Direct introgression of untapped diversity into elite wheat lines

The effective utilization of natural variation has become essential in addressing the challenges that climate change and population growth pose to global food security. Currently adopted protracted approaches to introgress exotic alleles into elite cultivars need substantial transformation. Here, through a strategic three-way crossing scheme among diverse exotics and the best historical elites (exotic/elite1//elite2), 2,867 pre-breeding lines were developed, genotyped and screened for multiple agronomic traits in four mega-environments. A meta-genome-wide association study, selective sweeps and haplotype-block-based analyses unveiled selection footprints in the genomes of pre-breeding lines as well as exotic-specific associations with agronomic traits. A simulation with a neutrality assumption demonstrated that many pre-breeding lines had significant exotic contributions despite substantial selection bias towards elite genomes. National breeding programmes worldwide have adopted 95 lines for germplasm enhancement, and 7 additional lines are being advanced in varietal release trials. This study presents a great leap forwards in the mobilization of GenBank variation to the breeding pipelines.

[siRNAs with high specificity to the target: a systematic design by CRM algorithm]

'Off-target' silencing effect hinders the development of siRNA-based therapeutic and research applications. Common solution to this problem is an employment of the BLAST that may miss significant alignments or an exhaustive Smith-Waterman algorithm that is very time-consuming. We have developed a Comprehensive Redundancy Minimizer (CRM) approach for mapping all unique sequences ("targets") 9-to-15 nt in size within large sets of sequences (e.g. transcriptomes). CRM outputs a list of potential siRNA candidates for every transcript of the particular species. These candidates could be further analyzed by traditional "set-of-rules" types of siRNA designing tools. For human, 91% of transcripts are covered by candidate siRNAs with kernel targets of N = 15. We tested our approach on the collection of previously described experimentally assessed siRNAs and found that the correlation between efficacy and presence in CRM-approved set is significant (r = 0.215, p-value = 0.0001). An interactive database that contains a precompiled set of all human siRNA candidates with minimized redundancy is available at http://129.174.194.243. Application of the CRM-based filtering minimizes potential "off-target" silencing effects and could improve routine siRNA applications.

A case-control study to investigate an association between adverse pregnancy outcome and periodontal disease

OBJECTIVES

The aim of this case-control study was to ascertain if women who experienced a preterm (or premature) birth had any differences in periodontal disease severity compared with women who delivered at term.

MATERIAL AND METHODS

Subjects were recruited postpartum. Case subjects delivered a baby before 37 weeks of gestation whereas control subjects gave birth at or around term. A questionnaire was administered by a Research Midwife, designed to collect demographic information, pregnancy outcome variables and information on other factors which may influence health in pregnancy. A periodontal examination was then performed at the bedside.

RESULTS

Demographic variables were similar between case and control subjects. There was a higher proportion of case subjects who reported smoking. There were no differences in oral hygiene, bleeding on probing or loss of attachment; however, control subjects had a higher proportion of periodontal pockets probing 5 mm or greater.

CONCLUSIONS

There was no association between the severity of periodontal disease and pregnancy outcome in this population.

A prospective study to investigate the relationship between periodontal disease and adverse pregnancy outcome

OBJECTIVE

This study aimed to investigate a relationship between maternal periodontal disease and preterm birth, low birth weight and late miscarriage.

DESIGN

Prospective study in a single centre.

SETTING

Guy's and St Thomas' Hospital Trust, London, UK between August 1998 and July 2001.

SUBJECTS AND METHODS

Pregnant women were recruited on attending an ultrasound scan at approximately 12 weeks of pregnancy. Subjects completed a questionnaire and underwent periodontal examination.

MAIN OUTCOME MEASURES

Plaque and bleeding scores, pocket probing depth and loss of attachment. Pregnancy outcome data was collected retrospectively, including gestational age and birth weight at delivery.

RESULTS

Data were collected for 3,738 subjects. Regression analysis indicated that there were no significant relationships between the severity of periodontal disease and either preterm birth (PTB) or low birth weight (LBW). In contrast, there did appear to be a correlation between poorer periodontal health and those that experienced a late miscarriage.

CONCLUSIONS

There was no association between either preterm birth or low birth weight and periodontal disease in this population. There is evidence of a correlation between markers of poorer periodontal health and late miscarriage.

An investigation into the association among preterm birth, cytokine gene polymorphisms and periodontal disease

OBJECTIVE

To investigate a putative relationship between preterm delivery and the carriage of polymorphic genes that code for the cytokines interleukin-1beta (IL-1beta) at codon +3953 and tumour necrosis factor-alpha (TNF-alpha) at codon -308 in a group of postpartum women and to elucidate if the concurrent presence of periodontal disease increased the risk of preterm delivery in this group.

