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Theresa Lee

Publications and source records attributed to Theresa Lee.

12 recordsLinked to original sources
PubMed2006

Curry consumption and cognitive function in the elderly.

Curcumin, from the curry spice turmeric, has been shown to possess potent antioxidant and antiinflammatory properties and to reduce beta-amyloid and plaque burden in experimental studies, but epidemiologic evidence is lacking. The authors investigated the association between usual curry consumption level and cognitive function in elderly Asians. In a population-based cohort (n = 1,010) of nondemented elderly Asian subjects aged 60-93 years in 2003, the authors compared Mini-Mental State Examination (MMSE) scores for three categories of regular curry consumption, taking into account known sociodemographic, health, and behavioral correlates of MMSE performance. Those who consumed curry "occasionally" and "often or very often" had significantly better MMSE scores than did subjects who "never or rarely" consumed curry. The authors reported tentative evidence of better cognitive performance from curry consumption in nondemented elderly Asians, which should be confirmed in future studies.

Aged↗
PubMed2006

Diagnosis and therapy of primary hypertrophic pyloric stenosis in adults: case report and review of literature.

Adult idiopathic hypertrophic pyloric stenosis (AIHPS) is a misleading anatomic and radio-clinical entity of unknown etiology. Only about 200 cases have been reported in the literature. It is a benign disease resulting from hypertrophy of the circular fibers of the pyloric canal. Despite the recent progress in radiography and endoscopy, it is very hard to define hypertrophic stenosis in adults. Differentiation of primary from secondary pyloric stenosis is frequently a task of the pathologist rather than the surgeon. The main therapy is surgical, although endoscopic dilatation has been tried. There remains controversy over the best surgical approach. A case is reported of a 48-year-old male patient with AIHPS who was subjected to distal gastrectomy. This paper discusses the possible causes of the disorder, the recommended diagnostic steps, and the different surgical approaches.

Biopsy↗
PubMed2005

Generalised anxiety disorder in Singapore: prevalence, co-morbidity and risk factors in a multi-ethnic population.

BACKGROUND: There has been a relative lack of epidemiological data on generalised anxiety disorder (GAD) in Southeast Asia. A previous study reported a lifetime prevalence of 1.5% and highlighted low preference for seeking professional help and consultation by persons suspected to be suffering from mental health problems. The present study is part of a National Mental Health survey of adults conducted from February 2003-March 2004 specifically assessing anxiety and depression in Singapore. In this paper we report on prevalence, co-morbidity and risk factors associated with GAD. METHODS: We interviewed 2,847 households from an ethnically stratified random sample of adults aged 20-59 years who were Singapore citizens or permanent residents. The General Health Questionnaire and Schedule for Clinical Assessment of Neuropsychiatry were administered, which generated Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) diagnoses of GAD. We assessed socio-demographic correlates, life events, medical and other psychiatric co-morbidities related to GAD. RESULTS: Lifetime prevalence of GAD was 3.3%, current prevalence is 3.0%. Female to male ratio is 3.6:1. GAD was significantly associated (p<0.001) with the presence of other psychiatric co-morbidities, including major depressive disorder, dysthymia, panic disorder, agoraphobia and social phobia. Prevalence increased in older individuals, with the odds of association greatest in subjects with three or more co-morbid medical conditions [adjusted odds ratio (OR) 3.66]. Those who had experienced one or more threatening life events showed increased odds of association with GAD. Chinese ethnicity, the divorced and persons from both the upper and the lowest socio-economic status had highest odds of association with GAD. CONCLUSIONS: We challenge established notions that GAD tends to be a disorder of the socially disadvantaged. Life events are important as precipitating factors in GAD, and uniquely different types of events appear to affect both extremes of social classes. High co-morbidity associations with current GAD are grounds for concern. This may suggest failure to seek treatment, hence giving rise to an increase in severity of the primary condition.

Adult↗
PubMed2005

Two different polyketide synthase genes are required for synthesis of zearalenone in Gibberella zeae.

