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Biomedical subjects

A Sakuma

Publications and source records attributed to A Sakuma.

At least 19 recordsLinked to original sources
PubMed2000

Spontaneous luxation of encapsulated intraocular lens onto the retina after a triple procedure of vitrectomy, phacoemulsification, and intraocular lens implantation.

PURPOSE: To report the clinical and histological findings of a luxated intraocular lens (IOL) in the capsular bag. METHODS: Review of a case. RESULTS: Twenty-three months after a triple procedure of vitrectomy, phacoemulsification, and IOL implantation for diabetic vitreous hemorrhage and cataract, the encapsulated IOL spontaneously luxated. Scanning electron microscopy showed sparsely distributed anterior and equatorial zonules, with only a few posterior zonules on the surface of the removed capusular bag. CONCLUSION: The absence of the anterior hyaloid membrane and posterior zonules and contraction of the lens capsule may cause dialysis of the zonules. Therefore, the anterior hyaloid membrane should be left in place in patients at low risk for the development of postoperative proliferation to maintain the long-term stability of the IOL.

Aged↗
PubMed2000

Aging effects upon smooth pursuit induced by step-ramp stimulation.

OBJECTIVE: in predictable target movements, pursuit gains are extremely close to 1.0. Under these conditions, aging effects upon pursuit have not been detected. Step-ramp stimuli produced by unpredictable combinations would be favorable procedures to assess the properties of smooth pursuit between young and aged people. METHODS: the target was a 0.5 degrees red laser spot. Eye movements of 49 normal subjects (26 younger subjects less than 49 years old and 23 older subjects more than 50 years old) were recorded with infrared reflection oculography and sampled at 250 Hz. Step direction and distance (2, 4, 6, 8 degrees) followed by 10 degrees /s ramp speed movement in the same (onward stimulus) or opposite to the direction (backward stimulus) were programmed in an unpredictable way before each set of ten tests. Both onward and backward stimulation were randomly given for each subject. RESULTS: in the onward study, there was a close correlation between retinal slip velocity (RSV) and eye acceleration (EA), which was expressed as a regression curve, being steeper in the younger group. This means that the younger subjects could produce faster velocity and greater acceleration than the aged group (P<0.05). CONCLUSION: subtle reduction in visual acuity, visual fields and contrast sensitivity will be one of possible causes, and the degradation of cortical areas crucial for visual processing might be one of possible causes of slowing of pursuit EA.

Acceleration↗
PubMed2000

Influence of vibration to the neck, trunk and lower extremity muscles on equilibrium in normal subjects and patients with unilateral labyrinthine dysfunction.

To investigate the role of proprioceptors of different skeletal muscles in postural control, in normal subjects and patients with unilateral labyrinthine dysfunction (ULD), the effect of vibration on these muscles was studied by postulography. The subjects comprised 59 normal subjects and 12 patients with ULD due to resection of acoustic tumours. Sagittal body sway was observed during vibration to the triceps surae, tibialis anterior and upper dorsal neck muscles. No significant change in sway was observed in the frontal plane in normal subjects. Significant differences between normal subjects and patients were found on stimulation of the muscle groups of triceps surae and biceps femoris during vibration. In patients with ULD, vibration to the dorsal neck muscles caused a deviation towards the diseased side. It can be speculated that the upper dorsal neck muscle plays an important role in maintaining the body balance in the frontal plane in patients with ULD. On the other hand, the lower extremity muscles, especially the muscles on the dorsal side of the body, play a significant role in adjusting the standing posture in the sagittal plane.

Adult↗
PubMed2000

[Endonasal transsphenoidal surgery under local anesthesia for elderly patient with pituitary tumor: case report].

We present a surgical case under local anesthesia of an 88-year-old woman suffering from visual disturbance caused by pituitary adenoma. Magnetic resonance (MR) imaging showed a large pituitary tumor with suprasellar extension compressing the chiasmatic nerve. Neither she nor her family would agree to surgical therapy. However, when we proposed surgery under local anesthesia, they accepted it. Partial removal of the tumor via the endonasal transsphenoidal approach was carried out, uneventfully. The nasal surface was infiltrated with 4%-Xylocaine prior to the ordinary xylocaine injection to the nasal mucosa. The patient did not complain of any pain associated with the surgical procedure, including saline injection to the subarachnoid space through spinal drainage. The postoperative course was fine except for the temporarily appearance of diabetes insipidus. Postoperative MR imaging showed complete relief of compression to the chiasmatic nerve. Her visual field was improved dramatically. Endonasal transsphenoidal surgery under local anesthesia is thought to be one of the most useful methods of choice, especially in cases of elderly patient with pituitary tumor.

