Aural Barotrauma in Submarine Escape: Is Mastoid Pneumatization of Significance?

OBJECTIVE: Submarine escape training is carried out by preselected, healthy young men under strictly controlled conditions regarding exposure to pressure and the rate of pressure change. This provides a unique opportunity to investigate the relations between middle ear characteristics and susceptibility to barotrauma while avoiding possible confounding parameters. We examined a possible association between mastoid pneumatization and middle ear barotrauma (MEB) in submarine escape trainees. STUDY DESIGN: Cross-sectional, parallel-group design. METHODS: Sixty-six subjects aged 19 to 28 participated in the study. The escape simulation included pressurization to 30 or 60 feet followed by a buoyant ascent to the surface. Subjects were evaluated for MEB after each ascent. A Schuller's mastoid radiograph was taken for the evaluation of mastoid pneumatization. RESULTS: Fifteen (23%) of the subjects suffered from MEB, and 6 (40%) of them had bilateral involvement. Repeated impedance audiometry after the completion of a successful ascent revealed a significant increase in middle ear compliance. Schuller's radiographs were obtained from 49 (74%) of the subjects. Of these radiographs, 16 (16%) were of ears that had suffered MEB. Mastoid pneumatization for all ears approached a normal Gaussian distribution, with a mean area of 9.58 cm. The mastoid areas and the proportion of ears with mastoid pneumatization at the extremes of the study population did not differ between barotrauma and no-barotrauma ears. CONCLUSION: In a population with no history of recurrent or chronic otitis media and normal tympanic membrane morphology and compliance, the amount of mastoid pneumatization probably represents merely the normal distribution of variation in organ size and is not related to the ability to equalize pressure in the middle ear.     

Protective effect of beta-glucan against oxidative organ injury in a rat model of sepsis

Sepsis leads to various organ damage and dysfunction. One of the underlying mechanisms is thought to be the oxidative damage due to the generation of free radicals. In this study, we investigated the putative protective role of beta-glucan against sepsis-induced oxidative organ damage. Sepsis was induced by caecal ligation and puncture (CLP) in Wistar albino rats. Sham operated (control) and sepsis groups received saline or beta-glucan (50 mg/kg, po) once daily for 10 days and 30 min prior to and 6 h after the CLP. Sixteen hours after the surgery, rats were decapitated and the biochemical changes were determined in the brain, diaphragm, kidney, heart, liver and lung tissues using malondialdehyde (MDA) content - an index of lipid peroxidation - glutathione (GSH) levels - a key antioxidant - and myeloperoxidase (MPO) activity - an index of neutrophil infiltration. Serum TNF-alpha levels were assessed by RIA method. Tissues were also examined under light microscope to evaluate the degree of sepsis-induced damage. The results demonstrate that sepsis significantly decreased GSH levels and increased the MDA levels and MPO activity (p<0.05-p<0.001) causing oxidative damage. Elevated plasma TNF-alpha levels in septic rats significantly reduced to control levels in beta-glucan treated rats. Since beta-glucan administration reversed these oxidant responses, it seems likely that beta-glucan protects against sepsis-induced oxidative organ injury.     

Neurodevelopmental outcome of children with congenital hypothyroidism diagnosed in a national screening program in Turkey

Objective

To study the factors affecting a neurodevelopmental status of children with congenital hypothyroidism, diagnosed on national screening program.

Methods

The study was performed in the Pediatric Endocrinology Department of Dr. Behcet Uz Children’s Hospital between May 2012 and May 2013. Children with congenital hypothyroidism, aged between 24 and 36 months, diagnosed by national screening program were included in the study group. Healthy subjects at the same age group consisted of the control group. For the neurodevelopmental evaluation, Bayley Scale of Infant Development- II (BSID-II) was used. Factors possibly effective on neurodevelopment were evaluated.

Results

42 patients and 40 healthy children (mean (SD) age, 29.4 (3.7) and 29.2 (3.5), respectively were included in the study. The mean MDI score [92.6 (7.07) vs 97.1 (9.69), P=0.14)] and the mean PDI score [97.8 (15.68) vs 99.1 (10.57), P=0.66)] in the study group and control group were not significantly different. Among the patient, 4.6% and 4.7% children were moderately retarded as per the MDI scores and PPI scores, respectively. The sex, socioeconomic status, birth weight, screening levels of TSH, severity of the congenital hypothyroidism, initiation time and the dosage of thyroid hormone replacement, length of the normalization period of TSH, and adherence to treatment were not found to affect the MDI and PDI scores of the patients.

