Identification of 7 alpha-hydroxy-3-oxo-4-cholestenoic acid in chronic subdural hematoma.

We detected a novel kind of bile acid in the content of chronic subdural hematoma. This substance was specifically found in chronic subdural hematoma, and not in subdural hygroma, which is pathologically similar except for the lack of capsular membrane. The compound was identified as 7 alpha-hydroxy-3-oxo-4-cholestenoic acid by high performance liquid chromatography, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectrometry. The structure was confirmed by the comparison with the chemically synthesized compound. The average contents in chronic subdural hematoma were 658.09 +/- 137.53 ng/ml, while those in normal human plasma were 126.27 +/- 17.73 ng/ml. It was not detected in normal cerebrospinal fluid. The higher level in chronic subdural hematoma than human plasma strongly suggests the local, extrahepatic production of this type of C27 bile acids.     

Klinische presentatie van het chronisch subduraal hematoom bij ouderen

A 87-year old man was admitted to our hospital with decline in cognition and mobility and visual hallucinations. CT scanning revealed a bilateral chronic subdural hematoma. The hematoma was probably caused by a recent fall, while the patient was using acenocoumarol. Chronic subdural hematoma (CSDH) is a frequently occurring intracranial bleeding in the elderly. It usually occurs after a minor trauma and may present with a variety of symptoms. The differentiation between CSDH and other disorders like dementia can be difficult when the hematoma presents with cognitive decline and neuropsychiatic symptoms, such as hallucinations.     

Neurosurgical complications of anticoagulant therapy

Ten cases of subdural hematoma and one case of spinal epidural hematoma encountered in patients who were receiving anticoagulant therapy are discussed.This surprisingly large number of complications was observed within three years in a single hospital and represents 36.6% of all chronic and subacute subdural hematomas seen during the same period. The cases are analyzed and the conclusion reached that the causal relationship between anticoagulant therapy and hemorrhage cannot be denied.Suggestions are made as to how to decrease the danger of such complications.     

Patterns and Potential Drivers of Dramatic Changes in Tibetan Lakes, 1972–2010

Most glaciers in the Himalayas and the Tibetan Plateau are retreating, and glacier melt has been emphasized as the dominant driver for recent lake expansions on the Tibetan Plateau. By investigating detailed changes in lake extents and levels across the Tibetan Plateau from Landsat/ICESat data, we found a pattern of dramatic lake changes from 1970 to 2010 (especially after 2000) with a southwest-northeast transition from shrinking, to stable, to rapidly expanding. This pattern is in distinct contrast to the spatial characteristics of glacier retreat, suggesting limited influence of glacier melt on lake dynamics. The plateau-wide pattern of lake change is related to precipitation variation and consistent with the pattern of permafrost degradation induced by rising temperature. More than 79% of lakes we observed on the central-northern plateau (with continuous permafrost) are rapidly expanding, even without glacial contributions, while lakes fed by retreating glaciers in southern regions (with isolated permafrost) are relatively stable or shrinking. Our study shows the limited role of glacier melt and highlights the potentially important contribution of permafrost degradation in predicting future water availability in this region, where understanding these processes is of critical importance to drinking water, agriculture, and hydropower supply of densely populated areas in South and East Asia.     

Transformation of Chlorites by Primary Biological Agents—A Synthesis of X-ray Diffraction Studies

Chlorites in the bio interaction zone (or rhizosphere soils) are transformed by bacteria, fungi and mosses into expanding 2:1 minerals with different cation fixation capacities. Some of the new clays are smectitic, expanding with glycol treatment in the Ca-saturated state, while others have a high intensity 001 peak unchanged by glycol treatment. Most of all, potassium saturation results in different hydration states in mixed layered phases or as individual illitic units or minerals indicating dissimilarity in charge site and intensity on the 2:1 layers of the original chlorites. However, the overall pattern is that of the transformation of high temperature chlorite to expanding clay minerals with high exchange capacities. Biotic processes appear to modify chlorites in a rather homogeneous manner compared to the formation of interstratified minerals common in the water-rock interaction pathway. These high charge expanding clays left after the biologically mediated reactions with chlorites are strong potential sites for cation (e.g., magnesium and potassium) capture and storage to supply the nutritional requirements of plants and organisms.     

