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Biomedical subjects

Y Yashima

Publications and source records attributed to Y Yashima.

At least 19 recordsLinked to original sources
PubMed1992

Melanocyte chemotactic factor produced by skin metastases of a breast carcinoma.

A 65-year-old woman underwent right modified radical mastectomy for a malignant lesion which had developed just below the right nipple. Two years after the operation, skin lesions composed of dark brown to black, pigmented, papular lesions developed in the precordia. A biopsy revealed this to be a cutaneous metastasis of the previous breast carcinoma. However numerous pigment blockade melanocytes were also found in the tumor nests, located in and/or beneath the epidermis. Although a black-colored breast carcinoma has been reported, the presence of pigment blockade melanocytes was not determined. Culture of the tumor nest recovered a population of melanocytes as well as the carcinoma cells. Boyden chamber analysis revealed the presence of a chemotactic factor for melanocytes in the culture medium. This seems to be the first documentation of melanocyte incorporation in breast carcinoma tissue.

Adenocarcinoma↗
PubMed1992

Serial changes of SPECT in periodic synchronous discharges in a case with Creutzfeldt-Jakob disease.

We conducted serial EEG and SPECT studies on one female with Creutzfeldt-Jakob disease (CJD). In an analysis of EEG, a periodic synchronous discharge (PSD) was observed in the middle of the third stage (terminal stage) of Bernoulli's classification. The frequency of PSD was the highest at the beginning of the third stage, followed by a gradual decrease and disappeared at the end of the third stage. In the middle of the third stage, SPECT disclosed blood flow differences between the cerebrum and other regions (the cerebellum and the brainstem), while no such difference was observed by SPECT at the end of the third stage. It was suggested that the appearance of PSD requires the presence of a pathological change in the cerebrum precedent to other regions.

Aged↗
PubMed1992

Differing cell surface distribution of human leukocyte antigen-DR molecules on epidermal Langerhans cells and eccrine duct cells.

Scanning electron microscopy (SEM) with immunogold labeling was employed to observe the undersurface of the human epidermis after it was split from dermal connective tissue, in an attempt to localize the molecules actually expressed on cell/tissue surfaces. We found that human leukocyte antigen-DR (HLA-DR) molecules were expressed on the surfaces of eccrine duct cells as well as those of epidermal Langerhans cells (LC) in normal skin. HLA-DR molecules, visualized by the deposition of gold particles, were distributed evenly on the LC surface but were present only along the interdigitating borders of the individual duct cells, thus producing a meshwork pattern on the duct surface. Transmission electron microscopy confirmed that the gold particles labeling cell surface HLA-DR molecules were seen only on the portions of duct cell membranes the interdigitated with neighboring duct cells. These findings suggest that the function of HLA-DR molecules may vary with their location and distribution. On the LC surface, the evenly distributed molecules seem to be well suited for promoting "accessory cell" functions. On duct cell surfaces, the HLA-DR molecules present along the intercellular spaces may be involved in trapping various peptide antigens that pass into the sweat gland filtrate and then are reabsorbed by the excretory duct, since these molecules have a highly permissive capacity for binding various peptides.

Epidermal Cells↗
PubMed1991

Neutrophil as a mediator of ischemic edema formation in the brain.

We investigated the contribution of neutrophils to brain edema formation using a transient focal ischemia model in rats. Rats were given anti-neutrophil monoclonal antibody (RP3) intraperitoneally to deplete circulating neutrophils. In RP3-treated rats, ischemic brain edema formation 1 day after reperfusion was significantly decreased compared to that of saline-treated control rats. We speculate that chemical mediators released by infiltrating neutrophils alter vascular permeability and play an important role in post-ischemic brain edema formation.

Animals↗
PubMed1991

Laser-induced photoacoustic injury of skin: effect of inertial confinement.

