Numerical analysis and comparison of flow fields in normal larynx and larynx with unilateral vocal fold paralysis

In this study, laryngeal flow fields are investigated and compared in normal larynx and models of larynx with unilateral vocal fold paralysis (UVFP). In paralytic models, three fixed initial glottal gaps are considered to understand the positive or probable negative impacts of surgical operation on unilaterally paralytic larynx, by which the paralyzed vocal fold is brought closer to the mid-plane. Various features of the flow fields have been discussed in detail including glottal gap width, glottal flow rate, glottal exit pressure pattern and glottal jet evolution. The numerical solution of fluid-structure interaction is carried out using ANSYS, and the results confirm some of the favorable effects of surgery on the patient’s larynx. It is also shown that by tightening the glottal gap, some of the problems caused by the presence of a motionless vocal fold, such as leakage through glottal gap in the closure phase resulting in breathy voice can be moderated, although some of the symptoms of this disorder remain relatively unchanged.     

Studies on some trace and minor elements in blood

Blood is one of the widely used specimens for biological trace element research because of its biological significance and ease of sampling. We have conducted a study of the blood of the Kalpakkam township population for trace and minor elements. For this purpose, analytical methods have been developed and standardized in our laboratory for the elemental analysis of blood plasma and red cells. Inductively coupled plasma-mass spectrometry (ICP-MS), a relatively new technique, has been applied for the analysis of trace elements. Details regarding spectral interference and matrix interference encountered in the analysis of blood and the methods of correcting them have been discussed. Flame atomic absorption spectrometry (AAS)/atomic emission spectrometry (AES) has been applied for the determination of minor elements. Precision and accuracy of these methods have also been discussed.     

Concentrations of major elements and mercury in unstimulated human saliva

The aim of this study was a preliminary assessment of a possible role of human saliva in the diagnosis of some physiological and pathological changes in oral and body functions. Reliable procedures for collection and analysis of samples were established in order to assess total concentrations of Ca, K, Mg, Na, P, and Hg in whole unstimulated saliva. Possible relationships between element concentrations and sex, age, smoking, illness conditions, or side effects resulting from the use of drugs were investigated. The effects of stimulated or unstimulated collection procedures, dental prosthesis, and amalgam fillings were also evaluated. Total concentrations of major cations and Hg in whole saliva from 33 healthy adults living in the Siena district showed a coefficient of variation ranging from 11% (P) to 53% (Na) and average values were in the same range of those previously reported for unstimulated saliva. Healthy males had significantly higher concentrations of K, Na, P, and Na/K, Na/Ca, Na/Mg, and Na/P values than females. Age, smoking, dental prosthesis, and amalgam fillings had no significant effects on the concentrations of major elements. On the contrary, concentrations of Hg were positively correlated to the number of amalgam fillings and increased at a rate of about 1.9 μg/L for each filling. No correlations were found between Hg concentrations and those of major elements. Comparisons with literature data showed a different composition (particularly for Na and Hg concentrations) between unstimulated and stimulated saliva. Samples from patients affected by idiopathic pulmonary fibrosis had significantly higher concentrations of K and the maximum value was measured in a patient affected by acute pulmonary edema. This increase was likely the result of pharmacological treatments with tricyclic antidepressants and/or saline solutions. Data reported in this study, although preliminary, contribute to the assessment of levels of major cations (some of them very little investigated) and Hg in whole unstimulated human saliva and provides consistent support for further research on the possible use of this easy accessible matrix as a diagnostic tool of body function changes.     

The cytotoxic interaction of inorganic trace elements with EDTA and cisplatin in sensitive and resistant human ovarian cancer cells

Summary Cisplatin (CDDP)-sensitive and -resistant human ovarian cells were studied in vitro with the objective of enhancing CDDP cytotoxicity by the addition of a metal and the chelate ethylenediaminetetraacetic acid (EDTA), to the CDDP. Chelateable elements, such as bismuth, calcium, cadmium, copper, iron, magnesium, selenium, vanadium, and zinc, when added to CDDP and in the presence of EDTA increased the cytotoxicity of the CDDP as compared to CDDP treatment alone.     

