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排序方式: 共有206条查询结果,搜索用时 15 毫秒
1.
Shimp KL Bhatnagar KP Bonar CJ Smith TD 《The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology》2003,274(1):862-869
Ecological explanations have been put forward to account for the precocious or delayed development of patency in ducts leading to the vomeronasal organ (VNO) in certain mammals. Perinatal function may be related, in part, to the patency or fusion of the vomeronasal and nasopalatine (NPD) ducts. However, few studies have focused on NPD development in primates, which generally have a prolonged period of dependence during infancy. In this study we examined 24 prenatal primates and 13 neonatal primates, and a comparative sample of fetal mice and insectivores. In embryonic and early fetal Microcebus murinus, the NPD was completely fused, whereas in fetuses of later stages the duct was partially fused or completely patent. M. myoxinus of all stages demonstrated some degree of NPD fusion. In all other prenatal primates, the NPD was fused to some extent. Four prenatal insectivores (Tenrec ecaudatus) showed some degree of NPD fusion. In Mus musculus at 19 days gestation, the NPD was patent, although the anatomically separate VNO duct was fused. T. ecaudatus and most of the neonatal primates revealed complete NPD patency. An exception was Saguinus geoffroyi, which exhibited fusion of the NPD near the VNO opening. These observations may relate to differences in perinatal VNO function. The differences noted in our study suggest that M. murinus and M. myoxinus may differ in perinatal VNO functionality and perhaps in related behavior. Observations of neonatal primates suggest that NPD patency may be relatively common at birth and could serve other purposes in addition to being an access route for VNO stimuli. 相似文献
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The terms "microsmatic" and "macrosmatic" refer to species with lesser or greater levels, respectively, of olfactory function. Historically, primates are considered microsmats (olfactory sense reduced) with a concomitant increased emphasis on vision. The olfactory bulbs (forebrain centers that receive peripheral olfactory input) are proportionately smaller in primates compared to most other mammals. Similarly, the regions of the nasal cavity that are covered with olfactory epithelium (containing receptor cells) have proportionately less surface area in primates than other mammals. Thus, the generalization that primates are microsmatic is most frequently stated in terms of the proportional rather than absolute size of olfactory structures. Yet the importance of scaling to body size is unclear in regard to the chemical senses such as the olfactory or vomeronasal systems-do chemosensory structures such as olfactory bulbs and olfactory epithelium exhibit the same neural relationship to body mass that is seen for neural tissues that supply innervation to musculature or the skin? Previous studies examining neuronal density, volume, and/or surface area of the olfactory epithelium illustrate that different conclusions may be supported based on the parameter used. Plots of olfactory bulb volume versus body mass that generated for large-scale taxonomic studies or growth studies benefit from body mass (or total brain volume) with a comparative perspective. However, our examination of proportional versus absolute measurements implies that in comparisons within taxa, body size adjustments needlessly distort the data. As a final consideration, another embryonic derivative of the nasal placode, the vomeronasal organ, may warrant consideration regarding a definition of microsomia versus macrosomia. 相似文献
4.
Kunwar Bhatia Kevin P Gibbin Thomas P Nikolopoulos Gerard M O'Donoghue 《Otology & neurotology》2004,25(5):730-739
OBJECTIVE: To report the short- and long-term complications encountered in a large number of consecutive children undergoing implantation in a single center. The current study also describes the management and sequelae of each complication. STUDY DESIGN: Prospective study assessing the surgical findings and complications of deaf children undergoing implantation. SETTING: Pediatric tertiary referral center for cochlear implantation. PATIENTS: The present study includes 300 consecutive children undergoing implantation, with a mean age at implantation of 5.1 years, ranging from 1.3 to 16.9 years. Of these children, 196 (65%) had congenital deafness of unknown cause. The commonest known cause was meningitis (73 of 300 [24%]) followed by congenital cytomegalovirus infection (17 of 300 [6%]). Children have been followed up regularly after implantation, typically at yearly intervals after the first year. The mean duration of follow-up at the time of the study was 4 years (range, 0.1-14 yr). RESULTS: There were no major perioperative (within 1 d after surgery) or major early postoperative (within 1 wk after surgery) complications. In the same periods, there were 19 and 15 minor complications, respectively. These complications (e.g., eardrum perforation, hematoma, flap swelling, wound infection, temporary facial weakness) settled with conservative treatment or minor intervention. With regard to the late surgical complications (>1 wk after surgery), there were 7 major (e.g., severe flap infection requiring explantation, cholesteatoma, persistent eardrum perforation) and 14 minor complications (e.g., mild flap infection, flap swelling, hematoma). A number of complications were encountered even 14 years after the original operation, and some of them needed repeated interventions, highlighting the importance of long-term follow-up. However, most of the complications occurred very close to the surgical procedure (<1 yr). CONCLUSION: An overall rate of 2.3% for major surgical complications and an overall rate of 16% for minor surgical complications suggest that cochlear implantation is a relatively safe surgical operation in experienced centers. Most surgical complications are minor and can be managed with conservative treatment or minor surgical intervention. However, meticulous attention to surgical detail, especially handling soft tissues and leaving the posterior canal wall intact, and long-term follow-up are of paramount importance in minimizing the incidence of surgical complications. 相似文献
5.
