Extreme chromosomal instability forecasts improved outcome in ER-negative breast cancer: a prospective validation cohort study from the TACT trial

BACKGROUND

Chromosomal instability (CIN) has been shown to be associated with drug resistance and poor clinical outcome in several cancer types. However, in oestrogen receptor (ER)-negative breast cancer we have previously demonstrated that extreme CIN is associated with improved clinical outcome, consistent with a negative impact of CIN on tumour fitness and growth. The aim of this current study was to validate this finding using previously defined CIN thresholds in a much larger prospective cohort from a randomised, controlled, clinical trial.

PATIENTS AND METHODS

As a surrogate measurement of CIN, dual centromeric fluorescence in situ hybridisation was performed for both chromosomes 2 and 15 on 1173 tumours from the breast cancer TACT trial (CRUK01/001). Each tumour was scored manually and the mean percentage of cells deviating from the modal centromere number was used to define four CIN groups (MCD1-4), where tumours in the MCD4 group were defined as having extreme CIN.

RESULTS

In a multivariate analysis of disease-free survival, with a median follow-up of 91 months, increasing CIN was associated with improved outcome in patients with ER-negative cancer (P trend = 0.03). A similar pattern was seen in ER-negative/HER2-negative cancers (Ptrend = 0.007).

CONCLUSIONS

This prospective validation cohort study further substantiated the association between extreme CIN and improved outcome in ER-negative breast cancers. Identifying such patients with extreme CIN may help distinguish good from poor prognostic groups, and therefore support treatment and risk stratification in this aggressive breast cancer subtype.

Germline CDH1 mutations in bilateral lobular carcinoma in situ

BACKGROUND

Invasive lobular breast cancer (ILC) and lobular carcinoma in situ (LCIS) are characterised by loss of E-cadherin expression. However germline CDH1 mutations are rare in cases of ILC with no family history of hereditary diffuse gastric cancer (HDGC) and have not been described in women with LCIS.

METHODS

We screened the CDH1 gene in 50 cases of bilateral LCIS/ILC using Sanger sequencing and MLPA.

RESULTS

Sanger sequencing revealed four pathogenic germline mutations, including a novel splicing mutation (c.48+1G>A). The remaining three (c.1465insC, c.1942G>T, c.2398delC) have been previously described. All four cases had bilateral LCIS +/- ILC and no family history of gastric cancer.

CONCLUSION

CDH1 germline mutations have not been previously described in women with LCIS. We have shown that germline CDH1 mutations are associated with early onset of bilateral LCIS with or without ILC in women without a family history of gastric cancer. CDH1 mutation screening should be considered in women with early onset of bilateral LCIS/ILC with no family history of HDGC.

High-peak-power, high-energy, high-average-power pulsed fiber laser system with versatile pulse duration and shape

We present a pulsed fiber laser system with average power up to 265 W, pulse energy up to 10.6 mJ, pulse duration adjustable in the range 500 ps-500 ns, repetition rate fully controllable from single-shot operation up to 1 MHz, and the ability to control peak power independently of pulse energy. The system has a compact, all-spliced construction. Such a versatile laser will have wide applications in materials processing.

A Functional Role for CERT in Cancer Drug Induced Autophagy and Prognosis in Her2 Positive Breast Cancer

CERT was recently identified in a functional genomic siRNA screen for regulators of multi-drug sensitivity. CERT encodes a ceramide transporter which shuttles the pro-apoptotic lipid ceramide from the endoplasmic reticulum to the golgi. Silencing CERT, promoted sensitivity to paclitaxel, doxorubicin, cisplatin and 5-FU in breast, colon and non-small cell lung cancer cell lines. Further analysis of CERT expression in 18 NCI-60 cancer cell lines together with drug sensitivity data for over 5000 drugs within the NCI database, revealed that elevated CERT expression is associated with multi-drug resistance to diverse cancer cytotoxics. CERT mRNA was significantly elevated in HER2 positive breast cancer cell lines. Consistent with these data, in a primary breast cancer tissue microarray cohort of 356 primary breast cancers with outcome data, CERT protein expression was significantly greater in Her2 positive disease (p<0.0001). Survival analysis indicates that increased CERT expression correlates with significantly poorer long-term survival across the whole cohort and in Her2 positive patients.In order to explore the downstream molecular targets of CERT activity, we used the Affymetrix GeneChip Exon Array to detect gene expression changes following siRNA mediated CERT silencing. Genes that were differentially expressed following CERT silencing were identified and validated by real-time PCR. Significant representation of genes involved in the autophagy pathway were identified. One of these genes, LAMP2, a protein involved in autophagosome-lysosome fusion, is up-regulated following CERT silencing. LAMP2 silencing promotes paclitaxel resistance when depleted from cancer cells. Consistent with a role for CERT silencing in mediating an autophagy response following drug exposure, CERT depletion together with Paclitaxel treatment induces alterations in the autophagy response marker-LC3 similar to those seen in starvation-induced autophagy and an increase in lysosomal activity as visualised by microscopy. These data indicate a role for autophagy in regulating cytotoxic drug response in cancer.The pharmacological targeting of CERT, a poor prognostic marker in breast cancer, may be a rational approach to enhance drug response and patient outcome.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1137.

