Dynamic course of neurological syndromes in very young children with the history of intrauterine growth retardation

90 infants with intrauterine growth retardation (IGR) and 100 normal infants (control group) were followed up from 5 days till 3 years of life. In IGR infants there was a more frequent combination of several neurologic syndromes, an early manifestation of motor disorders (from the very moment of birth), a delay of neuro-psychic development (during the first year of life), a tendency to development of moderate hydrocephalus by the age of 6 months. Autonomic-visceral disorders in them were mostly characterized by the symptoms of abaissement, but not of irritation.     

Suc-Phe-Leu-Phe-SBzl--a new substrate for functional study of Escherichia coli ATP-dependent Lon-proteinase and its modified forms

A new efficient substrate, Suc-Phe-Leu-Phe-SBzl, was proposed for studying the function of the Escherichia coli ATP-dependent Lon protease and its modified forms. The kinetic parameters of hydrolysis of the substrate were determined. The esterase activity of protease Lon was found to be nucleotide-regulated.     

Randomised trial of heroin maintenance programme for addicts who fail in conventional drug treatments

OBJECTIVE: To evaluate an experimental heroin maintenance programme. Design: Randomised trial. SETTING: Outpatient clinic in Geneva, Switzerland. SUBJECTS: Heroin addicts recruited from the community who were socially marginalised and in poor health and had failed in at least two previous drug treatments. INTERVENTION: Patients in the experimental programme (n=27) received intravenous heroin and other health and psychosocial services. Control patients (n=24) received any other conventional drug treatment (usually methadone maintenance). Main outcome measures: Self reported drug use, health status (SF-36), and social functioning. RESULTS: 25 experimental patients completed 6 months in the programme, receiving a median of 480 mg of heroin daily. One experimental subject and 10 control subjects still used street heroin daily at follow up (difference 44%; 95% confidence interval 16% to 71%). Health status scores that improved significantly more in experimental subjects were mental health (0.58 SD; 0.07 to 1.10), role limitations due to emotional problems (0.95 SD; 0.11 to 1.79), and social functioning (0.65 SD; 0.03 to 1.26). Experimental subjects also significantly reduced their illegal income and drug expenses and committed fewer drug and property related offences. There were no benefits in terms of work, housing situation, somatic health status, and use of other drugs. Unexpectedly, only nine (38%) control subjects entered the heroin maintenance programme at follow up. CONCLUSIONS: A heroin maintenance programme is a feasible and clinically effective treatment for heroin users who fail in conventional drug treatment programmes. Even in this population, however, another attempt at methadone maintenance may be successful and help the patient to stop using injectable opioids.     

The development and cross-validation of methods based on radioimmunoassay and LC/MS-MS for the quantification of the class III antiarrhythmic agent, MK-0499, in human plasma and urine

An analytical method based on radioimmunoassay (RIA) has been developed for the determination of the antiarrhythmic agent, MK-0499, in plasma and urine. Owing to the potency of the drug, the specificity of this assay in human plasma could not be adequately determined using conventional RIA procedures. A highly specific procedure, based on LC/MS-MS, was developed to cross-validate the RIA. The lower quantifiable limits of the RIA and LC/MS-MS-based methods were 0.05 and 0.013 ng ml-1, respectively. Cross-validation data, compared using paired student's t-test regression analysis, showed excellent correlation between methods. The mass spectrometric assay was also used to simultaneously measure plasma concentrations of unlabeled and 14C-labeled MK-0499 following administration of the drug at high specific activity to volunteers.     

The modulation of cellular responses to poly(2-hydroxyethyl methacrylate) hydrogel surfaces: phosphorylation decreases macrophage collagenase production in vitro

We examined the regulation of collagenase production by the monocyte/macrophage THP-1 cell line when these cells were exposed to poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel surfaces with different chemistries and morphologies. Tissue culture modified polystyrene (TCP), used as a control surface, induced the maximum collagenase response. Copolymer hydrogels containing 2-ethoxyethyl methacrylate (EMA) or methyl methacrylate (MMA) also induced a high response, while PHEMA hydrogels induced a low level response and the phosphorylated hydrogel induced no response. This pattern was altered when the morphology of the hydrogels was changed to that of a sponge. The overall enzyme response to the sponge hydrogels was lower than that to the homogeneous hydrogels. Sponges containing EMA and MMA produced low level response relative to the TCP control. PHEMA and phosphorylated sponges produced little and no response respectively. The dramatically reduced enzyme response to phosphorylated surfaces was not a consequence of cell death, and may be a phenomenon related to changes in cell surface charge.     

