Double ophthalmic artery visualized with new technology.

The anatomy of the double ophthalmic artery was visualized using fused imaging. The images demonstrate the first angiographic visualization of the course of the vessel.

Swine hybrid aneurysm model for endovascular surgery training.

The aim of this study was to develop a technically simple swine aneurysm-training model by inserting a silicone aneurysm circuit in the cervical vessels. A silicone aneurysm circuit was created by designing multiple aneurysms in size and configuration on a silicone vessel. Five swine underwent surgical implantation of this circuit in the cervical vessels: one end in the common carotid artery and the other in the external jugular vein. Using this model, an aneurysm coiling procedure was simulated under fluoroscopic guidance, roadmapping and digital subtraction angiography. Creating an aneurysm model for training purposes by this method was technically simple and enabled the formation of a wide variety of aneurysms in a single procedure. The quality of the model was uniform and the model was reproducible. Coiling training using this model resembled a realistic clinical situation. The swine hybrid aneurysm-training model was advantageous from the standpoint of technical simplicity in the creation and variety of aneurysms it provided. The swine hybrid aneurysm model may be an additional option for aneurysm coiling training.

Wire-probing technique to revascularize subacute or chronic internal carotid artery occlusion.

During endovascular revascularization of subacute and chronic occlusion of the cervical internal carotid artery (ICA) it may be difficult to penetrate the lesion. Selecting the appropriate "true lumen", a remnant of what had been the arterial lumen, at the initial step may facilitate the procedure. Because plaque at the carotid bifurcation is known to propagate from the posterior wall, a gateway to this "true lumen" should exist in the anterior side of the occluded stump. This hypothesis was studied retrospectively in our series of revascularizing ICA subacute and chronic occlusion. Eleven patients underwent endovascular revascularization for symptomatic cervical ICA occlusion. Procedures were performed by initially penetrating the occluded stump with a guidewire, followed by supporting catheter advancement through the occluded segment to secure the distal normal arterial lumen. Cases were analyzed with regard to the location of initial guidewire penetration. Eight patients underwent successful revascularization. In five cases, the entry point to the occluded stump was located at the anterior side, and in three, at the posterior side. Two posterior stump penetration cases were met with resistance in guidewire advancement, whereas penetration was smooth in the anterior cases. In addition, two posterior stump penetration cases resulted in contrast stasis in the posterior ICA wall. In our series of revascularizing cervical ICA subacute and chronic occlusion, initially targeting the anterior side of the occluded stump resulted in favorable results. This may be the result of selecting the "true lumen" at the beginning of the procedure.

A statistical model of signal-noise in scanning electron microscopy.

A statistical model describing signal-noise generation and development along the signal formation process in a standard scanning electron microscope (SEM) using an Everhart-Thornley secondary electron detector is derived. Noise in the detector signal is modeled to originate from a cascade of five signal conversion stages. Based on the derived model, general conclusions are drawn concerning the total signal-to-noise ratio (SNR) at each stage, and the influence of each stage on the total SNR of the detector signal. The model is furthermore applied to a real-world SEM, and verified by experimental data.

Protected endovascular revascularization of subacute and chronic total occlusion of the internal carotid artery.

BACKGROUND AND PURPOSE: The natural course of symptomatic carotid artery occlusion with hemodynamic impairment is poor. Surgical revascularization may improve the outcome; however, its efficacy has not been established yet. The goal of this study was to characterize the technical and clinical outcomes following endovascular recanalization of the ICA under cerebral circulatory protection. MATERIALS AND METHODS: Endovascular recanalization was attempted in 8 patients with symptomatic ICA occlusions. The duration of the occlusion ranged from 7 days to 7 months (mean, 2.5 months), and the mean length of the occlusion was 95 mm. Cerebral hemodynamics ipsilateral to the side of the occlusion were severely impaired in all patients. The endovascular procedure was performed under total cerebral circulatory protection, beginning with proximal protection with a subsequent switch to distal protection after successful guidewire passage. RESULTS: The occlusion was recanalized successfully in 7 of 8 patients (88%), resulting in improvement of ipsilateral cerebral hemodynamics without symptomatic stroke. Small asymptomatic ischemic lesions were detected in 6 of 8 patients (75%) on DWI, and 1 patient developed a mild groin hematoma. Ischemic episodes did not recur during the mean follow-up period of 19 months. However, 1 patient experienced asymptomatic reocclusion, which was re-treated successfully without complications, while another patient developed mild retinal hemorrhage at 3 months after the procedure due to the combination of antiplatelet and anticoagulant therapy. CONCLUSIONS: Endovascular revascularization of an ICA occlusion is feasible and well-tolerated in patients with subacute or chronic total occlusion of the ICA.

