RETRACTED: Isolation, characterization and expression of a gene from Brassica napus encoding a LIM-domain protein

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Characterisation of two enteroviruses isolated from Australian brushtail possums (Trichosurus vulpecula) in New Zealand

Two enteroviruses, designated W1 and W6, were isolated from intestinal contents of Australian brushtail possums (Trichosurus vulpecula) in New Zealand. The genomic sequences of W1 and W6 were 7390 and 7391 nucleotides (nt), respectively. Genetically, possum isolates W1 and W6 were related to bovine enterovirus serotype 2 (BEV-2) strains, especially to the strain PS87/Belfast, based on the capsid protein sequence. However, W1 and W6 formed a clade that was distinct from PS87Belfast based on nucleotide sequences of the 3' and 5'-non-translated region and in the amino acid sequences of 2A, 3C and 3D. Possum isolates W1 and W6 grew more readily in possum kidney cells than in Madin-Darby bovine kidney (MDBK) cells, suggesting that co-evolution of W1 and W6 with possums has made them more adapted to possum cells.

Neurogenic astrocytes transplanted into the adult mouse lateral ventricle contribute to olfactory neurogenesis, and reveal a novel intrinsic subependymal neuron

Spatially and temporally restricted populations of neurogenic astrocytes can generate multipotent neurospheres in vitro. To examine the ability of neurogenic astrocytes to respond to in vivo differentiation cues within a germinal matrix, we provided cultured neonatal cerebellar astrocytes access to the subependymal zone (SEZ) by grafting them directly into the lateral ventricle of adult mice. Here we report three events that follow such transplants. 1) Donor cells attach to periventricular structures, and form "neoplastic-like" spheres that penetrate the ventricular wall. These attached spheres can persist for months, as they give rise to "clones" of cells that infiltrate forebrain parenchyma. 2) Many donor cells enter the rostral migratory stream and migrate into the olfactory bulb where a small percentage differentiates as olfactory interneurons. 3) Finally, within the SEZ, some donor cells formed cell clusters that appear to interact with the SEZ neuronal precursor chains, and some donor cells differentiate into distinctive neurons with extensive, beady projections precisely confined between the ependymal layer and the striatum. Further analysis of normal SEZ anatomy reveals indigenous neurons with identical morphologies--some of which are contacted by 5-HT+ fibers--that we propose represent a heretofore uncharacterized, intrinsic SEZ neuron of unknown function. These results suggest that cultured astrocytes derived from non-SEZ brain regions can respond in different ways to in vivo cues provided by the adult lateral ventricle and SEZ by differentiating into neurons that eventually inhabit both the olfactory bulb and SEZ proper.

Requirements for the Formation of a Chiral Template

The chemisorptive enantioselectivity of propylene oxide is examined on Pd(111) surfaces templated by chiral 2-methylbutanoate and 2-aminobutanoate species. It has been found previously that chiral propylene oxide is chemisorbed enantiospecifically onto Pd(111) surfaces modified by either (R)- or (S)-2-butoxide. The enantiomeric excess (ee) varied with template coverage, reaching a maximum of approximately 31%. Templating the surface using 2-methylbutanoate, where the chiral center is identical to that in the 2-butoxide species, but is now anchored to the surface by a carboxylate rather than an alkoxide linkage, shows no enantiospecificity. The enantioselectivity is restored when the methyl group is replaced by an amine group, where a maximum ee value of approximately 27% is found. DFT calculations and infrared measurements suggest that the structures of the butyl group on the surface are similar for both 2-butoxide and 2-methylbutanoate species, implying that gross conformational changes are not responsible for differences in chemisorptive enantioselectivity. There is no clear correlation between the location of the chiral center and enantioselectivity, suggesting that differences in the template adsorption site are also not responsible for the lack of enantioselectivity. It is proposed that the 2-butyl group in 2-methylbutanoate species is less rigidly bonded to the surface than that in 2-butoxides, allowing the chiral center to rotate azimuthally. It is postulated that the role of the amino group in 2-aminobutanoate species is to anchor the chiral group to the surface to inhibit azimuthal rotation.

