Comparative chemical profiling of leaf essential oils from Cinnamomum kanehirae and related species using steam distillation and solvent extraction: Implications for plant-based classification

Cinnamomum kanehirae Hayata, belonging to Lauraceae family, is an indigenous and endangered species of considerable economic importance in Taiwan. It plays a crucial role as the host for the economically valuable saprotrophic fungus, Taiwanofungus camphorates. However, accurate species identification poses a challenge due to the similarity in morphological features and frequent natural hybridization with closely related species. Acquiring high-quality and pure leaf oils becomes imperative for precise species identification and producing superior goods. In this study, our objective was to establish methodologies for analyzing the chemical composition of leaf essential oils and subsequently apply this knowledge to differentiate among three Cinnamomum species. Gas chromatography-mass spectrometry (GC/MS) was employed to scrutinize the chemical makeup of leaf essential oils from three closely related species: C. kanehirae, C. micranthum, and C. camphora. We utilized Steam Distillation (SD) and steam distillation-solvent extraction (SDSE) methods, with the SDSE-Hexane approach chosen for optimization, enhancing extraction efficiency and ensuring essential oil purity. Through the SDSE-Hexane method, we identified seventy-four compounds distributed across three major classes: monoterpenes hydrocarbons (0.0-7.0 %), oxygenated monoterpenes (3.8-90.9 %), sesquiterpenes hydrocarbons (0.0-28.3 %), and oxygenated sesquiterpenes (1.6-88.1 %). Our findings indicated the presence of more than one chemotype in both C. kanehirae and C. camphora, whereas no specific chemotype could be discerned in C. micranthum. Furthermore, clustering based on chemotypes allowed for the differentiation of samples from the three species. Notably, we demonstrated that the chemical compositions of grafted C. kanehirae remained largely unaffected by the rootstock. Conversely, natural hybrids between C. kanehirae and C. camphora exhibited profiles more closely aligned with C. kanehirae. The optimized extraction method and the chemotype-based classification system established in this study present valuable tools for essential oil preparation, species identification, and further exploration into the genetic variation of Cinnamomum.

Complete chloroplast genome of Angelica hirsutiflora Liu et al. 1961 (Apiaceae)

Angelica hirsutiflora Liu et al.1961, is a perennial herb in the Apiaceae family that is endemic to Taiwan. In this study, the complete circular chloroplast genome of A. hirsutiflora was reconstructed and annotated using Illumina sequencing. The size of the chloroplast genome is 154,266 bp, consisting of two inverted repeats (IRs, 25,075 bp) separated by a large single-copy region (LSC, 86,569 bp) and a small single-copy region (SSC, 17,547 bp). The GC content of the chloroplast genome is 37.6%. There are 114 different genes in the chloroplast genome of A. hirsutiflora, including 80 protein-coding genes, 30 tRNA genes and four rRNA genes. A maximum-likelihood phylogenetic analysis showed that A. hirsutiflora forms a distinct clade, and separated from other species within the genus Angelica. This study provided insights into the evolutionary relationships among different species of Angelica.

Comparative Study of Heavy Metal Blood Serum Level Between Organic and Conventional Farmers in Eastern Taiwan

Numerous studies have indicated that organic fertilizers (OFer) might contain heavy metals (HMs) that present health risks to organic farmers (OFar). This study compared the concentrations of six HMs (Zn, Ni, Cd, Cu, Pb, Cr) in the blood of two distinct groups of farmers: 30 OFar from a designated organic area in eastern Taiwan, and 74 conventional farmers (CFar) from neighboring non-organic designated regions. The findings revealed that the OFar exhibited higher levels of Zn (1202.70 ± 188.74 μg/L), Cr (0.20 ± 0.09 μg/L), and Ni (2.14 ± 1.48 μg/L) in their blood compared to the CFar (988.40 ± 163.16 μg/L, 0.18 ± 0.15 μg/L, and 0.77 ± 1.23 μg/L), respectively. The disparities in Zn, Cr, and Ni levels were measured at 214.3 μg/L, 0.02 μg/L, and 1.37 μg/L, respectively. Furthermore, among the OFar, those who utilized green manures (GM) displayed significantly elevated blood levels of Zn (1279.93 ± 156.30 μg/L), Cr (0.24 ± 0.11 μg/L), and Ni (1.94 ± 1.38 μg/L) compared to individuals who exclusively employed chemical fertilizers (CFer) (975.42 ± 165.35 μg/L, 0.19 ± 0.16 μg/L, and 0.74 ± 1.20 μg/L), respectively. The differences in Zn, Cr, and Ni levels were measured at 304.51 μg/L, 0.05 μg/L, and 1.20 μg/L, respectively. As a result, OFar should be careful in choosing OFer and avoid those that may have heavy metal contamination.

A taxonomic revision of the genus Angelica (Apiaceae) in Taiwan with a new species A. aliensis

BACKGROUND

Angelica L. sensu lato is a taxonomically complex genus, and many studies have utilized morphological and molecular features to resolve its classification issues. In Taiwan, there are six taxa within Angelica, and their taxonomic treatments have been a subject of controversy. In this study, we conducted a comprehensive analysis incorporating morphological and molecular (cpDNA and nrDNA) characteristics to revise the taxonomic treatments of Angelica in Taiwan.

RESULTS

As a result of our research, we have revised the classification between A. dahurica var. formosana and A. pubescens and merged two varieties of A. morrisonicola into a single taxon. A new taxon, A. aliensis, has been identified and found to share a close relationship with A. tarokoensis. Based on the morphological and molecular characteristics data, it has been determined that the former three taxa should be grouped into the Eurasian Angelica clade, while the remaining four taxa should belong to the littoral Angelica clade. Furthermore, Angelica species in Taiwan distributed at higher altitudes displayed higher genetic diversity, implying that the central mountain range of Taiwan serves as a significant reservoir of plant biodiversity. Genetic drift, such as bottlenecks, has been identified as a potential factor leading to the fixation or reduction of genetic diversity of populations in most Angelica species. We provide key to taxa, synopsis, phenology, and distribution for each taxon of Taiwan.

CONCLUSIONS

Our comprehensive analysis of morphological and molecular features has shed light on the taxonomic complexities within Angelica in Taiwan, resolving taxonomic issues and providing valuable insights into the phylogenetic relationships of Angelica in Taiwan.

