PubMed Health⌕ Search

Biomedical subjects

M Hara

Publications and source records attributed to M Hara.

At least 523 records · Page 29Linked to original sources
PubMed1995

Silent cortical strokes associated with atrial fibrillation.

To clarify whether silent cortical strokes (SCS) could be a predictor of symptomatic stroke in patients with atrial fibrillation (AF), 72 patients with AF (50 with chronic AF, 22 with paroxysmal AF) were studied. Patients with mitral stenosis, history of myocardial infarction, or dilated cardiomyopathy were excluded from this study. Using cranial magnetic resonance imaging (MRI), the patients were divided into those with SCS (23 patients, Group 1) and those without SCS (49 patients, Group 2). The incidence of symptomatic stroke was then compared between the two groups. Three patients (13%) in Group 1 developed symptomatic brain infarction; this is statistically significant (p < 0.05), compared with the patients in Group 2, none of whom experienced symptomatic stroke. We suggest that SCS is a predictor of symptomatic cerebral infarct in patients with AF. Therefore, it is thought to be important to diagnose SCS using cranial MRI or computed tomography and to keep patients with SCS under close surveillance.

Aged↗
PubMed1995

Proteoglycans in haemodialysis-related amyloidosis.

Changes in extracellular matrices of articular tissue, intervertebral discs and systemic organs in patients with haemodialysis-related amyloidosis were investigated by immunohistochemical and biochemical examination of proteoglycans. Increased staining for chondroitin sulfate (CS) was detected in the amyloid deposits of all patients, ranging from early to advanced stages. Degenerative tissue changes around early-stage amyloid deposits in the intervertebral discs also showed positive staining for CS. Heparan sulfate (HS) was detected in amyloid deposits, especially in the synovial membrane. Biochemical analysis of connective tissues containing amyloid supported the immunohistochemical studies; CS was the major glycosaminoglycan species in these tissues, accounting for 55-81% of the total glycosaminoglycans. Although previous studies have stressed the importance of HS in amyloidogenesis, the present study showed that CS, which increased significantly in articular tissues associated with mechanical stress, also has a close relationship with amyloidogenesis.

Adult↗
PubMed1995

CSF shunt physics: factors influencing inshunt CSF flow.

Cerebrospinal fluid (CSF) in a shunt does not have a constant flow rate. The flow fluctuates from 0.01 ml/min to 1.93 ml/min according to each patient's own daily supine rhythmic pattern. We determined and evaluated the factors influencing CSF flow in a shunt in 19 cases of hydrocephalus. Postural changes, such as head elevation, led to increases by over 0.04 ml/min in inshunt CSF flow, while inshunt CSF flow in the supine position was less than 0.04 ml/min. Respiratory changes, such as coughing and apnea-hyperventilation, also influenced inshunt CSF flow. Changes in intracranial pressure (ICP) corresponded to changes in inshunt CSF flow. Inshunt CSF flows were higher than average during the night, the flows being stimulated by increases in ICP especially during REM sleep.

Adolescent↗
PubMed1995

Choroid plexus papilloma of the III ventricle in an infant.

A case of choroid plexus papilloma of the III ventricle associated with hydrocephalus in an 1-month-old boy is reported. The tumor was removed after placement of a ventriculoperitoneal shunt; however, the histologically mainly benign tumor grew very rapidly. The cause of this rapid growth may have been a drop in the intraventricular pressure after the shunting procedure.

Cerebral Ventricle Neoplasms↗
PubMed1995

Cine magnetic resonance imaging of aqueductal stenosis.

Cerebral aqueductal stenosis is one of the most common causes of congenital and acquired hydrocephalus, but the etiology, pathophysiology and cerebrospinal fluid (CSF) dynamics of aqueductal stenosis have yet to be clarified. Utilizing cardiac gated cine magnetic resonance (MR) imaging, we evaluated aqueductal configuration and pulsatile motion of brain and CSF flow stimulated by cardiac pulsation in five patients with non-tumoral aqueductal stenosis. Cine MR of four cases revealed obliteration of the aqueduct by thickening mesencephalic tectum, turbulent CSF flow in the III ventricle, and absence of flow-related signal void, which in all normal cases indicates CSF movement within the aqueduct. In the remaining fifth case, with proximal dilation of the aqueduct resulting from thinning of the tectum, distortion of caudal (distal) tectum related to pulsatile motion of the brain caused funnel-like narrowing of the aqueduct, leading to incomplete obstruction and the absence of upward CSF flow during diastole.

