Pemphigus vulgaris (PV) is an antibody-mediated autoimmune disease of the skin and mucous membranes. Desmoglein-3 (dsg-3) expressed in the suprabasal layer of the skin serves as an autoantigen in PV. Passive transfer of sera, either from patients with PV or from experimental animals immunized with a recombinant human dsg3 (hdsg3) into neonatal BALB/c mice results in blister formation, suggesting strongly that there is significant cross-reactivity between the mouse dsg3 (mdsg3) and the hdsg3. However, efforts to induce disease in adult mice through active immunization using hdsg-3 have not been successful, suggesting that the epitopes required for the induction of pathogenic antibodies in adult mice might not be present in hdsg3. Therefore, in this study, we expressed a full-length mdsg3 in insect cells and compared its serological reactivity with that of the hdsg3 using species specific polyclonal sera and a panel of seven monoclonal antibodies (MoAbs) with unique binding specificities to hdsg3. Studies using sera demonstrated a considerable cross-reactivity, while studies using MoAbs exhibited specific epitope differences between the two proteins. Because of these differences, we reasoned that immunization with mdsg3 might induce disease in adult mice. Immunization of four strains of mice (i.e. BALB/c, DBA/1, HRS/J and SJL/J) with mdsg3 resulted in considerable antibody response, but failed to induce lesions. However, sera from immunized BALB/c mice induced acantholysis of neonatal mouse skin in vitro. These studies indicated that our inability to induce lesions in adult mice through active immunization is not due to differences in the ability of mouse and human dsg3 to induce acantholytic antibodies, but due probably to structural differences between adult and neonatal mouse skin. Alternatively, immunization with a combination of dsg3 protein along with other proteins might be necessary to induce pemphigus disease in adult mice. Nevertheless, our current studies show that molecular mechanisms leading to the production of acantholytic antibodies in mice can now be studied using homologous mdsg3.

Animals↗

PubMed2003

Surviving the sex trade: a comparison of HIV risk behaviours among street-involved women in two Canadian cities who inject drugs.

In Canada, very little is known about the factors and processes that cause drug-related harm among female intravenous drug users (IDUs). Women who inject drugs and participate in the survival sex trade are considered to be at increased risk for sexual and drug-related harms, including HIV infection. Between September 1999 and September 2000, women participating in the VIDUS cohort in Vancouver and the St. Luc Cohort in Montreal completed interviewer-administered questionnaires. Analyses were conducted to compare the demographic characteristics, sexual risk behaviours, risky injection practices and drug use patterns among women who self-identified as participating in the sex trade with those who did not identify as participating in the sex trade. Logistic regression was used to identify factors independently associated with exchanging sex for money or drugs. HIV prevalence at the study visit (September 1999-2000) was 29% for sex trade workers and 29.2% for non-sex trade workers. While patterns of sexual risk were similar, the risky injection practice and drug use patterns between sex trade workers and non-sex trade workers were markedly different. Logistic regression analysis of cross-sectional data revealed that independent behaviours associated with the sex trade included: greater than once per day use of heroin (adjusted OR 2.7), smokeable crack cocaine (adjusted OR = 3.3) and borrowing used syringes (adjusted OR = 2.0). Creative, client-driven interventions are urgently needed for women who trade sex for money or for drugs.

Adolescent↗

PubMed2003

Trypan blue staining of internal limiting membrane and epiretinal membrane during vitrectomy: visual results and histopathological findings.

AIMS: To report on the use of trypan blue (TB) 0.06% for staining the internal limiting membrane (ILM) and epiretinal membrane (ERM) during vitrectomy and report on their histology. METHOD: 14 consecutive patients with idiopathic macular hole or macular pucker (seven patients each) were prospectively recruited for ILM or ERM peel respectively. After pars plana vitrectomy and induction of posterior vitreous detachment, 0.5 ml TB 0.06% in phosphate buffered saline (VisonBlue) was injected over the posterior pole in an air filled eye and left for 2 minutes. The stained tissue was peeled with intraocular forceps. Specimens were evaluated using histochemical and immunohistochemical methods. RESULTS: The average follow up was 4.4 months. Internal limiting membranes and epiretinal membranes were stained satisfactorily in all cases and removed successfully. Eight patients (57%) had improvement of 2 or more Snellen lines. All seven macular holes closed. In the ERM cases, no residual membranes were observed clinically, at the latest follow up. No complications relating to the use of the dye were encountered intraoperatively or postoperatively. Of the 14 procedures, nine (four macular hole and five macular pucker) yielded sufficient tissue for histopathological evaluation. Histological and immunohistological assessment revealed that the morphology of these specimens was similar to that observed in macular hole ILM and macular pucker ERM removed without the aid of dye. CONCLUSION: TB staining facilitated the identification and delineation of ILM and ERM removal during the surgical management of macular holes and macular pucker. The visual outcome of this series and the specimens removed suggest they are no different from those without TB staining. Its use in posterior segment appears to be safe but further studies are required to investigate its long term safety.

