Local Anesthesia Thoracoscopy with versus without Midazolam: A Randomized Controlled Trial.

BACKGROUND: Medical thoracoscopy is the gold standard for the diagnosis of pleural diseases. To date, no consensus exists regarding the choice of sedative and analgesic agents in patients undergoing local anesthetic thoracoscopy (LAT), and questions are raised as to whether sedatives may add to respiratory side effects. OBJECTIVE: The aim of the study was to test the hypothesis that administration of midazolam associated with lidocaine versus lidocaine alone in patients with LAT adds to respiratory side effects. METHODS: We randomly assigned 80 patients to a 1:1 study to 2 groups: local anesthesia by lidocaine (n = 40) versus lidocaine and midazolam (n = 40), with the primary end point being the mean lowest oxygen saturation. The secondary end points were cardiovascular parameters, complications, days of drainage, hospital stay, and patients' quality of life (QoL) as assessed by a visual analog scale (VAS). RESULTS: The mean age of all patients was 66.6 ± 13.1 years. The study comprised 50 males (62.5%). No difference was observed in the demographics between the 2 groups. No significant difference was observed between the 2 groups in oxygen saturation (primary end point). A significant difference was observed in favor of the midazolam group regarding the QoL assessed by VAS. CONCLUSION: Midazolam does not add to respiratory side effects when it is used with lidocaine for LAT, while patients' QoL is actually improved in this group. Therefore, in our department, we changed our startegy in favor of the association of lidocaine and midazolam.

Effect of exercise on key pharmacokinetic parameters related to metformin absorption in healthy humans: A pilot study.

Exercise is widely accepted as having therapeutic effects; thus, it is important to know whether it interacts with medications. The aim of the present pilot study was to examine the effect of high-intensity interval exercise (known to have antidiabetic action) on key pharmacokinetic parameters related to absorption of metformin (the first-line medication against type 2 diabetes). Ten healthy men participated in two sessions, spaced one to two weeks apart in random, counterbalanced order. In both sessions, participants received 1000 mg of metformin orally, 1-1.5 hours after breakfast. Then, they either ran for 60 minutes at alternating intensity, starting at 40 minutes after metformin administration, and rested without food consumption over the next 3 hours or they rested without food consumption during the entire testing period. Venous blood samples were collected before and at 0.5, 2, 2.5, 3, 3.5, 4, and 4.5 hours after metformin administration for metformin determination by liquid chromatography-mass spectrometry. Capillary blood samples were also collected for lactate and glucose measurements. Data from the two sessions were compared through Wilcoxon or Student's t test, as appropriate. Maximum plasma concentration of metformin (Cmax ) was higher at exercise compared to rest (P = .059). Time to reach Cmax (Tmax ) decreased with exercise (P = .009), and the area under the metformin concentration vs time curve was higher at exercise (P = .047). The addition of exercise to metformin administration did not cause hypoglycemia or lactic acidosis. In conclusion, our results provide the first evidence that pharmacokinetic values related to metformin absorption are affected by exercise.

Increased Brain Serotonin Rather Than Increased Blood Acetaldehyde as a Common Denominator Behind Alleged Disulfiram-Like Reactions.

