Biomedical subjects

J J Gilbert

Publications and source records attributed to J J Gilbert.

At least 19 recordsLinked to original sources

PubMed1992

Effect of anti-interferon-gamma and anti-interleukin-2 monoclonal antibody treatment on the development of actively and passively induced experimental allergic encephalomyelitis in the SJL/J mouse.

SJL/J mice challenged with myelin basic protein (MBP) in complete Freund's adjuvant (CFA) developed only mild chronic-relapsing experimental allergic encephalomyelitis (EAE) with very low incidence. However, treatment of challenged mice with anti-interferon-gamma (IFN-gamma) monoclonal antibody (mAb) determined severe disease in all cases. Similarly, in passive EAE, the addition of anti-IFN-gamma to the in vitro MBP-activated cells at the time of transfer led to significant disease exacerbation in all recipients. The disease enhancing effect was observed only when the mAb was given at the time of active challenge or of passive transfer, but not at later times. Anti-interleukin-2 (IL-2) antibody had only a marginal effect in the active induction, but drastically reduced the manifestations of passive EAE, even when mixed with a disease-enhancing dose of anti-IFN-gamma. These findings support the notion that IL-2 is required for disease induction whereas IFN-gamma plays a disease-limiting role early in the development of EAE.

Animals↗

PubMed1991

Cysts of the neuraxis of endodermal origin.

Five colloid cysts of the third ventricle were compared with two spinal enterogenous cysts to examine the hypothesis that these entities have the same origin from primitive endodermal tissue. All the lesions showed cuboidal and columnar epithelium with mucus containing goblet cells and cilia. Immunohistochemistry for cytokeratin, EMA and CEA was positive in all the colloid cyst and enterogenous cyst epithelium. S-100 was focally positive in three of the colloid and one of the enterogenous cysts while vimentin and GFAP were negative in both. The anatomical distribution of both colloid and enterogenous cysts is reviewed. An illustrative case of an identical cyst within the fourth ventricle is presented. This suggests that the similarities between colloid and enterogenous cysts and the presence of identical lesions along the neuroaxis indicate that these structures are derived from primitive foregut endoderm.

Adult↗

PubMed1990

NMR studies in experimental allergic encephalomyelitis: factors which contribute to T1 and T2 values.

To determine the factors which may alter NMR relaxation times in multiple sclerosis (MS) lesions we measured the proton T1 and T2, specific gravity (SG), and histology in the central nervous system (CNS; 13-19 levels per animal) in the myelin basic protein (MBP) and CNS-induced acute and relapsing EAE models in 44 juvenile Hartley guinea pigs. In the MBP model, T1 is unchanged but T2 is prolonged before symptoms and pathological changes occur. T2 remains prolonged during the acute phase of MBP-induced EAE. In the acute CNS model, T1 and T2 were not different from control despite advanced pathological changes of inflammation and demyelination and changes in specific gravity, indicating a marked change in tissue water content. No single variable, pathological or SG, could predict T1 or T2 values in the CNS-induced model. In active disease in the MBP model, when edema occurs in the presence or absence of parenchymal infiltration, T2 values are increased. However, as the factors which influence tissue NMR characteristics are complex in these MS models, it is likely difficult to infer specific pathological events from MRI findings in patients with MS.

Acute Disease↗

PubMed1990

Treatment of spinal cord-induced experimental allergic encephalomyelitis in the Lewis rat with liposomes presenting central nervous system antigens.

Chronic-relapsing experimental allergic encephalomyelitis (CR-EAE) in the Lewis rat, induced by the injection of spinal cord tissue in complete Freund's adjuvant (SC/CFA), was studied in vivo by treatment with liposomes containing central nervous tissue antigens, and in vitro by lymphocyte proliferation assays. Intracardiac administration of myelin basic protein (MBP) liposomes, galactocerebroside (GC) liposomes, or MBP + GC liposomes substantially reduced the clinical severity and/or delayed the onset of the initial phase of disease. Liposomes prepared from whole myelin provided even greater protection, and were effective at suppressing both the first disease episode and the relapses. These results indicate that while GC and MBP may play significant roles in the development of CR-EAE in the Lewis rat, immune responses to other antigens are probably also involved. Splenic and lymph node lymphocytes from MBP-GC liposome-treated rats, and splenic lymphocytes from cytochrome-GC (CYT-GC) liposome-treated rats, showed drastically reduced abilities to proliferate in response to MBP in culture. Spleen cells from both the MBP-GC- and CYT-GC-liposome-treated donors were able to actively suppress antigen-induced proliferation of MBP-primed lymphocytes. These findings suggest participation of both clonal anergy, and active suppressor cells in the liposome-mediated suppression of CR-EAE in the Lewis rat.

