Biomedical subjects

T Sayama

Publications and source records attributed to T Sayama.

At least 19 recordsLinked to original sources

PubMed2005

Intraarterial injection of colforsin daropate hydrochloride for the treatment of vasospasm after aneurysmal subarachnoid hemorrhage: preliminary report of two cases.

We describe two patients with symptomatic vasospasms after aneurysmal subarachnoid hemorrhage who were successfully treated with intraarterial injection of colforsin daropate hydrochloride (HCl). Colforsin daropate HCl is capable of directly stimulating adenylate cyclase, which in turn causes vasorelaxation via elevated intracellular concentrations of cyclic adenosine monophosphate. We suggest that colforsin daropate HCl might be a useful therapeutic tool in treating cerebral vasospasm.

Cerebral Angiography↗

PubMed2004

Angiographic, hemodynamic and histological characterization of an arteriovenous fistula in rats.

BACKGROUND: Our understanding of the pathogenesis of arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs) has been limited by the lack of adequate animal models. In this study we evaluate the time course of angiographic, hemodynamic and histopathological changes in an arteriovenous fistula in rats as a potential model. METHODS: An arteriovenous fistula was created by a side-to-end anastomosis of the common carotid artery (CCA) to the external jugular vein (EJV). The animals underwent angiography of the fistula and were sacrificed 1, 7, 21, 42 or 90 days later. Flow and pressure measurements were performed in the CCA and ipsi- and contralateral EJV and detailed histological examination of whole mount sections of the fistula and cranium were done on fixed sections. Immunohistochemistry for CD31, smooth muscle alpha-actin and Ki-67 were performed. FINDINGS: Hemodynamic changes occur immediately after fistula formation creating a stable high flow, low resistant state. This induces a gradual increase in the inner diameter of the EJV and transverse sinus followed by a decrease in size of the transverse sinus. This decrease is associated with increased expression of alpha-actin in the wall of the sinus. The fistula becomes angiographically and histologically stable after 21 days. CONCLUSION: This model describes the time course of hemodynamic and histopathological changes after occur after AVF formation. Stabilization after 21 days makes it an attractive model for mechanistic and therapeutic studies of AVFs.

Animals↗

PubMed2003

Three-dimensional CT angiography for the surgical management of the vertebral artery-posterior inferior cerebellar artery aneurysms.

BACKGROUND: Surgery of vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysms is not easy because there is a close anatomical relationship between aneurysms and the surrounding neurovascular structures, and bony structures in the lateral foramen magnum. The preoperative evaluation for a circumstantial comprehension of anatomical relationships is very important for the surgical treatment of the VA-PICA aneurysms. Our experience in using three-dimensional CT angiography (3D-CTA) for the surgical management of VA-PICA aneurysms is herein reported. METHODS AND FINDINGS: We successfully performed neck clipping in 5 cases of VA-PICA aneurysm using 3D-CTA. On 3D reconstructed images, we could see the characteristics of the aneurysms such as their relationships to the jugular tubercle and hypoglossal canal, the projecting direction of the dome, and the configuration of the neck in each case. 3D-CTA also provided a clear surgical view as well as the relationships of the aneurysms to the VA and origin of the PICA. Based on such information, we selected the most appropriate surgical approach among the transcondylar fossa approach, the transcondylar approach, or the far lateral approach with a C1 laminectomy. CONCLUSIONS: Since 3D-CTA demonstrates the surgical anatomy of VA-PICA aneurysms in detail, it is very useful for helping surgeons to select the optimal approach.

Adult↗

PubMed2001

[The significance of early detection for prostate cancer in mass screening].

