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Biomedical subjects

W A Sheremata

Publications and source records attributed to W A Sheremata.

At least 19 recordsLinked to original sources
PubMed2004

Randomized multicenter trial of natalizumab in acute MS relapses: clinical and MRI effects.

BACKGROUND: Relapses in multiple sclerosis (MS) can cause significant neurologic disability. Natalizumab (Antegren) is a humanized anti-alpha4-integrin antibody that inhibits the trafficking of leukocytes across endothelium by blocking binding of alpha4beta1-integrin to vascular cell adhesion molecule-1. OBJECTIVE: To assess the effects of a single dose of IV natalizumab administered soon after the onset of MS relapses. METHODS: In this randomized, double-blind, multicenter trial, the effects of a single dose of IV natalizumab administered soon after the onset of MS relapses were assessed. MS patients (n = 180) in acute relapse were randomly assigned to receive a single dose of natalizumab 1 or 3 mg/kg or placebo and were followed for 14 weeks. RESULTS: There was no difference in Expanded Disability Status Scale (EDSS) score change over time between treatment and placebo groups. In all three groups, approximately half of patients showed EDSS improvement after 2 weeks, rising to 67% by 8 weeks. EDSS improved by a mean value of 0.8 point at week 1, 1.2 points at week 4, and 1.6 points at week 8 in the natalizumab group compared with EDSS improvement of 1.0 point at week 1, 1.6 points at week 4, and 1.6 points at week 8 in the placebo group. A significant decrease in Gd-enhancing lesion volume was seen in both active treatment groups at weeks 1 and 3 compared with placebo. CONCLUSIONS: A single dose of IV natalizumab did not hasten clinical recovery after relapse, although a significant decrease in Gd-enhancing lesion volume was observed at 1 and 3 weeks after treatment. These MRI findings are consistent with prior studies of natalizumab and support its further investigation as an agent for the treatment of MS.

Acute Disease↗
PubMed2001

Perverted head-shaking nystagmus: a possible mechanism.

The authors describe a patient with acute MS who developed vertigo (tumbling) and downbeat nystagmus upon horizontal head oscillation (perverted head-shaking nystagmus). The only abnormality on brain MRI was a hyperintense signal in the caudal medulla that contains the nucleus Roller and nucleus intercalatus. These nuclei project to structures involved in the velocity storage system for horizontal vestibulocular reflex (VOR) and vertical VOR, and also to the vestibular cerebellum. The authors offer possible mechanisms for perverted nystagmus in this patient.

Adult↗
PubMed2001

Elevated plasma endothelial microparticles in multiple sclerosis.

OBJECTIVE: To assess endothelial dysfunction in patients with MS and to investigate whether plasma from patients with MS induces endothelial cell dysfunction in vitro. BACKGROUND: Endothelial cell dysfunction may contribute to the pathogenesis of MS. Elevations of soluble adhesion molecules intracellular adhesion molecule, vascular cell adhesion molecule, and platelet-endothelial cell adhesion molecule-1 (CD31) have been reported as markers of blood-brain barrier (BBB) damage in MS, but direct assay of endothelium has been difficult. Endothelial cells release microparticles < approximately 1.5 microm (EMP) during activation or apoptosis. The authors developed a flow cytometric assay of EMP and studied EMP as markers of endothelial damage in MS. METHODS: Platelet-poor plasma (PPP) from 50 patients with MS (30 in exacerbation and 20 in remission) and 48 controls were labeled with fluorescein isothiocyanate (FITC)-conjugated anti-CD31 and anti-CD51 (vitronectin receptor) antibodies, and two classes of EMP (CD31+ and CD51+) were assayed by flow cytometry. For in vitro studies, patients' plasma was added to the microvascular endothelial cell (MVEC) culture and release of CD31+ and CD51+ EMP were measured in the supernatant. RESULTS: Plasma from patients in exacerbation had 2.85-fold elevation of CD31+ EMP as compared with healthy controls, returning to near control value during remission. The CD31+ EMP concentration showed a positive association with gadolinium enhancement in patients with MS. In contrast, CD51+ EMP remained elevated in both exacerbation and remission. This suggests that CD31+ EMP is a marker of acute injury, whereas CD51+ EMP reflects chronic injury of endothelium. MS plasma induced release of both CD31+ and CD51+ EMP from MVEC culture in vitro. CONCLUSION: Endothelial dysfunction is evident during exacerbation of MS, evidenced by shedding of EMP expressing PECAM-1 (CD31). The in vitro data indicate contribution of one or more plasma factors in endothelial dysfunction of MS.

Adult↗
PubMed2000

Glossopharyngeal neuralgia and MS.

