A case of occipitalization in the human skull.

Occipitalization of the atlas is an osseous anomaly of the craniovertebral junction. The aim of this paper is to present an anatomical variant of the fused atlas with the occipital bone and discuss similar cases described in literature. The skull of an adult male analysed in this study belonged to the cranial collection of the Department of Anatomy of the Jagiellonian University, Medical Collage. A tight bony fusion between the anterior arch of the atlas, the left portion of the posterior arch, the lateral masses of the atlas, and the occipital bone was observed. Hence, the left and right superior articular facets of the atlas were fused with the corresponding occipital condyles. The anteroposterior dimension of both inferior articular facets was the same (20 mm), while the transverse diameter of the right one was considerably smaller (12 mm). The transverse diameter of the left inferior articular facets was 17 mm. The right and the left transverse process of the atlas were normally developed, each of them contained transverse foramen, and they were not fused with the occipital bone. The circumference of the foramen magnum was minimally diminished by the osseous structures of the atlas fused to the occipital bone. The sagittal and transverse diameters of the foramen magnum (38 mm x 34 mm) were within the normal range of variation. However, the asymmetrical anatomy of the inferior articular facets of the atlas give rise to speculation that movement in the atlantoaxial joint was disturbed by assimilation with the occipital bone.

A model for increasing patient safety in the intensive care unit: increasing the implementation rates of proven safety measures.

BACKGROUND: Few published data exist with respect to current implementation of interventions that increase patient safety in intensive care units (ICUs) Furthermore, even less published data exist that address implementation of outcome-related methodologies of patient safety interventions in ICUs. OBJECTIVE: The purpose of this study was threefold: (1) to increase implementation rates of known, evidence-based interventions in the Dartmouth Hitchcock Medical Center (DHMC) ICU that have been demonstrated to reduce morbidity and mortality in critically ill patients; (2) to develop a durable and reproducible intervention model that can be applied not only to various aspects of ICU medicine but to any healthcare microsystem that is process oriented; and (3) to design an "ICU-specific" value compass. DESIGN: Using a before/after study design, the interventions involved: (1) establishing a systematic approach to integrate the delivery of proven ICU safety measures; (2) using the design of the various tools to develop a method for team communication and team building; (3) incorporating prompts into a ICU progress note for the healthcare team to address three evidence-based measures on a daily basis; and (4) using a data wall to demonstrate progress and to provide "real-time" feedback for error correction. SETTING AND PARTICIPANTS: In the before and after study, two groups of 40 consecutive patients admitted to DHMC's Intensive Care Unit were evaluated. The first group of patients was admitted between April and May of 2003. The second group of 40 patients was admitted between May and June of 2004. To ensure process stability, control data were also collected on patients at an interval time point between these two groups. MAIN OUTCOME MEASURES: Three evidence-based interventions were identified that reduce the likelihood of adverse events resulting simply from an ICU stay: (1) prophylaxis against venous thrombo-embolic disease (venous thromboembolism or deep vein thrombosis); (2) prophylaxis against ventilator-associated pneumonia (VAP); and (3) prophylaxis against stress-ulcers (SU). Two data points were obtained per patient per day corresponding to the work shift schedule in the ICU. The unit of measure was patient-shift observation. A limited data set was collected before implementing the change package to ensure system stability. RESULTS: Both traditional statistical analysis and statistical process control (SPC) were used to evaluate the results. For each metric, it was possible to demonstrate an increase in the measure of the mean, reduced point-to-point variation as well as a substantial narrowing of the control limits indicating improved process control. LIMITATIONS: By virtue of the involvement of the researcher in the data collection for the control group, the potential existed for methodological bias by acting on the information collected. There was also the lack of a cohesive data structure from which to collect information (ie, the hospital computer speaks one language, the ventilator a second and the monitoring systems a third). CONCLUSIONS: A model for changing the ICU microsystem at DHMC was created that enabled successful implementation of evidence-based measures by maximising the natural flow of work and fostering a team-based culture to improve patient safety. Unique to this method and unlike currently available methods that define only the delivery of the appropriate intervention as success, system success was defined in terms of both true positives, namely delivering care when it is indicated, as well as true negatives, not delivering care when there is none indicated, to offer a more comprehensive system review. Additionally, the method of data collection allowed simplified defect analysis, thereby eliminating a resource-consuming audit of data after the fact. This approach, therefore, provides a basis for adapting and redesigning the PDSA cycle so as to specifically apply this type of "disciplinary" work.

