Fraxetin ameliorates symptoms of dextran sulphate sodium-induced colitis in mice

Ulcerative colitis (UC) is one of the primary inflammatory bowel diseases (IBDs) and causes a serious threat to human public health around the world. Currently, there are no proven safe and effective treatment options to treat UC. Fraxetin (Fxt) is a widely recognized antioxidant and anti-inflammatory legume derived from ash bark. In the present study, we investigated the protective effect and mechanism of Fxt on UC. Our results showed that Fxt significantly attenuated the body weight, colon length reduction, tissue damage, and disease activity index induced by dextran sodium sulphate (DSS). Moreover, the DSS-induced activation of the NF-κB pathway and NLRP3 inflammasomes was inhibited, and the inflammatory response was reduced. Fxt restored gut barrier function by increasing the number of goblet cells and the levels of tight junction proteins (ZO-1 and occludin). In addition, Fxt can alter the intestinal microbiota by enhancing the diversity of the microbiota, increasing the relative abundance of beneficial bacteria and inhibiting the growth of harmful bacteria. These results revealed that Fxt alleviates DSS-induced colitis by modulating the inflammatory response, enhancing epithelial barrier integrity and regulating the gut microbiota. This study may provide a scientific basis for the potential therapeutic effect of Fxt in the prevention of colitis and other related diseases.

Pathological observation and transcriptomic analysis of thymus injury in PRRSV-infected piglets

The thymus, the central immune organ in mammals, plays an important role in immune defense. Porcine reproductive and respiratory syndrome virus (PRRSV) infection in piglets can cause thymus injury and immunosuppression. However, the mechanisms of thymus injury remain unknown. This study was aimed at investigating the specific manifestations of thymus injury through the construction of a PRRSV-infected piglet model and histopathological observation. In this study, fourteen 40-day-old PRRSV-free piglets were randomly divided into two groups, eleven of which were intramuscularly injected with 3 mL of PRRSV WUH3 virus suspension (106 PFU /mL) in the infection group, and three of which were sham-inoculated with 3 mL of RPMI-1640 medium in the control group. Clinical necropsy and samples collection were performed on day 8 after artificial infection. With the Illumina platform, the transcriptomes of piglet thymus tissues from infected and control piglets were sequenced to explore the relationships of differentially expressed genes (DEGs) and signaling pathways with thymus injury. The immune organs of PRRSV-infected piglets were severely damaged. The histopathological findings in the thymus indicated that PRRSV infection was associated with a large decrease in lymphocytes, cell necrosis and cell apoptosis; an increase in blood vessels and macrophages; thymic corpuscle hyperplasia; and interstitial widening of the thymic lobules. The transcriptomic analysis results revealed that the Gene Ontology functions of DEGs were enriched primarily in biological processes such as angiogenesis, regulation of angiogenesis and positive regulation of cell migration. Moreover, greater numbers of blood vessels and macrophages were observed in the thymus in PRRSV-infected than control piglets. KEGG pathway enrichment analysis revealed that the DEGs were significantly enriched in the Toll-like receptor signaling pathway, chemokine signaling pathway, IL-17 signaling pathway and TNF signaling pathway. The expression of TLR8, IRF5, the chemokines CCL2, CCL3L1 and CCL5; and their receptors CCR1, CCR2 and CCR5 was significantly up-regulated in PRRSV infection, thus suggesting that these cytokines were associated with the pathological processes of thymus injury.

Microglia play an important role in PRV infection-induced immune responses of the central nervous system

Pseudorabies virus (PRV) can infect multiple hosts and lead to fatal encephalitis. There is a significant increase in the number of microglia in the brain of animals infected with PRV. However, whether and how microglia contribute to central nervous system damage in PRV infection remain unknown. In the present study, we elucidated that PRV infection can cause more severe inflammatory cell infiltration, thicker and more numerous vessel sleeve walls, and more severe inflammatory responses in the brains of natural hosts (pigs) than in those of nonnatural hosts (mice). In a mice infection model, activated microglia restricted viral replication in the early stage of infection. Acute neuroinflammation caused by microglia hyperactivation at late-stage of infection. Furthermore, in vitro experiments revealed that microglia restricted viral replication and decreased viral infectivity. This may be associated with the phagocytic ability of microglia because we observed a significant increase in the expression of the membrane receptor TREM2 in microglia, which is closely related to phagocytosis, we observed that depletion of microglia exacerbated neurological symptoms, blood-brain barrier breakdown, and peripheral lymphocyte infiltration. Taken together, we revealed the dual role of microglia in protecting the host and neurons from PRV infection.

