Histological and scanning electron microscopic alterations in ileal conduit depending on the time factor

Five ileal conduit biopsies, taken after 1-7 years, were examined by light microscopy and scanning electron microscopy. The total height of the lamina mucosa decreased from 700 to 275 microns. The height of the villi diminished from 550 to 50 microns; the depth of the crypts increased from 130 to 244 microns and the villus-crypt index changed from 4.2 to 0.2. Signs of chronic inflammation could be observed. Scanning electron microscopy shows that the number of microvilli per cell was markedly reduced. There was a varied picture of different stages of atrophy. After 3 years microvilli could no longer be observed. In view of the prolonged urinary contamination time, it appears to be imperative to check neobladders with regard to possible carcinoma induction.     

Transluminal excimer laser angioplasty of experimentally-induced atheromatous plaque: morphologic changes and importance of proliferation of smooth muscle cells

To determine the time-course of morphological changes after excimer laser treatment of atherosclerotic carotid arteries, laser angioplasty was performed in 34 rabbits after production of an intimal plaque (13 +/- 6 cell layers, 30 +/- 9% stenosis) using electrical stimulations. The animals were sacrificed 3, 7, 14, 21, 28, and 42 days after laser treatment. A total or subtotal thrombotic occlusion was found in four cases. No perforation was observed, but in 10 animals histological examination evidenced a partial ablation of the medial layer with signs of local thrombus formation and local reduction of SMC in the media. In five animals a stenosis of more than 50% of luminal reduction was due to intimal proliferation of smooth muscle cells (SMC), as determined by a monoclonal antibody against alpha-actin. After the initial ablation, a continuous increase of intimal cell layers was found, from 7 +/- 6 cell layers (19 +/- 9% stenosis) at 7 days, to 28 +/- 5 cell layers (45 +/- 18% stenosis) at 28 days following excimer laser angioplasty (p less than 0.01). After 42 days no additional increase of intimal thickening occurred. Our data suggest that incidence and morphology is comparable to the proliferative response of SMC following conventional balloon angioplasty.     

Tobacco-smoking prevalence among physicians and nurses in countries with different tobacco-control activities.

The aim of the study was to compare rates of smokers among physicians and nurses in the USA, a country with relatively high levels of activity in tobacco control, with those in a country with low levels of tobacco-control efforts. Analysis of interview data in three cross-sectional population studies was carried out. The tobacco-smoking rate of the physicians in the country with low prevention activity dropped to 18%, which is still much higher than the smoking rate in the US and other European countries. In conclusion, prevention activity on a national level might contribute to reducing the rate of current smokers among physicians to a large extent, less so in nurses.     

In vitro evaluation of ablation parameters of normal and fibrous aorta using smooth excimer laser coronary angioplasty

A modified exeimer laser energy delivery system was used to irradiate 100 segments of normal and fibrous aorta in vitro. The laser beam was scanned into 8 fiber bundles consisting of 50 fibers each resulting in a reduction of the applied pulse energy. The total repetition rate was increased to 150 Hz in order to keep the repetition rate per fiber bundle close to 20 Hz and to minimize thermal injury. The results demonstrate that effective ablation (etch rate per 8 pulses > 2.0 μm) occurred at an energy fluency of 50 mJ/mm² in both normal and fibrous aorta. Tissue damage (carbonization, tissue separation, fissures, cracks, and vacuolization) was in a range of 100 ± 28 to 152 ± 30 μm for normal aorta and in a range of 57 ± 35 to 110 ± 39 μm for fibrous aorta. We conclude that effective ablation of normal and fibrous human aorta can be achieved by the application of smooth excimer laser coronary angioplasty. This improvement of excimer laser technology may result in a reduction of shock wave- and cavitation-induced damage leading to a reduction of tissue injury. However, this awaits further in vitro and in vivo confirmation. © 1993 Wiley-Liss, Inc.     

Possibilities and limitation of prenatal diagnosis and carrier determination for Duchenne and Becker muscular dystrophy using cDNA probes.

