Anin vitro electrophysiological study of the colon from patients with idiopathic chronic constipation

Preparations of the circular muscle layer from the sigmoid colon resected from patients with idiopathic chronic constipation were compared, at an electrophysiological level using the sucrose-gap technique, with preparations of the same region of the intestine resected from patients with rectal carcinoma. Non-adrenergic, non-cholinergic inhibitory neuromuscular transmission, represented by inhibitory junction potentials, was present in preparations from both groups. However, the inhibitory response in preparations from constipated patients had a slower or longer time-course than in those from cancer patients. Also, rebound activity following inhibitory transmission was observed in 34% of preparations from constipated patients but was observed in 67% of preparations from cancer patients. Preparations from both groups displayed the same patterns of spontaneous activity and the same proportion of each group was quiescent. The threshold for generation of action potentials and the passive resistance of the smooth muscle membrane were the same in both groups. However, quiescent preparations from constipated patients were less likely to discharge trains of action potentials when the smooth muscle membrane was depolarized than were preparations from cancer patients. These changes in transmission processes and excitability in tissue from constipated patients are discussed in relation to altered states of colonic motility found in people with idiopathic chronic constipation.     

Adenoma malignum (minimal deviation adenocarcinoma) of the cervix responsive to hormonal treatment

Adenoma malignum (AM) is a rare variant of cervical adenocarcinoma with an unfavorable prognosis despite radiation therapy, surgery, or chemotherapy either alone or in combination. Hitherto, however, the effectiveness of hormonal therapy for this condition has not been evaluated. We report on a patient with cervical AM treated with progesterone before surgery. The progesterone therapy resulted in a complete clinical response and partial surgical response. Later on the treatment was changed to tamoxifen because of side effects of the progesterone treatment. The patient is still without evidence of disease 42 months after the start of the hormonal therapy. The progesterone receptor analysis on the biopsy was clearly positive. This is, to our knowledge, the first case of an AM responsive to hormonal treatment. Furthermore, this is the first case of an AM with bone metastases at the time of primary diagnosis.     

Enhanced in vivo cytotoxicity of recombinant human tumor necrosis factor with etoposide in human renal cell carcinoma

Summary The combination of tumor necrosis factor (TNF) and etoposide (ETP) was evaluated for potential cytotoxic efficacy against a human renal cell carcinoma xenograft using an in vivo assay employing an athymic mouse host with tumor implanted a the subrenal capsule site. Both antitumor efficacy (relative survival or RTS) and toxicity (weight loss) of TNF and ETP alone and in combination were evaluated. While TNF and ETP alone were mildly inhibitory (RTS 90% and 71%, respectively), the combination caused marked tumor inhibition (45% of controls). Host toxicity encountered with the combination did not exceed the toxicity associated with ETP alone, suggesting that the therapeutic index may have been augmented. It is concluded that enhanced antitumor activity without substantial augmentation of toxicity is observed with this combination, providing a rationale for further evaluation of tumor necrosis factor-based regimens for the treatment of advanced renal carcinoma.Supported by a Merit Review grant, VA Medical Research Service, Durham, NC 27710, USA     

EFFECTS OF p53 GENE THERAPY COMBINED WITH CYCLOOXYGENASE-2 INHIBITOR ON CYCLOOXYGENASE-2 GENE EXPRESSION AND GROWTH INHIBITION OF HUMAN LUNG CANCER CELLS

