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1.
Nutrients ; 15(13)2023 Jun 30.
Article in English | MEDLINE | ID: mdl-37447302

ABSTRACT

SARS-CoV-2 vaccination promises to improve outcomes for patients with COVID-19 pneumonia (most notably those with advanced age and at high risk for severe disease). Here, we examine serum 25-Hydroxyvitamin D (25(OH)D) status and outcomes in both old (>70 years) and young vaccinated (n = 80) and unvaccinated (n = 91) subjects, who were hospitalized due to COVID-19 pneumonia in a single center (Connolly Hospital Dublin). Outcomes included ICU admission and mortality. Serum 25(OH)D levels were categorized as D30 (<30 nmol/L), D40 (30-49.99 nmol/L) and D50 (≥50 nmol/L). In multivariate analyses, D30 was independently associated with ICU admission (OR: 6.87 (95% CI: 1.13-41.85) (p = 0.036)) and mortality (OR: 24.81 (95% CI: 1.57-392.1) (p = 0.023)) in unvaccinated patients, even after adjustment for major confounders including age, sex, obesity and pre-existing diabetes mellitus. While mortality was consistently higher in all categories of patients over 70 years of age, the highest observed mortality rate of 50%, seen in patients over 70 years with a low vitamin D state (D30), appeared to be almost completely corrected by either vaccination, or having a higher vitamin D state, i.e., mortality was 14% for vaccinated patients over 70 years with D30 and 16% for unvaccinated patients over 70 years with a 25(OH)D level greater than 30 nmol/L. We observe that high mortality from COVID-19 pneumonia occurs in older patients, especially those who are unvaccinated or have a low vitamin D state. Recent vaccination or having a high vitamin D status are both associated with reduced mortality, although these effects do not fully mitigate the mortality risk associated with advanced age.


Subject(s)
COVID-19 Vaccines , COVID-19 , Humans , Aged , Aged, 80 and over , SARS-CoV-2 , COVID-19/prevention & control , Vitamin D , Vitamins , Hospitals , Vaccination
2.
R Soc Open Sci ; 10(7): 230451, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37448478

ABSTRACT

Dietary variation within and across species drives the eco-evolutionary responsiveness of genes necessary to metabolize nutrients and other components. Recent evidence from humans and other mammals suggests that sugar-rich diets of floral nectar and ripe fruit have favoured mutations in, and functional preservation of, the ADH7 gene, which encodes the ADH class 4 enzyme responsible for metabolizing ethanol. Here we interrogate a large, comparative dataset of ADH7 gene sequence variation, including that underlying the amino acid residue located at the key site (294) that regulates the affinity of ADH7 for ethanol. Our analyses span 171 mammal species, including 59 newly sequenced. We report extensive variation, especially among frugivorous and nectarivorous bats, with potential for functional impact. We also report widespread variation in the retention and probable pseudogenization of ADH7. However, we find little statistical evidence of an overarching impact of dietary behaviour on putative ADH7 function or presence of derived alleles at site 294 across mammals, which suggests that the evolution of ADH7 is shaped by complex factors. Our study reports extensive new diversity in a gene of longstanding ecological interest, offers new sources of variation to be explored in functional assays in future study, and advances our understanding of the processes of molecular evolution.

3.
Nutrients ; 14(16)2022 Aug 09.
Article in English | MEDLINE | ID: mdl-36014757

ABSTRACT

COVID-19 and a low vitamin D state share common risk factors, which might explain why vitamin D deficiency has been linked with higher COVID-19 mortality. Moreover, measures of serum vitamin D may become lower during systemic inflammatory responses, further confounding the association via reverse causality. In this prospective study (recruited over 12 months), we examined whether the association between a low vitamin D state and in-hospital mortality due to SARS-CoV-2 pneumonia in unvaccinated subjects is explained by (i) the presence of shared risk factors (e.g., obesity, advanced age) or (ii) a reduction in serum 25(OH)D due to COVID-19 (i.e., reverse causality). In this cohort of 232 (mean age = 56 years) patients (all had SARS-CoV-2 diagnosed via PCR AND required supplemental oxygen therapy), we failed to find an association between serum vitamin D and levels of CRP, or other inflammatory markers. However, the hazard ratio for mortality for subjects over 70 years of age (13.2) and for subjects with a serum 25(OH)D level less than 30 nmol·L−1 (4.6) remained significantly elevated even after adjustment for gender, obesity and the presence of diabetes mellitus. Subjects <70 years and >70 years had significantly higher mortality with a serum 25(OH)D less than 30 nmol·L−1 (11.8% and 55%), than with a serum 25(OH)D greater than 30 nmol·L−1 (2.2% and 25%). Unvaccinated Caucasian adults with a low vitamin D state have higher mortality due to SARS CoV-2 pneumonia, which is not explained by confounders and is not closely linked with elevated serum CRP.