Cigarette smoking and risk of non-Hodgkin lymphoma subtypes among women

Previous studies of the relationship between cigarette smoking and non-Hodgkin lymphoma (NHL) have yielded conflicting results, perhaps because most studies have evaluated the risk for all NHL subtypes combined. Data from a population-based case–control study conducted among women in Connecticut were used to evaluate the impact of cigarette smoking on the risk of NHL by histologic type, tumour grade, and immunologic type. A total of 601 histologically confirmed, incident cases of NHL and 718 population-based controls provided in-person interviews. A standardised, structured questionnaire was used to collect information on each subject's current smoking status, age at initiation, duration and intensity of smoking, and cumulative lifetime exposure to smoking. Our data suggest that cigarette smoking does not alter the risk of all NHL subtypes combined. However, increased risk of follicular lymphoma appears to be associated with increased intensity and duration of smoking, and cumulative lifetime exposure to smoking. Compared with nonsmokers, women with a cumulative lifetime exposure of 16–33 pack-years and 34 pack-years or greater experience 50% increased risk (OR=1.5, 95% CI 0.9–2.5) and 80% increased risk (OR=1.8, 95% CI 1.1–3.2), respectively, of follicular lymphoma (P for linear trend=0.05). Our study findings are consistent with several previous epidemiologic studies suggesting that cigarette smoking increases the risk of follicular lymphoma. This research highlights the importance of distinguishing between NHL subtypes in future research on the aetiology of NHL.

No virus replication in domestic cats fed with RHDV-infected rabbit livers

Previous studies have shown that feral cats (Felis catus) from rabbit haemorrhagic disease (RHD) epidemic areas in New Zealand had antibodies against RHD Virus (RHDV) and RHDV RNA was identified by nested RT-PCR from one seropositive feral cat liver. To assess whether RHDV replicates and produces clinical consequences in cats following the consumption of RHDV-infected rabbit, a challenge trial was conducted by feeding cats RHDV-infected rabbit livers. Antibodies against RHDV were detected by immunoassay from sera of cats collected 10 days after the consumption of RHDV-infected livers. Animals fed four times with RHDV-infected livers, had higher antibody titres than animals fed only once. RHDV RNA was detected by nested RT-PCR from mesenteric lymph nodes, tonsil, spleen and liver of cats fed with RHDV-infected livers. RHDV anti-genomic RNA was also detected by nested RT-PCR from mesenteric lymph nodes collected from one animal 2 days after the fourth feed. RHDV was detected by antigen ELISA from cat faeces 1-2 days after the consumption of RHDV-infected livers. Even though a large amount of RHDV has been used, cats did not show any signs of disease. Although abortive RHDV replication could not be ruled out, active RHDV replication was not demonstrated.

Evaluation of the toxicity of concentrated barley beta-glucan in a 28-day feeding study in Wistar rats

Beta-glucans are water-soluble cell-wall polysaccharides consisting of (1-->3,1-->4)-linked beta-D-glucopyranosyl monomers that comprise a considerable proportion of soluble fiber from certain grains including oats and barley. Consumption of foods containing beta-glucan or beta-glucan-enriched fractions prepared from these grains lower serum cholesterol concentrations in humans and in animal models of hypercholesterolemia. The present study was conducted to evaluate the toxicity of beta-glucan-enriched soluble fiber from barley in Wistar rats on dietary administration at concentrations of 0.7, 3.5 and 7% beta-glucan for 28 days. There were no adverse effects on general condition and behavior, growth, feed and water consumption, feed conversion efficiency, red blood cell and clotting potential parameters, clinical chemistry values, and organ weights. Necropsy and histopathology findings revealed no treatment-related changes in any organ evaluated. A dose-dependent increase in full and empty cecum weight was observed. This is a common physiological response of rodents to high amounts of poorly digestible, fermentable carbohydrates, and was of no toxicological concern. The only finding of possible biological relevance was an increase in the number of circulating lymphocytes observed in males. However, the increase was not dose-dependent and was not observed in females. Results of this study demonstrated that consumption of concentrated barley beta-glucan was not associated with any obvious signs of toxicity in Wistar rats even following consumption of large quantities.

