Risk Adjustment of ICD-10-CM Coded Potential Inpatient Complications Using Administrative Data

OBJECTIVE

To risk-adjust the Potential Inpatient Complication (PIC) measure set and propose a method to identify large deviations between observed and expected PIC counts.

DATA SOURCES

Acute inpatient stays from the Premier Healthcare Database from January 1, 2019 to December 31, 2021.

STUDY DESIGN

In 2014, the PIC list was developed to identify a broader set of potential complications that can occur as a result of care decisions. Risk adjustment for 111 PIC measures is performed across 3 age-based strata. Using patient-level risk factors and PIC occurrences, PIC-specific probabilities of occurrence are estimated through multivariate logistic regression models. Poisson Binomial cumulative mass function estimates identify deviations between observed and expected PIC counts across levels of patient-visit aggregation. Area under the curve (AUC) estimates are used to demonstrate PIC predictive performance in an 80:20 derivation-validation split framework.

DATA COLLECTION/EXTRACTION METHODS

We used N=3,363,149 administrative hospitalizations between 2019 and 2021 from the Premier Healthcare Database.

PRINCIPAL FINDINGS

PIC-specific model predictive performance was strong across PICs and age strata. Average area under the curve estimates across PICs were 0.95 (95% CI: 0.93-0.96), 0.91 (95% CI: 0.90-0.93), and 0.90 (95% CI: 0.89-0.91) for the neonate and infant, pediatric, and adult strata, respectively.

CONCLUSIONS

The proposed method provides a consistent quality metric that adjusts for the population's case mix. Age-specific risk stratification further addresses currently ignored heterogeneity in PIC prevalence across age groups. Finally, the proposed aggregation method identifies large PIC-specific deviations between observed and expected counts, flagging areas with a potential need for quality improvements.

Expression pattern of CRYAB and CTGF genes in two pig breeds at different altitudes

ABSTRACT Tibetan pigs are characterized by significant phenotypic differences relative to lowland pigs. Our previous study demonstrated that the genes CRYAB and CTGF were differentially expressed in heart tissues between Tibetan (highland breed) and Yorkshire (lowland breed) pigs, indicating that they might participate in hypoxia adaptation. CRYAB (ɑB-crystallin) and CTGF (connective tissue growth factor) have also been reported to be associated with lung development. However, the expression patterns of CRYAB and CTGF in lung tissues at different altitudes and their genetic characterization are not well understood. In this study, qRT-PCR and western blot of lung tissue revealed higher CRYAB expression levels in highland and middle-highland Tibetan and Yorkshire pigs than in their lowland counterparts. With an increase in altitude, the expression level of CTGF increased in Tibetan pigs, whereas it decreased in Yorkshire pigs. Furthermore, two novel single-nucleotide polymorphism were identified in the 5′ flanking region of CRYAB (g.39644482C>T and g.39644132T>C) and CTGF (g.31671748A>G and g.31671773T>G). The polymorphism may partially contribute to the differences in expression levels between groups at the same altitude. These findings provide novel insights into the high-altitude hypoxia adaptations of Tibetan pigs.

Socio-economic disparities in self-reported, tested, and diagnosed COVID-19 status

Backgrounds

Studies in clinical settings showed a potential relationship between Socio-Economic Status (SES) and lifestyle factors with COVID-19, but it is still unknown whether this holds in the general population. In this study we investigated the associations of SES with self-reported, tested, and diagnosed COVID-19 status in the general population.

Methods

Participants were 49,474 men and women (46 ± 12 yrs) residing in the Northern Netherlands from the Lifelines cohort study. SES indicators and lifestyle factors (i.e., smoking status, physical activity, alcohol intake, diet quality, sleep time, and TV watching time) were assessed by questionnaire from the Lifelines Biobank. Self-reported, tested, and diagnosed COVID-19 status were obtained from the Lifelines COVID-19 questionnaire.

Results

There were 4,711 participants who self-reported having had a COVID-19 infection, 2,883 participants tested for COVID-19, and 123 positive cases diagnosed in this study population. After adjustment for age, sex, lifestyle factors, BMI, and ethnicity, we found that participants with low education or low income were less likely to self-report a COVID-19 infection (OR [95%CI]: low education 0.78 [0.71-0.86]; low income 0.86 [0.79-0.93]), and be tested for COVID-19 (OR [95%CI]: low education 0.58 [0.52-0.66]; low income 0.86 [0.78-0.95]) compared with high education or high income groups, respectively.

Conclusions

Our findings suggest that the low SES group was the most vulnerable population to COVID-19 infection and self-reported and tested COVID-19 status in the general population was better predicted by SES than by lifestyle factors.

Key messages

This study innovatively included a broader range of COVID-19 status, including self-reported and tested COVID-19 status, to better understand COVID-19 related socio-economic factors. This study added evidence to the socio-economically patterned COVID-19 status in a general population instead of in clinical settings.

Neuro-Ophthalmological Manifestations of Craniosynostosis: Current Perspectives

Craniosynostosis, a premature fusion of cranial sutures that can be isolated or syndromic, is a congenital defect with a broad, multisystem clinical spectrum. The visual pathway is prone to derangements in patients with craniosynostosis, particularly in syndromic cases, and there is a risk for permanent vision loss when ocular disease complications are not identified and properly treated early in life. Extensive advancements have been made in our understanding of the etiologies underlying vision loss in craniosynostosis over the last 20 years. Children with craniosynostosis are susceptible to interruptions in visual input arising from strabismus, refractive errors, and corneal damage; any of these aberrations can result in understimulation of the visual cortex during childhood neurodevelopment and permanent amblyopia. Elevated intracranial pressure resulting from abnormal cranial shape or volume can lead to papilledema and, ultimately, optic atrophy and vision loss. A pediatric ophthalmologist is a crucial component of the multidisciplinary care team that should be involved in the care of craniosynostosis patients and consistent ophthalmologic follow-up can help minimize the risk to vision posed by such entities as papilledema and amblyopia. This article aims to review the current understanding of neuro-ophthalmological manifestations in craniosynostosis and explore diagnostic and management considerations for the ophthalmologist taking care of these patients.

