不同实体瘤体外药敏试验的可行性研究

目的：研究体外药敏试验用于不同原代培养肿瘤细胞的可行性,方法：采用MTT比色分析法,结果：非小细胞肺癌,食管癌,贲门癌对乐铂均较敏感,不同病理类型和同一类型的不同个体对乐铂的敏感性差异较大,且其抑制作 病理类型无密切关系。结论：MTTI地操作简便,快捷,敏感,可应用于实体瘤临床个体化的药敏检测。     

pH电极位置对反流性食管炎酸监测的影响

为探讨ｐＨ电极位置对反流性食管炎酸监测的影响,将６０例反流性食管炎随机分为对照（Ｃ）组和试验（Ｔ）组。 Ｃ组 ３０例用测压法将 ｐＨ电极置于下食管括约肌（ＬＥＳ）上缘 ５ ｃｍ处;Ｔ组 ３０例用 ｐＨ梯度法将电极放于胃食管连接处（ＧＥＪ）上方 ５ ｃｍ处。连续 ２４ ｈ ｐＨ监测。结果显示,Ｃ与Ｔ组前鼻孔至ＧＥＪ平均距离分别为（４６． ２±４．１） ｃｍ与（４６． ５±４． ５） ｃｍ,两者无明显差异（Ｐ＝０． ８）。两组前鼻孔至ＧＥＪ平均距离（４６． ３±４． ３） ｃｍ比 Ｃ组前鼻孔至ＬＥＳ上缘平均距离（４３． ３±３． １） ｃｍ低 ３． ０ ｃｍ（Ｐ＝０． ０００３）。食管酸监测的 ｐＨ＜４,总百分时间和总计分在Ｔ组（８．５和 ４５． ５）和Ｔ组中ＧＥＪ＞ＬＥＳ上缘＋３ ｃｍ和＜－３ｃｍ范围者（１０． ０和 ９９． ３）较Ｃ组（４． ８和 ２６． ３）均有明显增高, Ｐ均＜０． ０１）,而Ｔ组中ＧＥＪ≤ＬＥＳ上缘＋３ ｃｍ和≥－３ ｃｍ范围者（７． １和 ３９． ４）则无明显差异（ Ｐ均＞０． ０５）。研究结果表明,因 ＧＥＪ常比 ＬＥＳ上缘偏低,故以 ＧＥＪ安放电极（尤其是ＧＥＪ＞ＬＥＳ上缘 ＋ ３ｃｍ或＜－ ３ｃｍ范围者）对反流性食管炎行 ｐＨ监测时     

Nitric oxide mediates inhibitory nerve effects in human esophagus and lower esophageal sphincter

The effect of inhibition of nitric oxide synthase on nonadrenergic, noncholinergic nerve-mediated responses in circular smooth muscle of the human esophageal body and lower esophageal sphincter (LES) was examinedin vitro. Tissues were obtained from 10 patients (eight esophageal resection for cancer, two transplant donors). Muscle strips from the LES developed significant spontaneous tension (11.6 ± 2.1 mN/mm²,N=6) and relaxed in response to electrical stimulation. The nitric oxide synthase inhibitor,N -nitro-l-arginine (NNA), at 10^–5 M, inhibited the relaxation, but had no significant effect on the spontaneous tension (13.0 ± 2.6 mN/mm²,P=0.07). Esophageal body strips developed little spontaneous tension, demonstrated an off contraction following the cessation of the electrical stimulus, and when contracted with 10^–5 M carbachol, relaxed during electrical stimulation. NNA (10^–5 M) inhibited the off contraction and the relaxation seen after carbachol and unmasked a prominent intrastimulus contraction. This intrastimulus contraction was enhanced by eserine and inhibited by atropine and tetrodotoxin. NNA showed similar potency in the esophageal body and LES and its effects were reversed byl-arginine, but notd-arginine. The results indicate that nitric oxide is an important mediator for nonadrenergic, noncholinergic nerve effects in the human esophagus and lower esophageal sphincter.This research was supported in part by an ICI Pharma/Medical Research Council of Canada Research Fellowship grant awarded to H.G. Preiksaitis and a Medical Research Council Program Grant PG8.     

