Mechanics and function in heart morphogenesis.

For years, biomechanical engineers have studied the physical forces involved in morphogenesis of the heart. In a parallel stream of research, molecular and developmental biologists have sought to identify the molecular pathways responsible for embryonic heart development. Recently, several studies have shown that these two avenues of research should be integrated to explain how genes expressed in the heart regulate early heart function and affect physical morphogenetic steps, as well as to conversely show how early heart function affects the expression of genes required for morphogenesis. This review combines the perspectives of biomechanical engineering and developmental biology to lay out an integrated view of the role of mechanical forces in heart development.     

Analysis of Deaths Related to Anesthesia in the Period 1996-2004 from Closed Claims Registered by the Danish Patient Insurance Association

Background: Anesthesia is associated with complications, and some of them may be fatal. The authors investigated the circumstances under which deaths were associated with anesthesia. In Denmark, the specialty anesthesiology encompasses emergency medicine, chronic and acute pain medicine, anesthetic procedures, perioperative care medicine, and intensive care medicine.

Methods: The authors retrospectively investigated anesthesia related deaths registered by the Danish Patient Insurance Association.

Results: From 1996 to 2004, 27,971 claims were made by the Danish Patient Insurance Association covering all medical specialties, of which 1,256 files (4.5%) were related to anesthesia. In 24 cases, the patient's death was considered to result from the anesthetic procedure: 4 deaths were related to airway management, 2 to ventilation management, 4 to central venous catheter placement, 4 as a result of medication errors, 4 from infusion pump problems, and 4 after complications from regional blockades. Severe hemorrhage caused 1 death, and in 1 case the cause was uncertain.     

A new CD43 monoclonal antibody induces homotypic aggregation of human leucocytes through a CD11a/CD18-dependent and -independent mechanism.

We describe a monoclonal antibody (mAb), designated 1.C1, that causes rapid and vigorous aggregation among normal leucocytes and among T and myeloid/monocytic cell lines. As shown by competitive binding and sequential immunoprecipitation experiments, the antigen recognized by mAb 1.C1 is a 115,000 MW sialoglycoprotein, that corresponds to the human CD43 antigen, also known as leukosialin or sialophorin. The aggregation process starts within minutes and reaches maximum level 6-18 hr after addition of the antibody. It is dependent on active cell metabolism (inhibited at low temperatures and by a mixture of the metabolic poisons azide and 2-deoxy-D-glucose), a fluid plasma membrane (inhibited by pretreatment of the cells with paraformaldehyde) and an intact cytoskeleton (inhibited by cytochalasin B). Two reference CD43 antibodies (MEM-59 and DF-T1), both binding the same or closely related sialic acid-dependent epitope as mAb 1.C1, are also capable of inducing cell clump formation. CD11a/CD18 mAb block the 1.C1-induced adhesion of resting peripheral blood leucocytes, but not of haematopoietic cell line cells. In addition, mAb 1.C1 induces homotypic aggregation of K-562 cells, which do not express members of the beta 2 integrin subfamily on their surface. These data suggest that triggering of the CD43 antigen promotes homotypic cell adhesion that is mediated by both CD11a/CD18-dependent and -independent pathways.     

Clericuzio type poikiloderma with neutropenia is distinct from Rothmund-Thomson syndrome

Two siblings from a consanguineous family presented with a poikiloderma of limbs and face, plantar keratoderma, and toenail pachyonychia. Neutropenia and neutrophil dysfunction with impairment of the respiratory burst and bacterial killing resulted in frequent respiratory tract infections. A bronchocentric granulomatous pneumonia was a fatal complication. The clinical presentation is consistent with Clericuzio type poikiloderma with neutropenia. Literature review identified several additional probable patients. Genetic linkage analysis excluded the locus of the RECQL4 gene, mutations in which have been described in some patients with the Rothmund-Thomson poikiloderma syndrome. This report confirms the clinical and genetic identity of the Clericuzio type of poikiloderma with neutropenia syndrome.     

Monocyte counting: discrepancies in results obtained with different automated instruments.

To determine the accuracy of several methods for measuring the monocyte count, the results obtained by a number of different automated cell counters were analysed. Considerable discrepancies occurred for monocyte counts obtained in normal blood among the counters. The results of a visual monocyte count on a total of 800 leucocytes were used as the reference method. The technique of measuring the monocyte count by using dual staining with monoclonal antibodies CD45 and CD14 provided the closest agreement with the reference method. Six other automated counting systems were assessed. Two of these systems (Coulter VCS and Technicon H1) gave results, which, although under-estimating monocytosis, correlated well with the results obtained by the reference technique. A third system (Toa Sysmex NE-8000) gave unreliable results. Three of the automated systems evaluated measured a "third population"--that is, monocytes together with other leucocytes. One of these systems (Ortho ELT 1500), overestimated the count, as expected, but correlated well with the reference method. The second of these "third population counters" (Coulter S Plus IV) correlated moderately well with the reference monocytosis, while the Toa Sysmex E-5000 correlated poorly. It is clear that problems exist in the evaluation of different instruments for counting monocytes. An accurate and reliable reference method is a pre-requisite to evaluate this aspect of cell counters. As the visual method is too cumbersome a different reference method would be useful. Based on the results of this study, it is suggested that the technique using fluorescence labelled monoclonal antibodies should be regarded as an acceptable alternative.     

