Levofloxacin versus azithromycin for treating legionella pneumonia: a propensity score analysis

OBJECTIVES

Concerns have arisen regarding the equivalence of levofloxacin and some macrolides for treating community-acquired legionella pneumonia (LP). We aimed to compare the outcomes of current patients with LP treated with levofloxacin, azithromycin and clarithromycin.

METHODS

Observational retrospective multicentre study of consecutive patients with LP requiring hospitalization (2000-2014) conducted in two hospitals. The primary outcome assessed was 30-day mortality. To control for confounding, therapy was assessed by multivariate analysis.

RESULTS

We documented 446 patients with LP, of which 175 were treated with levofloxacin, 177 with azithromycin and 58 with clarithromycin. No significant differences in time to defervescence (2 (interquartile range (IQR) 1-4) versus 2 (IQR 1-3) days; p 0.453), time to achieve clinical stability (3 (2-5) versus 3 (2-5) days; p 0.486), length of intravenous therapy (3 (2-5.25) versus 4 (3-6) days; p 0.058) and length of hospital stay (7 (5-10) versus 6 (5-9) days; p 0.088) were found between patients treated with levofloxacin and those treated with azithromycin. Patients treated with clarithromycin had longer intravenous antibiotic treatment (3 (2-5.25) versus 5 (3-6.25) days; p 0.002) and longer hospital stay (7 (5-10) versus 9 (7-14) days; p 0.043) compared with those treated with levofloxacin. The overall mortality was 4.3% (19 patients). Neither univariate nor multivariate analysis showed a significant association of levofloxacin versus azithromycin on mortality (4 (2.3%) versus 9 (5.1%) deaths; p 0.164). The results did not change after incorporation of the propensity score into the models.

CONCLUSIONS

In our study, no significant differences in most outcomes were found between patients treated with levofloxacin and those treated with azithromycin. Due to the small number of deaths, results regarding mortality should be interpreted with caution.

ICRP Publication 131: Stem Cell Biology with Respect to Carcinogenesis Aspects of Radiological Protection

This report provides a review of stem cells/progenitor cells and their responses to ionising radiation in relation to issues relevant to stochastic effects of radiation that form a major part of the International Commission on Radiological Protection's system of radiological protection. Current information on stem cell characteristics, maintenance and renewal, evolution with age, location in stem cell 'niches', and radiosensitivity to acute and protracted exposures is presented in a series of substantial reviews as annexes concerning haematopoietic tissue, mammary gland, thyroid, digestive tract, lung, skin, and bone. This foundation of knowledge of stem cells is used in the main text of the report to provide a biological insight into issues such as the linear-no-threshold (LNT) model, cancer risk among tissues, dose-rate effects, and changes in the risk of radiation carcinogenesis by age at exposure and attained age. Knowledge of the biology and associated radiation biology of stem cells and progenitor cells is more developed in tissues that renew fairly rapidly, such as haematopoietic tissue, intestinal mucosa, and epidermis, although all the tissues considered here possess stem cell populations. Important features of stem cell maintenance, renewal, and response are the microenvironmental signals operating in the niche residence, for which a well-defined spatial location has been identified in some tissues. The identity of the target cell for carcinogenesis continues to point to the more primitive stem cell population that is mostly quiescent, and hence able to accumulate the protracted sequence of mutations necessary to result in malignancy. In addition, there is some potential for daughter progenitor cells to be target cells in particular cases, such as in haematopoietic tissue and in skin. Several biological processes could contribute to protecting stem cells from mutation accumulation: (a) accurate DNA repair; (b) rapidly induced death of injured stem cells; (c) retention of the DNA parental template strand during divisions in some tissue systems, so that mutations are passed to the daughter differentiating cells and not retained in the parental cell; and (d) stem cell competition, whereby undamaged stem cells outcompete damaged stem cells for residence in the niche. DNA repair mainly occurs within a few days of irradiation, while stem cell competition requires weeks or many months depending on the tissue type. The aforementioned processes may contribute to the differences in carcinogenic radiation risk values between tissues, and may help to explain why a rapidly replicating tissue such as small intestine is less prone to such risk. The processes also provide a mechanistic insight relevant to the LNT model, and the relative and absolute risk models. The radiobiological knowledge also provides a scientific insight into discussions of the dose and dose-rate effectiveness factor currently used in radiological protection guidelines. In addition, the biological information contributes potential reasons for the age-dependent sensitivity to radiation carcinogenesis, including the effects of in-utero exposure.

Patient satisfaction with the clinical pharmacist and prescribers during hepatitis C virus management

WHAT IS KNOWN AND OBJECTIVES

Clinical pharmacists play an important role in the management of patients undergoing hepatitis C virus (HCV) treatment. No satisfaction surveys have been published on clinical pharmacist interventions in HCV management. The objective was to evaluate patient satisfaction with clinical pharmacist and prescriber services in the HCV patient population at an urban academic hepatology clinic.

METHODS

An anonymous patient satisfaction survey was offered to patients who were initiating or receiving HCV treatment under the care of a clinical pharmacist. Survey items assessed demographics and satisfaction with HCV care. Satisfaction was assessed with 17 or 20 Likert-scale questions (1 = poor, 2 = fair, 3 = okay, 4 = good, 5 = great) and two or three open-ended questions. Survey results were analysed via comparative and descriptive statistics. A qualitative content analysis was used for the open-ended survey questions.

RESULTS AND DISCUSSION

Sixty-four patients completed 77 (24 pharmacist and 53 prescriber) patient satisfaction surveys. The mean age was 53 (±9·72) years. Patients reported high levels of satisfaction with the pharmacist and prescribers. All 24 (100%) patients ranked overall satisfaction with services provided by pharmacists as 'great', and 36 (69%) of 52 patients ranked overall satisfaction with services provided by prescribers as 'great'. Patients supported the inclusion of a clinical pharmacist on health care teams for other disease states.

WHAT IS NEW AND CONCLUSION

Patients reported high levels of satisfaction with the clinical pharmacist involved in HCV treatment management at an urban academic medical centre. Clinical pharmacist services were highly valued and recommended by the patients surveyed. The survey was able to identify areas in need of improvement in the clinic. Clinical pharmacists play an important role in the treatment and management of HCV. This survey may serve as a model for assessment of satisfaction in other pharmacist-run clinic settings.

