Biomedical subjects
Publications and source records attributed to D Myers.
Chronic lymphocytic leukemia (CLL) is incurable with conventional therapy. Recent data report favorable results with allogeneic transplant. We report a patient with CLL with persistent leukemia post-transplant who obtained remission after discontinuing immune suppression.
This study had three goals: (1) Identify patients with Helicobacter pylori, treat their disease, monitor their progress, and determine that they are no longer infected. (2) Realize a cost savings for our health clinic. (3) Improve patient quality of life. These three goals have been met.
OBJECTIVE: To test the verbal memory of older volunteers given citicoline. DESIGN: A randomized, double-blind, placebo-controlled, parallel group design was employed in the initial study. After data analysis, a subgroup was identified whose members had relatively inefficient memories. These subjects were recruited for a second study that used a crossover design. The subjects took either placebo or citicoline, 1000 mg/d, for 3 months in the initial study. In the crossover study, subjects took both placebo and citicoline, 2000 mg/d, each for 2 months. SUBJECTS: The subjects were 47 female and 48 male volunteers 50 to 85 years old. They were screened for dementia, memory disorders, and other neurological problems. Of the subjects with relatively inefficient memories, 32 participated in the crossover study. MAIN OUTCOME MEASURE: Verbal memory was tested at each study visit using a logical memory passage. Plasma choline concentrations were measured at baseline; at days 30, 60, and 90 in the initial study; and at day 60 of each treatment condition in the crossover study. Plasma choline concentrations and memory scores were analyzed using repeated-measures analysis of variance and covariance, followed by planned comparisons when appropriate. RESULTS: In the initial study, citicoline therapy improved delayed recall on logical memory only for the subjects with relatively inefficient memories. In the crossover study, the higher dosage of citicoline was clearly associated with improved immediate and delayed logical memory. CONCLUSIONS: Citicoline therapy improved verbal memory functioning in older individuals with relatively inefficient memories. Citicoline may prove effective in treating age-related cognitive decline that may be the precursor of dementia.
The density of beta-amyloid (A beta) deposits was studied in the medial temporal lobe in non-demented individuals and in sporadic Alzheimer's disease (SAD) and Down's syndrome (DS). No A beta deposits were recorded in six of the non-demented cases, while in a further eight cases, these were confined to either the lateral occipitotemporal or parahippocampal gyrus. The mean density of A beta deposits in the cortex was greater in SAD and DS than in non-demented cases but with overlap between patient groups. The mean density of A beta deposits was greater in DS than SAD consistent with a gene dosage effect. The ratio of primitive to diffuse A beta deposits was greater in DS and in non-demented cases than in SAD and the ratio of classic to diffuse deposits was lowest in DS. In all groups, A beta deposits occurred in clusters which were often regularly distributed. In the cortex, the dimension of the A beta clusters was greater in SAD than in the non-demented cases and DS. The data suggest that the development of A beta pathology in the hippocampus could be a factor in the development of DS and SAD. Furthermore, the high density of A beta deposits, and in particular the high proportion of primitive type deposits, may be important in DS while the development of large clusters of A beta deposits may be a factor in SAD.
Managed care has changed the way health care is delivered in the United States. Simultaneously, major changes in the management of patients with coronary heart disease has led to dramatic shifts in cardiac rehabilitation. Exercise training, education, and counseling to modify coronary risk factors has clearly been shown to benefit patients with coronary disease. Moreover, intensive risk factor modification has been shown to prevent progression of coronary atherosclerosis and to lower morbidity and mortality. Newer delivery models of rehabilitation are needed to improve health outcomes in a cost-effective way. A nursing case management model (MULTIFIT), illustrates one such innovative delivery model that meets the needs of a managed care plan for comprehensive cardiovascular risk reduction and surveillance of patients.
Nedocromil sodium and cromolyn sodium are the only two currently available nonsteroid anti-inflammatory agents for treatment of asthma. Clinical differences between the two agents remain under continuous investigation with reports differentiating the two on the basis of atopy of the patient and reversibility of bronchoconstriction. This study investigated the efficacy of nedocromil sodium (4 mg, qid) for treatment of mild-to-moderate asthma in comparison to placebo using cromolyn sodium (2 mg, qid) as an active control treatment. Patients were primarily allergic asthmatics (with at least 15% reversibility) previously maintained on a regimen of regular bronchodilator therapy. During a 2-week run-in period, the patient's slow-release theophylline therapy was removed, and the patients were randomized to treatment after deterioration of asthma control (asthma symptom summary score of 3 for 7 of the 14 days). After 8 weeks of treatment, patients were returned to as occasion requires bronchodilator therapy, as per the 2-week baseline period. The results demonstrate that patients treated with nedocromil sodium showed statistically significant improvements during the primary time period (mean weeks 3 through 8) over placebo-treated patients as evidenced by all indexes of asthma symptoms, pulmonary function measures, and decreased bronchodilator reliance (p<0.05). Patients treated with cromolyn sodium demonstrated similar improvements over placebo-treated patients. Comparisons between nedocromil sodium and cromolyn sodium showed the two agents to be comparable in this group of primarily allergic patients with reversible disease. Between-group differences were noted for 3 of the 13 variables (nighttime asthma, FEV1, and forced expiratory flow rate between 25 % and 75% of the FVC) in favor of cromolyn sodium when the data were pooled during the primary time period. The number of patients missing 1 or more days from work/school/regular activity due to asthma was significantly fewer compared with placebo, and favoring nedocromil sodium over cromolyn sodium. No differences were observed among the three treatments for adverse events. This study demonstrated that in primarily allergic patients with reversible airways disease, nedocromil sodium and cromolyn sodium are both significantly more effective than placebo for treatment of mild-to-moderate asthma.
