Temporal and spatial evolution and influencing factors of urban ecological total factor productivity in the Yellow River basin under strong sustainable development

A growing consensus worldwide has indicated the need to protect the ecological environment and achieve sustainable development. Ensuring ecological protection and high-quality development of the Yellow River basin have become China's major national strategy. We reviewed extant literature, summarised government reports and guidance documents on the Yellow River basin, and proposed introducing a strong sustainable development theory into the study of total factor productivity (TFP). The spatial-temporal evolution and influencing factors of urban ecological TFP in the Yellow River basin are of great practical significance. We proposed a new ecological TFP indicator: the modified input-oriented Luenberger productivity indicator (MIL). Using panel data from 78 cities in the Yellow River basin during 2003-2019, we measured the urban ecological TFP. We adopted the geographic information system tool and kernel density estimation to analyse the temporal and spatial evolution of the indicator, as well as its spatial effects and influencing factors, using the global Moran's I index and dynamic spatial Durbin model (SDM). Our results show that, during the sample period, our indicator increased in cities in the region with an average annual growth rate of 0.627%, driven by technological progress. The average annual growth rate in urban areas showed a decreasing distribution of 'downstream-midstream-upstream'. Fiscal decentralisation (FD), industrial structure (IND), financial development (FIN), urbanisation level (URB) and research and development (RD) investment improved growth rates in this and the adjacent regions through direct and indirect effects. However, environmental regulation (ER), opening level (OPEN) of cities and population density (POP) were obstacles to TFP growth.

[Identification of the feature of immune cells infiltration in inherited renal carcinoma with von Hippel-Lindau syndrome]

Objective: To investigate the feature of immune cells infiltration in inherited renal carcinoma with von Hippel-Lindau (VHL) syndrome and their relationship with clinicopathological characteristics and prognosis. Methods: The samples were collected from patients with VHL syndrome renal carcinoma who were diagnosed and treated surgically at the Department of Urology, Peking University First Hospital from 2010 to 2019. RNA-Seq was performed on 6 pairs of VHL syndrome renal carcinoma and adjacent normal tissues. To identify the specific infiltrated immune cells, RNA-Seq data was converted into the infiltration data of 14 types of immune cells using the TIP tool. Immunohistochemical staining was used to verify the expression of the markers of these specific infiltrated immune cells in the paraffin sections of 54 paired VHL syndrome renal carcinoma and adjacent normal tissues, and to analyze their relationship with clinicopathological characteristics and prognosis. Results: Compared with adjacent normal tissues, CD4 Naive infiltration level was significantly down-regulated (0.289±0.009 vs 0.200±0.012,P<0.001) and CD4 Memory infiltration level was significantly up-regulated (0.123±0.014 vs 0.222±0.016,P<0.001) in VHL syndrome renal carcinoma. Immunohistochemical staining results showed that CD45RA (a CD4 Naive cell marker) expression was significantly reduced (50.9±1.9 vs 15.6±0.9,P<0.001) and CD45RO (a CD4 Memory cell marker) expression was significantly increased (22.2±1.1 vs 80.8±4.3,P<0.001) in VHL syndrome renal carcinoma. Besides, lower CD45RA expression and higher CD45RO expression were associated with higher histological grade, advanced tumor stage and shorter disease-free survival (all P<0.01). In addition, CD45RA expression was positively correlated with VHL expression (r=0.693 3, P<0.000 1) and CD45RO expression was negatively correlated with VHL expression (r=-0.609 0, P<0.000 1). Conclusions: This study found that CD4 Naive and CD4 Memory cells may be differentially infiltrated immune cells in VHL syndrome renal carcinoma, and their infiltration levels were associated with the expression of VHL and the prognosis of patients.

[Clinicopathological and prognostic characteristics of clear cell papillary renal cell carcinoma]

Objective: To analyze the epidemiological, clinicopathological and prognostic characteristics of clear cell papillary renal cell carcinoma (CCPRCC) based on Chinese patient population. Method: Patients with renal cell carcinoma diagnosed at Peking University First Hospital from June 2016 to June 2020 were included in this study based on the inclusion and exclusion criteria. All cases were grouped according to CCPRCC, clear cell renal cell carcinoma (ccRCC), and papillary renal cell carcinoma (pRCC), and the general clinical, postoperative pathological and follow-up data of the patients were retrospectively analyzed. Result: A total of 18 CCPRCC patients were enrolled in this study, accounting for 0.44% (18/4 110) of the postoperative pathologically confirmed renal cell carcinoma cases in our hospital during this time period. The age range of the included patients was 28-86 years old, with a median age of 49.5 years old. There were 11/18 males and 7/18 females. All CCPRCC patients had no family history of renal malignant tumors. Among them, only one patient with CCPRCC had related clinical symptoms, that was intermittent waist and abdomen pain, while the other 17 cases were found by physical examination without any related symptoms. Compared with ccRCC and pRCC, there was no significant difference in their end stage renal disease history(χ²_ccRCC=0.291, χ²_pRCC=1.161,all P>0.05). The maximum diameter of CCPRCC tumor was smaller than pRCC (χ²=-2.280,P =0.027) but not significantly different from ccRCC (χ²=-0.579,P =0.565). The majority of patients with CCPRCC were in pT1, their pathological stage was earlier than the other two types, and their overall survival was better than ccRCC and pRCC (P<0.05). Conclusion: CCPRCC is a type of renal cell carcinoma with unique epidemiology, clinicopathology and prognostic characteristics. Patients with this subtype have an earlier clinical stage and a better prognosis than ccRCC and pRCC.

[Legal Risk Management in Nursing Practice: The Importance of Duty of Care]

The steady and continued rise in medical-related disputes and lawsuits is one indicator of the myriad risks and challenges faced in today's nursing practice. When nurses become defendants, the lengthy litigation process and pressures that ensue greatly impact their professional and personal lives. Nursing practice dispute categories marked by particularly high severity and frequency over the past ten years include: (1) Failure to operate according to standard procedures, (2) Insufficient nursing sensitivity and negligent care, (3) Failure to communicate and deal with issues promptly and appropriately, (4) Beyond the scope of nursing practice, and (5) Falsification or alteration of nursing records. In this paper, the important duties of care in four major nursing practices are first summarized based on the relevant legal risks. Next, based on this, risk management procedures are prioritized, evidence-oriented nursing routine standards are set, and systematic analysis and management are conducted. In addition, to strengthen the legal awareness of nurses, nursing staffs, supervisors, and institutions must all understand clearly the three types of civil and criminal legal liabilities and their respective administrative responsibilities. Nurses should proactively work to handle the related legal risks and avoid the unpleasant consequences of civil liability in the realms of compensation, criminal punishment for negligent injury and homicide, and administrative disciplinary action.

[Reflections on the Nursing Work Environment in Light of the Experience With COVID-19]

Labor issues related to the nursing profession have been gaining prominence in Taiwan as well as overseas. In 2016, the United Nations highlighted the importance of societies investing sufficient funds in their professional nurses to support and promote public health, gender equality, and economic growth. Good-quality care requires that nurses have good physical and mental health, while creating and maintaining a friendly nursing work environment rely on cooperation among the government, labor unions, and hospitals. Over the past decade, the Taiwan government has increasingly promoted relevant regulations and established a friendly platform to allow nursing staffs to identify problems and report labor rights violations. In addition, nurses have formed unions to defend and advocate for their professional rights. After the outbreak of COVID-19 in late 2019, the Department of Nursing and Health Care of the Ministry of Health and Welfare actively proposed policies related to creating and maintaining good nursing work environments. The Taiwan Nursing and Medical Industries Union took a supervisory role in this process, providing feedback on policies from the perspective of Taiwan's professional nurses and arguing for the reasonable and fair subsidization of epidemic prevention facilities, implementation of mask and protective equipment, nursing labor rights, and social respect for the nursing profession. Much work still needs to be done to improve the domestic working environment for nursing staffs, including improving and expanding education, normalizing and effectively utilizing nursing staff feedback and whistleblowing information, promoting information transparency, and implementing better policies. We hope that a friendlier nursing work environment will attract many more outstanding young persons to pursue a career in nursing.

