Biomedical subjects

A Büttner

Publications and source records attributed to A Büttner.

At least 19 recordsLinked to original sources

PubMed2001

An immunohistochemical study of the dorsal capsule of the lumbar and thoracic facet joints.

STUDY DESIGN: The molecular composition of the extracellular matrix in the dorsal capsules of lumbar and thoracic facet joints was analyzed immunohistochemically. OBJECTIVES: To determine whether the immunohistochemical profile of the lumbar joint capsule suggests a role of the capsule in limiting axial rotation of the lumbar motion segment. SUMMARY OF BACKGROUND DATA: During axial rotation of the lumbar vertebrae, the axis of rotation shifts toward the facet joints in the direction of rotation. Thus, the capsule of the opposing joint should become tensed and wrap around the inferior articular process. Previous studies suggest that wrap-around ligaments are fibrocartilaginous. However, thoracic joint capsules are largely shielded from such loading and should be purely fibrous. METHODS: Dorsal capsules were removed from lumbar and thoracic facet joints of six adult cadavers. Specimens were immunolabeled with monoclonal antibodies for collagens, chondroitin, dermatan and keratan sulfates, versican, tenascin, aggrecan and link protein. Antibody binding was detected using the Vectastain ABC 'Elite' peroxidase kit (Vector Laboratories, Inc., Burlingame, CA). RESULTS: Both lumbar and thoracic joint capsules immunolabelled for most glycosaminoglycans and for Type I, III and VI collagens. However, labeling for Type II collagen, chondroitin-6-sulfate, aggrecan, and link protein was restricted to lumbar capsules. Such labeling was constantly seen at entheses and occasionally in the midsubstance. CONCLUSIONS: The molecular composition of the lumbar joint capsule suggests that it acts as a fibrocartilaginous, 'wrap-around' ligament that withstands compression in addition to tension during torsional movements of the lumbar spine. It wraps around the inferior articular process as rotation occurs and limits further movement.

Adult↗

PubMed2001

Sex determination and estimation of stature from the long bones of the arm.

The determination of sex and the estimation of stature from bones play an important role in identifying unknown bodies, parts of bodies or skeletal remains. In medico-legal practice statements on the probable sex of a decomposed body or part of a body are often expected even during autopsy. The present study was, therefore, restricted to few easily accessible dimensions from bones which were prepared only by mechanically removing soft tissues, tendons and ligaments. The specimens came from the Anatomical Institutes in Munich and Cologne from the years 1994-1998 including a total of 143 individuals (64 males and 79 females). The mean age was 79 years (46-108), the mean body height 161cm (134-189). The following measurements were taken: maximum humeral length (mean: 33.4cm in males; 30.7cm in females), vertical humeral head diameter (mean: 5.0cm in males, 4.4cm in females), humeral epicondylar width (mean: 6.6cm in males; 5.8cm in females), maximum ulnar length (mean: 26.5cm in males, 23.8cm in females), proximal ulnar width (mean: 3.4cm in males, 2.9cm in females), distal ulnar width (mean: 2.2cm in males; 1.8cm in females), maximum radial length (mean: 24.6cm in males; 22.0cm in females), radial head diameter (mean: 2.6cm in males, 2.2cm in females) and distal radial width (mean: 3.6cm in males; 3.2cm in females). The differences between the means in males and females were significant (P<0.0005). A discriminant analysis was carried out with good results. A percentage of 94.93% of cases were correctly classified when all measures of the radius were applied jointly, followed by humerus (93.15%) and ulna (90.58%). Applied singly, the humeral head diameter allowed the best distinction (90.41% correctly grouped cases), followed by the radial length (89.13%), the radial head diameter (88.57%) and the humeral epicondylar width (88.49%). The linear regression analysis for quantifying the correlation between the bone lengths and the stature led to unsatifactory results with large 95%-confidence intervals for the coefficients and high standard errors of estimate.

Adult↗

PubMed2001

Resistance of the lumbar spine against axial compression forces after implantation of three different posterior lumbar interbody cages.

