Redefining piscine lactococcosis

Piscine lactococcosis is a significant threat to cultured and wild fish populations worldwide. The disease typically presents as a per-acute to acute hemorrhagic septicemia causing high morbidity and mortality, recalcitrant to antimicrobial treatment or management interventions. Historically, the disease was attributed to the gram-positive pathogen Lactococcus garvieae. However, recent work has revealed three distinct lactococcosis-causing bacteria (LCB)-L. garvieae, L. petauri, and L. formosensis-which are phenotypically and genetically similar, leading to widespread misidentification. An update on our understanding of lactococcosis and improved methods for identification are urgently needed. To this end, we used representative isolates from each of the three LCB species to compare currently available and recently developed molecular and phenotypic typing assays, including whole-genome sequencing (WGS), end-point and quantitative PCR (qPCR) assays, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), API 20 Strep and Biolog systems, fatty acid methyl ester analysis (FAME), and Sensititre antimicrobial profiling. Apart from WGS, sequencing of the gyrB gene was the only method capable of consistent and accurate identification to the species and strain level. A qPCR assay based on a putative glycosyltransferase gene was also able to distinguish L. petauri from L. garvieae/formosensis. Biochemical tests and MALDI-TOF MS showed some species-specific patterns in sugar and fatty acid metabolism or protein profiles but should be complemented by additional analyses. The LCB demonstrated overlap in host and geographic range, but there were relevant differences in host specificity, regional prevalence, and antimicrobial susceptibility impacting disease treatment and prevention.

IMPORTANCE

Lactococcosis affects a broad range of host species, including fish from cold, temperate, and warm freshwater or marine environments, as well as several terrestrial animals, including humans. As such, lactococcosis is a disease of concern for animal and ecosystem health. The disease is endemic in European and Asian aquaculture but is rapidly encroaching on ecologically and economically important fish populations across the Americas. Piscine lactococcosis is difficult to manage, with issues of vaccine escape, ineffective antimicrobial treatment, and the development of carrier fish or biofilms leading to recurrent outbreaks. Our understanding of the disease is also widely outdated. The accepted etiologic agent of lactococcosis is Lactococcus garvieae. However, historical misidentification has masked contributions from two additional species, L. petauri and L. formosensis, which are indistinguishable from L. garvieae by common diagnostic methods. This work is the first comprehensive characterization of all three agents and provides direct recommendations for species-specific diagnosis and management.

Flavobacterium covae is the predominant species of columnaris-causing bacteria impacting the Channel Catfish industry in the southeastern United States

OBJECTIVE

Columnaris disease is a leading cause of disease-related losses in the catfish industry of the southeastern United States. The term "columnaris-causing bacteria" (CCB) has been coined in reference to the four described species that cause columnaris disease: Flavobacterium columnare, F. covae, F. davisii, and F. oreochromis. Historically, F. columnare, F. covae, and F. davisii have been isolated from columnaris disease cases in the catfish industry; however, there is a lack of knowledge of which CCB species are most prevalent in farm-raised catfish. The current research objectives were to (1) sample columnaris disease cases from the U.S. catfish industry and identify the species of CCB involved and (2) determine the virulence of the four CCB species in Channel Catfish Ictalurus punctatus in controlled laboratory challenges.

METHODS

Bacterial isolates or swabs of external lesions from catfish were collected from 259 columnaris disease cases in Mississippi and Alabama during 2015-2019. The DNA extracted from the samples was analyzed using a CCB-specific multiplex polymerase chain reaction to identify the CCB present in each diagnostic case. Channel Catfish were challenged by immersion with isolates belonging to each CCB species to determine virulence at ~28°C and 20°C.

RESULT

Flavobacterium covae was identified as the predominant CCB species impacting the U.S. catfish industry, as it was present in 94.2% (n = 244) of diagnostic case submissions. Challenge experiments demonstrated that F. covae and F. oreochromis were highly virulent to Channel Catfish, with most isolates resulting in near 100% mortality. In contrast, F. columnare and F. davisii were less virulent, with most isolates resulting in less than 40% mortality.

CONCLUSION

Collectively, these results demonstrate that F. covae is the predominant CCB in the U.S. catfish industry, and research aimed at developing new control and prevention strategies should target this bacterial species. The methods described herein can be used to continue monitoring the prevalence of CCB in the catfish industry and can be easily applied to other industries to identify which Flavobacterium species have the greatest impact.

Pathology, microbiology, and genetic diversity associated with Erysipelothrix rhusiopathiae and novel Erysipelothrix spp. infections in southern sea otters (Enhydra lutris nereis)

Erysipelothrix spp., including E. rhusiopathiae, are zoonotic bacterial pathogens that can cause morbidity and mortality in mammals, fish, reptiles, birds, and humans. The southern sea otter (SSO; Enhydra lutris nereis) is a federally-listed threatened species for which infectious disease is a major cause of mortality. We estimated the frequency of detection of these opportunistic pathogens in dead SSOs, described pathology associated with Erysipelothrix infections in SSOs, characterized the genetic diversity and antimicrobial susceptibility of SSO isolates, and evaluated the virulence of two novel Erysipelothrix isolates from SSOs using an in vivo fish model. From 1998 to 2021 Erysipelothrix spp. were isolated from six of >500 necropsied SSOs. Erysipelothrix spp. were isolated in pure culture from three cases, while the other three were mixed cultures. Bacterial septicemia was a primary or contributing cause of death in five of the six cases. Other pathology observed included suppurative lymphadenopathy, fibrinosuppurative arteritis with thrombosis and infarction, bilateral uveitis and endophthalmitis, hypopyon, petechia and ecchymoses, mucosal infarction, and suppurative meningoencephalitis and ventriculitis. Short to long slender Gram-positive or Gram-variable bacterial rods were identified within lesions, alone or with other opportunistic bacteria. All six SSO isolates had the spaA genotype-four isolates clustered with spaA E. rhusiopathiae strains from various terrestrial and marine animal hosts. Two isolates did not cluster with any known Erysipelothrix spp.; whole genome sequencing revealed a novel Erysipelothrix species and a novel E. rhusiopathiae subspecies. We propose the names Erysipelothrix enhydrae sp. nov. and Erysipelothrix rhusiopathiae ohloneorum ssp. nov. respectively. The type strains are E. enhydrae UCD-4322-04 and E. rhusiopathiae ohloneorum UCD-4724-06, respectively. Experimental injection of tiger barbs (Puntigrus tetrazona) resulted in infection and mortality from the two novel Erysipelothrix spp. Antimicrobial susceptibility testing of Erysipelothrix isolates from SSOs shows similar susceptibility profiles to isolates from other terrestrial and aquatic animals. This is the first description of the pathology, microbial characteristics, and genetic diversity of Erysipelothrix isolates recovered from diseased SSOs. Methods presented here can facilitate case recognition, aid characterization of Erysipelothrix isolates, and illustrate assessment of virulence using fish models.

