Anomalous mRNA levels of chromatin remodeling genes in swamp buffalo (Bubalus bubalis) cloned embryos

The swamp buffalo (Bubalus bubalis) is a multi-purpose animal in agriculture that is challenged by extinction due to low reproductive efficiency. Nuclear transfer (NT) has been used to preserve special breeds of buffalo, as well as to increase the number of animals. However, cloned buffalo embryos have impaired development, as in other species. To understand the chromatin remodeling activities in cloned embryos and to improve NT technology, we examined the expression profiles of five genes involved in DNA and histone modifications, DNMT1, DNMT3A, DNMT3B, HAT1 and HDAC1, in single swamp buffalo metaphase II oocytes, NT and in vitro fertilized (IVF) embryos from the two-cell to the blastocyst stage, by quantitative real time RT-PCR. We observed similar expression dynamics for all genes studied in the NT and IVF embryos: relatively constant levels of expression for all genes were found from the MII oocyte up to the eight-cell stage; the levels of mRNA for HAT1 and DNMT3B continued to be stably expressed up to the blastocyst stage; while dramatic increases were seen for DNMT3A and HDAC1. Alternatively, the levels of DNMT1 started to decrease at the eight-cell stage. Despite the similarity in the dynamics of gene expression, dramatic differences in the relative levels of these genes between NT and IVF embryos were observed. The expression levels of all DNA modifying genes were higher in the NT embryos than in the IVF embryos at the eight-cell and blastocyst stages. The genes HDAC1 and HAT1 were also expressed significantly higher at the blastocyst stage in the NT embryos. Our results suggested differences in chromatin remodeling between NT and IVF embryos and that lower levels of DNA passive demethylation and higher levels of DNA de novo methylation occurred in the NT embryos. These observations are novel in the species of buffalo, and may be associated with developmental failure of cloned buffalo embryos due to the transcriptional repression effect of most genes studied here.

6 EXPRESSION PROFILING OF SINGLE BOVINE EMBRYOS REVEALS SIGNIFICANT EFFECTS OF IN VITRO MATURATION, FERTILIZATION AND CULTURE

Cattle and sheep embryos transferred after in vitro production are often afflicted by large offspring syndrome (LOS), which has been correlated with the presence of serum and/or cell co-culture. Previous research indicates that post-fertilization culture affects blastocyst quality and gene expression, and in vitro oocyte maturation and fertilization impact developmental competence. To dissect the effects of in vitro maturation, fertilization, and culture, we compared the expression profiles of single bovine blastocysts generated by: (1) in vitro maturation, fertilization and culture (IVF, n = 15); (2) in vivo maturation, in vivo fertilization, and in vitro culture (IVD, n = 14); and (3) in vivo maturation, fertilization, and development (AI, n = 14). For in vitro culture, the embryos were cultured for 2 days in CR1aa medium with bovine serum albumin (BSA) and then transferred to CR1aa with 10% fetal bovine serum (FBS) with cumulus cells until Day 7, at which time the embryos were vitrified. IVD zygotes were surgically collected from two superovulated Holstein donor cows 24 h post-insemination and cultured in the same system. To conduct expression profiling, total RNA was isolated from individual thawed embryos. The RNA was subjected to three rounds of amplification utilizing a previously adapted and validated T7 linear amplification protocol. Amplified RNA from each embryo and from a standard reference was indirectly labeled with Cy3 or Cy5 by dye swap and hybridized to a custom bovine cDNA microarray containing ~6300 unique genes. After Loess normalization, an ANOVA model (GeneSpring 6.1 and SAS 9.0) was used to identify differentially expressed genes. The P-values were adjusted for multiple comparisons using the false discovery rate approach, and a e2-fold differential criterion was applied. A subset of the differentially expressed genes was verified by real-time RT-PCR. The blastocyst rates for IVF and IVD embryos were 37% and 75%, respectively. There were 305, 365, and 200 genes differentially expressed between the AI and IVD, the IVF and IVD, and the AI and IVF comparisons, respectively. Interestingly, 44 differentially expressed genes were identified between the AI embryos and both the IVF and the IVD embryos, making these potential candidates for LOS. There were 61 genes differentially expressed between the IVF embryos and the AI and IVD embryos. The Gene Ontology categories 'RNA processing' and 'RNA binding' were over-represented among the genes that were down-regulated in the IVF embryos, indicating an effect of in vitro oocyte maturation/fertilization on embryonic gene expression. This work was supported by USDA grants to X.Y., H.A.L., and X.C.T.