Background Gene therapy by adenovirus-mediated wild-type p53 gene transfer has been shown to inhibit lung cancer growth in vitro, in animal models, and in human clinical trials. The antitumor effect of selective cyclooxygenase （COX）-2 inhibitors has been demonstrated in preclinical studies. However, no information is available on the effects of p53 gene therapy combined with selective COX-2 inhibitor on COX-2 gene expression and growth inhibition of human lung cancer cells. Methods We evaluated the effects of recombinant adenovirus-p53 （Adp53） gene therapy combined with selective CADX-2 inhibitor on the proliferation, apoptosis, cell cycle arrest of human lung adenocarcinoma A549 cell line, and the effects of tumor suppressor exogenous wild type p53 on COX-2 gene expression. Results Ad-p53 gene therapy combined with selective COX-2 inhibitor celecoxib shows significant synergistic inhibition effects on the growth of human lung adenocarcinoma A549 cell line. Exogenous p53 gene can suppress COX-2 gene expression. Conclusions Significant synergistic inhibition effects of A549 cell line by the combined Ad-p53 and selective COX-2 inhibitor celecoxib may be achieved by enhancement of growth inhibition, apoptosis induction and suppression of COX-2 gene expression. This study provides first evidence that the administration of p53 gene therapy in combination with COX-2 inhibitors might be a new clinical strategy for the treatment or prevention of NSCLC.     

VESICO-URETERIC REFLUX AND SURGICALLY TREATED PELVI-URETERIC JUNCTION OBSTRUCTION IN INFANTS UNDER THE AGE OF 12 MONTHS

Background : Pelvi-ureteric junction obstruction has been increasingly diagnosed in infants, mostly as a consequence of antenatal ultrasound examinations. Methods : Of 55 infants below the age of 12 months who underwent dismembered pyeloplasty over a 7-year period, we aimed to determine the patterns and outcome of associated vesico-ureteric reflux that was present in 15 (28%) of the 53 infants in whom follow-up was available. Results : A total of eight infants had resolution of their reflux with conservative management and the median time to resolution was 15 months. Five infants proceeded to ureteroneocystotomy. Conclusions : Given the association of vesico-ureteric reflux and pelvi-ureteric junction obstruction, routine cystography is recommended when the diagnosis of pelvi-ureteric junction obstruction is made.     

胃微小腺癌的组织发生研究

从２１０５例胃癌癌旁组织中找出微小腺癌３１例（〈０．１ｃｍ），观察其组织发生的特征，发现胃腺癌的发生有８种形式：①腺颈部干细胞癌变；②表面上皮癌变；③腺上皮癌变；④肠化生上皮癌变；⑤微腺囊癌变；⑥溃疡边缘上皮癌变；⑦扁平腺瘤癌变；⑧贲门交界处柱状上皮癌变。     

Niflumic acid-induced increase in potassium currents in frog motor nerve terminals: effects on transmitter release

The actions of the nonsteroidal antiinflammatory drug niflumic acid were studied on frog neuromuscular preparations by conventional electrophysiological techniques. Niflumic acid reduced the amplitude and increased the latency of endplate potentials in a concentration-dependent manner. Neuromuscular junctions pretreated with niflumic acid (0.05–0.5 mM) showed much less depression than control when they were stimulated with trains of impulses. Inhibition of acetylcholine release was reverted by raising the extracellular Ca²⁺ concentration but not by simply washing out the preparations with niflumic acid-free solutions. Pretreatment with indomethacin (0.1 mM), another nonsteroidal antiinflamatory drug, did not affect the niflumic acid-induced inhibition of evoked responses. Niflumic acid (0.1 mM) did not change the amplitude of miniature endplate potentials and had a dual action on the frequency of miniatures: it decreased their frequency at 0.1 mM whereas it produced an enormous increase in the rate of spontaneous discharge at 0.5 mM. Niflumic acid (0.1–1 mM) reversibly increased the amplitude and affected the kinetics of presynaptic voltage-activated K⁺ current and Ca²⁺-activated K⁺ current in a concentration-dependent manner. Niflumic acid (0.1–1 mM) irreversibly decreased the amplitude and reversibly affected the kinetics of the nodal Na⁺ current. Indomethacin (0.1 mM) had no effect on presynaptic currents. In conclusion, niflumic acid reduces acetylcholine release by increasing presynaptic K⁺ currents. This may shorten the depolarizing phase of the presynaptic action potential and may reduce the entry of Ca²⁺ with each impulse.     