Several pharmaceutical agents are known to produce ethanol intolerance, which is often depicted as disulfiram-like reaction. As in the case with disulfiram, the underlying mechanism is believed to be the accumulation of acetaldehyde in the blood, due to inhibition of the hepatic aldehyde dehydrogenases, albeit this has not been confirmed in all cases by blood acetaldehyde measurements. Herein, cefamandole, cotrimoxazole, griseofulvin, procarbazine, and propranolol, which are reported to produce a disulfiram-like reaction, as well as disulfiram, were administered to Wistar rats and the hepatic activities of ethanol metabolizing enzymes along with the levels of brain monoamines were determined. Blood acetaldehyde was also evaluated after ethanol administration in rats pretreated with the abovementioned pharmaceutical products. Disulfiram, cefamandole, and procarbazine significantly increased blood acetaldehyde levels after ethanol administration, while on the contrary, cotrimoxazole, griseofulvin, and propranolol had no effect on blood acetaldehyde. Interestingly, all substances used, except disulfiram, increased the levels of brain serotonin. According to our findings, cotrimoxazole, griseofulvin, and propranolol do not produce a typical disulfiram-like reaction, because they do not increase blood acetaldehyde when given together with ethanol. On the other hand, all tested agents share the common property to enhance brain serotonin, whereas a respective effect of ethanol is well established. Hence, the ethanol intolerance produced by these agents, whether blood acetaldehyde concentration is elevated or not, could be the result of a "toxic serotonin syndrome," as in the case of the concomitant use of serotonin-active medications that provoke clinical manifestations similar to those of a disulfiram reaction.

The Basis for Strain-Dependent Rat Aldehyde Dehydrogenase 1A7 (ALDH1A7) Gene Expression.

Aldehyde hydrogenases (ALDHs) belong to a large gene family involved in oxidation of both endogenous and exogenous compounds in mammalian tissues. Among ALDHs, the rat ALDH1A7 gene displays a curious strain dependence in phenobarbital (PB)-induced hepatic expression: the responsive RR strains exhibit induction of both ALDH1A7 and CYP2B mRNAs and activities, whereas the nonresponsive rr strains show induction of CYP2B only. Here, we investigated the responsiveness of ALDH1A1, ALDH1A7, CYP2B1, and CYP3A23 genes to prototypical P450 inducers, expression of nuclear receptors CAR and pregnane X receptor, and structure of the ALDH1A7 promoter in both rat strains. ALDH1A7 mRNA, associated protein and activity were strongly induced by PB and modestly induced by pregnenolone 16α-carbonitrile in the RR strain but negligibly in the rr strain, whereas induction of ALDH1A1 and P450 mRNAs was similar between the strains. Reporter gene and chromatin immunoprecipitation assays indicated that the loss of ALDH1A7 inducibility in the rr strain is profoundly linked with a 16-base pair deletion in the proximal promoter and inability of the upstream DNA sequences to recruit constitutive androstane receptor-retinoid X receptor heterodimers. SIGNIFICANCE STATEMENT: Genetic variation in rat ALDH1A7 promoter sequences underlie the large strain-dependent differences in expression and inducibility by phenobarbital of the aldehyde dehydrogenase activity. This finding has implications for the design and interpretation of pharmacological and toxicological studies on the effects and disposition of aldehydes.

Cellular and molecular effects of metronomic vinorelbine and 4-O-deacetylvinorelbine on human umbilical vein endothelial cells.

Metronomic oral vinorelbine (VRL; Navelbine) was shown in clinical trials to yield sustainable antitumor activity possibly through antiangiogenic mechanisms. We investigated the effects of protracted low-dose VRL on human umbilical vein endothelial cells, compared with a conventional chemotherapy model. Human umbilical vein endothelial cell cultures were treated with different concentrations of VRL (0.001 nmol/l to 1 mmol/l) for 4, 24 and 96 h. The effects of different drug concentrations on cell growth, cell cycle, apoptosis and expression of the angiogenesis-modulating genes interleukin-8, cyclooxygenase-2, CD36 and peroxisome proliferator-activated receptor γ were assessed using the metronomic or conventional chemotherapy model. Apoptosis and cell-cycle effects were assessed by flow cytometry. Gene expression was measured at the transcript level by quantitative reverse transcriptase-PCR, protein expression by immunoblotting and levels of proteins secreted in the cell medium by enzyme-linked immunosorbent assay. Activation of the nuclear factor-κB pathway was investigated by immunoblot analysis of cytosolic and nuclear protein extracts. The half-maximal inhibitory concentrations (IC50) of VRL at 96 h were four orders lower compared with those after a 24-h exposure (1.23 nmol/l vs. 32 mmol/l for VRL). Drug concentrations at high nanomolar levels and above, which are relevant to conventional pulsatile dosing of VRL, induced a dose-dependent and nuclear factor-κB-related increase in proangiogenic interleukin-8 and cyclooxygenase-2 and a decrease in the thrombospondin-1 receptor CD36 and peroxisome proliferator-activated receptor γ at mRNA and protein levels. In contrast, the opposite was evident with protracted picomolar to low nanomolar concentrations (metronomic dosing). Our data provide experimental support for metronomic VRL by showing that a protracted low dose outperforms pulsed high-dose administration in inducing antiangiogenic effects in proliferating human endothelial cells.

