Effect of internal phase particle size on properties of site mixed emulsion explosive at plateau environment

To study the effect of internal particle size on the microstructure properties and thermal decomposition characteristics of site mixed emulsion explosive at different altitudes. Site mixed emulsion explosive was prepared with different shear rate. The particle size, viscosity, sensitized bubbles, detonation velocity and peak pressure of the emulsion explosive were tested after stored at different simulated altitudes. The thermal decomposition characteristics of emulsion matrix prepared at three different rotational speeds were measured by thermogravimetric analyzer and kinetic analysis was performed by non-isothermal model Kissinger-Akah-Sunose (KAS) method. The results show that with the increase in altitude, the internal phase size showed a trend of first increasing and then decreasing, and the number of sensitized bubbles within the emulsion explosive decreases. At an altitude of 0 m, the detonation velocity and peak overpressure of the emulsion explosive prepared by 1600 r min-1 increased 4.78% and 29.09%, respectively compared with 1200 r min-1, and at an altitude of 4500 m, the detonation velocity increased 11.87%, the peak overpressure increased 43.98%. The thermal decomposition activation energy of the emulsion matrix at 1600 r min-1 increased 13.14% compared to 1200 r min-1. It shows that in the production of site mixed emulsion explosive at high altitude, reducing the particle size of the internal phase of emulsion explosives in a certain range can effectively improve the performance of emulsion explosives.

[Initiation, development, and achievements of burn rehabilitation therapy in China]

Burn rehabilitation in China started from compression therapy in the mid-1970s, which showed the dual effects of prevention and treatment of hypertrophic scars. It not only promoted functional rehabilitation but also strengthened the confidence of patients in rehabilitation treatment. Thereafter, more therapies were brought into practice, such as intra-scar injection of triamcinolone acetonide, application of plastic splints, hydrotherapy, exercises with equipment, skin care, local therapeutic massage, active and passive exercises, as well as external use of drugs for inhibiting scars and pigments. Since the beginning of the 21st century, rehabilitation therapies have been gradually increasing. Psychological rehabilitation, occupational therapy, external use of silicone gel, wax therapy and sound, light, electricity, and radiation therapy have been carried out. Many hospitals have established foundations and held summer camps for children. As far as the whole country is concerned, compared with the huge demand, we still face a number of problems such as shortage of working staff, limited working space, capital chain rupture, lack of multi-disciplinary cooperation, untimely treatment, and incomplete rehabilitation. Nowadays, with increasing knowledge of burn rehabilitation and number of practitioners, improvement of equipment and economic situation, the pace of rehabilitation has accelerated, and the overall implementation of burn rehabilitation therapy has shown great vitality. Patients with burn injury involving over 80% total burn surface area (TBSA) of total burn area or full-thickness burn over 60% TBSA were cured and recovered in different levels of hospitals nationwide, which not only reflects the superb level of burn treatment in China but also reflects the overall improvement of rehabilitation level of the country.

Microwave-assisted one-step patterning of aqueous colloidal silver

A new approach of utilizing microwave to pattern gradient concentric silver nanoparticle ring structures has been presented. The width and height of a single ring and the space between adjacent rings can be adjusted by changing the silver colloidal concentration and the microwave output power. By simply enhancing the ambient vapour pressure to the saturated value during microwave-assisted evaporation, sub-100 nm rings can be deposited in between adjacent micro-rings over a distance of millimetres. Combined with microwave sintering, this approach can also create conductive silver tracks in a single step, showing huge potential in fabricating micro- and nano-electronic devices in an ultra-fast and cost-effective fashion.

Size-controlled growth of colloidal gold nanoplates and their high-purity acquisition

A facile while flexible approach to size-controllable high-purity colloidal gold nanoplates has been presented. By adjusting the quantity of seeds and I(-) through a seed-mediated, cetyltrimethylammonium bromide (CTABr)-assisted synthetic system, the edge length of the gold nanoplates can be adjusted from 140 to 30 nm without changing their thickness or crystal structure. By simply increasing the ion concentration of the reaction solution, the as-prepared gold nanoplates can be deposited due to the different electrostatic aggregation effects between nanoplates and spherical nanoparticles. Effective storage methods to keep the structural and optical stability of these gold nanoplates are also proposed.