A comprehensive study of chromosome 16q in invasive ductal and lobular breast carcinoma using array CGH

We analysed chromosome 16q in 106 breast cancers using tiling-path array-comparative genomic hybridization (aCGH). About 80% of ductal cancers (IDCs) and all lobular cancers (ILCs) lost at least part of 16q. Grade I (GI) IDCs and ILCs often lost the whole chromosome arm. Grade II (GII) and grade III (GIII) IDCs showed less frequent whole-arm loss, but often had complex changes, typically small regions of gain together with larger regions of loss. The boundaries of gains/losses tended to cluster, common sites being 54.5-55.5 Mb and 57.4-58.8 Mb. Overall, the peak frequency of loss (83% cancers) occurred at 61.9-62.9 Mb. We also found several 'minimal' regions of loss/gain. However, no mutations in candidate genes (TRADD, CDH5, CDH8 and CDH11) were detected. Cluster analysis based on copy number changes identified a large group of cancers that had lost most of 16q, and two smaller groups (one with few changes, one with a tendency to show copy number gain). Although all morphological types occurred in each cluster group, IDCs (especially GII/GIII) were relatively overrepresented in the smaller groups. Cluster groups were not independently associated with survival. Use of tiling-path aCGH prompted re-evaluation of the hypothetical pathways of breast carcinogenesis. ILCs have the simplest changes on 16q and probably diverge from the IDC lineage close to the stage of 16q loss. Higher-grade IDCs probably develop from low-grade lesions in most cases, but there remains evidence that some GII/GIII IDCs arise without a GI precursor.

Germline deletions of EXO1 do not cause colorectal tumors and lesions which are null for EXO1 do not have microsatellite instability

Exonuclease 1 (EXO1) is a candidate gene for colorectal tumor susceptibility because it is believed to play a role in mismatch repair. There have been several studies investigating the role of EXO1 in mismatch repair but few investigating its role in causing clinical disease. In one recent study, germline variants of EXO1 were reported to be associated with predisposition to colorectal cancer in families with phenotypes similar to hereditary nonpolyposis colon cancer (HNPCC). We recently identified nine individuals from two British families with multiple cutaneous and uterine leiomyomatosis with independently arising heterozygous germline deletions of 1q42.3 approximately q43 encompassing not only FH, the multiple leiomyomatosis-associated gene, but also several flanking genes, including EXO1. We investigated these families for any indication of predisposition to colorectal cancer or other HNPCC spectrum cancers by means of detailed questionnaires, interviews, and examination of EXO1-null skin leiomyomata for microsatellite instability (MSI). No individual in these families had developed colorectal cancer or known colorectal adenomas, and none had any symptoms warranting gastrointestinal or other investigation. EXO1-null tumors showed no evidence of MSI. This study questions the functional significance of previously reported variants of EXO1 reported in HNPCC-like families and suggests that in humans there may be other as yet undiscovered proteins that have exonuclease function overlapping with that of EXO1 in DNA mismatch repair. Also of interest is the absence of phenotypic abnormality apart from multiple leiomyomatosis in any deletion carrier even though the adjacent genes RGS7, KMO, CHML, and OPN3 were also deleted.

Analysis of chromosomal instability in human colorectal adenomas with two mutational hits at APC

In vitro data show that the adenomatous polyposis coli (APC) protein associates with the mitotic spindle and that mouse embryonic stem cells with biallelic Apc mutations are karyotypically unstable. These findings led to suggestions that APC acts in chromosomal segregation and that APC inactivation leads to chromosomal instability (CIN). An alternative hypothesis based on allelic loss studies in colorectal adenomas proposes that CIN precedes and contributes to genetic changes at APC. We determined whether colorectal adenomas with two mutations at APC show features consistent with these models by studying 55 lesions (average size 5 mm; range 1-13 mm) from patients with familial adenomatous polyposis. A variety of methods was used depending on available material, including flow cytometry, comparative genomic hybridization, and loss of heterozygosity (LOH) analysis. Selected adenomas were assessed for proliferative activity by Ki-67 immunocytochemistry. Seventeen of 20 (85%) tumors were diploid, two were near-diploid, and one was hypotetraploid. Just one (near-diploid) tumor showed increased proliferative activity. LOH was found occasionally on chromosome 15q (2 of 49 tumors), but not on chromosome 18q (0 of 48). In 20 adenomas, LOH at APC was associated with loss at 5q but not 5p markers, with the former encompassing a minimum of 20 Mb. However, three of these lesions analyzed by comparative genomic hybridization displayed normal profiles, suggesting, together with other data, that the mechanism of LOH at APC is probably somatic recombination. Our results therefore do not support the hypothesis that CIN precedes APC mutations in tumorigenesis. Regarding the model in which APC mutations lead directly to CIN, if APC mutations do have this effect in vivo, it must be subtle. Alternatively, CIN associated with APC mutations might be essentially an in vitro phenomenon.

