Non-function of a Moloney murine leukaemia virus regulatory sequence in F9 embryonal carcinoma cells

Moloney murine leukaemia virus (M-MuLV) infection of embryonal carcinoma (EC) cells results in the integration of proviral DNA into the host cell genome, but not in virus production. One suggested explanation for the lack of viral gene expression in EC cells has been methylation of the integrated viral DNA. However, subsequent reports indicated that integration of the M-MuLV DNA occurs soon after infection, but that viral DNA methylation occurs considerably later. Nevertheless, viral gene expression is not observed even at early times. One possible explanation is that certain M-MuLV regulatory sequences do not function in EC cells. We now present evidence which supports this hypothesis.

Clinical trial of fluoride therapy in postmenopausal osteoporotic women: extended observations and additional analysis

In a 4 year clinical trial in 202 postmenopausal osteoporotic women receiving NaF at 75 mg/day or placebo (both groups received supplementary calcium at 1500 mg/day), we found (N Engl J Med 322:801, 1990) that NaF increased bone mineral density in the lumbar spine (LS-BMD) substantially but did not decrease vertebral fracture rate (VFR), and it increased the nonvertebral fracture rate. Additional analyses and extended observations are now available on 50 women from the NaF group followed for up to 6 years of treatment. In these women, LS-BMD increased linearly over the 6 years (median rate, 8.7%/year or 0.063 g/cm2/year). Because during the 4 year trial the NaF dosage was decreased (because of side effects) in 54 of the 101 women randomized to NaF, dose-response relationships could be evaluated. For the entire study population, serum F level correlated directly with increase in LS-BMD (r = 0.61, P < 0.001). When individual person-years of observation were grouped by deciles of LS-BMD, VFR (per 100 person-years) decreased to a nadir of 24 as mean LS-BMD for the group increased from 0.6 to 1.2 g/cm2 and then doubled to 52 in the group with mean LS-BMD of 1.6 g/cm2. Multivariate analyses and inspection of three-dimensional plots revealed a complex pattern in which VFR was influenced by interaction of several variables. When the effects of LS-BMD, changes in LS-BMD, and serum F were assessed simultaneously, VFR was seen to decrease with increasing LS-BMD except when the higher LS-BMD was associated with rapid rate of increase in LS-BMD or a large increase from baseline serum F. For some patients (noncompliers or nonresponders), serum F or LS-BMD failed to increase. Thus, it is possible that lower dosages of NaF produce moderate decreases in VFR.

A novel reconstruction algorithm to extend the CT scan field-of-view

For various reasons, a projection dataset acquired on a computed tomography (CT) scanner can be truncated. That is, a portion of the scanned object is positioned outside the scan field-of-view (SFOV) and the line integrals corresponding to those regions are not measured. A projection truncation problem causes imaging artifacts that lead to suboptimal image quality. In this paper, we propose a reconstruction algorithm that enables an adequate estimation of the projection outside the SFOV. We make use of the fact that the total attenuation of each ideal projection in a parallel sampling geometry remains constant over views. We use the magnitudes and slopes of the projection samples at the location of truncation to estimate water cylinders that can best fit to the projection data outside the SFOV. To improve the robustness of the algorithm, continuity constraints are placed on the fitting parameters. Extensive phantom and patient experiments were conducted to test the robustness and accuracy of the proposed algorithm.

Panel-based testing for inherited colorectal cancer: a descriptive study of clinical testing performed by a US laboratory

Next-generation sequencing enables testing for multiple genes simultaneously (‘panel-based testing’) as opposed to sequential testing for one inherited condition at a time (‘syndrome-based testing’). This study presents results from patients who underwent hereditary colorectal cancer (CRC) panel-based testing (‘ColoNext™’). De-identified data from a clinical testing laboratory were used to calculate (1) frequencies for patient demographic, clinical, and family history variables and (2) rates of pathogenic mutations and variants of uncertain significance (VUS). The proportion of individuals with a pathogenic mutation who met national syndrome-based testing criteria was also determined. Of 586 patients, a pathogenic mutation was identified in 10.4%, while 20.1% had at least one VUS. After removing eight patients with CHEK2 mutations and 11 MUTYH heterozygotes, the percentage of patients with ‘actionable’ mutations that would clearly alter cancer screening recommendations per national guidelines decreased to 7.2%. Of 42 patients with an ‘actionable’ result, 30 (71%) clearly met established syndrome-based testing guidelines. This descriptive study is among the first to report on a large clinical series of patients undergoing panel-based testing for inherited CRC. Results are discussed in the context of benefits and concerns that have been raised about panel-based testing implementation.

