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Biomedical subjects

K Bell

Publications and source records attributed to K Bell.

At least 109 records · Page 6Linked to original sources
PubMed1995

Neurologic signs and symptoms in a cohort of homosexual men followed for 4.5 years.

We traced the development of neurologic impairment in 207 homosexual men (123 human immunodeficiency virus [HIV]-positive and 84 HIV-negative controls) over 4.5 years of follow-up. We applied generalized estimating equations to logistic regression analyses with repeated measures to examine the differences between HIV-positive and HIV-negative subjects with respect to the likelihood of developing six neurologic outcomes derived from a factor analysis, significant neurologic impairment (modified Kurtzke disability score of > or = 3), or significant neuropsychological impairment. We found that, over time, HIV-positive subjects were more likely to develop clinically significant extrapyramidal signs and frontal release signs than HIV-negative subjects. Controlling for age or education, as CD4 count declined, the odds of developing significant extrapyramidal signs, abnormalities in alternating movements, frontal release signs, and a Kurtzke score > or = 3 increased. HIV-positive subjects were almost five times as likely (odds ratio [OR], 4.6; 95% CI, 1.6 to 13.4) as HIV-negative subjects to stay the same or worsen neurologically on the next visit, and those with CD4 < or = 200 were 4.8 times as likely (OR, 4.8; 95% CI, 2.2 to 10.7) to maintain or worsen neurologically relative to those with higher CD4 counts. We conclude that neurologic impairment becomes increasingly apparent over time in HIV-infected men, especially in those with low CD4 counts.

Adult↗
PubMed1994

A coordinated, communitywide program in Monroe County, New York, to increase influenza immunization rates in the elderly.

BACKGROUND: Despite the efficacy of influenza vaccination in preventing complications of influenza, rates of immunization among high-risk populations remain low. The Monroe County (New York) Influenza Vaccination Demonstration was a communitywide, collaborative effort to increase the rates of influenza immunization to greater than 60% in elderly Medicare recipients. METHODS: The local health department, university medical center, and practicing physicians collaborated to develop a communitywide demonstration directed to all Medicare part B enrollees 65 years of age or older, multiple coordinated approaches were used over a 4-year period (1988 to 1992). Most providers, including public agencies, private providers, hospital outpatient facilities, nursing homes, and insurance providers, were enrolled in a comprehensive program that included centralized claims processing, vaccine distribution and promotion, and extensive provider and public education efforts, including a special urban outreach program. An office-based, denominator-driven physician incentive project was also evaluated. RESULTS: The demonstration project resulted in a 1991 influenza immunization rate of 74.3% among 88,811 Medicare enrollees 65 years of age or older. The increase in immunization rate occurred primarily among the patients of private physicians. CONCLUSION: A communitywide, collaborative approach can succeed in achieving high rates of influenza immunization.

Aged↗
PubMed1994

Blood protein polymorphisms in the donkey (Equus asinus).

Transferrin, albumin, 6-phosphogluconate dehydrogenase and vitamin D-binding protein polymorphisms were detected in 242 feral and domesticated Australian donkeys by polyacrylamide gel electrophoresis, starch gel electrophoresis, autoradiography, immunoblotting with specific antisera and activity staining. All four TF and two ALB variants were donkey specific while only one of the PGD variants was donkey specific. The two GC variants were electrophoretically identical to the Equus caballus F and S proteins. Available evidence suggested that the TF, ALB, PGD and GC systems are controlled by co-dominant alleles with frequencies of the most common alleles of each system being 0.831, 0.946, 0.957 and 0.861 respectively. Glucose phosphate isomerase and plasminogen were monomorphic in the Australian population of donkeys.

Animals↗
PubMed1994

Intrageneric amplification of horse microsatellite markers with emphasis on the Przewalski's horse (E. przewalskii).

Primer sequences flanking 13 microsatellite loci isolated from the domestic horse (E. caballus) were successfully used to amplify homologous loci in the Przewalski's horse (E. przewalskii). The results demonstrate that the level of polymorphism at all 13 loci in the Przewalski's horse was comparable to that in the domestic horse and the overall exclusion probability in the Przewalski's horse was calculated to be 0.9994. The results suggest that it should be possible to use E. caballus-derived microsatellite markers to provide parentage verification and additional valuable information to the captive management of E. przewalskii. The ability to amplify corresponding loci in the remaining five species of the genus was also confirmed, illustrating the general application of markers isolated from the domestic horse to the evaluation of polymorphism in the other six species of the genus.

Animals↗
PubMed1994

Utility of extrapyramidal signs and psychosis as predictors of cognitive and functional decline, nursing home admission, and death in Alzheimer's disease: prospective analyses from the Predictors Study.

