Synthesis, molecular docking, ADMET, and evaluation of the anxiolytic effect in adult zebrafish of synthetic chalcone (E)-3-(4-(dimethylamino)phenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one: An in vivo and in silico approach

BACKGROUND

Anxiety disorders represent the complex interaction between biological, psychological, temperamental, and environmental factors; drugs available to treat anxiety such as benzodiazepines (BZDs) are associated with several unwanted side effects. Although there are useful treatments, there is still a need for more effective anxiolytics with better safety profiles than BZDs. Chalcones or 1,3-diphenyl-2-proper-1-ones can be an alternative since this class of compounds has shown therapeutic potential mainly due to interactions with GABAA receptors and serotonergic system.

OBJECTIVES

This study evaluated the anxiolytic potential of chalcone (E)-3-(4-(dimethylamino)phenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one (C2OHPDA) in adult zebrafish (Danio rerio) (ZFa).

METHODS

Each animal (n = 6/group) was treated intraperitoneally (i.p.; 20 μL) with the chalcone (4, 20, and 40 mg/kg) and with the vehicle (DMSO 3%; 20 μL), being submitted to the tests of locomotor activity and 96-h acute toxicity. The light/dark test was also performed, and the serotonergic mechanism (5-HT) was evaluated through the antagonists of the 5-HTR1 , 5-HTR2A/2C , and 5-HTR3A/3B receptors. It was investigated the prediction of the chalcone's position and preferential orientation concerning its receptor, as well as the pharmacokinetic parameters (ADMET) involved in the process after administration.

RESULTS

As a result, C2OHPDA was not toxic and reduced the locomotor activity of ZFa. Furthermore, chalcone demonstrated an anxiolytic effect on the central nervous system (CNS), mediated by the serotonergic system, with action on 5-HT2A and 5-HTR3A/3B receptors. The interaction of C2OHPDA with 5-HT2A R and 5-HT3A receptors was confirmed by molecular docking study, the affinity energy observed was -8.7 and -9.1 kcal/mol, respectively.

CONCLUSION

Thus, this study adds new evidence and highlights that chalcone can potentially be used to develop compounds with anxiolytic properties.

Naphthoquinones biflorin and bis-biflorin (Capraria biflora) as possible inhibitors of the fungus Candida auris polymerase: molecular docking, molecular dynamics, MM/GBSA calculations and in silico drug-likeness study

A new worldwide concern has emerged with the recent emergence of infections caused by Candida auris. This reflects its comparative ease of transmission, substantial mortality, and the increasing level of resistance seen in the three major classes of antifungal drugs. Efforts to create a better design for structure-based drugs that described numerous modifications and the search for secondary metabolic structures derived from plant species are likely to reduce the virulence of several fungal pathogens. In this context, the present work aimed to evaluate in silico two naphthoquinones isolated from the roots of Capraria biflora, biflorin, and its dimmer, bis-biflorin, as potential inhibitors of Candida auris polymerase. Based on the simulation performed with the two naphthoquinones, biflorin and bis-biflorin, it can be stated that bis-biflorin showed the best interactions with Candida auris polymerase. Still, biflorin also demonstrated favorable coupling energy. Predictive pharmacokinetic assays suggest that biflorin has high oral bioavailability and more excellent metabolic stability compared to the bis-biflorin analogue. constituting a promising pharmacological tool.Communicated by Ramaswamy H. Sarma.

Synthesis of aminochalcones and in silico evaluation of their antiparasitic potential against Leishmania

