Cloning of the Arabidopsis RSF1 gene by using a mapping strategy based on high-density DNA arrays and denaturing high-performance liquid chromatography

Mapping genes by chromosome walking is a widely used technique applicable to cloning virtually any gene that is identifiable by mutagenesis. We isolated the gene responsible for the recessive mutation rsf1 (for reduced sensitivity to far-red light) in the Arabidopsis Columbia accession by using classical genetic analysis and two recently developed technologies: genotyping high-density oligonucleotide DNA array and denaturing high-performance liquid chromatography (DHPLC). The Arabidopsis AT412 genotyping array and 32 F(2) plants were used to map the rsf1 mutation close to the top of chromosome 1 to an interval of approximately 500 kb. Using DHPLC, we found and genotyped additional markers for fine mapping, shortening the interval to approximately 50 kb. The mutant gene was directly identified by DHPLC by comparing amplicons generated separately from the rsf1 mutant and the parent strain Columbia. DHPLC analysis yielded polymorphic profiles in two overlapping polymorphic amplicons attributable to a 13-bp deletion in the third of five exons of a gene encoding a 292-amino acid protein with a basic helix-loop-helix (bHLH) domain. The mutation in rsf1 results in a truncated protein consisting of the first 129 amino acids but lacking the bHLH domain. Cloning the RSF1 gene strongly suggests that numerous phytochrome A-mediated responses require a bHLH class transcription factor.

Introducing nurse telephone triage into primary care

In this article, the authors describe the changes required to introduce a nurse telephone triage system into a large primary care practice in York. 'Whole systems' changes were necessary in that not one element of the primary healthcare team (PHCT) system has remained unaffected. The introduction of nurse triage has changed working practices, professional working relationships and job satisfaction. Far from being just a workload management solution, it has fundamentally altered the way that nurses, doctors and reception staff work together and with patients.

Symptom severity, personal and social variables after armed robbery

OBJECTIVES

To investigate the relative importance of personal and social variables on post-trauma symptom recovery.

DESIGN

Prospective survey of armed robbery victims.

METHODS

Fifty-one consecutive armed robbery victims were assessed immediately and at 1 month post-raid for post-traumatic stress. One month post-raid, crisis support, causal attribution and coping were also measured. Thirty-one of the sample were assessed for symptoms 6 months after the raid.

RESULTS

Both the main and follow-up samples had high levels of post-traumatic stress symptoms immediately after the raid which reduced significantly 1 month later and, for the follow-up subsample, further still 6 months later. Higher levels of symptoms at 1 month and poor crisis support were associated with higher levels of symptoms at follow-up.

CONCLUSIONS

Purposeful coping, symptom severity and social support effect post-trauma recovery.

Cellular immune profile of patients with advanced cancer before and after taxane treatment

The purpose of this study is to determine immune recovery and function after treatment with docetaxel or paclitaxel. Peripheral blood mononuclear cells were harvested before chemotherapy and at weekly times afterwards for cycle 1. Leukocyte subsets ICD45hiCD14lo polymorphonuclear neutrophils, CD45hiCD14hi monocytes, CD45hiCD14- lymphocytes, CD3+CD4/CD8+ T cells, CD3-CD19+ B cells, CD3-CD16/CD56+ natural killer (NK) cells], and circulating cytokine levels [tumor necrosis factor-alpha, gamma-interferon (gamma-IFN), and interleukins (IL-2, IL-10, IL-12)] were followed. In addition, T-cell mitogenic function, NK function, and lymphokine activated killer (LAK) function was assessed. Ten patients were entered in the trial. T-cell frequency, B-cell frequency, and CD4/CD8 ratio did not change. IL-10 serum levels significantly decreased in paclitaxel-treated patients (4.4+/-1.3 pg/ml at week 4 versus 7.8+/-2.1 pg/ml at baseline; p < 0.05). IL-2, IL-12, and gamma-IFN levels were not detectable. NK cytotoxic activity decreased in docetaxel-treated patients. LAK cell activity was not altered. Four patients achieved a partial or complete response. They demonstrated higher than normal CD4:CD8 T-cell ratios and an improved phytohemagglutinin stimulation index (SI = 2.5). In conclusion, our findings suggest that immune function was affected more significantly after docetaxel treatment. Investigational approaches, which enhance cellular immunity, may be of greater relevance after treatment with docetaxel. Additional studies monitoring NK function after chemotherapy are recommended.

