Considerations for occupational risk management during pregnancy: A summary of a continuing education course.

Women comprise approximately 40% of the global workforce, and many women continue to work during pregnancy. Although occupational exposure limit values (OELVs) are intended to protect all workers, many OELVs may have been established without consideration of the unique changes in pregnant workers, and many chemicals lack OELVs altogether. A short educational course was developed to address the informational needs of health professionals who have responsibility to ensure a safe workplace for pregnant employees. The course was designed to raise awareness of the key elements in risk management and their application to the pregnant worker, such as physiological changes of pregnancy that influence susceptibility to exposures; guidance for nonclinical data interpretation; exposure assessment and control strategies; and risk management in practice in a diverse regulatory environment. This paper summarizes the course content and is intended to support informed risk management decision making to protect the health of pregnant workers and their offspring.

Vero/BC-F: an efficient packaging cell line stably expressing F protein to generate single round-infectious human parainfluenza virus type 2 vector.

A stable packaging cell line (Vero/BC-F) constitutively expressing fusion (F) protein of the human parainfluenza virus type 2 (hPIV2) was established for production of the F-defective and single round-infectious hPIV2 vector in a strategy for recombinant vaccine development. The F gene expression has not evoked cytostatic or cytotoxic effects on the Vero/BC-F cells and the F protein was physiologically active to induce syncytial formation with giant polykaryocytes when transfected with a plasmid expressing hPIV2 hemagglutinin-neuraminidase (HN). Transduction of the F-defective replicon RNA into the Vero/BC-F cells led to the release of the infectious particles that packaged the replicon RNA (named as hPIV2ΔF) without detectable mutations, limiting the infectivity to a single round. The maximal titer of the hPIV2ΔF was 6.0 × 10(8) median tissue culture infections dose per ml. The influenza A virus M2 gene was inserted into hPIV2ΔF, and the M2 protein was found to be highly expressed in a human lung cancer cell line after transduction. Furthermore, in vivo airway infection experiments revealed that the hPIV2ΔF was capable of delivering transgenes to hamster tracheal cells. Thus, non-transmissible or single round-infectious hPIV2 vector will be potentially applicable to human gene therapy or recombinant vaccine development.

Efficient gene transfer to airway epithelium using recombinant Sendai virus.

Clinical studies of gene therapy for cystic fibrosis (CF) suggest that the key problem is the efficiency of gene transfer to the airway epithelium. The availability of relevant vector receptors, the transient contact time between vector and epithelium, and the barrier function of airway mucus contribute significantly to this problem. We have recently developed recombinant Sendai virus (SeV) as a new gene transfer agent. Here we show that SeV produces efficient transfection throughout the respiratory tract of both mice and ferrets in vivo, as well as in freshly obtained human nasal epithelial cells in vitro. Gene transfer efficiency was several log orders greater than with cationic liposomes or adenovirus. Even very brief contact time was sufficient to produce this effect, and levels of expression were not significantly reduced by airway mucus. Our investigations suggest that SeV may provide a useful new vector for airway gene transfer.

3,4-methylenedioxymethamphetamine (ecstasy)-induced learning and memory impairments depend on the age of exposure during early development.

Use of 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) has increased dramatically in recent years, yet little is known about its effects on the developing brain. Neonatal rats were administered MDMA on days 1-10 or 11-20 (analogous to early and late human third trimester brain development). MDMA exposure had no effect on survival but did affect body weight gain during treatment. After treatment, body weight largely recovered to 90-95% of controls. MDMA exposure on days 11-20 resulted in dose-related impairments of sequential learning and spatial learning and memory, whereas neonatal rats exposed on days 1-10 showed almost no effects. At neither stage of exposure did MDMA-treated offspring show effects on swimming ability or cued learning. Brain region-specific dopamine, serotonin, and norepinephrine changes were small and were not correlated to learning changes. These findings suggest that MDMA may pose a previously unrecognized risk to the developing brain by inducing long-term deleterious effects on learning and memory.

Accommodation of foreign genes into the Sendai virus genome: sizes of inserted genes and viral replication.

