Potential applications of intracardiac echocardiography in the assessment of the aortic valve from the right ventricular outflow tract

Intracardiac echocardiography (ICE) is a developing technology and a promising method for visualizing intracardiac structures. However, its applications are currently limited to guidance during mitral valvuloplasty, catheter ablation, or electrophysiologic examination. The goal of this study was to observe the aortic valve, measure the annular diameter of the valve by ICE through a right-sided approach, and compare the results by ICE with those by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE). We studied 18 patients (9 men, 9 women, aged 19 to 72 years) with various heart diseases, including 15 patients with mitral or aortic valvular disease. An imaging catheter was advanced through a long sheath into the outflow tract of the right ventricle. We obtained good longitudinal views of the aortic valve in all patients. Two of the 18 patients had poor image quality by TTE. The annular diameter by ICE correlated more closely with TEE than with TTE. In conclusion, right-sided ICE is a safe, simple, and useful procedure for observing the aortic valve during cardiac catheterization without additional discomfort in the patients. Right-sided ICE is superior to TTE in observing the aortic valve and measuring the annular diameter of the valve. The annular diameter can be measured by ICE as precisely as by TEE.

Influence of pregnancy on the development of various gastric lesions in rats

The influence of pregnancy, and to some extent lactation, on various gastric lesions in rats were studied. Shay ulceration and gastric lesions induced by cold-restraint stress and ulcerogenic agents, such as acetylsalicylic acid (ASA), reserpine, or epinephrine, in rats were significantly aggravated by pregnancy (day 20 of pregnancy). Gastric hypersecretion, which was observed during pregnancy in pylorus ligation preparation, appears to contribute to the mechanism of aggravation of gastric lesions. ASA induced a marked back-diffusion of acid in pregnant rats which might resulted in the aggravation of ASA-induced gastric lesions. In contrast, histamine-induced gastric lesions were markedly inhibited according according to the progress of pregnancy but after 10 days' lactation returned to the level seen in nonpregnant rats. The histaminase inhibitor aminoguanidine strongly aggravated the histamine-induced gastric lesions in pregnant rats as compared with the non-pregnant ones.

Impaired duodenal bicarbonate secretion in diabetic rats. Salutary effect of nitric oxide synthase inhibitor

We previously reported the impaired HCO3- secretion and the increased mucosal susceptibility to acid in the duodenum of streptozotocin (STZ)-induced diabetic rats. In this study, we investigated the salutary effect of the NO synthase inhibitor L-NAME (NG-nitro-L-arginine methyl ester) on these changes and compared it with those of insulin. Animals were injected streptozotocin (STZ: 70 mg/kg, ip) and used after 1, 3-4, and 5-6 weeks of diabetes with blood glucose levels of > 300 mg/dL. Under urethane anesthesia the HCO3- secretion was measured in the proximal duodenal loop using a pH-stat method and by adding 10 mM HCl. L-NAME (20 mg/kg x 2) or insulin (4 units/rat) was administered sc for 4-5 weeks, starting 1 week after STZ treatment. The duodenal HCO3- secretory responses to various stimuli such as mucosal acidification (10 mM HCl for 10 min), 16,16-dimethyl prostaglandin E2 (dmPGE2: 10 micrograms/kg, i.v.), and vagal stimulation (0.5 mA, 2 ms, 3 Hz) were significantly decreased in STZ-treated rats, depending on the duration of diabetes. Repeated administration of L-NAME, starting from 1 week after STZ treatment, significantly reduced blood glucose levels toward normal values and restored the HCO3- responses to various stimuli in STZ rats, the effects being similar to those observed after supplementation of insulin. Diabetic rats developed duodenal lesions after perfusion of the duodenum with 150 mM HCl for 4 h, but this ulcerogenic response was significantly inhibited by the repeated treatment with L-NAME as well as insulin. We conclude that L-NAME is effective in ameliorating hyperglycemic conditions in STZ-diabetic rats, similar to insulin, and restores the impaired HCO3- secretion and the increased mucosal susceptibility to acid in diabetic rat duodenums.

