Biomedical subjects

S Maekawa

Publications and source records attributed to S Maekawa.

At least 73 records · Page 4Linked to original sources

PubMed2000

Moderate hypothermia improves imbalances of thromboxane A2 and prostaglandin I2 production after traumatic brain injury in humans.

OBJECTIVE: To examine the levels of thromboxane B2 (TXB2) and 6-keto prostaglandin F1alpha (6-keto PGF1alpha) production in arterial and internal jugular bulb sera in patients with traumatic brain injury (TBI). TBI is associated with arachidonate release and may be associated with an imbalance of vasoconstricting and vasodilating cyclooxygenase metabolites. DESIGN: A prospective, randomized study. SETTING: The intensive care unit of a medical university hospital. INTERVENTIONS: Twenty-six ventilated TBI patents (Glasgow Coma Scale score on admission, < or = 8 points) were divided randomly into two groups: a hypothermic group (n = 15), in which the patients were cooled to 32 to 33 degrees C after being giving vecuronium, midazolam, and buprenorphine; and a normothermic group (n = 11), in which the patients' body temperature was controlled at 36 to 37 degrees C by surface cooling using the same treatment as the hypothermic group. Body temperature control including normothermia was started 3 to 4 hrs after injury. The duration of hypothermia usually lasted for 3 to 4 days, after which the patients were rewarmed at a rate of approximately 1 C per day. MEASUREMENTS AND MAIN RESULTS: Blood sampling for TXB2 and 6-keto PGF1alpha was started shortly after admission in both groups. Arterial TXB2 levels on admission in both groups were elevated remarkably, but not 6-keto PGF1alpha, thereby causing an imbalance of the prostanoids after injury. In the normothermic group, TXB2 decreased transiently, but this prostanoid increased again 3 days after the injury. In the hypothermic group, such prostanoid differences disappeared shortly after therapy, and the condition was sustained for 10 days. Hypothermia attenuated differences in TXB2 levels between arterial and internal jugular bulb sera, which may reflect reduced cerebral prostanoid production. The Glasgow Outcome Scale score 6 months after the insult in the hypothermic group was significantly higher than that in the normothermic group (p = .04). CONCLUSION: The current results from a limited number of patients suggest that moderate hypothermia may reduce prostanoid production after TBI, thereby attenuating an imbalance of thromboxane A2 and prostaglandin I2. However, it must be clarified whether the changes in the prostanoid after moderate hypothermia are a secondary effect of other mediator changes or whether they simply represent an epiphenomenon that is mechanistically unrelated to damage in TBI.

6-Ketoprostaglandin F1 alpha↗

PubMed2000

Ultrastructural and immunohistochemical findings in five patients with vitreomacular traction syndrome.

OBJECTIVE: To evaluate pathologic features of vitreomacular traction syndrome (VMT). METHODS: Preretinal membranes removed from five patients during vitreous surgery for VMT syndrome were evaluated by electron microscopy (n = 4) and immunohistochemistry (n = 1). RESULTS: Electron microscopic examination revealed large segments of internal limiting lamina (ILL) in three of the four cases. Other extracellular features included two types of abnormal collagen fibrils, determined to be type I and fibrous long-spacing collagen. The myofibrocyte was the predominant cell type in all cases. Collagen types I, II, and III, as well as glial fibrillary acidic protein and vimentin, were identified by immunohistochemistry. CONCLUSIONS: Epiretinal membranes in eyes with VMT syndrome adhered tightly to the ILL with abnormal collagen and contractile elements that included myofibrocytes.

Aged↗

PubMed2000

p53 gene mutations occurring in spontaneous benign and malignant mammary tumors of the dog.

Sixty-three cases of benign and malignant canine mammary tumors were analyzed to define the alteration of exons 5-8 for the p53 tumor suppressor gene using polymerase chain reaction direct sequence analysis with paraffin-embedded tissues. Four missense mutations were found in 38 benign mammary tumors (11%), and five missense (one tumor had two missense mutations) and one nonsense mutations were found in 25 mammary carcinomas (20%). These data suggest that the p53 gene alterations might be initiated at an early stage of canine mammary carcinogenesis and p53 mutations might be associated with malignancy. However, there was no evidence of any relationship between the p53 alterations and the histologic types of tumors or breeds of dogs.

