[A prospective study of the effect and mechanism of autologous platelet-rich plasma combined with Meek microskin grafts in repairing the wounds of limbs in severely burned patients]

Objective: To observe the effect of autologous platelet-rich plasma (PRP) combined with Meek microskin grafts in repairing the wounds of limbs in severely burned patients, and to explore the mechanism. Methods: The prospective controlled research method was used. From September 2016 to January 2020, 16 patients aged 18-69 years, with extensive deep burns, including 9 males and 7 females, who met the selection criteria were admitted to the Department of Burns and Plastic Surgery of the 909th Hospital of the Joint Logistic Support Force of PLA. The bilateral limbs with similar injury in 8 patients were divided into Meek skin grafting+PRP group and Meek skin grafting alone group according to the random number table; in the other 8 patients, the limbs with severer injury were included in Meek skin grafting+PRP group, and the limbs on the other side were included in Meek skin grafting alone group. The wounds of affected limbs in the two groups were treated correspondingly. On post surgery day (PSD) 10, the survival and fusion of Meek microskin grafts were observed and the survival rate and fusion rate were calculated; the histological morphology and the angiogenesis of the basal tissue of Meek microskin graft were observed by hematoxylin-eosin staining and immunohistochemical staining, respectively, with the microvessels being counted. Data were statistically analyzed with paired sample t test. Results: On PSD 10, the wounds of affected limbs in Meek skin grafting+PRP group were dry, and most of the transplanted skin grafts were closely adhered to the basal tissue; while a small amount of exudate could be found in the wounds of affected limbs in Meek skin grafting alone group, and a small part of the transplanted microskin grafts fell off or poorly attached to the basal tissue. On PSD 10, the survival rate and the fusion rate of Meek microskin grafts in the wounds of affected limbs in Meek skin grafting+PRP group were (94±3)% and (86±4)%, which were significantly higher than (89±4)% and (79±4)% of Meek skin grafting alone group, respectively (t=3.633, 4.229, P<0.01). On PSD 10, the basal epidermis was closely connected with dermis of Meek microskin grafts in the wounds of affected limbs in Meek skin grafting+PRP group, with more inflammatory cell infiltration and active microvascular hyperplasia, while the basal epidermis was less closely connected with dermis of Meek microskin grafts in the wounds of affected limbs in Meek skin grafting alone group, with obvious degeneration of collagen fibers under the dermis, less inflammatory cell infiltration, and slightly poor microvascular hyperplasia. On PSD 10, the distribution of microvessels in basal tissue of Meek microskin grafts in the wounds of affected limbs in Meek skin grafting+PRP group were densely clustered, while the distribution of microvessels in Meek skin grafting alone group were scattered, sparse, and dotted. On PSD 10, the number of microvessels in basal tissue of Meek microskin grafts in the wounds of affected limbs in Meek skin grafting+PRP group was 36±6 in each 400-fold visual field, which was significantly more than 29±7 of Meek skin grafting alone group (t=2.671, P<0.05). Conclusions: Autologous PRP can effectively promote the survival rate and fusion rate of Meek microskin grafts in the wounds of limbs after escharectomy in severely burned patients by promoting angiogenesis at the base of Meek microskin grafts.

[Clinical study of anti-human T cell porcine immunoglobulin with recombinant human tumor necrosis factor-α receptor II: IgG Fc in the treatment of 35 cases of grade III/IV acute graft-versus-host disease after allo-HSCT]