The Vdelta1 T cell receptor repertoire in human nasal mucosa

The gamma/delta T cells play important roles as the first line of defence in mucosal immunity. Vdelta1 bearing T cells comprise the major population of gamma/delta T cells in the human nasal mucosa. Recently, it was reported that certain receptors are predominant at given anatomical locations. The purpose of this study was to elucidate the gamma/delta T-cell receptor repertoire in human nasal mucosa. Nasal epithelia were scraped and peripheral blood were obtained from three healthy volunteers. We performed reverse-transcription polymerase chain reaction (RT-PCR) analysis and characterized the junctional sequences of Vdelta1 T-cell receptor (TCR) transcripts. Vgamma and Vdelta gene usage in intraepithelial lymphocytes (IELs) in right and left nasal mucosa were almost the same, but they were different from those in peripheral blood lymphocytes (PBLs). The VDJ sequence of nasal Vdelta1 T-cell receptor transcripts showed diversity and were different for each individual. Vdelta1 in the IELs were rearranged to Jdelta1 and Vdelta1 in the PBLs were rearranged not only to Jdelta1 but also to Jdelta3. Vdelta1 sequences in the IELs in the nasal mucosa showed no overlap with those in the PBLs. These results indicate that gamma/delta T cells in the nose are organ specific lymphocytes.

Dobutamine-stress electrocardiographically gated positron emission tomography for detection of viable but dysfunctional myocardium

PURPOSE

This study was performed to determine whether low-dose dobutamine stress electrocardiography (ECG)-gated fluorine-18 fluorodeoxyglucose (FDG)-positron emission tomography (PET) can assess wall motion and identify myocardium without contractile reserve despite preserved FDG uptake.

METHODS

Fifty-three patients with myocardial infarction and normal sinus rhythm underwent ECG-gated FDG-PET and transthoracic echocardiography. Wall motion of 10 segments of the left ventricle was graded as normal, hypokinetic, or akinetic/dyskinetic.

RESULTS

In 365 (76%) of 480 segments, assessment of wall motion was concordant between the 2 modalities. In 30 patients dobutamine-stress ECG-gated FDG-PET was performed. In 13 (50%) of 26 dysfunctional segments with normal FDG uptake, 16 (36%) of 44 dysfunctional segments with mildly reduced FDG uptake and 12 (25%) of 48 dysfunctional segments with moderately reduced FDG uptake, wall motion was improved by dobutamine infusion.

CONCLUSION

Assessment of left ventricular wall motion with ECG-gated FDG-PET is feasible, and dobutamine stress ECG-gated FDG-PET can simultaneously identify metabolic viability and contractile reserve.

Acid secretory and duodenal ulcerogenic responses induced by mepirizole in anesthetized rats. Relation to body temperature

The role of body temperature in the acid stimulatory mechanism by mepirizole, a duodenal ulcerogen, was investigated in urethane-anesthetized rats. Subcutaneous administration of mepirizole (60 and 200 mg/kg) increased acid secretion in a dose-dependent manner and resulted in duodenal lesions within 8 hr. The acid secretory and ulcerogenic responses induced by mepirizole were inhibited completely by vagotomy and significantly reduced by subcutaneous pretreatment with atropine (1 mg/kg), hexamethonium (10 mg/kg), or clonidine (1 mg/kg). During anesthesia, body temperature was decreased to 34 degrees C in control rats but further reduced to 31 degrees C after administration of mepirizole. When body temperature was maintained at 36 degrees C during a test period, mepirizole caused significantly less effect on acid secretion and produced less damage in the duodenum. In addition, intracisternal administration of antiserum of thyrotropin-releasing hormone (TRH: 5 mu1/rat) also significantly inhibited acid hypersecretion and development of duodenal lesions in response to mepirizole. When acid output induced by mepirizole was plotted against duodenal lesion score from one group to another, a significant linear relationship was found between these two values (r = 0.814, P < 0.05). We conclude that mepirizole induced vagally mediated acid secretion and duodenal lesions in anesthetized rats. These responses may occur centrally in association with lowering of body temperature, which potentiates the acid stimulatory effect of mepirizole, probably through a TRH-dependent mechanism.

