Biomedical subjects

I Date

Publications and source records attributed to I Date.

At least 73 records · Page 4Linked to original sources

PubMed1993

The influence of donor age on cografting of adrenal medulla with pretransected peripheral nerve.

Pretransected peripheral nerve has been demonstrated to enhance the survival of cografted adrenal medullary chromaffin cells and the recovery of host dopaminergic (DA) systems in animal models of Parkinson's disease. In the present study, we examined the effect of donor age on survival of cografted chromaffin cells. Adrenal medulla and pretransected peripheral nerve from young (1-month-old) or aging (12-month-old) donors were cografted into the striatum of MPTP-treated young (2-month-old) C57/BL mice. Although chromaffin cell survivability was increased by cografting with pretransected peripheral nerve despite donor age, survivability of chromaffin cells from aging donors was less than that using young donors. Image analysis of striatal DA fibers and chemical analysis of striatal DA showed that cografting with pretransected peripheral nerve enhanced the recovery of striatal DA systems more prominently than adrenal grafting alone. However, this effect was less in mice receiving aging donor tissues compared with mice receiving young donor tissues.

Adrenal Medulla↗

PubMed1993

Enhanced recovery of the nigrostriatal dopaminergic system in MPTP-treated mice following intrastriatal injection of basic fibroblast growth factor in relation to aging.

Studies have suggested that the restorative effects of adrenal medullary chromaffin cell grafts in animal models of Parkinson's disease may be related to trophic factors contained within the chromaffin cells. Basic fibroblast growth factor (bFGF) is present in chromaffin cells and has been shown to exert trophic effects on dopaminergic neurons in vitro. Basic FGF was stereotaxically injected into the striatum of young (2-month-old) and aging (12-month-old) C57BL/6 mice which had been treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) 1 week earlier. MPTP treatment reduced tyrosine hydroxylase (TH)-immunoreactive (IR) fibers in the striatum and striatal dopamine (DA) concentration in both the young and older mice 5 weeks later. Computerized image analysis of striatal DA fibers in young mice treated with bFGF showed significant recovery of DA fibers up to 600 microns from the injection site 5 weeks after MPTP administration. Striatal DA fibers in older mice treated with bFGF showed significant recovery only up to 300 microns from the injection site, and the degree of recovery was very limited compared with young mice. HPLC analysis of DA concentration revealed that striatal DA in young mice recovered significantly when treated with bFGF, but no significant recovery was observed in older mice. It is concluded that bFGF enhances the recovery of striatal DA systems from MPTP toxicity both in young and in older mice, but that such benefits are very limited in older mice.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1993

Suppression of immunorejection against rat fetal dopaminergic neurons in a mouse brain by 15-deoxyspergualin.

In this study, the immunosuppressive effect of 15-deoxyspergualin (DSG) on the survivability of rat embryonic dopaminergic neurons grafted into the lateral ventricle of adult mice was investigated. DSG was administered daily in dose of 5 mg/kg for 2 weeks postgrafting, commencing on the day of transplantation, in the immunosuppressant-treated groups. Animals were then allowed to survive for 2 to 4 weeks after transplantation. Histological analysis revealed that most of transplanted rat fetal neural tissue was destroyed and scavenged in 2 weeks after transplantation in the non-immunosuppressed group. However, a large number of tyrosine hydroxylase (TH)-positive grafted neurons survived and grew postgrafting in the brain of the host administered with DSG even if they suffered from T lymphocyte infiltrations visualized by cytotoxic T cell immunohistochemistry. The results thus indicated that DSG is an potent immunosuppressant in neural transplantation as well as in transplantation of other organs in animals. It seems to be able to block, at least in part, the ability of mature specific cytotoxic T cells to lyse their targets.

Animals↗

PubMed1993

Long-term outcome in surgically treated spina bifida cystica.

This report describes the long-term operative outcome of 72 patients with spina bifida cystica. The period of follow-up was between 4 and 20 years. In our series, 17 patients died, with the mortality rate increasing as the lesions were more rostral. All cases involving only a meningocele are living without handicap. The cases of spina bifida cystica with hydrocephalus had higher morbidity and mortality when compared to those without hydrocephalus. We conclude that the rostro-caudal location, the content of the sac, and whether there is associated hydrocephalus are important factors influencing the long-term prognosis of spina bifida cystica.

