Toxicity of Mucura (Petiveria alliacea) extracts from the peruvian amazon against Daphnia magna for environmental protection and sustainable development.

Natural products, specifically plant extracts with biological activity and the ability to act as botanical biopesticides are often mistakenly considered nontoxic. Scientific evidence indicates the contrary, and for this reason, the objective of this work was to evaluate the toxicity of extracts obtained from Petiveria alliacea L. (Caryophyllales, Phytolaccaceae) using Daphnia magna Straus (Cladocera, Daphniidae) as a bioindicator to identify the plant extracts and the respective concentrations that present the highest toxicity. Leaves of P. alliacea were collected in the Peruvian amazone. From this material, three types of extract (hexane, ethanolic and aqueous) were prepared, which were used in the bioassays with D. magna to find the least toxic extract. Acute toxicity bioassays with D. magna during 48 h of exposure to hexane, ethanolic, and aqueous extracts yielded median lethal concentration (LC50) values of 26.9, 230.6, and 657.9 mg L-1, respectively. The aqueous extract presented the lowest toxicity, causing minimal D. magna mortality in the range of 6.67 to 13.33% at concentrations of 10 and 100 mg L-1. This result enables the efficient use of this plant species in a sustainable manner with a minimal environmental impact for the future development of natural products for pest control.

Genomic and phenotypic features of Acinetobacter baumannii isolated from oil reservoirs reveal a novel subspecies specialized in degrading hazardous hydrocarbons.

The genus Acinetobacter encompasses biotechnologically relevant species and nosocomial pathogens. In this study, nine isolates recovered from different oil reservoir samples showed the ability to grow with petroleum as the only carbon source and possessed the ability to emulsify kerosene. The whole genomes of the nine strains were sequenced and analyzed. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values of all strains were compared to the reference strains, and the results were below the reference values (<97.88 and 82, respectively), suggesting that the isolates belong to a new subspecies of Acinetobacter baumannii. The name Acinetobacter baumannii oleum ficedula is proposed. A comparison of the whole genome repertoire of 290 Acinetobacter species indicated that the strains in this study resemble non-pathogenic Acinetobacter strains. However, the new isolates resemble A. baumannii when comparing virulence factors. The isolates in this study carry many genes involved in hydrocarbon degradation, indicating the potential to degrade most toxic compounds listed by environmental regulatory agencies such as ATSDR, EPA, and CONAMA. In addition, despite the absence of known biosurfactant or bioemulsifier genes, the strains showed emulsifying activity, suggesting the presence of new pathways or genes related to this process. This study investigated the genomic, phenotypic, and biochemical features of the novel environmental subspecies A. baumannii oleum ficedula, revealing their potential to degrade hydrocarbons and to produce biosurfactants or bioemulsifiers. Applying these environmental subspecies in bioaugmentation strategies sheds light on future approaches to bioremediation. The study shows the importance of genomic analysis of environmental strains and their inclusion in metabolic pathways databases, highlighting unique enzymes/alternative pathways for consuming hazardous hydrocarbons.

Gingival neoplasms: a multicenter collaborative study of 888 patients in Brazil.

BACKGROUND: To evaluate the prevalence and clinicopathological features of a large series of gingival neoplasms in Brazil. MATERIAL AND METHODS:  All gingival benign and malignant neoplasms were retrieved from the records of six Oral Pathology Services in Brazil, during a 41-year period. Clinical and demographic data, clinical diagnosis, and histopathological data were collected from the patients' clinical charts. For statistical analysis, the chi-square, median test of independent samples and the U Mann-Whitney tests were used, considering a significance of 5%. RESULTS:  From 100,026 oral lesions, 888 (0.9%) were gingival neoplasms. There were 496 (55.9%) males, with a mean age of 54.2 years. Most cases (70.3%) were malignant neoplasms. Nodules (46.2%) and ulcers (38.9%) were the most common clinical appearance for benign and malignant neoplasms, respectively. Squamous cell carcinoma (55.6%) was the most common gingival neoplasm, followed by squamous cell papilloma (19.6%). In 69 (11.1%) malignant neoplasms, the lesions were clinically considered to be inflammatory or of infectious origin. Malignant neoplasms were more common in older men, appeared with larger size, and with a time of complaint shorter than benign neoplasms (p<0.001). CONCLUSIONS:  Benign and malignant tumors may appear as nodules in gingival tissue. In addition, malignant neoplasms, especially squamous cell carcinoma, should be considered in the differential diagnosis of persistent single gingival ulcers.