Animals↗

PubMed1990

Some clinical and pathologic observations on chronic myelopathy: a variant of multiple sclerosis.

Four patients with progressive demyelinating myelopathy with symptoms spanning six to 25 years are described. There was no clinical evidence of dissemination of lesions in the central nervous system. Radiological evidence of dissemination was present in two cases; in one this was absent at the time of presentation and was only demonstrated after six years of progressive unifocal disease. In one case, pathological examination revealed a solitary area of chronic demyelination. In all cases but one, oligoclonal bands were detected on cerebrospinal fluid (CSF) electrophoresis. Some cases of chronically progressive myelopathy result from focal demyelination in the absence of a second lesion demonstrable by clinical, radiographic or necropsy examination.

Aged↗

PubMed1990

The significance of myoclonic status epilepticus in postanoxic coma.

We report 11 adults who exhibited myoclonic status epilepticus (MSE) after cardiac arrest. Based on pathologic, electroencephalographic, and clinical evidence, we conclude that our patients died from the initial anoxic-ischemic insult rather than as a result of MSE. We suggest that the seizures in these nonsurvivors were self-limited events arising from lethal damage to neurons. Thus, in patients with bilaterally synchronous facial myoclonus, bilateral loss of pupillary or oculovestibular reflexes, and suppression and burst-suppression on EEG, it is not warranted to use anesthetic barbiturates to treat MSE.

Adult↗

PubMed1989

Chronic-relapsing experimental allergic encephalomyelitis in strain-13 guinea pigs: cell-mediated immunity and IgG isoelectric focusing in myelin basic protein-liposome-treated and untreated animals.

Juvenile strain-13 guinea pigs challenged with whole central nervous system (CNS) tissue in complete Freund's adjuvant (CFA) developed chronic-relapsing (CR) experimental allergic encephalomyelitis (EAE). The animals that recovered from the first clinical episode were divided into three groups. One group was left untreated, one group was treated with three intracardiac injections of 100 micrograms glutaraldehyde-fixed myelin basic protein (MBP)-liposomes (MBP-L-GA) given once a week, and one group was treated with cytochrome c-liposomes (CYC-L-GA). The animals treated with MBP-liposomes were very well protected against further relapses. In vitro proliferative responses of peripheral blood lymphocytes (PBL) were performed repeatedly on most animals. The lymphocytes exhibited excellent proliferative responses to MBP, proteolipid apoprotein (PLP) and whole myelin, as well as to purified protein derivative (PPD) and concanavalin-A (ConA). High proliferative responses were recorded over the entire period of observation which lasted 12-22 months, each time the animals were tested in remission or in full relapse. However, a sharp decrease in proliferative responses was observed in most animals when the assay was performed 24-48 h before to 24 h after entering a relapse. The results demonstrate the presence of long-term and sustained cell-mediated responses to two distinct neuroantigens, and show fluctuations of both neuroantigen-specific and nonspecific responses concordant with a well-defined phase of the disease. Isoelectric focusing and immunofixation was performed on sera and cerebrospinal fluids obtained at the time of sacrifice. The pattern showed clear oligoclonal IgG bands (OB) in the samples obtained from untreated, CYC-L-GA-treated as well as in the MBP-L-GA-treated animals.

Animals↗

PubMed1989

Jugular venous bulb catheterization in infants and children.

Cross-brain oxygen extraction may be altered by coma, hyperventilation, hypothermia, or barbiturates, and has been demonstrated in adults and more recently in children to be related to functional neurologic recovery after a variety of brain injuries. However, measurement of cross-brain oxygen extraction in children is currently not a part of routine clinical care, partly because there have been no published attempts relating the technique of jugular venous bulb (JVB) catheterization and its complication in children. We catheterized the JVB to measure cerebral venous oxygen content and calculate cross-brain oxygen extraction in 26 deeply comatose neonates and children ranging in age from a few hours to 14 yr. Bedside catheterization using the Seldinger technique was successful in 25 children, with standard venous cutdown necessary in the remaining child. All JVB catheterizations were performed with parental consent and during continuous monitoring of the intracranial (ICP) or fontanelle, as well as arterial, pressure. ICP was not significantly altered by the cannulation procedure in any of the children studied, although the cannulation occurred early in the child's course when ICP was well controlled. Inadvertent carotid artery puncture with bleeding controlled by local pressure occurred in four children, and catheter malposition was confirmed on lateral skull xray in two others. Jugular venous bulb catheters remained in place for 2 to 7 days (average 3) and malfunction or obstruction of the catheter did not occur. Organisms were grown from three of 26 catheter tips submitted for culture, with peripheral blood cultures also positive for the same organisms in two of these.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1989

Metastatic anaplastic oligodendroglioma.

