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81.
Differential regulation of the chick dorsal thoracic dermal progenitors from the medial dermomyotome
Olivera-Martinez I Missier S Fraboulet S Thélu J Dhouailly D 《Development (Cambridge, England)》2002,129(20):4763-4772
The chick dorsal feather-forming dermis originates from the dorsomedial somite and its formation depends primarily on Wnt1 from the dorsal neural tube. We investigate further the origin and specification of dermal progenitors from the medial dermomyotome. This comprises two distinct domains: the dorsomedial lip and a more central region (or intervening zone) that derives from it. We confirm that Wnt1 induces Wnt11 expression in the dorsomedial lip as previously shown, and show using DiI injections that some of these cells, which continue to express Wnt11 migrate under the ectoderm, towards the midline, to form most of the dorsal dermis. Transplantation of left somites to the right side to reverse the mediolateral axis confirms this finding and moreover suggests the presence of an attractive or permissive environment produced by the midline tissues or/and a repellent or inadequate environment by the lateral tissues. By contrast, the dorsolateral dermal cells just delaminate from the surface of the intervening space, which expresses En1. Excision of the axial organs or the ectoderm, and grafting of Wnt1-secreting cells, shows that, although the two populations of dermal progenitors both requires Wnt1 for their survival, the signalling required for their specification differs. Indeed Wnt11 expression relies on dorsal neural tube-derived Wnt1, while En1 expression depends on the presence of the ectoderm. The dorsal feather-forming dermal progenitors thus appear to be differentially regulated by dorsal signals from the neural tube and the ectoderm, and derive directly and indirectly from the dorsomedial lip. As these two dermomyotomal populations are well known to also give rise to epaxial muscles, an isolated domain of the dermomyotome that contains only dermal precursors does not exist and none of the dermomyotomal domains can be considered uniquely as a dermatome. 相似文献
82.
In this study, glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP+ oxidoreductase, EC 1.1.1.49; G6PD) was purified from parsley (Petroselinum hortense) leaves, and analysis of the kinetic behavior and some properties of the enzyme were investigated. The purification consisted of three steps: preparation of homogenate, ammonium sulfate fractionation, and DEAE-Sephadex A50 ion exchange chromatography. The enzyme was obtained with a yield of 8.79% and had a specific activity of 2.146 U (mg protein)(-1). The overall purification was about 58-fold. Temperature of +4 degrees C was maintained during the purification process. Enzyme activity was spectrophotometrically measured according to the Beutler method, at 340 nm. In order to control the purification of enzyme, SDS-polyacrylamide gel electrophoresis was carried out in 4% and 10% acrylamide for stacking and running gel, respectively. SDS-polyacrylamide gel electrophoresis showed a single band for enzyme. The molecular weight was found to be 77.6 kDa by Sephadex G-150 gel filtration chromatography. A protein band corresponding to a molecular weight of 79.3 kDa was obtained on SDS-polyacrylamide gel electrophoresis. For the enzymes, the stable pH, optimum pH, and optimum temperature were found to be 6.0, 8.0, and 60 degrees C, respectively. Moreover, KM and Vmax values for NADP+ and G6-P at optimum pH and 25 degrees C were determined by means of Lineweaver-Burk graphs. Additionally, effects of streptomycin sulfate and tetracycline antibiotics were investigated for the enzyme activity of glucose-6-phosphate dehydrogenase in vitro. 相似文献
83.
BACKGROUND: Tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta are pro-inflammatory cytokines, causing myocardial dysfunction and a negative inotropic effect. The drugs used to treat heart failure affect the production of cytokines. Digoxin, on which this study was focused, is one of the drugs for the treatment of heart failure. AIM: The present study was designed to examine the early effects of high doses of digoxin on the production of cytokines in healthy dogs. METHODS: Digoxin was given parenterally to dogs at 0.15 mg/kg. IL-1beta and TNF-alpha production and levels of digoxin in the serum were measured 0, 12, 24, 48, and 72 h following administration of digoxin. RESULTS: As the levels of serum digoxin taken at 12, 24, 48, and 72 h of administration were considered significantly high compared with preceding values (p < 0.001), no notable change in serum IL-1beta and TNF-alpha levels was observed. CONCLUSIONS: These results suggest that high doses of digoxin do not cause a significant cytokine production in heart muscle in the early phase. 相似文献
84.
