The 2021 Magnonics Roadmap

Magnonics is a budding research field in nanomagnetism and nanoscience that addresses the use of spin waves (magnons) to transmit, store, and process information. The rapid advancements of this field during last one decade in terms of upsurge in research papers, review articles, citations, proposals of devices as well as introduction of new sub-topics prompted us to present the first roadmap on magnonics. This is a collection of 22 sections written by leading experts in this field who review and discuss the current status besides presenting their vision of future perspectives. Today, the principal challenges in applied magnonics are the excitation of sub-100 nm wavelength magnons, their manipulation on the nanoscale and the creation of sub-micrometre devices using low-Gilbert damping magnetic materials and its interconnections to standard electronics. To this end, magnonics offers lower energy consumption, easier integrability and compatibility with CMOS structure, reprogrammability, shorter wavelength, smaller device features, anisotropic properties, negative group velocity, non-reciprocity and efficient tunability by various external stimuli to name a few. Hence, despite being a young research field, magnonics has come a long way since its early inception. This roadmap asserts a milestone for future emerging research directions in magnonics, and hopefully, it will inspire a series of exciting new articles on the same topic in the coming years.

SAT0458 THE POLYMORPHISM ON FAT MASS AND OBESITY ASSOCIATED GENE (FTO) WAS ASSOCIATED WITH LOW BONE MASS IN JAPANESE COMMUNITY DWELLING POPULATION

Background:

A polymorphism onFTO(OMIM 610966) was reported as a causal variant for obesity, plays a critical rule not only in amount of adipose tissue but also in function of mitochondrial thermogenesis1.

Objectives:

To examine the association of the genotype on a single nucleotide polymorphism onFTOwith bone health.

Methods:

FTO rs1421085 polymorphism was genotyped in 1,601 community-dwelling Japanese participants. This cross-sectional study was nested in Nagasaki Islands Study, which is a prospective cohort in Goto City, in islands of Japan. Participants were recruited at medical check-ups for community dwelling population.

Bone mass of the calcaneus was evaluated with stiffness index calculated using a quantitative ultrasound measurement. Low bone mass was defined as a stiffness index less than 80 % of the young adult mean.

Sera and peripheral blood mononuclear cells were obtained. The SNP of rs1421085 was genotyped using hydrolysis probe. The chi-squared test was used to determine whether the variants were in equilibrium in that population. Trend for the median of BMI among genotypes was assessed using the Jonckheere-Terpstra test. Potential associations between FTO polymorphism and overweight and between the polymorphism and low bone mass were evaluated using logistic regression. All analyses were carried out using SPSS 23.

Results:

Genotype and allele frequencies for the polymorphism were in Hardy-Weinberg equilibrium (minor allele frequency 0.16, p = 0.40) in 1,601 community-dwelling persons (mean age was 68.5 years in men and 68.1 years in women).

There were significant associations between the minor allele and higher median of BMI on dose dependent manner in men (p = 0.04 for trend in men and p = 0.10 for trend in women, respectively), and between the minor allele and overweight (>25 in BMI, OR 1.52, 95%CI 1.07 2.14, p=0.02 in men, OR 1.48, 95%CI 1.16 1.95, p=0.01 in women).

Logistic regression analysis showed a significant protective association in men with carriers of minor allele against low bone mass after an adjustment for age and BMI (OR 0.63, 95%CI 0.44 0.90, p=0.01 in men, not significant in women).

Conclusion:

Our study indicated significant associations of the polymorphism onFTOwith BMI and bone mass among community dwelling men. The polymorphism may play a rule in a part of bone health with higher BMI and other beneficial functions.

References:

[1]N Engl J Med. 2015; 373: 895-907

Disclosure of Interests:

None declared

Perpendicular magnetic tunnel junction with a strained Mn-based nanolayer

A magnetic tunnel junction with a perpendicular magnetic easy-axis (p-MTJ) is a key device for spintronic non-volatile magnetoresistive random access memory (MRAM). Co-Fe-B alloy-based p-MTJs are being developed, although they have a large magnetisation and medium perpendicular magnetic anisotropy (PMA), which make it difficult to apply them to a future dense MRAM. Here, we demonstrate a p-MTJ with an epitaxially strained MnGa nanolayer grown on a unique CoGa buffer material, which exhibits a large PMA of more than 5 Merg/cm³ and magnetisation below 500 emu/cm³; these properties are sufficient for application to advanced MRAM. Although the experimental tunnel magnetoresistance (TMR) ratio is still low, first principles calculations confirm that the strain-induced crystal lattice distortion modifies the band dispersion along the tetragonal c-axis into the fully spin-polarised state; thus, a huge TMR effect can be generated in this p-MTJ.

Spermatogonial Nature of the Germ Cell Component of Canine Testicular Mixed Germ Cell-Sex Cord Stromal Tumours

The present study has characterized the germ cell component of canine testicular mixed germ cell-sex cord stromal tumours (MGSCTs) by examining the histological nature and histochemical and immunohistochemical features using gonocytic and spermatogonial cellular markers, c-Kit, placental alkaline phosphatase (PLAP), protein gene product 9.5 (PGP9.5), Sal-like protein 4 (SALL4), and the periodic acid-Schiff (PAS) reaction. Histologically, all 45 examples of MGSCTs were classified as spermatocytic seminomas (SSs) and Sertoli cell tumours in combination. The germ cell component of all MGSCTs was negative by PAS staining. Immunohistochemically, PLAP immunoreactivity was lacking in the germ cell component of all MGSCTs, which is not consistent with a gonocytic origin. The germ cell component was positive for PGP9.5 and SALL4 in all MGSCTs and positive for c-Kit in 53% of MGSCTs, which is consistent with the phenotype of spermatogonia. Furthermore, the germ cell component in 71% of MGSCTs had moderate immunoreactivity for SALL4, which is suggestive of a spermatogonial phenotype. Conversely, 29% of cases had a minor population of germ cells showing strong SALL4 immunoreactivity, suggesting a phenotype similar to prespermatogonia. The results suggest that the germ cell component of canine MGSCTs is morphologically classified as SS, with the majority of cases showing the spermatogonial phenotype and some cases containing a small population of prespermatogonia.

