Publications by authors named "Dietrich W"

Previous cerebral ischemia studies have reported the limitations of restricted periods of postischemic hypothermia in producing long-term neuroprotection. The present experiment attempts to determine whether delayed treatment with the free radical scavenger N-tert-butyl-a-phenylnitrone (PBN) is protective at 2 months following transient global forebrain ischemia, and whether additive effects can be observed when PBN is administered in combination with moderate hypothermia. For this aim rats were subjected to 10 min of two-vessel forebrain ischemia followed by (a) 3 h of postischemic normothermia (37 degrees C); (b) 3 h of postischemic hypothermia (30 degrees C); (c) normothermic procedures combined with delayed injections of PBN (100 mg/kg) on days 3, 5 and 7 post-insult; (d) postischemic hypothermia combined with delayed PBN treatment; or (e) sham procedures.

View Article and Find Full Text PDF

We tested the hypothesis that a transient non-lethal ischemic insult lasting 2 min would protect against subsequent moderate traumatic brain injury. Sprague-Dawley rats were randomized into three experimental groups, including sham ischemia procedures and ischemic preconditioning (IPC) followed 48 h later by moderate traumatic brain injury (TBI) provoked by parasagittal fluid percussion injury (1.8-2.

View Article and Find Full Text PDF

Previous work in this laboratory has demonstrated that rats show substantial deficits on the cued and hidden versions of the Morris water maze, as well as an apparent time-dependent recovery over a period of months, following moderate parasagittal fluid-percussion (FP) injury. However, the longitudinal nature of those studies precluded definitive statements regarding recovery because of the possible confound of practice-dependent improvements in performance. The present experiments were undertaken to address this issue and to investigate more closely the relationship between impact severity and posttraumatic learning/memory deficits, which have not been examined thoroughly in this model.

View Article and Find Full Text PDF

In these studies, we examined the neuroprotective effects of the potent antiinflammatory cytokine interleukin-10 (IL-10) following spinal cord injury (SCI). Neuroprotection was assessed by using behavioral and morphological end points. We hypothesized that injury-induced inflammation contributes to the resulting neuropathology and subsequent loss of function.

View Article and Find Full Text PDF

We report on a 57-year-old male presenting with radicular pain in the nerve roots of L5 and S1 on the right side and dysuria. Magnetic resonance imaging (MRI) of the lumbar spine showed multiple (up to 20) small, intradural enhancing nodules attached to the cauda equina down to the sacrum, the largest 1 cm in diameter at the level Th12/L1 compressing the conus. Additionally, small nodules in the cervico-thoracal region adjacent to the cord, but no cerebellar or cerebral abnormalities, were detected in a consecutive MRI of the remaining neuroaxis.

View Article and Find Full Text PDF

The authors describe the case of a 15-year-old boy who underwent resection of a large left temporal tumor. During a normal postoperative course, computerized tomography (CT) scanning demonstrated a spherically hyperdense structure near the internal carotid artery, enlarging on a control CT scan. A suspected false aneurysm was confirmed on magnetic resonance imaging; angiographic studies were negative.

View Article and Find Full Text PDF

Object: Patients with head injuries often experience respiratory distress that results in a secondary hypoxic insult. The present experiment was designed to assess the histopathological consequences of a secondary hypoxic insult by using an established rodent model of traumatic brain injury (TBI).

Methods: Intubated anesthetized rats were subjected to moderate (1.

View Article and Find Full Text PDF

Objective: Reactive oxygen species are thought to participate in the pathobiology of traumatic brain injury (TBI). This study determined whether treatment with LY341122, a potent inhibitor of lipid peroxidation and an antioxidant, would provide neuroprotection in a rat model of TBI.

Methods: To investigate the efficacy of LY341122 in this parasagittal fluid percussion model (1.

View Article and Find Full Text PDF

Human chromosome 5q11.2-q13.3 and its ortholog on mouse chromosome 13 contain candidate genes for an inherited human neurodegenerative disorder called spinal muscular atrophy (SMA) and for an inherited mouse susceptibility to infection with Legionella pneumophila (Lgn1).

View Article and Find Full Text PDF

Recently, the human orthologue to the cell cycle checkpoint genes rad17 (Schizosaccharomyces pombe) and RAD24 (Saccharomyces cerevisiae), called HRAD17, has been isolated and localized to chromosome 4. Independently, we have isolated the HRAD17 transcript and mapped it to chromosome 5q13 between the CCNB1 and BTF2p44cen genes. Furthermore, we have identified the complete exon-intron structure of HRAD17.

View Article and Find Full Text PDF

Abnormalities in cerebrovascular reactivity or hemodynamic reserve are risk factors for stroke. The authors determined whether hemodynamic reserve is reduced in an experimental model of thromboembolic stroke. Nonocclusive common carotid artery thrombosis (CCAT) was produced in rats by a rose bengal-mediated photochemical insult, and moderate hypotension (60 mm Hg/30 min) was induced 1 hour later by hemorrhage.

View Article and Find Full Text PDF

This study documents the regional and temporal patterns of glial fibrillary acidic protein (GFAP) RNA and protein expression after parasagittal fluid-percussion (F-P) brain injury (1.7 to 2.2 atm) in male Sprague-Dawley rats.

