Nuclear magnetic relaxation dispersion profiles of aqueous solutions of a series of Gd(NOTA) analogs. Nuclear magnetic relaxation dispersion (NMRD) profiles and ESR linewidths have been measured for a series of neutral Gd(3+)-triazamacrocyclic complexes and compared with previous data for the simplest member of the macrocyclic triaza series, Gd(NOTA), and for the widely studied linear triaza complex, Gd(DTPA)2-. Water proton relaxivities and their temperature dependence were found to vary widely with the size of the triaza macrocycle and the identity of the side-chain chelating groups. The number of rapidly exchanging water molecules directly coordinated to the Gd3+ ion (q) was found to vary from 2 to 4 for eight of the ten complexes examined and a linear relationship between the 50-MHz relaxivity value and integral values of q is presented for this series of complexes. tau s values derived from ESR linewidths for some of the complexes are in reasonable agreement with those derived from their NMRD profiles; however, those complexes which either tended to form aggregates in solution or gave evidence for multiple averaged solution structures showed broad, near Lorentzian linewidths which were clearly not dominated by the electron spin relaxation time (tau s).


Sensitivity of in vivo MRS of the N-delta proton in proximal histidine of deoxymyoglobin. The sensitivity of in vivo MRS of the N-delta proton of the proximal histidine of deoxymyoglobin in human skeletal muscles is discussed. Longitudinal relaxation time T1 of this deoxymyoglobin signal was measured in cuffed human forearms at 1.5 T and found to be 9.9 ms. Deoxymyoglobin spectra can be obtained from a forearm in seconds. The detection sensitivity of deoxymyoglobin in fully ischemic skeletal muscles and that of 31P MRS of PCr in normal resting muscles are compared.


T1 and T2 of ferritin at different field strengths: effect on MRI. Nuclear magnetic relaxation times T1 and T2 were measured in ferritin solutions at field strengths from 0.04 to 1.5 T. T1 was relatively constant, but 1/T2 increased linearly with field strength, in agreement with earlier MRI observations in the monkey brain. This finding supports the theory that ferritin is responsible for T2 shortening in brain nuclei containing iron. The linear dependence of 1/T2 on magnetic field is unique and not explained by present theories of the magnetic properties of ferritin.


MR imaging of cerebral perfusion by phase-angle reconstruction of bolus paramagnetic-induced frequency shifts. Phase-angle images are acquired dynamically during bolus paramagnetic contrast injection and demonstrate a phase-enhancement effect in perfused cerebral tissues. Signal-to-noise is comparable to that of susceptibility-based signal loss (delta R*) images. Assuming that phase shift is proportional to the tissue paramagnetic agent concentration, as supported by experimental data, the integrated area of the phase time response curves estimated the relative gray to white matter blood volume as 1.8:1 and was sensitive to acute ischemia. The relation between tissue phase shift and concentration is considered.


An investigation of tumor 1H nuclear magnetic resonance spectra by the application of chemometric techniques. 1H nuclear magnetic resonance (NMR) spectra of tumors and normal tissue include signals from all hydrogen-containing metabolites and can therefore be considered multicomponent multivariate mixtures. We have obtained 1H spectra from perchloric acid extracts of three normal tissues (liver, kidney, and spleen) and five rat tumors (GH3 prolactinoma, Morris hepatomas 7777 and 9618a, LBDS1 fibrosarcoma, and Walker 256 carcinosarcoma). We have applied several different chemometric methods to analyze the data. First, we used principal component analysis, cluster analysis, and an optimized artificial neural network to develop a classification rule from a training set of samples of known origin or class. The classification rule was then assessed using a set of unknown samples. We were able to successfully determine the class of each unknown sample. Second, we used the chemometric techniques of factor analysis followed by target testing to investigate the underlying biochemical differences that are detected between the classes of samples.


Simultaneous imaging of proton and fluorine at moderate field. Simultaneous imaging of proton and fluorine nuclei distributed in a unique sample has been performed by multiplexing the receiver coil's frequency for nmr signal acquisition. Implementation of the technique and modifications of a conventional spectrometer are described for operating at 0.13 T.


Physical training increases beta-adrenoceptor density and adenylate cyclase activity in high-oxidative skeletal muscle of diabetic rats. The effects of physical training on beta-adrenergic-receptor density (Bmax) and adenylate cyclase (AC) activity in soleus muscles (type I) and the deep red portion (type IIa) and superficial white portion (type IIb) of vastus lateralis muscles in diabetic rats were investigated. Rats were rendered diabetic with streptozotocin ([STZ] 45 mg/kg intravenously [IV]) and were either kept sedentary ([SD] n = 12) or submitted to a progressive 10-week treadmill running program ([TD] n = 13). A group of normal sedentary rats served as controls ([SC] n = 13). Plasma glucose levels were increased in SD rats in comparison with SC rats (21.3 +/- 1.4 mmol/L v 7.7 +/- 0.2; mean +/- SE, P < .001), but levels were partially reversed to normal by training (10.7 +/- 1.7; P < .01 v SD). The gastrocnemius nicotinamide adenine dinucleotide (NAD)-isocitrate dehydrogenase (ICDH) activity was significantly increased in TD rats in comparison to SC or SD rats (P < .001). The Bmax and antagonist affinity (Kd) determined with 125iodocyanopindolol (ICYP) were not affected by diabetes in any of the three types of muscle. In type I muscle, TD rats showed a significant 67% increase in Bmax compared with that of SD rats (TD 26.7 +/- 2.0 v SD 16.0 +/- 1.0; P < .001). In type IIa muscle, Bmax was significantly higher by 68% in TD rats as compared with SD rats (TD 16.5 +/- 1.7 v SD 9.8 +/- 0.9 fmol/mg protein; P < .01).(ABSTRACT TRUNCATED AT 250 WORDS)


Toxoplasma gondii: an AIDS enhancing cofactor. Disseminated toxoplasmosis, one of the most severe acquired immune deficiency syndrome (AIDS)-associated infections in humans, is believed to develop from a latent infection after the cellular immune system is suppressed by human immunodeficiency virus type 1 (HIV-1). However, Toxoplasma gondii may serve as a cofactor in enhancing the immunodeficiency induced by HIV-1. This hypothesis is supported by the facts that: 1) co-infection with other pathogens in humans infected with HIV-1 may enhance the progression of the disease to AIDS; and 2) concomitant infection with T. gondii enhances feline immunodeficiency virus-induced immune dysfunction and is likely to cause a more rapid disease onset than an infection with HIV alone. It is possible that T. gondii infection induces tumor necrosis factor (TNF) production. TNF then stimulates the induction of T-cell proteins that bind to the long terminal repeat of HIV-1. This binding at the repeat site then leads to increased HIV-1 activation which causes the dysfunction of CD4 cells and a resulting immunodeficiency that allows even greater amounts of T. gondii replication.


[Occupation and lung cancer risk in the province of Trieste: a case-control study]. To investigate the relationship between occupation and lung cancer, a case-control study was performed in the province of Trieste, Italy, where metallurgical and mechanical industries, dock activities and shipbuilding and ship repairing are predominant. Through the local Cancer Registry, pathology records of 938 men who died of primary lung cancer (ICD 162) in a five-year period were examined. Residential, smoking and occupational histories were obtained from interviews of next of kin of 756 cases and 756 age-matched male controls (+/- 2 years). Occupational exposures to lung carcinogens were assessed according to a job-title based approach, identifying industries/occupations with well-recognized lung carcinogen exposures (list A) and industries/occupations with suspected lung carcinogen exposures (list B). Exposure to asbestos was classified as absent, possible or definite. After adjustment for cigarette smoking (four levels) and residence (three levels), a significant association was found between lung cancer and occupations in list A (RR = 2.28, 95% CI = 1.70-3.07) and in list B (RR = 1.33, 95% CI = 1.04-1.71). A significant excess risk was found for workers with definite exposure to asbestos when compared to those with no exposure to lung carcinogens (RR = 1.99, 95% CI = 1.43-2.76). A very high relative risk was observed among heavy smokers with definite exposure to asbestos (RR = 42.8). A stratified analysis showed that the combined effect of asbestos and smoking was compatible with that expected under a multiplicative model. The overall attributable risk in the population (ARp) for cigarette smoking was found to be 87.6%. The ARp fraction for occupations with well-established exposures to lung carcinogens (list A) was 16.2%. The ARp fraction increased to 25.5% (85% CI = 1.4-34.6) when occupations with suspected exposure to lung carcinogens (list B) were included. The ARp fraction for possible or definite exposure to asbestos was 20.1% (95% CI = 11.6-28.6).


[Exposure to silicon carbide fibers in the production of carborundum]. Recent reports have shown that not only silicon carbide dusts but also fibres are liberated into the working environment during the various phases of silicon carbide production (using Acheson furnaces), thus creating a further potential health hazard. An environmental hygiene survey was conducted in a silicon carbide production plant with the aim of quantifying airborne dusts and fibres. Although dust levels were below 50% of the TLV, high concentrations of fibres were observed (analyzed via optical microscopy using the criteria for asbestos fibres), which in some locations reached levels of 2000 fibres/litre with means (GM) between 100 and 780 fibres/litre according to department. These results are assessed in the light of the growing interest of researchers in the experimental effects of silicon carbide fibres.


[Diffractometric analysis of non-pulverized coherent materials]. The paper presents an initial series of results of diffractometric assays, carried out by directing an X-ray beam on glossy sections of coherent, rigid materials (asbestos-cement blocks, insulation panels, ceramic tiles). The study, which is an introduction to another concerning crystalline rocks, is aimed at assessing the possibility of increasing the diffracted intensities, using samples with high mass concentration, avoiding the consequences of loss of crystallinity following extremely fine grinding, which is considerable especially when compounds having very different mechanical resistance and elastic modulus are simultaneously present. The assays carried out demonstrated the validity of the method for qualitative analysis, whereas in quantitative terms the diffracted intensities were mainly increased (up to 40%), but not in a manner directly connected with the type and macro- and microscopic structure of the compounds under study. Thus, the method guarantees an effective increase in sensitivity only in certain cases.


[An approach to the classification and assessment of asbestos-containing wastes: description of a survey conducted in an industrial area]. A survey was conducted in a unused textile plant, located in an urban area, where large quantities of solid wastes were stocked. They resulted from the dismantling of the heating system and contained different types of asbestos. The aim of the survey was to classify the wastes according to the criteria established by Italian law (Presidential Decree No. 915, 1982), which requires that "dusts and free fibres" be accounted for when determining the concentration of asbestos in waste. This legislation leaves two main questions open: i) the choice of the analytical method for asbestos determination that should be used to obtain basic information for waste classification; ii) the criteria to be used to define "free fibres" in waste. A general approach to the solution of these issues is offered and applied to the case in question as a possible practical model of environmental control in this specific field.