A case-control study of occupation and breast-cancer risk in Connecticut

BACKGROUND

Several occupations have recently been related to breast-cancer. The results, however, are inconsistent. We analyse data from a case-control study of breast cancer in Connecticut conducted in 1994-97 to further examine the potential relationship between occupation and breast-cancer risk.

METHODS

A total of 608 breast-cancer cases and 609 controls, 31-85 years old, were included in the study. Information regarding occupation and other breast-cancer risk-factors was obtained through in-person interviews by trained interviewers, using a standardised, structured questionnaire.

RESULTS

after adjustment for major breast-cancer risk-factors, a significantly increased risk of breast cancer was observed for teachers and librarians [odds ratio (OR), = 1.9, 95% confidence interval (CI) 1.3-2.7]. A significantly reduced risk, on the other hand, was observed for technicians and related supports (OR = 0.5, 95% CI 0.3-0.9). No other occupational groups showed a significant association with breast-cancer risk.

CONCLUSIONS

The observed increase in breast-cancer risk among teachers and librarians is consistent with most earlier studies. It is currently unknown, however, what factors may explain the observed increase. Considering that teachers and librarians represent one of the largest single occupational groups among employed US women, further investigation of this association is warranted.

Glutathione S-transferase M1 and T1 genetic polymorphisms, alcohol consumption and breast cancer risk

Alcohol consumption has been inconsistently associated with breast cancer risk. Recent studies suggest that genetic polymorphisms of glutathione S-transferases (GSTs) may modify this relation. To determine if breast cancer risk is associated with GSTM1 and GSTT1 genetic polymorphisms, and to evaluate the effect modification between GST genotypes and alcohol consumption in the risk of breast cancer, we conducted a case-control study in the state of Connecticut in the period 1998 and 2001. Cases were histologically confirmed, incident breast cancer patients in New Haven County, CT. Controls were randomly selected from women histologically confirmed to be without breast cancer. The study results show that, while GSTM1 genotypes were not associated with breast cancer risk, GSTT1-null genotype was associated with a significant 90% increased risk for postmenopausal women (OR=1.9, 95% CI 1.2-3.0). Analysis by GST genotypes and alcohol consumption shows that GSTM1A ever-drinking women had a 2.5-fold (OR=2.5, 95% CI 1.1-5.5) increased risk of breast cancer compared to the GSTM1A never-drinkers, and the risk increases with duration and daily amount of alcohol consumption. Postmenopausal women with GSTT1-null genotype, who consumed a lifetime of >250 kg of spirit-equivalents, had an almost seven-fold increased risk (OR=6.8, 95% CI 1.4-33.9), and drinking commencing at younger ages appears to carry a higher risk. An OR of 8.2 (95% CI 1.2-57.4) was observed for those with GSTM1A, and GSTT1-null genotypes who had consumed a lifetime of >250 kg of spirit-equivalents. In conclusion, alcohol consumption may increase breast cancer risk among those who carry susceptible GST genotypes.

Use of hair colouring products and breast cancer risk: a case-control study in Connecticut

This case-control study was designed to test the hypothesis that the risk of breast cancer varies by type and colour of the hair colouring products used. A total of 608 cases and 609 controls were included in the study. We found no increased risk associated with the overall use of hair dye products or exclusive use of permanent or temporary types of hair dye products. Among those who reported to have exclusively used semi-permanent types of hair colouring products, some of the ORs were elevated. However, none of the ORs related to age at first use, duration of use, total number of applications, and years since first use, was statistically significant. There was also no increased risk of breast cancer associated with exclusive use of dark or light hair colouring products, or use of mixed types or colours of hair dye products. We also found no increased risk of breast cancer associated with hair dye use based on an individual's reason for using a hair colouring product, such as to cover grey or to change natural hair colour. These data suggest that the use of hair colouring products does not have a major impact on the risk of breast cancer.

