Differentiation Between Amyotrophic Lateral Sclerosis and Mimics Using Quantitative Analysis of Fsciculation with Muscle Ultrasound / 中国医学科学杂志(英文版)

Objective To determine the diagnostic accuracy of the intensity of fasciculation evaluated by muscle ultrasound in the differential diagnosis of amyotrophic lateral sclerosis (ALS). Methods We prospectively recruited patients who had ALS and neuropathy-radiculopathy attending Peking Union Medical College Hospital from 2017 to 2020. Healthy adults from a community were recruited as healthy controls. Muscle strength was assessed using the Medical Research Council (MRC) scale. At the first visit to the hospital, patients were assessed for maximal grade of fasciculations, total fasciculation score, and fasciculation grade in 16 muscle groups of bilateral upper and lower limbs using ultrasonography. The sensitivity and specificity of maximal grade of fasciculations, total fasciculation score, and fasciculation grade for the diagnosis of ALS were assessed by receiver operating characteristic analyses. Results The percentage of limb muscles with a maximal fasciculation grade higher than grade 2 in ALS patients and neuropathy-radiculopathy patients was 84.9% and 9.8%, respectively (χ2 = 172.436, P < 0.01). Of the 16 limb muscles detected, the total fasciculation score [median (interquartile range)] was 29 (15, 41) in ALS patients and 3 (0, 8) in neuropathy-radiculopathy patients (Z = 9.642, P < 0.001). Remarkable fasciculations were seen in ALS patients whose muscles with a MRC score ranging from 2 to 4, followed by patients with MRC score 5, and then in those with MRC score 0 and 1. The sensitivity and specificity of total fasciculation score for diagnosis of ALS were 80.6% and 93.4%, respectively (cut-off value 14). In patients with ALS, for muscles with MRC score 4 and 5, the percentage of muscles with fasciculation grades ≥ 3 was 42.3% and 24.1% respectively, while in neuropathy-radiculopathy patients, the percentage for muscles with MRC score 4 and 5 was only 1.7% and 0, respectively. Conclusion A combined analysis of fasciculation intensity and MRC score of the limb muscles may be helpful for differential diagnosis of ALS.

Comedications and potential drug-drug interactions with direct-acting antivirals in hepatitis C patients on hemodialysis

Background/Aims@#Direct‐acting antivirals (DAAs) have been approved for hepatitis C virus (HCV) treatment in patients with end-stage renal disease (ESRD) on hemodialysis. Nevertheless, the complicated comedications and their potential drug-drug interactions (DDIs) with DAAs might limit clinical practice in this special population. @*Methods@#The number, class, and characteristics of comedications and their potential DDIs with five DAA regimens were analyzed among HCV-viremic patients from 23 hemodialysis centers in Taiwan. @*Results@#Of 2,015 hemodialysis patients screened in 2019, 169 patients seropositive for HCV RNA were enrolled (mean age, 65.6 years; median duration of hemodialysis, 5.8 years). All patients received at least one comedication (median number, 6; mean class number, 3.4). The most common comedication classes were ESRD-associated medications (94.1%), cardiovascular drugs (69.8%) and antidiabetic drugs (43.2%). ESRD-associated medications were excluded from DDI analysis. Sofosbuvir/velpatasvir/voxilaprevir had the highest frequency of potential contraindicated DDIs (red, 5.6%), followed by glecaprevir/pibrentasvir (4.0%), sofosbuvir/ledipasvir (1.3%), sofosbuvir/velpatasvir (1.3%), and elbasvir/grazoprevir (0.3%). For potentially significant DDIs (orange, requiring close monitoring or dose adjustments), sofosbuvir/velpatasvir/voxilaprevir had the highest frequency (19.9%), followed by sofosbuvir/ledipasvir (18.2%), glecaprevir/pibrentasvir (12.6%), sofosbuvir/velpatasvir (12.6%), and elbasvir/grazoprevir (7.3%). Overall, lipid-lowering agents were the most common comedication class with red-category DDIs to all DAA regimens (n=62), followed by cardiovascular agents (n=15), and central nervous system agents (n=10). @*Conclusions@#HCV-viremic patients on hemodialysis had a very high prevalence of comedications with a broad spectrum, which had varied DDIs with currently available DAA regimens. Elbasvir/grazoprevir had the fewest potential DDIs, and sofosbuvir/velpatasvir/voxilaprevir had the most potential DDIs.

