[Safety and efficacy of adjuvant chemotherapy with oxaliplatin and S-1 for patients with locally advanced gastric cancer after D2 lymph nodes dissection].

Objective: To investigate the safety and efficacy of oxaliplatin combined with S-1 (SOX) as adjuvant chemotherapy after D2 radical gastrectomy for locally advanced gastric cancer. Methods: A descriptive case series study was applied. Case inclusion criteria: (1) locally advanced gastric cancer confirmed by endoscopic biopsy or surgical specimen pathology as gastric adenocarcinoma; (2) receiving D2 radical gastric resection followed by SOX regimen adjuvant chemotherapy. Case exclusion criteria: (1) postoperative pathological TNM stage I or IV; (2) acute complications and emergency surgeries; (3) receiving neoadjuvant therapy; (4) concurrent malignancies and complications compromising patients' treatment or survival; (5) without receiving adjuvant SOX chemotherapy. A total of 94 patients with stage II-III gastric cancer who underwent D2 radical gastrectomy and postoperative adjuvant SOX chemotherapy at department of Gastrointestinal Surgery, Peking University People's Hospital from January 2014 to December 2019 were retrospectively enrolled. Chemotherapy-related adverse events, overall survival (OS) and progression-free survival (PFS) were analyzed. Kaplan-Meier survival analysis was performed and log rank test was used to analyze the difference between groups. P<0.2 or clinically significant indicators in univariate analysis were included in Cox regression model for multivariate survival analysis. Results: Among these 94 patients, there were 65 males and 29 females with an average age of (58.2±12.1) years; 33 patients with hypertension, diabetes mellitus, or cardiovascular and cerebrovascular diseases, 11 patients with family history of gastrointestinal tumors; 59 patients with tumors locating in the antrum or pylorus, 16 patients in the gastric body, 19 patients in the gastric fundus or cardia; 29 patients underwent total gastrectomy, 5 patients underwent proximal subtotal gastrectomy, and 60 patients underwent distal subtotal gastrectomy. In this study, 73 patients (77.7%) completed at least 5 cycles of adjuvant SOX regimen chemotherapy. Grade 3-4 adverse reactions included thrombocytopenia (23.4%, 22/94), nausea and vomiting (18.1%, 17/94) and peripheral neurotoxicity (6.4%, 6/94). Eighty-nine patients (94.7%) completed follow-up with a median follow-up time of 32 months. The 3-year and 5-year OS rates were 89.8% and 83.7%, respectively, and the 3-year and 5-year PFS rates were 81.4% and 78.1%, respectively. Taking 5 chemotherapy cycles as the cut-off point, the 3-year OS rate and 3-year PFS rate were 72.2% and 53.9% in the adjuvant chemotherapy < 5 cycles group, and 93.7% and 87.1% in the adjuvant chemotherapy ≥5 cycles group, respectively; the differences were statistically significant (P=0.029, P=0.006). Univariate analysis showed that the adjuvant chemotherapy < 5 cycles group was associated with worse 3-year OS (P=0.029). Multivariate analysis showed that insufficient chemotherapy cycle (HR=9.419, 95% CI: 2.330-38.007, P=0.002) was an independent risk factor for 3-year OS. Meanwhile, univariate analysis showed that the adjuvant chemotherapy <5 cycles (P=0.006), preoperative CEA > 4.70 µg/L (P=0.035) and adjacent organ resection (P=0.024) were associated with worse 3-year PFS. Multivariate analysis showed that adjuvant chemotherapy <5 cycles (HR=10.493, 95% CI: 2.466-44.655, P=0.001) and adjacent organ resection (HR=127.518, 95% CI: 8.885-1 830.136, P<0.001) were independent risk factors for 3-year PFS. Conclusions: Oxaliplatin combined with S-1 as an adjuvant chemotherapy regimen for locally advanced gastric cancer has high efficacy and low incidence of adverse reactions. At least 5 cycles of SOX regimen adjuvant chemotherapy can significantly improve prognosis of patients with stage II-III gastric cancer.