Leishmaniasis disease is a serious public health problem. This disease reaches about 10 to 12 million people, and 20-30 thousand people die yearly. The disease treatment is realized through pentavalent antimonial and glucantime. However, some studies indicated that these drugs presented high toxicity and cost. Therefore, it is urgent the search for new drugs that may combat this disease and are less toxic. This work analyzed for the first time the interaction potential of (E)-1-(4-aminophenyl)-3-phenylprop-2-en-1-one (C1), (E)-1-(4-aminophenyl)-3-(4-methoxyphenyl)-prop-2-en-1-one (C4), (E)-1-(4-aminophenyl)-3-(4ethoxyphenyl)-prop-2-en-1-one (C9) chalcones through in silico approach. The molecular docking and the molecular electrostatic potential results indicated that the chalcones analyzed presented a strong interaction with the Leishmania major receptor, with affinity energy similar to the ligand co-crystallized. Besides, the interaction potential energy analysis from molecular dynamics simulations indicated the C9 ligand interacted more strongly than the 4-bromo-2,6-dichloro-N-(1,3,5-trimethyl-1H-pyrazolyl) benzenesulfonamide ligand with the Leishmania major receptor, especially for the Phe 88, Tyr 217 and His 219 residues. Therefore, the C9 chalcone might potentially treat Leishmaniasis disease.Communicated by Ramaswamy H. Sarma.

EXECUÇÃO DE AUDITORIA INTERNACIONAL DE FORMA HIBRIDA DURANTE A PANDEMIA DO COVID-19

Garantir a segurança quanto ao risco de contaminação do COVID-19 durante um processo de auditoria híbrido, com auditores presenciais e on-line.  Os efeitos gerados pela pandemia COVID-19, trouxe a necessidade de mudança e adaptação em vários conceitos de negócios e a execução de auditorias externas foi um deles. Tratando-se de um processo com avaliadores internacionais, os efeitos foram ainda maiores devido o fechamento de fronteiras, riscos de contaminação, entre outros itens conhecidos. A preocupação para execução deste procedimento foi garantir que as políticas e as boas práticas minimizassem a exposição a patógenos respiratórios, incluindo o SARS-CoV-2.  Desta forma, tendo em vista a grande possibilidade de transmissibilidade, as medidas de prevenção e controle junto aos auditores deste processo foram implementadas em todas as etapas, desde a seleção de auditores pois alguns poderiam apresentar um risco acrescido devido a alguma comorbidade, hospedagem, deslocamento, orientação aos procedimentos a serem utilizados no serviço, durante toda a auditoria e até seu retorno. Estabelecer uma política de segurança durante a execução de visita de acreditação e reacreditação em serviços de bancos de sangue, serviços de transfusão e de terapia celular no padrão AABB/ABHH com auditores presenciais e on line.  Padronizar protocolo de segurança, seleção de auditores que não apresentavam nenhuma comorbidade que pudesse acarretar em risco acrescido, treinamentos quanto ao novo fluxo e uso de Equipamentos de Proteção Individual (EPI), fluxo durante os deslocamentos, reuniões, refeições, hospedagem e todo o processo de auditoria.  Avaliar a possibilidade de aceitação dos serviços quanto ao recebimento dos auditores presenciais e on line.  Analisar a autorização de execução de auditor internacional de forma on lie pela AABB. Foi padronizada a política de segurança, elaboração de procedimento operacional e treinamento de todos os auditores antes da execução da auditoria.  Executado levantamento de toda a segurança necessária para execução das visitas de acreditação e reacreditação nos serviços de bancos de sangue, serviços de transfusão e de terapia. Apresentado a política e o procedimento operacional a todos os serviços e com aceite de todos quanto a execução.  Executado análise de saúde do auditor antes e durante e no término das auditorias. Implementado fluxo com uso de plataformas on-line para que os auditores internacionais pudessem avaliar os processos em tempo real.  Execução de reunião de abertura, fechamento e durante avaliação entre auditores brasileiros e internacionais sem nenhum dano neste fluxo.  Executado análise de todos os serviços quanto a mudança na execução de auditoria e o resultado quanto a aprovação foi unanime.  Consideramos que a mudança foi necessária, com minimização de riscos, custos e desgastes e aumento quanto a confiabilidade de todos os serviços/clientes quanto a execução, podemos afirmar que este processo foi de caráter positivo e que permanecerá como uma segunda opção dentro deste ciclo.  Com um protocolo de trabalho padronizado, testes validados e executados de forma controlada, todos os envolvidos orientados e respeitando os critérios de segurança garantimos que mesmo com um risco quanto a contaminação do COVID-19 todas as auditorias foram executadas de forma confiável tendo resultado de 100% quanto a segurança, confiabilidade, satisfação do cliente e de todos os participantes.