PURPOSE: In Mitaka city, mass screening for prostate cancer was conducted for 3 years from 1995 to 1997. Clinical stages were compared between patients found by screening and those diagnosed at our clinic during the same time. The significance of serum-free prostate specific antigen (PSA) in mass screening for prostate cancer was examined. MATERIAL AND METHODS: A prospective clinical trial was conducted on men aged 50 years or older. The primary examination consisted of taking the international prostate symptom score, quality of life score, PSA (Tandem-R) and digital rectal examination (DRE). If PSA was greater than 4.0 ng./ml and/or if DRE suggested cancer, transrectal ultrasound-guided sextant prostate biopsies were indicated. RESULTS: Of the men screened, 23.2% (320/1375) had serum PSA greater than 4.0 ng./ml. and/or suspicious findings on DRE. Biopsy was performed in 199 of 320 (62.1%). Cancer was detected in 21 (1.5%, 21/1375). Prostate cancer was found in one case among 154 males (0.65%, 1/154) who were screened twice or more. The cancer stage found by screening was significantly earlier than that diagnosed at the outpatient clinic (Wilcoxon's rank-sum test: p = 0.0047). Receiver operating characteristics analysis showed that the optimal free PSA-to-PSA ratio was 12%. Positive predictive value increased from 18% to 50% when free PSA-to-PSA ratio was combined with PSA. CONCLUSION: 1. Cancer detection rate was 1.5% in the mass screening in Mitaka City. 2. Cancer stage found by screening was significantly earlier than that diagnosed at the outpatient clinic. 3. Free PSA determination might eliminate unnecessary biopsies in men with PSA above 4.0 ng./ml with minimal loss of cancer detection.

Aged↗

PubMed2001

[Comparisons of factors affecting voiding disorders between patients with benign prostate hyperplasia and volunteers].

PURPOSE: The prostate size and motivation to visit clinics were investigated in patients with prostate hyperplasia. OBJECTS AND METHODS: One hundred ninety-five patients who had urinary symptoms and visited our outpatient clinic between September 1994 and October 1999 and 268 age-matched volunteers in Mitaka City who underwent a medical examination of the prostate in June 1997 were compared. International Prostate Symptom Score (IPSS), Quality Of Life Score (QOL score), residual urine volume, prostate volume and urinary flow rate were measured. RESULTS: The prostate volume of the volunteers was 20-25 cm3 irrespective of the age. The prostate size of the outpatients was larger than that of the volunteers for every age group. IPSS and QOL score were significantly higher in the outpatients than in the volunteers. Diurnal urinary frequency and sense of residual urine contributed to the discrimination index of the two groups more significantly than the other scores. There was a significant correlation between prostate volume and residual urine volume. The score of weak urinary steam was inversely and significantly correlated with peak urinary flow rate. CONCLUSIONS: There was no age-related enlargement of the prostate gland. The prostate gland was significantly larger in the patients than in the volunteers even in those in their fifties. Urinary frequency and sense of residual urine are important factors for men to seek and receive medical care.

Adult↗

PubMed2000

Normal diffusion-weighted imaging in cerebral air embolism complicating angiography.

We report a case of cerebral air embolism resulting from accidental air infection during cerebral angiography. A 60-year-old man was accidentally injected with air via the left subclavian artery. Angiography demonstrated air within the basilar artery. The patient showed signs of posterior circulation ischaemia (confusion, blindness, gaze palsy and hemiparesis). However, MRI, including diffusion-weighted imaging, showed no abnormality 4 h later. The patient was treated with hyperbaric oxygen within 5 h of the embolism. All symptoms and signs resolved completely within a week.

Brain↗

PubMed2000

High incidence of hyponatremia in patients with ruptured anterior communicating artery aneurysms.

We studied the incidence and timing of hyponatremia (Na < 135 mEq l-1) after subarachnoid hemorrhage (SAH) with special reference to ruptured anterior communicating artery (A-com) aneurysms. Hunt and Kosnik (HK) grading, symptomatic vasospasm in A-com aneurysm, and hydrocephalus were analyzed for connections to hyponatremia in 55 patients with ruptured A-com aneurysms, 65 with ruptured internal cerebral artery (ICA) aneurysms, and 49 with ruptured middle cerebral artery (MCA) aneurysms. Hyponatremia occurred in 28 (51%) of 55 patients with A-com aneurysms and in nine (18%) of 49 patients with MCA aneurysms. Severe hyponatremia (Na < 130 mEq l-1) occurred in 16 patients (29%) in the A-com group, four patients (6%) in the ICA group, and three patients (6%) in the MCA group. The A-com aneurysm group had a significantly higher incidence of mild hyponatremia (p < 0.01) and severe hyponatremia (p < 0.001) than other groups. Among A-com cases, hyponatremia occurred significantly more often in HK grade III and IV cases (p < 0.05), in cases with vasospasm (p < 0.001), and in cases with hydrocephalus (p < 0.01). Respective days of onset for symptomatic vasospasm and for hyponatremia were day 7.6 +/- 4.4 and day 10.6 +/- 5.8 following SAH, representing a 3-day delay for hyponatremia (p < 0.05). In most patients hyponatremia resolved within 28 days following SAH. Hyponatremia occurred more often with A-com aneurysms, possibly because of vasospasm around the A-com or hydrocephalus causing hypothalamic dysfunction. Since hypervolemic therapy can cause hyponatremia, particularly careful observation is required during such therapy in patients with A-com aneurysm.

