Comparison of inorganic nitrogen concentrations in airborne particles at inshore and offshore sites in the Yellow Sea (2017-2019): Long-range transport and potential impact on marine productivity

Atmospheric deposition of nitrogen is one of the most important external nutrient sources. We investigated the concentrations of NO3- and NH4+ in airborne particles at both an offshore and an inshore site in the Yellow Sea. At the offshore site, devoid of local sources and located downwind from the highly developed areas of Korea and China, the concentrations of atmospheric particulate NO3- and NH4+ were ∼88 ± 101 nmol m-3 and ∼102 ± 102 nmol m-3, respectively, likely due to the transboundary long-range transport of pollutants. The inshore site showed a concentration ∼2 times higher than the offshore site. Considering not only dry inorganic nitrogen deposition but also wet and organic material deposition, the total atmospheric nitrogen deposition was estimated to contribute roughly 10 % to the new production in the Yellow Sea.

Impact of vertical stratification on the 2020 spring bloom in the Yellow Sea

The Yellow Sea is one of the world's most abundant marine resources, providing food and economic benefits to the Korean and Chinese populations. In spring 2020, a decrease in the intensity of phytoplankton bloom was observed. While one study attributed this decline to a decrease in nutrient associated with the COVID-19 pandemic, our previous research proposed weakened thermal stratification accompanied by a surface cooling anomaly as the cause. However, the relationship between the marine environment and ecosystem has not been fully elucidated. Using observations and marine physical-biogeochemical model data, we identified the weakened stratification as a critical factor for suppressing the 2020 spring bloom. Intense vertical mixing hindered the accumulation of nutrient and chlorophyll-a concentrations within the euphotic zone, resulting in a diminished phytoplankton bloom. In contrast, reduced nitrate and phosphate concentrations in 2020 were insignificant compared to those in 2017-2019, despite the notable decline in PM2.5 in March 2020 due to COVID-19. In April 2020, nutrient levels fell within the range of interannual variability based on long-term observations, reflecting a negligible effect on the spring phytoplankton bloom. Our findings provide insight into the importance of marine physical factors on the phytoplankton biomass in the Yellow Sea.

Shimiella gen. nov. and Shimiella gracilenta sp. nov. (Dinophyceae, Kareniaceae), a Kleptoplastidic Dinoflagellate from Korean Waters and its Survival under Starvation

A small dinoflagellate, ~13 μm in cell length, was isolated from Jinhae Bay, Korea. Light microscopy showed that it was similar to the kleptoplastidic dinoflagellate Gymnodinium gracilentum nom. inval. rDNA sequences were obtained and its anatomy and morphology described using light and scanning and transmission electron microscopy. Phylogenetic analyses indicated that it belonged to the family Kareniaceae. However, its large subunit (LSU) rDNA sequences were 5.2-9.5% different from those of the other five genera in the family, and its clade was clearly divergent from that of each genus. Its overall morphology was different from those of the other five genera in the family and from Gymnodinium. Unlike Gymnodinium, this dinoflagellate did not have a horseshoe-shaped apical groove, nuclear envelope chambers, or a nuclear fibrous connective (NFC). It had an apical line of narrow amphiesmal vesicles and an elongated apical furrow crossing the apex. Cells were covered with polygonal amphiesmal vesicles arranged in 16 rows. Starved cells did not contain their own plastids, eyespots, pyrenoids, peridinin, or fucoxanthin. However, they could survive without added prey for approximately one month using chloroplasts from the cryptophyte prey Teleaulax amphioxeia, indicating kleptoplastidy. Because this taxon is genetically distinct at the generic rank from the other genera in Kareniaceae, it is placed in Shimiella gen. nov., and because G. gracilentum was invalid, the new bionomial S. gracilenta sp. nov. is proposed.

Evolutionary Mechanisms of Long-Term Genome Diversification Associated With Niche Partitioning in Marine Picocyanobacteria

Marine picocyanobacteria of the genera Prochlorococcus and Synechococcus are the most abundant photosynthetic organisms on Earth, an ecological success thought to be linked to the differential partitioning of distinct ecotypes into specific ecological niches. However, the underlying processes that governed the diversification of these microorganisms and the appearance of niche-related phenotypic traits are just starting to be elucidated. Here, by comparing 81 genomes, including 34 new Synechococcus, we explored the evolutionary processes that shaped the genomic diversity of picocyanobacteria. Time-calibration of a core-protein tree showed that gene gain/loss occurred at an unexpectedly low rate between the different lineages, with for instance 5.6 genes gained per million years (My) for the major Synechococcus lineage (sub-cluster 5.1), among which only 0.71/My have been fixed in the long term. Gene content comparisons revealed a number of candidates involved in nutrient adaptation, a large proportion of which are located in genomic islands shared between either closely or more distantly related strains, as identified using an original network construction approach. Interestingly, strains representative of the different ecotypes co-occurring in phosphorus-depleted waters (Synechococcus clades III, WPC1, and sub-cluster 5.3) were shown to display different adaptation strategies to this limitation. In contrast, we found few genes potentially involved in adaptation to temperature when comparing cold and warm thermotypes. Indeed, comparison of core protein sequences highlighted variants specific to cold thermotypes, notably involved in carotenoid biosynthesis and the oxidative stress response, revealing that long-term adaptation to thermal niches relies on amino acid substitutions rather than on gene content variation. Altogether, this study not only deciphers the respective roles of gene gains/losses and sequence variation but also uncovers numerous gene candidates likely involved in niche partitioning of two key members of the marine phytoplankton.

Clinical characteristics of diabetic ketoacidosis in users and non-users of SGLT2 inhibitors

AIM

This study investigated the clinical characteristics of diabetic ketoacidosis (DKA) and compared the DKA characteristics between patients treated with and without SGLT2 inhibitors.

METHODS

Data were collected from patients aged ≥ 18 years admitted for DKA at nine centres in Korea between September 2014 and April 2017. The electronic medical records of these subjects were retrospectively reviewed. Based on their history of medications taken before admission, subjects were classified as either users or non-users of SGLT2 inhibitors and their clinical characteristics of DKA were compared.

RESULTS

During the study, the main subtype of DKA episodes (n = 523) was identified as type 2 diabetes (51%). Average hospitalization duration was 11 days, and average intensive care unit (ICU) time was 2.5 days. The in-hospital mortality rate was 3%, but no users of SGLT2 inhibitors died during DKA treatment. In patients taking SGLT2 inhibitors (n = 15), DKA manifested at 124 days, on average, after starting the inhibitors (range: 7-380 days). Also, SGLT2 inhibitors users had significantly lower plasma glucose levels (413 mg/dL) compared with non-users (554 mg/dL), and longer ICU stays (4 vs. 2 days; P = 0.019).

CONCLUSION

In this report of recent data on the clinical features of DKA in Korea, patients using SGLT2 inhibitors needed longer treatment in ICUs compared with non-users and had lower levels of blood glucose, whereas DKA associated with SGLT2 inhibitors was rare.

Landscape of Elderly Suicide in South Korea: Its Trend According to Age, Gender, and Educational Attainment

South Korea has one of the highest suicide rates in the world, and the most alarming suicide rate is among its elders. This study aims to understand the social, historical, and cultural context of the Korean older adults and examine suicide trends based on that understanding. The results show that the suicide risk increases with age, the male suicide rate outweighs that of females, and the suicide rate decreases with educational attainment. In addition, several suggestions for reducing elderly suicide rate are addressed, including differentiating the existing social services for elders by age and expanding suicide prevention programs beyond schools to communities so that all people in need can access them.