青藏高原湿地植物轻金属元素含量特征及其与环境因素的关系研究

以青藏高原湿地植物为研究对象,通过对青藏高原35个采样点的野外调查采样,对青藏高原湿地植物8种轻金属元素(Al、Mg、Ca、Sr、Ba、K、Na、Li)含量的特征及其与环境因素的关系进行分析。结果显示,不同湿地植物对不同轻金属元素的富集能力存在差异。轻金属元素在湿地植物体内的平均含量依次排序为:Li相似文献   

A genetic view of laryngeal cancer heterogeneity

During the recent decades significant improvements in the understanding of laryngeal molecular biology allowed a better characterization of the tumor. However, despite increased molecular knowledge and clinical efforts, survival of patients with laryngeal cancer remains the same as 30 years ago. Although this result may not make major conclusions as preservation approaches were not broadly used until the time of database collection, it seems to be clear that there is still window for improvement. Although the cornerstone for laryngeal cancer eradication is to implement smoking cessation programs, survival progresses will be hopefully seen in the future. Introducing molecular biomarkers as predictive factors to determine which patients will benefit of preservation treatments may become one of the next steps to improve survival. Furthermore, the development of new therapeutic modalities joint to biomarkers to selectively apply such new therapy in these patients may help to define new modalities with improved survival. New inhibitors against Notch pathway, EGFR, VRK1 or DNA damage repair may become gold standard if we are able to identify patients that may benefit from them, either on survival or functional larynx preservation. It is the moment for an inflexion point on the way laryngeal cancer is clinically managed.     

Heroin dependence effects on some major and trace elements

In this study, 56 (14 control and 42 addicts) adult human subjects of both sexes of different periods of heroin dependence were subjected to the measurement of whole blood, serum, and red blood cell levels of some trace elements (zinc, managanese, iron copper, and bromine), as well as some major elements (phosphorus, sulfur, calcium, potassium, and chlorine). This was done by the energy-dispersive X-ray fluorescence (EDXRF) technique, in which copper and bromine showed a significant rise in whole blood (male) (22 and 32%, respectively), while zinc, iron, manganese, calcium, sulfur phosphorus, potassium, and chlorine showed a significant drop (49, 8, 25, 34, 21, 51, 61 and 72%, respectively) in proportion to the period of heroin intake (6 yr) and in comparison with the control group. No significant sexual variation has been reported.     

Plant uptake of major and minor mineral elements as influenced by soil acidity and liming

This study reports effects on soil solution chemistry and plant uptake of 55 elements (Ag, Al, As, B, Ba, Be, Bi, Br, Ca, Cd, Ce, Co, Cr, Cs, Cu, Dy, Er, Eu, Fe, Gd, Ge, Hf, Hg, Ho, K, La, Li, Lu, Mg, Mn, Mo, Na, Nb, Nd, Ni, P, Pb, Pr, Rb, S, Sb, Sc, Se, Si, Sm, Sr, Tb, Th, Tl, U, V, W, Y, Yb, Zn, Zr) by raising the pH using addition of fine-grained precipitated calcium carbonate at 20 rates (yielding a soil solution pH range of 5.2 – 7.8) to A horizon samples of an acid Cambisol, cultivating a common grass (Agrostis capillaris L.) and determining the soil solution, root and shoot concentrations of these elements at the end of the experiment. For many of these elements, there is little or no previous information about concentrations in soil solutions, or in plant biomass, as related to soil pH/acidity or addition of calcium carbonate. Soil solutions were obtained by high speed centrifugation and ultrafiltration (0.2 m) of samples at 60% water-holding capacity. Concentrations of elements were determined by ICP-ES or (in most elements) ICP-MS, using isotopes specified. Soil solution pH, HCO₃ and organic C were also determined.Concentrations of elements in the biomass of A. capillaris were usually inversely related to soil solution pH. The most apparent (p<0.001) inverse, though often curvilinear, relationships between pH and concentrations in shoot biomass were measured for Ag, As, B, Ba, Eu, Ge, Li, Mn, Ni, P and Sr. Positive relationships (p<0.05) were only measured in Ca, Hg, Mg, Mo and S. For concentrations in root biomass, relationships were mostly, but not always, of the same sign and of a similar strength. Though soil solution pH and concentrations of elements were usually quite closely correlated, pH and/or HCO^– ₃ concentration more often accounted for a higher share of the variability in biomass concentration of elements than did soil solution concentration of the same element.     

