Prevalence, clonal diversity, and antimicrobial resistance of hypervirulent Klebsiella pneumoniae and Klebsiella variicola clinical isolates in northern Japan

OBJECTIVES

Hypervirulent Klebsiella pneumoniae (hvKp) and Klebsiella variicola (hvKv) cause hospital/community-acquired infections, often associated with antimicrobial resistance (AMR). This study aimed to investigate the molecular epidemiology of hvKp and hvKv in northern Japan.

METHODS

A total of 500 K. pneumoniae and 421 K. variicola clinical isolates collected from August to December 2021 were studied. Prevalence of virulence factor-encoding genes, wzi sequence and associated K/KL type, sequence type (ST), and beta-lactamases and their types were characterized.

RESULTS

Any virulence gene (rmpA, rmpA2, peg-344, iucA, iutA, and iroB) and/or magA was detected in 25% (n = 125) of K. pneumoniae and 1% (n = 5) of K. variicola. Among these hvKp/hvKv, 22 wzi types (18 and 4 types, respectively) and 24 STs (20 and 4 STs, respectively) were identified. Sequence types of hvKp were classified into some clonal groups (CGs), among which CG35, including six STs, was the most common (n = 59; 47%), followed by CG23, and CG65. ST268 (CG35) associated with wzi95-K20 or wzi720 was the dominant lineage (n = 43, 34%), while K1:ST23/ST249 and K2:ST65/ST86 accounted for 26% and 13% of hvKp, respectively. Extended-spectrum beta-lactamase (ESBL) genes (blaCTX-M-2, blaCTX-M-3, blaCTX-M-15, and blaCTX-M-27) were detected in only ST23 and CG35 (ST268 and ST412) hvKp. No isolate was resistant to carbapenems, without detection of the ESBL gene in K. variicola. Phylogenetically, wzi was differentiated into two main clusters of K. pneumoniae and K. variicola. A major clonal group CG347 was identified in K. variicola.

CONCLUSION

Clonal structures were revealed for hvKp and hvKv clinical isolates with their AMR status in northern Japan.

Raster plots machine learning to predict the seizure liability of drugs and to identify drugs

In vitro microelectrode array (MEA) assessment using human induced pluripotent stem cell (iPSC)-derived neurons holds promise as a method of seizure and toxicity evaluation. However, there are still issues surrounding the analysis methods used to predict seizure and toxicity liability as well as drug mechanisms of action. In the present study, we developed an artificial intelligence (AI) capable of predicting the seizure liability of drugs and identifying drugs using deep learning based on raster plots of neural network activity. The seizure liability prediction AI had a prediction accuracy of 98.4% for the drugs used to train it, classifying them correctly based on their responses as either seizure-causing compounds or seizure-free compounds. The AI also made concentration-dependent judgments of the seizure liability of drugs that it was not trained on. In addition, the drug identification AI implemented using the leave-one-sample-out scheme could distinguish among 13 seizure-causing compounds as well as seizure-free compound responses, with a mean accuracy of 99.9 ± 0.1% for all drugs. These AI prediction models are able to identify seizure liability concentration-dependence, rank the level of seizure liability based on the seizure liability probability, and identify the mechanism of the action of compounds. This holds promise for the future of in vitro MEA assessment as a powerful, high-accuracy new seizure liability prediction method.

Analysis of signal components < 500 Hz in brain organoids coupled to microelectrode arrays: A reliable test-bed for preclinical seizure liability assessment of drugs and screening of antiepileptic drugs

Brain organoids with three-dimensional structure and tissue-like function are highly demanded for brain disease research and drug evaluation. However, to our knowledge, methods for measuring and analyzing brain organoid function have not been developed yet. This study focused on the frequency components of an obtained waveform below 500 Hz using planner microelectrode array (MEA) and evaluated the response to the convulsants pentylenetetrazol (PTZ) and strychnine as well as the antiepileptic drugs (AEDs) perampanel and phenytoin. Sudden and persistent seizure-like firing was observed with PTZ administration, displaying a concentration-dependent periodic activity with the frequency component enhanced even in one oscillation characteristic. On the other hand, in the administration of AEDs, the frequency of oscillation decreased in a concentration-dependent manner and the intensity of the frequency component in one oscillation also decreased. Interestingly, at low doses of phenytoin, a group of synchronized bursts was formed, which was different from the response to the perampanel. Frequency components contained information on cerebral organoid function, and MEA was proven useful in predicting the seizure liability of drugs and evaluating the effect of AEDs with a different mechanism of action. In addition, frequency component analysis of brain organoids using MEA is an important analysis method to perform in vitro to in vivo extrapolation in the future, which will help explore the function of the organoid itself, study human brain developments, and treat various brain diseases.

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Frequency analysis <500 Hz was performed in brain organoids coupled to planner microelectrode arrays (MEA).

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Concentration-dependent changes in frequency components were detected in responses to convulsants and antiepileptic drugs (AEDs).

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Analysis of signal components <500 Hz in brain organoids is a useful method for preclinical seizure liability assessment of drugs and screening of antiepileptic drugs.

HIGH BACKGROUND AREA FOR RADIATION EDUCATION

This paper describes our trial experience of the use of high radiation area for radiation education. We used environmental samples collected from the high radiation area in Fukushima prefecture and India, for the practice of radiation measurement and health risk assessment in Nagasaki University Medical School. We also carried out the field monitoring seminar for students in the existing exposure areas in Tottori prefecture and the Yamakiya observatory in Fukushima. Although the evaluation of educational effectiveness is still underway, both types of education appeared attractive for the students mostly due to the exposure from natural environment in our real life which was not achieved by using an artificial radiation source in a classroom.

