Steady-state and dynamic properties of cardiac sodium-calcium exchange. Ion and voltage dependencies of the transport cycle. Ion and voltage dependencies of sodium-calcium exchange current were studied in giant membrane patches from guinea pig ventricular cells after deregulation of the exchanger with chymotrypsin. (a) Under zero-trans conditions, the half-maximum concentration (Kh) of cytoplasmic calcium (Cai) for activation of the isolated inward exchange current decreased as the extracellular sodium (Nao) concentration was decreased. The Kh of cytoplasmic sodium (Nai) for activation of the isolated outward exchange current decreased as the extracellular calcium (Cao) concentration was decreased. (b) The current-voltage (I-V) relation of the outward exchange current with saturating concentrations of Nai and Cao had a shallow slope (twofold change in approximately 100 mV) and a slight saturation tendency at very positive potentials. The outward current gained in steepness as the Nai concentration was decreased, such that the Kh for Nai decreased with depolarization. The decrease of Kh for Nai with depolarization was well described by a Boltzmann equation (e alpha.Em/26.6) with a slope (alpha) of -0.06. (c) Voltage dependence of the outward current was lost as the Cao concentration was decreased, and the Kh for Cao increased upon depolarization with a Boltzmann slope of 0.26. (d) The I-V relation of the inward exchange current, under zero-trans conditions, was also almost linear (twofold change in approximately 100 mV) and showed some saturation tendency with hyperpolarization as the Cai concentration was decreased. The Kh for Cai decreased with depolarization (Boltzmann slope, -0.10). Voltage dependence of the inward current was decreased in the presence of a high (300 mM) Nao concentration. (e) In the presence of both Na and Ca on both membrane sides, the I-V relations with saturating Nai show sigmoidal shape and clear saturation at positive potentials. Measured reversal potentials were close to the equilibrium potential expected for a 3 Na to 1 Ca exchange. (f) Nai and Cai interacted competitively with respect to the outward current, but in a mixed competitive-noncompetitive fashion with respect to the inward current. (g) Cai inhibited the outward exchange current in a voltage-dependent manner. The half-effective concentration for inhibition (Ki) by Cai increased upon depolarization with a Boltzmann slope of 0.32 in 25 mM Nai and 0.20 in 100 mM Nai. (h) Nai also inhibited the inward exchange current voltage dependently. The Ki decreased upon depolarization (Boltzmann slope, -0.11 at 3 microM Cai and -0.10 at 1.08 mM Cai).(ABSTRACT TRUNCATED AT 400 WORDS)


Image analysis of neuropil threads in Alzheimer's, Pick's, diffuse Lewy body disease and in progressive supranuclear palsy. Neuropil threads (NT) in the middle temporal gyrus (MTG) were quantitated by computerized image analysis from five patients each with Alzheimer's disease (AD), Pick's disease (PD), and diffuse Lewy body disease (DLBD), four patients with progressive supranuclear palsy (PSP), and five cognitively normal control subjects (24 patients total). All disease groups met clinical and pathological criteria for their respective diseases. The DLBD subjects did not have pathological features of AD. Using the Gallyas silver method, the percentage of cortical area occupied by NT was calculated for each case examined and compiled for each group. Intergroup comparison revealed the percentage of cortical area occupied by NT as follows: AD, 6.87%; PSP, 1.12%; PD, 0.37%; DLBD, 0.04%; control 0.02%. The evaluation disclosed a significance level of p < 0.0001 when AD was compared to control, PD and DLBD cases and a p < 0.001 when compared to PSP. There was no statistically significant difference between control-DLBD, control-PD, control-PSP, DLBD-PSP, PD-PSP, or PD-DLBD cases (p > 0.05). These data indicate the density of neocortical threads is much greater in AD than in other dementing disorders. It also suggests that NT are not related to the intellectual decline in PD, DLBD, and PSP.


Epstein-Barr virus (EBV) and Hodgkin's disease in children: incidence of EBV latent membrane protein in malignant cells. Previous studies have detected EBV DNA by Southern blotting or in situ hybridization in biopsy material from up to 30 per cent of adult cases of Hodgkin's disease. Here we have used monoclonal antibodies specific for the EBV latent membrane protein LMP1 to examine archival material from children with Hodgkin's disease. Material from 74 cases (54 males and 20 females) was examined and 37 (30 males and 7 females) were classified as LMP1-positive in the malignant cells. LMP1 positivity was present in 4/13 (31 per cent) of lymphocyte predominant, 14/36 (39 per cent) of nodular sclerosis, 17/20 (85 per cent) of mixed cellularity, 1/2 (50 per cent) of lymphocyte depletion, and 1/3 (33 per cent) of unclassified subtypes. The positive cases by clinical stage were I 9/22 (41 per cent), II 9/20 (45 per cent), III 11/24 (46 per cent), and IV 8/8 (100 per cent). LMP1 positivity was present in 2/5 (40 per cent) children aged less than 5 years, 12/27 (44 per cent) aged 5-10 years, and 23/42 (48 per cent) aged between 10 and 15 years. The association between EBV and Hodgkin's disease in children thus appeared to be more frequent in patients with mixed cellularity and advanced disease, but examples of EBV-positive tumours were found in all histological subtypes, stages, and ages. Stepwise discriminant function analysis showed that clinical stage IV and mixed cellularity histology are independently associated with LMP1 positivity. These observations indicate that Hodgkin's disease in children is at least as strongly linked to EBV as is the disease in adults.


Expression of the p53 protein in a spectrum of astrocytic tumours. Many human cancers are characterized by mutations of p53, a nuclear phosphoprotein which controls elements of the cell cycle. Turnover of p53 in normal cells is rapid, and the minute quantities of protein that are usually present are not detected by immunocytochemical methods. Mutations of the p53 gene in tumour cells are associated with a slower turnover and subsequent accumulation of the protein in both nucleus and cytoplasm. Genetic abnormalities of the short arm of chromosome 17, which is the site of the p53 gene locus, are a feature of astrocytic tumours. Using a panel of five antibodies to p53 and a standard immunocytochemical method, we found detectable quantities of p53 in the cells of 3/16 diffuse astrocytomas, 8/14 anaplastic astrocytomas, and 24/34 glioblastoma multiforme. Progression of one patient's tumour from a diffuse to an anaplastic astrocytoma was characterized by the accumulation of p53. The more malignant histological features of anaplastic astrocytoma and glioblastoma multiforme appear to be reflected by a greater incidence of p53 accumulation.


Calcium channel blockers in vivo inhibit serotonin N-acetyltransferase (NAT) activity in chicken retina stimulated by darkness and not by agents elevating intracellular cyclic AMP level. The molecular mechanism underlying the role of calcium influx in the regulation of retinal serotonin N-acetyltransferase (NAT) activity was studied in vivo in chickens. Systemic administration of organic antagonists of voltage-sensitive calcium channels (VSCC), i.e., nimodipine and nifedipine, resulted in a marked suppression of the nocturnal increase of NAT activity in chicken retina. In contrast, NAT activity stimulated by nonhydrolysable analogs of cyclic AMP (dibutyryl-cyclic AMP and 8-bromo-cyclic AMP), forskolin, a direct activator of adenylate cyclase, and by phosphodiesterase inhibitors (aminophylline and 3-isobutyl-1-methylxanthine), was not significantly affected by various tested VSCC antagonists. The inhibitory effect of nimodipine on the dark-dependent increase in NAT activity of chicken retina was abolished by Bay K 8644, a selective VSCC agonist. The results presented in this paper indicate an important role of calcium influx through L-type of VSCC in the induction of NAT activity in chicken retina, and suggest that a requirement of calcium ions in the process of NAT induction in the retina may be primarily at the level of cyclic AMP production.


Diurnal changes in cyclic nucleotide response to pineal indoles in murine mammary glands. The aim of this study was to determine whether pineal indoles affect cyclic nucleotide levels in mammary gland slices of BALB/c adult mice. Melatonin at 0.1 nM-10 microM concentrations decreased cAMP and augmented cGMP concentration in murine mammary gland slices in the presence of a phosphodiesterase inhibitor (1 mM theophylline), an index of cyclic nucleotide synthesis. Melatonin-induced changes in cyclic nucleotide levels were significantly larger at the end of the light period (2000) than in the morning (at 1000). Indole-induced inhibition of cyclic AMP levels by mammary slices exhibited the following order of potency: 5-methoxytryptamine > melatonin > or = 6-hydroxymelatonin > serotonin, N-acetylserotonin > 5-hydroxytryptophol. The order of potency for indole-induced augmentation of cyclic GMP levels was: 5-methoxytryptamine > melatonin > 6-hydroxymelatonin > serotonin, N-acetylserotonin, 5-hydroxytryptophol. When melatonin or 5-methoxytryptamine (10 nM) were examined for their effects on cAMP and cGMP levels in mammary glands of mice killed at six different time intervals during the 24-hr cycle, the activity was maximal during night. The data demonstrate that 5-methoxytryptamine and melatonin decreased cAMP and increased cGMP levels in mammary gland slices. Methoxyindole-induced changes in cyclic nucleotide synthesis in murine mammary glands exhibit the time-dependency known to occur in several other melatonin-influenced responses.


The presence and actions of opioid receptors in bovine pineal gland. The mammalian pineal gland and its main hormone, melatonin, working in conjunction with the hypothalamic suprachiasmatic nuclei, synchronize circadian rhythm and hence refine numerous physiological and biochemical parameters. An interaction among melatonin, opioids, and analgesia has been suspected for many years, since during nighttime, when the level of melatonin is high, the mammals are less sensitive to pain. In studying this phenomenon further, we have identified a single population of opioid receptors in the bovine pineal gland using [3H]-diprenorphine and other ligands. The receptors have a dissociation equilibrium constant (Kd) of 1.36 +/- 0.31 nM and a density (Bmax) of 17.93 +/- 5.22 fmol/mg protein. In competitive experiments, the concentration of drugs required to inhibit 50% of the [3H]-diprenorphine binding (IC50) in descending order of potency was found to be naltrexone > fentanyl > naloxone > nalbuphine > morphine > nalorphine > DAGO > dynorphin > metenkephalin. In order to delineate the function of the opioid system in the pineal gland, the effects of both opioid receptor agonists and antagonists on the basal activity of N-acetyltransferase were examined in the bovine pineal explants in culture. Morphine, an opioid receptor agonist, increased significantly the activity of N-acetyltransferase in a dose-dependent fashion. In addition, the stimulatory effect of morphine was inhibited by naloxone, an opioid receptor antagonist. The results of these studies indicate the existence of pineal opioid receptors, which play a pivotal role in the synthesis of melatonin and its action in synchronizing pineal events.