IL-17 has a role in inflammation in RA, and its levels in joints correlate with disease severity. Multiple RCTs have been performed to study effects of anti-IL-17 agents. The objective of this study was to perform a systematic review and meta-analysis to analyze the efficacy and safety of anti-IL-17 agents in the management of RA. This work is based on a systematic review of studies retrieved by a sensitive search strategy in PubMed, EMBASE and Cochrane CENTRAL from inception through 9/7/15. Study selection criteria were the following: adult patients (age ≥ 18 years) with RAs, random selection of patients for anti-IL-17 therapy and treatment response compared to placebo. We performed systematic literature review per PRISMA guideline and two investigators independently selected seven randomized clinical trials (RCTs) for meta-analysis. We used random effect model calculating odds ratio (OR) and 95 % confidence interval (CI) to measure the efficacy with ACR20/50/70 responses and the safety with adverse events. Seven studies with total of 1226 patients including 905 in anti-IL-17 group and 321 in placebo were included in the meta-analysis. Anti-IL-17 was effective in achieving ACR20 and ACR50 compared to placebo (OR 2.47, 95 % CI 1.29–4.72, P = 0.006, I 2 77 % and OR 2.94, 95 % CI 1.37–6.28, P = 0.005, I 2 64 %, respectively). Data analysis for ACR70 showed a favorable trend toward anti-IL-17 (OR 2.62, 95 % CI 1–6.89, P = 0.05, I 2 15 %). Subgroup analysis of ACR20 for individual anti-IL-17 agents showed that ixekizumab was more effective than placebo, while secukinumab showed a trend toward achieving the ACR20 response. However, brodalumab was not effective compared to placebo. Safety analysis did not show increased risk of any or serious adverse effects by anti-IL-17 compared to placebo (OR 1.23, 95 % CI 0.94–1.61, P = 0.13, I 2 = 0 % and OR 1.28, 95 % CI 0.57–2.88, P = 0.55, I 2 = 0 %, respectively). This meta-analysis concludes that anti-IL-17 is effective in the treatment of RA without increased risk of any or serious adverse effects; however, the results are limited by significant heterogeneity and small duration of studies. 相似文献
6.
