Neutrophil extracellular traps form predominantly during the organizing stage of human venous thromboembolism development

BACKGROUND

A growing health problem, venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT), requires refined diagnostic and therapeutic approaches. Neutrophils contribute to thrombus initiation and development in experimental DVT. Recent animal studies recognized neutrophil extracellular traps (NETs) as an important scaffold supporting thrombus stability. However, the hypothesis that human venous thrombi involve NETs has not undergone rigorous testing.

OBJECTIVE

To explore the cellular composition and the presence of NETs within human venous thrombi at different stages of development.

PATIENTS AND METHODS

We examined 16 thrombi obtained from 11 patients during surgery or at autopsy using histomorphological, immunohistochemical and immunofluorescence analyses.

RESULTS

We classified thrombus regions as unorganized, organizing and organized according to their morphological characteristics. We then evaluated them, focusing on neutrophil and platelet deposition as well as micro-vascularization of the thrombus body. We observed evidence of NET accumulation, including the presence of citrullinated histone H3 (H3Cit)-positive cells. NETs, defined as extracellular diffuse H3Cit areas associated with myeloperoxidase and DNA, localized predominantly during the phase of organization in human venous thrombi.

CONCLUSIONS

NETs are present in organizing thrombi in patients with VTE. They are associated with thrombus maturation in humans. Dissolution of NETs might thus facilitate thrombolysis. This finding provides new insights into the clinical development and pathology of thrombosis and provides new perspectives for therapeutic advances.

Pedometer-determined physical activity and body composition in Chinese working adults

PURPOSE

Overweight and obesity are prevalent public health problems in many developed and developing regions. Despite extensive documentation on the health benefits of physical activities, little is known about the level of physical activity in the Hong Kong Chinese population. Working adults, in particular, deserve primary attention because they account for the largest proportion of Hong Kong society. The purposes of this study were to investigate pedometer-determined physical activity and examine the associations between physical activity and body composition variables among Chinese working adults in Hong Kong.

DESIGN

This study adopted a descriptive cross-sectional design.

METHODS

A quota sample of 913 working adults from nine major occupational categories was recruited. Demographic characteristics and body composition parameters (weight, height, and waist and hip circumferences) were assessed. Body mass index and waist-to-hip ratio were then calculated. Physical activity was measured in terms of daily walking steps using a pedometer over 1 week. Participants were then categorized as "inactive,""somewhat active," or "regularly active." Descriptive and inferential statistics (analysis of variance, t test, and χ(2) test) were used appropriately.

FINDINGS

Of the 913 participants, 893 returned complete step count records. The completion rate was 97.8%. Participants on average walked 8,661 steps per day, suggesting a "somewhat active" populace. Significant differences were found between the group "regularly active" and "inactive" in most of the body composition parameters. However, a significant weak correlation was found between physical activity and body mass index (r= 0.12, p= .001). Such findings deserve further investigation.

CONCLUSIONS

The Chinese working adults in Hong Kong were found to be somewhat active in physical activity.

CLINICAL RELEVANCE

Findings pose implications for healthcare professionals who are responsible for health promotion in the Asian community setting. Leisure-type physical activity, such as walking, can be incorporated into daily routines.

P2-15-07: The Need for Additional Surgeries to Adequately Excise Early Breast Cancers May Have a Negative Impact on Local Recurrence

Background: Breast conservation surgery (BCS) is considered the standard of care for the treatment of early stage breast cancer (ESBC, AJCC stage 1 and 2). 20 to 50% of patients will require further surgery for positive or close margins. There is recent data suggesting that re-operation can have a negative impact on local and distant recurrences. Our aim is to examine the effects of multiple surgeries to obtain adequate margins on breast cancer recurrence, metastatic disease and survival.

Methods: We reviewed a prospectively maintained breast cancer database at the University Health Network and included all women who had BCS for their first diagnosis of ESBC between January 2004 and December 2007. Patients with neoadjuvant chemotherapy were excluded. We collected patient demographics, surgical pathology, adjuvant therapy and follow up outcome data, which included local recurrence, distant recurrence, cancer-specific survival and overall survival. Clinical and pathologic features were compared using chi-square analyses. Patients who had one lumpectomy were compared to those who had multiple surgeries by using Kaplan-Meier survival curves and log rank test.

