• Title/Summary/Keyword: H$_{d}$

Search Result 24,706, Processing Time 0.057 seconds

Evaluation of Maternal Behavior between Normal Parturition and Expected Cesarean Section in Rats (자연 분만 및 예정된 제왕절개 수술 랫드에 있어서 모성 행동의 차이에 대한 검토)

  • Lee, S.K.;Kang, H.G.;Kim, I.W.;Jeong, J.M.;Hwang, D.Y.;Kim, C.K.;Chae, K.R.;Cho, J.S.
    • Journal of Embryo Transfer
    • /
    • v.22 no.3
    • /
    • pp.161-165
    • /
    • 2007
  • Oxytocin is a neurohypophyseal hormone which has multiple functions in mammals. Mainly, oxytocin regulates milk ejection and has an effect on uterine contraction and is related to maternal behavior. Maternal behavior is believed to be suppressed by stress and facilitated by oxytocin. In the cesarean section, oxytocin may be administrated into uterus to promote uterine involution. The present study aimed to test the effect of oxytocin into uterus on maternal behavior of rats with cesarean section. It was measured the effects on maternal behavior of oxytocin infused into uterus in rats with cesarean section as a stressor. In the first experiment, pup survival rate of between a control group and a group with laparotomy as a stress in natural parturition rats was compared. In the second experiment, survival rate for 2 weeks and maternal pup searching behavior (MPSV) were observed in one cesarean sectioned group without oxytocin and the other cesarean sectioned group with oxytocin. Infanticide was observed in stressed group in the first experiment while a normal maternal behavior was observed in a control one. In the second experiment, MPSV was only observed in a cesarean sectioned group with oxytocin and infanticide was observed in two groups except one rat which is thought to be affected by oxytocin as operated relatively late. This is the first study to show that the administration of oxytocin into uterus in the cesarean section is not involved in the regulation of maternal behavior in rats. In conclusion, this study proves the needs of oxytocin into brain in cesarean section related rats model and further study of maternal behavior list, like MPSV.

Microbial Hazard Analysis of Astragalus membranaceus Bunge for the Good Agricultural Practices (농산물우수관리를 위한 황기(Astragalus membranaceus Bunge)의 미생물학적 위해요소 분석)

  • Kim, Yeon Rok;Lee, Kyoung Ah;Kim, Se-Ri;Kim, Won-Il;Ryu, Song Hee;Ryu, Jae-gee;Kim, Hwang-Yong
    • Journal of Food Hygiene and Safety
    • /
    • v.29 no.3
    • /
    • pp.181-188
    • /
    • 2014
  • The objective of this study was to analyze the microbiological hazards of Astragalus membranaceus Bunge on the post-harvest processing. Samples from processing equipments (cleaner, water, cart, table, tray and packaging machine), personal hygiene (hand) and harvested crops (before washing, after washing, after sorting, and after drying) were collected from four farms (A, B, C, and D) located in Chungchengbuk-do, Korea. The samples were analyzed for sanitary indication bacteria and pathogenic bacteria. First, total aerobic bacteria and coliform in processing facilities were detected at the levels of 0.93~4.86 and 0.33~2.28 log CFU/$100cm^2$ and/mL respectively. In particular, microbial contamination in hand (5.43~6.11 and 2.52~4.12 log CFU/Hand) showed higher than processing equipments. Among the pathogenic bacteria, Bacillus cereus was detected at the levels of 0.33~2.41 log CFU/$100cm^2$, 1.48~3.27 log CFU/Hand and 0.67~3.65 log CFU/g in equipments, hands, and plants and Staphylococcus aureus were detected in cleaner, table, hand and harvested crops (before washing and after sorting) by qualitative test. Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella spp. were not detected. These results indicated that personal hygiene and processing equipments should be managed to reduce the microbial contamination of A. membranaceus Bunge. Therefore, management system such as good agricultural practices (GAP) criteria is needed for hygienic agricultural products.