ICRP Publication 131: Stem cell biology with respect to carcinogenesis aspects of radiological protection

Current knowledge of stem cell characteristics, maintenance and renewal, evolution with age, location in 'niches', and radiosensitivity to acute and protracted exposures is reviewed regarding haematopoietic tissue, mammary gland, thyroid, digestive tract, lung, skin, and bone. The identity of the target cells for carcinogenesis continues to point to the more primitive and mostly quiescent stem cell population (able to accumulate the protracted sequence of mutations necessary to result in malignancy), and, in a few tissues, to daughter progenitor cells. Several biological processes could contribute to the protection of stem cells from mutation accumulation: (1) accurate DNA repair; (2) rapid induced death of injured stem cells; (3) retention of the intact parental strand during divisions in some tissues so that mutations are passed to the daughter differentiating cells; and (4) stem cell competition, whereby undamaged stem cells outcompete damaged stem cells for residence in the vital niche. DNA repair mainly operates within a few days of irradiation, while stem cell replications and competition require weeks or many months depending on the tissue type. This foundation is used to provide a biological insight to protection issues including the linear-non-threshold and relative risk models, differences in cancer risk between tissues, dose-rate effects, and changes in the risk of radiation carcinogenesis by age at exposure and attained age.

Potential role of the gaseous mediator hydrogen sulphide (H2S) in inhibition of human colonic contractility

BACKGROUND

Hydrogen sulphide (H2S) is an endogenous signalling molecule that might play a physiologically relevant role in gastrointestinal motility. Cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) are two enzymes responsible for H2S production. d,l-Propargylglycine (PAG) is a CSE inhibitor whereas both aminooxyacetic acid (AOAA) and hydroxylamine (HA) are CBS inhibitors. The characterization of H2S responses and its mechanism of action are crucial to define H2S function.

METHODS

Human colonic strips were used to investigate the role of H2S on contractility (muscle bath) and smooth muscle electrophysiology (microelectrodes). NaHS was used as a H2S donor.

RESULTS

Combination of PAG and AOAA depolarized the smooth muscle (5-6mV, n=4) and elicited a transient increase in tone (260.5±92.8mg, n=12). No effect was observed on neural mediated inhibitory junction potential or relaxation. In the presence of tetrodotoxin 1μM, NaHS concentration-dependently inhibited spontaneous contractions (EC50=329.2μM, n=18). This effect was partially reduced by the guanylyl cyclase inhibitor ODQ 10μM (EC50=2.6μM, n=12) and by l-NNA 1mM (EC50=1.4mM, n=8). NaHS reversibly blocked neural mediated cholinergic (EC50=2mM) and tachykinergic (EC50=5.7mM) contractions. NaHS concentration-dependently reduced the increase in spontaneous mechanical activity (AUC) induced by carbachol (EC50=1.9mM) and NKA (EC50=1.7mM AUC).

CONCLUSIONS

H2S might be an endogenous gasomediator regulating human colonic contractility. Its inhibitory effect is observed at high concentrations and could be mediated by a direct effect on smooth muscle with a possible synergistic effect with NO, as well as by an interaction with the cholinergic and tachykinergic neural mediated pathways.

Functional interplay between p63 and p53 controls RUNX1 function in the transition from proliferation to differentiation in human keratinocytes

The interfollicular epidermis is continuously renewed, thanks to a regulated balance between proliferation and differentiation. The ΔNp63 transcription factor has a key role in the control of this process. It has been shown that ΔNp63 directly regulates Runt-related transcription factor 1 (RUNX1) transcription factor expression in mouse keratinocytes. The present study showed for the first time that RUNX1 is expressed in normal human interfollicular epidermis and that its expression is tightly regulated during the transition from proliferation to differentiation. It demonstrated that ΔNp63 directly binds two different RUNX1 regulatory DNA sequences and modulates RUNX1 expression differentially in proliferative or differentiated human keratinocytes. It also showed that the regulation of RUNX1 expression by ΔNp63 is dependent on p53 and that this coregulation relies on differential binding and activation of RUNX1 regulatory sequences by ΔNp63 and p53. We also found that RUNX1 inhibits keratinocyte proliferation and activates directly the expression of KRT1, a critical actor in early keratinocyte differentiation. Finally, we described that RUNX1 expression, similar to ΔNp63 and p53, was strongly expressed and downregulated in basal cell carcinomas and squamous cell carcinomas respectively. Taken together, these data shed light on the importance of tight control of the functional interplay between ΔNp63 and p53 in regulating RUNX1 transcription factor expression for proper regulation of interfollicular epidermal homeostasis.

Ileal inducible nitric oxide synthase mRNA expression in response to stress is modified in Sprague-Dawley rats exposed to a previous intestinal inflammation

The ability of stress to initiate or reactivate an inflammatory process seems to depend on an individual's susceptibility to stressful stimuli. The aim of this study was to establish whether previous inflammation alters the response to stress in Sprague-Dawley rats, a strain not especially susceptible to stressful stimuli. Stress exposure was performed in rats treated with indomethacin, to induce cyclic intestinal inflammation, during the inactive phase of inflammation. Both control and indomethacin-treated rats submitted to stress showed a decrease in body weight gain and blood leukocyte levels, as well as an increase in fecal pellet output. The increase in intestinal mucosal mast cell count induced by stress was similar in both groups of animals. Moreover, no differences were observed between control and indomethacin-treated rats in the degree of bacterial translocation and myeloperoxidase levels after stress exposure. Despite these similarities, differences between groups were observed in inducible nitric oxide synthase (iNOS) mRNA expression. Although ileal iNOS mRNA expression was inhibited in healthy rats submitted to stress, stress failed to modify this parameter in indomethacin-treated rats. As iNOS is another inflammatory marker, our results may allow the possibility that a previous intestinal inflammation could change the intestinal susceptibility to stress. Whether these differences in ileal iNOS expression can be indicative of a possible change in the predisposition to develop an intestinal inflammatory reaction in response to stress in Sprague-Dawley rats remains to be elucidated.