[Esculin inhibits proliferation of triple negative breast cancer cells by down-regulating FBI-1]

Objective: To investigate the effect of esculin on the proliferation of triple negative breast cancer cells and its molecular mechanism. Methods: MDA-MB-231 cells were treated with 28, 56, 112, 225, 450 and 900 μmol/L of esculin for 24, 48 and 72 h, respectively, and the cell viability was detected by cell counting kit 8 (CCK-8) assay. In addition, MDA-MB-231 cells were treated with 0, 225, 450 and 900 μmol/L of esculin for 48 h. And then the changes in cell morphology were observed by inverted microscope. The clone-forming ability was detected by colony formation assay. The mRNA expression levels of FBI-1, p53 and p21 were detected using real-time fluorescence quantitative polymerase chain reaction. The protein expression levels of FBI-1, p53, p21 and Ki67 were detected by western blot. Results: Compared with the blank control group, the cell viability of MDA-MB-231 cells that treated with esculin significantly decreased in a dose-dependent and time-dependent manners. After treatment with esculin, MDA-MB-231 cells shrunk, flattened, adhered poorly to the culture dish and the cell spacing became larger. Meanwhile, shedding and incomplete cells appeared, of which 900 μmol/L of esculin treatment group showed the most dramatic changes. In addition, the colony formation ratios were decreased to (77.18±5.13)%, (65.94±4.98)% and (45.92±3.70)% in the 225, 450 and 900 μmol/L of esculin treatment groups compared with blank control, respectively (P<0.01). Furthermore, the mRNA and protein expressions of FBI-1 increased, while the levels of p53 and p21 mRNA and protein, as well as the protein expression of Ki67 decreased in a concentration-dependent manner (P<0.01). Conclusion: Esculin may regulate cell cycle-related p53-p21 pathway via FBI-1 mediated DNA replication, thus inhibit the proliferation of triple negative breast cancer cells.

[Eosinophilic solid and cystic renal cell carcinoma with TSC2 gene mutations in children]

Objective: To study clinical pathological characteristics, immunohistochemical, molecular genetical changes and prognosis in pediatric eosinophilic solid and cystic renal cell carcinoma (ESC RCC) with TSC2 gene mutations. Methods: The tissue samples were collected from two pediatric ESC RCC patients between 2017 and 2018. The tissues were subjected to histological examination and immunohistochemistry using EnVision system. The TFE3, TFEB gene rearrangements were tested using FISH and molecular genetic study. The paraffin sections were used for DNA extraction, PCR amplification and NGS sequencing. Results: The two patients with ESC RCC were both male, aged at 9 years and 8 months, and 13 years, respectively. The tumors were from the right kidney, 5 cm and 7 cm in size, respectively, with solid and cystic changes in cross section, and grey-reddish or grey-whitish fish meat appearance. Microscopic observation revealed the tumors had fibrous capsules, which were infiltrated by the tumor cells. The tumor cells were diffusely distributed, round-shaped, or polygon-shaped, and had voluminous cytoplasm, eosinophilic cytoplasm, various sizes of vacuoles and clear cell-like appearance. There were papillary structures in some areas, with visible fiber septa. The nuclei were round and vesicular, with multi-nucleated cells and megakaryocytes. The mitoses were not seen. A few cystic structures were visible in different sizes, and capsule walls were covered with a single layer of spike-like tumor cells. Thick-walled blood vessels were seen in the stroma, with focal lymphocytic infiltration, eosinophilic necrosis, calcifications and cholesterol crystals. Immunohistochemistry of the tumor cells was positive for PAX8 (diffuse), CK20 (focal), CKpan (focal), CK10 (1 focal, 1 diffuse), INI1, vimentin, CD68, and Ki-67 (5%~10%); the tumor cells were negative for HMB45, S-100, Melan A, p53, desmin, TFE3, CK7, CK19, EMA, CD56, CgA, Syn, CD30, CD117, WT1 and SMA. Molecular genetic study showed that TFE3 and TFEB gene rearrangements were not detected by FISH. NGS sequencing showed TSC2 p.Lys574Ter (0.198) was found in patient one and TSC2 p.Arg406Ter (0.355) in patient two. Conclusions: ESC RCC in children is a rare disease, and can be misdiagnosed easily. It has unique pathological characteristics, and immunohistochemical, molecular and genetic changes. The prognosis is relatively good.

[Exploring the Stress, Psychological Distress, and Stress-relief Strategies of Taiwan Nursing Staffs Facing the Global Outbreak of COVID-19]

BACKGROUND

The global outbreak of coronavirus disease (COVID-19) began in December 2019. The high levels of stress experienced by nurses during this pandemic may have immediate and long-term effects on their mental health.

PURPOSE

To explore the stress and psychological problems of nurses during this pandemic and to identify strategies used by these nurses to relieve stress.

METHODS

A cross-sectional online survey was conducted that included a basic information datasheet, stress of nursing staff during COVID-19 outbreak scale, psychological distress scale, and stress relief methods survey form. Convenience sampling was used and a total of 469 practicing nurses participated in this study.

RESULTS

Most of the participants expressed concerns about living problems (72.7%). On the stress questionnaire, the facets of "burden of taking care of patients" and "worries about social isolation" earned the first and second highest scores, respectively. In terms of items, "worrying about infecting family members and friends" and "worrying about being separated from family after being infected" earned the two highest scores (2.35 ± 0.79 and 2.17 ± 0.92, respectively). Scores for psychological distress averaged 5.49 ± 3.83, with stress anxiety (1.32 ± 0.84) earning the highest mean subscale score followed by distress and irritability (1.17 ± 0.92) and depression (1.12 ± 0.94). Nearly two-thirds (61.8%) of the participants earned psychological and emotional distress scores within the 'normal' range, and 3.4% earned scores indicating severe distress. "Receiving education and training" was the most common method used by the participants to relieve stress (2.27 ± 0.51).

CONCLUSIONS

The following six strategies are proposed based on the above findings: (1) Caring: provide psychological assessment and care; (2) Supporting: create a friendly team atmosphere and provide support; (3) Inquiring: recruit volunteers with relevant experience; (4) Informing: provide timely, open, and transparent epidemic-prevention information; (5) Equipping: provide complete and appropriate epidemic-prevention education and training; (6) Assisting: establish a strategy for family support and caring to reduce the stress and worries of nurses.

[Infection Control: The Roles and Functions of Nurses Working at the International Medical Center]

Travelers are known to convey infectious diseases across international borders. After its experience with SARS, Taiwan established a comprehensive mechanism at its border to prevent the entry of infectious diseases. However, people with chronic infectious diseases, carriers with no symptoms, and those likely to be infected are not easy to identify during border screenings. Therefore, Taiwan must implement internal disease-containment measures in addition to stopping infectious disease at its borders. With increasing numbers of patients coming to Taiwan for medical examinations, medical aesthetic treatments, and medical treatments and care, the risk of acute, chronic, and contagious diseases originating from non-residents must be considered and addressed. This article was developed to discuss the role and importance of nurses in preventing transnational infectious diseases from the perspective of international medical care. In addition to showing rich nursing experience, sensitivity, and conducting the management and communication of international cases, it is also necessary to make good use of information tools for remote screening care. Taking the period of the COVID-19 outbreak as an example, several procedures have been conducted. First, online detailed history of infectious diseases and nursing evaluations are conducted before admission. Second, preparation and movement notifications are given before admission. Third, online health education and follow-up care as well as cross-unit communication and coordination are implemented. International medical nurses directly affect the quality and effectiveness of international medical treatment. As Taiwan builds up its brand as an international medical caring destination, nursing professionals should help further this trend and announce to the world: Taiwan can help! Nursing can help!