Farmers' perceptions and acceptance of crossbred guinea pigs in Mantaro Valley, Peru.

This study aimed at assessing farmers' perceptions and acceptance of the proposed breeding strategy of Instituto Veterinario de Investigaciones Tropicales y de Altura (IVITA), located in the Central Andes of Peru. A total of 34 farmers, who had received guinea pigs from IVITA, were interviewed. The questionnaire was performed in Spanish language and covered topics about the guinea pig production, feeding, mating system, training, the main products, perception and acceptance of crossbred lines ("cuy RG"), and the farmers' comment about the terminal crossbred animal ("cuy G"). The preferred feeding strategy was a combination of forage and supplement. All farmers implemented a controlled mating system. Most farmers had received training on feeding, reproduction, management, equipment, and facilities. The main product is animals for slaughter. The 82.40% of farmers reported that they do not purchase guinea pigs from IVITA anymore, because they are highly susceptibility to lymphadenitis, which is a highly contagious disease and causes swollen lymph nodes and affects the meat quality. Most of the respondents classified the "cuy RG" and "cuy G" as suitable for meat production and were satisfied with the performance of the animals. Therefore, 58.80% of respondents already recommended "cuy RG" to other farmers. However, 17.70% of the respondents would not recommend these animals because they are susceptible to disease, especially lymphadenitis. Therefore, IVITA should engage in more structured dialogue with farmers and regularly include their opinion in future improvement of its breeding strategies. This could help to reach higher acceptance rates by farmers.

Effect of land use change on the phlebotomine sand fly assemblages in an emergent focus of cutaneous leishmaniasis in Yucatan, Mexico.

As land use intensifies in tropical forests, it is expected that species assemblages will be modified and that key functions of these ecosystems will be affected. The latter scenario is important from a public health perspective, because the land use change has been linked the outbreaks of vector-borne diseases. In this study, we evaluated the response of Phlebotominae (Diptera: Psychodidae) assemblages and their pattern of co-occurrence in four sites with different land use in an emerging cutaneous leishmaniasis focus in Yucatan, Mexico. Our hypothesis is that the conservation status (as forest cover) will positively influence the structure and composition of sand flies' assemblages. Using three different traps over a period of five months, a sampling effort of 1, 440 night-traps was performed. A total of 7, 897 sand fly specimens belonging to six genera and 10 species were collected. Our hypothesis was partially achieved since sand fly diversity increased as forest cover increased and vice versa, however random patterns of co-occurrence in assemblages were detected among sites. Even though the high abundance of sand flies in the forest fragment suggests an amplification effect, our results show that different vector species directly dominate in each site. We discuss the potential implications of the nestedness of species dominance. We suggest that in this emerging focus and under the land use gradient, Lutzomyia cruciata and Psathyromyia cratifer could play a pivotal role in maintaining the transmission cycles of Leishmania. The apparent generalist or colonialist profile of Lu. cruciata in disturbed areas deserves attention, due to the potential risk of leishmaniasis "domiciliation". This information is essential to understand the eco-epidemiology of leishmaniasis and the factors associated with its emergence in Yucatan, Mexico.

The impacts of seasonal variation and climate on food utilization in a population of critically endangered cotton-top tamarins (Saguinus oedipus) in Colombia: A 22-year longitudinal study.