Effects of TY-10957, a stable PGI2 derivative, on gastroduodenal lesions and secretory responses in the rat

The effects of TY-10957, a stable PGI2 derivative, on gastroduodenal lesions and secretory responses were examined in rats and compared with those of ornoprostil, a PGE1 derivative. Orally administered TY-10957 dose dependently prevented gastric lesions induced by ethanol/HC1 (60% ethanol in 150 mM HCl) and duodenal ulcers induced by mepirizole (200 mg/kg); a significant effect was obtained at 3 micrograms/kg or greater in the former and at 300 micrograms/kg in the latter. Intraduodenally administered TY-10957 had minimal effects on gastric acid secretion, and at the highest dose (300 micrograms/kg) both the basal acid output and that stimulated by histamine (20 mg/kg) were significantly reduced by about 40%. TY-10957 (30-300 micrograms/kg s.c.) produced a marked increase of alkaline secretion in both stomach and duodenum of anesthetized rats, and these effects were significant at 30 micrograms/kg in the stomach and at 100 micrograms/kg in the duodenum. On the other hand, ornoprostil produced a potent and significant inhibition against ethanol/HCl-induced lesions (greater than 1 microgram/kg), but had no effect on mepirizole-induced duodenal ulcers. This PGE1 derivative had no influence on both basal and stimulated acid secretion and did not significantly affect alkaline secretion even at 100 micrograms/kg. These results suggest that TY-10957 has a protective action on both gastric and duodenal mucosa. The mechanism of duodenal antiulcer effect may involve both inhibition of acid and stimulation of alkaline secretion, while the gastroprotective action of this agent may be attributed to other factors.

First observation of clusters for solvated tropylium ions

We have first observed clusters for solvated tropylium ions (Tr+(ROH)n) which were isolated from ROH-CH3CN (1:1 by vol.; R = Me, Et, and Prn) solutions by using a specially designed mass spectrometer and found the clear-cut essential features concerning the solvation structure around Tr+.

Optical imaging of excitation propagation evoked by stimulation to the trigeminal caudalis

The present study reports on a characteristic spatio-temporal propagation of differential fluorescent images in the rat brain stem slice by a high-speed optical imaging technique. Coronal or sagittal slices were stained with a voltage-sensitive dye RH-414, and the superficial layer of the trigeminal caudalis (Vc) was then electrically stimulated. The marginal layer and substantia gelatinosa showed larger rostrocaudal excitation than coronal, despite a lack of tract stimulation expansion in either direction. A perfusion of 0.5 micromol/l TTX, not 10 micromol/l CNQX suppressed these propagations. These findings suggest that the superficial layer of Vc has spatial differences in neuronal excitation propagation, as evidenced by morphological observations that dendrites in the superficial layers extend in the rostrocaudal direction.

Effect of allergen-specific immunotherapy on interleukin-4, interleukin-5 and interferon-gamma mRNA expression in the nasal mucosa of rats with allergic rhinitis

To elucidate the mechanism of immunotherapy, we tested the effect of ovalbumin and ovalbumin-pullulan conjugate immunotherapy on the expression of interleukin (IL)-4, IL-5 and interferon-gamma (IFN-gamma) mRNA in the nasal mucosa of sensitized rats. Forty-five rats were injected with ovalbumin intraperitoneally on three consecutive days and later were exposed to ovalbumin aerosol. The rats were injected intradermally, on six consecutive days, with saline, ovalbumin or ovalbumin-pullulan conjugate. Later, nasal mucosa was obtained and reverse transcription-polymerase chain reaction (RT-PCR) was performed. Nasal responses and specific immunoglobulin E (IgE) were measured. Although the immunotherapy significantly decreased nasal airway resistance, dye leakage and histamine content in nasal irrigation after allergen challenge, no significant difference was found in IL-4 and IL-5 mRNA expression or in specific IgE level among the three groups. We conclude that in this allergic model, the improvement of nasal responses after immunotherapy was the result of a mechanism other than decrease of T-helper 2 (Th2) cytokines.

Management of acute chylothorax with hydrops fetalis diagnosed in the third trimester of pregnancy

A fetus with large pleural effusion and hydrops fetalis diagnosed in the third trimester was successfully treated with prompt vaginal delivery followed by drainage of the pleural cavity, after confirmation of congenital chylothorax and re-expansion of the lung with prenatal thoracentesis.

