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Biomedical subjects

E Silber

Publications and source records attributed to E Silber.

At least 19 recordsLinked to original sources
PubMed2003

Clinical features of headache at altitude: a prospective study.

BACKGROUND: Headache is the most common nervous system complication at altitude; however, there have been few attempts to characterize clinical features of high-altitude headaches (HAH). OBJECTIVE: To measure prospectively the incidence of HAH and to determine its risk factors and characteristics. METHODS: Members of an expedition to Kanchenjunga base camp in Nepal (5,100 m) were prospectively studied. Subjects were interviewed prior to the trip and while trekking recorded headaches experienced at >3,000 m using a structured questionnaire incorporating International Headache Society (IHS) and acute mountain sickness (AMS) criteria. In addition, clinical features of headaches in 19 trekkers in other groups above 3,000 m were recorded using the same questionnaire. RESULTS: Eighty-three percent (50/60) reported at least 1 HAH (median 2, range 0 to 10). Those who developed HAH were younger (p = 0.04); women and persons with headaches in daily life were more likely to report severe headaches (p = 0.03 and p = 0.07). One hundred thirty-eight HAH, experienced by 69 persons, are described. The mean altitude at which headaches occurred was 4,723 m. Twenty-six percent of headaches woke subjects at night or occurred upon awakening. HAH reported by migraineurs were accompanied by more phonophobia (p = 0.008). There were no IHS accompanying symptoms in 44% of headaches or symptoms of AMS in 52% of headaches. CONCLUSIONS: Headaches are a frequent complication of ascent to altitude. Older age appears to offer some protection, whereas headaches were more severe in women and persons with headaches in daily life. There is a wide clinical spectrum, with some suggesting intracranial hypertension. There is a need for evidence-based diagnostic criteria for headaches at altitude.

Adaptation, Physiological↗
PubMed2003

Multiple sclerosis: Neurofilament light chain antibodies are correlated to cerebral atrophy.

OBJECTIVE: To evaluate markers of axonal damage in CSF and serum of patients with different subtypes of MS in relation to measures of disease progression on MRI. METHODS: In 51 patients with MS (21 relapsing-remitting, 20 secondary progressive, 10 primary progressive), levels of heavy and light neurofilaments (NfH and NfL) and antibodies to neurofilaments (anti-NfL and -NfH) as well as the total immunoglobulin G (IgG) were analyzed. MRI analysis included T2 hyperintense, T1 hypointense, and gadolinium enhancing lesions and markers of cerebral atrophy (ventricular and parenchymal fractions). RESULTS: For the total group, correlations were found between the anti-NfL index and the parenchymal fraction (PF) (r = -0.51, p < 0.001), T2 lesion load (r = 0.41, p < 0.05), ventricular fraction (r = 0.37, p < 0.05), and T1 lesion load (r = 0.37, p < 0.05). For the anti-NfH index, a correlation was found with the PF (r = -0.39, p < 0.05). No correlations were found between the IgG index and MRI measures. CONCLUSIONS: Intrathecal production of anti-NfL antibodies may serve as a marker of tissue damage, particularly axonal loss, in MS.

Adult↗
PubMed2002

Patients with progressive multiple sclerosis have elevated antibodies to neurofilament subunit.

OBJECTIVE: The cause of axonal loss, an important contributor to disability in MS, is poorly understood. This study investigated whether progression in MS is associated with CSF antibodies to the 68-kd light neurofilament subunit (NF-L), an axonal cytoskeletal protein, and compared this with antibodies against tubulin and the heavy neurofilament subunit (NF-H). METHODS: IgG to NF-L, tubulin, and NF-H was measured by immunoassay in matched CSF and serum samples from patients with relapsing-remitting MS (RRMS; n = 39), primary progressive MS (PPMS; n = 10), and secondary progressive MS (SPMS; n = 18); patients with other inflammatory (n = 21) and noninflammatory (n = 40) neurologic diseases; and healthy controls (n = 12). Immunocytochemistry was performed to assess antibody binding to human brain sections, and isoelectric focusing with immunoblotting was performed to assess oligoclonal anti-NF-L production. RESULTS: Intrathecal production of anti-NF-L antibodies was significantly elevated in PPMS and SPMS. In contrast, there were no significant differences in CSF levels of antibodies to tubulin or NF-H between the groups. Anti-NF-L, antitubulin, and anti-NF-H levels correlated with the duration of disease before lumbar puncture and Expanded Disability Status Scale levels. Immunocytochemistry demonstrated binding of CSF or serum antibodies to axonal or neuronal components in six of seven RRMS patients, seven of seven PPMS patients, and eight of 10 SPMS patients tested. Isoelectric focusing demonstrated independent CSF oligoclonal bands reactive with NF-L in six of 13 specimens tested. CONCLUSIONS: Anti-NF-L antibodies seem to be raised in progressive MS and may serve as a marker for axonal loss and disease progression. They may contribute to axonal loss and the accumulation of disability.