OBJECTIVE: To examine whether either extrapyramidal signs or psychotic features are associated with more rapid progression of Alzheimer's disease. BACKGROUND: It has been unclear whether extrapyramidal signs and psychosis are predictors of faster course or are simply late signs. METHODS: Two hundred thirty-six patients with mild Alzheimer's disease were recruited in three cities and followed semiannually. RESULTS: Using Cox proportional hazards models that adjusted for age, sex, disease severity, and estimated duration of illness at study entry, the presence of extrapyramidal signs at entry was associated with higher relative risk (RR) of reaching moderate cognitive (RR = 2.35, 95% CI = 1.12 to 4.92) or functional (RR = 2.31, 95% CI = 1.37 to 3.90) severity, nursing home entry (RR = 2.51, 95% CI = 1.32 to 4.76), or death (RR = 3.04, 95% CI = 1.31 to 7.05). Psychosis predicted only the functional end point (RR = 1.85, 95% CI = 1.18 to 2.90). Using regression models, modified Mini-Mental State scores declined 1.30 points (95% CI = 0.16 to 2.44) per 6-month interval, more among patients with than those without extrapyramidal signs; patients with psychosis declined 1.15 (95% CI = 0.52 to 1.77) more mMMS points per interval. CONCLUSIONS: This study confirms extrapyramidal signs and psychosis as robust predictors of disease end points and rapid progression in Alzheimer's disease.

Age Factors↗
PubMed1994

Age at onset of Alzheimer's disease: relation to pattern of cognitive dysfunction and rate of decline.

We examined the pattern of cognitive impairment and rate of cognitive and functional decline as a function of age at symptom onset in 127 patients with probable Alzheimer's disease (AD). At baseline, early-onset (before age 65) and late-onset groups were mildly and comparably impaired on the modified Mini-Mental State Examination (mMMS) and the Blessed Dementia Rating Scale-Part 1 (BDRS). Repeated-measures analysis of variance revealed significantly more rapid decline in early-onset subjects over a 2-year follow-up period. Multivariate linear regression analyses indicated that age at symptom onset strongly predicted rate of decline on the mMMS and the BDRS, even after controlling for symptom duration, gender, family history of dementia, and baseline mMMS and BDRS scores. Early- and late-onset AD subjects also differed in terms of pattern of performance on the mMMS. Early-onset subjects scored significantly lower than late-onset subjects on attentional items of the mMMS at baseline and follow-up. Conversely, late-onset subjects scored significantly lower than early-onset subjects on memory and naming items at baseline, and the two groups were comparable on these tasks at follow-up. Results provide longitudinal evidence of more rapid cognitive and functional decline in subjects with early-onset AD and suggest that early-onset AD may be characterized by predominant impairment of attentional skills.

Age of Onset↗
PubMed1993

Preoperative coagulopathy in ruptured abdominal aortic aneurysm predicts poor outcome.

In a prospective study of 50 consecutive patients undergoing operation for ruptured abdominal aortic aneurysm, a coagulation screen was performed on admission to hospital. Twenty patients with either a platelet count < 100 x 10(9)/l or a prothrombin time > 1.5 times the control value had a mortality rate of 65 per cent (95 per cent confidence interval 45-85 per cent); a further 23 patients with normal screen results had a mortality rate of 9 per cent (95 per cent confidence interval 0-20 per cent) (P < 0.001). Seven patients, of whom three died, did not have an admission coagulation screen performed. Patient age in the study group did not have independent statistical predictive power. This study indicates that coagulopathy at the time of admission predicts poor outcome in patients with ruptured aortic aneurysm. Current management strategies are inadequate for the treatment of these patients, who can be rapidly identified on admission by means of platelet and prothrombin counts.

Aortic Aneurysm, Abdominal↗
PubMed1993

Caprine blood groups. 1. The B system.

Twelve of 24 monospecific caprine reagents produced by absorption of alloimmune antisera identified a complex blood group system of goats which was designated B, based on the results of a small comparison test with ovine reagents. The frequencies of the 12 B factors differed significantly among the Australian Angora, Texan Angora, Cashmere, and Dairy goat breeds. Three of the antigens detected by the reagents were shown to be related as linear subtypes, designated Ba1, Ba2, and Ba3, and inherited as alleles. The segregations of B factors in 80 sire groups involving 1086 offspring demonstrated that groups of B factors (phenogroups) segregated as products of allelic genes.

Animals↗
PubMed1993

Caprine blood groups. 2. The C, G, H, I, J, K, L, N, and Q systems.

Nine blood group systems of goats were identified using 12 caprine reagents produced by absorption of alloimmune antisera. The caprine C blood group system, possibly homologous to the ovine C blood group system, was characterized by two reagents and shown to be controlled by three alleles, C12, C25, and C-. A more complex blood group system of goats, designated G, was identified using three reagents and shown to be controlled by six codominant alleles (G10.19.20, G10.19, G10.20, G10, G19, G20) and a recessive allele (G-). A further seven one-factor two-allelic systems were identified by seven reagents. The nine genetic systems provided exclusion probabilities of 0.479, 0.492, 0.548, and 0.572 in Australian Angora, Dairy, Cashmere, and Texan Angora goat breeds, respectively.

Alleles↗
PubMed1993

Feline and canine milk lysozymes.

