Prevention of type I diabetes with lymphotoxin in BB rats

We previously reported that nonspecific immunomodulations with a streptococcal preparation (OK-432), an inducer of tumor necrosis factor (TNF), or with recombinant TNF prevented development of insulin-dependent diabetes mellitus (IDDM) in animal models (NOD mice and BB rats). Recently we have further reported that lymphotoxin (LT), a cytokine with functional and structural characteristics similar to those of TNF, also protected NOD mice from diabetes. In this study, we have extended our observation on the LT to BB rats. Male and female BB/Wor rats were treated intraperitoneally with recombinant human LT three times a week from 4 to 11 weeks of age. The cumulative incidence of diabetes by 14 weeks of age was 24/30 (80.0%) in nontreated control rats, whereas it was 10/26 (38.5% vs control, P < 0.01) and 4/29 (13.8% vs control, P < 0.0001) in the rats treated with 1 x 10(3) and 1 x 10(4) of LT, respectively. There was no significant difference in nonfasting blood glucose levels and body weights between nontreated control and LT-treated rats, which were nondiabetic. In the LT-treated rats, intensity of insulitis was significantly reduced in comparison with the nontreated rats. Concanavalin A-stimulated TNF/LT productivity of spleen cells was significantly lower in BB/Wor and BB/Sendai rats than in Wistar rats or other normal rat strains. On the other hand, there was no difference between BB/Sendai and Wistar rats in the in vivo TNF/LT productivity induced with LPS or with IFN-gamma plus LPS, and the TNF/LT productivity of these rats was lower on stimulation with LPS alone, but higher with IFN-gamma plus LPS than the other normal rats. These results indicate that treatment with LT, as well as TNF, modulated autoimmunity and prevented development of IDDM in BB/Wor rats which may be low producers of TNF/LT.

Dose response for TCDD promotion of hepatocarcinogenesis in rats initiated with DEN: histologic, biochemical, and cell proliferation endpoints

The present study examines the dose-response relationship for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) promotion of histologic and biochemical parameters by using a two-stage model for hepatocarcinogenesis in female Sprague-Dawley rats initiated with a single intraperitoneal dose of 175 mg of diethylnitrosamine (DEN)/kg body weight at 70 days of age. Starting 2 weeks after initiation, treatment groups of 8-10 rats were given TCDD by gavage in corn oil once every 2 weeks for 30 weeks. Doses were 3.5, 10.7, 35.7, and 125 ng TCDD/kg body weight/day. A significant body weight reduction was present in the noninitiated group that received 125 ng TCDD. Relative liver weight was statistically increased in initiated rats treated with > or = 10.7 ng TCDD and in noninitiated rats treated with > or = 35.7 ng TCDD. Histopathologic evidence of cytotoxicity was dose-related in all TCDD-treated groups. There was a statistically significant dose response in the bromodeoxyuridine (BrdU) S-phase labeling index (LI) in the DEN-initiated rats (p < 0.01) and a marginally significant trend in the saline-treated rats (p = 0.10), but proliferating cell nuclear antigen S-phase LI and growth fraction within altered hepatic foci showed no increase. Among the DEN-initiated groups there was a significant increase in glutathione S-transferase altered hepatic foci stereological parameters in the 125 ng TCDD group. This study demonstrates that dose-response relationships for TCDD's effects on cell proliferation growth of altered hepatic foci are different from previously reported effects on P450 gene expression, indicating that different biological or biochemical responses may exhibit different dose-response relationships.(ABSTRACT TRUNCATED AT 250 WORDS)

[Predicting the clinical efficacy of house dust mite immunotherapy in bronchial asthmatics by multiple quantification analysis type II]

To predict the clinical efficacy of house dust mite immunotherapy (IT) for bronchial asthma, clinical factors before IT were analyzed in relation to clinical efficacy. The factors analyzed were severity, skin test threshold, age at which IT was started, duration of asthma, onset of asthma, FEV1.0%, serum IgE levels before IT, the presence of allergens other than HD, family history of atopic disease, complications with other allergic diseases, sex, seasonality of attacks and the maintenance dose. The clinical efficacy ranging from good response to no benefit was well discriminated by this analysis. The rate of discrimination was about 90%, indicating clinical usefulness of the method. In this study, skin test threshold seemed to be the most important factor, followed by FEV1.0%. While severity and age have been reported to be important, those who show good FEV1.0% and low skin test threshold, regardless of their severity or age, may be good candidates for IT.

