[Control of the quality of antiretroviral medicines used in Senegal]. / Controle de la qualite des medicaments antiretroviraux utilises au Senegal.

INTRODUCTION: Success of any program to fight AIDS passes through out quality of antiretroviral medicines. The control and follow-up of the quality of these medicines constitute essential levers to guarantee quality. Our study aims to evaluate the quality of antiretroviral medicines used in Senegal by means of a mini laboratory from the German Pharmaceutical Health Fund. MATERIALS AND METHODS: The mini laboratory provides technical arsenal necessary for the analysis. To sum up, 43 samples of antiretroviral medicines have been submitted to three types of simple, quick and reliable tests which are physical and visual inspection, disintegration and thin layer chromatography. RESULTS: The obtained results give at physical and visual inspection, 9.3% of samples which are not similar. 30 samples out of 32 have a good disintegration time. About 11.6% of samples are not similar to thin layer chromatography. CONCLUSION: The control of the quality of antiretroviral medicines is necessary if we consider the number of no conform cases which are relatively important. The mini laboratory can constitute an interesting tool for technical control facilities in developing countries that suffer from a real lack of materials.

Counterfeit and substandard antimalarial drugs in Cambodia.

Counterfeit and substandard antimalarial drugs can cause death and contribute to the growing malaria drug resistance problem, particularly in Southeast Asia. Since 2003 in Cambodia the quality of antimalarial drugs both in the public and private health sector is regularly monitored in sentinel sites. We surveyed 34% of all 498 known facilities and drug outlets in four provinces. We collected 451 drug samples; 79% of these were not registered at the Cambodia Department of Drugs and Food (DDF). Twenty-seven percent of the samples failed the thin layer chromatography and disintegration tests; all of them were unregistered products. Immediate action against counterfeit drugs was taken by the National Malaria Control Program (NMCP) and the DDF. They communicated with the Provincial Health Department about the presence of counterfeit antimalarial drugs through alert letters, a manual, annual malaria conferencing and other training occasions. Television campaigns to alert the population about counterfeit drugs were conducted. Moreover, the NMCP has been promoting the use of good quality antimalarial drugs of a blister co-packaged combination of artesunate and mefloquine in public and private sectors. Appropriate strategies need to be developed and implemented by relevant government agencies and stakeholders to strengthen drug quality assurance and control systems in the country.

The adaptor molecule Disabled-2 links the transforming growth factor beta receptors to the Smad pathway.

Using a genetic complementation approach we have identified disabled-2 (Dab2), a structural homolog of the Dab1 adaptor molecule, as a critical link between the transforming growth factor beta (TGFbeta) receptors and the Smad family of proteins. Expression of wild-type Dab2 in a TGFbeta-signaling mutant restores TGFbeta-mediated Smad2 phosphorylation, Smad translocation to the nucleus and Smad-dependent transcriptional responses. TGFbeta stimulation triggers a transient increase in association of Dab2 with Smad2 and Smad3, which is mediated by a direct interaction between the N-terminal phosphotyrosine binding domain of Dab2 and the MH2 domain of Smad2. Dab2 associates with both the type I and type II TGFbeta receptors in vivo, suggesting that Dab2 is part of a multiprotein signaling complex. Together, these data indicate that Dab2 is an essential component of the TGFbeta signaling pathway, aiding in transmission of TGFbeta signaling from the TGFbeta receptors to the Smad family of transcriptional activators.

The polycystic kidney disease-1 protein, polycystin-1, binds and activates heterotrimeric G-proteins in vitro.

Analysis of the C-terminal cytosolic domain of human and mouse polycystin-1 has identified a number of conserved protein motifs, including a 20-amino-acid heterotrimeric G-protein activation sequence. A peptide specific for this sequence was synthesized and shown to activate purified bovine brain heterotrimeric Gi/Go in vitro. To test whether the C-terminal cytosolic domain of polycystin-1 stably binds G-proteins, GST-fusion constructs were used in pull-down and co-immunoprecipitation assays with purified bovine brain Gi/Go and rat brain lysates. This identified a 74-amino-acid minimal binding domain that includes the G-protein activation sequence. This region of polycystin-1, including the G-protein activation peptide and flanking amino acid sequences, is highly conserved in mouse, human, and puffer fish, lending further support to the functional importance of the minimal binding domain. These results suggest that polycystin-1 may function as a heterotrimeric G-protein coupled receptor.

Regulation of brain G-protein go by Alzheimer's disease gene presenilin-1.

To investigate a possible association between G-proteins and presenilin-1 (PS-1), a series of glutathione S-transferase-fusion proteins containing portions of PS-1 were prepared and used in vitro in binding experiments with tissue and recombinant G-proteins. The results demonstrate that the 39 C-terminal amino acids of PS-1 selectively bind the brain G-protein, Go. Addition of guanosine 5'-3-O-(thio)triphosphate promoted Go dissociation from PS-1, indicating that this domain mimics the function of G-protein-coupling domains found in receptors. The 39-amino acid synthetic polypeptide activated Go in a magnesium ion-dependent manner. Physical interaction of full-length PS-1 and Go was also demonstrated. Following transfection of Goalpha and N-terminally FLAG-tagged PS-1 in COS-7 cells, Go was immunoprecipitated by FLAG antibodies. In addition, endogenous PS-1 and Goalpha were colocalized immunocytochemically in human glioma cell lines. The results indicate that PS-1 regulates Go activities in living cells.

