Pericardial Sacs Research Articles

A Biohybrid Material With Extracellular Matrix Core and Polymeric Coating as a Cell Honing Cardiovascular Tissue Substitute.

ObjectiveTo investigate the feasibility of a hybrid material in which decellularized pericardial extracellular matrix is functionalized with polymeric nanofibers, for use as a cardiovascular tissue substitute.BackgroundA cardiovascular tissue substitute, which is gradually resorbed and is replaced by host's native tissue, has several advantages. Especially in children and young adults, a resorbable material can be useful in accommodating growth, but also enable rapid endothelialization that is necessary to avoid thrombotic complications. In this study, we report a hybrid material, wherein decellularized pericardial matrix is functionalized with a layer of polymeric nanofibers, to achieve the mechanical strength for implantation in the cardiovascular system, but also have enhanced cell honing capacity.MethodsPericardial sacs were decellularized with sodium deoxycholate, and polycaprolactone-chitosan fibers were electrospun onto the matrix. Tissue-polymer interaction was evaluated using spectroscopic methods, and the mechanical properties of the individual components and the hybrid material were quantified. In-vitro blood flow loop studies were conducted to assess hemocompatibility and cell culture methods were used to assess biocompatibility.ResultsEncapsulation of the decellularized matrix with 70 μm thick matrix of polycaprolactone-chitosan nanofibers, was feasible and reproducible. Spectroscopy of the cross-section depicted new amide bond formation and C–O–C stretch at the interface. An average peel strength of 56.13 ± 11.87 mN/mm2 was measured, that is sufficient to withstand a high shear of 15 dynes/cm2 without delamination. Mechanical strength and extensibility ratio of the decellularized matrix alone were 18,000 ± 4,200 KPa and 0.18 ± 0.03% whereas that of the hybrid was higher at 20,000 ± 6,600 KPa and 0.35 ± 0.20%. Anisotropy index and stiffness of the biohybrid were increased as well. Neither thrombus formation, nor platelet adhesion or hemolysis was measured in the in-vitro blood flow loop studies. Cellular adhesion and survival were adequate in the material.ConclusionEncapsulating a decellularized matrix with a polymeric nanofiber coating, has favorable attributes for use as a cardiovascular tissue substitute.

Molecular Detection of a Novel Fowl Adenovirus Serotype-4 (FadV-4) from an Outbreak of Hepatitis Hydropericardium Syndrome in Commercial Broiler Chickens in Egypt.

Hepatitis hydropericardium syndrome (HHS) is an acute infectious disease caused by fowl adenovirus serotype-4 (FAdV-4), which mainly affects broilers aged 4-5 wk. During the winter of January 2021, a 32-day-old broiler flock (Cobb-500) suffered from unusually high mortality (15%) in the Alexandria Governorate, Egypt. The chickens showed depression, ruffled feathers, and greenish diarrhea besides the typical pathologic features of suspected HHS involving flabby hearts, accumulation of a straw-colored fluid in the pericardial sacs, and pale, enlarged hemorrhagic and friable livers with necrotic foci. The kidneys exhibited edema with uric acid depositions. Histopathologic examination of bird livers naturally infected with HHS showed multifocal areas of necrosis, vascular changes, and basophilic intranuclear inclusion bodies (INIB) in the hepatocytes. Molecular identification of the causative agent was accomplished by PCR and sequence analysis of the hyper-variable regions of loop 1 of the hexon gene of fowl aviadenovirus. A pathogenic strain of the novel genotype-4 (FAdV-4) was demonstrated, closely similar to the Israeli strain IS/1905/2019, with an identity of 98%. This is the first report to identify FADV-4 in Egypt, prompting further studies to elucidate its epidemiologic role in all poultry sectors and associated economic losses to provide insights to its control and prevention.

Morphology of yolk and pericardial sacs in lecithotrophic and matrotrophic nutrition in poeciliid fishes.