Influence of left ventricular filling proffle during preceding control beats on pulse pressure during ventricular premature contractions

We investigated whether the left ventricular filling profile,defined as the early to late diastolic left ventricular fillingvolume ratio, during the preceding control beats actually affectsthe pulse pressure during a ventricular premature contraction(PVC). Twenty patients underwent invasive electrophysiologicalstudy for sinus bradycardia. VPCs with various coupling intervalswere induced by right ventricular electrical stimulation, andthe mitral filling flow velocity pulsed Doppler echocardiography,the femoral arterial pressure curve and the electrocardiogramwere simultaneously recorded The early to late diastolic velocity-rimeintegral ratio (E₁/A₁ ratio) of the mitral filling flow velocityduring the control beats which preceded the VPC was measuredas an index characterizing left ventricular filling profile.The coupling interval of each VPC and the extrasystolic beatpulse pressure were measured The ratio of the extrasystolicbeat pulse pressure to the control beat pulse pressure was expressedin % (% extrasystolic beat pulse pressure). The correlationbetween the coupling interval and the % extrasystolic beat pulsepressure was investigated. Coupling intervals of 0·80,0·70, 0·60, 0·50, and 0·45 s wereused At a coupling interval of 0·80 or 0·45 s,the % extrasystolic beat pulse pressure showed no significantcorrelation with the E₁/A₁ ratio. In contrast, the % extrasystolicbeat pulse pressure with coupling intervals of 0·70,0·60, and 0·50 s showed a significant positivecorrelation with the E₁/A₁ ratio (r=0·67, 0·74,and 0·66 P<0·01, respectively). In additionto the prematurity and the site of origin of the VPCs, the leftventricular filling profile during the preceding control beatsmay significantly affect the height of the pulse pressure duringextrasystoles with medium length coupling intervals.     

Velocity of peristaltic propagation in distal esophageal segments

Recent studies of the peristaltic pressure wave have suggested the presence of two sequential but overlapping contraction segments in the distal esophageal body. In this report, propagation velocity of esophageal peristalsis was determined in these segments in normal subjects (N=35) and in patients with high-amplitude peristalsis (nutcracker esophagus,N=25) to see if intersegment differences were present in the normal or abnormal setting. Velocity measurements were made from conventional manometric tracings in two 4-cm regions representing the distal smooth-muscle segments. A novel method of velocity measurement was employed that used regression lines established from contraction onset times. In normal subjects, propagation velocity decreased significantly from the proximal to distal segment (4.9±0.5 cm/sec, vs 3.2±0.2 cm/sec,P<0.01). Velocity also decreased across segments in nutcracker-esophagus patients (5.3±0.6 cm/sec, vs 3.6±0.7 cm/sec,P=0.06), but the difference reached statistical significance only when the subset with highest amplitudes (180 mm Hg) was analyzed separately. Greater variance in velocity in the distal smooth-muscle segment of nutcracker-esophagus patients (P<0.01) was, in part, responsible for this statistical observation. We conclude that normal propagation velocity decreases across regions corresponding to the smooth-muscle contraction segments defined by recent studies of peristalsis, supporting the assumption that they represent separate neuromuscular units. The mechanisms responsible for contraction wave abnormalities in the nutcracker esophagus have a minimal effect on propagation velocity, an effect that is restricted to the distal smooth-muscle segment of the esophageal body.Supported in part by a grant from the United States Public Health Service (AM07130).     

Isovelocity investigation of the lengthening behaviour of the erector spinae muscles

The purpose of this study was to investigate the force-velocity (F/) relationship for the erector spinae muscles in submaximal activation movements, with particular attention to their response during lengthening movements and at lower shortening contraction velocities. Dynamic models that predict lower back muscle forces require reasonable representations of the modulating effect of instantaneous velocity. Ten males were observed performing trunk flexion and extension in the sagittal plane under constant load. Contraction velocities were measured as the first derivative from a devise sensitive to changes in spine curvature, and controlled by a visual feedback system while a constant load was applied through a chest harness. The erector spinae exhibited a yielding phenomenon which causes an abrupt drop in force during constant velocity stretching under constant, submaximal, stimulation. The findings were consistent with previous isovelocity muscle lengthening experiments. Yielding appeared dependent on the level of load/activation supporting the theory of a state-variableF/ relationship. The eccentric behaviour of the lower erectors (L3) seemed independent of velocity and length, while that of the upper erectors (T9) showed a dependence on length. At lower concentric velocities, concavity in torque-velocity curves was noted after a threshold velocity. The findings of this study strongly reinforce the notion that theF/ length relationship is not a continuous hyperbolic relationship during muscle shortening and that the commonly modelled force augmentation effect of lengthening is incorrect, at least for submaximal activation of the extensors of the lower back.     