Effects of Dietary Supplementation of Domestic Skullcap (Scutellaria baicalensis) Extracts on Performance, Immune Response and Intestinal Microflora in Broiler Chicken (국내 자생 황금 추출물의 첨가 급여가 육계의 생산성, 면역 기능 및 장내 균총 변화에 미치는 영향)

  • Kwon, H.S.;Kim, J.Y.;Kim, J.S.;Lee, B.K.;Lee, S.Y.;Lee, W.S.;Ahn, B.K.;Kim, E.J.;Kang, C.W.
    • Korean Journal of Poultry Science
    • /
    • v.35 no.4
    • /
    • pp.351-359
    • /
    • 2009
  • This study was carried out to investigate dietary effects of extracts of Skullcap (Scutellaria baicalensis) (SCE) grown in Korea on growth performance, immune and physiological responses in broiler chickens. Total of seven-hundred fifty 1-d-old Ross male broiler chicks were divided into five groups and fed control diets (antibiotics medicated or non-medicated commercial diets) or each experimental diet (non-medicated diets containing 0.1, 0.3 or 0.5% SCE) for 5 weeks. The body weight gain and feed conversion rate in the groups fed diets containing 0.1% or 0.3% SCE were significantly improved as compared with those of non-medicated control group (P<0.05). The levels of total cholesterol and HDL-cholesterol of blood were not influenced by feeding the SCE. The average antibody titers against NDV and IBV in the groups fed diets containing SCE were significantly increased compare to those of the control groups (P<0.05). The number of coli form bacteria was significantly reduced by feeding 0.3% or 0.5% SCE as compared to that of non-medication control (P<0.05). The results demonstrated that the SCE used in this study modulated humoral immunity and the profiles of cecal microflora and thus can be used as a potential alternative substance to replace antibiotics for feeding broiler chicks.

