Allelic imbalance and instability of microsatellite loci on chromosome 1p in human non-small-cell lung cancer

The mapping of allelic loss on the short arm of chromosome 1 has been performed in non-small-cell lung cancer. We used a set of 11 microsatellite loci spanning 1p to examine the frequency of allelic imbalance in a panel of 58 tumours. Fifty-one of 58 (87.9%) cases have shown somatic allelic loss at one or more loci tested. The two shortest regions of the overlap (SRO) of the deletions have been identified: SRO 1 at 1p13.1 and SRO 2 at 1p32-pter. Allelic losses at these regions have been compared among adenocarcinoma and squamous cell carcinoma and no difference has been found. In contrast to SRO 1, deletions at SRO 2 significantly correlated with advanced stage of the disease as well as post-operative metastasizing and relapse. These data may suggest that SRO 1 and SRO 2 can harbour tumour-supressor genes (TSGs) involved in different stages of NSCLC development. SRO 2 is still quite large and its refined mapping should help attempts to clone and identify the putative TSG(s). Microsatellite instability (replication errors) affecting only 6 (10.3%) of 58 tumour samples is an infrequent genetic alteration at the loci tested.     

Urologic complications after simultaneous pancreas-kidney transplantation: hand-sewn versus stapled duodenocystostomy

Pancreas transplantation with bladder drainage of exocrine secretions may be associated with significant urologic complications. Stapled and hand-sewn duodenocystostomies were compared in 61 recipients of simultaneous pancreas-kidney transplants. Both methods resulted in similar urologic complication and allograft survival rates. Duodenal segment leaks were associated with significant morbidity and decreased patient and allograft survival.     

Pharmacokinetics of d-limonene in the rat by GC-MS assay

The naturally occurring monoterpene d-limonene has been found to inhibit various stages of tumorigenesis in a number of animal models and is now being evaluated as a chemopreventive agent in humans. To date, there are little or no preclinical pharmacokinetics available nor is there a sensitive assay methodology. In this study, d-limonene and its dideuterium-labeled internal standard, limonene-d2, in whole rat blood were extracted with n-pentane which was then concentrated on a Kuderna-Danish concentrator. The residue was analyzed by an ion-trap GC -MS under ammonia chemical ionization. The detection limit of d-limonene was 1.0 ng if injected in pure form; however, due to the presence of endogenous d-limonene levels (probably from diet), the routine quantitation limit was set at 1.0 microgram ml-1. The monitored assay linearity range from 1.0 to 30 micrograms ml-1 within-day CV values of 8.0%, 2.4%, and 2.0% at 1.0, 3.0 and 10.0 micrograms ml-1, respectively (all at n = 8), and corresponding accuracy of 100%, 100%, and 101%. The between-day CV values were 12.3, 8.0, and 7.5% at 1, 6, and 20 micrograms ml-1, respectively (all at n = 8). Using this assay, pharmacokinetics of d-limonene were studied in Sprague-Dawley rats following intravenous and oral administration at 200 mg kg-1 each. Blood concentration-time profiles after intravenous administration showed a biphasic decline with a mean initial t1/2 of 12.4 min and a terminal t1/2 of 280 min. The plasma:red blood cell partition was found to be 0.84. Plasma protein binding of d-limonene was found to be 55.3% at 20 microgram ml-1. The mean total clearance was 49.6 ml min-1 kg-1, the volume of distribution at steady-state 11.7 1 kg-1, and median residence time 263 min. The blood concentration-time decline following oral administration also showed a biphasic decline with a mean initial t1/2 of 34 min and terminal t1/2 of 337 min. The oral bioavailability of d-limonene was 43.0%.     

