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Biomedical subjects

S E Walker

Publications and source records attributed to S E Walker.

At least 127 records · Page 7Linked to original sources

Eosinophilic fasciitis with porphyria cutanea tarda and progressive destructive arthritis.

The course of arthritis with eosinophilic fasciitis is poorly documented. We report a patient in whom polyarthritis preceded the clinical appearance of eosinophilic fasciitis and progressed over a 14-year period to a destructive process with inflammatory and degenerative characteristics. Porphyria cutanea tarda and transient extramedullary pancytopenia complicated this patient's disease.

Arthritis↗

Defective primary and secondary IgG responses to thymic-dependent antigens in autoimmune PN mice.

Palmerston North (PN) mice spontaneously develop autoimmune disease resembling SLE. Because immune responsiveness has not been defined in this strain, a study was designed to assay primary splenic plaque-forming cell (PFC) responses to thymus-dependent (TD) and thymus-independent (TI) Ag. Initial surveys of PN mice inoculated with the TD Ag SRBC showed adequate production of IgM PFC, but small numbers of IgG PFC were developed with polyspecific antiserum. In contrast, H-2-compatible DBA/1 control mice gave the expected responses to SRBC (IgG plaques elevated twofold compared with IgM plaques). PN mice had the usual responses to Ag that are largely TI; both PN and DBA/1 mice had active IgM and modest IgG responses to TNP-LPS and TNP-Ficoll. Additional experiments determined that PN mice had similar patterns of defective IgG responses to several different TD Ag (SRBC, horse RBC, and DNP-keyhole limpet hemocyanin). In each instance, the usual predominance of IgG1 plaques was absent, and total numbers of plaques developed with antisera specific for IgG isotypes were suppressed. Defective PN IgG production was evident as early as 3 wk of age, was not influenced by aging to 43 wk, and was not corrected by increasing the antigenic challenge 10-fold. PN spleen cells treated with monoclonal anti-Thy-1.2 and C were injected with pools of DBA/1 T cells into 850-rad irradiated (DBA/1 x PN)F1 hybrids. These recipients expressed low IgG1 responses to SRBC, suggesting that the B cell-containing fraction that was not lysed by anti-Thy-1.2 transferred the PN defect. PN mice, which do not respond to TD Ag with active IgG production, contradict the proposal that autoimmunity is associated with hyper-responsiveness to TD and TI Ag.

Animals↗

Pain management in rheumatoid arthritis patients. A cognitive-behavioral approach.

To examine the effectiveness of a cognitive-behavioral pain management program for patients with rheumatoid arthritis, three patient groups were studied: a cognitive-behavioral group (CB), an attention-placebo group, and a control group. The CB group received a comprehensive, 12-month pain management program that taught coping strategies such as problem-solving techniques, relaxation training, strategies for attention diversion, and training in family dynamics and communication. Dependent measures included pain, coping strategies, psychological status, functional status, and disease status. Data analysis at 12 months revealed benefits for the CB group in the area of enhanced coping strategies. Specifically, the CB subjects showed significantly greater use of coping strategies and significantly more confidence in their ability to manage pain. The findings are discussed in terms of the importance of enhanced self-efficacy and personal control for patients with rheumatoid arthritis.

Adaptation, Psychological↗

Hormone control of autoantibodies to calf thymus nuclear extract (CTE) and DNA in MRL-lpr and MRL-+/+ mice.

Because hormonal influences on autoimmune disease in MRL-lpr and MRL-+/+ mice have not been defined completely, we examined animals which had been castrated and implanted with the opposite sex hormone. Antibodies directed at non-DNA antigens in a calf thymus nuclear extract (designated CTE) and specific anti-DNA antibodies were increased in estrogen-treated males, testosterone-treated females, and sham-operated female controls compared to sham-operated males. Analysis by sucrose gradient ultracentrifugation revealed that gonadal hormones exerted marked differences in the distribution and nature of circulating IgM anti-CTE antibodies. Although 19 S IgM was the predominant form of anti-CTE antibodies in experimental groups showing elevated anti-CTE responses, estrogen-treated male MRL-lpr mice expressed a large additional population of anti-CTE IgM antibody released by acid dissociation of apparently cryptic complexes. An unexpected additional finding was the presence of cryptic anti-CTE IgG (7 S) in all groups of MRL-lpr and MRL-+/+ mice, revealed only in sucrose gradient analysis under acid conditions. It is suggested that sex-related factors may account, in part, for apparent differences in levels of circulating autoantibodies observed in MRL mice by influencing the degree to which autoantibody populations exist in circulating complexes.

Animals↗

Interindividual and intraindividual variability in acetylation: characterization with caffeine.

