Coupling Different Periodic Building Units for Intergrowth Zeolites.

Multiple-phase disordered zeolites, i.e., intergrowth zeolites, are important industrial catalysts, like single-phase ordered zeolites, but little is known about their rational synthesis and phase competition, mainly due to current poor understanding of the zeolite crystallization mechanism. Here, we theoretically demonstrated that sodalite and cancrinite cage layers, the periodic building units (PerBUs) of FAU/EMT and SBT/SBS structures, respectively, could be nondefectively connected to each other across double rings of 6 tetrahedral atoms when inverted and mirrored. We then synthesized an unprecedented family of FAU/SBT/SBS intergrowths with controllable FAU portions (named as the PST-34 family of intergrowth zeolites) using a multiple inorganic cation approach, providing clear experimental evidence for the layer-by-layer crystal growth mechanism of zeolites. This study shows that control of interactive cooperation extent between different inorganic structure-directing agents in the presence of an unselective organic structure-directing agent may enable repeated stacking of different but structurally related PerBUs in intergrowth zeolite synthesis.

Pediatric deep venous thrombosis associated with Staphylococcus aureus osteomyelitis.

INTRODUCTION: Our objective was to evaluate clinical features of children with deep venous thrombosis (DVT) and acute hematogenous osteomyelitis (AHO) caused by Staphylococcus aureus. METHODOLOGY: We analyzed 4 years of medical records of patients with AHO and DVT caused by Staphylococcus aureus (S. aureus) and compared clinical and biochemical characteristics of AHO with and without DVT, as well as patients whose DVT dissolved in ≥ 3 weeks. RESULTS: DVT was found in 19/87 AHO individuals (22%). The median age was 9 years (range: 0.5-15 years). 74% (14/19) patients were boys. Methicillin-susceptible Staphylococcus aureus (MSSA) was present in 58% (11/19) cases. The femoral vein and common femoral vein were the two most damaged veins (9 cases each). Anticoagulation therapy with low molecular weight heparin was given to 18 (95%) patients. Within 3 weeks of anticoagulation, 7/13 (54%) with available data had completely resolved DVT. There was no rehospitalization due to bleeding or recurrent DVT. Patients with DVT were found to be older and had increased levels of C-reactive protein, procalcitonin, D-dimer, positive blood culture, incidence of intensive care unit admission, multifocal rate, and length of hospital stay. We did not find clinical difference between patients whose DVT dissolved within 3 weeks and those with > 3 weeks. CONCLUSIONS: Over 20% of patients with S. aureus AHO developed DVT. MSSA accounted for more than half of the cases. DVT was completely resolved in more than half of the cases after 3 weeks of anticoagulant medication, with no sequelae.

Synthesis and Crystal Growth Mechanism of PST-2: An Aluminosilicate SBS/SBT Zeolite Intergrowth.

The synthesis of PST-2, an aluminosilicate zeolite intergrowth of cage-based, large-pore SBS and SBT topologies, and its intergrowth characteristics are presented. With the Si/Al ratio and crystallization inorganic structure-directing agent in zeolite synthesis mixtures fixed to 8.0 and Cs+ ions, respectively, pure PST-2 is obtained at 120 °C using tetraalkylammonium ions with C/N+ ratios of 5-9 as a charge density mismatch (CDM) organic structure-directing agent (OSDA). More interestingly, the intergrowth ratio between SBS and SBT in PST-2 was found to vary notably not only with the type of CDM OSDA employed but also with the crystallization time, unlike the case of other well-known zeolite intergrowths such as ß and MFI/MEL. When tetraethylammonium ions are used as a CDM OSDA at 100 °C in the presence of Cs+, the SBS portion in PST-2 decreases from over 60% to less than 45% with increasing crystallization time from 2.5 to 14 days, suggesting that SBS formation is kinetically more favorable than SBT formation. A thorough characterization of changes in the crystallite dimension of PST-2 with crystallization time, together with those in the chemical composition, allowed us to propose a plausible crystal growth mechanism of this large-pore zeolite intergrowth.

Red-Emissive Sulfur-Doped Carbon Dots for Selective and Sensitive Detection of Mercury (II) Ion and Glutathione.