[A Challenge for Home-Based Hospice Care: Good Death at Home]

Taiwan is expected to become a "super-aged" nation in 2065. Modern medical advancements, while extending the average human lifespan, has led to higher incidence of patient suffering and greater medical expenses due to chronic disease and terminal illnesses. As the concept and services of hospice and palliative care have become increasingly accepted by the public, the issue of final care for a good death has become a priority concern for both patients and their families. Experiencing a good death at home is a common last wish for terminal patients. However, guidelines for good death at home are still unavailable in Taiwan. The promotion of this concept thus remains a challenge with many limitations. This article aims to explore: (1) the importance of hospice care; (2) the selection of a proper location for good death; (3) the requirements for nursing education in the care of dying patients; and (4) the challenges and strategies of a good death at home, including "the family dimension-connections with the family members" and "the education dimension-promotion of home-based dying in nursing education". The goal is to help terminal patients experience a good death at home, to assist family members embrace the good death of their loved ones, and, eventually, to facilitate peaceful and successful home-based dying for both the patient and their family members.

[Analyses of the Expression of FBI-1 in Breast Cancer Pre- and Pro-neoadjuvant Chemotherapy]

Objective: To investigate the expression of factor that binds to inducer of short transcripts-1 of HIV (FBI-1)in breast cancer pre- and pro-neoadjuvant chemotherapy and explore the relationship between FBI-1 expression and treatment efficacy. Methods: We collected 50 patients with breast cancer who received neoadjuvant chemotherapy before operation in the Affiliated Tumor Hospital of Guangxi Medical University from January, 2010 to December, 2014. The expression of FBI-1 in breast cancer tissues pre- and pro-neoadjuvant chemotherapy was detected by immunohistochemical staining. We compared the level of FBI-1 expression pre- and pro-neoadjuvant chemotherapy, and tried to explore its relationship with patient and tumor characteristics and treatment efficacy. Results: (1) The rate of upregulated expression of FBI-1 in breast cancer tissues was 70% (35/50). The upregulated expression of FBI-1 was related to the higher clinical stage and trend of lymph node metastasis (P<0.05), whereas not related to the age and expression of ER, PR, Ki-67, and Her-2(P>0.05); (2) the setting of FBI-1 lower expression pre-neoadjuvant chemotherapy had superior treatment outcome than the high expression setting based on either clinical assessment (86.7% vs 51.4%, P=0.027) or pathological assessment(80.0% vs 28.6%, P=0.001); (3) the rate of upregulated FBI-1 expression was significantly decreased post-neoadjuvant chemotherapy(70.0% vs 38.0%, P=0.004), with FBI-1 expression of 22 patients downregulated (62.9%); (4) the expression of FBI-1 in responded setting was significantly decreased than that in the non-responded setting based on either clinical (77.4% vs 26.3%, P=0.001) or pathological (72.7% vs 39.3%, P=0.024) assessment. The downregulation of FBI-1 was correlated to either clinical efficacy (r=0.440, P<0.01) or pathological efficacy (r=0.491, P<0.05) of neoadjuvant chemotherapy. Conclusion: In breast cancer patients receiving neoadjuvant chemotherapy, the upregulated expression of FBI-1 in breast cancer lesion is associated with clinical stage and lymph node metastasis. The neoadjuvant chemotherapy can significantly reduce the expression of FBI-1. The upregulated expression of FBI-1 may be predictive of resistance to chemotherapeutic drugs, and has predictive value for the efficacy of neoadjuvant chemotherapy in breast cancer patients.

[Prognostic value of pretreatment (18)F-FDG PET-CT for patients with advanced diffuse large B-cell lymphoma]

Objective: To investigate the prognostic value of the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) measured by pretreatment (18)F-FDG PET-CT in patients with stage Ⅲ~Ⅳ diffuse large B-cell lymphoma (DLBCL). Methods: Clinical data of 72 DLBCL patients with stage Ⅲ~Ⅳ disease undergoing a pretreatment PET-CT scan were retrospectively analyzed. SUVmax, MTV and TLG values of whole-body tumor were calculated from PET-CT images with a threshold of SUVmax 40% of tumor tissues. The optimal cutoff lines of SUVmax, MTV and TLG were obtained by ROC curve analysis. The Kaplan-Meier method and Log-rank test were used to perform univariate survival analysis, while Cox proportional hazards model was done for multivariate analysis. Results: The SUVmax, MTV and TLG of 72 patients were 21.64, 139.48 cm(3) and 1 413.77, respectively. The areas under the ROC curve (AUC) of SUVmax, MTV and TLG were 0.411 (95%CI=0.279~0.544, P=0.195), 0.688 (95%CI=0.566~0.811, P=0.006) and 0.526 (95%CI= 0.469~0.672, P=0.123), respectively. The median SUVmax (21.64) and TLG(1 413.77) were used as the cutoff lines due to smaller AUC. The cutoff point of MTV was 69.71 cm(3). For DLBCL patients of stage Ⅲ~Ⅳ disease, univariate analysis showed that SUVmax and TLG were not associated with the progression-free survival (PFS) and overall survival (OS) (P>0.05 for all). Multivariate analysis showed that National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) but not MTV was the independent prognostic predictor of PFS and OS (P<0.05 for all). And MTV was not the independent prognostic factor of PFS and OS for stage Ⅲ DLBCL (P>0.05 for all). Conclusions: For DLBCL patients with stage Ⅲ~Ⅳ disease, the prognostic value of SUVmax, MTV and TLG before treatment initiation are undetermined, and these indices cannot be used to predict the prognosis.

[Mutual Support Beyond Suffering and Mortality-Spiritual Care for Families of Terminal Cancer Patients]

With the progression of cancer and the approach of death in terminal cancer patients, the suffering of the family members of patients increases drastically, often leading into a difficult spiritual journey. The needs for spiritual care in this population generally consist of: 1. Empathy: Bearing the psychological stress due to the sharing of physical pain with the patients; 2. Powerlessness: Regretting not having the power to turn the tide; 3. Loneliness: Becoming exhausted due to facing heavy physical workloads alone; 4. Break down: Feeling hopeless in the face of the myriad challenges of care; 5. Despair: Feeling perplexed by the prospects of a desperate future; 6. Sorrow: Feeling bitter due to the realization that the disease is incurable and to being reluctant to acknowledge the parting. The spiritual needs of family members may be met by evaluating the needs for and resistance to spiritual care, followed by the use of religious and non-religious companions and the application of listening and empathy approaches in order to elicit positive thoughts and the values of love, forgiveness, and reconciliation. In strengthening their personal beliefs, family members may find connectedness with god, humanity, and objects; may see hope in life; and may find the meaning of suffering in order to further seek and find inner peace, accomplish themselves, and eventually achieve spiritual sublimation.

[Evaluate the value of (18)F-FDG PET-CT imaging in predicting the mutationsin epidermal growth factor receptor in lung adenocarcinoma]

Objective: To investigate the value of maximum Standardized Uptake Value(SUVmax), Metabolic Tumor Volume (MTV) and Total Lesion Glycolysis (TLG) calculated from (18)F-FDG PET-CT in predicting the presence of epidermal growth factor receptor (EGFR) mutations in lung adenocarcinoma. Methods: We retrospectively reviewed 137 lung adenocarcinoma patients with EGFR mutations testing and pretreatment (18)F-FDG PET-CT. Receiver Operating Characteristic (ROC) curve analysis was performed to quantify the predictive value of SUVmax、MTV、TLG. A multivariate logistic regression analysis was used to evaluate the predictive value of EGFR mutation. Results: Among 137 lung adenocarcinoma patients, 86(62.8%, 86/137) were identified with EGFR mutations. The SUVmax, MTV and TLG were 7.4, 5.28 cm(3,) 20.20, respectively. The optimal cut-off values of SUVmax, MTV and TLG were 7.99(AUC=0.658, 95% CI=0.566~0.752, P=0.002), 6.09 cm(3)(AUC=0.644, 95% CI=0.550~0.737, P=0.005), 35.08(AUC=0.650, 95% CI= 0.557~0.744, P=0.003), respectively. Multivariate analysis showed that TLG and smoking status were the most significant predictors of EGFR mutation(all P<0.05). Conclusion: TLG in (18)F-FDG PET/CT is an independent factor for predicting EGFR mutation in patients with lung adenocarcinoma, and has certain reference value for predicting EGFR mutation.

