Molecular Type Research Articles

Artificial Intelligence Imaging for Predicting High-risk Molecular Markers of Gliomas.

Gliomas, the most prevalent primary malignant tumors of the central nervous system, present significant challenges in diagnosis and prognosis. The fifth edition of the World Health Organization Classification of Tumors of the Central Nervous System (WHO CNS5) published in 2021, has emphasized the role of high-risk molecular markers in gliomas. These markers are crucial for enhancing glioma grading and influencing survival and prognosis. Noninvasive prediction of these high-risk molecular markers is vital. Genetic testing after biopsy, the current standard for determining molecular type, is invasive and time-consuming. Magnetic resonance imaging (MRI) offers anon-invasive alternative, providing structural and functional insights into gliomas. Advanced MRI methods can potentially reflect the pathological characteristics associated with glioma molecular markers; however, they struggle to fully represent gliomas' high heterogeneity. Artificial intelligence (AI) imaging, capable of processing vast medical image datasets, can extract critical molecular information. AI imaging thus emerges as anoninvasive and efficient method for identifying high-risk molecular markers in gliomas, arecent focus of research. This review presents acomprehensive analysis of AI imaging's role in predicting glioma high-risk molecular markers, highlighting challenges and future directions.

In vitro characterization and molecular epidemiology of Cryptococcus spp. isolates from non-HIV patients in Guangdong, China.

The burden of cryptococcosis in mainland China is enormous. However, the in vitro characterization and molecular epidemiology in Guangdong, a key region with a high incidence of fungal infection in China, are not clear. From January 1, 2010, to March 31, 2019, clinical strains of Cryptococcus were collected from six medical centres in Guangdong. The clinical information and characteristics of the strains were analysed. Furthermore, molecular types were determined. A total of 84 strains were collected, mostly from male and young or middle-aged adult patients. Pulmonary and cerebral infections (82.1%) were most common. All strains were Cryptococcus neoformans, grew well at 37°C and had capsules around their cells. One melanin- and urea- and one melanin+ and urea- variants were found. Although most strains exhibited a low minimum inhibitory concentration (MIC) value for voriconazole (mean: 0.04 μg/mL) and posaconazole (mean: 0.12 μg/mL), the results for these isolates showed a high degree of variation in the MIC values of fluconazole and 5-fluorocytosine, and resistance was observed for 4 out of 6 drugs. A significant proportion of these strains had MIC values near the ECV values, particularly in the case of amphotericin B. The proportion of strains near the clinical breakpoints was as follows: fluconazole: 3.66%; voriconazole: 3.66%; itraconazole: 6.10%; posaconazole: 13.41%; amphotericin B: 84.15%; 5-fluorocytosine: 2.44%. These strains were highly homogeneous and were dominated by the Grubii variant (95.2%), VNI (94.0%), α mating (100%), and ST5 (89.3%) genotypes. Other rare types, including ST4, 31, 278, 7, 57 and 106, were also found. Phenotypically variant and non-wild-type strains were found in Guangdong, and a significant proportion of these strains had MIC values near the ECV values towards the 6 antifungal drugs, and resistance was observed for 4 out of 6 drugs. The molecular type was highly homogeneous but compositionally diverse, with rare types found. Enhanced surveillance of the aetiology and evolution and continuous monitoring of antifungal susceptibility are needed to provide references for decision-making in the health sector and optimization of disease prevention and control.

Morphology-based molecular classification of spinal cord ependymomas using deep neural networks.