데데킨트 절단, 배중률, 관계

  • Hong, Seong-Gi
    • Korean Journal of Logic
    • /
    • v.7 no.2
    • /
    • pp.15-46
    • /
    • 2004
  • Um die rationalen Zahlen auf die reellen Zahlen zu erweitern und dadurch die Stetigkeit der reellen Zahlen sicherzustellen, hat der deutsche Mathematiker R. Dedekind im Jahr 1872 in seinem Aufsatz "Stetigkeit und Irrationale Zahlen" einen neuen mathmatischen Begriff $eingef\ddot{u}hrt,\;n\ddot{a}mlich$ 'Schnitt'. Die Menge aller rationalen Zahlen Q wird durch eine rationale Zahl a zu zwei Untermengen $A_1=\{x|x{\leq}a,\;x{\in}Q\}$, $A_2=\{x|x>a,\;x{\in}Q\}$ $vollst\ddot{a}ndig$ geteilt. Wenn wir solche Teilung, d.i. solchen Schnitt mit "$(A_1,\;A_2)$" bezeichnen, ist ein $Identit\ddot{a}tssatz$ "a=$(A_1,\;A_2)$" absolut harmlos. Analog dazu glaubt Dedekind fest, $da{\beta}$ jede irrationale Zahl mit Hilfe von einem entsprechenden Schnitt $einzuf\ddot{u}hren$ ist. Zum Beispiel, falls die zwei Mengen $B_1=\{x|x^2<2,\;x{\in}Q\}$ und $B_2=\{x|x^2>2,\;x{\in}Q\}$ gegeben sind, dann $w\ddot{a}re$ die irrationale Zahl $^{\surd}2$ mit $(B_1,\;B_2)$ gleichzusetzen. Im Fall von einem Schnitt der Menge der rationalen Zahlen durch eine rationale Zahl, $(A_1,\;A_2)$, haben die beiden Untermengen $A_1$ und $A_2$ jwewils ein Supremum und ein Infimum und beide $m\ddot{u}ssen$ identisch sein, aber -wie schon Russell in seinem Buch "Introduction to Mathmatical Philosophy" dies kritisiert- hat ein Schnitt $f\ddot{u}r$ die $Einf\ddot{u}hrung$ der irrationalen Zahl, $(B_1,\;B_2)$ keine solche $gl\ddot{u}cklichen$ Eigenschaften. Dennoch glaubt Dedekind an eine streng wissenschaftliche Fundierung der irrationalen Zahl fest, und $w\ddot{u}rde$ nach dem Grund seines Glaubens befragt, $k\ddot{o}nnte$ er nur seine Behauptung wiederholen, ein klarer Fall circulus vitiosus. Mit anderen Worten, die $L\ddot{u}cke$ zwischen $B_1$ und $B_2$ durch die $Einf\ddot{u}hrung$ einer [einzigen] wissenschaftlich fundierten irrationalen Zahl $\ddot{u}berbr\ddot{u}ckt$ und das Ganze zu einem Kontinium gemacht werden sollte, bleibt dieses Vorhaben von Dedekind erst als eine Hoffnung und dessen Resultat kann $h\ddot{o}chstens$ nur als ein Postulat, aber keineswegs als ein methodisch einwandfreier Beweis betrachtet werden. Die Probleme, die mit dem Versuch der $Einf\ddot{u}hrung$ der irrationalen Zahlen mit Hilfe von Schnitt verbunden sind, sind nicht spezifisch allein im Gebient der Mathmatik, sondern betreffen immer wieder die Rechtfertigungsfrage der $Einf\ddot{u}hrung$ der letzten Bestandteile im bezug auf eine Systemerstellung, egal ob dies System ein Wissenschaftliches oder unsere $allt\ddot{a}gliche$ Sprachhandlung ist. $F\ddot{u}r$ all diese Rechtfertigungsfragen gilt das in der klassischen Logik $g\ddot{a}ngige$ logische Prinzip tertium non datur nicht mehr, aber nicht nur wegen der von praktischen $Unm\ddot{o}glichkeit$, die unendlichen vielen $Gegenst\ddot{a}nde$ durchforschen zu $m\ddot{u}ssen$, das $hei{\beta}t$, wegen der erkenntnistheoretischen $Beschr\ddot{a}nktheit$ des jetzigen Erkenntnisniveau, sondern auch wegen des speziellen ontologischen modus der $eizuf\ddot{u}hrenden$ Objekten. Der Autor des Aufsatzes analysiert $\ddot{a}nliche$ $F\ddot{a}lle$ (das Urmeterbeispiel und die Chrakterisierungen der geometrischen Axiome von Wittgenstein), und versucht mit Hilfe von beiden Begriffen, 'interne' und 'externe' Relation, zu zeigen, $da\beta$ eine gemeinsame, invariante Struktur in den eben genannten $F\ddot{a}llen$ besteht. Am Ende des Aufsatzes setzt der Autor sich mit der logischen Argumentationsstruktur des Zitates tiber 'Grenze' aus Noten von Leonardo da Vinci auseinander, und weist auf einen $m\ddot{o}glichen$ Zusammenhang der Grundidee seienes Aufsatzes mit der Philosophie der indischen Denker $N\bar{a}g\bar{a}rjuna$ hin, obwohl die zitierten Versen aus dem Hauptwerk von $N\bar{a}g\bar{a}rjuna$, dem Mittleren Weg$(Madhyamakak\bar{a}rik\bar{a})$ nur andeutend sein $m\ddot{o}gen$.

  • PDF

Bioactivities and Isolation of Functional Compounds from Decay-Resistant Hardwood Species (고내후성 활엽수종의 추출성분을 이용한 신기능성 물질의 분리 및 생리활성)

