Antiproteases attenuate the release of neutrophil chemotactic activity from bronchial epithelial cells induced by smoke

The released neutrophil chemotactic activity (NCA) from bronchial epithelial cells (BECs) in response to smoke extract was evaluated by reverse-phase, high-performance liquid chromatography (RP-HPLC) and the involvement of proteolytic activity was assessed for the release of NCA from BECs. Smoke extract stimulated the release of NCA (55.3 +/- 5.2 vs. 17.3 +/- 4.1 cells per high-power field [HPF], p < .001). The released activity determined by RP-HPLC analysis was 15-hydroxyeicosatetraenoic acid and leukotriene B4. Several structurally and functionally different serine protease inhibitors, including alpha-1-protease inhibitor (alpha-1-PI), chloromethyl ketone (CK) derivatives, N-tosyl-L-lysine CK (TLCK), methoxysuccinyl-Ala-Ala-Pro-Val CK (SPCK), N-alpha-tosyl-L-phenylalanine CK (TPCK), and N-alpha-p-tosyl-L-arginine methyl ester hydrochloride (TAME), attenuated the release of NCA (P < .01) in a dose-dependent fashion. Leupeptin, a cysteine protease inhibitor, has only a small effect on the release of NCA (p < .05), and phosphoramidon, a neutral endopeptidase inhibitor, had no effect. The measurement of proteolytic enzyme activity using synthetic substrate S-2288 revealed that smoke extract significantly (p < .05) augmented the serine protease activity in BEC layers. Culture supernatant fluids and cell lysates of BECs in response to smoke extract solubilized 14C-labeled casein. These results suggest that BECs may release lipoxygenase-derived NCA in response to smoke extract and that the release of NCA may involve the activation of proteolytic activity of BECs which was inhibited by serine protease inhibitors.

Effects of noxious cooling of the skin on pain perception in man

By means of somatosensory evoked brain potentials following painful CO2 laser stimulation (pain SEPs) and a pain visual analogue scale (VAS), we investigated changes in pain perception caused by noxious cooling of the skin in normal subjects. Pain SEPs were recorded from scalp electrodes following laser stimulation applied to the leg under various conditions as follows: (1) control (without any interference); (2) 46 degrees C foot (dipping the foot ipsilateral to the stimulated leg in hot water at 46 degrees C); (3) 0 degrees C foot (dipping the foot ipsilateral to the stimulated leg in ice water at 0 degrees C); and (4) 0 degrees C hand (dipping the hand contralateral to the stimulated leg in ice water at 0 degrees C). Marked decreases in amplitude of pain SEPs and VAS were observed under all conditions as compared with the control (P < 0.001); the degree of pain relief was significantly correlated with changes in pain SEPs. These changes were greatest in the '0 degrees C hand' condition, followed in decreasing order by '0 degrees C foot' and '46 degrees C foot', and there was a significant difference between '0 degrees C hand' and the '46 degrees C foot' condition. We considered that the decrease in pain is due to the diffuse noxious inhibitory control (DNIC). The reason why the degree of pain relief in '0 degrees C foot' condition was less than that in '0 degrees C hand' condition is unclear, but some particular spatial summation of two kinds of nociceptive impulses mediated by the same pathway might take place.

Systemic lupus erythematosus with pulmonary hypertension

A 50-year-old Japanese female with a long history of Raynaud's phenomenon presented with progressive dyspnea due to pulmonary hypertension. The diagnosis of systemic lupus erythematosus was confirmed by proteinuria, lymphocytopenia, bilateral pleurisy, and a seizure of convulsion which was consistent with neurological manifestations of systemic lupus erythematosus, whereas the antinuclear antibody showed a low titer. Despite improvement in the activity of systemic lupus erythematosus, steroid treatment did not alter the progression of pulmonary hypertension, which increased in severity, eventually resulting in her death. We believe pulmonary hypertension to be an unusual but critical complication of systemic lupus erythematosus.

