Air contaminant exposures during the operation of lawn and garden equipment

The US Environmental Protection Agency (EPA) initiated the Small Engine Exposure Study (SEES) to evaluate potential exposures among users of small, gasoline-powered, non-road spark-ignition (SI) lawn and garden engines. Equipment tested included riding tractors, walk-behind lawn mowers, string trimmers, and chainsaws. Personal and background air quality measurements were collected on equipment operators for carbon monoxide (CO), particulate matter <or=2.5 microm in aerodynamic diameter (PM(2.5)), volatile organic compounds (VOCs), and aldehydes. PM(2.5) measurements included continuous and integrated mass, elemental and organic carbon (EC/OC), and trace metals. Aldehyde measurements included speciation for formaldehyde and acetaldehyde. The results demonstrated that equipment operators can experience elevated exposures to CO, PM(2.5) and air toxics while operating these engines. Ten-second average CO personal exposures spanned over two orders of magnitude, with short-term concentrations exceeding 120 p.p.m. for some engine applications tested. PM(2.5) concentrations averaged over each engine test period also spanned two orders of magnitude. The results also suggest that health standards, such as the CO and PM(2.5) National Ambient Air Quality Standards (NAAQS), may be exceeded for certain equipment types under certain operating scenarios. Aldehyde measurements suggested exposures from primary engine emissions that exceed typical ambient concentrations, but do not exceed occupational health standards. Continuous exposure measurements illustrated the important role of the operator's activity and environmental conditions in affecting exposure levels.

Cytokines and alcohol

Cytokines are multifunctional proteins that play a critical role in cellular communication and activation. Cytokines have been classified as being proinflammatory (T helper 1, Th1) or anti-inflammatory (T helper 2, Th2) depending on their effects on the immune system. However, cytokines impact a variety of tissues in a complex manner that regulates inflammation, cell death, and cell proliferation and migration as well as healing mechanisms. Ethanol (alcohol) is known to alter cytokine levels in a variety of tissues including plasma, lung, liver, and brain. Studies on human monocyte responses to pathogens reveal ethanol disruption of cytokine production depending upon the pathogen and duration of alcohol consumption, with multiple pathogens and chronic ethanol promoting inflammatory cytokine production. In lung, cytokine production is disrupted by ethanol exacerbating respiratory distress syndrome with greatly increased expression of transforming growth factor beta (TGFbeta). Alcoholic liver disease involves an inflammatory hepatitis and an exaggerated Th1 response with increases in tumor necrosis factor alpha (TNFalpha). Recent studies suggest that the transition from Th1 to Th2 cytokines contribute to hepatic fibrosis and cirrhosis. Cytokines affect the brain and likely contribute to changes in the central nervous system that contribute to long-term changes in behavior and neurodegeneration. Together these studies suggest that ethanol disruption of cytokines and inflammation contribute in multiple ways to a diversity of alcoholic pathologies.

Gamma-aminobutyric acid up- and downregulates insulin secretion from beta cells in concert with changes in glucose concentration

AIMS/HYPOTHESIS

The role of gamma-aminobutyric acid (GABA) and A-type GABA receptors (GABA(A)Rs) in modulating islet endocrine function has been actively investigated since the identification of GABA and GABA(A)Rs in the pancreatic islets. However, the reported effects of GABA(A)R activation on insulin secretion from islet beta cells have been controversial.

METHODS

This study examined the hypothesis that the effect of GABA on beta cell insulin secretion is dependent on glucose concentration.

RESULTS

Perforated patch-clamp recordings in INS-1 cells demonstrated that GABA, at concentrations ranging from 1 to 1,000 micromol/l, induced a transmembrane current (I(GABA)) which was sensitive to the GABA(A)R antagonist bicuculline. The current-voltage relationship revealed that I(GABA) reversed at -42+/-2.2 mV, independently of glucose concentration. Nevertheless, the glucose concentration critically controlled the membrane potential (V (M)), i.e., at low glucose (0 or 2.8 mmol/l) the endogenous V (M) of INS-1 cells was below the I(GABA) reversal potential and at high glucose (16.7 or 28 mmol/l), the endogenous V (M) of INS-1 cells was above the I(GABA) reversal potential. Therefore, GABA dose-dependently induced membrane depolarisation at a low glucose concentration, but hyperpolarisation at a high glucose concentration. Consistent with electrophysiological findings, insulin secretion assays demonstrated that at 2.8 mmol/l glucose, GABA increased insulin secretion in a dose-dependent fashion (p<0.05, n=7). This enhancement was blocked by bicuculline (p<0.05, n=4). In contrast, in the presence of 28 mmol/l glucose, GABA suppressed the secretion of insulin (p<0.05, n=5).