Cellular elements of the immune system in the larynx cancer, SEM study

Observations that certain primary tumors (solid ones) are infiltrated by cells which participate in immune responses tend us to examine this problem in spontaneously growing larynx carcinoma (ca. planoepitheliale). Our observations in SEM revealed within but also in surrounding of cancer infiltrations the presence of cellular elements belonging to the immune system like: lymphocytes, monocytes and macrophages. The most numerous of them, lymphocytes, are brought to the surrounding and tumor's territory by very rich vascular network (angiogenesis phenomenon). Bidirectional transmigration of the lymphocytes, observed mainly within the postcapillary venules, takes place through the cytoplasm of endothelial cells. It is most probably that they are lymphocytes of T-type which are involved in a cell mediated mechanisms of the immune response against a tumor. The lymphocytes are responsible also for the presence of monocytes and especially macrophages within a tumor's territory. These facts suggest that the human organism, in certain degree, is able to fight against malignant tissue by similar mechanisms which are involved in the rejection of the graft.     

Concentrations of heavy metals and related trace elements in some Ethiopian rift-valley lakes and their in-flows

Concentrations of heavy metals commonly known to impact the environment and other related trace elements were quantified in the water bodies of nine Ethiopian rift-valley lakes and six rivers (their inflows) as well as in effluents from two factories. In about half of the samples the concentrations of As was 10–700 g l^–1 and Se, ranged from 10 to 28 g l^–1, were much higher than the maximum permissible level (MPL) according to international standards for drinking water. Mercury (Hg) was detected in four lakes and one river with high values ranging from 2 to 165 g l^–1. Concentrations of Mo in three soda lakes were as high as 544–2590 g l^–1. Iron (Fe) was found in high concentrations (567–4969 g l^–1) in three lakes, which are known to be discolored from inorganic colloids. Levels of Cd, Pb, and Cr ranged between 5 and 9, 12 and 20 and 104 and 121 g l^–1, respectively. The rest of the heavy metals analyzed, Ba, Cu, Mn, Ni and Zn, were either not detected in the samples or were found in much lower concentrations than the MPL for drinking water. Effluent from a tannery contained about 15, 141, 523, and 19 g l^–1 of As, Cr, Fe, and Se, respectively, and effluent from a textile factory contained high concentrations of As (10.6), Hg (3.8) and Se (20) g l^–1. Compared to more industrialized regions and other African lakes the concentrations of heavy metals in Ethiopian rift-valley lakes (with the exception of the soda lakes) and their inflows were low.     