Adult↗

PubMed2003

Macular relocation after photodynamic therapy for recurrent choroidal neovascular membrane: visual results and histopathological findings.

BACKGROUND/AIMS: The findings in a patient treated with photodynamic therapy (PDT) followed by macular relocation surgery (MRS) are presented. METHODS: Histopathological evaluation of the choroidal neovascular membrane (CNV) specimen including immunohistochemical assessment. RESULTS: Microscopy revealed one CNV area that was richly vascular with attached retinal pigment epithelial cell monolayer and another area that was made up of densely collagenous avascular tissue with adherent fragments of Bruch's membrane and glial elements. CONCLUSION: The findings suggest that the PDT treated part of the CNV may have been adherent to the neuroretina and may have contributed to the formation of the macular hole. Caution is advised when considering MRS for CNV previously treated PDT.

Aged↗

PubMed2003

Proinflammatory and anti-inflammatory cytokine responses in preterm infants with systemic infections.

OBJECTIVE: A prospective study to investigate the pattern of proinflammatory and anti-inflammatory cytokine responses in preterm infants with systemic infection. METHODS: Very low birthweight infants in whom infection was suspected when they were > 72 hours of age were eligible. A full sepsis screen was performed in each episode. Key cytokines of both proinflammatory and anti-inflammatory pathways, including interleukin (IL) 2, IL4, IL5, IL6, IL10, interferon (IFN) gamma, and tumour necrosis factor (TNF) alpha, were measured at 0 (at the time of sepsis evaluation), 24, and 48 hours by flow cytometric analysis or immunoassay. RESULTS: Thirty seven of the 127 episodes of suspected clinical sepsis were proven infection or necrotising enterocolitis. Both proinflammatory (IL2, IL6, IFNgamma, TNFalpha) and anti-inflammatory (IL4, IL10) cytokines were significantly increased in infected infants compared with non-infected infants. Significant correlations were observed between IL6 and TNFalpha or IL10 as well as IL10 and IFNgamma in infected infants. In the subgroup analysis, plasma IL6, IL10, and TNFalpha concentrations, and IL10/TNFalpha and IL6/IL10 ratios were significantly elevated in patients with disseminated intravascular coagulation compared with infected infants without. The IL10/TNFalpha ratios had decreased significantly 48 hours after the onset, whereas the IL6/IL10 ratio showed only a non-significant decreasing trend. Further, the IL6/IL10 ratio in the deceased infant was disproportionally increased at presentation and continued to increase despite treatment. CONCLUSION: The results indicate that the counter-regulatory mechanism between the proinflammatory and anti-inflammatory cytokine pathways is probably operational in preterm infants of early gestation. High plasma IL6, IL10, and TNFalpha concentrations, and IL10/TNFalpha and IL6/IL10 ratios signify severe infection, but transiently elevated plasma IL10 concentration or IL10/TNFalpha ratio does not necessarily indicate a poor prognosis.

C-Reactive Protein↗

PubMed2003

Assignments of GRB7, GCN5L2, COL1A1 and TBCD to pig chromosome 12 by radiation hybrid mapping.

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Animals↗

PubMed2003

High pregnancy rates and reproductive health indicators among female injection-drug users in Vancouver, Canada.

