Second generation shock wave lithotripsy: experience with the Siemens Lithostar

In 1980, extracorporeal shock wave lithotripsy (ESWL) was incorporated as a nonsurgical method of stone removal in the cases of nephrolithiasis and rapidly found worldwide acceptance. Several devices commonly designated "second generation" lithotripters vs "first generation" Dornier HM3 are now under experimental or clinical trial. We report our clinical experience of ESWL using a Siemens Lithostar and compared it with that obtained using a Dornier HM3. One hundred patients were treated during the period of April through October, 1986 using an HM3, and 100 other patients were treated using a Lithostar from April to August, 1988. More cases were treated with a Lithostar than with a HM3. Nearly 10% of all patients treated by ESWL required additional therapeutic approaches (excepted ureteral stent) either with HM3 or Lithostar. However, in the cases of ureteral stone, with the Lithostar more cases required adjuvant procedures (TUL) than HM3. Significantly more shock waves were needed with Lithostar than HM3 for complete fragmentation of the same size of renal and ureteral stones. The stone-free rate during a one month period after ESWL was nearly the same for HM3 and Lithostar (HM3: 84.3%, Lithostar: 83.5%). Lithostar is a multifunctional lithotriptor which has most of the advantages required by the lithotripter.     

Macrophage inflammatory protein 3alpha-CC chemokine receptor 6 interactions play an important role in CD4+ T-cell accumulation in periodontal diseased tissue

The regulatory role of chemokines and chemokine receptors on specific lymphocyte recruitment into periodontal diseased tissue is poorly characterized. We observed that lymphocytes infiltrating inflamed gingival tissue expressed marked levels of CCR6. In periodontal diseased tissue, the expression of MIP-3alpha mRNA was detected by RT-PCR and further, MIP-3alpha was distributed in the basal layer of gingival epithelial cells, microvascular endothelial cells and the areas of inflammatory cells as shown by immunohistochemistry. Moreover, CCR6-expressing cells infiltrated into periodontal diseased tissue, and the proportion of CCR6-positive CD4+ T cells was significantly elevated in periodontal diseased tissue compared with peripheral blood in the same patients. Furthermore, gingival lymphocytes isolated from patients showed migration toward MIP-3alpha in an in vitro chemotaxis assay in which migration was abrogated by specific antibody to CCR6. Thus, these findings suggested that CCR6 and the corresponding chemokine, MIP-3alpha may have an important regulatory role in specific lymphocyte migration into inflamed periodontal tissue.     

Investigation of initial changes in the mouse olfactory epithelium following a single intravenous injection of vincristine sulphate

To investigate initial changes in the olfactory epithelium, vincristine sulphate (VCR) was administered intravenously once to male BALB/c mice on day 1 in comparison with unilateral bulbectomy (UBT). The light and electron microscopy of the olfactory epithelium, nerve and/or bulb with BrdU-morphometry was performed sequentially. Further, whole-body radioluminography was conducted at 1 and 24 hours postdose. Apoptosis and an increased number of mitotic cells with a tendency toward decreasing BrdU-positive olfactory epithelial cell counts were observed in olfactory epithelial cells at 6 hours postdose of VCR and became more pronounced at 24 hours postdose. These changes disappeared on days 4 or 15, but minimal axonal degeneration was seen in the olfactory nerve from day 4 onward. Semiquantitative measurement of VCR levels in the ethmoturbinals elicited high drug retention even 24 hours after administration. In contrast, UBT showed no effect on mitosis and BrdU-positive cell counts at 6 hours postdose, but severe lesions in the olfactory epithelium and nerve were seen on days 2, 4, and/or 15. The above results suggest that the initial event of VCR-induced apoptosis in the mouse olfactory epithelium would be mitotic arrest with high drug retention, unlike that evoked by UBT.     

