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1.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 58(11): 1159-1165, 2023 Oct 26.
Article in Chinese | MEDLINE | ID: mdl-37885189

ABSTRACT

Objective: To summarize the preliminary experience of endoscopically assisted mid-cheek benign tumor resection using a single preauricular or transoral incision and to evaluate its indications, advantages, and disadvantages. Methods: Thirty-six patients with benign mid-cheek tumors were prospectively enrolled, including 11 males and 25 females, aged (37.2±15.9) years and ranged from 11 to 65 years old. The patients were randomly divided into two groups: endoscope-assisted tumor dissections through a single preauricular incision (19 cases) or transoral incision (17 cases). Their surgical approaches were introduced, and the tumor long-axis length, incision length, operative time, estimated intraoperative bleeding, postoperative drainage amount and time, aesthetic satisfaction, perioperative complications, and follow-up were recorded and analyzed. Results: The difference between the tumor long-axis lengths in the preauricular group [(2.2±0.9) cm] and the transoral group [(2.1±0.7) cm] was not statistically significant (t=0.46, P=0.687), and all surgical procedures were completed as planned. There was no significant difference in the incision size (t=1.57, P=0.100) or operative time (t=0.44, P=0.736). Compared with the preauricular group [(30.8±8.7) ml], transoral incision [(23.6±8.9) ml] reduced intraoperative blood loss (t=2.97, P=0.006) and improved aesthetic pleasure (t=3.44, P=0.015). Two cases of earlobe numbness and one case of temporary facial palsy were observed in the preauricular group; two cases of postoperative effusion were noted in the transoral group, and no signs of nerve injury were detected. No tumor recurrence was found during the 1-54-month of follow-up. perioperative complications. Conclusions: Endoscopic-assisted preauricular or transoral incision for dissecting mid-cheek benign tumors provides excellent aesthetic and minimally invasive results, reducing complications and obtaining satisfactory aesthetic results.

2.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(2): 115-118, 2020 Feb 09.
Article in Chinese | MEDLINE | ID: mdl-32074673

ABSTRACT

Objective: To introduce a new surgical procedure for the treatment of neck benign tumors by endoscopic techniques. Methods: Seventeen patients with neck benign tumor underwent surgery by endoscope through a concealed incision in Department of Oral and Maxillofacial Surgery, Qilu Hospital of Shandong University from January 2018 to August 2019 were analyzed, which included 3 cases of tumor in the submental area, 2 cases in submandibular region, 9 cases in lower pole region of parotid gland, 1 case in superior region of sternocleidomastoid muscle, 1 case in central region of sternocleidomastoid muscle, 1 case in inferior region of sternocleidomastoid muscle. All patients underwent routine preoperative examination and CT examination to evaluate tumor size, boundary, morphology and nature. According to the area where the tumor located, concealed incisions in different sites were designed. Lumps in the submental area and submandibular area were treated with oral vestibular sulcus incision. Benign tumors located in the lower pole region of parotid gland and the sternocleidomastoid muscle region were treated with approach of the short hidden postauricular incision. During the operation, the self-developed "maxillofacial suspension device" was used to provide the operating space. The tumors were completely removed with endoscope and all patients were followed up every 3 months. Results: All surgical procedures were performed as expected. Visual analogue scale (VAS) was 9.3 on average at 3 months after operation, all the patients were satisfied with the incision design and the cosmetic effect. No recurrences were found in patients with a follow-up period ranged from 1-15 months. Conclusions: These studies have shown that endoscope-assisted neck benign tumor resection is a surgical procedure with covert incision and good cosmetic results.


Subject(s)
Endoscopy , Head and Neck Neoplasms/surgery , Endoscopes , Humans
3.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 54(12): 847-850, 2019 Dec 09.
Article in Chinese | MEDLINE | ID: mdl-31874486

