Dual-modality imaging of function and physiology

Dual-modality imaging is a technique in which computed tomography (CT) or magnetic resonance imaging is combined with positron emission tomography or single-photon emission CT to acquire structural and functional images with an integated system. The data are acquired in a single procedure; the patient remains on the scanner table while undergoing both x-ray and radionuclide studies to facilitate correlation between the structural and functional images. The resulting data can aid in localization, enabling more specific diagnosis than can be obtained with a conventional imaging study. In addition, the anatomic information can be used to compensate the correlated radionuclide data for physical perturbations such as photon attenuation, scatter radiation, and partial volume errors. Thus, dual-modality imaging provides a priori information that can improve both the visual quality and the quantitative accuracy of the radionuclide images. Dual-modality imaging systems are also being developed for biologic research involving small animals. Small-animal dual-modality systems offer advantages for measurements that currently are performed invasively with autoradiography and tissue sampling. By acquiring data noninvasively, dual-modality imaging permits serial studies in a single animal, enables measurements to be performed with fewer animals, and improves the statistical quality of the data.     

The relationship of the anterior drawer sign to the shape of the tibial plafond in chronic lateral instability of the ankle

To determine what factors correlate with values for tested anterior drawer (AD) sign, we investigated stress radiographs in 71 patients with severe chronic lateral instability of the ankle as well as 320 normal controls. We found no correlation between AD and talar tilt (TT), but measurement of the anterior tip ratio (ATR) (ATR=tanA x 100) demonstrated a link of ATR with AD (r=0.74, p<0.001). The posterior tip ratio (PTR) (PTR=tanP x 100) was not correlated with AD (r=0.34, p=0.16). The ankle mortise angle (AMA) (the anterior opening of the lateral ankle mortise) was also not correlated with AD (r=0.27, p=0.23). Investigation of 320 normal ankles revealed a mean ATR of 9.1%+/-1.4%. The ATR in patients was 7.6%+/-1.7%, significantly lower than in the control patients. The values in female patients with chronic lateral instabilities were significantly less than the values in the females in the control group. But values for male patients were not different from the control group. Thus the anterior tip of the lateral tibial plafond, as it affects the ATR, may influence instability in anterior drawer function, especially in female patients with chronic lateral ligamentous instability of the ankle.     

Total hip arthroplasty for a patient with angel-shaped phalango-epiphyseal dysplasia (ASPED). A case report

Angel-shaped phalango-epiphyseal dysplasia is characterized by the angel shape of the middle phalanx and severe coxarthrosis in adult life. This osteochondrodysplasia shows a further variety of heterogeneous multiple epiphyseal dysplasias. It also shows a late and dysplastic development of the femoral head that leads to osteoarthrotic changes with severe hip pain and gait disturbance. In this report, we show a 35-year-old female with Angel-shaped phalango-epiphyseal dysplasia that was treated by bilateral total hip arthroplasty. She has suffered from her coxalgia since she was 27 and since the age of 30 has been able to walk with the aid of crutches. The radiographs of her bilateral hip showed severe osteochondrotic changes with a progressive disappearance of the joint space. Total hip arthroplasties were performed to treat the osteoarthrosis on the bilateral hip joint due to Angel-shaped phalango-epiphyseal dysplasia. One year after surgery, she is pain-free, and able to walk with a cane. Based on this case, we propose that total hip arthroplasty should be considered one of the treatments for the coxopathy in patients with Angel-shaped phalangoepiphyseal dysplasia.     

Physicochemical quality evaluation of natural compounds isolated from crude drugs

Aconite root has high toxicity caused by diester alkaloids, thus it was necessary to define the limiting value of diester alkaloids used in medicine formulation. To give the quality of “Processed Aconite Root” and “Powdered Processed Aconite Root” in the Japanese Pharmacopoeia (14th edn, supplement II), we established the official specification and evaluation methods of standard substances. High qualitative grade diester alkaloids, aconitine, hypaconitine, jesaconitine and mesaconitine, which were useful to evaluate the purity of processed aconite root and powdered processed aconite root, were prepared and evaluated for their stability. We studied the physicochemical specification and evaluation methods of these alkaloids. In addition, an “Aconitum diester alkaloids standard solution for purity”, which was used for the purity test, was prepared, and we also studied its physicochemical specification and evaluation methods. In addition, to evaluate the quality of processed aconite root and powdered processed aconite root, a TLC identification test was established. A monoester alkaloid of benzoylmesaconine hydrochloride was used as the reference standard in the latter test, and we also investigated its physicochemical specification and evaluation methods.     

The utility of the microcrystalline cellulose sphere as a particulate embolic agent: an experimental study

BACKGROUND AND PURPOSE: Although various particulate materials have been developed as embolization agents, their biocompatibility remains unclear. We used an animal model to examine the possibility of using FDA-approved microcrystalline cellulose spheres (CELPHERE) as solid embolic material for the permanent occlusion of blood vessels. METHODS: Angiographic and histologic studies in 12 canine renal arterial systems were conducted to evaluate the performance of CELPHERE beads at 1 hour, and at 4 and 12 weeks after embolization. RESULTS: The CELPHERE beads traveled to vessels with diameters approximating their own. Larger vessels were occluded by aggregations of beads. There was no disruption of vessel walls and no evidence of perivascular hemorrhage or inflammatory changes. CONCLUSION: Because CELPHERE beads are easy to handle, highly biocompatible, and have few adverse effects, they are suitable for intravascular applications.     