Kinetic and hydrogen production analysis in the sequential valorization of a Populus clone by cold alkaline extraction and pyrolysis

This work employed a two-step biorefining process, consisting of a hemicellulose-rich liquor production through ultrasound-assisted cold alkaline extraction (CAE), followed by thermochemical treatment of the resultant solid phase. The post-CAE solid phase's pyrolytic potential was assessed by application of thermogravimetric analysis (TGA) and Friedman's isoconversional method, and also from hydrogen production. The solid phases remaining after the CAE treatment were more reactive than the untreated raw material. Notably, the alkali concentration employed in the first step was the individual variable most pronounced influence on their activation energy (Ea). Thus, at a degree of conversion α = 0.50, Ea ranged from 109.7 to 254.3 kJ/mol for the solid phases, compared to 177 kJ/mol for the raw material; this value decreased with rising glucan content. At maximal degradation, the post-CAE solid phases produced up to 15.57% v/v more hydrogen than did the untreated raw material.

Suprachiasmatic nucleus and vagus nerve trigger preovulatory LH and ovulation

In brief

In the proestrus day, the neural and endocrine signals modulate ovarian function. This study shows vagus nerve plays a role in the multisynaptic pathways of communication between the suprachiasmatic nucleus and the ovaries where such neural information determines ovulation.

Abstract

The suprachiasmatic nucleus (SCN) regulates the activity of several peripheral organs through a parasympathetic-sympathetic pathway. Previously, we demonstrated that atropine (ATR) microinjection in the right SCN of rats during proestrus blocks ovulation. In the present study, we analysed whether the vagus nerve is one of the neural pathways by which the SCN regulates ovulation. For this, CIIZ-V strain cyclic rats on the day of proestrus were microinjected with a saline solution (vehicle) or ATR in the right or left SCN, which was followed by ventral laparotomy or ipsilateral vagotomy to the microinjection side. Some animal groups were sacrificed (i) on the same day of the surgery to measure oestradiol, progesterone and luteinizing hormone (LH) levels or (ii) at 24 h after surgery to evaluate ovulation. The left vagotomy in rats microinjected with ATR in the left SCN did not modify ovulation. In rats with ATR microinjection in the right SCN, the right vagotomy increased the levels of steroids and LH on the proestrus and ovulatory response. The present results suggest that the right vagus nerve plays a role in the multisynaptic pathways of communication between the SCN and the ovaries and indicate that such neural information participates in the regulation of the oestradiol and progesterone surge, which triggers the preovulatory peak of LH and determines ovulation.

The fish pathogen Flavobacterium columnare represents four distinct species: Flavobacterium columnare, Flavobacterium covae sp. nov., Flavobacterium davisii sp. nov. and Flavobacterium oreochromis sp. nov., and emended description of Flavobacterium columnare

Flavobacterium columnare is the causative agent of columnaris disease in freshwater fish and four discrete genetic groups exist within the species, suggesting that the species designation requires revision. The present study determined the taxonomic status of the four genetic groups of F. columnare using polyphasic and phylogenomic approaches and included five representative isolates from each genetic group (including type strain ATCC 23463^T; genetic group 1). 16S rRNA gene sequence analysis revealed genetic group 2 isolate AL-02-36^T, genetic group 3 isolate 90-106^T, and genetic group 4 isolate Costa Rica 04-02-TN^T shared less than <98.8 % sequence identity to F. columnare ATCC 23463^T. Phylogenetic analyses of 16S rRNA and gyrB genes using different methodologies demonstrated the four genetic groups formed well-supported and distinct clades within the genus Flavobacterium. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (GGDC) values between F. columnare ATCC 23463^T, genetic group 2 isolate AL-02-36^T, genetic group 3 isolate 90-106^T, and genetic group 4 isolate Costa Rica 04-02-TN^T were less than 90.84% and 42.7%, respectively. Biochemical and physiological characteristics were similar among the four genetic groups; however, quantitative differences in fatty acid profiles were detected and MALDI-TOF analyses demonstrated numerous distinguishing peaks unique to each genetic group. Chemotaxonomic, MALDI-TOF characterization and ANI/GGDC calculations afforded differentiation between the genetic groups, indicating each group is a discrete species. Herein, the names F. covae sp. nov. (AL-02-36^T), F. davisii sp. nov. (90-106^T), and F. oreochromis sp. nov. (Costa Rica 04-02-TN^T) are proposed to represent genetic groups 2, 3, and 4, respectively.

Biological mesh reconstruction versus primary closure for preventing perineal morbidity after extralevator abdominoperineal excision: a multicentre retrospective study

AIM

The aim of the study was to compare the incidence of perineal hernia and the perineal wound morbidity following extralevator abdominoperineal excision (ELAPE) between two groups - primary perineal closure and reconstruction with a biological mesh.

METHOD

One hundred and forty-seven consecutive patients who underwent ELAPE for primary rectal cancer between January 2007 and December 2018 in two tertiary referral centres were retrospectively identified from prospective databases. Perineal closure was carried out via primary closure or with a biological mesh (porcine dermal collagen mesh). Outcome measures were perineal hernia and perineal wound morbidity (infection, dehiscence, persistent sinus and chronic pain).

RESULTS

A total of 139 patients were included in the study. A prophylactic mesh was used in 80 (57.5%) and primary closure was practised in 59 (42.4%) patients. The median follow-up was 30 (interquartile range 46.88) months. Thirty patients (21.6%) developed perineal hernia. No significant differences were found between prophylactic mesh and primary closure (16.3% vs 23.3%, P = 0.07). The median period between surgery and hernia diagnosis was 8 months in the primary closure group and 24 months in the mesh group (P < 0.01). Perineal wound morbidity was significantly higher in the prophylactic mesh group (55% vs 33.9%, P < 0.01).

CONCLUSION

In our study, the use of a biological mesh did not reduce the rate of perineal hernia, although it did delay its appearance. Perineal closure using a biological mesh may increase perineal morbidity, both acute and chronic.

