Large-scale turbulence structures in a laboratory-scale boundary layer under steady and gusty wind inflows

Experiments on turbulence structures and features of a wind field under steady inflow and gusty wind inflows were implemented in a straight-through wind tunnel. Streamwise and wall-normal velocity components were measured using a streamline constant temperature anemometer (streamline CTA). Power spectra analyses revealed the existence of very large-scale motions (VLSMs) under both steady and gusty wind inflows; but new gusty scale motions (GSMs) were revealed under only gusty wind inflows. The GSMs might originate from an ordered external driving force that forces hairpin packets to align coherently in groups with a length scale related to the gust inflow condition. The streamwise wavelength of VLSMs is independent of inflow conditions, while the turbulent energy of VLSMs is associated with the wall-normal height and local mean streamwise velocity. In particular, the streamwise wavelength of GSMs increases linearly with the average value and period of sinusoidal gusty wind inflows, and the turbulent energy of GSMs is sensitive to the wall-normal height and all characteristic parameters of gusty wind inflows, including the average value, amplitude and period. Considerable wall-normal airflows induced by gusty wind inflows were detected and these are negatively correlated with the variation in gusty streamwise velocity, and root mean square (RMS) values of the gusty wall-normal velocity tended to increase linearly with the average value and amplitude of gusty wind inflows.

Identification of a missense mutation of c.3064G>A, Gly1022Ser in exon 43 of COL1A1 gene in a girl with osteogenesis imperfecta type III

Osteogenesis imperfecta (OI) types I-V have been inherited in an autosomal dominant pattern. OI type I is associated with mutations in COL1A1 mostly due to a null allele. OI types II-IV are associated with mutations in COL1A1 or COL1A2 and mostly are due to glycine substitutions. It has been suggested that the effect of glycine substitutions is position specific, and the substitution of glycine by serine has much less lethal effect than the substitutions by valine, aspartic acid, glutamic acid, arginine and cysteine. We report identification of c.3064G>A, GGT>AGT, Gly1022Ser (Gly(844) --> Ser844 in triple helix) in exon 43 of the COL1A1 gene in an 8-year-old girl with OI type III. Our report provides evidence that at triple helix glycine residue 844 (p.Gly1022), a glycine substitution by serine can result in OI type III but not a lethal outcome.

Partial monosomy 3p (3p26.2 --> pter) and partial trisomy 5q (5q34 --> qter) in a girl with coarctation of the aorta, congenital heart defects, short stature, microcephaly and developmental delay

A 1-year-and-3-month-old girl presented with psychomotor retardation, developmental delay, clinodactyly of the thumb, coarctation of the aorta, patent ductus arteriosus, peripheral pulmonary stenosis, atrial septal defect, microcephaly, brachycephaly, a small oval face, almond-shaped eyes, a down-turned mouth, a widened nasal bridge, hypertelorism, epicanthic folds, long philtrum, low-set large ears and but no craniosynostosis. Oligonucleotide-based array comparative genomic hybridization revealed a -4.79-Mb deletion of 3p26.2 --> pter encompassing CHL1 and CNTN4, and a -19.56-Mb duplication of 5q34 --> qter encompassing MSX2, NKX2-5 and NSD1. The karyotype of the girl was 46,XX,der(3)t(3;5)(p26.2;q34) pat. The present case adds distal 5q duplication to the list of chromosome aberrations associated with coarctation of the aorta.

Increased risk of cardiovascular disease in Type 1 diabetes: arterial exposure to remnant lipoproteins leads to enhanced deposition of cholesterol and binding to glycated extracellular matrix proteoglycans

AIMS

To determine fasting and postprandial metabolism of apolipoprotein B48 (apoB48) remnant lipoproteins in subjects with Type 1 diabetes and the relationship to progressive cardiovascular disease, and to investigate the impact of remnant lipoprotein cholesterol accumulation associated with arterial wall biglycan using a rodent model of Type 1 diabetes.

METHODS

Normolipidaemic subjects (n = 9) with long-standing Type 1 diabetes (and advanced cardiovascular disease) and seven healthy control subjects were studied. Fasting and postprandial apoB48 concentration was determined following a sequential meal challenge. A rodent model of streptozotocin-induced diabetes was used to investigate the ex vivo retention of fluorescent-conjugated remnants. Binding of remnant lipoproteins to human recombinant biglycan was assessed in vitro.

