The influence of clinical intervention on pressure-volume relationships--the conductance (volume) technique. We analysed end-systolic pressure-volume relations (ESPVR), using the conductance technique, to study the potential inotropic effects of (1) PDE inhibitor drugs, (2) class 1 anti-arrhythmic drugs and (3) PTCA-induced myocardial ischaemia (MIS). The question of contractility involvement is of clinical importance, since with inotropy-induced rise in MVO2 there is a risk of MIS, should any of the cardiotonic drugs (amrinone, enoximone, piroximone) be used in patients with CAD. Accordingly, we analysed their haemodynamic effects, identified improved contractility as one factor of these drugs' mode of action and proved their inability to induce MIS. Anti-arrhythmic drugs may cause cardiodepression, a risk theoretically well recognized but clinically poorly defined. We monitored the haemodynamics of six class 1 anti-arrhythmic drugs and found that drug-induced moderate impairments of contractility (at rest and during tachycardia) proved significant, but clinically asymptomatic, and did not differ significantly from drug to drug. PTCA provides routine models of MIS in man. We analysed ESPVR and haemodynamics during MIS with PTCA and coronary angiography (CORO) and the induced diminished LV function during CORO v PTCA appeared quantitatively less. Inotropy impairment was rather modest during ischaemia: dP/dtmax was reduced by 11%, slope k of the ESPVR by 14%, while the EDV was increased by 67%. All changes were reversible about 90 s after PTCA balloon occlusion and 20 s after CORO.


Functional significance of the Frank-Starling mechanism under physiological and pathophysiological conditions. The functional significance of the Frank-Starling mechanism under physiological and pathophysiological conditions is discussed, based mainly on animal experiment results (in the dog, pig and rat). The dependence of individual stroke volume on end-diastolic volume can be described adequately using Frank's diagram. This can be illustrated by varying filling pressure (respiratory cycle, vascular tone in the capacitance system, body position, circulating blood volume) and by alterations in the duration of the filling period (heart rate and rhythm, rate of relaxation) and in ventricular compliance (wall thickness, fibrosis; contracture, rigor). The functional importance of the Frank-Starling mechanism lies mainly in adapting left to right ventricular output. During upright physical exercise an increase in end-diastolic volume due to the action of the peripheral muscle pump and increased venous tone can assist in enhancing stroke volume. Reduced contractility leads to a shift of the operating point to the right in the pressure-volume diagram, thus tending to prevent a decrease in stroke volume. However, the consequences of increased circulating blood volume in chronic heart failure are, as a rule, mainly detrimental (congestive symptoms; myocardial component of coronary resistance; cardiac energetics). Reduced contractility results in a flattening of the relation between stroke volume (or stroke work) and end-diastolic volume. Furthermore, the Starling mechanism is prevented from becoming effective if the sarcomere-length reserve is exhausted, or in the presence of inadequate sarcomere extension due to impaired relaxation or reduced distensibility of the ventricular wall. The latter is illustrated using the example of a dilated fibrotic left ventricle from a rat with experimental supravalvular aortic stenosis.


Comparison between preload recruitable stroke work and the end-systolic pressure-volume relationship in man. We compared linearity, inotropic sensitivity (using dobutamine) and afterload dependency (using captopril) of contractile indices derived from the end-systolic pressure-volume relationship (ESPVR) and preload recruitable stroke work (PRSW) in man. We investigated 60 patients, 39 with normal (EF > or = 50%, group 1) and 21 with decreased ventricular function (EF < 50%, group 2). Variably loaded P-V loops were constructed by conductance catheters with vena caval occlusions. The slopes of the ESPVR (Emax) and PRSW (Mw) were assessed by linear regression analysis. The correlation coefficients of the ESPVR (r = 0.964) and PRSW (r = 0.976) were both very high, but the Z-value of the ESPVR was lower than for PRSW. During the control period, normalized Emax and Mw were significantly higher in group 1 than group 2 (Emax: 4.6 +/- 2.3 vs 2.8 +/- 0.8 mm Hg ml-1 m-2, Mw: 109 +/- 31 vs 86 +/- 28 10(3) dyn cm-2. After dobutamine, Emax and Mw increased significantly both in group 1 (128% and 124% vs control respectively) and in group 2 (132% and 130% respectively). After captopril, the ESPVR tended to shift to the right with a decrease in afterload; PRSW was unchanged. We conclude that PRSW may be a more linear and reliable index for evaluation of contractility in man.


Assessment of myocardial oxygen consumption (Vo2) and systolic pressure-volume area (PVA) in human hearts. Several studies have recently reported that the relationship between myocardial oxygen consumption per beat (Vo2) and left ventricular (LV) systolic pressure-volume area (PVA), which represents total mechanical energy generated by contraction, is linear and independent of loading conditions in excised, supported, and intact hearts. We assessed the Vo2-PVA relationship in nine patients with heart disease. LV volume and pressure were measured simultaneously by conductance catheter and tip-micromanometer. Vo2 was calculated from the difference between arterial and coronary sinus oxygen content, and coronary sinus blood flow measured by the thermodilution method. We obtained the linear relationship between Vo2 and PVA by dextran infusions (median r = 0.917). The slope of the Vo2-PVA relationship was (1.82 +/- 0.66) x 10(-5) mlO2 mmHg-1 ml-1 and the contractile efficiency, the reciprocal of the slope of the Vo2-PVA relationship, was 40 +/- 13%. The Vo2 intercept, which reflects Vo2 for non-mechanical work, was 0.0284 +/- 0.0286 ml O2 beat-1. These results suggest that PVA is a good predictor of myocardial oxygen consumption and a powerful tool to evaluate the coupling of LV mechanical performance to energy use in human hearts.


Ventricular performance in relation to heart rate and AV delay at rest. The influence of heart rate (HR) and AV delay (AVD) on left ventricular haemodynamics was studied in 12 patients classified as having coronary heart disease (CHD), hypertensive heart disease (HHD), dilated cardiomyopathy (DCM) or who served as controls. Using the conductance catheter technique, haemodynamics were measured during pacing rates of 80 to 180 beat.min-1 at AV delays of 0 to 240 ms. A 3-D linear regression analysis of the data quantified the influence of HR and AVD in principle for each group. An increase in HR resulted in a rise in the cardiac index without changing ejection fraction in the control group only, but led to a decrease in these parameters in HHD and DCM; cardiac index remained constant in CHD. CHD patients frequently had a more pronounced left ventricular end-diastolic pressure (LVEDP) elevation with higher HR, whereas left ventricular end-diastolic volume (LVEDV) and stroke volume decreased. In patients with HHD, lengthening of the AVD resulted in an increase in LVEDV and a decrease in LVEDP and left ventricular end-systolic volume (LVESV) leading to a higher ratio of stroke volume to LVEDP than in the other subsets. In DCM, longer AVD also resulted in a higher SV/LVEDP ratio, but in contrast to HHD the influence of AVD variation on LVEDP and therefore on the LVEDV/LVEDP ratio was missing.


Haemodynamic analysis of atrioventricular tachycardia. The aim of the study was to delineate the influence of the ventriculo-atrial interval (VAI) in tachycardia with regard to the underlying heart disease. Haemodynamic studies were performed by the conductance catheter technique during paced tachycardia with a HR of 140, 160 and 180 beat.min-1 at various VAI in 10 patients; three with coronary heart disease (CHD), three with hypertensive heart disease (HHD) and four serving as controls. The influence of the VAI accounted for an overall change in cardiac index (CI) of 30 +/- 14%. Alterations in left ventricular peak systolic pressure (LVPSP) depending on VAI were significantly higher (P < 0.01) in CHD patients (32 +/- 9%) than in other groups (14 +/- 9% in the controls and 17 +/- 8% in HHD patients). The influence of VAI on left ventricular end-diastolic pressure (LVEDP) did not differ between the subgroups and accounted for a mean overall change of 32 +/- 14%. Atrial activation during the last third of the cardiac cycle led to the highest values of CI, LVEDP and LVPSP in the control group, whereas in HHD and CHD groups minimal values of CI were correlated with maxima of LVEDP and LVPSP. Conversely, with atrial activation during the medium third of the cardiac cycle minima of CI and LVEDP were observed in the controls, whereas in HHD and CHD patients the highest cardiac index coincided with the lowest LVEDP. Thus tachycardias have different haemodynamic effects depending on the nature of myocardial impairment and the timing of AV coupling.


How to prescribe and manage antiarrhythmic drug therapy. The pharmacological approach is the corner-stone of therapy for arrhythmia because it is non-invasive, convenient and widely available. However, the indications for antiarrhythmic therapy in general, as well as the indications for drug therapy as opposed to non-pharmacological therapeutic methods, are far from clearly defined. Among the existing antiarrhythmic drugs, clear reduction of mortality due to arrhythmia has been shown definitively only with beta-blocking agents and possibly with amiodarone.


Long-term follow-up after extracorporeal shock wave lithotripsy of large kidney stones. In 76 patients (53 women and 23 men) aged 24-92 years, extracorporeal shock wave lithotripsy (ESWL) was performed between June 1986 and December 1988 as monotherapy for large kidney stones (diameter > 2.5 cm). There were 41 complete and 24 partial staghorn calculi. The patients were treated with the Dornier HM3 lithotripter under sedoanalgesia. Of the 60 patients with large stones whose last ESWL treatment had been at least 24 months earlier, only 15 ultimately came for this long-term control check-up. Reports on 15 other patients were received from their doctors stating that the patients were doing well, not having new stone episodes. These subjects had to be excluded from final evaluation since they did not fulfill all requirements. Thirty patients had either moved out of the area or were from distant locations and therefore unable to appear. Creatinine was normal and urinalyses negative in these 15 patients; 12/15 were stone-free. The ones who were not had small remnants in the lower pole calices which did no harm at all. One patient already had elevated pretreatment blood pressure; 6/14 with normal blood pressure before ESWL showed elevated values 30 or more months after the last ESWL. Radioisotope examinations with separate clearance tests demonstrated no real evidence of loss of kidney function on the treated in comparison with the untreated side. Sonographic findings on the longitudinal and transverse diameter of the treated and untreated kidneys with regard to the total number of shock waves did not show marked differences as they all remained below the 9% limit.


Intravesical therapy of superficial bladder transitional cell carcinoma with tumor necrosis factor-alpha: preliminary report of a phase I-II study. A phase I-II trial of intravesical immunotherapy with tumor necrosis factor (TNF)-alpha in 24 patients affected by superficial bladder tumors is herein presented. Of these, 11 patients were submitted, at weekly intervals, after complete TUR, to 8 instillations of TNF-alpha at increasing doses from 50 to 600 micrograms. Tolerability was excellent, even at the highest dose. In a second group of 13 patients with a histologically proved papillary marker lesion, TNF-alpha was instilled at weekly intervals at the dose of 500 micrograms for 8 weeks. Three complete responses (23%) were obtained.


