A comparison of the actions of cilazapril in normal, dietary sodium-depleted and two-kidney, one clip Goldblatt hypertensive anaesthetised rats. This study aimed to examine the role of the renin-angiotensin system in the regulation of kidney haemodynamic and excretory function when angiotensin II levels were modestly and markedly raised. Three groups of male Sprague-Dawley rats were used: control rats fed a sodium-replete diet; rats fed a sodium-deficient diet for 2 weeks; and two-kidney, one clip (2K1C) Goldblatt hypertensive rats, 4-5 weeks postclipping. The rats were acutely anaesthetized with sodium pentobarbitone and prepared for renal function measurements. The converting enzyme inhibitor, cilazapril, was then infused at increasing dose levels to progressively block the renin-angiotensin system. Cilazapril did not affect blood pressure in sodium-replete animals; it raised RBF and increased water and sodium excretion. In dietary sodium-depleted rats, cilazapril decreased blood pressure and increased RBF, water and sodium excretion at the lower doses of the drug; however, at vasodepressor doses, water and sodium excretion fell towards baseline values. In 2K1C Goldblatt hypertensive rats, cilazapril maximally decreased blood pressure whilst the non-clipped kidney blood flow, filtration rate and fluid excretion rates were similar to dietary sodium-depleted rats; in contrast, the clipped kidney filtration rate was well maintained and fluid excretion was raised in a dose-related fashion. These results show that during gradual cilazapril administration, renal function is well preserved in 2K1C Goldblatt hypertensive rats when pressure is progressively reduced.


Effects of lisinopril upon cardiac hypertrophy, central and peripheral hemodynamics and neurohumoral factors in spontaneously hypertensive rats. Left ventricular function (LVF) after reversal of left ventricular hypertrophy (LVH) with antihypertensive therapy is still controversial. The present study was undertaken in spontaneously hypertensive rats (SHR) to determine whether LVF of the regressed heart with lisinopril is normally maintained. We compared cardiac function of SHR after reversal of LVH induced by lisinopril with that observed in control SHR and also with effects after a 4-week washout period. Administration of lisinopril began at 15 weeks of age and continued for 20 weeks. Cardiac index, renal blood flow, leg muscle blood flow, plasma renin activity, atrial natriuretic peptide level, and norepinephrine concentration were determined. Lisinopril decreased body weight, blood pressure and left ventricular weight and increased leg muscle blood flow; cardiac index and renal blood flow were unaltered. Although norepinephrine concentration was unchanged, plasma renin activity increased and atrial natriuretic peptide decreased in treated SHR. Peak left ventricular pumping ability during volume loading was comparable in the two groups. After a 4-week washout period, left ventricular mass and blood pressure increased but remained lower than controls; cardiac index at rest and during volume loading was similar in the two groups. These data indicate that LVF of the regressed heart induced by lisinopril was well preserved at rest, during volume loading and also after spontaneous recurrence of hypertension in SHR.


Blunted effects of endothelin upon small subcutaneous resistance arteries of mild essential hypertensive patients. In experimental models of hypertension in the rat, resistance arteries present a blunted response to endothelin, a potent vasoconstrictor peptide. The primary objective of this study was to investigate whether, as in hypertensive rat blood vessels, the response of human resistance arteries to endothelin was altered in essential hypertensive patients, in order to further understand the possible physiopathological involvement of this peptide in human hypertension. Normotensive male subjects and sex- and age-matched mild essential hypertensive patients who had not received antihypertensive drugs for more than 6 months were investigated. Small arteries were dissected from gluteal subcutaneous biopsies and mounted on a wire-myograph. Blood vessels were measured and dose-response curves to different agents tested. The external diameter of blood vessels of the hypertensive patients tended to be smaller and the width of their media tended to be thicker, but the cross-sectional area of the wall was similar in both groups. Lumen diameters were significantly smaller in hypertensives and the media:lumen ratio was significantly increased in hypertensive patients. Active tension responses and sensitivity to norepinephrine, arginine vasopressin and angiotensin II were similar in both groups, but calculated active pressure responses were enhanced in hypertensives due to the smaller blood vessel lumen. Tension responses to endothelin-1 at increasing concentrations of 0.1 to 100 nmol/l were lower in hypertensive patients, but the calculated transmural active pressure developed was not significantly different at or above 10 nmol/l. These results suggest that gluteal subcutaneous small resistance arteries of male essential hypertensive patients exhibit a decrement in responsiveness to endothelin-1. The altered design of the hypertensive blood vessels enhanced calculated pressure responses, which may contribute to the maintenance of elevated blood pressure.


Atrial natriuretic peptide suppresses isoprenaline and dibutyryl cyclic adenosine monophosphate-induced cell growth in cultured renin-secreting human nephroblastoma cells. Comparison with forskolin-induced renin secretion. Renin secretion in response to long-term exposure to isoprenaline, dibutyryl cyclic adenosine monophosphate (dbcAMP), forskolin and atrial natriuretic peptide (ANP) was measured in cultured human nephroblastoma cells. Human nephroblastoma cells in culture were treated long-term (1-12 days) with isoprenaline, dbcAMP or forskolin, alone or in combination with ANP; renin release and cell growth were studied. The increase in renin output caused by isoprenaline and dbcAMP could be accounted for by stimulation of cell growth. The effect of isoprenaline was blocked by propranolol. Forskolin stimulated renin secretion per cell. ANP increased extracellular cyclic guanosine monophosphate and suppressed basal renin output. Suppression of basal renin output was due to a reduced secretion rate per cell, without a change in cell growth. ANP suppressed isoprenaline-induced and dbcAMP-induced renin output by blocking increased cell growth, and forskolin-induced renin output by blocking renin secretion. These results suggest that beta-receptor agonists and ANP interact within the kidney to control renin secretion, by helping to determine the number of renin-secreting cells.


Atrial natriuretic peptide increases human capillary filtration and venous distensibility. The main aim of this study was to examine whether atrial natriuretic peptide (ANP) alters capillary filtration and venous distensibility. The study was designed to examine the local effects of i.a. infusion of ANP upon capillary filtration and venous distensibility in human forearms of eight healthy volunteers. Using a water plethysmograph, we measured venous distensibility and capillary filtration from changes in forearm volume when transmural venous pressure was increased in a stepwise manner and held constant during i.a. infusion of saline, ANP and sodium nitroprusside (SNP). The doses of ANP and SNP were chosen to double baseline forearm blood flow obtained during saline infusion. ANP and SNP infusion both increased venous distensibility to the same extent compared with saline infusion. Capillary filtration was greater during ANP than during saline or SNP infusion. Small vein pressure was comparable during infusion of the two drugs. Our results suggest that ANP increases venous distensibility and capillary filtration in human forearms.


Reduced venous compliance in normotensive men with positive family histories of hypertension. To test the hypothesis of reduced venous compliance and increased cardiovascular responses to volume expansion and alpha-agonist stimulation. Non-hypertensive healthy young men with positive (PFH) and negative family histories of hypertension were investigated regarding peripheral haemodynamics and changes in central venous pressure (CVP) and arterial blood pressure in response to graded doses of phenylephrine and acute i.v. fluid volume loading (1000 saline solution in 10 min). The control group was divided into one group matched for body mass index to PFH subjects (NFHO) and one lean control group (NFHN). Supine blood pressure was higher in PFH and NFHO subjects compared with NFHN subjects, whilst CVP was similar in the three groups at baseline. No significant differences in calf or forearm haemodynamics or blood volume were observed between the three groups. Cardiovascular responses to bolus doses of phenylephrine did not differ between the three groups. Saline infusion significantly increased CVP and systolic blood pressure, and effective vascular compliance (change in blood volume: CVP ratio) was reduced in PFH subjects. PFH subjects have decreased effective vascular compliance and altered arterial blood pressure responses to acute increases in vascular fluid volume. This may result from multiple factors such as increased venous vascular tone, structural reduction of venous distensibility and/or an altered neurohormonal response to increased CVP.


Rheological determinants of blood pressure in a Scottish adult population. To examine the relationship of blood pressure with haematocrit, plasma viscosity, whole blood viscosity and plasma fibrinogen. A random population sample of 1264 men and women aged 25-64 years from the west of Scotland, UK. Strong correlations between age, body mass index and blood pressure were noted: these were higher for women than men. Blood viscosity, haematocrit and plasma viscosity correlated with blood pressure independently of age, body mass index and smoking status. No evidence was found for an effect of erythrocyte rigidity upon blood pressure; plasma fibrinogen showed an inverse correlation with blood pressure and the rheological variables on multivariate analysis. Our findings support the role of blood viscosity in determining blood pressure as suggested by other, smaller studies. The magnitude of the effect upon blood pressure levels across the normal range of blood viscosity was of clinical importance. Further studies of factors that influence blood and plasma viscosity may help in the understanding of the aetiology of essential hypertension and its management.


Atrial natriuretic factor improves renal function and lowers systolic blood pressure in renal allograft recipients treated with cyclosporin A. Atrial natriuretic factor (ANF) has several properties which suggest that it may ameliorate cyclosporin A nephrotoxicity. We therefore investigated the response to a pharmacological dose of ANF in renal transplant recipients treated with cyclosporin A. A single-blind randomized crossover design comparing the renal and haemodynamic effects of D-glucose (placebo) with ANF. Seven patients with stable renal function following renal transplantation were studied under maximal water diuresis. Glomerular filtration rate and effective renal plasma flow were estimated from clearances of inulin and para-aminohippurate, respectively. Plasma ANF levels increased significantly in association with increased diuresis and natriuresis. Glomerular filtration rate was unchanged after placebo but increased significantly after ANF fusion. Likewise, effective renal plasma flow increased significantly with ANF infusion. There was a significant fall in systolic blood pressure, with no apparent change in heart rate and diastolic blood pressure. These results suggest that ANF may have beneficial effects in protecting against cyclosporin A-induced nephrotoxicity and hypertension.


The treatment of obese hypertensive black women: a comparative study of chlorthalidone versus clonidine. We attempted to determine a valid pharmacological approach for the control of high blood pressure in obese hypertensive patients using two antihypertensive agents with different pharmacological actions. Thirty-two obese hypertensive black women were randomly treated with chlorthalidone or clonidine to achieve adequate blood pressure control. Unresponsive patients received combination therapy with both agents. Twenty-nine patients completed the study. Systolic and diastolic blood pressures were reduced with both agents, more so with chlorthalidone. Of the 15 patients treated with chlorthalidone, 14 had satisfactory reduction in diastolic pressure compared with only four of the 14 treated with clonidine. Of the 11 unresponsive patients treated with combination therapy, 10 achieved satisfactory control of blood pressure. We conclude that a rational approach to the treatment of hypertension in obese black women includes diuretics, a first choice attempt that tries to address the hemodynamic alterations previously identified in those patients. Combining diuretics with an alpha-adrenergic agonist resulted in complete control of blood pressure in most of the hypertensive patients in our study. The lowest dose of each antihypertensive medication, especially when used in combination, was effective in a high percentage of patients. The use of this antihypertensive approach also helps to clarify which of the underlying pathophysiological mechanisms should be targeted when other currently available antihypertensive medications are used.


