Why does HER2-positive breast cancer metastasize to the brain and what can we do about it?

Breast cancer is the most frequent malignancy in women. However, in the middle and late stages, some people develop distant metastases, which considerably lower the quality of life and life expectancy. The brain is one of the sites where metastasis frequently happens. According to epidemiological research, brain metastases occur at a late stage in 30-50% of patients with HER2-positive breast cancer, resulting in a poor prognosis. Additionally, few treatments are available for HER2-positive brain metastatic breast cancer, and the mortality rate is remarkable owing to the complexity of the brain's anatomical structure and physiological function. In this review, we described the stages of the brain metastasis of breast cancer, the relationship between the microenvironment and metastatic cancer cells, and the unique molecular and cellular mechanisms. It involves cancer cells migrating, invading, and adhering to the brain; penetrating the blood-brain barrier; interacting with brain cells; and activating signal pathways once inside the brain. Finally, we reviewed current clinically used treatment approaches for brain metastasis in HER2-positive breast cancer; summarized the traditional treatment, targeted treatment, immunotherapy, and other treatment modalities; compared the benefits and drawbacks of each approach; discussed treatment challenges; and emphasized the importance of identifying potential targets to improve patient survival rates and comprehend brain metastasis in breast cancer.

Mass Tuberculosis Screening Among the Elderly: A Population-Based Study in a Well-Confined, Rural County in Eastern China.

BACKGROUND: Mass tuberculosis (TB) screening has been recommended in certain high-risk populations. However, population-based screening interventions have rarely been implemented. Whether mass screening improves health equity is unknown. METHODS: We implemented a mass TB screening intervention among elderly persons (>60 years old) in Lanxi County, China. Standardized questionnaires, physical examinations, and chest radiographs (CXRs) were administered to all participants. Systematic testing with computed tomography, smear, culture, or Xpert was performed among persons with an abnormal CXR. We assessed TB prevalence per 100 000 persons and constructed multivariable regression models among subgroups that were and were not screened. Medical insurance was categorized as participation in either a basic program with limited coverage or a more comprehensive coverage program. RESULTS: In total, 49 339 individuals (32% of the elderly population in Lanxi) participated in the screening. One hundred fifteen screened persons were diagnosed with TB (233 cases per 100 000 persons), significantly higher than persons not screened (168 cases among 103 979 person-years; prevalence-to-case notification ratio, 1.44 [95% confidence interval {CI}, 1.14-1.83]). This increase was largely driven by diagnosis of asymptomatic disease during mass screening (n = 57 [50% of participants with TB]). Participants with basic medical insurance were much more likely to be diagnosed through mass screening than by passive detection (adjusted odds ratio, 4.52 [95% CI, 1.35-21.28]). CONCLUSIONS: In a population-based, mass TB screening intervention encompassing >30% of the elderly population in a county in rural China, case finding was 44% higher than background detection, driven by diagnosis of TB without recognized symptoms. Importantly, mass screening identified TB in people with limited healthcare options who were less likely to be found through background case detection.

A prognostic signature associated with cell senescence predicts survival outcomes and strongly associates with immunotherapy and chemotherapy response in breast cancer.

The objective of this study is to assess the predictive potency of cell senescence-related genes (CSRGs) in breast cancer (BC) and establish a risk signature. Trascriptome data of CSRGs were obtained from the TCGA and GEO databases. Consensus clustering was used to generate CSRGs-based molecular clusters for BC patients. A CSRGs-derived risk signature was built using multiple Cox regression analyses of differentially expressed genes (DEGs) between clusters. The prognosis, immune infiltration, chemotherapy and immunotherapy response between different risk groups were analyzed and compared. Two molecular clusters of BC patients were generated on the basis of 79 differentially expressed CSRGs, which showed distinct prognosis and immune infiltration. A total of 1403 DEGs between the CSRGs-derived clusters were found, and 10 of them were independent prognostic genes that used to construct a risk signature. The results demonstrated that patients with older age and advanced stage presented with a higher risk scores. In addition, the risk signature was found to be associated with outcomes, immune infiltration, chemotherapy and immunotherapy response. Patients in the low-risk group showed a favorable prognosis and higher immunotherapy response than those in the high-risk group. Finally, we developed a highly stable nomogram that incorporates risk signature, chemotherapy, radiotherapy, and stage variables, enabling accurate prediction of the overall survival (OS) of individual patients. To conclude, the signature derived from CSRGs holds great promise as a biomarker for prognostic assessment of BC and may serve as a valuable tool in guiding immunotherapy.