ABSTRACT

Objective: To summarize the preliminary experience of endoscope -assisted resection of superficial parotid gland benign tumors, and to discuss the indications, advantages and disadvantages of the operation. Methods: The clinical data of 18 patients who underwent extracapsular resection of superficial parotid gland benign tumor in Department of Oral and Maxillofacial Surgery, Qilu Hospital of Shandong University from March 2018 to March 2019 were retrospectively analyzed, and the surgical methods were introduced. The indications, long axis length of tumor, incision design, operation time, intraoperative blood loss, postoperative drainage and drainage time, aesthetic satisfaction, postoperative complications and follow-up time were counted. Results: All procedures were completed as expected. The length of the long axis of the tumor was (2.3±0.6) cm, the incision in the tragus around the earlobe was short and concealed, the incision length was (5.1±1.3) cm, the operation duration was (2.0±0.4) h, intraoperative blood loss was (168.9±18.8) ml, postoperative drainage was (29.5±11.7) ml, drainage time was (3.6±0.5) d, 2 cases of temporary facial paralysis or earlobe numbness, three months after the operation, the results of the visual analogue scale of the incision design and the aesthetic effect were (9.6±0.1). Conclusions: Endoscope-assisted resection of superficial parotid gland benign tumor by inner tragus around earlobe approach is applicable and reliable, can reduce complications, shorten surgical incision to obtain satisfactory aesthetic effect, which is worth further expansion and improvement.


Subject(s)
Endoscopy , Parotid Neoplasms/surgery , Esthetics, Dental , Humans , Parotid Gland/pathology , Parotid Gland/surgery , Postoperative Complications , Retrospective Studies
4.
Eur Rev Med Pharmacol Sci ; 22(14): 4542-4550, 2018 07.
Article in English | MEDLINE | ID: mdl-30058692

ABSTRACT

OBJECTIVE: Kinesin family member 5b (Kif5b), a conventional kinesin, mainly participates in lysosome and mitochondria transportation. Some studies have indicated that Kif5b may be associated with the development of a variety of tumors. However, the role Kif5b plays in oral squamous cell carcinoma (OSCC) has yet to be determined. Our study aimed at investigating the expression level of Kif5b in primary OSCC and discussing its clinical significance in patients' outcomes. PATIENTS AND METHODS: We measured Kif5b expression in 82 OSCC tissue samples with immunohistochemistry. The associations between the expression level of Kif5b and clinicopathological characteristics as well as patients' survival were statistically assessed. RESULTS: Kif5b level was significantly associated with tumor size (p=0.034), histological differentiation (p=0.028), disease recurrence (p=0.018), surrounding tissue invasion (p=0.045), recurrence time (p=0.036) and survival status (p=0.030). Kaplan-Meier cumulative survival analyses indicated that high expression of Kif5b was linked to worse overall survival (p=0.0112) and disease-free survival (p=0.0085). The univariate and multivariate Cox proportional hazard analysis further identified the expression status of Kif5b as an independent variable that correlated with patients' survival and recurrence. Furthermore, in 54 early-stage, clinically node negative OSCC patients, Kif5b expression were correlated with histological differentiation (p=0.034), disease recurrence (p=0.038) and surrounding tissue invasion (p=0.029). Univariate and multivariable logistic regression results showed that only Kif5b expression level could influence the probability of recurrence. CONCLUSIONS: Our results reveal that Kif5b expression is associated with poor clinical outcome in OSCC and even in early-stage, clinically node negative OSCC and may be a potential target for OSCC treatment.


Subject(s)
Kinesins/metabolism , Mouth Neoplasms/pathology , Neoplasm Recurrence, Local/diagnosis , Squamous Cell Carcinoma of Head and Neck/pathology , Disease Progression , Disease-Free Survival , Female , Follow-Up Studies , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Mouth Mucosa/pathology , Mouth Mucosa/surgery , Mouth Neoplasms/mortality , Mouth Neoplasms/surgery , Neoplasm Recurrence, Local/pathology , Prognosis , Squamous Cell Carcinoma of Head and Neck/mortality , Squamous Cell Carcinoma of Head and Neck/surgery , Survival Rate
5.
Rev Sci Instrum ; 84(6): 066102, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23822389

ABSTRACT

In this paper, by gripping the specimen on various positions, including the gripping section, stress concentration transition section, and gauge length section, theoretical analysis on the influences of gripping methods on tensile elastic modulus calculation was investigated with a group of equations. Then, an image-based displacement measurement system was implemented, and the experimental verification via in situ tensile testing was carried out to verify the feasibility of the theoretical analysis by a miniature tensile device integrated with a metallographic microscope. The stress-strain curves of 2026 aluminum alloy were also obtained by gripping the specimens on various positions to illustrate the influences of gripping methods. The influence of gripping methods on elongation measurement was also investigated. This paper showed a modular calculation method of elastic modulus for the tensile testing of typical plate specimens.

