Twenty-four hour monitoring of pH in the gastric tube replacing the resected esophagus

BACKGROUND

Peptic ulcers in the gastric tube replacing the resected esophagus develop silently and cause serious problems. In this study, the acidity of the gastric tube was examined by 24-hour pH monitoring to determine if the acidity of the gastric tube was sufficient to cause peptic ulcers.

STUDY DESIGN

The acidity of a gastric tube was evaluated by 24-hour pH monitoring of both the fundus and the antrum in 55 patients treated for carcinoma of the esophagus. The correlation between the fasting serum gastrin concentration and the intraluminal acidity of the completely vagotomized gastric tube was examined.

RESULTS

In the patients with high postoperative acidity in the fundus or the antrum (46 percent of the 41 patients examined), the intraluminal pH remained consistently low, even long after operative treatment. Significant correlations existed between the percentage of time that the pH remained below 3 preoperatively and postoperatively in both the fundus and the antrum (r = 0.4777, p = 0.0386, and r = 0.7597, p = 0.0002, respectively). The percentage did not decrease significantly postoperatively. A significantly negative correlation (r = -0.783401, p < 0.0001) was found between the fasting serum gastrin level and the proportion of time that the nocturnal pH in the antrum remained below 3.

CONCLUSIONS

Even long after esophagectomy, the pH of the gastric tube is low enough to cause peptic ulcers, especially in patients with high preoperative acidity. In these patients, the intraluminal pH in the antrum of the gastric tube correlates inversely with the fasting serum gastrin level.

An angiotensin II receptor antagonist attenuates left ventricular dilatation after myocardial infarction in the hypertensive rat

OBJECTIVE

The aims were (1) to investigate the effect of hypertention on left ventricular dilatation and haemodynamic alterations following acute myocardial infarction in spontaneously hypertensive rats (SHR) and normotensive rats (WKY); (2) to compare haemodynamic indices between the two groups; (3) to assess whether the angiotensin II type 1 receptor antagonist (AIIA), TCV-116, prevented left ventricular dilatation after myocardial infarction; and (4) to compare the effect of AIIA with that of the angiotensin converting enzyme (ACE) inhibitor, delapril.

METHODS

Myocardial infarction was produced in SHR and WKY by coronary artery ligation. Haemodynamic measurements were obtained three weeks later in rats that had been treated from the next day after the operation for three weeks with TCV-116 (1 mg.kg-1.d-1) or delapril (1 g.litre-1 in drinking water), and in untreated controls.

RESULTS

After myocardial infarction, left ventricular weight, and left ventricular weight were greater in SHR than in normotensive rats. Right ventricular weight, left ventricular end diastolic pressure, and LVEDVI correlated positively with infarct size in both SHR and WKY and these slopes were steeper in SHR than in WKY (P < 0.05). TCV-116 and delapril each significantly attenuated the increases in left ventricular end diastolic pressure, left ventricular weight, right ventricular weight, and LVEDVI following myocardial infarction in both in WKY and SHR, and shifted pressure-volume curve significantly to the left.

CONCLUSIONS

Hypertension accelerates left ventricular dilatation and haemodynamic alterations following myocardial infarction in rats. These effects are attenuated by an angiotensin II type 1 receptor antagonist as well as by an ACE inhibitor.

Shortening of the hippocampal formation in first-episode schizophrenic patients

Shortening of hippocampal formation (HF) in chronic schizophrenic patients have been demonstrated in our previous study. The purpose of the present study is to test if shortening of the HF occurs in schizophrenic patients suffering their initial psychotic episode. We performed contiguous, 1 mm thick, magnetic resonance imaging scans in 20 first-episode schizophrenic patients, 21 chronic schizophrenic patients, and 25 healthy subjects. Both groups of schizophrenic patients demonstrated significant shortening of the HF compared with normal controls (first-episode schizophrenia, 5.3%; chronic schizophrenia, 8.0%). However, the HF length was not significantly different between the first-episode and chronic schizophrenic patients. No significant correlation was seen between the HF length and the duration of illness in chronic schizophrenic patients. These results suggest that the HF shortening observed in schizophrenic patients may be genetic and/or developmental in origin.