First Report of Neofusicoccum mediterraneum and N. australe Causing Decay in Vitis vinifera in Castilla y León, Spain

During a survey for grapevine decline, five young grapevines (cvs. Tempranillo and Viura) with low vigor and reduced foliage were collected (June and August 2009). Fungal isolations were performed from vascular and brown wood. Small pieces of brown wood were placed onto malt extract agar supplemented with 0.25 g/liter of chloramphenicol and incubated at 25°C in darkness. Five resulting colonies were transferred to potato dextrose agar (PDA). Isolates were characterized by abundant, gray, aerial mycelium that reached a radius of 45 mm after 4 days. Pycnidia induced on water agar with pine needles and UV light contained conidia that were hyaline, smooth, thin walled, fusiform, (20-) 22 to 26 (-28) × (5.5-) 6 (-6.5) μm, with granular cytoplasm. On the basis of morphological characteristics Neofusicoccum mediterraneum was suspected (1). Single-conidial cultures were generated from each isolate. DNA analyses were described in Martin and Cobos (2). Sequences of the internal transcribed spacer (ITS) region confirmed the identification and revealed 99% genetic identity with N. mediterraneum (GenBank Accession No EU040221). A sequence of the ITS fragment was deposited with Accession No. JF437919. Partial sequences of β-tubulin and 1-α elongation factor genes were amplified and deposited in the GenBank with Accession Nos. JF437921 and JF437923, showing 100 and 99% similarity to Accession Nos. GU292786 and GU251350, respectively. Pathogenicity tests were conducted with two isolates. The inoculations were carried out on a fresh wound on which an agar plug was applied; on 110R-rootstock woods of 12 young vines with N. mediterraneum and 12 other control plants were treated with agar only. Grapevines were maintained in a greenhouse at 20 to 25°C. After 4 months, N. mediterraneum was reisolated from vascular and brown tissues in 92% of inoculated plants, fulfilling Koch's postulates. Control plants were asymptomatic and N. mediterraneum was not recovered. With the same methodology, isolate Y264-21-1 reached a radius of 43 mm after 4 days at 25°C on PDA, presented colonies becoming olivaceous with a moderately dense mycelia, mat in center, and aerial around. Conidia were hyaline, fusiform, base subtruncate (19-) 23 to 26 (-31) × 5 to 6 (7.5) μm, unicellular, and smooth with granular contents. Based on these descriptions, N. australe was suspected (3). ITS sequence comparison revealed 99% genetic identity with N. australe (Accession No. FJ150697), a sequence of the fragment was deposited with Accession No. JF437920. Partial sequences of β-tubulin and 1α-elongation factor were deposited in the GenBank (Accession Nos. JF437922 and JF437924) showing 100 and 99% similarity to Accession Nos. AY615149 and GU251352, respectively. Koch's postulates were completed as described above. After 4 months, N. australe was reisolated from internal brown lesions in 92% of inoculated plants. Control plants were asymptomatic and N. australe was not recovered. The streaking length average from inoculation point for N. mediterraneum was 42 ± 22 mm and 53 ± 7 mm for N. australe. To our knowledge this is the first report of N. mediterraneum and N. australe in Castilla y León (Spain). References: (1) P. W. Crous et al. Fungal Planet 19:2, 2007. (2) M. T. Martin and R. Cobos. Phytopathol. Mediterr. 46:18, 2007. (3) B. Slippers et al. Mycologia 96:1030, 2004.

First Report of Cylindrocarpon pauciseptatum Associated with Grapevine Decline from Castilla y León, Spain

During a survey for grapevine decline, 10 young grapevines (cvs. Tempranillo and Verdejo) with low vigor and little foliage were collected between June 2008 and August 2009. Small pieces of vascular and brown wood were placed onto malt extract agar supplemented with 0.25 g/liter of chloramphenicol and incubated at 25°C. Fifteen resulting colonies were transferred to potato dextrose agar in petri dishes (90 mm). Colonies with white mycelium covered the dishes after 10 days of incubation at 25°C in darkness; mycelium gradually became yellowish with some brownish aspect. Macroconida were predominantly three septate (40 to 45 to 50 × 8.6 to 9 to 9.5 μm with a length and width ratio of 4.7 to 5 to 5.4), straight, and cylindrical with both ends broadly rounded. Chlamydospora and ovoidal microconidia were observed on synthetic nutrient-poor agar (1). Cylindrocarpon pauciseptatum was not easy to distinguish from other Cylindrocarpon species based on morphological characteristics. Ribosomal internal transcribed spacer region sequences of single-spore cultures confirmed the morphological identification and revealed 100% genetic identity with other isolates of C. pauciceptatum present in GenBank (EF607090), a sequence of the fragment was deposited with Accession No. EU983277. Pathogenicity tests were conducted with two isolates. The inoculations were done on 110R rootstock wood of four different young plants and 15 detached canes of current-season growth (cv. Tempranillo). Plants were inoculated with an agar plug containing C. pauciceptatum; controls were treated with agar only. Grapevines were maintained in a greenhouse at 20 to 25°C. After 3 to 4 months, C. pauciceptatum was reisolated from brown tissues and internal vascular lesions in 45% of inoculated samples, fulfilling Koch's postulates. Control plants were asymptomatic and C. pauciceptatum was not recovered. To our knowledge, this is the first report implicating C. pauciceptatum as a cause of grapevine black foot disease in Spain with potentially significant impact on grapevine nurseries. Reference: (1) H. J. Schroers et al. Mycol. Res. 112:82, 2008.

Treatment with LA-419 prevents monocrotaline-induced pulmonary hypertension and lung injury in the rat

We evaluated the therapeutic potential of LA-419, a hybrid organic nitrate that donates nitric oxide and thiol groups, to improve pulmonary arterial hypertension in an experimental model induced by monocrotaline in the rat. Treatment with LA-419 from the first day after monocrotaline administration prevented the increase in pulmonary pressure as well as the increases in ventricle/body weight and pulmonary artery wall thickness. Administration of LA-419 after establishment of hypertensive status also resulted in an improvement of these parameters. Both preventive and therapeutic treatments reduced mortality. The antioxidant effect of LA-419 was comparable to that achieved with a-tocopherol. Pulmonary remodeling accomplished by LA-419 could be attributed to a balanced antioxidant effect associated with its nitric oxide/SH donor capability. Thus, LA-419 might represent a new therapeutic approach in severe pulmonary hypertension in humans.

