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Abstract Background Besides acting as definitive hosts for Echinococcus multilocularis, dogs can become infected by the larval form of this parasite and thereby develop life-threatening alveolar echinococcosis (AE). Although AE is a zoonotic disease, most therapeutic and diagnostic approaches have been developed for human patients. In dogs, AE is typically diagnosed in the advanced stage of the disease when the parasitic mass has already caused abdominal distension. At that stage, complete resection of the parasitic mass is often impossible, leaving a guarded prognosis for the affected dogs. For humans, sensitive and specific diagnostic protocols relying on serology have been validated and are now widely used. In contrast, sensitive and specific laboratory diagnostic tools that would enable early diagnosis of canine AE are still lacking. The aim of the current study was to establish a serological protocol specifically adapted to dogs. Methods We tested several native and recombinant antigens (EmVF, Em2, recEm95, recEm18) in in-house ELISA, an in-house Western blot (WB), as well as a commercially available WB developed for serodiagnosing human AE (Anti-Echinococcus EUROLINE-WB®), using a panel of known status dog sera. Results RecEm95-antigen was revealed to be the most promising antigen for use in ELISA, demonstrating 100% (95% CI: 72–100%) sensitivity and 100% (95% CI: 93–100%) specificity in our study. The in-house WB using EmVF antigen performed as well as the recEm95-ELISA. The commercial WB also correctly identified all infected dogs, coupled with a specificity of 98% (95% CI: 91–100%). Conclusion The recEm95-ELISA alone or in combination with either the in-house WB or the Anti-Echinococcus EUROLINE-WB® (IgG) with a minor modification should be considered as the best current approach for the serological diagnosis of dogs infected with the larval stage of E. multilocularis. However, larger studies with a focus on potentially cross-reacting sera should be undertaken to verify these findings.

Blown pack is a common alteration in chilled vacuum-packed meat. Clostridium spp. is commonly known as the causing agent of this meat spoilage. In this work we demonstrate that also heterofermentative Lactic Acid Bacteria (LAB) such as Leuconostoc spp. can be involved. We analyzed four samples of chilled vacuum-packed equine meat with blown-pack spoilage and we found high levels of Lc. gasicomitatum (about 7-8 Log ufc/g). This m.o. is able to produce butyric acid and ethanol. We found both this volatile compounds in our samples.

Blown pack spoilage of vacuum packed chilled beef was characterised by chemical (GCMS) analysis, microscope evaluation and microbiological analysis. Large amounts of butyric acid were found; the alteration was probably caused by psychrotrophic clostridia.

The “dry” system for the slaughter of poultry provides mechanical defeathering followed by waxing, without scalding. The microbical contamination of n. 60 poultry carcasses was evaluated in different phases of a “dry” slaughter process. Samples from the neck region after stun and from breast after defeathering and waxing were carried out by non-destructive methods, by swabbing (n. 30 carcasses) and by sponging (n. 30 carcasses). The collected samples were examined for the Total Aerobic Count, coliforms, Escherichia coli, Staphylococcus aureus and Salmonella spp. The non-destructive method by sponging showed the higher recovery capacity for each group of microrganisms, except Salmonella spp. as absent from all samples. A low level of carcasses contamination was observed in all the processing phases considered in this study, although S. aureus was observed to be on the increase after waxing.

Background: Congenital ichthyoses (CI) comprise a heterogeneous group of genetic diseases requiring lifelong treatment and having a major effect on quality of life. Conventional treatments reduce scaling and skin discomfort; however, they usually have little or no effect on erythema and pruritus. The identification of cytokine alterations in CI raised the possibility of repurposing available biologics. Several case reports in the literature report successes using different biologics., Objective: We aimed to report the effects of biologics in real life., Methods: This was a retrospective, observational, international multicenter study of patients with CI treated with at least one biologic for a minimum of 3 months. The effect of the biologics was evaluated using an Investigator Global Assessment-Change (IGA-C) scale. A comprehensive literature search was performed in parallel., Results: A total of 98 patients were included, with a mean age of 19.7 years and both sexes equally represented. Patients with Netherton syndrome (NS) or congenital ichthyosiform erythroderma (CIE) represented the majority of patients (30% and 21.4%, respectively). Most patients (84.7%) had a severe or very severe form of CI. The most frequently used biologics were inhibitors targeting interleukin-17 (IL-17), IL-12/IL-23, or the IL-4 receptor. The mean duration of treatment was 22+20.1 months. There were 45 responders (45.9%), including 18 patients (18.3%) who were good responders; all had an erythrodermic CI subset and received one of the three main biologics. In 2 NS and CIE, IL-12/IL-23 and IL-4 receptor inhibitors tended to be most effective. Review of the literature revealed a shorter mean duration of use of biologics (11.5+8.5 months) and higher percentage of responders (85.7%), suggesting reporter bias., Conclusion: This series identified subsets of CI that may respond to biologics and will aid in designing future clinical trials of biologics for CI., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Association of Dermatologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