We used histological techniques to describe the morphology of the yolk and pericardial sacs in developing embryos of the lecithotrophic species Girardinus creolus, Gambusia puncticulata, Limia vittata, and Quintana atrizona, in comparison with the extreme matrotrophic Heterandria formosa. In lecithotrophic species, the yolk sac was enlarged and lasted until the final stages of development, while in H. formosa it was completely absorbed soon after fertilization. Lecithotrophic poeciliids showed a pericardial sac with a single layer of blood vessels covering the dorsal surface of the cephalic region only, while H. formosa showed a more complex largely vascularized pericardial sac covering the entire dorsal surface, except the caudal region. In advanced gestation of G. creolus, a vascular plexus of the yolk sac reaches the pharyngeal region, behind the gills, suggesting that the pharynx may play a role in embryonic nutrition in lecithotrophic species. These morphological evidences suggest that matrotrophy derives from lecithotrophy.

OPTIMIZED METHOD OF BOVINE PERICARDIUM DECELLULARIZATION FOR TISSUE ENGINEERING

The aim: To investigate the effectiveness of using low concentrations of sodium dodecyl sulfate (SDS) and cross-linking with EDC/NHS in the decellularization process to create a potential bioimplant for cardiac surgery. Materials and methods: Pericardial sacs were derived from 12-18 months bulls. Tissue decellularization was performed by using 0.1% SDS with the following EDC/NHS cross-linking. The experiment included standard histological, microscopic, molecular genetic and biomechanical methods. Scaffold was tested in vitro for cytotoxicity and biocompatibility. Results: A high degree of extracellular decellularized matrix purification from cells and their components was shown. Structure-function properties remained similar to those or even improved after the decellularization. During prolonged contact of BP with human fibroblasts, no cytotoxic effect was observed. The biointegration of the scaffold in laboratory animals tissues was noted confirming the potential possibility of the implant use in cardiac surgery. Conclusions: Decellularization of BP by 0.1 % SDS with NHS/EDC cross-linking is promising in manufacturing of the tissue-engineered materials in cardiac surgery.

Biocompatiblibility analysis of the decellularized bovine pericardium

The decellularized bovine pericardium and its potential use as a natural scaffold is a promising approach in the field of tissue engineering and regenerative medicine. The reaction of the host toward decellularized scaffolds depends on their biocompatibility, which should be satisfied being before applied in clinical use. Purpose: to evaluate the biocompatibility of the extracellular matrices, which were decellularized by trypsin enzyme and anionic sodium dodecyl sulfate (SDS) detergent. Material and methods. Pericardial sacs were acquired from 12-18 months’ age bulls. Tissue decellularization was performed by using 0.25 % Trypsin solution and 1 % ionic SDS for group I and 0.1 % SDS for group II samples. The implantation was performed on Wistar rats. The tissue samples were stained with hematoxylin & eosin, Congo red and Masson's Trichrome for histological analysis. Results. In group 1 in 3 months after subcutaneous implantation in rats we noticed the inflammation in surrounding tissue and degradation of the implant. Under the same conditions in animals of group 2 implant replacement with growing immature connective tissue was noted. Bio-implant of this group did not degrade, moreover it's integrated to the tissues of experimental rats. Conclusion. Our results showed that decellularized bovine pericardium by 0.1 % SDS can become an alternative material for tissue engineering and has the potential for further use in human surgery.

Pathogenicity of a fowl adenovirus serotype 4 isolated from chickens associated with hydropericardium-hepatitis syndrome in China

Hydropericardium-hepatitis syndrome (HHS) is characterized by pericardial effusion and hepatitis and causes huge economic losses in the poultry industry in China. In this study, a strain of fowl adenoviruses (FAdV-4) (GX-1) was isolated from liver samples of diseased chickens with HHS. Phylogenetic analysis based on complete genome gene revealed that GX-1 clustered with the C-type fowl adenovirus and was serotyped as FAdV-4. Pathogenicity testing showed that the GX-1 strain caused 100% mortality in 10-day-old specific pathogen-free chickens at a dose of 104 tissue culture infective doses (TCID50) within 3 d post-infection. A viral dose of 103 TCID50 resulted in a 16% survival rate before day 9 and at 102 TCID50 an 80% rate before day 6. At necropsy, livers from infected chickens were swollen and yellow brown with necrotic foci. The hearts were flabby with amber-colored and jelly-like fluid in the pericardial sacs. The kidneys were swollen and congested. Histologically eosinophilic intranuclear inclusion body could be seen in the hepatic cell. The result of histopathological examination also revealed that heart muscle fibers were fractured with extensive congestion and hemorrhaging. Other tissues like kidney, bursa of Fabricius, thymus, and spleen were observed degeneration and necrosis. Virus-specific antibodies appeared in serum beginning at day 14 and reached statistically significant levels at 21, 28, 35, and 42 dpi (P < 0.001). In conclusion, we identified a highly virulent FAdV-4 virus as causative agent of the HHS outbreak reported here. The FAdV-4 GX-1 strain will be valuable for vaccine evaluation and development to prevent and reduce the spread of HHS in the poultry industry.

