In vitro low-speed side collisions cause injury to the lower cervical spine but do not damage alar ligaments

Whether injuries to the alar ligaments could be responsible for complaints of patients having whiplash injury in the upper cervical spine is still controversially discussed. It is known that these ligaments protect the upper cervical spine against excessive lateral bending and axial rotation movements. The objective of the present in vitro study was therefore to examine whether the alar ligaments or any other structures of the cervical spine are damaged in side collisions. In a specially designed acceleration apparatus, six human osteoligamentous cervical spine specimens were subjected to incremental 90° side collisions from the right (1 g, 2 g, 3 g, etc.) until structural failure occurred. A damped pivot table accounted for the passive movements of the trunk during collision, and a dummy head (4.5 kg) ensured almost physiological loading of the specimens. For quantification of functional injuries, the three-dimensional flexibility of the specimens was tested in a spine tester before and after each acceleration. In all six specimens, structural failure always occurred in the lower cervical spine and always affected the facet joint capsules and the intervertebral discs. In four specimens, this damage occurred during the 2 g collision, while in the other two it occurred during the 3 g and 4 g collision, respectively. The flexibility mainly increased in the lower cervical spine (especially in lateral bending to both sides) and, to a minor extent, in axial rotation. In vitro low-speed side collisions caused functional and structural injury to discoligamentous structures of the lower cervical spine, but did not damage the alar ligaments. Since the effects of muscle forces were not taken into account, the present in vitro study reflects a worst-case scenario. Injury thresholds should therefore not be transferred to reality.     

Role of CD4+ and CD8+ T cells in murine skin and heart allograft rejection across different antigenic desparities

The factors that influence the relative contribution of the T cell subsets to allograft rejection remain unclear. We compared skin and heart rejection in CD4 Knockout (KO), and CD8 KO mice across full-, minor-, and class II histocompatibility antigen (HA) mismatches. Skin allografts were rejected by either CD4+ or CD8+ T cells alone at any degree of antigenic mismatch. However, either the absence of CD4+ cells or a lesser degree of HA mismatch resulted in prolongation of graft survival. In contrast, fully allogeneic heart grafts were accepted in CD4 KO recipients, and minor HA mismatched heart grafts were accepted by both CD4 KO and CD8 KO mice. Thus, the T cell subsets required for allograft rejection are determined by the immunogenicity of the tissue transplanted. In the absence of CD8+ T cells, perforin and Fas ligand (FasL) but not granzyme B mRNA were detected in rejecting grafts. Thus, granzyme B is a CD8+ cytotoxic T lymphocyte (CTL)-specific effector molecule.     

Formation and differentiation of the avian dermomyotome

During somite maturation, the ventral half of the epithelial somite disintegrates into the mesenchymal sclerotome, whereas the dorsal half forms a transitory epithelial sheet, the dermomyotome, lying in between the sclerotome and the surface ectoderm. The dermomyotome is the source of most of the mesodermal tissues in the body, giving rise to cell types as different as muscle, connective tissue, endothelium, and cartilage. Thus, the dermomyotome is the most important turntable of mesodermal cell fate choice in the vertebrate embryo. Here, we discuss the current knowledge on the formation of the dermomyotome and the mechanisms leading to the development of the various dermomyotomal derivatives, with special emphasis on the development of musculature and dermis.     

可微创拔管的新型肺动脉插管方法的实验研究

目的　创建一种可以在术后微创拔管的新型肺动脉插管方法 ,用于右心辅助循环实验。方法　选用 7只成年犬 ,将 1个特制的可拆卸的人工血管 牛心包管“组件”(简称“组件”)的牛心包与主肺动脉吻合 ,作为肺动脉插管通道 ,组件的人工血管端及连接组件两段管道的连线经肋间小切口引到体外 ,经此途径插肺动脉灌注管到主肺动脉 ,再将组件上预置的打结 牵引线经另一肋间小切口引到体外并收紧 ;经皮切口插引流管到股静脉或颈外静脉建立右心辅助循环。停机后实施微创拔管 ,其关键步骤是依靠一种可经小切口向体内深部打结的简单方法 ,使用扩张管和打结器 ,将预置在“组件”上的滑线打结使牛心包管闭合 ,然后撤出“组件”上的牵引线、连接线和人工血管。结果　经此方法建立起的右心辅助的最大流量为 (6 4± 12 )ml·min-1·kg-1。微创拔管后活体开胸检查证实 ,除第 2例外 ,其他 6例牛心包管上的两组结 (各 8个 )均满意 ,主肺动脉吻合口和牛心包管残端均无出血。第2例第 2组的打结 牵引线被打进第 7个结中因抽不出来而部分残留。结论　该研究建立的这种可以在术后微创拔管的新型插管方法简单方便、安全有效 ,右心辅助的血流动力学效果满意 ,将来可为心外科医生在选择辅助循环时解除后顾之忧。     

Participation in annual skin cancer screening among women seeking routine mammography

BACKGROUND: Early detection of skin cancer is associated with improved prognosis. The American Cancer Society's current skin cancer screening (SCS) recommendation states that adults over the age of 40 should receive an annual skin examination conducted by a health professional. However, little is known about the psychosocial factors related to participation in annual SCS, which remains relatively low among the general public. METHODS: Data were collected from women, aged 50 and older, seeking routine mammography at a large, urban, breast diagnostic facility. RESULTS: A total of 253 eligible women completed the survey. Overall, 20.2% of women reported receiving annual clinical SCS. Physician recommendation, self-efficacy, perceived susceptibility, and age were significantly associated with participation in annual skin screening. CONCLUSIONS: Similar to previously reported findings in the literature, our rates of participation in annual clinical skin screening were lower than reported rates for other types of cancer screening. Among older women, multiple covariates for participation in annual skin cancer screening were determined and may serve to guide future health education interventions to promote screening. Our findings suggest that participation could improve through increasing physician recommendation, screening self-efficacy, and individuals' sense of perceived susceptibility to skin cancer.     

