The effects of calcitonin gene-related peptide on tracheal smooth muscle of guinea-pigs in vitro

1. The effect of calcitonin gene-related peptide (CGRP) on airway smooth muscle is controversial. The aim of this study was to determine whether the action of CGRP on tracheal strips of guinea-pigs is modulated by epithelium and whether this peptide-induced action involves other mediators including nitric oxide (NO) and endothelin (ET)-1. 2. CGRP produced a weak dose-dependent increase in guinea-pig tracheal tension in vitro (-logEC50 = 8.5 +/- 0.1, maximum contraction = 8.3 +/- 1.2% of 50 mM KCl-induced contraction, n = 6). In epithelium-depleted preparations, CGRP (10(-7) M)-induced contraction was significantly potentiated from 9.0 +/- 1.9% to 41.1 +/- 6.0% (n = 6). 3. L-NG-nitro-arginine methyl ester (L-NAME, 10(-4) M), which inhibits NO synthesis, enhanced the contractile response to CGRP from 9.0 +/- 1.9% to 31.2 +/- 1.1% (n = 6). Indomethacin (10(-5) M) also enhanced the response to CGRP, although the effect was weak (13.4 +/- 3.2%, n = 6). 4. Anti-ET-1 serum changed the CGRP-induced contraction into a relaxation. After incubation of the trachea with ET-1 (10(-7) M) to attenuate ET-1-induced responses, the CGRP-induced contraction also changed into a relaxation. BQ-123 (an ETA receptor antagonist) and BQ-788 (an ETB receptor antagonist) caused the same conversion of the CGRP response, from contraction to relaxation, although the relaxing effect elicited by BQ-788 was more potent than that by BQ-123. Maximum inhibitory responses were -31.0 +/- 3.3% and -13.0 +/- 2.3% of 50 mM KCl-induced contraction, respectively (n = 6). 5. In primary culture, guinea-pig tracheal epithelial cells released ET-1, and CGRP (10(-5) M) significantly increased the release of ET-1. 6. These data suggest that the action of CGRP is modulated by airway epithelium and this mechanism involves the release of NO and ET-1. Especially, the majority of contractile action elicited by CGRP consists of an action of ET-1 via the predominant ETB receptor.

The vibrational mode of the tibia and assessment of bone union in experimental fracture healing using the impulse response method

This study attempts to clarify the use of the impulse response method in the assessment of fracture healing. The vibrational mode as well as the effect of simulated callus consolidation on the vibrational parameters of excised human tibia were studied. Two separate vibrations were found, one vibrating strongly in the lateral direction and the other vibrating weakly in the antero-posterior direction. The ability to identify the primary vibrational mode in the lateral direction would make the impulse response method suitable for use in clinical practice. The callus consolidation process was simulated by the sequential consolidation of an adhesive material in an experimentally produced fracture gap. The change in hardness of the epoxy was found to correlate well with the change of resonant frequency of the bone. The resonant frequency demonstrated a steady increase during the initial phase of consolidation of the adhesive, up to about 40% of its final hardness. With the addition of various constructs for fracture fixation to the in vitro model such as a plate, Ender's pins, a Russell-Taylor intramedullary nail, or an Orthofix external fixator, the relationship between the consolidation of the 'callus' and the change in resonant frequency of the bone was not disturbed.

Three-dimensional labeling program for elucidation of the geometric properties of biological particles in three-dimensional space

For all biological particles such as cells or cellular organelles, there are three-dimensional coordinates representing the centroid or center of gravity. These coordinates and other numerical parameters such as volume, fluorescence intensity, surface area, and shape are referred to in this paper as geometric properties, which may provide critical information for the clarification of in situ mechanisms of molecular and cellular functions in living organisms. We have established a method for the elucidation of these properties, designated the three-dimensional labeling program (3DLP). Algorithms of 3DLP are so simple that this method can be carried out through the use of software combinations in image analysis on a personal computer. To evaluate 3DLP, it was applied to a 32-cell-stage sea urchin embryo, double stained with FITC for cellular protein of blastomeres and propidium iodide for nuclear DNA. A stack of optical serial section images was obtained by confocal laser scanning microscopy. The method was found effective for determining geometric properties and should prove applicable to the study of many different kinds of biological particles in three-dimensional space.