Animals↗

PubMed2000

[Continuous intravesical instillation of epirubicin immediately after transurethral resection of superficial bladder cancer: a prospective controlled study].

Between November 1994 and July 1996, 45 patients with superficial bladder tumor were assigned to two groups before transurethral resection of bladder tumor. Twenty-one of the 45 patients were instilled with 20 mg epirubicin before endoscopic resection then continuously irrigated with 40 micrograms/ml epirubicin solution for 20 hours immediately after surgery; 24 of the 45 patients received continuous irrigation with saline in the same manner. The patients were assessed by cystoscopy and urinary cytology every 3 months during the first 2 years and every 6 months thereafter. One year recurrence-free rates in the treated and control groups were 56% and 32%, respectively. The recurrence-free period tended to be longer in the treated group than in the control group, although the difference was not significant (p = 0.17). One year recurrence-free rates in the treated and control groups for the patients with solitary tumor were 88% and 48%, respectively, the difference being marginally significant (p = 0.06). These results suggested that continuous bladder irrigation with epirubicin was effective for patients with a single tumor. Therefore, the long-term prophylactic therapy for a single tumor was an overtreatment. Prophylactic intravesical chemotherapy for superficial bladder cancer was proposed to be stratified by the number of tumors, single or multiple.

Administration, Intravesical↗

PubMed2000

[A case of bladder hemangioma showing bladder tamponade during late pregnancy].

We report a case of bladder hemangioma manifesting bladder tamponade during pregnancy. A 25-year-old woman at 36 weeks of gestation was admitted with a two-week history of gross hematuria and clot retention. Blood hemoglobin concentration was 6.3 g/dl. After blood transfusion and Caesarian section, cystoscopy was performed. Bleeding was noticed from a strawberry-like tumor 5 mm in diameter near the right ureteral orifice, which was easily resected endoscopically. Histopathological diagnosis was cavernous hemangioma of the urinary bladder. This is the first report of a case of bladder hemangioma during pregnancy.

Adult↗

PubMed2000

Impact of interventional therapy for benign prostatic hyperplasia on quality of life and sexual function: a prospective study.

PURPOSE: Treatment for benign prostatic hyperplasia (BPH), including minimally invasive therapy, can impair the quality of life. We prospectively determined the impact of 4 different interventional therapies on quality of life and sexual function. MATERIALS AND METHODS: A total of 173 patients were prospectively evaluated between February 1995 and August 1997. Treatment modalities consisted of standard transurethral resection of the prostate in 55 cases, transurethral microwave thermotherapy in 34, interstitial laser coagulation of the prostate in 42 and transurethral needle ablation in 42. Disease specific quality of life was assessed using the International Prostate Symptom Score quality of life assessment index and BPH impact index. In addition, a self-reporting questionnaire was completed before and 3 months after treatment to determine the impact on sexual function. RESULTS: All 4 treatment groups showed significant improvement in the symptom score, International Prostate Symptom Score quality of life assessment score and BPH impact index score. Satisfaction with treatment was highest in patients treated with transurethral resection or laser coagulation. A mild to moderate decrease in erectile function was noted in 26.5%, 18.2%, 18.4% and 20.0% of the transurethral resection, microwave thermotherapy, laser coagulation and needle ablation groups, respectively, but there was no significant difference of mean pretreatment and posttreatment erectile function or libido scores in any group. Ejaculation loss or severe decrease in ejaculate volume was reported by 48.6%, 28.1%, 21.6% and 24.3% of the patients, respectively. Interestingly, 20 of the 44 patients (45. 5%) with loss of ejaculation or severe decrease in ejaculate reported deterioration of the sex life, while only 2 (3.6%) of the 56 without any change in ejaculate volume reported such deterioration. The association of ejaculatory dysfunction with an adverse impact on sexual activity was highly significant (p <0.0001). CONCLUSIONS: Significant improvement in quality of life could be achieved with the present assessed interventional therapies. There was no significant change in sexual desire or erectile function with these therapies. Posttreatment sexual dysfunction appears to be mainly related to impaired ejaculatory function. Urologists should provide proper counseling regarding the possibility of this complication even in patients receiving minimally invasive treatment.