Conclusion

Some children with congenital hypothyrodism may have mild to moderate neurodevelopmental retardation, despite the early diagnosis and treatment, and thus need to be under regular follow-up for neurodevelopmental status.

     

Eldepryl prevents 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced nigral neuronal apoptosis in mice

Objective To study the apoptotic effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydrop yridine (MPTP) on the nigral dopaminergic neurons of mice and 1-methyl-4-phen ylpyridium ion (MPP(＋)) on pheochromocytoma (PC12) cells, as well as the antagon ism of Eldepryl against MPTP’s apoptotic effect.Methods Three groups of C(57)BL mice were treated with MPTP, Eldepryl plus MPTP and normal saline, respectively, for 7 days before performing TUNEL (terminal deoxyn eucleotidyl transferase-mediated dUTP-x nick end labeling) and FACS (fluoresce nce activated cell sorting) analyses of neuronal apoptosis in the substantia nig ra. The same tests were employed in cell culture to examine apoptosis in PC12 c ells treated with MPP(＋), MPTP or PBS. Results Intraperitoneal administration of MPTP 30 mg/kg could induce nigral apoptos is, and oral use of Eldepryl prior to MPTP treatment could completely prevent the ni gral apoptosis caused by MPTP. MPP(＋), an intermediate metabolite of MPTP, coul d lead to the apoptosis of PC12 cells, whereas MPTP itself had no such effect on PC12 cells. Conclusions The experiment indicated that the neurotoxin, MPTP, might cause the death of nig ral neurons through a mechanism of apoptosis and this effect might be mediated b y its bioactive intermediate metabolite MPP(＋). Eldepryl could protect the neurotoxicity from MPTP.     

外源性骨髓间充质干细胞在糖尿病模型大鼠体内向胰腺迁移并分化为胰岛细胞的趋势

目的:观察尾静脉注射骨髓间充质干细胞在糖尿病模型大鼠体内定向迁移至胰腺组织的规律。方法:实验于2004-08/2006-03在唐山工人医院中心实验室,华北煤炭医学院动物中心完成。实验材料:青年SD大鼠购自华北煤炭医学院动物中心(动物级别:SPF/VAF;许可证号:SCXK2002-0003)。实验方法:①采用密度梯度离心结合贴壁培养方法分离、纯化雄性大鼠骨髓间充质干细胞,并采用免疫组织荧光法鉴定。②将30只雌性大鼠完全随机分为3组:生理盐水组、骨髓间充质干细胞组、糖尿病模型组,每组10只。骨髓间充质干细胞组大鼠经尾静脉注射1×106L-1骨髓间充质干细胞0.2mL;生理盐水组大鼠尾静脉注射0.2mL生理盐水;糖尿病模型组检测大鼠各基础血糖值及体质量,按65mg/kg计算所需链脲佐菌素剂量,将其溶于柠檬酸钠缓冲液中,立即腹腔注射。用血糖仪及血糖试纸监测大鼠血糖,当血糖≥16.7mmol/L且稳定2d后经尾静脉注射1×106L-1骨髓间充质干细胞0.2mL。③应用原位杂交法检测雌性大鼠胰腺组织内Y染色体标志物及放射免疫法测定C-肽值。结果:30只大鼠均进入结果分析。①雌性大鼠腹腔注射链脲佐菌素后血糖检测:注射后2d血糖水平开始迅速升高,4d后血糖值大于16.7mmol/L且稳定在21mmol/L左右,30只大鼠均造模成功。②免疫荧光法检测骨髓间充质干细胞表型:呈抗Laminin染色阴性、抗CD44染色阳性。③放射免疫法检测雌性大鼠血清中C-肽值:与注射前比较,骨髓间充质干细胞组及糖尿病模型组注射骨髓间充质干细胞后,大鼠血清中C-肽值呈明显升高的趋势[注射前:(0.398±0.094),(0.263±0.011)μg/L;注射后:(0.443±0.109),(0.374±0.961)μg/L,P<0.05或P<0.01],生理盐水组无明显变化。④鼠胰腺组织石蜡切片中Y染色体标记物表达:生理盐水组大鼠胰腺组织中未见黄绿荧光Y染色体标记物存在,骨髓间充质干细胞组和糖尿病模型组大鼠胰腺组织中均可见黄绿荧光Y染色体标记物存在,糖尿病模型组大鼠胰腺组织中黄绿荧光强度较大、数量较多。结论:体外分离培养的骨髓间充质干细胞经尾静脉注射后,在糖尿病模型大鼠体内可迁移至胰腺组织中,并具有分化为胰岛素分泌细胞的可能性。     

