Genetic improvement of Citrus for disease resistance

Progress in the genetic improvement of Citrus species was reviewed. Tools used for the genetic improvement of Citrus were categorised as conventional (introduction, selection and hybridisation) and non-conventional methods (mutation, somatic cell hybridisation and genetic engineering) of improvement. Genes linked with the disease resistance were characterised and tagged through molecular marker techniques such as Sequenced Characterised Amplified Region and Cleaved Amplified Polymorphic Sequences. Disease resistance genes showed both monogenic and polygenic inheritance. Conventional methods for disease resistance improvement of Citrus were bottleneck due to inadequate and lengthy breeding procedures. However, non-conventional methods, such as mutation breeding and protoplast fusion, have been routinely utilised for the production of disease resistant germplasm while novel genes from variable sources were used to transform Citrus species to induce resistance against diseases. These non-conventional techniques have been shown to overcome the disadvantages of conventional breeding procedures and could be regarded as rapid methods of genetic improvement as well as helpful to overcome the interspecies barrier.     

Analysis of the spatio-temporal distribution of Eurygaster integriceps (Hemiptera: Scutelleridae) by using spatial analysis by distance indices and geostatistics

Eurygaster integriceps Puton (Hemiptera: Scutelleridae) is the most serious insect pest of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) in Iran. In this study, spatio-temporal distribution of this pest was determined in wheat by using spatial analysis by distance indices (SADIE) and geostatistics. Global positioning and geographic information systems were used for spatial sampling and mapping the distribution of this insect. The study was conducted for three growing seasons in Gharamalek, an agricultural region to the west of Tabriz, Iran. Weekly sampling began when E. integriceps adults migrated to wheat fields from overwintering sites and ended when the new generation adults appeared at the end of season. The adults were sampled using 1- by 1-m quadrat and distance-walk methods. A sweep net was used for sampling the nymphs, and five 180° sweeps were considered as the sampling unit. The results of spatial analyses by using geostatistics and SADIE indicated that E. integriceps adults were clumped after migration to fields and had significant spatial dependency. The second- and third-instar nymphs showed aggregated spatial structure in the middle of growing season. At the end of the season, population distribution changed toward random or regular patterns; and fourth and fifth instars had weaker spatial structure compared with younger nymphs. In Iran, management measures for E. integriceps in wheat fields are mainly applied against overwintering adults, as well as second and third instars. Because of the aggregated distribution of these life stages, site-specific spraying of chemicals is feasible in managing E. integriceps.     

Comparing aflatoxin contamination in chilies from Punjab,Pakistan produced in summer and winter

A comparison was made of total aflatoxins (AFs) in 43 samples of chilies collected during winter and 42 in summer to determine the effect of season on contamination. The samples were analyzed by HPLC with fluorescence detection. The limits of detection and quantification for AFB₁ and AFG₁ were 0.05 μg/kg and 0.50 μg/kg, whilst for AFG₂ and AFB₂ they were 0.10 μg/kg and 0.60 μg/kg. In the winter samples, AFs were detected in 18 (72%) whole and 14 (60%) ground chilies, with concentration ranges 0.00-52.30 μg/kg and 0.00-74.60 μg/kg respectively. In the summer samples, 17 (64%) whole and 12 (76%) ground chilies were contaminated with AFs at concentrations 0.00-61.50 μg/kg and 0.00-95.90 μg/kg respectively. The percentage of samples greater than the European Union statutory limit for AFB₁ and total AF for whole chilies were 48 and 36%, compared with ground chili values of 50 and 45%, respectively, in the winter season. In the summer season, the samples greater than the European Union limit for AFB₁ and total AF in whole chilies were 52 and 38%, compared with values of 54 and 49% in ground chilies respectively. AF contamination was found to be higher in summer chili samples and hence winter chilies may provide a better quality product with respect to AF contamination. The ability to undertake this analysis in Pakistan will enhance greatly the ability to improve chili production in that country, as described herein.     

Mutations of GIPC3 cause nonsyndromic hearing loss DFNB72 but not DFNB81 that also maps to chromosome 19p

A missense mutation of Gipc3 was previously reported to cause age-related hearing loss in mice. Point mutations of human GIPC3 were found in two small families, but association with hearing loss was not statistically significant. Here, we describe one frameshift and six missense mutations in GIPC3 cosegregating with DFNB72 hearing loss in six large families that support statistically significant evidence for genetic linkage. However, GIPC3 is not the only nonsyndromic hearing impairment gene in this region; no GIPC3 mutations were found in a family cosegregating hearing loss with markers of chromosome 19p. Haplotype analysis excluded GIPC3 from the obligate linkage interval in this family and defined a novel locus spanning 4.08?Mb and 104 genes. This closely linked but distinct nonsyndromic hearing loss locus was designated DFNB81.     

Phenytoin versus Leviteracetam for Seizure Prophylaxis after brain injury – a meta analysis

Background

Current standard therapy for seizure prophylaxis in Neuro-surgical patients involves the use of Phenytoin (PHY). However, a new drug Levetiracetam (LEV) is emerging as an alternate treatment choice. We aimed to conduct a meta-analysis to compare these two drugs in patients with brain injury.

Methods

An electronic search was performed in using Pubmed, Embase, and CENTRAL. We included studies that compared the use of LEV vs. PHY for seizure prophylaxis for brain injured patients (Traumatic brain injury, intracranial hemorrhage, intracranial neoplasms, and craniotomy). Data of all eligible studies was extracted on to a standardized abstraction sheet. Data about baseline population characteristics, type of intervention, study design and outcome was extracted. Our primary outcome was seizures.

Results

The literature search identified 2489 unduplicated papers. Of these 2456 papers were excluded by reading the abstracts and titles. Another 25 papers were excluded after reading their complete text. We selected 8 papers which comprised of 2 RCTs and 6 observational studies. The pooled estimate’s Odds Ratio 1.12 (95% CI?=?0.34, 3.64) demonstrated no superiority of either drug at preventing the occurrence of early seizures. In a subset analysis of studies in which follow up for seizures lasted either 3 or 7?days, the effect estimate remained insignificant with an odds ratio of 0.96 (95% CI?=?0.34, 2.76). Similarly, 2 trials reporting seizure incidence at 6?months also had insignificant pooled results while comparing drug efficacy. The pooled odds ratio was 0.96 (95% CI?=?0.24, 3.79).

Conclusions

Levetiracetam and Phenytoin demonstrate equal efficacy in seizure prevention after brain injury. However, very few randomized controlled trials (RCTs) on the subject were found. Further evidence through a high quality RCT is highly recommended.