Deafness induced up-regulation of GluR2/3 and NR1 in the spiral ganglion cells of the rat cochlea

Expressions of AMPA (GluR2, GluR3, and GluR4) and NMDA (NR1 and NR2) glutamate receptors in the spiral ganglion cells of the cochlea were analyzed both at protein and mRNA levels in control and deaf rats between week 0 (P14) and week 8 (P70) after deafness induced by a daily injection of kanamycin at P0-P14. In the deaf rats, significant up-regulations of GluR2, GluR3, and NR1 in the surviving spiral ganglion cells were observed, while expressions of GluR4 and NR2 were fairly constant. In contrast, in the control rats, the expressions of all these glutamate receptor subtypes were stable. These results suggest that drastic alterations in the diversity of GluR2/GluR3/NR1 receptor complexes in the surviving spiral ganglion cells, which result in alterations in Ca2+ permeability, may contribute to the deafness-related alterations in the structure and function of the cochlea.     

Study of the radioprotective effects of TMG on teratogenic malformations in irradiated mice

ICR mice fetuses in the organogenesis stage were used to clarify experimentally the mechanism of the protective effect of vitamin E derivant (TMG: 2-(alpha-D-Glucopyranosyl) methyl-2, -5, -7, -8-Teramethylchorman-6-working woman) on the effects of radiation. The authors paid careful attention to radiation, and the radioprotective effects of TMG on the induction of malformations was examined. Radiation is an important consideration because of its widespread use in the areas of medicine, nuclear energy, and industry. Malformations induced by radiation at the organogenesis stage, skeletal malformations, and the effects at the cellular level of embryos were examined in this research. Further, the mechanism of the protection effect of TMG against radiation-induced malformations was analyzed and observed experimentally. Thus, this study was done to provide fundamental data on the radioprotective agent TMG. It was clear that TMG exerted radioprotective effects against embryonic death and the rate of teratogenesis when administered before exposure. Such effects were also exerted against skeletal malformations and fetal body weight. In summary, radioprotective effects were observed at the whole-body level as well as at the cellular level.     

Effect of mental stress on left ventricular ejection fraction and its relationship to the severity of coronary artery disease

To evaluate the relationship between the mental stress-induced decrease in left ventricular ejection fraction (LVEF) and the severity of exercise-induced ischaemia, 20 patients with stable coronary artery disease (CAD) underwent radionuclide ventriculography during mental stress testing and stress myocardial perfusion single-photon emission tomography (SPET). We also examined whether changes in haemodynamic and neurohormonal parameters are related to changes in LVEF during mental stress. The LVEF decreased from 54.8% +/- 17.7% to 49.8% +/- 16.2% with mental stress (P < 0.0005). Ten of the 20 patients (50.0%) had a > or = 5% decrease in LVEF The remaining ten patients had no or a <5% decrease in LVEF There was a significant correlation between the change in LVEF during mental stress and the size of the reversible defect on stress myocardial perfusion SPET (r = -0.80, P < 0.0005), with close regional correspondence (75% identical). This correlation was less strong in the 12 patients with a total defect score at rest of <10 (r = -0.69, P = 0.014) than in the eight patients with a total defect score at rest of > or = 10 (r = -0.94, P = 0.001). The changes in blood pressure and heart rate were not significantly correlated with the change in LVEF, but the percent change in adrenaline concentration correlated with the change in LVEE It is suggested that mental stress impairs systolic function by inducing transient myocardial ischaemia. The effect of neurohormonal responses during mental stress on LV systolic function may also be important in patients with CAD.     

Effects of single and repetitive spreading depression on cerebral blood flow and glucose metabolism in cats: a PET study

To clarify the effects of spreading depression (SD) on cerebral circulation and metabolism, we elicited a single or repetitive episode of SD and evaluated CBF and CMRglc three-dimensionally in normal cats (n=4, in each group) using a high-resolution positron emission tomography (PET) scanner. SD was evoked by applying KCl to the left occipital cortex. We then monitored DC potential changes with tungsten electrodes inserted into the left temporal cortex. CBF was measured twice before and three times (immediately, 30-60 min, and 60-120 min) following KCl application using [15O]H(2)O, and CMRglc was determined using 2-[18F]fluoro-2-deoxy-D-glucose immediately following the last CBF measurement. The following results were obtained: (1) a single episode of SD produced a temporary CBF increase, followed by a long-lasting hypoperfusion in the cortex, with no significant changes to CBF observed in the subcortex; (2) no significant CMRglc changes were observed in either cortical or subcortical regions following a single episode of SD; (3) a flow-metabolism uncoupling was observed in the cortical regions concurrently with persistent hypoperfusion; (4) repetitive SD produced significant CBF changes in the cortex; and (5) the cortical CMRglc increased as a result of repeated episodes of SD, with no significant changes observed in the subcortex. Thus, we succeeded in determining three-dimensionally the effects of single and repetitive SD on CBF and CMRglc in cats using a high-resolution PET scanner. The present study provides the first direct evidence of CBF-CMRglc uncoupling occurring concurrently with persistent hypoperfusion following SD.