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Biomedical subjects

H Okamura

Publications and source records attributed to H Okamura.

880 records · Page 49Linked to original sources

Why do some cancer patients with depression desire an early death and others do not?

Major depression is a well-documented risk factor for suicide in cancer patients as well as in the general population. However, there are no data explaining why some cancer patients suffering from major depression have suicidal ideation, while others do not. The authors investigated the background differences among cancer patients suffering from major depression with and without suicidal ideation by analyzing the consultation data of patients referred to the psychiatry division. Among the 1,721 referred patients, 220 (12.8%) were diagnosed with major depression, and of these 113 (51.4%) had suicidal ideation. Logistic regression analysis indicated that poor physical functioning and severe depression were significant risk factors. These preliminary findings suggest that the severity of major depression and physical functioning are important indicators of suicidal ideation among cancer patients.

Adaptation, Psychological↗

Orientation of stapedial nerve fibers in the facial nerve trunk.

By staining with toluidine blue and vital staining with methylene blue, the topographical orientation of the stapedial nerve fibers in the facial nerve trunk was visualized in adult guinea pigs. The stapedial nerve with its perineural sheath emerges from the facial nerve trunk in the posteromedial aspect of the upper part of the vertical portion. Toward the horizontal portion, the stapedial nerve fibers gradually ramify, lose their investments, and intermingle with other nerve fibers inside the facial nerve trunk. In the labyrinthine portion, the stapedial nerve fibers are distributed diffusely near the surface along the posterior, medial, and anterior margins of the facial nerve trunk. These findings lead to the conclusion that the stapedial nerve fibers of guinea pigs do not form a single funiculus throughout the intratemporal course of the facial nerve.

Animals↗

Wound healing of canine vocal folds after phonosurgery.

To develop phonosurgical techniques, the authors investigated the healing mechanisms of wounds on the vocal folds of canine larynges, and devised a method to cover the raw surfaces of such wounds. To restore the normal physiologic properties of the vocal folds, the normal mucosa should be removed as little as possible in phonosurgery. When the mucosa of the vocal folds is extensively removed by surgical intervention and the raw surface cannot be covered with the local pedicle flap, it should be covered with a free mucosal flap. We found an activated human fibrinogen concentrate, which is a biologic tissue adhesive, to be suitable for adhering a free mucosal flap to the raw surface by a laryngomicrosurgical approach.

Animals↗

Human leukocyte antigens in Bell's palsy.

Ninety-three patients with Bell's palsy including 12 members of two families with familial Bell's palsy were typed for human leukocyte antigens (HLAs). Significant association between HLAs and Bell's palsy was found. The association of certain HLAs with the palsy may predict the specific clinical course and prognosis.

Facial Paralysis↗

Danazol treatment for paroxysmal nocturnal hemoglobinuria.

Danazol was administered to two patients with paroxysmal nocturnal hemoglobinuria (PNH) with a dramatic effect on the hematological findings. The patients, 31- and 41-year-old females, were initially diagnosed as having aplastic anemia, and were initially treated with anabolic steroid and immunosuppressive therapy, respectively. Sugar water and Ham tests turned positive at the start of danazol therapy in the former patient and after two months in the latter patient. This drug produced a dramatic improvement in the hemoglobin level and the platelet count and showed few side effects in the patients. A possible mechanism of action of danazol for PNH is briefly discussed.

Adult↗

Thyroplasty type I (lateral compression) for dysphonia due to vocal cord paralysis or atrophy.

Based on the experimental results of thyroplasty, thyroplasty type I which aims at medical shifting the vocal cord was performed on 8 patients with dysphonia, 6 with vocal cord paralysis and 2 with vocal cord atrophy. The surgery was conducted on either in- or out-patient basis and local anesthesia was used. Usually, a rectangular incision was made on the thyroid cartilage at the level of the vocal cord, and the fragmemt was depressed inward. A cartilage piece taken from the opposite side was used as a wedge, if necessary, to enhance the effect of lateral compression of the vocal cord. The voice after surgery was generally satisfactory, except in one case of traumatic vocal cord paralysis. Complications such as stridor or dyspnea were nil. As surgical intervention inside the thyroid cartilage is minimal, fine and reliable adjustment of depression is possible during the surgery.