Daily variation in the prokaryotic community during a spring bloom in shelf waters of the East China Sea

To understand prokaryotic responses during a spring bloom in offshore shelf waters, prokaryotic parameters were measured daily at a station located in the middle of the East China Sea over a six-week period from March 25 to May 19. The site experienced a phytoplankton bloom in late April, triggering changes in prokaryotic abundance and production after a lag of approximately one week. Before the bloom, changes in prokaryotic composition were small. Both during the bloom and in the post-bloom period, successive changes among bacterial groups were apparent. A SAR11 group became more dominant during the bloom period, and diverse groups belonging to the Flavobacteriia occurred dominantly during both the bloom and post-bloom periods. However, bacterial community changes at the species level during the bloom and post-bloom periods occurred rapidly in a time scale of a few days. Especially, NS5, NS4 and Formosa bacteria belonging to Flavobacteriia and bacteria belonging to Halieaceae and Arenicellaceae families of Gammaproteobacteria showed a successive pattern with large short-term variation during the period. The changes in prokaryotic composition were found to be related to phytoplankton biomass and composition, as well as seawater temperature and variations in nutrients.

Remote quantification of Cochlodinium polykrikoides blooms occurring in the East Sea using geostationary ocean color imager (GOCI)

Accurate and timely quantification of widespread harmful algal bloom (HAB) distribution is crucial to respond to the natural disaster, minimize the damage, and assess the environmental impact of the event. Although various remote sensing-based quantification approaches have been proposed for HAB since the advent of the ocean color satellite sensor, there have been no algorithms that were validated with in-situ quantitative measurements for the red tide occurring in the Korean seas. Furthermore, since the geostationary ocean color imager (GOCI) became available in June 2010, an algorithm that exploits its unprecedented observation frequency (every hour during the daytime) has been highly demanded to better track the changes in spatial distribution of red tide. This study developed a novel red tide quantification algorithm for GOCI that can estimate hourly chlorophyll-a (Chl a) concentration of Cochlodinium (Margalefidinium) polykrikoides, one of the major red tide species around Korean seas. The developed algorithm has been validated using in-situ Chl a measurements collected from a cruise campaign conducted in August 2013, when a massive C. polykrikoides bloom devastated Korean coasts. The proposed algorithm produced a high correlation (R²=0.92) with in-situ Chl a measurements with robust performance also for high Chl a concentration (300mg/m³) in East Sea areas that typically have a relatively low total suspended particle concentration (<0.5mg/m³).

Variation of Synechococcus Pigment Genetic Diversity Along Two Turbidity Gradients in the China Seas

Synechococcus are important and widely distributed picocyanobacteria that encompass a high pigment diversity. In this study, we developed a primer set (peBF/peAR) for amplifying the cpeBA operon sequence from Synechococcus genomic DNA to study Synechococcus pigment diversity along two turbidity gradients in the China seas. Our data revealed that all previously reported pigment types occurred in the South (SCS) and East (ECS) China Seas. In addition, a novel pigment genetic type (type 3f), represented by the high phycourobilin Synechococcus sp. strain KORDI-100 (Exc495:545 = 2.35), was detected. This pigment genetic type differs from the 3c/3d types not only for a very high PUB/PEB ratio but also for a different intergenic spacer sequence and gene organization of the phycobilisome. Synechococcus of different pigment types exhibited clear niche differentiation. Type 2 dominated in the coastal waters, whereas type 3c/3d and 3f were predominant in oceanic waters of the SCS in summer. In the ECS, however, type 3a was the major pigment type throughout the transect. We suggest that in marine environment, various pigment types often co-occur but with one type dominant and PUB/PEB ratio is related to geographic distribution of Synechococcus pigment types. The two marginal seas of China have markedly different Synechococcus pigment compositions.

Comparative study on the effectiveness of a corticosteroid injection for carpal tunnel syndrome in patients with and without Raynaud's phenomenon

AIMS

The aim of this study was to compare the efficacy of a corticosteroid injection for the treatment of carpal tunnel syndrome (CTS) in patients with and without Raynaud's phenomenon.

PATIENTS AND METHODS

In a prospective study, 139 patients with CTS were treated with a corticosteroid injection (10 mg triamcinolone acetonide); 34 had Raynaud's phenomenon and 105 did not (control group). Grip strength, perception of touch with a Semmes-Weinstein monofilament and the Boston Carpal Tunnel Questionnaires (BCTQ) were assessed at baseline and at six, 12 and 24 weeks after the injection. The Cold Intolerance Severity Score (CISS) questionnaire was also assessed at baseline and 24 weeks after the injection.

RESULTS

The two groups had similar baseline BCTQ scores, but the scores in the Raynaud's phenomenon group were significantly higher than those in the control group at 12 and 24 weeks after the injection. Throughout the 24-week follow-up, there were no significant differences in the mean grip strength between the groups, whereas the mean Semmes-Weinstein monofilament sensory index for the control group was significantly higher than that of the Raynaud's phenomenon group. The mean CISSs were not significantly different between the groups at baseline and at 24 weeks. After 24 weeks, 11 patients (32%) in the Raynaud's phenomenon group and 16 (15%) in the control group required carpal tunnel decompression (p = 0.028). Multivariable analysis indicated that concurrent Raynaud's phenomenon (odds ratio (OR) 2.6) and severe electrophysiological grade (OR 2.1) were independently associated with a failure of treatment after a corticosteroid injection.

CONCLUSION

Although considerable improvements in symptoms will probably occur in patients with Raynaud's phenomenon who have CTS, they have higher risk of poor functional outcomes and failure of treatment than those without Raynaud's phenomenon. Cite this article: Bone Joint J 2017;99-B:1637-42.

Identification of benthic diatoms isolated from the eastern tidal flats of the Yellow Sea: Comparison between morphological and molecular approaches

Benthic diatoms isolated from tidal flats in the west coast of Korea were identified through both traditional morphological method and molecular phylogenetic method for methodological comparison. For the molecular phylogenetic analyses, we sequenced the 18S rRNA and the ribulose bisphosphate carboxylase large subunit coding gene, rbcL. Further, the comparative analysis allowed for the assessment of the suitability as a genetic marker for identification of closely related benthic diatom species and as potential barcode gene. Based on the traditional morphological identification system, the 61 isolated strains were classified into 52 previously known taxa from 13 genera. However, 17 strains could not be classified as known species by morphological analyses, suggesting a hidden diversity of benthic diatoms. The Blast search on NCBI's Genebank indicated that the reference sequences for most of the species were absent for the benthic diatoms. Of the two genetic markers, the rbcL genes were more divergent than the 18S rRNA genes. Furthermore, a long branch attraction artefact was found in the 18S rRNA phylogeny. These results suggest that the rbcL gene is a more appropriate genetic marker for identification and classification of benthic diatoms. Considering their high diversity and simple shapes, and thus the difficulty associated with morphological classification of benthic diatoms, a molecular approach could provide a relatively easy and reliable classification system. However, this study suggests that more effort should be made to construct a reliable database containing polyphasic taxonomic data for diatom classification.