CONCLUSIONS/INTERPRETATION

These findings indicate that activation of GABA(A)Rs in beta cells regulates insulin secretion in concert with changes in glucose levels.

202 IN VITRO DIFFERENTIATION OF ADULT PORCINE ADIPOSE-DERIVED STEM CELLS AFTER LABELING WITH PKH26 AND FLOW CYTOMETRY

The purpose of this study was to investigate the possible effects of the fluorescent dye PKH26 and flow cytometry on adult porcine adipose-derived stem cells (ADSCs) after exposing them to adipogenic and osteogenic differentiation conditions. Adipose tissue was isolated from swine (11 months of age) and digested with 0.075% collagenase at 37�C for 90 min. The digested adipose tissue was centrifuged at 200g for 10 min to obtain a cell pellet. The pellet was re-suspended with DMEM, and the ADSCs were plated onto 75 cm2 flasks (5000-10 000 cells per cm2) and cultured in DMEM supplemented with 10% fetal bovine serum (FBS) and 1% gentamicin. Passage 3 cells were labeled with fluorescent dye (PKH26 red fluorescent cell linker kit; Sigma Chemical, St. Louis, MO, USA) and sorted by flow cytometry. After labeling and sorting, the sorted and unsorted (control group) cells were replated and exposed to adipogenic (1 �M dexamethasone, 0.5 mM isobutylmethylxantine, 10 �M insulin and 200�M indomethacin) and osteogenic (0.1 �M dexamethasone, 10 mM �-glycerophosphate, and 50�M ascorbic acid) differentiation conditions when the cells were 90% confluent. Cells were evaluated based on morphology and specific staining properties. Adipogenic differentiation was confirmed by oil red O-positive staining of large lipid vacuoles, and osteogenic differentiation by Von Kossa staining 2 weeks after initiation of differentiation. The frequency of oil red O-positive colonies in both sorted and unsorted group was similar (15.0% vs. 13.2%, respectively). The number of osteogenic nodules, confirmed by the presence of calcium by Von Kossa staining, in the sorted and unsorted group was 17 and 184 per flask, respectively. In conclusion, this study demonstrates that adult porcine adipose-derived stem cells maintain their differentiation potential after labeling with fluorescent dye and sorting by flow cytometry. This should allow for more rapid evaluation of the differentiation potential of ADSCs in vitro. This work was partially supported by the Council for Food and Agricultural Research (C-FAR) Sentinel Program, University of Illinois and CNPq, Brazil (M. Mello).