Aneurysm, Ruptured↗

PubMed2000

[Relationship between cardiac natriuretic peptide (ANP/BNP) and fluid intake in patients with subarachnoid hemorrhage].

Several authors described elevated natriuretic peptides, atrial natriuretic peptide(ANP) and brain natriuretic peptide (BNP), in patients with subarachnoid hemorrhage(SAH), which were account for inappropriate antidiuretic hormone(SIADH) or cerebral salt wasting syndrome(CSW). Although the secretion of natriuretic peptide depends on the total blood volume, central venous pressure, and cardiac output volume, the volume of fluid intake in patients with SAH had not been taken in consideration in previous report. We here examined the relationship between fluid intake and the natriuretic peptides in two cases without cardiac failure. ANP elevated 2 or 3 days after SAH and remained in normal range for 2 weeks. BNP elevated when the volume of fluid intake was increased, and BNP did not elevate during the periods with lower fluid intake. Several authors proposed the possibility of iatrogenic factor in natriuresis after SAH and these results supported this opinion.

Adult↗

PubMed1999

Lung adenocarcinoma in lymphocytic interstitial pneumonitis associated with primary Sjögren's syndrome.

We experienced a rare case of lung adenocarcinoma associated with lymphocytic interstitial pneumonitis caused by primary Sjögren's syndrome. A 78-year-old woman was referred to our hospital because of progressive sicca syndrome and nodular opacities in the right lower lobe on chest radiograph. This patient was diagnosed as primary Sjögren's syndrome by a labial gland biopsy and classical clinical features including xerophthalmia, xerostomia and immunoserological findings. Pathological findings including immunohistochemical studies in a surgically resected lung revealed adenocarcinoma in lymphocytic interstitial pneumonitis associated with primary Sjögren's syndrome. There was no evidence of malignant lymphoma in the lymph nodes or resected lung tissue. Pulmonary involvement of Sjögren's syndrome is now regarded both clinically and histopathologically as a wide spectrum of lymphoproliferative disorders ranging from benign to malignant. However, lung cancer associated with primary Sjögren's syndrome, as in our case, has apparently not been reported previously.

Adenocarcinoma, Papillary↗

PubMed1999

Role of inducible nitric oxide synthase in the cerebral vasospasm after subarachnoid hemorrhage in rats.

The involvement of de novo nitric oxide synthase (NOS) induction in the development of cerebral vasospasm after subarachnoid hemorrhage (SAH) was examined using a rat model of SAH. SAH was induced by endovascular perforation with Nylon thread. The rats were killed at different time intervals, from one day to seven days after endovascular perforation. Inducible NOS messenger RNA (mRNA) expression was determined by reverse-transcription polymerase chain reaction (RT-PCR) and the distribution of iNOS positive cells was immunohistochemically examined. In the vascular tissue with a subarachnoid membrane, iNOS mRNA was expressed from one day to seven days after SAH. Inducible NOS positive cells were mainly recognized in the vascular tissue, but not in the brain parenchyma. The distribution of nitrotyrosine, an indicator of peroxynitrite production was also examined immunohistochemically and nitrotyrosine-positive cells were observed almost at the same sites of iNOS induction. To determine the role of iNOS in the development of cerebral vasospasm, we measured the diameter of the middle cerebral artery in animals either treated or not treated with aminoguanidine (AG), a selective inhibitor of iNOS. AG ameliorated the vasoconstrictive change after SAH. These results are thus considered to provide molecular and immunohistochemical evidence showing that iNOS expression following SAH and NO produced by iNOS can develop cerebral vasospasm after SAH.

Animals↗

PubMed1999

Effect of intracarotid bradykinin infusion on cerebral blood flow in dogs.

We examined whether intracarotid infusion of bradykinin altered circulation in the normal canine brain. Twenty-four anesthetized dogs were divided into four groups receiving different doses of bradykinin (1, 2.5, 5, and 10 micrograms kg-1 min-1). Regional cerebral blood flow (rCBF) was measured continuously using laser Doppler flowmetry through a burr hole in the frontal bone. Systemic blood pressure (SBP) and heart rate (HR) were monitored simultaneously. Higher doses of bradykinin significantly but temporarily decreased rCBF and SBP immediately after the start of infusion; these parameters rapidly recovered and then were stable through the rest of the infusion. During this period, percent change in rCBF and SBP was small, and differences between groups were not significant. On the other hand, HR increased during infusion and remained high. SBP, rCBF, and HR returned to pre-infusion levels after bradykinin was stopped. The results suggest that intracarotid infusion of bradykinin for treatment of brain tumors would be safe in terms of circulation to the uninvolved brain.

