PO2 cycling reduces diaphragm fatigue by attenuating ROS formation

Prolonged muscle exposure to low PO₂ conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO₂ cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr) followed by a high oxygen level (550 Torr), can reduce intracellular reactive oxygen species (ROS) as well as attenuate muscle fatigue in mouse diaphragm under low PO₂. Accordingly, dihydrofluorescein (a fluorescent probe) was used to monitor muscular ROS production in real time with confocal microscopy during a lower PO₂ condition. In the control group with no PO₂ cycling, intracellular ROS formation did not appear during the first 15 min of the low PO₂ period. However, after 20 min of low PO₂, ROS levels increased significantly by ∼30% compared to baseline, and this increase continued until the end of the 30 min low PO₂ condition. Conversely, muscles treated with PO₂ cycling showed a complete absence of enhanced fluorescence emission throughout the entire low PO₂ period. Furthermore, PO₂ cycling-treated diaphragm exhibited increased fatigue resistance during prolonged low PO₂ period compared to control. Thus, our data suggest that PO₂ cycling mitigates diaphragm fatigue during prolonged low PO₂. Although the exact mechanism for this protection remains to be elucidated, it is likely that through limiting excessive ROS levels, PO₂ cycling initiates ROS-related antioxidant defenses.

[Diaphragmatic lipoma needed to distinguish from Bochdalek hernia; report of a case]

A 69-year-old woman had been followed up for an abnormal shadow on the left diaphragm at a nearby hospital, which showed gradual increase in size and she was referred to our hospital for treatment. Chest computed tomography(CT) showed a dome-shaped and homogeneous mass with smooth surface on the left diaphragm. CT showed 50×60 mm hypodense mass and partly interrupted diaphragm. Magnetic resonance imaging( MRI) revealed fat signal intensity on both T1 and T2 weighted image and fat suppressed T1 image. Bochdalek hernia or diaphragm lipoma was suggested and surgery was done. Yellowish round tumor on the diaphragm was resected. The omentum was easily separated from the tumor. Histopathological finding revealed the lipoma cell invading into striated muscle of diaphragm, and the tumor was diagnosed as a mature lipoma originated from diaphragm.

Perihepatic adhesions: An unusual complication of hemolysis, elevated liver enzymes and low platelet syndrome

We present a case of symptomatic perihepatic adhesions, which developed after a pregnancy complicated by hemolysis, elevated liver enzymes and low platelet (HELLP) syndrome, in which a subcapsular liver hematoma occurred. Our patient presented with complaints of persistent, severe right-sided upper abdominal pain. The complaints developed gradually, one year after a pregnancy that had been complicated by HELLP syndrome with a subcapsular liver hematoma. The hematoma had resolved spontaneously. An upper-abdominal magnetic resonance imaging revealed a density between liver and diaphragm at the site of the former subcapsular hematoma, suspect of perihepatic adhesions. The presence of perihepatic adhesions was confirmed during a laparoscopy and treated by adhesiolysis in the same session. The adhesions may have developed in response to the degradation process of the subcapsular liver hematoma during conservative treatment. This case of perihepatic adhesions may therefor be the first presentation of a long term sequel of subcapsular liver hematoma in HELLP syndrome.

Widespread sequence variations in VAMP1 across vertebrates suggest a potential selective pressure from botulinum neurotoxins

Botulinum neurotoxins (BoNT/A-G), the most potent toxins known, act by cleaving three SNARE proteins required for synaptic vesicle exocytosis. Previous studies on BoNTs have generally utilized the major SNARE homologues expressed in brain (VAMP2, syntaxin 1, and SNAP-25). However, BoNTs target peripheral motor neurons and cause death by paralyzing respiratory muscles such as the diaphragm. Here we report that VAMP1, but not VAMP2, is the SNARE homologue predominantly expressed in adult rodent diaphragm motor nerve terminals and in differentiated human motor neurons. In contrast to the highly conserved VAMP2, BoNT-resistant variations in VAMP1 are widespread across vertebrates. In particular, we identified a polymorphism at position 48 of VAMP1 in rats, which renders VAMP1 either resistant (I48) or sensitive (M48) to BoNT/D. Taking advantage of this finding, we showed that rat diaphragms with I48 in VAMP1 are insensitive to BoNT/D compared to rat diaphragms with M48 in VAMP1. This unique intra-species comparison establishes VAMP1 as a physiological toxin target in diaphragm motor nerve terminals, and demonstrates that the resistance of VAMP1 to BoNTs can underlie the insensitivity of a species to members of BoNTs. Consistently, human VAMP1 contains I48, which may explain why humans are insensitive to BoNT/D. Finally, we report that residue 48 of VAMP1 varies frequently between M and I across seventeen closely related primate species, suggesting a potential selective pressure from members of BoNTs for resistance in vertebrates.

Botulinum neurotoxins (BoNTs) target peripheral motor neurons and act by cleaving SNARE proteins, which are essential for neurotransmitter release from nerve terminals. SNARE proteins occur in multiple homologues and it has been difficult to determine which one is the physiologically relevant toxin target in motor nerve terminals among closely related SNARE homologues such as VAMP1 and VAMP2. Here we report that, in contrast to the highly conserved VAMP2, sequence variations in VAMP1 that confer resistance to BoNTs are widespread across vertebrates. In particular, residue 48 of VAMP1 is polymorphic between BoNT/D-sensitive residue M and BoNT/D-resistant residue I in rats. Taking advantage of this finding, we carried out an intra-species comparison, which showed that diaphragm motor nerve terminals from rats with I48 in VAMP1 were insensitive to BoNT/D as compared to those with M48. Since VAMP2 is conserved in rats, these data demonstrate that VAMP1 is the physiologically relevant toxin target in motor neurons. Interestingly, human VAMP1 encodes the BoNT/D-resistant residue I48, which may explain why humans are insensitive to BoNT/D. Finally, we found that residue 48 of VAMP1 switches frequently between M and I among 17 primate species, suggesting a potential selective pressure from BoNT/D for resistance in primates.

