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Biomedical subjects

M Kawai

Publications and source records attributed to M Kawai.

At least 163 records · Page 9Linked to original sources

Adaptation of pancreatic islet B-cells during the last third of pregnancy: regulation of B-cell function and proliferation by lactogenic hormones in rats.

In rodents, placental lactogen (PL)-I is considered to be the first trigger to enhance pancreatic islet B-cell function, and after its secretion is diminished at mid-pregnancy, PL-II takes over this role. However, little information is available on the regulation of islet B-cell function and proliferation by lactogenic hormones during the last third of pregnancy. This was the focus of the present study using rats in which pregnancy was forcibly prolonged. This rat possesses unique characteristics in that PL-I is re-secreted during the prolonged period of pregnancy and the peak concentrations in maternal circulation are comparable with those observed during mid-pregnancy in normal-pregnancy rats. Pregnancy was prolonged by successive administration of pregnant mare's serum gonadotropin (30IU/rat, s.c. on day 12) and human chorionic gonadotropin (10IU/rat, i.v. on day 14). When the insulin secretory responses to 10mmol/l glucose in islets obtained from normal-pregnancy and prolonged-pregnancy rats were tested, each insulin secretory response correlated well with the values of plasma lactogenic activity throughout the period of pregnancy and lactation. Examination of B-cell proliferation in normal-pregnancy rats showed that 5-bromo-2'-deoxyuridine (BrdU) incorporation into dividing B-cells reached a maximum on day 15 and then decreased markedly towards term. No increase in B-cell proliferation was observed on day 19 when plasma lactogenic activity reached the maximum. In prolonged-pregnancy rats, BrdU incorporation also continued to decrease as observed in normal-pregnancy rats after day 15, and then no enhancement in B-cell proliferation was observed even when the plasma lactogenic activity, including re-secreted PL-I, reached maximum. These results suggest that, in the last third of pregnancy, B-cell proliferation is no longer stimulated by lactogenic hormones in contrast to the insulin secretory response which is sustained.

Adaptation, Physiological↗

The type A behavior pattern and immune reactivity to brief stress: change of volume of secretory immunoglobulin A in saliva.

This article presents findings of a laboratory experiment on the association of the Type A behavior pattern with reactivity of secretory immune functioning to brief stress. 38 female undergraduate students classified as Type A (n = 19) or as Type B (n = 19) on the basis of their scores on the Kwansei Gakuin Type A scale performed a continuous arithmetic task in a situation in which they were exposed to aversive loud noise. Secretory immunoglobulin A (s-IgA) in saliva and autonomic measures (heart rate and frequency of eyeblink) were evaluated before and after the manipulation of stress. The volume of s-IgA at baseline was significantly higher for the Type A group than for the Type B group, suggesting that the former relative to the latter might be chronically higher in mucosal immune functioning. Also, the volume of s-IgA significantly increased after exposure to a brief stress for the Type B group but did not change for the Type A group, a finding which might indicate that the Type A group may have less immune reactivity to a brief stress.

Adult↗

[Pediatric onychomycosis treated with oral antifungal drugs].

Pediatric onychomycosis is a rare disease and it is difficult to decide in such cases whether or not an oral antifungal is indicated. We have observed 6 pediatric cases with onychomycosis who were treated with fluconazole or itraconazole: four male and two female patients, ranging in age from three to 14 years. One patient suffered infection in the fingernails and toenails. The etiologic organism was identified as Trichophyton rubrum. The treatment regimen consisted of systemically administering fluconazole to four of the patients and itraconazole to the other two. Treatment resulted in three of the 4 patients treated with fluconazole, and one of the 2 treated with itraconazole being healed completely. The other two patients treated with fluconazole and itraconazole showed an alleviation of symptoms. Further results of our study were that while younger patients respond quickly and positively to treatment, long-term follow-up is necessary even after treatment ceases due to the easy recurrence of this condition.

Administration, Oral↗

[A significance of the washout of 123I-BMIPP in patients with vasospastic angina].