Modeling biological invasions into periodically fragmented environments

Range expansion of a single species in a regularly striped environment is studied by using an extended Fisher model, in which the rates of diffusion and reproduction periodically fluctuate between favorable and unfavorable habitats. The model is analyzed for two initial conditions: the initial population density is concentrated on a straight line or at the origin. For each case, we derive a mathematical formula which characterizes the spatio-temporal pattern of range expansion. When initial distribution starts from a straight line, it evolves to a traveling periodic wave (TPW), whose frontal speed is analytically determinable. When the range starts from the origin, it tends to expand radially at a constant average speed in each direction (ray speed) keeping its frontal envelope in a similar shape. By examining the relation between the ray speed and the TPW speed, we derive the ray speed in a parametric form, from which the envelope of the expanding range can be predicted. Thus we analyze how the pattern and speed of the range expansion are affected by the pattern and scale of fragmentation, and the qualities of favorable and unfavorable habitats. The major results include: (1). The envelope of the expanding range show a variety of patterns, nearly circular, oval-like, spindle-like, depending on parameter values; (2). All these patterns are elongated in the direction of stripes; (3). When the scale of fragmentation is enlarged without changing the relative spatial pattern, the ray speed in any direction increases, i.e., the rate of range expansion increases.     

Multi-component model of intramural hematoma

A novel multi-component model is introduced for studying interaction between blood flow and deforming aortic wall with intramural hematoma (IMH). The aortic wall is simulated by a composite structure submodel representing material properties of the three main wall layers. The IMH is described by a poroelasticity submodel which takes into account both the pressure inside hematoma and its deformation. The submodel of the hematoma is fully coupled with the aortic submodel as well as with the submodel of the pulsatile blood flow. Model simulations are used to investigate the relation between the peak wall stress, hematoma thickness and permeability in patients of different age. The results indicate that an increase in hematoma thickness leads to larger wall stress, which is in agreement with clinical data. Further simulations demonstrate that a hematoma with smaller permeability results in larger wall stress, suggesting that blood coagulation in hematoma might increase its mechanical stability. This is in agreement with previous experimental observations of coagulation having a beneficial effect on the condition of a patient with the IMH.     

Chronic effects of Campylobacter infection

Campylobacter jejuni is one of the most common causes of bacterial gastroenteritis and chronic sequelae, such as reactive arthritis and Guillain-Barré syndrome (GBS), are known to follow uncomplicated infections. While little is known about reactive arthritis following Campylobacter infection, our knowledge on the pathogenesis of Campylobacter-induced GBS is expanding rapidly and is summarized in this review.     

Auricular endochondral pseudocysts: diagnosis and management

The auricle can be the site of a variety of cystic lesions, many of which involve either potential spaces between the auricular cartilage and the perichondrium or spaces within the skin and subcutaneous tissues. An auricular endochondral pseudocyst is a fluid collection located within the cartilaginous structure of the auricle. The auricular hematoma and the auricular pseudocyst may represent opposing ends of a continuum of damage and repair of traumatic insults. Whereas the hematoma represents a significant acute traumatic event resulting in cleavage between the perichondrium and the cartilage, the pseudocyst could be the outcome of chronic lower grade trauma. In this instance, the perichondrium not only separates from the cartilage but may be induced to regenerate an outer cartilaginous wall exacting the contour of the separated perichondrium, thus completing a cartilaginous auricular pseudocyst. This firm, cartilaginous outer cyst wall accounts for the increased difficulty in treating pseudocysts and clearly requires a different surgical treatment than for the hematoma. Having reviewed a substantial number of case reports, we recommend incision and drainage of the cavity followed by obliteration of the cavity by curettage, sclerosing agent, and pressure dressing. More invasive techniques should be reserved for an uncommon recurrence after adequate initial treatment.     

A REVIEW OF OPERATIONS ON THE TEMPORAL BONE

The majority of temporal bone operations are performed for treatment of acute or chronic middle ear and mastoid infection, otosclerosis and perforations of the tympanic membrane.Far from being a thing of the past, temporal bone surgery is an expanding field in the antibiotic age.Since treatment with antibiotics may temporarily allay the symptoms of serious disease of the ear, great care must be taken in examination of patients with a suspicious history.     

Moon Dust… Key to Cosmic Secrets

Students examine the bacterial expansion pattern and attempt to relate what they discover to expanding powers of two. They also relate what they see and discover to increasing living space requirements in a world of infinite space and finite space to discover that living space decreases as a function of one over expanding powers of two. The population doubling effect is also related to refuse generation and food supply requirements as well as human drinking requirements. During their investigations, students engage in a series of concrete activities to demonstrate the various effects of unabated population expansion.     