[Improved protection of hypertrophied myocardium in ischemia by histidine buffer cardioplegia]

Pressure overload hypertrophy has been known risk factor for open heart surgery, because of accelerated loss of high energy nucleotides, greater accumulation of H+ and lactate, and earlier onset of contracture. To test the efficacy of histidine containing cardioplegia (HB) on promotion of anaerobic glycolysis leads to improved preservation of hypertrophied heart, hypertrophied rabbit heart (aortic banding at 10 days) received HB or high potassium Krebs buffer solution (KCl) were subjected to 40 min of 37 degrees C ischemia followed by reperfusion in an isolated Langendorff mode. There was significantly higher phosphocreatine, intracellular pH and lactate production which was an indicator of anaerobic glycolysis and better recovery of cardiac function in HB group compared to KCl group. We concluded that histidine containing cardioplegia was able to promote anaerobic glycolysis to maintain high energy phosphates as well as contractile function in hypertrophied myocardium.

Parainfluenza virus type 1 infects olfactory neurons and establishes long-term persistence in the nerve tissue

A mouse model of Sendai virus infection was adopted to examine the in vivo neurovirulence of parainfluenza viruses. A nested polymerase chain reaction detected the Sendai virus nucleoprotein gene in the olfactory bulbs of intranasally infected mice for at least 168 days post-infection (p.i.) and virus-specific messenger RNAs for 28 days p.i. Viral proteins were histochemically detected in some olfactory neurons for 7 days p.i. They were also found in glomeruli of the olfactory bulbs but not in the mitral cells and the tufted cells. No virus was detected in the whole brain not including the olfactory bulbs. When mice were inoculated with UV-inactivated virus, the viral RNA was present in the olfactory bulbs for a short period of 14 days, with no demonstrable viraemia. These results demonstrate that the parainfluenza virus directly accesses the central nervous system via olfactory neurons and establishes long-term persistence in the nerve tissue.

Nucleotide sequence of the gene encoding novel delta-endotoxin from Bacillus thuringiensis serovar japonensis strain Buibui specific to scarabaeid beetles

A new isolate of Bacillus thuringiensis serovar japonensis strain Buibui, which was specific to scarab beetles (M. Ohba et al., Lett. Appl. Microbiol. 14:54, 1992), was shown to have a 130-kDa insecticidal crystal protein (ICP) (H. Hori et al., J. Appl. Bacteriol. 76:307, 1994). ClaI restriction enzyme fragments of total cell DNA of the isolate were cloned into E. coli (Sato et al., Curr. Microbiol. 28:15, 1994). Whole 3480-bp nucleotide sequence of the gene encoding 130-kDa ICP was determined, and the molecular weight of the ICP was estimated to be 130,424. The strongly conserved five blocks that occur in almost all ICP genes of B. thuringiensis were detected in the ORF with the same order and almost the same intervals as elsewhere. The amino acid sequence homologies of the whole ICP or N-terminus half portion to that of the CryIIIA, B, C, D, and CryV were about 35%.

[A case of incarceration of a right femoral hernia in a very old female with a intriguing clinical course]

The patient was a 94-year-old woman. She was admitted on our hospital for ileus due to incarceration of a right femoral hernia on October 29, 1993. Although an emergency operation was necessary she refused, therefore we continued to have conservative therapy. After repeated persuasion, she agreed the operation which was performed under spinal anesthesia on November 17. The peritoneal cavity was opened through a transverse incision of the lower abdomen. Some bloody ascites was encountered. Part of the jejunum was incarcerated through right femoral canal and was completely obstructed, with ischemic but no necrotic changes. It was excised. She resumed oral intake on the 7th postoperative day and was discharged on the 77th postoperative day. Initially due to her opposition we could not perform the operation, but after persistent persuasion she agreed and survived. Good communications between the doctor and the patient, and of course informed consent, was very important in such cases.

