Use of dynamic capillaroscopy for studying cutaneous microcirculation in patients with diabetes mellitus

To investigate the relationship between cutaneous microcirculation and retinopathy in diabetes mellitus, we studied by dynamic capillaroscopy 35 diabetes mellitus patients, including 10 patients without retinopathy, 10 patients with background retinopathy, and 15 patients with proliferative retinopathy. We found that (1) cutaneous and retinal microcirculation in diabetes mellitus in long-term diabetes mellitus, regressional rather than proliferational changes occurred in skin vasculature as compared to that in retina; (2) functional impairments of cutaneous microcirculation, that is, decreased resting capillary blood cell velocity, peak blood cell velocity, and prolonged time to peak capillary blood cell velocity by dynamic capillaroscopy, could be detected in diabetes mellitus patients without retinopathy; (3) the degree of tortouosity of capillaries, impairment in peak capillary blood cell velocity, and time to peak capillary blood cell velocity of cutaneous microcirculation were significantly correlated with the gravity of retinopathy in diabetes mellitus patients; (4) abnormal leakage of fluorescence in cutaneous microcirculation appeared in diabetes mellitus patients with or without abnormal fluorescein angiography in retina. In conclusion, dynamic capillaroscopy used in concert with ophthalmoscopy and fluorescein angiography can facilitate a comprehensive examination of vasculopathy in diabetes mellitus.

Live female Enterobius vermicularis in the posterior fornix of the vagina of a Korean woman

A 33-year-old Korean woman, para 2. visited an obstetrics and gynecology clinic, Kumi-shi, Kyongsangbuk-do, due to postcoital spotting and flank pain. She had a tubal ligation 7 years before and demonstrated back pain during menstruation. She revealed a foul smelling discharge without complaint of itching. Enterobius vermicularis eggs were demonstrated during microscopic examination of a smear taken from the posterior fornix of the vagina. On endoscopic examination of her vagina, a live worm was found in the posterior fornix. The worm was removed and identified as a female E. vermicularis based on morphology. This is the first case report of vaginal enterobiasis in Korea.

Effect of growth factors on dermal fibroblast contraction in normal skin and hypertrophic scar

We have examined the effects of four 'exogenous' growth factors, i.e. PDGF-BB (5 ng/ml), TGF-beta1 (5 ng/ml), bFGF (10 ng/ml) and EGF (10 ng/ml) on the contraction of floating collagen type I lattices populated by human normal skin (NS) and hypertrophic scar (HS) fibroblasts (FPCL). Only TGF-beta1 enhanced the contractility of both NS and HS fibroblasts in the collagen lattice (P < 0.01). Other growth factors (PDGF-BB, bFGF and EGF) did not affect FPCLs contraction at 72 h (P > 0.05). The onset effect of TGF-beta1 on NS-FPCL contraction was relative early at 24 h after FPCL casting as compared to a 72 h delay on HS-FPCL contraction. Besides, PDGF-BB was found to be able to enhance HS-FPCL contraction (P < 0.05) but not on NS-FPCL contraction on day 4. On the other hand, three enzyme-linked immunosorbent assays (ELISA) were performed to demonstrate quantitatively the 'endogenous' growth factors that fibroblasts secreted into the culture medium 48 h after FPCL casting. No appreciable difference was found between 10 NS and 11 HS samples tested for PDGF-AB immunoassay (11.48 +/- 5.5 pg/ml versus 12.20 +/- 5.34 pg/ml). The same result existed in 7 NS and 13 HS samples for TGF-beta2 immunoassay (15.15 +/- 6.2 pg/ml versus 11.84 +/- 7.46 pg/ml). In bFGF immunoassay study, relative variable data was noted in both 7 NS (18.18 +/- 13.18 pg/ml) and 12 HS samples (20.41 +/- 22.36 pg/ml). In conclusion, we suppose that TGF-beta role in wound healing may be due to the secondary exogenous influences. The endogenous ability of TGF-beta2 secretion (quantity) in HS fibroblasts are the same as NS fibroblasts but with delayed timing responses (quality) to exogenous TGF-beta1 effect in the collagen lattice. Further studies with timing-regulated selective specific monoclonal antibodies against the growth factor receptors may provide the therapeutic applications on HS during wound healing.