Aged↗

PubMed1999

Cholesterol-dependent localization of NAP-22 on a neuronal membrane microdomain (raft).

A membrane microdomain called raft has been under extensive study since the assembly of various signal-transducing molecules into this region has been envisaged. This domain is isolated as a low buoyant membrane fraction after the extraction with a nonionic detergent such as Triton X-100. The characteristic low density of this fraction is ascribed to the enrichment of several lipids including cholesterol. To clear the molecular mechanism of raft formation, several extraction methods were applied to solubilize raft components. Cholesterol extraction using methyl-beta-cyclodextrin was found to be effective to solubilize NAP-22, a neuron-enriched Ca(2+)-dependent calmodulin-binding protein as well as one of the main protein components of brain raft. Purified NAP-22 bound to the liposomes that were made from phosphatidylcholine and cholesterol. This binding was dependent on the amount of cholesterol in liposomes. Calmodulin inhibited this binding in a dose-dependent manner. These results suggest that the presence of a calcium-dependent regulatory mechanism works on the assembly of raft within the neuron.

Animals↗

PubMed1999

Immunohistochemical demonstration of a neuronal calmodulin-binding protein, NAP-22, in the rat spinal cord.

Neuron-enriched acidic protein having a molecular mass of 22 kDa, NAP-22, is a newly isolated calmodulin-binding protein and is phosphorylated with protein kinase C (PKC). This protein is localized to biological membrane via myristoylation and found in the membrane fraction of the brain and in the synaptic vesicle fraction. To reveal the NAP-22 distribution in vivo, we investigated the spinal cord of the 4-5-week old rats using light and electron microscopy. NAP-22 immunoreactivity was observed in the gray matter with dorsoventral gradient of reactivity. Distinct reactivity was demonstrated in the nerve terminals and dendritic spines. Some reactions were also observed in the thin nerve fibers. NAP-22 immunoreactivity was associated mainly with pre- and postsynaptic membranes, synaptic vesicles and outer mitochondrial membranes. In the nerve terminals, NAP-22 was colocalized with synaptic vesicle proteins such as synapsin I or synaptobrevin 2. About 80% of the nerve terminals having immunoreactivity for synapsin I or synaptobrevin 2 showed NAP-22 immunoreactivity. From these results, NAP-22 is confirmed to be distributed in the synaptic region of the spinal cord and is involved in the synaptic function relating to PKC.

Animals↗

PubMed1999

Characterization of a novel rat brain glycosylphosphatidylinositol-anchored protein (Kilon), a member of the IgLON cell adhesion molecule family.

In the central nervous system, many cell adhesion molecules are known to participate in the establishment and remodeling of the neural circuit. Some of the cell adhesion molecules are known to be anchored to the membrane by the glycosylphosphatidylinositol (GPI) inserted to their C termini, and many GPI-anchored proteins are known to be localized in a Triton-insoluble membrane fraction of low density or so-called "raft." In this study, we surveyed the GPI-anchored proteins in the Triton-insoluble low density fraction from 2-week-old rat brain by solubilization with phosphatidylinositol-specific phospholipase C. By Western blotting and partial peptide sequencing after the deglycosylation with peptide N-glycosidase F, the presence of Thy-1, F3/contactin, and T-cadherin was shown. In addition, one of the major proteins, having an apparent molecular mass of 36 kDa after the peptide N-glycosidase F digestion, was found to be a novel protein. The result of cDNA cloning showed that the protein is an immunoglobulin superfamily member with three C2 domains and has six putative glycosylation sites. Since this protein shows high sequence similarity to IgLON family members including LAMP, OBCAM, neurotrimin, CEPU-1, AvGP50, and GP55, we termed this protein Kilon (a kindred of IgLON). Kilon-specific monoclonal antibodies were produced, and Western blotting analysis showed that expression of Kilon is restricted to brain, and Kilon has an apparent molecular mass of 46 kDa in SDS-polyacrylamide gel electrophoresis in its expressed form. In brain, the expression of Kilon is already detected in E16 stage, and its level gradually increases during development. Kilon immunostaining was observed in the cerebral cortex and hippocampus, in which the strongly stained puncta were observed on dendrites and soma of pyramidal neurons.