Results: Of a total of 744 patients (8 patients had bilateral cancer) 577 (77.6%) had one lumpectomy only (Group 1). 167 (22.4%) patients required further surgery (group 2 = LR+LM+LRM): 83 (11.1%) had a re-excision (LR), 69 (9.3%) had mastectomy (LM) and 15 (2%) had a re-excision followed by a mastectomy (LRM). Thus, a total of 85 (11.4%) patients had mastectomy to achieve adequate margins. All clinicopathologic factors and adjuvant systemic treatments were similar between the two groups except for age and use of adjuvant radiotherapy, which was related to that fact that many of those in group 2 had mastectomy. We observed a difference in disease-free survival favoring patients with lumpectomy only (group 1–3.4% vs. group 2–8.1%, p= 0.01) but there was no difference in distant metastasis (4.5% vs. 5.6%, p=0.56), cancer-specific survival (97.6% vs. 95.6%, p=0.20) and overall survival (6.9% vs 6.3%, p= 0.76) at a median follow up of 4.54 years.

Conclusion: Despite having similar stage, grade, receptor status and adjuvant systemic therapies, having multiple surgeries for primary breast cancer appeared to be associated with decreased disease-free survival but had no difference in rates of distant metastatic disease, cancer-specific survival and overall survival.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-15-07.

Children with learning disabilities in the paediatric clinic, Hospital Tuanku Ja'afar Seremban: an overview

The aim of the study was to document the prevalence of learning disability among the children attending the Paediatric Clinic in Hospital Tuanku Ja'afar Seremban. The demographic distribution of these patients; the age of detection of the problem; the associated medical conditions and types of intervention received by these patients were documented. Patients who were between the ages of five to twelve years were included in the study. Learning disability was divided into three categories: speech and articulation problems, academic skills disorder and other categories which included developmental delay. Children with cerebral palsy were excluded from the study. Out of 1320 patients screened, 355 were found to have learning disorders. Majority were Malays, with the male to female ratio of 1.9:1. Most of the patients stayed in Seremban. The learning problem was most commonly detected at the age of 4 years and below. The commonest type of learning disorder was developmental delay, followed by academic skills disorder, speech and academic skills problems and speech disorders. Problems that were detected early were speech problems and developmental delay. Majority of the children had associated medical conditions. Most of the patients received some form of intervention but 11.3% did not attend any intervention program at all. A strategy should be formulated and implemented to help this group of children.

Cryptococcal osteomyelitis of the femur: a case report and review of literature

Fungal osteomyelitis is a rare opportunistic infection. It exhibits some clinical and radiological similarities to several other bone pathologies. A diagnostic delay may result in significant increase in morbidity. We report a case of a 37-year-old man with underlying hypogammaglobulinaemia presented with isolated cryptococcal osteomyelitis of the femur.

A new mathematical model for irradiance field prediction of upper-room ultraviolet germicidal systems

There has been an increasing interest in the use of upper-room ultraviolet germicidal irradiation (UVGI) system because of its proven disinfection effect for airborne microorganisms. To better design and explore further potential applications of UVGI systems, it is of critical importance to predict the spatial UV intensity in enclosures. In this paper, we developed a new mathematical model to predict spatial radiation intensity for upper-room ultraviolet germicidal irradiation systems. The detail geometries of the lamp and the reflector were removed and replaced by introducing a fictitious irradiation surface near louver slots. The view factor approach was applied to evaluate the UV irradiance in a three-dimensional space with different louver configurations. With this approach no detail meshing of the fixture is required and this leads to significant simplification of the entire systems from modeling perspectives. To validate the model, experiments were performed in a full-scale environmental controlled chamber in which one UVGI fixture was mounted on a sidewall. The UV irradiance was measured by a radiometer. The results predicted by the present model agree very well with the experimental measurements. Factors affect the accuracy of the model was also discussed.

Osteonecrosis of the jaw after oral bisphosphonate for osteoporosis

Bisphosphonates are a common treatment for osteoporosis. Osteonecrosis of the jaw has been associated with the use of bisphosphonates, usually when they have been used parenterally to treat malignancies. Cases associated with oral bisphosphonate as a treatment for osteoporosis are less frequent. We describe two patients exhibiting the clinical manifestations of bisphosphonate-associated osteonecrosis of the jaw. A brief review of the literature on the incidence, possible risk factors, and practice guidelines is also presented.

