A distinct subgroup of small DRG cells express GDNF receptor components and GDNF is protective for these neurons after nerve injury

Several lines of evidence suggest that neurotrophin administration may be of some therapeutic benefit in the treatment of peripheral neuropathy. However, a third of sensory neurons do not express receptors for the neurotrophins. These neurons are of small diameter and can be identified by the binding of the lectin IB4 and the expression of the enzyme thiamine monophosphatase (TMP). Here we show that these neurons express the receptor components for glial-derived neurotrophic factor (GDNF) signaling (RET, GFRalpha-1, and GFRalpha-2). In lumbar dorsal root ganglia, virtually all IB4-labeled cells express RET mRNA, and the majority of these cells (79%) also express GFRalpha-1, GFRalpha-2, or GFRalpha-1 plus GFRalpha-2. GDNF, but not nerve growth factor (NGF), can prevent several axotomy-induced changes in these neurons, including the downregulation of IB4 binding, TMP activity, and somatostatin expression. GDNF also prevents the slowing of conduction velocity that normally occurs after axotomy in a population of small diameter DRG cells and the A-fiber sprouting into lamina II of the dorsal horn. GDNF therefore may be useful in the treatment of peripheral neuropathies and may protect peripheral neurons that are refractory to neurotrophin treatment.

Response of lens epithelial cells to hydrogen peroxide stress and the protective effect of caloric restriction

Hydrogen peroxide (H2O2) has been reported to be present at significant levels in the lens and aqueous humor in some cataract patients and suggested as a possible source of chronically inflicted damage to lens epithelial (LE) cells. We measured H2O2 effects on bovine and mouse LE cells and determined whether LE cells from old calorically restricted mice were more resistant to H2O2-induced cellular damage than those of same age ad libitum fed (AL) mice. Bovine lens epithelial cells were exposed to H2O2 at 40 or 400 microM for 2 h and then allowed to recover from the stress. The cells were assayed for DNA damage, DNA synthesis, cell viability, cell morphology, response to growth stimuli, and proliferation potential. Hydrogen peroxide-treated cells showed an increased DNA unwinding 50% greater than that for untreated controls. These DNA strand breaks appeared to be almost completely rejoined by 30 min following removal of the cells from a 2-h exposure. The 40 microM exposure did not produce a significantly lower DNA synthesis rate than the control, it responded to growth factor stimuli, and it replicated as did the control cells after removal of H2O2. The 400 microM H2O2 severely affected DNA synthesis and replication, as shown by increased cell size and by markedly reduced clonal cell growth. The cells did not respond to growth stimulation by serum or growth factors and lost irreversibly the capacity to proliferate. The responses of LE cells from old adlib diet (AL) and calorically restricted (CR) mice to H2O2 were significantly different. Exposure of LE cells to 20, 40, or 100 microM H2O2 for 1 h induces a significant loss of cellular proliferation in cells from old AL mice. LE cells from long-term CR mice of the same strain and age were more resistant to oxidative damage at all three concentrations of H2O2 than those of both old and young AL mice and showed a significantly higher proliferation potential following treatment. It is concluded that CR results in superior resistance to reactive oxygen radicals in the lens epithelium.

[A clinicopathological study on panniculitic T-cell lymphoma]

OBJECTIVE

To analyse the pathomorphology and clinical behavior of panniculitic T-cell lymphoma (PTCL) and to study the classification and name of PTCL.

METHODS

Routine pathological and immunohistochemical methods were utilized to analyse 4 cases of PTCL.

RESULTS

All patients presented with 1 to 3 cm diameter subcutaneous nodules accompanied by high fever. The clinical course of these patients was distinctive and progressive. All patients died within 4-9 months. Histologically, the lesions were composed of medium sized atypical cells (CD45RO+) infiltrating between fat cells, large numbers of bean bag cells (CD68+) could be observed.

CONCLUSIONS

PTCL is a type of peripheral T-cell lymphoma which is highly malignant.

Combined treatment of acute EAE in Lewis rats with TNF-binding protein and interleukin-1 receptor antagonist

Experimental autoimmune encephalomyelitis (EAE) is a term given to describe a collection of animal models representing the human disease multiple sclerosis (MS). Although not fully understood, the involvement of cytokines and the immune system in either EAE or human MS is well established. Past efforts have shown that inhibition of proinflammatory cytokines tumor necrosis factor (TNF-alpha) or interleukin-1 (IL-1) result in amelioration of acute EAE in Lewis rats. The present study examined this model for the effect of concomitant inhibition of both TNF-alpha and IL-1, which resulted in a modest but significant therapeutic effect that was superior to inhibition of either single agent alone with respect to four of the five variables used to follow the progression of disease in this model, i.e., clinical severity, frequency of disease, loss of body weight, and day of onset. These results are in accordance with the idea that combination treatments are likely to prove superior to single agent therapy in the treatment of autoimmune inflammatory disease.

Isolation and identification of berberine from cell cultures of Coptis chinensis

Calli were formed by the young leaves of Coptis chinensis inoculated onto a 6,7-V solid medium containing 1.0-2.0 mg/L of 2,4-D and 0.1 mg/L of kinetin. The loose calli were chosen and transferred into a liquid medium and free cells and cell aggregates were obtained. Cell lines with a higher content of berberine were selected by irradiation of suspension culture and a plate-screening technique. After 35 subcultures, the selected cell lines were cultured in a larger quantity for the extraction of alkaloids. Yellow crystals were obtained from the extracts and identified as berberine by TCL, UV and IR absorption, and mass spectrography. They have the same molecular structure and anti-bacterium activities as the berberine obtained from natural plants.

SPARC is expressed by ganglion cells and astrocytes in bovine retina

SPARC (secreted protein, acidic and rich in cysteine)/osteonectin is a matricellular, counteradhesive glycoprotein that disrupts cell-matrix interactions, interacts with growth factors and components of extracellular matrix, and modulates the cell cycle, but appears to subserve only minor structural roles. SPARC is expressed in a variety of tissues during embryogenesis and remodeling and is believed to regulate vascular morphogenesis and cellular differentiation. Although usually limited in normal adult tissues, SPARC is expressed at significant levels in the adult central nervous system. Using a monoclonal antibody against bovine bone osteonectin, we have determined the localization of SPARC in newborn (3-day-old) and adult (4-8-year-old) normal bovine retinas. SPARC was present in the soma of ganglion cells and strong reactivity was found in ganglion cell axons. Muller cells displayed no immunoreactivity, but SPARC was present in retinal astrocytes that were identified by the astrocyte marker glial fibrillary acidic protein (GFAP). Newborn calf retina showed a staining pattern similar to that of adult retina but exhibited significantly reduced levels of SPARC. Minimal levels of SPARC protein were also detected in some capillaries of the inner retina of both newborn and adult animals, whereas large vessels were negative. The presence of SPARC in the retina was confirmed by Western blotting of retinal extracts. These data indicate that SPARC originating from bot h neurons and glia of the inner retina may be an important modulator of retinal angiogenesis. The increased expression of SPARC in adult relative to newborn retinal tissue also indicates that SPARC has an ongoing role in the maintenance of retinal functions.