Objective: To evaluate the efficacy and safety of anti-human T lymphocyte porcine immunoglobulin (P-ATG) with recombinant human tumor necrosis factor-α receptor Ⅱ:IgG Fc fusion protein (rhTNFR∶Fc, Etanercept) on grade Ⅲ/Ⅳ acute graft-versus-host disease (aGVHD) after allogenic hematopoietic stem cell transplantation (allo-HSCT) . Methods: Thirty-five patients with Grade Ⅲ/Ⅳ aGVHD who received P-ATG with etanercept therapy after allo-HSCT were retrospectively analyzed. P-ATGs (5 mg·kg(-1)·d(-1)) were administrated for 3 to 5 days, and then 5mg/kg was sequentially administrated, QOD to BIW. Etanercepts were administrated 25 mg, twice a week (12.5 mg, BIW for pediatric patients) . Results: Among the 35 patients with grade Ⅲ/Ⅳ aGVHD, 21 were males and 14 females, with a median age of 10 (3-54) years. A total of 19 cases of acute myeloid leukemia, 13 of acute lymphoblastic leukemia, 1 of severe aplastic anemia, 1 of myelodysplastic syndrome, and 1 of mixed phenotypic acute leukemia were noted. The overall response (OR) rate of P-ATG with etanercept was 85.7% (30/35) , with complete response (CR) and partial response (PR) rates of 34.3% (12/35) and 51.4% (18/35) , respectively, on day 28. The OR rate of grade Ⅲ aGVHD group was higher than of grade IV aGVHD group [100% (19/19) vs. 68.8% (11/16) , P=0.004]. On day 56, the OR rate became 77.2% (27/35) , with CR and PR rates of 62.9% (22/35) and 14.3% (5/35) , respectively. The OR rate of grade Ⅲ aGVHD group was also higher than of grade Ⅳ aGVHD group [89.5% (17/19) vs. 62.5% (10/16) , P=0.009]. Thirty-five patients had no adverse effects such as fever, chills, and rash during the P-ATG infusion, and no obvious liver and kidney function damage was observed after treatment. The main treatment-related complication was infection. The reactivation rates of CMV and EBV were 77.1% (27/35) and 22.9% (8/35) , respectively, and the bacterial infection rate was 48.6% (17/35) . With a median follow-up time of 13 (1-55) months after HSCT, the 1-year and 2-year OS rates were (68.1±8.0) % and (64.3±8.4) % , respectively. The 1-year OS rate of grade Ⅲ aGVHD group was superior to grade Ⅳ aGVHD group [ (84.2±8.4) % vs. (47.6±13.1) % , χ(2)=3.38, P=0.05]. Conclusion: This study demonstrated that P-ATG with etanercept was effective and safe in treating grade Ⅲ-Ⅳ aGVHD after allo-HSCT.

[Clinical analysis and laboratory diagnosis of three cases with infantile botulism caused by Clostridium botulinum type B]

Objective: To summarize the clinical characteristics and laboratory diagnostic methods of infant botulism caused by Clostridium botulinum type B. Methods: Clinical data of 3 infants with type B botulism who were admitted to Children's Hospital Affiliated to Capital Institute of Pediatrics from May to November 2018 were retrospectively analyzed. Botulinum toxin was detected in fecal samples or fecal enrichment solution of the patients, and Clostridium botulinum was cultured and isolated from fecal samples. Results: The age of onset of the patients (two boys and one girl) was 3, 3 and 8 months old, respectively. Two cases had the onset in May and one case had the onset in November. There were two cases with mixed feeding and one case with breast feeding. One case's family members engaged in meat processing. All of them were previously healthy. All the children presented with acute flaccid paralysis, cranial nerve involvement and difficult defecation. Two cases had secondary urinary tract infection. Electromyograms of two cases showed that action potential amplitude of the motor nerve were lower than those of their peers. After treatments including intravenous human immunoglobulin, respiratory tract management, urethral catheterization, nasal feeding, etc., three cases recovered completely 2 to 4 months later. Type B botulinum toxin was detected in the fecal diluent of one patient, and the TPGYT enrichment solution and cooked meet medium of the feces of 3 patients, respectively. Clostridium botulinum B was identified from the feces of 3 infants after culture, isolation and purification. Conclusions: Combined with typical clinical manifestations including acute flaccid paralysis, cranial nerve involvement symptoms and difficult defecation examination, infant botulism can be clinically diagnosed. The detection of fecal botulinum toxin and the culture and isolation of Clostridium botulinum are helpful for the diagnosis.

A fluorescent probe for H2S in vivo with fast response and high sensitivity

In this work, a fluorescent probe has been designed and synthesized that could be applied for monitoring and imaging exogenous or endogenous H₂S in live MCF-7 cells and in live mice with the fastest response.

Electron density compression and oscillating effects on laser energy absorption in overdense plasma targets

An analytical model for energy absorption during the interaction of an ultrashort, ultraintense laser with an overdense plasma is proposed. Both the compression effect of the electron density profile and the oscillation of the electron plasma surface are self-consistently included, which exhibit significant influences on the laser energy absorption. Based on our model, the general scaling law of the compression effect depending on laser strength and initial density is derived, and the temporal variation of the laser absorption due to the boundary oscillating effect is presented. It is found that due to the oscillation of the electron plasma surface, the laser absorption rate will vibrate periodically at ω or 2ω frequency for the p-polarized and s-polarized laser, respectively. The effect of plasma collision on the laser absorption has also been investigated, which shows a considerable rise in absorption with increasing electron-ion collision frequency for both polarizations.

