SEARCH · PubMed Health

Results for “AI”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 361 records · Page 20Linked to original sources

PubMed1998

[Seroepidemiology of Toxoplasma gondii infection among Atayal aborigines and local animals in Nan-ao district, Ilan county and Jen-ai district, Nan-tou county, Taiwan].

In this study, latex agglutination test (LAT) was used to detect sera anti-toxoplasma antibodies of Atayal aborigines and local animals in Nan-ao district, Ilan county and Jen-ai district, Nan-tou county as a measure of exposure to the Toxoplasma gondii. Out of 422 Atayal aborigines and 64 different animals were tested in Nan-ao district and 82 Atayal children in Jen-ai district were also screened, the positive rates for sera anti-toxoplasma antibodies were 21.8%, 17.2% and 15.9%, respectively. In Nan-ao district, neither were the positive rates significantly different in males (22.1%) and females (21.4%), nor in humans (21.8%) and dogs (19.6%) (P > 0.05). The seroprevalence in adults (28.3%) was significantly higher than that in children (18.7%) (P < 0.05), and the highest seropositive rate (38.1%) was in the age group 50-59 years and the lowest (7.7%) was in the age group 1-9 years. In general, the age pattern of prevalence is consistent with increasing duration of exposure to Toxoplasma gondii with age. For animals, the seropositive rate in dogs (19.6%) was also significantly higher than that in wild rats (7.7%) (P < 0.05). No significant difference in seropositive rate of Atayal children was observed between Nan-ao and Jen-ai districts (P > 0.05).

Adolescent↗

PubMed1996

Ageing and amyloid fibrillogenesis: lessons from apolipoprotein AI, transthyretin and islet amyloid polypeptide.

The age-associated (or senile) amyloidoses encompass a heterogeneous group of systemic or localized forms of amyloidosis. In this paper we present an overview of three age-associated amyloid forms derived from transthyretin, apolipoprotein AI and islet amyloid polypeptide. Mutations in the respective genes give rise to transthyretin and apolipoprotein AI forms of familial amyloidosis while senile forms of amyloid are associated with the wild-type proteins. Different mechanisms are probably of importance in the fibrillogenesis associated with these three amyloid types. It is also possible that different amyloidogenic pathways exist for a single amyloidogenic protein. Thus, limited proteolysis may be necessary in the fibrillogenesis in senile transthyretin amyloidosis but not in most familial transthyretin amyloidoses. Other factors in the pathogenesis of amyloidosis such as local concentration, nidus formation and glycation are also discussed.

Aging↗

PubMed2001

Layer V in cat primary auditory cortex (AI): cellular architecture and identification of projection neurons.

The cytoarchitectonic organization and the structure of layer V neuronal populations in cat primary auditory cortex (AI) were analyzed in Golgi, Nissl, immunocytochemical, and plastic-embedded preparations from mature specimens. The major cell types were characterized as a prelude to identifying their connections with the thalamus, midbrain, and cerebral cortex using axoplasmic transport methods. The goal was to describe the structure and connections of layer V neurons more fully. Layer V has three sublayers based on the types of neuron and their sublaminar projections. Four types of pyramidal and three kinds of nonpyramidal cells were present. Classic pyramidal cells had a long apical dendrite, robust basal arbors, and an axon with both local and corticofugal projections. Only the largest pyramidal cell apical dendrites reached the supragranular layers, and their somata were found mainly in layer Vb. Three types departed from the classic pattern; these were the star, fusiform, and inverted pyramidal neurons. Nonpyramidal cells ranged from large multipolar neurons with radiating dendrites, to Martinotti cells, with smooth dendrites and a primary trunk oriented toward the white matter. Many nonpyramidal cells were multipolar, of which three subtypes (large, medium, and small) were identified; bipolar and other types also were seen. Their axons formed local projections within layer V, often near pyramidal neurons. Several features distinguish layer V from other layers in AI. The largest pyramidal neurons were in layer V. Layer V neuronal diversity aligns it with layer VI (Prieto and Winer [1999] J. Comp. Neurol. 404:332--358), and it is consistent with the many connectional systems in layer V, each of which has specific sublaminar and neuronal origins. The infragranular layers are the source for several parallel descending systems. There were significant differences in somatic size among these projection neurons. This finding implies that diverse corticofugal roles in sensorimotor processing may require a correspondingly wide range of neuronal architecture.