Use of the method of mixed substrates to study the specificity of tRNA methylases

The absence of summation of the rate of methylation of positionally analogous cytidine residues in tRNA1Val, tRNAPhe, and tRNAMet in the case of simultaneous presence of two substrates in the incubation mixture was demonstrated by the method of mixed substrates. The same result was also obtained in the methylation of A19 (counting from the 3' end of the molecule) in tRNA1Val, tRNAPhe, tRNAfMet, tRNASer, and tRNAGlu individually and in the case of their mixing in pairs. These data are evidence that positionally analogous nucleotides in different RNAs are attacked by the same enzyme. Yeast tRNASer, already possessing a methyl group at the cytidine residue studied, proved to be an effective inhibitor of methylase, forming m5C with valine and phenylalanine tRNAs. The results obtained are evidence that differences in the primary and secondary structures at the site of methylation are not the deciding factors in the interaction of tRNA with methylases.     

Behavior of decomposition of rifampicin in the presence of isoniazid in the pH range 1-3

The extent of decomposition of rifampicin in the presence of isoniazid was determined in the pH range 1-3 at 37°C in 50 min, the mean stomach residence time. With increase in pH, the degradation initially increased from pH 1 to 2 and then decreased, resulting in a bell-shaped pH-decomposition profile. This showed that rifampicin degraded in the presence of isoniazid to a higher extent at pH 2, the maximum pH in the fasting condition, under which antituberculosis fixed-dose combination (FDC) products are administered. At this pH and in 50 min, rifampicin decomposed by ~ 34%, while the fall of isoniazid was 10%. The extent of decomposition for the two drugs was also determined in marketed formulations, and the values ranged between 13-35% and 4-11%, respectively. The extents of decomposition at stomach residence times of 15 min and 3 h were 11.94% and 62.57%, respectively, for rifampicin and 4.78% and 11.12%, respectively, for isoniazid. The results show that quite an extensive loss of rifampicin and isoniazid can occur as a result of interaction between them in fasting pH conditions. This emphasizes that antituberculosis FDC formulations, which contain both drugs, should be designed in a manner that the interaction of the two drugs is prevented when the formulations are administered on an empty stomach.     

Industry case studies in the use of immersive virtual assembly

In this paper, we report on two engineering case studies that have been conducted as part of a Virtual Assembly Technology Consortium. The objectives of the case studies were to determine if immersive virtual assembly capabilities allow industry assembly situations to be modelled and studied realistically, and to demonstrate the downstream value of the virtual assembly capabilities in areas such as ergonomics, assembly installation, process planning, installation, and serviceability. What is of special significance is that instead of modelling simplified problems or perceived representative situations, the case studies were constructed from actual assembly floor projects and situations encountered at industry member sites and with considerable participation from industry engineers and manufacturing shop floor personnel. Based on the success of the case studies, the consortium members inferred that virtual assembly methods are poised to move out of the realm of special projects and test scenarios to deployment in the actual design and manufacturing cycle. However, in order to be truly accepted in industry, there are still issues to be addressed in terms of ease of use, portability of the applications, and preparation of the models for the evaluations. Thus, the case studies added a new dimension to the exploration and understanding of how this new technology could be of practical value in industry.     

下一代通信技术对广播电视业务发展的影响(下)

(接上期第43页) 3 下一代通信接入对广播电视业务发展的影响 3.1 突破用户接入的瓶颈 随着宽带业务的发展,网络接入部分(最后1 km)的带宽瓶颈问题显露出来.目前,接入部分两侧都已跨入吉比特级以上的速率,如用户端广泛使用的PC,其内部传送速率已达到32 Gb/s,城域网或长途网的每波长速率也已达到2.5～10 Gb/s,两者都比接入部分高出至少3个数量级.可见,尽快打通接入部分的带宽瓶颈,各种宽带服务与应用才能开展起来,网络容量的潜力才能真正发挥.