Intracerebral interactions caused by bilateral median nerve stimulation in man: a magnetoencephalographic study

Somatosensory evoked magnetic fields (SEFs) following stimulation of the median nerves bilaterally ('bilateral' waveform) were examined in normal subjects to determine the interference effects of activation of sensory areas in bilateral hemispheres. SEFs following right median nerve stimulation and those following left median nerve stimulation were summated ('summated' waveform). A 'difference' waveform was induced by subtraction of the 'bilateral' waveform from 'summated' waveform. Short-latency deflections showed no consistent differences between the 'summated' and 'bilateral' waveforms, but the middle-latency deflection. N60m-P60m, in the 'bilateral' waveform was significantly (P < 0.01) smaller than that in the 'summated' waveform. The long-latency deflection, the N90m-P90m, in the 'bilateral' waveform was markedly (P < 0.001) reduced in amplitude as compared with the 'summated' waveform. The differences were clearly identified in the 'difference' waveform, in which the main deflections, U90m-D90m, were found in all subjects. Equivalent current dipoles (ECDs) of the short- and middle-latency deflections were located in the primary sensory cortex (SI) contralateral to the stimulated nerve, but ECDs of the N90m-P90m and U90m-D90m were located in bilateral second sensory cortices (SII) which are considered to receive ascending signals from bilateral sides of the body.

A scintillating fiber beam-energy monitor for electron beam therapy

A new type of beam-energy monitor is described, which has been developed to check the energies of electron beams from radiotherapy accelerators. The monitor consists of a pair of scintillating fibers and photodiode read-out circuits that measure the energy dependence of electron transmission through a wedge-shaped absorber. A linear energy response and 1% accuracy for energy constancy measurements are attained with the monitor. The monitor having advantages of simple mechanical and electronic constructions, small size, and low cost is suitable for practical use as a portable device.

Pain-related somatosensory evoked magnetic fields

Somatosensory evoked magnetic fields (SEFs) following painful electrical stimulation of the finger were investigated in 5 normal subjects. Equivalent current dipoles (ECDs) of deflections shorter than 100 msec in latency were located in the primary sensory cortex (SI) in the hemisphere contralateral to the stimulated finger following either non-painful or painful stimulation. Two main deflections, N100m-P100m and N250m-P250m, were independently identified following painful stimulation, although they were not found in SEFs following non-painful weak stimulation. ECDs of the N100m-P100m were considered to be located in the bilateral second sensory cortices (SII). ECDs of the N250m-P250m were identified in the bilateral cingulate cortices and SII, but the intersubject difference was large. Therefore, we considered that contralateral SI and bilateral SII were initially activated by painful noxious stimulation, and then multiple areas including bilateral SII and cingulate cortices were activated. In EEG recordings (evoked potentials), no potential corresponding to N100m-P100m was found, probably because it was difficult to record activation in SII by EEG recordings. The P250 potential which corresponded to the N250m-P250m was clearly identified, probably because activation of multiple areas generated large long-duration EEG potentials which were maximal around the vertex, unlike MEG recordings.

rap1 p21 regulates the interaction of ras p21 with RGL, a new effector protein of ras p21

We have recently found that ralGDS family members (RGL and ralGDS) are putative effector proteins of ras p21. rap1 p21 is a small GTP-binding protein which has the same amino acid sequence as the effector loop of ras p21. We examined the effect of rap1 p21 on the interaction of ras p21 with RGL. The GTP-bound form of rap1 p21 interacted with RGL as well as did ras p21. rap1 p21 inhibited the interaction of ras p21 with RGL. RGL was phosphorylated by cyclic AMP-dependent protein kinase (protein kinase A). Phosphorylation of RGL did not affect its binding to ras p21 and rap1 p21 under the conditions that phosphorylation of Raf-1 reduced its affinity for ras p21. These results demonstrate that rap1 p21 but not protein kinase A regulates the interaction of ras p21 with RGL and suggest that rap1 p21 and protein kinase A may cooperate to distinguish the signal or ras p21 to RGL from that to Raf-1.

