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Biomedical subjects

M Sakamoto

Publications and source records attributed to M Sakamoto.

At least 289 records · Page 16Linked to original sources
PubMed1997

Osteonecrosis of the femoral head: a prospective study with MRI.

We performed a prospective study using MRI to evaluate early necrosis of the femoral head in 48 patients receiving high-dose corticosteroids for the treatment of various autoimmune-related disorders. The mean interval from the initiation of corticosteroid therapy to the first MRI examination was 2 months (0.5 to 6). MRI was repeated, and the mean period of follow-up was 31 months (24 to 69). Abnormalities were found on MRI in 31 hips (32%). The initial changes showed well-demarcated, band-like zones which were seen at a mean of 3.6 months after initiation of treatment with steroids. In 14 of these hips (45%) there was a spontaneous reduction in the size of the lesions about one year after treatment had started, but there was no further change in size with a longer follow-up.

Adolescent↗
PubMed1997

Embryologic features of term fetuses and newborns in CL/Fr mice with special reference to cyanosis.

OBJECTIVE: The objective of this study was to clarify the embryologic features of CL/Fr mice in relation to cyanosis. METHOD: Orofacial examinations were conducted on 18-day-old term fetuses and newborns. Except for open eyelids in a few cases, all of the external abnormalities in this strain were cleft lip and/or palate (CLP). RESULTS: The CLP incidence in term fetuses was 28.4%. The body and placental weights were not different between CLP(+) and CLP(-) fetuses. Several types of CLP were found; the most frequent was bilateral complete CLP (60%) followed by left complete (16%). Bilateral complete CL, which is the most severe CL type, was associated with poorly developed secondary palate and wide cleft. In newborns, 39.4 % of CLP(+) mice showed cyanosis, where no CLP(-) mice had such signs. The body weight of cyanotic mice with CLP was significantly lighter than that of noncyanotic mice with CLP. Cyanotic mice had severe types of CLP and unelevated palatal shelves. CONCLUSION: We suggest that mechanical airway obstruction may be one of the causes of cyanosis in newborn CL/Fr mice.

Airway Obstruction↗
PubMed1997

Acute subdural hematoma without subarachnoid hemorrhage due to ruptured intracranial aneurysm--case report.

A 54-year-old female presented with acute subdural hematoma secondary to rupture of an intracranial aneurysm. She was admitted with acute onset of severe headache, nausea, and vomiting. There was no past history of head trauma. Computed tomography demonstrated a left subdural hematoma with extension along the tentorium in the absence of subarachnoid or intraparenchymal hemorrhage. Angiography revealed an aneurysm of the internal carotid-posterior communicating artery which was oriented posterolaterally. Uneventful clipping was performed and the patient was discharged from hospital without neurological deficits. The possibility of aneurysmal subdural hematoma should be considered in the absence of trauma.

Acute Disease↗
PubMed1997

[An anesthesia machine malfunction due to dew condensation produced by abnormally high humidity in the electronically-controlled panel].

We present a case of anesthesia machine (NAR-KOMED 2CTM; N2C) malfunction caused by dew condensation. N2C is electronically controlled by an alarm-panel using the remote display. Abnormally high humidity in the operating room made dew condensation in the alarm-panel resulting in an electronic short circuit. Of great importance may be the damp proof improvement on medical equipment including anesthesia machines which have electronic circuits.

Anesthesiology↗
PubMed1997

Cardiovascular regulation by L-arginine in the brain of rats: role of the brain renin-angiotensin system and nitric oxide.

The effect of brain L-arginine on arterial pressure was investigated by injecting L- or D-arginine into the cerebral ventricles of male Wistar rats that were anesthetized with urethane. Intracerebroventricular (I.C.V.) injection of 1 micromol L-arginine reduced the arterial pressure and the abdominal sympathetic nervous activity (SNA), whereas the injection of 10 micromol L-arginine induced a transient pressor response and reduced both the heart rate and SNA. Although I.C.V. injection of 1 micromol D-arginine had no effect on cardiovascular function or SNA, injection of 10 micromol of this enantiomer elicited a transient pressor response, similar to that induced by 10 micromol L-arginine, followed by a persistent increase in arterial pressure and a corresponding increase in SNA. I.C.V. pretreatment with the nitric oxide synthase inhibitor N(G)-monomethyl L-arginine abolished the vasodepressor response and reduced the inhibition of SNA induced by I.C.V. injection of 1 micromol L-arginine; such pretreatment increased the arterial pressure, heart rate, and SNA measured 30 min after I.C.V. injection of 10 micromol L-arginine. I.C.V. pretreatment with the angiotensin II type 1 receptor antagonist CV-11974 inhibited the pressor response to 10 micromol L-arginine and the first phase of the pressor response to 10 micromol D-arginine. Intravenous pretreatment with the alpha1-adrenoceptor blocker bunazosin hydrochloride abolished the pressor response to 10 micromol L-arginine and both phases of the pressor response to 10 micromol D-arginine. Brain L-arginine thus appears to exert pressor actions through stimulation of the brain renin-angiotensin system and peripheral SNA. However, these actions may be attenuated by L-arginine-derived nitric oxide.