[Inhibitory effects of benzoisoselenothiazolidone sulfonamide derivatives on cyclooxygenase]

AIM

To study the inhibitory effects of benzisoselenothiazolidone sulfonamide derivatives on cyclooxygenase.

METHODS

6-Keto-PGF1 alpha and PGE2 were assayed by radioimmunoassay (RIA) method; mRNA expression of COX-1 and COX-2 were assayed by reverse transcription-polymerase chain reaction (RT-PCR) method.

RESULTS

Compound A [N-4-(4-methoxyphenyl-aminosulfonyl)-benziososelenothiazolidone] and B [N-4-(4-fluorophenyl-aminosulfonyl)-benzoisoselenothiazolidone] were two benzoisoselenothiazolidone sulfonamide derivatives, which can inhibit COX activity with IC50 of 1.5 x 10(-8) mol.L-1 and 5.0 x 10(-8) mol.L-1 for COX-2, as well as IC50 of 1.5 x 10(-5) mol.L-1 and 2.8 x 10(-5) mol.L-1 for COX-1. The ratio of IC50 COX-1/IC50 COX-2 of compound A and B are 1,000 and 560, respectively. They both can inhibit COX-2 mRNA expression in cultured rat peritoneal macrophages stimulated with LPS (1 microgram.mL-1), and have no effect on COX-1 mRNA expressions.

CONCLUSION

Compound A and B, two benzoisoselenothiazolidone sulfonamide derivatives, both are selective inhibitory agents of COX-2, and possess inhibitory effects on 5-lipoxygenase and cyclooxygenase.

[Three dimensional quantitative structure-activity relationship of farnesyl protein transferase inhibitors]

AIM

To build a three dimensional structure model that correlates the biological activities and the structures of a series of farnesyl protein transferase (FPT) inhibitors exemplified by the compound of 2, 3,4,5-tetrahydro-1-(1H-imidazol-4-ylmethyl)-4-(2-biphenylylcarbonyl)-1H-1, 4-benzodiazepine.

METHODS AND RESULTS

Thirty-two FPT inhibitors with two types of scaffold were analyzed. Active conformations of which were studied using system search, a 3D-QSAR model were constructed using the method of comparative molecular field analysis (CoMFA). The resulting of cross-validated RCV2 = 0.602, non-cross-validated R2 = 0.958, SE = 0.270 and F = 124.5 indicate that the 3D-model possesses an ability to predict activities of new inhibitors.

CONCLUSION

The information of CoMFA model offers an approach to designing new FPT inhibitors.

[Study on the structure-activity relationships of retinoids. II. 3D-QSAR of retinoids and receptor interaction]

Precise prediction of the binding constant of ligand to receptor is an important aspect of structure-based drug design. Almost all methods including de novo design and 3D database search are over concentrated on structure generation rather than quantitative evaluation of the binding properties of the newly produced molecule. Using epididymal retinoic acid binding protein (ERABP) as a model, we simulated the interaction between retinoids and their receptor with DOCK program and obtained an equation for predicting the binding constants. According to the docking conformers of the ligands, CoMFA was also used to deduce a pharmacophoric model of this series of compound.

[Three dimensional quantitative structure-activity relationship of heterocyclic-compounds with di-tert-bultylphenyl inhibitors]

AIM

To quatitatively disclose the relationship between activity and structure of a new class of COX-II inhibitors containing dialkylphenyl-linked heterocyclic moieties.

METHODS AND RESULTS

Seventeen COX-II inhibitors from literature as a training set were investigated with the aim of developing a 3D-QSAR model using comparative molecular field analysis (CoMFA). To reveal the pharmacophoric pattern, several modes of superimposition were explored. The significant model shows a higher ability to explain and predict the activity of COX-II inhibitors, with the cross-validation RCV2 = 0.718, non cross-validation R2 = 0.992, F = 260,624, and SEE (standard error of estimate) = 0.072. Three compounds were selected as a predicting set, the low deviations of calculated values from the measured ones suggesting a powerful predictive ability of the model.

