Search

Br J Sports Med 2004;38:163-167. doi: 10.1136/bjsm.2002.002899 Objective: To examine the test-retest reliability of a protocol using an apparatus designed to standardise the standing heel rise test for the triceps [...]

Backgrounds Data from large, multicenter, US studies determining the efficacy of triple therapy for the eradication of Helicobacter pylori are lacking, especially for a treatment duration of less than 14 days. Methods: Patients with H pylori infection and active duodenal ulcer disease or a history of duodenal ulcer disease within the past year were randomized to receive 30 mg of lansoprazole, 1 g of amoxicillin, and 500 mg of clarithromycin twice daily for 10 or 14 days. The primary efficacy end point was the eradication of H pylori as confirmed by negative histological and culture results at 4 to 6 weeks after the completion of treatment. Results: Of 284 patients enrolled in the study from 46 US sites, 236 met the entry criteria. At 4 to 6 weeks after the end of therapy, H pylori was eradicated in 85% (96/113) of the patients receiving 14-day triple therapy and in 84% (103/123) of those receiving 10-day triple therapy by per-protocol analysis (95% confidence interval for treatment group differences, -10.5 to 8.1; P [is less than] .05). There was also no significant difference between the 14- and 10-day treatment groups when analyzed by an intent-to-treat analysis of H pylori eradication. A similar proportion of patients in each treatment group reported an adverse event related to therapy (34% [46/136] vs 38% [56/148], respectively). Conclusions: In patients with an active or a recent history of duodenal ulcer, lansoprazole-based triple therapy for 10 or 14 days is highly effective in the eradication of H pylori. The duration of therapy may be reduced from 14 to 10 days without a significant effect on regimen efficacy. Arch Intern Med. 1998;158:1651-1656

A primary intimal aortic angiosarcoma was diagnosed in a 4-year-old, spayed female German Shepherd that presented for complications of thromboembolic disease because of infarcts in multiple organs. On gross examination, aneurysmal dilatation of the aorta was associated with a friable, necrotic mass attached to the endothelial surface, which partially occluded the aortic lumen. On histologic examination, plump neoplastic spindle cells formed a plaque-like mass arising from the intima that merged with a large accumulation of fibrin and necrotic debris, and projected into the lumen. Neoplastic cells invaded periaortic vessels and were seen in some infarct-associated thromboemboli. Tumor cells expressed vimentin and CD31, with infrequent, patchy staining with factor VIII-related antigen; tumor cells were negative for cytokeratin and smooth-muscle actin. Aortic angiosarcoma is a rare malignancy in humans. This is the first description of a primary intimal aortic angiosarcoma in a dog, with immunohistochemical evidence of endothelial origin.

Graduated elastic compression stockings (ECS) are often prescribed after deep venous thrombosis (DVT) to alleviate acute symptoms and to prevent and treat post-thrombotic syndrome (PTS). In patients with DVT, leg symptoms tend to worsen with exercise. The effects of ECS use during exercise have not been studied. Objectives were to determine whether ECS improve symptoms and signs and increase exercise capacity when worn during treadmill exercise by patients with prior DVT, with or without PTS. The methods employed a randomized cross-over trial. We recruited subjects who had a first episode of unilateral DVT at least 1 year earlier and categorized them as having, or not having, the PTS using a validated scale. Subjects underwent two identical treadmill exercise sessions at least 1 week apart, and were randomly assigned to wear knee-length 30 mmHg ECS on the affected leg during one of the two sessions. Venous symptoms, leg volume, leg circumference and calf muscle flexibility were measured in the affected leg before and after both exercise sessions. Subjects achieved similar percentage maximum predicted heart rates during both sessions. Comparing the ECS to no ECS session, there were no significant differences in treadmill time (21.2 vs. 21.2 min, P = 0.94), gain in leg volume (71 vs. 73 mL, P = 0.83), or change in soleus or gastrocnemius flexibility, whether or not PTS was present. Symptoms in general worsened slightly with exercise regardless of whether or not ECS were worn and did not differ according to PTS status. Per-subject analysis showed that use of ECS resulted in global improvement of symptoms in 25% of subjects, global worsening in 33% of subjects, and had no or inconsistent effects in 42% of subjects. Whether or not PTS was present, the use of ECS during exercise by patients with prior DVT did not improve symptoms and signs during exercise or increase exercise capacity.

