[Clinical effect of negative pressure wound therapy in emergency limb-salvage operation of destructive injury of limb].

Objective: To explore the clinical effect of negative pressure wound therapy (NPWT) in emergency limb-salvage operation of destructive injury of limb. Methods: From July 2014 to December 2017, 43 patients with destructive injury of limb in one side conformed to the inclusion criteria were admitted to our hospital. The patients were divided to NPWT group of 24 patients [ 21 males and 3 females, aged (38±10) years] and routine dressing change group of 19 patients [ 17 males and 2 females, aged (37±10) years] according to their treatment methods. After the emergency debridement, fracture external fixation, neurovascular exploration, and microsurgical repair were performed, NPWT were applied on wounds of patients in NPWT group and routine dressing change treatment on wounds of patients in routine dressing change group. On 7 to 10 days after the emergency operation, incidence of arterial embolism of patients in the two groups were calculated, and condition of wound infection of patients in the two groups were observed. Complete wound healing time and survival condition of limb were recorded. Data were processed with independent sample t test or chi-square test. Results: Incidence of arterial embolism of patients in NPWT group on 7 to 10 days after the emergency operation was 6.67% (3/45), which was close to 5.56% (2/36) of patients in routine dressing change group (χ(2)=0.043, P>0.05). There was 1 patient with wound infection in NPWT group on 7 to 10 days after the emergency operation, obviously less than 6 patients in routine dressing change group (χ(2)=5.847, P<0.05). Complete wound healing time of patients in NPWT group was (30±4) d, significantly shorter than (36±8) d of patients in routine dressing change group (t=2.813, P<0.01). Limbs of 24 patients in NPWT group survived, which was close to 18 patients in routine dressing change group (χ(2)=1.293, P>0.05). Conclusions: NPWT can significantly reduce tthe wound infection rate and shorten the time of wound healing of limb with destructive injury after emergency operation, which is worthy of popularization in clinic.

Fabrication of large scale nanostructures based on a modified atomic force microscope nanomechanical machining system.

The atomic force microscope (AFM) tip-based nanomechanical machining has been demonstrated to be a powerful tool for fabricating complex 2D∕3D nanostructures. But the machining scale is very small, which holds back this technique severely. How to enlarge the machining scale is always a major concern for the researches. In the present study, a modified AFM tip-based nanomechanical machining system is established through combination of a high precision X-Y stage with the moving range of 100 mm × 100 mm and a commercial AFM in order to enlarge the machining scale. It is found that the tracing property of the AFM system is feasible for large scale machining by controlling the constant normal load. Effects of the machining parameters including the machining direction and the tip geometry on the uniform machined depth with a large scale are evaluated. Consequently, a new tip trace and an increasing load scheme are presented to achieve a uniform machined depth. Finally, a polymer nanoline array with the dimensions of 1 mm × 0.7 mm, the line density of 1000 lines/mm and the average machined depth of 150 nm, and a 20 × 20 polymer square holes array with the scale of 380 µm × 380 µm and the average machined depth of 250 nm are machined successfully. The uniform of the machined depths for all the nanostructures is acceptable. Therefore, it is verified that the AFM tip-based nanomechanical machining method can be used to machine millimeter scale nanostructures.

Nitrification-denitrification via nitrite for nitrogen removal from high nitrogen soybean wastewater with on-line fuzzy control.

This study is to demonstrate the performance of a new technology for complete nitrogen removal from soybean wastewater with high nitrogen concentrations. Nitrification-denitrification via nitrite was performed in three kinds of operating condition, i.e. nitrification-denitrification via nitrite under traditional SBR process, nitrification-denitrification via nitrite by alternating oxic/anoxic under fixed-time control and nitrification-denitrification via nitrite by alternating oxic/anoxic under on-line fuzzy control. The best one is nitrification-denitrification via nitrite by alternating oxic/anoxic under on-line fuzzy control. It not only improves both nitrification and denitrification rates and decreases total reaction time, but also saves the amount of added carbon source and alkalinity. In addition, reaction time can be shortened and operation cost can be saved by using real-time fuzzy control aeration and mixing time. So this method enhances the efficiency and the stability of nitrogen removal, and reduces operating costs and construction investment in the process of wastewater treatment.

Effects of reduced sympathetic activity on myocardial metaiodobenzylguanidine (MIBG) washout.

1. Increase in myocardial sympathetic activity contributes markedly to the pathophysiology of conditions such as congestive heart failure and is also associated with myocardial infarction. However, measurement of myocardial sympathetic activity in vivo is difficult. 2. The present study assesses the effectiveness of metaiodobenzylguanidine (MIBG) imaging to characterize modulation of sympathetic activity, as induced by dexmedetomidine, a highly specific alpha-2 adrenoceptor agonist. 3. We imaged washout of [125I]-MIBG from rabbit heart before and during two consecutive 45-min intravenous infusions of dexmedetomidine (10 microg kg(-1) followed by 16 microg kg(-1)) (n=9) or of saline (n=9). 4. Heart rate (HR), and mean blood pressure (BP) were measured before and at the end of each study period. Plasma noradrenaline (NA) was measured before and after study drug infusion. The hearts were then excised and biopsied for MIBG tissue concentration [MIBG] (% kg-dose g(-1)). 5. Relative to saline controls, dexmedetomidine significantly decreased HR, BP, plasma NA and MIBG washout. There was an inverse correlation between MIBG washout and residual [MIBG] in the myocardium (r= -0.75, P < 0.01). 6. These data suggest that a reduction of sympathetic nervous system activity causes a decrease in myocardial MIBG washout in vivo in rabbits, and confirms the usefulness of MIBG scintigraphy as a non-invasive tool to measure changes in myocardial sympathetic activity.