[Mechanisms of hypertonic saline-induced bronchoconstriction in guinea pigs]

We examined whether inhalation of hypertonic saline can induce bronchoconstriction in guinea pigs, and also studied the mechanisms of this bronchoconstriction. Twenty-five male Hartley guinea pigs were divided into the following 5 groups: G-1, 0.9% saline inhalation; G-2. non-treatment and inhalation of hypertonic saline; G-3, capsaicin pretreatment and inhalation of hypertonic salines; G-4, ipratropium bromide pretreatment and inhalation of hypertonic saline; G-5, chlorpheniramine pretreatment and inhalation of hypertonic saline. RL and Cdyn were serially measured to assess bronchoconstriction, and the percent increase in RL from the value measured before inhalation of hypertonic saline (%RL) was analyzed. The maximum %RL was 9.2 +/- 3.8% in G-1, 90.6 +/- 6.6% in G-2, 11.2 +/- 5.7% in G-3, 9.0 +/- 6.0% in G-4, and 47.8 +/- 4.0% in G-5. The values in G-3 and G-4 were significantly lower than in G-2. We conclude that inhalation of hypertonic saline causes concentration dependent bronchoconstriction in guinea pigs and that both non-adrenergic non-cholinergic nerves and cholinergic nerves may play an important role in this bronchoconstriction.

Primary tubular adenocarcinoma arising in the duodenal limb of reconstructed gastroduodenostomy for signet-ring cell carcinoma of the stomach

Adenocarcinoma of the small intestine is uncommon. Due to this paucity and the lack of specificity of symptoms, patients are usually seen late in the course of their illness, when curative therapy, mainly represented by extensive surgical resection, is unlikely. The authors report a case of primary well-differentiated tubular adenocarcinoma (T4N0M0) arising in the duodenal limb of a reconstructed Billroth I gastroduodenostomy, 9 years after a distal gastrectomy for signet-ring cell carcinoma of the stomach (T4N0M0). Evidence for excluding the possibility of a recurrence of the primary gastric cancer was based on the different histologic pattern, the long disease-free interval, and other features of the second neoplasm. Relatively early diagnosis of the neoplasm, followed by curative surgical therapy was made possible by the early onset of the obstructive symptoms and the favorable anatomical location of the tumor.

Experimental rat model representing both acute and chronic heart failure related to autoimmune myocarditis

The most important clinical manifestation of myocarditis is congestive heart failure. The precise mechanisms of heart failure during myocarditis have not been elucidated because no animal model that would permit in vivo study of hemodynamics in severe active myocarditis has been available. We monitored hemodynamics and left ventricular function in a rat model of experimental autoimmune myocarditis to determine if this model could be useful for the study of in vivo hemodynamics in severe active myocarditis. Lewis rats were immunized with human cardiac myosin suspended in complete Freund's adjuvant. Baseline hemodynamics were measured using an ultraminiature catheter pressure transducer via the right internal carotid artery, 4 weeks after immunization in one group of rats (acute phase) and 3 months after immunization in another group (chronic phase). Untreated rats served as the control group. Hemodynamic measurements were also obtained after infusion of dobutamine in the acute-phase and chronic-phase groups. The heart weight-to-body weight ratios were significantly higher in both the acute-phase group and the chronic-phase group compared with normal control rats. The baseline left ventricular systolic pressure was significantly lower in the chronic phase group than in the control group. Peak dP/dt and peak -dP/dt were significantly lower in both the acute-phase group and the chronic-phase group compared with the control group. Dobutamine significantly increased left ventricular systolic pressure, peak dP/dt, and peak -dP/dt in the chronic-phase group but caused only minor changes in hemodynamic variables in the acute-phase group. In vivo measurements of hemodynamic variables indicated the presence of left ventricular dysfunction in rats with experimental autoimmune myocarditis. This animal model may be useful for the study of both acute heart failure related to acute myocarditis and chronic heart failure due to diffuse myocardial fibrosis.