BACKGROUND: The aim of using interbody fusion cages is to distract the degeneratively decreased disc height to decompress the neural structures in the intervertebral foramina and allow bony fusion. Prerequisite for a successful fusion therapy is a high resistance against subsidence and breakage. METHOD: Three types of implants, a cylindrical threaded titanium cage (Ray) (1c), a bullet shaped PEEK cage (Stryker) (1a) and a rectangular titanium cage with an endplate anchorage device (Marquardt) (1b) were implanted in eight monosegmental lumbar spine specimens (L 2/3 and L 4/5). Each specimen underwent a cyclic loading test with 40000 cycles at a rate of 5 Hz. A cyclic axial compression force ranging from 200 Newton [N] to 1000 N was applied and the axial translation recorded simultaneously to determine the subsidence tendency. After this procedure the specimens were tested with a progressive axial force until breakage. FINDINGS: There were only small differences in the subsidence tendency for the three cage designs. The height reduction due to cyclic loading ranged between 0.9 mm (Marquardt), 1.2 mm (Stryker) and 1.4 mm (Ray). The median break force ranged from 5486 N (Marquardt), 8359 N (Stryker) to 8413 N (Ray). No correlation between bone mineral density and failure load could be detected. INTERPRETATION: Endplate preparation and cage design of the tested implants do not seem to influence the resistance of the segment against cyclic axial compression. The compression with a continuously increasing load revealed that an implant-bone failure is not to be expected in physiological limits for all three cage types.

Biomechanical Phenomena↗

PubMed2001

Progressive idiopathic bilateral striato-pallido-dentate calcinosis (Fahr's disease) in a person with anabolic steroid abuse.

A 33-year-old male black student suddenly died during a basketball game. His previous medical history, including his neurological status, was unremarkable, but he was known to take anabolic steroids for several years. At autopsy, the cause of death was due to a fresh myocardial infarction. On neuropathological examination, there was extensive bilateral symmetrical calcification involving the basal ganglia as well as the dentate nuclei and the white matter of the cerebellum (Fahr's disease). A possible correlation between anabolic steroid-induced hypercalcemia and brain calcification is discussed.

Journal Article↗

PubMed2001

The diagnostic relevance of cerebral amyloid angiopathy in the setting of forensic pathology - a report of two cases and review of the literature.

The neuropathological features seen in two cases with cerebral amyloid angiopathy (CAA) are presented. An 85-year-old woman was found comatose at home and died on the way to the hospital. The cause of death was an intracerebral hemorrhage (ICH) in the right parietal lobe. A 93-year-old woman with a history of traumatic subarachnoid hemorrhage was operated on for a chronic subdural hematoma. Intraoperatively, she developed severe ICH and died. The cause of death was an ICH in the parieto-occipital lobe. The morphology of the vessels was studied on differently stained sections and the neuropathological findings of the surrounding brain tissue were investigated. The affected vessels showed the characteristic alterations seen in CAA and included vascular amyloid deposition, fibrinoid necrosis, double-barrel lumen, splitting of the internal elastic lamina, defects of the vessel wall, and microaneurysms. Visualization of beta-amyloid protein was performed by histological and immunohistochemical methods. The immunohistochemistry for beta-amyloid was more sensitive and yielded better results compared with Congo red. In cases of ICH, CAA has to be considered in the differential diagnosis. Besides the use of Congo red stain, the application of beta-amyloid immunohistochemistry is requested to reliably make the diagnosis of CAA. Additional staining with a modified silver impregnation technique (AgNOR) is useful to detect associated neurodegenerative changes.

Journal Article↗

PubMed2001

Primary meningeal sarcomas in two children.

Primary meningeal sarcomas are rare but highly aggressive tumors predominantly affecting children. The clinical course, imaging characteristics and histopathological features of meningeal sarcomas in two pediatric patients are presented. Furthermore, we critically discuss the new WHO classification of these entities comparing them to older descriptions. In a 6-year-old girl, a cranial computed tomography (CT) scan was performed, after a mild head trauma, showing a parieto-occipital hemorrhage. One month later, a circumscribed mass adhering to the meninges and with central areas of hemorrhage was evident on magnetic resonance imaging (MRI) scans. Brain biopsy revealed a polymorphocellular sarcoma originating from the leptomeninges and infiltrating the brain. In an 8-year-old girl, who presented with headaches and vomiting, several MRI-examinations were inconspicuous for nearly one year until the latest MR-scan revealed a diffuse contrast enhancement of the leptomeninges of the whole brain and spinal canal. After open biopsy, primary leptomeningeal sarcomatosis was diagnosed. Although CT and MRI did not allow a specific diagnosis in both cases the exact visualization of the extent of the tumor and/or meningeal involvement was possible. Since there are no specific imaging criteria to differentiate meningeal sarcoma from other solid brain tumors or from other tumoral or inflammatory meningioses brain biopsy is indispensable. In order to avoid misinterpretations and delays of therapy, early open brain biopsy or surgical resection of the lesion is necessary in cases of unclear brain masses, especially of unclear meningeal processes. Due to the low number of cases published so far, the biological behavior and clinical management of this tumor entity still awaits further investigation.