Abstract P5-18-05: Clinicopathological characteristics and prognosis of young patients with ductal carcinoma in situ

Background: The peak age at diagnosis of breast cancer differs between patients in Asian countries (40 - 50 years), and those in Western countries (60 - 70 years). With the increasing use of screening mammography, the incidence of ductal carcinoma in situ (DCIS) has increased significantly in younger Asian women. Nevertheless, our knowledge of the clinicopathological features and prognosis in young patients with DCIS is relatively limited. We aimed to compare the clinicopathological features of younger patients with that of older patients with DCIS and to evaluate their prognostic factors.Methods: A total of 1445 women were diagnosed with DCIS between the years 2005 and 2015. Patients with the past history of breast cancer and managed without surgery were excluded. The young age group included patients &lt;50 years of age, whereas the old age group included patients ≥50 years of age at diagnosis. We compared the clinicopathological characteristics [tumor size, surgery type, estrogen receptor (ER) and progesterone receptor (PgR) status, HER2 status, nuclear grade, margin status, radiotherapy, endocrine therapy, family history of breast cancer, and screening presentation or presentation with symptoms] and prognosis [disease-free survival (DFS), and overall survival (OS)] between the groups. DFS included the following events: contralateral breast cancer, loco-regional, and distant recurrences. DFS and OS were estimated using the Kaplan–Maier method. The risk factors associated with events were estimated using the log-rank test for univariate analysis. P values &lt; 0.05 were considered statistically significant.Result: Among the 1445 patients diagnosed with DCIS, 1281 were included in this study. The median age at diagnosis was 47 years (range, 22-87 years). The median follow-up time was 72 months (range, 1-162 months). ER and/or PgR status was positive in 1133 patients (88%). HER2 status was positive in 289 patients (23%). Premenopausal status was noted in 867 patients (68%). The median tumor size was 3.0 cm. Of 1281, 202 (18%) patients received endocrine therapy, 846 (66%) received breast conserving surgery, and 724 (86%) received radiation therapy. There were 765 patients (60%) in the young group. Significantly more patients in the young group had low nuclear grades, were ER and/or PgR positive, were HER2 receptor negative, underwent mastectomy, presented with symptoms, and had close/positive margins. Fifty-eight (4.5%) events occurred: 41 (3.2%) contralateral breast cancers, 19 (1.5%) loco-regional recurrences, and one (0.1%) distant metastasis. No death due to breast cancer was reported. On multivariate analysis, the young group (hazard ratio: 2.24, 95% CI: 1.01 - 4.95, P = 0.04), and presentation with clinical symptoms (hazard ratio: 2.09, 95% CI: 1.07-4.10, P = 0.03) significantly correlated with worse DFS. OS was not significantly different between the groups.Conclusion: This was the largest study with young patients with DCIS in the Asian population. We found that age at diagnosis was a significant independent factor associated with DFS. While genetic background also requires consideration, women with DCIS at &lt;50 year of age may require intensive surveillance. This result requires confirmation with longer follow-up.

Citation Format: Seki A, Matsuda N, Kajiura Y, Kobayashi D, Hayashi N, Tsunoda H, Suzuki K, Yoshida A, Takei J, Yamauchi H. Clinicopathological characteristics and prognosis of young patients with ductal carcinoma in situ [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-18-05.

A Novel Association between the 27-bp Deletion and 538G>A Mutation in the ABCC11 Gene

A single nucleotide polymorphism in the ABCC11 gene, 538G>A (rs17822931), is known to determine human ear wax type. The G/G and G/A genotypes correspond to the wet type, while the A/A genotype corresponds to the dry type. Another earwax determinant, a 27-bp deletion (Δ27) downstream from the rs17822931 site, is a rare variant that leads to the dry phenotype. In a previous report, we found an individual with the G allele who unexpectedly showed the dry type of earwax, leading to the identification of Δ27. We also demonstrated that the Δ27 allele was present in individuals of Japanese, Thai, native North American, Andean, and Bolivian ancestry but absent in those of European and African ancestry. Here, we assessed the Δ27 allele frequency among Japanese and Ukrainian individuals and identified a novel association between the Δ27 and 538G>A mutations. The Δ27 allele frequency was 0.002 (3/1,520; one individual is heterozygous, and another is homozygous) among Japanese individuals and 0 (0/794) among Ukrainians. We also found a previously unreported homozygous genotype for both the Δ27 and A alleles. Our findings suggest that the Δ27 deletion may have occurred in an ABCC11 gene with the 538G>A mutation.

Toxicological evaluation of convulsant and anticonvulsant drugs in human induced pluripotent stem cell-derived cortical neuronal networks using an MEA system

Functional evaluation assays using human induced pluripotent stem cell (hiPSC)-derived neurons can predict the convulsion toxicity of new drugs and the neurological effects of antiepileptic drugs. However, differences in responsiveness depending on convulsant type and antiepileptic drugs, and an evaluation index capable of comparing in vitro responses with in vivo responses are not well known. We observed the difference in synchronized burst patterns in the epileptiform activities induced by pentylentetrazole (PTZ) and 4-aminopryridine (4-AP) with different action mechanisms using multi-electrode arrays (MEAs); we also observed that 100 µM of the antiepileptic drug phenytoin suppressed epileptiform activities induced by PTZ, but increased those induced by 4-AP. To compare in vitro results with in vivo convulsive responses, frequency analysis of below 250 Hz, excluding the spike component, was performed. The in vivo convulsive firing enhancement of the high γ wave and β wave component were observed remarkably in in vitro hiPSC-derived neurons with astrocytes in co-culture. MEA measurement of hiPSC-derived neurons in co-culture with astrocytes and our analysis methods, including frequency analysis, appear effective for predicting convulsion toxicity, side effects, and their mechanism of action as well as the comparison of convulsions induced in vivo.