[Controversy and consideration of high and low ligation of inferior mesenteric artery in radical resection of rectal cancer].

Radical resection is one of the most important treatment for rectal cancer, which requires not only removal of adequate bowel and mesorectum around the tumor, but also thorough lymphadenectomy. Besides, postoperative complications are surgeons' concerns as well. According to different ways to manage inferior mesenteric artery, procedures could be divided into two groups: inferior mesenteric artery (IMA) high ligation and low ligation, which lead to various outcomes of the extent of lymph nodes dissection, survival, preservation of intestinal blood supply, incidence of anastomotic leakage, and postoperative functions including defecation function, urinary function and sexual function. Author believes that for those patients with clinical stage T1, low ligation and D2 lymph nodes dissection could be considered. However, for patients with locally advanced carcinomas (clinical stage T2+or N+), especially suspicious metastasis of lymph nodes around IMA root, high ligation and D3 lymph node dissection is suggested to ensure en bloc resection. As for those patients with high risks for compromised intestinal blood supply, preservation of left colic artery plus D3 lymph nodes dissection might be a feasible way. Intraoperative indocyanine green fluorescent imaging might play a role in quality control of lymphadenectomy.

[Light and electron microscopic observation of zinc distribution in the carp retina].

Localization of zinc in the carp retina in both light and dark adaptation was investigated using neo-Timm sulfate silver method. The results showed that in light adaptation, zinc was preponderantly present in the outer plexiform layer (OPL). Both terminals of zinc containing photoreceptors and dendrites of bipolar cells usually extend into zinc staining areas in OPL. In dark adaptation, zinc staining in retina is blanched or only appeared in cytoplasmic bodies of few cones. There is no significant difference between dark and light adaptation in the zinc distribution in bipolar, amacrine and ganglion cells. The fact that zinc is perched in the carp retina between photoreceptors and second-order neurons of the visual pathways in OPL in light adaptation and significantly released in dark adaptation suggests that zinc might play some modulatory roles in the visual signal transduction.

Functional expression of a Ca2+-activated K+ channel in Xenopus oocytes injected with RNAs from the rat testis.

The present study investigated the feasibility of using Xenopus oocytes to express sperm ion channel by injection of RNAs extracted from the rat testis. The RNA-injected oocytes expressed an outwardly rectifying current which was dependent on K+ concentration and inhibitable by K+ channel blockers, charybdotoxin (CTX) and tetraethylammonium (TEA). The Ca2+ ionophore, ionomycin, could also stimulate current activation with similar current characteristics in the RNA-injected oocytes, suggesting the expression of a Ca2+-activated K+ channel. Immunolocalization indicated predominant Ca2+-activated K+ channel immunoreactivity associated with spermatogenic cells. Reverse transcriptase-polymerase chain reaction studies confirmed the expression of the Ca2+-activated K+ channel mRNA in isolated spermatogenic cells. Our results suggest that ion channels and/or receptors of spermatogenic cells could be investigated using the Xenopus oocyte as an expression system. The present study also suggests that sperm may possess a Ca2+-activated K+ channel which has been implicated in the process of sperm activation and gamete interaction.

[Zinc modulation of GABA receptors expressed in Xenopus oocytes injected with carp brain poly(A)+ RNA].

Two types of GABA receptors, GABAA receptors (approximately 85%) and GABAC-like receptors (approximately 15%), were expressed in Xenopus oocytes after injection of Poly(A)+ RNA with carp (Carassius carassius) brain. Using voltage-clamp technique and pharmacological methods, the effects of zinc on the two receptors were studied. It was found that zinc modulation of both GABAA and GABAC-like receptors by zinc was inhibitory and reversible with the former being stronger than the latter as indicated by a value of IC50 of 48.4 +/- 10.1 mumol/L against 255.6 +/- 21.5 mumol/L.

