Transport of bestatin in rat renal brush-border membrane vesicles.

Bestatin [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl-L-leucine] is a dipeptide, comprising L-leucine and an unusual beta-amino acid. We studied its transport mechanism in rat renal brush-border membrane vesicles. Uptake of cephradine, an aminocephalosporin, by isolated brush-border membrane vesicles was trans-stimulated and cis-inhibited by bestatin, indicating that these drugs are transported via the same transport system(s).

Characteristics of organic cation transporter in rat renal basolateral membrane.

Characteristics of organic cation transport system were studied in rat renal basolateral membrane and compared with those in brush-border membrane. We first examined the effect of various chemical modifiers on tetraethylammonium uptake by the membrane vesicles. Treatment with N,N'-dicyclohexylcarbodiimide and phenylglyoxal (carboxyl groups and arginine residues specific reagent, respectively) resulted in inhibition of tetraethylammonium transport in both basolateral and brush-border membranes.

Desensitization of delayed-type hypersensitivity in mice: suppressive environment.

The systemic injection of high doses of antigen into a preimmunized animal results in transient unresponsiveness of cell-mediated immune responses. This phenomenon is known as desensitization. Serum interleukin 2 (IL-2) activity was found transiently in desensitized mice at 3 h after the antigen challenge.

Suppression of pulmonary granulomatous inflammation by immunomodulating agents.

We demonstrated previously that macrophages and macrophage-derived cytokines including lymphocyte-activating factors (LAFs) play a critical role in lung granuloma formation in mice and that granulomas sizes correlated with LAF activity in the lesions. In the present study, we examined the effects of D-penicillamine (D-Pc), 2-acetylthiomethyl-3-(4-methyl-benzoyl)propionic acid (KE-298) and dexamethasone (Dex) on dextran bead-induced lung granulomas in mice. KE-298 is a newly synthesized compound containing sulfur (S) similar to D-Pc.

Synchronous cancer of squamous cell carcinoma of the lung and lymphocytic leukemia (B-cell type): a case report.

The patient was an 82-year-old male who consulted us over a lymph node enlargement in the right side of his neck. The WBC was 23,700/microliters (lymphocytes 80%), and a diagnosis of chronic lymphocytic leukemia (CLL) was given based on the findings of a bone marrow puncture and lymph node biopsy. During the observation period, abnormal shadows accompanied by cavitation appeared in the right lower lung field, and CT-guided percutaneous biopsy findings indicated a squamous cell carcinoma of the lung.

Expression of renal organic cation transporter in Xenopus laevis oocytes.

The expression of the organic cation transport system of rat renal proximal tubules has been studied in Xenopus laevis oocytes injected with poly(A)+ RNA from the rat renal cortex. The effectiveness of the technique was confirmed by examining expression of the Na+/D-glucose co-transporter. Compared with water-injected and non-injected oocytes, the injection of total poly(A)+ RNA resulted in about a 3-fold increase in tetraethylammonium (TEA) uptake activity.

H+ coupled active transport of bestatin via the dipeptide transport system in rabbit intestinal brush-border membranes.

Bestatin [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl-L-leucine], a dipeptide containing an unusual amino acid, has been used clinically as an anticancer agent in p.o. dosage form.

Inflammatory cytokines and enzymes in synovial fluid of patients with rheumatoid arthritis and other arthritides.

Cytokines and lysosomal enzymes, which are produced by inflammatory cells, play a role in inflammation. We have found that synovial fluid (SF) in rheumatoid and septic arthritis contained a large number of white blood cells (WBCs) and high levels of cytokines and enzymes, while in contrast the SF of osteoarthritis and traumatic arthritis did not contain significant amounts. Measurements of WBCs, cytokines and enzymes in SF are useful for evaluating clinical disease activity.

Trans-stimulation effect on H(+)-organic cation antiport system in rat renal brush-border membranes.