[Cytomegalovirus diseases following allogenic kidney transplantation]. Lymphotrophic virus infections, especially when they are caused by the cytomegalovirus, are severe complications after allogenic organ transplantation. First infections are mainly caused by donation of CMV-positive organs to CMV negative recipients. The regular incubation time of 30 to 40 days can be significantly shorter after therapeutic application with high dose prednisone or mono/polyclonal antibodies for treatment of rejection. The spectrum of clinical signs of the CMV-disease after organ transplantation can range between serological alterations and the lethal CMV-syndrome. The early recognition of virus-dependent clinical symptoms and the establishment of the diagnosis are the first conditions for the treatment, consisting in reduction of the immunosuppressive medication and application of ganciclovir, a CMV-specific virusstatic agent. The prophylactic application of CMV-hyperimmunoglobulin is discussed controversially. A very important aspect of CMV-disease in the long-term follow-up is the influence of this virus infection on the development of chronic organ rejection, which could be demonstrated in animal studies by application of the Marek virus and which was seen in pathomorphological samples of transplant biopsies. Future diagnostic and therapeutic strategies, which aim at the prolongation of the patient's survival and the transplant function have to consider the influence of virus infections as a severe risk-factor, as the transplantation of CMV-negative organs to CMV-negative recipients is more the exception than the rule.


[Incidence, prevention and therapy of cytomegalovirus and pneumocystis carinii infection after heart transplantation]. Diseases caused by cytomegalovirus (CMV) and pneumonia due to pneumocytis carinii (PCP) are problematic complications after allogeneic heart transplantation. Recipients of CMV-seropositive donors have a higher morbidity of CMV. By using an anti-CMV-immunoglobulin preparation in routine prophylaxis the incidence of CMV disease after heart transplantation could be reduced significantly. Ganciclovir 10 mg/kg is administered for treatment of CMV disease for at least 14 days. Recent investigations show that a prophylactic administration of ganciclovir after heart transplantation is safe, and it reduces the incidence of CMV-induced illness in CMV-seropositive patients. The incidence of PCP after heart transplantation varies according to the literature between 1 and 13%. The onset of the disease is located mostly between the third and the fifth month after heart transplantation. An effective prophylaxis can be achieved by low dose cotrimoxazole (960 mg at two days per week in adults) within the first six postoperative months. Cases of PCP are treated by cotrimoxazole or pentamidine and are associated with a mortality up to 60%.


[The cancerous recurrence of a pleomorphic adenoma of the parotid. Comments on a case]. After taking the clinical case examined as a starting point and supporting the data obtained with a literature analysis of the cancerous relapse of a parotid pleomorphic adenoma, the Authors suggested a suitable surgical operation (total parotidectomy with conservation of the facial nerve) in the treatment of parotid pleomorphic adenoma. Doing so, it is possible to avoid a relapse of neoplasm and a possible transformation into malignancy. Furthermore it might prevent the formation of parotid carcinoma.


Ryanodine as a functional probe of the skeletal muscle sarcoplasmic reticulum Ca2+ release channel. Ryanodine is a neutral plant alkaloid which functions as a probe for an intracellular Ca2+ release channel (ryanodine receptor) in excitable tissues. Using [3H]ryanodine, a 30 S protein complex comprised of four polypeptides of Mr 565,000 has been isolated and functionally reconstituted into planar lipid bilayers. The effects of salt concentration and divalent cations on skeletal muscle sarcoplasmic reticulum [3H]ryanodine binding and Ca2+ release channel activity have been compared. These studies suggest that ryanodine is a good probe for investigating the function of the release channel.


Reconstitution and regulation of an epithelial chloride channel. We have used a monoclonal antibody (MAb E12), one of several such antibodies raised against theophylline-treated Necturus gallbladder epithelial cells, to isolate a chloride channel protein by the use of an immunoaffinity column and FPLC. This protein (M(r) 219,000) has been reconstituted into a planar lipid bilayer, where it behaves as a chloride-selective channel (PCl/PNa = 20.2; PNa/PK = 1) whose unit conductance is 62.4 +/- 4.6 pS. Antibody added to the trans side (there is no effect from the cis side) causes channel open probability to drop to virtually zero, but has no effect on the conductance or the selectivity of single channels. To test the role of phosphorylation in the activity of the native channel, we studied the effects of the protein phosphatase inhibitor okadaic acid (OA) on intact gallbladders, and showed that channels opened by theophylline treatment and closed by antibody are reopened reversibly by OA (0.01-1.0 microM). Addition of the catalytic subunit of protein phosphatase 2A (PP-2A) to the cis side of a bilayer containing reconstituted chloride channels caused closure of the channels after a delay, and subsequent addition of ATP and the catalytic subunit of cAMP-dependent protein kinase (PKA) caused immediate reopening. These data indicate that (a) this chloride channel protein inserts in a directed way into the bilayer such that the cis side is 'intracellular', (b) the purified channel protein is phosphorylated, and (c) gating from the cellular side is controlled by the direct phosphorylation and dephosphorylation of the channel protein.


Aspirin, acetaminophen and proton transport through phospholipid bilayers and mitochondrial membranes. Mechanisms of proton transport were investigated in planar phospholipid bilayer membranes exposed to aspirin (acetylsalicylic acid), acetaminophen (4-acetamidophenol), benzoic acid and three aspirin metabolites (salicylic acid, gentisic acid and salicyluric acid). The objectives were to characterize the conductances and permeabilities of these weak acids in lipid bilayer membranes and then predict their effects on mitochondrial membranes. Of the compounds tested only aspirin, benzoate and salicylate caused significant increases in membrane conductance. The conductance was due mainly to proton current at low pH and to weak acid anion current at neutral pH. Analysis of the concentration and pH dependence suggests that these weak acids act as HA-2-type proton carriers when pH approximately pK and as lipid soluble anions at neutral pH. Salicylate is much more potent than aspirin and benzoate because salicylate contains an internal hydrogen bond which delocalizes the negative charge and increases the permeability of the anion. Model calculations for mitochondria suggest that salicylate causes net H+ uptake by a cyclic process of HA influx and A- efflux. This model can explain the salicylate-induced uncoupling and swelling observed in isolated mitochondria. Since ingested aspirin breaks down rapidly to form salicylate, these results may clarify the mechanisms of aspirin toxicity in humans. The results may also help to explain why the ingestion of aspirin but not acetaminophen is associated with Reye's syndrome, a disease characterized by impaired energy metabolism and mitochondrial swelling.


Regulation of renal epithelial sodium channels. The high selectivity, low conductance, amiloride-blockable, sodium channel of the mammalian distal nephron (i.e. cortical collecting tubule) is the site of discretionary regulation which allows maintainance of total body sodium balance. In order to understand the physiological events that participate in this regulation, we have used the patch-clamp technique which allows us to measure individual Na+ channel currents and permits access to the cytosolic side of the channel-protein as well as its associated regulatory components. Most of our experiments have utilized the A6 amphibian renal cell line, which when grown on permeable supports is an excellent model for the mammalian distal nephron. Different mechanisms have been examined: (1) regulation by hormonal factors such as Anti-Diuretic Hormone (ADH) and aldosterone, (2) regulation by G-proteins, (3) modulation by protein kinase C (PK-C), and (4) modulation by products of arachidonic acid metabolism. Consistent with noise analysis of tight epithelial tissues, ADH treatment increased the number of active channels in apical membrane patches of A6 cells, without any apparent change in the open probability (Po) of the individual channels. Agents that increased intracellular cAMP mimicked the effects of ADH. In contrast, aldosterone was found to act through a dramatic increase in Po rather than through changes in channel density. Inhibition of methylation by deazaadenosine antagonizes the stimulatory effect of aldosterone. In excised inside-out patches GTP gamma S inhibits channel activity, whereas GDP beta S or pertussis toxin stimulates activity suggesting regulatory control by G-proteins. PK-C has been shown to contribute to 'feed-back inhibition' of apical Na+ conductance in tight epithelia.(ABSTRACT TRUNCATED AT 250 WORDS)


Interaction of polypeptides with the gastric (H+ + K+)ATPase: melittin, synthetic analogs, and a potential intracellular regulatory protein. The 26 amino acid bee venom toxin, melittin, is an amphipathic helical polypeptide which inhibits the gastric (H+ + K+)ATPase. The site of interaction with the (H+ + K+)ATPase was shown to be the alpha subunit of the (H+ + K+)ATPase in studies using [125I]azidosalicylyl melittin, a radioactive photoaffinity analog of melittin. A synthetic amphipathic polypeptide (Trp3) containing tryptophan, which exhibits a structure similar to that of melittin, also inhibited the gastric (H+ + K+)ATPase, and prevented labeling by [125I]azidosalicylyl melittin. These findings suggested that melittin and the synthetic amphipathic helical polypeptide were bound to the same or overlapping site(s). In the present studies, novel tritiated photoaffinity analogs of Trp3 containing benzoylphenylalanine (in place of tryptophan) were used to photoaffinity label the (H+ + K+)ATPase. These studies help to establish that the (H+ + K+)ATPase contains a binding site for polypeptides which exhibit an amphipathic helical motif. The precise amino acid sequence of the polypeptide appears to be of secondary importance for interaction with the (H+ + K+)ATPase as long as the alpha helical motif is present. The benzoylphenylalanine containing polypeptides are ideal for mapping the binding site on the (H+ + K+)ATPase. Using an antibody which recognizes this amphipathic helical ('melittin-like') motif, we have demonstrated that the gastric parietal cell contains a 67 kDa 'melittin-like' protein. This protein was associated with the gastric parietal cell apical membrane in the stimulated (secreting) state, but not in the resting (non-secreting) state. The binding site for the gastric 'melittin-like' protein appears to overlap with the melittin binding site on the alpha subunit of the (H+ + K+)ATPase. The potential physiological significance of the melittin binding site and the overlapping binding site for this newly identified endogenous 'melittin-like' protein on the (H+ + K+)ATPase to regulated HCl secretion by the parietal cell is presently under investigation.(ABSTRACT TRUNCATED AT 250 WORDS)


Macromolecular crowding and volume perception in dog red cells. To differentiate whether the primary volume signal in dog red cells arises from a change in cell configuration or the concentration and dilution of cell contents, we prepared resealed ghosts that had the same surface area and hemoglobin concentration as intact cells but less than 1/3 their volume. Shrinkage of both intact cells and resealed ghosts triggered Na/H exchange. Activation of this transporter in the two preparations correlated closely with cytosolic protein concentration but not at all with volume. The Na/H exchanger was more sensitive to shrinkage in albumin-loaded resealed ghosts than in intact cells or ghosts containing only hemoglobin. Similar results were obtained for the swelling-induced [K-Cl] cotransporter. We believe perception of cell volume originates with changes in cytoplasmic protein concentration. We think the kinases and phosphatases that control the activation of membrane transporters in response to cell swelling or shrinkage are regulated by the mechanism of macromolecular crowding.