Effect of the ventricular folds in a synthetic larynx model

Within the human larynx, the ventricular folds serve primarily as a protecting valve during swallowing. They are located directly above the sound-generating vocal folds. During normal phonation, the ventricular folds are passive structures that are not excited to periodical oscillations. However, the impact of the ventricular folds on the phonation process has not yet been finally clarified.An experimental synthetic human larynx model was used to investigate the effect of the ventricular folds on the phonation process. The model includes self-oscillating vocal fold models and allows the comparison of the pressure distribution at multiple locations in the larynx for configurations with and without ventricular folds.The results indicate that the ventricular folds increase the efficiency of the phonation process by reducing the phonation threshold level of the pressure below the vocal folds. Two effects caused by the ventricular folds could be identified as reasons: (1) a decrease in the mean pressure level in the region between vocal and ventricular folds (ventricles) and (2) an increase in the glottal flow resistance.The reason for the first effect is a reduction of the pressure level in the ventricles due to the jet entrainment and the low static pressure in the glottal jet. The second effect results from an increase in the glottal flow resistance that enhances the aerodynamic energy transfer into the vocal folds. This effect reduces the onset threshold of the pressure difference across the glottis.     

Serum and tissue trace elements in patients with breast cancer in Taiwan

The objective of this study was to compare levels of four elements (zinc, copper, selenium, and iron) in the serum and tissue of 68 breast tumor patients (benign and malignant), from a teaching hospital in central Taiwan. Samples of normal tissue (5 cm away from tumor) were also taken from patients with malignant tumors. Only serum was taken from the 25 healthy persons in the control group. Results showed that Zn, Cu, Se, Fe, Cu/Zn, Cu/Se, and Cu/Fe were present in different amounts in the serum of each of the three groups. Zn and Se levels were lower in the serum of the two tumor groups compared to the control group. In tissue samples, Zn, Cu, Se, and Fe concentrations were different in each of the three groups. The malignant tissue had the highest levels of all four elements. In advanced-stage malignant tumors, levels of Cu and the ratios of Cu/Fe and Cu/Zn (in both serum and tissue) were highest. The ratios of serum Cu/Zn, Cu/Fe, and Cu/Se were also higher in malignant patients. The cutoff value of serum Cu/Zn was 1.2 (sensitivity and specificity were both 100%). The Cu/Zn ratio was highest in the advanced stages of cancer and was a better diagnostic tool for breast cancer than Cu/Se and Cu/Fe. The authors suggest that change of trace elements in serum and tissue might be useful and significant as biomarkers involving the initial plastic process.     

Selenium and selenium-antagonistic elements in nutritional cancer prevention

Selenium is an essential trace element with antioxidative, antimutagenic, antiviral and anticarcinogenic properties. There is increasing evidence that the dietary selenium intakes are sub-optimal in the populations of many countries and that human cancer mortalities would significantly decline if additional selenium was made available either through supplementation or the fortification of certain foods. An important property of selenium is its interaction with other elements that may be present in foods, the water, the workplace and the environment, e.g. As, Cu, Ni, Co, Cr, Mn, Zn, Cd, Sn, Pb, Hg, Bi, Mo, Ag, Au, etc. The sequestration of elements by selenium represents an efficient natural detoxification mechanism for some of these elements but also results in the physiological inactivation of selenium. Animal experiments confirm that the chronic exposure to low levels of these elements abolishes the cancer-protective effect of selenium. Human cancer is likewise significantly determined by the interactions of selenium with other elements, as evidenced by epidemiological, ecological and case-control studies. Cadmium, for example, is a key risk-increasing element for prostate cancer; for breast cancer, Cd, Cr, Zn are mainly contributing; for bronchial cancer (in smelter workers), Cd, As, Cr, Sb, Co, La, all these elements are in a reciprocal relationship with Se. While selenium remains the key cancer-protective trace element, the interpretation of its mode of action necessitates consideration of the effects of selenium antagonistic elements.     