RESULTS

A significantly higher concentration of fasting plasma apoB48 remnants was observed in patients with Type 1 diabetes compared with control subjects. Patients with Type 1 diabetes exhibited a greater total plasma apoB48 area under the curve (AUC) and an increased incremental AUC following a second sequential meal compared with control subjects. The arterial retention of remnants ex vivo and associated cholesterol was increased sevenfold in Type 1 diabetes rats relative to controls. Remnants were shown to bind with significant affinity to human biglycan in vitro and a further 2.3-fold increased binding capacity was observed with glycated biglycan. Remnants were shown to colocalize with both arterial biglycan and glycated matrix proteins in the Type 1 diabetes rodent model.

CONCLUSION

Impaired metabolism of remnant lipoproteins associated with enhanced binding to proteoglycans appears to contribute to the arterial cholesterol deposition in Type 1 diabetes. Our findings support the hypothesis that impaired remnant metabolism may contribute to accelerated progression of atherosclerosis in the hyperglycaemic and insulin-deficient state.

Open window thoracostomy: modern update of an ancient operation

INTRODUCTION

In modern day thoracic surgical practice, better understanding of the pathophysiology of intrathoracic infections, improved antibiotic therapy and advancements in thoracic surgical techniques have decreased the use of procedures such as open window thoracostomy (OWT). Despite this, there are occasions where OWT cannot be avoided, and it is of interest where its current utility lies. To determine the current efficacy of OWT, we reviewed our recent experience with a focus on the indications, timing of surgery, effectiveness in clearing infection, patient survival, and timing of closure.

METHODS

After Institutional Review Board approval, charts of 78 patients were reviewed. Dates reviewed were from 1/1/1998 to 1/1/2008. Patients were predominantly male (66 %) with a median age 58 years. Median time from initial diagnosis to OWT was 70 days (range 1 to 720 days).

RESULTS

Primary indication for surgery was empyema in 75 (96 %), and most patients had previous thoracic surgery. The most frequent causes of empyema were post-pneumonectomy (n = 25), post-pneumonic (n = 14), and post-lobectomy (n = 9). Bronchopleural fistulae were present in 29 (37 %) cases. Lung cancer was diagnosed in 34 (45 %) patients, and 24 underwent perioperative radiation therapy. Patient survival at 1 month, 6 months, 1 year and 5 years was 94 %, 82 %, 74 % and 60 %, respectively, with an in-hospital mortality of 6.4 %. Infection was controlled in nearly all patients (n = 72). Fifteen (19 %) patients underwent surgical closure for OWT; in 2 (2.6 %), OWT closed spontaneously.

CONCLUSIONS

Currently, open window thoracostomy is used to treat complex empyema incurred from pulmonary resection, cancer and/or infection in patients that cannot be managed by more conservative strategies. Overall mortality and morbidity rates are acceptable in this debilitated patient group.

Methods to assess impaired post-prandial metabolism and the impact for early detection of cardiovascular disease risk

Post-prandial lipaemia has emerged as a key contributor to cardiovascular disease (CVD) risk and progression. Specifically, delayed clearance of chylomicrons (CM) and their remnants increase the delivery of triglyceride and cholesteryl ester to the vessel wall and can accelerate the progression of atherosclerosis, which may be particularly pertinent to individuals with insulin resistance and/or obesity. As the number of studies linking post-prandial metabolism and chronic disease increases, interest has grown in the use of parameters reflecting CM metabolism as a possible indicator of early CVD risk. This, in turn has raised the question of what method might be most appropriate to detect CM and their remnants in plasma accurately. However, the handful of techniques able to measure CM metabolism (triglyceride-rich lipoprotein fractions; remnant-lipoprotein cholesterol; retinyl esters, CM-like emulsion; sodium dodecyl sulphate-polyacrylamide gel electrophoresis; immunoblotting, enzyme-linked immunoabsorbent assays; C(13) breath test; capillary finger prick) differ in their specificity, cost and applicability in research and in the clinical setting. In this review, we explore the scientific and clinical implications of CM methodology to better understand early risk assessment of CVD. We raise ongoing issues of the need to appreciate differential separation of very low-density lipoprotein and CM fractions, as well as to identify the technical basis for imprecision between assays for apolipoprotein B48. We also highlight emerging issues with respect to the practicality of measuring post-prandial metabolism in large clinical studies and offer opinions on the appropriateness of existing techniques in this field.