The Alcohol Intolerance Produced by Isoniazid Is Not Due to a Disulfiram-Like Reaction Despite Aldehyde Dehydrogenase Inhibition.

BACKGROUND/AIMS: Isoniazid (ISO) has been reported to inhibit the hepatic aldehyde dehydrogenase (ALDH) and to cause a disulfiram (DIS)-like reaction, albeit there are no reports demonstrating increased blood acetaldehyde levels after co-administration of ISO with alcohol. The aim of our study was to clarify whether the alcohol intolerance produced by ISO is indeed due to a typical DIS-like reaction. METHODS: DIS and ISO were administered to Wistar rats and the hepatic ethanol (ETH) metabolizing enzyme activities along with the levels of brain monoamines were determined. Blood acetaldehyde levels were also evaluated after co-administration of ETH with DIS or ISO. RESULTS: Despite inhibition of the hepatic ALDH, ISO did not result in elevated blood acetaldehyde levels after ETH administration, probably due to the induction of cytochrome P450 2E1 which theoretically leads to an increased elimination rate of acetaldehyde preventing its accumulation. Moreover, ISO produced some minor, but statistically significant, alterations in central monoaminergic neurotransmission. CONCLUSION: Our results demonstrate for the first time that despite ALDH inhibition ISO does not provoke a typical DIS-like reaction since it does not increase blood acetaldehyde levels after co-administration with ETH. The possibility that the ETH intolerance observed in ISO treatment is a central synergistic effect cannot be excluded.

Dose selection trial of metronomic oral vinorelbine monotherapy in patients with metastatic cancer: a hellenic cooperative oncology group clinical translational study.

BACKGROUND: Metronomic chemotherapy is considered an anti-angiogenic therapy that involves chronic administration of low-dose chemotherapy at regular short intervals. We investigated the optimal metronomic dose of oral vinorelbine when given as monotherapy in patients with metastatic cancer. METHODS: Patients with recurrent metastatic breast (BC), prostate (PC) or non-small cell lung cancer (NSCLC) and adequate organ functions were randomly assigned to 30, 40 or 50 mg vinorelbine, taken orally three times a week. Treatment continued until disease progression, unacceptable toxicity, withdrawal of consent or maximum 24 months. Primary endpoint was time-to-treatment failure (TTF) and secondary were progression-free survival (PFS), toxicity, changes in blood concentrations of angiogenesis-associated biomarkers and pharmacokinetics. RESULTS: Seventy-three patients were enrolled. Four-month TTF rate did not differ between the three arms: 25.9% (11.1%-46.2% 95% Confidence Interval), 33.3% (15.6%-55.3%) and 18.2% (5.2%-40.3%) for the 30 mg, 40 mg and 50 mg arms (p-value = 0.56). Objective response was seen in 2 patients with NSCLC (treated at 30 and 50 mg respectively), one with BC (at 40 m g) and one with PC (at 50 mg) and lasted from 4 to 100 weeks, with maximum response duration achieved at 50 mg. Adverse events were mild and negligible and did not differ between the three arms. Blood levels of vinorelbine reached steady state from the second week of treatment and mean values for the 30, 40 and 50 mg were respectively 1.8 ng/ml (SD 1.10), 2.2 ng/ml (SD 1.87) and 2.6 ng/ml (SD 0.69). Low pre-treatment blood concentrations of FGF2 and IL8 predicted favorable response to therapy (p values 0.02 and 0.006, respectively), while high levels of TEK gene transcript predicted treatment resistance. CONCLUSIONS: Considering the antitumor activity and response duration, the negligible toxicity of the highest dose investigated and the lack of drug accumulation over time, we suggest that 50 mg given three times a week is the optimal dose for metronomic oral vinorelbine. Further investigation of metronomic oral vinorelbine (MOVIN) at this dose is warranted in combination with conventional chemotherapy regimens and targeted therapies. TRIAL REGISTRATION: Clinicaltrials.gov NCT00278070.