Nutritional status and risks of potentially toxic elements in some paddy soils and rice tissues

This experiment was conducted to investigate the potential risk of toxic elements in paddy soils and rice straws, bran, and husked grains in Kuchesfahan, Gilan, Iran. The average content of total and DTPA-extractable of Cd, Cu, Fe, Mn, Ni, Pb, and Zn were 7.0, 26.3, 20728.8, 1516.7, 43.8, 16.6, and 211.8?mg kg^?1, and 0.32, 14.1, 97.3, 63.4, 1.7, 4.8, and 56.2?mg kg^?1, respectively. In addition, the average content of Cd, Cu, Fe, Mn, Ni, Pb, and Zn in rice grain was 0.16, 2.4, 135.5, 34.1, 2.0, 0.6, and 15.0?mg kg^?1, respectively. The average transfer factor for Cd, Cu, Fe, Mn, Ni, Pb, and Zn from soil to straw was 0.38, 0.16, 0.004, 0.13, 0.3, 0.04, and 0.09, respectively. The average values of estimated daily intake for Cd, Cu, Fe, Mn, Ni, Pb, and Zn through rice consumption for adult are respectively, estimated to be 0.0004, 0.005, 0.32, 0.08, 0.005, 0.0015, and 0.035?mg kg^?1 body weight per day. There was no health risk index (HRI) values for adult greater than 1 (except three samples for Fe, and one sample for Mn and Cd); indicated that intake of single metal through the consumption of rice was safe. The average of heath index (HI) value for rice consumption was 0.33 and 0.35 for adult and children, respectively. Therefore, combination of several potentially toxic elements may not cause risk to local residents. Spatial distributions of HRI were obtained for potentially toxic metals in husked grains.     

A study of glutathione status in the blood and tissues of patients with breast cancer

Glutathione plays an important role in the antioxidant system that is required for the maintenance of the redox status of the cell, defence against free radicals and detoxification of toxic compounds. Reduced glutathione (redGSH) can be converted to oxidized glutathione (GSSG) during oxidative stress. The ratio of redGSH/total glutathione can be regarded as an index of the redox status and a useful indicator of disease risks. We conducted experiments by the capillary zone electrophoresis method to investigate the alterations of the glutathione status in the blood and tissue samples from patients with breast cancer. The results showed that the levels of redGSH, GSSG, total glutathione and the ratio of redGSH/total glutathione were significantly decreased in the blood of the patients with breast cancer compared to those of the control subjects. The levels of various forms of glutathione were lower and more pronounced in stage III. In contrast, the levels of redGSH, GSSG, total glutathione and the redGSH/total glutathione ratio in breast cancer tissues were significantly increased relative to those of the adjacent cancer-free tissues, especially in stage II. We suggest that the high redGSH levels are associated with the enhancement of cell proliferation and resistance to apoptosis in the cancer cells, and the loss of the large amount of erythrocyte redGSH may be due to increased detoxification capacities and defence against oxidative stress. We propose that redGSH should be regarded as an important biochemical parameter for detecting breast malignancy.     

Evaluating tissue levels of the eight trace elements and heavy metals among esophagus and gastric cancer patients: A comparison between cancerous and non-cancerous tissues

BackgroundConsidering the affecting role of environmental factors including trace elements and heavy metals on the upper gastrointestinal (GI) cancers, there is paucity of empirical research in tissue evaluations.ObjectivesThe present study aimed to measure the tissue content of some trace elements and heavy metals such as zinc (Zn), chromium (Cr), manganese (Mn), tin (Sn), copper (Cu), aluminum (Al), lead (Pb), and iron (Fe) in esophagus and gastric cancerous tissues compared to the adjacent healthy tissues.MethodsIn a cross-sectional study, the aforementioned trace elements and heavy metals were evaluated among patients with esophagus and gastric cancers. During endoscopy, multiple samples were taken from cancerous lesions and the adjacent healthy tissues. The classic flame atomic absorption spectroscopy (FAAS) method was employed as the study framework.ResultsFifty patients with the mean age of 53.92 ± 8.73 were enrolled in the current study. Thirteen patients suffered from esophageal cancer and thirty-seven patients were afflicted with gastric cancer. The results revealed significant differences in the median concentrations of Zn, Cr, Sn and, Cu (P < 0.05) between the two groups. Although there were no significant changes in the tissue content in the esophageal samples, in the median concentrations of Zn, Cr and, Sn (P < 0.05) in gastric tissues, significant differences were observed. Further, the results indicated that gender enacted an affecting role in the level of some trace elements and heavy metals.ConclusionThe tissue contents of some elements were altered in gastric and esophageal cancers; this difference may reflect the underlying mechanism of cellular changing during the tumorigenesis or direct exposure of these elements. It seems that under the shade of other coexisting risk factors, larger cohort studies are suggested to be conducted to investigate other probable aspects in this area of interest.     