No effects of large doses of catecholamines on vascular permeability in isolated blood-perfused dog lungs

Neurogenic pulmonary oedema (NPO) is believed to be induced by intense activation of the sympathetic nervous system, characterized by massive secretion of catecholamines into the blood stream. There is a possibility that NPO is partly the result of increased vascular permeability. However, the mechanism for an increase in pulmonary vascular permeability is not known. The present study was designed to test the hypothesis that large doses of catecholamines increase pulmonary microvascular permeability directly. Adrenaline or noradrenaline (100 and 300 micrograms) was injected as a bolus into isolated dog lungs perfused with heparinized autologous blood at constant pressure. Adrenaline or noradrenaline produced sustained lung weight loss although both catecholamines increased pulmonary capillary pressure, assessed by double occlusion pressure, by 2-5 mmHG above baseline. Vascular permeability, as measured by the capillary filtration coefficient and the isogravimetric capillary pressure, did not change significantly from baseline at 30 and 60 min after catecholamine. Finally, the final-to-initial wet lung weight ratio of the catecholamine-treated lungs did not differ from that of saline-injected control lungs. Thus, we conclude that circulating catecholamines, even at supraphysiological doses, do not increase permeability in isolated blood-perfused dog lungs.

Calcium and protein kinase C dependency of lipoxygenase-derived neutrophil chemotactic activity release from bronchial epithelial cells

In the present investigation, we evaluated the roles of calcium, calcium-calmodulin, inositol turnover, and protein kinase C in the release of lipoxygenase-derived metabolites with neutrophil chemotactic activity (NCA) from bronchial epithelial cells (BECs) in response to endotoxin (ETX) and opsonized zymosan (OZ). Both ETX and OZ stimulated BECs to release NCA [56.9 +/- 5.1 (ETX), 65.2 +/- 5.1 (OZ) versus 15.2 +/- 3.0 (controls) cells/high power field, P < 0.001]. The lipoxygenase inhibitors, nordihydroguaiaretic acid and diethylcarbamazine, and phospholipase A2 inhibitors, mepacrine and dibucaine, blocked the release of NCA in response to ETX, OZ, calcium ionophore A23187 (A23187), and phorbol myristate acetate (PMA). The calcium channel blockers, nifedipine and verapamil, and two putative inhibitors of calcium release from intracellular storage sites, 8-(N,N-diethylamine)-octyl-3,4,5-trimethoxybenzoate hydrochloride and ruthenium red, inhibited the release of NCA induced by ETX but had little effect on the release of NCA induced by OZ. However, depletion of extracellular calcium inhibited the release of NCA in response to both ETX and OZ. Calmodulin inhibitors, compound 48/80 and N-(6-aminohexyl)-1 naphthalenesulfonamide (W-7), inhibited the release of NCA in response to a variety of endotoxin concentrations. Lithium chloride, an inositol turnover inhibitor, inhibited the release of NCA in response to both ETX and OZ, but less attenuation was observed in the response to OZ. A protein kinase C inhibitor, dihydrosphingosine, inhibited the release of NCA in response to both ETX and OZ. Finally, A23187 and PMA stimulated the release of NCA and [3H]arachidonic acid independently and additively. These data suggest that the release of NCA from BECs in response to OZ may be predominantly mediated by inositol turnover and protein kinase C and that the release of NCA in response to ETX may be regulated by calcium influx and calcium release from intracellular storage sites, calcium-calmodulin activation, inositol turnover, and protein kinase C activation. Protein kinase C augmented the release of NCA and [3H]arachidonic acid independent of and in combination with calcium. These results may suggest the calcium and protein kinase C dependency of the release of NCA from BECs.

Ruptured aneurysm at the origin of duplication of the middle cerebral artery--case report

A 28-year-old male presented with a rare case of an aneurysm at the origin of duplication of the middle cerebral artery manifesting as subarachnoid hemorrhage. Preoperative angiography revealed duplication of the right middle cerebral artery and an aneurysm at its origin, which was successfully clipped. He was discharged with no neurological deficits. Congenital factors may be more important in the etiology of aneurysms associated with this anomaly.