Detection of synchronized burst firing in cultured human induced pluripotent stem cell-derived neurons using a 4-step method

Human induced pluripotent stem cell-derived neurons are promising for use in toxicity evaluations in nonclinical studies. The multi-electrode array (MEA) assay is used in such evaluation systems because it can measure the electrophysiological function of a neural network noninvasively and with high throughput. Synchronized burst firing (SBF) is the main analytic parameter of pharmacological effects in MEA data, but an accurate method for detecting SBFs has not been established. In this study, we present a 4-step method that accurately detects a target SBF confirmed by the researcher's interpretation of a raster plot. This method calculates one set parameter per step, in the following order: the inter-spike interval (ISI), the number of spikes in an SBF, the inter-SBF interval, and the number of spikes in an SBF again. We found that the 4-step method is advantageous over the conventional method because it determines the preferable duration of an SBF, accurately distinguishes continuous SBFs, detects weak SBFs, and avoids false detection of SBFs. We found also that pharmacological evaluations involving SBF analysis may differ depending on whether the 4-step or conventional threshold method is used. This 4-step method may contribute to improving the accuracy of drug toxicity and efficacy evaluations using human induced pluripotent stem cell-derived neurons.

Abstract P1-16-04: Somatic mutations, clinicopathologic characteristics, and survival in patients with untreated breast cancer with bone-only and non-bone sites of first metastasis

Background: Bone is the most common site of metastasis of breast cancer, and bone metastasis is associated with a high rate of skeletal-related events, all of which contribute to decreased quality of life and poor outcomes. Biological mechanisms of metastasis to bone may be unique, and identification of distinct signaling pathways and somatic mutations may provide biological insight into or rational targets for treatment of and prevention of bone metastasis. The aims of this study were to compare and contrast somatic mutations, clinicopathologic characteristics, and survival in breast cancer patients with bone only versus non-bone as first metastatic site.

Methods: Tumor samples were collected from 389 patients who had metastasis and untreated primary breast cancer. In each sample, 46 or 50 cancer-related genes were selectively amplified and analyzed for mutations by AmpliSeq Ion Torrent next-generation sequencing. We used Fisher's exact test to identify somatic mutations associated with bone-only first metastasis and logistic regression models to identify differences in clinicopathologic characteristics, survival, and somatic mutations between patients with bone-only first metastasis and patients with first metastasis in non-bone sites only (“other-only first metastasis”).

Results: Among the 389 patients, the first metastasis was located in bone only in 72 patients (18.5%), non-bone sites only in 223 patients (57.3%), and both in 94 patients (24.2%). Of the cancer-related genes analyzed, the most commonly mutated were TP53 (N=103), PIK3CA (N=79), AKT (N=13), and PTEN (N=2). Compared to patients with other-only first metastasis, patients with bone-only first metastasis had higher rates of hormone-receptor-positive disease, non-triple-negative subtype, and low nuclear grade (grade 1 or 2) (all 3 comparisons, p&lt;0.001); had a lower ratio of cases of invasive ductal carcinoma to cases of invasive lobular carcinoma (p=0.002); and tended to have a higher 5-year overall survival (OS) rate (78.2% [95% confidence interval (CI), 68.6%-89.0%] vs 55.0% [95% CI, 48.1%-62.9%]; p=0.051). However, in the subgroup of patients with TP53 mutation and in the subgroup of patients with PIK3CA mutation, OS did not differ between patients with bone-only and other-only first metastasis (p=0.49 and p=0.68; respectively). In univariate analysis, the rate of TP53 mutation tended to be lower in patients with bone-only first metastasis than in those with other-only first metastasis (15.3% vs 29.1%; p=0.051). In multivariate analysis, TP53 mutation was not significantly associated with site of first metastasis (p=0.54) but was significantly associated with hormone-receptor-negative disease (p&lt;0.001).

Conclusions: We did not find associations between somatic mutations and bone-only first metastasis in patients with untreated breast cancer. Patients with bone-only first metastasis have longer OS than patients with other-only first metastasis. More comprehensive molecular analysis may be needed to further understand the factors associated with bone-only metastatic disease in breast cancer.

Citation Format: Kono M, Fujii T, Matsuda N, Harano K, Chen H, Wathoo C, Aron JY, Tripathy D, Meric-Bernstam F, Ueno NT. Somatic mutations, clinicopathologic characteristics, and survival in patients with untreated breast cancer with bone-only and non-bone sites of first metastasis [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-16-04.