Lab-on-a-screen-printed electrochemical cell for drop-volume voltammetric screening of flunitrazepam in untreated, undiluted alcoholic and soft drinks.

Flunitrazepam, also known as "Rohypnol" or "Rophy" among other trade and street names, is an extremely potent benzodiazepine that is prescribed to treat severe insomnia. Due to these attributes, flunitrazepam, when is surreptitiously administered to an alcoholic or soft drink, is associated with "drug-facilitated sexual assault". We report here for the first time, a low cost lab-on-a-screen-printed electrochemical cell (SPC) based on iron-sparked graphite working electrode modified with glucose oxidase (GOx) and glucose hydrogel droplets (GluHD) for the detection of flunitrazepam. Iron-spark modification increases the response of the sensor by ca. 3-fold compared with that of the plain electrode, while an in situ deoxygenation process, based on GOx-glucose enzyme reaction, depletes dissolved oxygen. As a result, the method enables interference free voltammetric measurements of the electro reduction of the nitro group of flunitrazepam at ca. -0.71 to -0.78 V vs. Ag printed pseudo reference electrode depending on the sample's matrix, and the detection of the drug at the sub-millimolar level. GOx/GluHD-FeSPC was directly applied to the drop-volume (∼60 µL) detection of flunitrazepam to a wide range of untreated and undiluted spiked samples (Pepsi cola®, Vodka, Whisky, Tequila, Gin, and Rum) of different acidity (pH 2.3-8.4), and alcohol content up to 40% v/v. Data demonstrate the excellent performance of the sensor for point-of-need screening of flunitrazepam and suggest that GOx/GluHD-FeSPC holds promise as an effective analytical tool to prevent phenomena of covert drug administration.

Vascular acrosyndromes in young adult population. Definition of clinical symptoms and connections to joint hypermobility.

OBJECTIVES: Clinical recognition of vascular acrosyndromes is often challenging. The term Raynaud's phenomenon (RP) is commonly overused to describe any form of cold-related disorder. This study aims to formally evaluate peripheral vascular symptoms affecting the population, aged ≤ 40 years, and identify any correlations to joint hypermobility (JH). PATIENTS AND METHODS: Fifty patients (31 males, 19 females) with vasomotor symptoms enrolled in this five-year prospective observational study. Clinical examination by a rheumatologist and a vascular surgeon was performed along with cardiology, echocardiographic and Doppler evaluation. Patients underwent blood cell count, biochemistry, thyroid and selectively immunologic testing. Twenty-four (48%) of them performed nailfold capillaroscopy. The SPSS for Windows, v.17.0, Chicago, USA, was used for the statistical analyses. RESULTS: Twenty-eight patients (56%) presented with erythromelalgia (EM), 6 (12%) with acrocyanosis (AC) and 9 (18%) as a combination of the above disorder. RP diagnosed in five (10%) while two patients (4%) presented as a mix of EM-RP. There was no correlation with abnormal laboratory tests. Increased incidence of JH was found in EM and AC patients. Among those who were tested with nailfold capillaroscopy, 75% had abnormalities ranged from mild to autoimmune-like diseases. CONCLUSIONS: Erythromelalgia is the commonest functional vasculopathy in young population followed by acrocyanosis and a combination of these conditions. Joint hypermobility is markedly increased, indicating that dysautonomy may be considered the causative factor following a trigger event. Overall, RP was observed in 14% of patients. Clinical recognition of these disorders avoids unnecessary investigation. Key Points • Vascular acrosyndromes in young adults are commonly functional disorders resembling vascular algodystrophy induced by thermic stress. • Dysautonomy of joint hypermobility is the co-factor influencing the appearance of the vascular disorders. • Raynaud's phenomenon accounts to approximately 14% of vascular acrosyndromes presented in the young adult population.

