Identification of SARS-CoV-2 in urban rodents from Southern Mexico City at the beginning of the COVID-19 pandemic

ABSTRACT Currently, there are some concerns about the situation and, in particular, about the future of the COVID-19 pandemic and the new emerging variants of SARS-CoV-2. Rodents are an example of synanthropic animals in urban environments that harbor important zoonoses. Although the molecular identification of SARS-CoV-2 in Rattus norvegicus from New York City had been reported, in other studies, urban wild rodents infected with this virus have not been found. This study aimed to molecularly identify the presence of SARS-CoV-2 in urban wild rodents from Mexico City, trapped along a water channel of a public park as part of a pest control program, at the beginning of the COVID-19 pandemic, during the fall and winter of 2020. Up to 33 Mus musculus and 52 R. norvegicus were captured and euthanized, large intestine samples with feces from the animals were obtained. RNAs were obtained and subjected to qRT-PCR for SARS-CoV-2 identification and threshold cycle (Ct) values were obtained. Four mice (12.1%) and three rats (5.8%) were positive, three rodents exhibited Ct<30. Our results on the frequency of SARS-CoV-2 in urban rats are in line with other previous reports. Thus, similar to other authors, we suggest that surveillance for the detection of SARS-CoV-2 in urban wild rodents, as sentinel animals, should be maintained.

Evaluation of aversive behavior in Rattus norvegicus experimentally infected by two distinct strains of Toxoplasma gondii (ME49 and VEG): study of epigenetic markers

ABSTRACT Background: Behavioral changes in Rattus norvegicus infected with two strains of Toxoplasma gondii (ME49 and VEG) were investigated. Methods: Rats were evaluated for motor activity and aversion or attraction to cat urine 60 days after infection. After euthanasia, arginine-vasopressin gene methylation in the central nervous system was evaluated. Results: A significant difference was observed in the methylation of the arginine-vasopressin promoter gene between rats infected with the ME49 and VEG strains. Conclusions: Although differences were not observed in many parameters, significant differences were observed in the methylation of the arginine-vasopressin promoter gene in rats infected with the two studied strains.

La relevancia moral del dolor de animales de experimentación y de producción / The moral relevance of pain in experimental and production animals

RESUMEN: El aspecto emocional del dolor no solo es controvertido en aves, peces y roedores, sino también en los seres humanos autoconscientes. Cuando el dolor emocional, o la insatisfacción, es vista como un mal intrínseco, evitarla o, al menos, minimizarla es un deber moral directo. El objetivo de este artículo es mostrar que no solo los modelos animales mamíferos que se utilizan en experimentación -rata (Rattus norvegicus) y ratón (Mus musculus)- sienten dolor, como reconocen universalmente las instituciones que se ocupan del bienestar animal, sino también los peces de laboratorio (Danio rerio) y los de producción (Salmo salar), y que este hecho es moralmente relevante desde el punto de vista de todas las concepciones de la moral que suelen enfrentarse en los debates morales públicos y académicos. En consecuencia, también en el caso de los peces habría que tener en cuenta indicadores de bienestar animal.

SUMMARY: The emotional aspect of pain is not only controversial in fish and rodents, but also in self-conscious humans. When pain or dissatisfaction is seen as an intrinsic evil, avoiding it or at least minimizing it is a moral duty direct. The objective of this article is to refer to pain, stress and the most widely used indices of animal welfare both in laboratory fish (Danio rerio) and production fish (Salmo salar) as well as in rat experimental animal models (Rattus norvegicus) and mouse (Mus musculus).

Hydroalcoholic extract of leaves of Arrabidaea brachypoda (DC. ) Bureau present antispasmodic activity mediated through calcium influx blockage