Manual versus semiautomatic segmentation of soft-tissue sarcomas on magnetic resonance imaging: evaluation of similarity and comparison of segmentation times

Objective

To evaluate the degree of similarity between manual and semiautomatic segmentation of soft-tissue sarcomas on magnetic resonance imaging (MRI).

Materials and Methods

This was a retrospective study of 15 MRI examinations of patients with histopathologically confirmed soft-tissue sarcomas acquired before therapeutic intervention. Manual and semiautomatic segmentations were performed by three radiologists, working independently, using the software 3D Slicer. The Dice similarity coefficient (DSC) and the Hausdorff distance were calculated in order to evaluate the similarity between manual and semiautomatic segmentation. To compare the two modalities in terms of the tumor volumes obtained, we also calculated descriptive statistics and intraclass correlation coefficients (ICCs).

Results

In the comparison between manual and semiautomatic segmentation, the DSC values ranged from 0.871 to 0.973. The comparison of the volumes segmented by the two modalities resulted in ICCs between 0.9927 and 0.9990. The DSC values ranged from 0.849 to 0.979 for intraobserver variability and from 0.741 to 0.972 for interobserver variability. There was no significant difference between the semiautomatic and manual modalities in terms of the segmentation times (p > 0.05).

Conclusion

There appears to be a high degree of similarity between manual and semiautomatic segmentation, with no significant difference between the two modalities in terms of the time required for segmentation.

Sessão de reiki em profissionais de uma universidade pública: ensaio clínico randomizado

Objetivo: Avaliar a efetividade da terapia reiki em profissionais de uma universidade pública por meio da percepção de bem-estar subjetivo. Método: Trata-se de um ensaio clínico randomizado, simples cego, com grupo experimental e controle. Vinte e oito profissionais participaram da pesquisa. Após alocação nos grupos, o experimental recebeu três sessões de reiki e o controle três sessões falsas. Resultados: o teste ANOVA mostrou significância na redução da dimensão “afeto negativo” no grupo experimental (p=0,023). Conclusão: O reiki reduz o “afeto negativo”, dessa maneira, essa terapia pode reduzir sensações desagradáveis em trabalhadores, mostra-se uma ferramenta eficaz para o cuidado.

Momordica charantia L. extracts against Aedes aegypti larvae

Mormodica charantia (Curcubitaceae) is a plant with great medicinal potential, also used as an alternative of mosquitoes control as demonstrated by previous studies. We evaluated the larvicidal activity of crude extracts of ethyl acetate, methanol and hexane from flowers and fruits of M. charantia against Aedes aegypti (Culicidae). Flowers and fruits were macerated in methanol, ethyl acetate and hexane. Bioassays were performed with application of the extracts at final concentrations of 1 - 200 µg/mL in the middle of the third instar larvae of A. aegypti (L3). The results showed high toxicity to ethyl acetate extracts from flowers and fruits at concentrations of 200 µg/mL and 100 µg/mL, with 97% and 87% of larvae mortality (L3), respectively. Hexane extract demonstrated low toxicity, while methanol extract exhibited 78% larval mortality. The data suggested that the ethyl acetate extracts of flowers and fruits of M. charantia can effectively contribute to larvicidal activity. In addition, purification of M. charantia extracts may lead to a promising larvicidal activity to control the A. aegypti population.