Conflict of interest

Cristi Radford and Jill Dolinsky are full-time employees for the commercial laboratory Ambry Genetics, which performs ColoNext™ testing. Elizabeth Chao is a paid consultant for Ambry. Deborah Cragun, Meghan Caldwell, and Tuya Pal report no potential conflicts of interest. Specifically, they are not employed by Ambry, and they did not receive any financial or other incentives from Ambry.

Fast nastic motion of plants and bioinspired structures

The capability to sense and respond to external mechanical stimuli at various timescales is essential to many physiological aspects in plants, including self-protection, intake of nutrients and reproduction. Remarkably, some plants have evolved the ability to react to mechanical stimuli within a few seconds despite a lack of muscles and nerves. The fast movements of plants in response to mechanical stimuli have long captured the curiosity of scientists and engineers, but the mechanisms behind these rapid thigmonastic movements are still not understood completely. In this article, we provide an overview of such thigmonastic movements in several representative plants, including Dionaea, Utricularia, Aldrovanda, Drosera and Mimosa. In addition, we review a series of studies that present biomimetic structures inspired by fast-moving plants. We hope that this article will shed light on the current status of research on the fast movements of plants and bioinspired structures and also promote interdisciplinary studies on both the fundamental mechanisms of plants' fast movements and biomimetic structures for engineering applications, such as artificial muscles, multi-stable structures and bioinspired robots.

Construction and characterization of Moloney murine leukemia virus mutants unable to synthesize glycosylated gag polyprotein

Murine leukemia virus (MuLV) encodes two independent pathways for expression of the gag gene. One pathway results in processing and cleavage of the precursor Pr65gag to yield the internal capsid proteins of the virion and is analogous to gag polyprotein precursors for all classes of retroviruses. The other pathway, which is not encoded by several other classes of retroviruses, begins with a glycosylated polyprotein gPr80gag . gPr80gag is synthesized independently of Pr65gag; it contains Pr65gag peptides and additional amino-terminal protein. It is modified by further addition of carbohydrate, exported to the cell surface, and released from the cell but does not appear in virus particles. To investigate the role of glycosylated gag in MuLV infection, two mutants of Moloney MuLV (M-MuLV) deficient for synthesis of gPr80gag but able to synthesize Pr65gag were constructed. The mutants were obtained by substitution into a molecular clone of M-MuLV DNA by DNA from two acutely transforming viruses, Ableson MuLV (Ab-MuLV) and Moloney murine sarcoma virus (M-MSV). Both Ab-MuLV and M-MSV are derived from M-MuLV and they express M-MuLV gag sequences, but some strains do not synthesize glycosylated gag protein. For Ab-MuLV, a 177-base-pair Pst I fragment from the P90 strain containing the initiation codon for Pr65gag was substituted for the equivalent fragment in M-MuLV DNA. For M-MSV, 1.5 kilobases at the 5' end of the genome was substituted. Transfection of the recombined DNAs onto NIH-3T3 cells produced infectious M-MuLV, although the infected cells did not produce gPr80gag. Therefore glycosylated gag is not absolutely required for MuLV replication. Deletion of the glycosylated gag pathway did not significantly reduce the level of virus production, although a minor difference in XC plaque morphology was observed.

Costs of staged versus simultaneous bilateral total knee arthroplasty: a population-based study of the Taiwanese National Health Insurance Database

Background

Bilateral total knee arthroplasty (TKA) is required for many patients. There are few studies comparing the overall costs of staged and simultaneous bilateral TKA.

Methods

The Taiwan National Health Insurance Research Database (NHIRD) was searched, and the total medical costs of 452 patients who received simultaneous bilateral TKAs were compared with those of 690 who received staged bilateral TKAs.

Results

All categories of medical costs were lower in the simultaneous TKA group, with the exception of therapeutic procedure fees which were higher in the simultaneous bilateral TKA group. The 10-year prosthesis survival rates for simultaneous and staged bilateral TKA were 90.9% and 87.5% (p > 0.05), respectively.