Association of postoperative covert stroke and cognitive dysfunction among elderly patients undergoing non-cardiac surgery: protocol for a prospective cohort study (PRECISION study).

INTRODUCTION: The incidence of covert stroke and cognitive dysfunction has gradually increased due to an ageing population. Recently, a prospective cohort study reported perioperative covert stroke was associated with an increased risk of postoperative cognitive dysfunction (POCD) 1 year after non-cardiac surgery. However, the mechanism remains unclear. METHODS AND ANALYSIS: This is a prospective observational trial aiming to investigate the cumulative incidence of perioperative covert stroke and test the hypothesis that perioperative covert stroke associates with POCD in elderly patients undergoing non-cardiac and non-neurological surgery. Data on risk factors, brain MRI, cognitive function evaluation and serum immune-inflammatory cytokines will be collected and analysed. ETHICS AND DISSEMINATION: Ethical approval has been granted by the Medical Ethics Committee of Beijing Tiantan Hospital, Capital Medical University (reference number: KY2017-027-02). The results of this study will be disseminated through presentations at scientific conferences and publication in scientific journals. TRIAL REGISTRATION NUMBER: NCT03081429.

Determination and pharmacokinetics of DT-13 in rat plasma by LC-MS.

A sensitive and specific LC-MS assay for DT-13 in rat plasma was developed. DT-13 is an active steroidal saponin present in Liriopes Radix and is developed as an anti-tumor drug candidate. The samples were extracted by acetonitrile-mediated plasma protein precipitation. The chromatographic separation was carried out using a Ultimate C(18) column (250 mm × 4.6 mm, i.d., 5 µm) with a mobile phase composed of acetonitrile: 5 mmol/L aqueous ammonium acetate (60:40, v:v). The method was validated and the specificity, linearity (r(2)=0.9980 within 10-1000 ng/mL), lower limit of quantitation (LLOQ, 10 ng/mL), precision (intra- and inter-day <12.3%), accuracy (93.4-106.3%), recovery (91.0 ± 4.7%) and stability were determined. The method was applied to the pharmacokinetic study of DT-13 in rat plasma after intravenous and intragastric administration. The results showed DT-13 underwent a prolonged absorption and slow elimination with a low oral bioavailability (5.51%) in rats.

The protective effect of the cholinergic anti-inflammatory pathway against septic shock in rats.

To investigate the effects of the cholinergic anti-inflammatory pathway on hemodynamics, blood biochemistry, the plasma TNF-alpha level, and the nuclear factor-kappaB (NF-kappaB) activation during septic shock, male Sprague-Dawley rats were subjected to cecal ligation and puncture (CLP, a model of polymicrobial sepsis) or sham operation. Forty-eight rats were randomly assigned into six equal groups: sham CLP group; CLP group; VGX group was subjected to bilateral cervical vagotomy after CLP; STM group was subjected to bilateral cervical vagotomy after CLP plus the left vagus nerve trunk electrical stimulation; THA group was administered tetrahydroaminoacridine after CLP and bilateral cervical vagotomy; and alpha-BGT group was administered alpha-bungarotoxin before electrical stimulation of the vagus nerve. The right carotid artery was cannulated to monitor MAP. The plasma TNF-alpha level was measured using enzyme-linked immunosorbent assays. The hepatic NF-kappaB activation was determined by Western blotting. Cecal ligation and puncture produced progressive hypotension. Serum aspartate transaminase and alanine transaminase levels significantly increased after CLP challenge. The plasma TNF-alpha level and the hepatic NF-kappaB activation significantly increased after CLP alone or with bilateral cervical vagotomy compared with sham-operated group. Application of constant voltage pulses to the caudal vagus trunk significantly prevented the development of CLP-induced hypotension, alleviated the hepatic damage, and reduced the plasma TNF-alpha production, but electrical stimulation had no effect on the hepatic NF-kappaB activation. Tetrahydroaminoacridine administration after bilateral cervical vagotomy reversed hypotension and attenuated the plasma TNF-alpha response; in addition, it had no effect on the hepatic NF-kappaB activation. alpha-Bungarotoxin pretreatment significantly reversed the inhibitory effect of vagal electrical stimulation, but it had no effect on the hepatic NF-kappaB activation. Our results showed that the cholinergic anti-inflammatory pathway might produce a potential protective effect on polymicrobial sepsis in rats.

