Preliminary crystallographic analysis of cardiotoxin V with major fusion activity from Taiwan cobra (Naja naja atra) venom

Crystals of a cardiotoxin from Taiwan cobra venom have been obtained by the vapor diffusion method using methyl pentanediol as precipitant. The crystals belong to the hexagonal space group P6(1)22 (or P6(5)22), with cell dimensions a = b = 47.5 A, c = 111.3 A, alpha = beta = 90 degrees and gamma = 120 degrees and diffract to a resolution of 2.2 A. There is one molecule per asymmetric unit and the solvent content is estimated to be 53%.

A non-natural dinucleotide containing an isomeric L-related deoxynucleoside: dinucleotide inhibitors of anti-HIV integrase activity

The first X-ray crystal structure of a non-natural dinucleotide, 5'-O-phosphoryl-1'-deoxy-2'-isoadenylyl-(3' --> 5')-cytidine 6.5-hydrate (pIsodApC), C19H26N8O13P2 x 6.5H2O, belonging to a family of dinucleotides that contain an isomeric nucleoside component, is described. A complex system of hydrogen bonds between water molecules and various sites on the dinucleotide was found. All H atoms were located from electron-density difference maps, which allowed identification of protonation sites. Compounds of this family have been found to bind at the active site of HIV integrase and to be inhibitors of this key viral enzyme. These dinucleotides are completely resistant to cleavage by exonucleases; an abnormal dihedral angle twist in an internucleotide phosphate bond revealed in the X-ray crystal structure may be contributing to this unusual stability towards nucleases.

Improved crystals of the toxic protein MAP by protein engineering towards the host specificity

Mirabilis anti-viral protein (MAP) is a ribosome-inactivating protein from Mirabilis jalapa L. Since MAP is effective over a broad spectrum of species, the protein is difficult to express in heterologous hosts such as Escherichia coli. Recently, we obtained a MAP mutant, Y72F which exhibits a lower (1/100) activity against E. coli ribosomes while retaining almost full activity against mammalian cells [Habuka, Miyano, Kataoka, Tsuge & Noma (1992). J. Biol. Chem. 267, 7758-7760]. For the crystallographic studies, the Y72F MAP expression vector with an OmpA leading sequence was constructed and expressed in E. coli. The Y72F MAP mutant was then isolated and purified from the cell culture medium. Crystals were grown using the crystallization conditions for the native MAP crystals [Miyano et al. (1992). J. Mol. Biol. 226, 281-283]: 50% ammonium sulfate containing 50 mM ammonium citrate and 2 mM adenine sulfate, pH 5.4. The crystals belong to space group P3(1)21 (or P3(2)21) with a = b = 104.1 and c = 134.3 A. The crystals are isomorphous with the wild-type crystals but diffract to higher resolution. Imaging-plate photographs of the Y72F mutant showed sharp intense spots without the streaking observed in the native crystals.

Effect of intracarotid administration of morphine and naloxone on plasma vasopressin levels and blood pressure in the dog

The effects of intracarotid injection of morphine and naloxone on plasma vasopressin levels and arterial blood pressure were examined in pentobarbital-anesthetized dogs. Morphine administration decreased blood pressure in a dose-dependent fashion with a threshold between 10 and 50 micrograms/kg. Plasma levels of vasopressin rose in parallel with the decrease in blood pressure and were significantly elevated after doses of 50 and 100 micrograms/kg of morphine. Intracarotid injection of the opioid antagonist naloxone (1 mg/kg) increased blood pressure slightly, but significantly, and increased plasma concentrations of vasopressin approximately 60%. Pretreatment with naloxone did not blunt the hypotensive effect of morphine at a dose of 50 micrograms/kg, but enhanced the secretion of vasopressin in response to the morphine stimulus; plasma vasopressin levels were 5-fold greater than those found in animals given morphine but not pretreated with naloxone. Pretreatment with the histamine receptor blockers chlorpheniramine and cimetidine blunted morphine-induced (50 micrograms/kg) hypotension by about 50% and prevented a significant increase in the plasma vasopressin concentration. The data are consistent with the hypothesis that stimulation of vasopressin secretion by systemically administered morphine is secondary to the blood pressure fall. However, it also appears that, in the pentobarbital-anesthetized dog, naloxone-sensitive systems exert a tonic inhibitory influence over both vasopressin secretion and blood pressure.