Accuracy of spinal curvature assessed by a computer-assisted device and anthropometric indicators in discriminating vertebral fractures among individuals with back pain

This study examined the accuracy of thoracic and lumbar kyphotic angles as well as anthropometric indicators for discriminating patients with vertebral fracture among Japanese women >50 years old with back pain. Along with region-specific kyphotic angles and anthropometric indicators, the combination of thoracic and lumbar kyphotic angles offered the highest accuracy.

INTRODUCTION

Vertebral fractures have been associated with thoracic kyphosis. However, reports on lumbar kyphotic changes in association with vertebral fracture are scarce. This study investigated the accuracy of thoracic kyphotic angle (TKA) and lumbar kyphotic angle (LKA) measurements as well as anthropometric indicators (wall-occiput distance (WOD) and rib-pelvis distance (RPD)) in discriminating patients with vertebral fracture.

METHODS

Lateral radiographs of the spine were obtained in 70 postmenopausal Japanese women who visited an orthopedic clinic with low back pain (mean age, 76.2 ± 9.0 years). Radiographic vertebral fracture was diagnosed using quantitative measurement according to Japanese criteria. Osteoarthritis (OA) was defined as Kellgren-Lawrence (KL) grade 3 or higher. TKA and LKA were measured using SpinalMouse®. WOD and RPD were also measured.

RESULTS

At least one vertebral fracture was present in 49 subjects (70 %). Women with vertebral fractures showed significant increases in LKA, TKA + LKA, and WOD and decreases in RPD. Logistic regression analysis showed significant association between TKA + LKA and vertebral fracture independent of the presence of OA. Receiver operating characteristic analysis revealed that TKA was useful for discriminating thoracic fractures (area under the curve (AUC), 0.730) and LKA was useful for lumbar fractures (AUC, 0.691). The combination of TKA + LKA offered the highest accuracy for detecting thoracic, lumbar, and any vertebral fractures, with AUCs of 0.779, 0.728, and 0.783, respectively. WOD and RPD showed low-to-moderate accuracies for thoracic, lumbar, and any vertebral fractures.

CONCLUSIONS

Assessment of spinal kyphosis by SpinalMouse® as well as anthropometric indicators proved useful in discriminating subjects with vertebral fractures. These convenient and radiation-free methods could contribute to early diagnosis of vertebral fractures and subsequent appropriate treatment, thus preventing additional osteoporotic fractures.

Abrupt transition from ferromagnetic to antiferromagnetic of interfacial exchange in perpendicularly magnetized L1(0)-MnGa/FeCo tuned by Fermi level position

An abrupt transition of the interfacial exchange coupling from ferromagnetic to antiferromagnetic was observed in the interface of perpendicularly magnetized L10-MnGa/Fe1-xCox epitaxial bilayers when x was around 25%. By considering the special band structure of the MnGa alloy, we present a model explaining this transition by the spin-polarization reversal of Fe1-xCox alloys due to the rise of the Fermi level as the Co content increases. The effect of interfacial exchange coupling on the coercive force (Hc) and the spin-dependent tunneling effect in perpendicular magnetic tunnel junctions (pMTJs) based on the coupled composite were also studied. Changes from the normal spin valve to inverted magnetoresistance loops corresponding to the coupling transition were observed in pMTJs with MnGa/Fe1-xCox as an electrode.

Associations of vertebral deformities and osteoarthritis with back pain among Japanese women: the Hizen-Oshima study

We examined the spinal distribution of the types of vertebral deformities and the associations of vertebral deformities and osteoarthritis with back pain in Japanese women. Midthoracic and upper lumbar vertebrae were more susceptible to deformity. Vertebral deformity and osteoarthritis were frequent and were associated with back pain.

INTRODUCTION

Vertebral fractures due to osteoporosis and osteoarthritis are both common and significant health problems in aged people. However, little is known about the descriptive epidemiology of the individual deformity types and the relative clinical impact in women in Japan.

METHODS

Lateral radiographs were obtained from 584 Japanese women ages 40 to 89 years old. Deformities were defined as vertebral heights of more than 3 standard deviations (SDs) below the normal mean. Osteoarthritis was defined as Kellgren-Lawrence (KL) grade 2 or higher. Information on upper or low back pain during the previous month was collected by questionnaire. We compared the spinal distribution of the three types of vertebral deformities (wedge, endplate, and crush) typical of fractures and examined the associations of number and type of vertebral deformities and osteoarthritis with back pain.

RESULTS

Fifteen percent of women had at least one vertebral deformity and 74% had vertebral osteoarthritis. The prevalence of upper or low back pain was 30.1%. Deformities were most common in the midthoracic and upper lumbar regions and wedge was the frequent type, followed by endplate and crush. Multiple logistic regression analysis showed that the odds of back pain was 3.0 (95% CI 1.5-6.3) times higher for women with a single wedge deformity and 3.2 (95% CI 1.0--0.6) times higher for women with two or more wedge deformities, compared to women with no wedge deformity. Vertebral osteoarthritis was associated with back pain (OR 1.8, 95% CI 1.1-2.9), independent of other covariates including age and deformities.

CONCLUSION

Our results in this group of Japanese women are similar to and consistent with results reported previously in other populations of Japanese and Caucasians.