[Characteristics and predictors of postoperative outcome of Crohn disease patients requiring abdominal surgery: a series of 1 048 cases from a single inflammatory bowel disease centre]

Objective: To examine the clinical characteristics, the potential relative factors for postoperative abdominal septic complications, and prognosis factors of surgical recurrence of Crohn disease (CD) patients after the first surgery. Methods: All the CD patients from Department of General Surgery, Jinling Hospital, Medical School of Nanjing University who had undergone at least one abdominal surgery from January 2007 to December 2017 were included for retrospective analysis. Hospital records were reviewed for information on clinical characteristics. Relative factors of postoperative abdominal septic complications were accessed by Logistic regression models, and prognosis factors of surgical recurrence were accessed by Cox proportional hazards regression models. Results: There were 1 048 patients included (733 males and 315 females), accounting for 1 513 operations. The age was 31(17) years and the length of resected small bowel was 30.0(40.0) cm at the first resection, 20.0(35.0) cm at the second resection, and 20.0(23.5) cm at the third resection. The length of resected small bowel was 25.0(40.0) cm at any resection. At the first abdominal surgery, 70.99%(744/1 048) patients were aged between 17 and 40 years, 66.98%(702/1 048) patients had ileocolonic disease, and 60.40%(633/1 048) patients had penetrating behavior. Penetrating behavior (OR=8.594, 95%CI: 3.397 to 21.740, P<0.01) and current smoking status (OR=2.671, 95%CI: 1.044 to 6.832, P=0.040) were significantly associated with an increased risk of postoperative septic complications, whereas staged operation (OR=0.360, 95%CI: 0.184 to 0.707, P=0.003) was associated with a decreased risk. Male gender (HR=1.500, 95%CI: 1.128 to 1.995, P=0.005), upper gastrointestinal disease (HR=1.526, 95%CI: 1.033 to 2.255, P=0.034), penetrating behavior (HR=1.506, 95%CI: 1.132 to 2.003, P=0.005) and emergency surgery (HR=1.812, 95%CI: 1.375 to 2.387, P<0.01) were significantly associated with an increased risk of postoperative surgical recurrence, whereas staged operation (HR=0.361, 95%CI: 0.227 to 0.574, P<0.01) was significantly associated with a decreased risk. Conclusions: In this cohort of CD patients receiving abdominal surgery from an inflammatory bowel disease center, the median age was 31 years and the median length of resected small bowel was 30 cm, at first resection. Patients who have risk factors of adverse postoperative outcome may be benefited from staged surgical approach.

[Clinical characteristics of elderly and younger onset rheumatoid arthritis]

Objective: To compare the clinical and laboratory characteristics and therapy methods of elderly onset rheumatoid arthritis (EORA) and younger onset rheumatoid arthritis (YORA). Methods: The clinical, laboratory and therapeutic data of 481 RA patients in the Department of Rheumatology and Immunology in Peking University Third Hospital from January 2013 to December 2018 were collected and used to analyze the difference of characteristics between EORA group and YORA group, which might be useful for better diagnosis and treatment of EORA patients. Quantitative data of normal distribution were compared with t test between the two groups. Results: There were 481 patients in this cohort, of which 137(28.5%) were EORA, 344(71.5%) were YORA, with a mean age of (59±14) years (19-87 years). There were 358 females (74.4%) and 123 males (25.6%). The percentage of male patients was obviously higher in EORA group (36.5% vs 21.2%, χ(2)=12.012, P<0.01), and the average disease course was obviously shorter (Z=-7.985, P<0.01). Disease Activity Score 28 (DAS28) score was higher in EORA group (5.6±1.3 vs 5.2±1.6, t=2.549, P<0.05), meanwhile the incidences of pleural effusion and interstitial lung disease (ILD) were higher (6.6% vs 1.7%, 29.9% vs 18.3%, respectively; χ(2)=7.550, 7.797, both P<0.05). The incidences of venous thrombosis, primary hypertension, diabetes mellitus, cerebrovascular disease, coronary heart disease (CHD), peripheral atherosclerosis and cataract in EORA group were all significantly higher than those in YORA group (all P<0.05). Erythrocyte sedimentation rate (ESR) and D-Dimer in EORA group were all remarkably higher (both P<0.05). The rate of using glucocorticoid in EORA group was higher but the rate of using methotrexate and anti-tumor necrosis factor-α agents were lower (χ(2)=5.271, 8.407, 9.356, all P<0.05). Conclusion: Compared to YORA group, the percentage of male patients and disease activity of EORA group are higher. The occurrence of pleural effusion, ILD, venous thrombosis, primary hypertension, diabetes mellitus, cerebrovascular disease, CHD, peripheral atherosclerosis and cataract in EORA group are higher than those in YORA group.

A 26-Year-old Woman With Dysuria and Hematuria

In this case, we present imaging findings characteristic of chronic genitourinary schistosomiasis. Schistosoma haematobium, a blood fluke endemic to Africa and the Middle East, is a prominent cause of hematuria and bladder cancer in regions lacking adequate water sanitation. Luminal calcifications of the genitourinary tract, that is, of the bladder and/or ureters, from deposition of fluke eggs are a classic sign of chronic S. haematobium infection and should raise suspicion for the disease even when urine or serological tests are negative. It is important to recognize these findings on CT or, in resource-limited settings, plain film to allow for prompt, effective treatment.

Characterization of gut microbiota and short-chain fatty acid in breastfed infants with or without breast milk jaundice

This study aims to investigate the gut microbiota and metabolites in breastfed infants with breast milk jaundice (BMJ) using gut microbiome-metabolomics. Breastfed newborns diagnosed with BMJ and those without BMJ (control group) were enrolled. Faecal samples were collected from the participants and subjected to high-throughput sequencing of the 16s rDNA V3 and V4 regions of the gut flora and metabolomics of short-chain fatty acids (SCFAs). Proteobacteria, Fimicutes and Actinobacteria were the main bacteria at the phylum level. Eshcerichia-Shigella and Enterobacteriacea were the main bacteria at the genus level. The difference between the two groups was compared. Compared to the control group, the amount of Streptococcus was significantly increased while the amount of Enterococcus was significantly decreased in the faeces from infants with BMJ. Functional prediction analysis of 16S found that biosynthesis of penicillin and cephalosporin significantly increased in the BMJ group. Gas chromatography-mass spectrometry detection of SCFAs revealed that levels of acetic acid and propionic acid were significantly lower in the BMJ group than in the control group. The reduced levels of acetic acid and propionic acid may be related to the increase in Streptococcus and decrease in Enterococcus, both of which may contribute to BMJ.

Associations of ultra-processed food and its consumption patterns with incident type 2 diabetes

Background

To study the associations of the consumption of ultra-processed food (UPF) and its underlying habitual consumption patterns with incident type 2 diabetes (T2D) in a large population-based cohort.

Methods

In 70 421 participants (35-70 years, 58.6% women) from the Lifelines cohort study, dietary intake was assessed with a food frequency questionnaire. Principal component analysis (PCA) was performed to derive UPF consumption patterns. UPF was related to incident diabetes with adjustments for confounders, including overall diet quality.