The degree of interindividual and intraindividual variability in acetylator activity was investigated with caffeine used as a probe of enzyme activity. Acetylator phenotype and relative N-acetyltransferase activity were estimated in 46 subjects by measuring the urinary ratio of two metabolites, AFMU/1-MX, after a single 300 mg oral dose of caffeine on five separate occasions. Thirty homozygous slow (rr) and 15 heterozygous rapid (Rr) acetylators were identified. The degree of interindividual variability in acetylator activity was observed to be a mean of 32% (range 27% to 36%) and 20% (range 11% to 29%) in the rr and Rr groups, respectively. The mean intraindividual variation on repetitive measurement was 19% (range 6% to 49%) in the rr and 14% (range 7% to 24%) in the Rr acetylator group. Four subjects had apparent changes in acetylator activity with time such that they were unable to be assigned to any one acetylator group. Two of these four subjects exhibited apparent homozygous rapid acetylator activity intermittently during the 5-week trial. This variability may explain, in part, some of the high degree of patient variability observed in the toxicity, efficacy, and drug-related disease associated with acetylated drugs and environmental toxins.

Acetylation↗

Universal spondylodiscitis in a patient with erosive peripheral arthritis and apatite crystal deposition.

A patient with erosive peripheral arthritis in whom vasculitis and monoclonal IgG kappa paraprotein were associated with sacroiliitis and widespread destruction of intervertebral discs is reported. Crystals resembling apatite were identified in intervertebral disc material, and we postulate that the discitis was accelerated by apatite deposition. Our case illustrates a unique example of axial involvement in rapidly progressive joint disease.

Adult↗

Sex hormones modulate the response of pulmonary perivascular inflammation to cyclophosphamide therapy in MRL/MpJ-lpr/lpr mice.

Responses of pulmonary perivascular infiltrates to immunosuppressive therapy with cyclophosphamide (CY) were evaluated in the MRL/MpJ-lpr/lpr (MRL/1) mouse, a model for the study of systemic lupus erythematosus. Male and female mice were divided into the following groups: controls injected with saline; intact mice receiving CY; castrated CY-treated mice; castrated, hormone implanted, CY-treated mice. CY treatment began at 30 days of age and animals were killed at 60 days of age. Lungs were fixed-inflated to 26 cm H2O pressure with glutaraldehyde-formaldehyde fixative. The pulmonary perivascular response to immunosuppressive therapy was graded depending on the extent of infiltrates surrounding 15 pulmonary vessels per animal. Intact males treated with CY alone had almost complete clearing of perivascular infiltrates, whereas intact females did not respond to therapy. Castrated CY-treated males showed a decreased response to CY compared to intact CY-treated males. Castrated, estradiol-implanted males had no response to CY therapy. Estradiol interfered with the therapeutic response to CY in male MRL/1 mice.

Animals↗

Rectal absorption of propylthiouracil.

The rectal absorption of propylthiouracil (PTU) was studied and compared to oral absorption in normal volunteers. Plasma levels of PTU after administration of suppositories of PTU base and PTU diethanolamine were significantly lower compared to the oral route. Elevated plasma reverse T3 levels were demonstrated after each treatment, however, suggesting a desirable therapeutic effect at this dosage level for all preparations.

Administration, Rectal↗

Metacarpophalangeal arthropathy associated with manual labor (Missouri metacarpal syndrome). Clinical radiographic, and pathologic characteristics of an unusual degeneration process.

We describe 7 manual laborers with painful, palpably enlarged metacarpophalangeal joints. Characteristic radiographic changes were joint space loss, prominent osteophytes, and cystic metacarpal heads most prominent in the second and third metacarpophalangeal joints. In 3 of 4 patients, joint biopsy specimens showed subsynovial fibrosis and villous hyperplasia. All 7 patients had similar backgrounds of heavy work demanding sustained gripping motions of both hands, for periods that exceeded 30 years. We designated their condition metacarpophalangeal arthropathy associated with manual labor.

Aged↗

Suppression of reproductive function in autoimmune NZB/W mice: effective doses of four contraceptive steroids.

Oral contraceptives have been implicated in causing flares of systemic lupus erythematosus in humans, and studies of these agents in the NZB/W mouse model of lupus may help to elucidate mechanisms responsible for disease activation. To define doses which effectively suppress reproductive function in NZB/W mice, we implanted groups of NZB/W females with Silastic capsules containing increasing doses of four compounds: norethindrone (NE) 0.5-5.0 mg, norgestrel (NG) 1.0-7.5 mg, medroxyprogesterone (MP) 0.5-20.0 mg, and ethinyl estradiol (EE) 0.5-5.0 mg. Controls received empty implants. Serum concentrations of LH and FSH, uterine weight, endometrial proliferation, and luteal tissue were assessed after 3 weeks of treatment. Based upon these parameters, we determined that effective doses were 5.0 mg NE, 7.5 mg NG, and 0.5 mg EE given as single implants and 10.0 mg MP given in two 5.0-mg implants. This is the first dosing study of contraceptive steroids in a murine model of lupus. Effective, nontoxic doses of these drugs can now be employed in studies of interactions between gonadal hormones and autoimmunity.