View Article and Find Full Text PDF

A physical map of the mouse genome is an essential tool for both positional cloning and genomic sequencing in this key model system for biomedical research. Indeed, the construction of a mouse physical map with markers spaced at an average interval of 300 kb is one of the stated goals of the Human Genome Project. Here we report the results of a project at the Whitehead Institute/MIT Center for Genome Research to construct such a physical map of the mouse.

View Article and Find Full Text PDF

Although most visual pathway tumors are low-grade gliomas their biologic behavior is highly unpredictable. In order to determine whether assessment of proliferative activity can assist in predicting tumor behavior, we studied the MIB-1 labeling indices (MIB-1 LIs) in surgical specimens and monitored tumor growth in 31 consecutive children operated on between 1978 and 1997. The MIB-1 LIs at diagnosis varied from 0-10.

View Article and Find Full Text PDF

Experimental studies have demonstrated that postischemic therapeutic interventions may delay rather than provide long-lasting neuroprotection. The purpose of this study was to determine whether mild hypothermia (33-34 degrees C) combined with the anti-inflammatory cytokine interleukin-10 (IL-10) would protect the CA1 hippocampus 2 months after ischemia. Rats were subjected to 12.

View Article and Find Full Text PDF

Traumatic brain injury can induce the expression of stress-related and neurotrophic genes both within the injury site and in distant regions. These genes may affect severity of damage and/or be neuroprotective. We used in situ hybridization to assess the alterations in expression of the heat shock protein HSP70, nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF) genes in rat brain following moderate fluid-percussion (F-P) injury at various survival times.

View Article and Find Full Text PDF

Determination of the urinary excretion of sucrose after an oral dose has been used as a noninvasive test to measure gastric permeability in several clinical studies. Regarding different contact times of sucrose solution within the gastric mucosa, the present study investigates a possible influence of the gastric emptying rate on the sucrose permeability test. Urinary sucrose excretion and the gastric emptying rate of liquids using 13C-acetate breath test were determined in twelve healthy volunteers.

View Article and Find Full Text PDF

Cytokines and neurotrophic factors have been implicated in the pathophysiology of injury to the central nervous system. While some cytokines are considered pro-inflammatory, other factors promote neuronal growth and survival. The present study investigated the neuroprotective effects of interleukins 1 (IL-1), 4 (IL-4), and 6 (IL-6), nerve growth factor (NGF), ciliary neurotrophic factor (CNTF), and basic fibroblast growth factor (bFGF) in a contusion model of spinal cord injury.

View Article and Find Full Text PDF

Phytochelatins (PCs), a family of heavy metal-inducible peptides important in the detoxification of heavy metals, have been identified in plants and some microorganisms, including Schizosaccharomyces pombe, but not in animals. PCs are synthesized enzymatically from glutathione (GSH) by PC synthase in the presence of heavy metal ions. In Arabidopsis, the CAD1 gene, identified by using Cd-sensitive, PC-deficient cad1 mutants, has been proposed to encode PC synthase.

View Article and Find Full Text PDF

Previous studies indicated preconditioning of the brain with sublethal ischemic insults separated by many hours, protected tissues from a subsequent lethal insult. We recently reported neuroprotection by a rapid preconditioning paradigm where a sublethal ischemic insult preceded test ischemia by only 30 min. We hypothesize that neuroprotection caused by the rapid ischemic preconditioning (IPC) will result in lowered microglial, reactive astrocytes and increased normal neuronal cell counts.

View Article and Find Full Text PDF

We investigated the effects of therapeutic hypothermia (30 degrees C) on alterations in constitutive (cNOS) and inducible (iNOS) nitric oxide synthase activities following traumatic brain injury (TBI). Male Sprague-Dawley rats were anesthetized with 0.5% halothane and underwent moderate (1.

View Article and Find Full Text PDF

Objective: To analyze the influence of extracerebral organ system dysfunction after aneurysmal subarachnoid hemorrhage (SAH) on mortality and neurologic outcome.

Design: Observational study with retrospective data extraction.

Setting: Neurosurgical intensive care unit (NICU) at a primary level university hospital, supervised and staffed by both members of the Clinic of Neurosurgery and the Clinic of Anesthesiology and General Intensive Care.

View Article and Find Full Text PDF

Traumatic brain injury (TBI) produces transient increases in constitutive nitric oxide synthase (cNOS) activity and prolonged behavioral abnormalities. This study investigated the effects of nitro-L-arginine-methyl ester (L-NAME) and 3-bromo-7-nitroindazole (7-NI) treatment on cNOS catalytic activity and sensorimotor behavioral outcome after TBI. Rats underwent moderate (1.

View Article and Find Full Text PDF

Background And Purpose: Transient distal platelet accumulation after common carotid artery thrombosis (CCAT) leads to hemodynamic, metabolic, and molecular events that may influence the response of the postthrombotic brain to secondary insults. We investigated how a thromboembolic insult would affect histopathological outcome when combined with an ischemic insult induced 24 hours later.

Methods: Three groups of rats underwent either (1) CCAT+10 minutes of normothermic 2-vessel occlusion (n=6), (2) CCAT+sham ischemia procedures (n=6), or (3) sham CCAT procedures+10 minutes of 2-vessel occlusion (n=6).

View Article and Find Full Text PDF