Internal circular suture annuloplasty for aortic valve repair

Stabilizing the aorto-ventricular junction is integral in aortic valve repair. We report our technique of internal circular suture annuloplasty. We used a continuous horizontal mattress suture of a single thick expanded polytetrafluoroethylene suture (CV-3). We put 4 stitches per sinus, so the suture was below the cusp attachment line at the nadirs and passed through the interleaflet triangle at the upper aorto-ventricular junction level. The suture was reinforced with pericardial pledgets on both sides of each commissure. We used this technique in 12 patients. The diameter of aorto-ventricular junction was reduced from 25 ± 2 mm to 22 ± 1 mm (n = 11) and was 22 ± 1 mm at the latest follow-up (4-74 months, median 41, n = 10). In 2 patients with large aorto-ventricular junction (27 mm or more), expected annular reduction was not achieved. Our modified technique is simple and seems durable. It may be useful for mild annular dilatation.

[Long-term Outcomes of the Maze Procedure Omitting the Ablation Line to The Superior Vena Cava]

OBJECTIVE

In an effort to avoid postoperative sick sinus syndrome( SSS), we omit the ablation line to the superior vena cava( SVC) in the Cox-mazeⅢ lesion set. We report the long-term outcomes, including the freedom from SSS.

METHODS

We studied 102 patients who underwent bi-atrial maze procedure for persistent atrial fibrillation (Af) from 2009 through 2023. Bipolar radio frequency ablation or cryoablation was used except for right-side atriotomy and right atriotomy. Cryoablation was used for atrioventricular annulus. The patient age was 68±9.4. Duration of Af was 3.4±6.5 years (unknown 9 cases). The amplitude of f-wave in V1 was 0.182±0.095 mV and it was<0.1 mV in 19 (18.6%). Diameter of the left atrium was 50±8.9 mm, and left atrial volume index was 89±37 ml/m2. Ninety-one (89.2%) patients underwent concomitant mitral valve surgery.

RESULTS

Survival rate was 99% at 1 year and 96% at 5 years. Freedom from Af was 92% at 1 year and 88% at 5 years. Freedom from permanent pacemaker implantation (PPI) was 87% at 1 year and 83% at 5 years.

CONCLUSIONS

Defibrillation rate and the incidence of PPI was comparable to those in previous reports after standard Cox-mazeⅢ. SSS after maze for persistent Af seem due to patient.

Patency of separate tube grafts for intercostal artery reconstruction: Size and length matter

OBJECTIVES

Low patency is a major concern when using separate tube grafts for intercostal artery reconstruction. We aimed to elucidate the optimal size and length of grafts from the patency and computational fluid dynamics.

METHODS

The patency, size, and length of separate tube grafts were evaluated in 41 patients. Computational fluid dynamics simulation was performed in a model derived from a patient with a patent 12-mm graft of 15 mm in length, with 2 simulation models with a smaller (8-mm) or longer (30-mm) graft.

RESULTS

A total of 49 grafts were used for intercostal artery reconstruction. There was 1 in-hospital death and 2 spinal cord injuries. The patency rate, which could be evaluated in 46 grafts, was 63% (29/46). It was 71% (24/34) in thoraco-abdominal aortic replacement and 42% (5/12) in descending aortic replacement. Among 14 patients in whom all grafts were occluded, no patients developed spinal cord injury. All grafts longer than 25 mm were occluded (n = 5). Eight- and 10-mm grafts showed better patency than 12-mm grafts in thoraco-abdominal aortic replacement (p = 0.008), when grafts were shorter than 25 mm. Computational fluid dynamics simulation revealed vortical flow within the 12-mm graft, which did not reach the intercostal orifice, while helical flow was maintained throughout the cardiac cycle within the 8-mm graft.

CONCLUSIONS

Eight- and 10-mm grafts seemed better than 12-mm grafts, and grafts should be kept shorter than 25 mm. Computational fluid dynamics simulation may shed light on the issue of optimal intercostal artery reconstruction technique.