Molecular characteristics of serrated adenomas of the colorectum

BACKGROUND

Serrated adenomas (SAs) of the colorectum combine architectural features of hyperplastic polyps and cytological features of classical adenomas. Molecular studies comparing SAs and classical adenomas suggest that each may be a distinct entity; in particular, it has been proposed that microsatellite instability (MSI) distinguishes SAs from classical adenomas and that SAs and the colorectal cancers arising from them develop along a pathway driven by low level microsatellite instability (MSI-L).

AIMS

To define the molecular characteristics of SAs of the colorectum.

MATERIALS AND METHODS

We analysed 39 SAs from 27 patients, including eight SAs from patients with familial adenomatous polyposis (FAP). We screened these polyps for selected molecular changes, including loss of heterozygosity (LOH) close to APC (5q21) and CRAC1 (15q13-q22), MSI, and mutations of K-ras, APC, p53, and beta-catenin. Expression patterns of beta-catenin, p53, MLH1, MSH2, E-cadherin, and O(6)-methylguanine DNA methyltransferase (MGMT) were assessed by immunohistochemistry. Comparative genomic hybridisation was performed on several polyps.

RESULTS

MSI was rare (<5% cases) and there was no loss of expression of mismatch repair proteins. Wnt pathway abnormalities (APC mutation/LOH, beta-catenin mutation/nuclear expression) occurred in 11 SAs, including 6/31 (19%) non-FAP tumours. CRAC1 LOH occurred in 23% of tumours. K-ras mutations and p53 mutations/overexpression were found in 15% and 8% of SAs, respectively. Loss of MGMT expression occurred in 18% of polyps and showed a borderline association with K-ras mutations. Aberrant E-cadherin expression was found in seven polyps. Comparative genomic hybridisation detected no gains or deletions of chromosomal material.

CONCLUSIONS

The serrated pathway of colorectal tumorigenesis appears to be heterogeneous. In common with classical adenomas, some SAs develop along pathways involving changes in APC/beta-catenin. SAs rarely show MSI or any evidence of chromosomal-scale genetic instability. K-ras mutations may however be less common in SAs than in classical adenomas. Some SAs may harbour changes in the CRAC1 gene. Changes in known genes do not account for the growth of the majority of SAs.

Investigating physician order entry in the field: lessons learned in a multi-center study

The progress of studies by this team of researchers concerning computerized physician order entry (POE), beginning with a mail survey and moving to qualitative multi-center studies, is reviewed, with emphases on lessons learned and future directions. While mail surveys were appropriate to answer initial research questions about diffusion of POE in the U.S., multiple qualitative methods became the methods of choice for answering more complex questions. Results of the latter include articulation of multiple perspectives on both positive and negative aspects of POE and a description of what may be important for successful implementation of POE in the future. The present economic environment of hospitals may be inhibiting widespread diffusion of POE, not only because of the direct cost, but also indirectly by affecting relations with practitioners. Analysis of successful past implementations can provide guidance when the time is right.

Information needs in primary care: a survey of rural and nonrural primary care physicians

OBJECTIVE

To compare the self-reported information needs of rural and nonrural primary care physicians.

DESIGN AND PARTICIPANTS

Mail survey of active non-academic primary care physicians.

DATA COLLECTION

A 60 item questionnaire regarding 1) demographic and practice setting data; 2) medical information needs; 3) medical knowledge resource availability and use; and 4) physician information seeking behavior.

MAIN RESULTS

The response rate was higher among rural than non-rural physicians (55% vs. 42%, p< 0.001) and among Family Physicians than others (Family Medicine 53%, Internal Medicine 43%, Pediatrics 48%, p=0.015.) Rural physicians reported working more hours per week (45.3 vs. 42.7, p=0.033,) and seeing more patients per day (24.6 vs. 22.3, p=0.005) than their nonrural counterparts. Both groups reported a median of about 1 question for every 10 patients they see, with great variance among responses. Both groups reported pursuing answers to about 57% of their questions, and finding answers to about 70% of those they pursue. Knowledge resource preferences of the two groups were similar. Both groups reported frequent use of consultants, drug compendia, colleagues, and textbooks, and little use of library- or computer-based sources. Compared to nonrural physicians, rural physicians reported less frequent use of consultants, colleagues, librarians, and bound journals. These differences were small, and paralleled differences in availability. The two groups had equal access to textbooks and drug compendia, but for rural physicians, other resources were locally available significantly less often.

CONCLUSIONS

Rural and nonrural primary care physicians reported equal information needs, similar information seeking, and similar resource preferences. Rural physicians reported less access to some information resources, but little difference in use of resources. Further studies are needed to determine how these differences impact rural practitioners and their patients.

Policy implications for implementing evidence-based practices

The authors describe the policy and administrative-practice implications of implementing evidence-based services, particularly in public-sector settings. They review the observations of the contributors to the evidence-based practices series published throughout 2001 in Psychiatric Services. Quality and accountability have become the watchwords of health and mental health services; evidence-based practices are a means to both ends. If the objective of accountable, high-quality services is to be achieved by implementing evidence-based practices, the right incentives must be put in place, and systemic barriers must be overcome. The authors use the framework from the U.S. Surgeon General's 1999 report on mental health to describe eight courses of action for addressing the gap between science and practice: continue to build the science base; overcome stigma; improve public awareness of effective treatments; ensure the supply of mental health services and providers; ensure delivery of state-of-the-art treatments; tailor treatment to age, sex, race, and culture; facilitate entry into treatment; and reduce financial barriers to treatment.