Subject(s)
COVID-19 , Vitamin D Deficiency , Adult , Aged , Aged, 80 and over , Humans , Middle Aged , Obesity , Prospective Studies , SARS-CoV-2 , Vitamin D , Vitamins
4.
Am J Primatol ; 83(2): e23230, 2021 02.
Article in English | MEDLINE | ID: mdl-33475188

ABSTRACT

Primates' predators, such as carnivore mammals, usually rely on camouflage to increase proximity to prey and start a predatory attempt. Camouflage depends not only on the color pattern presented by a predator's pelage but also on the background scene in which the hunting takes place. Another factor that influences camouflage effectiveness is prey's color vision since a given camouflage strategy might not work for all visual phenotypes. Still, little research has been made on the effect of primate visual phenotype on predator detection. Here, we investigate the effects of natural pelages, background scenarios, visual phenotypes, and detection distances on predator detection. We used photographs of taxidermized carnivores (ocelots, cougars, and lesser grisons) as detection stimuli, taken in three different natural scenarios (forest, savanna, and grassland), and at two viewing distances (near and far). On a touchscreen monitor, sets of four images (only one containing a hidden animal) were randomly presented to 39 human males (19 dichromats and 20 trichromats). We found that trichromats, when compared to dichromats, present a lower latency and a higher accuracy of carnivore detection for some conditions tested. We also found that pelage color, background scenario, and detection distance interact to influence the effectiveness of camouflage. Our results suggest that trichromacy might be even more advantageous for carnivore detection than thought before, since it facilitates detection of mammals with diverse pelage colorations, in environments with different phytophysiognomies, and at longer distances. We also propose that the higher rates of dichromacy found in modern human societies could have resulted from a relaxation in predation.


Subject(s)
Biological Mimicry , Color Vision , Predatory Behavior , Adult , Animals , Biological Evolution , Carnivora , Color Vision Defects , Humans , Male
5.
Am J Primatol ; 82(12): e23199, 2020 12.
Article in English | MEDLINE | ID: mdl-32990997

ABSTRACT

Vision is a major sense for Primates and the ability to perceive colors has great importance for the species ecology and behavior. Visual processing begins with the activation of the visual opsins in the retina, and the spectral absorption peaks are highly variable among species. In most Primates, LWS/MWS opsins are responsible for sensitivity to long/middle wavelengths within the visible light spectrum, and SWS1 opsins provide sensitivity to short wavelengths, in the violet region of the spectrum. In this study, we aimed to investigate the genetic variation on the sws1 opsin gene of New World monkeys (NWM) and search for amino acid substitutions that might be associated with the different color vision phenotypes described for a few species. We sequenced the exon 1 of the sws1 opsin gene of seven species from the families Callitrichidae, Cebidae, and Atelidae, and searched for variation at the spectral tuning sites 46, 49, 52, 86, 90, 93, 114, 116, and 118. Among the known spectral tuning sites, only residue 114 was variable. To investigate whether other residues have a functional role in the SWS1 absorption peak, we performed computational modeling of wild-type SWS1 and mutants A50I and A50V, found naturally among the species investigated. Although in silico analysis did not show any visible effect caused by these substitutions, it is possible that interactions of residue 50 with other sites might have some effect in the spectral shifts in the order of ~14 nm, found among the NWM. We also performed phylogenetic reconstruction of the sws1 gene, which partially recovered the species phylogeny. Further studies will be important to uncover the mutations responsible for the phenotypic variability of the SWS1 of NWM, and how spectral tuning may be associated with specific ecological features such as preferred food items and habitat use.