[Efficacy observation of (125)I seed implantation therapy for locoregional recurrent and metastatic breast cancer]

OBJECTIVE

To assess the efficacy and side effects of (125)I seed implantation for locoregional recurrent and metastatic breast cancer, and to discuss its role in the comprehensive therapy of breast cancer.

METHODS

Forty-three patients with locoregional recurrent or metastatic breast cancer were included in this study. They received (125)I seed implantation and were followed up to evaluate the efficacy and adverse reactions of the treatment.

RESULTS

Among 54 lesions in the 43 cases, there were complete response (CR) in 39, partial response (PR) in 13, stable disease (SD) in 2 patients, with a response rate of 96.3%. All 17 cases with local pain achieved pain relief. With a median follow up of 36 months (range 14 to 60 months), the 1-, 3-, and 5-year local control rate was 85.2%, 53.7% and 1.9%, and the 1-, 3-, and 5-year survival rate was 95.3%, 67.4% and 37.2%, respectively. No serious radiotherapy side effect was observed.

CONCLUSION

In patients with unresectable locoregional recurrent or metastatic breast cancer, (125)I seed implantation shows proved efficacy and few complications, and can be an important treatment option.

Expression and clinical significance of Kelch-like epichlorohydrin-associated protein 1 in breast cancer

Our objective was to explore the expression and clinical significance of Kelch-like epichlorohydrin-associated protein 1 (Keap1) in breast cancer tissue. Eighty-one breast cancer patients having undergone surgical treatment in our hospital between March 2002 and December 2008 were enrolled in this study. Normal tissue adjacent to tumors was used for the control samples. Diagnoses for all patients were confirmed by postoperative pathological examination. Immunohistochemical assays were used to measure the expression of Keap1 protein in breast cancer tissue and adjacent normal tissue, and its clinical significance was explored. We observed that 24.6% breast cancer tissue samples were positive for Keap1, a significantly lower proportion than that seen with adjacent normal tissue specimens (80.2%; P < 0.05). The presence of Keap1 expression did not correlate with age, tumor size, pathological classification, or degree of differentiation. However, it was found to be significantly associated with tumor-node-metastasis stage and the presence of lymphatic metastasis. Kaplan-Meier survival analysis showed a remarkably higher five-year survival rate among patients with positive Keap1 expression than in those lacking detectable levels of the protein (P = 0.032). Keap1 expression is significantly decreased in breast cancer tissue; therefore, the early detection of its expression might have great significance in determining prognosis for breast cancer patients.

Building a bridge for nursing education and clinical care in Taiwan--using action research and Confucian tradition to close the gap

BACKGROUND

Nursing workplaces in Taiwan are unable to retain talent. An examination of this problem has revealed that the causes of this phenomenon are that nursing education fails to cultivate the skills that meet workplace requirements and that there are gap between nursing education and clinical practice.

OBJECTIVES

This paper is an action research that aims is to design educational programs that can close the gap between nursing education and clinical practice in Taiwan.

DESIGN

In this action research project, 4 action cycles were used to design educational programs including concept mapping and focused discussion strategies.

SETTINGS

Participants were invited to join the research in three teaching hospitals and one university.

PARTICIPANTS

Two groups of participants, student nurses (SN) and nursing staff personnel (NS), were sampled and invited to participate in the research.

METHODS

Participant observation, focus groups, and qualitative interviews were used to collect data. Qualitative data were not only profiled by content analysis, but they were also compared continuously between the two groups as well as between the 4 cycles.

RESULTS

The qualitative data collected for the 135 participants were analysed. The themes of an effective nursing program were summarized.

CONCLUSIONS

Many fundamental values of traditional Chinese education have gradually faded due to the Westernization of education. In this study, we discovered that Western educational models may play a critical role in improving traditionally taught nursing education programs.

“Does One Size Fit All?” Exploring the Cultural Applicability of NANDA Nursing Diagnoses to Chinese Nursing Practice

East Asia has historically unique concepts of health and well-being and thus is an appropriate setting for exploring the multicultural applicability of the North American Nursing Diagnosis Association’s Nursing Diagnoses (NANDA ND) system. This study aimed to explore how NANDA ND affect the growth and quality of professional nursing from the perspective of Taiwanese nurses. Grounded theory was employed in this interview-based investigation of 53 Taiwan-licensed nursing professionals at various hospitals in Taiwan. Data were analyzed using constant comparative analysis until theoretical saturation was reached. The core concept, Struggling with (the NANDA ND notion that) One Size Fits All, emerged after ongoing analysis of the effects of NANDA ND on good nursing, patient welfare, and professional development. The preliminary theoretical framework developed from this study provides evidence that NANDA ND may be incompatible with the cultural beliefs of the traditional Chinese health care setting in Taiwan, which emphasize holistic harmony and balance.

Bioethics education for practicing nurses in Taiwan: Confucian-western clash

To understand the gaps between current bioethics education and the requirements of practicing nurses, a semistructured questionnaire was used to invite the directors of nursing departments at all 82 teaching hospitals in Taiwan to participate in this survey. The response rate was 64.6%. Through content analysis we obtained information about previous bioethical training, required themes and content, recommended teaching strategies, and difficulties with education and its application. The results suggest that Taiwanese nursing personnel need to be instilled with both self-cultivation of morality and mental cultivation to acquire nursing virtues and the right attitudes toward bioethical issues. Good communication skills to prevent damage to the harmonious relationships between patients, their families and medical team members, policies that support the provision of systematic formal knowledge of ethics, small group training, and clarification of values were also shown to be important in bioethics education.

Efficacy of guided imagery with theta music for advanced cancer patients with dyspnea: a pilot study

BACKGROUND

Dyspnea is a frequent and devastating symptom among advanced cancer patients for which improved and low-cost palliative techniques are needed.

METHODS

A one-group repeated measures research design investigated the efficacy of guided imagery (GI) with theta music (M) on dyspnea in advanced cancer patients. The intervention consisted of four periods: (a) pretest; (b) intervention with peaceful non-M; (c) intervention with 10 min of GI with M (GI/M), with the first and last 3 min being M only (i.e., the middle 4 min was GI/M); and (d) posttest. Dyspnea outcome was measured with the Modified Borg Scale (MBS) for self-reported evaluation of dyspneic symptoms. Physiological parameters measured were pulse oxygen saturation (SpO(2)), end-tidal CO( 2) (EtCO(2)), heart rate (HR), and respiratory rate (RR). Posttest qualitative data were obtained via interview for subjective patient experience.

RESULTS

Participants included 53 patients, 33% with lung cancer. GI/M produced a significant decrease in MBS scores; 90% of the subjects gave positive qualitative reviews of GI/M. SpO(2) did not change significantly over time. GI/M significantly increased EtCO(2), decreased RR, and decreased HR.

DISCUSSION

This study demonstrates that GI/M is a useful intervention for palliative care of patients with dyspnea. M alone was demonstrated to be effective, while soothing non-M was not effective. GI/M was more effective than M alone. GI/M should be considered low-cost end-of-life palliative care for dyspnea.