[Planned sedation with dexmedetomidine hydrochloride after pediatric cardiac surgery; an institutional experience].

Dexmedetomidine hydrochloride (DEX) is a newly developed alpha-2 adrenergic agonist sedative and has been shown to be effective in post-surgical patients, providing not only unique sedation but also stabilization of hemodynamic and respiratory function. We investigated the hemodynamic and respiratory effects and efficacy of DEX in 84 consecutive patients (age <6 months: 18, 6-12 months: 13, 1-3 years: 29, 4-9 years: 18, >10 years: 5, male:female = 44:40) who were sedated by DEX in combination with a small dose of midazolam and morphine. DEX was commenced at an initial dose of 0.7 microg/kg/hr during surgery, approximately 1 hour prior to transfer to the intensive care unit (ICU). DEX infusion was maintained at a rate of 0.2-0.7 microg/kg/hr after ICU admission throughout weaning from mechanical ventilation and extubation. The dose of the sedatives was optimized by scoring on Ramsay's sedative scale. There were no undesirable hemodynamic changes throughout the DEX infusion. Respiration was maintained and all patients were extubated uneventfully. Optimal level of sedation was achieved in all patients. There were no adverse events related to DEX administration. Moreover, junctional ectopic tachycardia (JET) and severe pulmonary hypertension (PH) leading to clinical deterioration, which are the major causes of postoperative morbidity in pediatric cardiac surgery, occurred at a low incidence in this series. Our DEX protocol provided 1) satisfactory postoperative sedation without compromising hemodynamics and respiration, and 2) prevention and amelioration of postoperative morbidity caused by sympathomimetic stimulation, in pediatric cardiac surgery.

Implications of sphingosine kinase 1 expression level for the cellular sphingolipid rheostat: relevance as a marker for daunorubicin sensitivity of leukemia cells.

We recently reported increased sphingosine kinase 1 (SPHK1) and decreased neutral sphingomyelinase 2 (NSMase2) gene expression in myelodysplastic syndromes and acute leukemia. This alteration is supposed to change the cellular sphingolipid metabolites; however, positive correlations were observed between daunorubicin (DA)-IC50 and the SPHK1 message but not between DA-IC50 and NSMase2 messages, when 16 different leukemia cell lines were used to analyze the relationship between gene expressions and chemosensitivity against DA. Using two cell lines with either the highest or lowest SPHK1 expression, cellular ceramides and sphingosine 1-phosphate (S1P) were quantified by liquid chromatography/mass spectrometry. Increased ceramide was observed in DA-sensitive, but not in DA-resistant cell lines treated with low doses of DA. Upon DA treatment, S1P decreased more in the sensitive cell lines than in resistant cell lines. A SPHK inhibitor recovered the DA sensitivity of DA-resistant cells. The modulation of SPHK1 gene expression by either overexpression or using siRNA affected the DA sensitivity of representative cell lines. Results clearly show that SPHK1 is both a good marker to predict the DA sensitivity of leukemia cells and a potential therapeutic target for leukemia with high SPHK1 expression, and suggest that the sphingolipid rheostat plays a significant role in DA-induced cytotoxicity.

[Successful administration of nifekalant hydrochloride for postoperative junctional ectopic tachycardia in congenital cardiac surgery].

Two episode of junctional ectopic tachycardia (JET) caused hemodynamic deterioration early after tetralogy of Fallot repair in an 8-month-old infant. Sinus rhythm resumed in each of the episodes immediately after intravenous administration of nifekalant hydrochloride (NIF), a newly developed Vaughan-Williams class III antiarrhythmic drug in Japan. Although QT interval was modestly prolonged with NIF, no life-threatening ventricular arrhythmia (i.e., torsades de pointes) occurred. NIF might be an effective alternative in the treatment of postoperative JET in congenital cardiac surgery.

[Bidirectional Glenn shunt without cardiopulmonary bypass].

