scholarly journals Effect of formaldehyde inhalation on rabbit nasal mucosa: a light microscopic study—an animal model for inhalational irritants on nasal mucosa

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Wael Mohamed Adel AbdelKafy ◽  
Reham Farouk Zittoon ◽  
Ashraf Saad Abou-Halawa ◽  
Ereny Fekry Youssef Makary ◽  
Mohamed Rifaat Ahmed

Abstract Background Formaldehyde is associated with many adverse health effects and is classified as a human carcinogen. Formaldehyde is highly water-soluble and readily absorbed and metabolized by the respiratory mucosa upon inhalation. The histopathological effects of formaldehyde on the nasal mucosa and olfactory nerves in adult New Zealand white rabbits were studied to validate this animal model of inhalational irritants. Results Compared to control group 1 (exposed to air), groups 2 and 3 (exposed to formaldehyde for 90 min and 210 min, respectively) exhibited disrupted nasal tissue, ulcerated epithelial coverings, markedly dilated blood vessels, and increased numbers of inflammatory cells in the lamina propria. The olfactory neuro-epithelium exhibited a reduction in the number of cilia. Many sustentacular cells lost their microvilli. Olfactory nerves exhibited nerve bundle shrinkage within the perineural sheath, leaving an empty space with evidence of edema within the nerve fibers. Conclusion Formaldehyde inhalation has destructive effects on the nasal mucosa and olfactory nerves in adult New Zealand white rabbits. These results validate the use of this animal model to assess the effects of inhalational irritants on the nasal mucosa.

2019 ◽  
Vol 42 (3) ◽  
pp. 495-500
Author(s):  
Cheng-Hung How ◽  
Chi-Wei Lin ◽  
Yong-Chong Lin ◽  
Tai-Horng Young ◽  
Ke-Cheng Chen ◽  
...  

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2045
Author(s):  
Hamada Elwan ◽  
Mostafa Abdelhakeam ◽  
Sally El-Shafei ◽  
Atef Abd El-Rahman ◽  
Zienhom Ismail ◽  
...  

Animals fed with a high amount of a wide range of antioxidants in their diet are significantly protected against oxidative stress. Powerful antioxidant substances such as vitamin E, vitamin C, and carotenoids are present naturally in red-hot pepper (RHP). This study hypothesized that using RHP may provide protection against oxidative stress and enhance animal physiological responses. Thus, this study aimed to investigate the effect of feeding New Zealand white rabbits with RHP-supplemented diets on their physiological and biochemical responses. New Zealand White rabbits (age = 6 weeks, n = 48) were split equally into three groups (n = 16 in each group). One group was fed a basal diet only (control group), with the other two groups fed a basal diet along with 1 and 2% RHP. Mass spectrometric analysis for the RHP methanolic extract showed some phenolic compounds, such as p-coumaric, sinapinic acids, vanillic, and luteolin, as well as catechin and its isomers. Hepatic antioxidant enzymes (SOD, GSH, GSH-Px, and CAT) were significantly elevated (p < 0.05) by feeding rabbits diets supplemented with 1 or 2% RHP. The addition of RHP significantly enhanced immune-responses; phagocytic activity, chemotaxis, TIg, IgG, IgM, and IgA increased when growing rabbits were fed RHP compared with the control group. In conclusion, dietary supplementation of 1 or 2% RHP may play a role as an enhancer of growth and immune response in growing rabbits.


2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Che Nor Zarida Che Seman ◽  
Zamzuri Zakaria ◽  
Mohamed Azril Mohamed Amin ◽  
Mohd Shukrimi Awang ◽  
Nazri Mohd Yusof ◽  
...  

Introduction: Critical size defects (CSD) in the long bones of New Zealand White rabbit (Oryctolagus cuniculus) have been used for years as an experimental model for investigation of the effectiveness of a new bone substitute materials. There are varieties of protocols available in the literature. This technical note attempts to present an alternative surgical technique of a CSD in the New Zealand white rabbit tibia. Methods: Thirty-nine New Zealand White rabbits were used in this study. A CSD of approximately 4.5 mm (width) X 9.0 mm (length) was surgically drilled at the proximal tibial metaphysis, approximately 1 cm from the knee joint. The surrounding of soft tissue was repositioned and sutured layer by layer with bio absorbable surgical suture. Povidone soaked gauze and bandage were used as a dressing. There is no control group used in this study. Results: This alternative method created good CSD with less bleeding from the muscle observed. No mortality on other surgical complications were observed within 6 weeks, 12 weeks and 24 weeks following surgery. Conclusions: A simple and safe method for performing critical size defect was demonstrated and recommended as an approach for surgery on New Zealand White rabbits.