Reperfused rat myocardium subjected to various durations of ischemia: estimation of the distribution volume of contrast material with echo-planar MR imaging.

PURPOSE: To estimate and compare the fractional distribution volume (fDV) of gadodiamide injection and technetium 99m-diethylenetriaminepentaacetic acid (DTPA) in the reperfused myocardium of rat hearts subjected to various durations of ischemia. MATERIALS AND METHODS: Magnetic resonance (MR) imaging and autoradiography were performed in rats subjected to 20, 30, 40, or 60 minutes of regional ischemia followed by 1 hour of reperfusion. The fDVs of gadodiamide injection and (99m)Tc-DTPA were measured and compared by using inversion-recovery echo-planar imaging and autoradiographic phosphor imaging, respectively. RESULTS: The mean fDV of both tracers (gadodiamide and (99m)Tc-DTPA) in normal myocardium was 18% +/- 1, whereas that in the entire area at risk increased significantly (P <.05) with 20, 30, 40, and 60 minutes of ischemia to 32% +/- 1, 57% +/- 4, 66% +/- 2, and 68% +/- 2, respectively. The fDV was significantly (P <.05) greater in the core of infarction-78% +/- 4, 89% +/- 5, and 88% +/- 5 with 30, 40, and 60 minutes of ischemia, respectively-than in the normal myocardium or in the area at risk. CONCLUSION: The fDV of MR contrast material in the periinfarcted rim was significantly (P <. 05) greater than that in the normal myocardium, but significantly less than that in the core of infarcted myocardium.

Heterogeneous sympathetic innervation influences local myocardial repolarization in normally perfused rabbit hearts.

BACKGROUND: Heterogeneity of sympathetic innervation is thought to contribute to the potential for fatal arrhythmia. However, little is known about the effects of heterogeneous innervation on repolarization. METHODS AND RESULTS: To assess this relationship, we measured activation recovery intervals (ARIs) from 64 epicardial sites in 11 rabbits studied 2 weeks after regional denervation produced by phenol and 4 sham-operated rabbits. ARI results were compared with the distribution of sympathetic innervation measured from 3D reconstructions of serial autoradiographs of [(125)I]metaiodobenzylguanidine and (99m)Tc-sestamibi. ARIs were recorded during baseline sinus rhythm, norepinephrine (NE) infusion (0.1 microg. kg(-1). min(-1)), and left stellate ganglion stimulation (SS). NE shortened ARI in 98% of electrodes in the denervated region. The degree of ARI shortening and dispersion increased (P<0.001 and P<0.01, respectively) as denervation became more severe. SS shortened ARI in 30% of electrodes in the denervated area, with increased shortening and dispersion related to increased severity of denervation (P<0.01). SS prolonged ARI in 70% of electrodes in the denervated area, with no correlation with severity of denervation. CONCLUSIONS: The magnitude and dispersion of local repolarization responses are related to the severity of denervation, as well as the type of stimulation: neural (SS) versus humoral (NE). The differences may relate to the concentration of NE released.

Measurement of the distribution volume of gadopentetate dimeglumine at echo-planar MR imaging to quantify myocardial infarction: comparison with 99mTc-DTPA autoradiography in rats.

PURPOSE: To measure the fractional distribution volume of gadopentetate dimeglumine in normal and reperfused infarcted myocardium at magnetic resonance (MR) imaging by using the fractional distribution volume of technetium 99m-diethylenetriaminepentaacetic acid (DTPA) as an independent reference. MATERIALS AND METHODS: Rats were subjected to 1 hour of coronary artery occlusion and 1 hour of reperfusion before inversion-recovery echo-planar imaging or autoradiography. Regional change in relaxation rate (delta R1) ratios for myocardium over blood were compared with radioactivity ratios for myocardium over blood after the injection of 99mTc-DTPA. RESULTS: Both delta R1 and radioactivity ratios demonstrated equilibrium distribution and hence represent partition coefficients (lambda). The fractional distribution volumes were greater in infarcted myocardium (0.90 +/- 0.05 for gadopentetate dimeglumine and 0.89 +/- 0.04 for 99mTc-DTPA) than in normal myocardium (0.23 +/- 0.02 for gadopentetate dimeglumine and 0.16 +/- 0.01 for 99mTc-DTPA). Area at risk at autoradiography was not significantly different from that at histomorphometry. The infarction size defined by using triphenyltetrazolium chloride was 13% +/- 4 smaller than that defined by using autoradiography. CONCLUSION: The fractional distribution volumes of gadopentetate dimeglumine and 99mTc-DTPA are similar and indicate extracellular distribution in normal myocardium and intracellular as well as extracellular distribution in reperfused infarction. Because the failure of cells to exclude these agents is indicative of necrosis, contrast medium-enhanced MR imaging may be useful to quantify myocardial infarction.