Ornithine decarboxylase is degraded by the 26S proteasome without ubiquitination. Ornithine decarboxylase (ODC), a key enzyme in polyamine biosynthesis, is the most rapidly turned over mammalian enzyme. We have shown that its degradation is accelerated by ODC antizyme, an inhibitory protein induced by polyamines. This is a new type of enzyme regulation and may be a model for selective protein degradation. Here we report the identification of the protease responsible for ODC degradation. Using a cell-free degradation system, we demonstrate that immunodepletion of proteasomes from cell extracts causes almost complete loss of ATP- and antizyme-dependent degradation of ODC. In addition, purified 26S proteasome complex, but not the 20S proteasome, catalyses ODC degradation in the absence of ubiquitin. These results strongly suggest that the 26S proteasome, widely viewed as specific for ubiquitin-conjugated proteins, is the main enzyme responsible for ODC degradation. The 26S proteasome may therefore have a second role in ubiquitin-independent proteolysis.


A whole genome approach to in vivo DNA-protein interactions in E. coli. The increasingly rapid pace at which genomic DNA sequences are being determined has created a need for more efficient techniques to determine which parts of these sequences are bound in vivo by the proteins controlling processes such as gene expression, DNA replication and chromosomal mechanics. Here we describe a whole-genome approach to identify and characterize such DNA sequences. The method uses endogenous or artificially introduced methylases to methylate all genomic targets except those protected in vivo by protein or non-protein factors interfering with methylase action. These protected targets remain unmethylated in purified genomic DNA and are identified using methylation-sensitive restriction endonucleases. When the method was applied to the Escherichia coli genome, 0.1% of the endogenous adenine methyl-transferase (Dam methylase) targets were found to be unmethylated. Five foreign methylases were examined by transfection. Database-matched DNA sequences flanking the in vivo-protected Dam sites all fell in the non-coding regions of seven E. coli operons (mtl, cdd, flh, gut, car, psp and fep). In the first four operons these DNA sequences closely matched the consensus sequence that binds to the cyclic AMP-receptor protein. The in vivo protection at the Dam site upstream of the car operon was correlated with a downregulation of car expression, as expected of a feedback repressor-binding model.


[Delayed-type allergy for heparin and fractions of low-molecular-weight heparin]. A patient is described with proven delayed type allergy for heparin and a low molecular heparin. A literature survey shows that the dermatological picture varies. Occurrence of erythematous plaques without a superficial dermatitis is possible. Epicutaneous tests are often not sufficient, and intracutaneous or even subcutaneous tests are necessary to demonstrate the allergy.


Induction of choline acetyltransferase in the neuroblastoma x glioma cell line NG108-15. The mechanism of the induction of choline acetyltransferase activity in the hybrid cell line NG108-15 was studied. Induction by cyclic AMP analogs, forskolin, and prostaglandin E1 + theophylline was found to be rapid with an increase in choline acetyltransferase specific activity detectable within 8 hrs and maximal after 24 hrs. Immunoblot analysis was used to demonstrate that the increase in choline acetyltransferase specific activity induced by prostaglandin E1 + theophylline was due to an increase in enzyme protein. Cycloheximide effectively blocked the induction of choline acetyltransferase by prostaglandin E1 + theophylline. These results demonstrate that the induction of choline acetyltransferase activity involves the synthesis of new enzyme protein. Attempts to measure choline acetyltransferase turnover by blocking its synthesis with cycloheximide indicated that this enzyme is a relatively stable protein with a half-life of greater than 24 hrs.


Further studies of the mechanism(s) of polyunsaturated-fatty-acid-mediated increases in intracellular cAMP formation in N1E-115 neuroblastoma cells. Following earlier observations that increasing the polyunsaturated fatty-acid (PUFA) content of N1E-115 neuroblastoma cells elevated basal and adenosine (Ado)-stimulated intracellular cyclic AMP (cAMP) formation, we carried out studies to determine the mechanism(s) by which PUFA exerted their modulatory effects. Basal increases in cAMP in the PUFA-enriched (PUFA+) cells were evident with short (60 sec) exposure to a phosphodiesterase inhibitor (Ro 20-1724), and increased to a maximum at 20 min; they were not observed in the absence of Ro 20-1724. Forskolin-stimulated cAMP formation in the presence of the Ro compound was 2- to 3-fold higher in the PUFA+ cells. Basal elevations in cAMP were reduced by approximately 70% by exposing the PUFA+ cells to Ado deaminase (ADA) or to an Ado antagonist, and were further increased by inhibiting ADA, which suggested that they could be producing endogenous Ado that activated stimulatory Ado receptors. However, this did not appear to involve PUFA-mediated stimulation of 5'-nucleotidase activity or inhibition of [3H]Ado uptake. Overall, the results of this study indicated that multiple mechanisms are involved in PUFA modulation of cAMP formation.


Opioid receptor antagonist affinity ligands: 6 beta-bromoacetamido-6-desoxynaltrexone and 6 beta-thioglycolamido-6-desoxynaltrexone. The present study, utilizing thioglycolamido as the reactive group, describes the synthesis and pharmacology of a new opioid antagonist affinity ligand, 6 beta-thioglycolamido-6-desoxynaltrexone (TAN) and compares TAN with a related known compound, 6 beta-bromoacetamido-6-desoxynaltrexone (BAN). Both compounds were tested for their reversible and irreversible inhibition of [3H]naloxone binding to calf brain membranes. Reversible binding of BAN and TAN had Ki values of 1 x 10(-9) and 1 x 10(-10) M, respectively as determined by log probit plots. Irreversible binding was determined after extensive washing to remove all non-covalently bound ligand. At a concentration of 5 x 10(-8) and 1 x 10(-8) M for BAN and TAN irreversible binding was inhibited 50% of the maximum value. A study of the time course of irreversible inhibition of [3H]naloxone binding revealed that maximal inhibition occurred within 5 min with a concentration of 1 x 10(-7) M of either agent. TAN but not BAN when administered systematically to mice produced an antinociceptive effect as measured by the writhing test. When administered intracerebraventricularly BAN did not block morphine-induced analgesia for more than 2 hr; whereas, with a single ED50 dose of 20 nmoles of TAN i.c.v. morphine-induced analgesia was almost completely blocked for a period of over 24 hr, as determined by the tail flick test. Although the SH group of TAN were required for the covalent interaction with opioid receptors, the site of TAN's interaction appears to involve other than protein SH groups.


Catecholamine-stimulated potassium transport in erythrocytes from normal and obese subjects. The beta adrenergic-modulated Na+/K+ ATPase pump rate of red blood cells was measured in vitro in 18 non diabetic obese patients. After challenge of erythrocytes with beta adrenergic selective agonist Salbutamol, the decrement of the K+ concentration in the suspending medium was assumed to be related to the Na+/K+ ATPase pump rate or to the number of beta 2 receptors. The mean K+ uptake was markedly increased in the erythrocytes of obese patients (1.58 mEq/l SD 0.18) if compared with 38 normal subjects (1.30 mEq/l SD 0.11) and with a population of 30 atopic patients that we have previously reported to have a reduced red cells beta 2 receptor activity (1.09 mEq/L SD 0.11). These results are not consistent with the hypothesis that a reduction in the Na+/K+ ATPase pump rate (at least in red blood cells) may be responsible for decreased metabolic rates leading to obesity. Since the autonomic nervous system is involved in the regulation of the cardiovascular system, it is conceivable that an increased Na+ ATPase pump rate (or supersensitivity) may be responsible of the increased incidence of hypertension, congestive heart failure and unexplained sudden death associated with obesity in some patients.


A glycine antagonist reduces ischemia-induced CA1 cell loss in vivo. Excessive activation of the N-methyl-D-aspartate (NMDA) receptor-channel complex has been implicated as one of the mechanisms by which ischemia-induced neuronal damage is mediated. Elevated glycine levels during ischemia may contribute to damage mediated by the NMDA receptor as glycine binding potentiates NMDA responses, and may be necessary for channel opening. We investigated the protective effects of 7-chlorokynurenic acid--a competitive antagonist at the glycine binding site associated with the NMDA receptor--against hippocampal CA1 cell loss induced by transient forebrain ischemia in rats. Intraventricular administration of the drug immediately before the onset of ischemia significantly attenuated neuronal loss compared to vehicle-treated animals.


A monoclonal anti-idiotypic 'internal image' antibody that recognizes the A1 adenosine receptor potentiates the alpha 1-adrenergic activation of phospholipase C in primary cultures of mouse striatal astrocytes. To determine which subtype of adenosine receptor mediates the potentiating effect of 2-chloroadenosine on the noradrenaline-induced inositol-phosphate formation, we used the monoclonal anti-idiotypic antibody AA1 that acts as an 'internal image' of adenosine and specifically recognizes the A1 adenosine receptor. In cultured mouse striatal astrocytes, AA1 increased the noradrenaline-evoked inositol phosphate (IP) accumulation, thus demonstrating a biological activity of an anti-idiotypic antibody. This effect was inhibited by PACPX, a selective A1 antagonist. Inhibitors of phospholipase A2 activity prevented the potentiation. These results establish the involvement of A1 adenosine receptors in the modulation of phospholipase C activity.


An intracellular study of the effects of GABA on frog tectal neurones in vitro. The effects of gamma-aminobutyric acid (GABA) on neurones of the amphibian optic tectum were studied with current- and voltage-clamp recording from an isolated preparation of the midbrain of the frog Rana temporaria. Bath-applied GABA (1 mM) enhanced depolarizing synaptic potentials evoked in layer 6 tectal neurones by orthodromic stimulation of the optic tract. GABA also facilitated Na(+)- and Ca(2+)-dependent action potentials elicited by intracellular injection of depolarizing current. These actions of GABA were associated with comparatively small changes in membrane potential and their reversal potential was dependent on the Cl- equilibrium potential. Changes in input resistance observed during application of GABA were small and in part accountable for by the rectifying properties of the cell membrane. Tetrodotoxin (TTX; 1 microM) did not block the action of GABA on these neurones. These results show that externally applied GABA was able to raise directly the intrinsic excitability of frog tectal neurones and to enhance excitatory synaptic transmission elicited by stimulation of optic nerve fibres.