Animals↗

PubMed1994

Laminar distribution and neuronal targets of GABAergic axon terminals in cat primary auditory cortex (AI).

The form, density, and neuronal targets of presumptive axon terminals (puncta) that were immunoreactive for gamma-aminobutyric acid (GABA) or its synthesizing enzyme, glutamic acid decarboxylase (GAD), were studied in cat primary auditory cortex (AI) in the light microscope. High-resolution, plastic-embedded material and frozen sections were used. The chief results were: 1) There was a three-tiered numerical distribution of puncta, with the highest density in layer Ia, an intermediate number in layers Ib-IVb, and the lowest concentration in layers V and VI, respectively. 2) Each layer had a particular arrangement: layer I puncta were fine and granular (less than 1 micron in diameter), endings in layers II-IV were coarser and more globular (larger than 1 micron), and layer V and VI puncta were mixed in size and predominantly small. 3) The form and density of puncta in every layer were distinctive. 4) Immunonegative neurons received, in general, many more axosomatic puncta than immunopositive cells, with the exception of the large multipolar (presumptive basket) cells, which invariably had many puncta in layers II-VI. 5) The number of puncta on the perikarya of GABAergic neurons was sometimes related to the number of puncta in the layer, and in other instances it was independent of the layer. Thus, while layer V had a proportion of GABAergic neurons similar to layer IV, it had only a fraction of the number of puncta; perhaps the intrinsic projections of supragranular GABAergic cells are directed toward layer IV, as those of infragranular GABAergic neurons may be. Since puncta are believed to be the light microscopic correlate of synaptic terminals, they can suggest how inhibitory circuits are organized. Even within an area, the laminar puncta patterns may reflect different inhibitory arrangements. Thus, in layer I the fine, granular endings could contact preferentially the distal dendrites of pyramidal cells in deeper layers. The remoteness of such terminals from the spike initiation zone contrasts with the many puncta on all pyramidal cell perikarya and the large globular endings on basket cell somata. Basket cells might receive feed-forward disinhibition, pyramidal cells feed-forward inhibition, and GABAergic non-basket cells would be the target of only sparse inhibitory axosomatic input. Such arrangements imply that the actions of GABA on AI neurons are neither singular nor simple and that the architectonic locus, laminar position, and morphological identity of a particular neuron must be integrated for a more refined view of its role in cortical circuitry.

Animals↗

PubMed2006

Reference distributions for apolipoproteins AI and B and B/AI ratios: comparison of a large cohort to the world's literature.

Limiting the clinical utility of apolipoproteins AI (apo AI) and B (apo B) and the apo B/AI ratios until the last decade has been the lack of satisfactory methods for quantifying serum levels and credible reference materials. Great technological strides have been made in the last few years. The remaining barrier to more relevant and cost-effective use of serum protein data for diagnosis and prognosis has been the availability of widely recognized reliable reference intervals from birth to old age for both males and females. A total of 82 publications reporting reference intervals have been identified that meet most of the same inclusion criteria used in our prior six studies. These have been analyzed statistically and compared to similar studies, i.e., sufficient number, listed subject criteria, method, and reference material, in general terms. Published smaller studies with constrained age ranges, agree on average with our large series of life-long reference intervals that range from less than one year to over 80 years. This study was performed to assess the degree of agreement between smaller reference interval studies to our large population analysis. This meta-analysis provides support and reassurance that many of the smaller reference intervals published previously fall within reasonable limits of out large population.

Age Distribution↗

PubMed2026

AI-Based 3D Heterogeneous Network Model for Functional Prediction of Epigenetics.