Surgical Approaches to Single-Stage Extended Aortic Repair from the Ascending to the Distal Descending Aorta

Single-stage extended replacement from the ascending to the distal descending aorta or beyond is a formidable operation that should be preserved for those who have no other option or those who are physically fit, and should be performed in the experienced centers. Hybrid operations combining open surgical repair with thoracic endovascular aortic repair through a median sternotomy incision are preferable because these operations are less invasive than the extended open aortic repair and the risk of spinal cord ischemia is lower compared with the frozen elephant trunk operation. However, these operations are associated with the inherent demerits of endovascular aneurysm exclusion. When the underlying aortic pathology necessitates extended open aortic repair in a single stage, approaches such as the anterolateral partial sternotomy, straight incision with rib cross, and extended thoracotomy with sternal transection may be useful to provide sufficient exposure for both aortic reconstruction and organ protection, with less surgical stress to the patients.

18-Fluorodeoxyglucose positron emission tomography in the diagnosis of prosthetic aortic graft infection: the difference between open and endovascular repair

OBJECTIVES

18-Fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) has been reported as useful for diagnosing aortic graft infection. However, 18F-FDG uptake may depend upon various factors including open versus endovascular repair and time from surgery. We aimed to elucidate the factors influencing its uptake and the diagnostic value of 18F-FDG PET/CT after open and endovascular repair.

METHODS

Hospital database of PET/CT (N = 14 490) and our departmental database were cross-checked to identify those who underwent 18F-FDG PET/CT after aortic repair. Patient's data were retrieved from the chart. Images were reviewed by 2 nuclear medicine specialists in consensus, and the presence of increased 18F-FDG uptake was recorded. The maximum standardized uptake value (SUV max) was measured.

RESULTS

Among the 1112 patients who underwent aortic repair between 2011 and 2022, 71 patients were identified. Eighteen patients underwent 18F-FDG PET/CT for suspected graft infection and the remaining 53 patients for other purposes (malignancy, etc.). Fourteen patients were treated as aortic graft infection. They had significantly higher SUV max than those without graft infection [mean 8.64 (standard deviation 2.78) vs 3.40 (standard deviation 0.84); P < 0.01]. In the non-infected grafts, SUV max was higher early after open surgical repair, while it remained low after endovascular repair.

CONCLUSIONS

After endovascular aortic repair, a constant cut-off value of 'SUV max = 4.5' seems appropriate for diagnosing graft infection, since it remains low and stable from the early postoperative period. After open surgical repair, it seems acceptable to have 'stepwise cut-off value' depending on the time from surgery.

Efficacy of Early Closed Toe Amputation for Toe Ulcers with Suspected Osteomyelitis after Revascularization for Chronic Limb-Threatening Ischemia

Objective: In this study, we aim to evaluate the efficacy of early closed toe amputation on the wound management of toe ulcers with suspected osteomyelitis after revascularization for chronic limb-threatening ischemia (CLTI).

Methods: This retrospective study included patients who have underwent revascularization for toe ulcers associated with CLTI at Shizuoka Red Cross Hospital from 2015 to 2021. Wound management comprised early closed toe amputation for toe ulcers with suspected osteomyelitis (19 toes in 17 patients) or conservative treatment (35 toes in 26 patients). The primary endpoint was wound healing after revascularization. We compared the wound healing rate at 90 days and median healing time of early closed toe amputation versus conservative treatment.

Results: Compared with the conservative treatment, early closed toe amputation was able to achieve a better wound healing rate at 90 days (89.5% vs. 68.6%; P<0.01) and a shorter median healing time (19 days vs. 62 days; P=0.01).

Conclusion: There remains no established wound management for toe lesions associated with CLTI. Despite its several disadvantages including wound infection and possible foot deformity, early closed toe amputation for toe ulcers with suspected osteomyelitis can be considered a safe approach in terms of wound management.