Effects of metabolic syndrome on the functional outcomes of corticosteroid injection for De Quervain tenosynovitis

Metabolic syndrome is a constellation of medical conditions that arise from insulin resistance and abnormal adipose deposition and function. In patients with metabolic syndrome and De Quervain tenosynovitis this might affect the outcome of treatment by local corticosteroid injection. A total of 64 consecutive patients with De Quervain tenosynovitis and metabolic syndrome treated with corticosteroid injection were age- and sex-matched with 64 control patients without metabolic syndrome. The response to treatment, including visual analogue scale score for pain, objective findings consistent with De Quervain tenosynovitis (tenderness at first dorsal compartment, Finkelstein test result), and Disability of the Arm, Shoulder, and Hand score were assessed at 6, 12, and 24 weeks follow-up. Treatment failure was defined as persistence of symptoms or surgical intervention. Prior to treatment, patients with metabolic syndrome had mean initial pain visual analogue scale and Disability of the Arm, Shoulder, and Hand scores similar to those in the control group. The proportion of treatment failure in the metabolic syndrome group (43%) was significantly higher than that in the control group (20%) at 6 months follow-up. The pain visual analogue scale scores in the metabolic syndrome group were higher than the scores in the control group at the 12- and 24-week follow-ups. The Disability of the Arm, Shoulder, and Hand scores of the metabolic syndrome group were higher (more severe symptoms) than those of the control group at the 12- and 24-week follow-ups. Although considerable improvements in symptom severity and hand function will likely occur in patients with metabolic syndrome, corticosteroid injection for De Quervain tenosynovitis is not as effective in these patients compared with age- and sex-matched controls in terms of functional outcomes and treatment failure.

LEVEL OF EVIDENCE

III.

Effect of metabolic syndrome on the outcome of corticosteroid injection for carpal tunnel syndrome

Diffuse peripheral nerve impairment is common in metabolic syndrome: in patients with metabolic syndrome and carpal tunnel syndrome this might affect the outcome of treatment by local corticosteroid injection. A total of 55 consecutive patients with carpal tunnel syndrome and metabolic syndrome treated with corticosteroid injection (10 mg triamcinolone acetonide) were age and sex matched with 55 control patients without metabolic syndrome. Grip strength, perception of touch with Semmes-Weinstein monofilaments and Boston Carpal Tunnel Questionnaires were assessed at the baseline and at 6, 12 and 24 weeks follow-up. The two groups had similar pre-operative grip strength and Boston Carpal Tunnel Questionnaire scores. The Boston Carpal Tunnel Questionnaire symptom and function scores of the metabolic syndrome group were significantly greater than the control group at 12 and 24 weeks follow-up. Except for significantly greater grip strength at the 12-week follow-up in the control group, there were no significant differences in grip strength between the groups. Semmes-Weinstein monofilament sensory index for the control group was significantly greater than that of the metabolic syndrome group throughout the 24-week follow-up. After 24 weeks, five patients (13%) in the control group and 13 patients (27%) in the metabolic syndrome group had had carpal tunnel surgery. Patients with metabolic syndrome are at risk for poor functional outcome and failure of treatment after corticosteroid injection for carpal tunnel syndrome.

LEVEL OF EVIDENCE

Treatment benefits III.

Supplementary tibial fixation in anterior cruciate ligament reconstruction - Direct cortical fixation using spiked washer screw vs. post-tie using washer screw

We compare clinical outcomes of two different supplementary tibial fixation in anterior cruciate ligament (ACL) reconstruction using free tendon Achilles allograft. Eighty subjects underwent ACL reconstruction using Endobutton CL for femoral fixation and Bio-interference screw for tibial fixation. Supplementary tibial fixation was performed as direct -cortical fixation using spiked washer screw (group I) or as post-tie using washer screw (group II). -Lachman test, pivot shift test, IKDC classification, Lysholm score, and side-to-side difference (SSD) were evaluated. Thirty six in group I and thirty five in group II could follow up for at least 2 years. At the last follow-up, 7 in group I and 1 in group II showed 2+ or 3+ in Lachman test (p = 0.027). Mean SSD was 2.4mm in group I and 1.4mm in group II (p = 0.048). Post-tie using washer screw was more effective than direct cortical fixation using spiked washer screw to restore stability. Level of evidence : Therapeutic Level I ; Randomized controlled clinical trial.

Complete mitochondrial genome of biraphid benthic diatom, Navicula ramosissima (Naviculales, Bacillariophyceae)

The complete mitochondrial DNA of biraphid benthic diatom, Navicula ramosissima TA439 was sequenced and characterized. The circular mitogenome contains 67 genes in 48,652 bp (31.1% GC), including 41 protein-coding, 24 transfer RNA (tRNA) and 2 rRNA genes. Twenty-four protein-coding sequences (CDS, 59%) have start with ATG codon and 17 CDS start with alternatives such as ATA (5), ATT (6), TTA (5) and TTG (1). The GC content of tRNA genes (42.1%) is relatively higher than those of the rRNA (35.2%) and CDS (30.5%). Three genes are consisted of multiple exons and introns, i.e. cox1 (three exons, two introns), rps11 (two exons, one intron), rrl (four exons, three introns). Phylogeny of diatoms based on mitogenome data (34 CDS, 8530 amino acids combined) supports the monophyly of Naviculales, including N. ramosissima (Naviculaceae), Berkeleya fennica (Berkeleyaceae), Fistulifera solaris (Stauroneidaceae) and Phaeodactylum tricornutum (Phaeodactylaceae). Mitogenome data may be useful for phylogenetic study of the diatoms and stramenopiles.

Association of heart rate with albuminuria in a general adult population: the 2011 Korea National Health and Nutrition Examination Survey

BACKGROUND

Albuminuria is associated with increased risk of multiple adverse health outcomes, such as progressive renal failure, cardiovascular disease and death. However, in the general population, it is uncertain whether albuminuria is associated with elevated heart rate, which is an independent and powerful risk factor for cardiovascular disease.

AIM

To investigate whether an elevated heart rate is an independent factor associated with albuminuria in the general adult population of Korea.

METHODS

A cross-sectional analysis was carried out on 5198 Korean adults aged 19 years or older who participated in the fifth (2011) Korea National Health and Nutrition Examination Survey (KNHANES V-2).

RESULTS

The prevalence of albuminuria showed an increasing trend throughout the whole range of heart rate, even after adjusting for confounders (P = 0.002). The increment was most profound at the heart rate of 70-75 and >76 beats per minute (b.p.m.; P = 0.011). In multiple logistic regression analysis, age (P < 0.001), hypertension (P < 0.001), diabetes (P < 0.001), hypertriglyceridaemia (P = 0.025), estimated glomerular filtration rate (P = 0.028) and heart rate (P = 0.023) were independently associated with the presence of albuminuria in Korean adults. Compared with participants with heart rate ≤ 64 b.p.m., the odds ratio (95% CI) for albuminuria was 1.50 (1.15-1.96) for those with heart rate ≥ 76 b.p.m.

CONCLUSIONS

The prevalence of albuminuria is independently associated with heart rate in the general adult population of Korea.

Complete mitochondrial genome of Skeletonema marinoi (Mediophyceae, Bacillariophyta), a clonal chain forming diatom in the west coast of Korea

The complete mitochondrial DNA of common planktonic diatom, Skeletonema marinoi JK029 was sequenced and characterized. The circular mitogenome contains 62 genes in 38 515 bp (29.7% GC), including 35 protein-coding, 2 rRNA, and 25 tRNA genes. Total 80% of protein-coding genes have usual ATG start codon and 20% have alternative start codons. The GC content of tRNA genes (39.8%) is relatively higher than those of the rRNA (32.9%) and CDS (29.3%). There are four cases of gene overlapping between neighboring genes, i.e., rrs-trnM, rps2-rps4, nad1-tatC, and rps11-trnY. Newly determined mitogenome of S. marinoi was compared with available seven diatoms and eight stramenopiles by using the maximum-likelihood analysis. The 34-CDS concatenated data (8528 amino acids) support the monophyly of Bacillariophyta. However, mitogenome data showed different higher class-levels clustering with previous study. These results suggested that additional mitogenome data will provide useful information for mitochondrial genome diversity and evolution of the diatoms and stramenopiles.

