Echocardiographic evidence of pericardial effusion in severe chronic pulmonary hypertension.
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Biomedical subjects
Publications and source records attributed to L Olson.
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By using stereotaxic surgical techniques, ventral mesencephalic tissues from aborted human fetuses of 8 to 10 weeks' gestational age were implanted unilaterally into the striata in two patients with advanced Parkinson's disease. The patients were treated with a cyclosporine, azathioprine, and steroid regimen to minimize the risk for graft rejection. They were examined for 6 months preoperatively and 6 months postoperatively and continued to receive the same doses of antiparkinsonian medication. There were no significant postoperative complications. No major therapeutic effect from the operation was observed. However, in the clinical tests, both patients showed small but significant increases of movement speed for repeated pronation-supination, fist clenching, and foot lifting. The rate of walking also increased in the one patient tested. For both patients, there was an initial worsening postoperatively, followed by improvement vs preoperative performance at 1 to 3 months. Both patients also showed significant improvement in the magnitude of response to a single dose of levodopa (L-dopa), but there was no increase in the duration of drug action. The motor readiness potential increased in both patients postoperatively, primarily over the operated hemisphere. Neurophysiological measurements also showed a more rapid performance of simple and complex arm and hand movements on the side contralateral to transplantation in one patient at 5 months postoperatively. Positron emission tomography demonstrated no increased uptake of 6-L-(18F)-fluorodopa in the transplanted striatum at 5 and 6 months. Taken together, these results suggest that the fetal nigral implants may have provided a modest improvement in motor function, consistent with the presence of small surviving grafts. Although our results support further scientific experimentation with transplantation in Parkinson's disease, widespread clinical trials with this procedure are probably not warranted at this time.
Sequence data for the mature nerve growth factor (NGF) protein and its precursor are available from molecular cloning of the NGF gene in several species, including mice, humans, rats, and chickens. Hydrophilicity analysis of the predicted rat and chicken prepro-NGF was carried out to locate putative antigenic determinants. Eight peptides were selected and synthesized based on hydrophilicity profiles. Two peptides represent sequences in the rat (and mouse) pro-NGF, one peptide (our peptide P3) represents a highly conserved region of the mature NGF protein (identical in humans, mice, rats, and chickens), two peptides are specific for the mature chicken NGF, and the remaining three peptides are specific for the mature rat NGF (each with only one amino acid substitution compared with corresponding segments of the mouse NGF). For immunization, the peptides were conjugated to keyhold limpet hemocyanin and used to produce antisera in rabbits. After bleeding, peptide-specific antibodies were purified on affinity columns prepared by coupling each of the synthetic peptides. The different peptide antisera and affinity-purified antibodies then were characterized by enzyme-linked immunoassay (ELISA) and immunohistochemistry of the male mouse submandibular gland, a rich exocrine source of NGF. ELISA analysis showed that all peptide antisera bound two to four orders of magnitude better than normal rabbit serum to a coat of their proper peptide. The higher binding was retained by the purified peptide antibodies compared with normal rabbit immunoglobulin. Specific tests, in which one peptide antiserum was checked against different peptide coats in the ELISA, also showed two to four orders of magnitude higher binding of antibodies to the proper synthetic peptide. The peptide antibodies also were tested for their ability to bind to native mouse beta NGF coated to the immunoplates. Only antibodies raised to the conserved P3 peptide recognized native NGF to an extent similar to that obtained with polyclonal anti-NGF antibodies. Conversely, P3 was well recognized by several different NGF antisera. Immunohistochemically, both peptide antisera against the pro-NGF stained the perinuclear cytoplasm in the basal part of the cells of the granulated convoluted tubules in the mouse submandibular gland.(ABSTRACT TRUNCATED AT 400 WORDS)
On the basis of animal studies, grafts of fetal human dopaminergic cells have been suggested as a therapy for Parkinson's disease. The purpose of this study was to characterize the ultrastructure and immunocytochemistry of human ventral mesencephalic xenografts placed into the catecholamine-depleted striata of athymic "nude" rats. Human fetal tissue was obtained from tissue fragments derived from elective abortions during the first trimester of pregnancy. Small pieces of the basal mesencephalon were grafted into the catecholamine-depleted striata of four athymic nude rats. The rats were allowed to survive from 3 to 6 months after grafting; following fixation, the striatal tissue containing the grafts was labeled with antibodies against tyrosine hydroxylase and serotonin. Immunocytochemistry revealed tyrosine-hydroxylase-like-immunoreactive (THLI) and serotoninlike-immunoreactive (5HTLI) cell bodies within the human grafts. Both 5HTLI and THLI fibers crossed the graft-host interface and innervated the previously lesioned striatum. Both types of fibers also entered the host cortex from the adjacent human graft. At the ultrastructural level, THLI and 5HTLI fibers and synaptic terminals were observed in the host neuropil. THLI and 5HTLI dendrites and axon terminals were also observed in the neuropil of the grafts themselves. THLI axon terminals are not normally present in the substantia nigra. The results of our study indicate that human xenografts can survive in the neuropil of the host striatum and form morphologically appropriate synapses within the host brain.