193 EVALUATION OF A NOVEL ELECTRONIC ESTRUS DETECTION DEVICE IN RECIPIENTS SYNCHRONIZED FOR EMBRYO TRANSFER

The ability to detect estrus in cattle is an important aspect for both successful artificial insemination (AI) and successful embryo transfer (ET). The use of estrus detection devices has allowed producers to more precisely determine when to breed their cattle. There have been many types of devices including chin-ball marking harnesses, dye patches, and even electronic devices that monitor the animal's activity. With the growing popularity in timed AI and ET, these devices have again become of great interest. The latest tool for estrus detection is the multi-use TattleTale" Heat Detector (Microdyne Co., LLC., St. Joseph, MO, USA). The TattleTale" is an electronic device that is placed in a patch and affixed to the tail head. It is activated by a 3-s mount with subsequent mounts recorded per h through 12 h. Twelve hours after activation the device flashes indicating that the animal is ready for breeding. Such devices may allow breeders to determine exactly when estrus began as well as identify the peak estrus period, resulting in more accurate determination of optimal time for AI or ET. The objective of this study was to compare the accuracy of estrus detection devices when analyzing detection records and pregnancy rates. Cows from the Dixon Springs Agricultural Center (Simpson, IL, USA) were randomly separated into two groups based on estrus detection devices, one group receiving Kamar� patches (Kamor, Inc., Steamboat Springs, CO, USA) and the other receiving TattleTales. Both groups were synchronized using the OvSynch protocol (Syntex, Buenos Aires, Argentina). Cows were checked twice each day for four consecutive days, with a fifth day occurring a week later when the embryos were transferred. Estrus results were analyzed using a PROC UNIVARITE and GLM analyses with differences between treatment means determined by the LSD method of SAS (SAS Institute, Inc., Cary, NC, USA). The TattleTale detected a higher percentage (P < 0.05) of the cows in estrus (92 vs. 70%) than the Kamar� patch. Further, the TattleTale detected more asynchronous recipients (in estrus >48 h before expected) and synchronous recipients (in estrus <24 h than expected), although not significant with this sample size. In the present study, the TattleTale was more accurate in detecting estrus (i.e. fewer pregnancies were observed without estrus detected). Using the TattleTale information, a breeder would be able detect more animals in estrus and determine the most accurate time to breed or transfer embryos. Practically, the use of estrus detection devices in combination with timed AI and ET could allow for the exclusion of animals not in estrus in the optimal time windows for AI or ET, thus saving valuable semen and embryos that would be otherwise wasted on asynchronous females. The advantages of this device to producers include improved pregnancy rates based on timed breeding, lower herd management costs due to reduced quantities of wasted semen or embryos and fewer cows being resynchronized. This device also records any mounting activity missed by visual observation alone. This work was supported by USDA RRF W-1171.

125 ISOLATION OF MULTILINEAGE STEM CELLS FROM THE PORCINE MAMMARY FAT PAD

Porcine mammary tissue is a dynamic system that undergoes multiple cycles of growth, differentiation, and regression during the life cycle of a female; however, the mechanisms of mammary morphogenesis are not fully understood. The current hypothesis suggests that epithelial stem cells in the terminal end buds interact with surrounding epithelial and stromal cells during mammary tissue development and regeneration. Because the mammary gland of the virgin animal consists largely of a pad of adipose tissue, we propose that adipose-derived stem cells from the mammary fat pad (MFP) may also play a role in the regeneration process. Therefore, the objective of this experiment was to determine whether multilineage stem cells are present in the MFP of gilts. Adipose tissue from the MFP and back fat (BF) from the loin region were harvested from six nulliparous, cycling Yorkshire gilts, approximately 16 mo of age. Methods for isolation of adipose-derived stem cells were modified from those of Malusky and Wheeler (2004; International Society for Stem Cell Research, Proceedings 2nd Annual Meeting, abstr. 248:124). Presumptive stem cells isolated from each tissue type were maintained in vitro in DMEM supplemented with either 10% newborn calf serum (NCS; Rep 1 and 2) or 10% fetal calf serum (Rep 3). BF and MFP cell types formed colonies of fibroblast-like cells within 3 to 5 d. Growth characteristics are shown in Table 1. When the cells were 80% confluent, they were trypsinized and reseeded into 75-cm2 flasks. When cultured in the presence of NCS, both cell types had a progressive decrease in viability, and these cultures could not be maintained past Passage 4. Differentiation of both cell types (Passage 1) into adipogenic, myogenic, and osteogenic lineages are currently underway. Based on morphological evaluations, both cell types are able to differentiate into the aforementioned lineages; however, differentiation of MFP-derived cells occurred at a slower rate and was less pronounced than that of BF-derived cells. These preliminary findings suggest that the MFP likely contains a population of multipotent stem cells; however, at this time, it is not possible to make meaningful statistical comparisons. Further experiments are needed to fully characterize these cells and determine their role in mammary gland morphogenesis. Table 1. Growth of porcine adipose-derived stem cells obtained from the BF or from the MFP This study was partially supported by the Council for Food and Agricultural Research (C-FAR) Sentinel Program and USDA Multistate Project (W-1171).