[Protective effect of the cholinergic anti-inflammatory pathway against hemorrhagic shock in rats].

OBJECTIVE: To investigate the effect of the cholinergic anti-inflammatory pathway on hemodynamics in hemorrhaged rats. METHODS: Hemorrhagic shock was induced by modified Wiggers method until mean arterial pressure (MAP) was stabilized within the range of 35 to 40 mm Hg (1 mmHg=0.133 kPa). Thirty male Sprague-Dawley rats were randomly divided into six groups: sham group, hemorrhagic shock (Hem) group, vagotomy (VGX) group, vagus stimulation (STM) group, cholinergic inhibitor (THA) group and N receptor inhibitor (alpha-BGT) group. The distal end of the left vagus nerve trunk was placed on bipolar platinum electrode connected to a stimulation module and controlled by an acquisition system. Stimuli with constant voltage (5 V, 2 ms, 1 Hz) were applied to nerve for 12 minutes, starting 5 minutes after MAP stabilized at a level of 35 to 40 mmHg. Before stimulation a blood pressure transducer was implanted in the common carotid artery for continuous registration of MAP. Blood samples and liver samples were collected from animals of all groups after stimulation. Serum levels of tumor necrosis factor-alpha (TNF-alpha) and liver nuclear factor kappa-B (NF-KappaB) were determined. RESULTS: MAP was markedly lowered at the end of bleeding, and the levels of serum TNF-alpha and liver NF-KappaB markedly increased 45 minutes after the bleeding was discontinued. Bilateral cervical vagotomy did not significantly modify the changes in serum TNF-alpha, but slightly increased liver NF-KappaB activation. Application of constant electric current to the distal end of the vagus trunk significantly reduced serum TNF-alpha and blunted liver NF-KappaB activation. Tetrahydroamino-acridine (THA,1.5 mg/kg, intravenous drip administration after bilateral cervical vagotomy reversed hypotension and attenuated serum TNF-alpha and liver NF-KappaB amounts, but alpha-bungarotoxin (1.0 microg/kg intravenous drip) pretreatment reverted the inhibitory effects of vagal stimulation. CONCLUSION: The result suggest that direct electrical stimulation of the vagus nerve and its transmitter can significantly attenuate peak serum TNF-alpha amounts, inhibit the expression of liver NF-KappaB, and prevent the development of hypotension, thus it might produce a potential protective effect on hemorrhaged rats through acetylcholine (Ach) binds NAch receptor alpha 7 subunit which exists in the macrophage.

[Protective effect of ketamine against septic shock in rats].

OBJECTIVE: To investigate the effects and the mechanism of ketamine on hemodynamics and pro-inflammatory cytokine levels of plasma in septic shock rats. METHODS: Cecal ligation and puncture (CLP) was used to reproduce septic shock model. Twenty healthy and male Sprague-Dawlay (SD) rats weighing (225+/-25) g were randomly divided into four equal groups: Sham CLP group, CLP group, ketamine I (KT I) and ketamine II (KT II) group. Thirty minutes before CLP, normal saline (0.9 %) was infused continuously at a rate of 5 ml.kg(-1).h(-1) through the left femoral vein cannula in sham CLP and CLP group, and ketamine (5 mg.kg(-1).h(-1) and 10 mg.kg(-1).h(-1), respectively) was infused continuously in KT I or KT II group. The right femoral artery was cannulated to monitor mean arterial pressure. The plasma levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were measured using enzyme-linked immunosorbent assays (ELISA). RESULTS: CLP produced progressive hypotension, and a large increase in the plasma TNF-alpha and IL-6 concentrations. The hemodynamic responses were reversed and the cytokine responses were suppressed in ketamine treated animals. CONCLUSION: Ketamine administration has protective effect against septic shock in CLP rats.