Impact of total PSA and percent free PSA in the differentiation of prostate disease: a retrospective comparative study implicating neoplastic and non-neoplastic entities.

PURPOSE: To evaluate the potential of prostate cancer detection on the basis of prostate-specific antigen (PSA)-level and percent free PSA (% fPSA) according to the outcome of prostate needle biopsy. METHODS: This was a retrospective study of 1040 patients that underwent a prostate biopsy in the Urologic Clinic of the University Hospital of Ioannina, Greece. The patients underwent needle biopsy after abnormal finding in digital rectal examination (DRE). Tissue samples were extracted using a 12-core TRUS-GB. The patients were divided into four groups according to the biopsy outcome. Total serum and free PSA were measured. RESULTS: The mean PSA concentration of cancer versus noncancer groups was significantly higher (p<0.05). The positive predictive value (PPV) of PSA for serum concentration >10 ng/ml was 47% while the negative predictive value (NPV) in patients with PSA levels <4 ng/ml was 81%. The diagnostic accuracy of % fPSA for patients with PSA level between 4-10 ng/ml was 0.651 (95% CI, 0.549-0.754) (p<0.05). A statistically significant difference in mean PSA concentration was recorded between prostate cancers classified as grade 2 (3+4=7) and 3 (4+3=7) and grade 4 (8) and 5 (9-10) (p<0.05). CONCLUSIONS: Though informative and suggestive, PSA and % fPSA are not definitive for cancer or non-cancer determination. The differentiation of PSA level between tumours classified as grade 2 (3+4=7) and grade 3 (4+3=7) could support the determination of treatment by backing pathologist's interpretation of the histological diagnosis.

A dose escalation and pharmacokinetic study of biweekly pegylated liposomal doxorubicin, paclitaxel and oxaliplatin in patients with advanced solid tumors.

PURPOSE: To evaluate the maximum tolerated doses (MTD) and the dose-limiting toxicities (DLT) of the combination of pegylated liposomal doxorubicin (PEG-LD), paclitaxel and oxaliplatin (L-OHP) administered every 2 weeks in patients with advanced solid tumors. METHODS: Thirty-nine pretreated patients with advanced solid tumors received escalated doses of PEG-LD (10-16 mg/m(2)), paclitaxel (100-120 mg/m(2)) and L-OHP (50-70 mg/m(2)) every 2 weeks. As one cycle of treatment was considered the administration of both drugs on days 1 and 15 of a 4-week cycle. RESULTS: The MTDs were PEG-LD 14 mg/m(2), paclitaxel 120 mg/m(2) and L-OHP 70 mg/m(2). Neutropenia was the DLT in all but one case with only one episode of febrile neutropenia and no toxic deaths. Four (4%) and 13 (12%) cycles were complicated by grades 4 and 3 neutropenia, respectively. Grades 2-3 fatigue and neurotoxicity occurred in 13 and 12% of cycles, respectively. Responses were observed in patients with breast, endometrial and ovarian carcinomas. CONCLUSIONS: This is a quite well-tolerated regimen which merits further evaluation in phase II studies.

Metronomic chemotherapy: A potent macerator of cancer by inducing angiogenesis suppression and antitumor immune activation.