Evidence that arsenite acts as a cocarcinogen in skin cancer

Inorganic arsenic (arsenite and arsenate) in drinking water has been associated with skin cancers in several countries such as Taiwan, Chile, Argentina, Bangladesh, and Mexico. This association has not been established in the United States. In addition, inorganic arsenic alone in drinking water does not cause skin cancers in animals. We recently showed that concentrations as low as 1.25 mg/l sodium arsenite were able to enhance the tumorigenicity of solar UV irradiation in mice. The tumors were almost all squamous cell carcinomas (SCCs). These data suggest that arsenic in drinking water may need a carcinogenic partner, such as sunlight, in the induction of skin cancers. Arsenite may enhance tumorigenicity via effects on DNA repair and DNA damage-induced cell cycle effects, leading to genomic instability. Others have found that dimethlyarsinic acid (DMA), a metabolite of arsenite, can induce bladder cancers at high concentrations in drinking water. In those experiments, skin cancers were not produced. Taken together, these data suggest that arsenite (or possibly an earlier metabolite), and not DMA, is responsible for the skin cancers, but a second genotoxic agent may be a requirement. The differences between the US and the other arsenic-exposed populations with regard to skin cancers might be explained by the lower levels of arsenic in the US, less sun exposure, better nutrition, or perhaps genetic susceptibility differences.     

Effect of skin care with an emollient containing a high water content on mild uremic pruritus

Skin care is very important for preventing uremic pruritus. However, mild uremic pruritus has usually been treated with antihistamine and urea-containing ointments. We therefore examined the effects of an aqueous gel with higher water content. Twenty hemodialysis patients with mild pruritus who were not being treated with any emollient were divided into two groups of 10 each. Patients in one group were treated with an aqueous gel containing 80% water. This emollient was applied twice daily for 2 weeks. No emollient was applied for the next 2 weeks. The other group of patients were not treated with any emollient for the 4 weeks. Visual analog scale scores for itching in the experimental group at week 2 were significantly decreased compared with that at week 0 (3.5 +/- 0.3 vs 0.6 +/- 0.2, P < 0.01). Skin dryness in the experimental group was significantly improved at week 2 compared with that at week 0. The visual analog scale score for itching increased to 1.2 +/- 0.5 and skin dryness reappeared in 40% of patients by week 4, i.e. after the emollient was stopped. There were no significant changes in the control group during the study. It is concluded that the aqueous gel with high water content reduced itching and improved xerosis in patients with mild uremic pruritus. It is reasonable that skin care with an emollient containing a high water content is first started for hemodialysis patients with xerosis, even if they do not feel itching.     

Phospholipid polymer, 2-methacryloyloxyethyl phosphorylcholine and its skin barrier function

The effect of poly[2-methacryloyloxyethyl phosphorylcholine] (pMPC) on the skin permeation property was investigated by performing in vitro skin permeation study of a model drug, nicotinic acid (NA). Effect of pMPC polymer in donor solution on skin permeation rates was evaluated using side-by-side diffusion cells. Also, the structural alterations in the stratum corneum (SC), inter-lamellar bilayer (ILB) and dermis layers in pMPC-treated and -untreated skin sections were investigated with transmission electron microscopy (TEM). The permeation profile of NA without pMPC in donor solution showed biphasic mode: initial 1st phase and 2nd hydration phase. The sudden, more than 10-fold increase in flux from the initial steady state (43.5 microg/cm2/hr) to the 2nd hydration phase (457.3 microg/cm2/h) suggests the disruption of skin barrier function due to extensive hydration. The permeation profile of NA with 3% pMPC in the donor solution showed monophasic pattern: the steady state flux (10.9 microg/cm2/h) without abrupt increase of the flux. The degree of NA permeation rate decreased in a concentration-dependent manner of pMPC. TEM of skin equilibrated with water or 2% pMPC for 12 h showed that corneocytes are still cohesive and epidermis is tightly bound to dermis in 2% pMPC-treated skin, while wider separation between corneocytes and focal dilations in inter-cellular spaces were observed in water-treated skin. This result suggests that pMPC could protect the barrier property of the stratum corneum by preventing the disruption of ILB structure caused by extensive skin hydration during skin permeation study.     

Prenylated flavonoids as tyrosinase inhibitors

In order to find new tyrosinase inhibitors and the effects of prenyl residue on flavonoid molecules, eight prenylated and three synthetic vinylated flavonoids were examined on their inhibitory effect against tyrosinase activity. From the results, kuwanon C, papyriflavonol A, sanggenon D and sophoflavescenol were found to possess the considerable inhibitory activity. Especially, sanggenon D is revealed as a potent inhibitor (IC50 = 7.3 microM), compared to the reference compound, kojic acid (IC50 = 24.8 microM). However, the prenylation with isoprenyl group or the vinylation to flavonoid molecules did not enhance tyrosinase inhibitory activity.