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1.
World Dev ; 135: 105064, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32834377

ABSTRACT

Emerging evidence supports the intuitive link between chronic health conditions associated with air pollution and the vulnerability of individuals and communities to COVID-19. Poor air quality already imposes a highly significant public health burden in Northwest India, with pollution levels spiking to hazardous levels in November and early December when rice crop residues are burned. The urgency of curtailing the COVID-19 pandemic and mitigating a potential resurgence later in the year provides even more justification for accelerating efforts to dramatically reduce open agricultural burning in India.

2.
J Environ Manage ; 244: 276-284, 2019 Aug 15.
Article in English | MEDLINE | ID: mdl-31128332

ABSTRACT

Taste and odour (T&O) compounds (most commonly 2-MIB and Geosmin) in drinking water are becoming an increasingly global problem for water management. Here, the trigger(s) for 2-MIB and Geosmin production were investigated in Plas Uchaf reservoir (North Wales, UK) with detailed water sample analysis between 2015 and 2016. Historical abstraction data from this reservoir and 4 reservoirs in Somerset (England, UK) were compared statistically using Self-Organising Map (SOM) analysis. In-reservoir measurements (2015-2016) revealed an 85% reduction in ammonium from the primary external loading source led to lower 2-MIB and Geosmin concentrations, with peak concentrations of 2-MIB declining from 60 to 21Ć¢Ā€ĀÆĆ¢Ā€ĀÆngĆ¢Ā€ĀÆl-1 and Geosmin declining from 140 to 18Ć¢Ā€ĀÆĆ¢Ā€ĀÆngĆ¢Ā€ĀÆl-1. No other measured water chemistry parameter showed a significant difference between years. The SOM results support the in-reservoir findings, revealing 2-MIB and Geosmin to be associated with high ammonium relative to nitrate for all 5 reservoirs. We conclude that ammonium is key for stimulating cyanobacterial productivity and production of T&O compounds. Whilst it is well understood that adequate availability of phosphorus is required for rapid growth in cyanobacteria, and hence should still be considered in management decisions, we suggest that monitoring sources and concentrations of ammonium is key for managing T&O outbreaks in drinking water reservoirs.


Subject(s)
Ammonium Compounds , Drinking Water , Camphanes , England , Naphthols , Nutrients , Odorants , Taste , Wales
3.
Proc Biol Sci ; 285(1874)2018 03 14.
Article in English | MEDLINE | ID: mdl-29540523

ABSTRACT

Seasonal shifts in environmental conditions provide predictable cues to which organisms can respond in adaptive ways. For example, seasonal changes in temperature can induce phenotypes at different times of the year that have season-specific fitness benefits. Here, we tested the hypothesis that embryo responses to seasonal changes in thermal environments are adaptively matched to the timing of reproduction (environmental-matching hypothesis). We collected eggs of the brown anole lizard (Anolis sagrei) from early and late seasons, and exposed them to early and late thermal regimes that mimic nest temperatures. After measuring offspring morphology and performance, we quantified their survival in the field. Females had higher fecundity, but produced smaller eggs, early in the season compared with late in the season. Late-season eggs exposed to late thermal regimes had relatively high survival, but early-season eggs exposed to early thermal regimes had similar survival rates to those exposed to mismatched conditions. Late-season nest temperatures and late-season eggs produced offspring that were relatively large and fast runners. However, despite phenotypic benefits of late-season conditions, early-season hatchlings had greater survival in the field. Our results do not fully support the environmental-matching hypothesis but suggest that selection favours seasonal shifts in reproductive investment of mothers (high early-season fecundity) over plastic responses of embryos to seasonal environmental changes.


