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Biomedical subjects

S Hashimoto

Publications and source records attributed to S Hashimoto.

At least 379 records · Page 21Linked to original sources
PubMed1998

The usefulness of computed tomography in the diagnosis of impacted fish bones in the oesophagus.

The usefulness of computed tomography (CT) in the diagnosis of fish bone impaction in the oesophagus was evaluated. Thirty-two patients were examined by plain X-ray followed by direct oesophagoscopy for suspected fish bone impaction. Among 25 cases in which fish bones were actually removed, foreign bodies were not clearly demonstrated by plain X-ray in 14 cases (56 per cent). Eleven cases underwent CT prior to the oesophagoscopic examination. Fish bones were clearly demonstrated by CT in all patients. CT also clearly visualized secondarily-induced inflammatory changes in the neighbouring structures. In order to confirm this result, we made a simulation model of oesophageal fish bone impaction, using fish bones of three different species surrounded by a water bag. In comparison with plain X-ray, CT depicted a superior image of fine fish bones and provides extremely useful information for the management of impacted fish bones in the oesophagus.

Aged↗
PubMed1998

Correlation of plasma monocyte chemoattractant protein-1 (MCP-1) and monocyte inflammatory protein-1alpha (MIP-1alpha) levels with disease activity and clinical course of sarcoidosis.

MCP-1 and MIP-1alpha exhibit chemotactic activity toward macrophages/monocytes and induce the production of inflammatory cytokines affecting granuloma formation. Up-regulated expression of MCP-1 and MIP-1alpha in the affected organ of sarcoidosis has been shown; however, the relationship between their plasma levels and the clinical course of this disease has not been determined. In the present study we measured plasma MCP-1 and MIP-1alpha levels in 26 patients with active sarcoidosis by ELISA in order to assess the state of MCP-1 and MIP-1alpha in this disease. Most patients in this study (21/26) had clinical evidence of extrathoracic disease in addition to pulmonary involvement. In addition, a high proportion of patients (n = 15) showed spontaneous remission of disease, whereas five patients showed no spontaneous remission and six patients were treated with corticosteroids over the 2-year period of study. At the time of diagnosis, both plasma MCP-1 and MIP-1alpha levels in patients with active sarcoidosis were significantly higher than in the normal controls. The levels of these cytokines in patients with extrathoracic disease were compatible with those in patients without extrathoracic disease. A longitudinal evaluation of plasma MCP-1 and MIP-1alpha levels showed that the changes in both cytokines were closely related to the clinical course of sarcoidosis. These results suggest that plasma MCP-1 and MIP-1alpha may be useful parameters for monitoring the clinical course of sarcoidosis. In addition, plasma MCP-1 and MIP-1alpha may reflect subclinical evidence of extrathoracic sarcoidosis and may play a role in initiating monocyte migration into the tissue.

Adult↗
PubMed1998

Free-running of plasma melatonin rhythm prior to full manifestation of a non-24 hour sleep-wake syndrome.

A long-term observation of a sighted man who developed a non-24 h sleep-wake syndrome is reported. A partial entrainment was observed first, whereby the sleep-wake rhythm was entrained by the day-night alternation whereas the circadian rhythm in plasma melatonin was free-running. Two years later, the sleep-wake rhythm of this subject started to free-run together with the melatonin rhythm. Oral administration of melatonin for 2 weeks improved the entrainability of both rhythms but failed to entrain the rhythms completely. It is concluded that the free-running of the circadian pacemaker preceded a full manifestation of a non-24 h sleep-wake syndrome in this particular subject.

Administration, Oral↗
PubMed1998

A study of the proliferative activity of the long junctional epithelium using argyrophilic nucleolar organizer region (AgNORs) staining.

The proliferative activity of the long junctional epithelium (LJE) in rats was examined using stains for argyrophilic proteins of the nucleolar organizer region (AgNORs protein). The LJE was experimentally produced by insertion of a rubber piece between maxillary molars for 1 wk. After removal of the rubber, the length and AgNORs parameters of the LJE were measured and analyzed statistically. The LJE widely covered the apical side of the exposed root surface 4 wk after the removal. Its length was longest after 4 and 8 wk; it became shorter subsequently. The AgNORs were visible as black dots of various sizes and numbers on the sections. A high potential for proliferation was obvious in the LJE after 4 wk and was maintained until 12 wk after the removal. The AgNORs ratio on the connective tissue interface of the LJE was about twice of that of normal junctional epithelium after 4-12 wk. The proliferative activity on the root surface side was slightly increased after 4 wk. There was no significant difference in proliferative activity between the coronal and apical sides. These results suggest that the proliferative activity of the LJE is maintained continuously at a high level on the connective tissue interface supplying the epithelial cells. Basal cells proliferate at the connective tissue interface of the LJE, migrate directly to the root surface or via the apical portion and finally desquamate from the surface of the epithelium.

