Reactions of 'bay-region' and non-'bay-region' diol-epoxides of benz(a)anthracene with DNA: evidence indicating that the major products are hydrocarbon-N2-guanine adducts

The rates of reaction and the products formed when two vicinaldiol-epoxides derived from benz(a)an-thracene, anti-BA-3, 4-dioI1, 2-oxide (t-3, r-4-dihydroxy-t-1, 2-oxy-l, 2, 3, 4-tetrahydrobenz(a)anthracene)^* and anti-BA-8, 9-diol 10, 11-oxide (r-8, t-9-dihydroxy-t-10,ll-oxy-8, 9, 10, ll-tetrahydro-benz(a)anthracene) reacted withDNA were studied in vitro and the results were compared withthose obtained in similar experiments using anti-BP-7, 8-diol9, 10-oxide (r-7, t-8-dihydroxy-t-9, 10-oxy-7, 8, 9, 10-tetrahydrobenzo(a)pyrene).The reactivities appeared to decrease in the order anti-BP-7,8-diol 9, 10-oxide > anti-BA-3, 4-diol 1, 2-oxide anti-BA-8,9-diol 10, 11-oxide. The diol-epoxides reacted to a similarextent with single- and with double-stranded DNA but reactionswith dGMP, at equivalent concentrations, were much slower thanwith DNA. With the diol-epoxides of benz(a)anthracene, two principaladducts were present in DNA hydrolysates and evidence was obtained,based on pK determinations before and after nitrous acid treatment,consistent with their being N²-guanine derivatives, analogousto the known DNA-reaction products of benzo(a)-pyrene 7, 8-diol9, 10-oxide.     

Multiple myeloma in an adolescent

The radiographic findings of a 15-year-old Brazilian male with diagnosis of multiple myeloma are described. He presented with claudication and recent onset of tender painful swelling of the right mid leg. Radiographs showed wide spread soap bubble lesions of the skull, long bones, spine, pelvis, ribs, shoulders, and clavicles. The diagnosis was confirmed by the presence of a plasmacytoma on tissue biopsy (femur), serum IgG gammopathy and Bence-Jones proteinuria.Supported by grants (CA-20180 and CA-21765) from the National Cancer Institute and the American Lebanese Syrian Associated Charities (ALSAC)     

Magnetic resonance imaging in the evaluation of patients with aseptic meningoencephalitis and connective tissue disorders

OBJECTIVE: To describe the role of magnetic resonance imaging (MRI) in the evaluation of patients with chronic and recurrent aseptic meningitis. METHOD: A retrospective study of five patients with aseptic meningoencefalitis diagnosed by clinical and CSF findings. CT scans showed without no relevant findings. RESULTS: MRI showed small multifocal lesions hyperintense on T2 weighted images and FLAIR, with mild or no gadolinium enhancement, mainly in periventricular and subcortical regions. Meningoencephalitis preceded the diagnosis of the underlying disease in four patients (Beh?et's disease or systemic lupus erythematosus). After the introduction of adequate treatment for the rheumatic disease, they did not present further symptoms of aseptic meningoencephalitis. CONCLUSION: Aseptic meningoencephalitis can be an early presentation of an autoimmune disease. It is important to emphasize the role of MRI in the diagnosis and follow-up of these patients.     

Induction of partial protection in mice after oral administration of Lactococcus lactis producing Brucella abortus L7/L12 antigen.

The Brucella abortus ribosomal protein L7/L12 is an immunodominant antigen and an interesting candidate for the development of oral live vaccines against brucellosis. Here, a recombinant Lactococcus lactis strain producing L7/L12 under the control of nisin inducible promoter was orally administered to BALB/c mice. Significant levels of anti-L7/L12 specific IgA detected in feces revealed an induced local humoral immune response. However, serum analysis did not reveal any anti-L7/L12 antibodies suggesting the absence of a systemic response. Nevertheless, the vaccinated mice showed a partial protective immunity against B. abortus virulent strain (S2308) challenged by intraperitoneal inoculation.     

Profile of non-compliance in lymphoblastic leukaemia

A nationwide study of intracellular drug metabolite concentrations in children prescribed 6-mercaptopurine for the treatment of lymphoblastic leukaemia was carried out to assess interpatient variability at a standardised dose. Nine children (2% of the total) had completely undetectable metabolites, indicative of non-compliance. Five were adolescents, but otherwise they had no obvious distinguishing characteristics. Not taking any 6-mercaptopurine at all is uncommon, but the problem cannot be predicted. The total number of children who do not comply cannot be determined from this study, but the nine children described represent only a fraction of these.     

Immune responses against SARS-coronavirus nucleocapsid protein induced by DNA vaccine

The nucleocapsid （N） protein of SARS-coronavirus （SARS-CoV） is the key protein for the formation of the helical nucleocapsid during virion assembly. This protein is believed to be more conserved than other proteins of the virus, such as spike and membrane glycoprotein. In this study, the N protein of SARS-CoV was expressed in Escherichia coli DHSalpha and identified with pooled sera from patients in the convalescence phase of SARS. A plasmid pCI-N, encoding the full-length N gene of SARS-CoV, was constructed. Expression of the N protein was observed in COS1 cells following transfection with pCI-N. The immune responses induced by intramuscular immunization with pCI-N were evaluated in a murine model. Serum anti-N immunoglobutins and splenocytes proliferative responses against N protein were observed in immunized BALB/c mice. The major immunoglobulin G subclass recognizing N protein was immunoglobulin G2a, and stimulated splenocytes secreted high levels of gamma interferon and IL-2 in response to N protein. More importantly, the immunized mice produced strong delayed-type hypersensitivity （DTH） and CD^8＋ CTL responses to N protein.