Pathological changes induced by formaldehyde in open-ended rat tracheal implants preexposed to benzo(a)pyrene

The promotion effects of 0.1% formaldehyde (HCHO) in phosphate-buffered saline (PBS) were tested in rat tracheal implants preexposed to a minimal carcinogenic dose of 468 micrograms benzo(a)pyrene (BAP) released over one month from 865 micrograms BAP-beeswax pellets. At the time of pellet removal, the tracheas were made into open-ended, flow-through, tracheal implants (FTTI), and exposed twice/week to HCHO for 30 weeks. Morphological alterations in the FTTI were monitored biweekly by collection of exfoliated cells from the luminal washings for cytopathologic diagnosis, and periodically by sacrificing animals for histopathology. FTTI exposed to the BAP followed by 30 weeks of HCHO had extensive squamous metaplasia, a high proliferation index of 7.87 [3H]thymidine-labeled cells/mm basement membrane, and foci of moderate and marked atypia. Clear diagnosis of some of the lesions was difficult because of the acute toxic effects of the repeated exposures to HCHO. These effects were seen in the tissues as well as in the exfoliated cells, which attest to the latter as an efficient, non-destructive, method for determining the responses of the tracheas to exposure to toxic and carcinogenic agents. FTTI exposed to BAP followed by twice weekly PBS, had a mostly flattened epithelium, and a low proliferation index (0.39). FTTI exposed to beeswax pellets, followed by the HCHO had a relatively high proliferation index (4.20) in a mucociliary epithelium exhibiting some basal cell hyperplasia. Control FTTI had a normal mucociliary epithelium with a proliferation index of 1.52 [3H]thymidine labeled cells/mm basement membrane.     

Toll-like receptor 9 is expressed on follicle-associated epithelia containing M cells in swine Peyer's patches

The precise distribution and expression of Toll-like receptor (TLR) 9 in gut-associated lymphoid tissues (GALTs) has not been elucidated. In this study, we investigated the expression pattern of TLR9 in adult and neonatal swine GALTs by real-time quantitative PCR, western blot, confocal laser microscopy and flow cytometric analysis. The swine TLR9 gene was preferentially expressed in adult Peyer's patches (Pps) and mesenteric lymph nodes (MLNs), which contained approximately three times higher TLR9 than the spleen. Other tissues exhibited only weak expression of TLR9. In neonatal swine, elevated expression of TLR9 was detected only in MLNs. We firstly showed that highly expressive (TLR9(+)) cells were formed in Pps and MLNs. In addition, TLR9(+) cells were present not only in immune cells such as dendritic cells and B cells but also in follicle-associated epithelia (FAE) including membranous cells (M cells) in Pps. These results suggest that Pps and MLNs provide the host defense with the ability to respond to a variety of bioactive oligonucleotides (ODNs) from bacteria at a conductive site of initial immune responses.     

Polyethylenes Having Well‐Defined Bimodal Molecular Weight Distributions Formed with Bis(phenoxy‐imine) Zr Complexes

Summary: Bis(phenoxy‐imine) Zr complexes with MAO activation can produce polyethylenes with well‐defined bimodal molecular weight distributions. Polymerization behavior indicates that minor changes in the ligand structures can have a significant effect on the modality of the resulting polyethylenes. Although there is no direct relationship between the bimodal catalytic behavior and the structure of a precatalyst complex in solution, a precatalyst complex having a methyl or methoxy group para to the phenoxy‐oxygen inclined to exhibit bimodal behavior whereas that with a pentafluorophenyl group on the imine‐nitrogen displayed unimodal behavior. Polymerization results suggest that bimodal behavior is linked to the presence of two kinds of cationic active species, which arise from different modes of ligand coordination. A qualitative correlation was found between the calculated amounts of possible cationic active species and the uni‐ and bimodal catalytic behavior. Based on the results obtained, we concluded that the bimodal polyethylenes are produced by two kinds of cationic active species having two available cis‐located sites with cis‐N, trans‐O and cis‐N, cis‐O arrangements. The results introduced herein are rare examples of the production of well‐defined bimodal polyethylenes using a single precatalyst.

Bis(phenoxy imine) Zr complexes can produce well‐defined bimodal polyethylenes.     