DESIGN

Case-control study

SETTING

Postnatal wards at Guy's and St Thomas' Hospital Trust.

POPULATION

Postpartum women from southeast London, UK.

METHODS

Case subjects were defined as those who experienced a birth at less than 37 weeks of gestation. Control subjects gave birth at term. Demographic data were collected and a periodontal examination was performed. Blood samples were collected and analysed by restriction fragment length polymerase techniques for the presence of each of the allelic variants.

MAIN OUTCOME MEASURES

The level of periodontal disease and the carriage of allelic variants of IL-1beta+3953 and TNF-alpha-308 genes.

RESULTS

Forty-eight case subjects and 82 control subjects were assessed. There was no statistically significant difference in the carriage of the IL-1beta+3953 allelic variant between cases and controls (29%versus 18%, P= 0.112). However, 23 (48%) of the case subjects and 24 (29%) of controls were heterozygous or homozygous for the variant TNF-alpha-308 gene (odds ratio [OR] 2.2, 95% confidence interval [CI] 1.0-5.0, P= 0.026). There was no association between the carriage of either the polymorphic IL-1beta+3953 or TNF-alpha-308 variant and the severity of periodontal disease. The combination of periodontal disease and the allelic variant did not increase the risk of preterm delivery.

CONCLUSIONS

In this study, a higher proportion of women who delivered preterm carried the polymorphic TNF-alpha-308 gene. There did not appear to be any interaction between either of the genotypes and periodontal disease with preterm delivery as has been reported for bacterial vaginosis and the TNF-alpha-308 polymorphic gene.

Pattern of adolescent growth among the Brahmin girls--rural-urban variation

A cross-sectional study of adolescent growth was undertaken among the Brahmin girls residing in rural and urban areas of Sagar districts, Madhya Pradesh to evaluate the urban-rural differences. Six anthropometric measurements, such as weight, stature, sitting height, head circumference, upper arm circumference and chest girth are taken into consideration. Though the urban girls show consistently higher values of weight, stature, sitting height and chest girth than the rural girls, but in case of head circumference and upper arm circumference they show consistently lower values. The maximum increment occurs between the ages 13 and 14 years in all the six measurements in both rural and urban girls.

Improvement of symptoms in infant colic following reduction of lactose load with lactase

Transient lactose intolerance has been identified as a possible causative factor in infant colic. A double-blind randomised placebo-controlled crossover study to investigate this has been undertaken in 53 babies with symptoms of colic. Pre-incubation of the feed with lactase resulted in breath hydrogen levels and total crying time which were both at least 45% lower than figures with placebo treatment, in 26% of the full trial group (95% confidence interval 12.9% to 44.4%), and in 38% of compliers (95% confidence interval 18.8% to 59.4%). The remainder did not respond to the same extent. These findings suggest that infant colic may have a multiple aetiology, and that in a significant number of cases the immediate cause is transient lactose intolerance, in which cases pretreatment of feeds with lactase can result in considerable symptomatic benefits.

Extracorporeal enzymatic heparin removal: use in a sheep dialysis model

Extracorporeal medical devices such as the hemodialyzer rely on systemic heparinization to prevent thrombus formation. Heparin, however, can lead to serious hemorrhagic complications. A blood filter containing immobilized heparinase, a heparin specific enzyme, was used to degrade heparin into small fragments which have significantly less anticoagulant activity than the parent compound. The heparinase filter was tested in the extracorporeal circuit during the hemodialysis of adult sheep. At a blood flow of 200 ml/min, the clearance of heparin varied from 50 to 70 ml/min (N = 16) depending on the amount of immobilized heparinase in the filter. Hemolysis was insignificant as measured by the animals' red cell counts, hematocrit, total hemoglobin and a plasma-free hemoglobin value of 89 +/- 33 mg/dl (N = 16) (less than 1% of the total hemoglobin). The white cell counts dropped to 47 +/- 7% (N = 16) of the initial value at 20 minutes and rebounded to 72 +/- 10% (N = 16) after one hour. The platelet counts decreased to 55 +/- 8% (N = 16) of the initial value after one hour. No change in heparin clearance was observed when reactors were used repeatedly in adult sheep over a 10 week period. The red cell counts, white cell counts, platelet counts, total hemoglobin and hematocrit did not change after 10 weeks of exposure to the device. These results suggest that with further study, heparinase may be useful in removing heparin used to anticoagulate blood in extracorporeal circuits.