Overexpression of aurora B kinase (AURKB) in primary non-small cell lung carcinoma is frequent, generally driven from one allele, and correlates with the level of genetic instability

Aurora kinases are key regulators of chromosome segregation during mitosis. We have previously shown by microarray analysis of primary lung carcinomas and matched normal tissue that AURKB (22 out of 37) and AURKA (15 out of 37) transcripts are frequently over-represented in these tumours. We now confirm these observations in a second series of 44 carcinomas and also show that aurora B kinase protein levels are raised in the tumours compared to normal tissue. Elevated levels of expression in tumours are not a consequence of high-level amplification of the AURKB gene. Using a coding sequence polymorphism we show that in most cases (seven out of nine) tumour expression is predominantly driven from one AURKB allele. Given the function of aurora B kinase, we examined whether there was an association between expression levels and genetic instability. We defined two groups of high and low AURKB expression. Using a panel of 10 microsatellite markers, we found that the group showing the higher level of expression had a higher frequency of allelic imbalance (P=0.0012). Analysis of a number of other genes that are strongly and specifically expressed in tumour over normal lung, including SERPINB5, TERT and PRAME, showed marked allelic expression imbalances in the tumour tissue in the context of balanced or only marginally imbalanced relative allelic copy numbers. Our data support a model of early carcinogenesis wherein defects in the process of inactivation of lung stem-cell associated genes during differentiation, contributes to the development of carcinogenesis.

Impaired parasympathetic response to feeding in ventilated preterm babies

BACKGROUND

Premature very low birthweight (VLBW) infants are born with an underdeveloped parasympathetic nervous system (PNS) which may limit their ability to respond adequately to feeding and may limit their capacities for extrauterine growth and development.

OBJECTIVES

To describe the patterns of autonomic response to feeding and identify relationships between change in heart period variability measures over time with selected infant characteristics.

METHODS

Individual growth curve analysis techniques were used to describe the patterns of change over time in sympathetic and parasympathetic tone as measured by low and high frequency heart period power.

RESULTS

Sixteen mechanically ventilated VLBW infants with a mean corrected gestational age of 30.4 weeks participated in the study. The low frequency (LF) power slope was -17.67 (p = 0.0002) and the high frequency (HF) power slope was -0.92 (0.0003). There was a significant relationship between HF slope and birth gestational age (r = -0.49, p = 0.05).

CONCLUSIONS

HF power, representing primarily parasympathetic activity, did not increase with enteral feeding as anticipated. LF power, an indicator of sympathetic tone, decreased during and after feeding suggesting the anticipated effect of inhibition of the sympathetic nervous system in response to the gut stimulus. Critically ill VLBW infants possess an overriding sympathetic response, but may not have adequate PNS tone development.

S100A2 is strongly expressed in airway basal cells, preneoplastic bronchial lesions and primary non-small cell lung carcinomas

S100A2 gene products were shown to be frequently and dramatically over-represented in non-small cell lung cancer (NSCLC) lesions over normal tissue by microarray analysis. We have now analysed an independent series of NSCLC tumours and multiple matched normal bronchial epithelial sites by RT–PCR and immunohistochemistry to investigate: whether this expression pattern can be confirmed and whether elevated expression is associated with tumour histology, clinical outcome or preneoplasia. In this second series, S100A2 was strongly expressed in 76% (35 out of 46) of tumours, more frequently in squamous cell than adenocarcinomas (P<0.002). This strong expression was not related to high-level gene amplification, but was associated in one of five informative cases with an allele-specific imbalance in transcript levels. Most tumours strongly expressed the ΔNp63 transcript, the product of which is a putative regulator of S100A2 transcription and while all but one of the tumours positive for ΔNp63 expressed S100A2, others negative for this regulator also expressed the gene. Contrary to the hypothesis that S100A2 is a tumour suppressor, no somatic mutations were identified in the coding sequence in 44 tumours. Furthermore, an examination of multiple tumour-free epithelial sites from 20 patients showed that strong expression was often associated with increasing levels of disorder in preinvasive bronchial lesions (P<0.0001).