Argon-fluoride (ArF) excimer laser-induced acoustic injury was confirmed by ablating the stratum corneum (s.c.) inertially confined by water in vivo. Hairless rats were irradiated through a quartz chamber with flowing distilled water or air and a 2.5 mm aperture. The laser was adjusted to deliver 150 mJ/cm2 at the skin surface for both conditions. Partial and complete ablation of the s.c. was achieved with 12 and 24 pulses, respectively. Immediate damage was assessed by the transmission electron microscopy. Partial ablation of the s.c. through air produced no damage, whereas partial ablation through water damaged skin to a mean depth of 114.5 +/- 8.8 microns (+/- SD). Full thickness ablation of the s.c. through air and water produced damage zones measuring 192.2 +/- 16.2 and 293.0 +/- 71.6 microns, respectively (P less than 0.05). The increased depth of damage in the presence of inertial confinement provided by the layer of water strongly supports a photoacoustic mechanism of damage. The damage induced by partial ablation of the s.c. provides evidence that photochemical injury is not a significant factor in the damage at a depth because the retained s.c. acts as a partial barrier to diffusion of photochemical products. Combined with our previous studies, these experiments demonstrate that pressure transients are responsible for the deep damage seen with 193 nm ablation and that photoacoustic effects must be considered when using short-pulse, high-peak power lasers.

Animals↗
PubMed1991

Lateral asymmetry of eye movements in temporal lobe epileptic patients with unilateral foci.

Eye movements in response to visual stimuli (Benton Visual Retention Test) were examined in 22 temporal lobe epileptics (TLEs), 10 primary generalized epileptics (PGEs), and 20 normal controls. In the normal controls, the percent fixation time on the left peripheral figure was higher than that on the right peripheral figure, a tendency also found in the PGEs. In TLEs with right-sided foci, the percent fixation time on the left peripheral figure was higher than that on the right peripheral figure, the direction of asymmetry found in the normal controls and PGEs. However, when calculated as laterality indices (the degree of asymmetry) TLEs with right-sided foci were significantly more negative than those of both the normal controls and PGEs. In TLEs with left sided foci, the percent fixation time on the right peripheral figure tended to be higher than that on the left peripheral figure, an asymmetry which differed significantly from the normal controls, PGEs and the TLEs with right-sided foci. The results here showed that TLEs with unilateral foci had distinct eye movements which varied with the laterality of the lesion in the direction of functional overactivation of the epileptogenic hemisphere.

Epilepsy, Generalized↗
PubMed1991

Three cases of anomic aphasia after lesions in and/or around the basal ganglia.

The present paper reports 3 cases of aphasia with small lesions in the region of the basal ganglia to discuss whether neostrial dysfunction can cause aphasic symptoms. The Standard Language Tests of Aphasia (SLTA) was used to assess the type and degree of aphasia. Two patients with infarction either in the left putamen or in the head of the left caudate nucleus showed severe disturbance only in recalling words, especially nouns. The other patient showed the same symptom, in addition to writing disturbance that developed shortly after surgical extirpation of an arteriovenous malformation (AVM) in the left caudate nuclei. The symptoms common to the 3 patients corresponded well to the "anomic aphasia" proposed by Benson. The aphasic symptoms disappeared completely or largely within several months. This easy reversibility suggests that the aphasic disorder in the three patients was caused by damage not to the basal ganglia themselves, but to the affecting axons passing through or by the nuclei.

Aged↗
PubMed1990

Cell selectivity to laser-induced photoacoustic injury of skin.

Cell selectivity to photoacoustic injury induced by argon-fluoride excimer laser (193 nm) was studied. Rats were irradiated through air or water and a 2.5 mm aperture. The laser was adjusted to deliver 150 mJ/cm2 at the skin surface with 12 and 24 pulses. Immediate damage was assessed by transmission electron microscopy. Cell selectivity was observed in dermis and epidermis. Fibroblasts showed alteration of nuclear chromatin and cytoplasmic organelles, while some of the migratory cells adjacent to fibroblasts did not. Similar difference of damage was observed between keratinocytes and Langerhans cells in epidermis. Considering the relationship between cells and their microenvironment in tissue, this selectivity may be due to the difference of acoustical coupling of propagation of acoustic waves rather than to differential sensitivity of the cells to damage.