Carbon dots (CDs) show great potential in bioimaging and biosensing because of their good biocompatibility and excellent optical properties. However, CDs with intense red emissions for sensitive and selective detection are rarely reported. Herein, we prepared the red-emissive carbon dots (RCDs) through a facile hydrothermal method using tetra (4-carboxyphenyl) porphyrin (TCPP) and thiourea as starting materials. The obtained RCDs were characterized by TEM, XRD, and XPS. RCDs exhibited high water solubility and strong red emission (λem = 650 nm), with the fluorescence quantum yield as high as 26.7%, which was greatly higher than that of TCPP. Moreover, the as-prepared RCDs could be acted as a highly selective and sensitive probe for the detection of Hg2+ and glutathione (GSH) through the fluorometric titration method. The detection limits of Hg2+ and GSH were calculated to be 1.73 and 1.6 nM, respectively. The cellular experiments demonstrated the good biocompatibility of RCDs and their feasibility in bioimaging. Thus, this work provided a simple strategy to design and synthesize the highly red-emissive carbon dots, which showed promising application in biological and environmental assays.

Cobalt-Doped Carbon Quantum Dots with Peroxidase-Mimetic Activity for Ascorbic Acid Detection through Both Fluorometric and Colorimetric Methods.

In this work, we fabricated cobalt-doped carbon quantum dots (Co-CQDs) by a one-pot hydrothermal method with cobalt tetraphenylporphyrin and 1,2-ethanediamine as precursors. The morphology and structure of the Co-CQDs were characterized through transmission electron microscopy, X-ray diffraction spectra, Fourier transform infrared, and X-ray photoelectron spectra. The Co-CQDs emitted intense blue luminescence under ultraviolet irradiation and exhibited a typical excitation-dependent emission property. Moreover, they can act as a fluorescent probe for the detection of Fe3+ and ascorbic acid (AA) with high selectivity and sensitivity through an "on-off-on" mode. The limit of detection (LOD) of Fe3+ was measured as 38 µM (S/N = 3). The quenched emission of carbon quantum dots can be recovered with the addition of ascorbic acid (AA) to the Co-CQDs/Fe3+ system. The change of fluorescence was linear with the concentration of AA (0.6-1.6 mM) with the LOD of 18 µM. Furthermore, the Co-CQDs exhibited high oxidase-like catalytic behavior, which could convert transparent 3,3',5,5'-tetramethylbenzidine (TMB) into blue ox-TMB by dissolved oxygen. After adding ascorbic acid to the Co-CQDs/TMB system, the blue color of the solution faded due to the reduction of blue ox-TMB to colorless TMB. Based on this phenomenon, the Co-CQDs were capable of detecting AA (10-400 µM) with the LOD of 0.27 µM. The fluorometric and colorimetric assays based on the Co-CQDs for the AA detection were then successfully applied in fresh fruits. Furthermore, the high biocompatibility of the Co-CQDs against HeLa cells was verified by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Thus, the Co-CQDs could be used as a powerful tool for the detection of AA in real samples through a dual-mode method.

Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) influences adipocytes injuries through triggering XBP1 and activating mitochondria-mediated apoptosis.

Obesity is an important public-health problem worldwide. This study aimed to determine effects of porphyromonas gingivalis lipopolysaccharide (Pg-LPS) on adipocytes injuries and explore associated mechanisms. Adipocytes were isolated from SD rats. pLVX-XBP1 (XBP1 over-expression) and pLVX-XBP1-RNAi (silencing XBP1) were structured and transfected into adipocytes. All adipocytes were divided into pLVX-NC, pLVX-XBP1, pLVX-NC+Pg-LPS and pLVX-XBP1+ Pg-LPS group. Oil-Red O staining was employed to identify isolated adipocytes. Quantitative real-time PCR (qRT-PCR) was used to examine gene transcription of IL-6, TNF-α, leptin, adiponectin. Western blotting was used to detect Bax and caspase-3 expression. Adipocytes were successfully isolated and identified with Oil-Red O staining. Both XBP1 mimic and XBP1 RNAi were effectively transfected into adipocytes with higher expressing efficacy. XBP1 over-expression significantly aggravated Pg-LPS induced inflammatory response compared to adipocytes without Pg-LPS treatment (p<0.05). Pg-LPS significantly enhanced leptin and inhibited adiponectin expression by up-regulating XBP1 expression (p<0.05). XBP1 silence significantly alleviated Pg-LPS induced inflammatory response and reduced leptin, enhanced adiponectin expression in Pg-LPS treated adipocytes compared to adipocytes without Pg-LPS treatment (p<0.05). Pg-LPS induced apoptosis of adipocytes by enhancing XBP1 expression and modulating Bcl-2/Bax pathway associated molecules. In conclusion, Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) induces adipocytes injuries through modulating XBP1 expression and initialling mitochondria-mediated apoptosis.

