Computer simulation of optimal lipped polyethylene liner orientation against prosthetic impingement.

BACKGROUND: Lipped or elevated acetabular liners are to improve posterior stability and are widely used in hip arthroplasty. However, concerns of increasing impingement exist when using such liners and optimal orientation of the elevated rim remains unknown. We aimed to identify the impact of lipped liner on the range of motion (ROM) before impingement and propose its optimal orientation. METHODS: An isochoric three-dimensional model of a general hip-replacement prosthesis was generated, and flex-extension, add-abduction and axial rotation were simulated on a computer. The maximum ROM of the hip was measured before the neck impinged on the liner. Different combinations of acetabular anteversion angles ranging from 5 to 30 degrees, and lipped liner orientations from posterior to anterior were tested. RESULTS: When acetabular anteversion was 10 or 15 degrees, placing the lip of the liner in the posterosuperior of the acetabulum allowed satisfactory ROM in all directions. When acetabular anteversion was 20 degrees, extension and external rotation were restricted. Adjusting the lip to the superior restored satisfactory ROM. When acetabular anteversion was 25 degrees, only placing the lip into the anterosuperior could increase extension and external rotation to maintain satisfactory ROM. CONCLUSIONS: This study showed that optimal lipped liner orientation should depend on acetabular anteversion. When acetabular anteversion was smaller than 20 degrees, placing lip in the posterior allowed an optimally ROM. When acetabular anteversion was greater than 20 degrees, adjusting lip to the anterior allowed a comprehensive larger ROM to avoid early impingement.

[Risk factors of death cases of hand-foot-and-mouth disease in Hunan province].

OBJECTIVE: To study risk factors of death cases of hand foot and mouth diseases (HFMD) in Hunan province, so as to provide scientific evidence for further prevention and control. METHODS: The 105 death cases of HFMD between January and October, 2010 in Hunan Province were selected as case group; and the 210 survival cases of serious HFMD, which were matched by gender and resident places with a ratio at 2:1 in the same period in Hunan were selected as control group. The basic information, hospitalized experience and previous medical history had been surveyed and the relevant risk factors were analyzed by single factor and multi-factor logistic regression. RESULTS: In case group, 79.05% (83/105) of the cases lived in rural area and 9.52% (10/105) of the cases lived in urban-rural midst area. In control group, 87.62% (184/210) of the cases lived in rural area and 11.43% (24/210) of the cases lived in urban-rural midst area. In case group, 59.05% (62/105) of the patients first visited rural (private) clinics and 20.00% (21/105) first visited community hospitals in villages and towns; while in control group, 43.81% (92/210) and 13.33% (28/210) chose rural (private) clinics and community hospitals in villages and towns as the first choice respectively.22.86% (24/105) of the case group and 39.05% (82/210) of the control group were diagnosed as HFMD in their first visit to hospital.27.62% (29/105) of the case group and 7.14% (15/210) in control group were provided pyrazolone in the treatment. For glucocorticoid, 80.95% (85/105) and 5.71% (6/105) of the case group were given as treatment by rural (private) clinics and community hospitals in villages and towns separately; while the proportions in the control group were 41.43% (87/210) and 0.48% (1/210) respectively. For antibiotics, 35.24% (37/105) and 23.81% (25/105) of the case group were prescribed by rural (private) clinics and community hospitals in villages and towns separately; while the percentages in the control group were 15.71% (33/210) and 7.14% (15/210). 3.81% (4/105) of the case group and 11.90% (25/210) of the control group were vaccinated in one month before the onset. The results of single-factor logistic regression indicated that living in rural areas (OR = 0.075, 95%CI: 0.016 - 0.343) and in rural-urban midst areas (OR = 0.069, 95%CI: 0.013 - 0.368), diagnosis of HFMD in the first visit to hospital (OR = 0.463, 95%CI: 0.271 - 0.788) and vaccination one month before the onset (OR = 0.293, 95%CI: 0.099 - 0.866) were four protective factors; while rural (private) clinics as the first choice (OR = 4.717, 95%CI: 1.891 - 11.767), community hospital in villages and towns as the first choice (OR = 5.250, 95%CI: 1.883 - 14.641), medication of pyrazolone (OR = 4.961, 95%CI: 2.520 - 9.766), medication of glucocorticoid in rural (private) clinics (OR = 6.009, 95%CI: 3.435 - 10.510) and in community hospital in villages and towns (OR = 12.667, 95%CI: 1.505 - 106.638), medication of antibiotics in rural (private) clinics (OR = 2.918, 95%CI: 1.690 - 5.040) and in community hospital in villages and towns (OR = 4.062, 95%CI: 2.036 - 8.108) were seven risk factors. The results of multi-factors logistic regression showed that medication of pyrazolone (OR = 2.311, 95%CI: 1.062 - 5.030), medication of glucocorticoid in rural (private) clinics (OR = 5.480, 95%CI: 3.039 - 9.880), medication of antibiotics in rural (private) clinics (OR = 2.430, 95%CI: 1.301 - 4.538) and medication of antibiotics in community hospitals in villages and towns (OR = 3.344, 95%CI: 1.477 - 7.569) were the risk factors of death of HFMD. CONCLUSION: The risk factors of HFMD deaths include the medication of pyrazolone, glucocorticoid and antibiotics by rural (private) clinics and medical institutions in villages and towns. The department concerned should revise the technical manual to standardize the medication of the above drugs.

