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Biomedical subjects

S Shirai

Publications and source records attributed to S Shirai.

At least 19 recordsLinked to original sources
PubMed2006

Brachytherapy technique for abdominal wall metastases of colorectal cancer: ultrasound-guided insertion of applicator needle and a skin preservation method.

PURPOSE: To report a technique of interstitial brachytherapy for the treatment of subcutaneous metastatic abdominal wall tumors. MATERIAL AND METHODS: We developed a brachytherapy technique consisting of ultrasound-guided insertion of applicator needles to avoid the organs at risk, such as intestines, and saline injection into the subcutaneous tissue between the tumor and the skin to decrease the skin dose. We encountered three patients with painful metastases from rectal carcinoma in the abdominal wall refractory to external radiotherapy. They were subjected to this brachytherapy with a single dose of 20 Gy. RESULTS: The procedure was safely achieved in all three patients. Long-lasting pain reduction and tumor shrinkage was obtained without early or late complications. CONCLUSION: This interstitial brachytherapy technique seems to be feasible in the treatment of metastatic abdominal wall tumors.

Abdominal Neoplasms↗
PubMed2006

Usefulness of mini-tracheostomy and torque controlled insertion of applicator in fractionated endobronchial brachytherapy.

Endobronchial brachytherapy was developed as effective treatment of endobronchial cancer and fractionated schedule is applied to decrease late toxicity. However, repeated bronchofiberscopy is onerous to the patient and restricts the treatment schedule itself. We applied mini-tracheostomy for a ready access route, and a torque controlled technique for easy insertion of the endobronchial applicator. Eight patients with tracheobronchial cancer invasion were treated with endobronchial brachytherapy of 18-30 Gy/3-5 fractions/1.5-2.5 weeks (median 24 Gy/4 fractions/2 weeks) at reference points of 5 mm from the bronchial surface. The averaged individual irradiation and single session times were 4 min and 24 min, respectively. There were no procedure-related complications. These technical improvements may facilitate flexible fractionated dose prescriptions.

Aged↗
PubMed2005

Selective conformal radiotherapy for arteriovenous malformation involving the spinal cord.

Radiotherapy has seldom been used in the treatment of arteriovenous malformations (AVM) involving the spinal cord because of the cord's limited radiation tolerance. A 57-year-old woman with progressive myelopathy due to AVM was treated with a selective conformal radiation therapy (55.6 Gy/20 days) on the nidus region preserving the spinal cord, drainer veins and involved bones. The drainers and symptoms were minimized at the end of treatment and disappeared over 2 years. This case illustrates the usefulness of selective conformal radiation therapy.

Arteriovenous Malformations↗
PubMed2001

Histopathological examination of two cases of anterior staphyloma associated with Peters' anomaly and persistent hyperplastic primary vitreous.

AIMS: To clarify the developmental mechanism and critical period for the uncommon complex of Peters' anomaly and persistent hyperplastic primary vitreous (PHPV). METHODS: Two eyes with Peters' anomaly and PHPV were histologically examined by serial section. One eye was enucleated at age 7 months (case 1) and the other at age 4 months (case 2) owing to severe anterior staphyloma. RESULTS: In both eyes, defects in the endothelium, Descemet's membrane, and posterior stroma were observed in the central cornea, and the degenerative lens adhered to the posterior surface of the defective corneal stroma. Also, in both eyes, the anterior chamber space was not formed and the undifferentiated iris stroma adhered to the posterior surface of the peripheral cornea. Mesenchymal tissue containing melanocytes was observed behind the degenerative lens, and the pigment epithelium was absent at the lower nasal side of the ciliary body in case 1. In case 2, mesenchymal tissue containing scattered melanocytes in the vitreous cavity was seen on the posterior retina. Based on the histological findings, both cases were diagnosed as Peters' anomaly caused by the faulty separation of the lens vesicle, PHPV, maldevelopment of the iris and ciliary body, and goniodysgenesis. CONCLUSION: Migratory disorders of neural crest cells from 4 to 7 weeks of gestation may be responsible for various ocular anomalies including Peters' anomaly and PHPV, as observed in these cases.

Abnormalities, Multiple↗
PubMed2001

[A case of small cell lung cancer with paraneoplastic cerebellar degeneration and anti-voltage-gated calcium channel antibody].

A 55-year-old man presenting with 4 weeks of progressive dysarthria, gait ataxia and vertigo was admitted to our hospital. Chest X-ray films revealed a mass shadow in the right upper lobe of the lung, and transbronchial brushing specimens showed small-cell carcinoma. Extensive examination revealed metastatic lesions in the mediastinal lymph nodes and liver, but brain MRI showed no findings suggestive of metastasis or atrophy. A diagnosis of PCD associated with SCLC was made, and the patient had a high titer of anti-P/Q-type VGCC antibody. He was treated by chemotherapy and radiation therapy, which resulted in a transient improvement in the PCD symptoms.

