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Biomedical subjects

R A Ali

Publications and source records attributed to R A Ali.

10 recordsLinked to original sources
PubMed2006

Multiresolution wavelet analysis for efficient analysis, compression and remote display of long-term physiological signals.

Increased inter-equipment connectivity coupled with advances in Web technology allows ever escalating amounts of physiological data to be produced, far too much to be displayed adequately on a single computer screen. The consequence is that large quantities of insignificant data will be transmitted and reviewed. This carries an increased risk of overlooking vitally important transients. This paper describes a technique to provide an integrated solution based on a single algorithm for the efficient analysis, compression and remote display of long-term physiological signals with infrequent short duration, yet vital events, to effect a reduction in data transmission and display cluttering and to facilitate reliable data interpretation. The algorithm analyses data at the server end and flags significant events. It produces a compressed version of the signal at a lower resolution that can be satisfactorily viewed in a single screen width. This reduced set of data is initially transmitted together with a set of 'flags' indicating where significant events occur. Subsequent transmissions need only involve transmission of flagged data segments of interest at the required resolution. Efficient processing and code protection with decomposition alone is novel. The fixed transmission length method ensures clutter-less display, irrespective of the data length. The flagging of annotated events in arterial oxygen saturation, electroencephalogram and electrocardiogram illustrates the generic property of the algorithm. Data reduction of 87% to 99% and improved displays are demonstrated.

Algorithms↗
PubMed2002

Interactions of poult enteritis and mortality syndrome-associated reovirus with various cell types in vitro.

An avian reovirus, ARV-CU98, has recently been isolated from poults experiencing poult enteritis and mortality syndrome (PEMS). To further understand ARV-CU98 and its role in PEMS, the current study investigates interactions of ARV-CU98 with various cell types in vitro. When macrophages, B cells, T cells, and liver cells of chicken or turkey origin were co-incubated with ARV-CU98, only cells of liver origin demonstrated cytopathic effects, the presence of viral antigen, and reduced metabolic activity over time. Furthermore, distinctive pockets of viral particles were evident in electron microscopic examination of a chicken hepatocellular carcinoma (LMH) cell line, but not in a chicken macrophage cell line (MQ-NCSU) co-incubated with virus. Additional evidence of viral replication in LMH, cells but not MQ-NCSU cells was demonstrated by the presence of two viral bands (43 and 145 kD size) in cell lysates from LMH cells exposed to ARV-CU98. Although not capable of being infected by ARV-CU98, MQ-NCSU cells do appear to be activated by the virus since IL-1 mRNA expression is increased in MQ-NCSU cells 2 h after addition of the virus. LMH cells exposed to the virus demonstrate a decrease in IL-1 mRNA expression by 8 to 10 h after addition of the virus, perhaps corresponding to the initiation of infection by the virus. In conclusion, this study demonstrates that ARV-CU98 actively infects and replicates in LMH cells, but not in lymphocytes or macrophages, suggesting that the liver may be a target and site of replication of ARV-CU98 in poults experiencing PEMS.

Animals↗
PubMed2000

Alloantigen systems L and P influence phagocytic function independent of the major histocompatability complex (B) in chickens.

Synthetic parent stocks were designed to produce progeny among which alleles were simultaneously segregating for nine alloantigen systems, including the MHC (B). Chicks from Ancona-derived B19B19 females crossed with White leghorn B19B21 males were blood typed, resulting in genotypic categories for the A-E, C, D, H, I, L, and P loci with the objective of determining which, if any, of the eight non-MHC alloantigen systems influence or interact with the B system genotypes for blood monocyte phagocytic activity. Leukocytes obtained from whole blood at 2 and 4 wk were separated on a Fico/Lite LymphoH, density gradient and were allowed to adhere to glass coverslips. The resulting adherent monocyte monolayers were incubated with viable Escherichia coli for 1 h and stained with Leukostat, and the phagocytic monocytes and numbers of internalized bacteria per phagocytic monocyte were scored microscopically. The combined results from two separate trials demonstrated that the genotypes of the A-E, C, D, H, and I systems did not differ in the percentage of monocytes exhibiting phagocytosis, whereas significant differences were noted relative to the B system genotype at 2 wk of age (B19B21 > B19B19; P = 0.049), L at 4 wk (L1L1 > L1L2; P = 0.009), and P at 4 wk (P4P4 > P1P1; P = 0.047). The data were further analyzed to determine any interactions of P and L alloantigen genotypes with the B system genotypes; no such interaction was observed. These studies suggest that the L and P non-MHC alloantigen systems have the potential to influence immune responses by modulating phagocytic function in chickens. Furthermore, this modulation seems to be independent of the B (MHC) system.

Animals↗
PubMed2000

A comparison of the pattern of liver involvement in dengue hemorrhagic fever with classic dengue fever.