We investigated the washout of 123I-BMIPP from early and delayed SPECT in 28 patients with vasospastic angina from the standpoint of the intervals from the last angina attack. We divided myocardial wall into 13 segments from the early and delayed SPECT, and visually classified into four grades of defect score ranged from 0 (normal) to 3 (severe defect). Early and delayed severity scores were calculated as a total of defect scores in 3 vessel territories, and washout scores (WS) as (delayed severity score-- early severity score)/number of segments. WS of the group within 1 month from last angina attack was compared with the groups more than 1 month. In the territory of the right coronary artery, the group within 1 month showed significantly higher WS than groups more than 1 month (p < 0.05). In the other two territories, the group within 1 month showed higher WS than one of the groups more than 1 month, but the difference was not statistically significant. We considered that the washout of 123I-BMIPP may reflect the clinical course of vasospastic angina.

Adult↗

[Prandial hypoxia in progressive muscular dystrophy].

Progressive muscular dystrophy patients often show progressive body weight loss in early adolescence. This severe body weight loss frequently causes superior mesenteric artery syndrome which may result in a fatal outcome. We performed prandial pulse oximetry and found 12 out of 35 Duchenne muscular dystrophy patients, 1 out of 2 Becker muscular dystrophy patients and 1 out of 3 Limb-Girdle muscular dystrophy patients showed prandial hypoxia with tachycardia. The patients became tired and eating habits were easily interrupted resulting in progressive body weight loss. Nasal administration of 0.2L/min oxygen to 2 Duchenne muscular dystrophy patients, and nasal intermittent positive pressure ventilation to 2 Duchenne muscular dystrophy patients, 1 Becker muscular dystrophy patient and 1 Limb-Girdle muscular dystrophy patient for 15-30 minutes before eating improved the prandial hypoxia and halted the progression of body weight loss. This prandial hypoxia is one of the earliest signs of respiratory failure in progressive muscular dystrophy.

Adolescent↗

Corticosteroid resistant interstitial pneumonitis in dermatomyositis/polymyositis: prediction and treatment with cyclosporine.

OBJECTIVE: To determine the characteristics of corticosteroid resistant interstitial pneumonitis (IP) in dermatomyositis (DM) and polymyositis (PM), and to evaluate the effect of cyclosporine on corticosteroid resistant IP in DM/PM. METHODS: We analyzed retrospectively the incidence, clinical features, and corticosteroid responses of IP in 111 patients with DM (56) or PM (55). All patients with DM/PM were treated with prednisolone, and corticosteroid resistant IP was defined as a progression of IP despite administration of 1 mg/kg/day prednisolone for more than 4 weeks. We also evaluated the effect of cyclosporine on corticosteroid resistant IP in patients with DM/PM. RESULTS: IP occurred in 24 of 56 DM and 12 of 55 PM patients. We then classified IP in DM/PM according to serum CPK levels at the onset of IP; IP associated with high CPK levels (type I) (19) and IP associated with normal CPK levels (type II) (17). Only 2 of 19 (11%) type I IP were resistant to prednisolone therapy, while 14 of 17 (82%) type II IP were resistant to prednisolone therapy. Thus, patients with type II IP showed poorer prognosis than those with type I IP (one year survival rate: type I 89% vs type II 31%). Cyclosporine was effective in all 5 cases with corticosteroid resistant IP in DM/PM (one year survival rate 80%). CONCLUSION: (1) Corticosteroid resistant IP develops mostly in patients with DM/PM without CPK elevation at the onset of IP (type II IP), and (2) cyclosporine is effective for the corticosteroid resistant IP in DM/PM and significantly prolongs survival of patients.

Adult↗

[The usefulness of tracheostomy in Duchenne muscular dystrophy ventilated by a chest respirator].

