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Biomedical subjects

M Sakai

Publications and source records attributed to M Sakai.

At least 271 records · Page 15Linked to original sources

Regression of an aggressive abdominal desmoid tumor in a patient with familial adenomatous polyposis by hyperthermoradiotherapy.

A case of huge desmoid tumor successfully treated by hyperthermoradiotherapy is described. A 23-year-old man with familial adenomatous polyposis was operated upon for a desmoid tumor in the mesenterium involving the right kidney and small intestine in 1988. In 1990, the tumor recurred and could not be resected because of the involvement of the vena cava. The tumor grew larger and larger, and occupied two-thirds of the right lower quadrant. Several therapies using sulindac, tamoxifen, prednisolone, indomethacin, luteinizing hormone-releasing hormone analogue, and ascorbate were all ineffective. Finally, the combination of radiation and hyperthermia was used over a 6-month period. At the end of the hyperthermoradiotherapy, the tumor in the abdominal wall was markedly reduced in size, and the protruded abdominal wall became flat. To our best knowledge, this is the first report of the successful treatment of a huge desmoid tumor by hyperthermoradiotherapy.

Adenomatous Polyposis Coli↗

[Tuberculosis in the crew of a submarine].

We report the apparent spread of mycobacterial tuberculosis among a submarine crew from a crew member with a low grade of infectivity. The air-conditioning system of submarines requires completely closed recirculation of ambient air. If a person with pulmonary tuberculosis were in a submarine, one would expect to find a high incidence of tuberculosis among others on the ship. The index patient was a 35-year-old member of a submarine crew. An abnormal shadow was found on a chest roentgenogram during an annual medical checkup, and he was hospitalized for examination. Acid-fast bacilli were found in his gastric secretions, but he did not complain of coughing and no tuberculosis bacilli were found in his sputum. All members of the submarine crew were examined, and some who were on board with the index patient reacted strongly. Because those who were also suspected to be infected were usually not close to the index patient's living quarters and had little contact with the patient in the submarine, we strongly suspect that the closed ventilation system contributed to the spread of the infection. Control of tuberculosis in a sealed environment requires detailed investigation of the environment and completion of chemoprophylaxis. Adequate ventilation and ultraviolet radiation are more effective than decontamination with disinfectants for the control of infectious droplet nuclei. Ships should be equipped with those systems.

Adult↗

Application of autogenic training for anxiety disorders: a clinical study in a psychiatric setting.

The effects of autogenic training for anxiety disorders were investigated in a psychiatric setting of a medical school hospital and the predictors of this treatment outcome were identified. Fifty-five patients who meet the DSM-III-R criteria for anxiety disorders were treated individually with autogenic training by the author from October 1981 to October 1995. The medical records of the patients were investigated retrospectively. The results showed that the autogenic training was successful. Twenty-eight patients (51%) were cured, fourteen (25%) much improved, eight (15%) improved and five (9%) unchanged at the end of the treatment. Forty-two patients (76%) were assessed as having had successful treatment. Pretreatment variables, such as patient's clinical characteristics, did not provide a useful guide to the outcome. Four treatment variables did have a bearing on outcome. First, practicing the second standard autogenic training exercise was a satisfactory predictor of a better outcome. Second, practicing generalization training also was a useful predictor. Third, the application of other behavioral treatment techniques was found to be positively associated with outcome. Fourth, longer treatment periods were associated with a better outcome. These findings suggested that autogenic training could be of significant benefit for the treatment of anxiety disorders.

Adolescent↗

[Twenty cases of superior septal approach for mitral valve operation].

We experienced 20 cases of superior septal approach (SSA) for mitral valve surgery from June 1992 to December 1995. From pre-operative coronary angiography, sinus node arteries (SNAs) were grouped into three types, branched from right coronary artery (RCA: 45%), from left circumflex (LCx: 35%), and from both RCA and LCx (Bilateral: 20%). And, in diameter, they were grouped into two groups, above 1 mm (80%) and below 1 mm (20%). There were no peri-operative deaths and complications associated with SSA. In acute post operative phase, atrial fibrillation, junctional rhythm, atrial flutter, and sino-atrial block were observed, especially in patients whose SNA branched from RCA, and were above 1 mm in diameter. In late follow-up, all patients' rhythm returned to pre-operative rhythm, although some cases became bradycardia less than 60 per-minute. Bradycardia was observed in patients whose SNA branched from RCA, and were above 1 mm in diameter. There may be relationship between post operative arrhythmia and division of large SNAs originated from RCA. We concluded that SSA is safe and excellent approach for mitral valve surgery, especially in patients who require reoperations and in patients with small LA, although we should consider the advantages of SSA versus the risks of post operative arrhythmia and bradycardia.

Adult↗

Expression of endothelial nitric oxide synthase in human eccrine clear cells.