In vivo angioscopic detection of the damaged endothelium on the atheromatous plaque: application with vital staining by methylene blue

We attempted to detect the lesion of the damaged endothelium on the atherosclerotic plaque in vivo with dye and angioscope. The plaques were induced on the aortae of rabbits by the continuous mechanical injury with the insertion of the polyethylene tube and feeding with 2% cholesterol-added diet. We observed the some plaques could be stained with 5 x 10(-2) mol/L methylene blue by angioscope. Control aorta, without any stimulations on the aorta, could not be stained. One month after injury and cholesterol feeding the plaques were stained. In such plaques, the lack of the endothelium and the existence of the lipid-containing cell in the intima was observed. However, the plaques of the aorta 6 months after finishing these procedures could not be stained. In these plaques, the morphological characteristics known as the regression of the atheromatous plaque, ie, the regeneration of the endothelium, the thick collagen layer on the plaque and the massive calcification of the plaque were observed. The results obtained were as follows. (1) The atheromatous lesion with the damaged endothelium could be detected in vivo by our vital staining method. (2) The atheromatous plaques stained in vivo are the lesion with complication and enhanced permeability. (3) The slightly stained plaques indicate the lesions with regression and lost high permeability. (4) Our method would be able to add important information on the atheroscrelotic lesions in the clinical situations than that now we perform.

Desensitization of capsaicin-sensitive sensory neurons in rat stomachs on chronic treatment with sodium taurocholate

We examined the effects of chronic treatment with 10 mM sodium taurocholate (TC) on gastric functions, capsaicin-sensitive afferent neurons and the gastric mucosa in male rats. Stomachs were mounted in Lucite chambers, and then the transmucosal potential difference (PD), luminal pH and gastric mucosal blood flow (GMBF) in response to TC or capsaicin was determined. In normal animals, 10 mM TC caused a reduction in PD, and increases in luminal pH and GMBF. Capsaicin (1 mg/ml) produced an apparent increase in GMBF without any change in PD or luminal pH. After 4- or 12-week treatment with TC, the basal PD was significantly reduced, and the luminal pH tended to increase. The increase in GMBF in response to TC or capsaicin was profoundly suppressed in TC-pretreated animals. The calcitonin gene-related peptide release in response to capsaicin was significantly reduced after 4 weeks treatment with TC. There were no microscopical changes in the oxyntic mucosa until 4 weeks after TC treatment except for exfoliation of surface cells. However, an increase in inflammatory cell infiltration was observed 12 weeks later. We conclude that chronic treatment with TC causes desensitization of capsaicin-sensitive afferent neurons and reduces GMBF, which may result in the production of gastritis.

[Reticulated platelets--automated measurement and clinical utility]

Development of the method to determine reticulated platelets is briefly reviewed. A new rapid method to automatically count reticulated platelets is very recently established by our research group. The principle of the measurement of reticulated platelets is based on flow cytometry. The platelets are quickly stained with a RNA fluorescent dye, auramine O and fluorescent intensity (RNA content) and forward scatter (cell size) are measured in only 80 seconds with a reticulocyte counter, equipped with special software for analysis of reticulated platelets. Both of the reproducibility and the linearity were shown to be good. Normal percentage value for reticulated platelets was 0.98% +/- 0.41% and its absolute count was 2.12 +/- 0.69 x 10(9)/l. The absolute count was decreased in patients with reduced thrombopoiesis such as acute myeloblastic leukemia, aplastic anemia and was elevated in patients with essential thrombocythemia and in chronic myelocytic leukemia. The patients with chronic idiopathic thrombocytopenic purpura had a high percentage of reticulated platelets. An apparent rise was noticed in the percentage of reticulated platelets which preceded by several days a progressive increase in the platelet count at the recovery phase of thrombocytopenia in a couple of leukemic patients. These suggest that an automated measurement of reticulated platelets can be clinically useful to estimate thrombopoiesis in bone marrow.

