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Biomedical subjects

T Horikoshi

Publications and source records attributed to T Horikoshi.

At least 37 records · Page 2Linked to original sources
PubMed1999

Peripheral quantitative computed tomography of the femoral neck in 60 Japanese women.

Peripheral quantitative computed tomography (pQCT) is able to evaluate trabecular and cortical bone separately, and to determine geometric properties from cross-sectional images for noninvasive assessments of mechanical strength. In order to assess the diagnostic value of pQCT of the femoral neck, 60 healthy women were examined with a new pQCT machine, XCT-3000 (Norland-Stratec, Germany), which is suitable for direct measurement of the hip. The region of interest chosen was the center of the femoral neck. pQCT of the distal radius and dual energy X-ray absorptiometry (DXA) of the lumbar spine and femoral neck were also performed. The study demonstrated that total bone mineral density (BMD) (femoral MD) and trabecular BMD (femoral-TBD) decreased with advancing age. Percent cortical area showed a small but significant decrease with advancing age and % trabecular area increased slightly. Both the endosteal perimeter and the periosteal perimeter were relatively constant with aging. Bone strength index (BSI) and stress-strain index (SSI), which reflect the mechanical strength of bone, declined with advancing age, especially after menopause. Femoral TBD correlated strongly with femoral neck BMD by DXA and L2-L4 BMD by DXA but femoral-CBD did not correlate with femoral neck BMD by DXA. Volumetric BMD of the femoral neck and distal radius were closely correlated. It is concluded that (1) cortical thinning occurs with aging by endocortical resorption and loss of femoral-TBD; (2) loss of femoral-CBD occurred at a slower rate than radial CBD, perhaps due to the weight-bearing effect; (3) biomechanical parameters such as the BSI and SSI may reflect increasing fragility of the femoral neck in pre- and postmenopausal women; (4) pQCT of the femoral neck had diagnostic value at least equivalent to that of DXA or pQCT of the distal radius.

Absorptiometry, Photon↗
PubMed1999

Helicobacter pylori infection correlates with severity of reflux esophagitis: with manometry findings.

The role of Helicobacter pylori infection in the development and exacerbation of reflux esophagitis was investigated. The prevalence of Helicobacter pylori infection, the severity of atrophic gastritis, and esophageal motility (determined by esophageal manometry by an infusion catheter method) were assessed in patients with mild (n = 46) and severe (n = 27) reflux esophagitis and subjects without reflux (n = 28). Compared with the prevalence of Helicobacter pylori infection in the non-reflux group, the prevalence in the mild and severe reflux groups (60.7%, 47.8%, and 14.8%, respectively) was significantly (P < 0.05) lower. Atrophic gastritis was milder in both reflux groups than in the non-reflux group. The degree of gastritis was also milder in the severe reflux group than in the mild reflux group. The esophageal sphincter pressure was significantly (P < 0.05) lower in the reflux groups than in the non-reflux group, and the amplitude of primary peristalsis was significantly (P < 0.05) lower in the severe reflux group than in the non-reflux group. There were no significant differences between reflux patients with and without Helicobacter pylori infection in the parameters of esophageal manometry. These data imply that a low prevalence of Helicobacter pylori infection may result in a milder grade of atrophic gastritis, and consequently, exacerbate reflux esophagitis.

Analysis of Variance↗
PubMed1999

Postoperative oblique sagittal MR imaging of microvascular decompression for hemifacial spasm.

Pre-operative and postoperative oblique sagittal gradient-echo magnetic resonance (MR) imaging was used to evaluate micro-vascular decompression of the facial nerves in 26 patients with hemifacial spasm. The pre-operative MR images were divided into two groups as follows: 22 images in Group I, clear imaging of a high-intensity line and/or spot at the root exit zone (REZ) of the facial nerve; and 4 in Group II, and unreliable image around the REZ. Surgery found that the causative vessel was the vertebral artery (VA) in 9 cases and the anterior inferior cerebellar artery (AICA) or the posterior inferior cerebellar artery (PICA) in 13 cases in Group I, and the AICA or the PICA in the 4 cases in Group II. Postoperative MR imaging showed clear decompression as the high-intensity line and/or spot completely separated from the REZ by a low- and/or iso- intensity area in 9 cases of VA compression repositioned to the petrous dura matter, in 11 cases of PICA or AICA compression treated by shredded Teflon pledgets in Group I and in 3 cases in Group II. Postoperative MR imaging showed an incomplete separation of any high-intensity line and/or spot in the REZ in 2 cases of PICA or AICA compression in Group I and in one in Group II. The outcome was excellent in 22 of 23 cases with clear decompression, and in 1 of 3 cases of unclear decompression. Hemifacial spasm persisted in 3 cases. Oblique sagittal gradient-echo MR imaging is a useful method for postoperative follow-up which can demonstrate changes around the REZ of the facial nerve if hemifacial spasm recurs.

