Assessing age-related change in Japanese mental foramen opening direction using multidetector computed tomography.

OBJECTIVE: The purpose of this study was to investigate how the opening direction of the mental foramen (MF) changes with age in a Japanese population using multi-detector computed tomography (MDCT). METHODS: Post-mortem MDCT scans of 121 Japanese subjects (66 males and 55 females) were carried out where all subjects possessed at least twenty teeth, including molar teeth, in the upper and lower jaws. Two angles of the mental foramen opening were measured, namely the superior-inferior angle in the coronal plane and anterior-posterior angle in the transverse plane, on the CT reconstructed images. The associations between age and these two angles were evaluated using a multiple regression analysis. RESULTS: For male subjects, the relationship between the superior-inferior angle and age was a quadratic curve (p < 0.001). This angle increased until the subject reached their early 50s and then the angle decreased with age. In the transverse plane, there was a linear relation between the anterior-posterior angle and age (p=0.002).It was noted also that the angle decreased with age. By contrast, however, no significant associations between the two angles and age for either measurement were noted for female subjects. This study demonstrated that the opening direction of the mental foramen changes with age in Japanese male subjects. By contrast this change in the opening direction of the mental foramen was not demonstrated in Japanese female subjects. In male subjects, the opening direction moves superiorly until the individual reaches their early 50s, and then moves inferiorly with advancing age. It also shifts from a posterior to an anterior position with age. CONCLUSION: These observed change differ from the results of previous studies. The findings could be useful for forensic science as they demonstrate a change in the position of mental foramen in a sample of contemporaneous male Japanese subjects.

Evaluation of a personal identification method using the fusion function of CT images and dental radiographs.

OBJECTIVES: We applied the fusion function of dental analysis software to examine whether the anatomical relationships of tooth roots when compared between reconstructed post-mortem CT (PMCT) and dental radiographs can aid dental identification. METHODS: One PMCT image taken from a cadaver (43-year-old male; Cadaver 1) was compared with 64 digital dental radiographs of the left and right upper and lower molars from Cadaver 1 and 30 other cadavers. Five corresponding anatomical reference points were marked on each image. After adjusting the angle and magnification using the fusion function, the automatically calculated error in pixels was determined five times for each of four sites on the images. RESULTS: Comparison of the PMCT image with the dental radiographs from the other cadavers revealed obvious discrepancies in the anatomical positioning of the teeth. When t-tests were applied to the data from any of the four sites, the error in pixels was found to be significantly smaller (p < 0.001) between Cadaver 1 and the other cadaver images. The average error in pixels between the PMCT and dental radiographs was smaller in the lower jaw than in the upper jaw. CONCLUSIONS: This method uses corresponding reference points on two images to calculate the error between the regions that contain all points. This feature also makes it possible to compare images taken with different modalities. The demand for a dental identification method involving PMCT is likely to increase, and we expect that the accuracy of dental identification will improve by using radiological images.

Brain structural changes as vulnerability factors and acquired signs of post-earthquake stress.

Many survivors of severe disasters, even those without posttraumatic stress disorder (PTSD), need psychological support. To understand the pathogenesis of PTSD symptoms and prevent the development of PTSD, the critical issue is to distinguish neurological abnormalities as vulnerability factors from acquired signs of PTSD symptoms in the early stage of adaptation to the trauma in the normal population. The neurological underpinnings of PTSD have been well characterized, but the causal relationships with the traumatic event are still unclear. We examined 42 non-PTSD subjects to find brain morphometric changes related to the severity of PTSD symptoms in a longitudinal magnetic resonance imaging study extending through the Great East Japan Earthquake. We found that regional grey matter volume (rGMV) in the right ventral anterior cingulate cortex (ACC) before the earthquake, and decreased rGMV in the left orbitofrontal cortex (OFC) through the earthquake were negatively associated with PTSD symptoms. Our results indicate that subjects with smaller GMV in the ACC before the earthquake, and subjects with decreased GMV in the OFC through the earthquake were likely to have PTSD symptoms. As the ACC is involved in processing of fear and anxiety, our results indicate that these processing are related to vulnerability for PTSD symptoms. In addition, decreased OFC volume was induced by failing to extinct conditioned fear soon after the traumatic event. These findings provide a better understanding of posttraumatic responses in early stage of adaptation to the trauma and may contribute to the development of effective methods to prevent PTSD.