To examine how precipitation patterns and climate change impact feeding choices made by a population of critically endangered cotton-top tamarins (Saguinus oedipus), we examined 22 years of feeding data (1999-2020) from 21 groups collected at Parque Natural Regional Bosque Seco El Ceibal Mono Tití in Santa Catalina, Colombia. We describe the diet and examine the role of seasonal rainfall and annual variation in rainfall on diet. Rainfall is highly seasonal (mean annual rainfall 1562 mm [range 940-2680 mm]) with a dry, early rainy, and late rainy season in each year. Over 80 species of plants formed part of the fruit, nectar, and exudate components of the diet. Fruits, although available year-round, were more commonly available and consumed during the late rainy seasons (August-November). Exudates were consumed more frequently in the dry season (December-March) and invertebrate consumption was stable across the year. Nectar feeding from a single species (Combretum fruticosum) peaked in November. Rainfall varied over the years, with 13 years exceeding the 99% confidence intervals for mean rainfall. Ten of these extreme years (both drought and extremely wet) occurred in the last 11 years. Fruit consumption did not vary between extreme and average years, but cotton-top tamarins consumed more invertebrates and exudates in wet years. Presently, cotton-top tamarins appear to be able to cope with these extreme variations in rainfall due to their highly varied diet. However, the forests that these primates depend upon for survival are threatened by human exploitation making it critically important to maintain a generalist feeding strategy for survival as many fruiting trees that compose a large proportion of the diet are removed. As conservation efforts continue, plant species consumed by cotton-top tamarins provide useful data when selecting species for habitat restoration programs.

Primary non-metastatic omental myofibrosarcoma in a horse / Miofibrossarcoma omental primário não metastático em um cavalo

Myofibrosarcoma in horses is a rare malignant tumor composed predominantly by myofibroblasts. A 15-year-old horse was referred to the Veterinary Hospital of the Federal University of Parana for evaluation of colic signs. Initial physical examination showed icteric mucous membrane and laboratory analysis found anemia, increased serum activity of ALT, GGT, ALP, and bilirubin. In the exploratory laparotomy a highly vascularized abdominal mass in the left hypochondrium region of approximately 50cm x 45cm x 30cm, adhered to the surrounding structures was observed. Due to the size and adhesions to the omentum, the mass was considered surgically unresectable, and euthanasia was performed followed by necropsy. The immunohistochemical and morphological results indicate the diagnosis of myofibrosarcoma since the neoplastic cells immunoexpressed Vimentin, HHF35 and S100. To the authors' knowledge, this is the first equine case of omental myofibrosarcoma described in the literature.

O miofibrossarcoma em cavalos é um raro tumor maligno, composto predominantemente por miofibroblastos. Um equino, de 15 anos de idade, foi encaminhado ao Hospital Veterinário da Universidade Federal do Paraná, para avaliação de sinais de cólica. O exame clínico inicial apresentou mucosas ictéricas e, nos exames laboratoriais, revelou anemia e aumento sérico de ALT, GGT, ALP e bilirrubina. Na laparotomia exploratória, observou-se massa abdominal vascularizada de aproximadamente 50cm x 45cm x 30cm na região do hipocôndrio esquerdo e aderida às estruturas circunvizinhas. Devido ao tamanho e às aderências ao omento, a massa foi considerada irressecável cirurgicamente, portanto foi realizada a eutanásia e a necropsia. Os resultados imuno-histoquímicos e morfológicos indicam o diagnóstico de miofibrossarcoma, visto que as células neoplásicas imunoexpressaram Vimentin, HHF35 e S100. Portanto, esse é o primeiro caso em equinos de miofibrossarcoma omental descrito na literatura.

[Food insecurity levels and associated characteristics in pregnant women in Colombia in 2015]. / Niveles de inseguridad alimentaria y características asociadas en mujeres gestantes de Colombia en el 2015.