Subject(s)
Environment , Lizards/physiology , Phenotype , Temperature , Animals , Female , Longevity , Male , Reproduction , Seasons
4.
Biol Lett ; 12(10)2016 Oct.
Article in English | MEDLINE | ID: mdl-28120809

ABSTRACT

Embryonic environments influence phenotypic development, but relatively few experiments have explored the effects of natural environmental variation. We incubated eggs of the lizard Anolis sagrei under conditions that mimicked natural spatial and temporal thermal variation to determine their effects on offspring morphology and performance. Incubation temperatures mimicked two microhabitats (open, shade) at two different times of the incubation season (April, July). Egg survival, incubation duration and offspring size were influenced by interactions between habitat- and season-specific nest temperatures, and locomotor performance was influenced primarily by temporal factors. These findings highlight the importance of spatial and temporal environmental variation in generating variation in fitness-related phenotypes.


Subject(s)
Lizards/embryology , Animals , Ecosystem , Embryo, Nonmammalian/physiology , Embryonic Development , Female , Lizards/growth & development , Locomotion , Male , Phenotype , Seasons , Temperature
5.
Nat Genet ; 5(1): 22-30, 1993 Sep.
Article in English | MEDLINE | ID: mdl-8220418

ABSTRACT

Overexpression of the gene encoding the beta-amyloid precursor protein (APP) may have a key role in the pathogenesis of both Alzheimer's disease (AD) and Down Syndrome (DS). We have therefore introduced a 650 kilobase (kb) yeast artificial chromosome (YAC) that contains the entire, unrearranged 400 kb human APP gene into mouse embryonic stem (ES) cells by lipid-mediated transfection. ES lines were generated that contain a stably integrated, unrearranged human APP gene. Moreover, we demonstrate germ line transmission of the APP YAC in transgenic mice and expression of human APP mRNA and protein at levels comparable to endogenous APP. This transgenic strategy may prove invaluable for the development of mouse models for AD and DS.


Subject(s)
Amyloid beta-Protein Precursor/genetics , Recombinant Fusion Proteins/biosynthesis , Amyloid beta-Protein Precursor/biosynthesis , Animals , Base Sequence , Chromosomes, Artificial, Yeast , Gene Expression Regulation , Genes , Genome, Human , Humans , Mice , Mice, Inbred C57BL , Mice, Transgenic , Molecular Sequence Data , Organ Specificity , Polymerase Chain Reaction , Stem Cells
6.
Ophthalmology ; 118(8): 1580-7, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21813090

ABSTRACT

PURPOSE: We studied the 3-year efficacy and safety results of a 4-year study evaluating fluocinolone acetonide (FA) intravitreal implants in eyes with persistent or recurrent diabetic macular edema (DME). DESIGN: Prospective, evaluator-masked, controlled, multicenter clinical trial. PARTICIPANTS: We included 196 eyes with refractory DME. METHODS: Patients were randomized 2:1 to receive 0.59-mg FA implant (n = 127) or standard of care (SOC additional laser or observation; n = 69). The implant was inserted through a pars plana incision. Visits were scheduled on day 2, weeks 1, 3, 6, 12, and 26, and thereafter every 13 weeks through 3 years postimplantation. MAIN OUTCOME MEASURES: The primary efficacy outcome was ≥15-letter improvement in visual acuity (VA) at 6 months. Secondary outcomes included resolution of macular retinal thickening and Diabetic Retinopathy Severity Score (DRSS). Safety measures included incidence of adverse events (AEs). RESULTS: Overall, VA improved ≥3 lines in 16.8% of implanted eyes at 6 months (P=0.0012; SOC, 1.4%); in 16.4% at 1 year (P=0.1191; SOC, 8.1%); in 31.8% at 2 years (P=0.0016; SOC, 9.3%); and in 31.1% at 3 years (P=0.1566; SOC, 20.0%). The number of implanted eyes with no evidence of retinal thickening at the center of the macula was higher than SOC eyes at 6 months (P<0.0001), 1 year (P<0.0001; 72% vs 22%), 2 years (P=0.016), and 3 years (P=0.861). A higher rate of improvement and lower rate of decline in DRSS occurred in the implanted group versus the SOC group at 6 months (P=0.0006), 1 year (P=0.0016), 2 years (P=0.012), and 3 years (P=0.0207). Intraocular pressure (IOP) ≥30 mmHg was recorded in 61.4% of implanted eyes (SOC, 5.8%) at any time and 33.8% required surgery for ocular hypertension by 4 years. Of implanted phakic eyes, 91% (SOC, 20%) had cataract extraction by 4 years. CONCLUSIONS: The FA intravitreal implant met the primary and secondary outcomes, with significantly improved VA and DRSS and reduced DME. The most common AEs included cataract progression and elevated IOP. The 0.59-mg FA intravitreal implant may be an effective treatment for eyes with persistent or recurrent DME. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.