Methylprednisolone therapy in laser injury of the retina

The efficacy of methylprednisolone in argon-laser-induced retinal injury in primates was evaluated by clinical, histopathologic, and morphometric criteria. Methylprednisolone was given with a loading dose of 30 mg/kg followed by 5.4 mg/kg per hour in three different regimens: (1) starting 24 h before laser and continuing for 4 days; (2) starting immediately after laser and continuing for 4 days; and (3) starting immediately after laser and continuing for 8 h. Fundus photography, fluorescein angiography, and histologic examination showed significant beneficial effects of all three treatments compared to controls. Morphometrically, at the center of the lesion, the width of disrupted outer nuclear layer, the width of the affected RPE, and the percentage of residual photoreceptor nuclei confirmed the efficacies of treatment regimens 1 and 2, but not treatment regimen 3.

Molecular cloning of a novel angiotensin II receptor isoform involved in phosphotyrosine phosphatase inhibition

There are two major isoforms of the angiotensin II receptor, type 1 (AT1) and type 2 (AT2). AT2 is distinguished from AT1 with respect to its ligand selectivity, its insensitivity to non-hydrolyzable GTP analogues, and its as yet unidentified biological functions. In the present study we have expression-cloned AT2 cDNA from a cDNA library of a rat pheochromocytoma cell line (PC12w). Rat AT2 cDNA encodes a 363-amino acid protein that has seven transmembrane domains. AT1 is the closest in homology to AT2 but with only a 32% identity of amino acid sequence. Stably expressed in COS-7 cells, the receptor showed selective binding to AT2-specific ligands PD123319 and CGP42112A but not to the AT1-specific ligand, losartan. Northern blot analysis revealed that the mRNA of rat AT2 was expressed not only in PC12w cells but also in the adrenal glands and in the inferior olive of the brain, both of which are known to contain AT2 type binding sites. The expressed AT2 receptor mediated angiotensin II-induced inhibition of protein tyrosine phosphatase, an action that was dependent on a pertussis toxin-sensitive G-protein-coupled mechanism in COS-7 cells. The AT2-specific ligand CGP42112A was an agonist rather than antagonist in the inhibition of phosphotyrosine phosphatase. AT2 did not cause a decrease in cGMP in PC12w or COS-7 cells expressing AT2 stably. These results indicate that the AT2 receptor is structurally and functionally different from AT1 and suggest novel functional roles of the renin-angiotensin system in cross-talk with phosphotyrosine signaling by modulating protein phosphotyrosine levels.

Pituitary adenylate cyclase activating polypeptide (PACAP)-like immunoreactivity in ganglioneuroblastoma and neuroblastoma

Pituitary adenylate cyclase activating polypeptide (PACAP) is a 38 amino acid peptide originally isolated from ovine hypothalamus. It has a potent stimulatory action on adenylate cyclase in the rat pituitary. The presence of PACAP was studied in the tumor tissues of ganglioneuroblastoma and neuroblastoma by radioimmunoassay and immunocytochemistry. Immunocytochemical studies showed positive immunostaining in 4 out of 7 ganglioneuroblastomas and 4 out of 6 neuroblastomas. Immunoreactive PACAP concentrations in tissues of 3 ganglioneuroblastomas ranged from 14.5 to 27.8 pmol/g wet weight (20.0 +/- 5.7 pmol/g wet weight, mean +/- S.D.) and the concentration in one neuroblastoma tissue was 111.0 pmol/g wet weight. Reverse phase high performance liquid chromatography of the tumor tissue extract of ganglioneuroblastoma showed a peak eluting in the position of PACAP1-38 and smaller broad peaks eluting later. These results indicated that high concentrations of immunoreactive PACAP were present in the tumor tissues of ganglioneuroblastoma and neuroblastoma, and suggest the possibility that this peptide plays a pathophysiological role in some ganglioneuroblastomas and neuroblastomas.

