Tunable Gaussian filter based on tapered liquid crystal photonic bandgap fibre

A tunable Gaussian filter based on a tapered liquid crystal photonic bandgap fibre is presented. The filter is centred at lambda=1062 nm and has a 3 dB bandwidth of 150 nm. Tunability is achieved by exploiting the thermo-optic effect of the liquid crystals. A shift of 110 nm at the central wavelength is observed by increasing the temperature from 30 to 80degC     

Aorta transplantation in man: clinical and immunological studies

Aortic transplantation has progressively gained interest over the last few years and it is becoming a first choice indication in the substitution of infected prostheses. The most frequent complication in long-term vascular outcome (wall thickening, aneurysmatic dilation, stenosis), may occur through an immunological mechanism. In this study we investigated nine recipients, aged 48 to 65 years, of aorta segment replacement for anti-HLA antibody production (specificity and Ig class), CD3-CD4-CD8 T cell subpopulation dynamics and aorta wall thickness. Mismatch-specific IgG antibodies to HLA class I and HLA class II antigens were detected 1, 3 and 6 months after transplantation and persisted at a high concentration for at least 1 year. Furthermore, the absolute number of CD3, CD4 and CD8 positive lymphocytes increased progressively after aorta allograft. Tomography scanning showed a progressive thickness of the aorta wall. We can speculate that these anti-HLA antibodies in the recipients have the potential to harm the implant; therefore, aorta allograft should involve the induction of immunological tolerance by appropriate immunosuppressants.     

Positivity of pleural fluid cytologic examination in transudative pleural effusions

Because of the increased fragility of a freshly dissected aorta, the anastomosis between the aortic root and a tubular prosthesis is not forgiving of technical imperfections and may lead to troublesome bleeding. Providing an appropriate everting surface of contact and a homogeneous distribution of tension between the graft and aorta, as described here, should help obtain a hemostatic suture line.     

A randomized study comparing methylprednisolone plus chlorambucil versus methylprednisolone plus cyclophosphamide in idiopathic membranous nephropathy

Recent research on development of the implantable artificial pancreas for treatment of diabetes is reviewed, based on a Medline literature search that focused on glucose sensors, insulin pumps, and pump control systems. To achieve a closed feedback loop, a clinically applicable implantable artificial pancreas requires miniaturization and coordination of three components: an insulin pump, a blood glucose monitor, and a control system. Recent clinical studies have demonstrated that implantable insulin pumps are feasible for satisfactory control of diabetes for over a year, with the major complication being obstruction of the infusion catheter. Research on continuous glucose sensors has predominantly used the glucose-oxidase reaction or near-infrared light spectroscopy. Implantable glucose oxidase sensors have been limited by local factors causing unstable signal output, whereas optical sensors must overcome interference by substances with absorption spectra similar to glucose. Investigators have developed control algorithms in an effort to stabilize operation of the integrated artificial pancreas in the face of variations in sensor output and pump function. The ultimate goals of fully automatic glucose control by an artificial pancreas include prevention or delay of chronic complications of diabetes, lowered risk of hypoglycemia, and less patient inconvenience and discomfort than with multiple daily glucose self-tests and insulin injection. The recent developments of optical glucose sensing, radiotelemetry systems to link pump and sensor, and miniaturization and refinement of insulin pumps are significant steps toward a clinically applicable artificial pancreas.     

Autosomal dominant medullary cystic disease: a disorder with variable clinical pictures and exclusion of linkage with the NPH1 locus

BACKGROUND: The nephronophthisis-medullary cystic disease (NPH/MCD) complex represents a heterogeneous group of hereditary tubulointerstitial nephritis. The most common variant is juvenile recessive NPH, for which a gene locus (NPH1) has been mapped on chromosome 2q13. MCD is a less common dominant condition usually recognized later in life, which resembles NPH in many aspects, still presenting remarkable clinical differences. Nothing is known about the chromosome locus of MCD. METHODS: Five MCD families were studied. Diagnosis was made by inference from family history, type of inheritance, clinical signs and histology. Multipoint linkage analysis was performed by markers D2S293, D2S340 and D2S160 spanning the entire NPH1 locus. RESULTS: Diagnosis of MCD was made in 28 affected members (16 males; 12 females), belonging to five families. Histological diagnosis was available in 10 patients; clinical diagnosis in 11; seven deceased relatives had diagnosis of chronic nephritis. The age at diagnosis ranged from 8 to 65 years. Renal medullary cysts were found in a minority of patients. In family 1, the disease was associated with hyperuricaemia and gouty arthritis. Progression of renal disease presented intra- and extra-family variability with members of the same family showing mild elevation of creatinine or terminal renal failure. The NPH1 locus associated to recessive NPH was excluded from linkage to the dominant MCD. CONCLUSIONS: MCD might be more common than previously assumed. Variability in clinical presentation and absence of histopathological hallmarks contribute to make the diagnosis uncommon. The most remarkable clinical difference with NPH is the age of onset in some kindreds and a delayed progression towards renal failure. The exclusion of linkage to the NPH1 locus suggests the existence of an MCD responsible locus, still to be mapped.     

Extraction and partial characterization of proteolytic activities from the cell surface of Lactobacillus helveticus Zuc2

Proteolytic activities were extracted from a dairy Lactobacillus helveticus strain and partially characterized. A first cell envelope proteinase (CEP) was extracted using a high ionic strength buffer, both in the presence and in the absence of Ca²⁺. Moreover, cell treatment by 5 M LiCl allowed for the selective removal of the S-layer protein and CEP, suggesting an enzyme ionic linkage to the cell envelope similar to that observed for the Slayer structure. The enzyme specificity against α_s1-CN (f1-23) showed unusual activity on the Lys₃-His₄ bond compared with other proteinases of the same species. A second proteinase appeared to be linked to the cell membrane because it was extractable only after membrane disgregation by detergents. Its specificity against CN fractions and α_s1-CN (f1-23) was different from that of the first CEP; moreover, the measured activity was lower than that of CEP.     

Proteins and protein fragments in nephrotic syndrome: Clusters, specificity and mechanisms

Proteinuria is the hallmark of renal diseases and the characterization of the urinary protein composition may become an important source of information for diagnosis and research. So far, protein analysis in urine has been utilized for a generic individuation of site-specific defects (glomerular vs. tubular) but there is a need for an extension of proteomics to specific urinary biomarkers in selected clinical conditions. The identification of fragments of proteins in plasma and urine may increase the spectrum of urinary biomarkers. The unique speculative application so far proposed for protein fragments is nephrotic syndrome, and specifically focal segmental glomerulosclerosis, in which case they reflect intrinsic proteolysis occurring in plasma and represent surrogate biomarkers of the disease activity. Albumin is probably the most studied protein. Several of the albumin fragments present a peculiar distribution of the fingerprint peptide pattern containing both the N-terminal region and the C-terminal domain with a complete lack of any MS signals for the internal sequence region. Their characterization utilizing new strategies based on 2-D nondenaturing electrophoresis is now in progress. Studies on a direct characterization of proteases in plasma and urine will also define the participation of proteases to the genesis of renal diseases.