INTRODUCTION: Food insecurity is the inability of households to acquire safe, nutritionally adequate food that meets physiological needs for leading a healthy and active life. OBJECTIVE: To describe the levels of food insecurity and associated factors in pregnant women in Colombia. METHODOLOGY: Cross-sectional-analytical study; is a secondary analysis of the 2015 Nutritional Situation Survey of Colombia. 1393 pregnant women between 12 and 48 years old were examined. Food insecurity was assessed using the Latin American and Caribbean Food Security Scale. Sociodemographic, anthropometric and micronutrient characteristics were evaluated. The description of food insecurity distribution was made for each of the selected variables, through absolute and percentage frequencies. To estimate the association between the different variables and food insecurity, we used multivariate Poisson regression models. RESULTS: 60.4% (CI95% 55.6%-64,7%) of pregnant women resided in homes with some degree of food insecurity; severe: 9.4% (CI95% 7.4%-11.9%), moderate: 17.6% (CI95% 13.5%-22.8%) and light: 33.2% (CI95% 28.9%-37.8%); we found that Black/Mulatto/Afro-descendant pregnant women (PR 1.22 CI95% 1.01-1.47), belong to quartile 1 of wealth (PR 2.23 CI95% 1.41-3.68), and residing in the región Atlántica (PR 1.34 CI95% 1.08-1.67), was associated with some food insecurity level. CONCLUSION: A high proportion of pregnant women living in households with some food insecurity level. The pregnant women of low socioeconomic levels and those belonging to the black/mulatto/Afro-descendant ethnic group showed to be the main characteristics associated with residing in households with some degree of food insecurity.

Utility of the combination of hederagenin glucoside saponins and chromane hydrazone in the topical treatment of canine cutaneous leishmaniasis. An observational study.

Canine cutaneous leishmaniasis (CCL) is an emerging zoonotic infection endemic in several countries of the world. Due to variable response to therapy and frequency of relapses, a more effective, safer, and inexpensive treatment is needed. Recently, it was reported that the hederagenin glucoside saponins (SS) and chromane-derived hydrazone (TC2) combined in a 1:1 ratio has high potential in antileishmanial therapy since both compounds alter the survival of Leishmania and the ability to infect adjacent macrophage. Not only the skin permeation and the absorption of an ointment containing 2% TC2 and 2% SS (w/w) was determined in this work, but also the acute dermal toxicity in both in vitro and in vivo assays. Last, the effectiveness and safety of the topical therapy with 2% TC2-2% SS ointment was evaluated in an observational study in dogs with diagnosis of cutaneous leishmaniasis (CL). Both TC2 and SS diffused through pig ear skin and traces of TC2 (but not SS) were detected in the stratum corneum of mice at 6-24 h. Neither TC2 nor SS was detected in plasma. The acute dermal toxicity was negative. Treatment with 2% TC2-2% SS ointment produced a complete long-term clinical cure in 56 dogs (24 females and 32 males) from the Orinoco and Amazonas regions in southeastern Colombia without adverse effects. All dogs have remained disease-free for the last 24 months. In conclusion, these results support the use of this topical therapy as a safer and new first-line local treatment of CCL that could help limit the spread of CL from dogs to humans.

Pitiose gástrica em canino jovem / Gastric pythiosis in a young canine

Pitiose gástrica canina é uma afecção crônica granulomatosa causada pelo pseudo-fungo Pythium insidiosum que ocasiona espessamento trasnsmural do estômago. Relata-se um caso de gastrite fúngica em um canino dobermann de 1 ano, macho, atendido no Hospital Veterinário da Universidade Federal do Mato Grosso, campus Sinop-MT, com sinais clínicos de diarreia escura intermitente, regurgitação, êmese e anorexia progressiva por cerca de três meses. No exame ultrassonográfico, observou espessamento gástrico difuso. Devido ao prognóstico ruim, foi realizado eutanásia. Na macroscopia, havia espessamento difuso da parede do estômago e petéquias multifocais por toda a mucosa. Na microscopia havia acentuado infiltrado inflamatório granulomatoso por toda a submucosa e muscular. Foi realizado coloração de metenamina nitrato de prata de Grocott (GMS), com evidenciação de hifas cenocíticas, raras septação e diâmetro de 6-10µm. A confirmação do diagnóstico e identificação do agente foi realizado através Imuno-histoquímica com anticorpo primário para Pythium insidiosum.

