Corrosion casting, a known technique for the study and teaching of vascular and duct structure in anatomy / Inyección corrosión, una técnica conocida para el estudio y enseñanza de ductos y estructuras vasculares en anatomía

Teaching and learning anatomy, as a process, has changed. Fresh cadavers were once used as a tool for the student to approach the human body in order to overcome theoretical knowledge and gain applied expertise. Today, techniques such as corrosion casting are known to be a more effective way of achieving optimal results with the students. This paper examines a method to apply this technique to an organ using different polymers. The concentrations for acrylic, epoxy resin, polyester resin, and room temperature vulcanization (RTV) silicone are described, as well as the corresponding diameter of the duct to be injected with each one. A variety of specimens obtained using this technique, their qualities and characteristics are presented. The results of using these procedures while involving the students, showed increased sense of responsibility, dedication and awareness, which led them to take the class more seriously and enjoy the process of learning. Additionally, the specimens left by the students will help future classes reduce the number of specimens needed.

El proceso de aprendizaje y enseñanza en anatomía ha cambiado recientemente, el cadáver fue la primera herramienta que permitía al estudiante una aproximación practica al cuerpo humano, facilitando que este se sobrepusiera al conocimiento teórico adquirido en el aula, y desarrollara experticia aplicada. Hoy en día, técnicas como la inyección corrosión son conocidas por lograr mejores resultados con los estudiantes. Este trabajo presenta un método para aplicar esta técnica a un órgano, mediante el uso de diferentes polímeros. Las concentraciones adecuadas de acrílico, resina epoxica, resina poliéster, y silicona RTV (room temperature vulcanization) son descritas, así como el diámetro sugerido para el uso de cada polímero. Se presenta una variedad de especímenes obtenidos mediante esta técnica, así como sus cualidades y características. Al integrar a los estudiantes en el proceso de creación de los especímenes, estos demuestran mayor sentido de responsabilidad, dedicación y autoconciencia, generando mayor compromiso, y entusiasmo con la clase y el proceso de aprendizaje. Adicionalmente, los especímenes producidos por ellos, serán de gran utilidad para clases a futuro.

Morphologic differences of vascular buds in vertebral cartilage endplate in age-specific rabbits / 中华骨科杂志

Objective To observe the morphologic changes of of vascular buds in vertebral cartilage endplate in age-specific rabbits and also to investigate the correlation between the changes of vascular buds and interverbral disc degeneration. Methods There were 15 New Zealand white rabbits in our study,which include three groups, 2-week-old rabbits, 1-year-old rabbits and 3-year-old rabbits, and each groups had five rabbits. The X-ray radiograph, histology and scanning electron microscope were used to observe the changes of vertebral cartilage endplate. According to Miyamoto standard, the interverbral disc was graded 1-5, and scored 1-5 respectively. Results The changes of micro-vascular structure of vertebral cartilage endplate were observed during aging. Under the scanning electron microscope, the vascular structure degenerated gradually, and disappeared in the end. The blood vessels in the central region of the vertebral cartilage endplate reduced more obviously than those in periphery region. The severe degeneration was found in vertebral endplate, compared with intervertebral disc. The changes of vascular buds in rabbits vertebral cartilage endplate had positive correlation with the vertebral endplate calcification and the interbertebral disc degeneration. Conclusion Changes of vascular buds in vertebral endplate may accelerate intervertebral disc degeneration.

Control study of the ultrasonography with the placental vascular casts of the acardiac twins sequence / 中华超声影像学杂志

Objective To investigate the relationship between the ultrasonography diagnosis in prenatal and the postnatal placental vascular casts of the twins reversed arterial perfusion(TRAP) sequence. Methods Six cases of TRAP sequence underwent the two-dimensional and color Doppler ultrasonography, and performed placental vascular casts after termination of pregnance. Results According to the anatomical features and ultrasonography, there were 3 cases of acardius acephalus( IV) ,2 cases of acardius anceps( II ) , and 1 case of acardius acormus( I ). In all 6 cases,there were arterio-arterial and veno-venous anastomoses at the level of the chorionic plate between the normal co-twin and the acardiac twin,these anastmosis vessels were superficial and large calibre, and the distances of the placental insertions of the umbilical cords were different,4 cases <0. 5 cm, 2 cases were 4-5 cm. In 4 cases, the vessels entered and went out of the acardiac twin were just one large umbilical artery and one large umbilical vein. In 2 cases, the umbilical artery and umbilical vein had many vascular branches in the placenta. Out of 6 cases of the pump twin, 4 cases died,and 2 cases survived. Conclusions Ultrasonography was consistent with the placental vascular casts,the contrast observing gives us new information for the further research of the special type of the vascular anastmosis and prognosis of the TRAP sequence.

