Increasing the activity of copper exchanged mordenite in the direct isothermal conversion of methane to methanol by Pt and Pd doping

PtCu– and PdCu–mordenite allow for isothermal reaction at 200 °C for the stepwise methane to methanol conversion with higher yields under isothermal conditions than after high temperature activation.

PtCu- and PdCu–mordenite allow for isothermal reaction at 200 °C for the stepwise methane to methanol conversion with comparably high yields. In contrast to traditional Cu-zeolites, these materials are more reactive under isothermal conditions than after high temperature activation.

Traditional medicine: past, present and future research and development prospects and integration in the National Health System of Cameroon

Traditional medicine refers to health practices, approaches, knowledge and beliefs incorporating plant, animal and mineral based medicines, spiritual therapies, manual techniques and exercises, applied singularly or in combination to treat, diagnose and prevent illnesses or maintain well-being. In the last decade traditional medicine has become very popular in Cameroon, partly due to the long unsustainable economic situation in the country. The high cost of drugs and increase in drug resistance to common diseases like malaria, bacteria infections and other sexually transmitted diseases has caused the therapeutic approach to alternative traditional medicine as an option for concerted search for new chemical entities (NCE). The World Health Organisation (WHO) in collaboration with the Cameroon Government has put in place a strategic platform for the practice and development of TM in Cameroon. This platform aims at harmonizing the traditional medicine practice in the country, create a synergy between TM and modern medicine and to institutionalize a more harmonized integrated TM practices by the year 2012 in Cameroon. An overview of the practice of TM past, present and future perspectives that underpins the role in sustainable poverty alleviation has been discussed. This study gives an insight into the strategic plan and road map set up by the Government of Cameroon for the organisational framework and research platform for the practice and development of TM, and the global partnership involving the management of TM in the country.

Progressive spastic myelopathy in a patient co-infected with HIV-1 and HTLV-II: autoantibodies to the human homologue of rig in blood and cerebrospinal fluid

OBJECTIVE

Human T-cell leukemia virus types I (HTLV-I) and II (HTLV-II) are closely related human retroviruses. HTLV-I has been implicated in a chronic progressive myelopathy, known as tropical spastic paraparesis (TSP) or HTLV-I-associated myelopathy (HAM). We sought to determine whether autoantibodies to brain antigens were present in the cerebrospinal fluid (CSF) of a patient with chronic progressive spastic myelopathy with evidence of both HIV-1 infection and HTLV-I/II seropositivity.

DESIGN

A 54-year-old bisexual man with clinical features of HAM/TSP of over 20 years' duration was followed.

METHODS

We applied discriminatory DNA amplification (polymerase chain reaction) to distinguish HTLV-I from HTLV-II and to verify co-infection with HIV-1. The patient's CSF was used to screen a human brain cDNA expression library to identify antibodies directed against brain antigens. Autoreactive bacteriophage clones were isolated and sequenced.

RESULTS

The patient was found to be co-infected with both HIV-1 and HTLV-II, but not with HTLV-I. HTLV-II proviral levels in the peripheral blood remained relatively constant, despite therapy with zidovudine. Prominent oligoclonal banding of immunoglobulins was present in the patient's CSF. A single repeatedly reactive cDNA clone was identified, by screening with CSF antibody, sequenced, and found to be the human homologue of the rat insulinoma gene, rig.

CONCLUSIONS

HTLV-II infection may predispose to development of a HAM/TSP-like illness. Autoimmune mechanisms, such as autoantibody formation, may play a role in pathogenesis.

CCD imaging of luciferase gene expression in single mammalian cells

Quantitative and sensitive imaging of chemiluminescence, bioluminescence and fluorescence emissions is emerging as an increasingly important technique for a range of biomedical applications (Hooper et al., 1990). A brief review of low-light-level imaging is presented, with particular reference to charge-coupled devices (CCD). Detectors for sensitive imaging are described and compared, including various CCDs and photon-counting devices. Image analysis techniques based on digital image processing, may be applied to quantify luminescent processes with these detectors. Images of luciferase gene expression in single mammalian cells have been obtained using a particular high-sensitivity intensified CCD camera. The method is illustrated using cell monolayers infected with recombinant vaccinia virus encoding the firefly luciferase, luc gene (Rodriguez et al., 1988). The CCD camera has been used to detect luciferase expression in single, recombinant infected cells amongst over one million non-infected cells. The rapid detection of luciferase-expressing viruses may be used for the selection of virus deletion mutants into which the luciferase gene has been cloned at specific sites. This is particularly useful in the case of viruses such as cytomegalovirus which have slow replication cycles. This direct imaging technique is simple and versatile. It offers a rapid, non-invasive method for the sensitive detection of luciferase activity in single, luciferase-expressing cells. One can envisage the use of luciferase as a sensitive and convenient co-selection marker gene in the analysis of both gene expression and protein function. These methods offer tremendous potential in the fields of molecular and cellular biology.

Choroid plexus Na+/K+-activated adenosine triphosphatase and cerebrospinal fluid formation

The quantitative relationship between intraventricular fluid formation and choroid plexus Na+/K+-activated (transport) adenosine triphosphatase (ATPase) was studied in rabbit and dog by perfusing the ventricular system with a solution containing ouabain (10(-8) to 10(-3) M). The effect of ouabain in the same range of concentrations on ATPase activity was also measured by the release of inorganic orthophosphate from in vitro choroid plexus tissue. Normally, about 20 to 25% of ATPase activity in lateral ventricle plexus is Na+/K+-activated, and this component is almost completely inhibited by ouabain in a concentration of 10(-4) M. At this concentration, the rate of intraventricular cerebrospinal fluid (CSF) formation is decreased some 70 to 80% in dog and rabbit. The results of this study suggest that a portion of the intraventricular fluid formation is insensitive to cardiac glycoside inhibition and that either there are two different mechanisms responsible for choroid plexus fluid formation or there is a significant non-ATPase dependent extrachoroidal source of CSF.