CONCLUSION

The 3D-QSAR explains the dependence of COX-2 inhibition upon the structures of the compounds. Some structure information for design of new COX-II inhibitors with higher activity has been given.

[Effect of improved topical agents on healing time of deep second-degree burn wound]

OBJECTIVE

With the recognization of the mechanism of wound healing, some topical agents are created and applied in trauma to improve the healing rate of wounds. The main purpose of this study is to investigate the effect of some topical agents on the healing rate of deep second-degree burn wounds.

METHODS

One thousand five hundred and sixty-three patients with deep second-degree burn wounds(total burn surface area < or = 10%) were involved in this study from January 1982 to December 1999. According to the application time of different treating measures including supplement of Zn, application of growth factors and collagenase, the patients were divided into 3 groups, wound healing rates were compared.

RESULTS

Before 1991, none of special topical agents were used, and the healing time of deep second-degree burn wounds was(23.8 +/- 3.5) days. From 1991 to 1996, with the topical application of SD-Ag-Zn, which can provide Zn for cells taking part in wound healing, the healing time of deep second-degree burn wounds was (20.6 +/- 3.2) days, earlier than no special topical agents (P < 0.05). From 1997 to 1999, growth factors such as basic fibroblast growth factor(bFGF) and epithelial growth factor (EGF) and collagenases were applied in wound treatment combining with SD-Ag-Zn, wound healing time was (16.2 +/- 2.8) days, earlier than no special topical agents (P < 0.01) and simple SD-Ag-Zn application (P < 0.05).

CONCLUSION

It indicates that the improvement of topical agents can accelerate wound healing speed.

[Study on 3D-QSAR of PPAR gamma agonists with thiazolidinedione and arylketo-acid moieties]

AIM

To build a model of two series of PPAR gamma agonists--thiazolidinedione and aryketo-acid derivatives using 3D-QSAR method, and to reveal the structural features affecting the binding activity to PPAR gamma, which relates to antihyperglycemic and antihyperlipidemic activity and has a potential application to the treatment of type II diabetes.

METHODS AND RESULTS

48 agonists with selective activity for PPAR gamma were analyzed using CoMFA. Based upon the active conformation of rosiglitazone (BRL) extracted from its complex with PPAR gamma all agonists were aligned. The model from CoMFA showed a high ability to explain and predict the activity of PPAR gamma agonists with cross-validation correlation coefficient R2 = 0.656, that of non-cross-validation R2 = 0.982, F10,37 = 201.1, and SE = 0.115.

CONCLUSION

The CoMFA contour map indicates that the steric fields mainly contribute to the binding effect, and especially a bulk group in the arylketo-acid series favors in the increase of affinity for PPAR gamma, as compared to the thiazolidinedione.

[Synthesis of triphenylethylene with aliphatic cyclic moiety and its antagonism on estrogen receptor]

AIM

In order to improve the biological activity and reduce the side effects and toxicity, a series of novel estrogen receptor antagonists were designed.

METHODS

The key triphenylethylene intermediates were obtained by the McMurry reaction. The target compounds were prepared by etherification. The binding affinities of the target compounds for the estrogen receptor in rat uterine cytosol were measured by a competitive binding assay and their estrogen agonistic/antagonistic properties were investigated in the 3-day uterine weight assay in the immature rats.

RESULTS

Thirty-five new compounds have been synthesized and their geometric configuration were determined by X-ray crystallography and 1HNMR spectral data.

CONCLUSION

All of the test compounds showed affinity for the estrogen receptor (IC50 < 10(-6) mol.L-1), especially compound 35 with IC50 1.07 x 10(-8) mol.L-1. Some compounds are antagonists, inhibiting uterus growth; others are agonists, promoting uterus growth. Compounds 14 and 27 are superior antagonists to tamoxifen.