Canine gastric pythiosis is a chronic granulomatous infection caused by the insidious pythi fungus that causes stomach thickening. We report a case of fungal gastritis in a 1-year-old male progressive Doberman canine treated at the Veterinary Hospital of the Federal University of Mato Grosso, Sinop-MT campus, with clinical signs of intermittent diarrhea, regurgitation, vomiting and anorexia for about three months. On ultrasound examination, diffuse gastric thickening was observed. Due to the poor prognosis, euthanasia was performed. Macroscopically, there was diffuse thickening of the stomach wall and multifocal petechiae throughout the mucosa. On microscopy, there was a marked granulomatous inflammatory infiltrate throughout the submucosa and muscle Production of Grocott silver nitrate methenamine (GMS) was performed with evidence of cenocytic hyphae, rare septation and diameter of 6-10µm. Confirmation of the diagnosis and identification of the agent was performed through Immunohistochemistry with primary antibody to Pythium insidiosum.

Nonendodontic periapical lesions: a retrospective descriptive study in a Brazilian population.

BACKGROUND: Several nonendodontic diseases can occur in the periapical region, resembling endodontic inflammatory conditions. Therefore, the aim of the present study was to determine the frequency of nonendodontic periapical lesions diagnosed in a Brazilian population. MATERIAL AND METHODS: The files of two Oral Pathology laboratories were reviewed and all cases including at least one clinical diagnosis of endodontic periapical lesions were selected for the study. After initial selection, demographic and clinical data, clinical diagnosis and final diagnosis were reviewed and tabulated. Final diagnosis included endodontic periapical lesions, and benign and malignant nonendodontic periapical lesions. Data were descriptively and comparatively analyzed among the three groups, with a significance level of 5% (p<0.05). RESULTS: Nonendodontic periapical lesions were identified in 208 (19%) out of the 1.125 registries included in the final sample. Benign nonendodontic periapical lesions (200 cases, 18%) were mostly odontogenic keratocysts, ameloblastomas, nasopalatine cysts, dentigerous cysts, glandular odontogenic cysts, and benign fibroosseous lesions. Malignant nonendodontic periapical lesions (8 cases, 1%) included carcinomas, adenocarcinomas, and melanoma. In general, nonendodontic periapical lesions were more common in males and in the posterior mandible (p>0.05). CONCLUSIONS: The frequency of nonendodontic periapical lesions was high and, although the general distribution was similar to the results from other populations, some features were probably associated with the profile of the studied populations and to the methods applied in the present study. Knowledge on differential diagnosis of endodontic and nonendodontic periapical lesions is essential to avoid unnecessary treatments and diagnostic delay in routine dental practice.

Mycobacterium avium subspecies paratuberculosis and bovine leukemia virus seroprevalence and associated risk factors in dairy herds in Minas Gerais state, Brazil / [Soroprevalência do Mycobacterium avium subespécie paratuberculosis e vírus da leucemia bovina e fatores de risco associados em rebanhos leiteiros de Minas Gerais, Brasil]

Mycobacterium avium subesp. paratuberculosis (MAP) e o vírus da leucemia bovina (BLV) são agentes que causam grandes perdas econômicas nos rebanhos. O objetivo deste estudo foi avaliar a situação epidemiológica da paratuberculose bovina (PTB) e leucose enzoótica bovina (EBL) em rebanhos leiteiros de Lagoa Formosa, Minas Gerais, Brasil. Foram coletadas 236 amostras de sangue de vacas, as quais foram submetidas aos testes ELISA e imunodifusão em gel de ágar para detecção de anticorpos contra MAP e BLV. A soroprevalência de anticorpos contra MAP e BVL foi de 20% para os rebanhos e 6% para os animais e de 85% para os rebanhos e 50,42% para os animais, respectivamente. A presença dessas enfermidades deve servir como um alerta para os produtores e veterinários, para que concentrem maior atenção na implementação de medidas higiênico-sanitárias, incorporando elementos de vigilância com base nos riscos identificados no estudo.(AU)