Sendai virus (SeV) is an enveloped virus with a negative sense genome RNA of about 15.3 kb. We previously established a system to recover an infectious virus entirely from SeV cDNA and illustrated the feasibility of using SeV as a novel expression vector. Here, we have attempted to insert a series of foreign genes into SeV of different lengths to learn how far SeV can accommodate extra genes and how the length of inserted genes affects viral replication in cells cultured in vitro and in the natural host, mice. We show that a gene up to 3.2 kb can be inserted and efficiently expressed and that the replication speed as well as the final virus titers in cell culture are proportionally reduced as the inserted gene length increases. In vivo, such a size-dependent effect was not very clear but a remarkably attenuated replication and pathogenicity were generally seen. Our data further confirmed reinforcement of foreign gene expression in vitro from the V(-) version of SeV in which the accessory V gene had been knocked out. Based on these results, we discuss the utility of SeV vector in terms of both efficiency and safety.

Plasma levels of leukotriene E4 during clinical course of bronchial asthma and the effect of oral prednisolone.

To investigate the relationship between circulating leukotriene E4 and bronchial asthma, we tried to measure the concentration of leukotriene E4 during the clinical course of bronchial asthma with or without oral prednisolone treatment. Additionally, we investigated the relationship between the LTE4 levels and FEV1 (percent predicted) and PaCO2 (mm Hg) concomitantly. Two milliliters of blood were drawn from the femoral artery of eight patients on three occasions: (1) during remission; (2) during an attack treated without prednisolone; and (3) during an attack treated with prednisolone. Leukotriene E4 was detected by high-pressure liquid chromatography and radioimmunoassay. In eight asthmatic patients, mean (SD) leukotriene E4 levels on the three occasions were 11.8 (2.61), 48.4 (18.2), and 32.6 (8.28) pg/ml, respectively. In contrast, the mean leukotriene E4 level of ten normal control subjects was 11.8 (4.49) pg/ml. Leukotriene E4 levels differed significantly between remission and attack treated without prednisolone, and between attacks treated with and without prednisolone. Mean FEV1 values were 85.5 (3.07), 50.5 (9.58), and 65.9 (7.44) on the three occasions, respectively; corresponding mean PaCO2 values were 31.7 (2.74), 55.5 (5.81), 48.9 (2.56), respectively. Leukotriene E4 was significantly correlated with FEV1 and relatively with PaCO2 during an attack without prednisolone. We suggest that leukotriene E4 levels in arterial blood reflect the severity of asthmatic attacks and orally administered prednisolone may affect the leukotriene E4 levels.

Azelastine hydrochloride inhibits platelet activating factor-like activity in human eosinophils.

We investigated the inhibitory effect of azelastine hydrochloride (azelastine), an anti-asthmatic drug, on platelet-activating factor (PAF)-like activity in eosinophils obtained from asthmatic and non-asthmatic patients. Eosinophils were preincubated with or without azelastine and stimulated with f-Met-Leu-Phe (fMLP, 10 mumol) for 15 min. PAF-like activity was detected by aggregation of washed guinea-pig platelets. PAF-like activity released from asthmatic eosinophils without preincubation of azelastine was 2.36 [1.02] (mean [SD], ng/10(7) cells) in supernatants and 13.87 [4.77] in cell pellets. After preincubation with 10(-8), 10(-6), and 10(-4) M azelastine, PAF-like activity reduced to 1.85 [0.46] (mean [SD], ng/10(7) cells), 1.11 [0.14], and 0.88 [0.09] (n = 15) in the supernatants, and 11.83 [2.93], 8.32 [1.41], and 6.27 [1.25] (n = 15) in the cell pellets, respectively. PAF-like activity in non-asthmatic eosinophils without preincubation of azelastine was 2.01 [0.86] (mean [SD], ng/10(7) cells) in supernatants and 7.44 [0.99] in cell pellets. After preincubation with 10(-8), 10(-6), and 10(-4) M azelastine, PAF-like activity reduced to 1.73 [0.64] (mean [SD], ng/10(7) cells), 1.12 [0.23], and 0.84 [0.17] (n = 20) in the supernatants, and 6.26 [2.08], 4.65 [0.88], and 3.02 [0.43] (n = 20) in the cell pellets, respectively. Our results showed that preincubation with azelastine caused a dose-dependent inhibition of intra and extracellular PAF-like activity from asthmatic and non-asthmatic eosinophils in the same manner.