The inhibitory effect of UVB irradiation on the expression of p53 and Ki-67 proteins in arsenic-induced Bowen's disease

The aim of this study is to evaluate the effect of ultraviolet B (UVB) on arsenic-induced Bowen's disease. Four patients were irradiated with 750 mJ/cm2 of UVB and biopsies were performed before treatment and 2 weeks later. Immunohistochemical stains of p53 and Ki-67 were compared by the labelled-streptavidin method before and after the UVB treatment. We found that the number of p53 and Ki-67 positive cells after the UVB treatment were significantly fewer than those of non-UVB-treated specimens. These results suggest that the UVB inhibitory effect in Bowen's disease needs further studies to clarify its value in potentially retarding the progression of the hyperproliferative status in overt skin cancer on a molecular basis.

Tamm-Horsfall glycoprotein (THG) is a binder for surface membrane proteins on blood cells and glomerular mesangial cells

A macromolecule with a molecular weight of 90-100 kDa was purified from normal human pregnancy urine. The molecule was proved to be the Tamm-Horsfall glycoprotein (THG) by Western blot analysis. The macromolecule contains carbohydrate as detected by an enzyme immunoassay. Functionally, the glycoprotein can adhere to and stimulate the thymidine incorporation of human mononuclear cells (MNC) in modest degree via its membranotropic property. In addition to MNC, the protein can also bind to the surface of human polymorphonuclear neutrophils (PMN), red blood cells (RBC) and rat glomerular mesangial cells (RMC). Western blot analysis of various cell lysates with/without proteinase K pretreatment before cell lysis revealed that a 60 kDa and a molecule larger that 94 kDa on the surface of PMN, a 60 kDa protein on MNC and a 32 kDa protein on RBC are the binding molecules for THG. In contrast, many proteins on the surface of RMC could be bound by THG. Immunoprecipitation of membranous iodinated MNC lysates also confirmed that the 60 kDa molecule on MNC is the binding protein for THG. A number of monosaccharide including N-acetylneuraminic acid, N-acetyl-galactosamine, N-acetyl-glucosamine and alpha-methyl-D-mannoside could not inhibit the mitogenic effect of THG on human mononuclear cells. These results suggest that THG is capable of reacting with surface membrane proteins on different cells, but not through the specific carbohydrate-containing lectin-like receptors on the cell surface.

Close relatedness of Acanthamoeba pustulosa with Acanthamoeba palestinensis based on isoenzyme profiles and rDNA PCR-RFLP patterns

The taxonomic validity of morphological group III Acanthamoeba spp. is uncertain. In the present study, six type strains of group III Acanthamoeba spp., A. culbertsoni, A. healyi, A. pustulosa, A. palestinensis, A. royreba and A. lenticulata were subjected for the evaluation of their taxonomic validity by comparison of the isoenzyme patterns by isoelectic focusing on polyacrylamide gels, mitochondrial DNA (Mt DNA) restriction fragment length polymorphism (RFLP), and small subunit ribosomal DNA (ssu rDNA) PCR-RFLP patterns. The Mt DNA RFLP patterns were heterogeneous between the species. The type strains of A. palestinensis and A. pustulosa showed almost identical patterns of isoenzymes and rDNA PCR RFLP with an estimated sequence divergence of 2.6%. The other species showed heterogeneous patterns of isoenzymes and rDNA PCR-RFLP. It is likely that A. pustulosa is closely related with A. palestinensis and that the former may be regarded as a junior synonym of the latter.

Low-energy helium-neon laser irradiation stimulates interleukin-1 alpha and interleukin-8 release from cultured human keratinocytes

Clinical observations have suggested that low-energy lasers might promote wound healing. Evidence suggests that He-Ne laser irradiation induces an increase in the rate of keratinocyte migration and proliferation as compared with nonirradiated controls in vitro. This study sought to determine whether He-Ne laser could induce cytokine production in cultured keratinocytes. The results revealed (i) a significant increase in interleukin-1 alpha and interleukin-8 production and their respective mRNA expression in He-Ne laser-treated groups as compared with nonirradiated controls, and (ii) under 1.5 joules/cm2 irradiation, this stimulating effect of He-Ne laser treatment is concentration-dependent. Because interleukin-1 alpha induces keratinocyte migration, this finding may partially explain the stimulatory effects on the motility of keratinocytes. As both interleukin-1 alpha and interleukin-8 provoke proliferation of keratinocytes, it is not unreasonable to propose that these two cytokines play a profound role in the enhancement of keratinocyte proliferation as a result of He-Ne laser irradiation. Our findings provide further evidence of enhanced wound healing at the cellular and molecular level as a result of the He-Ne laser.

