

Adult Ixodes dammini on rabbits: development of acute inflammation in the skin and immune responses to salivary gland, midgut, and spirochetal components.

Rabbits exposed to female Ixodes dammini (both uninfected and infected with Borrelia burgdorferi) or injected with B. burgdorferi showed an acute inflammatory response in the skin. Granulocytes and monocyte-histiocytes were the predominant infiltrating cells. Spirochetes were detected in the tick feeding cavities in the deep dermis. The inflammatory process was accompanied by polyclonal antibody responses to tick salivary gland components. Western blots showed that immune rabbit serum reacted with proteins of molecular masses of 8, 24, and 36-41 kilodaltons in both unengorged and engorged tick salivary glands. Additional reacting bands in the immunoblot of the engorged salivary gland indicated that new antigenic components of the salivary gland are synthesized during engorgement. Rabbits did not produce antibodies to tick midgut components. Murine monoclonal antibody 11G1 detected outer surface protein A of B. burgdorferi in immunoblots of midguts from unengorged ticks, faintly in engorged salivary gland, and seldomly in unengorged salivary gland, findings suggesting that the spirochete is transmitted to the host via tick saliva during the later stages of feeding.

Animals↗
PubMed1989

Adherence of the Lyme disease spirochete to glial cells and cells of glial origin.

Lyme disease, a tick-borne spirochetosis caused by Borrelia burgdorferi, produces protean neurologic manifestations, yet its neuropathogenesis is poorly understood. The affinity of the spirochete for cells of primary rat brain cultures and of the C6 glioma cell line was studied. B. burgdorferi adhered to both types of cells in a dose-dependent manner and exhibited an affinity for an extracellular matrix produced by the primary and by glioma cell cultures. Adherence of the spirochetes to the glial components of the primary brain culture could be an early event in the production of neurological injury; its affinity for cells could be the reason for its infrequent isolation from cerebrospinal fluid.

Animals↗
PubMed1989

Fluoroimmunoassay studies with solubilized antigens from Borrelia burgdorferi.

Sodium deoxycholate-solubilized Borrelia burgdorferi antigen was prepared for use in a solid-phase fluoroimmunoassay (FIA-L) to detect antibodies in Lyme disease. Serum specimens were tested by FIA-L and by a microimmunofluorescence test. The FIA-L results are comparable to those of the standard microimmunofluorescence test. The overall agreement was 0.98. Moreover, the FIA-L procedure is simple and rapid; fluorescence is objectively determined and is proportional to antibody titer.

Antibodies, Bacterial↗
PubMed1989

Identification and characterization of an endoflagellar antigen of Borrelia burgdorferi.

The 41-kD antigen of Borrelia burgdorferi is an immunodominant protein that is recognized early by antibodies in sera from Lyme disease patients and known to be associated with the endoflagella. We identified the 41-kD endoflagellar antigen to be a single polypeptide with an apparent isoelectric point (pI) of 6.5 by two-dimensional (2-D) electrophoresis. This polypeptide, which we designated P41F alpha, was heavily labeled by 125I in 2-D autoradiographs of B. burgdorferi whole-cell lysates and was recognized by a murine monoclonal antibody (MCB1) and human antisera in 2-D immunoblots. NH2-terminal sequence analysis showed 80% homology between P41F alpha and the 33-kD endoflagellar protein of Treponema pallidum. Results of indirect immunofluorescence assays (IFA), Triton X-114 phase partitioning, and agglutination studies suggested a possible surface exposure of the polypeptide. Silver stained 2-D gels also revealed the presence of another 41-kD species, with an apparent pI of 6.6 (designated P41 beta), which was not radioiodinated in 2-D autoradiographs, and was not recognized by MCB1 or human antisera. NH2-terminal sequence analysis of P41 beta revealed no homology with P41F alpha, leading to the conclusion that they are not related.

Agglutination Tests↗
PubMed1989

The pathogenesis of Lyme disease.