Persistent blood pressure increase induced by heavy smoking. To test the hypothesis that heavy smoking is associated with a persistent increase in blood pressure. In 10 normotensive smokers asked to smoke one cigarette every 15 min for 1 h, blood pressure and heart rate were continuously monitored during the smoking period and during the preceding non-smoking hour. In six other normotensive smokers asked to smoke two cigarettes per hour throughout the whole day, blood pressure and heart rate were monitored non-invasively in ambulatory conditions for 8 h (0900-1700 h). Blood pressure monitoring was repeated during a non-smoking day. Beat-to-beat blood pressure and heart rate were monitored at rest by means of the Finapres device. Blood pressure signal was sampled at 165 Hz by a computer to calculate hourly data. Ambulatory blood pressure and heart rate were measured once every 10 min. In resting conditions, the first cigarette caused an immediate and marked increase in blood pressure and heart rate, and the peak blood pressure and heart rate achieved were similar for the remaining three cigarettes. In each instance, the hemodynamic effects were so prolonged that throughout the smoking hour, blood pressure and heart rate were persistently higher than during the non-smoking hour. The standard deviations of systolic and diastolic blood pressure and heart rate were also higher during the smoking hour, indicating an increase in blood pressure and heart rate variability. In the six ambulant smokers, daytime blood pressure and heart rate were also persistently higher during smoking than during non-smoking. Heavy smoking is associated with a persistent rise in blood pressure and also with an increase in blood pressure variability. These effects (which may escape clinic blood pressure measurements performed during non-smoking) may account for some of the smoking-related cardiovascular risk.


Implementation of the postdischarge follow-up call in the patient care units. The Telephone Call Back System was implemented from October 1989 in the Inpatient and Ambulatory Care Units as a postdischarge follow-up and as an evaluation of the patients' hospital experience. Nurses called patients discharged from the Ambulatory Care Unit within 24 hours postdischarge and within 24-48 hours from the Inpatient Unit. Questions asked included present physical status, ocular discomfort, availability of assistance at home, and if there were any questions and concerns. For the year 1990, 77 percent of the patients discharged from the Ambulatory Care Unit were called and 71 percent were contacted. From the Inpatient Unit, 89 percent were called and 68 percent were contacted. Patient response required the following nursing interventions: review of discharge instructions, referral to an ophthalmologist and/or an internist, referral to a patient representative/social worker, reassurance on ocular signs and symptoms consistent with a normal postsurgical period, and patient teaching other than ophthalmic care. Patients discharged from the Inpatient Unit required more nursing intervention than patients discharged from the Ambulatory Care Unit. More than 99% of the patients discharged in both patient care units were satisfied with their hospital care. These results indicate the importance of postdischarge follow-up in the continuity of health care and in the transition from the health care institution to the home setting.


Aminoglycoside antibiotics block voltage-dependent calcium channels in intact vertebrate nerve terminals. Intrinsic and extrinsic optical signals recorded from the intact nerve terminals of vertebrate neurohypophyses were used to investigate the anatomical site and physiological mechanism of the antagonistic effects of aminoglycoside antibiotics on neurotransmission. Aminoglycoside antibiotics blocked the intrinsic light scattering signal closely associated with neurosecretion in the mouse neurohypophysis in a concentration-dependent manner with an IC50 of approximately 60 microM and the block was relieved by increasing [Ca2+]o. The rank order potency of different aminoglycoside antibiotics for blocking neurosecretion in this preparation was determined to be: neomycin greater than gentamicin = kanamycin greater than streptomycin. Optical recordings of rapid changes in membrane potential using voltage-sensitive dyes revealed that aminoglycoside antibiotics decreased the Ca(2+)-dependent after-hyperpolarization of the normal action potential and both the magnitude and after-hyperpolarization of the regenerative Ca2+ spike. The after-hyperpolarization results from a Ca-activated potassium conductance whose block by aminoglycoside antibiotics was also reversed by increased [Ca2+]o. These studies demonstrate that the capacity of aminoglycoside antibiotics to antagonize neurotransmission can be attributed to the block of Ca channels in the nerve terminal.


Cisplatin neuropathy: clinical course and neurophysiological findings. Sixteen patients treated with cisplatin (CDDP) 40 mg/m2 on days 1-5 every 4 weeks for three courses (cumulative dose 600 mg/m2) were clinically and neurophysiologically tested before, during and 1, 3, 6, 9 and 12 months after CDDP administration. The first symptoms of polyneuropathy occurred in 4 of 9 patients after the second course (cumulative dose 400 mg/m2). One month after treatment 1 of 9 patients was asymptomatic, 5 complained of symptoms and 3 showed clinical and neurophysiological signs of polyneuropathy. Three months after CDDP all patients were affected. Clinical and neurophysiological signs of severity progression were noted up to 6 months after treatment with CDDP.


Early diagnosis and successful treatment of acute cytomegalovirus encephalitis in a renal transplant recipient. We report the case of a 40-year-old male HIV-negative renal transplant patient with allograft rejection and immunosuppressive therapy who presented with acute cytomegalovirus (CMV) encephalitis. CT and MRI of the brain were normal but EEG showed diffuse slowing and dysrhythmia. In cerebrospinal fluid (CSF) initially 81 cells/microliters were found and immunocytochemistry showed a decreased CD4/CD8 ratio and increased values of activated lymphocytes, natural killer cells and immunoglobulin-containing cells. CMV-specific IgM antibodies in CSF and serum, immunostaining of CMV antigen in CSF cells and virus culture from CSF and urine were negative. During the first 3 weeks of illness no intrathecal production of immunoglobulins could be detected. Early diagnosis of CMV encephalitis was made by in situ hybridization (ISH) on CSF cell preparations and the polymerase chain reaction (PCR) which was positive in CSF and blood. On day 26 diagnosis was confirmed by detection of CMV-specific intrathecal IgG production. The patient was treated with ganciclovir, anti-CMV immunoglobulins and intrathecal beta interferon. He recovered completely after 2 months. Our data demonstrate the usefulness of ISH and PCR in the early diagnosis of CMV encephalitis and perhaps may encourage the use of intrathecal beta interferon in other patients with this disease.


Light-evoked changes in [K+]o in proximal portion of light-adapted cat retina. 1. The M-wave is a light-adapted response of proximal retina consisting of phasic negative field potentials at light onset and offset that are spatially tuned for small stimuli. We measured light-dependent changes in extracellular K+ concentration ([K+]o) in proximal retina to investigate the hypothesis that the M-wave originates from Müller cell responses to changes in [K+]o. 2. Extracellular field potentials, and changes in [K+]o evoked in response to circular spots of light flashed on steady backgrounds, were recorded with double-barreled K(+)-sensitive electrodes placed in the retina at different depths. 3. Increases in [K+]o during illumination and at light offset were maximal in proximal retina, with the On [K+]o increase located more proximally than the Off increase. The [K+]o increase during illumination consisted of a phasic and sustained response, whereas the Off [K+]o increase was predominantly phasic. The spatial tuning of the [K+]o increases was similar to the tuning of the field potentials. 4. The Off-field potential was larger than the On potential; it tended to be maximal more distally and was more sharply localized in retinal depth. Stimulus-response characteristics of the field potentials were not altered by intravitreal tetrodotoxin (TTX; 3.8 microM) sufficient to block retinal ganglion cell action potentials. 5. There were no rod contributions to the proximal [K+]o increases and field potentials recorded at the background illuminations used in this study (9.5-11.5 log q.deg-2.s-1). 6. An intravitreal injection of L- or DL-2-amino-4-phosphonobutyric acid (APB; 1 mM) was used to block On-system neuronal responses in proximal retina and isolate Off-system responses. After APB the [K+]o response consisted of a sustained decrease in [K+]o during illumination followed by an overshoot at light offset, while the field potential was a sustained positive response at light onset followed by an initially phasic negative response at light onset followed by an initially phasic negative response at light offset. These responses retained spatial tuning. To isolate the On-system components, the APB-isolated responses were subtracted from the controls. The [K+]o response now consisted of a sustained increase during illumination followed by an undershoot at light offset. The field potential was a sustained negative potential with an initial phasic peak that decayed at Off. Results with kynurenate (KYN; 5 mM) and (+/-)cis-2,3-piperidine (PDA; 5 mM) confirmed the sustained nature of the On component.(ABSTRACT TRUNCATED AT 400 WORDS)


Effectiveness of absorbable fixation devices in Austin bunionectomies. Forty-eight Austin bunionectomies were fixated by using an absorbable fixation device. Twenty-three were fixated with a 1.5- or 2.0-mm diameter Biofix rod and twenty-five were fixated with a 1.3-mm diameter Orthosorb pin. To be included in this project, all patients were followed radiographically for a minimum of 3 months. One foot (4%) fixated with Biofix developed a sterile sinus discharge 3 months postoperatively after uneventful wound healing. There were no clinical or radiographic changes seen in the feet in which Orthosorb was used. Also, there were no infections or osteotomy dislocations with either fixation device.


Edward E. Smissman-Bristol-Myers Squibb Award Address. The role of concepts in structure-activity relationship studies of opioid ligands. Various concepts have served as the basis for the development of models to explore the relationship between molecular structure and biological activity. In this presentation I have outlined five concepts that have been useful in our investigation of opioid receptor multiplicity and in the design of selective opioid receptor antagonists. The first of these, the multiple binding modality concept, led to our application of four other concepts in the development of opioid receptor probes. Some of these probes are now standard tools in opioid research. These include the mu-selective affinity label beta-FNA (10), the kappa opioid receptor antagonist norBNI (15), and the delta opioid antagonist NTI (20). These highly selective antagonists have advantages over the universal opioid antagonists naloxone and naltrexone because they are of value in probing the interaction of endogenous opioid peptides with opioid receptor types. Additionally, they are useful in evaluating the selectivity of new opioid agonists. Also, selective opioid antagonists have potential clinical applications in the treatment of a variety of disorders where endogenous opioids play a modulatory role. These include constipation, immune function, drug addiction, and alcoholism, to name only a few.


Structure and molecular modeling of GABAA receptor antagonists. The recently described potent and selective GABAA antagonist SR 95531 (gabazine) is compared to six other GABAA antagonists: (+)-bicuculline, (-)-securinine, (+)-tubocurarine, iso-THAZ, R-5135, and pitrazepine. Starting from ab initio molecular orbital calculations performed on crystal atomic coordinates, attempts were made to identify in each structure the functional groups that are involved in receptor recognition and binding. A molecular modeling study revealed that (a) all compounds possess accessible cationic and anionic sites separated by an 4.6-5.2 A intercharge distance, (b) the antagonistic nature of the compounds can be explained by the presence of additional binding sites, (c) the correct spatial orientation of the additional binding sites is crucial for GABAA selectivity, and (d) the criteria determining the potency of the antagonist effect are an accurate intercharge distance (greater than 5 A) and the existence of hydrogen-bonding functionalities on one of the additional ring system. The presented pharmacophore accounts also for the inactivity of closely related compounds such as (-)-bicuculline, adlumidine, virosecurinine, allosecurinine, and the 4,6-diphenyl analogue of gabazine.


