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1.
We report the identification of a TaqI dimorphic site in the first intron of a human phospholipase A2 gene that has been localized on chromosome 12. This single two-allele polymorphism was detected by DNA blot hybridization using a full-length, 584 bp human phospholipase A2 cDNA isolated from a human lung gt10 cDNA library. Fragment lengths were detected at either 1.3 kb or 2.2 kb. The PIC value of this dimorphism was 0.369 in a random population of 353 Caucasians. 相似文献
2.
Mal de Meleda (MDM) caused by mutations in the gene for SLURP-1 in patients from Germany,Turkey, Palestine,and the United Arab Emirates 总被引:7,自引:0,他引:7
Eckl KM Stevens HP Lestringant GG Westenberger-Treumann M Traupe H Hinz B Frossard PM Stadler R Leigh IM Nürnberg P Reis A Hennies HC 《Human genetics》2003,112(1):50-56
Mal de Meleda (MDM) or keratosis palmoplantaris transgrediens of Siemens is an autosomal recessive skin disorder characterized by diffuse palmoplantar keratoderma (PPK) and transgressive keratosis with an onset in early infancy. There is no associated involvement of other organs; however, a spectrum of clinical presentations with optional and variable features has been described. Mutations in the ARS (component B)-81/s gene ( LY6LS) on chromosome 8q24-qter, which encodes SLURP-1, have recently been identified in patients with MDM. Here, we have analyzed four MDM families for mutations in SLURP-1. In a large Palestinian pedigree with multiple consanguinity, patients are homozygous for a new mutation that substitutes an arginine for a conserved glycine residue at position 86. A different mutation in Turkish patients results in the same amino acid exchange. Some remarkable similarities are seen in the clinical picture of patients from both families. Patients of an Emirati Bedouin family have a homozygous alteration of the translation initiation codon. In a German family with no known consanguinity, we have shown pseudodominant inheritance. Three affected children and their affected mother are homozygous for the missense mutation W15R. Our findings indicate that the MDM type of transgressive PPK is caused by SLURP-1 mutations in patients from various origins and demonstrate allelic heterogeneity for mutations in SLURP-1. 相似文献
3.
啤酒多倍体酵母菌原生质体已成功地与单倍体原生质体进行融合。经细胞壁再生后,稳定的融合重组体被分离出来。这些融合体的基因分析表明,融合体中含有双亲的基因型。孢子形成良好,且每个子囊中含有四个孢子,每个孢子确实是二倍体。这样原生质体融合就提供了一个对啤酒酿造酵母进行遗传分析的方法。但是如果没有一个方便的杂交技术,这个方法将是很困难的。 相似文献
4.
The pericentriolar material in Chinese hamster ovary cells nucleates microtubule formation 总被引:10,自引:38,他引:10
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The structure and function of the centrosomes from Chinese hamster ovary (CHO) cells were investigated by electron microscopy of negatively stained wholemount preparations of cell lysates. Cells were trypsinized from culture dishes, lysed with Triton X-100, sedimented onto ionized, carbon-coated grids, and negatively stained with phosphotungstate. The centrosomes from both interphase and dividing cells consisted of pairs of centrioles, a fibrous pericentriolar material, and a group of virus-like particles which were characteristic of the CHO cells and which served as markers for the pericentriolar material. Interphase centrosomes anchored up to two dozen microtubules when cells were lysed under conditions which preserved native microtubules. When Colcemid-blocked mitotic cells, initially devoid of microtubules, were allowed to recover for 10 min, microtubules formed at the pericentriolar material, but not at the centrioles. When lysates of Colcemid-blocked cells were incubated in vitro with micotubule protein purified from porcine brain tissue, up to 250 microtubules assembled at the centrosomes, similar to the number of microtubules that would normally form at the centrosome during cell division. A few microtubules could also be assembled in vitro onto the ends of isolated centrioles from which the pericentriolar material had been removed, forming characteristic axoneme- like bundles. In addition, microtubules; were assembled onto fragments of densely staining, fibrous material which was tentatively identified as periocentriolar material by its association of CHO can initiate and anchor microtubules both in vivo and in vitro. 相似文献
5.
Decreased gene expression from T7 promoters may be due to impaired production of active T7 RNA polymerase 总被引:1,自引:0,他引:1
Background
Protein expression vectors that utilize the bacteriophage T7 polymerase/promoter system are capable of very high levels of protein production. Frequently, however, expression from these vectors does not reliably achieve optimal levels of protein production. Strategies have been proposed previously that successfully maintain high expression levels, however we sought to determine the cause of induction failure. 相似文献6.