Induction of long-term potentiation and depression phenomena in human induced pluripotent stem cell-derived cortical neurons

Plasticity such as long-term potentiation (LTP) and long-term potentiation depression (LTD) in neuronal networks has been analyzed using in vitro and in vivo techniques in simple animals to understand learning, memory, and development in brain function. Human induced pluripotent stem cell (hiPSC)-derived neurons may be effectively used for understanding the plasticity mechanism in human neuronal networks, thereby elucidating disease mechanisms and drug discoveries. In this study, we attempted the induction of LTP and LTD phenomena in a cultured hiPSC-derived cerebral cortical neuronal network using multi-electrode array (MEA) systems. High-frequency stimulation (HFS) produced a potentiated and depressed transmission in a neuronal circuit for 1 h in the evoked responses by test stimulus. The cross-correlation of responses revealed that spike patterns with specific timing were generated during LTP induction and disappeared during LTD induction and that the hiPSC-derived cortical neuronal network has the potential to repeatedly express the spike pattern with a precise timing change within 0.5 ms. We also detected the phenomenon for late-phase LTP (L-LTP) like plasticity and the effects for synchronized burst firing (SBF) in spontaneous firings by HFS. In conclusion, we detected the LTP and LTD phenomena in a hiPSC-derived neuronal network as the change of spike pattern. The studies of plasticity using hiPSC-derived neurons and a MEA system may be beneficial for clarifying the functions of human neuronal circuits and for applying to drug screening.

The availability of perifascial areolar tissue graft for deep cutaneous ulcer coverage

Soft tissue defects or skin ulcers associated with tendon or bone exposure located distally on the extremities are always difficult to treat. The introduction of the vacuum-assisted closure (VAC) and dermal templates has led to major changes in ulcer treatment strategies. However, it is necessary to find an alternative method to treat these defects when VAC is not available. Perifascial areolar tissue (PAT) is the loose connective tissue on the deep fascia that could be a candidate for repairing soft tissue defects or skin ulcers. Grafting PAT on the exposed bone or tendon, including a wide coverage of well-vascularized tissue surrounding the granulation tissue, can prepare the wound to be subsequently closed by a skin graft. In this study, the PAT was used in various situations and its optimal usage and outcomes were evaluated. A total of 13 PAT grafts were performed and were especially useful for covering narrow ulcers with narrow tendon exposure and filling fistula areas. In comparison to other cases, covering the exposed cortical bone ulcers seemed to be more difficult to perform. However, an option for these ulcers could be the exposure of bone marrow and usage of intraosseous blood flow. It was also possible for the simultaneous engraftment of PAT and skin in narrow areas and could be an alternative in cases of small concave ulcers or fistulae. The PAT graft is a simple and minimally invasive procedure that can be a good alternative when VAC is not available.

The role performance of public health nurses as clinical instructors in Japan

AIM

To investigate the factors associated with the role performance of public health nurses as clinical instructors in Japan.

BACKGROUND

Newly graduated public health nurses in Japan have competencies that are below the minimum requirements of the Ministry of Health, Labour and Welfare because of their limited clinical experience in undergraduate clinical education. Public health nurses play crucial roles in the clinical practicum and their role performance as clinical instructors is a key to successful learning outcomes.

METHODS

This study targeted public health nurses in governmental public health centres and those who had gained experience as an undergraduate clinical instructor for nursing students. A self-administered questionnaire was distributed to a national sample of 1467 public health nurses. Data were collected from July 2011 to September 2011.

RESULTS

In total, 722 of 1467 questionnaires were completed (nurse age 22-64 years). Of the participants, almost half (49%) strongly disagreed (3%) or disagreed (46%) that they had confidence in their role as a clinical instructor, and preparation programmes for clinical instructors had been attended by just 262 (36.3%). Years of experience as public health nurses, previous attendance of preparation programmes, viewing their role positively, professional identity and professional competency were significantly associated with performance. Logistic regression analysis revealed that nurses with higher role performance scores had higher self-confidence, greater interests in their role and higher professional identity.

CONCLUSIONS

The self-confidence and interests of public health nurses in their role as clinical instructors as well as their professional identity were found to be significant predictors of their role performance as clinical instructors.

IMPLICATIONS FOR NURSING PRACTICE AND EDUCATION

The factors identified in our investigation can be used to predict effective clinical instructors and to develop preparation programmes to enhance their confidence and interests and potentially increase their role satisfaction.

Abstract P5-16-04: Predictive biomarkers for invasion on final pathology in patients with preoperative diagnosis of ductal carcinoma in situ of the breast by needle biopsy

Background

Predictors of synchronous invasive breast cancer in patients diagnosed with only ductal carcinoma in situ (DCIS) in pre-operative needle biopsies have not been well-defined. Establishing such predictors of invasion has potential to significantly alter management by identifying those patients for whom surgery may be avoidable en lieu of conservative management. This study aims to identify clinicopathologic factors from pre-operative needle biopsies that are predictive of invasive cancer on subsequent surgical excision.

Methods

The study population consisted of 69 breasts from 67 patients initially diagnosed with only DCIS on needle biopsy (core needle or mammotome) at St. Luke's International Hospital, Japan from 2006 until 2008. Parameters analyzed included presenting clinical features, DCIS nuclear grade and morphologic pattern, and immunohistochemical expression of estrogen receptor (ER), progesterone receptor (PR), epidermal growth factor receptor-2 (HER2), Ki-67 antigen, p16, p53 and cyclooxygenase-2 (COX2) in biopsy specimens. These immunohistochemical markers were previously identified to foretell invasive carcinoma subsequent to DCIS (Kerlikowske, JNCI 2010). Associations between clinical, pathological, and immunohistochemical findings in initial biopsy specimens and the presence of invasive cancer on subsequent excision were analyzed for significance using univariate and multivariate analysis.