Oxidative stress indices and pathological changes in cattle with traumatic pericarditis

Objectives of the study were to provide information on the changes in oxidative stress indices, as well as to describe the possible pathological changes in cattle affected with traumatic pericarditis (TP). Twenty-six cattle with TP were included in the current study. Nine clinically healthy cattle were enrolled as controls. Blood serum samples were collected and stored at -20ºC. Measurement of nitric oxide (NO), malondialdehyde (MDA), total antioxidant capacity (TAC) and other biochemical parameters were done within one week from sampling. Postmortem and histopathological examinations were carried for dead or euthanized cases. The mean values of NO, MDA, creatinine, total bilirubin, globulins, blood urea nitrogen, and total proteins were significantly higher in the diseased group (P&lt;0.05), while the mean values of TAC, glucose and albumin were significantly lowered in TP group (P&lt;0.05). The activities of aspartate aminotransferase (AST) and γ-glutamyl transferase (GGT) were higher in affected cattle than healthy ones. In cattle with TP, a strong significant positive association was found between serum concentrations of NO and MDA. Postmortem examinations of the dead animals revealed severe thickening of the pericardium and accumulation of pericardial effusions either mild or severe in the pericardial sacs. Regarding the recorded histopatholgical changes; Organized fibrinous pericarditis (constrictive pericarditis), necrosis of the myofiber with congestion and hemorrhage in the myocardium, chronic venous congestion of the liver, and hemosiderosis of the spleen were clearly observed. Furthermore, hemorrhage and interstitial fibrosis of the lung, various degrees of degeneration and hyalinization of the renal tubules were prominently featured. In conclusion, oxidative stress and lipid peroxidation may be involved in the complications of traumatic pericarditis in cattle.

Establishment of proprotein convertase, furinA knocked-out lines in medaka, Oryzias latipes, and unique form of medaka furin-like prorprotein convertase (mflPC)

Furin is a member of the subtilisin-like proprotein convertase family. Medaka furin-like proprotein convertase (mflPC), a unique form of medaka FurinA (mFurinA) (GenBank accession no. AB092685.1) was cloned from the ovary cDNA library. Compared to human furin (GenBank accession no. NM_002569.3) and mFurinA in the structural motif of mflPC, only the catalytic domain and the N-terminal region of the P domain are highly conserved, but more C-terminal domains are truncated. Based on our research, there three forms of furin, mFurinA, mflPC and mFurinB that exist in medaka. These three genes are expressed in the developing embryos and ubiquitously in adult tissues.To investigate the function of mFurinA and mflPC, as a first step, mFurinA KO lines were established. The mFurinA KO larvae with abnormal phenotypes exhibit edema, abnormal body fluid accumulation in the pericardial and yolk sacs, enlarged hearts, clogged blood vessels, structurally weak eyes, and a very short life. The data suggests that abnormal processing of TGF-β may be one of the causes of these disorders. FurinA KO medaka is a good model for the study of human diseases such as Fraser Syndrome and Marfan syndrome. The creation of human genomic disorder models using recently advanced genome editing procedures informs us of the function of key molecules and their role in causing equivalent human disorders and will be useful as a tool to identify the mechanisms involved.