Conclusions

These results indicate that simultaneous bilateral TKA is more cost effective than staged bilateral TKA. Prosthesis survival is not affected by the choice for staged or simultaneous bilateral TKA.

Measurement of vertebral area on spine x-rays in osteoporosis: reliability of digitizing techniques

Much of the clinical research in osteoporosis is directed toward documenting a reduction in vertebral fracture rate, but there is considerable disagreement about defining and quantifying vertebral fractures. We have evaluated the technique of digitizing landmarks identified on lateral radiographs of thoracic and lumbar vertebrae and computing vertebral body area. Reduction in area indicates that fractures occurred. Radiographs from 10 patients with osteoporosis and vertebral fractures were obtained from each of two centers. Henry Ford Hospital (HFH) and Mayo Clinic (MC), and vertebral area for each individual in the complete set of 20 radiographs was calculated at each center. Measurements at the two centers differed by a multiplicative constant related to the method of recording landmarks on the radiographs that was estimated using 300 x-rays from HFH. After adjusting the MC areas for this multiplicative relationship, the average ratio of the HFH areas to the transformed MC areas of individual vertebrae (T4-L5) ranged from 0.98 to 1.06. The correlation between HFH and transformed MC areas for individual vertebrae averaged 0.85, with slopes between 0.87 and 1.00, intercept average -0.57. Within-patient rank correlation averaged 0.97. We conclude that radiographic digitization is a reliable and reproducible method of determining vertebral body dimensions that is suitable for evaluating radiographs obtained at different clinical sites and for comparison with normal data. This technique should prove useful for documenting the presence of a vertebral fracture that may not be readily apparent on visual inspection of radiographs and for monitoring serial changes in vertebral body dimensions in long-term epidemiologic and therapeutic studies.

Rearrangements and insertions in the Moloney murine leukemia virus long terminal repeat alter biological properties in vivo and in vitro

The effects of rearrangement and insertion of sequences in the Moloney murine leukemia virus (M-MuLV) long terminal repeat (LTR) were investigated. The alterations were made by recombinant DNA manipulations on a plasmid subclone containing an M-MuLV LTR. Promoter activity of altered LTRs was measured by fusion to the bacterial chloramphenicol acetyltransferase gene, followed by transient expression assay in NIH 3T3 cells. M-MuLV proviral organizations containing the altered LTRs were also generated, and infectious virus was recovered by transfection. Infectivity of the resulting virus was quantified by XC plaque assay, and pathogenicity was determined by inoculating neonatal NIH Swiss mice. Inversion of sequences in the U3 region containing the tandemly repeated enhancer sequences (-150 to -353 base pairs [bp]) reduced promoter activity approximately fivefold in the transient-expression assays. Infectious virus containing the inverted sequences (Mo- M-MuLV) showed a 20-fold reduction in relative infectivity compared with wild-type M-MuLV, but the virus still induced thymus-derived lymphoblastic lymphoma or leukemia in mice, with essentially the same kinetics as for wild-type M-MuLV. We previously derived an M-MuLV which carried inserted enhancer sequences from the F101 strain of polyomavirus (Mo + PyF101 M-MuLV) and showed that this virus is nonleukemogenic. In Mo + PyF101 M-MuLV, the PyF101 sequences were inserted between the M-MuLV promoter and the M-MuLV enhancers (at -150 bp). A new LTR was generated in which the PyF101 sequences were inserted to the 5' side of the M-MuLV enhancers (at -353 bp, PyF101 + Mo M-MuLV). The PyF101 + Mo LTR exhibited promoter activity similar (40 to 50%) to that of wild-type M-MuLV, and infectious PyF101 + Mo M-MuLV had high infectivity on NIH 3T3 cells (50% of wild type). In contrast to the nonleukemogenic Mo + PyF101 M-MuLV, PyF101 + Mo M-MuLV induced leukemia with kinetics similar to that of wild-type M-MuLV. Thus, the position of the PyF101 sequences relative to the M-MuLV LTR affected the biological behavior of the molecular construct. Furthermore, PyF101 + Mo M-MuLV induced a different spectrum of neoplastic disease. In comparison with wild-type M-MuLV, which induces a characteristic thymus-derived lymphoblastic lymphoma with extremely high frequency, PyF101 + Mo M-MuLV was capable of inducing both acute myeloid leukemia or thymus-derived lymphoblastic lymphoma, or both. Tumor DNA from both the PyF101 + Mo- and Mo- M-MuLV-inoculated animals contained recombinant proviruses with LTRs that differed from the initially inoculated virus.

