Bryostatin 1-induced modulation of nucleoside transporters and 2-chlorodeoxyadenosine influx in WSU-CLL cells

WSU-CLL cells, a fludarabine resistant B-cell chronic lymphocytic leukemia cell line, has been shown to exhibit enhanced sensitivity to 2-chlorodeoxyadenosine (2-CdA) following 48-72 h exposure to bryostatin 1. For 2-CdA to manifest its chemotherapeutic activity, it must first enter the cell through one of several specific nucleoside transporter systems. We present data to show that bryostatin 1-induced enhanced influx of 2-CdA is in part the result of bryostatin 1-induced modulation of nucleoside transporters in WSU-CLL cells. The bi-directional equilibrative NBMPR sensitive transporters in WSU-CLL cells were significantly down-regulated 90 min post-exposure to 1-200 nM bryostatin 1. This down-regulation was evident up to 144 h. In contrast, WSU-CLL cells exhibited a transient increase in Na+-dependent concentrative 2-CdA influx from 48 to 96 h after bryostatin 1 exposure which was evident for a longer duration than that accounted for by the increase in deocycytidine kinase activity. These data may, in part, explain the enhanced efficacy of 2-CdA seen in WSU-CLL cells following 48-72 h exposure to bryostatin 1. It may raise questions as to the importance of the bi-directional transporters in determining the resistance or sensitivity of CLL cells to 2-CdA or other nucleoside analogues.     

DFNB39, a recessive form of sensorineural hearing impairment, maps to chromosome 7q11.22-q21.12

This article describes the identification of a novel locus (DFNB39) responsible for an autosomal recessive form of hearing loss segregating in a Pakistani consanguineous family. The hearing impaired members of this family present with profound prelingual sensorineural hearing impairment and use sign language for communications. Linkage was established to microsatellite markers located on chromosome 7q with a maximum multipoint lod score of 3.8. The region of homozygosity spans a 19 cM region that is bounded by markers D7S3046 and D7S644.     

First external quality assurance of antibody diagnostic for SARS-new coronavirus.

To confirm an infection with the new coronavirus (SARS-CoV) causing the severe acute respiratory syndrome (SARS) diagnostic assays for detection of SARS-CoV specific antibody are necessary. To evaluate the diagnostic performance of laboratories an external quality assurance (EQA) study was performed in 2004. Participating laboratories (9/20) correctly detected anti-SARS antibodies in serum samples without false positive results in an immunofluorescence assay. In contrast, only 4/13 laboratories detected most of the anti-SARS antibody positive samples without false positive results using enzyme immunoassays (EIA) and/or immunoblot. The overall results clearly demonstrate that serological diagnosis of SARS-CoV remains at an early stage of development, with further technical improvements required, particularly with respect to the use of SARS specific EIAs.     

A pharmacological study of group I muscle afferent terminals and synaptic excitation in the intermediate nucleus and Clarke's column of the cat spinal cord

Summary When administered microelectrophoretically GABA and piperidine-4-sulphonic acid depolarized the central terminations of muscle group Ia and Ib afferent fibres in the lumbar intermediate nucleus and Clarke's column of cats anaesthetised with pentobarbitone sodium. Both this depolarization, and primary afferent depolarization, generated by impulses in other primary afferent fibres which produce prolonged bicuculline-sensitive inhibition of the firing of group I afferent fibre-excited interneurones in the intermediate nucleus and cells in Clarke's column, are reduced by microelectrophoretic bicuculline methochloride. Systemically administered (±)-baclofen hydrochloride (maximum dose 8 mg kg^–1) depressed the monosynaptic excitation of Clarke's column neurones by impulses in muscle and cutaneous afferent fibres. Microelectrophoretically administered (–)-baclofen reduced the bicuculline-sensitive primary afferent depolarization of group I terminations without, however, reducing the depolarizing action of GABA or piperidine-4-sulphonic acid. The depression by (–)-baclofen of the group I monosynaptic excitation of intermediate nucleus neurones is not reduced by concentrations of bicuculline methochloride adequate to suppress prolonged inhibition of these neurones     

Differential effects of complement activation induced by cobra venom factor on pulmonary transvascular fluid and protein exchange

Sheep were prepared with lung lymph fistulas for assessment of the effects of complement activation on pulmonary transvascular fluid and protein exchange in the intact animal. Cobra venom factor (CVF 200 +/- 46 U/kg) was injected intravenously for activation of the complement system. In some animals (n = 6), pulmonary lymph flow (Qlym) and pulmonary arterial pressure (Ppa) increased without a change in the lymph-to-plasma protein concentration ratio (L/P) or in pulmonary blood flow (QL), indicating an increase in pulmonary vascular permeability to proteins. In another group (n = 6), Qlym and the L/P did not change, and there were also no changes in Ppa and QL following a similar injection of CVF. Morphologic evidence showed that leukocytes were trapped in pulmonary vessels and interstitium of both groups. Pulmonary edema was also present in both groups. Complement activation does not uniformly increase pulmonary lymph flow despite pathologic evidence of leukocyte sequestration and pulmonary edema. The lack of change in lymph flow in some animals may be due to lymphatic insufficiency, or lack of generation of humoral mediators, and/or a decrease in pulmonary capillary pressure.     