[The application of hospice palliative care on discharge planning for the terminal cancer patient]

Whole person, family-centered, continued care, and multidisciplinary approach were four core values of hospice palliative care applied in this paper to assist in the difficult processes of discharging terminal cancer patients from the hospital and providing continued care until their peaceful death. Reasons underlying difficulties with discharges identified during hospitalizations between July 5th to 25th 2007 include: 1. 'whole person' aspects, including lack of confidence with the discharge on the part of the patient and his / her families due to inadequate symptoms control and loneliness due to lack of caregiver understanding and support; 2. 'family-centered' aspects, including failure to designate a key decision maker, differences of opinions, and overwhelming caregiver burdens; 3. 'continuity of care' aspects, including lack of appropriate and continuing palliative care and 4. 'multidisciplinary approach' aspects, including factitious relationships among patient, family members, and healthcare providers due to lack of trust. Furthermore, the healthcare team mapped out individual and continued care plans as follows: 1. 'whole person' aspects should focus on symptom control, enhancing comfort, and encouraging emotional expression; 2. 'family-centered' care aspects should identify the key person and significant others, decrease caregiver burdens, provide essential assistance and conduct family conferences; 3. 'continuity care' aspects should include consulting hospice home care and bereavement care professionals; 4. 'multidisciplinary approach' aspects should address comprehensive care so that team members learn from and reflect on their experiences. Ultimately, patients were successfully discharged from the hospital and peacefully passed away one week afterward. The writer hopes this nursing experience will provide a valuable reference for clinical practice to develop a family-centered approach to palliative care based on the four core values of hospice palliative care and the multidisciplinary discharge plan for terminal cancer patients.

[A nursing experience of holistic care on total suffering of a patient with terminal illness]

The purpose of this article was to describe a nursing experience using holistic care to relieve total suffering resulting from complex interactions amongst physical, psychological, social and spiritual aspects in a patient with terminal illness. Each aspect of problems was identified by means of direct participant care, observation, empathetic communication and holistic assessment. Such included: (1) physical aspect: distress caused by pain, nausea, vomiting and poor intake, infection and hypercalcaemia; (2) psychosocial aspect: caregiver's overwhelming burdens and financial concerns; (3) spiritual aspect: yearn for being with a higher-being and receiving unconditional love, pursuit of the meaning of suffering, proceed to the next stage to develop a unique care plan and nursing intervention program. Nursing goals were set up based on the patient's "life expectancy" represented by the hope for a painless and peaceful death. The author helped to provide unique, holistic and continued care for the purpose of humanity. The main nursing interventions included active control of symptoms, encouraging the expression of emotional distress, caring and emotional resonance with caregiver's overwhelming burdens, reconciling with a higher being through art therapy, pursuit of the meaning of suffering and sharing the darkness. This nursing experience of holistic care may be shared with other healthcare professionals and has been recorded as a positive response to the following quote from Dame Cicely Saunders: "The way care is given can reach the most hidden places and give space for unexpected development."

A new siglec family member, siglec-10, is expressed in cells of the immune system and has signaling properties similar to CD33

The siglecs (sialic acid-binding Ig-like lectins) are a distinct subset of the Ig superfamily with adhesion-molecule-like structure. We describe here a novel member of the siglec protein family that shares a similar structure including five Ig-like domains, a transmembrane domain, and a cytoplasmic tail containing two ITIM-signaling motifs. Siglec-10 was identified through database mining of an asthmatic eosinophil EST library. Using the Stanford G3 radiation hybrid panel we were able to localize the genomic sequence of siglec-10 within the cluster of genes on chromosome 19q13.3-4 that encode other siglec family members. We have demonstrated that siglec-10 is an immune system-restricted membrane-bound protein that is highly expressed in peripheral blood leukocytes as demonstrated by Northern, RT-PCR and flow cytometry. Binding assays determined that the extracellular domain of siglec-10 was capable of binding to peripheral blood leukocytes. The cytoplasmic tail of siglec-10 contains four tyrosines, two of which are embedded in ITIM-signaling motifs (Y597 and Y667) and are likely involved in intracellular signaling. The ability of tyrosine kinases to phosphorylate the cytoplasmic tyrosines was evaluated by kinase assay using wild-type siglec-10 cytoplasmic domain and Y-->F mutants. The majority of the phosphorylation could be attributed to Y597 andY667. Further experiments with cell extracts suggest that SHP-1 interacts with Y667 and SHP-2 interacts with Y667 in addition to another tyrosine. This is very similar to CD33, which also binds the phosphatases SHP-1 and SHP-2, therefore siglec-10, as CD33, may be characterized as an inhibitory receptor.

[Studies on the spectroscopic property of p-hydroxyphenol derivatives]

In the paper, properties of p-hydroxyphenol derivatives are described. The results prove that p-hydroxyphenol derivatives with different function groups show different spectroscopic properties. Some methods will be proposed to analyze a series of p-hydroxyphenol derivatives in blood or urine so as to identify the cancer mark.

Fast analysis of water samples for detection of anions by capillary zone electrophoresis

A capillary zone electrophoresis (CZE) method with relatively low separation voltage and short capillary length, using indirect UV detection was developed for the fast and quantitative determination of Cl-, NO2-, SO4(2-), NO3-, F- and HCO3- in potable water samples. Baseline separation of inorganic and organic anions was achieved within 1 min. The optimal carrier electrolyte consisted of 6.0 mM sodium chromate, 2.5 mM CTAB and 3.5% acetonitrile at pH 9.0. The effects of pH and the concentrations of electrolyte and flow modifiers on the resolution were investigated. Two injection methods, gravity and electrokinetic, were compared. The application of electrokinetic injection, using pyroglutamic acid as an internal standard was found to provide a method that is fast, sensitive and quantitative, with an R.S.D. for migration times from 0.1% to 0.3% and for peak areas from 1.8% to 4.1%. The limits of detection were 0.08 mg/L Cl-, 0.3 mg/L NO2-, 0.1 mg/L SO4(2-), 0.1 mg/L NO3-, 0.07 mg/L F-, and 0.3 mg/L HCO3-. This method has been successfully applied to determine Cl-, NO2-, SO4(2-), NO3-, F-, HCO3- in municipal water, surface water and bottled water samples.

A novel human hepatic organic anion transporting polypeptide (OATP2). Identification of a liver-specific human organic anion transporting polypeptide and identification of rat and human hydroxymethylglutaryl-CoA reductase inhibitor transporters

A novel human organic transporter, OATP2, has been identified that transports taurocholic acid, the adrenal androgen dehydroepiandrosterone sulfate, and thyroid hormone, as well as the hydroxymethylglutaryl-CoA reductase inhibitor, pravastatin. OATP2 is expressed exclusively in liver in contrast to all other known transporter subtypes that are found in both hepatic and nonhepatic tissues. OATP2 is considerably diverged from other family members, sharing only 42% sequence identity with the four other subtypes. Furthermore, unlike other subtypes, OATP2 did not transport digoxin or aldosterone. The rat isoform oatp1 was also shown to transport pravastatin, whereas other members of the OATP family, i.e. rat oatp2, human OATP, and the prostaglandin transporter, did not. Cis-inhibition studies indicate that both OATP2 and roatp1 also transport other statins including lovastatin, simvastatin, and atorvastatin. In summary, OATP2 is a novel organic anion transport protein that has overlapping but not identical substrate specificities with each of the other subtypes and, with its liver-specific expression, represents a functionally distinct OATP isoform. Furthermore, the identification of oatp1 and OATP2 as pravastatin transporters suggests that they are responsible for the hepatic uptake of this liver-specific hydroxymethylglutaryl-CoA reductase inhibitor in rat and man.