Eco-friendly and durable PCPS nanoparticles for the effective separation of oil-water emulsions.

Oil pollution is one of the main environmental problems that is attracting increasing attention from people. In this study, a new composite, namely a PNIPAm-Clay-γPGA-SiO2 (PCPS) nanomaterial, was prepared through chemical modification. The material exhibited excellent separation efficiencies for both oil-in-water (O/W) and water-in-oil (W/O) emulsions. The maximum separation efficiency of the W/O emulsion reached 98.70%, while that of the O/W emulsion was 99.23%, and the average separation fluxes were 107.44 L m-2 h-1 and 1529.34 L m-2 h-1, respectively. The superhydrophobicity of the PCPS nanoparticles could be maintained under strong acid/alkali conditions for over 30 days. The high separation efficiency could be maintained even after 7 cycles, indicating the long-term availability of the material. Furthermore, the PCPS nanoparticles showed excellent biocompatibility due to the presence of γ-polyglutamic acid (γPGA) and poly(N-isopropylacrylamide) (PNIPAm). The properties of strong acid/alkali and thermal stabilities, recyclability, and biocompatibility gave the material great potential for applications.

Seawater-enhanced tough agar/poly(N-isopropylacrylamide)/clay hydrogel for anti-adhesion and oil/water separation.

Hydrogels as typical hydrophilic materials are promising candidates for designing novel functional materials for anti-fouling, oil/water separation, wearable devices, tissue scaffolds, etc. However, it still remains a challenge to design stable and tough hydrogels for applications in complex environments of high stress, temperature, salt, and pH. Herein, we fabricate a novel seawater-enhanced Agar/Poly(N-isopropylacrylamide)/clay hydrogel (APNC gel) through a facile photo-initiated polymerization process. The APNC gel consists of fully interpenetrating double networks with negatively-charged clay serving as physical cross-linkers. The resulting gel exhibits tough mechanical strength (tensile strength of 0.85 MPa and compression strength of 1.68 MPa) and excellent stabilities for high temperature (100 °C) and high salt levels (20 wt% NaCl). Especially, the strength of the APNC gel is greatly enhanced (up to 5.04 MPa) by seawater, which contains numerous inorganic ions (Mg2+, Na+, K+, etc.). Meanwhile, the APNC gel presents excellent anti-adhesion performance due to the negatively-charged clay. Thus, a hydrogel-coated mesh with underwater superoleophobicity has been designed for oil/seawater separation. The resulting mesh can selectively remove oil from seawater with high separation efficiency (up to 99%). These characteristics demonstrate that the tough APNC gel will be an ideal material candidate for developing functional materials applied in a complex environment.

Screening chemical modulators of benzoic acid derivatives to improve lipid accumulation in Schizochytrium limacinum SR21 with metabolomics analysis.

