Isolation of Aspergillus fumigatus from sputum is associated with elevated airborne levels in homes of patients with asthma.

Indoor bioaerosols, such as mold spores, have been associated with respiratory symptoms in patients with asthma; however, dose-response relationships and guidelines on acceptable levels are lacking. Furthermore, a causal link between mold exposure and respiratory infections or asthma remains to be established. The aim of this study was to determine indoor concentrations of Aspergillus fumigatus and a subset of clinically relevant fungi in homes of people with asthma, in relation to markers of airways colonization and sensitization. Air and dust samples were collected from the living room of 58 properties. Fungal concentrations were quantified using mold-specific quantitative PCR and compared with traditional microscopic analysis of air samples. Isolation of A. fumigatus from sputum was associated with higher airborne concentrations of the fungus in patient homes (P = 0.04), and a similar trend was shown with Aspergillus/Penicillium-type concentrations analyzed by microscopy (P = 0.058). No association was found between airborne levels of A. fumigatus and sensitization to this fungus, or dustborne levels of A. fumigatus and either isolation from sputum or sensitization. The results of this study suggest that the home environment should be considered as a potential source of fungal exposure, and elevated home levels may predispose people with asthma to airways colonization.

Mitochondrial dysfunction triggered by loss of HtrA2 results in the activation of a brain-specific transcriptional stress response.

Cellular stress responses can be activated following functional defects in organelles such as mitochondria and the endoplasmic reticulum. Mitochondrial dysfunction caused by loss of the serine protease HtrA2 leads to a progressive movement disorder in mice and has been linked to parkinsonian neurodegeneration in humans. Here, we demonstrate that loss of HtrA2 results in transcriptional upregulation of nuclear genes characteristic of the integrated stress response, including the transcription factor CHOP, selectively in the brain. We also show that loss of HtrA2 results in the accumulation of unfolded proteins in the mitochondria, defective mitochondrial respiration and enhanced production of reactive oxygen species that contribute to the induction of CHOP expression and to neuronal cell death. CHOP expression is also significantly increased in Parkinson's disease patients' brain tissue. We therefore propose that this brain-specific transcriptional response to stress may be important in the advance of neurodegenerative diseases.

Evaluation of the cancer chemopreventive efficacy of rice bran in genetic mouse models of breast, prostate and intestinal carcinogenesis.

Brown rice is a staple dietary constituent in Asia, whereas rice consumed in the Western world is generally white, obtained from brown rice by removal of the bran. We tested the hypothesis that rice bran interferes with development of tumours in TAg, TRansgenic Adenocarcinoma of the Mouse Prostate (TRAMP) or Apc(Min) mice, genetic models of mammary, prostate and intestinal carcinogenesis, respectively. Mice received rice bran (30%) in AIN-93G diet throughout their post-weaning lifespan. In TAg and TRAMP mice, rice bran did not affect carcinoma development. In TRAMP or wild-type C57Bl6/J mice, dietary rice bran increased kidney weight by 18 and 20%, respectively. Consumption of rice bran reduced numbers of intestinal adenomas in Apc(Min) mice by 51% (P<0.01), compared to mice on control diet. In parallel, dietary rice bran decreased intestinal haemorrhage in these mice, as reflected by increased haematocrit. At 10% in the diet, rice bran did not significantly retard Apc(Min) adenoma development. Likewise, low-fibre rice bran (30% in the diet) did not affect intestinal carcinogenesis, suggesting that the fibrous constituents of the bran mediate chemopreventive efficacy. The results suggest that rice bran might be beneficially evaluated as a putative chemopreventive intervention in humans with intestinal polyps.

Second-hand smoke levels in UK pubs and bars: do the English Public Health White Paper proposals go far enough?