How useful is the monitoring of (low molecular weight) heparin therapy by anti-Xa assay? A laboratory perspective

We have conducted a series of laboratory-based surveys to assess variability in assay results utilized to monitor heparin anticoagulant therapy. These surveys involved laboratories participating in the Haematology component of the Royal College of Pathologists of Australasia Quality Assurance Program (RCPA QAP). Thirty five of 646 laboratories that were sent a preliminary questionnaire indicated that they performed anti-Xa assays and these laboratories were sent a panel of four plasma samples. These plasma samples contained respectively: (i) no added heparin, (ii) low molecular weight heparin (LMWH), enoxaparin, added to a level of approximately .5 U/mL, (iii) unfractionated heparin added to a level of approximately .5 U/mL, and (iv) LMWH added to a level of approximately 1.0 U/mL. Tests to be performed were the activated partial thromboplastin time (APTT), the thrombin time (TT), fibrinogen, and anti-Xa. As expected, returned results for APTT and TT showed some elevation in heparinized samples while fibrinogen assays were not affected. Anti-Xa assays yielded the following results (median [range]): (i) .01 [0-.11], (ii) .43 [.33-.80], (iii) .23 [.10-.49], and (iv) .90 [.60-1.30]. Thus, although median values were close to those anticipated, there was a wide variation in returned results. In a repeat exercise a few months later laboratories were also asked about their therapeutic ranges (TRs) and provided with an additional vial of LMWH-spiked (1.0 U/mL) plasma labeled as 'heparin-standard' to be used as an assay calibrant. TRs varied substantially between laboratories, from low ranges of .2-.4 to high ranges of .8-1.2. Anti-Xa assay results were similar to those of the first survey: (median [range]): (a) repeat testing: (i) .02 [0-.28], (ii) .47 [.34-.80], (iii) .25 [.14-.58], (iv) .95 [.65-1.31]; (b) repeat testing using survey provided 'heparin-standard': (i) .02 [0-.24], (ii) .55 [.4-.83], (iii) .28 [.10-.63], (iv) 1.00 [.9-1.16]. Thus using the provided 'heparin-standard' yielded lower variability in results for LMWH. In conclusion, the high variability of anti-Xa assay results coupled with the widely variable TRs suggests that therapeutic heparin monitoring is poorly standardized, and this raises some concerns over the clinical value of such monitoring.

An international survey of current practice in the laboratory assessment of anticoagulant therapy with heparin

AIMS

We conducted a survey of laboratory practice for assessment of heparin anticoagulant therapy by participants of the Royal College of Pathologists of Australasia Quality Assurance Program (RCPA QAP).

METHODS

A questionnaire was sent to 646 laboratories enrolled in the Haematology component of the QAP, requesting details of tests used for monitoring heparin therapy.

RESULTS

Seventy laboratories (10.8%) returned results that indicated that they performed laboratory monitoring of heparin therapy. Most laboratories (69/70 = 98.6%) use the activated partial thromboplastin time (APTT) to monitor unfractionated heparin, with eight (11.4%) also using the APTT for monitoring low molecular weight (LMW) heparin. Five (7.1%) laboratories use the thrombin time (TT) test to help monitor heparin therapy and 37 (52.9%) laboratories use an anti-Xa assay to monitor heparin (either LMW or unfractionated). Normal reference ranges (NRR) for APTT differed considerably between laboratories, even those using the same reagent. Therapeutic ranges (TR) also differed considerably between laboratories, for both APTT and the anti-Xa assay. Laboratory differences in NRR and TR using the same reagents could only be partly explained by the use of different instrumentation.

CONCLUSIONS

There is a large variation in current laboratory practice relating to monitoring of heparin anticoagulant therapy. This finding is similar to that of a similar survey conducted by the RCPA QAP almost a decade ago. This study suggests that better standardisation is still required for laboratory monitoring of heparin therapy.

Reducing the use of diagnostic imaging in patients with suspected pulmonary embolism: Validation of a risk assessment strategy

OBJECTIVES

The aims of this study were to measure the: (i) effects of implementation of a new risk assessment strategy for patients with suspected pulmonary embolism (PE) on the use of imaging and D-dimer assay; (ii) negative predictive value for PE of a combination of low risk and negative D-dimer assay; and (iii) compliance of ED clinicians with the strategy.

METHODS

A non-randomized clinical trial was conducted in the ED of a 720-bed teaching hospital between November 2002 and August 2003. Study subjects with suspected PE were compared with 191 randomly selected historical controls. The risk assessment strategy of Kline et al. was disseminated and implemented.

RESULTS

The negative predictive value for PE was 99% (95% confidence interval [CI] = 97-100%) in 114 patients with low risk and negative D-dimer. There was a 21% absolute reduction in the rate of imaging following the implementation of the risk assessment strategy (56% vs 77%, P < 0.001).

CONCLUSION

Low risk combined with a negative D-dimer result may allow exclusion of PE without imaging.