BACKGROUND: Schizochytrium sp. is a marine fungus with great potential as an alternative commercial source of lipids rich in polyunsaturated fatty acids (PUFAs). To further increase lipid accumulation in Schizochytrium sp., the effect of exogenous additives has become one of the hotspots of current research. Although benzoic acid derivatives showed positive effects on lipid accumulation in Schizochytrium, the biochemical mechanism needs further investigation. RESULTS: Four benzoic acid derivatives (sodium benzoate, p-aminobenzoic acid, p-methyl benzoic acid and folic acid) were screened and evaluated for their effect on lipid accumulation in Schizochytrium limacinum SR21. The lipid yield was increased by 56.84% with p-aminobenzoic acid (p-ABA) at a concentration of 200 mg/L among the four tested chemical modulators. The metabolomics analysis showed that 200 mg/L p-ABA was optimal for promoting glucose catabolism in glycolysis with an increase in the mevalonate pathway and a weakening of the tricarboxylic acid (TCA) cycle. Moreover, p-ABA increased NADPH generation by enhancing the pentose phosphate pathway (PPP), ultimately redirecting the metabolic flux to lipid synthesis. Fed-batch fermentation further proved that p-ABA could significantly increase the yield of lipid by 30.01%, reaching 99.67 g/L, and the lipid content was increased by 35.03%, reaching 71.12%. More importantly, the yields of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were increased by 33.28% and 42.0%, respectively. CONCLUSION: The addition of p-ABA could promote the synthesis of tetrahydrofolate, enhancing NADPH, which ultimately promoted the flow of carbon flux to lipid synthesis. These findings provide a valuable strategy for improving the lipid accumulation in Schizochytrium by additives.

[Clinical analysis of children with lymphoma complicated with severe pneumonia due to novel influenza A (H1N1) virus infection].

OBJECTIVE: To study the clinical features and treatment of severe pneumonia due to novel influenza A (H1N1) virus in children with lymphoma during chemotherapy. METHOD: The clinical manifestations, radiologic features, reasons of misdiagnosis, experiences in treatment and prognosis of 4 children with lymphoma complicated with pneumonia due to novel influenza A (H1N1) virus during chemotherapy were analyzed retrospectively. RESULT: Four children out of the 54 patients with hematologic disorders who were receiving chemotherapy suffered from H1N1 influenza. Neutrophil counts were less than 0.5 × 10(9)/L in all 4 patients. The body temperature was higher than 39°C accompanied by chill and low blood pressure at the onset of the illness. Dyspnea and hypoxemia occurred quickly. Two of them developed acute respiratory distress syndrome (ARDS). C-reactive protein (CRP) was higher than 50 mg/L in all these cases, and was higher than 200 mg/L in 2 cases. Chest X-ray showed that there were extensive infiltrations in several lung lobes in all the 4 patients. The first patient was misdiagnosed as sepsis at the beginning. The results of 17 blood cultures for the 4 patients were all negative. Fungi were found in 2 of 20 sputum cultures in 2 patients and these 2 patients had been considered as having fungal pneumonias. All the 4 patients were treated with oseltamivir phosphate. The oseltamivir treatment started on the 5(th) day in patient number 1, whereas on the 1(st) day in the other 3 patients. Intravenous immunoglobulin (IVIG) was used in all 4 patients. Methylprednisolone was used in 3 patients. After treatment, 2 died and 2 were improved. CONCLUSION: The children with lymphoma who undergo chemotherapy are prone to develop severe pneumonia during epidemics of influenza A H1N1. The pneumonia may be aggravated very quickly and have a higher mortality. The patients might be easily misdiagnosed as sepsis at early stage. The pneumonia may be misdiagnosed as fungal infection. During H1N1 prevalent season when high fever occurred, H1N1 infection should be considered. Early detection of the virus and use of oseltamivir phosphate and high-dose IVIG and methylprednisolone might reduce the mortality.

Assessment of cystic renal masses in children: comparison of multislice computed tomography and ultrasound imaging using the Bosniak classification system.