Description of Erysipelothrix piscisicarius sp. nov., an emergent fish pathogen, and assessment of virulence using a tiger barb (Puntigrus tetrazona) infection model

A recently described emergent disease of ornamental fish has been associated with an Erysipelothrix species positive for the surface protective antigen (spa) C gene. Whole genome sequencing was performed on five spaC Erysipelothrix isolates from diseased ornamental fish. In addition, these spaC Erysipelothrix isolates were compared to spaA-, spaB- and other spaC-positive Erysipelothrix species isolated from terrestrial and marine mammals, birds and fish using multi-locus sequence analysis (MLSA). The genomes of fish pathogenic spaC isolates were genetically distinct from Erysipelothrix rhusiopathiae, sharing 86.61-86.94 % average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values of 31.6-32.2 %, but 99.01-99.11 % ANI and 90.8-91.9 % dDDH values with the uncharacterized spaC-positive Erysipelothrix sp. strain 2 isolated from swine. The findings indicate the spaC-positive fish and swine isolates are conspecific and represent a previously unrecognized taxon. While phylogenies inferred from MLSA sequences confirm this conclusion, slight genetic differences between the spaC fish isolates and swine strain 2 were indicated. Bath immersion challenge trials were conducted using tiger barbs (Puntigrus tetrazona) exposed by immersion to 10⁷ c.f.u. ml^-1 of three fish pathogenic spaC Erysipelothrix species, and three spaA and two spaB E. rhusiopathiae isolates as a model of infection. Thirty days post-challenge, cumulative mean percentage survival was 37 % for the spaA, 100 % for the spaB and 13 % for the spaC isolates, revealing differences in virulence among the various spa genotypes in fish. Genetic findings and observed differences in virulence demonstrate the fish pathogenic spaC isolates represent a novel species, for which the name Erysipelothrix piscisicarius sp. nov. is proposed. The type strain is E. piscisicarius 15TAL0474^T (=NRRL B-65533^T=ATCC-TSD-175^T=DSM 110099^T).

Multiplex PCR for genotyping Flavobacterium columnare

Recent research has identified four distinct genetic groups among isolates of Flavobacterium columnare through multilocus phylogenetic analyses; however, there are no quick methods to determine the genotype of an isolate. The objective of this research was to develop a multiplex PCR to rapidly genotype F. columnare to genetic group. Comparative bacterial genomics was used to identify regions in the genomes unique to each genetic group, and primers were designed to specifically amplify different sized amplicons for each genetic group. The optimized assay was demonstrated to be specific for each genetic group and F. columnare, and no specific amplicons were generated using gDNA from a panel of other Flavobacterium spp. and bacterial fish pathogens. The analytical sensitivity of the assay ranged from 209 to 883 genome equivalents depending on the genetic group. The multiplex PCR was evaluated by genotyping a panel of 22 unknown F. columnare isolates and performing DNA sequencing of the dnaK gene in parallel. The results demonstrated 100% accordance between multiplex PCR results and assignment to genetic group via phylogenetic analysis. The multiplex PCR provides a useful tool for assigning an unknown isolate to genetic group and may be used to determine which genetic groups of F. columnare are circulating and most predominant in different aquaculture industries.

[Effectiveness of mobile technology and weight gain in pregnant women in Callao, Peru]

OBJECTIVE

To evaluate the effectiveness of mobile technology in the appropriate weight gain of pregnant women.

MATERIALS AND METHODS

A quasi-experimental study. The sample included 117 pregnant women attending health facilities at la Dirección Regional de Salud (Diresa), Callao. Messages were sent to 58 pregnant women who formed the experimental group to improve their lifestyles and assistance to prenatal care (APC), while 59 pregnant women received routine education provided for pregnants. Messages were sent every three days. The nutritional status of the pregnant women was evaluated using the pre gestational BMI at the first visit of the APC. The weight gain was obtained from the difference between pre-gestational weight and weight recorded during the last controls.

RESULTS

The adequate weight gain was 27.6% of intervened pregnancies and 25.4% in the non-intervened. The 79.3% pregnant had six or more NPC in the group intervened and 54.2% in the non-intervened. The weight gain was excessive in 5.1% in the non-intervened pregnant and 1.7% in the intervened. The highest percentage of pregnant women with adequate weight gain (32.0%) was observed in the intervened pregnancies with pre-gestacional overwhegith.

CONCLUSIONS

There was no statistic difference in the use of mobile technology for a proper weight gain between both study groups. There were greater fulfillment of APC in intervened pregnancies compared to the non-intervened (p<0.05).

Identification of Four Distinct Phylogenetic Groups in Flavobacterium columnare With Fish Host Associations

Columnaris disease, caused by the Gram-negative bacterium Flavobacterium columnare, is one of the most prevalent fish diseases worldwide. An exceptionally high level of genetic diversity among isolates of F. columnare has long been recognized, whereby six established genomovars have been described to date. However, little has been done to quantify or characterize this diversity further in a systematic fashion. The objective of this research was to perform phylogenetic analyses of 16S rRNA and housekeeping gene sequences to decipher the genetic diversity of F. columnare. Fifty isolates and/or genomes of F. columnare, originating from diverse years, geographic locations, fish hosts, and representative of the six genomovars were analyzed in this study. A multilocus phylogenetic analysis (MLPA) of the 16S rRNA and six housekeeping genes supported four distinct F. columnare genetic groups. There were associations between genomovar and genetic group, but these relationships were imperfect indicating that genomovar assignment does not accurately reflect F. columnare genetic diversity. To expand the dataset, an additional 90 16S rRNA gene sequences were retrieved from GenBank and a phylogenetic analysis of this larger dataset also supported the establishment of four genetic groups. Examination of isolate historical data indicated biological relevance to the identified genetic diversity, with some genetic groups isolated preferentially from specific fish species or families. It is proposed that F. columnare isolates be assigned to the four genetic groups defined in this study rather than genomovar in order to facilitate a standard nomenclature across the scientific community. An increased understanding of which genetic groups are most prevalent in different regions and/or aquaculture industries may allow for the development of improved targeted control and treatment measures for columnaris disease.

Comparative Phenotypic and Genotypic Analysis of Edwardsiella Isolates from Different Hosts and Geographic Origins, with Emphasis on Isolates Formerly Classified as E. tarda, and Evaluation of Diagnostic Methods

Edwardsiella spp. are responsible for significant losses in important wild and cultured fish species worldwide. Recent phylogenomic investigations have determined that bacteria historically classified as Edwardsiella tarda actually represent three genetically distinct yet phenotypically ambiguous taxa with various degrees of pathogenicity in different hosts. Previous recognition of these taxa was hampered by the lack of a distinguishing phenotypic character. Commercial test panel configurations are relatively constant over time, and as new species are defined, appropriate discriminatory tests may not be present in current test panel arrangements. While phenobiochemical tests fail to discriminate between these taxa, data presented here revealed discriminatory peaks for each Edwardsiella species using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) methodology, suggesting that MALDI-TOF can offer rapid, reliable identification in line with current systematic classifications. Furthermore, a multiplex PCR assay was validated for rapid molecular differentiation of the Edwardsiella spp. affecting fish. Moreover, the limitations of relying on partial 16S rRNA for discrimination of Edwardsiella spp. and advantages of employing alternative single-copy genes gyrB and sodB for molecular identification and classification of Edwardsiella were demonstrated. Last, sodB sequencing confirmed that isolates previously defined as typical motile fish-pathogenic E. tarda are synonymous with Edwardsiella piscicida, while atypical nonmotile fish-pathogenic E. tarda isolates are equivalent to Edwardsiella anguillarum Fish-nonpathogenic E. tarda isolates are consistent with E. tarda as it is currently defined. These analyses help deconvolute the scientific literature regarding these organisms and provide baseline information to better facilitate proper taxonomic assignment and minimize erroneous identifications of Edwardsiella isolates in clinical and research settings.