Clinical Characteristics of Autoimmune Disease with Dual Seropositive Antibodies of Leucine-rich Glioma Inactivated 1 and Contactin-associated Protein 2 / 中国医学科学院学报

Objective To explore the clinical characteristics of autoimmune disease with dual seropositive antibodies of leucine-rich glioma inactivated 1(LGI1)and contactin-associated protein 2(Caspr2).Methods The clinical data of seven patients with dual seropositive LGI1 and Caspr2 antibodies who were admitted to the Neurology Department of Peking Union Medical College Hospital from July 2014 to December 2017 were retrospectively analyzed.Results Central,peripheral and autonomic nervous systems were all involved in the seven cases;100%(7/7)presented with insomnia,myokymia,neuropahic pain and hyperhydrosis;71%(5/7)showed memory decline or psychiatric and behavioral symptoms;57%(4/7)had urinary hesitation or constipation;and 43%(3/7)had seizure.Electromyography showed 100%(6/6) of the patients had prolonged afterdischarges following normal M waves and/or abnormal spontaneous firing.Electroencephalography revealed slow waves or basic rhythm slowing in 71%(5/7)of patients.Electrocardiography showed sinus tachycardia,axis deviation,and prolonged QT intervals in 71%(5/7)of patients.One patient died from arrhythmia before immunotherapy.One died from pulmonary infection after immunotherapy.Improvement with immunotherapy was documented in the other five cases.No relapse was noted during the 1-2-year follow-up.Conclusions Autoimmune disease with dual seropositive antibodies of LGI1 and Caspr2 can diffusely affect the central,peripheral,and autonomic nervous systems.The possibility of this disease should be considered in patients with acute and subacute onset of neuropsychiatric symptoms,especially in patients with accompanying insomnia,myokymia,and hyperhydrosis.

Effect of PASMC apoptosis on reversal of hypoxic pulmonary arterial remodeling during reoxygenation and its related molecular mechanism / 中国病理生理杂志

AIM: To explore the effect of pulmonary arterial smooth muscle cell (PASMC) apoptosis on the reversal of hypoxic pulmonary arterial remodeling during reoxygenation and its possible mechanism.METHODS: Male SD rats (n=24) were randomly divided into normoxia for 4 weeks group, hypoxia for 4 weeks group, reoxygenation for 1 week after hypoxia for 4 weeks group and reoxygenation for 6 weeks after hypoxia for 4 weeks group.Right ventricular systolic pressure (RVSP), right ventricular hypertrophy index, pulmonary arterial medial thickness (MT) and medial area (MA) as well as autophagy and apoptosis in the pulmonary arterial medial layer were examined during hypoxia-reoxygenation.The rat primary PASMCs were divided into normoxia for 48 h group, hypoxia for 48 h group, reoxygenation for 24 h after hypoxia for 48 h group and normoxia for 72 h group to explore the changes of PASMC autophagy and apoptosis following hypoxia-reoxygenation.Finally, primary PASMCs were divided into normoxia for 72 h group, reoxygenation for 24 h after hypoxia for 48 h group and reoxygenation for 24 h after hypoxia for 48 h + chloroquine (inhibitor of autophagy) group to investigate the effect of PASMC autophagy during hypoxia on the apoptosis during reoxygenation.RESULTS: After hypoxia for 4 weeks, the RVSP, during right ventricular hypertrophy index, MT and MA increased significantly compared with normoxia group (P<0.05), and gradually decreased during reoxygenation.The expression of LC3 in the pulmonary arterial medial layer increased evidently after hypoxia and gradually reversed during reoxygenation.Moreover, the P62 and cleaved caspase-3 expression decreased after hypoxia compared with normoxia group, and increased markedly following reoxyge-nation.The expression of cleaved caspase-3/PARP in rat primary PASMCs decreased significantly under hypoxia (P<0.05), and increased evidently during reoxygenation.The expression of P62 and LC3-II decreased markedly under hypoxia (P<0.05).After inhibition of PASMC autophagy under hypoxia, the expression of cleaved caspase-3/PARP decreased remarkably during reoxygenation (P<0.05).CONCLUSION: The PASMC apoptosis participates in the reversal of hypoxic pulmonary arterial remodeling, and the PASMC autophagy under hypoxia might facilitate its apoptosis during reoxygenation.

