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PubMed2005

Quantifying calculus: a suggested new approach for recording an important indicator of diet and dental health.

This paper describes a quantitative approach to the assessment of dental calculus in human archaeological skeletal samples. The approach combines the ranked calculus scoring method described by Buikstra and Ubelaker [1994. Arkansas Archeological Survey Research Series, Arkansas Archeological Survey, Fayetteville, Arkansas] and a modified Simplified Calculus Index, utilized by dental clinicians. We recorded amounts of calculus on the buccal, lingual, and interproximal surface of all extant teeth, and generated an index for the maxillary posterior dentition, maxillary anterior dentition, mandibular posterior dentition, and mandibular anterior dentition for three skeletal samples. They include 145 Egyptian Predynastic individuals from the site of Hierakonpolis, 104 Predynastic individuals from Naqada, Egypt, and 101 Meroitic Nubians from Semna South, present-day Sudan. Mann-Whitney U tests were used to analyze differences between the sexes and among age groups at each site. The results demonstrate that the calculus indices more effectively reveal trends and differences in calculus severity than frequency data can alone. For example, at Hierakonpolis, males (18-35 years) had significantly more calculus in the maxillary posterior dentition than females, while females (50+ years) had significantly more calculus in the maxillary posterior teeth. Frequency data merely showed that 94% of both males and females had calculus. The use of calculus indices can reveal how quickly calculus accumulates with age within the dental arcade and within a sample. Moreover, better understanding of the severity and location of calculus can improve a researcher's knowledge regarding the effect of calculus on dental pathologies, such as carious lesions and periodontal disease.

Age Factors↗

PubMedDate not supplied

The extracellular matrix and its modulation in the trabecular meshwork.

The extracellular matrix (ECM) in the trabecular meshwork is is believed to be essential for maintenance of the normal outflow system. Excessive, abnormal accumulations of ECM materials have been noted in the trabecular meshwork of eyes obtained from patients with primary open angle glaucoma. This review summarizes the current knowledge regarding the composition of this matrix and the receptors for ECM proteins in the trabecular meshwork. Modulations of the ECM elements by constituents in the aqueous humor after phagocytic challenges and by glucocorticoids are also described. The ECM is known to regulate cell differentiation and cell behavior in a number of systems. It will thus be of particular interest to establish the relationship between the modulated ECM and the functional status of trabecular meshwork cells and to examine the possible relevance of such modulation to outflow resistance.

Animals↗

PubMed2002

Comparative analysis of protein synthesis, transcription and cytoplasmic polyadenylation of mRNA during maturation of bovine oocytes in vitro.

In many species, large numbers of macromolecules are accumulated during oocyte growth. The messenger and ribosomal RNAs produced in these cells are far in excess of those necessary to support protein synthesis. Thus, the aim of this study was to elucidate the processes of translational regulation during meiotic maturation. The relationship between transcription, translation and polyadenylation of mRNA during in-vitro maturation (IVM) of bovine oocytes was investigated. The results presented here show that overall protein synthesis is stimulated during meiotic maturation (approximately three times) concomitantly with the onset of germinal vesicle breakdown after 6 to 10 h of IVM. However, in metaphase II, the incorporation of [35S]methionine into proteins showed only basal levels, as in the germinal vesicle (GV) stage. Furthermore, in the course of IVM, de-novo transcription strongly declines as determined by measuring the incorporation of [3H]uridine into RNA. In contrast to this finding, the incorporation of [3H]adenosine increased and showed a peak during the time interval from 6 to 10 h of IVM, parallel with the onset of germinal vesicle breakdown (GVBD) and translation. In the further course of maturation, only a moderate decrease of [3H]adenosine incorporation was observed. These results indicate that (i) translation increased at the time of GVBD; (ii) these processes were accompanied by polyadenylation of mRNA; and (iii) although transcription declines, polyadenylated mRNA is accumulated until metaphase II (as shown by poly(U)-hybridization), in which protein synthesis is low. The correlation of these processes is discussed here. A detailed knowledge of the biochemical and molecular processes which occur during oocyte maturation can be useful for the improvement of IVM conditions.

Adenosine↗

PubMed1999

Adult soft tissue sarcoma.