The availability of an effective vaccine against COVID-19 virus marked a crucial moment in the fight against its pandemic spread. Although distribution of the vaccine began in December 2020, high acceptance rates and repeated administrations are needed to achieve widespread immunization, but hesitation toward the vaccine persists to this day. To identify psychological variables and other factors associated with vaccine hesitancy, we conducted a study from August 2021 to October 2022. An Internet-based survey gathered data from 137 Italian adults, exploring attitudes, sociodemographic characteristics, psychological variables, and immunization behavior. The results analysis showed that gender (69.2% of vaccine-adverse people were males), education (years of education was negatively correlated with vaccine hesitancy), and religion (not declaring oneself religious or atheist was more likely to be associated with hesitancy toward the vaccine) were the variables influencing attitudes toward the vaccine. Other psychological variables differentiated people with opposite attitudes toward the vaccine: high scores on the Conspiracy Mentality Questionnaire (CMQ) and Core Belief Inventory (CBI) were positively correlated with vaccine hesitancy, indicating that individuals with more pronounced core belief violation, due to the pandemic, tend to express higher levels of vaccine hesitancy. Finally, a linear regression analysis confirmed the role of participants' conspiracy mentality as a valid predictor for vaccine hesitancy.

Objective: This study was initiated and conducted by several laboratories, 3 of the main cosmetic ingredient suppliers and 4 brands of cosmetics in France. Its objective is to show the interest and robustness of coupling chemical and genetic analyses in the identification of plant species. In this study, the Lavandula genus was used., Methods: In this study, we used two analytical methods. Chemical analysis from UHPLC (ultra-high-performance liquid chromatography) and genetic analysis from barcoding with genetic markers., Results: Eleven lavender species were selected (botanically authenticated) and analysed. The results show that three chemical compounds (coumaric acid hexoside, ferulic acid hexoside and rosmarinic acid) and three genetic markers (RbcL, trnH-psbA and ITS) are of interest for the differentiation of species of the genus lavandula., Conclusion: The results show that the combination of complementary analytical methods is a relevant system to prove the botanical identification of lavender species. This first study, carried out on a plant of interest for cosmetics, demonstrates the need for authentication using a tool combining genetic and chemical analysis as an advance over traditional investigation methods used alone, in terms of identification and authentication reliability., (© 2021 The Authors. International Journal of Cosmetic Science published by John Wiley & Sons Ltd on behalf of Society of Cosmetic Scientists and Societe Francaise de Cosmetologie.)

Many animals exhibit remarkable metabolic and reproductive adaptations to seasonal changes in their environment. When day length shortens, Djungarian hamsters (Phodopus sungorus) reduce their body weight and inhibit their reproductive activity, whereas the opposite occurs in springtime. These physiological adaptations are considered to depend on photoperiodic changes in hypothalamic genes encoding the peptides kisspeptin (Kp) and RFamide-related peptide 3 (RFRP3) for the control of reproduction, as well as pro-opiomelanocortin and somatostatin for metabolic regulation. The present study investigates the effect of Kp and RFRP3 on long-term body weight regulation, aiming to establish whether metabolic and reproductive hypothalamic networks may interact during adaptation to seasonal physiology. We found that chronic central administration of both Kp and RFRP3 in short photoperiod-adapted male Djungarian hamsters increased body weight, although via different pathways. The effect of Kp was dependent on testicular activity because castration prevented the body weight increase and was associated with an increase in pro-opiomelanocortin and neuropeptide Y expression. On the other hand, the orexigenic effect of RFRP3 was associated with an increase in circulating insulin and leptin levels, although it had no effect on any of the hypothalamic metabolic genes investigated, and did not change circulating levels of sex steroids. Notably, neither Kp, nor RFRP3 altered female hamster metabolic parameters. Thus, using a rodent model exhibiting seasonal changes in reproduction and metabolism, the present study demonstrates that, in addition to its role in the central control of reproduction, Kp also participates in body weight control in a sex-dependent manner via an anabolic action of testosterone. Conversely, RFRP3 affects body weight control in males mostly by acting on adiposity, with no overt effect on the reproductive system in both sexes., (© 2019 British Society for Neuroendocrinology.)