[Computed tomography-guided percutaneous microwave ablation for diaphragm-abutting liver tumors: assessments of safety and short-term therapeutic efficacies]

OBJECTIVE

To assess the safety and short-term therapeutic efficacies of computed tomography (CT)-guided percutaneous microwave ablation (PMA) for diaphragm-abutting liver tumors.

METHODS

A total of 69 patients with 75 diaphragm-abutting liver tumors (tumor from diaphragmc ≤ 5 mm) underwent CT-guided PMA. According to the site of diaphragm-abutting lesions, they were divided into neighboring muscle group (group A) and neighboring aponeurosis group (group B); According to the size of lesions, they were divided into <2.5 cm group (group I) and ≥ 2.5 cm group (group II). The complications of intra and post-ablation within 2 weeks were recorded. They underwent contrast enhanced CT (CECT) or contrast enhanced MRI (CEMRI) at Month 1, 3 and 6 post-ablation. Then CEMRI or CECT was re-checked every 3-6 months. All patients were followed up for 12-30 months. Comparative analyses were performed for short-term therapeutic efficacies.

RESULTS

At Month 1 post-PMA, complete response (CR) rate was 86.7% (65/75) and incomplete response (ICR) rate 13.3% (10/75). After additional ablation, 5 lesions transformed into CR.No statistical difference in CR rate existed between groups A and B (95.0% vs 77.1%). The CR rate of group I was obviously higher than that of group II (95.0% vs 77.1%). The 1-year survival rate was 97.1%. The occurring rate of minor complications was 42.0% (29/69) and that of serious complications 2.9% (2/69).No statistical difference of occurring rates of minor complications existed between groups A and B(38.1%vs 45.5%). But the occurring rates of diaphragmatic burns, pulmonary exudation and pneumothorax had obvious statistical differences between two groups. The occurring rate of minor complications in group I was obviously lower than that of group II (30.0% vs 54.3%) and serious complications occurred in group II. Minor complications were reversible and recovered after non-special or symptomatic treatment. Two cases of serious complications improved after standard clinical treatment.

CONCLUSION

CT-guided PMA for diaphragm-abutting liver tumors is both safe and effective.However puncture route and power/time should be optimized according to tumor size and location.

Recovery of diaphragm function following mechanical ventilation in a rodent model

BACKGROUND

Mechanical ventilation (MV) induces diaphragmatic muscle fiber atrophy and contractile dysfunction (ventilator induced diaphragmatic dysfunction, VIDD). It is unknown how rapidly diaphragm muscle recovers from VIDD once spontaneous breathing is restored. We hypothesized that following extubation, the return to voluntary breathing would restore diaphragm muscle fiber size and contractile function using an established rodent model.

METHODS

Following 12 hours of MV, animals were either euthanized or, after full wake up, extubated and returned to voluntary breathing for 12 hours or 24 hours. Acutely euthanized animals served as controls (each n = 8/group). Diaphragmatic contractility, fiber size, protease activation, and biomarkers of oxidative damage in the diaphragm were assessed.

RESULTS

12 hours of MV induced VIDD. Compared to controls diaphragm contractility remained significantly depressed at 12 h after extubation but rebounded at 24 h to near control levels. Diaphragmatic levels of oxidized proteins were significantly elevated after MV (p = 0.002) and normalized at 24 hours after extubation.

CONCLUSIONS

These findings indicate that diaphragm recovery from VIDD, as indexed by fiber size and contractile properties, returns to near control levels within 24 hours after returning to spontaneous breathing. Besides the down-regulation of proteolytic pathways and oxidative stress at 24 hours after extubation further repairing mechanisms have to be determined.

[Thoracic endometriosis and catamenial pneumothorax]

It was analyzed own experience of diagnosis and treatment of catamenial (menstrual) pneumothorax and thoracic endometriosis and literature review. It is shown that catamenial pneumothorax has specific clinical and instrumental signs allowing to establish the diagnosis before surgery. It was proposed surgical treatment including the removal of trans diaphragmatic way of pneumothorax development, removal of thoracic endometriosis and the establishment of reliable pleurodesis. It was demonstrated that this volume of surgery can be successfully implemented by using of thoracoscopic access. Relapse prevention includes hormonal therapy for the 6 months after surgery under the supervision of an obstetrician-gynecologist.

The effect of theophylline on the prevention of mechanical ventilation-induced diaphragm atrophy in rats

BACKGROUND

Movement disorders and atrophy occur in the diaphragm, the most important muscle of respiration, because of mechanical ventilation (MV).

OBJECTIVES

In this animal model, we aimed to evaluate the effect of intravenous theophylline administration on the prevention of mechanical ventilation-induced diaphragmatic atrophy.

MATERIAL AND METHODS

In our study, 30 healthy male Sprague-dawley rats were used. They were divided into 3 equal groups. Group 1: the control group (no MV); group 2: the placebo group that received MV; Group 3: the theophylline group composed of rats that received both MV and theophylline therapy. In all 3 groups, the diaphragmatic atrophy was evaluated histopathologically.

RESULTS

In the histopathological examination, no macroscopic thickening and microscopic atrophy were observed in the diaphragm in the control group. In the placebo group (group 2), macroscopically definite thickening was observed in all rats, and microscopically, heavy (+++) atrophy was observed. In the theophylline group (group 3), there was no atrophy in one rat. In 8 rats, light (+), and in 1 rat medium (++) atrophy was observed.

CONCLUSIONS

In our study, it was shown that atrophy occurred in the diaphragms of rats after MV, and the atrophy was decreased after theophylline administration.

Pancreatic herniation: a rare cause of acute pancreatitis?

Acute pancreatitis is a common and potentially fatal condition, with several well-known causes including gallstones, excessive alcohol consumption and specific medications. We report a case of an 89-year-old man presenting with acute pancreatitis, which we believe to be secondary to a diaphragmatic herniation of the pancreas. This extremely rare anatomical abnormality can be found incidentally in the asymptomatic patient or may present with a variety of acute symptoms. However, there have been only isolated reports of these cases presenting as acute pancreatitis. While the majority of acute pancreatitis cases can be explained by common causes, it is important that clinicians be aware of and should consider investigating for other more unusual possibilities, such as pancreatic herniation, before labelling an episode as 'idiopathic'.