[Clinical significance of the preoperative neutrophil lymphocyte ratio in the evaluation of the prognosis of laryngeal carcinoma]

OBJECTIVE

To explore the effect of preoperative neutrophil lymphocyte ratio (NLR) on the prognosis of patients with laryngeal carcinoma.

METHODS

Clinical data of 202 patients with laryngeal carcinoma treated from January 2004 to October 2009 were retrospective analyzed to determine the optimal critical value of NLR. To study whether NLR is an independent factor affecting the recurrence and 5-year survival rate of patients with laryngeal cancer after surgery, single factor and multivariate analyses were performed. The factors included age, gender, T stage, pathological differentiation, lymph node metastasis, primary tumor site and NLR value. The relationship between NLR and cervical lymph node metastasis was analyzed.

RESULTS

The optimal critical value of NLR was 2.85, by which cases were divided into high NLR group (NLR≥2.85) and low NLR group (NLR<2.85). Single factor and multivariate analyses indicated that T staging, lymph node metastasis, primary tumor location, and NLR were the independent factors affecting the recurrence of laryngeal carcinoma. T stage and lymph node metastasis were the independent factors affecting 5-year survival rate of laryngeal carcinoma. The increase of NLR value increased the rate of cervical lymph node metastasis.

CONCLUSION

Preoperative NLR level influences the recurrence and cervical lymph node metastasis of laryngeal carcinoma and can be considered a prognosis factor of laryngeal cancer.

Distribution of 3H-morphine after lumbar epidural administration in unanesthetized rabbits

BACKGROUND AND OBJECTIVES

This study focused on the distribution of 3H-morphine in the spinal cord, roots, urine, and blood, after epidural administration in rabbits.

METHODS

Under nitrous oxide, halothane, and oxygen endotracheal anesthesia, the cisterna magna of New Zealand albino rabbits was cannulated for cerebrospinal fluid sampling, and catheters were placed in the lumbar epidural space. Through the epidural catheter, 200 pmol of 3H-morphine contained in 500 microliters of 1.3 mM (0.21 mg) morphine was injected. Arterial blood and cisternal CSF were sampled at 0, 5, 15, 30, 45, 60, 90, and 120 minutes after injection. Animals were killed with intravenous pentobarbital at the end of 120 minutes (n = 3), 6 hours (n = 4), and 12 hours (n = 2). In each animal the brain, spinal cord, spinal roots, liver, kidneys, and urinary bladder were removed.

RESULTS

The injection site over the cord was identified and all tissues were immediately frozen at -70 degrees C. Two-mm thick cross-sections, were taken from every centimeter of the spinal cord. Radioactivity in the series of sections was determined by scintillation spectroscopy. At 2 hours, 4.2% +/- 1.1% of the injected radioactivity was recovered, and at 6 hours 1.6% +/- 0.6% was recovered. Radioactivity was concentrated mainly around the lumbar injection site, and it decreased as the distance increased from the injection site and coincided with elapsed time after the injection.

CONCLUSION

Multiple linear regression analysis of radioactive labels showed the significant effect of time, distance from the injection site, and the time-distance interaction on the distribution of 3H-morphine in the spinal cord (p < 0.0001 for time and rostral and caudal distance from the injection site; and p < 0.0001 for interaction between time and distance.) A major portion of the injected radioactivity was recovered in the urine and a small amount in other tissues and body fluid: bladder, liver, spinal roots, kidney, plasma, and cerebrospinal fluid.