Clinical decision support systems for the practice of evidence-based medicine

BACKGROUND

The use of clinical decision support systems to facilitate the practice of evidence-based medicine promises to substantially improve health care quality.

OBJECTIVE

To describe, on the basis of the proceedings of the Evidence and Decision Support track at the 2000 AMIA Spring Symposium, the research and policy challenges for capturing research and practice-based evidence in machine-interpretable repositories, and to present recommendations for accelerating the development and adoption of clinical decision support systems for evidence-based medicine.

RESULTS

The recommendations fall into five broad areas--capture literature-based and practice-based evidence in machine--interpretable knowledge bases; develop maintainable technical and methodological foundations for computer-based decision support; evaluate the clinical effects and costs of clinical decision support systems and the ways clinical decision support systems affect and are affected by professional and organizational practices; identify and disseminate best practices for work flow-sensitive implementations of clinical decision support systems; and establish public policies that provide incentives for implementing clinical decision support systems to improve health care quality.

CONCLUSIONS

Although the promise of clinical decision support system-facilitated evidence-based medicine is strong, substantial work remains to be done to realize the potential benefits.

Efficacy of an implanted neuroprosthesis for restoring hand grasp in tetraplegia: a multicenter study

OBJECTIVE

To evaluate an implanted neuroprosthesis that allows tetraplegic users to control grasp and release in 1 hand.

DESIGN

Multicenter cohort trial with at least 3 years of follow-up. Function for each participant was compared before and after implantation, and with and without the neuroprosthesis activated.

SETTING

Tertiary spinal cord injury (SCI) care centers, 8 in the United States, 1 in the United Kingdom, and 1 in Australia.

PARTICIPANTS

Fifty-one tetraplegic adults with C5 or C6 SCIs.

INTERVENTION

An implanted neuroprosthetic system, in which electric stimulation of the grasping muscles of 1 arm are controlled by using contralateral shoulder movements, and concurrent tendon transfer surgery. Assessed participants' ability to grasp, move, and release standardized objects; degree of assistance required to perform activities of daily living (ADLs), device usage; and user satisfaction.

MAIN OUTCOME MEASURES

Pinch force; grasp and release tests; ADL abilities test and ADL assessment test; and user satisfaction survey.

RESULTS

Pinch force was significantly greater with the neuroprosthesis in all available 50 participants, and grasp-release abilities were improved in 49. All tested participants (49/49) were more independent in performing ADLs with the neuroprosthesis than they were without it. Home use of the device for regular function and exercise was reported by over 90% of the participants, and satisfaction with the neuroprosthesis was high.

CONCLUSIONS

The grasping ability provided by the neuroprosthesis is substantial and lasting. The neuroprosthesis is safe, well accepted by users, and offers improved independence for a population without comparable alternatives.

SMAD4 mutations in colorectal cancer probably occur before chromosomal instability, but after divergence of the microsatellite instability pathway

Loss of chromosome 18q21 is well documented in colorectal cancer, and it has been suggested that this loss targets the DCC, DPC4/SMAD4, and SMAD2 genes. Recently, the importance of SMAD4, a downstream regulator in the TGF-beta signaling pathway, in colorectal cancer has been highlighted, although the frequency of SMAD4 mutations appears much lower than that of 18q21 loss. We set out to investigate allele loss, mutations, protein expression, and cytogenetics of chromosome 18 copy number in a collection of 44 colorectal cancer cell lines of known status with respect to microsatellite instability (MSI). Fourteen of thirty-two MSI(-) lines showed loss of SMAD4 protein expression; usually, one allele was lost and the other was mutated in one of a number of ways, including deletions of various sizes, splice site changes, and missense and nonsense point mutations (although no frameshifts). Of the 18 MSI(-) cancers with retained SMAD4 expression, four harbored missense mutations in the 3' part of the gene and showed allele loss. The remaining 14 MSI(-) lines had no detectable SMAD4 mutation, but all showed allele loss at SMAD4 and/or DCC. SMAD4 mutations can therefore account for about 50-60% of the 18q21 allele loss in colorectal cancer. No MSI(+) cancer showed loss of SMAD4 protein or SMAD4 mutation, and very few had allelic loss at SMAD4 or DCC, although many of these MSI(+) lines did carry TGFBIIR changes. Although SMAD4 mutations have been associated with late-stage or metastatic disease, our combined molecular and cytogenetic data best fit a model in which SMAD4 mutations occur before colorectal cancers become aneuploid/polyploid, but after the MSI(+) and MSI(-) pathways diverge. Thus, MSI(+) cancers may diverge first, followed by CIN(+) (chromosomal instability) cancers, leaving other cancers to follow a CIN(-)MSI(-) pathway.