[The study on the in-vitro stability of Tc(V)-99m dimercaptosuccinic acid]

Tc(V)-99m DMS, developed by Yokoyama et al. in 1981, has been recognized to be advantageous for the scintigraphic diagnosis of various malignant tumors and their metastasis, the aim of this study is to assess the in-vitro stability of Tc(V)-99m DMS. Thin-layer chromatography, including paper chromatography and silica gel thin layer chromatography, is performed to determine the change of radiochemical species presented in the reconstituted solution of Tc(V)-99m DMS prepared from the DMS kit (Institute of Nuclear Energy Research, Atomic Energy Council R.O.C.) and the commercial DMSA kit (Nephroscint, IRE CELLTARG Radiopharmaceuticals Japan). The bioscan imaging scanner is used to measure the Rf value and labeling efficiency of radiochemical species on the chromatographic strip. The in-vitro stability of Tc(V)-99m DMS prepared from the DMS kit and the commercial DMSA kit is studied by examining various parameters which include temperature(degree C) and time(hr) after reconstitution. The results show that the in-vitro stability of Tc(V)-99m DMS prepared from the DMS kit is actually better than that from the commercial DMSA kit. The one-step labeling method of DMS kit is much simpler than the two-step labeling method of DMSA kit.

The β-adrenoceptors and catecholamine levels in lead poisoned rats

To investigate β-adrenoceptor dysfunction upon exposure to lead, we measured (a) β-adrenoceptor density in brain, heart, blood vessels and lymphocytes and (b) plasma catecholamine levels in rats with lead poisoning. Wistar rats were given drinking water containing lead acetate (2% w/v) for a period of 60 days. The radioligand [(125)I]iodocyanopindolol was used for determining the density of β-adrenoceptors in membrane fragments in vitro and a high performance liquid chromatography (HPLC) for measuring plasma catecholamine levels. Plasma norepinephrine levels were found to be significantly higher in lead-exposed rats than in control animals (4.69 ± 0.58 μg/l vs. 3.67 ± 0.53 μg/l, p < 0.01). In lead-exposed animals the density of β-adrenoceptors in brain (36%), heart (68%), blood vessels (57%) and lymphocytes (48%) was significantly less than in controls (p < 0.001), whereas the K(d) did not vary between the two groups. We have found that β-adrenoceptor dysfunction in lead-poisoned rats was brought about by a decline in β-adrenoceptor density.

The characteristics in the inhibitory effects of capsaicin on voltage-dependent K(+) currents in rat atrial myocytes

The electrophysiological effects of capsaicin in rat atrial myocytes were examined. Measurement of contractile force was done in rat left atria. Whole-cell patch-clamp technique was primarily used to study the change in membrane potential and ionic currents. Capsaicin produced an initial rise and a sustained increase in contractile force in rat left atria. Capsaicin (10 μM) caused a significant prolongation of atrial action potential. In voltage-clamp experiments, capsaicin (1-100 μM) caused the reversible reduction in the amplitude of transient outward (I(TO)) and late outward (I(L)) K(+) currents in concentration- and voltage-dependent manners. The time course for inactivation of I(TO) was changed to the biexponential process after the application of capsaicin. Capsaicin failed to cause any significant shift in quasi-steady-state inactivation curve of I(TO). The EC(50) values for the inhibitory effects of capsaicin on I(TO) and I(L) were 5 and 20 μM, respectively. Capsaicin also suppressed the amplitude of acetylcholine- or adenosine-induced K(+) current, i.e., I(K(ACh,Ado)). The EC(50) value for capsaicin-mediated inhibition of I(K(ACh,Ado)) is 50 μM. The present findings suggest that in isolated rat atria, during capsaicin exposure, the capsaicin-mediated inhibition of these K(+) channels is one of the ionic mechanisms underlying the positive inotropic and chronotropic actions.