Child↗

PubMed2001

Fibrocartilage in the transverse ligament of the human acetabulum.

Biomechanical experiments on isolated hip joints have suggested that the transverse ligament acts as a bridle for the lunate articular surface of the acetabulum during load bearing, but there are inherent limitations in such studies because the specimens are fixed artificially to testing devices and there are no modifying influences of muscle pull. Further evidence is thus needed to substantiate the theory. Here we argue that if the horns of the lunate surface are forced apart under load, the ligament would straighten and become compressed against the femoral head. It would thus be expected to share some of the features of tendons and ligaments that wrap around bony pulleys and yet previous work has suggested that the transverse ligament is purely fibrous. Transverse ligaments were removed from 8 cadavers (aged 17-39 y) and fixed in 90% methanol. Cryosections were immunolabelled with antibodies against collagens (types I, II, III, VI), glycosaminoglycans (chondroitins 4 and 6 sulphate, dermatan sulphate, keratan sulphate) and proteoglycans (aggrecan, link protein, versican, tenascin). A small sesamoid fibrocartilage was consistently present in the centre of each transverse ligament, near its inner surface at the site where it faced the femoral head. Additionally, a more prominent enthesis fibrocartilage was found at both bony attachments. All fibrocartilage regions, in at least some specimens, labelled for type II collagen, chondroitin 6 sulphate, aggrecan and link protein, molecules more typically associated with articular cartilage. The results suggest that the ligament should be classed as containing a 'moderately cartilaginous' sesamoid fibrocartilage, adapted to withstanding compression. This supports the inferences that can be drawn from previous biomechanical studies. We cannot give any quantitative estimate of the levels of compression experienced. All that can be said is that the ligament occupies an intermediate position in the spectrum of fibrocartilaginous tissues. It is more cartilaginous than some wrap-around tendons at the wrist, but less cartilaginous than certain other wrap-around ligaments, e.g. the transverse ligament of the atlas.

Acetabulum↗

PubMed2001

Fibrocartilage at the entheses of the suprascapular (superior transverse scapular) ligament of man--a ligament spanning two regions of a single bone.

The suprascapular ligament converts the suprascapular notch into a foramen separating the vessels and nerve of the same name. It connects 2 regions of the same bone and does not cross any joint, and no mechanical function has yet been attributed to it. Nevertheless, variations in its thickness and length, and its tendency to ossify, suggest that the ligament responds to changes in mechanical load. This should be reflected in the composition of the extracellular matrix. The primary purpose of the present study is to demonstrate that the suprascapular ligament has fibrocartilaginous entheses (i.e. insertion sites), even though there is no obvious change in insertional angle that directly results from joint movement. Such a change is more typical of tendons or ligaments that cross highly mobile joints. The complete ligament (including both entheses) was removed from 7 cadavers shortly after death and fixed in 90% methanol. Cryosections were immunolabelled with a panel of monoclonal antibodies against collagens (types I, II, III, VI), glycosaminoglycans (chondroitin 4 sulphate, chondroitin 6 sulphate, dermatan sulphate and keratan sulphates), proteoglycans (aggrecan and versican) and link protein. Both entheses were strongly fibrocartilaginous, and a moderately fibrocartilaginous matrix was also detected throughout the remainder of the ligament. The extracellular matrix of both entheses labelled strongly for type II collagen, aggrecan and link protein. The fibrocartilaginous character of the entheses suggests that the insertion sites of the ligament are subject to both compressive and tensile loading and are regions of stress concentration. This in turn probably reflects the complex shape of the scapula and the presence of a conspicuous indentation (the suprascapular notch) near the ligament. The loading patterns may reflect either the attachment of muscles and/or the forces transmitted to the suprascapular ligament from the neighbouring coracoclavicular ligament.