BACKGROUND: Soft tissue sarcomas (STS) are a group of anatomically and histologically diverse tumours. They account for about 1% of adult malignancies, and about 50% of patients diagnosed with sarcoma eventually die of the disease. These tumours are grouped together because of shared biological characteristics and treatment responses. METHODS: A review of the key literature on STS was undertaken, complemented by data taken from the prospectively accumulated database of 3442 patients treated for STS at Memorial Sloan-Kettering Cancer Center (MSKCC) from July 1982 to December 1997. RESULTS: Despite advances in knowledge of the molecular genetics of STS, the aetiology in most cases remains elusive. Management has been gradually refined over the last two decades. Core biopsy usually provides enough material for diagnosis. Computed tomography and magnetic resonance imaging provide a similar amount of information, which is usually adequate for surgical planning. Amputation as standard treatment for extremity lesions has been replaced by limb-sparing surgery in about 90% of patients. The role of adjuvant radiation has been further defined: it has been shown to be unnecessary for completely excised tumours less than 5 cm in diameter, but effective in decreasing local recurrence for others. Adjuvant chemotherapy has been controversial for many years. Recent meta-analysis of randomized trial results has found a small reduction in local and distant relapse, and a trend to better overall survival. Recurrent or metastatic disease should be completely excised if possible. CONCLUSIONS: Soft tissue sarcoma requires multidisciplinary care tailored to the individual patient and tumour for optimal results.

Adult↗

PubMed1995

Epidemiology of fibrinogen.

As evidence accumulates to implicate fibrinogen as a risk factor for cardiovascular disease (CVD) it becomes important to characterize the levels and correlates of fibrinogen in diverse populations. Knowledge of the correlates of fibrinogen may help researchers to disentangle the independent contribution of elevated fibrinogen concentrations to CVD. Characterization of the normal range and possible determinants of fibrinogen concentrations, likewise, may aid CVD risk assessment and intervention research. Fibrinogen concentrations vary widely among populations and increase with age. Levels are consistently higher in women than men and rise after menopause. Smoking is the most important lifestyle correlate of fibrinogen. People with diabetes and hypertension have elevated fibrinogen levels, as do sedentary and obese individuals. Alcohol intake and oestrogen replacement therapy are associated with lower fibrinogen levels. Most other CVD risk factors are correlated positively with fibrinogen. Fibrinogen is clearly a marker of CVD risk. Yet, the strikingly non-specific pattern of higher fibrinogen with every CVD risk factor suggests that proving an independent causal role of fibrinogen will remain elusive in the absence of trials selectively lowering fibrinogen with the aim of reducing CVD.

Adult↗

PubMed2001

Musical sound processing in the human brain. Evidence from electric and magnetic recordings.

Recently, our knowledge regarding the brain's ability to represent invariant features of musical information even during the performance of a simultaneous task (unrelated to the sounds) has accumulated rapidly. Recordings of the change-specific mismatch negativity component of event-related brain potentials have shown that temporally and spectrally complex sounds as well as their relations are automatically processed by human auditory cortex. Furthermore, recent magnetoencephalographic and positron emission topographic investigations indicate that this processing differs between phonetic and musical sounds within and between the cerebral hemispheres. These data thus suggest that despite the focus of listeners' conscious attention, relatively complex sound phenomena can be encoded by neural mechanisms that are specialized for musical sounds.

Auditory Perception↗

PubMed1984

Hepatic bile flow.

The hepatocyte is a polar cell that can remove a variety of molecules from blood and excrete them into bile. This review is primarily concerned with the mechanism of transport of the principal anions--the bile salts--across the sinusoidal membrane, their passage through the cell, and excretion across the canalicular membrane. Clearly much of this process is poorly understood, but the study of the membrane stages should be facilitated by the ability to prepare purified sinusoidal and canalicular membrane vesicles. For example, the relative importance of albumin-binding sites as well as the putative bile salt receptor proteins can be better assessed. It seems likely that although the interaction of bile salts with receptor proteins is important, it is an initial event that puts the bile salt in the correct place for uptake to occur. The driving force for uptake is the Na+ gradient created across the basolateral membrane by the activity of the Na+-K+-ATPase. Within the cell, various modes of transport have been suggested. Several authors emphasize the importance of protein binding of bile salts, either because of their presumed ability to maintain the concentration of these anions in the hepatocyte below their critical micellar concentration or because of their putative role in transport. It is important to understand these aspects of the role of cytosolic proteins for several reasons. Knowledge of the true concentration of free bile salt within the cell should allow estimation of whether the electrochemical gradient is sufficient for bile salts to accumulate in bile without the need for active transport of molecules from the cell into the canaliculus. The compartmental model described by Strange et al. (153) offers one theoretical way of determining the concentration of free bile salt, although the problems inherent in studying amphipath binding to the membranes of subcellular organelles (31) require that the model be reevaluated by the hygroscopic-desorption method. The second role suggested for the cytosolic bile salt-binding proteins is as transport proteins. As discussed in section VI, I think it is unlikely that the proteins identified so far act in this way, and it is more likely that movement occurs by diffusion in free solution. It is also important to determine the possible involvement of subcellular organelles such as Golgi bodies. Little is known of their role in the transport of bile salts or indeed where bile salt micelles are formed.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1996

Molecular determinants of acute inflammatory responses to biomaterials.