Animal-type melanoma: a clinical and histopathological study of 22 cases from a single institution

Background Animal-type melanoma is a rare distinct melanoma subtype, characterized by proliferation of heavily pigmented epithelioid and spindled melanocytes that resembles the heavily pigmented melanomas seen in grey horses. While animal-type melanoma is generally considered to be more indolent than conventional melanoma, only a limited number of cases have been reported and, as such, the clinical characteristics of animal-type melanoma are incompletely understood. Objectives To characterize the clinical and histopathological features of animal-type melanoma, and determine any features that may predict outcome. Patients/Methods Data was extracted from a prospectively collected melanoma database (1994-2008), and a retrospective pathology database (1991-2008) for all patients with a diagnosis of both equivocal (8) and unequivocal (14) malignant animal-type melanoma. We reviewed the clinical and histopathological features, including the sentinel lymph node biopsy (SLNB) status. Results A total of 22 patients were identified, with a median age of 35 years. The median Breslow depth was 2.22 mm. A SLNB was performed in 17 patients, eight (47%) were positive. Younger age was associated with: (i) animal-type melanoma with features equivocal for malignancy (median age of 7 vs. 48 years, P = 0.01), and (ii) a negative SLNB (median age 12 vs. 53 years, P = 0.03). Four patients with unequivocal animal-type melanoma developed recurrent metastatic disease, with one patient death. No patient with an equivocal animal-type melanoma or negative SLNB developed recurrent disease; however, this did not reach statistical significance (P = 0.13 and P = 0.09, respectively). Conclusions Animal-type melanoma has a propensity for regional lymphatic metastasis and is rarely capable of disseminated metastatic disease and death. Animal-type melanoma appears to exhibit a spectrum of biological behaviour, with young patient age associated with more indolent disease.

Increased frequency of isolated cleft palate in infants exposed to lamotrigine during pregnancy

BACKGROUND

Pregnancy registries for women taking anticonvulsant drugs have been developed to determine more efficiently the fetal risks of each drug. A total of 722 drug-exposed pregnancies are needed to identify a sevenfold increase in the rate of occurrence of a specific abnormality, such as spina bifida, with a frequency of 1 in 1,000.

METHODS

The infants with major malformations born to the 791 women who had taken lamotrigine as monotherapy and had enrolled in the North American AED Pregnancy Registry were identified. Medical records were obtained from the affected infants' doctors. A total of 107 of the 791 infants or pregnancies were excluded.

RESULTS

A total of 16 (2.3%) of 684 infants exposed to lamotrigine had major malformations that were identified at birth. Five infants (7.3/1,000) had oral clefts: isolated cleft palate (3), isolated cleft lip (1), and cleft lip and palate (1). The rate among the lamotrigine-exposed infants showed a 10.4-fold increase (95% CI: 4.3-24.9) in comparison to 206,224 unexposed infants surveyed at birth at Brigham and Women's Hospital in Boston, where the prevalence of isolated oral clefts was 0.7/1,000. A comparison was made also to 1,623 infants exposed to lamotrigine, as monotherapy, who had enrolled in five other registries. There were four infants with oral clefts: prevalence 2.5/1,000 (RR: 3.8, 95% CI: 1.4-10.0).

CONCLUSIONS

The infant exposed in the first trimester of pregnancy to the anticonvulsant drug lamotrigine has an increased risk to have an isolated cleft palate or cleft lip deformity.

Epidemiology and strain characterization of rotavirus diarrhea in Malaysia

OBJECTIVES

The objectives of the study were to describe the epidemiology and strain characterization of rotavirus (RV), to determine the proportion of hospitalizations for diarrhea attributable to RV among children under 5 years of age, and to estimate the disease burden of RV diarrhea in Malaysia.

METHODS

All children 0-59 months of age admitted for acute gastroenteritis to Kuala Lumpur Hospital (KLH) or Hospital Umum Sarawak (HUS) were surveyed. The periods of surveillance were from February 1, 2001 to April 30, 2003 in KLH and April 1, 2001 to March 31, 2003 for HUS.