Autoantibodies↗
PubMed2000

Ocular and systemic features of Peters' anomaly.

BACKGROUND: To clarify the relationship between associated systemic anomalies and ocular manifestations in patients with Peters' anomaly, a retrospective study was conducted. METHODS: We classified 37 patients with Peters' anomaly into two groups, one with (+) and one without (-) systemic anomalies. RESULTS: The systemic anomaly (+) group consisted of 13 patients, eight males and five females, with mean age of 2.3 months. Peters' anomaly was bilateral in six cases and unilateral in seven. Corneolenticular adhesion was observed in 11 cases. Associated ocular anomalies were seen in 12 cases, and developmental glaucoma was present in eight cases. The systemic anomaly (-) group comprised 24 patients, 13 males and 11 females, with mean age of 28.3 months. Peters' anomaly was bilateral in 11 cases and unilateral in 13. Corneolenticular adhesion was observed in five cases. The associated ocular anomalies were observed in 10 cases, and developmental glaucoma was accompanied in six cases. The incidences of cases with corneolenticular adhesion, those with other ocular anomalies, and those with glaucoma were significantly higher in the systemic anomaly (+) group than in the systemic anomaly (-) group. CONCLUSIONS: Peters' anomaly accompanying corneolenticular adhesion and/or other ocular anomalies should be evaluated for the presence of systemic anomalies.

Corneal Opacity↗
PubMed2000

Ruptured aneurysm at the origin of the median artery of the corpus callosum associated with accessory middle cerebral artery--case report.

A 62-year-old male presented with ruptured anterior communicating artery (ACoA) aneurysm manifesting as severe headache associated with the rare combination of median artery of the corpus callosum (MACC) and accessory middle cerebral artery (MCA). Computed tomography demonstrated diffuse subarachnoid hemorrhage. Left carotid angiography demonstrated an anomalous vessel originating from the ACoA complex and passing forward in the interhemispheric fissure between the two companion A2 segments. This vessel was identified as the MACC. Another anomalous vessel originated from the left A1-A2 segment and passed into the sylvian fissure. This vessel was identified as the accessory MCA. Left frontotemporal craniotomy was performed to clip the neck of the aneurysm. After identifying both A1 and A2 segments, accessory MCA, and the MACC, the aneurysm neck was occluded successfully. The ACoA complex is one of the most frequent sites of vascular anomalies. Preoperative and intraoperative care is required to identify the presence of anomalies of the ACoA complex prior to clip placement, to avoid accidental damage or clipping, which may result in severe neurological deficits.

Anterior Cerebral Artery↗
PubMed1999

Critical period for retinoic acid-induced developmental abnormalities of the vitreous in mouse fetuses.

To elucidate the underlying developmental mechanisms of persistent hyperplastic primary vitreous (PHPV) in humans, we investigated a mouse model for PHPV induced by retinoic acid. We treated C57BL/6NJcl mice at various stages of pregnancy (gestation days 7, 8, 9, 10, 11, or 12) with the teratogen retinoic acid, which affects the migration of neural crest cells. Untreated pregnant mice served as a control group. The eyes of the fetuses were examined histologically on day 18 on gestation. Developmental abnormalities of the vitreous were defined as the presence of excessive mesenchymal tissue in the vitreous cavity. The incidence of developmental abnormalities of the vitreous in all groups, except for those treated on day 12 of pregnancy, significantly exceeded that in the control group (P<0.01). The histological characteristics of the observed vitreous abnormalities in mice resembled those found in PHPV clinically. Retinoic acid-induced abnormalities in mice can serve as an experimental model for PHPV by environmental factors. Results suggest that the critical period for these retinoic acid-induced abnormalities was during days 7 to 11 of gestation, which corresponds to a critical period of 2.5 to 7 weeks of gestation for PHPV in humans.

Abnormalities, Drug-Induced↗
PubMed1999

Effects of K+Channel blockers on acetylcholine-induced vasodilation in guinea-pig choroid.