Current-induced magnetic domain wall motion below intrinsic threshold triggered by Walker breakdown

Controlling the position of a magnetic domain wall with electric current may allow for new types of non-volatile memory and logic devices. To be practical, however, the threshold current density necessary for domain wall motion must be reduced below present values. Intrinsic pinning due to magnetic anisotropy, as recently observed in perpendicularly magnetized Co/Ni nanowires, has been shown to give rise to an intrinsic current threshold J(th)(0). Here, we show that domain wall motion can be induced at current densities 40% below J(th)(0) when an external magnetic field of the order of the domain wall pinning field is applied. We observe that the velocity of the domain wall motion is the vector sum of current- and field-induced velocities, and that the domain wall can be driven against the direction of a magnetic field as large as 2,000 Oe, even at currents below J(th)(0). We show that this counterintuitive phenomenon is triggered by Walker breakdown, and that the additive velocities provide a unique way of simultaneously determining the spin polarization of current and the Gilbert damping constant.

Tunnel magnetoresistance effect and magnetic damping in half-metallic Heusler alloys

Some full-Heusler alloys, such as Co(2)MnSi and Co(2)MnGe, are expected to be half-metallic ferromagnetic material, which has complete spin polarization. They are the most promising materials for realizing half-metallicity at room temperature owing to their high Curie temperature. We demonstrate a huge tunnel magnetoresistance effect in a magnetic tunnel junction using a Co(2)MnSi Heusler alloy electrode. This result proves high spin polarization of the Heusler alloy. We also demonstrate a small magnetic damping constant in Co(2)FeAl epitaxial film. The very high spin polarization and small magnetic constant of Heusler alloys will be a great advantage for future spintronic device applications.

Long-lived ultrafast spin precession in manganese alloys films with a large perpendicular magnetic anisotropy

Spin precession with frequencies up to 280 GHz is observed in Mn(3-δ)Ga alloy films with a perpendicular magnetic anisotropy constant K(u)∼15  M erg/cm(3). The damping constant α, characterizing macroscopic spin relaxation and being a key factor in spin-transfer-torque systems, is not larger than 0.008 (0.015) for the δ=1.46 (0.88) film. Those are about one-tenth of α values for known materials with large K(u). First-principles calculations well describe both low α and large K(u) for these alloys.

Large voltage-induced magnetic anisotropy change in a few atomic layers of iron

In the field of spintronics, researchers have manipulated magnetization using spin-polarized currents. Another option is to use a voltage-induced symmetry change in a ferromagnetic material to cause changes in magnetization or in magnetic anisotropy. However, a significant improvement in efficiency is needed before this approach can be used in memory devices with ultralow power consumption. Here, we show that a relatively small electric field (less than 100 mV nm(-1)) can cause a large change (approximately 40%) in the magnetic anisotropy of a bcc Fe(001)/MgO(001) junction. The effect is tentatively attributed to the change in the relative occupation of 3d orbitals of Fe atoms adjacent to the MgO barrier. Simulations confirm that voltage-controlled magnetization switching in magnetic tunnel junctions is possible using the anisotropy change demonstrated here, which could be of use in the development of low-power logic devices and non-volatile memory cells.

Widespread activation of the brainstem preceding the recruiting rhythm in human epilepsies

The excitability change of the brainstem was investigated before and during the conspicuous epileptic discharge in six patients with generalized convulsive seizures. The discharge consisted of a short duration of recruiting rhythm, which was considered equivalent to the seizure discharge on electroencephalogram. The excitability of the brainstem was measured with the parameters (amplitude and area) of component waves (wave-III and -V) of brainstem auditory evoked potentials. The theoretical background of the analysis is that brainstem auditory evoked potentials are 'far-field' potentials, by which they convey the information on the activity change of the brainstem even during the paroxysmal discharge within the cortex. The excitability of both the ventral (parameters of wave-III) and the dorsal brainstem (parameters of wave-V) exhibited a synchronized change (activation-inactivation). They were enhanced from -2.4+/-0.4 s, reaching the maxima before the onset of the seizure discharge, and decayed corresponding to the emergence of the recruiting rhythm. The results suggest the possibility that the widespread (ventral and dorsal) and synchronized activation of the brainstem triggers the seizure discharge in human generalized epilepsy. During the widespread activation of the brainstem, both the thalamus and the cortex probably undergo a suppressed inhibitory state through the cholinergic activation, precipitating the seizure discharge.

Brainstem activates paroxysmal discharge in human generalized epilepsy

In nine patients with generalized epilepsy of convulsive seizures, the excitability change of the brainstem was evaluated over the course of the interictal paroxysmal discharge (poly spike-and-wave complex, poly SWC). The evaluation was carried out by a sequential analysis of brainstem auditory evoked potentials (BAEPs) before and during one sequence of poly SWC. The characteristics of BAEPs, i.e. far-field evoked potentials, allowed the evaluation of the excitability change in the brainstem, which was not influenced by the cortical activity. The excitability in the ventral brainstem, measured with the parameters of wave-III, showed a biphasic fluctuation (deceleration--acceleration) before the onset of poly SWC (minima at -0.7+/-0.4 s). On the other hand, the excitability in the dorsal brainstem, measured with the parameters of wave-V, showed no significant difference over the course of poly SWC. The results suggest that the biphasic excitability change in the ventral brainstem is conveyed to the cortex through the ascending activating system. The excitability acceleration preceded by deceleration in the ventral brainstem probably synchronizes the cortical activity profoundly enough to produce poly SWC through the activation of intralaminar thalamic neurons.