Imaging of pancreatic adenocarcinoma with emphasis on multidetector CT

Pancreatic adenocarcinoma is the fourth most frequent cause of cancer-related death. The incidence is increasing and the overall survival has altered little in recent years. Moreover, patients usually present late with inoperable disease and curative resection by standard pancreatico-duodenectomy (Whipple's procedure) is associated with significant morbidity. It should only be attempted in that small group of patients lacking radiological evidence of advanced disease. Despite the recent advances in body magnetic resonance imaging (MRI) and endoscopic ultrasound (EUS), computed tomography (CT) is the mainstay of staging in most centres and the recent development of multidetector CT machines (MDCT) has raised hope of an improvement in preoperative staging. This review focuses on the CT of pancreatic adenocarcinoma with particular emphasis on examination technique and on those criteria that determine resectability.

Developing a neonatal workforce: role evolution and retention of advanced neonatal nurse practitioners

BACKGROUND

Over the past decade more than 120 advanced neonatal nurse practitioners (ANNPs) have graduated from the Southampton based ANNP programme.

OBJECTIVES

To determine the scope of practice and evolving role of ANNPs and to identify factors that may affect future recruitment and retention.

METHOD

An open ended structured questionnaire on clinical role, working arrangements, retention and attrition, continuing education, and professional development was sent to 95 ANNPs.

RESULTS

A response rate of 83% was achieved. There was an attrition rate of 14%, with most ANNPs remaining in their original seconding unit. Factors considered to be important for role satisfaction included a well defined role, working within a team of ANNPs, appropriate remuneration, and evidence of unit support for both role definition and continuing professional development.

CONCLUSIONS

Although ANNPs are expensive to both train and employ, this evidence suggests that there is a good return on the investment in terms of retention to the unit and the specialty. Their role incorporates many features of advanced nursing practice as well as providing "value added" neonatal care by merging traditional medical and nursing roles and crossing professional boundaries. In 2004 the manpower challenges for neonatal units will be even more acute; these data confirm that there are effective options available but they require long term strategic planning and investment.

Decreased endothelin receptor B expression in large primary uveal melanomas is associated with early clinical metastasis and short survival

The most devastating aspect of cancer is the metastasis of tumour cells to organs distant from the original tumour site. The major problem facing oncologists treating uveal melanoma, the most common cancer of the eye, is metastatic disease. To lower mortality, it is necessary to increase our understanding of the molecular genetic alterations involved in this process. Using suppression subtractive hybridisation, we have analysed differential gene expression between four primary tumours from patients who have developed clinical metastasis and four primary tumours from patients with no evidence of metastasis to date. We have identified endothelin receptor type B as differentially expressed between these tumours and confirmed this observation using comparative multiplex RT-PCR. In a further 33 tumours, reduced endothelin receptor type B expression correlated with death from metastatic disease. Reduced expression also correlated with other known prognostic indicators, including the presence of epithelioid cells, chromosome 3 allelic imbalance and chromosome 8q allelic imbalance. Endothelin receptor type B expression was also reduced in four out of four primary small cell lung carcinomas compared to normal bronchial epithelium. We also show that the observed down-regulation of endothelin receptor type B in uveal melanoma was not due to gene deletion. Our findings suggest a role for endothelin receptor type B in the metastasis of uveal melanoma and, potentially, in the metastasis of other neural crest tumours.