OBJECTIVE: To determine the incidence of pregnancy among active injection-drug users and to identify factors associated with becoming pregnant. METHODS: The Vancouver Injection Drug User Study (VIDUS) is a prospective cohort study that began in 1996. Women who had completed a baseline and at least one follow-up questionnaire between June 1996 and January 2002 were included in the study. Parametric and non-parametric methods were used to compare characteristics of women who reported pregnancy over the study period with those who did not over the same time period. RESULTS: A total of 104 women reported a primary pregnancy over the study period. The incidence of pregnancy over the follow-up period was 6.46 (95% confidence interval (CI) 5.24-7.87) per 100 person-years. The average age of women who reported pregnancy was younger than that of women who did not report pregnancy (27 vs. 32 years, p < 0.001). Women of Aboriginal ethnicity were more likely to report pregnancy (odds ratio 1.6, 95% CI 1.0-2.5). Comparison of drug use showed no significant differences in pregnancy rate with respect to the use of heroin, cocaine or crack (p > 0.05). In examining sexual behavior, women who reported having had a regular partner in the previous 6 months were three times more likely to have reported pregnancy. Despite the fact that 67% of women in this study reported using some form of contraception, the use of reliable birth control was low. Only 5% of women in our study reported the use of hormonal contraceptives. CONCLUSION: There were a high number of pregnancies among high-risk women in this cohort. This corresponded with very low uptake of reliable contraception. Innovative strategies to provide reproductive health services to at-risk women who are injecting drugs is a public health priority.

Adult↗

PubMed2002

Degradation of non-phenolic lignin by the white-rot fungus Pycnoporus cinnabarinus.

High-molecular-weight lignin was methylated with diazomethane. The lignin (i.e., phenolic lignin) and methylated lignin (i.e., non-phenolic lignin) were mixed with fully bleached softwood pulp. Degradation of the lignin preparations by the white rot fungus Pycnoporus cinnabarinus was studied. After a 3-month incubation with the fungus, over 40% of the non-phenolic lignin and about 70% the phenolic lignin were degraded. The presence of phenolic hydroxyl groups in lignin greatly enhanced the degradation rate of lignin. This study reveals that P. cinnabarinus, an exclusively laccase-producing fungus, is capable of oxidatively degrading both phenolic and non-phenolic lignins. The ability of the fungus to degrade non-phenolic lignin suggests that a laccase/mediator system is involved in the complete degradation of lignin. After the fungal degradation of lignins, the content of carboxylic acids substantially increased for both phenolic and non-phenolic lignins.

Biodegradation, Environmental↗

PubMed2002

Characterization and source identification of hydrocarbons in water samples using multiple analytical techniques.

This paper describes a case study in which multiple analytical techniques were used to identify and characterize trace petroleum-related hydrocarbons and other volatile organic compounds in groundwater samples collected in a bedrock aquifer exploited for drinking water purposes. The objective of the study was to confirm the presence of gasoline and other petroleum products or other volatile organic pollutants in those samples in order to assess the respective implication of each of the potentially responsible parties to the contamination of the aquifer. In addition, the degree of contamination at different depths in the aquifer was also of interest. The analytical techniques used for analyses of water samples included gas chromatography-mass spectrometry (GC-MS) and capillary GC with flame-ionization detection, solid-phase microextraction and headspace GC-MS techniques. Chemical characterization results revealed the following: (1) The hydrocarbons in sample A (near-surface groundwater, 0-5 m) were clearly of two types, one being gasoline and the other a heavy petroleum product. The significant distribution of five target petroleum-characteristic alkylkated polycyclic aromatic hydrocarbon homologues and biomarkers confirmed the presence of another heavy petroleum product. The concentrations of the TPHs (total petroleum hydrocarbons) and BTEX (collective name of benzene, toluene, ethylbenzene, and p-, m-, and o-xylenes) were determined to be 1070 and 155 microg/kg of water for sample A, respectively. (2) The deepest groundwater (sample B, collected at a depth ranging between 15 and 60 m) was also contaminated, but to a much lesser degree. The concentrations of the TPH and BTEX were determined to be only 130 and 2.6 microg/kg of water for sample B, respectively. (3) The presence of a variety of volatile chlorinated compounds to the groundwater was also clearly identified.

Chromatography, Gas↗

PubMed2002

Cobblestone area-forming cells, long-term culture-initiating cells and NOD/SCID repopulating cells in human neonatal blood: a comparison with umbilical cord blood.

