Stop codon in the procollagen II gene (COL2A1) in a family with the Stickler syndrome (arthro-ophthalmopathy).

Linkage analysis with restriction fragment length polymorphisms for the gene for type II procollagen (COL2A1) was carried out in a family with the Stickler syndrome, or arthro-ophthalmopathy, an autosomal dominant disorder that affects the eyes, ears, joints, and skeleton. The analysis demonstrated linkage of the disease and COL2A1 with a logarithm-of-odds score of 1.51 at zero recombination. A newly developed procedure for preparing cosmid clones was employed to isolate the allele for type II procollagen that was linked to the disease. Analysis of over 7000 nucleotides of the gene revealed a single base mutation that altered a CG dinucleotide and converted the codon CGA for arginine at amino acid position alpha 1-732 to TGA, a stop codon. From previous work on procollagen biosynthesis, it is apparent that the truncated polypeptide synthesized from an allele with a stop codon at alpha 1-732 cannot participate in the assembly of type II procollagen, and therefore that the mutation would decrease synthesis of type II procollagen. It was not apparent, however, why the mutation produced marked changes in the eye, which contains only small amounts of type II collagen, but relatively mild effects on the many cartilaginous structures of the body that are rich in the same protein.     

Use of spleen organ cultures to monitor hemopoietic progenitor cell regeneration following irradiation and marrow transplantation

After lethal irradiation of C57BL mice followed by the injection of 10(7) marrow cells, total cellularity and progenitor cell levels exceeded pretreatment levels within 12 days in the spleen, but regeneration remained incomplete in the marrow. The exceptional regenerative capacity of progenitor populations in the spleen was observed in organ cultures of spleen slices prepared 24 hr after irradiation and transplantation, excluding continuous repopulation from the marrow as a significant factor in splenic regeneration.     

Comparative efficacy of chloroquine and sulfadoxine-pyrimethamine for uncomplicated Plasmodium falciparum malaria and impact on gametocyte carriage rates in the East Nusatenggara province of Indonesia

The efficacy of chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) was evaluated in 89 subjects greater than one year of age with uncomplicated P. falciparum malaria in the East Nusatenggara Province of Indonesia. Fever clearance time was longer in the SP group than in the CQ group. However, parasite clearance time was extended in subjects who received CQ compared with those who received SP. Major adverse events were not observed in either group, and no hospitalizations were required during the study. Treatment failure rates at day 28 were 69% for CQ and 8.5% for SP. In both treatment groups, gametocytemia developed during the follow-up period, but was more pronounced in the SP group, peaking at 94% on day 7. Regardless of treatment group, children < 10 years of age had significantly higher treatment failure rates than subjects >/=10 years of age (relative risk = 2.49), suggesting that acquired immunity influenced treatment outcomes in the presence of parasite drug resistance. Although a highly effective alternative to CQ for clearing infection, SP treatment also presented some potential drawbacks (e.g., increased and persistent gametocytemia). Replacement of CQ with SP as a first-line therapy, either alone or in combination with CQ, in those areas of Indonesia with high levels of CQ resistance should significantly improve treatment outcomes, particularly in vulnerable populations lacking clinical immunity. More efficacious and rapidly acting asexual stage treatments are generally associated with increased gametocyte clearance and combination therapy in areas where drug resistance is high or emerging may provide an additional means for reducing transmission.     

A community-based TB drug susceptibility study in Mimika District, Papua Province, Indonesia.

