Understanding the controls on deposited fine sediment in the streams of agricultural catchments

Excessive sediment pressure on aquatic habitats is of global concern. A unique dataset, comprising instantaneous measurements of deposited fine sediment in 230 agricultural streams across England and Wales, was analysed in relation to 20 potential explanatory catchment and channel variables. The most effective explanatory variable for the amount of deposited sediment was found to be stream power, calculated for bankfull flow and used to index the capacity of the stream to transport sediment. Both stream power and velocity category were highly significant (p ≪ 0.001), explaining some 57% variation in total fine sediment mass. Modelled sediment pressure, predominantly from agriculture, was marginally significant (p<0.05) and explained a further 1% variation. The relationship was slightly stronger for erosional zones, providing 62% explanation overall. In the case of the deposited surface drape, stream power was again found to be the most effective explanatory variable (p<0.001) but velocity category, baseflow index and modelled sediment pressure were all significant (p<0.01); each provided an additional 2% explanation to an overall 50%. It is suggested that, in general, the study sites were transport-limited and the majority of stream beds were saturated by fine sediment. For sites below saturation, the upper envelope of measured fine sediment mass increased with modelled sediment pressure. The practical implications of these findings are that (i) targets for fine sediment loads need to take into account the ability of streams to transport/retain fine sediment, and (ii) where agricultural mitigation measures are implemented to reduce delivery of sediment, river management to mobilise/remove fines may also be needed in order to effect an improvement in ecological status in cases where streams are already saturated with fines and unlikely to self-cleanse.

Tongue-tie and frenotomy in infants with breastfeeding difficulties: achieving a balance

AIMS

Currently there is debate on how best to manage young infants with tongue-tie who have breastfeeding problems. One of the challenges is the subjectivity of the outcome variables used to assess efficacy of tongue-tie division. This structured review documents how the argument has evolved. It proposes how best to assess, inform and manage mothers and their babies who present with tongue-tie related breastfeeding problems.

METHODS

Databases were searched for relevant papers including Pubmed, Medline, and the Cochrane Library. Professionals in the field were personally contacted regarding the provision of additional data. Inclusion criteria were: infants less than 3 months old with tongue-tie and/or feeding problems. The exclusion criteria were infants with oral anomalies and neuromuscular disorders.

RESULTS

There is wide variation in prevalence rates reported in different series, from 0.02 to 10.7%. The most comprehensive clinical assessment is the Hazelbaker Assessment Tool for lingual frenulum function. The most recently published systematic review of the effect of tongue-tie release on breastfeeding concludes that there were a limited number of studies with quality evidence. There have been 316 infants enrolled in frenotomy RCTs across five studies. No major complications from surgical division were reported. The complications of frenotomy may be minimised with a check list before embarking on the procedure.

CONCLUSIONS

Good assessment and selection are important because 50% of breastfeeding babies with ankyloglossia will not encounter any problems. We recommend 2 to 3 weeks as reasonable timing for intervention. Frenotomy appears to improve breastfeeding in infants with tongue-tie, but the placebo effect is difficult to quantify. Complications are rare, but it is important that it is carried out by a trained professional.

Invasive markers identified by gene expression profiling in pancreatic cancer

BACKGROUND

Molecular profiling has proven utility as a diagnostic and predictive tool in clinical oncology. However, a clinically relevant gene expression profile in pancreatic cancer remains elusive.

METHODS

Primary and metastatic pancreatic cancer cell lines (BxPC-3 and AsPC-1), were stimulated with phorbol-12-myristate 13-acetate (PMA), a known inducer of cell invasion. Affymetrix gene expression microarray analysis was performed, comparing gene expression to unstimulated controls. Differential expression was identified using ArrayAssist, and confirmed using quantitative real-time PCR. Bioinformatic analysis was performed using Pathway Studio and GOstat. The derived gene expression was further validated in fresh frozen pancreatic tumour samples. The ability of the derived 3 gene expression markersto differentiate between pancreatic adenocarcinoma (PDAC) and other neoplasms, and its association with clinicopathological variables was examined.