Subject(s)
Cone Opsins/genetics , Genetic Variation , Animals , Phylogeny , Platyrrhini , Sequence Analysis, DNA/veterinary
6.
Insects ; 11(2)2020 Feb 01.
Article in English | MEDLINE | ID: mdl-32024068

ABSTRACT

Deployment of Aedes aegypti mosquitoes carrying the endosymbiont bacterium Wolbachia has been identified as a promising strategy to reduce dengue, chikungunya, and Zika transmission. We investigated whether sampling larvae from ovitraps can provide reliable estimates on Wolbachia frequency during releases, as compared to the expensive adult-based BG-Sentinel. We conducted pilot releases in a semi-field system (SFS) divided into six cages of 21 m2, each with five ovitraps. Five treatments were chosen to represent different points of a hypothetical invasion curve: 10%, 25%, 50%, 75%, and 90% of Wolbachia frequency. Collected eggs were counted and hatched, and the individuals from a net sample of 27% of larvae per treatment were screened for Wolbachia presence by RT-qPCR. Ovitrap positioning had no effect on egg hatching rate. Treatment strongly affected the number of eggs collected and also the hatching rate, especially when Wolbachia was at a 10% frequency. A second observation was done during the release of Wolbachia in Rio under a population replacement approach when bacterium frequency was estimated using 30 BG-Sentinel traps and 45 ovitraps simultaneously. By individually screening 35% (N = 3904) of larvae collected by RT-qPCR, we were able to produce a similar invasion curve to the one observed when all adults were individually screened. If sampling is reduced to 20%, monitoring Wolbachia frequency with 45 ovitraps would be roughly half the cost of screening all adult mosquitoes captured by 30 BG-Sentinels. Our findings support the scale-up of Wolbachia releases, especially in areas with limited resources to afford massive trapping with BG-Sentinel traps.

7.
Am J Primatol ; 81(3): e22963, 2019 03.
Article in English | MEDLINE | ID: mdl-30809840

ABSTRACT

Most species of New World primates have an unusual color vision pattern that can affect an individual's ability to detect food. Whereas males can only be dichromatic, females can be either dichromatic or trichromatic. Trichromats are expected to have an advantage in detecting conspicuous food whereas dichromats should be better at locating cryptic resources. Here we aimed to understand how color vision phenotype influences insect foraging by five groups of common marmosets living in a semiarid environment. We recorded insect predation events, noting morphotype and color of the captured insect, and the substrate from which it was captured. Color modeling suggested that, for all values of chromatic contrast resulting from comparing the measured insect-substrate pairs, trichromats outperformed dichromats. Females showed an overall higher insect capture rate than males. Females also showed a higher capture rate of conspicuous insects but there was no sex difference for the capture of cryptic insects. When we compared only dichromatic individuals there was no difference between sexes. These findings suggest that differences found in capture rate related not only to sex but also to visual polymorphism and that the latter is a crucial factor determining insect capture rate in common marmosets. Nevertheless, these results should be interpreted with caution because of the small number (three) of dichromat females and the unknown phenotype of the remaining females. Our results support the balancing selection hypothesis, suggesting that the advantage of one phenotype over the other may depend on environmental circumstances. This hypothesis has recently been considered as the most plausible for the maintenance of visual polymorphism in New World primates.


Subject(s)
Appetitive Behavior/physiology , Callithrix/physiology , Color Vision , Animals , Brazil , Color , Female , Insecta , Male , Sex Characteristics
8.
Mol Ecol ; 27(18): 3627-3640, 2018 09.
Article in English | MEDLINE | ID: mdl-30059176

ABSTRACT

Bats are a diverse radiation of mammals of enduring interest for understanding the evolution of sensory specialization. Colour vision variation among species has previously been linked to roosting preferences and echolocation form in the suborder Yinpterochiroptera, yet questions remain about the roles of diet and habitat in shaping bat visual ecology. We sequenced OPN1SW and OPN1LW opsin genes for 20 species of leaf-nosed bats (family Phyllostomidae; suborder Yangochiroptera) with diverse roosting and dietary ecologies, along with one vespertilionid species (Myotis lavali). OPN1LW genes appear intact for all species, and predicted spectral tuning of long-wavelength opsins varied among lineages. OPN1SW genes appear intact and under purifying selection for Myotis lavali and most phyllostomid bats, with two exceptions: (a) We found evidence of ancient OPN1SW pseudogenization in the vampire bat lineage, and loss-of-function mutations in all three species of extant vampire bats; (b) we additionally found a recent, independently derived OPN1SW pseudogene in Lonchophylla mordax, a cave-roosting species. These mutations in leaf-nosed bats are independent of the OPN1SW pseudogenization events previously reported in Yinpterochiropterans. Therefore, the evolution of monochromacy (complete colour blindness) has occurred in both suborders of bats and under various evolutionary drivers; we find independent support for the hypothesis that obligate cave roosting drives colour vision loss. We additionally suggest that haematophagous dietary specialization and corresponding selection on nonvisual senses led to loss of colour vision through evolutionary sensory trade-off. Our results underscore the evolutionary plasticity of opsins among nocturnal mammals.


