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Biomedical subjects

H Oyama

Publications and source records attributed to H Oyama.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Successful management for chemorefractory testicular cancer with brain and lung metastases. A case report].

This is a report of successful management for a far advanced, chemorefractory testicular cancer patient. A 29-year-old male was referred to our hospital for the treatment of progressive lung metastases with elevated hCG level, which had recurred after complete remission following 3 courses of BEP chemotherapy and progressed after transient partial regression following 2 courses of intensified EP chemotherapy. In addition, a 3 cm in diameter, solitary brain metastasis was detected on CT. First, we performed wedge resection of bilateral pulmonary lower lobe for chemorefractory pulmonary metastases. Histological examination revealed viable embryonal carcinoma identical to the primary one. Thereafter, whole brain irradiation in combination with VIP chemotherapy (etoposide 100 mg/m2, cisplatin 20 mg/m2 and ifosfamide 1200 mg/m2 daily for 5 consecutive days) was carried out to treat brain metastasis. By 2 cycles of VIP therapy and irradiation (36 Gy), partial tumor regression and normalization of hCG level were achieved, leading to salvage surgery of the brain metastasis which histologically proved to be necrosis. Following an additional cycle of VIP therapy, the patient has been free of recurrence 24 months after completion of the treatment.

Adult↗
PubMed1998

Bedside wellness--development of a virtual forest rehabilitation system.

The present study aims at the development of a new concept system that will contribute toward improving the quality of life for bedridden patients and the elderly. The results of a basic study showed the possibility of a virtual reality system reducing stress and pain, provided VR sickness does not occur. A Bedside Wellness System which lets a person experience a virtual forest walk and provides a facility of rehabilitation was proposed based on the basic study and developed. An experiment to assess the developed system using healthy subjects was executed. The data suggested the positive effects of the system; however, some points to be improved were also extracted. After a few improvements, the system will be available for clinical use.

Adult↗
PubMed1998

The clinical advantages of editable real-time volume rendering in a medical virtual environment: VolMed.

Segmentation for a medical virtual environment is a process of image diagnosis. It should be performed by clinical doctors, otherwise the data may be meaningless for using clinical purposes. At the National Cancer Center, in Japan, we have recently developed interactive, editable real-time volume rendering software (VolMed), based on Volren-6 software, with the ability to interactively edit the 3D images of a patient's virtual cancer and virtual organs, in a virtual environment. Doctors can see proposed solutions to clinical problems as 3D images, using real-time volume rendering. We conclude that interactive editing is very important for clinical use, and also decreases the time required to create the virtual cancer images used for surgical simulation, pre-surgical planning and 3D invasion diagnoses.

Algorithms↗
PubMed1998

Virtual reality for palliative medicine.

The technology of virtual reality (VR) offers several advantages in the field of medicine because it enables us to practice medical procedures repeatedly, and can provide a variety of experiences by using virtual organs in different patients. It also aids in learning about a clinical procedure and facilitates objective evaluation by a supervisor. In the field of clinical oncology, a virtual environment can be useful for simulating surgery, diagnosing cancer invasion, obtaining informed consent or enhancing patient education, and for clinical communication using network-based VR. This technology can also be used to improve a patient's living conditions and to treat the psychological problems and/or stress of cancer patients. In the present chapter advanced VR research for palliative medicine at the National Cancer Center Hospital Japan is described and discussed.

Computer Simulation↗
PubMed1998

Possibility of virtual reality for mental care.

The possibility of applying Virtual Reality (VR) techniques to the mental care of patients is discussed in this chapter. VR technology holds much promise for providing supportive activities and promoting cooperation among caregivers. Interactivity with media may give the feeling of control to patients and thus provide a greater joy than passively watching television. Immersion in VR is expected to reduce pain and relieve anxieties for a while. Some kinds of VR content would make patients relaxed or encourage them in their fight against disease. Moreover, networked VR could offer a virtual space where patients meet, communicate, organize activities, and share experiences with other people--other patients, friends, family members, medical doctors, social workers, and so on. A basic study and trials to evaluate our developed VR system, called the 'Bedside Wellness System,' provide evidence for the effectiveness of this approach. Future research tasks are also discussed.

Adult↗
PubMed1998

[Metastatic renal tumor originating from lung cancer: a case report].

A 45-year-old house-wife, who had undergone surgical treatment for lung adenocarcinoma 2 years previously, presented with a left renal mass detected by follow-up CT. During 7 months of observation, it rapidly enlarged from 1 cm to 3 cm in maximum diameter. Although the short doubling time (40 days) suggested that the tumor was metastatic, abdominal urtrasonography, angiography and CT scan did not exclude primary renal cell carcinoma. Left nephrectomy was performed. Histologically, the tumor proved to be metastasis from the previous lung adenocarcinoma. She has been alive with pulmonary recurrence 13 months after nephrectomy. The doubling time of the tumor may be one of the key factors in differentiating a metastatic renal tumor from a primary carcinoma.

