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Biomedical subjects

K Fukushima

Publications and source records attributed to K Fukushima.

At least 19 recordsLinked to original sources

De novo glucan synthesis by mutants streptococcal glucosyltransferases present in pellicle promotes firm binding of Streptococcus gordonii to tooth surfaces.

Adherence of 3H-labelled cells of Streptococcus gordonii and Streptococcus milleri to artificial pellicles prepared from saliva supplemented with glucosyltransferases from mutants streptococci was examined using a new assay for sucrose-dependent cell-to-pellicle attachment. Results indicate that S. gordonii, but not S. milleri, could attach tightly to hydroxylapatite surfaces through de novo glucan synthesis by mutants streptococcal glucosyltransferases present in the experimental salivary pellicles.

Bacterial Adhesion

Light and electron microscopic immunolocalization of endothelial leucocyte adhesion molecule-1 in inflammatory bowel disease. Morphological evidence of active synthesis and secretion into vascular lumen.

Endothelial leucocyte adhesion molecule-1 (ELAM-1) is a rapidly inducible adhesion molecule for neutrophils in vascular endothelial cells. We investigated its immunohistochemical localization in 17 cases of inflammatory bowel disease. ELAM-1 was preferentially expressed in venules in actively inflamed mucosa and granulation tissue. Most capillaries were negative for ELAM-1. In areas with mild inflammation its expression diminished markedly and in normal mucosa of the colon and small intestine its expression was sparse. Electron microscopically, venules in active inflammation had swollen endothelial cells with well-developed rough endoplasmic reticulum. Immunoelectron microscopy revealed ELAM-1 localization along the luminal plasma membrane and in rough endoplasmic reticulum and round granules, findings suggestive of active production in endothelial cells. Furthermore, exocytosis of immunoreactive substance into the lumen was confirmed. Our study suggests that venules in actively inflamed area play an important role in eliciting and/or maintaining acute inflammatory processes by active permeation of neutrophils from the blood stream into the tissue, and that ELAM-1 may be a secretory protein as well as a transmembrane receptor protein.

Adult

Ocular torsion produced by unilateral chemical inactivation of the interstitial nucleus of Cajal in chronically labyrinthectomized cats.

Unilateral lesions of the rostral midbrain involving the interstitial nucleus of Cajal (INC) have been known to produce ocular torsion in alert animals including humans, which has been assumed to be the result of an impaired otolith-ocular reflex. We examined the effects of chemical deactivation of the INC using a gamma-aminobutyric acid (GABA) agonist (muscimol) in cats that had received bilateral labyrinthectomy, and compared the results with those in normal cats. Ocular torsion with a magnitude similar to that observed in normal cats appeared in chronically labyrinthectomized cats after unilateral muscimol infusion into the INC, indicating that ocular torsion following unilateral INC deactivation can be produced by a mechanism independent of the otolith-ocular reflex.

Animals

The interstitial nucleus of Cajal is involved in generating downward fast eye movement in alert cats.

We examined whether or not the interstitial nucleus of Cajal (INC) is involved in generating vertical fast eye movement. We used a gamma-aminobutyric acid (GABA) agonist (muscimol) to deactivate the INC cell bodies bilaterally in alert head-fixed cats. The INC was identified by recording vertical eye position-related burst-tonic neurons. Following muscimol infusion into the bilateral INC, the cats were unable to hold eccentric upward eye position after saccades, and the mean time constant of postsaccadic drift was 0.4 sec. In addition, downward saccades were virtually lost without clear impairment of horizontal saccades. Muscimol infusion into the Forel's field H resulted in loss of both upward and downward fast eye movement as reported previously. Bilateral electrolytic INC lesions produced results similar to those after muscimol infusion into the INC, suggesting that the cutting of passing fibers in the INC alone cannot explain the selective loss of downward fast eye movement. These results indicate that the INC itself is involved in generating downward fast eye movement. We propose that the loss of activity in possible downward burster-driving neurons in the INC can explain the selective loss of downward fast eye movement after bilateral INC lesions.

Animals

Ultrasonographic screening for renal abnormalities in three-year-old children.