The effects of nerve growth factor (NGF) on developing central cholinergic neurons were studied using intraocular grafts of rat fetal (E17) basal forebrain tissue. Prior to grafting, grafts were incubated in NGF or saline. Transplants were allowed to mature for six weeks, receiving weekly intraocular injections of NGF or saline. Measurements of NGF levels in oculo after one single injection showed that NGF slowly decreases in the anterior chamber fluid, and after one week, low but significant levels were still present in the eye. Following pretreatment with diisopropylfluorophosphate (DFP), the cholinergic neurons in the grafts were analyzed using three morphological markers: antibodies to cholineacetyltransferase (ChAT), antibodies to acetylcholinesterase (AChE Ab) and acetylcholinesterase histochemistry (AChE). The transplants grew well and became vascularized within the first week. The growth of the NGF-treated basal forebrain grafts was significantly enhanced as compared to the growth of the saline-treated grafts evaluated with repeated stereomicroscopical observations directly through the cornea of the ether-anaesthetized hosts. The NGF-treated grafts contained almost twice as many cholinergic neurons seen with all the cholinergic markers used, as the saline-treated grafts. However, there was no difference in cholinergic cell density between the two groups. The morphology and size of an individual cholinergic neuron was similar in the two groups. The fiber density as evaluated with AChE-immunohistochemistry did not change after NGF-treatment. The DFP-treatment did not seem to affect the AChE-immunoreactivity since an extensive fiber network was found, whereas almost no fibers were seen using conventional AChE histochemistry. We have demonstrated that in oculo transplantation of basal forebrain is a useful model for examining in vivo effects of NGF on central cholinergic function. The marked volume increase of NGF-treated grafts and the unchanged density of cholinergic cells and terminals suggests, that NGF increases the survival of not only developing cholinergic neurons, but possibly other non-cholinergic neurons and non-neuronal cells as well. These results support the notion that NGF acts as a neurotrophic factor on cholinergic and possibly non-cholinergic cells in the central nervous system.
Intense labelling of secretory cells in the male mouse submandibular gland was observed after in situ hybridization using mouse nerve growth factor (NGF) cDNA probes. Under the same conditions, sparse less intensely labelled cells were also found in the sublingual gland. Hybridization to a chicken NGF cDNA probe gave weak labelling on the glands in accordance with a weak cross-hybridization between mouse NGF mRNA and chicken NGF cDNA probes, whereas no labelling was seen using pUC9 DNA as a hybridization probe. A combination of in situ hybridization and immunohistochemistry was also carried out on the same sections of submandibular gland. A good correlation was seen between actively synthesizing and intensely immunoreactive cells in the gland. The technique described here allows the detection of individual cells synthesizing relatively low levels of NGF. The combination of in situ hybridization and immunocytochemistry on the same section should be particularly useful in cases where NGF is transported away from its site of synthesis.
