Development of immunofiltration assay by light addressable potentiometric sensor with genetically biotinylated recombinant antibody for rapid identification of Venezuelan equine encephalitis virus

A genetically biotinylated single chain fragment variable antibody (scFv) against Venezuelan equine encephalitis virus (VEE) was applied in a system consisting of an immunofiltration enzyme assay (IFA) with a light addressable potentiometric sensor (LAPS) for the rapid identification of VEE. The IFA involved formation of an immunocomplex sandwich consisting of VEE, biotinylated antibody, fluoresceinated antibody and streptavidin, capture of the sandwich by filtration on biotinylated membrane, and labeling of the sandwich by anti-fluorescein urease conjugate. The concentration ratio of biotinylated to fluoresceinated antibodies was investigated and optimized. By the IFA/LAPS assay, the limit of detection (LOD) of VEE was approximately 30 ng/ml, similar to that achieved when chemically biotinylated monoclonal antibody (mAb) was applied. Total assay variance of the IFA/LAPS assay for both intra- and inter-assay precision was less than 20%. Assay accuracy was measured by comparing VEE concentrations estimated by IFA/LAPS standard curve to those obtained by conventional protein assay. VEE concentrations were found to differ by no more than 10%. The IFA/LAPS assay sensitivity was approximately equal to that of a conventional enzyme-linked immunosorbent assay (ELISA) utilizing polystyrene plates and a chromogenic substrate; however, less time and effort were required for performance of the IFA/LAPS assay. More importantly, use of genetically biotinylated scFv in the IFA/LAPS assay obviates the need for chemical biotinylation of antibody with resultant possible impairment of the antigen-binding site. Furthermore, the potential for batch-to-batch variability resulting from inequality in the number of biotin molecules labeled per antibody molecule is eliminated.     

Effects of short-duration transients on cardiac rhythm

Cardiac stimulation thresholds of short-duration large-amplitude electrical transients were studied. An isolated rabbit heart model was used and transients were applied directly to the heart through electrodes of 1 mm² and 1 cm² surface area. A variety of oscillatory waveforms and pulse configurations were studied and indicated that, for transients shorter than 100 μs, stimulation thresholds approach a constant charge-transfer density of 3·4 μC cm⁻².     

The cerebrocortical microcirculatory effect of nitric oxide synthase blockade is dependent upon baseline red blood cell flow in the rat

The effects of nitric oxide synthase (NOS) blockade on the cerebrocortical microcirculation were investigated under physiological conditions in anesthetized ventilated rats using laser-Doppler (LD) flowmetry. LD flow values of the parietal cortex were determined before and after systemic administration of the NOS inhibitor N(G)-nitro-L-arginine-methyl-esther. NOS blockade reduced the LD flow significantly and the magnitude of the reduction was in close correlation with the baseline value. Synchronized sinus-wave-like LD flow oscillations were observed frequently after NOS inhibition and their appearance was also dependent on the high baseline flow values. These results indicate marked, baseline-dependent differences in the cerebrocortical blood flow response to the inhibition of the nitric oxide pathway, and may suggest that areas with high resting red blood cell flow express high NOS activity.     

Psychotherapy for depression: current and future directions in research, theory, practice and public policy

This article is based on a symposium held at the 1998 Annual Meeting of Society for Psychotherapy Research (Snow Bird, Utah). Recognized experts addressed current and future directions in psychotherapy for depression from the perspectives of process and outcome research, basic research, theoretical models, clinical practice and training, and public policy. The specific issues discussed at the symposium included the strengths and limitations of major forms of psychotherapy; the therapeutic factors common and unique to different approaches; the future viability of current theories of depression; the role of treatment manuals in clinical practice and training; the development of new interventions based on basic research; and the priorities that should guide federal funding.     