2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Chengsong Liao ◽  
Yangyang Han ◽  
Zhijing Chen ◽  
Huricha Baigude

Abstract Background A formulation of black cumin (Nigella sativa L.), licorice (Glycyrrhiza glabra L.), anise (Pimpinella anisum L.) and tea (Camellia sinensis (L.) Kuntze) (denoted BLAB tea) is traditionally used to relief allergy reaction including allergic rhinitis. However, little is known about its underlining mechanism of anti-allergic effects. Methods To investigate the anti-allergenic mechanism of BLAB tea, we treated ovalbumin (OVA)-induced allergic rhinitis (AR) model of mice with BLAB tea, and elucidated its possible mechanism of action. Mice in the control group were treated with phosphate-buffered saline only. Subsequently, the infiltration of different inflammatory cells was measured. In addition, histopathological changes in the nasal mucosa, and the levels of allergen-specific cytokines and OVA-specific immunoglobulins were measured. Results The aqueous extract of BLAB significantly alleviated the nasal symptoms and reduced the accumulation of inflammatory cells in the nasal mucosa and nasal lavage fluid of AR model of mice. Conclusion The aqueous extract of BLAB induced the production of Th1 and Treg cytokines and inhibited the release of Th2 cytokines and histamine in nasal mucosa and serum of mice while decreasing the serum levels of OVA-specific IgE, IgG1, and IgG2a. These results suggest the potential of the aqueous extract of BLAB as a treatment option for allergic diseases.


2021 ◽  
Author(s):  
Guanyu Su ◽  
Shaofeng Han ◽  
Bowen Song ◽  
Kai Cao ◽  
Qingfeng Liang

Abstract Objective: To observe the change of the biomechanical properties of rabbit cornea after the intervention by corneal collagen cross linking (CXL) and toluidine blue O combined with red light (TBOR).Methods: The study was carried out in compliance with the ARRIVE guidelines. 20 healthy adult New Zealand white rabbits were randomly divided into two groups. One group was taken with Riboflavin combined with UV light therapy in the right eye of healthy New Zealand white rabbits, and the other group was taken toluidine blue O combined with red light (TBOR) treatment. All left eyes were taken as controls. Parameters, from Pentacam and Corvis ST like K1 (The keratometry readings of the flattest), K2 (The keratometry readings of the steepest), ACD (Anterior chamber depth), Pupil diameter, ACA (Mean angle of the anterior chamber), ACV (Volume of the anterior chamber), bIOP (Biomechanical Intraocular pressure), CT (Corneal thickness, pachymetry), A1 Time(Time from starting until the first applanation), A1 Velocity(Corneal speed during the first applanation moment), A2 Time (Time from starting until the second applanation), A2 Velocity (Corneal speed during the second applanation moment), HC Time(Time from starting until highest concavity is reached), Peak Dist(Distance of the two “peaks” at highest concavity) and HC-Radius(The radius at highest concavity), were examined before and 2 weeks after intervention. The rabbits were sacrificed after anesthesia. Then, their corneas were removed for corneal stretch test.Results: With the examination of Pentacam and Corvis ST, IOP(11.28 ± 11.2mmHg v.s. 6.66 ± 4.02mmHg) and A1 time(7.03 ± 1.27s v.s. 6.55 ± 0.35s) were increased, comparing with those before intervention. From the in vitro corneal stretch test, the tangent modulus of the CXL group was more than 3 times of the Control group, whereas the tangent modulus of the TBOR group was about 0.7 times to that of the Control group.Conclusions: From the rabbit cornea intervention with CXL and TBOR, CXL showed an obvious effect of increasing the hardness of rabbit cornea, while TBOR may did no help to increase the hardness of cornea.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
O Perez-Mendez ◽  
M Luna-Luna ◽  
A Mondragon-Garcia ◽  
A Aranda-Fraustro