To determine the nature and frequency of cognitive impairments in nondemented patients with advanced PD and their relationship to other variables potentially predictive of neuropsychological performance.

To evaluate the neuropsychological and psychiatric sequelae of unilateral posterior pallidotomy for treatment of PD.

Submicroscopic evidence of persistent minimal residual disease (MRD) in first remission bone marrow samples from children with acute lymphoblastic leukaemia (ALL) indicates a high risk of clinical relapse. Since microscopic evidence of leukaemic lymphoblasts is often present in the peripheral blood in the weeks before clinical presentation at diagnosis or relapse, peripheral blood may be used instead of bone marrow to detect MRD in ALL patients. We examined a median of 0·165 μg (from 1·0–2·0×104cells) genomic DNA from archived peripheral blood smears collected 8–16 months prior to clinical relapse in eight children with ALL for evidence of MRD. We used the polymerase chain reaction and primers designed to identify clonal antigen receptor gene rearrangements. Among the seven patients with bone marrow relapse, MRD was detected at a median of 1·2 months (0–8 months) prior to clinical relapse, indicating that MRD in the peripheral blood may be a late event in the course of leukaemic relapse. A prospective MRD study in ALL patients analysing larger numbers of peripheral blood cells will be needed to evaluate the utility of peripheral blood over bone marrow for MRD testing in childhood ALL.

We have recently shown that high-level expression of the multidrug resistance-associated protein (MRP) gene is a powerful independent predictor of poor outcome in neuroblastoma. The clinical implication of these findings is that MRP modulators may prove therapeutically useful. We therefore investigated the ability of difloxacin, a quinolone antimicrobial antibiotic, to increase drug cytotoxicity in unselected cultured human neuroblastoma cells. Drug cytotoxicity was determined using a microtiter assay in neuroblastoma cells expressing low (SH-EP), intermediate (NBL-S), or high [BE(2)-C] levels of MRP. Difloxacin (50 μg/ml) increased sensitivity to the MRP substrates, vincristine, doxorubicin, daunorubicin, and potassium antimony tartrate to an extent directly proportional to their level of MRP expression. No change in the response to cisplatin, which is not a substrate for MRP, was observed in any of the cell lines. The data demonstrate that difloxacin can reverse drug resistance in unselected human neuroblastoma cells and is therefore a potential candidate for future clinical trials. Med. Pediatr. Oncol. 36:177–180, 2001. © 2001 Wiley-Liss, Inc.

The recently characterised p53 homologue, p73, has been mapped to chromosome 1p36, a region often found deleted in neuroblastoma. Although p73 has been implicated as a candidate tumour suppressor for neuroblastoma, mutations in the gene appear to be rare, thus suggesting other mechanisms for its aberrant behaviour. We analysed p73 gene expression in a panel of primary neuroblastoma tumours and cell lines, as well as other tumours of childhood, using a reverse transcriptase-polymerase chain reaction assay. Although low-level p73 expression was detected in 44/45 primary neuroblastoma tumours, no association with prognostic markers could be discerned. In no case was the level of p73 expression in the primary tumours as high as that observed in p73-expressing neuroblastoma cell lines. Expression of the p73 gene was also detected in 24/34 other childhood tumours. Collectively, the data raise doubts over the role of this gene as a tumour suppressor in neuroblastoma. Med. Pediatr. Oncol. 36:48–51, 2001. © 2001 Wiley-Liss, Inc.

Although the association between N-myc gene amplification and poor clinical outcome in neuroblastoma is well established, the mechanism by which amplification influences prognosis is not well defined. We used a human N-myc transgenic mouse model to investigate the role of N-myc in neuroblastoma, including its relationship to the multidrug-resistance-associated protein (MRP) gene. We developed a rapid real-time PCR method to distinguish homozygous and hemizygous N-myc mice that is comparable to Southern analysis. A highly significant correlation (P < 0.0001) between N-myc and MRP expression was demonstrated in murine tumors. Amplification of the transgene was observed in the majority of tumors, highlighting the clinical relevance of this model. However, no correlation between N-myc expression and transgene dosage or tumor latency was observed. The data suggest that increased N-myc dosage contributes to increased tumor incidence and decreased latency by mechanisms independent of N-myc expression. Med. Pediatr. Oncol. 35:585–589, 2000. © 2000 Wiley-Liss, Inc.

