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Biomedical subjects

T Machi

Publications and source records attributed to T Machi.

At least 19 recordsLinked to original sources
PubMed2002

New type of vortex pinning structure effective at very high magnetic fields.

We report on a new type of correlated nanometer-scale pinning structure observed in a melt-processed (Nd0.33Eu0.38Gd0.28)Ba(2)Cu(3)O(y) (NEG-123). It consists of NEG/Ba-rich clusters in the stoichiometric NEG-123 matrix forming a lamellar array with a period of a few nanometers. These lamellas appear within regular twins, thus representing their fine substructure-sometimes straight, sometimes wavy. This new material structure correlates well with the significant enhancement of pinning at high fields, represented by irreversibility field above 14 T at 77 K (B parallel c). We believe that the new pinning medium enables one to significantly broaden the limits for high-field applications.

Journal Article↗
PubMed2001

[Cat scratch disease showing clinical picture resembling tuberculous lymphadenitis: a case report].

On February 18th, 1997, a 61-year-old woman visited our hospital because of a left inguinal mass. On physical examination, the mass was soft without inflammatory sign. About one month later, the node was excised. Pathological examination revealed granulomas with caseous necrosis and Langhans giant cells, suggesting tuberculosis, although acid fast stain was negative. Thereafter, re-history taking in detail disclosed that a kitten had often scratched her. We reexamined the pathology and checked her for serum antibodies to Bartonella henselae, the etiological microbe of cat scratch disease (CSD), using enzyme immunoassay. Histopathological reexamination of the excised mass revealed suppurative granulomas in addition to caseous ones. The level of IgG (negative: < 12 units) to B. henselae was 78 units on March 25th, 138 units on April 19th, and 18 units on July 18th, while the level of IgM (negative: < 12 units) was negative at each determination. These serological results strongly suggested current infection of B. henselae. The diagnosis of CSD could be established based on the history and the laboratory findings. When one encounters a case of granulomatous lymphadenitis, CSD should be considered for the differential diagnosis, and in this regard, anamnesis about contact with cats should be asked.

Animals↗
PubMed1999

[Extravasation of contrast media in acute subdural hematoma during three-dimensional CT angiography: a case report].

We report a case of acute subdural hematoma in which extravasation of contrast medium was demonstrated using three-dimensional computed tomographic angiography (3D-CTA). An 83-year-old man was found lying down on the floor but he was conscious. Thirty minutes later, he lost consciousness and was transferred to our hospital in a comatose state with right hemiparesis. Plain CT scan showed a left temporoparietal acute subdural hematoma with subarachnoid hemorrhage. CT scan also demonstrated an iso-density area beneath a high-density around the left Sylvian fissure. We performed an emergent 3D-CTA to rule out ruptured aneurysm as the cause of hemorrhage. However, 3D-CTA revealed no cerebral aneurysm, but extravasation of contrast medium from the cortical artery of the left temporal cortex was noted. The patient immediately underwent total evacuation of subdural hematoma by small temporoparietal craniectomy under local anesthesia. We found 3D-CTA to be a useful, less-invasive method for diagnosing the hemorrhagic cause and localizing the bleeding point. It is expected that with more routine use of 3D-CTA in patients with acute subdural hematoma, extravasation of the contrast medium will be seen more frequently. Subdural hematoma with extravasation of contrast medium required emergent surgery, and 3D-CTA findings facilitated the selection of the surgical method according to the bleeding point.

Acute Disease↗
PubMed1998

Prolonged respiratory failure in chlamydia pneumoniae pneumonia.

We describe a 65-year-old man, who had cardiomyopathy and developed acute respiratory failure requiring ventilator treatment. Acute pneumonia caused by Chlamydia pneumoniae was diagnosed based on PCR positivity of bronchoalveolar lavage. Gas exchange did not improve in response to appropriate antibiotic therapy, and the patient died.

Acute Disease↗
PubMed1997

Severe chest pain due to gastric anisakiasis.

We treated two cases of gastric anisakiasis presenting with severe chest pain. In both cases, there was a history of prior ingestion of raw saltwater fish. After endoscopic removal of larvae, the chest pain disappeared and never recurred. Other diseases causing chest pain were ruled out by symptoms, signs, blood tests, electrocardiography, chest radiograph, and ultrasonic examination of the heart and abdomen. Thus the chest pain was considered to be caused by gastric anisakiasis. Gastric anisakiasis should be included in the differential diagnosis of acute chest pain.

Adult↗
PubMed1997

Mediastinal lymphadenitis associated with Chlamydia pneumoniae infection.

A young woman presented with mediastinal lymphadenitis and measles-like eruption. All clinical manifestations promptly responded to macrolide therapy. Serologically, current infection of Chlamydia pneumoniae was highly suspected. Evaluation of Chlamydia pneumoniae infection should be included in the diagnostic approach to mediastinal lymphadenitis.

Adolescent↗
PubMed1996

Surgical control of akinesia in Parkinson's disease.