Differential regulation by MK801 of immediate-early genes, brain-derived neurotrophic factor and trk receptor mRNA induced by a kindling after-discharge

Transient changes in immediate-early genes and neurotrophin expression produced by kindling stimulation may mediate secondary downstream events involved in kindling development. Recent experiments have demonstrated conclusively that both kindling progression and mossy fibre sprouting are significantly impaired by administration of the N-methyl-D-aspartate (NMDA) receptor antagonist MK801. To further examine the link between kindling, changes in gene expression and the NMDA receptor, we examined the effects of MK801 on neuronal induction of immediate-early genes, brain-derived neurotrophic factor (BDNF) and trk receptor mRNA expression produced by a single electrically induced hippocampal after-discharge in rats. The after-discharge produced a rapid (after 1 h) increase in Fos, Jun-B, c-Jun, Krox-24 mRNA and protein and Krox-20 protein in dentate granule neurons and a delayed, selective expression of Fos, Jun-D and Krox-24 in hilar interneurons. MK801 pretreatment produced a very strong inhibition of Fos, Jun-D and Krox-20 increases in dentate neurons but had a much smaller effect on Jun-B and c-Jun expression. MK801 did not inhibit Krox-24 expression in granule neurons or the delayed expression of Fos, Jun-D and Krox-24 in hilar interneurons. BDNF protein and trk B and trk C mRNA expression were also strongly induced in dentate granule cells 4 h following an after-discharge. MK801 abolished the increase in BDNF protein and trk B, but not trk C mRNA in granule cells at 4 h. These results demonstrate that MK801 differentially regulates the AD-increased expression of a group of genes previously identified as being likely candidates for an involvement in kindling. Because MK801 significantly retards the development of kindling and mossy fibre sprouting, it can be argued that those genes whose induction is not significantly attenuated by MK801 are unlikely to play an important role in the MK801-sensitive component of kindling and the changes in neural connectivity (mossy fibre sprouting) associated with kindling. Conversely, the role in kindling of those genes whose expression was significantly attenuated by MK801 (Fos, Jun-D, Krox-20, trkB and BDNF) requires further examination.

Brain-derived neurotrophic factor fails to arrest neuromuscular disorders in the paralysé mouse mutant, a model of motoneuron disease

Several new neurotrophic factors have been recently identified and shown to prevent motoneuron death in vitro and in vivo. One such agent is brain-derived neurotrophic factor (BDNF). In this study, we tested BDNF on an animal model of early-onset motoneuron disease: the paralysé mouse mutant, characterized by a progressive skeletal muscle atrophy and the loss of 30-35% of spinal lumbar motoneurons between the first and second week post-natal. The results show that subcutaneous injections of 1 or 10 mg/kg BDNF did not have any significant effect in increasing the mean survival time of mutant mice or in preventing the loss of motor function and total body weight in paralysé mice. The weight and choline acetyltransferase activity of specific muscles and the number of motoneurons in the spinal cords were identical in BDNF-treated and placebo-injected paralysé mice. These results suggest that BDNF does not act on the disease process in paralysé mice in the conditions we used. By contrast, BDNF has previously been shown to partially prevent the loss of motor function in the wobbler mouse, a suggested model of later-onset motoneuron disease. Taken together these findings suggest that BDNF acts differently on early and late-onset motoneuron diseases. It is however possible that treatment of paralysé mice with BDNF or combinations of different neurotrophic factors prior to the phenotypical expression of the paralysé mutation may prevent the loss of motor function and motoneurons in mutant mice.

Nerve growth factor treatment increases brain-derived neurotrophic factor selectively in TrkA-expressing dorsal root ganglion cells and in their central terminations within the spinal cord

Using immunocytochemistry and in situ hybridization, we have examined the expression of brain-derived neurotrophic factor (BDNF) and of neurotrophin receptors in dorsal root ganglion cells. In the adult rat, BDNF mRNA and protein were found mainly in the subpopulation of cells that express the nerve growth factor (NGF) receptor trkA and the neuropeptide calcitonin gene-related peptide (CGRP). NGF increased BDNF within the trkA/CGRP cells to the extent that almost 90% of trkA cells contained BDNF mRNA after intrathecal NGF treatment, and 80-90% of BDNF-expressing cells contained trkA. Non-trkA cells that expressed BDNF included some trkC cells and some small cells that labeled with the lectin Griffonia simplicifolia IB4, a marker for cells that do not express trks. However, very few trkB cells expressed either BDNF mRNA or protein, and NGF did not increase BDNF expression in non-trkA cells. BDNF protein was anterogradely transported both peripherally and centrally. The central transport resulted in BDNF immunoreactivity in CGRP containing terminal arbors in the dorsal horn of the spinal cord, and this immunoreactivity was increased by NGF treatment. Electron microscopic analysis revealed that the BDNF immunoreactivity was present in finely myelinated and unmyelinated axons and in axon terminals, where it was most concentrated over dense-cored vesicles. Our data do not support an autocrine or paracrine role for BDNF within normal dorsal root ganglia, but indicate that BDNF may act as an anterograde trophic messenger. NGF levels in the periphery could influence dorsal horn neurons via release of BDNF from primary afferents.

Mechanism of tubulin-colchicine recognition: a kinetic study of the binding of the colchicine analogues colchicide and isocolchicine

Colchicide (IDE) is a colchicine (COL) analogue in which the C-10 methoxy group is replaced by a hydrogen atom. Its binding to tubulin is accompanied by a quenching of the protein fluorescence. The fluorescence decrease shows a monoexponential time dependence. The observed rate constant increases in a non-linear way with the total concentration of IDE, allowing the determination of a binding constant for an initial binding site (K1=5300+/-300 M-1) and the rate constant for the subsequent isomerization (k2=0.071+/-0.002 s-1) at 25 degrees C. The rate constant, k-2, for the reversed isomerization can be determined by displacement experiments. Despite the minor alteration of the C-ring substituent, the kinetic and thermodynamic parameters of binding are substantially different from those of COL itself, for both steps. In isocolchicine (ISO) the carbonyl oxygen atom and the methoxy groups of the C-ring have been interchanged. Its binding to tubulin only results in small fluorescence and absorbance changes. Therefore competition experiments with MTC [2-methoxy-5-(2',3',4'-trimethoxyphenyl)-2,4, 6-cycloheptatrien-1-one] were performed. ISO competes rapidly and with low affinity with MTC. Fluorimetric titrations of tubulin with MDL (MDL 27048 or trans-1-(2,5 dimethoxyphenyl)-3-[4-(dimethylamino)phenyl]-2-methyl-2-propen-1 -one) in the presence and absence of ISO give evidence for the existence of a second, slow-reacting low-affinity site for ISO that is not accessible to MTC or MDL. The relevance of these results for the recognition of COL is analysed.

