Low frequency of CHEK2 1100delC allele in Australian multiple-case breast cancer families: functional analysis in heterozygous individuals

A protein-truncating variant of CHEK2, 1100delC, is associated with a moderate increase in breast cancer risk. We have determined the prevalence of this allele in index cases from 300 Australian multiple-case breast cancer families, 95% of which had been found to be negative for mutations in BRCA1 and BRCA2. Only two (0.6%) index cases heterozygous for the CHEK2 mutation were identified. All available relatives in these two families were genotyped, but there was no evidence of co-segregation between the CHEK2 variant and breast cancer. Lymphoblastoid cell lines established from a heterozygous carrier contained approximately 20% of the CHEK2 1100delC mRNA relative to wild-type CHEK2 transcript. However, no truncated CHK2 protein was detectable. Analyses of expression and phosphorylation of wild-type CHK2 suggest that the variant is likely to act by haploinsufficiency. Analysis of CDC25A degradation, a downstream target of CHK2, suggests that some compensation occurs to allow normal degradation of CDC25A. Such compensation of the 1100delC defect in CHEK2 might explain the rather low breast cancer risk associated with the CHEK2 variant, compared to that associated with truncating mutations in BRCA1 or BRCA2.

Clinical predictors of acute coronary syndromes in patients with undifferentiated chest pain

BACKGROUND

Patients with acute, undifferentiated chest pain present a frequent diagnostic challenge to clinicians. Clinical features are often used to determine which patients may have acute coronary syndrome (ACS).

AIM

To identify clinical features that independently predict ACS in patients with acute, undifferentiated chest pain.

DESIGN

Prospective study of patients enrolled in a randomized controlled trial.

METHODS

The presenting characteristics of participants in the ESCAPE randomized trial of chest pain unit vs. routine care were recorded in a standardized manner. Follow-up consisted of troponin T measurement at 2 days, postal questionnaire at 1 month, and telephone contact at 6 months. ACS was defined as elevated troponin T at 2 days or major adverse cardiac event within 30 days of presentation. Multivariate analysis identified independent clinical predictors of ACS.

RESULTS

ACS was diagnosed in 77 (7.9%) of the 972 patients recruited. The following characteristics were independent predictors of ACS (odds ratio, p): age (1.09, p < 0.001), male gender (8.6, p < 0.001), indigestion or burning-type pain (3.0, p = 0.034), pain radiating to the left (2.4, p = 0.013) or right (5.7, p < 0.001) arm, vomiting (3.5, p = 0.007), and previous (5.1, p < 0.001) or current (3.7, p < 0.001) smoking.

DISCUSSION

In addition to previously recognized predictors of ACS, it appears that indigestion or burning type pain predicts ACS in patients attending the emergency department with acute, undifferentiated chest pain. Diagnosis of acute 'gastro-oesophageal' chest pain should be avoided in this setting.

[Experiences after 150 cartilage-bone-transplantations of the knee: a prospective analysis of the results]

INTRODUCTION

To evaluate the clinical outcome of cartilage-bone-transplantations of the knee in patients with different indications, we studied the clinical results of 45 patients with a follow-up of 24 months after operation.

PATIENTS AND METHODS

29 male and 16 female patients with a mean age of 37.7 yrs (16-58 yrs) were included. Indications for operation were osteochondritis dissecans (OD) (n=13), limited arthritis (n=20), traumatic lesions (n=5) and retropatellar lesions (n=7). The results were evaluated by clinical score (McDermott Score; preoperatively, and 3, 6, 12, 24 months postoperatively), magnetic resonance imaging, and re-arthroscopy for most patients.

RESULTS

42 of 45 patients judged the operation as successful. The mean score value of all patients raised from 66.3 pts (out of 100 pts) preoperatively to 92.7 pts 24 months postoperatively. The results of the patients with circumscript arthritic lesions (62.9 pts. preoperatively vs. 91.5 pts. postoperatively) were comparable to those of the other patients.

CONCLUSION

We conclude that cartilage-bone-transplantation of the knee is a valuable procedure to improve joint function not only after OD or trauma, but also in joints with local arthritic lesions on condition that there is an adequate quality of the donor site.