Multilaboratory Testing of Thrombophilia: Current and Past Practice in Australasia as Assessed through the Royal College of Pathologists of Australasia Quality Assurance Program for Hematology

We have conducted a series of multilaboratory surveys during the last 6 years to evaluate testing proficiency in the detection of congenital and acquired thrombophilia. For lupus anticoagulant (LA) testing, participant laboratories used a panel of tests, including activated partial thromboplastin time (aPTT; 100% of laboratories), kaolin clotting time (26 to 70%), and Russell's viper venom time (RVVT; 75 to 100%). Coefficients of variation (CVs) for assays ranged from 5 to 40%. RVVT assays appeared to be most sensitive and specific for detection of LA (fewer false-negatives or -positives), although laboratories performed best when they used a panel of tests. For congenital thrombophilia, tests evaluated comprised protein C (PC), protein S (PS), antithrombin (AT), and activated protein C resistance (APCR). Most participant laboratories performed PC using chromogenic (approximately 75%), or clot based (approximately 15%) assays, with few (< 10%) performing antigenic assessments. PS was most often assessed (approximately 60%) by immunological or antigenic assays, usually of free PS, or by functional or clot-based assays (approximately 40%). AT is usually assessed by functional chromogenic assays (approximately 95%). APCR was assessed using aPTT (approximately 50%) or RVVT (approximately 50%) clot-based assays, with the aPTT APCR typically performed using factor V-deficient plasma predilution, but the RVVT APCR typically performed without. Laboratories using the RVVT APCR generally performed better in detection of factor V Leiden-associated APCR, with the aPTT method group yielding higher false-negative and/or false-positive findings (approximately 5% of occasions). Some clot-based PC and PS assays appeared to be influenced by APCR status, and yielded lower apparent PC and PS levels with positive APC resistance. The overall error rate for PC, PS, and AT was approximately 2 to 8% (i.e., false-normal interpretations for deficient plasma or false-abnormal interpretations for normal plasma). The CVs for these assays ranged from 5 to 40%, with highest CVs typically obtained with PS assays.

159 TWIN vs. SINGLE TRANSFER OF IVP HOLSTEIN HEIFER EMBRYOS TO BEEF RECIPIENTS

Use of sexed semen in conjunction with in vitro embryo production is a potentially efficient means of obtaining offspring of predetermined sex. Here we evaluate a production scheme involving single and bilateral twin transfer of Holstein female embryos to beef cattle recipients. Holstein oocytes were fertilized with the X-bearing fraction of gender-sorted Holstein semen. Cumulus cells were removed with aid of a vortex or microfluidic device (μFD). Half of the vortexed embryos were cultured in KSOMaaBSA (control), as were all μFD embryos. The remaining vortexed embryos were cultured in control medium with 6% avian white yolk (WY). Embryo production and transfer occurred across five replicates. Cows (n = 475) were synchronized using an Ovsynch protocol. They were administered GnRH on Day −9, PGF on Day −2, and GnRH on Day 0. Half of the cows received a CIDR (1.38 g progesterone) with the 1st GnRH injection. The CIDR was removed at the time of PGF treatment. Day 7 Grade 1 blastocysts were transferred fresh 7 days after the 2nd GnRH injection. Control and WY embryos were transferred as ipsilateral singles and bilateral twins; μFD embryos were transferred singly. Pregnancy was diagnosed with ultrasound between 41–46 days and confirmed between 60–90 days; fetal sexing confirmed that 95% of fetuses were female. Effects on embryo survival were analyzed by logistic regression. Chi-square analysis was applied to survival rates. Replication affected embryo survival (P < 0.05). There was no effect of cumulus removal, medium, or CIDR use. Fetal loss between ultrasounds was greater for twin vs. single transfers (30% vs. 15%, respectively; P < 0.01). Probability of embryo survival was estimated to increase ∼0.006 with each increasing day postpartum. Five cases of hydrallantois were detected during the 5th month of gestation for 1 control twin, 1 WY single, and 3 WY twin transfers, originating from 3 replicates. On a production per transfer basis, the proportion of fetuses obtained for single and twin transfers was 30% and 55%, respectively (P < 0.001). Although there was greater embryonic loss for twin compared to single transfers, a higher percentage of cows receiving twins established and maintained pregnancy. Large-scale transfer of IVP Holstein heifer embryos to beef recipients is a feasible production scheme. Table 1. Embryo survival and pregnancy rates