RESULTS

PMA-induced significant changes in cell line gene expression, from which distinctive 3 potential invasive markers were derived. Expression of these genes, uPA, MMP-1 and IL1-R1 was confirmed in human pancreatic tumours, and was found to differentiate PDAC from other pancreatic neoplasms. The expression of IL1-R1 in PDAC is a novel finding. We found that the expression of MMP-1 was associated with high-grade PDAC (p = 0.035, Wilcoxon rank sum).

CONCLUSION

We have identified three potential invasive markers, uPA, MMP-1 and IL1-R1, whose gene expression may differentiate PDAC from other pancreatic neoplasms, and potentially reflect a more invasive phenotype.

Abundance and diversity of aquatic macroinvertebrate communities in lakes exposed to Chernobyl-derived ionising radiation

Littoral (lake shore) macroinvertebrate communities were studied in eight natural lakes affected by fallout from the Chernobyl accident. The lakes spanned a range in (137)Cs contamination from 100 to 15500 kBq m(-2) and estimated external dose rates ranged from 0.13 to 30.7 μGy h(-1). General linear models were used to assess whether abundance of individuals, taxon richness, Berger-Parker dominance and Shannon-Wiener diversity varied across the lakes. Step-wise multiple regressions were used to relate variation in total abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity, taxon richness within major groups of macroinvertebrates and abundance of the more common individual taxa to the measured environmental characteristics (conductivity, pH, total hardness and phosphate; lake area, lake maximum depth and total external dose) of the lakes. No evidence was found in this study that the ecological status of lake communities has been influenced by radioactive contamination from the Chernobyl accident. Indeed, the most contaminated lake, Glubokoye, contained the highest richness of aquatic invertebrates. Taxon richness in the eight study lakes varied from 22 (Svyatskoe #7) to 42 (Glubokoye) which spans a range typical for uncontaminated lakes in the region. Since (90)Sr is readily-absorbed by Mollusca, estimated dose rates to this group exceeded those for other invertebrate groups in two lakes (Perstok and Glubokoye). However this study found no association between mollusc diversity or abundance of individual snail species and variation between lakes in the external radiation dose. Indeed Glubokoye, the lake most contaminated by (90)Sr, had the highest richness of freshwater snails per sample (an average of 8.9 taxa per sample).

Congenital diaphragmatic hernia: neonatal outcomes following referral to a paediatric surgical centre

Congenital diaphragmatic hernia (CDH) is a rare malformation observed in approximately 1 in 3000 live births. Estimates of postnatal survival range from 50 to 70% despite advances in neonatal care. Antenatal diagnosis is associated with termination of pregnancy in 25-50% pregnancy internationally which may not be reflective of the Irish population. We aimed to evaluate the mortality of infants with CDH who survived to admission in a tertiary referral paediatric hospital between 1996 and 2007. The Hospital In-Patient Enquiry system was used to determine the number of neonatal referrals for CDH to OLHSC between 1996 and 2007. Mortality, sex distribution, length of patient stay and the number of cases per year were examined. 141 neonates with CDH were over 12 years with approximately 12 referrals per annum of which 82 (58%) were male and 59 (42%) female. The average length of stay in the hospital was 33 (range 0-364) days. Overall 71% of the patients survived to discharge. In the first epoch (1996-2001) survival was 63% compared with 78% in the later epoch (2002-7). The overall survival for neonates with CDH presenting to OLCHC during the 12 year-period was 71% although this improved to 78% in recent epoch. Further study of associated congenital anomalies, number of terminations of pregnancy, complexity of the diaphragmatic defect and degree of pulmonary hypertension are required to compare this population with other international centres.

Pheochromocytoma, sickle cell disease and pregnancy: a case report

Pheochromocytomas are rare catecholamine-secreting tumors with a 2-4% maternal morbidity rate and a fetal loss rate of 11%. Sickle cell disease is also associated with increased maternal and fetal mortality. We report the first case of a primigravid woman with both conditions and a successful pregnancy outcome.