Isolation and characterization of Flavobacterium columnare strains infecting fishes inhabiting the Laurentian Great Lakes basin

Flavobacterium columnare, the aetiological agent of columnaris disease, causes significant losses in fish worldwide. In this study, the prevalence of F. columnare infection was assessed in representative Great Lakes fish species. Over 2000 wild, feral and hatchery-propagated salmonids, percids, centrarchids, esocids and cyprinids were examined for systemic F. columnare infections. Logistic regression analyses showed that the prevalence of F. columnare infection varied temporally and by the sex of the fish, whereby females had significantly higher prevalence of infection. A total of 305 isolates of F. columnare were recovered. Amplification of the near complete 16S rRNA gene from 34 representative isolates and subsequent restriction fragment length polymorphism analyses demonstrated that all belonged to F. columnare genomovar I. Phylogenetic analysis of near complete 16S rRNA gene sequences also placed the isolates in genomovar I, but revealed some intragenomovar heterogeneity. Together, these results suggest that F. columnare genomovar I is widespread in the Great Lakes Basin, where its presence may lead to mortality.

Biorefinery process for production of paper and oligomers from Leucaena leucocephala K360 with or without prior autohydrolysis

Lignocellulosic material from Leucaena leucocephala was subjected to a two-stage fractionation process to obtain a valorized effluent containing hemicellulose derivatives and a solid phase for producing cellulose pulp by conventional soda-anthraquinone delignification. This solid phase allows the production of cellulose pulp, under less rigorous conditions from NaOH-AQ process (177 °C, 21%, 120 min) than without pretreatment delignification (185 °C, 25%, 150 min) and better or similar properties in the paper sheets obtained (yield 27.6 and 34.0%, brightness 39.3 and 31.6% ISO, tensile index 7.8 and 10.5 N m/g, burst index 0.43 and 0.29 MPa m(2)/kg with and without previous autohydrolysis) have be found. Also, the first autohydrolysis stage allows up to 46.6% of the initial hemicellulose in the raw material to be extracted as xylooligomers, xylose and furfural into the liquid phase.

Optimization the soda-AQ process for cellulose pulp production and energy content of black liquor from L. leucocephala K360

A commercial variety of Leucaena leucocephala K360 was used for pulp production and papermaking employing the soda-anthraquinone process. Also, the chemical and energy contents of the resultant black liquors were determined to simultaneously optimize: pulp and paper production and energy generation. A process temperature of (185°C), an operating time of (120 min) and an active alkali concentration of (21%) provided sheets of paper with good strength (tensile index of 12.12 Nm/g, burst index of 0.38 kPa m(2)/g, tear index of 1.29 mN m(2)/g and a Kappa number of 20.5) and black liquor with a greater calorific value (14.1 MJ/kg) than that obtained with higher active alkali concentrations. However, reducing the active alkali concentration to a level in the low operation range led to less marked degradation of cellulose and allowed paper sheets with good properties to be obtained and energy to be optimally produced from the black liquor.

Exploitation of hemicellulose, cellulose and lignin from Hesperaloe funifera

This work seeks the integral use of all major components of Hesperaloe funifera, separating hemicelluose by hydrothermal treatments; cellulose by pulping processes; and exploitation of lignin of pulping liquor by pyrolysis and gasification processes. By using sulfuric acid in the hydrothermal treatment (150-190 °C, 0-20 min after reaching operating temperature, 6-10 liquid/solid ratio, 0.1-0.5% sulfuric acid), the glucose and xylose of liquid fraction increase from 1.5% to 5.9%, and 4.0% to 12.4%, respectively; the yields of solid fraction decrease from 91.6% to 79.5%, and the lignin content increase from 23% to 32%. Pulps and paper sheets obtained from solid fractions hydrothermal treatments and from raw material pulped with diethanolamine, are worse than those obtained with soda-anthraquinone (Yield 57.8%; kappa number 24.9; Viscosity 711 mL/g; Brightness 54.8%; Tensile index 73.6 Nm/g; Stretch 2.84%; Burst index 6.13 kN/g and Tear index 1.69 mNm2/g). By acidification (pH 6) of soda pulping liquor it separate lignin-rich solids, which by pyrolysis gave a gas containing 1.13% H2, 31.79% CO and 1.86% CH4 by weight. Gasification of the same sample provided a gas containing 0.18% H2, 24.50% CO and 17.75% CH4.

Integral valorization of tagasaste (Chamaecytisus proliferus) under hydrothermal and pulp processing

Tagasaste wood (Chamaecytisus proliferus L.F. ssp palmensis) was characterized, chemical and energy terms, and assessed its potential as a lignocellulosic raw material, and its integral fractionation by autohydrolysis and delignification with ethanol. The hydrothermal treatment of the raw material at 175-185 degrees C provided a liquor containing a substantially increased amount of oligomers (between 16.6% and 47.4% as percentages with respect to the content of the raw material in each polymer fraction). A cellulose pulp with autohydrolysis treatment increased yields (53-60%), reduced Kappa number (28.8-34.6) but also viscosity (755-857 mL/g), and decreased paper strength (2.97-5.22 kN m/kg). However, beating ethanol cellulose from tagasaste was found to improve its strength-related properties more markedly than in soda pulp from the same material (tensile index of 44 kN m/kg).

