Prevalence and type distribution of human papillomavirus infections in Danish patients diagnosed with vulvar squamous cell tumors and precursors.

OBJECTIVE: To study the prevalence and type distribution of human papillomavirus (HPV) in patients with vulvar high-grade precancerous lesions and vulvar squamous cell carcinoma (VSCC). METHODS: Formalin-fixed and paraffin-embedded (FFPE) tissue samples from Danish patients diagnosed with vulvar precancerous lesions or VSCC in the period from 2010 to 2012 were obtained. HPV-DNA detection was carried out by the use of polymerase chain reaction (PCR) using GP5+/GP6+ primers and genotyped by sequencing. A systematic literature search on the PubMed database was performed to investigate the prevalence and genotype distribution worldwide. RESULTS: In the present study population (n = 149) 52 vulvar high-grade squamous intraepithelial lesions (HSIL), 2 differentiated vulvar intraepithelial neoplasia (dVIN), and 95 VSCC cases were identified. HPV was detected in 85 patients (57.0%). Overall, a higher proportion of the vulvar high-grade precancerous lesions were HPV positive compared to VSCC (83.6% vs. 42.1%, p < 0.001). Additionally, HSIL had a significantly higher HPV-positive rate compared to keratinizing VSCC (84.6% vs. 33.3%, p < 0.001). However, the HPV positivity was comparable between HSIL and non-keratinizing VSCC (84.6% vs. 82.4%, p = 0.825). One dVIN was HPV positive whereas the other was HPV negative. HPV-16 was the most common HPV type (68.2%), followed by HPV-33 (18.8%) and HPV-18 (8.2%). CONCLUSIONS: Most vulvar HSIL and non-keratinizing VSCCs appear to be HPV associated. However, we find a high HPV association in keratinizing VSCC, which needs to be further studied. HPV-16 remains the predominant genotype, but HPV-33 also seems to play a role in the development of VSCC.

In vivo calibration of the T2* cardiovascular magnetic resonance method at 1.5 T for estimation of cardiac iron in a minipig model of transfusional iron overload.

BACKGROUND: Non-invasive estimation of the cardiac iron concentration (CIC) by T2* cardiovascular magnetic resonance (CMR) has been validated repeatedly and is in widespread clinical use. However, calibration data are limited, and mostly from post-mortem studies. In the present study, we performed an in vivo calibration in a dextran-iron loaded minipig model. METHODS: R2* (= 1/T2*) was assessed in vivo by 1.5 T CMR in the cardiac septum. Chemical CIC was assessed by inductively coupled plasma-optical emission spectroscopy in endomyocardial catheter biopsies (EMBs) from cardiac septum taken during follow up of 11 minipigs on dextran-iron loading, and also in full-wall biopsies from cardiac septum, taken post-mortem in another 16  minipigs, after completed iron loading. RESULTS: A strong correlation could be demonstrated between chemical CIC in 55 EMBs and parallel cardiac T2* (Spearman rank correlation coefficient 0.72, P < 0.001). Regression analysis led to [CIC] = (R2* - 17.16)/41.12 for the calibration equation with CIC in mg/g dry weight and R2* in Hz. An even stronger correlation was found, when chemical CIC was measured by full-wall biopsies from cardiac septum, taken immediately after euthanasia, in connection with the last CMR session after finished iron loading (Spearman rank correlation coefficient 0.95 (P < 0.001). Regression analysis led to the calibration equation [CIC] = (R2* - 17.2)/31.8. CONCLUSIONS: Calibration of cardiac T2* by EMBs is possible in the minipig model but is less accurate than by full-wall biopsies. Likely explanations are sampling error, variable content of non-iron containing tissue and smaller biopsies, when using catheter biopsies. The results further validate the CMR T2* technique for estimation of cardiac iron in conditions with iron overload and add to the limited calibration data published earlier.