  • 배영수;이상용;오덕환;최돈하;김영균
    • Journal of Korea Foresty Energy
    • /
    • v.19 no.2
    • /
    • pp.93-101
    • /
    • 2000
  • Wood of Robinia pseudoacacia and bark of Populus alba$\times$P. glandulosa, Fraxinus rhynchophylla and Ulmus davidiana var. japonica were collected and extracted with acetone-water(7:3, v/v) in glass jar to examine whether its bioactive compounds exist. The concentrated extracts were fractionated with hexane, chloroform, ethylacetate and water, and then freeze-dried for column chromatography and bioactive tests. The isolated compounds were sakuranetin-5-O-$\beta$-D-glucopyranoside from Populus alba $\times$Pl glandulosa, 4--ethyoxy-(+)-leucorobinetinidin frm R. pseudoacacia and fraxetion from F. rhynchophylla and were characterized by $^1H$ and$^{13}C $ NMR and positive FAB-MS. Decay-resistant activity was expressed by weight loss ratio and hyphae growth inhibition in the wood dust agar medium inoculated wood rot fungi. R. pseudoacacia showed best anti-decaying property in both test and its methanol untreated samples, indicating higher activity than methanol treated samples in hyphae grwoth test. In antioxidative test, $\alpha$-tocopherol, one of natural antioxidants, and BHT, one of synthetic antioxidants, were used as references to cmpare with the antioxidant activities of the extacted fractions. Ethylacetate fraction of F. rhynchophylla bark indicated the hightest activity in this test and all fractions of R. pseudiacacia extractives also indicated higher activities compared with the other fractions. In the isolated compounds, aesculetin isolated from F. rhynchophylla bark showed best activity and followed by robonetinidin from R. pseudoacaica.

  • PDF

A Study on Development of Prototype Test Train Design in G7 Project for High Speed Railway Technology (G7 고속전철기술개발사업에서의 시제차량 통합 디자인 개발)

  • 정경렬;이병종;윤세균
    • Archives of design research
    • /
    • v.16 no.4
    • /
    • pp.185-196
    • /
    • 2003
  • The demand for an environment-friendly transportation system, equipped with low energy consumption, and low-or zero-pollution has been on the increase since the beginning of the World Trade Organization era. Simultaneously, the consistent growth of high-speed tram technology, combined with market share, has sparked a fierce competition among technologically-advanced countries like France, Germany, and Japan in an effort to keep the lead in high-speed train technology via extensive Research and development(R&D) expenses. These countries are leaders in the race to implement the next-generation transportation system, build intercontinental rail way networks and export the high-speed train as a major industry commodity. The need to develop our own(Korean) 'high-speed train' technology and its core system technology layouts including original technology serves a few objectives: They boost the national competitive edge; they develop an environmental friendly rail road system that can cope with globalization and minimize the social and economic losses created by the growing traffic-congested delivery costs, environment pollution, and public discomforts. In turn, the 'G7 Project-Development of High Speed Railway Technology' held between 1996 and 2002 for a six-year period was focused on designing a domestic train capable of traveling at a speed of 350km/h combined and led to the actual implementation of engineering and producing the '2000 high-speed train:' This paper summarizes and introduces one of the G7 Projects-specifically, the design segment achievement within the development of train system engineering technology. It is true that the design aspect of the Korean domestic railway system program as a whole was lacking when compared with the advanced railroad countries whose early phase of train design emphasized the design aspect. However, having allowed the active participation of expert designers in the early phase of train design in the current project has led to a new era of domestic train development and the implementation of a way to meet demand flexibly with newly designed trains. The idea of a high-speed train in Korea and its design concept is well-conceived: a faster, more pleasant, and silent based Korean high-speed train that facilitates a new travel culture. A Korean-type of high-speed train is acknowledged by passengers who travel in such trains. The Korean high-speed prototype train has been born, combining aerodynamic air-cushioned design, which is the embodiment of Korean original design of forehead of power car minimized aerodynamic resistance using a curved car body profile, and the improvement of the interior design with ergonomics and the accommodation of the vestibule area through the study of passenger behavior and social culture that is based on the general passenger car.

  • PDF

Biodistribution and Hepatic Metabolism of Galactosylated $^{111}In-Antibody-Chelator$ Conjugates: Comparison with $^{111}In-Antibody-Chelator$ Conjugates ($^{111}In$-표지 갈락토즈 접합 항체의 체내분포 및 간에서의 대사 : $^{111}In$-표지 항체와의 비교연구)