Oxatomide inhibits synthesis and release of platelet-activating factor in human neutrophils.

Effect of oxatomide on release and production of platelet-activating factor (PAF) in neutrophils obtained from asthmatic and non-asthmatic patients was investigated. Neutrophils were preincubated with or without oxatomide and stimulated with N-formyl-L-methionyl-L-leucyl-L-phenylalanine (f-MLP, 10 microM) for 15 min. PAF activity was detected by aggregation of washed guinea pig platelets. PAF activity released from asthmatic neutrophils without preincubation of oxatomide was 7.97[0.22] (mean[SEM], ng/10(7) cells) in supernatants and 33.4[0.26] in cell pellets. After preincubation with 10(-8), 10(-6), and 10(-4) M of oxatomide, PAF activity reduced to 6.77[0.37] (mean[SEM], ng/10(7) cells), 3.99[0.25], and 0.96[0.05] (n = 15) in the supernatants, and 22.4[0.31], 16.7[0.22], and 6.35[0.11] (n = 15) in the cell pellets, respectively. PAF activity in non-asthmatic neutrophils without preincubation of oxatomide was 6.35[0.12] (mean[SEM], ng/10(7) cells) in supernatants and 27.9[0.25] in cell pellets. After preincubation with 10(-8), 10(-6), and 10(-4) M of oxatomide, PAF activity reduced to 5.02[0.16] (mean [SEM], ng/10(7) cells), 3.96[0.11], and 0.94[0.03] (n = 10) in the supernatants, and 28.4[0.69], 13.78[0.17], and 2.88[0.27] (n = 10) in the cell pellets, respectively. Our results showed that preincubation with oxatomide caused a dose-dependent inhibition of intra- and extracellular PAF activity from asthmatic and non-asthmatic neutrophils in the same manner.

Inhibitory effect of amphotericin B on leukotriene B4 synthesis in human neutrophils in vitro.

Our objective was to determine the effect of amphotericin B on leukotriene (LT) A4 hydrolase in human neutrophil cytosol and to examine its effect on intact neutrophils in vitro. Cytosolic fractions were assayed for LTA4 hydrolase and 5-lipoxygenase activity in the presence or absence of amphotericin B. The IC50 of amphotericin B for LTA4 hydrolase activity was 0.72 microM. No inhibition of 5-lipoxygenase activity in the cytosolic fraction was detected. The IC50 of amphotericin B for leukotriene B4 synthesis in intact neutrophils was 0.43 microM. The 5-hydro(per) oxy-eicosatetraenoic acid (5-H(P)ETE) synthesis was diminished in intact cells by 66.8 [3.4]% (mean[SEM]) in the presence of 0.01 mM amphotericin B. Thus, amphotericin B inhibited the synthesis of LTB4 and 5-H(P)ETE in neutrophils in vitro. Differences between the results of studies on cytosol and on intact cells suggest that amphotericin B is involved in a complex interaction in the intact cell.

Effect of azelastine hydrochloride on release and production of platelet activating factor in human neutrophils.

Effect of azelastine hydrochloride (azelastine) on release and production of platelet-activating factor (PAF) in neutrophils obtained from asthmatic and non-asthmatic patients was investigated. Neutrophils were preincubated with or without azelastine and stimulated with f-Met-Leu-Phe (fMLP, 10 microM) for 15 min. PAF-like activity was detected by aggregation of washed guinea pig platelets. PAF-like activity released from asthmatic neutrophils without preincubation of azelastine was 5.67[0.89] (mean[SD], ng/10(7) cells) in supernatants and 21.8[0.76] in cell pellets. After preincubation with 10(-8), 10(-6), and 10(-4) M of azelastine, PAF-like activity reduced to 5.96[0.97] (mean[SD], ng/10(7) cells), 3.49[0.63], and 1.89[0.09] (n = 15) in the supernatants, and 20.7[0.97], 13.9[0.29], and 8.91 [0.99] (n = 15) in the cell pellets, respectively. PAF-like activity in non-asthmatic neutrophils without preincubation of azelastine was 4.67[0.19] (mean[SD], ng/10(7) cells) in supernatants and 18.5[0.34] in cell pellets. After preincubation with 10(-8), 10(-6), and 10(-4) M of azelastine, PAF-like activity reduced to 4.39[0.51] (mean[SD], ng/10(7) cells), 2.77[0.22], and 1.75[0.07] (n = 15) in the supernatants, and 17.9[0.54], 10.8[0.25], and 5.97 [0.59] (n = 15) in the cell pellets, respectively. Our results showed that preincubation with azelastine caused a dose-dependent inhibition of intra and extracellular PAF-like activity from asthmatic and non-asthmatic neutrophils in the same manner.