Abstract Background Statins may precipitate the onset of type 2 diabetes (T2D) in high-risk patients. In contrast, only the subset of individuals with insulin resistance (IR) and/or diabetes receives cardiovascular benefits with fibrates. The mechanism responsible of such effects may be related with visceral adipose tissue (VAT). In this context, previous observations have suggested that atorvastatin induced an increase of VAT whereas fenofibrate had the opposite effects in rabbits. Purpose To determine the mass, morphology and vascularization of VAT in New Zealand white rabbits that received of atorvastatin or fenofibrate during two months. Methods New Zealand white rabbits (n=6 per group) received by oral gavage during 2 months, 0.33 mg/kg of atorvastatin or 2.6 mg/kg fenofibrate. The control group received 0.5 mL of vehicle. Plasma lipids were monitored. The visceral adipose tissue (VAT) was dissected and quantified. The expression of genes related with vascularization, VEGF-A and TGF-β, FGF2 as well as TNF-α were determined by qPCR in VAT. Histological slices were stained by hematoxilin and eosin to determine the size of adipocytes. The marker of angiogenesis, PECAM-1, was determined by immunohistochemistry. Results As expected, the cholesterol from atorvastatin was lower after treatment while triglycerides decreased in fenofibrate group. The mass of VAT from fenofibrate group was 46% lower compared with the controls meanwhile atorvastatin was associated with a larger diameter of adipocytes (+65%) than that of the control and fenofibrate groups. FGF2 gene expression was lower in fenofibrate than in control group (−54%). By contrast, VEGF-A gene expression in fenofibrate-treated rabbits was 110% higher than in control group. TGF-β and TNF-α remained comparable among groups. In agreement with the gene expression, the marker of angiogenesis PECAM-1 was slightly but significantly higher (+10%) in rabbits treated with fenofibrate than in controls, as determined by immunohistochemistry. Conclusion Fenofibrate enhanced the VEGF-A gene expression, PCAM-1 in VAT whereas decreased its total mass. In contrast, atorvastatin increased the adipocyte size without any effect on vascularization markers. These results suggest that fenofibrate is associated with a favorable remodeling of VAT, in contrast with atorvastatin, which induced a non-favorable remodeling of VAT. These results may be related with the cardiovascular benefits of fenofibrate and the increased risk of T2D in high-risk subjects induced by atorvastatin.


2010 ◽  
Vol 88 (11) ◽  
pp. 1054-1060 ◽  
Author(s):  
Yong-Sheng Yu ◽  
He-Hui Xie ◽  
Ling Li ◽  
Shu-Wei Song ◽  
Ping Han ◽  
...  

The present study was designed to test the hypothesis that a small dose of ketanserin, which enhances baroreflex activity, prevents the early lesions of atherosclerosis. In experiment 1, baroreflex sensitivity (BRS) was measured in 31 spontaneously hypertensive rats (SHRs) in a conscious state using a computerized blood pressure monitoring system. Four weeks later, the rats were administered vitamin D3 and fed a high-cholesterol diet for 8 weeks to induce atherosclerosis. Then their hearts and aortae were removed for pathological examination. A negative correlation was found between BRS and the scores of coronary (r = –0.460, P < 0.01) and aortic atherosclerosis (r = –0.448, P < 0.05) in SHR. In experiment 2, SHRs were divided into 3 groups (n = 10 in each group) and received a dose of ketanserin of 0.3, 1.0, and 3.0 mg/kg (i.g.), respectively. At the smallest dose (0.3 mg/kg), ketanserin did not lower blood pressure but enhanced BRS. In experiment 3, SHRs were administered vitamin D3, fed a high-cholesterol diet, and simultaneously treated with low-dose ketanserin. The atherosclerosis scores of the treatment group were significantly lower than those of the control group (coronary score: 0.90 ± 0.14 vs. 1.76 ± 0.27, P < 0.05; aortic scores: 1.00 ± 0.39 vs. 2.18 ± 0.41, P < 0.05). In experiment 4, male New Zealand White rabbits were fed a high-cholesterol diet and treated with low-dose ketanserin at the same time. The atherosclerosis scores of the treatment group were significantly lower than those of the control group (aortic scores: 0.26 ± 0.20 vs. 0.60 ± 0.31, P < 0.05). In conclusion, the present study demonstrated, for the first time, that low-dose ketanserin prevented the development of atherosclerosis independent of its blood pressure lowering action in SHRs and New Zealand White rabbits at least in part via enhancement of arterial baroreflex function.


1991 ◽  
Vol 105 (6) ◽  
pp. 826-831 ◽  
Author(s):  
David A. Foggia ◽  
Steven D. Gray ◽  
Kevin M. Kelly

Five-week-old New Zealand white rabbits were divided into three groups: control, anterior-posterior cricoid split with stent, and cricoid quartersection (anterior-posterior-lateral cricoid split) with stent. The stents were removed 2 weeks after placement. The rabbits were allowed to grow for six months, at which time they were killed and the larynges were studied. Average, minimal, and maximal subglottal cross-sectional areas were calculated for each animal and adjusted for weight. The cricoid quarter section group had significantly greater average, minimal, and maximal subglottal cross-sectional areas compared to controls and significantly greater minimal and maximal cross-sectional areas compared to the anterior-posterior cricoid split group. The anterior-posterior cricoid split group and the control group did not significantly differ with respect to any of the three parameters. The results indicate that anterior-posterior cricoid split and cricoid quartersection do not adversely affect subglottic growth. Cricoid quartersectioning was superior to the anterior-posterior cricoid split in its ability to expand subglottic airway dimension.