Highly water-soluble lipophilic prodrugs of the anti-HIV nucleoside analogue 2',3'-dideoxycytidine and its 3'-fluoro derivative. The synthesis of a novel series of lipophilic prodrug derivatives of the anti-HIV drugs 2',3'-dideoxycytidine (ddC, 1) and 3'-fluoro-ddC (2), involving N4-substitution with (N,N-dialkylamino)methylene side chains, is described. The increase in the partition coefficients for the prodrug series, compared to those of the parent drugs 1 and 2, ranged from 1.5- to 122-fold and from 1.6- to 175-fold, respectively. At pH 7.4, 37 degrees C, the hydrolytic t1/2 values ranged from 2 to 52 h, the diisopropyl derivatives (3d and 4d) being most stable in the series. 3d and 4d were greater than or equal to 4-fold and 1.7-fold more soluble in water than 1 and 2, respectively. The in vitro antiretroviral activities of 3d, 4a, and 4d were evaluated; the results indicate efficient prodrug-to-drug conversion under the assay conditions. The results of this investigation demonstrate that it is indeed feasible to chemically modify certain nucleoside analogues with inferior solubility properties to simultaneously achieve significantly enhanced lipid and water solubility.


Benz[f]isoquinoline analogues as high-affinity sigma ligands. This paper describes the synthesis of some conformationally restricted 4-phenylpiperidine analogues and their affinities for the guinea pig cerebellum sigma recognition site ([3H]-DTG) and the rat striatum dopamine D2 receptor ([3H]-(-)-sulpiride) in order to develop potent selective sigma ligands as tools in the investigation of this site in psychosis. It was found that both hexa- and octahydrobenz[f]isoquinolines with lipophilic N-substituents had high affinities for the sigma site. Notably, trans-3-cyclohexyl-1,2,3,4,4a,5,6,10b-octahydrobenz[f]isoquinoline (26) had an affinity of 0.25 nM making it the highest affinity sigma ligand reported to date. Moreover, it is at least 10,000-fold selective over the D2 receptor and could prove to be a valuable tool in the study of sigma sites. Other analogues such as 1H-indeno[2,1-c]pyridines and 1H-benzo[3,4]cyclohepta[1,2-c]pyridines also displayed high sigma site affinity.


Spiropiperidines as high-affinity, selective sigma ligands. A variety of achiral conformationally restricted spirocyclic piperidines have been prepared in an attempt to investigate the functional role of the central sigma recognition site. All the compounds possessed a lipophilic N-substituent incorporating either a tetralin, indan, or benzocycloheptane skeleton. Their in vitro affinity at the sigma site was assessed in radioligand displacement experiments with guinea pig cerebellum homogenates using the sigma-specific radioligand [3H]-N,N'-di-o-tolylguanidine ([3H]-DTG, [3H]-6). A study of the structure-activity relationships identified the N-butyl and N-dimethylallyl substituents as the optimum groups for high affinity and selectivity at the sigma site (e.g., 3,4-dihydro-1'-(3-methylbut-2-enyl)spiro[1H-indene-1,4'-piperidine ] (48), pIC50 = 8.9 vs [3H]-6 and greater than 10,000-fold selective over the dopamine D2 receptor). Such compounds are amongst the highest affinity sigma ligands reported to date, with excellent selectivity over the dopamine D2 receptor, and may serve as a useful tool for exploring the physiological role of the sigma site.


Synthesis and structure-activity relationships of a series of novel benzopyran-containing platelet activating factor antagonists. A class of N-substituted tetrahydrobenzopyrano[3,4-c]pyridines, I, have been identified as antagonists of platelet activating factor (PAF). The structural features essential for PAF binding were determined by systematic modification of three sites in the molecule. While O-alkyl analogues had little effect on binding potency, N-alkyl analogues exhibited a wide range of activity. Structural changes in the core ring system generally resulted in a loss of binding activity. Optimization of the N- and O-substituents resulted in the analogues 25-27 which exhibited Ki values ranging between 131 and 167 nM in a [3H]PAF binding assay. Compound 23 was also active in a model of PAF-induced shock in the mouse following intravenous administration.


A novel probe for the cannabinoid receptor. The 1,1-dimethylheptyl (DMH) homologue of 7-hydroxy-delta 6-tetrahydrocannabinol (3) is the most potent cannabimimetic substance reported so far. Hydrogenation of 3 leads to a mixture of the epimers of 5'-(1,1-dimethylheptyl)-7-hydroxyhexahydrocannabinol or to either the equatorial (7) or to the axial epimer (8), depending on the catalysts and conditions used. Compound 7 discriminates for delta 1-THC (2) in pigeons (ED50 = 0.002 mg/kg, after 4.5 h), at the potency level of 3, and binds to the cannabinoid receptor with a KD of 45 pM, considerably lower than the Ki of 180 pM measured for compound 3 and the Ki of 2.0 nM measured for CP-55940 (1), a widely employed ligand. Tritiated 7 was used as a novel probe for the cannabinoid receptor.


Oat products and lipid lowering. A meta-analysis. To test the a priori hypothesis that consumption of oats will lower the blood total cholesterol level and to assess modifiers and confounders of this association. A computerized literature (MEDLINE) search and the Quaker Oats Co identified published and unpublished trials as of March 1991. Raw data were requested for all trials. Trials were included in summary effect size estimates if they were randomized and controlled, if a formal assessment of diet and body weight changes occurred, and, if raw data were not received, if there was enough information in the published report to perform calculations. Twenty trials were identified. Using the methods of DerSimonian and Laird, a summary effect size for change in blood total cholesterol level of -0.13 mmol/L (-5.9 mg/dL) (95% confidence interval [CI], -0.19 to -0.017 mmol/L [-8.4 to -3.3 mg/dL]) was calculated for the 10 trials meeting the inclusion criteria. The summary effect size for trials using wheat control groups was -0.11 mmol/L (-4.4 mg/dL) (95% CI, -0.21 to -0.01 mmol/L [-8.3 to -0.38 mg/dL]). Calculation of Keys scores demonstrated that substituting carbohydrates for dietary fats and cholesterol did not account for the majority of blood cholesterol reduction. Larger reductions were seen in trials in which subjects had initially higher blood cholesterol levels (greater than or equal to 5.9 mmol/L [greater than or equal to 229 mg/dL]), particularly when a dose of 3 g or more of soluble fiber was employed. This analysis supports the hypothesis that incorporating oat products into the diet causes a modest reduction in blood cholesterol level.


Adenohypophyseal activity in relation to suprarenal function in tuberculosis. This work was carried out on 150 subjects. They were classified into four groups: group I: Bronchogenic pulmonary T. B. (n = 96); group II: Haematogenous T. B. (n = 15); group III: Healed T. B. (n = 16), group IV: Healthy control (n = 23). Insulin tolerance test was done for each subject to assess the hypothalamo-hypophyseal axis. Glucose, ACTH, cortisol, GH, and PRL levels were estimated during fasting and over three hours after insulin administration. In group I and II the patients exhibited higher fasting levels of anti-insulin hormones and they respond greater than normals to insulin-induced hypoglycaemia. This might indicate early affection of the pituitary gland by TB infection, yet insulin-induced hypoglycaemia assured efficient function of the gland. In healed TB patients, no significant changes were obtained in the different hormonal behaviour, whether in the fasting state or after stimulation. This might be explained by improvement of the health condition of the patients, and relief of the stress induced by TB infection.


Prognostic significance of tumor deoxyribonucleic acid content in surgically resected small-cell carcinoma of lung. The prognostic role of deoxyribonucleic acid flow cytometry was investigated in 53 cases of surgically resected small-cell lung cancer. Deoxyribonucleic acid aneuploidy was detected in 26 patients (49.1%), the remaining tumors being either diploid or tetraploid. Patients with aneuploid tumors had a significantly reduced 2-year survival (38.5%) when compared with patients with diploid or tetraploid tumors (70.3%; p less than 0.05). This finding was independent of tumor stage on multiple logistic regression analysis. Diploid or tetraploid deoxyribonucleic acid content was associated with a particularly good 2-year survival (85%) in N0 or N1 disease. Tumor deoxyribonucleic acid ploidy should be taken into account in planning of management and assessment of prognosis in small-cell lung cancer.


The effects of the peripheral-type benzodiazepine acceptor ligands, Ro 5-4864 and PK 11195, on mitochondrial respiration. The role of the peripheral-type benzodiazepine acceptor is unclear. It has been suggested that the acceptor ligands, Ro 5-4864 and PK 11195, stimulate mitochondrial respiration by binding to the peripheral-type benzodiazepine acceptor. We determined the effect of the benzodiazepine Ro 5-4864 and of the isoquinoline carboxamide PK 11195 on the respiration rates of liver, kidney and adrenal mitochondria during coupled, uncoupled and phosphorylating respiration. These ligands inhibited uncoupled and phosphorylating respiration, but only at concentrations substantially greater than their KD values for binding to the acceptor. There was a slight stimulation of coupled respiration by these ligands at concentrations similar to their KD values for the acceptor, but this stimulation was markedly greater at higher concentrations. These results suggest that the ligands Ro 5-4864 and PK 11195 affect respiration in a non-specific way, independently of binding to the acceptor. There was no correlation between the effect of these ligands on respiration and the density of the acceptor in mitochondria from liver, kidney and adrenals. We suggest that the earlier reported alteration of respiration by these ligands was due to non-specific effects and was not mediated by the peripheral-type benzodiazepine acceptor.


Effect of tolbutamide and glyburide on pyruvate kinase flux in isolated rat hepatocytes. The effects of two representative sulfonylureas, tolbutamide and glyburide, on pyruvate kinase (PK) flux were examined in fasted rat hepatocytes. PK flux was estimated by trapping 14C from NaH14CO3 in a 2 mM lactate pool, accounting for any incomplete trapping by parallel incubations with L-[1-14C]alanine. Glyburide (20 microM) and tolbutamide (1 mM) decreased glucose formation by 34.9% and 54.8%, respectively, from 2 mM lactate. This decrease in glucose formation was associated with a proportional decrease in pyruvate carboxylase (PCOX) flux (32.7% and 50.5%, respectively). Under these conditions, no net change in PK flux was observed. When hepatocytes were preincubated with lactate and/or sulfonylurea addition for 30 min prior to radiolabeling with NaH14CO3, the metabolic state of the cells changed markedly. Glyburide produced a 34.6% decrease in glucose formation and a 31.3% decrease in PCOX flux, but no change in PK flux. In contrast, tolbutamide decreased glucose formation by 12.5% and increased PK flux by 53.2%, but no change in PCOX flux was observed. Such an increase in PK flux may be linked to tolbutamide-mediated increases in fructose-1,6-bisphosphate (F16P) via fructose-2,6-bisphosphate (F26P). These findings demonstrate that tolbutamide and glyburide decrease hepatic glucose production through various alterations in carbohydrate metabolism, depending upon the metabolic state of the cell. In addition, F26P may play a larger role in the hypoglycemic mechanism of action of tolbutamide than glyburide, since pyruvate carboxylase accounted for most of the decrease in glucose formation observed with glyburide and because preincubation with tolbutamide resulted in an activation of PK.