Genetic Diversity and Population Structure in Captive Populations of Formosan Sambar Deer (Rusa unicolor swinhoei)

Formosan sambar deer (Rusa unicolor swinhoei) are of great economic significance in Taiwan, resulting in a substantial increase in deer farming to meet the high demand for velvet antlers. Inbreeding depression and reduced genetic variability can lead to the deterioration of captive populations. In this study, 239 Formosan sambar deer were genotyped using 13 microsatellites to analyze their genetic diversity and population genetic structure. Our results indicate a high-resolution power of these microsatellites in individual discrimination and parentage analysis. However, captive populations exhibit a low level of genetic diversity, likely because of inbreeding and bottleneck effects. Both principal coordinate analysis (PCoA) and STRUCTURE analyses revealed two distinct and segregated genetic groups within the captive populations and indicated no clear population genetic structure among the captive populations. Introducing new genetic material from the wild through translocation offers a potential solution for mitigating the impact of inbreeding and enhancing genetic diversity. The comprehensive information obtained from these genetic analyses is crucial for the development of effective breeding strategies aimed at preserving and enhancing Formosan sambar deer populations.

New insights into polyploid evolution and dynamic nature of Ludwigia section Isnardia (Onagraceae)

BACKGROUND

While polyploids are common in plants, the evolutionary history and natural dynamics of most polyploid groups are still unclear. Owing to plentiful earlier systematic studies, Ludwigia sect. Isnardia (comprising 22 wetland taxa) is an ideal allopolyploid complex to investigate polyploid evolution and natural dynamics within and among taxa. With a considerable sampling, we concentrated on revisiting earlier phylogenies of Isnardia, reevaluating the earlier estimated age of the most recent common ancestor (TMRCA), exploring the correlation between infraspecific genetic diversity and ploidy levels, and inspecting interspecific gene flows among taxa.

RESULTS

Phylogenetic trees and network concurred with earlier phylogenies and hypothesized genomes by incorporating 192 atpB-rbcL and ITS sequences representing 91% of Isnardia taxa. Moreover, we detected three multi-origin taxa. Our findings on L. repens and L. sphaerocarpa were consistent with earlier studies; L. arcuata was reported as a multi-origin taxon here, and an additional evolutionary scenario of L. sphaerocarpa was uncovered, both for the first time. Furthermore, estimated Isnardia TMRCA ages based on our data (5.9 or 8.9 million years ago) are in accordance with earlier estimates, although younger than fossil dates (Middle Miocene). Surprisingly, infraspecific genetic variations of Isnardia taxa did not increase with ploidy levels as anticipated from many other polyploid groups. In addition, the exuberant, low, and asymmetrical gene flows among Isnardia taxa indicated that the reproductive barriers may be weakened owing to allopolyploidization, which has rarely been reported.

CONCLUSIONS

The present research gives new perceptions of the reticulate evolution and dynamic nature of Isnardia and points to gaps in current knowledge about allopolyploid evolution.

Effect of dietary supplementation of Bacillus subtilis TLRI 211-1 on laying performance, egg quality and blood characteristics of Leghorn layers

OBJECTIVE

TLRI 211-1 is a novel Bacillus subtilis strain. This experiment was to investigate dietary supplementation of TLRI 211-1 on laying performance, egg quality and blood characteristics of layers.

METHODS

One hundred and twenty 65-wk-old Leghorn layers were divided into four treatment groups for 8 weeks experiment. Each treatment had three replicates. The basal diet was formulated as control group with crude protein 17% and metabolizable energy 2,850 kcal/kg and supplemented with TLRI 211-1 0.1%, 0.3%, and commercial Bacillus amyloliquefaciens 0.1% as treatment 2, 3 and 4 groups, respectively. Both TLRI 211-1 and commercial Bacillus amyloliquefaciens were adjusted to contain 1×109 colony-forming unit (CFU)/mL (g), hence the 0.1% supplemental level was 1×109 CFU/kg.

RESULTS

The results showed that TLRI 211-1 0.3% and commercial B. amyloliquefaciens groups had higher weight gain than the other groups; TLRI 211-1 0.1% group had better feed to eggs conversion ratio than the control and commercial B. amyloliquefaciens groups (p<0.05). Bacillus subtilis supplementation increased yolk weight (p<0.05). In egg quality during storage, TLRI 211-1 0.1% had higher breaking strength than the control group at the second week of storage (p<0.05). At the third week of storage, TLRI 211-1 0.3% had higher Haugh unit (p<0.05). Hens fed diets supplemented with TLRI 211-1 0.3% significantly decreased blood triglyceride levels and increased blood calcium levels (p< 0.05). TLRI 211-1 0.3% group had lower H2S (p<0.05) and hence had less unpleasant odor in excreta of hens.

CONCLUSION

In conclusion, supplementation with 0.1% TLRI 211-1 can significantly improve feed to eggs conversion ratio. TLRI 211-1 supplementation also can maintain eggs at their optimum quality level during storage. The study showed that B. subtilis TLRI 211-1 can be used as feed additives for improving egg production performance and egg quality.

Effect of geographic isolation on genetic variation and population structure of Euphrasia nankotaizanensis, a threatened endemic alpine herb in Taiwan

Euphrasia nankotaizanensis (Orobanchaceae) is a rare alpine herb that is endemic to Taiwan. Only four small populations remain in Xue, Nanhu, and Cilai Mountains of Taiwan. The distribution of alpine herbs is severely threatened by climate change, which influences genetic variation and population structure. In this study, we investigated the effects of the natural isolation of alpine habitats on the genetic diversity and geographic structure of populations of E. nankotaizanensis using chloroplast (cp) and nuclear DNA (nrDNA) markers. We found lower levels of genetic diversity in E. nankotaizanensis than in other alpine plants and little to no genetic variation within populations, which could be mainly attributed to the small population size and genetic drift. Only one nrDNA haplotype was present in each population. The lack of monophyly of the four populations in cpDNA probably resulted from lineage sorting or occasional long-distance seed dispersal. Phylogeographic analysis suggested that Nanhu Mountain was probably a refugium over the glacial maxima, agreeing with the potential refugia in central Taiwan. The STRUCTURE and AMOVA analyses revealed significant genetic differentiation in nrDNA among the mountains, which resulted from geographical isolation among these mountains. Estimates of the effective population size (Ne) and demography reflected lower Ne values and a recent population decline, probably implying a greater extinction risk for E. nankotaizanensis. We observed genetic depletion and considerable genetic differentiation among mountain populations, which should be considered in future conservation efforts for this species. In addition, this study provides important insights into the long-term potential of alpine herbs in Taiwan, which are useful for a better prediction of their responses to future climate change.