A hybrid approach for low-carbon transportation system analysis: integrating CRITIC-DEMATEL and deep learning features

As supply chains, logistics, and transportation activities continue to play a significant role in China's economic and social developments, concerns around energy consumption and carbon emissions are becoming increasingly prevalent. In light of sustainable development goals and the trend toward sustainable or green transportation, there is a need to minimize the environmental impact of these activities. To address this need, the government of China has made efforts to promote low-carbon transportation systems. This study aims to assess the development of low-carbon transportation systems in a case study in China using a hybrid approach based on the Criteria Importance Through Intercriteria Correlation (CRITIC), Decision-Making Trial and Evaluation Laboratory (DEMATEL) and deep learning features. The proposed method provides an accurate quantitative assessment of low-carbon transportation development levels, identifies the key influencing factors, and sorts out the inner connection among the factors. The CRITIC weight matrix is used to obtain the weight ratio, reducing the subjective color of the DEMATEL method. The weighting results are then corrected using an artificial neural network to make the weighting more accurate and objective. To validate our hybrid method, a numerical example in China is applied, and sensitivity analysis is conducted to show the impact of our main parameters and analyze the efficiency of our hybrid method. Overall, the proposed approach offers a novel method for assessing low-carbon transportation development and identifying key factors in China. The results of this study can be used to inform policy and decision-making to promote sustainable transportation systems in China and beyond.

FAM83A promotes the progression and metastasis of human pancreatic neuroendocrine tumors by inducing the epithelial-mesenchymal transition via the PI3K/AKT and ERK pathways

PURPOSE

Family with sequence similarity 83, member A (FAM83A) has been reported to play an important role in cancer progression and metastasis. The purpose of this study was to clarify the role and mechanism of FAM83A in pancreatic neuroendocrine tumors (PanNETs).

METHODS

PanNET specimens and adjacent nontumor pancreatic tissues obtained from 68 patients who underwent curative surgery for PanNETs were assessed for FAM83A expression using immunochemical staining. The relationships between FAM83A expression, clinicopathological parameters and prognosis were statistically analyzed. PanNET cell lines were used to study the role of FAM83A in the progression and metastasis of PanNETs in vitro and in vivo.

RESULTS

FAM83A was overexpressed in PanNET specimens compared with adjacent nontumor tissues. Furthermore, FAM83A expression was closely associated with lymph node metastasis (P = 0.02), perineural invasion (P = 0.001), WHO classification (P = 0.039), AJCC stage (P = 0.01) and shorter disease-free survival in patients with PanNETs (P < 0.001). FAM83A overexpression effectively promoted PanNET cell proliferation, migration, invasion and growth both in vitro and in vivo, whereas FAM83A inhibition exerted the opposite effects. Subsequent mechanistic investigations revealed that FAM83A promotes the progression and metastasis of PanNETs by inducing epithelial-mesenchymal transition (EMT) via the PI3K/AKT and ERK pathways.

CONCLUSIONS

FAM83A plays an important role in the progression and metastasis of PanNET by inducing the EMT via the activation of the ERK and PI3K/AKT pathways and may serve as a valuable molecular target in PanNET treatment.

Dental nerves: a neglected mediator of pulpitis

As one of the most densely innervated tissues, the dental pulp contains abundant nerve fibres, including sensory, sympathetic and parasympathetic nerve fibres. Studies in animal models and human patients with pulpitis have revealed distinct alterations in protein expression and histological appearance in all types of dental nerve fibres. Various molecules secreted by neurons, such as classical neurotransmitters, neuropeptides and amino acids, not only contribute to the induction, sensitization and maintenance of tooth pain, but also regulate non-neuronal cells, including fibroblasts, odontoblasts, immune cells and vascular endothelial cells. Dental nerves are particularly important for the microcirculatory and immune responses in pulpitis via their release of a variety of functional substances. Further, nerve fibres are found to be involved in dental soft and hard tissue repair. Thus, understanding how dental nerves participate in pulpitis could have important clinical ramifications for endodontic treatment. In this review, the roles of dental nerves in regulating pulpal inflammatory processes are highlighted and their implications for future research on this topic are discussed.

How many lymph nodes should be dissected in esophagectomy with or without neoadjuvant therapy to get accurate staging?

It is essential to dissect an adequate number of lymph nodes (LNs) to ensure staging accuracy during esophagectomy with or without neoadjuvant therapy. We developed a statistical model to quantify the probability of precise nodal staging based on previous studies. Esophageal cancer patients who underwent esophagectomy were retrospectively reviewed in the Surveillance, Epidemiology, and End Results database. A β-binomial distribution was adopted to estimate the number of understaged patients based on the numbers of positive and examined LNs. Using 6,252 patients, we estimated a 90% confidence of accurate N0 staging could be achieved by examining 17 LNs without neoadjuvant therapy. To obtain similar accuracy in N1 and N2, 20 and 25 LNs should be examined. For patients with neoadjuvant therapy, 18, 19, and 28 LNs could achieve the same accuracy. Staging accuracy was a significant prognostic factor. We found when 90% confidence had been achieved, patient survival did not improve with more LNs examined and the ratio and log odds of positive LNs did not have significant prognostic values. The statistical model we developed for precise staging in patients with different N stages is of great value in guiding lymphadenectomy. It provided risk assessment for underestimated LN metastases and guided subsequent adjuvant treatment.