Based on DNA-methylation, ependymomas growing in the spinal cord comprise two major molecular types termed spinal (SP-EPN) and myxopapillary ependymomas (MPE(-A/B)), which differ with respect to their clinical features and prognosis. Due to the existing discrepancy between histomorphogical diagnoses and classification using methylation data, we asked whether deep neural networks can predict the DNA methylation class of spinal cord ependymomas from hematoxylin and eosin stained whole-slide images. Using explainable AI, we further aimed to prospectively improve the consistency of histology-based diagnoses with DNA methylation profiling by identifying and quantifying distinct morphological patterns of these molecular ependymoma types. We assembled a case series of 139 molecularly characterized spinal cord ependymomas (nMPE = 84, nSP-EPN = 55). Self-supervised and weakly-supervised neural networks were used for classification. We employed attention analysis and supervised machine-learning methods for the discovery and quantification of morphological features and their correlation to the diagnoses of experienced neuropathologists. Our best performing model predicted the DNA methylation class with 98% test accuracy and used self-supervised learning to outperform pretrained encoder-networks (86% test accuracy). In contrast, the diagnoses of neuropathologists matched the DNA methylation class in only 83% of cases. Domain-adaptation techniques improved model generalization to an external validation cohort by up to 22%. Statistically significant morphological features were identified per molecular type and quantitatively correlated to human diagnoses. The approach was extended to recently defined subtypes of myxopapillary ependymomas (MPE-(A/B), 80% test accuracy). In summary, we demonstrated the accurate prediction of the DNA methylation class of spinal cord ependymomas (SP-EPN, MPE(-A/B)) using hematoxylin and eosin stained whole-slide images. Our approach may prospectively serve as a supplementary resource for integrated diagnostics and may even help to establish a standardized, high-quality level of histology-based diagnostics across institutions-in particular in low-income countries, where expensive DNA-methylation analyses may not be readily available.

Neuroendocrine expression markers in triple-negative, luminal-A, luminal-B and HER2neu breast cancer

Primary breast tumors with neuroendocrine (NE) differentiation are a heterogeneous tumor group with diversity of biological behavior, with poorly defined prevalence and prognosis. To evaluate the chromogranin, synaptophysin, CD56, INSM1 markers expression prevalence and the association between NE differentiation and tumor molecular type. Observational, cross-sectional study which included 110 breast tissue samples with primary invasive carcinoma. Immunohistochemistry was performed for chromogranin, synaptophysin, CD56 and INMS1 markers. NE differentiation was considered with 10-90% positive cells, and NE tumor with > 90% positive cells. 26.3% showed neuroendocrine differentiation. Out of these, 48.2% were luminal-A type, 24.1% luminal-B, 11.5% HER2neu, 17.2% triple-negative; 1.8% were NE tumors. Tumors were marker positive, and out of these to chromogranin in 24.5%, synaptophysin in 28.2%, CD56 in 2.7%, INSM1 in 16.4%. Synaptophysin was expressed in 17.3% luminal-A type, 6.4% luminal-B, 0.9% HER2neu, 3.6% triple-negative. NE differentiation showed association with synaptophysin expression (r = 0.586, p = 0.0001). The NE differentiation prevalence was 26.3% in primary invasive breast cancers, with luminal-A molecular type predominance.

Locoregional recurrences of breast cancer after reconstructive plastic and organ-preserving surgery

Objective. To analyze locoregional relapses (LRR) after reconstructive plastic and organ-preserving operations in breast cancer (BC)Materials and methods. A retrospective analysis of the results of the treatment of 303 patients with BC who underwent reconstructive plastic and organ-preserving operations in the period from 2014 to 2019 in the Oncological Department of General Oncology and Rehabilitation of Gomel Regional Clinical Oncological Dispensary was carried out. The median age was 44 years (25-70 years). Statistical data processing was carried out using the application software package “Statistica”, 10.0. To characterize the surveyed groups, a standard methodological approach based on the calculation of descriptive statistics data was used. In order to statistically assess the relationship between the frequency of relapses depending on the stage and the molecular biological type of neoplasm, the Spearman correlation coeffi cient was used. The accepted level of statistical signifi cance (p) was 0.05.Results. Locoregional relapses were recorded in 11 (3.6%) patients, of which local — in 8 (2.6%), regional — in 3 (1.0%). The minimum period of development of LRR was 15 months, the maximum was 74 months; the median period of occurrence of LRR was 47 months. Depending on the stage of breast cancer, relapses developed: at stage I — in 4 (3.7%) cases, II — 5 (3.5%), III — 2 (4.2%). Depending on the molecular biological subtype of the neoplasm, LRR were distributed as follows: with luminal A — 1 (1.3%) case, luminal In HER2-negative — 1 (0.9%), luminal In HER2-positive — 6 (9.7%), non-luminal HER2-positive 1 (6.3%), three times negative — 2 (5.6%). Discordance of the receptor status was detected in 8 (72.7%) patients with recurrent tumor, most often due to the loss or decrease in the number of progesterone receptors (PR). The level of tumor-infi ltrating lymphocytes (TILs) in primary neoplasm ranged from 4 to 12%, in recurrent tumors it remained low: 5-10%.Conclusion. Given the heterogeneity of BC, the risk of developing LRR depends on many factors. LRR developed in luminal HER2-positive cancer in 9.7% of cases (p 0.05), stage III breast cancer — 4.2% (p 0.05). One of the important predictive factors is the evaluation of TILs. We noted a low level of TILs in both primary and recurrent tumors. There is a high discordance in the receptor status — 72.7%, which is important to take into account when prescribing systemic therapy.