Adolescent↗

Electron microscopic study of muscle spindle in human interarytenoid muscle.

Using transmission electron microscopy, the fine structure of the muscle spindle in the interarytenoid muscle was studied. The specimen was made from a fresh adult male larynx which had been surgically removed. The muscle spindle showed the following characteristic features: (1) the capsule was thin, with only a small number of layers of capsular sheet cells; (2) the periaxial space was narrow and there were abundant collagenous fibrils; (3) the sensory endings consisted of irregularly coiled terminal axons with varicose swellings, and some endings penetrated the sarcoplasm; (4) one nuclear chain fiber terminated on the capsule, while the other branched into two bundles; and (5) special sarcoplasmic inclusions, possibly related to the sensory endings, were also observed. These findings suggest that the muscle spindle in the interarytenoid muscle is not only a very sensitive stretch receptor, but also a pressure receptor.

Aged↗

Vibratory patterns of normal and microscopically operated larynges. Observation of lower surface of vocal fold in dogs.

The authors investigated the effect of microsurgical intervention involving the canine larynx on vocal fold vibration. In normal cases both lower lips and free edges vibrated symmetrically. The lower lip coincided with the free edge and collided with that of the other side at the midline. Immediately after the collision, the lower lip rapidly retracted laterally at the beginning of a closed phase. It stayed in the most lateral position for the rest of the closed phase until the free edge started to move away laterally. The lower lip then began to move medially to occlude again with the other side. In cases subjected to microsurgery, a part of the mucosal layer of either the upper or the lower surface of the vocal fold was removed. Several weeks after the procedure, vibration was observed. In either case, vibration of the free edge of the operated vocal fold diminished in amplitude and often became earlier in phase than that of the contralateral fold. Usually the lower lip of the operated vocal fold moved away more slowly. In addition, when the extent of epithelial removal was large, the lower lip itself was not elicited.

Animals↗

Morphologic changes in intercostal muscle tissue associated with a viper (Agkistrodon halys blomhoffi) bite.

This study examined a 73-year-old woman who had been bitten in the right thumb by a viper (Agkistrodon halys blomhoffi). She suffered acute renal failure and respiratory failure after the bite. On the 20th day, respiratory failure persisted, although she had recovered from renal failure. Intercostal muscles were obtained by biopsy on the 40th day after the bite. Specimens were observed with enzyme-histochemical and electron microscopic techniques. The size of muscle fibers varied. Most of the smaller muscle fibers were enzyme-histochemically type 2C fibers. This was considered to be the regenerative stage of acute rhabdomyolysis. Ultrastructurally, two opposite types of changes, degeneration and regeneration, were mixed in the same areas. Muscle fibers might be continuously degenerated, and the regenerative fibers might also be degenerated. This study suggests that some slow allergic reactions to snake venom might bear some relation to the degenerative changes.

Aged↗

Inhibition by interleukin 18 of osteolytic bone metastasis by human breast cancer cells.

Effects of interleukin (IL)-18 on experimental bone metastasis of human breast cancer cells, MDA-231 cells, in nude mice were investigated. In addition, effects of IL-18 on subcutaneous growth of MDA-231 cells were examined. Bone metastasis was produced by an intracardiac injection of MDA-231 cells. Twenty eight days after the cell injection, severe osteolytic bone metastasis was examined by X-ray radiography, and both non-osteolytic and osteolytic bone metastases were examined microscopically. IL-18 (1 microgram/mouse) was injected intraperitoneally according to protocols A and B. In protocol A, IL-18 was injected daily from day 7 after an intracardiac or subcutaneous injection of cells, and in protocol B, it was injected daily for 7 days each before and after the cell injection. In protocol A, IL-18 injections significantly suppressed both the incidence of osteolytic bone metastasis detected by X-ray radiography (about 80% vs. about 20% for the control group vs. the treatment group) and the number of its foci/mouse (1.6 vs. 1 for the control group vs. the treatment group). However, they did not cause significant effects on either the incidence of bone metastasis detected microscopically or the number of its foci/mouse. In protocol B, IL-18 injections caused no significant effects on either the incidence of osteolytic bone metastasis detected by X-ray radiography or the number of its foci/mouse. They caused no significant effects on the incidence of bone metastasis detected microscopically, but significantly decreased the number of its foci/mouse (about 2.0 vs. about 1 for the control group vs. the treatment group). In both protocols A and B, IL-18 injections produced no significant effect on the tumor take and subsequent growth of tumors after a subcutaneous injection of the cancer cells. Since in protocol A, IL-18 appears to have exerted its action after establishment of metastasis by cancer cells to the bone marrow, the effects of IL-18 found in Protocol A indicate that IL-18 inhibited osteolytic growth at bone metastatic sites of breast cancers. On the other hand, since in protocol B IL-18 is likely to have functioned around the time when lodging of cancer cells and early development of metastasis occur in the bone marrow, the effects of IL-18 found in Protocol B indicate that the cytokine also suppresses an early stage of bone metastasis of breast cancers, although, this effect was less apparent than the effect on osteolytic growth. Therefore, IL-18 may be useful for suppression of osteolytic bone metastasis which is a serious problem in patients of advanced breast cancers.