The respiratory dysfunction in Duchenne muscular dystrophy (DMD) patients increases with age. We have attempted various methods of artificial respiration for them. Recently, a non-invasive positive pressure ventilation (NIPPV) became the first choice of respiration, but the chest respirator (CR) was still one of the choices. In our hospital, DMD patients with tracheostomy wearing a CR were alive for longer period, despite of respiratory dysfunction and complications. We studied 6 DMD patients with CR to evaluate nocturnal hypoxia index (NHI) by examining nocturnal periodic hypoxia, and measured oxygen saturation after 20 mg of clomipramine hydrochloride administration before sleep. Three patients had periodic nocturnal hypoxia which was prevented by the clomipramine administration. Two patients with tracheostomy did not exhibit hypoxia. We speculated that pharyngeal hypotonia during REM sleep induces periodic nocturnal hypoxia, therefore the tracheostomy would prevent hypoxia. Next, we examined the pharyngeal MRI on one DMD patient at the same disease stage who also had night NIPPV. We found that his soft palate and tongue shifted downward, which narrowed his pharynx during REM sleep. Consequently we have concluded that noctunnal periodic hypoxia is mainly caured by obstructive sleep apnea. For DMD patients with CR, the tracheostomy may be effective to prevent hypoxia during sleep.

Adult↗

[Cardiac deformity and dysfunction in facioscapulohumeral dystrophy--electrocardiogram, ECG gate cardiac MRI studies].

We studied the cardiac deformity and dysfunction in 8 patients with facio-scapulo-humeral (FSH) muscular dystrophy by electrocardiogram (ECG) and ECG gated cardiac magnetic resonance imaging (MRI). Two of the 8 FSH patients revealed elevated P waves and 3 of these patients revealed multifocal atrial premature contractions (APC) on ECG as reported previously. On ECG-gated MRI, the flattened thorax with anteriorly shifted vertebrae restricted the right ventricular movement. On the other hand, the right atrium is often enlarged. It is known that the patients suffering from severe "funnel chest" or "straight back syndrome" often develop similar ECG abnormalities and right atrial dysfunction resulting from restricted right ventricular dilatation. Although a possibility that the abnormal P waves or multifocal APC frequently observed in FSH are caused by myocardial degeneration selectively occurring in right atrium remains to be excluded, the characteristic thoracic deformity may play a primary role in the development of cardiac problems in this hereditary muscular disorder.

Adult↗

[Treatment of cancer ascites by combined intraperitoneal administration of low-dose CDDP and reinfusion of ultra-filtrated and concentrated ascitic fluid in patients].

Ascites due to carcinomatous dissemination is a severe problem for end-stage cancer patients. We attempted treating patients on an outpatient basis with the administration of low-dose CDDP-i.p. and reinfusion of ultrafiltrated and concentrated ascites. From 1995, we performed this therapy on 16 patients with concentrated ascites 6-8 fold and reinfusion, combined with low-dose CDDP-i.p. and drip infusion of 5-FU intravenously. The ascitic fluid was significantly decreased after treatment in 8 patients, and 2 patients had lasting low concentrations of CA 125. CA 125 decreased in 83.3% of patients, who tended to have extended survival times after remarkable ascites pooling and treatment with low-dose CDDP-i.p. and reinfusion therapy. This treatment is a useful cant method for decreasing ascites and improving QOL.

Adult↗

Modulation of hepatic CYP2A1, CYP2C11, and CYP3A9 expression in adult rats by neonatal administration of tamoxifen.