Agents that stimulate phosphoinositide turnover also elevate cAMP in SK-N-SH human neuroblastoma cells. Stimulation of m1 and of m3 muscarinic receptors has previously been shown to increase intracellular cAMP levels in a variety of cells. Although the mechanism underlying this response is not fully understood, it has been hypothesized to be secondary to the IP3-mediated rise in intracellular calcium. In order to determine whether other means of elevating intracellular calcium also raise cAMP levels, we stimulated SK-N-SH human neuroblastoma cells with bradykinin or with maitotoxin. Both of these agents stimulated phospholipase C, stimulated inositol phosphate release and elevated cAMP levels, thus demonstrating that this cAMP response is not unique to muscarinic receptor stimulation.


In vitro effects of insulin on aldosterone production in rat zona glomerulosa cells. Though long standing diabetes mellitus is frequently accompanied by hypoaldosteronism, the role of insulin in this setting has never been clearly established. In the present study we have examined the direct effects of insulin on aldosterone production in rat zona glomerulosa cells in vitro. Insulin is shown to directly stimulate aldosterone production in a dose dependent manner, and to attenuate angiotensin II mediated aldosterone production, without affecting angiotensin II receptor binding kinetics. Insulin had no effect on aldosterone production mediated by the other physiological stimuli (K+ and ACTH). These data suggest a possible interaction between insulin and angiotensin II in the regulation of aldosterone secretion.


Effect of experimentally-induced hypertension on angiotensin converting enzyme activity in the aortic endothelium and smooth muscle cum adventitia of the Sprague Dawley rat. The effect of experimentally-induced hypertension on the angiotensin converting enzyme (ACE) activity in the endothelium and smooth muscle cum adventitia of the Sprague Dawley rats was investigated. The ACE activity in both tissues of the 1-clip 2-kidney renovascular hypertensive rats and the deoxycorticosterone acetate/salt hypertensive rats were significantly higher than those of the normotensive control. These findings (i) support the suggestion that the 1-clip 2-kidney renovascular hypertensive rat represents a model of renin- and angiotensin-dependent hypertension and that the increased vascular ACE activity could play a role in the maintenance of hypertension (ii) provide new information regarding the association of increased vascular ACE activity and hypertension in the mineralocorticoid/salt treated hypertensive rats which may account for the finding by others that captopril is effective in preventing the development of hypertension in this low renin model of hypertension. On the other hand, the data also bring forth the possibility that the observed increase in vascular ACE activity could be the result of hypertension.


Human recombinant interferon alpha inhibits naloxone binding to rat brain membranes. Regulation of certain central nervous system (CNS) functions by the immune system may involve interferons (IFNs) acting through opioid receptors. Human recombinant interferon alpha (hrIFN alpha), as well as natural IFN alpha, have been reported to modulate a variety of physiological CNS functions both in vivo and in vitro. If the mechanism is via opioid receptors then IFN alpha should inhibit the binding of certain opioid radioligands to brain membranes. This study reports the inhibitory effect of hrIFN alpha on the binding of 3H-naloxone to rat brain membranes in vitro. The inhibitory effect at 37 degrees C is hrIFN alpha concentration dependent over the range of 500 to 6000 antiviral units per ml (U/ml) with 500 micrograms of membrane protein. The presence of NaCl (100mM) increases specific binding of naloxone and attenuates the inhibitory effect of hrIFN alpha. The inhibitory effect of hrIFN alpha is sensitive to temperature with maximum inhibition observed at 37 degrees C, and less as incubation temperature is reduced. These data suggest that IFN alpha may modulate certain physiologic functions via opioid pathways in the brain.


Atrial natriuretic factor inhibits the CRH-stimulated secretion of ACTH and cortisol in man. Corticotrophic secretion of ACTH is stimulated by corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP), and suppressed by glucocorticoids. In vitro and preclinical studies suggest that atrial natriuretic factor (ANF) may be a peptidergic inhibitor of pituitary-adrenocortical activity. The aim of this study was to elucidate a possible role of ANF as a modulator of ACTH release in humans. A bolus injection of 100 micrograms human CRH (hCRH) during a 30 min intravenous infusion of 5 micrograms/min human alpha atrial natriuretic factor (h alpha ANF) was administered at 19:00 to six healthy male volunteers. In comparison to saline, a blunted CRH-stimulated secretion of ACTH (mean maximum plasma level +/- SD 45 min after hCRH: saline 46.2 +/- 14.2 pg/ml, h alpha ANF 34.6 +/- 13.8 pg/ml, p-value = 0.007) and a delayed rise (10 min) in cortisol were detected. The maximum plasma cortisol levels remained nearly unchanged between saline and h alpha ANF administration (mean maximum plasma level +/- SD 60 min after hCRH: saline 182 +/- 26 ng/ml, h alpha ANF 166 +/- 54 ng/ml). No effects of h alpha ANF on basal cortisol levels were observed; in contrast, basal ACTH plasma levels were slightly reduced. Basal blood pressure and heart rate remained unaffected. In the control experiment, infusion of 3 IU AVP in the same experimental paradigm increased basal and stimulated ACTH and cortisol levels significantly in comparison to saline. These observations suggest that intravenously administered haANF inhibits the CRH-stimulated release of ACTH in man.


The role of oxygen free radicals in the development of chronic renal failure. This study examined whether there is increased production of oxygen free radicals during chronic renal failure. Rats subjected to 3/4 nephrectomy and sham operated controls were killed after 3 weeks. Lipid extracts of plasma and renal tissue were examined by HPLC and kidney specimens were also analyzed by EPR spectroscopy. The redox capacity of blood was assessed using nitroblue tetrazolium and plasma ascorbate levels were measured with HPLC. There was no detectable renal production of oxygen free radicals in rats with chronic renal failure. Kidney parenchymal content of other oxidants and the oxidant:reductant ratio were similar in control and uremic animals. The plasma redox capacity and ascorbate levels were elevated in uremic rats. We conclude that early in the course of chronic renal failure, there is not excessive production of oxygen free radicals. There is accumulation of reductants, primarily ascorbate, in the plasma of uremic animals.


Correlation of expression of H/Le(y)/Le(b) antigens with survival in patients with carcinoma of the lung. The level of expression of H/Le(y)/Le(b) antigens is high in various histologic types of lung cancer, a feature that may be related to deletion of A and B blood-group antigens. We evaluated the possibility that expression of this antigen, which can be defined by the monoclonal antibody MIA-15-5, might be of prognostic value, as suggested by our previous observation that MIA-15-5 inhibits tumor-cell motility and metastasis. We used MIA-15-5 to stain tissue sections from 149 patients with primary lung cancer whose clinico-pathological histories were well documented. The survival curves for patients whose tumors stained positively were compared with the curves for those whose tumors stained negatively. Multivariate analyses were performed with a Cox proportional-hazards regression model. Among the 149 patients studied, five-year survival in the 91 patients with MIA-positive tumors was significantly lower than survival in the 58 with MIA-negative tumors (20.9 percent vs. 58.6 percent, P less than 0.001). Among the 67 patients with squamous-cell carcinoma, the rates also differed significantly (10.5 percent vs. 62.1 percent, P less than 0.001). The difference in survival between patients with MIA-positive tumors and those with MIA-negative tumors was significant among patients with blood groups A and AB (P less than 0.001), but not among those with blood group B or O (P = 0.071 and 0.068, respectively). Multivariate analysis with the Cox regression model indicated that positivity best correlated with five-year mortality, followed by lymph-node status (N stage) and tumor size status (T stage), whereas sex, age, and blood group did not correlate with mortality. Positivity for MIA (i.e., immunohistologic staining by MIA-15-5, which defines H/Le(y)/Le(b) antigens) is inversely correlated with survival among patients with primary lung cancer and may be of prognostic value.


[Influence of phosphorylation on the functional properties of the sodium channel reconstructed in an artificial membrane]. Phosphorylation of the reconstructed TTX-sensitive cytosolic protein of the bovine brain has been studied. Some properties of the protein are similar to those of the membrane potential-dependent sodium channel. It is shown that the influence of phosphorylation by protein kinase A on the reconstructed channel greatly depends on the mode of reconstruction. Phosphorylation fo reconstructed channels in the open state leads to their closing. Preliminary phosphorylation of channel-forming protein results in a considerable increase of the activation effect of veratrine and scorpion toxin.


[T-cell receptor repertoire in tumor infiltrating lymphocytes within malignant brain tumors]. Expression of T cell receptor (TCR) V alpha and V beta genes in tumor infiltrating lymphocytes (TILs) within human malignant brain tumor was examined. Primers for 18 different human TCR V alpha and 21 V beta families were used to analyze TCRV-(D)-J-C gene rearrangements in TILs in 8 human malignant glioma specimens obtained at surgery. Using the polymerase chain reaction (PCR) method, we detected limited TCR variable region, V alpha gene expression in malignant glial tumors and also V alpha 7 and V alpha 12 TCR genes were preferentially expressed. Usage of TCR V beta gene was not as restricted as in TCR V alpha. These TILs expressing a limited repertoire of TCRs might be isolated, expanded, and used therapeutically for treatment of malignant brain tumors.


A macro cell-attached patch-clamp study of the properties of the Na current in the vicinity of the motor endplate region of frog single interosseal skeletal muscle fibres. A macro cell-attached patch-clamp technique using large (16 microns) electrodes was developed to study the properties of the Na current (INa) in the motor endplate region of frog interosseal muscle fibres (resting potential approx.-99 mV). The fibre isolation procedure allows the formation of gigaOhm seals and thus a good voltage-clamp control of the patch. At 22 degrees C, in the presence of 110 mM external [Na] and of K channel blockers, INa activates at -49.6 +/- 1.9 mV, reaches a maximum of 4.33 +/- 0.66 mA/cm2 at -7.5 +/- 2.5 mV and reverses at Vrev equal to +63.2 +/- 1.9 mV. There is no evidence for the presence of a tubular INa. When the [Na] in the recording pipette is changed, Vrev exactly follows the Nernst equation for Na ions. An internal [Na] of 9.69 mM is determined. The Na conductance is maximum (63.56 +/- 7.03 mS/cm2) at +8.9 +/- 3.0 mV and markedly decreases for potentials positive to +25 mV. In contrast, the Na permeability (maximum of 6.13 +/- 0.95 x 10(-4) cm/s at +51.4 +/- 5.6 mV) remains more constant at positive potentials. The Na channels are half-inactivated at -68.9 mV and half-activated at -37.9 mV. At the potential at which INa is maximum, the half-time of activation is 223.9 +/- 10.5 microseconds, the time to peak 365.7 +/- 13.5 microseconds and the time constant of inactivation 260.7 +/- 11.2 microseconds. The time constant of reactivation at -100 mV is 1.44 +/- 0.19 ms. These and other results show that INa can be adequately studied with this technique.


