Molecular Characterisation of Faecal Bacterial Assemblages Among Four Species of Syntopic Odonates.

Factors such as host species, phylogeny, diet, and both timing and location of sampling are thought to influence the composition of gut-associated bacteria in insects. In this study, we compared the faecal-associated bacterial taxa for three Coenagrion and one Enallagma damselfly species. We expected high overlap in representation of bacterial taxa due to the shared ecology and diet of these species. Using metabarcoding based on the 16S rRNA gene, we identified 1513 sequence variants, representing distinct bacterial 'taxa'. Intriguingly, the damselfly species showed somewhat different magnitudes of richness of ZOTUs, ranging from 480 to 914 ZOTUs. In total, 921 (or 60.8% of the 1513) distinct ZOTUs were non-shared, each found only in one species, and then most often in only a single individual. There was a surfeit of these non-shared incidental ZOTUs in the Enallagma species accounting for it showing the highest bacterial richness and accounting for a sample-wide pattern of more single-species ZOTUs than expected, based on comparisons to the null model. Future studies should address the extent to which faecal bacteria represent non-incidental gut bacteria and whether abundant and shared taxa are true gut symbionts. Pictures of odonates adopted from Norske Art databank under Creative Commons License (CC BY 4.0).

Mobile genes in the human microbiome are structured from global to individual scales.

Recent work has underscored the importance of the microbiome in human health, and has largely attributed differences in phenotype to differences in the species present among individuals. However, mobile genes can confer profoundly different phenotypes on different strains of the same species. Little is known about the function and distribution of mobile genes in the human microbiome, and in particular whether the gene pool is globally homogenous or constrained by human population structure. Here, we investigate this question by comparing the mobile genes found in the microbiomes of 81 metropolitan North Americans with those of 172 agrarian Fiji islanders using a combination of single-cell genomics and metagenomics. We find large differences in mobile gene content between the Fijian and North American microbiomes, with functional variation that mirrors known dietary differences such as the excess of plant-based starch degradation genes found in Fijian individuals. Notably, we also observed differences between the mobile gene pools of neighbouring Fijian villages, even though microbiome composition across villages is similar. Finally, we observe high rates of recombination leading to individual-specific mobile elements, suggesting that the abundance of some genes may reflect environmental selection rather than dispersal limitation. Together, these data support the hypothesis that human activities and behaviours provide selective pressures that shape mobile gene pools, and that acquisition of mobile genes is important for colonizing specific human populations.

Archaea are prominent members of the prokaryotic communities colonizing common forest mushrooms.

In this study, the abundance and composition of prokaryotic communities associated with the inner tissue of fruiting bodies of Suillus bovinus, Boletus pinophilus, Cantharellus cibarius, Agaricus arvensis, Lycoperdon perlatum, and Piptoporus betulinus were analyzed using culture-independent methods. Our findings indicate that archaea and bacteria colonize the internal tissues of all investigated specimens and that archaea are prominent members of the prokaryotic community. The ratio of archaeal 16S rRNA gene copy numbers to those of bacteria was >1 in the fruiting bodies of four out of six fungal species included in the study. The largest proportion of archaeal 16S rRNA gene sequences belonged to thaumarchaeotal classes Terrestrial group, Miscellaneous Crenarchaeotic Group (MCG), and Thermoplasmata. Bacterial communities showed characteristic compositions in each fungal species. Bacterial classes Gammaproteobacteria, Actinobacteria, Bacilli, and Clostridia were prominent among communities in fruiting body tissues. Bacterial populations in each fungal species had different characteristics. The results of this study imply that fruiting body tissues are an important habitat for abundant and diverse populations of archaea and bacteria.

Cold temperature decreases bacterial species richness in nitrogen-removing bioreactors treating inorganic mine waters.