Animals↗
PubMed1987

Higher density of 125I-neuropeptide Y receptors in the area postrema of SHR.

125I-Neuropeptide Y (125I-NPY) binding capacities were quantitated in the areas postrema of young (5 weeks) and adult (20 week SHR and compared with age-matched WKY rats using autoradiography. The maximum binding capacity (Bmax) was significantly higher in the area postrema of adult SHR, while no difference was seen at the age of 5 weeks. Our result supports the idea of a functional role for NPY receptors in the central control of blood pressure. NPY receptors in the area postrema may be involved in the perception of circulating NPY resulting in the alteration of the neuronal activity of the nucleus tractus solitarii.

Age Factors↗
PubMed1987

The application of DSM-III diagnostic criteria to school refusal.

The DSM-III diagnostic criteria were applied to school refusal cases, and the possibility of a subclassification of school refusal through the DSM-III was studied. The subjects were 50 cases diagnosed as school refusal following the criteria defined by Sumi and Tatara. As for the Axis I diagnoses, the subjects fell under the separation anxiety disorder (7 cases), avoidance disorder (13 cases), overanxious disorder (8 cases), identity disorder (5 cases), adjustment disorder (11 cases) and others. On Axis II, no case was diagnosed as having the personality disorder, but 14 cases showed pathological personality traits. On Axis III, nine cases showed some physical disorders or conditions. Among the five major diagnostic groups, there were some definite differences concerning the onset age, clinical course, psychosocial stress, response to therapy and prognosis of disorders. These results suggest the availability of a subclassification of school refusal by means of the DSM-III criteria.

Adolescent↗
PubMed1987

Clinical features of autistic children with setback course in their infancy.

This study examines the incidence rate of setback in 80 autistic children, the correlation between the type of onset and clinical features, developmental level and prognosis based on an originally developed questionnaire. Moreover, this study seeks to investigate the possibility that infantile autism might be classified into subgroups by the type of onset. 1) The acquired (including questionably acquired) group consisted of 39 cases (49%), while the natal group was made up of 41 cases (51%). 2) The age when the setback occurred was 21-22 months in the acquired group. 3) Precipitating psychological events were observed in 22 cases (56%) of the acquired group. 4) The mental developmental level including speech and socialbility function at 5 years of age was significantly lower in the acquired group than in the natal group. 5) The acquired group showed severe behavioral disorders such as "stereotypic behavior," "extremely hyperkinetic behavior" and "self-abusive behavior" compared with the natal group. 6) The adaptive levels at schools or institutions were lower in the acquired group than in the natal group. 7) There was a higher incidence of epileptic seizures or febrile convulsions in the acquired group than in the natal group. Moreover, there was a higher incidence of severe perinatal abnormalities in the acquired group. 8) The above-mentioned results suggest that infantile autism might be classified into two subgroups, acquired and natal groups, based on the type of onset, and also suggest that some types of brain dysfunctions are more severe in the acquired group than in the natal group.

Age Factors↗
PubMed1987

A new concept of basal cell epitheliomas based on the three-dimensional growth pattern of the superficial multicentric type.

Little is known about the growth characteristics of basal cell epitheliomas (BCEs), largely because of the difficulty in studying these tumors, both in situ and in vitro. In this study, the authors report that a scanning electron microscopic examination of 2 cases of superficial BCEs reveals that the tumor proliferates centrifugally as a monolayer beneath the epidermis as well as over the surfaces of hair follicles, while eroding and replacing the original basal architecture. Behind the leading edge of this monolayer, the cells split away from the epidermis to form a round border resembling a carpet being rolled up. This border then develops into a mass lesion, which represents the tumor cell foci seen in routine paraffin sections. These findings have led the authors to propose a fundamentally different explanation for the pathogenesis of these tumors: BCEs are conditioned neoplasms that require contact with the epidermal or hair follicular epithelium in order to grow. This hypothesis could explain the behavior of BCEs as well as the clinical and pathologic varieties observed in clinical practice.