Corpus cavernosum invasion and tumor grade in the prediction of lymph node condition in penile carcinoma. Of the 101 patients with penile cancer, we have analyzed 66 from whom we had enough information: 42 (63.3%) patients with corpora cavernosa invasion (T2-3) and 24 (36.6%) without (T1). With respect to the tumor grade, in 36 (54.3%) patients it was well differentiated (G I), in 23 (34.8%) moderately (G II) and in 7 (10.6%) poorly differentiated (G III). We also analyzed the inguinal lymph node condition. Of the 66 patients, 28 (42.4%) developed nodal metastases, and 38 (57.6%) were considered free of nodal metastases and disease with an average follow-up of 76.2 months (range 38-192). The presence of metastatic nodes was influenced by both tumor stage and grade with significant differences between T2-3 and T1 (p = 0.001) and between G II-III and G I (p < 0.01), but each of them alone was not a sufficiently reliable predictive factor. In order to associate local stages and tumor grades in relation to the presence of metastatic nodes, we checked that none of the patients with T1, G I (group 1) developed nodal metastases, and therefore, 'wait and see' should be the suitable approach. Twenty (80%) of the patients with T2-3, G II-III (group 2) developed metastatic lymph nodes, thus, in this group, an early lymphadenectomy should be performed. In the remaining 22 patients with T1, G II-III and T2, G I (group 3), 8 (36.4%) showed metastatic lymph nodes; in this group, other factors such as age, cultural level and obesity should be taken into account when deciding on lymphadenectomy.


Role of penile nocturnal tumescence and rigidity measurement in the diagnosis of erectile impotence. Reviewing a group of 100 patients undergoing nocturnal penile tumescence and rigidity measurement (NPTR), we tried to define normal values and compared these results with those of other authors. We also tried to answer two important questions: Is an abnormal NPTR registration always a proof of biogenic impotence? Is a normal NPTR always a proof of psychogenic impotence?


Functional bladder neck obstruction in males: a progressive disorder? Functional bladder neck obstruction is often an elusive cause of outlet obstruction in males. If the entity escapes timely diagnosis and treatment, it may progress to acute or chronic retention, terminating in renal failure. The diagnosis can be accurately made by a synchronous pressure flow electromyograph (EMG) study. This is a report on 16 men under 45 years of age encountered during the past 2.5 years. A high sustained detrusor pressure (mean 157 cm H2O) during voiding with poor flow (mean 9.89 ml/s) was observed in all patients. External sphincteric activity during EMG and video study was found to be completely quiescent at the time of voiding. All these patients had inadequate funneling and bladder neck opening. Some of these patients had intermittent bladder neck opening. Three patients presented with renal failure. Following therapy, renal function could be reversed back to normal in 2 patients. Clean intermittent catheterisation, pharmacotherapy using alpha-blockers and endoscopic bladder neck incision were the modalities used to treat this group of patients.


Surgical correction of severe Peyronie's disease without plaque excision. We report 7 cases of severe Peyronie's disease treated with a modified surgical technique of the one described in 1989. This second version consists of making only one I-shaped incision on the dorsal face of the penis, in order to relax and create a defect in the tunica albuginea, which is then covered with a patch of human lyophilized dura mater. The plastic and sexual results were identical to the ones described previously, but the operative time was shortened. This type of surgery is indicated to correct severe angulation and shortening of the penis in men with normal sexual lives.


Original lithotomy positioning for transperineal extracorporeal shockwave lithotripsy for distal ureteric calculi with Tripter X1. Extracorporeal shockwave lithotripsy (ESWL) has been initially designed for stones located in the kidney and the upper ureter. Our lithotripter is no exception. Its components (the table and the orientation of the semi-ellipsoid reflector) are adapted for the treatment of kidney or lumbar ureter stones. However, the elements forming the unit of treatment (the table, the C-arm and the Tripter) can be modified in such a way that focalization of stones of the lower ureter becomes possible through a perineal exposure. The aim is to avoid the pelvic bone shield while a good focalization of the stone is realized. From June 1989 to March 1991, 35 patients were treated for distal ureteric stones by ESWL in this original positioning.


Posterior hypospadias repair: a new technical approach. Mobilization of the urethral plate and duplay urethroplasty. We describe our experience with a new technique of complete repair of severe posterior hypospadias in one stage. The operative technique includes some innovative points: penile straightening is realized by urethral mobilization (without detaching it from the glans) to excise the chordee, and then urethroplasty according to Duplay and glanuloplasty are performed. We report our preliminary results in 6 patients. They are interesting from a cosmetic and functional point of view.


Effects of high-energy focused ultrasound on kidney tissue in the rat and the dog. In vivo tissue destruction was performed on 124 rat and 16 canine kidneys by focusing high-intensity ultrasound with a 1- and 2.25-MHz transducer. A precise tissue lesion was obtained in both models which varied in size according to the number of firings and the acoustic intensity. In the rat experiments, which were used to define the constants necessary to produce a localized tissue lesion at the focus of the transducer, the lesions obtained were either coagulating necrosis or a 'punched out' cavity which represented the threshold of tissue ablation. In the canine experiments, a kidney lesion was achieved in 10 animals (63%) extracorporally. These lesions were also histologically determined to be coagulation necrosis. These lesions are created by highly focused ultrasound and are caused most likely by a combination of cavitation and thermal effects, depending on the duration and frequency of the ultrasound bursts. Exact mechanism of this effect is explored as well as potential clinical applications in treating kidney, liver, and prostate tumors in humans.


Flow-cytometric deoxyribonucleic acid analysis of the human bladder cancers with reference to histopathological findings. Flow-cytometric (FCM) DNA analysis was performed in 534 samples from 140 bladder tumor cases and was compared with histopathological findings. Frequency of DNA aneuploidy was closely correlated with tumor grade. Namely the incidences of DNA aneuploidy were 20% in grade 0 (papilloma), 25.6% in grade 1, 57.7% in grade 2 and 95.7% in grade 3. Invasive tumors showed a significantly higher incidence of DNA aneuploidy than superficial papillary tumors. Frequency of DNA aneuploidy of CIS was between them. Nonpapillary tumors showed a significantly higher incidence of DNA aneuploidy than papillary tumors. Tumors with vessel invasion did show a similarly higher incidence than those without. Approximately 10% of histologically normal mucosa taken from the bladder tumor patients showed DNA aneuploidy. The present study could support possibilities that FCM findings were highly correlated with tumor malignant potentials and were also able to predict precancerous lesions on histologically normal mucosa.


A new technique examines the connective tissue framework in normal testis and in testis cancer. A method of cellular digestion known as Etching facilitated scanning electron microscopy (SEM) of the connective tissue framework in normal testis and in cases of testis cancer. The collagen in the seminiferous tubules in normal testis has distinct lamellae and a well-defined outer border. In the germ cell tumours examined, the tubular connective tissue appeared hypertrophied, the distinct outer border was maintained in a seminoma specimen unlike in a case of non-seminoma. In a specimen of non-germ cell lymphoma there was gross distortion of the tubular connective tissue. These apparent variations in the collagen framework may have implications regarding local tumour development.


Percutaneous endoscopic urethrocervicopexy. A minimally invasive surgical technique is proposed which considerably simplifies the Stamey technique, shortens the surgical time and fives a weighted success rate of over 80%, which makes it worthy of consideration in treating female urinary incontinence.


Bellini duct carcinoma of the kidney.

Bellini duct carcinoma of the kidney. Human epithelial cells of the kidney present a wide spectrum of cytological and histological variation. The normal epithelium of the kidneys also includes a number of morphologically and functionally different cell types which are arranged along the nephrons and collecting ducts. Although renal carcinoma can involve any type of renal cell, the most common is renal cell carcinoma of the proximal tubuli. Here, we present the case of a 65-year-old Japanese patient with a renal cell carcinoma arising from Bellini duct epithelial cells. State-of-the-art techniques were used to establish the diagnosis and histogenesis of this renal cell carcinoma.


Orthotopic ileal bladder: clinical, urodynamic and metabolic evaluation. Since January 1985, orthotopic ileal bladder substitution after radical cystectomy was performed in 64 male patients. The Camey I procedure was performed in 35 patients (group 1) and the Studer procedure in 29 (group 2). Clinical, metabolic and urodynamic evaluation was performed at regular intervals with a mean follow-up of 27 months for group 1 and 13.6 months for group 2. Patients with a Camey I bladder reconstruction presented smaller capacity and higher intraluminal pressure resulting in shorter voiding intervals and a practically uniform presence of enuresis, as opposed to those reconstructed with the Studer procedure. The incidence of ureteral reflux was also higher in group 1. Metabolic studies in both groups revealed a slight metabolic acidosis which was treated with oral alkalinization. It is concluded that detubularization of the terminal ileum creates a more favorable low-pressure reservoir.


Surfactant protein A (SP-A) is decreased in acute parenchymal lung injury associated with polytrauma. To further investigate if the pulmonary surfactant system is altered in acute parenchymal lung injury of adults following polytrauma we measured SP-A level and phospholipid composition in 150 sequentially obtained lung lavage samples from poly-traumatized patients (n = 19) beginning at the day of trauma and ending 18 days later or when the patient was extubated. Out of the 19 patients studied 10 had severe parenchymal lung injury (ARDS), nine had moderate lung injury. SP-A was measured using a two-monoclonal sandwich ELISA-assay. Phospholipids were separated using high-performance liquid chromatography and their composition was calculated by comparison with standard phospholipid mixtures. We found immunoreactive SP-A concentrations ranging from 0.1 micrograms ml-1 to 8.5 micrograms ml-1 lung lavage fluid obtained from all patients. The mean SP-A concentration in patients who had severe parenchymal lung injury (ARDS) was 1.06 +/- 0.16 micrograms ml-1 lavage fluid, the mean concentration in patients who had only moderate parenchymal lung injury was 1.92 +/- 0.18 micrograms ml-1 lavage fluid. Both concentrations were lower than in healthy controls (2.74 +/- 0.3 micrograms ml-1 lavage fluid; n = 12). In patients who had moderate lung injury the SP-A level normalized, but in patients who had severe lung injury the SP-A level remained low during the timespan examined. SP-A alterations did not correlate to changes in phospholipid composition as determined in lung lavage samples of individual patients. We conclude that alveolar SP-A concentrations decrease in polytraumatized patients who have acute parenchymal lung injury soon after the trauma occurs.(ABSTRACT TRUNCATED AT 250 WORDS)


Plasma lipids affect maximum velocity not sodium affinity of human sodium-lithium countertransport: distinction from essential hypertension. Inheritance is a major determinant of increased sodium-lithium countertransport (SLC) activity in hypertension. However, hyperlipidaemia can also cause increased SLC activity in some individuals and it is difficult to distinguish this effect from the effect of hypertension. Erythrocyte SLC activity and its kinetic determinants sodium affinity (km) and maximum velocity (Vmax) were measured in 25 hyperlipidaemic patients and 15 normal controls (NC). Increased SLC activity (0.31 +/- SEM 0.03 mmol Li/(h x 1 cells) vs. NC 0.20 +/- 0.01, P < 0.01) in the hyperlipidaemic patients was associated with increased Vmax (0.59 +/- 0.07 vs. NC 0.41 +/- 0.03, P < 0.01) but normal km (median 120 range [40-324] mmol l-1 vs. 140 [108-260]. Lipid-lowering therapy resulted in decreased SLC activity secondary to a fall in Vmax. Km remained constant despite the changes in lipids and Vmax. The mechanism of increased SLC activity in hyperlipidaemia is different from that in essential hypertension where increased sodium affinity is found. Measurement of the kinetic characteristics of SLC may discriminate between the independent influences of hypertension and hyperlipidaemia on the sodium-lithium countertransporter.