[Expression and characterization of HIV-1 Gag p17-p24 protein]

The biological and immunological characteristics of HIV-1 core protein p17-24 expressed by recombinant vaccinia viruses were studied. The results of indirect immunofluorescence assay (I-IFA), Western blot and dot ELISA showed that the two recombinants could express the p24 gag and p17-24 gag fusion proteins in infected cell lines respectively. The electromicroscope observation revealed that the expressed proteins could also assemble into virus-like particles. The recombinant vaccinia viruses can also stimulate mice for the formation of anti HIV-1 Gag p24 antibody. When infected with the recombinant viruses, the chromosome DNA ladder caused by the apoptosis of the BHK cell was observed.

2-Carboxymethylendothal analogues as affinity probes for stabilized protein phosphatase 2A

Endothal (1diacid) and [3H]cantharidic acid ([3H]CA) bind with high affinity to the catalytic subunit of protein phosphatase 2A (PP2A). PP2A in liver cytosol was greatly stabilized with 30% glycerol as a preliminary step in the potential use of endothal-type derivatives for affinity chromatography. We report here the first introduction of a functionalizable group into endothal which allows retention of binding site affinity (assayed as [3H]CA binding in mouse liver cytosol). 2-Carboxymethylendothal anhydride (7) was prepared in two steps and 97% overall yield from cis-aconitic anhydride and furan. The potency of 7 was retained on conversion to two 2-carboxymethyl esters but not to two 2-(n-alkylcarboxamidomethyl) analogues.

[Effects of basic fibroblast growth factor on the healing of cutaneous chronic wounds]

OBJECTIVE

To observe the effects of basic fibroblast growth factor(bFGF) on the healing of cutaneous chronic wounds.

METHODS

Twenty-eight cases with thirty-three wounds from trauma, diabetes, pressure and radiation injuries were locally treated with bFGF in a dosage of 150 U/cm2 wounds. The healing time of wounds was used to evaluate the treatment results.

RESULTS

The healing time in all of chronic wounds were accelerated. All wounds from trauma, diabetes and pressure were healed within 4 weeks and another 2 wounds from radiation injuries were healed over 4 weeks. The healing rate within 4 weeks was 93.9%.

CONCLUSION

The results indicate that bFGF can be used as a promoter to accelerate the healing of chronic wounds in clinic.

[Structure-activity relationship studies of chalcones as SRS-A receptor antagonists]

A simple, reliable and highly sensitive bioassay with sensitized longitudinal strips of guinea pig ileum was used for screening the receptor antagonists of slow reacting substance of anaphylaxis (SRS-A). The SRS-A receptor antagonistic activities of 17 chalcones were studied. Most compounds in these chalcones were found to have SRS-A receptor antagonistic action at the concentration of 10(-4) mol.L-1. Among them, compounds 5, 13 and 17 were highly effective with IC50s of 7.5 x 10(-6), 7.5 x 10(-6) and 6.8 x 10(-5) mol.L-1, respectively. Under the same conditions, the IC50 of FPL 55712, a known leukotriene D4 receptor antagonist, was shown to be 3 x 10(-4) mol.L-1. It would appear that compounds 5, 13 and 17 were 40, 40 and 4.4 times more potent, respectively, than FPL 55712. From analysis of structure-activity relationship of chalcones, these results suggest that the following factors may be important for an active antagonist of SRS-A receptors: (a) There is a system of pi, pi conjugation in the molecule; (b) The ester group in the B ring of chalcones is more favorable than the carboxyl group; (c) Antagonism for meta- or para-substituted derivatives of carboxyl or ester group in the B ring are more potent than ortho-substituted compounds; (d) The length of carbon chain of alkyl group in the A ring of chalcones is more effective for 1, 4 or 6 carbon atoms than for 10 or 14 carbon atoms.

