Vertebral formula and congenital abnormalities of the vertebral column in rabbits.

The aim of this retrospective study of 330 rabbits (164 males, 166 females) was to determine different vertebral formulas and prevalence of congenital vertebral anomalies in rabbits from radiographs of the cervical (C), thoracic (Th), lumbar (L) and sacral (S) segments of the vertebral column. The number of vertebrae in each segment of vertebral column, position of anticlinal vertebra and localisation and type of congenital abnormalities were recorded. In 280/330 rabbits (84.8%) with normal vertebral morphology, seven vertebral formulas were identified: C7/Th12/L7/S4 (252/330, 76.4%), C7/Th12/L6/S4 (11/330, 3.3%), C7/Th13/L7/S4 (8/330, 2.4%), C7/Th12/L7/S5 (4/330, 1.2%), C7/Th12/L8/S4 (3/330, 0.9%), C7/Th12/L7/S6 (1/330, 0.3%) and C7/Th11/L7/S4 (1/330, 0.3%). The anticlinal vertebra was identified as Th10 in 56.4% of rabbits and Th11 in 42.4% of rabbits. Congenital spinal abnormalities were identified in 50/330 (15.2%) rabbits, predominantly as a single pathology (n=44). Transitional vertebrae represented the most common abnormalities (n=41 rabbits) in the thoracolumbar (n=35) and lumbosacral segments (n=6). Five variants of thoracolumbar transitional vertebrae were identified. Cervical butterfly vertebrae were detected in three rabbits. One rabbit exhibited three congenital vertebral anomalies: cervical block vertebra, thoracic hemivertebra and thoracolumbar transitional vertebra. Five rabbits exhibited congenital vertebral abnormalities with concurrent malalignment, specifically cervical kyphosis/short vertebra (n=1), thoracic lordoscoliosis/thoracolumbar transitional vertebrae (n=1), thoracic kyphoscoliosis/wedge vertebrae (n=2) and thoracolumbar lordoscoliosis/thoracolumbar transitional vertebrae/lumbosacral transitional vertebrae (n=1). These findings suggest that vertebral columns in rabbits display a wide range of morphologies, with occasional congenital malformations.

Adverse fetal outcomes in pregnant rabbits experimentally infected with rabbit hepatitis E virus.

Hepatitis E virus (HEV) causes severe hepatitis in pregnant women, with associated poor fetal outcomes. To study HEV viral pathogenesis, pregnant rabbits were infected with low- and high-dose rabbit HEV at 2 weeks gestation. HEV was identified in the serum, feces, and liver tissue of infected rabbits, and dose-dependent fetal mortality rates ranging from 67% to 80% were observed. The aspartate transaminase (AST)/alanine transaminase ratio was significantly higher (P < 0.01) in high-dose infected rabbits than low-dose infected and negative control rabbits 14 days post infection (dpi). Tumor necrosis factor-α (TNF-α) was significantly higher in low-dose (P < 0.01) and high-dose infected rabbits (P < 0.001) than in negative controls 7 dpi. High-dose HEV-infected rabbits produced significantly more interferon-γ (IFN-γ; P < 0.05) than negative control rabbits at 7 and 14 dpi. High levels of AST, TNF-α, and IFN-γ may substantially influence adverse fetal outcomes in pregnant rabbits infected with high-dose HEV.

Actividad antipirética del producto natural Noni-C en un modelo experimental en conejos / Antipyretic activity of the natural product called Noni C in an experimental rabbit model