  • Kwak, Dong-Suk;Jeong, Kyu-Sik;Ha, Jeoung-Hee;Ahn, Byeong-Cheol;Lee, Kyu-Bo;Paik, Chang-H.;Lee, Jae-Tae
    • The Korean Journal of Nuclear Medicine
    • /
    • v.37 no.6
    • /
    • pp.402-417
    • /
    • 2003
  • Purpose: To evaluate the use of monoclonal antibody (MoAb) as a carrier of the receptor-binding ligand the receptor mediated uptake into liver and subsequent metabolism of $^{111}In-labeled$ galactosylated MoAb-chelator conjugates were investigated and compared with those of $^{111}In$ labeled MoAb. Materials and Methods : T101 MoAb, $IgG_2$ against human lymphocytic leukemic cell, conjugated with cyclic DTPA dianhydride (DTPA) or 2-p-isothiocyanatobenzyl-6-methyl-DTPA (1B4M) was galactosylated with 2-imino-2-methoxyethyl-1-thio-${\beta}$-D-galactose and then radiolabeled with $^{111}In$. Biodistribution and metabolism study was peformed with two $^{111}In-conjugates$ in mice and rats. Results: $^{111}In-labeled$ T101 and its galactosylated conjugates were taken to the liver by the time, mostly within 10 min. However DTPA conjugate was retained longer in the liver than the 1B4M conjugate (55% vs 20% of injected dose at 44 hr). During this time, the radiornetabolite of DTPA conjugate was excreted similarly into urine (24%) and feces (17%). The radiometabolite of 1B4M was excreted primarily into feces (68%) rather than urine (8%). Size exclusion HPLC analysis of the bile and supernatant of liver homogenate showed two peaks the first (35%) with the retention time (Rt) identical to IgG and the second (65%) with Rt similar to free $^{111}In$ at 3 hr post-injection for the 1B4M conjugate, indicating that the metabolite is rapidly excreted through the biliary system. in contrast to DTPA conjugate, the small $^{111}In-DTPA-like$ metabolite was the major radioindium component (90%) in the liver homogenate as early as 3 hour post-injection, but the cumulative radioindium activity in feces was only 17% at 44 hour, indicating that the metabolite from DTPA conjugate does not clear readily through the biliary tract. Conclusion: The galactosylation of the MoAb conjugates resulted in higher hepatocyte uptake and enhanced metabolism, compared to those without galactosylation. Metabolism of the MoAb-conjugates is different between compounds radiolabled with different chelators due to different characteristics of radiometabolites generated in the liver.

Hsp90 Inhibitor Induces Cell Cycle Arrest and Apoptosis of Early Embryos and Primary Cells in Pigs

  • Son, Myeong-Ju;Park, Jin-Mo;Min, Sung-Hun;Hong, Joo-Hee;Park, Hum-Dai;Koo, Deog-Bon
    • Reproductive and Developmental Biology
    • /
    • v.35 no.1
    • /
    • pp.33-45
    • /
    • 2011
  • Heat shock protein 90 (Hsp90) is ATPase-directed molecular chaperon and affects survival of cancer cell. Inhibitory effect of Hsp90 by inducing cell cycle arrest and apoptosis in the cancer cell was reported. However, its role during oocyte maturation and early embryo development is very insufficient. In this study, we traced the effects of Hsp90 inhibitor, 17-allylamino-17-demethoxygeldanamycin (17-AAG), on meiotic maturation and early embryonic development in pigs. We also investigated several indicators of developmental potential, including structural integrity, gene expression (Hsp90-, cell cycle-, and apoptosis-related genes), and apoptosis, which are affected by 17-AAG. Then, we examined the roles of Hsp90 inhibitor on viability of primary cells in pigs. Porcine oocytes were cultured in the NCSU-23 medium with or without 17-AAG for 44 h. The proportion of GV arrested oocytes was significantly different between the 17-AAG treated and untreated group (78.2 vs 34.8%, p<0.05). After completion of meiotic maturation, the proportion of MII oocytes was lower in the 17-AAG treated group than in the control group (27.9 vs 71.0%, p<0.05). After IVF, the percentage of penetrated oocytes was significantly lower in the 17-AAG treated group (25.2%), resulting in lower normal pronucleus formation (2PN of 14.6%). Therefore, the inhibition of meiotic progression by Hsp90 inhibitor played a critical role in fertilization status. Porcine embryo were cultured in the PZM-3 medium with or without 17-AAG for 6 days. In result, significant differences in developmental potential were detected between the embryos that were cultured with or without 17-AAG. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that the number of containing fragmented DNA at the blastocyst stage increased in the 17-AAG treated group compared with control (7.5 vs 4.4, respectively). Blastocysts that developed in the 17-AAG treated group had low structural integrity and high apoptotic nuclei than those of the untreated control, resulting in decrease the embryonic qualities of preimplantation porcine blastocysts. The mRNA expressions of cell cycle-related genes were down-regulated in the 17-AAG treated group compared with control. Also, the expression of the pro-apoptotic gene Bax increased in 17-AAG treated group, whereas expression of the anti-apoptotic gene Bel-XL decreased. However, the expression of ER stress-related genes did not changed by 17-AAG. Cultured pESF cells were treated with or without 17-AAG and used for MIT assay. The results showed that viability of pESF cells were decreased by treatment of 17-AAG ($2{\mu}M$) for 24 hr. These results indicated that 17-AAG decreased cell proliferation and increased cell death. Expression patterns Hsp90 complex genes (Hsp70 and p23), cell cycle-related genes (cdc2 and cdc25c) and apoptosis-related genes (Bax and Bcl-XL) were significantly changed by using RT-PCR analysis. The spliced form of pXbp-1 product (pXbp-1s) was detected in the tunicamycin (TM) treated cells, but it is not detected in 17-AAG treated cells. In conclusion, Hsp90 appears to play a direct role in porcine early embryo developmental competence including structural integrity of blastocysts. Also, these results indicate that Hsp90 is closely associated with cell cycle- and apoptosis-related genes expression in developing porcine embryos.