Comparison of the effects of ACTH-(4-10) on medial vestibular nucleus neurons in brainstem slices from labyrinthine-intact and compensated guinea pigs. The effects of adrenocorticotrophic hormone fragment 4-10 (ACTH-(4-10)) on single medial vestibular nucleus (MVN) neurons, in brainstem slices from guinea pigs which had undergone vestibular compensation for a previous ipsilateral surgical unilateral labyrinthectomy, were compared with those on MVN neurons in slices from labyrinthine-intact guinea pigs observed in a previous study. Although the average resting discharge of MVN neurons in slices from compensated animals was significantly higher than that for MVN neurons from labyrinthine-intact animals, the responses of the two groups of MVN neurons to ACTH-(4-10) were very similar. These results suggest that ACTH-(4-10) treatment is unlikely to accelerate behavioral recovery following unilateral labyrinthectomy (vestibular compensation) by acting on a receptor within the MVN for which sensitivity to ACTH-(4-10) changes during the compensation process.


Regulation of regional cerebral blood flow by cholinergic fibers originating in the basal forebrain. We review mainly recent studies on vasodilative regulation of cortex and hippocampus by central cholinergic nerves originating in the basal forebrain. We also briefly review the influence of other central noradrenergic fibers originating in the locus ceruleus, serotonergic fibers originating in the dorsal raphe nucleus, dopaminergic fibers originating in the substantia nigra, and peripheral sympathetic and parasympathetic nerve fibers upon regulation of regional cerebral blood flow. Local metabolites have long been considered to play an important physiological role in regulating regional cerebral blood flow. However, the evidence reviewed here emphasizes that the regulation of regional cerebral blood flow by these central cholinergic nerves is independent of regional metabolism. We propose through this review that although studies investigating neural regulation of cortical and hippocampal blood flow by cholinergic fibers originating in the basal forebrain have added much to the understanding of regulation of regional cerebral blood flow further studies are needed to determine the physiological relevance of regional cerebral blood flow in relation to higher nervous functions such as memory, learning, and personality, and changes in these cognitive functions with aging and pathology such as Alzheimer's disease.


Properties of rhythmically active reticular neurons around the trigeminal motor nucleus during fictive mastication in the rat. Response properties of the neurons in the reticular formation around the trigeminal motor nucleus (MoV) were examined during cortically-induced fictive mastication (CIFM) in anesthetized and immobilized rats. Forty-three neurons were rhythmically active (RA neurons) during CIFM, most of which were located in the supratrigeminal nucleus and the reticular formation medial to the oral spinal trigeminal nucleus. The firing frequency of 36 of the RA neurons was modulated in the same rhythm as that of masseteric or digastric nerve activities during CIFM. We divided these neurons into four groups according to the phase of activation: sixteen neurons fired mainly in the phase of masseteric activity (type 1), 11 fired in the transition phase from masseteric activity to digastric activity (type 2), 5 fired in the phase of digastric activity (type 3) and 4 fired in the transition phase from digastric activity to masseteric activity (type 4). Thirty-nine (91%) of the 43 RA neurons responded to at least one of the tested peripheral stimuli. The responses were mostly excitatory but inhibitory responses were sometimes obtained, especially for types-1 and 2 neurons. RA neurons in the reticular formation medial to the oral spinal trigeminal nucleus responded to stimulation of inferior alveolar nerve at a shorter latency than RA neurons in the supratrigeminal nucleus. Fifteen (48%) of 31 RA neurons responded to triple-pulse stimulation of the contralateral cortex. In contrast, only 5(26%) of the 19 RA neurons responded to the ipsilateral cortical stimulation. Stimulation of the ipsilateral MoV was performed on 24 RA neurons, of which 9 responded antidromically (A-RA neurons) at latencies of 0.4-1.4 ms. Eight (89%) of the 9 A-RA neurons received peripheral inputs. The spike triggered averaging method was applied to 4 of the 9 A-RA neurons, ad in all cases short latency field potentials were recorded in the MoV. We conclude that trigeminal premotor neurons receive convergence from central and peripheral inputs. This integration can adjust the appropriate level of motoneuronal excitability during mastication.


The pyrroloquinoline quinone (PQQ) coenzymes: a case of mistaken identity. Recent evidence has failed to support the claim for a pyrroloquinoline quinone (PQQ) cofactor in mammalian enzymes previously reported to have PQQ. The validity of the original analysis now has been questioned, and a second cofactor, topa quinone, has been identified in at least one enzyme.


The addition of oatbran to a low fat diet has no effect on lipid values in hypercholesterolaemic subjects. to assess the hypocholesterolaemic effect of adding 50 g of oatbran to the diet of hypercholesterolaemic subjects already prescribed a diet with less than 30% of energy from fat. twenty-nine volunteers aged 21-67 years with total serum cholesterol levels 5.59-8.5 mmol/L prescribed a diet containing less than 30% of energy intake as fat, and with a body mass index between 19.8 and 29.3, were enrolled in a crossover study to assess the effect of the addition to the diet of 50 g daily of oatbran. After six weeks of an oat-free control diet, subjects were randomised to eat 50 g daily of oatbran or to continue on the oat-free diet. Six weeks later the subjects crossed to the alternative diet for a further six week period. Lipid levels were assessed in weeks five and six of each study period. twenty-four subjects completed the study consuming 51.7 (SD 15.5) g of oatbran daily during the treatment phase. No significant difference was seen between the oatbran and control diet periods in body mass index, energy or fat intake, or in total cholesterol, LDL and HDL fractions, apolipoprotein A1 and B levels, or triglyceride levels. Considerable variation was observed between the paired lipid results. ingestion of 50 g of oatbran daily by hypercholesterolaemic subjects on a low fat diet showed no influence on serum lipid levels. The importance of using at least duplicate samples in assessing changes in lipid values is emphasised.


Intracellular targeting of pp60src expression: localization of v-src to adhesion plaques is sufficient to transform chicken embryo fibroblasts. To define the effects of pp60v-src activity at different intracellular sites, we have constructed chimeric molecules which target the pp60v-src kinase to specific intracellular locations. pp60v-src was targeted to the nucleus by insertion of the SV40 large T antigen nuclear localization signal. Nuclear pp60v-src was active as a tyrosine kinase and phosphorylated nuclear proteins at tyrosine. However, cells expressing the nuclear pp60v-src were phenotypically normal by a number of criteria, and nuclear src kinase did not induce the expression of an mRNA (CEF-4) whose induction is characteristic of transformation by wild-type v-src. pp60v-src was targeted to perinuclear membranes by fusion to rat growth hormone and vesicular stomatitis G protein sequences. Cells expressing this chimeric molecule were phenotypically normal by most criteria. However the perinuclear src protein did induce elevated levels of CEF-4 mRNA, indicating that the v-src kinase expressed at this site induces partial transformation. The v-src and activated c-src kinases were targeted to adhesion plaques by fusion to the talin-binding sequence of vinculin. Cells expressing these fusion proteins were transformed by morphological, physiological and biochemical criteria, although the foci induced by these viruses were distinct from those induced by wild-type v-src. A chimeric protein which targeted c-src to adhesion plaques was not transforming. Thus targeting pp60src to adhesion plaques, although not sufficient to activate the transforming capacity of c-src, is sufficient to allow transformation by v-src.


p120, a novel substrate of protein tyrosine kinase receptors and of p60v-src, is related to cadherin-binding factors beta-catenin, plakoglobin and armadillo. A novel protein tyrosine kinase (PTK) substrate, p120, has been previously implicated in ligand-induced signaling through the epidermal growth factor, platelet-derived growth factor and colony-stimulating factor 1 receptors, and in cell transformation by p60v-src. We have isolated a near full-length cDNA encoding murine p120. The encoded protein lacks significant homology with any reported protein, but it contains four copies of an imperfect 42 amino acid repeat that occurs 12.5 times in the protein encoded by Drosophila armadillo (arm), and its direct homologs, human plakoglobin (plak) and Xenopus laevis beta-catenin (beta-cat). The presence of this motif implies that p120 may share at least one aspect of its function with the arm protein and its homologs.


Physical mapping of human loci homologous to the chicken nov proto-oncogene. The human locus (novH) corresponding to the nov protooncogene overexpressed in avian nephroblastoma has been identified and mapped on chromosome 8q24.1. Another locus sharing homology with novH and corresponding to the connective tissue growth factor (CTGF) gene has also been mapped on chromosome 6q23.1. The chromosomal assignment of nov and CTGF proximal to c-myc and c-myb respectively is of interest because chromosomal abnormalities involving these regions have been associated with different human tumors including Wilms'.


Identification of the cellular protein encoded by the human Wilms' tumor (WT1) gene. A putative tumor-suppressor gene (wt1) located at chromosome 11p13 and involved in Wilms' tumor development has recently been identified as a zinc finger polypeptide-encoding gene. The purpose of this study was to characterize the protein encoded by the human wt1 gene. The region spanning the entire zinc finger domain was amplified by polymerase chain reaction (PCR) and subcloned in the pATH 3 expression vector. Polyclonal antibodies against the fused TrpE-WT protein were raised. These antibodies immunoprecipitated a 49- to 51-kDa protein from hematopoietic tumor cells labeled in vivo with [35S]methionine. Subcellular fractionation and immunohistochemistry followed by confocal microscopy indicated that the Wilms' tumor gene product (WT1) is mainly localized within the nucleus.


Overexpression of the c-MET/HGF receptor gene in human thyroid carcinomas. The receptor for Hepatocyte Growth Factor is a transmembrane tyrosine kinase encoded by the c-MET oncogene. We have previously shown that the Met protein is expressed in several human epithelial tissues. The receptor is barely detectable, however, in normal thyroids and in specimens from patients affected by non-neoplastic thyroid diseases. Now we report that the expression of the Met/HGF receptor is increased a hundred fold in 22 out of 41 human carcinomas derived from the thyroid follicular epithelium. A comprehensive analysis of 15 cases showed that the overexpressing carcinomas belong to histotype variants correlated with negative prognosis and in all but one case there were evidences of locally advanced disease and/or distant metastases. The 11 benign adenomas and the 5 medullary carcinomas tested were negative. Western blot analysis with monoclonal antibodies directed against either the intracellular or the extracellular receptor domains failed to reveal major structural alterations. Southern blot analysis also demonstrated that the c-MET gene was not amplified nor rearranged. These data suggest a role for the overexpression of c-MET oncogene in the pathogenesis and progression of thyroid tumors derived from the follicular epithelium.