Range-resolved bistatic imaging lidar for the measurement of the lower atmosphere

A bistatic imaging lidar system using a cooled CCD camera as a detector has been developed for the observation of aerosols, fog, and clouds in the lower atmosphere, especially within several hundred meters of the Earth's surface. Theoretical discussion showed that the received signal does not depend on the measured range. The potential of the bistatic imaging lidar was confirmed through results of nighttime observations of atmospheric phenomena up to 300 m. A range-resolved profile was obtained without scanning and with a very short time resolution, within 1 min.

Granulocyte transfusion: stimulation of low dose granulocyte colony-stimulating factor in donors for leukapheresis

In order to assess the clinical utility of granulocyte transfusions (GT), the stimulating effects of donor granulopoiesis for GT therapy were examined using either low dose recombinant human granulocyte colony-stimulating factor (rhG-CSF) or dexamethasone (DEX). The increment of leukocytes, polymorphonuclear cells (PMN) and monocytes in the subjects stimulated with rhG-CSF (0.7 microgram/kg SC) surpassed each increment in those with DEX alone (1 mg PO). The lymphocyte counts after DEX stimulation decreased in contrast to those after G-CSF stimulation. This dose of G-CSF did not enhance the priming effects on the superoxide release from PMN. The serum levels of lysozyme, but not of lactate dehydrogenase, in G-CSF stimulated donors were higher than those in DEX-treated donors. The serum macrophage/monocyte-colony stimulating factor (M-CSF) levels in DEX stimulation were lower than in either G-CSF stimulation or no stimulation. The net yield of the PMN in GT on G-CSF stimulation was practically larger than that on DEX stimulation. One of the two patients who received GT collected by DEX stimulation died of aspergillosis. Two of the five patients who received PMN mobilized by G-CSF died of fungal infections or necrotizing fasciitis, although two of the remaining patients overcame severe bacterial infections. These results suggest that low dose G-CSF effectively and safely mobilizes a sufficient quantity of PMN from GT-donors without excessive superoxide generation from the transfused cells. This low dose G-CSF stimulation may be substituted for conventional DEX stimulation for GT.

Hepatitis B and C virus serologies among Japanese Americans with hepatocellular carcinoma

A cohort of 5924 Japanese American men was examined between 1967 and 1970 for hepatocellular carcinoma (HCC). By 1992, 24 incident cases of HCC were histologically confirmed in the group. Frozen serum samples from the 24 men with HCC and 72 age-matched controls were tested for hepatitis B surface antigen (HBsAg), antibodies to hepatitis B core antigen, antibodies to HBsAg, and antibodies to hepatitis C virus. HBsAg was detected in 15 (62.5%) of 24 HCC cases compared with 2 (2.8%) of 72 controls (odds ratio, 43.0; 95% confidence interval, 5.7-325.5). None of the cases and only 1 control had antibody to hepatitis C virus. This study demonstrates a strong association between hepatocellular carcinoma and hepatitis B virus infection, but not with hepatitis C virus infection, among men of Japanese ancestry in Hawaii.

Involvement of endothelins in immediate and late asthmatic responses of guinea pigs

To explore the pathophysiological roles of endothelin isopeptides and receptor subtypes in asthmatic responses, a guinea pig model for asthma was used to test the effects of antiendothelin (ET) serum and selective ET receptor antagonists for antigen-induced specific airway conductance changes as measured by whole-body plethysmography. In this model, all of the animals so far tested demonstrated both the immediate and late asthmatic responses. Although preimmune serum had no apparent effects, anti-ET antiserum suppressed the maximal reduction of specific airway conductance in both the immediate and late asthmatic responses, which suggested that ET(s) are involved in the pathophysiology of both the immediate and late asthmatic responses. The ETB selective antagonists, BQ788 and RES701-1, blocked the immediate asthmatic response but not the late asthmatic response, whereas the ETA antagonists, BQ123 and (Shionogi) 97-139, suppressed only the late asthmatic response without influencing the immediate asthmatic response. In vitro constrictive responses of isolated tracheas and bronchi to ET1 were inhibited mainly by BQ123 and BQ788, respectively, which suggested that distribution of ETA and ETB receptors for bronchoconstriction are topographically distinct along airways. Furthermore, thromboxane A2 and platelet activating factor (PAF) antagonists were effective in suppressing the late asthmatic response but not the immediate asthmatic response. Taken together, our present observations suggest that ET(s) influences pulmonary functions by constricting airway smooth muscle via ETB receptors during the immediate asthmatic response and by modulating pulmonary inflammation via ETA receptors during the late asthmatic response, respectively.