Dominância coronariana em corações humanos em moldes por corrosão / Coronary dominance patterns in the human heart investigated by corrosion casting

Objetivo: Esse trabalho tem como objetivo analisar os padrões de dominância circulatória de corações humanos, o número de ramos que a artéria coronária direita fornece ao ventrículo esquerdo, o número de ramos que a artéria coronária esquerda fornece ao direito e a presença de anastomoses intercoronarianas, com sua localização e frequência. Métodos: Foram produzidos 25 moldes de corações submetidos à instilação de acrílico colorido e posterior corrosão com ácido clorídrico, no Laboratório de Cirurgia Experimental da FURB. Peças com lesões e cicatrizes não foram usadas. Resultados: Os corações pertenciam a indivíduos de ambos os sexos, sendo 17 (68 por cento) de indivíduos do sexo masculino, com idade média de 40,2 anos (15 a 70 anos). A dominância direita ocorreu em 18 (72 por cento) peças, com 1, 2, 3 e 4 ramos em 2, 14, 2 e 1 moldes, respectivamente; a dominância esquerda foi observada em 5 (20 por cento) casos, com 1 ramo em 4 moldes e 2 em 1 molde; e a dominância balanceada foi verificada em 2 (8 por cento) moldes. Houve diferença significativa entre a dominância direita e esquerda (α > 5 por cento), direita e balanceada (α > 5 por cento) e sem significância entre esquerda e balanceada (α < 5 por cento). Conclusão: A forma mais comum de circulação coronariana é a de dominância direita, com média de 2,16 ramos ao ventrículo esquerdo; enquanto nos casos de dominância esquerda, fornece em média 1,2 ramos. Não se observaram anastomoses intercoronarianas.

Objectives: The aim of this work was to analyze the dominance patterns of the circulation of the human heart, the number of branches from the right coronary artery to the left ventricle, the number of branches from the left coronary artery to the right ventricle and the frequency and location of intercoronary anastomoses. Methods: Casts were made of 25 hearts by the injection of colored acrylic resin and subsequent corrosion using hydrochloric acid at the experimental surgery laboratory of Furb. Specimens with lesions or scars were discarded. Results: The hearts, from both men (17 - 68 percent) and women (8 - 32 percent), had a mean age of 40.2 (15 to 70) years-old. Right dominance occurred in 18 (72 percent) subjects, with 1, 2, 3 and 4 branches leading to the left ventricle in 2, 14, 2 and 2 casts, respectively. Left dominance occurred in 5 (20 percent) with 1 branch leading to the right ventricle in 4 molds and 2 in one. Balanced circulation was observed in two molds (8 percent). There were significant differences between right and left dominance (α > 5 percent) and between right dominance and balanced circulation (α > 5 percent), however the same was not true between left dominance and balanced circulation (α < 5 percent). Conclusion: The most common form of coronary circulation is right dominance with an average of 2.16 branches leading to the left ventricle: when dominance is left, the average is 1.2 branches. No intercoronary anastomoses were observed.

Análise da segmentação venosa hepática através de moldes de resina / Hepatic venous segmentation analysis by resin cast

OBJETIVO: Aferir a independência da segmentação da drenagem venosa hepática, bem como a relação entre seus segmentos. MÉTODO: Foram utilizados trinta fígados humanos, analisados cuidadosamente para exclusão de possíveis rompimentos extra e intra-parenquimatosos. Foi injetada uma resina sintética (Resapol T-208) nas veias hepáticas direita, média e esquerda isoladamente, com diferentes cores, para identificação dos segmentos, utilizando-se a técnica de injeção-corrosão. Após a obtenção dos moldes, foi realizada a pesagem e a planimetria destes, em conjunto e separadamente. RESULTADOS: Foi observado que todos os moldes hepáticos apresentaram independência entre seus segmentos e que o segmento direito foi o maior (p=0,005). Ao correlacionar o peso do fígado com a proporção entre os segmentos, obteve-se um coeficiente de correlação de 0,023. CONCLUSÕES: Os segmentos das veias hepáticas são independentes entre si, ocorrendo preponderância do segmento venoso direito sobre os demais e o aumento do peso do fígado sem patologia corresponde a um aumento proporcional entre os seus segmentos.