INTRODUCCIÓN: en la medicina tradicional de Cuba se usa el fruto de la planta conocida como Noni por su efecto beneficioso sobre la salud. A esta se le atribuyen innumerables propiedades curativas. Sin embargo, no existen estudios preclínicos que demuestren el efecto antipirético y validen su uso. OBJETIVO: evaluar la actividad antipirética del producto natural Noni-C (Morinda Citrifolia Linn) en un modelo experimental en conejos. MÉTODOS: se realizó un ensayo preclínico en el Departamento de Investigaciones Médico Militares del Hospital militar "Dr. Luis Díaz Soto". Se utilizaron 30 conejos de la línea nueva Zelanda, sexo masculino y peso corporal entre 2,2 ­ 2,5 kg, distribuidos al azar en 5 grupos. Al grupo I se le inoculó Cloruro de Sodio 0,9 %, mientras que el grupo II fue tratado con ibuprofeno (100 mg/Kg). A los grupos III, IV y V se les administró Noni-C en dosis de 200, 400 y 800 mg/Kg respectivamente. Se midió temperatura basal rectal y los tiempos de una, dos, cuatro y seis horas postratamiento. Como inductor de la fiebre se utilizó una solución al 20 % de levadura desecada en cloruro de sodio al 0,9 %. El nivel de significación se fijó en p<0,05. RESULTADOS: se observó una disminución significativa de la temperatura corporal (p=0,00) a las dosis de 400 y 800 mg/Kgde N oni-C (38,5 ºC y 38,2 ºC) respectivamente, similar al del fármaco de referencia ibuprofeno, 38,5 ºC posterior a las 2 horas de haber suministrado la sustancia en estudio. Se pudo concluir que el producto natural Noni-C mostró actividad antipirética a las dosis de 400 y 800 mg/Kg administrado por vía oral.

INTRODUCTION: in the Cuban traditional folk medicine, the fruit of a plant called Noni is used because of its beneficial effects on health and attributable curative qualities. However, there are no preclinical research studies that prove the antipyretic effect of Noni and validate its use in this field. OBJECTIVE: to evaluate the antipyretic activity of the natural product Noni C (Morinda Citrifolia Linn) in an experimental rabbit model. METHODS: a preclinical assay was performed in the military medical research department of ¨Dr Luis Diaz Soto¨ military hospital. Thirty male New Zealand-line rabbits, weighed 2.2-2.5 kg and randomly distributed into 5 groups were used in the study. The first group was inoculated 0.9% sodium chloride; Group II was treated with Ibuprofen (100 mg/kg) whereas groups III, IV and V received Noni C at a dose of 200, 400 and 800 mg/kg, respectively. The basal rectal temperatures were measured at one, two, four and six hours after the treatment. The fever inducer was 0.9% sodium chloride-dried 20% yeast solution. The level of significance was set at p<0.05. RESULTS: body temperature significantly lowered with the 400 and 800 mg doses (38.5 and 38.2) respectively, similar to the figure of the reference drug Ibuprofen after two hours of administration of the substance under study. CONCLUSIONS: it was concluded that the natural product Noni-C showed its antipyretic action with the 400 and 800 mg/kg orally administered doses.

Unilateral persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous in a rabbit.

A 3-month wild rabbit was presented for examination of ocular opacities in the left eye. A complete bilateral ocular examination including slit-lamp examination, indirect ophthalmoscopy, tonometry, and ultrasound biomicroscopy was performed. Biomicroscopy of the lens of the left eye showed a retrolental fibrovascular membrane causing leukocoria. The opacity prevented biomicroscopy of the vitreous and funduscopy OS. No other disorder was present in either eye. Ultrasound examination did not show any difference between the right and left eye. Histopathological examination showed a 50-µm thick, preretinal, retrolental, nonpigmented, fibrovascular tissue. Posterior synechiae were present, but no other lesion of the posterior segment was found in this eye. These ocular abnormalities are consistent with a persistent hyperplastic tunica vasculosa lentis and persistent hyperplastic primary vitreous (PHTVL/PHPV), similar to those described in other species.

Multiple complex congenital malformations in a rabbit kit (Oryctolagus cuniculi).

Congenital malformations may occur during early embryogenesis in cases of genetic abnormalities or various environmental factors. Affected subjects most often have only one or 2 abnormalities; subjects rarely have several unrelated congenital defects. Here we describe a case of a stillborn New Zealand white rabbit with multiple complex congenital malformations, including synophthalmia, holoprosencephaly, gastroschisis, and a supernumerary hindlimb, among other anomalies. There was no historical exposure to teratogens or other known environmental causes. Although not confirmed, this case was most likely a rare spontaneous genetic event.