Animals↗

PubMed1998

Expression of inducible nitric oxide synthase in rats following subarachnoid hemorrhage.

The possible expression of the inducible isoform of nitric oxide synthase (iNOS) was examined in a rat model of subarachnoid hemorrhage (SAH). Subarachnoid hemorrhage was induced by the injection of autologous blood into the cisterna magna using stereotactic technique under general anesthesia. The rats were then killed at specific time intervals between 4 hours to 7 days after SAH. Reverse-transcriptional polymerase chain reaction (RT-PCR) revealed the expression of iNOS mRNA in the homogenate obtained from the tissue around the circle of Willis one day after SAH (Day 1). No iNOS mRNA was detected either in the sham-operated animals, or at any of the other time intervals after SAH. An immunohistochemical study was performed to examine the localization of iNOS-positive cells in the central nervous system. Inducible NOS immunoreactivity was thus observed in the mononuclear cells and polymorphonuclear cells infiltrating into the subarachnoid space of the basal cistern on Day 1. This immunoreactivity persisted faintly on Day 2, but had completely disappeared on Day 7. A vascular diameter study disclosed a vasoconstrictive change in the middle cerebral artery after SAH. Taken together, these results are thus considered to confirm the expression of iNOS in the infiltrated inflammatory cells after the insult of SAH, which may therefore play an introductory role in the development of the pathological series of events after SAH, including vasospasm.

Animals↗

PubMed1998

[Relationship between maximum walking distance and frequency of outings in patients receiving home oxygen therapy].

We studied relationships between maximal walking distance (WDmax) and frequency of both outing enumerated by the aim of each outing as well as by each outing per se in patients receiving home oxygen therapy (n = 109). The results were compared with those from members of a seniors' club (n = 434). A questionnaire was used to obtain WDmax, defined as the distance a subject could walk without rest on level ground. In the questionnaire, WDmax was classified into five groups including 50 m (the distance between two electric posts), 500 m, 1 km, 1.5 km and more than 1.5 km. Since few patients could walk 1.5 km or more, they were included into the "can walk 1 km or more group". Outing frequency was measured using a 4-week diary which showed eight aims of outings including shopping, seeing a doctor, visiting friends or relatives, doing a hobby practicing something, participating in a seniors' club and neighborhood meetings or events, traveling, work and others. The subjects checked the diary each time they went out. True outing frequency was defined as the number of outings. If a subject left home to shop and visited a friend on the way home, the outing frequency enumerated by aims was two, while the true outing frequency was one. The mean and SE (1/4 weeks/one subject) of true outing frequency for patients (21.4 +/- 2.2) was significantly less than that of seniors' club members (45.6 +/- 1.4). Even in patients with a WDmax of 1 km or more, the frequency of travel was significantly lower than in seniors' club members. Although outing frequencies for shopping, seeing friends or relatives, doing a hobby and work were not significantly different between the two groups at a WDmax of 1 km or more, the outing frequency for work of patients was significantly lower at a WDmax of 500 m, and outing frequencies for the remaining three aims became significantly lower at a WDmax of 50 m. We demonstrated that in patients receiving home oxygen therapy, outing frequency was limited. A new modality is necessary to increase the outing frequency and to improve the quality of life for these patients.

Aged↗

PubMed1997

[The family function of patients on home oxygen therapy and their main caregivers].

We examined family APGAR scores in patients on home oxygen therapy (n = 101) and their main caregivers (n = 91), and compared them with those obtained from members of a seniors' club who were not on home oxygen therapy themselves, nor had any family members on home oxygen therapy. Furthermore, the relationship between the main caregivers recognition of the patients' mental state and the patients' CESD score was examined. Family APGAR scores for the main caregivers were significantly lower than those of the patients (p < 0.002), or the seniors' club members (p < 0.004). Since most the main caregivers were women, we compared family APGAR scores of the female main caregivers and the age-matched female members of the seniors' club, revealing that the satisfaction of the female main caregivers with the "adaptation" component of the APGAR score (the component dealing with support given when something troublesome happens), was significantly lower than that of the members of the seniors' club (p < 0.0001). The CESD of the patients whom the main caregivers recognized as depressed was significantly higher. Thus, we concluded that satisfaction of the main caregivers with family function who were family members was low, and that the role of the main caregivers is important in alleviating the depression of patients on home oxygen therapy.