Results

During a median follow-up of 41 months, the intake of UPF was associated with higher risk of type 2 diabetes (1128 cases, OR for a 10% increment in UPF intake 1.33 [95% CI 1.26, 1.41]), and remained significant after adjustment for confounders. PCA revealed four habitual UPF consumption patterns. A pattern high in cold savory snacks (OR 1.16 [95% CI 1.09, 1.22]) and a pattern high in warm savory snacks (OR 1.15 [95% CI 1.08, 1.21]) were associated with an increased diabetes risk; a pattern high in traditional Dutch cuisine was not associated with diabetes risk (OR 1.05 [95% CI 0.97, 1.14]); while a pattern high in sweet snacks and pastries was inversely associated with diabetes risk (OR 0.82 [95% CI 0.76, 0.89]). There was a clear inverse association between diabetes risk at baseline and the sweet snacks and pastries pattern (β = -0.104 [95% CI -0.113, -0.094]).

Conclusions

A higher consumption of UPF was associated with higher risk of type 2 diabetes. For consumption patterns, this association was most pronounced for the patterns that were high in savory snacks. Our findings emphasize that in addition to promoting the consumption of healthy food products, discouraging the consumption of UPF, specifically savory snacks, should be considered as part of future diabetes prevention strategies.

Key messages

Ultra-processed foods intake was associated with increased risk of type 2 diabetes. Consumption patterns of ultra-processed foods should be the focus for future policies.

Using Structural Equation Modelling to Untangle Pathways of Factors Associated with Type 2 Diabetes

Background

Risk factors for type 2 diabetes (T2D) are multi-facet and interrelated. We aimed to apply structural equation modelling to examine and quantify pathways of modifiable risk factors related to incident type 2 diabetes.

Methods

Analysis was based on 68 649 participants (35-80 years, without diabetes at baseline) from the Lifelines cohort study. We proposed a conceptual model that illustrates the pathways of risk factors related to incident type 2 diabetes: socio-economic status (income and education) → lifestyle behaviors (diet quality, physical activity, TV watching, and smoking) → clinical markers (blood lipids and obesity status) → incident type 2 diabetes. Structural equation modeling was performed to test this proposed model.

Results

After a median follow-up of 41 months, 1124 new cases of type 2 diabetes were identified. The best-fitting model indicated that among all modifiable risk factors included, waist circumference had the biggest direct effect on type 2 diabetes (β: 0.213 ), followed by HDL-cholesterol (β: -0.141). Less TV watching and more physical activity were found to play an important role in improving clinical markers that were directly associated with type 2 diabetes. Education had the biggest direct effects on all lifestyle behaviors.

Conclusions

Using this innovative approach, our analysis provides a more nuanced assessment of the interplay of type 2 diabetes risk factors, compared to traditional risk estimates. Our results indicated that reducing large waist circumference may be prioritized as the main target for the prevention of type 2 diabetes, and lifestyle interventions are urgently warranted with additional support for those with a low education.

Key messages

Our study elucidated the multiple causal pathways to type 2 diabetes in a prospective setting. Our results identified the most critical targets for future prevention strategies for type 2 diabetes.

The plant pathogen enzyme AldC is a long-chain aliphatic aldehyde dehydrogenase

Aldehyde dehydrogenases are versatile enzymes that serve a range of biochemical functions. Although traditionally considered metabolic housekeeping enzymes because of their ability to detoxify reactive aldehydes, like those generated from lipid peroxidation damage, the contributions of these enzymes to other biological processes are widespread. For example, the plant pathogen Pseudomonas syringae strain PtoDC3000 uses an indole-3-acetaldehyde dehydrogenase to synthesize the phytohormone indole-3-acetic acid to elude host responses. Here we investigate the biochemical function of AldC from PtoDC3000. Analysis of the substrate profile of AldC suggests that this enzyme functions as a long-chain aliphatic aldehyde dehydrogenase. The 2.5 Å resolution X-ray crystal of the AldC C291A mutant in a dead-end complex with octanal and NAD⁺ reveals an apolar binding site primed for aliphatic aldehyde substrate recognition. Functional characterization of site-directed mutants targeting the substrate- and NAD(H)-binding sites identifies key residues in the active site for ligand interactions, including those in the "aromatic box" that define the aldehyde-binding site. Overall, this study provides molecular insight for understanding the evolution of the prokaryotic aldehyde dehydrogenase superfamily and their diversity of function.

[Clinical significance and mechanism of TBX5 gene in colorectal cancer]

Objective: To examine the expression of T-box5 (TBX5) in colorectal cancer tissues and its clinical significance, and explore the effects of TBX5 on the invasion and metastasis of colorectal cancer cells and its mechanism. Methods: The expressions of TBX5 in cancer and adjacent normal tissues were tested by immunohistochemistry (IHC), and the relationship between TBX5 and clinicopathological features and prognosis of colorectal cancer was analyzed. Real-time quantitative PCR (RT-qPCR) and western blot were used to detect the expressions of TBX5 in different colorectal cancer cell lines. TBX5 overexpression plasmid was constructed and transfected into human colorectal cancer cell line HT-29, and cell counting kit-8 (CCK-8) was used to detect the activities of transfection HT-29 cells. Cell scratch test and Transwell assay were used to detect the migration and invasion abilities of cells, while RT-qPCR and western blot were used to detect the mRNA and protein expressions of PCNA, p21, p16, p27, MMP-2, MMP-7 and TIMP-1. Results: The positive rate of TBX5 protein in colorectal cancer tissues was 24.44% (22/90), significantly lower than 65.56% of adjacent normal tissues (P<0.001). The expression of TBX5 was significantly related to lymph node metastasis, depth of invasion and nerve invasion (P<0.05). The survival period of 22 patients with positive TBX5 expression was (60.2±2.4) months, better than (44.3±2.8) months of 68 patients with negative TBX5 expression (P<0.05). Among human colon cancer cell lines of HT29, SW620, SW480, LOVO and HCT116, the expression of TBX5 in HT29 cells was the weakest. After transfection, the expression of TBX5 in transfection group was significantly higher than those in control group and blank group (P=0.043 and P<0.001). Cell viability in transfection group was significantly lower than those in control group and blank group (both P<0.001). The ratio of cells in G(0)/G(1) phase was increased (P=0.009), while in G(2)/M phase was decreased (P<0.001). Cells' abilities of migration and invasion in transfection group were also significantly decreased (both P<0.001). Overexpression of TBX5 downregulated the expressions of PCNA, MMP-2 and MMP-7, while upregulated the expressions of p21, p16, p27 (P<0.05 for all). TBX5 had marginal effect on the expression of TIMP-1 (P>0.05). Conclusions: Downregulation of TBX5 is a marker of poor prognosis in patients with colorectal cancer. TBX5 may inhibit the progression of colorectal cancer by inhibiting proliferation, invasion and metastasis related genes.

Association of in-hospital resource utilization with post-acute spending in Medicare beneficiaries hospitalized for acute myocardial infarction: a cross-sectional study

BACKGROUND

Efforts to decrease hospitalization costs could increase post-acute care costs. This effect could undermine initiatives to reduce overall episode costs and have implications for the design of health care under alternative payment models.