To retrospectively compare contrast-enhanced multislice computed tomography (MSCT) and ultrasound (US) imaging for the assessment of cystic renal masses in children using the Bosniak classification system. Twenty-two consecutive patients (age 1 month to 5.2 years, mean 2.4 years) with 24 cystic renal masses (7 benign, 17 malignant) pathologically confirmed after surgical resection underwent both MSCT and US imaging, and were retrospectively analyzed using the Bosniak classification. A senior and a junior radiologist retrospectively and independently reviewed imaging findings. The sensitivity, specificity, positive predictive value and negative predictive values of MSCT and US were assessed using diagnostic statistics. The statistical significance of differences was determined by the McNemar test. Both radiologists accurately predicted lesions of categories I and IV with the Bosniak classification using MSCT and US. All masses classified as Bosniak classes I and II were proven to be benign, and all malignant lesions were correctly characterized in all cases both on ultrasound images and on the contrast-enhanced CT (CECT) images. Two benign multilocular cystic nephromas and one multicystic dysplastic kidney were classified into category III or even IV based on the classification scheme because of their multilocular nature and thick septation. The diagnostic accuracy of CECT was slightly better than ultrasound (CECT vs. US: senior reader, 92% vs. 88%; junior reader, 88% vs. 83%). However, there was no statistically significant difference between the two sets (p>0.05). The two radiologists had perfect inter-observer agreement on the two modalities. Both MSCT and US provide highly accurate diagnosis for the malignant renal cystic masses in children using the Bosniak classification system, but assessment of benign masses still needs improvement. We would recommend US is the best screening modality in Bosniak I and II, In Bosniak III and IV, MSCT are first the choice.

MSCT manifestations with pathologic correlation of abdominal gastrointestinal tract and mesenteric tumor and tumor-like lesions in children: a single center experience.

To study the multi-slice spiral computed tomography (MSCT) manifestations of gastrointestinal tract (GIT) and mesenteric tumor and tumor-like lesions in children and correlation with pathologic findings. 22 patients (17 male, 5 female; age ranged from 3 days to 11 years; with mean of 4.2 years) were screened out by ultrasonography (US) at first, then were performed with abdominal non-enhanced CT (NECT) and contrast-enhanced CT (CECT) scans. All CT images were evaluated independently by two radiologists and a consensus was reached regarding the morphologic features for lesions such as size, solid/cyst, unilocular/multilocular and thin/thick wall characteristics. The 26 lesions were categorized into two groups based on CT characteristics of lesions' nature, group 1 with the prominent cystic lesions, group 2 with prominent solid lesions. Group 1 was further divided into two subgroups: group 1A for the cystic lesions with thin walls, and group 1B for the cystic lesions with thick walls. In group 1A, 7 lesions were unilocular cysts (6 lymphangioma, 1 ileum mesenteric cyst) and 5 were multilocular cysts with internal septation (4 lymphangioma, 1 greater omental cyst). In group 1B, 10 lesions in 7 patients were unilocular without internal septation, which had two kinds of shape-cystic and tubular, their histopathological types were all enteric duplication cyst (10 segments, with two patients with 2 or 3 segments each); In group 2, all lesions had solid mass (2 gastrointestinal stromal tumors and 2 enteric non-Hodgkin's lymphoma). The majority of gastrointestinal tumors and tumor-like lesions are cystic and benign. MSCT manifestations of cystic/solid and thin/thick wall may be great helpful for differentiating different types of GIT and mesenteric lesions. MSCT manifestations have close correlations with their topographic sites and histopathologic findings.

CT characteristics of primary retroperitoneal neoplasms in children.

Primary retroperitoneal neoplasms are uncommon in children. Retroperitoneal neoplasms are either mesodermal, neurogenic, germ cell ectodermal or lymphatic in origin. In general, primary retroperitoneal neoplasms in children have different spectrum and prevalence compared to those in adults. Neuroblastoma, rhabdomyosarcoma, benign teratoma and lymphoma are the common retroperitoneal neoplasms. In this review, the clinical and CT futures of common retroperitoneal neoplasms in children are described. Coarse, amorphous, and mottled calcification are very common in neuroblastoma. Paraganglioma tends to show marked and early enhancement and may present with clinical symptoms associated with the excess catecholamine. Sarcomas are often very large and have heterogeneous appearance. Imaging cannot be reliably used to identify the type of retroperitoneal sarcomas due to overlapped radiographic features. In children, lipoblastoma is the most common lipomatous tumor in the retroperitoneum. The percentage of visible fat in tumor varies depending on the cellular composition of the lesion. The CT characteristics of teratoma are quite variable, which may be cystic, solid, on a combination of both. Typically teratoma appears as a large complex mass containing fluid, fat, fat-fluid level, and calcifications. Lymphoma is often homogeneous on both enhanced and unenhanced CT scans. Necrosis and calcification are rare on CT. In conclusion, making a final histological diagnosis of retroperitoneal tumor base on CT features is not often possible; however, CT can help to develop a differential diagnosis and determine the size and extent of the retroperitoneal neoplasms.

