Production of neosolaniol monoacetate by an undescribedFusarium species resemblingF camptoceras

Cultures of 12 South African isolates of an undescribedFusarium species resembling but distinct fromF camptoceras were analysed for the presence of diacetoxyscirpenol (DAS), neosolaniol monoacetate (NMA), and T-2 toxin, by capillary gas chromatography utilizing electron capture detection. No DAS or T-2 toxin could be detected in any of the cultures of the isolates. NMA was, however, detected in 10 of the 12 isolates at levels ranging from 310 to 2060 ng/g. The method used, was primarily developed for the determination of DAS and T-2 toxin in fungal cultures and grain samples but was found to be suitable for the coextraction of NMA at an average recovery of 80.8%, with a detection limit in the order of 100 ng/g. Supportive evidence for the presence of the NMA was obtained by capillary gas chromatography / mass spectrometry. Regarded as a relatively rare trichothecene, NMA has never been reported to occur naturally and has previously been shown to be produced by only a fewFusarium strains.     

Patterns of bleeding in adolescents with severe haemophilia A.

Eighty-two boys with severe haemophilia A who spent some time at Lord Mayor Treloar College during 1973-7 were studied. All episodes of bleeding that occurred during term time were recorded, along with the number of transfusions. The bleeding frequency among these boys, most of them aged 10-17 years, increased steadily from 8,31 episodes/100 days in 1973 to 12,63 episodes/100 days in 1977. At the same time there was a steady fall in bleeding frequency with age. Altogether 24% of bleeding episodes were into the elbow joint, 22% into the knee, and 15% into the ankle. As the boys grew older the proportion of bleeding episodes in the legs declined and that in the arms increased. The overall results reflect the fact that special schools now see only the severest cases of haemophilia. The pattern of bleeding during adolescence suggests that concepts of management of arm bleeding need modifying.     

Differential effects of non-genotoxic carcinogens and proliferating agents on cell growth, survival and apoptosis in hepatic cells in vitro.

Many nongenotoxic carcinogen's (ngc) produce hyperplastic lesions from which neoplastic foci may arise. Modulation of the rate of apoptosis by some ngc's within these lesions may be critical to their mechanism of tumour promotion but some may be cytotoxic. To establish if these compounds are apoptotic or necrotic in vitro, three ngc's (12-0-tetradecanoyl phorbol-13-acetate (TPA); nickel, and di(2-ethylhexyl-phthalate (DEHP), two noncarcinogenic hepatoproliferating agents (1,4-dichlorobenzene (DCB; HGF) and an in vitro genotoxic reference compound (7-hydroxy-2-acetylaminofluorene (70H2AAF) were used to induce mitogenic or growth responses in two liver cell-lines HepG2 and JTC-15. MTT and 3H-thymidine incorporation assays were used to measure cell growth and DNA replicative activity respectively. Rates of apoptosis were assayed using FITC-annexin V with propidium iodide staining and flow cytometry. Responses in HepG2 cells were HGF (proliferation at > or = 3 ng/ml), TPA (cell growth at > or = 8 ng/ml), DEHP (proliferation at > or = 0.05 microg/ml). NiCl2 and 70H-2AAF were cytotoxic above 0.001 microg/ml and 100 ng/ml respectively. An equivocal result was obtained for DCB. Responses in JTC-15 cells were HGF (proliferation, 3 ng/ml), TPA (DNA replication, 10 ng/ml), and DEHP (cell mass, 2.5 microl/ml). NiCl2 and 70H-2AAF were cytotoxic above 0.01 microg/ml and 110 mg/ml respectively. Equivocal results were obtained for DCB. In flow cytometry assays apoptotic and necrotic populations were not clearly separable. Approximate rates of apoptosis in HepG2 were: control 8.7%; DEHP, 10.19%. NiCl2, 12.67%; 70H2AAF, 16.56%; TPA, 19.72%; HGF, 23.73%; DCB, 24.59%; positive apoptotic control (taxol) 26.94%. These data show apoptosis was increased in chemically activated populations of HepG2. The ngc, DEHP, unexpectedtly produced proliferation in HepG2 and almost totally suppressed apoptosis in vitro in HepG2 relative to the non-carcinogenic hepatoproliferators. The rate of apoptosis induced by the ngc TPA was not considered to be sufficiently different to the rates of apoptosis induced by the noncarcinogenic hepatoproliferators. The results emphasize the importance of considering necrotic reactions from effects on apoptosis in detecting non-genotoxic carcinogens.     