Consequences of parenteral iron-dextran loading investigated in minipigs. A new model of transfusional iron overload.

Patients with blood transfusion-dependent anemias develop transfusional iron overload (TIO), which may cause cardiosiderosis. In patients with an ineffective erythropoiesis, such as thalassemia major, common transfusion regimes aim at suppression of erythropoiesis and of enteral iron loading. Recent data suggest that maintaining residual, ineffective erythropoiesis may protect from cardiosiderosis. We investigated the common consequences of TIO, including cardiosiderosis, in a minipig model of iron overload with normal erythropoiesis. TIO was mimicked by long-term, weekly iron-dextran injections. Iron-dextran loading for around one year induced very high liver iron concentrations, but extrahepatic iron loading, and iron-induced toxicities were mild and did not include fibrosis. Iron deposits were primarily in reticuloendothelial cells, and parenchymal cardiac iron loading was mild. Compared to non-thalassemic patients with TIO, comparable cardiosiderosis in minipigs required about 4-fold greater body iron loads. It is suggested that this resistance against extrahepatic iron loading and toxicity in minipigs may at least in part be explained by a protective effect of the normal erythropoiesis, and additionally by a larger total iron storage capacity of RES than in patients with TIO. Parenteral iron-dextran loading of minipigs is a promising and feasible large-animal model of iron overload, that may mimic TIO in non-thalassemic patients.

Göttingen Minipig is not a Suitable Animal Model for in Vivo Testing of Tissue-Engineered Corneal Endothelial Cell-Carrier Sheets and for Endothelial Keratoplasty.

AIM: To test the feasibility of implanting human anterior lens capsules (HALCs) with porcine corneal endothelial cells (pCEC) in vivo in Göttingen minipigs and at the same time test the suitability of Göttingen minipig as model for endothelial keratoplasty. MATERIALS AND METHODS: Cell-carrier constructs of decellularized HALC with cultured (pCEC) were created for implementation in vivo. Eight Göttingen minipigs (6 months old) underwent surgery with descemetorhexis or removal of endothelium by scraping and implementation of HALC without (animal 1-4) and with (animal 5-8) pCEC. Follow-up examinations included optical coherence tomography (OCT) imaging (1,2 and 3 months) and slit-lamp examination (<1 week as well as 1,2 and 3 months). RESULTS: Intraoperative challenges included difficulties in maintaining an anterior chamber due to soft tissue and vitreous pressure, development of corneal edema and difficulties removing Descemet's membrane because of strong adhesion to stroma. Therefore, descemetorhexis was replaced by mechanical scraping of the endothelium in animal 4-8. HALCs without pCEC were implanted in animal 1-4. Apposition to the back surface was not achieved in animal 1 and 3 because of corneal edema and poor visibility. Animal 5 was sacrificed because of a lens capsule tear. HALCs with pCEC were implanted in animal 6-8. Slit-lamp examination the first week revealed corneal edema in all animals, although mild in animals 4. One-month examination showed retrocorneal membranes with overlying corneal edema in all animals. Histology showed fibrosis in the AC and on the back surface of the cornea, compatible with the clinical diagnosis of retrocorneal membrane. CONCLUSIONS: In conclusion, the minipig is not suitable for corneal transplantation studies in vivo because of intraoperative challenges and development of retrocorneal membrane postoperatively. For in vivo testing of the surgical handling and the therapeutic potential of tissue-engineered endothelial cell-carrier constructs other animal models are required.

High-Throughput Sequencing-Based Investigation of Viruses in Human Cancers by Multienrichment Approach.