Peculiar velocity surveys: optimal moments analysis

A new formalism to analyze peculiar velocity surveys is presented. Results from these surveys are shown to be dominated by small-scale noise, aliasing, and incomplete cancellations. The formalism allows us to filter out the signal from scales that are not of interest and thus provides us with a clean signal that probe large scales. We use maximum likelihood techniques to analyze the filtered data and compare it to the analysis of the full dataset. The filtered analysis gives a much better parameter estimation than the full analysis, leading us to conclude that, indeed, the large-scale signal is obscured by small-scale noise.

Strategic management simulations is a novel way to measure resident competencies

BACKGROUND

The Strategic Management Simulation (SMS) has been used extensively to test and train higher cognitive functions in persons who occupy professional and leadership positions (i.e., skills like those needed by a surgeon).

METHODS

The SMS was used to predict surgical residents' competency in decision making. Skills required for integrative surgical decision making including critical thinking, crisis management, flexibility, factual knowledge, and team building were assessed. Surgical residents with at least 2 years of experience participated. In additional, attending faculty familiar with the residents' work evaluated each resident with a standard comprehensive rating scale. Simulation performance on multiple measures was compared with faculty ratings.

RESULTS

A number of measures obtained on simulation performance (eg, activity level, response speed, initiative, adequate usage of and appropriate search for relevant information) generated high correlations with comprehensive faculty assessment (eg, measures of crisis management, team interactions, flexibility of approach).

CONCLUSION

The simulation technique is able to accurately assess performance of surgical residents (on a number of parameters) in a relatively brief time period. Simulation data were highly similar to faculty ratings that were based on at least 2 years of experience with the resident.

A prototype haptic lumbar puncture simulator

Lumbar punctures (LP) are complex, precise procedures done to obtain cerebro-spinal fluid from a patient for diagnostic purposes. Incorrect techniques resulting from inadequate training or supervision can result in sub-optimal outcomes. As tactile feedback is crucial for a successful lumbar puncture, this procedure serves as an ideal candidate for the development of a haptic training simulator. The intent of this project is to engineer a force feedback LP simulator that provides a safe method of training students (medical students, residents, or trained physicians) for an actual LP procedure on a patient.

Environmental Dependence of the Fundamental Plane of Galaxy Clusters

Galaxy clusters approximate a planar distribution in a three-dimensional parameter space that can be characterized, for example, by an optical luminosity, half-light radius, and X-ray luminosity. We find the nearest neighbor clusters for those common to either of two previous fundamental-plane studies and a high-quality cluster redshift catalog. Examining scatter about one plane in parameter space, we find a 2 sigma result that it is dependent on the nearest neighbor distance. Study of another sample of X-ray clusters shows that those with high central gas densities are systematically (2.5 sigma) closer to neighbor clusters. These results suggest a possible explanation for recent evidence that X-ray cooling flow clusters reside in crowded environments.

The type of somatic mutation at APC in familial adenomatous polyposis is determined by the site of the germline mutation: a new facet to Knudson's 'two-hit' hypothesis

APC is often cited as a prime example of a tumor suppressor gene. Truncating germline and somatic mutations (or, infrequently, allelic loss) occur in tumors in FAP (familial adenomatous polyposis). Most sporadic colorectal cancers also have two APC mutations. Clues from attenuated polyposis, missense germline variants with mild disease and the somatic mutation cluster region (codons 1,250-1,450) indicate, however, that APC mutations might not result in simple loss of protein function. We have found that FAP patients with germline APC mutations within a small region (codons 1,194-1,392 at most) mainly show allelic loss in their colorectal adenomas, in contrast to other FAP patients, whose 'second hits' tend to occur by truncating mutations in the mutation cluster region. Our results indicate that different APC mutations provide cells with different selective advantages, with mutations close to codon 1,300 providing the greatest advantage. Allelic loss is selected strongly in cells with one mutation near codon 1,300. A different germline-somatic APC mutation association exists in FAP desmoids. APC is not, therefore, a classical tumor suppressor. Our findings also indicate a new mechanism for disease severity: if a broader spectrum of mutations is selected in tumors, the somatic mutation rate is effectively higher and more tumors grow.

Incidence of operative procedures on cleft lip and palate patients

The incidence of operative procedures in a group of 374 cleft lip and palate patients was determined by a chart review. These patients were part of a long term study funded by the National Institute of Dental Research at the Lancaster Cleft Palate Clinic. The chart review provided a breakdown of the primary and secondary procedures performed on the patients. Although the secondary procedures carried out were underestimated in this study, it is clear that these operations comprise a major component of the successful treatment of these patients. The results of the study and the implications in today's managed care environment are discussed.