Our prior study demonstrated that neonatal blood (NB) contained hematopoietic stem and progenitor cells that declined rapidly after birth. To validate that NB is a source of functional stem cells, we characterized this population in terms of cobblestone area-forming cells (CAFC), long-term culture-initiating cells (LTC-IC) and NOD/SCID mouse repopulating cells (SRC) in NB and umbilical cord blood (CB). Our data demonstrated that the frequencies of CAFC (30.2 vs 37.1, P = 0.14) and LTC-IC (28.6 vs 31.0, P = 0.49) in 1 x 10(5) mononuclear cells (MNC) of NB and CB were similar, suggesting that these cells were preserved in the circulation of the neonates shortly after birth. Sublethally irradiated NOD/SCID mice were transplanted with CD34(+) cells enriched from thawed NB and CB. At 6 weeks post transplant, human (hu)CD45(+) cells were detected in the bone marrow (BM), spleen and peripheral blood (PB) of the mice as demonstrated by flow cytometric and DNA analysis. Levels of huCD45(+)cells and colony forming units (CFU) appeared to be dependent on the infusion cell dose and were higher in animals receiving CB cells when compared with those of the NB group. The transplanted cells were capable of differentiation into multi-lineage progenitor cells (CD34(+) cells and differential CFU), as well as mature myeloid (CD14(+), CD33(+)), B lymphoid (CD19(+)) and megakaryocytic (CD61(+)) cells in the recipients. NB cells, subjected to ex vivo culture in an optimized preclinical condition, were significantly expanded to early and committed progenitor cells. Expanded NB contained SRC at a reduced quantity but with high proportions of CD14(+) cells and CD33(+) cells. Our study confirms that NB contains pluripotent hematopoietic stem and progenitor cells capable of homing and engrafting the NOD/SCID mice.

Animals↗

PubMed2002

Phylogenetic relationships of Asian and European pig breeds determined by mitochondrial DNA D-loop sequence polymorphism.

Phylogenetic relationships among Asian and European pig breeds were assessed using 1036 bp of mitochondrial DNA (mtDNA) D-loop sequences. An unweighted pair-group method with arithmetic mean (UPGMA) tree was constructed on the basis of maximum likelihood distances using sequences determined for three Cheju (Korea), 11 Chinese, one Westran (Australian feral origin) and two European pigs (Berkshire and Welsh), and also published sequences for four Japanese (including two Wild Boars), one Yucatan miniature, five European (including Large White, Landrace, Duroc, Swedish and Wild Boar) and two Meishan pigs. The Colombian collared peccary (Tayassu tajacu) sequence was also determined and used as an outgroup. The maximum parsimony with heuristic search method was used to determine bootstrap support values. Asian-type pigs clustered together (bootstrap support 33%), but were separate from European-type pigs that also clustered together (93%). The Westran pig, derived from the feral descendants of pigs inhabiting Kangaroo Island of South Australia, clustered with Asian pigs, demonstrating Asian origin of their mitochondria. Berkshire and Large White clustered with Asian pigs, indicating that Asian pigs were involved in the development of these breeds. Our findings clearly demonstrate that pigs indigenous to China, Korea and Japan are only recently diverged from each other and distinctly different from European-type pigs. European pig breeds consist of pigs with mitochondria of Asian and non-Asian type, some of which were formed from closely related maternal ancestors, if not from a single ancestor.

Animals↗

PubMed2002

Isolation, physical mapping and polymorphism of the porcine ferredoxin reductase (FDXR ) gene.

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Alleles↗

PubMed2002

Genetic variation analysis within and among Chinese indigenous swine populations using microsatellite markers.

The genetic structure of five types of Taihu pig (Erhualian, Middle Meishan, Small Meishan, Mizhu and Shawutou), Jiangquhai and Dongchuan pigs in China were investigated, by means of 27 microsatellite markers proposed by the Food and Agriculture Organisation, International Society for Animal Genetics (FAO-ISAG). The Hardy-Weinberg equilibrium test indicated that genetic drift had occurred in these populations, which may be caused by founder effects, intensive selection and close breeding. Genetic heterozygosity and the effective number of alleles per population were calculated, and showed that the genetic variability of the Jiangquhai pig was the largest, while the Small Meishan had the lowest. Genetic differentiation was within each population as shown by the fixation index (F(ST)=0.18). Both a neighbour-joining (NJ) tree constructed from Nei's standard genetic distance and principal component analysis based on allele frequencies can distinguish types of Taihu pig from the other two breeds. Among Taihu pig populations, Erhualian and Mizhu grouped into one branch, while Middle Meishan, Small Meishan and Shawutou clustered as another branch. By including previously published data on European pigs reported, we confirmed that Chinese indigenous pigs and European pigs have diverged into two distinct groups.

Alleles↗