Evaluation of the Metasin assay for intraoperative assessment of sentinel lymph node metastases in breast cancer

AIMS

Sentinel lymph node (SLN) biopsy is the preferred surgical technique for staging the axilla in clinically node-negative breast cancer. Accurate intraoperative staging allows for the immediate performance of an axillary clearance in node-positive patients. We assessed the Metasin assay for the intraoperative analysis of SLNs in a prospective evaluation of 250 consecutive patients undergoing intraoperative SLN analysis at the Breast Unit, University Hospital, Southampton, UK.

METHODS

Metasin uses a quantitative reverse transcription PCR to detect two markers of metastasis: cytokeratin 19 (CK19) an epithelial marker and mammaglobin (MGB) a breast specific marker. Metasin results were compared with the results from routine paraffin block histopathology.

RESULTS

Metasin was robust, with a failure rate of <1%, and demonstrated excellent accuracy and reproducibility. The average turnaround time for the Metasin assay was 42 min, the largest variable being the number of nodes assayed. A total of 533 SLNs were evaluated with 75 patients testing positive for MGB and/or CK19. Based on the analysis of individual SLNs, the overall concordance between Metasin and histology was 92.3% (sensitivity 88.7%, specificity 92.9%). When adjusted for tissue allocation bias, the concordance was 93.8% (sensitivity 89.8%, specificity 94.6%). In this evaluation, 57/250 patients (23%) proceeded to axillary clearance based on Metasin results and were considered spared a second operative procedure.

CONCLUSIONS

Metasin has proven to be an accurate, reproducible and reliable laboratory test. The analysis time is acceptable for intraoperative use, and in comparison to routine histology demonstrates acceptable concordance, sensitivity and specificity.

Intrinsic nanostructure in Zr2-xFe4Si16-y(x = 0.81, y = 6.06)

We present a study of the crystal structure and physical properties of single crystals of a new Fe-based ternary compound, Zr2-xFe4Si16-y(x = 0.81, y = 6.06). Zr1.19Fe4Si9.94 is a layered compound, where stoichiometric β-FeSi2-derived slabs are separated by Zr-Si planes with substantial numbers of vacancies. High resolution transmission electron microscopy (HRTEM) experiments show that these Zr-Si layers consist of 3.5 nm domains where the Zr and Si vacancies are ordered within a supercell sixteen times the volume of the stoichiometric cell. Within these domains, the occupancies of the Zr and Si sites obey symmetry rules that permit only certain compositions, none of which by themselves reproduce the average composition found in x-ray diffraction experiments. Magnetic susceptibility and magnetization measurements reveal a small but appreciable number of magnetic moments that remain freely fluctuating to 1.8 K, while neutron diffraction confirms the absence of bulk magnetic order with a moment of 0.2μB or larger down to 1.5 K. Electrical resistivity measurements find that Zr1.19Fe4Si9.94 is metallic, and the modest value of the Sommerfeld coefficient of the specific heat γ = C/T suggests that quasi-particle masses are not particularly strongly enhanced. The onset of superconductivity at Tc ≃ 6 K results in a partial resistive transition and a small Meissner signal, although a bulk-like transition is found in the specific heat. Sharp peaks in the ac susceptibility signal the interplay of the normal skin depth and the London penetration depth, typical of a system in which nano-sized superconducting grains are separated by a non-superconducting host. Ultra low field differential magnetic susceptibility measurements reveal the presence of a surprisingly large number of trace magnetic and superconducting phases, suggesting that the Zr-Fe-Si ternary system could be a potentially rich source of new bulk superconductors.

Sucker bet or sure thing: A critical analysis of sports lotteries

A paradox currently exists regarding legal sports gambling in North America: various forms are flourishing in Nevada, Oregon, and several Canadian provinces, while at the same time the United States Congress is conducting hearings on two bills that would prohibit any new state-sponsored sports gambling initiatives. This study examines the issue of why some jurisdictions are enthusiastic about legal sports gambling while others strongly resist the concept. In reviewing these divergent viewpoints, a case study of the newfledged Canadian "Sport Select" gambling format is presented. This example is used to highly the perils and payoffs of a typical state-sponsored sports gambling scheme, with a view toward broadening our understanding of how they work and how they might be fairer to the public.