We report 7 patients, ages 21 to 49 years, with systemic metastasis from anaplastic oligodendroglioma. Metastases developed in the scalp, cervical lymph nodes, bone, and other organs 1 to 76 months after the most recent surgery and 18 to 86 months after diagnosis. Systemic metastases responded to focal radiotherapy or nitrosourea-based chemotherapy for 6 to 18 months. Five patients have died, 4 to 24 months after the appearance of systemic metastases, all with progressive cerebral and systemic tumor. We observed 2 distinct patterns of spread of oligodendroglioma. Pattern 1, initial scalp or regional lymph node involvement followed by distant metastasis, was associated with multiple craniotomies. Pattern 2, distant metastasis without scalp or regional lymph node spread, was associated with early radiotherapy and chemotherapy. Longer-than-expected survival was not essential to metastasis. We speculate that anaplastic oligodendrogliomas possess special characteristics favoring metastasis and that early aggressive treatment alters the biology of this disease.

Adult↗

PubMed1988

Effect of treatment with glutaraldehyde-fixed myelin basic protein-liposomes on active induction and passive transfer of experimental allergic encephalomyelitis in Lewis rats.

Guinea pig myelin basic protein (MBP)-liposomes were prepared and fixed with 0.2% glutaraldehyde (GA). Lewis rats were treated with glutaraldehyde-fixed MBP-liposomes (MBP-L-GA) or with cytochrome-c-liposomes (CYC-L-GA), 7 days before and 7 days after challenge with MBP in CFA. Rats treated with MBP-L-GA, but not with CYC-L-GA, were very well protected against the clinical manifestations of EAE. The protection was better than that obtained after treatment with conventional MBP-liposomes (without glutaraldehyde). Furthermore, when grown in vitro for 72 hr in the presence of MBP, lymphocytes from rats treated with MBP-L-GA and challenged with MBP in CFA exhibited a marked decrease in their ability to transfer EAE to normal syngeneic recipients.

Animals↗

PubMed1988

Dementia, parkinsonism, and motor neuron disease: neurochemical and neuropathological correlates.

The neurochemical markers for the major neurotransmitter systems were measured in the brain of a patient who died with a dementia-parkinsonism-motor neuron disease (DPMN) syndrome complex. Moderate neuronal loss in the substantia nigra, spongiform changes in the frontal cortex, and moderate anterior horn cell loss throughout the spinal cord were observed. A severe nigrostriatal dopamine deficiency provides the basis for the observed parkinsonian features. The dementia is unexplained.

Caudate Nucleus↗

PubMed1988

Postnatal NMR changes in guinea pig central nervous system: potential relevance to experimental allergic encephalomyelitis.

The age of sensitization determines the clinical course of experimental allergic encephalomyelitis (EAE) in the guinea pig. Adult animals immunized with central nervous system (CNS) tissue develop acute, fulminant EAE, whereas a relapsing-remitting illness resembling multiple sclerosis occurs if sensitization occurs in the first 2 weeks of life. This study characterized the changes in the proton nuclear magnetic resonance (NMR) relaxometry and imaging of the CNS during the immediate postnatal period. T1 and T2 relaxation times in cerebral hemispheres and spinal cords of strain 13 guinea pigs were consistently prolonged at birth, progressively shortened in the first few weeks of life, and achieved adult levels by age 6 to 11 weeks. There were no age-dependent differences in T1 and T2 relaxation times and tissue specific gravity in either strain 13 or Hartley guinea pigs following immunization with complete Freund's adjuvant, an agent previously reported to disrupt the blood-brain barrier to IgG and albumin in strain 13 guinea pigs. The CNS of neonatal guinea pigs appeared well myelinated by light microscopy and there was no apparent difference in the extent of myelination between newborn and adult animals. Although it was possible to distinguish gray from white matter in the cervical spinal cord of newborn guinea pigs by magnetic resonance imaging (MRI) techniques, gray/white contrast was less satisfactory in the cerebral hemispheres until approximately 6 weeks of life when it was possible to differentiate gray matter, white matter, and cerebrospinal fluid. This study indicates that NMR relaxation times change during early postnatal life, at a time corresponding to the unexplained differences in susceptibility to an immune challenge. These developmental changes appear to be independent of the degree of CNS myelination.