Diverse biological activities of moxa extract and smoke

Diverse biological activities of moxa extracts and smoke (gas phase) were investigated. Moxa was extracted with hot water (Fr. I), or ethanol (Fr. II), or extracted with hot water after ethanol wash (Fr. III) and then lyophilized to obtain the dried powders. Moxa smoke (containing a lot of gaseous components obtained by burning Moxa) (Fr. IV) was collected into phosphate-buffered saline and quantified spectrophotometrically. These extracts and Moxa smoke showed comparable cytotoxic activity against human oral tumor cell lines (HSC-2, HSG). Human gingival fibroblasts (HGF) were more resistant to any Moxa fractions. Neither of the extracts showed anti-HIV activity. Pretreatment of mice with Fr. I significantly reduced the lethal effect of E. coli infection. All extracts produced radicals under alkaline condition, with a maximum intensity at pH 10.5, and enhanced the radical intensity of sodium ascorbate. It was unexpected that these extracts show significant O2- scavenging activities. These data suggest the medicinal efficacy of Moxa extracts and smoke.

Bilateral four-headed biceps brachii muscles: the median nerve and brachial artery passing through a tunnel formed by a muscle slip from the accessory head

Bilateral four-headed biceps brachii muscles were observed in the dissected cadaver of a 95-year-old Japanese woman. The third head on both sides originated from the humerus at the insertion of the coracobrachialis and inserted into the distal part of the biceps brachii and the proximal part of the common biceps tendon on the ipsilateral side. The fourth head on both sides arose from a thin fibrous origin from the intertubercular sulcus and the insertion of the pectoralis major, and inserted into the confluence of the biceps brachii and the third head. This anomaly is relatively rare. Moreover, the left third head gave off a muscle slip into the posterior fascia of the pronator teres, forming a tunnel. The median nerve and the brachial artery passed through the tunnel, where the nerve and artery seemed to be compressed. The possible production of clinical symptoms, given the anatomy, is discussed.

Posterior sinus node artery and accessory atrioventricular node artery arising by a common origin: a case report

We describe herein a rare and hitherto not reported variation, found in a Japanese male cadaver, in which a posterior sinus node (SN) artery and an accessory atrioventricular node (AN) artery originate from a common trunk branching from the posterior segment of the circumflex artery. After arising in this manner, the posterior SN artery passed in a clockwise direction around the posterior, lateral, and finally anterior wall of the left atrium to the sinus venosus, giving off a branch to the SN from posteriorly. The accessory AN artery coursed in a counterclockwise direction on the posterior wall of the left atrium as far as the crux of the heart, where it bent anterosuperiorly and continued within the interatrial septum. It entered the AN from superiorly and, crossing deep to the principal AN artery, reached the inferior and superficial portion of this node. It could be considered that the accessory AN artery in this study is a modified version of arteries entering and coursing in the interatrial septum, as exemplified by Kugel's anastomotic artery.

Anomalous triad of a left-sided inferior vena cava, a retroesophageal right subclavian artery, and bilateral superficial brachial arteries in one individual

We report a rare case of three major vascular variations in the same individual, two within the thorax and abdomen and one within the upper extremity. The observations were made in a cadaver of a 74-year-old Japanese woman. A single left-sided inferior vena cava was observed that began from the confluence of the left and right common iliac veins and ascended vertically to the left side of the abdominal aorta. After receiving the left renal vein, it passed obliquely upward anterior to the abdominal aorta, reaching the right side of the aorta, and then ascended vertically to the right atrium, following its normal course. The retroesophageal right subclavian artery was also present; it arose from the arch of the aorta as the last branch, passing obliquely between the esophagus and the vertebral column. Thus the right recurrent laryngeal nerve was not formed. Additionally, bilateral superficial brachial arteries were observed. They arose from the axillary artery, crossed over the medial root of the median nerve, coursed down the arm, and divided into the radial and ulnar arteries in the cubital fossa. Although each variation is not rare by itself, the triad of events is rare and important to clinicians, anatomists, and medical students.

Are high barometric pressure, low humidity and diurnal change of temperature related to the onset of asthmatic symptoms?

BACKGROUND

Meteorologic factors play a role in the expression of asthmatic symptoms; however, there are controversies about the causal relationship between meteorologic factors and asthma. The relationship between meteorologic parameters and emergency admissions for asthmatic symptoms in this hospital were analyzed.

METHODS

A total of 205 patients (130 boys and 75 girls, 0.1-16.6 years of age) who were admitted to Hakodate Chuo General Hospital for asthmatic symptoms between 1 January and 31 December 1997 were submitted to our study. We divided a total of 365 days into two groups of days with and without any admissions. Meteorologic factors for the days with admissions and 1-3 days before hospitalization were compared with those of the days of no admissions. Statistical analysis was done with the Mann-Whitney U-test.

RESULTS

On the days with admissions and 1 day before hospitalizations, barometric pressure was higher and relative humidity lower than on days with no admissions. The diurnal difference between maximum and minimum temperature for days 1 day before days with admissions was larger than that for 1 day before days with no admissions.

CONCLUSIONS

It is thought that change in barometric pressure, relative humidity and temperature had some influence on the worsening of asthmatic symptoms.

Time-course changes of eosinophil counts in premature infants: no effects of medical manipulation, except erythropoietin treatment, on eosinophilia

In order to determine the factors responsible for eosinophilia during the neonatal period, we counted the eosinophils of premature infants every week and compared the medical profiles of infants with eosinophil counts above the 95th percentile and those below that percentile during the course of study. Medical treatments such as mechanical ventilation, antibiotics administration and intravenous catheterization had no significant effects on the increase of eosinophils. Furthermore, the incidence of eosinophil counts above the 95th percentile was not different between breast-fed and formula-fed infants. The infants treated with erythropoietin had greater eosinophil counts than those with no treatment. It is probable that medical manipulation using foreign bodies such as intratracheal tube, intravenous catheter, antibiotics and artificial formula had no significant effects on the increase of eosinophil counts, except for exogenous erythropoietin.