OBJECTIVE: To establish the independence of segmentation of the hepatic venous drainage and the relationship among its segments. METHODS: Thirty livers were carefully analyzed in order to exclude any intraparenchymatous injury. A synthetic resin (Resapol T-208) was injected into each one of the hepatic veins (right, middle and left), in different colors, to identify each segment, using the injection-corrosion technique. In each liver the obtained casts were weighed and submitted to planimetry, separately and altogether. RESULTS: The fact that all the livers' casts have independent segments was noticed, and the right segment was the largest one (p=0,005). A coefficient of 0,023 was obtained correlating the weight of the liver with the proportion of its segments. CONCLUSIONS: Hepatic venous segments are independent and the right venous segment is predominant. Furthermore, the weight of a healthy liver is proportional to the size of its segments.

Angiogenesis in Distraction Osteogenesis / 대한정형외과학회잡지

PURPOSE: Distraction osteogenesis is now a standard method for bone lengthening. However, little is known about the exact mechanism of new bone formation. This study was undertaken to investigate the temporal and spatial changes of angiogenesis during the periods of distraction osteogenesis; the three-dimensional microarchitecture of newly formed vessels and their origin; and the role of angiogenesis with reference to mineralization. MATERIALS AND METHODS: Sprague-Dawley rat's tibia was osteotomized subperiosteally and was distracted at a rate of 0.5 mm per day for two weeks after one week of latency period. Vascular corrosion casting using Mercox was done on the hindlimbs before osteotomy, and at the 1st, 2nd, 3rd, 4th, and 6th weeks postoperatively. Replicated microvascular structures and their distribution patterns at the distraction site and adjacent parent bone were observed temporally and spatially under scanning electron microscope. These findings were compared with radiographical and histological observations. RESULTS: 1. At postoperative first week and second week, proliferation of periosteal vessels were more pronounced than that of endosteal vessels, which corresponded to the early new bone formation in subperiosteal area on histologic sections. 2. At postoperative third week, arterial branches from the medulla of parent bone entered into the distraction gap. Multiple longitudinal vascular branches sprouted out from the newly formed vascular network, and ran towards the interzone. 3. At postoperative fourth week, there was vascular proliferation in the periosteal side of interzone, from which branches arose towards the parent bone. 4. At postoperative sixth week, vascular networks of both sides connected to each other, and few angiogenetic findings were observed. CONCLUSIONS: In distraction osteogenesis, angiogenesis occurred actively during the distraction period and then gradually decreased with time. Taken together with radiographical and histological findings, close temporal and spatial relationship between the angiogenesis and new bone formation at the distraction site was revealed.

The investigation of microvasculature changes in osseous regeneration by guided tissue regeneration procedure

A Scanning Electron Microscopic Study on Microvascular Changes in the Monocrotaline-induced Rat Lung by Corrosion Casting Method

To investigate the microvascular changes in primary pulmonary hypertension, the lungs of 24 Sprague-Dawley rats were treated by an intraperitoneal injection of 2% monocrotaline(MCT) solution and then examined with scanning electron microscopy(SEM) after microvascular corrosion casting. Histologic examination revealed significant medial thickening in the small to medium-sized pulmonary arteries. Scanning electron microscopic findings of the normal lungs showed two kinds of microvascular structures. One showed a well-fortned three-dimensional basket structure of uniform flat-tubular alveolar capillaries, which were connected to each other in a T or Y shape or at right angles. The other revealed a two-dimensional reticular sheet of round tubular branches mainly in the bronchial artery-supplying regions. The MCT-treated groups(remodelling) showed apparent changes in both kinds of microvasculatures in comparison to the normal group but the more prominent change was found in Lbe bronchial artery microvasculature showing the dense thick encasement around large pulmonary arteries. Alveolar microvasculature of the pulmonary artery revealed individually enlarged angular appearance, with generally deformed alveolar architecture. Quantitatively, the significant enlargement of diameter and intercapillary distance appeared in both microvasculatures of MCT-induced rat lungs, but the density was increased only in the bronchial artery microvasculature. In conclusion, our three-dimensional microvascular study of the MCT-treated rat lungs demonstrates a new morphologic finding of vascular remodeling in primary puhnonary hypertension, which is thought to play an important vascular role in the pathogenesis in addition to interstitial fibrosis.