Quantitating Changes in Jitter and Spike Number Using Concentric Needle Electrodes in Amyotrophic Lateral Sclerosis Patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Single-fiber electromyography (SFEMG) has been suggested as a quantitative method for supporting chronic partial denervation in amyotrophic lateral sclerosis (ALS) by the revised EI Escorial criteria. Although concentric needle (CN) electrodes have been used to assess jitter in myasthenia gravis patients and healthy controls, there are few reports using CN electrodes to assess motor unit instability and denervation in neurogenic diseases. The aim of this study was to determine whether quantitative changes in jitter and spike number using CN electrodes could be used for ALS studies.</p><p><b>METHODS</b>Twenty-seven healthy controls and 23 ALS patients were studied using both CN and single-fiber needle (SFN) electrodes on the extensor digitorum communis muscle with an SFEMG program. The SFN-jitter and SFN-fiber density data were measured using SFN electrodes. The CN-jitter and spike number were measured using CN electrodes.</p><p><b>RESULTS</b>The mean CN-jitter was significantly increased in ALS patients (47.3 ± 17.0 μs) than in healthy controls (27.4 ± 3.3 μs) (P < 0.001). Besides, the mean spike number was significantly increased in ALS patients (2.5 ± 0.5) than in healthy controls (1.7 ± 0.3) (P < 0.001). The sensitivity and specificity in the diagnosis of ALS were 82.6% and 92.6% for CN-jitter (cut-off value: 32 μs), and 91.3% and 96.3% for the spike number (cut-off value: 2.0), respectively. There was no significant difference between the SFN-jitter and CN-jitter in ALS patients; meanwhile, there was no significant difference between the SFN-jitter and CN-jitter in healthy controls.</p><p><b>CONCLUSION</b>CN-jitter and spike number could be used to quantitatively evaluate changes due to denervation-reinnervation in ALS.</p>

Single-fiber Electromyography in the Extensor Digitorum Communis for the Predictive Prognosis of Ocular Myasthenia Gravis: A Retrospective Study of 102 Cases / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Single-fiber electromyography (SFEMG) abnormality in the extensor digitorum communis (EDC) was reported in ocular myasthenia gravis (OMG), which indicated subclinical involvement beyond extraocular muscles in OMG patients. The relationship between the abnormal findings of SFEMG in EDC and the probability for OMG to develop generalized myasthenia gravis (GMG) is unknown. This retrospective study aimed to determine the predictive value of abnormality of SFEMG in EDC of OMG patients.</p><p><b>METHODS</b>One-hundred and two OMG patients underwent standard clinical diagnosis process and SFEMG test in EDC muscle when diagnosed and were clinically followed up for 5 years. The SFEMG data were compared between different clinical groups according to thymus status, onset age, and different outcome of OMG developing. Chances of progressing to GMG were compared between two different groups according to SFEMG and repetitive nerve stimulation (RNS) results, acetylcholine receptor antibody (AchRAb) titer, thymus status, and onset age.</p><p><b>RESULTS</b>Abnormal SFEMG results were observed in 84 (82.4%) patients. The mean jitter, percentage of jitter >55 μs (%), and blocking were higher in OMG patients than in healthy volunteers. There were no statistical differences in jitter analysis between thymoma group and non-thymoma group (P = 0.65), or between the later OMG group and the later GMG group (P = 0.31), including mean jitter, percentage of jitter >55 μs (%), and blocking. Elderly group (≥45 years old) had a higher mean jitter than younger group (t = 2.235, P = 0.028). Total 55 OMG developed GMG, including 47 in abnormal SFEMG group while 8 in normal SFEMG group. There was no statistical difference in the conversion rates between the two groups (χ2 = 0.790, P = 0.140). RNS abnormality, AchRab titer, or onset age had no correlation with OMG prognosis (P = 0.150, 0.070, 0.120, respectively) while thymoma did (χ2 = 0.510, P = 0.020).</p><p><b>CONCLUSION</b>SFEMG test in the EDC showed high abnormality in OMG, suggesting subclinical involvement other than extraocular muscles. Nevertheless, the abnormal jitter analysis did not predict the prognosis of OMG according to clinical follow-up.</p>

Congenital dyserythropoietic anemia type II with novel mutations in SEC23B and HFE2 genes: a Chinese family survey / 中华血液学杂志

<p><b>OBJECTIVE</b>To report novel mutations SEC23B gene in congenital dyserythropoietic anemia (CDA).</p><p><b>METHODS</b>By direct sequencing method, we sequenced CDAN1 and SEC23B genes in a Chinese CDA II patient, presented with chronic fatigue and dark urine, as well as his family members. Serum hepcidin was assayed by mass spectrometry.</p><p><b>RESULTS</b>We found a c.71G>A mutation and a c.74C> A mutation in the patient. In addition, a heterozygous c.55A>G mutation of HFE2 gene was found in some family members. The level of serum hepcidin of the patient was below the detection limit (<1 nmol/L).</p><p><b>CONCLUSION</b>Contrary with what have been reported previously in the Europe, especially in the Italy, the gene mutations identified in this case was different and novel. The two novel mutations contribute to the diagnosis of CDAII and are the first report in East Asian CDAII patients.</p>