The impact of dengue on liver function was studied on fifty serologically confirmed dengue cases admitted to Hospital Universiti Kebangsaan Malaysia (HUKM). Twenty-five of these patients had classic dengue fever (DF) and 25 had grade 1 or 2 dengue hemorrhagic fever (DHF). There were more (60%) DHF patients with hepatomegaly compared to DF (40%) but the difference was not statistically significant. Analysis of the liver profile showed that liver dysfunction was commoner in DHF compared to DF, indicating that the degree of liver impairment may be related to the severity of DHF. Hyperbilirubinemia was noted in 3 (12%) DHF and 2 (8%) DF patients. The mean (range) serum bilirubin was higher in DHF [14.2(5-50) micromol/l] compared to DF [10.9(5-30) micromol/l)] (p > 0.05). Elevated levels of serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP) were observed more frequently in DHF (20 and 12 patients respectively) compared to DF (16 and 8 patients respectively). Nine (36%) DHF and 6 (24%) DF patients had concomitant elevation of ALT and ALP levels. The mean (range) serum ALT levels were 109.3(23-325) U/l in DHF and 90.8(13-352) U/l in DF (p > 0.05). The mean (range) serum ALP levels were 102.2(15-319) U/l in DHF and 93.3(34-258) U/l in DF (p > 0.05). The ALT and ALP levels were significantly higher in DHF patients with spontaneous bleeding than those without bleeding (p < 0.05) None of the patients developed fulminant hepatitis. The immunoregulatory cells, which include the T (CD3), B (CD 19), CD4, CD8, CD5 and natural killer (NK) cells were significantly lower in DHF compared to DF patients (p < 0.05). However, the reduction in these cell counts did not correlate with the liver dysfunction seen in DHF patients. In conclusion, hepatomegaly and liver dysfunction were commoner in DHF compared to DF.

Adolescent↗
PubMed1996

Spirulina platensis exposure enhances macrophage phagocytic function in cats.

Bronchoalveolar lavage macrophages isolated from cats were cultured on glass coverslips. Macrophages were exposed to a water-soluble extract of Spirulina platensis in concentration range of 0 to 60 micrograms per mL for two hours. Spirulina-extract exposure did not cause significant macrophage cytotoxicity over untreated control cultures. Macrophage monolayers from treated and control cultures were incubated with sheep red blood cells (SRBC) as well as viable Escherichia coli. The percentages of phagocytic macrophages for both of these particulate antigens were higher (a two-fold increase in SRBC phagocytosis and over 10% increase in Escherichia coli uptake) in cultures treated with various concentrations of Spirulina-extract. However, the numbers of either types of particles internalized by phagocytic macrophage were not different between the control and treated cultures. These data which showed that Spirulina platensis extract enhances macrophage phagocytic function imply that dietary Spirulina supplementation may improve the disease resistance potential in cats.

Adjuvants, Immunologic↗
PubMed1994

Profile of chicken macrophage functions after exposure to catecholamines in vitro.

The effects of catecholamines (CA) on various chicken macrophage functions were examined. Macrophage monolayers were exposed to .01, .1, .25, 1, 2, and 5 micrograms/mL of dopamine (DA), norepinephrine (NE) and epinephrine (E) for 1 hr. All CA were toxic for macrophages at 1-5 micrograms dose range resulting in 25-50% cell death. All CA at the .1 and .25 micrograms/mL level increased E. coli and sheep red blood cells (SRBC) phagocytosis by macrophages. The percentage of Fc-receptor positive macrophages increased after CA exposure. Prolonged exposure of macrophages (3 hr) reduced SRBC phagocytosis by DA-treated but not in NE- and E-treated macrophages. However, after 1 hr exposure and 3 hr recovery period, CA-induced changes were reversed in all but DA-treated cultures. Apomorphine and metoclopromide blocked DA whereas propranolol blocked NE and E effects suggesting specificity of the observed effects via catecholaminergic receptors on chicken macrophages. Dopamine and NE (.25 micrograms/mL) did not affect but E exposure enhanced LPS-induced tumoricidal factor production. These findings suggest that CA modulate chicken macrophage effector functions.

Animals↗
PubMed1982

In vitro assay for predicting protein efficiency ratio as measured by rat bioassay: collaborative study.

Seven laboratories collaborated in testing the calculated protein efficiency ratio (C-PER and DC-PER). The collaborative study required each laboratory to analyze 6 foods and a control protein (ANRC casein) for in vitro apparent protein digestibility, amino acid composition, and PER via rat bioassay. The 6 foods or food ingredients tested were nonfat dry milk, cooked chicken muscle, protein-fortified dry breakfast cereal, textured soy protein, oat-based dry breakfast cereal, and durum wheat flour. Data obtained from the study were analyzed statistically for the intralaboratory variation for each method of analysis (i.e., amino acid analysis, PER, etc.). The ability of the C-PER to rapidly predict rat PER was also measured. The C-PER and DC-PER methods were adopted official first action.

Amino Acids↗