Search PubMed⌕ Search

Biomedical subjects

Y Seki

Publications and source records attributed to Y Seki.

At least 181 records · Page 10Linked to original sources
PubMed1987

[Causative factors of recurrence of chronic subdural hematoma].

Burr hole opening and irrigation of hematoma is now a widespread simple technique for the treatment of chronic subdural hematoma (CSH). However, recurrence of hematoma has been sometimes experienced after initial treatment. The purpose of this report is to analyze the causative factors in recurrence of the hematoma after the burr hole opening and irrigation. Out of 68 adult cases of CSH treated by burr hole opening and irrigation technique at Toranomon Hospital during the past nine years, 11 cases (16.2%) showed recurrence of symptoms due to reaccumulation of hematoma after the 1st operation. They were compared with non-recurrence cases from the viewpoint of clinical signs, symptoms and course and serial CT findings. But there was no statistically significant difference between them. The causative factors of recurrence of CSH were analyzed and divided into four categories. Type 1 (3 cases): specific promoting factors--Primary intracranial hypotension (2 cases) and anticoagulant therapy (1 case). Type 2 (1 cases): immature timing of operation. Type 3 (4 cases): other causes probably due to operative procedure--Insufficient postoperative external drainage. Type 4 (3 cases): unknown cause. Several authors have reported causative factors of recurrence of CSH so far, but they are still controversial. An additive treatment in the cases involving specific factors, and planning the timing and some procedures of operation are proposed in order to avoid recurrence of CSH.

Adult↗
PubMed1987

[Trigeminal somatosensory evoked potentials: II. Some clinical experiences].

Compared to other somatosensory evoked potentials (SEP), little information has been published so far on trigeminal somatosensory evoked potentials (TSEP) in the various kind of disorders. This may be due to few recording technique suitable for clinical practice. We previously reported a new recording method and showed the normal pattern of TSEP. The purpose of this report is to examine its reliability for clinical use. Sixty patients, with either a complaint of facial numbness or an organic lesion supposed to involve facial sensory pathway, were investigated. Their age ranged from 13 to 74 years old (mean 47.0). They consisted of 34 organic lesions (30 brain tumors and 4 cerebrovascular diseases) and 26 non-organic lesions (16 hemifacial spasms, 6 trigeminal neuralgias and other miscellaneous disorders). TSEP was recorded by the stimulation of the half of the contralateral upper or lower lip with the clip-shaped electrode. C'5 or C'6 (midpoint between Cz and the external auditory porus) was used as an active electrode and Fz as a reference. Two hundred or four hundred responses were averaged by a Nicolet Pathfinder II. All recordings were repeated at least twice to confirm the reproducibility. (1) Among 21 patients with a complaint of facial numbness except for neuralgia, the abnormality rate of TSEP was significantly different (p less than 0.02) between organic and non-organic lesions. The former was 87.5% (14 out of 16 cases) and the latter was 20% (1 out of 5 cases).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

[Trigeminal somatosensory evoked potentials: I. Recording technic and normal responses].

The general wave form and time course of somatosensory evoked potentials (SEP) to the stimulation of upper and lower extremities has been well known in recent years. However, only a little information has been published so far on SEP to the trigeminal nerve stimulation (TSEP), and at present there is not always common methodology available in clinical practice. These may be due to the technical problems from the close proximity of stimulating and recording electrodes. The purpose of this report is to attempt to solve some of the difficulties of the procedure, as well as to show the morphology and time course of TSEP in a group of normal healthy subjects. Twenty healthy volunteers were investigated. Their age ranged from 22 to 61 years old (mean 29.3). Clip shaped silver-balled stimulating electrodes with 2 mm contact surface and interelectrode distance of 10 mm were applied to the inner surface of the lips. They were held in place without any support, thus minimizing muscle activity of the subject. Each half of the upper and lower lip was then stimulated in turn by an electrical rectangular pulse of 3 or 4 times sensory threshold (usually 1.5-2.0 mA) and 0.2 msec duration, at a rate of 2.3 per second. TSEP was recorded contralaterally from C'5 or C'6 (midpoint between Cz and external auditory porus). Fz was used as a reference. Four hundred responses were averaged by a Nicolet Pathfinder II, which also generated stimulation pulses. Stimulus polarity was reversed after each 100 stimuli to eliminate stimulus artifact. Analysis time was set to 50 msec.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Tunable dye laser (577 nm) treatment of port wine stains.