RESULTS

The highest rate of RV-associated diarrhea was among children aged 6-17 months, accounting for 55% of RV-associated diarrhea. There was no seasonality observed in either hospital. P[8]G9 strains were predominant, accounting for 73% of all strains in both hospitals, 80% from KLH and 61% from HUS. There was no mortality.

CONCLUSIONS

RV was responsible for 38% of hospitalizations for diarrhea. It was most common in the 6-17 months age group. There was no seasonality observed for RV-associated diarrhea. The most prevalent strain of RV was P[8]G9. The estimated incidence of RV-associated diarrhea was 27 per 10000 population under the age of 5 years per year.

Deaths in children during an outbreak of hand, foot and mouth disease in Peninsular Malaysia--clinical and pathological characteristics

From July through December 1997, 11 previously healthy children in Peninsular Malaysia succumbed to an illness clinically characterised by an acute severe refractory left-ventricular failure, following a brief prodromal illness, in the midst of an outbreak of hand, foot and mouth disease (HFMD), similar to the reported experience in Sarawak and Taiwan. Retrospective reviews of the clinical features and results of laboratory, pathological and virological investigations of cases were conducted. The median age of the 11 case-patients was 31 months (range, 13 to 49 months); 6 were males. A brief prodromal illness of 3 days (range, 2 to 5 days) was characterised by fever (axillary temperature > 38 degrees C) (100%), oral ulcers (72%), extremity rashes (45%) and significant vomiting (55%). Upon hospitalisation, 7 of 11 case-patients had features suggestive of cardiogenic shock, while 4 of 11 case-patients developed shock during hospitalisation as evidenced by marked sustained tachycardia (heart rate > or = 180 beats per minute), poor peripheral pulses and peripheral perfusion, mottled extremities, pulmonary oedema (haemorrhagic pulmonary secretions in 8 of 11 cases during tracheal intubation, often precipitated by conservative crystalloid boluses, and radiographic evidence of acute pulmonary oedema in 5 of 7 cases) and markedly impaired left ventricular function on echocardiographic examination (7 of 7 cases). Three of 4 case-patients had aseptic meningitis while one case-patient also had an acute flaccid paraparesis. Despite supportive therapy, death occurred within a median of 13.4 hours following hospitalization. Post-mortem findings (all 8 specimens examined) consistently demonstrated brain-stem encephalitis with foci of neuronal necrosis and micro-abscesses. None of the 11 specimens examined revealed histological evidence of myocarditis. Enterovirus 71 (EV71) was detected in 10 of 11 case-patients, many (7) from various sterile tissue sites (5 from central nervous tissues). No other viruses were isolated or identified. Clinical features and pathological studies closely paralleled the reported experience in Sarawak and Taiwan. The uniform necropsy findings of necrotizing brain-stem encephalitis coupled with essentially normal myocardial histology, in concert with the concurrent and consistent detection of EV71 points to a primary EV71 encephalitis; as yet unclear neurogenic mechanisms may account for the cardiovascular manifestations.

Interaction of glass-ionomer cements with moist dentin

Glass-ionomer cements (GICs) are regarded as aqueous gels made up of polyalkenoic acid salts containing ion-leachable glass fillers. The consequence of water permeation across the GIC-dentin interface is unknown. This study used SEM, field-emission/environmental SEM (FE-ESEM), and TEM to examine the ultrastructure of GIC-bonded moist dentin. Dentin surfaces bonded with 6 auto-cured GICs were examined along the fractured GIC-dentin interfaces. Additional specimens fractured 3 mm away from the interfaces were used as controls. SEM revealed spherical bodies along GIC-dentin interfaces that resembled hollow eggshells. FE-SEM depicted similar bodies with additional solid cores. Energy-dispersive x-ray analysis and TEM showed that the spherical bodies consisted of a silicon-rich GIC phase that was absent from the air-voids in the controls. The GIC inclusions near dentin surfaces result from a continuation of the GI reaction, within air-voids of the original polyalkenoate matrix, that occurred upon water diffusion from moist dentin.