BACKGROUND: Viruses and other infectious agents cause more than 15% of human cancer cases. High-throughput sequencing-based studies of virus-cancer associations have mainly focused on cancer transcriptome data. METHODS: In this study, we applied a diverse selection of presequencing enrichment methods targeting all major viral groups, to characterize the viruses present in 197 samples from 18 sample types of cancerous origin. Using high-throughput sequencing, we generated 710 datasets constituting 57 billion sequencing reads. RESULTS: Detailed in silico investigation of the viral content, including exclusion of viral artefacts, from de novo assembled contigs and individual sequencing reads yielded a map of the viruses detected. Our data reveal a virome dominated by papillomaviruses, anelloviruses, herpesviruses, and parvoviruses. More than half of the included samples contained 1 or more viruses; however, no link between specific viruses and cancer types were found. CONCLUSIONS: Our study sheds light on viral presence in cancers and provides highly relevant virome data for future reference.

The presence of bacteria varies between colorectal adenocarcinomas, precursor lesions and non-malignant tissue.

BACKGROUND: A causal association has been suggested between certain bacteria and colorectal cancer (CRC). Only a few studies have, however, investigated the presence of these bacteria directly in colon tissue with conflicting results. It is thus uncertain which role they may have in prognosis and carcinogenesis of CRC. METHODS: Formalin-fixed and paraffin-embedded (FFPE) colorectal tissue samples from patients diagnosed with colorectal cancer (CRC)(tumor and paired normal tissue, n = 99), adenomas (n = 96), or diverticular disease (n = 104) were tested for the presence and bacterial load of Streptococcus gallolyticus (S. gallolyticus), Fusobacterium nucleatum (F. nucleatum), and Bacteroides fragilis (B. fragilis) using quantitative PCR. A subsequent broader search was conducted on a subset of samples using 16S ribosomal RNA gene sequencing. Finally, to evaluate the prognostic value, the bacterial status was compared to patient outcome. RESULTS: S. gallolyticus was not detected by qPCR in any of the investigated tissue samples and F. nucleatum and B. fragilis were found to be equally distributed in tumors, paired normal tissue, and diverticula, but significantly less present in adenomas compared to both tumors and diverticula. Neither, F. nucleatum nor B. fragilis status affected the five-year prognosis of the patients. The 16S rRNA gene sequencing data revealed that tumors were associated with the Prevotella genus while conversely adenomas and diverticula were associated with Acinetobacter genus. CONCLUSION: These findings do not support a role of F. nucleatum or B. fragilis during colorectal beginning, while S. gallolyticus was not implicated in the colorectal tissue of a Danish population. A potential role of the bacterial genera Prevotella and Acinetobacter was indicated, and requires further investigations.

Hyperoxia affects the lung tissue: A porcine histopathological and metabolite study using five hours of apneic oxygenation.

BACKGROUND: Oxygen is a liberally dosed medicine; however, too much oxygen can be harmful. In certain situations, treatment with high oxygen concentration is necessary, e.g. after cardiopulmonary resuscitation. The amount of oxygen and duration of hyperoxia causing pulmonary damage is not fully elucidated. The aim of this study was to investigate pathophysiological and metabolite changes in lung tissue during hyperoxia while the lungs were kept open under constant low pressure. METHODS: Seven pigs were exposed to 100% oxygen for five hours, using an apneic oxygenation technique with one long uninterrupted inspiration, while carbon dioxide was removed with an interventional lung assist. Arterial blood samples were collected every 30 minutes. Lung biopsies were obtained before and after hyperoxia. Microscopy and high-resolution magic angle spinning nuclear magnetic resonance spectroscopy were used to detect possible pathological and metabolite changes, respectively. Unsupervised multivariate analysis of variance and paired sample tests were performed. A two-tailed p-value ≤ 0.05 was considered significant. RESULTS: No significant changes in arterial pH, and partial pressure of carbon dioxide, and no clear histopathological changes were observed after hyperoxia. While blood glucose and lactate levels changed to a minor degree, their levels dropped significantly in the lung after hyperoxia (p ≤ 0.04). Reduced levels of antioxidants (p ≤ 0.05), tricarboxylic acid cycle and energy (p ≤ 0.04) metabolites and increased levels of several amino acids (p ≤ 0.05) were also detected. CONCLUSION: Despite no histological changes, tissue metabolites were altered, indicating that exposure to hyperoxia affects lung tissue matrix on a molecular basis.