Zearalenone (ZEA) is a polyketide mycotoxin produced by some species of Gibberella/Fusarium and causes hyperestrogenic syndrome in animals. ZEA occurs naturally in cereals infected by Gibberella zeae in temperate regions and threatens animal health. In this study, we report on a set of genes that participate in the biosynthesis of ZEA in G. zeae. Focusing on the non-reducing polyketide synthase (PKS) genes of the G. zeae genome, we demonstrated that PKS13 is required for ZEA production. Subsequent analyses revealed that a continuous, 50 kb segment of DNA carrying PKS13 consisted of three additional open reading frames that were coexpressed as a cluster during the condition for ZEA biosynthesis. These genes, in addition to PKS13, were essential for the ZEA biosynthesis. They include another PKS gene (PKS4) encoding a fungal reducing PKS; zearalenone biosynthesis gene 1 (ZEB1), which shows a high similarity to putative isoamyl alcohol oxidase genes; and ZEB2 whose deduced product carries a conserved, basic-region leucine zipper domain. ZEB1 is responsible for the chemical conversion of beta-zearalenonol (beta-ZOL) to ZEA in the biosynthetic pathway, and ZEB2 controls transcription of the cluster members. Transcription of these genes was strongly influenced by different culture conditions such as nutrient starvations and ambient pH. Furthermore, the same set of genes regulated by ZEB2 was dramatically repressed in the transgenic G. zeae strain with the deletion of PKS13 or PKS4 but not in the ZEB1 deletion strain, suggesting that ZEA or beta-ZOL may be involved in transcriptional activation of the gene cluster required for ZEA biosynthesis in G. zeae. This is the first published report on the molecular characterization of genes required for ZEA biosynthesis.

Amino Acid Sequence↗
PubMed2004

Functional analysis of the homoserine O-acetyltransferase gene and its identification as a selectable marker in Gibberella zeae.

We used restriction enzyme-mediated integration (REMI) to identify a methionine auxotrophic mutant of Gibberella zeae, an important cereal pathogen. In addition to its methionine requirement, the G. zeae REMI mutant designated Z43R3912 showed pleiotropic phenotypes, including reduced virulence on host plants and lack of sexual development. Outcrossing of Z43R3912 with a mat1-1 deletion strain confirmed that the mutation of Z43R3912 was tagged with the hygromycin B resistance marker. The vector insertion site in Z43R3912 was identified within the ORF designated GzmetE, encoding a putative homoserine O-acetyltrasferase (HOA). Gene disruption analyses confirmed that GzmetE was responsible for the pleiotropic phenotypes of Z43R3912. Genetic complementation of the G. zeae methionine auxotroph with an intact copy of the Aspergillus nidulans metE and GzmetE genes suggests that the HOA gene can be used as a selectable marker for transformation of G. zeae.

Acetyltransferases↗
PubMed2004

Qualitative and quantitative PCR methods for detection of three lines of genetically modified potatoes.

Qualitative and quantitative polymerase chain reaction (PCR) methods have been developed for the detection of genetically modified (GM) potatoes. The combination of specific primers for amplification of the promoter region of Cry3A gene, potato leafroll virus replicase gene, and potato virus Y coat protein gene allows to identify each line of NewLeaf, NewLeaf Y, and NewLeaf Plus GM potatoes. Multiplex PCR method was also established for the simple and rapid detection of the three lines of GM potato in a mixture sample. For further quantitative detection, the realtime PCR method has been developed. This method features the use of a standard plasmid as a reference molecule. Standard plasmid contains both a specific region of the transgene Cry3A and an endogenous UDP-glucose pyrophosphorylase gene of the potato. The test samples containing 0.5, 1, 3, and 5% GM potatoes were quantified by this method. At the 3.0% level of each line of GM potato, the relative standard deviations ranged from 6.0 to 19.6%. This result shows that the above PCR methods are applicable to detect GM potatoes quantitatively as well as qualitatively.

Bacillus thuringiensis Toxins↗
PubMed2003

Polymorphism of trichothecene biosynthesis genes in deoxynivalenol- and nivalenol-producing Fusarium graminearum isolates.

Diversity in trichothecene mycotoxin production by 167 isolates of Fusarium graminearum was examined by chemical and molecular methods. Isolates from barley, corn, and wheat grown in Korea produced either deoxynivalenol (DON) or nivalenol (NIV), whereas isolates from corn grown in the United States produced DON only. Southern blotting of MseI-digested genomic DNA's from these isolates was performed using a 0.6-kb fragment of Tri5, a key enzyme for trichothecene production, as a probe. This technique revealed a single-band polymorphism between these isolates, with 1.8- and 2.2-kb bands arising from DON and NIV producers, respectively. The same set of isolates was subjected to previously developed PCR assays using primers derived from Tri7 or Tri13. These assays also revealed a single-band polymorphism between NIV- and DON-producing chemotypes. The polymorphisms at Tri5, Tri7, or Tri13 in all of the US isolates were consistent with their chemotypes as identified by GC-MS. However, for seven Korean isolates, chemical and molecular analyses yielded seemingly inconsistent results. This issue was resolved by Southern blot analysis with the Tri5 probe using two other restriction enzymes and sequence comparison of a 3.8-kb region spanning Tri5. In addition, one of these exceptional isolates was found to carry both DON and NIV chemotype-specific regions, possibly resulting from recombination between the two chemotypes.