Functional expression of two KvLQT1-related potassium channels responsible for an inherited idiopathic epilepsy

Benign familial neonatal convulsions (BFNC), a class of idiopathic generalized epilepsy, is an autosomal dominantly inherited disorder of newborns. BFNC has been linked to mutations in two putative K+ channel genes, KCNQ2 and KCNQ3. Amino acid sequence comparison reveals that both genes share strong homology to KvLQT1, the potassium channel encoded by KCNQ1, which is responsible for over 50% of inherited long QT syndrome. Here we describe the cloning, functional expression, and characterization of K+ channels encoded by KCNQ2 and KCNQ3 cDNAs. Individually, expression of KCNQ2 or KCNQ3 in Xenopus oocytes elicits voltage-gated, rapidly activating K+-selective currents similar to KCNQ1. However, unlike KCNQ1, KCNQ2 and KCNQ3 currents are not augmented by coexpression with the KCNQ1 beta subunit, KCNE1 (minK, IsK). Northern blot analyses reveal that KCNQ2 and KCNQ3 exhibit similar expression patterns in different regions within the brain. Interestingly, coexpression of KCNQ2 and KCNQ3 results in a substantial synergistic increase in current amplitude. Coexpression of KCNE1 with the two channels strongly suppressed current amplitude and slowed kinetics of activation. The pharmacological and biophysical properties of the K+ currents observed in the coinjected oocytes differ somewhat from those observed after injecting either KCNQ2 or KCNQ3 by itself. The functional interaction between KCNQ2 and KCNQ3 provides a framework for understanding how mutations in either channel can cause a form of idiopathic generalized epilepsy.

Tyrosine 1101 of Tie2 is the major site of association of p85 and is required for activation of phosphatidylinositol 3-kinase and Akt

Tie2 is an endothelium-specific receptor tyrosine kinase that is required for both normal embryonic vascular development and tumor angiogenesis and is thought to play a role in vascular maintenance. However, the signaling pathways responsible for the function of Tie2 remain unknown. In this report, we demonstrate that the p85 subunit of phosphatidylinositol 3-kinase (PI3-kinase) associates with Tie2 and that this association confers functional lipid kinase activity. Mutation of tyrosine 1101 of Tie2 abrogated p85 association both in vitro and in vivo in yeast. Tie2 was found to activate PI3-kinase in vivo as demonstrated by direct measurement of increases in cellular phosphatidylinositol 3-phosphate and phosphatidylinositol 3, 4-bisphosphate, by plasma membrane translocation of a green fluorescent protein-Akt pleckstrin homology domain fusion protein, and by downstream activation of the Akt kinase. Activation of PI3-kinase was abrogated in these assays by mutation of Y1101 to phenylalanine, consistent with a requirement for this residue for p85 association with Tie2. These results suggest that activation of PI3-kinase and Akt may in part account for Tie2's role in both embryonic vascular development and pathologic angiogenesis, and they are consistent with a role for Tie2 in endothelial cell survival.

Genomic organization and expression of KCNJ8/Kir6.1, a gene encoding a subunit of an ATP-sensitive potassium channel

ATP-sensitive K+ (KATP) channels are implicated in the coupling of metabolic energy to membrane potential, thereby regulating many essential cell functions. Here, we demonstrate that a subunit of human KATP channel, KCNJ8/Kir6.1, is expressed preferentially in the human heart. Somatic cell-hybrid mapping and fluorescence in-situ hybridization (FISH) localize human KCNJ8 to the short arm of human chromosome 12, at 12p12. Partial characterization of the human Kir6. 1 gene demonstrates that there is one large intron in the coding region and at least two additional introns in the 5' untranslated region resulting in transcripts that have differential expression in human tissues examined. Our studies provide information on the complexity of the Kir6.1 transcript in the 5' UTR that may be useful for future investigations on the tissue-specific regulation and function of this KATP channel gene.

Dominant-negative KvLQT1 mutations underlie the LQT1 form of long QT syndrome

BACKGROUND

Mutations that map to the KvLQT1 gene on human chromosome 11 account for more than 50% of inherited long QT syndrome (LQTS). It has been discovered recently that the KvLQT1 and minK proteins functionally interact to generate a current with biophysical properties similar to I(Ks), the slowly activating delayed-rectifier cardiac potassium current. Since I(Ks) modulates the repolarization of cardiac action potentials it is reasonable to hypothesize that mutations in KvLQT1 reduce I(Ks), resulting in the prolongation of cardiac action potential duration.

METHODS AND RESULTS

We expressed LQTS-associated KvLQT1 mutants in Xenopus oocytes either individually or in combination with wild-type KvLQT1 or in combination with both wild-type KvLQT1 and minK. Substitutions of alanine with proline in the S2-S3 cytoplasmic loop (A177P) or threonine with isoleucine in the highly conserved signature sequence of the pore (T311I) yield inactive channels when expressed individually, whereas substitution of leucine with phenylalanine in the S5 transmembrane domain (L272F) yields a functional channel with reduced macroscopic conductance. However, all these mutants inhibit wild-type KvLQT1 currents in a dominant-negative fashion.

CONCLUSIONS

In LQTS-affected individuals these mutations would be predicted to result in a diminution of the cardiac I(Ks) current, subsequent prolongation of cardiac repolarization, and an increased risk of arrhythmias.

KvLQT1, a voltage-gated potassium channel responsible for human cardiac arrhythmias

The clinical features of long QT syndrome result from episodic life-threatening cardiac arrhythmias, specifically the polymorphic ventricular tachycardia torsades de pointes. KVLQT1 has been established as the human chromosome 11-linked gene responsible for more than 50% of inherited long QT syndrome. Here we describe the cloning of a full-length KVLQT1 cDNA and its functional expression. KVLQT1 encodes a 676-amino acid polypeptide with structural characteristics similar to voltage-gated potassium channels. Expression of KvLQT1 in Xenopus oocytes and in human embryonic kidney cells elicits a rapidly activating, K+-selective outward current. The I(Kr)-specific blockers, E-4031 and dofetilide, do not inhibit KvLQT1, whereas clofilium, a class III antiarrhythmic agent with the propensity to induce torsades de pointes, substantially inhibits the current. Elevation of cAMP levels in oocytes nearly doubles the amplitude of KvLQT1 currents. Coexpression of minK with KvLQT1 results in a conductance with pharmacological and biophysical properties more similar to I(Ks) than other known delayed rectifier K+ currents in the heart.

In vitro antigen challenge of human antibody libraries for vaccine evaluation: the human immunodeficiency virus type 1 envelope

Human antibody responses, or versions thereof, can be cloned as phage display libraries. In vaccine evaluation, the possibility therefore exists of challenging the human response in vitro, rather than in vivo, in order to assist in establishing the most promising vaccine leads. The characteristics of the antibodies retrieved directly indicate the strengths and weaknesses of the vaccine at the molecular level. We applied this approach to compare recombinant and native human immunodeficiency virus type 1 envelope preparations. We conclude that recombinant gp160, gp140, and, to a lesser extent, gp120 present epitopes around the CD4 binding site in a conformation different from that of the native multimer and contrary to expected vaccine requirements. Antibodies to the potently neutralizing b12 epitope were selected preferentially from an immune library by purified human immunodeficiency virus type 1 virions. This suggests that b12 is a major epitope on the virions, in contrast to recombinant envelope preparations, in which related, weakly neutralizing epitopes predominate. Although the majority of virions in the preparation used are expected to be noninfective, it appears that they predominantly express a native envelope configuration and would be able to elicit potent neutralizing antibodies.

Effect of C-peptide administration on whole body glucose utilization in STZ-induced diabetic rats

Recent studies suggest that C-peptide stimulates glucose transport in isolated skeletal muscle. In order to determine the effect of C-peptide on whole body glucose utilization, streptozotocin (60 mg kg-1) (STZ)-induced diabetic and normal rats were studied using the euglycaemic clamp procedure and continuous infusion of somatostatin (1.0 micrograms kg-1 min-1) in pentobarbital-anaesthetized rats. Plasma insulin levels during the 6.0- and 30.0-mU kg-1 min-1 insulin infusions rose to 70-90 microU mL-1 and 500-700 microU mL-1, respectively. Blood glucose concentrations were clamped at 7.5-7.9 mmol L-1 in the diabetic rats and at basal levels or 7.7 mmol L-1 in the non-diabetic (normal) rats. Biosynthetic human C-peptide (0.5 nmol kg-1 min-1) was infused in 12 diabetic and 11 normal rats, resulting in concentrations of 26-41 nmol L-1. The metabolic clearance rate of glucose (MCR) for the diabetic rats receiving C-peptide (12.0 +/- 1.0 mL kg-1 min-1) was significantly (P < 0.01) higher than that in the diabetic rats given saline (6.3 +/- 0.7 mL kg-1 min-1) or a randomly scrambled C-peptide (7.8 +/- 1.3 mL kg-1 min-1) at low-dose insulin infusion but not at the high-dose insulin infusion. In normal rats C-peptide did not significantly increase the MCR for glucose. These results thus demonstrate that C-peptide has the capacity to increase glucose utilization in STZ-induced diabetic rats.