Results

Of 69 breasts with only DCIS on initial needle biopsy, subsequent surgical excision revealed pure DCIS in 46 (66.7%), microinvasive carcinoma in 4 (5.8%), and invasive carcinoma in 19 (27.5%) cases. Sentinel node biopsy was performed in 57 (82.6%) of 69 cases, and 53 (93.0%) of these showed no evidence of lymph node metastases. All 4 cases with lymph node metastases revealed invasive carcinoma in surgical excisions. By univariate analysis, pre-operative factors significantly associated with invasion on surgical excision included detection of a lump by palpation (p&lt;0.05), sampling by core needle biopsy rather than mammotome (p&lt;0.01), p53 positivity (p&lt;0.01), and lack of ER expression (p&lt;0.05) in needle biopsy samples. Combined absence of p16 and COX2 with low Ki-67 expression in needle biopsies was associated with pure DCIS (and absence of invasive cancer) in surgical excisions (p&lt;0.05). Multivariate analysis using all five significant univariate variables revealed two independent pre-operative predictors of invasive cancer on final pathology, namely sampling by core needle biopsy (odds ratio 7.0; 95% CI 1.2-41.7; p&lt;0.05) and p53 positivity (odds ratio 7.1; 95% CI 1.1-44.9; p&lt;0.05).

Conclusion

If confirmed in a larger sample, predictive clinical and biomarker parameters can help identify those patients diagnosed with only DCIS in needle biopsy who are at high risk of harboring unsampled invasive cancer on final pathology.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-16-04.

Abstract P3-14-10: Conversion to node-negative after neoadjuvant chemotherapy is a surrogate prognostic marker in patients with hormone receptor-positive breast cancer

Background: While pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) improves patients’ survival with HER2-positive and triple-negative (TN) breast cancers, it has been reported not to be the same for patients with hormone receptor (HR)-positive breast cancer. However, it is not well known whether chemosensitivity presented by change in tumor stage or nodal status after NAC contributes to improve the prognosis with HR-positive breast cancer. The aim of this study was to evaluate the impact of change in tumor stage or nodal status after NAC on prognosis in patients with primary breast cancer.

Patients and Methods: We assessed retrospectively 599 consecutive patients with primary breast cancer (a median age of 49 years, ranging 26-79 years) who underwent surgical resection after NAC between 2001 and 2008. HR (ER and PR) statuses were determined by immunohistochemistory (IHC). HER2 status was determined by IHC and/or fluorescent in situ hybridization assays. ER-positive and PR-positive patients were 426 (71.1%) and 353 patients (58.9%), respectively. HER2 status was positive in 130 patients (21.7%). HR-positive subtype was defined as ER and/or PR-positive and HER2 negative. We compared the patients with respect to disease-free survival (DFS) and overall survival (OS) based on change in tumor stage and nodal status after NAC. pCR was defined as no residual invasive tumor and ypN0.

Results: After NAC, 84 (14.0%) patients had pCR. Two hundred ninety one (48.6%) decreased tumor stage and 308 (51.4%) did not decrease tumor stage. Regarding nodal status, 190 (31.7%) had cN0 and 409 (68.3%) had cN+ before NAC, and 286 had ypN0 (47.7%) and 313 had ypN+ (52.2%). For patients with TN breast cancer, patients with pCR had excellent prognosis compared to those with residual tumor in either the breast or lymph node (non-pCR) (DFS, p&lt;0.01, and OS, p = 0.035, respectively). Among the non-pCR group, patients with ypN0 also have longer DFS and OS than patients with ypN+ (p&lt;0.01, and p = 0.031, respectively). However, for ypN0 patients with TN breast cancer, patients with residual primary tumor had significantly shorter DFS and OS than patients with ypT0. For HR-positive breast cancer patients, there was a trend that patients with pCR had better DFS than patients with non-pCR (p = 0.069). In terms of OS, there was no significant difference between pCR and non-pCR (p = 0.285). Patients with ypN0 had significantly longer DFS and OS than those with ypN+ regardless of residual tumor stage (p&lt; 0.001 and p = 0.01, respectively). Change in tumor stage itself did not contribute to improve patients’ survival.

Conclusions: Our results revealed that HR-positive breast cancer patients with conversion to lymph nodes metastasis after NAC have a good prognosis even if they have residual tumor in the breast, while TN breast cancer patients require pCR to have a good prognosis. It indicated that conversion to node-negative after neoadjuvant chemotherapy might be a surrogate prognostic marker in patients with HR-positive breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-10.

Evaluation of matrix-assisted laser desorption ionization-time of flight mass spectrometry for species identification of Acinetobacter strains isolated from blood cultures

The clinical relevance of Acinetobacter species, other than A. baumannii, as human pathogens has not been sufficiently assessed owing to the insufficiency of simple phenotypic clinical diagnostic laboratory tests. Infections caused by these organisms have different impacts on clinical outcome and require different treatment and management approaches. It is therefore important to correctly identify Acinetobacter species. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been introduced to identify a wide range of microorganisms in clinical laboratories, but only a few studies have examined its utility for identifying Acinetobacter species, particularly those of the non-Acinetobacter baumannii complex. We therefore evaluated MALDI-TOF MS for identification of Acinetobacter species by comparing it with sequence analysis of rpoB using 123 isolates of Acinetobacter species from blood. Of the isolates examined, we identified 106/123 (86.2%) to species, and 16/123 (13.0%) could only be identified as acinetobacters. The identity of one isolate could not be established. Of the 106 species identified, 89/106 (84.0%) were confirmed by rpoB sequence analysis, and 17/106 (16.0%) were discordant. These data indicate correct identification of 89/123 (72.4%) isolates. Surprisingly, all blood culture isolates were identified as 13 species of Acinetobacter, and the incidence of Acinetobacter pittii was unexpectedly high (42/123; 34.1%) and exceeded that of A. baumannii (22/123; 17.9%). Although the present identification rate using MALDI-TOF MS is not acceptable for species-level identification of Acinetobacter, further expansion of the database should remedy this situation.

