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Biomedical subjects

K Bell

Publications and source records attributed to K Bell.

At least 127 records · Page 7Linked to original sources
PubMed1993

Safety and efficacy of oral physostigmine in the treatment of Alzheimer disease.

Results of therapeutic trials with physostigmine in the treatment of Alzheimer disease (AD) have been inconsistent and controversy persists concerning safety and efficacy. In a double-blind, placebo-controlled, crossover study, patients received 6 weeks of oral physostigmine (OP) and placebo in random order. Twenty-nine patients with AD received as much as 16 mg/day of OP and were assessed with neuropsychological and functional measures. No significant cardiac side effects were noted, though other systemic adverse effects were noted, requiring dose reduction in four patients. There was a slight but significant improvement (12%) in performance on the selective reminding test with physostigmine and the memory performance was correlated with dosage. This improvement compares favorably with the 15% decrease in scores seen in an untreated comparison cohort followed for an equivalent time period. There was a trend toward an improvement in communication and a reduction in memory complaint. These results suggest that oral physostigmine is safe and may improve memory in AD.

Administration, Oral↗
PubMed1993

Patterns of neuropsychological performance in Alzheimer's disease patients with and without extrapyramidal signs.

We investigated the relationship between extrapyramidal signs (EPS) and the cognitive function in 90 patients meeting NINCDS-ADRDA criteria for probable Alzheimer's disease (AD) by dividing them into those showing no evidence of EPS and those showing at least one EPS on the Unified Parkinson's Disease Rating Scale. Cognitive function was assessed by neuropsychological tests of verbal memory, orientation, abstract reasoning, language, and construction. Patients with EPS were significantly more impaired than patients without EPS on tests of short-term learning and memory, orientation, naming, verbal fluency, and construction, but not on tests of long-term memory, abstract reasoning, or verbal comprehension. These results could not be explained by any differences in age, education, or disease duration between the groups. Since this pattern of neuropsychological impairment resembles that of patients with Parkinson's disease and other EPS syndromes, we hypothesize that EPS are associated with neuropathologic and neuropsychological changes that are superimposed over the classic features of AD.

Aged↗
PubMed1992

An estimate of the incidence of depression in idiopathic Parkinson's disease.

Estimates of the prevalence of depression in idiopathic Parkinson's disease vary, but have been greater than in most comparison groups. In a survey of patients with Parkinson's disease (N = 339), the prevalence of depression was 47%. A total of 326 cases were reviewed to estimate the incidence of depression from September 30, 1984, to July 31, 1989. Assessments of depression during both the prevalent and the incident periods were noted in 258 cases. There was no history of depression in 129 cases, and nine new cases occurred. The incidence rate was 1.86% per year and the cumulative risk was 8.6%. Published estimates of the incidence of depression in the general population are few. In one study, the annual incidence of depression in individuals older than 40 years was 0.17%. In another, the incidence of depression in individuals older than 50 years was 0.14% for men and 0.29% for women. Although our retrospective study probably underdiagnoses depression, the incidence of depression is increased in Parkinson's disease.

Aged↗
PubMed1992

The Columbia University Scale for Psychopathology in Alzheimer's disease.

The Columbia University Scale for Psychopathology in Alzheimer's disease is a new screening instrument developed for use by clinicians or trained lay interviewers. Interrater reliability was established between a psychiatrist and a lay interviewer in 20 patients. In an independent sample of 91 outpatients with very mild to moderate probable Alzheimer's disease, caregiver informants reported that depressed mood was common (46.2%) but rarely persistent (2.2%), and that sleep disturbance occurred frequently (41.8%) but was never severe (0%). There were significant but weak associations between the presence of specific subtypes of delusions and severity of dementia. Although a variety of delusional symptoms were reported, they were frequently transient and patients often accepted the truth if corrected by the caregiver. As a result, few patients met broad or narrow operational criteria used to define delusions. Prior studies may have overestimated the prevalence of psychotic features in Alzheimer's disease by not employing standard definitional criteria. The findings also indicate that new methodology such as that employed in this instrument needs to be evaluated more widely.

Aged↗
PubMed1992

Double-blind parallel design pilot study of acetyl levocarnitine in patients with Alzheimer's disease.

Acetyl levocarnitine hydrochloride has been reported to retard dementia in patients with Alzheimer's disease. In a double-blind, parallel design, placebo-controlled pilot study of 30 mild to moderately demented patients with probable Alzheimer's disease, tests of memory, attention, language, visuospatial, and constructional abilities were administered, and the level of acetyl levocarnitine was measured in the cerebrospinal fluid. Patients were then randomly assigned to receive acetyl levocarnitine hydrochloride (2.5 g/d for 3 months followed by 3 g/d for 3 months) or placebo. After 6 months, the acetyl levocarnitine group demonstrated significantly less deterioration in timed cancellation tasks and Digit Span (forward) and a trend toward less deterioration in a timed verbal fluency task. No differences were found in any other neuropsychological test results. A subgroup with the lowest baseline scores, receiving acetyl levocarnitine, had significantly less deterioration on the verbal memory test and a significant increase in cerebrospinal fluid acetyl levocarnitine levels compared with those receiving placebo. These results suggest that acetyl levocarnitine may retard the deterioration in some cognitive areas in patients with Alzheimer's disease and stress the need for a larger study of this drug.