Metronomic chemotherapy is a low dosing treatment strategy that attracts growing scientific and clinical interest. It refers to dense and uninterrupted administration of low doses of chemotherapeutic agents (without prolonged drug free intervals) over extended periods of time. Cancer chemotherapy is conventionally given in cycles of maximum tolerated doses (MTD) with the aim of inducing maximum cancer cell apoptosis. In contrast, the primary target of metronomic chemotherapy is the tumor's neovasculature. This is relevant to the emerging concept that tumors exist in a complex microenvironment of cancer cells, stromal cells and supporting vessels. In addition to its anti-angiogenetic properties, metronomic chemotherapy halts tumor growth by activating anti-tumor immunity, thus decreasing the acquired resistance to conventional chemotherapy. Herein, we present a review of the literature that provides a scientific basis for the merits of chemotherapy when administered on a metronomic schedule.

Growth rate effects, responses of antioxidant enzymes and metabolic fate of the herbicide Propanil in the aquatic plant Lemna minor.

Propanil (3,4-dichloropropionanilide) is a selective contact pesticide, recommended for post-emergence use in rice. This herbicide may end up in surface waters and present potential risk for aquatic vascular plants. Therefore, its toxicity was evaluated on Lemna minor L., an aquatic plant regularly used for toxicological studies, during time- and concentration-dependent exposure. Toxicity assessments were based on inhibition of growth of L. minor cultures after 24 days. The obtained results showed that the growth of Lemna was affected by the herbicide. The responses of the guaiacol peroxidase (G-POD) and glutathione S-transferase (GST) involved in the xenobiotic metabolism and antioxidative system were also investigated following Propanil exposure. Our results showed that Propanil has not induced enzymatic antioxidative defenses of L. minor. Both 3,4-dichloroaniline (3,4-DCA) and 3,4-dichloroacetanilide are the major metabolites in this plant. On the contrary, only 3,4-DCA was found in culture media after 4 days. Probably, the enzymatic hydrolysis by acyl acylamidase and the acetylation by acetyl-CoA are the major pathways for these transformation products, respectively. The results of this study showed that the selected aquatic plant has the potential to accumulate and metabolize rice herbicide, like Propanil. Based on these toxicity data this herbicide should impair the establishment of non-target aquatic plants.

Pharmacokinetics of imatinib mesylate in end stage renal disease. A case study.

AIM: To evaluate the pharmacokinetics of imatinib mesylate (Glivec) and its main metabolite (CGP74588) in a patient with end stage renal disease on hemodialysis and compare it with published data from subjects with normal renal function. PATIENTS AND METHODS: Serial blood samples were collected over a 2-weeks period in a patient who was receiving daily 400 mg oral imatinib mesylate for the treatment of a gastrointestinal stromal tumor metastatic to the liver while on hemodialysis. Plasma levels of imatinib and CGP74588 were determined by a liquid chromatography-tandem mass spectrometry assay. RESULTS: The pharmacokinetic values for imatinib and CGP74588, respectively, were: maximum concentration (3,340 and 781 ng/ml), time to maximum concentration (2 h), half-life (18.2 and 34.0 h), area under the curve (53.9 and 14.8 microg.h/ml), and trough concentration (1,540 and 508 ng/ml) for at least 24 h. All obtained values fell within the range of values of imatinib and its metabolite obtained in patients with normal renal function. Dialysis courses were not found to intervene with plasma kinetics of the study drug. CONCLUSIONS: Our results indicate that the pharmacokinetics of imatinib and its metabolite CGP74588 do not change in patients with end stage renal disease on hemodialysis. Thus, the standard dose of imatinib can be safely administered to patients on hemodialysis, and probably with renal failure, at any stage.

"Toothbrush" the Feet: A Periodic Mechanical Stimulus for Healing of a Severe Chronic Leg Ulcer.