BACKGROUND: The English Public Health White Paper proposes introducing smoke-free workplaces except in pubs and bars that do not prepare and serve food. The bar area will be non-smoking in exempted pubs. OBJECTIVE: To explore the likely impact of these proposals in UK pubs and bars. METHODS: A total of 59 pubs and bars within Greater Manchester in 2001 were chosen. Thirteen were mechanically ventilated, 12 were naturally ventilated and 34 had extractor fans; 23 provided non-smoking areas. We measured time-weighted average concentrations of respirable suspended particles (RSP), solanesol tobacco-specific particles and vapour-phase nicotine (VPN) over a 4-h sampling period on a Tuesday or Saturday night. RESULTS: Second-hand smoke (SHS) levels in smoking areas were high (mean RSP 114.5 microg/m3, VPN 88.2 microg/m3, solanesol 101.7 microg/m3). There were only small (5-13 per cent) reductions in bar areas. Mean levels were lower in non-smoking areas: by 33 per cent for RSPs, 52 per cent for solanesol particles and 69 per cent for VPN. Compared with other settings (homes and other workplaces) with unrestricted smoking, mean SHS levels were high throughout all areas of the pubs regardless of ventilation strategy. CONCLUSION: Partial measures, like those in the English Public Health White Paper, will leave bar staff in exempted pubs unprotected from the occupational hazard of SHS.

Comparison of the effect of oestradiol, tamoxifen and raloxifene on nerve growth factor-alpha expression in specific neonatal mouse uterine cell types using laser capture microdissection.

Oral dosing of CD-1 mice on days 2-5 after birth with tamoxifen but not raloxifene disrupts the development of the myometrium, resulting in adult uterine adenomyosis. Using laser capture microdissection and RT-PCR we have investigated nerve growth factor (NGF) and cognate receptor expression in uterine cells of 6-day-old pups that may be important in early developmental changes that give rise to adenomyosis. NGF down-regulation is known to occur during terminal myogenic differentiation. NGF was found exclusively in endometrial luminal epithelium of controls. It was up-regulated 18-fold in the luminal epithelium following dosing with tamoxifen but not raloxifene. Western blotting for NGF protein in the whole uterus showed a 25-fold increase after tamoxifen treatment. Expression of the low affinity p75 neutrophin receptor (p75(NTR)) was twofold higher in the myometrium compared with luminal epithelium or stroma. This was not altered following tamoxifen treatment. There was no detectable expression of high affinity tyrosine kinase receptor (trkA(NGFR)). This study shows luminal epithelial cells of the endometrium primarily form NGF. This suggests that NGF normally regulates the differentiation of the mesenchyme into uterine myocytes through paracrine mechanisms and that an early disturbance of this process plays a key role in the subsequent development of adenomyosis.

Cumulative exposure to tamoxifen: DNA adducts and liver cancer in the rat.

Tamoxifen is a potent rat liver carcinogen, currently being used as a long-term chemopreventative for breast cancer in healthy women. The mechanism by which tamoxifen causes liver cancer in rats is known to be associated with the accumulation of tamoxifen DNA adducts in this organ. We have examined the dose-response relationship of tamoxifen-induced DNA adducts in the liver and the subsequent increase in the development of liver cancer, with and without phenobarbital promotion. Female Wistar (Han) rats were fed 420 ppm tamoxifen in the diet for 0, 1, 4, 8 or 12 weeks after which time rats were either examined immediately for hepatic tamoxifen-induced DNA damage using the 32P-Postlabelling assay, or left for lifetime for tumour assessment. A proportion of rats left for lifetime study were given phenobarbital in their drinking water. There was a clear dose-response relationship with respect to duration of tamoxifen exposure for both accumulation of DNA adducts and lifetime risk of liver cancer. In the absence of phenobarbital promotion there was a threshold value for tamoxifen-induced DNA adducts (180 adducts/10(8) nucleotides) and the subsequent induction of liver cancer. This study demonstrates the relationship between the accumulation of hepatic tamoxifen-induced DNA adducts and the development of liver cancer and establishes the threshold for hepatocarcinogenesis in terms of DNA adduct formation. These data could provide useful information in interpreting the relevance of low levels of DNA adducts in humans.

Use of the Nd-YAG laser improves quality of life and economic factors in the treatment of hemorrhoids.

