Search

Although regional lymph nodes (LN) have been extensively studied as rich sources of effector T cells in contact hypersensitivity (CH), it remains unknown whether T cell responses in the LN reflect those in effector skin sites. We previously showed that repeated elicitation of CH results in a shift in the time course of Ag-specific CH from a delayed-type hypersensitivity response to an early-type response, a reflection of a shift in cutaneous cytokine expression from a type 1 to a type 2 profile. To investigate whether repeated elicitation of CH could also drive T cell development to the type 2 phenotype in the regional draining LN, sequential cytokine gene expression after hapten application was assessed during both the acute and the chronic phase of CH. In the draining LN the shift to type 2 cytokine production was also observed, but more mixed patterns of responses were induced than in the corresponding skin sites. The chronic LN cells (LNC), when stimulated in vitro, produced markedly lower levels of type 1 cytokines and higher levels of type 2 cytokines than the acute LNC. A successful passive transfer of an early-type response by the LNC was only induced in the recipient mice when the skin sites chronically treated with hapten were elicited. These results indicate that an early-type response by regional LNC would take place only in a milieu with sufficient levels of type 2 cytokines.

Although considerable attention has been paid to the development of cytokine synthesis heterogeneity during memory T cell differentiation, little information is available on how this function is coregulated with homing receptor expression. The development of skin-homing, CD4+ memory T cells in the human provides an excellent model for such investigation, since 1) the skin supports both Th1- and Th2-predominant responses in different settings, and 2) the skin-homing capability of human memory T cells correlates with and appears to depend on expression of the skin-selective homing receptor cutaneous lymphocyte-associated Ag (CLA). In this study, we used multiparameter FACS analysis to examine expression of CLA vs IFN-gamma, IL-4, and IL-2 synthesis capabilities among fresh peripheral blood CD4+ memory T cells, and Th1 vs Th2 memory T cells generated in vitro from purified CD4+ naive precursors by cyclic activation in polarizing culture conditions. Among normal peripheral blood T cells, CLA expression was essentially identical among the IFN-gamma- vs IL-4-producing CD4+ memory subsets, clearly indicating the existence of in vivo mechanisms capable of producing both Th1 vs Th2 skin-homing T cells. In vitro differentiation of naive CD4+ T cells confirmed the independent regulation of CLA and all three cytokines examined, regulation that allowed differential production of IFN-gamma-, IL-4-, and IL-2-producing, CLA+ memory subsets. These studies also 1) demonstrated differences in regulatory factor activity depending on the differentiation status of the responding cell, and 2) revealed CLA expression to be much more rapidly reversible on established memory cells than cytokine synthesis capabilities.

Drug-induced hypersensitivity syndrome (DIHS)/drug rash with eosinophilia and systemic symptoms (DRESS) syndrome is characterized by late disease onset, fever, rash, hepatic dysfunction, haematological abnormalities, lymphadenopathy and often, human herpesvirus (HHV) reactivation. The diagnosis of DIHS is based on the combined presence of these findings. Anticonvulsants are a major cause of DIHS and may also cause Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). We examined whether SJS/TEN due to anticonvulsants display similar clinical and laboratory features seen in DIHS.Patients diagnosed with SJS or TEN due to anticonvulsants (n = 8) were examined and their clinical features and laboratory findings were compared with patients with anticonvulsant-related DIHS (n = 6).Seven of the eight patients with SJS/TEN developed symptoms3 weeks after starting anticonvulsants. Hepatic dysfunction was present in six patients with SJS/TEN and five patients with DIHS. Leucocytosis and/or eosinophilia was noted in seven patients with SJS/TEN and four patients with DIHS. Only one patient in the SJS/TEN group had atypical lymphocytosis; this was present in four patients with DIHS. Reactivation of HHV-6 was detected in one of the four patients tested in the SJS/TEN group, although it was seen in five of the six patients with DIHS.TSJS/TEN due to anticonvulsants may exhibit some clinical and laboratory features of DIHS. The nature of the cutaneous involvement should be emphasized in the diagnosis of DIHS.