Growth of grafts of cortex cerebri, hippocampus, septum and cerebellum in oculo were significantly reduced in 16--17-month-old hosts as compared to growth in 3-month-old and 1.5-month-old rat hosts. (Host age is given as the age of the recipients at the time of grafting.) This growth difference was less pronounced in locus coeruleus grafts. The vascular network (as observed with laminin immunofluorescence) in cortex cerebri, hippocampus, cerebellum and septum grafts in 16--17-month-old hosts was abnormal with few thick-walled vessels in clusters as compared to the more 'normal' vascularization found in 1.5-month-old hosts with a high number of thin-walled blood vessels evenly distributed throughout the grafts. Grafts in the oldests hosts were markedly more gliotic than grafts in 1.5- and 3-month-old hosts as evaluated using immunofluorescence with antibodies against glial fibrillary acidic protein. Neurofilament immunoreactivity in the grafts seemed not to be influenced by host age. When a second cortex cerebri or hippocampus graft was placed into contact with a previously grafted locus coeruleus graft, the second graft grew less well in 16--17-month-old hosts as compared to 1.5-month-old hosts. When cortex cerebri was added to a previously grafted cortex cerebri graft, the second graft in both 16--17- and 3-month-old hosts grew to larger sizes than the corresponding single cortex grafts, although the growth differences between the two groups of hosts described above were still maintained. Thus, cortex grafts in 16--17-month-old hosts still have the ability to become trophically stimulated. The vascularization of the second graft in both groups was almost normalized and the gliotic reaction was less pronounced in the second grafts in both groups as compared to the single cortex grafts. In conclusion, the present results indicate that host age affects growth and morphology of intraocular single grafts from several brain regions. Using double grafts of cortex cerebri it was shown that grafts in 16-17-month-old hosts still had the capacity to become trophically stimulated. Data on brain transplants in older hosts are important in view of clinical possibilities to use transplantation strategies to counteract the symptoms of neurodegenerative diseases, which usually occur in old patients.
Glioblastoma cells from three established lines were transplanted in oculo and in cerebrum to rat hosts. A very low dose of Cyclosporine A was found sufficient to allow graft survival whereas grafts in non-immunosuppressed animals did not survive. Moderate immunosuppression permitted long term graft survival without aggressive growth of glioblastoma cells, creating a protracted course during which neither cell rejection nor tumor proliferation occurred. A tumor reminiscent of a glioblastoma was only seen in one animal on high immunosuppression. Phenotypic changes such as the induction of glial fibrillary acidic protein (GFAP) production and an astrocytic morphology were observed in the cells growing in oculo but not in cerebrum. Vascularization was easily demonstrated with laminin immunofluorescence but the endothelial proliferation typical of glioblastomas was not seen.
The effects of nerve growth factor and antiserum against nerve growth factor on cortical cholinergic projection areas in the central nervous system and cerebellum were evaluated using intraocular grafts of cortex cerebri, hippocampus and cerebellum in rat hosts receiving injections into the anterior chamber of the eye of nerve growth factor (at transplantation, 5 and 10 days after transplantation) or antiserum to nerve growth factor (every 5 days). The controls received cytochrome c or preimmune serum. Growth of grafts was followed by repeated observations directly through the cornea of the host using a stereomicroscope. Nerve growth factor-treated grafts of cortex cerebri and hippocampus grew significantly smaller as compared to the corresponding control grafts. In one experiment, growth of cytochrome c and saline-treated cortex cerebri was compared and no difference in growth was found. Growth of nerve growth factor-treated cerebellar grafts did not differ significantly from growth of cytochrome c-treated grafts. Morphological analysis using Nissl-staining, antibodies to glial acidic fibrillary protein to evaluate the degree of gliosis and antiserum to neurofilament as a neuronal marker did not reveal any marked differences between nerve growth factor- and cytochrome c-treated grafts. Cortical grafts receiving anti-nerve growth factor antiserum by injection or by immunizing host rats against nerve growth factor showed similar growth to the controls. Similarly, grafts of fetal hippocampus to rats immunized with nerve growth factor were not significantly different from grafts to host rats immunized with cytochrome c. We conclude that exogenous nerve growth factor affects the development of grafted cortex cerebri and hippocampus. The fact that these cortical areas stop growing earlier in the presence of nerve growth factor without the grafts showing evidence of disturbed glial or neuronal populations compared to control grafts indicates that nerve growth factor acts to induce overall/premature differentiation and maturation. The mechanism for this whether or not it is receptor-mediated and which cells are primarily affected by nerve growth factor is not yet known.