Subject(s)
Diabetic Retinopathy/drug therapy , Fluocinolone Acetonide/administration & dosage , Glucocorticoids/administration & dosage , Macular Edema/drug therapy , Vitreous Body/drug effects , Cataract/chemically induced , Diabetic Retinopathy/diagnosis , Diabetic Retinopathy/physiopathology , Double-Blind Method , Drug Implants , Female , Fluocinolone Acetonide/adverse effects , Fluorescein Angiography , Glucocorticoids/adverse effects , Humans , Intraocular Pressure/drug effects , Intraocular Pressure/physiology , Macular Edema/diagnosis , Macular Edema/physiopathology , Male , Middle Aged , Prospective Studies , Recurrence , Retina/drug effects , Retina/pathology , Tomography, Optical Coherence , Treatment Outcome , Visual Acuity/drug effects , Visual Acuity/physiology
8.
Adv Health Sci Educ Theory Pract ; 15(2): 195-217, 2010 May.
Article in English | MEDLINE | ID: mdl-19760104

ABSTRACT

Education has moved from teacher to student-centred practices. Increasing emphasis is placed on 'life-long' learning in the context of a rapidly changing knowledge base. Self-evaluation is seen as one strategy to facilitate student-centred continuous professional development. The literature, however, suggests that learners' ability to self-assess is mixed, and little is known regarding how students perform self-assessment. This study focussed on senior nurses undertaking a scenario-based clinical skills course. Learners were asked to self-evaluate several times during the course. This research explored the influences on using the self-evaluation exercise. The study drew upon grounded theory methodology and was influenced by constructionist and postmodernist theories. Three methods of data collection were used: semi-structured interviews, observation of supervision sessions and recording of the numerical self-evaluation ratings. Multiple interviews with students (n = 14) and the educational supervisor (n = 1) were conducted. Thematic analysis and data collection were conducted iteratively. The study found that feeling confident and stating that confidence were not necessarily the same. Feeling confident was complex, influenced by changing perceptions of clinical skills and credibility. Changing frames of reference were used to judge feelings of confidence. Stating confidence appeared to be socially negotiated, influenced by social acceptability considerations such as modesty and the need to show progress over time. The discourses of empowerment and surveillance were influential and self-evaluation is discussed using Foucault's theory of governmentality, illustrating how learners can be both empowered and controlled through self-evaluation. Further consideration of the socially constructed nature of self-evaluations would benefit both educational practice and future research.


Subject(s)
Education, Nursing/methods , Self-Assessment , Clinical Competence , Humans , Self Efficacy , Students, Nursing
9.
Nat Commun ; 11(1): 4436, 2020 09 07.
Article in English | MEDLINE | ID: mdl-32895377

ABSTRACT

Despite recent advances, the link between the evolution of atmospheric CO2 and climate during the Eocene greenhouse remains uncertain. In particular, modelling studies suggest that in order to achieve the global warmth that characterised the early Eocene, warmer climates must be more sensitive to CO2 forcing than colder climates. Here, we test this assertion in the geological record by combining a new high-resolution boron isotope-based CO2 record with novel estimates of GlobalĀ MeanĀ Temperature. We find that EquilibriumĀ ClimateĀ Sensitivity (ECS) was indeed higher during the warmest intervals of the Eocene, agreeing well with recent model simulations, and declined through the Eocene as global climate cooled. These observations indicate that the canonical IPCC range of ECS (1.5 to 4.5 Ā°C per doubling) is unlikely to be appropriate for high-CO2 warm climates of the past, and the state dependency of ECS may play an increasingly important role in determining the state of future climate as the Earth continues to warm.