Despite steady improvement in the laser treatment of port wine stains (PWS), hypertrophic scarring remains a serious side-effect in approximately 10% of patients. The tunable dye laser (577 nm) has been shown to cause selective vascular destruction in normal and PWS skin. We have treated ten patients using a tunable dye laser (577 nm, 300 mu sec) resulting in clearing of the PWS without any evidence of hypertrophic scarring. Treatment requires no anesthesia or wound care, and there were no postoperative infections.

Adolescent↗
PubMed1986

Lectin-binding sites in eccrine sweat gland tumours.

Lectin-binding sites in sections of formalin-fixed, paraffin-embedded eccrine sweat gland tumours were investigated using fluorescein isothiocyanate (FITC) conjugated peanut agglutinin (PNA), FITC conjugated Ricinus communis 1 agglutinin (RCA-1) and FITC conjugated wheat germ agglutinin (WGA). In 22 benign eccrine sweat gland tumours, lectin-binding sites were noted primarily on the cell surface, and in the secretions. In five malignant sweat gland tumours, all showed cytoplasmic lectin-binding sites in variable proportions of malignant cells in addition to cell surface staining. These results indicate that cytoplasmic lectin-binding sites may be a useful marker of neoplastic transformation of eccrine sweat gland tumours.

Cell Membrane↗
PubMed1986

Histologic responses of port-wine stains treated by argon, carbon dioxide, and tunable dye lasers. A preliminary report.

Although the blue-green argon laser light has been used successfully to treat port-wine stains (PWSs) for many years, it produces substantial epidermal damage. We have previously shown in normal human skin that pulsed yellow tunable dye lasers (577-nm wavelength) can cause highly selective damage to cutaneous microvessels with minimal injury to the overlying epidermis. Pulsed tunable dye lasers also produce selective vascular injury in the abnormal vessels of PWSs, with clinically apparent lightening of the lesions. Both epidermal injury and fibrosis are less severe with this laser treatment than with argon and carbon dioxide laser treatments. Clinical and histologic responses of PWSs treated by argon, CO2, and pulsed yellow dye lasers were compared and followed up for one month in three patients. Although larger and longer-term clinical trials are necessary to fully evaluate this new treatment modality, it appears that pulsed yellow laser radiation offers a more selective, less traumatic, and probably superior form of treatment for PWSs.

Adult↗
PubMed1986

Facial granuloma associated with Trichosporon cutaneum infection.

A 23-year-old woman presented with Trichosporon cutaneum, which invaded deep into the dermis and subcutaneous tissue of the face and developed chronic granulomatous reactions. We postulated that the local use of an occlusive dressing with topical corticosteroid ointment in the early stage of the infection played a role in promoting the process of this opportunistic fungal infection. Antifungal chemotherapies, selected according to sensitivity testing to the isolated organism, were unsuccessful, mainly because of the acquired resistance of the organism to the chemical agent. Surgery was finally performed and a good result was obtained.

Adult↗
PubMed1985

Characterization of a dissimilatory-type sulfite reductase, desulfoviridin, from Desulfovibrio africanus Benghazi.

A desulfoviridin-type sulfite reductase having the alpha band at 638 nm was purified from Desulfovibrio africanus Benghazi (NCIB 8401) by chromatography on DEAE-cellulose, Sephadex G-200, and DEAE-Sepharose columns and by disc gel electrophoresis. The content of desulfoviridin in the soluble protein was estimated to be about 6% from the purification indexes. Like the typical desulfoviridin from D. vulgaris Miyazaki K, it formed mainly trithionate besides thiosulfate and sulfide in sulfite reduction coupled to hydrogenase and methyl viologen. No significant differences in the amino acid compositions, CD patterns in the UV (205-250 nm) region, and subunit structures were found, except for a pI value about 1 unit larger (pI 5.3). The split Soret (410 +/- 2 nm, less intense peak at 391 +/- 2 nm with a shoulder around 380 nm) and beta (584 +/- 2 nm) band maxima of the enzyme as isolated, and the visible absorption and fluorescence spectra of the acidic acetone-extracted chromophore were almost identical to those ascribed to sirohydrochlorin in spite of the reported difference in the native enzyme (alpha band maxima at 638 nm as against 628 +/- 2 nm in a typical desulfoviridin). Iron was the only significant chelatable metal contained in the chromophore. Some differences between africanus and vulgaris desulfoviridins were observed in the CD patterns in the UV to near UV region (250-340 nm) and also in the visible absorption spectra in the presence of dithionite.