Increased phosphorylation of DARPP-32 by D1 agonistic action of l-stepholidine in the 6-OHDA-lesioned rat striatum

In order to explore the characteristics of l-stepholidine (SPD) activating the postsynaptic D(1) receptors, the effects of SPD on DARPP-32 phosphorylation in vivo with back-phosphorylation assay and on the postsynaptic D(1) receptor densities with radioligand assay were observed in the striatum of 6-OHDA-lesioned rat. The results showed that following subcutaneously administration of 20 or 40 mg/kg SPD for 21 d, (32)P phosphate incorporation into the DARPP-32 protein in the denervated striatum showed a 50% reduction (P<0.01) vs the intact striatum, indicating an increase of DARPP-32 phosphorylation in vivo in the denervated striatum. However,the D(1) receptor B(max) was decreased from 385.0+/-26.1 to 319.7+/-20.1 fmol/mg protein. It is suggested that D(1) agonist action of SPD decreases the D(1) receptor density but increases the phosphorylation of DARPP-32 in the striatum of 6-OHDA-lesioned rat, which may be responsible for the regulation of D(1) receptor signal transduction in brain neurons.

[Genescan analysis of the loss of heterozygosity on the long arm of chromosome 6 in non-small cell lung cancer]

To investigate if there are microsatellite loci in the long arm of chromosome 6 that have close relationship with non-small cell lung cancer, Multiple PCR approach was used to analyze the 36 loci in the long arm of chromosome 6. The PCR products were analyzed in PAGE and then the electrophoresis maps were analyzed with Genescan and Genotyper. There is different LOH frequency in different loci. The total frequency of LOH in 41 lung cancers was 78%(32/41), with the highest frequency of LOH was detected on the locus D6S302(75%). There are 14 loci which have LOH frequency more than 20% and the loci are mainly located in 2 regions: 6q16.3-q21 [6 loci D6S458 (21.43%), D6S1694 (26.92%), D6S1717 (35.71%), D6S1565 (40%), D6S302 (75%), D6S1706 (36.36%) and 6q26-q27 (5 loci D6S1550 (38.46%), D6S264 (20%), D6S1585 (25%), D6S446 (33.33%), D6S281 (30.77%)], There may be tumor suppressor genes located in the two regions, which have a close relationship with non-small cell lung cancer.

Double-loop locking cross-stitch suture and suspension fixation for medial collateral ligament origin reconstruction

The purpose of this study was to summarize the clinical application and results of the double-loop locking cross-stitch suture and suspension fixation method for medial collateral ligament origin reconstruction. Thirty-six patients (21 males, 15 females) with an average age of 40 years (range = 17-58 years), who underwent treatment for acute fracture of the medial collateral ligament at our hospital from February 2008 to May 2009, were included in this study. All patients presented unilateral injuries (17 right-sided, 19 left-sided) and underwent repair with the double-loop locking cross-stitch suture and suspension fixation method. All incisions in this group of patients healed by first intention. Thirty-two patients were followed up for 6-20 months (average = 12 months). There were no reports of wound infection, ligament re-fracture or other complications in the follow-up period. Based on the Lysholm knee-scoring scale, the patients received a 100% excellent and good rating (20 patients - excellent score, 12 patients - good score) postoperatively. The advantages of the double-loop locking cross-stitch suture and suspension fixation method are a smaller incision, reliable fixation, and early restoration of knee joint stability. It is, therefore, an effective and low-risk method for the reconstruction of medial collateral ligament origin.