[Energy metabolism in the cerebrum and the brainstem-cerebellum of the rat brain under hypoxic conditions]

The relationship between neuronal activity, intracellular oxygenation and energy metabolism in the cerebrum and the brainstem-cerebellum of the rat brain in graded hypoxia was studied. Intracellular oxygenation was monitored by near-infrared measurement of the redox state of cytochrome oxidase (cyt.ox.). Neuronal activity was assessed by EEG (electroencephalography) and the evoked potentials (VEP; visual, BSR; brainstem, C-SEP; cortical-sensory, S-SEP; spinal-sensory evoked potentials). As hypoxia progressed, neuronal activities disappeared in the order of VEP, C-SEP, EEG, BSR, S-SEP. However, intracellular oxygenation at the disappearance of each neuronal activity was significantly lower in the brainstem-cerebellum than in the cerebrum. ATP (adenosine triphasphate), glucose, and lactate were measured in the cerebral cortex, subcortex, brainstem, and cerebellum 1-2 minutes after the disappearance of neuronal activities on EEG. Hypoxia caused decreases in ATP in each brain region. Marked increases in lactate were observed in each brain region, though the degree of increment was less in the cerebral cortex than the other brain regions. A decrease in glucose was observed only in the cerebral cortex. These results suggest that by the use of the energy generated via glycolysis, the brainstem functions even after oxygen supply has been significantly reduced, while the neuronal activity in the cerebrum is suppressed at the higher oxygenation level than that in the brainstem-cerebellum. It is, thus, supposed that these differential responses of brainstem and cortical neurons to oxygen deprivation are inherent, and critical for neuronal survival in severe hypoxia.

[The effect of olprinone administered after cardio-pulmonary bypass during open heart surgery, evaluated by its plasma concentrations and hemodynamic changes]

Plasma concentrations and hemodynamic effects of olprinone were evaluated in seventeen patients undergoing open heart surgery. The patients were randomized into the bolus group (15 micrograms.kg-1 bolus dose +0.1 microgram.kg-1.min-1 infusion, n = 9) and the non-bolus group (0.1 microgram.kg-1.min-1 infusion, n = 8). Plasma concentrations and hemodynamic variables were measured before CPB (cardiopulmonary bypass; baseline), 5, 60 min after weaning from CPB, and 3, 6 hours after the end of surgery. Plasma concentrations in the non-bolus group were significantly lower than those of bolus group at any point except for 3 hours after the end of surgery. In the bolus group, increases in the cardiac index and stroke volume index were significantly higher compared with the non-bolus group. From these results we conclude that olprinone given in bolus (15 micrograms.kg-1) followed by continuous infusion (0.1 microgram.kg-1.min-1) is efficacious and safe during weaning from CPB.

Brainstem triggers absence seizures in human generalized epilepsy

Simultaneous analysis of brainstem auditory evoked potentials (BAEPs) with reference to electroencephalography (EEG) was designed to examine the brainstem function corresponding to the EEG event. With this method, we investigated the brainstem function pre- and during the paroxysmal discharge in human absence seizures classified as primary generalized epilepsy (PGE). Two types of functional change in the lower brainstem were revealed as parameters of wave-III components (amplitude and area) of BAEPs without significant change in the upper brainstem. One was long-range biphasic fluctuation (acceleration followed by abrupt deceleration with the maximum -6.4+/-3.2 s before the seizure onset), and the other was rhythmic oscillation with 3 Hz. The latter, synchronized with the cortical spike-and-wave complex, imposed on the descending slope of the former. One important point is that both preceded the onset of cortical paroxysmal discharge. The results reappraise the classical hypothesis of "centrencephalic system" on seizure generating mechanism in human PGE. The results prove the primary triggering role of the lower brainstem that is independent of sleep-related synchronizations. The method is applicable to other types of EEG event for the investigation of brainstem involvement.

Imaging of caspase-3 activation in HeLa cells stimulated with etoposide using a novel fluorescent probe

Microscopic visualization of intracellular enzyme activity can provide information about the physiological role of the enzyme. Caspases are cysteine proteases that have critical roles in the execution of apoptosis. General fluorometric substrates of caspase-3, such as DEVD-MCA, are unsuitable for imaging because they are excited at short wavelength, so we designed and synthesized novel fluorescent probes that are excited at suitable wavelengths for detecting caspase-3 activity in living cells. Using one of these probes, we succeeded in microscopic visualization of caspase-3-like activity within HeLa cells treated with etoposide. The caspase-3-like activity was increased in the cytosol at first, then expanded to the whole cell.

Superficial ulnar artery originating from the brachial artery and its clinical importance

We found a left superficial ulnar artery in the cadaver of a Japanese woman. This anomalous vessel originated from the brachial artery at a site 55 mm distal to the inferior border of the teres major muscle and medial to the median nerve, ran downward and medially superficial to the forearm flexor muscles, and then downward to enter the hand. It formed superficial and deep palmar arches with the radial artery. The clinical importance of the anomalous ulnar artery is discussed.

A metopic suture observed in a 91-year-old Japanese male

We encountered a complete ectometopic suture in a 91-year-old Japanese male cadaver during a gross anatomy course. It was observed in one of 26 skulls aged from 62 to 92 years and was about 13 cm in length from the bregma to the nasion. It is rare to encounter the metopic suture in a person of advanced age, as in the present case.

Duplication of the inferior vena cava: two case reports

We encountered two cases of duplication of the inferior vena cava (IVC) in the Japanese cadavers of a 91-year-old man and a 71-year-old woman. Both of the anomalies were classified as Type BC and as Type I according to the systems of Chuang et al. (1974) and of Sarma (1966), respectively. In one case the right IVC was twice the diameter of the left IVC, and in the other it was five times as large. We discuss the clinical importance and the development of duplication of the IVC.