Adult↗

PubMed2000

The neuropathology of heroin abuse.

A broad spectrum of neuropathologic changes are encountered in the brains of heroin abusers. The main findings are due to infections, either due to bacterial spread from bacterial endocarditis, mycoses, or from HIV-1 infection. Other complications include hypoxic-ischemic changes with cerebral edema, ischemic neuronal damage and neuronal loss, which are assumed to occur under conditions of prolonged heroin-induced respiratory depression, stroke due to, for example, thromboembolism, vasculitis, septic emboli, hypotension, and positional vascular compression. Myelopathy is believed to be the result of an isolated vascular accident within the spinal cord due to an as yet unknown mechanism. A distinct entity, spongiform leukoencephalopathy, has been described mainly after inhalation of pre-heated heroin. A lipophilic toxin-induced process was considered to be due to contaminants and to be induced or enhanced by cerebral hypoxia, but a definite toxin could not be identified. At the cellular level, abnormalities in signal transduction systems and changes of various receptor densities have been reported. The exact etiology of the different neuropathological alterations associated with heroin abuse is still unclear, but may also be related to additional substances used as adulterants.

Autopsy↗

PubMed2000

Determination of time-dependent skin temperature decrease rates in the case of abrupt changes of environmental temperature.

The present study deals with the development of a method for determining time-dependent temperature decrease rates and its application to postmortem surface cooling. The study concentrates on evaluating skin cooling behavior since data on skin cooling in the forensic literature are scarce. Furthermore, all heat transfer mechanisms strongly depend on the temperature gradient between body surface and environment. One of the main problems in modelling postmortem cooling processes is the dependence on the environmental temperature. All models for postmortem rectal cooling essentially presuppose a constant environmental temperature. In medico-legal practice, the temperature of the surrounding of a corpse mostly varies; therefore, an approach for extending the models to variable environmental temperatures is desirable. It consists in 'localizing' them to infinitesimal small intervals of time. An extended model differential equation is obtained and solved explicitly. The approach developed is applied to the single-exponential Newtonian model of surface cooling producing the following differential equation:T(S)'(t)=-lambda(t)(T(S)(t)-T(E)(t))(with T(S)(t) the surface/skin temperature, T(E)(t) the environmental temperature, lambda(t) the temperature decrease rate and T(S)'(t) the actual change of skin temperature or first-order derivative of T(S)). The differential equation directly provides an estimator:lambda(t)=-T(S)'(t)T(S)(t)-T(E)(t)for the time-dependent temperature decrease rate. The estimator is applied to two skin cooling experiments with different types of abrupt changes of environmental temperature, peak-like and step-like; the values of the time-dependent temperature decrease rate function were calculated. By reinserting them, the measured surface temperature curve could be accurately reconstructed, indicating that the extended model is well suited for describing surface cooling in the case of abrupt changes of environmental temperature.

Autopsy↗

PubMed2000

Histologically repeatedly confirmed gliosarcoma with long survival: review of the literature and report of a case.

OBJECTIVE AND IMPORTANCE: A rare case of gliosarcoma in a 61-year-old woman is presented with a stable situation over 22 years with an excellent quality of life. CLINICAL PRESENTATION: The patient was initially symptomatic and was operated on in 1975 for a deep-seated left parietal gliosarcoma. During the following 20 years, she was clinically asymptomatic until she complained of increasing headache in 1995. Neuroradiological imaging showed a sharply demarcated lesion on MRI at the former operative site, which was operated on again. Four months later, the residual tumour did grow again. INTERVENTION: As radiation therapy could not stop tumour progression and the neurological status worsened, the patient was operated on again for a massive tumour mass in the left parieto-occipital region, filling out nearly all of the previous resection cavity. Despite radio-immunotherapy, the patient finally died 22 years after the first discovery of the tumour. CONCLUSION: The present case shows that, in rare instances, gliosarcomas may show prolonged survival, although the underlying pathogenetic mechanisms for this clinical behaviour are not understood.

Brain Neoplasms↗

PubMed2000

Lisch corneal dystrophy is genetically distinct from Meesmann corneal dystrophy and maps to xp22.3.