Early mobilisation of patients with community-acquired pneumonia reduce length of hospitalisation-a pilot study.

[Purpose] To examine if length of stay was reduced following an early mobilisation programme in patients with community-acquired pneumonia, and secondary, if such a program influenced short-term rehospitalisation and mortality rates. [Participants and Methods] Ninety seven consecutive patients (51% men; over all mean ± SD age 71.9 ± 16.5 years) with community-acquired pneumonia were included in the intervention group, and compared with a historical control group of 97 patients, matching at case level. Early mobilisation was defined as more than 20 minutes out of bed within 24 hours of hospitalisation. [Results] Eighty out of 97 patients in the intervention group were mobilised within 24 hours and length of stay for all patients was reduced with an average of 1.5 (95%CI: -0.2; 3.2) days compared to the control group. There was no significant difference between the two groups according to 30-day rehospitalisation and mortality. [Conclusion] An early mobilisation program seem to reduce the length of stay for patients with community-acquired pneumonia, and without an increase in short-term mortality and re-hospitalisation rates.

The clinical outcome of LMNA missense mutations can be associated with the amount of mutated protein in the nuclear envelope.

AIMS: Lamin A/C mutations are generally believed to be associated with a severe prognosis. The aim of this study was to investigate disease expression in three affected families carrying different LMNA missense mutations. Furthermore, the potential molecular disease mechanisms of the mutations were investigated in fibroblasts obtained from mutation carriers. METHODS AND RESULTS: A LMNA-p.Arg216Cys missense mutation was identified in a large family with 36 mutation carriers. Disease expression was unusual with a late onset and a favourable prognosis. Two smaller families with severe disease expression were shown to carry a LMNA-p.Arg471Cys and LMNA-p.Arg471His mutation, respectively. LMNA gene and protein expression was investigated in eight different mutation carriers by quantitative reverse transcriptase polymerase chain reaction, Western blotting, immunohistochemistry, and protein mass spectrometry. The results showed that all mutation carriers incorporated mutated lamin protein into the nuclear envelope. Interestingly, the ratio of mutated to wild-type protein was only 30:70 in LMNA-p.Arg216Cys carriers with a favourable prognosis while LMNA-p.Arg471Cys and LMNA-p.Arg471His carriers with a more severe outcome expressed significantly more of the mutated protein by a ratio of 50:50. CONCLUSION: The clinical findings indicated that some LMNA mutations may be associated with a favourable prognosis and a low risk of sudden death. Protein expression studies suggested that a severe outcome was associated with the expression of high amounts of mutated protein. These findings may prove to be helpful in counselling and risk assessment of LMNA families.

Mid-term function and remodeling potential of tissue engineered tricuspid valve: Histology and biomechanics.

OBJECTIVE: Tricuspid valve reconstruction using a small intestinal submucosal porcine extracellular matrix (ECM) tube graft is hypothesized to be durable for six months and show signs of recellularization and growth potential. The purpose was to histologically and biomechanically test ECM valves before and after six months of implantation in pigs for comparison with native valves. METHODS: Ten 60 kg pigs were included, which survived tricuspid valve tube graft insertion. Anterior and septal tricuspid leaflets were explanted from all animals surviving more than one month and examined histologically (n = 9). Endothelialization, collagen content, mineralization, neovascularization, burst strength and tensile strength were determined for native valves (n = 5), ECM before implantation (n = 5), and ECM after six months (n = 5). RESULTS: Collagen density was significantly larger in ECM at implantation (baseline) compared to native leaflet tissue (0.3 ±â€¯0.02 mg/mm3 vs. 0.1 ±â€¯0.03 mg/mm3, p < .0001), but collagen density decreased and reached native leaflet collagen content, six months after ECM implantation (native vs. ECM valve at six months: 0.1 ±â€¯0.03 mg/mm3 vs. 0.2 ±â€¯0.05 mg/mm3, p = .8). Histologically, ECM valves showed endothelialization, host cell infiltration and structural collagen organization together with elastin generation after six months, indicating tissue remodeling and -engineering together with gradual development of a close-to-native leaflet structure without foreign body response. CONCLUSIONS: ECM tricuspid tube grafts were stronger than native leaflet tissue. Histologically, the acellular ECM tube grafts showed evidence of constructive tissue remodeling with endothelialization and connective tissue organization. These findings support the concept of tissue engineering and recellularization, which are prerequisites for growth.