Landscape of expression profiles in esophageal carcinoma by The Cancer Genome Atlas data

In this study, we explored the gene and microRNA (miRNA) expressions profile of esophageal carcinoma. The expression data for messenger RNAs and miRNAs in normal and cancerous esophageal tissues were obtained from the Cancer Genome Atlas database and then the differentially expressed genes and miRNAs were identified. As a result, we identified 2962 genes and 45 miRNAs differentially expressed in esophageal carcinoma compared with normal esophageal tissues. Subsequently, the altered gene functions and signaling pathways were investigated using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, and these differentially expressed genes were significantly enriched in the cell cycle, cell migration, mitogen-activated protein kinase (MAPK) and toll-like receptor signaling pathway, and so on. Then the regulatory relationships between the differentially expressed miRNAs and genes were examined with Targetscan and Miranda, and the potential target sites of transcription factors (TFs) in the promoter regions of these miRNAs and genes were identified using the TRANSFAC database. Finally the TF-miRNA-gene network in esophageal cancer was established, summarizing the regulatory links among the TFs, differentially expressed miRNAs and differentially expressed genes. Factors such as core promoter-binding protein (CPBP), nuclear factor of activated T-cells 1 (NFAT-1), miR-30c-5p, were located in the central hub of this network, highlighting their vital roles in esophageal tumorigenesis. These findings may extend our understanding of the molecular mechanisms underlying esophageal carcinoma and promote new perspectives for prevention, diagnosis and treatment.

Analysis report for osteosarcoma expression profile

BACKGROUND

Osteosarcoma is a kind of highly malignant primary bone tumor which most common in the teenage, and holds strong aggressive, earlier organs metastases mainly to lung, prone to postoperative recur. Therefore for osteosarcoma, invasion and transfer mechanism and related factors' interaction remains to be a key research subject.

AIM

We aim to find biological molecules marker can be used for osteosarcoma diagnosis through contrast of osteosarcoma sample and normal tissue samples.

MATERIALS AND METHODS

This analysis using human osteosarcoma expression profile data and three lesions normal tissue samples (liver, kidneys, lymph) expression data and compare them, and find significant specifically expressed genes, according to their function.

RESULTS

Research shows that the cancer cell proliferation, invasion, transfer and recurrent process involve many factors interaction, of which angiogenesis is the necessary condition of tumor growth, transfer and the recurrence.

CONCLUSIONS

Now the most important positive regulatory factor of angiogenesis is VEGF (vascular endothelial growth factor) and bFGF (basic fibroblast growth factor). Both of them are with a wide variety and close relationship of tumor angiogenesis and progress.

Pyruvate kinase M2 is highly correlated with the differentiation and the prognosis of esophageal squamous cell cancer

It's frequently stated that the pyruvate kinase M2 (PKM2) and Warburg effect are important for cancer development by accumulating more raw materials for macromolecule biosynthesis. However, the correlation between PKM2 and cancer is poorly reported. Here, we investigated the PKM2 expression in esophageal squamous cell cancer (ESCC). We observed that the expression of PKM2 was much higher in ESCC than in control normal tissue, and it is highly associated with many clinical features and prognosis. Specially, we found that the expression of PKM2 was closely related to the differentiation state of ESCC, and we further confirmed this discovery in vitro. As a result, out data indicated that PKM2 might be a useful indicator for determining the survival of patients with ESCC. Considering previous researches on the link among PKM2, Warburg effect, and differentiation, our study inferred the direct roles of PKM2 and Warburg effect in the differentiation of cancer cells rather than only providing synthetic intermediates for the promotion of cancer's progression.

Administrative data based patient safety research: a critical review

Administrative data are readily available, inexpensive, computer readable, and cover large populations. Despite coding irregularities and limited clinical details, administrative data supplemented by tools such as the Agency for Healthcare Research and Quality (AHRQ) patient safety indicators (PSIs) could serve as a screen for potential patient safety problems that merit further investigation, offer valuable insights into adverse impacts and risks of medical errors and, to some extent, provide benchmarks for tracking progress in patient safety efforts at local, state, or national levels.