Type B Acute Aortic Dissection as a Perioperative Complication after an Endovascular Abdominal Aortic Repair

Type B aortic dissection (TBAD) is a rare but catastrophic complication of endovascular aneurysm repair (EVAR). We report two cases of TBAD occurring in the perioperative period of EVAR. The intraoperative and postoperative courses were unremarkable. Routine postoperative computed tomography angiography (CTA) revealed TBAD. Conservative treatment was successful, and no adverse aortic events occurred. TBAD that occurs in the perioperative period is likely to be iatrogenic in origin, uncomplicated, and managed with medical therapy: its prognosis is better than when the condition develops in the midterm postoperative period.

Loss of Ftsj1 perturbs codon-specific translation efficiency in the brain and is associated with X-linked intellectual disability

FtsJ RNA 2'-O-methyltransferase 1 (FTSJ1) gene has been implicated in X-linked intellectual disability (XLID), but the molecular pathogenesis is unknown. We show that Ftsj1 is responsible for 2'-O-methylation of 11 species of cytosolic transfer RNAs (tRNAs) at the anticodon region, and these modifications are abolished in Ftsj1 knockout (KO) mice and XLID patient-derived cells. Loss of 2'-O-methylation in Ftsj1 KO mouse selectively reduced the steady-state level of tRNA^Phe in the brain, resulting in a slow decoding at Phe codons. Ribosome profiling showed that translation efficiency is significantly reduced in a subset of genes that need to be efficiently translated to support synaptic organization and functions. Ftsj1 KO mice display immature synaptic morphology and aberrant synaptic plasticity, which are associated with anxiety-like and memory deficits. The data illuminate a fundamental role of tRNA modification in the brain through regulation of translation efficiency and provide mechanistic insights into FTSJ1-related XLID.

Effect of Atheromatous Aorta on Thromboembolic Complications after Endovascular Aortic Aneurysm

Objective: The purpose of this study was to evaluate the effect of atheromatous aorta on thromboembolic complications after endovascular aortic aneurysm repair (EVAR) and to assess the risk factors for these complications. Materials and Methods: This retrospective study included patients who underwent EVAR for an abdominal aortic aneurysm at the Shizuoka Red Cross Hospital from 2007 to 2018. We defined atheromatous aorta as a thoracic shaggy aorta or abdominal aorta with neck thrombus. The main outcome was renal dysfunction and peripheral embolization (thromboembolic complications). We compared the incidence of thromboembolic complications between patients with normal aorta and atheromatous aorta. Moreover, we assessed the risk factors associated with thromboembolic complications in patients with atheromatous aorta. Results: Patients with atheromatous aorta had significantly more thromboembolic complications, such as renal dysfunction (24.5% vs. 3.9%; P<0.001) and peripheral embolization (12.3% vs. 0.0%; P<0.001) than those with normal aorta, respectively. We identified no risk factors associated with thromboembolic complications in patients with atheromatous aorta. Conclusion: Atheromatous aorta increases the risk of thromboembolic complications after EVAR. However, there is no established therapy for these thromboembolic complications. Further studies are necessary to determine the appropriate therapy, including appropriate preoperative medication, to prevent these complications.

Intimal sarcoma in an ascending aortic Dacron graft mimicking a thrombus

Although aortic sarcomas are extremely rare, they may arise in association with a Dacron graft. Here, we report a case of an intimal sarcoma in an ascending aortic Dacron graft implanted 17 years earlier. The patient presented with multiple cerebral infarctions; clinically, a thrombus was found to cause the embolic stroke. He successfully underwent re-replacement of the ascending aorta. Although the initial postoperative histopathological diagnosis was a thrombus, he died of multiple metastases of the malignant tumour after 5 months of the surgery. A histopathological re-evaluation of the explant using immunohistochemistry revealed that the mass was an intimal sarcoma.

Importance of Distal Sealing during Endovascular Aneurysm Repair Using Aneurysmal Common Iliac Artery as Landing Zone

BACKGROUND

Although the use of aneurysmal common iliac artery (CIA) as the landing zone during endovascular aortic aneurysm repair EVAR remains an essential procedure, this procedure may increase the risk of late complications such as ongoing CIA dilatation and type Ib endoleak (CIA-related complications). We hypothesized that incomplete sealing of the aneurysmal CIA segment during EVAR could increase the incidence of CIA-related complications. In this study, we evaluated the midterm results of EVAR with aneurysmal CIA used as the landing zone and assessed the importance of distal sealing in this procedure.