Lyme disease affects several major organ systems and leads to chronic illness. The pathogenesis of this disease appears to be centered around the long-term persistence of the organisms in tissues. In Lyme disease, isolations of B. burgdorferi are rare. It is thought that few organisms actually invade the host and that host mediators amplify the inflammatory response. Immune and nonimmune phagocytosis leading to bacterial killing occurs in Lyme disease. This organism shows preference for cell surfaces and tissues which may explain the paucity of isolations but also displays characteristic nonspecificity in its adherence to eukaryotic cells. This lack of specificity may explain its capacity to reside and injure vastly different tissues. Autoimmune mechanisms may coincide with spirochetal persistence in the pathogenesis of chronic Lyme disease.

Antigen-Antibody Complex↗
PubMed1989

Isolation of interleukin 1 from joint fluids of patients with Lyme disease.

To investigate the role of interleukin 1 (IL-1) in Lyme arthritis we assayed synovial fluids (SF) for the presence of IL-1 activity. Crude SF from patients with Lyme disease showed IL-1-like activity. Chromatography of joint fluids revealed activity at 15-20,000 daltons. Two populations of cells were grown, which produced significant IL-1 activity when stimulated with the Lyme disease spirochete or its lipopolysaccharide. IL-1 activity from SF or stimulated cells was neutralized with an antihuman IL-1 antibody. Our results suggest IL-1 is important in the pathogenesis of Lyme arthritis, and is similar to other arthritides.

Borrelia↗
PubMed1988

A focus of Rocky Mountain spotted fever within New York City.

In the spring and summer of 1987, four persons acquired Rocky Mountain spotted fever within New York City, an area in which the disease had not previously been known to be endemic. Three of the four patients were residents of the Soundview area of the Bronx. All diagnoses were confirmed by indirect fluorescent-antibody tests. Environmental investigation revealed that the tick vector for Rickettsia rickettsii, Dermacentor variabilis, was present in a local park. Of the 66 specimens of D. variabilis collected, 5 (8 percent) were positive for rickettsiae from the spotted fever group. Of an additional 96 specimens of D. variabilis, 5 (5 percent) were found positive for rickettsiae by a more specific monoclonal antibody assay. Eight additional New York City parks in all five boroughs were searched for ticks. D. variabilis was found in only one other park; of the 147 ticks collected there, none were positive for rickettsiae. These findings emphasize the focal nature of Rocky Mountain spotted fever and the need to consider that disease in the differential diagnosis of any obscure acute febrile illness, even in the absence of a history of travel to known endemic areas.

Adult↗
PubMed1988

A murine IgM monoclonal antibody binds an antigenic determinant in outer surface protein A, an immunodominant basic protein of the Lyme disease spirochete.

A hybridoma cell line formed by the fusion of the P3x63-Ag8.653 myeloma cell line with splenocytes from BALB/c mice immunized with Borrelia burgdorferi produced an IgM monoclonal antibody (mAb-11G1) with kappa-light chains which detected an antigenic determinant in a major spirochetal protein of m.w. approximately 31,000, also known as outer surface protein A (OSP-A). Apparent saturation was reached in approximately 35 min with 34 ng of mAb-11G1 binding to 5 X 10(7) spirochetes giving an estimated 4.8 X 10(2) IgM molecules per spirochete and thus a minimum of 480 binding sites per organism. Enzymatic digestion studies suggest that the antigenic determinant to mAb-11G1 is contained within the peptide chain of OSP-A as binding could be eliminated by treatment of the spirochetes with proteinase K, Pronase and pepsin (100 to 200 micrograms/ml of enzyme) but not by trypsin or bromelain treatment. Periodate oxidation as well as mixed and endoglycosidase treatment of the spirochetes did not alter the binding of mAb-11G1. Two-dimensional gel electrophoresis of whole spirochetal cell lysates disclosed that OSP-A is a heterogeneously charged basic protein with an apparent isoelectric point range from 8.5 to 9.0. Amino acid analysis of OSP-A showed a 10% lysine component which could provide the basic nature to the protein. OSP-A with the intact antigenic determinant for mAb-11G1 can be found in the urine of hamsters experimentally infected with B. burgdorferi.