Aim: Since other species of the Bignoniaceae Family presented of antispasmodic activity, it was decided, by chemotaxonomic criterion, to determine the antispasmodic activity of the leaves of Arrabidaea brachypoda. Methodology: the segments of the rat jejunum were suspended in glass vats containing specific saline solution, at an appropriate temperature, and after stabilization period, were stimulated by a contractile agent to observe the inhibitory or relaxing effect of EH-FAB. Results: EH-FAB showed the presence of 10 compounds, mainly rutin and it has an antispasmodic activity as it inhibits the phasic component and relaxes the tonic component of the contraction in isolated rat jejunum. To assess the mechanism of antispasmodic action, cumulative curves to the CCh were performed in which a non-competitive antagonism was observed, due to a displacement of the control curve to the right and reduction of the maximum contraction effect (Emax). Afterward, the participation of the calcium and/or potassium channels was evaluated by increasing the extracellular potassium, and it was observed that the EH-FAB relaxed the rat jejunum, suggesting the participation of the Ca2+ channels. To corroborate that hypothesis, the EH-FAB was tested against cumulative curves to Ca2+ in a free depolarizing solution of Ca2+, and it was observed that there was a shift of the curve to the right with a reduction in Emax. Conclusions: EH-FAB presents antispasmodic activity in isolated rat jejunum and it is suggested to block the influx of Ca2+ through voltage-gated calcium channels, signaling the therapeutic potential for the treatment of colic and/or diarrhea.(AU)

Effect of sex on Toxocara canis larval migration to the cerebellum during experimental infection of Rattus norvegicus

The presence of Toxocara canis third instar larvae in the cerebellum of Rattus norvegicus may alter rodent behavior and movement. In this study, we investigated whether the sex of the rodent affects the migration of larvae to the cerebellum. Thirty-six Rattus norvegicus specimens (18 males and 18 females) were infected with 300 T. canis eggs and were euthanized after 60 days. The cerebellum was removed and treated with 0.5% HCl to recover the T. canis larvae. The number of larvae recovered from male rodents was significantly higher than in females, suggesting that the sex of the animal influences larval migration to the cerebellum

Cryptosporidium spp.: Serum Antibodies and Coproantigens in Brown Rats (Rattus norvegicus) from Grenada, West Indies

The aim of the study was to determine the serum antibodies and coproantigens for Cryptosporidium spp. in brown rats from Grenada. Intestinal contents from 99 and serum from 169 brown rats (Rattus norvegicus) during May to July 2017 were examined for coproantigens and antibodies for Cryptosporidium spp. respectively. Giardia/Cryptosporidium Quick Chek (Tech Lab Inc, USA) was used to detect Cryptosporidium coproantigens in intestinal contents. Prevalence of antigens was 2.02%, signifying active infection. Serum anti-Cryptosporidium antibodies against Cryptosporidium were tested using commercial “qualitative rat Cryptosporidium antibody (Anti-CRY) ELISA kit (My BioSource, Santiago, CA, USA). Serum antibodies were present in 29.5% of the rats indicating a heavy exposure of Cryptosporidium in brown rats from Grenada. The prevalence rate of antibodies in younger rats (up to100g weight) 42.1%, was statistically significant compared to adults (> 100 g) 28.0%. Infected rats in nearby human dwellings may prove a potential Cryptosporidium source of infection to man and animals. This is the first report of Cryptosporidium infection in brown rats in Grenada, West Indies.

First isolation of Laribacter hongkongensis from stool samples of Rattus norvegicus / 中国人兽共患病学报

In order to investigate whether Laribacter hongkongensis could be detected in stool samples of Rattus norvegicus in the wild,Rattus norvegicus were trapped alive in an urban community of Guangzhou,China over a period of one year from June 2015 to May 2016,and their stool samples were examined for the presence of L.hongkongensis strains.Isolates were identified based on phenotypic characteristics and 16S rRNA sequence analysis,and were examined for their susceptibility to 19 antimicrobial agents.Further typing of the isolates was performed using multi-loci sequence typing (MLST) analysis.A total of 191 R.norvegicus were trapped alive.L.hongkongensis was identified and successfully isolated from two samples,representing a prevalence of 1.05 ％.Although the two isolates possessed similar phenotypic characteristics and have no base difference of 16S rRNA gene,they constituted two new distinct sequence types (STs),ST-163 and ST-164.This is the first report that L.hongkongensis can be detected in the intestinal tract of R.norvegicus.Results suggest that R.norvegicus could serve as carriers of L.hongkongensis and therefore could be another potential source of infection.