Arteries↗
PubMed1999

Role of endogenous cathepsin D-like and chymotrypsin-like proteolysis in human epidermal desquamation.

Even though the skin surface is acidic (about pH 5), most in vitro studies on desquamation have been performed at alkaline pH. We demonstrate that the standard in vitro model system, which achieves squame shedding upon incubation of plantar stratum corneum for 1 day in an alkaline buffer that must include a chelating agent, can be extended to a more realistic model in which the incubation is for 4 days, at varying pHs from 5 to 8, without exogenous chelators. Desmoglein I from stratum corneum was degraded by the squames shed at pH 5 as well as at pH 8. Squame shedding was inhibited to varying extents by the addition of proteinase inhibitors, whose specificity suggested that the crucial enzymatic activity at pH 8 was a chymotrypsin-like serine proteinase, while a similar activity at pH 5 was accompanied by an aspartic proteinase activity of comparable strength. Four degradation peaks were observed when the insulin B chain was reacted with shed squames at pH 5. Two of these peptides were suppressed by the addition of phenylmethylsulphonyl fluoride, the other two by pepstatin A; chymostatin inhibited all four, but E-64 and leupeptin showed no effect. The implied specificity was confirmed by reacting the insulin (without squames) with the standard enzymes human liver cathepsin D and pancreatic chymotrypsin, reproducing the expected degradation products. These results suggest that epidermal desquamation at acidic pH requires two proteolytic activities, one of which is an analogue of chymotrypsin and the other of cathepsin D. Endogenous proteinases corresponding to these activities have been previously identified, namely the stratum corneum chymotryptic enzyme and the mature active form of cathepsin D.

Blotting, Western↗
PubMed1999

Oculomotor nerve palsy after surgery for upper basilar artery aneurysms.

OBJECTIVE: The goals of this study were to evaluate the relationship between postoperative oculomotor nerve palsy and other clinical factors and to improve preoperative estimations of the risk. Such an evaluation has not been previously described in the literature. METHODS: Patient records for 77 basilar tip aneurysm cases and 28 basilar superior cerebellar artery aneurysm cases treated between 1981 and 1997 were reviewed. Clinical and radiological parameters were separately analyzed using the chi2 test, and then multiple-regression analysis was used. RESULTS: Postoperative oculomotor palsy occurred in 25 (32%) patients with basilar tip aneurysms and 11 (39%) patients with basilar superior cerebellar artery aneurysms, in addition to 2 patients with basilar tip aneurysms and 3 patients with basilar superior cerebellar artery aneurysms who exhibited oculomotor palsy before surgery. For both type of aneurysms, the size and direction of the aneurysms were closely related to oculomotor nerve palsy. The complication also tended to occur in early surgery cases, in younger patients, and in patients of poor-clinical grade status. CONCLUSION: In this study, some clinical and radiological factors were found to be associated with postoperative oculomotor nerve palsy.

Basilar Artery↗
PubMed1999

Treatment of intradural paraclinoidal aneurysms.

Intradural paraclinoidal aneurysm still presents conceptual confusion and technical surgical problems. The clinical features of 68 consecutive patients with paraclinoidal aneurysms were analyzed. The pterional approach was used in all patients. Subarachnoid hemorrhage (SAH) occurred in 37 patients from the paraclinoidal aneurysm and in 10 patients from another associated aneurysm. Thirty-four of the 37 ruptured paraclinoidal aneurysms were clipped, two blister-like aneurysms required trapping, and one blister-like aneurysm was coated. Thirteen of the 31 unruptured paraclinoidal aneurysms, consisting of 10 with ruptured associated aneurysm, four symptomatic, and 17 incidental, were clipped and 18 were coated. Favorable outcomes were obtained in 38 of 47 patients with SAH and 17 of 21 patients without SAH. Nine unfavorable outcomes in SAH patients were caused by primary brain damage (5), vasospasm (2), cerebral infarction after trapping (1), and pneumonia (1). All four unfavorable outcomes in non-SAH patients were due to surgical procedures for giant aneurysms or associated basilar artery aneurysm. Removal of the anterior clinoid process was performed to secure the proximal neck in 15 patients with large or giant aneurysms. Multiple clips with or without fenestrated clips were required in all giant aneurysms, and exposure of the cervical internal carotid artery (ICA) in 17 giant or large aneurysms. Fenestrated clips were also useful for one small aneurysm projecting posteriorly. A favorable outcome was achieved in 17 of 19 patients undergoing coating. Coating without clipping might be better for some blister-like ICA aneurysms, even if ruptured. Paraclinoidal aneurysms can be clipped with favorable results using these techniques except for giant aneurysms and associated basilar artery aneurysm.