Rupture of an Abdominal Aortic Aneurysm in a Young Man with Marfan Syndrome.

Abdominal aortic aneurysms (AAAs) are very rare in Marfan syndrome. We present a case with a young nonsmoking and normotensive male with Marfan syndrome, who developed an infrarenal AAA that presented with rupture to the retroperitoneal cavity causing life-threatening bleeding shock. The patient had acute aortic surgery and survived. Five months before this incident, the patient had uneventful elective aortic root replacement (ad modum David) due to an enlarged aortic root. At that time, his abdominal aorta was assessed with a routine ultrasound scan that showed a normal-sized abdominal aorta. This documents that the aneurysm had evolved very rapidly despite young age and absence of risk factors.

HPV16 E6 and E7 Upregulate Interferon-Induced Antiviral Response Genes ISG15 and IFIT1 in Human Trophoblast Cells.

Human papillomavirus (HPV) is suggested to infect trophoblasts in the placenta, and HPV infections are reported to be more prevalent in pregnancies with adverse outcomes. Results are however controversial, and studies investigating the molecular consequences of placental HPV infections are lacking. We studied HPV DNA localization in the placenta in cases of spontaneous abortion/spontaneous preterm delivery as well as in elective abortion/normal full-term delivery. Using in vitro assays, we investigated downstream effects of HPV16 E6 and E7 expression in trophoblast cells at the gene expression level in order to gain increased biological insight into the interaction between HPV and the cellular host. Fluorescent in situ hybridization (FISH), combined with fluorescent immunohistochemistry (FIHC) to target the trophoblast marker CK7 clearly showed, that HPV DNA resides within syncytiotrophoblast cells in the placenta. In vitro HPV16 E6 and E7-transfected trophoblasts were analyzed by RNA sequencing, and results were validated by reverse transcription real time polymerase chain reaction (RT-qPCR) for selected genes in cell lines, as well as in patient material. We show that HPV16 E6 and E7 upregulate interferon-induced antiviral response genes ISG15 and IFIT1 in a human trophoblast cell line two-days post-transfection. This is a response that is not observed when assessing the gene expression levels of the same genes in HPV16-positive placenta samples. Investigations on viral activity find that HPV16 E6 and E7 are not transcribed in patients, possibly suggesting that HPV16 syncytiotrophoblast infection may be latent. We conclude that HPV localizes to syncytiotrophoblast cells of the placenta, and that active expression of HPV16 E6 and E7 induce an immediate interferon-induced antiviral response in trophoblast cells, which is not present in HPV-positive placenta samples, suggesting latent infection.

Human papillomavirus infects placental trophoblast and Hofbauer cells, but appears not to play a causal role in miscarriage and preterm labor.