We report the results of ultrasonographic screening to determine the prevalence of renal abnormalities in children. This study was conducted simultaneously with a regular health check using portable realtime ultrasound equipment, from July 1988 to June 1989. Of 2920 three-year-old children resident in Kurume City, 2351 (80.5%) were screened. Abnormalities were detected in 11 (0.47%) of these, involving six cases of pelvic dilatation, three cases of unilateral renal agenesis, and two cases of a unilaterally small kidney. However, the simultaneous urinalysis of these 11 children did not disclose these abnormalities. Our results indicate that ultrasonography is an efficient tool for screening for a silent renal abnormality.

Blood Urea Nitrogen

Expression of Streptococcus mutans gtf genes in Streptococcus milleri.

The Streptococcus mutans glucosyltransferase (GTF) genes gtfB and gtfC were ligated into Escherichia coli-streptococcus shuttle plasmids and introduced into Streptococcus milleri. gtfB transformant KSB8 formed an S. mutans-like rough colony on mitis salivarius agar and expressed an extracellular GTF-I, of 158 kDa, and two cell-bound GTF-Is, of 158 and 135 kDa. gtfC transformant KSC43 formed a semirough colony on mitis salivarius agar and expressed primarily an extracellular GTF-SI, of 146 kDa, and two cell-bound GTF-SIs, of 146 and 152 kDa. The extracellular GTFs from KSB8 and KSC43 were purified and characterized. The two types of GTF also reacted specifically with monoclonal antibodies directed against each enzyme. Both enzymes synthesized significant amounts of oligosaccharides, consisting primarily of alpha-1,6-glucosidic linkages, as well as water-insoluble glucans, containing alpha-1,3-glucosidic linkages. Insoluble-glucan-synthesizing activities of both enzymes were stimulated (three- to sixfold) by the addition of dextran T10 and were inhibited in the presence of 1.5 M ammonium sulfate. The Km(s) for sucrose and the optimal pHs were also similar for both enzymes. However, when the transformants were grown in Todd-Hewitt broth supplemented with sucrose, KSC43 cells, expressing GTF-SI activity, adhered to glass surfaces in vitro, while KSB8 cells, expressing GTF-I activity, did not. These results are discussed relative to the potential role of the gtfB and gftC genes in S. mutans cariogenicity.

Ammonium Sulfate

Serum and urinary inorganic fluoride concentrations after prolonged inhalation of sevoflurane in humans.

Serum and urinary concentrations of inorganic fluoride were measured before and after sevoflurane anesthesia in 10 patients without renal disease, who were scheduled for surgery lasting 13.4 +/- 0.9 h (mean +/- SE). The mean concentration of serum inorganic fluoride reached a maximal value of 42.5 +/- 4.5 mumol/L at the end of anesthesia. However, 5 of 10 patients had serum inorganic fluoride concentrations that exceeded 50 mumol/L (i.e., the nephrotoxic dose). A positive correlation was found between serum inorganic fluoride concentration and anesthetic dose. The largest urinary excretion of inorganic fluoride was 1804 +/- 378 mumol/day in the first postoperative day and rapidly decreased thereafter. We concluded that lengthy sevoflurane anesthesia created serum inorganic fluoride concentrations that could influence renal function, although nephrotoxicity was not demonstrated in our biochemical study.

Aged

Postremission therapy without prednisolone improves survival in adults with acute leukemia.

This prospective randomized clinical trial was to clarify whether postremission therapy without prednisolone (PSL) was more effective than therapy with PSL in improving the 5-year survival of adults with acute leukemia. Thirty consecutive adult patients with newly achieved complete remission were randomized to receive postremission therapy either with or without PSL between September 1985 and September 1988. The patients ranged from 16 to 57 years in age. Patients treated without PSL had a significantly better 5-year survival rate than those receiving PSL according to Kaplan-Meier analysis (53.5% vs 15.3%, p < 0.05). In the group treated without PSL, eight out of 15 patients were alive at 72 months, and seven patients maintained their first complete remission at 72 months. Among patients with acute lymphoblastic leukemia (ALL) who were treated without PSL the median duration of remission was 24 months, and the survival rate at 72 months was 50.0%. On the other hand, the median survival was only 13 months for the 5 patients with ALL treated with PSL. Thus, it is desirable that adults with acute leukemia are treated by postremission therapy without PSL.

Acute Disease

Long-term results of pylorus-preserving gastrectomy for gastric ulcer.