Implications arising from the use of Cymbopogen proximus ; proximal on placenta of pregnant Albino rats

ABSTRACT Halfa-bar (Cymbopogon proximus), is an aromatic grass widely growing in Upper Egypt. This herb is recommended for medical purposes as an effective diuretic, renal or abdominal antispasmodic agent. Objectives of this study: Evaluate the potential effects of Halfa-bar on the pregnant albino rats during the gestation period. Material and methods: The virgin female rats mated with male then the pregnant rats treated orally with Human Equivalent Dose (HED) of the proximol which equivalent 0.05 mg/ kg rat from 5th -18th Gestational Day (GD). At day 20 of pregnancy, all rats were anesthetized and killed to obtained maternal -fetal data (placenta). Results: The current study indicated that, there is statistically significant (P ≤ 0.05) reduction in the treated placental weight. Also, the light microscopic examination of the placental specimens using haematoxylin and eosin (H&E) staining revealed the presence of various vacuoles in the cytoplasm and nuclei of the giant cells. There is an increase in the number of apoptotic cells and irregular dilatation of maternal sinusoids in the labyrinth zone. Else, microscopic investigation showed a depletion of the glycogen content in the basal and labyrinth layers and a positive caspase-3 in the spongitrophoblast cells. In the treated group, reduction in level of catalase activity (CAT) and significant elevation (P ≤ 0.05) in the level of malondialdehyde (MDA) were recorded. Conclusion: The pathological effects in placenta may be due to the accumulation of proximal and transplacental passage.

Heterogenic colonization patterns by Leptospira interrogans in Rattus norvegicus from urban slums

Abstract We evaluated the renal colonization by Leptospira interrogans in Rattus norvegicus (rats), as it is the major natural reservoir of urban leptospirosis. We caught 72 R. norvegicus, out of which 32 were found to be positive for L. interrogans by immunofluorescence assay. From these rats, we selected 17 and divided them into six groups based on the mass-age/sex. We performed the immunohistochemistry test against L. interrogans in the kidney sections of the rats and systematically counted the colonized tubules (CTs) in 20 fields. The proportion of positive fields varied from 5% to 95%. The number of CTs in 20 fields varied from 0.5 to 85.5. These differences were not related to age or sex of the animals. The characterization of leptospiral colonization patterns in the natural reservoirs is important to better understand the host-pathogen interactions in leptospirosis.

Identificação de biofilme renal em ratos naturalmente infectados por Leptospira interrogans através de técnicas histoquímicas e de microscopia eletrônica de varredura, Brasil / Identification of renal biofilm in rats naturally infected with Leptospira interrogans using histochemical and scanning electron microscopy techniques, Brazil

INTRODUÇÃO: A leptospirose é um importante agravo de saúde pública e afeta ao menos um milhão de humanos por ano no mundo. Ratos de esgoto (Rattus norvegicus) são os principais reservatórios de leptospiras patogênicas nas áreas urbanas e excretam, através da urina, elevadas quantidades de bactérias diariamente. As leptospiras sobrevivem no ambiente e são transmitidas para novos hospedeiros através do contato com mucosas e pele. Leptospiras patogênicas formam densos biofilmes in vitro. A patogênese da leptospirose em reservatórios crônicos é pouco conhecida. OBJETIVO: Estudar a formação de biofilme por Leptospira interrogans em R. norvegicus capturados em uma área hiperendêmica de Salvador, Bahia, Brasil. MATERIAIS E MÉTODOS: Capturamos 86 ratos, dos quais 76 (88,4%) foram considerados portadores de L. interrogans através da avaliação por imunohistoquímica (IHQ) anti-L. interrogans e/ou Reação em Cadeia da Polimerase quantitativa em Tempo Real (RT-qPCR) utilizando iniciadores específicos para o gene lipL32. RESULTADOS: Ao exame de IHQ anti-L. interrogans, 69 ratos foram positivos. Destes, 24 (35%)...

INTRODUCTION: Leptospirosis is an important public health problem and affects at least one million people each year worldwide. Norway rats (Rattus norvegicus) are the main reservoir hosts of leptospires in urban environments. They excrete large amounts of bacteria daily. Leptospires survive in the environment and are transmitted to new hosts by contact with mucous membranes and skin. Pathogenic leptospires form dense biofilms in vitro. The pathogenesis of chronic leptospirosis in reservoirs is largely unknown. The aim of this work was to study biofilm formation by Leptospira interrogans in R. norvegicus caught in a hyperendemic area in Salvador, Bahia, Brazil. MATERIAL AND METHODS: We caught 86 rats, out of which 76 (88.4%) were carriers of L. interrogans according to immunohistochemistry (IHC) anti-L. interrogans and/or quantitative real time PCR (RT-qPCR) using LipL32 primers. RESULTS: From the 69 rats positive for IHC anti-L. interrogans, 24 (35%)...