The glucoregulatory and antilipolytic actions of insulin in abdominal obesity with normal or impaired glucose tolerance: an in vivo and in vitro study. To evaluate the effects of obesity and impaired glucose tolerance on insulin sensitivity, we performed a euglycaemic-hyperinsulinemic clamp at about 350 pmol l-1, combined with 3H-glucose infusion, in 14 obese patients, BMI 36.5 +/- 1.2 and in 12 matched controls, BMI 23.9 +/- 0.4. Six obese patients had normal glucose tolerance (oNGT), and eight had impaired glucose tolerance (oIGT). The ability of insulin to inhibit lipolysis in isolated adipocytes was also studied. Insulin-mediated glucose utilization was more severely impaired in oIGT than in oNGT with respect to the controls (621 +/- 51 vs. 897 +/- 83 vs. 1298 +/- 55 mumol m-2 min-1, P < 0.001). Plasma glycerol was higher in oIGT than in oNGT and in the controls, both fasting (238 +/- 12 vs. 179 +/- 14 vs. 112 +/- 8 mumol l-1, P < 0.001) and during the clamp (175 +/- 21 vs. 120 +/- 12 vs. 36 +/- 6 mumol l-1, P < 0.001). The correlation between glucose utilization and the percent reduction of plasma glycerol during the clamp was significant in the study group as a whole (r = 0.809, P = 0.0001), and in each of the groups separately (oIGT: r = 0.929, P = 0.002; oNGT: r = 0.943, P = 0.036; controls: r = 0.902, P = 0.0001). Inhibition by insulin of noradrenaline-stimulated lipolysis in isolated adipocytes was more severely impaired in oIGT than in oNGT compared with the controls (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)


Prolonged sleep-deprivation induced disturbed liver functions serum lipid levels, and hyperphosphatemia. Sixty-four healthy young male volunteers were kept awake from 76 to 80 h. Blood tests conducted at the start and conclusion of the continuous sleep deprivation revealed an increase of 170% in mean SGOT, 58.5% in mean SGPT and 37.5% in mean plasma phosphorus levels. Triglyceride levels decreased by 16%, while HDL levels increased by 18% and the apoB/apoA ratio decreased by 12%. Morning plasma cortisol showed a significant increase during the experiment while evening cortisol showed a significant decrease. Morning T3 levels increased from the first to second day and decreased on the third day. There were no significant changes in other plasma electrolyte levels.


Bile acid active and passive ileal transport in the rabbit: effect of luminal stirring. The intestinal absorption of bile acids (BA) with different chemical structure has been evaluated in the rabbit, after intestinal infusion of different concentrations (0.25-30 mM) of BA, by mesenteric blood sampling. Cholic (CA), chenodeoxycholic (CDCA), ursodeoxycholic (UDCA) acid, free and taurine (T-) conjugated, together with glycocholic (GCA) acid and deoxycholic acid (DCA) were studied. The apparent uptake parameters were calculated. All conjugated BA showed active transport (T max, nmol min-1 cm-1 int.), with Tmax values in the following order: TCA > TUDCA > TCDCA; unconjugated BA showed passive uptake, with values in the following order: DCA > CDCA > UDCA > CA. GCA and CA showed both passive uptake and active transport. For all BA studied the % uptake in the ileal segment considered was less than 10%, BA uptake being thus limited by transport and/or diffusion kinetics, rather than by flow velocity. The liquid resistance to BA radial diffusion inside the lumen was evaluated, and the infusate-to-blood uptake parameters corrected for it, in order to get the uptake parameters from the epithelium-to-liquid interface to mesenteric blood: the apparent Km decreased, passive uptake coefficient increased, while Tmax was unchanged. The passive component of the uptake, corrected for the luminal resistance, correlated with the BA hydrophobicity (r = 0.963; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)


Multi-frequency bioelectrical impedance augments the diagnosis and management of lymphoedema in post-mastectomy patients. The value of multiple frequency bioelectric impedence analysis (MFBIA) in the monitoring and management of post-mastectomy lymphoedema of the arm was evaluated in 15 patients and controls. The technique was found to produce quantitative agreement with a clinical diagnosis of lymphoedema and with the currently-used measure (limb volume calculated from circumferential measurements) of limb size. The significance of this finding lies in MFBIA being diagnostically informative: it indicates when an observed change in limb volume is directly, albeit theoretically, attributable to accumulation of extracellular fluid. MFBIA potentially offers the means for earlier definitive diagnosis and more-accurate monitoring of extracellular fluid changes during and after treatment.


Can urinary pyridinium crosslinks and urinary oestrogens predict bone mass and rate of bone loss after the menopause? We measured urinary pyridinoline and deoxy-pyridinoline by high performance liquid chromatography, and urinary oestrogens by radioimmunoassay, in 68 healthy postmenopausal women to evaluate these assays for the prediction soon after the menopause of the risk of developing osteoporotic fractures in later life. Change in forearm bone mineral content was assessed by single photon absorptiometry over 4 years. Although there was no significant correlation between the pyridinium crosslinks and urinary oestrogens, we found that up to 58% of the variation in the rate of loss of bone mineral content in women soon after the menopause could be explained by pyridinoline and oestradiol glucuronide assays together with body mass index. Measurement of the urinary pyridinium crosslinks and oestradiol glucuronide may make a significant contribution to a biochemical screening procedure for future osteoporotic fracture.


Autoantibodies to insulin have similar affinity to that of antibodies to exogenous insulin but lower binding capacity. The binding characteristics of insulin autoantibodies (IAA) were compared with those of antibodies to exogenous insulin (IBA) by analyzing the specific binding, binding capacity and affinity for insulin in 11 children (age range 1.5-13.0 years) with insulin-dependent diabetes (IDDM) both at diagnosis and after 1 year of insulin treatment. Maximal specific insulin binding was 7.8 (1.5; SE) pmol l-1 for IAA and 28.1 (6.7) pmol l-1 for IBA (P < 0.01), and the binding capacity of the high affinity class of IAA 0.01 (0.003) nmol l-1, as compared with 0.19 (0.08) nmol l-1 for the corresponding IBA class (P < 0.01). With regard to the low-affinity components the binding capacity was 0.11 (0.05) nmol l-1 for IAA and 1.50 (0.95) nmol l-1 for IBA (P < 0.01). No differences in the affinity constants could be observed between IAA and IBA. There was no correlation between the insulin binding of IAA and quantitative levels of islet cell antibodies (ICA) at the clinical presentation or subsequent IBA values. The specific insulin binding of IBA correlated negatively with serum C-peptide concentrations and positively with HbA1 levels at 1 year. The present observations suggest that IAA developing before the diagnosis of IDDM are characterized by a reduced binding capacity as compared with antibodies to exogenous insulin, whereas they have a similar affinity for insulin. IAA seem to be quantitatively unrelated to ICA and postdiagnostic IBA levels. High IBA levels appear to be associated with reduced endogenous insulin secretion and poor metabolic control during the early clinical course of the disease.


Effect of intravenous polyunsaturated phosphatidylcholine infusion on insulin receptor processing and lipid composition of erythrocytes in patients with liver cirrhosis. The aim of this study was to determine whether insulin receptor processing capabilities of human erythrocytes could be improved by changing the cell membrane lipid composition using an intravenous infusion of polyunsaturated phosphatidylcholine. Thirteen cirrhotics were submitted to the i.v. infusion of phosphatidylcholine (2 g day-1 for 3 days). Both erythrocyte lipid composition and insulin receptor processing ability were examined at the beginning of the study and at 0, 3 and 11 days after the end of the treatment. This treatment decreased the erythrocyte cholesterol to phospholipid molar ratio and increased the proportion of polyunsaturated fatty acids (mainly linoleic acid) immediately after the end of the treatment. The proportion of arachidonic acid increased immediately in the phosphatidylserine class and, a few days later, also in phosphatidylethanolamine. The phospholipid class distribution did not show any relevant modification in the course of the study. Surface insulin receptors, which generally were up-regulated in the untreated subject (-7.1 +/- 20.4%), showed an improvement in down regulation capabilities that appeared to be well correlated with the changes in lipid composition of cell membranes induced by i.v. infusion of polyunsaturated phosphatidylcholine. The confirmation of these findings also in target cells for insulin may open new perspectives in the treatment of diabetes mellitus.


Anti-neutrophil cytoplasm antibodies, anti-GBM antibodies and anti-dsDNA antibodies in glomerulonephritis. The diagnostic potential of assays detecting anti-neutrophil cytoplasm antibodies (ANCA), anti-GBM antibodies and anti-dsDNA antibodies was evaluated by examining sera from time of admission in a consecutive series of 455 patients with biopsy verified primary or secondary glomerulonephritis (GN). ANCA were classified into c- and p-ANCA by indirect immunofluorescence (IIF) and ELISAs using alfa-granule extract, proteinase-3, myeloperoxidase (MPO), elastase and lactoferrin. C-ANCA was virtually confined to 64 patients with systemic small vessel vasculitis, 66-74% being c-ANCA positive. P-ANCA against MPO, seen in 47 patients, segregated through many diagnostic categories of primary and secondary severe GN. ANCA against lactoferrin and elastase were rare. Anti-dsDNA positive patients constituted 57% of the 44 ANA-positive patients with systemic lupus erythematosus. It is concluded that the IIF and ELISAs for anti-proteinase-3, anti-MPO, anti-dsDNA and anti-GBM have an acceptable performance and are useful in the primary diagnostic work-up of patients suspected for secondary GN as the majority of such patients will be classified by these assays.


Effects of the new somatostatin analogue (BIM 23014) on blood glucose homeostasis in normal men. Changes in blood glucose homeostasis induced by the new somatostatin analogue BIM 23014 (BIM) were studied. Eight normal men (study 1) received either vehicle or 1000, 2000 and 3000 micrograms BIM as a 24 h s.c. infusion. Blood glucose, plasma insulin, C-peptide, glucagon and growth hormone (GH) were measured before treatment and then hourly for 24 h. In five normal men (study 2) an oral glucose tolerance test (OGTT) was performed during vehicle infusion and then on days 1 and 7 of a continuous s.c. infusion of 2000 micrograms BIM daily for 7 days. The same biological parameters as in study 1 were measured before OGTT and then twice-hourly for 5 h. Dose-dependent and transient glucose intolerance was observed in the first half of study 1. Except for glucagon, BIM significantly (P < 0.01) reduced plasma insulin, C-peptide and GH levels. In study 2 BIM infusion induced glucose intolerance and a drop in plasma insulin and C-peptide on day 1 which disappeared on day 7 of infusion. Higher on day 7 than on day 1, plasma GH secretion was significantly (P < 0.01) reduced throughout BIM infusion. In contrast plasma glucagon levels were not modified at any time. Side-effects were abdominal cramps and diarrhoea which were observed in most subjects when increasing BIM daily dose. In conclusion, BIM infusion induced transient changes in glucose homeostasis and insulin secretion in normal men. By contrast, plasma GH levels remained reduced throughout the treatment. BIM appears to be a useful tool to selectively inhibit GH secretion.