Animals↗

Functional-anatomical studies on the terminal nerve projection to the retina of bony fishes.

We have explored the structure and actions of terminal nerve (TN) fibers in the teleostean retina, the most accessible of TN projections. Using immunocytochemistry we have shown that the goldfish TN contains neuropeptides related to the molluscan cardioexcitatory peptide (FMRFamide) as well as luteinizing hormone-releasing hormone (LHRH). Retinal TN terminals were found upon major dendrites in the distal inner plexiform layer and neuronal cell bodies in the amacrine cell layer. Electron-microscopic double-labeling revealed TN terminals applied to the surface of [3H]-dopamine-, glycine-, and gamma-aminobutyric acid (GABA)-accumulating cells. Synthetic LHRH and FMRFamide at less than 1 microM modified spontaneous and light-evoked activity of ganglion cells in isolated superfused goldfish retina, especially during the active breeding season. Salmon(I)-LHRH was 10-30 times as potent as mammalian LHRH and caused rapid, prolonged desensitization. We conclude that LHRH- and FMRFamide-like peptides may be released by retinal TN endings, probably in concert with reproductive activity, and that they act independently through horizontal and/or amacrine cell pathways to modify visual information processing in the retina.

Animals↗

Gonadotropin-releasing hormone (GnRF), molluscan cardioexcitatory peptide (FMRFamide), enkephalin and related neuropeptides affect goldfish retinal ganglion cell activity.

Recently gonadotropin-releasing hormone (GnRF)-like and molluscan cardioexcitatory peptide (FMRFamide)-like compounds have been colocalized immunocytochemically to the terminal nerve, a presumed olfactoretinal efferent system in goldfish. In the present study these and related neuropeptides were shown to affect ganglion cell activity, recorded extracellularly, when applied to the isolated superfused goldfish retina. GnRF was usually excitatory. Salmon GnRF (sGnRF) was 10-30x more potent than chicken or mammalian GnRF. FMRFamide and enkephalin also were often excitatory but caused more varied responses than sGnRF. Met5-enkephalin-Arg6-Phe7-NH2 (YGGFMRFamide), which contains both enkephalin and FMRFamide sequences, tended to act like both of these peptides but with mainly enkephalin-like properties. Neuropeptide Y and the C-terminal hexapeptide of pancreatic polypeptides, whose C-terminus (-Arg-Tyr-NH2) is closely related to that of FMRFamide (-Arg-Phe-NH2), gave no consistent responses. Threshold doses were equivalent to: 0.1 microM for sGnRF; 0.5 microM for YGGFMRFamide; 1.5 microM for FMRFamide and enkephalin. Rapid, complete and irreversible desensitization was induced by single, 10-20x threshold doses of sGnRF; but desensitization was infrequent and limited with the other peptides. In general, all peptides tested affected the spatially and chromatically antagonistic receptive field components similarly, but selective actions were seen in a few cases with FMRFamide and with the opioid antagonist, naloxone. Responses, especially to sGnRF and FMRFamide, tended to be most frequently obtained and pronounced in winter and spring, suggesting a correlation with seasonally regulated sexual and reproductive activity. Our observations provide further evidence for transmitter-like roles of neuropeptides related to sGnRF and FMRFamide in the teleostean terminal nerve. The actions of agonists and antagonists, singly and in combination, imply strongly that there are distinctive postsynaptic receptors and/or neural pathways for GnRF-, FMRFamide- and enkephalin-like peptides in the goldfish retina.

Animals↗

Accelerated autoimmune disease and lymphoreticular neoplasms in F1 hybrid PN/NZB and NZB/PN mice.

This report describes the first studies of inheritance of autoimmunity in inbred Palmerston North (PN) mice, a model of systemic lupus erythematosus (SLE). Mating of PN mice with the nonautoimmune DBA/2 strain produced evidence that PN disease had a recessive mode of inheritance. When PN mice were crossed with autoimmune NZB mice, female offspring from both crosses developed anti-DNA antibodies and died prematurely with vasculitis, renal disease, and lymphomas. In contrast, reciprocal hybrid males had different patterns of mortality; PN/NZB males from the PN female X NZB male mating had moderately prolonged life spans, whereas NZB/PN males from the opposite cross (NZB female X PN male) had prolonged survival to the mean age of 104 weeks. To determine if testicular hormones were solely responsible for increased longevity in hybrid males, PN/NZB and NZB/PN mice were castrated at 2 weeks of age and compared to sham-operated littermate controls. Prepubertal castration did not influence longevity in PN/NZB males, but loss of gonadal hormones significantly reduced life spans in reciprocal NZB/PN males. Female hybrids were not affected by oophorectomy. Because castration changed disease expression only in male hybrids from the NZB female X PN male cross, it was concluded that parentage influenced sensitivity to the protective effects of male hormones. Although surgical sterilization had disparate effects on males, castrated PN/NZB and NZB/PN males consistently outlived oophorectomized females. The lack of clear-cut reversal of disease in males subjected to early castration suggested that nonhormonal, possibly genetic, factors contributed to longevity in both groups of male hybrids.