A genomic approach for the identification and classification of genes involved in cell wall formation and its regulation in Saccharomyces cerevisiae

Using a hierarchical approach, 620 non-essential single-gene yeast deletants generated by EUROFAN I were systematically screened for cell-wall-related phenotypes. By analyzing for altered sensitivity to the presence of Calcofluor white or SDS in the growth medium, altered sensitivity to sonication, or abnormal morphology, 145 (23%) mutants showing at least one cell wall-related phenotype were selected. These were screened further to identify genes potentially involved in either the biosynthesis, remodeling or coupling of cell wall macromolecules or genes involved in the overall regulation of cell wall construction and to eliminate those genes with a more general, pleiotropic effect. Ninety percent of the mutants selected from the primary tests showed additional cell wall-related phenotypes. When extrapolated to the entire yeast genome, these data indicate that over 1200 genes may directly or indirectly affect cell wall formation and its regulation. Twenty-one mutants with altered levels of beta1,3-glucan synthase activity and five Calcofluor white-resistant mutants with altered levels of chitin synthase activities were found, indicating that the corresponding genes affect beta1,3-glucan or chitin synthesis. By selecting for increased levels of specific cell wall components in the growth medium, we identified 13 genes that are possibly implicated in different steps of cell wall assembly. Furthermore, 14 mutants showed a constitutive activation of the cell wall integrity pathway, suggesting that they participate in the modulation of the pathway either directly acting as signaling components or by triggering the Slt2-dependent compensatory mechanism. In conclusion, our screening approach represents a comprehensive functional analysis on a genomic scale of gene products involved in various aspects of fungal cell wall formation.

Integral valorization of two legumes by autohydrolysis and organosolv delignification

Two woody legumes species (Chamaecytisus proliferus L.F. ssp. palmensis and Leucaena diversifolia) were evaluated for integrally exploitation. The raw material was subjected to autohydrolysis under variable operating conditions which provided a liquid phase rich in hemicellulose oligomers and a solid phase that was used to obtain cellulose pulp and paper sheets by using organosolv procedures. The chemical properties of both C. proliferus and L. diversifolia allow their integral exploitation by using a hydrothermal treatment prior to their organosolv pulping with ethanol. The pulp yields obtained are quite high (40.3% for L. diversifolia and 58.2% for C. proliferus), and so are the sugar concentrations in the liquors from the thermal pretreatment (viz. 16.1 and 20.0 g oligomers/l in C. proliferus and L. diversifolia, respectively, and 1.5 and 1.1g xylose/l, respectively, in the two raw materials). The strength-related properties of the paper sheets obtained are acceptable (tensile index 7.76 and 10.77 kN m/kg for C. proliferus and L. diversifolia, respectively and kappa index 31 and 12.5 for C. proliferus and L. diversifolia, respectively), but somewhat worse than those provided by other raw materials such as eucalyptus; however, they can be improved by mechanical refining of the pulp.

Human Anaplasmosis: The First Spanish Case Confirmed by PCR

We report a case of human anaplasmosis (HA) fulfilling the confirmation criteria: epidemiologic data and clinical picture compatible with HA; presence of a morulae within polymorphonuclear leukocyte; and positive PCR assay for Anaplasma phagocytophilum: This case report shows the presence of HA in Spain.

A comparative study of the effect of refining on organosolv pulp from olive trimmings and kraft pulp from eucalyptus wood

This paper examines the influence of the degree of refining of different pulps, produced from olive trimmings and eucalyptus wood, on various physical properties. Corresponding pulps were obtained by means of different cooking processes. Pulp from olive trimmings was obtained by means of an organosolv process and pulp from eucalyptus was obtained by means of a kraft process. Pulp from olive trimmings exhibited a lower specific surface area, water retention volume, breaking length, stretch and burst index, but a higher porosity, than eucalyptus pulp. On the other hand, the same degree of refining was achieved with less energy for olive pulp than for eucalyptus pulp. Mixed pulp from olive trimmings and eucalyptus provided paper sheets with acceptable physical properties but with reduced refining energy costs relative to eucalyptus pulp alone.

Squamous cell carcinoma of the oropharynx and esophagus in a Japanese bantam rooster

Squamous cell carcinoma of the oropharynx and esophagus was diagnosed in an adult Japanese bantam rooster. Grossly, a cauliflowerlike mass with irregular edges was found involving the ventrolateral surfaces of the caudal portion of the oropharynx and cervical portion of the esophagus. The large volume of the mass almost occluded the lumen of the alimentary passage. Histologically, the tumor consisted of irregular cords of pleomorphic epithelial cells that showed a disorganized pattern of growth and invaded the adjacent tissues. Keratinized epithelial cells and moderate numbers of keratin pearls were readily observed. The mitotic index was low, and, although the tumor was locally invasive, we found no evidence of vascular invasion or metastasis.

Aprotinin mediated antioxidant effect in Cardiosurgery with mechanical cardiorespiratory support (CMCS)

BACKGROUND

Aprotinin has been used in cardiosurgery as a hemostatic agent. Considering the implication of oxygen reactive species and proteases in the pathogenesis of Systemic Inflammatory Response Syndrome, we hypothesized that aprotinin may exert an antioxidant effect. This work was designed to evaluate the antioxidant capacity of aprotinin in vitro and in vivo in child patients undergoing cardiosurgery with mechanical cardiorespiratory support.

METHODS

Colorimetric techniques and chemiluminiscent emission assays. A blind controlled clinical trial was performed with a control (G-1, n=14, without aprotinin) and treated with aprotinin (G-2, n=12) groups (both assessed by medical decision) of child patients undergoing cardiosurgery with mechanical cardiorespiratory support. Blood samples were taken at: T-0 (induction of anesthesia), T-1 (10 minutes after begining of perfusion), T-2 (5 minutes after anoxic heart arrest), T-3 (ending operation) and T-4 (24 hours after operation).

RESULTS

We proved that aprotinin has no hydroxyl radical, superoxide anion nor H2O2 scavenger capacity as well as its capacity for inhibiting in vitro activated-leukocyte chemiluminiscence. Malonildialdehyde levels were higher in G-1 than G-2 with the greatest difference at T-2 (7.2+/-3.6 nmol/ml in G-1 vs 4+/-1.65 in G-2). Phospholipase A2 activity showed a tendency of higher values in G-1 than G-2 although there was no statistical significance. Uric acid concentration was greater in G-2 at T-1, T-2, T-3 and T-4 than G-1 and catalase activity was higher in G-2 at T-0, T-2 and T-3 than G-1 with noteworthy difference only at 5 minutes after anoxic heart arrest. Low cardiac output, arrhythmias and sudden death in the early postoperative phase were less frequent in the treated group.

CONCLUSIONS

These results suggest that aprotinin exerts a primary antioxidant activity and its protective effects in cardiosurgery seem to be associated with reduction of systemic oxidative stress.