CD-832, a new dihydropyridine derivative with both nitrate-like and Ca2+ channel antagonist vasodilator activities

We investigated the effects of CD-832 ((4R)-(-)-2-(nicotinoylamino)ethyl 3-nitroxypropyl 1,4-dihydro-2,6-dimethyl-4,3-nitrophenyl, 3,5-pyridine dicarboxylate), a new dihydropyridine derivative with nitrate ester, on contraction and relaxation responses induced by various vasoactive agents in rabbit aorta. CD-832 potently inhibited the specific binding of [3H](+)-PN200-110 to rat brain membranes. The IC50 values for [3](+)-PN200-110 binding were 2.8 nM and 4.9 nM in CD-832 and nifedipine, respectively. CD-832 (10(-8) to 10(-5) M), diltiazem (10(-8) to 10(-5) M) and benidipine (10(-8) to 10(-5) M) inhibited the 64 mM KCl-induced contraction of the aortic strips in a concentration-dependent manner. Neither nitroglycerin (10(-8) to 10(-5) M) nor nicorandil (10(-8) to 10(-5) M) affected the 64 mM KCl-induced contraction in rabbit aorta. CD-832 (10(-8) to 10(-5) M), nitroglycerin (10(-8) to 10(-5) M) and nicorandil (10(-5) M) had no effect on norepinephrine-induced contraction in rabbit aorta. Nitroglycerin (10(-5) M), atrial natriuretic peptide (10(-8) M), nicorandil (10(-5) M) and CD-832 (10(-7) to 10(-5) M) augmented the isoproterenol-induced relaxation responses of rabbit aorta precontracted with endothelin-1 (1 x 10(-7) to 2 x 10(-7) M). The effects of nitroglycerin (10(-5) M), nicorandil (10(-5) M) and CD-832 (10(-5) M) on isoproterenol-induced relaxation responses were antagonized by treatment with methylene blue (10(-5) M) and oxyhemoglobin (10(-5) M).(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma androgens and sex hormone binding globulin in women with polycystic ovaries diagnosed by transvaginal ultrasound

In order to investigate the androgen and sex hormone binding globulin (SHBG) levels in the polycystic ovary, we compared the total testosterone, free testosterone and SHBG levels in three patterns of polycystic ovary diagnosed with transvaginal ultrasonography (18 in group 1, fewer than 5 cysts identified; 16 in group 2, 5-10 cysts; and 27 in group 3, 10 or more). Free testosterone, but not total testosterone, significantly correlated with body mass index. Androgen levels were found to increase and SHBG levels to decrease with increases in the amount of ovarian cysts, and the evaluation of free testosterone was important in diagnosing the polycystic ovary syndrome.

[The life spans, cause of death and pathological findings of Fukuyama type congenital muscular dystrophy--analysis of 24 autopsy cases]

The case cards for autopsied patients with Fukuyama type congenital muscular dystrophy (FCMD) which included clinical data and pathological findings were filled in 10 national hospitals and 2 other institutes in Japan. The cards of 24 patients who died between 1978 and 1991 were collected and analysed for this study. The ages at death ranged from 2 to 27 years with a mean of 14.29 +/- 6.18 years and represented a nearly unimodal distribution. The age at death in the 12 patients who died before 1983 ranged from 2 to 21 years and averaged 11.58 +/- 5.11 years, whereas the 12 patients who died after 1984 ranged from 3 to 27 years of age and averaged 17.00 +/- 6.44 years. The latter group lived significantly longer than the former (p < 0.05). Pulmonary infection was a more frequent cause of demise in the group of patients who died before 1983 than in those who died after 1984 (83.3% vs 25.0%). On the other hand, cardiac failure was a more common cause of death in the latter group (8.3% vs 50.0%). These data on the life spans and cause of death of FCMD were similar to those studied of Duchenne muscular dystrophy by Mukoyama et al (1984, 1986, 1987).(ABSTRACT TRUNCATED AT 250 WORDS)