To examine the effect of neonatal administration of tamoxifen on adult expression of hepatic cytochrome P-450 (CYP) enzymes and steroid 5alpha-reductase, male and female Sprague-Dawley rats were injected s.c. with tamoxifen (20 microg) or peanut oil (control) once daily at days 1 to 5 of age and sacrificed at 3 months of age. Neonatal tamoxifen treatment did not affect b.wt. or liver weight of adult male and female rats, but decreased testicular weight by approximately 40% in adult male rats. Neonatal administration of tamoxifen decreased hepatic microsomal testosterone 6beta- and 7alpha-hydroxylase activities in adult female rats whereas it did not alter steroid 5alpha-reductase activity. The same treatment increased testosterone 7alpha-hydroxylase activity, but did not affect testosterone 6beta-hydroxylase or steroid 5alpha-reductase activity in adult male rats. Immunoblot analysis indicated that neonatal tamoxifen treatment decreased CYP2C11 protein level by 26% and increased CYP2A1 protein content by 2.6-fold in adult male rats, whereas it had no effect on CYP3A or CYP2B protein expression. The reduction in the CYP3A-mediated testosterone 6beta-hydroxylase activity in adult female rats was accompanied by a decrease in CYP3A9 mRNA expression. Analysis of serum hormone levels indicated that neonatal exposure to tamoxifen resulted in a decrease in serum 17beta-estradiol concentration in adult female rats, whereas it did not alter serum testosterone concentration in adult male rats. In summary, treatment of neonatal rats with tamoxifen produced a long-lasting effect on hepatic CYP2A1, CYP2C11, and CYP3A9 expression in addition to testicular weight and serum 17beta-estradiol concentration.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗

[A case with posterior column ataxia associated with cerebellar ataxia and sensory neuropathy].

The patient was a 72-year-old man who had a history of subtotal gastrectomy for gastric ulcer at age of 37 years. He had no familial history of hereditary disorders. In 1980 he noticed mild ataxic gait which exaggerated while he closed eyes. The symptoms increased gradually, and four years later he noticed hypoesthesia of his soles. In 1983 he was admitted to the National Center Hospital for Mental, Nervous and Muscular Disorders for the first time. Neurological examination revealed dysarthria, ataxic gait, disturbance of coordination to a slight degree, and muscle strength of the upper and lower limbs were in normal range. Mild hypoesthesia of pain and temperature sensation, and marked decrease of deep sensation and vibration of the lower extremities were demonstrated. Romberg sign was positive. EMG studies revealed low amplitude of action potential and normal motor nerve conduction velocity. Biopsy of the sural nerve showed marked decrease of both large and small myelinated fibers. In 1998 he was admitted second time for the further examination. Laboratory examination including routine blood examination, blood chemistry including CRP, TPHA, vitamin B1, B2, B12, A, E, K, hexosaminidase A in leucocyte were in normal range. CSF was normal. Genetic studies including SCA 1, 2, 3, 6, DRPLA, CMT1A, CMTX 1 were all negative. MCV of lower limbs was in normal range, though SCV was not evoked in the upper and lower limbs. MRI studies showed mild atrophy of the bilateral lobulus of the cerebellum which was not so much changed in the last 5 years. The clinical symptoms revealed dominant posterior column disturbance, ataxia and sensory neuropathy. These combination was not described in the previous literature, and this case may be a new variant of the spinocerebellar degeneration.

Aged↗

[Abnormal respiratory regulation in myotonic dystrophy].

The abnormal respiratory regulation as well as respiratory muscle degeneration are thought to be involved in the pathogenesis of alveolar hypoventilation in myotonic dystrophy (MD). In the present study we recorded changes in oxygen saturation resulting from exercise and hyperventilation in MD, Duchenne muscular dystrophy (DMD) patients and healthy volunteers by pulse oxymetry. Following are the results obtained in this study. (1) In DMD individuals showing preexisting mild desaturation around 90-95%, mild muscle exercise such as drawing a picture always caused further desaturation, which is presumably due to an increase in oxygen demand. On the other hand the MD patients with the same level of desaturation often showed paradoxical improvement in oxygen saturation up to 95-97% after a similar mild exercise, however, they showed obvious desaturation by a harder exercise such as propelling wheelchair. (2) There was a fluctuation of oxygen saturation at rest in MD, while this was not apparent in DMD patients and normal volunteers. (3) In MD and normal individuals, a strenuous hyperventilation is always followed by an oxygen desaturation through ventilatory suppression probably caused by hypocapnea resulting from the hyperventilation. This desaturation phase is much more prolonged in MD patients than in normal control subjects. The above data indicate further evidence of abnormal ventilatory regulation in MD.