Inhibitory effect of azelastine hydrochloride on synthesis and release of platelet activating factor from human alveolar macrophages.

The effect of azelastine hydrochloride (azelastine) on synthesis and release of platelet activating factor (PAF) in alveolar macrophages obtained from asthmatic and non-asthmatic subjects was examined. Alveolar macrophages (AMs) were preincubated with or without azelastine and stimulated with f-Met-Leu-Phe (fMLP, 10 microM) for 15 min. PAF activity was detected by aggregation of washed guinea pig platelets. PAF activity released from alveolar macrophages (AMs) from asthmatics without preincubation of azelastine was 15.97 [2.17] (mean [SD], ng/10(7) cells) in supernatants and 42.52 [10.16] in cell pellets. After preincubation with 10(-8), 10(-6), and 10(-4) M of azelastine, PAF activity reduced to 10.71 [2.73] (mean [SD], ng/10(7) cells), 7.86 [0.94], and 3.52 [0.31] in the supernatants, and 35.58 [7.37], 21.57 [4.36], and 14.77 [0.99] (n = 15) in the cell pellets, respectively. PAF activity in non-asthmatic subjects without preincubation of azelastine was 8.55 [1.16] (mean [SD], ng/10(7) cells) in supernatants and 32.64 [3.37] in cell pellets. After preincubation with 10(-8), 10(-6), and 10(-4) M of azelastine, PAF activity reduced to 6.68 [0.78] (mean [SD], ng/10(7) cells), 4.47 [0.51], and 2.97 [0.36] in the supernatants, and 29.53 [3.75], 14.78 [1.95], and 6.16 [0.55] (n = 20) in the cell pellets, respectively. Our results showed that preincubation with azelastine caused a dose-dependent inhibition of intra- and extracellular PAF activity from asthmatic and non-asthmatic macrophages in the same manner.

Prednisolone inhibits synthesis of 5-H(P)ETE in eosinophils from asthmatic patients during a wheezing attack but not during remission.

To estimate the effect of prednisolone on 5-lipoxygenase activity in eosinophils obtained from asthmatic patients, cytosolic levels of 5-H(P)ETE and Ca2+ were measured in the eosinophils which were exposed to prednisolone in vitro and in vivo. The mean level of 5-H(P)ETE during a wheezing attack was significantly lower in the patients who had received intravenous prednisolone (500 mg/day). Incubation with prednisolone in vitro caused a dose-dependent decrease in the cytosolic levels of 5-H(P)ETE and Ca2+ in eosinophils obtained during the wheezing attack, but not in the eosinophils obtained from during remission. Results suggest that prednisolone inhibits the level of 5-H(P)ETE in the eosinophil cytosols of asthmatic patients during a wheezing attack, probably by inhibition of 5-lipoxygenase activity which is involved in the reduction of the influx of Ca2+.

Plasma levels of leukotriene E4 during clinical course of chronic obstructive pulmonary disease.