Brazilian Angiostrongylus cantonensis haplotypes, ac8 and ac9, have two different biological and morphological profiles

Angiostrongylus cantonensis is the etiologic agent of eosinophilic meningoencephalitis in humans. Cases have been recorded in many parts of the world, including Brazil. The aim of this study was to compare the differences in the biology and morphology of two different Brazilian haplotypes of A. : ac8 and ac9. A significantly larger number of L1 larvae eliminated in the faeces of rodents at the beginning of the patent period was observed for ac9 haplotype and compared to the total of L1 larvae eliminated, there was a significant difference between the two haplotypes. The ac9 haplotype showed a significant difference in the proportion of female and male specimens (0.6:1), but the same was not observed for ac8 (1.2:1). The morphometric analysis showed that male and female specimens isolated from ac8 haplotype were significantly larger with respect to body length, oesophagus length, spicule length (male) and distance from the anus to the rear end (female) compared to specimens from ac9. The morphological analysis by light microscopy showed little variation in the level of bifurcations at the lateral rays in the right lobe of the copulatory bursa between the two haplotypes. The biological, morphological and morphometric variations observed between the two haplotypes agree with the observed variation at the molecular level using the cytochrome oxidase subunit I marker and reinforce the possible influence of geographical isolation on the development of these haplotypes.

PREVALENCE OF Calodium hepaticum (SYN. Capillaria hepatica) IN Rattus norvegicus IN THE URBAN AREA OF RIO DE JANEIRO, BRAZIL / Prevalência de Calodium hepaticum (sin. Capillaria hepatica) em Rattus norvegicus em área urbana do Rio de Janeiro, Brasil

The nematode Calodium hepaticum (syn. Capillaria hepatica) is a zoonotic helminth found mainly infecting rats. It was studied the prevalence of C. hepaticum infection in Rattus norvegicus in an urban area of Rio de Janeiro (Brazil), with low urban planning and sanitation. The presence of C. hepaticum was identified through visible yellowish-white lesions in liver tissue and histological analyses. The total prevalence of infection was 45%, with no significant differences between sex and age. The presence of infected rodents near the peridomestic area poses substantial risk to human health.

O nematóide Calodium hepaticum (sin. Capillaria hepatica) é um helminto zoonótico encontrado infectando principalmente ratos. A prevalência da infecção de C. hepaticum em Rattus norvegicus foi investigada em área urbana do Rio de Janeiro (Brasil) com baixo planejamento e saneamento. A presença de C. hepaticum foi identificada através da presença de lesões macroscópicas caracterizadas por manchas extensas de coloração branco-amarelada difusa por toda superfície do tecido do fígado e através de análise histológica. A prevalência total da infecção foi de 45% sem diferença significativa entre o sexo e idade. A presença de roedores infectados próximos do peridomicílio representa um risco substancial para a saúde humana.

Rhipicephalus sanguineus sensu lato (Ixodidae) in synantropic rodents in Rio Grande do Sul, Brazil / Rhipicephalus sanguineus sensu lato (Ixodidae) em roedores sinantrópicos no Rio Grande do Sul, Brasil

Rhipicephalus sanguineus, the brown dog tick, is responsible for maintaining and transmitting various pathogens, both in animals and human beings, and it is of great sanitary importance. This communication reports the first occurrence of Rhipicephalus sanguineus sensu lato parasitizing Rattus norvegicus in the state of Rio Grande do Sul, Brazil, and it is also the first record of this tick species parasitizing Rattus rattus in Brazil. The rodents were captured from the port area, located in the city of Pelotas, Rio Grande do Sul, Brazil. We collected 6 larvae of this tick species from 2 male R. rattus individuals, and 3 larvae from 2 female R. norvegicus individuals; parasitized specimens of both rodent species were captured from different sites within the experimental area. This record broadens the number of Rhipicephalus sanguineus sensu lato hosts in urban areas, indicating the need for continued monitoring on population density for both R. sanguineus and synanthropic rodents.