[Studies on cardiac ingredients of plants. X. Preparation of nitrates of tetrahydroproscillaridin and their pharmacological activities]. To reduce the vascular contracting effect of the hydrogenated cardiac glycosides, 20-(R)- and 20-(S)-tetrahydroproscillaridins (THPs, 1a, 1b), and to extend the concentration-dependent range, mono- and dinitrates of THPs were prepared. The pharmacological activities of the nitrates of THP were evaluated by use of isolated guinea-pig papillary muscle preparations and Na+,K(+)-adenosine triphosphatase preparations from dog kidney. Furthermore, the effect for smooth muscle was examined using the helical strips isolated from 13-week-old spontaneously hypertensive rat. The positive inotropic effects of mononitrates (11a, 11b, 2a, 2b, 8a, and 8b) were more potent than those of THPs. Nitration of the sugar moiety in THPs resulted in a vascular relaxing effect unobserved in the case of THPs.


[Synthesis and benzodiazepine receptor binding studies of pyridazino[3,4-b]indoles]. A series of methyl 9H-pyridazino[3,4-b]indole-3-carboxylates and related compounds were synthesized using a Diels-Alder reaction of methyl 3-(1H-indol-3-yl)-2-propenoates and dibenzyl azodicarboxylate. Several compounds were found to have high affinity for the benzodiazepine receptor. Their structure-activity relationships are discussed.


Pipette GTP is essential for receptor-mediated regulation of Cl- current in dialysed myocytes from guinea-pig ventricle. 1. Wide-tipped, low-resistance (approximately 1 M omega) pipettes were used to record the whole-cell Cl- current activated by cAMP-dependent protein kinase (PKA) in guinea-pig ventricular myocytes internally dialysed with or without GTP. Without GTP in the pipette, the response to 1 microM-isoprenaline declined with time and eventually disappeared, usually within approximately 20 min of rupturing the membrane and beginning cell dialysis. 2. This rundown of the isoprenaline response occurred more quickly with wider, lower-resistance pipette tips. 3. After complete rundown of the isoprenaline response, histamine (10 microM), another agonist known to elicit the Cl- current, also had no effect, but extracellular forskolin (1 microM) or intrapipette cAMP (1 mM) could still readily elicit the Cl- current. 4. In contrast, with 100 microM-GTP in the pipette, the response to 1 microM-isoprenaline was well maintained for periods greater than 20 min. But, if GTP was then withdrawn from the pipette, a rundown of the isoprenaline response was seen comparable to that in the experiments begun with GTP-free pipette solution. Moreover, in experiments begun without pipette GTP, the addition of 100 microM-GTP to the pipette solution, after the response to isoprenaline had disappeared, was able to restore that Cl- current response. 5. With GTP in the pipette, the forskolin-induced Cl- current could be suppressed by concurrent exposure to carbachol (10 microM). That inhibition was not seen in myocytes pretreated with pertussis toxin. In untreated myocytes dialysed with GTP-free pipette solution, after disappearance of the isoprenaline response, the muscarinic receptor-mediated inhibition was itself abolished. 6. We confirm that both beta-adrenoceptor-mediated activation of the Cl- current by isoprenaline, and muscarinic receptor-mediated inhibition of the forskolin-induced Cl- current, are mediated by G proteins, and conclude that the disappearance of both receptor-mediated responses during whole-cell recording with GTP-free pipette solution reflects the fall of cellular [GTP] below the level required to maintain G protein-dependent signal transduction.


Intracellular pH and its relationship to regulation of ion transport in normal and cystic fibrosis human nasal epithelia. 1. Intracellular pH (pHi) of cultured human airway epithelial cells from normal and cystic fibrosis (CF) subjects were measured with double-barrelled pH-sensitive liquid exchanger microelectrodes. The cells, which were grown to confluence on a permeable collagen matrix support, were mounted in a modified miniature Ussing chamber. All studies were conducted under open circuit conditions. Values are given as means +/- S.E.M. and n refers to the number of preparations. 2. Normal preparations (n = 15) were characterized by a transepithelial potential difference (Vt) of -18 +/- 2 mV, an apical membrane potential (Va) of -19 +/- 2 mV, a basolateral membrane potential (Vb) of -37 +/- 2 mV, a transepithelial resistance (Rt) of 253 +/- 15 omega cm2, a fractional apical membrane resistance (fRa) of 0.40 +/- 0.04 and an equivalent short circuit current (Ieq) of -73 +/- 7 microA cm-2. 3. CF preparations (n = 13) were characterized by a Vt of -46 +/- 7 mV, a Va of 3 +/- 5 mV, a Vb of -43 +/- 3 mV, Rt of 373 +/- 47 omega cm2, fRa of 0.44 +/- 0.04 and an Ieq of -130 +/- 16 microA cm-2. All parameters except Vb and fRa were significantly different (P < 0.025) from those of normal preparations. 4. Despite large differences in electrochemical driving force for proton flow across the apical cell membranes between normal and CF preparations (-4 +/- 3 mV and 20 +/- 7 mV, respectively), pHi was similar (7.15 +/- 0.02 and 7.11 +/- 0.05, respectively). The driving force across the basolateral membrane was similar in normal and CF preparations (22 +/- 3 and 26 +/- 3 mV, respectively). 5. Intracellular alkalinization achieved by removal of CO2 from the luminal Ringer solution or by luminal ammonium prepulse led to stimulation of Ieq in both normal (from -58 to -70 microA cm-2, n = 4; P < 0.05) and CF (from -144 to -163 microA cm-2, n = 4; P < 0.005) preparations. The increase in Ieq was associated with a reduction of Rt, increase in fRa, and hyperpolarization of Vb. All changes in bioelectric properties in response to intracellular alkalinization were fully reversible. 6. Intracellular acidification achieved by serosal ammonium prepulse led to marked reductions of Ieq in both normal (from -95 to -31 microA cm-2, n = 6; P < 0.05) and CF (from -111 to -67 microA cm-2, n = 7; P < 0.005) preparations.(ABSTRACT TRUNCATED AT 400 WORDS)


The peptide CGRP increases a high-threshold Ca2+ current in rat nodose neurones via a pertussis toxin-sensitive pathway. 1. The whole-cell variation of the patch clamp technique was used to study the effect of calcitonin gene-related peptide (CGRP) on voltage-gated calcium currents in acutely dissociated rat nodose ganglion neurones and to determine if its effects were mediated via a guanine nucleotide binding (G) protein. 2. Both low- and high-threshold calcium current components were present in nodose ganglion neurones. CGRP had no effect on the isolated low-threshold current component. However, CGRP (1-1000 nM, ED50 = 50 nM) caused a concentration-dependent increase in high-threshold calcium currents. CGRP (1 microM) increased the peak of these calcium currents 21 +/- 4% over controls. 3. CGRP enhanced a transient high-threshold calcium current evoked from a holding potential of -80 mV but did not affect the slowly inactivating high-threshold current evoked from -40 mV. Multiple high-threshold calcium currents have been reported in sensory neurones. We cannot state unequivocally which high-threshold calcium current component was enhanced by CGRP. However, based on the observation that CGRP increased a transient but not the slowly inactivating high-threshold calcium current, we believe the peptide enhanced primarily the N-type calcium current component. 4. CGRP increased the maximal peak current and caused a modest negative shift of < or = 10 mV in the peak of the current-voltage (I-V) relation in three of six neurones. In the remaining three neurones the peptide increased the maximal peak current without a detectable shift in the peak of the I-V relation. 5. To determine if the CGRP-induced enhancement in calcium current was associated with an increase in calcium conductance, we studied the effect of the peptide on the instantaneous current-voltage (I-V) relation when currents were evoked at a clamp potential (Vc) of +30 mV, positive to the observed maximal current (Vc = 0 to +10 mV). CGRP increased the maximal conductance 23 +/- 4%. 6. The enhancement of calcium current by CGRP was not due to a shift in the voltage dependency of steady-state inactivation of the calcium channels. The stimulatory effect of CGRP on calcium current was evaluated by evoking currents from different holding potentials (Vh) at the same Vc (+10 mV). CGRP-induced increases in calcium currents were similar over the range of (Vh) from -60 to -110 mV, suggesting that the peptide did not alter voltage-dependent steady-state inactivation.(ABSTRACT TRUNCATED AT 400 WORDS)


Vestibular-evoked postural reactions in man and modulation of transmission in spinal reflex pathways. 1. The effects of galvanic stimulation of the vestibular apparatus (with electrodes on the mastoid processes) have been studied in standing human subjects. With the head turned to one side, subjects swayed towards the anode. 2. Forwards sway was preceded by electromyographic (EMG) activity in quadriceps and tibialis anterior muscles. Backwards sway was preceded by EMG activity in soleus and hamstring muscles. 3. Using the method of H reflex conditioning, forward sway was found to be preceded by inhibition of soleus motoneurones. 4. Interaction between the vestibular-evoked inhibition of soleus motoneurones preceding forwards sway and peripheral reflex inhibition was examined by a spatial facilitation method. 5. Interaction was found between vestibular-evoked inhibition and Ia reciprocal, group I non-reciprocal and group Ia-Ia presynaptic inhibitory pathways. It is concluded that vestibular signals converge on spinal interneurones subserving these inhibitory actions. 6. A 'decoupling' of soleus motoneurons and soleus-coupled Renshaw cells was found in the period of soleus activation preceding backwards sway.


Cortical modulation of transmission in spinal reflex pathways of man. 1. The motor actions in the lower limb of transcranial electrical stimulation of the motor cortex have been studied in sitting human subjects. 2. Cortical stimulation induced a short latency inhibition of H reflexes evoked in soleus motoneurones both at rest and during small voluntary contractions of soleus. 3. Spatial interaction between cortical inhibition of soleus motoneurons and inhibition evoked through identified spinal reflex machinery was investigated. 4. Interactions were found between cortically evoked inhibition and spinal Ia reciprocal inhibition, group I non-reciprocal inhibition and higher threshold components of longer latency reciprocal inhibition (D1 and D2 inhibitions). 5. Interactions were facilitatory when cortical and spinal inhibitory actions were weak and reversed to occlusion when both actions were strong. 6. It is concluded that the corticospinal pathway converges on the interneurones which subserve Ia reciprocal, group I non-reciprocal, D1 and D2 inhibition of soleus motoneurones. 7. No significant interaction was found under the present experimental conditions between cortical stimulation and group Ia-Ia presynaptic inhibition of soleus afferents. 8. The statistical significance of spatial interactions observed with H reflex conditioning was investigated using a control experiment.