Extra-hepatic cholestasis determines a reversible increase of glycoproteic tumour markers in benign and malignant diseases. This study was performed in order to assess the relative role of cholestasis in increasing some serum glycoproteic markers of malignancy (CA 19-9, TPA, CEA). 30 Patients with benign and 16 with malignant extra-hepatic cholestasis were studied on admission (stage A) and after the operative or spontaneous resolution of the cholestatic picture (stage B). CA 19-9 and TPA were found to be lower in stage B than in stage A benign diseases. A similar behaviour was found in malignant diseases, although findings were significant only for CA 19-9. In neither of the patient groups was CEA found to present a significant trend. Extra-hepatic cholestasis appears able to increase per se serum glycoproteic markers in benign diseases, with variations proportional to the severity of the clinical picture. The same considerations can apply to malignancies, even if in these situations the production of tumour markers by the neoplastic growth should also be considered. We should therefore be cautious in assessing the diagnostic usefulness of new tumour markers when cholestasis is present.


Compositional analysis of the collagenous bone matrix. A study on adult normal and osteopenic bone tissue. The collagenous constituents of mature bone of 30 individuals 22-93 years of age were studied by post-mortem morphological and biochemical analysis. Morphometric evaluation of the second lumbar vertebral body revealed striking interindividual differences in bone mass, mean trabecular density and mean trabecular thickness. Collagen extracted from vertebral trabecular bone by limited pepsin digestion consisted mainly of collagen I (92%) and collagen V (8%). Immunohistochemistry revealed a distinct distribution of these two collagen types within the bone matrix. The degree of lysyl hydroxylation of the alpha 2(I) collagen chain correlated inversely with the trabecular bone volume (TBV) and with the mean trabecular plate density. This correlation was statistically significant for the entire study group as well as for the female and male subgroups. Within the female subgroup, the lysyl hydroxylation/TBV ratio was higher in postmenopausal than in premenopausal women and was highest in women with established osteoporosis. No significant correlation was found between the level of lysyl hydroxylation and the age of the patients. The alpha 1(I) collagen chain showed a nearly constant degree of lysyl hydroxylation in all 30 samples. The results provide convincing evidence that morphometric changes associated with osteopenia in adult bone are accompanied by an altered level of lysyl hydroxylation of the alpha 2(I)-chain of collagen I. The biochemical alterations observed may be responsible for the deposition of a deficient bone matrix in osteopenic conditions.


Post-prandial lipoprotein metabolism in nephrotic syndrome. Post-prandial lipaemia was investigated in a group of nine subjects with nephrotic syndrome by following the concentrations of triglyceride and retinyl palmitate in the d < 1.006 g ml-1 fraction of plasma after a standard oral fat load containing vitamin A. Lipoprotein lipase and hepatic triglyceride lipase activities were measured in post-heparin plasma. Subjects with other renal disease but insignificant proteinuria acted as controls. The time course of the lipaemic response was similar in both groups although individual patients demonstrated a prolonged lipaemia. Overall, there were no significant differences in the rise in triglyceride at 6 h (nephrotic--median 2.53 mmol l-1; range 0.87-4.76 vs. control 1.88; 0.38-4.12, P = 0.34), the peak concentration of retinyl palmitate (nephrotic 0.87 mg dl-1; 0.27-2.16 vs. control 0.65; 0.24-1.89, P = 0.97) or the areas under the curve from 0-24 h for triglyceride (nephrotic 10.5 mmol. h l-1; 2.9-43.6 vs. control 9.7; 4.3-27.0, P = 1.0) or retinyl palmitate (5.5 mg.h dl-1; 1.0-23.4 vs. 4.3; 1.5-12.4, P = 0.7). At baseline, the particles in the d < 1.006 g ml-1 fraction of plasma from nephrotic subjects had a higher free cholesterol:phospholipid ratio but this difference was no longer apparent 6 h after the test meal. There were no differences in total heparin-releasable lipase, lipoprotein lipase or hepatic triglyceride lipase activities between the two groups. These data suggest that impaired clearance of chylomicrons is not a major contributor to nephrotic hyperlipidaemia in man.


Short-term indomethacin administration does not impair excretion of acute potassium load in humans. Maintenance treatment with prostaglandin synthesis inhibitors often causes some degree of hyperkalemia, indicating impaired potassium (K) excretion. Hypoaldosteronism probably is a mediating factor, but it is unknown whether these drugs also impair renal K excretion directly. Indomethacin, for example, stimulates NaCl reabsorption in Henle's loop, and thus may impair K excretion by decreasing distal NaCl delivery. We therefore studied the effect of 1 day administration of indomethacin (50 mg tid) on the excretion of a single oral KCl (1 mmol kg-1 body weight) in six healthy volunteers taking a 40 mmol sodium diet. To allow analysis of renal sodium handling, clearance studies were performed during water loading. In this acute setting, indomethacin had no effect on plasma K, and did not decrease plasma aldosterone. However, indomethacin clearly reduced NaCl excretion. Nonetheless, the excretion of the K load was entirely normal. Excretion of the K load was accompanied by increased clearance of phosphate and uric acid, and natriuresis. Data derived from the maximal free water clearance were compatible with increased delivery to and decreased reabsorption from the diluting segment. Occurrence of these effects was not prevented by indomethacin, although overall NaCl excretion remained less than observed without indomethacin. Indomethacin reduced prostaglandin E2 excretion substantially. Apparently, in normal man indomethacin does not impair K excretion directly, even though it greatly reduces NaCl excretion. Moreover, the effects of K on renal NaCl handling, probably contributing to the excretion of a K load, are not dependent on renal prostaglandins.


Visualization of extrastriatal dopamine D2 receptors in the human brain. [123I]Epidepride, a potent and selective dopamine D2 radioligand, was administered to a 27 year old normal male volunteer. Single photon tomography revealed that peak striatal uptake occurred at 4 h after injection with a striatal:cerebellar ratio of 7.8 rising to over 100 at 18 h post injection. Uptake above the levels seen in cerebellum was also noted in the thalamus, pituitary, hypothalamus and temporal lobe, particularly medially. Single photon tomography with [123I]epidepride allows visualization of extrastriatal dopamine D2 receptors in man.


N-ethyl-carboxamide adenosine inhibits perioral dyskinesias induced by sulpiride + SKF 38393 in rabbits. A pattern of perioral dyskinesia was induced in adult male rabbits by concomitant stimulation of dopamine D1 receptors (SKF 38393) and blockade of dopamine D2 receptors (sulpiride). Rabbits treated with sulpiride (6 and 12.5 mg/kg i.v.) then, 90 min thereafter, with SKF 38393 (0.1, 1 and 10 mg/kg i.v.) showed a pattern of perioral dyskinesia characterized by compulsive and repetitive sniffing, licking and vacuous chewing. These effects were completely prevented by the administration of N-ethylcarboxamide adenosine (NECA), an A2 > A1 adenosine receptor agonist. The present results confirm that perioral dyskinesia is dependent on the activation of dopamine D1 receptors. They also show that, in order to induce perioral dyskinesia in rabbits, a concomitant blockade of dopamine D2 receptors is required. Finally, the antagonistic effect of NECA on the appearance of perioral movements confirms that adenosine receptors play a key role in the control of dopamine-mediated effects.


Modification of muscarinic acetylcholine receptors in the rat brain following chronic immobilization stress: an autoradiographic study. The modifications of rat brain muscarinic acetylcholine receptors induced by chronic immobilization stress lasting 10 min/daily or 2 h/daily for 3, 7 or 21 days were analyzed by quantitative in vitro autoradiography. [3H]N-Methylscopolamine ([3H]NMS) was used as ligand. Chronic immobilization stress for 10 min/day did not produce any significant change in the properties of [3H]NMS binding sites throughout the rat brain. In contrast, 2 h/day immobilization caused a significant increase in the maximal number of muscarinic receptors (Bmax) in several brain areas such as the cortical layers, the CA1 field of the hippocampus and caudate-putamen, among others. Affinity values (Kd) were not modified. These results suggest that chronic immobilization stress induces supersensitivity of muscarinic receptors in certain cholinergic pathways in rat brain, the pattern of response being different to that previously found for acute stress.


Pharmacological distinction of the hyperpolarization response to caffeine and acetylcholine in guinea-pig coronary endothelial cells. Membrane potential changes in endothelial cells in response to caffeine and acetylcholine (ACh) were recorded with microelectrodes from an intact endothelium preparation from the guinea-pig coronary artery. Caffeine induced a transient hyperpolarization of the membrane in a concentration-dependent manner. The hyperpolarization was inhibited by removal of Ca2+ from the bathing medium and by ryanodine (20 microM). It was not affected by 3,4,5-trimethoxybenzoic acid 8-(diethylamino) octyl ester hydrochloride (TMB-8, 10 microM) or neomycin (5 mM). ACh induced a sustained hyperpolarization in endothelial cells. At concentrations that caused no significant effects on the caffeine response, TMB-8 and neomycin inhibited hyperpolarization induced by ACh. Ryanodine did not inhibit the response to ACh. The ACh-induced hyperpolarization was also inhibited by caffeine in a concentration-dependent manner. Results from the present study suggest that hyperpolarizations induced by caffeine and ACh are mediated by separate Ca2+ pools.


Thyrotropin-releasing hormone analog injected into the raphe pallidus and obscurus increases gastric contractility in rats. The present study was performed to investigate the influence of the chemical stimulation of medullary raphe nuclei by the stable TRH (thyrotropin-releasing hormone) analog, RX 77368, on gastric contractility. Urethane-anesthetized rats were acutely implanted with miniature strain gauge force transducers on the corpus of the stomach for continuous recording of gastric contractility. Traces were analyzed by computer. Microinjections of vehicle or RX 77368 into the raphe pallidus or raphe obscurus were performed using pressure injection of 50 nl through glass micropipettes 30 min following basal recording of gastric contractility. RX 77368 (0.7-77 pmol) dose dependently stimulated gastric contractility when microinjected into the raphe pallidus and raphe obscurus. The stimulation of gastric contractions induced by microinjection of RX 77368 (77 pmol) into these raphe nuclei was completely blocked by vagotomy and prevented (raphe obscurus) or reduced (raphe pallidus) by atropine. RX 77368 (7.7-77 pmol) microinjected into the inferior olive, pyramidal tract, medial lemiscus was ineffective. These results demonstrate that chemical stimulation of the raphe pallidus and obscurus by RX 77368 stimulates gastric contractility through vagal and muscarinic pathways. These data suggest a role for medullary raphe nuclei in the central vagal regulation of gastric contractility.