Development and validation of a liquid chromatography-fluorescence-mass spectrometry method to measure glyphosate and aminomethylphosphonic acid in rat plasma

A simple and fast method has been developed and validated to measure glyphosate (GLYP) and aminomethylphosphonic acid (AMPA) in rat plasma based on reversed-phase high performance liquid chromatography (RP-HPLC) coupled to fluorescence (FLD) and electrospray ionization mass spectrometry (ESI-MS) detection. After protein precipitation with acetonitrile, GLYP and AMPA were derivatized with 9-fluorenylmethylchloroformate (FMOC-Cl) and then separated on a C(12) column (250mm×4.60mm i.d.) using a gradient of an ammonium formate (20mM, pH 8.5) and acetonitrile mobile phase. Selected ion monitoring (SIM) mode of the MS was used to obtain maximum sensitivity when quantifying GLYP and AMPA. The validation shows the method to be consistent and reliable, with an intra- and inter-day precision for GLYP and AMPA>9% for both detectors. For both compounds the accuracy ranged from 2.1% to 7.8% for the intra-day readings, and from 4.1% to 8.6% for the inter-day values. The efficacy of GLYP extraction ranged from 87% to 93% and it was between 76% and 88% for AMPA. Moreover, the limits of quantification (LOQ) for GLYP and AMPA were 5 and 10ng/mL, respectively with FLD, and 0.4 and 2ng/mL with ESI-MS. The method was successfully applied to simultaneously measure both compounds in rat plasma samples several days after oral administration of glyphosate.

Functional changes induced by psychological stress are not enough to cause intestinal inflammation in Sprague-Dawley rats

BACKGROUND

It is well known that stress contributes to the perpetuation of several gastrointestinal diseases. However, its role as a trigger of the inflammatory process in absence of other putative contributing factors remains controversial. Our aim was to elucidate whether stress per se can induce a primary gut inflammation in non-predisposed rats.

METHODS

Male Sprague-Dawley rats were divided in sham and stress groups. Chronic stress was induced by subjecting animals 1 h day(-1) to wrap restraint or water avoidance stress alternatively for five consecutive days, as a model of ongoing life stress.

KEY RESULTS

Chronic stress induced a significant decrease in body weight gain without changes in food intake and an increase in frequency of defecation. Electromiografic (EMG) study showed that the duration of the migrating motor cycles (MMCs), but not its frequency, was shortened in stressed animals compared with non-stress conditions. Moreover, stressful stimulus caused mucosal mast cell hyperplasia and a decrease of iNOS mRNA expression. Bacterial translocation observed in stressed animals was not related to changes in epithelial barrier function and was not enough to induce intestinal inflammation.

CONCLUSIONS & INFERENCES

Decreased MMC duration, mast cell hyperplasia and decreased mRNA iNOS expression, but not altered epithelial barrier function, could be factors implicated in bacterial translocation-induced by chronic stress. However, these changes are not sufficient to induce intestinal inflammation in stress non-susceptible strain of rats.

Toxicokinetics of glyphosate and its metabolite aminomethyl phosphonic acid in rats

The toxicokinetics of glyphosate after single 100 mgkg(-1) intravenous (i.v.) and 400 mgkg(-1) oral doses were studied in rats. Serial blood samples were obtained after i.v. and oral administration. Plasma concentrations of glyphosate and its metabolite amiomethyl phosphonic acid (AMPA) were determined by HPLC method. After i.v. and oral administration, plasma concentration-time curves were best described by a two-compartment open model. For glyphosate, the elimination half-lives (T(1/2beta)) from plasma were 9.99 h after i.v. and 14.38 h after oral administration. The total plasma clearance was not influenced by dose concentration or route and reached a value of 0.995 l h(-1)kg(-1). After i.v. administration, the apparent volume of distribution in the second compartment (V(2)) and volume of distribution at steady state (V(ss)) were 2.39 and 2.99 l kg(-1), respectively, suggesting a considerable diffusion of the herbicide into tissues. After oral administration, glyphosate was partially and slowly absorbed with a T(max) of 5.16 h. The oral bioavailability of glyphosate was found to be 23.21%. Glyphosate was converted to AMPA. The metabolite AMPA represented 6.49% of the parent drug plasma concentrations. The maximum plasma concentrations of glyphosate and AMPA were 4.62 and 0.416 microg ml(-1), respectively. The maximum plasma concentration of AMPA was achieved at 2.42 h. For AMPA, the elimination half-life (T(1/2beta)) was 15.08 h after oral administration of glyphosate parent compound.

First Report of Lasidiplodia theobromae and Cryptovalsa ampelina Associated with Grapevine Decline from Castilla y León, Spain

Symptoms of grapevine decline were surveyed. Samples from mature vines exhibiting external symptoms of Eutypa dieback and Esca were collected, as were young plants with and without external symptoms, and fungal isolations were performed. In 2007, 3-year-old grapevines (cv. Tempranillo grafted onto 110R rootstock) with low vigor, reduced foliage, and vascular streaking in the wood were observed. Small pieces of discolored wood were placed onto malt extract agar supplemented with 0.25 g/liter of chloramphenicol, incubated at 25°C, and resulting colonies were transferred to potato dextrose agar (PDA). Isolates were characterized by abundant aerial and fast-growing mycelium covering the plate surface after 3 days, mycelium became dark green. Pycnidia contained thick-walled, aseptate conidia 15 to 35 × 10 to 15 μm. Lasidiplodia theobromae was identified based on morphological characteristics (3) and confirmed by banding patterns obtained after the digestion of the 1,200-bp amplicon generated with ITS1 and NL4 primers (2) using restriction endonucleases (2). Single-spore cultures were generated and DNA sequences of the rDNA internal transcribed spacer region, partial sequence of the 5' end of the β-tubulin gene, and a fragment of the elongation factor further confirmed the identification and revealed genetic similarity with other isolates of L. theobromae. A sequence of each fragment was deposited in GenBank with Accession Nos. EU600925, EU597297, and EU597298, respectively. Pathogenicity tests were conducted on four replicate rootstocks (110R) and 15 canes of current-season growth (cv. Tempranillo). Plants were inoculated with an agar plug containing L. theobromae; controls were treated with agar only. Grapevines were maintained in a greenhouse at 20 to 25°C. After 3 months, L. theobromae was reisolated from internal vascular lesions in 100 and 66% of inoculated rootstocks and canes, respectively. Control plants were asymptomatic and L. theobromae was not recovered. Using the same methodology, a fungus identified based on morphological characteristics in culture as Cryptovalsa ampelina (1) was isolated from grapevines (cv. Tempranillo) planted in 1987. Cultures in PDA were white to creamy white and cottony with diffuse margins. Colonies covered the 90-mm-diameter petri dish surface in 5 days. Conidia were 20 to 23 × 1 to 1.5 μm, unicellular, hyaline, and filiform. PCR amplifications of the DNA extracts of C. ampelina with Camp-1 and Camp-2R primers gave a characteristic DNA fragment of 300 bp (3) and DNA sequences of the ITS4-ITS5 amplicons (GenBank Accession No. EU597296) confirmed the identification. For the first time, the 5' end of the β-tubulin gene was sequenced and deposited in GenBank (Accession No. EU600926). Pathogenicity tests were conducted as described above for L. theobromae. Both pathogens were examined in the same experiment. C. ampelina was reisolated from internal brown streaking lesions in 25% of the rootstocks and 33% of the canes. Control plants exhibited no symptoms. L. theobromae appeared to be a more aggressive pathogen than C. ampelina on grapevine with more internal brown streaking and greater recovery of pathogen from inoculated samples. To our knowledge, this is the first report of L. theobromae and C. ampelina causing grapevine decline in Castilla y León. References: (1) J. Luque et al. Phytopathol. Mediterr. 45:S101, 2006. (2) M. T. Martin and R. Cobos. Phytopathol. Mediterr. 46:18, 2007. (3) D. Pavlic et al. Stud. Mycol. 50:313, 2004.