Mandible measurements and dental midline deviation after alveolar nerve transection in growing rabbits / Medidas mandibulares y desviación de la línea mediana dental luego de la transección del nervio alveolar inferior en conejos en crecimiento

The relationship between sensitive innervation and normal mandibular bone development has been described in the literature. Therefore, neural damage is a potential cause of osseous deformities, particularly in growing subjects. The aim of this project is to present the mandible measurements obtained after the transection of the inferior alveolar nerve of growing rabbits. A specific surgical protocol was designed to carry out the unilateral nerve transection by avoiding musculoskeletal injuries. Twenty New Zealand White rabbits one week post-weaning were used, 12 as an experimental group and 8 as a control group (Sham operated). The animals were sacrificed 90 days postoperatory, and the mandibles carefully dissected. Dental midline deviation data were obtained under anesthesia, previous to sacrifice. All measurements were obtained with a micron digital caliper. For this study, only anterior-posterior measurements were obtained from five points specifically determined on the rabbit mandible. Each measurement was made three times by the same examiner and the average value was considered. Regarding the anterior-posterior measurements, the molar and incisive regions of the denervated hemimandible were significantly shorter than the corresponding regions in the non-denervated side. The control group did not show these differences. A dental midline deviation was observed, but not always directed on the operated side. However, the deviation values were greater when oriented to the denervated side. These changes did not cause evident deformity or dysfunction in the masticatory system of the animals. They were fed normally and their weight was considered within normal parameters while growing. Despite the biological relationship between sensory inervation and bone morphology, the effect of sensory denervation in early stages of bone growth appears to generate only small alterations on the mandible morphology. However, these alterations do not lead to functional proble...

Se ha descrito una importante relación entre la inervación sensitiva y aspectos biológicos mandibulares. Consecuentemente, el daño a la estructura nerviosa es una causa potencial de alteraciones en el desarrollo mandibular, sobre todo en etapas de crecimiento. El objetivo de este trabajo es presentar mediciones mandibulares realizadas posterior a una lesión del nervio sensitivo en una etapa temprana de crecimiento. Se diseñó un protocolo quirúrgico para realizar la transección del nervio alveolar inferior sin lesionar estructuras musculoesqueléticas. Veinte conejos Neo zelandeses blancos fueron utilizados, una semana post-destete, 12 como grupo experimental y 8 como grupo control. Los animales fueron sacrificados 90 días después y las mandíbulas cuidadosamente disecadas. La información de la desviación de la línea media se obtuvo bajo anestesia, previo al sacrificio. Todas las mediciones se obtuvieron con un calibrador digital. Las medidas antero-posteriores se obtuvieron a partir de cinco puntos específicamente determinados en la mandíbula del conejo. En cuanto a las medidas antero-posteriores, las región molar e incisiva de las hemimandíbulas denervadas fueron significativamente menores que la correspondiente del lado no denervado. El grupo control no mostró esta diferencia. La línea media dental siempre se observó desviada, pero no siempre hacia el lado intervenido. Sin embargo, la media de desviación fue mayor cuando ésta se orientó hacia el lado denervado. Estos cambios no causaron deformidad evidente o disfunción en el sistema masticatorio de los animales, los cuales se alimentaron normalmente. El peso de los mismos fue considerado dentro de los parámetros normales. A pesar de la relación biológica entre la inervación sensitiva y la morfología del hueso, el efecto de la denervación sensitiva en las primeras etapas de crecimiento parece generar sólo pequeñas alteraciones en la morfología mandibular. Sin embargo, éstas no conducen a problemas funcionales...

Effects of thalidomide on developmental, peri- and postnatal function in female New Zealand whith rabbits and offspring