First Report of Tobacco ringspot virus in Blackberry (Rubus sp.) in Alabama

In 2006, primocane stunted growth and crumbly berry development were observed on 4-year-old Kiowa and Apache blackberry cultivars grown at the Chilton Research and Extension Center, Clanton, AL. Samples from affected plants were tested for virus infection by ELISA kits (Agdia, Inc., Elkhart, IN) specific to each of 14 different viruses. Most samples tested positive for Tobacco ringspot virus (TRSV). TRSV was detected in blackberry samples from North Carolina and South Carolina (2). Bray et al. (1) studied the incidence of viruses in blackberry nursery stock in the United States and reported that 9% of the tested samples contained TRSV. Thus, a survey was conducted for TRSV incidence among commercial blackberry stands in eight counties in Alabama during July 2007. Blackberry plants were observed to express virus-like symptoms including chlorotic spots on leaves, leaf veinal chlorosis, stunting, and combinations thereof. Fruit-bearing plants sometimes had crumbly fruit symptoms characteristic of virus infection. Leaf samples that were collected from symptomatic and nonsymptomatic plants representing 14 cultivars were tested by TRSV ELISA (Agdia, Inc.). Of 180 blackberry samples, 68 tested positive for TRSV. Positive ELISA reactions for TRSV were on average 28 times greater than the reactions of known negative control samples considered negative for TRSV. Blackberry plants shown to be infected with TRSV during the 2007 survey were tested in July 2008 in an effort to confirm the presence of TRSV. Fifty-four percent of the samples tested positive by ELISA with the average positive ELISA value being 21 times higher than the average negative ELISA value for known negative control samples. To further confirm the occurrence of TRSV in Alabama-grown blackberry plants, leaf samples were tested by reverse transcription (RT)-PCR to amplify a 329-bp fragment of the viral coat protein gene (TRSV RNA 2 sequence accession no. NC_005096; primers TRSCP-F (5'-TCTGGCACTATAAGCGGAAG-3') and TRSCP-R (5'-GAAAACATGGGAGGATGCAC-3'). A single band of the anticipated size was amplified (analyzed by agarose gel electorphoresis and visualized by ethidium bromide staining) from RNA samples extracted with a RNeasy Mini kit (Qiagen, Valencia, CA) from blackberry samples that tested positive for TRSV by ELISA and a known positive control. No amplified product resulted from a blackberry sample that tested negative for TRSV by ELISA. These results illustrate and confirm the presence of TRSV in blackberry leaf tissues grown in Alabama. To our knowledge, this is the first report of TRSV infection of blackberry plants in Alabama. References: (1) M. M. Bray et al. HortScience 40:874, 2005. (2) T. L. Guzmán-Baeny. Incidence, distribution, and symptom description of viruses in cultivated blackberry (Rubus subgenus Eubatus) in the southeastern United States. M.S. thesis, North Carolina State University, Raleigh, 2003.

Genetic variation and covariation for resistance and tolerance to Cucumber mosaic virus in Mimulus guttatus (Phrymaceae): a test for costs and constraints

Genetic variation for resistance and tolerance to pathogens may be maintained by costs represented as genetic tradeoffs between these traits and fitness. The evolution of resistance and tolerance also may be constrained by negative genetic correlations between these defense systems. Using a complete diallel, we measured genetic variation and covariation for and among performance, resistance, and tolerance traits in Mimulus guttatus challenged with a generalist pathogen, Cucumber mosaic virus (CMV). Viral coat protein was detected by enzyme-linked immunosorbent assay (ELISA) in all inoculated plants, indicating that all plants were susceptible to infection, although the ELISA absorbance varied quantitatively across plants. Plants inoculated with CMV had significantly reduced aboveground biomass and flower production relative to controls, although date of first flower was unaffected by infection. All three of these performance traits showed moderate to high narrow-sense heritability (h2 = 0.32-0.62) in both inoculated and control plants. We found phenotypic variation for both tolerance of and resistance to our strain of CMV, but both displayed very low narrow-sense heritability (h2 < 0.03). We found no evidence of a trade-off between resistance and tolerance. We also found no evidence for a cost of resistance or tolerance. In fact, a significant genetic correlation suggested that plants that were large when healthy had the greatest tolerance when infected. Significant, positive genetic correlations found between performance of uninfected and infected plants suggested that selection would likely favor the same M. guttatus genotypes whether CMV is present or not.