肺癌细胞外基质的表达与临床病理的关系

目的探讨原发性肺癌层粘蛋白（Ｌａｍｉｎｉｎ,ＬＮ）、纤维连接蛋白（ｆｉｂｒｏｎｅｃｔｉｎ,ＦＮ）和Ⅳ型胶原的表达与临床病理的关系。方法采用免疫组化ＬＳＡＢ法检测１８４例肺癌标本中ＬＮ、ＦＮ和Ⅳ型胶原的表达。结果ＬＮ及Ⅳ型胶原在中、高分化的肺鳞癌中的表达均明显强于低分化组（Ｐ＜００１）,在有无淋巴结转移两组间的表达差异均具显著性（Ｐ＜００５）;肺鳞癌５年以上生存组ＬＮ、Ⅳ型胶原的表达明显高于０５年内死亡组（Ｐ＜００１）,ＦＮ的表达亦有差异（Ｐ＜００５）。肺腺癌的５年以上生存组中ＦＮ、Ⅳ型胶原的表达均强于０５年内死亡组（Ｐ＜００５,００１）。结论ＬＮ和Ⅳ型胶原的表达与肺鳞癌的组织学分级和淋巴结转移有关;ＬＮ、ＦＮ、Ⅳ型胶原的表达均可作为评估肺鳞癌预后的指标,而腺癌的预后仅与ＦＮ、Ⅳ型胶原的表达有关。     

Comparison of amoxicillin with second and third generation cephalosporins in the treatment of acute otitis media

The aim of the present study was to compare the efficacy and the tolerability of three different antibiotic regimens for the treatment of acute otitis media in paediatric patients. 75 children, age range 6 months-6 years, divided into three groups, were involved in the study, each group consisting of 25 randomly assigned children (Group 1, amoxicillin 40 mg/kg tid per os for 10 days; Group 2, cefuroxime axetil 30 mg/kg bid per os for 10 days; ceftriaxone 50 mg/kg single-dose i.m.). No statistically significant difference was noted in the clinical efficacy among the different groups. Although amoxicillin is the drug of choice in paediatric otitis media, single dose ceftriaxone might be considered as an interesting alternative regimen when ease of administration and cost of therapy are considered.     

Expression of human immunodeficiency virus type 1gag gene using genetically engineered herpes simplex virus type 1 recombinants

Infectious herpes simplex virus type 1 (HSV-1) recombinants were constructed by inserting the cDNA sequence of the human immunodeficiency virus type 1 (HIV-1)gag gene (from nucleotide position 675 [SacI] to 3859 [Asp 718] of the cDNA sequences of HIV-1 strain BH-10) within the DNA sequences of theBamHI DNA fragment B of the genome of an apathogenic HSV-1 strain HFEM. This HSV-1 strain possesses a 4.1-kbp deletion within theBamHI DNA fragment B between 0.762 and 0.789 map units of the viral genome, which allows the insertion of at least 4 kbp of foreign genetic material into this particular region. The DNA sequences of the immediate early promoter (IE4) of HSV-1 that were inserted upstream from thegag gene were used as a promoter. The screening of 205 virus stocks derived from individual plaques revealed that 46 recombinant viruses harbor HIV-1gag-specific DNA sequences. However, it was found that only six of the recombinant viruses are able to express thegag gene product of HIV-1. This indicates that the ratio of the positive recombination events is about 2.9%.     

Sleep paralysis: a study in family practice

Over a period of two years, five patients with sleep paralysis referred themselves to four family practices in Israel serving a population of 6800. None of the patients suffered from daytime sleep attacks or cataplexy and all were from the oriental (sephardi) community. The two who were tissue typed had HLA haplotypes different from those which are exclusively associated with narcolepsy and one of them who also underwent polysomnography had a normal tracing. There was considerable delay in consulting a physician despite the physical and mental anguish caused by the disorder and some improvement was noted once the diagnosis was explained. The serious nature of the components of the differential diagnosis - myocardial infarction, seizure disorder, cardiac arrest, anaesthetic accident - makes it important that sleep paralysis be more widely recognized.