Comparative genomic hybridization of breast tumors stratified by histological grade reveals new insights into the biological progression of breast cancer

How does breast cancer progress? There is evidence both to support (S. W. Duffy et al., Br. J. Cancer, 64: 1133-1138, 1991; R. Rajakariar et al., Br. J. Cancer, 71: 150-154, 1995) and refute (M. Hakama et al., Lancet, 345: 221-224, 1995; R. R. Millis et al., Eur. J. Cancer, 34: 548-553, 1998) the hypothesis of dedifferentiation; the theory that as breast cancers grow they evolve from well differentiated (grade I) to poorly differentiated (grade III) tumors. We provide evidence to support the view that the majority of grade I tumors do not progress to grade III tumors. Comparative genomic hybridization was used to screen entire genomes of a large sample (40 grade I and 50 grade III) of invasive ductal breast carcinomas, stratified by grade. We found distinct genetic differences between grade I and grade III tumors. Significantly, we found that 65% of grade I tumors lost the long arm of chromosome 16 compared with only 16% of grade III tumors. This pattern of loss leads us to conclude that the majority of grade I tumors do not progress to grade III tumors. These findings have important implications because they suggest that different breast tumor grades may have distinct molecular origins, pathogenesis, and behavior and, therefore, potentially present distinct molecular targets for research and treatment.

The usefulness of handheld computers in a surgical group practice

We designed a system using hand-held computers allowing physicians in the hospital setting to access their surgical schedules, to track patients in multiple hospitals, and to quickly enter billing information. The physicians would then update their schedules and pass billing information electronically when they returned to the office. The system was successfully implemented, it was well accepted by clinicians and staff users, and it showed an increased capture of charges. Whether an economically important effect on the number of days to post hospital charges will be evident after follow-up data has been collected.

Impact of steady-state and exercise modality on estimating oxygen consumption in men with and without coronary artery disease

PURPOSE

This study examined the effect of steady-state on the ability of 15 men with coronary artery disease (CAD) and 13 men without CAD disease (non-CAD) to reach a rate of oxygen consumption (VO2) relative to population norms during treadmill and cycle ergometry exercise testing.

METHODS

Subjects completed a maximal graded exercise test on the treadmill and cycle ergometry involving 3-minute stages and a submaximal exercise test involving 6-minute stages to 80% of maximal effort. Estimates of VO2 were derived from commonly cited clinical estimation equations.

RESULTS

Only the Foster equation accurately estimated maximal VO2 during a treadmill graded exercise test in patients with CAD. However, each of cited clinical equations accurately estimated maximal VO2 during a treadmill graded exercise test in the non-CAD group. No equation accurately estimated VO2 at submaximal efforts during treadmill exercise for either group. Cycle ergometry estimation equations accurately estimated VO2 in both groups at maximal effort, but were inconsistent at submaximal efforts. Both the CAD and the non-CAD group reached steady-state VO2 within 3 minutes, at submaximal workloads.

CONCLUSIONS

The inability to attain an expected VO2 during exercise did not seem related to steady-state VO2 because both CAD and non-CAD groups readily reached steady-state VO2, though the estimation of VO2 remained inaccurate for most treadmill estimation equations. Because VO2 was accurately estimated for cycle ergometry exercise, estimation accuracy seems to be influenced by exercise modality.

Primary stenting of atherosclerotic renal artery ostial stenosis

Percutaneous transluminal angioplasty for atherosclerotic ostial lesions of the renal arteries has resulted in high restenosis rates. Recent reports of angioplasty with intravascular stenting show improved results over angioplasty alone. The purpose of this study is to review the results of primary stenting of ostial renal artery stenosis at our institution. Twenty one patients (11 men, 10 women, age 63 +/- 11 years), with atherosclerotic renal artery ostial stenosis in association with hypertension or renal insufficiency underwent renal angioplasty with primary stenting during a 2-year period. Medical records were reviewed for indications, technical success, complications, restenosis, response of hypertension and response of renal insufficiency. A technical success was defined as a normal postprocedure arteriogram with no residual stenosis and no residual gradient. Restenosis was defined as > or =60% diameter reduction identified by arteriography, or duplex scan demonstrating a renal artery to aortic ratio of > or =3.5. Thirty-three stents were placed in 25 arteries with four patients having bilateral procedures. All patients were hypertensive. Nine patients (43%) had chronic renal insufficiency (creatinine > or =1.5 mg/dl). One patient was on hemodialysis. The immediate technical success rate was 95%. Six complications occurred in four patients (two pseudoaneurysms, two dissections requiring additional stents, renal failure, and atheroembolization). Mean arterial blood pressure improved from 117 +/- 13.4 to 103 +/- 12.8 mmHg (p = 0.002) after stenting. Serum creatinine levels decreased from 1.48 +/- 0.57 to 1.31 +/- 0.41 (p = 0.07). Eight patients developed restenosis. The mean follow up was 13 +/- 7 months. Life table analysis showed a cumulative restenosis rate of 65 +/- 18% at 24 months. We advise caution in the application of renal stenting for the treatment of ostial lesions, particularly in patients for whom standard surgical revascularization options are available.