BRCA mutation status and pathological characterization of breast cancer in Zhoushan Islands, China.

To investigate BRCA1/2 gene mutations and their relationship with clinicopathological features in patients with breast cancer in Zhoushan Islands. High-throughput whole-exome gene sequencing was used to detect BRCA1/2 mutations in 776 breast cancer patients in Zhoushan Islands. The BRCA1/2 mutation rate of breast cancer patients in Zhoushan Islands was 4.38% (34/776). BRCA1 mutations were significantly correlated with age, molecular type, and family history of breast and ovarian cancers. BRCA2 mutations were most commonly found in invasive lobular carcinoma. Moreover, the BRCA2 mutation rate of cancers with molecular type luminal B (receptor protein-tyrosine kinase [HER2]-negative) was also relatively high. The rate of BRCA1/2 mutations in breast cancer patients from Zhoushan Islands is approximately 4.38%, and BRCA1 mutation is related to age, molecular type, and family history of breast and ovarian cancers.

Novel machine learning approach toward classification model of HIV-1 integrase inhibitors.

HIV-1 (human immunodeficiency virus-1) has been causing severe pandemics by attacking the immune system of its host. Left untreated, it can lead to AIDS (acquired immunodeficiency syndrome), where death is inevitable due to opportunistic diseases. Therefore, discovering new antiviral drugs against HIV-1 is crucial. This study aimed to explore a novel machine learning approach to classify compounds that inhibit HIV-1 integrase and screen the dataset of repurposing compounds. The present study had two main stages: selecting the best type of fingerprint or molecular descriptor using the Wilcoxon signed-rank test and building a computational model based on machine learning. In the first stage, we calculated 16 different types of fingerprint or molecular descriptors from the dataset and used each of them as input features for 10 machine-learning models, which were evaluated through cross-validation. Then, a meta-analysis was performed with the Wilcoxon signed-rank test to select the optimal fingerprint or molecular descriptor types. In the second stage, we constructed a model based on the optimal fingerprint or molecular descriptor type. This data followed the machine learning procedure, including data preprocessing, outlier handling, normalization, feature selection, model selection, external validation, and model optimization. In the end, an XGBoost model and RDK7 fingerprint were identified as the most suitable. The model achieved promising results, with an average precision of 0.928 ± 0.027 and an F1-score of 0.848 ± 0.041 in cross-validation. The model achieved an average precision of 0.921 and an F1-score of 0.889 in external validation. Molecular docking was performed and validated by redocking for docking power and retrospective control for screening power, with the AUC metrics being 0.876 and the threshold being identified at -9.71 kcal mol-1. Finally, 44 compounds from DrugBank repurposing data were selected from the QSAR model, then three candidates were identified as potential compounds from molecular docking, and PSI-697 was detected as the most promising molecule, with in vitro experiment being not performed (docking score: -17.14 kcal mol-1, HIV integrase inhibitory probability: 69.81%).