METHODS

We retrospectively reviewed all cases of endovascular aneurysm repair using CIA as landing zone between 2007 and 2015 that had at least 3 years' follow-up. We defined aneurysmal CIA as maximum diameter ≥18 mm. The main outcome was the incidence of CIA-related complications. We compared midterm results between normal CIA and aneurysmal CIA. Next, we analyzed risk factors for CIA-related complications in aneurysmal CIA.

RESULTS

Four complications occurred in normal CIA (mean follow-up, 66.5 ± 22.1 months); 21 occurred in aneurysmal CIA (mean follow-up, 62.2 ± 20.5 months). The 5-year portion of freedom from CIA-related complications was 97.3% in normal CIA and 69.4% in aneurysmal CIA (P < 0.001). Multivariable analysis in aneurysmal CIA showed that unsealed CIA segment length was only risk factor for CIA-related complications. Given the receiver operating characteristic curve results, we defined the unsealed CIA segment ≥10 mm as incomplete sealing. The hazard ratio for incomplete sealing associated with CIA-related complications was 3.92 (95% confidence interval 1.62-9.46, P = 0.02).

CONCLUSIONS

Use of aneurysmal CIA as landing zone increases the risk of CIA-related complications. However, maximum sealing of the aneurysmal CIA segment could prevent these complications.

Carotid stenosis with impaired brain flow reserve is associated with an increased risk of stroke in on-pump cardiovascular surgery

OBJECTIVES

To prevent haemodynamic stroke during cardiovascular surgery in patients with carotid stenosis, we routinely evaluated magnetic resonance angiography and selectively evaluated brain perfusion single-photon emission computed tomography with acetazolamide challenge. Off-pump surgery was preferred when cerebral blood flow reserve was impaired. This strategy's usefulness was investigated.

METHODS

Among the 1059 consecutive patients who underwent preoperative carotid screening by magnetic resonance angiography, 84 (7.9%) patients had >50% stenosis; 45 of them underwent brain single-photon emission computed tomography. The severity of cerebral blood flow compromise was estimated by the proportion of Stage 2 area in the affected territory, in which both resting blood flow (<32 ml/min) and flow reserve (<10%) were reduced.

RESULTS

Perioperative stroke occurred in 1.7% overall (18/1059), in 6% (5/84) of those with carotid stenosis and in 1.3% (13/975) of those without stenosis (P = 0.010). On subgroup analysis, carotid stenosis was associated with an increased risk of stroke in the on-pump surgery group [n = 949, 5/59 (9%) with stenosis vs 11/890 (1.1%) without stenosis, P = 0.002], while it was not in the off-pump group [n = 110, 0/25 (0%) with stenosis vs 2/85 (2%) without stenosis, P = 0.59]. With respect to the role of acetazolamide single-photon emission computed tomography, 2 of the 4 patients with Stage 2 area >10% undergoing on-pump surgery without preceding carotid revascularization developed stroke, while none of the 21 patients with Stage 2 area <10% undergoing on-pump surgery developed stroke (P = 0.020).

CONCLUSIONS

Carotid stenosis is a risk factor for perioperative stroke in on-pump surgery. Patients with large Stage 2 area (>10%) are at increased risk of perioperative stroke when on-pump surgery is performed.

Spinal cord ischaemia after endovascular aneurysm repair

We report the case of a patient who developed paraparesis 2 days after endovascular aneurysm repair for a right common iliac aneurysm. The patient had undergone thoracic endovascular aortic repair. The left subclavian artery was occluded, but the left internal iliac artery was preserved. The patient fully recovered from the paralysis within 3 months. This case illustrates the importance of collateral blood supply to the spinal cord from the lumbosacral region, especially when other sources are occluded.