Matrix metalloproteinases and metalloproteinase inhibitors in human interphotoreceptor matrix and vitreous.

PURPOSE: We wished to establish which matrix metalloproteinases (MMPs) and metalloproteinase inhibitors (TIMPs) were present in human interphotoreceptor matrix (IPM) and vitreous. METHODS: IPM and vitreous were obtained from postmortem human eyebank eyes. Western immunoblots were probed with antibodies against human MMPs and TIMPs. Assays specific for elastase activity were also performed. RESULTS: Immunoblot analysis indicated the presence of MMP-1 (interstitial collagenase), MMP-2 and MMP-9 (gelatinases A and B), MMP-3 (stromelysin-1) and TIMP-1, -2 and -3 in both IPM and vitreous. MMP-7 (matrilysin) and MMP-12 (metalloelastase) were not found in either IPM or vitreous. CONCLUSIONS: This is the first demonstration of the MMPs and TIMPs in human IPM and of the TIMPs in human vitreous. While these enzymes are most likely involved in normal turnover within the extracellular matrices that surround the neural retina, they may also play a role in a number of retinal diseases, particularly proliferative diabetic retinopathy and age-related macular degeneration.

Increase in interphotoreceptor matrix gelatinase A (MMP-2) associated with age-related macular degeneration.

Matrix metalloproteinases have increasingly been shown to be associated with diseases involving neovascularization and/or abnormal cellular migration or proliferation. A number of diseases of this type affect the retina. In this study, the activity of gelatinase A (MMP-2), the most abundant matrix metalloproteinase in IPM (interphoto receptor matrix) and vitreous, was measured with respect to age in normal human donor eyes and compared to donors with age-related macular degeneration. IPM and vitreous were obtained from a total of 88 human donors. Samples for electrophoresis were normalized for protein content and subjected to quantitative gelatin zymography. The zymograms were scanned and then digitized and quantitated using the NIH 'Image' program. There was not a statistically significant change in the level of gelatinase A in IPM or vitreous as a function of age, although a slight downward trend was found in the total gelatinase A activity within the normal population. Likewise, when comparing normal and age-related macular degeneration donors, there was not a significant difference in the gelatinase A level in vitreous or in retina-associated IPM. However, the level of gelatinase A was nearly doubled specifically in retinal pigment epithelium-associated IPM from eyes with age-related macular degeneration [0.99 +/- 0.09 U mg-1 (56) vs 1.71 +/- 0.28 U mg-1 (14) (mean +/- S.E.M. (number), P < 0.0021; 1 unit = 1.0 ng gelatin cleaved h-1). Gelatinase A may be associated with the changes that occur in age-related macular degeneration, especially the neovascularization which accompanies the exudative ('wet') form of the disease.

Membrane type-1 matrix metalloproteinase in human ocular tissues.

PURPOSE: Membrane type-1 matrix metalloproteinase (MT1-MMP) (MMP-14) (EC 3.4.24.xx) is involved in the activation of progelatinase A (MMP-2) (EC 3.4.24.24). MMP-2 is present at least in the interphotoreceptor matrix and vitreous. The purpose of this study was to determine the distribution of MT1-MMP, and MMP-2, in human ocular tissues. METHODS: The distribution of MT1-MMP and MMP-2 was investigated in vitreous and in membrane extracts from eye tissues obtained from postmortem human eyebank eyes. Western blot analysis was performed using mouse monoclonal anti-MT1-MMP and anti-MMP-2 antibodies. RESULTS: MT1-MMP was found in sclera, cornea, lens, choroid, retinal pigment epithelium (RPE) and retina. MMP-2 was found in sclera, cornea, choroid, vitreous, RPE and retina but was absent from lens. CONCLUSION: We provide the first evidence for the presence and distribution of membrane-type-1 matrix metalloproteinase in human ocular tissues. MT1-MMP may be responsible for the activation of progelatinase A in many ocular extracellular matrices in a manner similar to that exhibited in other systems.

Purification and characterization of two pancreatic elastase isoforms from dogfish (Scyliorhinus canicula).

Two elastase isoforms were isolated from activated pancreatic extract of dogfish (Scyliorhinus canicula). The purification procedures for both elastases included ammonium sulfate fractionation, ion exchange on DEAE cellulose and Mono-QHR column followed by gel filtration on PL-GFS (HPLC) column. The two isoenzymes, EI and EII, exhibit a high activity toward the specific elastase substrate succinyl-(ala)3-p-nitroanilide (SANA) with different kinetic parameters at 37 degrees C. However, the two different enzymes have similar properties on the basis of pH, temperature, and molecular weight study. The activity of both variants was completely inhibited by elastatinal, phenylmethyl sulfonyl fluoride, (PMSF), diisopropyl fluorophosphate, (iPr2-FP), but less by p-chloromercuribenzoic acid (PCMB) and soybean trypsin inhibitor. EI and EII have similar amino acid composition; their amino-terminal sequences have 85% homology with human and rat elastase 2.