The association between serum folate and elderly diastolic hypertension: results from the NHANES (2007-2018).

AIM: To explore the association between serum folate concentration and the prevalence of elderly diastolic hypertension. This study aims to identify potential relationships that could inform further research into the mechanisms underlying hypertension management. METHODS: Data from six NHANES cycles (2007-2008, 2009-2010, 2011-2012, 2013-2014, 2015-2016, and 2017-2018) were analysed for individuals aged over 60. Weighted logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup and restricted cubic spline (RCS) regression explored the serum folate concentration and elderly diastolic hypertension relationship. RESULTS: This study included 9,419 participants (4,734 females and 4,685 males) with a mean age of 70.0 ± 7.0 years. Among them, 360 were diagnosed with diastolic hypertension. In the fully adjusted model, there was a negative correlation between serum folate concentration and the prevalence of diastolic hypertension (OR 0.65; 95% CI: 0.52-0.82). When serum folate concentration levels were divided into quartiles (in µg/dL), the ORs for diastolic hypertension corresponding to Q2 (1.29-1.98), Q3 (1.99-3.08), and Q4 (3.09-5.56) levels compared to Q1 (0.18-1.28) were 1.41 (95% CI: 0.60-3.33), 0.48(95% CI: 0.20-1.16), and 0.35 (95% CI: 0.16-0.74), respectively, with a P for trend <.05. Restricted cubic spline plots showed a negative correlation between serum folate concentration and the prevalence of diastolic hypertension (non-linearity: p = .495). Subgroup analysis indicated that the negative correlation between serum folate concentration and the prevalence of diastolic hypertension was more significant in female participants (interaction p = .009). CONCLUSION: Higher serum folate concentration is associated with a lower prevalence of diastolic hypertension in the elderly.

What is the context?Diastolic hypertension, characterised by high blood pressure during the relaxation phase of the heartbeat.It significantly elevates the risk of cardiovascular diseases such as heart attacks and strokes.This study examines how serum folate levels relate to diastolic hypertension in the elderly, aiming to uncover correlations that inform future management strategies.What is new?This study investigated the relationship between serum folate concentration and the prevalence of diastolic hypertension in individuals aged over 60.Analysing data from multiple cycles of the National Health and Nutrition Examination Survey (NHANES), researchers found a noteworthy correlation between higher serum folate levels and a lower prevalence of diastolic hypertension.This association remained significant even after adjusting for various factors such as age, sex, and other health variables.What is the impact?The findings underscore the potential significance of folate intake in lowering the prevalence of diastolic hypertension among the elderly.It suggests avenues for further research into nutritional interventions targeting hypertension in this vulnerable population, potentially leading to more effective preventive measures and improved health outcomes.

Enrichment of (8,4) single-walled carbon nanotubes through coextraction with heparin.

Heparin sodium salt is investigated as a dispersant for dispersing single-walled carbon nanotubes (SWNTs). Photoluminescence excitation (PLE) spectroscopy is used for identification and abundance estimation of the chiral species. It is found that heparin sodium salt preferentially disperses larger-diameter Hipco SWNTs. When used to disperse CoMoCAT nanotube samples, heparin has a strong preference for (8,4) tubes, which have larger diameter than the predominant (6,5) in pristine CoMoCAT samples. PLE intensity due to (8,4) tubes increases from 7% to 60% of the total after threefold extractions. Computer modeling verifies that the complex of (8,4) SWNTs and heparin has the lowest binding energy amongst the four semiconducting species present in CoMoCAT. Network field-effect transistors are successfully made with CoMoCAT/heparin and CoMoCAT/sodium dodecylbenzene sulfonate (SDBS)-heparin (x3), confirming the easy removability of heparin.

A miniaturized spatial temperature gradient capillary electrophoresis system with radiative heating and automated sample introduction for DNA mutation detection.

A miniaturized spatial temperature gradient CE system with automated sample introduction for DNA mutation detection was established. Continuous electrokinetic sample injection was achieved by combining an automated slotted-vial array sample introduction device to the spatial temperature gradient CE system. The temperature gradient was produced by a radiative heating system with a single graphite block heater, and the stability of the temperature gradient was investigated. The temperature variation of each measure point was 0.12-0.21% RSD (n=7) within 6 h. A 14-cm Teflon AF-coated silica capillary was used both as the separation channel and as the liquid-core waveguide tube of fluorescence signal. Under a temperature gradient from 54.8 to 59.5°C, a low range control mutation standard (209 bp) was separated within 4 min with only 5.6 nL sample consumption. Automated continuous sample introducing and changing were realized with a carryover of 3.3%. Utility of the system was further demonstrated by detecting K-ras gene mutations in paraffin tissue sections from two colorectal cancer patients.