10.
Clin Genet ; 76(1): 63-8, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19659761

ABSTRACT

Sudden death of an infant is a devastating event that needs an explanation. When an explanation cannot be found, the case is labeled as sudden infant death syndrome or unclassified sudden infant death. The influence of genetic factors has been recognized for sudden infant death, but copy number variations (CNVs) as potential risk factors have not been evaluated yet. Twenty-seven families were enrolled in this study. The tissue specimens from deceased children were obtained and array-based comparative genomic hybridization (array-CGH) experiments were performed on the genomic DNA isolated from these specimens using Agilent Technologies Custom 4 x 44K arrays. Quantitative polymerase chain reaction experiments were performed to confirm the overlapping duplication and deletion region in two different cases. A de novo CNV is detected in 3 of 27 cases (11%). In case 1, an approximately 3-Mb (chr 8: 143,211,215-qter) duplication on 8q24.3-qter and a 4.4-Mb deletion on the 22q13.3-qter (chr 22: 45,047,068-qter) were detected. Subtelomeric chromosome analysis of the father and the surviving sibling of case 1 showed a balanced reciprocal translocation, 46,XY,t(8;22)(q24.3;q13.3). A 240-kb (chr 6: 26,139,810-26,380,787) duplication and a 1.9-Mb deletion (chr 6: 26,085,971-27,966,150) at chromosome 6p22 were found in cases 2 and 3, respectively. Array-CGH and conventional cytogenetic studies did not reveal the observed CNVs in the parents and the siblings of cases 2 and 3. The detected CNVs in cases 2 and 3 encompassed several genes including the major histone cluster genes. Array-CGH analysis may be beneficial during the investigations after sudden infant death.


Subject(s)
Gene Dosage , Sudden Infant Death/genetics , Child , Child, Preschool , Comparative Genomic Hybridization , Databases, Genetic , Fatal Outcome , Genome, Human/genetics , Humans , Infant , Infant, Newborn , Software
11.
Science ; 176(4042): 1412-4, 1972 Jun 30.
Article in English | MEDLINE | ID: mdl-17834648

ABSTRACT

A priori quantum mechanical calculations have been carried out at about 150 linear geometries for the fluorine plus hydrogen molecule system. An extended basis set of Gaussian functions was used, and electron correlation was treated explicitly by configuration interaction. Comparison with the experimental activation energy and exothermicity suggests that the theoretical potential surface is quite realistic.

12.
Neuropsychologia ; 46(1): 22-36, 2008 Jan 15.
Article in English | MEDLINE | ID: mdl-17920643

ABSTRACT

Cases of hue-selective dyschomatopsias, together with the results of recent optical imaging studies [Xiao, Y., Casti, A. R. R., Xiao, J., & Kaplan, E. (2006). A spatially organized representation of colour in macaque primary visual cortex. Perception, 35, ECVP Abstract Supplement; Xiao, Y., Wang, Y., & Felleman, D. J. (2003). A spatially organized representation of colour in macaque cortical area V2. Nature, 421, 535-539], have provided support for the idea that different colours are processed in spatially distinct regions of extrastriate cortex. In the present report, we provide evidence suggesting that a similar, but distinct, map may exist for representations of colour in memory. This evidence comes from observations of a young woman (QP) who demonstrates an isolated deficit in colour memory secondary to a concussive episode. Despite having normal colour perception and colour naming skills, and above-average memory skills in other domains, QP's ability to recall visually encoded colour information over short retention intervals is dramatically impaired. Her long-term memory for colour and her colour imagery skills are also abnormal. Surprisingly, however, these impairments are not seen with all hues; specifically, her ability to remember or imagine blue shades is spared. This interesting case contributes to the literature suggesting that colour perception, naming, and memory can be clinically dissociated, and provides insights into the organization of colour information in memory.