Potentially inappropriate medication use in the community-dwelling elderly: findings from the 1996 Medical Expenditure Panel Survey

CONTEXT

Inappropriate medication use is a major patient safety concern, especially for the elderly population. Using explicit criteria, prior studies have found that 23.5% and 17.5% of the US community-dwelling elderly population used at least 1 of 20 potentially inappropriate medications in 1987 and 1992, respectively.

OBJECTIVES

To determine the prevalence of potentially inappropriate medication use in community-dwelling elderly persons in 1996, to assess trends over 10 years, categorize inappropriate medication use according to explicit criteria, and to examine risk factors for inappropriate medication use.

DESIGN, SETTING, AND PARTICIPANTS

Respondents aged 65 years or older (n = 2455) to the 1996 Medical Expenditure Panel Survey, a nationally representative survey of the US noninstitutionalized population were included. A 7-member expert panel was convened to categorize inappropriate medications.

MAIN OUTCOME MEASURE

Prevalence of use of 33 potentially inappropriate medications.

RESULTS

In 1996, 21.3% (95% confidence interval [CI], 19.5%-23.1%) of community-dwelling elderly patients in the United States received at least 1 of 33 potentially inappropriate medications. Using the expert panel's classifications, about 2.6% of elderly patients (95% CI, 2.0%-3.2%) used at least 1 of the 11 medications that should always be avoided by elderly patients; 9.1% (95% CI, 7.9%-10.3%) used at least 1 of the 8 that would rarely be appropriate; and 13.3% (95% CI, 11.7%-14.9%) used at least 1 of the 14 medications that have some indications but are often misused. Use of some inappropriate medications declined between 1987 and 1996. Persons with poor health and more prescriptions had a significantly higher risk of inappropriate medication use.

CONCLUSIONS

Overall inappropriate medication use in elderly patients remains a serious problem. Despite challenges in using explicit criteria for assessing inappropriate medications for elderly patients, such criteria can be applied to population-based surveys to identify opportunities to improve quality of care and patient safety. Enhancements of existing data sources to include dosage, duration, and indication may augment national improvement and monitoring efforts.

Patient Safety Indicators: using administrative data to identify potential patient safety concerns

OBJECTIVE

To develop Patient Safety Indicators (PSI) to identify potential in-hospital patient safety problems for the purpose of quality improvement.

DATA SOURCE/STUDY DESIGN

The data source was 2,400,000 discharge records in the 1997 New York State Inpatient Database. PSI algorithms were developed using systematic literature reviews of indicators and hand searches of the ICD-9-CM code book. The prevalence of PSI events and associations between PSI events and patient-level and hospital-level characteristics, length of stay, in-hospital mortality, and hospital charges were examined.

PRINCIPAL FINDINGS

PSIs were developed for 12 distinct clinical situations and an overall summary measure. The 1997 event rates per 10,000 discharges varied from 1.1 for foreign bodies left during procedure to 84.7 for birth traumas. Discharge records with PSI events had twofold to threefold longer hospital stays, twofold to 20-fold higher rates of in-hospital mortality, and twofold to eightfold higher total charges than records without PSI events. Multivariate logistic regression revealed that PSI events were primarily associated with increasing age (p < .001), hospitals performing more inpatient surgery (p < .001), and hospitals with higher percentage of beds in intensive care units (p < .001).

CONCLUSIONS

The PSIs provide an efficient and user-friendly tool to identify potential inhospital patient safety problems for targeted institution-level quality improvement efforts. Until better error-reporting systems are developed the PSIs can serve to shed light on the problem of medical errors not limited solely to mortality because of errors.

Induction of antibodies against GM2 ganglioside by immunizing melanoma patients using GM2-keyhole limpet hemocyanin + QS21 vaccine: a dose-response study

In a previous randomized Phase III trial (P. O. Livingston et al, J. Clin. Oncol., 12: 1036-1044, 1994), we demonstrated that immunization with GM2 and bacille Calmette-Guerin reduced the risk of relapse in stage III melanoma patients who were free of disease after surgical resection and who had no preexisting anti-GM2 antibodies. That vaccine formulation induced IgM anti-GM2 antibodies in 74% but induced IgG anti-GM2 antibodies in only 10% of the patients. To optimize the immune response against GM2, a reformulated vaccine was produced conjugating GM2 to keyhole limpet hemocyanin (KLH) and using the adjuvant QS21 (GM2-KLH/QS21). In pilot studies, 70 microg of vaccine induced IgG anti-GM2 antibodies in 76% of the patients. We wished to define the lowest vaccine dose that induced consistent, high-titer IgM and IgG antibodies against GM2. Fifty-two melanoma patients who were free of disease after resection but at high risk for relapse were immunized with GM2-KLH/QS21 vaccine at GM2 doses of 1, 3, 10, 30, or 70 ILg on weeks 1, 2, 3, 4, 12, 24, and 36. Serum collected at frequent and defined intervals was tested for anti-GM2 antibodies. Overall, 88% of the patients developed IgM anti-GM2 antibodies; 71% also developed IgG anti-GM2 antibodies. GM2-KLH doses of 3-70 microg seemed to be equivalent in terms of peak titers and induction of anti-GM2 antibodies. At the 30-microg dose level, 50% of the patients developed complement fixing anti-GM2 antibodies detectable at a serum dilution of 1:10. We conclude that the GM2-KLH/QS21 formulation is more immunogenic than our previous formulation and that 3 microg is the lowest dose that induces consistent, high-titer IgM and IgG antibodies against GM2.