The postoperative results of pylorus-preserving gastrectomy (PPG) for gastric ulcer performed in 134 patients during the past 25 years (mean postoperative period, 16.6 years) were studied. The incidence of postoperative complications was low. Dumping syndrome occurred in only 4.4% and 0% of cases as assessed by questionnaire and interview, respectively. Four (5.4%) of 74 patients available for this study had ulcer recurrence. In one of these four patients concurrent gastroduodenal ulcer was suspected from preoperative gastric analysis. The site of recurrence was found in all cases to be the remnant antral gland area along the greater curvature between the proper gastric gland area and the duodenum. Basal and maximal acid outputs at the time of relapse were significantly higher in patients with recurrence than in patients without recurrence. The fasting and postprandial serum gastrin levels were high in one patient with recurrence, whose antrum was preserved as long as 3 cm proximal to the pyloric ring; this was longer than that described in our original method of PPG. In two other recurrent cases the serum gastrin levels were not different from those in nonrecurrent cases. Immunohistochemical examination of the residual antrum showed no increase in the G-cell density in patients either with or without recurrence. These results suggest that the long-term quality of life of patients treated with PPG remains favorable. Recurrence rate can be further reduced if PPG is strictly indicated for gastric ulcer only and carried out by meticulous surgical techniques. In the pathogenesis of the ulcer recurrence the role of gastrin release from the residual antral mucosa seems to be limited.

Adult

Immunolocalization of mineralocorticoid receptor in human kidney, pancreas, salivary, mammary and sweat glands: a light and electron microscopic immunohistochemical study.

Using a polyclonal antibody against a synthetic fusion protein corresponding to 167 amino acids of the N-terminal region of the human renal mineralocorticoid receptor (MR), an immunohistochemical study was performed to investigate the intraglandular and intracellular localization of the receptor in human kidney, salivary gland, pancreas, mammary gland and sweat gland both at the light and electron microscopic levels. In the kidney, immunoreactivity was observed in distal convoluted tubules, branches of Henle's loop, and collecting tubules in the renal cortex, and papillary and Henle's loops' ducts in the renal medulla. No significant differences in the distribution of immunoreactivity were observed using different fixatives (10% neutral formalin, 100% methanol, 4% paraformaldehyde, PLP (periodate-lysine-2% paraformaldehyde) solution and Zamboni solution) and processing methods (paraffin embedding and frozen sectioning). Immunoreactivity in the kidney was observed in both the cytoplasm and nucleus, with cytoplasmic staining predominant, regardless of the methods of tissue preparation. Immunoelectron microscopy, employing a pre-embedding method, demonstrated the presence of immunoreaction precipitates in nuclei, endoplasmic reticulum, perinuclear cisternae, free cytoplasm and cell membranes. In nuclei, immunoreactivity was observed in euchromatin but not in heterochromatin, which is consistent with an association of MR with specific DNA regulatory elements located in transcriptionally active euchromatin. In other organs, MR was expressed in cells of the excretory ductal system where mineralocorticoids are known to play a role in electrolyte homeostasis.

Animals

[Tumor associated carbohydrate antigens in bronchoalveolar lavage fluid in patients with diffuse panbronchiolitis].

It is known that tumor associated carbohydrate antigens are significantly increased in the serum of patients with diffuse panbronchiolitis (DPB). We investigated carbohydrate antigens (SLX, CA19-9) in bronchoalveolar lavage fluid (BALF) obtained from 24 patients with DPB. The concentrations of SLX and CA19-9 were significantly higher in BALF from patients with DPB than those from healthy subjects (7 cases) and patients with pulmonary sarcoidosis (16 cases). No significant correlation was observed between either SLX or CA19-9 concentrations in the serum and BALF, and no significant correlation was observed between the concentrations of these carbohydrate antigens in BALF and clinical findings. Immunohistochemical study of SLX and CA19-9 in open lung biopsy specimens obtained from patients with DPB showed expression of SLX and CA19-9 on the bronchiolar surface epithelial cells and mucinous exudates in air spances. These results indicate that carbohydrate antigens are presumably increased in the pulmonary lesions of patients with DPB, and this increase causes high levels of these antigens in the serum. Furthermore, we investigated the change of concentrations of SLX and CA19-9 in BALF obtained from patients with DPB after erythromycin (EM) treatment. The concentrations of these two antigens were decreased after EM treatment.

Adolescent

[Elevated production of GM-CSF by peripheral blood mononuclear cells stimulated with mite antigens in children with bronchial asthma].