Safety and immunogenicity of oral tetravalent human-rhesus reassortant rotavirus vaccine in neonates. We conducted a prospective randomized double blind study to determine: (1) the safety and immunogenicity of live oral tetravalent human-rhesus rotavirus reassortant vaccine in neonates; and (2) whether a second dose at the age of 6 to 8 weeks enhances the immunogenicity. Two hundred forty healthy neonates were enrolled and received vaccine (183) or placebo (57) on the second day of life. At the age of 6 to 8 weeks 133 received placebo and 88 received a second dose of vaccine. Medical events were noted within 10 days from vaccine administration in 6 of 183 (3.3%) vaccine recipients vs. 0 of 57 placebo recipients (P = 0.34) after the first dose and in 8 of 88 (9%) vs. 4 of 133 (3%) after the second dose (P = 0.069); none was severe and all were of short duration. Seroresponse of any type (detectable IgA or 4-fold increase of titer to rhesus rotavirus was 9% for the placebo, vs. 52 and 46% for those who received one and two doses of vaccine, respectively. However, neutralizing antibodies against human serotypes 1, 2 and 3 were not raised successfully in vaccinated infants when compared with placebo recipients. The same pattern was found when geometric mean titers were compared. Vaccine take was better when cord blood titers were low. At the age of 1 year the vaccinees had more often high titers for antirhesus rotavirus antibodies (> 640) than the placebo recipients (49% vs. 0%; P < 0.001). NO difference was found between the groups in neutralizing antibodies to human serotypes 1, 2 and 3 rotavirus.(ABSTRACT TRUNCATED AT 250 WORDS)


Activity of cardiac L-type Ca2+ channels is sensitive to cytoplasmic calcium. Ca(2+)-induced inactivation of L-type Ca2+ channels is proposed as an important negative feedback mechanism regulating Ca2+ entry. Here, for the first time, evidence for modification of heart L-type Ca2+ channel activity by cytoplasmic calcium is provided from excised inside-out membrane patches. Ba2+ currents through cardiac L-type Ca2+ channels exhibited only modest inactivation in the absence of cytoplasmic Ca2+. Elevation of cytoplasmic Ca2+ to micromolar concentrations strikingly affected L-type Ca2+ channel activity as evaluated from ensemble average Ba2+ currents. Inactivation was markedly increased concomitant with a reduction of peak inward current, which was almost completely eliminated at about 15 microM cytoplasmic Ca2+ concentration. Half maximal suppression of Ba2+ currents was observed at 2.3 microM Ca2+. The observed modifications of L-type Ca2+ channel activity show that cytoplasmic Ca2+ induces channel closure. Below 4 microM Ca2+, channels can be reversibly reactivated during repetitive depolarizations, while at high Ca2+ concentrations (approximately 15 microM) most Ca2+ channels reside in a closed state. This may allow for a delicate regulation of Ca2+ entry, and consequently of heart contraction.


Mechanism of hyperthyroidism-induced modulation of the L-type Ca2+ current in guinea pig ventricular myocytes. The positive inotropic effects of thyroid hormone in the heart, increased force and velocity of contraction have been mostly attributed to modulation of myosin ATPase isoenzymes (V1, V2 and V3), and sarcoplasmic reticulum Ca2+ pumping activity. In addition, we have suggested that the effects on ventricular contraction result from a thyroid hormone-induced increase in L-type Ca2+ current (ICa,L). Due to the central role of ICa,L in excitation-contraction coupling, we studied mechanisms whereby thyroid hormone augments this current. Since thyroid hormone modulates adenylate cyclase activity in various tissues, we tested the hypothesis that the hormone activates adenylate cyclase, leading to increased cyclic adenosine monophosphate (cAMP) levels, protein kinase A activation, Ca2+ channel phosphorylation and increased ICa,L. We therefore stimulated or inhibited different sites along the "adenylate cyclase cascade", and measured ICa,L and isometric twitch in ventricular myocytes and papillary muscles from euthyroid and hyperthyroid guinea pigs. Our major findings were as follows. In euthyroid myocytes, 0.1 microM isoproterenol (Iso) increased ICa,L (at VM = 0 mV) from -7.04 +/- 0.72 to -22.26 +/- 1.88 pA/pF, P < 0.05, while in hyperthyroid myocytes (ICa,L = -21.48 +/- 2.94 pA/pF), Iso was ineffective. In euthyroid myocytes, intracellular application of cAMP (50 microM) was as potent as Iso, but ineffective in hyperthyroid myocytes. In hyperthyroid myocytes, a protein kinase A inhibitor (2 microM) lowered ICa,L from -26.82 +/- 1.54 to -10.17 +/- 1.70 pApF (P < 0.05), but had no effect in euthyroid myocytes.(ABSTRACT TRUNCATED AT 250 WORDS)


Isoprenaline reverses the slow force responses to a length change in isolated rabbit papillary muscle. An alteration in the length of isolated cardiac muscle produces an immediate change in twitch force, then a slow further change in the same direction. We have found that the slow changes in force in rabbit papillary muscles are blocked or reversed by the beta-agonist, isoprenaline (1 microM). The abolition of the slow responses by isoprenaline was not due to saturation of the myofibrils with Ca2+, as the blockade continued if the extracellular [Ca2+] was reduced in the presence of isoprenaline so that twitch force was < 50% maximal. Ryanodine (1 microM) did not block the slow responses, suggesting that the sarcoplasmic reticulum does not mediate the responses. These results suggest that changes of intracellular [cAMP] may mediate, or at least modulate, the slow force responses to a length change in cardiac muscle.


The E2 binding sites determine the efficiency of replication for the origin of human papillomavirus type 18. Human papillomaviruses (HPV-s) have been shown to possess transforming and immortalizing activity for many different, mainly keratinocyte cell lines and they have been detected in 90% of anogenital cancer tissues, which suggests a causative role in the induction of anogenital and other tumours. We have exploited a quantitative assay to identify and characterize the origin of replication of the human papillomavirus type 18 (HPV-18), one of the most prevalent types in the high-risk HPV group. Replication of HPV origin fragments was studied transiently by cotransfection with a protein expression vector providing replication proteins E1 and E2. We have localized the HPV-18 origin to nucleotides 7767-119. This region contains three E2 binding sites and an essential A/T rich DNA region (nucleotides 9-35) that is partly homologous to the E1 binding site found in bovine papillomavirus type 1 (BPV-1) genome. At least one of the three E2 binding sites was absolutely required for origin function; addition of other E2 sites had cooperative stimulating effect. This is the first quantitative analysis of the E2 binding sites for papillomavirus replication.


Purification and properties of the Eco57I restriction endonuclease and methylase--prototypes of a new class (type IV). The Eco57I restriction endonuclease and methylase were purified to homogeneity from the E.coli RR1 strain carrying the eco57IRM genes on a recombinant plasmid. The molecular weight of the denaturated methylase is 63 kDa. The restriction endonuclease exists in a monomeric form with an apparent molecular weight of 104-108 kDa. R.Eco57I also possesses methylase activity. The methylation activities of both enzymes modify the outer A residue in the target sequence 5'CTGAAG yielding N6-methyladenine. M.Eco57I modifies both strands of the substrate while R.Eco57I modifies only one. Only the methylase enzyme is stimulated by Ca2+. The restriction endonuclease shows an absolute requirement for Mg2+ and is stimulated by AdoMet. ATP has no influence on either activity of the enzymes. The subunit structure and enzymatic properties of the Eco57I enzymes distinguish them from all other restriction-modification enzymes that have been described previously. Therefore, RM.Eco57I may be regarded as a representative of a novel class of restriction-modification systems, and we propose to classify it as type IV.


Cloning and sequence analysis of the genes coding for Eco57I type IV restriction-modification enzymes. A 6.3 kb fragment of E.coli RFL57 DNA coding for the type IV restriction-modification system Eco57I was cloned and expressed in E.coli RR1. A 5775 bp region of the cloned fragment was sequenced which contains three open reading frames (ORF). The methylase gene is 1623 bp long, corresponding to a protein of 543 amino acids (62 kDa); the endonuclease gene is 2991 bp in length (997 amino acids, 117 kDa). The two genes are transcribed convergently from different strands with their 3'-ends separated by 69 bp. The third short open reading frame (186 bp, 62 amino acids) has been identified, that precedes and overlaps by 7 nucleotides the ORF encoding the methylase. Comparison of the deduced Eco57I endonuclease and methylase amino acid sequences revealed three regions of significant similarity. Two of them resemble the conserved sequence motifs characteristic of the DNA[adenine-N6] methylases. The third one shares similarity with corresponding regions of the PaeR7I, TaqI, CviBIII, PstI, BamHI and HincII methylases. Homologs of this sequence are also found within the sequences of the PaeR7I, PstI and BamHI restriction endonucleases. This is the first example of a family of cognate restriction endonucleases and methylases sharing homologous regions. Analysis of the structural relationship suggests that the type IV enzymes represent an intermediate in the evolutionary pathway between the type III and type II enzymes.


DNA substrate specificity of DNA helicase E from calf thymus. DNA helicase E from calf thymus has been characterized with respect to DNA substrate specificity. The helicase was capable of displacing DNA fragments up to 140 nucleotides in length, but was unable to displace a DNA fragment 322 nucleotides in length. DNA competition experiments revealed that helicase E was moderately processive for translocation on single strand M13mp18 DNA, and that the helicase would dissociate and rebind during a 15 minute reaction. Comparison of the rate of ATPase activity catalyzed by helicase E on single strand DNA substrates of different lengths, suggested a processivity consistent with the competition experiments. The helicase displayed a preference for displacing primers whose 5' terminus was fully annealed as opposed to primers with a 12 nucleotide 5' unannealed tail. The presence of a 12 nucleotide 3' tail had no effect on the rate of displacement. DNA helicase E was capable of displacing a primer downstream of either a four nucleotide gap, a one nucleotide gap or a nick in the DNA substrate. Helicase E was inactive on a fully duplex DNA 30 base pairs in length. Calf thymus RP-A stimulated the DNA displacement activity of helicase E. These properties are consistent with a role for DNA helicase E in chromosomal DNA repair.


The Florey Lecture, 1992. The secretion of proteins by cells. In eukaryotic cells, protein secretion provides a complex organizational problem. Secretory proteins are first transported, in an unfolded state, across the membrane of the endoplasmic reticulum (ER), and are then carried in small vesicles to the Golgi apparatus and finally to the cell membrane. The ER contains soluble proteins which catalyse the folding of newly synthesized polypeptides. These proteins are sorted from secretory proteins in the Golgi complex: they carry a sorting signal (the tetrapeptide KDEL or a related sequence) that allows them to be selectively retrieved and returned to the ER. This retrieval process also appears to be used by some bacterial toxins to aid their invasion of the cell: these toxins contain KDEL-like sequences and may, in effect, follow the secretory pathway in reverse. The membrane-bound receptor responsible for sorting luminal ER proteins has been identified in yeast by genetic means, and related receptors are found in mammalian cells. Unexpectedly, this receptor has a second role: in yeast it is required to maintain the normal size and function of the Golgi apparatus. By helping to maintain the composition of both ER and Golgi compartments, the KDEL receptor has an important role in the organization of the secretory pathway.