Evidence against a role of nitric oxide in the indirect negative inotropic-effect of M-cholinoceptor stimulation in human ventricular myocardium

Nitric oxide (NO) has been reported to mediate several effects in response to muscarinic cholinergic stimulation in cardiovascular tissues. Recently, an attenuation of guinea pig cardiac myocyte contraction by NO has been described. The aim of the present study was to determine whether the indirect negative inotropic effect of M-cholinoceptor stimulation in human myocardium is in part due to an effect of endogenous NO. Therefore, the effect of carbachol was studied under control conditions and during inhibition of NO-synthase by pretreatment with N^G-monomethyl-l-arginine (NMMA). Functional experiments were performed in isolated, electrically driven (1 Hz, 37°C) left ventricular papillary muscle strips of human myocardium. Since cytokines have been reported to be increased in the serum of patients with heart failure and could induce NO-synthase activity in failing myocardium, we compared samples from nonfailing and terminally failing (classified as NYHA IV) hearts. The indirect negative inotropic effect of carbachol (10 mol/l) was studied in the presence of the \-adrenoceptor agonist isoprenaline (0.03 mol/l).After stimulation with isoprenaline, carbachol significantly (P < 0.05) reduced force of contraction. This effect was diminished in failing myocardium compared to nonfailing, probably due to the diminished inotropic response most likely due to the lower cAMP levels in response to \-adrenoceptor stimulation in the former condition. Pretreatment with NMMA (100 mol/l) altered the antiadrenergic effect of carbachol neither in nonfailing nor in failing preparations. Furthermore, inhibition of guanylyl cyclase, the target enzyme of NO, by preincubation with methylene blue (10 mol/l) for 30 min had no effect on the carbachol-induced decrease in force of contraction. Basal force of contraction, as well as the positive inotropic effect of isoprenaline remained unaffected by NMMA or methylene blue.The present study provides evidence that the indirect negative inotropic effect of M-cholinoceptor agonists is not due to an effect of NO in the human myocardium. Furthermore, the well known enhancement of cGMP in response to M-cholinoceptor stimulation appears not to be involved in this antiadrenergic effect.     

PCNA immunostaining combined with AgNOR staining in esophageal squamous cell carcinoma to identify patients with a poor prognosis

Immunostaining of the proliferating cell nuclear antigen (PCNA) provides important information about cell kinetics and is easily performed on routinely obtained formalin-fixed, paraffin-embedded materials. We report herein the results of a retrospective study on PCNA staining in esophageal cancer undertaken to determine its significance. As this study indicated that immunoreactivity was preserved in specimens fixed within 24 h, only 31 specimens from surgical patients were available for this investigation. The mean PCNA index of the patients without invasion to the adventitia (35.7±17.9) was significantly lower than that of those with invasion to the adventitia or neighboring structures (49.7±14.5), while the PCNA index did not correlate with other clinicopathologic parameters such as histologic type, lymph node metastases, or prognosis. However, when an analysis of PCNA staining was combined with an analysis of argyrophilic nucleolar organizer region (AgNOR) staining, a correlation with prognosis was found. In fact, seven patients with a high PCNA index (44) and AgNOR count (6) had a significantly poorer prognosis than the remaining 22 (P=0.0014), and six of these seven patients died within 2 years. These results indicate that this combined evaluation may be useful for the identification of patients with a poor prognosis among those undergoing surgery for esophageal squamous cell carcinoma.     

Early one-stage orthotopic jejunal pedicle-graft interposition in long-gap esophageal atresia

Since 1988, four children with long-gap esophageal atresia have undergone one-stage orthotopic jejunal pedicle-graft interposition at the age of 2 to 3 months. Obtaining enough jejunal length was no problem and major early complications did not occur. In one patient stenosis of the distal anastomosis was problematic and required corrective surgery. None of the patients demonstrated jejunitis as a result of gastroesophageal reflux. With follow-up periods of 12, 27, 46, and 60 months, all patients are doing well. It is concluded that the jejunum is a better esophageal substitute than is generally appreciated.     

食管癌术后一次性硬膜外注射和肌肉注射镇痛法的比较

目的：确定硬膜外一次性镇痛法对食管癌病人术后的镇痛效果和减少并发症的意义。方法：９３ 例病人随机分成实验组（ Ｔ 组,５１ 例） 和对照组（ Ｃ 组,４２ 例） , Ｔ 组于手术结束缝合皮肤切口时经硬膜外导管于 Ｔ６ － ７ 水平注射吗啡１ ｍｇ 加１ ％ 普鲁卡因１０ ｍｌ, Ｃ 组用阿片类药物肌肉注射镇痛。结果： Ｔ 组病人术后疼痛明显减轻,各种并发症显著下降。结论：硬膜外一次性镇痛效果确切,操作方便,副作用少,对降低术后心肺并发症很有意义,尤其对年龄大、心肺功能差的病人较适合。