High efficiency electroporation of human umbilical cord blood CD34+ hematopoietic precursor cells

Human umbilical cord blood provides an alternative source of hematopoietic cells for purposes of transplantation or ex vivo genetic modification. The objective of this study was to evaluate electroporation as a means to introduce foreign genes into human cord blood CD34+ cells and evaluate gene expression in CD34+/CD38(dim) and committed myeloid progenitors (CD33+, CD11b+). CD34+ cells were cultured in X-VIVO 10 supplemented with thrombopoietin, stem cell factor, and Flt-3 ligand. Electroporation efficiency and cell viability measured by flow cytometry using enhanced green fluorescent protein (EGFP) as a reporter indicated 31% +/- 2% EGFP+ /CD34+ efficiency and 77% +/- 3% viability as determined 48 hours post-electroporation. The addition of allogeneic cord blood plasma increased the efficiency to 44% +/- 5% with no effect on viability. Of the total CD34+ cells 48 hours post-electroporation, 20% were CD38(dim)/EGFP+. CD34+ cells exposed to interleukin-3, GM-CSF and G-CSF for an additional 11 days differentiated into CD33+ and CD11b+ cells, and 9% +/- 3% and 8% +/- 7% were expressing the reporter gene, respectively. We show that electroporation can be used to introduce foreign genes into early hematopoietic stem cells (CD34+/CD38(dim)), and that the introduced gene is functionally expressed following expansion into committed myeloid progenitors (CD33+, CD11b+) in response to corresponding cytokines. Further investigation is needed to determine the transgene expression in functional terminal cells derived from the genetically modified CD34+ cells, such as T cells and dendritic cells.

An in vitro wear study of alumina-alumina total hip prostheses

Four 28 mm diameter alumina-alumina hip prostheses were tested in the Mkll Durham hip simulator for 5 x 10(6) cycles using 25 per cent bovine serum as lubricant. Wear of the heads and cups was measured gravimetrically. The mean and standard deviation of the wear rate for the alumina cups was 0.097 +/- 0.039 mm3/10(6) cycles. The femoral heads produced such low wear that it could not be measured by weighing but could be detected byincreased surface roughness measurements. Such low wear rates represent about one-five-hundredthof the wear of ultra-high molecular weight polyethylene (UHMWPE) against ceramic in a similar test and supports work which indicates that fluid film lubrication exists in these joints.

Demographic and occupational effects on the activity levels of normal subjects in the United Kingdom

A study of activity levels, measured in steps per day, was made of 293 subjects from several parts of the United Kingdom. Each subject wore a pedometer adjacent to the hip for two weeks. The average number of steps taken each day over a two-week period was recorded together with additional details such as age and occupation. A general decline in activity with age was observed, which varied slightly for men and women. At twenty years of age the sample of men typically walked about 9,000 steps per day and women 9,200 steps per day, declining to 6,100 and 5,750 steps per day for men and women respectively at sixty years of age. Activity was observed to vary considerably from day to day and was more pronounced for men. The mean number of steps per day for a wide range of occupational groups varied from around 4,500 steps per day for retired persons to 12,700 steps per day for postmen. The activity data was re-analysed to remove the influence of age and gender. The activity of most occupational groups then fell within a relatively narrow range of approximately 7,700 to 8,850 steps per day. The exceptions to this were postmen, nurses and technicians, with averages of 12,750, 9,950 and 9,900 steps per day respectively, and software programmers averaging only 5,250 steps per day. Activity levels for groups of subjects from different parts of the United Kingdom were compared, including Leeds and Bradford, Belfast, Teesside, County Durham and Edinburgh. When the number of subjects in each group was sufficiently large with a wide spread of ages and occupational types, it was found that demography had little effect upon the level of activity. This study provides a substantial new database, based on the UK population. In addition, the assumption that one million cycles in vitro is equivalent to one year in vivo is well supported and relevant to simulator studies. (Hip International 2002; 1: 28-36).

Location of death in Canada. A comparison of 20th-century hospital and nonhospital locations of death and corresponding population trends

This report compares 20th-century Canadian hospital and nonhospital location-of-death trends and corresponding population mortality trends. One of the chief findings is a hospitalization-of-death trend, with deaths in hospital peaking in 1994 at 80.5% of all deaths. The rise in hospitalization was more pronounced in the years prior to the development of a national health care program (1966). Another key finding is a gradual reduction since 1994 in hospital deaths, with this reduction occurring across all sociodemographic variables. This suggests nonhospital care options are needed to support what may be an ongoing shift away from hospitalized death and dying.