Repeated systemic administration of the mixed inhibitor of enkephalin-degrading enzymes, RB101, does not induce either antinociceptive tolerance or cross-tolerance with morphine. The potent analgesic responses elicited by systemic administration of RB101, N-[(R,S)-2-benzyl-3[(S)(2-amino-4-methylthio)butyldithio]-1-oxopro pyl]- 1-oxopropyl]-L-phenylalanine benzyl ester, a prodrug able to inhibit enkephalin-degrading enzymes completely after in vivo bioactivation, has made it possible to investigate the development of antinociceptive tolerance after chronic potentiation of endogenous enkephalins. The ED50 values of RB101 obtained 10 min after i.v. injection were not significantly different in mice treated for 4 days with i.p. administered vehicle (ED50 = 9.50 (6.37-14.15) mg/kg), or with 80 mg/kg of RB101 twice daily (ED50 = 9.50 (5.86-15.39) mg/kg). In contrast, a parallel rightwards shift of the dose-response curves, corresponding to a significant 1.92 (1.49-2.52)-fold decrease in analgesic potency, was observed after i.v. administration of morphine in mice chronically treated with morphine (3 mg/kg, twice daily for 4 days) (ED50 = 3.10 (2.52-3.81) mg/kg) vs. saline (ED50 = 1.60 (1.22-2.09) mg/kg). No tolerance to RB101 was observed even after a longer period (8 days) of chronic treatment with the prodrug. Moreover, no cross-tolerance between morphine and RB101 appeared to occur since the ED50 values obtained after i.v. administration of RB101 were not significantly different in mice chronically pretreated with vehicle (ED50 = 9.50 (6.37-14.15) mg/kg) or with morphine (ED50 = 10.00 (6.62-15.10) mg/kg). The analgesic effect of RB101 observed in morphine-tolerant mice was antagonized by prior injection of naloxone, but not naltrindole (delta-selective antagonist), supporting a preferential involvement of mu-opioid receptors in the antinociceptive effect of RB101, at least in mice in the hot-plate test.(ABSTRACT TRUNCATED AT 250 WORDS)


Lack of physical dependence in mice after repeated systemic administration of the mixed inhibitor prodrug of enkephalin-degrading enzymes, RB101. Development of physical dependence is observed after treatment with opioid agonists, but not after chronic i.c.v. administration of mixed inhibitors of enkephalin-degrading enzymes. The aim of this study was to investigate further this promising result of repeated administration of the systemically active mixed inhibitor prodrug RB101, N-[(R,S)-2-benzyl-3[(S)(2-amino-4-methylthio)butyldithio]-1-oxopro pyl]- L-phenylalanine benzyl ester. In a comparative study, the naloxone-evoked withdrawal syndrome was quantified in mice chronically treated with i.p. administered morphine or RB101 (6 and 160 mg/kg, respectively) for 5 days, twice daily. After administration of naloxone (5 mg/kg s.c.) on the sixth day, large behavioral changes (jumps, paw shakes, wet-dog shakes, tremor, teeth chattering) and body weight losses occurred in the morphine-treated mice. In contrast, no significant behavioral signs of physical dependence, or body weight changes were observed in the RB101-treated mice. The difference between morphine and RB101 could be partially due to a very low tonic release of enkephalins in the locus coeruleus, a brain region critically involved in the development of physical dependence. These results confirm the potential of mixed inhibitors of enkephalin-degrading enzymes as new non-addictive analgesics.


Influence of age on responsiveness of rat gastric fundus to agonists and to stimulation of intrinsic nerves. The contractile effect of methacholine, prostaglandin F2 alpha (PGF2 alpha) and electrical stimulation of cholinergic neurones, and the relaxant effect of nitric oxide (NO), vasoactive intestinal polypeptide (VIP) and electrical stimulation of inhibitory non-adrenergic non-cholinergic (NANC) neurones were studied in longitudinal smooth muscle strips of the gastric fundus of young (3 months), adult (12 months) and old (24 months) male Wistar rats. The contractile responses to methacholine and to electrical stimulation of cholinergic neurones were not significantly different between the three age groups. The responses to PGF2 alpha were significantly more pronounced in young than in adult and old rats. The relaxant response to electrical stimulation of NANC neurones with a cumulative increase in frequency showed a decreased response in old rats at the higher stimulation frequencies. This was mimicked by a decreased response to VIP, suggesting that there is a decrease in muscular sensitivity to VIP rather than an impaired capacity to VIP release with increasing age. The relaxant response to electrical stimulation of NANC neurones with short trains was similar in the three age groups, while the sensitivity to exogenous NO increased with age. The latter might be a compensatory mechanism for a decrease in stimulation-induced NO release with age.


Effect of naftidrofuryl oxalate on 5-HT2 receptors in mouse brain: evaluation based on quantitative autoradiography and head-twitch response. The effects of naftidrofuryl oxalate (LS-121) on 5-HT2 receptors in the brain were assessed in mice on the basis of quantitative autoradiography and head-twitch responses. LS-121 inhibited [3H]ketanserin (2 nM) binding in all brain areas assayed in which there were 5-HT2 receptors, such as the frontal cortex, cingulate cortex, parietal cortex, occipital cortex, temporal cortex, nucleus accumbens, caudate-putamen, olfactory tubercle and hippocampus. In the frontal cortex, which has the highest density of 5-HT2 receptors, the Ki value of LS-121 was 6.08 x 10(-8) M. The inhibitory potencies of methysergide and ritanserin for 5-HT2 receptors were about 16- and 60-fold stronger, respectively, than that of LS-121. Moreover, in behavioral studies, LS-121 (12.5-50 mg/kg i.p.) produced dose-dependent and significant inhibitory effects on head twitches induced by 5-hydroxytryptophan (5-HTP) plus pargyline, which is a 5-HT2 receptor-dependent behavior in mice. These results suggest that LS-121 inhibits 5-HTP plus pargyline-induced head twitches by blocking 5-HT2 receptors.


Chronic naltrexone treatment of rats: effects on gastrointestinal opioid peptide content. The gastrointestinal tract contains immunoreactive enkephalins and beta-endorphin. The objective of the current study was to determine whether chronic treatment of rats with naltrexone altered the gastrointestinal tissue content of these opioid peptides. Opioid activity measured by radioreceptor assay was detectable throughout the gastrointestinal tract. There were regional differences in the [Met5]enkephalin: [Leu5]enkephalin-immunoreactivity (IR) ratios, possibly due to cell specific differential processing of precursor molecules or degradation of the peptides. Chronic naltrexone treatment increased opioid activity in the duodenum and jejunum, decreased [Met5]enkephalin-IR in the duodenum and [Leu5]enkephalin-IR in the gastric corpus, and increased beta-endorphin-IR in the duodenum. However, the changes were small, and it is unlikely that any functional changes resulting from naltrexone treatment can be reliably ascribed to such changes in tissue content.


Effects of glycine and structurally related amino acids on generation of long-term potentiation in rat hippocampal slices. The effects of glycine and structurally related amino acids, serine, alanine and valine, on generation of long-term potentiation (LTP) of evoked potentials were investigated in the CA1, CA3 and dentate regions of rat hippocampal slices. In the Schaffer collateral-CA1 pyramidal cell synapses and in the perforant path-dentate granule cell synapses, glycine (5 x 10(-4) M) significantly enhanced the short-term potentiation (STP) induced by subthreshold tetanic stimulation, without affecting baseline responses. The effects of glycine resulted in generation of LTP in both synapses. On the other hand, glycine did not influence STP induced by subthreshold tetanus in the mossy fiber-CA3 pyramidal cell synapses. These results suggest that exogenous glycine can facilitate the generation of LTP in the CA1 region and in the dentate gyrus but not in the CA3 region. In the CA1 region and the dentate gyrus, D- and L-serine and D-alanine (10(-3) M) also showed the LTP-facilitating effects in a similar manner to glycine, but D- and L-valine had no effect on LTP generation. Furthermore, glycine and D-serine, but not L-valine, enhanced NMDA receptor-mediated synaptic responses in the absence of extracellular Mg2+. Together, these results make it probable that exogenously applied glycine and related amino acids facilitate the generation of LTP in the CA1 and dentate region by activating the glycine modulatory sites associated with NMDA receptors.


Antiepileptic effects of CNK-602A, a novel thyrotropin-releasing hormone analog, on absence-like and tonic seizures of spontaneously epileptic rats. The effects of CNK-602A (N-[(6-methyl-5-oxo-3-thiomorpholinyl) carbonyl]-L-histidyl-L-prolinamide), a novel thyrotropin-releasing hormone related analog, were investigated on absence-like seizure and tonic convulsion in the spontaneously epileptic rat (SER), which is a genetically defined double-mutant. When CNK-602A of 0.2-1 mg/kg was given intravenously to the animal, there were no changes in the background EEG except for an increase in low-voltage fast waves concomitant with behavioral alertness. However, CNK-602A suppressed absence-like seizure and tonic convulsion in a dose-dependent manner for over 1 h. These antiepileptic effects of CNK-602A on both seizures were antagonized by pretreatment with haloperidol (1 mg/kg, i.p.). It was found, using a brain in vivo microdialysis method, that CNK-602A at a dose of 1 mg/kg, which inhibits the seizures, increased the release of dopamine in the caudate nucleus. These results suggest that CNK-602A inhibits the seizures of SER in a similar manner to thyrotropin-releasing hormone (TRH), probably by increasing the release of dopamine in the central nervous system. In addition, the antiepileptic effects of CNK-602A were more potent and lasted longer than those of TRH.


Central action of sigma receptor ligand, JO 1784, to suppress CRF-induced inhibition of gastric function in conscious rats. The central interaction between the sigma receptor ligand, JO 1784, and corticotropin-releasing factor (CRF)-induced inhibition of gastric acid secretion and emptying was investigated in conscious rats. Intracisternal (i.c.) injection of CRF (5 micrograms) inhibited by 95% gastric acid secretion. JO 1784 (0.05-0.5 micrograms) given i.c. immediately before i.c. injection of CRF partially reversed CRF antisecretory action whereas JO 1784 (5 micrograms) given i.v. had no effect. CRF (0.6 micrograms i.c.)-induced 83% inhibition of gastric emptying was reversed by 45% by JO 1784 (5 micrograms i.c.). JO 1784 (5-50 micrograms i.c.) did not influence basal gastric function. These data demonstrate a centrally mediated antagonistic action of the sigma receptor ligand, JO 1784, on i.c. CRF-induced inhibition of gastric function.