Disordered gambling among higher-frequency gamblers: who is at risk?

BACKGROUND

When gambling opportunities are made available to the public in a given jurisdiction, some individuals participate occasionally and others more frequently. Among frequent gamblers, some individuals develop problematic involvement and some do not. This study addresses the association among demographic and social risk factors, frequency of gambling and gambling disorders.

METHOD

Data from an adult community sample (n=1372) were used to identify risk factors for higher-frequency gambling and disordered gambling involvement.

RESULTS

Individuals with higher intelligence, older individuals and more religious individuals were less frequent gamblers. Males, single individuals and those exposed to gambling environments (friends and family who gamble) and those who started to gamble at a younger age were more frequent gamblers. Excitement-seeking personality traits were also higher among more frequent gamblers. A different set of risk factors was associated with the likelihood of gambling disorder among these higher-frequency gamblers. These variables included mental health indicators, childhood maltreatment and parental gambling involvement. Among higher-frequency gamblers, individuals who smoke cigarettes, those with a diagnosis of alcohol or drug dependence or obsessive-compulsive disorder, those with higher anxiety or depression and those with higher impulsivity and antisocial personality traits were more likely to report gambling-related problems. These individuals were also more likely to report gambling on electronic gambling machines (e.g. slot machines).

CONCLUSIONS

These data suggest a model in which higher-frequency gambling, particularly with electronic gambling machines, when combined with any type of emotional vulnerability increased the likelihood of gambling disorder.

ADHD is associated with a "Western" dietary pattern in adolescents

OBJECTIVE

To examine the relationship between dietary patterns and ADHD in a population-based cohort of adolescents.

METHOD

The Raine Study is a prospective study following 2,868 live births. At the 14-year follow-up, the authors collected detailed adolescent dietary data, allowing for the determination of major dietary patterns using factor analysis. ADHD diagnoses were recorded according to International Classification of Deiseases, 9th Revision coding conventions. Logistic regression was used to assess the relationship between scores for major dietary pattern and ADHD diagnoses.

RESULTS

Data were available for 1,799 adolescents, and a total of 115 adolescents had an ADHD diagnosis. Two major dietary patterns were identified: "Western" and "Healthy." A higher score for the Western dietary pattern was associated with ADHD diagnosis (odds ratio=2.21, 95% confidence interval=1.18, 4.13) after adjusting for known confounding factors from pregnancy to 14 years. ADHD diagnosis was not associated with the "Healthy" dietary pattern.

CONCLUSION

A Western-style diet may be associated with ADHD.

Perturbation and change in coral reef communities

Ninety-six percent of surveyed shallow-water Dry Tortugas reef corals died during the severe winter of 1976-1977. Data from skeletal stains indicate that death occurred during the mid-January intrusion of 14 degrees C water onto the reef. In deeper water, community parameters such as percent cover, species number, and relative abundance showed no significant change. However, an analysis of competitive interactions at the growing edges of adjacent colonies reveals a 70% reduction in space competition during this environmental disturbance. These results can explain high variability in the growth rate of Floridian reefs and demonstrate the importance of obtaining long-term spatial information to interpret successional dynamics of complex communities.

Molecular detection of a novel human influenza (H1N1) of pandemic potential by conventional and real-time quantitative RT-PCR assays

BACKGROUND

Influenza A viruses are medically important viral pathogens that cause significant mortality and morbidity throughout the world. The recent emergence of a novel human influenza A virus (H1N1) poses a serious health threat. Molecular tests for rapid detection of this virus are urgently needed.

METHODS

We developed a conventional 1-step RT-PCR assay and a 1-step quantitative real-time RT-PCR assay to detect the novel H1N1 virus, but not the seasonal H1N1 viruses. We also developed an additional real-time RT-PCR that can discriminate the novel H1N1 from other swine and human H1 subtype viruses.