Abigail A. Curtis Timothy D. Smith Kunwar P. Bhatnagar Alexis M. Brown Nancy B. Simmons 《Anatomical record (Hoboken, N.J. : 2007)》2020,303(1):110-128
Horseshoe bats (Family Rhinolophidae) show an impressive array of morphological traits associated with use of high duty cycle echolocation calls that they emit via their nostrils (nasophonation). Delicate maxilloturbinal bones inside the nasal fossa of horseshoe bats have a unique elongated strand-like shape unknown in other mammals. Maxilloturbinal strands also vary considerably in length and cross-sectional shape. In other mammals, maxilloturbinals help direct respired air and prevent respiratory heat and water loss. We investigated whether strand-shaped maxilloturbinals in horseshoe bats perform a similar function to those of other mammals, or whether they were shaped for a role in nasophonation. Using histology, we studied the mucosa of the nasal fossa in Rhinolophus lepidus, which we compared with Hipposideros lankadiva (Hipposideridae) and Megaderma lyra (Megadermatidae). Using micro-CT scans of 30 horseshoe bat species, we quantified maxilloturbinal surface area and skull shape within a phylogenetic context. Histological results showed horseshoe bat maxilloturbinals are covered in a thin, poorly vascularized, sparsely ciliated mucosa poorly suited for preventing respiratory heat and water loss. Maxilloturbinal surface area was correlated with basicranial width, but exceptionally long and dorsoventrally flat maxilloturbinals did not show enhanced surface area for heat and moisture exchange. Skull shape variation appears to be driven by structures linked to nasophonation, including maxilloturbinals. Resting echolocation call frequency better predicted skull shape than did skull size, and was specifically correlated with dimensions of the rostral inflations, palate, and maxilloturbinals. These traits appear to form a morphological complex, indicating a nasophonatory role for the strand-shaped rhinolophid maxilloturbinals. Anat Rec, 2018. © 2018 American Association for Anatomy. 相似文献
7.
K R Olson D Lipke J S Datta Munshi A Moitra T K Ghosh G Kunwar M Ahmad P K Roy O N Singh S S Nasar 《General and comparative endocrinology》1987,68(3):486-491
Angiotensin-converting enzyme (ACE) was measured in tissue homogenates from the African lungfish and six species of air-breathing teleosts (Heteropneustes fossilis, Clarias batrachus, Channa gachua, Anabas testudineus, Notopterus chitala, and Monopterus cuchia) using a standard spectrophotometric assay. In most species, the highest levels of ACE activity were found in the respiratory organs (gills and/or accessory respiratory organs). ACE was also found in heart and kidney tissues from most species and occasionally in liver. Converting enzyme was not found in skin or skeletal muscle from any species and only in blood from H. fossilis and brain from C. batrachus. Captopril, a potent inhibitor of mammalian ACE, inhibited enzymatic activity from all tissues except C. gachua heart and liver and A. testudineus heart. As fish make the transition from aquatic to aerial respiration the gill microcirculation is usually reduced in size and the accessory respiratory organs become elaborated and occupy a more central position in the vascular tree. The presence of ACE in accessory respiratory organs of air-breathing fish appears to greatly enhance the metabolic efficiency of this enzyme on circulating substrates. 相似文献
8.
目的:总结单孔腹腔镜技术在我院泌尿外科应用的初步经验。方法:回顾性分析2011年7月在我院泌尿外科行单孔腹腔镜手术的7例患者的临床资料。结果:采用单孔X-CONE建立操作通道,使用常规及弯曲腹腔镜器械完成7例单孔腹腔镜手术。其中包括肾上腺腺瘤2例,肾囊肿2例,精索静脉曲张2例,乳糜尿1例。3例手术经脐腹腔路径,4例经后腹腔。7例手术均获成功,手术时间27~135min,出血量5~40ml,术后住院时间2~6d。无明显术中和术后并发症。切口愈合良好,瘢痕小。结论:单孔腹腔镜手术对操作技能、解剖认识要求较高,该技术安全可行,具有创伤小,恢复快,切口美观的优点。进一步的临床实践和器械的改进将有助于该技术推广应用。 相似文献
9.
Shailubhai K 《Current opinion in drug discovery & development》2002,5(2):261-268
Uroguanylin, guanylin, lymphoguanylin and bacterial enterotoxin ST are structurally related peptides that activate common guanylate cyclase signaling molecules and, via cyclic GMP (cGMP), regulate water and ion homeostasis in a variety of tissues and organs, including the gastrointestinal (GI) tract, kidneys, lung, prostate, etc. Any disruptions in water and ionic homeostasis due to reduced production of one or more of the guanylin family of peptides can potentially lead to carcinogenic and inflammatory stimuli. Recent findings that expression of uroguanylin and guanylin is dramatically reduced in polyps and colon carcinoma tissues further support the notion that these peptide hormones are important modulators or mediators of signaling pathways leading to the processes involved in carcinogenesis and inflammatory disorders. This review briefly discusses recent research findings suggesting the novel therapeutic applications of agonist peptides of guanylate cyclase-C receptor. 相似文献
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