WAY 120,491 activates ATP-sensitive potassium channels in rat tail artery. WAY 120,491 lowers blood pressure in a number of animal models. Its mechanism of action appears to be the selective opening of K+ channels in vascular smooth muscle cells. The patch clamp technique was used to determine the specific K+ channel affected by WAY 120,491 in isolated tail artery cells of the rat. In the inside-out configuration, WAY 120,491 caused a dose dependent partial reversal of the ATP-induced inactivation of channel activity. Glyburide (10 microM) almost completely inhibited the effect of WAY 120,491. WAY 120,491 had no effect on Ca-activated K+ channels inactivated by the absence of Ca2+. In the whole cell configuration, 10 microM WAY 120,491 increased outward K+ current. 10 microM glyburide completely reversed the increase in current. WAY 120,491 appears to be a relatively specific activator of ATP-sensitive K+ channels in vascular smooth muscle.


Effect of extracellular calcium concentration on angiotensin AT1 receptor-mediated smooth muscle contraction and antagonism in rabbit aorta. Angiotensin-II (AII) stimulates smooth muscle contraction by activating angiotensin AT1 receptor which induces intracellular Ca2+ release and Ca2+ influx from extracellular space. In this study, effect of extracellular Ca2+ concentration ([Ca2+]0) on angiotensin AT1 receptor-mediated contractile response to AII has been examined in the absence and presence of [Sar1,Ala8]AII in rabbit aorta. A decrease in agonist potency and an increase in antagonist potency for depression were observed in low [Ca2+]0. Data were interpreted by applying an explanatory model developed previously. The result indicates that [Ca2+]0 is linked to the efficacy expression of AII at angiotensin AT1 receptor and this prompted speculation about the underlying mechanism.


Molecular orbital study on the glutathione-dependent detoxication of ozonides. The present paper describes a theoretical study on the mechanism underlying the reaction of cellular glutathione (GSH) with polyunsaturated fatty acid ozonides. The reaction can be catalyzed by glutathione S-transferases and leads to detoxication of the ozonides. Semi-empirical molecular orbital computer calculations suggest that the reaction of glutathione with ozonides involves a nucleophilic attack at one of the carbon atoms of the ozonide ring, instead of at one of the peroxidic oxygen atoms of the ozonide ring. This implies a mechanism different from that of the glutathione S-transferase-mediated reaction with hydroperoxides, previously proposed for the glutathione-dependent detoxication of fatty acid ozonides.


Activation and damage of cultured airway epithelial cells by human elastase and cathepsin G. Accumulation of polymorphonuclear neutrophils (PMN) and epithelium damage have often been described during airway inflammation. We studied the effects of two PMN-derived proteinases, namely elastase and cathepsin G, on guinea-pig tracheal epithelial cells in culture. Both proteinases activated tracheal epithelial cells in terms of prostaglandin (PG) E2 production. A concentration- and time-dependent effect was observed with 10 micrograms/ml and 6 h as the optimal conditions for both enzymes. Optical microscopic studies confirmed an effect on tracheal epithelial cells as intercellular gaps were observed upon incubation of the monolayers with proteinases. A small cytotoxic effect was observed after 1 h incubation but remained stable up to 6 h. This cytotoxic effect, more pronounced with elastase than with cathepsin G, was dissociated from PGE2 formation.


Depletion of ATP but not of GSH affects viability of rat hepatocytes. The purpose of this study was to examine the role of glutathione depletion and alterations in the energy status in the induction of acute cytotoxicity to freshly isolated rat hepatocytes. Depletion of intracellular glutathione by diethyl maleate and phorone to levels below 5% of control did not induce loss of viability nor loss of intracellular ATP. Ethacrynic acid, a compound known to deplete mitochondrial GSH in addition to cytosolic GSH, induced cell killing after a depletion of ATP, next to GSH depletion. The results confirmed that depletion of intracellular glutathione alone does not necessarily result in cell killing. Only when glutathione depletion is succeeded by reduction in ATP levels, loss of cell viability is observed. The relationship between alterations in the energy status and the induction of cell death was further substantiated by inhibition of glycolytic and mitochondrial ATP generation. Treatment of hepatocytes either with iodoacetic acid to inhibit glycolysis (in hepatocytes from fed rats) or with potassium cyanide to inhibit mitochondrial respiration (in hepatocytes from both fed and fasted rats) revealed that depletion of intracellular ATP could lead to lethal cell injury. The susceptibility of cells to metabolic inhibition was better reflected by the rate of reduction in the energy charge than by the reduction of ATP alone. In conclusion, our results suggest that alterations of the energy status may be a critical event in the induction of irreversible cell injury. Depletion of cellular GSH is only cytotoxic when followed by a reduction of the energy charge.


Selective cytotoxic activity of cyclosporins against tumor cells from patients with B cell chronic lymphocytic leukemia. A fluorometric microculture cytotoxicity assay was employed for the study of cyclosporin A induced cytotoxicity in tumor samples from patients with B type chronic lymphocytic leukemia (B-CLL). Tumor cells from patients with B-CLL were found to be significantly more sensitive to the cytotoxic actions of cyclosporin A than normal blood mononuclear cells and tumor cells obtained from patients with different types of acute leukemia and solid tumors. The effect of cyclosporin A on B-CLL samples could be reproduced by a non-immunosuppressive cyclosporin A analogue. One B-CLL patient treated with cyclosporin A responded with a significant decrease in tumor mass and alleviation of anemia and B symptoms. The results show that cyclosporin A and its non-immunosuppressive analogues appear selectively toxic to B-CLL cells, an observation which may have clinical implications.


Age of rats affects response of lens epithelial explants to fibroblast growth factor. Fibroblast growth factor (FGF) is a potent inducer of fibre differentiation in lens epithelial explants from neonatal rats. Previously, using explants prepared from the central region of the lens epithelium, we showed an age-related loss of ability to accumulate fibre-specific crystallins in response to basic FGF. These studies have now been extended to include the peripheral region of the lens epithelium. Firstly we cultured explants from the central or peripheral regions of neonatal lenses with varying doses of FGF for 5 days, then determined how much fibre-specific beta-crystallin they had accumulated. The concentration of FGF required to induce a half-maximal response was lower for peripheral than for central cells (7 ng ml-1 compared with 36 ng ml-1). We then compared the ability of peripheral explants from 3-, 21-, 100- and 175-day-old rats to undergo fibre differentiation during culture with FGF for 13 days. In these studies alpha-, beta- and gamma-crystallins were localized in explants or quantified by ELISAs. There was an age-related decrease in responsiveness to FGF, as already observed for central explants; however, unlike central explants, peripheral explants from the oldest rats still retained the ability to respond to FGF by accumulating beta-crystallin. This suggests that FGF in the eye may play an important role in inducing lens epithelial cells at the lens equator to differentiate into fibres throughout life.


The cDNA RPE1 and monoclonal antibody HMB-50 define gene products preferentially expressed in retinal pigment epithelium. As a first step towards identifying genes expressed specifically in the retinal pigment epithelium (RPE), we generated a bovine RPE cDNA library. In preliminary characterization of this library, we isolated a clone, RPE1, that was identified as the bovine homologue of a human cDNA thought to encode the HMB-50 melanoma antigen. Sequence analysis suggests RPE1 encodes a membrane-anchored glycoprotein. In Northern blot analysis of RNA from bovine tissues, the 2.5 kb RPE1 transcript was detected only in the RPE. Southern blot analysis suggested the presence of a single bovine rpe1 gene. In normal human eyes, HMB-50 immunoreactivity was also restricted to the RPE; no immunoreactivity was detected in other intraocular pigmented cells. Thus, RPE1 and HMB-50 define gene products preferentially expressed in the RPE at the RNA and protein levels, respectively.


Preparation of fluorescent basic fibroblast growth factor: localization in living retinal microvascular endothelial cells. A biologically active fluorescent derivative of recombinant human basic fibroblast growth factor (bFGF) was prepared by immobilization on heparin-Sepharose 4B (HS) and derivatization with the fluorophore, Texas Red (TR). TR-bFGF was separated from free dye and carrier protein by elution from HS using 1.5 M NaCl. TR-bFGF contained an average of two dye molecules bound per bFGF, retained its mitogenic activity and was visible using a fluorescence microscope equipped with silicon intensified target camera (SIT). TR-bFGF stimulated the growth of bovine aortic endothelial cells (BAEC), microvessel endothelial cells (MVEC) and BHK-21 cells grown in culture. BAEC, MVEC and BHK-21 cells treated with 20 ng ml-1 (1 nM) TR-bFGF for 72 hr were stimulated over serum controls by 87, 26 and 6%, respectively. TR-bFGF stimulated EC growth was inhibited in a dose-dependent fashion when cells were coincubated with microM chloroquine. When EC were treated with TR-bFGF at 4 degrees C and then monitored at 37 degrees C, bright, focal, cytoplasmic spots were observed, which accumulated as punctate, perinuclear fluorescence. EC internalization of TR-bFGF was inhibited 80% by the addition of 100-fold molar excess unlabeled bFGF or by maintaining cultures at 4 degrees C. TR-bFGF colocalized with an EC lysosomal marker, but TR-bFGF was not detected in the nucleus. Results of these localization studies suggest that TR-bFGF stimulates EC proliferation without entering the nucleus.


Biochemical changes and cataract formation in lenses from rats receiving multiple, low doses of sodium selenite. Nuclear cataract formed in rat lens in response to a protocol of multiple, low doses of sodium selenite. Nuclear cataract occurred, in both Wistar and Sprague-Dawley rats, following five subcutaneous injections of selenite over an 8-day period with an accumulated dose of 40-50 nmol selenite g-1 body weight. Glutathione content decreased within the first 24 hr of treatment and remained at 60% of controls. Lipid peroxidation occurred in Wistar rats prior to nuclear cataract formation. A two to three-fold increase in calcium concentration and decreased protein content accompanied nuclear cataract development. Enzyme activities were measured for glutathione peroxidase, glutathione reductase, and glutathione S-transferase, and only the peroxidase activity remained constant through the period of cataract formation. This protocol resulted in nuclear cataracts similar in appearance to those observed with a single, acute dose of selenite. The opportunity to control the rate of selenite-dependent cataract formation allows further definition of precataractous events.


Rhodopsin regeneration in the normal and in the detached/replaced retina of the skate. The bleaching and regeneration of rhodopsin in the skate retina was studied by means of fundus reflectometry, both in the normal eyecup preparation and after the retina had been detached and then replaced on the surface of the pigment epithelium (RPE). After bleaching virtually all the rhodopsin in the retinal test area of the normal eyecup, more than 90% of the photopigment was reformed after about 2 hr in darkness; over most of this time course, rhodopsin density rose linearly at a rate of 0.875% min-1 with a half-time of 55 min. Detaching the retina from its pigment epithelium resulted in a number of abnormalities, both structural and functional. Histological examination of the detached/replaced (D/R) retina showed striking alterations in the structural integrity of the RPE cells at their interface with the neural retina. The cells appeared vacuolated and misshapen, and the apical processes of the RPE, which normally ensheath the receptor outer segments, were shredded and free of their association with the visual cells. These morphological changes, as well as dilution of the IRBP content of the subretinal space caused by separation of the tissues, appear to be the main factors contributing to the functional abnormalities in rhodopsin kinetics. But despite these abnormalities and the persistent detachment, the rate of regeneration and the amount of rhodopsin reformed after bleaching were reduced by less than 50% of their normal values. The fact that a significant fraction of the bleached rhodopsin was regenerated under these conditions indicates that 11-cis retinal formed in the RPE was able to traverse a much greater than normal subretinal space to reach the opsin-bearing photoreceptor membranes.


