The in vitro pharmacological profile of KR31080, a nonpeptide AT1 receptor antagonist

Summary— KR31080 (2-butyl-5-methyl-6-(1-oxopyridin-2-yl)-3-[[2'-(1H-tetrazol-5-yl) biphenyl-4-yl]methyl]-3H-imidazo[4,5-b] pyridine) is a potent inhibitor of angiotensin type 1 (AT₁) receptors in rabbit aorta and human recombinant AT₁ receptors. In the isolated rabbit thoracic aorta, KR31080 caused a nonparallel shift to the right of the concentration-response curves to angiotensin II (All) with decreased maximal response (pD'₂ = 10.1 ± 0.1), but had no effect on the contractile response induced by norepinephrine. KR31080 inhibited specific [¹²⁵I]AII binding to rabbit aortic membranes (AT, receptors) and [¹²⁵I][Sar¹, Ile⁸]AII binding to human recombinant AT₁ receptors in a concentration-dependent manner with IC₅₀ values of 0.84 ± 0.08 nM and 1.92 ± 0.15 nM, respectively, but did not inhibit specific [¹²⁵I)AII binding to bovine cerebellum membranes (ÀT₂ receptors). In the Scatchard analysis, KR31080 interacted with rabbit aortic AT₁ receptors in a competitive manner, similar to losartan. These results demonstrate that KR31080 is a potent and AT₁ selective angiotensin receptor antagonist which exerts a competitive antagonism in the [¹²⁵I]AII binding assay and insurmountable AT₁ receptor antagonism in the functional study.     

Clusterin expression in cutaneous CD30-positive lymphoproliferative disorders and their histologic simulants

Background:  Clusterin is a ubiquitous 80 kDa heterodimeric glycoprotein previously shown to be expressed on tumor cells of systemic and, to a lesser extent, primary cutaneous anaplastic large cell lymphoma (PC-ALCL). Lymphomatoid papulosis (LyP), an important differential diagnosis of ALCL, has been studied for clusterin expression in only a small number of cases. The aim of this study was to compare clusterin immunostaining patterns in LyP and other cutaneous histologic simulants with those of PC-ALCL.
Methods:  Formalin-fixed, paraffin-embedded sections of PC-ALCL (6), LyP (20), mycosis fungoides with large cell transformation (MF-LCT, 12), pityriasis lichenoides et varioliformis acuta (PLEVA, 12), arthropod bite reaction (ABR, 12) and lymphomatoid reactions (LR, 9) were immunostained for clusterin and evaluated for staining pattern and distribution. All diagnoses were made with clinicopathologic correlation.
Results:  Characteristic dot-like Golgi staining was identified in 10/20 LyP (50%), 4/6 PC-ALCL (67%) and 9/12 MF-LCT (75%). Two of 12 PLEVA (17%), 1 of 12 ABR (8%) and 2 of 8 LR (25%) had lymphocytes (< 25%) with diffuse cytoplasmic staining. Dermal dendritic cells stained strongly for clusterin. High background staining occurred in some cases.
Conclusion:  Clusterin immunostaining does not reliably distinguish between LyP, PC-ALCL or MF-LCT, but could distinguish LyP from its reactive histologic simulants.     

The course of schizophrenia: Some remarks on a yet unsolved problem of retrospective data collection

Summary The retrospective assessment of symptoms and syndromes is a basic measure in research of the longitudinal course of schizophrenia. In spite of its importance there have been few studies evaluating the standard of quality of instruments for retrospective data collection. Combining retrospectively and cross-sectionally collected data on schizophrenic symptomatology in a cohort study over a period of 5 years revealed a significant underestimation of symptoms when assessed in retrospect. The need for studies on the validity of instruments for the retrospective assessment of symptoms is stressed.     

Pneumatosis cystoides intestinii

Zusammenfassung Die Pneumatosis cystoides intestinii (PCI), das Auftreten submuköser oder subseröser, gasgefüllter Zysten in der Wand des Gastrointestinaltrakts, tritt als seltene Erkrankung ohne eindeutige Geschlechtspräferenz vorwiegend in der 3. bis 5. Lebensdekade auf. Atiopathogenetisch werden unterschiedliche Faktoren diskutiert, am wahrscheinlichsten ist eine bakterielle Ursache (Clostridium perfringens) in Verbindung mit einer minimalen Unterbrechung der Mukosaintegrität. Eine pathognomonische Symptomatik gibt es nicht, das klinische Bild reicht von asymptomatischen Zufallsbefunden bis zur Hämatochezie. Die Diagnose wird durch den Nachweis der Gaseinschlüsse mittels Abdomenübersichtsaufnahme und Kolonkontrasteinlauf gestellt. Als Behandlungsmethoden für symptomatische Patienten stehen Sauerstofftherapie, Antibiotikagabe (Metronidazol) und in schweren Fällen die Resektion des betroffenen Darmabschnitts zur Verfügung.