Influence of fitness on the integrated neuroendocrine response to aerobic exercise until exhaustion

A group of trained and sedentary men performed an incremental graded exercise-test to exhaustion in order to assess the organic response of the two main stress-activated systems: the sympathetic nervous system with its endocrine component (the adrenal medulla), and the hypothalamic-pituitary-adrenal (HPA) axis. Maximal plasma concentrations of ACTH, cortisol and endogenous opioids (beta-endorphins) were obtained at the end of the exercise-test in the trained group. Thus ACTH increased from basal value of 21.25 +/- 2.5 pg/ml to 88.78 +/- 11.8 pg/ml at the end of the exercise (p<0.01); cortisol, from 16.56 microg/dl +/- 4.94 microg/dl to 23.80 +/- 4.57 microg/dl in min 15 of the recovery period (p<0.001); and beta-endorphin from 21.80 +/- 8.33 pmol/ml to 64.36 +/- 9.8 pmol/ml in min 3 of the recovery period (p<0.05). Catecholamine levels were increased from initial values at the end of the effort test in both control and trained groups. Control subjects exhibited a higher responsiveness compared to trained and showed superior intrinsic stimulation of the sympathetic nervous system. These results reveal a different response according to fitness in a physical stress situation.

Influence of the operating conditions in the acetone pulping of wheat straw on the properties of the resulting paper sheets

A central composite factor design was used to examine the influence of independent variables in the acetone pulping of wheat straw (processing temperature, time, and acetone concentration) on the yield of the resulting pulp, and on various physical properties of paper sheets (breaking length, stretch, burst index, tear index and brightness) obtained from it. Equations that related each dependent variable to the different independent variables were obtained, and these reproduced the experimental results for the yield, breaking, stretch, burst index and brightness obtained at temperatures, times, and acetone concentratons over the ranges 140-180 degrees C, 60-120 min and 40-80%, respectively, with errors less than 20%. Obtaining the optimum breakinig length, stretch, burst index and tear index for the paper sheets (3,456 m, 1.42%, 1.36 kN/g and 3.86 mNm2/g, respectively) entails using a high temperature; the processing time and acetone concentration only influence stretch, optimization of which requires using a short time and a low concentration. The optimum brightness (30.44%) is achieved with a low temperature, a short time and a medium acetone concentration. In order to minimize losses of solvent during its recovery and recycling while ensuring acceptable levels of the properties of the paper sheets, a high temperature, a low acetone concentration and a short time can be used; the brightness level thus obtained is only 10% lower than the optimum value.

Influence of process variables in the ethanol pulping of olive tree trimmings

A central composition design was developed to study the influence of process variables (temperature, pulping time and ethanol concentration) on the properties of the pulp produced (yield and holocellulose, alpha-cellulose and lignin contents) and the pH of the resulting wastewater, in the ethanol pulping of olive tree trimmings. The proposed equations reproduce the experimental results for the dependent variables with errors less than 5% for the holocellulose and alpha-cellulose contents, yield and wastewater pH, and less than 15% for the lignin content. Obtaining pulp with acceptably high yield (37.6%), high holocellulose and alpha-cellulose contents (above 88.8% and 46.9%, respectively), and low lignin contents (below 7.2%), entails operating at a pulping temperature of 200 degrees C, using an ethanol concentration of 75% and a pulping time of 60 min.

Autologous stem cell transplantation for clinically aggressive non-Hodgkin's lymphoma: the role of preparative regimens

We investigated the impact of the most commonly used preparative regimens on the outcome of 395 patients with diffuse large cell lymphoma (DLCL), consecutively reported to the registry of the Spanish GEL/TAMO. Among them, 139 (35%) were autografted in 1st CR, 86 (22%) in 2nd/3rd CR, 124 (31%) had chemosensitive disease and 46 (12%) had chemoresistant disease. Conditioning consisted of chemotherapy-only in 348 patients (BEAM, 164; BEAC, 145; and CBV, 39) and radiochemotherapy with CY and TBI in 47. Median times to granulocyte, platelet recovery and to discharge were significantly shorter in the chemotherapy-only group. Early transplant-related mortality was significantly higher when using CY-TBI. After a median follow-up of 28 months, overall survival (OS) at 8 years of patients conditioned with BEAM or BEAC (58% (95% CI 50-66%)) was more favorable than with CBV (40% (95% CI 24-56%)), and significantly better than with CY-TBI (31% (95% CI 18-44%)). Multivariate analysis revealed that patients conditioned with chemotherapy-only regimens had improved OS, disease-free (DFS) and relapse-free survival (RFS) when compared to those conditioned with CY-TBI. Status at transplant was also a powerful prognostic indicator. We conclude that preparative regimens consisting of chemotherapy-only seem more efficacious than CY-TBI as conditioning for DLCL, because of faster engraftment and greater anti-lymphoma effect, as indicated by improved OS, DFS and RFS.

Depletion of brain glutathione potentiates the effect of 6-hydroxydopamine in a rat model of Parkinson's disease

In order to examine the possible role of rat brain glutathione depletion by diethyl maleate (DEM) in the potentiation of 6-hydroxydopamine (6-OHDA) neurotoxicity, the relationships between both effects were evaluated using the circling behavior test (CBT), and determining striatal glutathione S-transferase (GST)-specific activity. There were significant differences between the two studied groups: 6-OHDA and DEM + 6-OHDA lesioned animals in striatal glutathione (GSH) concentration at the moment of the lesion with 6-OHDA and also at the end of the experiment (30 d after 6-OHDA lesion). The circling behavior test following the administration of amphetamine was qualitatively different between both groups of simple- and double-damaged animals. In accordance with our results, DEM injury makes the animals more susceptible to brain-oxidative damage by 6-OHDA, which can indicate that in the double-damaged animal group, DEM could induce potentiation of the toxicity through striatal glutathione depletion.

Beekeeper' arthropathy

OBJECTIVE

To describe the clinical, analytical, and radiological features of an observed arthropathy affecting beekeepers.

METHODS

Prospective study of 34 patients (32 male, 2 female), mean age 42 years (range 16 to 66 years), evaluated for the presence of acute or chronic arthritis related to beekeeping. All patients were working and living in the same village, Fuenlabrada de los Montes (1300 habitants), where there is a census of 180 beekeepers. An epidemiologic inquiry reported that > 50% of them reported episodes of arthritis on the hands during the month of August, at the time of honey collection.

RESULTS

Acute arthritis was observed in 10 patients. Pain, tenderness, joint swelling, and warmth were present in most cases. Chronic arthropathy was noted in 32 patients. Tenderness was present in 16 cases, synovial thickening in 12, limited joint mobility in 8, bony swelling in 15, and joint deformities in 13 patients. Radiological study showed periarticular soft tissue swelling, bone sclerosis, periostitis, bony erosions, subchondral cysts, geodes, osteophytes, and joint narrowing.

CONCLUSION

Beekeepers have joint disease apparently related to bee stings. Etiopathogenesis is unknown. Mechanical trauma, venom compounds, infection, and foreign body synovitis are factors that are thought to influence the pathogenesis of this syndrome. We designate the condition "beekeepers' arthropathy," and consider it an occupational disorder.