Determination of N-mycgene amplification, a powerful prognostic indicator in the childhood tumour, neuroblastoma, has routinely been performed by Southern analysis. We have developed a differential polymerase chain reaction (PCR) assay, in which the N-myctarget gene is co-amplified with a control gene, glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Following electrophoresis, a ratio between the two PCR products within a given DNA sample is then determined by densitometry. This assay was applied to DNA isolated from 32 primary neuroblastoma tumours for which the N-mycstatus had previously been determined by Southern analysis. Following PCR, samples containing a single copy of the N-myconcogene were clearly distinguishable from samples with N-mycgene amplification, based on an N-myc/GAPDH ratio of below or above 1·0, respectively. Linear regression indicated a highly significant relationship (R = 0·94; P < 0·001) between N-myccopy number (Southern) and N-myc/GAPDH ratio (PCR). Serial dilution of N-mycamplified DNA with non-amplified control DNA indicated that the PCR assay was sufficiently sensitive to detect two-fold amplification. Moreover, such serial dilution allowed determination of N-myccopy number. The assay, which requires only small amounts of tissue and does not utilize 32P-radioactivity, therefore provides a rapid and sensitive alternative to Southern analysis.

AimsTo determine the role of polymerase chain reaction (PCR) based minimal residual disease (MRD) detection of leukaemia specific DNA in testicular relapse in childhood acute lymphoblastic leukaemia.MethodsDNA was obtained from archival testicular and bone marrow samples from boys with acute lymphoblastic leukaemia who relapsed in the testes. Overlapping DJ_H clone specific primers derived from clonal immunoglobulin heavy chain (IgH) gene rearrangement in each case were used to analyse testicular or bone marrow DNA.ResultsHistologically normal end of treatment testicular biopsies in the five patients in longterm remission were all MRD negative, but MRD positive in three of six boys with subsequent testicular relapse. Histologically normal bone marrow samples taken at the end of treatment were MRD negative in five of seven cases, but MRD positive in all cases at the time of isolated testicular relapse. Three boys with unilateral testicular relapse underwent unilateral orchidectomy, rather than bilateral testicular irradiation, as part of their treatment. Two of these boys were MRD positive in the histologically uninvolved testes, and both had subsequent relapses either in the testes or the bone marrow, while the MRD negative patient has not had a testicular relapse.ConclusionsThe presence of MRD in testicular tissue can be assayed with a PCR based method to detect clone specific antigen receptor gene rearrangements. In this setting, PCR is more sensitive than conventional testicular histology for predicting clinical outcomes. MRD assays might be useful in the management of boys at the time of isolated testicular relapse, to confirm the presence of unilateral testicular disease.

In 1915, Greenwood and Yule noted that for valid vaccine efficacy studies, exposure to infection in the vaccinated and the unvaccinated must be equal (Proc R Soc Med 1915;8(part 2):113-94). The direct effect of a vaccine, however, needs to be defined by the protection it confers given a specific amount of exposure to infection, not just a comparable exposure. In this paper, two classes of parameters are distinguished along lines differing from the conventional distinction between efficacy and effectiveness. Efficacy parameters attempt to control for exposure to infection and represent direct effects on individuals. Direct effectiveness parameters represent a mixture of direct effects on individuals and indirect effects in the population.

Glutathione, a tripeptide found in a variety of foods, may function as an anticarcinogen by acting as an antioxidant and by binding with cellular mutagens. The association between dietary glutathione intake and risk of oral and pharyngeal cancer was investigated using data from 1,830 white participants (855 cases and 975 controls) in a population-based case-control study conducted in New Jersey; metropolitan Atlanta, Georgia; Los Angeles County, California; and Santa Clara and San Mateo counties, south of San Francisco-Oakland, California, during 1984-1985. The estimated relative risk of cancer among people with the highest quartile of glutathione intake from all sources was 0.5 (95% confidence interval 0.3-0.7). When analyzed by dietary source, however, glutathione intakes derived from all vegetables and from meat were not related to risk of cancer. Only glutathione derived from fruit and from vegetables commonly consumed raw was associated with reduced oral cancer risk. Relative to the lowest level of combined intake of fruit and of fruit-derived glutathione, risk of cancer decreased slightly with increasing intake of fruit glutathione. This analysis was limited, however, by the small numbers of subjects with extreme combinations of intakes. Further studies are needed to distinguish the potential effect of glutathione from that of fruit and raw vegetables per se or from the influence of other constituents in these foods.