Small area variations of cancer mortality in Hong Kong--the roles of health care and socio-economic status

Variations of cancer incidence and cancer mortality across small areas in Hong Kong were explored and attempt made to link them to socio-economic differences. The entire Hong Kong population during the period 1984-88 was divided into 65 small areas. The geographic distributions of incidence and mortality for ten most frequent sites of cancers (6 male and 4 female) were analyzed by separating the systematic variance from the random variance. A Poisson regression model was fitted for each cancer using the standardized incidence ratio (SIR) as a covariate for mortality. The geographic variations in SIR for the individual cancers were, in turn, analyzed similarly using a socio-economic score as the covariate. We found a statistically significant systematic variance in mortality for all six male cancers and three of the four female cancers studied. More than 50% of the systematic variance of mortality for nine cancers could be explained by the geographic variations in incidence, suggesting that other factors, like the provision and/or outcomes of health care services, played a minor role. There were statistically significant systematic variances in SIR for all male and female cancers. The socio-economic score accounted for over 50% of the systematic variance for three cancer sites. This study illustrated an approach to explore underlying explanations for the geographic variations of disease incidence and mortality. As more aggregate exposure data become available at the small area level, this type of ecological analysis would help in delineating the contributions of various factors and guide investigators in their search for the etiology background of diseases.

Modelling death rates for carriers of hepatitis B

Hepatitis B carriers who acquired the infection perinatally die from hepatocellular carcinoma (HCC) and cirrhosis at high rates. Published cohort studies are largely limited to males and are too small to estimate the age-specific risk of death. We therefore used routinely collected Hong Kong data to estimate the risks. Deaths were partitioned between carriers and non-carriers, then current life table calculations determined life expectancy and probability of dying from HCC or cirrhosis. HCC is the dominant cause of death for male carriers in middle adulthood with a lifetime risk of 27% for HCC compared to 4% for females. Predicted life expectancy is 72 years for male carriers, compared to 79 years for non-carriers. Female carriers have a life expectancy of 81 years and non-carriers 83 years. This model probably applies to all southern Chinese populations and emigrants with similar life history, and other populations that acquired infection early in life.

p53 gene transfer does not enhance E2F-1-mediated apoptosis in human colon cancer cells

E2F-1 and p53 are sequence specific transcription factors that are intimately involved in the regulation of the cell cycle. In addition to their role in cell cycle control, both E2F-1 and p53 have been identified as tumor suppressors and mediators of apoptosis. We have shown previously that adenoviral-mediated E2F-1 overexpression induces efficient apoptosis in colon adenocarcinoma cells. Previous reports have suggested that E2F-1 and p53 cooperate to mediate apoptosis and therefore, in this study, we examined the efficacy of combination gene therapy using adenovirus vectors expressing E2F-1 and p53 in human colon adenocarcinoma cell lines, HT-29 and SW620 (both mutant p53). Cells were treated by mock infection or infection with adenoviral vectors expressing b-galactosidase (LacZ), E2F-1, p53 or a combination of E2F-1 and p53. IC25 concentrations of each virus were estimated and used for each treatment in order to detect any synergistic or cooperative effects on tumor cell death in the combination therapy. By 5 days post infection, E2F-1-overexpressing cells exhibited growth inhibition and approximately 40-50% cell death in both cell lines. Co-expression of p53 with E2F-1 abrogated E2F-1-mediated growth inhibition and cell death. Cell cycle analysis revealed that overexpression of E2F-1 resulted in an accumulation of cells in G2/M phase, while overexpression of p53 resulted in a G1 phase accumulation. However, co-expression of E2F-1 and p53 counteracted each other as fewer cells accumulated in G1 and G2/M when compared to either p53 or E2F-1 alone. Furthermore, co-expression of p53 with E2F-1 resulted in decreased levels of E2F-1 protein expression. Mechanistically, upregulation of the CDK inhibitory protein, p21(WAF1/CIP1), was demonstrated in HT-29 cells following overexpression of either E2F-1, p53 or the combination E2F-1/p53 therapy. However, in SW620 cells, only the cells infected with Ad-p53 alone or in combination resulted in upregulation of p21(WAF1/CIP1). These results suggest that p53 and p21(WAF1/CIP1) may cooperate to inhibit the expression and activity of E2F-1. In conclusion, combination adenoviral vector-mediated E2F-1 and p53 gene transfer was not therapeutically advantageous in this in vitro model of human colon adenocarcinoma.