The purpose of this study is to clarify which K+channels contribute to the acetylcholine (ACh)-induced vasodilation from the diameter changes in arterioles of the guinea-pig choroid. The choroid was isolated from the guinea-pig eyeball, pinned flat on a silicone rubber plate and superfused with warmed oxygenated (35 degrees C) Krebs solution. Diameters of choroidal arterioles were measured using video microscopy and a computer program for analysis. The effects of K+channel inhibitors (glibenclamide, tetraethylammonium [TEA], apamin and charybdotoxin [ChTX]) on the ACh-induced vasodilation were examined in arterioles which had been constricted by either norepinephrine (NE) or high K+solution. In NE (10(-5)m)-constricted arterioles, the combination of nitroarginine (10(-4)m) and indomethacin (10(-5)m) reduced ACh (10(-6)m)-induced vasodilatation by 24%. When high K+solution was used to constrict the arterioles, ACh-induced vasodilation was abolished by nitroarginine and indomethacin. In the presence of nitroarginine and indomethacin, the ACh-induced dilatation of NE-constricted arterioles was attenuated by TEA (10(-3)m), apamin (10(-7)m), and ChTX (10(-7)m) but not by glibenclamide (2x10(-5)m). Simultaneous application of apamin and ChTX inhibited the ACh (10(-6)m)-induced dilatation by 85%. In arterioles of guinea pig-choroid, nitric oxide and prostacyclin are not main mediators in ACh-induced vasodilation. Simultaneous activation of a set of Ca2+-sensitive K+channels may take most part of ACh-induced vasodilation.

Acetylcholine↗
PubMed1999

Anomalies associated with Axenfeld-Rieger syndrome.

BACKGROUND: To detect the associated anomalies in patients with Axenfeld-Rieger syndrome is clinically important, because early treatment for such anomalies is crucial to both visual and systemic development. This study was conducted to clarify the associated anomalies in the syndrome. METHODS: We evaluated 21 patients with Axenfeld-Rieger syndrome encountered at Nagoya City University Hospital over a 16-year period. Patients who presented with a prominent Schwalbe's line accompanying the iris strands were diagnosed as having Axenfeld-Rieger syndrome. RESULTS: The series consisted of 9 males and 12 females, ranging in age from 1 month to 41 years, mean 15.4+/-12.7 (SD) years. The syndrome was bilateral in 17 cases and unilateral in 4 cases. Hypoplasia of the iris was observed in 10 eyes of 6 patients. The associated ocular anomalies included sclerocornea in 6 eyes of 3 patients, developmental glaucoma in 5 eyes of 3 patients, persistent pupillary membrane in 4 eyes of 2 patients, microphthalmos in 3 eyes of 2 patients, and typical iris coloboma in 1 eye. Of 10 eyes with hypoplasia of the iris, 5 exhibited glaucoma. The accompanying systemic anomalies included 9 cases of dental anomalies, 5 of facial anomalies, and 3 of Alagille syndrome. CONCLUSIONS: All of the associated ocular and systemic anomalies appeared to arise from the maldevelopment of the neural crest cells. Patients with Axenfeld-Rieger syndrome should therefore be examined for the presence of anomalies in the tissues of neural crest origin. Patients with hypoplasia of the iris should be checked for glaucoma.

Abnormalities, Multiple↗
PubMed1999

Role of endothelium-derived vasodilators and K(+) channels in ischemic vasodilation of guinea-pig choroidal arterioles.

PURPOSE: To assess the roles of endothelium-derived vasodilators and K(+) channels on metabolic ischemia-induced vasodilation from diameter changes in choroidal arterioles of the guinea-pig. METHODS: The choroid was isolated from the guinea-pig eye-ball, pinned flat on a silicone rubber plate, and superfused with oxygenated warmed (35 degrees C) Krebs solution. Diameters of choroidal arterioles were measured using video microscopy and a computer program for analysis. Vasodilatory effects were examined after the choroid was exposed to glucose-free/NaCN solutions for 10 minutes. The effects of Nomega-nitro-L-arginine (nitroarginine), indomethacin, and K(+)<?Pub Caret> channel inhibitors (glibenclamide [Glib] and charybdotoxin [ChTX]) on ischemic vasodilation were assessed. RESULTS: Reversible vasodilation was observed when the choroid was exposed to glucose-free/NaCN (10(-3) M) solutions. Nitroarginine (10( -4) M), Glib (2x10(-5) M) and ChTX (10(-7) M) significantly inhibited glucose-free/NaCN (10(-3) M)-induced vasodilation by 47%, 62%, and 24%, respectively. No significant inhibitory effect was observed with indomethacin (10(-5) M). Simultaneous application of Glib and ChTX reduced vasodilation by 77%. When Glib and ChTX were added together to nitroarginine, dilation was reduced by 86%. With high K(+) ([K]o = 47.2 mM) Krebs solution, ischemia caused a slight vasodilation (11%), which was significantly inhibited by nitroarginine. CONCLUSIONS: In guinea-pig choroidal arterioles, glucose-free/ NaCN-induced ischemic vasodilation was mainly mediated by NO and K(ATP) channels. A part of NO-mediated vasodilation was induced independent of the opening of K(+) channels.