Elective Caesarean section is associated with a reduction in developmental dysplasia of the hip in term breech infants

We wished to establish whether delivery by Caesarean section influenced the incidence of developmental dysplasia of the hip in term breech infants compared with those delivered vaginally. We used maternal charts, singleton term breech presentation, mode of delivery and incidence of developmental dysplasia of the hip for births between January 1997 and October 2002.

During the study period 46 089 infants were born. We analysed a total of 941 breech infants of whom 756 were delivered by Caesarean section (515 pre-labour, 241 intrapartum) and 185 vaginally. The incidence of developmental dysplasia of the hip according to the mode of delivery was 19 of 515 (3.69%) following pre-labour Caesarean section, 16 of 241 (6.64%) for intrapartum Caesarean section and 15 of 185 (8.11%) after vaginal delivery. There was a lower incidence of developmental dysplasia of the hip among those infants delivered by elective Caesarean section compared with those delivered vaginally (p < 0.02). These results demonstrate a significantly lower incidence of developmental dysplasia of the hip in term singleton breech births delivered by elective, pre-labour Caesarean section and suggest that labour and delivery influence hip stability in predisposed infants.

Auditing hip ultrasound screening of infants at increased risk of developmental dysplasia of the hip

BACKGROUND

Clinical examination, while useful, has been shown to be insufficient as the sole screening method in infants. Ultrasound examination at 8 weeks in high risk infants is an integral part of the screening process in some units.

AIMS

To show the efficiency of hip sonography in detection of developmental dysplasia of the hips in those without clinically dislocated hips.

METHODS

All infants born at the National Maternity Hospital between January 1994 and December 2001 were included. All those with clinically dislocated hips were treated by a Pavlik harness and referred for follow up to a paediatric orthopaedic surgeon. An 8 week hip ultrasound scan was performed for those infants with stable hips on examination but who met the following criteria: (1) a first degree relative with congenital dislocation of hips; (2) breech presentation at birth; and (3) a persistent "click" at birth in an otherwise stable hip.

RESULTS

During the period of study a total of 52 893 infants were born in the National Maternity Hospital. Based on the criteria above, 5485 hip ultrasound scans were performed. Of those scanned, 18 (0.33%) were found to have dislocated hips and 153 (2.78%) to have dysplasic hips. The 18 infants with dislocation were treated with Pavlik harness; the remaining 153 were followed up by serial ultrasound examinations but did not require active intervention.

CONCLUSIONS

Among the population of infants at increased risk of developmental dysplasia of the hip, the hip screening programme identified 18 cases among 5485 infants; a rate of 3.2 per 1000. Hip sonography is therefore worthwhile.