Amidohydrolases↗

PubMed1999

Quality of life following surgery for vertebral metastases from breast cancer.

BACKGROUND AND OBJECTIVES: The quality of life of patients with vertebral metastases from breast cancer treated with surgery was evaluated. METHODS: Seven such patients underwent surgery for vertebral metastases following chemoendocrine treatment. They presented with pain and some with neurological compromise. RESULTS: Following posterior stabilization with a segmental instrument, pain was alleviated in all seven women, two showed improvements in neurological compromise, and performance status was improved in five. In no patient was there neurological deterioration secondary to surgical intervention. They were out of bed on the 4th postoperative day and discharged on the 14th day on average. CONCLUSIONS: The quality of life was improved for these surgically treated patients. We recommend surgical stabilization for selected patients with a vertebral metastasis from breast cancer.

Adult↗

PubMed1999

The effectiveness of chemotherapy with cisplatin and 5-fluorouracil for recurrent small cell neuroendocrine carcinoma of the rectum: report of a case.

We report herein the case of a 46-year-old-man with small cell neuroendocrine carcinoma (NEC) concomitant with large villous adenoma of the rectum, who underwent abdominoperineal resection with regional lymphnode dissection. The resected specimen was histologically found to contain a small lesion of NEC confined to the submucosa in the large adenoma. A computed tomography scan done 4 months postoperatively revealed recurrences in the liver, lymph nodes, and bone. Therefore, two cycles of sequential intravenous combined chemotherapy with standard doses of cisplatin and 5-fluorouracil (5-FU) were administered, after which the size of each tumor decreased remarkably. Nevertheless, the patient died 8 months after the operation. As there was a fair response of this tumor to the combined chemotherapy of cisplatin and 5-FU, this regimen against NEC of the colon and rectum should be given consideration.

Adenoma, Villous↗

PubMed1999

Complexed prostate-specific antigen and its volume indexes in the detection of prostate cancer.

OBJECTIVES: To evaluate complexed prostate-specific antigen (cPSA), cPSA density (cPSAD), and cPSA adjusted for the transition zone volume (cPSA-TZ) in comparison with the free-to-total PSA ratio (F/T PSA) and free-to-complexed PSA ratio (F/C PSA) as a means of diagnosing prostate cancer. METHODS: Transition zone volume was determined in 137 of 142 men who underwent systematic sextant biopsies and had total PSA (tPSA) values between 4.1 and 10.0 ng/mL. cPSAD and cPSA-TZ were calculated by dividing the cPSA value by the whole prostate volume and the transition zone volume, respectively. RESULTS: Of the 137 men, 23 (16.8%) had prostate cancer. cPSA predicted the biopsy outcome better than tPSA, F/T PSA, or F/C PSA, although the difference was not significant. A cutoff value of 4.1 ng/mL for cPSA provided a specificity of 42% and a sensitivity of 87%. A combination of cPSA and F/C PSA maintained a sensitivity of 83% and gave an increased specificity of 54%. In a subgroup of 65 patients with smaller prostate volumes (less than 45 mL), the diagnostic value of cPSA-TZ was remarkably increased. A cutoff value of 0.31 for cPSA-TZ provided a sensitivity of 93% and a high specificity of 72%. CONCLUSIONS: cPSA was more specific than tPSA and F/T PSA. As a component of F/C PSA, free PSA could provide additional value to cPSA. cPSA-TZ and cPSAD could be better indicators for prostate cancer than cPSA.

Aged↗

PubMed1999

Activated cytokine production in patients with accidental hypothermia.