Adult↗
PubMed2000

Upper limb motor function at 5000 metres: determinants of performance and residual sequelae.

Little is known about the effects of age and symptoms of acute mountain sickness and the potential benefit of short term acclimatisation on fine motor performance at altitude. There is uncertainty about whether time spent at altitude results in permanent neurological sequelae. Nine hole pegboard tests were performed on a group of trekkers at sea level (n=61), after ascending to Kanchenjunga base camp (5100 m; n=46), and 20 weeks after return to sea level (n=43). Comparison of baseline and altitude times showed a mean slowing from 36.2 to 39.0 seconds, a 7. 8% deterioration in performance (p<0.0001), which was greatest in subjects aged 50 years or older (5.04 v 1.93 seconds, p=0.017), those tested within 24 hours of arrival at 5100 m (4.75 seconds, 13. 3% v 0.48 seconds, 1.3% p<0.001), and persons experiencing symptoms of acute mountain sickness (p=0.012), each of which were independent determinants of deterioration. Repeat pegboard testing at sea level after 20 weeks showed no significant change compared with baseline (p=0.68). This confirms the deleterious effects of altitude on fine motor function, emphasises the benefit of acclimatisation, and suggests that older persons and those with symptoms of acute mountain sickness are particularly susceptible. The risk of long term motor dysfunction after exposure to these relatively moderate altitudes seems to be small.

Adaptation, Physiological↗
PubMed2000

Meningococcal disease in South African goldmines--epidemiology and strategies for control.

OBJECTIVES: To describe the epidemiology of meningococcal disease in South African goldmines and to suggest strategies for the prevention and control of further outbreaks. DESIGN: We prospectively investigated a meningococcal outbreak that occurred in 1996 and describe the control measures that were implemented. In addition, we conducted a retrospective analysis of routinely collected data on meningococcal disease in these mines from 1972 to 1996. SETTING: Four goldmines in Gauteng, employing 30,000 workers who live in hostels. SUBJECTS: All cases of meningococcal disease at the mine hospital. RESULTS: Between 1972 and 1976, 588 cases were diagnosed, with peaks in 1972 (203 cases, 727/100,000) and 1975 (147 cases, 564/100,000). Since 1978 less than 5 cases have been reported in most years, but smaller outbreaks occurred in 1990 (30 cases, 89/100,000) and 1996 (14 cases, 50/100,000). The 1996 outbreak (group A, clone I-1) was part of a larger outbreak in Gauteng that originated in Mozambique and began in one mine in July 1996, after which a mass vaccination campaign was implemented. This was followed by a smaller outbreak among non-vaccinated workers at an adjacent mine. Five patients were new recruits. CONCLUSIONS: Despite a dramatic reduction in meningococcal disease over the last 25 years due mainly to changes in the work force, there are still outbreaks in this community. Those most at risk are young men who are new to the industry. Suggestions for prevention include effective surveillance, routine vaccination of new recruits and a rapid response to outbreaks, with mass vaccination and provision of chemoprophylaxis to close contacts.

Adolescent↗
PubMed1999

Axonal degeneration in the pathogenesis of multiple sclerosis.

Axonal degeneration plays an important role in the accumulation of disability in patients with multiple sclerosis (MS). Pathological studies have demonstrated axonal damage, particularly in areas of acute inflammation and demyelination, and in chronic lesions. Axonal loss and its progression, which is associated with neurological disability, has also been demonstrated by magnetic resonance imaging (MRI) studies. The mechanisms of axonal loss are uncertain, but may involve axonal degeneration secondary to demyelination, or damage to the axonal cytoskeleton. Inflammatory mediators, including cytokines and proteolytic enzymes may contribute to axonal damage, as may nitric oxide. Axonal destruction may also be due to immune attack directed at axonal components. The realisation that axonal degeneration is a fundamental component of MS that may occur early in the disease course should alter the approach to management and open avenues to a more targeted immunotherapy aimed at reducing the progression of disability.

Axons↗
PubMed1999

Meningitis in a community with a high prevalence of tuberculosis and HIV infection.