Cyclic GMP accumulation by atriopeptins in cultured rat renal and vascular smooth muscle cells

To evaluate the role of cyclic guanosine monophosphate (cGMP) in the vascular and renal action of atrial natriuretic peptide (ANP), we compared the effects of atriopeptins (APs) on cGMP accumulation in cultured cells from rat mesenteric vascular smooth muscle (VSM), glomerular mesangium (GM) and renal papillary collecting tubule (RPCT), and also evaluated the relationship between renal sodium or water excretion and urinary cGMP in AP-infused rats. Both AP I and AP III increased intracellular cGMP levels dose-dependently in all types of cells, while they did not affect intracellular cAMP levels or prostaglandin synthesis. AP III was 100 times more potent than AP I. The magnitude change in cGMP levels was largest in GM cells. The sensitivity of VSM and GM cells to AP III were greater than that of RPCT cells. There were significant positive relationships between urinary excretion of sodium or water and that of cGMP levels in AP-infused rats. These results may suggest that GM and VSM cells are the principal targets for ANP to stimulate cGMP synthesis and, possibly, to exert the renal sodium and water excretion, and also support the hypothesis that cGMP mediates the cellular action of ANP.

Multivariate analysis using a linear discriminant function for predicting the prognosis of congestive heart failure

Some of cases of congestive heart failure (CHF) are intractable or refractory and respond poorly to conventional treatment. We have examined factors which may influence the clinical course and prognosis. The subjects were 114 hospitalized patients with CHF. Of these, 77 had a good response to treatment and were classified as the curative group (Group C) while the remaining 37 who were difficult to treat, including those with poor prognosis, were designated the refractory group (Group R). Of the various clinical background factors including the findings of laboratory and other examinations, the following 8 variables made a significant contribution to differentiation between the 2 groups: 1) heart rate (X1), 2) hemoglobin content (X2), 3) serum K (X3), 4) serum total protein (X4), 5) A/G (X5), 6) BUN (X6), 7) grade of hepatomegaly (X7), and 8) number of previous CHF episodes (X8). The linear discriminant function represented by the following equation using these 8 variables showed an excellent result in differentiating the 2 groups. Y = - 9.64 - 0.0686X1 + 0.345X2 + 1.351X3 + 1.513X4 + + 1.988X5 - 0.0876X6 - 0.792X7 - 0.737X8. When Y value is over 0, Group C is judged. When Y value is under 0, group R is judged. We concluded that the discriminant equation covering these 8 factors is a useful means of predicting the prognosis in CHF and the response to treatment.

Effects of metabolically ischemic, but viable, myocardium on QT dispersion in patients with acute myocardial infarction: a study with resting I-123-BMIPP/thallium-201 myocardial single-photon emission computed tomography

In chronic Q-wave myocardial infarction, QT dispersion is closely correlated with infarct size, but this correlation has not been evaluated for acute myocardial infarction (AMI). The effects of abnormal fatty acid metabolism on QT dispersion were examined in 123 patients with AMI who underwent resting iodine-123-15-iodophenyl 3-methyl pentadecanoic acid (BMIPP)/thallium-201(201Tl) myocardial single photon emission computed tomography (SPECT) and electrocardiographic analysis in the subacute phase. The relationship between BMIPP and 201Tl was defined as match when the total defect score for BMIPP was equal to or smaller than that for 201Tl, and as mismatch when the total defect score for BMIPP was larger than that for 201Tl. Twenty-six patients (21%) demonstrated BMIPP-201Tl match and 97 (79%) demonstrated mismatch. Infarct size was closely correlated with QT dispersion (r=0.67, p<0.001) in patients with BMIPP-201Tl match, but weakly correlated (r=0.30, p<0.005) in patients with BMIPP-201Tl mismatch. For small infarctions, QT dispersion was significantly larger in patients with BMIPP-201Tl mismatch than in those with BMIPP-201Tl match (62+/-24 ms vs 41+/-18 ms, p=0.03), but did not differ between the 2 groups for large infarctions. This study shows that QT dispersion is influenced by infarct size and by the presence of metabolically ischemic but viable myocardium in patients with AMI.

Effects of the duodenal ulcerogens, mepirizole and cysteamine, on gastric motility and emptying in rats

Mepirizole (60 and 200 mg/kg, s. c.) and cysteamine (100 and 300 mg/kg, s. c.) markedly inhibited gastric motility in fasted rats. The inhibition caused with the low dose (non-ulcerogenic) of each agent reverted to control levels within 6 h. With high doses (ulcerogenic), however, the inhibition persisted for more than 9 h, and returned to control levels 12 h later. Gastric emptying of liquids was significantly delayed with ulcerogenic and non-ulcerogenic doses of the agents. Delayed emptying (gastric contents) persisted for 12 h with ulcerogenic doses, The pathogenetic relevance of this prolonged inhibition of gastric motility and emptying to ulcerogenecity was considered.