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Biomedical subjects

H Imamura

Publications and source records attributed to H Imamura.

At least 73 records · Page 4Linked to original sources
PubMed2001

Biventricular hypertrophic cardiomyopathy with right ventricular outflow tract obstruction associated with Noonan syndrome in an adult.

This report describes an adult patient with Noonan syndrome accompanied by biventricular hypertrophic cardiomyopathy causing isolated right ventricular outflow tract obstruction. Biventricular hypertrophic cardiomyopathy causing right- and/or left-side outflow tract obstruction, as well as valvular pulmonary stenosis, is relatively common in infants with Noonan syndrome. However, this condition without a dysplastic pulmonary valve, or indeed any polyvalvular dysplasia, is rare in adults with Noonan syndrome. Treatment with a beta-adrenergic receptor blocking agent improved the patient's symptoms. Because neither the etiologic and prognostic relationship nor the genetic linkage between hypertrophic cardiomyopathy associated with Noonan syndrome and non-syndromic hypertrophic cardiomyopathy is clearly defined, clinicopathological findings and further follow-up may provide important evidence for the pathogenesis of hypertrophic cardiomyopathy.

Adult↗
PubMed2001

Effects of bisphenol A and its derivatives on the response of GABA(A) receptors expressed in Xenopus oocytes.

To study the effects of bisphenol-A (BPA) known to have estrogenic actions, and its derivatives, 3,5-dimethylphenol (DMP) and p-t-butylphenol (TBP), on ionotropic gamma-aminobutyric acid (GABA) receptors, GABA(A) receptors were expressed in Xenopus oocytes by injecting both poly(A)+ RNA prepared from rat whole brain and cRNAs synthesized from cloned cDNAs of alpha1 and beta1 subunit of the bovine receptors, and their electrical responses were measured by the voltage clamping method. BPA caused the potentiation and inhibition of the former receptor-responses, while it caused only inhibition of the latter ones. In the presence of low concentrations of GABA, DMP and TBP potentiated the responses of both receptors. DMP and TBP also increased the rate of decay of the response, possibly by desensitization of the receptors when GABA solution was continuously bath-applied. Diethyl terephthalate (DTP), which is also known to have estrogenic actions, had little effect on both the responses and the decay of both receptors.

Animals↗
PubMed2001

Cigarette smoking, blood pressure and serum lipids and lipoproteins in middle-aged women.

The relationship of cigarette smoking with blood pressure and serum lipids and lipoproteins was studied in the 3934 middle-aged women aged 40 to 59 years. After adjusting age, body mass index (BMI), alcohol intake and physical activity scores, the mean systolic and diastolic blood pressures (SBP and DEP, respectively) did not indicate dose-dependent relationships. The largest significant mean differences in SBP (4.6 mmHg), DBP (3.9 mmHg), high density lipoprotein cholesterol (HDL-C) (9.6 mg/dL), ratio of total cholesterol to HDL-C (TC/HDL-C) (0.8), triglycerides (TG) (22.9 mg/dL) and the logarithmic transformation of TG (Log TG) (0.26) were found between the non-smokers and smokers. When age, BMI, alcohol intake and physical activity scores were included in the forward stepwise multiple regression analyses, there were negative relationships found for cigarette smoking and SBP, DBP and HDL-C and positive relationships for cigarette smoking and TC/HDL-C, TG, Log TG and low density lipoprotein cholesterol. Although the results are somewhat variable, the present study shows cigarette smoking is negatively associated with SBP and DBP and unfavorably associated with serum lipids and lipoproteins in middle-aged women.

Adult↗
PubMed2001

[Indication and outcome of extended right hemihepatectomy combined with pancreatoduodenectomy for bile duct carcinoma].

During the past 10 years, we have performed extended right hemihepatectomy combined with pancreatoduodenectomy (rtHPD) in eight patients with bile duct carcinoma. We compared the results in these patients with those in 43 bile duct carcinoma patients who underwent extrahepatic bile duct resection with more extensive hepatectomy than hemihepatectomy. Our indication for rtHPD is bile duct carcinoma of the diffuse type involving the intrapancreatic bile duct. For patients with obstructive jaundice, biliary drainage was performed preferentially in the part of the liver to be preserved. Portal vein embolization was performed before extended right hemihepatectomy or left trisectorectomy. Complete external drainage of pancreatic juice followed by second-stage pancreatojejunostomy was performed in five rtHPD patients. There were no hospital deaths or hepatic failures. There were four 5-year survivors after rtHPD. There was no significant difference between the cumulative 5-year survival rates after rtHPD (71%) and non-HPD (42%). Patients with bile duct carcinoma whose prognosis can be improved only by rtHPD exist and should be treated by rtHPD. However, considering the reported high mortality rate after this procedure, rtHPD should not be performed in an institution where its safety cannot be guaranteed.

Aged↗
PubMed2001

Patch repair of postinfarction pseudo- and subepicardial aneurysm of the left ventricle.