Child↗

PubMed1993

Long-term outcome in surgically treated encephalocele.

This report describes long-term operative outcome of 24 cases with occipital encephalocele. The follow-up periods are between 4 and 20 years. Of the 24 patients with occipital encephalocele, two have died. Of the 22 living patients, 16 are living without neurological deficit, while six are disabled mentally and/or physically. Four cases of encephalocele developed hydrocephalus, and two of them died while the other two are still living with severe handicap. The presence of gross brain tissue in the sac of encephalocele and the size of the sac were also unfavorable factors for the prognosis. We conclude that the size and the content of the sac and associated hydrocephalus are the important factors that influence the long-term prognosis of occipital encephalocele.

Encephalocele↗

PubMed1993

Long-term effects of cografts of pretransected peripheral nerve with adrenal medulla in animal models of Parkinson's disease.

Trophic factor supplementation has been reported to enhance the survivability of grafted adrenal chromaffin cells. Because the content of nerve growth factor in the distal stump of a pretransected peripheral nerve increases markedly 1 day after transection, we injected cografts of adrenal medulla with pretransected peripheral nerve into the striata of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice and performed follow-up histological and neurochemical analyses over a 12-month period. Adrenal medullary chromaffin cells cografted with pretransected peripheral nerve survived better than in adrenal grafts alone at 1, 3, and 12 months after transplantation. Host dopaminergic fiber recovery adjacent to the grafts was more prominent in mice with cografts than in mice with adrenal grafts alone at 1 and 3 months after transplantation. Twelve months after transplantation, however, there was no significant difference between the two groups of animals because of the natural recovery of intrinsic dopaminergic fibers from MPTP toxicity. Dopamine concentration in the striata of cografted mice was higher than in mice with adrenal grafts alone at 1 month after transplantation. At 3 and 12 months after transplantation, the natural recovery of dopamine concentration from MPTP toxicity was apparent in both groups of animals and no significant difference was observed between the groups. We conclude that adrenal medullary chromaffin cells can survive for at least 12 months after grafting when cografted with pretransected peripheral nerve. Cografts enhanced the recovery of the host nigrostriatal dopaminergic system up to 3 months after transplantation, but this enhancement was not apparent at 12 months because of the natural recovery of dopaminergic fibers from MPTP toxicity.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1992

Age-related decline in the dopaminergic nigrostriatal system: the oxidative hypothesis and protective strategies.

The anatomical and metabolic deterioration of the dopaminergic (DA) nigrostriatal system with age has been hypothesized to occur due to autodestruction by reactive oxygen intermediates derived from oxidative metabolites of DA. We hypothesized that treatment with a presynaptic agonist to diminish DA turnover should confer a protective effect. Pergolide mesylate, a potent D2 agonist with predominantly presynaptic action, when given in the diet (0.5 mg/kg/day) to male Fischer 344 rats from 3 months of age to 26 months of age, preserved the integrity of both cell bodies and terminals of the nigrostriatal system, partially reversed the age-related decline in DA uptake, and had no adverse effects on behavior or postsynaptic DA receptors on striatal neurons compared with age-matched, pair-fed control rats. As a counterpart to this strategy, L-dopa administration (50 mg/kg) to adult male Fischer 344 rats with unilateral nigrostriatal lesions using 6-hydroxy-dopamine, and subsequent fetal mesencephalic grafts resulted in stunted size and neurite outgrowth, diminished tyrosine hydroxylase (TH) expression, diminished behavioral recovery, and diminished ability to reverse lesion-induced D2 receptor changes, compared with saline-treated rats with the same lesion and subsequent graft. This toxic effect, although not seen in intact nigrostriatal systems, may indicate L-dopa toxicity on transplanted DA cells, or on DA cells maximally activated to recover from insult. In 3-month-old male C57BL/6 mice with N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) lesions, spontaneous recovery of the damaged DA nigrostriatal system was seen within 12 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1992

[Cool storage of fetal rat brain for neural transplantation].