Avian cryptococcosis.

Clinical and laboratory findings in 15 unreported cases of avian cryptococcosis from Australia were collated and contrasted with 11 cases recorded in the literature. Cryptococcus species produced localized invasive disease of the upper respiratory tract of captive parrots living in Australia. This resulted in signs referable to mycotic rhinitis or to involvement of structures contiguous with the nasal cavity, such as the beak, sinuses, choana, retrobulbar space and palate. Parrots of widely differing ages were affected and of the seven birds for which sex was determinable, six were male. Cryptococcus bacillisporus (formerly C. neoformans var. gattii) accounted for four of five infections in which the species or variety was determinable, suggesting that exposure to eucalyptus material may be a predisposing factor. In these cases, Cryptococcus appeared to behave as a primary pathogen of immunocompetent hosts. One tissue specimen was available from an Australian racing pigeon with minimally invasive subcutaneous disease; immunohistology demonstrated a C. neoformans var. grubii (formerly C. neoformans var. neoformans serotype A) infection, presumably subsequent to traumatic inoculation of yeast cells into the subcutis. Two similar cases had been reported previously in pigeons domiciled in America. Data for parrots, one pigeon and other birds studied principally in America and Europe (and likely infected with C. neoformans) suggested a different pattern of disease, more suggestive of opportunistic infection of immunodeficient hosts. In this cohort of patients, the organism was not restricted to cool superficial sites such as the upper respiratory tract or subcutis. Instead, infections typically penetrated the lower respiratory tract or disseminated widely to a variety of internal organs. Finally, three captive North Island brown kiwis, one residing in Australia, the other two in New Zealand, died as a result of severe diffuse cryptococcal pneumonia (two cases) or widely disseminated disease (one case). C. bacillisporus strains were isolated from all three cases, as reported previously for another kiwi with disseminated disease in New Zealand.     

CD1 genotyping of patients with Mycobacterium malmoense pulmonary disease

Mycobacterium malmoense is an opportunistic mycobacterium that occasionally causes disease in non-immunosuppressed individuals. As only a few individuals exposed to these organisms actually develop clinical disease, it is possible there is a genetic component to susceptibility. CD1 molecules are capable of presenting antigens from more virulent mycobacteria to T cells; therefore, we were interested in discovering whether recently described polymorphisms in CD1 molecules modulated susceptibility to M. malmoense pulmonary disease. The CD1 system comprises five genes (CD1A, -B, -C, -D, and -E) located on chromosome 1 (1q22-23). CD1 molecules are structurally and functionally related to major histocompatibility complex (MHC) class I molecules and are expressed on dedicated antigen-presenting cells. The primary function of CD1 molecules is to present lipid and glycolipid antigens to T cells. We have developed an allele-specific polymerase chain reaction-sequence-specific primer (PCR-SSP) method of CD1 genotyping. Using this method, we compared the allele and haplotype frequencies of CD1 in 49 HIV-negative patients with M. malmoense pulmonary disease with those in 342 normal controls. The CD1A and CD1E alleles were nominally identified as CD1A*01, CD1A*02, CD1E*01 and CD1E*02, and the control gene frequencies were found to be 5%, 95%, 67% and 33%, respectively. No significant difference was observed between the patient and control cohorts. Positive linkage disequilibrium values of 0.73 were observed between CD1A*02 and CD1E*01 (P<0.0001; chi2 test), and 0.94 between CD1A*01 and CD1E*02 (P<0.0001; chi2 test). Typing was also performed for two previously described CD1D alleles (CD1D*01 and CD1D*02), although only CD1D*01 was detected.     

Wegener's granulomatosis. Immunomicroscopic and ultrastructural study of four cases

Four cases of Wegener's granulomatosis involving lung are reported in which immunomicroscopy demonstrated that the parenchymal and vascular infiltrates were composed primarily of T cells and monocytes. No IgG, IgA, IgM, or C3 was identified in pulmonary vessels or alveolar septa. Ultrastructural studies failed to demonstrate dense deposits in alveolar septal capillaries or interstitium. These findings indicate that a cellular immune mechanism is active in these forms of pulmonary vasculitis and that immune complex deposition does not play a role.