Effects of polymer-surfactant interactions on drag reduction performance and mechanisms: Molecular dynamics simulations and experimentation

This work provides a more favorable implementation of synergistic drag reduction strategies based on molecular simulations of the strength of polymer-surfactant interactions. The simulated preferred system identifies polyethylene oxide (PEO) and guar gum (GG) as polymers, and dodecyl dimethyl benzyl ammonium chloride (DDBAC) and dodecyl hydroxy sulfobetaine (DHSB). To forecast the drag reduction capability and identify the drag reduction process, important elements such as aggregation phenomena, charge distribution, shear deformation, and interfacial behavior were examined. Experimental measurements of viscosity, surface tension, and drag reduction validate the interactions. It was found that the compound system demonstrates enhanced viscosity, surface tension, and drag reduction efficiency compared to individual systems. The PEO-DHSB system achieves a drag reduction rate of 63.68% during initial flow, while the GG-DHSB system maintains a rate of 47.26% even after prolonged water circulation. This work visualizes the poly-surface aggregation phenomenon using the density distribution of surfactant hydrophobic tail chains, dynamically demonstrating the deformation of polymer and surfactant molecules during the shear process and interfacial behavior, and providing molecular-scale intuitive insights for understanding the drag reduction mechanism of poly-surface systems. Meanwhile, by comparing the effects of molecular type and structure on poly-surface interactions and drag reduction performance, it provides a theoretical foundation for the development and application of subsequent poly-surface drag reduction schemes, thereby broadening the application of drag reduction technology in the field of energy conservation and emission reduction.

Chitosan Rheological Behavior in an Acidic Water Mixture for Pharmaceutical and Biomedical Applications

The importance of chitosan (CH) has grown significantly over the last two decades due to its renewable and biodegradable source, and also because of the recent increase in the our knowledge of its functionality in technological and biomedical applications. The present article reviews the biopolymer CH and its derivatives, as versatile biomaterials for potential drug delivery systems, as well as tissue engineering applications, analgesia and treatment of arthritis. CH and its derivatives, as natural antimicrobial agents, can be applied in biomedical, biotechnological, and pharmaceutical applications. Its antimicrobial activity depends on many factors such as its molecular size, source, associated components, concentration, and type of microorganism. In our research described here we prepared and characterized the dynamic viscosity and the rheological properties of a biopolymer material based on CH in solution in acidic water. The dynamic viscosity and shear stress were measured under the influence of an increasing CH concentration of 1–10 g/l and an increasing temperature of 288.15–318.15 K.

Synthesis, Structure, and Hirshfeld Surface Analysis of tetrakis(N,N’-diethylthiourea)bis(isothiocyanato)nickel

The complex compound tetrakis(N,N’-diethylthiourea)bis(isothiocyanato)nickel or [Ni(detu)4(NCS)2] (denoted as UMCC-1) has been synthesized by reflux method in two different solvents namely acetone and methanol. This study aims to synthesize, characterize, and analyze the Hirshfeld Surface complex UMCC-1, which was obtained using the reflux method with the mole ratio of NiCl2: detu: KSCN is 1:2:4. Single crystals UMCC-1 in acetone and methanol are dark green in color with melting points of 135-137°C and conductivity of 66.4-84.4 µS. The FTIR absorption band analysis of the two crystals is very similar, ν(C S) detu 590 cm−1 and ν(C≡N) isothiocyanate 2119 cm−1. The refinement of the crystal structure from the single crystal XRD data shows that the two dark green crystals are a molecular type that has a distorted octahedral geometry with the same crystal lattice, monoclinic crystal lattice, P21/c1 space group (no.14), crystal lattice parameter a= 11.112(3) Å, b= 17.249(5) Å, c= 9.647(3) Å, and β= 100.785(10). However, the complex produced in acetone solvent has better refinement quality than methanol concerning %R= 3.27 and %R = 4.55, respectively. The UMCC-1 crystal shows intermolecular hydrogen bonds N-H---S(isothiocyanato) and intramolecular hydrogen bonds N-H---S(detu) with Hirshfeld Surface analysis showing a significant contribution of H---H (69.5%) on crystal packing.