Clinical presentation and ultrasonographic findings in buffaloes with congestive heart failure

The objective of this retrospective study was to describe the clinical presentation and ultrasonographic findings in water buffaloes suffering from congestive heart failure. Fifty-three buffaloes with congestive heart failure, which was confirmed postmortem, were included. The final diagnoses were traumatic pericarditis (n = 38) and vegetative endocarditis (n = 15). Ten healthy buffaloes were enrolled in this study as controls. The main clinical presentations were those related to right-sided congestive heart failure including peripheral edema, venous distension and jugular pulsation, and a sharp drop in milk yield. Only 5 buffaloes exhibited signs of left-sided heart failure. Ultrasonographic examinations showed cardiac and extracardiac lesions. Accumulation of massive anechoic fluids in the pericardial sacs, peritoneum, and pleura represented pericardial, peritoneal, and pleural effusions, respectively. In buffaloes with endocarditis, the affected valves appeared as hyperechogenic thick mass structures with nodular or proliferative vegetative lesions. Small ( 25 mm) vegetative lesions were imaged. The most affected valve was the tricuspid (n = 8), then the mitral (n = 5) and pulmonary (n = 2). In addition, perireticular abscesses, hepatomegaly, dilated caudal vena cava, and lung consolidations were also imaged. In conclusion, the prognosis seemed poor. Ultrasonography may be helpful in the evaluation of lesions in buffaloes with congestive heart failure.

A Rare Case of Deradelphus Cephalo-Thoracoomphalopagus in Lamb

Male cross-breed lamb conjoined twins were sent for examination. The twins came from a farm located in the outskirts of Palermo. The twins were spontaneously delivered and found dead by the farmer. X-ray examination and necropsy were performed. The deformity was identified as deradelphus cephalo-thoracoomphalopagus. This condition has never been reported in veterinary literature. Our case reports of male conjoined twins characterized by two separated hearts with their own pericardial sacs and two separated livers. These findings represent a rare condition in conjoined twinning.

Mouse model reveals the role of SOX7 in the development of congenital diaphragmatic hernia associated with recurrent deletions of 8p23.1

Recurrent microdeletions of 8p23.1 that include GATA4 and SOX7 confer a high risk of both congenital diaphragmatic hernia (CDH) and cardiac defects. Although GATA4-deficient mice have both CDH and cardiac defects, no humans with cardiac defects attributed to GATA4 mutations have been reported to have CDH. We were also unable to identify deleterious GATA4 sequence changes in a CDH cohort. This suggested that haploinsufficiency of another 8p23.1 gene may contribute, along with GATA4, to the development of CDH. To determine if haploinsufficiency of SOX7-another transcription factor encoding gene-contributes to the development of CDH, we generated mice with a deletion of the second exon of Sox7. A portion of these Sox7(Δex2/+) mice developed retrosternal diaphragmatic hernias located in the anterior muscular portion of the diaphragm. Anterior CDH is also seen in Gata4(+/-) mice and has been described in association with 8p23.1 deletions in humans. Immunohistochemistry revealed that SOX7 is expressed in the vascular endothelial cells of the developing diaphragm and may be weakly expressed in some diaphragmatic muscle cells. Sox7(Δex2/Δex2) embryos die prior to diaphragm development with dilated pericardial sacs and failure of yolk sac remodeling suggestive of cardiovascular failure. Similar to our experience screening GATA4, no clearly deleterious SOX7 sequence changes were identified in our CDH cohort. We conclude that haploinsufficiency of Sox7 or Gata4 is sufficient to produce anterior CDH in mice and that haploinsufficiency of SOX7 and GATA4 may each contribute to the development of CDH in individuals with 8p23.1 deletions.

Occurrence and associated lesions of Pasteurella multocida in porcine bronchopneumonia

With the aim to extend the present knowledge on possible systemic spreading of Pasteurella multocida in pigs with bronchopneumonia, the occurrence and associated lesions of P. multocida were described by comparing cultural detection, pathological evaluation and in situ hybridization of P. multocida in lungs, hearts and kidneys from cases of porcine bronchopneumonia. P. multocida was cultivated from the lung lesions in 114 out of a total of 148 cases of porcine bronchopneumonia. Among the 114 cases, P. multocida was also cultivated from the pericardial sacs of 40 pigs and the kidneys of seven pigs. Gross lesions and histological findings included a variety of type and stages of bronchopneumonia in connection to the isolation of P. multocida. Furthermore, chronic fibrous pericarditis, interstitial nephritis and a high proportion of lympho-histocytic nephritis were observed. In situ hybridization identified P. multocida in the majority of the lungs, none of the hearts and in half of the kidneys examined. The results show a possible low rate of systemic spreading of P. multocida from lung lesions in pigs with bronchopneumonia.