Characterizing saccular aortic arch aneurysms from the geometry-flow dynamics relationship

OBJECTIVE

Low wall shear stress (WSS) has been reported to be associated with accelerated atherosclerosis, aneurysm growth, or rupture. We evaluated the geometry of aortic arch aneurysms and their relationship with WSS by using the 4-dimensional flow magnetic resonance imaging to better characterize the saccular aneurysms.

METHODS

We analyzed the geometry in 100 patients using multiplanar reconstruction of computed tomography. We evaluated WSS and vortex flow using 4-dimensional flow magnetic resonance imaging in 16 of them, which were compared with 8 age-matched control subjects and eight healthy young volunteers.

RESULTS

Eighty-two patients had a saccular aneurysm, and 18 had a fusiform aneurysm. External diameter/aneurysm length ratio and sac depth/neck width ratio of the fusiform aneurysms were constant at 0.76 ± 0.18 and 0.23 ± 0.09, whereas those of saccular aneurysms, especially those involving the outer curvature, were higher and more variable. Vortex flow was always present in the aneurysms, resulting in low WSS. When the sac depth/neck width ratio was less than 0.8, peak WSS correlated inversely with luminal diameter even in the saccular aneurysms. When this ratio exceeded 0.8, which was the case only with the saccular aneurysms, such correlation no longer existed and WSS was invariably low.

CONCLUSIONS

Fusiform aneurysms elongate as they dilate, and WSS is lower as the diameter is larger. Saccular aneurysms dilate without proportionate elongation, and they, especially those occupying the inner curvature, have higher and variable sac depth/neck width ratio. When this ratio exceeds 0.8, WSS is low regardless of diameter, which may explain their malignant clinical behavior.

A Case of External Compression of Femoral Vein by the Enlarged Iliopsoas Bursa with Long Term Edema

The iliopsoas bursa is the largest bursa in the region of hip joint. It is unusual that these bursa become symptomatic. However the bursa can compress femoral vein, leading to lower extremity edema. A 58-year-old man was referred to our department for his unilateral leg edema which had been treated as deep vein thrombosis without any favorable response. Magnetic resonance angiography was performed, which demonstrated enlarged iliopsoas bursa compressing his femoral vein. Surgical removal of the bursa was performed. The postoperative course was uneventful, and the patient is free from symptoms with no evidence of recurrence.

Successful surgical exclusion of rapidly expanding kommerell diverticulum following a total arch replacement for an acute type a aortic dissection

A 50-year-old man presented with an acute type A aortic dissection with an aberrant right subclavian artery. Emergent total arch replacement with an elephant trunk was performed. Intraoperatively, the origin of the aberrant right subclavian artery could not be resected because it was located too far from the distal arch. After two weeks, the patient became aware of dysphagia. Postoperative computed tomography showed the esophagus was compressed anteriorly by the aneurismal origin of this aberrant vessel (Kommerell diverticulum) with a patent false lumen. Additional replacement of the descending aorta via left thoracotomy was performed immediately to exclude a Kommerell diverticulum.

Vertical-cavity organic lasers with distributed-feedback structures based on active Bragg reflectors

Optically pumped organic thin-film lasers were fabricated by stacking top and bottom Bragg reflectors with an inner-cavity active layer between the reflectors. We observed single-longitudinal-mode laser operation at 555 nm by doping pyrromethene-567 dye into all the stacked layers. The threshold of the laser was 30% less than that of a laser operated with nondoped Bragg reflectors, which was in good agreement with calculations.

Hippocampal theta-related cellular activity in the superior colliculus of the urethane-anesthetized rat