Background
Many musculoskeltal injuries in the workplace have been attributed to the repetitive loading of muscle and soft tissues. It is not disputed that muscular fatigue is a risk factor for musculoskeltal injury, however the disparity between gender with respect to muscular fatigability and rate of recovery is not well understood. Current health and safety guidelines do not account for sex differences in fatiguability and may be predisposing one gender to greater risk. The purpose of this study was to quantify the sex differences in fatigue development and recovery rate of lower and upper body musculature after repeated bouts of sustained isometric contractions.Methods
Twenty-seven healthy males (n = 12) and females (n = 15) underwent bilateral localized fatigue of either the knee extensors (male: n = 8; female: n = 8), elbow flexors (male: n = 8; female: n = 10), or both muscle groups. The fatigue protocol consisted of ten 30-second sub-maximal isometric contractions. The changes in maximum voluntary contraction (MVC), electrically evoked twitches, and motor unit activation (MUA) were assessed along with the ability to control the sustained contractions (SLP) during the fatigue protocol using a mixed four-factor repeated measures ANOVA (gender × side × muscle × time) design with significance set at p < 0.05.Results
There was a significant loss of MVC, MUA, and evoked twitch amplitude from pre- to post-fatigue in both the arms and legs. Males had greater relative loss of isometric force, a higher rate of fatigue development, and were less capable of maintaining the fatiguing contractions in the legs when compared to the females.Conclusion
The nature of the induced fatigue was a combination of central and peripheral fatigue that did not fully recover over a 45-minute period. The results appear to reflect sex differences that are peripheral, and partially support the muscle mass hypothesis for explaining differences in muscular fatigue.7.
Melissa Baraket Brian GG Oliver Janette K Burgess Sam Lim Gregory G King Judith L Black 《Respiratory research》2012,13(1):11
Background
While most of the clinical benefits of inhaled corticosteroid (ICS) therapy may occur at low doses, results of dose-ranging studies are inconsistent. Although symptom/lung function response to low and high dose ICS medication is comparable, it is uncertain whether low dose ICSs are as effective as high dose in the treatment of inflammation and remodeling.Methods
22 mild or moderate asthmatic adult subjects (corticosteroid free for > 2 months) participated in a randomized, parallel group study to compare effects of fluticasone propionate (FP) 200 mcg/day and 1000 mcg/day. Alveolar macrophage (AM)-derived cytokines and basement membrane thickness (BMT) were measured at baseline and after 7 weeks treatment while symptoms, spirometry, exhaled nitric oxide (eNO) and airway hyperresponsiveness (AHR) to mannitol at baseline and 6 weeks.Results
FP improved spirometry, eNO, symptoms and AHR with no difference between low and high dose FP. Both high and low dose FP reduced GM-CSF, TNF-alpha and IL-1ra, with no change in BMT and with no differences between low and high dose FP.Conclusions
200 μg/day of FP was as effective as 1000 μg/day in improving asthma control, airway inflammation, lung function and AHR in adults in the short term. Future studies should examine potential differential effects between low and high dose combination therapy (ICS/long acting beta agonist) on inflammation and airway remodeling over longer treatment periods. 相似文献8.
Catch per unit effort (CPUE), length, weight and maturity data for Clarias gariepinus were collected during monthly gillnet surveys in the upper Okavango Delta between 2001 and 2009 to investigate their relationship with the annual flood-pulse. CPUE, condition factor (K) and the proportion of ripe-running fish (PRR) in the population followed a unimodal annual cycle that could be modelled using water temperature and flood-pulse hydrology. Increased CPUE during declining water levels was most likely a result of feeding migrations and aggregation behaviour. The observed increase in K during low floods in October and November preceded the increase in PRR, which increased mainly with increasing temperature but appeared less dependent on flow. This study provided quantitative evidence that the biology of fish in the Okavango Delta is mainly dependent on the annual flood regime and, therefore, that conservation efforts should be focused on maintaining natural flow patterns in the face of climate change and potential water extraction schemes upstream. 相似文献
9.
10.
Effects of EDTA treatment upon the protein subunit composition and mechanical properties of mammalian single skeletal muscle fibers 总被引:9,自引:0,他引:9
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Considerable interest has been focused on the role of myosin light chain LC(2) in the contraction of vertebrate striated muscle. A study was undertaken to further our investigations (Moss, R.L., G.G. Giulian, and M.L. Greaser, 1981, J. Biol. Chem., 257:8588-8591) of the effects of LC(2) removal upon contraction in skinned fibers from rabbit psoas muscles. Isometric tension and maximum velocity of shortening, V(max), were measured in fiber segments prior to LC(2) removal. The segments were then bathed at 30 degrees C for up to 240 min in a buffer solution containing 20 mM EDTA in order to extract up to 60 percent of the LC(2). Troponin C (TnC) was also partially removed by this procedure. Mechanical measurements were done following the EDTA extraction and the readditions of first TnC and then LC(2) to the segments. The protein subunit compositions of the same fiber segments were determined following each of these procedures by SDS PAGE of small pieces of the fiber. V(max) was found to decrease as the LC(2) content of the fiber segments was reduced by increasing the duration of extraction. EDTA treatment also resulted in substantial reductions in tension due mainly to the loss of TnC, though smaller reductions due to the extraction of LC(2) were also observed. Reversal of the order of recombination of LC(2) and TnC indicated that the reduction in V(max) following EDTA treatment was a specific effect of LC(2) removal. These results strongly suggest that LC(2) may have roles in determining the kinetics and extent of interaction between myosin and actin. 相似文献