Animals↗

The clinical significance of the in vivo antinuclear antibody phenomenon.

We describe a patient with systemic lupus erythematosus (SLE) with demonstrated direct immunofluorescent staining of epidermal nuclei in a rim pattern, the second case of in vivo antinuclear antibody (ANA) producing a rim pattern in normal epidermis. A review of the literature showed that 258 cases have been reported of in vivo ANA deposition in epidermal nuclei from nonlesional skin. This phenomenon, which is most common in patients with mixed connective tissue disease, SLE, and scleroderma, correlates frequently with antibodies to extractable nuclear antigens. In vivo ANA have also been described in renal and pulmonary tissue from patients with SLE. In most cases, the pathogenic significance of the phenomenon is unknown.

Antibodies, Antinuclear↗

Pulmonary inflammation in autoimmune MRL/Mp-lpr/lpr mice. Histopathology and bronchoalveolar lavage evaluation.

Early detection of lupus pneumonitis is difficult because it requires lung biopsy. The authors describe here in detail the age-related histologic changes in pulmonary inflammation, the age-related changes in bronchoalveolar lavage (BAL), and the effect of cyclophosphamide (8 mg/kg) on pulmonary inflammation and bronchoalveolar lavage in MRL/Mp-lpr/lpr mouse, an animal model of systemic lupus erythematosus. To assess the evolution of pulmonary inflammation and response to cyclophosphamide therapy, they compared the age-related progression of pulmonary inflammation with sequential changes in BAL cell populations in this autoimmune mouse model. A striking similarity was noted between age-related changes in pulmonary inflammation and lymphocyte counts in BAL. A trend to reduction in histologic evidence of inflammation was reflected by lymphocytes in BAL in cyclophosphamide-treated (8 mg/kg/day) males but not in females. There was a striking sex-related difference in that the histologic evidence of pulmonary inflammation and bronchoalveolar lavage lymphocyte count in cyclophosphamide-treated males was significantly lower than cyclophosphamide-treated females of the same age.

Aging↗

Hormonal modulation of responses to thymus-independent and thymus-dependent antigens in autoimmune NZB/W mice.

Previous work suggested that gonadal steroids influence immunity through the thymus, but the mechanisms were unclear. To investigate the effects of these hormones on immune responses to T1 and TD antigens in autoimmune mice, we studied hybrid NZB/W mice and the nonautoimmune DBA/2 strain. Mice castrated at 14 days of age were implanted with Silastic capsules releasing, in adults, physiologic levels of E2 in males or Te in females. Sham-operated controls received empty capsules. Splenic PFC were quantified 4 to 5 days after challenge with the TI2 antigen TNP-Ficoll, the TI1 antigen TNP-LPS, or the TD antigen SRBC. Young castrated NZB/W males implanted with E2 had striking enhancement of IgM responses to TNP-Ficoll when compared to castrated Te-treated females and comparable sham-operated controls of both sexes. E2 also stimulated responses to TNP-LPS. In response to challenge with SRBC, young E2-treated NZB/W males had a consistent trend to increased IgM PFC, and the stimulatory effect of E2 on IgG plaques was variable. Physiologic doses of Te had no consistent effect on responses in young mice. In old female NZB/W mice, Te caused PFC response after immunization with TNP-Ficoll to resemble age-matched NZB/W males. As sham-operated NZB/W females grew older, PFC responses to SRBC fell. This age-related phenomenon was delayed, however, in female castrates implanted with Te. In contrast, Te clearly suppressed responses to TNP-LPS. Implantation of E2 did not alter responses to TNP-Ficoll, TNP-LPS, or SRBC in nonautoimmune DBA/2 males. This finding suggested that exogenous E2 given in physiologic doses did not influence immunologic responsiveness in a normal strain to the degree seen in hormone-sensitive NZB/W mice. It was concluded that E2 enhanced responses to a variety of exogenous antigens in autoimmune NZB/W mice. The most consistent E2-induced increase in PFC response was observed with TI antigens, suggesting that E2 exerted its effects on B cells or Ts.

Animals↗