The present study determined effects of thalidomide on three successive generations of New Zeland Whith rabbits after oral dosing to FO maternal rabbits during the later third of gestation (post major organogenesis) and lactation. On hundred and twenty four time-mated FO rabbits (31/dose) were gaveged with 0,030,150, or 500mg/kg thalidomide from gestation day 18 (DG 18) to lactation day 28 (DP or day postpartum 28) for approximately 42 days. At 6 months, 12 F1 females were randomly paired witthin each dose group and mated. Reproductive evaluation and/or gross necropsy of the thoracic, abodominal, and pelvic viscera was perfomed on day 29 postpartum (DP 29) for FO rabbits, on DP49 for F1 pups not selected for continued evaluation, sfter completion of mating for F1 rabbits, and on DG 29 for F1 rabbits on continued evaluation of F2 litter. There was no thalidomide-related mortality in FO and F1 rabbits. One FO doe at 30 and 150 mg/kg and 2 at 500 mg/kg aborted. Maternal FO rabbits had reductions in feed consumption but no body weight gain during the gestation and lactation periods for 150 and 500 mg/kg. The numbers of does with stillborn and all pups dyving from DP 1-4 was increased at 150 and 500 mg/kg. Mean number of liverborn (litter size) and percentage of live pups were decreased at 500 mg/kg. A significantly increased number of pups died at 150 and 500 mg/kg, resulting in a reduced viability index and decreased litter size. There were some F1 male and female bodyweight reductions at 150 and 500 mg/kg postweaning with no changein feed consumption. F1 Caesarean-sectioning and litter observations were normal. Fertility of F1 offspring was not affected by maternal doses of thalidomide, but the pregnancy index may have been reduced by the 500 mg/kg maternal thalidomide dose. There was an apparent dose-related increased in splayed limbs in F1 pups. Splaving has been reported in New Zealand Whith rabbits and may be a recessive trait. The splay could be caused by the nerve and muscle fiber degeneration and skeletal muscle atrophy observed in some pups. It could also be due to the decreased in litter size, resulting in fewer pups per litter for nursing, leading to rapid weight gain and a failure of the pups to support this weight. No F@ fetal gross external alterations were observed.

Efecto de la aplicación tópica de la Mitomicina C sobre el endotelio corneal de conejos albinos / Effect of external application of the Mitomicina C on the corneal endothelium of albino rabbits

Se desea investigar el efecto de la Mitomicina C en los tejidos subconjuntivales. Se utilizaron endotelio corneal de conejos albinos divididos en dos grupos. El grupo A reveló que la mitomicina C en gotas al 0,04 por ciento por 5 días BID, genera una alteración estadísticamente significativa en la hexagonalidad celular, densidad y en la morfología celular. En el grupo B, sometido a concentraciones de 0,04 por ciento intraoperatorio, con lavado después de tres minutos, se observaron cambios en la hexagonalidad celular estadísticamente significativos

Sutural bone frequency in synostotic rabbit crania.

This study tests the hypothesis that crania with synostosed sutures will have a significantly higher incidence of calvarial sutural bones than normal crania. Sutural bones were counted in seven calvarial sutures and compared among four groups of adult New Zealand white rabbit skulls: normal in-colony (NI) controls (N = 14), normal out-colony (NO) controls (N = 12), skulls with familial delayed onset (DO) coronal synostosis (N = 25), and skulls with experimentally immobilized coronal sutures (EI) (N = 20). Comparisons among groups were made with a Kruskal-Wallis one-way ANOVA and between groups with a Mann-Whitney U-test, using a Bonferroni correction for multiple comparisons. Significant differences (P < 0.05) were noted only in the coronal and sagittal sutures, with EI crania having the greatest number of coronal sutural bones; between group differences were undetectable for sagittal sutural bones. A post hoc two-sample binomial test for equal proportions showed that the distribution of coronal sutural bones among individuals across groups was even, while the distribution of sagittal sutural bones was significantly higher in EI crania. These results suggest that altered sutural forces of the calvaria contribute to an increased occurrence of sutural bones. However, the influence of inheritance on increased occurrence of sutural bones cannot be discounted, as reflected in the equivalent number of individuals across groups that possessed coronal sutural bones.

Two decades of control Himalayan rabbit reproductive parameters and spontaneous abnormalities in Japan.

The Himalayan rabbit, Chbb:HM, has been bred in a closed colony at our institute from 1971 through 1991. Cumulative reproductive and teratological data of 514 litters from control does in embryotoxicological Segment II studies carried out over this period are herein reported. If compared with other strains of rabbit, the observed pregnancy rate of 92.2% was high, and spontaneous mortality or abortions were rare. However, the average numbers of corpora lutea, implantation sites and viable fetuses per doe were somewhat low. A total of 30 malformations and 130 variations occurred among 2883 viable fetuses.