GDNF is a trophic factor for adult rat corticospinal neurons and promotes their long-term survival after axotomy in vivo

Glial cell line-derived neurotrophic factor (GDNF) is a trophic factor for several neuronal populations involved in motor control. The present study evaluates the trophic actions of GDNF on corticospinal neurons, an important central nervous system motor projection into the spinal cord. Death of spinal motoneurons and corticospinal neurons is observed in the neurodegenerative disease amyotrophic lateral sclerosis. Axotomy of adult rat corticospinal neurons at internal capsule levels induces half of them to die, and the surviving population displays severe atrophy. To examine the trophic effects of GDNF on corticospinal neurons, Fast Blue-labelled corticospinal neurons were stereotaxically axotomized at internal capsule levels and GDNF was infused intracortically to lesioned corticospinal neurons at total doses of 2, 4, 10, 20, 40, 100 and 300 microg for 7 days. GDNF prevented axotomy-induced death of corticospinal neurons at doses between 2 and 40 microg and abolished or attenuated their atrophy at all doses examined. In addition, treatment with 8 microg GDNF for the first 2 weeks after axotomy resulted in the long-term survival of corticospinal neurons for 42 days. With regard to the development of treatment strategies for upper motoneuron degeneration in amyotrophic lateral sclerosis, application of GDNF via the cerebrospinal fluid may be more relevant than intracortical delivery as its diffusion within the brain parenchyma is limited. Intraventricular as well as intracisternal infusion of GDNF (300 microg over 7 days) completely prevented corticospinal neuron death. These results show that GDNF promotes the long-term survival of corticospinal neurons and has a positive effect on their size in vivo. Furthermore, the survival-promoting effect of GDNF on corticospinal neurons after delivery via cerebrospinal fluid has important clinical implications for potential treatment of the upper motoneuron degeneration seen in amyotrophic lateral sclerosis.

Regenerative changes in median nerve defects using various rabbit skeletal muscles

We examined the morphological changes of median nerve regeneration which situated to pass through degenerative latissimus dorsi and brachial triceps muscles in rabbits. Morphological observation was performed at 7, 14, 28, 45, 60 and 180 days after the creation of defect of the bilateral median nerves. Regenerative nerve fibers were observed in the residual tubes of left degenerative muscle bridges. In this respect the regenerative effect of the latissimus dorsi was better than that of the brachial triceps. These results suggest that regular and longer muscle fibers as those of latissimus dorsi may contribute to the effective regeneration of nerve.

Brain-derived neurotrophic factor is reduced in Alzheimer's disease

Alzheimer's disease may be due to a deficiency in neurotrophin protein or receptor expression. Consistent with this hypothesis, a reduction in BDNF mRNA expression has been observed in human post-mortem Alzheimer's disease hippocampi. To further investigate this observation, we examined whether the alteration in BDNF expression also occurred at the protein level in human post-mortem Alzheimer's disease hippocampi and temporal cortices using immunohistochemical techniques. We observed a reduction in the intensity and number of BDNF-immunoreactive cell bodies within both the Alzheimer's disease hippocampus and temporal cortex when compared to normal tissue. These results support and extend previous findings that BDNF mRNA is reduced in the human Alzheimer's disease hippocampus and temporal cortex, and suggest that a loss of BDNF may contribute to the progressive atrophy of neurons in Alzheimer's disease.

IB4-binding DRG neurons switch from NGF to GDNF dependence in early postnatal life

We have tested the role of glial cell line-derived neurotrophic factor (GDNF) in regulating a group of putatively nociceptive dorsal root ganglion (DRG) neurons that do not express calcitonin gene-related peptide (CGRP) and that downregulate the nerve growth factor (NGF) receptor tyrosine kinase, TrkA, after birth. We show that mRNA and protein for the GDNF receptor tyrosine kinase, Ret, are expressed in the DRG in patterns that differ markedly from those of any of the neurotrophin receptors. Most strikingly, a population of small neurons initiates expression of Ret between embryonic day 15.5 and postnatal day 7.5 and maintains Ret expression into adulthood. These Ret-expressing small neurons are selectively labeled by the lectin IB4 and project to lamina IIi of the dorsal horn. Ret-expressing neurons also express the glycosyl-phosphatidyl inositol-linked (GPI-linked) GDNF binding component GDNFR-alpha and retrogradely transport 125I-GDNF, indicating the presence of a biologically active GDNF receptor complex. In vitro, GDNF supports the survival of small neurons that express Ret and bind IB4 while failing to support the survival of neurons expressing TrkA and CGRP. Together, our findings suggest that IB4-binding neurons switch from dependence on NGF in embryonic life to dependence on GDNF in postnatal life and are likely regulated by GDNF in maturity.

Long-term survival effects of GDNF on neonatal rat facial motoneurons after axotomy

Glial cell-line derived neurotrophic factor (GDNF) has survival promoting effects on axotomized neonatal motoneurons. We examined how long it could sustain motoneurons after postnatal day O (PND) facial nerve axotomy. GDNF, or cytochrome c as a negative control, were locally administered by Gelfoam implants at the time of axotomy and some were re-implanted on PND 14. The surviving motoneurons were quantified on PND 14 and 28. GDNF completely rescued lesioned motoneurons from axotomy-induced cell death at 14 days and was still effective (about 40%) at PND 28. GDNF also prevented axotomy-induced atrophy at both PND 14 and 28, indicating that the neurotrophic effects of GDNF on neonatal motoneurons are long-term.

Expression of brain-derived neurotrophic factor protein in the adult rat central nervous system