Economic assessment of the community-acquired pneumonia intervention trial employing levofloxacin

OBJECTIVE

The purpose of this study was to assess use of a critical pathway designed to manage community-acquired pneumonia more efficiently than its management with conventional therapy.

METHODS

Economic outcomes were assessed in conjunction with a cluster-design, randomized, controlled trial. Nineteen participating Canadian hospitals were randomized to implement the critical pathway (n = 9) or conventional therapy (n = 10). The critical pathway included a clinical prediction rule to guide the admission decision, treatment with levofloxacin, and practice guidelines. Patient data on medical resource use, lost productivity, and quality of life were collected prospectively for > or =6 weeks after treatment. Costs were calculated from the government, health care system, and societal perspectives, with imputation of missing outpatient costs and the costs of lost productivity when necessary. Bootstrapping was used to identify 95% CIs for the total cost per patient.

RESULTS

The analysis included all eligible patients in the critical pathway (n = 716) and conventional therapy (n = 1027) arms. There were fewer hospital admissions in the critical pathway arm than in the conventional therapy arm, both overall (46.5% vs 62.2%; P = 0.01) and in low-risk patients (33.2% vs 46.8%; P < 0.001). Compared with conventional therapy, hospitals in the critical pathway arm had 1.6 fewer bed days per patient managed (P = 0.05) and used fewer inpatient medical resources. The 2 study arms had similar outpatient, readmission, and lost-productivity costs, and similar quality-of-life outcomes. The critical pathway produced cost savings from all 3 perspectives that ranged from $457 to $994 per patient.

CONCLUSIONS

The critical pathway employing levofloxacin resulted in cost savings compared with conventional therapy and did not compromise health outcomes.

[Study on the psychological status of video display terminal operator]

Occupational psychological test designed by the Labour Hygiene Department of West China University of Medical Sciences was applied to survey the mental health of 516 video display terminal (VDT) workers and 396 control workers in Chengdu. The results showed that mental health level of VDT workers was higher than that of controls. In the somatic disorder, anxious and hostile are increased obviously. With the prolonging of operating hours per week, somatic disorders, depression and obsession are increased, especially when VDT operating time is more than 30 hours per week and operating on VDT is more than ten years. This indicates that the operating hours should not be more than 30 hours per week. It is found by multiple factors analysis of data that the main adverse effects on mental health are age and VDT operating time.

[Study on the relationship between occupational factors and work ability of middle aged workers]

Based on the assessment of work ability index (WAI) of middle aged workers, associations between occupational factors and work ability decline of middle aged workers were examined in a case-control study. 1037 workers (age ranged from 40 to 60) were included in the study. The study group comprised 180 workers of mean age 47.71 years representing those who's work ability decreased. The control group comprised 857 workers of mean age 47.22 years representing those who's work ability was on a normal level. Results showed that some common occupation hazards such as dusts, noise, vibration, humidity, and high temperature were more frequently occurred in work environment of the study group than that of the control group. High risks were found in workers with these hazards. Another significant risk factor of work ability decline was heavy physical load. Significantly elevated risks were observed for physical load perception(OR = 2.52), repetitive work (OR = 1.36), poor work postures(OR = 1.48), and carrying heavy loads(OR = 1.59). As compared to physical loads, mental loads were not in relation to work ability decline. The information about occupational factors affecting work ability will be helpful for redesiging the work for the middle aged workers.

[Experimental study on the effect of abstinence with herbal preparation qingjunyin]

The effect of herbal preparation Qingjunyin (QJY) on the animal model of drug dependence was studied. After the morphinistic models of white rats and mice were made by ever increasing doses of morphine each time, the animals were divided into large dosage QJY group, small dosage QJY group, sustained morphine group and control group. The withdrawal symptoms were observed after naloxone was given to the animals intraperitoneally. The results showed that QJY groups withdrawal symptoms of the addicted white rats were alleviated, the number of jumps of the addicted mice was reduced, the scores of the principal symptoms of the animals were decreased, while the body weights of the animals were gained, comparing with the control group, the difference was significant (P < 0.01). The effects of QJY enhanced in the large dosage group, which suggests QJY has abstinence effects.