A 68-year-old woman presented with a 3-month history of nontender, erythematous nodules on the right side of the neck. Subsequently, tender, circinate erythematous plaques appeared on the limbs, accompanied by peripheral leucocytosis. A biopsy specimen obtained from an erythematous plaque revealed diffuse infiltration of neutrophils in the dermis. Treatment with prednisolone improved the erythematous lesions, but upon tapering of prednisolone, numerous areas of indurated erythema with pustules recurred on the face and back accompanied by high fever. Computed tomography of the lung revealed multiple lesions. A smear of gastric juice contained acid-fast bacilli that were identified as Mycobacterium avium by DNA-DNA hybridization. Treatment with multiple antibiotics did not result in a favourable response of the M. avium infection, and dome-shaped, subcutaneous abscesses developed on the limbs and trunk. Sweet's syndrome may thus occur in association with nontuberculous mycobacterial infection.

We report a patient with psoriasis and hepatitis C virus infection who initially presented with psoriatic erythroderma and eventually showed complete clearance of psoriatic lesions following acute hepatitis induced by etretinate treatment. Cytokine synthesis capabilities in peripheral blood T cells obtained at different stages were evaluated in this patient. A dramatic increase in the frequency of interferon-gamma-producing CD8+ T cells in peripheral blood was observed during the erythrodermic stage. In contrast, the frequencies of interleukin (IL)-4- and IL-13-producing CD4+ T and CD8+ T cells were remarkably high at the resolution stage. These results clearly indicate that a shift towards type 2 cytokine predominance contributes to the resolution of severe psoriasis.

To histologically detect excess aluminum (Al) taken up by bones in a rat model of renal failure prepared by 5/6-nephrectomy, non-decalcified bone tissue sections from specimens of the tibia, femur, rib and ilium were stained with a newly developed lumogallion reagent and examined for aluminum by confocal laser scanning microscopy. The assay revealed that Al contents in the tibia and femur of Al-treated rats tended to be a few-fold higher, compared to controls. With the lumogallion stain technique, Al in bones could be detected and identified at Al concentrations ofor = 9.0 micrograms/g in bone tissues. The reaction of the metal with lumogallion is specific and proved to be positive even at concentrations of excess Al so low as to be undetectable by conventional methods. The present observation disclosed that, unlike the generally accepted view, the Al was accumulated not in the calcification front but was distributed diffusely or as aggregates at high concentration in osteoid tissues. Z mode scans of the slides permitted steric delineation of the state of Al accumulation in bone tissues. The method described herein is considered a useful means for clinical diagnosis of aluminum osteopathy.

Although considerable attention has been paid to the development of cytokine synthesis heterogeneity during memory T cell differentiation, little information is available on how this function is coregulated with homing receptor expression. The development of skin-homing, CD4+ memory T cells in the human provides an excellent model for such investigation, since 1) the skin supports both Th1- and Th2-predominant responses in different settings, and 2) the skin-homing capability of human memory T cells correlates with and appears to depend on expression of the skin-selective homing receptor cutaneous lymphocyte-associated Ag (CLA). In this study, we used multiparameter FACS analysis to examine expression of CLA vs IFN-gamma, IL-4, and IL-2 synthesis capabilities among fresh peripheral blood CD4+ memory T cells, and Th1 vs Th2 memory T cells generated in vitro from purified CD4+ naive precursors by cyclic activation in polarizing culture conditions. Among normal peripheral blood T cells, CLA expression was essentially identical among the IFN-gamma- vs IL-4-producing CD4+ memory subsets, clearly indicating the existence of in vivo mechanisms capable of producing both Th1 vs Th2 skin-homing T cells. In vitro differentiation of naive CD4+ T cells confirmed the independent regulation of CLA and all three cytokines examined, regulation that allowed differential production of IFN-gamma-, IL-4-, and IL-2-producing, CLA+ memory subsets. These studies also 1) demonstrated differences in regulatory factor activity depending on the differentiation status of the responding cell, and 2) revealed CLA expression to be much more rapidly reversible on established memory cells than cytokine synthesis capabilities.

Recent studies have suggested that cytokines play a critical role in the pathophysiology of alopecia areata; however, no information is available regarding the difference in cytokine profiles in these patients. Serum levels of cytokines, including interferon gamma (IFN-gamma), tumor necrosis factor alpha, interleukin 1 alpha (IL-1 alpha), IL-2, IL-4, and IL-6, were measured using radioimmunoassay or enzyme-linked immunosorbent assay techniques in patients with the localized form and the extensive form (alopecia universalis). The serum levels of IL-1 alpha and IL-4 were significantly elevated in patients with the localized form. In contrast, the serum levels of IFN-gamma and IL-2 were significantly elevated in patients with the extensive form. These results indicate that immune responses in the localized form and the extensive form of alopecia areata are regulated by Th2 cytokines and Th1 cytokines, respectively.