Acetylcarnitine↗
PubMed1992

Neurologic and neuropsychological manifestations of human immunodeficiency virus infection in intravenous drug users without acquired immunodeficiency syndrome. Relationship to head injury.

We examined 99 human immunodeficiency virus (HIV)-negative and 122 HIV-positive intravenous drug users (IVDUs) without acquired immunodeficiency syndrome (AIDS) to determine whether HIV-positive IVDUs had more neurologic and neuropsychological impairment than their HIV-negative counterparts. Controlling for age, education, drug use, history of head injury, and interactions between head injury and HIV status and drug use, HIV-positive subjects had more extrapyramidal signs and frontal release signs. These findings persisted when asymptomatic HIV-positive subjects without systemic signs of infection and HIV-negative subjects were compared. Neurologic findings were more severe in those with more systemic illness. Among those reporting a history of head injury with loss of consciousness, neuropsychological performance was significantly worse in the HIV-positive subjects, and this increased with severity of illness. This was not true in the group without head injury, suggesting an interaction between history of head injury and the seropositive state. No relationship was noted between head injury and either drug use or HIV state. Therefore, subtle neurologic and neuropsychological abnormalities may precede clinical evidence of AIDS in IVDUs and may be more evident in those with head injury.

Adult↗
PubMed1992

Canine plasma alkaline phosphatase polymorphism and its relationship with the canine Tr blood group system.

A canine blood group antigen, QN, which was detected by a naturally occurring alloantibody in the antiglobulin test, was shown to be antigenically related to the human A and cattle J antigens by absorption experiments. Family studies supported a dominant mode of inheritance with the gene controlling the production of QN being dominant to the gene responsible for its absence. Frequencies of the QN and Tr antigens and serological data strongly suggested that the two antigens are identical. Two canine plasma alkaline phosphatase variants, F and S, were detected by starch gel electrophoresis, pH 8.65. Assuming genetic control of two codominant alleles, ALPF and ALPS, the distributions of types in families differed significantly from expectation. A relationship between the ALP and Tr(QN) systems was demonstrated with Tr-positive animals having a significant deficiency of S alkaline phosphatase types.

Alkaline Phosphatase↗
PubMed1992

Canine blood groups: description of 20 specificities.

Twenty blood typing reagents, four agglutinins and 16 operable in the antiglobulin test, were prepared from 54 antisera which were produced in 24 dogs. Two of the reagents were identified as anti-B and Nf6. Two of the antigens were shown by absorption and family studies to be linear subtypes. In most cases, detailed family studies demonstrated a Mendelian dominant inheritance for the genes controlling the canine red cell antigens. Gene frequencies were determined in various breeds of dogs and in the dingo.

Agglutinins↗
PubMed1992

A new transferrin allele in Australian goats.

Subdivision of TF B into two variants, B1 (faster) and B2 (slower) in Australian goat breeds was accomplished by high voltage, thin layer polyacrylamide gel electrophoresis at pH 7.9. The genes controlling the caprine transferrins were shown to be autosomal codominant alleles, TFA, TFB1, TFB2 and TFC and in the various breeds of goats, the alleles were in Hardy-Weinberg equilibrium. TFA was the most common allele in the Australian and Texan Angora, Cashmere and Dairy breeds with gene frequencies ranging from 0.652 to 0.977. TFB1 and TFB2 occurred in all four breeds while TFC was only observed in very low frequencies in Australian Angora and Cashmere breeds.

Alleles↗
PubMed1992

Genetic polymorphism of plasma vitamin D-binding protein (GC) in Australian goats.

Polymorphism at the GC locus in goats was detected using isoelectric focusing (pH 4.5-5.4) and immunoblotting with antiserum to human GC. Three variants, designated A, B and C in order of decreasing mobility to the anode, were detected and were shown to be controlled by three codominant alleles, GCA, GCB and GCC. GCA and GCB occurred in all four breeds (Australian and Texan Angora, Cashmere and Dairy) with GCA being the most common and having gene frequencies ranging from 0.851 to 0.993. GCC was found only in Australian Angora and Cashmere animals. The products of the three GC alleles had isoelectric points in the range pH 4.63-4.95 and M(r) of approximately 54,375. The major isoforms of the three alleles were shown to contain sialic acid. Linkage between the GC and albumin loci was unable to be demonstrated due to the low frequency of ALBA (0.02) in the Cashmere breed.