INTRODUCTION: Recently, an association between human papillomavirus infection and both spontaneous abortion and spontaneous preterm delivery was suggested. However, the reported human papillomavirus prevalence in pregnant women varies considerably and reliable conclusions are difficult. We aimed to investigate human papillomavirus infection in placental tissue of a Danish study cohort. Furthermore, we studied the cellular localization of human papillomavirus. MATERIAL AND METHODS: In this prospective case-control study, placental tissue was analyzed for human papillomavirus infection by nested PCR in the following four study groups: full-term delivery (n = 103), spontaneous preterm delivery (n = 69), elective abortion (n = 54), and spontaneous abortion (n = 44). Moreover, human papillomavirus cellular target was identified using in situ hybridization. RESULTS: Human papillomavirus prevalence in placental tissue was 8.7% in full-term deliveries, 8.8% in spontaneous preterm deliveries, 10.9% in spontaneous abortions, and 20.4% in elective abortions. Twelve different human papillomavirus types were detected, and placental human papillomavirus infection was associated to a disease history of cervical cancer. Human papillomavirus DNA was identified in trophoblast cells, cells of the placental villi mesenchyme including Hofbauer cells, and in parts of the encasing endometrium. CONCLUSION: Placental human papillomavirus infections are not likely to constitute a risk factor for spontaneous preterm labor or spontaneous abortions in the Danish population, although an effect of human papillomavirus DNA in placental cells cannot be excluded.

How Heart Valves Evolve to Adapt to an Extreme-Pressure System: Morphologic and Biomechanical Properties of Giraffe Heart Valves.

BACKGROUND: Heart valves which exist naturally in an extreme-pressure system must have evolved in a way to resist the stresses of high pressure. Giraffes are interesting as they naturally have a blood pressure twice that of humans. Thus, knowledge regarding giraffe heart valves may aid in developing techniques to design improved pressure-resistant biological heart valves. METHODS: Heart valves from 12 giraffes and 10 calves were explanted and subjected to either biomechanical or morphological examinations. Strips from the heart valves were subjected to cyclic loading tests, followed by failure tests. Thickness measurements and analyses of elastin and collagen content were also made. Valve specimens were stained with hematoxylin and eosin, elastic van Gieson stain, Masson's trichrome and Fraser-Lendrum stain, as well as immunohistochemical reactions for morphological examinations. RESULTS: The aortic valve was shown to be 70% (95% CI 42-103%) stronger in the giraffe than in its bovine counterpart (p <0.001). No significant difference was found between mitral or pulmonary valves. After normalization for collagen, no significant differences were found in strength between species. The giraffe aortic valve was found to be significantly stiffer than the bovine aortic valve (p <0.001), with no significant difference between mitral and pulmonary valves. On a dry weight basis, the aortic (10.9%), pulmonary (4.3%), and mitral valves (9.6%) of giraffes contained significantly more collagen than those of calves. The elastin contents of the pulmonary valves (2.5%) and aortic valves (1.5%) were also higher in giraffes. CONCLUSIONS: The greater strength of the giraffe aortic valve is most likely due to a compact collagen construction. Both, collagen and elastin contents were higher in giraffes than in calves, which would make giraffe valves more resistant to the high-pressure forces. However, collagen also stiffens and thickens the valves. The mitral leaflets showed similar (but mostly insignificant) trends in strength, stiffness, and collagen content.

The Prevalence of Oropharyngeal Dysphagia in Danish Patients Hospitalised with Community-Acquired Pneumonia.

Community-acquired pneumonia (CAP) and oropharyngeal dysphagia (OD) are prevalent conditions in the elderly. The aim of this study was to explore the relationship between CAP, OD, and frailty in patients admitted to a department of respiratory medicine at a regional hospital. The outcome was mortality during hospitalization and within 30 days of discharge and rehospitalization within 30 days of discharge. A total of 154 consecutive patients (54.5% male, mean age 77.4 years (SD 11.51)) hospitalized because of CAP from September 1, 2013 to March 31, 2014 at North Denmark Regional Hospital were included in this study. The volume-viscosity swallow test was conducted for each patient. A total of 34.42% patients presented with OD. Patients with OD and CAP presented significant differences in age, CURB-65, and dementia compared with those of patients with CAP alone. The majority lived in nursing homes, had a lower body mass index, Barthel 20 score, and handgrip strength, and had poor oral health compared with patients with CAP only. Patients with OD presented an increased length of stay in hospital (P < 0.001), intra-hospital mortality (P < 0.001), and 30-day mortality rate (P < 0.001) compared with those of patients with CAP only. Their rate of rehospitalization 0-30 days after discharge was also increased (P < 0.001) compared with that of patients with CAP only. Thus, OD is related to frailty and poor outcome.