Bilateral ossification of the stylohyoid ligament.

This paper presents the case of an adult male skull with bilateral ossification of the stylohyoid complex. The total length of the stylohyoid complex amounts to 62 mm on the left side and 65 mm on the right side. Visual inspection of the stylohyoid revealed the presence of callosities that are located on both stylohyoid complexes at nearly the same level. These sites are regarded as the ossified attachments of the stylohyoid ligaments to the corresponding styloid processes. The skull studied is an example of extreme development of the stylohyoid complex, which could cause severe pain and a restriction of head and neck movement.

An AFM study on mechanical properties of native and dimethyl suberimidate cross-linked pericardium tissue.

Changes in the stiffness of hog pericardium tissue, native and treated with dimethyl suberimidate (DMS), are investigated by atomic force microscopy (AFM). Young's modulus is calculated on the basis of the Hertz-Sneddon model. The cross-linking process increases the stiffness of the tissue. The values of Young's modulus are higher for the DMS stabilized pericardium than for the native one. We also observe that the Young's modulus of native tissue increases when the time between getting the biological material and performing the measurements is longer. This process is probably connected with natural degradation of the biological samples.

The clinical significance of the petroclinoid ligament.

This report describes the topography and structure of the petroclinoid ligament with reference to its clinical significance. Observations of this ligament were performed on 24 sections of human heads. Remnants of the ossified form of this ligament were sought in 73 dry human skulls. It was found that the petroclinoid ligament existed as an anterior and posterior fold of the dura mater and stretched from the petrous apex and the anterior and posterior clinoid process respectively. We assessed the close proximity of this ligament to the oculomotor nerve. In one case we found a partially ossified posterior petroclinoid ligament, which appeared as a bony spike that arose posteriorly and inferiorly from the posterior clinoid process.

Tannic acid-stabilized pericardium tissue: IR spectroscopy, atomic force microscopy, and dielectric spectroscopy investigations.

Infrared (IR) spectroscopy, atomic force microscopy (AFM), and dielectric spectroscopy methods were employed to study structural and dynamic changes in the tannic acid (TA)-stabilized pericardium tissue. Chemically stabilized pericardium tissue is widely used in construction of the tissue derived bioprostheses. IR spectra recorded in the range 400-4000 cm-1 allowed us to recognize different types of TA-collagen interactions. Formation of hydrogen bonds between amine as well as amide NH groups from collagen and hydroxyl groups of TA was analyzed. The AFM imaging showed that the stabilization procedure with TA introduces considerable changes in both surface topography and thickness of collagen fibrils as well as in fibril arrangement on the tissue surface. It was found, that these structural changes have an impact on the dielectric behavior of the TA-stabilized tissue. The dielectric spectra for the native and TA-stabilized tissues were measured in the frequency and temperature ranges of 10(-1) -10(7) Hz and 120-270 K, respectively. The dielectric spectra revealed the relaxation process due to orientation of bound water supplemented by the fluctuation of collagen polar side groups. At the temperatures above approximately 210 K, the relaxation due to ion migration process was observed. It was found that both relaxation processes were influenced by the TA-collagen interaction.

Atomic force microscopy and FT-IR spectroscopy investigations of human heart valves.