RESULTS

All of the assays had detection limits for the positive control in the range of 1.0 x 10(-4) to 2.0 x 10(-3) of the median tissue culture infective dose. Assay specificities were high, and for the conventional and real-time assays, all negative control samples were negative, including 7 human seasonal H1N1 viruses, 1 human H2N2 virus, 2 human seasonal H3N2 viruses, 1 human H5N1 virus, 7 avian influenza viruses (HA subtypes 4, 5, 7, 8, 9, and 10), and 48 nasopharyngeal aspirates (NPAs) from patients with noninfluenza respiratory diseases; for the assay that discriminates the novel H1N1 from other swine and human H1 subtype viruses, all negative controls were also negative, including 20 control NPAs, 2 seasonal human H1N1 viruses, 2 seasonal human H3N2 viruses, and 2 human H5N1 viruses.

CONCLUSIONS

These assays appear useful for the rapid diagnosis of cases with the novel H1N1 virus, thereby allowing better pandemic preparedness.

Hydatid pulmonary emboli

A case of secondary hydatosis, initially misdiagnosed as pulmonary metastases, is presented. The dissemination of hydatid cysts within the lungs in this case was the consequence of direct rupture of a hepatic hydatid into the inferior vena cava. A brief overview of the pathophysiology of hydatid disease, including a discussion of the types of hydatid rupture (contained, communicating and direct), is presented.

Establishment of short-term primary human prostate xenografts for the study of prostate biology and cancer

Human tissue xenograft models are currently the only tool for conducting in vivo analyses of intact human tissue. The goal of the present study was to develop reliable methods for successful generation of short-term primary tissue xenografts from benign and tumor-derived human prostate tissue. Primary human prostate xenografts were established in athymic nu/nu mice from eight of eight benign and five of five prostate cancer tissues, collected from a total of 10 patients who underwent radical prostatectomy for the treatment of prostate cancer. An average of 13 xenografts was established per specimen. Two tissue specimens were cryopreserved for >1 month before successful generation of prostate xenografts. After 1 month in vivo, xenograft tissues were harvested and examined regarding: gross evidence of vascularization; tissue morphology; proliferation; apoptosis; and expression of androgen receptor, prostate-specific antigen, and high molecular weight cytokeratins specific for basal cells in the prostate. Direct comparison of the original tissue specimen and the 1-month xenografts revealed similar histology; similar apoptotic and proliferative fractions in most cases; and comparable expression levels and expression patterns of androgen receptor, prostate-specific antigen, and high molecular weight cytokeratins. These data demonstrate that primary human prostate xenografts, benign and malignant, can be established routinely from human prostate tissue surgical specimens, and that the xenografts maintain tissue architecture and expression of key prostatic markers. The development of this methodology, including the technique for cryopreservation of human tissue, will allow multiple (successive) analyses of human prostate tissue to be conducted throughout time using a tissue sample derived from a single patient; and simultaneous analysis of human prostate tissues derived from a cohort of patients.

Aberrant cell cycle checkpoint function in transformed hepatocytes and WB-F344 hepatic epithelial stem-like cells

Cell cycle checkpoints are barriers to carcinogenesis as they function to maintain genomic integrity. Attenuation or ablation of checkpoint function may enhance tumor formation by permitting outgrowth of unstable cells with damaged DNA. To examine the function of cell cycle checkpoints in rat hepatocarcinogenesis, we analyzed the responses of the G (1), G (2) and mitotic spindle assembly checkpoints in normal rat hepatocytes, hepatic epithelial stem-like cells (WB-F344) and transformed derivatives of both. Normal rat hepatocytes (NRH) displayed a 73% reduction in the fraction of nuclei in early S-phase 6-8 h following 8 Gy of ionizing radiation (IR) as a quantitative measure of G (1) checkpoint function. Chemically and virally transformed hepatocyte lines displayed significant attenuation of G (1) checkpoint function, ranging from partial to complete ablation. WB-F344 rat hepatic epithelial cell lines at low, mid and high passage levels expressed G (1) checkpoint function comparable with NRH. Only one of four malignantly transformed WB-F344 cell lines displayed significant attenuation of G (1) checkpoint function. Attenuation of G (1) checkpoint function in transformed hepatocytes and WB-F344 cells was associated with alterations in p53, ablated/attenuated induction of p21 (Waf1) by IR, as well as aberrant function of the spindle assembly checkpoint. NRH displayed 93% inhibition of mitosis 2 h after 1 Gy IR as a quantitative measure of G (2) checkpoint function. All transformed hepatocyte and WB-F344 cell lines displayed significant attenuation of the G (2) checkpoint. Moreover, the parental WB-F344 line displayed significant age-related attenuation of G (2) checkpoint function. Abnormalities in the function of cell cycle checkpoints were detected in transformed hepatocytes and WB-F344 cells at stages of hepatocarcinogenesis preceding tumorigenicity, sustaining a hypothesis that aberrant checkpoint function contributes to carcinogenesis.