In seasonal rodents, reproduction is activated by a long photoperiod. Furthermore, maintaining an inhibitory short photoperiod for over 20 weeks triggers a spontaneous reactivation of the gonadotropic axis called photorefractoriness. Photoactivation is proposed to involve melatonin, hypothalamic thyroid hormones (TH) and (Arg) (Phe)-amide peptides. The mechanisms involved in photorefractoriness are so far unknown. We analyzed the dynamic changes in long photoperiod- and photorefractory-induced activation of reproduction in both Syrian and Djungarian hamsters to validate the current model of photoactivation and to uncover the mechanisms involved in photorefractoriness. We detected a conserved early inhibition of expression of the TH catabolizing enzyme deiodinase 3 (Dio3) in tanycytes, associated with a late decrease of the TH transporter MCT8. This suggests that an early peak of hypothalamic TH may be involved in both photoinduced and photorefractory reactivation. In photoactivation, Dio3 downregulation is followed by an upregulation of Dio2, which is not observed in photorefraction. The upregulation of (Arg) (Phe)-amides occurs several weeks after the initial Dio3 inhibition. In conclusion, we uncovered a so far unreported early inhibition of Dio3. This early downregulation of Dio3 is reinforced by an upregulation of Dio2 in photoactivated hamsters. In photorefractoriness, the Dio3 downregulation might be sufficient to reactivate the gonadotropic axis.

An important concern with the anticancer drug capecitabine (Cp), an oral prodrug of 5-fluorouracil, are dose-limiting adverse effects, in particular hand-foot syndrome (HFS) and diarrhea. Here we evaluated the association of genetic variability in all enzymes of the Cp-activation pathway to 5-fluorouracil with Cp-related early-onset toxicity in 144 patients receiving Cp. We identified a haplotype encompassing five variants in the carboxylesterase 1 (CES1) gene region including an expression quantitative trait locus associated with early-onset Cp-toxicity (Haplotype A3: OR additive = 2.2, 95% CI 1.2-4.0, P adjusted = 0.012; OR recessive = 10.3, 95% CI 2.1-49.4, P adjusted = 0.0038). Furthermore, the association of two linked cytidine deaminase (CDA) promoter variants (c.1-451C>T: OR dominant = 4.3, 95% CI 1.3-14.2, P adjusted = 0.017; and c.1-92A>G: OR dominant = 4.4, 95% CI 1.3-14.5, P adjusted = 0.015) with Cp-related diarrhea was replicated. This first study identifying an association of genetic variation in CES1 with Cp-related toxicity provides further evidence for the existence of a functional noncoding CES1-variant with a possible regulatory impact., (© 2017 American Society for Clinical Pharmacology and Therapeutics.)

Background: Besides acting as definitive hosts for Echinococcus multilocularis, dogs can become infected by the larval form of this parasite and thereby develop life-threatening alveolar echinococcosis (AE). Although AE is a zoonotic disease, most therapeutic and diagnostic approaches have been developed for human patients. In dogs, AE is typically diagnosed in the advanced stage of the disease when the parasitic mass has already caused abdominal distension. At that stage, complete resection of the parasitic mass is often impossible, leaving a guarded prognosis for the affected dogs. For humans, sensitive and specific diagnostic protocols relying on serology have been validated and are now widely used. In contrast, sensitive and specific laboratory diagnostic tools that would enable early diagnosis of canine AE are still lacking. The aim of the current study was to establish a serological protocol specifically adapted to dogs., Methods: We tested several native and recombinant antigens (EmVF, Em2, recEm95, recEm18) in in-house ELISA, an in-house Western blot (WB), as well as a commercially available WB developed for serodiagnosing human AE (Anti-Echinococcus EUROLINE-WB®), using a panel of known status dog sera., Results: RecEm95-antigen was revealed to be the most promising antigen for use in ELISA, demonstrating 100% (95% CI: 72-100%) sensitivity and 100% (95% CI: 93-100%) specificity in our study. The in-house WB using EmVF antigen performed as well as the recEm95-ELISA. The commercial WB also correctly identified all infected dogs, coupled with a specificity of 98% (95% CI: 91-100%)., Conclusion: The recEm95-ELISA alone or in combination with either the in-house WB or the Anti-Echinococcus EUROLINE-WB® (IgG) with a minor modification should be considered as the best current approach for the serological diagnosis of dogs infected with the larval stage of E. multilocularis. However, larger studies with a focus on potentially cross-reacting sera should be undertaken to verify these findings.