PURPOSE: Hemorrhoidal disease may benefit from the use of Nd-YAG laser to decrease surgical recovery time, postoperative hospital stay and complications. METHODS: Fifty patient charts from 1993 to 1998 were reviewed retrospectively to evaluate postoperative complications and overall patient satisfaction following hemorrhoidectomy. We used the Nd-YAG laser from Surgical Laser Technologies CL60 with the ERP4 sapphire tip and the setting of 20 watts on continuous wave mode. Coagulation posthemorrhoidal excision of the remaining tissue was done using 60 watts pulse wave setting of 0.3 seconds. RESULTS: Laser treated hemorrhoidectomy patients experienced less pain than the standard hemorrhoidectomy patients. One week after surgery, the laser treated patients had 65% less pain than the standard hemorrhoidectomy patients. Painless defecation occurred earlier in the laser treated patients by five days and postoperative drainage was less than standard surgically treated patient. Surgical and hospital costs were lower by 27% and 11% respectively in the laser treated group. 88% of the laser treated patients vs 44% of the standard patients resumed work at one week after surgery. CONCLUSIONS: Nd-YAG laser treated hemorrhoid surgery patients had a quicker recovery and earlier return to work.

Tamoxifen induces endometrial and vaginal cancer in rats in the absence of endometrial hyperplasia.

Tamoxifen was administered orally to neonatal rats on days 2-5 after birth and the subsequent effects on the uterus were characterized, morphometrically, over the following 12 months. Tamoxifen inhibited development of the uterus and glands in the endometrium, indicating a classical oestrogen antagonist action. Between 24 and 35 months after tamoxifen treatment there was a significant increase in the incidence (26%) of uterine adenocarcinomas and a 9% incidence of squamous cell carcinomas of the vagina/cervix in the absence of any oestrogen agonist effect in the uterus. This demonstrates that an oestrogen agonist effect is not an absolute requirement for the carcinogenic effect of tamoxifen in the reproductive tract of the rat. The unopposed oestrogen agonist effect of tamoxifen on the endometrium may not be the only factor involved in the development of endometrial cancers. It is possible that tamoxifen causes these tumours via a genotoxic mechanism similar to that seen in rat liver. However, using (32)P-post-labelling we failed to find evidence of tamoxifen-induced DNA adducts in the uterus. Tamoxifen may affect hormonal imprinting of oestrogen receptor responses in stem cells of the uterus, causing reproductive tract cancers to arise at a later time, in the same way as has been proposed for diethylstilbestrol. If these rodent data extrapolate to humans, then women who are taking tamoxifen as a chemopreventative may have an increased risk of vaginal/cervical cancer, as well as endometrial cancer.

Uterotrophic effects of tamoxifen, toremifene, and raloxifene do not predict endometrial cell proliferation in the ovariectomized CD1 mouse.

The uterotrophic responses of ovariectomized CD1 mice to tamoxifen, toremifene, and raloxifene have been compared to 17beta-estradiol after a treatment period of 72 h. Uterine and vaginal weight, luminal epithelial thickening, and 5-bromodeoxyuridine (BrdU) labeling index in the endometrial stroma were examined. All three pharmaceuticals, as well as 17beta-estradiol, produced increases in the classic estrogen-dependent variables of uterine and vaginal weights after the 3-day treatment period. Tamoxifen, toremifene, raloxifene, and estradiol all increased luminal epithelial thickness, and increased the BrdU labeling index in the endometrial stroma of the uterus. Although the dose response for the uterotrophic effect and the vaginal weight increases for toremifene differed from tamoxifen and raloxifene, in that there was no dose at which these effects were maximal, the stimulation of BrdU labeling index in the endometrial stroma was dose dependent and very similar for all three, at the clinically relevant doses. Treatment-related hypertrophic effects were estimated by examination of the nuclear profile density in the endometrial stroma. Estradiol and tamoxifen caused a greater hypertrophic effect than toremifene and raloxifene, indicating that factors other than an increase in cell number contribute to the overall uterotrophic effect. This demonstrates that the use of uterine weight to estimate the relative estrogenicity of drugs could give a misleading impression of the response of the uterus to estrogen agonists. Variables, such as increased DNA replication, which may be more important to a subsequent potential carcinogenic process in the uterus, for a particular drug, requires separate evaluation.

Compartmentalized uterotrophic effects of tamoxifen, toremifene, and estradiol in the ovariectomized Wistar (Han) rat.