[Repression of voltage gated K+ channel expressed in Xenopus oocytes after injection total RNA from carp retina by an antisense oligonucleotide].

Injection of total RNA from carp retina induced the formation of a membrane K+ channel in Xenopus oocytes. We found an oligonucleotide complementary to the mRNA coding for a peptide fragment in the K+ channel of drosophila and mice could suppress the K+ channel current in a very specific manner. This provides important information for the cloning of this gene and for studying it's function.

[Studies on glutamate and GABA receptor expressed in amphibian oocytes after injection of carp retina mRNA].

Using voltage clamp and perfusion technique, the types and characteristics of amino acid receptors of carp (Carassius carassius) retinas were studied by expressed response of amphibian oocytes previous injected with the retinal mRNA. The results were as follows: (1) Glu receptor: Diazoxide could potentiated KA induced depolarization, suggesting that some of the retinal Glu receptors may be AMPA-preferring subtype. (2) GABA receptor: Bicuculine could greatly suppress the GABA induced inward rapid current, while GABAB agonist baclofen was without effect. This suggests that the most of retinal GABA receptors may be GABAA type.

[Blocking effects of benzyltetrahydropalmatine on delayed rectified K+ currents expressed in Xenopus oocytes and in toad oocytes].

The effects of benzyltetrahydropalmatine (BTHP) on delayed rectified K+ currents (Ik) expressed in Xenopus oocytes and Ik of toad (Bufo bufo gargarizans) oocytes were studied. The Ik expressed in Xenopus oocytes was measured after microinjection of mRNA isolated from carp fish (C anratus L.) brains with double -microelectrode voltage clamp technique. The maximum and mean value of Ik expressed in Xenopus oocytes were 600 nA and 360 +/- 104 nA, respectively. BTHP reduced the current amplitude of Ik expressed in Xenopus oocytes in 10-1000 mumol.L-1 dose-dependently, EC50 was 29 mumol.L-1. Also, the reduction of Ik of toad oocytes was 9.1%, 29.1%, 54.7% and 68.6% by BTHP 10, 30, 100 and 1000 mumol.L-1, respectively, EC50 was 33 mumol.L-1. The results showed that BTHP possesses an inhibitory effect on Ik, the main ion mechanism of antiarrhythmic action of BTHP.

Inhibition of left ventricular hypertrophy and expression of proto-oncogenes c-myc other than c-fos in myocardium by early captopril treatment in SHR rats.

AIM: To explore the mechanisms by which angiotensin converting enzyme inhibitor (ACEI) prevents the development of left ventricular hypertrophy (LVH). METHODS: Captopril (Cap 100 mg.kg(-1).d(-1)) was given orally to male spontaneously hypertensive rats from intrauterine period to 16 wk of age. Experiments were performed at 40 wk of age. SBP, left ventricular weight to body weight ratio (LVW/BW) were assessed. The levels of c-myc and c-fos mRNA in the left ventricle were measured by Northern blot. RESULTS: Early-onset Cap therapy significantly decreased SBP. After discontinuance of treatment for 24 wk, SBP of SHRcap was still maintained at a lower level. LVW/BW in SHRcap was markedly reduced. The expression of myocardial c-myc mRNA was decreased by 72% in SHRcap compared with that in the untreated SHR, but the expression of myocardial c-fos mRNA was not different between the untreated SHR, SHRcap, and WKY rats. CONCLUSION: Early Cap treatment may permanently prevent the development of hypertension, inhibit LVH. Furthermore, the prevention of LVH is associated with a decrease in c-myc mRNA levels, and the development and regression of left ventricular hypertrophy may be irrelevant to c-fos expression.

[Amino acid neurotransmitter receptors of carp brain expressed in amphibian oocytes].