Complex suicide by self-stabbing with subsequent drowning in the sea

The paper presents a unique case of a complex suicide committed by a young man, mostly probably triggered by a disappointment in love. The uniqueness of the suicide lies in the fact that the victim inflicted several deep stab wounds on himself, in the chest and abdomen, while standing partly submerged in the sea and, having done so, he dropped and disappeared in the water. The postmortem examination showed, apart from deep wounds in the trunk, characteristics of drowning that manifested itself in the form of aqueous emphysema of the lungs. Suicide was clearly determined on the basis of the circumstances preceding death, the location, and arrangement of the trunk wounds and the testimony given by a witness of the incident. The circumstances preceding the suicidal act clearly suggest an underlying undiagnosed mental disorder.

The anticancer drug tamoxifen counteracts the pathology in a mouse model of duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a severe disorder characterized by progressive muscle wasting,respiratory and cardiac impairments, and premature death. No treatment exists so far, and the identification of active substances to fight DMD is urgently needed. We found that tamoxifen, a drug used to treat estrogen-dependent breast cancer, caused remarkable improvements of muscle force and of diaphragm and cardiac structure in the mdx(5Cv) mouse model of DMD. Oral tamoxifen treatment from 3 weeks of age for 15 months at a dose of 10 mg/kg/day stabilized myofiber membranes, normalized whole body force, and increased force production and resistance to repeated contractions of the triceps muscle above normal values. Tamoxifen improved the structure of leg muscles and diminished cardiac fibrosis by~ 50%. Tamoxifen also reduced fibrosis in the diaphragm, while increasing its thickness,myofiber count, and myofiber diameter, thereby augmenting by 72% the amount of contractile tissue available for respiratory function. Tamoxifen conferred a markedly slower phenotype to the muscles.Tamoxifen and its metabolites were present in nanomolar concentrations in plasma and muscles,suggesting signaling through high-affinity targets. Interestingly, the estrogen receptors ERa and ERb were several times more abundant in dystrophic than in normal muscles, and tamoxifen normalized the relative abundance of ERb isoforms. Our findings suggest that tamoxifen might be a useful therapy for DMD.

[The proteasome inhibitor MG132 attenuates skeletal muscle atrophy in a rat model of chronic obstructive pulmonary disease]

OBJECTIVE

To investigate the effect of the proteasome inhibitor MG-132 on skeletal muscle atrophy in a rat model of chronic obstructive pulmonary disease (COPD) and its potential mechanisms.

METHODS

The COPD rat model was established by instillation of LPS and exposure to the cigarette smoke. Then the COPD rats were randomly divided into 3 groups (each group n = 12): COPD model control group, MG-132 high dose group (MG-132 0.1 mg·kg(-1)·d(-1)) and low dose group (MG-132 0.05 mg·kg(-1)·d(-1)), and normal control group. After 1 week and 4 week, 6 rats of each group were sacrificed, and then the following parameters were determined: the weight of the diaphragm muscle, the concentration of TNF-α in the serum and diaphragm via enzyme-linked immunosorbent assay (ELISA). Muscle atrophy F-box protein (MAFbx), NF-κBp65, and IκB-α mRNA levels were determined by RT-PCR. The protein levels of MAFbx, NF-κBp65 and IκB-α in diaphragm were measured by Western blot. The single factor analysis of variance was used for statistical analysis among the groups, while t test was used for comparison between 2 groups, and Pearson linear correlation analysis was also performed.

RESULTS

The weight of diaphragm muscle from 1 week and 4 week normal control group [(0.99 ± 0.06) mg and (1.20 ± 0.04) mg] were reduced as compared to those of COPD model control group [(0.83 ± 0.09) mg and (1.01 ± 0.06) mg], high dose group [(0.85 ± 0.02) mg and (1.11 ± 0.06) mg], and low dose group [(0.83 ± 0.03) mg and (1.04 ± 0.02) mg]. The reduction of diaphragm muscle weight in the high dose group and the low dose group was significantly less than that in the COPD model control group, with a more marked difference as compared with the 4 week high dose group. The TNF-α levels in diaphragm from 4 week high dose group [(106 ± 8) ng/L] and low dose group [(122 ± 7) ng/L] were decreased as compared to that of the COPD model control group [(143 ± 24) ng/L]. The levels of NF-κBp65 and MAFbx mRNA from the 4 week high dose group (2.17 ± 0.42) and low dose group (1.74 ± 0.14) and the protein expression (1.13 ± 0.04 and 1.27 ± 0.05) were also decreased as compared to those of the COPD model control group (mRNA 2.81 ± 0.31 and 4.87 ± 0.34, protein expression 1.32 ± 0.04 and 1.44 ± 0.07). The levels of IκB-α mRNA and protein expression (0.96 ± 0.08 and 0.83 ± 0.06) were higher than those of the COPD model control group (0.25 ± 0.02 and 0.58 ± 0.06), (t = 1.57-24.9, P < 0.05). The levels of the TNF-α levels in serum and diaphragm were correlated positively with the levels of MAFbx and NF-κBp65 mRNA and protein expression (r = 0.672-0.875, P < 0.01), but negatively with the levels of IκB-α mRNA and protein expression (r = -0.656--0.927, P < 0.01).

CONCLUSIONS

The proteasome inhibitor MG-132 significantly inhibited IκB-α degradation thus preventing NF-κB activation. This effect resulted in preventing skeletal muscle atrophy in the COPD rats.