Human biology and diseases are the result of constantly evolving processes within an intricately complex molecular network of interactions, such as epigenetic regulation. Epigenetics refers to heritable changes in gene expression that occur without alterations to the underlying DNA sequence. These changes, driven by mechanisms such as DNA methylation, histone modifications, and noncoding RNAs, play critical roles in regulating chromatin structure and gene activity. Epigenetic regulation offers valuable insights into biological systems, and when integrated with sophisticated analyses, it enables us to gain insights into gene regulation and cellular behavior. Here, we describe an artificial intelligence (AI)-based model that is capable of generating 3-dimensional (3D) heterogeneous network by integrating multimodal data for the functional prediction of epigenetic mechanisms, emphasizing its applications in medicine, developmental biology, and personalized therapeutics. Heterogeneous networks in biology are powerful tools for understanding the complex interactions and interdependencies within biological systems. Key advancements in AI and multiomics data integration have propelled this field, offering new insights into disease mechanisms, biomarker discovery, and therapeutic interventions.

Epigenesis, Genetic↗

PubMed1994

Extracoronary atherosclerosis and genetic variants of apolipoprotein AI-CIII cluster in myocardial infarction survivors from southern Italy.

The relationships between some genetic markers, as evaluated by DNA analysis, and ultrasound evidence of extracoronary athero-sclerosis, as detected by ultrasound methods, were evaluated in 39 myocardial infarction survivors of middle age and in 40 healthy controls of comparable age. Coronary heart disease (CHD) patients showed higher levels of triglycerides (P = 0.01) and greater number of exsmokers (P = 0.004). Carotid stenoses (> 15%) were detected in ten CHD patients and in two controls; iliac stenoses (> 15%) or abnormal ankle/arm ratio (< 0.97) were found in ten CHD patients and in one control; the scores of vascular disease severity in the myocardial infarction survivors were higher (Mann-Whitney test) than in controls (P < 0.01). Molecular genetic analysis of SstI restriction fragment length polymorphism (RFLP) of the apolipoprotein (apo) AI-CIII cluster and of the apo B gene demonstrated a higher frequency of the S2 allele (SstI RFLP) in coronary patients than in controls (P = 0.04) and no significant differences in the frequencies of XbaI RFLP of the apo B gene between patients and controls. The relative risk of myocardial infarction associated with an abnormal vascular score (> 8) or with the presence of the rare allele S2 (SstI apo AI-CIII polymorphism) was estimated by odds ratios. The lower 95% limits of odds ratios were above 1 (indicating significant increase in the relative risk of myocardial infarction) both in the case of vascular score and that of SstI RFLP. These associations were independent of one another and of triglyceride levels. SstI RFLP association with CHD disappeared after adjustment for smoking habits.(ABSTRACT TRUNCATED AT 250 WORDS)

Apolipoprotein A-I↗

PubMed1994

AI-based approach to automatic sleep classification.

The primary goal of this paper is to introduce the potential of artificial intelligence (AI) methods to researchers in sleep classification. AI provides learning procedures for the construction of a sleep classifier, prescribing how to combine the observed parameters and how to derive the corresponding decision thresholds. A case study reporting a successful application of an automatic induction of decision trees and of a learning vector quantizer to this domain is presented.

Artificial Intelligence↗

PubMed1993

Linkage disequilibrium of three polymorphic RFLP markers in the apolipoprotein AI-CIII gene cluster on chromosome 11.

We analysed the allelic and genotypic frequencies of three restriction fragment length polymorphisms in the region of chromosome 11 encoding apolipoprotein AI and CIII genes in a free-living population from South Italy (Calabria). These markers are located at -2500 and -78 bp from the transcription start site of apolipoprotein AI gene (XmnI and MspI, respectively), and in the 3' untranslated region of apolipoprotein CIII gene (SstI). XmnI and SstI label rare alleles (X2 and S2 indicate the presence of the site), whereas the absence of the MspI site (because of a G to A transition) marks the rare allele, M2. Pairwise linkage disequilibrium analysis was determined. Two significant non-random associations were found: a positive disequilibrium between ApoA1/XmnI and ApoA1/MspI markers (P < 0.0001), and a negative disequilibrium between ApoA1/XmnI and ApoC3/SstI markers (P < 0.05). Statistical analysis showed a significant difference in the S2-M2 haplotype frequency between the group of subjects with serum cholesterol levels in the highest decile (P < 0.005) and the group with serum cholesterol levels below the highest decile. The allelic frequency for each locus showed no significant difference between the two groups for all other metabolic parameters, included total cholesterol serum levels. These haplotypes are a more precise measure of genetic variations in the apolipoprotein cluster and their use should allow the mapping of mutations responsible for high serum cholesterol levels.