Complete chloroplast genome and phylogenetic analysis of Bupleurum kaoi Liu, Chao, and Chuang, 1977: an endemic species in Taiwan

Bupleurum kaoi Liu, Chao, and Chuang is an endemic and endangered herb in Taiwan. In this study, the complete circular chloroplast genome of B. kaoi was reconstructed and annotated using Illumina sequencing. The genome size of B. kaoi is 155,938 bp, including a pair of inverted repeat regions (IRs: 26308 bp), separated by a large single-copy (LSC) region of 85,784 bp and a small single-copy (SSC) region of 17,538 bp. The GC content of the chloroplast genome is 37.6%. There are 113 different genes in the chloroplast genome of B. kaoi, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. A maximum-likelihood phylogenetic analysis showed that Bupleurum species is the monophyletic group, and B. kaoi belongs to subgenus Bupleurum and is closely related to B. scorzonerifolium.

Complete mitogenome of Antheraea formosana Sonan, 1937 (Lepidoptera: Saturniidae): an endemic silkmoth in Taiwan

The complete mitogenome of an endemic silkmoth in Taiwan, Antheraea formosana, was determined using Illumina next-generation sequencing. The mitogenome is 15,318 bp in length and consists of 13 protein-coding genes (PCGs), two rRNAs, 22 tRNAs, and one non-coding control region. The overall base composition of the mitogenome showed a high A + T bias, and the A + T content (80.2%) was significantly higher than the G + C content (19.8%). All PCGs use the typical ATN as the initiation codon, with the exception of cox2, which begins with GTG, respectively. The complete mitogenome was used to reconstruct a phylogenetic tree, indicating that A. formosana is more closely related to Antheraea assamensis than other Antheraea species, with 93.19% nucleotide similarity.

Complete mitochondrial genome of Manispentadactylapentadactyla (Mammalia: Pholidota), an endemic subspecies of Chinese pangolin: mitogenome characterisation and phylogenetic implications

The Chinese pangolin Manispentadactyla is critically endangered because of over-exploitation and illegal trafficking and includes three subspecies. However, the taxonomic status of the three subspecies of the Chinese pangolin has not been well resolved, which impedes regional conservation and illegal trade traces. In this study, the complete mitogenome sequence of M.p.pentadactyla, an endemic subspecies of the Chinese pangolin in Taiwan, was determined. The complete mitogenome of M.p.pentadactyla is 16,570 base pairs (bp) in length with 13 protein-coding genes (PCG), 23 transfer RNAs (tRNAs), two ribosomal RNAs and a 1164 bp control region. The overall base composition of the genome showed a slight A + T bias (59.9%), positive AT skew (0.1515) and negative GC skew (-0.3406), which is similar to that of other pangolins. All PCGs started with a typical ATN codon and all tRNAs were typical cloverleaf-shaped secondary structures, except for tRNA-Ser^(GCU). Phylogenetic analysis indicated a monophyletic relationship for M.p.pentadactyla and M.p.aurita and was monophyletic for M.p.pentadactyla, but paraphyletic for M.p.aurita. The paraphyly of M.p.aurita resulted from an incomplete lineage sorting. This study enriched the mitogenome database of the Chinese pangolin and the molecular information obtained should be very useful for future research on mitogenome evolution and genetic diversification in M.pentadactyla.

The Ameliorative Effects of Fucoidan in Thioacetaide-Induced Liver Injury in Mice

Liver disorders have been recognized as one major health concern. Fucoidan, a sulfated polysaccharide extracted from the brown seaweed Fucus serratus, has previously been reported as an anti-inflammatory and antioxidant. However, the discovery and validation of its hepatoprotective properties and elucidation of its mechanisms of action are still unknown. The objective of the current study was to investigate the effect and possible modes of action of a treatment of fucoidan against thioacetamide (TAA)-induced liver injury in male C57BL/6 mice by serum biochemical and histological analyses. The mouse model for liver damage was developed by the administration of TAA thrice a week for six weeks. The mice with TAA-induced liver injury were orally administered fucoidan once a day for 42 days. The treated mice showed significantly higher body weights; food intakes; hepatic antioxidative enzymes (catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD)); and a lower serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and C-reactive protein (CRP) levels. Additionally, a reduced hepatic IL-6 level and a decreased expression of inflammatory-related genes, such as cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) mRNA was observed. These results demonstrated that fucoidan had a hepatoprotective effect on liver injury through the suppression of the inflammatory responses and acting as an antioxidant. In addition, here, we validated the use of fucoidan against liver disorders with supporting molecular data.

Frequent gene flow blurred taxonomic boundaries of sections in Lilium L. (Liliaceae)

Gene flow between species may last a long time in plants. Reticulation inevitably causes difficulties in phylogenetic reconstruction. In this study, we looked into the genetic divergence and phylogeny of 20 Lilium species based on multilocus analyses of 8 genes of chloroplast DNA (cpDNA), the internally transcribed nuclear ribosomal DNA (nrITS) spacer and 20 loci extracted from the expressed sequence tag (EST) libraries of L. longiflorum Thunb. and L. formosanum Wallace. The phylogeny based on the combined data of the maternally inherited cpDNA and nrITS was largely consistent with the taxonomy of Lilium sections. This phylogeny was deemed the hypothetical species tree and uncovered three groups, i.e., Cluster A consisting of 4 taxa from the sections Pseudolirium and Liriotypus, Cluster B consisting of the 4 taxa from the sections Leucolirion, Archelirion and Daurolirion, and Cluster C comprising 10 taxa mostly from the sections Martagon and Sinomartagon. In contrast, systematic inconsistency occurred across the EST loci, with up to 19 genes (95%) displaying tree topologies deviating from the hypothetical species tree. The phylogenetic incongruence was likely attributable to the frequent genetic exchanges between species/sections, as indicated by the high levels of genetic recombination and the IMa analyses with the EST loci. Nevertheless, multilocus analysis could provide complementary information among the loci on the species split and the extent of gene flow between the species. In conclusion, this study not only detected frequent gene flow among Lilium sections that resulted in phylogenetic incongruence but also reconstructed a hypothetical species tree that gave insights into the nature of the complex relationships among Lilium species.

Multilocus Analyses Reveal Postglacial Demographic Shrinkage of Juniperus morrisonicola (Cupressaceae), a Dominant Alpine Species in Taiwan

Postglacial climate changes alter geographical distributions and diversity of species. Such ongoing changes often force species to migrate along the latitude/altitude. Altitudinal gradients represent assemblage of environmental, especially climatic, variable factors that influence the plant distributions. Global warming that triggered upward migrations has therefore impacted the alpine plants on an island. In this study, we examined the genetic structure of Juniperus morrisonicola, a dominant alpine species in Taiwan, and inferred historical, demographic dynamics based on multilocus analyses. Lower levels of genetic diversity in north indicated that populations at higher latitudes were vulnerable to climate change, possibly related to historical alpine glaciers. Neither organellar DNA nor nuclear genes displayed geographical subdivisions, indicating that populations were likely interconnected before migrating upward to isolated mountain peaks, providing low possibilities of seed/pollen dispersal across mountain ranges. Bayesian skyline plots suggested steady population growth of J. morrisonicola followed by recent demographic contraction. In contrast, most lower-elevation plants experienced recent demographic expansion as a result of global warming. The endemic alpine conifer may have experienced dramatic climate changes over the alternation of glacial and interglacial periods, as indicated by a trend showing decreasing genetic diversity with the altitudinal gradient, plus a fact of upward migration.