Nitric oxide is generated from L-arginine by nitric oxide synthase (NOS), which has at least three isoforms; endothelial-type NOS (eNOS) and brain-type NOS (bNOS) are constitutive enzymes, and inducible-type NOS (iNOS) is expressed after stimulation. Studies by the avidin-biotin immunocomplex method, revealed eNOS immunoreactivity exclusively in the human eccrine clear cells. No eNOS immunoreactivity was observed in the eccrine dark cells or myoepithelial cells. No staining of iNOS or bNOS was observed in the eccrine gland. These findings indicate that NO plays a physiological part in the production and/or excretion of sweat in the human skin eccrine gland.

Adult↗

Cause and repair of flap necrosis over cochlear implant.

OBJECTIVE: The aim of this report was to study the cause and treatment of flap-related complications over cochlear implant. SETTING: The study was performed in an academic tertiary referral center. PATIENT: A 53-year-old Japanese male patient had had two retro-auricular skin incisions for tympanomastoidectomy in the postauricular region before implantation of a cochlear implant. He also had worn a helmet daily during work in his factory. INTERVENTIONS: Corrective surgery was performed for reformation of the local blood supply to the overlying skin flap and reinforcement of the tissue overlying the implant by use of a superiorly based temporal muscle and fascia flap that were sutured with an inferiorly based muscle and fascia flap. RESULTS: We successfully transposed the flap covering the implant without explantation of the implant. CONCLUSIONS: The delayed development of flap necrosis was thought to be due to pressure necrosis produced by the band in the patient's helmet lying on the skin over the implant and to poor local blood supply in the postauricular area stemming from the two previous skin incisions for mastoid surgery performed for cholesteatoma. In those patients who wear helmets, it is important to position the cochlear implant sufficiently behind the ear and to avoid the use of a helmet.

Cochlear Implants↗

Differential expression of maf-1 and maf-2 genes in the developing rat lens.

PURPOSE: To examine the expression of maf-1 and maf-2 protocogenes in the developing rat lens. METHODS: Maf-1 and maf-2 transcripts were assayed in rat lenses on embryonic days 13 and 16 (E13 and E16) by in situ hybridization using single-stranded RNA probes. Proteins encoded by the maf-2 gene were assayed immunocytochemically in embryonic (E12, 13, 16, 19) and postnatal day 14 and 90 (P14 and P90) lenses. RESULTS: In embryonic lenses, we detected maf-1 messenger RNA (mRNA) in the lens epithelium and maf-2 mRNA diffusely distributed in the lens fiber cells. By immunocytochemistry, Maf-2 was detected on E12 in the nuclei of almost all lens pit cells. On days E13, E16, and E19, however, lens epithelial cells showed no immunoreactivity, but nuclei of fiber cells reacted strongly. On P14, nuclei containing Maf-2 protein were confined to the equator of the lens, but at 3 months of age, no Maf-2 could be detected in the rat lens. Western blotting showed that the anti-Maf-2 antiserum reacted with a single protein, of molecular weight approximately 39 kDa, in rat lens. CONCLUSIONS: Results showed the spatial and temporal regulation of maf gene expression and suggest that these genes participate in transcriptional regulation during the development of the lens in the rat.

Animals↗

A statistical study of fistula auris congenita in Japan.

A statistical study of the occurrence, in Japan, of fistula auris congenita was conducted in 15,114 subjects (8,018 elementary school and 7,096 junior high school students) in Kanagawa, Shizuoka, and Wakayama Prefectures. The incidence of fistula auris congenita was 2.6% (396 of 15,114 students). Many cases were unilateral and exhibited a single manifestation. The fistula sites were mainly in the preauricular region. Only 2.3% of the 396 fistula cases had a history of radical operation.

Child↗

Visual-vestibular interaction--an evoked potential study in normal human subjects.

Positron emission tomography (PET) was used to demonstrate temporary down-regulation of visual cortex activities associated with eye movements. The aim of the present study was to test this paradigm with visual evoked potentials (VEPs) in the visual cortex of 7 healthy human subjects during caloric nystagmus. Caloric stimulation was performed by irrigating the right or left external ear canals with 100 ml of warm water at 44 degrees C for 50 s with a head position of 60 degrees tilted backward in order to stimulate the horizontal semicircular canal. The subjects kept their eyes closed during and after caloric stimulation. For recording the VEPs, the flashlight was used for activating the visual cortex with the subject's eyes closed. In the 7 subjects, no significant difference was detected between the VEPs induced with and without caloric stimulation.

Adult↗

The scavenger receptor serves as a route for internalization of lysophosphatidylcholine in oxidized low density lipoprotein-induced macrophage proliferation.