Construction and in vivo evaluation of a dual layered collagenous scaffold with a radial pore structure for repair of the diaphragm

In each organ the extracellular matrix has a specific architecture and composition, adapted to the functional needs of that organ. As cells are known to respond to matrix organization, biomaterials that take into account the specific architecture of the tissues to be regenerated may have an advantage in regenerative medicine. In this study we focussed on the diaphragm, an organ essential for breathing, and consisting of radial oriented skeletal muscle fibres diverging from a central tendon plate. To mimic this structure dual layered collagenous scaffolds were constructed with a radial pore orientation, prepared by inward out freezing, and reinforced by a layer of compressed collagen. Similar scaffolds with a random round pore structure were taken as controls. Scaffolds were first mildly crosslinked by formaldehyde vapour fixation for initial stabilization (13% and 17% crosslinking for the radial and control scaffolds, respectively), and further crosslinked using aqueous 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (38% and 37% crosslinking, respectively). Scaffolds were implanted into a surgically created diaphragm defect in rats and explanted after 12weeks. Macroscopically, integration of the radial scaffolds with the surrounding diaphragm was better compared with the controls. Cells had infiltrated further into the centre of the scaffolds (P=0.029) and there was a tendency of blood vessels to migrate deeper into the radial scaffolds (P=0.057, compared with controls). Elongated cells (SMA-positive) were aligned with the radial structures. In conclusion, collagenous scaffolds with a stable radial pore structure can be constructed which facilitate cellular in-growth and alignment in vivo.

Targeted delivery of TrkB receptor to phrenic motoneurons enhances functional recovery of rhythmic phrenic activity after cervical spinal hemisection

Progressive recovery of rhythmic phrenic activity occurs over time after a spinal cord hemisection involving unilateral transection of anterolateral funiculi at C₂ (SH). Brain-derived neurotrophic factor (BDNF) acting through its full-length tropomyosin related kinase receptor subtype B (TrkB.FL) contributes to neuroplasticity after spinal cord injury, but the specific cellular substrates remain unclear. We hypothesized that selectively targeting increased TrkB.FL expression to phrenic motoneurons would be sufficient to enhance recovery of rhythmic phrenic activity after SH. Several adeno-associated virus (AAV) serotypes expressing GFP were screened to determine specificity for phrenic motoneuron transduction via intrapleural injection in adult rats. GFP expression was present in the cervical spinal cord 3 weeks after treatment with AAV serotypes 7, 8, and 9, but not with AAV2, 6, or rhesus-10. Overall, AAV7 produced the most consistent GFP expression in phrenic motoneurons. SH was performed 3 weeks after intrapleural injection of AAV7 expressing human TrkB.FL-FLAG or saline. Delivery of TrkB.FL-FLAG to phrenic motoneurons was confirmed by FLAG protein expression in the phrenic motor nucleus and human TrkB.FL mRNA expression in microdissected phrenic motoneurons. In all SH rats, absence of ipsilateral diaphragm EMG activity was confirmed at 3 days post-SH, verifying complete interruption of ipsilateral descending drive to phrenic motoneurons. At 14 days post-SH, all AAV7-TrkB.FL treated rats (n = 11) displayed recovery of ipsilateral diaphragm EMG activity compared to 3 out of 8 untreated SH rats (p<0.01). During eupnea, AAV7-TrkB.FL treated rats exhibited 73±7% of pre-SH root mean squared EMG vs. only 31±11% in untreated SH rats displaying recovery (p<0.01). This study provides direct evidence that increased TrkB.FL expression in phrenic motoneurons is sufficient to enhance recovery of ipsilateral rhythmic phrenic activity after SH, indicating that selectively targeting gene expression in spared motoneurons below the level of spinal cord injury may promote functional recovery.

Kif7 is required for the patterning and differentiation of the diaphragm in a model of syndromic congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) is a common birth defect that results in a high degree of neonatal morbidity and mortality, but its pathological mechanisms are largely unknown. Therefore, we performed a forward genetic screen in mice to identify unique genes, models, and mechanisms of abnormal diaphragm development. We identified a mutant allele of kinesin family member 7 (Kif7), the disorganized diaphragm (dd). Embryos homozygous for the dd allele possess communicating diaphragmatic hernias, central tendon patterning defects, and increased cell proliferation with diaphragmatic tissue hyperplasia. Because the patterning of the central tendon is undescribed, we analyzed the expression of genes regulating tendonogenesis in dd/dd mutant embryos, and we determined that retinoic acid (RA) signaling was misregulautted. To further investigate the role of Kif7 and RA signaling in the development of the embryonic diaphragm, we established primary mesenchymal cultures of WT embryonic day 13.5 diaphragmatic cells. We determined that RA signaling is necessary for the expression of tendon markers as well as the expression of other CDH-associated genes. Knockdown of Kif7, and retinoic acid receptors alpha (Rara), beta (Rarb), and gamma (Rarg) indicated that RA signaling is dependent on these genes to promote tendonogenesis within the embryonic diaphragm. Taken together, our results provide evidence for a model in which inhibition of RA receptor signaling promotes CDH pathogenesis through a complex gene network.

Diaphragm atrophy and contractile dysfunction in a murine model of pulmonary hypertension

Pulmonary hypertension (PH) causes loss of body weight and inspiratory (diaphragm) muscle dysfunction. A model of PH induced by drug (monocrotaline, MCT) has been extensively used in mice to examine the etiology of PH. However, it is unclear if PH induced by MCT in mice reproduces the loss of body weight and diaphragm muscle dysfunction seen in patients. This is a pre-requisite for widespread use of mice to examine mechanisms of cachexia and diaphragm abnormalities in PH. Thus, we measured body and soleus muscle weight, food intake, and diaphragm contractile properties in mice after 6-8 weeks of saline (control) or MCT (600 mg/kg) injections. Body weight progressively decreased in PH mice, while food intake was similar in both groups. PH decreased (P<0.05) diaphragm maximal isometric specific force, maximal shortening velocity, and peak power. Protein carbonyls in whole-diaphragm lysates and the abundance of select myofibrillar proteins were unchanged by PH. Our findings show diaphragm isometric and isotonic contractile abnormalities in a murine model of PH induced by MCT. Overall, the murine model of PH elicited by MCT mimics loss of body weight and diaphragm muscle weakness reported in PH patients.

[The morphological alteration of the diaphragm in patients with chronic obstructive pulmonary disease with three-dimensional reconstruction of 64-slice spiral CT]

OBJECTIVE

To study the morphological alteration of the diaphragm with three-dimensional reconstruction in patients with chronic obstructive pulmonary disease (COPD), and to evaluate the relationship between morphological parameters and pulmonary function.