[Imaging and quantitative measurement of brain extracellular space using MRI Gd-DTPA tracer method].

OBJECTIVE: To observe the diffusion of Gd-DTPA in brain extracellular space (ECS) by magnetic resonance imaging(MRI) and investigate the feasibility of ECS measurement by using MRI tracer method in vivo. METHODS: 2 microL Gd-DTPA was introduced into ECS by caudate nucleus according to stereotaxic atlas in 8 Sprague Dawley(SD) rats (male, 280-320 g). The MRI scans were performed at 1 h, 3 h, 6 h, 9 h and 12 h respectively after administration. MRI appearances of Gd-DTPA diffusion and distribution was observed and compared. The MRI signal enhancement was measured at each time point. The neuroethology assessment was performed after MRI scanning at 12 h. RESULTS: The injection was accurate at the center of the caudate nucleus in 6 rats, while, at the capsula externa in other 2 rats. Gd-DTPA diffused isotropically after it was introduced into caudate nucleus, which spread into lateral cortex at 3 h. The MRI signal enhancement distributed mainly in the middle cerebral artery territory. A significant difference was found between the signal enhancement ratio at 1 h and that at 3 h in the original point of caudate nucleus (t=95.63, P<0.01), and the signal enhancement attenuated following the exponential power function y=1.7886x(-0.1776) (R2=0.94). In 2 rats with the injection point at capsula externa, Gd-DTPA diffused anisotropically along the fiber track of white matter during 1 h to 3 h, and spread into the lateral cortex at 6 h. CONCLUSION: The diffusion and clearance of Gd-DTPA in brain ECS could be monitored and measured quantitatively in vivo by MRI tracer method.

[Recurrent massive bloody pleural effusion caused by pancreatic pleural fistula in a case].

OBJECTIVE: To introduce the early clinical features and the main points of diagnosis and treatment of children with pancreatic pleural fistula presenting massive bloody pleural effusion. METHOD: The clinical data of symptoms, signs, laboratory examination, diagnosis and treatment methods of pancreatic pleural fistula in a child are presented. RESULT: A 4-year-old boy presented with one month history of intermittent fever, cough, chest tightness and chest pain. His pleural effusion collected from three thoracic closed drainage was hemorrhagic. He had no positive abdominal signs. His abdominal B-mode ultrasonography showed rough pancreatic echo. The levels of amylase in blood and pleural fluid were 495 U/L and 35 938 U/L, respectively. There was a fistulous tract from the thoracic cavity leading to the pancreas at thoracic surgical exploration. The child was cured by total parenteral nutrition, intravenous infusion of somatostatin and a stent placed in the pancreatic duct by endoscopic retrograde cholangiopancreatography (ERCP). CONCLUSION: The child with pancreatic pleural fistula in early stage mainly present respiratory symptoms and lack abdominal symptoms, so the diagnosis and treatment is often delayed. Significant increase of pancreatic amylase level in pleural effusion can be an important clue and basis for the diagnosis. If conservative therapy fails, the examination and treatment with ERCP should be considered.

[Diagnosis and treatment of invasive pulmonary aspergillosis in 21 children with non-hematologic diseases].