Adult↗
PubMed1998

Associative learning of visual and vestibular stimuli in Lymnaea.

A conditioned withdrawal response was characterized in the pond snail Lymnaea stagnalis. Using light as the conditioned stimulus and high-speed orbital rotation as the unconditioned stimulus, experimental animals were trained with 30 paired presentations of light and orbital rotation per day for 3 days. After training, all experimental animals responded to light with a withdrawal response, the conditioned response. Control animals exposed to the same number of explicitly unpaired presentations of light and orbital rotation, light alone, or no stimulation did not respond to light. Thirty paired presentations per day for 2 days produced less than optimal acquisition of the conditioned withdrawal response. Neither 45 paired presentations per day for 2 days nor 90 paired presentations for 1 day resulted in complete acquisition of the conditioned withdrawal response. The conditioned withdrawal response observed following 30 paired presentations per day for 3 to 5 days persisted to Day 10, regardless of the number of training days. As a measure of savings, reacquisition of the conditioned response after extinction was investigated. After the conditioned withdrawal response was extinguished, only 2 to 5 paired presentations of light and orbital rotation were required for reacquisition of the conditioned response for most animals. This study further establishes Lymnaea as an animal model of basic associative learning.

Animals↗
PubMed1998

Isoforms of cathepsin D and human epidermal differentiation.

Cathepsin D is an ubiquitously expressed lysosomal aspartic proteinase, with well-determined structural and chemical properties but a less clearly defined biological role. In stratified epithelia, the chronology of cathepsin D activation and degradation can be connected with stages of cellular differentiation. We partially purified cathepsin D from human epidermis and from separated stratum corneum by standard biochemical procedures, monitored by SDS-PAGE and Western blotting, and verified its identity as to molecular mass, pH optimum, N-terminal sequencing, reactivity with the specific antibody, inhibition by pepstatin A, and specific enzyme activity. It had hemoglobin-degrading activity over the acid range, with maximum at pH 3. It also degraded bovine serum albumin, human keratins, and stratum corneum extracts at pH 4. We discerned all three isoforms of human cathepsin D (the 52 kDa proenzyme and the active forms at 48 kDa and 33 kDa) in the epidermis; both active forms were also seen in the stratum corneum, but the proenzyme was not. Gene expression of cathepsin D in epidermal keratinocytes resembled that of suprabasal structural proteins (involucrin, keratin K10, transglutaminase) in its response to the calcium switch. An antibody to the 33 kda isoform immunolocalized to the granular layer and the stratum corneum (whereas antibodies to the 48 kDa isoform have been reported to stain mainly the upper spinous and granular layers). A plausible hypothesis to harmonize these results is that cathepsin D is first expressed as the proenzyme in the upper spinous layer, is activated in the lysosomes in the granular layer to the 48 kDa form, and is degraded to the 33 kDa form in the transition zone between the granular layer and the stratum corneum. As the stratum corneum is an acid environment, with an ambient pH of approximately 4.5, cathepsin D is available and suited to contribute to desquamation.

Amino Acid Sequence↗
PubMed1998

Differentiation and cathepsin D expression in human oral tumors.

OBJECTIVES/HYPOTHESIS: This study aimed to ascertain whether cathepsin D expression could be related to the stage of differentiation of oral tumors. STUDY DESIGN: Human oral biopsies of 10 squamous cell carcinomas and of the corresponding perilesional normal tissues were used. The tumors had all been clinically graded as advanced stage but nonmetastatic; five were classified histopathologically as poorly differentiated. METHODS: The gene expression of cathepsin D and keratin K13 in the biopsies was measured by reverse transcription polymerase chain reaction. Ratios of tumor-to-control readings helped compensate for sample variability. RESULTS: Keratin K13, as a suprabasal cell marker, tended to confirm the histological grading of the tumors (but was not otherwise useful in distinguishing tumors from normal tissue). Substantial overexpression of cathepsin D was found in the poorly differentiated tumors. CONCLUSIONS: Cathepsin D overexpression is considered a prognostic indicator of metastasis. In this sample, it was also associated with dedifferentiation. Cathepsin D might serve as a valuable gauge in clinical exploration of the connection between dedifferentiation and metastasis.