[Studies on retinoids. IV. Design, synthesis and structure-activity relationships of di-t-butylphenyl compounds]

Retinoic acid and its analogues play important roles in modulating cell growth, differentiation, immunity and apoptosis. Clinically they are used for cancer chemoprevention and chemotherapy. Based upon the moiety of 3,5-di-t-butyl-4-hydroxy phenyl ring, a series of substituted aromatic amide, ester and chalcones were designed and synthesized, which mimic the molecular shape, size, and spacial disposition of functional groups of retinoic acid. The general structure is as follows: [formula: see text] where R stands for hydrogen atom or methyl group, Y is the linkage -CONH-, -NHCO-, -COO-, -COCH = CH-, or a member of a heterocycle, X represents various substituents at different positions. The SAR indicates that the presence of hydrophobic group(s) at one end of the molecule, and a carboxyl group at the other end, and a conjugative system of molecule are necessary and full prerequisite for exhibiting activity. Loss of any one factor of them will abolish the activity. Being obligatory for anti-oxidative effect, the phenolic hydroxy group does not convey biological activity, because after methylation of the hydroxy group the compound increases the differentiation-inducing activity and loses the anti-oxidative effect, indicating that there is no correlation between the two activities. With a stable conformation of two phenyl rings with cis-conformation N-methylated acyl amide (No. 30) features in bent shape of the molecule, instead of an extended conformer, which is taken by the non-N-methylated partner and all-trans retinoic acid. A bent conformer of No. 30 accounts for the inactivity. In this paper compounds No. 4f, 4g, 5a, 7, 13, 32, 37, and 38 exhibited significant activity among them 4-[3-(3, 5-di-t-4-methoxyphenyl)-3-oxo-1-propenyl] benzoic acid (No. 38) showed high activity comparable to that of retinoic acid. The pharmacological action of No. 38 is under investigation.

[Synthesis and biological activity of tyrosine protein kinase inhibitors]

Four classes of 25 tyrosine protein kinase (TPK) inhibitors were designed and synthesized. Compounds 1-10 were tested to inhibit TPK of HL-60 leukemia cell using 32P-ATP method, and some of them exhibit evident inhibitory activities. Their structure-activity relationship is similar to that of TPK inhibitors reported in literatures. Compounds 11-25 were tested to inhibit TPK of normal rat spleen cell using ELISA method and their SAR is different from that using 32P-ATP method.

Anisodamine restores bowel circulation in burn shock

In a group of eight burn patients with a mean of 65.3 +/- 17.4 per cent TBSA burn injury (range 50-90 per cent TBSA), accompanied by a mean of 43.5 +/- 18.9 per cent TBSA full-thickness injury, it was shown that the evidence of global hypovolaemia had disappeared at 12 h after the injury following aggressive fluid resuscitation, while there was still a subnormal pHi of stomach at 48 h. As a prolonged period of inadequacy of oxygen delivery to the intestine might result in impairment of the intestinal mucosal barrier function, and then endogenous endotoxaemia might ensue, it seems to be important to correct intestinal hypoxia as early as possible. Since the inadequate perfusion to the gut wall is due to selective vasoconstriction of the mesenteric vasculature, logic dictates that the use of a vasodilator is in order. Anisodamine, an anticholinergic drug, was then given in six burn patients with comparable burn size and amount of fluid replenishment with the eight patients in the control group. It was clearly demonstrated that gastric pHi returned to normal before 48 h after injury. Plasma endotoxin and TNF contents were measured, and they were significantly lower than control values after 72 h. In conclusion, it is believed that anisodamine might be a valuable adjunct to the resuscitation regime of burn shock, and, therefore, a promising drug to abate endogenous endotoxaemia subsequent to splanchnic vasoconstriction due to hypovolaemia. The shortcomings of the drug were a mild abdominal distention and tachycardia after its administration.

[Clinical study of combined acupuncture-drug anesthesia for anterior approach cervical discectomy]

OBJECTIVE

To observe the effect of combined acupuncture-drug anesthesia for anterior approach cervical discectomy.

METHODS

Fifty patients scheduled for anterior approach cervical discectomy were randomized into two groups, the control group (5% procaine combined with drug anesthesia, n = 25), and the experiment group (combined acupuncture-drug anesthesia, n = 25). In the experiment group, bilateral acupoints of Neiguan (P6) and Hegu (LI4) of the patients were stimulated for 30 minutes by Hans Acupoint Nerve Stimulator through skin electrode while a combination of dolantin 25 mg and droperidol 2.5 mg were administered intravenously during induction.

