[Genotoxicity of herbicide 83-1 in yeast assay system]

The genotoxicity of Herbicide 83-1 (Dichloronitrophenolamide, DCNPA) was detected by the yeast D61.M and D7 assay with multi-endpoint. We noted that the frequency of cyhR (resistance to cycloheximide) colonies of D61.M treated with DCNPA on cycloheximide medium was much higher than that of the control (P < 0.01) and that there was a dose-response relationship. These showed that the positivity responsed to the mitotic crossing-over endpoint. To the remaining endpoints in the D61.M and D7 assay, however, the negative response was obtained. The results have demonstrated that Herbicide 83-1 is a DNA damage agent.

Phenotypic conversion of SV40-immortalized human diploid fibroblasts to senescing cells by introduction of an antisense gene for SV40-T antigen

Normal human lung fibroblast diploid cells, WI-38, become senescent after a definite number of divisions. VA-13 is a line of immortalized cells established by transformation of WI-38 cells by SV40 virus. To determine whether SV40 large T (SV40-T) antigen is essential for this immortalization of WI-38 cells we introduced an antisense gene for T antigen into VA-13. Two morphologically different types of antisense transformant (VA-AS5-8 and VA-AS37-8) were obtained. In both antisense transformants the expression of T antigen was reduced by more than 70% as compared to that in the parent cells. The morphology of the antisense transformants indicated a partial conversion to the senescent phenotype of WI-38. The relative number of cells in the S phase of the antisense transformants was decreased as compared to that in cultures of VA-13 and about 50% of cells were at G1/0. The doubling time of the transformants was prolonged to close to the doubling time of WI-38. The level of expression of retinoblastoma protein (pRB) complexed with SV40-T antigen of the antisense transformants was significantly decreased although the level of total pRB was much higher than that in VA-13. The pRB was present exclusively in the underphosphorylated form. Thus, the decreased level of formation of the complex between SV40-T and pRB or the underphosphorylation of pRB may explain the suppression of growth of antisense transformants. Together, these results show that an antisense gene for SV40-T antigen can efficiently block the cell proliferation and the cell immortalization of VA-13 cells.

Inhibition of expression of a mouse alpha-globin gene by plasmids that include antisense oligonucleotides

Plasmid-borne DNAs, corresponding to 68-base oligodeoxynucleotides, synthesized in the antisense or sense configuration and based on the nucleotide sequences of various regions of the mouse alpha-globin mRNA, were introduced with the gene for xanthine-guanine phosphoribosyl transferase from E. coli (Ecogpt) into mouse erythroleukemia (MEL) cells by protoplast fusion. Specific inhibition of the synthesis of alpha-globin was observed only in the cells transformed with the plasmids with antisense 68-mers that corresponded to the cap site as well as the site of initiation of translation of alpha-globin mRNA (Oligo-A); Other plasmids with antisense 68-mers that corresponded to the regions of the exon/intron junctions, the individual exons, or the 3' untranslated region were ineffective. This antisense RNA efficiently reduced the production of alpha-globin to 9-18% of the endogenous level after induction with hexylmethylene-bis-acetoamide (HMBA). Moreover, most of the antisense transformants did not show any decrease in the expression of the c-myc gene at the early phases of differentiation of MEL cells. Thus, we propose a hypothesis that the early decline in levels of c-myc mRNA may be independent of and uncoupled from the program of globin synthesis during the differentiation of MEL cells.

[Veno-valvulectomy and primary in situ arteriolization of the great saphenous vein for the treatment of ischemic lower limbs]

After the study of the valvular distribution of 18 cadaveric great saphenous veins, we performed microsurgically great saphenous veno-valvulectomy and primary in situ veno-arteriolization for 18 severely ischemic limbs of 17 patients of these patients, 14 had thromboangiitis obliterans, and 3 arteriosclerosis. 16 patients were followed up for 14 to 32 months after operations. The results were excellent. The procedure is a good alternative for the treatment of extensive arterial occlusive disease of the lower limbs.

Generation of 19 STS markers that can be anchored at specific sites on human chromosome 21

Sequence-tagged sites (STSs) are short stretches of DNA that can be specifically detected by the polymerase chain reaction (PCR) and can be used to construct long-range physical maps of chromosomal DNA. These STSs can be detected by PCR assays developed by reference to data obtained from the sequencing of restriction fragment length polymorphism-DNA markers for chromosome 21, which were derived from recombinant lamba-phage and plasmid clones made from DNA of a human-hamster hybrid cell line. In this report, we describe the generation of 19 new STSs that are specific for human chromosome 21.