Animals↗
PubMed1997

[General anesthesia for an infant with Rubinstein-Taybi syndrome].

A 5-year-old girl with Rubinstein-Taybi syndrome (RTS) was scheduled for ophthalmic surgery under general anesthesia. RTS is a well-defined syndrome with facial abnormalities including a high palate and micrognathia, broad thumbs and big toes, and mental retardation as main clinical features, which may be complicated with repeated respiratory infections, cardiac anomalies, and so on. Anesthesia was uneventfully induced and maintained with the inhalation of oxygen, nitrous oxide and sevoflurane. Special attention was paid to the possibilities of the difficult airway, aspiration pneumonia and cardiovascular dysfunction during anesthesia. No complications were observed throughout the perioperative procedures.

Anesthesia, General↗
PubMed1997

[A case of traumatic cardiac contusion accompanied by the rupture of pericardium].

We experienced a case of traumatic cardiac contusion accompanied by the rupture of the pericardium after multiple blunt trauma sustained in a traffic accident. A 26-year-old woman who had suffered from blunt chest and abdominal trauma was admitted to our hospital, being unconscious with multiple severe injuries including pelvic fracture, bilateral hemothorax, and multiple fractures in the extremities. The patient was in a shock status. We performed the transcatheter arterial embolization of the internal iliac arteries to control the bleeding, when aortography showed that the contrast media extravasated toward the left thoracic cavity. Immediately, an operation for blunt chest trauma was performed. Blood was flooding out of the ruptured pericardium because of the contusion of myocardium. The postoperative course was uneventful. Blunt chest trauma is usually accompanied by multisystem injury. Therefore, it is imperative to determine the priority of treatment based on preoperative examination in patients having multiple injuries.

Abdominal Injuries↗
PubMed1997

Response to interferon of GB virus C and hepatitis C virus in patients with chronic hepatitis.

OBJECTIVES: To evaluate the response to interferon and capacity to induce liver disease of a putative non-A to E hepatitis virus designated GB virus C (GBV-C). METHODS: RNA of GBV-C was detected by reverse transcription polymerase chain reaction with nested primers deduced from the 5'-noncoding region. It was titrated, along with RNA of hepatitis C virus (HCV), in 16 co-infected patients (11%) out of 140 patients who received interferon. RESULTS: At the completion of a 6-month course of interferon (total dose: 516-774 million units), GBV-C RNA disappeared from serum in seven (44%) and HCV RNA from serum in 11 (69%) patients. At 6 months after interferon treatment ended, GBV-C RNA remained cleared in three patients (19%), and HCV RNA was persistently undetectable in four (25%). One patient lost both GBV-C and HCV RNAs. The three patients whose serum was cleared of GBV-C RNA had pretreatment titers of the virus (two with 10[1]/ml and one with 10[2]/ml) that were considerably lower than the titers of 13 patients (one with 10[2]/ml, eight with 10[3]/ml, and four with > or = 10[4]/ml) without such clearance. The decrease in alanine aminotransferase levels paralleled the response of HCV RNA but not that of GBV-C RNA to interferon. The response of HCV at 6 months after interferon in the co-infected patients (4/16 or 25%) did not differ significantly from that in patients without GBV-C infection (44/124 or 35%). CONCLUSIONS: The sensitivity of GBV-C to interferon is comparable to but independent of HCV. Co-infection with GBV-C does not influence the response to interferon of patients with chronic hepatitis C.

Antiviral Agents↗
PubMed1997

[Effect of cessation of erythromycin therapy on diffuse panbronchiolitis].

The effect of cessation of erythromycin (EM) therapy against diffuse panbronchiolitis was studied. Nine cases were examined. After cessation of EM therapy, the manifestations of disease were stable in five cases, but worsened in the other four. In the former five, the period from the onset of disease until EM therapy began was relatively short; when EM therapy was stopped the manifestations of disease had almost completely disappeared and chest roentgenography revealed resolution of diffuse, small, nodular opacities without remarkable bronchiectasis. In contrast, in the latter four cases, the clinical manifestations of disease did not disappear, and chest-roentgenographic evidence of bronchiectasis was common before the cessation of EM therapy. In conclusion, EM therapy for diffuse panbronchiolitis may be stopped if the clinical manifestations of disease (especially purulent sputum) disappear, if diffuse, nodular opacities resolve almost completely and if there is no evidence of bronchiectasis.

Adolescent↗
PubMed1997

[Anesthesia in two patients with essential thrombocythemia].

