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Biomedical subjects

R E Jenkins

Publications and source records attributed to R E Jenkins.

At least 37 records · Page 2Linked to original sources
PubMed1994

Neonatal lupus erythematosus.

We present a case of neonatal lupus erythematosus (NLE) in a black infant presenting with symmetrical depigmented macules on the face resembling vitiligo. NLE is a rare condition affecting newborn infants of mothers who have connective tissue disease, with or without autoantibodies to extractable nuclear antigens Ro (SS-A), La (SS-B) or ribonucleoproteins. Infants present with cutaneous lesions or congenital heart block or both. The skin lesions are usually annular and erythematous and transient and resemble those of subacute cutaneous lupus erythematosus. The presentation of this patient was therefore striking.

Facial Dermatoses↗
PubMed1994

Optimal conditions of 1 M NaCl splitting technique to demonstrate basement membrane zone antigens in bullous pemphigoid, epidermolysis bullosa acquisita and linear IgA bullous dermatoses.

We compare a series of conditions for inducing lamina lucida separation through normal skin specimens using 1 M NaCl for the detection of basement membrane zone auto-antibodies using indirect immunofluorescence. Skin was split at room temperature and at 4 degrees C with and without phenylmethylsulphonyl fluoride. Our results demonstrate that for the detection of bullous pemphigoid and epidermal-binding linear IgA bullous dermatoses antibodies skin should be split at 4 degrees C with enzyme inhibitors. For epidermolysis bullosa acquisita and dermal-binding antibodies skin can be split at room temperature.

Autoantibodies↗
PubMed1994

Cutaneous crystalline deposits in myeloma.

BACKGROUND: Myeloma is a plasma cell malignancy that usually presents with systemic manifestations or symptoms related to bone involvement. We describe the first case of crystalline protein deposition in the skin as the initial manifestation of myeloma. OBSERVATIONS: Crystals were found mainly in the extracellular space in the dermis of both involved and uninvolved skin in the absence of plasma cell infiltration. Crystals were also found in conjunctival tissue and bone marrow. CONCLUSIONS: We have described a unique case of myeloma that presented as facial and eyelid swelling. There were crystalline deposits in the skin and conjunctivae, but mechanisms of crystal formation and the factors causing local deposition were not established. However, treatment of the underlying disorder leads to resolution of the cutaneous features of crystal deposition.

Biopsy↗
PubMed1993

Complement polymorphism in herpes gestationis: association with C4 null allele.

BACKGROUND: Herpes gestationis (HG) is a rare, pregnancy-related skin disease characterized by the production of an autoantibody to a component of the hemidesmosome. It is associated with the class II antigens HLA-DR3 and HLA-DR4, but its potential association with the "class III antigens" C2, C4, and factor B has not previously been studied. OBJECTIVE: Our purpose was to study complement polymorphism in HG. METHODS: Using electrophoresis and immunofixation techniques, we determined the allele frequencies of C4A, C4B, C3, and factor B in 42 patients with a history of HG. RESULTS: Ninety percent of patients carried a C4 null allele (C4*QO). No statistically significant association with C3 or factor B alleles was seen. CONCLUSION: HG is associated with the presence of a C4*QO. Whether the C4*QO is the primary genetic association, or whether the C4*QO is related to its linkage disequilibrium with DR3 and DR4 has yet to be determined.

Adult↗
PubMed1993

Localization, turnover and conservation of gp15/400 in different stages of Brugia malayi.