The frequent inflammatory responses to implanted medical devices are puzzling in view of the inert and nontoxic nature of most biomaterials. Because implant surfaces spontaneously adsorb host proteins, this proteinaceous film is probably important in the subsequent attraction of phagocytes. In fact, earlier we found that acute inflammatory responses to experimental polyethylene terephthalate implants in mice require the precedent adsorption of one particular host protein, fibrinogen. The present investigations were aimed at defining the molecular determinants of fibrinogen-mediated acute inflammatory responses to implanted biomaterials. We find: (a) plasmin degradation of purified fibrinogen into defined domains reveals that the proinflammatory activity resides within the D fragment, which contains neither the fibrin cross-linking sites nor RGD sequences; (b) the major (and, perhaps, exclusive) proinflammatory sequence appears to be fibrinogen gamma 190-202, previously shown to interact with CD11b/CD18 (Mac-1). The chemically synthesized peptide, cross-linked to albumin (which itself does not promote inflammatory responses), mimics the proinflammatory effect of adsorbed native fibrinogen; and (c) this sequence probably promotes inflammatory responses through interactions with Mac-1 because phagocyte accumulation on experimental implants is almost completely abrogated by administration of recombinant neutrophil inhibitory factor (which blocks CD11b-fibrin(ogen) interaction). We conclude that improved knowledge of such surface-protein-phagocyte interactions may permit the future development of more biocompatible implantable materials.

Acute Disease↗

PubMed2001

The neuropeptide pituitary adenylate cyclase-activating polypeptide and islet function.

The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is ubiquitously distributed in both the central and peripheral nervous systems and exerts a variety of effects. PACAP is a neuropeptide in pancreatic islets, where it has been suggested as a parasympathetic and sensory neurotransmitter. PACAP stimulates insulin secretion in a glucose-dependent manner, by an effect executed mainly through augmenting the formation of cAMP and stimulating the uptake of calcium. Accumulating evidence in animal studies points to a physiological importance of PACAP in the regulation of the insulin response to feeding. This review summarizes the current knowledge of islet actions and mechanisms and the function of PACAP.

Animals↗

PubMed2006

[Drug therapy in the elderly. What should we know?].

Because of the increasing longevity of the population, a growing number of very old people are exposed to medications. Drug therapy in this population is difficult because of our lack of knowledge. The number of drugs administered is generally high and the prescription is often inappropriate. Changes in body composition, malnutrition and renal failure can cause drug accumulation and toxicity. However, hepatic metabolism via cytochrome P450 does not seem to be markedly influenced by oldness. Iatrogenic pathology is frequent in the elderly and may lead to hospitalisation and reduction in quality of life. Specific education of the medical care team should be promoted in order to tackle this important problem of public health.

Aged↗

PubMed1990

[Health behavior and cardiovascular risk factors in females in relation to their marital status].

This is an overview of the literature analysing the international level of knowledge about the influence of marital status on the prevalence of cigarette smoking, hypertension, hyperlipoproteinemia, obesity, alcohol consumption and type-A-behavior of women. An accumulation of the more behavior-dependent risk factors cigarette smoking and alcohol consumption was found by divorced and of the obesity by never married women. Widowed women scarcely differ from women in other marital status groups in their risk factor profile. The risk factors hypertension and hyperlipoproteinemia hardly correlate with the marital status. The overcome-behavior by loading is discussed as one possible cause of the found correlations. That's why family and social support has got a preventive consequence.

Adult↗

PubMed1989

Mercury, cadmium and lead levels in marine organisms (Mytilus galloprovincialis Lmk.) collected along the Italian coasts.