[Effects of a beta 2-agonist, sodium cromoglycate, and an anticholinergic agent on hyperventilation-induced bronchoconstriction in sensitized rabbits]

Hyperventilation can induce bronchoconstriction in ovalbumin-sensitized rabbits. To investigate the roles of the beta-receptor parasympathetic nervous system and of chemical mediators in hyperventilation-induced bronchoconstriction (HIB), the effects of a beta 2-agonist, of sodium cromoglycate, and of an anticholinergic agent on HIB were studied. Rabbits were divided to four groups and treated as follows. Group 1: Control (n = 7, 0.9% saline); Group 2: Procaterol (n = 4, 50 micrograms/l); Group 3: Sodium cromoglycate (n = 4, 10 mg/ml); and Group 4: Ipratropium bromide (n = 6, 1 mg/ml). Each drug was inhaled for 1 min via an ultrasonic nebulizer. Then, for the eucapnic hyperventilation challenge, sensitized rabbits were mechanically hyperventilated for 15 min (120 breaths/min, tidal volume = 7 ml/kg) with dry air containing 5% CO2 at room temperature. Total lung resistance and dynamic compliance were measured before, and 0, 5, 15, and 30 min after hyperventilation. The mean percent change in resistance measured 5 min after the hyperventilation was +49% in group 1, -6% in group 2, +23% in group 3, and +1% in group 4. The changes in groups 2 and 4 were significantly less than in group 1 (p < 0.05). In conclusion, HIB is mainly caused by bronchial smooth muscle constriction, and chemical mediators and the parasympathetic nervous system may play important roles in the development of HIB in sensitized rabbits.

Topography of somatosensory evoked magnetic fields following posterior tibial nerve stimulation

The topography of somatosensory evoked magnetic fields (SEFs) following stimulation of the right and left posterior tibial nerves was investigated in 5 normal subjects (10 nerves). The main deflections N37m-P45m-N60m-P75m and their counterparts P37m-N45m-P60m-N75m were identified in the hemisphere contralateral to the stimulated nerve. Their equivalent current dipoles (ECDs) were located in the foot area of the primary sensory cortex (SI), probably in area 3b. Restricted minor deflections, P40m-N40m and N50m-P50m, were considered to be generated in area 1 in SI. As the generator sources of P37m-N37m, P40m-N40m and N45m-P45m were temporarily changed and interfered with each other, the direction of ECDs appeared to be rotated with the passage of time. Small middle-latency deflections, N100m-P100m, were clearly identified in 2 subjects. ECDs of these deflections were found in the second sensory cortex (SII), in both hemispheres, although they were clearer in the hemisphere contralateral to the stimulated nerve. In conclusion, short- and middle-latency SEFs are mainly generated in area 3b in SI contralateral to the stimulated nerve, and responses generated in area 1 of SI and SII affect the SEFs to some degree, but interindividual differences are large compared with SEFs evoked by upper limb stimulation.

Venous tumor thrombosis and cavernous transformation of the portal vein in a patient with gastric carcinoma

A case of extensive extra- and intrahepatic portal tumor thrombosis, with no metastatic foci in liver parenchyma, secondary to advanced gastric carcinoma in a 69-year-old man is reported. The portal tumor thrombosis was characterized by enlargement of the thrombosed segment of the vein, decreased density mass without intraluminal enhancement of the involved vein, nonvisualization of the portal venous branch in the involved lobe, and the so-called cavernous transformation of the portal vein. The surgically resected gastric specimen showed Borrmann type 3 advanced papillary adenocarcinoma. The portal tumor thrombus is presumed to have arisen from vascular invasion in the primary foci of gastric carcinoma, and then to have permeated the portal vein without invasion of liver parenchyma.