Cylinder syringe suction: a simple and efficient technique for the evacuation of subcutaneous hematoma

BACKGROUND

Subcutaneous hematoma is commonly caused by trauma or surgery. Proper treatment of the condition is needed to avoid severe complications. The present paper introduces a simple technique of hematoma evacuation, called cylinder syringe suction (CSS). Experiments were also performed to determine the detailed mechanism underlying its effectiveness.

METHODS

The CSS procedure was performed as follows. A cylindrical plastic cylinder syringe was used. Either a few stitches were removed or a very small incision was made on the site of the hematoma. The edge of the syringe was compressed to the skin, which was covered by a thin hydrocolloid dressing. Vacuum aspiration was enforced at the site of the wound or incision, and the hematoma was gradually aspirated.For the experiment, house rabbits were used. Hematoma evacuation was performed in 4 different ways, including needle aspiration alone (group 1), needle puncture followed by CSS (group 2), and creation of a small wound (5 mm) followed by needle aspiration (group 3) or CSS (group 4). The amount of evacuated hematoma and the suction pressure created by each of the 4 methods were compared.

RESULTS

Group 4 showed the highest suction pressure and the greatest evacuated amount of hematoma. High suction pressure was also obtained in group 1; however, the amount of evacuated hematoma was small as the other 2 groups.

CONCLUSION

The CSS technique becomes effective mainly by creating high suction pressure, and the opening of a small wound enables the viscous coagula to pass through the skin.

Role of macrophage colony-stimulating factor (M-CSF)-dependent macrophages in gastric ulcer healing in mice

We examined the role of macrophage colony-stimulating factor (M-CSF)-dependent macrophages in the healing of gastric ulcers in mice. Male M-CSF-deficient (op/op) and M-CSF-expressing heterozygote (+/?) mice were used. Gastric ulcers were induced by thermal cauterization under ether anesthesia, and healing was observed for 14 days after ulceration. The numbers of macrophages and microvessels in the gastric mucosa were determined immunohistochemically with anti-CD68 and anti-CD31 antibodies, respectively. Expression of tumor necrosis factor (TNF)-α, cyclooxygenase (COX)-2, and vascular endothelial growth factor (VEGF) mRNA was determined via real-time reverse transcription-polymerase chain reaction (RT-PCR), and the mucosal content of prostaglandin (PG) E(2) was determined via enzyme immunoassay on day 10 after ulceration. The healing of gastric ulcers was significantly delayed in op/op mice compared with +/? mice. Further, significantly fewer macrophages were observed in the normal gastric mucosa of op/op mice than in +/? mice. Ulcer induction caused a marked accumulation of macrophages around the ulcer base in +/? mice, but this response was attenuated in op/op mice. The mucosal PGE(2) content as well as the expression of COX-2, VEGF, and TNF-α mRNA were all upregulated in the ulcerated area of +/? mice but significantly suppressed in op/op mice. The degree of vascularization in the ulcerated area was significantly lower in op/op mice than in +/? mice. Taken together, these results suggest that M-CSF-dependent macrophages play an important role in the healing of gastric ulcers, and that this action may be associated with angiogenesis promoted by upregulation of COX-2/PGE(2) production.

Investigation of the presence of ghrelin in the central nervous system of the rat and mouse

Ghrelin and ghrelin receptor agonist have effects on central neurons in many locations, including the hypothalamus, caudal brain stem, and spinal cord. However, descriptions of the distributions of ghrelin-like immunoreactivity in the CNS in published work are inconsistent. We have used three well-characterized anti-ghrelin antibodies, an antibody to the unacylated form of ghrelin, and a ghrelin peptide assay in rats, mice, ghrelin knockout mice, and ghrelin receptor reporter mice to re-evaluate ghrelin presence in the rodent CNS. The stomach served as a positive control. All antibodies were effective in revealing gastric endocrine cells. However, no specific staining could be found in the brain or spinal cord. Concentrations of antibody 10 to 30 times those effective in the stomach bound to nerve cells in rat and mouse brain, but this binding was not reduced by absorbing concentrations of ghrelin peptide, or by use of ghrelin gene knockout mice. Concentrations of ghrelin-like peptide, detected by enzyme-linked immunosorbent assay in extracts of hypothalamus, were 1% of gastric concentrations. Ghrelin receptor-expressing neurons had no adjacent ghrelin immunoreactive terminals. It is concluded that there are insignificant amounts of authentic ghrelin in neurons in the mouse or rat CNS and that ghrelin receptor-expressing neurons do not receive synaptic inputs from ghrelin-immunoreactive nerve terminals in these species.

Molecular analysis of new isolates of Tomato leaf curl Philippines virus and an associated betasatellite occurring in the Philippines

Three new begomovirus isolates and one betasatellite were obtained from a tomato plant exhibiting leaf curl symptom in Laguna, the Philippines. Typical begomovirus DNA components representing the three isolates (PH01, PH02 and PH03) were cloned, and their full-length sequences were determined to be 2754 to 2746 nucleotides. The genome organizations of these isolates were similar to those of other Old World monopartite begomoviruses. The sequence data indicated that PH01 and PH02 were variants of strain B of the species Tomato leaf curl Philippines virus, while PH03 was a variant of strain A of the species Tomato leaf curl Philippines virus. These isolates were designated ToLCPV-B[PH:Lag1:06], ToLCPV-B[PH:Lag2:06], and ToLCPV-A[PH:Lag3:06], respectively. Phylogenetic analysis revealed that the present isolates form a separate monophyletic cluster with indigenous begomoviruses reported earlier in the Philippines. A betasatellite isolated from same sample belongs to the betasatellite species Tomato leaf curl Philippines betasatellite and designated Tomato leaf curl Philippines betasatellite-[Philippines:Laguna1:2006], ToLCPHB-[PH:Lag1:06]. When co-inoculated with this betasatellite, tomato leaf curl Philippines virus induced severe symptoms in N. benthamiana and Solanum lycopersicum plants. Using a PVX-mediated transient assay, we found that the C4 and C2 proteins of tomato leaf curl Philippines virus and the βC1 protein of ToLCPHB-[PH:Lag1:06] function as a suppressor of RNA silencing.