Branches of the vagus nerve destined for the heart and the adjoining great vessels in the house shrew, Suncus murinus, with reference to the terminology of the vagal cardiac branches

In order to help to organize the understanding of the bewildering complexities of the innervation of the mammalian heart by the vagus nerve and to clear up of confusions as regards the vagus cardiac branches, we scrutinized these branches in the adult house shrew, Suncus murinus, under a stereomicroscope. A number of branches were given off from the vagus nerve not only to the heart, but also to the adjoining great vessels, both outflowing and inflowing. When compared from the developmental viewpoint, the basic conformations of these branches on two sides were found not to differ from each other, but rather presented a symmetrical configuration, the feature which has been ascertained also in mammalian embryos. Relying on developmental criteria, we classified them into the arterial porta-related and the venous porta-related groups, formulating a new terminology by naming them on the basis of their destination. This version of terminology allowed us to define the vagus cardiac branches of the house shrew more accurately than the current terminology (e.g., Nomina Anatomica), and seems to provide us a clue for clearing up confusions concerning the terminology of the vagus cardiac branches in mammals.

Two rare anomalies of the brachial plexus

Morphological variations of the brachial plexus and variants in the distribution of the anterior division of the middle trunk are relatively frequent. Two of the rarest anomalies occurred in the left brachial plexus of a 62-y-old Japanese male, 1 of 104 plexuses dissected between 1996 and 1997 at Kanazawa University Faculty of Medicine. The superior trunk of the brachial plexus was formed by the anterior primary division of C5 and C6 and a thin branch (0.5 mm in diameter) from C4, the middle trunk by the C7, and the inferior trunk by C8 and T1 (Fig.). We could not determine whether there was a branch derived from T2 to T1, since the subject had died of lung carcinoma. The entire anterior division of the middle trunk crossed the axillary artery and joined the medial root of the median nerve which was the continuation of the medial cord after the cord branched off the ulnar nerve. The lateral cord pierced coracobrachialis and divided into the musculocutaneous nerve and the lateral root of the median nerve just after emerging from the muscle, finally joining the medial root of the median nerve superficial to the brachial artery ∼115 mm distal to the lower border of latissimus dorsi to form the median nerve. The musculocutaneous nerve gave rise to the nerves to biceps brachii, brachialis, and the long head of biceps brachii and finally continued as the lateral cutaneous nerve of the forearm. The branch to coracobrachialis had already been cut and its course could not be traced.

Absence of the musculocutaneous nerve with innervation of coracobrachialis, biceps brachii, brachialis and the lateral border of the forearm by branches from the lateral cord of the brachial plexus

Anomalies of the brachial plexus and its terminal branches are not uncommon. Variations in the course and branches of the musculocutaneous nerve have been noted (Clemente, 1985; Bergman et al. 1988) and its absence was reported by Le Minor (1990). Several anomalies were present in the left plexus of a 59-y-old Japanese man (Fig.). There were no anterior and posterior divisions of the middle trunk, although there were communications between the posterior, medial and lateral cords. The musculocutaneous nerve was absent (Le Minor, 1990) and the medial and lateral roots of the median nerve did not unite in the axillary fossa but in the upper arm about 5 cm distal to the lower border of latissimus dorsi (Adachi, 1928; Buch-Hansen, 1955). The hitherto unreported findings were branches arising directly from the lateral cord to supply coracobrachialis, both heads of biceps brachii and brachialis. The lateral cutaneous nerve of the forearm was derived from the lateral cord with a small contribution from the medial root of the median nerve. Since there were communications between the posterior cord (a continuation of the middle trunk) and the medial and lateral cords, it is theoretically possibly, but not proven, that the root values of branches innervating the flexor muscles of the arm and forearm and the skin of lateral border of the forearm were normal.

Right superior bronchial artery arising from the right subclavian artery and accompanying nerve branches: an autopsy case

In one out of 8 examined cadavers a solid, right superior bronchial artery was found to arise from the subclavian artery with its origin at the same level as those of the right vertebral and internal thoracic arteries. This bronchial artery was 1.5 mm in caliber and closely associated with the right sinal nerve arising from the vagus nerve and with the right stellate cardiopulmonary nerves arising from the right stellate ganglion. Such a close association was also observed between other sympathetic cardiac nerves and bronchial arteries and an extracoronary artery. On the basis of these observations it was deduced that the general course of the bronchial arteries serves to pave the way for the extension of the sympathetic cardiac nerves to the heart.

Aberrant branch of the superior laryngeal nerve passing through the thyroid foramen: a macroscopical study

This is the first report providing detailed description on an aberrant branch (AB) which, arising from the superior laryngeal nerve (LN), passes through the thyroid foramen and is distributed to the mucous membrane of the larynx. The foramen was observed in 7 out of 14 Japanese cadavers examined in this study, 3 on the right, 3 on the left and one on both sides. In these 7 sides, the AB was given off from the external branch of the superior laryngeal nerve (LN) during its descent on the inferior constrictor muscle of the pharynx. In one side, however, it arose from both the external and internal branches of the superior LN. In each case, the AB, after passing through this foramen, reached the lateral aspect of the arytenoid cartilage, dividing into a superior and an inferior division. The superior one was communicated with a branch of the internal branch of the superior LN, while the inferior one was communicated with that of the inferior LN of the recurrent LN. The joined branches were distributed to the mucous membrane covering the ventricle of the larynx and the vocal fold. On the basis of the height of its distribution, it can be mentioned that the AB is situated intermediate in position between the internal branch of the superior and inferior LNs.

Superficial brachial artery continuing as the common interosseous artery

The superficial artery of the arm with a course anterior to the median nerve is found at an incidence of ≈13%, and it continues as the radial artery twice as frequently than as the ulnar artery; less frequently it continues as both arteries (Bergman et al. 1988). We report a rare case in which the superficial brachial artery continued as the common interosseous artery only and the deep brachial artery continued as the radial and superficial ulnar arteries in the cubital fossa.