Two cDNA probes, cf23a and cf56a, identify deletions of selected exons in about 50% of our DMD/BMD patients. We have estimated the most likely order of the 11 exons detectable with both probes with respect to the different extensions of the deletions. In one of our BMD pedigrees, the observed deletion could be traced in the affected males through three generations. This result shows that with the use of cDNA probes detecting deletions, the only risk of error in genomic prenatal diagnosis is the general high frequency of new mutations for DMD/BMD. This is important progress in diagnosis compared to the 2 to 5% risk of misdiagnosis because of crossing over events using conventional linkage analysis with bridging or intragenic probes. The first prenatal diagnosis of an unaffected fetus of a woman who is a DMD carrier according to ultrasound examination is described. In one of our DMD males, the cDNA probe cf56a detects a deletion breakpoint. His sister also shows the altered band and is therefore a DMD carrier, while his mother has a totally normal band pattern. The interpretation of this observation could be either germline mosaicism or two identical new mutations. The identification of deletion breakpoints is a new diagnostic strategy, especially for carrier determination, which excludes misdiagnosis owing to crossing over events and the problems of dosage estimation. It is, however, limited by the low frequency of breakpoints detectable with cDNA probes. Therefore, the generation of new intron probes in this region is an important goal.     

Autoimmunity and inflammation due to a gain-of-function mutation in phospholipase C gamma 2 that specifically increases external Ca2+ entry

The identification of specific genetic loci that contribute to inflammatory and autoimmune diseases has proved difficult due to the contribution of multiple interacting genes, the inherent genetic heterogeneity present in human populations, and a lack of new mouse mutants. By using N-ethyl-N-nitrosourea (ENU) mutagenesis to discover new immune regulators, we identified a point mutation in the murine phospholipase Cg2 (Plcg2) gene that leads to severe spontaneous inflammation and autoimmunity. The disease is composed of an autoimmune component mediated by autoantibody immune complexes and B and T cell independent inflammation. The underlying mechanism is a gain-of-function mutation in Plcg2, which leads to hyperreactive external calcium entry in B cells and expansion of innate inflammatory cells. This mutant identifies Plcg2 as a key regulator in an autoimmune and inflammatory disease mediated by B cells and non-B, non-T haematopoietic cells and emphasizes that by distinct genetic modulation, a single point mutation can lead to a complex immunological phenotype.     

Relationship of polymorphisms in the renin-angiotensin system and in E-selectin of patients with early severe coronary heart disease

 Previous association studies between angiotensin-converting enzyme (ACE) and angiotensinogen (AGT) polymorphisms and several cardiovascular diseases have reported variable results. Therefore we examined the association of the DNA variants of ACE and AGT with early, severe coronary heart disease (CHD). In addition, we compared the genotypes of both polymorphisms and the recently discovered polymorphism in the E-selectin gene in both patients and an unselected population. This study included 113 patients with severe CHD (50 years old or less) and up to 197 control subjects. The frequencies of the ACE I/D variants were 48% I and 52% D in the controls and 46% I and 54% D in the patients. The frequencies of the AGT-M235T polymorphism were 60.8% M and 39.2% T in controls and 49.1% M and 50.9% T in the patients. The frequencies of the S128R polymorphism of the E-selectin were 91.3% S and 8.7% R in controls and 84.5% S and 15.5% R in the patients. In our studies the DD genotype of ACE was not associated with early severe CHD. We found a correlation between the M235T molecular variant of AGT and the S128R variant of E-selectin to early severe CHD. Received: 15 February 1996 / Accepted: 2 October 1996     

Mucosal immunization with PLGA-microencapsulated DNA primes a SIV-specific CTL response revealed by boosting with cognate recombinant modified vaccinia virus Ankara

Systemically administered DNA encoding a recombinant human immunodeficiency virus (HIV) derived immunogen effectively primes a cytotoxic T lymphocyte (CTL) response in macaques. In this further pilot study we have evaluated mucosal delivery of DNA as an alternative priming strategy. Plasmid DNA, pTH.HW, encoding a multi-CTL epitope gene, was incorporated into poly(D,L-lactic-co-glycolic acid) microparticles of less than 10 microm in diameter. Five intrarectal immunizations failed to stimulate a circulating vaccine-specific CTL response in 2 Mamu-A*01(+) rhesus macaques. However, 1 week after intradermal immunization with a cognate modified vaccinia virus Ankara vaccine MVA.HW, CTL responses were detected in both animals that persisted until analysis postmortem, 12 weeks after the final boost. In contrast, a weaker and less durable response was seen in an animal vaccinated with the MVA construct alone. Analysis of lymphoid tissues revealed a disseminated CTL response in peripheral and regional lymph nodes but not the spleen of both mucosally primed animals.