Metabolic and hormonal changes during aerobic exercise in distance runners

A group of long-distance runners is studied in order to clarify aspects concerning neuroendocrine mechanisms regulating organic adaptation to maximum effort, with special interest in the function of the growth hormone in fat metabolism and the possible use of ketone bodies as an alternative source of energy. A test is designed on a treadmill with a gradient of 3% and progressive increases in speed of 2 Km/h every 10 min, starting at 6 Km/h, and continuing until exhaustion. Masks are worn to enable the breath by breath measurement of expired gases and the subjects are monitored electrocardiographically using V5. For blood sample collection an antecubital vein is catheterized with a system enabling the replacement of the blood volume extracted by means of perfusion with physiological saline solution, and the increasing concentration of hormones in the blood is evaluated. The results obtained, indicate that epinephrine as well as GH hormones increase significatively from 20 min of exercise in runners promoting changes from carbohydrates to lipids as fuels to carry out exercise. The concomitant variations in energy substrates support the former hypothesis of work. Moreover, the muscle could employ acetylCoA originating from acetoacetate as an alternative metabolic source of fuel during maximum effort.

Modifications in the distribution of met-enkephalin in the pons of the cat, following the intravenous administration of clonidine: an immunocytochemical experimental study

The distribution of met-enkephalin in the cat and its modifications following the stimulation by intravenous clonidine, was studied with indirect immunocytochemical techniques. We observed a decrease in the immunoreactivity of met-enkephalin following the administration of clonidine, relative to the controls, in the following structures: locus coeruleus, nucleus cuneformis, formatio reticularis, nucleus gigantocellularis, nucleus reticularis lateralis, nucleus reticularis, nucleus reticularis parvocellularis, nucleus sensorius superior n. trigemini, nucleus raphes, substantia grisea periventricularis, nucleus eminentiae teretis, colliculus inferior, nucleus motorius n. trigemini, nucleus tracto spinalis n. trigemini, tractus spinalis n. trigemini and nucleus tracto mesencephalici n. trigemini. These experimental observations link the immunoreactivity changes to the structures that are associated with the direct action of clonidine and conclude that the pars metencephalinergicus of the efferent pontine pathway of pain is in morpho-functional relationship with the analgesia produced by clonidine; an analgesic of an endogenous opiate character.

[Indicators of oxidative stress and the effect of antioxidant treatment in patients with primary Parkinson disease]

INTRODUCTION AND OBJECTIVE

Parkinson's disease (PD) is characterized by a progressive, slow loss of dopaminergic neurones in the substance nigra. Although the cause of this neurone loss is unknown, at the present time many papers suggest oxidative stress (OS), secondary to dopaminergic metabolism, as an aetiopathogenic factor of PD. Therefore study of the part played by OS in this would permit the use of antioxidants (AO) as another possibility for treatment of the disease. It would also be a major step forward in the search for possible biological markers.

MATERIAL AND METHODS

A study using spectrophotometric techniques was made of the serum levels of four biochemical indicators: catalase (CAT), malonyl aldehyde (MDA), phospholipase A2 (PLA2) and Vitamin C (VITC) in controls and in patients with PD. We found the average value for each of the variables studied in controls and in patients, taking AO treatment into account.

RESULTS

The effect of clinical variables on serum levels of CAT, MDA, PLA2 and VITC was analyzed. It was seen that only the clinical state of Hoen and Yahr was related to the biochemical indicators. The CAT activity and VITC concentration showed statistically significant differences between patients (independently of their AO treatment) and controls. The CAT activity was significantly less in those treated with AO. The patients with PD did not all have the same degree of OS. The effect of AO treatment on plasma markers showed changes only in one subgroup of Parkinson patients.

CONCLUSIONS

Our study suggests that AO treatment in this condition should be tailored to the individual patient according to the degree of OS present.

Maintenance of the threshold/maximum heart rate quotient in swimmers

The anaerobic threshold (AT) was calculated in 23 swimmers by field methods: MADER (MM) and modified exponential MADER (EM) and laboratory methods: SKINNER (SM), ROBERGS (RM), CONCONI (CM), and ventilatory (VM). Two types of test were designed. The first in a swimming pool (test 1), performing four series of increasing intensity swims, and the second on a cycle ergometer increasing until exhaustion (test 2). In both tests the heart rate (HR) was recorded in beats per minute by telemetry. Despite the different HR at the AT: 180.0 +/- 2.7 (MM), 179.1 +/- 2.4 (EM), 166.0 +/- 2.9 (SM), 157.0 +/- 2.8 (RM), 167.6 +/- 2.7 (VM) and 168.8 +/- 2.2 (CM), and the different maximum HR (HRmax) in the two tests: 201.6 +/- 2.0 in Test 1 and 188.5 +/- 1.6 in Test 2; the percentage HR in the AT/HRmax proved to be similar for all the methods except RM (88.0%-89.2%). The mechanism of organic control in progressive exercise can therefore have, in this test, a "threshold" zone at a given percentage of the maximum capacity of adaptation, both when the exercise is carried out in a pool and also on a cycle ergometer.

Fixed drug eruption induced by lidocaine and patch testing

Fixed drug eruption (FDE) is a peculiar drug-induced cutaneous reaction, that characteristically reappears at the same site when the etiologic drug is readministered. We present a case of a 27-year old male who was referred to us after two episodes of erythema on the palms, soles, and genital areas with posterior desquamation after receiving local anesthetics. Skin tests with lidocaine, mepivacaine and bupivacaine were negative. Eight hours after challenge with lidocaine the lesions reoccurred. Patch tests with lidocaine on healthy skin and residual lesions were negative, but 48 hours later the lesions reappeared on the same areas as before. Challenge with mepivacaine and bupivacaine were negative.

IgE binding proteins in honey: discussion on their origin

Pollen proteins, most frequently from Compositae plants, and glandular enzymes from Hymenoptera insects are the only honey allergens involved in every case of honey sensitization reported so far. Surprisingly, we found three patients, all showing the same pattern of honey sensitization with clinical history, cutaneous test and specific IgE clearly positive to honey crude extract but not to the aforementioned components. IgE binding bands, mainly at 54, 46, 17 and 16 kDa, were recognized by the sera of the three patients on blots following electrophoretic separation of a local honey extract under dissociating conditions. Attempts to identify these proteins with the most common honey allergens by means of SDS-PAGE immunoblotting failed, leaving open the question on the origin of protein allergens in cases of honey allergy. Thus, if bee-derived components are not proven to be involved in honey sensitization, other protein sources, such as nectar, should not be disregarded.