Cerebral oxygenation in the beach chair position before and during general anesthesia

AIM

Ischemic brain damage related to the beach chair position is a matter of concern. The current study was designed to evaluate whether the beach chair position before and during general anesthesia differentially induces changes in cerebral oxygenation as determined by near-infrared spectroscopy (NIRS) in surgical patients.

METHODS

We evaluated brain tissue oxygen index (TOI) values using the NIRS monitor NIRO-200TM in the beach chair position the day before and during general anesthesia. Thirty patients with normal preoperative TOI values undergoing shoulder surgery were enrolled. The initial TOI measurement in the supine position after 10 min rest or 10 min after tracheal intubation was followed by measurements after 5 min each in the 30-degree and subsequently 60-degree head-up tilt positions. During general anesthesia, patients were mechanically ventilated to obtain normocapnia under inhalation of 1.5% sevoflurane in 50% oxygen. Mean blood pressure (MAP) was measured non-invasively in the arm at heart level and was maintained above 60 mmHg with phenylephrine.

RESULTS

Preoperative TOI values and preoperative MAP were within the normal range in the study population. MAP decreased upon anesthesia but did not further change when the patient was placed in the 30- and 60-degree head-up tilt positions. Heart rate also decreased upon anesthesia. However, TOI values did not change with induction of general anesthesia or placement of the patients in the beach chair position.

CONCLUSION

Under general anesthesia, the beach chair position does not alter cerebral oxygenation in patients showing normal preoperative cerebral TOI values.

In Which Patients Can We Accurately Evaluate the Status of Axillary Lymph Node Metastases Using Sentinel Lymph Node Biopsy after Neoadjuvant Chemotherapy?

Background: Several studies have reported on the feasibility of sentinel lymph node (SLN) biopsy after neoadjuvant chemotherapy (NAC) in breast cancer patients. However, the accuracy has been variable depends on reports. We would like to determine in which patients we can accurately evaluate the status of axillary lymph node metastases using SLN biopsy after NAC in cytology-proved positive lymph node patients.Patients and Methods: Ninety-five cytology-proved node positive patients underwent SLN biopsy followed by axillary dissection between February 2007 and April 2009. All of those had clinical response in primary breast tumor detected by MRI after NAC.Results: SLN biopsy after NAC was successfully performed 81 out of 95 patients (85.3%). Among those 81 patients, lymph node metastases after NAC were identified by final pathology in 51 patients (63.0%). Eight of those 51 patients with lymph node metastases showed negative SLN biopsy. Therefore false negative rate was 15.7%. Patients who were diagnosed ER negative from the core needle specimen prior to NAC or had clinical CR by MRI did not showed any false negative by SLN biopsy. SLN were identified in 27 out of those 30 patients (90%). Final pathology after NAC revealed 7 patients with lymph node metastases and all of them had positive SLN. Twenty out of 27 (74.1%) patients revealed no evidence of metastases in both SLN and non-SLN.Discussion: After NAC, the false negative rate of SLN biopsies was high (15.7%) in cytology –proved lymph node-positive breast cancer patients. However, this study suggested that SLN biopsy after NAC may be performed accurately in patients who had ER negative tumor or CR by MRI, and that 20 out of 95 patients (21%) could possibly avoid axillary dissection after NAC. These results need to be confirmed by larger studies for the selected patients.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1036.

Localization of acyl ghrelin- and des-acyl ghrelin-immunoreactive cells in the rat stomach and their responses to intragastric pH

Acyl ghrelin has a 28-amino acid sequence with O-n-octanoyl acid modification at the serine 3 position, whereas des-acyl ghrelin has no octanoyl acid modification. Although these peptides exert different physiological functions, no previous studies have shown the different localization of acyl ghrelin and des-acyl ghrelin in the stomach. Here we have developed an antibody specific for des-acyl ghrelin that does not crossreact with acyl ghrelin. Both acyl ghrelin- and des-acyl ghrelin-immunoreactive cells were distributed in the oxyntic and antral mucosa of the rat stomach, with higher density in the antral mucosa than oxyntic mucosa. Immunofluorescence double staining showed that acyl ghrelin- and des-acyl ghrelin-positive reactions overlapped in closed-type round cells, whereas des-acyl ghrelin-positive reaction was found in open-type cells in which acyl ghrelin was negative. Acyl ghrelin-/des-acyl ghrelin-positive closed-type cells contain obestatin; on the other hand, des-acyl ghrelin-positive open-type cells contain somatostatin. We measured the release of acyl ghrelin and des-acyl ghrelin in vascularly perfused rat stomach by ELISA, and the effects of different intragastric pH levels on the release of each peptide were examined. The release of des-acyl ghrelin from the perfused stomach was greater at pH 2 than at pH 4; however, the release of acyl ghrelin was not affected by intragastric pH. The present study demonstrated the differential localization of acyl ghrelin and des-acyl ghrelin in the rat stomach and their different responses to the intragastric pH.