First Report of Bean pod mottle virus in Soybean in Alabama

During October 2003, soybean (Glycine max (L.) Merr.) plants showing symptoms of delayed maturity of stems, or green stem, were observed in a soybean cultivar trial on Dee River Ranch in Pickens County, Alabama. Symptoms were characteristic of those caused by Bean pod mottle virus (BPMV). BPMV infections have been identified in other southern states, including Arkansas, Louisiana, and neighboring Mississippi, but had not yet been identified in Alabama (1,2,3). In this study, a cultivar trial was established as a nonreplicated strip test to evaluate the performance of nongenetically modified soybean cultivars in high-pH soils. The trial consisted of 12 maturity group V cultivars planted side by side in 24-row plots approximately 1 km long. The cultivars consisted of Anand, Asgrow 5547, Asgrow 5944, Delta King 5995, Deltapine 4748, Deltapine 5110, Deltapine 5989, Essex, Hutcheson, Pioneer 9594, Pioneer 9597, and USG5601T. During the season, a known vector of BPMV, the bean leaf beetle (Cerotoma trifurcate Forster), was identified in the plots (4). On 10 October, the majority of plants in the trial had senesced; however, it was observed that plants of 6 of the 12 cultivars were showing symptoms of green stem typical of BPMV infection. A visual assessment was taken to determine incidence of green stem for Asgrow 5547, Delta King 5995, Deltapine 5110, Deltapine 5989, Pioneer 9594, and USG5601T. Incidence between 1 and 5% was observed for Delta King 5995, Deltapine 5989, and Pioneer 9594. Incidence of less than 1% was observed for Asgrow 5547, Deltapine 5110, and USG5601T. Twenty soybean plants showing symptoms of green stem and retaining green leaves were sampled from each of the six cultivars by collecting one trifoliate leaf near the top of the plant. All samples were tested for BPMV using double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) according to the manufacturer's instructions (Agdia, Inc., Elkart, IN). BPMV was detected in 30% of Deltapine 5989, 10% of Delta King 5995, and 45% of Pioneer 9594 plants. BPMV was not detected in Asgrow 5547, Deltapine 5110, and USG5601T. Ten of the samples shown to be infected with BPMV using DAS-ELISA were mechanically transferred to soybean seedlings in the greenhouse. These plants developed systemic mottle symptoms typical of those caused by BPMV and tested positive for the virus BPMV using DAS-ELISA. To our knowledge, this is the first report of BPMV in Alabama. References: (1) N. S. Horn et al. LA. Agric. 13:12, 1970. (2) H. N. Pitre et al. Plant Dis. Rep. 63:419, 1979. (3) J. P. Ross. Plant Dis. Rep. 47:1049, 1963. (4) H. J. Walters. (Abstr.) Phytopathology 48:346, 1958.

Vein of Galen aneurysm malformation (VGAM): closing the management loop

We report a case where an antenatal scan showed a cerebral vessel dilatation consistent with a vein of Galen malformation (VGAM). After delivery the diagnosis was confirmed on MRI scan. The infant's condition was stable in relation to the two important clinical indicators, mainly not in congestive cardiac failure and no hydrocephalus. The vein of Galen assessment score as used in Hopital Bicetre was 20/21. The scoring system is based on a multiorgan assessment including the five parameters cardiac, cerebral, respiratory, hepatic and renal (Table 1). A score of < 8 indicates no treatment, 8-12 means immediate intervention while a score > 12 delays intervention to circa six months of age. At four months the head circumference accelerated with hydroceaphalus on scans and the infant became clinically symptomatic. Urgent embolisation was performed. The procedure uses N-butylcyanoacrylate (NBCA) glue as the embolisation agent, which in this case was inserted through the left posteriomedial choroidal artery. Complete obliteration was achieved. The infant subsequently required insertion of a ventriculoperitoneal shunt for the hydrocephalus component. The infant has had no recurrence. He remains well on objective examination he has mild developmental delay. In summary this case highlights the value of antenatal diagnosis,the VGAM assessment score to determine the optimal time of intervention and the effectiveness of embolisation.

Helicobacter pylori induces cyclooxygenase-1 and cyclooxygenase-2 expression in vascular endothelial cells

BACKGROUND

Helicobacter pylori induces cyclooxygenase activity in the stomach, although the COX isoform and cellular source are unclear. A potential source is the vascular endothelial cell, which plays a role in regulating mucosal blood flow and inflammatory cell infiltration.

METHODS

We examined the effect of four strains (toxigenic and non-toxigenic) of H. pylori on COX isoform expression in vascular endothelial cells. Prostaglandin synthesis was measured by enzyme immunoassay and COX isozyme expression determined by Western blot and RT-PCR. Gene induction was examined using 5' deletion constructs of the COX-1 and COX-2 promoters coupled with luciferase.

RESULTS

All H. pylori strains induced prostaglandin generation and expression of both COX-1 and COX-2 in HUVEC, although this was most pronounced with the highly toxigenic strain H. pylori 60190. Treatment of the cells with selective COX inhibitors demonstrated that COX-1 was predominantly responsible for the enhanced generation of prostacyclin induced by H. pylori 60190. Similar results were seen with H. pylori broth culture filtrates, suggesting that a secreted product was responsible. Induction of COX-2 reflected both enhanced gene expression and stabilization of the mRNA.