Adenocarcinoma↗
PubMed1998

[Two cases of subarachnoid hemorrhage associated with neurofibromatosis type I: a case of multiple cerebral aneurysms and arteriovenous malformation, and another case of an anterior communicating artery aneurysm].

Two cases of subarachnoid hemorrhage associated with neurofibromatosis type I (von Recklinghausen's disease) are reported. A 30-year-old male patient (case 1) had been diagnosed as having neurofibromatosis type I due to neurofibroma and café-au-lait spot. He suffered from subarachnoid hemorrhage and angiography showed multiple aneurysms in the right and left middle cerebral arteries and left internal carotid artery. He also had arteriovenous malformation in the left temporal lobe. Case 2 was that of a 62-year-old female patient with neurofibroma and café-au-lait spot. She suffered from subarachnoid hemorrhage and angiography showed an aneurysm in the anterior communicating artery. Both patients were discharged with no deficits after neck clipping, however they both suffered from large-sized hematoma in the punctured site of the femoral artery after angiography. The cerebral aneurysms associated with neurofibromatosis type I are often multiple and may coexist with arteriovenous malformation.

Adult↗
PubMed1998

[A case of labial adhesions in an elderly woman].

A 90-year-old woman was admitted with a chief complaint of difficulty in urination. She had severe labial adhesions with a pin point opening. Urinary tract infection was detected by urine examination. The adhesions were surgically dissected under local anesthesia and recurrence was not seen at follow-up 6 months after the operation. Labial adhesions in adult women are rare and only 28 cases of labial adhesions in adults have been reported in the Japanese literature. Labial adhesions in adults may be more closely related with chronic inflammation such as recurrent urinary tract infections and vulvovaginitis than in pediatric cases.

Aged↗
PubMed1998

[Improvement of cognition after trepanation for the chronic subdural hematoma].

The cognitive functions were examined in the pre- and post-operative stages about the 16 cases of the chronic subdural hematoma. The evaluation was performed with MMS (mini-mental state) test. Although the average of the total score was 16.6 in the preoperative stage, it increased to 22.7 in the postoperative stage. Orientation of time and place, recall and the ability of writing a sentence, which were impaired prominently in the preoperative stage, improved significantly in the postoperative stage. The improvement was poorer in the patients with gait instability and in those older than 80 years. Trepanation surgery seems to be efficient for the improvement of cognition.

Aged↗
PubMed1998

CBF change with aging in moyamoya disease.

The change of cerebral blood flow (CBF) with aging was analyzed in 9 cases of moyamoya disease whose age ranged from 16 years old to 58 years old. CBF decreased more prominently in the various lobes with aging than control subjects and the decrement was more rapid in the affected side than in the non-affected side. CBF was thought to decrease with the hemorrhagic attack and the accompanying neurological deterioration. However the gradually-deteriorating brain damages caused by the chronic hypoperfusion also might be engaged in this CBF decrement.

Adolescent↗
PubMed1997

Effect of glycerol on blood flow distribution in tumoral and peritumoral brain tissue.

To evaluate the effect of glycerol, thirty-two patients with brain tumor were directed to the study, including 17 gliomas and 15 meningiomas. Blood flow before and after the administration of glycerol were measured with Xe CT. Glioma was significantly hypo-perfused. The peritumoral edema of glioma and meningioma were also hypo-perfused. On the other hand, Meningioma was significantly hyper-perfused. After the administration of glycerol, blood flows were increased except for glioma. We suggested that, vascular responses to glycerol was different in the two tumor types. The steal phenomena of blood flow might occur in glioma.

Brain Neoplasms↗
PubMed1997

Detection of interstitial pneumonitis in patients with rheumatoid arthritis by measuring circulating levels of KL-6, a human MUC1 mucin.

In rheumatoid arthritis (RA), interstitial-pneumonitis is one of the major extraarticular complications that worsens a patient's prognosis. KL-6, a human MUC1 mucin, has been reported to be a sensitive serum marker for activity of interstitial pneumonitis. We investigated the clinical significance of serum KL-6 level in patients with RA. Serum levels of KL-6 and RA-associated inflammatory markers were evaluated in 177 RA patients. The diagnosis of active interstitial pneumonitis was made by clinical symptoms, pulmonary function tests, chest X-ray film, and high resolution CT. Serum KL-6 was increased in 8 of 9 (88.9%) RA patients with active interstitial pneumonitis but in only 1 of 168 (0.6%) RA patients without active interstitial pneumonitis. No significant correlation was found between KL-6 level and conventional clinical parameters. In RA, abnormal elevation of serum KL-6 strongly indicates the complication of active interstitial pneumonitis.