We have generated and characterized a multi-functional polyclonal anti-brain-derived neurotrophic factor antibody. Western blot analysis, dorsal root ganglion neurite outgrowth and dorsal root ganglion neuron survival assays showed that this antibody specifically recognized brain-derived neurotrophic factor and not the other neurotrophins. Furthermore, it was capable of blocking the functional effects of brain-derived neurotrophic factor. Using this antibody, we examined the expression of brain-derived neurotrophic factor in adult rat brains by immunohistochemistry. We found distinct brain-derived neurotrophic factor immunoreactivity in several structures of the brain. These included the neocortex, piriform cortex, amygdaloid complex, hippocampal formation, claustrum, some thalamic and hypothalamic nuclei, the substantia nigra and some brainstem structures. In contrast to brain-derived neurotrophic factor messenger RNA expression, brain-derived neurotrophic factor immunoreactivity was also found in the lateral septum, bed nucleus of the stria teminalis, medial preoptic nucleus, olivery pretectal nucleus, lateral paragigantocellular nucleus and the dorsal horn of the spinal cord. In normal adult rat brains, there was little or no staining in the CA1 region or the granule cell layer of the dentate gyrus of the hippocampus. However, kainate treatments greatly increased brain-derived neurotrophic factor immunoreactivity in the pyramidal cells of the CA1 region, as well as in the dentate gyrus, CA2 and CA3 hippocampal regions. We present evidence for both the subcellular localization and anterograde transport of endogenous brain-derived neurotrophic factor in the central nervous system. The detection of brain-derived neurotrophic factor protein in several discrete regions of the adult brain, and brain-derived neurotrophic factor's dramatic up-regulation following kainate treatment, strongly supports a role of brain-derived neurotrophic factor in the maintenance of adult neurons and synapses. Since several populations of neurons lost during neurodegenerative diseases synthesize brain-derived neurotrophic factor protein, modulation of brain-derived neurotrophic factor levels may be clinically beneficial. The antibody described in this paper will be helpful in determining more precisely the functional activities of brain-derived neurotrophic factor in the adult.

Marked age-dependent neuroprotection by brain-derived neurotrophic factor against neonatal hypoxic-ischemic brain injury

Hypoxic-ischemic brain injury in survivors of perinatal asphyxia is a frequently encountered clinical problem for which there is currently no effective therapy. Neurotrophins, such as brain-derived neurotrophic factor (BDNF), can protect responsive neurons against cell death in some injury paradigms. While the role of BDNF in hypoxic-ischemic brain injury is not clear, evidence suggests that BDNF may have different effects in the developing, as opposed to the adult, brain. We found that a single intracerebroventricular (ICV) injection of BDNF resulted in rapid and robust phosphorylation of trk receptors in multiple brain regions in the postnatal day (PD) 7 rat brain. BDNF also markedly protected against hypoxic-ischemic brain injury at PD7. It protected against 90% of tissue loss due to hypoxic-ischemia when given just prior to the insult and against 50% of tissue loss when give after the insult. In contrast, ICV injection of BDNF in PD21 and adult rats resulted in little trk phosphorylation and less dramatic protection against unilateral hypoxic-ischemic injury at PD21. Because of its potent neuroprotective actions in the developing brain, BDNF may be a potential treatment for asphyxia and other forms of acute injury in the perinatal period.

Distribution of brain-derived neurotrophic factor (BDNF) protein and mRNA in the normal adult rat CNS: evidence for anterograde axonal transport

A sensitive immunohistochemical technique was used, along with highly specific affinity-purified antibodies to brain-derived neurotrophic factor (BDNF), to generate a detailed mapping of BDNF immunoreactivity (BDNF-ir) throughout the adult rat CNS. A parallel analysis of sites of BDNF synthesis was performed with in situ hybridization techniques using a cRNA probe to the exon encoding mature rat BDNF protein. These combined data revealed (1) groups of cell bodies containing diffuse BDNF-ir throughout the CNS that were strongly correlated with fields of cells containing BDNF mRNA; (2) varying degrees of BDNF-ir outside of cell bodies, in what appeared to be fibers and/or terminals; and (3) many regions containing extremely heavy BDNF-immunoreactive fiber/terminal labeling that lacked BDNF mRNA (e.g., medial habenula, central nucleus of the amygdala, bed nucleus of stria terminalis, lateral septum, and spinal cord). The latter observation suggested that in these regions BDNF was derived from anterograde axonal transport by afferent systems. In the two cases in which this hypothesis was tested by the elimination of select afferents, BDNF immunostaining was completely eliminated. These data, along with the observation that BDNF-ir was rarely found within dendrites or fibers en passage, suggest that BDNF protein produced in adult CNS neurons is polarized primarily along axonal processes and is preferentially stored in terminals within the innervation target.

Immunocytochemical localization of TrkB in the central nervous system of the adult rat

The TrkB family of transmembrane proteins serve as receptors for brain-derived neurotrophic factor (BDNF), neurotrophin (NT)-4/5, and possibly NT-3, three members of the neurotrophin family of neurotrophic factors. In order to understand the potential roles played by these receptors, we have examined the distribution of the TrkB receptor proteins in the adult rat brain by using immunohistochemistry. Several different antisera, directed against either synthetic peptides corresponding to different regions of TrkB or a recombinant fusion protein comprising part of the extracellular domain, were generated. Each of these antisera was directed to epitopes found on all known TrkB isoforms (both the tyrosine kinase-possessing isoform and the truncated kinase-lacking isoforms). In addition, a commercially available antibody to the intracellular domain of TrkB was also used. Widespread and distinct staining was observed on the surface of neuronal cell bodies, axons, and dendrites in many structures, including the cerebral cortex, hippocampus, dentate gyrus, striatum, septal nuclei, substantia nigra, cerebellar Purkinje cells, brainstem and spinal motor neurons, and brainstem sensory nuclei. Staining was also observed in the pia matter, on a subpopulation of ependymal cells lining the cerebral ventricle wall, and other nonneuronal cells. The expression pattern of TrkB receptor protein suggests that TrkB plays a broad role in the central nervous system. In addition, the detection of TrkB immunoreactivity on cell bodies and dendrites is consistent with recent models suggesting that neurotrophins may be derived from presynaptic and/or autocrine sources in addition to the classical postsynaptic target.

Glial cell line-derived neurotrophic factor (GDNF) is a neurotrophic factor for sensory neurons: comparison with the effects of the neurotrophins

We compared the effects of glial cell line-derived neurotrophic factor (GDNF) on dorsal root ganglion (DRG) sensory neurons to that of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin 3 (NT-3). All of these factors were retrogradely transported to subpopulations of sensory neuron cell bodies in the L4/ L5 DRG of neonatal rats. The size distribution of 125I-GDNF-labeled neurons was variable and consisted of both small and large DRG neurons (mean of 506.60 microns2). 125I-NGF was preferentially taken up by small neurons with a mean cross-sectional area of 383.03 microns2. Iodinated BDNF and NT-3 were transported by medium to large neurons with mean sizes of 501.48 and 529.27 microns2, respectively. A neonatal, sciatic nerve axotomy-induced cell death model was used to determine whether any of these factors could influence DRG neuron survival in vivo. GDNF and NGF rescued nearly 100% of the sensory neurons. BDNF and NT-3 did not promote any detectable level of neuronal survival despite the fact that they underwent retrograde transport. We examined the in vitro survival-promoting ability of these factors on neonatal DRG neuronal cultures derived from neonatal rats. GDNF, NGF, and NT-3 were effective in vitro, while BDNF was not. The range of effects seen in the models described here underscores the importance of testing neuronal responsiveness in more than one model. The biological responsiveness of DRG neurons to GDNF in multiple models suggests that this factor may play a role in the development and maintenance of sensory neurons.