Distinguishing noise from chaos

Chaotic systems share with stochastic processes several properties that make them almost undistinguishable. In this communication we introduce a representation space, to be called the complexity-entropy causality plane. Its horizontal and vertical axis are suitable functionals of the pertinent probability distribution, namely, the entropy of the system and an appropriate statistical complexity measure, respectively. These two functionals are evaluated using the Bandt-Pompe recipe to assign a probability distribution function to the time series generated by the system. Several well-known model-generated time series, usually regarded as being of either stochastic or chaotic nature, are analyzed so as to illustrate the approach. The main achievement of this communication is the possibility of clearly distinguishing between them in our representation space, something that is rather difficult otherwise.

Characterization of the mechanism of action of a catalytic antibody

The time course of phenylacetate hydrolysis by the catalytic antibody 20G9 has a kinetic burst lasting several reaction cycles. The burst is caused by partial mixed inhibition by one product of the hydrolysis, phenol, which binds with an apparent dissociation constant of 4.6 microM. Phenol binding causes kcat to decrease from 9.1 min-1 to 1.0 min-1 and Km to decrease from 300 microM to 36 microM. Because Km decreases but kcat/Km is unaffected, phenol must perturb the ground state structure but not the transition state structure. Structural complementarity to the transition state seems to be an important contributor to catalysis by 20G9 because weak binding in the ground state can be markedly improved by adding phenol, but tight binding of the transition state, which has been optimized by the immune system, cannot be readily improved. Further evidence that the substrate ground and transition states differ greatly in complementarity to the antibody is that the substrate binds more than five orders of magnitude more weakly than the transition state analogue hapten to which the antibody was raised. Two additional phenol molecules bind at higher product concentrations; the first binds over the concentration range of 15 to 86 microM and accelerates hydrolytic activity by 42%; the second is a competitive inhibitor with a Ki of 140 microM. Binding of multiple phenol molecules suggests the presence of abundant hydrophobic amino acids in the complementarity-determining region of 20G9.

Behavior and preservation of an in vitro collection of European aspen in Spain

An in vitro collection has been established with selected European aspen from Palencia province (Spain). Currently, this collection includes 32 high quality clones, selected for their good bearing and healthy state. Most of them belong to different discrete local populations. Populus tremula L. was propagated in proliferation Aspen Culture Medium; they required subculture every 3 months. The purpose of this study was, therefore, to select a medium which allows the maintenance of 32 clones for a period longer than 3 months without subculture and to observe the behavior of those clones in 15 different culture medium compositions. Seven nodal cutting stem explants from each clone were cultured in parallel in the different media. One and three months after setting on the stem explants, the number and the size of shoots, the root size, the presence or absence of callus and the survival, were evaluated. The survival was monthly recorded during 8 months. Taking into account the explant development, four media were proposed for collection preservation. One of them, Ga, with a reduction of salts, sucrose, 6-benzoaminopurine, omitting adenine sulphate and 1-naphthalene acetic acid, is the most economical. Behavior observations of the 32 clones in the 15 medium compositions showed the influence of the genotype of the clones.

EEG analysis using wavelet-based information tools

Wavelet-based informational tools for quantitative electroencephalogram (EEG) record analysis are reviewed. Relative wavelet energies, wavelet entropies and wavelet statistical complexities are used in the characterization of scalp EEG records corresponding to secondary generalized tonic-clonic epileptic seizures. In particular, we show that the epileptic recruitment rhythm observed during seizure development is well described in terms of the relative wavelet energies. In addition, during the concomitant time-period the entropy diminishes while complexity grows. This is construed as evidence supporting the conjecture that an epileptic focus, for this kind of seizures, triggers a self-organized brain state characterized by both order and maximal complexity.

Phenanthridine alkaloids from Zanthoxylum madagascariense

Four benzo[c]phenanthridine alkaloids have been isolated from the stem bark of Zanthoxylum madagascariense. These compounds were identified by extensive use of NMR spectroscopy.

Otilonium bromide inhibits muscle contractions via L-type calcium channels in the rat colon

The aim of this study is to evaluate in vitro the effect of otilonium bromide (OB) on the mechanical and electrical activities of the rat colonic smooth muscle using muscle bath, microelectrodes and patch-clamp techniques. Otilonium bromide dose dependently inhibited the spontaneous activity (logIC(50) +/- SE: -5.31 +/- 0.05). This effect was not modified by TTX (10(-6) mol L(-1)). Cyclic depolarizations were abolished by OB (10(-4) mol L(-1)). Electrical field stimulation induced inhibitory junction potentials (IJPs) followed by a depolarization with superimposed spikes causing a contraction. In the presence of OB (10(-4) mol L(-1)) IJPs were recorded, but spikes and contractions were abolished. Otilonium bromide (3 x 10(-6) mol L(-1)) inhibited inward current obtained in isolated cells (amphotericin perforated patch technique). The otilonium-sensitive current amplitude was maximal (75pA) around 0 mV. The effect of different doses of OB was tested by depolarizing cells from -70 mV to 0 mV. OB dose dependently inhibited the inward current with an EC(50) of 885 nmol L(-1). Abolishment of the otilonium-sensitive current by 3 x 10(-6) mol L(-1) nifedipine confirmed that it was an L-type Ca(2+) current. Our results show that OB inhibits the spontaneous and triggered muscular contractions. This effect is produced by the inhibition of muscular action potentials carried by L-type calcium current, confirming the spasmolytic properties of OB.