Effects of advanced glycation end products and its receptor on oxidative stress in diabetic wounds / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the accumulation of advanced glycation end products (AGE) and the inflammatory response of skin and wound in diabetic patients, and to analyze their relationship in vitro.</p><p><b>METHODS</b>Histological staining and immunohistochemical staining was respectively performed on skin and wound tissue specimens collected from 10 patients with Type II diabetes mellitus (diabetes group) and 12 non-diabetic patients with skin injury (control group) to observe the arrangement of collagen and the distribution of inflammatory cells, and to determine the expression levels of AGE and its receptor (RAGE). Malondialdehyde (MDA) levels in skin and wound tissue homogenates were assayed by enzyme-linked immunosorbent assay. In vitro, human neutrophils were isolated and treated with RPMI-1640 culture medium or that containing AGE-human serum albumin in the concentration of 0.315, 0.625, 1.250 mg/mL, and they were identified as normal control (NC) group, low concentration (L) group, moderate concentration (M) group, and high concentration (H) group. Cell viability in each group was determined by MTT colorimetric assay, and the reactive oxygen species (ROS) in cell was measured with 2', 7'-dichlorofluorescein-diacetate. Data were processed with t test.</p><p><b>RESULTS</b>Compared with those of skin in control group, collagens of skin tissues in diabetes group atrophied and disorderly arranged. Inflammatory cells in wounds in diabetes group were dispersed, in which collagens arranged loosely and irregularly, as compared with those of wounds in control group. Expression levels of AGE and RAGE of skin in diabetes group were higher than those in control group. In diabetes and control groups, especially in diabetes group, the numbers of RAGE-positive cells in wound tissue were more than those in skin tissue. Large amount of inflammatory cells with positive expression of RAGE were observed in diabetes group. MDA level of skin and wound tissue in diabetes group was respectively (6.3 ± 1.0), (7.1 ± 2.4) nmol per milligram protein, which were obviously higher than those in control group [(2.9 ± 1.0), (3.6 ± 1.4) nmol per milligram protein, with t value respectively 8.017, 4.349, P < 0.05 or P < 0.01]. Cell viability and ROS levels in neutrophils were increased in L, M, and H groups [(59 ± 8)%, (77 ± 5)%, (67 ± 6)% and 1.67 ± 0.14, 2.13 ± 0.17, 3.48 ± 0.48] as compared with those in NC group [(34 ± 5)% and 0.58 ± 0.06, with t value respectively 7.195, 14.890, 11.130 and 20.195, 24.905, 16.864, P < 0.05 or P < 0.01].</p><p><b>CONCLUSIONS</b>Abnormal oxidative stress in diabetic skin leads to an atypical origin of wound repair. AGE-RAGE effect is a critical mediator for oxidative stress in diabetic wound tissue during wound healing.</p>

Relationship between cutaneous glycometabolic disorders and cutaneous neuropathy in diabetic rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To analyze the relationship between cutaneous glycometabolic disorders and cutaneous neuropathy in diabetic rats, and to look for the mechanism of neuropathy and impaired wound healing.</p><p><b>METHODS</b>Eighty male SD rats were randomly divided into the normal control group (NC, n = 20), diabetic group (D, n = 20), aminoguanidine-interfered group (AI, n = 20), and insulin-interfered group (II, n = 20) by drawing lots. Diabetes was reproduced in rats of D, AI, and II groups with intraperitoneal injection of streptozotocin (STZ). Then, rats in AI group were fed with 100 mg×kg(-1)×d(-1) aminoguanidine, while rats in II group were subcutaneously injected with insulin for satisfactory control of blood glucose. Changes in mechanical and heat pain thresholds of pad of hind limb were measured at post injection week (PIW) 2, 4, 8. Skin specimens were collected during PIW 2-8 from pads for determination of contents of glucose, advanced glycation end product (AGE), substance P (SP), calcitonin gene-related peptide (CGRP), and observation of distribution and ultrastructure of skin nerve fibers. Data were processed with t test.</p><p><b>RESULTS</b>The mechanical and heat pain thresholds in D group at PIW 2 [(6.3 ± 1.5) g, (6.0 ± 0.9) s, respectively ] were obviously lower than those in NC group [(13.0 ± 3.2) g, (10.3 ± 1.2) s, with t value respectively 2.71, 3.42, P values all below 0.05]. Contents of glucose and AGE in skin tissue in D group were significantly increased when compared with those in NC group, especially at PIW 8 [(2.85 ± 0.33) mg/g, (31.7 ± 3.2) U/mg of hydroxyproline vs. (0.82 ± 0.22) mg/g, (22.2 ± 1.9) U/mg of hydroxyproline, with t value respectively 1.65, 6.47, P values all below 0.01]. The myelinated nerve fibers were edematous and degenerated, with axons compressed, while the unmyelinated nerve fibers were vacuolated, with microfilament and microtubule disorderly arranged. Content of SP in skin tissue in D group was lower as compared with that in NC group, especially at PIW 2 [(16.8 ± 3.4) pg/g vs. (28.5 ± 5.0) pg/g, t = 2.42, P < 0.01]. There was no obvious difference in content of CGRP between NC and D groups, and also in content of glucose in skin between D and AI groups. Compared with those in D group, content of AGE in AI group at PIW 8 was decreased markedly [(27.2 ± 1.4) U/mg of hydroxyproline, t = 3.38, P < 0.05]; contents of glucose and AGE in II group at PIW 8 were significantly decreased [(1.42 ± 0.38) mg/g, (23.6 ± 1.3) U/mg of hydroxyproline, with t value respectively 1.74, 8.17, P < 0.05 or P < 0.01]. Compared with that in D group, contents of SP in AI and II groups were increased, with a delay in time of trough value. Content of CGRP showed no obvious difference among D, AI, and II groups.</p><p><b>CONCLUSIONS</b>High glucose and accumulation of AGE are key mediators of cutaneous neuropathy and impaired wound healing in diabetes mellitus, which confirms that diabetic wound takes an atypical footing during wound repairing. Aminoguanidine and insulin can reduce contents of glucose and AGE in diabetic skin tissue, and ameliorate diabetic cutaneous neuropathy.</p>

