Expanding the product portfolio of carbon dioxide and hydrogen-based gas fermentation with an evolved strain of Clostridium carboxidivorans.

CO2:H2-based gas fermentation with acetogenic Clostridium species are at an early stage of development. This work exploited the Adaptive Laboratory Evolution technique to improve the growth of C. carboxidivorans P7 on CO2 and H2. An adapted strain with decreased growth lag phase and improved biomass production was obtained. Genomic analysis revealed a conserved frameshift mutation in the catalytic subunit of the hexameric hydrogenase gene. The resulted truncated protein variant, most likely lacking its functionality, suggests that other hydrogenases might be more efficient for H2-based growth of this strain. Furthermore, the adapted strain generated hexanol as primary fermentation product. For the first time, hexanol was produced directly from CO2:H2 blend, achieving the highest maximum productivity reported so far via gas fermentation. Traces of valerate, pentanol, eptanol and octanol were observed in the fermentation broth. The adapted strain shows promising to enrich the product spectrum targetable by future gas fermentation processes.

Numerical study of the effect of channel aspect ratio on particle focusing in acoustophoretic devices.

Acoustophoretic microfluidic devices are promising non-contact and high-throughput tools for particle manipulation. Although the effectiveness of this technique has been widely demonstrated for applications based on micrometer-sized particles, the manipulation and focusing of sub-micrometer ones is challenging due to the presence of acoustic streaming. In this article, our study has the aim to investigate and understand which geometrical parameters could be changed to limit the acoustic streaming effect. We numerically study the well-known rectangular cross section of a microfluidic channel and perform a parametric study of the aspect ratio for several particle sizes. The efficiency of the focusing, is explored for different sized particles in order to identify a trend for which the acoustic streaming does not drastically influence the focusing motion of the particles. The possibility to efficiently separate different solid components in liquid suspensions, i.e. the whole blood, is crucial for all applications that require a purified medium such as plasmapheresis or an increase of the concentration of specific subpopulation as the outcome, such as proteomics, cancer biomarker detections and extracellular vesicles separation.

Theoretical considerations regarding the thione-thiol tautomerism in 2-(5-mercapto-1,3,4-thiadiazol-2-ylthio)acetic acid.

The acidity constants Ka1 and Ka2 of 2-(5-mercapto-1,3,4-thiadiazol-2-ylthio)acetic acid have been determined both by experimental and theoretical methods. pKa computations at B3LYP/6-311+G(d,p) level of theory were carried out for the two tautomeric forms, thiol and thione, of the above-mentioned acid. Comparisons between the experimental and theoretical values led to the establishing of the most stable tautomer of 2-(5-mercapto-1,3,4-thiadiazol-2-ylthio)acetic acid in aqueous solution. Also, a DFT study regarding the reactivity, aromaticity and population analysis of the two tautomers has been performed.

Power M-Mode Doppler and single-gate spectral analysis using a 2-MHz pulsed-wave Doppler transducer to directly detect cervical internal carotid artery stenosis: use of the continuity principle: report of a novel technique.

BACKGROUND AND PURPOSE: We hypothesized that direct cervical investigation with Power M-Mode Doppler (PMD) combined with single-gate Doppler spectral analysis (SGDSA) using a 2-MHz pulsed-wave Doppler transducer would show reasonable accuracy parameters when compared with standard color-coded carotid duplex ultrasound (CDU). METHODS: We prospectively screened for cervical internal carotid artery (ICA) stenosis by direct observation using a 2 MHz PMD/SGDSA device. PMD identified the artery (location, depth, flow direction) and SGDSA assessed waveform; peak systolic, end diastolic, and mean flow velocities (MFV) of the common carotid artery; cervical ICA proximally and distally; and external carotid artery. Diagnostic accuracy was compared with concurrent carotid duplex ultrasound. The continuity principle was applied using the proximal/distal cervical ICA MFV ratio. RESULTS: We examined 456 vessels (228 patients). Using ICA proximally/ICA distally MFV ratio of 1.5 or greater or absence of ICA signature, for 40% to 59% or greater stenosis (including occlusions), sensitivity was 75.4%, specificity 99.8%, positive predictive value 97.7%, negative predictive value 96.6%, and accuracy 96.7%. For MFV ratio 1.6 or greater or absence of ICA signature and 60% to 79% or greater stenosis (including occlusions), sensitivity was 92.3%, specificity 98.1%, positive predictive value 81.8%, negative predictive value 99.3%, and accuracy 97.6%. CONCLUSIONS: Use of combined PMD and SGDSA to directly observe the extracranial ICA is reasonably accurate compared with carotid duplex ultrasound. Using the MFV ratio of proximal/distal extracranial ICA improves accuracy parameters and provides a quick and effective bedside screen for ICA stenosis. This novel technique should be considered part of the standard PMD/transcranial Doppler examination.