苔藓植物的化学元素含量及其特点

苔藓植物是化学元素最有效的积累者,在指示环境质量变化方面有其独到之处。本文阐述了苔藓植物体内地球化学元素的组成、含量、来源及其特点,用以揭示影响苔藓植物地球化学元素的因素,从而为苔藓植物作为指示生物提供更可靠的理论依据。苔藓植物体内所含的元素种类很多,主要来自大气沉降(如降水、降尘、扬尘、树冠淋溶等)和生长基质(如土壤、岩石等),元素含量受到区域空间、生态系统、苔藓种类以及时间季节的影响。苔藓植物体内地球化学元素含量可以指示环境条件(如区域空间、生态系统和时间)的差异。     

Trace elements and some extracellular antioxidant protein levels in serum of patients with laryngeal cancer

In this study, we investigated the levels of serum Zn, Cu, Mg, Mn, Fe, ceruloplasmin (Cp), transferrin (Trf), and albumin in laryngeal carcinoma and correlated their levels with the cancer stage. The sera from 35 patients with laryngeal cancer (10 at stage II, 12 at stage III, and 13 at stage IV) were extracted before treatment and compared with those from the healthy control group (n=15). Although serum Fe and Mn concentrations were lower in the laryngeal cancer groups (for all stages) than in the control group, the difference was not statistically significant (p>0.05). The higher Cu (p<0.001) and Cp (p<0.01) and lower Zn (p<0.01), Mg (p<0.001), and Trf (p<0.01) concentrations were found in laryngeal cancer groups (for each stage) when compared to the control group. In the comparison of stages II, III, and IV (with each other), all parameters were found to be statistically not significant (p>0.05). On the other hand, no meaningful difference was found in terms of the serum albumin level. In our opinion, alterations in the level of trace elements and antioxidant proteins, important for many metabolic processes, in laryngeal cancer may not be a reason for but is, in fact, a consequence of the disease itself.     

Galectin-4 in normal tissues and cancer

Galectin-4 belongs to a subfamily of galectins composed of two carbohydrate recognition domains within the same peptide chain. The two domains have all the conserved galectin signature amino acids, but their overall sequences are only approximately 40% identical. Both domains bind lactose with a similar affinity as other galectins, but their respective preferences for other disaccharides, and larger saccharides, are distinctly different. Thus galectin-4 has a property of a natural cross-linker, but in a modified sense since each domain prefers a different subset of ligands. Similarly to other galectins, galectin-4 is synthesized as a cytosolic protein, but can be externalized. During development and in adult normal tissues, galectin-4 is expressed only in the alimentary tract, from the tongue to the large intestine. It is often found in relatively insoluble complexes, as a component of either adherens junctions or lipid rafts in the microvillus membrane, and it has been proposed to stabilize these structures. Strong expression of galectin-4 can be induced, however, in cancers from other tissues including breast and liver. Within a collection of human epithelial cancer cell lines, galectin-4 is overexpressed and soluble in those forming highly differentiated polarized monolayers, but absent in less differentiated ones. In cultured cells, intracellular galectin-4 may promote resistance to nutrient starvation, whereas—as an extracellular protein—it can mediate cell adhesion. Because of its distinct induction in breast and other cancers, it may be a valuable diagnostic marker and target for the development of inhibitory carbohydrate-based drugs. Published in 2004. This revised version was published online in July 2006 with corrections to the Cover Date.