Subject(s)
Caves , Chiroptera/physiology , Color Vision , Diet/veterinary , Evolution, Molecular , Animals , Brazil , Chiroptera/genetics , Opsins/genetics , Phylogeny
9.
Behav Processes ; 142: 33-39, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28528929

ABSTRACT

Conspicuous colouration is an important way of social communication in many taxa. The role of ultraviolet (UV) signals in intraspecific communication has only recently been studied in lizards, and there is not a general understanding of the adaptive role of UV colouration. Colour ornaments can signal male quality in mate choice and are therefore suitable for reliably predicting the outcome of female preference. Here, we tested the potential role of UV colouration in female spatial preference in a non-territorial teiid lizard, Cnemidophorus ocellifer. We experimentally manipulated the UV reflectance of size-matched male pairs and tested the effects of our treatment on females' spatial distribution. We found that females associated with males of higher UV reflectance, suggesting that UV colour can be an important clue during mate preference decisions. Our results provide the first empirical evidence for the importance of UV colouration in female preference in a mutually ornamented lizard species.


Subject(s)
Color , Lizards/physiology , Mating Preference, Animal/physiology , Sexual Behavior, Animal/physiology , Animals , Brazil , Female , Male
10.
Behav Processes ; 109 Pt A: 64-9, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25153795

ABSTRACT

Bats are known for their well-developed echolocation. However, several experiments focused on the bat visual system have shown evidence of the importance of visual cues under specific luminosity for different aspects of bat biology, including foraging behavior. This study examined the foraging abilities of five female great fruit-eating bats, Artibeus lituratus, under different light intensities. Animals were given a series of tasks to test for discrimination between a food target against an inedible background, under light levels similar to the twilight illumination (18lx), the full moon (2lx) and complete darkness (0lx). We found that the bats required a longer time frame to detect targets under a light intensity similar to twilight, possibly due to inhibitory effects present under a more intense light level. Additionally, bats were more efficient at detecting and capturing targets under light conditions similar to the luminosity of a full moon, suggesting that visual cues were important for target discrimination. These results demonstrate that light intensity affects foraging behavior and enables the use of visual cues for food detection in frugivorous bats. This article is part of a Special Issue entitled: Neotropical Behaviour.


Subject(s)
Chiroptera/psychology , Feeding Behavior/psychology , Light , Animals , Cues , Darkness , Discrimination, Psychological , Female , Male , Visual Perception
11.
Br J Nutr ; 110(11): 2084-97, 2013 Dec 14.
Article in English | MEDLINE | ID: mdl-23721781

ABSTRACT

The present study aimed to investigate socio-economic disparities in food and nutrient intakes among young Irish women. A total of 221 disadvantaged and seventy-four non-disadvantaged women aged 18-35 years were recruited. Diet was assessed using a diet history protocol. Of the total population, 153 disadvantaged and sixty-three non-disadvantaged women were classified as plausible dietary reporters. Food group intakes, nutrient intakes and dietary vitamin and mineral concentrations per MJ of energy consumed were compared between the disadvantaged and non-disadvantaged populations, as was compliance with dietary fibre, macronutrient and micronutrient intake guidelines. The disadvantaged women had lower intakes than the non-disadvantaged women of fruit, vegetables, fish, breakfast cereals, low-fat milk and wholemeal bread (all P< 0·001), yogurt (P= 0·001), low-fat spread (P= 0·002) and fresh meat (P= 0·003). They also had higher intakes of butter, processed red meats, white bread, sugar-sweetened beverages, fried potatoes and potato-based snacks (all P< 0·001) and full-fat milk (P= 0·014). Nutritionally, the disadvantaged women had higher fat, saturated fat and refined sugar intakes; lower dietary fibre, vitamin and mineral intakes; and lower dietary vitamin and mineral densities per MJ than their more advantaged peers. Non-achievement of carbohydrate (P= 0·017), fat (P< 0·001), saturated fat (P< 0·001), refined sugar (P< 0·001), folate (P= 0·050), vitamin C (P< 0·001), vitamin D (P= 0·047) and Ca (P= 0·019) recommendations was more prevalent among the disadvantaged women. Both groups showed poor compliance with Fe and Na guidelines. We conclude that the nutritional deficits present among these socially disadvantaged women are significant, but may be potentially ameliorated by targeted food-based interventions.