2020 ◽  
Vol 40 (1) ◽  
Author(s):  
Tong Zhang ◽  
Zhiming Shen ◽  
Jie Zheng ◽  
Rui Jiang

Abstract Hypertrophic scars (HTSs) are common and cause functional and psychological morbidity. UVA1 (340–400 nm) phototherapy has been previously shown to be effective in the treatment of localized scleroderma, systemic sclerosis, and POEMS syndrome with minimal side effects, all of which are presented as collagen fibrils hyperplasia that is common with scarring in skin histology. In the present study, we aimed to investigate the impact of UVA1 on the protein expression of TGF-β signal pathway and myofibroblasts in a rabbit model of cutaneous scarring. Full-thickness skin wounds (2 cm × 5 cm in diameter) were made in New Zealand white rabbits to establish the hypertrophic scarring model. New Zealand white rabbits were divided into two treatment groups (n=30 wounds per group with an equal number of controls): medium-dose of UVA1 phototherapy group: 60 J/cm2; high-dose of UVA1 phototherapy group: 110 J/cm2. Left ears were used for treatment and the right ones were used for control. Treatment was administered five times weekly for 6 weeks. Treated and untreated control wounds were harvested at various time points and examined by histologic examination, immunohistochemical assessment, and ultrastructural evaluation. The results showed that UVA1 phototherapy caused a significant reduction in dermal thickness by histological features, whereas the scar index was descended significantly in both medium- and high-dose UVA1 groups compared with the control group. Examination of immunohistochemistry also revealed a marked suppression of tissue growth factor-β (TGF-β) (both medium- and high-dose), α smooth muscle actin (α-SMA) (only high-dose), and tissue inhibitor of metalloproteinase 1 (TIMP-1) (only high-dose), and apparent increase in matrix metalloproteinases (MMP-1) (both medium- and high-dose) compared with the control. The ultrastructural evaluation showed the collagen fibers’ diameter had shrunk, and that fibroblastic cytoplasm was not affluent and in a quiescent stage. These findings of the present study suggested that administration of UVA1 irradiation is effective to improve the experimental HTS model and raises a possibility of the therapeutic approach of UVA1 in the scar. Although not directly examined in the present study, MMP inhibition is hypothesized to be responsible for this effect. However, early UVA1 treatment could not prevent the formation of scar model.


2017 ◽  
Vol 57 (8) ◽  
pp. 1759 ◽  
Author(s):  
Hesham Mohammed ◽  
Mohammed Nasr

The present study investigated the effect of gnawing sticks as environmental enhancers on the performance, carcass traits and behaviour of individually housed growing rabbits. Two batches of weaned New Zealand White (NZW) rabbits were used, each consisting of 135 animals. Rabbits were homogeneously classified into the following three groups, each consisting of 45 rabbits: rabbits housed individually in cages without enrichment (control), rabbits housed individually in cages enriched with wooden sticks from apple tree and rabbits housed individually in cages enriched with wooden sticks from willow tree. Rabbits reared in enriched cages with apple or willow sticks showed a significantly (P &lt; 0.0001) better performance (live bodyweight at slaughter 2526 and 2591 g, total weight gain 1620 and 1683 g, average daily gain 21.04 and 21.87 g and daily feed intake 78.57 and 74.89 g respectively), and had a higher carcass weight (1648.39 and 1750.26 g respectively, P &lt; 0.0001) than did the control group. Rabbits in apple-stick group had a higher daily feed intake (78.57 g, P &lt; 0.0001) and lower carcass weight (1648.39 g, P &lt; 0.0001) than did those in the willow-stick group. The cortisol concentration was significantly (P &lt; 0.0001) lower in apple and willow groups (9.44 ± 0.02 and 9.35 ± 0.02 nmol/L respectively) than in the control group (17.24 ± 0.03 nmol/L). Moreover, cage enrichment with apple or willow sticks improved the duration of feeding (7.08 and 7.39 min/3 h respectively, P &lt; 0.0001) and drinking (2.54 and 2.67 min/3 h respectively, P &lt; 0.0001) time, and reduced abnormal behaviour (biting the bars of the cage 0.24 and 0.34 min/3 h respectively, P = 0.001) when compared with the control group. Overall, the current results indicated that cage enrichment (with wooden sticks from apple or willow trees for gnawing) increased the final bodyweight and some carcass traits, reduced abnormal behaviour and potentially improved rabbit welfare during intensive rabbit breeding.


Sign in / Sign up

Export Citation Format

Share Document