[Ultra-low-dose spiral (helical) CT of the thorax: a filtering technique]

To reduce the radiation dose from spiral (helical) CT, a custom-made aluminium filter was installed in the X-ray tube and a reduction of effective tube current was attempted. A pronounced reduction of effective tube current, namely, 6 and 3 mA, was achieved with 26 and 37 mm thick aluminium filters, respectively. Visualization of normal lung structure was accomplished with both 6 and 3 mA settings. However, images of 3 mA failed to delineate mediastinal structures because of marked beam hardening resulting from the bone structure of the thoracic inlet. Six mA was considered the lowest dose setting of spiral (helical) CT of the thorax that could be used for lung cancer screening.

Use of intravenous dofetilide in atrial flutter with hemodynamic instability

Paroxysmal atrial flutter is a drug-resistant supraventricular tachyarrhythmia that is often accompanied by hemodynamic instability due to an excessive ventricular response. We report here a case of atrial flutter with 1:1 atrioventricular conduction, in which we were able to rescue the patient from a state of cardiogenic shock by using intravenous dofetilide, a new class III antiarrhythmic agent. Dofetilide was suitable for the treatment because it immediately increased atrioventricular nodal refractoriness without any negative inotropic action.

Assessment of fracture healing in the tibia using the impulse response method

The resonant frequency of a long bone as measured using the impulse response method (IRM) can reflect the bending rigidity of the bone. A study was performed using IRM to quantitatively assess fracture healing in 67 tibial fractures. A temporary decrease in resonant frequency early in the treatment course was found in 55.6% of tibias, most frequently in the cases treated by external fixation (83.3%) and the AO plate (80%). The resonant frequency also decreased temporarily following the removal of the fixation devices in 76% of the tibias where they were removed. The resonant frequency of the fractured tibia at the final follow-up exceeded that of the contralateral side in 18% of tibias, approached within 20 Hz in 11.5%, and did not reach within 20 Hz in 70.5%. A questionnaire on the effectiveness of the IRM examination in the treatment of the tibia fractures was completed by the treating orthopaedic surgeons. The IRM examinations were found to be very useful in 58.2% of cases, useful in 31.3%, and useless in 10.4%. Thus, IRM examinations are most helpful when they are able to detect the change in bending rigidity early in the treatment of tibia fractures.

The practical aspects of quality assurance in Good Laboratory Practice studies in an emergency situation

In this report, the damage and countermeasures taken in relation to the Great Hanshin Earthquake are described. We report on the measures taken to counter damage in affected Good Laboratory Practice (GLP) studies by citing concrete examples. Case A: the testing facility was not affected, but a regulatory inspection had been scheduled for this day. Fortunately, official inspectors had reached the facility on schedule. Case B: The building for toxicology experiments was destroyed. Fortunately, most of the GLP-compliant experiments had been completed except one, the preparation of histological samples that was the last stage of the experiment. We asked the regulatory authority for appropriate countermeasures. The answer was that an inspection of the study could be conducted if an inspection is judged to be necessary. Case C: A necropsy was scheduled on this day. The study director decided that the necropsy should be postponed at least 1 week until he could secure the number of researchers needed to conduct the necropsy. Case D: The facility in Itami was destroyed. The facility was closed and the animals were moved to Kobe. The animal facility in Kobe was not affected, but because water supply stopped for 3 days, stocked water was used. Case E: Damage to computer systems in Kinki area was reported. Numerous computers fell from desks or were damaged from the impact shock. With the exception of a few, most of the damaged computers were repaired.

[Increased production of nitric oxide in the immediate and late asthmatic responses in models of guinea pig experimental asthma]

Nitric oxide is produced in mammalian airways by constitutive and inducible nitric oxide synthase, and endogenous nitric oxide can be detected as exhaled gas. Patients with asthma have large numbers of airway epithelial cells and inflammatory cells that contain nitric oxide synthase, and nitric oxide levels in exhaled air are high during immediate asthmatic responses. To examine the dynamics of nitric oxide synthase in the tracheas of guinea pigs, cumulative dose-response studies of 5-HT were done on tracheal strips, in the presence or absence of arginine and its analogues. This assay indicated that relative the activity of nitric oxide synthase was greater 6 hr after the challenge than immediately after, which suggests that nitric oxide is involved in the pathogenesis of bronchial asthma attacks.