METHODS

Subjects were consecutively recruited in Shanghai East Hospital of Tongji University from July 2010 to April 2011. They were divided into a COPD (30 males) group, including mild (n = 10), moderate (n = 10), and severe/very severe (n = 10), and a control group (20 males); with the age of the subjects ranging from 45 to 80 years old. The subjects were asked to take pulmonary function test. Each subject underwent CT scanning in residual volume (RV) and total lung capacity (TLC) phases. The imaging of CT scanning was used to reconstruct three-dimensional diaphragm with the special computer software. The length of total diaphragm (Ldi), including the part of the zone apposition (Lap) and part of the dome (Ldo) under coronal (C) and sagittal (S) were observed. The surface area of the diaphragm (Adi), surface area (Aap) of the zone of apposition and surface area (Ado) of the dome were measured as well. In addition, the relationship between morphological indexs and pulmonary function were evaluated.

RESULTS

In RV phase, compared with the control, Ldi and Lap were significantly lower in COPD, S-Ldi: (23.3 ± 2.9) cm vs (31.1 ± 4.3) cm (t = 4.12, P < 0.05); S-Lap: (5.4 ± 1.9) cm vs (12.7 ± 2.0) cm, (t = 6.96, P < 0.05); the difference was more obvious in sagittal slices as compared to the coronal slices. The reduction of S-Ldi was more pronounced in the part of S-Lap. In RV phase, Adi and Aap were also significant lower in COPD, Adi: (571 ± 119) cm(2) vs (811 ± 95) cm(2) (t = 4.06, P < 0.05). Aap: (270 ± 99) cm(2) vs (471 ± 61) cm(2) (t = 4.33, P < 0.05). Aap decreased more significantly, and accounted for the most part of reduction of Adi. There was a significant positive correlation between Aap and S-Lap with pulmonary function (r = 0.577 - 0.787, all P < 0.05), especially for Aap (r = 0.787). In TLC phase, only C-Ldi and C-Lap decreased significantly (t = 3.08, t = 2.80 respectively, all P < 0.05).

CONCLUSIONS

The diaphragmatic length and surface area decreased in patients with COPD, which were more pronounced in the part of the zone of apposition and occurred during RV phase. The dimension of the zone of apposition could be a parameter to reflect the severity of the disease.

[The catamenial pneumothorax: a diagnosis often overlooked]

The catamenial pneumothorax (CP) is defined as recurrent pneumothorax occurring from the day before menstruations until 72 hours after their beginning, but remains a diagnostic and therapeutic problem. We herein report the cases of two young women who presented several episodes of pneumothorax. The first patient (28 years old) underwent 18 recurrent pneumothorax before the diagnosis of CP. The video-assisted mini-thoracotomy found many diaphragmatic perforations, which were sutured after resection and biopsy. The latter patient underwent four pneumothorax before diagnosis of CP. A video-assisted mini-thoracotomy associated with pleurectomy and pleural freshening was then performed. CP is a rare entity of spontaneous pneumothorax often associated with thoracic endometriosis. The difficulty remains in diagnosis (diagnostic delay before the start of appropriate care), as well as in the treatment. Overall, CP requires a multidisciplinary approach combining pulmonology, thoracic surgery and gynecology.

Roundabout receptors are critical for foregut separation from the body wall

In mammals, precise placement of organs is essential for survival. We show here that inactivation of Roundabout (Robo) receptors 1 and 2 in mice leads to mispositioning of the stomach in the thoracic instead of the abdominal cavity, which likely contributes to poor lung inflation and lethality at birth, reminiscent of congenital diaphragmatic hernia (CDH) cases in humans. Unexpectedly, in Robo mutant mice, the primary defect preceding organ misplacement and diaphragm malformation is a delayed separation of foregut from the dorsal body wall. Foregut separation is a rarely considered morphogenetic event, and our data indicate that it occurs via repulsion of Robo-expressing foregut cells away from the Slit ligand source. In humans, genomic lesions containing Robo genes have been documented in CDH. Our findings suggest that separation of the foregut from the body wall is genetically controlled and that defects in this event may contribute to CDH.

[Surgery of the diaphragm in the planned thoracic surgery]

122 patients with different diseases of the diaphragm were operated on during 1963-2011 yy. The majority of patients - 76 (62.3%) - had hernias of the weak phrenic zones. 14 (11.5%) and 17 (14.0%) patients had posttraumatic hernia and phrenic relaxation, respectively. The majority of patients had no complaints and the disease was diagnosed on the X-ray examination. Rarely, the compression syndrome, caused by the translocation of the bowel into the thoracic cavity, was registered. That clinically emerged as short breath, heaviness sensation and cardiac rhythm disorders. The worked out reconstructive operations allow to cure such patients with minimal risk.

Chronic intrinsic transient tracheal occlusion elicits diaphragmatic muscle fiber remodeling in conscious rodents

BACKGROUND

Although the prevalence of inspiratory muscle strength training has increased in clinical medicine, its effect on diaphragm fiber remodeling is not well-understood and no relevant animal respiratory muscle strength training-rehabilitation experimental models exist. We tested the postulate that intrinsic transient tracheal occlusion (ITTO) conditioning in conscious animals would provide a novel experimental model of respiratory muscle strength training, and used significant increases in diaphragmatic fiber cross-sectional area (CSA) as the primary outcome measure. We hypothesized that ITTO would increase costal diaphragm fiber CSA and further hypothesized a greater duration and magnitude of occlusions would amplify remodeling.

METHODOLOGY/PRINCIPAL FINDINGS

Sprague-Dawley rats underwent surgical placement of a tracheal cuff and were randomly assigned to receive daily either 10-minute sessions of ITTO, extended-duration, 20-minute ITTO (ITTO-20), partial obstruction with 50% of cuff inflation pressure (ITTO-PAR) or observation (SHAM) over two weeks. After the interventions, fiber morphology, myosin heavy chain composition and CSA were examined in the crural and ventral, medial, and dorsal costal regions. In the medial costal diaphragm, with ITTO, type IIx/b fibers were 26% larger in the medial costal diaphragm (p<0.01) and 24% larger in the crural diaphragm (p<0.05). No significant changes in fiber composition or morphology were detected. ITTO-20 sessions also yielded significant increases in medial costal fiber cross-sectional area, but the effects were not greater than those elicited by 10-minute sessions. On the other hand, ITTO-PAR resulted in partial airway obstruction and did not generate fiber hypertrophy.