Strain BALB/c female mice bearing syngeneic implants of 2 mammary adenocarcinomata were treated with MER, x-irradiation or both. MER was administered either subcutaneously at a site contralateral to the neoplastic growth or both into such a site and directly at the tumour location. None of the treatments effected cures but many of the treated animals survived significantly longer than did the saline injected controls. There was no evidence that introduction of MER into, or directly adjacent to, a tumour is a generally more efficacious route of administration than application at only a distal site and there was, indeed, the strong contrary impression that distal treatment alone bestowed survival protection more often and to a greater extent. In no instance was there a shortening of survival time following administration of MER at a location away from the tumour implant.

The asymptotic power of the frequency χ2test depends on a noncentrality parameter, λ,Mitra[1958] offered a general expression for λ, which is rather difficult to apply. This work provides simplified formulae for λ in various models associated with multidimensional contingency tables.

A common source of bias in evaluating vaccine efficacy following a disease outbreak is the presence of persons who had the disease prior to the outbreak. This paper examines the effects of including and excluding pre-outbreak disease cases from the calculation of vaccine efficacy based on the cumulative incidence at the end of an outbreak. Using a five-stage model, the effects of the following factors on the bias of vaccine efficacy estimates are examined: the true protective efficacy of the vaccine, the prevaccination infection rate, differences in vaccine uptake among the previously diseased and nondiseased, differences in pre-outbreak exposure to infection between vaccinees and nonvaccinees, and differences in exposure during the outbreak between vaccinees and nonvaccinees. Numerical calculations of the bias are performed for a hypothetical outbreak of measles in a developing country. Exclusion of pre-outbreak disease cases requires accurate data on disease rates prior to the outbreak, and such data are often unreliable or nonexistent. Inclusion of pre-outbreak cases contributes to the bias of the estimated vaccine efficacy, especially when there is a high prevaccination infection rate and vaccine uptake among the previously diseased is considerably lower than that among the nondiseased. In most practical cases, however, this bias is not very large.

Specific germline mutations in theRETproto-oncogene predispose to the familial cancer syndromes: multiple endocrine neoplasia (MEN) types 2A and 2B, and familial medullary thyroid carcinoma. Expression of the RET receptor tyrosine kinase is tightly restricted to tumours of neural crest origin, such as neuroblastoma, and neuroblastoma has been observed inRETtransgenic mice. Neuroblastoma tumour cell lines transfected with the MEN2ARETgene exhibit spontaneous neuritic differentiation, whereas MEN2B-typeRETtransfectants demonstrate altered cell adhesion and enhanced metastatic potential. In this study, the authors examined genomic DNA from 26 primary neuroblastoma tumours for MEN2A and MEN2BRETmutations, using restriction enzyme digestion of polymerase chain reaction products as an alternative to direct sequencing. Examination ofRETexons 10 (codons 611, 618, 620), 11 (codons 632, 633, 634) and 16 (codon 918) in all 26 tumours revealed noRETmutations. Taken together these data suggest that abnormalities of the RET signalling pathway, rather than oncogenic, MEN2-typeRETactivation by mutation, may play a role in neuroblastoma tumorigenesis.

Two multidrug-resistant human leukemic CCRF-CEM sublines (CEM/VCR R and CEM/VLB100) were significantly more resistant to tetracycline, a hydrophilic antibiotic, than parental cells (P < 0.001). Verapamil and cyclosporin A completely reversed tetracycline resistance in CEM/VCR R cells, which also accumulated and retained significantly less [3H]tetracycline than CCRF-CEM cells. Like verapamil, addition of tetracycline to CEM/VCR R cells which had achieved steady-state vincristine levels resulted in augmented vincristine accumulation. [3H]Azidopine photoaffinity labelling of CEM/VCR R membrane proteins was inhibited by tetracycline in a dose-dependent manner. Although drugs associated with the multidrug-resistance phenotype are typically hydrophobic compounds, these data suggest that resistance to tetracycline, despite its hydrophilic nature, is mediated by P-glycoprotein in these cell lines.