We investigated the relationship between circulating leukotriene E4 (LTE4) and chronic obstructive pulmonary disease (COPD) by measuring plasma levels of leukotriene E4 in patients with COPD and 10 normal controls. We also investigated the relationship between LTE4 levels and FEV1 and PaO2. Leukotriene E4 was measured by high performance liquid chromatography (HPLC) and radioimmunoassay. The mean leukotriene E4 level in patients with COPD during remission, during acute exacerbation before and after prednisolone treatment were 16.8[4.02], 41.7[21.9], and 19.5[3.78] pg/ml (mean[SD]), respectively. In contrast, the mean leukotriene E4 level of 10 normal controls was 11.8[4.49] pg/ml. Thus, the mean LTE4 level during an acute exacerbation of COPD was significantly lower in patients after prednisolone treatment than in patients before prednisolone treatment. The mean LTE4 level in patients after prednisolone treatment did not significantly differ from that in patients during remission and in normal controls (Scheffe F-test, P < 0.05) (Fig. 1). Mean FEV1 (% predict) values were 51.4[9.02] (mean[SD]), 38.0[4.82], and 44.2[4.48] on the three occasions, respectively; corresponding mean PaO2 values (mmHg) were 84.0[5.01] (mean[SD]), 61.3[1.66], and 80.6[5.30], respectively. Leukotriene E4 levels were significantly correlated with PaO2 and relatively with FEV1 in the patients during acute exacerbation before prednisolone treatment. Thus, we suggest that leukotriene E4 levels in arterial blood reflect the severity of COPD lung and oral prednisolone reduces the plasma levels of leukotriene E4 in patients with COPD.

A single dose model of methamphetamine-induced neurotoxicity in rats: effects on neostriatal monoamines and glial fibrillary acidic protein.

The neurotoxic effects of a single administration of methamphetamine (MA) were studied under conditions conducive to MA-induced hyperthermia. After a single dose of MA (10, 20, 30, or 40 mg/kg, s. c.) or saline (3 ml/kg) to Sprague-Dawley CD rats, rectal temperatures were monitored for 9 h in a room with an ambient temperature of 22.0+/-0.5 degrees C. MA induced significant dose-dependent hyperthermia, however, no significant increase in mortality occurred. Neostriatal DA, 5-HT, TH, and GFAP were assayed 3 days following treatment. MA induced dose-dependent reductions of DA, 5-HT and TH, and increased GFAP. For DA, at doses of 20, 30, or 40 mg/kg the reductions were to 71%, 49%, and 29%, and for 5-HT were to 73%, 44%, and 19% of control values. No reductions were seen after the 10 mg/kg dose. Semiquantitative analysis Western blots of TH and GFAP demonstrated that TH was reduced to 52%, 75%, and 28%, and GFAP was increased to 125%, 134%, and 149% of control values at MA doses of 20, 30, or 40 mg/kg, respectively. No significant changes in TH or GFAP were seen at the 10 mg/kg MA dose. These results demonstrate that a single-dose of MA can be as effective as the widely used four-dose every 2 h regimen. Moreover, mortality can be minimized by monitoring core body temperature and preventing MA-induced hyperthermia from exceeding 41.5 degrees C.

Immunohistochemical investigation of caspase-1 and effect of caspase-1 inhibitor in delayed neuronal death after transient cerebral ischemia.

The localization of caspase-1 protein, interleukin-1beta (IL-1beta)-converting enzyme, was immunohistochemically examined in the hippocampal CA-1 subfield by a transient occlusion of bilateral common carotid arteries in Mongolian gerbils. Immunoreactivities for caspase-1 were found in microglias, astrocytes, endothelial cells of capillaries and some non-pyramidal neurons. Immunopositive microglias increased in number from 3 days until 7 days from the transient ischemia, and astrocytes also increased in number from 3 days until 28 days. At the electron microscopic level, caspase-1 immunoreaction endproducts were associated with Golgi apparatus in glial cells, endothelial cells of blood vessels and non-pyramidal neurons. The delayed neuronal death of CA-1 pyramidal cells was significantly protected by the treatment of specific caspase-1 inhibitor (Ac-WEHD-CHO) or broad caspase family inhibitor (z-VAD-FMK). Cell death was protected in a dose dependent manner by the former by 43-57%, and by the latter by 66-91% when injected at 1 and 10 microg, respectively. On the other hand, the protective effect of specific caspase-3 inhibitor (Ac-DMQD-CHO) was less significant at higher dose (10 microg) by 33% (P<0.05), and not detectable at lower dose (1 microg) by 13% (P=0.27). Furthermore, a significant decrease of microglias and astrocytes was found in the CA-1 as well as the reduction of IL-1beta and caspase-1 immunoreactivities by the treatment of Ac-WEHD-CHO. Extravasation of serum albumin was also extremely reduced by this treatment. These findings suggest that the inhibition of caspase-1 activity ameliorates the ischemic injury by inhibiting the activity of IL-1beta.