Mechanism of gastric alkaline response in the stomach after damage. Roles of nitric oxide and prostaglandins

The gastric mucosa responds to hypertonic NaCl by significantly decreasing acid secretion. We examined the role of nitric oxide (NO) in this phenomenon in comparison with endogenous prostaglandins (PGs). A rat stomach was mounted in an ex vivo chamber, perfused with saline, and the potential difference (PD), pH, and acid/alkaline responses were measured before and after the application of hypertonic NaCl (1 mol/liter) with or without pretreatment with NG-nitro-L-arginine methyl ester (L-NAME; an inhibitor of NO biosynthesis) or indomethacin (a cyclooxygenase inhibitor). NaCl at 1 M caused a PD reduction, a decrease in acid secretion, and an increase in luminal HCO3-. Prior administration of L-NAME (5 mg/kg, intravenously) as well as indomethacin (5 mg/kg, subcutaneously) did not affect PD and HCO3- responses, but significantly attenuated the inhibitory effect of 1 M NaCl on acid secretion, although the effect of L-NAME was more potent when compared to indomethacin. This effect of L-NAME was antagonized by the simultaneous administration of L-arginine but not by D-arginine (200 mg/kg, intravenously), whereas the effect of indomethacin was completely reversed by PGE2 (100 micrograms/kg, intravenously). The histamine-stimulated acid secretion in the normal stomach was significantly decreased by nitroprusside (the exogenous NO donor; 4 mg/kg, intravenously) and PGE2, but not by either L-NAME or indomethacin. These results suggest that in addition to PGs, NO is involved in the mechanism of the gastric alkaline response after damage with 1 M NaCl. Irritation of the gastric mucosa by hypertonic NaCl may release endogenous NO and PGs, both of which in turn inhibit acid secretion and unmask luminal alkalinization due to HCO3- flux in the damaged portion.

Determination of the spleen-blood partition coefficient for water with oxygen-15-water and oxygen-15-carbon dioxide dynamic PET steady-state methods

METHODS

Regional splenic blood flow (SBF) was quantified by PET using a steady-state method with 15O-carbon dioxide. SBFs were determined using 104 tomographic planes obtained from 49 patients.

RESULTS

When the spleen-blood partition coefficient for water (p) was > or = 0.85, significant correlations (p < 0.005) were found between SBF values determined by the steady-state and dynamic methods. The best correlation between SBFs determined by the two methods (r = 0.571) was found when p = 0.93. The best regression line, however, was thought to be the line when p = 0.93. The regression line between SBF calculated by the steady-state method (y) and SBF determined by the dynamic method (x) was y = 0.57 x + 0.03 with an F ratio of 48.75 (d.f. = 103, p = 5.0 x 10(-8)%, by ANOVA) when p = 0.92.

CONCLUSION

A quick evaluation of SBF can be made by using the newly defined regression line.

CSF shunt physics: factors influencing inshunt CSF flow

Cerebrospinal fluid (CSF) in a shunt does not have a constant flow rate. The flow fluctuates from 0.01 ml/min to 1.93 ml/min according to each patient's own daily supine rhythmic pattern. We determined and evaluated the factors influencing CSF flow in a shunt in 19 cases of hydrocephalus. Postural changes, such as head elevation, led to increases by over 0.04 ml/min in inshunt CSF flow, while inshunt CSF flow in the supine position was less than 0.04 ml/min. Respiratory changes, such as coughing and apnea-hyperventilation, also influenced inshunt CSF flow. Changes in intracranial pressure (ICP) corresponded to changes in inshunt CSF flow. Inshunt CSF flows were higher than average during the night, the flows being stimulated by increases in ICP especially during REM sleep.

Effects of nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester on duodenal alkaline secretory and ulcerogenic responses induced by mepirizole in rats

The inhibition of nitric oxide (NO) production by NO synthase inhibitors stimulates HCO3- secretion in the rat duodenal mucosa. Therefore, we examined the effects of NG-nitro-L-arginine methyl ester (L-NAME, the NO synthase inhibitor) and nitroprusside (the exogenous NO donor) on the duodenal HCO3- and ulcerogenic responses in anesthetized rats. Animals were administered mepirizole (200 mg/kg, subcutaneously) for induction of duodenal ulcers, and gastric acid and duodenal HCO3- secretions were measured with or without pretreatment with L-NAME (5 mg/kg, intravenously) or nitroprusside (4 mg/kg, intravenously). Mepirizole increased acid secretion, decreased the acid-induced duodenal HCO3- secretion, and induced hemorrhagic lesions in the proximal duodenum. The inhibition of NO production by L-NAME potentiated the acid secretory response, increased the duodenal HCO3- secretion, and prevented the duodenal lesions, and these changes were all antagonized by simultaneous administration of L-arginine (200 mg/kg, intravenously) but not D-arginine. On the other hand, nitroprusside slightly reduced the acid response but further decreased the HCO3- output, resulting in aggravation of duodenal lesions induced by mepirizole. These data suggest that the inhibition of endogenous NO production by the NO synthase inhibitor L-NAME increases duodenal HCO3- secretion and protects the duodenal mucosa against acid injury.