Glossopharyngeal neuralgia (GPN) is characterized by a severe lancing pain in the posterior pharynx, tonsillar fossa, and base of the tongue. It is induced frequently by swallowing and yawning. GPN has not been described previously in MS patients. The authors report four MS patients with GPN. Three responded to carbamazepine and one resolved during treatment with adrenocorticotrophin hormone (ACTH) and cyclophosphamide. Withdrawal of carbamazepine after 1 week in one patient resulted in recurrence of pain. GPN may be associated with MS and responds to carbamazepine.

Adult↗
PubMed1999

A safety and pharmacokinetic study of intravenous natalizumab in patients with MS.

A phase 1, randomized, placebo-controlled, five-level dose escalation safety and tolerability and pharmacokinetic study of a single IV dose of natalizumab was performed. Doses of 0.03 to 3.0 mg/kg natalizumab or placebo were studied in 28 stable relapsing-remitting or secondary-progressive MS. All doses were safe and well tolerated in MS. Serum concentrations of natalizumab are detectable for 3 to 8 weeks after a single 1- or 3-mg/kg IV dose and justify controlled efficacy studies.

Adult↗
PubMed1999

HTLV-II risk factors in Native Americans in Florida.

Earlier virologic studies established that human T-cell lymphotropic virus type II (HTLV-II) is the predominant retrovirus type found among Seminole Indians in southern Florida. We studied 46 members of the Seminole tribe living on 3 reservations to determine the risk factors for HTLV-II and to investigate disease association with the virus. The donors' plasma samples were evaluated with the enzyme-linked immunosorbent and Western blot assays. DNA extracted from their peripheral blood mononuclear cells were analyzed by type-specific polymerase chain reaction amplification and detection of the HTLV pol gene using the primer pair SK110/SK111, and the probes SK112 or SK188. One of 46 (2%) subjects was identified as HTLV-I positive and 11 (24%) were identified as HTLV-II positive. Restriction fragment length polymorphism and sequence analyses indicated that all of the HTLV-II strains were subtype b. Mitochondrial DNA analyses indicated that all of the HTLV-II-positive subjects had an Amerindian haplotype. HTLV-II was more prevalent in Indians who were >45 years of age or female, had multiple sex partners or had received a blood transfusion. However, only the latter risk factor was statistically significant. Three of the HTLV-II-positive Indians demonstrated signs and symptoms of an ataxic neuropathy. The data support that HTLV-IIb is endemic among the Seminoles and that they will be a key population for further virologic studies.

Adult↗
PubMed1997

Relationship of the antispasticity effect of tizanidine to plasma concentration in patients with multiple sclerosis.

BACKGROUND: Spasticity is a serious problem in multiple sclerosis (MS) and many patients do not achieve a satisfactory response to currently available oral antispasticity drugs. Tizanidine hydrochloride, an alpha 2-noradrenergic agonist, has been shown to have an antispasticity effect in single center trials of patients with MS. OBJECTIVE: To compare plasma concentrations of tizanidine with objective measures of muscle tone in patients with MS with moderate to severe spasticity. SETTING: Ten centers, all tertiary referral centers for the specialized treatment of patients with MS, in the United States and Canada. DESIGN: A randomized, double-blind, placebo-controlled, dose-response study of tizanidine hydrochloride (8 or 16 mg). PATIENTS: One hundred forty-two patients with spastic MS who were not taking any interfering medication, such as an antispasticity drug or other alpha-noradrenergic agonist, entered the trial. RESULTS: Tizanidine treatment reduced muscle tone significantly, as shown by improved Ashworth scores and increased knee swing amplitude recorded by the pendulum test, both of which correlated significantly with plasma concentration. Placebo had no significant effect on muscle tone. Dizziness, drowsiness, dry mouth, and fatigue were reported most often in the group treated with tizanidine at peak plasma concentration. CONCLUSIONS: Tizanidine reduces spasticity in MS, and both therapeutic effects and side effects are related to the plasma drug levels.

Adrenergic alpha-Agonists↗
PubMed1993

Association of '(tropical) ataxic neuropathy' with HTLV-II.

Jamaican Neuropathy of the ataxic type (tropical ataxic neuropathy [TAN] and spastic type (tropical spastic paraparesis [TSP]) have been recognized for over a century in Jamaica. The recent association of TSP with HTLV-I (TSP/HAM) is now well established. We now present evidence for a possible association between a TAN-like illness with HTLV-II in four females aged 34-49. All presented with ataxic gait and all four have prominent mental changes. Three of the four also have minor motor deficits with urinary frequency and two have nocturnal leg cramps. All have serum antibody and all had PCR evidence of HTLV-II infection. Antibody to HTLV-II is present in CSF from two subjects. The distinctive picture of prominent ataxia and altered mental status in these subjects contrasts with a predominantly myelopathic picture seen in TSP/HAM.