Silymarin, the antioxidant component of Silybum marianum, prevents sepsis-induced acute lung and brain injury

BACKGROUND: Sepsis is associated with enhanced generation of reactive oxygen species, which leads to multiple organ dysfunctions. Based on the potent antioxidant effects of silymarin, we investigated the putative protective role of silymarin against sepsis-induced oxidative damage in lung and brain tissues. MATERIALS AND METHODS: Sepsis was induced by cecal ligation and perforation (CLP). Sham and CLP groups received either vehicle or silymarin (50 mg/kg, p.o.) or 150 mg/kg i.p. N-acetylcysteine (NAC) for 10 days prior and immediately after the operation. Six hours after the surgery, rats were decapitated and blood was collected for the measurement of proinflammatory cytokines (tumor necrosis factor-alpha, interleukin-1 beta [IL-1 beta], and IL-6) levels, lactate dehydrogenase activity, and total antioxidant capacity. Lung and brain samples were taken for the measurement of malondialdehyde and glutathione levels, myeloperoxidase activity, thromboplastic activity, and also for histological assessment. Formation of reactive oxygen species in tissue samples was monitored by using chemiluminescence technique with luminol and lusigenin probe. RESULTS: Sepsis increased serum TNF-alpha, IL-1 beta, IL-6 levels, and lactate dehydrogenase activity and decreased total antioxidant capacity. On the other hand, tissue glutathione levels were decreased while malondialdehyde levels and myeloperoxidase activity were increased in both the lung and the brain tissues due to CLP. Furthermore, luminol and lucigenin chemiluminescence were significantly increased in the CLP group, indicating the presence of the oxidative damage. Silymarine and NAC treatment reversed these biochemical parameters and preserved tissue morphology as evidenced by histological evaluation. CONCLUSIONS: Silymarin, like NAC, reduced sepsis-induced remote organ injury, at least in part, through its ability to balance oxidant-antioxidant status, to inhibit neutrophil infiltration, and to regulate the release of inflammatory mediators.     

Silymarin, the antioxidant component of Silybum marianum, protects against burn-induced oxidative skin injury

BACKGROUND: Despite recent advances, severe burn is one of the most common problems faced in the emergency room. Major thermal injury induces the activation of an inflammatory cascade resulting in local tissue damage, to contribute to the development of subsequent damage of multiple organs distant from the original burn wound. OBJECTIVE: Silymarin, the major component of milk thistle has been shown to have antioxidant properties. In the present study, we investigated the putative antioxidant effect of local or systemic silymarin treatment on burn-induced oxidative tissue injury. METHODS: Wistar albino rats were exposed to 90 degrees C bath for 10 s to induce burn. Silymarin either locally (30 mg/kg) applied on 4 cm(2) area or locally+systemically (50 mg/kg, p.o.) was administered after the burn and repeated twice daily. Rats were decapitated 48 h after injury and blood was collected for tumor necrosis factor-alpha (TNF-alpha) and lactate dehydrogenase (LDH) activity. In skin tissue samples malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity, and luminol-lucigenin chemiluminescense (CL) were measured in addition to the histological evaluation. RESULTS: Burn caused a significant increase in TNF-alpha and LDH levels. MDA levels were increased and GSH levels were decreased in the skin at 48 h after-burn. Both local and systemic silymarin treatments significantly reversed these parameters. The raised MPO activity and luminol-lucigenin CL were also significantly decreased. CONCLUSION: Results indicate that both systemic and local administration of silymarin was effective against burn-induced oxidative damage and morphological alterations in rat skin. Therefore, silymarin merits consideration as a therapeutic agent in the treatment of burns.     

大环骨架结构的倍半萜化合物——Ⅵ.马兜铃新内酯的化学结构测定

自绵毛马兜铃(Aristolochia mollissima Hance)根茎中分得九个化合物,其中已报道的七个化合物是尿囊素、马兜铃内酯、绵毛马兜铃内酯、β-谷甾醇、马兜铃酸A、9-乙氧基马兜铃内酯和9-乙氧基马兜铃内酰胺,本文报道结晶K_3的化学结构,经光谱分析(IR,~1H-NMR,~(13)C-NMR,2D-NMR和MS),化学反应及X-衍射晶体分析,确证K_3为一个新骨架结构的倍半萜化合物,命名为马兜铃新内酯。