Aged↗
PubMed1987

[The groping phenomena in a case of Alzheimer type dementia].

We reported a case of senile dementia, Alzheimer type, with groping in response to a visual stimulus ("visual groping"). T.S. was a right-handed woman, 69 years old. In the beginning she displayed "visual groping" of the right hand, besides aphasia, lowered registration and Casteigne's "Motor neglect" of the right upper extremity. As the disease progressed, "visual groping" of the left hand developed, followed by "forced grasping" of the left hand. When the patient was 62 years old, she first showed decreased volition and lowered registration. Later poor finger movement and lessened speech were marked. At the age of 69, she was admitted to our hospital with aphasia and reduced registration. The patient showed preservation in naming and drawing tests. She also displayed a "visual groping" phenomenon of the right hand. This phenomenon was revealed when an examiner displayed something about 50 cm in front of the patient, and then she extended the upper extremity gropingly. We considered this phenomenon as "groping in response to a visual stimulus" of Denny-Brown. At the same time, the motor or praxic disorder of this patient consisted of paucity of movement. When she was told to imitate, her right upper extremity was hardly utilized, although later movements could be realized by her practice. When she was told to pour water from one glass into another, she used her left hand, although she used her right hand for spontaneous actions. So we considered this dyspraxia as a motor neglect of Casteigne.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

Quantitative autoradiographic localization of neuropeptide Y receptors in the rat lower brainstem.

Using quantitative autoradiography, we have characterized the binding of 125I-Bolton-Hunter coupled neuropeptide Y ([125I]NPY) and observed the localization of 125I-NPY receptors in the rat lower brainstem. [125I]NPY bound to the receptors in a specific, saturable and reversible manner with high affinity. The binding was blocked only by unlabeled NPY but not by NPY-related peptides i.e. peptide YY, pancreatic polypeptide (avian and human), nor by neurotensin. [125I]NPY receptors were revealed to be coupled to the guanosine triphosphate (GTP)-binding protein. Regional distribution study showed that [125I]NPY has a distinctive pattern of distribution in the rat lower brainstem, being particularly concentrated in the area postrema and the medial subnucleus of the nucleus tractus solitarii. These results suggest that such NPY receptors have an important role in cardiovascular regulation.

Animals↗
PubMed1984

Computed tomography of the brain in children with early infantile autism.

In order to examine the cranial CT of autistic children and investigate the etiological significance of CT scan findings, the CT of the brain was surveyed in 24 children with early infantile autism (3 to 17 years with a mean age of 7.6), and 179 children with the normal CT despite their medical histories such as headaches or febrile convulsions. According to their ages, the autistic and normal children were divided into the following three groups: Group I (age ranging from 3 to 5), Group II (age: 6 to 9) and Group III (age: 10 to 17). There was no significant difference between the bifrontal CVI of the autistic children and that of the normal children. However, in Group III, the bifrontal CVI of the autistic children was significantly higher than that of the normal children. There was no significant difference between the bicaudate CVI of the autistic children and that of the normal children. However, in Groups I and II, the bicaudate CVI of the autistic children was significantly lower than that of the normal children. The maximum widths of the third ventricle showed no significant difference between the autistic and normal children. However, in Groups II and III, those of the autistic children were wider than those of the normal children. In the autistic children, as the age increases, the difference becomes significantly wider. A positive correlation was observed between the width of the third ventricle and ages of the autistic children. An examination of the right-left ratio of maximum transverse diameter of the brain showed that there was no significant difference between the autistic and normal children. The above-mentioned results (1)-4)) might suggest a progressive disorder of the brain structure surrounding the third ventricle or lateral ventricles in the autistic children.

Adolescent↗