Trans-stimulation effect on tetraethylammonium (an organic cation) transport was examined in rat renal brush-border membrane vesicles. The uptake of [14C]tetraethylammonium at pH 6.0-8.

[Detection of cross-reacting protein antigen from urinary tract pathogens by using reversed passive gelatin agglutination test].

The basic studies on detection and titration of the 60-kDa cross-reacting protein antigen (CRPA), which is common to gram-negative rods, by reversed passive gelatin agglutination test with monoclonal and polyclonal antibodies were performed. The gelatin particles sensitized with 500 micrograms/ml of the monoclonal antibody had an ability to react with 200 ng/ml of the purified CRPA for 1.5 h.

Transport mechanisms of bestatin in rabbit intestinal brush-border membranes: role of H+/dipeptide cotransport system.

Bestatin [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl-L-leucine], a potent inhibitor of aminopeptidase B and leucine aminopeptidase, enhances the immune response to activate the defense mechanism of the living organism and suppresses the growth and metastasis of cancer. Bestatin has been effectively used by p.o.

Adenosine 5'-O-(3-thiotriphosphate) hydrolysis by dynein.

The interaction of dynein with ATP gamma S, a phosphorothioate analogue of ATP, has been investigated in depth. The hydrolyses of ATP gamma S and of ATP were shown to be mutually competitive. ATP gamma S induced complete dissociation of the microtubule-dynein complex such that the time course of dissociation monitored by stopped-flow light-scattering methods followed a single exponential.

Inhibitory effect of diethyl pyrocarbonate on the H+/organic cation antiport system in rat renal brush-border membranes.

We examined the effect of diethyl pyrocarbonate (DEPC), a histidine-specific reagent, on the H+/organic cation antiport system in brush-border membrane vesicles isolated from the rat renal cortex. Pretreatment of membrane vesicles with DEPC resulted in the inhibition of tetraethylammonium transport. This inhibition was reversed by subsequent treatment with hydroxylamine, but not with dithiotreitol.

Steady-state kinetic study on the inhibition of the adenosinetriphosphatase activity of dynein from Tetrahymena cilia by glycerol.

The characteristics of glycerol-induced inhibition of the dynein ATPase extracted from Tetrahymena cilia were investigated. Fifty percent inhibition was observed at about 15% (v/v) glycerol with the 22S dynein Mg-ATPase. Ethylene glycol was equally inhibitory, while sucrose, a kind of polyol, was less effective.

Immune responses in Mycoplasma pneumoniae infection of infant mouse and of man.

Infant mice (2 to 4 days old) were exposed to living Mycoplasma pneumoniae. The organisms were isolated in the order of 10(3) to 10(4) colony-forming units from the lungs of mice for 2 weeks after infection. Mononuclear cell infiltration was present in the lungs of infected mice.

Unusual inclusions in mature polymorphonuclear neutrophils of cyclic neutropenia.

The bone marrow of an 11-year-old girl with cyclic neutropenia was examined by electron microscopy. In the nonneutropenic phase, mature polymorphonuclear neutrophils had numerous bundles of filamentous inclusions in both cytoplasms and nucleus. Primary granules were slightly increased in number.

Abnormal sensations of the pharyngo-larynx.

By use of a chart questionnaire, abnormal sensations of the pharyngo-larynx (ASPL) were analyzed between May 1-October 30, 1984 and followed up uintil 1 year after the first consultation date. Two hundred ninety-one patients from the total were found to suffer from ASPL, the ratio of ASPL to all out-patients being 1.47%.

Synthesis of cyclic silyl nucleosides having bulky groups on the silicon atom.

Synthesis of cyclic silyl nucleosides having bulky tert-butyl groups on the silicon atom has been investigated. Cyclic silyl deoxyribonucleosides having one tert-butyl group on the silicon atom was obtained without difficulty in the standard silylation reaction using dichlorosilane and imidazole. However, under similar conditions the reaction with di-tert-butyldichloro-silane proceeded only slowly by virtue of steric hindrance.