Three cases of the musculocutaneous nerve not perforating the coracobrachialis muscle

We encountered three anomalies in which the musculocutaneous nerve did not penetrate the coracobrachialis during a gross anatomy course in 1996. Two of the anomalies were present in the bilateral arms of the cadaver of an 89-year-old woman, and the other in the right arm of the cadaver of a 64-year-old man. In all of the anomlies the musculocutaneous nerve, the lateral cord of the brachial plexus, and the median nerve were contained in a common sheath of connective tissue. Thus, muscular branches to the flexor muscles of the upper arm and the lateral antebrachial cutaneous nerve seemed to arise from the cord and the median nerve. After the common sheath was removed, the musculocutaneous and median nerves were completely separated, or the fusion between the musculocutaneous and median nerves only remained partially. These variations are apparently not rare, and it is possible that the combined paralysis of the musculocutaneous and median nerves would occur. The present variation may be important to clinicians.

Peritoneal lymphatic stomata of the diaphragm in the mouse: process of their formation

BACKGROUND

Lymphatic stomata are channels connecting the peritoneal cavity with the lymphatics in the diaphragm. The process of sequential formation of the stomata has not been studied. The objective of this study was to examine the morphogenesis of the lymphatic stomata in mice.

METHODS

Ultrathin sections of diaphragms from ddY mice obtained on embryonic day 18 and postnatal days 0, 4, and 10 were observed with a transmission electron microscope.

RESULTS

By embryonic day 18 and postnatal day 0, lymphatics were already observed in the submesothelial connective tissue on the peritoneal side of the fetal diaphragm. The lymphatic endothelial cells, but not the mesothelial cells covering the diaphragm, protruded short cytoplasmic processes into the submesothelial connective tissue, and these almost reached the basal surfaces of individual mesothelial cells. By postnatal days 4 and 10, the lymphatic endothelial cells frequently protruded cytoplasmic processes into the submesothelial connective tissue, and the endothelial cell processes broke the continuity of both the basal lamina beneath the mesothelial cells and the submesothelial connective tissue. Neighboring endothelial processes formed a pair of U-shaped folds that were connected with each other via intercellular junctions at the apexes of the U-shaped folds. The disassembly of the intercellular junctions between the U-shaped folds was observed, and the basal surface of the mesothelial cell faced the lymphatic lumen. Dehiscence of the intercellular junctions between the mesothelial cells overlaying the lymphatics was observed, and lymphatic stomata were present. On the pleural side of the diaphragm, lymphatics were already present on embryonic day 18, but it was not observed that the endothelial process spanned the submesothelial connective tissue to the basal surface of the mesothelial cell.

CONCLUSIONS

These results suggest the following process of the formation of the lymphatic stomata. (1) Neighboring lymphatic endothelial cells span the submesothelial connective tissue to the basal surfaces of mesothelial cells. (2) The lymphatic stomata are formed by the disassembly of the intercellular junctions between the neighboring endothelial cells and between the mesothelial cells overlying the endothelial cells.

A variant branch of the internal laryngeal nerve supplying filaments to the cricothyroid muscle: an autopsy case

We report a variant branch of the internal laryngeal nerve found in a Japanese male body. This branch, arising in the piriform fossa from the inferior portion of the loose network formed by the intercommunicating subbranches of the internal laryngeal nerve, descended in the interval between the thyroid and arytenoid cartilages accompanied by a branch of the superior laryngeal artery as far downward as the lowest portion of the thyroid cartilage. Here it crossed lateral to the inferior laryngeal nerve to which it gave off a communicating branch and reached the deep surface of the cricothyroid muscle. In this muscle it split into several divisions, each of which issued filaments to this muscle. The terminal branch of this variant branch ended in the fascia covering the cricothyroid muscle and the cricoid cartilage.

[Cryopreservation of bone marrow and peripheral blood stem cells using a controlled rate freezing system: experience with 86 procedures]

The cryopreservation of hematopoietic stem cells can be used for rescuing the hematopoiesis after high dose chemotherapy.

PURPOSE

The ice crystal formation during the freezing procedure is the key point that can be harmful to the cells. The cryopreservation of hematopoietic stem cells in a controlled-rate freezer could decrease the cell damage.

METHODS

Twenty-three patients with a median age of 26 years (range 03-57) had bone marrow and/or peripheral blood stem cells harvested from March 1993 through October 1994, ending up to 86 freezing procedures. The patient's diagnoses are as follows: Non-Hodgkin's Lymphoma (n = 5); Acute Myelogenous Leukemia (n = 8); Acute Lymphocytic Leukemia (n = 6); Hodgkin's disease (n = 3); Multiple Myeloma (n = 1). The cells were frozen away in a controlled-rate freezer chamber at the following rate: -1 degree C/min from room temperature to -45 degrees C and then, at -10 degrees C/min down to -80 degrees C. After freezing, the cells were kept into mechanical freezers until the marrow infusion. To mobilize PBSC (peripheral blood stem cells), G-CSF (granulocyte colony stimulating factor) was given.

RESULTS

A median of 3.16 x 10(8) cells/kg (range 0.86-24.22) of PBSC and 2.03 x 10(8) cells/kg (0.19-12.21) of bone marrow cells were frozen. The median time to reach granulocytes greater than 500/microL and platelets greater than 20,000/microL was 12 days (range 8-40) and 31 days (range 8-80), respectively. All patients had marrow engraftment after infusion of hematopoietic stem cells.

CONCLUSION

The cryopreservation procedure using a controlled-rate freezer can store hematopoietic stem cells and potentially, cause less damage to the cells.