Explosives used in mining, such as ammonium nitrate fuel oil (ANFO), can cause eutrophication of the surrounding environment by leakage of ammonium and nitrate from undetonated material that is not properly treated. Cold temperatures in mines affect nitrogen removal from water when such nutrients are treated with bioreactors in situ. In this study we identified bacteria in the bioreactors and studied the effect of temperature on the bacterial community. The bioreactors consisted of sequential nitrification and denitrification units running at either 5 or 10°C. One nitrification bioreactor running at 5°C was fed with salt spiked water. From the nitrification bioreactors, sequences from both ammonia- and nitrite-oxidizing bacteria were identified, but the species were distinct at different temperatures. The main nitrifiers in the lower temperature were closely related to the genera Nitrosospira and Candidatus Nitrotoga. 16S rRNA gene sequences closely related to halotolerant Nitrosomonas eutropha were found only from the salt spiked nitrification bioreactor. At 10°C the genera Nitrosomonas and Nitrospira were the abundant nitrifiers. The results showed that bacterial species richness estimates were low, <150 operational taxonomic units (OTUs), in all bioreactor clone libraries, when sequences were assigned to operational taxonomic units at an evolutionary distance of 0.03. The only exception was the nitrification bioreactor running at 10°C where species richness was higher, >300 OTUs. Species richness was lower in bioreactors running at 5°C compared to those operating at 10°C.

Expression of mRNAs coding for the alpha 1 chain of type XIII collagen in human fetal tissues: comparison with expression of mRNAs for collagen types I, II, and III.

This paper describes the topographic distribution of the multiple mRNAs coding for a novel human short-chain collagen, the alpha 1 chain of type XIII collagen. To identify the tissues and cells expressing these mRNAs, human fetal tissues of 15-19 gestational wk were studied by Northern and in situ hybridizations. The distribution pattern of the type XIII collagen mRNAs was compared with that of fibrillar collagen types I, II, and III using specific human cDNA probes for each collagen type. Northern hybridization showed the bone, cartilage, intestine, skin, and striated muscle to contain mRNAs for type XIII collagen. An intense in situ hybridization signal was obtained with the type XIII collagen cDNAs in the epidermis, hair follicles, and nail root cells of the skin, whereas the fibrillar collagen mRNAs were detected in the dermis. Cells in the intestinal mucosal layer also appeared to contain high levels of alpha 1(XIII) collagen mRNAs, but contained none of the fibrillar collagen mRNAs. In the bone and striated muscle, alpha 1(XIII) collagen mRNAs were detected in the mesenchymal cells forming the reticulin fibers of the bone marrow and endomycium. The hybridization signal obtained with the alpha 1(XIII) collagen cDNA probe in cartilaginous areas of the growth plates was similar, but less intense, to that obtained with the type II collagen probe. A clear hybridization signal was also detected at the (pre)articular surfaces and at the margins of the epiphyses, whereas it was weaker in the resting chondrocytes in the middle of the epiphyses. The brain, heart, kidney, liver, lung, placenta, spleen, testis, tendon, and thymus did not appear to contain alpha 1(XIII) collagen mRNAs.

Apo A-I inhibits foam cell formation in Apo E-deficient mice after monocyte adherence to endothelium.

We have previously shown that expression of the human apo A-I transgene on the apo E-deficient background increases HDL cholesterol and greatly diminishes fatty streak lesion formation. To examine the mechanism, prelesional events in atherosclerotic plaque development were examined in 6- to 8-week-old apo E-deficient and apo E-deficient/human apo A-I transgenic mice. A quantitative assessment of subendothelial lipid deposition by freeze-fracture and deep-etch electron microscopy indicated that elevated apo A-I did not affect the distribution or amount of aortic arch subendothelial lipid deposits. Immunohistochemical staining for VCAM-1 demonstrated similar expression on endothelial cells at prelesional aortic branch sites from both apo E-deficient and apo E-deficient/human apo A-I transgenic mice. Transmission electron microscopy revealed monocytes bound to the aortic arch in mice of both genotypes, and immunohistochemical staining demonstrated that the area occupied by bound mononuclear cells was unchanged. Serum paraoxonase and aryl esterase activity did not differ between apo E-deficient and apo E-deficient/human apo A-I transgenic mice. These data suggest that increases in apo A-I and HDL cholesterol inhibit foam cell formation in apo E-deficient/human apo A-I transgenic mice at a stage following lipid deposition, endothelial activation, and monocyte adherence, without increases in HDL-associated paraoxonase.

Natural decay process affects the abundance and community structure of Bacteria and Archaea in Picea abies logs.