Işcan M Ada AO Coban T Kapucuoğlu N Aydin A Isimer A 《Biological trace element research》2002,89(2):177-190
When male rats were given a single dose of cadmium (Cd) (3.58 mg CdCl2·H2O/kg, ip) 72 hr prior to sacrifice, the testicular 7-ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) activities toward the substrates 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB),
ethacrynic acid (EAA), 1,2-epoxy-3-(p-nitrophenoxy)-propane (EPNP), and cumene hydroperoxide (CHPx) decreased significantly as compared to controls. Cd also inhibited
reduced glutathione (GSH) level while increasing the lipid peroxidation (LP) level significantly. When the animals were given
a single dose of nickel (Ni) (59.5 mg NiCl2·6H2O/kg, ip) 16 hr prior to sacrifice, significant decreases were observed in EROD and GST activities toward CDNB, EAA, EPNP,
and CHPx, and GSH level. No significant alterations were noted in DCNB GST activity and LP level by Ni. For the combined treatment,
rats received the single dose of Ni 56 hr after the single dose of Cd and were killed 16 hr later. In these animals, lesser
depressions were observed on EROD activity and LP level than those of Cd alone. The combination of metals significantly inhibited
GST activities and GSH level but not to a greater degree than noted by Cd or Ni alone. Plasma testosterone levels of Cd-,
Ni-, and combination-treated rats decreased significantly compared to controls. The strongest depression was achieved by Cd
alone. Cd, both alone and in combination with Ni, increased the tissue Ni uptake significantly. Ni, however, did not produce
such an effect on the tissue uptake of Cd in either case. Cd treatment caused interstitial edema and coagulation necrosis
in seminiferous tubules and also caused fibrinoidal necrosis in vascular endothelium. Ni treatment did not produce any pathological
testicular alterations compared to controls. Combined treatment produced fewer pathological alterations (i.e., only interstitial
edema) than that of Cd treatment. These results reveal that the combination of Cd and Ni does not have a synergistic effect
on testicular xenobiotic metabolizing enzymes, and in contrast, Ni has an ameliorating effect on pathological disturbances
caused by Cd alone in the rat testis. 相似文献
85.
Food webs in sub-Antarctic lakes: a stable isotope approach 总被引:8,自引:0,他引:8
In order to improve the understanding of food-web interactions in sub-Antarctic freshwater systems, we complemented earlier experimental studies with analyses of differences in stable isotopes (15N and 13C) among organisms in two lakes with contrasting productivity. The distribution of the stable isotopes showed that the small copepod Boeckella michaelseni feeds mainly on pelagic POM (particulate organic material), whereas the larger copepod species B. poppei also feeds on benthic algae. Furthermore, the predatory copepod Parabroteas sarsi seems to mainly feed on B. michaelseni, but also on B. poppei and the benthic cladoceran, Alona weineckii. Moreover, stable-isotope data suggest that the diving beetle, Lancetes angusticollis, is not only feeding on B. poppei as indicated from experimental studies, but also on the benthic cladoceran A. weineckii. Although the food webs of the two lakes are very similar, they show considerable differences in the distribution of stable isotopes. We conclude that monitoring, experiments and stable-isotope analysis in combination give a reasonably clear picture of sub-Antarctic freshwater food webs. 相似文献
86.