Association of heat shock protein 70 gene polymorphisms with acute thermal tolerance, growth, and egg production traits of native chickens in Taiwan

Abstract. Heat stress is among the most challenging environmental conditions affecting commercial poultry. It severely affects growth and egg production, particularly in tropical and subtropical regions. This study aimed to examine physiological responses – including triiodothyronine (T3) levels, enzymatic activity of creatine kinase (CK) and lactate dehydrogenase (LDH), respiratory rates, and cloacal temperature – to acute heat stress associated with different genotypes of the HSP70 gene and to evaluate the association of these polymorphisms with growth and egg production. Genotyping was performed by single-strand conformation polymorphism analysis. The polymorphisms identified were A258A, A258G, and G258G. Twenty 12-week old birds were randomly selected from each genotype and exposed to 40 °C ambient temperature for 1 h. Blood samples were collected at 0 and 1 h following heat stress. Respiratory rate and cloacal temperature were measured following 0, 30, and 60 min of exposure. After 1 h, the A258A genotype exhibited lower levels of CK activity and plasma T3. Neither respiratory rate nor cloacal temperature displayed a significant association with the genotypes. Body weight gain differed among the genotypes for males (F =  3.268, P = 0.041) and females (F =  14.029, P < 0.001), and the A258A genotype exhibited the greatest weight gain at 0–16 weeks of age for both genders. There were no significant differences among genotypes regarding egg weight at first egg or the number of eggs laid until 40 weeks of age. The A258A genotype displayed higher heat tolerance with no negative effects on growth performance and egg production.

Cross-Species, Amplifiable EST-SSR Markers for Amentotaxus Species Obtained by Next-Generation Sequencing

Amentotaxus, a genus of Taxaceae, is an ancient lineage with six relic and endangered species. Four Amentotaxus species, namely A. argotaenia, A. formosana, A. yunnanensis, and A. poilanei, are considered a species complex because of their morphological similarities. Small populations of these species are allopatrically distributed in Asian forests. However, only a few codominant markers have been developed and applied to study population genetic structure of these endangered species. In this study, we developed and characterized polymorphic expressed sequence tag-simple sequence repeats (EST-SSRs) from the transcriptome of A. formosana. We identified 4955 putative EST-SSRs from 68,281 unigenes as potential molecular markers. Twenty-six EST-SSRs were selected for estimating polymorphism and transferability among Amentotaxus species, of which 23 EST-SSRs were polymorphic within Amentotaxus species. Among these, the number of alleles ranged from 1-4, the polymorphism information content ranged from 0.000-0.692, and the observed and expected heterozygosity were 0.000-1.000 and 0.080-0.740, respectively. Population genetic structure analyses confirmed that A. argotaenia and A. formosana were separate species and A. yunnanensis and A. poilanei were the same species. These novel EST-SSRs can facilitate further population genetic structure research of Amentotaxus species.

Inferring multiple refugia and phylogeographical patterns in Pinus massoniana based on nucleotide sequence variation and DNA fingerprinting

BACKGROUND

Pinus massoniana, an ecologically and economically important conifer, is widespread across central and southern mainland China and Taiwan. In this study, we tested the central-marginal paradigm that predicts that the marginal populations tend to be less polymorphic than the central ones in their genetic composition, and examined a founders' effect in the island population.

METHODOLOGY/PRINCIPAL FINDINGS

We examined the phylogeography and population structuring of the P. massoniana based on nucleotide sequences of cpDNA atpB-rbcL intergenic spacer, intron regions of the AdhC2 locus, and microsatellite fingerprints. SAMOVA analysis of nucleotide sequences indicated that most genetic variants resided among geographical regions. High levels of genetic diversity in the marginal populations in the south region, a pattern seemingly contradicting the central-marginal paradigm, and the fixation of private haplotypes in most populations indicate that multiple refugia may have existed over the glacial maxima. STRUCTURE analyses on microsatellites revealed that genetic structure of mainland populations was mediated with recent genetic exchanges mostly via pollen flow, and that the genetic composition in east region was intermixed between south and west regions, a pattern likely shaped by gene introgression and maintenance of ancestral polymorphisms. As expected, the small island population in Taiwan was genetically differentiated from mainland populations.

CONCLUSIONS/SIGNIFICANCE

The marginal populations in south region possessed divergent gene pools, suggesting that the past glaciations might have low impacts on these populations at low latitudes. Estimates of ancestral population sizes interestingly reflect a recent expansion in mainland from a rather smaller population, a pattern that seemingly agrees with the pollen record.

Footprints of natural and artificial selection for photoperiod pathway genes in Oryza

Asian rice, Oryza sativa, consists of two major subspecies, indica and japonica, which are physiologically differentiated and adapted to different latitudes. Genes for photoperiod sensitivity are likely targets of selection along latitude. We examined the footprints of natural and artificial selections for four major genes of the photoperiod pathway, namely PHYTOCHROME B (PhyB), HEADING DATE 1 (Hd1), HEADING DATE 3a (Hd3a), and EARLY HEADING DATE 1 (Ehd1), by investigation of the patterns of nucleotide polymorphisms in cultivated and wild rice. Geographical subdivision between tropical and subtropical O. rufipogon was found for all of the photoperiod genes in plants divided by the Tropic of Cancer (TOC). All of these genes, except for PhyB, were characterized by the existence of clades that split a long time ago and that corresponded to latitudinal subdivisions, and revealed a likely diversifying selection. Ssp. indica showed close affinity to tropical O. rufipogon for all genes, while ssp. japonica, which has a much wider range of distribution, displayed complex patterns of differentiation from O. rufipogon, which reflected various agricultural needs in relation to crop yield. In japonica, all genes, except Hd3a, were genetically differentiated at the TOC, while geographical subdivision occurred at 31°N in Hd3a, probably the result of varying photoperiods. Many other features of the photoperiod genes revealed domestication signatures, which included high linkage disequilibrium (LD) within genes, the occurrence of frequent and recurrent non-functional Hd1 mutants in cultivated rice, crossovers between subtropical and tropical alleles of Hd1, and significant LD between Hd1 and Hd3a in japonica and indica.