[Seroepidemiologic study of hepatitis C virus infection in a general population from the region of La Rioja, Spain]

BACKGROUND

To assess the prevalence of hepatitis C virus (HCV) infection in a general population and to identify risk factors for acquiring infection. POBLATION AND METHODS: A cross section of the general urban population of La Rioja aged between 14 and 65, was studied by choosing a random sample (n = 890). Serum samples were screened for HCV antibodies by second-generation enzyme-linked immunosorbent assays and recombinant immunoblot assays. We investigated the relationship between HCV serostatus and age, intravenous drug use, tattoos, blood transfusion, history of hepatitis, previous surgical operations, the administration of parenteral treatment and the number of sexual partners.

RESULTS

The overall prevalence of anti-HCV antibodies was 2%. The logistic regression analysis confirmed a statistically significant association between anti-HCV positivity and intravenous drug use (OR = 169.67; CI 95%: 21.1-1,364.75), exposure to a blood transfusion (OR = 10.41; CI 95%: 3.03-35.75); tattoos (OR = 9.04; CI 95%: 1.25-65.36), and male sex (OR = 5.35; CI 95%: 1.34-21.42). However, that 38% of subjects had no risk factors for HCV infection.

CONCLUSIONS

These results show a high proportion of people were found to have anti-HCV antibodies. The possible mode of infection in one third of these subjects is not known. In the half of these cases the infection was found have been acquired by an intravenous mechanism: blood transfusion or drug use.

[Acute right ventricular insufficiency reversible following anthracycline treatment]

Anthracyclines are very effective antineoplastic agents for the treatment of acute leukemia. Early and late dose-related cardiotoxicity can occur. We present a 33 year old women who developed a reversible right heart failure fifteen days after receiving a treatment with doxorubicine. Severe regional wall motion abnormalities were appreciated through two-dimensional and Doppler-flow echocardiography, there was no evidence of impaired systolic or diastolic left ventricle function. Two weeks later, remission of acute right ventricle failure was obtained, echocardiographic assessment was normal at this time. Incidence of right ventricle abnormalities after treatment is discussed.

[Amebic liver abscess and amebic colitis in a couple]

Amebiasis is a disease commonly extended all around the world, its prevalence depending on the population under study. In Spain, most cases published are of exotic acquisition. We present the case of a married couple from Venezuela presenting two different forms of invasive amebiasis: acute colitis and hepatic abscess. In our environment, once the diagnosis of amebiasis is established, a close follow-up of the patients must be made, including the evaluation of the closest contacts. Regarding the treatment, we think that the asymptomatic forms must be treated with a luminal amebicidal and the symptomatic forms, with hystic amebicidal followed by luminal amebicidal.

Monoamine metabolites in normal human cerebrospinal fluid and in degenerative diseases of the central nervous system

Measurement of monoamine metabolites in cerebrospinal fluid (CSF) has been one of the few methods available to study monoamine transmitter function in the human central nervous system (CNS). It has steadily proved to be of much use in clinical research of neurological and psychiatric diseases, in which altered functions of central monoamine neurotransmitters have been identified. In this work 3-methoxy-4-hydroxyphenylethylglycol (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) were quantified in normal CSF and in patients with untreated Parkinson's disease (PD) and olivopontocerebellar atrophy (OPCA). Normal CSF was obtained from 162 patients at the time of spinal anesthesia for surgery. Reference values for monoamine metabolites were established for normal adult lumbar CSF. Up to the age of 70 years no relation of monoamine metabolite concentration with age or sex were encountered. In individuals above 70 years of age higher levels of MHPG, HVA, and 5-HIAA were present in women, while in men only higher levels of MHPG could be detected. A strong correlation between 5-HIAA and HVA concentrations were observed in all groups. PD patients exhibited normal CSF metabolite levels, but an altered 5-HIAA/HVA ratio, favoring 5-HIAA. Dominant and recessive OPCA differed essentially in HVA concentration-diminished in the first group and elevated in the last. Comparing the results obtained in PD and dominant OPCA, we suggest that the decrease of CSF HVA in the latter group might not reflect nigrostriatal degeneration as we previously thought. Possibly another factor influencing dopamine function in the CNS is involved.

[Function of growth hormone in the human energy continuum during physical exertion]

A study has been carried out in 18 healthy sedentary males (controls) and 15 trained handball players. It was programmed two different tests on cycle-ergometer: Test 1 aerobic of progressive increments of load (1 W/kg/3 min) and Test 2 (A) anaerobic (4 W/kg, during 1.5 min) and after resting 10 min., Test 2 (B) till exhaustion. The blood samples were 10 ml each collected by antecubital vein catheterization. Before, during and post-exercise recovery period HG hormone, glycemia, lactate, and FFA were measured. It was found a correlation between HGH levels and substances of the energetic metabolism. The only exception was trained subjects test-2 possibly due to slower response of HGH. However FFA variation levels are correlated at the beginning with the increasing levels (p less than 0.001). It is concluded that HGH can play an important role on the turn-over to get fuel to contractile process from carbohydrates to free fatty acids.

Effect of ethanol on the specific transport system for L-lysine in Saccharomyces cerevisiae

Preincubation of resting cells of Saccharomyces cerevisiae double mutant can1 gap1 (with a single transport system for L-lysine) with metabolic substrates stimulated subsequent uptake of lysine. While in the wild type the stimulation is connected primarily with carrier protein synthesis (delayed, cycloheximide-inhibitable effect) in the mutant an immediate tapping of an energy source (antimycin-inhibited) is practically solely involved.

Uptake of L-lysine by a double mutant of Saccharomyces cerevisiae

A gap1 can1 mutant of Saccharomyces cerevisiae with a single lysine transport system remaining was used to study detailed kinetics of this transport. Its half-saturation constant was 78 mumol per litre, its maximum rate of transport was 0.29 mumol L-lysine per g dry matter per minute, both parameters being lower by more than an order of magnitude in comparison with the GAP system. The pH optimum lay at very acid values of about 3, the temperature dependence without any transition point showed an activation energy of 48 kJ/mol. The transport was inhibited by common metabolic inhibitors (3'-chlorophenylhydrazonomalononitrile, antimycin, 2-deoxy-D-glucose, sodium arsenate) as well as by a membrane-active one (uranyl nitrate). The specificity of the system was extremely high, none of the natural amino acids acting as competitor to L-lysine. The maximum accumulation ratio attained (at about 5 mg dry matter per mL) was 100: 1-120: 1, in agreement with the measured protonmotive force under the assumption of 1 H+ ion being transported with 1 lysine molecule. The ratio decreased with increasing external concentration of lysine to as little as 4: 1 at 1 mmol lysine per litre. It also decreased with increasing suspension density and it was at extremely low suspension densities (0.2 mg dry matter per mL) that ratios of as much as 500: 1 were reached. Application of group-specific inhibitors showed that the active site of the carrier contains an essential histidine residue.