This study shows that, over time, diaphragm inactivity with controlled mechanical ventilation (CMV) decreases diaphragm force and produces myofibril damage contributing to the reduced force. We mea...

Altered diaphragm contractile properties with controlled mechanical ventilation

OBJECTIVE. Risk assessment based on plaque vulnerability would be valuable in the management of asymptomatic carotid stenosis. The purpose of this study was to compare plaque morphology in symptomatic and asymptomatic patients with significant extracranial carotid artery stenosis using MDCT angiography.MATERIALS AND METHODS. We identified 31 patients with greater than 60% carotid artery stenosis on MDCT angiography using the criteria of the North American Symptomatic Carotid Endarterectomy Trial Collaborators. We analyzed plaque density by blinded review in Hounsfield units in the atherosclerotic plaques of 15 symptomatic and 21 asymptomatic stenotic vessels for classification as soft, intermediate, or calcified. Data were analyzed using multiple logistic regression.RESULTS. Even with age, traditional cardiovascular risk factors, and treatment taken into account, we found that calcified plaques were 21 times less likely to be symptomatic than noncalcified plaques (95% confidence interval for odds ratio, 0...

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Calcified Carotid Atherosclerotic Plaque Is Associated Less with Ischemic Symptoms Than Is Noncalcified Plaque on MDCT

Severe high-altitude hypoxia exposure is considered a triggering stimulus for redox disturbances at distinct levels of cellular organization. The effect of an in vivo acute and severe hypobaric hypoxic insult (48 h at a pressure equivalent to 8,500 m) on oxidative damage and respiratory function was analyzed in skeletal muscle mitochondria isolated from vitamin E-supplemented (60 mg/kg ip, 3 times/wk for 3 wk) and nonsupplemented mice. Forty male mice were randomly divided into four groups: control + placebo, hypoxia + placebo (H + P), control + vitamin E, and hypoxia + vitamin E. Significant increases in mitochondrial heat shock protein 60 expression and protein carbonyls group levels and decreases in aconitase activity and sulfhydryl group content were found in the H + P group when compared with the control + placebo group. Mitochondrial respiration was significantly impaired in animals from the H + P group, as demonstrated by decreased state 3 respiratory control ratio and ADP-to-oxygen ratio and by increased state 4 with both complex I- and II-linked substrates. Using malate + pyruvate as substrates, hypoxia decreased the respiratory rate in the presence of carbonyl cyanide m-chlorophenylhydrazone and also stimulated oligomycin-inhibited respiration. However, vitamin E treatment attenuated the effect of hypoxia on the mitochondrial levels of heat shock protein 60 and markers of oxidative stress. Vitamin E was also able to prevent most mitochondrial alterations induced by hypobaric hypoxia. In conclusion, hypobaric hypoxia increases mitochondrial oxidative stress while decreasing mitochondrial capacity for oxidative phosphorylation. Vitamin E was an effective preventive agent, which further supports the oxidative character of mitochondrial dysfunction induced by hypoxia.

https://www.physiology.org/doi/pdf/10.1152/japplphysiol.01324.2004

Acute and severe hypobaric hypoxia increases oxidative stress and impairs mitochondrial function in mouse skeletal muscle

From 1947 through 1992, 37 Mayo Clinic patients underwent operation for the relief of tracheoesophageal obstruction that resulted from vascular rings and related entities. Of the 37 patients, 18 had a double aortic arch, 11 had a right aortic arch with an aberrant left subclavian artery, 4 had a left aortic arch with an aberrant right subclavian artery, 2 had a pulmonary artery sling, 1 had a right aortic arch with mirror-image branching and a left ligamentum arteriosum, and 1 had a left aortic arch, a right descending aorta, and a right ductus arteriosus. Symptoms consisted of stridor, recurrent respiratory infections, and dysphagia. The anomaly was approached through a left thoracotomy in 31 patients, through a right thoracotomy in 4, and through a median sternotomy in 2. Only one early postoperative death (3%) and no late deaths occurred. At long-term follow-up (maximal duration, 45 years), three patients had residual symptomatic tracheomalacia, one of whom required right middle and lower lobectomy for recurrent pneumonia. Magnetic resonance imaging is the imaging technique of choice for accurate delineation of the vascular and tracheal anatomy. When patients are symptomatic, vascular ring should be repaired. The surgical risk is minimal, and the long-term results are excellent.