Pulsed laser-assisted focused electron-beam-induced etching of titanium with XeF2: enhanced reaction rate and precursor transport

In order to enhance the etch rate of electron-beam-induced etching, we introduce a laser-assisted focused electron-beam-induced etching (LA-FEBIE) process which is a versatile, direct write nanofabrication method that allows nanoscale patterning and editing. The results demonstrate that the titanium electron stimulated etch rate via the XeF2 precursor can be enhanced up to a factor of 6 times with an intermittent pulsed laser assist. The evolution of the etching process is correlated to in situ stage current measurements and scanning electron micrographs as a function of time. The increased etch rate is attributed to photothermally enhanced Ti-F reaction and TiF4 desorption and in some regimes enhanced XeF2 surface diffusion to the reaction zone.

Repeat region absent in mitochondrial genome of tube-dwelling diatom Berkeleya fennica (Naviculales, Bacillariophyceae)

The complete mitochondrial DNA of tube-dwelling diatom, Berkeleya fennica was sequenced and characterized. The circular mitogenome contains 63 genes in 35,509 bp (29.7% GC), including 36 protein-coding, 25 tRNA, 2 rRNA genes. Most of the protein-coding (27) genes have usual ATG start codon, except 9 genes such as ATA for rps8; ATC for rps14; ATT for rps12 and orf51; GTG for nad5; TTA for cox3, nad4 and orf147; and TTG for cob. The nad11 and rrs are the only interrupted genes in the mitogenome. Gene content and synteny of B. fennica are very similar to Phaeodactylum tricoruntum (NC_016739). Absence of repeat region in B. fennica resulted in mitogenome size difference to P. tricoruntum. A new mitogenome will provide useful information for mitochondrial genome diversity and evolution of the diatoms.

Complete mitochondrial genome of Upogebia yokoyai (Decapoda, Crustacea) from Jejudo, Korea

The complete mitochondrial DNA of an ecologically important crustacean mud shrimp, Upogebia yokoyai (Decapoda, Crustacea) was sequenced. We used next generation sequencing strategy for total genomic DNA and organelle genome pipeline for mitogenome assembly. A newly determined mitogenome was 16,063 bp in total length with 28% of GC content. Thirty-seven genes were identified including 13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes. We found ten case of overlapping between neighboring genes. Based on genome comparison, the mitogenome of U. yokoyai shows general crustacean gene content and identical synteny to the sister species, such as U. major and U. pusilla. Our results will provide useful information for mitochondrial genome diversity and evolution of the Crustacea.

Clinical significance of skip lymph node metastasis in gastric cancer patients

PURPOSE

Given the recent increase in the incidence of early gastric cancer, there is greater interest in identifying a minimally invasive therapy. The purpose of this study was to analyze the patterns of lymph node metastasis in patients with gastric cancer and to elucidate the clinical significance of skip metastasis.

METHODS

We retrospectively analyzed patterns of lymph node metastasis (LNM) and clinicopathologic factors related to skip metastasis.

RESULTS

Among 2963 patients with gastric cancer, 997 patients (33.6%) were detected as having LNM, and 27 patients (2.7%) with skip metastasis were detected among 997 patients with LNM. Skip metastasis were detected more frequently in the elderly. Compared with the N1 group, the skip metastasis group showed lower frequency of vascular invasion, and compared with the stepwise N2 group, the skip metastasis group showed smaller tumor size and a significantly higher incidence of negative lymphatic, vascular, and perineural invasion.

CONCLUSIONS

Currently there is no way to predict N2 station LNM including skip metastasis, D2 LN dissection for gastric cancer is thought to be the appropriate treatment, even during early stage disease. Minimally invasive therapy should be performed cautiously in consideration of possible skip metastasis.

Direct linkage between dimethyl sulfide production and microzooplankton grazing, resulting from prey composition change under high partial pressure of carbon dioxide conditions

Oceanic dimethyl sulfide (DMS) is the enzymatic cleavage product of the algal metabolite dimethylsulfoniopropionate (DMSP) and is the most abundant form of sulfur released into the atmosphere. To investigate the effects of two emerging environmental threats (ocean acidification and warming) on marine DMS production, we performed a large-scale perturbation experiment in a coastal environment. At both ambient temperature and ∼ 2 °C warmer, an increase in partial pressure of carbon dioxide (pCO2) in seawater (160-830 ppmv pCO2) favored the growth of large diatoms, which outcompeted other phytoplankton species in a natural phytoplankton assemblage and reduced the growth rate of smaller, DMSP-rich phototrophic dinoflagellates. This decreased the grazing rate of heterotrophic dinoflagellates (ubiquitous micrograzers), resulting in reduced DMS production via grazing activity. Both the magnitude and sign of the effect of pCO2 on possible future oceanic DMS production were strongly linked to pCO2-induced alterations to the phytoplankton community and the cellular DMSP content of the dominant species and its association with micrograzers.

Complete mitochondrial genome of Pacific abalone (Haliotis discus hannai) from Korea

We have sequenced and characterized the complete mitochondrial DNA of an economically and ecologically important Pacific abalone, Haliotis discus hannai (Haliotidae, Gastropoda). The mitogenome of the Pacific abalone is 16,886 nt total length with a 39.6% G+C composition. Thirty-seven genes were identified including 13 protein-coding, 2 rRNA and 22 tRNA genes. We compared the mitogenome of the Pacific abalone to a putative relative species, H. rubra.

Application of pyrosequencing method for investigating the diversity of synechococcus subcluster 5.1 in open ocean

Synechococcus are distributed throughout the world's oceans and are composed of diverse genetic lineages. However, as they are much less abundant than Prochlorococcus in oligotrophic open oceans, their in-depth genetic diversity cannot be investigated using commonly used primers targeting both Prochlorococcus and Synechococcus. Thus, in this study, we designed a primer specific to the 16S-23S rRNA internal transcribed spacer (ITS) of the Synechococcus subcluster 5.1. Using the primer, we could selectively amplify Synechococcus sequences in oligotrophic seawater samples. Further, we showed that a barcoded amplicon pyrosequencing method could be applicable to investigate Synechococcus diversity using sequences retrieved in GenBank and obtained from environmental samples. Allowing sequence analyses of a large number of samples, this high-throughput method would be useful to study global biodiversity and biogeographic patterns of Synechococcus in marine environments.

Draft genome sequence of Rubidibacter lacunae strain KORDI 51-2(T), a cyanobacterium isolated from seawater of Chuuk lagoon

A photoautotrophic cyanobacterium, Rubidibacter lacunae was reported in 2008 for the first time. The type strain, KORDI 51-2^T, was isolated from seawater of Chuuk lagoon located in a tropical area. Although it belonged to a clade exclusively comprised of extremely halotolerant strains by phylogenetic analyses, R. lacunae is known to be incapable of growth at high salt concentration over 10%. Here we report the main features of the genome of R. lacunae strain KORDI 51-2^T. The genome of R. lacunae contains a gene cluster for phosphonate utilization encoding three transporters, one regulator and eight C-P lyase subunits.