Topography of preganglionic parasympathetic cardiac motor neurons labeled after underwater submersion.

The mammalian diving response is marked by a robust bradycardia. Preganglionic parasympathetic cardiac motor neurons (PCMNs) are distributed in the ventrolateral medulla from the facial motor nucleus to the spinomedullary junction (see Panneton et al., Brain Res. 738:, 1996). It has been suggested that chrono-, dromo- and inotropic neurons are segregated in this column; we wished to find which neurons may be responsible for the negative chronotropism seen in diving. Rats were trained to dive underwater and then telemetric transmitters for monitoring arterial pressure implanted into their abdomens. After recovery, a thoracotomy was done and 8–20μl of 0.5–1.0% choleragenoid mixed with the vital dye fast green injected into their pericardial sacs. After 60–72 hrs, the rats dove underwater 3 times; bradycardia was dramatic with each dive, averaging near 80%. After 2 hrs, the rats were killed and their brains stained immunohistochemically for antibodies against choleragenoid and cFos. Labeled PCMNs were found throughout the ventrolateral medulla; very few were observed in the dorsal motor nucleus. Double labeled neurons also were found throughout the rostral-caudal extent of the column of PCMNs, but more were found rostrally. Supported by NIH grant HL 64772.

Inhibition of zebrafish epidermal growth factor receptor activity results in cardiovascular defects

The physiological role of any of the epidermal growth factor (EGF) receptor tyrosine kinases has yet to be determined in zebrafish. We isolated a zebrafish homologue of EGFR ( egfr) that shows a 63% amino acid overall identity to human EGFR but with 90% amino acid identity in the kinase domain. Whole mount in situ hybridization showed ubiquitous distribution of egfr transcripts during gastrulation, somitogenesis and later stages. When expressed in Chinese hamster ovary cells, zebrafish Egfr was a functional receptor that responded to EGF by receptor tyrosine phosphorylation and activation of MAP kinase. The function of zebrafish Egfr in vivo was determined by inhibiting its activity using EGFR kinase inhibitors and antisense morpholinos (MO), which inhibited Egfr kinase activity and translation of egfr messenger RNA into protein, respectively. The zebrafish is a particularly excellent model for studying cardiovascular development because zebrafish are transparent allowing direct visualization of the heart and circulation in the blood vessels. Inhibition of zebrafish Egfr activity in vivo impeded blood flow via the outflow tract into the aorta and impeded circulation in the axial and intersegmental vessels by 80 h post-fertilization. Analysis of the heart showed that the heart chambers and pericardial sacs were dilated and the outflow tracts were narrowed. Together these results suggested that zebrafish Egfr has a cardiovascular function in the developing zebrafish that is required for normal circulation.

The telescoping suture--Part II: A novel method to improve the mechanical behavior of a new biomaterial: ostrich pericardium.

Ostrich pericardium, sutured using a telescoping or overlapping technique, was studied to determine its mechanical behavior. From each of 12 pericardial sacs, four contiguous strips were cut longitudinally, from root to apex, and another four contiguous strips were cut in transverse direction. One of the strips in each set of four was used as an unsutured control and the remaining three were sutured by overlapping 0.5 cm of the tissue and sewing with Gore-tex, Prolene or Pronova. These 96 samples were then subjected to tensile testing along their major axes until rupture. The tensile stresses recorded in the suture materials at the moment tears appeared in the pericardium ranged between 55.99 MPa and 70.23 MPa for Gore-tex in samples cut in the two directions. Shear stress became ostensible at 56 MPa, with clearly evident tears. However, microfracture of the collagen fibers must be produced at much lower stress levels. The comparison of the resistance in kilograms (machine-imposed), without taking into account the sections in which the load was applied, demonstrated only a slight loss of load when the telescoping suture was employed in ostrich pericardium samples. Ostrich pericardium may continue to be an alternative biological material for the construction of heart valve leaflets.