Tubulointerstitial injury induced in rats by a monoclonal antibody that inhibits function of a membrane inhibitor of complement

The kidney widely expresses membrane-associated complement regulatory proteins (membrane inhibitors of complement). The aim of this work was to evaluate the roles of these molecules in rat kidneys in vivo. To suppress functions of rat membrane inhibitors of complement, two mAbs, 512 and 6D1, were used. 5I2 and 6D1 inhibit functions of membrane inhibitors of complement at C3 level (rat Crry/p65) and C8/9 level (rat CD59), respectively. F(ab')2 fragment of 5I2 or 6D1 was perfused in the left kidneys, and perfusate was discarded from the renal vein. After perfusion, the left kidneys were connected to systemic circulation. In rats perfused with 5I2, mouse IgG was found in glomeruli, peritubular capillaries, vascular bundles, and tubules 15 min after recirculation. Binding of C3 and C5b-9 was evident in these areas. 1 d after perfusion with 5I2, cast formation, dilatation of tubular lumen, and tubular cell degeneration were observed. At day 4 through day 7, significant mononuclear cell infiltration and proximal tubule damage were observed. These changes were completely prevented by complement depletion. Rats perfused with 6D1 showed the binding of mouse IgG in the similar areas as 5I2, but C3 or C5b-9 deposition was not observed. Rats perfused with 6D1 or vehicle only did not show any pathology in the left kidneys. These results suggest that rat Crry/p65 plays protective roles against spontaneously occurring indiscriminate attack to tubulointerstitial tissues by autologous complement and that rat Crry/p65 is one of the important factors to maintain normal integrity of the kidney in rats.

Purification method for alpha-1-acid glycoprotein with subsequent high-performance liquid chromatographic determination of monosaccharides in plasma of healthy subjects and patients with renal insufficiency

A simple purification method for human plasma alpha-1-acid glycoprotein (AAG) using an ion-exchange and hydroxyapatite column was developed. The recovery of the method was found to be high. We also improved a determination method for N-acetylneuraminic acid and monosaccharides in the carbohydrate moiety of AAG by using an ion-exchange column and pulse-amperometric detection. By this method, a composition analysis of the carbohydrate moiety of AAG (N-acetylneuraminic acid, fucose, N-acetyl glucosamine, galactose and mannose) was possible with 1.0 ml of plasma. We compared these carbohydrate concentrations in the AAG of patients with renal insufficiency with those of healthy subjects. In the AAG of the patients, the concentrations of N-acetylglucosamine, galactose and mannose were significantly higher than those in the AAG of the healthy subjects.

Changes in the binding capacity of alpha-1-acid glycoprotein in patients with renal insufficiency

The elevation of alpha-1-acid glycoprotein (AAG) concentration and the binding characteristics of disopyramide (DP) to AAG in patients with renal insufficiency were investigated. The serum AAG concentration and protein binding of DP in patients were significantly greater than those in healthy subjects. However, in both the serum and the purified AAG, Scatchard analysis showed that the number of binding sites per molecule of AAG in patients was significantly lower than that in healthy subjects, although there was no difference in the dissociation constant (Kd). These results suggest that the AAG induced in renal insufficiency is qualitatively different from normal AAG. Moreover, the change of the unbound DP fraction when DP concentration was increased was larger in the patients than in the healthy controls. Therefore, monitoring of the unbound DP would be important for therapeutic drug monitoring in patients with renal insufficiency.

The influence of joints and soft tissue on the natural frequency of the human tibia using the impulse response method

The influences of the joints adjacent to the human tibia, the surrounding soft tissue and the fibula on the vibrational parameters of the tibia (that is natural frequency, mode shape and damping ratio) are in need of clarification. Using five cadaveric human legs, the resonant frequency and damping ratio were measured with an accelerometer placed on the medial tibial condyle while the medial malleolus was impacted by an impulse hammer. The legs were subsequently dissected and the measurements were made in six conditions. The mode shape was obtained by use of modal analysis. Hammer impacts were given at 15 points along the three surfaces of the tibia, while an accelerometer was attached to the surface of the medial malleolus. Resonant frequencies ranged from 275 to 405 Hz in the intact specimens and successively increased with removal of the skin, muscles and foot, and then decreased with the removal of the femur and the fibula. Damping ratios successively decreased. The transitional pattern of natural frequencies was similar to that of the resonant frequencies. The mode shape represented the first bending mode and it corresponded to the condition of the tibia in which the proximal and distal ends of the bone were free.