Three-dimensional visualization of composite fillings for dental identification using CT images.

OBJECTIVES: This study aimed to discriminate between enamel and composite resins by differences in Hounsfield units shown on 16 section multidetector CT (MDCT) images taken of unidentified bodies. METHODS: First, we determined the Hounsfield units of composite resins in 15 extracted human teeth. We then filled a single cavity prepared in each of the teeth with one of five different types of composite resins, and scanned the teeth using our routine post-mortem CT protocol for the head and neck. Obtained data were transferred to a radiological workstation and reconstructed. Furthermore, post-mortem CT images of the head of three unidentified bodies were reconstructed in the same manner. RESULTS: Four types of composite resins containing radio-opaque fillers showed a constant value of 4000 HU, and one radiolucent composite resin showed values in the range of 660-800 HU in the extracted teeth. Pixels at 4000 HU indicated that the composite resins were selected and visualized as three-dimensional colour images. Composite resins could be visualized on reconstructed images of the three unidentified bodies, and the sites visualized matched those noted on the forensic dental charts. CONCLUSIONS: Discriminating enamel and composite resins containing radio-opaque materials was difficult because of their similar Hounsfield unit values. However, we did succeed in visualizing the composite resins despite limitations of the CT scale. CT reconstructed images can contribute to dental identification, particularly in cases where it is difficult to detect composite resins on external investigation, and these images can be prepared during routine dental identification work.

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.

Intra-abdominal hemorrhage due to rupture of a splenic vein aneurysm: a case report.

Splenic vein aneurysm (SVA) is extremely rare. Most patients with an SVA have portal hypertension. In this report we describe the first recorded case of intra-abdominal hemorrhage due to rupture of an SVA in a patient without evidence of portal hypertension. A 72-year-old man was admitted to our medical center in a state of shock, with complaints of acute abdominal pain and abdominal distention. Preoperatively, abdominal ultrasonography demonstrated an echo-free space in the abdomen, suggesting the presence of a fluid collection. In addition, computed tomography revealed an enhanced lesion with contrast material in the pancreatic tail. An emergency operation showed bleeding from the SVA near the pancreatic tail. Consequently, a distal pancreatectomy with splenectomy was performed. Histologically the lesion was diagnosed as an SVA surrounded by pancreatic tissue with chronic inflammatory changes. The patient's postoperative course was uneventful.

Inefficacy of cooking methods on mercury reduction from shark.

Shark and other carnivorous fishes present high potential risk of excessive contamination by mercury. The distribution of mercury throughout the body of blue shark--Prionace glauca--was analysed, and the effects on mercury levels by frying and baking in a laboratory oven, and in a microwave oven, were measured. There was no significant statistical difference in mercury levels in the samples taken from regions near the head, or from central and tail parts, indicating homogeneous distribution of the metal in muscles throughout the body. Frying and baking did not affect original mercury levels present in blue shark. This study indicates that specific studies are needed to define the efficacy or inefficacy of the cooking methods on mercury reduction from fish, in order to clearly resolve divergent opinions in the literature.

[Endonasal transsphenoidal surgery under local anesthesia for elderly patient with pituitary tumor: case report].

We present a surgical case under local anesthesia of an 88-year-old woman suffering from visual disturbance caused by pituitary adenoma. Magnetic resonance (MR) imaging showed a large pituitary tumor with suprasellar extension compressing the chiasmatic nerve. Neither she nor her family would agree to surgical therapy. However, when we proposed surgery under local anesthesia, they accepted it. Partial removal of the tumor via the endonasal transsphenoidal approach was carried out, uneventfully. The nasal surface was infiltrated with 4%-Xylocaine prior to the ordinary xylocaine injection to the nasal mucosa. The patient did not complain of any pain associated with the surgical procedure, including saline injection to the subarachnoid space through spinal drainage. The postoperative course was fine except for the temporarily appearance of diabetes insipidus. Postoperative MR imaging showed complete relief of compression to the chiasmatic nerve. Her visual field was improved dramatically. Endonasal transsphenoidal surgery under local anesthesia is thought to be one of the most useful methods of choice, especially in cases of elderly patient with pituitary tumor.

Spontaneous luxation of encapsulated intraocular lens onto the retina after a triple procedure of vitrectomy, phacoemulsification, and intraocular lens implantation.