Chromatographic separations as a prelude to two-dimensional electrophoresis in proteomics analysis

Current methods of proteome analysis rely almost solely on two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) followed by the excision of individual spots and protein identification using mass spectrometry (MS) and database searching. 2-D PAGE is denaturing in both dimensions and, thus, cannot indicate functional associations between individual proteins. Moreover, less abundant proteins are difficult to identify. To simplify the proteome, and explore functional associations, nondenaturing anion exchange column chromatography was used to separate a soluble protein extract from Escherichia coli. Successive fractions were then analysed using 2-D PAGE and selected spots from both the gels for the start material and the fractionated material were quantified and identified by peptide mass fingerprinting using a MALDI-TOF mass spectrometer. Enrichments of up to 13-fold were attained for individual protein spots and peptide mass fingerprints were of significantly higher quality after chromatographic separation. The marked anomalies between predicted p/and column elution position contrasted with the almost perfect correlation with migration distance on isoelectric focusing (IEF) and were explored further for basic proteins.

The troubled self in women with severe eating disorders (anorexia nervosa and bulimia nervosa). A study using interviews, self-reports, and percept-genetic methods

Fifteen anorectic (A) and 13 bulimic (B) patients aged 20-49 years, all seriously ill, and 21 controls were studied, using a half-structured interview, the Tennessee Self Concept Scale, the tachistoscopic Identity Test (IT), and two other percept-genetic tests. The differences between A and B were not particularly pronounced, A patients being on the whole more sensitive and self-directed, and B patients more depressive and object-directed. The IT differentiated between patients and controls very powerfully with regard to alexithymia. A type of response in that test, emphasizing the eyes, was seen as a search for guidance. Descriptions of mother were generally negative.

A novel series of 4-piperidinopyridine and 4-piperidinopyrimidine inhibitors of 2,3-oxidosqualene cyclase-lanosterol synthase

A novel series of 4-piperidinopyridines and 4-piperidinopyrimidines showed potent and selective inhibition of rat 2,3-oxidosqualene cyclase-lanosterol synthase (OSC) (e.g. 26 IC(50) rat = 398 +/- 25 nM, human = 112 +/- 25 nM) and gave selective oral inhibition of rat cholesterol biosynthesis (26 ED(80) = 1.2 +/- 0.3 mg/kg, n = 5; HMGCoA reductase inhibitor simvastatin ED(80) = 1.2 +/- 0.3 mg/kg, n = 5). The piperidinopyrimidine OSC inhibitors have a significantly lower pK(a) than the corresponding pyridine or the previously reported quinuclidine OSC inhibitor series. This indicates that other novel OSC inhibitors may be found in analogues of this series across a broader pK(a) range (6.0-9.0). These series may yield novel hypocholesterolemic agents for the treatment of cardiovascular disease.

Diagnoses, demographics, and utilization of care as encountered by three U.S. Navy general medical officers

