A cytoplasmic thyroid hormone binding protein: characterization using monoclonal antibodies

We have previously purified a cellular thyroid hormone binding protein (p58) from a human carcinoma cell line [Kitagawa, S., Obata, T., Hasumura, S., Pastan, I., & Cheng, S.-y. (1987) J. Biol. Chem. 262, 3903-3908]. In the present study, the binding characteristics, the molecular properties, and subcellular localization of p58 were further characterized. Binding of the purified p58 to thyroid hormones was examined. Analysis of binding data indicates that p58 binds to 3,3',5-triiodo-L-thyronine (T3) with a Kd of 24.3 +/- 0.3 nM and n = 0.71. p58 binds to L-thyroxine similarly as to T3. However, D-T3 and reverse-T3 bind to p58 with an affinity 4- and 20-fold less than that of T3, respectively. By use of the purified p58 as an immunogen, two hybridomas, J11 and J12, secreting monoclonal antibodies to p58 were isolated; both antibodies belong to the IgG1K subclass. J12 recognizes p58 from human, monkey, dog, hamster, and rat, but not mouse. J11 exhibits a similar species specificity except that it does not react with p58 from hamster. With these antibodies, p58 was found to be not posttranslationally modified by glycosylation, sulfation, or phosphorylation. It has a cellular degradation rate t1/2 congruent to 2.1 h. Immunocytochemical studies indicate that p58 is located in the nonmembranous cytoplasm (cytosol). These results are consistent with subcellular fractionation studies which show that greater than 95% of J11 and J12 reactivity and T3 binding activity can be found in the 110,000g supernatant.     

烟草抗黑胫病突变体的细胞筛选

经实验我们成功地建立了在细胞水平上筛选烟草抗黑胫病突变体的筛选体系。该体系的主要内容为:γ-射线500—2000拉德诱变高度感病品种的花药后用50—80％的黑胫病菌粗毒素为选择压力,筛选出抗毒素花粉植株,用离体叶片法测定选出抗病植株,再从后代鉴定中选出抗病性能够稳定遗传的突变系。γ-射线及高浓度毒素处理均能得到抗病植株。选自感病品种的花粉植株中约有9—50％是真正抗病的。这些抗病植株中有一部分的抗病性能够稳定遗传。用该法已从感病优质品种小黄金1025及乔庄黑苗中选出6个突变系。并自N.C.628(抗)×小黄金1025(感)及N.C.628(抗)×庆胜2号(感)的F_1花粉植株中选出4个抗病系。所有的抗病系经3—4代后均表现出稳定抗性。其中一个突变体(R400)的抗性似由不完全显性多基因控制。     

Presuturing--a new technique for closing large skin defects: clinical and experimental studies

We have developed a new technique termed presuturing for aiding in the closure of large skin defects which may have otherwise required a skin graft or flap. This technique is based on biomechanical properties of skin (creep, stress relaxation) which allow skin to stretch beyond its inherent extensibility. Presuturing is performed under local anesthesia and consists of plicating intact skin over the area of planned excision the night prior to operation. Experimental studies in a pig model showed the decrease in force required to close a standard-sized wound to be 40.1 percent less than control (p less than 0.001). Fourteen patients who underwent wide excision of skin lesions had their wounds presutured. All but one wound could be closed primarily without undermining. Presuturing seems to be an easy and clinically useful technique in aiding the primary closure of large defects.     

The genomic relationship between cultivated sorghum [Sorghum bicolor (L.) Moench] and Johnsongrass [S. halepense (L.) Pers.]: a re-evaluation

Summary The genomic relationship between cultivated sorghum [Sorghum bicolar (L.) Moench, race bicolor, De Wet, 2n=20] and Johnsongrass [S. halepense (L.) Pers., 2n=40] has been a subject of extensive studies. Nevertheless, there is no general consensus concerning the ploidy level and the number of genomes present in the two species. This research tested the validity of four major genomic models that have been proposed previously for the two species by studying chromosome behaviors in the parental species, 30-chromosome hybrids [sorghum, (2n=20) x Johnsongrass, (2n=40)], 40-chromosome hybrids [sorghum, (2n=40) x Johnsongrass, (2n=40)] and 60-chromosome amphiploids. Chromosome pairings of amphiploids are reported for the first time. Chromosomes of cultivated sorghums paired exclusively as 10 bivalents, whereas Johnsongrass had a maximum configuration of 5 ring quadrivalents with occasional hexavalents and octovalents. In contrast, 40-chromosome cultivated sorghum had up to 9 ring quadrivalents and 1 hexavalent. Pairing in the 30-chromosome hybrids showed a maximum of 10 trivalents, and that in the 40-chromosome hybrids exhibited 8 quadrivalents, 5 of which were rings, together with a few hexavalents. Amphiploid plants showed up to 3 ring hexavalents, 1 chain hexavalent and a chain of 12 chromosomes. The data suggest that cultivated sorghum is a tetraploid species with the genomic formula AAB1B1, and Johnsongrass is a segmental auto-allo-octoploid, AAAA B1B1B2B2. The model is further substantiated by chromosome pairing in amphiploid plants whose proposed genomic formula is AAAAAA B1B1B1B1 B2B2.Contribution no. 87-391-J from the Kansas Agriculatural Experiment Station     