Risk Factors Related to Uterine Leiomyoma in Korean Women - A Retrospective Study - (한국인 여성에서 자궁근종 발생에 관여하는 인자들에 대한 연구 - 후향적 연구 -)

  • Hong, D.G.;Chung, M.J.;Kim, B.S.;Lee, J.M.;Cho, Y.L.;Lee, T.H.;Chun, S.S.
    • Clinical and Experimental Reproductive Medicine
    • /
    • v.33 no.3
    • /
    • pp.159-170
    • /
    • 2006
  • Objective: The purpose of this study is to find out risk factors related to uterine leiomyoma in Korean women and to compare with the results of previous western studies. Methods: A retrospective analysis was carried out. All the cases of uterine leiomyoma (n=244) were diagnosed surgically or sonographically between Jannuary 1998 and December 2004. Total of 269 controls not having uterine leiomyoma were collected from patients who visited Kyungpook national university hospital for routine gynecologic check-up or treatment of their gynecologic or obstetric diseases other than uterine leiomyoma. Data were collected through review of medical records and interviews and analyzed with $x^2$ and logistic regression model. Results: In multivariate analysis, patient's age (OR 1.070; 95% CI 1.041~1.099), number of artificial abortion (OR 1.182; 95% CI 1.018~1.374) and alcohol drinking (OR 1.865; 95% CI 1.231~2.824) had significantly positive correlation with uterine leiomyoma. The duration of lactation was the only factor which had negative correlation (OR 0.985; 95% CI 0.972~0.998). BMI, parity, age at menarche, the duration and interval of menstruation, caffeine consumption and marital status did not show any correlations. Conclusion: In this study, patient's age, number of artificial abortion, and alcohol drinking were the risk factors of uterine leiomyoma in Korean women and the result was similar to that of western studies. Though we couldn't find out the specific risk factors related to the development of uterine leiomyoma in this study, but it has a great meaning to be the first trial in Korean women. The role of information bias should be carefully evaluated and further multicentered, randomized, controlled prospective studies will be needed to know the possible risk factors among Korean women.