Long-term caloric restriction delays age-related decline in proliferation capacity of murine lens epithelial cells in vitro and in vivo

PURPOSE

The goal of this study was to examine the effects of age and long-term caloric restriction on the proliferation capacity of murine lens epithelial (LE) cells in vitro and in vivo.

METHODS

B6D2F1 (C57BL/6 X DBA/2) F1 mice 4 to 45 months of age were obtained and fed either an ad libitum (AL) or a calorically restricted (CR) diet (60% of AL intake). Cellular proliferation capacity in vitro was measured using the colony size distribution assay for 10-day clonal growth of mouse LE cells. Proliferation rate in vivo was assayed using immunostaining for 5-bromo-2'-deoxyuridine (BrdU) in mouse LE cells after 2-week osmotic pump delivery of BrdU.

RESULTS

Proliferative capacity of cells from old AL mice decreased significantly in comparison to cells from young AL and old CR mice, as determined by the fractions of cells capable of forming small (no or one cell division) and large (four or more cell divisions) colonies in vitro. There was also a decline in cell replicative rate as measured by BrdU labeling index (LI) in vivo with increasing age in AL and CR mice. However, this decline was marked in AL mice between 10 and 30 months of age and minimal in CR mice. Significant differences in BudU LI between AL and CR mice occurred when animals were 30 months of age or older. This finding indicates that an age-related decline in cellular proliferation rate in vivo was delayed by CR.

CONCLUSIONS

A significantly reduced proliferative capacity of LE cells is associated with increased age of mice and is delayed by long-term caloric restriction as measured in vitro and in vivo. How caloric restriction mediates its effects on LE cell proliferation remains to be investigated further.

Pharmacological characterization of glial cell line-derived neurotrophic factor (GDNF): implications for GDNF as a therapeutic molecule for treating neurodegenerative diseases

This review presents a comprehensive survey of the recently described pharmacological activities of glial cell line-derived neurotrophic factor on the central nervous system.

Pharmacokinetics of intrathecally applied BDNF and effects on spinal motoneurons

Brain-derived neurotrophic factor (BDNF) is a potential drug for treatment of amyotrophic lateral sclerosis. Previous studies have demonstrated little or no penetration of the blood-brain barrier by BDNF, hence systemic application does not result in significant penetration into the spinal cord to produce direct action on motoneurons. Intrathecal (i.th) application of BDNF to sheep was investigated as a mean of topical administration. After continuous infusion a caudalcranial gradient of BDNF concentration in cerebrospinal fluid (CSF) and at the meninges was observed. BDNF did not penetrate spinal parenchyma but accumulated in spinal motoneurons probably due to axonal uptake in ventral roots and subsequent retrograde transport. Spinal motoneurons showed reduced levels of tropomyosin receptor kinase (trk) B and increased levels of c-fos at high BDNF doses in comparison to treatment with saline, even after treatment periods of several months. After bolus injection and cessation of continuous delivery multiphasic reduction of the BDNF concentration in CSF was detected. Our study demonstrates that i.th. application of BDNF is feasible, setting the stage for future clinical trials.

Primary culture and characterization of microvascular endothelial cells from Macaca monkey retina

PURPOSE

To develop methods for the culture of microvascular endothelial cells (EC) from Macaca monkey retina and to investigate their propagation and survival in vitro.

METHODS

Endothelial cells from capillary fragments were cultured on fibronectin-coated dishes in QB-58 serum-free medium containing 20 microliters/ml bovine retinal extract, 90 micrograms/ml heparin, 10% fetal bovine serum, and 10% monkey serum. Non-EC were removed manually. Endothelial cell-specific properties were assessed by endocytosis of acetylated low-density lipoprotein (ac-LDL) and by immunocytochemical staining. The response to growth factors was assayed by 3H-thymidine incorporation. The synthesis of matrix macromolecules was studied by metabolic labeling with 3H-proline and identification by sodium dodecyl sulfate-polyacrylamide gel electrophoresis-immunoblotting.

RESULTS

Under these culture conditions, migrating cells emerged from capillary fragments after 1 to 2 days and formed large colonies by 1 week. Cells exhibited a mean doubling time of 44.5 hours during the first 3 to 5 days of culture and 23 hours at 6 to 8 days in culture, and they formed a confluent monolayer by 12 to 14 days. These cells demonstrated uptake of ac-LDL, expressed von Willebrand factor and the cell adhesion protein CD31, and did not contain smooth muscle alpha-actin. Before purification, 92% of the cells in primary cultures were identified as EC. The EC could be maintained in vitro for more than 1 month without the addition of growth factors; however, basic fibroblast growth factor and vascular endothelial growth factor each stimulated cell replication. Secreted extracellular proteins included fibronectin, collagen types I and IV, laminin, and SPARC (secreted protein, acidic, and rich in cysteine).

CONCLUSIONS

This study is the first description of the culture and propagation of purified retinal EC from Macaca monkey, a widely accepted model for the human retina. These cultures will be highly relevant to studies of abnormal vascular disease in the human eye.

Quantitative research for improving respiratory muscle contraction by breathing exercise

OBJECTIVE

To investigate the effects of breathing exercise on chronic obstructive pulmonary disease (COPD).

PATIENTS AND METHODS

324 patients stable COPD were randomly assigned to either the breathing exercise group (Group I) or control group consisting of placebo (Group II). The maximum respiratory pressure (320 cases) and transdiaphragmatic pressure (129 cases) were monitored via RMS-I and Type-2 pressure measurements. The breathing exercises were taught and checked by experienced specialists periodically. Comparison was made between Group I and Group II using maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), diaphragmatic pressure (Pdi) and maximum transdiaphragmatic pressure (Pdimax) after 1 to 20 months.

RESULTS

In Group I MIP increased by 30.42%, MEP 32.10%, Pdi 30.94% and Pdimax 65.59% (P < 0.001). No significant changes were observed in Group II given the placebo. The MIP, MEP, Pdi and Pdimax were 6.95%, 2.92%, 14.63 and 9.05% respectively (P > 0.05).

CONCLUSIONS

Breathing exercise has a potent and long lasting effect on respiratory muscle contraction. The methods mentioned above can be used as standard quantitative index for contractile properties of respiratory muscle.

Distribution of brain-derived neurotrophic factor in the rat pituitary gland

Immunohistochemical techniques were used to determine the distribution of brain-derived neurotrophic factor (BDNF) in the adult rat pituitary gland. In the posterior lobe, BDNF staining was found only within fibers. Within the intermediate lobe, nearly all cells were labeled intensely for BDNF. In the anterior lobe, varying degrees of BDNF immunoreactivity were observed exclusively in cells shown by double-labeling techniques to contain thyroid stimulating hormone (TSH), although not all TSH-positive cells contained detectable BDNF labeling. These results are consistent with and extend information from previous studies demonstrating BDNF expression in the pituitary gland and further support the idea that this neurotrophin plays a role in endocrine function.