OBJECTIVES: To evaluate the spectrum of aetiologies, and distinguishing clinical and laboratory features, of meningeal infection in a community with a high prevalence of tuberculosis (TB) and HIV infection. SETTING: A hospital serving mineworkers, originating from rural areas of Southern Africa. DESIGN: Prospective cohort of 60 consecutive lumbar punctures (LPs), performed for suspected meningitis. MEASUREMENTS: Clinical history and examination; concurrent cerebrospinal fluid (CSF) and blood samples; mortality status six months after entry to study. RESULTS: 38 of 57 patients (66.7%) were HIV-1 positive, 59.5% of whom had a CD4 count <200 cells/mm3. Nine patients had tuberculous meningitis (TBM) and two had tuberculomas; four developed disease while on TB therapy. There was one case of multidrug, and two of isoniazid-resistant TBM. There were nine episodes of cryptococcal meningitis (seven patients), nine of aseptic meningitis, two of neurosyphilis and 20 normal LPs, including four with AIDS dementia complex (ADC). Ten patients with meningococcal infection, part of a larger outbreak, were significantly younger (p=0.004). All patients with tuberculous, cryptococcal (most immune-suppressed p<0.001) and aseptic meningitis were HIV-1 positive. Within six months, 19 patients had died. Death was associated with HIV positivity (p=0.004), low CD4 count (p<0.001) and a diagnosis of cryptococcal meningitis, CNS TB or ADC. CONCLUSION: HIV has a major impact on the burden of disease and mortality, with a predominance of opportunistic chronic meningitides, despite a meningococcal outbreak, in this community. Of concern is the development of TBM despite therapy, and the emergence of drug-resistant strains.

AIDS Dementia Complex↗
PubMed1998

Huntington's disease confirmed by genetic testing in five African families.

Huntington's disease is an autosomal-dominant inherited progressive neurodegenerative disease associated with an expanded trinucleotide repeat (CAG) sequence on the short arm of chromosome 4. The disease is considered rare in Africans. We report five black South African families of different ethnic origin with proven expansions typical of Huntington's disease and discuss the possible origins of the disease in Africa.

Black People↗
PubMed1998

High human immunodeficiency virus type 1 RNA load in the cerebrospinal fluid from patients with lymphocytic meningitis.

Thirty-seven matched cerebrospinal fluid (CSF) and plasma samples from 34 human immunodeficiency virus type 1 (HIV-1)-infected patients with suspected meningitis were analyzed for levels of HIV-1 RNA and markers of inflammation. Patients with tuberculous (n = 9) or cryptococcal (n = 6) meningitis had the highest CSF virus loads, which in many cases exceeded the levels in plasma, compared with patients with meningococcal meningitis (n = 3), aseptic meningitis (n = 8), tuberculoma (n = 2), or AIDS dementia complex (n = 4) or with normal lumbar punctures (n = 3). CSF virus load correlated significantly with the number of infiltrating lymphocytes (r = .60, P < .001) but not with plasma virus load, the levels of beta2-microglobulin in the CSF, or the integrity of the blood-brain barrier. These data suggest significant intrathecal HIV-1 replication in patients with lymphocytic meningeal infections such as tuberculous and cryptococcal meningitis.

AIDS Dementia Complex↗
PubMed1998

Dual infective pathology in patients with cryptococcal meningitis.

Coinfection of the nervous system by two distinct nonviral organisms is uncommon and often undiagnosed. Medical teaching emphasizes that a single pathologic process should be sought; however, in the presence of severe immunocompromise this approach may not hold true. We describe seven HIV-1 seropositive patients with cryptococcal meningitis, three of whom had a proven nervous system infection with a second organism: concurrent tuberculous meningitis, a tuberculoma, and the first documented case of cryptococcal meningitis and neurosyphilis.

AIDS-Related Opportunistic Infections↗
PubMed1997

[Psychodynamic treatment in Alzheimer's disease].

The psychodynamic approach to a patient's experience of having Alzheimer's disease requires more research. It is a therapeutic objective to allow a patient with Alzheimer disease to obtain a realistic perception of his own condition, particularly since this is frequently unusual for this group of patients.

Adaptation, Psychological↗
PubMed1996

Intermittent inotropic therapy in an outpatient setting: a cost-effective therapeutic modality in patients with refractory heart failure.

Patients with intractable heart failure (New York Heart Association [NYHA] class III and IV) who were receiving maximal conventional treatment were enrolled in an outpatient program that included inotropic infusions, intensive patient education, and close follow-up. The effects of this approach to therapy were evaluated on (1) the number of hospital admissions, (2) length of stay, and (3) number of emergency room visits during the ensuing year. These data were compared with similar data from the year before entry in the program for each patient. Thirty-six patients with stable NYHA class III and IV heart failure received milrinone or dobutamine to manage chronic heart failure in an outpatient setting. The cause of heart failure was ischemic heart disease in 12, idiopathic in 11, hypertension in 8, and pulmonary hypertension in 5. Four patients received dobutamine and 32 patients received milrinone. The mean period of observation was 294 days. For the period before entry in the program, patients had 21 emergency room visits, 75 admissions, and 528 days spent in the hospital. After enrollment, patients had 10 emergency room visits, 34 admissions, and 150 days spent in the hospital. In conclusion, this therapeutic regimen reduced the number of hospital admissions, days spent in the hospital, and emergency room visits. Our study supports the concept that the use of intermittent inotropic therapy in the outpatient setting plays an important role in managing this severely ill group of patients.

Ambulatory Care↗