Cogan's syndrome with recurrent carotid and aortic aneurysms: a potentially fatal disorder mimicking Marfan syndrome

Cogan's syndrome (CS) is a rare multisystemic disease characterized by vestibuloauditory dysfunction, inflammatory eye disease and vasculitis. Aortic aneurysms due to aortitis are under-recognized in CS, and are potentially fatal, with two of eight reported cases dying from aneurysm/arterial rupture. The presence of aneurysms was not recognized antemortem in both cases, highlighting the importance of early detection to prevent this potentially fatal outcome. We report a 17-year-old Chinese male with recurrent carotid and aortic aneurysms, bilateral sensorineural hearing loss, and recurrent scleritis who was initially thought to have Marfan syndrome. The diagnosis of CS was made 4.5 years after initial presentation, during which time recurrent aneurysms due to active aortitis (with aneurysmal rupture on one occasion) necessitated four surgical procedures. Treatment with methotrexate and corticosteroids resulted in no recurrence of aneurysms over 2 years of follow-up. This case illustrates (i) the challenges in diagnosing CS when various manifestations occur separately over a relatively long time period, (ii) that detection of aortic aneurysms in young patients, especially if recurrent, should prompt investigations for vasculitis/aortitis to prevent potentially fatal aneurysm rupture, and (iii) that methotrexate and high-dose corticosteroids may be effective in preventing development of further aneurysms in CS patients.

Resection of a giant malignant mediastinal peripheral nerve sheath tumour under cardiopulmonary bypass

Malignant peripheral nerve sheath tumour (MPNST) is a rare occurrence in the mediastinum. It is biologically aggressive and is generally resistant to chemoradiation therapy. The mainstay of treatment is complete surgical resection. We report a large MPNST which invaded into the adjacent aortic wall in a 50-year-old man. Extensive resection, which included aortic reconstruction under cardiopulmonary bypass and deep hypothermic arrest, was necessary for a good long-term outcome.

Bilateral pneumothoraces as a complication of acupuncture

Pneumothorax developing secondary to acupuncture is rare. However, in an undiagnosed case, it may cause fatality. The real incidence of acupuncture-related pneumothorax is not known but is acknowledged to be underdiagnosed and under-reported. We describe pneumothorax occurring in a 52-year-old woman who developed bilateral pneumothoraces, with one side being a tension pneumothorax, immediately following acupuncture. The needle was inserted at a paravertebral point at the level of the third vertebral spinous process.

[Clinical study on effect of sini decoction on ischemia/reperfusion injury by Holter monitoring in patients with acute myocardial infarction treated with thrombolytic therapy]

OBJECTIVE

To observe the clinical effect of Sini Decoction (SND) on ischemia/reperfusion injury in acute myocardial infarction (AMI).

METHODS

Randomized case-control clinical trial was conducted to observe the change of Holter monitoring in 22 cases of AMI treated with thrombolytic therapy before and after treatment.

RESULTS

The lasting time of acute ST segment, total burden of myocardial infarction, QRS score, QT dispersion and occurrence of reperfusion arrhythmia in patients received SND treatment were lower than those untreated with SND (P < 0.05).

CONCLUSION

SND is helpful in improving reperfusion injury of thrombolytic therapy in AMI patients.

Evaluation of germ-cell kinetics in infertile patients with proliferating cell nuclear antigen proliferating index

AIM

To explore the usefulness of proliferating cell nuclear antigen proliferating index (PCNA PI) in the pathological diagnosis and treatment of male infertility.

METHODS

Testicular biopsy specimen obtained from 48 cases of male infertility and 2 normal controls were fixed and embedded. The sections were stained with anti-PCNA monoclonal antibodies or haematoxylin/eosin. Proliferating index (PI), expressed as the percentage of germ-cell nuclei positively stained with PCNA antibody, was assessed from more than 20 seminiferous tubules or 600 germ-cells.

RESULTS

The infertile patients were divided into 4 groups: Group 1, normal spermatogenesis (14 cases); Group 2, hypospermatogenesis (16 cases); Group 3, germinal arrest (10 cases); Group 4, Sertoli cell only syndrome (8 cases). The PCNA PI of normal control testis was 86.5% (mean value). Group 3 had a significantly lower PCNA PI (29.8%) than normal testis; Group 1 and 2 had similar PIs (82.3% and 82.3%, respectively) as the control testis. PI of the negative control (Group 4) was 0 as no germ-cells were found.

CONCLUSION

PCNA PI is useful for assessing germ-cell kinetics, especially for pathological diagnosis of germinal arrest which is difficult to differentiate by routine HE staining technique. In germinal arrest, there is a significantly lowered PCNA PI, which is an indication of DNA synthesis deterioration, suggesting the use of therapies be different from those for hypospermatogenesis.