[Study on the inducement and influential factors of callus with different organs of Glycyrrhiza uralensis].

OBJECTIVE: To investigate the influential factors and establish culture method for G. uralensis callus. METHODS: To study the possible effective factors of culture condition by comparing with different explants, light, plant hormones and its ratio. RESULTS: The hypocotyl was the best among different explants, its inducing ratios was 94%, and the callus occurred earliest. When the calluses were inoculated on MS + 6 - BA (1.0-2.0) mg/L + NAA (0.5-1.0) mg/L, adventitious buds formed. 2,4-D could induce non-embryogenic callus, the compounding proportions of 6 - BA and NAA could induce embryogenic callus. Light influenced induction and growth of callus. CONCLUSION: Different explants, components of hormone and light are the influencial factors of callus induction and growth of G. uralensis.

Theoretical study of the structural and electronic properties of SimGen and SimGen- (s = m + n

Ground-state structures, vibrational frequencies, HOMO-LUMO energy gap, electron affinities, and cluster mixing energy of binary semiconductor clusters SimGen in the range s = m + n

[Study on temperature measurement and control for microfluidic systems].

A technique for temperature control and measurement in microfluidic systems was developed. The technique is easy to be implemented in an analytical lab and the experimental setup is relatively simple and inexpensive. The parts for temperature measurement include a CCD camera, a fluorescence microscope and an image acquisition card. The spatial distribution and the temporal variation of temperature in microfluids were measured. The method is non-invasive and the spatial and temporal resolutions were 0. 8 microm and 40 ms, respectively a thermal control device was built using indium-tin-oxide (ITO) coated glass as heater, taking advantage of its transparent quality. The temperature could be controlled with a precision of +/-0.1 degrees C. The image processing procedure was optimized and the efficacy of the method was demonstrated.

Effects of microRNA-26b on proliferation and invasion of glioma cells and related mechanisms.

Neuroglioma is the most common primary malignant tumor in neurosurgery. Due to its short survival period and high patient mortality rate, neuroglioma is a major challenge in clinics. Elucidating the pathogenic mechanisms and associated molecular targets of neuroglioma can therefore benefit diagnosis and treatment of glioma. Previous studies have established the role of microRNA (miR)­26b in various tumors, including breast cancer, lymphoma and glioma. Its function and mechanism in neuroglioma, however, remains to be elucidated. In the present study, in vitro cultured U87 glioma cells were randomly divided into miR­26b mimic, miR­26b inhibitor and respective control (NC) groups. MTT assay was performed to detect the effect of miR­26b on cell proliferation, while a cell invasion assay detected its effects on cell invasion. Caspase­3 activity was also quantified to test cell apoptosis, followed by reverse transcription-quantitative polymerase chain reaction and western blotting to detect the variation of Bcl­2 expression under the effect of miR­26b. miR­26b mimics transfection upregulated its expression in U87 cells, which had significantly reduced Bcl­2 mRNA and protein expression levels and higher casapse3 activity, and inhibited cell proliferation and invasion compared with the control group. The transfection of miR­26b inhibitor, in contrast, facilitated U87 cell proliferation and invasion, inhibited caspase­3 activity and elevated Bcl­2 mRNA/protein expression. In conclusion, miR­26 could facilitate apoptosis and inhibit proliferation/invasion of neuroglioma cells via downregulating Bcl­2 expression and potentiating caspase-3 activity.

Role of galectin-3 in plasma as a predictive biomarker of outcome after acute intracerebral hemorrhage.