CONCLUSIONS

H. pylori increased both COX-1 and COX-2 activity in vascular endothelial cells. This increased generation of endothelial cell prostacyclin may play a role in modulating mucosal blood flow, platelet function and inflammatory cell infiltration in response to H. pylori infection. The regulation of COX-1 at the transcriptional level by H. pylori described in this study is a novel finding and calls into question the traditional description of COX-1 as a purely constitutive, housekeeping gene.

Tobacco mosaic virus in Jalapeno Pepper in New York

Jalapeno pepper plants (Capsicum annuum cv. Jaladuro) grown in Erie County, New York expressed chlorotic oak-leaf patterns along the primary vein of fully expanded leaves. Fruit had patterns of irregular ripening with a bumpy surface. Symptom expression was most obvious in August 2002, when leaf and fruit abscission occurred. Symptomatic fruit samples were tested by western blot analysis for the presence of Cucumber mosaic virus (CMV), Potato virus Y (PVY), Pepper mottle virus (PepMoV), Tobacco etch virus (TEV), and Tobacco mosaic virus (TMV). A positive reaction for TMV, but none of the other viruses, was observed. Symptomatic leaf samples were tested by Agdia, Inc. (Elkhart, IN) for Alfalfa mosaic virus, CMV, Impatiens necrotic spot virus, Pepper mild mottle virus, PepMoV, PVY, TEV, TMV, Tobacco ringspot virus, Tomato ringspot virus, and TSWV and for potyviruses using a group-specific test. The Agdia test confirmed that the pepper plants were infected with TMV. The pepper field where the original samples were collected was surveyed for TMV-infected plants. Fifty symptomatic plants expressing foliar and fruit symptoms similar to those originally tested, and 50 asymptomatic plants were sampled by collection of three leaves per plant and tested using enzyme-linked immunosorbent assay for the presence of TMV. All symptomatic plants and 18% of asymptomatic plants tested positive for TMV. To our knowledge, this is the first occurrence of TMV causing losses in commercially grown pepper in New York.

The complete nucleotide sequence of Pepper mottle virus-Florida RNA

The Pepper mottle virus-Florida (PepMoV-FL) RNA genome was cloned and sequenced, and shown to consist of 9,717 nucleotides (nt) excluding the poly (A) tail. A single open reading frame was identified beginning at nucleotide position 169 encoding a polyprotein of 3068 amino acids. Phylogenetic sequence analysis revealed that of 44 full-length viral RNA genomes analyzed within the family Potyviridae, PepMoV-FL was most closely related to PepMoV-California (PepMoV-CA), Potato virus Y-H (PVY-H), PVY-N, PVY(o) and Potato virus V-DV42 (PVV-DV42). Using the PepMoV-FL sequence as a basis for comparison, the overall nucleotide sequence identity was highest between PepMoV-FL and PepMoV-CA at 93%, while the relationship was more distant with PVV-DV42 at 64% and for the PVY strains at 61%. A unique direct repeat sequence of 76 nucleotides was identified in the PepMoV-FL 3'-untranslated region (UTR), and this repeat sequence was confirmed not to occur in the PepMoV-CA sequence. Since the Florida isolate was among the first of the PepMoV isolates described, extensive biological and serological data on this isolate are available, and it has now been cloned and sequenced, we recommend that PepMoV-FL be recognized as the PepMoV type strain.