6.
Toxicon ; 39(10): 1561-6, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11478963

ABSTRACT

Mastoparan B (MP-B) is a cationic tetradecapeptide (LKLKSIVSWAKKVL-CONH(2)) isolated from the venom of the Taiwan hornet Vespa basalis. Unlike other vespid mastoparans, the peptide is capable of inducing short-term hypotension and causes hemolysis in animals. This study was aimed to find out MP-B analogs that possess higher hypotensive potency with the least lytic action by D-amino acid substitution, especially at lysine (Lys) residues. The synthetic MP-B isomer in which Lys(2) was replaced by D-Lys showed a significant decrease in both hemolytic and hypotensive activities. Substitution of Lys(4) by D-Lys in MP-B also caused a marked reduction of hemolytic activity, but its hypotensive action was only slightly affected. However, when Lys(11,12) were replaced by D-Lys, the resulting isomer ([D-Lys(11,12)]MP-B) exhibited a higher hypotensive activity with negligible hemolytic activity as compared with the native peptide. The D-antipot of MP-B in which all amino acid residues were replaced by D-isomers showed the highest hypotensive activity with a hemolytic activity about 1/5 that of MP-B. The results reveal that D-Lys substitution at the N-terminus of MP-B (Lys(2,4)) causes decreases in both hypotensive and hemolytic activities, while D-Lys substitution at the C-terminus (Lys(11,12)) leads to a significant increase in hypotensive activity of MP-B with a remarkable decrease in hemolytic activity. The hypotensive effect of [D-Lys(11,12)]MP-B was more prominent on spontaneously hypertensive rats. At a proper dose (0.3mg/kg) the peptide could reduce the high blood pressure (approximately 180 mmHg) of the rat to a normal level (approximately 120 mmHg) for more than 3h. [D-Lys(11,12)]MP-B which possesses a potent hypotensive action with the least cytolytic side effect is the best MP-B analog for studying the mechanism of cardiovascular inhibition by MP-B and could be useful as a hypotensive agent in hypertension crisis.


Subject(s)
Erythrocytes/drug effects , Hemolysis/drug effects , Hypotension/drug therapy , Lysine/chemistry , Peptides/chemistry , Peptides/chemical synthesis , Peptides/physiology , Wasp Venoms/chemistry , Amino Acid Sequence , Amino Acid Substitution , Animals , Blood Pressure/physiology , Chromatography, High Pressure Liquid , Circular Dichroism , Dose-Response Relationship, Drug , Guinea Pigs , Intercellular Signaling Peptides and Proteins , Male , Peptides/isolation & purification , Rats , Rats, Inbred SHR , Rats, Wistar , Stereoisomerism , Structure-Activity Relationship , Time Factors , Wasp Venoms/isolation & purification , Wasps
7.
Talanta ; 54(4): 603-9, 2001 May 30.
Article in English | MEDLINE | ID: mdl-18968283

ABSTRACT

A methodology based on the coupling of experimental design and artificial neural networks (ANNs) is proposed in the optimization of a flow injection system for the spectrophotometric determination of Ru (III) with m-acetylchlorophosphonazo (CPA-mA), which has been for the first time used for the optimization of high-performance capillary zone electrophoresis (J. Chromatogr. A 793 (1998) 317). And since it has been applied in many other regions like micellar electrokinetic chromatography, ion-interaction chromatography, HPLC, etc. (J. Chromatogr. A 850 (1999) 345; J. Chromatogr. A 799 (1998) 35; J. Chromatogr. A 799 (1998) 47). An orthogonal design is utilized to design the experimental protocol, in which five variables are varied simultaneously (Anal. Chim. Acta 360 (1998) 227). Feedforward-type neural networks with extended delta-bar-delta (EDBD) algorithm are applied to model the system, and the optimization of the experimental conditions is carried out in the neural network with 5-5-1 structure, which have been confirmed to be able to provide the maximum performance. In contrast to traditional methods, the use of this methodology has advantages in terms of a reduction in analysis time and an improvement in the ability of optimization. Under the optimum experimental conditions, Ru (III) can be determined in the range 0.040-0.60 mug ml(-1) with detection limit of 0.03 mug ml(-1) and the sampling frequency of 34 h(-1). The method has been applied to the determination of Ru (III) in refined ore as well as in secondary alloy and provided satisfactory results.