Adult↗
PubMed1998

Computed tomography characteristics suggestive of spontaneous resolution of chronic subdural hematoma.

The clinical and radiological characteristics of self-resolving hematoma were assessed retrospectively in a series of patients with chronic subdural hematomas (SDHs) treated over a recent 6-year period in a local hospital. Spontaneous resolution was observed in five of 27 hematomas occurring in four of 23 patients. Clinical and radiological findings of the four cases were compared to those of the remaining 19 cases. All spontaneously resolving SDHs were asymptomatic or only caused mild transient headache, and disappeared within 4 to 9 months after head injury. All spontaneously resolving SDHs were located in the frontal region, and maximum thickness and midline displacement were less than those in the other 19 patients who were symptomatic and underwent surgery. Computed tomography demonstrated a low density line between the hematoma and the cerebral cortex, indicative of remaining cerebrospinal fluid space in four of five hematomas. Spontaneously resolving SDH is more frequent than formerly expected. Asymptomatic SDHs localized in the frontal region with small mass signs can be expected to disappear spontaneously without deterioration.

Aged↗
PubMed1998

Technical points to improve surgical results in cases with basilar tip aneurysms.

Surgical results in 82 cases with aneurysm (61 ruptured and 21 unruptured) of the bifurcation of the basilar artery were analyzed and the causes of unfavorable outcome and its measures were discussed. Operation was performed in grade I, II, III, or IV of the Hunt and Kosnik's classification for the patients with ruptured aneurysm. Both in ruptured and unruptured cases, patient's age was not considered. As it turned out, 10 elderly (70 years old or older) cases (8 ruptured and 2 unruptured) were included in this study. Unilateral pterional approach was adopted for all but one case, and temporary clip and/or division of the hypoplastic posterior communicating artery was actively used. Surgery was completed with clipping of the aneurysm in all but six cases and overall surgical result consists of 70% of favorable outcomes. The main causes of unfavorable outcome were surgical procedures and primary brain damage due to subarachnoid hemorrhage. And the factors influenced to increase surgical technical damage to the brain were the patient's age, size of the aneurysm, and/or height of the neck from biclinoids line. The outcome of the higher grade (grade III or IV) in elderly cases was miserable, whereas it was not different from anterior circulation aneurysms in younger cases. From the result we concluded that the surgical indication for elderly cases should be limited in cases with lower grade (grade I or II) without large and/or high-positioned aneurysm. To obtain further improvement of the surgical result in younger cases, additional surgical techniques have to be considered to avoid the injury of perforating arteries from P1 and to reduce the pressure of the brain retraction which are the most important hazards for aneurysm surgery in this area.

Aged↗
PubMed1997

Music alexia in a patient with mild pure alexia: disturbed visual perception of nonverbal meaningful figures.

A 26-year-old female pianist suffered from an intracerebral hematoma caused by an arteriovenous malformation of the left occipital parasplenial region, which was operated on seven months after the onset. Incomplete right hemianopsia, mild pure alexia, and partially disturbed naming of visual objects persisted several months after the removal of the malformation. Evaluation of musical ability one and three months after surgery showed that her auditory recognition of music was intact. She could sing and play melodies already learned and could dictate well the notes after hearing tones. However, she had difficulty in reading music, especially the pitch of notes, even for simple sequences of 4 notes. In contrast, her rhythm reading was fairly good. Her visual recognition of other symbolic figures like road signs was also markedly impaired. These results suggest that her visual recognition of written music as well as of other symbolic figures underwent a preliminary verbal decoding in the left hemisphere and that pitch reading was more dependent on verbal processing than rhythm reading.

Adult↗
PubMed1997

Molecular genetic analysis of HLA class II alleles in Japanese patients with melanoma.