Notch4/int-3, a mammary proto-oncogene, is an endothelial cell-specific mammalian Notch gene

The int-3 oncogene was identified as a frequent target in Mouse Mammary Tumor Virus (MMTV)-induced mammary carcinomas and encodes the intracellular domain of a novel mouse Notch gene. To investigate the role of the int-3 proto-oncogene in mouse development and carcinogenesis, we isolated cDNA clones corresponding to the entire coding potential of the int-3 proto-oncogene. We propose to name this gene Notch4 and reserve the int-3 nomenclature for references to the oncogenic form. The deduced amino acid sequence of Notch4 contains conserved motifs found in Notch proteins; however Notch4 has fewer epidermal growth factor (EGF)-like repeats and a shorter intracellular domain than other mouse Notch homologues. Comparison of the coding potential of the int-3 gene to that of Notch4 suggests that loss of the extracellular domain of Notch4 leads to constitutive activation of this murine Notch protein. In situ hybridization revealed that Notch4 transcripts are primarily restricted to endothelial cells in embryonic and adult life. Truncated Notch4 transcripts were detected in post-meiotic male germ cells. The distinct Notch4 protein features and its restricted expression pattern suggests a specific role for Notch4 during development of vertebrate endothelium.

[A quantitative study on the effect of breathing exercises in improving respiratory muscle contration]

To study quantitatively the effect of breathing exercises on the prevention of progression in chronic obstructive pulmonary disease (COPD), 324 patients with stable COPD were randomly assigned to either breathing exercises (BE) or placebo medicine as control. The maximum respiratory pressure (320 cases) and transdiaphragmatic pressure (129 cases) were monitored with RMS-1 and Type-2 gastrointestinal pressure measuring instrument. BE were taught and checked by experienced specialists periodically. Patients in BE group were compared with those in the control group by measuring MIP, MEP, Pdi, and Pdimax after one to 20 months. In BE group MIP increased by 30.42%, MEP 32.10%, Pdi 30.94%, and Pdimax 65.59% (P < 0.001). No significant change was observed in the control group. MIP, MEP, Pdi, and Pdimax increased by 6.95%, 2.92%, 14.63% and 9.05% respectively (P < 0.05) in the control group. It is shown preliminarily that BE had potent and lasting effect on respiratory muscle contraction after studying large number of cases. The methods mentioned above can be used as quantitative indices for the contractile properties of respiratory muscle.

Cell-specific regulation of the stably expressed serotonin 5-HT1A receptor and altered ganglioside synthesis

Neurotransmission is dependent on the presence of neuronal receptors at the synapses, and important cell surface molecules such as gangliosides are pivotal in the maintenance of synaptic contacts. To study the interrelationship between these two classes of molecules, we achieved stable expression of the hippocampus- and CNS-localized serotonin 1A receptor (5-HT1A-R) in three 5-HT1A-R-deficient neuronal cell lines and also the control, non-neural CHO cells. A strong passage dependence of 5-HT1A-R expression, as measured by mRNA levels as well as membrane binding to the selective agonist [3H]8-OH-DPAT, was observed only in the HN2 (hippocampal) and NCB-20 (CNS) cells which are derived from tissues of natural occurrence of the 5-HT1A-R. A paradigm of stress was obtained by carrying out continuous culture of cells without feeding. During this time a dramatic increase in 5-HT1A-R mRNA and [3H]8-OH-DPAT binding was observed only in the neuronal cells after confluence and during decreased cell viability (days 10/11). This was not due to differentiation, since deliberate serum deprivation and differentiation of cells did not result in any dramatic increase in 5-HT1A-R expression. Analysis of ganglioside synthesis by pulse labeling of the transfected cells produced striking results. In the dorsal root of the ganglion (DRG) derived F-11 cells which show low but significant levels of complex gangliosides before transfection, the mere presence of the serotonin 1A receptor resulted in a dramatic increase in synthesis of gangliosides comigrating with GM2, GD1a, GD1b, and GT1b (20-fold by densitometry). In contrast, there was only a 2-fold increase in the overall content of complex gangliosides in the presence of the 5-HT1A-R. In the NCB-20 cells which contain only GD1a but no GD1b or GT1b before transfection, a decrease in GD1a synthesis was observed following transfection. Also agonist (8-OH-DPAT) binding to the serotonin 1A receptor in NCB-20 cells produced a 3-fold increase in synthesis of a ganglioside comigrating with GM3. Thus, our neuroblastoma transfectants help demonstrate stress-induced regulation of the 5-HT1A-R, which in turn exerts a strong and cell type-specific control over such essential cell-surface determinants like gangliosides.

[A study of the association between EBV and B-cell lymphoma]

Extensive studies have demonstrated that Epstein-Barr virus (EBV) is associated with Burkitt's lymphoma, immunodeficiency related lymphoma, Hodgkin's disease and T-cell lymphoma. In order to investigate whether an association exists between EBV and B-cell lymphoma in patients without overt immunodeficiency, we examined 127 B-cell lymphomas without overt immunodeficiency for expression of EBV-encoded small RNA (EBER-1) using RNA/RNA in situ hybridization. EBER-1 expression was found in nuclei of tumor cells in 8 of 127 cases (6.3%) of B-cell lymphomas. This result is similar to that of studies in Europe and the United States (about 5%). The low frequency of EBV in B-cell lymphomas suggests that EBV does not pay an important role in the pathogenesis of B-cell lymphomas without overt immunodeficiency.

Identification of somatic hybrids between rice cultivar and wild Oryza species by RAPD

The somatic hybrids between rice cultivar and wild Oryza species were obtained by the PEG and electrical fusion method. The somatic hybrids were identified with PAPD. It was verified that the genome of somatic hybrids contained some genomes from both parents, but they contributed unequally. In some somatic hybrids, the portion from one parent was more than the other. The relationship between somatic hybrids and their parents was analyzed based on RAPD data.

Retinal pigment epithelial wound healing in vivo

OBJECTIVE

To develop an in vivo rabbit model of retinal pigment epithelial wound healing that preserves the overlying retina.

METHODS

Hydraulic débridement of the retinal pigment epithelium was performed in one eye of 35 pigmented rabbits by means of a pars plana vitrectomy approach. Five of the 35 eyes were examined by stereoscopic color fundus photography, fluorescein angiography, and light microscopy on each of the following postoperative days: 0, 2, 4, 7, 14, 28, and 56.

RESULTS

Retinal pigment epithelial débridement with this technique results in apical decapitation of the retinal pigment epithelial cells followed by subsequent hydraulic removal of the residual nucleus-containing basal cellular debris. The retinal pigment epithelium-denuded Bruch's membrane was resurfaced mostly by a monolayer of flattened, hypopigmented retinal pigment epithelial cells within 4 days after débridement. Progressive retinal pigment epithelial hyperplasia also occurred beginning between postoperative days 2 and 4.