Left ventricular pseudo-aneurysm and subepicardial aneurysm are rare complications of myocardial infarction. However, the prognosis of medical treatment is extremely poor and the operative procedure is controversial. We experienced 3 consecutive patients with this unusual left ventricular aneurysm, and described the clinical presentation, operative procedure and its result in these patients. The interval from myocardial infarction to discovering aneurysmal formation is short. The term was within a month. In all patients, the papillary muscle was in the proximity of the orifice of the aneurysm. Patch repair of these unusual left ventricular aneurysms may be effective for improvement of left ventricular function without mitral regurgitation.

Aged↗
PubMed2001

Cerebral protection during surgery for aortic arch aneurysms.

Surgical repair of aneurysms or dissections involving the transverse aortic arch and the distal aortic arch carries a considerable risk of cerebral complications. Currently, deep hypothermic circulatory arrest (DHCA), moderate hypothermic circulatory arrest or DHCA with selective cerebral perfusion (SCP) and DHCA with retrograde cerebral perfusion (RCP) are used as means to protect the central nervous system. DHCA alone is simple, but the safe time of DHCA is limited. RCP is an alternative technique for cerebral protection that can prolong the safe time of DHCA. SCP offers virtually unlimited time in isolating cerebral circulation. With the improvement of cardiopulmonary bypass (CPB) materials and myocardial preservation, DHCA with SCP is our current preference of an adjunct for cerebral protection, although possible increment of mortality and morbidity associated with a prolonged DHCA and CPB remains to be overcome.

Aged↗
PubMed2001

[A case of cervical subpial lipoma].

The authors report the rare case of a 48-year-old woman with a cervical subpial lipoma unassociated with spinal dysraphism. Her symptoms were progressive weakness and numbness in the four extremities and the neurological symptom of mild cervical myelopathy. Plain radiographs of the cervical spine showed diffuse widening of the spinal canal, which was occupied by a large low-density mass revealed by axial CT scan. MR imaging identified the mass as being dorsolateral to the cord in the intradural region. It was hyperintense on both T1- and T2-weighted images. Axial images with fat suppression sequence clearly showed dorsal nerve roots traveling through the lesions, but the interface between the spinal cord and lesion was not well demarcated. A cervical laminectomy between C3-6 revealed a yellowish subpial mass after the dura was opened. The mass was only partially resected and intraoperative SEP monitoring data remained normal including N20 latency. Histological examination found mature adipose tissue covered by thickened pia mater, which was compatible with a diagnosis of lipoma. After surgery, no complications occurred and the patient's myelopathy subsequently improved. Subpial spinal lipomas unassociated with dysraphism are uncommon and they are reported in only 1% of all spinal cord tumors. They are thought to arise from premature dysjunction of the cutaneous ectoderm during neural tube formation. Without any invasive procedure, MR imaging is indispensable to show their longitudinal dimension as well as their infiltrative extension into the spinal cord. The main purpose of surgery is to decompress the lipoma from the adjacent neural structures, because it is benign in nature and there is no cleavage plane identifiable between the lipoma and the spinal cord.

Female↗
PubMed2001

[Effect of G-CSF (nartograstim) on neutropenia (leukopenia) induced by taxane in metastatic breast cancer--time-course changes in neutrophil and leukocyte counts].

Since 1997, we have used docetaxel and paclitaxel as the second-line and third-line chemotherapies against anthracycline-resistant metastatic breast cancer. However, these taxane compounds induced neutropenia and leukopenia, which may be reversed by G-CSF (Nartograstim). We thus examined the therapeutic efficacy of nartograstim for time-course changes in neutrophil and leukocyte counts in these patients. No difference was observed in neutrophil or leukocyte count whether the patient was treated with docetaxel or paclitaxel. Neutrophil and leukocyte counts reached a nadir on days 7 to 8 after administration. With a 5-6 day administration of nartograstim, neutrophil or leukocyte counts recovered by the second or third day after the nadir, indicating that the chemotherapy was given safely with nartograstim. In these same patients receiving a given treatment cycle, the number of days until reaching the nadir were almost identical for neutrophils and leukocytes; however, the duration of the nadir and the time to count recovery was significantly longer for neutrophils than for leukocytes. In the clinical setting, the parameter "leukocyte count" has been occasionally used for evaluation of the severity of myelosuppression, because the data is more readily available. However, at least during the nadir, the "neutrophil count" should be used as the parameter of choice.

Antineoplastic Agents↗
PubMed2001

[A case of intrasellar meningioma mimicking pituitary adenoma].