OBJECTIVE: Inflammation is involved in pathophysiological mechanisms underlying secondary brain injury after intracerebral hemorrhage. Enhanced circulating levels of galectin-3, a proinflammatory cytokine, have close relation to poor prognosis of some inflammatory illnesses. This study was designed to investigate whether plasma galectin-3 levels are related to the inflammation, severity and prognosis following intracerebral hemorrhage. METHODS: In this observational, prospective study, plasma galectin-3 levels of 110 patients and 110 controls were determined. We further assessed the association of galectin-3 levels with inflammation reflected by systemic C-reactive protein levels, severity indicated by hematoma volumes and National Institutes of Health Stroke Scale (NIHSS) scores, and endpoints including 1-week mortality, 6-month mortality, 6-month overall survival and 6-month unfavorable outcome (modified Rankin Scale score>2). RESULTS: Plasma galectin-3 levels of patients were significantly higher than those of controls. Galectin-3 was identified as an independent prognostic predictor for 1-week mortality, 6-month mortality, 6-month overall survival and 6-month unfavorable outcome, as well as had strong relation to C-reactive protein levels, hematoma volumes and NIHSS scores. Compared with NIHSS scores and hematoma volumes, plasma galectin-3 levels had similar areas under receiver operating characteristic curve (AUC). Moreover, galectin-3 levels significantly improved AUCs of NIHSS scores or hematoma volumes alone for prediction of 6-month mortality and 6-month unfavorable outcome. CONCLUSIONS: Elevated plasma galectin-3 levels are strongly associated with the inflammation, severity and poor prognosis after intracerebral hemorrhage, indicating galectin-3, involved in brain inflammation, might have the potential to be a prognostic biomarker for hemorrhagic stroke.

[Preparation of Coated CMC-Fe0 Using Rheological Phase Reaction Method and Research on Degradation of TCE in Water].

The coated nanoscale zero-valent iron (coated CMC-Fe0) was synthesized with cheap and environment friendly CMC as the coating agent using rheological phase reaction. The sample was characterized by means of XRD, SEM, TEM and N2 adsorption-stripping and used to study reductive dechlorination of TCE. The experimental results indicated that the removal rate of TCE was about 100% when the CMC-Fe0 dosage was 6 g x L(-1), the initial TCE concentration was 5 mg x L(-1) and the reaction time was 40 h. The TCE degradation reaction of coated CMC-Fe0 followed a pseudo-first-order kinetic model. Finally, the product could be simply recovered.

Intravascular ultrasonic-photoacoustic (IVUP) endoscope with 2.2-mm diameter catheter for medical imaging.

Intravascular ultrasound (IVUS) imaging is extremely important for detection and characterization of high-risk atherosclerotic plaques as well as gastrointestinal diseases. Recently, intravascular photoacoustic (IVPA) imaging has been used to differentiate the composition of biological tissues with high optical contrast and ultrasonic resolution. The combination of these imaging techniques could provide morphological information and molecular screening to characterize abnormal tissues, which would help physicians to ensure vital therapeutic value and prognostic significance for patients before commencing therapy. In this study, integration of a high-frequency IVUS imaging catheter (45MHz, single-element, unfocused, 0.7mm in diameter) with a multi-mode optical fiber (0.6mm in core diameter, 0.22 NA), an integrated intravascular ultrasonic-photoacoustic (IVUP) imaging catheter, was developed to provide spatial and functional information on light distribution in a turbid sample. Simultaneously, IVUS imaging was co-registered to IVPA imaging to construct 3D volumetric sample images. In a phantom study, a polyvinyl alcohol (PVA) tissue-mimicking arterial vessel phantom with indocyanine green (ICG) and methylene blue (MB) inclusion was used to demonstrate the feasibility of mapping the biological dyes, which are used in cardiovascular and cancer diagnostics. For the ex vivo study, an excised sample of pig intestine with ICG was utilized to target the biomarkers present in the gastrointestinal tumors or the atherosclerotic plaques with the proposed hybrid technique. The results indicated that IVUP endoscope with the 2.2-mm diameter catheter could be a useful tool for medical imaging.

Comparison of standard large trauma craniotomy with routine craniotormy in treatment of acute subdural hematoma.

OBJECTIVE: To compare the therapeutic effect and indication between standard large trauma craniotomy and routine craniotomy. METHODS: There were 97 patients in the standard large trauma craniotomy group and 110 patients in the routine craniotomy group. The mortality, postoperative ICP (intracranial pressure), ratio of pupil rebound, complication and results of six month follow-up after operation were compared between the two groups. RESULTS: Fifteen patients (15.6%) died in the standard large trauma craniotomy group and 30 (27.7%) in the routine craniotomy group. The postoperative mean ICP was 3.75 kPa+/-1.89 kPa in the standard large trauma craniotomy group and 5.11 kPa+/-1.57 kPa in the routine craniotomy group. The pupil rebound was found in 47 patients (61.0%) in the standard large trauma craniotomy group and in 41 patients (46.1%) in the routine craniotomy group (P<0.01). The rate of complication was lower in the standard large trauma craniotomy group, but no obvious difference in long-term therapeutic effect was found between the two groups. CONCLUSIONS: Standard large trauma craniotomy can attenuate brain hernia and the mortality of the patients with acute subdural hematoma. The incidence of complication can also be decreased. But the long term life quality of the patients can not be improved.