CONCLUSIONS

Retinal pigment epithelial wound healing after hydraulic débridement occurs rapidly and in a manner initially consistent with sliding migration. Progressive retinal pigment epithelial hyperplasia also occurs and may contribute to this repair process. Further investigation of retinal pigment epithelial repair by means of this in vivo model may provide important insight into the pathogenesis and treatment of outer retinal disorders.

Identification of histatins as tannin-binding proteins in human saliva

Tannins have a number of detrimental biological effects and these include interference with normal growth and metabolism if they are present in the feed of various animals. Proline-rich proteins (PRPs) in saliva have been shown to provide protection against tannin, but little is known about the mechanism of protection and interaction of other salivary proteins with tannin. To identify tannin-binding human salivary proteins, parotid and submandibular/sublingual saliva samples were adsorbed with tannin. PRPs, and in particular a group of low-M(r) proteins, were readily precipitated by tannin. The low-M(r) proteins were purified from parotid saliva and demonstrated to be histatins, a family of well-characterized histidine-rich salivary proteins. The ability of synthetic histatin 5, as well as an acidic PRP (PRP-1) and gelatin to precipitate quebracho condensed tannin and tannic acid was determined. At pH 7.4 histatin 5 was the most effective precipitant of both condensed tannin and tannic acid and it also precipitated the largest amount of condensed tannin at pH 3.0, but the smallest amount of tannic acid at that pH. In contrast PRP-1 showed a greater ability to precipitate both condensed tannin and tannic acid at pH 3.0 than at pH 7.4. Under most circumstances histatin 5 was therefore more effective in precipitating tannins than proteins with high proline content which generally have been recognized as strong precipitants of tannin. Pre-incubation of tannic acid with alpha-amylase inhibited the enzyme, but addition of histatin 5 or the acidic PRP PIF-s protected amylase from inhibition by tannin. Similarly salivary proteins may protect other biological activities in the digestive tract from inhibition by dietary tannin.

[A survey on HIV and HV infection of heroin addicts in Linchang and Kunming]

Serum samples were collected from 353 heroin addicts in Linchang Prefecture and Kunming Area, Yunnan Province for detecting anti-HIV with ELISA and Western Blot, and 319 of them also for detecting various infection markers of hepatitis A, B, C and D with ELISA. Results showed no anti-HIV was found among them, overall infection prevalence rate of hepatitis A, B, C and D was 78.11%, 72.73% for males and 90.91% for females, and 1.57%, 63.97%, 51.85% and 5.79% positive rates for anti-HAV-IgM, HBV markers, anti-HCV and HDAg and/or anti-HD-IgM, respectively. Prevalence of mixed infection with different types of hepatitis was 40.07%, and 35.35% for mixed HBV and HCV. Infection rate of hepatitis B and C in Kunming Area was significantly higher than that in Linchang Prefecture, and so did in Han nationality than in other minority nationalities. It suggests hepatitis viruses infection is caused by drug abuse, use of non-sterilizing syringes with others.

[Expression of Epstein-Barr virus encoded small RNA-1 and latent membrane protein-1 in midline T-cell lymphomas]

Nine cases of midline T-cell lymphoma (MTL) were studied for expression of Epstein-Barr virus (EBV) encoded small RNA-1 (EBER-1) and EBV latent membrane protein-1 (LMP-1) using in situ hybridization and immunohistochemistry respectively. EBER-1 was detected in nuclei of tumor cells in 8/9 cases of MTL and LMP-1 was found on membrane and in cytoplasm of tumor cells in 7/9 cases of MTL. The results show: (1) There is a strong association between EBV and MTL. EBV may play an important role in the pathogenesis of MTL. (2) The detection frequency of EBV in MTL is higher than peripheral T-cell lymphoma from other sites of the body. (3) EBER-1 in situ hybridization and LMP-1 immunohistochemistry are sensitive and reliable in detection of EBV in MTL and the latter is more economic and convenient.

In vivo neurotrophic effects of GDNF on neonatal and adult facial motor neurons

Motor neurons require neurotrophic factor(s) for their survival during development and for maintenance of function in adulthood. In vivo studies have shown that motor neurons respond to a variety of molecules, including ciliary neurotrophic factor, members of the neurotrophin family, and the insulin growth factor IGF-1 (refs 3-13). Here we investigate the potential motor neuron neurotrophic effects of glial-cell-line-derived neurotrophic factor (GDNF), initially identified as a neurotrophic factor for substantia nigra dopaminergic neurons. We find that GDNF is retrogradely transported, in a receptor-mediated fashion, by spinal cord motor neurons in neonatal rats. Local application of GDNF to the transected facial nerve prevents the massive motor neuron cell death and atrophy that normally follows axotomy in the neonatal period. In adult rats, GDNF administered locally or systemically can markedly attenuate the lesion-induced decrease of choline acetyltransferase immunoreactivity in the facial nucleus. Our data indicate that GDNF has very profound neurotrophic effects in vivo on developing as well as on adult motor neurons, and is the most potent motor neuron trophic factor found so far.

A rapid method for PCR amplification of DNA directly from cells fixed in Carnoy's fixative

We describe a method for rapid and efficient polymerase chain reaction (PCR) amplification of specific target DNA sequences directly from cells fixed in 3:1 methanol-acetic acid (Carnoy's fixative) for routine cytogenetic analysis. The fixed cells used had been stored at -20 degrees C from a few weeks up to 6 years. Primer sets used correspond to loci on an autosome (retinoblastoma, RB1), as well as the X (Duchenne muscular dystrophy, DMD) and Y (sex-determining region of the Y, SRY) chromosomes. Sizes of amplified products were the expected 400, 251 and 609 bps, respectively. No differences in quality of amplification products were found between PCR templates obtained from fresh tissues or from cells fixed for varying lengths of time in Carnoy's fixative. This technique has the following advantages: (1) it allows retrospective studies of genetic disorders from archived specimens; (2) it requires only a limited number of cells; (3) it is rapid and simple; and (4) it avoids multistep procedures required in extraction of the DNA.

The biological responses of axotomized adult motoneurons to brain-derived neurotrophic factor

Recent studies showed that brain-derived neurotrophic factor (BDNF) prevents developing motoneurons from naturally occurring and axotomy-induced cell death. Here we examined whether adult motoneurons retain responsiveness to BDNF. Consistent with previous studies, we found that adult spinal and brainstem motoneurons expressed the mRNA of BDNF receptor, trkB. In addition, the trkB immunoreactivities were readily detected in the adult spinal and brainstem motoneurons. We then demonstrated that axotomized adult motoneurons responded to exogenous BDNF. BDNF administered locally markedly attenuated the lesion-induced decrease of ChAT immunoreactivity and activity and enhanced the lesion-induced reexpression of low-affinity NGF receptor immunoreactivity in adult facial motoneurons. Furthermore, we found BDNF administered subcutaneously, intravenously, and into the cerebral ventricle attenuated the lesion-induced decrease of ChAT immunoreactivity in adult facial motoneurons in a dose-dependent fashion. Our data indicate that adult motoneurons retain their responsiveness to BDNF, suggesting that BDNF may be useful as a therapeutic agent for adult motoneuron disease.