Rhipicephalus sanguineus, carrapato-vermelho-do-cão, é responsável por manter e transmitir diversos patógenos tanto para animais quanto para o homem, sendo de grande importância sanitária. Essa comunicação relata a primeira ocorrência de Rhipicephalus sanguineus sensu lato parasitando Rattus norvegicus no Estado do Rio Grande do Sul e, pela primeira vez, Rattus rattus no Brasil. Os roedores foram capturados na área portuária da cidade de Pelotas, Rio Grande do Sul, Brasil. Foram coletadas seis larvas desse carrapato em dois machos de R. rattus e três larvas em duas fêmeas de R. norvegicus. As duas espécies de roedores parasitados foram capturadas em pontos distintos na área do experimento. Esse registro amplia o número de hospedeiros de Rhipicephalus sanguineus sensu lato em áreas urbanas, indicando a necessidade de monitoramento contínuo da densidade populacional, tanto de R. sanguineus quanto de roedores sinantrópicos.

Alteraciones morfológicas del bazo de ratas (rattus norvergicus), tratadas con trióxido de arsénico / Morphological alterations of the spleen of rats (rattus norvegicus) treated with arsenic trioxide

En América Latina la presencia del arsénico en el ambiente y en las fuentes de agua para consumo humano, se debe a factores naturales de origen geológico como a actividades antropogénicas. El arsénico en las aguas naturales se encuentra principalmente como trivalente (arsenito) o pentavalente (arsenato). El objetivo de este trabajo fue determinar las alteraciones que provoca el trióxido de arsénico a nivel de la morfología del bazo de ratas (Rattus norvegicus - Sprague-Dawley). Se utilizaron 24 ratas de ambos sexos de 55 días de vida. Las ratas fueron pesadas y divididas en 3 grupos (4 hembras y 4 machos). Los grupos tratados fueron inyectados con 5 mg y 10 mg de As2O3 respectivamente, en dosis única diaria vía intraperitoneal por 15 días. Al grupo control se le aplicó agua destilada sin arsénico. Después del tratamiento los animales fueron sacrificados por eutanasia convencional y se obtuvo el bazo, los cuales fueron lavados, pesados y seccionados en cuatro partes, que fueron fijadas en formol tamponado al 10 por ciento. Mediante técnica histológica se obtuvieron 4 muestras seriadas de cada bazo, de 5 micrones de espesor con una separación de 100 micrones entre si. Posteriormente fueron teñidas con H-E. Se analizaron 30 campos (120 campos por órgano). Los datos obtenidos permiten concluir que ratas tratadas con trióxido de arsénico, presentan alteración a nivel de los compartimentos del bazo, con un aumento del compartimento de la pulpa roja, una depleción en el tamaño y número de folículos linfoides y de la zona marginal. A su vez, se observó pérdida de la celularidad de la vaina linfoide periarteriolar (PALS).

In Latin America, the presence of arsenic in the environment and water sources for human consumption is due to natural geological factors and anthropogenic activities. Arsenic in natural waters is mainly found as trivalent (arsenite) or pentavalent (arsenate). The aim of this study was to determine the alterations causing arsenic trioxide-level morphology of the spleen of rats (Rattus norvegicus - Sprague-Dawley). Were used 24 rats of both sexes of 55 days of life. The rats were weighed and divided into 3 groups (4 females and 4 males). The treated groups were injected with 5 mg and 10 mg of As2O3 respectively, intraperitoneally daily dosing for 15 days. The control group was administered arsenic-free distilled water. After treatment the animals were euthanized conventionally, and spleen was removed, which was washed, weighed and sectioned into four parts, which were fixed in 10 percent buffered formalin. Histological technique using four serial samples were obtained from each spleen of 5 microns thick with a spacing of 100 microns between them. Subsequently these were stained with H-E. We analyzed 30 fields (120 fields per organ). The data obtained indicates that rats treated with arsenic trioxide have an altered level of the compartments of the spleen, with an increased red pulp chamber, depletion in the size and number of lymphoid follicles and marginal zone. Furthermore, loss of cellularity of periarteriolar lymphoid sheath (PALS) was observed.