Adult↗
PubMed1993

High-dose zidovudine induction in HTLV-I-associated myelopathy: safety and possible efficacy.

Ten HTLV-I-associated myelopathy (HAM) patients (four men and six women aged 38 to 58 years) with Expanded Disability Status Scale (EDSS) scores ranging from 4.0 to 8.5 entered an open-label zidovudine study. A high-dosage induction (2 g/d for 4 weeks) was followed by 1 g/d for 20 weeks. Five patients were natives of the Caribbean island Hispaniola, and one each was from Colombia, Cuba, El Salvador, Jamaica, and the United States; all were positive by polymerase chain reaction, and nine had positive Western immunoblots for HTLV-I. Side effects included anxiety, insomnia, gastric upset, anorexia, and loss of taste. Preexisting leg cramps were increased in two and headaches in one. Hemoglobin decreased from a mean of 13.5 to 11.8 g/dl and the hematocrit from 40.7% to 34.9% at 8 weeks, and then stabilized. Neutropenia appeared regularly but did not necessitate drug withdrawal. Mean EDSS scores changed little for the group as a whole, but the seven ambulatory patients improved objectively, with their scores dropping from 5.5 to 4.0 and none worsening. Timed gait improved by at least 50%. Following withdrawal, four of the five who had improved regressed. Zidovudine appears to be safe in subjects with HAM who have no other major health problems and should be investigated further.

Adult↗
PubMed1992

Event-related potential P300 in multiple sclerosis. Relation to magnetic resonance imaging and cognitive impairment.

Cerebral involvement in multiple sclerosis may result not only in sensory and motor symptoms but also in impaired mentation. We hypothesize that cognitive dysfunction occurs due to cortical deafferentation or disconnection arising from subcortical white-matter disease. We examined the P300 event-related potential in 31 patients with multiple sclerosis, correlating it with disease severity ratings based on magnetic resonance imaging signal intensity changes, cognitive dysfunction, and disability status. The patients with multiple sclerosis exhibited significantly prolonged P300 wave latencies compared with 32 control subjects. The P300 latency was strongly correlated with the presence of demyelinative brain lesions seen on magnetic resonance imaging scans and with cognitive impairment, but was only weakly associated with the Kurtzke disability status score, consistent with this scale primarily reflecting spinal rather than cerebral demyelination. Our study results support a relationship between subcortical white-matter lesions and cognitive impairment in multiple sclerosis.

Adult↗
PubMed1992

Human T lymphotropic virus type I-associated myelopathy. A report of 10 patients born in the United States.

Human T lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM) (tropical spastic paraparesis/HAM) has rarely been reported in the United States. We present 10 well-documented cases with positive Western immunoblot test results and polymerase chain reactions for HTLV-I. The clinical and laboratory features of these American-born patients resemble those previously reported series of tropical spastic paraparesis and HAM from the Caribbean and Japan, but important differences were observed. In our study there were equal numbers of whites and blacks and of men and women. Age at onset was younger than that reported from the Caribbean and Japan. Rate of progression to paraparesis varied but was more rapid than previously reported. Half were transfusion recipients but six had multiple sexual partners, with one regularly interacting with prostitutes and reporting a history of drug abuse. Although more rapid progression was seen in the transfusion recipients, this did not explain the earlier age of onset in this group of patients. The HTLV-I, and the associated myelopathy, are endemic in Florida, suggesting that immigration from, and proximity, to the Caribbean basin are contributing risk factors.

Adult↗
PubMed1991

Hemifacial spasm. Occurrence in multiple sclerosis.

We present six patients with hemifacial spasm and multiple sclerosis. To our knowledge, this association has not been described previously in the North American literature. Magnetic resonance imaging was obtained in all the patients and plaques consistent with multiple sclerosis were identified. In two patients the plaques were seen in the area of the facial nucleus on the involved side. We suggest that hemifacial spasm can be a manifestation of multiple sclerosis. These cases illustrate the utility of magnetic resonance imaging in the investigation of hemifacial spasm. Our findings also support a central (nuclear) origin in multiple sclerosis associated with hemifacial spasm.

Adrenocorticotropic Hormone↗
PubMed1991

Tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM): treatment with an anabolic steroid danazol.