The growing importance assumed in the last ten years by contamination of the marine environment caused by heavy metals has evidenced the necessity to constantly deepen the knowledge of pollutant concentration that can reach man through the food chain. Particularly interesting is the determination of potentially toxic elements in marine organisms which through accumulation and concentration processes can provide a direct correlation with the ecosystem's degree of contamination. The present study takes into account the determination of mercury, cadmium and lead in samples of Mytilus galloprovincialis Lmk. collected in 41 sites along the Italian coast, between August 1986-April 1987. Analyses were performed using both the electrothermal (cadmium and lead) and the cold vapour (mercury) atomic absorption spectrometry techniques. Results showed that, in general, the degree of contamination is low, with a few exceptions where the concentration values were greater than the mean values.

Animals↗

PubMed2005

Ecological and agricultural significance of bacterial polyhydroxyalkanoates.

Polyhydroxyalkanoates (PHAs) are a group of carbon andenergy storage compounds that are accumulated during suboptimal growth by many bacteria, and intracellularly deposited in the form of inclusion bodies. Accumulation of PHAs is thought to be used by bacteria to increase survival and stress tolerance in changing environments, and in competitive settings where carbon and energy sources may be limited, such as those encountered in the soil and the rhizosphere. Understanding the role that PHAs play as internal storage polymers is of fundamental importance in microbial ecology, and holds great potential for the improvement of bacterial inoculants for plants and soils. This review summarizes the current knowledge on the ecological function of PHAs, and their strategic role as survival factors in microorganisms under varying environmental stress is emphasized. It also explores the phylogeny of the PHA cycle enzymes, PHA synthase, and PHA depolymerase, suggesting that PHA accumulation was earlier acquired and maintained during evolution, thus contributing to microbial survival in the environment.

Acyltransferases↗

PubMed2006

Carotenoid accumulation and function in seeds and non-green tissues.

Carotenoids are plant pigments that function as antioxidants, hormone precursors, colourants and essential components of the photosynthetic apparatus. Carotenoids accumulate in nearly all types of plastids, not just the chloroplast, and are thus found in most plant organs and tissues, albeit at trace levels in some tissues. In this review we summarise the current knowledge of the carotenoid content of non-green plastids and discuss what is known about the regulation of their biosynthesis in roots, fruits, flowers, tubers and seeds. The emphasis is on food crops as carotenoids are essential components of human diets, primarily as some are precursors of vitamin A. The low carotenoid content of many staple foods, such as cereals, can exacerbate dietary deficiencies. The World Health Organisation has estimated that more than 100 million children are vitamin A-deficient and up to 500,000 of these children become blind each year. Many of these children die within 12 months of going blind. Thus, understanding the regulation of carotenoid accumulation in food crops, especially tubers and cereals, should facilitate improvements to nutritional value with potentially significant health benefits.

Arabidopsis Proteins↗

PubMedDate not supplied

Uremic toxicity: urea and beyond.

Successful replacement of renal function with dialysis supports the concept that uremia is a toxic state resulting from accumulated solutes and that toxicity results from high concentrations of these solutes in body fluids. Dialyzer clearance of urea, a surrogate toxin, is the currently accepted best measure of dialysis and dialysis adequacy, but it is admittedly a compromise due to current lack of knowledge about and inability to measure more toxic solutes. This failure could be explained if uremic toxicity is actually a summation effect of multiple toxins, each at individual subtoxic levels in the patient. Other solutes could be used as surrogates to measure clearance, but urea happens to be available in high concentrations, is easily measured by all clinical laboratories, and is easily dialyzed, so changes in concentration are sensitive indicators of clearance. Measurements of creatinine clearance are confounded by the disequilibrium that occurs across red cells within the dialyzer and in the patient. Other solutes probably behave more like creatinine than urea, so urea stands out as uniquely diffusible, a property that actually spoils its effectiveness as a surrogate toxin, especially when applied to more frequent and continuous dialysis. Accumulation of other solutes may correlate better with toxic uremic symptoms and the residual syndrome. More studies are needed to examine the kinetics of other solutes, their generation rates, and their distribution volumes to provide clinicians with more knowledge and tools to optimize dialysis treatments. Examination of the effectiveness of solute removal in patients dialyzed more frequently may provide significant insight into the pathogenesis of uremia.

Humans↗

PubMed2004

Influence of endostatin on embryonic vasculo- and angiogenesis.