Adult↗

[Diagnosis of inflammatory myopathy; usefulness of 99mTc MDP scintigraphy and muscle MRI for determination of affected sites].

We studied the effectiveness of 99mTc-MDP (methylendiphosphate) scintigraphy in imaging inflammatory myopathy. The three subjects including 1 male and 2 female patients had high creatine kinase (CK) levels and proximal dominant muscle weakness. In whole body muscle surveillance by 99mTc-MDP scintigraphy, abnormal 99mTc-MDP accumulation was found in the extremities of all patients. The sites with high 99mTc-MDP accumulation showed high intensity on T2 weighted MR imaging, suggesting an inflammatory process. Muscle biopsy was performed on two patients from the muscles with the abnormal MRI findings, which showed the diagnostic finding of inflammatory changes. Because muscle involvement in inflammatory myopathy differs from muscle to muscle, it is sometimes difficult to choose appropriate muscle biopsy sites for diagnostic purposes. Affected muscles are more easily identified by using 99mTc-MDP muscle scintigraphy and muscle MRI, therefore, a correct diagnosis and choice of biopsy site can be made. 99mTc-PYP scintigraphy is permitted for use in myocardial infarction alone and 111In-antimyosin scintigraphy is not available in Japan. Therefore, we recommend 99mTc-MDP scintigraphy for diagnosis of inflammatory myopathy and for determination of muscle biopsy sites.

Adolescent↗

Modified sagittal split ramus osteotomy with a reciprocating saw and new retractors.

Modified sagittal split ramus osteotomy with new instruments and a reciprocating saw is reported. With this modification, the sagittal separation of the ramus is performed by the reciprocating saw with an original wide-blade buccal retractor and a new lingual retractor, instead of the traditional channeled retractor. The wide-blade retractor is inserted to the buccal aspect of the mandibular ramus, which ensures protection from instrumental injury to the adjacent soft tissues and vessels, and the new lingual retractor, instead of the channeled retractor, is inserted to the lingual aspect of the ramus. The osteotomy line follows that of Dal Pont's modification. Close attention must be paid to the direction of the saw blade. The separated bone plane should be located in the external cortical bone layer of the ramus, so as to avoid injury of the inferior alveolar neurovascular bundle. The osteotomy is completed with the smooth osteotomized interface, which facilitates positioning of the bone segments by the surgeon. The new instruments and the reciprocating saw may provide safe and rapid sagittal split ramus osteotomy.

Episode of Care↗

Mouse placental cells secrete soluble leptin receptor (sOB-R): cAMP inhibits sOB-R production.

The aims of this study were to identify whether mouse placenta secretes soluble OB-R (sOB-R) and to find the regulating factor of OB-R expression. Total RNAs were extracted from placenta and decidua, and OB-R expression was assessed by Northern blot analysis. Decidua did not express OB-R mRNA. However, OB-R mRNA expression was detectable in the placenta on day 13 of pregnancy, and then it increased and reached a peak on day 17 of pregnancy. Mouse placental cells from day 12 of pregnancy were cultured and OB-R gene expression was assessed by Northern blot analysis. OB-R mRNA expression was detectable from the second day of culture and reached a peak on the third day of culture. To determine whether placental cells release sOB-R, supernatant of cultured placental cells was subjected to Western blot analysis. sOB-R was detected in the medium by the second day of culture and sOB-R release increased up to the fourth day of culture. Addition of leptin to the medium did not affect expression of OB-R mRNA. However, 8-bromo cAMP inhibited both steady-state levels of OB-R mRNA and the amount of sOB-R protein in the medium in a dose- and time-dependent manner. These results suggest that trophoblast cells differentiate, express, and release sOB-R both in vivo and in vitro and that cAMP is one of several potent regulators of sOB-R secretion by the mouse placenta.

8-Bromo Cyclic Adenosine Monophosphate↗