Subject(s)
Color Perception/physiology , Color , Memory Disorders/physiopathology , Mental Recall/physiology , Adolescent , Color Perception Tests , Discrimination, Psychological/physiology , Female , Humans , Neuropsychological Tests , Photic Stimulation/methods
13.
Curr Opin Genet Dev ; 1(1): 119-23, 1991 Jun.
Article in English | MEDLINE | ID: mdl-1840870

ABSTRACT

The introduction of the genome database to the human gene mapping community in September 1990 heralded the advent of a new generation of databases to serve the needs of the human genome initiative over the coming years. The databases will act as a fulcrum around which the activities of the human genome initiative can be coordinated at an international level.


Subject(s)
Chromosome Mapping , Databases, Factual , Genome , Animals , Database Management Systems , Human Genome Project , Humans , Mice
14.
Exp Brain Res ; 189(1): 91-8, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18493755

ABSTRACT

Even though there have been extensive investigations of the temporal integration limits of binocular vision in perceptual tasks, relatively little is known about temporal integration limits during the completion of visuomotor tasks. To assess the temporal integration limits of binocular disparity within the action domain, accuracy of reach kinematics in a reaching and grasping task under continuous binocular and monocular viewing conditions were compared with those obtained under alternating monocular viewing conditions with interocular delays ranging from 14 to 58 ms. Even the shortest of the interocular delays resulted in larger grip apertures than those in the continuous monocular and binocular viewing conditions. The short temporal integration interval of stereovision obtained in this study cannot be accounted for by differential visual feedback in the binocular and interocular delay conditions, nor is it likely to be a consequence of visual disruption due to the interocular delays. Our findings suggest that the visuomotor system has little tolerance to interocular delay.


Subject(s)
Hand Strength/physiology , Psychomotor Performance/physiology , Vision Disparity/physiology , Adolescent , Adult , Biomechanical Phenomena , Distance Perception/physiology , Female , Humans , Male , Photic Stimulation/methods
15.
Eur J Echocardiogr ; 9(6): 761-5, 2008 Nov.
Article in English | MEDLINE | ID: mdl-18490290

ABSTRACT

AIMS: Real-time 3D echocardiography (RT3DE) and 2D low mechanical index (LMI), contrast specific, myocardial perfusion imaging are now both accepted techniques. We evaluated the feasibility of an RT3DE LMI implementation in unselected patients. METHODS AND RESULTS: Forty-six patients undergoing contrast enhanced dobutamine stress echo were imaged with novel 3D LMI power modulation software. All patients underwent contrast enhanced 2D and RT3DE acquisitions, in left ventricular opacification (LVO), and LMI perfusion modes. The data sets were evaluated segmentally for wall motion (WM) and myocardial contrast enhancement. Of the 736 evaluated segments, WM could be assessed in 726 (98.6%) of the 2D and 708 (96.2%) 3D segments (P = 0.007). Perfusion could be assessed in 721 (98%) of 2D and 701 (95.2%) of 3D segments (P = 0.006). Six hundred and sixty-one segments had normal WM and thickening in 2D and of these RT3DE demonstrated normal myocardial opacification in 77.2% of basal, 85% of mid, and 91.8% of apical segments. Thirty-four segments were akinetic, with no evidence of perfusion in 2D, and of these RT3DE revealed a perfusion defect in 31 (91%, P = NS). CONCLUSION: LMI RT3DE evaluation of myocardial perfusion is feasible in most segments. It has the potential to accurately locate and possibly quantify perfusion defects.