GABA receptor and inotropic glutamate receptors were expressed in amphibian oocytes and studied with the voltage-clamp technique and pharmacological method after injection of mRNA from carp (Carassius carassius) brains. It was found that about 90% of the response to GABA was mediated by GABAA receptor, but there was also about 10% of the response which was insensitive to bicuculline, a selective antagonist to GABAA receptor, baclofen, a selective agonist to GABAB receptor, had no effect on the injected oocytes. These observations suggest the existence of GABAC receptor. Subtypes of glutamate receptors, including NMDA subtype, KA/AMPA subtype and metabotropic glutamate receptors were also expressed and the dose-response relations were studied. Furthermore, we found that NMDA competitively suppressed the current response to KA, suggesting that NMDA probably was a weak antagonist of the KA/AMPA receptor.

[Mechanism of inhibition in left ventricular hypertrophy by captopril treatment in spontaneously hypertensive rats].

To explore the mechanisms by which angiotensin converting enzyme inhibitor (ACEI) prevents the development of left ventricular hypertrophy (LVH), captopril (Cap 100 mg.kg-1/d was administered orally to male spontaneously hypertensive rats from intrauterine period to 16 weeks of age. Male and age-matched untreated WKY rats and SHR were used as controls. Experiments were performed at 40 weeks of age. SBP, left ventricular weight to body weight ratio (LVW/BW), myocardial hydroxyproline (Hypro) and norepinephrine (NE) were determined. The levels of c-myc and c-fos mRNA in the left ventricle were measured by Northern blot. Early-onset Cap therapy significantly decreased SBP at 16 weeks of age. After discontinuance of treatment for 24 weeks, SBP of SHRcap was still maintained at a level lower than that of untreated SHR. LVW/BW and Hypro in SHR cap were markedly reduced. The expression of myocardial c-myc mRNA (n = 5) was decreased by 72% in SHRcap compared with that in the untreated SHR, but the expression of c-fos mRNA (n = 7) and NE was not different between the untreated SHR, SHRcap and WKY rats. These results indicate that early Cap treatment may permanently prevent the development of hypertension, inhibit myocardial hypertrophy (MH), and interstitial fibrosis. Furthermore, the prevention of MH is associated with a decrease in myocardial c-myc mRNA levels, and the development and regression of MH may be irrelevant to proto-oncogene c-fos expression.

Study of microencapsulation for pituitary transplantation: capsule preparation and in vitro study.

We have developed microcapsules using sodium alginate (SA) and Poly-L-Lysine (PLL). A factorial design method of screening was chosen to study influences of different experimental parameters on size and stability of the capsules. We found that air flow affects initial size of the capsules significantly, while the molecular weight (MW) of PLL and incubation time have a positive impact on the expansion when capsules are incubated in sodium citrate (SC). When the capsules were continuously shaken in an attempt to mimic in vivo environmental conditions, those capsules made with optimal parameters (0.1% PLL, 42,000 MW, incubated for 6 minutes; 1.5% SA, incubated for 4 minutes; SC bath 4 minutes; 25# needle; air flow 14L/min) were still intact after 30 days and not totally ruptured until 90 days, while those developed with less strict parameters were ruptured within 2 hours in 50%. We also encapsulated human pituitary adenoma cells using PLL of 80,000 MW and cultured them for 9 days. Adenoma cells, both encapsulated or non-encapsulated, secreted the same amount of hormones. Our preliminary study suggests that selecting optimal combinations of experimental parameters is essential in developing durable microcapsules, which may be potentially used for pituitary transplantation in vivo.

[Glutamate receptor and GABA receptor expressed in amphibian oocytes after injection of chicken retina mRNA].