Amino Acids↗
PubMed1988

Use of an autologous antigen in the serologic testing of patients with erythema migrans of Lyme disease.

We attempted to detect an early rise in antibody titers to Borrelia burgdorferi in the serum of patients with erythema migrans of Lyme disease by utilizing B. burgdorferi isolates obtained from patients' own skin lesions instead of the B31 reference strain. B. burgdorferi was isolated from nine of 23 skin biopsy specimens submitted for culture. Elevated antibody titers were not detected in any of the 23 acute serum samples by immunofluorescence assay. The antigens derived from patient isolates were no more effective than the reference strain in detecting antibodies in patients with early Lyme disease.

Adult↗
PubMed1988

Biological activity of Borrelia burgdorferi antigens.

OSP-A (approximately 31 kDa) and flagellins (approximately 41 kDa) are prominent antigens of Borrelia burgdorferi. Both OSP-A and flagellins are immunogenic in patients and in experimentally infected mice and hamsters, but the kinetics of antibody formation to each vary considerably between the species. The role of eluted OSP-A and flagellins in the cellular immune response, chemotaxigenesis, and cytoadherence was measured. Eluted OSP-A and flagellins stimulated the proliferation of normal and infected mouse splenocytes but only the peripheral mononuclear cells of patients. Both OSP-A and flagellins induced human neutrophil chemotaxis, but at significantly reduced levels as compared to other known chemotactic peptides. Live B. burgdorferi adhere to HEp-2 cells in culture. OSP-A and the flagellins are involved in adherence; monoclonal antibodies to determinants in these proteins partially inhibited adherence. Cytoadherence was also partially inhibited by treatment of the cells with tunicamycin and sialidase.

Animals↗
PubMed1988

Occupational risk of Lyme disease in endemic areas of New York State.

Although Lyme disease (LD) is the most common tick-borne disease in the United States, little is known about the frequency of and risk factors for infection with Borrelia burgdorferi in occupational groups. In 1986, we recruited primarily outdoor workers from six employee groups in southeastern New York where LD is endemic. Of 414 participants who completed questionnaires and had blood samples tested for antibodies against B. burgdorferi by ELISA and Western immunoblot, 27 (6.5%) were seropositive, but only 14 of the 27 reported previous symptoms of LD. Persons who spent more than 30 hours per week outdoors during leisure were 2.5 times more likely to be seropositive than those who did not (p = .02). Those with a history of outdoor employment were twice as likely to be seropositive as those without such a history, although this finding was not statistically significant (p = .70). However, the seroprevalence rate for the employees was 5.9 times higher than the rate for a comparison group of anonymous blood donors from the same region of New York (p less than .001). These results suggest that there was a relatively high rate of seropositivity for the employee groups and that infection was frequently asymptomatic and associated with outdoor exposure.

Adolescent↗
PubMed1987

The significance of controls in Lyme arthritis of children.

In order to better define the specificity of Lyme disease (LD) seropositivity and seronegativity during a study of Lyme arthritis in a pediatric rheumatology population, three groups of controls are in the process of being developed. Children with other rheumatic disorders. Siblings and parents of children with Lyme arthritis. Individuals with intense environmental exposure to LD. Sera from each have been tested for antibody to Borrelia burgdorferi (Bb), by indirect immunofluorescence assay (IFA), enzyme linked immunosorbent assay (ELISA), or both. Of the 57 children with rheumatic disorders of whom 25 had JRA, 4 (7%) reached a border zone, non-specific level of 1:64 by IFA, and 53 sera were non-reactive. 7 household relatives of LD cases had non-reactive sera. The 42 intensely Bb-exposed individuals all had non-reactive sera. The fact that none of the 106 controls attained a clinically significant level of antibody is a general indication of the specificity of the serologic tests. The use of selected control groups such as these might potentially solve the ambiguities in clinical-laboratory correlations in Lyme arthritis.

Adolescent↗