Development and characterization of a series of soluble tetrameric and monomeric streptavidin muteins with differential biotin binding affinities

The strong biotin-streptavidin interaction limits the application of streptavidin as a reversible affinity matrix for purification of biotinylated biomolecules. To address this concern, a series of single, double, and triple streptavidin muteins with different affinities to biotin were designed. The strategy involves mutating one to three strategically positioned residues (Ser-45, Thr-90, and Asp-128) that interact with biotin and other framework structure-maintaining residues of streptavidin. The muteins were produced in soluble forms via secretion from Bacillus subtilis. The impact of individual residues on the overall structure of streptavidin is reflected by the formation of monomeric streptavidin to different extents. Of the three targeted residues, Asp-128 has the most dramatic effect (Asp-128 > Thr-90 > Ser-45). Conversion of all three targeted residues to alanine results in a soluble biotin binding mutein that exists 100% in the monomeric state. Both wild-type and mutated (monomeric and tetrameric) streptavidin proteins were purified, and their kinetic parameters (on- and off-rates) were determined using a BIAcore biosensor with biotin-conjugated bovine serum albumin immobilized to the sensor chip. This series of muteins shows a wide spectrum of affinity toward biotin (K(d) from 10(-6) to 10(-11) m). Some of them have the potential to serve as reversible biotin binding agents.

Radiofrequency ablation for unresectable hepatic tumors

BACKGROUND

Radiofrequency ablation (RFA) is a relatively new treatment for unresectable hepatic tumors. The purpose of this analysis was to examine the frequency of complications and local recurrence associated with RFA.

METHODS

Patients who underwent RFA of hepatic tumors with curative intent were included in this study. At laparotomy, RFA was performed using intraoperative ultrasound guidance. Computed tomography scans were obtained in the immediate postoperative period and every 3 to 6 months thereafter.

RESULTS

Forty patients underwent RFA for 122 hepatic tumors. Thirty-one patients had metastatic lesions from colorectal cancer; 9 had other liver tumors. Complications occurred in 8 patients. With 9.5 months median follow-up, 6 patients had local recurrence of their ablated tumors.

CONCLUSIONS

Our initial experience shows that RFA can effectively eradicate unresectable hepatic tumors. The rate and severity of complications appear acceptable. However, further study is necessary to assess long-term recurrence rates and effect on overall survival.

Utility of intraoperative frozen section analysis of sentinel lymph nodes in breast cancer

BACKGROUND

Intraoperative frozen section pathologic analysis of sentinel lymph node (SLN) may guide immediate (single-stage) completion axillary dissection for patients with nodal metastases.

METHODS

The results of 203 consecutive patients undergoing SLN biopsy who had intraoperative pathology consultation between January 1998 and September 2000 were reviewed. SLN were analyzed by standard frozen section procedures. Final pathologic analysis included hematoxylin and eosin (H&E) staining of serial sections at 2-mm intervals.

RESULTS

Frozen section analysis correctly identified a positive or negative result in 185 of 203 cases (overall accuracy 91%). In 17 of 53 cases, the SLNs were negative for tumor by frozen section, but positive on permanent section analysis (sensitivity 68%). The mean size of the nodal metastases was 6.2 mm and 1.5 mm in patients found to have true positive and false negative results, respectively (P <0.003). A single false positive SLN is reported.

CONCLUSIONS

Two thirds of the patients were spared the need for reoperative axillary lymphadenectomy.

The use of cytokeratin staining in sentinel lymph node biopsy for breast cancer

BACKGROUND

Controversy exists regarding the routine use of cytokeratin immunohistochemistry (IHC) in the histopathologic examination of breast cancer sentinel lymph nodes (SLN) because the clinical significance of micrometastases detected by IHC is unclear. This analysis was performed to determine the frequency of IHC-detected micrometastases.

METHODS

All patients underwent SLN biopsy, followed by completion axillary dissection. This analysis included patients who had SLN evaluated by IHC. SLN were examined by hematoxylin and eosin (H&E) stain at 2-mm intervals, with IHC in 2 sections. The axillary dissection specimen was evaluated by routine H&E staining.