Fiberglass dermatitis: a case report

Glass fibers are the most widely distributed mineral fibers because of their multiple applications, chiefly as insulation materials, and have become important in replacing asbestos fibers. Fiberglass dermatitis is one of the most common forms of occupational dermatitis resulting from mechanical irritation. Here we report a typical case. A 30-year-old male worker handled the cutting and grinding of fiberglass mats and then mixed them with resin as reinforcing materials. He complained of intense itching after the first two weeks of employment. Erythematous macules, papules and folliculitis with excoriation developed over his arms, neck, face and upper chest. There were many transparent glass fiber spicules with the diameter around 7-10 microns detected by applying the adhesive tape against the skin lesion, followed by microscopic observation. He was much improved during hospitalization with oral antihistamine and topical steroid ointment. To prevent this occupational disease, we suggest proper procedures of production, storage, transportation and cleaning in the industrial setting and proper protective clothing in personnel to minimize the release of and exposure to glass fibers.

The cytotoxic effect of neonatal lupus erythematosus and maternal sera on keratinocyte cultures is complement-dependent and can be augmented by ultraviolet irradiation

To elucidate the role of autoantibodies and ultraviolet (UV) exposure in the pathogenesis of the skin lesions in neonatal lupus erythematosus (NLE), keratinocytes were cultured, as the target cells, from a patient with NLE and from a normal neonate. We demonstrated that the expression of nuclear/cytoplasmic Ro/SSA and La/SSB molecules on to the surface of NLE keratinocytes occurred to a much greater extent than that on normal keratinocytes. A dose of 200 mJ/cm2 UVB irradiation on NLE keratinocytes induced a 2.5-3-fold increase in Ro/SSA and La/SSB expression compared to non-irradiated cells. Sera derived from both the NLE patient and from his mother exhibited a cytotoxic effect on NLE keratinocytes, but not on control cells, in the presence of complement. Furthermore, the cytotoxicity of the sera was enhanced on UVB-irradiated NLE keratinocytes, whereas it had no cytotoxic effects on UVB-irradiated control cells. This suggests that the abnormal expression of both Ro/SSA and La/SSB on the surface membrane of NLE keratinocytes induces the autoantibodies and complements to injure the cells. This complement-mediated cytotoxic effect can be augmented by UV irradiation, a concept not incompatible with the exacerbation of the skin eruption in sun-exposed skin sites.

Lymphocyte beta2-adrenergic receptors and plasma catecholamine levels in lead-exposed workers

The effect of lead exposure on beta2-adrenoceptor density and catecholamine response was studied in 26 male workers and 1 female worker, exposed to lead on average for 6 years. The systolic blood pressure in lead workers (101-160 mmHg, 124.4 +/- 14.7 mmHg) was found to be significantly higher than in controls (97-134 mmHg, 115.4 +/- 10.4 mmHg, p < 0.01) as was plasma norepinephrine (0.51 +/- 0.1 microg/liter vs 0.24 +/- 0.05 microg/liter, p < 0.01). The density of lymphocyte beta2-adrenergic receptors (Bmax) in lead-exposed workers was 86% lower than that in controls (0.15 +/- 0.08 vs 1.08 +/- 0.29 fmol/0.1 x 10(6) cells; p < 0.01). The dissociation constants (Kd) of [125I]iodocyanopindolol were 93.6 +/- 42.6 and 87.9 +/- 42.7 pM in lead-exposed workers and controls, respectively. Multiple linear regression analysis showed that elevation of systolic pressure was closely related to (a) blood lead levels, (b) decreased beta2-adrenergic receptor density, and (c) increased plasma catecholamine levels in lead-exposed workers. Linear regression analysis revealed that both plasma norepinephrine levels and beta2-adrenoceptor density (Bmax) were highly correlated with both systolic blood pressures and blood lead levels in lead-exposed workers, and a highly significant negative correlation was found to exist between Bmax and plasma norepinephrine levels (r = -0.82, p < 0.001). These data therefore demonstrate that there is a close relationship between elevated plasma catecholamine levels, decreased beta2-adrenergic receptors, and elevated blood pressure in lead-exposed workers.

Effects of acetylcholine and carbachol on bovine corneal endothelial cells in vitro

PURPOSE

To assess the relative cytotoxicity of Miochol (1% acetylcholine and mannitol), Miostat (0.01% carbachol, sodium, potassium, magnesium, and calcium salts), and their individual components using in vitro models of bovine corneal endothelial cells (BCECs).

SETTING

Laboratories of the Departments of Ophthalmology and Physiology, The University of Texas Health Science Center, Houston.