Analysis of the candidate 8p21 tumour suppressor, BNIP3L, in breast and ovarian cancer

Loss of heterozygosity (LOH) on the short arm of chromosome 8, at 8p12-p23, is one of the most frequent genetic events in both breast and ovarian cancer, suggesting the location of a shared tumour suppressor gene. Microcell-mediated chromosome transfer of chromosome 8 suppresses tumorigenicity and growth of colorectal and prostate cancer cell lines, further supporting the presence of a tumour suppressor gene on 8p. We have taken a candidate gene approach to try to identify this tumour suppressor gene at 8p12-p23. BNIP3L, which has sequence homology to pro-apoptotic proteins and the ability to suppress colony formation in soft agar, is located at 8p21, within a region of ovarian cancer LOH, breast cancer LOH and prostate cancer metastasis suppression. BNIP3L expression was assessed by both RT-PCR and Northern blot analysis in breast and ovarian cancer cell lines and found to be expressed at similar levels relative to expression in their respective normal epithelial cell lines. Genetic analysis of BNIP3L in 40 primary ovarian and 25 primary breast tumours identified one somatic, intronic mutation in one ovarian tumour, as well as several polymorphisms, including one resulting in an amino-acid substitution. These data suggest that BNIP3L is unlikely to be the target of 8p LOH in ovarian or breast cancer.

An ensemble method for identifying regulatory circuits with special reference to the qa gene cluster of Neurospora crassa

A chemical reaction network for the regulation of the quinic acid (qa) gene cluster of Neurospora crassa is proposed. An efficient Monte Carlo method for walking through the parameter space of possible chemical reaction networks is developed to identify an ensemble of deterministic kinetics models with rate constants consistent with RNA and protein profiling data. This method was successful in identifying a model ensemble fitting available RNA profiling data on the qa gene cluster.

A prospective, observational study of a chest pain observation unit in a British hospital

OBJECTIVES

To establish a chest pain observation unit, monitor its performance in terms of appropriate discharge after assessment, and estimate the cost per patient.

METHODS

Prospective, observational, cohort study of patients attending a large, city, teaching hospital accident and emergency department between 1 March 1999 and 29 February 2000 with acute undifferentiated chest pain. Patients were managed on a chest pain observation unit, entailing two to six hours of observation, serial electrocardiograph recording, cardiac enzyme measurement, and, where appropriate, exercise stress test. Patients were discharged home if all tests were negative and admitted to hospital if tests were positive or equivocal. The following outcomes were measured-proportion of participants discharged after assessment; clinical status three days after discharge; cardiac events and procedures during the following six months; and cost of assessment and admission.

RESULTS

Twenty three participants (4.3%) had a final diagnosis of myocardial infarction. All were detected and admitted to hospital. A total of 461 patients (86.3%) were discharged after assessment, 357 (66.9%) avoided hospital admission entirely. At review three days later these patients had no new ECG changes and only one raised troponin T measurement. In the six months after assessment, three cardiac deaths, two myocardial infarctions, and two revascularisation procedures were recorded among those discharged. The mean cost of assessment and hospital admission was 221 pound per patient, or 323 pound if subsequent interventional cardiology costs were included.

CONCLUSIONS

The chest pain observation unit is a practical alternative to routine care for acute chest pain in the United Kingdom. Negative assessment effectively rules out immediate, serious morbidity, but not longer term morbidity and mortality. Costs seem to be similar to routine care.

Simulation code for the interaction of 14 MeV neutrons on cells

The structure of the survival curve of melanoma cells irradiated by 14 MeV neutrons displays unusual features at very low dose rate where a marked increase in cell killings at 0.05 Gy is followed by a plateau for survival from 0.1 to 0.32 Gy. In parallel a simulation code was constructed for the interaction of 14 MeV neutrons with cellular cultures. The code describes the interaction of the neutrons with the atomic nuclei of the cellular medium and of the external medium (flask culture and culture medium), and is used to compute the deposited energy into the cell volume. It was found that the large energy transfer events associated with heavy charged recoils can occur and that a large part of the energy deposition events are due to recoil protons emitted from the external medium. It is suggested that such events could partially explain the experimental results.