Adult↗
PubMed1995

Cavernous malformations of the optic chiasma.

Two cases of cavernous malformation of the optic chiasm are reported, and 12 previously reported cases are reviewed. The first patient presented with gradually progressive and the second patient with a subacute chiasmal syndrome. Total excision was performed in both cases. Visual function improved slightly after surgery in the first patient while the other showed marked improvement. Although cavernous malformations are angiographically occult, pre-operative diagnosis has become possible based on the characteristic features such as repeated haemorrhages in multiple sinusoidal structures as revealed by magnetic resonance imaging (MRI). A gliotic interspace between the malformation and normal neural tissue provides a plane of cleavage for dissection which permits total excision without causing new deficits. Review of previously reported cases revealed that chiasmal cavernous malformations haemorrhage more frequently than those in the brain. Early diagnosis with total excision is the treatment of choice for cavernous malformations of the optic chiasma.

Adolescent↗
PubMed1995

Bone metastasis from colorectal cancer in autopsy cases.

The incidence of bone metastasis from colorectal cancer is reported to be 10.7% in autopsy cases. However, the characteristics of the primary cancers, as well as the patterns of bone metastasis, remain unclear. We analyzed the clinical and autopsy records of 118 patients with primary colorectal cancer treated either surgically or conservatively and eventually autopsied between 1970 and 1987 at Toranomon Hospital in Tokyo. Bone metastasis was detected in 23.7% (28/118). The average age of patients with bone metastasis was lower than that in patients without bone metastasis (P < 0.02). Cancers to the rectum and cecum were accompanied by bone metastasis more frequently than cancers of other portions of the colon. Signet-ring cell carcinoma showed a high incidence of bone metastasis (P = 0.041). Bone metastasis from colorectal cancer was associated with liver or lung metastases (P < 0.0001). These results indicated that bone metastasis from colorectal cancer is not as infrequent as previously described.

Aged↗
PubMed1995

Potent protective effect of melatonin on in vivo paraquat-induced oxidative damage in rats.

The in vivo effect of melatonin on paraquat-induced oxidative damage in rat lung and liver was studied using two parameters: the concentration of malonaldehyde and 4-hydroxyalkenals as indices of lipid peroxidation; changes in total and oxidized glutathione. Melatonin (10 mg/kg) or an equal volume of saline were administered intraperitoneally (ip) to rats 30 min prior to an ip injection of paraquat (20 mg/kg or 70 mg/kg). After paraquat treatment, the animals received melatonin or saline ip injections every six hours for 24 hours. Rats were killed 24 hours after paraquat injection. In lung, both the low and high dose of paraquat, when administered with saline, augmented lipid peroxidation (100% and 18%, respectively) above levels found in control animals. Treatment with melatonin completely reversed this effect. In liver, paraquat (70 mg/kg) increased lipid peroxidation by 40% over the levels of control animals. The increase was completely abolished by treatment with melatonin. Paraquat at 20 mg/kg did not induce any significant change in liver lipid peroxidation. Paraquat treatment resulted in a significant decrease of total glutathione concentration and increased oxidized glutathione in both lung and liver. These effects were abolished by treatment with melatonin. The results suggest that melatonin confers marked protection against paraquat-induced oxidative toxicity in both the lung and liver.

Aldehydes↗
PubMed1995

Function and distribution of a steroidogenic cell-specific transcription factor, Ad4BP.

Ad4BP was identified as an essential transcription factor regulating steroidogenic cell-specific and cAMP-dependent transcription of the genes of steroidogenic P450s. The Ad4BP transcript was detected in steroidogenic tissues such as adrenal gland, testis, ovary, placenta and brain by RT-PCR, and showed good correlation with the expression of steroidogenic P450s. The genes of steroidogenic P450s, which are transcribed only in steroidogenic cells, were transcribed in non-steroidogenic cells when an Ad4BP expression vector was introduced into the cells. To study the function of Ad4BP in the differentiation of the steroidogenic tissues, immunochemical and immunohistochemical studies were performed with the tissues prepared from various developmental stages of rats. Adrenal cortex expressed Ad4BP since the tissue was detected in the dorsal wall of the fetus. Gonadal tissues expressed Ad4BP in a sex-dependent manner. High levels of Ad4BP expression were detected in fetal and prepubertal testes and in prepubertal and adult ovaries, whereas low level expressions were observed in the adult testes and in the fetal ovaries. The expression of Ad4BP in the gonads correlates well with the expression of the Müllerian inhibiting substance gene as well as the steroidogenic P450 gene for both sexes. These observations indicate that Ad4BP plays an important role in the development and differentiation of the steroidogenic tissues including sexual differentiation of the gonadal tissues through activation of the transcription of its target genes.

