Use of endobronchial one-way valves reveals questions on etiology of spontaneous pneumothorax: report of three cases

Spontaneous pneumothoraces are believed to arise when air from the supplying airway exit via a ruptured visceral pleural bleb into the pleural cavity. Endobronchial one-way valves (EBVs) allow air exit (but not entry) from individual segmental airways. Systematic deployment of EBVs was applied to three patients with secondary spontaneous pneumothoraces and persistent airleak. In all cases, balloon-catheter occlusion of the upper lobe bronchus stopped the airleak. EBVs applied to individual upper lobe segmental airways failed to terminate the airleak, which only stopped after placements of multiple EBVs to occlude all upper lobe segments. The observation questions the traditional belief of 'one-airway-one-bleb-one-leak' in spontaneous pneumothorax.     

p38 MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) IS ACTIVATED BY NORADRENALINE AND SERVES A CARDIOPROTECTIVE ROLE, WHEREAS ADRENALINE INDUCES p38 MAPK DEPHOSPHORYLATION

• 1 The aim of the present study was to investigate the role of p38 mitogen‐activated protein kinases (MAPK) in mediating the effect of noradrenaline (NA) on cardiomyocyte cell viability.
• 2 Cardiomyocytes from embryonic chick heart were treated with various concentrations of NA, phenylephrine or isoproterenol and p38 MAPK activation was determined by western blotting. Total cell death was assessed by the 3‐(4,5‐dimethyl‐2 thiazoyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide assay. Apoptosis was determined by specific DNA fragmentation.
• 3 At 100 µmol/L, NA produced a significant increase in cell death that was associated with microscopic changes and DNA fragmentation indicative of apoptosis. The p38 MAPK inhibitor SB202190 (at 1 µmol/L beginning 1 h before NA), reduced NA‐induced p38 MAPK activation and significantly accentuated NA‐induced cell death. In contrast, the mitogen‐activated protein kinase kinase ERK1/2 inhibitor PD98059 (at 1 µmol/L beginning 1 h before NA) did not significantly alter NA‐induced cell death. These effects of NA were mediated, in part, through α‐adrenoceptor because phenylephrine (100 µmol/L), like NA, also induced p38 MAPK activation. However, 100 µmol/L isoproterenol produced a sustained dephosphorylation of p38 MAPK.
• 4 These data show that NA‐induced p38 MAPK activation, through α‐adrenoceptor, has a protective role in cardiomyocytes to antagonize NA‐induced cell death. In contrast, β‐adrenoceptor stimulation produces dephosphorylation of p38 MAPK.

     

Beneficial effects of danshensu, an active component of Salvia miltiorrhiza, on homocysteine metabolism via the trans-sulphuration pathway in rats

Background and purpose:

Elevated plasma total homocysteine (tHcy) level has been established as an independent risk factor for cardiovascular diseases. Danshensu, an active ingredient of Salvia miltiorrhiza, shows wide cardiovascular benefit. However, in terms of its own methylation, danshensu could elevate tHcy level, which would act against its cardiovascular benefit, thus posing a ‘therapeutic paradox’. As this paradox has not been fully assessed, we have evaluated the effects of danshensu on tHcy levels to uncover the underlying mechanisms.

Experiment approach:

We evaluated the influence of danshensu on homocysteine (Hcy) metabolism in rats with normal tHcy levels and in rat models of elevated tHcy (single intravenous methionine loading model and a hyperhomocysteinemic model after 3 weeks methionine dosing, with and without 3 weeks of danshensu treatment). We also quantified some metabolic intermediates (S-adenosyl methionine, S-adenosyl-l-homocysteine, cysteine and glutathione) relevant to Hcy metabolism in rat liver and kidney.

Key results:

Acute treatment with a single dose of danshensu in rats with normal tHcy did not change plasma tHcy. In contrast, danshensu significantly lowered tHcy in rats with elevated tHcy. The relatively higher cysteine and glutathione levels after treatment with danshensu indicated that its tHcy-lowering effect was via increased activity of the trans-sulphuration pathway.

Conclusions and implications:

Our results suggested that danshensu may act both acutely to increase trans-sulphuration and after chronic exposure to up-regulate the activity of the trans-sulphuration enzymes. The tHcy-lowering effect of danshensu is another cardiovascular benefit provided by S. miltiorrhiza and suggests a potential tHcy-lowering therapy.     

VDR基因敲除鼠一氧化氮合酶和内皮素-1基因的表达

目的探讨维生素D受体(VDR)基因敲除鼠血压变化以及与血压水平密切相关的内皮型一氧化氮合酶、内皮素-1基因在主动脉的表达情况,了解维生素D、维生素D受体与血压的联系及可能机制。方法小鼠血压采用动脉血管插管法直接测定,主动脉内皮型一氧化氮合酶、内皮素-1基因表达采用实时定量聚合酶链式反应检测。结果内皮型一氧化氮合酶、内皮素-1基因均能在野生型正常鼠及维生素D受体基因敲除鼠主动脉表达。与野生型正常鼠比较,纯合子维生素D受体基因敲除鼠收缩压、舒张压明显升高,主动脉内皮型一氧化氮合酶基因表达明显下调,内皮素-1基因表达明显上调(P均<0.05),杂合子维生素D受体基因敲除鼠收缩压、舒张压及主动脉内皮型一氧化氮合酶、内皮素-1基因表达则无明显改变(P均>0.05)。相关性研究发现主动脉内皮型一氧化氮合酶基因表达水平与收缩压、舒张压水平呈负相关,与收缩压、舒张压水平呈正相关(P均<0.05)。结论纯合子维生素D受体基因敲除鼠存在与血压密切相关的主动脉内皮型一氧化氮合酶、内皮素-1基因表达水平明显异常。     

从髌股关节的生物力学评价髌骨骨折的治疗

从髌股关节的生物力学分析176例髌骨骨折。髌骨骨折后疗效的好坏与髌股关节的生物力学特点及髌骨功能恢复的程度密切相关。治疗髌骨骨折的原则应是保留髌骨，并充分恢复其解剖关系。     

Abnormalities in surfactant in sudden infant death syndrome as a postmortem marker and possible test of risk

To determine whether physical abnormalities in lung surfactant, particularly inversion of the hysteresis between surface tension and surface area, are an effective postmortem marker for sudden infant death syndrome (SIDS).

Methodology:

Bronchoalveolar lavage (BAL) was employed to obtain lung rinsings from 55 infants under 24 months of age at autopsy, comprising 34 index cases and 21 controls. Folch reagent was used to extract the lipoid content which was then applied at two surface concentrations, fixed and BAL-determined (BALD), to the pool of a Langmuir trough in which surface tension (γ) was measured continuously by the Wilhelmy method as surface area ( A ) was cycled.

Results:

The γ: A loops from SIDS samples were inverted relative to controls (i.e. they were hysteresis reversed, this inversion being quantified by an empirical surface tension:area reversal (STAR) score). There was a wide scatter of STAR scores, but a critical value was found which offered a significant ( P = 0.017) separation of SIDS cases from controls for a fixed surface concentration and a highly significant separation ( P = 1.0 × 10^-4) for BALD surface concentrations. Differences in the yields of phospholipid and proteolipid, or their correlation to STAR scores, did not reach statistical significance.

Conclusions:

Inversion of the γ: A loops (i.e. hysteresis inversion) would appear to offer a better postmortem marker of SIDS than any reported previously, the procedure having potential for development as a prospective test indicating the risk of this disease.