Association of p120, a tyrosine kinase substrate, with E-cadherin/catenin complexes

p120 was originally identified as a substrate of pp60src and several receptor tyrosine kinases, but its function is not known. Recent studies revealed that this protein shows homology to a group of proteins, beta-catenin/Armadillo and plakoglobin (gamma-catenin), which are associated with the cell adhesion molecules cadherins. In this study, we examined whether p120 is associated with E-cadherin using the human carcinoma cell line HT29, as well as other cell lines, which express both of these proteins. When proteins that copurified with E-cadherin were analyzed, not only alpha-catenin, beta-catenin, and plakoglobin but also p120 were detected. Conversely, immunoprecipitates of p120 contained E-cadherin and all the catenins, although a large subpopulation of p120 was not associated with E-cadherin. Analysis of these immunoprecipitates suggests that 20% or less of the extractable E-cadherin is associated with p120. When p120 immunoprecipitation was performed with cell lysates depleted of E-cadherin, beta-catenin was no longer coprecipitated, and the amount of plakoglobin copurified was greatly reduced. This finding suggests that there are various forms of p120 complexes, including p120/E-cadherin/beta-catenin and p120/E-cadherin/plakoglobin complexes; this association profile contrasts with the mutually exclusive association of beta-catenin and plakoglobin with cadherins. When the COOH-terminal catenin binding site was truncated from E-cadherin, not only beta-catenin but also p120 did not coprecipitate with this mutated E-cadherin. Immunocytological studies showed that p120 colocalized with E-cadherin at cell-cell contact sites, even after non-ionic detergent extraction. Treatment of cells with hepatocyte growth factor/scatter factor altered the level of tyrosine phosphorylation of p120 as well as of beta-catenin and plakoglobin. These results suggest that p120 associates with E-cadherin at its COOH-terminal region, but the mechanism for this association differs from that for the association of beta-catenin and plakoglobin with E-cadherin, and thus, that p120, whose function could be modulated by growth factors, may play a unique role in regulation of the cadherin-catenin adhesion system.

Interleukin-8 gene expression in chronic sinusitis

PURPOSE

Interleukin-8 (IL-8), a monocyte-derived and macrophage-derived cytokine, displays potent chemotactic activating properties toward neutrophils and thus may contribute to the pathogenesis of chronic sinusitis. The object of this investigation was to show the expression of the IL-8 gene in chronic sinusitis by Northern blot analysis and a reverse transcription-polymerase chain reaction (RT-PCR).

MATERIALS AND METHODS

For Northern blot analysis, RNAs were extracted from maxillary mucosa and nasal polyps from two patients with chronic sinusitis, respectively, and from the inferior turbinate of a nasal allergy patient. For RT-PCR, RNAs were extracted from 11 patients with chronic sinusitis, 8 patients with allergic rhinitis, and 4 patients with hypertrophic rhinitis.

RESULTS

Whereas IL-8 mRNA was expressed in the maxillary mucosa, IL-8 transcript was not detected in the inferior turbinate by Northern blot analysis. IL-8 transcripts were detected in 45% of chronic sinusitis RNAs (5/11) and in 50% of allergic rhinitis RNAs (5/10) by RT-PCR.

CONCLUSION

These data suggest IL-8 may contribute to neutrophil involvement in chronic sinusitis.