A polymorphism in the cystatin C gene is a novel risk factor for late-onset Alzheimer's disease

OBJECTIVE

To investigate whether or not a coding polymorphism in the cystatin C gene (CST3) contributes risk for AD.

DESIGN

A case-control genetic association study of a Caucasian dataset of 309 clinic- and community-based cases and 134 community-based controls.

RESULTS

The authors find a signficant interaction between the GG genotype of CST3 and age/age of onset on risk for AD, such that in the over-80 age group the GG genotype contributes two-fold increased risk for the disease. The authors also see a trend toward interaction between APOE epsilon4-carrying genotype and age/age of onset in this dataset, but in the case of APOE the risk decreases with age. Analysis of only the community-based cases versus controls reveals a significant three-way interaction between APOE, CST3 and age/age of onset.

CONCLUSION

The reduced or absent risk for AD conferred by APOE in older populations has been well reported in the literature, prompting the suggestion that additional genetic risk factors confer risk for later-onset AD. In the author's dataset the opposite effects of APOE and CST3 genotype on risk for AD with increasing age suggest that CST3 is one of the risk factors for later-onset AD. Although the functional significance of this coding polymorphism has not yet been reported, several hypotheses can be proposed as to how variation in an amyloidogenic cysteine protease inhibitor may have pathologic consequences for AD.

The effect of decreasing digital image resolution on teledermatology diagnosis

OBJECTIVE

To determine the effect of degraded digital image resolution (as viewed on a monitor) on the accuracy and confidence of dermatologic interpretation.

MATERIALS AND METHODS

Eight dermatologists interpreted 180 clinical cases divided into three Logical Competitor Sets (LCS) (pigmented lesions, non-pigmented lesions, and inflammatory dermatoses). Each case was digitized at three different resolutions. The images were randomized and divided into (9) 60-image sessions. The physicians were completely blinded concerning the image resolution. After 60 seconds per image, the viewer recorded a diagnosis and level of confidence. The resultant ROC curves compared the effect of LCS, level of clinical difficulty, and resolution of the digital image. One-way analysis of variance (ANOVA) compared the curves.

RESULTS

The areas beneath the ROC curves did not demonstrate any consistently significant difference between the digital image resolutions for all LCS and levels of difficulty. The only significant effect observed was amongst pigmented lesions (LCS-A) where the ROC curve area was significantly smaller in the easy images at high resolution compared to low and medium resolutions. For all other ROC curve comparisons within LCS-A, at all other levels of difficulty, as well as within the other LCS at all levels of difficulty, none of the differences was significant.

CONCLUSION

A 720 x 500 pixel image can be considered equivalent to a 1490 x 1000 pixel image for most store-and-forward teledermatology consultations.

The genetic association between Cathepsin D and Alzheimer's disease

The aspartyl protease Cathepsin D has previously been suggested to play a role in the Alzheimer's disease (AD) process because of its ability to cleave the beta-amyloid precursor protein and the possibility that it may be one of the 'secretase' enzymes. A functional C-->T polymorphism in the Cathepsin D gene (CATD) has been reported to be associated with increased risk for AD in Caucasian case-control studies; specifically, the T-carrying genotypes confer increased risk. We have examined this association in our own Caucasian dataset of 210 AD cases and 120 controls, and in an additional Hispanic dataset comprising 79 AD cases and 112 controls. In Hispanics we find a modest interaction between CATD genotype and age of onset on risk for AD, such that the non-T-carrying genotype confers increased risk. In our Caucasian dataset we find no evidence for association between the CATD polymorphism and AD, although we do observe a small tendency towards an increase in the T-carrying genotypes in the case group, consistent with previous studies. We conducted an aggregate analysis of the published Caucasian datasets and found evidence that this CATD polymorphism (or another locus in linkage disequilibrium) does contribute significant, but small (<2%) risk for AD.