The mechanism(s) and the factor(s) that contribute to preferential localization of fixed drug eruption (FDE) lesions to certain skin sites remain speculative. Previous studies suggested that populations of T cells residing in the lesional epidermis may be involved in selective destruction of the epidermis in FDE. In this study, to define the earliest cellular and molecular events with potential relevance to activation of the epidermal T cells, expression of adhesion molecules on keratinocytes (KC) and vascular endothelium was examined sequentially in the lesional skin of FDE patients after challenge with the causative drug. Rapid and intense intercellular adhesion molecule-1 (ICAM-1) expression was induced on the vascular endothelium and KC as early as 1.5 hours after challenge, at which time E-selectin and vascular cell adhesion molecule-1 (VCAM-1) were not up-regulated. In vitro studies using skin organ culture showed that the lesional KC and endothelium responded more rapidly and intensely to express ICAM-1 to tumor necrosis factor-alpha or interferon-gamma compared with those in the nonlesional skin. Surprisingly, such selective induction of KC ICAM-1 restricted to the lesional skin was also observed after exposure to the causative drug alone in skin organ culture. Pretreatment of the lesional skin with anti-tumor necrosis factor completely abrogated in vitro induction of KC ICAM-1 expression by the drug. Drug-induced, TNF-alpha-dependent KC ICAM-1 expression in the lesional skin suggests that induction of ICAM-1 expression by the lesional KC after ingestion of the drug would probably provide a localized initiating stimulus for activation of the disease-associated epidermal T cells.

The localization of spot 35 protein, a cerebellar Purkinje cell-specific protein, was studied in guinea pig taste buds by means of electron-microscopic immunocytochemistry. The immunoreactivity was localized in the cytoplasmic matrix of discrete bud cells. The ultrastructural features of the reactive cells indicated that they corresponded to the Type III or gustatory cells making a synaptic contact with the intragemmal nerves. All other cells specified as basal, Type I, and Type II were immunonegative for spot 35 protein. This finding indicates a method for specifically demonstrating the gustatory cells in the guinea pig taste bud and, further, gives new evidence that paraneurons may share neuron-specific substances with neurons.

We report a patient with scalp lesions of primary localized cutaneous nodular amyloidosis. The extensive examination revealed no systemic involvement. Analysis of glycosaminoglycans (GAGs) in amyloid deposits showed a twofold increase as compared with normal skin, which was due to the increase in dermatan sulfate. Local disorders of GAG metabolism may be related to the amyloid fibril formation. Amyloid fibrils were purified and identified electron-microscopically, which consisted of two major 12,000- and 13,000-dalton and minor 29,000- and 48,000-dalton peptides. Western blotting analysis showed a minor 29,000-dalton peptide reactive with antibodies against both kappa and lambda light chains of immunoglobulin. There is a possibility that some components of amyloid in some cases of primary localized cutaneous nodular amyloidosis may consist of both kappa and lambda immunoglobulin light chains.

Biological effects of such metals as nickel and chromium alloys used as dental materials, particularly their metabolism and potential toxicity have not been well elucidated. Certain metallic materials are known to be toxic and arsenic, nickel, chromium and lead have been shown to have carcinogenic potential in laboratory animals. This study was performed to assess carcinogenicity and accumulation in tissues of metals in rats. Three-week old male F344/NSle rats were injected s. c. with 30 mg/kg of nickel acetate or 60 mg/kg of lead acetate weekly for 5 weeks after 2 weeks of acclimatization, and were followed by observation for 80 weeks. The group treated with lead acetate showed a greater incidence of tumor, compared with the nickel acetate-treated group. Teeth, femora, other bones and neoplastic tissue from tumor-bearing animals were subjected to elemental analysis by spectrophotometry and ICP. High concentrations of Pb were detected in the mandibula, femur and tumor tissue of rats with Pb-induced tumor. In rats with Ni-induced tumor, Ni was not demonstrable in the mandibula, maxilla or tumor tissue and detected in small quantities in the nasal bone and femur. Thus, Pb proved to be retained in tissue at the site of injection and also markedly accumulated in the tooth and femur as assessed 46 weeks after injections; whereas Ni was no longer detectable in tissue at the injection site, nor in tumor tissue but only small quantities in the said bones.