Case 1. The patient was a 69-year-old man with essential thrombocythemia (ET), who underwent urgent laparotomy. On admission he was dehydrated and the platelet count was more than 160 x 10(4).microliter-1, with hematocrit of 50%. Anesthesia was induced with ketamine i.v. and maintained with nitrous oxide and sevoflurane in oxygen. Postoperative care included the administration of gabexate mesilate (GM) which is an antiplatelet agent. Case 2. An 84-year-old woman with ET was diagnosed as gastric cancer and elective gastrectomy was scheduled. The platelet count was more than 100 x 10(4).microliter-1. The patient was anesthetized with nitrous oxide and oxygen supplemented with fentanyl and mepivacaine via epidural catheter. Intravenous infusion of GM was performed at a rate of 1 mg.kg-1.hr-1 during surgery. PF-4 and beta-TG were measured. These are platelet releasing factors. The level of PF-4 decreased to normal level during this procedure. In conclusions, it will be important to use GM during anesthesia in order to avoid the complications such as myocardial or pulmonary infarction caused by thrombocythemia.

Aged↗
PubMed1997

Electroporation and bleomycin in glaucoma-filtering surgery.

PURPOSE: To develop a new treatment in glaucoma-filtering surgery using combined treatment with electroporation and the antiproliferative drug bleomycin. METHODS: Pigmented rabbits were treated with both bleomycin (10 micrograms/ml) and localized electric pulses (EP) using a special probe (5 V/cm, 100 msec, 8 pulses) (n = 10; group A). After EP treatment, bleomycin was washed out with 50 ml balanced salt solution, and then a posterior lip sclerectomy was performed on the same area. We also studied rabbits undergoing a posterior lip sclerectomy with bleomycin treatment alone (n = 10; group B), a posterior lip sclerectomy with EP treatment alone (n = 5; group C) and a posterior lip sclerectomy alone using the same operation (n = 5; group D, negative control). The intraocular pressure (IOP) was measured before and 1, 3, 5, 7, 10, 15, and 20 days after surgery. The formation of blebs, the conjunctiva, and the cornea were periodically examined by slit-lamp biomicrography. RESULTS: In every group, the IOP decreased until day 7, and no significant difference was observed among the four groups. In groups B, C, and D (control), the IOP increased gradually from day 10 and thereafter returned to the preoperative level after 15 days. However, in group A, the IOP remained lower than the preoperative level for 20 days; it was also significantly lower than each of the other three groups (P < 0.01). The survival rate of a filtering bleb was significantly higher in group A than in groups B, C, or D, but the survival rate in group B was not higher than groups C or D. No adverse effects were clinically observed in the ocular tissue, such as the cornea and conjunctiva. CONCLUSIONS: The combined treatment with EP and bleomycin was found to decrease IOP more prominently than EP or bleomycin treatment alone in filtering surgery. This treatment thus makes filtering surgery effective by decreasing the dose of the antiproliferative drug and by possibly localizing the drug delivery.

Animals↗
PubMed1997

[Characteristics of home parenteral nutrition and effectiveness of 3 way valved PICC in regional medical care].

Home medical care is becoming a greater matter of concern along with the increasing population of elderly persons. The various difficulties in home care are also found in regional care, and it could be said that in Japan regional care serves as an "advanced model" for home medical care. Ohya Town is located in the mountains of northern Hyogo Prefecture. It has a population of about 5,000 of which 32% is elderly people. There is no railroad, and it takes around 30 minutes to travel to the central hospital from the area. The three town clinics are in contact with each other and with the central hospital concerning medical information. The characteristics of Home Parenteral Nutrition in this underpopulated district are discussed and reported in reference mainly to cases in which the 3 way valved peripherally inserted central venous catheter (Groshong Catheter) is used, in comparison with HPN cases in the city university hospital.

Catheterization, Central Venous↗
PubMed1997

[Intraocular neovascularization].

To investigate the mechanism of intraocular neovascularization, we studied how vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) are expressed in the ocular tissues under hypoxic conditions. Prior to proliferation of vascular endothelial cells resulting in neovascularization, the retinal tissues such as pericytes, retinal glial cells, ganglion cells, and ciliary epithelium react directly to hypoxia expressing VEGF and/or IL-8 and stimulate endothelial cell proliferation in a paracrine manner. We demonstrated that transcription factor activator protein-1 (AP-1) is activated for expression of VEGF messenger ribonuculeic acid (mRNA) and in a similar way nuclear factor kappa B (NF-kappa B) is activated for expression of IL-8 mRNA. However, hypoxia-induced expression of VEGF and/ or IL-8 is only one aspect of the complicated processes in intraocular neovascularization. We hope that further detailed analysis of the mechanism will make it possible to inhibit and treat clinically intraocular neovascularization in the near future.

Adult↗