An epidemiological profile of elderly suicides in Hong Kong

Suicide rates in Hong Kong increased with age, and the highest suicide rate occurred among the oldest age groups. Hong Kong has one of the highest elderly suicide rates in the world. The elderly suicide rate was four to five times above the average. Furthermore, gender differences were observed among different marital status groups. For example, single males had a much higher rate than single females and married males had a higher rate than their widowed counterparts. The suicide rate for an economically inactive person was six times higher than for an active one. Jumping has become increasingly common and seems to substitute for other methods of suicide. Winter months and the Chinese New Year period had the lowest suicide occurrence. Some explanations are given.     

Suppression of mouse skin tumor promotion and induction of apoptosis in HL-60 cells by Alpinia oxyphylla Miquel (Zingiberaceae)

There have been considerable efforts to search for naturally occurring substances for the intervention of carcinogenesis. Many components from dietary or medicinal plants have been identified that possess substantial chemopreventive properties. An example is curcumin (Curcuma longa Linn., Zingiberaceae), which has been shown to inhibit tumor promotion in experimental carcinogenesis. Alpinia oxyphylla Miquel, another plant of the ginger family used in oriental herbal medicine, contains diarylheptanoids whose structures are analogous to that of curcumin. In the present study, we have tested A.oxyphylla for its ability to suppress tumor promotion. Thus, topical application of the methanolic extract of dried fruits of A.oxyphylla significantly ameliorated 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin tumor promotion as well as ear edema in female ICR mice. In another study, treatment of HL-60 cells with the methanolic extract of A.oxyphylla significantly reduced the viability of the cells and also inhibited DNA synthesis. Microscopic examination of the treated cells showed characteristic morphology of apoptosis. Furthermore, cells treated with the extract of A.oxyphylla exhibited internucleosomal DNA fragmentation in time- and concentration-dependent manners. TPA-stimulated generation of superoxide anion in differentiated HL-60 cells was also blunted by A.oxyphylla. Taken together, these findings suggest that A.oxyphylla possesses potential chemopreventive and antitumorigenic activities.     

Imipramine metabolism in relation to the sparteine and mephenytoin oxidation polymorphisms--a population study

1. Sparteine and mephenytoin phenotyping tests were carried out in 327 healthy Danish subjects. Two weeks later each subject took 25 mg imipramine followed by urine collection for 24 h. The urinary content of imipramine, desipramine, 2-hydroxy-imipramine and 2-hydroxy-desipramine was assayed by h.p.l.c. 2. The medians of the hydroxylation ratios (i.e. 2-hydroxy-metabolite over parent compound) were 6 to 14 times higher in 300 extensive metabolizers of sparteine (EMs) as compared with 27 poor metabolizers (PMs), but none of the ratios separated the two phenotypes completely. 3. There were 324 EM of mephenytoin (EMM) and three PM (PMM) in the sample. The demethylation ratios between desipramine, 2-hydroxy-desipramine and their corresponding tertiary amines showed statistically significant correlations with the mephenytoin S/R isomer ratio (Spearman's rs: -0.20 and -0.27, P < 0.05). 4. The demethylation ratios were higher in 80 smokers than in 245 non-smokers. This indicates that CYP1A2, which is induced by cigarette smoking, also catalyzes the N-demethylation of imipramine. 5. CYP2D6 genotyping was carried out by PCR in 325 of the subjects, and the D6-wt allele was amplified in 298 EMs, meaning that they were genotyped correctly. One PMs was D6-wt/D6-B, another PMs had the genotype D6-wt/ and hence both were misclassified as EMs. The remaining 25 PMs were D6-A/D6-B (n = 5), D6-B/ (n = 18) or D6-D/D6-D (no PCR amplification, n = 2).(ABSTRACT TRUNCATED AT 250 WORDS)     

Targeted replacement of normal and mutant CFTR sequences in human airway epithelial cells using DNA fragments