Age-related changes of sulfated proteoglycans in the normal human trabecular meshwork. Ultrastructural changes in sulfated proteoglycans were studied in 12 pairs of normal eye-bank eyes (aged 1 day to 92 years), using the cationic dye, cuprolinic blue, in a 'critical electrolyte concentration'. Pretreatment of trabecular meshwork sections with various glycosaminoglycanases and nitrous acid served to characterize these proteoglycans. Three sizes of proteoglycan-cuprolinic blue (PG-CB) complexes were found in association with different extracellular matrix components. Small, thin PG-CB complexes were closely associated with collagen fibrils. Large, thick PG-CB complexes, although located close to collagen fibrils in a variety of places, were most commonly seen between the boundaries of the collagen bundles, where they were associated with fine filaments. Both types of collagen-associated PG-CB complexes contained chondroitin sulfate and dermatan sulfate, with dermatan sulfate predominant. Basal lamina-associated PG-CB complexes contained heparan sulfate. An age-related, progressive coalescence of collagen was found in normal trabecular meshwork in a statistically significant fashion; the regions of collagen coalescence were associated with a decrease of small, collagen-associated PG-CB complexes and an increase of a previously unrecognized matrix material. The measurement of areas of coalescence of collagen was used as an indirect indicator of small, collagen-associated PG-CB complex loss with age. Large collagen-associated PG-CB complexes and basal lamina-associated PG-CB complexes decreased from infant to young adult; no additional loss with age was found. Further studies will be needed to determine whether loss of sulfated PGs plays a role in increased aqueous outflow resistance that characterizes glaucoma.


Isolation of a cDNA encoding a glutathione S-transferase (GST) class-pi from the bovine ocular ciliary epithelium. We have used a polyclonal antiserum to bovine ciliary epithelium, a secretory tissue involved in the formation of aqueous humor, to immunoscreen a directional lambda gt11 Sfi-Not cDNA expression library prepared from bovine ciliary epithelium poly(A)+ RNA. After immunoscreening 6 x 10(5) independent clones, 41 cDNA clones positive for ciliary epithelium were isolated and characterized. About one-third of the positive cDNA clones were found to be identical and to encode a glutathione S-transferase (GST) class-pi. The largest bovine GST cDNA clone isolated, pCN11, contains an open reading frame of 630 bases, encoding a protein of 210 amino acids with a calculated molecular weight of 23,335 Da. The corresponding amino acid sequence showed an overall identity of 85.6% with the human, and 85.2% with the rat and mouse GST class-pi. Northern analysis of bovine ocular tissues revealed that the GST class-pi gene encodes a 0.8-kilobase mRNA which is expressed most abundantly in cornea, ciliary epithelium and retina, and in lower levels in iris and lens. Cell lines derived from non-pigmented or pigmented bovine ciliary epithelium also showed high levels of GST-pi mRNA expression. These results provide additional evidence for differential gene expression of GST class-pi mRNA in various areas of the bovine eye.


Light stimulates in vivo inositol lipid turnover in frog retinal pigment epithelial cells at the onset of shedding and phagocytosis of photoreceptor membranes. We have developed an experimental model to study in vivo inositol lipid metabolism in frog retinal pigment epithelial (RPE) cells, including the effect of light on phospholipase C-mediated hydrolysis of phosphatidylinositol 4,5-bisphosphate. RPE cells were rapidly isolated after either brief light or dark periods. Light and electron microscopy showed complete detachment of the retina from the RPE cells, and that the RPE cell suspensions were devoid of photoreceptor cell outer segments. Frog tissues were labeled in vivo for 20 hr by intravitreal injection of [3H]inositol (4 microCi, 4 microliters per eye) within a 24-hr constant illumination period. Following 1 hr of darkness (priming period), frogs were intravitreally injected with LiCl (0.5 M, 4 microliters per eye) 15 min before the onset of either 30-min light stimulation or an additional 30 min of darkness (controls). In order to preserve endogenous inositol phosphate pools present after dark and light exposure, the RPE cells were harvested in the shortest time possible, at low temperatures (18-20 degrees C), and in the presence of 10 mM LiCl. Total [3H]inositol-labeled water-soluble products (inositol plus inositol phosphates) were increased by 86% after 30 min of light. Inositol trisphosphate (IP3) showed the highest accumulation (a 5.5-fold increase), followed by inositol bisphosphate (1.9-fold increase) and inositol monophosphate (1.4-fold increase). Free [3H]inositol also accumulated (2.8-fold increase), reflecting only a partial inhibition of phosphomonoesterase by LiCl. These changes were paralleled by a 12% decrease in 3H-labeled phosphatidylinositol with no significant difference in the labeling of polyphosphoinositides.(ABSTRACT TRUNCATED AT 250 WORDS)


Coexpression of FGF-5 and bFGF by the retinal pigment epithelium in vitro. Members of the fibroblast growth factor (FGF) gene family have been proposed to play critical roles in the biology of the outer retina. In this study, in vitro cultures of human retinal pigment epithelial (RPE) cells were surveyed for the expression of FGF gene family members. Northern analysis provided evidence for the expression of the previously reported 7.0 and 3.7 kb basic FGF (bFGF) transcripts and for the 4.0 and 2.1 kb FGF-5 transcripts. Western analysis demonstrated the presence of three bFGF proteins ranging in size from 18 to 26 kDa and three FGF-5 proteins of molecular weights 28.5, 34, and 36 kDa. We were particularly interested in cellular mechanisms which might regulate the steady-state mRNA levels of these genes. It was determined that bFGF message levels decreased with increasing culture density, increased upon serum stimulation and when placed in contact with matrix components found in the extracellular matrix of RPE cells in vivo. In a similar fashion, the steady state mRNA levels for FGF-5 decreased with increasing culture density, increased upon serum stimulation, but appeared to be unaffected by matrix contact.


Shortening of the calycal process actin cytoskeleton is correlated with myoid elongation in teleost rods. Light activates the elongation of rods within teleost retinas. Rod cell elongation is mediated by actin-dependent length changes of the myoid portion of the inner segment. The actin cytoskeleton of the inner segment consists of filament bundles, which run parallel to the long axis of the rod, from the calycal processes, through the ellipsoid and into the myoid. In isolated rod inner/outer segments (RIS-ROS), myoid elongation was found to occur in the absence of net polymerization of actin into filaments. Outgrowth of actin filaments within the myoid was counterbalanced by a shortening of actin filaments within the calycal processes. In this study, we have further examined light-activated modifications of the rod cytoskeleton using rhodamine-phalloidin to stain actin filaments within retinal cryosections as well as in isolated RIS-ROS. In RIS-ROS isolated from dark-adapted green sunfish, the phalloidin-stained calycal processes appeared as long, brush-like structures, averaging 4.2 microns in length. In light-cultured RIS-ROS populations, the calycal process actin cytoskeleton shortened from 4.2 microns to 1.7 microns. In control, dark-cultured populations, RIS-ROS that did not elongate maintained long calycal process actin cytoskeletons. However, in cases where dark-cultured RIS-ROS did elongate, despite the absence of a light stimulus, myoid elongation was accompanied by a shortening of the calycal process actin cytoskeleton, suggesting that the two events are correlated with one another. In light-adapted green sunfish and in light-cultured retinas from green sunfish and the Midas cichlid, the calycal process cytoskeleton of intact rods shortened by 40-60%. Within the two-tiered retina of green sunfish, shortening of the calycal process cytoskeleton, from 5.1 microns to 2.1-3.1 microns, was only evident in the shorter, inner tier of rods. The calycal process actin cytoskeleton did not appear to shorten within the longer, outer tier of rods; here, stained processes were short, averaging 2.3 microns in length, within dark-adapted retinas. Using scanning and transmission electron microscopy, we present evidence to suggest that the plasmalemmal surface of the calycal processes shortens along with the cytoskeletal actin core. We conclude that calycal processes of teleost rods are dynamic structures which shorten during light-activated myoid elongation.


Relaxation effects of diltiazem, verapamil, and tolazoline on isolated cat ophthalmociliary artery. This study investigates the ability of an alpha 1-adrenergic blocker, tolazoline, two Ca2+ entry channel blockers, verapamil and diltiazem, acetylcholine and Ca(2+)-free solutions to relax alpha 1-adrenergically activated cat ophthalmociliary artery ring segments. The form of a contraction elicited with adrenaline, noradrenaline or phenylephrine was shown to depend on the passive tension set. As passive tension was increased, which is equivalent to increasing blood pressure in vivo, the alpha 1-adrenergic elicited contraction became more sustained. Incubation with the Ca2+ channel blockers diltiazem and verapamil was ineffective in reducing the phasic response to the alpha 1-adrenergic agonists whereas addition of these blockers in increasing concentrations during a sustained adrenergic contraction caused a graded and significant relaxation. This implies that therapeutic use of Ca2+ channel blockers may act directly on the ophthalmociliary artery to inhibit the autonomic control of sustained tone in this vessel. Removal of exogenous Ca2+ from the bathing medium initially reduced the phasic component and eliminated the tonic component of the alpha 1-adrenergic contraction. Repeated exposure of the ring segment to Ca(2+)-free medium further reduced the phasic component elicited with alpha 1-adrenergic contraction. Pre-incubation with the alpha 1-adrenergic blocker Tolazoline reduced the alpha 1-adrenergic antagonist phasic response only at high concentrations (10(-4) M), whereas Tolazoline applied during the tonic phase was an effective relaxant at lower concentrations. Acetylcholine added to the bath during an alpha 1-adrenergic contraction induced relaxation at low concentrations and contraction for higher concentrations. The relaxation was eliminated by removal of the endothelial cell layer. These data support the notion that the phasic component of an alpha 1-adrenergic contraction is mainly dependent on intracellular Ca2+ stores whereas the tonic component relies almost exclusively on extracellular Ca2+. It is suggested that Ca2+ channel blockers and alpha 1-adrenergic antagonists may potentially play a role in relaxing the ophthalmociliary artery to improve the ocular circulation in vascular diseases in which there is considerable vascular tone present.


Surgical quality control in an international randomized clinical trial. One of the current international prospective clinical trials of the EORTC Melanoma Cooperative Group explores the usage of regional isolated perfusion as adjuvant in melanomas located on the extremities. In the design of the study it is necessary to define not only the extent of the surgery (perfusion+local excision versus local excision only), but also to ensure uniformity of surgery performed between surgeons and institutions. With on-site visits and general meetings with the participants, surgical protocol violations and misinterpretations of the protocol could be avoided. The conclusion is that accurate surgical quality control is time consuming, but not difficult.