Poneratoxin, a new toxin from an ant venom, reveals an interconversion between two gating modes of the Na channels in frog skeletal muscle fibres. The effects of synthetic poneratoxin (PoTX), a new toxin isolated from the venom of the ant Paraponera clavata, were studied under current- and voltage-clamp conditions in frog skeletal muscle fibres. PoTX induces a concentration-dependent (10(-9) M-5 x 10(-6) M) prolongation of the action potentials and, at saturating concentration, a slow repetitive activity developing at negative potentials. PoTX specifically acts on voltage-dependent Na channels by decreasing the peak Na current (INa) and by simultaneously inducing a slow INa which starts to activate at -85 mV and inactivates very slowly. Both the fast and the slow components of INa are suppressed by tetrodotoxin and reverse at the same potential corresponding to the equilibrium potential for Na ions. The fast component of INa has voltage dependence, activation and steady-state inactivation almost similar to those of the control INa. The voltage dependence of the slow Na conductance is 40 mV more negative than that of the fast one. The results suggest that PoTX affects all the Na channels and that the fast and the slow INa components originate from a possible PoTX-induced interconversion between a fast and a slow operating mode of the Na channels.


Giga-seal formation alters properties of sodium channels of human myoballs. The influence of giga-seal formation on the properties of the Na+ channels within the covered membrane patch was investigated with a whole-cell pipette and a patch pipette applied to the same cell. Current kinetics, current/voltage relation and channel densities were determined in three combinations: (i) voltage-clamping and current recording with the whole-cell pipette, (ii) voltage-clamping with the whole-cell pipette and current recording with the patch pipette and, (iii) voltage-clamping and current recording with the patch pipette. The Hodgkin-Huxley (1952) parameters tau m and tau h were smaller for the patch currents than for the whole cell, and the h infinity curve was shifted in the negative direction. The channel density was of the order of 10 times smaller. All effects were independent of the extracellular Ca2+ concentration. The capacitive current generated in the patch by the whole-cell Na+ current and its effect on the transmembrane voltage of the patch were evaluated. The kinetic parameters of the Na+ channels in the patch did not depend on whether the voltage was clamped with the whole-cell pipette or the patch pipette. Thus, the results are not due to spurious voltage.


Protein kinase C activation causes inhibition of Na/K-ATPase activity in Madin-Darby canine kidney epithelial (MDCK) cells. To evaluate the influence of protein kinase C (PKC) activation on Na/K-ATPase activity in MDCK cells, we studied the effect of phorbol myristate acetate (PMA) and two diacylglycerol analogues, oleoylacetylglycerol and dioctanoylglycerol, on the enzyme activity. Na/K-ATPase activity was determined by cytochemistry. PMA induced a time- and dose-dependent inhibition of Na/K-ATPase activity and at 100 ng/ml decreased the enzyme activity by 55% of the initial value. These effects were mimicked by oleoylacetylglycerol and dioctanoylglycerol, and were abolished by two inhibitors of PKC, 1-(5-isoquinolinylsulphonyl)-2-methylpiperazine (H7) and sphingosine. A phorbol ester that does not activate PKC, 4 alpha-phorbol 12,13-didecanoate, did not inhibit Na/K-ATPase activity. PMA inhibition persisted in the presence of cycloheximide and actinomycin D but not in the presence of amiloride. Dopamine (10 microM) inhibition of Na/K-ATPase activity was abolished in a dose-dependent manner by sphingosine. Results suggest that in MDCK cells Na/K-ATPase is an effector protein for PKC and that dopamine inhibition of its activity may be mediated by PKC.


Characterization of basolateral Na/H exchange (Na/H-1) in MDCK cells. MDCK cells were grown to confluent monolayers on permeant filter supports; pH was analysed by using the pH-sensitive fluorescent probe 2'7'-biscarboxyethyl-5,6-carboxyfluorescein and a routine spectrofluorometer equipped with a perfusion cuvette [Krayer-Pawlowska et al. (1990) J Membr Biol 120:173-183]. Superfusion of the basolateral (but not apical) cell surface with Na(+)-containing solutions led to immediate recovery of pHi from an acid load (NH4 prepulse). This pHi recovery was reversibly inhibited by ethylisopropylamiloride indicating Na/H exchange activity. Na/H exchange activity showed an apparent Km for Na+ of about 25 nM Na+ and an apparent Ki for inhibition by dimethylamiloride of around 0.2 microM; inhibition by dimethylamiloride was competitive with Na+ interaction. Lowering pHi prior to analysis of Na/H exchange leads to sharp activation of Na/H exchange; the apparent Vmax for Na/H exchange is increased more than tenfold by lowering the pHi from 7.0 to 6.7 without an effect on apparent Km values for Na+ interaction. It is concluded that MDCK cells (strain I) grown on a permeant support contain only basolateral Na/H exchange activity, most likely Na/H-1 [for nomenclature see Igarashi et al. (1991) Kidney Int 40:S84-S89].


Polarized expression of Na+/H+ exchange activity in LLC-PK1/PKE20 cells: II. Hormonal regulation. LLC-PK1/PKE20 cells (a continuous epithelial cell line) has two different Na/H exchange activities: Na/H-1 located in the basolateral membrane and Na/H-2 located in the apical membrane [Casavola et al. (1989) Biochem Biophys Res Commun 165:833-837; Haggerty et al. (1988) Proc Natl Acad Sci USA 86:6797-6801]. In the present report we have studied hormone regulation of these exchange activities by measuring Na-dependent recovery of pHi from an acid load (by using microspectrofluorometry and 2,7-bis(carboxyethyl)-5,6-carboxyfluorescein) in response to activation of regulatory cascades by either pharmacological agents or by vasopressin or calcitonin. Agents leading to activation of protein kinase A (cAMP-dependent), such as forskolin (10 microM), 8-Br-cAMP (0.25 mM), and isobutylmethylxanthine (0.5 mM), inhibited Na/H-2 and Na/H-1 by an average of 49%. Stimulation of protein kinase C by a phorbol ester (phorbol 12-myristate 13-acetate, TPA, 100 nM) inhibited Na/H-2 (by an average of 48%) and stimulated Na/H-1 (by an average of 38%); these effects of TPA were also observed in the presence of forskolin (100 microM). Addition of either vasopressin (2 microM) or calcitonin (0.3 microM) onto both sides of the monolayer decreased the activity of Na/H-2 by an average of 26.3% and 27.7% respectively, and stimulated the activity of Na/H-1 by an average of 17.4% and 38.7% respectively; exposure of cells to either hormone stimulated production of cAMP and inositol trisphosphate, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)


An analysis of Na+ currents in rat olfactory receptor neurons. Na+ currents were observed in acutely-dissociated adult rat olfactory receptor neurons using the whole-cell recording techniques. The threshold for current activation was near -70 mV and currents were fully activated by -10 mV (midpoint: -45 mV). Steady-state inactivation was complete at potentials more positive than -70 mV and half complete at -110 mV (+/- less than 1, n = 8). Complete recovery from inactivation required one second at -100 mV (n = 7). The addition of 10 microM tetrodotoxin or 1 mM Zn2+ to the external solution was required to completely block the current. The current differs from those in amphibian and cultured neonatal rat olfactory neurons in its unusually negative voltage-dependence and slow recovery. Since mammalian olfactory neurons have very high input resistances, physiological resting potentials cannot usually be measured using whole-cell recording techniques. However, predominantly-capacitatively-coupled spikes activated by depolarisation were frequently observed in cell-attached patches. This indicates that the cells were excitable and implies that they must have had resting potentials more negative than -90 mV in order for this current to underlie the action potential.


Beta-subunit expression is required for cAMP-dependent increase of cloned cardiac and vascular calcium channel currents. In contrast to vascular smooth muscle (VSM), cAMP-dependent phosphorylation increases L-type voltage dependent Ca(2+)-channel (L-VDCC) activity in heart. To investigate whether this difference depends on the tissue-specific alpha 1-subunit of the L-VDCC or its regulation by other subunits, we used a Xenopus laevis oocyte expression system. Injection of cAMP into oocytes expressing cardiac alpha 1 or VSM alpha 1 alone had no effect on L-VDCC activity. However, cAMP increased L-VDCC activity 2-fold in oocytes co-expressing cardiac alpha 1 or VSM alpha 1 with the skeletal muscle beta-subunit. These results suggest that the presence of the beta-subunit is required for cAMP-mediated increase of L-VDCC activity and that the characteristics of tissue-specific beta-subunits may explain differential regulation of L-VDCC activity.


Solid-phase synthesis of an RNA nucleopeptide fragment from the nucleoprotein of poliovirus. The naturally occurring RNA-nucleopeptide H-Ala-Tyr[5'-pUUAAAAC-3']-NH2 is prepared via a solid-phase phosphite triester approach using N-SiOMB/O-TBDMS-protected nucleosides. Preliminary 1H-NMR studies show that the peptidyl unit has a remarkable effect on the conformational behaviour of the RNA moiety in the nucleopeptide.


Purification and characterization of TnsC, a Tn7 transposition protein that binds ATP and DNA. The bacterial transposon Tn7 encodes five transposition genes tnsABCDE. We report a simple and rapid procedure for the purification of TnsC protein. We show that purified TnsC is active in and required for Tn7 transposition in a cell-free recombination system. This finding demonstrates that TnsC participates directly in Tn7 transposition and explains the requirement for tnsC function in Tn7 transposition. We have found that TnsC binds adenine nucleotides and is thus a likely site of action of the essential ATP cofactor in Tn7 transposition. We also report that TnsC binds non-specifically to DNA in the presence of ATP or the generally non-hydrolyzable analogues AMP-PNP and ATP-gamma-S, and that TnsC displays little affinity for DNA in the presence of ADP. We speculate that TnsC plays a central role in the selection of target DNA during Tn7 transposition.


[Endothelin, a peptidic vasoconstrictor]. Endothelin is a 21 aminoacids peptide belonging to the family of endothelium-derived contracting factors. It exists as 3 isoforms which have similar actions. It is principally, but not exclusively, synthesized and secreted by the vascular endothelial cells. Hypoxia, physical stretching and various endogenous substances stimulate its secretion. Its specific receptors are widespread in tissues, and the endothelin-receptor binding process produces a rise of intracellular calcium through the formation of inositol phosphate. Endothelin is the most potent of known vasoconstrictor substances. In addition, it acts on the myocardium and has a contracturant effect on other smooth muscle fibres. It also contributes to the release of endogenous peptides, inhibits platelet aggregation and has mitogenic properties. Endothelin can be determined in biological fluids, such as plasma, urine and cerebrospinal fluid, using immunoanalysis methods. Several pathological situations are associated with an increase of plasma endothelin concentrations; these situations include arterial hypertension, myocardial infarction, cardiogenic shock and renal failure. Although not all physiopathological applications of endothelin have been elucidated, our current knowledge of this substance indicates that it will be of importance in human medicine.