The glutamate receptor and GABA receptor of chicken retina were studied with the expression system of amphibian oocyte. Some important results were obtained: L-glutamate, kainate, AMPA and quisqualate could all induce rapid and smooth depolarizing currents in oocytes. NMDA, L-AP4, trans-ACPD and L-aspartate had no effects. The antagonism of kainate response by AMPA and quisqualate was found, and it seemed that AMPA, quisqualate and KA could act on the same receptor. Comparing the responses to L-Glu and NMDA, it was found that the mRNA abundance of metabotropic glutamate receptor and NMDA receptor in chicken retina was much lower than that of chicken brain. The GABA receptor in chicken retina was very different from that of bovine retina. And although about 10% of the GABA response was insensitive to bicuculline, but most GABA receptors in chicken retina were proved as GABAA receptors.

[Studies on glycine receptor, acetylcholine receptor and ion channels expressed in amphibian oocytes after injection of chicken retina mRNA].

Glycine receptor, acetylcholine receptor and voltage dependent ion channels expressed in amphibian oocytes after injection of chicken retinal mRNA were studied by using voltage clamp technique. The current response to glycine was proved as small, and the acetylcholine receptor was identified as N type. Aspartate, serotonin and dopamine induced no responses. In addition, voltage dependent ion channels were detected, and were identified as delayed rectifier potassium channel and sodium channel.

Study of microencapsulated pituitary transplantation. Preparation of the capsule and its property.

Microencapsules for pituitary transplantation was successfully developed with sodium alginate and poly-L-lysine (average molecular weight MW 70,000). The permeability of the capsular membrane (CM) was tested. The results showed that 60% of growth hormone (GH), thyroid stimulating hormone (TSH), prolactin (PRL) have passed through the membrane within 3 hours, and reached equilibrium up to 6 hours, suggesting that pituitary hormones (MW 20,000) could pass through CM freely. Bovine serum albumin (MW 67,000) in 50% could also permeate the CM in 3 hours and reached equilibrium up to 24 hours. While immunoglobulin (Ig, MW > 150,000) did not penetrate the CM completely. This study revealed that the microencapsular membrane we made effected immuno-isolation and could be used for pituitary transplantation.

Insulin stimulates the biosynthesis of chiro-inositol-containing phospholipids in a rat fibroblast line expressing the human insulin receptor.

HIRc-B cells (rat fibroblasts expressing the human insulin receptor) were incubated with myo-[3H]inositol for 48 hr, and the biosynthesis of chiro-[3H]inositol was investigated in the absence and presence of insulin following a time course up to 60 min. After phase separation, treatment with insulin for 15 min caused a 2.2-fold increase in the specific radioactivity of chiro-[3H]inositol-containing phospholipids in contrast to a 1.2-fold increase in the specific radioactivity of myo-[3H]inositol-containing phospholipids. No insulin-mediated change in the specific radioactivity was observed in the inositol phosphates or free inositols. Further detailed analysis of individual [3H]inositol-containing phospholipids demonstrated marked increases in specific activity of the chiro-[3H]inositol phospholipids after 15 min of incubation with insulin: phosphatidylinositol 4-phosphate and 4,5-bisphosphate, 4.2-fold; lysophosphatidylinositol, 1.5-fold; phosphatidylinositol, 3.2-fold. In contrast, myo-[3H]inositol-containing phospholipids demonstrated relatively small increases (1.1- to 1.4-fold) after 5 min of incubation with insulin. These findings indicate that insulin stimulates de novo synthesis of chiro-inositol-containing phospholipids at the inositol phospholipid level.

[A voltage-clamp study on voltage-gated calcium channels translated in Xenopus oocytes by rat brain mRNA].