Friends reunited? Evolutionary robotics and representational explanation

Robotics as practiced within the artificial life community is no longer the bitter enemy of representational explanation in the way that it sometimes seemed to be in the heady, revolutionary days of the 1990s. This rapprochement is, however, fragile, because the field of evolutionary robotics continues to pose two important challenges to the idea that real-time intelligent action must or should be explained by appeal to inner representations. The first of these challenges, the threat from nontrivial causal spread, occurs when extra-neural factors account for the kind of adaptive richness and flexibility normally associated with representation-based control. The second, the threat from continuous reciprocal causation, occurs when the causal contributions made by the systemic components collectively responsible for behavior generation are massively context-sensitive and variable over time. I argue that while the threat from nontrivial causal spread can be resisted, the threat from continuous reciprocal causation provides a stern test for our representational intuitions.

Androgen status in healthy premenopausal women with loss of libido

Androgen deficiency may contribute to female sexual dysfunction and loss of libido. The role of the active metabolite of testosterone, dihydrotestosterone (DHT), in these conditions is uncertain. The aim of this study was to determine the role of androgens and DHT in the etiology of loss of libido in healthy women. We studied 29 premenopausal women with reduced libido (subjects) and 12 healthy females (controls). They were aged 18 to 45 years and in a stable heterosexual relationship. At 9 a.m. we took venous blood in the follicular phase for serum estradiol, total testosterone, and DHT, dehydroepiandrosterone sulfate (DHEAS), and SHBG levels. Subjects were interviewed by a psychosexual counsellor. Using the modified Wilson's sexual fantasy questionnaire (Baumgartner, Scalora, & Huss, 2002) and sexual satisfaction by Golombok-Rust Inventory of Sexual Satisfaction (GRISS Rust & Golombok, 1985, 1986) we assessed sexual drive. The total testosterone and DHT levels (mean +/- SD) were respectively 0.97 +/- 0.38 mmol/L and 0.76 +/- 0.37 nmol/L in subjects and 0.97 +/- 0.41 mmol/L and 0.77 +/- 0.15 nmol/L in controls. The SHBG and DHEAS were respectively 65 +/- 42 mmol/L and 3.76 +/- 1.0 umol/L in subjects and 65 +/- 29 mmol/L and 3.67 +/- 2.6 in controls. The scores of the Wilson questionnaire and GRISS were respectively 21 +/- 14.1 and 5 +/- 2.1 in subjects and 35 +/- 14.8 & 2 +/- 1.2 in controls. Subjects were more likely than controls to have low income (48% versus 8%, p < 0.02), a minor illnesses (57% versus 17%, p < 0.02), a history of depression (57% versus 8%, p = 0.025) and to report sexual problems in their partners (24% versus 0%, p = 0.053). Loss of libido in otherwise healthy women may be related to relationship problem, depression, psychosocial factors, and sexual dysfunction in the partner but do not appear to be related to androgen status.

The relationship of sex hormones and cortisol with cognitive functioning in Schizophrenia

Gonadal as well as stress hormones have recently been implicated in pathophysiology and sex differences in onset, prognosis and treatment of schizophrenia. The present study investigated the effects of serum levels of oestrogen, progesterone, testosterone and cortisol on neuropsychological functioning and psychopathology in a group of 37 patients (17 women, 20 men) with schizophrenia. Neuropsychological measures included tests of attention, verbal abilities, language, memory, executive functioning, motor and speed of information processing. The results showed that oestrogen and age was associated with low positive symptom scores, and within gender, cortisol predicted poor performance on the information processing domain in men. These findings demonstrate that cortisol, in addition to the commonly reported effects of oestrogen, influences neuropsychological functioning in schizophrenia with differential effects on specific domains of cognitive functioning and underscore the need for further investigation of the modulating role of hormones on neuropsychological functioning in schizophrenia.