Characterization of cryptic rearrangements and variant translocations in acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) is typified by the reciprocal translocation, t(15; 17)(q22; q21), leading to the formation of PML-RARalpha and RARalpha-PML fusion genes. We have characterized 7 cases of morphologic APL found to lack the t(15; 17) on conventional cytogenetic assessment. In 6 of 7 cases, cryptic PML-RARalpha rearrangements were identified by reverse transcriptase-polymerase chain reaction and fluorescent in situ hybridization (FISH); whereas, in the remaining patient, APL was associated with the variant translocation, t(11; 17)(q23; q12-21), leading to the formation of PLZF-RARalpha and RARalpha-PLZF fusion genes. In each of the cases with cryptic PML-RARalpha rearrangements, PML-RARalpha transcripts were detected in the absence of RARalpha-PML, consistent with the concept that PML-RARalpha is the critical oncogenic fusion protein. In 4 of these cases with evaluable metaphase spreads, the occurrence of a nonreciprocal translocation was confirmed by FISH with sole formation of the PML-RARalpha fusion gene; in 3 cases with morphologically normal chromosomes 15 and 17, RARalpha was inserted into PML on 15q, whereas in the remaining patient the PML-RARalpha fusion arose due to insertion of 15q-derived material including PML into RARalpha on 17q. Immunofluorescence studies were performed using antibodies raised against PML and PIC 1, a ubiquitin-homology domain protein previously identified as an interaction partner of PML. In acute myeloid leukemia (AML) of subtypes other than M3, PIC 1 was localized to the nuclear membrane and colocalized with PML within discrete nuclear bodies. In APL cases with cryptic PML-RARalpha rearrangements, the characteristic microparticulate pattern of PML staining was detected with partial colocalization with PIC 1, indicative of disruption of the nuclear bodies; whereas in t(11; 17)-associated APL, PML and PIC 1 remained colocalized within discrete nuclear bodies, as observed in non-APL cases. Although deregulation of the putative growth suppressor PML and delocalization of other nuclear body constituents have been advocated to play a key role in the development of t(15; 17)-associated APL, the present study shows that disruption of PML nuclear bodies per se is not a prerequisite for the pathogenesis of APL.

Chromosomal localization, gene structure and transcription pattern of the ORFX gene, a homologue of the MHC-linked RING3 gene

We have mapped the human ORFX gene to chromosome 9q34 and determined its complete gene structure. Comparison with RING3, the human MHC-linked homologue on 6p21.3, shows the two gene structures to be highly conserved but with an approximate threefold expansion in the ORFX introns. RING3 and ORFX are found to be ubiquitously expressed in human adult and foetal tissues. Evidence suggests that the two genes may have arisen from an ancient duplication in a common ancestral chromosome.

Primary care management of common dermatologic disorders in women. Pharmacologic considerations

This article describes the clinical management of dermatologic disorders most commonly encountered in the primary care setting. The common presenting clinical signs and symptoms are reviewed, and the initial laboratory tests that may establish the diagnosis are recommended. Pharmacologic and nonpharmacologic treatments are reviewed. Diagnosis and management of disorders of the sebaceous and apocrine glands, disorders of the hair and pigmentation, fungal, viral, and bacterial infections, dermatitis, and infestations are discussed. A review of the care of skin burns and wounds is included as well as the diagnosis and management of urticaria.

Treadmill aerobic exercise training reduces the energy expenditure and cardiovascular demands of hemiparetic gait in chronic stroke patients. A preliminary report

BACKGROUND AND PURPOSE

Elevated energy costs of hemiparetic gait contribute to functional disability after stroke, particularly in physically deconditioned older patients. We investigated the effects of 6 months of treadmill aerobic exercise training on the energy expenditure and cardiovascular demands of submaximal effort ambulation in stroke patients with chronic hemiparetic gait.

METHODS

Nine older stroke patients with chronic hemiparetic gait were enrolled in a 6-month program of low-intensity aerobic exercise using a graded treadmill. Repeated measures of energy expenditure based on steady state oxygen consumption during a standardized 1-mph submaximal effort treadmill walking task were performed before and after training.

RESULTS

Six months of exercise training produced significant reductions in energy expenditure (n = 9; 3.40 +/- 0.27 versus 2.72 +/- 0.25 kcal/min [mean +/- SEM]; P < .005) during a given submaximal effort treadmill walking task. Repeated measures analysis in the subset of patients (n = 8) tested at baseline and after 3 and 6 months revealed that reductions in energy expenditure were progressive (F = 11.1; P < .02) and that exercise-mediated declines in both oxygen consumption (F = 9.7; P < .02) and respiratory exchange ratio (F = 13.4; P < .01) occurred in a strong linear pattern. These stroke patients could perform the same standardized submaximal exercise task at progressively lower heart rates after 3 months (96 +/- 4 versus 87 +/- 4 beats per minute) and 6 months of training (82 +/- 4 beats per minute; F = 35.4; P < .002).

CONCLUSIONS

Six months of low-intensity treadmill endurance training produces substantial and progressive reductions in the energy expenditure and cardiovascular demands of walking in older patients with chronic hemiparetic stroke. This suggests that task-oriented aerobic exercise may improve functional mobility and the cardiovascular fitness profile in this population.