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Pneumatosis cystoides intestinalis (PCI), a condition involving submucosal or subserosal gas-containing cysts of the wall of the gastrointestinal tract, is a rare entity. It is mostly diagnosed between the third and fifth decades of life without a clear sexual predominance. Different aetiopathogenetic factors are under discussion, the most probable being a bacteriologic cause (Clostridium perfringens) in combination with minimal leaks in mucosal barrier. There are no pathognomonic symptoms; the clinical picture ranges from incidental findings to haematochezia. Diagnosis is based on plain abdominal film and X-ray following barium enema. Methods of treatment in symptomatic cases are oxygen and antibiotic (metronidazole) therapies and, in severe cases, resection of the diseased part of the intestine.

     

Carotenoids up-regulate connexin43 gene expression independent of their provitamin A or antioxidant properties.

Epidemiological evidence and studies in whole animals and cell culture have indicated that carotenoids have cancer chemopreventive action. In mouse C3H10T1/2 cells, this activity is highly correlated with the ability of carotenoids to up-regulate gap junctional intercellular communication. Here, we report that in mouse cells, carotenoids increase the expression of connexin43, a gene that encodes a major gap junction protein. This effect appears unrelated to their provitamin A or antioxidant properties, since carotenoids with and without provitamin A activity increased levels of connexin43 mRNA and protein, whereas the antioxidants methyl-bixin and alpha-tocopherol were inactive. Moreover, the active carotenoid canthaxanthin did not induce the vitamin A-inducible gene retinoic acid receptor-beta. Connexin43 is the first carotenoid-inducible gene described in mammals. By indicating an additional pathway through which carotenoids function, these data provide a mechanistic basis for cancer chemoprevention by carotenoids and may lead to a re-evaluation of carotenoid physiology.     

Use of protein A immunoadsorption as a treatment for thrombocytopenia in HIV-infected homosexual men: a retrospective evaluation of 37 cases.

Thirty-seven HIV-infected homosexual men with thrombocytopenia (less than 100 x 10(9)/l) received protein A immunoadsorption treatments to remove platelet-sensitizing immunoglobulin (Ig) G and circulating immune complexes (CIC) from plasma. Patients received an average of six treatments each, consisting of 250 ml plasma over a 3-week period. Clinical improvement in hemorrhagic symptoms associated with substantial increase in platelet counts was achieved in 18 patients. These responses were maintained over a median follow-up period of more than 7 months in 14 evaluable patients who were not lost to follow-up (three patients relapsed in 2 weeks and one received another therapy). Generally, moderate transient treatment-related side-effects included fever, musculoskeletal pain, chills and nausea. A transient serum sickness-like reaction was observed in seven patients, leading to termination of treatment in two. Clinical responses were associated with significant decreases in levels of platelet-sensitizing Ig, including CIC. Stimulation of broadly cross-reactive anti-antigen-binding fragment [F(ab)2], antibodies contributed to these responses. Protein A immunoadsorption is an effective alternative treatment for HIV-associated thrombocytopenia.     

Radical effects on mutation spectra in lambda phage.

Mutations in the lambda repressor gene cI (710 bp) were induced by 60Co-gamma radiation in dissolved lambda phage DNA. After in vitro DNA packaging to lambda phage particles (pack phage) and phenotypic expression of the mutants, DNA was sequenced directly. Two-thirds of mutations were located in the amino terminus region of the gene without any signs of hotspots. Changes consisted of (+1) insertions (25%) and base substitutions (75%). Transitions were exclusively G/C to A/T. Transversions were mostly G/C to C/G and few G/C to T/A. We did not find A/T to T/A transversions, A/T to G/C transitions, deletions and gross rearrangements. In most of the base substitutions a pre-existing base pair had been replaced by an A/T pair; this might come from 'non-instructional sites' like abasic sites. Several mechanisms for base substitutions are considered.