NGF and NT-3 have differing effects on the growth of dorsal root axons in developing mammalian spinal cord

The functions of neurotrophins in relation to axon growth and branching during development of the nervous system are unknown. In order to address this question, we have investigated the influences of systemically administered mouse nerve growth factor (mNGF) and human recombinant neurotrophin-3 (hrNT-3) on dorsal root axon growth in the spinal cord of embryonic rats. As anticipated, mNGF has a marked influence on growth of dorsal root axons. In mNGF-treated animals, dorsal root axons in the developing dorsal funiculi and axon collaterals in developing gray matter are substantially longer than those of age-matched controls. Furthermore, growth cones of some dorsal root axons have more than twice the surface area of controls. These effects of NGF are highly selective. Dorsal root axons that occupy a lateral position in white matter and that normally give off collaterals to superficial dorsal horn are prominently affected. Axons that run medially in dorsal columns and that give off collaterals to laminae III and IV and the ventral horn are not demonstrably influenced by treatment with exogenous mNGF. In contrast to the striking effects of mNGF on dorsal root axon growth, the influences of hrNT-3 were considerably more complex. Administration of hrNT-3 increased the mean soma area of DRG neurons, particularly those at the larger end of the size spectrum, consistent with its hypothesized role as a growth factor for proprioceptive sensory neurons. However, in striking contrast to the actions of mNGF, hrNT-3 consistently inhibited axon collateral growth in gray matter at early developmental stages. At later stages, we could not discern a clear-cut influence of hrNT-3 on dorsal root axon growth and branching. We conclude that the ability of mNGF to stimulate axon growth in both white and gray matter is consistent with the idea that mNGF regulates the developing axonal projections of DRG neurons in vivo. In contrast, systemically administered hrNT-3 inhibits the axon collateralizations of DRG neurons in gray matter at early developmental stages. We hypothesize that this inhibitory effect may be related to disruption of a chemotropic gradient of NT-3, or to the widespread expression of the NT-3 receptor trkC, on non-neuronal cells.

Mechanisms of brain injury with deep hypothermic circulatory arrest and protective effects of coenzyme Q10

Sixteen dogs, divided randomly into a control group and coenzyme Q10 group (10mg/kg, intraperitoneally before the operation), underwent deep hypothermic circulatory arrest with cardiopulmonary bypass, as is done clinically. At four time points cerebral cortex and cerebrospinal fluid specimens were collected to study free radical formation, energy metabolism, and ultrastructure. During cardiopulmonary bypass cerebral electron spin resonance spectra and malondialdehyde contents were progressively higher than before bypass, especially at the 60 minutes of circulatory arrest and 30 minutes of reperfusion (p1 < 0.01, p2 < 0.05). In the coenzyme Q10 group at the latter two time points, they had increased less than in the control group at same time points (p1 < 0.02, p2 < 0.005). Adenosine triphosphate content in the cortex during bypass decreased gradually from the prebypass level (p1 < 0.02, p2 = p3 < 0.001), while lactate in cerebrospinal fluid increased (p1 < 0.05, p2 = p3 < 0.001). In the coenzyme Q10 group, adenosine triphosphate at the latter two time points was greater than that in the control group (p1 = p2 < 0.05), while the lactate changes were not significantly different from control at each time point (all p > 0.05). Ultrastructure of the cortex was normal before bypass and almost normal during bypass, but it was obviously abnormal at 60 minutes of circulatory arrest and more seriously abnormal at 30 minutes of reperfusion. In the coenzyme Q10 group the abnormality was obviously reduced. The results suggest that oxygen-derived free radicals and abnormal energy metabolism might play critical roles in brain ischemia/reperfusion injury. Coenzyme Q10 could protect the brain by improving cerebral metabolism.

[Surgical management of hepatic trauma]

In the past 37 years, 207 patients with hepatic injuries were managed in our hospital. Of them, 5 patients died during the preparation for emergency laparotomy. 191 patients were surgically treated, with 11 (5.8%) postoperative deaths, while all 11 patients treated nonsurgically were cured. Finally, we discussed operative methods of hepatic injuries and indications for conservative therapy.

Distribution of intracerebral ventricularly administered neurotrophins in rat brain and its correlation with trk receptor expression

To assess the potential effectiveness by which injected neurotrophins can diffuse throughout the brain, we used autoradiographic and immunohistochemical techniques to examine the brain distributions of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) after a single injection into the lateral cerebral ventricle (ICV) in rats. As described previously, ICV-injected NGF labeled cholinergic neurons in the basal forebrain. Injection of BDNF resulted in few or no labeled neurons in the basal forebrain or in the substantia nigra. However, very intense labeling was associated with the ventricular walls and immediate parenchyma. The distribution of NT-3 after ICV injection was intermediate between that of NGF and BDNF. In the basal forebrain, similar neurotrophin distributions were observed in neonate versus adult animals. Our in situ hybridization analysis has shown that mRNA encoding the BDNF receptor(s) (trkB) is highly expressed by ependymal cells as well as by many neurons and glia. On the other hand, expression of the high-affinity NGF receptor (trkA) is restricted to cholinergic neurons in basal forebrain and striatum. In addition, staining with antisera specific for the trkA or trkB receptors demonstrated that their expression patterns closely reflect their mRNA distributions. Taken together, these data suggest that the presence of the trkB receptor on the ependymal layer of the ventricle and its expression throughout the brain parenchyma represents a significant impediment to the adequate diffusion of ICV-injected BDNF into the brain for delivery to target neurons.

Dextran permeation through poly(N-isopropylacrylamide) hydrogels

The permeation of macromolecules such as fluoroescein-labeled dextran fractions through thermally reversible hydrogels has been investigated. A permeation model has been formulated, which takes into account hydrogel porosity and tortuosity as well as the combined effect of a geometric restraint for a relatively large solute molecule at a pore entrance and the friction between solute molecules moving through the pores and pore walls. Based on this model, we have estimated the tortuosity and average pore size of a swollen hydrogel, poly(N-isopropylacrylamide) [poly(NIPAAm)] and a swollen heterogel, poly(N-isopropylacrylamide-co-vinyl-terminated dimethylsiloxane) [poly(NIPAAm-co-VTPDMS)]. The permeation data for dextran molecules up to the size of 43.5 A in radius show good agreement with the values predicted from the model.