U.S. Navy general medical officers (GMOs) are physicians serving as general practitioners. Although exceptions exist, most GMOs are not board-certified in a specialty. They are post-graduate year 1 (PGY-1)-trained, state-licensed physicians analogous to civilian general practitioners. We conducted a retrospective study using data generated from patient visits with active duty males and females from June 1 to 30, 1998, to describe diagnoses, demographics, and utilization of care patterns encountered by three PGY-1-trained GMOs at an ambulatory clinic. A total of 781 patient encounters with 123 diagnoses from a patient population of 3,178 were recorded. This is an average of 260 patient encounters per GMO, at a rate of 2.52 patients seen per patient-care hour. Fifty-seven consultations/referrals were requested (7.3% of encounters, 1.8% of the patient population). Personnel assigned to the clinic accounted for 4.2% of visits (2% of the patient population). Patient satisfaction was rated as "excellent" to "satisfactory," and no significant morbidity was observed at 1.5-year follow-up. With PGY-1 training, GMOs provide primary care to a substantial volume of prescreened patients and treat patients with a majority of diagnoses without referral or unacceptable complications. The role of GMOs, and perhaps other physicians without specialty training (i.e., general practitioners), in selected settings seems valid and may have advantageous medicoeconomic implications for military and civilian managed care systems.

Determination of plasma concentrations of losartan in patients by HPLC using solid phase extraction and UV detection

PURPOSE

To establish a HPLC assay for plasma losartan and its active metabolite EXP3174 to facilitate clinical pharmacokinetic studies.

METHODS

the HPLC system consisted of a 250 x 2 mm i.d. C18 reversed phase column preceded by a 4 x 4 mm guard column, a UV detector set at 254 nm, and an integrator. The mobile phase was a mixture of 0.01 M ammonium phosphate: acetonitrile: methanol (6:3:1) containing 0.02 % sodium azide and 0.04% TEA, with pH adjusted to 3.2. The system was operated isocratically at ambient temperature at a flow rate of 0.3 ml/min. Losartan and its active metabolite EXP3174 were extracted from plasma using C2 bonded silica gel standard solid phase extraction.

RESULTS

recoveries of losartan and EXP3174 from plasma were greater than 70%. Using 0.5 ml of plasma sample, standard curves were linear from 10 to 300 ng/ml (r2 = 0.996 and 0.997 for losartan and EXP 3174, respectively). Sensitivity of the assay was < 10 ng/ml. Intra-and inter-assay variations were < 10 and 15%. respectively. The assay has been successfully applied to measuring plasma concentrations of losartan and EXP3174 in patients receiving a daily dose of losartan (50-100 mg).

CONCLUSION

The HPLC assay has adequate sensitivity, reproducibility, and specificity for clinical pharmacokinetic studies.

Aggression: destructive and constructive aspects

The concept of aggression was long relegated to the shadow of the libido in psychoanalytic theory, placed among the negative affects by some theoreticians, denied the role of a primary drive among leading writers in clinical psychology, brought to the fore as an adaptive force in ethology, and proved to be a decisive factor in the development of psychosomatic ailments. The second part of the paper reviews experiments using projective techniques, showing that highly creative subjects as opposed to ones low in creativity seem inclined to accept their aggressive impulses. A total denial of these impulses has been typical of women with breast cancer.

The fluorescent oxidation products of dihydroxyphenylalanine and its esters

Dihydroxyphenylalanine (DOPA), its methyl ester (DOPAM) and the N-acetylated derivative of the ester (DOPAMNA) are found to undergo rapid oxidation in air-saturated alkaline solution. Some of the products of oxidation exhibit fluorescent emission in the 300-500 nm spectral range and their excitation-emission spectra have been determined in acidic and alkaline aqueous solutions. The spectral distributions and positions of the maxima depend on the pH of the solution. Excitation-emission maxima associated with the protonated phenolic form of the compounds occur at shorter wavelengths than those of the conjugate base. At some pH values the phenolic forms of these molecules are excited and undergo rapid deprotonation in the excited state; as a consequence, emission is observed from the phenolate anion. The fluorescence excitation-emission spectrum of an authentic sample of 3,4-dihydroxycinnamic (caffeic) acid has also been determined and features of the fluorescence spectra of the principal oxidation products are consistent with the presence of 3,4-hydroxycinnamoyl compounds in solutions of oxidized DOPAM and DOPAMNA.

Cytometric quantification of nitrate reductase by immunolabeling in the marine diatom Skeletonema costatum

BACKGROUND

The uptake of nitrate by phytoplankton is a central issue in biological oceanography due to its importance to primary production and vertical flux of biogenic carbon. Nitrate reductase catalyzes the first step of nitrate assimilation, the reduction of NO(3) to NO(2). A cytometric protocol to detect and quantify relative changes in nitrate reductase (NR) protein content of the marine centric diatom Skeletonema costatum is presented.