Prokaryotes colonize decaying wood and contribute to the degradation process, but the dynamics of prokaryotic communities during wood decay is still poorly understood. We studied the abundance and community composition of Bacteria and Archaea inhabiting naturally decaying Picea abies logs and tested the hypothesis that the variations in archaeal and bacterial abundances and community composition are coupled with environmental parameters related to the decay process. The data set comprises >500 logs at different decay stages from five geographical locations in south and central Finland. The results show that Bacteria and Archaea are an integral and dynamic component of decaying wood biota. The abundances of bacterial and archaeal 16S rRNA genes increase as wood decay progresses. Changes in bacterial community composition are clearly linked to the loss of density of wood, while specific fungal-bacterial interactions may also affect the distribution of bacterial taxa in decaying wood. Thaumarchaeota were prominent members of the archaeal populations colonizing decaying wood, providing further evidence of the versatility and cosmopolitan nature of this phylum in the environment. The composition and dynamics of the prokaryotic community suggest that they are an active component of biota that are involved in processing substrates in decaying wood material.

Chlamydia pneumoniae does not increase atherosclerosis in the aortic root of apolipoprotein E-deficient mice.

In epidemiological studies, an association between cardiovascular disease and Chlamydia pneumoniae (C pneumoniae) infection has been observed. Although C pneumoniae has been shown to be present in atherosclerotic lesions, a causal relationship between C pneumoniae infection and atherosclerosis has not been demonstrated. To study this question, we used 2 strains of apolipoprotein (apo) E-deficient mice. Eight-week-old mice on an FVB background that were maintained on either a low- or a high-fat diet were infected 3 times at 1-week intervals with C pneumoniae, and atherosclerotic lesions were measured in the aortic root at 10 weeks after the primary infection. In each of the diet groups, no difference in the extent of atherosclerosis could be observed between the C pneumoniae-infected and control animals. In further studies, 2 strains of apoE-deficient mice (FVB or C57BL/6J background) were infected 4 times at 3- to 4-week intervals, and the extent of atherosclerosis was analyzed 18 weeks later. The mice were kept on either a low- or a high-fat diet. The high-fat diet increased atherosclerosis, and a difference in atherosclerosis susceptibility between the mouse strains was observed. However, C pneumoniae infection did not influence lesion size in either mouse strain. On the other hand, C pneumoniae could not be demonstrated by polymerase chain reaction in any of the atherosclerotic lesions of the infected animals studied. A small decrease in serum cholesterol and triglyceride levels 3 days after the primary infection occurred, but after that no differences in serum lipid levels compared with those in noninfected animals were evident. In the myocardium of C pneumoniae-infected mice, no inflammatory signs could be observed. We conclude that under the experimental conditions used, C pneumoniae infection does not accelerate atherogenic changes in the aortic root of apoE-deficient mice.

A polymorphic site in the 3' untranslated region of the cholesteryl ester transfer protein (CETP) gene is associated with low CETP activity.

The exon 16 of the cholesteryl ester transfer protein (CETP) gene was screened for possible mutations in patients with low plasma high-density lipoprotein cholesterol (HDL-C) levels and established coronary heart disease. 115 men who had undergone coronary bypass surgery were compared with a random population sample of 515 subjects. A single G to A substitution at base pair 1696 was found in the 3' untranslated region of the CETP gene. Among the patients with low HDL-C, the plasma CETP activity was 29% lower (P = 0.002) in the subjects homozygous for the mutation than in those with other genotypes. The same effect was observed in the random population sample (P = 0.02). The mutation did not affect the plasma lipid or lipoprotein values, although the mean HDL-C tended to be slightly higher and the ratio of cholesterol content in the apo B-containing lipoproteins to HDL-C slightly lower in the homozygotes compared with the other genotypes. In conclusion, we describe a prevalent mutation at the CETP gene locus associated with low plasma CETP activity. Our results support previous findings suggesting that the genes in chromosome 16 may be important in the regulation of reverse cholesterol transport and in protection against coronary heart disease.

R451Q mutation in the cholesteryl ester transfer protein (CETP) gene is associated with high plasma CETP activity.