Effect of topical application of aminoguanidine cream on skin tissue of rats with diabetes / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of aminoguanidine cream on the proliferation of keratinocytes (KC), content of advanced glycosylation end products (AGE) and oxidative stress in skin tissue of rats with diabetes.</p><p><b>METHODS</b>Stearic acid, liquid paraffin, vaseline, lanolin, isopropyl myristate fat, glycerol, 50 g/L alcohol paraben, aminoguanidine hydrochloride etc. were mixed in certain proportion to make aminoguanidine cream, and cream without aminoguanidine was used as matrix. The dorsal skin of normal rats were harvested and treated by aminoguanidine cream with dose of 5, 10 g/L, or 5 g/L together with 10 g/L azone. The transdermal effect was respectively measured at post treatment hour 2, 4, 7, 10, 12, 24. Thirty SD rats were divided into normal control (NC, n = 6), diabetes (D, n = 8), aminoguanidine cream-interfered (AI, n = 8), matrix cream-interfered groups (MI, n = 8) according to the random number table. Diabetes was reproduced by intraperitoneal injection of STZ (65 mg/kg) in rats of D, AI, and MI groups, and rats in NC group were injected with 0.05 mmol/L citrate buffer as control. One week later, dorsal skin of rats in AI and MI groups were respectively treated with 10 g/L aminoguanidine cream and matrix cream by external use for 4 weeks. AGE content was determined with fluorescence detection from skin collagen extract. KC cell cycle was detected by flow cytometry. Skin tissue specimens were obtained for determination of levels of superoxide dismutase (SOD), malondialdehyde (MDA), myeloperoxidase (MPO), and total antioxidant capacity. Data were processed with t test.</p><p><b>RESULTS</b>Transdermal effect of aminoguanidine cream with dose of 10 g/L was better than that with 5 g/L or 5 g/L + 10 g/L azone cream. One rat was not induced successfully in MI group. Four weeks after model reproduction, 4 rats died in D group and 1 rat died in AI group. The AGE content in D group was obviously higher than that in NC group [(36.8 +/- 2.6), (24.6 +/- 2.7) U per milligram hydroxyproline, respectively, t = 7.2, P < 0.01], and that in AI group [(28.6 +/- 3.7) U per milligram hydroxyproline] was also lower as compared with that in D group (t = -3.9, P < 0.05). There was no significant difference in AGE content between MI [(32.2 +/- 5.2) U per milligram hydroxyproline] and D groups (t = 1.6, P > 0.05). The percentage of KC in S phase was obviously lower in D group than in NC group [(5.3 +/- 0.6)%, (7.6 +/- 0.9)%, respectively, t = 4.50, P < 0.01], while that in MI group [(9.2 +/- 1.5)%] was higher as compared with that in D group ( t = 4.90, P < 0.01). It was more higher in AI group than in D group on KC percentage in S and G2/M phase (with t value respectively 6.80, 3.17, P values all below 0.01). The oxidative stress indexes of skin tissue in D group were all higher than those in NC group, in which levels of MPO and SOD showed statistical difference (with t value respectively 4.4, 3.7, P values all below 0.05). The oxidative stress indexes were all lower in AI group than in D group, especially in SOD level (t = -1.4, P < 0.05). Levels of MAD, MPO in MI group were significantly lower than those in D group (with t value respectively 2.6, 2.9, P values all below 0.05).</p><p><b>CONCLUSIONS</b>Aminoguanidine cream can promote KC proliferation and appropriately reduce oxidative stress through inhibiting AGE formation to a certain extent in skin tissue of rats with diabetes. Signal use of matrix cream can also reduce oxidative stress in skin tissue of rats with diabetes.</p>