Control of the growth of Alicyclobacillus acidoterrestris in industrialized orange juice using rosemary essential oil and nisin.

The use of rosemary essential oil (RO) and its combination with nisin (RO+N) in preventing the multiplication of Alicyclobacillus acidoterrestris in orange juice was evaluated. The minimum inhibitory and bactericidal concentrations (MIC and MBC) for RO were both 125 µg ml-1 while RO+N displayed a synergistic effect. The use of RO and RO+N at concentrations of 1, 4 and 8× MIC in orange juice for 96 h was evaluated in terms of their sporicidal effectiveness. With regard to the action against A. acidoterrestris spores, RO at 8× MIC was sporostatic, whereas RO+N at 1× MIC was sporicidal. Morphological changes in the structure of the micro-organism after treatment were also observed by microscopy. Furthermore, flow cytometric analysis showed that most cells were damaged or killed after treatment. In general, the antioxidant activity after addition of RO+N decreased with time. The results demonstrate that using the combination of RO and nisin can prevent the A. acidoterrestris growth in orange juice.

Prognostic value of neutrophil-to-lymphocyte ratio in advanced cancer patients receiving immunotherapy.

BACKGROUND: The prognostic value of neutrophil-to-lymphocyte ratio (NLR) has been extensively studied in cancer patients. However, the performance of NLR as an early marker of efficacy of immune checkpoint inhibitors (ICI) is still understudied. We studied the utility of NLR at baseline (bNLR), before the second dose of immunotherapy (NLR2) and the NLR trend for predicting efficacy outcomes. METHODS: We included all patients with advanced cancer treated with ICI from June 2013 to April 2019 at La Paz University Hospital, Madrid (Spain). We examined bNLR, NLR2 and NLR trend and explored the association with progression-free survival (PFS) at 6 months, median PFS and overall survival (OS). RESULTS: We included 211 patients. PFS and OS were significantly longer in the low bNLR group than in the high bNLR group [HR 0.71 (95% CI 0.60-0.84) and HR: 0.66 (95% CI 0.55-0.79), respectively]. Regarding NLR2, patients with low NLR2 had significantly longer PFS and OS than patients with high NLR2 [HR 0.67 (95% CI 0.57-0.79) and HR: 0.60 (95% CI 0.50-0.72), respectively]. Finally, for NLR trend, PFS and OS for patients with NLR trend < 1 were significantly longer than those patients with NLR trend ≥ 1 [HR 0.59 (95% CI 0.43-0.82) and HR 0.63 (95% CI 0.44-0.90), respectively]. At the multivariate analysis for PFS and OS, bNLR, NLR2 and NLR trend were all independent prognostic factors for PFS and OS. CONCLUSIONS: bNLR, NLR2 and NLR trends are independent prognostic factors for survival in patients on immunotherapy. The dynamics of NLR in patients on immunotherapy is a promising marker that needs further investigation.

Treatment strategy optimization for patients with non-small-cell lung cancer harboring EGFR mutation: a Delphi consensus.