Radiation exposure from diagnostic and therapeutic treatments and risk of breast cancer

An association between low-dose diagnostic X-ray exposure or therapeutic radiation treatment and breast cancer risk has not been established. To further investigate the issue, we analysed data from a case-control study of breast cancer in Connecticut in 1994-1997. A total of 1217 subjects (608 breast cancer cases and 609 controls), 30-80 years old, participated in the study. A standardized, structured questionnaire was used to collect information through in-person interviews on diagnostic or therapeutic radiation and other breast cancer risk factors. An odds ratio (OR) of 1.7 (95% confidence interval (CI) 0.8-3.6) was observed for postmenopausal women with therapeutic radiation treatment for skin problems such as ringworm and acne, and an OR of 2.5 (95% CI 1.0-6.8) for those who reported having been treated six or more times. Radiation treatment received at younger ages seems to carry a higher risk. In earlier studies therapeutic radiation for skin problems has been associated with an increased risk of breast cancer. Therefore, it is possible that scattered radiation from these treatments could increase the risk of breast cancer. Radiation exposure from diagnostic X-rays was not associated with a significantly increased risk of breast cancer in this study.

Corticostriatal combinatorics: the implications of corticostriatal axonal arborizations

The complete striatal axonal arborizations of 16 juxtacellularly stained cortical pyramidal cells were analyzed. Corticostriatal neurons were located in the medial agranular or anterior cingulate cortex of rats. All axons were of the extended type and formed synaptic contacts in both the striosomal and matrix compartments as determined by counterstaining for the mu-opiate receptor. Six axonal arborizations were from collaterals of brain stem-projecting cells and the other 10 from bilaterally projecting cells with no brain stem projections. The distribution of synaptic boutons along the axons were convolved with the average dendritic tree volume of spiny projection neurons to obtain an axonal innervation volume and innervation density map for each axon. Innervation volumes varied widely, with single axons occupying between 0.4 and 14.2% of the striatum (average = 4%). The total number of boutons formed by individual axons ranged from 25 to 2,900 (average = 879). Within the innervation volume, the density of innervation was extremely sparse but inhomogeneous. The pattern of innervation resembled matrisomes, as defined by bulk labeling and functional mapping experiments, superimposed on a low background innervation. Using this sample as representative of all corticostriatal axons, the total number of corticostriatal neurons was estimated to be 17 million, about 10 times the number of striatal projection neurons.

[The impact of calpain-10 gene combined-SNP variation on type 2 diabetes mellitus and its related metabolic traits]

OBJECTIVE

To investigate the impact of calpain-10 gene (CAPN-10) combined single nucleotide polymorphism (SNP) variation on type 2 diabetes mellitus (T2DM) and its related clinical metabolic traits in Chinese.

METHODS

The study population consisted of 268 Chinese residents in Shanghai. Among them, 144 were subjects with normal glucose tolerance (NGT) and 124, with T2DM. Plasma glucose (PG), insulin (INS), c-peptide (CP) and free fatty acids (FFA) levels were measured at fasting and 30, 60, 120, and 180 minutes after oral 75 g glucose challenge. The islet beta-cell insulin secretion and tissue insulin sensitivity were assessed. CAPN-10 UCSNP44,-43,-19 and -63 were genotyped.