A change from HCO3(-)-CO2- to hepes-buffered medium modifies membrane properties of rat CA1 pyramidal neurones in vitro. 1. Intracellular recordings were obtained from CA1 pyramidal neurones in rat hippocampal slices. Perfusion with a HCO3(-)-CO2-free, HEPES-buffered medium at pH 7.4 produced a wide variety of reversible effects on neuronal excitability, compared to responses obtained under standard (21 mM-HCO3-, 5% CO2, pH 7.4) conditions. 2. Introduction of HCO3(-)-CO2-free medium most commonly elicited, within 5-20 min, a fall in resting membrane potential (Vm), a rise in threshold for Na(+)-dependent action potential generation, and a reduction in input resistance. Anomalous inward rectification in the hyperpolarizing direction and subthreshold inward rectification were commonly reduced in HEPES-buffered medium. More prolonged exposure (> or = 25 min) to HCO3(-)-CO2-free medium produced, on occasion, Na+ spike inactivation. 3. The amplitudes of the fast and medium after-hyperpolarizations (AHPs) following a single depolarizing current-evoked action potential were attenuated during perfusion with HEPES-buffered medium at pH 7.4, as was the composite AHP following a train of action potentials. 4. Perfusion with HEPES-buffered medium at pH 7.4 reduced the degree of spike frequency adaptation and abolished depolarizing current-evoked burst-firing behaviour when this was present under standard conditions. 5. In tetrodotoxin (TTX)- and tetraethylammonium (TEA)-poisoned neurones, perfusion with HCO3(-)-CO2-free medium at pH 7.4 slightly raised the threshold for activation of Ca(2+)-dependent potentials and slightly reduced their duration, compared to responses obtained in HCO3(-)-CO2-buffered medium at the same pH. The AHP following the Ca2+ spike was, however, markedly attenuated. 6. Perfusion with a low-pH HCO3(-)-CO2-buffered medium (7 mM-HCO3-, 5% CO2, pH 6.9) produced changes qualitatively similar to those observed during perfusion with HEPES-buffered medium at pH 7.4. Raising the pH of the HEPES-buffered medium to 7.8 or 7.9 reversed inconsistently and then only in part the changes noted on the transition from a HCO3(-)-CO2- to a HEPES-buffered medium at the same pH (7.4). 7. The effects noted are unlikely to be due to a direct action of HEPES itself on neuronal membrane conductances. Rather, I suggest that they are likely to be caused by intracellular acidosis consequent upon the omission of HCO3- and CO2 from the extracellular medium.


Multiple kinetic components of sodium channel inactivation in rabbit Schwann cells. 1. We have studied the kinetics of inactivation of sodium currents evoked in Schwann cells from neonatal and adult rabbits with patch-clamp recording techniques. The decay both of whole-cell currents and of ensemble currents obtained from outside-out patches was reasonably well-described by single exponential fits which gave values for the time constant, tau h, similar to those found for such currents in nerve (about 0.5 ms at 0 mV). Although inclusion of an additional exponential component usually improved the fits to the decay of these currents, the relative amplitude of the slower component (time constant 3-6 ms) was always small. 2. The time course of recovery from steady-state inactivation clearly consisted of two exponential components. At -120 mV, recovery from steady-state inactivation at -50 mV consisted of a fast component with a time constant of 2.2 +/- 0.2 ms and a much slower component with a time constant of 1.2 +/- 0.2 s (n = 9). The relative amplitude of the slow component (expressed as a fraction of the sodium current when inactivation was removed completely) was 0.56 +/- 0.03. The corresponding amplitudes of the slow component when similar experiments were done from holding potentials of 0 and -70 mV were 0.80 +/- 0.04 and 0.36 +/- 0.03, respectively (n = 5 and 8). 3. The onset of steady-state inactivation also followed a bi-exponential time course. The time constant of the slower component was similar at each potential examined (0, -50 and -70 mV), being 6-7 s. The relative amplitude of the slow component of onset depended on membrane potential, and it was similar (at each potential examined) to the corresponding amplitude of the slow component of recovery. 4. The inclusion of 40 mM-iodate ions in the pipette solution slowed the decay of whole-cell sodium currents, as did the extracellular application of venom (10 micrograms ml-1) from the scorpion Leiurus quinquestriatus. Prolonged exposure of the cells to Leiurus venom appeared to increase the steady-state amount of slow inactivation. 5. Records of single-channel sodium currents tended to cluster into records which either did, or did not, contain openings. This apparently non-random behaviour depended on membrane potential, and on the frequency at which the test steps were repeated, in the way expected if it resulted from slow inactivation.(ABSTRACT TRUNCATED AT 400 WORDS)


Differential regulation of the nerve growth factor and brain-derived neurotrophic factor genes in L929 mouse fibroblasts. Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) are structurally related survival and differentiation factors for distinct sets of peripheral and central neurons. The regulation of NGF gene expression has been extensively studied in L929 mouse fibroblasts. L929 cells also express the BDNF gene. Northern blot hybridization analysis revealed 4 discrete BDNF mRNA species in L929 cells and rat hippocampus after induction of seizures with kainic acid. Serum as well as 12-O-tetradecanoyl phorbol-13-acetate (TPA) stimulated NGF and all 4 BDNF mRNAs in L929 cells. Treatment with both agents induced NGF mRNA to a much larger extent than the BDNF mRNAs. The induction of the BDNF mRNAs was rapid, with nearly maximal levels by 1 hr. In contrast, NGF mRNA induction occurred later and peaked at 4-6 hr. Both NGF and BDNF mRNA induction were inhibited by actinomycin D. Cycloheximide, on the other hand, inhibited only NGF but not BDNF mRNA induction. Corticosterone rapidly decreased NGF mRNA but not the BDNF mRNAs, and had no effect on seizure-induced NGF or BDNF mRNAs. Forskolin did not stimulate NGF or BDNF mRNAs. In contrast to NGF mRNA, forskolin did not interfere with the serum induction of BDNF mRNAs. These results demonstrate that 2 genes which encode closely related neurotrophic factors are differentially regulated in L929 cells. The molecular mechanisms which bring about this differential regulation remain to be elucidated.


[A case of small cell lung cancer occurring in a patient with pulmonary sarcoidosis]. A 62-year-old man was diagnosed as having sarcoidosis on the basis of uveitis, and the findings of bronchial alveolar lavage and transbronchial lung biopsy, in April 1988. He was admitted to hospital in September 1990, because of left hemiplegia. The chest X-ray film on admission revealed a new mass shadow in the left S6 and some increase of nodular shadows in both lung fields. A bronchial biopsy from the left B6 bronchus revealed small cell lung cancer. Although he was treated with whole brain irradiation and combination chemotherapy, he died of respiratory failure after three months. Speculations about the association between sarcoidosis and lung cancer have been made, but the mechanism is not understood, and their co-existence in the same patient is rare.


[An autopsy case of dermatomyositis associated with interstitial pneumonia probably due to cytomegalovirus infection]. An autopsy case of dermatomyositis (DM) associated with interstitial pneumonia probably due to cytomegalovirus infection is reported. After corticosteroid therapy for 1 month, a 79-year-old man with DM developed acute respiratory failure due to interstitial pneumonia and died in spite of intensive respiratory care. By polymerase chain reaction method (PCR), DNA of cytomegalovirus (CMV) was detected in the bronchoalveolar lavage fluid (BALF). CMV was also detected by the method of conventional virus culture from BALF. These findings suggested that initial infection or reactivation of CMV had occurred in the lungs. The autopsy specimen revealed the findings of interstitial pneumonia compatible with CMV pneumonitis, but without the presence of intranuclear inclusion bodies. Although the present case of interstitial pneumonia should not strictly be diagnosed as definite CMV pneumonitis without the presence of intranuclear inclusion bodies in the lung tissue, initial infection or reactivation of CMV in the lungs may have contributed to the pathogenesis of interstitial pneumonia. In other cases of collagen vascular disease associated with interstitial pneumonia, CMV or other viruses may contribute to the pathogenesis of interstitial pneumonia.


Treatment of coccidioidomycosis osteomyelitis with itraconazole in a horse. A brief report. Itraconazole, a tricyclic azole effective against a number of deep mycotic diseases, was used to treat a Quarter Horse filly with coccidioidomycosis. The horse was almost normal after 90 days of treatment. Five months after discontinuing itraconazole treatment, the filly had severe neck pain and neurologic signs from recurrence of coccidioidomycosis and was treated with itraconazole for an additional 6 months. Her clinical condition improved to almost normal and the filly has remained normal for 2 years. There was no evidence of drug toxicity.


[A case of small cell carcinoma of the lung with carcinomatous lymphangiosis-like shadow]. A 60-year-old man was admitted to our hospital on January 29, 1991 with dry cough, shortness of breath on exertion, appetite loss and abnormal shadows on chest X-ray. Chest X-ray on admission showed marked vascular shadows in both lung fields accompanied by left interlobar effusion. Chest CT showed thickening of vessels and bronchial walls with prominent interlobular septa in the subpleural regions. These findings suggested that the lesions were located in the peribronchial and perivascular interstitium and interlobular septa. Biopsy specimens of bronchial epithelium, lung tissue and right supraclavicular lymph nodes revealed small cell carcinoma (intermediate cell type). Because of the absence of lesions in other organs, the initial diagnosis was carcinomatous lymphangiosis of small cell carcinoma of the lung. However, the mild symptoms, normal arterial blood gas and good response to chemotherapy suggested the possibility of extensive small cell carcinoma of longitudinal spread type. Although small cell carcinoma of the lung is not a rare disease, this case suggests two possibilities. 1) Carcinomatous lymphangiosis of small cell carcinoma may have different symptoms, clinical course and prognosis from that of non-small cell carcinoma. 2) Carcinomatous lymphangiosis of small cell carcinoma may not be a clinical entity and in fact may simply represent extensive small cell carcinoma of longitudinal spread type.


Expression of Escherichia coli beta-galactosidase in Mycobacterium bovis BCG using an expression system isolated from Mycobacterium paratuberculosis which induced humoral and cellular immune responses. A promoter sequence, PAN, was isolated from Mycobacterium paratuberculosis and characterized. This promoter lies adjacent to, and outside, the 3' end of an IS900 insertion element. IS900 contains an open reading frame, ORF2, on the complementary strand which codes for the putative transposase of this insertion sequence. A DNA fragment containing PAN and part of ORF2 was fused to the lacZ gene and inserted into the replicative shuttle vector pRR3. Mycobacterium smegmatis and Mycobacterium bovis BCG (BCG) transformed with this plasmid exhibited beta-galactosidase activity. However, lacZ was only expressed in Escherichia coli under the control of PAN, when ORF2 was deleted. Immunization of mice with the recombinant M. bovis BCG expressing lacZ resulted in the induction of a high humoral and cellular response directed against beta-galactosidase. The PAN-ORF2 expression system may prove to be particularly useful for cloning and expression of heterologous genes in the BCG vaccine strain.