Expression of endogenous retroviruses, ERV3 and lambda 4-1, in synovial tissues from patients with rheumatoid arthritis

We addressed the question of whether or not expression of human endogenous retroviruses (ERV), ERV3 and lambda 4-1, is related to the pathogenesis of rheumatoid arthritis (RA). In genomic Southern hybridization, there were no significant differences between RA patients and healthy volunteers with regard to frequencies of restriction fragment length polymorphism (RFLP) patterns, for either ERV3 or lambda 4-1. By Northern blot analysis using fresh synovial tissues, cultured synovial cells, and peripheral blood mononuclear cells (PBMC) from patients with RA, we noted two molecular species of ERV3 mRNAs of 3.5 kb and 9.0 kb sizes, and one single molecular species of lambda 4-1 mRNAs of 4.2 kb size. The expression was detected not only in RA patients but also in synovial cells from osteoarthritis (OA) as a non-RA control and PBMC from healthy volunteers, and was not related to RA activities or treatments. Although ERV3 and lambda 4-1 expression may not be directly associated with the pathogenic pathway of RA, the possibility exists that human ERV may have a causative role in autoimmune diseases, including RA. We also examined the effect of cytokines on the transcriptional regulation of ERV3. Although the level of ERV3 expression in cultured synovial cells did not change with IL-1 beta treatment, the level for cultured proximal tubular epithelial cells (hKEC) was up-regulated.

Expression of CD44 variant exons 8-10 in colorectal cancer and its relationship to metastasis

Splice variants of CD44 are overexpressed in human lung, breast, and colon carcinoma cell lines. This study was conducted to clarify the association between the expression of CD44 variant exons 8-10 and metastatic potential in human colorectal cancer. We found that the expression of a CD44 splice variant containing exons v8-10 was increased in all of 60 colorectal cancer specimens examined compared with matched normal colerectal mucosa, as determined by Northern blotting. Expression of CD44 variant exons 8-10 did not significantly correlate with histological type, depth of tumor invasion, lymphatic invasion, venous invasion, or lymph node metastasis. However, the level of CD44 variant exon 8-10 expression was significantly higher in carcinomas associated with liver metastasis than in those without liver metastasis. In addition, expression of CD44 variant exons 8-10 in the liver metastases was more intense than that in the primary colorectal cancers. These findings indicated that this domain of the CD44 glycoprotein encoded by exons v8-10 may play an important role in tumor hematogenous metastasis of human colorectal cancer.

Automated measurement of reticulated platelets in estimating thrombopoiesis

We described a fully automated measurement of reticulated platelets using a fluorescent dye, auramine O, and a reticulocyte counter, the R-3000, equipped with special software. Reproducibility and linearity were shown to be good. In the normal subjects studied (n = 60), the mean value for reticulated platelets was 0.98% +/- 0.41% and the mean absolute count was 2.12 +/- 0.69 x 10(9)/l. The absolute count for reticulated platelets was significantly lower (p < 0.05) in patients with reduced thrombopoiesis as seen in acute myeloblastic leukemia, aplastic anemia or chemotherapy-induced thrombocytopenia and it was elevated (p < 0.05) in essential thrombocythemia and in chronic myelocytic leukemia with thrombocytosis. All 20 patients with chronic idiopathic thrombocytopenic purpura had a high percentage of reticulated platelets. The percentage of reticulated platelets was significantly increased (p < 0.05) in patients with impaired thrombopoiesis despite the reduction in the absolute count. In 2 leukemic patients, an apparent rise was noticed in the percentage of reticulated platelets which preceded by several days a progressive increase in the platelet count at the recovery phase of thrombocytopenia. The results suggest that an automated measurement of reticulated platelets can be applied to routine laboratories for clinical use.

Role of the sympathetic nervous system in gastric functional changes induced by thyrotropin-releasing hormone in rats

We determined the changes in gastric functions and systemic blood pressure in response to thyrotropin-releasing hormone (TRH) simultaneously in anesthetized rats and examined the role of the sympathetic nervous system in these changes. TRH injected i.c. increased gastric acid secretion, contraction and mucosal blood flow, and produced hemorrhagic lesions in the glandular stomach. These responses to TRH were almost completely inhibited by bilateral cervical vagotomy or atropine. The increased gastric acid secretion and contraction in response to TRH were significantly augmented by pretreatment with yohimbine but not with prazosin. Bilateral adrenalectomy also potentiated the gastric acid secretory and contractile responses to TRH. Neither prazosin, yohimbine nor adrenalectomy had any appreciable effect on the increased gastric mucosal blood flow induced by TRH. TRH-induced gastric mucosal lesions were significantly aggravated by yohimbine and adrenalectomy. In vagotomized rats, TRH significantly suppressed the gastric functional changes induced by electrical stimulation of the vagus nerves. These data suggest that while gastric functional changes and mucosal lesions induced by TRH mainly occur through stimulation of the vagus nerves, these responses are extensively modified by the sympathetic nervous system including the adrenal glands.