We have recently demonstrated that the growth of murine macrophages is induced by oxidized low density lipoprotein (Ox-LDL) and that lysophosphatidylcholine (lyso-PC), a major phospholipid component of Ox-LDL, plays an essential role in its mitogenic effect. The present study was undertaken to further characterize the role of the macrophage scavenger receptor (MSR) in Ox-LDL-induced macrophage growth. The growth-stimulating effect of Ox-LDL on murine resident peritoneal macrophages was inhibited by maleylated bovine serum albumin (maleyl-BSA), a non-lipoprotein ligand for MSR but a poor carrier of lyso-PC, while maleyl-BSA itself failed to induce macrophage growth even in the presence of lyso-PC. Moreover, it competitively inhibited the endocytic uptake of 125I-Ox-LDL and the specific uptake of lyso-PC by MSR, whereas nonspecific lyso-PC transfer to cells was not affected. Furthermore, the Ox-LDL-induced cell growth of peritoneal macrophages obtained from MSR knockout mice was significantly weaker than that of macrophages obtained from their wild-type littermates. Our results suggest that the MSR is an important and efficient internalization pathway for lyso-PC in Ox-LDL-induced macrophage growth.

Albumins↗

Transient appearance of GTP cyclohydrolase I--positive non-monoaminergic neurons in the ventral lateral geniculate nucleus of postnatal mice.

The transient appearance of GTP cyclohydrolase I (GCH)-immunoreactive (ir) cells in the ventral lateral geniculate nuclear region of mice was detected by use of an avidin-biotin peroxidase complex method with an antibody specific for an oligopeptide of rat GCH (residues from 12 to 23, GFPERELPRPGA). In this brain region, we found for the first time novel GCH-ir cells already at postnatal day 1 (P1). The numbers reached maximum at P14 and decreased until P29, and they had mostly disappeared by P56. These cells were tyrosine hydroxylase negative and aromatic L-amino acid decarboxylase negative, indicating a lack of dopamine or serotonin production, and thus do not belong to the monoaminergic neuron system.

Age Factors↗

Lipoprotein(a) induces cell growth in rat peritoneal macrophages through inhibition of transforming growth factor-beta activation.

To elucidate the atherogenicity of lipoprotein(a) (Lp(a)), we examined its growth-stimulating activity in rat resident peritoneal macrophages. When macrophages were incubated with Lp(a), cell numbers were increased 1.5-fold as compared with control macrophages. Furthermore, apolipoprotein(a) (apo(a)), a plasminogen-like glycoprotein which is covalently attached to a low density lipoprotein-like particle (Lp(a)), also induced macrophage growth, while the growth-stimulating effect of Lp(a-) was negligible. These results suggest that apo(a) plays an active role in the mitogenic activity of Lp(a). Lp(a)-induced macrophage growth was inhibited by exogenously added active transforming growth factor-beta (TGF-beta) dose-dependently, and also by the addition of plasmin, which converts latent TGF-beta to an active form. Moreover, the amounts of endogenous active TGF-beta in the medium were significantly reduced by the incubation with Lp(a). It is evident from these results that Lp(a) induces macrophage growth by inhibiting TGF-beta activation. The capacity of Lp(a) to stimulate macrophage growth shown here could be novel atherogenic function of Lp(a).

Animals↗

Evidence of a direct action of taurine and calcium on biological membranes. A combined study of 31P-nuclear magnetic resonance and electron spin resonance.

To determine the actions of taurine and calcium on biological membranes, the effects of these compounds on the mobility of phospholipids of resealed and sonicated ghosts of human erythrocytes were investigated, using 31P-NMR spectroscopy. In addition, the effects of taurine and calcium on lipid fluidity were investigated by ESR spectroscopy, using a spin-labeling method with 5-doxyl stearic acid. The mobility of the membranes decreased following treatment with 10 mM taurine, but coadministration of 2.5 mM calcium blocked this effect. The fluidity of the membranes was not changed following treatment with 10 mM taurine, but decreased following coadministration of 2.5 mM calcium. These actions of taurine and calcium on the dynamics of biological membranes might explain, in part, the observation that most of the pharmacological effects of taurine on mammalian organs occur in the presence of calcium ions.

Calcium↗

Transient appearance of tyrosine hydroxylase-immunoreactive non-catecholaminergic neurons in the medial geniculate nucleus of postnatal mice.

Tyrosine hydroxylase-immunoreactive (TH-ir) cells were found to appear transiently in the medial geniculate nuclear region of mice at postnatal day 7 (P7) by use of an avidin-biotin peroxidase complex (ABC) method for the first time. The numbers of TH-ir cells reached maximum between P14 and P21 and decreased until P29. These cells were GTP cyclohydrolase I-negative, aromatic L-amino acid decarboxylase-negative, and dopamine-negative. Thus, they do not belong to the catecholaminergic neuron system, because they lack dopamine production. The results suggest that TH in the cells in the medial geniculate nuclear region of mice has some new functions besides catecholamine biosynthesis.

Animals↗