Word frequency analysis of dictated clinical data: a user-centered approach to the design of a structured data entry interface

The design of a functional interface for direct entry of physical exam data by physicians remains a formidable challenge for developers of clinical information systems. Many developers use a theoretical approach, basing the interface on a model of the structure of the information and of the user-system interaction that is developed with one or more clinical domain expert(s). We explored the use of empirical analysis as a basis for the design of a structured data entry (SDE) interface. A collection of physical examination data from actual trauma patients, dictated by trauma surgeons, was used for the analysis. Using simple parsers written in Visual BASIC, we used word frequency analysis (WFA) and manual editing to identify the frequencies of unique terms used by physicians in recording 688 HEENT and 712 LUNG physical exams. A second-pass WFA was used to determine associated descriptive terms. A simple SDE interface was created based on the results of these analyses. The interface was then evaluated by assessing the extent to which the HEENT and LUNG segments of similar physical exams could be fully recorded using the empirically-based SDE interface. Using this interface, 68% of 200 trial HEENT exams, and 85% of 200 trial LUNG exams could be fully recorded. The interface was also considered helpful in recording substantial portions of the remainder of the exams. We believe that WFA can be a useful tool for finding empirical basis for SDE design.

Mapping of the genes encoding human inducible and endothelial nitric oxide synthase (NOS2 and NOS3) to the pericentric region of chromosome 17 and to chromosome 7, respectively

Nitric oxide (NO) is an important molecular messenger regulating the functions of a wide variety of cells and tissues. NO is synthesized from L-arginine by a variety of isoforms of the enzyme nitric oxide synthase (NOS). We have used Southern blotting analysis on DNAs obtained from a panel of human-rodent hybrid cell lines to map the gene encoding the inducible NOS (NOS2) to chromosome 17cen-17q11 and the gene encoding the endothelial form of NOS (NOS3) to chromosome 7. Fluorescence in situ hybridization using a NOS2 probe gave several signals in the 17p11-q11 pericentromeric region.

Regional localization of the gene coding for human brain nitric oxide synthase (NOS1) to 12q24.2-->24.31 by fluorescent in situ hybridization

The human gene for brain nitric oxide synthase (NOS1) was previously assigned to chromosome 12 by analysis of a panel of somatic cell hybrids. We report here the refinement of this localization to 12q24.2-->24.31 by fluorescent in situ hybridization.

Does the medical literature contain the evidence to answer the questions of primary care physicians? Preliminary findings of a study

OBJECTIVE

To assess the quality of information retrieved in MEDLINE searches performed to answer clinical questions of primary care physicians.

SETTING

Ambulatory rural and nonrural practices.

PARTICIPANTS

Active, non-academic primary care physicians; professional medical librarians, a general internist.

DESIGN

Descriptive study in 3 stages: 1) Office Interviews, to record questions that arise in primary care practice; 2) Online Searches, to locate information that might answer these questions; and 3) Critical Appraisal to determine the quality of the information contained in the articles retrieved.

MAIN RESULTS

Of 74 articles judged by clinicians to be relevant to their questions, 2 were critical reviews, 14 reported results of randomized controlled trials, and 4 reported results of cohort studies. The remainder contained weaker evidence: 1 reported results of a case-control study, 6 were longitudinal case series, 13 were cross-sectional descriptions of disease, 12 were cross-sectional descriptions of diagnostic testing, and 22 were review articles which did not meet criteria for a critical review.

CONCLUSION

Searching the medical literature to answer the questions of primary care physicians was successful in retrieving recent, relevant information, and often provided "a clear answer" to the question, but the cost of using bibliographic retrieval was high, and fewer than a third of the articles retrieved contained high quality evidence.

Cloning and chromosome mapping of the human interleukin-1 receptor antagonist gene

By screening a human genomic library with an interleukin-1 receptor antagonist (IL-1ra) cDNA probe, we have isolated a 15 kb clone which contains the entire coding region of the gene as expressed in monocytes, and includes 6 kb of 5'-upstream sequence. The gene contains four exons which code for the secreted form of the IL-1ra, however, our clone does not contain the alternative first exon used to generate an intracellular form of the protein as the protein as found in epithelial cells. Analysis of the sequence reveals a consensus TATA box, and three Alu repeats, two of which are in the upstream region and one in intron 3. The sequence also reveals an 86 bp motif tandomly repeated four times within intron 2, and may reflect the polymorphism known to exist in this region of the gene. By in-situ fluorescence hybridization we have shown that the IL-1ra gene is found on the long arm of chromosome 2 and maps to 2q13-14.1. Previous studies have revealed that IL-1 alpha, and IL-1 beta and both type I and type II forms of the IL-1 receptor all map close to this region of chromosome 2.

Epidural vs. Intramuscular Oxymorphone Analgesia after Thoracotomy in Dogs

Oxymorphone was administered epidurally (0.1 mg/kg) or intramuscularly (IM) (0.2 mg/kg) to 16 dogs undergoing thoracotomy, to compare the analgesic effectiveness. Heart rate, respiratory rate, systolic and diastolic blood pressure, and pain score were measured hourly. Arterial blood gases were measured at hour 1. A single dose of oxymorphone injected epidurally provided analgesia for up to 10 hours, whereas the IM route provided a comparable effect for less than 2 hours. There were statistically significant increases in heart rate, and systolic and diastolic blood pressures at hour 2 in the dogs treated IM over the dogs treated epidurally. We conclude that epidurally administered oxymorphone is highly effective in alleviating pain after thoracotomy in dogs and provides longer lasting analgesia than the IM route.