In the present study, 93 cells in the superior colliculus (SC) were recorded extracellularly during the simultaneous occurrence of spontaneous theta field activity, sensory-induced (tail pinch) theta field activity, and large amplitude irregular (LIA) field activity, recorded from an electrode located in the stratum moleculare of the hippocampal formation (HPC). The effect of the intravenous administration of atropine sulfate (ATSO4) was also tested on SC cellular activity. The field activities of theta and LIA were recorded from all layers of the SC and were found to be temporally coherent with the same activities recorded simultaneously from the HPC, during all conditions tested. By using the criteria of Colom and Bland (1987) for the classification of theta-related cells, 75 of 93 cells (81%) were found to be related to the generation of theta field activity in the HPC and 18 of 93 (19%) were nonrelated. All cells recorded discharged in a tonic, nonrhythmic pattern during the theta HPC field states. Of the 75 theta-related cells, 61 (81%) were classified as tonic theta-ON cells and 14 (19%) as tonic theta-OFF cells. Although these cell types were found in all three layers of the SC, the majority of tonic theta-ON cells were recorded in the intermediate layer, and the tonic theta-OFF cells were dispersed evenly between the intermediate layer and the deep layer of the SC. The intravenous administration of ATSO4 abolished theta field activity in the HPC and SC, and the theta-related increase in the discharge rate of all tonic theta-ON cells tested. However, the same treatment did not have any effect on the discharge properties of tonic theta-OFF cells. The same stimuli that resulted in the inhibition of the discharge rates of these cells (tail pinch and electrical stimulation of the PH) in the predrug condition did so after the administration of ATSO4.

Desynchronization of carbachol-induced theta-like activities by alpha-adrenergic agents in guinea pig hippocampal slices

The effect of alpha-adrenergic agents on theta-like activity (TLA) in guinea-pig hippocampal slices was studied. TLA was induced by a cholinergic agent, carbachol. TLA had a frequency of 4.66+/-0.08 Hz (mean+/-S.E.M.) and an amplitude of 96.3+/-8.3 microV in the dentate gyrus (DG). The alpha-adrenergic agents epinephrine and clonidine increased the frequency and decreased the amplitude of TLA in a concentration-dependent manner. The agents also increased antidromic and orthodromic population spike (PS) amplitudes of the granule cells, but did not have any effect on population EPSP. Another alpha-adrenergic agent, guanabentz, had the same effect as clonidine. The adenylate cyclase inhibitor SQ22536 suppressed the increase in PS amplitude by clonidine. The results suggest that these alpha2-adrenergic agents facilitate the activity of granule cells through the activation of the alpha2-adrenoreceptor and cAMP pathway, and the facilitation causes the desynchronization of TLA.

Suppression of pair-pulse depression of the population spike in the dentate gyrus during carbachol-induced theta-like activity in guinea pig hippocampal slices

In pair-pulse stimulation experiments, pair-pulse depression (PPD) of the population spike (PS) occurred at intervals shorter than 20 ms in the dentate gyrus in guinea pig hippocampal slices. Application of 50 microM carbachol resulted in an increase in the test PS amplitude and caused suppression of PPD. This suppression was antagonized by atropine sulfate, a muscarinic receptor antagonist. Carbachol at 50 microM induced intermittent bursts of theta-like activity (TLA). We compared the pair-pulse index (PPI) during TLA with that in a rest period between bursts of TLA. The PPI was defined as the ratio of the amplitude of the test PS to that of the conditioning PS. The PPI during TLA were significantly larger than that during the rest period, although there were no significant differences in the conditioning PS amplitude and the test pEPSP slope. When TLA was induced, the PPI during the rest period was increased by bicuculline. The PPI during TLA did not change significantly with the drug. The increase by bicuculline in the PPI during the rest period was caused by increase in the test PS amplitude. PPD can occur due to inhibition of granule cell activity by inhibitory neurons. Our findings suggest that the action of inhibitory neurons on granule cell activity is suppressed by activation of muscarinic receptors, with stronger suppression during TLA than during the rest period between bursts of TLA.

Theta-activity-dependent and -independent muscarinic facilitation of long-term potentiation in guinea pig hippocampal slices

Cholinergic input to the hippocampus originates in the septum and diagonal band. Guinea pig hippocampal slices in a bath of carbachol, a cholinergic agonist, displayed different patterns of rhythmical activities depending on the carbachol concentration. Exposure to 50 or 100 microM led to intermittent induction of theta-like activities (TLAs). Long-term potentiation (LTP), induced by tetanus. was facilitated at concentrations within the optimum range for generating TLAs. This facilitation was blocked by the muscarinic receptor antagonist atropine. Augmentation of LTP during TLAs was greater than that during the rest period of TLAs which, in turn, was greater than that induced without activation of the muscarinic receptors. These results suggest that there are two muscarinic facilitation processes of LTP, one dependent on and the other independent of TLAs, with the former being more easily facilitated than the latter.