Subject(s)
Diet/adverse effects , Feeding Behavior , Health Promotion , Nutrition Policy , Patient Compliance , Adolescent , Adult , Cohort Studies , Deficiency Diseases/epidemiology , Deficiency Diseases/ethnology , Deficiency Diseases/etiology , Diet/ethnology , Feeding Behavior/ethnology , Female , Humans , Ireland/epidemiology , Nutritive Value , Patient Compliance/ethnology , Risk , Socioeconomic Factors , Trace Elements/administration & dosage , Urban Health/ethnology , Vitamins/administration & dosage , Vulnerable Populations/ethnology , Young Adult
12.
Folia Primatol (Basel) ; 79(3): 172-84, 2008.
Article in English | MEDLINE | ID: mdl-18212502

ABSTRACT

Squirrel monkeys, like most Neotropical primates, display a sex-linked colour vision polymorphism. Here we assess the colour perception of 8 Saimiri ustus by a behavioural paradigm using Munsell colour chips as discriminating stimuli. A random variation in brightness assured that discriminations were based on colour rather than brightness cues. Results indicate that all males showed random performances when presented with stimuli which, in previous experiments with human colour-blind individuals and dichromatic non-human primates, proved to be difficult to discriminate. Females behaved as trichromats. The different phenotypes in S. ustus may offer diverse advantages in feeding ecology and are in agreement with the existence of vision polymorphism, as described for other species of squirrel monkeys.


Subject(s)
Color Perception/genetics , Polymorphism, Genetic , Saimiri/genetics , Animals , Behavior, Animal , Color Vision Defects/genetics , Female , Humans , Male , Phenotype , Sex Characteristics
13.
Am J Primatol ; 67(4): 437-46, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16342073

ABSTRACT

Large-field trichromacy is a general feature of protanope and deuteranope humans, provided that the stimuli size extends to an 8 degrees visual angle. In this study we compared the performance of five male and three female tufted capuchin monkeys (Cebus apella) in discriminating pairs of Munsell color papers. Human subjects were also studied in two-choice discrimination tests, using the same stimuli and apparatus employed for the monkeys. The results show that although the dichromatic humans showed improved discrimination with larger versions of the stimuli, the dichromatic monkeys exhibited the same performance for both stimuli sizes. Thus, Cebus apella apparently do not present large-field trichromacy-at least for the conditions in the present experiments.


Subject(s)
Cebus/physiology , Color Perception , Adult , Animals , Discrimination, Psychological , Female , Humans , Male , Middle Aged , Size Perception
14.
Am J Primatol ; 67(4): 487-95, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16342075

ABSTRACT

Here we demonstrate differences in the relative performance of 15 callitrichids tested in a series of color visual discrimination experiments. Munsell color chips were chosen as stimuli based on their use in earlier experiments with human dichromats. We show behavioral evidence for the existence of four distinct kinds of color-vision phenotypes, each of which has slightly different color discrimination abilities. The different phenotypes may offer different advantages. The data are in accordance with the existence of a visual polymorphism in callitrichids.