CONCLUSIONS/SIGNIFICANCE

The results suggest that the magnitude of the load was more influential in altering fiber cross-sectional area than extended-duration conditioning sessions. The results also indicated that ITTO was associated with type II fiber hypertrophy in the medial costal region of the diaphragm and may be an advantageous experimental model of clinical respiratory muscle strength training.

[Concurrent interventions for pulmonary tuberculosis complicated by chronic pleural tuberculosis]

Basing on the literature data analysis the authors suppose the insufficient studying of issues, concerning simultant interventions for pulmonary tuberculosis, coinciding with chronic phthysic pleurytis. Surgical treatment of such processes was performed in 181 patients, total pleurectomy--in 172 (95%) of them, partial--in 9 (5%). Various kinds of pulmonary resection as the additional intervention were performed in 172 (95%) patients, extrapleural thoracoplasty--in 15 (8.3%), diaphragmatic plasty--in 15 (8.3%). In early postoperative period the tuberculosis micobacteria have had disappeared in all the patients, permitting to interpret surgical intervention as a sanation one for every patient, and as a socially directed antiepidemic measure.

Hepatic mesenchymal hamartoma in a neonate with a Bochdalek diaphragmatic hernia: a case report

The Bochdalek diaphragmatic hernia (BDH) is a common birth defect that is associated with other congenital malformations. Hepatic mesenchymal hamartoma (HMH) is the second most common benign hepatic tumor in children. The association between BDH and HMH or ectopic hepatic tissue is uncommon. We report a case of a female newborn with a left BDH that at surgery was incidentally found to have a tumor of 3.5 cm in maximum dimension with a serous muscular membrane. The histopathological study revealed vascular-mesenchymal stroma with bile ducts entrapped and peripheral normal hepatic tissue. These findings correlate with the diagnosis of hepatic mesenchymal hamartoma (HMH) in ectopic hepatic tissue. Our objective is to report a case of a rare association between HMH and BDH as well as discuss its differential diagnosis.

Bronchial carcinosarcoma

Carcinosarcoma is an uncommon mixed tumor of the lung. We present the case of a 65 year-old-male with cough and a right lower lobe radio-opacity who underwent resection, showing a large endobronchial tumor with an epithelial component of non-small cell carcinoma and malignant mesenchymal elements. The radiologic and histopathologic features are reviewed with reference to relevant literature.

[Endometriosis as a cause of pneumothorax]

A young woman, who had formerly been diagnosed with endometriosis, was admitted to hospital with five incidents of right-sided spontaneous pneumothorax. Despite two thoracoscopic operations the pneumothorax reoccurred. The third operation revealed histologically verified endometriotic tissue of the diaphragm causing diaphragmatic fenestrations. It was concluded that the patient suffered from catamenial pneumothorax, where transdiaphragmatic passage of air from the cervix through the peritoneum during the menstruation period is believed to cause pneumothorax.

Effect of Shengmai injection () on diaphragmatic contractility in doxorubicin-treated rats

OBJECTIVE

To explore the diaphragmatic toxicity in doxorubicin (DOX)-treated rats and the related mechanisms, as well as the effects of Shengmai Injection (SMI, ) on the diaphragmatic dysfunction.

METHODS

Thirty Sprague-Dawley male rats were randomly divided into three groups: control, DOX-treated and DOX+SMI treated groups. DOX was given to rats in DOX and DOX+SMI groups in 6 equal doses [2.5 mg/kg, intraperitoneal injection (i.p.)], on alternate days, over a period of 2 weeks for a cumulative dose of 15 mg/kg. SMI was given to DOX+SMI rats in 12 doses (3 mL/kg, i.p.) for a period of 2 weeks before the administration of DOX and 2 weeks during the administration of DOX. The rats in the control group received equal volume of normal saline. Subsequently, the twitch and tetanic characteristics and force-frequency relationships, and the malondialdehyde (MDA) levels and the superoxide dismutase (SOD) activities, as well as the mRNA content and proteins of inducible nitric oxide synthase (iNOS) were determined.

RESULTS

The DOX-treated rats had decreased the peak twitch tension (Pt), maximal tetanic tension (P0) and force-frequency relationship as compared with the control rats (P<0.01), while the diaphragm contractility in rats treated with SMI were significantly higher than that in DOX-treated rats (P<0.01). The DOX-treated rats had increased MAD levels and decreased SOD activities (P<0.05), and SMI decreased the MDA levels and increased the SOD activities in DOX-treated rats (P<0.05). Ultrastructure of diaphragm in the DOX-treated rats revealed typical alterations including fracture of diaphragm fibers, and edema and degeneration of mitochondria; these changes were relieved by SMI treatment. The mRNA content and protein of iNOS in DOX-treated rats were remarkably higher than those in control rats (P<0.01), while SMI decreased the mRNA expression level of iNOS in DOX-treated rats (P<0.05).

CONCLUSIONS

Lipid peroxidation is responsible for DOX-induced diaphragm toxicity. SMI protects diaphragm muscles and their function from DOX impairment, and these beneficial effects may be somehow correlated with the decrease in expression of iNOS and lipid peroxidation.

[Anterior approach liver resection with the liver hanging maneuver. Technique and indications]

The anterior approach liver resection has advantages compared to conventional liver resection. Mobilization during conventional liver resection may cause local pressure on the tumor which could lead to tumor cell dissemination or even to tumor rupture. Furthermore, hemodynamic parameters tend to deteriorate during mobilization due to compression or twisting of the inferior vena cava. In addition, the left liver lobe often is compressed which can lead to tissue damage of the residual parenchyma. The risk of these complications can be reduced by the anterior approach technique which is facilitated by the so-called liver hanging maneuver. Appropriate indications for this technique are large tumors of the right liver lobe, tumors with infiltration of the right hepatic vein and infiltration of the vena cava from the right side, tumors with infiltration of the diaphragm and tumors of the right lobe after previous resections of the right lobe.

