Postprandial induction of chaperone gene expression is rapid in mice.

Molecular chaperones assist in the biosynthesis and processing of proteins. Most chaperones are induced by physiological stresses. We have shown that dietary energy restriction decreases the mRNA and protein levels of many endoplasmic reticulum chaperones in the livers of mice. Here, we have investigated the response of chaperone mRNA to feeding. Control and 50% energy-restricted C3B10RF1 mice were deprived of food for 24 h, fed, and killed 0, 1.5, 5 or 12 h after feeding. Chaperone mRNAs were strongly induced as early as 1.5 h after feeding in control and energy-restricted mice. The integrated levels of these mRNA over 24 h were significantly lower in energy-restricted mice. The mRNA response to energy intake was mirrored over the course of days in the level of chaperone protein. A similar but smaller response to feeding was found in kidney and muscle. Puromycin and cycloheximide failed to inhibit the feeding response, suggesting that feeding releases chaperone expression from an unstable inhibitor. Studies with dibutyryl-cAMP- and glucagon-supplemented, normal and streptozotocin-diabetic mice suggest that glucagon and insulin may be mediators of the feeding response. Adrenalectomy enhanced the feeding induction, but dexamethasone administration had no effect. Thus, postprandial changes in insulin and glucagon may link chaperone gene expression to feeding, possibly in several tissues including liver.     

Choice of an ovarian stimulation protocol according to the follicular puncture method in an in vitro fertilization programme

In order to ascertain the adequacy of ovarian stimulation protocols with a type of follicular puncture, 126 women undergoing in vitro fertilization received either combination clomiphene/hMG or hMG alone according to a randomized test protocol. Within both groups patients for whom a pelvic examination was required had laparoscopies, while others had transvaginal ultrasonically guided punctures as far as possible. Clomiphene/hMG was more efficient than hMG alone as assessed from the cleavage rate (68% vs. 54%; p less than 0.01) and the pregnancy per attempt rate (16% vs. 5%; p less than 0.05). Laparoscopic punctures were more efficient than ultrasonically guided punctures (mean number of recovered oocytes: 4.8 +/- 2.6 vs. 3 +/- 2.5; p less than 0.001), but slightly better results were achieved by this latter method in ongoing pregnancy per puncture rate (18% vs. 8%; NS). With ultrasonically guided punctures, stimulation by clomiphene/hMG allowed better oocyte recoveries (3.8 +/- 2.5 vs. 2.3 +/- 1.9, p less than 0.05). Such results constitute an argument for preferential use of the clomiphene/hMG stimulation protocol with ultrasonically guided punctures.     

Intracellular Ca2+ suppressed a transient potassium current in hippocampal neurons

The effects of intracellular Ca2+ (Ca2+i) on K+ currents in hippocampal cells were examined using acutely isolated cells obtained from adult guinea pigs. Whole-cell voltage-clamp recordings were carried out in a configuration that allowed a continuous perfusion of the intracellular medium. Recording media were made to block inward currents and allowed selective activation of K(+)-dependent outward currents. Voltage-dependent outward currents consisted of an initial rapidly decaying component followed by a sustained component. The time constant of decay of the transient current was about 25 msec, and previous studies (Numann et al., 1987) showed that the kinetic and pharmacological properties of this current closely resembled the A current recorded in invertebrate neurons (Connor and Stevens, 1971; Thompson, 1982). Intracellular perfusion of hippocampal cells with a solution containing elevated Ca2+ (about 4.5 x 10(-4) M) elicited outward currents at the holding potential (-45 to -55 mV) and produced changes in voltage-dependent K+ currents. The transient outward current (IA) activated by depolarization was suppressed with increases in Ca2+i. Delayed, sustained K+ currents were greatly potentiated. Data also showed that, among the 3 effects elicited by Ca2+i, suppression of IA was most sensitive to Ca2+i elevation. Previous results (Numann et al., 1987) showed that IA had a lower threshold (about -45 mV) than sustained currents (about -40 mV). By using low levels of depolarization (-40 mV), IA can be selectively activated, and the suppressive effect of Ca2+i on IA was confirmed on the kinetically isolated IA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Persistent reversal of diabetes by transplantation of fetal pig proislets into nude mice

Facing the limited availability of human adult and fetal pancreases, fetal pig proislets (pancreatic islet precursors) were investigated in view of several inherent advantages. Six litters of fetuses of mean +/- SE gestational age 75 +/- 3 days were obtained from commercially available farm pigs. Pancreatic tissue was gently digested with collagenase, then a 10-day culture was performed. During culture, fetal proislets showed no insulin response to glucose alone but a significant response to glucose plus theophylline. The insulin content per microgram of DNA in the cultured proislets continuously increased. Histological examination by immunoperoxidase staining showed that, apart from single insulin- and glucagon-positive cells, there were no discrete islets in the pancreatic tissue and the cultured proislets. Diabetes was induced with streptozocin (STZ) in eight nude mice 3-4 wk after proislet transplantation and in another eight nude mice without transplantation. During the initial week, blood glucose levels of mice in both groups increased rapidly. The mean +/- SE peak value of blood glucose levels in the transplanted group was 20.4 +/- 2.0 mM and was 20.1 +/- 1.3 mM in the group without transplantation. Simultaneously, body weight decreased from 29.5 +/- 0.7 to 21.5 +/- 0.9 g and from 27.9 +/- 0.7 to 19 +/- 1 g in the groups, respectively. Afterward, blood glucose levels of mice in the transplanted group gradually decreased, and normoglycemia was achieved in all mice within 50 +/- 13 days after injection of STZ, i.e., 74 +/- 13 days after transplantation. The group without transplantation persistently maintained blood glucose levels greater than 16.7 mM.(ABSTRACT TRUNCATED AT 250 WORDS)     

Laparoscopic Local Resection Based on Sentinel Node Evaluation for Early Gastric Cancer: A Preliminary Report

We previously reported that lymphatic mapping using isosulfan blue can be used to identify sentinel nodes (SNs). This study was undertaken to evaluate the feasibility of using the SN technique in treating early gastric cancer and to explore its usefulness for minimal invasive surgery. Twenty-three patients with early gastric cancer who underwent SN biopsy were retrospectively evaluated. Based on SN evaluation, individualized surgery was performed in five patients with T1N0M0 gastric cancer. When pathological examination of frozen sections revealed metastasis in SNs, we performed a standard D2 gastrectomy. Laparoscopic local resection was applied when the SN biopsy was negative. Our results showed that the success rate with SN biopsy in early gastric cancer was 100%, as were the accuracy, sensitivity, and specificity. All five patients with early gastric cancer had SNs negative for metastases both by frozen section and by postoperative pathology. Thus, all these patients underwent laparoscopic local resection without extended lymphadenectomy. We conclude that SN biopsy is a useful tool to individualize the operative procedure, and laparoscopic local resection can be safely performed using SN guidance in selected patients with early gastric cancer.     

重症胆管炎23例临床治疗分析

目的：探讨急性重症胆管炎患者的手术时机和死亡原因。方法：回顾性分析23例急性重症胆管炎患者的治疗及预后情况。结果：死亡2例（手术死亡及传统治疗死亡各1例）。早期大剂量短期应用糖皮质激素患者休克得到纠正率85％，明显高于未用糖皮质激素患者休克纠正率50％。结论：急性重症胆管炎患者应在出现休克和（或）精神症状之前手术，对已出现休克的患者，应先给予充分的保守治疗，待病情稳定后再手术。贻误手术时机，严重合并症如多器官功能衰竭及高龄是死亡的主要原因。