Thoracic endometriosis with a long delay in diagnosis

This paper describes a case of thoracic endometriosis in 36-year-old woman with a long delay in diagnosis. At the admission in the hospital, the patient had a medical history of persistent dysmenorrhea since the age of 13, infertility and an episode of total right pneumothorax two months ago successfully resolved by minimum pleurotomy of the right hemitorax. She came with moderate pain on right hemithorax and dyspnea, which occurred on the first day of menstruation but she did not have any other respiratory symptoms such as hemoptysis, cough. Radiological imaging (chest radiography and computer tomography) at the time of admission confirmed recurrence of the right pneumothorax. She underwent surgical treatment of the right pneumothorax using a single-port video-assisted approach. Intraoperative macroscopic lesions were found catamenial pneumothorax characteristic diagnosis and biopsy material taken (parietal pleura) for histopathology. Immuno-histochemical tests confirmed the diagnosis of thoracic endometriosis. The gonadotropin-releasing hormone analogue was received by the patient early after surgery and there was no clinical or radiological recurrence at a four months follow-up.

Defects in mitochondrial ATP synthesis in dystrophin-deficient mdx skeletal muscles may be caused by complex I insufficiency

Duchenne Muscular Dystrophy is a chronic, progressive and ultimately fatal skeletal muscle wasting disease characterised by sarcolemmal fragility and intracellular Ca2+ dysregulation secondary to the absence of dystrophin. Mounting literature also suggests that the dysfunction of key energy systems within the muscle may contribute to pathological muscle wasting by reducing ATP availability to Ca2+ regulation and fibre regeneration. No study to date has biochemically quantified and contrasted mitochondrial ATP production capacity by dystrophic mitochondria isolated from their pathophysiological environment such to determine whether mitochondria are indeed capable of meeting this heightened cellular ATP demand, or examined the effects of an increasing extramitochondrial Ca2+ environment. Using isolated mitochondria from the diaphragm and tibialis anterior of 12 week-old dystrophin-deficient mdx and healthy control mice (C57BL10/ScSn) we have demonstrated severely depressed Complex I-mediated mitochondrial ATP production rate in mdx mitochondria that occurs irrespective of the macronutrient-derivative substrate combination fed into the Kreb's cycle, and, which is partially, but significantly, ameliorated by inhibition of Complex I with rotenone and stimulation of Complex II-mediated ATP-production with succinate. There was no difference in the MAPR response of mdx mitochondria to increasing extramitochondrial Ca2+ load in comparison to controls, and 400 nM extramitochondrial Ca2+ was generally shown to be inhibitory to MAPR in both groups. Our data suggests that DMD pathology is exacerbated by a Complex I deficiency, which may contribute in part to the severe reductions in ATP production previously observed in dystrophic skeletal muscle.

[Diaphragmatic bronchogenic cyst: an exceptional location]

A 64-year-old man complained of persistent dyspnea and bilateral basi-thoracic pain with shoulder irradiation. Chest computed tomography revealed a heterogeneous left diaphragmatic mass, while magnetic resonance imaging showed hypo-T1 and hyper-T2 signal. Positron-emission tomography did not show any hypermetabolism. Video-assisted thoracic surgery was decided. At inspection, tumour appeared within the posterior costal part of the diaphragmatic muscle. Tumour resection was extended to a 8-cm-long portion of the lumbar part of diaphragm. Diaphragm was repaired with non-absorbable interrupted sutures. Postoperative course was uneventful. Final pathology revealed an intra-diaphragmatic bronchogenic cyst, which is an exceptional condition. Primary diaphragmatic tumours are very rare and preoperative diagnosis cannot be affirmed. Embryologic hypotheses (migration along the oesophagus or envelopment within diaphragmatic precursors of an abnormal supernumerary lung bud) including recent molecular findings of deregulated pathways (fibroblast growth factor-10 and NOTCH) are discussed.

Inclusion body myositis masquerading as cardiac dyspnea

Dyspnea in the elderly can be due to a wide array of pathologies. We discuss a case of an elderly gentleman with an extensive cardiovascular history presenting with acute worsening of chronic dyspnea. Because of persistent respiratory distress unresponsive to standard therapy for congestive heart failure, chronotropic insufficiency, and pulmonary hypertension, further evaluation was undertaken which revealed that diaphragmatic weakness was the etiology of his respiratory failure. EMG and muscle biopsy confirmed the diagnosis of inclusion body myositis (IBM).

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.