RESULTS

There was no statistical difference of hemodynamic variation between the two groups (P < 0.05). The experiment group could also provide the same anesthesia effect as control group did, as well as it had less postoperative complications, more rapid recovery with less expense.

CONCLUSIONS

The acupuncture-drug anesthesia for anterior approach cervical discestomy is feasible and it is worthwhile to be widely used in clinical practice.

The association of circulating endotoxaemia with the development of multiple organ failure in burned patients

In this study, we examined the relationship of plasma endotoxin levels to the development of multiple organ failure (MOF), and the outcome in patients with thermal injury. A prospective cohort study of 17 patients admitted with burns covering more than 70 per cent of body surface area was undertaken. Circulating endotoxin concentrations were measured by modified limulus amoebocyte lysate assay in serial samples of plasma. Seven out of 17 burned patients developed MOF according to multiple criteria. The plasma endotoxin concentrations of patients with MOF were 0.512-1.127 EU/ml, which were significantly higher than that of 10 patients without MOF (0.216-0.553 EU/ml), on 3, 14, 21 and 28 days postburn (p < 0.05-0.01). A significantly higher incidence of positive endotoxin tests (> or = 0.120 EU/ml) was found in patients who developed MOF as compared to those patients who did not develop MOF during the observation period (p < 0.05). As the mean endotoxin levels increased, the incidence of MOF and death rate also increased, and persistent endotoxemia carried a poor prognosis. The present investigation provides further evidence that endotoxemia in severely burned patients commonly occurs. Circulating endotoxin has also been found to be strongly associated with the development of MOF and mortality following major burn injury.

Extensive wound excision in the acute shock stage in patients with major burns

In order to reduce excessive plasma loss, to alleviate the effects of devitalized tissues on the body, and to shorten the time in hospital, we attempted to perform extensive escharectomy during the shock period in extensively burned patients. Group A consisted of 21 patients, aged 9-45 years, with a mean total burn area of 63.2 +/- 18.1 per cent TBSA, and full-thickness injury involving 35.9 +/- 19.6 per cent TBSA. The first escharectomy was performed at 24.1 +/- 13.9 h postburn. The excision area averaged 32.3 +/- 6.7 per cent TBSA (range 24-96 per cent). In 15 patients a Swan-Ganz catheter was introduced to monitor haemodynamic changes. It was found that RAP, PAP, PAWP, ABP, HR, CO and CI were all stable during and after the operation. Group B consisted of 29 patients, and escharectomy was begun 4-5 days postburn. The mean healing time of the patients in group A was 33.1 days, which was shorter than that in group B (40.1 days). The period of haemoconcentration was shorter in group A and the amount of blood required during the first 2 weeks was almost 700 ml less in group A. There were fewer visceral complications in group A and smaller amounts of antibiotics were required in this group. The authors believe that escharectomy during the shock stage is feasible.

[Delayed fluid resuscitation induced bacterial translocation after lethal thermal injury: role of oxygen free radical injury of intestinal mucosa]

The Present investigation was undertaken to examine the effect of delayed fluid resuscitation (DFR), after lethal thermal injury on oxygen free radical (OFR) injury of intestinal mucosa and its relationship to bacterial translocation. Four groups of gnotobiotic rats with 5 strains of bacteria were studied: sham injury group (control) (n = 6): early fluid resuscitation (EFR) group (n = 24) receiving resuscitation (Parkland) immediately after scald (40% TBSA, third degree); DFR group (n = 24) receiving resuscitation 6 hours after scald; treatment group (n = 12), rats with DFR receiving VitE and VitC treatment before resuscitation 12, 24, 48 and 72 hours after injury, animals (n = 6, at each point) were sacrificed. Plasma endotoxin level, mucosal SOD, GSHPx, MDA and diamine oxidase (DAO) of ileum were determined, and cultures of the mesenteric lymph nodes (MLN), liver, spleen, heart, lung, kidney and blood were done. The level of mucosal MDA and plasma endotoxin and the incidence of bacteria translocation (IBT) to tissues were significantly higher and mucosal SOD, GSHPx, DAO activity significantly lower in DFR group as compared with that in EFR group at most of the time points. In DFR group, mucosal MDA content was negatively correlated with mucosal DAO activity, which correlated positively with plasma endotoxin level and IBT. After treatment with VitE and VitC, mucosal MDA content was decreased, plasma endotoxin level and IBT were significantly decreased, and mucosal DAO activity was significantly increased. Our data indicated that DFR in cases of burn shock can result in OFR injury of intestinal mucosa, disrupting mucosal barrier and promoting translocation of intestinal bacteria and endotoxin.