A rare case: the medical cord of the brachial plexus sandwiched between the axillary and superficial brachial arteries

We encountered a rare anomaly in the cadaver of a Japanese woman in the medical cord of the brachial plexus including the ulnar nerve and the medical root of the median nerve was sandwiched with the axillary and the superficial brachial arteries. The axillary artery passed inferior and dorsal to the medial cord, branching off the subscapular, anterior circumflex humeral arteries, and the common trunk of the posterior circumflex humeral and profunda brachii arteries, and ended as the inferior ulnar collateral artery. The superficial brachial artery descended ventral to the median nerve and divided into the radial and ulnar arteries in the cubital fossa. We discuss the developmental formation of this anomaly.

Case report: bilateral location of the axillary artery posterior to the medial cord of the brachial plexus

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An autopsy case of an extracoronary artery presenting evidence for the dualism of blood supply to the human heart

In an anatomy class, dissection of a cadaver led to the discovery of a hitherto not reported extracoronary artery found to take part in supplying blood to the heart of a Japanese male. This artery arose from the concavity of the aortic arch and coursed as far downward as the level of the bifurcation of the pulmonary trunk, dividing here into the arterial porta- and venous porta-related arteries; the latter obviously supplied the atrial portion of the heart. It is believed that this artery is a variant of the bronchial artery.

Superficial brachial arteries observed in bilateral arms

We describe rare anomalies of the bilateral superficial brachial arteries in a dissected 69-year-old Japanese man in the gross anatomical course. The right and left superficial brachial arteries were observed to originate from the axillary artery, pass over the lateral root of the median nerve, course laterally and superficially to the median nerve, and split into the radial and ulnar arteries in the cubital fossa. The right brachial artery ended in the posterior aspect of the elbow. The left brachial artery ended in the anastomosis with the ulnar artery at the site opposite to the origin of the common interosseous artery. These arterial patterns can be explained by the existence, during the developmental process of the arteries of the arm, of a superficial brachial artery and an anastomotic branch between the superficial brachial and brachial arteries.

Retroesophageal right subclavian artery originating from the aortic arch distal and dorsal to the left subclavian artery

In the cadaver of a Japanese 79 year-old man a retroesophageal right subclavian artery was observed to be derived from the arch of the aorta slightly distal and dorsal to the left subclavian artery. Its origin formed Kommerell's arterial diverticulum (50 mm in circumference), and it passed between the esophagus and the vertebral column and continued to the right to become the axillary artery. No right recurrent laryngeal nerve was observed. There was a right ansa subclavia around the subclavian artery. Although this anomaly is relatively rare, it is important as a cause of dysphagia lusoria.

The superficial ulnar artery originating from the axillary artery

An anomalous superficial ulnar artery was found during anatomical dissection in the right arm of an 83-year-old Japanese woman. It originated in the axillary artery, crossed over the median nerve, coursed ventral to the median nerve and the brachial artery, but superficial to the bicipital aponeurosis and the flexor muscles. At the palm it formed the superficial and deep palmar arches together with the branches of the radial artery. The brachial artery divided into the radial and common interosseous arteries in the cubital fossa.

[Anesthetic management for cesarean section in patients with maternal myotonic dystrophy]

Myotonic dystrophy involves not only voluntary muscles of extremities, pharyngeal muscle and respiratory muscle but also smooth muscle in the gastrointestinal tract. This muscle involvement can cause difficulty in excreting sputa, delayed emptying time of stomach and regurgitation of gastric content, all of which can lead to disastrous complications of anesthetic management. Pregnancy is rare because of ovarian atrophy. We report two cases of cesarean section for patients with myotonic dystrophy. In one case, the newborn baby had dyspnea due to congenital myotonic dystrophy, and in another case, patient experienced postoperative pneumonia. Our cases and other reports suggest that spinal or epidural anesthesia is safely applied for a cesarean section of a patient with myotonic dystrophy.

Studies on the inferior phrenic vein of rats: the probability of its being a collateral route of blood from the lower portion of the body to the heart

The principal aim of this study was to elucidate key features of the inferior phrenic vein (IPV) of adult rats to determine whether the IPV has the potential to function as a collateral return route conveying blood from the lower portion of the body to the heart, bypassing the subhepatic vein segment of the inferior caval vein. In rats, the IPVs on both sides were found to reveal a symmetric appearance. They were both composite vessels, being made up of two fellow subvessels, the sternocostal and the lumbocostal veins, which in turn anastomosed in tandem in their periphery with each other, formed a collateral route bridging the interval between the suprarenal and the hepatic vein segments of the inferior caval vein. In rat embryos of E17.5, the sternocostal and lumbocostal veins of the IPV were observed to have been well developed, forming tandem anastomoses more clearly than in adults, thus connecting the subcardinal vein to the hepatic vein segment of the inferior caval vein. This fact substantiates our supposition that the rat's IPV originally has the potential to act as a collateral returning route which allows blood to bypass the subhepatic vein segment of the inferior caval vein.

Dynamic features of hemodynamic and metabolic changes in the human brain during all-night sleep as revealed by near-infrared spectroscopy

By the use of near-infrared spectroscopy, hemodynamic and metabolic changes were monitored continuously in the human brain during all-night sleep in a similar time dimension as closely monitored by electroencephalography. Measurements were started in the awake state, the values of which were taken as the control. Contrary to what many have predicted, the cerebral oxygen metabolic rate (CMRO2) increased during the transition from wakefulness to sleep. Cerebral blood flow (CBF) decreased during non-rapid eye movement (non-REM) sleep, in which a dissociation between changes in CBF and those in CMRO2 was observed. The CBF returned to the control level even in response to the only 20-s appearance of alpha activity on the electroencephalogram. During REM sleep both CBF and CMRO2 were practically the same as the control level, whereas during the transition from REM sleep to arousal a disproportionate increase in CBF compared with CMRO2 was observed. Thus, it is suggested that the flow-metabolic coupling mechanism is reset to a new level during sleep.