Equilibration of [3H]glucosamine and [35S]sulfate with intracellular pools of UDP-N-acetylhexosamine and 3′-phosphoadenosine-5′-phosphosulfate (PAPS) in cultured fibroblasts

Nucleotides and sugar nucleotides were extracted from cultures of human fibroblasts with perchloric acid, separated by isotachophoresis, and quantified by uv absorption analysis at 254 nm. ATP (936 pmol/μg DNA) was, as expected, the dominating nucleotide pool. The energy charge was estimated to 0.9. The UDP-N-acetylhexosamine pool was also a very prominent compound (596 pmol/μg DNA). After incubation of fibroblasts with [³H]glucosamine, more than 95% of the acid-soluble radioactivity was found in the UDP-N-acetylhexosamine pool. Incubation with [³⁵S]sulfate resulted in the incorporation of [³⁵S]sulfate into 3′-phosphoadenosine-5′-phosphosulfate (PAPS). The latter could, however, only be measured as radioactivity, as the amount was too small to be quantified as total mass. Pulse-labeling of fibroblasts with [³⁵S]sulfate and [³H]glucosamine from 5 min to 16 h showed that [³⁵S]PAPS was equilibrated in less than 10 min, while [³H]glucosamine required a longer time, 2–4 h, to attain a steady state with UDP-N-acetylhexosamine. [¹⁴C]Glucose required approximately the same time as [³H]glucosamine to reach steady state with UDP-acetylhexosamine, which suggests that the reason for the long equilibration time is the slow turnover of this pool.     

Frequency changes with time in vivo of radiation-induced chromosomal aberrations in skin fibroblasts

5 Syrian hamster litter mates were each irradiated with X-rays on one flank to 300 rad. Skin biopsies were taken from both the irradiated and unirradiated (control) flanks of each animal at one day and at about 6 months after irradiation. The cells cultured from these biopsies were used to determine the frequencies of chromosomal aberrations. During the 6-month period there were significant reductions in the frequencies of both reciprocal translocations and terminal deletions.

Translocations involving the short arm of the Y-chromosome, however, showed a significant increase during this period.

It is possible that while the latter phenomenon was due to cell selection in vivo the general fall off in translocations and deletions was the result of a long term in vivo repair mechanism or perhaps the results of certain aberrations proving to be lethal with prolonged expression times.     

Role of AIP56 disulphide bond and its reduction by cytosolic redox systems for efficient intoxication

Apoptosis‐inducing protein of 56 kDa (AIP56) is a major virulence factor of Photobacterium damselae subsp. piscicida, a gram‐negative pathogen that infects warm water fish species worldwide and causes serious economic losses in aquacultures. AIP56 is a single‐chain AB toxin composed by two domains connected by an unstructured linker peptide flanked by two cysteine residues that form a disulphide bond. The A domain comprises a zinc‐metalloprotease moiety that cleaves the NF‐kB p65, and the B domain is involved in binding and internalisation of the toxin into susceptible cells. Previous experiments suggested that disruption of AIP56 disulphide bond partially compromised toxicity, but conclusive evidences supporting the importance of that bond in intoxication were lacking. Here, we show that although the disulphide bond of AIP56 is dispensable for receptor recognition, endocytosis, and membrane interaction, it needs to be intact for efficient translocation of the toxin into the cytosol. We also show that the host cell thioredoxin reductase‐thioredoxin system is involved in AIP56 intoxication by reducing the disulphide bond of the toxin at the cytosol. The present study contributes to a better understanding of the molecular mechanisms operating during AIP56 intoxication and reveals common features shared with other AB toxins.     

谷红注射液和丁苯酞注射液联合Solitaire AB型支架取栓治疗急性缺血性脑卒中的临床研究

摘要 目的：探讨谷红注射液和丁苯酞注射液联合Solitaire AB型支架取栓治疗急性缺血性脑卒中（AIS）的临床疗效。方法：选择2018年1月到2020年12月期间攀枝花市中西医结合医院收治的AIS患者98例,依照随机数字表法分为观察组（50例）和对照组（48例）。对照组采用Solitaire AB型支架取栓治疗,观察组给予谷红注射液和丁苯酞注射液联合Solitaire AB型支架取栓治疗,两组均治疗14 d。治疗后进行临床疗效评价,比较两组治疗后的血管再通率和并发症发生率,比较两组治疗前后的美国国立卫生研究院卒中量表（NIHSS）评分、Barthel指数评分及全血高切黏度、全血低切黏度、血小板聚集率。结果：观察组的临床总有效率为84.00%（42/50）,对照组为60.42%（29/48）,两组比较差异有统计学意义（P<0.05）。观察组的血管再通率明显高于对照组（P<0.05）。两组治疗后血小板聚集率、全血低切黏度及全血高切黏度均明显低于治疗前（P<0.05）,且观察组治疗后血小板聚集率、全血低切黏度及全血高切黏度均明显低于对照组（P<0.05）。治疗后观察组Barthel指数评分明显高于对照组（P<0.05）,NIHSS评分明显低于对照组（P<0.05）。观察组的并发症发生率为6.00%（3/50）,对照组为4.17%（2/48）,两组比较差异无统计学意义（P>0.05）。结论：谷红注射液和丁苯酞注射液联合Solitaire AB型支架取栓治疗AIS的临床疗效显著,能够提高血管再通率,减轻神经功能缺损,改善患者的日常生活能力和血液流变学指标,且并发症较轻。     