Purpose: The role of cerebrovascular dysfunction in seizure disorders is recognized. Blood-brain barrier (BBB) damage in epilepsy has been linked to endothelial and glial pathophysiological changes. Little is known about the involvement of pericytes, a cell type that contributes to BBB function., Methods: NG2DsRed mice were used to visualize cerebrovascular pericytes. The pattern of vascular and parenchymal distributions of platelet-derived growth factor receptor beta (PDGFRβ) cells was evaluated by immunohistochemistry. Status epilepticus was induced in NG2DsRed or C57BL/6J mice by intraperitoneal kainic acid (KA). Animals were perfused intracardially using FITC-Dextran or FITC-Albumin to visualize the cerebrovasculature. Colocalization was performed between NG2DsRed, PDGFRβ and microglia IBA-1. Confocal 3D vessel reconstruction was used to visualize changes in cell morphology and position. PDGFRβ expression was also evaluated in vitro using organotypic hippocampal cultures (OHC) treated with kainic acid to induce seizure-like activity. Co-localization of PDGFRβ with the vascular marker RECA-1 and NG2 was performed. Finally, we assessed the expression of PDGFRβ in brain specimens obtained from a cohort of patients affected by drug resistant epilepsy compared to available autoptic brain., Results: In vivo, severe status epilepticus (SE) altered NG2DsRed vascular coverage. We found dishomogenous NG2DsRed perivascular ramifications after SE and compared to control. Concomitantly, PDGFRβ(+) cells re-distributed towards the cerebrovasculature after severe SE. Cerebrovascular NG2DsRed partially colocalized with PDGFRβ(+) while parenchymal PDGFRβ(+) cells did not colocalize with IBA-1(+) microglia. Using in vitro OHC we found decreased NG2 vascular staining and increased PDGFRβ(+) ramifications associated with RECA-1(+) microvessels after seizure-like activity. Cellular PDGFRβ and NG2(+) colocalization was observed in the parenchyma. Finally, analysis of human TLE brains revealed perivascular and parenchymal PDGFRβ(+) cell distributions resembling the murine in vivo and in vitro results. PDGFRβ(+) cells at the cerebrovasculature were more frequent in TLE brain tissues as compared to the autoptic control., Conclusions: The rearrangement of PDGFRβ(+) and vascular NG2DsRed cells after SE suggests a possible involvement of pericytes in the cerebrovascular modifications observed in epilepsy. The functional role of vascular-parenchymal PDGFRβ(+) cell redistribution and the relevance of a pericyte response to SE remain to be fully elucidated., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The Pycnoporus fungi are white-rot basidiomycetes listed as food- and cosmetic-grade microorganisms. Three high redox potential laccases from Pycnoporus coccineus and Pycnoporus sanguineus were tested and compared, with the commercial Suberase® as reference, for their ability to synthesise natural active oligomers from rutin (quercetin-3-rutinoside, one of the best-known naturally occurring flavonoid glycosides). The aim of this work was to develop a process with technical parameters (solvent, temperature, reaction time and raw materials) that were easy to scale up for industrial production and compatible with cosmetic and pharmaceutical formulation guidelines. The aqueous mixture of glycerol/ethanol/buffer described in this study met this requirement and allowed the solubilisation of rutin and its oxidative bioconversion into oligomers. The four flavonoid oligomer mixtures synthesised using laccases as catalysts were analysed by high performance liquid chromatography-diode array detection-negative electrospray ionisation-multistage mass spectrometry. Their chromatographic elution profiles were compared and 16 compounds were characterised and identified as dimers and trimers of rutin. The oligorutins were different in Suberase® and Pycnoporus laccase reaction mixtures. They were evaluated for their antioxidant, anti-inflammatory and anti-ageing activities on specific enzymatic targets such as cyclooxygenase (COX-2) and human matrix metalloproteinase 3 (MMP-3). Expressed in terms of IC(50), the flavonoid oligomers displayed a 2.5- to 3-fold higher superoxide scavenging activity than monomeric rutin. Pycnoporus laccase and Suberase® oligorutins led to an inhibition of COX-2 of about 35% and 70%, respectively, while monomeric rutin showed a near-negligible inhibition effect, less than about 10%. The best results on MMP-3 activity were obtained with rutin oligomers from P. sanguineus IMB W006-2 laccase and Suberase® with about 70-75% inhibition.