8.
Analyst ; 125(6): 1083-6, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10932854

ABSTRACT

The determination of icariin (IC), rhein (RH), chrysophanol (CH), physcion (PHY), glycyrrhetic acid (GE), and glycyrrhizic acid (GI), in traditional Chinese preparations, Anshen Bunao oral liquid and Maren pill, has been investigated by micellar electrokinetic capillary electrophoresis. With borate buffer (10 mM), SDS (20 mM) and acetonitrile (10%) as background electrolyte (pH 9.55), 20 kV applied voltage and 254 nm UV detection, the six active compounds were completely separated within 10 min. The effects of buffer pH, concentration of borate, SDS and modifier on electrophoretic behavior and separation are discussed. Regression equations revealed linear relationships (correlation coefficients: 0.9960-0.9999) between the peak-area of each component and the content. In addition, the levels of the six active compounds in two kinds of traditional Chinese medicinal preparations were easily determined with recoveries of from 94.7% to 106.4%.


Subject(s)
Drugs, Chinese Herbal/chemistry , Chromatography, Micellar Electrokinetic Capillary/methods
9.
Bioorg Med Chem ; 7(9): 1797-803, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10530927

ABSTRACT

Somatostatin analogues, such as octreotide, are useful for the visualization and treatment of tumors. Unfortunately, these compounds were produced synthetically using complex and inefficient procedures. Here, we describe a novel approach for the synthesis of octreotide and its analogues using p-carboxybenzaldehyde to anchor Fmoc-threoninol to solid phase resins. The reaction of the two hydroxyl groups of Fmoc-threoninol with p-carboxybenzaldehyde was catalyzed with p-toluenesulphonic acid in chloroform using a Dean-Stark apparatus to form Fmoc-threoninol p-carboxybenzacetal in 91% yield. The Fmoc-threoninol p-carboxybenzacetal acted as an Fmoc-amino acid derivative and the carboxyl group of Fmoc-threoninol p-carboxybenzacetal was coupled to an amine-resin via a DCC coupling reaction. The synthesis of protected octreotide and its conjugates were carried out in their entirety using a conventional Fmoc protocol and an autosynthesizer. The acetal was stable during the stepwise elongation of each Fmoc-amino acid as shown by the averaged coupling yield (> 95%). Octreotide (74 to 78% yield) and five conjugated derivatives were synthesized with high yields using this procedure, including three radiotherapy octreotides (62 to 75% yield) and two cellular markers (72 to 76% yield). This novel approach provides a strategy for the rapid and efficient large-scale synthesis of octreotide and its analogues for radiopharmaceutical and tagged conjugates.


Subject(s)
Octreotide/chemistry , Radiopharmaceuticals/pharmacology , Amino Acid Sequence , Chromatography, High Pressure Liquid
10.
Kaohsiung J Med Sci ; 15(6): 326-36, 1999 Jun.
Article in Chinese | MEDLINE | ID: mdl-10441940

ABSTRACT

The morphological changes of muscle cells and capillary endothelial cells of skeletal muscles were in wshigutet after long-term exercise training at various temperatures. One-hundred and forty rats were divided into seven groups and received a one-month exercise training at conditions of low (0 degree C), normal (26 degrees C) or high (42 degrees C) temperatures respectively. Muscle samples were obtained from extensor digitorum longus muscle (EDL) and soleus muscle (SOL) of each animal. These samples were used to observe the hitological differences by light microscope, and to observe the changes in the number of muscular mitochondria and capillary endothelial pinocytotic vesicles by electron microscope. We found that both low and high temperature groups had higher frequency of atrophy and necrosis in muscle fibers than the normal temperature group. Moreover, EDL muscle had significantly more mitochondria and pinocytotic vesicle than SOL muscle in the high and normal temperature groups. From these results, we suggested that changes of the environmental temperature cause histological malformations of muscle fibersabtw; in addition, these effects were more prominent in fast twitch muscles.