Effect of β-endorphin on the contractile responses in mouse skeletal muscle

Tension development in response to direct and indirect electrical stimulation was studied in an isolated phrenic nerve hemidiaphragm preparation of the mouse. β-Endorphin (β-EP) caused an increase in the preparation of the mouse. β-Endorphin (β-EP) caused an increase in the response to low frequency stimulation of the nerve. Upon direct stimulation of the muscle the peptide had no effect. The actions of β-EP were abolished in the presence of the opioid antagonist naloxone and mimicked by β opioid agonists. Upon high frequency stimulation of the nerve, β-EP caused an increase in the initial, maximum, and mean tension. It also prevented the fall in the final tension seen in the control preparations with repeated periods of stimulation. The findings are consistent with β-EP having a role to improve neuromuscular function and deley fatigue, and indicate the possible therapeutic potential of opioid substances in conditions where muscle weakness is present. © John Wiley & Sons, Inc.     

Pulsing electromagnetic field stimulation of the in vitro growth plate

Specific pulsing electromagnetic fields (PEMFs) have been used to stimulate growth and repair of osteogenic tissues; however, the basis for this specificity is unknown. Previously, we determined the relevant electromagnetic field parameters of the clinically used PEMF and independently verified the beneficial effects of PEMFs on the rabbit fibula fracture healing model. The goal of the present study was to develop an in vitro model that would permit the effectiveness of various electric and magnetic field components of the PEMF to be determined. The costochondral junction (CCJ) of the 21-day-old rat was exposed in vitro to PEMFs with various electric and magnetic field component amplitudes. Response of this model to PEMFs was determined by nondestructive macrophotographic measurement of CCJ growth. Preliminary data indicated that temperature effects were present in this in vitro system. Subsequent experiments designed to separate the effects of temperature and PEMFs on the growth of CCJs in tissue culture were performed. Results indicate that accurate and frequent temperature measurements must be made for in vitro models being used to study effects of PEMFs. Small temperature differences induced by the coils used to produce PEMFs in the CCJ experimental system can have significant stimulatory effects, and the combined effects of temperature and PEMFs are not linearly additive in this model. Furthermore, our results suggest that thermal and PEMF stimuli could affect macrophotographically measured growth of the CCJ by separate mechanisms or could have a synergistic effect. Therefore, PEMF stimulation experiments should be performed under strictly "athermal" conditions.     

血管内皮细胞条件培养基促进胃癌细胞增殖和迁移

探讨血管内皮细胞培养基对胃癌细胞增殖和迁移的影响,分析血管内皮细胞调控胃癌细胞发生转移的机制。方法 设置对照组和共培养组,分别将正常培养基和人脐静脉血管内皮细胞HUVEC条件培养基作用于胃癌细胞HGC27,采用MTT法和划痕试验检测胃癌细胞HGC27的增殖活性和迁移能力。设置Control组、6 h组、12 h组和24 h组,以HUVEC的条件培养基作用于胃癌细胞6、12和24 h,Western blot检测EMT标志物和紧密连接蛋白的表达变化,激光共聚焦显微镜观察细胞骨架和紧密连接蛋白的分布变化。结果 MTT及划痕试验表明HUVEC条件培养基促进胃癌细胞HGC27的增殖和迁移。与Control组比较,间接共培养后胃癌细胞的形态呈间充质状改变,丝状伪足样凸起数量显著增加。 Western blot结果显示间接共培养后胃癌细胞上皮标志物E-cadherin表达水平逐渐下降,而间充质标志物N-cadherin和MMP-9逐渐增加,具有时序性变化规律。ZO-1和Occludin的表达也逐渐下降,细胞膜分布减少。结论 间接共培养下,血管内皮细胞通过上调胃癌细胞MMP-9,破坏紧密连接,促进胃癌细胞增殖和迁移