Analysis of clinicopathological features and prognostic factors of breast cancer brain metastasis.

Breast cancer (BC) has become the most common malignancy in women. The incidence and detection rates of BC brain metastasis (BCBM) have increased with the progress of imaging, multidisciplinary treatment techniques and the extension of survival time of BC patients. BM seriously affects the quality of life and sur-vival prognosis of BC patients. Therefore, clinical research on the clinicopathological features and prognostic factors of BCBM is valuable. By analyzing the clinicopathological parameters of BCBM patients, and assessing the risk factors and prognostic indicators, we can perform hierarchical diagnosis and treatment on the high-risk population of BCBM, and achieve clinical benefits of early diagnosis and treatment. To explore the clinicopathological features and prognostic factors of BCBM, and provide references for diagnosis, treatment and management of BCBM. The clinicopathological data of 68 BCBM patients admitted to the Air Force Medical Center, Chinese People's Liberation Army (formerly Air Force General Hospital) from 2000 to 2022 were collected. Another 136 BC patients without BM were matched at a ratio of 1:2 based on the age and site of onset for retrospective analysis. Categorical data were subjected to χ2 test or Fisher's exact probability test, and the variables with P < 0.05 in the univariate Cox proportional hazards model were incorporated into the multivariate model to identify high-risk factors and independent prognostic factors of BCBM, with a hazard ratio (HR) > 1 suggesting poor prognostic factors. The survival time of patients was estimated by the Kaplan-Meier method, and overall survival was compared between groups by log-rank test. Multivariate Cox regression analysis showed that patients with stage III/IV tumor at initial diagnosis [HR: 5.58, 95% confidence interval (CI): 1.99-15.68], lung metastasis (HR: 24.18, 95%CI: 6.40-91.43), human epidermal growth factor receptor 2 (HER2)-overexpressing BC and triple-negative BC were more prone to BM. As can be seen from the prognostic data, 52 of the 68 BCBM patients had died by the end of follow-up, and the median time from diagnosis of BC to the occurrence of BM and from the occurrence of BM to death or last follow-up was 33.5 and 14 mo, respectively. It was confirmed by multivariate Cox regression analysis that patients with neurological symptoms (HR: 1.923, 95%CI: 1.005-3.680), with bone metastasis (HR: 2.011, 95%CI: 1.056-3.831), and BM of HER2-overexpressing and triple-negative BC had shorter survival time. HER2-overexpressing, triple-negative BC, late tumor stage and lung metastasis are risk factors of BM. The presence of neurological symptoms, bone metastasis, and molecular type are influencing prognosis factors of BCBM.

Synthesis of poly(D,L-lactide) with controlled molecular weight and type of end-groups

The synthesis of poly(D,L-lactide) with a predetermined molecular weight ranging from 5 to 143 kDa was conducted by ringopening polymerization of lactide in the presence of varying concentrations of the 1,12-dodecanediol activator. To synthesize poly(D,L-lactide) with COOH-end groups, polymerization was carried out in the presence of L-lactic acid. The synthesised polymer was found to contain an order of magnitude higher concentration of COOH groups than poly(D,L-lactide) synthesised in the presence of 1,12-dodecanediol.

Modern possibilities for the correction of menopausal symptoms in patients with breast cancer, depending on the molecular biological characteristics of the tumor (literature review)

Breast cancer (BC) ranks first in cancer incidence among women. For successful treatment of BC, depending on the molecular type and stage of the disease, chemotherapy is used, the side effects of which are manifested by menopausal symptoms, sexual dysfunction, and depressive states. However, not all patients after BC receive appropriate therapy for menopausal symptoms, what significantly worsens their quality of life. One of the symptoms that brings the most severe discomfort is the vasomotor symptom, a form of temperature dysfunction with peripheral vasodilation and increased cutaneous blood flow that results in increased heat loss. There are several types of drugs that are used to prevent menopausal symptoms in patients taking endocrine chemotherapy, many of which are in the experimental phase of development. In this review, we will try to identify proven effective and safe methods for correcting menopausal symptoms in women who underwent chemotherapy and endocrine therapy for BC.