Rescue of ischemic brain injury by adenoviral gene transfer of glial cell line-derived neurotrophic factor after transient global ischemia in gerbils.

Glial cell line-derived neurotrophic factor (GDNF), a member of the transforming growth factor (TGF)-beta superfamily, is one of the most potent neurotrophic factors and promotes survival of many populations of cells. We examined neuroprotective effect of an adenoviral vector encoding glial cell line-derived neurotrophic factor (AxCAhGDNF) on the transient global ischemia. Gerbils received administration of AxCAhGDNF or an adenoviral vector encoding bacterial beta-galactosidase gene (AxCALacZ) through the lateral ventricle. Two days later, occluding bilateral common carotid arteries for 5 min using aneurysm clips produced the transient global forebrain ischemia. Animals showed intense immunolabeling for GDNF in ependymal cells on 2, 4 and 7 days after the operation. The exogenous gene transducted by adenovirus in the same cells was detected by in situ hybridization. The treatment with AxCAhGDNF significantly prevented the loss of hippocampal CA1 pyramidal neurons 2 to 7 days after the operation, as compared to AxCALacZ treatment. Also terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick end labeling (TUNEL) staining was markedly reduced in the case with AxCAhGDNF treatment at 7 days after the operation. These results indicated that the adenovirus-mediated gene transfer of GDNF might prevent the delayed neuronal death of stroke and other disorders of the cerebral vasculature.

Effect of H2-receptor antagonists on bile acid metabolism.

BACKGROUND: Several reports have been presented concerning pronounced overgrowth of bacteria in gastric juices of patients treated with H2-receptor antagonists. However, there has been no report concerning influence of H2-receptor antagonists on jejunal flora. Thus, to investigate the influence and its effect on bile acid metabolism, this study was performed: 1) to examine whether patients with gastric ulcers who have been treated with H2-receptor antagonists have positive bile acid breath tests due to bacterial overgrowth in their jejuna; 2) to verify that these bacteria, isolated and identified, have deconjugation ability; and 3) to determine whether the changes in the gastric pH are related to bacterial overgrowth. METHODS: The methods used were detection of deconjugation of bile acids in early phase by a bile acid breath test using 5 muCi of oral glycine-1-14C labeled glycocholate, aspiration of jejunal fluids by a double lumen tube with a rubber cover on the tip, and examination of deconjugation ability by thin layer chromatography. RESULTS: Expired breath samples from all 18 patients after administration of H2-receptor antagonists showed a significant increase in 14CO2 specific activity compared with those before administration of H2-receptor antagonist and the normal controls, and bacterial overgrowth was found in the jejunal fluid of the patients after administration of H2-receptor antagonist. The administration of tetracycline to the 18 patients reduced the 14CO2 specific activity significantly. The following species were identified in the jejunal fluid samples obtained from the patients: Escherichia coli, Candida albicans, Pseudomonas aeruginosa, enterococcus, Lactobacillus bifidus, Bacteroides vulgatus, Bacteroides thetaiotaomicron, Bacteroides uniformis, Eubacterium lentum, and Eubacterium parvum. All of the species identified except for Escherichia coli, Pseudomonas aeruginosa, and Candida albicans deconjugated bile acids. There were significant correlations between the 14CO2 activity and gastric pH before and after administration of H2-receptor antagonist, respectively. CONCLUSIONS: Patients with gastric ulcers who were treated with H2-receptor antagonists have increased bile acid deconjugation due to bacterial overgrowth in their jejuna containing species that can deconjugate bile acids. The bacterial overgrowth is probably associated with a shift to neutral pH in the gastric juice caused by the H2-receptor antagonists.

Alteration of bile acid metabolism by cimetidine in healthy humans.