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine which can stimulate the proliferation and functions of eosinophils and neutrophils. We have studied whether peripheral blood mononuclear cells (PBMC), obtained from children with stable asthma, can produce GM-CSF through stimulation with crude Dermatophagoides farinae (Df) antigen in vitro. The patients had strongly positive RAST results for house dust mite Df. Levels of GM-CSF in PBMC culture supernatant were assayed by an enzyme immunoassay. When stimulated with Df antigen, patient's PBMC released significantly increased levels of GM-CSF compared with unstimulated ones. PBMC of non-allergic controls, however, did not. The addition of polymyxin B, an inactivator of endotoxin, did not suppress the Df-antigen-induced production of GM-CSF. Levels of GM-CSF produced by PBMC stimulated with Df antigens were significantly higher in the patients than in the controls. These results indicate that PBMC of children with Df-allergic asthma, unlike those of non-allergic children, can produce elevated levels of GM-CSF by stimulation with Df antigens.

Animals

Responses to intravenous sedation by elderly patients at the Hokkaido University Dental Hospital.

Geriatric patients who undergo intravenous sedation require careful intraoperative management, because respiratory and circulatory depression usually accompanies the administration of recommended adult sedative doses. This study examined results when a single benzodiazepine, diazepam or flunitrazepam, was carefully titrated to a clinical endpoint of conscious sedation. A total of 335 cases was divided into seven age groups. Mean sedative doses gradually decreased with age. The 60- to 69-yr group required about 75% of the adult recommended dose, the 70- to 79-yr group required 40% to 60%, and the 80- to 89-yr group required 30% to 45%. Pulse oximetry values also declined with age; respiratory depression was observed mainly in elderly patients. Declines in blood pressure after benzodiazepine administration were not correlated with age. The rise in blood pressure normally observed intraoperatively was suppressed both in young as well as old patients. We conclude that intravenous conscious sedation in elderly patients reduces stress-induced cardiovascular stimulation and that respiratory depression may occur at even low sedative doses.

Adult

[A clinical study of the long-term therapeutic effects of low-dose erythromycin in diffuse panbronchiolitis--with special reference to changes in tumor-associated carbohydrate antigens in serum].

We investigated the long-term (3-30 months) therapeutic effects of low-dose (300-600 mg/day) erythromycin in 26 patients with diffuse panbronchiolitis (DPB). Significant improvements of pulmonary functions especially in %VC and PaO2 as well as respiratory symptoms were shown. However, erythromycin treatment was not associated with a significant change in surface phenotypes on peripheral blood lymphocytes (CD4, CD8, CD4/CD8). It is well known that serum levels of tumor-associated carbohydrate antigens such as SLX (sialylated Lewis X-i) and CA19-9 (sialylated Lewis(a)) are significantly elevated in patients with DPB. In the present study, 68.4% (13/19) of DPB patients showed marked elevation of SLX and 52.9% (9/17) showed marked elevation of CA19-9 levels in serum. These positive ratios were significantly decreased by erythromycin treatment to 31.6% (6/19) in SLX and 23.4% (4/17) in CA19-9. The mean values of each marker were also significantly decreased after erythromycin administration from 54.9 +/- 26.9 U/ml to 39.5 +/- 22.1 U/ml for SLX and from 70.5 +/- 77.4 U/ml to 28.8 +/- 37.4 U/ml for CA19-9.

Adolescent

[Neuromuscular blocking effect of ORG9426, a new non-depolarizing muscle relaxant, and its recovery with various antagonists in vitro].

We evaluated the neuromuscular blocking effect of ORG9426, a new non-depolarizing muscle relaxant, and its recovery by means of washout or by antagonists in vitro, using phrenic nerve-hemidiaphragm preparations of rats. IC50 and IC90 of ORG9426 in single twitch were 10.62 +/- 0.58 microM and 15.75 +/- 0.95 microM; and those in train of four ratio were 9.04 +/- 0.38 microM and 11.87 +/- 0.42 microM, respectively. The potency of ORG9426 in vitro was compared with those of other non-depolarizing muscle relaxants. The order of potency among the non-depolarizing muscle relaxants was the following: d-tubocurarine greater than pipecuronium greater than pancuronium greater than vecuronium greater than ORG9426. There was no difference between ORG9426 and vecuronium in the recovery from block with washout, neostigmine, 4-aminopyridine, 3, 4-diaminopyridine, and edrophonium. In conclusion, the potency of ORG9426 is relatively low, and it can be easily antagonized by anti-cholinesterases and aminopyridines.

Aminopyridines