Midsagittal facial tissue thicknesses of children and adolescents from the Montreal growth study

Knowledge of changes in soft tissue depths during growth and development is important in applied contexts of forensics and dentistry as well as in growth research. In forensics, applications include facial reproductions, video superimpositions, and child aging/progressions. Garlie and Saunders (1) recently published radiographic data from the Burlington Canadian growth study; here, we present data from a mixed longitudinal sample of French-Canadian children and adolescents. Females (N = 159) range in age from 6 to 18 years: males (N = 129), from 6 to 19 years. Cephalometric measurements include nine soft tissue thicknesses, two hard tissue distances (sella-nasion and nasion-menton), and three measures of nasal projection. Several tissue thicknesses are moderately correlated with one another. The majority of thicknesses show significant sex differences by the time of adolescence; nasion and upper labial thicknesses are significantly different by sex at all ages from 6 to 18 years, as are the two hard tissue distances. However, thickness at nasion, as well as at glabella, changes little over time. Thickness at pogonion is variable and differs most between males and females at age 16; the length of the anterior inferior portion of the nose is significantly different between the ages of 6 and 12. Measurements display small and slow changes during development. The greatest average change per year (c. 2 mm/yr) is for a hard tissue measure, nasion-menton. The nasal and mid-philtrum regions have greater age changes than do other soft tissue variables. Much of the variation remains unexplained by changes with age or differences between sexes.

Delayed spontaneous superior vena cava perforation associated with a SVC wallstent

A patient was referred for superior vena cava (SVC) stenting prior to surgical biopsy of a mediastinal mass. A technically satisfactory insertion was followed 6 months later by cardiac tamponade with two legs of the Wallstent having perforated the wall of the SVC.

The effect of femoral head diameter upon lubrication and wear of metal-on-metal total hip replacements

It has been found that a remarkable reduction in the wear of metal-on-metal hip joints can be achieved by simply increasing the diameter of the joint. A tribological evaluation of metal-on-metal joints of 16, 22.225, 28 and 36 mm diameter was conducted in 25 per cent bovine serum using a hip joint simulator. The joints were subject to dynamic motion and loading cycles simulating walking for both lubrication and wear studies. For each size of joint in the lubrication study, an electrical resistivity technique was used to detect the extent of surface separation through a complete walking cycle. Wear of each size of joint was measured gravimetrically in wear tests of at least 2 x 10(6) cycles duration. Joints of 16 and 22.225 mm diameter showed no surface separation in the lubrication study. This suggested that wear would be proportional to the sliding distance and hence joint size in this boundary lubrication regime. A 28 mm diameter joint showed only limited evidence of surface separation suggesting that these joints were operating in a mixed lubrication regime. A 36 mm diameter joint showed surface separation for considerable parts of each walking cycle and hence evidence of the formation of a protective lubricating film. Wear testing of 16 and 22.225 mm diameter metal-on-metal joints gave mean wear rates of 4.85 and 6.30 mm3/10(6) cycles respectively. The ratio of these wear rates, 0.77, is approximately the same as the joint diameters ratio, 16/22.225 or 0.72, as expected from simple wear theory for dry or boundary lubrication conditions. No bedding-in was observed with these smaller diameter joints. For the 28 mm diameter joint, from 0 to 2 x 10(6) cycles, the mean wear rate was 1.62 mm3/10(6) cycles as the joints bedded-in. Following bedding-in, from 2.0 x 10(6) to 4.7 x 10(6) cycles, the wear rate was 0.54 mm3/10(6) cycles. As reported previously by Goldsmith et al. in 2000 [1], the mean steady state wear rate of the 36 mm diameter joints was lower than those of all the other diameters at 0.07 mm3/10(6) cycles. For a range of joints of various diameters, subjected to identical test conditions, mean wear rates differed by almost two orders of magnitude. This study has demonstrated that the application of sound tribological principles to prosthetic design can reduce the wear of metal-on-metal joints, using currently available materials, to a negligible level.