The authors report a patient with a rare intrasellar meningioma mimicking pituitary adenoma. A 60-year-old man was admitted to our hospital for evaluation of general fatigue. He had no neurological deficit including visual function. Endocrinological tests revealed panhypopituitarism. The craniogram showed slight enlargement of the sella turcica with thinning of the dorsum sellae. CT scan and MR imaging demonstrated a homogeneously enhanced intrasellar mass with slight suprasellar extension. Partial removal of the mass was performed via the transsphenoidal approach because it was extremely firm and hemorrhagic. Histological diagnosis was transitional meningioma. The patient has been well for two years after surgery without tumor progression on MR imaging. It is mandatory to distinguish intrasellar meningioma from pituitary adenoma preoperatively because of marked difference in their treatment strategies. Despite recent advances in neurodiagnostic imaging, it may still be difficult to differentiate pituitary adenoma from intrasellar meningioma. When we re-evaluated the MR imaging, we recognized that the tumor had demonstrated specific findings, ruling out pituitary adenoma, namely bright and homogeneous enhancement, dense enhancement in the early phase on the dynamic MR study, and flow void signal within the mass. The authors emphasize that careful evaluations of MR imaging will allow the correct preoperative diagnosis in patients with intrasellar meningioma mimicking pituitary macroadenoma.

Adenoma↗
PubMed2001

[The significance of neoadjuvant intra-arterial chemotherapy for locally advanced breast cancer by different methods].

For neoadjuvant intra-arterial (IA) chemotherapy in locally advanced breast cancer patients, Seldinger's methods were found to be convenient and had the same effect and outcome as conventional methods. The prognosis of the patients in whom IA chemotherapy was locally effective and had fewer than n 1 lymph node metastases was comparatively favorable. However, several patients who underwent IA chemotherapy later experienced local recurrence, and the cause of these patient's death was distant metastases in almost all cases. We recommend neoadjuvant IA and systemic chemotherapy, and systemic adjuvant chemotherapy.

Adult↗
PubMed2001

[A case of locally advanced breast cancer successfully treated with wide resection and reconstruction of chest wall with A-O metallic plates].

A 63-year-old female with locally advanced breast cancer was treated with preoperative chemotherapy using docetaxel. The therapeutic regimen was comprised of four cycles at 3-week intervals. One cycle consisted of 80 mg of docetaxel which was administered on day 1. A remarkable response was confirmed. The side effects such as leukopenia, general fatigue and alopecia were moderate and had no influence on the patient's QOL. After preoperative chemotherapy, a full thickness chest wall resection was performed. Chest wall defect was reconstructed with orthopedic A-O metallic plates, Marlex mesh and rectus abdominis myocutaneous flap. These metal plates were very useful because it was easy to bend and twist them manually to fit the defect at the time of operation. Moreover, the curved metal plates preserved the cone form of the chest cage. The postoperative course was favourable without frail chest or wound infection.

Antineoplastic Agents, Phytogenic↗
PubMed2001

[Thrombosis of the abdominal aorta in a patient with nephrotic syndrome].

Nephrotic syndrome frequently causes thromboembolic complications in veins. Arterial thrombosis, however, is relatively rare. We report the case of a 47-year-old male with nephrotic syndrome complicated with abdominal aortic thrombosis. The patient complained of pain in the bilateral lower extremities 2 weeks after the development of nephrotic syndrome. The aortogram revealed complete occlusion of the abdominal aorta just below the origin of the inferior mesenteric artery. Necrosis of the legs extended rapidly, and he eventually lost his legs. Among various predisposing factors, hypercoagulability associated with nephrotic syndrome seemed to be responsible for the development of thrombosis. Thrombotic complications are sometimes serious in the nephrotic patient. Assessment for the risk factors is required to warrant prophylactic anticoagulation.

Amputation, Surgical↗
PubMed2001

[A case of Hirayama's disease successfully treated by anterior cervical decompression and fusion].

The authors report the case of a 16-year-old boy with Hirayama's disease(juvenile muscular atrophy of unilateral upper extremity). The present history began about 6 months previously, when he noticed slowly progressive weakness with atrophy of the left hand and forearm. Neurological examination on admission revealed diffuse distribution of muscular atrophy including the left hypothenar, thenar, forearm, and triceps muscles. However, EMG studies identified neurogenic changes in both upper extremities. There was no long tract sign of objective sensory impairment. Plain spinal radiograms showed abnormal kyphosis of the cervical vertebrae. Cervical MR images in the neutral position demonstrated focal atrophy of the cervical cord at the C 5-6 vertebral levels. When the neck was flexed, the cervical cord was displaced anteriorly and was compressed over the posterior surface of the C 5-6 vertebral bodies. He was diagnosed to have Hirayama's disease(cervical flexion myelopathy). Via an anterior approach, he underwent a C 5 vertebrectomy followed by fixation of C 4-6 vertebral bodies using iliac bone and plate system. He recovered from surgery without any complications and has been well for the past 6 months with remarkable improvement of muscle strength. Application of cervical collar for 3 to 4 years has been generally advocated for the treatment of Hirayama's disease because progression of signs and symptoms is usually expected to cease within several years. However, some patients were reported not to response to conservative treatment for more than 5 years after their onsets. To these patients surgery seems to be beneficial, because it can give rise to permanent stable fixation with much shorter period of external cervical immobilization compared with cervical collar therapy, in which long-term application is frequently unbearable in many patients. In conclusion, the present case emphasizes the importance of surgical treatment in Hirayama's disease not only to improve neurological deficits but regain better quality of life.

Adolescent↗