Binding of membrane-anchored macrophage colony-stimulating factor (M-CSF) to its receptor mediates specific adhesion between stromal cells and M-CSF receptor-bearing hematopoietic cells

To explore the biologic significance of the membrane-anchored form of macrophage colony-stimulating factor (M-CSF), we examined whether interaction between membrane-bound M-CSF and its receptor mediates intercellular adhesion as well as cell proliferation and differentiation. Human M-CSF receptors were expressed on a murine interleukin-2 (IL-3)-dependent cell line, FDC-P2, by DNA transfection with the c-fms gene (FDC-P2-MCSFR). A human bone marrow-derived stromal cell line, KM102, was used in the cell adhesion assay. The expression of membrane-bound M-CSF on KM102 cells was demonstrated by flow cytometry and immunoblot analysis. After the incubation of parent and transformed FDC-P2 cells on confluent KM102 cells, nonadherent cells were removed and the cells attached to KM102 cells were examined microscopically. Almost all parent FDC-P2 cells were nonadherent, whereas a significant number of FDC-P2-MCSFR cells bound to KM102 cells. The addition of anti-M-CSF or anti-M-CSF receptor neutralizing antibodies dose-dependently inhibited the binding of [3H]-thymidine-labeled FDC-P2-MCSFR cells to KM102 cells. An excess amount of M-CSF also inhibited the binding. On the other hand, the addition of antibodies against some representative adhesion molecules (vitronectin receptor, Pgp-1/CD44, and VLA-4) did not inhibit the adhesion between FDC-P2-MCSFR cells and KM102 cells. These results support the idea that membrane-anchored M-CSF and its receptor may function as mediators of cell-cell adhesion.

Electrochemical Prevention of Marine Biofouling with a Carbon-Chloroprene Sheet

A carbon-chloroprene sheet (CCS) electrode was used for the electrochemical disinfection of the marine gram-negative bacterium Vibrio alginolyticus . When the electrode was incubated in seawater containing 10 5 cells per ml for 90 min, the amount of adsorbed cells was 4.5 × 10 3 cells per cm 2 . When a potential of 1.2 V versus a saturated calomel electrode was applied to the CCS for 20 min, 67% of adsorbed cells were killed. This disinfection was due to the direct electrochemical oxidation of cells and not to a change in pH or to the generation of toxic substances, such as chlorine. In a 1-year field experiment, marine biofouling of a CCS-coated cooling pipe caused by attachment of bacteria and invertebrates was considerably reduced by application of a potential of 1.2 V versus a saturated calomel electrode. Since this method requires low potential electrical energy, use of a CCS coating appears to be a suitable method for the clean prevention of marine biofouling.

Direct effects of cutaneous neuropeptides on adenylyl cyclase activity and proliferation in a keratinocyte cell line: stimulation of cyclic AMP formation by CGRP and VIP/PHM, and inhibition by NPY through G protein-coupled receptors

Many neuropeptides are present in the peripheral nerves of human skin and are distributed from the intraepidermis to subcutaneous appendages, and those peptides are considered to be involved in the pathogenesis of various inflammatory dermatoses. In this investigation, we determined the effects of various neuropeptides on intracellular cyclic adenosine-5'-monophosphate (AMP) formation in cultured human keratinocytes. Among the many peptides tested, calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP), peptide histidine-methionine (PHM), and growth hormone releasing factor (GRF) stimulated a rapid and marked formation of intracellular cyclic AMP in keratinocytes in a dose-dependent manner. The direct association of the receptors for CGRP and VIP with adenylyl cyclase in keratinocytes was confirmed by the findings that CGRP and VIP stimulated the enzyme activity in membrane preparations derived from cultured keratinocytes in the presence of guanosine triphosphate (GTP). On the other hand, neuropeptide Y (NPY) showed an inhibitory effect on forskolin-induced cyclic AMP accumulation in keratinocytes. This inhibitory effect of NPY was completely eliminated by glucocorticoid pretreatment of cultured keratinocytes. Furthermore, the presence of peptides that substantially increase intracellular cyclic AMP accumulation also stimulated DNA synthesis and proliferation in a human keratinocyte cell line in a dose-dependent manner. These results suggest that neuropeptides work directly as biologic modulators of keratinocytes through the cyclic AMP cascade.