Adrenal Glands↗
PubMed1995

Direct 99mTc labeling of human immunoglobulin with an insoluble macromolecular Sn(II) complex.

An insoluble macromolecular Sn(II)(R-Sn) complex which strongly binds Sn(II) by chelation was applied to the direct 99mTc labeling of human immunoglobulin(IgG) to minimize the influence of Sn(II). 99mTc labeling was achieved at greater than 90% yield simply by the short-term mixing of IgGa containing > 2-SH groups per IgG molecule, 99mTc pertechnetate, and the R-Sn complex in pH 7 solution. The 99mTc-IgGa obtained by this labeling method has high stability based on the thiol-specific binding of 99mTc without transchelation from another weakly bound 99mTc-complex.

Animals↗
PubMed1995

Endothelin-1 of keratinocyte origin is a mediator of melanocyte dendricity.

Melanocytes synthesize melanin and transfer it to keratinocytes via dendritic processes. Keratinocytes are known to produce constitutively several factors, including endothelin-1 (ET-1), that together affect melanocyte proliferation, migration, melanogenesis, and dendrite formation. After ultraviolet (UV) irradiation, synthesis and secretion of ET-1 are up-regulated in keratinocytes. Because UV irradiation of skin is known to be associated with increased melanocyte dendricity, and because medium conditioned by UV-irradiated keratinocytes (UV-KCM) induces melanocyte dendricity to a greater degree than does baseline keratinocyte-conditioned medium (KCM), we investigated whether ET-1 promotes melanocyte dendricity. ET-1, originally recognized as a vasoconstrictive peptide, has recently been shown to stimulate melanocyte proliferation and tyrosinase activity. We now report that ET-1 supplementation of cultured melanocytes significantly increases the percentage of dendritic melanocytes, as well as dendrite length, in a dose-dependent manner. Moreover, UV-KCM was found to contain over 25-fold more ET-1 than KCM, and ET-1 supplementation of KCM induced melanocyte dendricity comparable to that induced by UV-KCM. Further, melanocyte dendricity induced by UV-KCM was significantly inhibited by the addition of anti-ET-1 monoclonal antibody to the medium, suggesting that the UV-KCM effect on melanocyte dendricity is mediated largely through ET-1. Our findings suggest that in the skin, ET-1 of keratinocyte origin promotes melanocyte dendricity in response to UV irradiation.

Cells, Cultured↗
PubMed1995

Acrokeratosis paraneoplastica (Bazex syndrome) associated with primary cutaneous squamous cell carcinoma of the lower leg, vitiligo and alopecia areata.

We report a case of acrokeratosis paraneoplastica (AP; Bazex syndrome), characterized by typical palmoplantar hyperkeratosis and psoriasiform scaly erythema of the acral regions, associated with primary cutaneous squamous cell carcinoma (SCC) on the left lower leg. This 54-year-old Japanese man subsequently developed vitiligo, and alopecia areata of the scalp. Serial monitoring of squamous cell carcinoma antigen (SCC-Ag) demonstrated that the severity of the clinical manifestations of AP paralleled the serum concentrations of SCC-Ag. We suggest that an immune-mediated mechanism underlies the development of AP in this patient.

Alopecia Areata↗
PubMed1995

Lung cancer associated with usual interstitial pneumonia.