E-cadherin expression in the subepithelial nevus cells of the giant congenital nevocellular nevi (GCNN) correlates with their migration ability in vitro

BACKGROUND

Giant congenital nevocellular nevi (GCNN) are histologically characterized by the broad distribution of nevus cells in the epidermis and dermis.

OBJECTIVE

To characterize E-cadherin in GCNN and define its role in nevic cell migrations.

METHODS

Twenty-four cases were immunohistochemically examined and in five cases cells were isolated for primary culture for migration assays.

RESULTS

The nevus cells in the superficial region showed the immunoreactivity of E-cadherin in a membranous pattern, but those in the deep part of dermis had little immunoreactivity. Ultra-structural analysis of the superficial nevus cells revealed that E-cadherin immunodeposits in the fibrillar processes around the cell body in a spotted pattern. This distribution pattern is quite different from that in the adherens junction of skin squamous epithelial cells. Boyden chamber experiments were performed using primary cultures of intradermal nevus cells. EDTA pretreatment reduced cell migration to the E-cadherin positive side when the E-cadherin positive population was relatively large in the primary cultures.

CONCLUSIONS

These results indicate that E-cadherin in the nevus cells may affect nevus cell motility rather than intercellular attachment.

Rapid, severe repigmentation of congenital melanocytic naevi after curettage and dermabrasion: histological features

BACKGROUND

Curettage and dermabrasion are effective in treating giant congenital melanocytic naevi (GCMN). We report two patients with rapid, severe postoperative repigmentation. To the best of our knowledge this is the first report on the histological features of such patients.

OBJECTIVES

We wish to call attention to histological features that may cause rapid, severe repigmentation after curettage and dermabrasion of medium to giant CMN.

PATIENTS/METHODS

From 1998 to 2002, we treated 23 patients with medium to giant CMN with curettage and dermabrasion. Patients being treated ranged in age from 1 month to 19 years. Histological samples were taken from the centre of naevi in all patients during surgery. Histological types were 12 intradermal and 11 compound. Follow-up after curettage lasted at least 3 years.

RESULTS

Among our 23 patients only two showed repigmentation soon after surgery. Histological sections from these two patients indicated naevoid cells in the deep dermis along hair follicles or sebaceous glands. However, no such pigmented naevoid cells along hair follicles were observed in samples from patients successfully treated with curettage and dermabrasion with less repigmentation.

CONCLUSIONS

Although we saw only two cases of repigmentation soon after curettage and dermabrasion, we suspect a correlation between pigmented naevoid cells around hair follicles and repigmentation. If histological sections of skin biopsies show pigmented cells along hair follicles in the deep dermis, other treatments such as total skin resection followed by skin grafting or tissue expansion may be better choices than curettage or dermabrasion.

Radiation safety design for the J-PARC Project

The High-Intensity Proton Accelerator Project, named J-PARC, is in progress, with the aim of enabling studies on the latest basic science and the advancement of nuclear technology. In the project, a high-energy proton accelerator complex with the world's highest instantaneous intensity is under construction. In order to establish a reasonable shielding design, both simplified and detailed design methods were used in the shielding design of J-PARC. This paper reviews the present status of the radiation safety design study for J-PARC.

Radiation streaming experiment through a labyrinth of the 12 GeV proton accelerator facility at KEK(2)--TLD REM-counter method

The doses of radiation streaming through a labyrinth were measured using thermoluminescence dosemeters (TLDs) and neutron moderators for TLDs at the neutrino beam line of the 12 GeV proton accelerator facility of High Energy Accelerator Research Organization (KEK). The calculated doses using the Monte Carlo code, MCNPX basically agreed with the experimental results. However, unexpectedly, the calculated neutron doses were smaller than the measured ones along the upstream side of the labyrinth.

Aromatase is abundantly expressed by neonatal rat penis but downregulated in adulthood

Although synthesis of estrogen by male gonads has been well documented for over half a century, it is only recently that the role of estrogen in male reproductive events has gained appreciation. We recently reported abundant expression of estrogen receptor (ER)-alpha and -beta in different cell types of the rat penis, whose levels diminished with advancing age. The present study, which builds on data from the ER study, was designed to determine whether the penis is capable of generating its own local estrogen by examining evidence of the expression of aromatase, a microsomal enzymatic complex which irreversibly converts androgens to estrogens, using immunohistochemistry, Western blotting, in situ hybridization and real-time PCR analyses. Secondly, the effects of sex steroid hormones on penile aromatase were examined. Discrete aromatase immunoreactive cells were localized in primordial corpus cavernosum, corpus spongiosus and os penis, blood vessels and sensory corpuscle of glans penis. In situ hybridization signals corresponded with immunohistochemical findings. Western blot, enzyme immunoassay and real-time PCR analyses of rat penile samples revealed an age-dependent expression of aromatase and estrogen, with levels at week 1 almost resembling those of the ovary, but they decreased sharply by week 8, and decreased further by week 35. This expression pattern was strikingly similar to that of ER-alpha reported previously. Testosterone and diethylstilbesterol administered prenatally upregulate levels of aromatase mRNA and protein, and estrogen postnatally. Dihydrotestosterone upregulated aromatase mRNA and protein, but not estrogen. We conclude that estrogen acts via ER in a paracrine and/or autocrine manner to regulate penile events, particularly during development, and that estrogen synthesis is regulated by estrogen and androgens.