Promoter sequences involved in transforming growth factor beta1 gene induction in HaCaT keratinocytes after gamma irradiation

Transforming growth factor beta 1 (TGFB1) is a cytokine involved in the development of both acute and late cutaneous radiation syndromes. We previously demonstrated that ionizing radiation induces TGFB1 expression in vivo in pig skin within a few hours. The purpose of the present study was to develop an in vitro human model to identify the mechanisms of this early activation. Accordingly, human HaCaT keratinocytes were irradiated with a single dose of 20 Gy. First, radiation-induced TGFB1 overexpression was checked at both the transcriptional and transductional levels in HaCaT cells. Then electrophoretic mobility shift assays (EMSA) and transient transfection with various TGFB1 promoter constructs were used to identify the sequences involved in regulating this promoter. EMSA analysis showed the induction of nuclear protein binding activity by gamma irradiation to the -365 AP1 sequence (TGTCTCA), suggesting the involvement of AP1 sequences in the regulation of TGFB1 transcription. In gene reporter assays, maximal TGFB1 promoter activation was found for the longest construct, which contains two AP1 sequences. However, assays with constructs including deletions showed that these two AP1 sequences were not sufficient to confer TGFB1 inducibility. These results showed for the first time, to our knowledge, that transcriptional regulation is involved in radiation-induced activation of TGFB1 gene expression.

Sesquiterpenes and alkaloids from Scorodocarpus borneensis

A new sesquiterpene, scodopin, and a mixture of three tryptamine-type alkaloids, scorodocarpines A-C, were isolated from the fruits of Scorodocarpus borneensis, together with a known hemisynthetic sesquiterpene, cadalene-beta-carboxylic acid, which was isolated from the bark. The structures of the new compounds were elucidated by interpretation of spectral data, especially tandem mass spectrometry for the alkaloid mixture.

Selective oxidation of a keramaphidin B model

A crucial step in the Baldwin and Whitehead proposal for explaining the biogenesis of the marine alkaloid manzamine A is the selective oxidation of natural keramaphidin B to an iminium salt 3, which is then hydrolyzed to give the aldehyde 4. Conditions are now presented in which this selective oxidation can be performed on model compound 8, leading to the iminium salt 16. Although this salt can be considered as a model equivalent of the proposed aldehyde intermediate 4, it was found to be very resistant to hydrolysis as was the corresponding amide 20. From a synthetic point of view, the reported results illustrate the usefulness of the temporary protection of tertiary amines as aminoborane derivatives and constitute a good method for the oxidation of a sterically hindered tertiary nitrogen atom in the presence of a second nitrogen.

Alteration of transforming growth factor-beta1 response involves down-regulation of Smad3 signaling in myofibroblasts from skin fibrosis

Fibrosis is an unregulated tissue repair process whose predominant characteristics are the proliferation of myofibroblasts and an excessive deposition of extracellular matrix. Transforming growth factor (TGF)-beta1 is considered as one of the most fibrogenic cytokines. However, the molecular mechanisms involved in its profibrotic role are not fully understood. Here, we addressed the role of TGF-beta1 on cell proliferation and intracellular signal transduction in a pig model of skin fibrosis induced by gamma-irradiation. Primary myofibroblasts were isolated from the fibrotic tissue and their response to TGF-beta1 was compared to that of normal skin fibroblasts. The present results show that the differentiation of myofibroblasts involves a lack of TGF-beta1 growth inhibition and an impaired TGF-beta1 signaling. Receptor activity and Smad2/4 or Smad3/4 complex formation were similar in both cell types after TGF-beta1 treatment. However, the translocation of Smad3 protein into the nucleus was reduced in myofibroblasts as compared to that in fibroblasts, as well as its binding to target DNA sequences and the activation of the Smad binding elements found in the PAI-1. Interestingly, Smad2 was translocated similarly to the nucleus in both cell types suggesting that this protein may function normally in myofibroblasts. We propose that uncoupling of antiproliferative and profibrotic actions of TGF-beta1 in fibrosis may occur through differential regulation of the activities of Smad2 and Smad3 transcription factors.

Efficacy of teicoplanin-gentamicin given once a day on the basis of pharmacokinetics in humans for treatment of enterococcal experimental endocarditis

With the aim of investigating home therapy for enterococcal endocarditis, we compared the efficacy of teicoplanin combined with gentamicin given once a day or in three daily doses (t.i.d.) with the standard treatment, ampicillin plus gentamicin administered t.i.d., for treating experimental enterococcal endocarditis. The antibiotics were administered by using "human-like pharmacokinetics" (H-L), i.e, pharmacokinetics like those in humans, that simulated the profiles of these drugs in human serum. Animals with catheter-induced endocarditis were infected intravenously with 10(8) CFU of Enterococcus faecalis EF91 (MICs and MBCs of ampicillin, gentamicin, and teicoplanin, 0.5 and 32, 16 and 32, and 0.5 and 1 microg/ml, respectively) and were treated for 3 days with ampicillin H-L at 2 g every 4 h plus gentamicin H-L at 1 mg/kg every 8 h, or teicoplanin H-L at 10 mg/kg every 24 h, alone or combined with gentamicin, administered at dose of H-L at 1 mg/kg every 8 h or H-L at 4.5 mg/kg every 24 h. The results of therapy for experimental endocarditis due to EF91 showed that teicoplanin alone was as effective as ampicillin alone in reducing the bacterial load (P > 0.05). The combination of ampicillin or teicoplanin with gentamicin was more effective than the administration of both drugs alone in reducing the log(10)CFU/gram of aortic vegetation (P < 0.01 and P < 0.05, respectively). Teicoplanin plus gentamicin H-L at 4.5 mg/kg, both administered every 24 h, showed an efficacy equal to the "gold standard," ampicillin plus gentamicin H-L at 1 mg/kg t.i.d. (P > 0.05). Increasing the interval of administration of gentamicin to a single daily dose combined with teicoplanin resulted in a reduction of bacteria in the vegetations equivalent to that achieved with the recommended regimen of ampicillin plus thrice-daily gentamicin in the treatment of experimental endocarditis due to E. faecalis. Teicoplanin plus gentamicin, both administered once a day, may be useful home therapy for selected cases of enterococcal endocarditis.