Characterization of microsatellite loci from Litsea hypophaea (Lauraceae), a tree endemic to Taiwan

PREMISE OF THE STUDY

Microsatellite primers were developed for the endemic tree Litsea hypophaea (Lauraceae) in Taiwan to investigate its genetic diversity and population genetic structure and to investigate species delimitation within Litsea.

METHODS AND RESULTS

Fifteen new simple sequence repeat markers were developed from L. hypophaea with a magnetic bead enrichment method. Most loci were also amplified from three closely related species, L. coreana, L. lii, and L. acutivena. The number of alleles and observed and expected heterozygosities across loci varied with a range of 1-25, 0.000-1.000, and 0.000-0.956, respectively.

CONCLUSIONS

The application of these microsatellite markers of L. hypophaea provides a tool for understanding genetic diversity and population differentiation. In addition, interspecific amplification suggests that these markers will also be useful for species identification of related taxa within Litsea in Taiwan.

Isolation and characterization of 15 microsatellite loci in four endangered Amentotaxus species (Taxaceae)

PREMISE OF THE STUDY

Fifteen microsatellite loci were developed in an endangered species, Amentotaxus formosana, and were tested in an additional three species, A. argotaenia, A. yunnanensis, and A. poilanei, to evaluate the population structure for conservation efforts and reconstruct the phylogeographic patterns of this ancient lineage.

METHODS AND RESULTS

Polymorphic primer sets were developed from A. formosana; the number of alleles ranged from two to 10, with an observed heterozygosity ranging from 0 to 0.60. All of the loci were found to be interspecifically amplifiable.

CONCLUSIONS

These polymorphic and transferable loci will be potentially useful for future studies that will focus on identifying distinct genetic units within species and establishing the phylogeographic patterns and the process of speciation among closely related species.

Genetic population structure of the alpine species Rhododendron pseudochrysanthum sensu lato (Ericaceae) inferred from chloroplast and nuclear DNA

Background

A complex of incipient species with different degrees of morphological or ecological differentiation provides an ideal model for studying species divergence. We examined the phylogeography and the evolutionary history of the Rhododendron pseudochrysanthum s. l.

Results

Systematic inconsistency was detected between gene genealogies of the cpDNA and nrDNA. Rooted at R. hyperythrum and R. formosana, both trees lacked reciprocal monophyly for all members of the complex. For R. pseudochrysanthum s.l., the spatial distribution of the cpDNA had a noteworthy pattern showing high genetic differentiation (F_ST = 0.56-0.72) between populations in the Yushan Mountain Range and populations of the other mountain ranges.

Conclusion

Both incomplete lineage sorting and interspecific hybridization/introgression may have contributed to the lack of monophyly among R. hyperythrum, R. formosana and R. pseudochrysanthum s.l. Independent colonizations, plus low capabilities of seed dispersal in current environments, may have resulted in the genetic differentiation between populations of different mountain ranges. At the population level, the populations of Central, and Sheishan Mountains may have undergone postglacial demographic expansion, while populations of the Yushan Mountain Range are likely to have remained stable ever since the colonization. In contrast, the single population of the Alishan Mountain Range with a fixed cpDNA haplotype may have experienced bottleneck/founder's events.

Population structure of Nouelia insignis (Asteraceae), an endangered species in southwestern China, based on chloroplast DNA sequences: recent demographic shrinking

Nouelia insignis, an endangered species, is distributed in the Jinsha and Nanpan drainage areas in southwestern China. In this study, we examined the genetic diversity and population structure based on the sequences of the cpDNA rpL 16 intron. Low levels of genetic variation were detected within all populations of the endemic species. A gene genealogy of 11 haplotypes recovered two major lineages I and II, with haplotypes H1 and H6 nested as interior nodes, respectively. Haplotype H1 was widespread in all populations, while haplotype H6 was restricted to populations southern of the Jinsha River. Low levels of genetic differentiation were detected, as most F (st) values between populations were zero. This result, however, contradicts previous studies based on allozymes and fingerprinting. Genetic analyses suggested that coancestry due to low evolutionary rates resulted in the lack of geographical subdivision. Molecular dating estimated that the two lineages split about 3.224 MYA (95% CI 1.070-6.089 MYA). Maintenance of ancestral polymorphisms was possibly attributable to a long-standing large effective population size until recently. Postglacial demographic expansion was supported by a unimodal mismatch distribution and star-like phylogenies.

Conservation genetics and phylogeography of endangered and endemic shrub Tetraena mongolica (Zygophyllaceae) in Inner Mongolia, China

Background

Tetraena mongolica (Zygophyllaceae), an endangered endemic species in western Inner Mongolia, China. For endemic species with a limited geographical range and declining populations, historical patterns of demography and hierarchical genetic structure are important for determining population structure, and also provide information for developing effective and sustainable management plans. In this study, we assess genetic variation, population structure, and phylogeography of T. mongolica from eight populations. Furthermore, we evaluate the conservation and management units to provide the information for conservation.

Results

Sequence variation and spatial apportionment of the atpB-rbcL noncoding spacer region of the chloroplast DNA were used to reconstruct the phylogeography of T. mongolica. A total of 880 bp was sequenced from eight extant populations throughout the whole range of its distribution. At the cpDNA locus, high levels of genetic differentiation among populations and low levels of genetic variation within populations were detected, indicating that most seed dispersal was restricted within populations.

Conclusions

Demographic fluctuations, which led to random losses of genetic polymorphisms from populations, due to frequent flooding of the Yellow River and human disturbance were indicated by the analysis of BEAST skyline plot. Nested clade analysis revealed that restricted gene flow with isolation by distance plus occasional long distance dispersal is the main evolutionary factor affecting the phylogeography and population structure of T. mongolica. For setting a conservation management plan, each population of T. mongolica should be recognized as a conservation unit.

Multilocus analysis of genetic divergence between outcrossing Arabidopsis species: evidence of genome-wide admixture

• Outcrossing Arabidopsis species that diverged from their inbreeding relative Arabidopsis thaliana 5 million yr ago and display a biogeographical pattern of interspecific sympatry vs intraspecific allopatry provides an ideal model for studying impacts of gene introgression and polyploidization on species diversification. • Flow cytometry analyses detected ploidy polymorphisms of 2× and 4× in Arabidopsis lyrata ssp. kamchatica of Taiwan. Genomic divergence between species/subspecies was estimated based on 98 randomly chosen nuclear genes. Multilocus analyses revealed a mosaic genome in diploid A. l. kamchatica composed of Arabidopsis halleri-like and A. lyrata-like alleles. • Coalescent analyses suggest that the segregation of ancestral polymorphisms alone cannot explain the high inconsistency between gene trees across loci, and that gene introgression via diploid A. l. kamchatica likely distorts the molecular phylogenies of Arabidopsis species. However, not all genes migrated across species freely. Gene ontology analyses suggested that some nonmigrating genes were constrained by natural selection. • High levels of estimated ancestral polymorphisms between A. halleri and A. lyrata suggest that gene flow between these species has not completely ceased since their initial isolation. Polymorphism data of extant populations also imply recent gene flow between the species. Our study reveals that interspecific gene flow affects the genome evolution in Arabidopsis.