The expression of a protein complex designated gp15/400, previously identified via extrinsic iodination of adult Brugia malayi, was examined by labelling all stages found in the mammalian host and immunoprecipitation with a specific antibody raised to a recombinant protein. In this way, gp15/400 could be detected in L3, L4, adult worms and microfilariae recovered from jirds and labelled with Bolton-Hunter reagent. Metabolic labelling indicated that gp15/400 was released into culture medium when adult worms were maintained in vitro, but at a rate slower than that of gp29, the major soluble cuticular glycoprotein. Immuno-electron microscopy showed that the protein complex was broadly distributed in different tissues, although it was not detectable in the cuticle of adult worms. Dense labelling was observed in the matrix of the basal laminae bordering the hypodermis, somatic musculature and oesophagus, and lower but significant labelling was seen in the cells overlying these extracellular matrices. Hybridization of genomic DNA with a cDNA probe encoding gp15/400 indicated that homologous genes were present in Dirofilaria immitis and Acanthocheilonema viteae. The failure to detect related genes in non-filarial nematodes was presumed to be due to divergence beyond the practical limits of detection by nucleic acid probes, as antibody reagents showed that the protein cross-reacted immunologically with ABA-1, a major protein allergen from the body fluid of Ascaris.

Aedes↗
PubMed1993

The anticonvulsant hypersensitivity syndrome.

Anticonvulsants can cause a characteristic hypersensitivity reaction. This multisystem reaction typically presents as fever, mucocutaneous eruptions, lymphadenopathy and hepatitis. There is cross-reactivity between different anticonvulsants, which complicates subsequent therapy. We report three cases to illustrate both the typical features, and less common complications, of this under-recognized and life-threatening syndrome.

Adult↗
PubMed1993

Anti-HLA antibodies in pemphigoid gestationis (herpes gestationis).

Pemphigoid gestationis (PG; herpes gestationis) is a rare autoimmune disease associated with pregnancy, currently defined by the presence of complement deposition along the cutaneous basement membrane zone. It is known to be associated with HLA-DR3 and DR4, and an increase in anti-HLA antibodies in those with a history of PG has been reported. We have studied 39 patients with an immunofluorescence-confirmed diagnosis of PG for the presence and specificity of anti-HLA antibodies. Anti-HLA antibodies were found in all 39 patients. Specificity was against class I antigens in 98% (controls 10%; P < 0.001) and class II antigens in 25% (controls 8.5%; P < 0.001). Almost all anti-HLA antibodies were cytotoxic. The universal presence of anti-HLA antibodies in PG suggests that they may develop coincidently with antibasement membrane antibodies, and may reflect a common immunological event.

Adult↗
PubMed1992

Cloning of a cuticular antigen that contains multiple tandem repeats from the filarial parasite Dirofilaria immitis.

An unusual antigen composed of tandemly repeated protein units was cloned from the filarial parasite Dirofilaria immitis. The antigen was initially identified by screening a lambda gt11 cDNA library with serum from dogs immunized with irradiated D. immitis third-stage larvae. DNA sequence analysis of the cDNA clone, Di5, revealed a continuous open reading frame composed of two 399-base-pair repeats arranged in tandem. Southern blot analysis of genomic D. immitis DNA showed that the gene coding for Di5 is composed of a tandem array of 25-50 copies of this same 399-base-pair repeat. Antiserum raised against recombinant Di5 protein detected a protein "ladder," from about 14 to greater than 200 kDa with steps approximately 15 kDa apart, on immunoblots of D. immitis extract. Metabolic labeling of adult parasites with [35S]methionine showed that Di5 is synthesized as a large precursor that is subsequently cleaved to produce the ladder-like array. These results suggest that the characteristic ladder is created by proteolytic cleavage of the precursor at the same site in each monomer. The Di5 antigen was localized to the cuticle and hypodermis of adult D. immitis by immunoelectron microscopy. Both male and female parasites were found to release Di5 when cultured in vitro. DNA hybridization analysis demonstrated that Di5 is a member of a gene family present in many filarial parasites that infect both animal and human populations.

Amino Acid Sequence↗
PubMed1991

A proline-rich structural protein of the surface sheath of larval Brugia filarial nematode parasites.