Mediastinal lymphoma: quantitative changes in gadolinium enhancement at MR imaging after treatment.

PURPOSE: To compare changes in gadolinium enhancement at magnetic resonance (MR) imaging with outcome in mediastinal lymphoma after treatment. MATERIALS AND METHODS: Thirty-one patients with bulky mediastinal lymphoma (17 with Hodgkin disease, 14 with non-Hodgkin lymphoma) underwent serial MR imaging before and up to 50 months after treatment, with routine follow-up (including computed tomography). Signal intensity ratios between masses and muscle were calculated on T1-weighted, T2-weighted, and contrast material-enhanced T1-weighted spin-echo MR images. The percentage enhancement and signal intensity ratios of mediastinal masses on T2-weighted MR images were calculated at diagnosis and during and after treatment. RESULTS: Twenty-one patients with persistent complete remission had a mean percentage enhancement of residual masses (4%; range, -26% to 40%) that was significantly lower than that of initial masses (78%; range, 41%-124%). Although the mean signal intensity ratio of residual masses on T2-weighted images was significantly lower than that of initial masses, an increase in this ratio was observed in four patients after treatment. In seven patients with relapse, the percentage enhancement value of the residual mass was as high as that of the initial mass. CONCLUSION: Gadolinium enhancement of lymphomatous masses of the mediastinum decreased markedly after treatment in patients in continuous complete remission but not in patients with relapse.

MRI of intralesional hemolysis in focal nodular hyperplasia of the liver.

A case of Kasabach-Merritt syndrome caused by focal nodular hyperplasia of the liver is presented with atypical magnetic resonance findings due to intratumoral hemosiderin deposition. The high sensitivity of magnetic resonance imaging for iron served to identify the site of hemolysis in this patient with Kasabach-Merritt syndrome.

Acute swelling of the limbs: magnetic resonance pictorial review of fascial and muscle signal changes.

OBJECTIVE: This pictorial review analyzes the magnetic resonance (MR) fascial/muscular changes in 69 patients referred as emergencies with acute swelling of the limbs (ASL) from various causes. METHODS AND MATERIAL: A prospective MR imaging (MRI) study of 69 patients referred as emergencies for ASL was performed. Our population consisted of 45 patients with skin and soft-tissue infections (cellulitis and necrotizing fasciitis, and pyomyositis), six patients with soft-tissue inflammatory diseases (dermatomyositis, graft-versus-host disease), 11 patients with acute deep venous thrombosis, three patients with rhabdomyolysis, one patient with acute denervation and three other patients with rare diseases. Hematomas, tumorous or infectious bone involvement and soft-tissue tumors were excluded. All studies included spin echo T1-weighted images and spin echo T2-weighted images. Gadolinium-enhanced spin echo T1-weighted images were obtained when an abscess was suspected on T2-weighted images. Selective fat-saturated T1- and T2-weighted sequences were also used. MRI analysis was performed to obtain a compartmentalized anatomical approach according to the location of signal abnormalities in subcutaneous fat, superficial and deep fascia and muscle. RESULTS: In all patients with ASL, MRI demonstrated soft-tissue abnormalities involving subcutaneous fat, superficial fascia, deep fascia, or muscle. Although MR findings were non-specific, MRI appears sensitive for detecting subtle fascial and muscle signal changes. CONCLUSIONS: In skin and soft-tissue infections, MRI can be helpful for therapeutic management by determining the depth of soft-tissue involvement, particularly within fasciae and muscles, which is partly related to the severity of cellulitis with severe systemic manifestations. MRI can also aid the surgeon in diagnosing abscesses. In inflammatory diseases, MRI can determine the best site for biopsy and also monitor therapeutic response.

[Mercury pulmonary embolism. Two case reports]. / Embolies pulmonaires mercuriques. A propos de deux observations.