Lymph vessels: the forgotten second circulation in health and disease.

The lymphatic circulation is still a somewhat forgotten part of the circulatory system. Despite this, novel insights in lymph angiogenesis in health and disease, application of immune markers for lymphatic growth and differentiation and also the introduction of new imaging techniques to visualize the lymphatic circulation have improved our understanding of lymphatic function in both health and disease, especially in the last decade. These achievements yield better understanding of the various manifestations of lymph oedemas and malformations, and also the patterns of lymphovascular spread of cancers. Immune markers that recognize lymphatic endothelium antigens, such as podoplanin, LYVE-1 and Prox-1, can be successfully applied in diagnostic pathology and have revealed (at least partial) lymphatic differentiation in many types of vascular lesions.

Human Papillomavirus Infection as a Possible Cause of Spontaneous Abortion and Spontaneous Preterm Delivery.

Based on the current literature, we aimed to provide an overview on Human Papillomavirus prevalence in normal pregnancies and pregnancies with adverse outcome. We conducted a systematic literature search in PubMed and Embase. Data extracted from the articles and used for analysis included HPV prevalence, pregnancy outcome, geographical location, investigated tissue types, and HPV detection methods. The overall HPV prevalence in normal full-term pregnancies was found to be 17.5% (95% CI; 17.3-17.7) for cervix, 8.3% (95% CI; 7.6-9.1) for placental tissue, 5.7% (95% CI; 5.1-6.3) for amniotic fluid, and 10.9% (95% CI; 10.1-11.7) for umbilical cord blood. Summary estimates for HPV prevalence of spontaneous abortions and spontaneous preterm deliveries, in cervix (spontaneous abortions: 24.5%, and preterm deliveries: 47%, resp.) and placenta (spontaneous abortions: 24.9%, and preterm deliveries: 50%, resp.), were identified to be higher compared to normal full-term pregnancies (P < 0.05 and P < 0.0001). Great variation in HPV prevalence was observed between study populations of different geographical locations. This review demonstrates an association between spontaneous abortion, spontaneous preterm delivery, and the presence of HPV in both the cervix and the placenta. However, a reliable conclusion is difficult to draw due to the limited number of studies conducted on material from pregnancies with adverse outcome and the risk of residual confounding.

The thick left ventricular wall of the giraffe heart normalises wall tension, but limits stroke volume and cardiac output.

Giraffes--the tallest extant animals on Earth--are renowned for their high central arterial blood pressure, which is necessary to secure brain perfusion. Arterial pressure may exceed 300 mmHg and has historically been attributed to an exceptionally large heart. Recently, this has been refuted by several studies demonstrating that the mass of giraffe heart is similar to that of other mammals when expressed relative to body mass. It thus remains unexplained how the normal-sized giraffe heart generates such massive arterial pressures. We hypothesized that giraffe hearts have a small intraventricular cavity and a relatively thick ventricular wall, allowing for generation of high arterial pressures at normal left ventricular wall tension. In nine anaesthetized giraffes (495±38 kg), we determined in vivo ventricular dimensions using echocardiography along with intraventricular and aortic pressures to calculate left ventricular wall stress. Cardiac output was also determined by inert gas rebreathing to provide an additional and independent estimate of stroke volume. Echocardiography and inert gas-rebreathing yielded similar cardiac outputs of 16.1±2.5 and 16.4±1.4 l min(-1), respectively. End-diastolic and end-systolic volumes were 521±61 ml and 228±42 ml, respectively, yielding an ejection fraction of 56±4% and a stroke volume of 0.59 ml kg(-1). Left ventricular circumferential wall stress was 7.83±1.76 kPa. We conclude that, relative to body mass, a small left ventricular cavity and a low stroke volume characterizes the giraffe heart. The adaptations result in typical mammalian left ventricular wall tensions, but produce a lowered cardiac output.