Plant root development is highly responsive both to changes in nitrate availability and beneficial microorganisms in the rhizosphere. We previously showed that Phyllobacterium brassicacearum STM196, a plant growth-promoting rhizobacteria strain isolated from rapeseed roots, alleviates the inhibition exerted by high nitrate supply on lateral root growth. Since soil-borne bacteria can produce IAA and since this plant hormone may be implicated in the high nitrate-dependent control of lateral root development, we investigated its role in the root development response of Arabidopsis thaliana to STM196. Inoculation with STM196 resulted in a 50% increase of lateral root growth in Arabidopsis wild-type seedlings. This effect was completely abolished in aux1 and axr1 mutants, altered in IAA transport and signaling, respectively, indicating that these pathways are required. The STM196 strain, however, appeared to be a very low IAA producer when compared with the high-IAA-producing Azospirillum brasilense sp245 strain and its low-IAA-producing ipdc mutant. Consistent with the hypothesis that STM196 does not release significant amounts of IAA to the host roots, inoculation with this strain failed to increase root IAA content. Inoculation with STM196 led to increased expression levels of several IAA biosynthesis genes in shoots, increased Trp concentration in shoots, and increased auxin-dependent GUS staining in the root apices of DR5::GUS transgenic plants. All together, our results suggest that STM196 inoculation triggers changes in IAA distribution and homeostasis independently from IAA release by the bacteria.

In 2007 the Study Group "Clinical Risk Management" of the Italian Society of Anaesthesia and Intensive Care Unit (SIAARTI) performed a multicentric study in Intensive Care Unit (ICU) to assess the feasibility and efficacy of the Safety WalkRound (SWR) as a tool for the risk assessment. As the environment and organization of ICU are more complex than anaesthesia ones, mainly due to the severity of patients, high number of involved healthcare givers and different kinds of procedures, the Study Group decided that a check list is not fit for ICU and , after a careful review of the literature, chose to test the Safety WalkRound. in four Italian General ICUs. The SWR was born in 2003 when Frankel plans a structured interview of 15 questions (about 50% open) to collect operators' opinion about rate and type of errors, near misses, communication, problems regarding the report of adverse events and suggestions to increase patient safety. Consequently SWR is a tool of risk assessment alternative to the Incident Reporting which is marked by a diffuse underreporting of operators. Although the SWR is a new tool not validated in Italian language neither published in Italy on PubMed journals , the Study Group has decided that it might be fit for the organization of Italian Healthcare System. A back translation of the validated model of Joint Commission was provided and the translated version has been lightly changed to be employed in hospitals with and without Incident Reporting . The questions have been changed or introduced on the basis of the organization vulnerabilities detected with observational techniques or Focus Group. The interview performed in Italy contains 16 questions classified into five groups: a) error, b) error prevention, c) communication, teamwork and leadership, d) error discussion and e) relationship with patients and their families. The answers collected have been analyzed to detect the vulnerabilities in the organizations and specify the improvements to implement in every ICU. A statistical analysis was performed to verify the correlation between the answers collected and the results of the other techniques of risk assessment previously used ( observations and Focus Group ) . The value of k Pearson found ( mean value 0,976) has demonstrated this correlation and the efficacy of SWR in detecting system vulnerabilities already found with the other assessment techniques. The value of a Cronbach ( mean value 0,798) has demonstrated an internal consistency reliability. The results of this study have demonstrated that the Italian translation is fit for the model by Frankel and makes available a lot of information useful to improve patient safety. The study has demonstrated the sensibility, efficacy and efficiency of this tool in detecting the vulnerabilities in every ICU of the four ones. SWR is marked by feasibility, high compliance of operators and low costs; besides increases safety culture in the staff and demonstrating.