To what degree do immigrants reduce their high rates of residential overcrowding with increasing length of residence in the United States? This question is addressed through the application of a "double cohort" method that nests birth cohorts within immigration cohorts. This method enables duration of immigration effects to be separated from aging effects as cohorts pass through life course phases, when family sizes may be growing or shrinking. The analysis finds that cohort trends differ sharply from the cross-sectional pattern observed at a single point in time. Cohorts' growth in income is found to contribute substantially to the decline in overcrowding over time. Cohort trends among Hispanic immigrants, however, diverge from those among others, indicating much less decrease in overcrowding and even increases over certain age spans.
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Trypanosoma brucei ornithine decarboxylase was reconstituted by coexpression of two polypeptides corresponding to residues 1-305 and residues 306-425 in Escherichia coli. The two peptides were coexpressed, at wild-type levels, from a single transcriptional unit that was separated by a 15-nucleotide untranslated region containing a ribosome binding site. The fragmented enzyme was purified and analyzed. The N- and C-terminal peptides are tightly associated into a fully active tetramer which has the same molecular weight as the native dimer. The kinetic constants (Km and kcat) measured for the decarboxylation of ornithine are identical to those obtained for the wild-type enzyme. These results suggest that the enzyme is organized into two structural domains, with a domain boundary in the region of amino acid 305. In contrast, the individual N- and C-terminal peptides are expressed primarily as inclusion bodies. Small quantities of soluble N-terminal peptide could be purified. This truncated protein is capable of inhibiting the wild-type enzyme, suggesting that it is folded into a native-like structure. Limited proteolysis with trypsin or chymotrypsin identifies a likely surface loop at amino acids 160-170, present in both the mouse and T. brucei enzyme, which positions one or more functionally important active site residues (e.g., Lys169). Kinetic analysis of a chimeric enzyme composed of T. brucei and mouse ornithine decarboxylase suggests that the substrate carboxylate binding determinant is located between residues 1 and 170.
The factors determining the size of individual beta-amyloid (A beta) deposits and their size frequency distribution in tissue from Alzheimer's disease (AD) patients have not been established. In 23/25 cortical tissues from 10 AD patients, the frequency of A beta deposits declined exponentially with increasing size. In a random sample of 400 A beta deposits, 88% were closely associated with one or more neuronal cell bodies. The frequency distribution of A beta deposits which were associated with 0,1,2,...,n neuronal cell bodies deviated significantly from a Poisson distribution, suggesting a degree of clustering of the neuronal cell bodies. In addition, the frequency of A beta deposits declined exponentially as the number of associated neuronal cell bodies increased. A beta deposit area was positively correlated with the frequency of associated neuronal cell bodies, the degree of correlation being greater for pyramidal cells than smaller neurons. These data suggested: (1) the number of closely adjacent neuronal cell bodies which simultaneously secrete A beta was an important factor determining the size of an A beta deposit and (2) the exponential decline in larger A beta deposits reflects the low probability that larger numbers of adjacent neurons will secrete A beta simultaneously to form a deposit.
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Extracts of the cotyledons of germinated honey locust (Gleditsia triacanthos) seeds, which contain galactomannan as a reserve polysaccharide in the endosperm, were fractionated by chromatography and the fractions examined for the presence of a specific manno-6-kinase which could phosphorylate the D-mannose released by hydrolysis of galactomannan. One particulate hexokinase (the major hexose-6-kinase fraction) and two soluble hexokinase fractions (the minor portion), as well as a soluble fructo-6-kinase fraction, were initially separated. From chromatography, electrophoresis and kinetic studies, no evidence for a specific manno-kinase was obtained. This and the level and kinetic behaviour of the particulate hexokinase implicated it as the enzyme catalysing the phosphorylation of released D-mannose. The fructo-kinase activity was further separated into three fractions. Kinetic studies on one of these with native and synthetic substrates indicated that the structural requirements for the monosaccharide substrate were a beta-D-anomeric 2-OH in the furanose ring, a 4-OH trans to the D-5-CH2OH and a -CH2OH substituent on C2 (trans to the 5-CH2OH) which could be modified. The orientation of the hydroxyl on C-3 had only a limited effect.