RESULTS

IHC was performed in SLNs from 973 patients. Of the 869 patients with negative nodes by H&E, 58 (6.7%) were "upstaged" by IHC. In 6 of 58 patients (10.3%) who had IHC-only positive SLN, nodal metastases were found in the axillary dissection specimen.

CONCLUSIONS

IHC resulted in upstaging of 6.7% of patients who had negative SLN on H&E staining. These patients had a 10.3% risk of residual axillary nodal metastases. However, the clinical significance of IHC-only positive SLN requires further study.

Reliable lymphatic drainage to axillary sentinel lymph nodes regardless of tumor location within the breast

BACKGROUND

This analysis was performed in order to determine whether primary tumor location in breast cancer affects the axillary sentinel lymph node (SLN) identification (ID) rate, the false negative (FN) rate, incidence of axillary nodal metastases, or the number of SLN identified.

METHODS

In this prospective multi-institutional study, SLN biopsy was performed on clinical stage T1-2, N0 breast cancer patients using blue dye alone or in combination with radioactive colloid, followed by completion axillary LN dissection.

RESULTS

Central tumor location was associated with an improved FN rate, which may be related to reliable drainage from the subareolar lymphatic plexus. Tumor location did not significantly affect the SLN ID rate or the mean number of SLN identified. Medial tumor location was associated with a decreased rate of axillary nodal metastasis.

CONCLUSIONS

Breast cancers drain reliably to the axillary lymph nodes regardless of tumor location within the breast.

Defining the optimal surgeon experience for breast cancer sentinel lymph node biopsy: a model for implementation of new surgical techniques

OBJECTIVE

To determine the optimal experience required to minimize the false-negative rate of sentinel lymph node (SLN) biopsy for breast cancer.

SUMMARY BACKGROUND DATA

Before abandoning routine axillary dissection in favor of SLN biopsy for breast cancer, each surgeon and institution must document acceptable SLN identification and false-negative rates. Although some studies have examined the impact of individual surgeon experience on the SLN identification rate, minimal data exist to determine the optimal experience required to minimize the more crucial false-negative rate.

METHODS

Analysis was performed of a large prospective multiinstitutional study involving 226 surgeons. SLN biopsy was performed using blue dye, radioactive colloid, or both. SLN biopsy was performed with completion axillary LN dissection in all patients. The impact of surgeon experience on the SLN identification and false-negative rates was examined. Logistic regression analysis was performed to evaluate independent factors in addition to surgeon experience associated with these outcomes.

RESULTS

A total of 2,148 patients were enrolled in the study. Improvement in the SLN identification and false-negative rates was found after 20 cases had been performed. Multivariate analysis revealed that patient age, nonpalpable tumors, and injection of blue dye alone for SLN biopsy were independently associated with decreased SLN identification rates, whereas upper outer quadrant tumor location was the only factor associated with an increased false-negative rate.

CONCLUSIONS

Surgeons should perform at least 20 SLN cases with acceptable results before abandoning routine axillary dissection. This study provides a model for surgeon training and experience that may be applicable to the implementation of other new surgical technologies.

Roles of glucitol in the GutR-mediated transcription activation process in Bacillus subtilis: glucitol induces GutR to change its conformation and to bind ATP

GutR is a 95-kDa glucitol-dependent transcription activator that mediates the expression of the Bacillus subtilis glucitol operon. Glucitol allows GutR to bind tightly to its binding site located upstream of the gut promoter. In this study, a second functional role of glucitol is identified. Glucitol induces GutR to change its conformation and triggers GutR to bind ATP efficiently. After sequential binding of glucitol and ATP to GutR, GutR adopts a new conformation by forming a compact structure that is resistant to trypsin digestion. Under this condition, the ATP.glucitiol.GutR complex can dissociate slowly from the gutR-binding site (t(12) = 274 min). Interestingly, if ATP in the ATP.glucitiol.GutR complex is replaced by ADP, GutR adopts another conformation and can dissociate from the gutR-binding site even faster (t(12) = 82 min). In all these GutR-DNA binding studies in the presence of different ligands (glucitol, ATP, or ADP), only the off-rate is affected. The vital role of ATP in the GutR-mediated transcription activation process is reflected by the poor transcription from the gut promoter with GutR(D285A) which has a mutation in the motif B of the putative ATP-binding site. A working model for this transcription activation process is presented.