Demir Z Kurtay A Sahin U Velidedeoğlu H Celebioğlu S 《Plastic and reconstructive surgery》2003,112(2):423-429
Loss of mustache and beard in the adult male caused by severe burn, trauma, or tumor resection may cause cosmetic and psychological problems for these patients. Reconstruction of the elements of the face presents difficult and often daunting problems for plastic surgeons. The tissue that will be used for this purpose should have the same characteristics as the facial area, consisting of thin, pliable, hair-bearing tissue with a good color match. There is a very limited amount of donor area that has these characteristics. A hair-bearing submental island flap was used successfully for mustache and beard reconstruction in 11 male patients during the last 5 years. The scar was on the mentum in four cases, right cheek in two cases, right half of the upper lip in two cases, left cheek in one case, left half of the upper lip in one case, and both sides of the upper lip in one case. The submental island flap is supplied by the submental artery, a branch of the facial artery. The maximum flap size was 13 x 6 cm and the minimum size was 6 x 3 cm (average, 10 x 4 cm) in this series. Direct closure was achieved at all donor sites. Patients were followed up for 6 months to 5 years. No major complication was noted other than one case of temporary palsy of the marginal mandibular branch of the facial nerve. The mean postoperative stay was 7 days. Color and texture match were good. Hair growth on the flap was normal, and characteristics of the hair were the same as the intact side of the face in all patients. The submental island flap is safe, rapid, and simple to raise and leaves a well-hidden donor-site scar. The authors believe that the submental artery island flap surpasses the other flaps in reconstruction of the mustache and beard in male patients. Application of the technique and results are discussed in this article. 相似文献
87.
88.
The simple and effective choice for treatment of chronic calcaneal osteomyelitis: neurocutaneous flaps 总被引:9,自引:0,他引:9
Yildirim S Gideroğlu K Aköz T 《Plastic and reconstructive surgery》2003,111(2):753-60; discussion 761-2
The authors describe their experience with the use of distally based saphenous and sural neurofasciocutaneous flaps for the treatment of calcaneal osteomyelitis in nine cases. Aggressive débridement of all nonviable and poorly vascularized tissue and coverage with a distally based neurofasciocutaneous flap were coupled with a thorough antibiotic course in all cases. The deepithelized peripheral parts of all flaps were buried in the bone cavities after bone débridement. Follow-up periods ranged from 15 to 27 months. All flaps survived completely. All of the wounds except one healed completely. These flaps have adequate blood flow for the management of chronic bone infections. They also have many advantages, such as easy quick elevation, short operative time, and acceptable donor-site morbidity. Moreover, patients treated with neurocutaneous flaps do not require debulking procedures or special shoes. Reconstruction with neurocutaneous flaps after radical débridement is a versatile alternative to the use of local or distant muscle flaps and calcanectomy procedures for patients with osteomyelitis of the os calcis. 相似文献
89.
Reconstruction of the weight-bearing surface of the foot with nonneurosensory free flaps 总被引:3,自引:0,他引:3
Sönmez A Bayramiçli M Sönmez B Numanoğlu A 《Plastic and reconstructive surgery》2003,111(7):2230-2236
Neurotized fasciocutaneous flaps and split-skin grafted muscle flaps are the most frequently used free flap alternatives for the reconstruction of weight-bearing surfaces of the foot. An objective comparison of the innate characteristics of these two flap types, with respect to long-term stability, has not been possible because sensory reinnervation in the fasciocutaneous flaps has been a confounding factor. This study compares nonsensate fasciocutaneous flaps (n = 9) with nonsensate split-skin grafted muscle flaps (n = 11), with mean follow-up periods of 34.3 and 31.3 months, respectively. Patients completed a form that included questions regarding degree of pain at the operative site, presence of ulcers, ability to wear normal shoes, employment status, and time spent standing on foot. Touch and deep sensation were evaluated with Semmes-Weinstein and vibration tests, respectively. Significantly less pain and less ulceration (p < 0.05) were observed in the fasciocutaneous group. Semmes-Weinstein monofilament tests revealed poorer results with split-skin grafted muscle flaps, compared with fasciocutaneous flaps. These results indicate that even if the sensory protection of fasciocutaneous flaps is not considered, these flaps have superior properties, compared with split-skin grafted muscle flaps. 相似文献
90.