Posteroventral pallidotomy (PVP) was carried out in 86 patients with Parkinson's disease, who presented marked bradykinesia, freezing of gait and postural defect associated with rigidity and tremor in 82 patients (bradykinesia type), and similar gait and postural problems with minimum signs of rigidity and tremor in 4 (pure akinesia type). The stereotactic coordinates of Leksell's device were calculated from MRI and conventional ventriculography. The final target was defined by microelectrode techniques in the basal ganglia. The microrecording study revealed a very high background activity in the internal pallidum in patients of the bradykinetic type, however, a much lower pallidal activity in patients of the pure akinesia type. Fifty-eight patients underwent unilateral PVP, and 28 underwent bilateral surgery. Following PVP, rigidity tremor and poor reciprocal movements were significantly improved especially in the contralateral extremities. The most dramatic findings were the reversal of akinetic symptoms and wearing-off phenomena. The patients were followed up for 3-30 months (mean = 8) after surgery. Of the 82 bradykinesia type patients, good result were obtained in 48 (58%), fair results in 26 (32%), and minor improvement or no change in 8 (10%). In all the 4 patients of the pure akinesia type, recurrence of the akinetic symptoms occurred after a temporal improvement lasting a few days to 3 month after surgery. There was worst dysarthria in 3 patients, hemiparesis in 1 and partial motor aphasia in 1. The visual field problem was not complicated in any patients. These findings suggest that akinetic symptoms in PD are implicated in overactive pallidal outputs with putative GABAergic modulator by excessively inhibiting pedunculopontine nucleus activity (midbrain locomotor and posture regions) as well as thalamic activity. Partial interruption of the pallidal efferents eliminates the akinetic symptoms by disinhibitory effects on the target structures. The pathology of PD of the pure akinesia type is supposedly in the brainstem and should be excluded from indication of pallidotomy.

Adult↗
PubMed1996

Effect of mannitol on the permeability of cultured endothelial cells.

The effect of mannitol on the permeability of the endothelial monolayer was investigated. Endothelial cells from bovine major cerebral arteries were cultured on a polycarbonate membranes of the double chamber culture system. After the monolayers reached confluence, they were incubated with three kinds of mannitol solution either on the upper chamber or the lower chamber. Evan's blue conjugated bovine serum albumin was used as a marker of vasopermeability and added into the upper chamber solution. The density of the dye that passed through the monolayer was measured by a spectrophotometer. When the solution of the lower chamber was Hepes buffered salt solution (HBSS), permeability was maximum with the 20% mannitol solution in the upper chamber. When the solution of the lower chamber was 20% mannitol, permeability was maximum with HBSS in the upper chamber. When the solution of the lower chamber was 10% mannitol, permeability was minimum with the 10% mannitol solution in the upper chamber. These findings suggested that endothelial cells increase vasopermeability according to gradient of the concentration of mannitol between the intraluminal side and the abluminal side, and not due to the hyperosmolarity itself. Hyperosmolar urea made the endothelial cells shrink, while hyperosmolar mannitol solution did not induce such shrinkage. Therefore a difference in the mechanism of increasing vasopermeability by mannitol and urea was suggested.

Animals↗
PubMed1996

Hemoglobin damages the cultured endothelial cell monolayer from bovine cerebral arteries.

We demonstrated that hemoglobin reaches the endothelial layers by an immunoelectron microscopic analysis in a rabbit subarachnoid hemorrhage model. Next, the effects of hemoglobin on cerebral artery endothelial cells were investigated both morphologically and histochemically using a cultured monolayer from a bovine endothelial cell system. The cultured monolayer was incubated with six different concentrations of hemoglobin ranging from 0 to 10(-5) M for 24 hrs on two-chambered glass slides. The denuded area of the glass slide increased dose dependently while the intensity of the actin fiber decreased. Superoxide dismutase did not modify this change. In a preliminary study, the endothelial cell membrane showed a hemoglobin binding molecule (94.5k dalton). This study thus suggests that the effects of hemoglobin on the endothelial monolayer were partly caused by the direct binding of hemoglobin to the membrane.

Animals↗
PubMed1995

Parvovirus infection and generalized edema in adults.

We describe the clinical and laboratory findings of 7 adult patients with serological evidence of recent human parvovirus B19 (HPV) infection who presented with generalized edema. Six of the 7 patients had household contact with children with erythema infectiosum and had flu-like symptoms before visiting hospital. The interval between the flu-like episode and the development of edema ranged from 4 to 13 days (mean 7.0). In all 7 patients, there was serological confirmation of recent HPV infection, and all showed the development of edema following HPV infection without urine abnormalities or anemia. Two patients presented hypocomplementemia, and two patients showed signs of congestive heart failure. HPV may be considered a causative agent of generalized edema not only in the fetus but also in adults and HPV infection should be included in the differential diagnosis of generalized edema formation.

Adult↗
PubMed1995

Severe hypercalcemia and polyuria in a near-drowning victim.

A 73-year-old man was admitted because of near-drowning in a hot springs bath. Transient severe hypercalcemia and polyuria were seen during the first hospital day. It seemed that the hypercalcemia was due to acute intoxication from calcium contained in the water of the spring absorbed mainly through the alveoli. To our knowledge, this is the first case of acute hypercalcemia complicating a near-drowning in a hot spring. Analysis of serum and urine electrolytes during the polyuric phase revealed saline diuresis, which was probably due to interference by the hypercalcemia of the reabsorption of sodium and free water.

Aged↗
PubMed1995

Adult-onset Still's disease with submassive hepatic necrosis.

We present a 74-year old woman who was hospitalized because of typical spiking fever, evanescent rash, polyarthralgia, lymphadenopathy, and marked elevation of serum transaminases and lactate dehydrogenase (LDH) due to adult-onset Still's disease (AOSD) with submassive hepatic necrosis. All of the symptoms and abnormal laboratory findings were dramatically improved after treatment with prednisolone. The clinical course of this patient indicates that AOSD with severe hepatic necrosis can successfully be treated with early administration of corticosteroid, although it remains unknown whether the disease can remain in remission with no or minimal treatment.

Aged↗