The availability, storage and transportation of donor tissue are major practical problems associated with the potential use of grafted neural cell replacements in neurodegenerative diseases. The capacity to collect and maintain viable fetal neural tissue would facilitate possible clinical applications, and provide opportunities to study various neural diseases. In the present study, we examined the effect of cool storage on the survivability of intraventricular rat fetal ventral mesencephalic grafts (gestational days 15). In all experiments, fetal ventral mesencephalons were dissected out under a dissecting microscope in calcium-free magnesium-free buffer (CMF: 0.15 M NaCl, 0.008 M Na2HPO4, 0.0027 M KCl, 0.0015 M KHPO4, 0.026 M NaHCO3, with 0.1% glucose, 100 micrograms/ml streptomycin, 2.5 micrograms/ml fungizone). Fetal mesencephalic tissue was grafted into the lateral ventricle following pregraft refrigeration in calcium-free magnesium-free buffer at 4 degrees C. Fetal mesencephalic tissue was hibernated for 5, 12, 16, 20, 24, 28, 32 hours (group A, B, C, D, E, F and G, respectively). As a control group, fetal mesencephalic tissue was grafted into the lateral ventricle immediately after dissection. Grafted fetal mesencephalic tissue which had been hibernated for 16 hours or less survived well. There were no significant decreases in the size of grafts among group A, B, C and the control group. In group A, B, C and the control group, clusters of TH-positive neurons and dense networks of neuritic profiles within the grafts provided a morphological appearance reminiscent of the dendritic bundles that characterize the zone reticulate of the substantia nigra in situ.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

[Intrathecal dissemination of meningiomas; a case report].

A case of the cytologically verified intrathecal dissemination of benign meningiomas was reported. A 36-year-old man was admitted to our hospital because trans-sphenoidal surgery was planned for the repair of CSF rhinorrhea caused by a recurrent pituitary adenoma. The CT scan demonstrated incidental multiple tumors spread throughout in the pontomedullary and ambient cisterns. The head and spinal MRI showed more than fifteen small tumors in the posterior fossa and the thoracic spinal canal. CSF cytology revealed benign fibroblastic or meningotheliomatous meningioma with whorl formation and psammoma body. Several comments were made on the mechanism of the intrathecal dissemination of the meningiomas.

Adult↗

PubMed1991

The effect of a new immunosuppressive agent, FK-506, on xenogeneic neural transplantation in rodents.

This study examines the effect of a novel immunosuppressive agent FK-506 (FK) on the survivability of embryonic (E14) rat ventral mesencephalic tissue after intracerebral grafting to the lateral ventricle of adult mice. The recipient mice were given FK in doses of 10 mg/kg or 1 mg/kg for 2 weeks postgrafting, at which time they were sacrificed and histologically processed except for one group of animals on the high dose (10 mg/kg). In this group most animals died from side effects of the drug during the following days. Only the mice receiving the high dose of FK displayed healthy grafts without signs of rejection.

Animals↗

PubMed1991

The nigrostriatal dopaminergic system in MPTP-treated mice shows more prominent recovery by syngeneic adrenal medullary graft than by allogeneic or xenogeneic graft.

Following systemic injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), young (2-month-old) C57BL/6 mice show decreased dopaminergic (DA) nigrostriatal fibers and DA concentration in the striatum. We transplanted syngeneic, allogeneic and xenogeneic adrenal medullary grafts into the striatum of the MPTP-treated young mice and compared the survivability of grafted chromaffin cells and the recovery of intrinsic host DA fibers using computerized image analysis of tyrosine hydroxylase (TH)-immunoreactive (IR) fibers and high performance liquid chromatography with electrochemical detection (LCEC). The grafted syngeneic adrenal chromaffin cells survived better than allogeneic or xenogeneic chromaffin cells, and host DA nigrostriatal fiber recovery was more prominent in mice with a syngeneic graft than in mice with an allogeneic or xenogeneic graft. However, the degree of host fiber recovery in mice with allogeneic or xenogeneic mice was greater than in mice with a sham operation alone, even though the allografts and xenografts had no surviving chromaffin cells. Allografts and xenografts showed prominent rejection responses, with T lymphocyte infiltration in addition to macrophages. We conclude that a syngeneic adrenal graft survives better than an adrenal allograft or xenograft and promotes recovery of the intrinsic host nigrostriatal DA fibers. We also conclude that grafted chromaffin cell survivability influences the degree of host DA fiber recovery following MPTP depletion. Adrenal medullary grafts to Parkinsonian patients are currently under way in a large number of hospitals; we suggest that greater attention be paid to methods which lead to enhanced survival of the grafted chromaffin cells, since survivability might be closely related to the functional recovery of these patients.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1991

Stereotaxic injection of GD1a ganglioside induces limited recovery of striatal dopaminergic system in MPTP-treated aging mice.