Finite element study on knee injuries in the parachute landing / 医用生物力学

Objective To numerically simulate the half squat parachute landing and analyze the mechanism of knee injuries with the finite element method based on the data of the simulated parachute landing experiment. Method The half squat parachuting experiment was performed by 16 healthy volunteers. The heights of simulated landing were 0.32 m, 0.52 m and 0.72 m respectively. A three dimensional finite element model of human knee joint was developed based on magnetic resonance images. The kinematical data of the knee and the data of the reaction force obtained by experiments were used to make a numerical simulation of the parachute landing process. Results The stress level of the knee increased with the increase of the height. The lateral meniscus and cartilage suffered greater loads than the medial ones. Obvious stress concentrations occurred in the anterior cruciate ligament and the medial collateral ligament when the knee flexion degree reached the peak value. Conclusions The severe impact in parachute landing is the direct cause of injuries in parachute landing. The lateral cartilage and meniscus are more likely to be injured, and the anterior cruciate ligament and the medial collateral ligament are easier to tear when the knee flexion degree reaches the peak value.

Influence of advanced glycosylation end products on wound healing of burn rats with diabetes / 中华烧伤杂志

<p><b>OBJECTIVE</b>To understand the influence of accumulation of advanced glycosylation end products (AGE) on wound healing of burn rats complicated with diabetes.</p><p><b>METHODS</b>Seventy-five SD rats were divided into control, diabetes, and aminoguanidine-interfered groups in completely randomized method, with 25 rats in each group. All rats were subjected to deep partial-thickness scald. Diabetes was reproduced in rats of diabetes and aminoguanidine-interfered groups. Rats in aminoguanidine-interfered group were fed with 100 mg x kg(-1) xd (-1) aminoguanidine. Rats were sacrificed on post-scald day (PSD) 0, 3, 7, 14, and 21, and portrait of the wounds were taken. Full-thickness skin tissue specimens were obtained for determination. Specimens of epidermis from back of SD rats were obtained for KC cultivation and verification. Wound healing rate, glucose content in skin tissue, morphologic change in wound tissue, AGE distribution in skin tissue, influence of AGE on proliferation and apoptosis of KC were observed.</p><p><b>RESULTS</b>Wound healing rate of rats was respectively lower in diabetes group than that in control group on PSD 7, 14, and 21 (P < 0.01), but it was obviously higher in aminoguanidine-interfered group than that in the former 2 groups (P < 0.01). Glucose content of rat skin in diabetes group was (2.62 +/- 0.19) mmol/g, and it was (2.58 +/- 0.07) mmol/g in aminoguanidine-interfered group, both higher than that in control group [(1.04 +/- 0.09) mmol/g, P < 0.01]. In control group, limited intensive infiltration of inflammatory cells was found in the wound with necrotic tissue formation which fell off in time, and with no obvious delay of wound healing. In diabetes group, infiltration of inflammatory cells in wounds of rats appeared slowly, but diffusely and persistently; necrotic tissue formed and fell off late in time, with obvious delay of wound healing. In aminoguanidine-interfered group, intensive infiltration of inflammatory cells was observed in time, and the time of necrotic tissue formation and sloughing, and wound healing were respectively earlier than that in diabetes group. Sporadic disposition of small amount of AGE was found in rats in control group. AGE accumulation increased significantly in rats in diabetes group. AGE content decreased significantly in rats in aminoguanidine-interfered group after administration of aminoguanidine. KC proliferation decreased significantly in concentration dependent manner 48 hours after AGE stimulation. Absorbance value of AGE decreased in each AGE-interfered group (P < 0.01). Early Annexin-V positive apoptotic KC rate was obviously higher in 100 ug/mL AGE-interfered group (15.1 +/- 2.3)% than that in control group [(11.2 +/- 1.2)%, P < 0.05]. There was no statistical significance between 100 ug/mL AGE-interfered group (14.3 +/- 3.5)% and control group (15.2 +/- 2.4)% in respect of the rate of double-positive cells apoptosis at final stage (P > 0.05).</p><p><b>CONCLUSIONS</b>Hyperglycemia may inhibit proliferation of repairing cells such as KC through AGE accumulation, thus impedes wound healing. Reduction of AGE accumulation could ameliorate wound healing delay due to diabetes.</p>