Mercury pulmonary embolism following intentional or accidental injection of metallic mercury are uncommon. Generally, there are few clinical signs (acute pneumopathy in 50% of the cases). Chest x-ray shows multiple and bilateral point opacities with a metallic density. We present two cases of mercury pulmonary embolism after intentional intravenous mercury injection (one attempted suicide and one HIV+ drug addict).

Benign and malignant hepatocellular tumors: evaluation of tumoral enhancement after mangafodipir trisodium injection on MR imaging.

The aim of this work was to study the ability of mangafodipir trisodium (Mn-DPDP)-enhanced MR imaging in differentiating malignant from benign hepatocellular tumors. Eleven patients with pathologically proved hepatocellular carcinomas, six with focal nodular hyperplasias, and one with a single hepatocellular adenoma were examined by spin-echo and gradient-echo T1-weighted sequences before, 1 h after, and 24 h after intravenous injection of Mn-DPDP (5 micromol/kg). Quantitative analysis including enhancement and lesion-to-liver contrast-to-noise ratio, and qualitative analysis including the presence of a central area and a capsule were done on pre- and post-Mn-DPDP-enhanced images. Enhancement was observed in all the tumors with significant improvement (p < 0.05) in contrast-to-noise ratio 1 h after, and 24 h after intravenous injection of Mn-DPDP. There were no significant differences in the mean enhancement and the mean contrast-to-noise ratio (CNR) between benign and malignant tumors. No enhancement was seen within internal areas observed in 7 hepatocellular carcinomas, and in 5 focal nodular hyperplasias, and within capsules which were observed in 9 hepatocellular carcinomas. In our study, Mn-DPDP increased CNR of both benign and malignant tumors but did not enable differentiation between benign and malignant tumors of hepatocellular nature.

Pulmonary function in sickle cell disease with or without acute chest syndrome.

Recurrent acute chest syndrome (ACS) has been suggested as a risk factor for chronic lung dysfunction in sickle cell disease. To investigate this hypothesis, lung function tests were performed in 49 sickle cell disease outpatients whose condition was stable, including 23 patients with a history of two to four episodes of ACS (ACS+) and 26 with no history of ACS (ACS-). The two groups were comparable regarding the sex ratio, body mass index, smoking history, physical characteristics, clinical history and usual lung function tests. Respiratory resistance (Rrs), measured using the forced oscillation technique, increased with the number of ACS episodes (r=0.55, p<0.0001) and a significant relationship was observed between Rrs as an independent variable and the expiratory flow rates at 25, 50 and 25-75% of the forced vital capacity as explanatory variables (r= 0.36, p<0.02; r=0.35, p<0.02; and r=0.4, p<0.006, respectively), with higher Rrs being associated with lower expiratory flow rates. The transfer factor (TL,CO) and transfer coefficient (KCO) for CO were significantly higher in the ACS+ group than in the ACS-group (TL,CO=84+/-4 versus 71+/-3%, p<0.004 and KCO=102+/-5 versus 90+/-3%, p<0.05, respectively). The data demonstrate that obstructive lung dysfunction is fairly common in sickle cell disease and suggest that recurrent acute chest syndrome may contribute specific obstructive defects. The increase in respiratory resistance associated with acute chest syndrome was accompanied by an increase in diffusion capacity, suggesting that it may have been related to an increase in lung blood volume.

[Computed tomography of lymphoma in adults. The Study Group of Lymphoma in Adults]. / Tomodensitométrie des lymphomes de l'adulte. Groupe d'Etude des Lymphomes de l'Adulte.

In order to avoid misinterpretation especially at the initial imaging procedure as well as on follow up CT, the authors illustrate the features of the multiple nodal and extranodal localisations of lymphoma. The evolutive findings are emphasized.

Effects of positive end-expiratory pressure and different tidal volumes on alveolar recruitment and hyperinflation.