In situ hybridization histochemistry and RNA blot analysis were used to study expression of nerve growth factor receptor (NGF-R) mRNA in rat spinal cord motoneurons. The results show that NGF-R mRNA is expressed at high levels in rat spinal cord motoneurons at the time of naturally occurring cell death. This expression is sustained, but reduced, during synapse formation and is subsequently greatly reduced in the adult spinal cord. A unilateral crush lesion of the sciatic nerve resulted in an 8-fold increase in NGF-R mRNA in adult rat spinal cord motoneurons 3 days after lesion, compared with the nonlesioned side. NGF-R mRNA induction was even more pronounced 7 and 14 days after lesion, reaching levels 12 times higher than those on the nonlesioned side. However, 6 weeks after lesion, when the motor function of the leg was largely restored, NGF-R expression had decreased to levels similar to those on the contralateral side. We therefore suggest that NGF-R mediates a trophic or axonal guidance function for developing and regenerating spinal cord motoneurons.
Human fetal hippocampal tissue from normal women was obtained following elective abortion in the 8th to the 11th week of gestation. The hippocampal tissue was transplanted to the anterior chamber of the eye of adult athymic nude rats, where it was allowed to develop for up to 9 months before histological and electrophysiological evaluation. The transplants were revascularized from the host iris and many grew extensively in oculo. Large neurons were present in all transplants. Immunohistochemical studies revealed glutamic acid decarboxylase-containing terminals and clusters of gamma-aminobutyric acid-positive nerve cell bodies within the transplants, as well as scattered tyrosine hydroxylase-positive and acetylcholinesterase-containing fibers. Single neurons recorded extracellularly from transplants 4-9 months in oculo showed a slow spontaneous discharge, with both complex and single action potentials. Stimulation of the transplant surface evoked a small initial wave followed by a larger and longer-lasting field potential, similar to that seen in hippocampus in situ. A conditioning-testing paradigm was used to evaluate the presence of inhibitory circuitry in the hippocampal transplants. Significant suppression of the evoked test response was seen with interstimulus intervals ranging from 20 to 500 ms. Superfusion of enkephalin (100-300 nM) or penicillin (1600 U/ml) increased slow-wave activity, as did tetanic electrical stimulation. These treatments appeared to generate ictal-like activity, which in some cases persisted as interictal spikes. Illumination of the retina also increased neuronal activity, presumably by reflex activation of cholinergic afferents from the parasympathetic innervation of the iris. Taken together, our data suggest that fragments of hippocampus from aborted first trimester human fetuses, grafted to the eye chamber of rodent hosts, develop many organotypic histological and physiological features. This preparation may provide a unique means for the study of neurobiological properties of human brain in both normal and disease states.
The rat beta nerve growth factor (NGF) gene was inserted into a mammalian expression vector and cotransfected with a plasmid conferring resistance to neomycin into mouse 3T3 fibroblasts. From this transfection a stable cell line was selected that contains several hundred copies of the rat NGF gene and produces excess levels of recombinant NGF. Such genetically modified cells were implanted into the rat brain as a probe for in vivo effects of NGF on central nervous system neurons. In a model of the cortical cholinergic deficits in Alzheimer disease, we demonstrate a marked increase in the survival of, and fiber outgrowth from, grafts of fetal basal forebrain cholinergic neurons, as well as stimulation of fiber formation by intact adult intrinsic cholinergic circuits in the cerebral cortex. Adult cholinergic interneurons in intact striatum also sprout vigorously toward implanted fibroblasts. Our results suggest that this model has implications for future treatment of neurodegenerative diseases.
The process of regeneration of rat dorsal root ganglion cells was investigated by scanning and transmission electron microscopy and compared with the process of in vitro neurite formation. After disruption of the granular reticulum, numerous microtubules appeared in the perinuclear cytoplasm. Many thin, regenerating nerve fibers were found at the suture line adjacent to collagen fibers. Subsequently, the number of cytoplasmic neurofilament bundles increased and many of the regenerated nerves attached to the suture line. By the eighth week after experimental injury, the granular reticulum had reconstituted in the cytoplasm and the regenerated nerves resembled those of control animals, although the fiber arrangement was somewhat irregular. The process was almost identical to that of in vitro neurite formation, although the time course was much slower. Structural proteins, such as actin, tubulin, and neurofilament triplet, appeared to form similarly in neuronal regeneration and in vitro neurite formation. The results also suggest that microtubules are essential for nerve regeneration as well as neurite formation and that components of the neuronal microenvironment, such as collagen fibers and migrating cells, play crucial roles in nerve regeneration.