[Effect of different Anti-G suits on lower limb blood flow]

To study effects of different Anti-G suits (AGS) and different inflation pressure on human cardiac system, changes in lower limb arterial blood flow (BF), heart rate and blood pressure in 5 male subjects with three bladder coverage AGS and a capstain AGS were observed and recorded until inflation pressure reached to its maximum. The percent of bladder coverage was about 30%, 65% and 90% of lower body for three bladder AGS. All AGS were inflated to maximum pressure in +1Gz seating position. The results showed that calf BF, could be blocked by bladder AGS, and the relationship between the mean pressure for BF block and the percentage of bladder coverage was y = 29.66 - 16.35x. (P < 0.0001, r = -0.9229). While the thigh and calf BF was not blocked in subjects with the capsule AGS. The results indicate that the effect of "the higher bladder coverage AGS + lower IP" is probably equal to that of "the lower bladder coverage AGS + higher IP" in holding calf BF.

[Clinial study of "qingjunyin" detoxification for the treatment of heroin addicts]

To evaluate the efficacy of treatment of heroin addicts (n = 100) by "Qingjunyin" (QJY) detoxification (10 days program). Methadone detoxification (10 days program) group (n = 50) and colonidine treated group (n = 50) serve as controls. QJY group is given 180 ml P. O daily. The dosage of the two comparatine groups is given according to Documentation, the method of abserving the treatment protocols and detoxification standard is according to current regulation. The scores of abstinence syndrome in QJY detoxification group are lower than those in colonidine treated group in the first three days of potocol, but this difference disappear in the late stage of treatment. While QJY detoxification is effective as methadone detoxification in the control of abstinece syndrome during the first five days of treatment but the difference in the scores of abstinence syndrome between QJY and methadone group is observed during the late five days of protocol. QJY does not result in potential dependence and has definite curative effect in the treatment of heroin addiction.

[Changes of superoxide dismutase and lipid peroxide in lung tissue of rats after intratracheal injection of crocidolite and benzo(a) pyrene]

Wistar rats were divided into 4 groups: control group, Cro group, B(a) p group and Cro plus B(a) p group. Samples of lung tissue were collected 90, 180, 270, 360 and 540 days after the third time of intratracheal. The superoxide dismutase (SOD) activity, the level of lipid peroxide (LPO) and the ratio of SOD/LPO were observed. The results indicated that there was a synergistic action of Cro. and B(a) p.

Crystallization and preliminary X-ray diffraction studies of recombinant staphylokinase

Staphylokinase, a fibrin-specific plasminogen activator, was highly expressed in Escherichia coli and purified by ion-exchange and gel-filtration chromatography. The purified recombinant staphylokinase was fully active and readily crystallized against 1.2 M sodium citrate in 100 mM Tris-HCl buffer at pH 8.0 using the hanging-drop method. Crystals of staphylokinase diffract to better than 2.2 A resolution. The crystal belongs to the tetragonal space group P4(1)2(1)2 or its enantiomorph with unit-cell parameters a = b = 67.5, c = 150.1 A. There are two molecules in the asymmetric unit. In this paper, we described the first crystallization of a kind of plasminogen activator and present the results of preliminary X-ray diffraction data from the native protein.

The effects of hospital-physician integration strategies on hospital financial performance

STUDY QUESTION

This study investigated the longitudinal relations between hospital financial performance outcomes and three hospital-physician integration strategies: physician involvement in hospital governance, hospital ownership by physicians, and the integration of hospital-physician financial relationships.

DATA SOURCES AND STUDY SETTING

Using secondary data from the State of California, integration strategies in approximately 300 California short-term acute care hospitals were tracked over a ten-year period (1981-1990).

STUDY DESIGN

The study used an archival design. Hospital performance was measured on three dimensions: operational profitability, occupancy, and costs. Thirteen control variables were used in the analyses: market competition, affluence, and rurality; hospital ownership; teaching costs and intensity; multihospital system membership; hospital size; outpatient service mix; patient volume case mix; Medicare and Medicaid intensity; and managed care intensity.

DATA COLLECTION/EXTRACTION

Financial and utilization data were obtained from the State of California, which requires annual hospital reports. A series of longitudinal regressions tested the hypotheses.

PRINCIPAL FINDINGS

Considerable variation was found in the popularity of the three strategies and their ability to predict hospital performance outcomes. Physician involvement in hospital governance increased modestly from 1981-1990, while ownership and financial integration declined significantly. Physician governance was associated with greater occupancy and higher operating margins, while financial integration was related to lower hospital operating costs. Direct physician ownership, particularly in small hospitals, was associated with lower operating margins and higher costs. Subsample analyses indicate that implementation of the Medicare prospective payment system in 1983 had a major impact on these relationships, especially on the benefits of financial integration.

