Pure apraxic agraphia: a disconnection syndrome after left subcortical stroke.
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Aged↗
Biomedical subjects
A Buss
Publications and source records attributed to A Buss.
Sequential loss of myelin proteins during Wallerian degeneration in the human spinal cord.
Axons undergo Wallerian degeneration (WD) distal to a point of injury. In the lesioned PNS, WD may be followed by successful axonal regeneration and functional recovery. However, in the lesioned mammalian CNS, there is no significant axonal regeneration. Myelin-associated proteins (MAPs) have been shown to play significant roles in preventing axonal regeneration in the CNS. Since relatively little is known about such events in human CNS pathologies, we performed an immunohistochemical investigation on the temporal changes of four MAPs during WD in post-mortem spinal cords of 22 patients who died 2 days to 30 years after either cerebral infarction or traumatic spinal cord injury. In contrast to experimental studies in rats, the loss of myelin sheaths is greatly delayed in humans and continues slowly over a number of years. However, in agreement with animal data, a sequential loss of myelin proteins was found which was dependent on their location within the myelin sheath. Myelin proteins situated on the peri-axonal membrane were the first to be lost, the time course correlating with the loss of axonal markers. Proteins located within compact myelin or on the outer myelin membrane were still detectable 3 years after injury in degenerating fibre tracts, long after the disappearance of the corresponding axons. The persistence of axon growth-inhibitory proteins such as NOGO-A in degenerating nerve fibre tracts may contribute to the maintenance of an environment that is hostile to axon regeneration, long after the initial injury. The present data highlight the importance of correlating the well documented, lesion-induced changes that take place in controlled laboratory investigations with those that take place in the clinical domain.
Adolescent↗
Expression pattern of NOGO-A protein in the human nervous system.
The distribution pattern of NOGO-A protein, an important axon growth inhibitory molecule and member of the reticulon family, has been investigated in the adult human brain, spinal cord, retina and dorsal root ganglia. Intense NOGO-A immunoreactivity was detected in oligodendroglial cell bodies and their myelin sheaths in nerve fibre tracts of the central nervous system. Furthermore, numerous populations of neurons in the brain and spinal cord expressed NOGO-A to a variable extent in their cell bodies and neurites, suggesting additional, as-yet-unknown, functions of this protein.
Adult↗
[Diagnosis of an initial infratentorial central nervous system B-cell lymphoma during prolonged cortisone medication].
We present a patient with primary central nervous system B-cell lymphoma. He had suffered from slowly developing weight loss and presented to us with disorientation, seizures, and a supranuclear gaze disturbance. The patient was dismissed with the primary diagnosis of autoimmune encephalitis of the brainstem and put on oral corticosteroids. Four months later, his health status had deteriorated, and at that time diagnostic methods pointed to a cerebral lymphoma. Stereotactic biopsy with subsequent immunohistochemistry and polymerase chain reaction analysis revealed a highly malignant B-cell lymphoma of the CNS, despite prolonged corticosteroid treatment. The patient was treated with whole brain radiotherapy.
Adrenal Cortex Hormones↗
Gradual loss of myelin and formation of an astrocytic scar during Wallerian degeneration in the human spinal cord.
Axons undergo Wallerian degeneration distal to a point of injury. Experimental investigations have documented many of the cellular and molecular events that underlie this behaviour. Since relatively little is known about such events in human CNS pathologies and current experimental intervention strategies indicate the possibility of significant axon regeneration along the original degenerated fibre tract, we performed an immunohistochemical investigation of the dynamics of Wallerian degeneration in post mortem spinal cords of patients who died 2 days to 30 years after either cerebral infarction or traumatic spinal cord injury. Neurofilament (NF) staining demonstrated a spatio-temporal pattern of axonal loss within degenerating descending nerve fibre tracts that could be detected close to the lesion as early as 12 days after injury and progressed to an almost complete loss of NF immunoreactivity at survival times of 1 year and longer. Immunohistochemistry for glial fibrillary acidic protein revealed a late astrocytic reaction starting at 4 months after injury in the degenerating tracts, leading to the long-term deposition of a dense astrocytic scar. These events were accompanied by the gradual reduction of myelin basic protein in affected nerve fibre tracts, leading to almost complete loss by 3 years after injury. Since the extracellular matrix molecule chondroitin sulphate proteoglycan (CSPG) is known to be strongly inhibitory for axonal regeneration and to be a major component of gliotic scar tissues, we investigated the possible deposition of CSPG within the degenerating nerve fibre tracts. Apart from a local up-regulation close to the lesion site, our results show no enhanced CSPG expression within degenerated tracts at any survival time. This suggests that despite the apparent lack of CSPG in Wallerian degeneration, the slow reduction of CNS myelin and the long-term deposition of a dense astrocytic scar may present an environment that is non-supportive for axon regrowth.