Fatal Spirochetosis Due to a Relapsing Fever-like Borreliasp. in a Northern Spotted Owl

Acute septicemic spirochetosis was diagnosed in an adult male northern spotted owl (Strix occidentalis caurina) found dead in Kittitas County, Washington, USA. Gross necropsy findings included marked enlargement of the liver and spleen and serofibrinous deposits on the serous membranes lining the body cavities and the pericardial and perihepatic sacs. Microscopic observations included macrophage infiltration in the liver and spleen with mild thrombosis and multifocal necrosis, as well as hemorrhage and acute inflammation in the choroid plexus of the brain. No viruses or pathogenic bacteria were isolated from brain, liver, or spleen, and no parasites were found in blood smears or impression smears of the liver. Chlamydial culture attempts were unsuccessful and no chlamydial antibodies were detected in serum. In silver-stained microscopic sections and by transmission electron microscopy of liver, numerous long, thin, spiral-shaped bacteria were seen in the liver, spleen, cerebral ventricles, and within blood vessels in many organs. The organism was identified as a member of the Borrelia genus by sequence analysis of the PCR-amplified 16S rRNA gene. The most closely related species is B. hermsii, an agent of relapsing fever in humans in the western United States. This is the first report of a relapsing fever-related Borrelia in a wild bird.

Identification of proliferating cells in hard clams.

The origin of hemocytes, the circulating “blood cells” of bivalve molluscs, including hard clams (Mercenaria mercenaria) has not been identified (1, 2). Proliferation of hemocytes, however, can be recognized through their increased numbers in diseased animals. Proliferating cell nuclear antigen (PCNA), or cyclin, is a protein produced during the late G1 and S phases of the cell cycle (3, 4). Using antibodies that recognize PCNA in mice, we attempted to identify the origin of hemocytes in the hard shell clams. Quahog parasite unknown (QPX) is a protist that causes severe inflammation and mortality in infected clams (5, 6). We attempted to induce hemocyte proliferation by exposing clams to QPX in a 10-l water column in which 12 ml of undiluted QPX culture (at a concentration of 7p10 cells/ml) were added every 10 days; by injecting QPX between the membranous mantles and the right valves, 3 cm ventral anterior to the siphon and into the pericardial cavities (0.25 ml of undiluted QPX culture); and by injecting an inert particle (India ink, 1:10 dilution in sterile seawater [7, 8]) into the pericardial cavities. The controls consisted of two groups of clams. One group was injected with sterile seawater in the pericardial cavities; the other was untreated. Groups were sampled at 24 h, and at 1, 4, and 8 weeks after the start of the experiment. At sampling, the animals were shucked, fixed in 10% neutral buffered formalin (NBF) for 24 h, and embedded in paraffin. Sections were cut (4–6 mm), mounted onto positively charged slides (Fisherbrand, Superfrost/Plus and ProbeOn Plus slides) and stained either with hematoxylin and eosin (H&E) (9) or with anti-PCNA with a hematoxylin counterstain (Zymed, PCNA Staining Kit). Clams injected with QPX in the pericardial cavities showed mild focal inflammation associated with viable and necrotic QPX organisms. At 2 months post-injection, viable QPX organisms were no longer identified. QPX organisms and associated inflammation were not observed in clams injected in the mantle cavity. After 2 months of water column exposure, only very rare infection by QPX organs with minimal inflammation was observed in mantle tissue. India ink injection caused a minimal inflammatory response. Pools of injected ink in the tissues and vascular spaces were either engulfed by individual hemocytes or surrounded and sequestered by hemocytes (encapsulation), forming thin-walled granulomas (6, 10). Numerous individual hemocytes containing India ink were eliminated from the clams by diapedesis over lumenal epithelial surfaces (Fig. 1A). Thick-walled granulomas (6, 10) were also identified in the gills, pericardial sacs, and other 1 Worcester Polytechnic Institute, Worcester, MA.

Effect of Quinidine Instilled into Canine Pericardial Sac on Cardiac Effective Refractory Period