Subject(s)
Echocardiography, Stress , Echocardiography, Three-Dimensional/methods , Heart Ventricles/diagnostic imaging , Aged , Aged, 80 and over , Feasibility Studies , Female , Humans , Image Enhancement/methods , Male , Middle Aged , Sensitivity and Specificity
16.
Genes Brain Behav ; 6(2): 113-9, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17410640

ABSTRACT

Several putative schizophrenia susceptibility genes have recently been reported, but it is not clear whether these genes are associated with schizophrenia in general or with specific disease subtypes. In a previous study, we found an association of the neuregulin 1 (NRG1) gene with non-deficit schizophrenia only. We now report an association study of four schizophrenia candidate genes in patients with and without deficit schizophrenia, which is characterized by severe and enduring negative symptoms. Single-nucleotide polymorphisms (SNPs) were genotyped in the DTNBP1 (dysbindin), G72/G30 and RGS4 genes, and the relatively unknown PIP5K2A gene, which is located in a region of linkage with both schizophrenia and bipolar disorder. The sample consisted of 273 Dutch schizophrenia patients, 146 of whom were diagnosed with deficit schizophrenia and 580 controls. The strongest evidence for association was found for the A-allele of SNP rs10828317 in the PIP5K2A gene, which was associated with both clinical subtypes (P = 0.0004 in the entire group; non-deficit P = 0.016, deficit P = 0.002). Interestingly, this SNP leads to a change in protein composition. In RGS4, the G-allele of the previously reported SNP RGS4-1 (single and as part of haplotypes with SNP RGS4-18) was associated with non-deficit schizophrenia (P = 0.03) but not with deficit schizophrenia (P = 0.79). SNPs in the DTNBP1 and G72/G30 genes were not significantly associated in any group. In conclusion, our data provide further evidence that specific genes may be involved in different schizophrenia subtypes and suggest that the PIP5K2A gene deserves further study as a general susceptibility gene for schizophrenia.


Subject(s)
Affective Symptoms/genetics , Phosphotransferases (Alcohol Group Acceptor)/genetics , RGS Proteins/genetics , Schizophrenia/genetics , Schizophrenic Psychology , Alleles , Carrier Proteins/genetics , Case-Control Studies , Dysbindin , Dystrophin-Associated Proteins , Genetic Predisposition to Disease , Genetic Variation , Humans , Intracellular Signaling Peptides and Proteins , Lod Score , Polymorphism, Single Nucleotide/genetics , Proteins/genetics , RNA, Messenger , Schizophrenia/classification
17.
Trends Genet ; 16(12): 565-72, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11102707

ABSTRACT

It has been argued that about 4-5% of male adults suffer from infertility due to a genetic causation. From studies in the fruitfly Drosophila, there is evidence that up to 1500 recessive genes contribute to male fertility in that species. Here we suggest that the control of human male fertility is of at least comparable genetic complexity. However, because of small family size, conventional positional cloning methods for identifying human genes will have little impact on the dissection of male infertility. A critical selection of well-defined infertility phenotypes in model organisms, combined with identification of the genes involved and their orthologues in man, might reveal the genes that contribute to human male infertility.


Subject(s)
Infertility, Male/genetics , Adult , Animals , Drosophila/genetics , Humans , Male
18.
Arch Ophthalmol ; 125(11): 1478-85, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17923537

ABSTRACT

OBJECTIVE: To report the incidence and management of elevated intraocular pressure (IOP) in patients with uveitis treated with the fluocinolone acetonide (FA) intravitreal implant. DESIGN: Pooled data from 3 multicenter, double-masked, randomized, controlled, phase 2b/3 clinical trials evaluating the safety and efficacy of the 0.59-mg or 2.1-mg FA intravitreal implant or standard therapy were analyzed. RESULTS: During the 3-year follow-up, 71.0% of implanted eyes had an IOP increase of 10 mm Hg or more than baseline and 55.1%, 24.7%, and 6.2% of eyes reached an IOP of 30 mm Hg or more, 40 mm Hg or more, and 50 mm Hg or more, respectively. Topical IOP-lowering medication was administered in 74.8% of implanted eyes, and IOP-lowering surgeries, most of which were trabeculectomies (76.2%), were performed on 36.6% of implanted eyes. Intraocular pressure-lowering surgeries were considered a success (postoperative IOP of 6-21 mm Hg with or without additional IOP-lowering medication) in 85.1% of eyes at 1 year. The rate of hypotony (IOP