DNase I footprinting of the human interleukin-5 gene promoter

A characteristic feature of allergic asthma is the overexpression of the T helper type 2 (Th2) cytokines interleukin-4 (IL-4), IL-5 and IL-13 by T lymphocytes. Of these cytokines, IL-5 is critical for the growth, survival and recruitment of eosinophils which are thought to be responsible for the tissue damage observed in asthmatic airways. The expression of human IL-5 is primarily regulated at the transcriptional level; however, little is known about the mechanisms that control its transcription. Using nuclear extracts from allergen-specific human T-cell clones we have performed DNase I footprinting of the human IL-5 promoter in order to establish sites occupied by transcription factors. We show footprints covering the conserved lymphokine element 0 ¿(CLE0) -60 to -44 base pairs (bp) and GATA (-73 to -62 bp) elements, which have previously been identified to be important in the regulation of the murine IL-5 promoter. We also describe a footprint covering a considerably extended Octamer binding site (-249 to -217 bp), which encompasses two hitherto unidentified CCAAT/enhancer binding protein consensus binding sites. We have also identified a previously unknown Ets binding site (-274 to -264 bp). These novel data on the regions of the human IL-5 promoter that are bound by transcription factors should allow dissection of the regulatory mechanisms involved in the transcription of IL-5 in the T-helper lymphocytes of asthmatics.

Phase I evaluation of ISIS 3521, an antisense oligodeoxynucleotide to protein kinase C-alpha, in patients with advanced cancer

PURPOSE

To determine the maximum-tolerated dose (MTD) and pharmacologic behavior of ISIS 3521 (ISI 641A), an antisense phosphorothioate oligonucleotide to protein kinase C-alpha.

PATIENTS AND METHODS

Thirty-six patients with advanced cancer received 99 cycles of ISIS 3521 (0.15 to 6.0 mg/kg/d) as a 2-hour intravenous infusion administered three times per week for 3 consecutive weeks and repeated every 4 weeks. Plasma and urine sampling was performed during the first week of treatment and subjected to capillary gel electrophoresis to determine full-length antisense oligonucleotide in addition to chain-shortened metabolites.

RESULTS

Drug-related toxicities included mild to moderate nausea, vomiting, fever, chills, and fatigue. Hematologic toxicity was limited to thrombocytopenia (grade 1, four patients; grade 2, one patient; grade 3, one patient). There was no relationship between dose, maximum concentration of the drug (C(max)), or area under the plasma concentration versus time curve (AUC) and coagulation times or complement levels. Dose escalation was discontinued because of the attainment of peak plasma concentrations, which approached that associated with complement activation in primates. Two patients with non-Hodgkin's lymphoma who completed 17 and nine cycles of therapy achieved complete responses. The pharmacokinetic profile of ISIS 3521 revealed a short elimination half-life (18 to 92 minutes), as well as a dose-dependent decrease in clearance and dose-dependent increases in C(max), AUC, and elimination half-life.

CONCLUSION

No dose-limiting toxicity of ISIS 3521 was identified, and clinical activity was observed. A short elimination half-life was identified, which suggests that alternate schedules with prolonged administration may be necessary for further clinical development.

Community networking as a means for identifying people with diabetes in a rural, predominantly bicultural community in New Zealand

AIMS

To assess the use of community networking to estimate the prevalence of diabetes in a predominantly New Zealand Maori and European community.

METHODS

A cross-sectional survey of people with known diabetes identified either through general practice or community networks (others with diabetes, public notices or public meetings) was undertaken. Ascertainment was compared using capture-recapture methods for two independent samples.

RESULTS

Overall ascertainment by community networking was greater for Maori than Europeans (40 +/- 3% vs 15 +/- 2%, p < 0.001). Ascertainment using general practice registers was comparable in the two ethnic groups (48 +/- 4% vs 55 +/- 5%, respectively). Women were more likely than men to be contacted through community networking (odds ratio 1.47, 1.05-2.06).

CONCLUSION

In closely knit communities, community networking provides an independent source for estimating the prevalence of diabetes.

Injuries in the adolescent population in Scotland: patterns and types of injuries sustained

OBJECTIVE

To provide information on the incidence, sex distribution, type, site and severity of injuries requiring medical attention reported in a nationally representative sample of Scottish teenagers studied longitudinally.

DESIGN

Health visitors administered structured interviews with parents (usually mothers). Quantitative data were analysed using SPSS-PC, and qualitative and textual data were coded using the Abbreviated Injury Score (AIS).

SETTING

Scotland.

SUBJECTS

Responses were received in respect of 958 (68%) of the estimated 1,416 teenagers enrolled in the British Cohort Study (BCS 70), and resident in Scotland in 1986/7.

RESULTS

43% of subjects were reported as having experienced one or more unintentional injury events requiring medical attention between the ages of 10 and 16/17. Boys experienced significantly more injuries than girls. Neither social class nor region appeared to be a significant risk factor for reported injury.

CONCLUSION

Patterns of accidents in Scottish adolescents are reported. Further areas for study are suggested.