Polymorphisms in the P450 c17 (17-hydroxylase/17,20-Lyase) and P450 c19 (aromatase) genes: association with serum sex steroid concentrations and bone mineral density in postmenopausal women

The CYP 17 and CYP 19 genes encode 17alpha-hydroxylase/17,20-lyase and aromatase, respectively, both involved in sex hormone synthesis. We investigated the association between 2 common polymorphisms in 1) the promoter region (T-->C substitution) of CYP 17, and 2) exon 3 (G-->A) of CYP 19, bone mineral density (BMD) and serum androgen/estradiol, in a case-control study of 252 postmenopausal women aged 64.5 +/- 9.2 yr (mean +/- SD). There was no significant difference in serum estradiol concentrations between cases (n = 136) and controls (n = 116). The CYP 19 genotype was significantly associated with serum estradiol (P = 0.002). Women with the AA genotype had higher serum estradiol concentrations compared with those with the GG genotype (P = 0.03). In older women, those with the CYP 19 GA and GG genotypes had an increased prevalence of osteoporosis (P = 0.04) and fractures (P = 0.003). We found no significant association between CYP 17 genotype and serum androgens and estradiol concentrations. However, a significant association was seen between BMD values at the femoral neck with CYP 17 genotype in cases (P = 0.04) and in the whole study population (P = 0.012). Subjects with the CC genotype had significantly lower BMD (mean +/- SD: TT, 0.7 +/- 0.16; CC, 0.6 +/- 0.08 g/cm(2); P = 0.006). In conclusion, both CYP 17 and CYP 19 are candidate genes for osteoporosis in postmenopausal women.

Deletion of GABAA receptor alpha 1 subunit-containing receptors alters responses to ethanol and other anesthetics

GABA(A) receptors have been implicated in mediating several acute effects of ethanol including anxiolysis, ataxia, sedation/hypnosis, and anticonvulsant activity. Ethanol sensitivity of neurons has been associated with expression of alpha1 subunit-containing receptors. The objective of this study was to determine the contribution of alpha1 subunit containing receptors to ethanol responses in comparison to neurosteroids and other anesthetics using GABA(A) receptor alpha1 subunit knockout mice. Deletion of alpha1 subunit-containing receptors did not alter the anxiolytic, ataxic, anticonvulsant, or hypnotic effects of ethanol or acute functional tolerance to ethanol but did increase sensitivity to the locomotor-stimulating effects of ethanol. The ability of ethanol to potentiate muscimol-stimulated chloride uptake and ethanol clearance was also not altered following alpha1 subunit deletion. The anticonvulsant and hypnotic effects of neurosteroids as well as their potentiating effect on GABA-mediated Cl(-) uptake were unaltered in alpha1(-/-) mice. The hypnotic effect of pentobarbital, etomidate, and midazolam were reduced, whereas the effect of ketamine was enhanced in alpha1(-/-) mice. Thus, GABA(A) receptor alpha1 subunit-containing receptors appear to influence the motor-stimulating effect of ethanol and the sedative/hypnotic effects of some anesthetics, but not ethanol. These receptors do not appear to be necessary for most ethanol responses, suggesting involvement of other GABA(A) receptor subtypes or other targets altogether.

Emerging techniques in biomedical research and their application to alcohol toxicity

This article represents the proceedings of a symposium at the 2002 RSA-ISBRA Meeting in San Francisco. The chairs were Vinood B. Patel and Victor R. Preedy. The presentations were (1) Macromolecular structural analysis, by Vinood B. Patel; (2) Profiling and imaging of proteins in tissue sections using mass spectrometry as a discovery tool in biological research, by Pierre Chaurand and Richard M. Caprioli; (3) The use of SELDI ProteinChip trade mark arrays, by Brian M. Austen, Emma R. Frears, Francesca Manca, and Huw Davies; (4) DNA hybridization array technologies, by Kent E. Vrana; and (5) Adeno- and adeno-associated viral mediated gene transfer approaches for alcoholic liver disease, by Michael Wheeler. Concluding remarks were by Victor R. Preedy.

Demonstration of reduced in vivo surface expression of activating mutant thyrotrophin receptors in thyroid sections

OBJECTIVE

Thyroid function and growth are controlled by TSH. Hyperthyroidism can be due to Graves' Disease (GD), in which thyroid-stimulating antibodies mimic TSH, or gain-of-function mutations in the TSH receptor (TSHR). These activating mutations have poor surface expression when assessed in non-thyroidal cells in vitro but nothing is known of their in vivo behaviour. Several TSHR antibodies have been produced but none has been applied to thyroid paraffin sections. This study aimed to develop a technique suitable for use on paraffin sections and apply it to investigate TSHR expression in thyroids harbouring activating TSHR germline mutations compared with normal and GD thyroids.