Subject(s)
Capillaries/cytology , Endothelium, Vascular/cytology , Muscle, Skeletal/cytology , Physical Conditioning, Animal , Temperature , Animals , Male , Rats , Rats, Wistar
11.
Biochem Biophys Res Commun ; 257(2): 500-10, 1999 Apr 13.
Article in English | MEDLINE | ID: mdl-10198241

ABSTRACT

We present a systematic structure comparison of three major classes of postsynaptic snake toxins, which include short and long chain alpha-type neurotoxins plus one angusticeps-type toxin of black mamba snake family. Two novel alpha-type neurotoxins isolated from Taiwan cobra (Naja naja atra) possessing distinct primary sequences and different postsynaptic neurotoxicities were taken as exemplars for short and long chain neurotoxins and compared with the major lethal short-chain neurotoxin in the same venom, i.e., cobrotoxin, based on the derived three-dimensional structure of this toxin in solution by NMR spectroscopy. A structure comparison among these two alpha-neurotoxins and angusticeps-type toxin (denoted as FS2) was carried out by the secondary-structure prediction together with computer homology-modeling based on multiple sequence alignment of their primary sequences and established NMR structures of cobrotoxin and FS2. It is of interest to find that upon pairwise superpositions of these modeled three-dimensional polypeptide chains, distinct differences in the overall peptide flexibility and interior microenvironment between these toxins can be detected along the three constituting polypeptide loops, which may reflect some intrinsic differences in the surface hydrophobicity of several hydrophobic peptide segments present on the surface loops of these toxin molecules as revealed by hydropathy profiles. Construction of a phylogenetic tree for these structurally related and functionally distinct toxins corroborates that all long and short toxins present in diverse snake families are evolutionarily related to each other, supposedly derived from an ancestral polypeptide by gene duplication and subsequent mutational substitutions leading to divergence of multiple three-loop toxin peptides.


Subject(s)
Computer Simulation , Models, Molecular , Neurotoxins/chemistry , Sequence Homology, Amino Acid , Snakes , Amino Acid Sequence , Animals , Crystallography, X-Ray , Elapid Venoms/chemistry , Elapid Venoms/classification , Isoelectric Point , Molecular Sequence Data , Molecular Weight , Neurotoxins/classification , Nuclear Magnetic Resonance, Biomolecular , Peptide Fragments/chemistry , Phylogeny , Protein Conformation , Protein Folding , Sequence Alignment , Structure-Activity Relationship
12.
Anal Biochem ; 267(2): 287-93, 1999 Feb 15.
Article in English | MEDLINE | ID: mdl-10036132

ABSTRACT

The hydrolysis of colominic acid under microwave irradiation was studied and compared with traditional heating methods. The microwave irradiation has several advantages over the heating method in the hydrolysis of colominic acid: (a) products with higher degrees of polymerization are obtained, (b) less lactone byproducts are observed, and (c) the hydrolytic rate is much faster. These advantages are probably due to the microwave effect. Oligosialic acids as the products of the acid hydrolysis of polysialic acid with conventional heating methods were fully lactonized, especially under the conditions of higher temperature and stronger acid.


Subject(s)
Polysaccharides/chemistry , Hydrolysis , Microwaves
13.
Angiology ; 49(5): 415-8, 1998 May.
Article in English | MEDLINE | ID: mdl-9591535

ABSTRACT

A 43-year-old man presenting with symptoms of congestive heart failure, cardiomegaly, and impaired left ventricular (LV) function was diagnosed as having a huge left renal arteriovenous (AV) fistula. The AV fistula might be attributed to a gunshot wound suffered during his military service twenty years ago. Percutaneous transcatheter arterial embolization utilizing multiple spring coils in conjunction with cyanoacrylic glue successfully occluded the fistula, with subsequent improvement of LV function and reduction of LV size on his serial echocardiographic follow-up.