Cholesteryl ester transfer protein (CETP), as a candidate gene for dyslipoproteinemia and coronary heart disease, was studied in 105 men with low plasma concentrations of high density lipoprotein cholesterol (HDL-C) and established coronary heart disease as well as in 515 randomly selected men and women. A one-nucleotide substitution (G to A) in exon 15, which changes arginine (451) to glutamine in CETP protein, was detected by PCR-SSCP and direct sequencing and screened in the population sample by a simple PCR-based restriction assay. In the random population sample the allele frequency of the R451Q mutation was 1.9%. Men heterozygous for the R451Q mutation (n = 7) had 27% higher CETP activity than age-, body mass index-, smoking- and alcohol consumption-matched controls with normal genotype (n = 21; P = 0.003). Women heterozygous for the R451Q mutation (n = 7) had 16% lower total cholesterol compared to matched controls (n = 21; P = 0.07), but no such difference was detected in men. In the random population sample the correlation between plasma total cholesterol level and CETP activity was 0.19 (P = 0.044), both in men and women. When women with total cholesterol over 5.2 mmol/l were excluded from analysis, heterozygotes (n = 4) had plasma CETP activity of 113 nmol/h/ml plasma, whereas those of normal genotype (n = 12) had 103 nmol/h/ml plasma, but this difference was not statistically significant. Women heterozygous for the R451Q mutation and consuming less than 10 g alcohol a week had 23% lower HDL-C compared to women with the normal genotype (P = 0.032). In conclusion, we describe a mutation in the CETP gene associated with high plasma CETP activity in men and with low total cholesterol in women. Further studies are needed to evaluate the effect of mutation on the risk of coronary heart disease.

Effect of extreme fish consumption on dietary and plasma antioxidant levels and fatty acid composition.

OBJECTIVE: To assess the effects of high-fish and low-fish diets on plasma concentrations of fatty acids and selected antioxidants. DESIGN AND SUBJECTS: The effects of fish consumption on dietary and plasma antioxidant levels and fatty acid composition were studied as part of a large dietary survey of Finnish adults (n = 1861). High-fish consumers were matched with low-fish consumers and 41 pairs were identified. The members of each pair were of the same sex, from the same 10 y age group, and from the same or adjacent areas. There were 21 men and 20 women in each group, with a mean age of 54.3 y. METHODS: The fish consumption of the subjects was investigated with a qualitative food questionnaire. Additionally, a 3 d food record was used to estimate the diet. Two indices were defined to describe the oxidation potential of the diets. The plasma alpha-tocopherol, gamma-tocopherol, and beta-carotene concentrations and various fatty acids were analysed. RESULTS: The mean fish intake was 103 g/d in the high-fish and 5 g/d in the low-fish group. The dietary intakes of vitamin C, protein, total n-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid, docosahexaenoic acid, mercury, selenium, and salt and the theoretical oxidative potential were higher (P < 0.05) and the saturated fatty acid intake lower (P < 0.01) in the high-fish than in the low-fish group. The dietary vitamin E intake was similar in both groups but the ratio of dietary vitamin E/PUFA was higher (P < 0.01) in the high-fish than in the low-fish group (0.85 and 0.75, respectively). The plasma n-3 PUFAs were higher (P < 0.001) and n-6 PUFAs lower (P < 0.001) in the high-fish than in the low-fish group. There were no differences in plasma antioxidant levels between the groups. CONCLUSION: This study shows that extreme fish consumption does not affect plasma antioxidant levels.

Computing geometric properties of images represented by linear quadtrees.

The region quadtree is a hierarchical data structure that finds use in applications such as image processing, computer graphics, pattern recognition, robotics, and cartography. In order to save space, a number of pointerless quadtree representations (termed linear quadtrees) have been proposed. One representation maintains the nodes in a list ordered according to a preorder traversal of the quadtree. Using such an image representation and a graph definition of a quadtree, a general algorithm to compute geometric image properties such as the perimeter, the Euler number, and the connected components of an image is developed and analyzed. The algorithm differs from the conventional approaches to images represented by quadtrees in that it does not make use of neighbor finding methods that require the location of a nearest common ancestor. Instead, it makes use of a staircase-like data structure to represent the blocks that have been already processed. The worst-case execution time of the algorithm, when used to compute the perimeter, is proportional to the number of leaf nodes in the quadtree, which is optimal. For an image of size 2n × 2n, the perimeter algorithm requires only four arrays of 2n positions each for working storage. This makes it well suited to processing linear quadtrees residing in secondary storage. Implementation experience has confirmed its superiority to existing approaches to computing geometric properties for images represented by quadtrees.