DESIGN AND METHODS

Immunocytochemistry coupled with antigen retrieval, using a spectrum of antibodies to the TSHR, was applied to paraffin sections of GD thyroid tissue. Subsequently, TSHR immunoreactivity was examined in three normal thyroids, three patients with GD and three patients with familial hyperthyroidism, due to different gain-of-function TSHR germline mutations, using the optimised protocol.

RESULTS

Two antibodies, A10 and T3-495, to the extracellular domain (ECD) and membrane spanning region (MSR) of the TSHR respectively, produced specific basolateral staining of thyroid follicular cells. In normal and GD thyroids, basolateral staining with T3-495 was generally more intense than with A10, suggesting a possible surfeit of MSR over ECD. Graves' Disease thyroids have more abundant TSHR than normal glands. In contrast, thyroids harbouring gain-of-function mutations have the lowest expression in vivo, mirroring in vitro findings.

CONCLUSIONS

The development of an immunocytochemical method applicable to paraffin sections has demonstrated that different molecular mechanisms causing hyperthyroidism result in the lowest (mutation) and highest (autoimmunity) levels of receptor at the thyrocyte surface.

Microfluidic technology for assisted reproduction

The physical tools used in assisted reproduction have changed little over several decades. Microfluidics is an emerging technology that allows a fresh examination of the way assisted reproduction is performed. Here we review our work to develop microfluidic devices to perform the functions required in assisted reproduction. These functions include loading/unloading, culture, chemical manipulation, and mechanical manipulation of embryos and oocytes. Basic microfluidic theory and microfluidic device design and operation are discussed. Results are presented for mechanical removal of cumulus cells and for embryo culture. Results suggest that microfluidic systems will lead to improved efficiencies in assisted reproduction.

The view from elsewhere: perspectives on ALife modeling

Many artificial life researchers stress the interdisciplinary character of the field. Against such a backdrop, this report reviews and discusses artificial life, as it is depicted in, and as it interfaces with, adjacent disciplines (in particular, philosophy, biology, and linguistics), and in the light of a specific historical example of interdisciplinary research (namely cybernetics) with which artificial life shares many features. This report grew out of a workshop held at the Sixth European Conference on Artificial Life in Prague and features individual contributions from the workshop's eight speakers, plus a section designed to reflect the debates that took place during the workshop's discussion sessions. The major theme that emerged during these sessions was the identity and status of artificial life as a scientific endeavor.

Recruitment of the class II phosphoinositide 3-kinase C2beta to the epidermal growth factor receptor: role of Grb2

Previously we demonstrated that the class II phosphoinositide 3-kinase C2beta (PI3K-C2beta) is rapidly recruited to a phosphotyrosine signaling complex containing the activated receptor for epidermal growth factor (EGF). Although this association was shown to be dependent upon specific phosphotyrosine residues present on the EGF receptor, the underlying mechanism remained unclear. In this study the interaction between PI3K-C2beta and the EGF receptor is competitively attenuated by synthetic peptides derived from each of three proline-rich motifs present within the N-terminal region of the PI3K. Further, a series of N-terminal PI3K-C2beta fragments, truncated prior to each proline-rich region, bound the receptor with decreased efficiency. A single proline-rich region was unable to mediate receptor association. Finally, an equivalent N-terminal fragment of PI3K-C2alpha that lacks similar proline-rich motifs was unable to affinity purify the activated EGF receptor from cell lysates. Since these findings revealed that the interaction between the EGF receptor and PI3K-C2beta is indirect, we sought to identify an adaptor molecule that could mediate their association. In addition to the EGF receptor, PI3K-C2beta(2-298) also isolated both Shc and Grb2 from A431 cell lysates. Recombinant Grb2 directly bound PI3K-C2beta in vitro, and this effect was reproduced using either SH3 domain expressed as a glutathione S-transferase (GST) fusion. Interaction with Grb2 dramatically increased the catalytic activity of this PI3K. The relevance of this association was confirmed when PI3K-C2beta was isolated by coimmunoprecipitation with anti-Grb2 antibody from numerous cell lines. Using immobilized, phosphorylated EGF receptor, recombinant PI3K-C2beta was only purified in the presence of Grb2. We conclude that proline-rich motifs within the N terminus of PI3K-C2beta mediate the association of this enzyme with activated EGF receptor and that this interaction involves the Grb2 adaptor.