Periodic mother deprivation during the light period reversed the phase of serotonin N-acetyltransferase activity rhythm of the pineal gland in rat pups

It has been reported that nursing mother rats can postnatally entrain the circadian rhythms of blinded rat pups, such as locomotor, drinking, and corticosterone rhythms. To gain more insight in the mechanism of the postnatal entrainment of such pups' circadian rhythms, we examined the serotonin N-acetyltransferase (NAT) activity rhythm in blinded rat pups subjected to periodic mother deprivation (PMD) in which mothers were periodically deprived of their pups during either half of a day. We found that only PMD during the light period shifted the phase of NAT activity rhythm in the pups. To cause a reversal of the NAT activity rhythm, it was necessary to repeat PMD for more than 6 days. PMD for 6 h each day also shifted the phase of the blinded rat pups, but it did not reverse the NAT rhythm, even when it was repeated for 10 days. In 9-h deprivation for 10 days, however, deprivation during the first 9 h of the light period reversed the phase, although the latter 9 h failed to cause reversal of the phase. On the other hand, restricted feeding of the mother took more than 11 days to reverse the phase and a foster mother in the cross-fostering experiment failed to affect the phase of pup's rhythm, when the rhythm was determined on the 11th postnatal day. These facts indicate that PMD during the light period is a potent entrainer of the pups' circadian NAT rhythms and provide a useful method of exploring the underlying mechanism of the entrainment of the pups' rhythm by the mother.

Experimental germanium dioxide-induced neuropathy in rats

We report an experimental model of germanium dioxide (GeO2)-induced neuropathy in rats. More than 6 months administration of GeO2 to young rats produced neuropathy characterized by segmental demyelination/remyelination and nerve edema. Electron microscopic studies demonstrated that changes in Schwann cells, such as an increased cytoplasmic volume or disintegration of the cytoplasm, were the earliest pathological findings. Schwann cell mitochondria contained high electron-dense materials. Subsequent removal of necrotic Schwann cell debris and myelin by invading macrophages was evident. These findings suggested that the Schwann cells themselves are the primary target of the toxin. The deposition of electron-dense granules in the intra-axonal vesicles, which was suggestive of glycogen granules in mitochondria, was observed in the advanced stage of the neuropathy. The findings of endoneurial edema with splitting of myelin lamellae were noted at the early stage of demyelination. Nerve edema may be the result of GeO2-induced endothelial cell injury.

The ascidian embryo as a prototype of vertebrate neurogenesis

Ascidian tadpole larvae, composed of only about 2500 cells, have a primitive nervous system which is derived from the neural plate. The stereotyped cell cleavage pattern and well characterized cell lineage in these animals allow the isolation and culture of identified blastomeres in variable combinations. Ascidian embryos express cell-type-specific markers corresponding to their cell fates, even when cultured under cleavage-arrest by cytochalasin B. This system provides us with a unique opportunity to study the roles of cell lineage and cell contact in early neuronal differentiation in the absence of events associated with complex morphogenesis. In addition, the isolated, cleavage-arrested blastomeres are ideally suited to electrical recording, permitting the use of ionic channels as specific markers for differentiation. In the cleavage-arrested embryos, suppression of one type of K+ channel, and induction of two types of Na+ channels, occur following cell contact with the vegetal blastomere. The combination of molecular and electrophysiological analyses on this simple animal system may provide insights into the nature of the cell interactions important in early neurogenesis, both in ascidians and in vertebrates.