[Influential factors of water evaporation from burn wound]

To determine various influential factors of water evaporation from burn wound, we scalded 120 rats and divided them randomly into 12 groups. The rate of evaporation was studied under different temperatures and moistures. The experimental results showed that high temperature and low moisture were beneficial to the treatment of burn wound. Escharectomy, skin grafting and film forming agents could reduce evaporation. Azone could change the permeability of the skin and accelerate water evaporation.

[Comparison of therapeutic value of various topical agents in Pseudomonas aeruginosa infection. An experimental study]

40 Wistar rats were scalded by boiling water for 12 seconds resulting to 10% TBSA full-thickness burn. Pseudomonas aeruginosa (10(9)/ml) was smeared on the burn wounds 10 min after injury. The animals were divided into 4 groups. Sulfadiazine silver and sulfadiazine zinc (with 5% azone) cream was applied to the wounds of animals in the group 1. The contaminated wounds were irradiated with negative ion current in the group 2. The "moisture ointment" was applied to the wounds in the group 3. Group 4 consisted of the controls without any treatment. All the topical agents were applied to the wounds 4 hr after the injury. The number of bacteria in the subeschar tissue was determined every day for 4 days. The tissues of lung, kidney, liver and heart were examined pathologically on the 4th day. The results showed that the quantity of bacteria in the subeschar tissue was significantly less, and pathological changes in organs were significantly milder in the 1st and 2nd groups than other two groups. The "moisture ointment" group yielded the poorest results in respect to subeschar bacterial counts and visceral pathology.

[Escharectomy during shock stage in extremely burned]

In order to stop excessive plasma loss, to alleviate noxious effects of devitalized tissues on the body, and to shorten the hospitalization time, we have attempted to perform extensive escharectomy during the shock period in extensively burned patients. Group 1 consisted of 17 patients, aged 19 to 45 years, with mean total burn area 58 +/- 15.9% TBSA, and full-thickness injury involving 32.0 +/- 17.2% TBSA. The first escharectomy was done at 26.2 +/- 14.6 h postburn, and excision area averaged 32.0 +/- 7.1% (24% to 46%). In 13 of them, Swan-Ganz catheter was introduced to monitor the hemodynamic changes. It was found that RAP, PAP, PAWP, ABP, HR, CO and CI were all stable during and after the operation. Group 2 consisted of 29 patients, in whom escharectomy was begun 4-5 days postburn. The mean healing time of the patients in group 1 was 31.7 days, which was shorter than that of group 2 (40.1 days). The duration of hemoconcentration was shorter in group 1. The amount of blood transfusion was almost 1000 ml less in group 1 during the first two weeks. Less antibiotics were used with fewer visceral complications in group 1. The authors believe that escharectomy during the burn shock stage is feasible.

[Evaluation of nutritional in 149 severely burned patients]

By means of random sampling we selected 149 cases with over 30% TBSA burn (> 10% full-thickness) for evaluation of nutriment supplementation during treatment. We analysed daily caloric supply, nitrogen balance, amount of blood transfusion, Hb, A/G, transferrin, leukocyte, lymphocyte, IgG, Fn and body weight. The data support our impression that hyperalimentation can promote wound healing and raise the survival rate.