Reactivity of a titanium dinitrogen complex supported by guanidinate ligands: investigation of solution behavior and a novel rearrangement of guanidinate ligands

The titanium dinitrogen complex, [[(Me(2)N)C(N(i)Pr)(2)]( 2)Ti](2)(N(2)) (2), was synthesized by reduction of the dichloride precursor, [(Me(2)N)C(N(i)Pr)(2)](2)TiCl(2) (1). The dinitrogen complex reacts with phenyl azide to yield the titanium imido complex, [(Me(2)N)C(N(i)Pr)(2)](2)TiNPh (3). The fluxional behavior of the guanidinate ligands in compounds 1-3 was investigated using variable temperature and two-dimensional NMR techniques; guanidinate ligand rotation and racemization reactions were observed. Rearrangement of the guanidinate ligand to an asymmetrical bonding mode utilizing the dimethylamino and amide-nitrogen atoms is observed in the bridging oxo and sulfido derivatives (4 and 5). These compounds are formed by the reactions of 2 with pyridine N-oxide and propylene sulfide, respectively. The ligand rearrangement was observed to be reversible for the bridging sulfido complex 5; the structure of this compound is sensitive to temperature and solvent. The solid-state and solution structures of compounds 1-5 are discussed.

Reactivity of a titanium dinitrogen complex supported by guanidinate ligands: investigation of solution behavior and a novel rearrangement of guanidinate ligands

The titanium dinitrogen complex, [[(Me(2)N)C(N(i)Pr)(2)]( 2)Ti](2)(N(2)) (2), was synthesized by reduction of the dichloride precursor, [(Me(2)N)C(N(i)Pr)(2)](2)TiCl(2) (1). The dinitrogen complex reacts with phenyl azide to yield the titanium imido complex, [(Me(2)N)C(N(i)Pr)(2)](2)TiNPh (3). The fluxional behavior of the guanidinate ligands in compounds 1-3 was investigated using variable temperature and two-dimensional NMR techniques; guanidinate ligand rotation and racemization reactions were observed. Rearrangement of the guanidinate ligand to an asymmetrical bonding mode utilizing the dimethylamino and amide-nitrogen atoms is observed in the bridging oxo and sulfido derivatives (4 and 5). These compounds are formed by the reactions of 2 with pyridine N-oxide and propylene sulfide, respectively. The ligand rearrangement was observed to be reversible for the bridging sulfido complex 5; the structure of this compound is sensitive to temperature and solvent. The solid-state and solution structures of compounds 1-5 are discussed.

Enhanced bioavailability of calcitonin formulated with alkylglycosides following nasal and ocular administration in rats

PURPOSE

The purpose of this study was to characterize the effects of alkylglycosides on the bioavailability of calcitonin following nasal and ocular administration.

METHODS

A salmon calcitonin specific radioimmunoassay kit was used to measure calcitonin levels in anesthetized rats at various times after nasal or ocular administration of calcitonin formulated with saline or with octylmaltoside, a medium chain length alkylglycoside or tetradecylmaltoside, a long chain alkylglycoside. The extent of calcitonin absorption was determined directly from the plasma calcitonin level-time curve and the bioavailability of calcitonin was determined from the area under the plasma calcium level-time curve. The calcium level was determined using a colorimetric method.

RESULTS

When the nasal formulation contained calcitonin plus saline or 0.125% octylmaltoside, little or no calcitonin was absorbed. However, plasma calcitonin levels were increased and plasma calcium levels were decreased when the nasal formulation contained calcitonin plus 0.125% or 0.25% tetradecylmaltoside. Maximal calcitonin levels were observed 7.5-10 min after nasal administration of the formulation. Ocular administration of calcitonin formulated with tetradecylmaltoside also resulted in calcitonin absorption, but less calcitonin absorption was found after ocular administration than after nasal administration.

CONCLUSION

The experimental data indicate that tetradecylmaltoside, but not octylmaltoside. can be effectively used to enhance the bioavailability of nasally and ocularly administered calcitonin.

Toxic shock syndrome originating from the foot

The most familiar etiology of toxic shock syndrome (TSS) is that of menstruation and tampon use. Nonmenstrual TSS has been described in all types of wounds including postsurgical, respiratory infection, mucous membrane disruption, burns, and vesicular lesions caused by varicella and shingles. A case of TSS occurring in a diabetic male patient with foot blisters is presented. Early recognition by an infectious disease specialist and appropriate medical management led to complete recovery. There have been no reported cases of Staphylococcus aureus TSS originating in the foot to date.

Psychologic morbidity and health-related quality of life of patients assessed in a chest pain observation unit

STUDY OBJECTIVES

We sought to measure psychologic morbidity and health-related quality of life among patients attending the hospital with acute chest pain both at presentation and 1 month after rigorous assessment for cardiac disease.