Testing the hypothesis of recent population expansions in nematode parasites of human-associated hosts

It has been predicted that parasites of human-associated organisms (eg humans, domestic pets, farm animals, agricultural and silvicultural plants) are more likely to show rapid recent population expansions than are parasites of other hosts. Here, we directly test the generality of this demographic prediction for species of parasitic nematodes that currently have mitochondrial sequence data available in the literature or the public-access genetic databases. Of the 23 host/parasite combinations analysed, there are seven human-associated parasite species with expanding populations and three without, and there are three non-human-associated parasite species with expanding populations and 10 without. This statistically significant pattern confirms the prediction. However, it is likely that the situation is more complicated than the simple hypothesis test suggests, and those species that do not fit the predicted general pattern provide interesting insights into other evolutionary processes that influence the historical population genetics of host-parasite relationships. These processes include the effects of postglacial migrations, evolutionary relationships and possibly life-history characteristics. Furthermore, the analysis highlights the limitations of this form of bioinformatic data-mining, in comparison to controlled experimental hypothesis tests.     

Tetragonisca guard bees interpret expanding and contracting patterns as unintended displacement in space

Guard bees of the stingless bee Tetragonisca angustula (Apidae: Meliponinae) hover in stable positions in front of the nest to protect the flight corridor leading to the nest entrance against insect intruders. To unravel the visual control of station keeping, we exposed these hovering guards to expanding and contracting patterns at the nest front. The bees fly away from an expanding pattern and towards the centre of a contracting pattern along a line connecting their initial position and the centre of expansion regardless of where in the visual field they view the pattern. The response of bees to a spinning radial pattern is different: they fly parallel to the pattern, up and down or forward and backward depending on whether they initially hover to the side, above or below the centre of rotation. The bees respond to horizontal and to vertical expansion and contraction. They also adjust their distance relative to a rotating spiral which produces a realistic flow field and thus allowed us to test to what extent the bees minimize image motion speed. We find that guard bees indeed move in the appropriate direction to minimize the image motion speed they experience. A comparison of bees hovering at different distances from the nestfront at the onset of pattern motion and experiencing very different image velocities shows that the dynamics of the reaction is quite uniform. At the pattern velocities tested, we did not find evidence that guard bees use image motion to control their flight speed. The bees' response rather suggests that the underlying mechanism might be insensitive to the size of motion vectors. Accepted: 2 April 1997     

Intravenous fluid administration may improve post-operative course of patients with chronic subdural hematoma: a retrospective study

Background

The treatment of chronic subdural hematoma (cSDH) is still charged of significant risk of hematoma recurrence. Patient-related predictors and the surgical procedures themselves have been addressed in many studies. In contrast, postoperative management has infrequently been subjected to detailed analysis. Moreover variable intravenous fluid administration (IFA) was not reported in literature till now in the context of cSDH treatment.

Methodology/Principal Findings

A total of 45 patients with cSDH were operated in our department via two burr hole craniostomy within one calendar year. Downward drainage was routinely left in hematoma cavity for a one day. Independent variables selected for the analysis were related to various aspects of patient management, including IFA. Two dependent variables were chosen as measure of clinical course: the rate of hematoma recurrence (RHR) and neurological status at discharge from hospital expressed in points of Glasgow Outcome Scale (GOS). Univariate and multivariate regression analyses were performed. Hematoma recurrence with subsequent evacuation occurred in 7 (15%) patients.Univariate regression analysis revealed that length of IFA after surgery influenced both dependent variables: RHR (p = 0.045) and GOS (p = 0.023). Multivariate regression performed by backward elimination method confirmed that IFA is a sole independent factor influencing RHR. Post hoc dichotomous division of patients revealed that those receiving at least 2000 ml/day over 3 day period revealed lower RHR than the group with less intensive IFA. (p = 0.031).

Conclusions/Significance

IFA has been found to be a sole factor influencing both: RHR and GOS. Based on those results we may recommend administration of at least 2000 ml per 3 days post-operatively to decrease the risk of hematoma recurrence.     

Leaf growth rate and nitrogen content determine respiratory costs during leaf expansion in grapevines

Respiration processes are well recognized as fundamental for the plant carbon balance, but little attention has been paid to the relationships among respiration rates, environment and genetic variability. This can be of particular interest to understand the differences in net carbon balances in crops as grapevines. Night respiration (R_n) and its associated growth (R_g) and maintenance (R_m) components were evaluated during leaf expansion in two grapevine cultivars (Tempranillo cv. and Garnacha cv.) that differ in their plant growth pattern and carbon balance. Simultaneously, leaf traits as leaf mass area, nitrogen (N) and carbon (C) content were evaluated in order to relate to the respiratory processes and the leaf growth. The results showed the differences in respiration rates associated with the leaf expansion pattern. Tempranillo developed leaves with higher leaf area and lower dry weight per leaf unit than Garnacha. Although differences between cultivars were observed in terms of growth costs in expanding leaves, the maintenance costs were similar for both cultivars. Also, a significant linear regression was found between respiration rates and N content in expanding and mature leaves. The results indicate that differences in structure and nitrogen content of expanding leaves may lead to respiratory differences between cultivars. These results also demonstrate the importance of respiratory cost components in carbon balance calculations in grapevines.     