METHODS

Among Medicare fee-for-service beneficiaries aged ≥65 years hospitalized with acute myocardial infarction (AMI) between July 2010 and June 2013 in the Premier Healthcare Database, we studied the association of in-hospital and post-acute care resource utilization and outcomes by in-hospital cost tertiles.

RESULTS

Among patients with AMI at 326 hospitals, the median (range) of each hospital's mean per-patient in-hospital risk-standardized cost (RSC) for the low, medium, and high cost tertiles were $16,257 ($13,097-$17,648), $18,544 ($17,663-$19,875), and $21,831 ($19,923-$31,296), respectively. There was no difference in the median (IQR) of risk-standardized post-acute payments across cost-tertiles: $5014 (4295-6051), $4980 (4349-5931) and $4922 (4056-5457) for the low (n = 90), medium (n = 98), and high (n = 86) in-hospital RSC tertiles (p = 0.21), respectively. In-hospital and 30-day mortality rates did not differ significantly across the in-hospital RSC tertiles; however, 30-day readmission rates were higher at hospitals with higher in-hospital RSCs: median = 17.5, 17.8, and 18.0% at low, medium, and high in-hospital RSC tertiles, respectively (p = 0.005 for test of trend across tertiles).

CONCLUSIONS

In our study of patients hospitalized with AMI, greater resource utilization during the hospitalization was not associated with meaningful differences in costs or mortality during the post-acute period. These findings suggest that it may be possible for higher cost hospitals to improve efficiency in care without increasing post-acute care utilization or worsening outcomes.

The effectiveness of robotic hip and knee arthroplasty on patient-reported outcomes: A systematic review and meta-analysis

PURPOSE

The purpose of the study is to determine the effectiveness of semi-active and active robotic hip and knee arthroplasty on post-operative patient-reported outcomes of function, pain, quality of life and satisfaction with surgery.

METHODS

PubMed, Medline, Embase and CENTRAL were searched. Included were comparative studies investigating the effectiveness of semi-active or active robotic hip or knee arthroplasty compared to any other surgical intervention on function, pain, quality of life and satisfaction with surgery. Risk of bias and the strength of the evidence were assessed using the Downs and Black tool and the GRADE system, respectively. Relative risks, mean differences and 95% CI were calculated using random-effects models.

RESULTS

Fourteen studies involving 1342 patients were included. All studies compared robotic to conventional surgery, with active robotic surgery evaluated in total hip or knee arthroplasty and semi-active robotic surgery in total hip or unicompartmental knee arthroplasty. Most studies presented some risk of bias, and the strength of evidence was rated as low to very low quality. Random-effects meta-analyses showed that post-operative functional outcomes were comparable between active robotic and conventional total hip and knee arthroplasty at the short-, medium- and long-term follow-up. No significant difference in pain, quality of life and satisfaction with surgery were reported in individual studies.

CONCLUSIONS

This systematic and meta-analyses indicates that functional outcomes for patients undergoing active robotic total hip and knee arthroplasty were comparable to conventional surgery. Whether semi-active or active robotic hip or knee arthroplasty is effective in improving post-operative pain, quality of life and satisfaction with surgery is unclear. PROSPERO Registration Number: CRD42017059932.

Selectivity of a QCM gas sensor modified by ZnSn(OH)6via analysis of adsorption thermodynamics and kinetics

In this paper, a novel analysis approach was employed to achieve the selectivity of a quartz crystal microbalance (QCM) sensor.

CD11b immunophenotyping identifies inflammatory profiles in the mouse and human lungs

The development of easily accessible tools for human immunophenotyping to classify patients into discrete disease endotypes is advancing personalized therapy. However, no systematic approach has been developed for the study of inflammatory lung diseases with often complex and highly heterogeneous disease etiologies. We have devised an internally standardized flow cytometry approach that can identify parallel inflammatory alveolar macrophage phenotypes in both the mouse and human lungs. In mice, lung innate immune cell alterations during endotoxin challenge, influenza virus infection, and in two genetic models of chronic obstructive lung disease could be segregated based on the presence or absence of CD11b alveolar macrophage upregulation and lung eosinophilia. Additionally, heightened alveolar macrophage CD11b expression was a novel feature of acute lung exacerbations in the SHIP-1(-/-) model of chronic obstructive lung disease, and anti-CD11b antibody administration selectively blocked inflammatory CD11b(pos) but not homeostatic CD11b(neg) alveolar macrophages in vivo. The identification of analogous profiles in respiratory disease patients highlights this approach as a translational avenue for lung disease endotyping and suggests that heterogeneous innate immune cell phenotypes are an underappreciated component of the human lung disease microenvironment.

Efficiency of live attenuated and inactivated rabies viruses in prophylactic and post exposure vaccination against the street virus strain

Rabies remains an enigmatic and widely discussed global infectious disease and causes an increasing number of deaths. The currently used highly effective prophylactic and post exposure (p.e.) vaccination depends solely upon inexpensive, effective and safe vaccines to counteract the spread of the disease. In this study, the potential of an attenuated Chinese rabies vaccine (SRV9) strain in prophylactic and p.e. vaccination against the street strain of rabies virus (RV) was evaluated in mice. Prophylactic vaccination consisting of one intramuscular (i.m.) dose of SRV9 protected 100% of mice from intracerebral (i.c.) challenge with a lethal dose of the street virus. The latter was detected in the brain of mice at day 6 post challenge by RT-PCR. Post exposure vaccination was performed at days 1, 2, 3, 4, 5 and 6 post infection (p.i.) with either SRV9 or inactivated rabies vaccine. The survival rates after i.m. inoculation of SRV9 at the indicated days were 70%, 50%, 30%, 20%, 10%, and 0%, respectively; the corresponding survival rates for the inactivated rabies vaccine were 30%, 20%, 10%, 0%, 0%, and 0%, respectively. However, 100%, 90%, 70%, 50%, 20%, 10%, and 10% of mice survived after i.c. inoculation of SRV9 at the indicated days. The increased permeability of the blood-brain barrier and the infiltration of CD19+ B cells into the central nervous system after i.c. inoculation of SRV9 are regarded as prerequisites for the clearance of the street virus. The obtained data suggest that SRV9 is a promising candidate for prophylactic and p.e. vaccination against rabies infection and that it exhibits a potential for the control of rabies in China.

Alterations in microRNA expression profile in rabies virus-infected mouse neurons

Rabies virus (RABV) is known to cause a fatal infection in many mammalian species, yet its pathogenesis remains poorly understood. This study was performed to analyze the microRNA (miRNA) expression profiles in RABV-infected primary neurons of mice. A total of 53 miRNAs were found to be differentially expressed in RABV-infected samples compared with mock samples in a time-dependent manner. Among them, the expression of ten miRNAs was validated by real-time RT-PCR. Potential target genes of differentially expressed miRNAs were predicted by TargetScan. Further bioinformatics analysis indicated that these predicted targets were overrepresented in neuronal function-related Gene Ontology (GO) terms and biological pathways. The results of this study suggest that RABV may cause neuronal dysfunction by regulating cellular miRNA expression.