Adult↗
Does loperamide affect motor activity after proctocolectomy and ileal pouch-anal anastomosis? An experimental study in dogs.
This study investigated the effect of loperamide on the motor function of small intestine and J-pouch. Proctocolectomy and ileal pouch-anal anastomosis were performed in four dogs. Motility was recorded by serosal electrodes and strain gauge transducers. The intestinal transit time was determined radiologically. Multiple measurements were performed before and during chronic administration of loperamide. This treatment led to a significant decrease in median stool frequency from 11 (10-13) to 9 stools/day (8-12) and a tendential increase in intestinal transit time from 60 (50-105) to 70 min (60-90). This was not accompanied by significant changes in fasted or postprandial motility. There were no significant differences in the characteristics of the migrating myoelectric complex or in the fed pattern, either in the small intestine or in the pouch. Loperamide thus does not significantly affect intestinal motility after ileal pouch-anal anastomosis. The reduction in stool frequency seems to be due to antisecretory effects in the first line.
Animals↗
Major histocompatibility complex class II expression by activated microglia caudal to lesions of descending tracts in the human spinal cord is not associated with a T cell response.
Lesion-induced microglial/macrophage responses were investigated in post-mortem human spinal cord tissue of 20 patients who had died at a range of survival times after spinal trauma or brain infarction. Caudal to the spinal cord injury or brain infarction, a strong increase in the number of activated microglial cells was observed within the denervated intermediate grey matter and ventral horn of patients who died shortly after the insult (4-14 days). These cells were positive for the leucocyte common antigen (LCA) and for the major histocompatibility complex class II antigen (MHC II), with only a small proportion staining for the CD68 antigen. After longer survival times (1-4 months), MHC II-immunoreactivity (MHC II-IR) was clearly reduced in the grey matter but abundant in the white matter, specifically within the degenerating corticospinal tract, co-localising with CD68. In this fibre tract, elevated MHC II-IR and CD68-IR were still detectable 1 year after trauma or stroke. It is likely that the subsequent expression of CD68 on MHC II-positive microglia reflects the conversion to a macrophage phenotype, when cells are phagocytosing degenerating presynaptic terminals in grey matter target regions at early survival times and removing axonal and myelin debris in descending tracts at later survival times. No T or B cell invasion or involvement of co-stimulatory B7 molecules (CD80 and CD86) was observed. It is possible that the up-regulation of MHC II on microglia that lack the expression of B7 molecules may be responsible for the prevention of a T cell response, thus protecting the spinal cord from secondary tissue damage.
Aged↗
Myoelectric and motor activity after proctocolectomy and ileal pouch-anal anastomosis in dogs.
BACKGROUND: The aim of this study was to investigate the motor function of the ileoanal pouch and to evaluate its coordination with proximal small-intestine motility. METHODS: Proctocolectomy and ileal J pouch-anal anastomosis were performed in 12 dogs. Motility was recorded by serosal electrodes and strain gauge transducers. RESULTS: Transmission of the migrating motor complex (MMC) on the pouch appeared in only 37 of 109 measurements. On the ascending limb there was a constant irregular activity with no MMC detectable. Motility pattern of the pouch did not change postprandially. Spontaneous defecation always appeared independently from MMC transmission without an increase of electrical or mechanical activity or endoluminal pouch pressure. CONCLUSIONS: Ileal pouch motility is independent from motility patterns of the proximal intestine. Its random contractile activity might provide storage function and make the pouch act as a functional reservoir. Intrinsic pouch motility is not responsible for pouch evacuation under physiologic conditions.
Animals↗
The concept of adequate causation and Max Weber's comparative sociology of religion.
Max Weber's The Protestant Ethic and the Spirit of Capitalism, studied in isolation, shows mainly an elective affinity or an adequacy on the level of meaning between the Protestant ethic and the 'spirit' of capitalism. Here it is suggested that Weber's subsequent essays on 'The Economic Ethics of World Religions' are the result of his opinion that adequacy on the level of meaning needs and can be verified by causal adequacy. After some introductory remarks, particularly on elective affinity, the paper tries to develop the concept of adequate causation and the related concept of objective possibility on the basis of the work of v. Kries on whom Weber heavily relied. In the second part, this concept is used to show how the study of the economic ethics of India, China, Rome and orthodox Russia can support the thesis that the 'spirit' of capitalism, although it may not have been caused by the Protestant ethic, was perhaps adequately caused by it.
