Effect of Hypoxia on Branching Characteristics and Cell Subpopulations during Kidney Organ Culture.

During early developmental stages, embryonic kidneys are not fully vascularized and are potentially exposed to hypoxic conditions, which is known to influence cell proliferation and survival, ureteric bud branching, and vascularization of the developing kidney. To optimize the culture conditions of in vitro cultured kidneys and gain further insight into the effect of hypoxia on kidney development, we exposed mouse embryonic kidneys isolated at E11.5, E12.5, and E13.5 to hypoxic and normal culture conditions and compared ureteric bud branching patterns, the growth of the progenitor subpopulation hoxb7+, and the expression patterns of progenitor and differentiation markers. Branching patterns were quantified using whole organ confocal imaging and gradient-vector-based analysis. In our model, hypoxia causes an earlier expression of UB tip cell markers, and a delay in stalk cell marker gene expression. The metanephric mesenchyme (MM) exhibited a later expression of differentiation marker FGF8, marking a delay in nephron formation. Hypoxia further delayed the expression of stroma cell progenitor markers, a delay in cortical differentiation markers, as well as an earlier expression of medullary and ureteral differentiation markers. We conclude that standard conditions do not apply universally and that tissue engineering strategies need to optimize suitable culture conditions for each application. We also conclude that adapting culture conditions to specific aspects of organ development in tissue engineering can help to improve individual stages of tissue generation.

Systematic review and meta-analysis of the effects of acupoint stimulation on smoking cessation.

Smoking represents a serious worldwide public health problem because of its close association with the development of chronic disease and cancer. Acupoint stimulation has been used as treatment mode for smoking cessation but its efficacy remains controversial. This systematic review and meta-analysis aimed to determine the effects of acupoint stimulation on smoking cessation rate and daily cigarette consumption. Electronic literature searches in eight electronic databases up to March 2011 were performed to identify acupoint stimulation for smoking cessation. The outcomes assessed were smoking cessation rate and cigarette consumption. We assessed abstinence from smoking at the earliest and last measured time points, and at the 3- and 6-month follow-ups. Meta-analysis was performed using CMA software. A total of 20 RCTs were included in the meta-analysis. A significant effect of acupoint stimulation was found in smoking cessation rates and cigarette consumption at immediate, 3- and 6-month follow-ups, with effect sizes 1.24 (95%CI = 1.07 ~ 1.43, p = 0.003), -2.49 (95%CI = -4.65 ~ -0.34, p = 0.02), 1.70 (95%CI = 1.17 ~ 2.46, p = 0.01), and 1.79 (95%CI = 1.13 ~ 2.82, p = 0.01), respectively. Multi-modality treatments, especially acupuncture combined with smoking cessation education or other interventions, can help smokers to eschew smoking during treatment, and to avoid relapse after treatment.