Effect of advanced glycosylation end products on cell cycle of epidermal keratinocyte and the role of signal pathway / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effect of advanced glycosylation end products (AGE) on cell cycle of epidermal keratinocyte and its possible signal pathway.</p><p><b>METHODS</b>150 mg/L AGE-human serum albumin (AGE-HSA) was prepared in vitro. Primary cultured keratinocytes in logarithmic growth phase were harvested and divided randomly into: A group [with treatment of defined keratinocyte-SFM (DK-SFM) serum-free medium], B group (with treatment of DK-SFM medium including 150 mg/L AGE-HSA), C group (with DK-SFM medium after treatment of U0126) and group D (with D K-SFM medium including 150 mg/L AGE-HSA after treatment of U0126). Cell cycle distributions were analyzed by flow cytometer. The protein levels of cyclin D1, cyclin B1, CDK4 and p44/42 MAPK were measured by Western blot.</p><p><b>RESULTS</b>Compared with those of A group, the percentage of S-phase and G2/M-phase keratinocytes were decreased obviously in B group, the percentages of G2/M -phase keratinocytes showed the same tendency in C and D groups [(9.7 +/- 1.1)% , (9.8 +/- 0.7)%, respectively, P <0.05]. Compared with that of A group, the expression of cyclin D1 were decreased significantly in other groups, among which a weak expression was showed in D group. There was no obvious difference between A and B groups in CDK4, or cyclin B1 and p44/42 MAPK protein levels ,which were significantly higher than those in C and D groups.</p><p><b>CONCLUSION</b>AGEs inhibit the progress of cell cycle of keratinocytes by downregulation of cyclin D1 expression.</p>

A potential mechanism for impaired wound healing--cutaneous environmental disorders in diabetes mellitus / 中华烧伤杂志

Impaired wound healing in diabetes is a significant clinical problem which is thought to be associated with neuropathy and angiopathy previously . The present study indicates that accumulation of glucose and glycometabolic products in skin tissue, as the result of glycometabolic disorders, which contributes to cutaneous environmental alterations in diabetes mellitus, and subsequently induces the abnormal cell behaviors, cytokine alteration and matrix modification. Thus, diabetic neuropathy and angiopathy might be regarded as the pathological outcome of cutaneous environmental alterations. In conclusion, glycometabolism disorders could be described as one of the initial events for the alteration involving in the underlying cutaneous disorder which impair healing process. The related research focuses on the initial event of controlling disorders in wound healing and therefore contribute to providing the strategy of treatment as based on these approaches.

Amiloride attenuates hypoxia-induced proliferation of rats pulmonary artery smooth muscle cells by suppressing Na+/ H+ exchanger-1 / 中国应用生理学杂志

<p><b>AIM</b>To study the influence of Na+/H+ exchange inhibitor amiloride on hypoxia-induced proliferation in rats pulmonary artery smooth muscle cells (PASMCs), also observe the change of Na+/H+ exchanger-1 (NHE-1) activity and expression.</p><p><b>METHODS</b>Rats PASMGs were cultured in normoxia (21% O2) or hypoxia (2%O2) for 24 hours, as well as administered amiloride with various concentrations, cultured for 24 hours, then determined MTT OD values and rates of PCNA positive cells to investigate cells proliferation, moreover intracellular pH was determined by interactive Laser Cytometer, and Na+/H+ exchanger-1 mRNA expression was determined by RT-PCR.</p><p><b>RESULTS</b>Hypoxic exposure heightened intracellular pH and mRNA expression of NHE-1 in PASMCs, however, 3.123-50 micromol/L amiloride depressed them gradually. Additionally, hypoxic exposure raised MTT OD value and rates of PCNA positive cells, similarly, the above two indexes descended gradually with presence of 3.125-50 micromol/L amiloride.</p><p><b>CONCLUSION</b>Na+/H+ exchange inhibitor amiloride can suppress hypoxia-induced proliferation in pulmonary artery smooth muscle cells, which is due to depress activity and expression of NHE-1.</p>