CDR walking mutagenesis for the affinity maturation of a potent human anti-HIV-1 antibody into the picomolar range

We describe the investigation of methodologies for the creation of very high affinity human antibodies. The high affinity human antibody b4/12 was optimized for its affinity to the human envelope glycoprotein gp120 of human immunodeficiency virus type 1 (HIV-1). Five libraries of b4/12 were constructed by saturation mutagenesis of complementarity-determining regions (CDRs). Libraries of antibody Fab fragments were displayed on the surface of filamentous phage and selected in vitro for binding to immobilized gp120. Sequential and parallel optimization strategies of CDRs were examined. The sequential CDR walking strategy consistently yielded b4/12 variants of improved affinity in each of the four different optimization sequences examined. This resulted in a 96-fold improvement in affinity. Additivity effects in the antibody combining site were explored by combining independently optimized CDRs in the parallel optimization strategy. Six variants containing optimized CDRs were constructed. Improvement of affinity based on additivity effects proved to be unpredictable but did lead to a modest improvement in affinity. Indeed, only one of the six combinations demonstrated additivity. The highest affinity Fab prepared using this strategy was improved 420-fold in affinity. The affinity of this Fab was 15 pM as compared to 6.3 nM for b4/12. Examination of the kinetics of Fab binding to gp120 revealed that improvements in affinity were dominated by a slowing of the off-rate of the Fab. The methodology presented here provides a route for the improvement of the affinities of antibodies typical of tertiary immune responses into the picomolar range. Such improvements may have profound effects on the utility of antibodies as therapeutic and prophylactic agents.

Functional expression of a vertebrate inwardly rectifying K+ channel in yeast

We describe the expression of gpIRK1, an inwardly rectifying K+ channel obtained from guinea pig cardiac cDNA. gpIRK1 is a homologue of the mouse IRK1 channel identified in macrophage cells. Expression of gpIRK1 in Xenopus oocytes produces inwardly rectifying K+ current, similar to the cardiac inward rectifier current IK1. This current is blocked by external Ba2+ and Cs+. Plasmids containing the gpIRK1 coding region under the transcriptional control of constitutive (PGK) or inducible (GAL) promoters were constructed for expression in Saccharomyces cerevisiae. Several observations suggest that gpIRK1 forms functional ion channels when expressed in yeast. gpIRK1 complements a trk1 delta trk2 delta strain, which is defective in potassium uptake. Expression of gpIRK1 in this mutant restores growth on low potassium media. Growth dependent on gpIRK1 is inhibited by external Cs+. The strain expressing gpIRK1 provides a versatile genetic system for studying the assembly and composition of inwardly rectifying K+ channels.

Two types of calcium channels in bullfrog saccular hair cells

Ca2+ channels were studied in cell-attached recordings from the basolateral membrane of the bullfrog saccular hair cells with the EPC-9 patch-clamp system. Pipettes contained 110 mM Ba2+ and the membrane potential was zeroed with isotonic potassium aspartate. Data acquisition and analysis were performed using E9SCREEN and M2LAB software. L-type channel was distinguished by a single-channel conductance of 26 pS, activation range between -10 and +40 mV and intense activity even at a holding potential of -40 mV. The L-type channel showed characteristic bursts of brief openings (mode 1) interrupted occasionally by longer openings (mode 2). Bay K 8644 promoted the mode 2 activity and nifedipine inhibited L-type channel activity. Another type of calcium channels, 20 pS channel, was detected by -50 to +10 mV depolarizing steps from a holding potential of -40 or -80 mV. This channel was insensitive to dihydropyridines and resembled the N-type channel.

Surface plasmon resonance based kinetic studies of zinc finger-DNA interactions

Libraries of the zinc finger DNA binding protein, Zif268, have been constructed and selected for affinity and specificity toward DNA targets using the phage display technique (Wu et al., 1995). Mutant proteins were purified to homogeneity and were characterized for their ability to interact with their DNA targets using a real-time biomolecular interaction assay (BIA). One mutant protein, C7, bound the Zif268 consensus binding sequence with a 13-fold increase in affinity as compared to the wild-type Zif268 protein. Mutant proteins with moderate affinity for new DNA targets within a consensus sequence of HIV-1 have also been obtained. Surface plasmon resonance based BIA has provided invaluable kinetic information which offers insights into the mechanism of protein-DNA interactions.

Human autoantibody recognition of DNA

Combinatorial IgG Fab phage display libraries prepared from a systemic lupus erythematosus (SLE) donor and a healthy donor were affinity selected against human placental DNA. Human monoclonal antibody Fab fragments specific for DNA were isolated from both libraries, although Fabs of the highest affinity were isolated only from the lupus library. Generally, apparent affinities of the Fabs for human placental DNA, purified double-stranded DNA, and denatured DNA were approximately equivalent. Surface plasmon resonance indicated Fab binding constants for a double-stranded oligodeoxynucleotide of 0.2-1.3 x 10(8) M-1. The higher-affinity Fabs, as ranked by binding to human placental DNA or to the oligonucleotide probe, tested positive in the Crithidia luciliae assay commonly used in the diagnosis of SLE, and interestingly the genes encoding the heavy-chain variable regions of these antibodies displayed evidence of only minimal somatic hypermutation. The heavy chains of the SLE Fabs were characterized by a predominance of basic residues toward the N terminus of complementarity-determining region 3 (CDR3). The crucial role of heavy-chain CDR3 (HCDR3) in high-affinity DNA recognition was suggested by the creation of DNA binding in an unrelated antibody by HCDR3 transplantation from SLE antibodies. We propose that high-affinity DNA-binding antibodies can arise in SLE without extensive somatic hypermutation in the variable-region genes because of the expression of inappropriate HCDR3s.

Effect of daily voluntary running on in vivo insulin action in rat skeletal muscle and adipose tissue as determined by the microdialysis technique

The effect of physical training on in vivo insulin-stimulated glucose utilization in relation to glycolysis (lactate formation) in rat peripheral tissues was investigated in 8 sedentary controls (SC) and 7 voluntary running rats (VR). We used a sequential euglycemic clamp procedure (insulin infusion rate; 6.0, 30.0 mU/kg.min) in combination with a microdialysis technique in M. quadriceps femoris, vastus lateralis, and inguinal adipose tissue. In the clamp study, glucose infusion rate (GIR) averaged over 45-75 min during the 6.0-mU/kg.min insulin infusion was significantly (p < 0.01) higher in VR (15.36 +/- 0.83 mg/kg.min, mean +/- SE) than in SC (10.41 +/- 0.88 mg/kg.min), and the lack of a significant difference in GIR between VR and SC was found during the 30.0-mU/kg.min insulin infusion. In these tissues, there was no significant difference in dialysate lactate levels between VR and SC in the basal state without insulin or glucose infusion, or at an insulin infusion rate of 30.0 mU/kg.min. However, dialysate lactate concentrations in muscle averaged over 45-75 min during the 6.0-mU/kg.min insulin clamp procedure in VR (8.51 +/- 0.71 mg/dl) were significantly (p < 0.05) higher than in SC (6.18 +/- 0.48 mg/dl). These results indicated that insulin action in skeletal muscle and adipose tissue could be evaluated in vivo by using the microdialysis technique, and that an increase in GIR in VR was, in part, explained by an increase in lactate formation in skeletal muscle.