Paraphyly of organelle DNAs in Cycas Sect. Asiorientales due to ancient ancestral polymorphisms

Background

This study addresses the apportionment of genetic diversity between Cycas revoluta and C. taitungensis, species that constitute the section Asiorientales and represent a unique, basal lineage of the Laurasian genus Cycas. Fossil evidence indicates divergence of the section from the rest of Cycas at least 30 million years ago. Geographically, C. taitungensis is limited to Taiwan whereas C. revoluta is found in the Ryukyu Archipelago and on mainland China.

Results

The phylogenies of ribosomal ITS region of mtDNA and the intergenic spacer between atpB and rbcL genes of cpDNA were reconstructed. Phylogenetic analyses revealed paraphyly of both loci in the two species and also in the section Asiorientales. The lack of reciprocal monophyly between these long isolated sections is likely due to persistent shared ancestral polymorphisms. Molecular dating estimated that mt- and cp DNA lineages coalesced to the most recent common ancestors (TMRCA) about 327 (mt) and 204 MYA (cp), corresponding with the divergence of cycad sections in the Mesozoic.

Conclusion

Fates of newly derived mutations of cycads follow Klopfstein et al.'s surfing model where the majority of new mutations do not spread geographically and remain at low frequencies or are eventually lost by genetic drift. Only successful 'surfing mutations' reach very high frequencies and occupy a large portion of a species range. These mutations exist as dominant cytotypes across populations and species. Geographical subdivision is lacking in both species, even though recurrent gene flow by both pollen and seed is severely limited. In total, the contrasting levels between historical and ongoing gene flow, large population sizes, a long lifespan, and slow mutation rates in both organelle DNAs have all likely contributed to the unusually long duration of paraphyly in cycads.

Isolation and characterization of polymorphic microsatellite loci from Areca catechu (Arecaceae) using PCR-based isolation of microsatellite arrays

Betel nut (Areca nut, Areca catechu L.) is a conspicuous and important cultivated plant of tropical and subtropical habitats throughout Southeast Asia and Oceania. As a significant cultural and social offering, the migration of betel nut associated with human dispersal is an important issue in ethnobotany and anthropology. In this study, we described the development of nine microsatellite loci from A. catechu. The number of alleles per locus ranged from 5 to 15. The expected and observed heterozygosities ranged from 0.71to 0.94 and from 0 to 0.88, respectively. All microsatellite loci, except for AC30, significantly deviated from Hardy-Weinberg equilibrium possibly due to artificially selected cultivation or the existence of excessive null alleles. No linkage disequilibrium was observed from pairwise comparisons of loci, except for AC06 and AC08.

Five subgenotypes of hepatitis B virus genotype B with distinct geographic and virological characteristics

Several hepatitis B virus (HBV) subgenotypes, HBV/A1, A2, Bj and Ba, have been reported with respect to clinical differences among patients infected with these subgenotypes. The population genetics and phylogeography of HBV were investigated based on the complete genome sequences of 484 isolates with 108 from our chronic hepatitis B patients and the remaining from the GenBank database. Besides genotypes A-H (HBV/A-H), five subgenotypes were identified among 169 HBV/B isolates by phylogenetic analysis and nucleotide divergence. There were 27 isolates of subgenotype B(1) (HBV/B(1)) restricted to Japan, 104 isolates of HBV/B(2) with the widest distribution in most Asian countries, 4 isolates of HBV/B(3) restricted to Indonesia, 32 isolates of HBV/B(4) restricted to Vietnam, and 7 isolates of HBV/B(5) restricted to Philippines. HBV/B(2)-B(5) isolates carried a recombination with HBV/C over the precore and core genes. In addition to the characteristics of HBV/B(1)-B(5) at some cis-acting elements, the precore stop-codon mutant (G1896A) was significantly different among HBV/B(1), HBV/B(2), and HBV/B(4) (70.3%, 31.7%, 53.0%, P=0.001), while no such mutation was found in HBV/B(3) and B(5). Among characteristics of the HBV/B(1)-B(5) amino acid sequences, serotype adw (K(122)) was exclusive among HBV/B(1), HBV/B(2), and HB V/B(3) isolates, while serotype ayw (R(122)) was among the HBV/B(4) and HBV/B(5) isolates. Furthermore, distinct variations of T cell and B cell recognition epitopes within surface and core proteins were also found among these subgenotypes. In conclusion, subgenotypes HBV/B(1)-B(5) exhibited distinct geographical distributions, virologic characteristics, and probable clinical implications.

Five subgenotypes of hepatitis B virus genotype B with distinct geographic and virological characteristics

Several hepatitis B virus (HBV) subgenotypes, HBV/A1, A2, Bj and Ba, have been reported with respect to clinical differences among patients infected with these subgenotypes. The population genetics and phylogeography of HBV were investigated based on the complete genome sequences of 484 isolates with 108 from our chronic hepatitis B patients and the remaining from the GenBank database. Besides genotypes A-H (HBV/A-H), five subgenotypes were identified among 169 HBV/B isolates by phylogenetic analysis and nucleotide divergence. There were 27 isolates of subgenotype B(1) (HBV/B(1)) restricted to Japan, 104 isolates of HBV/B(2) with the widest distribution in most Asian countries, 4 isolates of HBV/B(3) restricted to Indonesia, 32 isolates of HBV/B(4) restricted to Vietnam, and 7 isolates of HBV/B(5) restricted to Philippines. HBV/B(2)-B(5) isolates carried a recombination with HBV/C over the precore and core genes. In addition to the characteristics of HBV/B(1)-B(5) at some cis-acting elements, the precore stop-codon mutant (G1896A) was significantly different among HBV/B(1), HBV/B(2), and HBV/B(4) (70.3%, 31.7%, 53.0%, P=0.001), while no such mutation was found in HBV/B(3) and B(5). Among characteristics of the HBV/B(1)-B(5) amino acid sequences, serotype adw (K(122)) was exclusive among HBV/B(1), HBV/B(2), and HB V/B(3) isolates, while serotype ayw (R(122)) was among the HBV/B(4) and HBV/B(5) isolates. Furthermore, distinct variations of T cell and B cell recognition epitopes within surface and core proteins were also found among these subgenotypes. In conclusion, subgenotypes HBV/B(1)-B(5) exhibited distinct geographical distributions, virologic characteristics, and probable clinical implications.