METHODS

The study was divided into four experiments. Experiment 1 used a confluent model to compare the relative cytotoxicity of Miochol and Miostat on BCECs following short-term exposure. In Experiments 2, 3, and 4, the proliferation model (preconfluent BCECs) was used to detect the possible cytotoxicity of individual components in the commercial preparations of the miotics; i.e., the preconfluent BCECs were exposed to buffered salt solutions containing mannitol (1%, 3%, and 4%), acetylcholine (0.5%, 1%, and 2%), or carbachol (0.1%, 0.5%, and 1%) for 3 hours.

RESULTS

Confluent BCECs exposed to Miochol for 30 minutes underwent necrosis and degeneration, while those treated with Miostat did not show any morphological changes. None of the tested solutions except 2% acetylcholine and 1% carbachol caused observable changes in the nuclear densities of BCECs at 24, 72, 120, and 168 hours.

CONCLUSION

The major components of Miochol (acetylcholine and mannitol) were found to be nontoxic; the cytotoxicity of the preparation was possibly due to the lack of an appropriate balanced salt solution. These findings may influence the selection of a miotic for use during intraocular surgery.

Biochemical and molecular characterization of a strain KA/S2 of Acanthamoeba castellanii isolated from Korean soil

A strain, KA/S2, isolated from Korean soil and morphologically assigned to Acanthamoeba castellanii, was characterized by isoenzyme analysis, and total proteins profile, and mitochondrial (Mt) DNA restriction fragment length polymorphism (RFLP), and compared with four reference strains assigned to the species (the authenitic Castellani, Neff, Ma, and Chang strains). It was found that four isoenzyme, total proteins, and Mt DNA RFLP patterns by eight restriction endonucleases of the strain KA/S2 were identical with those of the Neff strain, isolated from soil of California, USA. The Chang strain was unique in its morphology and total protein patterns. Interstrain polymorphisms of isoenzyme profiles and Mt DNA RFLP patterns were observed among the Castellani, Neff, Ma, and Chang strains. Mt DNA RFLP was confirmed to be highly appropriate for the strain characterization and identification of Acanthamoeba spp.

The reactivity of sera from patients with systemic lupus erythematosus to seven different species of single and double stranded deoxyribonucleic acids

OBJECTIVE

Anti-DNA antibodies are frequently found in the serum of patients with systemic lupus erythematosus (SLE). To understand whether the avidity of SLE sera to different species of single-stranded (ss) and double-stranded (ds) DNA is different or not, the reactivity of active SLE sera to seven species of DNA from viral, bacterial, piscine, and mammalian sources was compared.

METHODS

Nineteen sera from patients with active SLE were studied for their reactivity to different ssDNA and dsDNA from Escherichia coli (EC), Micrococcus lysodeikticus (ML), Clostridium perfringens (CP), calf thymus (CT), salmon testis (ST), human placenta (HP) and lambda phage by ELISA. The dsDNA was purified by treating it with S1 nuclease and proteinase K, followed by Sephacryl S-300 gel filtration. The ssDNA was purified by absorption on a hydroxyapatite column after heat-cleavage of the dsDNA.

RESULTS

The reactivity of SLE sera to 7 species of dsDNA was not significantly different and they recognized a more widely shared epitope. In contrast, the reactivity of these sera to 7 species of ssDNA was erratic and the antigens could be grouped into high (CP and HP), medium (EC, ML, CT, and ST) and low (lambda-phage) antigenicities.

CONCLUSION

The anti-ssDNA and anti-dsDNA antibodies of SLE patients recognize more widely shared determinants on the DNA of seven different species. Lambda-phage DNA shows the poorest immunogenicity among them.

The expression of cytokines by an established basal cell carcinoma cell line (BCC-1/KMC) compared with cultured normal keratinocytes

A basal cell carcinoma (BCC) cell line (BCC-1/KMC) has recently been successfully established from a patient. The production of interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-6 and IL-8 was assessed in comparison with that of cultured normal keratinocytes. The mRNA expression of these cytokines was measured by a reverse transcriptase-polymerase chain reaction (RT-PCR) method and the protein production by an ELISA. The cultured BCC cells spontaneously secreted more IL-6 and IL-8 but less IL-1 than the keratinocytes after culture for 24 h at 37 degrees C. It is suggested that the increased expression of IL-6 and IL-8 may indicate the transformation of normal keratinocytes to locally aggressive BCC.