Mobility of acid-treated carbon nanotubes in water-saturated porous media

The production, use, and disposal of nanomaterials may inevitably lead to their appearance in water. With the development of new industries around nanomaterials, it seems necessary to be concerned about the transport of nanomaterials in the environment. In this paper, the transport of acid-treated carbon nanotubes (CNTs) in porous media was investigated. Before the mobility investigation, the stability of acid-treated CNT dispersions was studied using ultraviolet-visible spectra and it was indicated that, under the chemical conditions employed in this work, there was no apparent aggregation. The mobility investigation showed that transport of acid-treated CNTs increased with treatment time due to increase in particle zeta potential. Carbon nanotubes treated with nitric acid for 2, 6, and 12 h possessed measured zeta potentials of -30.0, -43.0, and -48.5 mV, respectively. Utilizing clean-bed filtration theory, we showed that acid-treated CNTs have the potential to migrate 3.28, 5.67, and 7.69 m in saturated glass beads, respectively. We showed that solution ionic strength and pH have important effects on the mobility of acid-treated CNTs. Increasing the pH from 6.0 to 7.9 resulted in an increase in migration potential from 2.96 to 10.86 m. Increasing the ionic strength from 0.005 to 0.020 M resulted in a decrease in CNT migration potential from 5.67 to 1.42 m.

[Kinetics of inactivation of calf intestine alkaline phosphatase by EDTA with absorption spectrum method]

Calf intestinal alkaline phosphatase (EC.3.1.3.1) is a dimeric metalloenzyme composed of two identical subunits, the each active site of which contains a tight cluster of two zinc ions and one magnesium ion. The kinetic theory of the substrate reaction during irreversible inhibition of enzyme activity previously described by Tsou has been applied for a study on the kinetics of the course of inactivation of the enzyme by EDTA. The kinetics of the substrate reaction with different concentrations of the substrate p-nitrophenylphosphate (PNPP) and inactivator EDTA suggested a competitive complexing mechanism for inactivation by EDTA, and the process of inactivation composed of the rapid initial formation of an enzyme-EDTA complex, in which the conformation of enzyme has been changed, and then zinc ions are finally removed from the enzyme.

[Diabetic myocardiopathy]

Three cases of diabetic myocardiopathy having history of diabetes, angina and left ventricular dysfunction of various degrees and confirmed by coronary angiography and endomyocardial biopsy were reported. Electrocardiography showed significant ST-T changes simulating coronary insufficiency but without definite localization. As to the treatment, nitrate preparations, inotropic agents such as strophanthin K, digoxin etc. were used to relieve the symptoms; insulin was also administered to control the blood glucose level. Diltiazem, a calcium blocker, is also of help in alleviating the symptoms. It is shown in the present study and in the literatures as well that diabetic myocardiopathy is a disease showing intramural microvascular endothelial proliferation and swelling as well as subendothelial accumulation of acid glycogen deposition cells. The transportation of intracellular calcium ions and the cellular metabolism are thus affected, so there are extensive ischemia, focal necrosis and fibrosis in the myocardium with resulting cardiac dysfunction. The authors are, therefore, of the opinion that diabetic myocardiopathy is a specific and separate clinical entity.

Cytodiagnosis of bone tumors by fine needle aspiration

A retrospective study was undertaken of bone lesions examined by preoperative fine needle aspiration (FNA) cytology in our hospital during the ten-year period from 1970 to 1979. The 430 cytologically examined lesions were classified into three groups: inflammatory lesions, tumorlike lesions and tumors. A total of 54 patients had undergone surgery, with most of the lesions in those cases proven to be tumors or tumorlike by histologic study. Correlation between the histologic and FNA cytologic findings showed complete compatibility in 76% of the cases, partial compatibility in 13% and incompatibility in 11%. It is concluded that FNA biopsy is appropriate for identifying bone tumors and tumorlike lesions if sufficient numbers of tumor cells are obtained for morphologic examination. Although aspiration cytodiagnosis can be of considerable value in the recognition of certain bone lesions, it cannot replace formal tissue biopsy in the diagnosis of primary bone neoplasms. The morphology of several common bone tumors is described in detail and their differential diagnosis is discussed.