Rescue and vegetative propagation of Eremanthus erythropappus (DC.) MacLeish in natural stand

The native stands of 'candeia' (Eremanthus erythropappus) have been explored through management plans due to the economic potential of essential oil. The rescue of adult trees, as well as the application of silvicultural techniques that favor the restoration of the stand, can contribute to the genetic conservation of this species. This study's objective was to assess the efficiency of propagation techniques for the rescue of 26 matrices of 'candeia' in a natural managed stand and discussion about the rhizogenesis. In August 2017, trees were induced to regrowth by coppice, followed by exposure and scarification of roots. The emergence of shoots and morphology were evaluated according to the origin (i.e., stump or root). After that period, 19 matrices had their sprouts collected for the preparation of apical cuttings. Indole-3-butyric acid (IBA) was applied at the base of the cuttings. Cutting survival at greenhouse exit (GE), rooting at shade house exit (SHE), morphology and root anatomy were evaluated. In 189 days, the scarification of roots promoted 76.92% of budding. The percentage of sprouted matrices, number of shoots per matrice, length, diameter, and shoot length/diameter ratio increased over time. Only 12.2% of the cuttings survived in GE, and of these, 7.9% rooted in SHE. The cutting resulted in the formation of a clonal mini-garden of 'candeia', with seven of the 19 matrices submitted to propagation. The anatomical analyses showed that bud formation occurs from cell redifferentiation in the phloem parenchyma, and presence of crystals on the walls of the vessel elements of the secondary xylem. The shoots induction from scarification of roots could be used as a silvicultural practice for the reestablishment of the native fragments handle.

The impact of two root canal treatment protocols on the oral health-related quality of life: a randomized controlled pragmatic clinical trial

AIM

To assess the impact of two root canal treatment protocols on the oral health-related quality of life (OHRQoL) of patients in need of root canal treatment on their anterior teeth.

METHODOLOGY

The sample consisted of 120 participants (mean age: 34 years) enrolled in a pragmatic randomized clinical trial evaluating two root canal treatment protocols. Anterior teeth with nonvital pulps were allocated for root canal preparation with either hand files and filled with lateral compaction of gutta-percha (manual protocol) or canal preparation with a single file in a reciprocating movement and filled with a single cone technique (Reciproc protocol). OHRQoL data were assessed using the Oral Health Impact Profile instrument (OHIP-14), which was administered before the root canal intervention (baseline), and 6 and 12 months after treatment. Demographic and clinical characteristics of participants were collected at baseline. Data were analysed using bivariate analyses, Poisson univariate and multiple regression (α = 0.05).

RESULTS

The drop-out rate from baseline was 27% and 28% at 6 and 12 months after treatment, respectively. Both root canal protocols significantly enhanced patients' OHRQoL, regardless of the follow-up time (P < 0.001). After 6 months, patients treated with the Reciproc protocol had significantly lower OHIP-14 overall scores (P = 0.030), as well as significantly lower scores for psychological discomfort (P = 0.031) and social disability (P = 0.013). After 12 months, no significant difference was observed between the two root canal protocols for OHIP-14 overall scores (P = 0.174). Either large or moderate effect sizes were observed for all domains and overall scores at both evaluation times, irrespective of the protocol. Low-income persons (RR = 2.03) and the Reciproc protocol (RR = 1.52) had a higher likelihood of a positive impact on OHRQoL 12 months after root canal treatment.

CONCLUSIONS

The two root canal protocols improved the OHRQoL and differences in scores were observed only after 6 months with poorer OHRQoL for the manual protocol. After 12 months, patients with low-income status and treated with Reciproc were associated with a greater improvement in OHRQoL scores.

0663 The Longterm Effect of CPAP Compared to Mandibular Advancement Device on Metabolic Profile in Mild Obstructive Sleep Apnea

Introduction

Moderate and severe Obstructive Sleep Apnea (OSA) have been independently associated to dyslipidemia with controversial results of improvement with CPAP. Less evidence exists regarding this issue in mild OSA. A current treatment for mild OSA is Mandibular Advancement Device (MAD), however its effectiveness on metabolic profile needs to be compared to CPAP.Our aim was to compare MAD with CPAP and no treatment on metabolic profile during one year in mild OSA.

Methods

Cross sectional analyses included 79 mild OSA patients randomized in CPAP group (n: 31), MAD group (n. 25) and Control group (n: 23). Metabolic profile was investigated before and after 6 and months.

