Microporous Silicon Nitride-Based Solid Bases

High surface area, microporous, amorphous silicon imidonitride, characterized by infrared spectroscopy, MAS 29Si NMR and surface area and porosity measurements has been prepared by the treatment of co-oligomers of methylsilazane and dimethyl silazanes with gaseous ammonia at temperatures up to 700°C. The material has a narrow pore-size distribution showing a maximum in the range associated with wide- pore zeolites (ca. 0.72 nm mean). Variation of the organic content of the silazane is a means of controlling the surface area of the resulting solid. The Knoevenagel condensation reaction of benzaldehyde with a series of active methylene compounds has been used to probe the basicity and size-selectivity of these microporous solid base catalysts.

An evaluation of indices of gross pathology associated with the nematode Anguillicoloides crassus in eels

This study compares two alternative indices for quantifying the gross pathology of the swimbladder of eels, Anguilla anguilla (L.), infected with the nematode Anguillicoloides crassus. Two observers recorded twice the scores obtained by the two indices on the same set of 71 wild caught eels (from elver to silver eels, French Mediterranean lagoons). The Length Ratio Index (LRI), performed better than the Swimbladder Degenerative Index (SDI), in three of four predefined criteria of decision. First, the LRI better correlated with an estimate of the swimbladder volume reduction, a functional consequence of the infection (representativeness). Also, the LRI was less prone to subjectivity (inter-observer variability) and more precise (intra-observer variability), although less easy to generate (time needed for measurement/assessment). Using a sub-sample of 32 unaffected eels (showing minor if any swimbladder damage and no living worms at autopsy), we ascertained a linear relationship between the swimbladder length and the total body length, a prerequisite of isometric growth, to definitively accept the new ratio index as a valid alternative to the SDI. Also, because the LRI can be recorded on live specimens with radio-imagery (non-invasive method), we recommend its use, and provide a graph of correspondence between the SDI scores, the LRI scores and the estimated proportion of gas loss in the swimbladder.

[Popliteal venous thrombosis associated with a false aneurysm revealing femoral exostosis in a child]

Recent unprovoked and symptomatic thrombosis of the left popliteal vein was diagnosed in a 9-year-old girl. Treatment with low-molecular-weight heparin was initiated in association with vitamin K antagonist (INR 2.5), and compressive stockings. Two and a half months later, the ultrasound examination revealed a false aneurysm of the left distal superficial femoral artery. Knee X-rays showed a distal femoral exostosis. MRI clarified the relationship between the false aneurysm and the exostosis. Bone scintigraphy eliminated multiple exostoses. Resection of the false aneurysm associated with end-to-end femoro-popliteal saphenous bypass and exostosectomy in the same operative time were performed. On histopathological examination there was no sign of malignant transformation. Vascular complications of exostoses are infrequent and the association with deep venous thrombosis and false aneurysm is exceptional. This case report illustrates the contribution of knee X-rays to unravel this unusual clinical presentation.

Continuing utilisation of specialised health services in extremely preterm infants

OBJECTIVE

To compare healthcare use from neonatal discharge to 18 months corrected age (CA) of two groups of extremely preterm neonates (23-25 vs 26-28 weeks).

DESIGN

Cohort study.

PATIENTS

Infants born at < or =28 weeks and admitted in three hospital centres in Quebec, Canada (n=254).

MAIN OUTCOME MEASURES

Neurodevelopmental outcomes and healthcare use from neonatal discharge to 18 months CA.

RESULTS

Re-hospitalisation rates occurred in 57% of children born at 23-25 weeks and in 49% of those born at 26-28 weeks. In these two age groups, by 18 months, 61% vs 59% were followed in physical or occupational therapy, 29% vs 17% were enrolled in a long-term rehabilitation program, 38% vs 28% used prescribed medication, and 59% vs 33% required medical assistive devices, respectively. Risk of re-hospitalisation was related to bronchopulmonary dysplasia (BPD), severe brain injury, use of home oxygen or an apnoea monitor and older age at neonatal discharge. Multiple births, BPD, severe brain injury, older age at neonatal discharge and single parenthood were associated with risk of using out-patient health services above average (>2 services).

CONCLUSION

Extremely preterm children are frequently re-hospitalised during infancy and use a substantial amount of healthcare resources. These results highlight the importance of resource allocation to preterm infants for medical and rehabilitation services after discharge from the neonatal intensive care unit.

Use of cutaneous flap for continent cystostomy (daoud technique)

PURPOSE

We present the results of a new technique using a pedicled cutaneous flap for continent cystostomy.

MATERIALS AND METHODS

A total of 15 boys and 8 girls (mean +/- SD age 13.4 +/- 6.4 years) underwent continent cystostomy for neurogenic bladder (20), bladder exstrophy (2) and sequelae of hypospadias (1) between 1999 and 2008. In this procedure a rectangular pedicled flap is surgically elevated from a hairless area on the abdomen. The flap is tubularized and passed through the anterior abdominal wall directly into the bladder. A submucosal detrusor incision is made to expose the bladder mucosa, and the distal part of the flap is anastomosed to the bladder mucosa in a circular manner. The tube is positioned along the incised detrusor, which is closed over. Viability of the flap, self-catheterization management and continence status are then evaluated.

RESULTS

Mean +/- SD followup was 4.5 +/- 3.1 years. There was 1 case of distal necrosis of the flap, which required a secondary surgery using the Mitrofanoff technique. The 22 remaining flaps were initially viable, although 2 patients were eventually lost to followup and 3 subsequently presented with false-passage incidents requiring a few days of calibration using a balloon catheter. Dryness was achieved immediately in 73% of the cases. After adding a complementary bulking agent the dryness rate reached 77%.

CONCLUSIONS

We present a novel approach to continent cystostomy that is safe and easy to perform. This technique is a less invasive and more efficient alternative to other commonly used approaches.

Huge intramedullar neurenteric cyst with intrathoracic development in a 1 month-old boy: excision though the anterior approach. A case report and review of the literature

Spinal neurenteric cyst is a rare congenital lesion that may occur either alone or in the context of a complex malformative disorder. Our case is unusual because of its rare intramedullary location, the association with an important intrathoracic development, and the age of the child at presentation (1 month). An anterior approach through a right-sided lateral thoracotomy was performed for a total resection of the intrathoracic part and a subtotal resection for the intramedullar portion. During 2 years of follow-up, the child presented no neurological deficit and post-operative magnetic resonance imaging found a small residue fixed on the anterior spinal cord without progression.

Method for macromolecular colocalization using atomic recombination in dynamic SIMS

Localizing two or more components of assemblies in biological systems requires both continued development of fluorescence techniques and invention of entirely new techniques. Candidates for the latter include dynamic secondary ion mass spectrometry (D-SIMS). The latest generation of D-SIMS, the Cameca NanoSIMS 50, permits the localization of specific, isotopically labeled molecules and macromolecules in sections of biological material with a resolution in the tens of nanometers and with a sensitivity approaching in principle that of a single protein. Here we use two different systems, crystals of glycine and mixtures of proteins, to show that the formation of recombinant CN secondary ions under Cs bombardment can be exploited to create a new colocalization technique. We show experimentally that the formation of the recombinant (13)C(15)N secondary ion between (13)C- and (15)N-labeled macromolecules is indeed an indicator of the distance between the interacting macromolecules and on their shape. We build up a convolution model of the mixing-recombination process in D-SIMS that allows quantitative interpretations of the distance-dependent formation of the recombinant CN. Our results show that macromolecules can be colocalized if they are within 2 nm of one another. We discuss the potential advantages of this new technique for biological applications.