Effects of proteoglycan on hydroxyapatite formation under non-steady-state and pseudo-steady-state conditions. Addition of chondroitin sulfate (CS) or cartilage proteoglycan to metastable calcium phosphate solutions inhibits the formation of hydroxyapatite (HA). However, pre-equilibration of CS or proteoglycan with calcium prior to the addition of phosphate results in higher levels of HA precipitation compared to control solutions of identical calcium and phosphate activity. These findings indicate that the inhibition of HA formation by proteoglycans and CS is largely due to calcium binding. Further, its ability to bind calcium ions reversibly suggests that proteoglycan may act as a promoter, not an inhibitor, of calcification in cartilage.


Fulfilling the promise: implementing IAIMS at Georgetown University. Predictions are that the integration of multiple information systems of a medical center will change the way doctors work and practice medicine in the future. Several major steps must be taken by an institution to make this a reality. The IAIMS program sponsored by the NLM is designed to achieve integration of resources in the medical center environment. The purpose of the IAIMS project at Georgetown is to develop a medical decision support system by bringing together multiple sources of information that reside on disparate computers and different database systems. This immense and complex task is described in this paper from an organizational, academic and technical perspective. Georgetown is developing a Biotechnology and Biomedical Knowledge Network which includes several informational and clinical databases, a variety of scholar workstations, instruction on use of computers, a campus-wide network with local area network nodes and a modular approach to systems integration. The IAIMS project is spearheaded by the medical library which has enabled a broad body of medical center users to benefit directly from new, dynamic services.


[Involvement of the peripheral nervous system in HIV infection: electromyographic study and nerve conduction velocity]. Disorders of the peripheral nervous system occur at all stages of HIV1 infection. Acute and subacute inflammatory demyelinating polyneuropathies are mainly observed in otherwise asymptomatic HIV+ patients and in patients with ARC (AIDS-related complex): clinical and electrophysiological features are similar to those observed in Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP), but CSF examination usually shows pleocytosis, and an infiltration of the endoneurium and/or the epineurium is commonly seen in nerve biopsies. Mononeuropathy multiplex is a rare complication occurring in ARC-patients: electrophysiological studies are consistent with an axonopathy and nerve biopsies may show vasculitis. Distal predominantly sensory polyneuropathies are the most frequent peripheral neuropathies in HIV1 infection and are usually reported in patients with AIDS and severe immunosuppression: electrophysiological features are of an axonopathy with signs of acute denervation. Meningoradiculitis is observed at the late stages of the disease and is mainly due to a cytomegalovirus infection. On the other hand, systematic electrophysiological studies in HIV+ cases reveal a high percentage of abnormalities concerning sensory and less frequently motor nerve conduction velocities. The severity of this asymptomatic involvement of the peripheral nervous system seems to be related to the degree of the immunodeficiency. The mechanism of these peripheral neuropathies remains hypothetical in most cases.


Characterization of sequence changes in kinetoplast DNA maxicircles of drug-resistant Leishmania. We have compared kinetoplast DNA maxicircles of tunicamycin- and arsenite-resistant variants of repeatedly cloned Leishmania mexicana amazonensis showing DNA amplification with wild-type and arsenite-resistant variants of the same lineage that do not show DNA amplification. DNA restriction patterns and the degree of cross-hybridization between maxicircle DNA fragments of parasites displaying DNA amplification and those of parasites without amplification were examined. In addition, the nucleotide sequence of the cytochrome b (Cyb) gene from the coding region was compared between these two groups of parasites. Extensive changes were found in the nucleotide sequences and the amino acid sequences of the cytochrome gene of the maxicircles of variants with DNA amplification. The Cyb genes from both groups had much shorter open reading frames than the same gene from Leishmania tarentolae and Trypanosoma brucei. The simultaneous changes in maxicircles and minicircles of these variants suggest that they may confer the advantage of maintaining viable mitochondrial function under selective pressure.


The nucleotide sequence of the variable region in Trypanosoma brucei completes the sequence analysis of the maxicircle component of mitochondrial kinetoplast DNA. The nucleotide sequence of two non-contiguous DNA fragments of 4.0 and 2.2 kb, respectively, of the kinetoplast maxicircle of Trypanosoma brucei brucei EATRO strain 427 has been determined, completing the sequence analysis of the so-called variable region (see also de Vries et al., 1988, Mol. Biochem. Parasitol. 27, 71-82). Analysis of the entire 8-kb variable region sequence revealed the presence of a 5.2-kb cluster of imperfect, tandemly repeated sequences, flanked by DNA of unique sequence. Both repetitive and unique DNA evolve rapidly, but comparison to the closely related strain EATRO 164 indicated that the repetitive cluster is more prone to sequence and size divergence. The variable region is transcribed into RNAs of varying lengths but appears to be devoid of genes encoding mitochondrial proteins or tRNAs, as judged from computer analysis. Moreover, genes that could encode guide RNAs involved in producing the known edited mitochondrial mRNA sequences are also absent. The repetitive DNA cluster within this region consists of 14 blocks each containing one 130 bp repeat and a variable number of 19 bp repeats. A duplicated sequence was identified (5'-GGGGTTGGTGT) which proved to be identical to the eleven 5'-terminal residues of the universal minicircle dodecamer involved in initiation of leading strand synthesis. This suggests a role for these sequences in the initiation of maxicircle DNA replication. With the data presented in this report, the nucleotide sequence analysis of the 23016 bp maxicircle of T. brucei brucei EATRO strain 427 has been completed.


Chloride channels of skeletal muscle from developing, adult and aged rats are differently affected by enantiomers of 2-(p-chlorophenoxy) propionic acid. Enantiomers of 2-(p-chlorophenoxy) propionic acid, compounds acting specifically on chloride channels of adult rat skeletal muscles, have been tested on extensor digitorum longus (EDL) muscle of developing and aged rats, in an attempt to characterize the chloride channels responsible for the low chloride conductance (GCl) found in the above physiological situations. The S-(-) enantiomer, which produces a concentration-dependent inhibition of GCl in the adult EDL, is less effective in inhibiting GCl of EDL of either 2-3 weeks or 29 months old rats, particularly at low concentrations. The R-(+) isomer, which in the adult enhances GCl at low concentrations and blocks it at concentrations higher than 10 microM, lacks inhibitory action, enhancing GCl in both developing and aged EDL. At 30-40 days of age both the enantiomers produce almost the same effects exerted in adulthood. From these data we hypothesize that the low GCl found in EDL of developing and aged rats might be due not only to a lower number of conductive channels but also to the presence of a mixed population of isoforms of chloride channels having different pharmacological properties.


Pertussis toxin inhibits noradrenaline accumulation by bovine adrenal medullary chromaffin cells. Bovine adrenal medullary chromaffin cells maintained in tissue culture accumulated [3H]-noradrenaline by a high affinity, Na(+)-dependent, desipramine-sensitive process. The accumulation was linear with time (1-90 min) and had an apparent Km of 0.52 +/- 0.24 mumol/l and Vmax of 1.70 +/- 0.48 pmol/(10(5) cells.15 min). Pretreatment of the cells with the ADP-ribosylating agent pertussis toxin resulted in a reduction in the Vmax [0.81 +/- 0.39 pmol/(10(5)cells.15 min)] but no significant change in the apparent affinity (Km = 0.42 +/- 0.07 mumol/l). This inhibition of [3H]noradrenaline accumulation was distinct from that produced by the vesicular transport inhibitor reserpine. Pertussis toxin inhibition probably did not arise through an indirect action on the Na(+)-gradient because while, as expected, Na+,K(+)-ATPase inhibition reduced [3H]noradrenaline accumulation, pertussis toxin pretreatment always caused a further significant reduction even in the presence of maximally effective concentrations of ouabain. Stimulation of the cAMP-protein kinase A system by forskolin or 8-bromocyclic AMP also caused a reduction in [3H] noradrenaline accumulation but again pertussis toxin pretreatment always resulted in a further reduction. Thus, the data provide evidence for a pertussis toxin-sensitive element in the catecholamine accumulation process and are consistent with an action at a site directly associated with the transporter itself rather than with an indirect action via secondary processes.


Contribution of both alpha- and beta-adrenoceptors to the inotropic effects of catecholamines in the rabbit heart. The functional role of alpha-adrenoceptors was investigated in different parts of the rabbit heart. Phenylephrine (PE) caused a marked increase in force of contraction (Fc) and a prolongation of the action potential (AP) in preparations from the left atrium and the right ventricle. The response was less pronounced in the right atrium and in the left ventricle, whereas APs of spontaneously beating sinoatrial preparations remained completely unchanged. Phentolamine as well as the diesters phorbol 12,13 dibutyrate (PDBu) or 12-O-tetradecanoyl-phorbol-13-acetate (TPA) eliminated the effects of PE. The contribution of alpha-adrenoceptors to the effects of adrenaline (Adr) and noradrenaline (NA) on Fc was determined in preparations from the right ventricle. Phentolamine and the phorbol diesters reduced the effects of Adr and NA by about 30 to 60%; the remaining response was abolished by propranolol. It can be derived from our experiments that, in some parts of the rabbit heart, a considerable amount of the effects of Adr and NA is due to the stimulation of alpha-adrenoceptors. The present findings therefore support the view that, in the rabbit heart, the maximally effective drive of the heart requires the stimulation of both alpha- and beta-adrenoceptors. The inhibitory effects of phorbol diesters on the alpha-adrenoceptor-mediated response indicate that the activation of protein kinase C (PKC) specifically uncouples alpha-adrenoceptors from the effector system, whereas the response to beta-adrenoceptor stimulation remains unchanged.


Peripheral nervous system alterations in small cell lung cancer. Clinico-pathological study. Small cell lung cancer (SCLC) is one of the most malignant tumors, especially often associated with nonmetastatic neurological disorders, corresponding to paraneoplastic neurological syndromes. The pathogenesis of which is unknown, however, mostly attributed to autoimmune processes. The aim of the study was to determine the pattern of the peripheral nervous system damage in SCLC. To provide further data contributing to the pathomechanism underlying these syndromes, immunocytochemical studies were initiated. Autopsy material was collected from 47 cases of SCLC. All these patients were examined clinically. The sections from the cervical, thoracic and lumbosacral segments of the spinal cord with spinal roots and dorsal root ganglia were taken. For immunohistochemistry following antisera were used: GFAP, MBP, IgG, IgM, ferritin, ubiquitin, alpha 1-antichymotrypsin, alpha 2-macroglobulin, C3 and C5b9 complement fractions. In 18 patients peripheral nervous system disturbances were diagnosed neurologically, 21 of cases presented neuromuscular disorders by emg. Among the nonmetastatic lesions most often a damage of dorsal root ganglia was observed (in 33 cases). Degeneration of the spinal roots was absent only in 8 cases. In 21 cases degenerative changes of motor neurons within anterior horn were present. In no case ubiquitin-positive inclusion bodies within the motor neurons could be found. In 8 cases extravasation of the IgG with diffuse labeling of the grey matter was observed. IgM immunoreactivity was markedly less frequently present, C5b9 complement fraction immunoreactivity was also confined only to cases with peripheral nervous system disturbances. Therefore, our preliminary data seem to confirm the participation of humoral immunity in paraneoplastic syndrome pathogenesis.