Both cDNA and genomic DNA sequences have been isolated which encode a proline-rich precursor protein of the sheath from microfilariae, the first stage larvae of the filarial nematode parasites Brugia pahangi and Brugia malayi. This 22-kDa protein is soluble only under reducing conditions and is extensively cross-linked by both disulfide and nonreducible bonds. Immunogold electron microscopy shows that the protein is localized exclusively in the sheath, a vestigial remnant of the eggshell, which is retained by and encloses the mature microfilaria. Analysis by Western blotting confirms that the protein is expressed only in microfilariae and adult female worms, although transcripts are detectable only in adult females. The deduced amino acid sequence contains a short N-terminal hydrophobic putative leader sequence, a central repetitive domain that contains 14 copies of a degenerate 5-amino acid repeat with the consensus sequence Met-Pro-Pro-Gln-Gly, and a C-terminal proline-rich domain flanked by clusters of cysteine residues. These clusters can be aligned with cysteine residues implicated in cross-linking of a family of cuticular collagens originally identified in Caenorhabditis elegans but which extends to other nematodes.

Amino Acid Sequence↗
PubMed1990

Cuticular localisation and turnover of the major surface glycoprotein (gp29) of adult Brugia malayi.

A polyclonal antiserum was raised to a gel purified preparation of the major water-soluble surface glycoprotein (gp29) of adult Brugia malayi, and used to define the stage specificity of expression, localisation (by immunoelectron microscopy) and the dynamics of biosynthesis and turnover via pulse-chase experiments. Gp29 was not detected in surface-labelled preparations of either pre- or post-parasitic third stage larvae (L3), but was present in fourth stage larvae (L4), where its mass was estimated to be 30 kDa by SDS-PAGE. In both L4 and adult worms, the protein resolved as 3 distinct species in 2-dimensional electrophoresis, with pIs from 6.5 to 7.5. Pulse-chase studies via metabolic labelling of adult worms with [35S]methionine in vitro indicated that gp29 was processed from a 32-kDa precursor to the mature molecule within 45 min and that it was secreted into culture medium within 5 h of synthesis. On extended culture, gp29 was converted to a 56-kDa product, presumably either by complex formation or covalent linkage with another secreted molecule. This higher molecular weight component had a more acidic pI of 4.5 and was insensitive to digestion with N-glycanase. Immunoelectron microscopy showed that gp29 was distributed throughout the cuticle and hypodermal cell layer of adult worms, suggesting that the protein was synthesised in the hypodermis, and that turnover into culture medium occurred through the cuticle. The protein appeared to concentrate at the distal cell membrane of the hypodermis, particularly at the stacked invaginations. Additional immunostaining was found on the basement membrane of the basal lamina of the intestine.

Animals↗
PubMed1985

Modulation of Epstein-Barr virus-induced B-cell activation by concanavalin A.

Direct addition of the T-cell mitogen, concanavalin A (Con A), to cultures of Epstein-Barr virus (EBV)-stimulated peripheral blood mononuclear cells (PBMC) resulted in a dose-dependent inhibition of immunoglobulin M (IgM) secreted in the supernatant, as measured by an enzyme-linked immunosorbent assay. Furthermore, Con A inhibited IgM secretion of isolated T-depleted cells stimulated with EBV, and both the proliferation and IgM secretion of EBV-driven lymphoblastoid cell lines. T-Enriched cells, precultured for 48 hr with Con A, were also able to suppress the IgM response of fresh autologous PBMC stimulated with EBV. This suppression was radiation sensitive (2000 rad), a procedure which resulted in enhancement of the IgM secretion of the responder cells in two out of three experiments. Studies on the long-term effects of Con A showed that the early suppression of IgM secretion was transient and that the mitogen prevented the development of the cytotoxic T-cell response normally seen with lymphocytes from EBV-seropositive donors after 5 weeks of culture. Thus, Con A appears to modulate human lymphocyte responses to EBV by multiple mechanisms.

B-Lymphocytes↗
PubMed1983

Computer-aided measurement of transverse axon sections for morphology studies.

A study has been made of a general-purpose minicomputer image analysis system to provide medical researchers with data needed in morphology studies of myelinated axon sections. The system was designed to provide data equivalent to that produced by manually outlining and quantifying the axon and myelin boundaries. The system hardware and algorithms are described and experimental results presented comparing manual and automated data. The results show that a system with limited automation is an order of magnitude faster than manual methods in providing data with comparable accuracy and improved repeatability.

Animals↗