"Phenotyping" hospital value of care for patients with heart failure

OBJECTIVE

To characterize hospitals based on patterns of their combined financial and clinical outcomes for heart failure hospitalizations longitudinally.

DATA SOURCE

Detailed cost and administrative data on hospitalizations for heart failure from 424 hospitals in the 2005-2011 Premier database.

STUDY DESIGN

Using a mixture modeling approach, we identified groups of hospitals with distinct joint trajectories of risk-standardized cost (RSC) per hospitalization and risk-standardized in-hospital mortality rate (RSMR), and assessed hospital characteristics associated with the distinct patterns using multinomial logistic regression.

PRINCIPAL FINDINGS

During 2005-2011, mean hospital RSC decreased from $12,003 to $10,782, while mean hospital RSMR declined from 3.9 to 3.2 percent. We identified five distinct hospital patterns: highest cost and low mortality (3.2 percent of the hospitals), high cost and low mortality (20.4 percent), medium cost and low mortality (34.6 percent), medium cost and high mortality (6.2 percent), and low cost and low mortality (35.6 percent). Longer hospital stay and greater use of intensive care unit and surgical procedures were associated with phenotypes with higher costs or greater mortality.

CONCLUSIONS

Hospitals vary substantially in the joint longitudinal patterns of cost and mortality, suggesting marked difference in value of care. Understanding determinants of the variation will inform strategies for improving the value of hospital care.

Risk-taking behaviour may explain high predation mortality of GH-transgenic common carp Cyprinus carpio

The competitive ability and habitat selection of juvenile all-fish GH-transgenic common carp Cyprinus carpio and their size-matched non-transgenic conspecifics, in the absence and presence of predation risk, under different food distributions, were compared. Unequal-competitor ideal-free-distribution analysis showed that a larger proportion of transgenic C. carpio fed within the system, although they were not overrepresented at a higher-quantity food source. Moreover, the analysis showed that transgenic C. carpio maintained a faster growth rate, and were more willing to risk exposure to a predator when foraging, thereby supporting the hypothesis that predation selects against maximal growth rates by removing individuals that display increased foraging effort. Without compensatory behaviours that could mitigate the effects of predation risk, the escaped or released transgenic C. carpio with high-gain and high-risk performance would grow well but probably suffer high predation mortality in nature.

Identifying hospital-wide harm: a set of ICD-9-CM-coded conditions associated with increased cost, length of stay, and risk of mortality

This study identifies an expanded set of hospital-acquired conditions (HACs), using the Present-On-Admission (POA) indicator and secondary diagnoses present on International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)-coded discharge abstracts and evaluates their association with mortality, length of stay (LOS), and cost. A sample of 500 000 de-identified ICD-9-CM-coded discharge abstracts was randomly drawn from a data set of 11 million. A total of 138 secondary condition clusters were identified as potential inpatient complications (PICs). Regression modeling was used to determine marginal association of each PIC with mortality, LOS, and cost. In all, 16% of hospitalized patients developed 1 or more of these conditions while in the hospital compared with less than 1% of inpatients experiencing HACs defined by the Centers for Medicare and Medicaid Services. Also, 74 PICs were associated with seriously higher mortality rates (5 excess deaths per 1000), significantly LOS (0.4 extra days per discharge), and significantly higher costs (an extra $1000 per discharge).

Identification of cellular proteins interacting with influenza A virus PB1-F2 protein

The influenza A virus (IAV) protein PB1-F2, which is encoded by an alternative ORF of the PB1 polymerase gene, has been implicated as an important virulence factor and apoptosis inducer. However, the molecular mechanism of PB1-F2 function remains elusive. In this study, eight cellular proteins were identified as potential PB1-F2 interacting partners using the yeast two-hybrid system. Two positive candidate proteins, guanine nucleotide binding protein (G protein) beta polypeptide 2 (Gβ2) and macrophage migration inhibitory factor (MIF), were selected to be further characterized. The interaction of MIF and Gβ2 with PB1-F2 was confirmed by both GST pull-down and co-immunoprecipitation assays. Confocal laser microscopy showed that the interaction between PB1-F2 and the two cellular proteins occurred in the cytoplasm. The novel interactions between PB1-F2 and host proteins provide further pieces of evidence in the investigation of the pathogenic mechanism of IAV.

KEYWORDS

influenza A virus; PB1-F2; yeast two-hybrid; protein-protein interaction.

Exosome-mediated shuttling of microRNA-29 regulates HIV Tat and morphine-mediated neuronal dysfunction

Neuronal damage is a hallmark feature of HIV-associated neurological disorders (HANDs). Opiate drug abuse accelerates the incidence and progression of HAND; however, the mechanisms underlying the potentiation of neuropathogenesis by these drugs remain elusive. Opiates such as morphine have been shown to enhance HIV transactivation protein Tat-mediated toxicity in both human neurons and neuroblastoma cells. In the present study, we demonstrate reduced expression of the tropic factor platelet-derived growth factor (PDGF)-B with a concomitant increase in miR-29b in the basal ganglia region of the brains of morphine-dependent simian immunodeficiency virus (SIV)-infected macaques compared with the SIV-infected controls. In vitro relevance of these findings was corroborated in cultures of astrocytes exposed to morphine and HIV Tat that led to increased release of miR-29b in exosomes. Subsequent treatment of neuronal SH-SY5Y cell line with exosomes from treated astrocytes resulted in decreased expression of PDGF-B, with a concomitant decrease in viability of neurons. Furthermore, it was shown that PDGF-B was a target for miR-29b as evidenced by the fact that binding of miR-29 to the 3′-untranslated region of PDGF-B mRNA resulted in its translational repression in SH-SY5Y cells. Understanding the regulation of PDGF-B expression may provide insights into the development of potential therapeutic targets for neuronal loss in HIV-1-infected opiate abusers.

Apples and oranges: comparison of ACS-NSQIP observed outcomes with premier's quality manager-predicted outcomes

The National Surgical Quality Improvement Program (NSQIP) is used by the American College of Surgeons to measure and report surgical quality and outcomes. Premier's Quality Manager (QM) generates expected outcomes from patient charts. The authors compared observed NSQIP morbidity and mortality outcomes with those predicted by QM. NSQIP data for 1919 patients were entered into QM. The discriminatory accuracy of the QM model was assessed using the C statistic (1.0 implies perfect discrimination, and 0.5 implies no discrimination). NSQIP and QM both identified 51 deaths (C statistic, 0.91). NSQIP identified 478 postoperative occurrences, whereas QM predicted 714 patients with at least 1 complication; 223 of these were subclassified as patients with at least 1 morbid complication (C statistic, 0.83). QM did not perform as well in predicting the observed NSQIP morbidities. Surgical leaders and hospital administrators must critically evaluate products before adopting programs designed to improve patient outcomes or making decisions regarding physician practice.