Results

Mean age: 47± 9 years, BMI: 28±3.7 kg/m AHI: 9.5±2.9/h. There were no differences in anthropometric data, total cholesterol (TCT) HDL-C, LDL-C, Triglycerides (TC) and glycated Hemoglobin (Hb1c) among groups. MAD and CPAP reduced AHI at 6 and 12 months (9.3 ± 5.2 to 4.2 ± 9.1 to 3.8 ± 12.6 / 10.0 ± 4.6 to 1.2 ± 9.9 to 1.7 ± 14.2, p: 0.01 respectively). BMI did not change in groups at 6 and 12 months. MAD adherence was higher than CPAP at 6 months (5.8 ± 2.8 hs/day vs 3.8 ± 3.0 hs/day; p: 0.01) and 12 months 5.7 ± 2.7 hs/day vs 3.8 ± 3.4 hs/day; p: 0.01). Despite of lower adherence than MAD, CPAP was effective in reduce TCT and LDL- CT at 6 and 12 months (Intention to treat analyses TCT: 189.3±51.4 mg/dl to 186.1±51.4 mg/dl to 174.6±51 mg/dl; p: 0.03 / 112.8±48.7 mg/dl to 110.5±48.7 mg/dl to 95.8±48.7mg/dl; p: 0.03 respectively), however HDL-C, TG and Hbc didn′t change.

Conclusion

Long term CPAP treatment was effective in reducing cholesterol in mild OSA.

Support

Associação Fundo Incentivo à Psicobiologia (AFIP)

CAPES

Manual and semiautomatic segmentation of bone sarcomas on MRI have high similarity

The aims of this study were to evaluate the intra- and interobserver reproducibility of manual segmentation of bone sarcomas in magnetic resonance imaging (MRI) studies and to compare manual and semiautomatic segmentation methods. This retrospective study included twelve osteosarcoma and eight Ewing sarcoma MRI studies performed prior to any therapeutic intervention. All cases were histopathologically confirmed. Three radiologists used 3D-Slicer software to perform manual segmentation of bone sarcomas in a blinded and independent manner. One radiologist segmented manually and also performed semiautomatic segmentation with the GrowCut tool. Segmentation exercises were timed for comparison. The dice similarity coefficient (DSC) and Hausdorff distance (HD) were used to evaluate similarity between the segmentation results and further statistical analyses were performed to compare DSC, HD, and volumetric results. Manual segmentation was reproducible with intraobserver DSC varying from 0.83 to 0.97 and HD from 3.37 to 28.73 mm. Interobserver DSC of manual segmentation showed variation from 0.73 to 0.97 and HD from 3.93 to 33.40 mm. Semiautomatic segmentation compared to manual segmentation resulted in DSCs of 0.71−0.96 and HDs of 5.38−31.54 mm. Semiautomatic segmentation required significantly less time compared to manual segmentation (P value ≤0.05). Among all situations compared, tumor volumetry did not show significant statistical differences (P value >0.05). We found excellent intra- and interobserver agreement for manual segmentation of osteosarcoma and Ewing sarcoma. There was high similarity between manual and semiautomatic segmentation, with a significant reduction of segmentation time using the semiautomatic method.

Validation of the Visible Occlusal Plaque Index (VOPI) in estimating caries lesion activity

OBJECTIVE

The present study appraises the construct validity of the Visible Occlusal Plaque Index (VOPI) along with its sub-types, convergent and discriminant validity.

METHODS

618 10-15year old Brazilian adolescents were included. The VOPI has a four-point ordinal scale ranging from no plaque to heavy plaque. VOPI scores and caries status on permanent molars were mapped and recorded at individual anatomical sites of the groove-fossa-system and at surface level. Outcomes were presence of sound site/surface and site/surface with active or inactive caries lesions (non-cavitated or cavitated).