AIM: To stablish a consensus on the treatment strategy for advanced non-small-cell lung cancer (aNSCLC) with epidermal growth factor receptor mutation (EGFRm) in Spain. METHODS: After a systematic literature review, the scientific committee developed 33 statements in 4 fields: molecular diagnosis (10 items); histologic profile and patient clinical characteristics (7 items); first-line (1L) treatment in EGFRm aNSCLC (8 items); and subsequent-line treatment (8 items). A panel of 31 experts completed 2 Delphi online questionnaires rating their degree of agreement/disagreement for each statement through a 1-9 range scale (1-3 = disagree, 7-9 = agree). Consensus was reached if 2/3 of the participants are in the median range. RESULTS: In the first Delphi round consensus was achieved for 24/33 of the statements. One of the assertions was deleted, proceeding to a second round with the eight remaining questions with no consensus or in the range of indeterminacy. Determination of the EGFR status from tissue and analysis of the different biomarkers are two important variables that influenced treatment decision in patients with aNSCLC. 1L treatment should be the best therapeutic option, independently of the subsequent lines of treatment. For patients with the most common activating mutations osimertinib was considered the most efficient and safe 1L option. In case of disease progression, a new biopsy was needed. CONCLUSIONS: A consensus document is proposed to optimize the treatment strategy for untreated patients with a NSCLC with EGFR sensitizing mutations.

Estimation of genetic parameters for four Peruvian guinea pig lines.

This study aimed to estimate genetic parameters for four guinea pig lines of a crossbreeding scheme. Two paternal lines are selected for growth rate (P1) and feed conversion rate (P2), whereas two maternal lines are selected for growth rate of litter (M1) and litter size at birth (M2). The heritabilities and genetic correlations were estimated with animal linear models employing multivariate analyses with REML. The heritabilities for birth weight (BW) were 0.21±0.02 and 0.23±0.03 for P1 and P2, respectively, and for weaning weight (WW), the heritability was 0.28±0.03 for P2. The estimates for weight at 60 days of age (W60) were 0.34±0.01 and 0.47±0.04 for P1 and P2, respectively, and for partial feed conversion rate was 0.46±0.03 for P2. Heritabilities for litter weight at birth (LW) were 0.09±0.03 and 0.10±0.03 for P1 and M1, respectively. For litter weight at 10 days of age (LW10), the heritability was 0.15±0.03 for M1. Heritabilities for litter size (LS) were 0.17±0.03, 0.20±0.03 and 0.11±0.03, and for number of pups born alive (BA) were 0.09±0.03, 0.14±0.03 and 0.09±0.03 for P1, M1 and M2, respectively. Similarly, high genetic correlations were found between BW, WW and W60 and between LW, LS, LW10 and BA. The genetic correlation between BW direct and maternal was moderately negative (- 0.24 ± 0.10) for P1. These results show the genetic status for all four guinea pig lines, which is essential for the further improvement of the currently implemented breeding programme and also indicate an opportunity for genetic improvement.

Invasive electrical impedance myography at different levels of contraction of gastrocnemius muscle of rat.

Electrical impedance myography (EIM) is as an experimental technique that associates muscle impedance with muscular activity. Changes in muscle impedance during contraction occur mainly due to changes in the morphological and physiological characteristics of muscles that lead to different impeditivities in comparison with the resting condition. There is no consensus on the details of muscular impedance during muscle activity. EIM measurements on humans are also influenced by factors such as the electrode-skin interface, layers of skin and fat, and the connective tissue that can generate undesirable effects in the impedance signal. These effects can be avoided if EIM measurements are carried out directly on the muscle by using the models of animals. This study investigates changes in the EIM signal in the gastrocnemius muscles of Wistar rats during different levels of muscular contraction. In vivo experiments were conducted on 19 male rats. The muscle was exposed, fixed on a load cell, and electrically stimulated to evoke different levels of muscle contraction. Signals of the components of impedance were analyzed against the muscular force signal. The results show moderate correlations (p < 0.05) among the impedance-related parameters of resistance (r = -0.76), reactance (r = 0.57), and phase (r = 0.53). In addition to providing an experimental protocol for the invasive collection of data on electrical impedance to minimize problems associated with surface electrodes, this study shows that of the components of impedance, resistance is most affected by the intensity of muscular contractions and that morphological changes influence impedance mainly at low intensities.