Elevated ability to compete for limited food resources by 'all-fish' growth hormone transgenic common carp Cyprinus carpio

Food consumption, number of movements and feeding hierarchy of juvenile transgenic common carp Cyprinus carpio and their size-matched non-transgenic conspecifics were measured under conditions of limited food supply. Transgenic fish exhibited 73.3% more movements as well as a higher feeding order, and consumed 1.86 times as many food pellets as their non-transgenic counterparts. After the 10 day experiment, transgenic C. carpio had still not realized their higher growth potential, which may be partly explained by the higher frequency of movements of transgenics and the 'sneaky' feeding strategy used by the non-transgenics. The results indicate that these transgenic fish possess an elevated ability to compete for limited food resources, which could be advantageous after an escape into the wild. It may be that other factors in the natural environment (i.e. predation risk and food distribution), however, would offset this advantage. Thus, these results need to be assessed with caution.

Influence of hydroxyethyl starch 130/0.4 in pulmonary neutrophil recruitment and acute lung injury during polymicrobial sepsis in rats

BACKGROUND

Acute lung injury (ALI) is a progressive syndrome associated with significant mortality in sepsis patients. Neutrophils are key cells in the inflammatory response that characterizes ALI. This study was designed to explore the effects of hydroxyethyl starch (HES) 130/0.4 (a novel plasma substitute) on pulmonary neutrophil recruitment and associated ALI in a rat sepsis model induced by cecal ligation and puncture (CLP).

METHODS

Animals were randomly assigned to six groups [saline control; CLP and saline; CLP and HES (7.5, 15 and 30 ml/kg); and HES control], subjected to CLP and infused with or without HES 130/0.4 4 h after CLP. Six hours later, the pulmonary capillary permeability (PCP), myeloperoxidase (MPO) activity, lung histological changes, tumor necrosis factor-alpha, interleukin-1beta and cytokine-induced neutrophil chemoattractant levels, P-selectin mRNA expression and nuclear factor-kappa B (NF-kappaB) activation were measured.

RESULTS

Resuscitation with HES 130/0.4 significantly attenuated the CLP-induced increase in PCP, MPO activity, cytokine/chemokine levels, mRNA expression of P-selectin and NF-kappaB activation, all of which are involved in the recruitment of neutrophils. Groups receiving the higher doses of HES 130/0.4 (15 and 30 ml/kg) were more adequately resuscitated.

CONCLUSION

HES 130/0.4 can inhibit CLP-induced neutrophil recruitment and subsequent ALI by attenuating cytokines/chemokines, adhesion molecule-mediated inflammation and NF-kappaB activation.

Xenografted fetal dorsal root ganglion, embryonic stem cell and adult neural stem cell survival following implantation into the adult vestibulocochlear nerve

Sensorineural hearing loss is a disabling condition. In the post-embryonic and adult mammalian inner ear, the regeneration of auditory hair cells, spiral ganglion neurons or their axons does not occur naturally. This decrease in excitable neurons limits the success of auditory rehabilitation. Allografts and xenografts have shown promise in the treatment of a variety of neurological diseases. Fetal dorsal root ganglion (DRG) neurons can extend functional connections in the rat spinal cord. Embryonic stem cells (ES cells) and adult neural stem cells (ANSC) have the potential to differentiate into neurons. We have implanted embryonic days (E) 13-16 fetal mouse DRGs from transgenic mouse lines that express Enhanced Green Fluorescent Protein (EGFP) or lacZ reporter genes, EGFP-expressing ES cells or lacZ-expressing ANSC into the injured vestibulocochlear nerve of adult rats and guinea pigs. Survival of the implants was assessed 2 to 4 weeks postoperatively. For further evaluation of the differentiation of the implanted ES-cells, we double labeled with the mouse-specific neuronal antibody Thy 1.2. The rats implanted with EGFP- or lacZ-expressing DRGs showed labeled DRGs after sacrifice. In addition, EGFP-positive nerve fibers were seen growing within the proximal nerve. The results from the EGFP ES cells and lacZ ANSC revealed reporter-expressing cells at the site of injection in the vestibulocochlear nerve of the host rats and guinea pigs but also within the brain stem. Thy 1.2 profiles were seen among the EGFP ES cells within the 8th cranial nerve. The findings of this study indicate that the vestibulocochlear nerve of adult rats and guinea pigs will support xenotransplants of embryonic DRG, ES cells and ANSC. This may have future clinical applicability in recreating a neuronal conduit following neuronal injury between the inner ear and the central nervous system (CNS).

Large dose ketamine inhibits lipopolysaccharide-induced acute lung injury in rats

BACKGROUND

Sepsis is associated with the highest risk of progression to acute lung injury or the acute respiratory distress syndrome. Ketamine has been advocated for anesthesia in endotoxemic and other severely ill patients because it is a cardiovascular stimulant. Our study was designed to investigate the effect of ketamine on the endotoxin-induced acute lung injury in vivo.

MATERIALS AND METHODS

Adult male Wistar rats were randomly divided into 6 groups: saline controls; rats challenged with endotoxin (5 mg/kg) and treated with saline; challenged with endotoxin (5 mg/kg) and treated with ketamine (0.5 mg/kg); challenged with endotoxin (5 mg/kg) and treated with ketamine (5 mg/kg); challenged with endotoxin (5 mg/kg) and treated with ketamine (50 mg/kg); saline injected and treated with ketamine (50 mg/kg). TNF-alpha, IL-6 and NF-kappa B were investigated in the tissues of the lung after 2 h. Myeloperoxidase (MPO) activity and wet/dry weight ratio were investigated 6 h later.

RESULTS

We demonstrated that intravenous administration of endotoxin could provoke significant lung injury, which was characterized by increase of MPO activity and wet/dry weight ratio, TNF-alpha and IL-6 expression and NF-kappa B activation. Ketamine (5, 50 mg/kg) inhibited endotoxin-induced NF-kappa B activation. Ketamine only at a dose of 50 mg/kg inhibited TNF-alpha and IL-6 production, and decreased MPO activity and wet/dry weight ratio after endotoxin challenge.

CONCLUSIONS

Ketamine, only at a supra-anesthetic dosage, could inhibit endotoxin-induced pulmonary inflammation in vivo.

Results of surgical treatment of congenital cystic lung disease

OBJECTIVE

To review the experience with surgical intervention for congenital cystic lung disease (CCLD).