Study on the proliferation of epidermal cells of wound edge in deep partial thickness scald injury in rat / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the rule and possible mechanism of epidermal proliferation in wound edge of deep partial thickness scald injury in rat.</p><p><b>METHODS</b>Twenty-four Sprague-Dawley rats inflicted with deep partial thickness scald were randomized into pre-scalding, 3 post-scalding day (PSD), 7PSD and 14PSD groups, with 6 rats in each group. Skin specimens from the wound edge were harvested for the observation of the histological characteristics of the epidermis. Cell cycles of epidermal cells were analyzed with flow cytometry. The expressions of cyclin D1, cyclin B1, cdk4 and the histone H1 kinase activity of MPF in epidermal cells were determined by Western blotting.</p><p><b>RESULTS</b>Augmentation of nuclei and nucleoli was found in the epidermal cells from the wound edge in 3PSD group, while increased number of epidermal cells with obviously augmented nuclei and nucleoli were found in 14PSD group. The percentage of the cells in S phase increased in 14 PSD group. The percentage of epidermal cells in G2/M phase began to increase in 3PSD group, and that in 7PSD (4.5 +/- 0.6) and 14PSD (5.4 +/- 1.0) groups were obviously higher than that in pre-scalding group (2.9 +/- 1.1, P < 0.05). The expression of cyclin D1 increased significantly in 3PSD group. The expression of cdk4 decreased in 3PSD group, but began to increase in 14PSD group. There was no difference in the expression of cyclin B1 among groups. The MPF activity was significantly increased in 14PSD group.</p><p><b>CONCLUSION</b>There was enhanced DNA synthesis and mitosis in epidermal cells of rats with deep partial scald during early post-scald stage, and active proliferation of epidermal cells was observed on 14PSD. The expression of cyclinD1/cdk4 complex and the activity of MPF increased since 14PSD, indicating that there was a special regulative pattern during wound healing.</p>

The influence of L-arginine on the angiogenesis in burn wounds in diabetic rats / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the possible mechanism of L-arginine supplementation on the angiogenesis of burn wounds in diabetic rats.</p><p><b>METHODS</b>One hundred male Sprague-Dawley (SD) rats were used in the study and were randomly divided into A (scalding control, n = 25), B (scalding of the rats with diabetes, n = 25), C (L-glycine control, n = 25) and D (L-arginine supplementation, n = 25) groups. Diabetes was produced by intra-peritoneal injection of streptozotocin (STZ) in B, C and D groups. The rats in C and D groups were gavaged with L-glycine and L-arginine in dose of 200 mg.kg(-1).d(-1), respectively. The glucose content of the back skin tissue was determined for five rats in each group eight weeks after STZ administration. Deep partial thickness scalding of 20% TBSA was engendered on the back in the other 80 rats. The wound area, wound healing rate, and microvascular density with CD34 immunohistochemistry staining were determined on 3rd, 7th, 14th, and 21st post scalding days (PSDs), In addition, the amount of nitric oxide (NO) released from the wound tissue and the tissue contents of vascular endothelial growth factor (VEGF) and transforming growth factor beta1 (TGF-beta1) from wound were determined at the above time points.</p><p><b>RESULTS</b>Compared to those in group B, the wound healing rate in group D increased significantly since the 7th PSD [(44.10 +/- 3.50)%, P < 0.05], and the wound MVD value was increased significantly at all postburn time points. Furthermore, the levels of VEGF, NO and TGF-beta1 in the wound tissue was also increased significantly, while the glucose content in the cutaneous tissue was decreased to (1.380 +/- 0.120) mg/g.</p><p><b>CONCLUSION</b>L-arginine supplementation could be beneficial to the angiogenesis in the burn wound of the rats with diabetes, as well as to wound healing by increasing the synthesis and the release of VEGF, NO and TGF-beta1 from burn wound and by decreasing the glucose content in the cutaneous tissue of diabetic rats.</p>

Effects of advanced glycation end-products on skin keratinocytes by NF-?B activation / 中华创伤杂志

Objective To investigate the effects of advanced glycation end-products(AGEPs)on the function of normal keratinocytes in vitro so as to explore the role of AGEPs in impaired wound healing. Methods Normal rat keratinocytes were incubated with different concentrations of AGEPs.After 48 hours of culturing,the cell proliferation rates were measured by MTT colorimetric determination.The cell cycle distributions and apoptosis were analyzed with flow cytometry,and the migration was investigated by 24-well fluorimetric cell migration assay kit by exposing to 100?g/ml AGEPs.Nuclear extracts from these cells were examined for binding of nucleotides containing NF-?B consensus by immunocytochemistry and EMSA in vitro.Results The proliferations of normal keratinocytes were significantly arrested and many cells were induced to early apoptosis compared with control ones(P＜0.05)by exposing to AGEPs for 48 hours. Meanwhile AGEPs also irritated keratinocytes migration compared with control ones(P＜0.05).Inhibiting the activation of NF-?B could partly recover the proliferation of keratinocytes,reverse apoptosis and attenu- ate migration.Conclusion AGEPs are correlated with the migration,proliferation and apoptosis of kera- tinocytes by NF-?B.