1. The electrophoretic characteristics of feline (Felis catus) and canine (Canis familiaris) milk lysozymes were studied using starch gel electrophoresis and isoelectric focusing. 2. Feline milk lysozyme was found to be polymorphic (two variants, designated A and B with frequencies of 0.13 and 0.87, respectively). Canine milk lysozyme was not polymorphic. 3. The lytic activities of feline and canine milk lysozymes were examined in buffers of varying pH and ionic strength. Preliminary kinetics studies were done. 4. Maximal lytic activity for both lysozymes was found in imidazole-HCl buffer pH 7.4 and both exhibited second order reaction kinetics. 5. Amino acid compositions of both lysozymes were determined.

Amino Acids↗
PubMed1993

Caprine plasma proteinase inhibitors--I. Partial characterization.

1. Using two-dimensional electrophoresis (IEF, pH 3.5-6.0 and PAGE, 11.5% T, pH 7.9) the caprine plasma proteinase inhibitors were classified into six distinct classes, designated PIA, PIB, PIC, PID, PIE and PIF. Differentiation of the six inhibitors was based on electrophoretic criteria, their abilities to inhibit bovine trypsin and chymotrypsin and their crossreactions with antisera to human alpha 1-antitrypsin and alpha 1-antichymotrypsin. 2. Polymorphic variants were identified for five of the protein systems (PIA, PIB, PIC, PID and PIE) and the electrophoretic data indicated that the variants were controlled by allelic genes. PIF proteins were poorly resolved and invariant. 3. Treatment of selected plasmas with neuraminidase demonstrated that the microheterogeneity observed in the PIA, PIB, PIC and PID proteins was attributable to sialic acid additions. 4. The inhibitory activities of all six caprine proteinase inhibitors were unaffected by chemical oxidation with chloramine-T.

Animals↗
PubMed1993

Caprine plasma proteinase inhibitors--II. Genetic analysis.

1. Analysis of the inheritances of the variants of five caprine plasma proteinase inhibitor systems in families demonstrated a genetic control of codominant alleles at five loci. 2. The PIA, B, C, D and E proteins are controlled by four (PIA1,2,3,4), three (PIB1,4,0), three (PIC2,3,0), five (PID1,2,3,4,0) and two (PIE1,2) alleles respectively. Null alleles were postulated for the PIB, PIC and PID systems. 3. The frequencies of the alleles differed substantially between the Australian and Texan Angoras and Cashmere breeds of goats. 4. The combined exclusion probability for the five PI systems was as high as 0.82 in the Cashmere breed, indicating the potential of the proteinase inhibitor proteins for parentage control purposes.

Alleles↗
PubMed1993

Multicenter study of predictors of disease course in Alzheimer disease (the "predictors study"). I. Study design, cohort description, and intersite comparisons.

Clinicians should be able to provide the patient with Alzheimer disease (AD) and the family with an accurate prediction of what to expect, but the variability in the rate of disease progression precludes this. In several previous studies, specific clinical signs such as muscular rigidity, myoclonus, and hallucinations or delusions were associated with rapid progression to a more severe stage of dementia or death. The "Predictors Study," a longitudinal study at three independent sites, was designed to develop a predictor model of the natural history of Alzheimer disease. The study was conducted at three study sites, New York, Baltimore, and Boston in a cohort of 224 patients with early probable AD. This article describes the design and implementation of the Predictors Study, and compares features of the study cohort at baseline across sites. Patients were all at the mild stage of disease at entry and were relatively comparable across sites. Extrapyramidal signs and delusions were common, but myoclonus was rarely observed.

Activities of Daily Living↗
PubMed1993

Multicenter study of predictors of disease course in Alzheimer disease (the "predictors study"). II. Neurological, psychiatric, and demographic influences on baseline measures of disease severity.

The "Predictors Study" is a prospective cohort study of the natural history of Alzheimer disease (AD), the aim of which is to identify milestones in disease progression and to develop a model to predict disease course in individual patients. The empirical background to this study is based on previous reports that the presence of extrapyramidal signs (EPS), myoclonus, and psychosis in AD may signify greater disease severity at any given stage and a more rapid course of the disease over time. The present analyses were conducted to determine whether these independent "predictor" variables were associated with greater disease severity at baseline within a new cohort of 224 mild AD patients recruited from three different medical centers (in New York, Baltimore, and Boston). Measures of disease severity were provided by the modified Mini-Mental State Examination (mMMSE) and the Blessed Dementia Rating Scale (BDRS), which measures functional capacity. Independent variables were EPS, delusions, and slowing of the posterior dominant EEG rhythm. The frequency of myoclonus and hallucinations was too low to permit adequate statistical assessment of their effects at this time. EPS and EEG slowing were associated with low mMMSE scores, whereas delusions were primarily associated with impaired functional capacity. These effects were independent of the influence of age and disease duration. These results indicate that the effects of these independent variables can be detected at mild stages of AD and that these effects can be generalized across different geographical regions.

Aged↗