[The development of a tissue calcium-detecting apparatus]

Calcium phosphate is deposited in tissues with progression of aging and arteriosclerosis, causing impairments of organ functions. Localization and quantification of tissue calcium phosphate are important for elucidation of the cause of this calcium phosphate deposition. Tissue calcium phosphate has been detected by Von Kossa-Nishiyama staining using the heavy metal substitution technique. By this method, however, the reaction was weak because of the use of sunbeam as the light source, and consistent detection was difficult. Especially, fine calcium phosphate granules that appear in early stages of the pathological changes could not be detected. Therefore, we evaluated a method for preparation of tissue specimens, light source, filter, and staining conditions, and developed a more reliable method for detection and assay of tissue calcium phosphate. The human aortic tissue was fixed with formalin, embedded with paraffin, and cut to a thickness of 4 microns using a glass knife. Solax-XCA100B, an artificial sunbeam lamp with a spectrum nearly identical with that of the sun, was used as the light source. A B filter, which selectively filters out the wavelengths 290nm or less and 800-1,000nm, was used. The appearance of abnormal granules due to excessive reaction could be prevented by eliminating ultraviolet rays with wavelengths of 290nm or less, and burning of the tissue and the appearance of silver particles could be prevented by excluding infrared rays with wavelengths of 800nm or above. Distilled water was continuously dripped into the reaction solution to prevent an increase in the concentration due to evaporation. The reaction showed appreciable progression until after 40 minutes and stopped completely after 80 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

cDNA cloning of mouse VLA-3 alpha subunit

cDNA clones for mouse VLA (very late antigen)-3 alpha subunit (alpha 3 integrin) were isolated and sequenced. The encoded mouse alpha 3 integrin subunit was composed of 1,053 amino acid residues. The results of sequence analysis revealed similar structural characteristics of other VLA alpha subunits. For example, the presence of a large extracellular domain including three putative metal binding sequences, a transmembrane domain, and a short cytoplasmic domain. A higher level of its message was detected in thymus than in kidney, stomach, spleen, liver, brain, or lung by Northern blotting analysis.

Irritant and protective action of urea-urease ammonia in rat gastric mucosa. Different effects of ammonia and ammonium ion

The effects of urea-urease-ammonia on the rat gastric mucosa were examined and compared with those of NH4OH and NH4Cl. The mucosal application of urea with urease produced a reduction in potential difference (PD) in a dose-related manner for urea, and a significant drop was observed by > 0.1% urea in the presence of 100 units urease. Such PD reduction was also observed when the mucosa was exposed to either NH4OH (> 0.03%) or NH4Cl (> 1%); delta PD (20 mV) caused by 0.3% NH4OH and 3% NH4Cl was equivalent to that induced by 0.5% urea+urease (100 units). The combined oral administration of urea (approximately 6%) and urease (100 units) did not induce any macroscopic damage in the gastric mucosa. NH4Cl given orally had no or little effect on the mucosa at any dose levels even at 10%, while NH4OH given orally caused hemorrhagic lesions in the mucosa at the dose of > 0.3%. In contrast, both urea+urease and NH4Cl given prior to HCl/ethanol protected the gastric mucosa against damage in a dose-related manner, and a significant effect was obtained by urea at > 0.5% and by NH4Cl at > 1%. NH4OH was also effective in reducing the severity of HCl/ethanol-induced gastric lesions at lower dose (0.3%). The protective effect of urea+urease was attenuated significantly by prior administration of indomethacin or coadministration of hydroxyurea, while that of NH4Cl or NH4OH was mitigated by indomethacin.(ABSTRACT TRUNCATED AT 250 WORDS)