Animals↗

Association of the missense Glu298Asp variant of the endothelial nitric oxide synthase gene with severe preeclampsia.

OBJECTIVES: A large number of studies suggest that abnormalities in nitric oxide (NO) synthesis may contribute to the development of preeclampsia. We recently identified a variant within exon 7 of the endothelial NO synthase (eNOS) gene: G to T conversion at nucleotide position 894 resulting in replacement of glutamic acid with aspartic acid at codon 298 (Glu298Asp). We analyzed the association between the Glu298Asp eNOS gene variant and preeclampsia. STUDY DESIGN: The study included 152 preeclampsia patients (35 mild, 80 severe, and 37 superimposed) and 170 control subjects. Screening for the Glu298Asp eNOS gene variant was carried out by analysis of polymerase chain reaction-restriction fragment length polymorphism. RESULTS: The frequency of the Glu298Asp variant was significantly higher in the severe preeclampsia group (28.8%) than in the control (14.1%; p <. 01), superimposed preeclampsia (8.1%; p <.01), and mild preeclampsia (11.4%; p <.01) groups. CONCLUSIONS: We conclude that the presence of the Glu298Asp eNOS gene could be a marker of increased risk of developing severe preeclampsia.

Adult↗

Correlation of CT patterns with histologic findings in parauterine masses.

CT findings were correlated with histologic and surgical findings in 162 parauterine masses. CT findings were classified into four types and 14 patterns. These classifications were useful in the diagnosis and differential diagnosis of parauterine masses. Malignant ovarian tumors, uterine myogenic tumors, metastatic tumors, endometrial cysts, and benign cystadenoma revealed characteristic CT findings, making differential diagnosis possible on CT. Contrast enhancement of the solid part, bilaterality, and the presence of ascites were useful for differential diagnosis. Although CT is one of the major modalities for the diagnosis of intrapelvic mass lesions, MR imaging will be another important method for the delineation and characterization of these lesions in the future.

Adult↗

Estrogen receptor expression in the genital tract of female mice treated neonatally with diethylstilbestrol.

The distribution of the estrogen receptor (ER) was investigated immunohistochemically in the genital tract of 0 (day of birth)--to 50-day-old C57BL/Tw female mice given 5 daily injections of 2 micrograms diethylstilbestrol (DES) from the day of birth using an anti-ER monoclonal antibody. In the oviduct, cervix and vagina of control mice, both epithelial and stromal cell nuclei showed positive ER immunoreaction at 0 day. Nuclei of uterine stromal cells also showed strong ER immunostaining even at 0 day. In contrast, the ER in uterine epithelial cells began to appear by day 5. The number of positive epithelial cells and staining intensity gradually increased until 10 days. In neonatally DES-exposed mice, ER appeared in uterine epithelial cells 24 h after the injection. Polygonal cells appearing in the vaginal epithelium of DES-exposed 3-day-old mice showed weak ER staining. Neonatal DES exposure reduced staining intensity of columnar vaginal epithelial cells and uterine stromal cells at 3 days. Vaginal epithelial cells undergoing ovary-independent stratification and cornification in neonatally DES-exposed mice and normal estrous mice showed ER immunoreaction only in the basal cells.

Animals↗