RESULTS

(1) In Chinese NGT subjects, the major allele of UCSNP-44 was allele T (frequency=91%), of UCSNP43 was G(89%), of UCSNP-19 was I (3 repeats of a 32 bp sequence) (67%) and of UCSNP-63 was C allele (79%). Significant differences were observed in comparison of these allele frequencies in Chinese to those in other ethnic groups reported in the literature. (2) 14 genotype combinations of these four SNPs were observed in Chinese NGT subjects. 69% of the NGT population was composed of four genotype combinations, in the order of UCSNP44,-43,-19 and -63, i.e., combination A:TT-GG-DI-CC(haplotype combination was 1121/1111) (frequency=10%), combination B:TT-GA-II-CC(1121/1221)(10%), combination C:TT-GG-II-CC(1121/1121)(26%) and combination D:TT-GG-DI-CT(1121/1112)(22%).(3) The frequencies of the above mentioned SNP in single or in combinations were not different significantly between NGT and T2DM groups. (4) The variation of clinical metabolic parameter levels shifted from completely normal towards abnormal glucose intolerance among genotype combination subgroups. In comparison between combination A and combination D, subjects in the former subgroups had: higher PG levels with delayed peak after glucose challenge; less and lower decrement of FFA levels after challenge with no rising in late stage; higher insulin levels with delayed peak after challenge; and the tendency of decreased insulin sensitivity. More than half of the comparisons remained statistically significant after adjusted with age, gender, body mass index and waist circumference.

CONCLUSION

The variation of calpain-10 gene has impact on the variation of clinical metabolic parameter levels related to type 2 diabetes mellitus. Such impact depends upon the haplotypes as well as the haplotype combination of calpain-10 gene variations.

Airway inflammation and remodeling in asthma. Lessons from interleukin 11 and interleukin 13 transgenic mice

Noninflammatory structural alterations, variously referred to as airway remodeling, are well documented in the asthmatic airway. However, the pathogenesis of these alterations, the importance of airway remodeling in generating the asthma phenotype, and the natural history of airway remodeling responses have not been adequately defined. Because exaggerated cytokine production is a characteristic feature of the asthmatic airway, we used constitutive and inducible overexpression transgenic systems to investigate the contributions that interleukin 11 (IL-11) and IL-13 might make to airway remodeling responses. These studies demonstrated that both cytokines produce responses in the murine airway with features similar to those in human asthmatic tissues. IL-11 caused airway fibrosis with the enhanced accumulation of interstitial collagens, myocytes, and myofibroblasts. IL-13 caused mucous metaplasia, enhanced mucin gene expression, enhanced tissue hyaluronic acid accumulation, and subepithelial fibrosis. Importantly, IL-11 was detected most readily in tissues from asthmatic subjects with severe airway remodeling that was similar to that seen in the IL-11 transgenic mice. In addition, IL-11 was shown to inhibit asthma-like inflammation while stimulating airway fibrosis. This suggests that IL-11 elaboration is, in part, an attempt at airway healing. Last, a novel triple transgenic system is described that allows transgene expression to be regulated in a true "on/off" manner. This system may be useful in defining the reversibility of transgene-induced airway remodeling responses.

IL-11: insights in asthma from overexpression transgenic modeling

The evolution of our understanding of IL-11 mirrors, in many ways, the problems that are faced by investigators in the post-genome era and the types of techniques that might need to be used to deal with these issues. IL-11 was discovered as a soluble factor in fibroblast supernatants that stimulated the proliferation of "IL-6-dependent" plasmacytoma cells. It was subsequently demonstrated to be an important stimulator of platelet reconstitution and a pleiotropic regulator of nonrespiratory tissues. In the lung, IL-11 is produced by a variety of structural cells and eosinophils in response to a variety of stimuli, including TGF-beta, major basic proteins, and viruses. IL-11 is also detected in exaggerated quantities at sites of virus infection. Its potential effector functions at these sites were defined with constitutive and inducible overexpression transgenic modeling systems which demonstrated that IL-11 causes nodular mononuclear infiltrates, airway remodeling with subepithelial fibrosis, airways obstruction, and airways hyperresponsiveness and can block alveolar development when expressed during development. In accord with these murine findings, IL-11 is selectively expressed in eosinophils and epithelial cells in patients with moderate and severe asthma where expression correlates directly with disease severity and inversely with FEV(1). Studies using transgenic mice also demonstrated that IL-11 inhibits antigen-induced tissue inflammation. Thus IL-11 might be an important regulator of inflammatory and remodeling responses in the asthmatic airway.