Human aortic, mitral, tricuspid and pulmonary heart valves were investigated by the contact mode atomic force microscopy (AFM) in air, and using FT-IR spectroscopy in the frequency range 950-4000 cm(-1). Heart valves were collected post mortem from 65-78 years old patients who died from non-cardiac diseases. All of the examined valves showed considerable heterogeneity in the surface topography of collagen fibrils as well as in their organization on the tissue surface. The AFM images revealed areas with significantly different spatial organization of the collagen fibril bundles. We observed zones with multidirectional, stacked collagen fibrils as well as areas of thin fibrils packed regularly, densely and "in phase". The majority of the collagen fibrils reproduced the typical transverse D-banding pattern, with the band interval varying in rather wide range of 70-90 nm. Using AFM imaging, objects that correspond to some pathological states of heart valves at their early stages, i.e. some forms of mineral deposits, were observed. The FT-IR spectra allowed us to recognize main components, i.e. collagen and elastin, in di.erent layers (ventricularis, fibrosa) of the valve leaflets as well as they gave also support for the presence of mineral deposits on the valve surface. The presented results showed, that the AFM imaging and FT-IR spectroscopy can be applied as a complementary methods for structural characterization of heart valves at the molecular and supramolecular levels.

Atomic force microscopy investigation of chemically stabilized pericardium tissue.

Native and chemically stabilized porcine pericardium tissue was imaged by the contact mode atomic force microscopy (AFM), in air. Chemically stabilized pericardium is used as a tissue-derived biomaterial in various fields of the reconstructive and replacement surgery. Collagen type I is the main component of the fibrous layer of the pericardium tissue. In this study, the surface topography of collagen fibrils in their native state in tissue and after chemical stabilization with different cross-linking reagents: glutaraldehyde (GA), dimethyl suberimidate (DMS) and tannic acid (TA) was investigated. It has been found that chemical stabilization causes considerable changes in the surface topography of collagen fibrils as well as in the spatial organization of the fibrils within the tissue. The observed changes in the D-spacing pattern of the collagen fibril correspond to the formation of intrafibrilar cross-links, whereas formation of interfibrilar cross-links is mainly responsible for the observed tangled spatial arrangement of fibrils and crimp structure of the tissue surface. The crimp structure was distinctly seen for the GA cross-linked tissue. Surface heterogeneity of the cross-linking process was observed for the DMS-stabilized tissue. SDS-PAGE electrophoresis was performed in order to evaluate the stabilization effect of the tissues treated with the cross-linking reagents. It has been found that stabilization with DMS, GA or TA enhances significantly the tissue resistance to SDS/NaCl extraction. The relation between the tissue stability and changes in the topography of the tissue surface was interpreted in terms of different nature of cross-links formed by DMS, GA and TA with collagen.

Direction of protein biosynthesis as a reflection of the prebiotic environment

Systematical analyses of the folding pathways of simple polypeptides show that for systems containing L-stereoisomers their natural tendency to be right-handed abakes when the polypeptide terminal are naturally charged. This disadvantageous effect is minimized by an introduction of charged amino acid residues into the polypeptide chain at the beginning of its synthesis. Since in the rebiotic environment negatively charged amino acids were more prominent than positively charged ones, we conclude that the fixed direction of protein biosynthesis might be a result of "a broken symmetry" of amino acid charges.Copyright 1997 Academic Press Limited Copyright 1997 Academic Press Limited

The influence of radapertization upon some sensory properties of black pepper.

Radapertization may be used as an effective method for sterilization of spices. A possible influence of irradiation upon the sensoric qualities should be considered in this context. Therefore the objectives of the work were: --to determine the influence of the irradiation of pepper upon its sensoric quality --to determine the qualitative changes of volatile chemical substances under the influence of the irradiation of pepper --to determine correlation between changes resulting from irradiation and the sensoric quality of pepper. The spice was irradiated with doses of 10, 20, 40 and 60 kGy. Thresholds of recognition and difference were determined. It was established that the quantity of the dose is related to the values of thresholds mentioned above. The larger the dose was the less intensive the flavour became and the higher the thresholds. These interdependences were written in a form of mathematical formulas. A significant influence of irradiation upon the decrease of the quantity of essential oils and carbohydrates was noticed. These relations were also presented in a form of mathematical formulas. The work provides evidence for the fact that there is a relation between the results of sensoric assessments and the chemical characteristics (the content of volatile carbonyl, sulphuric and nitrogenic substances). Correlation between these factors was determined on the basic statistical analysis of the results obtained during our investigations.