Adenoma↗
PubMed1999

[Influence of proprioceptive input from leg, thigh, trunk and neck muscles on the equilibrium of standing].

To investigate and compare the roles of proprioceptive input from the leg, thigh, trunk and neck muscles on equilibrium, we performed static posturography in 50 normal subjects in the standing position on a force platform by applying vibratory stimulations to the muscles. The length of the displacement of the center of gravity, maximum sway length and sway area were measured. The amplitude of the body sway was maximum when the stimulation was applied to the dorsal neck. The forward shift of the center of gravity was also marked by stimulation applied to the dorsal neck. The amplitude of the body sway on stimulation of the leg muscles was also marked, although less than that of dorsal neck stimulation. The backward shift during stimulation of the gastrocnemius and the forward shift during stimulation of the anterior tibialis were remarkable. The results indicate that the leg muscles, which directly regulate the movement of the ankle joint, and the dorsal neck muscles, which change the static equilibrium through the central nervous system, are important for maintaining the standing posture.

Adult↗
PubMed1998

A long term follow-up of a randomized trial comparing interferon-alpha with busulfan for chronic myelogenous leukemia. The Kouseisho Leukemia Study Group.

To evaluate the long-term effectiveness of interferon-alpha (IFN-alpha) therapy in patients with chronic myelogenous leukemia (CML) in chronic phase, we examined the updated outcomes of 159 patients who had been enrolled between 1988 and 1991 into a randomized trial comparing IFN-alpha with busulfan. At a median follow-up of 73 months, the median survival was 71 months in the IFN-alpha group and 55 months in the busulfan group (P=0.0563), and the median time of remaining in chronic phase was 58 months in the IFN-alpha group and 39 months in the busulfan group (P=0.4676). Landmark analysis showed a significant advantage in survival (P=0.009) and duration of chronic phase (P=0.0001) in patients with any cytogenetic response among the IFN-alpha group. About half patients were discontinued IFN-alpha administration in spite of cytogenetic response in this study. It appears that continuation of IFN-alpha might possibly confer a survival advantage. Pretreatment factors associated with cytogenetic response included high hemoglobin level, low percentage of peripheral basophils and low leukocyte counts. Multivariate analysis identified lower percentage of bone marrow basophilia (P=0.007) for survival advantage. If a group with a very good prognosis is predicted by a new prognostic model, it might be an option to wait for bone marrow transplantation.

Adult↗
PubMed1998

Objective tinnitus caused by an aberrant internal carotid artery.

We report the case of a 29 year-old woman who complained of pulsatile tinnitus and impaired hearing. On otoscopic examination, her right tympanic membrane was observed to be in contact with a mass in the middle ear cavity, with the formation of a meniscus at the point of contact. Using a high-sensitivity microphone inserted into the external auditory canal, we recorded pulsatile tinnitus that was synchronous with the electrocardiogram. Magnetic resonance angiography revealed that the middle ear mass was an aberrant internal carotid artery coursing through the hypotympanum.

Adult↗
PubMed1998

[A clinical phase III trial of ulinastatin (MR-20) for nephrotoxicity of cisplatin].

UNLABELLED: MR-20 was administered to 140 lung cancer patients who presented with nephrotoxicity due to cisplatin (CDDP) treatment at 59 institutions throughout Japan during the period from September 1992 through March 1994 to study its suppressive effect on the nephrotoxicity as well as its safety. The results are reported in this paper. METHODS: The efficacy and usefulness of MR-20 were studied in a placebo-controlled, double-blind manner. An efficacy rate of 58.7% was achieved in the MR-20 group, and 36.8% in the placebo group: MR-20 was significantly more effective for nephrotoxicity than placebo (U-test). Serum Cr, Ccr and FENa were prevented from significant variations in the MR-20 group, compared with the control group. It was considered that MR-20 is a safe drug, and that it is useful in suppressing the nephrotoxicity of CDDP treatment.

Adult↗
PubMed1996

Randomized study of vinorelbine (VRB) versus vindesine (VDS) in previously untreated stage IIIB or IV non-small-cell lung cancer (NSCLC). The Japan Vinorelbine Lung Cancer Cooperative Study Group.