Factors associated with methadone treatment duration: a Cox regression analysis

This study examined retention rates and associated predictors of methadone maintenance treatment (MMT) duration among 128 newly admitted patients in Taiwan. A semi-structured questionnaire was used to obtain demographic and drug use history. Daily records of methadone taken and test results for HIV, HCV, and morphine toxicology were taken from a computerized medical registry. Cox regression analyses were performed to examine factors associated with MMT duration. MMT retention rates were 80.5%, 68.8%, 53.9%, and 41.4% for 3, 6, 12, and 18 months, respectively. Excluding 38 patients incarcerated during the study period, retention rates were 81.1%, 73.3%, 61.1%, and 48.9% for 3 months, 6 months, 12 months, and 18 months, respectively. No participant seroconverted to HIV and 1 died during the 18-months follow-up. Results showed that being female, imprisonment, a longer distance from house to clinic, having a lower methadone dose after 30 days, being HCV positive, and in the New Taipei city program predicted early patient dropout. The findings suggest favorable MMT outcomes of HIV seroincidence and mortality. Results indicate that the need to minimize travel distance and to provide programs that meet women's requirements justify expansion of MMT clinics in Taiwan.

Leukemogenicity of Moloney murine leukemia viruses carrying polyoma enhancer sequences in the long terminal repeat is dependent on the nature of the inserted polyoma sequences

The leukomogenicity of Moloney murine leukemia virus (M-MuLV) variants with chimeric long terminal repeats (LTRs) containing sequences from polyomavirus was studied. We previously showed that insertion of the B enhancer element from the PyF101 variant into the M-MuLV LTR between the M-MuLV enhancers and promoter abolished leukemogenicity. PyF101 differs from wild-type polyoma in that it can productively infect undifferentiated F9 embryonal carcinoma cells; this is due to alterations in the B enhancer element. Two additional chimeric M-MuLVs were generated that contained the B enhancers from wild-type polyoma and also from a second host range variant (PyF441), which differs from wild-type polyoma by only a single base change. In contrast to Mo+PyF101 M-MuLV, both Mo+Pywt and Mo+-PyF441 M-MuLV induced T-lymphoid leukemia in neonatal NIH Swiss mice with the same time course as wild-type M-MuLV. Thus the lack of leukemogenicity of Mo+PyF101 M-MuLV was related to the exact nature of the PyF101 B enhancers. While both Mo+Pywt and Mo+PyF441 M-MuLVs induced leukemia, they showed differences when the resulting tumors were examined. First, approximately one-third of the tumors induced by Mo+Pywt M-MuLV contained proviruses which lacked polyoma sequences, while all of the tumors induced by Mo+PyF441 M-MuLV contained proviruses with the chimeric LTR. Second, a majority of tumors induced by Mo+Pywt M-MuLV (and also wild-type, M-MuLV) showed proviral integrations near one or more of the cellular c-myc, pim-1, or pvt-1 loci. In contrast, tumors induced by Mo+PyF441 M-MuLV showed infrequent integrations at these loci.

Effects of intensive insulin therapy alone and with added pioglitazone on renal salt/water balance and fluid compartment shifts in type 2 diabetes

OBJECTIVE

To evaluate the effects of intensive insulin therapy alone or with added pioglitazone on renal salt/water balance and body fluid compartment shifts in type 2 diabetes.

METHODS

A total of 25 insulin-treated, obese patients with type 2 diabetes were randomized to pioglitazone 45 mg (n = 12) or placebo (n = 13) and treated intensively for 12-16 weeks to achieve equivalent glycaemic control. We measured total body water (TBW) and extracellular/intracellular fluid by bioimpedance analysis; plasma/RBC volume with I(131)albumin; sodium handling by fractional excretion of sodium/lithium (FeNa/FeLi) and other renal/hormonal parameters.