We have demonstrated recently that therapeutic moderate hypothermia of 32-33 degrees C, induced by surface cooling under the administration of narcotics, sedatives and muscle relaxant, suppresses cytokine production after traumatic brain injury. We present here the first documented case report of augmented cytokine production in two accidental hypothermia patients, unconscious 84- (acute immersion) and 87- (non-immersion) year-old women, whose rectal temperatures were below 28 degrees C. The victims were artificially ventilated after sedation with midazolam and buprenorphine in accordance with our protocol. Rewarming at the rate of approximately 1 degrees C/h was done by blowing forced-air with appropriate fluid resuscitation. Plasma interleukin(IL)-6 and/or IL-8 levels were measured using ELISA in the patients. In both patients, plasma IL-6 levels on admission were already elevated and the cytokine levels further increased during and after the rewarming period. In the patient with the poorer prognosis, the plasma IL-8 level on admission was not elevated remarkably but after rewarming the level rose significantly. Augmented IL-6 production in accidental hypothermia was sustained for 6 days in the patient with the poorer prognosis but not in the subject with good recovery, who was treated with anti-thrombin III in the early phase. Since the mechanisms for developing accidental hypothermia were different, simple comparisons between the two cases should be limited. But, these findings may suggest a need for testing a hypothesis whether cytokine modulation could be a therapeutic approach worthy of consideration. The results presented here also suggest that in hypothermia, changes in cytokine release may vary depending on procedures such as the anesthetic drugs used, the duration of the therapy, or the rate of rewarming from hypothermia.

Aged↗

PubMed1999

Immunohistochemical localization of a novel acidic calmodulin-binding protein, NAP-22, in the rat brain.

NAP-22 is a neuronal tissue-enriched acidic calmodulin-binding protein with a molecular mass of 22,000 and is recovered in the membrane fraction during biochemical fractionation. We observed the distribution pattern of this protein in the rat brain using an immunohistochemical method by light and electron microscopy. NAP-22 immunoreactivity was detected through the whole brain, and the most dense staining was observed in the forebrain including cerebral cortex, hippocampal formation, olfactory bulb, basal ganglia and thalamus. Immunoreactivity was distributed densely at the neuropil, whereas nerve cells and nerve fibres had little or no reaction. In the brain stem, immunonegative large nerve cell bodies were surrounded by immunopositive varicosities. In the cerebellar cortex, mossy fibre terminals and parallel fibres showed immunoreactivity, whereas Purkinje cells did not. Intracellular distribution was observed in the cerebral and cerebellar cortices. NAP-22 immunoreactivity was noted in the axon terminals, dendritic spines and thin nerve fibres. In these structures, reaction products were associated mainly with synaptic vesicles, pre- and postsynaptic membranes and microtubules. This study demonstrates that the immunoreactivity of NAP-22 is distributed widely in the brain, especially in the synapse, and suggests that this protein is involved in synaptic transmission both in the pre- and postsynaptic region.

Animals↗

PubMed1999

Oxidative stress and haematological changes in immobilized rats.

Immobilization stress induces formation of reactive oxygen species (ROS) and leads to the oxidative injury in various tissues. In this study, the effects of immobilization stress on peripheral blood cells distribution, plasma level of thiobarbituric acid reactive substances (TBARS), and activities of antioxidant enzymes in erythrocytes were investigated in male Fischer rats. A significant increase in plasma TBARS was observed during and after the stress. Dramatic increases of neutrophils and monocytes imply that ROS formation resulted from their activation. Furthermore, the antioxidant activities of catalase and superoxide dismutase (SOD) in erythrocytes were dramatically increased during and after the stress, while a large fall in erythrocyte number was observed. These findings suggest that the activation of immune cells can be a source of the immobilization-induced ROS production, and that antioxidant enzymes in erythrocytes play an important role in preventing the ROS-induced injuries.

Animals↗

PubMed1999

Changes in resistive index following extracorporeal shock wave lithotripsy.