Chronic wounds develop when the sequence of healing events are disrupted, usually in patients with underlying diseases such as diabetes mellitus, venous insufficiency, peripheral artery disease, and neuropathies and they affect most often the lower extremities. We present a 68-year-old woman with plantar ulceration, lasting for approximately 18 months, resistant to healing with conventional therapy and various modalities we used. The patient had a long history of seronegative enteropathic arthritis, Crohn's disease, secondary fibrillar amyloidosis, multiplex neuropathy, and small vessel vasculitis, the latter being the trigger event for the ulceration of her right foot. Before the decision for a final surgical intervention, we implemented a mechanical periodic stimulus using a soft toothbrush, which resulted in the gradual and complete healing of the ulcer within a period of 6 weeks. Patient's history and previous treatments are presented along with the procedures that led to the healing of the chronic wound. This report supports the idea that periodic mechanical stimulus is of great importance for the healing process and this could be the mechanism of action of some other methods that have been described in the medical literature.

Expression Profile of Genes Related to Drug Metabolism in Human Brain Tumors.

BACKGROUND: Endogenous and exogenous compounds as well as carcinogens are metabolized and detoxified by phase I and II enzymes, the activity of which could be crucial to the inactivation and hence susceptibility to carcinogenic factors. The expression of these enzymes in human brain tumor tissue has not been investigated sufficiently. We studied the association between tumor pathology and the expression profile of seven phase I and II drug metabolizing genes (CYP1A1, CYP1B1, ALDH3A1, AOX1, GSTP1, GSTT1 and GSTM3) and some of their proteins. METHODS: Using qRT-PCR and western blotting analysis the gene and protein expression in a cohort of 77 tumors were investigated. The major tumor subtypes were meningioma, astrocytoma and brain metastases, -the later all adenocarcinomas from a lung primary. RESULTS: Meningeal tumors showed higher expression levels for AOX1, CYP1B1, GSTM3 and GSTP1. For AOX1, GSTM and GSTP1 this could be verified on a protein level as well. A negative correlation between the WHO degree of malignancy and the strength of expression was identified on both transcriptional and translational level for AOX1, GSTM3 and GSTP1, although the results could have been biased by the prevalence of meningiomas and glioblastomas in the inevitably bipolar distribution of the WHO grades. A correlation between the gene expression and the protein product was observed for AOX1, GSTP1 and GSTM3 in astrocytomas. CONCLUSIONS: The various CNS tumors show different patterns of drug metabolizing gene expression. Our results suggest that the most important factor governing the expression of these enzymes is the histological subtype and to a far lesser extent the degree of malignancy itself.

Involvement of the brain serotonergic system in the locomotor stimulant effects of chlorpheniramine in Wistar rats: implication of postsynaptic 5-HT1A receptors.

Antihistamines, such as chlorpheniramine (CPA), are lipophilic agents which readily cross the blood-brain barrier, producing sedation in 10-25% of users. However, with excessive doses instead of sedation a stimulating action has been reported. The aim of the present study was to investigate the influence of CPA on the locomotor activity of the rat in relation to its effects on brain biogenic monoamines. Wistar rats were given CPA (40 mg/kg, i.p.) and locomotor activity was measured in a photocell cage. Body temperature was also monitored. In addition, in three brain subregions (striatum, hypothalamus, and midbrain), the levels of 5-HT, NA, DA, as well as their metabolites, were determined by HPLC. Soon after injection, CPA produced a significant increase in locomotor activity, while a hypothermic response was also induced. In striatum and hypothalamus, which are known to be rich in postsynaptic 5-HT1A receptors, we found a significant time-dependent increase of 5-HT, correlated with the clearly enhanced locomotor activity of the animals. On the contrary, in midbrain, where presynaptic 5-HT1A receptors are dominating, no changes could be detected in 5-HT. In all three brain regions measured, 5-HIAA levels were decreased. The levels of the other brain monoamines were only marginally affected. In support of a role in receptor specificity, pretreatment with the 5-HT1A receptor agonist 8-OH-DPAT (1.25 mg/kg, i.p., two times) or with the 5-HT(1A/B) receptor antagonist pindolol (30 mg/kg, i.p., two times), enhanced or blocked, respectively, the hyperlocomotion induced by CPA. These findings suggest that the central serotonergic system may play a key role in the locomotor stimulant effects of CPA in the rat. Moreover, this behavioral component of CPA seems to be primarily mediated via the postsynaptic 5-HT1A receptors.