Chronic celecoxib users more often show regression of gastric intestinal metaplasia after Helicobacter pylori eradication

BACKGROUND AND AIM

To test whether the chronic users of celecoxib, a selective cyclo-oxygenase-2 inhibitor, had less Helicobacter pylori-related intestinal metaplasia or if such users' intestinal metaplasia could be prone to disappear after H. pylori eradication.

METHODS

The study enrolled 150 chronic celecoxib users and 216 non-users who underwent pan-endoscopy to detect H. pylori infection and its related intestinal metaplasia. One hundred and three H. pylori-infected patients with intestinal metaplasia (43 chronic celecoxib users and 60 non-users) received anti-H. pylori therapy and completed the 12-month follow-up to survey the regression of intestinal metaplasia by mean intestinal metaplasia score.

RESULTS

There were no differences in the prevalence of H. pylori-related intestinal metaplasia between the chronic celecoxib users and controls (P > 0.05). On the 12th month of follow-up, chronic celecoxib users had a lower mean intestinal metaplasia score (1.2 vs. 1.8, P < 0.005) and a higher regression rate of intestinal metaplasia (42% vs. 20%, P = 0.027) than non-users.

CONCLUSIONS

With H. pylori infection, chronic celecoxib users still showed limited effects to decrease intestinal metaplasia. Nevertheless, celecoxib should be promising to assist H. pylori eradication for the control of gastric intestinal metaplasia and cancer risk.

Phylogeography of Asian wild rice, Oryza rufipogon, reveals multiple independent domestications of cultivated rice, Oryza sativa

Cultivated rice, Oryza sativa L., represents the world's most important staple food crop, feeding more than half of the human population. Despite this essential role in world agriculture, the history of cultivated rice's domestication from its wild ancestor, Oryza rufipogon, remains unclear. In this study, DNA sequence variation in three gene regions is examined in a phylogeographic approach to investigate the domestication of cultivated rice. Results indicate that India and Indochina may represent the ancestral center of diversity for O. rufipogon. Additionally, the data suggest that cultivated rice was domesticated at least twice from different O. rufipogon populations and that the products of these two independent domestication events are the two major rice varieties, Oryza sativa indica and Oryza sativa japonica. Based on this geographical analysis, O. sativa indica was domesticated within a region south of the Himalaya mountain range, likely eastern India, Myanmar, and Thailand, whereas O. sativa japonica was domesticated from wild rice in southern China.

Incidental primary hyperparathyroidism in a hypercalcaemic woman with tuberculous peritonitis

We report on a 51-year-old woman with initial hypercalcaemia and unknown ascites. In spite of unyielding laparoscopy, laparotomy showed findings compatible with tuberculous peritonitis (TBP). Unexpectedly, a series of examinations eventually revealed the concurrence of hyperparathyroidism due to a parathyroid adenoma. Anti-tuberculous regimen was given and was uneventful. However, hypercalcaemia was not decreased but sustained at a high level even after anti-tuberculous therapy for 3 months. Parathyroidectomy was performed with subsequent normalisation of hypercalcaemia. The aetiology of hypercalcaemia in a patient with an explored disease able to cause this electrolyte abnormality such as TBP may be a coexistent occult parathyroid adenoma.

Hypercalcaemia and haemophagocytic syndrome: rare concurrent presentations of disseminated tuberculosis in a dialysis patient

Tuberculosis remains an important cause of infection in chronic haemodialysis patients. Frequent extrapulmonary involvement, non-specific presentation and limited diagnostic tools usually make early diagnosis difficult. Herein, we report on an 83-year-old female patient who had been on regular heamodialysis therapy for 15 years, who presented with asymptomatic hypercalcaemia and pancytopenia. Haemophagocytic syndrome was documented during the admission period. Mycobacterium tuberculosis was cultured from bone marrow 1 month after her demise. This case report highlights the non-specific manifestations of extrapulmonary tuberculosis in dialysis patients and the limited value of conventional diagnostic methods. We would like to recommend aggressive intervention and early tissue aspiration from possible infectious sites when tuberculosis cannot be completely ruled out. Disseminated tuberculosis should be considered as an indication of hypercalcaemia where haemophagocytic syndrome occurs simultaneously.

Tuberculous peritonitis in uremic patients

AIMS

To identify clinical features and treatment response of tuberculous peritonitis (TBP) in a uremic population, a retrospective case-control study was performed.

MATERIALS AND METHODS

Thirteen uremic patients with TBP (Group I: 62.7 +/- 6.8 years, male 54%) collected between January 1986 and January 2002 were compared with another two age- and sex-matched controls: 19 non-azotemic patients with TBP (Group II: 62.9 +/- 7.3 years, male 47%) and 30 uremic patients without TBP (Group III: 61.1 +/- 8.7 years, male 47%). Clinical information and data of ascites and blood examinations were evaluated.

RESULTS

Significant differences between Groups I and II were found in comorbidity, hypertension, anorexia, percentages of neutrophil and lymphocyte from blood and ascites, and serum calcium (sCa), phosphorus and albumin-adjusted calcium (sAACa). However, no significant differences in duration of symptoms, coexistent pulmonary tuberculosis (p = 0.061), duration or complications of therapy and mortality (p = 0.13) were detected. Significant differences between Groups I and III were found in peripheral white cell counts and percentages of neutrophil and lymphocyte as well as in serum creatinine (sCr), albumin, sCa, sAACa and intact parathyroid hormone (iPTH).

CONCLUSIONS

Non-specific symptoms make the diagnosis of TBP in a uremic population difficult. However, neutrophil predominance in blood and ascites, hypoalbuminemia, relatively lower sCr and hypercalcemia with suppressed serum iPTH were found to be characteristic. In TBP uremic patients, therapy complications were not common and there was a tendency for higher mortality, largely due to septic shock.

Implications of sonographic identification of duplex kidney in adults

BACKGROUND

Duplication of the renal pelvis and ureter constitutes the most common anomalies of the upper urinary tract. Most patients are asymptomatic and don't need treatment. However, the associated anomaly and acquired renal disease may cause morbidity and mortality. The aim of this study was to investigate the prevalence of duplex kidney in sonographic examinations and the predictive capability of this method. An analysis of patients with urography-confirmed duplication anomaly was also performed.

METHODS

During a period of 9 year (from 1988 to 1996), sonographic examination records of 19,287 patients were reviewed. Patients with a diagnosis of duplex kidney were enrolled. Their clinical characteristics and radiological images were recorded and evaluated.