Importance of magnesium ions in development of tolerance to ethanol: studies on cultured cerebral vascular smooth muscle cells, type-2 astrocytes and intact rat brain

This study was designed to examine the roles of intracellular free magnesium ion concentration ([Mg(2+)](i)) in ethanol-induced intoxication and development of tolerance in cultured canine cerebral vascular smooth muscle cells and astrocytes as well as intact rat brain. The basal, resting level of [Mg(2+)](i) in cerebrovascular cells was 732.5 +/- 82.4 microM. Exposure of cultured canine cerebral vascular smooth muscle cells to ethanol (10 and 25 mM) for 24 h reduced the concentrations of [Mg(2+)](i) to 521.1 +/- 59.6 microM, and 308.2 +/- 37.8 microM, respectively. However, exposure of these cultured vascular cells to the same concentrations of ethanol, after initial pretreatment with ethanol for 24 h, failed to interfere with the levels of [Mg(2+)](i). Measurement of [Mg(2+)](i) at 48 h and 72 h indicated that the decreased levels of [Mg(2+)](i) induced by ethanol at 24 h treatment returned toward baseline. Similar experiments were performed in cultured type-2 astrocytes isolated from neonatal rat brain. The basal level of [Mg(2+)](i) in type-2 astrocytes was about 125 microM. Incubation of these cells with 10 mM ethanol for 10 min resulted in a 27% reduction in the level of [Mg(2+)](i), whereas incubation with 25 mM ethanol resulted in almost a 50% reduction in [Mg(2+)](i). The decreased levels of [Mg(2+)](i) lasted around 30 min, until the measurement finished. Continuous incubation of these cultured astrocytes, with ethanol (either 10 mM or 25 mM), for more than 24 h, indicated that the concentrations of [Mg(2+)](i) in type-2 astrocytes were equivalent to those at basal, resting levels. In vivo 31P-NMR spectroscopy, performed on intact rat brains, indicated that an initial administration of 4 mg/kg ethanol ( approximately 20-25 mM blood alcohol level) resulted (after 20-40 min of exposure) in severe deficits in whole brain [Mg(2+)](i) (550 +/- 33 microM to 358 +/- 24 microM). Repeated injections of ethanol (4 mg/kg) over the next 24-72 h resulted in progressively diminishing effects on brain [Mg(2+)](i). These experimental data indicate that chronic ethanol treatment can induce a tolerance to depletion of [Mg(2+)](i) in cerebrovascular smooth muscle cells, type-2 astrocytes as well as intact rat brain. The results suggest that [Mg(2+)](i) might play a major role in alcohol-induced tolerance in the brain.

Vascular endothelial growth factor (VEGF) is an autocrine growth factor for VEGF receptor-positive human tumors

Angiogenesis is required for the progression of tumors from a benign to a malignant phenotype and for metastasis. Malignant tumor cells secrete factors such as vascular endothelial growth factor (VEGF), which bind to their cognate receptors on endothelial cells to induce angiogenesis. Here it is shown that several tumor types express VEGF receptors (VEGFRs) and that inhibition of VEGF (VEGF antisense oligonucleotide AS-3) or VEGFRs (neutralizing antibodies) inhibited the proliferation of these cell lines in vitro. Furthermore, this effect was abrogated by exogenous VEGF. Thus, VEGF is an autocrine growth factor for tumor cell lines that express VEGFRs. A modified form of VEGF AS-3 (AS-3m), in which flanking 4 nucleotides were substituted with 2-O-methylnucleosides (mixed backbone oligonucleotides), retained specificity and was active when given orally or systemically in vitro and in murine tumor models. In VEGFR-2-expressing tumors, VEGF inhibition may have dual functions: direct inhibition of tumor cell growth and inhibition of angiogenesis.