Adult↗

PubMed1995

Apolipoprotein AI-CIII-AIV genetic polymorphisms and coronary heart disease in type 2 diabetes mellitus.

The aim of this study was to verify whether or not the increased prevalence of coronary heart disease (CHD) commonly observed in patients with type 2 diabetes mellitus is related to a genetic background involving restriction fragment length polymorphisms (RFLPs) of apolipoproteins. On the basis of a case-control design, 62 type 2 diabetic patients with CHD (confirmed by clinical history and electrocardiogram) and 62 age- and sex-matched diabetic subjects without CHD were enrolled. In each of them RFLPs of the apolipoprotein CIII gene (S1 or S2 allele) and AI promoter region (A or G allele), together with fasting plasma lipids and apolipoproteins levels, were assessed. The rare S2 allele was found significantly (P = 0.05) more frequently in patients with CHD, and its related S1S2 genotype was associated with higher plasma levels of total cholesterol (P = 0.01), triglycerides (P = 0.007) and apo B (P = 0.001) than the S1S1 genotype. The A allele was more frequent (P = 0.004) in patients without CHD and was associated with lower plasma cholesterol (P = 0.0001), low-density lipoprotein (LDL)-cholesterol (P = 0.0001) and apo B (P = 0.005). The S1/A haplotype was more frequent (P = 0.05) in patients without CHD and was associated with the lowest plasma lipid levels. These results suggest that genetic factors, related to the apo AI-CIII-AIV gene cluster, could play a role in the development of CHD in type 2 diabetic patients, probably through modification of their plasma lipid pattern.

Alleles↗

PubMed1996

Apolipoprotein AIV of human interstitial fluid is associated with apolipoprotein AI-containing but not with AII-containing particles.

Apolipoproteins and lipoprotein particles from human interstitial fluid and plasma were analyzed. The interstitial fluid was enriched in apolipoproteins AI, AII, and AIV compared with apo B, apo CIII, and apo E, LpAI was found to contain apo AIV which was absent from LpAI: AII. Moreover, the bulk of lecithin-cholesterol acyl-transferase was present in LpAI. The concentration range of these particles was in agreement with those required in vitro for cholesterol efflux. Thus the interstitial fluid contains particles in which two agonists but no antagonists of cholesterol efflux are associated with lecithin-cholesterol acyltransferase activity. This supports apolipoprotein AI- and/or AIV-containing particles playing a critical role in the first step of reverse cholesterol transport.

Adult↗

PubMed2004

Platelet calmodulin levels in adolescent idiopathic scoliosis (AIS): can they predict curve progression and severity? Summary of an electronic focus group debate of the IBSE.

There is no generally accepted scientific theory for the etiology of idiopathic scoliosis. As part of its mission to widen understanding of scoliosis etiology, the International Federated Body on Scoliosis Etiology (IBSE) introduced the electronic focus group (EFG) as a means of increasing debate of extant knowledge on important topics. This has been designated as an on-line Delphi discussion. The text for this EFG was written by Professor Thomas G Lowe MD and drawn from research carried out by himself and his co-workers on platelet calmodulin levels in patients with adolescent idiopathic scoliosis. To explain the relationship of platelet calmodulin levels to scoliosis curve changes in AIS brought about spontaneously, by brace treatment, or surgery Dr Lowe attributes the platelet calmodulin changes to paraspinous muscle activity and suggests that the calmodulin acts as a systemic mediator of tissues having a contractile system (actin and myosin). Controversy includes: 1) the lack of normal data and the large variability in baseline levels of platelet calmodulin, necessitating the use of the AIS subjects as their own controls; 2) calmodulin is not usually used as a marker of platelet activation; 3) whether the platelet calmodulin changes which appear to reflect an abnormality of a portion of the spine are related to local and/or regional changes in muscles, nervous system, or immature vertebrae. What is not controversial is the need for more research on platelets and the immature deforming skeleton in relation to etiology and prognosis.