BACKGROUND: The morphologic effect of positive end-expiratory pressure (PEEP) and of two tidal volumes were studied by computed tomography to determine whether setting the tidal volume (Vt) at the upper inflection point (UIP) of the pressure-volume (P-V) curve of the respiratory system or 10 ml/kg have different effects on hyperinflation and alveolar recruitment. METHODS: Alveolar recruitment and hyperinflation were quantified by computed tomography in nine patients with the acute respiratory distress syndrome (ARDS). First, end expiration was compared without PEEP and with PEEP set at the lower inflection point of the P-V curve; second, at end inspiration above PEEP, a reduced Vt set at the UIP (rVt) and a standard 10 ml/kg Vt (Vt) ending above the UIP were compared. Three lung zones were defined from computed tomographic densities: hyperdense, normal, and hyperinflated zones. RESULTS: Positive end-expiratory pressure induced a significant decrease in hyperdensities (from 46.8 +/- 18% to 38 +/- 15.1% of zero end-expiratory pressure (ZEEP) area; P < 0.02) with a concomitant increase in normal zones (from 47.3 +/- 20.9% to 56.5 +/- 13.2% of the ZEEP area; P < 0.05), and a significant increase in hyperinflation (from 8.1 +/- 5.9% to 17.8 +/- 12.7% of ZEEP area; P < 0.01). At end inspiration, a significant increase in hyperinflated areas was observed with Vt compared with rVt (33.4 +/- 17.8 vs. 26.8 +/- 17.3% of ZEEP area; P < 0.05), whereas no significant difference was observed for both normal and hyperdense zones. CONCLUSIONS: Positive end-expiratory pressure promotes alveolar recruitment; increasing Vt above the UIP seems to predominantly increase hyperinflation.

Hyperintense benign liver lesions on spin-echo T1-weighted MR images: pathologic correlations.

BACKGROUND: To determine the incidence of hyperintensity on T1-weighted spin echo (SE) images in benign liver lesions, value of fat-suppressed magnetic resonance (MR) imaging for the detection of fat within these lesions, and the causes of hyperintensity by correlation to pathologic examinations. METHODS: Five hundred forty-nine patients with 805 benign liver lesions including 585 hemangiomas, 188 focal nodular hyperplasias (FNHs), 14 hepatic adenomas (HAs), 14 focal fatty infiltrations (FFIs), two biliary cystadenomas, and two hemorrhagic cysts were examined by T2-weighted and T1-weighted SE MR imaging. For hyperintense lesions on T1-weighted SE images, fat-suppressed images were obtained by selective presaturation of fat. RESULTS: Thirty-two lesions (four FNHs, 10 HAs, 14 FFIs, two biliary cystadenomas, and two hemorrhagic cysts) appeared hyperintense on T1-weighted SE images; 21 of these became hypointense on the fat-suppressed T1 weighted SE images (one FNH, six HAs, and 14 FFIs) and contained fat at pathological examination. The other 11 lesions remained hyperintense on fat-suppressed T1-weighted SE images and had no fat deposition. Causes of hyperintensity in these cases were sinusoidal dilatation, copper deposition, hemorrhage, and high protein content. CONCLUSION: Among benign liver lesions, hyperintensity on T1-weighted SE images is rare (3.9%). Causes of this hyperintensity are fat deposition, copper accumulation, sinusoidal dilatation, bemorrhage, and high protein content. Fat-suppressed imaging can distinguish fat deposition from other causes of hyperintensity.

Intrapleural administration of streptokinase in complicated purulent pleural effusion: a CT-guided strategy.

OBJECTIVE: To determine the usefulness and the results of a strategy using intrapleural streptokinase (SK) instillation guided by repeated computed tomography (CT) scan examinations in pleural empyemas unresponsive to chest tube drainage. DESIGN: A retrospective chart review. SETTING: The medical Intensive Care Unit and Department of Radiology, in a university hospital. PATIENTS: Sixteen patients with empyema who had a persistent pleural effusion despite drainage, among 37 patients with infectious pleural effusion. INTERVENTIONS: In the 16 patients, CT examination was performed before and at least once after SK. Intrapleural SK was instilled, either through the chest tube or via a needle puncture, according to the CT scan results. RESULTS: The first CT scan confirmed a persistent effusion in all, showing a multiloculated effusion in 13 patients, and an ectopic loculus in one. The first SK instillation resulted in a dramatic increase of fluid drained per day (from 68 +/- 28 ml to 567 +/- 262 ml; p < 0.001), leading to complete resolution in 11 patients, while the others required a second CT scan-guided procedure. In one, the chest tube was misplaced, while in two, transparietal injection was needed. Finally, a complete resolution was observed in 14 (87.5%) of the patients. Two patients had a poor initial response to SK and were eventually scheduled for video-thoracoscopy. A single episode of chills and fever was observed among 32 SK instillations. CONCLUSION: CT-guided SK instillation in pleural empyema appears to be safe, and allowed complete resolution in 87.5% of our patients.