Interleukin 8 is an autocrine growth factor and a surrogate marker for Kaposi's sarcoma

Kaposi's sarcoma (KS) is the most common tumor associated with HIV-1 infection. Here, we report the expression, regulation, and biological effect of interleukin (IL)-8 in KS. AIDS-KS cell lines expressed higher levels of IL-8 than either human umbilical vein endothelial cells (HUVECs), human aortic smooth muscle (AoSM) cells or fibroblast cells (T1). The inflammatory cytokine IL-1beta up-regulated IL-8 expression in a time- and concentration-dependent manner in KS cell lines. IL-8 antisense oligonucleotides specifically reduced IL-8 mRNA and protein levels and inhibited KS cell growth in a dose-dependent manner. In addition, supernatant from a KS cell line induced the growth of HUVECs and angiogenesis in chicken chorioallantoic membrane assays, both of which were inhibited by IL-8 neutralizing antibody. Serum levels of IL-8 were also elevated in KS cases compared with matched controls. Modulation of IL-8 may thus be of therapeutic value in this disease.

Use of the tetracycline-controlled transcriptional silencer (tTS) to eliminate transgene leak in inducible overexpression transgenic mice

The doxycycline-inducible reverse tetracycline transactivator (rtTA) is frequently used to overexpress transgenes in a temporally regulated fashion in vivo. These systems are, however, often limited by the levels of transgene expression in the absence of dox administration. The tetracycline-controlled transcriptional silencer (tTS), a fusion protein containing the tet repressor and the KRAB-AB domain of the kid-1 transcriptional repressor, is inhibited by doxycycline. We hypothesized that tTS would tighten control of transgene expression in rtTA-based systems. To test this hypothesis we generated mice in which the CC10 promoter targeted tTS to the lung, bred these mice with CC10-rtTA-interleukin 13 (IL-13) mice in which IL-13 was overexpressed in an inducible lung-specific fashion, and compared the IL-13 production and phenotypes of parental mice and the triple transgenic CC10-rtTA/tTS-IL-13 progeny of these crosses. In the CC10-rtTA-IL-13 mice, IL-13, mucus metaplasia, inflammation, alveolar enlargement, and enhanced lung volumes were noted at base line and increased greatly after doxycycline administration. In the triple transgenic tTS animals, IL-13 and the IL-13-induced phenotype could not be appreciated without doxycycline. In contrast, tTS did not alter the induction of IL-13 or the generation of the IL-13 phenotype by doxycycline. Thus, tTS effectively eliminated the baseline leak without altering the inducibility of rtTA-regulated transgenes in vivo. Optimal "off/on" regulation of transgene expression can be accomplished with the combined use of tTS and rtTA.

Agricultural exposure to carbamate pesticides and risk of non-Hodgkin lymphoma

Recent epidemiological studies have suggested an increased risk of non-Hodgkin lymphoma (NHL) from carbamate insecticide use among farmers. To further explore the possible relationships, we conducted a pooled analysis of three population-based case-control studies conducted in four midwestern states in the United States. A total of 985 white male subjects and 2895 control subjects were included in this analysis. Unconditional logistic regression was used to estimate the association and control for confounding. Compared with nonfarmers, farmers who had ever used carbamate pesticides had a 30% to 50% increased risk of NHL, whereas farmers without carbamate pesticide use showed no increased risk. Analyses for individual carbamate pesticides found a more consistent association with Sevin but not carbofuran, butylate, or S-ethyl dipropylthiocarbamate plus protectant. Among farmers using Sevin, the risk of NHL was limited to those who personally handled the product, those who first used the product for > or = 20 years before their disease diagnosis, and those who used the product for a longer period. These associations persisted after adjusting for other major classes of pesticides. These results suggest an increased risk of NHL associated with carbamate pesticide use, particularly Sevin. Further investigation of the association is warranted.

Occupation and leukemia: a population-based case-control study in Iowa and Minnesota

BACKGROUND

Studies have suggested that risk of leukemia may be associated with occupational or industrial exposures and risk may vary by the histological type of the disease.

METHODS

A population-based case-control study was conducted in Iowa and Minnesota to evaluate the association between various occupations, industries, and occupational exposures and leukemia risk. A total of 513 cases and 1,087 controls was included in the study. A lifetime occupational history and other risk factor information were collected through in-person interviews, and a job-exposure matrix was used to assess possible risks associated with specific exposures.