Optimization of culture conditions to enhance transfection of human CD34+ cells by electroporation

The ability to culture CD34+ stem cells, while maintaining their pluripotency, is essential for manipulations such as gene transfection for therapeutic trials. Human peripheral blood (PB) CD34+ cells (> or = 90% purity) were cultured for up to 4 days in serum-free culture medium supplemented with thrombopoietin (TPO), stem cell factor (SCF), Flt-3 ligand (Flt-3L), with or without PIXY321 (IL-3/GM-CSF fusion protein) and human serum. The CD34 mean fluorescence intensity (MFI) and cell cycle status were evaluated daily using flow cytometry and hypotonic propidium iodide. Prior to culture (day 0), 97.0 +/- 0.9%, 1.9 +/- 0.3% and 1.0 +/- 0.6% of the selected CD34+ cells were in G0-G1, S-phase, or G2-M, respectively. After 2-4 days in culture with TPO/SCF/Flt-3L, there was an increase in the percent of cells in S-phase to 26.4 +/- 0.1% without significant loss of CD34 MFI. The addition of PIXY321 increased.the percentage of CD34+ cells in S-phase to 36.3 +/- 4.0%, but the CD34 MFI and numbers of CFU (colony-forming units) were significantly decreased at day 3 when cultured with PIXY321 or various recombinant cytokine combinations that included IL-3 and IL-6. There is an increase from day 0 to day 4 in the percentages of CD34+ with CD38-, HLA-DR-, and c-kit(low), but not Thy-1+ cells. Electroporation with EGFP reporter gene showed that 1-2 days of pre-stimulation in X-VIVO 10 supplemented with TPO/SCF/Flt-3L was necessary and sufficient for efficient transfection. Flow cytometry analysis demonstrated that 22% of the viable cells are CD34+/EGFP+ 48 h post electroporation. The introduced reporter gene appears to be stable as determined by EGFP+/LTC-IC (long-term colony-initiating cells), at 30-40 positive colonies (16 +/- 7%) per 1 x 10(5) electroporated CD34+ cells.

BTS 72664-- a novel CNS drug with potential anticonvulsant, neuroprotective, and antimigraine properties

BTS 72664, (R)-7-[1-(4-chlorophenoxy)]ethyl]-1,2,4-triazolo(1,5-alpha)pyrimidine, was identified as a drug development candidate from a research program designed to discover novel, broad-spectrum, non-sedative anticonvulsant drugs. BTS 72664 antagonized bicuculline (BIC)- and maximal electroshock (MES)-induced convulsions with ED(50) values of 1.9 and 47.5 mg/kg p.o., respectively. In rodents, it has a wide spectrum of activity preventing seizures induced by picrotoxin, pentylenetetrazol, i.c.v. 4-aminopyridine or NMDA, and audiogenic seizures in DBA-2 mice and GEPR-9 rats. BTS 72664 was also effective in preventing convulsions in amygdala-kindled rats The lack of sedative potential was predicted on the basis of wide separation between ED(50) in anticonvulsant models and TD(50) for motor impairment in mice in rotating rod and inverted horizontal grid tests. BTS 72664 is likely to produce its anticonvulsant effect by enhancing chloride currents through picrotoxin-sensitive chloride channels, and by weak inhibition of Na(+) and NMDA channels. It does not act, however, at the benzodiazepine binding site. In addition to its potential use in the treatment of epilepsy BTS 72664 may be useful in the treatment of stroke. At 50 mg/kg p.o. x 4, given to rats at 12 hourly intervals, starting at 15 min after permanent occlusion of middle cerebral artery (MCA), it reduced cerebral infarct size by 31% (measured at 2 days after insult) and accelerated recovery in a functional behavioral model. BTS 72664 prevented increases in extraneuronal concentrations of glutamate, glycine and serine brain levels induced by a cortical insult to rats (cf. cortical spreading depression). It may, therefore, have also antimigraine activity.