The comparative uterotrophic responses of ovariectomized Wistar (Han) rats to tamoxifen, toremifene, and 17beta-estradiol have been determined over a period of 72 h. Uterine wet weight; luminal epithelial cell hypertrophy; and BrdU labeling index in the different tissue compartments of the uterus, and the immunohistochemical expression of nuclear estrogen receptor alpha (nERalpha), and nuclear progesterone receptor (nPR) were examined. Luminal epithelial cell hypertrophy was produced by all three compounds to a similar degree. 17beta-Estradiol produced an increase in uterine wet weight due to fluid imbibition over the 3-day period, and an increase in DNA synthesis in the endometrial stromal and myometrial compartments of the uterus, as measured by increased BrdU incorporation. Estradiol increased the expression of nERalpha and nPR in the myometrium with time and decreased nERalpha levels from the overexpressed levels in control ovariectomized rat luminal epithelial cells. Tamoxifen and toremifene caused a smaller increase in uterine weight and the BrdU labeling index in the endometrial stroma and myometrium than did estradiol, and they increased the expression of nERalpha and nPR in the myometrium. Tamoxifen and toremifene differed from estradiol in that they did not decrease the expression of nERalpha in the luminal epithelial cells of the uterus. The response of PR expression was the same for tamoxifen, toremifene, and estradiol, and was therefore considered to be the most reliable indication of an estrogen-agonist effect in this study. The ability to distinguish differential, compartmentalized effects for agonists of estrogen action in the uterus will allow a better risk assessment for new pharmaceuticals that are used as breast cancer chemotherapeutic agents, especially where their use may also be associated with an increased risk of uterine cancers, in particular.

The quantitative distinction of hyperplasia from hypertrophy in hepatomegaly induced in the rat liver by phenobarbital.

A histological method utilizing the optical dissector principle has been developed for determining the absolute numbers of rat hepatocytes in the liver after treatment with phenobarbital (PB). The optical dissector is a technique derived from the "new stereology" used to measure the number of features, in this case hepatocyte nuclear profiles, that are present in a reference volume of tissue. The method has been applied to distinguish between the hepatomegaly that commonly occurs in rodents after treatment with chemicals, due to an increase in the number of cells caused by cell division (hyperplasia), rather than the size of cells (hypertrophy). In the case of PB treatment, the hepatomegaly was found to be partly due to hypertrophy and partly to hyperplasia after 2 weeks of treatment. While the increase in the absolute number of hepatocytes was not significant after 2 weeks, after 12 weeks of treatment with PB the number of hepatocytes was significantly increased, compared to the controls at that time point. PCNA labeling index measurements of liver hepatocytes confirmed that there was a significant increase in the growth fraction of hepatocytes during PB treatment. The induction of hyperplasia can be associated with an increased risk of eventual liver tumor formation, and the distinction of hyperplasia from hypertrophy, using a purely histological method, for the determination of increases in absolute hepatocyte cell numbers, will be useful in assessing whether treatment-related sustained hyperplasia is occurring in the liver, although this methodology could be applied to any organ.

New approaches to the quantitation of hypertrophy and hyperplasia in hepatomegaly.

A histological method utilizing the optical dissector principle has been developed for determining the contribution of hypertrophy and hyperplasia to the hepatomegaly induced by the peroxisome proliferator gemfibrozil. The optical dissector is a technique derived from the 'new stereology' and has been used to estimate the number of hepatocyte nuclear profiles, that are present in a reference volume of tissue. The overall changes due to hypertrophy and hyperplasia in the rat liver after gemfibrozil treatment, did not reach significance, although the zonal hypertrophy change did. This indicated that although there was a 20% increase in liver weight with treatment, the hepatomegaly was caused by a combination of hypertrophy and hyperplasia, neither of which, on its own, was significantly different from the control values. The distinction of hyperplasia from hypertrophy, using a purely histological method, will be useful in assessing whether treatment related sustained hyperplasia is occurring in the liver.

Depletion of hepatocyte nuclear estrogen receptor expression is associated with promotion of tamoxifen induced GST-P foci to tumours in rat liver.