The ability of three pure types of bovine brain phospholipase C (PLC) and one pure rat liver PLC to utilize as substrates the recently discovered phosphatidylinositol 3-phosphate (PI-3-P), a putative phosphatidylinositol 3,4-bisphosphate (PI-3,4-P2), and phosphatidylinositol trisphosphate (PIP3) was investigated. PI-3-P, PI-3,4-P2, and PIP3 are the products of phosphorylation of PI, PI-4-P, and PI-4,5-P2, respectively, by phosphoinositide 3-kinase activities that are associated with certain protein-tyrosine kinases. Although these new phospholipids have been found in intact cells, PI-3,4-P2and PIP3 appear only after stimulation of quiescent cells with growth factors such as platelet-derived growth factor (Auger, K. R., Serunian, L. A., Soltoff, S. P., Libby, P., and Cantley, L. C. (1989) Cell57, 167-175) and after transformation by certain oncoproteins (L. A. Serunian, K. R. Auger, T. M. Roberts, and L. C. Cantley, manuscript in preparation). Mixtures of [3H]PI-4-P plus [32P]PI-3-P or [3H]PI-4,5-P2plus [32P]PI-3,4-P2or PIP3alone were used as substrates for PLCs in vitro. After incubation with enzyme followed by extraction with chloroform/methanol/HCl, the ratio of 3H/32P in the aqueous layer revealed the selective hydrolysis of PI-4-P and PI-4,5-P2over PI-3-P and PI-3,4-P2. High performance liquid chromatography analysis of the aqueous layer containing reaction products confirmed that only PI-4-P and PI-4,5-P2, were hydrolyzed to inositol 1,4-P2and inositol 1,4,5-P3, respectively. These findings suggest that the turnover of PI-3-P, PI-3,4-P2, and PIP3 occurs independently of the turnover of PI-4-P and PI-4,5-P2.

Assuming equality of genotypic effects over different loci, this paper provides an ML procedure for estimating genetic parameters for quantitative traits from autotetraploid self‐fertilized populations. The results are illustrated by computer generated data involving P1, P2, F2, B1and B2populations.

Recently, the mechanism of autoprocessing of the protease (PR) of the human immunodeficiency virus type 1 from the model polyprotein, MBP-DeltaTF-PR-DeltaPol, which contains the protease linked to short native flanking sequences (DeltaTF and DeltaPol) fused to the maltose binding protein (MBP) of Escherichia coli, was reported (Louis, J. M., Nashed, N. T., Parris, K. D., Kimmel, A. R., and Jerina, D. M. (1994) Proc. Natl. Acad. Sci. U. S. A. 91, 7970-7974). According to this mechanism, intramolecular cleavage of the N-terminal strands of the dimeric MBP-DeltaTF-PR-DeltaPol protein leads to the formation of the PR-DeltaPol intermediate, which is subsequently converted to the mature protease by cleavage of the C-terminal strands. We now report the purification and characterization of the PR-DeltaPol intermediate and the kinetics of its processing to the mature protease. Unlike the MBP-DeltaTF-PR-DeltaPol precursor, PR-DeltaPol has proteolytic activity similar to that of the mature enzyme at pH 5.0. The pH rate profile for kcat/Km is similar to that of the mature protease above pH 4.0. Although the PR-DeltaPol is more sensitive than the mature protease toward denaturing reagents, both the enzymatic activity and the intrinsic fluorescence of PR-DeltaPol are linearly dependent on the protein concentration, indicating that the protein is largely in its dimeric form above 10 nM. In contrast to the first-order kinetics observed for the proteolytic reaction at the N terminus of the protease, the proteolytic reaction at the C terminus of the protease is second order in protein concentration. These results are discussed in terms of a mechanism in which the C-terminally located DeltaPol peptide chains are cleaved intermolecularly to release the mature protease.