Synthesis of novel poly(ethylene glycol) derivatives having pendant amino groups and aggregating behavior of its mixture with fatty acid in water

Novel poly(ethylene glycol) (PEG) derivatives having pendant amino groups were prepared by copolymerization of allyl glycidyl ether with ethylene oxide followed by chemical modification of the double bond side chains. Dropwise addition of the mixture of monomers to the anionic initiator gave an almost monodisperse (Mw/Mn = 1.05) random copolymer. 1H NMR spectra showed that addition of 2-aminoethanethiol to the pendant allyl groups of the copolymer was completely carried out in methanol without catalyst, and an aminated PEG derivative with a definite structure was obtained. Acetylation of the pendant amino groups was readily performed by acetic anhydride with triethylamine. A gel permeation chromatogram of the acetylated polymer showed a very narrow molecular weight distribution (Mw/Mn = 1.06) of the polyamine. These cationic PEG derivatives make amphiphilic polyion complexes with fatty acids, and then aggregate in water. A fluorescence study using pyrene as a microenvironment probe revealed that the aminated PEG-lauric acid ion complex could take up the hydrophobic fluorescence probe into the lipophilic field inside, and they also had a critical aggregation concentration at [lauric acid] = 0.7 mM. It is much lower than the critical micelle concentration of the corresponding fatty acid sodium salts, indicating high stability of the polymer-fatty acid aggregate.

[Extraction and purification of the three major vitamin D metabolites using C18 and NH2 cartridges and measurement of 25-hydroxyvitamin D]

In this study, the three major vitamin D metabolites: 25-hydroxyvitamin D [25(OH)D], 24,25-dihydroxy-vitamin D [24,25(OH)2D], 1,25-dihydroxyvitamin D [1,25(OH)2D] were clearly separated using a NH2 cartridge after acetonitrile and C18 cartridge extraction. In the NH2 cartridge purification procedure, 25(OH)D was eluted with hexane/dichloromethane (50:50), 24,25(OH)2D was eluted with hexane/dichloromethane (20:80) and 1,25(OH)2D was eluted with hexane/isopropanol (75:25). Contamination of each fraction with two other metabolites were less than 1.4%. Recoveries of added 3H-25(OH)D, 3H-24,25-(OH)2D and 3H-1,25(OH)2D were 73.2 +/- 2.45%, 60.0 +/- 2.98% and 63.5 +/- 3.37%, respectively. Using the 25(OH)D fraction after the NH2 cartridge procedure, we measured 25(OH)D using a competitive protein binding assay. The intra- (n = 10) and interassay (n = 8) coefficients of variation were 4.60-8.41% and 6.62-16.4%, respectively. Analytical recovery of added 25(OH)D was in the range of 81.2-130%. The 25(OH)D values were 17.4 +/- 6.02 ng/ml (mean +/- SD) in serum from 110 healthy volunteer collected in May. The correlation of 25(OH)D values was good between cartridge purification and high performance liquid chromatography (HPLC) purification. (gamma = -0.38 + 1.03x, r = 0.953, n = 36). This purification using a simple cartridge procedure was suitable for the measurement of 25(OH)D, and preferable to the time-consuming HPLC purification.