Chlorin-type photosensitizers photochemically derived from vinyl porphyrins

The reaction of singlet oxygen with four vinyl-substituted dicarboxylic porphyrins, vinyldeuteroporphyrin (VD), ethylvinyldeuteroporphyrin (EVD), hydroxyethylvinyldeuteroporphyrin (HVD) and protoporphyrin (PP) in organic solutions is investigated. The main products, the "hydroxyaldehyde" chlorin-type derivatives, are formed with a concentration-dependent photochemical quantum yield that reaches a maximum of 7.4 +/- 1.6 x 10(-3). However, owing to the high turnover of singlet-oxygen production, these chlorin-type compounds are easily prepared photochemically with a chemical yield of 70% and little side product formation. In chemical ionization mass spectrometry, these compounds display an unusual fragmentation with a loss of 16 mass units. This is attributed to the loss of the oxygen bound to the saturated carbon of the modified pyrrole unit. All these compounds sensitize the formation of singlet oxygen with a yield around 0.8. They interact with singlet oxygen with rate constants of 5 x 10(6)-9 x 10(6) M-1 s-1, lower than those measured for vinyl porphyrins. These data are likely to help in the characterization of photoproducts of vinyl porphyrins relevant to photodynamic therapy (PP, HVD). As exemplified with VD and EVD, they also point out the reaction of singlet oxygen as an efficient route to chlorin-type photosensitizers.

Lack of antimicrobial activity of sodium heparin for treating experimental catheter-related infection due to Staphylococcus aureus using the antibiotic-lock technique

OBJECTIVE

To elucidate the potential antimicrobial activity of sodium heparin in the treatment of catheter-infection using the antibiotic-lock technique.

METHODS

We performed in vitro studies of the antibiotic susceptibility, stability and synergy of sodium heparin, vancomycin and ciprofloxacin. Efficacy studies were performed in a new animal model of Staphylococcus aureus catheter-related infection in which infection was produced via the endoluminal route. White New Zealand rabbits were surgically implanted with a sylastic catheter into the inferior cava vein. Immediately afterwards, infection was induced by filling and locking the catheters with 0.7 mL of broth culture containing 108 colony-forming units of S. aureus. Eighteen hours later the antibiotic-lock technique was started. Treatment groups were: control without treatment, sodium heparin at 2500 IU/mL, vancomycin at 2500 mg/L, ciprofloxacin at 1000 mg/L, vancomycin plus heparin and ciprofloxacin plus heparin.

RESULTS

Sodium heparin showed an MIC90 higher than 6000 UI/mL against S. aureus causing catheter infection. Studies of antimicrobial synergy by the time-kill method between vancomycin and ciprofloxacin at MIC with sodium heparin at 2500 IU/mL showed no interactions. Vancomycin (2000 microg/mL) and ciprofloxacin (1000 microg/mL) in a solution containing sodium heparin (2500 IU/mL) were stable at 37 degrees C for a 72-h period. Two sets of in vivo experiments were carried out using differents strains of S. aureus. In both cases, sodium heparin showed no therapeutic efficacy when compared to control group and did not increase the antibiotic efficacy when used in combination with vancomycin or ciprofloxacin.

CONCLUSION

Sodium heparin lacked antibacterial activity against S. aureus causing catheter-related infections.

A new diterpene from Hypoestes serpens

From a defatted chloroform extract of the aerial parts of Hypoestes serpens a new diterpene exhibiting relaxant activity on isolated rat aorta was obtained. The structure of this compound, named serpendione (1), was fully established by the interpretation of its spectral data.

Lignification in transgenic poplars with extremely reduced caffeic acid O-methyltransferase activity

Transgenic poplars (Populus tremula x Populus alba) were obtained by introduction of a sense homologous transgene encoding caffeic acid O-methyltransferase (COMT) under the control either of the cauliflower mosaic virus double 35S promoter or of the eucalyptus cinnamyl alcohol dehydrogenase promoter. Although these constructs conferred a moderate overexpression of COMT in some lines, a transgenic line with the double 35S promoter was found where COMT activity in woody tissues was close to zero due to a gene-silencing phenomenon. For the first time in COMT down-regulated trees, this alteration substantially reduced lignin level in 6-month-old trees (17% decrease). Lignin structure was found to be strongly altered, with a two times higher content in condensed bonds, an almost complete lack of syringyl units, and the incorporation of 5-hydroxyguaiacyl units to the most remarkable extent reported so far. Consistent with the higher cellulose content and with the higher condensation degree of the lignin, the impact of the transformation on the kraft-pulping performances of the poplar trees positively affected the pulp yield (10% relative increase), but made lignins less amenable to industrial degradations.

Spectral characterisation and antiplasmodial activity of bisbenzylisoquinolines from Isolona ghesquiereina

From stem barks of Isolona guesquiereina three known bisbenzylisoquinolines were isolated and identified as (-)-curine, chondrofoline and isochondodendrine. Structures were established mainly on the basis of comparison of their physical and spectral data with published data for them and their methylated derivatives. Cleavage with sodium in liquid ammonia was necessary to unambiguously determine the stereochemistry of (-)-curine and subsequently establish its stereochemical link with chondrofoline, erroneously assigned as 7-O-methyl-(+)-curine. Complete and unambiguous 1H-, 15N- and 13C-NMR assignments of the three alkaloids were made by means of 2D-NMR techniques namely, COSY, HMQC, gs-HMQC, HMBC and NOESY. (-)-Curine, isochondrodendrine and their methylated derivatives were shown to exhibit strong in vitro antiplasmodial activity and in vivo activity was also observed for (-)-curine.

Petersaponins III and IV, triterpenoid saponins from Petersianthus macrocarpus

Two new triterpenoid saponins, petersaponins III and IV (1 and 2), were isolated from an n-butanol extract of the bark of Petersianthus macrocarpus. They possess 21-O-benzoyl-22-O-acetylbarringtogenol C and 21-O-2-furoxyl-22-O-tigloylbarringtogenol C as the aglycon, respectively. For both 1 and 2, the trisaccharide moiety linked to C-3 of the aglycon consists of D-glucuronic acid, D-xylose, and D-galactose, while a L-rhamnose unit is linked to C-28. The structures of 1 and 2 were elucidated by extensive NMR experiments including (1)H-(1)H (COSY, HOHAHA, NOESY) and (1)H-(13)C (HMQC and HMBC) spectroscopy and by chemical evidence.

An efficient, scalable synthesis of the HIV reverse transcriptase inhibitor Ziagen (1592U89)

Ziagen, (1S,cis)-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]- 2-cyclopentene-1-methanol, was synthesized from (1S,4R)-azabicyclo[2.2.1]hept-5-en-3-one by efficient processes which bypass problematic steps in earlier routes. 2-Amino-4,6-dichloro-5-formamidopyrimidine is a key intermediate which makes possible an efficient construction of the purine from a chiral cyclopentenyl precursor.