There were 83 cases of usual interstitial pneumonia (UIP) in 3712 consecutive autopsy cases during 1972 to 1992 in Toranomon Hospital. Primary lung cancer had arisen in 40 cases of UIP in that period. The prevalence of lung cancer (48.2%) in UIP was significantly higher than that of lung cancers (9.1%) in the age-matched general population without UIP (P < 0.001). The prevalence of association of multiple lung cancer in UIP (20.0%) was also significantly increased. Thus, UIP showed a remarkable potency to develop lung cancers. The lung cancer cases in UIP had obvious smoking habits. Both the rates of smokers and the quantity of smoking were significantly increased in the lung cancer cases in UIP (P < 0.05). There was a distinct anatomical distribution of lung cancer in UIP. Most cancers in UIP (98%) arose in the peripheral area of the lung (P < 0.001, compared to lung cancer cases without UIP) with close relation to the honeycombing lesion. Studies on surgical specimens with small cancers showed that most tumors in UIP arose in the border area between honeycombing and the non-fibrotic area. Thus, the front of the remodeling of the lung is suspected to be a potential field of developing lung cancer. The chronic inflammatory process resulting in the remodeling of the lung may play an important part in the development of lung cancer in UIP under the circumstance of heavy smoking.

Adenocarcinoma↗
PubMed1995

Lipoprotein (a) and apolipoprotein A-1 and B in schoolchildren whose grandparents had coronary and cerebrovascular events: a preliminary study of 12-13 year old Japanese children.

The aim of this study was to evaluate the relationship between the serum levels of lipoprotein (a) [Lp (a)] and apolipoproteins (apo A-1 and apo B) in schoolchildren with a history of coronary and cerebrovascular events in their grandparents. We measured serum concentrations of Lp (a) and apoliproteins immunochemically in 289 schoolchildren aged 12-13 years and questioned parents about coronary and cerebrovascular events in the children's grandparents. In boys and girls, mean +/- s.d. levels of apo A-1, apo B and Lp (a) were 134 +/- 20.3 and 136 +/- 17.4 mg/dL, 61 +/- 16 and 66 +/- 15 mg/dL and 12.5 +/- 15.3 and 12.5 +/- 15.1 mg/dL, respectively. There were no significant sex differences in the levels of apo A-1, apo B, and Lp (a). The Lp (a) levels (mean +/- s.d., 12.5 +/- 15.2 mg/dL; median 7.5 mg/dL, n = 289) were not affected by other variables. The Lp (a) distribution was strongly positively skewed and 75% of schoolchildren had very low levels. In the total 289 schoolchildren, thirty-two grandparents who had had coronary vascular events (21 myocardial infarction, 11 angina pectoris) and twenty-three grandparents who had had cerebrovascular events were recorded. By the boxplot statistical analysis, no difference was found in Lp (a) levels in children whose grandparents had myocardial infarction compared with those whose grandparents had no such history, or compared with those whose grandparents had suffered cerebrovascular events.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Intra-abdominal fat in obese children.

We investigated the distribution of abdominal fat accumulation in obese children to know whether a clustering of coronary risk factors was demonstrated in visceral fat obesity as reported in adults. The relative indicator of intra-abdominal fat accumulation was obtained from computed tomography scans at the umbilicus level in 36 obese subjects (24 males, 12 females). There was no visceral fat obesity in this study by reported criteria. All metabolic variables except triglyceride did not correlate significantly with intra-abdominal fat accumulation. We conclude that visceral fat obesity is a rare status and has no close relationship to coronary risk factors in childhood.

Abdomen↗
PubMed1995

Keratinocyte degeneration in human facial skin: documentation of new ultrastructural markers for photodamage and their improvement during topical tretinoin therapy.

We examined epidermal impairment in photodamaged Caucasian skin by light and electron microscopy and observed two types of degeneration of the basal and suprabasal keratinocytes. The first was an electron-lucent degeneration predominantly seen in the periphery of the cells. The marked lucent degeneration occurred in 14% of the basal and suprabasal keratinocytes, predominantly in cells immediately adjacent to melanocytes. In skin specimens with a large number of such damaged keratinocytes, bleb-like keratinocytic protrusions or electron-lucent intercellular structures were also seen. Many vacuolar structures were observed just under the dermoepidermal junction, occupying 9% of the junction length. These structures were produced by herniation of the degenerative portion of the basal and suprabasal keratinocytes, and appeared to be phagocytized by dermal macrophages. The vacuolar alterations in the basal layer and dermoepidermal junction previously reported at the light microscopic level probably represent these intercellular lucent structures, bleb-like protrusions and vacuole-like structures at the electron microscopic level. The second type, dark-staining keratinocytes, probably representing an extensive degenerative process, constituted 4% of the basal and suprabasal keratinocytes. After 12 months of topical tretinoin treatment, dramatic improvement of both degenerative processes of the keratinocytes was noted.

Administration, Cutaneous↗