Pulmonary oedema in isolated lung lobe after inhalation injury

Pulmonary oedema was produced in isolated lung lobes with steam and provided direct continuous measurements of transudation as it occurred. Transvascular flux (Qf) and weight gain (Gw) of the lobe increased immediately and the transudation reached its peak within half an hour after inhalation injury. Studies of protein content, colloid osmotic pressure of bronchial exudate and water content of lung, reconfirmed the increase in pulmonary capillary permeability. Marked haemoconcentration was revealed. Plasma leaked 113 g (25 per cent), plasma protein leaked 1.96 g (9.7 per cent) during the experiment. Based on the measured arterial pressure (Pa), vein pressure (Pv), arterial occlusion (Pao), venous occlusion (Pvo), double occlusion (Pdo) and blood flow through the lobe (Qt), the total vascular (Rt), arterial (Ra), middle compartment (Rmid) and venous (Rv) resistances were calculated. All the resistances were increased and the Qt showed a decrease after inhalation injury.

The use of blood in burn shock. Clinical and experimental study

We have given whole blood as one of the main constituents of burn shock resuscitation for the past 28 years. To appraise the value of using whole blood, we have summarized the clinical experience of 2630 burn patients. Overall mortality was 4.18%. The lethal area of the burn were 50% of the population is expected to die was 82.8% total body surface area and 57.4% third-degree burns. The incidence of renal failure, pulmonary edema, and gastrointestinal bleeding was 0.9%, 0.4%, and 0.6% respectively. To confirm the advantage of transfusion of whole blood, we have carried out a series of experimental studies. Two groups of 25 dogs with 25% total body surface area full-thickness burns were treated with two resuscitation regimens. Group I was treated with whole blood, and group II with no blood, during the shock phase. After 48 hours, the infusions were stopped. Measurements were made before the burn and 2, 24, 48, 72, and 144 hours after the burn injury. The animals were then killed for histologic studies. From our data, we concluded that whole blood used in burn shock did not increase hemoconcentration or viscosity; it improved anemia, oncotic pressure, hypoproteinemia, acid-base balance, oxygenation, hemodynamics, and myocardial contractility, promoted cardionatrin secretion, reduced edema of tissue, and protected viscera from degenerative changes and bacterial colonization.

[Chemoprevention of cancer of the uterine cervix--preliminary study on the intervention of the cervical precancerous lesion by retinamide RII]

Twenty seven women with mild, moderate or severe cervical dysplasia proven by pathology were treated by retinamide RII suppository. Retinamide RII suppository, 10 mg QD, was given intravaginally for six months (three months as a course). Clinical examination, Papanicolaou cytology and tissue biopsy under colposcope were carried out before and after treatment. The results indicated that after the second course, 26 out of 27 patients responded; of them, precancerous lesions disappeared in 24 and even normal squamous epithelium was observed in 3. The overall response rate was 96.29% and the marked response rate was 88.89%. The general side effects were mild. There was little cervical and vaginal irritation which was well tolerated. The results of this clinical trial make available a practical base for chemoprevention of cervical cancer.

Examination of the interrelationship between aliphatic group dipole moment and polar substituent constants

The relationships between 210 aliphatic group dipole moments (mu) and Taft polar constants (sigma *) are explored, and they are shown to be correlated by a general equation: mu = -a X sigma * -b X n' -c, where a, b, and c are constants. The value n' is a parameter reflecting the attenuating factor due to the number and electronic nature of the interval atoms between the most electronegative atom and the first atom connected to the acetate in the measurement of sigma *. The mu and sigma * values of over 214 aliphatic substituents are compiled for future correlation studies. Comparative examples using sigma * and mu in quantitative structure-activity relationships are presented.

Inhibition of human dihydrofolate reductase by 4,6-diamino-1,2-dihydro-2,2-dimethyl-1-(substituted-phenyl)-s-triazine s. A quantitative structure-activity relationship analysis

The inhibitory activity of 101 4,6-diamino-1,2-dihydro-2,2-dimethyl-1-(substituted-phenyl)-s-triazines against purified dihydrofolate reductase from human lymphoblastoid cell (WIL 2) has been studied. From the obtained Kiapp values, quantitative structure-activity relationships (QSAR) have been derived. The QSAR from human dihydrofolate reductase are compared with QSAR for triazines inhibiting bovine and murine tumor DHFR, as well with QSAR for their inhibitory action on murine tumor cell culture.