Synthesis and anti-inflammatory properties of some aromatic and heterocyclic aromatic curcuminoids

A variety of novel aromatic and heterocyclic aromatic curcuminoids were synthesised, characterised and their anti-inflammatory activities (AIA) determined in vivo. Some of these compounds also were tested for inflammatory mediator production. The AIA of the main representatives of these compounds were assessed by oral administration to female Wistar rats using (a) acute carrageenan-induced paw oedema, (b) chronic adjuvant arthritis (therapeutic mode), and (c) anti-pyretic activity assessed in the yeast pyrexia. Gastric ulceration was determined in pre-inflamed rats. Natural curcumin showed modest aspirin-like anti-inflammatory activity which was enhanced when co-administered with the PGE(1) analogue misoprostol as a synergist. In contrast, four novel curcuminoids (RK-97, RK-103, RK-104 and RK-106) in which the bis-methoxy-phenyl group of curcumin was replaced with bis-dimethoxybutenolidyl-(ascorbate), bis-naphthyl, and bis-furanyl derivatives, respectively, had potent activity in the anti-arthritic assay with little gastric or systemic toxicity, compared with the vehicle-treated controls. Of the curcuminoids the furan RK-106 was the only compound to inhibit production of TNFα and IL-1β in a monocytic cell-line THP-1 in vitro. The inactivity of RK-106 on the production of PGE(2) may be related to its absence of gastrotoxicity. None of the curcuminoids exhibited anti-pyretic activity and this may also be related to its insensitivity to PGE(2). Thus, these novel curcuminoids, such as RK-106, may warrant the development of new low gastro-toxic anti-inflammatory agents with selective inhibitory activity of cytokine inflammatory mediators.     

Induction of long-term B-cell depletion in refractory rheumatoid arthritis patients preferentially affects autoreactive more than protective humoral immunity

Introduction

B-cell depletion has become a common treatment strategy in anti-TNF-refractory rheumatoid arthritis (RA). Although the exact mechanism of how B-cell depletion leads to clinical amelioration in RA remains to be elucidated, repetitive treatment with B-cell-depleting agents leading to long-term B-cell depletion has been reported to be beneficial. The latter has led to the hypothesis that the beneficial effects of B-cell depletion might act through their influence on pathogenic autoreactive plasma cells.

Methods

In this study, we investigated the effects of a fixed retreatment regimen with anti-CD20 mAbs on the humoral (auto)immune system in a cohort of therapy-refractory RA patients.

Results

Fixed retreatment led to long-term B-cell depletion in peripheral blood, bone marrow and, to a lesser extent, synovium. Also, pathologic autoantibody secretion (that is, anticitrullinated peptide antibodies (ACPAs)) was more profoundly affected by long-term depletion than by physiological protective antibody secretion (that is, against measles, mumps and rubella). This was further illustrated by a significantly shorter estimated life span of ACPA-IgG secretion compared to total IgG secretion as well as protective antibody secretion.

Conclusion

By studying plasma cell function during an extensive 2-year period of B-cell depletion, autoantibody secretion was significantly shorter-lived than physiologically protective antibody secretion. This suggests that the longevity of autoreactive plasma cells is different from protective long-lived plasma cells and might indicate a therapeutic window for therapies that target plasma cells.     

Neurotransmitter alterations in embryonic succinate semialdehyde dehydrogenase (SSADH) deficiency suggest a heightened excitatory state during development

Background  

SSADH (aldehyde dehydrogenase 5a1 (Aldh5a1); γ-hydroxybutyric (GHB) aciduria) deficiency is a defect of GABA degradation in which the neuromodulators GABA and GHB accumulate. The human phenotype is that of nonprogressive encephalopathy with prominent bilateral discoloration of the globi pallidi and variable seizures, the latter displayed prominently in Aldh5a1^-/- mice with lethal convulsions. Metabolic studies in murine neural tissue have revealed elevated GABA [and its derivatives succinate semialdehyde (SSA), homocarnosine (HC), 4,5-dihydroxyhexanoic acid (DHHA) and guanidinobutyrate (GB)] and GHB [and its analogue D-2-hydroxyglutarate (D-2-HG)] at birth. Because of early onset seizures and the neurostructural anomalies observed in patients, we examined metabolite features during Aldh5a1^-/- embryo development.