Acute-phase response to benzo[a]pyrene and induction of rat ALDH3A1.

The aldehyde dehydrogenase-3A1 (ALDH3A1) enzyme, encoded by a member of the [Ah]-gene family, is dramatically increased (more than 100-fold) by benzo[a]pyrene (BaP) and other polycyclic hydrocarbons. Although much is known regarding the mechanism for the drug-metabolizing enzymes up-regulated by the Ah receptor, the physiological role of that tremendously increased ALDH3A1 enzyme activity is not yet fully clarified. The aim of this study was to identify a possible acute-phase response to different classes of xenobiotics affecting the metabolic capacity of the hepatocyte, by studying possible changes of serum acute-phase proteins (APPs) of hepatic origin, before and after BaP administration. Male Wistar rats were used in different series of experiments. The effects of BaP were estimated in terms of dose-response and time-response, with regard to the serum level of several APPs such as alpha-1-acid-glycoprotein (AAG), alpha-1-antitrypsin (AAT), C-reactive protein (CRP), and haptoglobin (HPT). In parallel experiments, levels of the same proteins have been determined after a time-dependent treatment with lipopolysaccharide (LPS). The changes in serum proteins were compared with the results of BaP or LPS administration on both hepatic ALDH3A1 and total ALDH enzyme activities. The results showed that BaP induced CRP and HPT in a time-dependent way, proportional to that caused by LPS. Additionally, ALDH3A1, CRP, and HPT were induced by BaP subacute treatment, whereas another type of ALDH inducer, phenobarbital, did not affect the levels of APPs or ALDH3A1, but did increase ALDH1A3 activity. Former studies of our group have shown that the inhibitory effects of different non-steroidal anti-inflammatory drugs (NSAIDs) on the ALDH3A1 induction were most possibly due to a decreased formation of arachidonic products like prostaglandins. Considering the changes of APPs caused by BaP, this study further supports the suggestion that the induction of ALDH3A1 is related to an atypical hepatocyte inflammation produced by xenobiotics.

A collaborative evaluation of the cytotoxicity of two surfactants by using the human corneal epithelial cell line and the WST-1 test.

This study was undertaken to investigate the use of the in vitro test WST-1, an assay of cell proliferation and viability, for a preliminary safety evaluation of topical ophthalmic preparations. The cytotoxicity of two surfactants, benzalkonium chloride (BAC) and polyoxyethylene-20-stearyl ether (Brij78, PSE) was independently investigated in four laboratories in the EU by using an immortalized human corneal epithelial (HCE) cell line. The HCE cells were exposed to BAC and PSE for 5 min, 15 min, and 1 hour, and the results of the HCE-WST-1 tests were collected and compared. After one-hour exposure, the EC(50) values in BAC-treated cells in the presence of serum ranged between 0.0650 +/- 0.0284 (mean +/- SD) mM, and those in the absence of serum 0.0296 +/- 0.0081 mM. The corresponding values for PSE were 0.0581 +/-.0300 mM and 0.0228 +/-.0063 mM. There were variations in the results between different laboratories, with coefficients of variation ranging from 31 to 121%, mean 58%. The use of one-hour exposure time is to be preferred, and the elimination of serum in the culture medium is recommended to avoid both underestimation of toxic effects and variability of the test results.