Mathematical modeling for selecting center locations for medical and health supplies reserve in Hainan Province.

OBJECTIVE: To explore how to choose the center locations to build the medical and health supplies reserve among many island towns. METHODS: The center locations were selected from 18 towns Hainan Province, it's maximum service range (distance) was required to reach the minimum, or to minimize. RESULTS: Three scenarios were considered, the center locations included only one town, two towns, three towns. By the use of graph theory and MATLAB programming, a mathematical model was established to obtain the shortest distance and the shortest path between arbitrary two towns. CONCLUSIONS: We find out the center sites under certain conditions, and determine the specific service ranges of the center sites.

[Application of propofol sedation in patients undergoing continuous venous-venous haemodiafiltration].

OBJECTIVE: To study the use of propofol sedation in patients undergoing continuous venous-venous haemodiafiltration (CVVHDF) and assess the curative effects. METHODS: A retrospective study was conducted. Data from 74 patients with continuous sedation of propofol in emergency intensive care unit (ICU) from April 2009 to June 2011 were analyzed. There were 26 cases suffering from acute renal failure in CVVHDF group and 48 critical cases in non-CVVHDF group. Propofol administration duration, dose, the clearance rate and the average recovery time in both groups were analyzed, and plasma concentrations of propofol at inflow side and outflow side of CVVHDF circuit in 26 patients with CVVHDF were determined. RESULTS: Compared with non-CVVHDF group, it took a longer administration time (298.37±28.73 hours vs. 173.44±17.27 hours, P<0.05) and higher dose (35.89±0.76 g vs. 21.82±0.62 g, P<0.05) in CVVHDF group. There were no statistical significances on clearance rate at 2, 6, 24 hours after administration (2 hours: 13.85±1.15 ml/min vs. 14.41±1.21 ml/min, 6 hours: 5.92±0.52 ml/min vs. 6.32±0.59 ml/min, 24 hours: 4.75±0.41 ml/min vs. 5.33±0.45 ml/min) and recovery time (8.89±1.46 minutes vs. 8.47±1.37 minutes) between CVVHDF and non-CVVHDF groups (all P>0.05). Plasma concentrations of propofol at inflow side and outflow side of CVVHDF circuit were not different after propofol administration in 26 CVVHDF patients. CONCLUSIONS: Compared with patients in non-CVVHDF group, the patients who received propofol in CVVHDF required higher total dosage and longer delivery time to maintain a good sedation. In both two groups clearance rate of propofol and maintenance of a stable blood concentration were the same. The use of a proper dose of propofol in CVVHDF did not affect wake up time of the patients, there were no complications.

Study of the hippocampus and the anterior cingulate gyrus by proton MR spectroscopy in patients with post-traumatic stress disorder.

OBJECTIVE: To explore the characteristics of metabolic changes in patients with post-traumatic stress disorder through 1H-MRS in neuroanatomical circuit comparing with age-matches controls. METHODS: Fifty patients with post-traumatic stress disorder and 50 gender-and age-matched normal controls were involved. The neurochemical abnormalities including the levels of choline (Cho)/creatine(Cr) and N-acetylaspartate (NAA)/Cr were measured respectively in hippocampus and the anterior cingulate gyrus with three-dimension 1H-proton spectroscopy(3D 1H-MRS). RESULTS: The values of NAA/Cr ratios in hippocampus and the anterior cingulate gyrus were significant lower in patients with post-traumatic stress disorder(1.71±0.32, left 1.58±0.29, right 1.55±0.31) than that in controls(2.24±0.41, left 1.98±0.27, right 2.02±0.36)(P<0.05), but the values of Cho/Cr in hippocampus(left 1.64±0.23, right 1.66±0.34) were no significant with that of controls (left 1.48±0.29, right 1.54±0.38). Values of Cho/Cr in cingulate gyrus were significant higher in post-traumatic stress disorder patients (1.88±0.44) than that in controls (1.37.±0.32) (P<0.05). CONCLUSIONS: The results indicate some special neurochemical and histological structure changes in post-traumatic stress disorder patients, which might occurre earlier in anterior cingulate gyrusthe than in hippocampus.

Nicotine promotes proliferation and collagen synthesis of chondrocytes isolated from normal human and osteoarthritis patients.

The aims of the study were to show the direct effect of nicotine with different concentrations (0, 25, 50, and 100 ng/ml) on chondrocytes isolated from normal human and osteoarthritis patients, respectively. Microscopic observation was performed during the culture with an inverted microscope. Methyl thiazolyl tetrazolium (MTT) assay method was adopted to observe the influence of nicotine on the proliferation of chondrocytes, and real-time PCR and ELISA were used to assay the mRNA and protein expression of type II collagen and aggrecan, respectively. We discovered that the OA chondrocytes were similar to fibroblasts in shape and grow slower than normal chondrocytes. The proliferation of the two kinds of chondrocytes was increased in a concentration-dependent manner and in a time-dependent manner (P<0.05). Also, we found that the mRNA level of type II collagen were upregulated under 25-100 ng/ml nicotine doses both in the two kinds of chondrocytes compared with control. The expression of protein levels of type II collagen were synthesized in line with the increase in mRNA. No effect was observed on aggrecan synthesis with any nicotine dose. We concluded that nicotine has the same effect on both chondrocytes, obtained either from osteoarthritis patients or from normal human, and the positive effect of smoking in OA may relate to the alteration in metabolism of chondrocytes.

Coccygectomy for stubborn coccydynia.

OBJECTIVE: To evaluate the preliminary clinical outcomes of coccygectomy in patients with coccydynia after a failure of conservative treatment. METHODS: From May 2002 to January 2010, 31 patients with coccydynia were treated by coccygectomy in our department after conservative measures had failed to produce significant relief. A questionnaire, which included the extent of relief in the painful area, improvement in quality of life, intensity of pain in the sitting position, and pain score during daily activities, was used to evaluate the results. RESULTS: All patients were followed up for 1 to 6 years (mean 3.3 years). The results were excellent in 20 patients (64.5%), good in 7 patients (22.6%), moderate in 3 patients (9.7%) and poor in 1 patient (3.2%). The excellent and good rates amounted to 87.1%. All patients except one had complete resolution of their symptoms and were subjectively highly satisfied with the outcomes of the surgery. Only 2 cases of superficial infection were observed postoperatively. CONCLUSION: Coccygectomy is a feasible management option for patients with coccygodynia that has no response to conservative treatments.