Microvascular injury in reperfused infarcted myocardium: noninvasive assessment with contrast-enhanced echoplanar magnetic resonance imaging.

OBJECTIVES: The purpose of this study was to measure the accumulation of labeled albumin and to visualize its distribution pattern in reperfused infarcted myocardium as a function of time between onset of reperfusion and administration of the tracer. BACKGROUND: Myocardial microvascular injury leads to leakage of albumin from the intravascular space. Quantitative measurements of GdDTPA-albumin with inversion recovery echoplanar imaging (IR-EPI) may allow noninvasive monitoring of microvascular injury. METHODS: After 1 h of coronary artery occlusion, 56 rats were injected with GdDTPA-albumin or 123I-GdDTPA-albumin either immediately before reperfusion or 1/2, 1 or 24 h after reperfusion. GdDTPA-albumin in blood, normal myocardium and reperfused infarction was dynamically measured with IR-EPI during 1 h postinjection (PI). Autoradiograms were obtained at 15 min PI. Accumulation of labeled albumin in myocardium was expressed as the ratio of myocardial to blood content. RESULTS: In normal myocardium, the ratio of changes of relaxation rate-ratio (deltaR1-ratio) was 0.12+/-0.01 and did not change over 1 h. In reperfused infarction, however, the deltaR1-ratio increased after administration. Animals given GdDTPA-albumin before reperfusion exhibited fastest accumulation (deltaR1-ratio 15 min PI: 0.56+/-0.03) and essentially homogeneous distribution. The accumulation was slower when administered at 1/2, 1 and 24 h after reperfusion (deltaR1-ratios 15 min PI: 0.39+/-0.03; 0.31+/-0.04; 0.16+/-0.01; p < 0.001 compared to administration before reperfusion). Moreover, the tracer accumulated predominantly in the periphery of the injury zone. CONCLUSIONS: Amount and distribution pattern of labeled albumin in reperfused infarction are modulated by duration of reperfusion. The accumulation of GdDTPA-albumin can be quantified by IR-EPI. Thus, IR-EPI may be useful to noninvasively monitor myocardial microvascular injury in reperfused infarction.

[A statistical comparison study of glaucoma in the Third Affiliated Hospital of China Medical College and Kyushu University].

We classified 331 glaucoma patients who visited the eye clinic of the Third Affiliated Hospital of China Medical College during the 2 year period from January 1985 to December 1986 according to the type of glaucoma. The results were compared with those obtained from 275 glaucoma patients who visited the eye clinic of Kyushu University during an overlapping period of 2 years, from January 1986 to December 1987. Patients with glaucoma were found to comprise 1.5% of the 22,869 outpatients in the Third Affiliated Hospital of China Medical College, and 1.8% of the 15,585 outpatients in Kyushu University. The distribution of various types was as follows: primary angle closure glaucoma (76.4%), primary open angle glaucoma (4.8%), secondary glaucoma (11.8%), exfoliation glaucoma (0) and congenital glaucoma (5.7%) in the Third Affiliated Hospital of China Medical College, and primary angle closure glaucoma (34.5%), primary open angle glaucoma (12.7%), secondary glaucoma (22.2%), exfoliation glaucoma (14.9%) and congenital glaucoma (10.9%) in Kyushu University. The present results suggest that the incidence of primary angle closure glaucoma in China is higher than in Japan, and that the incidence of primary angle closure glaucoma is higher than that of primary open angle glaucoma in these two countries. It is of interest that the high incidence of primary angle closure glaucoma in China and Japan coincides with the study in Canadian Eskimos. The incidences of secondary glaucoma and exfoliation glaucoma in Japan are higher than in China. This might be due to differences in diagnostic facilities in the two countries.

[The changes in beta-adrenergic receptors and cyclic AMP levels of lymphocytes in patients with COPD].

The maximal binding capacity (Bmax) of beta-adrenergic receptors and the production of intracellular cAMP in response to isoproterenol in peripheral blood lymphocytes were measured by radioligand binding assay and competitive protein-binding method respectively. Two groups of COPD patients (19 cases was at the onset of disease, 17 cases was stable) were investigated and 20 normal subjects as control. The amount of Bmax at the onset of COPD (208.55 +/- 14.14fmol/10(8)cells) and during the stable stage (299.25 +/- 13.90fmol/10(6)cells) was significantly lower than that in normal subjects (338.35 +/- 12.22fmol/10(8)cells) (P less than 0.01). There were also obvious differences in amounts of Bmax between two groups of COPD (P less than 0.01). The changes of intracellular cAMP were similar to the results of Bmax. This study indicated that beta-adrenergic receptor function is attenuated in COPD patients especially at the onset of the disease. The possible mechanism of the reduction of beta-adrenergic receptor and the clinical significance in the use of beta-adrenoceptor agonist were discussed.