The proteolytic fragment of collagen XVIII, endostatin, acts as an inhibitor of angiogenesis. To date, only limited knowledge exists on the effects of endostatin on endothelial cells during embryonic development. Therefore, we analysed the role of endostatin on embryonic vasculo- and angiogenesis. Endostatin is accumulated in embryonic tissue of mouse embryos. Similarly, in vessels of embryoid bodies (EBs), endostatin and its binding sites are distributed in vessels and sprouting areas. In EBs, endostatin increases endothelial cells (control, 279.3 +/- 76.5; 50 ng/ml, 566.3 +/- 90.1; 200 ng/ml, 594.5 +/- 166.3 tube-like structures per EB) and endothelial tubes by proliferation (control, 21.4 +/- 7.5; 50 ng/ml, 160.2 +/- 9.9; 200 ng/ml, 184.2 +/- 16.5 Ki67-positive nuclei per 50 tube-like structures); it also enhances migration (control, 380.5 +/- 159.8 cells; 50 ng/ml, 718.3 +/- 251 cells; 200 ng/ml, 706 +/- 89.4 cells) and apoptosis (control, 16.8 +/- 6.7; 50 ng/ml, 94.4 +/- 23.6; 200 ng/ml, 106 +/- 42 PARP-positive nuclei per 50 tube-like structures). Furthermore, endostatin modulates the morphology of the endothelial tubes by inducing contraction. Endostatin modulates the embryonic vascular development by enhancing proliferation, migration, and apoptosis as well as by regulating morphogenesis.

Animals↗

PubMed2006

Arabidopsis-rice-wheat gene orthologues for Na+ transport and transcript analysis in wheat-L. elongatum aneuploids under salt stress.

Lophopyrum elongatum is a wild relative of wheat that provides a source of novel genes for improvement of the salt tolerance of bread wheat. Improved Na(+) 'exclusion' is associated with salt tolerance in a wheat-L. elongatum amphiploid, in which a large proportion (ca. 50%) of the improved regulation of leaf Na(+) concentrations is controlled by chromosome 3E. In this study, genes that might control Na(+) accumulation, such as for transporters responsible for Na(+) entry (HKT1) and exit (SOS1) from cells, or compartmentalisation within vacuoles (NHX1, NHX5, AVP1, AVP2) in the model plant, Arabidopsis thaliana, were targeted for comparative analyses in wheat. Putative rice orthologues were identified and characterised as a means to bridge the large evolutionary distance between genomes from the model dicot and the more complex grass species. Wheat orthologues were identified through BLAST searching to identify either FL-cDNAs or ESTs and were subsequently used to design primers to amplify genomic DNA. The probable orthologous status of the wheat genes was confirmed through demonstration of similar intron-exon structure with their counterparts in Arabidopsis and rice. The majority of exons for Arabidopsis, rice and wheat orthologues of NHX1, NHX5 and SOS1 were conserved except for those at the amino and carboxy terminal ends. However, additional exons were identified in the predicted NHX1 and SOS1 genes of rice and wheat, as compared with Arabidopsis, indicating gene rearrangement events during evolution from a common ancestor. Nullisomic-tetrasomic, deletion and addition lines in wheat were used to assign gene sequences to chromosome regions in wheat and L. elongatum. Most sequences were assigned to homoeologous chromosomes, however, in some instances, such as for SOS1, genes were mapped to other unpredicted locations. Differential transcript abundance under salt stress indicated a complex pattern of expression for wheat orthologues that may regulate Na(+) accumulation in wheat lines containing chromosomes from L. elongatum. The identification of wheat orthologues to well characterized Arabidopsis genes, map locations and gene expression profiles increases our knowledge on the complex mechanisms regulating Na(+) transport in wheat and wheat-L. elongatum lines under salt stress.

Acclimatization↗

PubMed1998

Biosynthesis of D-aspartate in mammalian cells.

In this communication, we demonstrate that D-aspartate (D-Asp) is synthesized in pheochromocytoma cells (PC12). To our knowledge this is the first report of biosynthesis of D-Asp in mammalian cells. Synthesis of D-Asp was demonstrated by its time-dependent accumulation in the cell culture, and by the fact that this accumulation was proportional to the number of inoculated cells. D-Asp in PC12 cells was identified by (i) co-elution with authentic D-Asp on two different HPLC columns, an octadesyl silica column and a Pirkle-type chiral column, (ii) reversed elution order of D-Asp and L-Asp on another Pirkle-type chiral column with an opposite configuration, and (iii) sensitivity to D-Asp oxidase. In the cells the amount of D-Asp was approx. 12-14% of total Asp and no other investigated D-amino acid was detected. The amount of D-Asp did not increase during the culture of mouse 3T3 fibroblasts and human neuroblastoma NB-1 cells. Immunocytochemical staining with anti-D-Asp antiserum demonstrated that D-Asp synthesized is present in the cytoplasm of the cells.

3T3 Cells↗