[The value of preservation of subvalvular structures in patients with mitral and aortic valve replacement surgery and its effect on left ventricular contractility]

Objective: To discuss the clinical value of preserving subvalvular structure in mitral and aortic valve replacement surgery and its effect on left ventricular contractility. Methods: A total of 97 patients who underwent mitral valve replacement surgery in the Adult Cardiac Surgery of Heart Center of Henan Provincial People's Hospital, Central China Fuwai Hospital from June 2016 to December 2018 were selected as the research subjects, of whom 45 cases were preserved subvalvular structure and 52 cases were in the total resection group (intraoperative total resection of the mitral valve and subvalvular chordae tendineae). General cardiac function indexes and left ventricular function quantitative indexes were compared before and in 3 months and 6 months after the operation of the two groups; The changes of the overall longitudinal strain of the long axis of the apex and the overall circumferential strain of the short axis of the left ventricle determined by the two-dimensional speckle tracking technology were compared before and after the operation. Results: The ages of the patients in the preservation group and the total resection group were (41.8±11.3) and (43.3±10.6) years old, respectively, and the male proportions were 58.0% (26 cases) and 44.0% (23 cases), respectively, with no significant difference (all P>0.05). The aortic occlusion time and cardiopulmonary bypass time of the patients in the preservation group were (57.8±4.5) and (78.6±6.7) min, respectively, which were longer than those in the total resection group [(48.1±4.4) and (48.1±4.4) min, respectively] (all P<0.05). The left atrial pressure of the patients in the preservation group at shutdown was (8.4±1.8) mmHg (1 mmHg=0.133 kPa), which was lower than that of the total resection group (11.3±2.5) mmHg (P<0.001). There were interaction effects between groups and time in regards to the left ventricular end-diastolic diameter ( LVEDD ), left ventricular ejection fraction ( LVEF ) and Tei index, as well as the strain rate of mitral annulus and left ventricular wall of interventricular septum of the preservation group and the total resection group (all P<0.05). LVEDD and LVEF of patients in the preservation group at 3rd month after operation were (44.7±4.0) mm and (45.5±4.2) mm, and at 6th months were (56.5±4.9)% and (58.8±5.0)%, respectively, all larger than (42.7±3.6) mm and (42.7±3.6) mm, (54.5±4.6)% and (56.3±4.8)% of the total resection group. The measured value of LVESD in the preservation group at 3rd month after surgery was (32.6±3.2) mm, which was greater than that in the total resection group (31.2±3.4) mm (P<0.05). The Tei index of patients in the preservation group at 3rd and 6th months after surgery were 1.0±0.2 and 0.8±0.2, respectively, which were lower than those in the total resection group 1.2±0.3 and 0.9±0.2 (all P<0.05). Conclusion: Preserving the subvalvular structure during mitral valve replacement surgery can better improve the patient's left ventricular function and left ventricular systolic capacity.

Chronic neurological deficits and Nesacaine-CE--an effect of the anesthetic, 2-chloroprocaine, or the antioxidant, sodium bisulfite?

Chronic neurological deficits have been described in patients after presumed accidental subarachnoid injection of 2-chloroprocaine-CE (Nesacaine-CE; N-CE) intended for epidural block. This study investigated the possible role of pure 2-chloroprocaine (2-CP) and sodium bisulfite, two components of Nesacaine-CE, in causing these complications when injected separately into the lumbar subarachnoid space of neurologically intact awake rabbits. Repeated 2-4-mg spinal anesthetic doses of pure 2-CP in lactated Ringer's solution did not produce chronic hindlimb paralysis even though accumulated doses reached 50 mg. However, 1.2-2.4 mg of sodium bisulfite, the antioxidant in N-CE added to prolong shelf-life, resulted in irreversible hindlimb paralysis in 12 out of 14 animals. This amount of bisulfite is contained in 12-24 mg of 2% N-CE. The demonstration that persistent paralysis resulted from low dosages of sodium bisulfite contained in commercially available 2-CP requires reevaluation of the suitability of this antioxidant for products prepared for intrathecal use.