RESULTS

Intensification of insulin therapy and the addition of pioglitazone significantly improved glycaemia (HbA1C 7.8-7.2% and 7.6-7.1%) and increased body weight (1.7 and 4.9 kg) respectively. TBW increased 1.7 l with insulin alone (65% intracellular) and 1.6 l with added pioglitazone (75% extracellular) (p = 0.06 and 0.09 respectively). Plasma volume increased 0.2 +/- 0.1 l with insulin alone (p = 0.05) and 0.4 +/- 0.1 l with added pioglitazone (p < 0.05). Extravascular, extracellular (interstitial) fluid increased significantly and more with added pioglitazone (0.8 +/- 0.2 l, p < 0.01) than with insulin alone (0.4 +/- 0.2 l, p = ns). At steady-state, FeLi (marker of proximal-tubular sodium delivery to the distal nephron) increased significantly with added pioglitazone (12.4 +/- 1.3 to 18.0 +/- 3.2%) vs. no significant change with insulin alone (15.4 +/- 1.2 to 14.5 +/- 2.3%). There were no significant changes in the other parameters.

CONCLUSION

In intensively insulin-treated obese type 2 diabetic patients, at equivalent glycaemic control, the addition of pioglitazone causes greater weight gain, but a similar increase in body water that is mainly extracellular and interstitial compared with intracellular increase with insulin therapy alone. Pioglitazone also increases the filtered load of sodium reabsorbed at the distal nephron with no net change in FeNa.

Machine Learning Algorithms to Predict In-Hospital Mortality in Patients with Traumatic Brain Injury

Traumatic brain injury (TBI) can lead to severe adverse clinical outcomes, including death and disability. Early detection of in-hospital mortality in high-risk populations may enable early treatment and potentially reduce mortality using machine learning. However, there is limited information on in-hospital mortality prediction models for TBI patients admitted to emergency departments. The aim of this study was to create a model that successfully predicts, from clinical measures and demographics, in-hospital mortality in a sample of TBI patients admitted to the emergency department. Of the 4881 TBI patients who were screened at the emergency department at a high-level first aid duty hospital in northern Taiwan, 3331 were assigned in triage to Level I or Level II using the Taiwan Triage and Acuity Scale from January 2008 to June 2018. The most significant predictors of in-hospital mortality in TBI patients were the scores on the Glasgow coma scale, the injury severity scale, and systolic blood pressure in the emergency department admission. This study demonstrated the effective cutoff values for clinical measures when using machine learning to predict in-hospital mortality of patients with TBI. The prediction model has the potential to further accelerate the development of innovative care-delivery protocols for high-risk patients.

Effectiveness of traditional Chinese medicine in Alzheimer disease

Effects of traditional Chinese medicine on dementia, P300, cerebral blood flow, and cerebrospinal fluid (CSF) examination were investigated. Ten patients with Alzheimer disease (AD) who agreed to take traditional Chinese medicine were studied. The traditional Chinese medicine was given for 3 months and the Mini-Mental State Examination (MMSE), P300 examination, cerebral blood flow examination, and CSF examination were performed before and after taking the traditional Chinese medicine. The scores of the MMSE, the P300 latency, and blood flow in the cerebral cortex in AD improved with treatment with the traditional Chinese medicine. The concentration of alpha-aminobutyric acid in the CSF decreased with treatment with the traditional Chinese medicine. The improvement is considered to be not a placebo effect. Key Words: T

Comparison of total hip and knee joint replacement in patients with rheumatoid arthritis and osteoarthritis: a nationwide, population-based study

INTRODUCTION

Patients with rheumatoid arthritis (RA) and osteoarthritis (OA) may require total hip replacement (THR) or total knee replacement (TKR). The present study aimed to compare the demographic characteristics and medical costs of RA and OA patients from Taiwan who underwent either THR or TKR.

METHODS

The medical records of patients who had undergone THR or TKR from 1 January 1996 to 31 December 2010 were obtained from the Taiwan National Health Insurance Research Database (NHIRD). In all, we found 49 and 146 RA patients who received THR and TKR, respectively, and 1,191 and 6,574 OA patients who received THR and TKR, respectively. The gender, age, Charlson comorbidity index (CCI), hospital grade, age at registration in the catastrophic illness dataset, and medical utilisation costs of the different groups were compared.