Tetracycline enhances Tn916-mediated conjugal transfer. Pregrowth of the donor on medium containing tetracycline increased conjugative transposition of Tn916 and the transposon-dependent mobilization of pC194 19- to 119-fold in matings between Bacillus subtilis and Bacillus thuringiensis subsp. israelensis. Tn916 and pC194 transferred independently under these conditions. When Enterococcus faecalis was the donor and B. thuringiensis subsp. israelensis the recipient, pregrowth in tetracycline increased the conjugative transposition frequency by approximately 15-fold. Tetracycline-enhanced conjugation appeared during matings as short as 3 h in length. Pregrowth in tetracycline did not enhance conjugation in Bacillus sphaericus x B. thuringiensis subsp. israelensis or B. thuringiensis subsp. israelensis x B. subtilis matings. Incorporation of tetracycline into the mating medium, at concentrations that did not inhibit growth of the B. thuringiensis subsp. israelensis recipient, resulted in conjugation frequencies similar to those obtained by pregrowth of the B. subtilis donors in antibiotic-containing medium. The data suggest stimulation of donor function by tetracycline.


The integron In1 in plasmid R46 includes two copies of the oxa2 gene cassette. The sequence of the insert region of the integron In1 found in the IncN plasmid R46 was completed. The insert region is 2929 bases long and includes four gene cassettes, two of which are identical copies of the oxa2 gene cassette flanking an aadA1 cassette. The fourth cassette encodes an open reading frame orfD. From comparison of these data with published maps and sequences it is argued that the integrons found in the IncN plasmids pCU1 and R1767 and in the transposon Tn2410 are closely related to In1 from R46. Both site-specific gene insertion and recA-dependent recombination are likely to have contributed to the evolution of these integrons.


Multiple copies of IS256 in staphylococci. EcoRI-digested cellular DNAs of 150 staphylococcal clinical isolates were probed with a plasmid containing a DNA piece from within the open reading frame of IS256. Most of the Gmr staphylococcal isolates tested contained more copies of IS256 than those associated with Tn4001 carried by these isolates. Three distinct copies of IS256 together with their flanking DNA were isolated by cloning from an EcoRI digest of the cellular DNA of the Gmr isolate, BM3121. These three copies of IS256 were shown to be intact. The results from DNA sequencing revealed that one of the three copies is flanked by 8-bp direct repeats, and it is suggested that this may be the result of insertion of the IS256 at this site by autonomous movement of the IS element. The insert DNA of all three clones hybridized to the cellular DNA prepared from a Staphylococcus aureus strain that carries neither IS256 nor the aacA-aphD gene. Two of the clones hybridized to several EcoRI fragments of the cellular DNA of this strain, indicating that in these cases IS256 is flanked by DNA present as several copies on the chromosome.


A stable Escherichia coli-Mycobacterium smegmatis plasmid shuttle vector containing the mycobacteriophage D29 origin. A plasmid shuttle vector for Escherichia coli and mycobacteria was constructed from an E. coli plasmid containing the ColE1 origin, a 2.6-kb PstI fragment from bacteriophage D29 that grows in numerous mycobacterial species, and the kanamycin resistance gene either of Tn903 or of Tn5. The resultant plasmid is 7.63 kb and can be introduced via transformation into Mycobacterium smegmatis with high efficiency. In M. smegmatis the plasmid is stable and apparently present in multiple copies. Bioluminescence (luxA and luxB of Vibrio harveyi and fischeri) has been expressed in M. smegmatis from the aminoglycoside transferase promoter of Tn5. The D29 fragment should carry an origin of replication and some associated genes that act on it since various mutations destroy the ability of this fragment to replicate in M. smegmatis. The fragment was localized on the D29 genome map.


Aerobic fitness and opioidergic inhibition of cardiovascular stress reactivity. The role of endogenous opioids in aerobic fitness-induced decrements in cardiovascular stress reactivity was examined by comparing the effects of opioid antagonism with naltrexone on responses to stress in young adults with high versus low levels of aerobic fitness. Two hundred forty subjects were given an activity questionnaire and males with the highest (Fit) and lowest (Nonfit) aerobic activity profiles were recruited for maximal oxygen consumption (VO2max) treadmill testing and psychological stress testing (final sample N = 28). Heart rate and blood pressures were measured during performance on a computer-controlled arithmetic task after pretreatment with either naltrexone (Trexan, DuPont) or a placebo. During placebo challenges, Fit subjects, compared with Nonfit, showed lower heart rate reactivity during stress and lower mean arterial blood pressures immediately before and during recovery from stress. Naltrexone eliminated these reactivity differences by increasing heart rate reactivity and raising mean arterial blood pressure in Fit subjects. These data suggest that aerobic fitness is associated with enhanced opioidergic inhibition of circulatory stress reactivity. Opioidergic modulatory effects on stress reactivity may comprise an important mechanism in fitness-associated risk reduction for cardiovascular disease.


Cardiac autonomic mechanisms associated with borderline hypertension under varying behavioral demands: evidence for attenuated parasympathetic tone but not for enhanced beta-adrenergic activity. Elevated blood pressure in psychophysiological studies of borderline hypertension is frequently attributed to the effects of increased sympathetic tone, and with few exceptions, the potential parasympathetic contributions have not been considered. Furthermore, of the investigations that have addressed vagal influences upon blood pressure, most have employed invasive pharmacological assessment of parasympathetic tone. In this study, cardiac parasympathetic and beta-adrenergic influences in borderline hypertension were evaluated noninvasively employing respiratory sinus arrhythmia as a vagal index and preejection period as a sympathetic index of cardiac functioning. Subjects were 30 borderline hypertensive and 23 normotensive males (age range, 24-45 years). The ECG, blood pressure, impedance cardiography, and respiration were measured during two baselines (initial and post-task), a memory-comparison reaction time task, the cold pressor, and CO2-rebreathing. Results indicated tonic differences between groups in all cardiovascular variables across tasks, with the exception of pre-ejection period, which showed no group effects at all. Hypertensives additionally manifested somewhat heightened systolic blood pressure reactivity and attenuated cardiac parasympathetic responsivity to specific tasks. Our findings provide no support for an exaggerated cardiac beta-adrenergic tonic level or reactivity in borderline hypertensives. On the other hand, the consistently lower magnitude of respiratory sinus arrhythmia in our hypertensives suggests that reduced parasympathetic control may be involved in the pathophysiology of hypertension.


[Does color Doppler complement breast examination?]. Improvements in breast cancer detection are underway with work being done on different imaging techniques and the assessment of abnormal vascularity. In an earlier study we used a 10 MHz CW Doppler pencil probe. In palpable carcinomas 94% had shown abnormal vascularity. However, in nonpalpable lesions, this method did not allow flow detection in combination with imaging. Recent developments in color flow mapping allow detection of small tumor vessels, which are invisible on B-mode ultrasound. Registration of vessels simultaneously to B-mode imaging allows this method to be used for nonpalpable lesions. The sensitivity of diverse Doppler instruments shows remarkable differences. This makes uniform evaluation of the method difficult. We examined 94 symptomatic women using different equipment. In 9 of 32 carcinomas no Doppler signals were found. However, CW Doppler showed low vascularity in these 9 false-negative cases. However, the variation of vascularity in malignancies does not yet allow routine application of this method and needs further scientific evaluation.


Beneficial effect of dibutyryl cyclic AMP (DBcAMP) on ischemic acute renal failure in the rat. To determine the effect of dibutyryl cyclic AMP (DBcAMP) on ischemic acute renal failure (IARF), that disorder was induced in male Wistar rats. After the animals were anesthetized with sodium pentobarbital (50 mg/kg, i.p.), the right kidney was removed and the left renal pedicle was clamped for 60 min. DBcAMP (5 mg/kg, i.p.) was given each 30 min before and after the renal pedicle clamping in half the dose each. Twenty-four hours after surgery, the levels of serum creatinine, BUN, serum potassium, and FENa% were significantly less elevated; and the total urine volume was significantly less decreased for 24 h in the group of IARF given DBcAMP than in the group of IARF alone. The elevation in Ca2+ content of the renal cortex was also significantly lower in the group of IARF given DBcAMP than in the group of IARF alone. These data indicate that DBcAMP can produce a beneficial effect on experimentally induced IARF. Since the intracellular accumulation of Ca2+ has been reported to be a potentially harmful factor in the development of IARF, it is suggested that the effect of DBcAMP on IARF can be in part due to an inhibition of the intracellular accumulation of Ca2+ in the kidney.


Captopril does not protect against renal oxidative injury. The free thiol group of captopril is important in the action and metabolism of this drug. It has been postulated that the thiol group may allow captopril to act in a manner similar to glutathione and protect against oxidative injury. This study investigated the ability of captopril, enalaprilat, and N-acetylcysteine to prevent tertbutyl hydroperoxide induced oxidative injury in rat renal homogenates. Lipid peroxidation was significantly increased in homogenates from captopril-treated animals (p < 0.05), and following glutathione depletion this was further enhanced (p < 0.001). Renal glutathione content was significantly reduced by captopril treatment (p < 0.01). These results suggest that captopril does not act as an alternate source of reducing equivalents to glutathione and does not protect against renal oxidative injury in this model.


[Peripheral neuropathy associated with Castleman's lymphoma]. Castleman's lymphoma is a rare clinicopathological entity and is often difficult to classify nosographically. From the histopathological point of view two variants are recognized, one hyalino-vascular and one plasma cellular. Moreover Castleman's lymphoma may be multifocal or unifocal (located within the thorax in 70% of patients). The plasma cellular variant is often associated with systemic symptoms such as fever, sweating, organomegaly, polyneuropathy, and mono- or polyclonal gammopathy. We describe a rare case of unifocal, plasma cellular-type Castleman's lymphoma located in the mediastinum, asymptomatic at onset but later dominated by neurological symptoms (chronic isolated polyneuropathy whose clinical expression was predominantly motor). A brief review is presented of the main clinico-histological characteristics of Castleman's lymphoma together with some hypotheses about the pathogenesis of the associated neuropathy.