Targeting of Sp1 to a non-Sp1 site in the human neurofilament (H) promoter via an intermediary DNA-binding protein.

The human neurofilament (H) promoter contains multiple binding sites for nuclear proteins including a Proximal (Prox) site centered around the sequence GGTTGGACC and an adjacent pyrimidine (Pyr) tract site centered around the sequence CCCTCCTCCCC. Surprisingly binding to a probe containing the Prox/Pyr region of the NF(H) promoter was competed in gel shifts by an oligonucleotide containing only an Sp1 binding site (GGGGCGGGG). Supershift assays with a polyclonal anti-Sp1 antisera confirmed that Sp1 was part of the complex formed with the Prox/Pyr probe. However neither bacterially expressed Sp1 516C or vaccinia virus expressed full-length Sp1 778C bound to the Prox or Pyr sequences in DNase I footprints or gel shift assays. Gel shift competitions and supershift assays with probes containing either Prox or Pyr tract sites alone demonstrated targeting of Sp1 to the Prox binding site and identified a non-Sp1 containing complex which contains a Prox binding protein. Adding exogenous Sp1 to a HeLa nuclear extract enhanced the Sp1-containing complex but had no effect on the Prox complex. These studies show that Sp1 can be targeted to a non-Sp1 site in the human NF(H) promoter through protein/protein interactions with a distinct sequence specific DNA-binding protein.     

头端延髓腹外侧区注射5—羟色胺对应激性高血粘度...

Experiments were carried out on 62 wistar rats. The hyperviscosity and elevation of blood pressure were induced by hanging and restraining the rats with their four limbs tied on a frame. It was found that microinjection of 5-HT (25 micrograms/10 microliters) into the 4th ventricle of the brain or bilateral microinjection of 5-HT (4 micrograms/0.5 microliters/site) into rostral ventrolateral medulla (rVLM) reduced stress-induced hyperviscosity (p < 0.01) and elevation of blood pressure (p < 0.01). The effect of 5-HT injected into the 4th ventricle or rVLM was blocked by bilateral microinjection of cinanserine (4 micrograms/0.5 microliter/site) into rVLM. These results suggest that microinjection of 5-HT into 4th ventricle and rVLM could reduce stress-induced hyperviscosity and elevation of blood pressure and these effects were probably mediated via 5-HT receptors in the rVLM.     

Pseudorabies virus gIII and bovine herpesvirus 1 gIII share complementary functions.

The gIII glycoproteins of bovine herpesvirus 1 (BHV-1) and of pseudorabies virus (PRV) are structurally homologous. Both proteins also play preeminent roles in mediating virus attachment to permissive cells. To directly compare the functional relation between these glycoproteins, we constructed a recombinant BHV-1 in which the BHV-1 gIII coding sequence was replaced by the PRV gene homolog. The resultant recombinant virus efficiently expressed PRV gIII and then incorporated it into its envelope. The levels of PRV gIII expression and incorporation were equivalent to those achieved by the wild-type virus for BHV-1 gIII. The recombinant virus was fully susceptible to neutralization by anti-PRV gIII neutralizing antibody. In addition, the virus attachment and penetration functions, as well as the virus replication efficiency, which were lost by deleting the BHV-1 gIII gene, were restored by expressing the PRV gIII homolog in its place. These results demonstrated that PRV gIII and BHV-1 gIII share complementary functions.     

Oxidation of dimethyl sulfide byPseudomonas acidovorans DMR-11 isolated from peat biofilter

Summary Pseudomonas acidovorans DMR-11, capable of oxidizing dimethyl sulfide (DMS), was isolated from peat biofilter. DMS as a sole carbon or energy source was not degraded, but it was co-degraded in the medium containing organic carbon sources. The removal rate of DMS in heat-treated glucose medium was 1.12×10^–17 mole/h cell at 30 °C. Dimethyl sulfoxide (DMSO) was the only product of DMS oxidation and was formed stoichiometrically. DMS was reversibly evolved in excess of DMSO. The cell free extract of strain DMR-11 oxidized DMS in presence of NADPH.