RESULTS

A significantly increased risk of leukemia was observed among agricultural service industries and among nursing and healthcare workers. Janitors, cleaners, and light truck drivers also experienced increased risk. Those employed in plumbing, heating and air conditioning industries, and sales of nondurable goods (such as paints and varnishes) had an increased risk. Printers, painters, and workers in the food and metal industries had a nonsignificantly increased risk of leukemia. Analyses by specific exposures and histology of leukemia showed that risk of leukemia associated with occupational or industrial exposures may vary by histological type of the disease.

CONCLUSIONS

An increased risk of leukemia among workers employed in agricultural industries, nursing and healthcare workers, and in a few occupations with possible exposure to solvents is consistent with earlier studies. Associations of risk with occupations not observed previously deserve further assessment. Published 2001 Wiley-Liss, Inc.

Antioxidants prevent depletion of [Mg2+]i induced by alcohol in cultured canine cerebral vascular smooth muscle cells: possible relationship to alcohol-induced stroke

Low serum concentrations of Mg(2+) ions have been reported, recently, in patients with coronary disease, atherosclerosis, and stroke as well as in patients with cerebral hemorrhage. The aim of the present study was to determine whether potent antioxidants [alpha-tocopherol and pyrrolidine dithiocarbamate (PDTC)] can prevent or ameliorate intracellular Mg(2+) ([Mg(2+)](i)) depletion associated with cerebral vascular injury induced by alcohol. Exposure of cultured canine cerebral vascular smooth muscle cells to alcohol (10-100 mM) for 24 h induced marked depletion in [Mg(2+)](i) (i.e., approximately 30-65%, depending upon alcohol concentration). Treatment of the cultured cells with either PDTC (0.1 microM) or alpha-tocopherol (15 microM) for 24 h, alone, failed to interfere with basal [Mg(2+)](i) levels. However, preincubation of the cells with either alpha-tocopherol or PDTC for 24 h completely inhibited the depletion of [Mg(2+)](i) induced by exposure to 10-100 mM ethanol. These results indicate that alpha-tocopherol and PDTC prevent decreases in [Mg(2+)](i) produced by ethanol. Moreover, these new results suggest that such protective effects of alpha-tocopherol and PDTC on cerebral vascular cells might be useful therapeutic tools in prevention and amelioration of cerebral vascular injury and stroke in alcoholics.

Importance of extracellular Ca2+ and intracellular Ca2+ release in ethanol-induced contraction of cerebral arterial smooth muscle

The present study was designed to investigate the roles of extracellular Ca2+ ([Ca2+]0) influx and intracellular free Ca2+ ([Ca2+]i) release in ethanol-induced contractions of isolated canine cerebral arteries and primary cultured, cerebral vascular smooth muscle cells. Ethanol (20-200 mM) produced significant contractions in isolated canine basilar arterial rings in a concentration-dependent manner. Removal of [Ca2+]0 and pretreatment of canine basilar arterial rings with verapamil (an antagonist of voltage-gated Ca2+ channels), thapsigargin (a selective antagonist of the sarcoplasmic reticulum Ca2+ pump), caffeine plus ryanodine (a specific antagonist of ryanodine-sensitive Ca2+ release), or heparin (an inositol 1,4,5,-trisphosphate [InsP3]-mediated Ca2+ release antagonist) markedly attenuated (approximately 50%-80%) ethanol-induced contractions. The absence of [Ca2+]0 and preincubation of primary single smooth muscle cells obtained from canine basilar arteries with verapamil, thapsigargin, heparin, or caffeine plus ryanodine markedly attenuated (approximately 50%-80%) the transient and sustained elevations in [Ca2+]i induced by ethanol. Results of the present study suggest to us that both Ca2+ influx through voltage-gated Ca2+ channels and Ca2+ release from intracellular stores (both InsP3 sensitive and ryanodine sensitive) are required for ethanol-induced contractions of isolated canine basilar arteries.