OBJECTIVE: To explore diagnosis and treatments of invasive pulmonary aspergillosis (IPA) in children with non-hematologic diseases. METHOD: Twenty one patients without hematological malignancy were diagnosed with proven or possible IPA from July 2002 to June 2008. The risk factors, clinical manifestations, chest radiographic findings, microbiological and histopathological evidence, diagnostic procedures, treatment and prognosis were retrospectively reviewed. RESULT: Five children had proven IPA, and 16 patients had possible IPA. Thirteen children were classified as having acute invasive pulmonary aspergillosis (AIPA), eight children as having chronic necrotizing pulmonary aspergillosis (CNPA). Definitive diagnosis of primary immunodeficiency (PID) was made in 6 children (4 with chronic granulomatous disease, 2 with cellular immunodeficiency); three children were suspected of having PID. Corticosteroids and multiple broad-spectrum antibiotics had been administered in 5 patients (3 of these 5 patients also had invasive mechanical ventilation). Two children had underlying pulmonary disease. Three patients had unknown risk factors. Among these three patients, two had history of environmental exposure. Fever and cough were present in all the children. Fine rales were found in nineteen children. Six children had hepatosplenomegaly. The common roentgenographic feature of AIPA in 13 patients was nodular or mass-like consolidation with multiple cavity. "air-crescent" was seen in 10 of patients with AIPA. Lobar consolidation with cavity and adjacent pleural thickening was found in all children with CNPA. The positive rate of sputum and/or BALF culture in AIPA and CNPA were 72.1% and 22.4%, respectively. A large number of septate hyphae on wet smear were found in all of the children whose sputum and/or BALF culture were positive. Lung biopsy was performed in 3 children with CNPA, and necrosis, granulomatous inflammation, as well as septate, branching hyphae were observed on histopathologic examination. Fifteen children were treated with anti-fungal therapy (amphotericin B, voriconazole, itraconazole and caspofungin used alone or in combination), symptoms and lung lesions resolved in 12 children. Three children died. Six children did not receive anti-fungal therapy and died. The side effects of amphotericin B include chill, fever, hypokalemia and transient increase in BUN, none of which needed discontinuation of the antifungal therapy. Children had a good tolerance to fluconazole and caspofungin, there were no apparent side effects. CONCLUSION: Most of the children without hematologic diseases who suffered from invasive pulmonary aspergillosis had risk factors or exposure history. Roentgenographic findings were relatively characteristic for invasive pulmonary aspergillosis. Risk factors and roentgenographic findings were clues to consider clinically invasive pulmonary aspergillosis. Sputum culture was the key point to clinical diagnosis. The patients in whom the antifungal therapy was initiated early had a good outcome.

Use of automatic tube current modulation with a standardized noise index in young children undergoing chest computed tomography scans with 64-slice multidetector computed tomography.

BACKGROUND: The automatic tube current modulation (ATCM) technique is available on multidetector computed tomography (MDCT) scanners, and its dose reduction benefits in clinical applications have been documented primarily in adult patients. PURPOSE: To evaluate the use of ATCM to reduce radiation dose while maintaining consistent image quality for young children undergoing 64-slice MDCT chest scans. MATERIAL AND METHODS: Chest scans (120 kV, small-scan field of view, 5-mm image slice thickness) were performed for 50 consecutive young children (0.2-3 years) using 64-slice volume computed tomography (VCT) with ATCM method and a noise index (NI) of either 8 or 9, depending on the patient's age. The scanner automatically selected the actual tube current based on NI values and patient attenuation as determined by scout scans for the study group. Image quality and volume-weighted CT dose index (CTDI(vol)) values (measured with small-scan field of view and 16-cm diameter CTDI phantom) were compared with images from a control group of 50 children acquired earlier using a standard protocol with fixed tube current. Two experienced pediatric radiologists assessed image quality, including resolution, noise, and artifacts, on a five-point scale. Scores greater than or equal to 3 were considered to be clinically acceptable. RESULTS: The mean image quality score and CTDI(vol) for the study and control groups were 3.46 and 2.34+/-0.71 mGy, and 4.65 and 6.68+/-0.62 mGy, respectively. While there was a statistically significant decrease in image quality in the study group, all studies had acceptable image quality, and CTDI(vol) with ATCM was about 65% lower than that with fixed tube current. The average image noise for the control group was 4.78+/-0.58, versus 7.53+/-0.42 and 8.28+/-0.40 for children under and above 1 year of age, respectively, in the study group. Despite a higher average noise level, the study group with ATCM demonstrated a lower standard deviation of image noise. CONCLUSION: The z-axis ATCM method produces consistent image quality for young children undergoing 64-slice MDCT chest scans. With noise levels of NI=8 and 9 at 5-mm image slice thickness, one may obtain clinically acceptable images with significantly reduced radiation dose.