Expression of synaptotagmin 1 in the taste buds of rat gustatory papillae

Synapses between taste receptor cells and primary sensory afferent fibers transmit the output signal from taste buds to the central nervous system. The synaptic vesicle cycle at the synapses involves vesicle docking, priming, fusion, endocytosis, and recycling. Many kinds of synaptic vesicle proteins participate in synaptic vesicle cycles. One of these, synaptotagmin 1, binds Ca(2+) phospholipids with high affinity and plays a role in Ca(2+) regulated neurotransmitter release in the central and peripheral nervous systems. However, the expression patterns of synaptotagmin 1 in rat taste tissues have not been determined. We therefore examined the expression patterns of synaptotagmin 1 and several cell specific markers of type II and III cells in rat taste buds. RT-PCR assay showed that synaptotagmin 1 mRNA was expressed in circumvallate papillae. In fungiform, foliate, and circumvallate papillae, the antibody against synaptotagmin 1 yielded the labeling of a subset of taste bud cells and intra- and subgemmal nerve processes. Double labeled experiments showed that synaptotagmin 1 positive cells co-expressed type III cell markers, PGP 9.5, and NCAM. Intragemmal nerve processes positive for synaptotagmin 1 co-expressed PGP 9.5. Conversely, all synaptotagmin 1 expressing cells did not co-expressed type II cell markers, PLCbeta2, or gustducin. These results show that synaptotagmin 1 may play some regulatory roles in vesicle membrane fusion events with the plasma membrane at the synapses of type III cells in rat taste buds.     

Low grade malignant peripheral nerve sheath tumour: varied cytological and histological patterns

BACKGROUND: A small number of malignant peripheral nerve sheath tumours (MPNSTs) are low grade, and the nature of these low grade tumours has never been systematically assessed. AIMS: To describe the clinicopathological, immunohistochemical, and ultrastructural features of low grade MPNST and to discuss the main differential diagnoses. METHODS: Four cases of low grade MPNST were studied, including one coexistent with neurofibromatosis type 1. The tumours were analysed with respect to nuclear atypia, cellularity, nuclear enlargement, hyperchromasia, mitotic rate, and necrosis. Immunohistochemistry was performed by standard techniques, and an ultrastructural study was performed on one tumour. RESULTS: The ages of the patients ranged from 32 to 72 years (mean, 58). Two were male and two were female. Three tumours occurred in the deep tissue, including one in the retroperitoneum, and one was located in the dermal and subcutaneous tissue. The maximum diameters of the tumours ranged from 3.5 to 8.0 cm. Microscopically, all tumours showed moderate hypercellularity, an increased nuclear to cytoplasmic ratio, and hyperchromasia, but exhibited varied growth patterns, including those that were atypical neurofibroma-like, low grade fibromyxoid sarcoma-like, low grade epithelioid, and haemangiopericytoma-like. All tumours showed immunoreactivity for S-100 protein and vimentin. CONCLUSIONS: These findings suggest that careful clinical and histological evaluation, along with S-100 protein immunostaining, are essential for the accurate diagnosis of low grade MPNST.     

Synthesis of methyl methacrylate/styrene copolymer bearing a carbomethoxyallyl end group with limited molecular weight by addition-fragmentation reaction of methyl α-(bromomethyl)-acrylate

The synthesis of methyl methacrylate/styrene copolymer bearing overwhelmingly bromine and the 2-carbomethoxyallyl group (CH₂?C(COOCH₃)CH₂? ) at the α- and ω-termini instead of the fragment of the initiator with reduced molecular weight was investigated by using methyl α-(bromomethyl)acrylate as chain transfer agent through the addition-fragmentation mechanism. The molecular weight of the copolymer was effectively decreased with bromomethylacrylate, and the unsaturated end groups quantitatively bound to two types of the monomeric units were differentiated by means of ¹H NMR spectroscopy. Equations estimating the reactivities of methyl α-(bromomethyl)acrylate towards polystyrene and poly(methyl methacrylate) radicals were derived. Methyl α-(bromomethyl)acrylate was found to be more reactive toward the poly(methyl methacrylate) radical than the polystyrene radical by a factor of 0,62.