[Transcranial magnetic motor evoked potentials (MEP) and somatic sensory evoked potentials (SEP) in the management of cervical spondylitic myelopathy (CSM)]

Fourteen CSM patients with clinical findings of myelopathy had their diagnoses proved with MRI imaging and at operation. There were a control group of 28 normal subjects for MEP and another control group of 32 for SEP. The results of the study showed that 72.7% had MEP abnormality with prolongation of the central motor conduction time (CMCT) in 7 cases and absence of motor action potentials after C7 stimulation in one of the 11 patients. In 2 patients with prolongation of CMCT, normal SEPs were found in the same arm while 1 patient showed directly a reversal of the results. The short-term follow-up study in 10 patients showed normalization of the prolonged CMCT in one and reappearance of motor action potentials with C7 stimulation in another. The authors considered that the non-invasive and painless, transcranial magnetic stimulation of the motor pathways might be useful in the assessment and management of CSM patients and better than the electrical stimulation.

[Constituents of essential oils from leaves, stems, and fruits of Perilla frutescens (L.) Britt]

The constituents of essential oils obtained from the leaves, stems, and fruits of Perilla frutescens were analysed by GC-MS. 65 compounds including perilla aldehyde, perilla alcohol, trans-caryophyllene and hexadecanoic acid, etc. were identified. Their percentages in the oils were given.

[Determination of magnolol and honokiol in 3 species of houpo (corter Magnoliae) of different ages by HPLC]

Based on the method of assessing the growing age of trees by "annual ring in the bark", the active ingredients magnolol and honokiol in 3 species Houpo (Magnolia officinalis, M. biloba, M. rostrata) of different ages, were determined by HPLC. The results present a reference for defining the reasonable period of collection and quality evaluation of Houpo.

[Analysis of essential oil from Libanotis laticalycina Shan et Sheh. by GC-MS]

60 chemical components of the essential oil from Libanotis laticalycina were identified. The contents of these components were determined by GC.

Inhibition of HIV replication by baicalin and S. baicalensis extracts in H9 cell culture

Crude extracts of Scutellia baicalensis and a particular low molecular weight substance known as Baicalin were shown to inhibit HIV antigen expression in H9 cell culture, with 50% inhibitory doses of 0.6 microgram/ml and 3.3 micrograms/ml, respectively. They also inhibited P24 antigen production in H9 cells, with IC50's of 1.94 and 4.74 micrograms/ml, respectively. Cytoxicity was tested in H9 and HUT78 cells: Both exhibited relatively low levels of cytoxicity. These results indicated that S. baicalensis and Baicalin strongly inhibit HIV replication in cell culture.

[Relation between the clinical manifestations and electromyographic findings in motor neurone disease]

343 cases of motor neurone disease (MND) were examined with electromyography. The result showed EMG examination was of much vale in helping to ascertain an accurate diagnosis which clinically could be made in only about 1/4 of the series of cases. The ages of onset ranged from 4 months to 10 years with an average of 36.8 years. 56.8% under 40 years. There was a higher male preponderance, the male/female ratio being 3.2:1. It was 1.6:1 in a report from a western country. 123 cases showed only one limb involvement clinically while the EMG findings were also abnormal in the other three limbs. Fibrillation potentials were found to be at more than two sites in one muscle in 84.5% in this series, where as they occurred in 95-100% of the infantile and juvenile cases. Abundant fibrillation potentials were found in 37.1% of the cases within 3 years after the onset and in 13.6% in those with a longer duration. The increment of the mean duration of motor unit potential was 94.5% and that of the mean amplitude 91%. It seemed not necessary to emphasize giant potentials. The motor nerve conduction velocities (NCV) were normal in 95% while the sensory NCV were almost always normal (98%). All of the 3 cases tested with single fiber EMG showed an increment of jitter of 95-100% and a muscle fiber density of 2.95-3.65.

[Inhibition of human immunodeficiency virus reverse transcriptase in vitro by extracts of Chinese medicinal herbs]

Thirty-three chinese medicinal herbs reputed by ancient chinese folklore to have anti-infective properties were extracted. The extracts and their compounds were tested for inhibitory activity against the human immunodeficiency virus RT in vitro. 8 of the 33 extracts were found to be active. Of these, MBAA9045 was studied in greater depth. We found that it was a noncompetitive inhibitor against HIV-RT. The concentration of MBAA9045 reducing HIV-RT activity by 50% (IC50) was 22 mumol/L. Chinese medicinal herbs appear to be a rich source of potentially useful materials for the treatment of human immunodeficiency virus infection.

[Observation of efficacy of different dialytic therapies in renal transplantation preparation]

Fifty-seven cadaveric renal transplantations in fifty-five cases were analysed of them, thirty cases were prepared by continuous ambulatory peritoneal dialysis (CAPD group); twenty-seven transplantations in twenty-five cases were prepared by hemodialysis (HD group). Our data show that there is no significant difference in the survival duration between CAPD group and HD group; that there is also no significant difference in the survival duration between the two groups treated with the same immunosuppressive drugs, and that patients prepared by CAPD have a low risk of peritonitis after transplantation. It is better not to remove the Tenckhoff catheter until the graft function is stable so that it can be used for the transient peritoneal dialysis in the case of the insult of graft function or for the sampling of the peritoneal effusion for diagnosis of suspectable peritonitis after renal transplantation.