Distribution of HLA-DQA, -DQB and -DPB alleles in ninety-six Japanese patients with melanoma was analyzed using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, and the association between clinical parameters and the presence of certain HLA class II alleles investigated. The frequency of HLA-DQB1*0302 was increased, while those of DQA1*0101(04), -DQA1*0401 and DRB1*0802 were decreased in melanoma patients compared with controls. Moreover, the frequency of HLA-DQA1*0103 in patients with acral lentiginous melanoma was increased compared with controls. However, none of these HLA class II alleles showed significant positive or negative associations after correction of the P value. In addition, there was no correlation between these antigens and clinical parameters. These results indicate that HLA class II alleles may not contribute to a strong susceptibility to melanoma in the Japanese.

Adult↗
PubMed1997

Effects of ethyl alpha-D-glucoside on skin barrier disruption.

Daily treatments of skin in hairless mice with concentrates of rice wine, Japanese traditional alcohol, lowered transepidermal water loss levels compared to the controls on the 3rd day after ultraviolet B (UVB) irradiation. These findings indicate that the concentrates of rice wine suppress the murine skin barrier disruption caused by UVB. Ethyl alpha-D-glucoside (alpha-ethylglucoside), one of the peculiar components in rice wine, showed the same effect, whereas beta-ethylglucoside had no effect. In order to clarify the functions of alpha-ethylglucoside on murine skin, we examined the effects of this compound on the expression of some phenotypes in human keratinocytes in vitro. As a result, alpha-ethylglucoside as well as beta-ethylglucoside enhanced cell proliferation weakly, and the formation of cornified envelopes and differentiated type keratin (K1) in keratinocytes was accelerated by alpha-ethylglucoside but not by beta-ethylglucoside. From the results, we conclude that alpha-ethylglucoside enhanced the differentiation of keratinocytes, which might be related to reduced barrier disruption by UVB.

Alcoholic Beverages↗
PubMed1997

Further classification of dysmotility-like dyspepsia by interdigestive gastroduodenal manometry and plasma motilin level.

OBJECTIVE: To investigate interdigestive gastroduodenal motility with an infused catheter and measure plasma motilin levels in eight normal individuals and 18 patients with dysmotility-like dyspepsia. METHODS AND RESULTS: All normal individuals had normal gastroduodenal interdigestive migrating complexes. Patients with dysmotility-like dyspepsia were classified into three subgroups on the basis of gastric antral motility: 1) seven patients with normal interdigestive migrating complexes, 2) five patients without interdigestive migrating complexes and with gastric phase II predominant over phase I, and 3) six patients without interdigestive migrating complexes and with phase I predominance. The maximum and mean plasma motilin levels were significantly different in normal individuals from those in subgroup 3 (Kruskal-Wallis test, p < 0.05). CONCLUSIONS: Dysmotility-like dyspepsia appears to be a heterogeneous condition. Abnormal motilin secretion may cause dysmotility in subgroup 3, but dyspepsia in subgroup 1 and the absence of interdigestive migrating complexes in subgroup 2 could not be explained only on this basis.

Adult↗
PubMed1996

Retropharyngeal abscess after radiation therapy and cis-platinum, 5-fluorouracil treatment for nasopharyngeal carcinoma with collagen disease: report of two patients and a review of the literature.

Collagen disease are frequently associated with malignant tumors. Recently, radiotherapy combined with chemotherapy has been recommended for improving the efficacy of treatment for nasopharyngeal carcinoma. Two patients with nasopharyngeal carcinoma complicated by collagen diseases (dermatomyositis in one, and Sjögren's syndrome with mixed connective tissue disease in the other) were given radiotherapy combined with chemotherapy consisting of cis-platinum and 5-fluorouracil. Following this combination therapy, both patients developed retropharyngeal abscess and ulceration of the mucosal membrane on the posterior wall of the oropharynx; there was no tumor cell involvement. Because these injuries were more severe than would have been expected from radiotherapy alone, it is recommended that special attention be paid to combination therapy in patients with nasopharyngeal carcinoma complicated by collagen disease.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

HLA class I antigens in Japanese patients with melanoma.

In this study, we analyzed the frequencies of human leukocyte antigen (HLA) class I alleles in 110 Japanese patients with melanoma using serological methods, and compared such frequencies with clinical parameters. As expected, frequencies of HLA allele distribution in patients with melanoma reflected the frequencies observed in the normal Japanese population. Because these are different from populations belonging to other races (e.g., white), it followed that the HLA allele distribution in melanoma patients varies among different races. This differences may have significant implications for T-cell-mediated, HLA-restricted therapeutic modalities. No significant associations between HLA and clinical parameters were noted in this study. This report may help design future clinical trials involving therapeutic approaches based on HLA-restricted mechanisms.

Adult↗