https://www.mayoclinicproceedings.org/article/S0025-6196(12)60898-2/pdf

Surgical Treatment of Vascular Rings: The Mayo Clinic Experience

Kommerell's diverticulum is a developmental error with a remnant of fourth dorsal aortic arch, named after Dr. Kommerell, a radiologist, who made the first diagnosis in a living individual. The diverticulum can occur in both the left and right aortic arch, from which an aberrant subclavian artery rises to the contralateral side. Pediatric patients often present with airway symptoms whereas dysphagia and chest discomfort are more common in the adult patients. Computed tomography or magnetic resonance imaging can provide details of the diverticulum, associated arch anomalies, and its relationship with surrounding organs. Recent histological studies indicated the presence of cystic medial necrosis in the diverticulum wall, which would explain the reported high rates of aortic dissection and rupture associated with the diverticulum. Accumulated knowledge on this entity and the recent advancement of imaging techniques, surgical/endovascular strategies, and perioperative management, have led to more aggressive intervention to the diverticulum in the early phase. While still under debate it is generally accepted to consider surgical intervention when the diameter of the diverticulum orifice exceeds over 30 mm, and/or the diameter of the descending aorta adjacent to the diverticulum exceeds over 50 mm. Treatment options include open surgical repair, hybrid endovascular repair, and total endovascular repair. The selection of treatment strategy for Kommerell's diverticulum should be based on the anatomy, comorbidities of the patient, and surgical expertise available. The summaries of open and endovascular repairs of over 210 cases from literature search from 2004 to 2014 are also provided in this review.

Kommerell's diverticulum in the current era: a comprehensive review.

Indicators of oxidative injury and alterations of the cell membrane in the skeletal muscle of rats submitted to ischemia and reperfusion.

Two cases of this anomaly, in women (26 and 49 years old), with symptoms of short duration (4 and 3 months) of dysphagia, regurgitation and esophagitis, without loss of weight, are presented. In both, the final diagnosis was made by mean of thoracic aortogram. Esophagoscopy realized only in the first patient, demonstrated the pulsatile esophageal compression. The first patient was operated on through a right cervical incision, made in the anterior border of the sternomastoid muscle. In the second, a partial sternotomy, combined with a right supraclavicular prolongation, was used. In both, the anomalous artery was taken from the aorta and behind the esophagus, and anastomosed to the right common carotid artery. The dysphagia disappeared in the second case, but persisted attenuated, in the first one. Manometric studies realized in the 3rd and 18th months postoperatively demonstrated an aperistaltic segment of the esophagus (between 4 and 7 cm from the superior sphincter).

Surgical treatment of dysphagia lusória

Background
To establish the correlation between quantitative analysis based on B-mode ultrasound images of vulnerable carotid plaque and histological examination of the surgically removed plaque, on the basis of a videodensitometric digital texture characterization.

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Ultrasonic tissue characterization of vulnerable carotid plaque: correlation between videodensitometric method and histological examination

Mitochondrial alterations in skeletal muscle submitted to total ischemia.

Tratamentos como hemodialise, quimioterapia, transplante de medula ossea, nutricao parenteral necessitam cada vez mais de acessos venosos de longa duracao. O objetivo deste trabalho foi analisar, retrospectivamente atraves dos prontuarios, as complicacoes imediatas e tardias de 66 implantes venosos centrais realizados em 59 pacientes no HCRP-USP, no periodo de junho de 1997 ate dezembro de 1998. Dos 66 cateteres implantados 37 foram do tipo Broviac-Hickman (BH) e 29 do tipo totalmente implantavel (TI). Complicacoes precoces: 1 caso de sangramento. Complicacoes tardias: 29 casos de infeccao do cateter (sendo 21 em BH), 8 casos de oclusao (sendo 5 em TI), 3 casos de infeccao da ferida cirurgica (2 no BH), 1 caso de obito relacionado com o cateter (1 no TI, sepse). O numero de complicacoes precoces foram minimos. Tardiamente os indices de oclusao sao semelhantes aos encontrados na literatura enquanto que a incidencia de infeccao destes implantes sao superiores aos publicados na literatura, indicando a necessidade de maiores cuidados de assepsia na manipulacao do cateter pela equipe medica paramedica e do proprio paciente.

Jesualdo Cherri

Papers

Indicators of oxidative injury and alterations of the cell membrane in the skeletal muscle of rats submitted to ischemia and reperfusion.

Surgical treatment of dysphagia lusória

Ultrasonic tissue characterization of vulnerable carotid plaque: correlation between videodensitometric method and histological examination

Mitochondrial alterations in skeletal muscle submitted to total ischemia.

Complicações precoces e tardias em acesso venoso central. Análise de 66 implantes