Animals↗
PubMed1998

Twenty-four hour rhythm of melatonin in patients with a history of pineal and/or hypothalamo-neurohypophyseal germinoma.

Melatonin deficiency after a pinealectomy has been investigated in animals; however, in humans, this status can be assessed solely by investigating patients with a tumor originating in the pineal gland. This study analyzes secretion of melatonin and pituitary hormones in 14 patients with germinoma originating in the pineal or the hypothalamic-neurohypophyseal region. Thirteen patients had been successfully treated prior to this study. One patient was included in this study before the initiation of treatments. Plasma sampling was performed every 2 hr for 24 hr and melatonin concentrations were measured by radioimmunoassay. Melatonin secretion was nearly absent in the patients with pineal germinoma regardless of treatment option, even in the patient who had been untreated. In contrast, melatonin secretion and its circadian rhythms were not affected in patients with a hypothalamo-neurohypophyseal germinoma. The circadian rhythms of growth hormone and adrenocorticotropic hormone were not dysregulated in patients with the melatonin deficiency. We conclude that germinoma cells originating the pineal gland impair the production of melatonin by pineocytes and consequently induce a permanent melatonin deficiency in those patients. Since melatonin exerts multiple physiological functions, once a clinical concept of "melatonin deficiency syndrome" is established, melatonin replacement therapy could be investigated in patients who have a pineal germinoma or who have undergone a neurosurgical pinealectomy.

Adolescent↗
PubMed1998

[Shigella dysenteriae strains possessing a new serovar (204/96) isolated from imported diarrheal cases in Japan].

Five Shigella strains isolated from stool cultures of imported diarrheal cases in Japan, did not react to any antisera of the established Shigella serovars. These strains had the typical biochemical characteristics of Shigella dysenteriae, and were biochemically identical. All strains were positive in the Sereny test and other tests for invasivness; these indicate that they can cause shigellosis in humans. The results of antigenic analysis revealed that they did not belong to any of the recognized or provisional serovars, and were serologically indistinguishable. They had the same drug-resistance pattern (CP.TC.SM.ABPC.ST) and plasmid-profile. Strain 96-204 is designated as the test strain for this new serovar.

Anti-Bacterial Agents↗
PubMed1998

Role of alveolar macrophages in initiation and regulation of inflammation in Pseudomonas aeruginosa pneumonia.

To evaluate the role of alveolar macrophages (AMs) in acute Pseudomonas aeruginosa pneumonia in mice, AMs were depleted by aerosol inhalation of liposomes containing clodronate disodium. AM-depleted mice were then intratracheally infected with 5 x 10(5) CFU of P. aeruginosa. In addition to monitoring neutrophil recruitment and chemokine releases, lung injury was evaluated soon after infection (8 h) and at a later time (48 h). At 8 h, depletion of AMs reduced neutrophil recruitment, chemokine release, and lung injury. At 48 h, however, depletion of AMs decreased bacterial clearance and resulted in delayed movement of neutrophils from the site of inflammation with aggravated lung injury. With instillation of 5 x 10(7) CFU of bacteria, AM-depleted mice showed low mortality within 24 h of infection but high mortality at a later time, in contrast to non-AM-depleted mice. These results demonstrate that depletion of AMs has beneficial early effects but deleterious late effects on lung injury and survival in cases of P. aeruginosa pneumonia.

Acute Disease↗
PubMed1998

Effects of chronic nitric oxide synthase inhibition on renal function and histology in polycythemic rats.

Augmented endogenous nitric oxide (NO) production may ameliorate derangement of renal functions or glomerular damage in polycythemia. To investigate this possibility, we examined the effect of NO synthase inhibition with N omega-nitro-L-arginine methyl ester (L-NAME; 50 mg/dl in drinking water) on renal functions and histology in heminephrectomized Sprague-Dawley rats treated for 4 weeks with recombinant human erythropoietin (rh-EP; 500 IU/kg on alternate days). L-NAME elevated the blood pressure which was aggravated by concomitant rh-EP and was ameliorated by treatment with a nonpeptide angiotensin type 1 receptor blocker (CV116; 60 mg/kg in chow). The hematocrit level was prominently increased by rh-EP. The glomerular filtration rate was impaired by L-NAME alone, but was maintained by concomitant administration of rh-EP or CV116. Micropuncture experiments revealed that the glomerular capillary pressure was similarly elevated by L-NAME alone or in combination with rh-EP. L-NAME significantly, although not prominently, aggravated glomerular sclerosis observed with rh-EP alone, and concomitant CV116 ameliorated the glomerular damage. These results suggest that, in polycythemia, enhanced NO production buffers the glomerular damage, and the balance between NO and angiotensin II may play an important role in maintaining renal function and glomerular structure.

Angiotensin Receptor Antagonists↗
PubMed1998

Solitary bronchioloalveolar adenoma of the lung.