Capitalism↗
Dynamics of microglial activation in the spinal cord after cerebral infarction are revealed by expression of MHC class II antigen.
Microglial reactivity associated with induction of MHC class II (HLA-DR) antigen is a sensitive indicator for pathological events in the CNS. To assess the response of glial cells after lesions of supraspinal descending tracts, HLA-DR, CD68 and GFAP were studied immunohistochemically on spinal cord tissue of 5 patients who died after unilateral infarction of the middle cerebral artery territory, and 5 control cases. In patients who died shortly after a stroke (4-14 days) increased HLA-DR-immunoreactivity (HLA-DR-IR) could be observed in the intermediate grey matter and in the ventral horn. The CD68-IR was much less intense. After longer survival times (5 weeks to 4 months). HLA-DR-IR in the grey matter was clearly lower than that observed in the spinal cord of short survival times, but very abundant in the dorsolateral funiculus, specifically within the corticospinal tract. In white matter areas, CD68-IR was almost identical to the HLA-DR-IR. Within the grey matter, CD68-IR was similar to the control tissue. A moderate increase of GFAP-positive astrocytes could be seen only in the grey matter after longer survival times. It seems probable, that the dynamics of HLA-DR-positive microglia reflect the early phagocytosis of presynaptic terminals by microglia in target regions of descending fibre tracts. In the white matter, the removal of degenerating axons by phagocytosing microglia expressing HLA-DR and CD68 antigens is a slower process which occurs over a period of months.
Adult↗
Tuberous breast: a new approach.
The authors make a historical summary of the pathologic condition of tuberous breast and describe a new procedure for its correction. The method involves a periareolar approach, dividing the breast in two portions to disrupt the constricting ring, and making an inferiorly based flap or pedicle, as described and used by the senior author since 1969, with publication in 1973. The main goal is to correct the deformity at a one-stage operation, resulting in a periareolar scar only, without the use of alloplastic elements such as prostheses, mesh, or tissue expanders. The authors emphasize that Brazilian patients prefer having small breasts rather than large ones, even though the procedure allows the implantation of pre- or retromuscular implants through the periareolar incision.
Breast↗
A new electrohydraulic energy converter for a left ventricular assist device.
An energy converting system that can function for years without maintenance is required for the drive of a left ventricular assist device (LVAD). To meet the requirements of safety, the energy converter should have a simple design with few moving elements. The design applied herein has only one moving part and thus has greater inherent safety than competing systems. The only moving part is the rotor unit, comprised of the impeller of a centrifugal pump, the rotor of an electric motor, and the rotor of an electric axial actuator. A reversal of flow of the transmitter fluid can be achieved with an axial shift of this rotor unit. This fluid acts on the outer surface of a blood chamber and enables it to draw in blood and to expel it. Valves direct the flow of blood. The energy converter performs a flow of 12 L/min at a motor speed of 6,000 rpm against a pressure head of 115 mm Hg according to an output of the pulsatile blood pump of 5 L/min.
Electric Power Supplies↗
Firing a weapon and aggression.
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Aggression↗
Midiabdominoplasty: indications and technique.
In the treatment of aesthetic deformities of the abdomen there are three points we should analyze: the skin, the fat tissue, and the muscles. Based on these points we can classify it into six groups. Midiabdominoplasty is indicated in the correction of deformities of groups 2, 3, and 4. A small fusiform resection of skin is done in the lower abdomen, undermining of the skin up to the umbilicus (or to the xiphoid appendix if necessary to treat diastasis of the rectus muscles in the supraumbilical region), and desinsertion of the umbilicus, with no external scar, are the main points in this technique. The main complication was the formation of seroma. No necrosis of the flap or unsightly scars were observed. The results were good, with the patients satisfied with their new abdomens.
Abdomen↗
Acute onset of hemorrhagic leukoencephalomyelitis (Hurst) in the spinal cord.
Acute hemorrhagic leukoencephalomyelitis is considered to be a rare autoimmune disorder. The present case, a 34-year-old male, developed non-specific symptoms 3 weeks after surgical removal of his meniscus and following an inconspicuous infection of the upper respiratory tract. The spinal cord was the first to be affected, followed by symptoms of headache, nausea and fever which reached 39.4 degrees C. Autopsy revealed acute hemorrhagic leukoencephalomyelitis with marked involvement of the spinal cord. Diagnosis was established by histopathological examination of the brain and spinal cord. This is the first description of the onset of this disease in the spinal cord.
Adult↗