CONCLUSIONS

The findings support the validity of hospital-physician financial integration efforts, and to a lesser extent the involvement of physicians in hospital governance. The results lend considerably less support for strategies built around direct physician ownership in hospitals, particularly since PPS implementation.

RELEVANCE/IMPACT

These findings challenge prior studies that found few financial benefits to hospital-physician integration prior to PPS implementation in 1983. The results imply that financial benefits of integration may take several years after implementation to emerge, are most salient in a managed care or managed competition environment, and vary by hospital size and multihospital system membership.

[Some biochemical indexes in white rabbit's blood affected by acute high intensity microwave]

Irradiation of white rabbits by 10, 50, 100 and 200 mW/cm2 microwave respectively can cause the disorder of protein metabolism, the abnormality of blood sugar, and the change of the activity of serum alpha-hydroxybutyrate dehydrogenase, lactate dehydrogenase, glutamic oxalacetic transaminase, glutamic pyruvic transaminase, acid phosphatase ect. These changes can be used as indexes in the evaluation of the effect of acute high intensity microwave exposure. The effect on the organism mainly depends on the intensity of exposure provided the dose of microwave remains the same.

[A study on human dental embryology in an endemic high fluorosis region]

In a high endemic fluorosis area in Guizhou, China, 40 human fetuses delivered by induced abortion during the 5th-8th month of gestation were utilized to study dental embryonic samples under transmission electron microscope (TEM). Compared with normal controls, ultrastructure findings in the ameloblast cell organs include swelling of mitochondria, enlargement of SER, increase in RNA granules and RER. This study suggests that the irregularities of the collagenous fibers and crystallites are due to the maldevelopment of the ameloblast Tome's processes, which explains the mechanism of motteled enamel.

[Physiological changes in middle-aged persons and old people before and after tennis competition]

An examination of medical and physiological changes before and after tennis competition was performed on 71 middle-aged persons and old people in order to know whether they were adapted to this intense match or not. The result was that in the male group 1 (50-59 yrs), the heart rate, respiration rate and blood pressure before and after the tennis game had no significant differences (P > 0.05), indicating that this group was fit for the tennis competition, in the male group 2 (60-69 yrs) and male group 3 (70-79 yrs), as age advances, the number of unfitness to this game was increased gradually; in the female group (50-59 yrs), 28.5% of them showed a marked increase in the heart rate after the competition. We think that when persons have an electrocardiogram showing a significant undue changes of the ST segment and T wave after the contest, they are not suitable to this violent competition. So the medical surveillance is very important for the old people to play violent games such as tennis. The periodical health examination should be done before any exercise event with emphasis on the cardiovascular system so that the old sportsman can choose the proper exercise item and take self-control during the exercise.

[Aluminum and fluorine in blood and bone of rats fed on diet mixed with various contents of aluminum, fluoride or their mixture]

Wistar rats were divided into 8 groups:control, 300 ppm F, 130 ppm F, 300 ppm Al, 1200 ppm Al, 130 ppm Al + 130 ppm F. 300 ppm Al + 300 ppm F and 1200 ppm Al + 300 ppm F. The chemicals were mixed into the standard diet. The animals were fed on the diets for 12 weeks. Contents of F, Al, Ca and P in the blood (or serum) and humerus were determined at the end of 12 weeks. The results showed that the level of F in the blood and bone in the unadulterated F group was increased, especially F in the bone reached a level more than 10 times that of the control. In the 3 mixture groups, blood F and bone F were lowered, while blood F was restored to normal level, but bone F was not nevertheless, the results showed that Al was in antagonism to the absorption of F. In the unadulterated Al groups, blood and bone Al did not parallel with the amount of Al administered. The level of Al in the median Al group was higher than that of the high Al group. Taking the level of blood and bone Al as a measure, when different doses of Al were administered with F, in the low and median dosage of Al, F was in antagonism to Al absorption, but in case of high dosage of Al, F was in potentiation to Al absorption. In all the experimental groups serum P was elevated, but serum Ca was not disturbed. Bone Ca and P were decreased only in the 3 groups with unadulterated F as well as unadulterated and adulterated high dosage of Al. Mechanism of the nonlinearity of Al absorption vs Al dosage, as well as the dual effect of F on the absorption of Al was proposed.