Saffold virus infection associated with human myocarditis.

BACKGROUND: Saffold virus was described in 2007 as one of the first human viruses within the genus cardioviruses. Cardioviruses may cause severe infections of the myocardium in animals, and several studies have associated saffold virus with human disease. As a result, saffold virus has been isolated from different anatomical compartments, including the myocardium, but, until now, it has not been possible to demonstrate the accompanying histopathological signs of inflammation. OBJECTIVES: The aim of the study was to examine if saffold virus is capable of causing invasive infection in the human myocardium. STUDY DESIGN: Using real-time PCR, we retrospectively examined formalin-fixed paraffin embedded cardiac tissue specimens from 150 deceased individuals diagnosed with myocarditis at autopsy. The results were compared with histological findings. RESULTS AND CONCLUSIONS: Saffold virus was detected in the myocardium, lung tissue and blood of one child and was accompanied by histopathological inflammation in the heart and lungs, which was supportive of a viral infection. These findings suggest that cardioviruses may be associated with myocarditis in humans.

Diet-induced pre-diabetes slows cardiac conductance and promotes arrhythmogenesis.

BACKGROUND: Type 2 diabetes is associated with abnormal electrical conduction and sudden cardiac death, but the pathogenic mechanism remains unknown. This study describes electrophysiological alterations in a diet-induced pre-diabetic rat model and examines the underlying mechanism. METHODS: Sprague-Dawley rats were fed either high-fat diet and fructose water or normal chow and water for 6 weeks. The electrophysiological properties of the whole heart was analyzed by in vivo surface ECG recordings, as wells as ex vivo in Langendorff perfused hearts during baseline, ischemia and reperfussion. Conduction velocity was examined in isolated tissue strips. Ion channel and gap junction conductances were analyzed by patch-clamp studies in isolated cardiomyocytes. Fibrosis was examined by Masson's Trichrome staining and thin-layer chromatography was used to analyze cardiac lipid content. Connexin43 (Cx43) expression and distribution was examined by western blotting and immunofluorescence respectively. RESULTS: Following 6 weeks of feeding, fructose-fat fed rats (FFFRs) showed QRS prolongation compared to controls (16.1 ± 0.51 (n = 6) vs. 14.7 ± 0.32 ms (n = 4), p < 0.05). Conduction velocity was slowed in FFFRs vs. controls (0.62 ± 0.02 (n = 13) vs. 0.79 ± 0.06 m/s (n = 11), p < 0.05) and Langendorff perfused FFFR hearts were more prone to ventricular fibrillation during reperfusion following ischemia (p < 0.05). The patch-clamp studies revealed no changes in Na(+) or K(+) currents, cell capacitance or gap junctional coupling. Cx43 expression was also unaltered in FFFRs, but immunofluorescence demonstrated an increased fraction of Cx43 localized at the intercalated discs in FFFRs compared to controls (78 ± 3.3 (n = 5) vs. 60 ± 4.2 % (n = 6), p < 0.01). No fibrosis was detected but FFFRs showed a significant increase in cardiac triglyceride content (1.93 ± 0.19 (n = 12) vs. 0.77 ± 0.13 nmol/mg (n = 12), p < 0.0001). CONCLUSION: Six weeks on a high fructose-fat diet cause electrophysiological changes, which leads to QRS prolongation, decreased conduction velocity and increased arrhythmogenesis during reperfusion. These alterations are not explained by altered gap junctional coupling, Na(+), or K(+) currents, differences in cell size or fibrosis.