Unlabelled: We evaluated the effects of tourniquet application on the cardiovascular system and metabolism in 10 young men undergoing knee surgery with general anesthesia. The duration of inflation was from 75 to 108 min. Heart rate, mean arterial pressure, cardiac index (CI) by pulse contour method, and systemic vascular resistance were measured before, during, and after tourniquet inflation. pH, PaO(2), PaCO(2), and lactate blood concentrations were also measured. VO(2) and VCO(2) were assessed every minute from tracheal intubation up to 15 min after tourniquet deflation and VO(2) in excess of the basal value over the 15 min after deflation (VO(2)exc) was calculated. Mean arterial pressure increased 26% (P: < 0.05) during inflation and returned to basal values after deflation. CI did not change immediately after inflation; although, thereafter, it increased 18% (P: < 0.05). Five minutes after deflation, CI further increased to a value 40% higher than the basal value. Therefore, systemic vascular resistance increased 20% suddenly after inflation (P: < 0.05) and decreased 18% after deflation (P: < 0.05). VO(2) and VCO(2) remained stable during inflation and increased (P: < 0.05) after deflation. VO(2)exc depended on duration of tourniquet inflation time (Tisch) (P: < 0.05). After deflation, PaCO(2) and lactate increased (P: < 0.05) while Tisch increased. We conclude that tourniquet application induces modifications of the cardiovascular system and metabolism, which depend on tourniquet phase and on Tisch. Whether these modifications could be relevant in patients with poor physical conditions is not known., Implications: The clinical effects of tourniquet application were evaluated in 10 young men undergoing knee surgery. Our data indicate that tourniquet application causes hemodynamic and metabolic changes which may become clinically relevant after a long period of tourniquet inflation, particularly in patients with concomitant cardiovascular diseases.

Maximal voluntary isometric torque values of the ankle plantar (Tim,PF) and dorsal flexors (Tim,DF) were assessed in eight healthy adult males at 5 degrees and 15 degrees of dorsal flexion (DF) and at 5 degrees, 15 degrees and 25 degrees of plantar flexion (PF) with the knee at right angles, before (two times), during (three times) and after (three times) 17 days of 6 degrees head-down tilt bedrest (BR). Integrated electromyograms (iEMG) were also recorded from the gastrocnemius medialis and tibialis anterior. Tim,PF and the iEMG of the gastrocnemius medialis were significantly larger (by 14% and by 27%, respectively) at the end of recovery than before BR. This was probably the consequence of training and/or habituation leading to: (1) increased activation of the plantar flexors; and (2) decreased co-activation of the antagonist muscles. Neither Tim,DF nor the tibialis anterior iEMG changed significantly. The effects of BR on muscle performance were evaluated as follows. The net torque generated by a given muscle group was assumed to be the algebraic sum of the torque generated by the agonists and by the antagonists. Thus, for the plantar flexors Tim,PF = alpha iEMGGm - beta iEMGTa, where: (1) iEMGGm and iEMGTa are the iEMGs of gastrocnemius medialis and of tibialis anterior during maximal PF; and (2) the constants alpha and beta represent the electromechanical coupling of the plantar (alpha) and dorsal (beta) flexors. Similarly for the dorsal flexors: Tim,DF = beta iEMGTa - alpha iEMGGm, where iEMGTa and iEMGGm are the iEMGs of tibialis anterior and gastrocnemius medialis during maximal DF. Torque and iEMG values were assessed for all subjects under all experimental conditions. Thus, since the biomechanical leverage of the system was constant, alpha and beta could be calculated. During BR, alpha decreased by 25% and it dropped by a further 30% during recovery. In contrast, beta remained almost unchanged. This suggests that, in spite of training and/or habituation, BR significantly impaired the maximal isometric performance of the plantar flexors, an effect that continued during the initial 10 days of recovery.