The alpha 1 chain of type XIII collagen consists of three collagenous and four noncollagenous domains, and its primary transcript undergoes complex alternative splicing.

We have recently reported a characterization of cDNA clones that encode an apparently novel human collagen that undergoes alternative splicing. These cDNAs covered one-third of the corresponding 2.5-2.8-kilobase mRNAs. We have now determined the complete primary structure of the protein encoded by several overlapping cDNAs isolated from a human endothelial cell library. Since the deduced translation product of the cDNAs is different in structure from all other collagen types, we have given the collagen chain encoded by the cDNAs the designation alpha 1 (XIII). The deduced polypeptide consists of three collagenous domains and four noncollagenous domains, two of them separating the collagenous domains and two located at the N-terminal and C-terminal ends of the polypeptide. Cysteine residues are found in three of the noncollagenous domains and also in the extreme N-terminal collagenous domain. Surprisingly, comparison of the nucleotide sequences encoded by the overlapping cDNA clones demonstrates that there are several alpha 1 (XIII) collagen mRNAs in HT-1080 human fibrosarcoma cells and human endothelial cells which differ in coding potential. Nuclease S1 mapping experiments suggest that these different mRNAs arise through alternative splicing of the precursor RNA at five locations within the coding region. This property makes type XIII collagen unique among all the collagen types studied so far. Its polypeptide length, therefore, may vary between 614 and 526 amino acids, depending on what internal splicing has taken place.

Comparison of in vivo effects of nitroglycerin and insulin on the aortic pressure waveform.

BACKGROUND: Individuals whose platelets are resistant to the antiaggregatory effects of insulin in vitro are also resistant to the antiaggregatory effects of nitroglycerin (GTN). We have previously shown that insulin acutely diminishes central wave reflection in large arteries and that this action of insulin is blunted in insulin-resistant subjects. However, as yet, no studies have compared the haemodynamic effects of insulin and GTN on large arterial function in the same group of subjects. The aim of this study was to determine whether resistance to the haemodynamic effects of insulin is a defect specific to insulin or whether individuals resistant to the vascular actions of insulin are also resistant to GTN. DESIGN AND RESULTS: Dose-response characteristics of insulin and GTN on the aortic waveform were determined using applanation tonometry and pulse wave analysis (PWA) in seven healthy men (age 26 +/- 1 year, BMI 25 +/- 2 kg m(-2)). Three doses of sublingual GTN (500 microg for 1, 3 or 5 min) and insulin (0.5, 1 or 2 mU kg(-1) min(-1) for 120 min) were administered on three separate occasions. Both agents dose-dependently decreased central pulse pressure and the augmentation index (AIx) without changing brachial artery blood pressure. We next compared responses to insulin (2 mU kg(-1) min(-1) for 120 min) and sublingual GTN (500 microg for 5 min) in 20 nondiabetic subjects (age 50 +/- 2 year, BMI 21.0-36.3 kg m(-2)). Again, both agents significantly decreased AIx. Although the vascular effects of insulin and GTN vascular were positively correlated [Spearman's r=0.92 (95% confidence interval 0.81-0.97), P<0.0001], the time-course for the action GTN was faster than that of insulin. Brachial systolic blood pressure remained unchanged during the insulin infusion (122 +/- 3 vs. 121 +/- 3 mmHg, 0 vs. 120 min) but aortic systolic blood pressure decreased significantly by 30 min (111 +/- 3 vs. 107 +/- 3 mmHg, 0 vs. 30 min, P<0.01). Similarly, GTN decreased aortic systolic blood pressure from 119 +/- 4 to maximally 112 +/- 3 mmHg (P<0.001) without significantly decreasing systolic blood pressure in the brachial artery. CONCLUSIONS: The effects of insulin and GTN on large arterial haemodynamics are dose-dependent and significantly correlated. The exact mechanisms and sites of action of insulin and GTN in subjects with insulin resistance remain to be established.