[Stereoselective N-demethylation of chlorpheniramine in rat liver microsomes: studies on age and sex differences]

We have established a simple method for the chiral stationary-phase liquid chromatographic resolution of racemic chlorpheniramine (Chp) and its two N-demethylated metabolites, monodesmethylchlorpheniramine (DMChp) and didesmethylchlorpheniramine (DDMChp), using an ovomucoid-conjugated column with respective quantitation limits of 5 ng/ml. The assay was used to study the age and sex difference in stereoselective N-demethylation of Chp by rat liver microsomes. The formation rate of each DMChp from racemic Chp was about 2.2 times faster with the S-(+)-enantiomer than the R-(-)-enantiomer in male rats at the age of only 8 weeks, whereas the rate of N-demethylation in male rats was not different between S-(+)- and R-(-)-enantiomers at the age of 3 and 24 weeks. The Vmax/Km value for the formation of S-(+)-DMChp increased with age in male rats, but the value in 8-week-old rats was lower than that in 3-week-old rats in the formation of R-(-)-DMChp. In female rats, on the other hand, the formation rate of DMChp from racemic Chp did not differ between S-(+)- and R-(-)-enantiomers at each age, suggesting a lack of stereoselectivity in the microsomal N-demethylation. Moreover, the Km and Vmax values for N-demethylation of Chp enantiomers were nearly identical between two consecutive ages in female rats. Further metabolism of DMChp to DDMChp was not observed between both enantiomers in male and female liver microsomes at the age of 3, 8 and 24 weeks.

The role of a complement regulatory protein in rat mesangial glomerulonephritis

The host cells are protected from the indiscriminate attack of homologous complement by the membrane-associated complement regulatory proteins. A mouse monoclonal antibody (mAb) 512 (immunoglobulin G1 subclass) has recently been described that recognizes and inhibits the function of a rat complement regulatory protein, a rat homologue of mouse Crry/p65. The aim of this work is to assess the role of a complement regulatory protein (512Ag) recognized by mAb 512 in the complement-dependent glomerular injury induced by mAb OX7 against rat Thy-1.1. For the induction of mesangial injury, the left kidney of a rat was perfused with a combination of OX7 and 512 and the perfusate was discarded from the renal vein (Group I). After the renal artery and vein were restored, the left kidney was connected to the systemic circulation. Rats were euthanized 3 h, 2 days, and 14 days later. Rats perfused either with OX7 (Group II) or with 512 (Group III) or with vehicle only (Group IV) were used as controls. At 3 h, rats of Group I showed more prominent cellular infiltration and mesangial lysis and more C3 deposition in the glomeruli than rats of Group II. Rats of Groups III and IV showed no significant changes. At Day 2, there was still significant mesangial lysis and leukocyte infiltration in Group I rats, whereas rats in other groups showed an almost normal appearance. Glomerular injury in Group I rats returned to normal by Day 14.

Developmental changes of alpha 1-adrenergic chronotropic action on human sinus node

The important role of alpha 1-adrenoceptors in reperfusion ventricular arrhythmia is mentioned in the introduction. However, the present report is concerned with the sinus node. It is speculated that the decreased positive chronotropic action of alpha 1-adrenergic stimulation due to aging may contribute to the development of sick sinus syndrome.

Infection with Helicobacter pylori strains possessing cagA is associated with an increased risk of developing adenocarcinoma of the stomach

To determine whether infection with a Helicobacter pylori strain possessing cagA is associated with an increased risk of development of adenocarcinoma of the stomach, we used a nested case-control study based on a cohort of 5443 Japanese-American men in Oahu, Hawaii, who had a physical examination and a phlebotomy during 1967 to 1970. We matched 103 H. pylori-infected men who developed gastric cancer during a 21-year surveillence period with 103 H. pylori-infected men who did not develop gastric cancer and tested stored serum specimens from patients and controls for the presence of serum IgG to the cagA product of H. pylori using an ELISA. The serum IgG assay using a recombinant CagA fragment had a sensitivity of 94.4% and a specificity of 92.5% when used in a clinically defined population; serological results were stable for more than 7 years. For men with antibodies to CagA, the odds ratio of developing gastric cancer was 1.9 (95% confidence interval, 0.9-4.0); for intestinal type cancer of the distal stomach, the odds ratio was 2.3 (95% confidence interval, 1.0-5.2). Age < 72 years and advanced tumor stage at diagnosis were significantly associated with CagA seropositivity. We conclude that infection with a cagA-positive H. pylori strain in comparison with a cagA-negative strain somewhat increases the risk for development of gastric cancer, especially intestinal type affecting the distal stomach.