Interpretation and estimation of vaccine efficacy is complicated when the vaccine effect is heterogeneous across vaccinated strata. If a person has a certain susceptibility, or probability of becoming infected conditional on a specified exposure to infection, then one effect of a vaccine would be to reduce that susceptibility, possibly to zero. Vaccine efficacy is a function of the relative susceptibilities in the vaccinated and unvaccinated persons. Under heterogeneity of vaccine effect, a general expression for a summary vaccine efficacy parameter is a function of the vaccine efficacy in the different vaccinated strata weighted by the fraction of the vaccinated subpopulations in each stratum. Interpretation and estimability of the summary vaccine efficacy parameter depends on whether the strata are identifiable, and whether the heterogeneity is host- or vaccine-related. Bounds are derived for the summary vaccine efficacy when the strata are not identifiable for the case of an outbreak of an acute infectious disease. The upper bound assumes that everyone is equally affected by the vaccine, and the lower bound assumes that some are completely protected while others have no protection. The biologic interpretation of the two bounds is different.

A statistical model is presented for the analysis of infectious disease data from family studies in the community. The model partitions the sources of infection into those from within the household and those from the community at large. The parameters reflecting these sources of infection are estimated as functions of the risk factors. This new model is used to overcome problems associated with the lack of independence of observations in infectious disease data and negative confounding due to the association of unmeasured exposures and immunity. An example of how this new statistical model is used to provide a clearer and less confounded description of risk factor effects is presented for data from influenza A(H3N2) epidemic seasons in the Tecumseh Respiratory Illness Study. The risk factors examined are age and pre-epidemic season antibody level as measured by the hemagglutination-inhibition test, while the outcome is the infection rate. A standard analysis of the data indicates that the efficacy of protective antibodies is 70% in children and only 47% in adults. However, such an efficacy measurement is negatively confounded by past exposure which is age dependent. By means of the model, the true, unconfounded, efficacy of protective antibodies is shown to be 90% in both adults and children.

1-Alkylpyrano[3,4-b]indol-3-ones3 react via a Diels-Alder step with an aryne or N-phenylmaleimide to furnish the new [b]annellated carbazoles4–10 in a one-pot process. In an analogous procedure, the in situ generated N-benzoylindole-2,3-quinodimethane (13) reacted with quinones to furnish the dioxocarbazoles14–16. Compounds4–8 and14–16 with a coplanar skeleton are members of a class of potential DNA intercalators, as has been shown for5 and8 by X-ray structural analysis. On the basis of the geometries determined by X-ray crystallography, the intercalative binding of these molecules with a Watson-Crick mini-helix was predicted by molecular modeling methods.

To determine the specificity of neuroendocrine protein gene product (PGP9.5) gene transcripts for detecting micrometastatic neuroblastoma, we have used a highly sensitive polymerase chain reaction (PCR) technique to evaluate expression of this gene in normal blood and bone marrow. While expression of the tyrosine hydroxylase gene was not detected in any normal sample, low-level PGP9.5 expression was detected in eight out of ten blood and seven of 12 marrow samples. PGP9.5 gene transcripts in normal tissues have the potential to interfere with the detection of micrometastatic neuroblastoma.

IN the course of analysis of human bile for the presence of mucosaccharide and deoxyribose-reacting material by the diphenylamine reaction1,2, an unusual peak at 650 mµ was found. It was thought possible that this peak might be due to the yellow-green colour of bile, resulting from the presence of high concentrations of bilirubin and other pyrrolic breakdown products. This possibility was checked using pure bilirubin, deoxyribonucleic acid (DNA), and a mixture of bilirubin and DNA (Fig. 1). It can be seen that a solution of bilirubin (after heating at 90° C with 5 per cent trichloroacetic acid (TCA)) produces a peak at 650 mµ on boiling for 20 min with the diphenylamine reagent. DNA gives a peak at 600 mµ under the same conditions, whereas a mixture of bilirubin and DNA gives a peak at 620 mµ The extinctions of DNA and bilirubin appear to be additive. Bilirubin also interferes in the Burton3procedure for deoxyribose, producing a strong green colour.

A PRONOUNCED sex difference was found to exist in the renal tubules of rats injected intravenously with minimally toxic doses of bichloride of mercury. Mercury, in toxic doses, produces an acute tubular necrosis in a wide variety of experimental animals and man1,2. Histologically, when minimally toxic doses are given to rats, the lesions are confined to the straight portions of the proximal tubules.