Subject(s)
Arteriovenous Fistula/etiology , Kidney/injuries , Renal Artery/injuries , Vena Cava, Inferior/injuries , Wounds, Gunshot/complications , Adult , Arteriovenous Fistula/diagnostic imaging , Arteriovenous Fistula/therapy , Cardiomegaly/etiology , Cardiomegaly/therapy , Cyanoacrylates/therapeutic use , Echocardiography , Embolization, Therapeutic/instrumentation , Embolization, Therapeutic/methods , Follow-Up Studies , Heart Failure/etiology , Heart Failure/therapy , Humans , Male , Nephrectomy/adverse effects , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Left/therapy , Ventricular Function, Left , Wounds, Gunshot/surgery
14.
Biochem Biophys Res Commun ; 233(3): 713-6, 1997 Apr 28.
Article in English | MEDLINE | ID: mdl-9168920

ABSTRACT

The N-terminal leucine residue of snake venom cardiotoxin II (CTX II) (Naja naja atra) was systematically replaced with D-leucine (CTXII-L1-D-L), glycine (CTXII-L1G) or deleted [CTXII-(2-60)] to study the role of leucine residue in CTX II molecule. CTX II, CTXL1-D-L, CTXL1G and CTX(2-60) were produced by chemical synthesis method and purified by high performance liquid chromatography. Owing to folding problem in CTXII-(2-60), only CTX II, CTXII-L1-D-L and CTXII-L1G were produced in a pure form and characterized by amino acid analysis, mass spectrometry and peptide mapping. In the structural aspect, changing the Leu-1 by D-Leu or Gly causes a drastic alteration in the whole CTX II structure as detected by circular dichroism, 1-anilino-naphthalene-8-sulfonate (ANS) fluorescence assay. In the functional aspect, both CTXII-L1-D-L and CTXII-L1G are still retained substantial biological activity of CTX II. Therefore, the results indicate that both the chirality and the side-chain of the N-terminal leucine residue of CTX II are important elements in maintaining the whole CTX II structure. In addition, this study is the first report in elucidating the reason why the first N-terminal residue of most CTXs (90.3%) is leucine residue.


Subject(s)
Cobra Cardiotoxin Proteins/chemistry , Amino Acids/analysis , Animals , Circular Dichroism , Cobra Cardiotoxin Proteins/toxicity , Leucine/chemistry , Mice , Molecular Structure , Peptide Mapping , Protein Conformation , Spectrometry, Fluorescence , Stereoisomerism , Structure-Activity Relationship
15.
Protein Eng ; 10(10): 1227-33, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9488148

ABSTRACT

The propeptides of bacterial subtilisin BPN' and Carlsberg were synthesized to investigate their inhibitory function on the enzymes. Kinetically, pro-BPN' inhibits the proteolytic activities of subtilisin BPN' and Carlsberg separately in a slow binding mode. Pro-Carlsberg behaves as a typical rapid equilibrium competitive inhibitor for these two proteases. Functionally, pro-Carlsberg inhibits the subtilisins with moderate selectivity. The inhibition constant Ki of pro-BPN' to subtilisin BPN' is 5.0 nM, and 6.1 nM to subtilisin Carlsberg. The on-rate of pro-BPN' to subtilisin BPN' is 5.8 x 10(5) M(-1)s(-1), and the off-rate 2.9 x 10(-3) s(-1). Similarly, the on-rate of pro-BPN' to subtilisin Carlsberg is 2.2 x 10(5) M(-1)s(-1), and the off-rate 1.3 x 10(-3) s(-1). On the other hand, the Ki of pro-Carlsberg to subtilisin BPN' gives 1.3 x 10(2) nM, and 88 nM to subtilisin Carlsberg. Based on the key features of the interactions between pro-BPN' and subtilisin from X-ray crystallographic results (Gallagher et al., 1995), the correlation between the sequence of subtilisin propeptides and their inhibition abilities on the proteases are compared and discussed.


Subject(s)
Bacterial Proteins/chemistry , Protein Precursors/chemistry , Serine Proteinase Inhibitors/chemistry , Subtilisins/chemistry , Amino Acid Sequence , Amino Acids/analysis , Bacterial Proteins/metabolism , Circular Dichroism , Electrophoresis, Polyacrylamide Gel , Kinetics , Molecular Sequence Data , Oligopeptides/metabolism , Osmolar Concentration , Protein Precursors/metabolism , Serine Proteinase Inhibitors/metabolism , Subtilisins/metabolism
16.
Biochem Biophys Res Commun ; 227(1): 59-63, 1996 Oct 03.
Article in English | MEDLINE | ID: mdl-8858103