Voltage-gated calcium channels, expressed in Xenopus oocytes after injection of rat brain mRNA, were studied by using voltage-clamp technique. The properties of the calcium channels were characterized by barium current (IBa) passed through the channels. All oocytes used in this study were taken from five identified donors. Endogenous voltage--activated barium current measured in most oocytes from these donors were not detectable, or smaller than 15 nA, mRNA was extracted from the whole brains of 10 day postnatal rats and microinjected into the oocytes. IBa increased gradually during five days after mRNA injection. The maximum amplitude of the expressed voltage-activated barium current was usually larger than one hundred of nA on the third day after mRNA injection. In comparison, the expression of voltage-activated barium current was hardly detectable in oocytes injected by mRNA extracted from brains of embryonic rats. The voltage-dependence of activation and inactivation pharmacology of IBa were studied. It was found that IBa was inhibited potently by lanthanide cations (La+3,Nd+3,Sm+3,Eu+3,Gd+3,Dy+3,Er+3) at mumol/L concentration level. L-type calcium channel ligands, nifedipine and Bay K 8644 inhibited IBa at 100 mumol/L, while another dihydropyridine ligand (+/-) nimodipine enhanced IBa at the same concentration.

[The expression of kainate and GABA receptors in oocytes of Bufo bufo gargarizans].

Oocytes of Bufo bufo gargarizans were used as an expression system for analyzing structure of exogenous membrane protein and their functions. Poly (A)+ mRNA isolated from rat brain was injected into Toad (Bufo bufo gargarizans) oocytes (50 ng/oocyte). Rat brain kainic acid and gamma-aminobutyric acid(GABA) receptors expressed by the injected mRNA were integrated in the oocyte membrane 48 h after the injection at 19 degrees C. Membrane currents induced by kainic acid (5 x 10(-5) mol/L) and GABA (10(-4) mol/L) were 294.0 +/- 6.4 nA (n = 5) and 309.5 +/- 4.9 nA (n = 4) respectively. The kainic acid induced current reached its maximum value at about 10(-3) mol/L. Moreover, it was observed that the 36Cl- influx of the oocytes microinjected with mRNA was one-fold more rapid than the control oocytes. These results indicate that the oocytes of Bufo bufo gargarizans as those of Xenopus laevis can be used to express membrane proteins (receptors & transports) to acquire their proper functions from exogenous mRNA.

[A voltage-dependent potassium channel of outward rectifier type in plasma membrane of oocyte from toad, Bufo bufo gargarizans].

Membrane properties of the fully-grown oocytes from toad, Bufo bufo gargarizans, were studied by using voltage-clamp technique. It was found that a sustained outward current was elicited by membrane depolarization to -30 mV or more positive value. The increase of the current was nearly proportional to the degree of depolarization. The peak value of the current ranged 2-5 microA at a membrane potential of 20 mV in oocytes from different toads. The current was inhibited by antagonists of potassium channel, TEA and 4-AP. The concentration of TEA capable of inhibiting half of the current was 2.6 mmol/L. Chloride channel antagonist 9-AC (2.5 mmol/L) had no effect on the current. Triple the extracellular calcium concentration did not show any effect either. The reversal potential of the current varied with an increase of 47.3 mV per decade change of the extracellular potassium concentration. Changing extracellular concentration of sodium or chloride did not shift the reversal potential. It was concluded that the outward current was a voltage-activated potassium current. The voltage-dependent potassium current decreased after treatment of the oocytes with progesterone to a state of maturation. A large decrease of the current (to about 1/20 of the control) occurred to the oocytes obtained from hibernating toads while a less striking decrease of the current (to about 1/3 of the control) was observed in the oocytes from toads all year round reared at 25-30 degrees C.

[Changes in lipid peroxides and superoxide dismutase as incubation of in vitro erythrocytes with cerebrospinal fluids and the action of various scavengers of free radicals].

In this experiment, LPO increased and SOD reduced as the time pass when erythrocytes (RBC) and CSF were mixed and incubated. There was a negative relationship between LPO and SOD. LPO in RBC of arterial blood was higher than that of venous blood after incubation for 3 days (P less than 0.01). When arterial RBCs were incubated together with various scavengers of free radical (SOD catalase and histidine and mannitol), the production of LPO was less than that of arterial RBC incubation singly (P less than 0.01). The change of LPO was not reduced when sodium nitrite and arterial RBC incubated. The results demonstrated that the scavengers of free radicals could be eliminated free radical but failed with sodium nitrite.