METHODS

From April 1988 to December 2001, 68 patients were diagnosed and treated surgically for CCLD. There were 27 males and 41 females ranging in age from 2 to 65 years. The majority of the cases were diagnosed by history, clinical manifestations and chest radiography or computerized tomography (CT). There were 25 (36.8 %) right-sided and 43 (63.2 %) left-sided cystic lung lesions. Four patients had massive bleeding and needed urgent or emergency operation. Pneumonectomy, lobectomy, and/or segmentectomy were performed.

RESULTS

29 (42.6 %) patients underwent lobectomy, 25 (36.8 %) had total pneumonectomy, 9 (13.2 %) lobectomy plus segmentectomy, and 5 (7.4 %) bilobectomy. During the operation, left-sided pulmonary sequestration was confirmed in 3 patients. No death occurred in this series. Diagnoses were confirmed by pathology in all cases. Two patients had malignant lesions arising from multicystic lung lesions.

CONCLUSIONS

A history of recurrent pneumonia, often with hemoptysis and subsequent dyspnea, should raise the suspicion of CCLD. The diagnosis can be confirmed by chest X-ray and CT preoperatively, and early surgical intervention may avoid the development of serious complications. Delayed diagnosis and surgical management usually result in significant morbidity and mortality.

Treatment of peripheral sensorineural hearing loss: gene therapy

Noise, chemicals and genetic defects are all common causes of irreversible hearing loss, which at present have no cure. Gene therapy may soon be utilized in both the protection and the treatment of these exogenous and endogenous sources of hearing loss. Gene therapy technology is rapidly developing and the inner ear is a particularly feasible model for gene therapy. This review outlines our current understanding of the mechanisms behind deafness and prospects for treatment, discusses the inner ear model in detail and reviews the efforts that have been made in inner ear gene therapy. Finally, the proposed next steps will be discussed. The viral mediated delivery of neurotrophins and antioxidants offers imminent promise in preventing and treating exogenous hearing loss and improving cochlear implant therapy.

[Determination of micro-elements in natural spirulina using FAAS]

The analytic results show that the spirulina powder have a plenty of microelements(K, Na, Ca, Mg, Fe, Zn). Compared with that of rice, wheat flour, maize and soybean, the content of K, Na, Ca, Mg, Fe and Zn of it is respectively as from 4 to 10 times, from 10 to 80 times, from 25 to 70 times, from 3 to 15 times, from 4 to 36 times and from 4 to 24 times as theirs. The content of microelements of it compared with vegetable is much higher. The spirulina has a certain inhibition from cancer, high blood pressure, sugar diabetes and hasten body to absorb Se and Mo, and is of benefit to cardiac muscle. The experimental result indicated that spirulina was good health care food with value of nourish and medicinal.

Study on colloidal Au-enhanced DNA sensing by quartz crystal microbalance

Colloidal Au is reported for enhancement the immobilization capacity and ultimately detection limit of DNA using quartz crystal microbalance (QCM). Immobilization of approximately 12 nm-diameter colloidal Au on to an Au-coated QCM resulted in an easier attachment of oligonucleotide, with a mercaptohexyl group at the 5'-phosphate end and an increased capacity for nucleic acid detection. DNA immobilization and hybridization was monitored from QCM frequency changes. Hybridization was induced by exposure of the DNA-containing films to complementary DNA in solution. A much higher sensitivity was obtained for the analyte. The Au nanoparticle films on the Au plate provide a novel means for the fabrication of DNA sensor.

Complementary roles of neurotrophin 3 and a N-methyl-D-aspartate antagonist in the protection of noise and aminoglycoside-induced ototoxicity

Recent progress has been made regarding the prevention of hearing loss. However, the complete protection of both hair cells and spiral ganglion neurons, with restored function, has not yet been achieved. It has been shown that spiral ganglion neuronal loss can be prevented by neurotrophin 3 (NT3) and hair cell damage by N-methyl-D-aspartate (NMDA) receptor antagonists. Here we demonstrate that the combined treatment with MK801, a NMDA antagonist, and NT3 protect both cochlear morphology and physiology from injury. Pretreatment with MK801 prevented hearing loss and the dendrites of the spiral ganglion neurons from swelling after noise-induced damage. The acute phase of insult with the aminoglycoside antibiotic amikacin resulted in swollen afferent dendrites beneath the inner hair cells. The chronic phase resulted in complete hair cell loss and near-complete loss of spiral ganglion neurons. This damage caused a near-complete loss of hearing sensitivity as displayed by elevated (>90-dB sound pressure levels) auditory brainstem response thresholds. The treatment of amikacin-exposed animals with MK801 gave only a partial protection of hearing. However, the combined treatment with NT3 and MK801 in the amikacin-comprised ear resulted in improved mean hearing within 20 dB of normal. Furthermore, hair cell loss was prevented in these animals and spiral ganglion neurons were completely protected. These results suggest that the NMDA antagonist MK801 protects against noise-induced excitotoxicity in the cochlea whereas the combined treatment of NT3 and MK801 has a potent effect on preserving both auditory physiology and morphology against aminoglycoside toxicity.

Synthesis and characterization of the dimethyl-substituted bisbenzimidazole ligand and its manganese complex

Macrocycles with unique properties provide new avenues for the design of novel catalysts and materials. Here, we report, for the first time, the synthesis and characterization of the dimethyl-substituted bisbenzimidazole ligand (Me2BBZ) and its manganese complex (Mn-Me2BBZ). The Me2BBZ ligand is similar to porphyrin and phthalocyanine macrocycles in terms of its cavity size and metal-binding mode, but owing to electronic and charge differences, it exhibits properties that make it distinct from its structural counterparts. For instance, the optical spectra of bisbenzimidazoles lack transitions in the 500-900 nm region. Perhaps the most significant feature of the Me2BBZ ligand, however, is its inherent nonplanarity. Geometric restraints within this nonplanar ligand give rise to two atropisomers, which, when separated, could have potential in chiral catalysis and recognition. In addition, here we show that this nonplanarity can help to promote unusual crystal-packing interactions. Within the structure of the Mn-Me2BBZ complex, intermolecular pi-stacking interactions of the phenyl and benzimidazole groups lead to the formation of a distinct two-dimensional "staircase" lattice comprised of alternating Mn-Me2BBZ atropisomers. The potential significance of this structural arrangement is revealed by temperature-dependent magnetic studies that indicate weak antiferromagnetic coupling between the metal ions in the crystal. Fine-tuning of these long-range electronic and magnetic interactions could be useful for the design of novel molecular materials.