Adolescent↗

PubMed2003

The Ai project: historical and ecological contexts.

This paper aims to review a long-term research project exploring the chimpanzee mind within historical and ecological contexts. The Ai project began in 1978 and was directly inspired by preceding ape-language studies conducted in Western countries. However, in contrast with the latter, it has focused on the perceptual and cognitive capabilities of chimpanzees rather than communicative skills between humans and chimpanzees. In the original setting, a single chimpanzee faced a computer-controlled apparatus and performed various kinds of matching-to-sample discrimination tasks. Questions regarding the chimpanzee mind can be traced back to Wolfgang Koehler's work in the early part of the 20th century. Yet, Japan has its unique natural and cultural background: it is home to an indigenous primate species, the Japanese snow monkey. This fact has contributed to the emergence of two previous projects in the wild led by the late Kinji Imanishi and his students. First, the Koshima monkey project began in 1948 and became famous for its discovery of the cultural propagation of sweet-potato washing behavior. Second, pioneering work in Africa, starting in 1958, aimed to study great apes in their natural habitat. Thanks to the influence of these intellectual ancestors, the present author also undertook the field study of chimpanzees in the wild, focusing on tool manufacture and use. This work has demonstrated the importance of social and ecological perspectives even for the study of the mind. Combining experimental approaches with a field setting, the Ai project continues to explore cognition and behavior in chimpanzees, while its focus has shifted from the study of a single subject toward that of the community as a whole.

Adaptation, Psychological↗

PubMed1985

Isolation and structure elucidation of an alpha-amylase inhibitor, AI-3688, from Streptomyces aureofaciens.

A novel polypeptide inhibitor, AI-3688, which acts upon human pancreatic alpha-amylase, was isolated from fermentation broth of Streptomyces aureofaciens. The purified peptide contains no unusual amino acids. Its Mr is 3936. The primary structure of AI-3688 was elucidated by automatic Edman degradation of the native or modified inhibitor. Two intramolecular cysteines form a disulphide bridge, thus creating a ring structure consisting of 17 amino acids. Strong sequence homology also exists to another microbial alpha-amylase inhibitor, tendamistat (HOE 467). This paper discusses the role of a common partial sequence, -Gln-Ser-Trp-Arg-Tyr-, present in the loop of both inhibitors as the active site of microbial peptide alpha-amylase inhibitors.

Amino Acid Sequence↗

PubMed1988

Variations in the apolipoprotein AI-CIII-AIV gene region and in lecithin:cholesterol acyltransferase concentration are determinants of plasma cholesterol concentrations.

We have examined the effects of variation in the region of the apolipoprotein (apo) AI-CII-AIV genes, and in plasma lecithin: cholesterol acyltransferase (LCAT) concentration, on plasma cholesterol concentration in 109 unrelated men aged 52-67 yrs. Restriction fragment length polymorphisms (RFLPs) were detected using the restriction enzymes XmnI, PstI and SstI and individuals were divided into groups using information from all three RFLPs in conjunction. Mean plasma concentrations of both total cholesterol and estimated low density lipoprotein-cholesterol differed significantly (P less than 0.0125) among groups of men with different genotypes. Thus, variation in this gene region may be one of the polygenetic factors involved in determining cholesterol levels in the normal population. In the same subjects, plasma cholesterol was also positively correlated with plasma LCAT concentration (r = 0.55, P less than 0.001), due mainly to an increase in the cholesteryl ester content of apo B-containing lipoproteins with increasing LCAT concentration. Since apolipoproteins AI, CIII and AIV have each been shown to modify the activity of LCAT in vitro, the associations of the RFLPs with plasma cholesterol concentration may reflect changes in LCAT activity secondary to qualitative or quantitative changes in one or more of these apolipoproteins.