Gracilimonas rosea sp. nov., isolated from tropical seawater, and emended description of the genus Gracilimonas

A Gram-staining-negative, non-motile, spore-forming, rod-shaped, marine bacterial strain, CL-KR2(T), was isolated from tropical seawater near Kosrae, an island in the Federated States of Micronesia. Analysis of the 16S rRNA gene sequence of strain CL-KR2(T) revealed a clear affiliation with the genus Gracilimonas. Based on phylogenetic analysis, strain CL-KR2(T) showed the closest phylogenetic relationship to Gracilimonas tropica CL-CB462(T), with 16S rRNA gene sequence similarity of 96.6 %. DNA-DNA relatedness between strain CL-KR2(T) and G. tropica CL-CB462(T) was 6.7 % (reciprocal 9.5 %). Strain CL-KR2(T) grew in the presence of 1-20 % sea salts and the optimal salt concentration was 3.5-5 %. The temperature and pH optima for growth were 35 °C and pH 7.5. The major cellular fatty acids (≥10.0 %) of strain CL-KR2(T) were iso-C15 : 0, summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c) and iso-C17 : 1ω9c and the only isoprenoid quinone was MK-7. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unidentified phospholipid, two unidentified glycolipids and two unidentified lipids. The genomic DNA G+C content of strain CL-KR2(T) was 43.2 mol%. The combined phenotypic, chemotaxonomic and phylogenetic data showed that strain CL-KR2(T) could be distinguished from the only member of the genus Gracilimonas with a validly published name. Thus, strain CL-KR2(T) should be assigned to a novel species in the genus Gracilimonas, for which the name Gracilimonas rosea sp. nov. is proposed. The type strain is CL-KR2(T) ( = KCCM 90206(T) = JCM 18898(T)).

Phylogenetic investigations on ten genera of tintinnid ciliates (Ciliophora: Spirotrichea: Tintinnida), based on small subunit ribosomal RNA gene sequences

Tintinnida is a diverse taxon that accommodates over 1,500 morphospecies, which is an important component of marine planktonic food webs. However, evolutionary relationships of tintinnids are poorly known because molecular data of most groups within this order are lacking. In our study, the small subunit (SSU) rRNA genes representing 10 genera, 5 families of Tintinnida were sequenced, including the first SSU rRNA gene sequences for Coxliella, Dadayiella, Epiplocyloides, and Protorhabdonella, and phylogenetic trees were constructed to assess their intergeneric relationships. Phylogenies inferred from different methods showed that (1) Three newly sequenced Eutintinnus species fell into Eutintinnus clade forming a sister group to the clade containing Amphorides, Steenstrupiella, Amphorellopsis, and Salpingella; (2) Surprisingly, the genetic distances between Amphorides amphora and Amphorellopsis acuta population 1 was even smaller than that between the two populations of Amphorellopsis acuta, casting doubt on the validity of Amphorides and Amphorellopsis as presently defined; (3) The SSU rRNA sequences of Dadayiella ganymedes and Parundella aculeata were almost identical. Therefore, Parundella ganymedes novel combination is proposed; (4) Coxliella, which is currently assigned within Metacylididae, branched instead with some Tintinnopsis species. Furthermore, the validation of Coxliella, which was considered to be a "questionable" genus, was confirmed based on evidences from morphology, ecology, and molecular data; (5) Protorhabdonella and Rhabdonella showed rather low intergeneric distance and grouped together with strong support suggesting that Rhabdonellidae is a well-defined taxon; and (6) Epiplocyloides branched with species in Cyttarocylididae indicating their close relationship.

Predictive factors for lymph node metastasis in patients with poorly differentiated early gastric cancer

BACKGROUND

Endoscopic submucosal dissection is gaining popularity in the treatment of early gastric cancer. This study aimed to identify clinicopathological factors predictive of lymph node metastasis in patients with the poorly differentiated early gastric cancer to assess the feasibility of using endoscopic submucosal dissection for these cancers.

METHODS

The records of patients with poorly differentiated early gastric cancer who had undergone gastric cancer surgery between January 2002 and December 2009 were reviewed. Associations between clinicopathological factors and the presence of lymph node metastasis were analysed by univariable and multivariable logistic regression analysis.

RESULTS

Some 1005 patients were included in the analysis. Univariable analysis indicated that lymph node metastasis was associated with sex, ulceration, tumour size, depth of invasion, macroscopic type, lymphatic invasion and venous invasion. Logistic regression revealed that lymph node metastasis was significantly associated with sex, tumour size, depth of tumour invasion and lymphatic involvement. In the group with none of these risk factors (men with mucosal tumour no larger than 2 cm in size, with no lymphatic involvement), lymph node metastasis was present in four (3·2 per cent) of 124 patients.

CONCLUSION

In the present study 3·2 per cent of patients who were negative for all identified risk factors had lymph node metastasis. The use of endoscopic submucosal dissection should be considered carefully in the treatment of poorly differentiated early gastric cancer.

Synthesis and electroplating of high resolution insulated carbon nanotube scanning probes for imaging in liquid solutions

High resolution and isolated scanning probe microscopy (SPM) is in demand for continued development of energy storage and conversion systems involving chemical reactions at the nanoscale as well as an improved understanding of biological systems. Carbon nanotubes (CNTs) have large aspect ratios and, if leveraged properly, can be used to develop high resolution SPM probes. Isolation of SPM probes can be achieved by depositing a dielectric film and selectively etching at the apex of the probe. In this paper the fabrication of a high resolution and isolated SPM tip is demonstrated using electron beam induced etching of a dielectric film deposited onto an SPM tip with an attached CNT at the apex.

Airway obstruction by extrinsic tracheal compression during spinal surgery under prone position -A case report-

Tracheal compression by vascular anomalies in adults is uncommon and most related reports are of children. A 79-year-old woman without any respiratory history underwent a lumbar spine surgery under general anesthesia. She suddenly developed airway obstruction after a position change from supine to prone. A fiberoptic bronchoscopy showed the obstruction of endotracheal tube. The obstruction was relieved after we changed the depth of endotracheal tube and supported the patient's neck with a cotton roll. The surgery ended without any other event and the patient recovered safely. A computed tomography revealed the rightward tracheal deviation and tortuous innominate artery contact with trachea. The patient didn't manifest any respiratory related symptoms during postoperative period, and she was discharged without any treatment.

Anesthetic experience of methemoglobinemia detected during general anesthesia for gastrectomy of advanced gastric cancer -A case report-

Methemoglobinemia is an uncommon but potentially fatal disorder. Most cases have no adverse clinical consequence and require no treatment, but methemoglobinemia is often overlooked as a cause of low oxygen saturation, and often mistaken for the more common causes of hypoxia by anesthesiologists despite simple bedside tests that indicate the presence of this treatable abnormality. We present a 68-year-old female patient who underwent gastrectomy for advanced gastric cancer with bleeding. In the preoperative period, the patient showed cyanosis and oxygen saturation was 85% by pulse oximeter, but oxygen saturation by arterial blood gas analysis was 100%. After tracheal intubation, the methemoglobin level was 18.3%. Ascorbic acid and methylene blue were administered. During preanesthetic evaluation, the patient had not informed the anesthesiologist that she had been taking dapsone.

Surgical outcome after incomplete endoscopic submucosal dissection of gastric cancer

BACKGROUND

Endoscopic resection of early gastric cancer is a relatively new and attractive treatment, but occasionally fails to remove all cancer lesions completely. This study aimed to elucidate clinicopathological factors that could be helpful in predicting residual tumour in the surgical specimen after incomplete endoscopic submucosal dissection (ESD).