Pax3 gene expression is not altered during diaphragmatic development in nitrofen-induced congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Malformations of the pleuroperitoneal folds (PPFs) have been identified as the origin of the diaphragmatic defect in congenital diaphragmatic hernia (CDH). Pax3, expressed in muscle precursor cells (MPCs), plays a key role in regulating myogenesis and muscularization in the fetal diaphragm. Pax3 mutant mice display absence of muscular diaphragm. However, the distribution of muscle precursor cells is reported to be normal in the PPF of the nitrofen-CDH model. We designed this study to investigate the hypothesis that Pax3 gene expression is unaltered in the PPF and developing diaphragm in the nitrofen-induced CDH model.

METHODS

Pregnant rats were treated with nitrofen or vehicle on gestational day (D) 9 and sacrificed on D13, D18, and D21. Pleuroperitoneal folds (D13) and developing diaphragms (D18 and D21) were dissected, total RNA was extracted, and real-time quantitative polymerase chain reaction was performed to determine Pax3 messenger RNA levels. Confocal immunofluorescence microscopy was performed to evaluate protein expression/distribution of Pax3.

RESULTS

Relative messenger RNA expression levels of Pax3 in PPFs and developing diaphragms were not significantly different in the nitrofen group compared with controls. Intensity of Pax3 immunofluorescence was also not altered in PPFs and developing diaphragms of the nitrofen group compared with controls.

CONCLUSION

Pax3 gene expression is not altered in the PPFs and developing diaphragm of nitrofen-CDH model, suggesting that the diaphragmatic defect is not caused by disturbance of myogenesis and muscularization.

Minimising critical organ irradiation in limited stage Hodgkin lymphoma: a dosimetric study of the benefit of involved node radiotherapy

BACKGROUND

Chemotherapy plus radiotherapy is the standard of care for patients with limited stage Hodgkin lymphoma (HL). Radiotherapy is evolving from involved field radiotherapy (IFRT) to involved node radiotherapy (INRT) to decrease radiotherapy-related morbidity. In the absence of long-term toxicity data, dose-volume metrics of organs at risk (OAR) provide a surrogate measure of toxicity risk.

PATIENTS AND METHODS

Ten female patients with stage I-IIA supradiaphragmatic HL were randomly selected. All patients had pre-chemotherapy computerised tomography (CT) and CT-positron emission tomography staging. Using CT planning, three radiotherapy plans were produced per patient: (i) IFRT, (ii) INRT using parallel-opposed beams and (iii) INRT using volumetric modulated arc therapy (VMAT). Radiotherapy dose was 30.6 Gy in 1.8 Gy fractions. OAR evaluated were lungs, breasts, thyroid, heart and coronary arteries.

RESULTS

Compared with IFRT, INRT significantly reduced mean doses to lungs (P < 0.01), breasts (P < 0.01), thyroid (P < 0.01) and heart (P < 0.01), on Wilcoxon testing. Compared with conventional INRT, VMAT improved dose conformality but increased low-dose radiation exposure to lungs and breasts. VMAT reduced the heart volume receiving 30 Gy (V30) by 85%.

CONCLUSIONS

Reduction from IFRT to INRT decreased the volumes of lungs, breasts and thyroid receiving high-dose radiation, suggesting the potential to reduce long-term second malignancy risks. VMAT may be useful for patients with pre-existing heart disease by minimising further cardiac toxicity risks.

[Cytokines and resistive breathing]

This review summarizes and analyzes the results of the present experimental studies indicating immune system involvement in control of breathing. The hypothesis about the role of cytokines in the mechanisms of respiratory muscle fatigue and reduced ventilatory sensitivity to hypercapnia during respiration with the added resistive loading is justified. The possible ways of implementing of respiratory cytokine effects are discussed.

[MDCT features and anatomic-pathological basis of the diseases in central thoracic-abdominal junctional region]

This paper is to determine relationship between MDCT features and anatomic-pathology of the diseases in central thoracic-abdominal junctional region. 3 cadavers were cut transversely and another 3 vertically to observe the anatomy of thoracic-abdominal junctional zone. 93 patients with diseases in central thoracic-abdominal junctional zone were scanned with MDCT. The correlation between MDCT features of the diseases in central thoracic-abdominal junctional region and the anatomic-pathology of the diseases in this region was evaluated. On cadaver sections, central thoracic-abdominal junctional region was an area between anterior chest wall and dorsal spine in vertical direction. The region was separated into upper and lower sections by diaphragm. The upper section mainly contains heart and pericardium, while the lower contains broad ligament and left lobe of liver. The hiatus of diaphragm are vena caval foramen, esophageal foramen and aortic foramen in anterior-posterior turn. In the present study, 23 patients had portal hypertension, 18 had dissection of aorta, 8 got diseases in inferior vena cava, 9 had lymphoma, 12 got diseases in multiple vertebrae, 7 had lower thoracic esophageal carcinoma accompanied with metastasis in upper abdominal lymph nodes, 9 had carcinoma of abdominal esophagus and/or gastric cardia, 4 had esophageal hiatal hernia and 3 patients had neurogenic tumor in posterior mediastinum and/or superior spatium retroperitoneale. The MDCT features and distribution of the diseases in central thoracic-abdominal junctional region influence the anatomic-pathology characteristics in this region.