BACKGROUND: To clarify an effect of cimetidine on bile acid metabolism, we evaluated whether an increased deconjugation of bile acids would occur in healthy humans who have received cimetidine. We examined: 1) whether healthy volunteers taking cimetidine would have positive bile acid breath tests because of bacterial overgrowth in the jejunum; 2) whether the isolated bacteria would exhibit deconjugation ability; and 3) whether a change in gastric pH was related to the bacterial overgrowth. METHODS: We evaluated 73 healthy Japanese volunteers; 53 of them received cimetidine and 20 did not. Deconjugation of bile acids was detected as 14CO2 specific activity of expired air measured by a bile acid breath test giving 5 muCi of oral glycine-1-(14)C labeled glycocholate. Aspiration of jejunal fluids was performed by a double lumen tube with a rubber cover on the tip, and deconjugation ability of bacteria was evaluated using thin layer chromotography. RESULTS: Samples of expired breath from the 53 healthy volunteers showed a significant increase in 14CO2 specific activity after the administration of cimetidine rather than before the administration of cimetidine. Bacterial over-growth was found in the jejunal fluid after the administration of cimetidine. The administration of tetracycline to 27 subjects significantly reduced the 14CO2 specific activity. The following species were identified in the jejunal fluid samples obtained from the subjects: enterococcus, Lactobacillus bifidus, Bacteroides vulgatus, B uniformis, Eubacterium lentum, E parvum, and Escherichia coli. Except for E coli, all of the bacterial species identified deconjugated bile acids. We observed a significant relationship between 14CO2's specific activity and gastric pH before and after administration of cimetidine, respectively. CONCLUSIONS: Healthy volunteers who received cimetidine showed an increased deconjugation of bile acid caused by overgrowth of bacteria in the jejunum, which can deconjugate bile acids. The bacterial overgrowth is probably associated with a shift to neutral pH in the gastric juice caused by cimetidine.

Effects of the neurotoxin 3,3'-iminodipropionitrile on acoustic startle and locomotor activity in rats: a comparison of functional observational and automated startle assessment methods.

Iminodipropionitrile (IDPN) is a neurotoxin that has been used in the validation of the U.S. Environmental Protection Agency's Functional Observational Battery (FOB), including acoustic startle. We compared the FOB clicker startle method to an automated procedure. IDPN was administered IP to male Long-Evans rats in three daily doses of 0, 100, 200, or 400 mg/kg (N = 8 per group). There was a significant effect of IDPN on clicker startle that was attributable to reduced startle in the IDPN-400 group. There were multiple significant effects of IDPN on automated startle. The overall effect of IDPN on automated startle was to reduce startle amplitude in the IDPN-400 and -200 groups. In addition, the IDPN-400 group showed startle reductions on all days, whereas the IDPN-200 group showed reduced startle primarily on day 1. IDPN also significantly altered locomotor activity, which was included as an internal check on IDPN's efficacy. The typical pattern of hypolocomotion was found on day 2 posttreatment in the IDPN-400 and -200 groups, followed by hyperlocomotion on all subsequent days in the IDPN-400 group. The startle results demonstrated that automated startle is more sensitive (at least for IDPN treatment), eliminates observer judgments, and provides interval-scaled data compared to the clicker method. However, automated startle also requires additional initial cost and more testing time per animal when multiple trials are presented.

Methamphetamine-induced dopamine and serotonin reductions in neostriatum are not gender specific in rats with comparable hyperthermic responses.

Methamphetamine (MA)-induced monoamine depletions in male and female Sprague-Dawley CD rats were studied under conditions in which the magnitude of MA-induced hyperthermia was comparable between the sexes. MA (5 or 10 mg/kg) or saline (3 ml/kg) was administered SC four times at 2-h intervals. Animals were sacrificed 3 days posttreatment for the determination of dopamine (DA), serotonin (5-HT), and metabolites. MA induced significant monoamine reductions but the magnitude of these reductions was not significantly different between males and females. In the MA 5 mg/kg groups, neostriatal DA content was reduced by 51.2% and 44.8%, whereas 5-HT content was reduced by 30.6% and 23.9% of controls for males and females, respectively. In the MA 10 mg/kg groups, neostriatal DA content was reduced by 72.9% and 65.8%, whereas striatal 5-HT content was reduced by 77.4% and 73.6% of controls for males and females, respectively. No significant differences in thermal responses to MA were observed between genders. Unlike reports in mice, gender does not play a role in MA-induced monoamine reductions in rat neostriatum when MA-induced hyperthermia is comparable across sexes. The data also showed a threshold effect in which dopamine depletions were not correlated with hyperthermia at core body temperatures above approximately 41 degrees C.