From April 2002 to March 2005, 18 patients having undergone bidirectional Glenn shunt (BDG) without cardiopulmonary bypass (CPB) [off-pump BDG] were retrospectively reviewed. During BDG anastomosis, a temporary bypass was established between superior vena cava (15) or innominate vein (3) and main pulmonary artery (16) or right atrium (2). Hemodynamics and oxygenation were maintained well throughout the temporary bypass time. There was no emergent use of CPB. Mean transpulmonary pressure gradient immediately after and 24 hours after the BDG were 6.7 and 5.6 mmHg, respectively. Echocardiography showed mild flow turbulence at the anastomosis in 1 case. This simple and inexpensive technique provided good surgical view with stable hemodynamics enabling satisfactory BDG in selected cases. Furthermore, it could avoid adverse effects of CPB such as lung injury and possible blood transfusion. This experience would encourage off-pump BDG combined with more challenging procedures.

[Prophylactic treatment of oral sildenafil citrate for pulmonary hypertension in an infant treated with inhaled nitric oxide after open-heart surgery].

A 3-month-old boy with coarctation of the aorta (CoA), ventricular septal defect (VSD), atrial septal defect, and severe pulmonary hypertension (PH) underwent one-stage repair consisting of patch closure of VSD and coarctation repair. Inhalation of nitric oxide (iNO) was commenced to treat residual severe PH on the day of the operation. Oral sildenafil citrate was commenced on the day 1 and iNO was gradually weaned off on the day 3. There was no "rebound", severe increase in pulmonary artery pressure, which commonly occurs after discontinuation of iNO. Then the patient was extubated without any difficulties or recurrent PH. The oral sildenafil citrate therapy was ceased on the day 8. Prophylactic use of oral sildenafil citrate for PH might be an useful alternative to shorten the duration of iNO therapy and intensive care unit (ICU) stay in the selected patients after congenital open heart surgery.

[Successful implantation of a metal coronary angioplasty stent for bronchomalacia of the right tracheal bronchus associated with right isomerism complex in an early infant].

One-month-old boy had severe emphysema of the right upper lobe due to the stenotic tracheal bronchus compressed between the distorted right patent ductus arteriosus (PDA) and the right aortic arch associated with right isomerism complex. He underwent a left modified Blalock-Taussig shunt and a division of the PDA on cardiopulmonary bypass. Extracorporeal lung support (ECLS) was introduced because of severe hypoxemia caused by remaining bronchomalacia of the tracheal bronchus. On postoperative day 3, a metal coronary angioplasty stent was implanted at the stenotic lesion under fluoroscopic and bronchoscopic guidance. He was successfully weaned from ECLS and then respirator after the implantation. This simple stenting procedure might be an effective alternate in the treatment of bronchomalacia or bronchial stenosis in early infancy.

[Successful resection of left ventricular myxoma in a toddler; report of a case].

A 4-year-old girl was found to have large left ventricular myxoma without any tumor-related symptoms. She underwent an urgent surgery and the myxoma was successfully removed through a left ventriculectomy. Great care was taken to prevent tumor-embolization during surgery, and to resect the endocardium attaching directly to the tumor. Future surveillance of this case warrants our operative technique described in this report.

Usefulness of switching to cabergoline from other dopamine agonists in patients with advanced Parkinson's disease.

Problems associated with long-term treatment of advanced Parkinson's disease (PD) include motor complications and psychotic and autonomic symptoms. We switched patients from bromocriptine (BR) or pergolide (PER) to cabergoline (CB) therapy and investigated CB's usefulness in alleviating such problems. Subjects were 30 patients (mean age 68.2 years; 13 receiving BR, 17 PER) with PD complicated by effects of long-term treatment but in whom their dose of dopamine (DA) agonist was contraindicated due to adverse reactions. Patients were switched to CB over a 2-4-week period. Hoehn-Yahr and Unified Parkinson Disease Rating Scale (UPDRS) I-IV "on" and "off" scores improved in both the BR and PER groups. CB was not discontinued due to adverse reactions in any patient. In conclusion, switching to CB is useful in patients in whom it is problematic to increase their dose of DA agonist due to motor complications or psychotic symptoms of advanced PD.

Periodic structures and diurnal variation in blood pressure and heart rate in relation to microgravity on space station MIR.