PURPOSE: There is an ongoing discussion whether Lisch corneal dystrophy (band-shaped and whorled microcystic dystrophy of the corneal epithelium) represents a disorder that is different from Meesmann corneal dystrophy. The purpose of this study was to evaluate at the molecular level if Lisch and Meesmann corneal dystrophies are genetically distinct. METHODS: We examined at the slit lamp a total of 48 members of a family with an aggregation of Lisch corneal dystrophy. Genomic DNA was extracted from leukocytes of the peripheral blood of seven affected and six unaffected members of this family. Mutational hotspots in the cornea-specific keratin genes K3 and K12 were scanned for mutations by single-strand conformation analysis. To test for linkage to the keratin K3 or K12 loci or for X-chromosomal inheritance, six (K3) and four (K12) microsatellite markers each flanking the keratin loci as well as 22 microsatellite markers covering the X-chromosome were typed. Linkage was analyzed using the MLINK and FASTMAP procedures. RESULTS: A total of 19 trait carriers were identified in six generations of the family. No hereditary transmission from father to son was observed. Linkage was excluded for the keratin K3 and K12 genes. Furthermore, single-strand conformation analysis detected no mutations in these genes. Multipoint linkage analysis revealed linkage with a maximum likelihood of the odds (LOD) score of 2.93 at Xp22.3. Linkage was excluded for Xp22.2 to Xqter. CONCLUSIONS: Lisch corneal dystrophy is genetically different from Meesmann corneal dystrophy. Evidence was found for linkage of the gene for Lisch corneal dystrophy to Xp22.3.

Adolescent↗

PubMed2000

[The driving simulation test "carsim" for assessing vigilance. Effect of driving practice and other factors in health subjects and in patients with sleep apnea syndrome].

Among other factors, obstructive sleep apnoea (OSAS) patients suffer from impaired continuous attention. For registration and objectification as well as observation of the course of therapy, driving simulation programmes are particularly suitable. "Carsim", a driving simulation newly developed by us, simulates a bendy road via a screen where a vehicle is supposed to be kept on the right lane by operating a steering wheel. Apart from examination of quality criteria (objectivity, reliability, validity) and establishment of standard values, the influence of significant variables (age, gender, school education, profession, duration of disorder, AHI, BMI, visual and motor functionability, driving license, driving experience, Epworth score, accident frequency) on patients and healthy controls requires to be evaluated. For this purpose, 100 healthy controls, 200 OSAS patients and 30 patients under nCPAP were analysed. In healthy persons and patients under nCPAP, driving experience had no impact on the driving simulation results. OSAS patients with no driving license and no driving experience achieved lower marks for tracking than patients with driving license or a lot of driving experience (no driving license: x = 8058 +/- 10,878 track deviations; with driving licence: x = 2111 +/- 6564 track deviations; p < .001). According to our findings, untreated OSAS severely interferes with patients' attention capacity as well as their coping strategies.

Arousal↗

PubMed2000

Preliminary report: monocular spatial localization in children with strabismic amblyopia.

Defective spatial localization is an important feature of strabismic amblyopia. Based on our experience from testing adult strabismics under various test conditions, we developed a test for assessing vertical alignment in strabismic children. Patients had to align a vertical test line with the apices of two vertically arranged reference triangles, under the control of both the dominant eye and the amblyopic eye. Means and standard deviations of several judgements represent systematic errors and uncertainty of alignment. We tested 27 strabismic and 34 age-matched control children aged 4.5-10 years. Control children showed a scatter of mean systematic alignment around the correct position of up to 7 minarc. In the amblyopic eyes of strabismic children, uncertainty was consistently higher than in the eyes of the control children. Systematic errors outside the normal range frequently occurred. In children tested repeatedly during occlusion therapy, uncertainty decreased as visual acuity improved. In several cases we observed changes of systematic vertical alignment during therapy, sometimes unexpectedly in the sense of a change in the direction of mislocalization or an initial increase and later decrease of errors. Thus, children with strabismic amblyopia show spatial localization deficits which are similar to those of adult strabismic amblyopes. Both spatial uncertainty and systematic distortions are susceptible to change due to enforced use of the amblyopic eye during occlusion therapy.