Adipose-enriched peri-tumoral stroma, in contrast to myofibroblast-enriched stroma, prognosticates poorer survival in breast cancers

Despite our understanding of the genetic basis of intra-tumoral heterogeneity, the role of stromal heterogeneity arising from an altered tumor microenvironment in affecting tumorigenesis is poorly understood. In particular, extensive study on the peri-tumoral stroma in the morphologically normal tissues surrounding the tumor is lacking. Here, we examine the heterogeneity in tumors and peri-tumoral stroma from 8 ER+/PR+/HER2− invasive breast carcinomas, through multi-region transcriptomic profiling by microarray. We describe the regional heterogeneity observed at the intrinsic molecular subtype, pathway enrichment, and cell type composition levels within each tumor and its peri-tumoral region, up to 7 cm from the tumor margins. Moreover, we identify a pro-inflammatory adipose-enriched peri-tumoral subtype which was significantly associated with poorer overall survival in breast cancer patients, in contrast to an adaptive immune cell- and myofibroblast-enriched subtype. These data together suggest that peri-tumoral heterogeneity may be an important determinant of the evolution and treatment of breast cancers.

Measurements, correlations and thermodynamic modeling of aqueous two-phase systems of polyvinylpyrrolidone (PVP) + sulfate/citrate salts

Aqueous two-phase systems (ATPS) can be described as an alternative to traditional liquid-liquid extraction systems, typically consisting of a polymer and a salt solution. An alternative polymer called polyvinylpyrrolidone (PVP) has emerged as a viable option for ATPS due to its low cost, stability, and potential. This study aimed to investigate the effect of the molecular weight of poly (vinylpyrrolidone) (PVP) (K17, K25, and K30) and the temperature (298.15, 303.15, and 308.15 K) in the system ATPSs composed of PVPs and sodium sulfate/potassium sulfate/tri sodium citrate. The tie-line data were determined by measuring the density (ρ) and refractive index (nD). Moreover, the phase compositions and plait point are investigated for different PVPs molecular weight, temperature, and salt type. In addition, the effect of these parameters on the binodal curve, tie-line length (TLL), and slope of tie line (STL) are analyzed in detail by comparing them with the literature data. The impact of the parameters on the binodal curves was investigated by utilizing the values of the effective excluded volume parameter (EEV) that were calculated from the LLE data. Furthermore, the binodal curves and the tie-line compositions were well-fitted by using some semi-empirical equations. The phase separation ability is enhanced with temperature and PVPs molecular weight. The modified UNIFAC-NRF is used to correlate the liquid-liquid equilibrium data of the studied systems and the optimized binary group interaction parameters were determined.

Association between Ki67 Index and Clinicopathological Parameters in Breast Cancer Patients in Bali

Aim: To assess the association between Ki67 index and various clinicopathological parameters of breast cancer patients in Bali. Methods: This was a cross-sectional study of breast cancer patients at Prof. Dr. I. G. N. G Ngoerah Hospital, a referral hospital in Bali, from 1 January 2021 to 31 December 2021. Clinicopathology data was taken from SIMARS and archives in the Anatomical Pathology Laboratory. Ki67 index was assessed by immunohistochemical examination, categorized into low (Ki67 index &lt;20%) and high (Ki67 index?20%). Association between Ki67 index with clinicopathological parameters was analysis with X2 test with significance level determined at ?=0.05. Results: There were 75 cases of breast cancer patients with a mean age was 50.74 ± 10.05 years old. Low Ki67 index was found in 9 (12%) cases, while high Ki67 index in 66 (88%) cases. There was a significant association between Ki67 index and histological grade of the tumor (p=0.007), nodal status (p=0.014), and molecular subtype of tumor (p=0.007). There was no significant association between Ki67 index and the patient's age (p=0.268), histological subtype (p=0.086), and T stage (p=0.511). Conclusion: Ki67 index has significant association with histological grade of the tumor, nodal status, and the molecular type of the tumor in breast carcinoma patients in Bali.