An experimental study on the vascular changes of rat molar periodontal ligament following orthodontic tooth movement using vascular corrosion casting method / 대한치과교정학회지

This study was undertaken to investigate the three dimensional vascular changes of periodontal ligament following orthodontic tooth movement. Experimental tooth movement was carried out in 96 Sprague-Dawley rats with the weight of 250g. They were divided into four experimental groups (each 24 rats). The left maxillary first molar was moved mesially with 25g force in group I, and with 75g force in group II. Each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days. In group III, 25g mesial force was applied for 3 days, and in group IV, 75g mesial force was applied for 3 days. Then the appliances were removed, and each three animals were sacrificed after 1, 6, 12, 24 hours, and 3, 7, 14, 21 days from removal of appliance. The contralateral molars were used for control group. Casting media was injected via left ventricle and polymerized in warm water. After corrosion of surrounding soft tissue, three dimensional vascular changes were examined using scanning electron microscopy. The findings of this study were as follows: 1. Pressure side of group I and II showed degenerative vascular changes such as vascular compression, reduction of vasculature, leakage of casting media. But, regenerative changes were dominant after 7 days of tooth movement. Although the degenerative vascular changes were more severe in group II, which was exposed to heavy force, the timing of these changes was not different between two groups. 2. Periodontal vasculature was reestablished by the growth of new capillaries and their differentiation and union from the remaining periodontal vessels and vessels of alveolar bone marrow. Although vascular regeneration was more rapid in group I, which was exposed to light force, the vasculature was not fully normalized in both groups even after 21 days. 3. There was no remarkable changes in tension side of group I and II, but looping of capillary, new capillary growth, dilation of vessels, redirection of vessels in the direction of tensile force were occurred. 4. In pressure side of group III and IV, in which appliance was removed after 3 days of orthodontic force, bone resorption was continued even after removal of appliance. Regeneration of vasculature was initiated after 1-6 hours, and it was more rapid in group III than group IV. In both groups, the vasculature was not fully normalized even after 21 days. 5. After removal of appliance, tension side of group III and IV showed vascular compression and loss of vasculature.

Morphological Characteristics of the Atrium as an Endocrine Organ: I. Luminal Structure of Atria in Various Animals Using Corrosion Casting Method / 체질인류학회지

The internal morphology of the right and left atria of rabbit, cat, pig, and human, particularly on the luminal structures of the auricle, were observed by stereomicroscope improving corrosion casting method using latex. Structures of the right auricular casts markedly differ from those of the left side, consisting of defined surface sturctures with distinct folds and branching patterns. The main atrial region consists of smooth surfaced single mass of the latex, and the auricular region is characterized by well developed branching patte and delicate small folds. The results of this study indicate that auricula have well organized duct-like luminal structures and many small pouches (out-pocketings) expanding the internal wall of the duct-like structures and small pouches. The endocardial nuclear imprints on the surface of the folds in the auricular region appeared larger and deeper than those on the atrium proper region of the atrial cast. These morphological observation will be aid in understanding structures of auricular lumen, regional differences of the endocardium and their function to the secretory process of atrial natriuretic peptide (ANP) release.

Anteroir Uveal Vasculature in Rabbit Eye with Scanning Electron Microscopy

Using ocularluminal methylmethacrylate corrosion casting, we obsesved three-dimentional anterior uveal microcirculation of the rabbit eyes with scanning electron microscope. The two terminal branches of each long posterior ciliary artery turn opposite direction within the iris to run concentric to the pupil; the superior and inferior branches forming the major iridic circle (MIC). Radial branches run both proximally and distally from the MIC, the former distributing to the ciliary process, choroid and ciliary body and the latter distributing to the iris. Venous drainage of the anterior uvea is taken care of by the large iridociliary veins and by marginal capillaries of the process. Each of these drains to the large vessel layer of the choroid and subsquently to the vortex vein.

Anteroir Uveal Vasculature in Rabbit Eye with Scanning Electron Microscopy

Using ocularluminal methylmethacrylate corrosion casting, we obsesved three-dimentional anterior uveal microcirculation of the rabbit eyes with scanning electron microscope. The two terminal branches of each long posterior ciliary artery turn opposite direction within the iris to run concentric to the pupil; the superior and inferior branches forming the major iridic circle (MIC). Radial branches run both proximally and distally from the MIC, the former distributing to the ciliary process, choroid and ciliary body and the latter distributing to the iris. Venous drainage of the anterior uvea is taken care of by the large iridociliary veins and by marginal capillaries of the process. Each of these drains to the large vessel layer of the choroid and subsquently to the vortex vein.