Recent studies have reported that mutant genomic cystic fibrosis (CF) transmembrane conductance regulator ( CFTR ) sequences can be corrected in transformed CF airway epithelial cell lines by targeted replacement with small fragments of DNA with wild-type sequence. To determine if the observed genotype modification following small fragment homologous replacement (SFHR) was limited to transformed CF cell lines, further studies were carried out in both transformed and non-transformed primary normal airway epithelial cells. The endogenous genotype of these normal cell lines was modified following liposome or dendrimer transfection using DNA fragments with DeltaF508 CFTR sequence (488 nt, complementary single strands) designed to also contain a unique restriction enzyme cleavage site (Xho I). Replacement at the appropriate genomic locus by exogenous DeltaF508 CFTR DNA and its expression as mRNA was demonstrated by PCR amplification of genomic DNA and mRNA-derived cDNA as well as Xho I digestion of the PCR products. These studies show that SFHR occurs in both transformed and non-transformed primary human airway epithelial cells and indicate that single base substitution (the silent mutation giving rise to the Xho I site) and deletion or insertion of at least three consecutive bases can be achieved in both normal and CF epithelial cells. Furthermore, these studies reiterate the potential of SFHR as a strategy for a number of gene targeting applications, such as site-specific mutagenesis, development of transgenic animals, development of isogenic cell lines and for gene therapy.     

Functional anatomy of the cartilage of the distal phalanx and digital cushion in the equine foot and a hemodynamic flow hypothesis of energy dissipation

OBJECTIVES: To examine macro- and microscopic characteristics of cartilage of the distal phalanx (ungual cartilage [UC]) and digital cushion in the equine foot and to relate them to the foot's function of energy dissipation. ANIMALS: 85 horses and 5 foals of various breeds and ages. PROCEDURE: Feet, obtained at necropsy, were perfused with India ink (n = 30), latex (5), or polymer plastic (10). Select feet were examined histologically for tissue architecture and to identify elastic fibers. Immunochemistry to identify substance P peptides in nerves (feet from foals) and gold chloride impregnation of axons (n = 10) were performed. Feet were sectioned transversely (n = 27) or coronally (62 feet in a matched-paired study). Ungual cartilage was measured at the navicular bone. Digital cushions were examined for relative tissue composition between forefeet and hind feet. RESULTS: Ungual cartilage formed an axial projection that extended towards the midline to overlie the bars, and dorsally along the semilunar line of the distal phalanx. Ungual cartilage of forefeet was significantly larger than that of hind feet. The digital cushion was composed of fat and elastic tissues in feet with thin UC, or fibrous and fibrocartilaginous tissue and elastic tissue in feet with thicker UC. Sensory nerves and an extensive network of venovenous anastomoses were found in the UC. CONCLUSIONS AND CLINICAL RELEVANCE: Ungual cartilage and the digital cushion provide the basis for a hemodynamic flow hypothesis of energy dissipation. Maximum energy dissipation depends on proper hoof preparation and shoeing.     

Ca2+-dependent structural changes in C-type mannose-binding proteins

C-type animal lectins are a diverse family of proteins which mediate cell-surface carbohydrate-recognition events through a conserved carbohydrate-recognition domain (CRD). Most members of this family possess a carbohydrate-binding activity that depends strictly on the binding of Ca2+ at two sites, designated 1 and 2, in the CRD. The structural transitions associated with Ca2+ binding in C-type lectins have been investigated by determining high-resolution crystal structures of rat serum mannose-binding protein (MBP) bound to one Ho3+ in place of Ca2+, and the apo form of rat liver MBP. The removal of Ca2+ does not affect the core structure of the CRD, but dramatic conformational changes occur in the loops. The most significant structural change in the absence of Ca2+ is the isomerization of a cis-peptide bond preceding a conserved proline residue in Ca2+ site 2. This bond adopts the cis conformation in all Ca2+-bound structures, whereas both cis and trans conformations are observed in the absence of Ca2+. The pattern of structural changes in the three loops that interact with Ca2+ is dictated in large part by the conformation of the prolyl peptide bond. The highly conserved nature of Ca2+ site 2 suggests that the transitions observed in MBPs are general features of Ca2+ binding in C-type lectins.