[Hepatitis c virus genotype research by ABC programs of 5'-NCR restriction endonuclease digestion].

OBJECTIVE: In order to fully understand hepatitis c virus (HCV) genotype 3b, 1a, 2b and 6a infection in China, We built HCV 5'-noncoding region (5'-NCR) of different genotypes and subtypes. METHODS: The classification HCV into variable genotypes (subtypes) was carried on by programs A, B and C A. Using a combination of three restriction endonuclease BHH' (BsrB I, Hae II, Hinf I) digestions at the same time. The distinct genotypes were classified into 5 groups: genotype 1 (1a, 1b), 6a, 2 (2a, 2b), genotype 3 (3a, 3b), genotype4 (4a). B. With regard to genotype 1, we could distinguish subtype 1a from 1b using BstU I digestion. C. Using restriction endonuclease Hae III, genotype 2a, 2b, 3b, 4a, 6a are differentiated respectively. RESULTS: (1) HCV genotype 1a, 1b, 2a, 2b, 3a, 3b, 4a, 6a are fully discriminated by comparison with the genotypes regular samples. (2) Of the 93 patients, HCV genotype distribution in China was 66.67% for 1b, 18.28% for 2a, 3.23% for 1b/2b, 3b, 2b respectively. 2.15% for 2a/2b, 1b/2a respectively. 1.08% for 1a. CONCLUSION: This research indicated that adoption of HCV 5'-NCR A B C restriction endonuclease digestions techniques, might be sensitive and efficient to detect HCV and discriminate HCV genotype (subtypes) 1a to 6a.

[Studies on sequential injection spectrophotometric system using a reflective flow cell for process analysis].

A reflective flow cell was developed and coupled to a sequential injection system and optical fiber photometric detection system based on emitting diode light source. A multistrand bifurcated optical fiber was coupled with incident light, detector and flow cell. Optical fibers were used to carry light from the electronics unit to a reflective flow-through cell and back. The liquid flow path through the cell is linear with a large exit aperture such that bubbles are not trapped in the optical path. The optical arrangement is such that the incident light crosses the liquid flow orthogonally and is reflected back to the receiver fiber. This arrangement reduces the reflective index sensitivity by an order of magnitude relative to a conventional flow cell. The cell showed good immunity to refractive index and air bubble effects. The chromogenic reaction of chloride ion with mercury thiocyanate-iron(III) was used as a model reaction to optimize the experiment system and check the optical system. The reflectance of the reaction was monitored with blue emitting diode. The linear range was 0-100 mg x L(-1) Cl-. A detection limit (3sigma) of 1.2 mg x L(-1), precision of 1.5% (n = 11), and a throughput of 30 samples per hour were achieved.

Increased plasma 8-iso-prostaglandin F2α concentration in severe human traumatic brain injury.

BACKGROUND: 8-Iso-Prostaglandin F2α (8-iso-PGF2α) is considered as a gold standard for measuring oxidative stress in vivo. The present study was undertaken to investigate plasma 8-iso-PGF2α concentrations in severe human traumatic brain injury (TBI) and to analyze its correlation with disease outcome. METHODS: One hundred six healthy subjects and 106 severe TBI patients were recruited. The correlations of plasma 8-iso-PGF2α concentration with 1-year mortality and unfavorable outcome (Glasgow Outcome Scale score of 1-3) were analyzed. RESULTS: Thirty-one patients (29.2%) died and 48 patients (45.3%) had an unfavorable outcome at 1 year after TBI. Patients had significantly higher plasma 8-iso-PGF2α levels compared to healthy controls (572.1±157.5 pg/ml vs. 84.3±18.9 pg/ml, P<0.001). A multivariate analysis selected plasma 8-iso-PGF2α level as an independent predictor for 1-year unfavorable outcome [odds ratio (OR) 1.401, 95% confidence interval (CI) 1.107-2.371, P=0.005] and mortality (OR 1.609, 95% CI 1.113-3.142, P=0.003). A receiver operating characteristic curve analysis showed plasma 8-iso-PGF2α level predicted 1-year unfavorable outcome [area under curve (AUC), 0.871; 95% CI, 0.792-0.928] and mortality (AUC, 0.881; 95% CI, 0.804-0.936) as statistically significantly. The prognostic value of 8-iso-PGF2α was similar to that of Glasgow Coma Scale score for 1-year clinical outcomes (both P>0.05). However, 8-iso-PGF2α did not improve the prognostic value of Glasgow Coma Scale score for 1-year clinical outcomes (both P>0.05). CONCLUSIONS: Plasma 8-iso-PGF2α level is highly associated with 1-year clinical outcomes of TBI.