SETTING: A district level tuberculosis (TB) control programme in Papua Province, Indonesia. OBJECTIVE: To determine the nature and extent of drug-resistant TB in newly diagnosed sputum smear-positive patients. METHODS: Sputum was collected from previously untreated smear-positive pulmonary TB patients diagnosed in the district over a 10-month period. Sputum specimens were processed and inoculated into a BACTEC MGIT960 tube. Isolates were identified by Ziehl-Neelsen staining, hybridisation with nucleic acid probes and biochemical investigations. Susceptibility testing was performed using the radiometric proportion method. Pyrazinamide testing was performed using the Wayne indirect method. RESULTS: One hundred and seven patients had sputum sent to a reference laboratory; 101 (94.4%) were culture-positive for Mycobacterium tuberculosis, with 87 (86.1%) fully sensitive to first-line anti-tuberculosis drugs. Two per cent were multidrug-resistant (MDR-TB) and 12 (11.9%) had other drug resistance. Each of the MDR-TB isolates was susceptible to amikacin, capreomycin, ciprofloxacin and para-aminosalicylic acid (PAS), but were resistant to rifabutin. One isolate was also resistant to ethionamide. CONCLUSIONS: MDR-TB is present in Indonesia but is not a major problem for TB control in this district. Generalisability to other districts in Indonesia, particularly large urban areas, needs to be confirmed by future studies.     

Homocysteine, renal disease and cardiovascular disease in a remote Australian Aboriginal community

BACKGROUND: Rates of renal and cardiovascular disease are high among Aboriginal Australians living in remote communities. Nutritional problems, in particular low folate levels, are also common. This suggests that increased homocysteine concentrations might be widespread, and a possible contributor to the high rates of cardiovascular disease. AIMS: To examine homocysteine concentrations, and their relationships to folate levels, and to markers of renal disease and cardiovascular disease in a remote Aboriginal Australian community METHODS: As part of a cross-sectional survey among adults in one community, homocysteine concentrations, concentrations of the crucial determinants (red blood cell (RBC) folate, vitamin B(12) and the C677T methylene tetrahydrofolate reductase polymorphism) and cardiovascular risk factors were examined. RESULTS: Among 221 people, geometric mean homocysteine concentration was 11.8 micromol/L (range: 11.1-12.5 micromol/L), with 57/221 (26%) values > or =15.0 micromol/L. Higher concentrations were associated with older age, male gender, lower RBC folate and lower vitamin B(12) concentrations and homozygosity for C677T. Homocysteine concentrations were not related to the presence of albuminuria, other than over the overt albuminuria range. Homocysteine concentrations were inversely correlated with calculated glomerular filtration rate (GFR). Carotid intima-media thickness, however, was not related to homocysteine concentration. In multivariate analyses, age, male gender, lower RBC folate concentrations, lower vitamin B(12) concentrations, lower calculated GFR and the C677T polymorphism were all associated with homocysteine concentrations. CONCLUSIONS: Homocysteine concentrations were consistent with previous limited reports in Aboriginal communities. Although superficially they are similar to reports from non-Aboriginal settings, the younger age of this cohort and the association of homocysteine concentrations with age suggest that age-specific concentrations are higher among Aboriginal Australians. In addition to dietary determinants, the high prevalence of apparently reduced renal function renal disease appears to be an important determinant of homocysteine concentrations in remote Aboriginal communities. The role of homocysteine concentrations as a potential mediator of the high rates of cardiovascular disease remains to be determined.     

Gene Therapy for the Nervous System: Challenges and New Strategies

Current clinical treatments for central nervous system (CNS) diseases, such as Parkinson’s disease and glioblastoma do not halt disease progression and have significant treatment morbidities. Gene therapy has the potential to “permanently” correct disease by bringing in a normal gene to correct a mutant gene deficiency, knocking down mRNA of mutant alleles, and inducing cell-death in cancer cells using transgenes encoding apoptosis-inducing proteins. Promising results in clinical trials of eye disease (Leber’s congenital aumorosis) and Parkinson’s disease have shown that gene-based neurotherapeutics have great potential. The recent development of genome editing technology, such as zinc finger nucleases, TALENS, and CRISPR, has made the ultimate goal of gene correction a step closer. This review summarizes the challenges faced by gene-based neurotherapeutics and the current and recent strategies designed to overcome these barriers. We have chosen the following challenges to focus on in this review: (1) delivery vehicles (both virus and nonviral), (2) use of promoters for vector-mediated gene expression in CNS, and (3) delivery across the blood-brain barrier. The final section (4) focuses on promising pre-clinical/clinical studies of neurotherapeutics.