BACKGROUND: Extracorporeal shock wave lithotripsy (ESWL) has replaced most surgical and endourologic forms of therapy for upper urinary tract stone disease. Despite its proved safety and efficacy, its adverse effects on renal function are still to be identified. A newer diagnostic technique, color Doppler ultrasonography, has brought a new insight into renal function. It enables precise evaluation of the renal vascular supply. Changes in intrarenal vascular resistance after ESWL were studied with Doppler ultrasound techniques. METHODS: In 70 consecutive patients the resistive index (RI) was measured at an interlober artery before and 30 min after ESWL in the treated and contralateral kidneys. In 17 patients, a follow-up Doppler study was performed 1 week after ESWL. RESULTS: In the treated kidneys, the RI significantly increased from 0.656+/-0.053 (mean +/- SD) at baseline to 0.682+/-0.053 (P<0.0001). There was no significant correlation of increase in RI with patient age (r = 0.010) or with pre-ESWL blood pressure (r = 0.002). Elderly patients (> or =60 years old, n = 31) had higher RI levels on baseline than younger patients (<60 years old, n = 39). In 18 of the 31 (58.1%) elderly cases the RI were elevated to greater than 0.7, indicating pathologic changes. In younger patients, only 9 (23.1%) experienced increase in RI up to 0.7 or greater. The contralateral untreated kidneys showed significant change in RI before (0.664+/-0.045) and after (0.679+/-0.049) lithotripsy in elderly patients (P<0.005). A follow-up Doppler study showed that the mean RI returned to pretreatment levels after 1 week. CONCLUSIONS: Because of higher RI levels on baseline, elderly patients have a higher risk of post-ESWL renal tissue damage than younger patients. Clinical implication of RI change in the contralateral kidneys in this study remains to be answered. The measurement of changes in RI with Doppler ultrasound techniques after ESWL may provide useful information for clinical diagnosis of renal tissue damage.

Adolescent↗

PubMed1999

Urinary undiversion for pelvic actinomycosis: a long-term follow up.

BACKGROUND: A 43-year-old woman who had been using intrauterine contraceptive devices for the past 10 years underwent an emergency operation for bowel and urinary obstruction. METHODS/RESULTS: Frozen section analysis showed undifferentiated adenocarcinoma. Incomplete tumorectomy, ileal resection, partial cystectomy, colostomy and bilateral ureterocutaneostomy were palliatively performed. Postoperatively, periodic acid-Schiff and Grocott-Gomori methenamine tests revealed Actinomyces and the final diagnosis was pelvic actinomycosis. Treatment with penicillin G administered intravenously relieved her symptoms and the lesion was dramatically improved. The patient underwent colostomy closure and urinary undiversion. CONCLUSIONS: Five years after urinary undiversion, the patient's renal function has been maintained and she can void without incontinence and dysuria.

Actinomycosis↗

PubMed1999

Patient-reported quality of life after radical prostatectomy for prostate cancer.

BACKGROUND: Increasingly, quality of life (QOL) assessments are receiving greater attention in the management of malignancies, including prostate cancer. We evaluated the impact of radical prostatectomy on patient QOL 12 months or longer after surgery. PATIENTS AND METHODS: We evaluated the impact of radical prostatectomy on QOL in 60 patients with prostate cancer. The patients comprised two groups: the first group (n = 32) was evaluated 12 months or longer after radical prostatectomy; the second group (n = 28) was evaluated while awaiting radical prostatectomy. General health-related QOL was measured with the European Organization for Research and Treatment of Cancer Prostate Cancer QOL Questionnaire. Sexual function was assessed with the Sapporo Medical University Sexual Function Questionnaire. A newly developed instrument assessing urinary function was prepared only for the postoperative group. RESULTS: No differences between the two groups were seen in comparisons of general health-related QOL subscales. Men who underwent surgery reported significant deterioration in sexual function (decreased quality of erection, decreased sexual activity and decreased satisfaction with sex life) than those awaiting surgery. Of the 32 postoperative patients, 26 (81%) did not use pads at all, five (16%) used one or fewer pads per day due to occasional spotting and only one patient (3%) used two to four pads per day to deal with urine dripping. Twenty-six postoperative patients (81%) stated that, given the choice, they would undergo radical prostatectomy again. CONCLUSIONS: General health-related QOL does not appear to be compromised following radical prostatectomy. Patients are willing to accept some morbidity for a perceived survival benefit. Although minimal urinary dysfunction was reported, most patients were dissatisfied with postoperative sexual function. In preoperative counselling, greater emphasis should be placed on the risk of postoperative impotence.

Aged↗