Cutaneous vasodilatation responses synchronize with sweat expulsions

To examine whether cutaneous active vasodilatation is mediated by sudomotor nerve fibres we recorded cutaneous blood flow and sweat rates continuously with laser-Doppler flowmetry and capacitance hygrometry, respectively, from the dorsal and plantar aspects of the foot in 11 male subjects at varying ambient temperatures (Ta) between 22 and 40 degrees C (relative humidity 40%). In a warmer environment (Ta 29-40 degrees C), predominant responses of the blood flow curve from the sole of the foot were transient depressions (negative blood flow responses, NBR), whereas those from the dorsal foot were transient increases (positive blood flow responses, PBR). The PBR on the dorsal foot occurred spontaneously or in response to mental or sensory stimuli, and when PBR did not fuse with each other the rate of PBR was linearly related to tympanic temperature. When dorsal foot sweating was continuous, PBR on the dorsal foot almost entirely synchronized with sweat expulsion. When dorsal foot sweating was intermittent PBR sometimes occurred on the dorsal foot without corresponding sweat expulsions, but these PBR showed a complete correspondence with subthreshold sweat expulsion seen on a methacholine-treated area. The amplitude and the duration of PBR showed a significant linear relationship with the amplitude and the duration of the corresponding sweat expulsion. In a thermoneutral or cooler environment (Ta 22-29 degrees C), PBR occurred on the sole of the foot when mental or sensory stimuli elicited sweating in that area. Thus, PBR occurred when and where sweating appeared. Atropine failed to abolish PBR on the dorsal foot. Blockade of the peroneal nerve eliminated both PBR and NBR on the dorsal foot.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of body and head positions on bilateral difference in tympanic temperatures

We have examined the nonparallel changes in tympanic membrane temperatures (Tty) from the two ears in response to various changes in body and head positions. Upon assuming a lateral recumbent position, the Tty on the lower side increased while that on the upper side decreased. Pressure application over a wide area of the lateral chest only caused inconsistent and obscure asymmetric changes in Tty. A lateral flexion of the head with the subject sitting upright and a rotation of the head to the side in a supine position induced an increase in the Tty on the lower side compared to that on the upper side. The temperature and blood flow of the forehead often decreased on the lower side and increased on the upper side, although such responses were not always concomitant with the asymmetric changes in Tty. A dorsal flexion of the head with the subject in a reclining position caused a slight increase in the Tty, whereas raising the head upright induced a slight decrease in them. Two additional experiments were carried out with single photon emission computed tomography using 99mTc-hexamethylpropyleneamine oxime as tracer, and a slight, relative decrease in counts was noted in the right hemisphere during rotation of the head to the right. These results would strongly suggest that unilateral increases and decreases in Tty could have been caused by one-sided decreases and increases, respectively, in blood flow to the brain and/or the tympanic membrane, induced by a vasomotor reflex involving vestibular stimulation.

Information propagation by spatio-temporal pattern change of Ca2+ concentration throughout Physarum polycephalum with repulsive stimulation

The development of a spatio-temporal pattern of Ca2+ concentration (Ca2+ pattern) in the plasmodium of Physarum polycephalum during repulsive response was studied using fura-2. In the migrating cell, the gradient of the Ca2+ concentration (Ca2+ gradient) immediately showed a decrease in local concentration in the area (S-site) stimulated by 50 mM KCl. The concentration rose and then decreased in a site neighboring the S-site. This transient increase of Ca2+ concentration, the duration of which was approx. 10 minutes, was propagated to the site most distant from the S-site. There, the Ca2+ concentration gradually rose and remained at a high level. Twenty-five minutes after stimulation, a new Ca2+ gradient was established throughout the plasmodium. The migratory direction of the cell as a whole then changed. In this process, although the period of Ca2+ oscillation changed at the S-site, this change was only local to the site. During the information processing of the local repulsive stimulus, the transient Ca2+ increase propagated the local information about the stimulus to the non-stimulation sites (NS-sites), leading to the generation of a new pattern and the start of coordinated migration of the plasmodium.

Seasonal changes of circadian pattern in human rectal temperature rhythm under semi-natural conditions

A phase delay of the circadian rectal temperature rhythm existed in three human subjects leading normal lives under semi-natural conditions: the rectal temperature began to increase later in summer than in the other three seasons.

[Atrophic macular degeneration in a patient with olivopontocerebellar atrophy]

Description of a man with heredoataxia, presenting with an isolated primary atrophic maculopathy in which the participation of the posterior pole was disclosed by photopic and scotopic ERG irrespective of the localized appearance of this condition. Ophthalmoscopically, the patient's sister showed only fine pigment migrations at the macula, whereas local ERG revealed a macular lesion.