PURPOSE: We compared the activity of vinorelbine (VRB) and vindesine (VDS) in a randomized crossover study in patients with previously untreated stages IIIB or IV non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Two hundred four patients were assessable for response and toxicity. VRB was administered at a dose of 25 mg/m2 weekly and VDS at a dose of 3 mg/m2 weekly. Patients who failed to respond after 4 cycles of initial monotherapy were switched to a combination chemotherapy (VRB-->VDS + cisplatin (P) or VDS-->VRB + P). RESULTS: Objective response was observed in 31.1% of patients in the VRB arm versus 8.9% of those in the VDS arm (P = 0.0002). The median duration of response to VRB was 18.5+ weeks (range, 7.9 to 107.5+ weeks) compared with 11.7+ weeks (range, 6.0 to 35.0+ weeks) for VDS. Of the 69 patients who failed to respond to initial monotherapy, 33 in the VRB group who subsequently received VDS + P did not respond and 13 (26.5%) of 49 initially on VDS who received subsequent VRB + P responded. The rates of grades 3 and 4 leukopenia were similar in the two monotherapy arms (VRB, 55.3% vs. VDS, 48.5%). However, grade 3 anemia was more frequent in the patients on VRB than in those on VDS. The incidence of peripheral neurotoxicity was significantly higher with VDS than with VRB (P = 0.002), but VRB induced a slightly higher rate of local cutaneous reaction than VDS (P = 0.012). With the combination of cisplatin and these vinca alkaloids, peripheral neurotoxicity was less frequent in the VRB group than in the VDS group. CONCLUSION: Our results demonstrate that VRB yields a higher response rate than VDS in stage IIIB or IV NSCLC, with the same extent of toxicity in terms of leukocytopenia. The peripheral neurotoxic effects were also milder with VRB than with VDS. In second-line chemotherapy, there was a notable difference in response between the VRB + P and VDS + P regimens.

Adult↗
PubMed1996

Vertical optokinetic nystagmus in normal individuals.

In this study, 20 subjects (5 women and 15 men, 22-28 years old) were tested for vertical optokinetic nystagmus (OKN) to establish the asymmetry between up and down OKN responses in humans. The subjects were exposed to both upward and downward OKN stimulus at constant velocities of 30, 40, 50, 60, 70, 80, 90 degrees/s in the upright position. Eye movements were recorded precisely using the magnetic search coil system in order to eliminate any methodological problem associated with the eye-lid artifact. Slow phase velocity during upward OKN stimulus was higher than that during downward OKN stimulus for each OKN velocity. It is likely that otolithic stimuli cause up and down asymmetry. Statistical significance in the gain between upward and downward OKN was noted for stimulus velocities of 30-60 degrees/s (p < 0.01), but not for higher velocities, because vertical OKN saturated around 40-50 degrees/s.

Adult↗
PubMed1996

Primary position upbeat nystagmus with special reference to alteration to downbeat nystagmus.

A 24-year-old man was admitted to the University Hospital showing severe dehydration that might have been the result of medicine-induced gastritis. Wernicke's encephalopathy was suspected in this patient. On admission, primary position upbeat nystagmus (PPUN) was found. The patient showed tongue fasciculation and loss of gag reflex, which, however, soon returned to normal. Electronystagmographic (ENG) findings were suggestive of lesions in the brainstem. Based on neurological signs and symptoms, we concluded caudal brainstem lesions might be a possible site responsible for the upbeat nystagmus. This nystagmus, however, was later found to be reversed to downbeat nystagmus. This is considered to have been due to predominant differences in vertical velocity which are induced by gravity.

Brain Stem↗
PubMed1995

Myotonic dystrophy with alveolar hypoventilation and hypersomnia: a clinicopathological study.

We present a case of myotonic dystrophy accompanied by alveolar hypoventilation and hypersomnia. Case history, pulmonary function tests, polygraphic recording, and multiple sleep latency test, concomitant with a restrictive ventilatory abnormality, suggested a central origin of alveolar hypoventilation and hypersomnia in our case. The most significant neuropathological findings were in the tegmentum of the brain stem. Severe neuronal loss and gliosis were observed in the midbrain and pontine raphe, particularly in dorsal raphe nucleus and superior central nucleus. Pontine and medullary reticular formation also showed a marked cell loss and fibrillary gliosis. The alveolar hypoventilation and the hypersomnia in our case may be attributed to these morphological abnormalities, and would appear to be central in nature.

Disorders of Excessive Somnolence↗
PubMed1995

Visually guided eye movements in patients with Wallenberg's syndrome.