A prospective evaluation of surgeon performed sonography as a screening test in blunt abdominal trauma

INTRODUCTION

Sonography has found a role in the evaluation of patients with abdominal injury. However, the accuracy of sonography as performed by non-radiologists remains controversial. This study aims to determine the accuracy of focused abdominal sonography for trauma when performed by surgeons.

MATERIALS AND METHOD

Over a 1-year period, 48 patients with abdominal injury were initially evaluated for free intraperitoneal fluid by sonography. These tests were performed by 2 surgeons who had received instructions and performed a minimum of 30 examinations. Sonographic findings were then compared with other diagnostic modalities including computed tomography (CT) scan, diagnostic peritoneal lavage and exploratory laparotomy.

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value and accuracy for sonography were found to be 0.86, 0.92, 0.89, 0.90 and 0.89, respectively. Although not specifically sought for, 2 cases of solid organ injury and 1 haemothorax, which were missed in initial examinations and X-rays, were detected on sonography.

CONCLUSION

In conclusion, our initial experience suggests that local surgeons can perform a focused sonographic examination for trauma with acceptable accuracy. Although sonography lacks the sensitivity of diagnostic peritoneal lavage and the accuracy of CT scan, the diagnostic algorithm for abdominal trauma should include sonography as a screening test.

Repair of cardiac defects through a shorter right lateral thoracotomy in children

BACKGROUND

Median sternotomy is a conventional approach for correction of cardiac defects for many years; however, the cosmetic result is poor. Therefore, right lateral thoracotomy was tested as an alternative procedure with a better cosmetic outcome.

METHODS

Between October 1994 and February 1999, 683 patients underwent correction of congenital cardiac malformations during a cardiopulmonary bypass through right lateral thoracotomy involving a shorter incision through the third or the fourth intercostal space. All of the patients were children. The average age was 3.26+/-1.67 years (range, 4 months to 7 years). The average weight was 13.59+/-4.37 kg (5 to 40). The patients had various cardiac defects and associated anomalies.

RESULTS

Only 2 patients died after operation, 1 from low cardiac output and the other from severe pulmonary infection. The hospital morbidity was lower. The mean cardiopulmonary bypass time was 58.67+/-35.11 minutes (range, 16 to 430 minutes), the mean aortic cross-clamping time was 35.03+/-24.84 minutes (range, 3 to 205 minutes). The postoperative average mechanical ventilation time was 19.23+/-39.11 hours (range, 2 to 391 hours), and the mean postoperative stay was 8.55+/-12.54 days (range, 5 to 293 days).

CONCLUSIONS

The right lateral thoracotomy incision is a safe and effective alternative to a median sternotomy for correction of cardiac defects. Advantages of this approach compared with median sternotomy are less injury, maintenance of the continuity and the integrity of the bony thorax, and prevention of the development of "pigeon-chesting." The scar is less visible, hence, the cosmetic result can meet patient expectations. This procedure is consistent with the idea of minimal invasive surgery.

[Improvement of sini decoction on hemorheology following percutaneous transluminal coronary angioplasty]

OBJECTIVE

To study the hemorheological effects of Sini decoction on patients following percutaneous transluminal coronary angioplasty (PTCA).

METHODS

Forty-six patients were randomly divided into Sini decoction and control groups. The hemorheologic variables were determined before and after Sini decoction treatment.

RESULTS

No hemorheologic changes were observed in the patients (n = 23) only with PTCA, but the patients (n = 23) with Sini decoction were found to be significantly decreased in whole blood viscosity and red cell aggregation and dredging the blood of microcirculation as post-PTCA compared to pre-PTCA.

CONCLUSION

Sini decoction could improve the patient's hemorheology.

Intercellular communication is cell cycle modulated during early Xenopus laevis development

We investigated intercellular communication during the seventh and tenth cell cycles of Xenopus laevis development using microinjection of Lucifer yellow and FITC-dextran as well as freeze-fracture electron microscopy. We found that gap junction-mediated dye coupling visualized using Lucifer yellow was strongly cell cycle modulated in the tenth cell cycle. Cytoplasmic bridge-mediated dye coupling visualized via FITC-dextran was also, of course, cell cycle modulated. The basis of cell cycle-modulated gap junctional coupling was investigated by measuring the abundance of morphologically detectable gap junctions through the tenth cell cycle. These proved to be six times more abundant at the beginning than at the end of this cell cycle.