It has been proposed that cardiac control is altered in the elderly. Power spectral analysis of heart rate variability (HRV) was performed on 12 male and 11 female elderly subjects (mean age 74 years) while at rest in supine and sitting positions, and at steady states during 5 min of exercise (35-95% peak oxygen consumption, VO2peak). There were no differences in power, measured as a percentage of the total of the high frequency peak (HF, centred at about 0.25 Hz; 13% in males vs 12% in females), low frequency peak (LF, centred at 0.09 Hz; 25% in males and 22% in females), and very low frequency component (VLF, at 0.03 Hz; 66% in males and 69% in females) between body positions at rest. There was no difference in spectral power between male and female subjects. Total power decreased as a function of oxygen consumption during exercise, LF% did not change up to about 14 ml x kg(-1) x min(-1) (40% and 80% VO2peak in males and females, respectively), then decreased towards minimal values in both genders. HF% power and central frequency increased linearly with metabolic demand, reaching higher values in male subjects than in female subjects at VO2peak, while VLF% remained unchanged. Thus, the power spectra components of HRV did not reflect the changes in autonomic activity that occur at increasing exercise intensities, confirming previous findings in young subjects, and indicated similar responses in both genders.

There have been many studies on the effects of isokinetic exercise on muscle performance in training and rehabilitative programmes. On the other hand, the cardiovascular and metabolic responses elicited by this type of exercise have been poorly investigated. This study was specifically designed to describe the relationships, if any, between metabolic and cardiorespiratory responses and power output during maximal intermittent knee isokinetic exercise when a steady state is reached. A group of 18 healthy subjects (10 men and 8 women, age range 25-30 years) were requested to perform at maximal concentric isokinetic knee extensions/flexions 60 degrees. s(-1) and 180 degrees. s(-1) for 5 min, with a 5-s pause interposed between consecutive repetitions. The power output (W) was calculated; before and during the tasks heart rate (f(c)) and arterial blood pressure (AP(a)) were continuously monitored. Pulmonary ventilation (V(E)) and oxygen uptake (VO(2)) were measured at the 4th and at the 5th min of exercise and blood lactate concentration at rest and at the 3rd min of recovery. From the 4th to the 5th min only a slight decrease in W was observed, both at 60 degrees. s(-1) and 180 degrees. s(-1). The VO(2), V(E), f(c) and AP(a) showed similar values in the last 2 min of exercise, suggesting that a steady state had been reached. The VO(2) increased linearly as a function of +W, showing a significantly steeper slope at 60 degrees. s(-1) than at 180 degrees. s(-1). The f(c), in spite of a large interindividual variation, was linearly related to metabolic demand, and was not affected by angular velocity. Systolic and diastolic AP(a) were not related either to VO(2) or to angular velocity. In conclusion it would appear that the metabolic response to maximal intermittent knee isokinetic exercise resembles that of dynamic exercise. Conversely, the cardiocirculatory responses would seem to reflect a relevant role of the isometric postural component, the importance of which should be carefully evaluated in each subject.

Power spectrum analysis of heart-rate variability was made in seven men [mean age 22 (SEM 1) years] in head-out water immersion (W) and in air (A, control) at rest and during steady-state cycling to maximal intensity (maximum oxygen uptake, VO2max). At rest W resulted in a trebled increase in the total power (P < 0.05), coupled with minimal changes in the power (as a percentage of the total) of the high frequency peak (HF, centred at 0.26 Hz; 18% vs 28%) and of the low frequency peak (LF, 0.1 Hz; 24% vs 32%). A third peak at about 0.03 Hz (very low frequency, VLF) represented the remaining power both in W and A. These changes as a whole indicated that immersion caused a vagal dominance in cardiac autonomic interaction, due to the central pooling of blood and/or the pressure of water on the trunk. Exercise caused a decrease in the total power in W and A. The LF% did not change up to about 50% V02max, thereafter decreasing towards nil in both conditions. The HF% decreased in similar ways in W and A to about half at 55%-60% VO2max and then increased to reach 1.5 times the resting values at VO2max. The central frequency of HF increased linearly with oxygen uptake, showing a tendency to be higher in W than in A at medium to high intensities. The VLF% remained unchanged. The lack of differences in the LF peak between W and A during exercise would suggest that blood distribution had no effect on the readjustments in control mechanisms of arterial pressure. On the other hand, the findings of similar HF powers and the very similar values for ventilation in W and A confirmed the direct effect of the respiratory activity in heart rate modulation during exercise.