Subject(s)
Callithrix/physiology , Color Perception , Leontopithecus/physiology , Saguinus/physiology , Animals , Behavior, Animal , Discrimination Learning , Female , Male , Phenotype , Vision Tests
15.
Folia Primatol (Basel) ; 76(3): 125-34, 2005.
Article in English | MEDLINE | ID: mdl-15900100

ABSTRACT

The dietary diversity of marmosets is substantial, which may reflect differences in their colour vision. This study examined the colour discrimination ability of a gummivore/insectivore callitrichid, Callithrix penicillata, which inhabits the Brazilian cerrado (bush savanna). A series of ecologically relevant tasks, involving a behavioural paradigm of discrimination learning in semi-natural conditions and the usage of ecologically relevant stimuli, was executed. Three marmosets, 2 males and a female, behaved like human dichromats, showing an impaired performance when orange and green stimuli had to be discriminated. In contrast, 2 females resembled human trichromats, discriminating those kinds of pairs. Our data suggest that Callithrix penicillata presents a polymorphic trichromacy, with dichromatic males and dichromatic or trichromatic females.


Subject(s)
Callithrix/physiology , Color Perception/physiology , Discrimination Learning/physiology , Feeding Behavior/physiology , Animals , Brazil , Color , Female , Male
16.
Primates ; 44(4): 413-8, 2003 Oct.
Article in English | MEDLINE | ID: mdl-14593516

ABSTRACT

Colour is one cue that monkeys use for perceptual segregation of targets and to identify food resources. For fruit-eating primates such as Saguinus, an accurate colour perception would be advantageous to help find ripe fruits at distance. The colour vision abilities of black-handed tamarins ( Saguinus midas niger) were assessed through a discrimination learning paradigm using Munsell colour chips as stimuli. Pairs of chips were chosen from an early experiment with protan and deutan humans. The monkeys (three males and one female) were tested with stimuli of the same hue, but different brightness values, in order to make sure that discriminations were based on colour rather than brightness cues. The results showed that the female, but not the males, presented an above-chance performance for stimuli resembling hue conditions under which tamarins forage (oranges vs greens). Colour vision in S. m. niger is discussed according to the advantages and disadvantages of dichromatism in daily search for food as well as to aspects regarding polymorphism in New World monkeys.


Subject(s)
Color Perception/physiology , Discrimination Learning/physiology , Saguinus/psychology , Animals , Color Perception Tests , Female , Male , Saguinus/physiology
17.
Behav Brain Res ; 129(1-2): 153-7, 2002 Feb 01.
Article in English | MEDLINE | ID: mdl-11809506

ABSTRACT

In previous experiments based on color vision discrimination of Munsell chips, Pessoa et al. (Behav Brain Res 1997;89:285-8) presented evidence of trichromatic color vision in capuchin monkeys. However, the possibility of subjects using brightness cues was not eliminated. The purpose of the present study was to reassess the color perception in Cebus apella in a similar behavioral paradigm, but using a range of brightness values at each tested hue. We now report that male capuchins show a dichromatic behavior. The results are discussed in terms of the hypothesis of male dichromatism in the New World monkey, the biological role of color vision and cognitive abilities of capuchin monkeys.


Subject(s)
Color Perception/physiology , Adult , Animals , Cebus , Cues , Discrimination, Psychological/physiology , Female , Humans , Male
18.
J Periodontol ; 69(2): 209-18, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9526921

ABSTRACT

Localized juvenile periodontitis (LJP) is an early-onset periodontal disease associated with a polymorphonuclear neutrophil (PMN) defective migratory response. Kinetics of actin polymerization-depolymerization determine the shape changes occurring in the plasma membrane-associated cytoskeleton and provide the driving force for directed cell migration (chemotaxis). Therefore, we investigated the relation between an abnormality in LJP PMN chemotaxis and an altered reorganization of the actin filament network. PMNs isolated from peripheral blood of LJP patients (n=14) and matching control subjects (n=12) were evaluated for random and directed migration in a Boyden chamber assay, and the kinetics of actin polymerization were studied by flow cytometry. Three groups of LJP patients could be distinguished on the basis of their PMN-chemotactic response compared to their matched control: depressed (n=6), normal (n=4), and elevated (n=4). The abnormal (depressed or elevated) chemotaxis was generally not related to abnormal random migratory response, except for two patients. Since the kinetics of formyl-methionyl-leucyl-phenylalanine-induced F-actin response were highly variable from one subject to another, means were calculated at each timepoint with the values obtained from each group of subjects and compared by a general factorial design analysis. No statistically significant differences were detected between the control group and the LJP patient group. Furthermore, the data did not show a correlation between the kinetics of actin polymerization-depolymerization and the abnormal chemotactic response observed in LJP PMNs. Hence, the chemotaxis defect in LJP PMN appears to be mediated by signaling events that carry their effect independently of an intact cytoskeleton.