METHODS

Immunolabeling of NR protein was achieved with polyclonal antibodies raised against S.costatum NR. Antisera specific to a NR protein subunit and to a NR polypeptide sequence were compared, and cytometric results of NR protein abundance were related to Western analyses. Changes in cellular NR abundance and activity were followed during an upwelling simulation experiment in which S. costatum was exposed to a shift from ammonia to nitrate as major nitrogen source.

RESULTS

NR protein could be detected in NO(3)-grown cells and at extremely low levels hardly discernible by Western Blot densiometry in NH(4)-grown cells. The protocol allowed observation of early stages of NR induction during an upwelling simulation. NR abundance increased after the nutrient shift to reach a new physiological "steady-state" 96 hrs later. NR activity exhibited diel variation with maxima at mid-day. NR abundance as estimated by both flow cytometry and Western analysis exhibited a hyperbolic relationship to NR activity. This pattern suggests post-translational activation of NR protein.

CONCLUSIONS

The presented protocol allows the differentiation of NH(4)- versus NO(3)-grown algae as well as the monitoring of early stages in the induction of nitrate assimilatory capacities.

Teaching a long sequence of behavior using whole task training, forward chaining, and backward chaining

Whole task training, forward chaining, and backward chaining techniques were compared in teaching two different 120-step sequences of behavior to college students. In Exp. 1 participants learned a sequence that began with easy movements, progressed through more difficult movements, and ended with easy movements. Whole task training resulted in more errors than either forward or backward chaining. Differences were found in the location of errors. Both whole task training and forward chaining resulted in fewer errors at the beginning of the sequence and backward chaining resulted in fewer errors at the end of the sequence. Because the results of Exp. 1 may have been affected by the increased difficulty of the middle of the sequence, Exp. 2 was undertaken using a sequence of behavior where all segments were of equal difficulty. Whole task training and forward chaining resulted in fewer errors than backward chaining. The location of errors was similar to that found in Exp. 1.

Isolation and partial characterization of an epithelial cell line (RPE-F344) from the regenerating prostate of a normal adult male rat

Normal prostate epithelial cells are difficult to propagate in vitro without experimental immortalization. The goal of this study was to isolate and characterize a propagable epithelial cell line from normal adult rat prostate. Enrichment of proliferation-competent cells was accomplished in vivo by initiating a single cycle of prostatic involution/regeneration. The RPE-F344 cell line was established from an androgen-deprived, involuted prostate four days after the initiation of regeneration by administration of testosterone. The cell line has been cultured in vitro for >50 passages, forms a uniform monolayer in culture, exhibits contact inhibition at confluence, and does not form colonies in soft agar. Immunocytochemical and RT-PCR analyses demonstrated that the RPE-F344 cells express anti-apoptotic genes associated with cell survival, and several growth factor receptors important in prostate development and homeostasis. RPE-F344 cells are p27kip1 negative, telomerase positive, and express high molecular weight cytokeratins specific for prostatic basal cells. They also express low levels of androgen receptor (AR) and prostatic acid phosphatase (PAP); features associated with secretory luminal epithelial cells. RPE-F344 cells are maintained in vitro without androgen supplementation, but addition of 15nM dihydrotesterone (DHT) to the culture media results in a significant but transient enhancement of cellular proliferation. Establishment of RPE-F344-like colonies from rat prostate is limited to the ventral and dorsal lobes of the prostate 2-4 days after initiation of regeneration, suggesting that RPE-F344 cells may originate from a stem cell-like compartment that is responsible for regenerative repopulation.

Mechanical thrombectomy in acute venous thrombosis using an Amplatz thrombectomy device

Three cases of percutaneous mechanical thrombectomy using the Amplatz thrombectomy device are presented. All cases involve the application of the device in a major thoracic or abdominal vein in situations in which chemothrombolysis was contraindicated. The method of operation of the Amplatz thrombectomy device, as well as a brief overview of its clinical applications, are presented.