Adult↗
PubMed1997

Intractable diarrhoea associated with secondary amyloidosis in rheumatoid arthritis.

OBJECTIVE: To examine the clinical characteristics of intractable diarrhoea associated with secondary amyloidosis in rheumatoid arthritis (RA). METHODS: Of 179 RA patients with biopsy confirmed secondary amyloidosis, 24 cases (23 women and one man) with intractable diarrhoea lasting for more than one month were retrospectively evaluated. RESULTS: The mean (SD) duration of diarrhoea was 87 (64) days. Prodromal symptoms of gastrointestinal dysfunction (n = 21) and impaired peristalsis (n = 16) were observed. Laboratory data showed hypoproteinaemia (4.7 (0.85) g/dl) caused by malabsorption or protein loss and high values of C reactive protein (17.0 (9.3) mg/dl). Recurrence of intractable diarrhoea (n = 4) and transition from intractable diarrhoea to other gastrointestinal problems of amyloidosis (ischaemic colitis (n = 2) and intestinal pseudo-obstruction (n = 4)) were observed. In 19 patients (25 episodes) the duration of intravenous hyperalimentation at remission (18 episodes) was 68 (52) days. Corticosteroid pulse therapy was administered to 10 patients (11 times) and the time elapsed from the end of corticosteroid pulse therapy to the end of diarrhoea was 18 (14) days. One and five year survival rates after the onset of intractable diarrhoea were 73.4% and 38.9%. Seven of 13 patients (54%) had died as a result of infectious diseases. CONCLUSION: Intractable diarrhoea associated with secondary amyloidosis in RA is a serious clinical entity and the prognosis is poor. Although it is assumed that intravenous hyperalimentation treatment and corticosteroid pulse therapy are favourable regimens for intractable diarrhoea, the patients should be monitored for possible infectious complications.

Adult↗
PubMed1997

Isolation of propioxatin A from Actinosynnema sp. SI-23 during a screening for Serratia piscatorum metalloproteinase inhibitors.

An inhibitor of Serratia metalloproteinase was found in the cultured broth of strain SI-23, which was identified to be Actinosynnema sp. The inhibitor had a potent inhibitory effect on Serratia metalloproteinase and a weak effect on thermolysin, but no effect on other groups of proteinases. The structure of the inhibitor was deduced to be propioxatin A, reported as an enkephalinase B inhibitor.

Actinomycetales↗
PubMed1997

Abnormal cerebral blood flow associated with antiphospholipid antibody syndrome--four case reports.

Patients with antiphospholipid antibody syndrome manifesting as neurological symptoms (one patient with twice repeated cerebral ischemic symptoms in the left parietal and frontal lobes, and the other patient with cerebral infarction of the right temporal lobe) and non-neurological symptoms (one patient with occlusion of the superior mesenteric artery and the other patient with thrombophlebitis) underwent cerebral blood flow (CBF) studies using xenon-enhanced computed tomography. The patients with neurological symptoms had decreased CBF at the affected sites. The patients with non-neurological symptoms had decreased CBF in the left parietal and temporal lobes and/or corona radiata. Subtle preclinical thrombosis may cause chronic cerebral hypoperfusion in patients with antiphospholipid antibody syndrome.

Adult↗
PubMed1997

Effect of cisternal papaverine on cerebral blood flow in patients with subarachnoid hemorrhage--three case reports.

Three patients presenting with subarachnoid hemorrhage due to aneurysmal rupture underwent cerebral blood flow (CBF) measurements before and after cisternal injection of papaverine hydrochloride. One patient showed prominent increases in CBF in the frontal lobe and basal ganglia after injection of papaverine, but paradoxical decreases in the parietal lobe and corona radiata. The other two patients had poor CBF response. Dense clotting in the basal cisterns may have prevented diffusion of the agent so that only the proximal trunks of the internal carotid, anterior cerebral, and middle cerebral arteries were dilated in the former case. The dilation of proximal trunks of cerebral arteries might steal blood flow from the parietal lobe and corona radiata, where the intraparenchymal arteries were maximally dilated and cerebrovascular reserve capacity was poor.

Adult↗
PubMed1997

Effect of glycerol on blood flow distribution in tumoral and peritumoral brain tissue.

The effect of glycerol on blood flow in tumoral and peritumoral tissue was measured in 32 patients with brain tumor, 17 gliomas and 15 meningiomas. Blood flow before and after the administration of glycerol was measured by stable xenon-enhanced computed tomography. The tumor part of glioma was significantly hypoperfused. In contrast, the tumor part of meningioma was significantly hyperperfused. Peritumoral edema of both glioma and meningioma was hypoperfused. After the administration of glycerol, blood flow increased in all regions except for the tumor part of glioma. Vascular responses to glycerol may be different in these two tumor types. The steal phenomena of blood flow might occur in cases of glioma.

Adolescent↗