RESULTS

Construct validity was assumed based on qualitative assessment as no plaque (score 0) and thin plaque (score 1) reflected the theoretical knowledge that a regular disorganization of the dental biofilm either maintains the caries process at sub-clinical levels or inactivate it clinically. The VOPI also showed convergent validity since the likelihood that anatomical sites with no or thin plaque had inactive lesions simultaneously with sites with thick plaque (score 2) or heavy plaque (score 3) having active lesions were overall significant (RR=1.0-7.8). At surface level, discriminant validity of the VOPI was evidenced with multivariable analysis (GEE), by its ability to discriminate between the groups of adolescents with different oral hygiene status; negative association between adolescents with thick and heavy plaque and those with sound occlusal surfaces was found (OR=0.3, p<0.001).

CONCLUSION

The VOPI has construct as well as convergent and discriminant validity and is therefore recommended as an additional clinical tool to estimate caries lesions activity and support treatment decisions.

CLINICAL SIGNIFICANCE

The Visible Occlusal Plaque Index is an additional clinical tool to the assessment of oral hygiene and caries lesion activity. The VOPI is recommended to standardize and categorize information on the occlusal biofilm, thus being suitable for direct application in research and clinical settings.

Perineal trauma after vaginal delivery in healthy pregnant women

CONTEXT AND OBJECTIVE

Despite all the medical care provided during delivery labor, perineal injury is still prevalent and may lead to diverse pelvic floor disorders. The aim here was to investigate the prevalence of obstetric and anal sphincter injuries (OASIS) in healthy pregnant women after vaginal delivery.

DESIGN AND SETTING

Cross-sectional study involving 3,034 patients with singletons in a secondary hospital for low-risk cases.

METHODS

A standardized questionnaire was prepared and applied to medical files that had been completely filled out (classification of the Royal College of Obstetricians and Gynecologists, RCOG) in order to identify OASIS and analyze risk factors associated with mild and severe perineal lacerations.

RESULTS

The women's mean age was 25 years; more than half (54.4%) were primiparae. Almost 38% of the participants had perineal lacerations; these were severe in 0.9% of the cases. Previous vaginal delivery (odds ratio, OR: 1.64 [1.33-2.04]) and forceps delivery (OR: 2.04 [1.39-2.97]) were risk factors associated with mild perineal injuries (1st and 2nd OASIS classifications). Only remaining standing for prolonged periods during professional activity (OR: 2.85 [1.34-6.09]) was associated with severe perineal injuries.

CONCLUSION

The prevalence of severe perineal injuries was concordant with data in the literature. The variable of standing position was considered to be a risk factor for severe perineal injury and should be further investigated.

Comparing compression models for authorship attribution

In this paper we compare different compression models for authorship attribution. To this end, three different types of compressors, Lempel-Ziv type (GZip), block sorting type (BZip) and statistical type (PPM), along with two different similarity measures were considered in our experiments. Besides, two different attribution methods are analyzed in this paper. Through a series of experiments performed on two different databases, we were able to show that all the compressors behave similarly, but the similarity measures can vary considerably depending on the strategy used for authorship attribution. Our results corroborate with the literature in the sense that compression models are a good alternative for authorship attribution surpassing traditional pattern recognition systems based on classifiers and feature extraction.

Molecular identification of Rickettsia felis in ticks and fleas from an endemic area for Brazilian Spotted Fever

Rickettsioses are arthropod-borne diseases caused by parasites from the Order Rickettsiales. The most prevalent rickettsial disease in Brazil is Brazilian Spotted Fever (BSF). This work intends the molecular detection of those agents in ectoparasites from an endemic area of BSF in the state of Espírito Santo. A total of 502 ectoparasites, among them Amblyomma cajennense, Amblyomma dubitatum (A. cooperi), Riphicephalus sanguineus, Anocentor nitens and Ctenocephalides felis, was collected from domestic animals and the environment and separated in 152 lots according to the origin. Rickettsia sp. was detected in pools of all collected species by amplification of 17 kDa protein-encoding gene fragments. The products of PCR amplification of three samples were sequenced, and Rickettsia felis was identified in R. sanguineus and C. felis. These results confirm the presence of Rickettsia felis in areas previously known as endemic for BSF, disease caused by Rickettsia rickettsii. Moreover, they show the needing of further studies for deeper knowledge of R. felis-spotted fever epidemiology and differentiation of these diseases in Brazil.