Color Doppler twinkling artifact in hyperechoic regions.

PURPOSE: To investigate a new color Doppler ultrasound (US) artifact that manifested as a rapidly changing mixture of red and blue behind a strongly reflecting structure. MATERIALS AND METHODS: In 140 consecutive patients with parenchymal calcifications seen at US, the presence of color signal was assessed in calcified areas relative to adjacent noncalcified tissue. The artifact, called the twinkling color artifact, was stimulated with various strongly reflecting structures immersed in still water. RESULTS: The artifact was found in 42 parenchymal calcifications. In vitro experiments showed that the twinkling artifact was present in granular structures, whereas no color signal was noted in smooth surfaces. The "twinkling sign" appeared to be generated by a strongly reflecting medium composed of individual reflectors. CONCLUSION: The presence of a color signal close to calcifications should be interpreted with caution, and a flow spectrum should always be recorded to eliminate the twinkling artifact.

Phase II trial of fludarabine monophosphate as first-line treatment in patients with advanced follicular lymphoma: a multicenter study by the Groupe d'Etude des Lymphomes de l'Adulte.

PURPOSE: Fludarabine monophosphate (FAMP) is a major drug in the treatment of chronic lymphocytic leukemia and showed efficacy in selected groups of patients with low-grade lymphomas, most of them pretreated. The aim of this trial was to assess the efficacy and the toxicity of FAMP in untreated patients with follicular lymphoma. PATIENTS AND METHODS: Fifty-four untreated patients with advanced follicular lymphoma were treated with intravenous (i.v.) fludarabine at a dose of 25 mg/m2/d during 5 days every 4 weeks, to a maximum of nine cycles. RESULTS: The toxicity of the drug was mild, mainly granulocytic. Granulocytopenia > or = 3 (World Health Organization [WHO]) was observed during 48 of 328 cycles (14.6%) and in 22 of 53 (41%) patients assessable for toxicity. Fludarabine had to be stopped prematurely because of toxicity in nine patients: marrow toxicity in five, peripheral neuropathy in two, and interstitial pneumonitis and hepatitis in one patient each. Among 49 patients assessable for response, the overall response rate was 65% and the complete response (CR) rate 37%. The median progression-free survival interval for all patients was 13.6 months. CONCLUSION: These results confirm that fludarabine is active when used as first-line treatment in patients with follicular lymphoma and has a low toxicity rate. It may be used as single treatment in elderly patients. Associations of fludarabine with other drugs active against follicular lymphoma need to be determined.

Impact of magnetic resonance imaging on the diagnosis of abdominal complications of paroxysmal nocturnal hemoglobinuria.

Magnetic resonance (MR) imaging is a method of choice for assessing vascular patency and parenchymal iron overload. During the course of paroxysmal nocturnal hemoglobinuria (PNH), it is clinically relevant to differentiate abdominal vein thrombosis from hemolytic attacks. Furthermore, the study of the parenchymal MR signal intensity adds informations about the iron storage in kidneys, liver, and spleen. Twelve PNH patients had 14 MR examinations of the abdomen with spin-echo T1- and T2-weighted images and flow-sensitive gradient echo images. Vessels patency and parenchymal signal abnormalities--either focal or diffuse--were assessed. MR imaging showed acute complications including hepatic vein obstruction in five patients, portal vein thrombosis in two patients, splenic infarct in one patient. In one patient treated with androgens, hepatocellular adenomas were shown. Parenchymal iron overload was present in the renal cortex of eleven patients with previous hemolytic attacks. On the first MR study of the remaining patient with an acute abdominal pain showing PNH, no iron overload was present in the renal cortex. Follow-up MR imaging showed the onset of renal cortex iron overload related to multiple hemolytic attacks. Despite the fact that all our patients were transfused, normal signal intensity of both liver and spleen was observed in three of them. MR imaging is particularly helpful for the diagnosis of abdominal complications of PNH.

Magnetic resonance imaging of penile rupture: aid to diagnosis.

We report on a patient with atypical clinical findings in whom magnetic resonance imaging confirmed the suspicion of penile rupture. The tear appeared as an obvious discontinuity of the low signal intensity of the tunica albuginea and was associated with a hematoma. We conclude that magnetic resonance imaging is useful for confirming the diagnosis of penile rupture when clinical findings are atypical, indicating surgical repair.