Tropical spastic paraparesis or HTLV-I-associated myelopathy is a progressive spastic disorder associated with the human T-lymphotropic virus type I. Some cases have responded to prednisone. Danazol is an attenuated androgen with minimal virilizing effects. It is used in the treatment of endometriosis and various autoimmune hematologic diseases shown to be responsive to prednisone. Because danazol is anabolic, useful in prednisone-responsive diseases, and less toxic than prednisone, we gave danazol to 6 patients with TSP and 1 with HIV, HTLV-I-associated myelopathy. Five patients had a favorable response. Two became ambulatory after having been confined to a wheelchair. Three were able to ambulate greater distances (in walkers) than prior to danazol. Three had noticeable decreases in spasticity. Urinary incontinence resolved in two. Physical therapy was variably employed in all except one patient. Two patients who had not responded to physical therapy responded to physical therapy and danazol. One patient did not tolerate danazol and one patient did not improve. Toxicities noted were mild elevations in liver enzymes in 4 patients; these responded to a decrease in dose of danazol; amenorrhea in one and mild fluid retention in one. We conclude that danazol is a useful agent in the management of TSP.

Adult↗
PubMed1989

Magnetic resonance imaging of spinal cord lesions in multiple sclerosis.

The clinical and pathological manifestations of multiple sclerosis are due to areas of demyelination which occur throughout the white matter of the central nervous system. MRI of the brain frequently shows abnormalities in the hemispheric subcortical white matter; these are demonstrable in the majority of patients and support the clinical diagnosis of multiple sclerosis. Our studies have shown that while MRI identifies such cerebral lesions in nearly all clinically definite multiple sclerosis patients with illness of duration greater than 10 years, these areas of abnormal T2 signal are present less often in the brains of patients studied within 3 years of disease onset. However, symptoms referable to the long tracts of the spinal cord are prominent in many of these patients. Imaging of the spinal cord has presented technical problems because of the small size of the cord, patient body, heart and respiratory movements, and limitations of surface coil technology. The spinal cord of 77 patients with multiple sclerosis have been imaged, revealing three types of abnormalities: (1) approximately half the cords show regions of abnormal T2 weighted signal; (2) during acute exacerbation, spinal cord enlargement (swelling) may be observed; (3) spinal cord atrophy (narrowing) is found particularly in patients with disease of longer duration and greater disability. Unlike the presence of brain lesions, the existence of spinal cord lesions of high T2 signal is not associated with increasing duration of disease but is correlated with disability status. Of patients with such lesions about one fifth did not exhibit brain lesions discernible by MRI.

Adult↗
PubMed1989

Multiple sclerosis-like illness occurring with human immunodeficiency virus infection.

We describe seven men with a neurologic disease clinically indistinguishable from multiple sclerosis occurring in association with seropositivity for the human immunodeficiency virus, type 1 (HIV-1). Histopathology of the CNS obtained in three patients (2 by brain biopsy, 1 at autopsy) was consistent with MS. The neurologic symptoms preceded the onset of clinically evident immunosuppression in all patients. In three men, HIV-1 seropositivity was demonstrated concomitantly or within 3 months of the onset of their neurologic disease. In the others, features of MS preceded the demonstration of HIV-1 seropositivity by 41 months, 59 months, 11 years, and 18 years, respectively. Despite the superimposition of varying degrees of cellular immunodeficiency associated with HIV-1 infection, six of these men continued to experience relapsing neurologic symptoms.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Immunological findings in neurological diseases associated with antibodies to HTLV-I: activated lymphocytes in tropical spastic paraparesis.

A retrovirus involvement in the etiology of certain neurological diseases is currently an area of intense interest. Tropical spastic paraparesis and other chronic progressive myelopathies have been clearly associated with increased serum and cerebrospinal fluid antibody titers to human T-lymphotropic virus type I; however, little is known about the cellular immune response. In the present study, activated T-lymphocytes were found in the peripheral blood of patients with this disorder. There were increased numbers of large CD3-positive cells that also expressed histocompatibility leukocyte Class II (DR) and interleukin 2-receptor molecules. In addition, a significantly elevated spontaneous lymphoproliferative response was demonstrated in all patients. This is consistent with the known in vitro effects of human T-lymphotropic virus type I. In one patient, a defect in the generation of measles virus-specific cytotoxic T cells was identified. These observations indicate abnormalities of the cellular immune response in tropical spastic paraparesis.

Antibodies, Viral↗
PubMed1988

Multiple sclerosis: correlation of magnetic resonance imaging with cerebrospinal fluid findings.

MRI examination of 41 patients with clinical definite multiple sclerosis showed white matter lesions of high proton T2 signal consistent with demyelination in 76% and CSF abnormalities present in 76%. Of patients with CSF abnormalities, 26% had normal MRI scans; conversely 26% of patients with MRI abnormalities had negative CSF studies. Thus a significant number of multiple sclerosis patients had negative results on either MRI or CSF examination, while only 5% had normal results on both tests.

Adult↗