Somatosensory evoked magnetic fields after mechanical stimulation of the scalp in humans

Somatosensory evoked magnetic fields after mechanical stimulation by air-pressure-induced tapping which was applied to the forehead and occiput were examined in normal human subjects. The equivalent current dipole (ECD) of the initial magnetic field, 1M, was identified in the primary somatosensory cortex (SI) in the hemisphere contralateral to the stimulation. The ECD of the subsequent magnetic fields, 2M, was identified in bilateral second sensory cortices (SII). The ECD position of 1M in SI generated after the scalp stimulation was closely inferior to the hand area of the SI, which was consistent with the well-known somatotopic organization, 'homunculus'.

Characterization of the interaction of Raf-1 with ras p21 or 14-3-3 protein in intact cells

Several deletion mutants of Raf-1 were expressed with v-ras p21 or 14-3-3 protein in COS-7 cells and Sf9 cells and the interaction of Raf-1 with ras p21 or with 14-3-3 protein in intact cells was examined. Raf(1-135) (residues 1-135) and Raf(1-322) interacted with v-ras p21, but other deletion mutants such as Raf(136-322) or Raf(321-648) did not. Raf(1-322) interacted with 14-3-3 protein much more efficiently than Raf(321-648) did. While Raf(1-135) did not interact with 14-3-3 protein, Raf(136-322) did. These results clearly indicate that Raf-1 simultaneously interacts with both ras p21 and 14-3-3 protein through the distinct binding domains in intact cells.

Molecular cloning of cytidine monophospho-N-acetylneuraminic acid hydroxylase. Regulation of species- and tissue-specific expression of N-glycolylneuraminic acid

Cytidine monophospho-N-acetylneuraminic acid (CMP-NeuAc) hydroxylase, which is the key enzyme for the synthesis of N-glycolylneuraminic acid (NeuGc), has been purified from the cytosolic fraction of mouse liver, as described in our previous paper. The amino acid sequences of the purified CMP-NeuAc hydroxylase, and peptides obtained by lysylendopeptidase digestion, were used to synthesize specific oligonucleotide primers. A mouse cDNA clone of the enzyme was obtained by a combination of the polymerase chain reaction and rapid amplification of cDNA ends. The sequence of the clone contained an open reading frame coding for a protein of 577 amino acids with a predicted molecular mass of 66 kDa. The deduced sequence included the amino acid sequences obtained for the purified enzyme and peptides, and a complete match was obtained for 159 residues. The enzyme has neither a signal peptide sequence nor a membrane spanning domain, which is consistent with localization of the enzyme in the cytosol. Transfection of a cDNA construct to COS-1 cells increased the enzyme activity and the amount of NeuGc. Comparison of the sequence with GenBank data indicated that no similar sequence has been reported so far. Northern blot analysis of various mouse tissues with the enzyme cDNA as a probe indicated that expression of NeuGc is related to the level of CMP-NeuAc hydroxylase mRNA. On Southern blot analysis with the same probe, cross-hybridizing bands were detected in the human and fish genomes.

Bradykinin stimulates bronchial epithelial cells to release neutrophil and monocyte chemotactic activity

In the present investigation, we evaluated the potential of bradykinin (BK), histamine, and serotonin to induce the release of neutrophil and monocyte chemotactic activity (NCA and MCA) from bronchial epithelial cells (BEC). BK significantly stimulated BEC to release NCA and MCA in a dose- and time-dependent manner. Histamine weakly but significantly induced the release of both NCA and MCA in a similar fashion. Serotonin did not stimulate BEC. Checkerboard analysis showed that the NCA and MCA released in response to BK were chemotactic. Molecular-sieve column chromatography by Sephadex G-75 revealed that BK induced a single low-molecular-weight peak (approximately 400 Da) for both NCA and MCA. The releases of NCA and MCA in response to BK and histamine were inhibited by lipoxygenase inhibitors (P < 0.01). The released NCA was inhibited by leukotriene B4 (LTB4) receptor antagonist (P < 0.01) and was slightly inhibited by platelet-activating factor receptor antagonist. LTB4 was increased in BK-stimulated BEC supernatant (P < 0.01). BK B2-receptor antagonist attenuated the release of NCA and MCA. These data suggest that BK and histamine may stimulate BEC to release NCA and MCA and may modulate neutrophil and monocyte recruitment into the airways in patients with asthma.