ABSTRACT

The tertiary structure of waglerin I has been determined by NMR and dynamic simulated annealing [Chuang et al., Biochim. Biophys. Acta 1292, 145-155 (1996)]. It is believed that the peptide basicity of waglerin may play an important role for its activity due to its high content of basic amino acids. In order to investigate the active site of the toxin, seven analogues of waglerin, [Ala3]-waglerin, [Ala7]-waglerin, [Ala10]-waglerin, [Ala14]-waglerin, [Ala18]-waglerin, [Ala20]-waglerin and [Ala22]-waglerin have been synthesized chemically by single replacement of basic amino acid residues one by one with Ala. By correlation of structures for each analogue with LD50 toxicity bioassays, it is found that the [Ala10]-waglerin exhibits no toxicity and the active site of the native toxin seems to reside in the proximity of the disulfide loop, which is spatially close to His10. Furthermore, the closer is the disulfide loop to the basic amino acid in waglerin, the more influential is the basic amino acid on the toxicity of waglerin. Based on the tertiary structure of waglerin, the structures of all synthetic analogues were derived based on computer-simulated modelling. By the pair-wise structural comparison, the disulfide loop in [Ala10]-waglerin analogue is found to be twisted as compared to the native form, in agreement with the lack of toxicity for this synthetic analogue.


Subject(s)
Amino Acids/chemistry , Crotalid Venoms/chemistry , Amino Acid Sequence , Animals , Computer Simulation , Crotalid Venoms/toxicity , Lethal Dose 50 , Magnetic Resonance Spectroscopy , Mice , Models, Molecular , Molecular Sequence Data , Protein Engineering , Protein Structure, Tertiary , Sequence Homology, Amino Acid , Structure-Activity Relationship
17.
Biochem Biophys Res Commun ; 227(2): 615-21, 1996 Oct 14.
Article in English | MEDLINE | ID: mdl-8878561

ABSTRACT

Human immunodeficiency virus type-1 Tat protein transactivates the gene expression of retrovirus. The unique cysteine-rich region of Tat protein is biologically essential. This study characterizes the structural features of a synthetic Tat21-38 peptide covering the cysteine-rich region with Zn binding property. UV titrations confirm Tat peptide binds with two Zn2+ cations maximally per monomer, as previously reported(1). Only monomer is observed from the electrospray mass spectrum. Interestingly, a modified Ellman reaction (2) can differentiate a metal chelated thiolate of cysteine residue from a free one. Three disulfide bonds are formed in apo-Tat21-38 peptide. One Tat21-38 molecule utilize four Cys residues in coordination with the first incorporated Zn2+ cation. Five out of seven Cys residues are coordinating with two Zn cations of the complex Zn-Tat21-38 (2:1). A model of the coordination arrangement of Zn binding sites at different states is proposed.


Subject(s)
Cysteine , Gene Products, tat/chemistry , Gene Products, tat/metabolism , HIV-1/metabolism , Protein Conformation , Zinc/metabolism , Amino Acid Sequence , Binding Sites , Cations, Divalent/metabolism , Circular Dichroism , Disulfides , Dithionitrobenzoic Acid , Mass Spectrometry , Models, Structural , Molecular Sequence Data , Oxidation-Reduction , Peptide Fragments/chemical synthesis , Peptide Fragments/chemistry , Spectrophotometry, Ultraviolet , tat Gene Products, Human Immunodeficiency Virus
18.
Kaohsiung J Med Sci ; 12(9): 544-8, 1996 Sep.
Article in Japanese | MEDLINE | ID: mdl-8819358

ABSTRACT

Twenty-four nursing college students aged 16 and 17 years were selected as research subjects and divided into two groups. Group A comprised 12 individuals who were trained for short distance running (5km/day) over a four-week period, while group B was trained for middle distance running (7km/day) during the same period. Blood AST (aspartate aminotransferase), ALT (alanine aminotransferase) and lactate were performed at rest (before training) and after exercise every week. After both short and middle distance exercise training, the lactate values after 1-3 week(s) training period were persistently higher than those before training and the differences between then are significant. However, the lactate value after 4 weeks training period is lower than that after the third week training. There are significant differences between the AST values after 1-4 week(s) training period and those before exercise in short distance exercise training. There are no significant differences between the AST values after training and those before exercise in middle distance exercise training. The ALT values after 1-4 week(s) training period were lower than those before exercise in short and middle distance exercise training. In conclusion, after 4 weeks training, the lactate and AST values can't reduce to those before training in middle distance exercise training, and the lactate value in short distance exercise training is the same as former. Further investigation is needed.