Animals↗
PubMed1999

[Sarcomatoid carcinoma of the urinary bladder in a hemodialysis patient: a case report].

The following is a case report bladder of sarcomatoid carcinoma in a Japanese 65-year old female patient treated with hemodialysis. She developed chronic renal failure due to chronic glomerulonephritis. Fifteen months after the beginning of the hemodialysis, continuous gross hematuria was noticed, and cystoscopy revealed a broad-based bladder tumor spreading from the right lateral wall to the posterior wall. The histopathologic diagnosis of the TUR-Bt specimens was sarcoma. Radical cystectomy was performed under the diagnosis clinical stage III, T3bN0M0. The post-operative histopathologic diagnosis of the tumor was sarcomatoid carcinoma, composed of nests of transitional cell carcinoma (G 3) and predominant areas of spindle cell sarcomatoid transformation. Sarcomatoid carcinoma of the bladder in a hemodialysis patient is extremely rare, and to date this may be only the second case in Japanese medical literature.

Aged↗
PubMed1999

Epidermal nuclear CIq deposits in a patient with amyopathic dermatomyositis.

We report a case of amyopathic dermatomyositis, in which C1q deposits on the epidermal nucleus were immunohistologically found as well as Ig deposits at the dermoepidermal junction (DEJ). Direct immunofluorescence (IF) examination of infiltrated erythematous lesions revealed C1q deposits on the epidermal nucleus and fibrinogen at the DEJ, and examination of hyperkeratotic erythematous lesions showed linear deposits of Ig G and Ig A at the DEJ but not in the nuclei of epidermal cells. The authors discuss the direct in vivo interaction between nucleus and immunoreactants in dermatomyositis.

Aged↗
PubMed1999

A case of an intraocular foreign body due to graphite pencil lead complicated by endophthalmitis.

We report a case of an 8-year-old boy who presented with an intraocular foreign body composed of graphite pencil lead. The patient had been accidentally poked in the right eye with a graphite pencil. Primary care consisted of corneal suturing and lens extraction. Two pieces of the pencil lead remained in the vitreous cavity following surgery, and 2 days later the patient developed endophthalmitis. Pars plana vitrectomy was performed immediately and the intraocular foreign bodies were removed through the scleral wound. Cultures of the vitreous fluid revealed no bacterial organisms. X-ray fluoroscopic analysis of the vitreous detected 1 ppm of aluminum (a constituent of the pencil lead). Although the clinical presentation indicated probable bacterial endophthalmitis, the detection of elemental aluminum within the vitreous cavity also suggested the possibility of further retinal toxicity due to some dissolving of the pencil lead.

Cataract↗
PubMed1998

Decreased hydration state of the stratum corneum and reduced amino acid content of the skin surface in patients with seasonal allergic rhinitis.

Recent studies of the stratum corneum (SC) in patients with atopic dermatitis (AD) have disclosed various functional impairments even in clinically unaffected skin. However, it has not been clear whether the presence of atopic background itself has any influence on the function of the SC. In this study, we conducted functional studies of the SC in the mid-portion of the flexor surface of the forearm of 49 skin lesion-free patients with allergic rhinitis to Japanese cedar pollen (atopic respiratory disease; ARD) in early spring, their disease-active season, by comparing the findings obtained with those in 28 patients with AD and 57 age-matched healthy control subjects. The results showed that the patients with ARD had significantly lower skin surface hydration levels assessed by high-frequency conductometry than those of the healthy control subjects. These levels were, however, not as low as those noted in moderately or severely affected patients with AD. Moreover, by measuring the amounts of water-soluble amino acids contained in the superficial portions of the SC, we found that these are also decreased at a marginal level (P = 0.051) in patients with ARD compared with levels in healthy control subjects. In contrast, the water barrier function of the SC evaluated by measurements of transepidermal water loss in patients with ARD was not different from that of the healthy control subjects. These results suggest that, although their skin appears normal clinically, the SC of the patients with ARD has functional deficiency in water-holding capacity.

Adult↗
PubMed1998

Facial spasm and paroxysmal tinnitus associated with an arachnoid cyst of the cerebellopontine angle--case report.

A 59-year-old female presented with a 3-year history of hemifacial spasm and paroxysmal tinnitus associated with an arachnoid cyst of the cerebellopontine angle, which was identified preoperatively by magnetic resonance imaging. Surgical decompression of the cyst and arterial decompression of the facial and acoustic nerves at their root exit zones resulted in complete resolution of the symptoms.

Arachnoid Cysts↗