METHODS

Patients who underwent gastrectomy because of incomplete ESD between August 2004 and August 2008 were analysed. Clinicopathological characteristics were reviewed retrospectively from prospectively collected medical records. Patients were classified into groups with and without residual tumour. Pathology results following gastrectomy were compared with those of incomplete ESD.

RESULTS

A total of 118 patients were included. The incidence of residual tumour in the surgical specimen was 24·6 per cent after incomplete ESD. Elevated/flat-type cancers, large tumours (at least 2 cm) and those limited to the mucosa had significantly higher incomplete ESD rates. Cancer limited to the mucosa and the presence of tumour in the lateral margin were associated with residual tumour in the surgical specimen (both P = 0·001).

CONCLUSION

Radical gastrectomy should be performed if pathological examination reveals a positive lateral resection margin after ESD.

Enhanced production of oceanic dimethylsulfide resulting from CO₂-induced grazing activity in a high CO₂ world

Oceanic dimethylsulfide (DMS) released to the atmosphere affects the Earth's radiation budget through the production and growth of cloud condensation nuclei over the oceans. However, it is not yet known whether this negative climate feedback mechanism will intensify or weaken in oceans characterized by high CO(2) levels and warm temperatures. To investigate the effects of two emerging environmental threats (ocean acidification and warming) on marine DMS production, we performed a perturbation experiment in a coastal environment. Two sets of CO(2) and temperature conditions (a pCO(2) of ∼900 ppmv at ambient temperature conditions, and a pCO(2) of ∼900 ppmv at a temperature ∼3 °C warmer than ambient) significantly stimulated the grazing rate and the growth rate of heterotrophic dinoflagellates (ubiquitous marine microzooplankton). The increased grazing rate resulted in considerable DMS production. Our results indicate that increased grazing-induced DMS production may occur in high CO(2) oceans in the future.

Description of a new planktonic mixotrophic dinoflagellate Paragymnodinium shiwhaense n. gen., n. sp. from the coastal waters off Western Korea: morphology, pigments, and ribosomal DNA gene sequence

The mixotrophic dinoflagellate Paragymnodinium shiwhaense n. gen., n. sp. is described from living cells and from cells prepared by light, scanning electron, and transmission electron microscopy. In addition, sequences of the small subunit (SSU) and large subunit (LSU) rDNA and photosynthetic pigments are reported. The episome is conical, while the hyposome is hemispherical. Cells are covered with polygonal amphiesmal vesicles arranged in 16 rows and containing a very thin plate-like component. There is neither an apical groove nor apical line of narrow plates. Instead, there is a sulcal extension-like furrow. The cingulum is as wide as 0.2-0.3 x cell length and displaced by 0.2-0.3 x cell length. Cell length and width of live cells fed Amphidinium carterae were 8.4-19.3 and 6.1-16.0 microm, respectively. Paragymnodinium shiwhaense does not have a nuclear envelope chamber nor a nuclear fibrous connective (NFC). Cells contain chloroplasts, nematocysts, trichocysts, and peduncle, though eyespots, pyrenoids, and pusules are absent. The main accessory pigment is peridinin. The sequence of the SSU rDNA of this dinoflagellate (GenBank AM408889) is 4% different from that of Gymnodinium aureolum, Lepidodinium viride, and Gymnodinium catenatum, the three closest species, while the LSU rDNA was 17-18% different from that of G. catenatum, Lepidodinium chlorophorum, and Gymnodinium nolleri. The phylogenetic trees show that this dinoflagellate belongs within the Gymnodinium sensu stricto clade. However, in contrast to Gymnodinium spp., cells lack nuclear envelope chambers, NFC, and an apical groove. Unlike Polykrikos spp., which have a taeniocyst-nematocyst complex, P. shiwhaense has nematocysts without taeniocysts. In addition, P. shiwhaense does not have ocelloids in contrast to Warnowia spp. and Nematodinium spp. Therefore, based on morphological and molecular analyses, we suggest that this taxon is a new species, also within a new genus.

Low frequency mutation of the Ephrin receptor A3 gene in hepatocellular carcinoma

EphA3 is a component of the Eph/ephrin tyrosine kinase system, which participates in vasculature development. This receptor/ligand system is associated with various signaling pathways related to cell growth and viability, cytoskeletal organization, cell migration, and anti-apoptosis. Accumulated evidence suggests that aberrant regulation of EphA3 and its genetic alterations are implicated in the development and progression of various cancers. However, despite a high incidence of EphA3 over-expression, no such investigation has been performed in hepatocellular carcinoma. Thus, we investigated genetic alterations of the EphA3 gene in 73 cases of hepatocellular carcinoma by single-strand conformational polymorphism and sequencing. One novel D219V missense mutation was found in the extracellular domain of EphA3, and two genetic alterations in the intracellular sterile-alpha-motif (SAM) domain of EphA3 appeared to be polymorphisms. Although the functional assessments of this mutant are incomplete, it is believed that this novel EphA3 mutation may contribute to the development of hepatocellular carcinoma.

Phylogenetic diversity of Synechococcus strains isolated from the East China Sea and the East Sea

Phylogenetic relationships among 33 Synechococcus strains isolated from the East China Sea (ECS) and the East Sea (ES) were studied based on 16S rRNA gene sequences and 16S-23S rRNA gene internal transcribed spacer (ITS) sequences. Pigment patterns of the culture strains were also examined. Based on 16S rRNA gene and ITS sequence phylogenies, the Synechococcus isolates were clustered into 10 clades, among which eight were previously identified and two were novel. Half of the culture strains belonged to clade V or VI. All strains that clustered into novel clades exhibited both phycoerythrobilin and phycourobilin. Interestingly, the pigment compositions of isolates belonging to clades V and VI differed from those reported for other oceanic regions. None of the isolates in clade V showed phycourobilin, whereas strains in clade VI exhibited both phycourobilin and phycoerythrobilin, which is in contrast to previous studies. The presence of novel lineages and the different pigment patterns in the ECS and the ES suggests the possibility that some Synechococcus lineages are distributed only in geographically restricted areas and have evolved in these regions. Therefore, further elucidation of the physiological, ecological, and genetic characteristics of the diverse Synechococcus strains is required to understand their spatial and geographical distribution.

Mutational analysis of JAK1 gene in human hepatocellular carcinoma

The <em>Janus kinase 1</em> (JAK1) gene encodes a cytoplasmic tyrosine kinase that is noncovalently associated with a variety of cytokine receptors and plays a nonredundant role in cell proliferation, survival, and differentiation. The mutated forms of JAK1 often altered the activation of JAK1 and then changed the activation of JAK1/STAT pathways, and this may contribute to cancer development and progression. Thus, to investigate whether genetic mutations of JAK1 gene are associated in hepatocellular carcinoma (HCC) progression, we analyzed genetic alterations of JAK1 gene in 84 human HCCs by single-strand conformational polymorphism (SSCP) and direct sequencing. Of 24 exons of JAK1 gene, 12 exons were previously reported to have mutations, we searched genetic alteration of JAK1 in these exons. Overall, one missense mutation (1.2%) was found. In addition, 12 cases (14%) were found to have single nucleotide polymorphism (14%) in exon 14. Taken together, we found one novel missense mutation of JAK1 gene in hepatocellular carcinomas with some polymorphisms. Although the functional assessment of this novel mutant remains to be completed, JAK1 mutation may contribute to the tumor development in liver cancer.

KEYWORDS

JAK1 gene, hepatocellular carcinoma, mutation.