[Coronary pathology after heart transplantation]. Graft coronary disease is a frequent and devastating complication with rapid development after heart transplantation. Until now, non-invasive and invasive methods have proved to be insensitive in the prediction and detection of the early stages of this disease. Conventional arteriography is considered as the only reliable means of diagnosis, but it remains insensitive in the accurate evaluation of the severity of graft coronary lesions (obliterative, diffuse and distal lesions). Precise quantitation of coronary lumen changes may be a sensitive method for the accurate evaluation of graft coronary disease and help in the understanding of the natural course of development of this disease. The pathogenesis of the disease is still unclear. It is possible that graft coronary disease is a consequence of non-treated low-grade cellular rejections. In most cases, retransplantation must be considered as the unique solution.


[The individual characteristics of the postradiation reaction of the cyclic nucleotides in rat thymocytes]. It was shown that X-irradiation of rats (4.3 Gy), which were preliminarily divided into two groups by the neutrophilic reaction in the peripheral blood to the effect of a three-hour immobilization, induced different reactions of the cyclic nucleotide system. Thus, in animals hyper-reactive to stress radiation injury to the above system was severe: relative reactivity made 22.8% of the initial value, and adenylate cyclase ability to respond to a hormonal stimulus was drastically inhibited. In hyporeactive animals, relative reactivity of adenylate cyclase system after irradiation made 47% throughout the same period of observation; inhibition of adenylate cyclase activity was also less pronounced.


[Effects of transcutaneous nerve stimulation on the plasma and CSF concentrations of beta-endorphin and the plasma concentrations of ACTH, cortisol and prolactin in hysterectomized women with postoperative pain]. Plasmatic and cerebrospinal fluid levels of beta-endorphin and plasmatic concentration of ACTH, cortisol, and prolactin were investigated in 10 healthy volunteers free of pain and in a group of 38 patients who presented moderate or intense postoperative pain. The analgesic technique was transcutaneous neural stimulation. In 28 patients the stimulation was delivered at 40-80 Hz (high frequency) whereas in the remaining 10 patients it was administered in a placebo form. Measurements of hormone concentrations were performed using radioimmunoassay techniques. In patients free of pain hormone analysis was done at once, whereas in patients with pain this analysis was performed before and one hour after transcutaneous neural stimulation. We compared data obtained in control subjects with data collected in patients before and one hour after high frequency and placebo transcutaneous neural stimulation. Levels of beta-endorphin were comparable in patients with and without pain. However, ACTH, cortisol, and prolactin were increased in patients with pain. High frequency stimulation induced greater beta-endorphin levels than placebo neural stimulation and slightly lower concentration of prolactin. There were no significant differences in ACTH and cortisol levels.


In vivo gene transfer with retroviral vector-producer cells for treatment of experimental brain tumors. Direct in situ introduction of exogenous genes into proliferating tumors could provide an effective therapeutic approach for treatment of localized tumors. Rats with a cerebral glioma were given an intratumoral stereotaxic injection of murine fibroblasts that were producing a retroviral vector in which the herpes simplex thymidine kinase (HS-tk) gene had been inserted. After 5 days during which the HS-tk retroviral vectors that were produced in situ transduced the neighboring proliferating glioma cells, the rats were treated with the anti-herpes drug ganciclovir. Gliomas in the ganciclovir- and vector-treated rats regressed completely both macroscopically and microscopically. This technique exploits what was previously considered to be a disadvantage of retroviral vectors--that is, their inability to transfer genes into nondividing cells. Instead, this feature of retroviruses is used to target gene delivery to dividing tumor cells and to spare nondividing neural tissue.


Calcium entry through kainate receptors and resulting potassium-channel blockade in Bergmann glial cells. Glutamate receptors, the most abundant excitatory transmitter receptors in the brain, are not restricted to neurons; they have also been detected on glial cells. Bergmann glial cells in mouse cerebellar slices revealed a kainate-type glutamate receptor with a sigmoid current-to-voltage relation, as demonstrated with the patch-clamp technique. Calcium was imaged with fura-2, and a kainate-induced increase in intracellular calcium concentration was observed, which was blocked by the non-N-methyl-D-aspartate (NMDA) glutamate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and by low concentrations of external calcium, indicating that there was an influx of calcium through the kainate receptor itself. The entry of calcium led to a marked reduction in the resting (passive) potassium conductance of the cell. Purkinje cells, which have glutamatergic synapses, are closely associated with Bergmann glial cells and therefore may provide a functionally important stimulus.


Calcium-permeable AMPA-kainate receptors in fusiform cerebellar glial cells. Glutamate-operated ion channels (GluR channels) of the L-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-kainate subtype are found in both neurons and glial cells of the central nervous system. These channels are assembled from the GluR-A, -B, -C, and -D subunits; channels containing a GluR-B subunit show an outwardly rectifying current-voltage relation and low calcium permeability, whereas channels lacking the GluR-B subunit are characterized by a doubly rectifying current-voltage relation and high calcium permeability. Most cell types in the central nervous system coexpress several subunits, including GluR-B. However, Bergmann glia in rat cerebellum do not express GluR-B subunit genes. In a subset of cultured cerebellar glial cells, likely derived from Bergmann glial cells. GluR channels exhibit doubly rectifying current-voltage relations and high calcium permeability, whereas GluR channels of cerebellar neurons have low calcium permeability. Thus, differential expression of the GluR-B subunit gene in neurons and glia is one mechanism by which functional properties of native GluR channels are regulated.


Hebbian depression of isolated neuromuscular synapses in vitro. Modulation of synaptic efficacy may depend on the temporal correlation between pre- and postsynaptic activities. At isolated neuromuscular synapses in culture, repetitive postsynaptic application of acetylcholine pulses alone or in the presence of asynchronous presynaptic activity resulted in immediate and persistent synaptic depression, whereas synchronous pre- and postsynaptic coactivation had no effect. This synaptic depression was a result of a reduction of evoked transmitter release, but induction of the depression requires a rise in postsynaptic cytosolic calcium concentration. Thus, Hebbian modulation operates at isolated peripheral synapses in vitro, and transsynaptic retrograde interaction appears to be an underlying mechanism.


[Effect of endothelin on isolated myocytes from rat heart]. The mechanism of endothelin (ET) action on isolated myocytes of rat heart was investigated. Administration of 10(-9)-10(-7) mol/L ET caused dose-dependently severe contracture of myocytes, increase in cytosolic lactate dehydrogenase leakage and increase of cellular total calcium. ET also enhanced 45Ca2+ influx in myocytes, that could be antagonized by calcium channel blocker verapamil. Incubation of Fura-2 -preloaded myocytes with ET would induce a significant increase of cytosolic free Ca2+, and this effect of ET could also be partly antagonized by verapamil. These results suggest that ET enhances Ca2+ influx in myocytes mainly through voltage-dependent calcium channel, by which ET exerts its biological action.


[Relationship between the changes in beta-adrenoceptor content and the metabolism of phospholipids in lung tissue from acute heat stressed rats]. To explore the relationship between the change of beta-adrenoceptor and the metabolism of phospholipids in lung tissue from acute heat stressed rats, the Bmax of beta-adrenoceptors, the activity of phospholipase A2 (PLA2), the content of phosphatidylcholine (PC) and phosphatidylserine (PS), and membrane fluidity in lung tissue of normal and heat stressed rats were investigated. The relevant parameter values mentioned above were 479 +/- 94 fmol/mg protein, 78.5 +/- 8.2 U, 53.5 +/- 1.7 mg/g.wet. w. and 425.1 +/- 68.1 micrograms/g.wet. w. respectively. Whereas in the heat stressed rats with rectal temperature raised to 42 degrees C for 15 min, the Bmax of beta-adrenoceptor was decreased by 43% (P less than 0.01), the activity of PLA2 increased by 83% (P less than 0.01), the contents of PC and PS decreased by 50% and 47% (P less than 0.01) respectively. A lower membrane fluidity in lung tissue for heat stressed rats was also demonstrated. The results suggest that the decreased binding sites of beta-adrenoceptor in lung tissue of rat during hyperthermia may be contributed to the activation of PLA2, which then accelerated the catabolism of phospholipids such as PC and PS in the cell plasma membrane, with a consequent alteration of membrane fluidity.


[Effect of intracerebroventricular injections of ANG II and ANG II antibody on renal sodium excretion and Na+.K(+)-ATPase in rat]. In anesthetized rats, it was observed that intracerebroventricular (I.C.V.) microinjection of angiotensin II (ANG II) in a dose of 16 pg evoked a significant increase in renal sodium excretion which began within 15 min and lasted for 90 min. The activity of Na+.K(+)-ATPase in renal cortex after I.C.V. microinjection of ANG II (1.51 +/- 0.26 mumol Pi/mg Pro.h) was inhibited as compared with that of the control injecting of artificial cerebrospinal fluid (2.66 +/- 0.28 mumol Pi/mg Pro.h, P less than 0.01). There was no change in mean arterial pressure. Within 15 min after I.C.V. administration of ANG II antibody, however, and antinatriuretic period of 135 min and a higher activity of Na+.K(+)-ATPase in renal cortex (3.61 +/- 0.34 mumol Pi/mg Pro.h, P less than 0.05 compared with control) were observed. There was no natriuresis in the animals microinjected with ANG II either into femoral vein or into spinal subarachnoid space. The result of the present investigation suggests that brain endogenous ANG II may possess some natriuretic activity possibly through inhibiting renal Na+.K(+)-ATPase activity.


Carcinoma of the body and tail of the pancreas: is curative resection justified? The role of resection in the treatment of carcinoma of the distal pancreas remains unclear. The less frequent occurrence of tumor in the distal gland, advanced tumor stage at diagnosis, and a lack of reported success have combined to produce therapeutic nihilism in the minds of many surgeons. The goal of this review was to assess long-term survival after distal pancreatectomy for carcinoma of the pancreas. The records of all patients undergoing distal pancreatectomy at the Mayo Clinic for a primary pancreatic malignant tumor during the 25-year period from 1963 to 1987 were reviewed. Forty-four patients undergoing potentially curative distal pancreatectomies were identified: 26 patients for ductal adenocarcinoma, 12 patients for islet cell carcinoma, and six patients for cystadenocarcinoma. Major postoperative morbidity occurred in 9% of the patients and operative death in 2% of the patients. Patients with ductal adenocarcinoma frequently were admitted with advanced disease (stage II or III). The median overall survival for patients with ductal adenocarcinoma was 10 months. Fifteen percent of the patients survived 2 years after operation, and 8% of the patients survived 5 years. In contrast, the 5-year survival after resection of islet cell carcinomas and cystadenocarcinomas was excellent (83% and 100%, respectively). The prognosis for patients with ductal adenocarcinoma in the distal pancreas who were treated with potentially curative distal pancreatectomy is poor; however, the results are not substantially different from those reported after pancreaticoduodenectomy for malignant tumors of the proximal pancreas. Some patients with adenocarcinoma of the distal pancreas who were treated with resection may be long-term survivors. We recommend resection of carcinoma of the distal pancreas when the disease is limited to the gland and believe that all patients with ductal adenocarcinoma should be considered for postoperative adjuvant radiation and chemotherapy.