Anti-inflammatory and analgesic effects of magnolol. Magnolol, isolated from Magnolia officinalis, inhibited mouse hind-paw edema induced by carrageenan, compound 48/80, polymyxin B and reversed passive Arthus reaction. Acetic acid-induced writhing response was depressed by magnolol, indomethacin and ibuprofen. The lethality of endotoxin challenge was reduced by pretreatment with magnolol, indomethacin and BW755C, a dual cyclo-oxygenase/lipoxygenase inhibitor. The recovered myeloperoxidase activity in edematous paw was significantly decreased in mice pretreated with magnolol and BW755C. Suppression of edema was demonstrated not only in normal mice but also in adrenalectomized animals. Magnolol was less potent on reducing PGD2 formation in rat mast cell than that of indomethacin. Unlike dexamethasone, magnolol did not increase liver glycogen level. The results suggest that the anti-inflammatory effect of magnolol was neither mediated by glucocorticoid activity nor through releasing steroid hormones from adrenal gland. The action of magnolol is proposed to be dependent on reducing the level of eicosanoid mediators.


Electron paramagnetic resonance analysis of heavy metals in the aging human brain. Electron paramagnetic studies of heavy metals were performed with the use of a Radiopan spectrometer on autopsy material of 5 aged patients (mean age 80.2 years) and 15 control patients (mean age 29 years). The obtained results lead to the following conclusions: 1. The aging brain is characterized by a tendency to decrease in concentration of isolated Cu2+ ions, and a marked decrease in concentration of Fe3+ ions as well as of free radicals, whereas the concentration of Cu2+ clusters is significantly increased. 2. The cases showing both arteriosclerotic and senile degenerative changes are characterized by higher concentrations of Cu2+ clusters than the brains with dominance of the arteriosclerotic process, whereas the concentrations of isolated Cu2+ and Fe3+ ions as well as that of free radicals do not differ between the two subgroups. 3. The diminished concentrations of Cu2+ and Fe3+ ions and free radicals observed in brains of old persons and concomitant with increased concentration of multi-ion aggregates (clusters), more marked in cases of senile atrophy of Alzheimer type, seem to result from some slow-down of metabolic processes in the aging brain.


Burst discharges of mossy fibers in the oculomotor vermis of macaque monkeys during saccadic eye movements. Mossy fiber activity was recorded from the oculomotor vermis (lobules VIc and VII) during visually guided saccades. Saccade-related activities of 99 mossy fiber units were observed in two alert macaque monkeys. Ninety-six units were characterized by high-frequency bursts of firing in response to visually guided saccades (burst unit). These units were silent during all periods of fixation in any gaze position. Three units showed eye position-related tonic discharges with saccadic bursts. The lead time of saccadic bursts ranged from 2.6 to 80.5 ms (mean 27.9 ms, SD 16.6 ms). About 75% of the burst units exhibited a long lead burst characterized by a slow buildup, while the remaining units showed short lead bursts with a sharp onset. About 80% of the units showed burst in association with contralaterally directed saccades. The remaining units exhibited bursts in association with ipsilateral saccades. Preferred directions in this population covered the entire field including the vertical and the oblique. About 68% of long lead burst units exhibited the movement field which consists of a whole sector of the entire oculomotor range (directional type). About 32% of long lead burst units showed the movement field which is a closed area within the oculomotor range (vectorial type). On the other hand, peak frequency of short lead burst units increased in proportion to saccade amplitude. The end of the burst in all units always preceded the completion of saccade. The end of burst was time-locked to the completion of saccade, so that the lead time from the end of burst to the end of saccade was consistent among these units and, was constant regardless of saccadic amplitude. The duration between the peak and the offset of burst was correlated with the amplitude of saccade (0.63 < or = r < or = 0.83). Long lead burst of mossy fibers was almost comparable to burst activity in the nucleus reticularis tegmenti pontis (NRTP), while short lead burst of mossy fibers closely resembles activity of excitatory burst neurons in the paramedian pontine reticular formation (PPRF). These findings suggest that the cerebellum receives command signal from the superior colliculus via the NRTP and feedback signal from the PPRF.


Brain pH and lactic acidosis: quantitative analysis of taurine effect. A quantitative analysis of taurine effect (facilitation of acid handling capacity of brain in response to anoxia/hypoxia by high levels of cytosolic taurine) was performed utilizing multinuclear (1H, 31P) in vivo nuclear magnetic resonance (NMR) spectroscopy and in vitro titration analysis. Taurine effects observed in vivo showed excellent quantitative agreement with the predicted values estimated based on brain taurine levels. The study confirmed that high levels of cytosolic taurine indeed facilitate acid buffering capacity of brain and this taurine effect can be readily explained by the physical, and need not involve metabolic, properties of taurine. Taurine appears to be a key component of the brain cytosol system in the fetus.


Localization of a 82 kDa protein in postsynaptic density and its association with cytoskeletons. A fraction of synaptic junctional complex (SJC) was prepared from rat synaptosomes and served as antigen material to produce monoclonal antibodies (Mab) for examining the component proteins of the SJC. An antibody, Mab SJ-8, was obtained, which recognized a protein with a molecular weight of 82,000 Da in the SJC preparation by immunoblot analysis. The immunohistochemical localization of the 82 kDa protein was studied with the rat cerebellum. Mab SJ-8 labeled the peripheral areas of the Purkinje and granule cells. Small punctate areas were also stained in the molecular layer with SJ-8. Intracellular localization of the protein was examined with rat brain synaptosomes. Immunoelectron microscopy demonstrated that Mab SJ-8 strongly labeled the postsynaptic density (PSD) and also a fibrous network spreading out of it. However, the antibody did not label the pre- or post-synaptic membrane or the cleft material.


Immunohistochemical localization of ryanodine receptors in mouse central nervous system. The distribution of ryanodine receptor-like immunoreactivity in the mouse central nervous system was studied using two antibodies raised against synthetic peptides. These peptides represented a region conserved between the cardiac and skeletal muscle forms and a region specific to the cardiac form. Western blotting analysis and [3H]ryanodine binding analysis showed ryanodine receptors are expressed in all the brain regions. The activity was prominent in hippocampus and cerebral cortex. Immunohistochemical study demonstrated that the ryanodine receptors were localized unevenly in somata. Some apical and proximal dendrites in some cells were also labeled. In hippocampus pyramidal neurons in CA2-3 region were more labeled than CA1 region. Immunohistochemical distribution revealed by two antibodies was essentially the same but the fibers were more immunoreactive with the antibody raised against the cardiac muscle ryanodine form. The localization of ryanodine receptors was quite different from that of inositol 1,4,5-trisphosphate receptors.


Monoclonal antibody immunohistochemistry of a temporal relationship between axonal elimination of aberrant olfactory nerves and synaptogenesis in the rabbit olfactory bulb during middle embryonic periods. Immunostaining using olfactory nerve- and synaptic vesicle protein-specific monoclonal antibodies revealed their characteristic appearance in the rabbit olfactory bulb during prenatal development. Prior to formation of glomeruli, olfactory nerve fibers extended beyond their target region deep into the bulb zones. Subsequently the aberrant axons decreased in number, and correspondingly, synaptic vesicle protein occurred in the innermost region of the olfactory nerve layer. It is concluded that the lack of synaptogenesis causes axonal elimination of aberrant olfactory nerves. Present results support the hypothesis that supernumerary axons degenerate unless synaptic contacts are secured; the olfactory nerves must arrive at the appropriate terminal zone in the glomeruli.


Descending pathways mediating disynaptic excitation of dorsal neck motoneurones in the cat: facilitatory interactions. Facilitatory interactions between disynaptic EPSPs evoked from the contralateral tectum, ipsilateral tegmentum and contra- and/or ipsilateral pyramid have been investigated in dorsal neck motoneurones of the cat. Monosynaptic convergence on common intercalated neurones was found from ipsi- and contralateral pyramidal, contralateral tectal and ipsilateral tegmental fibres. In addition, disynaptic facilitation was observed from ipsilateral pyramidal fibres on disynaptic contralateral pyramidal EPSPs. Transection of cortico-fugal fibres in the pyramid showed that the location of the interactions occurred in the lower brain stem, suggesting that reticulospinal neurones are mediating the effects.


Descending pathways mediating disynaptic excitation of dorsal neck motoneurones in the cat: brain stem relay. The location of intercalated neurones mediating disynaptic excitation from tectum, tegmentum and pyramids to dorsal neck motoneurones has been investigated by: (a) recording field potentials in the lower brain stem evoked from the above systems, (b) systematic stimulation in the brain stem during intracellular recording from motoneurones innervating the splenius, biventer cervicis and complexus muscles, and (c) comparing the effects of lesions of the brain stem with kainic acid on the disynaptic EPSPs elicited from the above three systems. Electrical stimulation of the contralateral superior colliculus evoked monosynaptic field potentials which were largest in the caudal pontine reticular formation rostral to the abducens nucleus and in the rostral part of the medullary reticular formation caudal to the abducens nucleus. Likewise, stimulation of the ipsilateral tegmentum (the cuneiform and subcuneiform nucleus) evoked field potentials which were large in the caudal medulla and small in the pons. In contrast, stimulation of the contralateral tegmentum was ineffective in evoking field potentials. Stimulation of the pyramid 2-3 mm rostral to the obex elicited monosynaptic field potentials in the reticular formation of the lower brain stem that were only about 25% of those from the superior colliculus. In contrast to the field potentials from the superior colliculus, the pyramidal ones were large in the medulla and small in the pons. Lesions of the reticular formation in the lower brain stem by unilateral kainic acid injection caused disappearance of disynaptic EPSPs in motoneurones from the above three systems. These results strongly suggest that the intercalated neurones mediating pyramidal, tectal and tegmental EPSPs are reticulospinal neurones in the lower brain stem. Systematic stimulation in various locations of the lower brain stem showed that monosynaptic EPSPs were evoked from the regions of the reticular formation which received projection from the above three descending systems. The effective regions for evoking the EPSPs in splenius (SPL) were located somewhat more dorsally than for biventer cervicis and complexus (BCC) motoneurones. The descending axons of presumed reticulospinal neurones were stimulated with electrodes placed in medial, middle and lateral positions at the spinomedullary junction. Monosynaptic EPSPs in SPL and BCC motoneurones were evoked from the medial and middle electrodes but not from the lateral electrode.


Postnatal development of mRNA specific for a metabotropic glutamate receptor in the rat brain. We examined the ontogenesis of a subtype of metabotropic glutamate receptors, termed mGluR1, which is linked to phosphoinositide metabolism, in various regions of rat brain during neonatal development. Northern blot analyses of mGluR1 mRNA indicated that mRNA increased monotonously or remained at plateau levels during the first 5 weeks after birth. In situ hybridization analyses supported this conclusion. The result is in contrast with the reported development of the activity in excitatory amino acid-stimulated phosphoinositide turnover during the same period. The latter increases during the first few weeks and then decreases sharply.