Frequent occurrence of in vivo clonal expansion of CD4- CD8- T cells bearing T cell receptor alpha beta chains in adult humans

We have previously reported 2 cases of healthy men showing in vivo monoclonal expansion of mature CD4- CD8- alpha beta T cells. In the present study, an additional 3 adults were found to exhibit such an expansion, among a total 464 adult donors studied. These 5 individuals were otherwise physiologically normal, with no history of severe illness and autoimmune disease at the time of examination. To investigate the mechanisms of the clonal expansion, further characterization of the clonal cells was attempted. No apparent preference for usage of the T cell receptor beta chain variable region was observed in the clonal T cells. These clonal T cells showed lectin-dependent or redirected antibody-dependent cell-mediated cytotoxicities, whereas they could not lyse autologous lymphoblastoid cell lines. Failure of Fas antigen expression was not observed for any of these clones. These results suggest that clonal expansion of CD4- CD8- alpha beta T cells frequently occurs in the periphery without any T cell abnormalities.

Platelet substance P and 5-hydroxytryptamine in migraine and tension-type headache

Levels of substance P (SP) and 5-hydroxytryptamine (5-HT) in platelets were measured in 25 patients with migraine, 31 patients with tension-type headache (TH) and 27 healthy controls. The mean concentration of SP in platelets was 355.3 pg/10(9) platelets in patients with migraine, 290.8 pg/10(9) platelets in patients with TH and 180.8 pg/10(9) platelets in the controls. The concentrations of platelet SP in the migrainous patients and in the TH patients were significantly higher than those in the controls. The mean concentration of 5-HT in platelets was 619.7 ng/10(9) platelets in patients with migraine, 579.3 ng/10(9) platelets in patients with TH and 811.9 ng/10(9) platelets in the controls. The concentration of platelet 5-HT in the patients with TH was significantly lower than that in the controls. The platelet SP/5-HT ratio in the migrainous patients and in the TH patients were significantly higher than that in the controls. There was significant negative correlation between the concentrations of platelet SP and those of platelet 5-HT. These results may support the hypothesis that SP released from the terminals of the trigeminal nerves causes migraine either through direct actions on the vessels or by releasing 5-HT from the platelets. The high levels of platelet SP in TH patients might reflect release of SP from the pain sensory system.

Dominantly inherited motor and sensory neuropathy with excessive myelin folding complex

The two patients in a family having the clinical and electrodiagnostic features of hereditary motor and sensory neuropathy (HMSN) are described. The main histological features of sural nerve were segmental demyelination and remyelination with moderate to marked loss of myelinated fibers, and myelin folding complex along all of the large and small myelinated fibers. These features appeared morphologically similar to those observed in HMSN with excessive myelin outfolding, or globular neuropathy. Southern blot analysis suggests that there were neither duplication nor deletion of the peripheral myelin protein-22 gene in the patients. The presented two patients may be a rare form of dominantly inherited HMSN with myelin folding complex.

Fluoride release in vitro from various glass ionomer cements and resin composites after exposure to NaF solutions

The release of fluoride from 1) discs made from five glass ionomer cements and two composites, and 2) the same discs after exposure to different NaF solutions, were studied. The specimens were placed in distilled water for 10 wk. After 24 h and then once a week, the specimens were transferred to fresh distilled water. After 5 wk, the specimens were divided into four groups and exposed to 0, 0.02, 0.2 and 2% NaF solutions for 5 min. The fluoride release was highest during the first week after preparation, after which it decreased sharply and then more slowly. The amount of fluoride released was ordered: liner/base > restorative glass ionomer > composites. The composites released significantly less fluoride than the glass ionomer cements. After exposure to NaF, the fluoride release was significantly higher for the silver cermet material than for the other glass ionomers tested. From a clinical point of view, the results from this study imply that glass ionomer restorations may act as intraoral devices for the controlled slow release of fluoride at sites at risk for recurrent caries.