The systemic administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to young (2 months old) and aging (12 months old) C57BL/6 mice (4 x 20 mg/kg i.p. given 12 hr apart) reduced tyrosine hydroxylase (TH)-immunoreactive (IR) fibers in the striatum and reduced dopamine (DA) concentration to 35% of controls in young and 22% of controls in aging mouse brain 5 weeks after administration. Stereotaxic injection of GD1a ganglioside (3 x 100 micrograms, 5 days apart) into the striatum of MPTP-treated young mice restored striatal DA concentration to 52% of the control concentration 5 weeks after MPTP injection. Similar injections of GD1a ganglioside restored striatal DA concentration of MPTP-treated aging mice to only 31% of the control concentration. Immunocytochemical analysis showed significant recovery of TH-IR fibers in the striatum of MPTP-depleted young mice treated with GD1a ganglioside, while TH-IR fibers in the striatum of MPTP-depleted aging mice treated with GD1a ganglioside showed less recovery. We conclude that treatment of MPTP-depleted aging mice with GD1a ganglioside results in more limited recovery in the nigrostriatal DA system than in young mice.

Aging↗

PubMed1991

A monoclonal antibody that labels Purkinje cells in the rat cerebellum.

A monoclonal antibody (MAb-1D10), generated by immunizing Balb/c mice with homogenized bovine retinal tissue, labeled the Müller cells in the bovine retina and the Purkinje cells of the rat cerebellum. In the neonatal rat cerebellum, immunoreactivity for MAb-1D10 appeared first in the ventral regions of vermis (lobuli I-III and IX-X) on the 11th postnatal day (P11), while in the dorsal vermis and cerebellar hemisphere, the immunoreactive Purkinje cells were detected on P13. Western blotting analysis disclosed that MAb-1D10 recognized bovine retinal polypeptides with mol.wt. of 48 kDa. Transplantation of the rat cerebellar primordia on 16th embryonic day demonstrated large and round cells with a linear arrangement in the grafts surviving well in the host rat striatum after 50 days of the grafting. These large cells were immunohistochemically labeled by MAb-1D10. No other cells in both the graft and the host striatum were immunoreactive to the MAb.

Animals↗

PubMed1991

[The effect of a new immunosuppressive agent, FK-506, on xenogeneic neural transplantation in rodents--comparison with cyclosporin A].

The present study was performed to compare the immunosuppressive effect of FK-506 (FK) with cyclosporin A (CyA) in xenogeneic neural transplantation in rodents. The solid grafts of embryonic ventral mesencephalic tissue from 14-day rat embryos were transplanted into the right lateral ventricle of 20 mature male mice using a stereotactic approach, and the mice were sacrificed 14 days after transplantation. The removed brains, which were sectioned coronally, were stained with antibodies against glial fibrillary acidic protein (GFAP), Lyt-2 or tyrosine hydroxylase (TH) in addition to hematoxylin-eosin and Nissl stainings. The subcutaneous (s.c.) administration of FK at a dose of 10.0 mg/kg daily for 14 days enabled the neural xenografts to survive and grow (n = 5), although all of the neural xenografts treated with CyA at a dose of 10.0 mg/kg s.c. (n = 5) or FK at a dose of 1.0 mg/kg s.c. (n = 5) daily for 14 days and ones treated without such an immunosuppressive agent (n = 5) were rejected by immunological reactions. We conclude that FK is a more powerful immunosuppressive agent than CyA in xenogeneic neural transplantation as well as in cardiac and renal allograftings.

Animals↗

PubMed1991

[Cografting technique in the treatment of Parkinson's disease].