The human entorhinal cortex: normal morphology and lamina-specific pathology in various diseases. The entorhinal territory consists of the entorhinal and transentorhinal regions spreading over the ambient gyrus and anterior portions of the parahippocampal gyrus. The transentorhinal region mediates between the adjoining temporal isocortex laterally and the entorhinal region medially. The entorhinal cortex consists of a molecular layer, followed by an external principal stratum, a cell-sparse lamina dissecans, an internal principal stratum and--within the underlying white matter--a profound cellular layer. The principal strata can each be divided into three layers Pre alpha, beta, gamma, and Pri alpha, beta, gamma. Data obtained from experimental investigations in monkeys reveal that the entorhinal territory serves as a relay station for information from both isocortical association areas and centers of the limbic system. After processing within the entorhinal cortex, this information is transferred to the hippocampal formation via the perforant path. Pathological changes within the entorhinal territory impair this continuous data transfer and contribute to a decline of cognitive functions. Entorhinal involvement associated with impaired cognitive functions is described in cases of Alzheimer's disease, Parkinson's disease, progressive supranuclear palsy, dementia with argyrophilic grains and Huntington's disease.


Developmental changes of fucosylated glycoconjugates in rabbit dorsal root ganglia. Developmental changes of the fucosylated glycoconjugates in the dorsal root ganglia (DRG) of the rabbit were investigated histochemically using anti-fucosyl GM1 antibody and Ulex europaeus agglutinin 1 (UEA-1) lectin. Neither anti-fucosyl GM1 antibody nor UEA-1 lectin bound to the neural tubes or to the neural crest on embryonic day 14 (E14). Anti-fucosyl GM1 antibody binds diffusely to the DRG of E25. Large neurons unreactive with anti-fucosyl GM1 antibody appeared at 1 month and increased within 6 months after birth. Schwann cells immunoreactive with anti-fucosyl GM1 antibody came to be limited to the satellite cells surrounding the positive neurons. No staining with UEA-1 lectin was observed in the DRG of E25. Some small neurons became reactive with UEA-1 lectin within 1 month and remained to be so at 6 months after birth. Schwann cells including satellite cells were unreactive with this lectin. Since fucosyl GM1 was detected in the lipid fraction of DRGs from 1-month-old and 6-month-old rabbits, fucosyl GM1 itself should be the antigen molecule recognized by the anti-fucosyl GM1 antibody. Further study is necessary to elucidate the association between these developmental changes of the fucosylated glycoconjugates in DRG and their possible functional roles.


Effects of toki-shakuyaku-san (Tsumura TJ-23) on electrical activity in neuroblastoma cells and frog neuromuscular junctions. Toki-shakuyaku-san (Tsumura TJ-23) is a Chinese medicine which has been used for the treatment of gynecological symptoms in aged women. There are several reports on the usefulness of this drug in the treatment of cognitive disorders. We studied the effects of toki-shakuyaku-san on electrical activity in NG108-15 cells, a cell line of differentiated neuroblastoma x glioma hybrid cells, and on frog neuromuscular transmission. In the hybrid cells, an extract of toki-shakuyaku-san slightly depolarized the membrane potential, and strongly decreased the peak heights of the Na+ and Ca2+ current components of the action potential. The order of potency for NG108-15 cells of the 5 ingredients in toki-shakuyaku-san was soujyutsu >> shakuyaku, takusha, toki, senkyu. In voltage-clamped NG108-15 cells, toki-shakuyaku-san and soujyutsu decreased the Na+, K+, and Ca2+ current components. Toki-shakuyaku-san and soujyutsu also induced an increase in the intracellular calcium concentration. However, toki-shakuyaku-san did not affect neuromuscular transmission in the frog sartorius muscle. The results suggest that the effects of toki-shakuyaku-san on neurons are multiple, and tissue- and species-specific, and its effect derives mainly from soujyutsu.


Transient expression of estrogen-receptor-like immunoreactivity (ER-LI) in the facial nucleus of the neonatal rat. Estrogen receptor-like immunoreactivity (ER-LI) was detected in the medial subnucleus of the facial nucleus by immunocytochemistry in both male and female neonatal rats, but not in the adult rat. Identity of the motoneurons in this subnucleus projecting to the corresponding facial muscles and the cells with ER-LI positive signals was examined by retrograde tracing. The majority of the cells marked with the tracer did not carry ER-LI signals.


Retinotectal projection after partial ablation of chick optic vesicles. We excised the dorsal part of the optic vesicle of chick embryos at stages 13-14 (embryonic day 2). The remainder of the optic vesicle reoganized and developed a small eye. This study was undertaken to determine how locus specificity is kept within the reorganized retina. The projection pattern from the reorganized eyes was examined with HRP and DiI, a fluorescence axon tracer. Whole retinal fibers labeled with HRP were found on the medial half of the contralateral tectum, thus showing the lateral half of the tectum as being devoid of retinal fibers. DiI labeling revealed a detailed projection map, with the dorsoposterior to ventroanterior axis of the reorganized eye being projected as the rostrocaudal axis on the medial half of the tectum. These results suggest that the positional specificity along the anteroposterior axis of the optic vesicle was already determined at the time of excision, and that the ventral part of the optic vesicle reorganized the "whole" retina, keeping its original anteroposterior polarity.


Ocular manifestations of the congenital varicella-zoster syndrome. The congenital varicella syndrome is a rare disorder in which affected infants developed characteristic ocular and systemic manifestations. We present an infant who showed this syndrome, following maternal varicella during pregnancy. The infant had low birth weight, cicatricial skin lesions, limb contractures, hypotonia, areflexia and chorioretinal scarring. Fetal infection was demonstrated with the presence of varicella-zoster-specific IgM in the baby.


Beta-endorphin processing and cellular origins in rat spinal cord. While enkephalin and dynorphin peptides have been well characterized in the spinal cord, the cellular localization of beta-endorphin (beta E) and the processing of pro-opiomelanocortin (POMC) to beta E and other non-opioid peptides in the cord have not been extensively investigated. Other investigators have characterized the various beta E forms present in rat spinal cord regions. Previous studies have also suggested that spinal POMC content is entirely derived from supraspinal sources. However, high proportions of beta E precursors present in spinal cord sieving profiles led us to suspect the presence of POMC cell bodies intrinsic to the cord. In this study, we performed thoracic spinal cord lesions on a group of animals and demonstrated the persistence of about one-third of control levels of beta E immunoreactivity (beta E-IR) below the level of the lesions. We also characterized POMC processing in various regions of the spinal cord both before and after lesioning. These data suggested that there may be intrinsic POMC/endorphinergic neuronal systems in the spinal cord.


[The insulin receptor: mechanism of activation and message transmission]. The insulin receptor is a heterotetrameric glycoprotein composed of two 130 kD extracellular alpha subunits and two 95 kD membrane-spanning beta subunits. The insulin receptor functions as an allosteric enzyme which undergoes conformational changes when its alpha subunit binds insulin, resulting in activation and autophosphorylation of the tyrosine kinase contained in the beta subunit. This receptor activation is due to intermolecular reactions responsible for amplification of the hormone-induced response at the receptor level. Activation of the receptor tyrosine kinase initiates a cascade of phosphorylation/dephosphorylation reactions and enzyme activation/deactivation reactions. Insulin causes very rapid activation of the enzymes MAP kinase (Microtubule Associated Protein kinase) and phosphatidylinositol-3 kinase, which may act as key links between the insulin receptor and the cell effectors responsible for hormone-induced responses.


[G-protein-binding receptors].

[G-protein-binding receptors]. All G protein-binding receptors have closely similar structures. They all include seven membrane-spanning segments, with significant sequence homologies between receptors. G. Vassart and co-workers made use of this fact to devise a polymerase chain reaction (PCR) method for cloning G protein-binding receptors. This method has been used to sequence a large number of hormone receptors including the thyrotropin (TSH) receptor. The process used to isolate this receptor is described, as well as newly gained insights into the pathophysiology of autoimmune thyroid gland diseases. For some sequenced receptors, the natural ligands were not known. This required development of strategies designed at identifying the functions of these receptors. An illustrative example of this approach is the characterization of A1 and A2 receptors for adenosine.


[Biotechnology of beta-adrenergic receptors]. This article discusses the structural and functional features of a new family of membrane receptors including alpha-adrenergic and beta-adrenergic receptors for catecholamines, muscarinic receptors for acetylcholine, and receptors for histamine, dopamine, serotonin, and neuropeptides such as angiotensin. All these receptors are coupled to GTP-binding proteins, called G proteins. All G proteins have similar membrane topologies with a single peptide chain composed of seven membrane-spanning domains separating a series of successive extracellular and intracellular portions. Results of studies of beta-adrenergic receptors suggest that some amino acids in the seven membrane-spanning domains are part of the ligand-binding site, whereas the protein G-coupling site seems to involve amino acids located in the third cytoplasmic loop and in the C-terminal extremity, which also contains the phosphorylation sites. Genes encoding this family of receptors exhibit sequence homologies and also contain sequences which may be involved in the regulation of the level of expression of these receptors. Recent development of a receptor-expressing bacterial system can be expected to provide significant advances in the accurate investigation of receptor structure-function correlations.


Primary pulmonary tumors in childhood: a review of 31 years' experience and the literature. Primary pulmonary tumors are infrequent in childhood, therefore an accurate diagnosis and treatment is often delayed. We review the English language literature and report the clinical and pathological features of eight tumors arising in the lungs of pre-adolescent children, accessioned between 1960 and 1991 in the pathology department of a children's hospital in South Africa. The ratio of pulmonary primary tumors to secondary neoplasms and to non-neoplastic lesions of the lung examined during this period was 1:5:60. Over the last 31 years we received three plasma cell granulomas, two pleuro-pulmonary blastomas, a mucoepidermoid carcinoma, an endobronchial fibrosarcoma, and a hemangioma. All patients presented with cough unresponsive to medical treatment. The incidence and spread of primary lung tumors in children was similar to that reported from other centers. Plasma cell granuloma is the most common primary tumor in the lungs of children. Aggressive behavior is most frequently encountered with pleuro-pulmonary blastoma and rhabdomyosarcoma, and because of their association with cystic lesions careful examination of lungs is required in such cases. Most other malignant neoplasms, such as muco-epidermoid carcinoma and primary fibrosarcoma, are usually of a low grade of malignancy. A decreasing incidence of bronchogenic carcinoma seems to be reported during the first two decades of life.