Small Bowel Obstruction Due to Intramural Hematoma During Anticoagulant Therapy—A Non-Surgical Condition

Intramural hematoma of the small bowel should be suspected in any patient with signs or symptoms of small bowel obstruction who is having anticoagulant drug therapy, especially if it is longterm therapy and if the prothrombin time is excessively prolonged. A barium study is indicated and if the roentgen pattern is characteristic, conservative treatment is indicated. Unless there is an associated abdominal lesion requiring operation, most patients will improve in four to six days. Those not improving usually have other complicating conditions.     

Fine-scale genetic structure and marginal processes in an expanding population of Biscutella laevigata L. (Brassicaceae)

Evolutionary processes acting at the expanding margins of a species' range are still poorly understood. Genetic drift is considered prevalent in marginal populations, and the maintenance of genetic diversity during recolonization might seem puzzling. To investigate such processes, a fine-scale investigation of 219 individuals was performed within a population of Biscutella laevigata (Brassicaceae), located at the leading edge of its range. The survey used amplified fragment length polymorphisms (AFLPs). As commonly reported across the whole species distribution range, individual density and genetic diversity decreased along the local axis of recolonization of this expanding population, highlighting the enduring effect of the historical colonization on present-day diversity. The self-incompatibility system of the plant may have prevented local inbreeding in newly found patches and sustained genetic diversity by ensuring gene flow from established populations. Within the more continuously populated region, spatial analysis of genetic structure revealed restricted gene flow among individuals. The distribution of genotypes formed a mosaic of relatively homogenous patches within the continuous population. This pattern could be explained by a history of expansion by long-distance dispersal followed by fine-scale diffusion (that is, a stratified dispersal combination). The secondary contact among expanding patches apparently led to admixture among differentiated genotypes where they met (that is, a reshuffling effect). This type of dynamics could explain the maintenance of genetic diversity during recolonization.     

Retrobulbar hematoma and blepharoplasty

Retrobulbar hematoma leading to visual impairment is a rare but serious complication associated with elective blepharoplasty. A review of the literature addressing etiology, prevention, and management is presented. Removal of anterior orbital fat associated with traction and rupture of vessels within posterior orbital fat is currently most strongly supported as the cause of retrobulbar hematoma after blepharoplasty. Optic nerve ischemia is identified as the likely cause of visual impairment. Specific recommendations for avoidance and management of acute retrobulbar hematoma are offered. Recent background animal and human research is summarized.     

The vasculature and limb development

The developing vascular pattern of the embryonic chick limb results from a combination of two properties: the intrinsic self-assembly and branching properties of the vascular cells and the extrinsic information associated with the expanding mitotic population of mesenchymal cells; and the inhibitory factors which restrict the entrance of vessels into particular domains and/or decrease the branching frequency of such vessels. It is hypothesized that an important component of limb pattern formation is the interplay between the dividing population of mesenchymal cells and the intrinsic properties of the vascular cells. It is further asserted that the presence of particular vascular elements may, indeed, be 'positional information'. Two examples are cited involving aspects of limb duplication to support this possibility; it is suggested that vascular vessel size of a host limb may dictate the polarity of duplication events. The presented hypothesis emphasizes that the interplay between the intrinsic properties of self-assembly into tissues and extrinsic factors which establish boundaries and morphologies is involved in both vascular and limb pattern formation.     

The Recognition and Management of Peripheral Arterial Injuries

Early recognition of limb ischemia may allow prompt, effective therapy for peripheral arterial injuries. A review of cases of peripheral arterial trauma at the Toronto General Hospital since 1953 revealed that 50% of the injuries were not immediately recognized. An expanding hematoma, pulsatile hemorrhage or the onset of a bruit and thrill signifies arterial damage in penetrating wounds. Ischemia may be difficult to recognize in patients with soft tissue or skeletal trauma, but the presence of distal pallor, coolness, paresis, cyanosis, anesthesia, poor capillary refill and disproportionate pain indicates significant arterial damage and necessitates surgical exploration. The diagnosis of arterial “spasm” in such instances is untenable and can only be made after direct inspection, or on the return of pulses after reduction of a fracture or release of a tight cast. Restoration of arterial continuity by end-to-end anastomosis is the recommended technique for all arterial injuries, since after ligation of even minor vessels, ischemia may ensue, and amputation may occasionally be necessary.