Effect of intraperitoneal radiotelemetry instrumentation on voluntary wheel running and surgical recovery in mice

Radiotelemetry transmitters support tracking of physiologic variables in conscious animals, but the size of the transmitter may alter animal health and behavior. We hypothesized that the size of the device adversely affects body weight, food intake, water intake, circadian core temperature, activity, voluntary running patterns, and the health of internal organs and that these negative effects can be minimized with smaller transmitter devices. Male C57BL/6J mice (weight, 20 to 24 g) were implanted with small (1.1 g, 0.52 mL) or large (3.5 g, 1.75 mL) radiotransmitters. Recovery of presurgical body weight, food intake, and water intake occurred within 3 d in mice implanted with small transmitter and 9 d in those with large transmitters. Mice with small transmitters displayed robust circadian core body temperature and activity patterns within 1 d after surgery, whereas activity was depressed in mice with large transmitters throughout experimentation. The most robust effects of the large transmitter included significantly reduced voluntary running, which never recovered to baseline, and inflammation of the diaphragm, large intestine, and duodenum. These results demonstrate that the large transmitter delayed surgical recovery, disrupted normal growth, reduced voluntary running, and induced inflammatory reactions of the internal organs of mice. The choice of radiotelemetry transmitter can significantly affect the health and wellbeing of experimental mice as well as data quality, such that the smallest transmitter device available and appropriate to the situation should be chosen for experimentation.

Diaphragm muscle weakness in an experimental porcine intensive care unit model

In critically ill patients, mechanisms underlying diaphragm muscle remodeling and resultant dysfunction contributing to weaning failure remain unclear. Ventilator-induced modifications as well as sepsis and administration of pharmacological agents such as corticosteroids and neuromuscular blocking agents may be involved. Thus, the objective of the present study was to examine how sepsis, systemic corticosteroid treatment (CS) and neuromuscular blocking agent administration (NMBA) aggravate ventilator-related diaphragm cell and molecular dysfunction in the intensive care unit. Piglets were exposed to different combinations of mechanical ventilation and sedation, endotoxin-induced sepsis, CS and NMBA for five days and compared with sham-operated control animals. On day 5, diaphragm muscle fibre structure (myosin heavy chain isoform proportion, cross-sectional area and contractile protein content) did not differ from controls in any of the mechanically ventilated animals. However, a decrease in single fibre maximal force normalized to cross-sectional area (specific force) was observed in all experimental piglets. Therefore, exposure to mechanical ventilation and sedation for five days has a key negative impact on diaphragm contractile function despite a preservation of muscle structure. Post-translational modifications of contractile proteins are forwarded as one probable underlying mechanism. Unexpectedly, sepsis, CS or NMBA have no significant additive effects, suggesting that mechanical ventilation and sedation are the triggering factors leading to diaphragm weakness in the intensive care unit.

[Catamenial pneumothorax due to diaphragmatic endometriosis confirmed by histological examination; report of a case]

We reported a case of catamenial pneumothorax caused by diaphragmatic endometriosis that was histologically confirmed. A 49-year-old female who had recurrent chest pain and cough appearing on the day preceding each menstruation from 5 years ago. These episode suggested catamenial pneumothorax. Thoracotomy revealed the characteristic appearances of catamenial pneumothorax such as blueberry spots and multiple small holes on the central tendon of the right diaphragm. But there were no lesions on the visceral pleura of the lung. Partial resection of the diaphragm including these lesions were performed. Histological examination showing positive for estrogen receptor and progesterone receptor confirmed the presence of endometrial tissue on the diaphragm. The patient has been well controlled by therapy with gonadotropin releasing hormone, without recurrence of catamenial pneumothorax.

[MDCT features and anatomic-pathology in right thoracic-abdominal junctional region diseases]

This paper was objected to determine the relationship between MDCT features and anatomic-pathology of diseases in right thoracic-abdominal junctional region. We cut 3 cadavers transversely and another 3 vertically to observe the anatomy of thoracic-abdominal junctional zone. We scanned 69 patients with diseases in right thoracic-abdominal junctional zone by MDCT. The correlation between MDCT features of right thoracic-abdominal junctional region and the anatomic-pathology in this region was evaluated. We found results as that in cadaver sections, the right pulmonary ligament, which was below inferior pulmonary vein, attached the inferior lobe of right lung to the esophagus, that the coronary ligament, which interiorly extended from falciform ligament and laterally formed into right triangular ligament, contained two layers, and that the bare area of liver, which positioned between the two layers of coronary ligament, was directly next to diaphragm with no peritoneum covered. There were 50 cases with both pleural and ascitic fluid, while the pleural fluid was divided into anterior and posterior compartments by the right pulmonary ligament, whereas the ascitic fluid was limited in perihepatic space in majority. Among the 50 cases, 5 patients had lung cancer with diaphragmatic pleura, diaphragm and upper abdomen involved. 5 patients had right hepatic lobe cancer with subdiaphragmatic peritoneum, crura diaphragmatis and lower thoracic cavity involved. 1 patient had right adrenal carcinoma with phrenic metastasis. 8 patients had inflammation in right lower thorax and/or right upper abdomen. The spreads of these diseases include mainly direct invasion, blood and lymphatic spread routs in the region. Conclusion could be drawn that the MDCT features and distribution of right thoracic-abdominal junctional region diseases correlate with the anatomical characteristics in this region.

Long term follow-up in high-risk congenital diaphragmatic hernia survivors: patching the diaphragm affects the outcome

BACKGROUND/PURPOSE

The increased survival rate reached in infants with congenital diaphragmatic hernia (CDH) has shown a concomitant increase in late morbidity. A recent report from CDH Study Group showed that dimension of diaphragmatic defect is the only independent risk factor of mortality. However, the influence of defect size on late morbidity is still controversial. The aim of the study was to evaluate the influence of patch repair (proxy of diaphragmatic defects size) on midterm morbidity.

METHODS

All high-risk (prenatal diagnosis and/or respiratory symptoms within 6 hours of life) CDH survivors treated at our institution from 2004 to 2008 were followed up in a multidisciplinary outpatient clinic as part of a longitudinal prospective study. Auxological, gastroesophageal, pulmonary, and orthopedic evaluations were performed at 6, 12, and 24 months of age. Patient outcomes were compared with respect to +/- patch repair.

RESULTS

Of 70 survivors, 61 (87%) were enrolled and prospectively evaluated in follow-up. Poorer auxological outcome, increased rate of gastroesophageal reflux, and altered pulmonary function test were observed during follow-up.

CONCLUSIONS

Patch repair correlates with higher pulmonary, auxological, and gastroesophageal morbidity without increasing chest wall deformities at long-term follow-up.