Decreased expression of p12 is associated with more advanced tumor invasion in human gastric cancer tissues

BACKGROUND/AIMS

p12(DOC-1) is a well-known growth suppressor; however, its role in gastric carcinogenesis is still unclear. We investigated the expression of p12(DOC-1) in gastric cancer tissues and its possible correlation with p53 expression, and determined its clinical significance.

METHODS

Immunohistochemical staining using the tissue array method was performed on 180 human gastric carcinomas. The clinicopathological features and prognostic significance were analyzed.

RESULTS

Of the 180 tissue samples, p53 expression was positive in 85 (47.2%) and p12(DOC-1) expression was negative in 140 (77.8%). The negative expression of p12(DOC-1) was significantly associated with a more advanced depth of tumor invasion and stage (p < 0.05). No apparent correlation was found between p12(DOC-1) and p53 expressions. The 5-year survival rate of the p12(DOC-1)-positive cases (53.7%) was higher than that of the p12(DOC-1)-negative cases (39.3%); however, neither p12(DOC-1) nor p53 expression status had any statistically significant prognostic value. Multivariate analysis revealed that lymph node metastasis, distant metastasis, lymphatic invasion and perineural invasion were independent prognostic factors.

CONCLUSIONS

This is the first report that suggests that p12(DOC-1) may be involved in the development and progression of gastric cancer. Further studies are required to clarify its exact role in the mechanism of gastric carcinogenesis.

Indication for endoscopic mucosal resection in early signet ring cell gastric cancer

BACKGROUND

The aim of this study was to compare the clinicopathological characteristics of an early signet ring cell carcinoma (SRC) with an early undifferentiated carcinoma (mucinous, poorly differentiated adenocarcinoma) and early differentiated carcinoma (well or moderately differentiated tubular adenocarcinoma, papillary adenocarcinoma) and find indications for endoscopic mucosal resection (EMR) in early SRC.

METHODS

1520 patients with early gastric cancer (EGC), who underwent a curative gastrectomy, were analyzed retrospectively. Among them, 388 patients with SRC were compared with 253 patients with undifferentiated carcinoma (UDC) and 879 with a differentiated carcinoma (DC).

RESULTS

SRC was more common in young female patients than UDC. SRC had a tendency to be confined to the mucosa, with smaller size than UDC. The lymph node metastasis rate for SRC was lower than that for UDC, but similar to that of DC. Multivariate analysis revealed lymph node metastasis (LNM) to be associated with the depth of invasion, tumor size, histological type, and lymphatic involvement. SRC had no LNM in the case of a mucosal tumor, smaller than 2 cm, and in the absence of lymphatic involvement. The prognosis of SRC was more favorable than UDC.

CONCLUSIONS

Early SRC has different characteristics from early UDC. In view of the lower rate of lymph node metastasis and better prognosis, we suggest that EMR can be performed on patients with early SRC limited to the mucosa, less than 2cm in size, and with no lymphatic involvement.

Gastric GIST: a single institutional retrospective experience with surgical treatment for primary disease

AIMS

Because gastric GISTs show variable clinical behavior, we reviewed our experience with primary gastric GISTs after surgical treatment and imatinib mesylate treatment for advanced disease.

METHODS

Between December 1995 and December 2005, 111 patients who underwent surgical treatment for primary gastric GISTs were enrolled in this study. Patients were grouped according to the risk assessment classification, and clinicopathological features, tumor recurrence and patient survival were assessed.

RESULTS

One patient was included in the very low risk group, 35 in the low risk group, 31 in the intermediate risk group and 44 in the high-risk group. All patients with very low, low and intermediate risk GISTs and 70% of patients with high risk GISTs underwent R0 resection. While there was no recurrence or metastasis in patients with very low, low and intermediate risk GISTs, 23% of those with high risk GISTs showed a distant metastasis at diagnosis and 35% of these patients had a recurrence after R0 resection. The overall 5-year survival rate of the high risk patients was 77.1%. Nineteen patients received imatinib mesylate therapy due to an incomplete resection or recurrence; 7 with no measurable lesion at the CT scan by a local tumor control showed no tumor progression after imatinib mesylate therapy, however, 12 patients with measurable lesions showed variable clinical courses after treatment. The overall 5-year survival rate of 19 patients with imatinib mesylate treatment was 80.0%.

CONCLUSIONS

The clinical outcome of the very low, low and intermediate risk gastric GISTs was excellent, while high risk gastric GISTs had a high rate of recurrence and therefore a less favorable outcome. A complete resection is the most important treatment for cure; however imatinib mesylate treatment may improve the clinical outcome of the patients with metastatic or recurrent gastric GISTs.

Primary malignant retroperitoneal tumors: Analysis of a single institutional experience

AIMS

In order to achieve complete resection in the surgical management of retroperitoneal tumors, it is crucial to know the tumor's anatomical location relative to neighboring organs.

METHODS

Forty-nine patients with primary malignant retroperitoneal tumors were divided by tumor location into two groups [upper abdomen (group 1) or lower abdomen (group 2)], and clinicopathological features, tumor recurrence, and patient survival were assessed.

RESULTS

No significant differences in preoperative clinical characteristics existed between two groups, and liposarcoma was the most frequently observed tumor type. The difference in the rates of complete resection between the two groups was not statistically significant (75.9% for group 1 and 85% for group 2). En-bloc combined resection was performed in 52% and 30% of patients in groups 1 and 2, respectively. The local recurrence rate in group 2 (31.3%) was higher than that in group 1 (9.5%), despite the fact that the differences in rates of complete resection and distant recurrence rates (14.3% in group 1 and 12.5% in group 2) between the two groups were not statistically significant. The overall 5-year survival rates were 67.9% for group 1 and 43.2% for group 2 (p=0.038). The 5-year survival rate of patients with tumors smaller than 10 cm was 78.4%, while that of patients with tumors larger than 10 cm was 38.1% (p=0.017). The 5-year survival rate after complete excision was 61%, whereas that after incomplete resection or biopsy only was 40.0% (p<0.0001).

CONCLUSIONS

An upper abdominal tumor location is a positive prognostic factor even if small tumor size (<10 cm) and complete resection of the tumor are still more important factors to improve outcome in patients with malignant primary retroperitoneal tumors. Because complete resection was shown to be the most important prognostic factor, an aggressive and careful surgical approach is recommended for the treatment of such tumors.

Prognostic model to predict survival following first-line chemotherapy in patients with metastatic gastric adenocarcinoma

BACKGROUND

This study was to devise a prognostic model for metastatic gastric cancer patients undergoing first-line chemotherapy.

PATIENTS AND METHODS

A retrospective analysis was carried out on 1455 gastric cancer patients, who received first-line chemotherapy from September 1994 to February 2005.

RESULTS

At multivariate level, poor prognostic factors were no previous gastrectomy [P = 0.003; relative risk (RR), 1.191; 95% confidence interval (CI) 1.061-1.338], albumin < 3.6 g/dl (P = or <0.001; RR, 1.245; 95% CI 1.106-1.402), alkaline phosphatase > 85 U/l (P = or <0.001; RR, 1.224; 95% CI 1.092-1.371), Eastern Cooperative Oncology Group performance status of two or more (P = or <0.001; RR, 1.690; 95% CI 1.458-1.959), the presence of bone metastases (P = 0.001; RR, 1.460; 95% CI 1.616-1.836), and the presence of ascites (P = or < 0.001; RR, 1.452; 95% CI 1.295-1.628). Of 1434 patients, 489 patients (34.1%) were categorized as low-risk group (zero to one factors), 889 patients (62.0%) as intermediate-risk group (two to four factors), and 56 patients (3.9%) as high-risk group (five to six factors). Median survival durations for low, intermediate, and high-risk groups were 12.5 months, 7.0 months, and 2.7 months, respectively.