Structural trends in first-row transition-metal bis(benzimidazole) complexes

Dimethyl-substituted bis(benzimidazole) (Me2BBZ) is a novel macrocyclic ligand that possesses an intrinsic nonplanarity. To examine how metal-ion binding affects the magnitude of this nonplanarity, we have determined the structures of a periodic series of Me2BBZ complexes bound to Mn(II), Fe(II), Co(II), Ni(II), and Cu(II). These studies demonstrate that the extent of ligand ruffling and metal doming is indeed influenced by the nature of the metal. Concomitant with the periodic decrease of the ionic radii of the encapsulated divalent metal ion, a decrease in the magnitude of both the ligand nonplanarity and the metal out-of-the-plane distance is observed. For the metal out-of-the-plane distance, this correlation persists until the metal finally moves into the mean ligand plane. For the nonplanar distortion, the extent of the nonplanarity decreases to a limiting value that is intrinsic to the Me2BBZ ligand due to steric factors. These observations indicate that the relative sizes of the metal ion and the Me2BBZ ligand cavity have profound effects on the structural features of the metal-ligand complex.

One-stage pedicled omentum majus transplantation into thoracic cavity for treatment of chronic persistent empyema with or without bronchopleural fistula

OBJECTIVE

Assessment of the present results of surgical treatment for chronic persistent empyema with or without bronchopleural fistula (BPF) using one-stage pedicled omentum majus transplantation into the thoracic cavity.

METHODS

From November 1979 to December 1996, 50 patients with chronic persistent empyema were treated by pedicled omentum majus transplanted into the thoracic cavity. There were 35 men and 15 women, and the age range was 15-58 years. Empyema had been present for 0.5-18 years. Twenty-six of 35 cases with chronic tuberculous empyema and six of 15 cases with chronic bacterial empyema suffered from concomitant BPF (n = 32). In the latter, the most common organisms were Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli.

RESULTS

There were no perioperative deaths. Two cases had a significant air leak on the first postoperative day. One of them underwent rethoractomy 30 h after the initial operation to stop the fistula using intrathoracic omentum. Thoracic dead space disappeared in most of the operated cases and a sterilized dry cavity remained in some cases.

CONCLUSIONS

One-stage pedicled omentum majus transposition is a safe and easy procedure for chronic persistent empyema and BPF, it breaks down residual or recurrent inflammatory foci mechanically and closes the BPF effectively with minimal deformity of the chest wall.

Neurotrophins, NMDA receptors, and nitric oxide in development and protection of the auditory system

Neurotrophic factors are secreted peptides that when interacting with specific classes of membrane receptors activate intracellular signaling cascades that prevents neuronal death during embryonic development. The establishment of gene-targeted null mutant mice for the neurotrophic factors, brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT3) has led to the discovery that they are crucial trophic factors for the survival of auditory and vestibular neurons during development. BDNF is the major survival factor for vestibular ganglion neurons, while NT-3 only support a small number of these neurons. In the cochlea, auditory type I neurons require NT3 for their survival, whereas type II neurons depend on BDNF. With this information at hand recent progress has been made regarding the prevention of aminoglycoside-induced hearing loss in the adult guinea pig. These results and the mechanisms leading to hair cell damage are discussed in this paper.

Factors involved in the neuronal death during postischemic reperfusion: experimental study in rabbits

OBJECTIVE

To explore the main pathogenic factors in the development of neuronal death during normothermic reperfusion in rabbits.

METHODS

Ninety-six New Zealand rabbits were randomly allocated into two groups: group I served as non-ischemic controls; group II served as postischemic normothermic reperfusion models. Complete cerebral ischemia was induced by the four-vessel model for 30 minutes. After ischemia, rabbits in group II were further divided into three subgroups according to the duration of reperfusion: subgroup A, 30 minutes; subgroup B, 180 minutes and subgroup C, 360 minutes. Twenty-eight biochemical parameters in the brain were measured, and neuronal changes were observed by histomorphological assessment. Neurons of 12 regions were differentiated into four types: type A (normal), type B (mildly damaged), type C (severely damaged) and type D (necrotic). Bivariate correlate analysis between the levels of biochemical parameters and the percentages of each type of neurons was carried out.

RESULTS

The main parameters involved in the progressive decrement of type A neurons were VIP, beta-EP, PGI2, T3, T4 and Na+, K(+)-ATPase; in the increment of type B were beta-EP and TXB2; in the increment of type C were GLU and TXB2/PGI2 respectively; in the stepwise increment of percentages of type D neurons were T4, Na+, K(+)-ATPase, GLU, T3 and VIP (P < 0.05).

CONCLUSION

The main factors involved in the development of neuronal death during postischemic normothermic reperfusion in rabbits include hypermetabolism, deactivation of Na+, K(+)-ATPase, release of excitatory amino acids and disorder of neuropeptides.

[Analysis of rice leaf proteins induced by Magnaporthe grisae with capillary zone electrophoresis]

Intercellular and intracellular proteins which were extracted from rice seedling leaves induced by Magnaporthe grisae, as well as those of control, were analysed by capillary zone electrophoresis. Intercellular proteins were extracted with sterilized water, while intracellular proteins were extracted with acidic protein extraction buffer. Protein adsorption to capillary wall was suppressed by using linear polyacrylamide coated capillary (75 microns x 57 cm) instead of uncoated capillary. Separations were performed at 25 degrees C with a positive voltage of 20 kV. Samples were injected into the capillary by applying pressure (3.0 kPa) for 5 s. The running buffer consisted of 50 mmol/L phosphoric acid (pH 2.0), and detection was achieved at 200 nm with a diode array detector. Being compared with a control, a new kind of protein induced by Magnaporthe grisae was identified in rice leaf intracellular proteins with Grubbs method which is used to test outliers in mathematical statistics.

Effects of selective head cooling on brain cell membrane activity during postischemic reperfusion

OBJECTIVE

To examine the effect of selective head cooling (SHC) on brain cell membrane activity involving ATPase, phospholipase A2, content of total membrane phospholipids during postischemic reperfusion, so as to elucidate the possible underlying mechanism on resuscitating effect of SHC.

MATERIALS AND METHODS

Complete cerebral ischemia (CCI) was induced by the four-vessel model. 56 New Zealand rabbits were allocated randomly into two groups, non-ischemic control group had 30, 180 and 360 minutes reperfusion after CCI (n = 8); and SHC group with the same ischemic-reperfusion insult were all treated with SHC (28 degrees C, surface cooling method). Changes of Na+, K(+)-ATPase, Ca2+, Mg(2+)-ATPase, phospholipase A2, total phospholipids of brain cell membrane were observed. Comparison of data between two groups was made by Students' t test.

RESULTS

Compared with non-ischemic controls following 30 minutes CCI, activities of Na+, K(+)-ATPase stepwisely decreased at 30, 180 and 360 minutes, Ca2+, Mg(2+)-ATPase dropped at 180 and 360 minutes, phospholipidase A2 increased markedly at 30, 180, 360 minutes, and total phospholipids decreased at 180 and 360 minutes reperfusion (P < 0.01). Selective head cooling inhibited all the above changes significantly (P < 0.01).

CONCLUSION

The results suggest that selective head cooling initiated soon after reperfusion is beneficial for brain cell membrane function recruitment, which provides favourable effects on the damaged but still remediable brain cells for their resuscitation.