Aging↗

PubMed1988

Jakob-Creutzfeldt disease associated with Wernicke encephalopathy.

Wernicke disease (WD) is a complication of alcoholism and malnutrition and usually presents acutely and is characterized by disturbances of consciousness, paralysis of the external ocular muscles, and ataxia. The disease results from deficiency of vitamin B 1, or thiamine, an essential coenzyme in intermediate carbohydrate metabolism. On the other hand, Jakob-Creutzfeldt disease (J-C) results from infection with an unconventional agent with a long incubation period and is characterized by a rapidly progressive dementia and histologically by a spongiform encephalopathy associated with neuronal destruction and pronounced astrogliosis. Combination of both diseases has not been reported in the literature previously and their relationship is uncertain. We present 3 cases with this interesting association and consider their relationship.

Aged↗

PubMed1988

Adult onset scapuloperoneal myopathy: diagnostic value of nerve morphometry and multiple muscle biopsies.

In the scapuloperoneal syndrome, differentiation between neurogenic and myopathic processes may be difficult despite electromyography and muscle biopsy. Extensive analysis, including morphometry, was conducted on multiple nerve and muscle biopsies from two adult onset, sporadic cases with the syndrome. These studies confirm a myopathic process and further define the entity of adult onset scapuloperoneal myopathy.

Biopsy↗

PubMed1988

Creutzfeldt-Jakob disease without periodic sharp wave complexes: a clinical, electroencephalographic, and pathologic study.

A comparison of clinical, EEG, and pathologic features was carried out on all cases of autopsy-proven Creutzfeldt-Jakob disease (CJD) studied over the last 10 years. Periodic sharp wave complexes (PSWCs) were present in three but absent in seven patients. Myoclonus was documented in two of the three with and in only one of the seven without PSWCs. The three with PSWCs had severe neocortical and at least mild thalamic involvement; those without PSWCs had more variable disease topography. The diagnosis of CJD should not be rejected if PSWCs are absent.

Aged↗

PubMed1987

Complement depletion suppresses Lewis rat experimental allergic neuritis.

Lewis rats immunized with myelin and complete Freund's adjuvant were treated with cobra venom factor (CVF) which depletes the C3 component of complement. CVF given at day 9 delayed the onset of experimental allergic neuritis (EAN) by 2-3 days and when given at days 9 and 12 delayed the onset of EAN by 4-5 days. Lumbar nerve roots of CVF-treated rats had significantly less demyelination than those from control EAN rats.

Animals↗

PubMed1987

NMR changes in experimental allergic encephalomyelitis: NMR changes precede clinical and pathological events.

In guinea pigs immunized with myelin basic protein (MBP) in complete Freund's adjuvant, experimental allergic encephalomyelitis (EAE) shows a characteristic clinical and pathological course. This study characterized the proton nuclear magnetic resonance (NMR) properties of the central nervous system prior to the onset of clinical signs of EAE. At this time (Days 7-9), the blood brain barrier is disrupted. The effects of the injection of paramagnetic contrast agents gadolinium-DTPA and gadolinium-deferoxamine on the tissue NMR relaxation times were examined. Both proton T1 and T2 relaxation times were prolonged in the spinal cord and the brain prior to the onset of clinical and pathological changes. The largest change was in the thoracolumbar spinal cord where T2 prolongation was 22.9%. Gadolinium-DTPA produced a moderate (5-11%) or marked (9-19%) decrease in control and MBP-treated animals, respectively. Gadolinium-deferoxamine also decreased proton relaxation times but was toxic to all animals, producing respiratory arrest. Changes in proton T2 relaxation times in cord and cerebellum were sufficiently large (greater than 10%) to suggest that they might be visualized by magnetic resonance imaging techniques. We have previously described the changes in proton relaxation times during the acute phase of EAE (S.J. Karlik, G. Strejan, J.J. Gilbert, and J.H. Noseworthy, Neurology 36, 1112 (1986]. This study indicates that proton relaxation times are significantly altered at a time when blood brain barrier disruption occurs prior to the onset of clinical or pathological signs.

Animals↗

PubMed1987

Treatment of experimental allergic neuritis with prednisolone.

Experimental allergic neuritis (EAN) in Lewis rats was treated with prednisolone given prophylactically or therapeutically. Rats treated from the time of immunization with myelin or after the establishment of clinical disease improved more rapidly than controls. Treatment at the onset of clinical signs resulted in less severe disease and more rapid recovery. Rats treated just prior to the onset of clinical signs (day 10) did not develop significant clinical disease and appeared to have less inflammation in their nerves and nerve roots on microscopic examination.

Animals↗