Neutral endopeptidase-24.11 (NEP) deactivates PDGF- and TGF-beta-induced cell shape changes in invertebrate immunocytes

Using a cytofluorimetric assay, we found that immunocytes of the mollusc, Mytilus galloprovincialis, express CD10, a surface antigen known to be identical to neutral endopeptidase-24.11 (NEP). The spectrofluorimetric analysis demonstrates that the growth factors PDGF-AB and TGF-beta1 provoke an increase in NEP-like activity in membrane preparations from the immunocytes, but have no effect on the soluble form in the serum. On the other hand, computer-assisted microscopic image analysis reveals that NEP deactivates the PDGF-AB- and TGF-beta1-induced shape changes in immunocytes. However, Western blots show that, in solution, NEP does not cleave PDGF-AB or TGF-beta1, indicating that the inactivation is not due to proteolysis. These results suggest a functional interplay in invertebrate immunocytes between growth factors and NEP, as previously shown in vertebrate cells.     

不同种类氮肥对土壤释放N2O的影响

用培养试验模拟研究了在正常水分 ( 2 2 % )、干旱 ( 1 2 % )和高含水量 ( 32 % )条件下 ,普通碳酸氢铵 (普碳 )、尿素及新型肥料长效碳酸氢铵 (长碳 )对土壤释放N2 O的影响 ;同时考察了土壤NO-3 的形成时间和形成量 .结果表明 ,农田中施加的无机氮肥是大气中N2 O的重要来源 ,而长碳与普碳和尿素相比 ,不但可以明显延后N2 O释放高峰期出现时间 ,而且大多数情况下可以显著减少其释放量 (P <0 .0 1 ) .在 5个月的监测期内 ,与普碳和尿素相比其减少N2 O释放的比例分别为 80 .2 3和 88.41 % ( 1 2 %含水量 ) ,40 .0 0和2 7.59% ( 2 2 %含水量 ) ,无减少作用和 45.88% ( 32 %含水量 ) .本研究结果提示长碳具有作为农田生态系统N2 O减排措施的巨大潜力 ,同时暗示在农业中用长碳代替目前普遍应用的普碳 ,可以减少地下水中NO-3 引起的污染 .     

Insight into planar cell polarity

Planar cell polarity or PCP refers to a uniform cellular organization within the plan, typically orthogonal to the apico-basal polarity axis. As such, PCP provides directional cues that control and coordinate the integration of cells in tissues to build a living organism. Although dysfunctions of this fundamental cellular process have been convincingly linked to the etiology of various pathologies such as cancer and developmental defects, the molecular mechanisms governing its establishment and maintenance remain poorly understood. Here, we review some aspects of invertebrate and vertebrate PCPs, highlighting similarities and differences, and discuss the prevalence of the non-canonical Wnt signaling as a central PCP pathway, as well as recent findings on the importance of cell contractility and cilia as promising avenues of investigation.     

Effects of molybdate,sulfide, and tetrathiomolybdate on copper metabolism in rats

Species differences in the response to dietary MoO₄^2? as a metabolic antagonist of Cu are considered briefly. Suggestions that (i) the potency of MoO₄^2? as a Cu antagonist is enhanced by normally innocuous dietary concentrations of S^2? and (ii) that MoS₄^2? may be a more effective antagonist than either MoO₄^2? or S^2? were investigated in a series of studies with rats. Diets including MoS₄^2? but not of MoO₄^2? or S^2? alone promoted a decline in hepatic Cu and ceruloplasmin activity and induced clinical signs of Cu deficiency. Evidence of concurrent anomalies in the partition of Cu between tissues and in the distribution of Cu between proteins of plasma and kidney cytosol suggested that such effects were partly attributable to the development of systemic defects in Cu metabolism. The relationship of such findings to the suggested involvement of MoS₄^2? or its derivatives in the etiology of Mo-induced Cu deficiency in ruminant animals is considered.