rBPI23 attenuates endotoxin-induced cardiovascular depression in awake rabbits

We determined the effect of a recombinant N-terminal fragment of bactericidal/permeability-increasing protein (rBPI23) on hemodynamic and renal sympathetic responses to lethal endotoxemia in unanesthetized rabbits. Endotoxin was continuously infused intravenously (200 micrograms/kg/h) over 120 min with simultaneous infusion of either rBPI23 (3 mg/kg bolus followed by 6 mg/kg/h over 120 min; n = 6) or thaumatin (the same dose as rBPI23), a control cationic protein with a molecular weight and isoelectric point similar to that of rBPI23 (n = 9). Tissue blood flow was also determined using colored microspheres to the left ventricle, renal cortex, liver, and skeletal muscle. Seven of nine animals treated with endotoxin and thaumatin died between 45 and 120 min after start of the infusion, whereas all animals with rBPI23 treatment were alive throughout the entire 2 h experimental period. A transient increase in renal sympathetic nerve activity was observed in the thaumatin-treated animals followed by sympathoinhibition with concomitant decreases in heart rate, blood pressure, and cardiac output. Tissue blood flow to all measured organs gradually decreased in animals receiving endotoxin and thaumatin. However, rBPI23 abolished all these deleterious responses to endotoxin. In conclusion, rBPI23 attenuates the acute lethal sympathoinhibitory and hemodynamic effects of endotoxemia in awake rabbits.

Effects of thromboxane A2 analogue on vascular resistance distribution and permeability in isolated blood-perfused dog lungs

This study was designed to determine the effects of thromboxane A2 (TxA2) on the distribution of vascular resistance, lung weight, and microvascular permeability in isolated dog lungs perfused at a constant pressure with autologous blood. The stable TxA2 analogue (STA2; 30 micrograms, n = 5) caused an increase in pulmonary capillary pressure (Pc) assessed as double-occlusion pressure to 14.0 +/- 0.4 mmHg from the baseline of 7.9 +/- 0.3 mmHg with progressive lung weight gain. Pulmonary vascular resistance increased threefold exclusively due to pulmonary venoconstriction. Pulmonary venoconstriction was confirmed in lungs perfused in a reverse direction from the pulmonary vein to the artery (n = 5), as evidenced by marked precapillary vasoconstriction and a sustained lung weight loss. Furthermore, in lungs perfused at a constant blood flow (n = 5), STA2 also caused selective pulmonary venoconstriction. Vascular permeability measured by the capillary filtration coefficient and the isogravimetric Pc at 30 and 60 min after STA2 infusion did not change significantly from baseline in any lungs studied. Moreover, elevation of Pc by raising the venous reservoir of the intact lobes (n = 5) to the same level as the STA2 lungs caused a greater or similar weight gain compared with the STA2 lungs. Thus, we conclude that TxA2 constricts selectively the pulmonary vein resulting in an increase in Pc and lung weight gain without significant changes in vascular permeability in isolated blood-perfused dog lungs.

Pain-related magnetic fields following painful CO2 laser stimulation in man

The initial somatosensory evoked magnetic fields following painful heat stimulation by CO2 laser beam applied to the upper and lower limb were investigated in normal subjects. The main deflections, 'Pain MA' and 'Pain ML' following the arm and leg stimulation, respectively, were identified in the bilateral second sensory cortices (SII). The onset latencies of Pain MA and Pain ML were approximately 150 and 200 ms, respectively. No consistent equivalent current dipole was found in other areas including the primary sensory cortex in each hemisphere. Therefore, we consider that neurons in the bilateral SII are initially activated following painful heat stimulation.