Assignment of the gene coding for the alpha 1 chain of collagen type XIII (COL13A1) to human chromosome region 10q11----qter.

The gene coding for the alpha 1 chain of human type XIII collagen. COL13A1, is assigned to chromosome region 10q11----qter by Southern blot hybridization of DNA from 24 human x rodent somatic cell hybrids using a cloned cDNA as probe. A number of previous reports indicate that 10 of the collagen genes are located on six autosomes, but no other collagen genes have been found on chromosome 10. The data therefore provide further evidence for the dispersion of members of the collagen gene family throughout the genome.

Recombinant Lactococcus starters as a potential source of additional peptidolytic activity in cheese ripening.

AIMS: The aim of this study was to modulate the lactococcal proteolytic system for enhancement of the cheese ripening process. METHODS AND RESULTS: The genes encoding PepN, PepC, PepX and PepI peptidases of a highly proteolytic Lactobacillus helveticus strain were transferred into Lactococcus lactis in a food-grade cloning system. A comparison of the relative peptidase activities from the transformants with those from the untransformed host, determined in the conditions of maturing cheese, showed that an increase in peptidase activity could be achieved by introducing a selected peptidase gene from Lact. helveticus into L. lactis. CONCLUSIONS: Recombinant L. lactis starter strains, carrying a peptidase gene from Lact. helveticus, may have an important contribution to the proteolysis of maturing cheese by producing an additional peptidolytic enzyme activity. SIGNIFICANCE AND IMPACT OF THE STUDY: The results will be of importance in shortening the ripening period and production of special cheeses (e.g. reduced-fat cheeses) with improved characteristics.

A three-year follow-up study of patients in a day treatment program.

A 3-year follow-up study was conducted with 73 psychiatric patients in a Finnish day treatment program. The treatment outcome for these patients, who carried a wide range of diagnoses, was measured using psychiatric rehospitalization as a criterion. There were a large number of patients who were disabled and had been receiving social security benefits during the 3 years following discharge from the day treatment program. The rehospitalized cases involved mainly patients with a diagnosis of schizophrenia or personality disorder; use of neuroleptic medication was significantly associated with poor results. The numbers of psychiatric hospitalizations before treatment in the day treatment program in 1985 was found to be independent of hospitalizations during follow-up years. The results of the study support the claim that day treatment does not increase the likelihood of rehospitalization. Day treatment may reduce the length of stay during rehospitalization, but it is also clear that it cannot stop the rehospitalization of patients with severe diagnoses.

Insulin therapy improves insulin actions on glucose metabolism and aortic wave reflection in type 2 diabetic patients.

BACKGROUND: Normal insulin action in vivo involves a decrease in aortic systolic blood pressure as a result of an insulin-induced decrease in the amplitude of the second systolic (reflected) pressure wave. This action of insulin and insulin action on glucose metabolism is impaired in insulin-resistant and type 2 diabetic subjects. We determined whether 6 months of insulin therapy affects insulin actions on glucose metabolism and vascular function. MATERIALS AND METHODS: Thirteen type 2 diabetic patients (age 53 +/- 2 years, body mass index 30.8 +/- 1.2 kg m(-2), HbA1C 8.8 +/- 0.2%) were studied before and after insulin therapy. Central aortic pressure waveforms were reconstructed from those recorded in the periphery using applanation tonometry every 30 min. This allowed determination of augmentation, i.e. the pressure difference between the second and first systolic pressure peaks and the augmentation index (AgI, augmentation divided by pulse pressure). The measurements were performed basally and during euglycaemic hyperinsulinaemic conditions. RESULTS: Insulin therapy increased whole body glucose disposal by 35% from 5.1 +/- 0.7 to 6.8 +/- 0.6 mg kg ffm(-1) min(-1) (P<0.001 for 0 vs. 60 months). 6 months of insulin therapy decreased basal AgI from 26.2 +/- 1.8 to 22.7 +/- 2.3% (P<0.05). The change in AgI by insulin infusion was similar before and after insulin therapy at all time points. Peripheral blood flow, heart rate and blood pressures remained unchanged. CONCLUSIONS: Insulin therapy improves insulin action on glucose metabolism and decreases basal AgI. These data support the idea that insulin therapy has beneficial effects on vascular function.