[Electrical stimulation and swimming in the acute phase of axonotmesis: their influence on nerve regeneration and functional recovery]

INTRODUCTION

Little attention has been given to the influence of low-frequency phasic electrical stimulation (LFPES) and physical exercise on the quality of peripheral nerve regeneration and functional recovery. AIM. To evaluate the influence of LFPES, swimming and the association between the two in terms of the morphology of the regenerated sciatic nerve following axonotmesis.

MATERIALS AND METHODS

Thirty Wistar mice (222.05 +/- 42.2 g) were distributed into groups: control (C), denervated (D), denervated + swimming (DS), denervated + electrostimulation (DE) and denervated + swimming + electrostimulation (DSE). After 24 hours of axonotmesis, the soleus muscle of the DE and DSE groups was stimulated electrically. The DS and DSE groups swam over a period of 22 days. The number of axons, morphometric data on the nerve and the functional index of the sciatic nerve (FIS) were evaluated.

RESULTS

The number of axons in the denervated groups was higher than in the control group, and in the DE group the figure was higher than in the D group. The axonal diameter was smaller in the denervated groups, yet in the DS group it was higher than in the D group. The other morphometric parameters were quite similar to those of the C group. The FIS between days 7 and 14 of the post-operative period was different to the pre-operative index and that measured on day 21 of the post-operative period; the DSE group, however, differed from the pre-operative values.

CONCLUSIONS

Swimming and LFPES, applied on an individual basis, do not affect the maturation of the regenerated fibres or functional recovery. LFPES favoured axonal regeneration and combining the treatments delayed functional recovery without having any influence on nerve regeneration.

Inhibition of Na+,K+-ATPase activity from rat hippocampus by proline

Na+,K+-ATPase and Mg2+-ATPase activities were determined in the synaptic plasma membranes from hippocampus of rats subjected to chronic and acute proline administration. Na+,K+-ATPase activity was significantly reduced in chronic and acute treatment by 33% and 40%, respectively. Mg2+-ATPase activity was not altered by any treatment. In another set of experiments, synaptic plasma membranes were prepared from hippocampus and incubated with proline or glutamate at final concentrations ranging from 0.2 to 2.0 mM. Na+,K+-ATPase, but not Mg2+-ATPase was inhibited (30%) by the two amino acids. In addition, competition between proline and glutamate for the enzyme activity was observed, suggesting a common binding site for these amino acids. Considering that Na+,K+-ATPase activity is critical for normal brain function, the results of the present study showing a marked inhibition of this enzyme by proline may be associated with the neurological dysfunction found in patients affected by type II hyperprolinemia.

Proline administration decreases Na+,K+-ATPase activity in the synaptic plasma membrane from cerebral cortex of rats

Buffered proline was injected subcutaneously into rats twice a day at 8 h intervals from the 6th to the 28th day of age. Control rats received saline in the same volumes. The animals were weighed and killed by decapitation 12 h after the last injection. Cerebral cortex was used for the determination of Na+,K+-ATPase and Mg2+-ATPase activities. Body, whole brain and cortical weights were similar in the two groups. Na+,K+-ATPase activity was significantly reduced (by 20%) in membranes from the proline-treated group compared to the controls, whereas Mg2+-ATPase activity was not affected by proline. In another set of experiments, synaptic plasma membranes were prepared from cerebral cortex of 29-day-old rats and incubated with proline at final concentrations ranging from 0.1 to 2.0 mM. Na+,K+-ATPase activity, but not Mg2+-ATPase activity, was inhibited by 20-30%. Since proline concentrations in plasma of chronically treated rats and of type 11 hyperprolinemic children are of the same order of magnitude as those tested in vitro, the results suggest that reduction of Na+,K+-ATPase activity may contribute to the neurological dysfunction found in some patients affected by type II hyperprolinemia.