Usefulness of 64-slice MDCT for follow-up of young children with coronary artery aneurysm due to Kawasaki disease: initial experience.

To evaluate the initial application and value of 64-slice multidetector computed tomography as an alternative diagnostic modality in the follow-up of young children with coronary artery aneurysm due to Kawasaki disease. Twelve boys (mean age 5.1 years, range 1.8-7.8 years) for follow-up (time range from 1.1 to 5.1 years) of known Kawasaki disease and coronary artery aneurysm underwent 64-slice MDCT ECG-gated coronary angiography. All data were acquired without breath holding. Two pediatric radiologists independently assessed image quality and the diameter of all coronary segments were measured for each patient. The number, position, shape and size of each coronary artery aneurysm were observed and compared with those of ECHO performed previously. A total of 118/156 segments permitted visualization with diagnostic image quality, the CT measurements showed good inter-observer and intra-observer reliability, coefficients were 0.93 and 0.88, respectively. A total of 30 coronary artery aneurysms were identified with measured mean of 7.5+/-3.8 mm in diameter, and of 12.4+/-9.1 mm in longitudinal lengths.10 tumors were small, 8 tumors were medium and 12 tumors were giant aneurysm. The affected segments included LM7/12(58.3%), 9/12(75%) of LAD1, 4/12(33.3%) of LAD2, 2/12(16.7%) of LCX1; 6/12(50%) of RCA1, 9/12(75%) of RCA2 and 4/12(33.3%) of RCA3, including affected two segments in 9 tumors and three segments in 1 tumor. Calcifications were found in 5 aneurysms and 3/5 with thrombosis; six stenotic segments were found. ECHO failed to detect 8 tumors with 2/8 in LAD, 1/8 in LCX and 5/8 in RCA, and those included 4 small aneurysms. The use of 64-slice MDCT angiography proved valuable for monitoring young children with Kawasaki disease. However, further study is necessary to specify the sensitivity and specificity of MDCT in the follow-up.

[Clinical studies of children with bronchiolitis obliterans].

OBJECTIVE: Bronchiolitis obliterans (BO) is a chronic airflow obstruction syndrome associated with inflammatory lesions of the small airways. The etiology, pathogenesis, effective treatment and prognosis of this disorder remain uncertain by now. There has been no large scale clinical research on BO in China. This study aimed to analyze the clinical characteristics of BO in children. METHODS: Clinical analysis was done on data of 42 patients (31 boys and 11 girls, aged from 7 months to 12 years and 2 months) with bronchiolitis obliterans diagnosed and treated in Beijing Children's Hospital from April 2001 to August 2007. The diagnostic criteria included typical clinical manifestations, specific pulmonary CT imaging and lung function tests. RESULTS: All the patients presented with persistent cough and wheezing. Crackles and wheezing were heard in most cases. Thirty-two (76.2%) cases were post-infectious BO, among whom 8 (25%) were supposed to be adenovirus pneumonia, 7 (21.9%) measles pneumonia and 2 (6.2%) respiratory syncytial virus infection. In 4 (9.5%) cases BO occurred after Steven-Johnson syndrome, and 1 (2.4%) after bone marrow transplantation. The constrictive obstruction in small airway occurred in 35 cases (89.7%), while mixed pattern in 4 (10.3%). Pulmonary CT revealed mosaic perfusion in 34 cases (81.0%), bronchiectasis in 14 cases (33.3%), bronchial wall thickening in 14 cases (33.3%), atelectasis in 4 cases (9.5%) and Swyer-James syndrome in 2 cases (4.8%). All the cases received oral corticosteroid and low doses of erythromycin or azithromycin, with corticosteroid and bronchodilator inhalation or oral montelukast. Follow up time was from 1 month to 5 years. Besides 2 cases in whom the disease was ameliorated in clinical presentation, pulmonary imaging and function, the rest experienced deterioration and one died. CONCLUSION: In most of the patients BO occurred following infections. The specific clinical presentations, imaging and pulmonary function are sufficiently informative for diagnosis. Most of the cases enrolled in this study had a poor outcome.