The expression of hepatocyte nuclear estrogen receptor (ER) in putative preneoplastic foci, adenomas and carcinomas, induced by the rat liver carcinogen tamoxifen, has been examined immunohistologically. ER staining of normal rat liver shows between 30-50% of hepatocyte nuclei to be positive, depending on fixation. Depletion of ER was defined as <10% of cells in foci or tumours staining for nuclear ER. A proportion of all but the smallest glutathione-S-transferase, placental form (GST-P) expressing foci had depleted expression of nuclear ER. The percentage of GST-P expressing foci with depletion of nuclear ER increased with the size of the foci. The liver adenomas and carcinomas induced by tamoxifen showed a high incidence (90%) of depletion of ER. This suggests that abnormal expression of the ER is associated with the promotion of putative preneoplastic foci to adenomas and carcinomas in tamoxifen exposed rat livers. Dysfunction of the ER could contribute to selective continued stimulation of initiated cells that would be consistent with a role for modification of the ER in target cells and the promotion stage of liver cancer. Liver tumours induced by other carcinogens in both sexes of rat were also found to have a high incidence of ER depletion, indicating that this could be a general regulatory mechanism for rat liver tumour promotion, irrespective of the possible estrogen like action of individual carcinogens.

Thoracic epidural analgesia started after cardiopulmonary bypass. Adrenergic, cardiovascular and respiratory sequelae.

The effects of thoracic epidural analgesia started after cardiopulmonary bypass were studied on the subsequent adrenergic, cardiovascular and respiratory responses. Sixteen cardiac surgical patients received either a standardised general anaesthetic (control group) or a standardised general anaesthetic and thoracic epidural analgesia (epidural group). The epidural catheter was sited before surgery and heparinisation. Following discontinuation of cardiopulmonary bypass, patients in the epidural group were given 15 ml bupivacaine 0.5% down the catheter followed by an infusion of bupivacaine 0.375% at 5-8 ml.h-1 after surgery. The control group received an intravenous morphine infusion on completion of surgery. The adrenergic response was assessed by measuring arterial catecholamine concentrations. Respiratory function was determined by spirometry, peak expiratory flow and arterial partial pressure of oxygen while breathing air. Pain scores were also obtained. After cardiopulmonary bypass the increases in catecholamine concentrations were effectively inhibited in the epidural group for the remainder of the study (p < 0.05). Postoperative respiratory function was less impaired in the epidural group, with higher forced expiratory volume in 1 s, forced vital capacity and peak expiratory flow (p < 0.05). Pain scores were also significantly lower in the epidural group (p < 0.05). There were no significant differences in cardiovascular parameters.

Iron promotes DEN initiated GST-P foci in rat liver.

Diethylnitrosamine (DEN) was administered to rats as a single dose, which is known not to give rise to liver tumours without subsequent promotion. Iron dextran (Fe/Dex) was then administered parenterally to the animals, to induce iron overload. At 3 and 6 months after the final Fe/Dex treatments, livers were examined quantitatively for the numbers of the placental form of glutathione-S-transferase (GST-P) expressing foci, the area occupied by these foci and their size distribution. The results demonstrate that iron not only increased the number of foci after DEN initiation in the rat liver, but that the area occupied by these lesions increased significantly between 3 and 6 months after initiation. There is no evidence that iron increased the number of GST-P expressing foci present in rats not exposed to DEN. This indicates that iron did not act as an initiator in this rodent model of liver cancer. The increase in the area of the liver occupied by the foci in iron and DEN treated rats was due to an increase in the size of the foci, as well as to an increase in the number of foci. This is the first demonstration that iron can act as a promoter of DEN initiated hepatocytes. It also demonstrates that fibrogenesis is not an absolute requirement for the promotion, by iron, of liver foci in the rat, and that this could also be the case for iron overload in man. Iron may also act as a promoter of already initiated hepatocytes in the development of human liver cancer, as it does in the rat.

Method for determining whether the number of hepatocytes in rat liver is increased after treatment with the peroxisome proliferator gemfibrozil.

A histological method has been developed for determining the absolute numbers of rodent hepatocytes after treatment with the hypolipodemic drug gemfibrozil. It can be applied to distinguish between the enlargement of the liver that commonly occurs in rodents after treatment with chemicals, due to changes in the size of cells (hypertrophy), rather than an increase in the number of cells caused by cell division (hyperplasia). In the case of gemfibrozil the liver enlargement was found to be partly due to hypertrophy and partly to hyperplasia. The induction of hyperplasia can be associated with an increased risk of eventual liver tumour formation, and the distinction of hypertrophy from hyperplasia using a purely histological method, for the determination of increases in hepatocyte cell numbers, will be useful in the assessment of compounds which cause liver enlargement that could precede neoplasia.