Intracerebral grafting of dopamine containing adrenal chromaffin cells to the brain of experimental animals can ameliorate the symptoms of experimentally induced Parkinson's disease. Clinical trials of adrenal autograft to the patients with Parkinson's disease are on-going with variable results and autopsy cases show poor survivability of grafted chromaffin cells. The present study was performed to determine if transected peripheral nerve could provide sufficient nerve growth factor to enhance the survivability of grafted chromaffin cells. Survivability of grafted chromaffin cells increased when cografts with sciatic nerve were performed, and host dopaminergic fiber recovery was more prominent in mice with cografts than in mice with adrenal grafts alone. Although this enhanced survivability and recovery of host fibers were seen in cografted mice from aging donors, the degree of these effects was greater in cografted mice from young donors. Considering these results, we suggest that methods to increase the survivability of grafted chromaffin cells be explored more deeply because such survivability might be closely related to the functional recovery of patients with Parkinson's disease, using this grafting procedure.

Adrenal Medulla↗

PubMed1991

[Cografts of adrenal medulla and peripheral nerve in a mouse model of Parkinson's disease].

Systemic injection of MPTP damages the nigrostriatal dopaminergic system in C57B1/6 mice. Since transected peripheral nerve segments are known to produce nerve growth factor, we performed adrenal medullary grafts or cografts of adrenal medulla and sciatic nerve into the striatum of MPTP-treated mice, and compared the survivability of grafted chromaffin cells and the recovery of intrinsic host dopaminergic fibers. Survivability of grafted chromaffin cells increased when cografts with sciatic nerve were made, and host dopaminergic fiber recovery was more prominent in mice with cografts than in mice with adrenal grafts alone. The degree of recovery of host intrinsic dopaminergic fibers was greater in younger host striatum than in older host striatum. We conclude that cografts of adrenal medulla and sciatic nerve increase the survivability of grafted chromaffin cells better than adrenal medullary grafts alone, and that survivability of grafted chromaffin cells promotes host dopaminergic fiber recovery.

Adrenal Medulla↗

PubMed1991

[Mobile neurinoma of the cauda equina; a case report].

A case of mobile tumor of the cauda equina was presented with a brief review of factors relating to the mobility. A 66-year-old man was admitted to our hospital complaining of left lumbago aggravated by coughing or assuming the supine position. However, neurological examination failed to reveal any abnormalities. The initial myelography showed complete obstruction above the superior border of the L1 vertebra, while the second myelography showed the same obstruction, but it had moved upwards to the superior border of T12. Surgery revealed an elastic, soft tumor and cystic dilatation of the subarachnoid space above and below the tumor. The tumor was mobile but originated from a single elongated and tortuous nerve of the cauda equina. Pathologic examination revealed neurinoma.

Aged↗

PubMed1990

Cografts of adrenal medulla with peripheral nerve enhance the survivability of transplanted adrenal chromaffin cells and recovery of the host nigrostriatal dopaminergic system in MPTP-treated young adult mice.

Schwann cells from transected peripheral nerve segments are known to produce nerve growth factor (NGF). We performed adrenal medullary grafts or cografts of adrenal medulla and sciatic nerve into the striatum of MPTP-treated young adult mice, and compared the survivability of grafted chromaffin cells and the recovery of intrinsic host DA fibers using computerized image analysis of tyrosine hydroxylase (TH)-immunoreactive (IR) fibers and neurochemical analysis with high performance liquid chromatography (HPLC). Adrenal medullary chromaffin cells cografted with sciatic nerve survived better than those in adrenal grafts alone; host DA fiber recovery was more prominent in mice with cografts than in mice with adrenal grafts alone. A large number of TH-IR surviving cells in cografted mice showed long neuronal processes which were rarely seen in the mice receiving adrenal graft alone. We conclude that cograft of adrenal medulla and sciatic nerve promotes intrinsic host DA fiber recovery better than adrenal medulla grafts alone, and that survivability of grafted chromaffin cell may promote host DA fiber recovery. Adrenal medullary autografts have been used in patients with Parkinson's disease; we suggest that if this approach is to be used in the future, methods to increase the survivability of grafted chromaffin cells, such as co-grafting with pieces of peripheral nerve, be considered to enhance the survivability of the chromaffin cells, which might be closely related to the functional recovery of the patients by this grafting procedure. Of course, such strategies as the present cografting approach must be demonstrated to work in older animals using older donor tissue before proceeding to this next step in humans.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