Craniosynostosis--corrective surgery for a cosmetic defect. Premature fusion of the sutures of the skull is known as craniosynostosis, and is characterised by an abnormal skull shape. Early surgery allows the brain to resume its normal shape, encouraging a more natural pattern of development. Nursing care in a craniofacial unit aims to promote maximum physical recovery and improvement, while offering psychological support and understanding to the child and family.


Behavioral conditioned responses to contextual and odor stimuli paired with LiCl administration. The present experiments examined whether behavioral conditioned responses (CRs) develop to LiCl-paired contextual and odor stimuli, and whether these CRs are similar to the behaviors observed following the administration of the drug. During conditioning, a novel context (Experiment 1) or a novel odor (Experiment 2) was paired with LiCl injections, and the CRs which developed to these stimuli were assessed during testing. Suppression of general activity occurred after LiCl exposure and after exposure to the lithium-paired context and odor. However, the actual behaviors which emerged as conditioned responses were distinctly different from those which were elicited by the drug itself. Lying on belly was the predominant unconditioned response to LiCl. Freezing was the predominant CR to the context, whereas gaping was the predominant CR to the odor. These outcomes are discussed and compared to previous results using a taste stimulus.


Malaise can condition avoidance of high-viscosity fluids. Previous researchers have assumed that malaise-inducing drugs condition aversions to tastes more readily than to textural stimuli. The present report shows that rats given a single injection of lithium chloride after they have sampled a viscous fluid, subsequently showed greater avoidance of that fluid than did control rats. Rats learned this response even when the lithium chloride injection was given 60 min after they sampled the viscous fluid. The generalization gradient for viscous fluids is apparently very broad, because rats trained to avoid 11 or 95 cp fluids subsequently avoided 11 and 95 cp fluids to a similar degree. Nevertheless, this avoidance is based on textural cues because rats injected with lithium chloride after ingesting one viscous fluid subsequently avoided a wide variety of viscous fluids, including those made from carbohydrate polymers (algin, guar, xanthan), a modified carbohydrate (methyl cellulose), and a protein (methyl cellulose). However, the flavors of viscous gums may influence texture aversion.


Characterization of tailshock elicited withdrawal reflexes in intact and spinal rats. The tail flick withdrawal reflex (TFR) was generated by applying graded electric current to the tail of intact and spinally transected rats. In Experiment 1, separate groups of rats were tested 1, 3, 7, 10, 14, or 21 days after spinal transection. The latency, amplitude, and magnitude of the TFR was highly related to current intensity in both intact and spinal animals. However, the TFR changed dramatically as a function of the number of days between spinalization and TFR measurement. Compared to intact controls, the current intensity at which TFR was initiated (threshold) in spinal rats was elevated 1 and 3 days after transection, did not differ at 7 and 10 days, and was reduced at 14 and 21 days. Latency of TFR in spinal rats did not differ from controls 1 day after transection, but decreased steadily thereafter. Amplitude and magnitude of TFR in spinal rats remained depressed, but did show recovery toward control levels as the interval between transection and testing increased. Changes in the TFR of spinal rats was correlated with recovery of tailpinch-elicited hindlimb withdrawal. Experiment 2 demonstrated that the dose-response curve relating systemic morphine treatment to increases in TFR thresholds was shifted to the right in chronic spinal rats. Threshold increases in both spinal and intact rats were not necessarily accompanied by changes in TFR performance. These experiments establish the segmental organization of tailshock-elicited TFR and supports its use as a measure of nociceptive transmission at spinal levels.


Circadian rhythms of hypothalamic norepinephrine and of some circulating substances in individually housed adult rats. The circadian rhythms of hypothalamic norepinephrine (NE) and of circulating norepinephrine, epinephrine (E), corticosterone, aldosterone, and serotonin (5HT) were determined in group-housed and in individually housed male adult rats, adapted to a 12/12 light/dark cycle. After 5 weeks of individual housing, compared to group-housed animals, hypothalamic NE mesor decreased, while circulating NE, E, and corticosterone mesor increased. The circadian rhythms of aldosterone and 5HT were unaffected by individual housing.


Free-feeding and free-drinking patterns of male rats following treatment with opiate kappa agonists. Three experiments investigated the effects of PD117302 and U50,488H on the patterns of food and water intake by male rats. Experiment 1 demonstrated early dose-related suppression of food and water intake after PD117302 (0, 1.25, 2.5, 5 mg/kg). The initial suppression of drinking was followed by a sustained increase 4-12 h after drug administration. Experiment 2 demonstrated that 2.5 mg/kg PD117302 failed to increase food intake whether given at the beginning of the night (high baseline food intake) or the beginning of the day (low baseline food intake). Experiment 3 showed that 0.5 mg/kg U50,488H significantly enhanced meal size but, at doses of 0.5, 1.0, and 2.0 mg/kg, had no effect on overall food intake. U50,488H also produced delayed, dose-related increases in water intake. The results suggest kappa receptors may have limited importance in modulating ad lib food intake and demonstrate the behavioural characteristics of increased drinking after excessive urine output.


Anti-inflammatory activity of gallic acid. Gallic acid was found to possess antiinflammatory activity towards zymosan-induced acute food pad swelling in mice. In vitro studies on the mode of action of gallic acid revealed that this compound interferes with the functioning of polymorphonuclear leukocytes (PMNs). Scavenging of superoxide anions, inhibition of myeloperoxidase release and activity as well as a possible interference with the assembly of active NADPH-oxidase may account for the inhibition of inflammatory process by gallic acid. Structure-activity relationship analysis showed that the o-dihydroxy group of gallic acid is important for the inhibitory activity in vitro.


Structural transformation of lignan compounds in rat gastrointestinal tract. Structural transformation of arctiin and tracheloside, major components of seeds of Arctium lappa and Carthamus tinctorius, were investigated using rat gastric juice (pH 1.2-1.5) and rat large intestinal flora in vitro. Quantitative analysis of lignans and their metabolites was carried out by high performance liquid chromatography. Both lignans were stable in rat gastric juice and arctiin was rapidly transformed to arctigenin in rat large intestinal flora, followed by conversion to the major metabolite, 2-(3",4"-dihydroxybenzyl)-3-(3',4'-dimethoxybenzyl)-butyrolactone. On the other hand, tracheloside also decreased dependently with time and was converted to trachelogenin and its major metabolite, 2-(3",4"-dihydroxybenzyl)-3-(3',4'-dimethoxybenzyl)-2-hydroxybutyrola ctone. These experiments suggest that in the course of metabolism of lignans, firstly a cleavage of the glycosidic bond occurred and then demethylation of the phenolic methoxy group in the alimentary tract followed.


Sub-acute effects of interferon-alpha 2 on adrenocorticotrophic hormone, cortisol, growth hormone and prolactin in humans. This study investigated the chronic effects of interferon-alpha 2 (IFN-alpha 2) on hormonal secretion in humans. Six patients suffering from chronic hepatitis B or C infection received SC doses of 3 million IU IFN-alpha 2 three times a week for 4 mo. Each patient was examined for hormone secretion four times: the day before initial IFN-alpha 2 administration (day 0), the day of the first injection (day 1), and 4 wk after start of IFN therapy on days 27 (without IFN administration) and 28 (with IFN administration). Adrenocorticotrophic hormone (ACTH), cortisol, growth hormone (hGH), and prolactin (PRL) were measured in plasma samples drawn at 30-min intervals between 1600h and 2400h. Acute administration of IFN-alpha 2 stimulated the release of ACTH to 423% (p = 0.02 vs. day 0) and cortisol to 393% (p = 0.01 vs. day 0) of control values in each patient. In five of the six patients, the plasma levels of hGH were higher on day 1 than on day 0. IFN-alpha 2 did not affect the secretion of prolactin. On day 27, the plasma levels of the four hormones were similar to the baseline levels on day 0. When IFN-alpha 2 was given on day 28, there were no significant differences in the release of ACTH (135% of control, p = 0.4) or cortisol (124% of control, p = 0.5) in comparison to day 27. These findings indicate that IFN-alpha 2 stimulation of hormone release is restricted to specific hormones.(ABSTRACT TRUNCATED AT 250 WORDS)


Neuroendocrine response to psychological performance testing. Neuroendocrine changes associated with performance testing requiring sustained attention were assessed in eight normal male subjects. To verify whether the hormonal pattern was modified by chronic stimulation of opiate receptors, eight heroin addicts also were studied. Reaction times were similar in normal and addict subjects. In normal individuals, consistent and significant increases in plasma ACTH and beta-endorphin and in urinary epinephrine and norepinephrine were observed, whereas serum prolactin (PRL) progressively decreased over the testing period. Despite maintained performance capabilities, heroin addicts showed a blunted response of ACTH and a paradoxical decrease in endorphin levels. As the normal subjects, both epinephrine and norepinephrine in urine showed the same significant increase over baseline values. Serum PRL showed a similar trend towards decreased values over the testing period in both groups.


Co-localization of brain corticosteroid receptors in the rat hippocampus. New developments in corticosteroid receptor research enabled us to perform a highly detailed study on the neuroanatomical topography of MR and GR in the rat hippocampus. Receptor immunocytochemistry was used to map the distribution of GR protein with the help of a monoclonal antibody raised against the purified rat liver GR-hormone complex. Furthermore, in situ hybridization with 35S-labeled RNA probes, which were transcribed from cDNAs complementary to either a fragment of the rat brain MR gene or to the rat liver GR gene, was applied to investigate the localization of MR and GR mRNA in the limbic brain. The pyramidal neurons of cell field Ca1 and CA2 and the granular neurons of the dentate gyrus showed marked GR immunoreactivity (GRir) as well as intense labeling of GR mRNA. The radiolabeled density of GR mRNA in cell fields CA3 and CA4 was considerable less, whereas low-to-almost-undetectable levels of GRir could be observed in these regions. MR mRNA appeared to be evenly distributed over all cell fields of the hippocampus and the dentate gyrus. The topography of GRir, GR mRNA and MR mRNA was found to agree with the cellular distribution of MR and GR binding sites in the hippocampus. Moreover, the microanatomy of MR and GR in the hippocampus appeared to overlap. Our data strongly suggest that MR and GR are co-expressed in the majority of pyramidal and granular neurons of the hippocampal formation. This assumption is based on coherence in the detection of different aspects of the receptor cycle of MR and GR.(ABSTRACT TRUNCATED AT 250 WORDS)


Stimulation of Cl secretion by lactoferrin across canine airway epithelial cells in culture. To investigate the effect of lactoferrin, an iron-binding glycoprotein in the respiratory tract, on ion transport function of airway epithelial cells, we measured bioelectric properties of canine cultured tracheal epithelium by Ussing's short-circuit technique. Addition of lactoferrin (60 micrograms/ml) to the mucosal side of epithelial sheet increased the short-circuit current (Isc) from 4.8 +/- 0.8 to 7.5 +/- 1.1 microA/cm2, and the submucosal addition likewise increased Isc from 3.8 +/- 0.6 to 5.6 +/- 0.7 microA/cm2 (p < 0.001, in each case). This effect was concentration dependent. The lactoferrin-induced increase in Isc was not altered by amiloride, indomethacin, or propranolol but was abolished by diphenylamine-2-carboxylate or substitution of Cl with iodide in the medium. Intracellular cyclic AMP levels were not increased by lactoferrin. These results suggest that lactoferrin may selectively stimulate Cl secretion across the airway mucosa, an effect that may not be dependent on prostaglandins, beta-adrenergic receptor or intracellular cyclic AMP.