Development of a strain of rabbits with congenital simple nonsyndromic coronal suture synostosis. Part I: Breeding demographics, inheritance pattern, and craniofacial anomalies.

The lack of an animal model of congenital coronal suture (CS) synostosis has prompted the widespread use of an experimental rabbit model using adhesive immobilization of the CS. Such postnatal models have helped make significant scientific contributions but may still not fully represent all aspects of the human congenital condition. In the March 1993 issue of The Cleft Palate-Craniofacial Journal we reported a female rabbit born in our laboratory with complete bilateral CS synostosis. This follow-up study presents our attempts to breed this animal and establish a strain of craniosynostotic rabbits. To date, we have accomplished 10 back- and intercrosses with these animals and have produced a total of 71 live offspring; 10 animals exhibited complete nonsyndromic unilateral (plagiocephalic) or bilateral (brachycephalic) CS synostotic deformities at birth, and 19 animals exhibited partial CS synostosis that showed more than 75% growth retardation across the CS (well below the 95% confidence interval for normals). Results revealed that gestational time and litter size averages were consistent with those reported for the strain, although the average litter size decreased with increased inbreeding. By 1.5 weeks of age the completely synostosed animals already exhibited brachycephalic cranial vaults and midfacial hypoplasia compared to unaffected siblings. Initial pedigree analysis suggested an autosomal dominant inheritance pattern with incomplete penetrance and variable expressivity. The development of such a congenital rabbit model may prove useful in helping to understand the etiopathogenesis of this condition in human populations.

Congenital bilateral coronal suture synostosis in a rabbit and craniofacial growth comparisons with experimental models.

Experimental rabbit models of postnatal coronal suture (CS) synostosis have helped make significant contributions towards the understanding and surgical management of human congenital craniosynostosis. The present study compares craniofacial growth patterns in animals with experimental CS immobilization and in a rabbit born in our laboratory with congenital CS synostosis. The study sample consisted of 10 sham controls, 14 experimental animals with bilateral CS immobilization, and one animal with congenital, bilateral CS synostosis. At 1.5 weeks of age, all animals had amalgam markers placed on either side of the frontonasal, coronal, and anterior lambdoid sutures. At this time, the experimental animals had bilateral CS immobilization using methyl-methacrylate. Serial lateral head x-rays were taken at 1.5, 6, 12, and 18 weeks of age. Results revealed that by 1.5 weeks of age the congenital animal already exhibited changes in the cranial vault, cranial base, midface, and orthocephalic cranial base angles compared to controls. By 6 weeks of age, animals with experimental immobilization showed compensatory growth patterns similar to the congenital animal, particularly at the calvarial sutures and upper midface. This pattern continued through 18 weeks. Results showed that experimental, postnatal CS immobilization produced similar craniofacial growth patterns to those observed for our single congenital animal, but to a lesser degree, and therefore validates, in part, findings from experimental rabbit models of synostosis.

"Nude rabbit" with aplasia of B-lymphoid structures.

An original observation of the randombred nude rabbit with aplasia of B-lymphoid structures (absence of the follicles in lymph nodes and spleen, no Peyer's plaques). The thymus gland and the T-dependent structures in the spleen and lymph nodes were-on the contrary-well preserved. The nude skin of this genetic rabbit mutant contained large numbers of hair follicles showing almost intrafollicular retention of hairs with their subsequent dysplasia at the subepidermal and ostiopilar level.

[Tibial aplasia and agenesis in a rabbit (case report)]. / Tibiale Aplasie und Agenesie bei einem Kaninchen (Fallbericht).

The occurrence of a tibial aplasia (left side) and agenesia (right side) in a rabbit (aged 4 weeks) is reported. Apart from extreme distorsions of the fibular bones, there were no other skeletal malformations.

A case of combined hermaphroditism and autofertilisation in a domestic rabbit.

A true hermaphrodite rabbit served several females and sired more than 250 young of both sexes. In the next breeding season the rabbit, which was housed in isolation, became pregnant and delivered seven healthy young of both sexes. It was kept in isolation and when autopsied was again pregnant and demonstrated two functional ovaries and two infertile testes. A chromosome preparation revealed a diploid number of autosomes and two sex chromosomes of uncertain configuration.