High concentrations of visfatin in the peripheral blood of patients with acute basal ganglia hemorrhage are associated with poor outcome.

Higher plasma visfatin concentration has been associated with clinical outcomes of traumatic brain injury. No published information exists to date about change in plasma visfatin after intracerebral hemorrhage. This study included one hundred and twenty-eight healthy controls and 128 patients with intracerebral hemorrhage. The unfavorable outcome was defined as modified Rankin Scale score >2 at 6 months. The patients had higher plasma visfatin measurements than control subjects. Plasma visfatin levels were highly correlated with National Institutes of Health Stroke Scale score and plasma C-reactive protein levels in the patients. A multivariate analysis identified plasma visfatin level as an independent predictor for 6-month mortality and unfavorable outcome. According to receiver operating characteristic curve analysis, the predictive value of the plasma visfatin concentration was similar to National Institutes of Health Stroke Scale score. In a combined logistic-regression model, visfatin improved the predictive value of National Institutes of Health Stroke Scale score for 6-month unfavorable outcome. Thus, increased plasma visfatin level is associated with 6-month clinical outcomes after intracerebral hemorrhage.

Leptin as a marker for severity and prognosis of aneurysmal subarachnoid hemorrhage.

Leptin has been identified as a plasma marker for outcomes in traumatic brain injury and intracerebral hemorrhage. We further investigated whether leptin might serve as a marker for severity and prognosis in aneurysmal subarachnoid hemorrhage. One hundred and eight consecutive patients and 108 sex and age - matched healthy subjects were recruited. Plasma leptin levels were measured by enzyme-linked immunosorbent assay. Clinical severity was assessed using World Federation of Neurological Surgeons score and Fisher score. Mortality and poor long-term outcome (Glasgow outcome scale scores of 1-3) at 6 months were recorded. Plasma leptin levels on admission were substantially higher in patients than in healthy controls, and were significantly associated with the clinical severity. There was also a significant association between leptin levels and clinical outcomes at 6 months in multivariate logistic regression analysis. Using receiver operating characteristic curves, we calculated areas under the curve for clinical outcomes at 6 months. The predictive performance of leptin was similar to, but did not obviously improve those of World Federation of Neurological Surgeons score and Fisher score. Thus, leptin may indicate clinical severity of the initial bleeding and also have prognostic value for clinical outcomes in aneurysmal subarachnoid hemorrhage and may therefore help in guiding treatment decisions in the setting of aneurysmal subarachnoid hemorrhage.

Prognostic value of copeptin: one-year outcome in patients with traumatic brain injury.

High plasma copeptin level has been associated with one-month mortality after traumatic brain injury. However, not much is known regarding its relation with long-term outcome. Thus, we investigated the ability of copeptin to predict 1-year outcome in patients with traumatic brain injury. One hundred and six healthy controls and 106 patients with acute severe traumatic brain injury were included. Plasma samples were obtained on admission. Its concentration was measured by enzyme-linked immunosorbent assay. Forty-eight patients (45.3%) suffered from unfavorable outcome (Glasgow Outcome Scale score of 1-3) and 31 patients (29.2%) died in 1 year after traumatic brain injury. Upon admission, plasma copeptin level in patients was substantially higher than that in healthy controls. A forward stepwise logistic regression selected plasma copeptin level as an independent predictor for 1-year unfavorable outcome and mortality of patients. A receiver operating characteristic curve analysis showed plasma copeptin level predicted 1-year unfavorable outcome and mortality obviously. The predictive value of the copeptin concentration was thus similar to that of Glasgow Coma Scale score for the prediction of unfavorable outcome and mortality after 1 year. In a combined logistic-regression model, copeptin improved the area under curve of Glasgow Coma Scale score for the prediction of unfavorable outcome and mortality after 1 year, but the differences were not significant. Thus, copeptin level is a useful, complementary tool to predict functional outcome and mortality 1 year after traumatic brain injury.

Automated sampling system for the analysis of amino acids using microfluidic capillary electrophoresis.