Elemental analyses of the tooth and bone tissues were carried out by X-ray fluorescence element mapping spectrometry, a technique we have recently developed. This analytical system has the advantage of providing data on distribution of element concentration in a given specimen in overhead view without involving destruction of the tissue architecture. This paper briefly introduces the apparatus of this system and presents analytical data obtained for several elements (calcium, iron, arsenic, zinc and strontium) in the tooth and bone tissues of rats bearing tumor induced with lead acetate. Lead distributed in the maxillary incisive bone and femur was demonstrated in rats with lead acetate-induced tumor sacrificed at 42 weeks after injections. Arsenic observed in the femur of control rats was found replaced by lead in the tumor bearing rats. The findings are of interest as viewed with reference to chelating activity of lead.

Elemental analysis of plaque-like black deposits noted on the surface of teeth in zinc-deficient rats at necropsy was performed. Rats deficient in zinc show signs of abnormality in iron metabolism and increase or accumulation of iron in plasma and tissues. This study was designed, therefore, to examine the plasma and salivary levels of iron and other elements and to determine the distribution of mineral elements in the dental substances of zinc-deficient rats by contact microradiography, electron probe microanalysis (EPMA) and X-ray fluorescent element mapping spectrometry (XEMS) on ground sections of teeth. Rat tooth specimens were analyzed also for zinc, iron, copper and manganese using colorimetry and Inductively Coupled Plasma, ICP. EPMA and XEMS analyses revealed the presence of iron on the enamel surface of maxillary molars teeth of zinc-deficient rats. However, no such deposition was seen on those of controls. The zinc-deficient rats showed higher iron concentration in mixed saliva and in plasma, compared with the controls. Thus, the sign of abnormality in iron metabolism noted in the oral cavity of zinc-deficient rats was investigated by EPMA and XEMS analyses, with discussion on the origin of supradental iron deposits.

Guinea pig taste buds were observed by transmission electron microscopy with special reference to cell types and innervation. The taste bud comprised four distinct cell types: basal, type I, type II, and type III cells. Basal cells, residing at the baso-lateral region of the taste bud without extending to the taste pore, were considered precursors of the other types of cells. The rest were all spindle-shaped cells reaching apically to the taste pit. Type I cells were characterized by the darkest appearance of the cytoplasm, apically possessing large, electron-dense granules and basally enveloping intragemmal nerves. This cell type, intervening between the other types of cells, was postulated to be sustentacular in nature. Type II cells, the largest and lightest cells in the taste bud, possessed a conspicuous stack of smooth endoplasmic reticulum above the nucleus. Due to their intimate and specialized relationships with nerves, the type II cells were presumed to receive an efferent innervation. Type III cells made synaptic contacts with nerves and contained dense-cored vesicles, which accumulated in the synaptic areas. This finding strongly suggests a gustatory function for the cells. The occurrence of such numerous peptidergic-type granules gathering to gustatory synapses as demonstrated in this report has not been recorded in previous papers on mammalian taste buds. The nerve terminals on the type III cell also contained synaptic vesicles, thus suggesting a reciprocal synapse here. The taste bud often included degenerating cells which were demonstrated to be phagocytosed by extrinsic cells identified as macrophages.

Differences by routes of administration of the effects of prostaglandins and vasoactive substances on blood pressure, peripheral blood flow and respiration were investigated. Intravenous prostaglandins evoked respiratory excitation in rabbits, and lowered blood pressure more prominently and longer after intracarotid injection than after the intrajugular administration. The effects of prostaglandins were apparently more conspicuous after vertebral artery than via carotid artery. In rats, 1 microgram/kg i.v. of PGE1 and PGE2 caused a fall of blood pressure but 1 microgram/kg i.v. of PGF2 alpha caused a rise. PGF2 alpha produce a decrease of blood pressure when injected 10 micrograms/kg i.v.. A remarkable elevation of blood pressure occurred in rats following injection into the lateral cerebral ventricle of 0.1 microgram/kg of PGE1 or PGF2 alpha or of the same dose of 5-hydroxytryptamine (5-HT). Intra-arterial injection of PGE1 gave rise to an increase in blood flow of rabbit dorsal skeletal muscle whereas that of PGF2 alpha resulted in blood flows. The above results indicate that the effects of prostaglandins on these parameters essentially vary to slight extents with the species of animals and differ in intensity with routes of administration.