Deterioration of cutaneous microcirculatory status and its clinical correlation in tetralogy of Fallot

The purpose of this study was to evaluate the hemodynamic deterioration in cutaneous microcirculation and its clinical correlation in patients with tetralogy of Fallot (TF). Laser Doppler flowmetry and capillary microscopy were used to assess thermoregulatory and nutritional microcirculation, respectively. A significant increase in blood flow in thermoregulatory vessels was noticed only in TF patients with hemoglobin (Hb) levels under 19 g/dl. In patients with Hb levels above 19 g/dl, the blood flow declined into the normal range. This result indicated an extreme decrease of blood flow velocity in the thermoregulatory vessels in patients with Hb concentration higher than 19 g/dl. All TF patients with Hb concentrations higher than 19 g/dl revealed Maricq's type III capillaries. Type III capillaries revealed a significant retardation of capillary blood cell velocity (CBV). There was a reciprocal relationship between CBV and hematocrit (Hct). All the responses of the cutaneous microcirculation revealed a good correlation with the clinical severity of TF. All patients with type III capillaries (with Hb concentrations higher than 19 g/dl or Hct level higher than 60%) indicated an advanced disease progression. Laser Doppler flowmetry and capillary microscopy provide a sensitive noninvasive approach for the evaluation of the hemodynamic disturbances in TF and conditions resulting from long-term hypoxia.

Analytical studies of spontaneous and vasopressin-induced calcium oscillations in cultured vascular smooth muscle cells

Spontaneous and vasopressin-induced Ca2+ oscillations in cultured vascular smooth muscle (A7r5) cells were further examined and characterized. Intracellular Ca2+ concentrations ([Ca2+]i) were measured by use of a high-performance laser cytometer. When the oscillatory patterns in [Ca2+]i were analyzed with a power spectrum method, about 80% of cells exhibited spontaneous Ca2+ oscillations with the frequency of 0.02-0.5 Hz. Nifedipine abolished these repetitive spikes, whereas pinacidil partially attenuated their amplitude and frequency. When vasopressin (100 nM) was applied to A7r5 cells, there was an initial rise in [Ca2+]i, followed by a delayed sustained increase in [Ca2+]i. The one-pool, nonoscillatory model was employed to fit this biphasic change, and the difference between the observed response and the simulated response was then analyzed with a power spectral method. About 50% of cells were noted to display oscillatory patterns in [Ca2+]i after sustained increase in [Ca2+]i. The present study indicates that spontaneous Ca2+ oscillations in A7r5 cells are modulated by the activity of ATP-sensitive K+ channels and are not related to pertussis toxin-sensitive GTP-binding protein(s). On the basis of the one-pool, nonoscillatory model, it is suggested that the buffering capacity of internal stores appears to be stronger in the cells with spontaneous Ca2+ oscillations than in those in a quiescent state, and the vasopressin-mediated inhibition of accumulation by internal stores was attenuated when the cells exhibited spontaneous Ca2+ oscillations. The implementation of this minimum kinetic model integrated with a power spectrum method would be an alternative to understand the oscillating behavior in [Ca2+]i.

Production of the third component of complement (C3) by peripheral polymorphonuclear neutrophils of the patients with rheumatoid arthritis

Normal human polymorphonuclear neutrophils (PMN) can spontaneously produce the third component of complement (C3) in in vitro culture as detected by ELISA. This C3-producing capacity of PMN can be augmented by TNF-alpha (20 ng/ml) and bacterial lipopolysaccharide (100 ng/ml), but not by IL-1 beta or IL-8. The C3 production by PMN was found to be temperature dependent and was suppressed by the addition of protein inhibitor. The C3 mRNA in PMN could be detected by reverse transcription assisted polymerase chain reaction (RT-PCR) after TNF-alpha or LPS stimulation for 6 hours. To further understand C3 production by peripheral blood PMN in rheumatoid arthritis (RA), spontaneous and TNF-alpha stimulated production of C3 by peripheral PMN were compared in 15 cases of active RA, 15 inactive RA and 15 normal individuals. We failed to find any significant difference among the three groups. We conclude that PMN plays a negligible role in C3 hypercomplementemia in patients with active RA.