Amino Acids↗
PubMed1985

Melanin macroglobules as a cellular marker of neurofibromatosis: a quantitative study.

To investigate the usefulness of melanin macroglobules (MMG) as a cellular marker for neurofibromatosis, their density was quantified in biopsies of café-au-lait spots (macules) (CALM) from 22 patients with von Recklinghausen's neurofibromatosis, 6 patients with bilateral acoustic neurofibromatosis, and 19 controls. The density of MMG was significantly higher in biopsies of the CALM of patients with von Recklinghausen's neurofibromatosis than in patients with bilateral acoustic neurofibromatosis (p less than .01) or controls (p less than .0008). The mode of acquisition of von Recklinghausen's neurofibromatosis (inherited vs new mutation) was not related to the density of MMG. On light microscopy, 14/22 (64%) patients with von Recklinghausen's neurofibromatosis had 11 or more MMG per 5 high-power fields. In contrast, none of the other two groups had more than 10 MMG per 5 high-power fields.

Adolescent↗
PubMed1985

Toxicity of polychlorinated biphenyl with special reference to porphyrin metabolism.

Oral administration of a commercial PCB mixture to chickens caused a hepatic-type porphyria characterized by hepatic accumulation and urinary excretion of uroporphyrin. To clarify the mechanism of the porphyrinogenic activity of these PCBs, we studied the structural requirement of synthetic PCB for porphyrinogenic activities by using the cultured chick embryo liver cells and examined the relationship between induction of delta-aminolevulinic acid (ALA) synthetase and inhibition of uroporphyrinogen decarboxylase. We established that the porphyrinogenic effect of PCBs exhibits a sharply defined structure-activity relationship in that only 3,4,3',4'-tetrachlorobiphenyl and 3,4,5,3',4',5'-hexachlorobiphenyl produced a marked accumulation of uroporphyrin. We also demonstrated that in ALA-supplemented cultures, these same compounds lead to accumulation of a large amount of uroporphyrin III, whereas with other PCBs, which were weak inducers of porphyrin synthesis, the accumulated porphyrin was mostly protoporphyrin. was mostly protoporphyrin. Kinetic studies of the sequential decarboxylation of uroporphyrinogen with purified uroporphyrinogen decarboxylase were performed. The 3,4,3',4'-tetrachlorobiphenyl and 3,4,5,3',4',5'-hexachlorobiphenyl strongly inhibit uroporphyrinogen decarboxylase directly at two steps, i.e. first in the formation of hexacarboxylic porphyrinogen III from heptacarboxylic porphyrinogen III and second in the formation of heptacarboxylic porphyrinogen III from uroporphyrinogen III. The results confirmed that porphyrinogenic PCBs primarily inhibit uroporphyrinogen decarboxylase, leading to a depletion of heme as a result of which synthesis of ALA synthetase increased.

5-Aminolevulinate Synthetase↗
PubMed1985

Decrease in human growth hormone (HGH) levels during transsphenoidal surgery for acromegaly as a guide for prognosis.

To evaluate the clinical significance of human growth hormone (HGH) dynamics during transsphenoidal microsurgery for acromegaly, serial HGH levels during the surgery were compared with the post-operative basal HGH levels in 15 acromegalic patients, retrospectively. In all patients, in whom the HGH level immediately after tumor resection was reduced below 5 ng/ml or the decreasing rate which stood for the magnitude of decrease of HGH during resection procedure was above 80%, postoperative permanent HGH levels fell to below 5 ng/ml, namely, within the normal range. The rapid radioimmunoassay (RIA) of HGH was developed by the use of high affinity antibody in order to inform the surgeons of plasma HGH levels quickly during the surgery. It is now possible to know HGH levels about 1 hour after submitting the samples. It was verified that HGH levels measured in the rapid RIA correlated well with those obtained in the conventional way. The rapid RIA method was applied to 6 patients and the correlation between HGH levels during the surgery and post operative levels was also studied prospectively. The results were essentially identical to those in a retrospective study. It was suggested that the HGH level immediately after tumor resection and the extent of the decrease in HGH during the resection procedure were good indicators of the prognosis of surgical results in acromegaly and the rapid RIA method was useful in order to judge HGH levels quickly during the surgery.

Acromegaly↗