Study of tissue compression in breast phantoms: possible implications for the use of X-ray mammography as a method of imaging breast carcinoma. A method is described of constructing a simple phantom breast containing an idealised tumour with elastic properties. The transparent tissues are compressed and evidence is adduced to show that with tissue compression the tumour boundary is subjected to a degree of strain the magnitude of which is dependent on the degree of deformation. Excessive compression can lead to fracture of the tumour. A literature survey reveals that malignant tissues are more delicate than normal tissues. The study underlines the need for care when using X-ray mammography with compression to image a cancer bearing breast, in order to avoid disseminating cancer cells via the circulation.


Esophageal carcinoma: prognostic features and comparison between blunt transhiatal dissection and transthoracic resection. Among 86 patients who underwent resection for thoracic esophageal carcinoma between 1982 and 1989, 49 were resected by a transhiatal blunt esophagectomy (THE) and 37 underwent a transthoracic-abdominal esophagectomy (TTE). The two groups were statistically comparable with respect to preoperative characteristics. Overall morbidity and respiratory complications were high for both groups (71% vs 62% and 45% vs 46%; P = NS). The rate of cardiac, renal, neurological and bleeding complications, as well as recurrent nerve injuries was similar in both groups. An anastomotic leak occurred in 39% (19/49) of THE patients and in 11% (4/37) (P < 0.05) of TTE patients. Hospital mortality was 16% (8/49) in the THE group (4 resulting from cervical anastomotic leaks, 4 from respiratory complications) and 13% (5/37) in the TTE patients (1 from myocardial infarction, 4 from respiratory failures; P = NS). Actuarial survival curves for all THE and TTE patients (5-year survival rate: 20% vs 22%) and separate analysis for N0 and N1 tumors revealed no significant difference between these two techniques. Of the different preoperative variables, only tobacco addiction, beside lymph node involvement, was an independent predictor of outcome. Respiratory complications and hospital mortality were significantly lower for the non-smokers and long term survival was significantly higher for the N0 stages.


Esophageal squamous cell carcinoma: the specific limited place of surgery defined by a prospective multivariate study of prognostic factors after surgical approach. From 1982 to 1990, 181 patients underwent surgery for esophageal squamous cell carcinoma, for which 14 prognostic parameters were prospectively recorded in order to perform a multivariate study. A squamous cell head and neck cancer was associated with the esophageal tumor in 40% of the cases (synchronous 18% and metachronous 22%). Resection was curative (i.e. macroscopically complete) in 128 cases, palliative (i.e. with residual tumor) in 24 cases and not possible in 29 cases. There were 21 deaths in hospital (hospital mortality was 11.7%). One hundred and twenty-two patients received preoperative chemotherapy and 77 received postoperative radiotherapy according to different phase II prospective studies. The 5-year survival rate according to the Kaplan-Meier method was 15.8% (+/- 3.4) for all patients and 23.5% (+/- 4.8) for the patients who had a curative resection. A palliative resection or the invasion of a neighbouring organ was synonymous with incurability, but positive lymph nodes were not considered proof of incurability. The multifactorial study concerning all the patients highlighted two main prognostic parameters: the histological staging according to the Japanese classification (P = 0.0006) and the type of resection (curative or not) (P = 0.006). An objective response to preoperative chemotherapy was the third and last parameter revealed by Cox's model. The multivariate study, which was limited to the 112 patients who were alive after a curative resection, showed that only the stage was an important prognostic factor (P = 0.003), with stages 2 and 3 carrying a worse prognosis. We propose a therapeutic scheme, based on these prognostic data and on the usual pre-therapeutic workup with three additional exams: CT scan measurement of tumor diameter, ultrasound examination +/- fine needle aspiration cytology of supra-clavicular lymph nodes and echo-endoscopy. The aim of this scheme is to limit surgery to the subgroup of patients for whom this modality is really beneficial.


Total versus subtotal gastrectomy in cancer of the distal stomach: facts and fantasy. The purpose of this review is to analyse critically the pros and cons of 'en principle' total gastrectomy for cancers of the distal stomach. The theoretical advantages of total gastrectomy would be the guarantee of no infiltration of the margin of proximal transection owing to multicentric cancers or to a microscopical intramural spreading of tumoral cells beyond the macroscopically detectable boundaries of the lesion. However, these expectations are not substantiated since multicentric tumours are rare, a safe margin of resection can be achieved maintaining a proximal clearance of 6 cm from the cranial edge of the tumour. Moreover, recurrences confined to the gastric stump, after subtotal gastrectomy (and originally preventable with a total gastrectomy) are extremely rare according to literature. Furthermore, current experience suggests that the extent of lymph node dissection is not affected by the extent of the resection of the stomach. Analysis of the published series of patients undergoing an en principle total gastrectomy fails to demonstrate any advantage for long-term survival compared with patients treated by subtotal gastrectomy. A recent randomized trial comparing these two procedures is in keeping with the above-mentioned conclusions. It is true, however, that the gap in surgical mortality for total and subtotal gastrectomy tends to disappear when total gastrectomy is electively performed in patients with tumours of the distal stomach. So, whereas the long-term oncological results of the two surgical procedures seem to be similar, the main disadvantage of total gastrectomy is the onset of malnutrition, which is common, but incapacitating only in a few patients. This condition is likely to be of relevance should the patients be selected for aggressive postoperative adjuvant treatments which require good general status and nutritional integrity. The main disadvantage of subtotal gastrectomy is that the patients are exposed to the risk of a gastric stump cancer. However, this risk, owing to the advanced median age of the resected patients and the actual reconstructive procedures which minimize the biliary reflux, cannot be quantified. We think that when two surgical procedures are compared, if the oncological results are the same, the operation which is associated with least discomfort and impairment of the quality of life, should be chosen.


Smooth muscle tumors of the gastrointestinal tract. A 10-year experience. Benign or malignant smooth muscle tumors of the gastrointestinal tract are uncommon. The diagnostic and therapeutic approaches vary depending on the histological behavior of these neoplasms. Between 1981 and 1991, 32 patients with gastrointestinal tumors were treated at the Department of Surgery of the University of Patras. There were 16 females and 16 males. The mean age at the time of diagnosis was 61.9 years (range 22-83 years). Eighty-one per cent of the tumors were discovered in asymptomatic patients by a variety of diagnostic studies. Fifty-six per cent of tumors were located in the stomach, 38% in the small intestine and 6% in the colon. Leiomyomas made up 71.8% of these tumors and were treated by conservative excision. The malignant smooth muscle tumors were treated by radical excision in four cases and conservative excision in one case. The 5-year survival rate was 85% for leiomyomas and 0% for malignant smooth muscle tumors. There is widespread agreement that wide resection of the lesion is the appropriate treatment for these tumors. The size and mitotic activity of these tumors remain the most important diagnostic parameters and prognostic factors.


Flow cytometric DNA analysis in Japanese colorectal cancer. A multivariate analysis. Using Cox's proportional hazard model, we performed a multivariate analysis of survival data from 126 patients who underwent curative resection for colorectal cancer from 1971 to 1985. Flow cytometric DNA measurements were carried out using paraffin wax-embedded tissue blocks. Fifty-four per cent of the cases were found to be aneuploid and 46% were diploid. The depth of invasion of the tumor, nodal status, liver metastasis, peritoneal dissemination, DNA ploidy pattern, histology, macroscopic classification of the tumor, age, sex and site were tested in a survival analysis. The initial seven factors were found to be the significant prognostic variables in a univariate analysis. A multivariate analysis shows liver metastasis, DNA ploidy pattern and peritoneal dissemination as being the significant discriminants of survival (P = 0.0001, 0.0022, 0.0119, in this order). Therefore, nuclear DNA ploidy pattern in colorectal cancer is considered to be an independent prognostic factor.


A phase 2 trial of recombinant interleukin-2 and 5-fluorouracil in patients with metastatic colorectal carcinoma. The toxicity and efficacy of sequential 5-fluorouracil (5-FU) and recombinant interleukin-2 (IL-2) were evaluated in 12 patients with metastatic colorectal carcinoma. This combination of 5-FU and IL-2 produced a 10% partial response rate with 40% of patients remaining in stable disease while on therapy. No clear improvement in survival was demonstrable. In contrast to the disappointing response rates the overall level of toxicity was very low with no treatment related deaths. It is concluded that modifications in treatment schedules are required before further similar studies are commenced.


Polyadenylic-polyuridylic acid as an adjuvant in resectable colorectal carcinoma: a 6 1/2 year follow-up analysis of a multicentric double blind randomized trial. In a double blind study, patients with operable carcinoma of the colon and the upper rectum, who have undergone a macroscopically complete resection of their tumor, were randomized to receive either (i) polyadenylic-polyuridylic acid (AU), one i.v. injection of 60 mg (in 50 ml of solution) once a week for 6 weeks, or (ii) a placebo (P) one i.v. injection of 50 ml of a saline solution with the same schedule. From January 1983 to December 1986, 288 patients were enrolled: 145 in AU group and 143 in P group. The main clinical and pathological characteristics were equally distributed throughout the two groups. There was a significant difference (P < 0.02) in the overall survival (OS) between the two groups, in favor of the P group. The 5-year OS rate was 68% (SD = 4%) in the AU group versus 81% (SD = 3%) in the P group. Thus, AU as a single adjuvant, appears to be ineffective and therefore has no indication in the treatment of colorectal carcinoma.


Fine needle aspiration biopsy of solid tumours by auto-vacuum system: a study in rats. A fine needle aspiration biopsy (FNAB) device was designed to utilize a steel spring located between the syringe and its plunger, which exerts a constant negative pressure (auto-vacuum). In 43 rats inoculated with breast tumour cells, the technique was compared with the standard procedure of FNAB (21 Sp1 and 22 Walker256 carcinosarcoma). Malignant cells were cytologically confirmed in all cases. Sufficient material was obtained in 95% of FNAB by auto-vacuum system versus 86% by standard technique. The superior results obtained with the auto-vacuum system was seen for both soft and hard tumours.


Induction and quantification of hepatic metastases from a human colonic cancer in the nude rat. Nude rats were injected with human colonic cancer cells (LS 174 T) in the superior mesenteric vein and the extent of hepatic metastases at sacrifice was estimated by visual inspection and computer-based area calculation. After 3 weeks, 5.0 x 10(6) cells caused hepatic metastases in 14/14 rats whereas 0.5 x 10(6) cells failed to produce liver metastases in 4/4 rats (P < 0.001). Injection of 1.0 x 10(7) cells caused portal vein occlusion in 3/5 rats. Extrahepatic tumour growth was rare; lung metastases were observed in four rats, and three rats had local tumour in the abdomen. The average extent of hepatic tumour replacement was 20.2 +/- 4.0%. Injection of embolies or single cells did not affect the incidence or extent of hepatic metastases. The incidence of hepatic metastases was similar in male and female rats, but the extent of hepatic tumour was larger in males (24.6%) than in females (3.2%) (P = 0.005). The pathophysiological similarities to human disease should make this model suitable for diagnostic and therapeutic studies with clinical application.