Unusual retinal and renal vascular lesions in the Klippel-Trenaunay-Weber syndrome. Ocular fundus abnormalities associated with the Klippel-Trenaunay-Weber syndrome are uncommon and include retinal vascular tortuosity and diffuse choroidal hemangioma. A case involving a young girl with Klippel-Trenaunay-Weber syndrome who had unusual bilateral, exudative, outer retinal vascular masses involving the peripheral fundus in one eye and the foveal area in the other eye is reported. Kidney biopsy for renal insufficiency disclosed abnormal excess mesangial tissue. The fundus lesions appear to represent vascular tumors of the retina that differ clinically from previously reported retinal vascular tumors and Coats disease. The simultaneous retinal and renal involvement suggest that Klippel-Trenaunay-Weber syndrome may be associated with more widespread vascular malformations than previously realized.


Prediction of silicosis and lung cancer in the Australian labor force exposed to silica. Empirical models for risk, based on recently published epidemiologic data, and simple prediction formulas were used to predict the occurrence of silicosis and lung cancer in the Australian labor force currently exposed to crystalline silica dust. As a result of an 0.9 (range 0.4-1.9)% average lifetime risk, approximately 1010 (range 380-2410) silicosis cases were predicted for the next 40 years among the estimated 136,400 men exposed at current silica dust levels [0.01-0.8 (average 0.094) mg.m-3]. Approximately 630 extra lung cancer cases (95% confidence interval 120-1320) would appear with an average excess risk of 0.5 (interval 0.1-1.1)%, the proportion of silica-induced lung cancer cases being about 15%. Currently 77% of the at-risk labor force is exposed to silica dust levels of < or = 0.1 mg.m-3. With this level as the limit, about 440 (range 140-1210) silicosis cases and 410 (interval 90-780) extra lung cancer cases would occur in 40 years. Adopting this level as the national exposure standard would reduce the risk of silicosis cases by 52% and the excess risk of lung cancer by 36%.


Prevalence in two mexican cities of human papillomavirus DNA sequences in cervical cancer. In Mexico, about 30% of all malignant tumors in women are uterine cervix carcinomas. It is one of their main causes of death. We have previously shown that in Mexico City, 31% (5/16) of the analyzed tumoral samples contained HPV-16 DNA sequences. We have now extended this observation in Mexico City and included the city of Monterrey and found that the prevalence of HPV-16 is similar in both: 26% (6/23) for Monterrey and 29% (4/14) for Mexico City. HPV-18 was detected in only 10% (1/10) and 7% (1/14) of the tumors in these two populations when assayed with an HPV-18 specific probe. In both cities, the majority of the samples analyzed (including samples from the four stages of severity of the disease) contained integrated papillomavirus DNA sequences. Our results suggest that the mexican population contains a rather low proportion of HPV-16 and HPV-18 sequences in uterine-cervix carcinoma.


A phase II study of ifosfamide in combination with etoposide and cisplatin in the treatment of extensive small cell lung cancer. The combination of etoposide and cisplatin has become one of the standard treatments for small cell lung cancer. Ifosfamide, an analogue of cyclophosphamide, has demonstrated single-agent antitumor activity comparable with that of the most active agents used to treat small cell lung cancer. Because ifosfamide is relatively nonmyelosuppressive and its principal dose-limiting toxicity, urotoxicity, has largely been eliminated with the introduction of the uroprotective agent mesna, we undertook a phase II study of the combination of all three agents (etoposide/ifosfamide/cisplatin) in good-performance-status, extensive-disease patients 70 years of age or younger. Twenty-five patients (17 men and eight women; median age, 58 years) were treated with 75 mg/m2 etoposide, 20 mg/m2 cisplatin, and 1.0 g/m2/d ifosfamide administered intravenously for 5 days. Mesna (200 mg/m2) was given as a bolus prior to the first day of chemotherapy and then daily by continuous infusion (900 mg/m2 over 24 hours) between administrations of chemotherapy. Mesna was continued for 12 hours after the last dose of ifosfamide. Treatment cycles were planned every 4 weeks for four cycles. Due to severe toxicities in the first eight patients, subsequent patients received only 4 days of treatment (20% dose reduction). Of the 25 extensive-disease patients studied, 23 are evaluable for response. Seven (30%) achieved a complete response and 10 (43%) had a partial response (overall response rate, 73%). Five patients (22%) had stable disease (< 50% decrease and no evidence of disease progression for at least 4 weeks), and disease progressed in 1 patient (4%). The median survival time was 42 weeks (range, 2 to 160+ weeks). Granulocytopenia was dose-limiting: median granulocyte count was 0.486 x 10(9)/L, 21% of cycles had a granulocyte nadir below 0.2 x 10(9)/L, and four patients died of sepsis. Three patients required platelet transfusion and nine needed blood transfusion. Microscopic hematuria occurred in eight patients (11% of treatment cycles) but was reversible in all cases. A number of central nervous system symptoms were reported but could not be definitely attributed to ifosfamide/mesna. Gastrointestinal toxicity was generally mild, which is attributed to the use of an aggressive antiemetic program. The etoposide/ifosfamide/cisplatin regimen is active and produced a complete response rate of 30% in extensive small cell lung cancer; the duration of response and survival appears similar to that of other standard regimens. The 5-day schedule produced excessive toxicity in this patient population, necessitating a 20% dose reduction (by using a 4-day schedule). The method of administration required a minimum of 5 hospital days per cycle.(ABSTRACT TRUNCATED AT 400 WORDS)


Phase II study of cisplatin, ifosfamide, and etoposide combination for advanced non-small cell lung cancer: final report. Ifosfamide has shown promising single-agent activity in non-small cell lung cancer. We combined ifosfamide (1,800 mg/m2, plus 1,100 mg/m2 of mesna by intravenous continuous infusion daily for 3 days) with cisplatin (20 mg/m2 intravenously for 3 days) and etoposide (80 mg/m2 intravenously for 3 days) and treated 41 patients with recurrent or metastatic non-small cell lung cancer who had received no prior systemic chemotherapy. Fifteen (40.5%) of the 37 evaluable patients had objective responses (one complete and 14 partial). Patients with a good Zubrod performance status (ie, 0 or 1) had a higher response rate than those with poor performance status (ie, 2) (11 of 21 [52.4%] v 4 of 16 [25.0%]), but the difference was not statistically significant (P = .09). Median survival was 28 weeks for all patients and 59+ weeks for responders, with 11 patients still alive after a median follow-up of 59 weeks (range, 51 to 77 weeks). Overall, treatment was well tolerated, with granulocytopenia being the most frequent toxicity. Considering the pooled response rate of 32% with a cisplatin/etoposide regimen and the previous experience from our institution, the results with this three-drug regimen are encouraging, and its further investigation is warranted, particularly for patients who have good performance status and in a neoadjuvant setting.


Ifosfamide-based chemotherapy for patients with resistant germ cell tumors: the Memorial Sloan-Kettering Cancer Center experience. Sixty-six patients with germ cell tumors (GCTs) refractory to cisplatin plus etoposide/vinblastine-based therapy were treated with cisplatin, ifosfamide, and either etoposide (VIP) (50 patients) or vinblastine (VeIP) (16 patients). Sixty-two patients were evaluable for response. Twenty-one patients (34%) achieved a complete response (CR), 18 with chemotherapy alone and an additional three following surgical resection of viable tumor. Six of these patients have relapsed, and 15 (24%) remain in CR at a median follow-up of 13 months (range, 3+ to 41+ months). Three patients who achieved an incomplete response or relapsed from CR are disease free following additional salvage therapy; one patient underwent resection of a solitary metastasis and two received high-dose chemotherapy with autologous bone marrow rescue. Ifosfamide adds efficacy to cisplatin plus etoposide or vinblastine-based salvage therapy. Ifosfamide/cisplatin-based combinations should be considered in the first-line salvage treatment of germ cell tumors. The modest proportion of patients who achieve a durable CR following salvage therapy with VIP/VeIP emphasizes the need for early identification of treatment failure and more effective salvage therapy.


Long-term survival after the diagnosis of malignant glioma: a series of 22 patients surviving more than 4 years after diagnosis. Long-term survival after the diagnosis of malignant glioma is uncommon but not rare. To define better the population of patients who have extended survival with this disease, we reviewed the records of 22 of our patients who survived more than 4 years after the biopsy-proven diagnosis of anaplastic astrocytoma, malignant mixed glioma, or glioblastoma multiforme. Surprisingly, 21 of the 22 patients are still alive and being actively followed by the authors. The long-term survivors were typically young and with minimal or no functional impairment at the time of diagnosis. Survivals ranged from 4.2 to 15.8 years. The quality of survival was generally good, with the surviving patients having a mean Karnofsky Performance Score of 76. Three-quarters of the patients had no enhancement or mass effect on their most recent computed tomography scans. A review of the available literature, together with our own series, suggests that death from recurrent disease is unusual in glioma patients who survive more than 4 or 5 years.


[Low molecular weight heparin: favorable effect profile for prevention and therapy of venous thrombosis]. This short review addresses the use of low molecular weight heparins (LMWH) for prevention and treatment of venous thromboembolism. In general surgery, the once daily subcutaneous (sc) administration of LMWH provides at least as much protection against thrombosis as 2 to 3 times 5000 IU sc of unfractionated heparin (UFH). In high-risk orthopedic surgery LMWH prophylaxis is definitely more efficient than conventional regimens with UFH or dextran. Several studies convincingly demonstrate that LMWH may be at least as good as UFH for the treatment of deep venous thrombosis.


Malignant fibrous histiocytoma of the heart--case report of a rare left-atrial tumor. The present report describes the case of a 57-year-old patient with malignant fibrous histiocytoma of the left atrium operated on for a suspected atrial myxoma. Surgery was performed as radically as possible and included resection of the atrial wall. Clinical investigation and echocardiography performed 29 months after surgery revealed no signs of tumor recurrence. Diagnostic procedures, topography, pathohistology as well as options for therapy are discussed with regard to the latest literature. A radical surgical approach represents the only effective therapeutic measure. Owing to a lack of sufficient experience, there is no additional therapeutic recommendation on hand. Neither radiation nor chemotherapeutic treatment concepts have proved efficient. Echocardiography represents the best examination procedure for both diagnosis and follow-up in patients with cardiac tumor.