Day-5 protocol liver allograft biopsies document early rejection episodes and are predictive of recurrent rejection. The day-5 posttransplant protocol biopsy specimens and clinical courses of 27 consecutive orthotopic liver transplant recipients followed up at least 6 months were reviewed. Twelve (44%) of 27 patients had histologic evidence of rejection on the day-5 biopsy; 8 (67%) of these 12 patients required OKT3 for reversal of the rejection. No significant differences in biochemical liver test results, bile output, or cyclosporine levels were observed between this group and the 15 patients (56%) without histologic evidence of rejection on day 5. Eight (67%) of the 12 patients with rejection had recurrent rejection episodes, with one recurrence each in six patients, two recurrences in one patient, and three recurrences in one patient. Of the 15 patients without rejection on day 5, nine (60%) subsequently had rejection at 10 days, 14 days, and 1 1/2, 3 1/2, 4, 5, and 11 months after transplantation. Only one (11%) of these nine patients had a recurrent rejection episode. There were no differences in the incidence of posttransplant cytomegalovirus infections between the two groups. Two cases of posttransplant lymphoma were seen; they developed in two patients without rejection on the day-5 biopsy. No patients or allografts were lost to acute or chronic rejection. No complications occurred as a result of the day-5 protocol biopsy. The day-5 protocol biopsy is useful in detecting rejection episodes that may not otherwise be clinically apparent.


[Over-the-counter weight-reducing preparations]. This report deals with over-the-counter products sold currently in Denmark for weight reduction. Only oral products (alternative medications and food supplements) are included. The report includes 35 such products. The aims of the report are to provide a common, factual basis for the debate about weight-reduction products and to present proposals for regulations that improve the conditions for patients and health professionals to make their choice of the optimal products. Current laws and administrative regulations are found to be complicated, obscure and inadequate. For most products, documentation for efficacy and safety is inadequate and health hazards are probable using several of the products. It is recommended 1) that obesity should be considered as a disease also in a legal/administrative context, 2) that an effective and objective registration of side-effects to alternative medication and food supplements is established, 3) that these products are tested for efficacy and safety before being marketed, 4) that the entire product information is made easily accessible, 5) that products without any documented effect are clearly labelled with this information and 6) that weight loss products involving health hazards are excluded from the market.


Chemodissolution of urinary uric acid stones by alkali therapy. Experience with chemodissolution of uric acid stones in 30 patients is presented. Chemodissolution was achieved either with infusion of 0.16 M i.v. lactate or oral sodium bicarbonate, in addition to liberal fluid intake and allopurinol wherever indicated. In some cases direct chemodissolution by in situ irrigation with sodium bicarbonate solution was done after an initial percutaneous nephrostomy. Seven patients presented with acute obstructive anuria. In this group, 5 of them had bilateral obstructive calculi, while 2 had unilateral obstruction in a solitary kidney. The latter 2 had complete recovery following intravenous lactate therapy. Of the 5 presenting with bilateral obstruction, 2 patients had complete response to chemodissolution, whereas the remaining 3 had only a partial response requiring surgery for ultimate salvage. In this group I, 6 patients are doing well with a normal serum creatinine at 3 months to 4 years follow-up, while 1 patient has a serum creatinine, stabilised at 3.2 mg%. In the second group, 23 patients presented with non-obstructing urinary stones. Flank pain was the commonest complaint and a concomitant history of gout was present in 6 patients. Hyperuricaemia was detected in 12 and hyperuricosuria in 19. All cases were managed by high fluid intake and oral sodium bicarbonate, with self-monitoring of urine pH, which was kept between 6.5 and 7.0. Allopurinol was administered in cases having hyperuricaemia and/or hyperuricosuria. Systemic alkali therapy in the form of intravenous molar lactate or sodium bicarbonate is effective and safe both in obstructive anuria and non-obstructive urinary uric acid stones.


Primary small cell carcinoma of the urinary bladder. Report of a case with immunohistochemical analyses. A case of primary small cell carcinoma of the urinary bladder is reported. The light-microscopic diagnosis was supported by immunoreactivity for HISL-19 (marker for peptide-hormone-producing cells) and for neuron-specific enolase (NSE), demonstrating the neuroendocrine differentiation of this rare bladder tumor. Serum NSE, which was significantly elevated, can be a marker for disease extent and response to therapy.


Comparative efficacy of three doses of the genetically engineered Aujeszky's disease virus vaccine strain 783 in pigs with maternal antibodies. Pigs with low levels of maternally derived antibodies were vaccinated twice intramuscularly with 10(5), 10(5.5), or 10(6) plaque forming units (p.f.u.) of the genetically engineered Aujeszky's disease virus (ADV) vaccine strain 783. Strain 783 has deletions in genes encoding glycoprotein gI and thymidine kinase. All vaccinated pigs showed a high level of protection against clinical disease after challenge infection with virulent ADV. Vaccination also reduced virus excretion. The daily mean virus excretion and the mean number of days with virus excretion, fever, mild clinical signs, and growth retardation were higher in pigs vaccinated with 10(5) than in pigs vaccinated with 10(5.5) or 10(6) p.f.u. of strain 783.


Avian retroviral recombinant expressing foreign envelope delays tumour formation of ASV-A-induced sarcoma. An avian recombinant retrovirus expressing subgroup A envelope glycoprotein antigenicity, RAV-0-A1, significantly delayed sarcoma induction in chickens after challenge with ASV-A. When tumours were formed, significantly smaller tumours resulted. The mechanism of protection does not appear to be interference mediated, since virus was not detected in the chickens. Protection was correlated with both neutralizing and complement-dependent cytotoxic antibodies (CDCA).


Comparative analysis of the immunostimulatory properties of different adjuvants on the immunogenicity of a prototype parainfluenza virus type 3 subunit vaccine. The immunogenicity of a parainfluenza virus type 3 (PIV-3) subunit vaccine consisting of affinity-purified haemagglutinin-neuraminidase (HN) and fusion (F) surface glycoproteins was tested in guinea-pigs and hamsters. The ability of several different immunopotentiating agents to enhance the antibody response of animals to the PIV-3 surface glycoproteins was evaluated. The immunity induced by HN and F alone was compared with the response elicited by purified proteins combined with Freund's complete adjuvant, aluminium phosphate, Syntex's threonyl-muramyl dipeptide (MDP) SAF-MF formulation, or Ribi's adjuvant formulation containing BCG cell wall skeleton (CWS), trehalose dimycolate (TDM) and monophosphoryl lipid A (MPL) in a 2% squalene-in-water emulsion. Purified proteins were also incorporated into three different liposome formulations prepared by the detergent dialysis procedure. Immunization of guinea-pigs and hamsters with two 15 micrograms doses of the PIV-3 surface glycoproteins administered in the absence of adjuvant elicited high haemagglutination inhibition, neutralization and anti-fusion titres. The liposome preparations failed to enhance the antibody titres. Ribi's adjuvant formulation was effective at inducing a good secondary response to the purified proteins while the immunostimulatory effects of aluminium phosphate, Syntex and Freund's adjuvants were clearly demonstrated in both primary and secondary responses. When administered without adjuvant, a 15 microgram dose of the HN and F mixture was capable of protecting hamsters against live virus challenge. The immunoprotective dose of the purified proteins could be reduced to at least 0.1 microgram by the addition of aluminium phosphate, Syntex or Freund's adjuvants.


Inhibitory effect of rhynchophylline on platelet aggregation and thrombosis. Rhynchophylline (Rhy) inhibited rabbit platelet aggregation induced by arachidonic acid (AA), collagen, and ADP. The values of IC50 were 0.72, 0.74, and 0.67 mmol.L-1, respectively. Rhy reduced the thromboxane B2 (TXB2) generation in PRP induced by collagen but failed to reduce that induced by AA. Rhy suppressed malondialdehyde (MDA) formation in platelet suspension stimulated by thrombin, inhibited the platelet factor 4 (PF4) release. It did not alter intraplatelet cAMP concentration. Rhy 10-20 mg.kg-1 iv showed a significant inhibition of venous thrombosis and cerebral thrombosis in rats.


Effect of dimethyl sulfoxide on cytosolic calcium in cultured rat hepatocytes injured by D-galactosamine. D-galactosamine (Gal 0.5 mmol.L-1) made lactate dehydrogenase (LDH) leakage from the hepatocytes in monolayer-culture increase by 50%, Dimethyl sulfoxide (Me2SO 2% vol/vol) decreased the LDH leakage (P less than 0.05). The cytosolic free Ca2+ concentration ([Ca2+]c) of rat hepatocytes exposed to Gal 4 mmol.L-1 for 90 min in suspension culture increased about 2-fold (P less than 0.01). Me2SO (2%) antagonized this [Ca2+]c-increasing effect of Gal. These results verified directly that the [Ca2+]c of hepatocytes was increased in the early stage of Gal-induced hepatotoxicity, and suggested that the prevention or lightening of the disturbance in intracellular Ca2+ homeostasis may be, at least, one of the mechanisms of the protective action of Me2SO against Gal-induced hepatocyte injury.


[Changes of the 5-HT content in hippocampus, midbrain-pons, spinal cord and concentration of blood glucose after intraperitoneal injection of ACTH in rats]. Effects of ACTH on the content of 5-HT in the hippocampus, midbrain-pons, and spinal cord and the concentration of blood glucose in rats by spectrofluorometric assay and glucose oxidase method were studied. ACTH ip 10 IU.kg-1 or 20 IU.kg-1 significantly increased the content of 5-HT in the hippocampus, midbrain-pons and spinal cord and blood glucose level, both in a dose-dependent manner; para-chloroaphetamine, p-Cpa 4 mg icv markedly reduced the 5-HT in these brain regions and spinal cord and the blood glucose level (P less than 0.01); the level of 5-HT and blood glucose were not significantly altered after icv p-Cpa+ip ACTH; adrenalectomy+ip ACTH markedly increased the 5-HT content in the brain regions and spinal cord, but the blood glucose was decreased (P less than 0.01); and 5-HT was markedly decreased by sc alloxan tetrahydrate+ip ACTH, but blood glucose did not decrease (P greater than 0.05). Thus, ACTH may influence the blood glucose level through central nervous system 5-HT, and the change of 5-HT may be related to the insulin (secretion).