Four Russian crew members were studied on space station MIR, and blood pressure (BP) and heart rate (HR) data were continuously collected. BP and HR data were collected on earth 1 day before orbital flight to the space station, then at weeks 8, 16 and 24 during space flight, and again 1 or 2 days after returning to earth. Time serial data for BP and HR were analyzed by spectral analysis with the MemCalc system (Suwa Trust, Sapporo, Japan). Periodic structures of diurnal variation in systolic blood pressure (SBP), diastolic blood pressure (DBP) and HR were compared at 24-hour, 12-hour and 8-hour intervals, these being determined as the main periodic components for the assessment of BP and HR variability. The 24-h mean levels of SBP and HR during space flight were unchanged. Waking SBP was not different from pre-flight values. During sleep, in-flight changes in HR did not differ from pre-flight values. SBP during sleep in orbit increased to over pre-flight values. Waking DBP was reduced during flight. The SBP and HR phases over a 24-hour cycle were shortened with a more pronounced shortening in weeks 8 and 16 compared with pre-flight values, and at week 24 recovered to preflight values. The 12, 8-hour-cycle remained unchanged, and were similar to pre-flight values. At the space station, the astronauts' mission was carried out under strict control of sleeping and waking hours; therefore, their 24-hour schedule is an artificially constructed situation. Main periodicity structures were maintained by strict control of lifestyle during long-term space flight. The conclusions reached were as follows: 1) SBP levels during sleep in a space environment increased compared with those on earth; 2) the periodicity phase of BP and HR shifted toward to 24-hour cycle as a result of long-term space flight, even though these periods shortened after a few months compared with pre-space flight values.

Treatment for intracranial cerebral artery stenosis.

SUMMARY: Symptomatic intracranial cerebral artery stenosis is largely resistant to drug treatment. Regardless of their locations, lesions may cause cerebral infarction with a frequency of 7-10% in a year, but the natural history of asymptomatic intracranial cerebral artery stenosis remains unclear. Revascularization is indicated for symptomatic lesions which show resistance to drug treatment, while bypass surgery is the accepted therapeutic indication for haemodynamic ischemia. Endovascular treatment is effective in haemodynamic ischemia, and is also expected to be effective against embolic symptoms. Bypass surgery for anterior circulation cases is safe because of its low incidence of complications, whereas bypass surgery for posterior circulation cases is technically difficult and has a high associated complication rate. Hence, endovascular treatment is currently favored for posterior circulation cases, and has also been introduced for anterior circulation cases. Endovascular treatment has become a widespread modality for intracranial cerebral artery stenosis, but there are many unsolved problems associated with complications, technology and devices. Therefore, in practice, endovascular treatment should be used only with a strict indication, and should be performed only after considerable thought and with appropriate informed consent.

Blood pressure variability during 120-day head-down bed rest in humans.

Influence of physical inactivity and microgravity to periodic structure of blood pressure was studied. Six healthy males were kept under head-down bed rest (HDBR) for 120 days. Blood pressure and heart rate (HR) were recorded by a portable sphygmomanometer and a Holter electrocardiogram, respectively. The results were analyzed by spectrum analysis. Phase, amplitude and acrophase of systolic blood pressure (SBP) by approximately 24, 12 and 8 h were measured before, 60, 120 day and after HDBR. The phase at 24, 12 and 8 h did not show significant changes during HDBR, and acrophase showed a tendency to shift to 14:00 after HDBR. Amplitude for 24 h tended to attenuate during bed rest (BR), and significantly increased after BR. The results of this study suggest that the circadian rhythm of SBP and HR were maintained by strict control of sleep, awakening and food intake in microgravity model of a long-term BR state. However, the tendency to decrease 24-h cyclic amplitude of SBP appeared to be the rhythmic modulation related to cardiovascular deconditioning.

Cytomegalovirus DNA among children attending two day-care centers in Tokyo.

BACKGROUND: In the USA, a high prevalence rate of cytomegalovirus (CMV) excretion among children in day-care centres was reported. However, there is no research about the prevalence rate of CMV among children in day-care centres in Japan. METHODS: The CMV excretion was studied in 54 children's saliva samples, collected from two different day-care centres in Tokyo. As a control, the prevalence of CMV was studied among 61 healthy children who did not attend any day-care centers. The CMV DNA in saliva were examined by polymerase chain reaction (PCR) analysis with one pair of primers for the immediate early region. The sequence of CMV genomes were examined in CMV PCR positive samples. RESULTS: Of the 54 saliva samples, 20.6% (6/29) and 24% (6/25) were CMV PCR positive in children at A and B day-care centres, respectively. The overall positivity of CMV PCR in saliva was 22.2% (12/54). Of the 61 saliva samples as the control study, 6.5% (4/61) were CMV PCR positive. There was a difference in the positivity in each age group of day-care centres and normal control. Each sample of the same day-care center gave conclusive and identical sequence results. CONCLUSION: We suspected that in each day-care center that there was one prevailing viral strain. We suppose that CMV infections were acquired inside the day-care centres. This is a first report which described viral transmission in day-care centres in Japan.