Genotypic diversity of staphylococcal enterotoxin B gene (seb) and its association with molecular characterization and antimicrobial resistance of Staphylococcus aureus from retail food

To investigate the expression pattern of staphylococcal enterotoxin B (SEB) in food and the genotypic diversity of SEB-encoding gene in association with molecular characteristics and antimicrobial resistance of S. aureus, 498 isolates from retail food were screened for seb gene and detected for SEB production in S. aureus. In addition, the seb nucleotide sequences, virulence genes, resistance genes, antimicrobial susceptibility and molecular characteristics of S. aureus were examined. A total of 45 (9.0 %) seb-positive S. aureus strains were identified, all of which expressed SEB. The detection rate of SEB-production strains was significantly higher from dairy-related sources than those from other sources (P < 0.05). In vitro simulations showed that S. aureus could grow and express SEB in both milk and pork, with SEB expression exceeding 20 ng/g after 1 day of storage at room temperature. There were 2 distinct SEB genotyping (SEB1 and SEB2) in the SEB amino acid sequences of the 45 isolates, including 4 amino acid differences (Ala-13Val, Ser14Ala, Asn192Ser, and Met222Leu). There was no significant difference (P > 0.05) in SEB production between SEB1 and SEB2 genotyping strains. Based on MLST clustering analysis, the same molecular type strains were found to have the same SEB genotyping, virulence gene profile, resistance gene profile and drug resistance profile. Among them, the dominant molecular types of SEB1 and SEB2 strains were CC1-ST188-t189 and CC59-ST59-t437, respectively. Compared to the CC1-ST188-t189 clonal strain, the CC59-ST59-t437 clonal strain carried a higher number of virulence and resistance genes and exhibited a broader resistance profile. Therefore, understanding the characteristics of the strains and their expression patterns in food can be effective in preventing food poisoning incidents.

Risk factors of breast cancer recurrence in pathologic complete response achieved by patients following neoadjuvant chemotherapy: a single-center retrospective study.

Pathologic complete response (pCR) of breast cancer after neoadjuvant chemotherapy (NAC) is highly related to molecular subtypes. Patients who achieved tumor pCR after NAC have a better prognosis. However, despite of better prognosis, pCR patients have a potential for recurrence. There is little evidence of risk factors of recurrence in patients with pCR. We aim to analyze factors associated with tumor recurrence in patients who achieved pCR. This study retrospectively reviewed the data of patients diagnosed with breast cancer who achieved pCR after receiving NAC between January 2009 and December 2018 in Samsung Medical Center. pCR was defined as no residual invasive cancer in the breast and axillary nodes even if there is residual ductal carcinoma in situ (ypT0 or ypTis with ypN0). Breast cancers are classified into 4 subtypes based on hormone receptors (HR) and human epithelial growth factor receptor 2 (HER2) status. Patients who had bilateral breast cancer, ipsilateral supraclavicular or internal mammary lymph node metastasis, inflammatory breast cancer, distant metastasis, unknown subtype, and histologically unique case were excluded from the study. In total 483 patients were included in this study except for patients who corresponded to the exclusion criteria. The median follow-up duration was 59.0 months (range, 0.5-153.3 months). Breast cancer recurred in 4.1% of patients (20 of 483). There was a significant difference in clinical T (P = 0.004) and clinical N (P = 0.034) stage in the Kaplan-Meier curve for disease-free survival. Molecular subtypes (P = 0.573), Ki67 (P = 1.000), and breast surgery type (P = 0.574) were not associated with tumor recurrence in patients who achieved pCR after NAC. In the clinical T stage and clinical N stage, there was a significant difference between recurrence and no-recurrence groups (clinical T stage; P = 0.045, clinical N stage; P = 0.002). Univariable Cox regression revealed statistical significance in the clinical T stage (P = 0.049) and clinical N stage (P = 0.010), while multivariable Cox regression demonstrated non-significance in the clinical T stage (P = 0.320) and clinical N stage (P = 0.073). Results in this study showed that clinical T, clinical N stage, and molecular subtypes were not statistically significant predictors of recurrence in patients who achieved pCR after NAC. In spite of that, pCR after NAC may be more important than clinical staging and molecular subtype in early breast cancer. In addition, escalated treatments for patients with HER2 + or triple-negative tumors would be considered with a strict patient selection strategy to prevent over-treatment as well as achieve pCR.