[Effects of naphthylmethyl isoquinoline on contraction and calcium flux of rabbit vascular strips in vitro]. Naphthylmethyl isoquinoline (NI) 1-30 mumol.L-1 inhibited the contraction of rabbit vascular smooth muscle in vitro induced by KCl, CaCl2, and norepinephrine (NE). NI 0.3-30 mumol.L-1 blocked 45Ca2+ influx process in vascular smooth muscle of aorta, mesenteric and femoral arteries by addition of KCl and NE. NI 3-10 mumol.L-1 had no effect on 45Ca2+ efflux from aorta at resting state. These results suggest that the relaxing effect of NI on rabbit blood vessels may be relevant to the inhibition of Ca2+ influx into vascular smooth muscle.


MR imaging of experimental myocardial infarction. The signal enhancement in MR imaging of normal, infarcted and reperfused myocardium was investigated using different types of contrast agents. To investigate the organ distribution of a macromolecular contrast agent, normal rats were imaged before, and serially after injection of dextran-(Gd-DTPA)15. Dextran-(Gd-DTPA)15 had an essentially intravascular distribution, and significantly enhanced various organs in normal rats, including the heart. There was a linear relationship between the injected dose and observed enhancement. To investigate myocardial signal enhancement, acute myocardial infarction was induced in pigs by ligating a coronary artery. In two groups of pigs, dextran-(Gd-DTPA)15 or Gd-DPTA was administered i.v. after approximately 4 h of occlusion. Imaging was performed repeatedly in vivo. The animals were sacrificed about 2-2.5 h after injecting the contrast medium. The hearts were excised and re-imaged ex vivo. In three other groups of pigs, imaging was only carried out on excised hearts with 6-hour-old infarctions (a) without injecting contrast medium, (b) with injection of Dy-DTPA-BMA 3 min before sacrifice, and (c) with injection of Gd-DTPA-BMA 2 h before sacrifice followed by injection of Dy-DTPA-BMA 3 min before sacrifice. Without contrast medium, the infarctions were visualized as regions with a high signal intensity in the proton density- and T2-weighted images of excised hearts. Injection of dextran-(Gd-DTPA)15 resulted in infarct visualization also in the T1-weighted images ex vivo, due to a pronounced enhancement in parts of the infarct periphery and moderate enhancement in normal myocardium. Gd-DTPA accumulated in the infarctions, resulting in a better infarct visualization in the T1- and proton density-weighted images of excised hearts, compared with the control and dextran-(Gd-DTPA)15 groups. In vivo, however, the infarctions could not be visualized either before or after injection of dextran-(Gd-DTPA)15 or Gd-DTPA. Injection of Dy-DTPA-BMA improved infarct visualization mainly in the proton density- and T2-weighted images of excised hearts, due to susceptibility-induced reduction of signal intensity in the nonischemic myocardium. With T2-weighting, the infarct visualization was markedly better in the Dy-DTPA-BMA group than in the controls, or in the dextran-(Gd-DTPA)15 and Gd-DPTA groups. The double-contrast technique yielded an excellent infarct visualization ex vivo in all sequences, superior to that obtained in all other groups of pigs, due to Gd-DTPA-BMA-induced enhancement of the infarctions combined with Dy-DTPA-BMA-induced reduction of signal intensity in normal myocardium.(ABSTRACT TRUNCATED AT 400 WORDS)


Effect of antioxidants on chemiluminescence produced by reactive oxygen species. Luminol chemiluminescence was used to evaluate the scavenging of superoxide, hydroxyl and alkoxy radicals by four antioxidants: dipyridamole, diethyldithiocarbamic acid, (+)catechin, and ascorbic acid. Different concentrations of these compounds were compared with well-known oxygen radical scavengers in their capacity to inhibit the chemiluminescence produced in the reaction between luminol and specific oxygen radicals. Hydroxyl radicals were generated using the Fenton reaction and these produced chemiluminescence which was inhibited by diethyldithiocarbamate. Alkoxy radicals were generated using the reaction of tert-butyl hydroperoxide and ferrous ion and produced chemiluminescence which was inhibited equally by all of the compounds tested. For the determination of superoxide scavengers we describe a new, simple, economic, and rapid chemiluminescence method consisting of the reaction between luminol and horseradish peroxidase (HRP). With this method it was found that 40 nmol/l dipyridamole, 0.18 mumol/l ascorbic acid, 0.23 mumol/l (+)catechin, and 3 mumol/l diethyldithiocarbamic acid are equivalent to 3.9 ng/ml superoxide dismutase (specific scavenger of superoxide) in causing the same degree of chemiluminescence inhibition. These results not only indicated that the antioxidative properties of these compounds showed different degrees of effectiveness against a particular radical but also that they may exert their action against more than one radical.


A survey of FIV antibodies and FeLV antigens in free-roaming cats in the capital area of Finland. Feline immunodeficiency virus (FIV) was first isolated and identified in 1986. Since then it has been shown to have a worldwide distribution, and the infection generally appears to have reached a state of endemicity. This is the 1st study of FIV-prevalence in Finland. Serum samples of 196 free-roaming cats were tested for antibodies to FIV and FeLV antigens (Feline leukemia virus). With a combined enzyme-linked immunosorbent assay (ELISA), 13 of the cats (6.6%) turned out to be positive for FIV and 2 for FeLV (1.0%). Adult male cats in the capital area of Finland had a FIV prevalence of 24%, a relative proportion 4.7 times higher than that for females.


Increased genetic instability of the common fragile site at 3p14 after integration of exogenous DNA. We determined previously that the selectable marker pSV2neo is preferentially inserted into chromosomal fragile sites in human x hamster hybrid cells in the presence of an agent (aphidicolin) that induces fragile-site expression. In contrast, cells transfected without fragile-site induction showed an essentially random integration pattern. To determine whether the integration of marker DNA at fragile sites affects the frequency of fragile-site expression, the parental hybrid and three transfectants (two with pSV2neo integrated at the fragile site at 3p14.2 [FRA3B] and specific hamster fragile sites [chromosome 1, bands q26-31, or mar2, bands q11-13] and one with pSV2neo integrated at sites that are not fragile sites) were treated with aphidicolin. After 24 h the two cell lines with plasmid integration at FRA3B showed structural rearrangements at that site; these rearrangements accounted for 43%-67% of the total deletions and translocations observed. Structural rearrangements were not observed in the parental cell line. After 5 d aphidicolin treatment, the observed excess in frequency of structural rearrangements at FRA3B in the cell lines with pSV2neo integration at 3p14 over that in the two lines without FRA3B integration was less dramatic, but nonetheless significant. Fluorescent in situ hybridization (FISH) analysis of these cells, using a biotin-labeled pSV2neo probe, showed results consistent with the gross rearrangements detected cytogenetically in the lines with FRA3B integration; however, the pSV2neo sequences were frequently deleted concomitantly with translocations.(ABSTRACT TRUNCATED AT 250 WORDS)


Tissue breakdown and exposure associated with orbital hydroxyapatite implants. Tissue breakdown and exposure of a hydroxyapatite implant were observed in eight patients: in four of six patients after evisceration and in four of 31 after enucleation. The reasons for evisceration were a blind, painful eye and endophthalmitis in two patients each. The reasons for enucleation were a choroidal melanoma in two patients and endophthalmitis and irreparable traumatic damage in one patient each. The patients with endophthalmitis received the implant in a second surgical procedure after intensive antibiotic treatment. Small tissue defects healed spontaneously, whereas large defects showed little tendency to heal by secondary intention. Tissue breakdown over a hydroxyapatite implant may be related to delayed ingrowth of fibrovascular tissue, and possibly related to an inflammatory reaction incited by the hydroxyapatite. Careful case selection, facilitation of tissue penetration by drilling holes into the hydroxyapatite sphere, delayed fitting of the prosthesis, and vaulting of the posterior surface of the initial prosthesis to reduce pressure on the tissues covering the anterior pole of the implant may alleviate the problems of tissue breakdown and exposure.


Evaluation of higher-level auditory function in children with asymptomatic congenital cytomegalovirus infection. Higher-level auditory/cognitive functions were evaluated in 16 children: eight with asymptomatic congenital cytomegalovirus (CMV) infections and eight children documented not to have asymptomatic congenital CMV infections. Hearing sensitivity was within normal limits in all subjects. Results in both groups were within the normal range on the screening measures of verbal abilities, visual perception, social behavior, and memory span. In contrast, results of the auditory measures revealed abnormal dichotic speech perception, delayed latencies on auditory brainstem evoked responses, and disproportionately slow reaction times in a difficult listening condition (Stroop task). With the exception of dichotic speech perception, however, the pattern of auditory results suggested subtle disorders that were difficult to discern unequivocally with the small subject sample. Further studies are encouraged to determine the status of higher-level auditory/cognitive functions in children with asymptomatic congenital CMV infections.


Pleomorphic malignant fibrous histiocytoma: fact or fiction? A critical reappraisal based on 159 tumors diagnosed as pleomorphic sarcoma. Pleomorphic malignant fibrous histiocytoma (MFH) is regarded as the most common soft tissue sarcoma of adulthood, but no definable criteria exist for its diagnosis. Possibly its only distinctive feature is its apparent lack of specific differentiation. To determine the validity of pleomorphic MFH, 159 tumors diagnosed as pleomorphic sarcomas have been reassessed morphologically, immunohistochemically, and ultrastructurally, where possible. Of these 97 cases (63%) proved to be specific sarcomas other than MFH, 20 proved to be nonmesenchymal neoplasms, and 42 were unclassifiable (of which 21 were either small biopsies or subtotally necrotic). Only 13% of these cases were eligible for consideration as MFH, but these showed no reproducible histological differences from the other tumors studied, nor was this group morphologically consistent. These tumors showed no evidence of true monocyte/macrophage differentiation. It is postulated that pleomorphic MFH is a noncohesive heterogeneous group of poorly differentiated neoplasms, a term that has become a meaningless diagnosis of convenience. With sufficient effort, a specific line of differentiation can be identified in the majority of pleomorphic malignant soft tissue tumors; with advances in investigative technology, the proportion that remain unclassifiable is very likely to diminish further in the future.


Histological distribution of polymerase chain reaction--amplified human papillomavirus 6 and 11 DNA in penile lesions. The purpose of this study was to ascertain the histological pattern of distribution of human papillomavirus (HPV) 6 and 11 DNA in penile lesions by in situ hybridization after amplification by the polymerase chain reaction (PCR). HPV DNA was routinely detected by in situ hybridization with or without PCR amplification in granular layer cells that showed perinuclear halos and nuclear atypia. Cells that lack these histological features rarely exhibited HPV DNA with conventional in situ hybridization. However, after PCR amplification, in situ analysis showed that many of the cells that lacked halos and atypia contained HPV DNA. The hybridization signal often localized to crevices in the epithelium where there was relative hyperkeratosis and a thickened granular layer. HPV DNA was not noted in the basal cells and was rarely identified in other parts of the lesion. It is concluded that penile tissues may contain HPV DNA when lacking the diagnostic features of a condyloma/low-grade intraepithelial lesions and that such tissues usually demonstrate specific histological changes characterized by a focally thickened granular layer often associated with epithelial crevices.