Microbe Hunting: A Curious Case of Cryptococcus

  • Bartlett, Karen H.;Kidd, Sarah;Duncan, Colleen;Chow, Yat;Bach, Paxton;Mak, Sunny;MacDougall, Laura;Fyfe, Murray
    • Proceedings of the Korean Environmental Health Society Conference
    • /
    • 2005.06a
    • /
    • pp.45-72
    • /
    • 2005
  • C. neoformans-associated cryptococcosis is primarily a disease of immunocompromised persons, has a world-wide distribution, and is often spread by pigeons in the urban environment. In contrast, C. gattii causes infection in normal hosts, has only been described in tropical and semi-tropical areas of the world, and has a unique niche in river gum Eucalyptus trees. Cryptococcosis is acquired through inhalation of the yeast propagules from the environment. C. gattii has been identified as the cause of an emerging infectious disease centered on Vancouver Island, British Columbia, Canada. No cases of C. gattii-disease were diagnosed prior to 1999; the current incidence rate is 36 cases per million population. A search was initiated in 2001 to find the ecological niche of this basidiomycetous yeast. C. gaftii was found in the environment in treed areas of Vancouver Island. The highest percentage of colonized-tree clusters were found around central Vancouver Island, with decreasing rates of colonization to the north and south. Climate, soil and vegetation cover of this area, called the Coastal Douglas fir biogeoclimatic zone, is unique to British Columbia and Canada. The concentration of airborne C. gattii was highest in the dry summer months, and lowest during late fall, winter, and early spring, months which have heavy rainfall. The study of the emerging colonization of this organism and subsequent cases of environmentally acquired disease will be informative in planning public health management of new routes of exposure to exotic agents in areas impacted by changing climate and land use patterns. Cryptococcosis is an infection associated with an encapsulated, basidiomycetous yeast Cryptococcus neoformans. The route of entry for this organism is through the lungs, with possible systemic spread via the circulatory system to the brain and meninges. There are four cryptococcal serogroups associated with disease in humans and animals, distinguished by capsular polysaccharide antigens. Cryptococcus neoformans: variety grubii (serotype A), variety neoformans (serotype D), and variety gattii (serotypes B and C) (Franzot et at. 1999). C. neoformans variety gattii has recently been elevated to species status, C. gattii. C. neoformans val. grubii and var. neoformans have a world-wide distribution, and are particularly associated with soil and weathered bird droppings. In contrast, C. gattii (CG) is not associated with bird excrement, is primarily found in tropical and subtropical climates, and has a restricted environmental niche associated with specific tree species. (Ellis & Pfiffer 1990) Ellis and Pfeiffer theorize that, as a basidiomycete, CG requires an association with a tree in order to become pathogenic to mammals. In Australia, CG has been found to be associated with five species of Eucalypts, Eucalyptus camaldulensis, E. tereticornis, E. blakelyi, E. gomphocephala, and E. rudis. Eucalypts, although originally native to Australia, now have a world-wide distribution. CG has been found associated with imported eucalypts in India, California, Brazil, and Egypt. In addition, in Brazil and Columbia, where eucalypts have been naturalized, native trees have been shown to harbour CG (Callejas et al. 1998; Montenegro et al. 2000). In British Columbia, Canada, since the beginning of 1999, there have been 120 confirmed cases of cryptococcal mycoses associated with CG in humans, including 4 fatalities (data from British Columbia Centre for Disease Control), and over 200 cases in animal pets in BC (data from Central Laboratory for Veterinarians). What is remarkable about the BC outbreak of C. gattii-cryptococcosis is that all of the cases have been residents of, or visitors to, a narrow area along the eastern coast of Vancouver Island, BC, from the tip of the island in the south (Victoria) to Courtenay on the north-central island as illustrated in Figure 1. Of the first 38 human cases, 58% were male with a mean age of 59.7 years (range 20 - 82): 36 cases (95%) were Caucasian. Ten cases (26%) presented with meningitis, the remainder presented with respiratory symptoms. Cultures recovered from cases of cryptococcosis associated with the outbreak were typed as serogroup B, which is specific to CG (Bartlett et al. 2003). This was the first reported outbreak of CVG in Canada, or indeed, the world. Where infection with CG is endemic, for example, Australia, the incidence of cryptococcosis ranges from 1.8 - 4.7 per million between the southern and northern states (Sorrell 2001). However, the overall incidence of cryptococcosis in immunocompenent individuals has been estimated at 0.2 per million population per year (Kwon-Chung et al. 1984). The population of Vancouver Island is approximately 720,000,consequently, even if the organism were endemic, one would expect a maximum of 0.15 cases of cryptococcal disease annually.

  • PDF