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Human fetal mesencephalic tissue obtained from elective first-trimester abortions was grafted to 6-hydroxydopamine-denervated striatum of athymic (nude) rats. After 3-6 months, the transplants were evaluated by light and electron microscopy using antibodies against tryosine hydroxylase (TH), human specific Thy-1 (Thy-1), 5-hydroxytryptamine (5-HT), and laminin. In vivo chronoamperometric studies of K+-induced release of electroactive species were done prior to the histochemical evaluations. At the light microscopical level, Thy-1-immunoreactivity was evenly distributed throughout the entire transplants. Thy-1-immunoreactive nerve fibers were observed radiating from the graft into the host striatum. In sections that were double-stained with antibodies against Thy-1 and TH, such nerve fibers contained both markers. Also 5-HT-immunoreactive cells were found in the grafts with processes both in the grafts and radiating into host neuropil. Laminin immunohistochemistry showed an even distribution of capillaries in the graft with less density than in host brain, suggesting immaturity of graft tissue. At the ultrastructural level, TH-immunoreactive axons made symmetric contacts with unlabeled dendritic shafts and dendritic spines within the host brain. A few asymmetric contacts with TH-immunoreactive axons were seen. 5-HT-immunoreactive terminals made both symmetric and asymmetric contacts with unlabeled dendritic shafts and spines. In vivo chronoamperometry using local application of K+ revealed average signals that were lower on the transplanted side than in control striatum. However, close to the grafts significant amounts of the K+-evoked signal amplitudes were as large as 1.3 microM, and the ratio of the reduction to oxidation currents suggested release of a mixture of dopamine and 5-HT. Taken together, this study shows that human fetal mesencephalic tissue pieces survive grafting into nude rats, develop normal vascularization, and express coexistence of TH- and Thy-1-immunoreactivity. Human TH- and 5-HT-immunoreactive nerve fibers form synapses in host striatum and release monoamine neurotransmitters.
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We tested the hypothesis that the pathogenesis of human idiopathic membranous glomerulonephritis is similar to that of Heymann glomerulonephritis, a model of membranous glomerulonephritis induced in rats by immunization with renal brush border preparations; the characteristic subepithelial deposits result from interaction of antibodies with a brush border antigen (gp330) expressed on the plasma membrane of glomerular visceral epithelial cells (GEC), followed by redistribution and shedding of gp330 immune complexes. The experiments were performed in cultured glomerular visceral epithelial cells, in living monkeys and rats, and in isolated perfused human, monkey, and rat kidneys. Antigens from plasma membranes of human renal brush border vesicles (HBBV) and GEC vesicles (HGECV) and their corresponding polyclonal and monoclonal antibodies reactive with human and monkey GEC were prepared. First, polyclonal antibodies to HGECV bound diffusely to cultured GEC; monoclonal antibody 8G5, recognizing a 60-kDa protein, mainly bound to the coated pits and apical invaginations; both polyclonal HGECV and 8G5 monoclonal antibodies induced antigen redistribution (capping) at 37 degrees C. Second, monkeys were actively or passively immunized, and isolated human and monkey kidneys were perfused with the antibodies. Active immunization with HBBV induced tubular immune deposits, whereas active immunization with HGECV did not provoke renal lesions. After passive immunization HBBV and HGECV antibodies bound diffusely to glomerular cells, and subepithelial deposits were observed during the autologous phase; in contrast, 8G5 induced early (day 3) granular deposits. Third, fine granular deposits developed in glomeruli of human and monkey kidneys perfused for 4 hours at 37 degrees C with 8G5; these deposits were more difficult to detect by electron microscopy than those occurring in kidneys of Lewis rats perfused with sheep antiHBBV. The results show that some antibodies redistribute antigens at the surface of human and monkey GEC in vitro, in vivo, and ex vivo and induce formation of granular deposits in human glomerular capillary walls. Failure to induce more severe lesions in human and monkey kidneys may be ascribed to lack of GEC antigens comparable to rat gp330, insufficient cross linking by monoclonal antibody, lack or insufficient concentration of epitope-specific antibodies, insufficient time of kidney perfusion, or a combination of these factors.