Base Sequence↗
PubMed2003

Shifting fungal reproductive mode by manipulation of mating type genes: obligatory heterothallism of Gibberella zeae.

Fungi capable of sexual reproduction use heterothallic (self-sterile) or homothallic (self-fertile) mating strategies. In most ascomycetes, a single mating type locus, MAT, with two alternative forms (MAT1-1 and MAT1-2) called idiomorphs, controls mating ability. In heterothallic ascomycetes, these alternative idiomorphs reside in different nuclei. In contrast, most homothallic ascomycetes carry both MAT1-1 and MAT1-2 in a single nucleus, usually closely linked. An example of the latter is Gibberella zeae, a species that is capable of both selfing and outcrossing. G. zeae is a devastating cereal pathogen of ubiquitous geographical distribution, and also a producer of mycotoxins that threaten human and animal health. We asked whether G. zeae could be made strictly heterothallic by manipulation of MAT. Targeted gene replacement was used to differentially delete MAT1-1 or MAT1-2 from a wild-type haploid MAT1-1; MAT1-2 strain, resulting in MAT1-1; mat1-2, mat1-1; MAT1-2 strains that were self-sterile, yet able to cross to wild-type testers and, more importantly, to each other. These results indicated that differential deletion of MAT idiomorphs eliminates selfing ability of G. zeae, but the ability to outcross is retained. They also indicated that both MAT idiomorphs are required for self-fertility. To our knowledge, this is the first report of complete conversion of fungal reproductive strategy from homothallic to heterothallic by targeted manipulation of MAT. Practically, this approach opens the door to simple and efficient procedures for obtaining sexual recombinants of G. zeae that will be useful for genetic analyses of pathogenicity and other traits, such as the ability to produce mycotoxins.

Crosses, Genetic↗
PubMed2003

Mammalian diurnality: some facts and gaps.

A major factor contributing to the evolution of mammals was their ability to be active during the night, a niche previously underused by terrestrial vertebrates. Diurnality subsequently reemerged multiple times in a variety of independent lineages. This paper reviews some recent data on circadian mechanisms in diurnal mammals and considers general themes that appear to be emerging from this work. Careful examination of behavioral studies suggests that although subtle differences may exist, the fundamental functions of the circadian system are the same, as seems to be the case with respect to the molecular mechanisms of the clock. This suggests that responses to signals originating in the clock must be different, either within the SCN or at its targets or downstream from them. Some features of the SCN vary from species to species, but none of these has been clearly associated with diurnality. The region immediately dorsal to the SCN, which receives substantial input from it, exhibits dramatically different rhythms in nocturnal lab rats and diurnal grass rats. This raises the possibility that it functions as a relay that transforms the signal emitted by the SCN and transmits different patterns to downstream targets in nocturnal and diurnal animals. Other direct targets of the SCN include neurons containing orexin and those containing gonadotropin-releasing hormone, and both of these populations of cells exhibit patterns of rhythmicity that are inverted in at least one diurnal compared to one nocturnal species. The patterns that emerge from the data on diurnality are discussed in terms of the implications they have for the evolution and neural substrates of a day-active way of life.

Animals↗
PubMed2002

Tri13 and Tri7 determine deoxynivalenol- and nivalenol-producing chemotypes of Gibberella zeae.

Gibberella zeae, a major cause of cereal scab, can be divided into two chemotypes based on production of the 8-ketotrichothecenes deoxynivalenol (DON) and nivalenol (NIV). We cloned and sequenced a Tri13 homolog from each chemotype. The Tri13 from a NIV chemotype strain (88-1) is located in the trichothecene gene cluster and carries an open reading frame similar to that of Fusarium sporotrichioides, whereas the Tri13 from a DON chemotype strain (H-11) carries several mutations. To confirm the roles of the Tri13 and Tri7 genes in trichothecene production by G. zeae, we genetically altered toxin production in 88-1 and H-11. In transgenic strains, the targeted deletion of Tri13 from the genome of 88-1 caused production of DON rather than NIV. Heterologous expression of the 88-1 Tri13 gene alone or in combination with the 88-1 Tri7 gene conferred on H-11 the ability to synthesize NIV; in the latter case, 4-acetylnivalenol (4-ANIV) also was produced. These results suggest that Tri13 and Tri7 are required for oxygenation and acetylation of the oxygen at C-4 during synthesis of NIV and 4-ANIV in G. zeae. These functional analyses of the Tri13 and Tri7 genes provide the first clear evidence for the genetic basis of the DON and NIV chemotypes in G. zeae.

Genes, Fungal↗