Subject(s)
Actins/ultrastructure , Aggressive Periodontitis/pathology , Cytoskeleton/ultrastructure , Neutrophils/ultrastructure , Actin Cytoskeleton/ultrastructure , Actins/metabolism , Adolescent , Case-Control Studies , Cell Membrane/ultrastructure , Cell Movement/drug effects , Cell Movement/physiology , Chemotaxis, Leukocyte/drug effects , Chemotaxis, Leukocyte/physiology , Factor Analysis, Statistical , Female , Flow Cytometry , Humans , Male , N-Formylmethionine Leucyl-Phenylalanine/pharmacology , Neutrophils/drug effects , Neutrophils/physiology , Polymers/metabolism , Signal Transduction/physiology , Time Factors
19.
J Periodontol ; 67(10 Suppl): 1070-5, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8910825

ABSTRACT

A review of phagocytic cells-polymorphonuclear leukocytes and monocytes-in the inflammatory process is presented. Examples of phagocyte defect-related pathology serve as a framework for understanding the role of these cells in periodontal infection. The role of alterations in neutrophil function in localized juvenile periodontitis is presented as a model system for understanding periodontal pathology as a result of host-related functional abnormalities. Two topical alternative hypotheses for periodontal breakdown are presented in which macrophage control of the chronic lesion is altered by an absence of T cells or the influence of bacterial superantigens.


Subject(s)
Bacterial Infections/immunology , Periodontal Diseases/microbiology , Phagocytes/physiology , Aggressive Periodontitis/immunology , Aggressive Periodontitis/microbiology , Antigens, Bacterial/immunology , Bacterial Infections/pathology , Humans , Macrophages/immunology , Macrophages/physiology , Monocytes/immunology , Monocytes/physiology , Neutrophils/immunology , Neutrophils/physiology , Periodontal Diseases/immunology , Periodontal Diseases/pathology , Phagocytes/immunology , Superantigens/immunology , T-Lymphocytes/immunology , T-Lymphocytes/physiology
20.
J Periodontol ; 64(7): 617-21, 1993 Jul.
Article in English | MEDLINE | ID: mdl-8396175

ABSTRACT

Localized juvenile periodontitis (ljp) is an early onset form of periodontal disease characterized by unique localization to first molars and incisors and a high prevalence of neutrophil abnormalities, particularly chemotaxis. The intracellular transduction mechanisms that follow receptor-ligand coupling on the neutrophil surface and lead to chemotaxis are not clearly established. Chemotaxis and phagocytosis are modulated by a variety of receptors and involve several activation pathways; the role of intracellular calcium as a presumptive second messenger and mediator of these events is well established. The putative effector mechanisms for the chemotactic receptor of neutrophils also include the possible activation of a phospholipase, protein kinase C, methyltransferase, or adenylate cyclase. In normal neutrophils, a phosphoinositide pathway initiated by phospholipase C, which results in the activation of protein kinase C via diacylglycerol and the generation of IP3, has been implicated. In order to better understand the stages of neutrophil transduction, fluorescent probes were used to monitor neutrophil calcium changes. Chlorotetracycline (CTC) was used as an indirect probe of intracellular membrane-bound pool of calcium stores, and Quin-2 was used to monitor cytosolic free calcium levels of FMLP stimulated normal and LJP neutrophils. The results indicate that the early phase of the calcium response affiliated with the release of intracellularly sequestered calcium appears intact in LJP neutrophils, as the CTC fluorescence changes were similar to control values. The second phase of the calcium response, associated with membrane channel activation and an influx of extracellular calcium, appeared compromised in the neutrophils of the LJP population.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Aggressive Periodontitis/physiopathology , Calcium Channels/physiology , Calcium/metabolism , Chemotaxis, Leukocyte , Neutrophils/metabolism , Adult , Aggressive Periodontitis/blood , Aggressive Periodontitis/metabolism , Aminoquinolines , Analysis of Variance , Calcium/analysis , Case-Control Studies , Child , Chlortetracycline , Cytosol/chemistry , Female , Humans , Male , Second Messenger Systems , Signal Transduction
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