A chromosomal profile of polycythemia vera

One hundred four patients with a diagnosis of polycythemia vera and a variable period of follow-up had one or more cytogenetic investigations. Chromosome abnormalities were found in 13% of untreated patients, in 56% of cases treated with radioactive phosphorus (32P) or cytotoxic drugs, and in 85% of patients in which transformation of the disease had occurred. Nonrandom chromosome abnormalities found before treatment included +8, +9, 13q-, 20q-; their prognostic value is little, as they are often associated with longstanding, stable disease. In contrast, 5q- anomaly and the appearance of subclones in patients with an abnormal karyotype were found to be poor prognostic signs, as they are usually coincidental with evolution of the disease to myelofibrosis or leukemia. Chromosomally two patterns of acute leukemia were observed in polycythemia vera patients. The first type resembles de novo acute leukemia, in that the clinical and cytologic characteristics of the disorder are easily defined by FAB criteria and the chromosome changes compatible with the types usually found in those conditions. In the second type, assignment to a FAB morphologic subgroup was more difficult, myelodysplastic changes were often present, and the karyotype showed complex abnormalities frequently involving chromosomes #5 and #7. All these features suggest the occurrence of secondary leukemia.     

Evaluation of bone resection margins of segmental mandibulectomy for oral squamous cell carcinoma

Resection margins are frequently studied in patients with oral squamous cell carcinoma and are accepted as a constant prognostic factor. While most evidence is based on soft tissue margins, reported data for bone resection margins are scarce. The aim of this retrospective study was to evaluate and determine the utility of surgical margins in bone resections for oral cavity squamous cell carcinoma (OCSCC). The status of bone resection margins and their impact on survival was investigated in patients who had undergone segmental mandibulectomy for OCSCC. Medical records were retrieved for the years 2000–2012; 127 patients were identified and included in the study. Tumour-positive bone resection margins were found in 21% of the patients. The 5-year overall survival was significantly lower in this group (P < 0.005). Therefore, there is a need for intraoperative feedback on the status of bone resection margins to enable immediate additional resection where necessary. Although the lack of intraoperative methods for the evaluation of bone tissue has been addressed by many authors, there is still no reliable method for widespread use. Future research should focus on an objective, accurate, and rapid method of intraoperative assessment for the entire bone resection margin to optimize patient outcomes.     

Whole plant based treatment of hypercholesterolemia with Crataegus laevigata in a zebrafish model

ABSTRACT: BACKGROUND: Consumers are increasingly turning to plant-based complementary and alternative medicines to treat hypercholesterolemia. Many of these treatments are untested and their efficacy is unknown. This multitude of potential remedies necessitates a model system amenable to testing large numbers of organisms that maintains similarity to humans in both mode of drug administration and overall physiology. Here we develop the larval zebrafish (4-30 days post fertilization) as a vertebrate model of dietary plant-based treatment of hypercholesterolemia and test the effects of Crataegus laevigata in this model. METHODS: Larval zebrafish were fed high cholesterol diets infused with fluorescent sterols and phytomedicines. Plants were ground with mortar and pestle into a fine powder before addition to food. Fluorescent sterols were utilized to optically quantify relative difference in intravascular cholesterol levels between groups of fish. We utilized the Zeiss 7-Live Duo high-speed confocal platform in order to both quantify intravascular sterol fluorescence and to capture video of the heart beat for determination of cardiac output. RESULTS: In this investigation we developed and utilized a larval zebrafish model to investigate dietary plant-based intervention of the pathophysiology of hypercholesterolemia. We found BODIPY-cholesterol effectively labels diet-introduced intravascular cholesterol levels (P < 0.05, Student's t-test). We also established that zebrafish CO declines as CH dose increases (difference between 0.1% and 8% (w/w) high cholesterol diet-treated cardiac output significant at P < 0.05, 1-way ANOVA). Using this model, we found hawthorn leaves and flowers significantly reduce intravascular cholesterol levels (P < 0.05, 1-way ANOVA) and interact with cholesterol to impact cardiac output in hypercholesterolemic fish (2-way ANOVA, P<0.05 for interaction effect). CONCLUSIONS: The results of this study demonstrate that the larval zebrafish has the potential to become a powerful model to test plant based dietary intervention of hypercholesterolemia. Using this model we have shown that hawthorn leaves and flowers have the potential to affect cardiac output as well as intravascular cholesterol levels. Further, our observation that hawthorn leaves and flowers interact with cholesterol to impact cardiac output indicates that the physiological effects of hawthorn may depend on diet.