METHODS

Consecutive patients undergoing assessment on the chest pain observation unit of a large, urban emergency department were asked to complete 3 questionnaires: the Short Form-36 Health Survey (SF-36), the Euroqol Health Utility Questionnaire, and the Hospital Anxiety and Depression Scale. The same questionnaires were mailed 1 month later, along with a questionnaire documenting subsequent pain and reassurance.

RESULTS

At enrollment (n=166), 32 (19%) participants (95% confidence interval [CI] 15% to 26%) were experiencing moderate levels of anxiety, and 21 (13%, 95% CI 8% to 19%) were experiencing moderate levels of depression. Health utility and all SF-36 dimensions of quality of life were substantially below age-adjusted normal values. One month after assessment (n=110), only the Pain dimension score of SF-36 had significantly improved. Most scores were unchanged, and the Physical Role and Mental Health dimension scores of SF-36 had significantly deteriorated. Seventy (64%) patients (95% CI 54% to 72%) had further pain after discharge. Despite these findings, 98 (86%) patients (95% CI 78% to 91%) responded that their assessment was "completely reassuring" or "quite reassuring."

CONCLUSION

Patients with acute, undifferentiated chest pain have substantial psychologic morbidity and impairment of quality of life. Although patients respond that they are reassured by chest pain observation unit assessment, anxiety and depression remain prevalent and quality of life remains impaired 1 month after assessment.

An analysis of gene-finding programs for Neurospora crassa

MOTIVATION

Computational gene identification plays an important role in genome projects. The approaches used in gene identification programs are often tuned to one particular organism, and accuracy for one organism or class of organism does not necessarily translate to accurate predictions for other organisms. In this paper we evaluate five computer programs on their ability to locate coding regions and to predict gene structure in Neurospora crassa. One of these programs (FFG) was designed specifically for gene-finding in N.crassa, but the model parameters have not yet been fully 'tuned', and the program should thus be viewed as an initial prototype. The other four programs were neither designed nor tuned for N.crassa.

RESULTS

We describe the data sets on which the experiments were performed, the approaches employed by the five algorithms: GenScan, HMMGene, GeneMark, Pombe and FFG, the methodology of our evaluation, and the results of the experiments. Our results show that, while none of the programs consistently performs well, overall the GenScan program has the best performance on sensitivity and Missing Exons (ME) while the HMMGene and FFG programs have good performance in locating the exons roughly. Additional work motivated by this study includes the creation of a tool for the automated evaluation of gene-finding programs, the collection of larger and more reliable data sets for N.crassa, parameterization of the model used in FFG to produce a more accurate gene-finding program for this species, and a more in-depth evaluation of the reasons that existing programs generally fail for N.crassa.

AVAILABILITY

Data sets, the FFG program source code, and links to the other programs analyzed are available at http://jerry.cs.uga.edu/~wang/genefind.html.

CONTACT

eileen@cs.uga.edu.

Genome of the bacterium Streptococcus pneumoniae strain R6

Streptococcus pneumoniae is among the most significant causes of bacterial disease in humans. Here we report the 2,038,615-bp genomic sequence of the gram-positive bacterium S. pneumoniae R6. Because the R6 strain is avirulent and, more importantly, because it is readily transformed with DNA from homologous species and many heterologous species, it is the principal platform for investigation of the biology of this important pathogen. It is also used as a primary vehicle for genomics-based development of antibiotics for gram-positive bacteria. In our analysis of the genome, we identified a large number of new uncharacterized genes predicted to encode proteins that either reside on the surface of the cell or are secreted. Among those proteins there may be new targets for vaccine and antibiotic development.

Faculty Development: an approach to scholarship

This consultation to promote scholarship resulted in the development of two projects, a study of the relationship between power and teaching-learning and the integration of holistic concepts into the curriculum. These projects were developed because the consultant was able to promote faculty discussion of organizational issues that had been felt but not verbalized. The discussion of these concerns permitted insight into group dynamics and clarified the concerns that had hampered effective group functioning and the pursuit of scholarship. The faculty became empowered to more effectively communicate with the administration faculty values and the importance of creating an environment to enhance scholarly activities. The consultant on scholarship was the catalyst who promoted the change in attitudes and activities.