To determine the lesions and the lateralization in patients with Wallenberg's syndrome, visually-guided eye movements were quantitatively analysed and these findings were compared with a lesioned site as revealed by magnetic resonance imaging (MRI). The 8 patients could be clearly classified into two subgroups based on the functional test of eye movements. In 4 patients, optokinetic nystagmus (OKN), pursuit eye movements and fixation-suppression of caloric nystagmus (FS), utilizing the slow phase velocity as a parameter, were impaired toward the lesioned side in the medulla. In the remaining 4 patients, OKN and pursuit eye movements were impaired toward the side contralateral to the lesion, whereas FS toward the lesioned side, indicating a lesion affecting not only the medulla but also the inferior peduncle and/or the cerebellum. Therefore, the functional visually-guided eye movements can provide a useful test battery with which to detect the lesion site in Wallenberg's syndrome.

Angiography↗
PubMed1995

Aging effects upon pursuit eye movements.

Quantitative assessment of aging effects upon pursuit eye movements was done in step-ramp stimulus conditions using 32 normal individuals. Eye movements were recorded with infrared reflection oculography. The target was a spot of 0.5 degree red lazar light. The light spot was blanked for 5 ms while the mirror galvanometer moved to a new position. Eye and target position were sampled at 250 Hz and analysed by a personal computer. In onward stimulation in which 2 degrees, 4 degrees, 6 degrees and 8 degrees position steps were followed by fixed ramp speed (10 degrees/s), and also in backward stimulation in which 2 degrees, 4 degrees, 6 degrees step positions were followed by 9 degrees, 17 degrees and 27 degrees/s, eye acceleration increased depending upon increase of retinal slip velocity in the younger group below 49 years. Among the factors effecting aging effects, the cerebrum might be important because visual recognition and eye acceleration are performed in the parietal lobe.

Adult↗
PubMed1994

Age-related decreases in the reconstituting ability of hemopoietic cells and the ability of hemopoietic microenvironment to support hemopoietic reconstitution in senescence accelerated (SAM-P) mice.

The effect of the aging process on the hemopoietic system in senescence-accelerated (SAM-P) mice with respect to the reconstituting ability of hemopoietic cells and the ability of the microenvironment to support hemopoietic reconstitution was investigated by bone marrow transplantation (reconstitution assay). When the bone marrow cells, obtained from young or old mice, were transplanted to lethally irradiated young SAM-P mice no difference in the reconstituting pattern of femoral spleen colony-forming units (CFU-S), splenic CFU-S and splenic granulocyte macrophage colony-forming units (CFU-GM) was observed between the mice transplanted with young and old donor cells. However, the reconstitution of femoral CFU-GM in mice transplanted with old donor cells was delayed compared to that in mice transplanted with young donor cells. Moreover, the recovery of WBC in mice transplanted with old donor cells was noticeably delayed. When the bone marrow cells obtained from young mice were transplanted to young or old recipient mice, no difference in the reconstituting pattern of femoral CFU-S and CFU-GM as well as splenic CFU-S and CPU-GM was observed between young and old recipient mice. However, the recovery of WBC in old recipient mice was noticeably delayed. These data indicate that the functions of both the hemopoietic cells and the hemopoietic microenvironment deteriorated with age in SAM-P mice.

Aging↗
PubMed1994

A phase II study of vinorelbine, a new derivative of vinca alkaloid, for previously untreated advanced non-small cell lung cancer. Japan Vinorelbine Lung Cancer Study Group.

To evaluate the effectiveness of vinorelbine (NVB) in patients with non-small cell lung cancer (NSCLC), a late Phase II study was conducted. A total of 80 patients with Stage III or IV NSCLC who had no previous therapy were entered into the study. Seventy-nine patients were eligible for response and toxicity. NVB was administered weekly by intravenous injection at a dose of 25 mg/m2 in 20 ml of saline and was generally administered in four cycles or more, unless patients had disease progression. Of the 79 eligible patients, 23 (29.1%) showed a partial response (95% confidence interval, 19.1-40.4%). The median duration of partial responses was 14.7+ weeks. The median survival time for all patients was 40.1+ weeks. The major toxicity was leukopenia. Grade 3 and 4 leukopenia occurred in 48 patients (60.8%). Other toxicities of grade 3 or more included anemia (6.3%), local cutaneous reaction (3.8%), pneumonitis (1.3%), nausea and vomiting (1.3%), mucositis (1.3%) and constipation (1.3%). The absolute dose-intensity of NVB was 22.33 mg/m2/week. A weekly schedule of intravenous administration of 25 mg/m2/week of NVB was reasonable for maintenance of activity, and acceptable for toxicity in the chemotherapy of advanced NSCLC.

Adult↗