Amblyopia↗

PubMed1999

Sudden natural death 'at the wheel': a retrospective study over a 15-year time period (1982-1996).

In order to investigate the incidence and implications of sudden natural death at the wheel, a retrospective study was carried out over a 15-year time period ranging from 1982 until 1996. During this time period 147 drivers of motor vehicles were found out of 34,554 cases examined at the Institute of Legal Medicine, Ludwig-Maximilians University, Munich, Germany. There were 13 females and 134 males and the mean age was 56.8 years (range 20-86 years). The main cause of death was ischemic heart disease which was found in 113 cases. There were mainly minor injuries to the driver, or to other passengers, or to other road users and only minor property damage. Our study confirms previous investigations that sudden natural death at the wheel is a rare event in proportion to unnatural death at the wheel and is not a substantial threat to other road users. Despite existing guidelines for granting a driving licence, medical screening to exclude high risk patients from driving cannot prevent the occurrence of sudden natural death at the wheel.

Accidents, Traffic↗

PubMed1999

Unexpected death in persons with symptomatic epilepsy due to glial brain tumors: a report of two cases and review of the literature.

Two cases of unexpected death in persons with epileptic seizures due to a brain tumor are presented which encompassed an astrocytoma WHO grade II and an anaplastic astrocytoma WHO grade III. A 35-year-old man was found somnolent and disoriented at home. A computed tomography (CT) scan revealed a tumor of the right frontal lobe suggestive for an oligodendroglioma. During an angiographic examination the patient experienced an epileptic seizure. Some weeks later, the man was found dead in front of his house with a fresh bite mark of the tongue. Neuropathological examination revealed an astrocytoma WHO grade II of the right frontal lobe. A 47-year-old man plunged into a swimming-pool and was found submerged some minutes later. After resuscitation he survived comatose for 8 days but finally died due to severe hypoxic brain damage. He had been operated on a brain tumor of the temporal lobe 1 year before the accident. Neuropathological examination revealed residual tumor tissue at the operation site corresponding to an anaplastic astrocytoma WHO grade III. Although rare, death in persons with epileptic seizures due to brain tumors is an important mechanism of death encountered by the forensic pathologist.

Adult↗

PubMed1999

Energy loss due to radiation in postmortem cooling. Part B: Energy balance with respect to radiation.

With the help of the law of Stefan and Boltzmann and a model for the cooling of exposed skin derived from the data of Lyle and Cleveland, the radiation energy loss ER can be calculated according to the following formula: [formula in text] where epsilon represents the emissivity of the skin (0.98), sigma the Stefan-Boltzmann constant, AR the radiating surface area, TS(0) the skin temperature at death, TE the environmental temperature and Z' = 0.1017 the gradient of the skin temperature curve. Additionally, an energy loss due to conduction and convection EC has to be taken into account. Comparing the energy losses due to radiation, conduction and convection with the decrease ET of the thermal energy in the body, calculated from mean heat capacity (3.45 kJ/(kg degrees K)), body mass and decrease of mean body temperature, there is a surplus of energy in the very early postmortem period, which can be explained only by an internal source of energy EI. Alltogether the following balance equation can be formulated: ET + EI = ER + EC Since the body temperature decreases in the early postmortem period, EI can be estimated by: EI(t) > or = max (ER(t) - ET(t), 0). The values obtained range up to 500 kJ for a medium sized (175 cm), medium weight (75 kg) body at an environmental temperature of 5 degrees C and are compatible with estimations of Lundquist for supravital energy production by breakdown of glycogen.

Body Mass Index↗

PubMed1999

Non-lymphomatous brain tumors in HIV-1 infection: a review.

A broad spectrum of malignant tumors affecting various organ systems in HIV-1 infected patients have been described in larger series. Intracerebral mass lesions encountered in HIV-1 infection are mostly due to toxoplasmosis and central nervous system (CNS) lymphoma. Brain tumors (excluding lymphomas) occurring in HIV-1 infected patients have only occasionally been described. The present review summarizes these diverse tumor entities and reports on the controversial theories of a possible oncogenic potential of HIV-1. Although rare, intracerebral tumors must be considered in the differential diagnosis of an intracranial space-occupying lesion in an HIV-1 infected patient.

Brain Neoplasms↗