Effects of the equimolarly mixed cationic-nonionic surfactants of didodecyldimethylammonium bromide and polyoxyethylene sorbitan monooleate 80 on serum proteins-spectroscopic study.

Liposomes are a common delivery vehicle for drugs or biologicals, but some common surfactants used as liposome components may cause denaturation and malfunction of serum proteins and cell surface proteins. In this study, we examined the effects of liposome lipid didodecyldimethylammonium bromide (DDAB), nonionic polyoxyethylene sorbitan monooleate 80 (Tween 80), and the equimolar mixture on the properties of serum proteins. Bovine serum albumin was selected as the main model protein, and the effects of the DDAB, Tween 80, and a 1:1 mixture on its spectroscopic behavior were investigated. The effects of surfactants on the five major serum proteins: human serum albumin, apolipoprotein A1, transferrin, fibrinogen and immunoglobulin G were also examined. Finally, the results were verified on human serum. The results indicated that weak interactions exist between human serum proteins and the equimolar mixture of DDAB-Tween 80, significantly different from the strong interactions of DDAB and Tween 80 with proteins. The salient features of cationic-nonionic surfactants enable their use in liposome composition, with improved drug delivery efficiency.

[Studies on antitumor effects of podophyllotoxin nanoliposome].

OBJECTIVE: To compare the antitumor effects of the podophyllotoxin nanoliposome and the suspensions of podophyllotoxin in bearing-tumor mice. METHOD: The experimental mice were inoculated by suspension liquid of tumor cell in axillary region near the forelimb, 0.2 mL each. The mice had been randomly divided into 8 groups 24 h latter. The podophyllotoxin nanoliposome, suspension liquid of the podophyllotoxin, CX or NS was given to each group respectively. Except CX was given by celiac injection once, the other groups were injected every 4 days for three times. The mice were killed by hauling necks on the twelfth day after treatment, the tumor was weighed and the inhibitory rate was calculated. RESULT: When the dosage of podophyllotoxin nanoliposome and the suspensions of podophyllotoxin reached 5.0 mg x kg(-1), the rate of inhibiting tumor were 52.37% and 38.25% to the H22 liver cancer of mice respectively. CONCLUSION: Podophyllotoxin nanoliposome and the suspensions of podophyllotoxin have the effect in anti-liver cancer. And podophyllotoxin nanoliposome have stronger inhibitory rate compared with suspension liquid of the podophyllotoxin in same dose.

Correlation analysis of EV71 detection and case severity in hand, foot, and mouth disease in the Hunan Province of China.

An increase in the incidence of hand, foot and mouth disease (HFMD) cases has been observed in the Hunan province of mainland China since 2009 with a particularly higher level of severe cases in 2010-2012. Intestinal viruses of the picornaviridae family are responsible for the human syndrome associated with HFMD with enterovirus 71 (EV71) and Coxsackievirus A16 (Cox A16) being the most common causative strains. HFMD cases associated with EV71 are generally more severe with an increased association of morbidity and mortality. In this study, the etiology surveillance data of HFMD cases in Hunan province from March 2010 to October 2012 were analyzed to determine if there is a statistically relevant linear correlation exists between the detection rate of EV71 in mild cases and the proportion of severe cases among all HFMD patients. As the cases progressed from mild to severe to fatal, the likelihood of EV71 detection increased (25.78%, 52.20% and 84.18%, respectively). For all cases in the timeframe evaluated in this study, the presence of virus was detected in 63.21% of cases; among cases showing positivity for virus, EV71 infection accounted for 50.14%. These results provide evidence to support the observed higher morbidity and mortality associated with this outbreak and emphasizes the importance of early detection in order to implement necessary prevention measures to mitigate disease progression.