Aged↗

PubMed1996

[Bucillamin induced lung injury in rheumatoid arthritis].

Thirteen cases with rheumatoid arthritis who experienced lung injury during the treatment with bucillamine (Bc), about whom the questionnaires were answered by the physicians and whose X-ray films could be rechecked, were studied. Nine cases out of the 13 showed patchy mottled infiltrates in the bilateral center sparing the periphery, and the other 4 showed diffuse infiltrates. In these 9, serum gamma-globulin level decreased when lung injury appeared. The gamma-globulin level before the start of Bc administration, the level when lung injury appeared, the gamma-globulin decrease, and its ratio to the level before Bc were 1790 +/- 661 mg/dl, 1297 +/- 666 mg/dl, 459 +/- 320 mg/dl and 29.1 +/- 18.0%, respectively. In 5 out of the 9, gamma-globulin level reincreased when they recovered from the injury: 2 out of the 5 showed the reincrease even after steroid therapy. The data were obtained only from 2 out of the 4 with diffuse pattern in X-ray, and the decrease and the decrease ratio were 200 mg/dl (5.8%) in 1, and 49 mg/dl (3.6%) in the other. The characteristics of Bc-induced lung injury might be mottled infiltrates in the center appearing concurrently with serum immunoglobulin decrease.

Aged↗

PubMed1995

Cranial fasciitis with massive intracranial extension.

The case of a 10-month-old boy with cranial fasciitis is described. The patient had a rapidly growing subcutaneous mass in the left frontotemporal region. Computed tomography and magnetic resonance imaging clearly demonstrated a mass in the left temporoparietal bone extending both intra- and extracranially. The tumor seemed to originate from the calvarium, being located between the periosteum and the dura mater. Total resection of the tumor was performed, and the tumor was histologically identified as cranial fasciitis. A brief review of the literature is included that emphasizes the need for further investigation of this benign lesion that is frequently confused with a malignant neoplasm.

Brain Diseases↗

PubMed1995

[A case of posterior fossa hypertrophic pachymeningitis with hydrocephalus].

A 52-year-old woman was admitted to our hospital because of nausea, headache, ataxic gait, and memory disturbance. CT scans and MRI showed a markedly enhanced lesion in the dura mater of the posterior fossa, edema in the right cerebellar hemisphere, occlusion of the transverse sinus, and hydrocephalus, suggesting hypertrophic pachymeningitis. Chronic otitis media and mastoiditis were also noted. Subjective complaints diminished after steroid administration. The patient underwent right suboccipital craniectomy and biopsy. The dura mater was markedly thickened, and the cerebellar surface was edematous. Histological examination revealed the thickened dura mater to be infiltrated by chronic inflammatory cells of forming lymphatic follicles and accompanied by Langhans giant cells. Inflammatory cells were not found in the cerebellar parenchyma, but were present in the subarachnoid space. Acid-fast stain, PAS and Grocott stain were negative. The cause of the hypertrophic pachymeningitis in this patient, may have been related to the chronic otitis media, but the patient's clinical course suggested that it might represent so-called "idiopathic hypertrophic pachymeningitis".

Cranial Fossa, Posterior↗

PubMed1995

[A case of necrotizing sarcoid granulomatosis diagnosed by open lung biopsy].

A 59-year-old man had an abnormal shadow on chest X-ray film. He was admitted to Tohoku-chuou Hospital, and a lung lesion in the right lower lobe was diagnosed as a benign nodule. A new nodular lesion appeared on a chest X-ray film taken two months after his discharge from the hospital. Both lesions were in the same lobe; the older one was in segment 9 and the newer one was in segment 10. For the lesion in segment 10, malignancy was not ruled out, so open lung biopsy (right lower lobectomy) was done. With the findings of angitis and focal necrosis surrounded by granulomas consisting of epthelioid cells and multinuclear giant cells, the new lesion in segment 10 was diagnosed as necrotizing sarcoid granulomatosis. The older lesion in segment 9 was a tuberculoma. We conclude that in this case the open lung biopsy was necessary to diagnose necrotizing sarcoid granulomatosis in lung.

Diagnosis, Differential↗