[Effect of folic acid for treatment of homocystinuria due to 5,10-methylenetetrahydrofolate reductase deficiency]

Deficiency of 5,10-methylenetetrahydrofolate reductase (MTHFR) leads to deficient remethylation of homocysteine and is one of the causes of homocystinuria. Only 28 patients have been reported so far. A 15-year-old boy with mild mental retardation was admitted in our hospital because of progressive difficulty in walking. He is the second child. The paternal grandparents are first cousins. On admission, clinical examination revealed mild disturbance of consciousness, left hemiparesis, truncal ataxia, pyramidal tract signs in the lower limbs and sensory disturbance in his feet. There was no marfanoid symptoms nor ectopia lentis. EEGs showed slow activity with sporadic spike and wave complexes. Peak latencies of N20 of median nerves SEPs, the third and 5th wave of ABR and P100 of VEP were delayed. The CT scan showed mild cortical atrophy and MRI revealed increased intensity on T2-weighted images in the cerebral white matter. Biochemical studies revealed homocystinuria with homocystinemia. Both plasma methionine and serum folic acid were low. Serum vitamin B12 and methylmalonic acid in urine were normal. The lymphoblastoid cell line, transformed by Epstein-Barr virus of lymphocytes of the patient, could not grow when homocysteine was substituted in the culture medium for methionine. The normal control cell line grew naturally under the same condition. A diagnosis of homocystinuria due to MTHFR deficiency was made. The patient was on various therapeutic regimens for about 70 days. Treatment with high doses of folic acid (400 mg/day) resulted in disappearance of homocysteine in plasma, remarkable decrease of homocysteine in urine and increase of methionine in plasma of the patient.(ABSTRACT TRUNCATED AT 250 WORDS)

A polymerase chain reaction system for rapid diagnosis of scrub typhus within six hours

A rapid diagnostic system for scrub typhus (tsutsugamushi disease) was established using the polymerase chain reaction (PCR) combined with microplate hybridization. With this system, diagnosis can be made within six hours without the need for radioisotopes, electrophoresis, or membrane hybridization. The use of a PCR processor and DNA-precoated enzyme-linked immunosorbent assay plates allows a rapid and precise diagnosis to be easily made even in primary medical care clinics.

Altered fibronectin-dependent cell adhesion by PDGF accompanies phenotypic modulation of vascular smooth muscle cells

PDGF promotes growth of smooth muscle cells (SMCs) and induces morphological changes. We investigated the effects of PDGF on cell-matrix adhesion of SMCs. PDGF reorganized integrin distribution as well as actin filament structure. PDGF-treated cells attached more loosely to fibronectin than non-treated cells. Decreased expression of alpha-actin by PDGF was antagonized by coating culture dishes with fibronectin but not with vitronectin and laminin. The inhibition of cell adhesion by GRGDSP oligopeptide and anti-fibronectin receptor antibody led to the reduction in alpha-actin expression. These results suggest that PDGF may modulate phenotype of SMCs by altering fibronectin-integrin interaction.

Capsaicin applied to rat lumbar intervertebral disc causes extravasation in the groin skin: a possible mechanism of referred pain of the intervertebral disc

Administration of 10 micrograms of capsaicin into the anterior portion of a lumbar intervertebral disc of rats pretreated with Evans blue (i.v.) caused dye extravasation in the groin skin. This phenomenon occurred even when the spinal nerve of the same segment, bilateral sympathetic trunks, and/or the anterior L2 spinal root had been cut; it did not occur in rats with a cut genitofemoral nerve. Infiltration of capsaicin solution directly into the genitofemoral nerve did not cause dye extravasation. These results suggested the presence of dichotomizing sensory C-fibers which innervate both the intervertebral discs and the groin skin in the L2 spinal nerve. If such dichotomizing fibers exist in man, they may contribute to the groin pain sometimes associated with intervertebral disc lesions.