RESULTS

One hundred and sixty-three patients were found by sonography to have duplex kidney, for an prevalence of 0.85%. Urography studies were done on 64 (39.2%) patients, and 42 patients were proven to have duplex kidney. The positive predictive rate of sonography was 65.6%. Eighty percent of patients with duplex kidney had associated ureteral duplication. No associated anomalies were found. Four patients had urolithiasis, and 3 patients had recurrent urinary tract infection. One patient had coexisting uroepithelial malignancy, and 1 patient had refractory gross hematuria.

CONCLUSIONS

Duplex kidney is an uncommon finding during adult sonographic examinations. The sensitivity and specificity of sonography in identifying this anomaly are controversial. An experienced hand with good knowledge of the anomaly and its sonographic signs is helpful in more accurately diagnosing this anomaly.

Neglected bilateral femoral neck fractures in a patient with end-stage renal disease before chronic dialysis

Bilateral femoral neck fractures are rarely reported in patients with end-stage renal disease before chronic dialysis. We report on a 39-year-old woman with neglected bilateral femoral neck fractures, who presented with severe uremic complications prior to chronic dialysis. Three years before admission, she had injured herself in a trivial slip with subsequent bilateral hip pain. She had progressively waddled since then. Pelvic X-ray taken after admission revealed bilateral femoral neck fractures. Bilateral hip hemiarthroplasties were subsequently performed. Displaced femoral neck fractures were found intraoperatively. Pathologic findings and results of examinations supported the coexistence of osteoporosis and high turnover renal osteodystrophy, rendering this woman at high risk of bilateral femoral neck fractures. Therefore, preventing a simple fall or trivial accident and treating renal osteodystrophy and osteoporosis are paramount in patients with chronic renal failure even before the start of dialysis therapy. We also emphasize the need to seek any possible underlying metabolic bone disease once a patient presents with unusual fractures.

Successful pregnancy by transmyometrial and transtubal embryo transfer after IVF in a patient with congenital cervical atresia who underwent uterovaginal canalization during Caesarean section: case report

Successful pregnancy in a patient with congenital cervical atresia is a great challenge for assisted reproductive techniques and reproductive medicine. We report a case of successful pregnancy by transmyometrial and transtubal embryo transfer simultaneously after in-vitro fertilization (IVF) in a 33 year-old patient with congenital cervical atresia diagnosed at the age of 18 years. The patient had experienced cyclic abdominal pain and amenorrhoea since she was 13 years old. She had had two unsuccessful attempts to create a new uterovaginal canal in another hospital. At the age of 32 years, she was referred to our unit and had a successful pregnancy after transmyometrial and transtubal embryo transfer. Caesarean section was performed at 36 weeks gestation due to progressive pre-eclampsia and gestational diabetes. A healthy male baby weighing 2812 g was safely delivered. Uterovaginal canalization with amniotic membrane for the covering of the neo-endocervical wall was performed during Caesarean section. Normal menstrual outflow and symptomatic relief have continued for 5 months after the operation. To the best of our knowledge, this is the first reported case of successful pregnancy by transmyometrial and transtubal embryo transfer as well as uterovaginal canalization performed during Caesarean section in a patient with congenital cervical atresia.

Ischemic bowel disease in chronic dialysis patients

BACKGROUND

Ischemic bowel disease, especially acute mesenteric ischemia, carries high morbidity and mortality rates. Any delay in diagnosis or treatment aggravates the patient's outcome. Owing to the scarcity of reports concerning ischemic bowel disease in chronic dialysis patients, we investigated the ischemic bowel disease in chronic dialysis patients.

METHODS

From January 1986 through April 1997, medical records of 2416 chronic dialysis patients at our hospital were reviewed. Among them, 5 patients with surgically documented ischemic bowel disease were enrolled. The clinical manifestations, laboratory findings, operative findings, pathologic test results and prognoses of these patients are reported.

RESULTS

Abdominal pain, abdominal distension and bloody stool were major initial presentations. The mean age of the patients was 62.4 years at the time of diagnosis of ischemia. All patients had hypertension, 3 patients had hyperlipidemia, three patients had diabetes mellitus and three patients had history of shunt occlusion. Four patients had leukocytosis. Image studies revealed dilatation of bowel loops in four patients. Peritonitis made exploratory laparotomy necessary. The findings during operation showed turbid ascites and variable degrees of bowel ischemia or gangrene. The methods of surgical intervention depended on the severity of the disease. Only one patient died due to extensive ischemic bowel involvement and subsequent sepsis.

CONCLUSION

It is mandatory to have an index suggestive of ischemic bowel disease in chronic dialysis patients with unexplained abdominal pain or discomfort. Early diagnosis and aggressive surgical intervention is the cure modality for patients with acute ischemic bowel disease.

Intracranial acute arterial ischemia of the anterior circulation: evaluation with three-dimensional time-of-flight magnetic resonance angiography

BACKGROUND

Stroke has been the second most common cause of death, after cancer, in Taiwan since 1983. The cost of stroke to society in terms of morbidity, mortality and economics is profound. Heightened interest in the early diagnosis and treatment of acute stroke challenges neuroimagers to optimize available modalities and to develop new techniques for the evaluation of cerebrovascular disease. The aim of this study was to investigate the effectiveness of magnetic resonance angiography (MRA) in conjunction with spin-echo imaging in patients with acute brain infarction of the anterior circulation.

METHODS

Magnetic resonance imaging and three-dimensional Fourier transformed time-of-flight MRA studies, performed on 50 patients within one week after the onset of cerebral ischemia, were retrospectively reviewed and correlated with clinical records. Five of the 50 MRAs were considered nondiagnostic and excluded because of poor patient cooperation.

RESULTS

In 41 of the 45 cases, the area of infarct corresponding to the clinical deficit at the time of study was identified on T2-weighted spin-echo images. Arterial occlusions or severe stenoses that corresponded to ischemic manifestations were identified with MRA in 37 of the 45 patients. A focal discontinuity with decreased arterial caliber corresponded to stenosis and nonvisualization of distal branches represented arterial occlusion. MRA provided information for 23 cases not obtained from the MR images.

CONCLUSIONS

Vascular lesions demonstrated on intracranial MRA show a high correlation with infarct distribution. MRA, which provides information adjunctive to conventional MR imaging in a majority of cases, is concluded to be an important component of the complete evaluation of brain infarction.

Traumatic dissection of the vertebral artery: a case report

This report concerns a patient suffering from a severe neck pain on the third day after a traffic accident. This condition was followed by a lateral medullary infarction on the next day. One week later, he was transferred to this hospital and dissection of the vertebral artery was disclosed. It should be emphasized that in case of acute cervical spine injury or severe neck pain after a major trauma, vertebral artery dissection should be considered, as its early diagnosis may have crucial therapeutic implications. In addition, the advantages of the combination of magnetic resonance imaging and magnetic resonance angiography as diagnostic tools-of-choice are emphasized.