Calodium hepaticum (Nematoda: Capillariidae) in synanthropic rodents (Rattus norvegicus and Rattus rattus) in Eastern Amazonia / Primeiro relato de Calodium hepaticum (Nematoda:Capillariidae) em roedores sinantrópicos (Rattus norvegicus e Rattus rattus) na amazonia oriental

Calodium hepaticum (syn. Capillaria hepatica) is a trichurid nematode that parasitizes the hepatic parenchyma of rodents and other mammals. Infections in humans are rare, although they have been reported worldwide. A number of factors contribute to the distribution of this zoonosis, particularly the presence of dense populations of rodents associated with relatively poor urban environments, such as those found in parts of the northern Brazilian city of Belém in the eastern Amazon Basin. This study quantified Calodium infections in commensal synanthropic rodents in Belém. Rodents were captured in three neighborhoods characterized by poor public sanitation and the city's highest incidence of human leptospirosis. A total of 50 rodents were captured (26 Rattus rattus and 24 R. norvegicus), and 23 (10 R. rattus and 13 R. norvegicus) presented macroscopic lesions typical of C. hepaticum. Light microscopy of fresh samples and histological specimens permitted the identification of larvae and adult specimens containing numerous eggs with a double-striated shell and bipolar opercula with plugs. This is the first report of C. hepaticum in R. rattus and R. norvegicus from the Amazon Basin, and it shows a considerable risk of transmission to the local human population.

Calodium hepaticum (syn. Capillaria hepatica) é um nematódeo trichurídeo parasito de parênquima hepático de roedores e outros mamíferos. As infecções em humanos são raras, mas são relatadas em diversas regiões do mundo. Numerosos fatores contribuem para a distribuição desta zoonose, particularmente, uma densa população de roedores associada com ambientes urbanos com carência de saneamento básico, tais como aqueles encontrados em algumas cidades da região Norte do Brasil, como a cidade de Belém, localizada na Amazônia Oriental. Este estudo quantifica e demonstra a infecção por Calodium em roedores comensais sinantrópicos, de três bairros da cidade de Belém, Estado do Pará, com carência de saneamento público e alta incidência de leptospirose humana. Um total de 50 roedores foram capturados para análise (26 Rattus rattus e 24 R. norvegicus) e destes, 23 (10 R. rattus e 13 R. norvegicus) apresentaram típicas lesões hepáticas, macroscópicas, causadas por C. hepaticum. A análise de amostras por microscopia de luz direta e histopatológica do fígado dos roedores permitiu a identificação de espécimes desse parasito em fase larvar e adulta, além de numerosos ovos apresentando dupla casca estriada e dois tampões operculares. Este é o primeiro registro da ocorrência de C. hepaticum in R. rattus and R. norvegicus na região Amazônica, alertando para um considerável risco de transmissão para a população humana.

Spirulina as a protein source in the nutritional recovery of Wistar rats

This study was aimed at evaluating the effects of Spirulina (Arthrospira) as a protein source in the nutritional recovery of rats subjected to protein malnutrition. In order to understand such effects, responses of the developing body, serum biochemical profile, and blood count of animals were analyzed. A total of, 23 Wistar Rattus norvegicus were given a proteic diet (AIN-93G adapted) in malnutrition phase (phase I) for 10 days. After this period, the rats were separated into four groups according to the protein source (recovery phase): Control (C), casein 12%; Spirulina level I (S1), Spirulina 8.8% + casein 5.0%; Spirulina level II (S2), Spirulina 17.6% + casein 0.15%, and Spirulina level III (S3), Spirulina 26.4%. Recovery phase (phase II) lasted 30 days. In both the phases, the consumption and body weight of the rats were monitored daily and weekly, respectively. The S1 treatment showed the highest values of Feed Efficiency Ratio (FER) and Quotient of Protein Efficiency Ratio (QPE) (p<0.05). Significant differences among the treatments were found mainly in the levels of serum lipids, and S2 diet caused an increase in such responses (p<0.05). These results demonstrated that the nutritional recovery of animals was enabled by different concentrations of Spirulina.

Cyclophosphamide induced changes in certain hematological and biochemical parameters of adult male Rattus Norvegicus.