CONCLUSIONS

This model should facilitate the individual patient risk stratification and thus, more appropriate therapies for each metastatic gastric cancer patient.

Depressive symptoms of type 2 diabetics treated with insulin compared to diabetics taking oral anti-diabetic drugs: a Korean study

OBJECTIVE

The purpose of this study was to examine the depressive symptoms of type 2 diabetic patients who were treated with insulin compared to those diabetics treated with oral anti-diabetic drugs in Korea.

METHODS

A total 204 outpatients with type 2 diabetes were invited to complete a questionnaire using the Beck depression inventory (BDI) to measure depressive symptoms. Age, gender, body mass index, serum lipid profile, and a social history including marital status, occupation and educational background were also assessed. The presence of diabetic complications was evaluated by examining the patients' medical records. Diabetic patients who were not treated with anti-diabetic drugs were excluded. All the study subjects were classified into two groups based on their mode of therapy: the oral drug group and insulin group. The insulin group included patients treated with insulin-oral drug combinations as well as those treated solely with insulin.

RESULTS

Overall, 32.4% of our diabetic subjects showed depressive symptoms with the criterion being a BDI score > or = 16. Compared to the oral drug group, the insulin group showed a significantly higher frequency of depressive symptoms (insulin group, 48.0%; oral drug group, 27.3%; p<0.01) and higher BDI scores (insulin group, 16.6+/-10.7; oral drug group, 12.6+/-8.7; p<0.01). Moreover, after an adjustment for social factors, the degree of hyperglycemia and the presence of diabetic complications, the insulin group showed a significantly higher frequency of depression (odds ratio 4.38, 95% CI 1.66-11.6, p=0.003), compared to the oral drug group.

CONCLUSIONS

The data showed that insulin treatment is related to the presence of depressive symptoms, and the importance of more careful psychological support of Korean insulin-treated type 2 diabetic patients is strongly suggested.

Characteristics of submucosal gastric carcinoma with lymph node metastatic disease

AIM

To study the correlation between lymph node metastatic disease and various pathological parameters. Lymph node metastasis is the most important factor in determining the prognosis of patients with early gastric cancer and is significantly associated with the submucosal invasion of neoplastic cells. However, the depth of submucosal layer as well as the depth of submucosal tumour invasion varies among different cases.

METHODS AND RESULTS

We studied various pathological parameters including the macroscopic appearance, location, size, area, differentiation, invasion depth, vascularity and fibrosis of submucosal gastric carcinomas (SMGC), using 248 age- and sex-matched tissue samples. The presence of lymphatic emboli, a larger area, greater size, a non-flat gross type and an increased vascularity of the tumour were significantly associated with node-positive SMGC. Among the three depth-related parameters, the ocular scale measurement, the sm3 method and the sm2 method, only the ocular scale measurement showed a significant correlation with node-positive SMGC. Using multivariate analysis, the incidence of lymph node metastasis increased in the lymphatic tumour emboli and in the tumours that invaded more than half of the submucosal layer.

CONCLUSIONS

These histological indicators seem to be a feasible and easy way to predict lymph node metastatic disease from limited surgery specimens. Pathologists should carefully investigate the lymphatic invasion of tumour cells and measure the invasion depth of the tumour.

Characteristics of submucosal gastric carcinoma with lymph node metastatic disease

AIM

To study the correlation between lymph node metastatic disease and various pathological parameters. Lymph node metastasis is the most important factor in determining the prognosis of patients with early gastric cancer and is significantly associated with the submucosal invasion of neoplastic cells. However, the depth of submucosal layer as well as the depth of submucosal tumour invasion varies among different cases.

METHODS AND RESULTS

We studied various pathological parameters including the macroscopic appearance, location, size, area, differentiation, invasion depth, vascularity and fibrosis of submucosal gastric carcinomas (SMGC), using 248 age- and sex-matched tissue samples. The presence of lymphatic emboli, a larger area, greater size, a non-flat gross type and an increased vascularity of the tumour were significantly associated with node-positive SMGC. Among the three depth-related parameters, the ocular scale measurement, the sm3 method and the sm2 method, only the ocular scale measurement showed a significant correlation with node-positive SMGC. Using multivariate analysis, the incidence of lymph node metastasis increased in the lymphatic tumour emboli and in the tumours that invaded more than half of the submucosal layer.

CONCLUSIONS

These histological indicators seem to be a feasible and easy way to predict lymph node metastatic disease from limited surgery specimens. Pathologists should carefully investigate the lymphatic invasion of tumour cells and measure the invasion depth of the tumour.

Patterns of failure in gastric carcinoma after D2 gastrectomy and chemoradiotherapy: a radiation oncologist's view

The risk of locoregional recurrence in resected gastric adenocarcinoma is high, but the benefit of adjuvant treatment remains controversial. In particular, after extended lymph node dissection, the role of radiotherapy is questionable. Since 1995, we started a clinical protocol of adjuvant chemoradiotherapy after D2 gastrectomy and analysed the patterns of failure for 291 patients. Adjuvant chemotherapy consisted of five cycles of fluorouracil and leucovorin, and concurrent radiotherapy was given with 4500 cGy from the second cycle of chemotherapy. With a median follow-up of 48 months, 114 patients (39%) showed any type of failure, and the local and regional failures were seen in 7% (20 out of 291) and 12% (35 out of 291), respectively. When the recurrent site was analysed with respect to the radiation field, in-field recurrence was 16% and represented 35% of all recurrences. Our results suggest that adjuvant chemoradiotherapy has a potential effect on reducing locoregional recurrence. Moreover, low locoregional recurrence rates could give a clue as to which subset of patients could be helped by radiotherapy after D2 gastrectomy. However, in order to draw a conclusion on the role of adjuvant radiotherapy, a randomised study is needed.

Lack of excess maternal transmission of type 2 diabetes in a Korean population

The purpose of this study was to assess the familial clustering of type 2 diabetes and to investigate the presence of excess maternal transmission of type 2 diabetes in Korea. The medical records of 56,492 subjects (31,680 men and 24,812 women), who attended the Health Promotion Center were examined. The subjects were questioned about their parents' diabetes status. All study subjects were classified into the three groups (normal fasting glucose (NFG), impaired fasting glucose (IFG), and diabetes). Offspring with paternal diabetes (odds ratio 2.54, 95% CI 2.22-2.91, P < 0.001) and those with maternal diabetes (odds ratio 3.10, 95% CI 2.76-3.49, P < 0.001) were at increased risk for diabetes when compared to subjects without parental diabetes and adjusted for other clinical and biochemical variables. Offspring with bilineal parental diabetes were at a greater risk for diabetes (odds ratio 6.09, 95% CI 4.55-8.16, P < 0.001) when compared to subjects without parental diabetes. In both genders, offspring with maternal diabetes showed no increased risk for diabetes (odds ratio 1.22, 95% CI 0.92-1.37, P + 0.266 in men; odds ratio 1.31, 95% CI 0.95-1.81, P = 0.104 in women) when compared with those with paternal diabetes. The data suggested that parental type 2 diabetes was an independent risk factor for offspring type 2 diabetes in this Korean population. Excess maternal transmission of type 2 diabetes was not observed.