Defective spontaneous and bacterial lipopolysaccharide-stimulated production of interleukin-1 receptor antagonist by polymorphonuclear neutrophils of patients with active systemic lupus erythematosus

Interleukin-1 receptor antagonist (IL-1ra) binds competitively to IL-1 receptors but does not transduce the signal which blocks the biological activities induced by IL-1. In this study, polymorphonuclear neutrophils (PMN) and mononuclear cells (MNC) from the patients with active systemic lupus erythematosus (SLE) (n = 11), inactive SLE (n = 13) and normal individuals (n = 13) were compared for the IL-1ra producing capacity of these cells. PMN and MNC at a concentration of 1 x 10(6) cells/ml were incubated with medium alone (spontaneous) or stimulated with lipopolysaccharide (LPS, 100 ng/ml) for 24 h. The IL-1ra concentration in the supernatants was quantified by ELISA method. Both spontaneous and LPS-stimulated production of IL-1ra by PMN, but not by MNC, of active SLE were significantly lower than that of inactive SLE or normal groups. Prednisolone (1 and 5 micrograms/ml) did not change the production of IL-1ra by normal PMN either spontaneously or LPS-stimulation in in vitro study. Moreover, the IL-1ra producing capacity of PMN in seven active SLE on admission and after intensive immunosuppressive treatment was measured. These results suggest that the defective IL-1ra production by SLE-PMN is relevant to disease activity and may be regarded as a new indicator of disease activity in patients with active SLE.

Abnormal splenic and thymic IL-4 and TNF-alpha expression in MRL-lpr/lpr mice

The MRL-lpr/lpr and MRL-(++) mice were studied for the expression of cytokines in the spleen, lymph node, thymus, kidney and brain through the reverse transcription-polymerase chain reaction (RT-PCR). The frequencies of IL-4 and TNF-alpha expression in the thymus and spleen were significantly higher in MRL-lpr/lpr mice than in MRL-(++) mice from the age of 17 to 32 weeks. More importantly, IL-4 transcript was demonstrated in the early rather than in the terminal stage of the lupus disease. At the 20th week, MRL-lpr/lpr mice with active disease exhibited higher concentrations of IL-1 alpha, IL-6 and TNF-alpha in serum than MRL-(++) mice. Interestingly, in MRL-lpr/lpr but not MRL-(++) mice, the IL-6 concentration in cultured supernatants of the thymic cells was significantly higher than that of the splenic or lymph node cells. On the other hand, IL-6 and IL-1 beta were expressed in the brain and kidney of MRL-lpr/lpr mice but not of MRL-(++) mice. Cultured MRL-lpr/lpr mesangial cells could also express IL-6 but to a lesser extent. These results suggest that the abnormal splenic and thymic IL-4 and TNF-alpha expression may predispose the development of autoimmune reactions. The expression of IL-1 beta and IL-6 in the brain and kidney may be implicated in the damage of these two organs in MRL-lpr/lpr mice.

Induction of Ca2+ oscillations by vasopressin in the presence of tetraethylammonium chloride in cultured vascular smooth muscle cells

The change of cytosolic Ca2+ concentration ([Ca2+]i) caused by vasopressin was examined in indo-1-loaded A7r5 smooth muscle cells by use of the high-performance laser cytometer and ratiometric fluorescence method. Vasopressin (100 nM) caused an initial rapid rise and a delayed increase in [Ca2+]i (n = 6). However, in the presence of tetraethylammonium chloride (10 mM), vasopressin consistently triggered sustained Ca2+ oscillations which were preceded by a large peak of [Ca2+]i. The latency for the development of this huge increase in [Ca2+]i prior to the occurrence of sustained Ca2+ oscillations was always the same. The frequency and amplitude of this type of Ca2+ oscillation varied depending upon the extracellular Ca2+ concentration. Ca(2+)-free solution did not completely suppress the sustained Ca2+ oscillations, but caffeine (20 mM) effectively abolished them. The present findings indicate that in A7r5 smooth muscle cells, the sustained Ca2+ oscillations triggered by vasopressin in the presence of tetraethylammonium chloride were mainly due to Ca2+ release from IP3-sensitive Ca2+ stores and Ca2+ influx from extracellular space, and did not require the pacemaker activity derived from the surface membrane. Moreover, the vasopressin-induced change in [Ca2+]i appeared to be linked to pertussis toxin-insensitive GTP-binding protein(s).