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1.
Yitao Luo Chengqiang Zhang Li Ma Yuxiao Zhang Zhengyuan Liu Li Chen Rui Wang Yujing Luan Yulan Rao 《Journal of lipid research》2022,63(6):100228
7-dehydrocholesterol (7-DHC) and cholesterol (CHOL) are biomarkers of Smith-Lemli-Opitz Syndrome (SLOS), a congenital autosomal recessive disorder characterized by elevated 7-DHC level in patients. Hair samples have been shown to have great diagnostic and research value, which has long been neglected in the SLOS field. In this study, we sought to investigate the feasibility of using hair for SLOS diagnosis. In the presence of antioxidants (2,6-ditert-butyl-4-methylphenol and triphenylphosphine), hair samples were completely pulverized and extracted by micro-pulverized extraction in alkaline solution or in n-hexane. After microwave-assisted derivatization with N,O-Bis(trimethylsilyl)trifluoroacetamide, the analytes were measured by GC-MS. We found that the limits of determination for 7-DHC and CHOL were 10 ng/mg and 8 ng/mg, respectively. In addition, good linearity was obtained in the range of 50–4000 ng/mg and 30–6000 ng/mg for 7-DHC and CHOL, respectively, which fully meets the requirement for SLOS diagnosis and related research. Finally, by applying the proposed method to real hair samples collected from 14 healthy infants and two suspected SLOS patients, we confirmed the feasibility of hair analysis as a diagnostic tool for SLOS. In conclusion, we present an optimized and validated analytical method for the simultaneous determination of two SLOS biomarkers using human hair. 相似文献
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An epithermal neutron activation method is used to determine the concentration of mineral elements in human dental enamel.
A large number (252) of samples from ancient and modern origins are analyzed. The analytical results are mathematically processed
using a statistical multivariant method. This allows to differentiate deciduous from permanent teeth and decayed from sound
enamel. It is also possible to distinguish the teeth coming from two different necropoles. The origin and the localization
of determined elements in the mineralized part, or in the aqueous-organic part, of enamel is suggested. Their role, as witnessed
in the physiopathological phenomena of dental enamel, is discussed. 相似文献
6.
We have previously reported that intralobular salivary duct cells contain an amiloride-sensitive Na+ conductance (probably located in the apical membranes). Since the amiloride-sensitive Na+ conductances in other tight epithelia have been reported to be controlled by extracellular (luminal) Na+, we decided to use whole-cell patch clamp techniques to investigate whether the Na+ conductance in salivary duct cells is also regulated by extracellular Na+. Using Na+-free pipette solutions, we observed that the whole-cell Na+ conductance increased when the extracellular Na+ was increased, whereas the whole-cell Na+ permeability, as defined in the Goldman equation, decreased. The dependency of the whole-cell Na+ conductance on extracellular Na+ could be described by the Michaelis-Menten equation with a K
m
of 47.3 mmol/1 and a maximum conductance (G
max) of 2.18 nS. To investigate whether this saturation of the Na+ conductance with increasing extracellular Na+ was due to a reduction in channel activity or to saturation of the single-channel current, we used fluctuation analysis of
the noise generated during the onset of blockade of the Na+ current with 200 μmol/l 6-chloro-3,5-diaminopyrazine-2-carboxamide. Using this technique, we estimated the single channel
conductance to be 4 pS when the channel was bathed symmetrically in 150 mmol/l Na+ solutions. We found that Na+ channel activity, defined as the open probability multiplied by the number of available channels, did not alter with increasing
extracellular Na+. On the other hand, the single-channel current saturated with increasing extracellular Na+ and, consequently, whole-cell Na+ permeability declined. In other words, the decline in Na+ permeability in salivary duct cells with increasing extracellular Na+ concentration is due simply to saturation of the single-channel Na+ conductance rather than to inactivation of channel activity.
Received: 27 July 1995/Revised: 7 December 1995 相似文献
7.
The size relationship between the crown area of the lower canines (Cs), third (P3s) and fourth premolars (P4s), and first
molars (M1s) in hominids is examined by means of the regression analysis. The lower P3 seem to be under the influence of those
factors that control both the size of the anterior and posterior teeth, and the P4:P3 size ratio is related to the relative
size of the anterior and posterior dentitions. So, the P4>P3 sequence is associated with the megadontia and hipermegadontia
of the posterior teeth, whereas the expansion of the anterior teeth produces the P3>P4 sequence. We consider the P4:P3 size
ratio as an excellent indicator of the taxonomic and philogenetic status of fossil hominids. 相似文献
8.
Occurrence of heavy metals,sodium, calcium,and potassium in human hair,teeth, and nails 总被引:1,自引:0,他引:1
Barbara Nowak 《Biological trace element research》1996,52(1):11-22
Heavy metals in biological samples: nails, teeth, and hair were examined during 1991–1993. Investigations of biological samples
(hairn=249 samples, teethn=145, nailsn=80 samples) were provided for inhabitants of selected towns in Beskid Śląski. The towns are small mountain towns in southern
Poland: Wista, Szczyrk, Istebna, Koniaków, and Jaworzynka. The analysis of ANOVA and MANOVA variances were used for biological
samples in the context of age, sex, and type of samples for 12 elements (Pb, Cd, Cr, Zn, Fe, Cu, Mn, Ni, Co, Ca, Na, and K).
The matrix correlation and cluster analysis were applied to explain the behavior of metals in human hair, teeth, and nails. 相似文献
9.
Katherine Coffing Craig Feibel Meave Leakey Alan Walker 《American journal of physical anthropology》1994,93(1):55-65
A piece of mandible and several isolated teeth are reported from fluviatile sediments older than 4 million years at East Lake Turkana. They most closely resemble hominids from Laetoli, Tanzania and Hadar, Ethiopia which have been assigned to Australopithecus afarensis. © 1994 Wiley-Liss, Inc. 相似文献
10.
Tetsuya Matsumoto Mitsuo Kaku Kazuhiro Tateda Nobuhiko Furuya Yoichi Hirakata Keizo Yamaguchi 《Microbiology and immunology》1994,38(4):287-293
We evaluated antibody-coated bacteria (ACB) in expectorated sputum to discriminate contaminating or colonizing organisms from true pathogens. We examined 60 expectorated sputum samples from 51 patients with lower respiratory infections (chronic obstructive pulmonary disease 25, pneumonia 20, purulent tracheobronchitis 6). All samples were examined with quantitative culture and immunofluorescent demonstration of ACB. From the results of quantitative culture, we divided specimens into pathogen-isolated and pathogen-free samples. Among pathogen-isolated samples, in which we isolated accepted pathogenic organisms at ≥ 107 colony-forming units per ml, 16 of 23 samples were ACB-positive (69.5%). In contrast, among pathogen-free samples, in which we isolated accepted pathogens at < 107 colony forming units per ml or only upper respiratory flora, only 3 of 37 samples were ACB-positive (8.1%). The ACB-positive rate was significantly higher in pathogen-isolated than in pathogen-free samples (P < 0.001). Consequently, detecting ACB in expectorated sputum shows good potential as another criterion for distinguishing contaminating or colonizing organisms from true pathogens. 相似文献