RESULTS

There were statistically significant differences in age, CCI score, drug costs and surgery costs between RA and OA patients. Joint replacement incidence was lower in RA patients than in OA patients, and among patients who underwent THR, total medical costs incurred were higher for RA patients than OA patients. RA patients who underwent THR incurred a significantly greater total medical utilisation cost in the outpatient department (3 months before surgery and 12 months after surgery) than OA patients who underwent THR.

CONCLUSION

Analysis of Taiwan NHIRD with regard to patients who had undergone either THR or TKR indicated that RA patients were younger than OA patients, and that significantly more medical resources were used for RA patients before, during and after hospitalisation for these procedures.

Seasonal variation of vitamin A (retinol) status in older men and women

OBJECTIVE

The present study was undertaken to determine vitamin A status in 59 free-living (26 males, 33 females) healthy older persons (65-74 years) in winter and summer.

DESIGN

Three-day dietary intake data for vitamin A along with carbohydrate, lipid and protein were collected during the summer (June-September) and again during the winter (November-March). In addition, retinol and its carrier proteins, retinol-binding protein (RBP) and transthyretin (TTR), were measured in the plasma in each season.

RESULTS

The mean vitamin A intake met the Canadian Recommended Intake (RNI) for both gender and season. However, probability analysis of dietary data revealed that 7 and 11% of males, and 8 and 14% of females, in summer and winter, respectively, were at risk of deficiency. None of the subjects in the present study exhibited biochemical evidence of vitamin A deficiency as determined by plasma levels of retinol and its transport proteins. Overall, the mean intake of vitamin A was significantly higher in males than in females; no seasonal effect was observed. On the other hand, the plasma levels of retinol and its carrier proteins were significantly lower in winter season than in summer, without any gender variation effect.

CONCLUSION

Although mean values for dietary intake and plasma concentration of vitamin A may indicate nutritional adequacy, a small proportion of an older population may be at nutritional risk. The prevalence of risk appears to be generally higher in the winter than in the summer season and in females than in males.

Application of classification criteria of Sjogren syndrome in patients with sicca symptoms: Real-world experience at a medical center

BACKGROUND

Patients who have symptoms of sicca, such as dry eyes and mouth, may have Sjögren's syndrome (SS). However, the conservative culture makes patients hesitate to undergo an invasive biopsy, which contributes to the difficulty of confirming a diagnosis. We aimed to identify the characteristics of patients with sicca symptoms to develop a better predictive value for each item included in the three different diagnostic criteria for SS and clarify the best diagnostic tools for the local population.

METHODS

This is a single-center retrospective case-control study from January 2016 to December 2017. Patients who underwent sialoscintigraphy because of clinical symptoms of xerostomia and xerophthalmia at one medical center were reviewed via the patients' electronic medical records.

RESULTS

Of 515 patients enrolled, the severity of results for sialoscintigraphy and Schirmer's test was correlated with a diagnosis of SS and generated receiver operator characteristic curve. The area under curve (AUC) was 0.603 for positive Schirmer's test, 0.687 for positive anti-Ro/La results, 0.893 for a positive salivary gland biopsy. The AUC was 0.626 and 0.602 for Schirmer's test which is redefined as <10 mm/5 minutes in either eye and according to 2016 the American College of Rheumatology/ European League Against Rheumatism criteria, respectively.

CONCLUSION

Our results indicate the cut-off point for defining a positive test result in the Schirmer's test is worth modified to <10 mm/5 minutes in either eye.

Metaraminol use during spinal anaesthesia for caesarean section: a meta-analysis of randomised controlled trials

INTRODUCTION

During caesarean section, the use of a vasopressor is often required to achieve haemodynamic stability of the parturient. Metaraminol is a vasopressor used in this context in some countries. However, the differences between metaraminol and other vasopressors remain unclear.

METHODS

A search of the PubMed, Cochrane Library, and Embase databases was performed to identify randomised controlled trials comparing the use of metaraminol with other vasopressors during spinal anaesthesia at caesarean section. The selected studies were subjected to meta-analysis and risk-of-bias assessment.