Improving allergy alerting in a computerized physician order entry system

Computerized physician order entry has been shown to reduce the frequency of serious medication errors. Decision support tools such as alerting functions for patient medication allergy are a key part of these applications. However, optimal performance requires iterative refinement. As systems become increasingly complex, mechanisms to monitor their performance become increasingly critical. We analyzed trend data obtained over a five-year period that showed decreasing compliance to allergy alert functions within computerized order entry. Many medication-allergy pairs were being consistently overridden. Renewal policies affecting reordering narcotics also contributed heavily to this trend. Each factor revealed a system-wide trend that could result in suggestions for policy or software change. Monitoring trends such as these is very important to maintain software correctness and ensure user trust in alerting systems, so users remain responsive to computerized alerts.

Synthesis of ultra-short-acting neuromuscular blocker GW 0430: a remarkably stereo- and regioselective synthesis of mixed tetrahydroisoquinolinium chlorofumarates

[formula: see text] The stereo- and regioselective synthesis of ultra-short-acting nondepolarizing neuromuscular blocker GW 0430 (5a) is described. Key steps involved the enantioselective transfer hydrogenation of imine 8 employing Noyori's catalyst, the stereoselective crystallization and methanolysis of trans-bataines 11 and 12, and the stereo- and regioselective trans elimination of hydrogen chloride from 14. The latter transformation allowed complete control of the position of the chloro substituent and stereochemistry at the double bond of the linker in 15.

Rubiginoside, a farnesyl glycoside from Lepisanthes rubiginosa

Chemical investigation of the methanolic fraction of Lepisanthes rubiginosa bark has led to the isolation and characterisation of a new tetrasaccharide derivative of farnesol named rubiginoside along with known triterpenoid saponins.

Pyrrolidinoindoline alkaloids from Psychotria oleoides and Psychotria lyciiflora

The chemical study of two Rubiaceae from New Caledonia, Psychotria lyciiflora and Psychotria oleoides, led to the isolation of several pyrrolidinoindoline alkaloids. Two dimers, the known meso-chimonanthine (9) and the new Nb-desmethyl-meso-chimonanthine (5), and a known trimer, hodgkinsine (1), have been isolated from P. lyciiflora. Hodgkinsine (1), quadrigemine C (2), isopsychotridine B (3), psychotridine (4), and three new alkaloids, quadrigemine I (6), oleoidine (7), and caledonine (8), have been isolated from P. oleoides. Structural assignments of the compounds were based on mass spectra analysis and 2D NMR experiments. A tentative stereochemical determination is made from 2D NMR experiments, circular dichroism study and chemical correlations. Some of these compounds are functional antagonists of somatostatine (SRIH).

Cytotoxic 3,4-secoapotirucallanes from Aaglaia argentea bark

Nine 3,4-secoapotirucallanes, argentinic acids A-I, were isolated from the bark of Aglaia argentea and transformed to their methyl esters 1-9. The structures were determined by spectral and chemical means. Compounds 1-8 showed moderate cytotoxic activity against KB cells (IC50 1.0-3.5 microg/mL).

Calodenin C: a new guibourtinidol-(4alpha-->8)-afzelechin from Ochna calodendron

A new dimeric proanthocyanidin, calodenin C [guibourtinidol-(4alpha-->8)-afzelechin], was isolated from the stem bark of Ochna calodendron and its structure determined on the basis of chemical studies and spectroscopic data, including HMBC and ROESY experiments.

Pyrrolizidine alkaloids from amphorogyne spicata

Four pyrrolizidine alkaloids, amphorogynines A-D (1-4), which belong to a new type having substituents at C-1 and C-6, were isolated from Amphorogyne spicata (Santalaceae). Their structures were elucidated by spectroscopic methods. The absolute stereochemistry (7aR) of the two main alkaloids, amphorogynines A and D, was determined using chemical correlations.

Melatonin and the gastrointestinal tract

Melatonin has been detected in the digestive tract of several species and appears to be synthesized by the enterochromaffin cells of the gut. Although a diurnal rhythm of melatonin release has been observed in gastrointestinal tissues of birds, in other species it seems to depend on the presence of nutritional elements. Melatonin binding sites have been identified in the digestive tract of several species and it has been suggested that melatonin could act as a protecting agent of the gastrointestinal mucosa. Moreover, the potential role of melatonin as a local regulator of gastrointestinal motility has been investigated. It seems that at least some effects of melatonin on gut activity depend on an antagonistic relationship between serotonin and melatonin. The effects of melatonin on segmental gut transit both in the fasting and in the fed state, as well as on the electromyographic pattern of the small intestine in rats, are described.

Fontaineine, a new alkaloid from fontainea pancheri

A new guanidine-type alkaloid, fontaineine (1), was isolated from the leaves of Fontainea pancheri and its structure elucidated by 2D NMR.

A new benzoylglucoside and a new prenylated isoflavone from lophira lanceolata

A new benzoylglucoside, lanceoloside A (1), and a new prenylated isoflavone, lanceolone (2), have been isolated from the air-dried leaves of Lophira lanceolata. Both structures were established from spectroscopic and chemical evidence.

Stress responses of horses during a long period of transport in a commercial truck

OBJECTIVES

To characterize progressive patterns of dehydration, stress responses, and water consumption in horses transported long distances in hot weather and to evaluate various measurements in detecting dehydration and stress in transported horses.

DESIGN

Prospective study.

ANIMALS

30 mature, healthy horses.

PROCEDURE

The following 4 treatment groups were studied: horses that were penned and offered water every 5 hours (n = 5), horses that were penned and not offered water (5), horses that were transported in a truck and offered water every 5 hours (10), and horses that were transported and not offered water (10). The study commenced after 6 hours of water deprivation. Every 4 hours, the truck returned to the pen area and body weights were measured, physical examinations were performed, and blood samples were obtained. During this 1-hour period, water was offered to some horses, depending on treatment group.

RESULTS

After 24 hours of transport, 3 horses were judged unable to continue and the study was terminated. Horses that were penned and offered water drank a mean of 38.2 L and horses that were transported and offered water drank 20.9 L, but some of the latter horses did not drink until after 19 or 24 hours of transport. In horses that were transported or penned and not offered water, serum electrolyte concentrations were greater than reference range values by 19 hours. Most horses that were transported and offered water consumed adequate water to postpone severe dehydration beyond 24 hours.

CLINICAL IMPLICATIONS

Tame horses in good condition and initially deprived of access of water for approximately 6 hours can be transported in groups in open trailers during hot, humid conditions for up to 24 hours before dehydration and fatigue become severe. Rectal temperature and appearance of the horses were the most useful measures for determining crisis situations.