[Role and mechanism of miRNA-181a in nonalcoholic fatty liver disease]

Objective: To investigate the role and probable mechanism of miRNA-181a in nonalcoholic fatty liver disease. Methods: HepG2 cells were treated with palmitic acid to construct a nonalcoholic fatty liver disease cell model, and the expression of miR-181a and lipidosis in the cells were measured. Transforming growth factor-β (TGF-β) was used to examine the effect of miR-181a expression in HepG2 cells. The miR-181a, lipidosis, reduced glutathione and reactive oxygen species (ROS) were determined by controlling and regulating the miR-183 expression levels after transfection with miR-181 mimics and inhibitors in HepG2 cells. The miR-181a target genes were predicted by bioinformatics analysis, and verified by real-time fluorescent quantitative PCR and western blotting. The independent sample t-test was used for the comparison between the two independent samples, and the comparison between multiple groups were accorded with the normal distribution, homogeneity of variance, and one-way analysis of variance. Results: Lipidosis was significantly increased after palmitic acid treatment in HepG2 cells, and the expression level of miR-181a was significantly increased than control group. After HepG2 cells were transfected with miR-181a inhibitors, the expression of miR-181a, triglycerides and reactive oxygen species were down-regulated, and reduced glutathione, predicting the mRNA and protein expression of target gene silencing information regulator 2 related enzyme 1 were up-regulated. However, the results were contrary to the above changes after transfection with miR-181a mimics. Conclusion: miR-181a participates in lipidosis and promotes lipid peroxidation in nonalcoholic fatty liver disease. miR-181a may affect the pathogenesis and progression of nonalcoholic fatty liver disease by inhibiting the expression of silencing information regulator 2 related enzyme 1.

Anesthetic hazards for patients who have undergone bilateral thoracolumbar sympathectomy

Abrupt and serious circulatory changes may take place during and after operations under general anesthesia in patients who have had extensive thoracolumbar sympathectomy performed previously. These changes should be anticipated and treated promptly and vigorously, if prevention is not possible. Experiences with 23 such cases are presented.

Canine renal responses to atrial stretch or intravenous saline are not attenuated at night

Primates develop a diuresis and natriuresis in response to stimuli that increase central blood volume. However, the renal response is markedly attenuated when these same experimental stimuli are applied at night. The purpose of the present study was to determine whether a quadruped, specifically the dog, also demonstrates attenuated renal responses to similar stimuli given at night. Two experimental protocols were performed on conscious dogs at night: 1) left atrial distension by partial mitral valve obstruction and 2) intravenous saline administration. Results from these experiments were compared with results from comparable experiments performed on the same dogs during the day. Each experimental intervention produced increases in urine flow and sodium excretion and decreases in urine osmolality during both day and night experiments (all P less than 0.05). The responses obtained during the night did not differ significantly from those obtained during the day. Thus the dog does not demonstrate an attenuated renal response to central volume expansion during the night. This contrasts with the adaptive response in primates that serves to minimize fluid loss when the intrathoracic blood pool is increased during prolonged recumbency at night. Presumably quadrupeds, with trunks horizontal both day and night, do not require nocturnal adaptive mechanisms to conserve body fluids.

Factors influencing the secretion of vasopressin into cerebrospinal fluid

Vasopressin (VP) has been found in the cerebrospinal fluid (CSF) of several species of animals. Although it is known that hemorrhage, hypertonicity of body fluid, hypoxia, and hypercapnia all increase VP in plasma, little is known regarding the stimuli that cause the secretion of VP into the CSF. We therefore performed several studies to examine whether stimuli capable of increasing plasma levels of VP can also increase VP in the CSF of anesthetized dogs. We found that hemorrhage, intracerebroventricular infusion of hypertonic artificial CSF, hypoxia, and hypercapnia all produced increases in the concentration of VP in plasma and in CSF, but the time courses and the magnitude of the increases in the two compartments were different. In addition, an i.v. infusion of hypertonic saline or of hydrochloric acid produced an increase in plasma VP without significantly changing CSF VP. Thus, although the secretion of VP into plasma and CSF may be influenced by the same stimuli, changes in one compartment do not necessarily correlate with changes in the other. Taken together, our results are consistent with the hypothesis that the plasma and CSF VP may derive from different sources.