Stimulation of adhesion molecule expression by Helicobacter pylori and increased neutrophil adhesion to human umbilical vein endothelial cells

Helicobacter pylori upregulates endothelial adhesion molecules but the pattern is unclear. Human umbilical vein endothelial cells (HUVEC) were exposed to control medium or H. pylori 60190. Binding of monoclonal antibodies against P-selectin, E-selectin, vascular adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) was determined using enzyme-linked immunosorbent assay. Binding of polymorphonuclear leukocytes to HUVEC was determined on cells exposed as above. After 6 h exposure to H. pylori, there were 30%, 124%, 167% and 100% increases in P-selectin, E-selectin, VCAM-1 and ICAM-1 levels and a 400% increase in polymorphonuclear leukocyte adhesion in HUVEC exposed to H. pylori. Effects of incubation for other intervals between 0 and 18 h are also described. H. pylori exerts some of its effects on gastric mucosa via gastric vasculature. This study gives insight into the pattern of H. pylori-associated endothelial adhesion molecule upregulation.

The relationship between Pepper mottle virus source leaf and spread of infection through the stem of Capsicum sp

Pepper mottle virus (PepMoV) systemically infects Capsicum sp. in a typical source-to-sink manner with movement through the stem occurring in a predictable pattern. This study was carried out to determine the relationship between the inoculated leaf as a source of inoculum and the spread of PepMoV infection through the stem. C. annuum 'Early Calwonder' plants were mechanically inoculated onto the first leaf with PepMoV and sets of 30 plants had their inoculated leaves removed each day from 1 through 7 days post-inoculation (dpi) with the inoculated leaves tested for infection by ELISA at the time of excision. Beginning at 2 dpi, PepMoV infection in the stem of plants with the inoculated leaf excised and plants of a nonexcision control treatment was determined using immuno-tissue blot analysis. PepMoV was detected in inoculated leaves beginning at 3 dpi with the percentage of infected leaves increasing each day through 7 dpi. PepMoV was first detected in the stem of inoculated plants of the 3 dpi excision treatment. The accumulation and extent of spread of infection in the stem was similar for plants that had their inoculated leaf removed at a time preceding detection by ELISA to plants in the nonexcision control treatment. These findings suggest that once virus is allowed to enter the stem from the inoculated leaf, subsequent spread of infection through the stem is a process independent from the source leaf.

Nickel increases susceptibility of a nickel hyperaccumulator to Turnip mosaic virus

Hyperaccumulated Ni can defend plant tissues against herbivores and pathogens. The effectiveness of this defense, however, has not been tested with a viral pathogen. Turnip mosaic virus (TuMV) accumulation was studied in two serpentine species of Streptanthus with different Ni uptake abilities. Plants of a Ni hyperaccumulator, milk-wort jewelflower (S. polygaloides Gray), and a non-hyperaccumulator, plumed jewelflower (S. insignis Jepson), were grown on Ni-amended and unamended soils. Plants were inoculated with TuMV at three different phenological stages: basal rosette, bolting, and flowering. Susceptibility of experimental plants to TuMV was determined either by the magnitude of TuMV accumulation (measured by indirect enzyme-linked immunosorbent assay [ELISA]) or by plant survival. Streptanthus polygaloides plants grown on high-Ni soil were more susceptible to TuMV than low-Ni S. polygaloides at all three phenological stages. All rosette and pre-bolt S. insignis plants were infected by TuMV, but survival and TuMV accumulation were not significantly affected by soil Ni. At flowering, only high-Ni S. polygaloides plants became infected. For S. polygaloides, elevated tissue Ni concentrations enhanced TuMV infection instead of defending plants from the virus. To reduce risks to nearby agricultural crops, future phytoremed. iation and phytomining operations using this species should incorporate management plans to prevent the creation of artificial reservoirs of TuMV inoculum.