Animals↗
PubMed1992

A controlled trial of intra-operative autologous transfusion in cardiothoracic surgery measuring effect on transfusion requirements and clinical outcome.

We carried out a prospective, controlled trial of intra-operative autologous transfusion (IOAT) in cardiac surgery using the Haemonetics Cellsaver 4, to determine the effects on transfusion requirements and early clinical outcome. Intra-operative autologous transfusion in unselected patients resulted in a reduction in the use of red cells in patients undergoing first-time operations (IOAT median 3 units, controls median 4 units, P = 0.0023), with no difference in the use of other blood products. Post-operative haemoglobin was higher in IOAT patients (IOAT 11.6 g/dl +/- 1.1 versus controls 11.2 g/dl +/- 0.98, P < 0.001). There is therefore the potential for a further reduction in homologous blood use in the IOAT group. There was no difference in early clinical outcome in the two groups; in particular the incidence of coagulopathies was not influenced by IOAT. The routine use of IOAT would add substantially to the cost of these operations. The decision to use it must therefore be based on an assessment of the value of the reduction in risk to the patient achieved by a small reduction in homologous donor exposures.

Adult↗
PubMed1992

Antithrombin III (AT3) polymorphism in the marsupial Monodelphis domestica: identification and genetics.

Antithrombin III polymorphism was observed in the gray short-tailed opossum, Monodelphis domestica, by either one-dimensional polyacrylamide gel electrophoresis (PAGE; pH 7.9), two-dimensional PAGE (agarose, pH 5.4; 12% T, pH 7.9), or isoelectric focusing (pH 4.2-4.9) followed by immunoblotting with rabbit antiserum to human antithrombin III. Family studies demonstrated an inheritance of three codominant autosomal alleles, AT3A, AT3B, and AT3C, and a population study revealed frequencies of 0.70, 0.10, and 0.20, respectively.

Alleles↗
PubMed1991

The complete amino acid sequence of feline beta-lactoglobulin II and a partial revision of the equine beta-lactoglobulin II sequence.

The amino acid sequence of feline beta-lactoglobulin (designated II) has been determined. The protein chain is 163 amino acids long with a relative molecular mass of 18,558. The primary structure was determined by sequencing of native protein (residues 1-25), BPNS-skatole cleavage fragments and the peptides obtained by proteolytic cleavage with V8 proteinase and TPCK-trypsin. Feline beta-lactoglobulin II has 53 and 57% positional identities with bovine beta-lactoglobulin A and equine beta-lactoglobulin I, respectively, and approx. 68% with a revised sequence of equine beta-lactoglobulin II. The equine beta-lactoglobulin II sequence was re-examined between positions 78 and 122 resulting in a major revision in this area with only a single insertion to give a total of 163 residues.

Amino Acid Sequence↗
PubMed1991

Interrater reliability of extrapyramidal signs in a group assessed for dementia.

Extrapyramidal signs were rated by three neurologists in 20 patients who had either been diagnosed as having probable Alzheimer's disease or who were being evaluated for dementia. In general, good interrater reliability was found for the presence or absence of extrapyramidal signs, although agreement over the presence of some signs was reduced when distinctions between normality and slight departures from normality were required.

Aged↗
PubMed1991

Multidisciplinary baseline assessment of homosexual men with and without human immunodeficiency virus infection. III. Neurologic and neuropsychological findings.

We explored the possibility that neurologic and neuropsychological changes constitute the earliest detectable manifestations of human immunodeficiency virus (HIV) infection. Without knowledge of HIV status, we assessed neurologic signs and symptoms and administered a battery of neuropsychological tests to 208 homosexual men, of whom 84 were HIV negative, 49 were HIV positive and asymptomatic, 29 were mildly symptomatic, and 46 had significant medical symptoms but not the acquired immunodeficiency syndrome. There was no difference between the HIV-negative and HIV-positive men in the frequency of neurologic signs or of defective or borderline performance on any neuropsychological test. However, HIV-positive men performed slightly but significantly worse than HIV-negative men on tests of verbal memory, executive function, and language. Similar results were obtained when comparisons were limited to HIV-positive medically asymptomatic and HIV-negative men. There was no degradation of neurologic status or neuropsychological performance across stages of HIV severity, but neurologic and neuropsychological summary scores correlated with CD4/CD8 ratios in the HIV-positive group. Ratings of neurologic signs and symptoms correlated with neuropsychological summary scores in the HIV-positive group only. Cognitive complaints were more frequent in the HIV-positive men; they correlated with actual test performance in the HIV-positive but not HIV-negative men. The constellation of subjective and objective neuropsychological and neurologic findings suggests the possibility of a definable syndrome associated with HIV infection in asymptomatic individuals.

Adolescent↗