Effects of BRB-I-28, a novel antiarrhythmic agent, and its derivatives on cardiac Na+,K(+)-ATPase, Mg(2+)-ATPase activities and contractile force. The effects of BRB-I-28, SAZ-VII-22 and SAZ-VII-23, a novel class of antiarrhythmic agents and other 3,7-diheterobicyclo[3.3.1]nonane (DHBCN) derivatives on guinea pig myocardial Na+,K(+)-ATPase and Mg(2+)-activated ATPase activities were investigated in comparison with those of tedisamil, lidocaine and ouabain. BRB-I-28, SAZ-VII-22, SAZ-VII-23, tedisamil and their derivatives produced concentration-dependent inhibition on both Na+,K(+)-ATPase and Mg(2+)-activated ATPase. Ouabain had no effect on the Mg(2+)-activated ATPase activity and GLG-IV-44 had no significant inhibition on Na+,K(+)-ATPase. Molar refractivity, retention time in reverse-phase HPLC, and partition coefficients were determined and the influence of these three parameters on the inhibitory effects of DHBCN on ATPase was examined. It seems that inhibitory effects of DHBCN derivatives on Na+,K(+)-ATPase and Mg(2+)-activated ATPase increase with an increase in lipophilicity, while hydrophilic groups of the drugs may not be important for interaction between drugs and ATPases. The effects of BRB-I-28 on contractile force development in rabbit atrial and papillary muscles were studied. At paced rates of 0.5 and 1.0 Hz in atrial muscle, BRB-I-28 produced an apparent positive inotropic effect in isolated rabbit atrial muscle, which is consistent with its inhibitory effects on Na+,K(+)-ATPase and Mg(2+)-ATPase activities. Inhibitory effects on myocardial Na+,K(+)-ATPase and Mg(2+)-activated ATPase activities may be the basis of some electrophysiological effects of antiarrhythmic properties of BRB-I-28, SAZ-VII-22, SAZ-VII-23, and tedisamil.


Clinical trials with the topoisomerase I inhibitors. Topoisomerase I represents a unique new target that can be exploited for development of new antineoplastic agents. There are now two new topoisomerase I inhibitors that are in early clinical trials that have generated a tremendous amount of interest. Topotecan (SKF 104864-A) is a topoisomerase I inhibitor that has been explored in phase I trials using a variety of dosages and schedules. The dose-limiting toxicity of the agent is neutropenia. Other toxicities include alopecia, very mild nausea and vomiting, anemia, and occasional fever. Responses have already been noted in patients with advanced, refractory ovarian cancer and non--small-cell lung cancer. The drug is currently undergoing intense phase II testing. Irinotecan (CPT-11) is also a topoisomerase I inhibitor, which has already undergone extensive phase I and early phase II clinical testing in both Japan and the United States. Dose-limiting toxicities of the agent have included neutropenia and diarrhea. Responses have been noted in patients with refractory colorectal cancer, non--small-cell lung cancer, lymphoma, ovarian cancer, head and neck cancer, pancreatic cancer, and breast cancer. There is no doubt both of these agents will be important additions to our chemotherapy armamentarium.


The current status of toxicity protectants in cancer therapy. Current therapies for the treatment of malignancies are associated with significant toxicity, as chemotherapy and radiation therapy do not discriminate between normal and malignant cells. One approach to ameliorating the toxicity associated with therapy is through the use of chemoprotective agents. This article reviews a variety of agents that have been evaluated as possible protectants, including WR-2721 and the colony-stimulating factors. It is hoped that the understanding of how to optimally use chemoprotective agents will lead to more tolerable treatments for patients, and possibly allow for dose-escalation, which may contribute to improvement in patient survival.


Redundant nerve roots of the cauda equina caused by lumbar spinal canal stenosis. To investigate pathogenesis of redundant nerve roots of the cauda equina, which were concomitant with severe lumbar spinal canal stenosis, six cadavers were examined anatomically and histopathologically, and quantitative analysis of nerve fibers was performed. In this anatomic study, it was observed that all the redundant nerve roots passed through the constriction of the spinal canal. No significant pathologic change was detected in the spinal ganglia and in the spinal cords except for the posterior column, in which dorsal redundant roots were entering. Redundant nerve roots of unequal length also were observed in the anatomic study. The spatial distribution of redundant nerve roots and the extent of degeneration of nerve fibers in them were established by these histopathologic and quantitative studies. These facts indicated a close causal relationship between redundant nerve roots and constriction of the spinal canal, and that the pathogenesis of redundant nerve roots was a squeezing force acting on the nerve roots at the area of spinal canal constriction.


[Cough during treatment with angiotensin-converting enzyme inhibitors is gender related]. In a Norwegian, double-blind, double-dummy multicenter study, 828 patients with mild to moderate hypertension were randomized to treatment by either lisinopril or nifedipine. One of the aims of the study was to specifically investigate the frequency of side effects. Spontaneously reported coughing reached 8.5% for lisinopril, as against 3.1% for nifedipine. In two patients coughing led to withdrawal from the study, and in another three it contributed partially to discontinuation of the treatment. A significant sex difference was found for spontaneously reported coughing among patients on lisinopril; 12.6% of the women and 4.4% of the men. A similar difference between the sexes was found for specific questioning about coughing. Use of a visual analogue scale by both patient and spouse revealed similar frequency of coughing as when reported spontaneously. The reason for sex being an important determinant for lisinopril-induced coughing remains obscure.


[Treatment with lisinopril or nifedipine in essential hypertension. A Norwegian multicenter study of the effect, tolerance and quality of life of 828 patients]. In a randomized, parallel, double-blind study, lisinopril (n = 412) reduced systolic and diastolic blood pressure more than nifedipine did (n = 416) after ten weeks treatment in patients (40-70 years) with mild to moderate essential hypertension. Lisinopril was tolerated better than nifedipine, with fewer withdrawals. Adverse experiences reported after a general question on discomfort were significantly lower for lisinopril than for nifedipine. Questions referring specifically to symptoms revealed higher frequency of coughing with lisinopril, while flushing, edema, palpitations, dizziness, tiredness and rash were reported more frequently with nifedipine. Quality of life was similarly assessed by both patients and spouses. No significant differences in well-being during treatment were found for either drug, except in the case of the highest dose level of nifedipine, which caused a deterioration of well-being.


[Secretion of soluble receptors for tumor necrosis factor. An immunologic buffer mechanism during normal pregnancy?]. High concentrations of tumour necrosis factor may threaten the well-being of the foetus. Secretion of soluble cytokine receptors has been suggested as a mechanism for regulating cytokine activity in vivo. In this study pregnancy-related materials were examined for the presence of soluble receptors (p55 and p75) for tumour necrosis factor. In contrast to control materials, serum and urine samples from pregnant women and newborns contained high concentrations of p55, and p55 was highly expressed by villous syncytiotrophoblasts. Thus, the present data suggest that shedding of specific receptors may contribute to the regulation of tumour necrosis factor activity throughout a normal pregnancy.


[Comparative clinical study of 2 antibiotic injectable preparations in the treatment of airway infections in veal calves]. The results of a comparative clinical study in which two injectable antibiotic preparations, containing enrofloxacin or neomycin-procaine penicillin were used, are reported. Four outbreaks of pneumonia in 186 calves on two farms were included in the study. Both preparations were used at a dose rate of 1 ml per 20 kg body weight for five, consecutive days. The clinical efficacy of both preparations was high (cure rates of 96 and 98%) and the clinical scores following treatment for each preparation were very much the same throughout the trial period. After the first treatment, more than 50% of the animals were considered to be healthy, after three treatments this percentage had increased to more than 80%.


Alteration of thymic cell subsets by cocaine administration and murine retrovirus infection in protein undernourished mice. Retrovirus infection, cocaine administration, and nutritional deficiencies are known to individually produce impairment of the immune system. Therefore, we developed a murine model to study the effect of daily cocaine administration, protein malnutrition, and retrovirus infection causing murine AIDS on the lymphoid cell populations of the thymus. C57BL/6 female mice fed a diet containing 4% protein were studied following chronic cocaine administration and LP-BM5 murine leukemia virus (MuLV) infection. Cocaine administration reduced body and thymus weight. Cocaine partially prevented thymus enlargement due to lymphoid cell proliferation induced by murine retrovirus infection. Cocaine treatment affected dramatically the thymus of protein-malnourished mice where the absolute number of Thy 1.2+, CD4+ and CD8+ cells represented only 10% of the control values. Daily saline injection also induced a significant decrease in the number of Thy 1.2+, CD4+ and CD8+ cells per thymus. These results suggest that the thymus glands of mice fed a low protein diet were susceptible to stress. Retrovirus infection provoked a decrease in the percentage and absolute number of Thy 1.2+, CD4+ and CD8+ cells in the thymus. This effect was potentiated by cocaine treatment. Therefore, cocaine was able to potentiate the impairment of the immune system caused by MuLV infection. We consider that cocaine could alter the immune system by altering the expression of T cell differentiation markers after direct interaction with thymocytes or through the neuroendocrine-thymus axis. Moreover, this effect was more dramatic and severe during protein malnutrition.


[Multimicrobial pulmonary infection in an AIDS patient]. A case of a 44 year old male AIDS patient with multimicrobial lung infection is presented. Six possible pathogens were found and the relative importance of these is discussed. An active diagnostic and therapeutic approach is recommended when treating AIDS patients with pneumonia.


[Clinical use of intravenous immunoglobulin IgG]. Intravenous human immunoglobulins (IVIG) are valuable in the treatment of several immunodeficiency and autoimmune diseases. The classic, well-known indications are primary hypogammaglobulinaemic conditions, immune thrombocytopenia and Kawasaki's syndrome. IVIG's content of specific antibodies toward a series of known, pathogenic microorganisms has led to the treatment of a number of infectious conditions and IVIG has a documented effect on AIDS in children, prophylactically in cases with potentially life-threatening CMV infections in certain types of transplants and prophylactically in hypogammaglobulinaemic patients with the most common variety of leukaemia, chronic lymphocytic leukaemia. Immunotherapy with IVIG in diseases of autoimmune character such as acute and chronic demyelinating neuropathy has recently shown promising results and encouraging reports have been published in the treatment of severe, steroid-dependent asthma, juvenile chronic arthritis and systemic vasculitis and dermatomyositis where IVIG possibly has a favourable immunomodulating effect on the patient's immune response. Future treatment will probably consist of polyvalent immunoglobulins as well as monoclonal or recombinant monovalent antibodies.


Problems and perspectives of the Na-pump reconstitution. The review deals with basic criteria of reconstruction approach to the study of membrane functions of the cell. Possible methods of reconstruction for solution of the problems of active ion transport have been demonstrated on the example of Na, K-ATPase. The alternative ways of the study which open molecular mechanisms of work of a system of active transport of Na+ and K+ ions through the cell membrane have been analyzed.