[Effects of aluminum, fluorine and their mixtures on the enzyme activities of jejunal mucus membrane in the perfusion of small intestine of rats in vivo]

Buffer (control), F as NaF (100 mmol/L), Al as AlCl3 (32 and 170 mmol/L) and the two mixtures of Al and F (Al:F = 0.3:0.7 and 0.7:0.3) in Tris-buffered media of pH 7.0 were respectively perfused through the small intestine of rats over a period of 40 min. The jejunum was taken out from each animal immediately. Some of its parts were for HE staining; and the others for enzyme histochemical staining. Fifteen enzymes were observed. The results showed that (1) Fluorine chiefly inhibited the metal-enzymes and metal-activated enzymes; aluminum mainly depressed the activities of enzymes in relation to the cell energy metabolism, such as hydrogenases and oxidase. (2) The decreased activities of enzymes induced by Al or F increased significantly after mixing with each other, indicating that the simultaneous existence of Al and F decreased their ionic concentrations, so that strong antagonistic effects on the inhibition of enzymes were noticed since F or Al inhibited enzyme activities by their ions. (3) A high dose of Al intensively inhibited the enzymes related to the cell energy metabolism, which explained why less quantity of Al was absorbed in animals with high dose of Al than that of low dose Al seen in the absorption experiment. (4) The enzyme activities in the animals given high dose of Al mixed with F apparently were elevated in comparison with that in the animals given a pure high dose of Al which was the result of antagonistic effects of F on the inhibition of enzyme activities by Al, therefore the quantity of the absorbed Al was high.

[A study of textile noise influence on maternal function and embryo-growth]

Ninety hundred seventy-eight female textile workers exposed to noise (greater than or equal to 85 dB (A)) were recruited as the subjects of observation group, and 402 nonexposed female workers were chosen as the controls (less than 75 dB (A)). According to noise level, the observation group was subdivided into three groups: group 1, 100-104 dB (A), 416 workers; group 2, 95-99 dB, (A), 310 workers; group 3, 85-94 dB (A), 252 workers. Non-conditional logistic regression model was used to exclude the effect of mixed factors, such as age and working life. The result showed that noise-exposure could have some adverse effect on reproductive function of women and embryo growth. The workers exposed to noise had significantly increased incidence rates for irregular menstrual cycle, dysmenorrhea, lumbago, hypertension in pregnancy, threatened abortion, spontaneous abortion, premature labour, dystocia and low birth weight of newborns. When the noise intensity heightened, the sorts of abnormal function of reproduction increased and the risk of incidence raised too. These demonstrated a dose-response relationship between the noise intensity and incidence rate. The noise-working life had significant effects on the incidence of hypertension in pregnancy and prematurity. Although the age had some influence, it was not statistically significant. In terms of the maternal function and embryo growth, the factors in order of risk are: noise intensity greater than working life greater than age.

[Aluminum and fluorine absorption in a perfusion system of rat small intestine in vivo]

Mixtures of aluminum an fluorine in two different ratios in tris-hydroxy-methyl-aminomethane buffered media of pH 7.0 were perfused respectively through the small intestine of the in vivo rat over a period of 40 min. The contents of aluminum and fluorine in the portal vein blood obtained from different perfusion periods were detected and determined simultaneously. The results showed that fluorine absorption was not significant in the mixtures. An obviously large amount of aluminum was absorbed in the mixture with a higher proportion of aluminum (4660 micrograms/ml Al + 200 micrograms/ml F/L), while in the mixture with a lower dose of aluminum (860 micrograms/ml Al + 200 micrograms F/L), a small quantity of aluminum was absorbed. It is evident that the mechanism by which aluminum inhibits fluorine toxicity is that aluminum decreases the intestinal fluorine absorption by the formation of aluminum fluoride complex.

[The value of residual volume testing in determining degree of emphysema in patients with pneumoconiosis]

A comparative study of chest roentgenograms and the value of RV/TLC% in determining degree of emphysema of patients with pneumoconiosis and workers exposed to dust was made in 400 cases. Accordance rate of RV/TLC% with roentgenograms in determining emphysema in the same subjects was 61.1% and that in the patients group, 67.7%. Moreover, the accordance rate increased with grade of pneumoconiosis diagnosed. The results showed that RV/TLC% was valuable in determining emphysema of patients with pneumoconiosis. The classes of degree of emphysema were proposed according to the testing value of RV/TLC%.

[An acute experimental study on the combinations of aluminum and fluorine in various ratios]

The joint actions were assessed by four methods after male Wistar rats had been acutely intoxicated with nine proportional mixtures of Al and F. Strong antagonistic effects of Al on F were observed in the mixtures, in which the ratio of Al to F ranged from 0.8:0.2 to 0.1:0.9. The optimum ratio of Al to F for antagonism ranged from 0.3:0.7 to 0.1:0.9 without periorbital bleeding that was a regular finding in Al acute toxicity on the rat to be seen. When the amount of Al in the mixture was below 5% or above 90%, no antagonistic effect was shown. The kinetics on the absorption under the condition of Al and F existing simultaneously is still unknown, and warrants further investigation.