A case of an unusual pulmonary neoplasia, called bronchioloalveolar adenoma of the lung, is reported. The neoplasm presented as a solitary peripheral lesion of the left lung on computed tomography. Examination of the tumor revealed a focal proliferating lesion consisting of cuboidal or peg-shaped epithelial cells with slight nuclear atypia. Immunohistochemical study with anti-carcinoembryonic antigen antibody, anti-surfactant apoprotein antibody, and anti-Clara cell antibody suggested that this neoplasia has the characteristics of a type II pneumocyte. It is likely that more of these small peripheral lesions, which have potential for evolution to carcinoma, will now be encountered due to the introduction of helical CT of the chest.

Adenoma↗
PubMed1998

Expression of inducible nitric oxide synthase and inflammatory cytokines in alveolar macrophages of ARDS following sepsis.

STUDY OBJECTIVE: The objective of this study was to evaluate the role of inducible nitric oxide synthase (iNOS) and proinflammatory cytokines in alveolar macrophages (AMs) in the pathogenesis of ARDS following sepsis. SETTING: ICU in a university hospital. DESIGN: Prospective exploratory, open-labeled study was carried out. PATIENTS: A total of 24 patients were investigated: 8 patients diagnosed as having ARDS following sepsis (ARDS group); 8 patients under general anesthesia in the operating room whose lung functions were normal (control group); and 8 patients who were intubated and artificially ventilated for 1 week in the ICU whose lung functions were not deteriorated without fulfilling the ARDS criteria and whose general state fulfilled the sepsis criteria (long-term ventilation group, or LTV group). MEASUREMENTS AND RESULTS: The expression of iNOS, interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and interleukin-8 (IL-8) in AMs obtained from BAL fluid (BALF) was determined by the immunofluorescent technique. We observed the significant expression of iNOS, IL-6, and IL-8 only in the ARDS group. Meanwhile, NOx (the sum of NO2- + NO3-) was elevated in the BALF supernatant, and IL-6 and IL-8 levels in both the BALF supernatant and the serum were also elevated in the ARDS group. No significant expressions were detected in the control and the LTV group. CONCLUSIONS: The result that iNOS was detected only in ARDS patients following sepsis suggests that iNOS together with proinflammatory cytokines produced by AMs might play a pivotal role in the pathogenesis of acute lung injury and be useful for monitoring disorders in the lung in such conditions.

Adult↗
PubMed1998

The acoustic reflex for filtered broadband stimuli: a lesser contribution of the lower frequency neurons.

The effects of the cut-off frequency of the filtered broadband stimuli on the human acoustic reflex (AR) were examined to observe the relation between the area of excitation in the cochlea and the AR response. The results obtained have indicated that all the input from the cochlear region does not equally contribute to trigger the AR equally; i.e., there is a lesser contribution from the frequency region below 700 Hz.

Adult↗
PubMed1998

The effect of oral feeding of Lactobacillus casei strain Shirota on immunoglobulin E production in mice.

We investigated the effect of oral feeding of heat-killed Lactobacillus casei strain Shirota on immunoglobulin E (IgE) production in mice. The strain was orally administered to BALB/c mice that had been preinjected intraperitoneally with ovalbumin, and the level of IgE in serum was determined. Results indicated that the oral feeding of L. casei strain Shirota was effective in inhibiting IgE production in serum, and the IgE production in response to ovalbumin was significantly inhibited in the mice. The in vitro production of IgE by the spleen cells from mice fed L. casei strain Shirota in response to restimulation with ovalbumin was inhibited in contrast to that of spleen cells from the control group. We also examined the pattern of cytokine production by spleen cells from mice fed L. casei strain Shirota followed by restimulation with ovalbumin in vitro. In the mice fed L. casei strain Shirota, the production by the spleen cells of Th1 cell-associated cytokines, such as interferon-gamma and interleukin-2, was higher than that by the spleen cells from the control group. In contrast, the production of Th2 cell-associated cytokines, such as interleukin-4, interleukin-5, interleukin-6, and interleukin-10, by spleen cells in the group fed L. casei strain Shirota was lower than that by the cells from the control group. Furthermore, the interleukin-12 production of the spleen cells from mice fed L. casei strain Shirota was also higher than that of the control group.

Animals↗
PubMed1998

Heterogeneous induction of apoptosis in colon cancer cells by wild-type p53 gene transfection.

To examine the effects of wild-type (wt)-p53 gene transfer on cancer cell growth and apoptosis induction, we transduced human wt-p53 cDNA into three colon cancer cell lines either with or without a mutation of the p53 gene using the HVJ-cationic liposome method. Wt-p53 gene transfer, thus, induced an apparent growth arrest in all cell lines, but its enhancement of the apoptotic rate varied (from about 4 to 70 times). The simultaneous doxorubicin treatment was able to enhance growth arrest and the apoptosis induction rate. These findings suggest that wt-p53 gene transfer using HVJ-cationic liposomes seems to be a potentially effective therapeutic strategy, however wt-p53 gene transfer still appears to be more effective in combination with other cytotoxic treatments.

Apoptosis↗