Building zinc fingers by selection: toward a therapeutic application

A phage display approach was utilized to modify the specificity of each of the three fingers of the murine transcription factor Zif268. Selections were performed by using the consensus binding sequence of the natural protein and a conserved sequence in the genome of the type 1 human immunodeficiency virus. By using an extensive randomization strategy, the entire 3-bp specificity of a finger has been changed. Rapid analysis of selected zinc fingers was facilitated by the development of an immunoscreening assay for DNA binding and specificity. To investigate the mechanism of binding and specificity, the binding kinetics of Zif268 and 10 selected variants were determined in real time with an assay based on surface plasmon resonance. Differential mechanisms for sequence-specific recognition were observed. No evidence in support of a single general coding relationship between zinc finger and target DNA sequence was observed. The prospects for the development of this class of proteins in human therapy are considered.

Neutralizing recombinant human antibodies to a conformational V2- and CD4-binding site-sensitive epitope of HIV-1 gp120 isolated by using an epitope-masking procedure

As part of the goal of assembling a mixture of neutralizing human mAbs for possible prophylaxis and therapy of HIV-1 disease, we describe a strategy by which neutralizing human Abs to a weakly immunogenic epitope can be accessed. From a phage display library derived from an asymptomatic HIV-1 seropositive donor, a panel of recombinant Fabs against the CD4 binding site (CD4bs) of gp120 was retrieved by affinity selection using recombinant gp120 (strain LAI). Two Fabs corresponding to the dominant clones were used to mask the CD4bs epitope(s) before repeating the selection procedure. Four Fabs were then retrieved that had novel heavy chain sequences. Three recognized a novel epitope distinct from that recognized by conventional CD4bs Abs and were defined by the following criteria: 1) second V region (V2 region) dependence indicated by sensitivity to amino acid changes in the V2 loop and by competition with murine anti-V2 mAbs; 2) CD4bs dependence indicated by sensitivity to amino acid changes usually associated with CD4 binding and by inhibition of Fab binding to gp120 by soluble CD4; this dependence seemed to arise via conformational changes rather than by direct binding, as CD4bs Abs enhanced binding of two of the novel Fabs and, in a reversal of the competition format, the novel Fabs did not inhibit soluble CD4 binding to gp120; and 3) equivalent binding to glycosylated and deglycosylated gp120 and significant, although much reduced, binding to denatured gp120 in contrast with CD4bs Abs, which do not bind to deglycosylated or denatured gp120. One of the novel Fabs efficiently neutralized the MN and LAI strains of HIV-1. These results indicate the presence of a novel neutralizing conformational epitope on gp120 sensitive to the V2 loop and the CD4bs and further highlight the conformational flexibility of gp120. The strategy of masking highly immunogenic epitopes with Abs to rescue a broader range of specific Abs from combinatorial libraries should be widely applicable.

Neutralizing recombinant human antibodies to a conformational V2- and CD4-binding site-sensitive epitope of HIV-1 gp120 isolated by using an epitope-masking procedure

As part of the goal of assembling a mixture of neutralizing human mAbs for possible prophylaxis and therapy of HIV-1 disease, we describe a strategy by which neutralizing human Abs to a weakly immunogenic epitope can be accessed. From a phage display library derived from an asymptomatic HIV-1 seropositive donor, a panel of recombinant Fabs against the CD4 binding site (CD4bs) of gp120 was retrieved by affinity selection using recombinant gp120 (strain LAI). Two Fabs corresponding to the dominant clones were used to mask the CD4bs epitope(s) before repeating the selection procedure. Four Fabs were then retrieved that had novel heavy chain sequences. Three recognized a novel epitope distinct from that recognized by conventional CD4bs Abs and were defined by the following criteria: 1) second V region (V2 region) dependence indicated by sensitivity to amino acid changes in the V2 loop and by competition with murine anti-V2 mAbs; 2) CD4bs dependence indicated by sensitivity to amino acid changes usually associated with CD4 binding and by inhibition of Fab binding to gp120 by soluble CD4; this dependence seemed to arise via conformational changes rather than by direct binding, as CD4bs Abs enhanced binding of two of the novel Fabs and, in a reversal of the competition format, the novel Fabs did not inhibit soluble CD4 binding to gp120; and 3) equivalent binding to glycosylated and deglycosylated gp120 and significant, although much reduced, binding to denatured gp120 in contrast with CD4bs Abs, which do not bind to deglycosylated or denatured gp120. One of the novel Fabs efficiently neutralized the MN and LAI strains of HIV-1. These results indicate the presence of a novel neutralizing conformational epitope on gp120 sensitive to the V2 loop and the CD4bs and further highlight the conformational flexibility of gp120. The strategy of masking highly immunogenic epitopes with Abs to rescue a broader range of specific Abs from combinatorial libraries should be widely applicable.

Design and evaluation of a thrombin-activable plasminogen activator

A new chimeric plasminogen activator with high fibrin affinity was designed to bind fibrin and to initiate clot destruction, following activation by thrombin. The chimeric activator, 59D8-scuPA-T, was made from the Fab fragment of an anti-fibrin antibody (59D8) and a C-terminal portion of a thrombin-activable low molecular weight single-chain urokinase plasminogen activator, scuPA-T, obtained by deletion of Phe-157 and Lys-158 from low molecular weight single-chain urokinase-type plasminogen activator (scuPA) by site-directed mutagenesis. The chimeric molecule had a molecular mass of 91,000, a value consistent with one 59D8 light chain (M(r) = 27,000) and one 59D8 heavy-chain Fd fragment fused to low molecular weight scuPA (M(r) = 64,000). According to its design, 59D8-scuPA-T was activated by thrombin but not by plasmin, whereas the control chimeric molecule, 59D8-scuPA, was activated by plasmin but not by thrombin. When activated by thrombin, 59D8-scuPA-T converted plasminogen to plasmin. In vitro plasma clot lysis assays showed that 59D8-scuPA-T lysed clots performed by thrombin and that heparin and hirudin could prevent clot lysis. When incorporated as part of a thrombin-induced clot, only 59D8-scuPA-T was able to lyse the clot while 59D8-scuPA and high molecular weight scuPA were ineffective. Together these results demonstrate that 59D8-scuPA-T is a thrombin-activable plasminogen activator that offers selective thrombolysis of thrombin-rich clots over more established, aged clots, and may also act as an antithrombotic agent.

A point mutation in the chloroplast rps12 gene from Nicotiana plumbaginifolia confers streptomycin resistance

In an effort to understand the mechanism of streptomycin resistance in Nicotiana plumbaginifolia, we have sequenced the chloroplast rps12 gene, a potential molecular target. We report that a streptomycin-resistant mutant isolated from protoplast cultures of N. plumbaginifolia contains an A-to-G transition at nucleotide position 149 in exon 2 of the chloroplast rps12 gene. The detected point mutation predicts a substitution of arginine for lysine in a phylogenetically conserved region.

Phenotypic revertant mutations of a new OmpR2 mutant (V203Q) of Escherichia coli lie in the envZ gene, which encodes the OmpR kinase

The Escherichia coli ompR2 allele ompR472 contains a valine-to-methionine point mutation at position 203, resulting in an OmpF-constitutive OmpC- outer membrane phenotype. In the present study, OmpR residue V-203 was replaced with glutamine (V203Q mutation), resulting in the same outer membrane phenotype. However, unlike the OmpFc OmpC- phenotype conferred by the OmpR(V203M) mutant protein, the OmpFc OmpC- phenotype produced by the OmpR(V203Q) mutation was suppressed by the envZ11(T247R) allele. Additional suppressors of OmpR(V203Q) were isolated by random mutagenesis. All suppressor mutations were found in the envZ gene and conferred an OmpC+ OmpF- phenotype in the presence of the wild-type ompR. These envZ11-like mutations mapped to a region different from those previously reported and were incapable of suppressing the ompR(V203M) allele. Our results indicate that while methionine or glutamine replacements could cause similar effects on OmpF and OmpC expression, they conferred different abilities on the mutant proteins to be suppressed by envZ.