Subject(s)
Alanine Transaminase/blood , Aspartate Aminotransferases/blood , Lactic Acid/blood , Physical Education and Training , Adolescent , Female , Humans
19.
Toxicon ; 34(9): 1027-35, 1996 Sep.
Article in English | MEDLINE | ID: mdl-8896194

ABSTRACT

Mastoparan B (MP-B) is a cationic tetradecapeptide isolated from the black-bellied hornet (Vespa basalis) venom. It has a primary structure (LKLKSIVSWAKKVL-CONH2) distinct from other vespine mastoparans. The peptide caused a dose-dependent swelling in rat hind paw and showed a potent hemolytic activity in guinea pig red blood cells. Studies on the structure activity relationship of the peptide showed that replacing lysine at position 2 (Lys2) by asparagine (Asn) in the MP-B sequence caused about 40% decrease in its edema-inducing activity at 50 micrograms/paw and 90% decrease in hemolytic activity at 30 microM of the peptide, while the same substitution at Lys4 did not cause a significant change in either activity. Replacing either Lys11 or Lys12 by leucine (Leu) caused little or no decrease in the edema-inducing and hemolytic activities. Decreases in both activities were observed when both Lys11 and Lys12 were replaced by Leu. On the other hand, replacing tryptophan at position 9 (Trp9) by tyrosine or phenylalanine in MP-B sequence almost abolished its hemolytic activity, while the edema-inducing activity was only partially inhibited. Circular dichroism spectra of the peptides measured in 20% trifluoro-ethanol revealed that substitution of Lys and Trp did not cause a significant change in the conformation of MP-B. it appears that Lys2 is crucial for both hemolytic and edema-inducing activities of MP-B, while Trp9 is of special importance to the hemolytic activity of MP-B. Lys11 and Lys12 in MP-B probably play a lesser role in both activities.


Subject(s)
Peptides/toxicity , Wasp Venoms/toxicity , Amino Acid Sequence , Animals , Circular Dichroism , Dose-Response Relationship, Drug , Edema/chemically induced , Erythrocytes/drug effects , Guinea Pigs , Hemolysis/drug effects , Intercellular Signaling Peptides and Proteins , Lysine/metabolism , Peptides/chemistry , Peptides/isolation & purification , Rats , Rats, Wistar , Structure-Activity Relationship , Tryptamines/metabolism , Wasp Venoms/chemistry , Wasp Venoms/isolation & purification
20.
Biochem Biophys Res Commun ; 220(2): 246-54, 1996 Mar 18.
Article in English | MEDLINE | ID: mdl-8645291

ABSTRACT

An echistatin analogue, designated as des(46-49)-[Ala8,37]-echistatin gamma, was synthesized chemically by solid-phase peptide synthesis. The analogue was made by replacing Cys8 and Cys37 residues with two alanines and the deletion of C-terminal peptide 46-49 of echistatin gamma, resulting in an artificial polypeptide of 45 amino acids with three disulfide bonds. In the platelet aggregation assay, the analogue exhibits almost the same activity as echistatin gamma, indicating that the linear sequence of des(46-49)-[Ala8,37]-echistatin gamma contains all of the primary-structure information that is required for proper folding of this synthetic polypeptide. The tertiary structure of the analogue, as determined from high-resolution nuclear magnetic resonance (NMR) coupled with dynamic simulated annealing, is very similar to that of echistatin alpha1 which differs from echistatin gamma by 8 residues. In particular the two important sites of the Arg-Gly-Asp (RGD) loop and the C-terminal Lys45, both of which show some degree of disorder, are maintained in similar spatial orientation and proximity as those in echistatin alpha 1 even without the constraint provided by the disulfide bond of the (Cys8-Cys37) pair. These results provide new insights in further defining distinct structural features of echistatin gamma, which are involved in supporting the active polypeptide conformation to achieve biological activity in the absence of one pair of disulfide bonds.


Subject(s)
Computer Graphics , Disulfides/chemistry , Magnetic Resonance Spectroscopy , Peptides/chemistry , Platelet Aggregation Inhibitors/chemistry , Amino Acid Sequence , Chemical Phenomena , Chemistry, Physical , Intercellular Signaling Peptides and Proteins , Models, Molecular , Molecular Sequence Data , Protein Structure, Tertiary
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