PURPOSE/OBJECTIVES: To describe the characteristics of a child's bone marrow transplant (BMT) experience that may precipitate a post-traumatic stress disorder (PTSD) in the parent. DATA SOURCES: Published articles, books, and the authors' clinical experience. DATA SYNTHESIS: When viewed from the PTSD framework, parental reactions to a child's BMT offer striking parallels that include assessment of the event as traumatic, re-experiencing the event, intrusive thoughts, and a variety of emotional and cognitive responses. Interventions based on PTSD research can be implemented in clinical settings to diminish and treat these responses. CONCLUSIONS: The PTSD framework holds promise for healthcare providers in devising strategies to help families of children undergoing BMT to cope with the experience. IMPLICATIONS FOR NURSING PRACTICE: Nurses can use orientation, education, coaching, and peer support to help families before BMT and debriefing and counseling after BMT.
The spatial patterns of diffuse, primitive, classic (cored) and compact (burnt-out) subtypes of beta/A4 deposits were studied in coronal sections of the frontal lobe and hippocampus, including the adjacent gyri, in nine cases of Alzheimer's disease (AD). If the more mature deposits were derived from the diffuse deposits then there should be a close association between their spatial patterns in a brain region. In the majority of tissues examined, all deposit subtypes occurred in clusters which varied in dimension from 200 to 6400 microns. In many tissues, the clusters appeared to be regularly spaced parallel to the pia or alveus. The mean dimension of the primitive deposit clusters was greater than those of the diffuse, classic and compact types. In about 60% of cortical tissues examined, the clusters of primitive and diffuse deposits were not in phase, i.e. they alternated along the cortical strip. Clusters of classic deposits appeared to be distributed independently of the diffuse deposit clusters. Cluster size of the primitive deposits was positively correlated with the density of the primitive deposits in a tissue but no such relationship could be detected for the diffuse deposits. This study suggested that there was a complex relationship between the clusters of the different subtypes of beta/A4 deposits. If the diffuse deposits do give rise to the primitive and classic varieties then factors unrelated to the initial deposition of beta/A4 in the form of diffuse plaques were important in the formation of the mature deposits.
Hyperbaric oxygen has been shown to improve oxygen tension and promote wound healing. We did a pilot study in which we created ischemic jejunal segments measuring 3, 6, and 9 cm, 10 of each length, in 30 rats. Half of the rats were given hyperbaric oxygen at 100%, 30 psi, for 90 minutes twice daily for 7 days to determine whether hyperbaric oxygen therapy could overcome the ischemic intestinal injury and prevent ischemic necrosis. In the rats with 6- and 9-cm ischemic segments, no difference was seen between the hyperbaric oxygen and control groups. Of the rats with 3-cm ischemic segments, ischemic infarction of the bowel developed in 40% of the hyperbaric oxygen group and 100% of the controls (P = 0.167, Fisher's Exact Test). We then created 3-cm ischemic intestinal segments in 30 additional rats. Again, half were treated with hyperbaric oxygen as previously described for 7 days. There was no difference between the controls and the hyperbaric oxygen group in the rate of perforation (4 of 15 [27%] versus 1 of 15 [7%]) or stricture rate (8 of 15 [53%] versus 9 of 15 [60%]). We concluded that hyperbaric oxygen therapy is of limited value for the treatment of intestinal ischemias.
1. The turnover rate of inositol(1,4,5)trisphosphate (Ins(1,4,5)P3) in noradrenaline-stimulated adult rat left atria was calculated from changes in specific activity and was found to equal 110 ct/min per mg tissue. In contrast, the isomers of inositol mono- and bisphosphates accumulated at a rate of 508 ct/min per mg. 2. Neomycin, which inhibits release of Ins(1,4,5)P3, inhibited the accumulation of inositol phosphates in noradrenaline-stimulated isolated neonatal cardiomyocytes but did not inhibit accumulation in left atria. 3. These data demonstrate that most of the inositol phosphates which accumulate in adult rat left atria do not derive from Ins(1,4,5)P3. 4. These data are best explained by a model in which noradrenaline stimulation results mainly in the breakdown of phosphatidylinositol(4)monophosphate (PtIns(4)P1) to inositol(1,4)bisphosphate (Ins(1,4)P2). Thus, heart tissue avoids the generation of Ins(1,4,5)P3.
The application of artificial neural networks to real-time image processing tasks requires the use of dedicated, high performance hardware. A linear array processor called HANNIBAL has been developed which implements the backpropagation neural learning algorithm on-chip. This paper considers the design of a complete neural system which integrates HANNIBAL into an existing image processing environment. The goals for the design of the system have been set partly by the primary application, namely feature recognition, but mainly by the desire for a flexible, high performance hardware tool for the study and evaluation of range of neural image processing applications.
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