Aged↗

PubMed1981

Relation between the HDL apoproteins and AI isoproteins in subjects with the AIMilano abnormality.

The apoprotein AIMilano (AIM) is the first described molecular abnormality of human apolipoproteins. In order to achieve a better understanding of the biochemical role of high density lipoproteins (HDL) and of their subcomponents, nine members of the AIM family were studied. Five showed the characteristic biochemical features of the AIM abnormality. All were hypertriglyceridemic; their plasma and very low density lipoprotein (VLDL) triglycerides had a significant negative correlation with the HDL cholesterol (HDL-C) levels (r = -0.961, p less than 0.01 and r = -0.939, p less than 0.05, respectively). Compositional studies of HDL in these subjects revealed a marked triglyceride (TG) enrichment, with reduced cholesterol content. HDL-C and/or phospholipid (PL) levels correlated significantly with the AIM apoprotein in HDL (r = 0.995, p less than 0.001 for HDL-C and r = 0.994, p less than 0.001 for HDL-PL) but not with the other HDL apoproteins, suggesting that only apo AIM in monomeric form, can bind lipids. Isoelectric focusing studies on the isolated AIM isoproteins from the five affected subjects revealed an isoprotein distribution markedly different from normal AI. A possible structural role for isoprotein AI1 is suggested by the strong correlation between HDL content of this isoprotein and HDL-C and HDL-PL levels (r = 0.965 and r = -0.990 respectively, both p less than 0.001). AI4 and AIM was nearly doubled, as compared to normal AI. The reported results may be of help for a better understanding of the role of the major HDL apoprotein and of its isoproteins in lipid binding and lipoprotein metabolism.

Adolescent↗

PubMed1988

Transmission of bovine virus diarrhoea virus (BVDV) by artificial insemination (AI) with semen from a persistently-infected bull.

Twelve heifers that did not have antibodies to bovine virus diarrhoea virus (BVDV) were inseminated with semen from a bull that was persistently infected with the virus and contained 10(4.0)-10(6.5) TCID50 0.1 ml-1. All 12 became infected, as indicated by seroconversion within 2 weeks of insemination. Four control heifers were inseminated with virus-free semen. The virus was not transmitted to these animals in spite of close contact with the heifers inseminated with the infected semen. All the heifers became pregnant and gave birth to clinically normal calves at term. However, one calf was born persistently infected with BVDV. After the birth of this persistently-infected calf the control heifers and their calves seroconverted. The study demonstrates that BVDV may be transmitted in cattle by artificial insemination (AI). Therefore entry of persistently-infected animals into AI centres should be prevented.

Animals↗

PubMed1985

Binaural interactions in cortical area AI of cats reared with unilateral atresia of the external ear canal.

Binaural interactions were recorded in auditory cortical (AI) neurons of anesthetized adult cats that had unilateral atresias created shortly after birth by surgically ligating and cutting one external ear canal. At the time of the recording experiment, the atresia and associated debris were removed and tones were delivered to both tympanic membranes via a sealed and calibrated acoustic system. The majority of neurons recorded were in the cortex ipsilateral to the previously occluded ear. Thresholds for monaural stimulation of either the operated or unoperated ear were within normal range although thresholds to stimulation of the previously operated ear tended to occupy the upper end of the normal distribution. Monotonic and nonmonotonic spike count-vs-intensity functions derived from responses to monaural stimulation of the atretic ear were indistinguishable in their shape from those recorded in normal cats. All binaural classes were represented in our sample in proportions similar to those reported in cats with two normal ears. The forms of the functions relating spike count to interaural intensity differences and interaural phase differences were essentially the same as those seen in normal animals. The main binaural deficit observed under these conditions was a shift in the interaural intensity difference to which an AI neuron was most sensitive. The intensity needed for a stimulus to the atretic ear to participate in the binaural response was as much as 50 dB higher than that at the opposite normal ear in contrast to the nearly equal SPLs required for binaural interactions in cats with two ears intact. It was suggested that elevated thresholds at the previously operated ear could account for much of the shift observed.

Action Potentials↗