Antimicrobial susceptibilities of Neisseria gonorrhoeae in Canada, 2021.

In Canada, gonorrhea is the second most prevalent bacterial sexually transmitted infection. The Gonococcal Antimicrobial Surveillance Programme (GASP - Canada), a passive surveillance system monitoring antimicrobial resistance in Neisseria gonorrhoeae in Canada since 1985, is the source for this summary of demographics, antimicrobial resistance and N. gonorrhoeae multi-antigen sequence typing (NG-MAST) of gonococcal isolates collected in Canada in 2021. Provincial and territorial public health laboratories submitted N. gonorrhoeae cultures and data to the National Microbiology Laboratory in Winnipeg as part of the surveillance system. The antimicrobial resistance and molecular type of each isolate received were determined. In total, 3,439 N. gonorrhoeae cultures were received from laboratories across Canada in 2021, a 9.9% increase since 2020 (n=3,130). Decreased susceptibility to cefixime increased significantly (p<0.001) in 2021 (1.5%) compared to 2017 (0.6%). No significant change in decreased susceptibility to ceftriaxone was detected between 2017 and 2021 (0.6%) (p>0.001); however, one ceftriaxone-resistant isolate was identified. Azithromycin resistance decreased significantly (p<0.001) in 2021 (7.6%) compared to 2017 (11.7%); however, there was a significant increase (p<0.001) in the proportion of cultures with an azithromycin minimum inhibitory concentration of at least 1 mg/L (2017=22.2% to 2021=28.1%). In 2021, NG-MAST-19875 (15.3%) was the most prevalent sequence type in Canada; 20.3% of isolates with this sequence type were resistant to azithromycin. The spread of antimicrobial-resistant gonorrhea is a significant public health concern. The continued regional and national surveillance of antimicrobial resistance in N. gonorrhoeae is essential in ensuring effective treatment therapies are recommended.

First report of environmental isolation of Cryptococcus and Cryptococcus-like yeasts from Boyacá, Colombia

The Cryptococcus genus comprises more than 100 species, of which C. neoformans and C. gattii are the leading cause of cryptococcosis. The distribution of C. gattii and C. neoformans species complexes has been extensively studied and widely reported globally. Other species such as Naganishia albida, Papiliotrema laurentii, and Papiliotrema flavescens have been reported as pathogenic yeasts. Since there are no reports of environmental isolation in the Boyacá region (Colombia), this study aimed to isolate and characterize Cryptococcus and Cryptococcus-like yeasts from pigeon feces, Eucalyptus, and olive trees distributed in the municipalities of Tunja and Ricaute Alto. The environmental data was recovered, and the isolations obtained were identified by microscopy, biochemical test, MALDI-TOF MS, URA5-RFLP, and sequencing of the ITS and LSU loci. For the 93 pigeon dropping samples collected in Tunja, 23 yielded to C. neoformans, 3 to N. globosa, 2 N. albida and 1 to P. laurentii. Of the 1188 samples collected from olive trees, 17 (1.43%) positive samples were identified as C. gattii species complex (4), C. neoformans species complex (2), P. laurentii (3), N. albida (2), N. globosa (5) and P. flavescens (1). Likewise, specimens of C. neoformans presented molecular type VNI and molecular type VNII; for C. gattii the molecular types found were VGIII and one VGIV by URA5-RFLP but VGIII by MALDI-TOF and sequencing of the ITS and LSU. Therefore, it can be concluded that the species of Cryptococcus, Naganishia and Papiliotrema genera, are present in the environment of Boyacá, and show a predilection for climate conditions that are typical of this region.