Altering the NICU and measuring infants' responses

The aim of the study was to measure the impact of a designated Quiet period on the NICU environment and its influence on the infants' physiological and movement responses. The study group comprised 10 preterm infants on assisted ventilation (mean gestational age 28.7 wk (range 24-32 wk), mean birthweight 1,322 g (range 600-2,060 g), mean age 5.2 d). The environment in which the infants were nursed was altered in terms of reduced light, noise, staff activity and infant handling. The infants' heart rate, blood pressure, oxygen saturation and movement responses were recorded during this Quiet period and compared with a period of Normal activity. When the Quiet period was compared with the Normal period (median values), the NICU environment had significantly altered in terms of Light: Quiet period 3.0 Lux, Normal period 254.5 Lux (p < 0.01); Noise: Quiet period 54.0 dB, Normal period 58.0 dB (p < 0.01); Alarm events: Quiet period 491.5 sec, Normal period 1,180.5 sec (p < 0.01); Staff conversation: Quiet period 16.0 occasions per hour, Normal period 60.0 occasions per hour (p < 0.01); Staff activity: Quiet period 25.5 occasions per hour, Normal period 59.0 occasions per hour (p <0.01); Infant handling: Quiet period 0.0 events per hour, Normal period 4.5 events per hour (p < 0.01). Infants' diastolic blood pressure and mean arterial pressure: median reduction of 2 mmHg for both during the Quiet period (p < 0.05). Infants' movements: Quiet period 14.5 movements per hour, Normal period 84.0 movements per hour (p < 0.05).

DISCUSSION

This study demonstrates that Quiet periods are feasible for infants undergoing neonatal intensive care. The NICU environment was altered significantly for light, noise, infant handling and staff activity for a specified time period. These changes were associated with a reduced median diastolic blood pressure and mean arterial pressure and a decrease in infant movements.

Importance of exercise capacity in the interpretation of a myocardial ischemic response to exercise testing. Multicenter Study of Myocardial Ischemia Group (MSMI)

Patients who were stable 1 to 6 months after a cardiac event underwent routine exercise testing with thallium scintigraphy. The prognosis of patients with good exercise capacity (Bruce stage 3) was similar whether or not ischemia was demonstrated and similar to patients with reduced exercise capacity and no ischemia, whereas the presence of both ischemia and a reduced exercise tolerance identified patients with a significantly poorer prognosis.

Senescent human neutrophil binding to thrombospondin (TSP): evidence for a TSP-independent pathway of phagocytosis by macrophages

This study investigated the interaction of apoptotic polymorphonuclear neutrophils (PMN) with thrombospondin (TSP), an important event mediating the clearance of apoptotic neutrophils by macrophages. We developed an in vitro assay to examine this interaction. Based on this assay, we found that apoptotic but not fresh PMN bound specifically to surface-immobilized TSP (33 +/- 0.03 x 10(3) cells/well) compared to fibrinogen, fibronectin or laminin (8.0 +/- 0.3 x 10(3) cells/well). Moreover, the binding was specific for surface bound but not soluble TSP and appeared to be divalent cation dependent, was not significantly inhibited by heparin and was sensitive to cycloheximide (CHX) treatment of senescent PMN (>90%) inhibition at 10 microM CHX). In contrast to the binding studies, phagocytosis of senescent PMN by macrophages was not affected by EDTA or cycloheximide. Phosphatidyl-L-serine liposomes, phospho-L-serine, glucosamine, galactosamine, and the acetylated sugars had no effect on phagocytosis. We conclude that: (i) there was specific binding of senescent human PMN to immobilized TSP, which is divalent cation dependent and requires new protein synthesis in the PMN during senescence; (ii) in addition to the recently defined TSP-dependent pathway, there is a TSP-independent pathway mediating phagocytosis of senescent PMN by macrophages. The identity of this pathway remains to be defined.

Comparison of liveborn and stillborn low birthweight babies and analysis of aetiological factors

A retrospective study was performed at a tertiary maternity hospital, to define the incidence of low birthweight (LBW) and its associated risk factors in term liveborn infants and in term stillbirths, to ascertain the antenatal detection rate in each and to assess the role of ultrasound in antenatal detection. One hundred and ninety-four term liveborn LBW infants and twenty stillborn LBW infants were studied. Fifty-six percent of the liveborn infants were detected antenatally compared to 5% of the stillborn LBW infants. Previous LBW, the extremes of maternal age, cigarette smoking and pre-eclampsia were the main risk factors for the development of LBW, not all of which were present to the same extent in each group. Ultrasound scanning antenatally increases the detection rate. Knowledge of abnormal growth antenatally significantly increases obstetric intervention. Detection of LBW antenatally remains difficult. The main risk factors for LBW were similar in both groups.