An improved automated continuous sample introduction system for microfluidic capillary electrophoresis (CE) is described. A sample plate was designed into gear-shaped and was fixed onto the shaft of a step motor. Twenty slotted reservoirs for containing samples and working electrolytes were fabricated on the "gear tooth" of the plate. A single 7.5-cm long Teflon AF-coated silica capillary serves as separation channel, sampling probe, as well as liquid-core waveguide (LCW) for light transmission. Platinum layer deposited on the capillary tip serves as the electrode. Automated continuous sample introduction was achieved by scanning the capillary tip through the slots of reservoirs. The sample was introduced into capillary and separated immediately in the capillary with only about 2-nL gross sample consumption. The laser-induced fluorescence (LIF) method with LCW technique was used for detecting fluorescein isothiocyanate (FITC)-labeled amino acids. With electric-field strength of 320 V/cm for injection and separation, and 1.0-s sample injection time, a mixture of FITC-labeled arginine and leucine was separated with a throughput of 60/h and a carryover of 2.7%.

Imperatorin is responsible for the vasodilatation activity of Angelica Dahurica var. Formosana regulated by nitric oxide in an endothelium-dependent manner.

OBJECTIVE: To demonstrate the vasodilatation activity of the coumarin-containing Angelica dahurica var. formosana and to further analyze active components in the herb extracts. METHODS: (1) The vasodilatation effects induced by different extracts (cyclohexane, ethyl acetate, acetone, methanol, 95 % ethanol and water) of Angelica dahurica var. formosana on mouse thoracic aorta pre-contracted with phenylephrine were investigated. (2) The amount of imperatorin and isoimperatorin in each extract was measured by high-performance liquid chromatography. (3) The vasodilatation effects of imperatorin and isoimperatorin on mouse thoracic aorta were compared using the same in vitro method. (4) The vasodilatation mechanism of imperatorin in the mouse thoracic aorta pre-contracted with phenylephrine was studied using the methods of denuded endothelium, NG-nitro-L-arginine methylester (L-NAME, a nitric oxide synthase inhibitor), and propranolol. RESULTS: (1) The cyclohexane and ethyl acetate extracts of Angelica dahurica var. formosana decreased the maximal response of phenylephrine-induced mouse thoracic aorta contraction dose-dependently, with 50% inhibiting concentration (IC(50)) values of 35.3+/-12.4 mg/L and 40.5+/-12.0 mg/L, respectively. The vasodilatation effect of imperatorin and isoimperatorin was dose-dependent. (2) The cyclohexane extract, showing the strongest vasodilatation effect, possessed the highest contents of imperatorin (4.09%) and isoimperatorin (0.27%, w/w). There was a correlation between the vasodilatation activity and the contents of imperatorin and isoimperatorin in the extracts. (3) The vasodilatation effect of imperatorin was about 4-fold stronger than that of isoimperatorin. (4) The vasodilatation effect of imperatorin was signifificantly attenuated to 24.88%+/-4.06% in the denuded endothelium group compared with the intact endothelium group. And 1 mmol/L L-NAME reduced the imperatorin-induced vasorelaxation by 32.18 %+/-11.29 %. CONCLUSIONS: The principal effective component of Angelica dahurica var. Formosana was found to be imperatorin. Imperatorin-induced vasodilatation is at least partially regulated by nitric oxide, and has no correlation to beta-receptor.

[Modified retention elements of removable reverse headgear appliances].

OBJECTIVE: Retention elements were added in the removable reverse headgear appliances in order to achieve better treatment effects of skeletal Class III malocclusion. METHODS: Eighteen patients who needed treatments with reverse headgear appliances were randomly and equally divided into two groups with traditional type of retention elements (T group) and modified type of retention elements (M group) respectively. For the modified type appliances, an adams clasp was added in the position of central incisors on the basis of the traditional type. The minimum dislocating force for both types was measured with the same forcemeter in the first and second visit, respectively. The occurrence of dislocation caused by traction was recorded during the visits of the first three months. RESULTS: The M group showed significantly greater retention than the T group. The minimum dislocating force for M group was larger in the first and second visit (P<0.01, P<0.001). Furthermore, during the first three months, two times of dislocation occurred in M group while it was nine times for T group, indicating great difference in retention (P< 0.05). CONCLUSION: Adding an adams clasp in the position of upper central incisors could effectively prevent the downward dislocation of the appliance when traction force was applied. Accordingly, the therapeutic efficacy was greatly improved.