Differential partitioning of tRNAs between micellar and aqueous phases: a convenient gel filtration method for separation of tRNAs

A case of Blue Rubber Bleb Nevus in a 11 year-old boy is reported. The patient exhibited characteristic hemangiomas of the skin and gastrointestinal tract with an iron deficiency anemia. Historical, clinical, pathological, and surgical features of the condition are discussed. Value of fibroscopic examination in delineation of the cause of persistent gastrointestinal bleeding is pointed out.     

Inhibition of the flocculation of bacteria by biopolymers

Bacterial flocculation is an important phenomenon in secondary waste treatment. Polymers produced by bacteria control the flocculation process. We used the bacterium Leuconostoc as a model in a study of the effect of bacterial polymers on flocculation.Leuconostoc mesenteroides is known to synthesize extracellular dextran when sucrose is used as a substrate. Dextran is not normally produced by glucose-grown cells. Sucrose-grown cells of Leuconostoc failed to flocculate, while glucose-grown cells formed visible flocs. Removal of dextran from sucrose-grown cells stimulated aggregation. Artificial polymers and clays interacted with stable suspensions of Leuconostoc to yield aggregates. The presence of large quantities of natural or artificial polymers can act to stabilize bacterial suspensions and prevent flocculation.     

Photoageing-associated mitochondrial DNA length mutations in human skin

It has recently been suggested that mitochondrial DNA (mtDNA) mutations are important contributors to human ageing and degenerative diseases. Using PCR techniques, we demonstrated three types of mtDNA length mutations, a 4977 bp deletion, a 7436 bp deletion and tandem duplications, in normal human skin tissues. We found that these mutations started to appear in the third decade of life, and the age at which the mutations could be detected in sun-exposed skin was usually younger than in non-exposed skin. Moreover, the incidences of these deletions and tandem duplications of mtDNA in sun-exposed skin were all significantly higher than those in non-exposed skin (P < 0.05). The 4977 bp deletion was the most prevalant mtDNA mutation in human skin, and the 7436 bp deletion was the least frequent among the three types of mtDNA mutations examined. We first demonstrated the existence of tandem duplications with sizes of about 260 bp, 200 bp and 150 bp in the D-loop region of mtDNA in the skin of elderly individuals. Among the three tandem duplications, the 200-bp duplication was found to occur most frequently in ageing skin. The tandem duplications were found to coexist with either or both of the deletions in some elderly individuals. The frequency of occurrence of mtDNA deletions and tandem duplications in skin was found to increase in an age-dependent manner. However, the incidence of tandem duplications was not well correlated with the age of the subject.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pharmacokinetic interactions and side effects resulting from concomitant administration of lithium and divalproex sodium

BACKGROUND: Valproic acid is added to the lithium regimens of many patients with bipolar disorder, especially those with mania refractory to lithium treatment. METHOD: We evaluated the pharmacokinetic effects and safety of coadministration of lithium and valproate in 16 healthy volunteers in this randomized, placebo-controlled, two-period (12 days each) crossover trial. Valproate or placebo was given twice daily. On Days 6-10, lithium was added. Blood samples drawn on Days 5 and 10 were analyzed for valproate by high-pressure liquid chromatography (HPLC) and for lithium by atomic absorption spectrophotometry. RESULTS: Lithium pharmacokinetics were unchanged by valproate, but valproate C(max), C(min), and AUC rose slightly during lithium coadministration. Adverse events did not change significantly. CONCLUSION: Concomitant administration of lithium and valproate appears to be safe in patients with bipolar disorder.     

A placebo-controlled trial of recombinant human ciliary neurotrophic (rhCNTF) factor in amyotrophic lateral sclerosis. rhCNTF ALS Study Group

Preclinical investigations indicated that recombinant human ciliary neurotrophic factor (rhCNTF) may have potential as therapy for amyotrophic lateral sclerosis (ALS). We evaluated the safety and efficacy of rhCNTF in a prospective, double-blind, placebo-controlled trial in 570 patients with ALS. Patients were randomized to receive 0.5, 2, or 5 micrograms/kg/day rhCNTF, or placebo, for 6 months. The primary efficacy end point was the change from baseline to the last on-treatment value of a combination megascore for limb strength (maximum voluntary isometric contraction) and pulmonary function. Secondary end points included individual arm and leg megascores, pulmonary function tests, an activities-of-daily-living outcome measure, and survival. The four treatment groups were similar at baseline with respect to age, sex, disease duration, and muscle strength values. At all doses tested, rhCNTF had no beneficial effect on the primary or secondary end points. Certain adverse events, as follows, appeared to be dose related: injection site reactions, cough, asthenia, nausea, anorexia, weight loss, and increased salivation. There was an increased number of deaths at the highest dose level. rhCNTF had no beneficial effect on any measure of ALS progression. There were increased adverse events in the 5 micrograms/kg group and increased deaths.     

A microcomputer-based system for measuring excitation functions with good energy resolution

A system is described which removes time dependent energy fluctuations from a proton beam incident on solid targets. Operating under microcomputer control, this system permits automatic measurement of extended (several MeV) excitation functions with very good energy resolution ( 300 eV FWHM) for thin solid targets. The long-term energy stability of this system has been measured to be 0.0003%/h at E_p = 2.0 MeV, with a short-term energy spread of σ = 5 eV.     

Specific migration of di-(2-ethylhexyl)adipate (DEHA) from plasticized PVC film: results from an enforcement campaign

A control campaign on the correct labelling of plasticized PVC film according to current legislation on food contact materials has been performed. Analytical methods based on the isotope dilution technique were developed. For enforcement purposes, the films were exposed to the official food simulant, olive oil, followed by clean-up using size exclusion chromatography and final determination of di-(2-ethylhexyl) adipate (DEHA) by combined capillary gas chromatography and mass spectrometry (GC-MS). In the initial screening, the samples were exposed to the alternative food simulant, isooctane, and DEHA could be determined by GC-MS without further clean-up. A good consistency between results from the two different methods was obtained. During the campaign, 49 samples of PVC films, the majority intended for use in retail shops, were sampled from importers and wholesalers by the Municipal Food Control Units. Initially, all films were screened for the migration into isooctane (exposed 2 h at 40 degrees C) of DEHA and other potentially present low molecular weight plasticizers using full scanning mass spectrometry. Films showing a substantial migration of DEHA were further tested with olive oil according to the declared field of application (exposed for 10 days at 40 degrees C). In 47 of the 49 films the migrate contained a substantial amount of DEHA. In 46 films the migration exceeded the specific migration limit of 3 mg/dm2 after use of the relevant reduction factor given in legislation. However, because of the general uncertainty of the analytical method and because the variation in the thickness of the films was calculated to be 1 mg/dm2, the action limit in this campaign was 4 mg/cm2. A migration higher than this action limit was found in 42 films (89% of the samples) and these films were deemed to be illegal according to their present declared field of application as given by their labelling. In a few cases, some migration of the plasticizer di-n-butyl phthalate was seen.