RESULTS

Four randomised, controlled trials met the selection criteria and 409 parturients who underwent an elective caesarean section were included in this meta-analysis. The quality of these trials was good. Metaraminol was associated with higher umbilical arterial pH (standardised mean difference [SMD] 0.82, 95% CI 0.01 to 1.62, P=0.05); a lower incidence of fetal acidosis (RR 0.08, 95% CI 0.01 to 0.63, P=0.02); and a lower incidence of nausea or vomiting (RR 0.16, 95% CI 0.04 to 0.57, P=0.0005) than was ephedrine. Metaraminol resulted in higher umbilical arterial pH (SMD 0.42, 95% CI 0.15 to 0.68, P=0.002) but a higher incidence of reactive hypertension (RR 1.80, 95% CI 1.32 to 2.46, P=0.0002) than did phenylephrine.

CONCLUSION

The results of this study showed that for spinal anaesthesia at elective caesarean section, metaraminol may be a more suitable vasopressor than ephedrine and its effects are at least not inferior to those of phenylephrine.

Characterization of murine hepatoma BW7756. III. Hematological profile of a tumor-associated anemia

A severe anemia develops in recipient C57L/J mice after syngeneic transplantation of the BW7756 murine hepatoma. The tumor undergoes an exponential growth spurt in the 14-21 days post-implantation, accompanied by a parallel increase in serum alpha-fetoprotein levels and a significant decrease of hemoglobin concentration and hematocrit extending to the 28th day. Concomitant with the decreased hematocrit, the blood volume displayed a 10% increase. The blood cell population was generally one of reticulocytosis and leukocytosis. Mild icteric plasma was observed and both "cold" and "warm" antibodies were detected in the sera of tumor-bearing mice. An elevation of IgM was observed by day 7, followed by a depletion of IgG1 and IgG2 throughout the tumor growth period. When RBCs of tumor-bearing mice were compared to those of normal mice, the same degree of osmotic fragility was found. However, the lifespan of the transfused RBC was shorter in tumor-bearing mice than in normal mice (half-life: 2 days vs. 4 days). The data suggest a type of auto-immune hemolytic anemia which is analogous to various hematopoietic disturbances described for murine hosts bearing solid tumors distal to hematopoietic sites.

Using tabletop exercises to evaluate nurses' clinical performance of hazardous materials disaster management: A cross-sectional study

BACKGROUND

Hazardous materials (Hazmat) disaster is a specific event with low probability but may be a heavy burden on public health. Competence in Hazmat disaster emergency management is necessary for nurses who care about mass casualties in the first line, especially for nurses in military hospitals. However, less attention has been paid to evaluation of competence of Hazmat disaster emergency responses using tabletop exercises.

OBJECTIVE

To identify competence in Hazmat disaster emergency response and factors influencing performance on tabletop exercises.

METHODS

A cross-sectional design was employed in this study. Competence of nurses responding to a hazardous materials invasion was evaluated by a tabletop exercise. In each case the "Task Based Checklist" was used for evaluation. Multivariate analysis of covariance was conducted to detect the effects of traditional training on performance in Hazmat disaster tabletop exercises.

RESULTS

A total of 161 nurses were recruited for this study. A checklist with 12 items comprised of two dimensions of disaster management was created and validated (CVI = 0.90). Inter-rater reliability for the evaluators ranged from 0.88 to 1. Performance on Hazmat site control, debris management and individual skills in decontamination were found to be suboptimal. Traditional disaster nursing training had no significant influence either on performance on Hazmat site control or patient care after controlling for differences in education level, age and gender.

CONCLUSIONS

The tabletop exercise is an innovative method for disaster nursing educators seeking to evaluate response competence in Hazmat disaster simulation exercises. It is necessary to consider the characteristics of the participants when designing the training program and educational strategies. Participants from the military hospital were shown to have limited competence in Hazmat disaster emergency management.

Vitamin B12 and folate status of a selected group of free-living older persons

Vitamin B12 and folate status was determined in 50 male and 47 female free-living subjects (65-77 years) in winter and summer. The mean intake calculated from 3-day food records met the Canadian recommended intake (RNI) for both gender and season, however, probability analysis of dietary data revealed a number of subjects at risk of deficiency. Although the mean plasma levels were within the acceptable range for both vitamins, some 9 to 14% of individual subjects had folate plasma levels below normal. Fewer subjects had subnormal plasma vitamin B12 levels. Although mean values for dietary intake and plasma concentration of folate and vitamin B12 may indicate nutritional adequacy, a proportion of an older population may be at nutritional risk.