[Transforming growth factor beta. A potent multifunctional growth factor for normal and malignant cells]. The polypeptide growth factor transforming growth factor-beta (TGF-beta) is a multifunctional regulator of basic cellular functions: proliferation, differentiation, cell adhesion and interactions with the extracellular matrix. TGF-beta is part of a regulatory network of which our knowledge is still incomplete, together with other substances such as steroid hormones, oncogene products and integrins. Five isoforms for TGF-beta and five different TGF-beta receptors have been described. TGF-beta exhibits an antiproliferative effect in vitro and in vivo on many cells of epthelial, myeloid, lymphoid and mesenchymal origin together with a growth-stimulating effect on various cells like endothelial cells and epidermal keratinocytes. Production of TGF-beta and receptors for TGF-beta has been found in many cell types, both normal and malignant. Nevertheless the amount of in vivo data is too limited to identify possibilities for therapeutic intervention in the physiological and patophysiological functions of TGF-beta.


[Wilm's tumor 1992. State of research and results of current therapeutic concepts]. Wilms' tumor is the most frequent and most important pediatric tumor in urologic oncology. In recent years the prognosis of Wilms' tumor has improved markedly and a cure rate of more than 80% can be achieved by means of standardized therapy protocols such as those established by the National Wilms' Tumor Study (NWTS), the Société Internationale d'Oncologie Pédiatrique (SIOP), and the German Society of Pediatric Oncology (GPO). However, since the number of long-term survivors is now expected to increase, serious long-term complications must be taken into account, especially after radiation therapy, and treatment modalities must be modified with due consideration for toxicity and late effects of treatment. Refinement of treatment protocols is therefore the main aim to two studies, SIOP-9/GPO and NWTS-4. In Germany, children with Wilms' tumor are now treated according to the SIOP-9/GPO protocol including preoperative chemotherapy. Preoperative chemotherapy can reduce tumor volume markedly, leading to a significantly higher proportion of children with stage I/II tumors at the time of surgery. Thus, postoperative chemotherapy can be reduced and radiation therapy avoided in children in whom stage III tumors would other wise have to be expected. Radiation therapy of pulmonary metastases can be restricted to children who have not responded to prior chemotherapy, whereas in others it seems tumor-free survival can be achieved by extirpation of the remaining pulmonary metastases alone following chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)


[Functional activity of tissue Na,K-ATPase in health and in pathology]. The review deals with two basic possibilities of regulation of ion-transporting activity. The first possibility is connected with the changes in the number of working molecules of Na, K-ATP-ase and the second one with the change in the number of turns of active molecules of the pump.


Characterisation of an infectious bronchitis virus isolated from vaccinated broiler breeder flocks. Four apparently serologically closely related isolates of infectious bronchitis virus were obtained from two flocks of vaccinated broiler breeders, one mile apart, which were experiencing increased mortality and decreases in egg production. The isolates were serologically distinct from isolates previously described and capable of causing characteristic infectious bronchitis-like respiratory infection in young chicks. In one experiment, the H120 vaccine strain of the virus did not protect the trachea against challenge with the new isolates 21 days later.


[Changes in the content of rat brain polyphosphoinositides after exposure to high partial pressures of helium and nitrogen]. Effect of the medium with high partial pressure of helium and nitrogen on the content of di- and triphosphinositides in the rat brain great hemispheres. The stay of the rats in helium-oxygen mixture under the pressure of 40 kg/cm2 for 1 h is accompanied by the true decrease in the content of the both components of polyphosphoinositides whose value does not depend on the decompression conditions. Nitrogen-oxygen mixture under the pressure of 15 and 25 kgf/cm2 also evokes a decrease of the content of di- and triphosphoinositides. The character of reduction of the content of the both components for 4 h after the stay of the rats under the pressure of 25 kgf/cm2 depends on the decompression conditions.


Medical treatment of retinal infections in patients with AIDS. The Council on Scientific Affairs of the California Medical Association presents the following inventory of items of progress in ophthalmology. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, and scholars to stay abreast of these items of progress in ophthalmology that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another. The items of progress listed below were selected by the Advisory Panel to the Section on Ophthalmology of the California Medical Association, and the summaries were prepared under its direction.


Epidemiology and control of Japanese encephalitis. Japanese encephalitis (JE) remains endemo-epidemic in several countries in East, South-East and South Asia. The disease has been under control in Japan since the 1970s owing to mass immunization using mouse-brain-derived inactivated vaccine and to reduced vector mosquito populations. The vector density which was once reduced by wide spraying of insecticides in rice fields showed an increasing trend after the 1980s as a result of mosquito resistance. In the Republic of Korea, the number of JE cases showed a significant decrease after 1983 also because of mass immunization using mouse-brain-derived vaccine. On the other hand, large outbreaks of JE continued to occur in China, Viet Nam, Thailand, India, Nepal and Sri Lanka. In China, a hamster-kidney cell-derived vaccine was developed and used for human immunization. Besides human JE, the fatal outcome of equine JE is an economic problem in China. Current JE vaccine derived from mouse brain is highly purified and its safety and efficacy have been proved by field-tests as well as laboratory experiments. In spite of slight antigenic differences among JE virus isolates, JE vaccine produced by a classical Nakayama strain was effective in preventing overt JE in a field study in Thailand. The technology of mouse-brain-derived inactivated JE vaccine production was transferred from Japan to India, Thailand and Viet Nam. The production of JE vaccine in these countries is still on a pilot scale and insufficient for mass-immunization of susceptible target populations.(ABSTRACT TRUNCATED AT 250 WORDS)


[The effect of soy bran on the bile acid spectrum of patients with cholelithiasis]. Thirty females aged 21-57 with cholelithiasis in the physicochemical stage were put on a diet including soya bran. Bile acids were assayed in the duodenal portion B by gas-liquid chromatography. A pre- and posttreatment bile spectrum analysis indicated that before the dietetics chenodeoxycholic acid concentration and mean total of bile acids were markedly lower than control values. The diet enriched with food fibers promoted normalization of the above parameters.


Distribution of bovine virus diarrhoea viral antigens in the central nervous system of cattle with various congenital manifestations. Distribution of bovine viral diarrhoea virus (BVDV) antigens in the central nervous system (CNS) of 26 cattle persistently BVDV infected, 11 cattle with mucosal disease (MD), and 32 calves with congenital brain malformations was studied using monoclonal antibodies against BVDV epitopes. In persistently infected cattle and in cattle with MD, a widespread infection of neurons was present. Predilection sites for BVDV antigens were the cerebral cortex and the hippocampus. In calves with congenital encephalopathies, viral antigen-containing neurons could only be detected in the CNS of four animals. From the topographical distribution of BVDV antigens in these four postnatal cases with end-stage lesions, no conclusions could be drawn concerning the pathogenesis of BVDV-induced encephalopathies.


Serological evidence of equine herpesvirus type 1 (EHV-1) activity in polo horses in Nigeria. Serological evidence of Equine Herpes virus type 1 (EHV-1) activity in Polo horses in Nigeria is reported for the first time. Eighty-two percent of horses tested with known antigen had precipitating antibodies to EHV-1 while 43% of sera tested against antigen prepared from nasal discharges were positive suggesting that the virus was being excreted in the nasal discharges and probably acting as a source of infection for incontact animals as occurs in on-going acute infections. The result of this study indicates a high prevalence of EHV-1 activity among Polo horses in Nigeria and demonstrates the ubiquitous distribution of the virus in a country that has not been previously investigated.


[Ultrasonic destruction of the spinal trigeminal nucleus in the deafferentation orofacial pain syndrome]. Ultrasonic destruction of the trigeminal spinal nucleus was conducted in 12 patients with the deafferentation orofacial pain syndrome. The etiological factors and clinical manifestations of the deafferentation syndrome are analysed. The surgical techniques of destruction of the trigeminal spinal nucleus and the principles of intraoperative electrophysiological control are described. The length of the nucleus destruction and the clinical effect of the surgical intervention are compared. To relieve pain and dysesthesia in the peri- and intraoral areas the terminal nucleus must be destroyed at the level of the obex of the fourth ventricle.


[The biopsy of brain structures in patients with extrapyramidal hyperkinesia]. A new device for brain biopsy is presented, the techniques and method of biopsy of brain structures are described which allow full value biopsy material to be obtained from any area of the brain with minimal risk for the patient and high accuracy of hitting the aim. Biopsy of the cerebral and cerebellar cortex, and thalamic and cerebellar nuclei was conducted in 82 patients during stereotaxic operations (34 patients with infantile cerebral paralysis, 8 with torsion dystonia, 8 with spasmodic torticollis). Stereotaxic biopsy of brain tumors of various localization was also performed in 20 patients.


Patterns of internal echoes in lymph nodes in the diagnosis of lung cancer metastasis. In 1989-90, all 37 lung cancer patients scheduled for surgery underwent transesophageal endoscopic ultrasonography (EUS) for pre-operative detection of hilar and mediastinal lymph node metastases. An electronic ultrasonic fiberscope with a linear array (EPB-503-FS, Machida-Toshiba) was used. Of 380 nodes surgically removed and that could have been detected by EUS, the detection rates for histologically metastatic and non-metastatic nodes were 65% (33 of 51) and 44% (144 of 329), respectively (p less than 0.01). Metastatic nodes were detected readily in every lymph node site, especially subaortic and subcarinal. Non-metastatic nodes were detected at low rates, especially in the superior mediastinum, paratracheal, and tracheobronchial locations. For greater long or short axes of the detected nodes, or for rounder nodes, the metastasis rate was higher. Detected nodes were classified into six types by their internal echo patterns; three were rarely metastatic (called "negative") and the other three were often metastatic (called "positive"). Of the "negative" nodes histologically proved to be metastatic, metastasis was often diffuse. The "positive" nodes found to be metastatic tended to have one of two patterns of internal echoes when invasion was diffuse and a third pattern when it was localized. In an examination of the diagnostic usefulness of EUS, we made more correct diagnoses from the internal echo pattern than by reference to either the long or short axis alone. The short axes, node shape, and internal echoes were examined by Hayashi's second method of quantification. The sensitivity, specificity, and accuracy of the diagnoses were 85%, 84%, and 84%, respectively, superior to those by computed tomography done of the same patients.


[The control of the regulatory system of intracranial blood circulation in neurosurgical patients]. The authors suggest the principles of evaluation of the condition of the system regulating the circulatory provision of cerebral physical and chemical homeostasis, as well as a measurement complex and a set of instrumentally recorded values for control over the cerebral arteries' and veins' response to unified loads of physical and chemical nature in patients with neurosurgical pathology. The scientific and practical significance of such an approach to evaluation of cerebral blood circulation is reasoned by the results of accumulated experience in controlling the activity of some regulations of circulatory provision of the brain in healthy females and males differing in age and in 114 patients with brain tumors.