Subject(s)
Fluocinolone Acetonide/administration & dosage , Glucocorticoids/administration & dosage , Intraocular Pressure/drug effects , Ocular Hypertension/chemically induced , Uveitis/drug therapy , Adolescent , Adult , Aged , Aged, 80 and over , Antihypertensive Agents/therapeutic use , Child , Drug Implants , Female , Fluocinolone Acetonide/adverse effects , Follow-Up Studies , Glucocorticoids/adverse effects , Humans , Incidence , Male , Middle Aged , Multicenter Studies as Topic , Ocular Hypertension/drug therapy , Ocular Hypertension/surgery , Randomized Controlled Trials as Topic , Time Factors , Trabeculectomy , Treatment Outcome
19.
Cytogenet Genome Res ; 115(3-4): 198-204, 2006.
Article in English | MEDLINE | ID: mdl-17124401

ABSTRACT

A widely held belief today is that genomics really only started with the DNA sequence information emanating from the genome programs for various organisms, with the human genome playing the leading role. In fact there is a discernable trail stretching for more than a 100 years from the observations of Boveri on tissue instability involving polyploidy in sea urchin embryos and human tumours to the present day. This historical review follows that trail and shows that many theoretical and technical advantages taken for granted in today's genomics era rely heavily on earlier cytogenetic and gene mapping discoveries. Three specific examples of technical developmental paths involving in situ hybridisation, flow-sorting and DNA reassociation kinetics will be explored. In the mid-1980s the two former approaches merged to give rise to several applications of which chromosome painting and chromosome CGH are arguably the most important. The latter developed into array CGH which has now become the pre-eminent method for detecting micro-imbalances in a large number of targets. A competing emerging technology is that of genome-wide SNP typing, which itself is a product of the much earlier RFLP approach linked to DNA sequence information. Do such approaches spell the final demise of the microscope? Perhaps for narrowly defined activities this may occur, but for addressing general questions, microscopic examination will remain pre-eminent.


Subject(s)
Genomics/history , Genetic Techniques , Genome, Human , History, 20th Century , Humans , Nucleic Acid Hybridization , Research/trends , Sequence Analysis, DNA
20.
Cytogenet Genome Res ; 115(3-4): 254-61, 2006.
Article in English | MEDLINE | ID: mdl-17124408

ABSTRACT

We report array-CGH screening of 95 syndromic patients with normal G-banded karyotypes and at least one of the following features: mental retardation, heart defects, deafness, obesity, craniofacial dysmorphisms or urogenital tract malformations. Chromosome imbalances not previously detected in normal controls were found in 30 patients (31%) and at least 16 of them (17%) seem to be causally related to the abnormal phenotypes. Eight of the causative imbalances had not been described previously and pointed to new chromosome regions and candidate genes for specific phenotypes, including a connective tissue disease locus on 2p16.3, another for obesity on 7q22.1-->q22.3, and a candidate gene for the 3q29 deletion syndrome manifestations. The other causative alterations had already been associated with well-defined phenotypes including Sotos syndrome, and the 1p36 and 22q11.21 microdeletion syndromes. However, the clinical features of these latter patients were either not typical or specific enough to allow diagnosis before detection of chromosome imbalances. For instance, three patients with overlapping deletions in 22q11.21 were ascertained through entirely different clinical features, i.e., heart defect, utero-vaginal aplasia, and mental retardation associated with psychotic disease. Our results demonstrate that ascertainment through whole-genome screening of syndromic patients by array-CGH leads not only to the description of new syndromes, but also to the recognition of a broader spectrum of features for already described syndromes. Furthermore, on the technical side, we have significantly reduced the amount of reagents used and costs involved in the array-CGH protocol, without evident reduction in efficiency, bringing the method more within reach of centers with limited budgets.


Subject(s)
Genetic Diseases, Inborn , Genome, Human , Nucleic Acid Hybridization , Adolescent , Child , Child, Preschool , Chromosome Banding , Female , Gene Deletion , Humans , Infant , Male , Mutation , Polymorphism, Genetic , Syndrome
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