Background:Atrial fibrillation (Af) after open heart surgery may result in hypotension, heart failure, embolic complication and prolongation in length of hospital stay. Several studies have investigated the efficacy of pharmacological prophylaxis in reducing the incidence of Af after cardiac surgery. The pericardial sac represents a natural physical barrier and provides a drug receptacle to restrict drug delivery to the heart. The overall objective of this study was to determine whether the pericardial sac could function as a delivery chamber for antiarrhythmic drugs. We investigated whether quinidine delivered into the pericardial sac exerted an effect on atrial and ventricular refractoriness, impulse generation, and conduction. Methods:All animals were anesthetized with α-chloralose. After a sternotomy, the pericardium was opened and cradled to produce a “container” of approximately 30 ml. Experimental animals received quinidine, 3.33 mg/ml, dissolved in Krebs-Henseleit solution instilled into their pericardial sacs for 30 minutes. Baseline and 5, 10 and 30 minutes postinstillation electrophysiologic studies were performed. Plasma quinidine levels were measured at each of the time intervals in three different sites i.e., right ventricle (RV), aortic root and femoral vein (FV). Results:Baseline systolic (SAP) and diastolic aortic pressure (DAP) were 148±16.8 mmHg, and 111±23.9 mmHg, respectively. Both SAP and DAP were significantly decreased at 5, 10 and 30 minutes after instillation of quinidine solution into pericardial sac. In electrocardiographic parameters, the increase in sinus cycle length and corrected QT interval were significantly greater compared with baseline at each of the time intervals after instillation of quinidine solution into pericardial sac. All electrophysiologic parameters including 1:1 AV conduction, effective refractory period (ERP) of RA and RV were significantly increased compared with baseline at three time points. Quinidine concentrations in RV and aorta were significantly higher than in FV at three time points. In RV and aorta, quinidine concentrations at 30 min were significantly lower than those at 5 and 10 min postinstillation periods. There were significant correlations between plasma quinidine levels and corrected QT interval or RAERP. Conclusion:Above results showed that quinidine instilled into the pericardial sac migrates transmurally and produces significant prolongation of effective 논문접수일:1999년 9월 27일 심사완료일:2000년 2월 17일 교신저자:김재형, 130-709 서울 동대문구 전농동 620-56 가톨릭대학교 의과대학 내과학교실 전화:(02) 958-2388·전송:(02) 968-7250 E-mail:jhkim@sph.cuk.ac.kr

Optimal bovine pericardial tissue selection sites. II. Cartographic analysis.

In Part I of this work we used small-angle light scattering (SALS) to quantify the fiber architecture of 20 bovine pericardial sacs, along with corresponding tissue-thickness measurements, to determine optimal material selection sites. In order to determine the anatomic consistency of these sites, the fiber architecture and thickness data from all 20 sacs were averaged together using a cartographic analysis method that took advantage of the geometry of the prolate spheroid mold used to process the sacs. Optimal selection sites were determined based on a local criteria where all fiber preferred directions within a 2.54-cm circular area were within +/- 10 degrees. The largest contiguous area (LCA) for the entire BP sac was 20.54 cm2, located in the vicinity of the left ventricle of the heart. The LCA tissue thicknesses were also relatively uniform, further supporting the use of these areas. However, even within these optimal areas there was a +/- 20 degrees standard deviation in local fiber preferred directions, resulting in at best a 40 degrees spread in local preferred directions. The observed structural variability may be due to regionally heterogeneous physiologic loadings induced by the ligamentous attachments. These attachments may alter the regional fiber preferred orientation to support local mechanical loadings. Overall, given the inherent structural variability of the BP sac, we conclude that use of anatomic location alone will not consistently guarantee the selection of tissue specimens with a highly homogeneous and predictable fibrous structure. It is thus suggested that a direct fiber measurement presorting method be employed when selecting BP specimens for bioprosthetic applications where tissue structural homogeneity and uniformity is critical.

Concept of totally biological internal coating for newly shaped artificial ventricles.

The need for improvement of artificial heart biocompatibility led to the design of new artificial ventricles with biological internal coating and new shapes and sizes. The internal coating of these artificial ventricles is made of a molded single-piece, glutaraldehyde-preserved pericardial sac. The pericardial sac was obtained from the entire intact pericardium of Yucatan pigs. The pericardium was molded and fixed in a 0.6% glutaraldehyde buffered solution and specifically cut to obtain a truncated egg shaped sac with specific dimensions and 110 cm3 total volume. Two pericardial sacs associated with one another form a biventricular device to create a new orthotopic total artificial heart. The compliance of this device to rules pertaining to total artificial heart concept and implantation makes plausible a new total artificial heart which given its biomaterials, shape, and dimensions can provide optimal anatomical, biological, and hemodynamic conditions.