Background: Cyclophosphamide (CP), [2-(bis-/2-chloro-ethyl-amino)-tetrahydro-2H-1, 2, 3 oxazaphosphorine-2-oxide], is an alkylating chemotherapeutic agent, which is commonly used against malignancies, such as leukemia, lymphoma, breast, lung, prostrate, and ovarian cancer. The aim of this study is to evaluate the side effect of CP on male albino rat in response to certain hematological and hepatic and renal biochemical parameters. Methods: In this investigation, total 20 albino rats were divided in to two groups of ten each. Group first served as control received i.p. injection of 0.9 physiological saline fed with standard food and water ad libitum. While, Group second received a single dose (0.4ml/100g b/w) through i.p. injection of cyclophosphamide once in a week for a period of 7 and 35 days and hematological parameters i.e. Hb%, total count-RBCs, total count-WBCs along with some biochemical estimations i.e. protein and creatinine levels in liver and kidney were quantified after 7 and 35 days of the treatments. Results: The hematological parameters i.e. Hb%, total count-RBCs, total count –WBCs and protein and creatinine levels in liver and kidney were significantly lowered after 7 and 35 days treatment of cyclophosphamide. The lowering of these values was more prominent in later part of the experiment. Conclusion: Alteration in hematological parameters after cyclophosphamide exposure may impair the functional activities of liver and kidney of male Rattus norvegicus by interfering enzymatic metabolic activities and protein synthesis.

Digestive peritoneum in Wistar rat (Rattus norvegicus) / Peritoneo del aparato digestivo de la rata Wistar (Rattus norvegicus)

La rata de laboratorio (Rattus norvegicus albinus) ha sido usada como modelo para investigaciones médicas, biológicas y moleculares, desde hace mucho tiempo. Sin embargo, no existen descripciones detalladas del peritoneo digestivo de la rata wistar. El objetivo de este trabajo es definir en forma clara y acorde a los principios de la Nómina Anatómica Veterinaria el peritoneo en esta especie de mamífero de laboratorio. Se utilizaron ochenta y ocho ratas (Rattus norvegicus albinus) de entre 250 y 450 g. Fueron disecadas en fresco luego de ser eutanasiadas por sobredosis de tiopental sódico intraperitoneal. Se realizó una incisión paramediana que se extendía desde el cartílago xifoides del esternón hasta el pubis y otra sobre cada arco costal hacia dorsal.

The laboratory rat (Rattus norvegicus albinus) has been used as a model for medical, biological and molecular research, for a long time. It is an interesting fact that there are no detailed descriptions of the gross anatomy of the liver and its ways of fixation. The aim of this study is to define clearly and according to the Nomina Anatomica Veterinaria principles, the liver and its way of fixation in this species of laboratory mammal. Eighty-eight rats (Rattus norvegicus albinus) were used, with a weight between 250 and 450 g. They were dissected in fresh, after been euthanized by an overdose of thiopental sodium intraperitoneal. An incision from the xiphoid cartilage up to the pubic region was made and another on each costal arch toward dorsal.

Uterine leiomyosarcoma in a wild rat (Rattus norvegicus): usefulness of Ki-67 labeling index for diagnosis / 한국실험동물학회지

Uterine smooth muscle tumor is very rare in laboratory rats and, there has been no report in the wild rodents. Among a total of 400 wild rats captured in Gyeonggi, Gangwon, and Chungbuk provinces of Korea in 2007, 2010, and 2011, we found a uterine spindle cell tumor, diagnosed as smooth muscle cell origin based on differential features of histology and immunohistochemistry. Its incidence was very low, like in the laboratory rats, as under 0.5% for female. Considering generally applied histological and cellular criteria, this case was difficult in differential diagnosis between benign and malignant. Ki-67 labeling index was therefore further investigated, and it ranged from 26.4 to 37.6% in the 10 different areas, representing an average of 32.9+/-0.05%. The Ki-67 labeling index of neoplastic cells near the necrotic area was recorded as 83.5%. According to such high Ki-67 labeling index, it was more likely a malignant leiomyosarcoma, assenting to the previous proposal that Ki-67 labeling index is a significant criterion to differentiate between malignant and benign in the smooth muscle tumors.