PURPOSE: To report the clinical and histological findings of a luxated intraocular lens (IOL) in the capsular bag. METHODS: Review of a case. RESULTS: Twenty-three months after a triple procedure of vitrectomy, phacoemulsification, and IOL implantation for diabetic vitreous hemorrhage and cataract, the encapsulated IOL spontaneously luxated. Scanning electron microscopy showed sparsely distributed anterior and equatorial zonules, with only a few posterior zonules on the surface of the removed capusular bag. CONCLUSION: The absence of the anterior hyaloid membrane and posterior zonules and contraction of the lens capsule may cause dialysis of the zonules. Therefore, the anterior hyaloid membrane should be left in place in patients at low risk for the development of postoperative proliferation to maintain the long-term stability of the IOL.

Aging effects upon smooth pursuit induced by step-ramp stimulation.

OBJECTIVE: in predictable target movements, pursuit gains are extremely close to 1.0. Under these conditions, aging effects upon pursuit have not been detected. Step-ramp stimuli produced by unpredictable combinations would be favorable procedures to assess the properties of smooth pursuit between young and aged people. METHODS: the target was a 0.5 degrees red laser spot. Eye movements of 49 normal subjects (26 younger subjects less than 49 years old and 23 older subjects more than 50 years old) were recorded with infrared reflection oculography and sampled at 250 Hz. Step direction and distance (2, 4, 6, 8 degrees) followed by 10 degrees /s ramp speed movement in the same (onward stimulus) or opposite to the direction (backward stimulus) were programmed in an unpredictable way before each set of ten tests. Both onward and backward stimulation were randomly given for each subject. RESULTS: in the onward study, there was a close correlation between retinal slip velocity (RSV) and eye acceleration (EA), which was expressed as a regression curve, being steeper in the younger group. This means that the younger subjects could produce faster velocity and greater acceleration than the aged group (P<0.05). CONCLUSION: subtle reduction in visual acuity, visual fields and contrast sensitivity will be one of possible causes, and the degradation of cortical areas crucial for visual processing might be one of possible causes of slowing of pursuit EA.

Comparison of motor reactivity of the human colon cold-stored in different preservative solutions to carbachol and noradrenaline in vitro.

We have compared the reactivity to carbachol and noradrenaline of circular smooth muscle isolated from the human colon which was cold-stored at 4 degrees C in three different preservative solutions: Krebs bicarbonate solution (KBS), phosphate buffer solution (PBS) or minimum essential medium (MEM). Concentration-dependent contractions in response to carbachol were reduced in terms of both their sensitivity (pEC50) and reactivity (Emax), depending on the period of cold storage. The reduction was more marked when the tissue was cold-stored in either MEM or KBS than in PBS. Similar reduction of the relaxation response to noradrenaline was also observed after cold storage. It is concluded that the cold storage of surgically resected human colon in PBS for two to three days best preserved smooth muscle functions for pharmacological examinations.

Influence of vibration to the neck, trunk and lower extremity muscles on equilibrium in normal subjects and patients with unilateral labyrinthine dysfunction.

To investigate the role of proprioceptors of different skeletal muscles in postural control, in normal subjects and patients with unilateral labyrinthine dysfunction (ULD), the effect of vibration on these muscles was studied by postulography. The subjects comprised 59 normal subjects and 12 patients with ULD due to resection of acoustic tumours. Sagittal body sway was observed during vibration to the triceps surae, tibialis anterior and upper dorsal neck muscles. No significant change in sway was observed in the frontal plane in normal subjects. Significant differences between normal subjects and patients were found on stimulation of the muscle groups of triceps surae and biceps femoris during vibration. In patients with ULD, vibration to the dorsal neck muscles caused a deviation towards the diseased side. It can be speculated that the upper dorsal neck muscle plays an important role in maintaining the body balance in the frontal plane in patients with ULD. On the other hand, the lower extremity muscles, especially the muscles on the dorsal side of the body, play a significant role in adjusting the standing posture in the sagittal plane.

[Influence of proprioceptive input from leg, thigh, trunk and neck muscles on the equilibrium of standing].

To investigate and compare the roles of proprioceptive input from the leg, thigh, trunk and neck muscles on equilibrium, we performed static posturography in 50 normal subjects in the standing position on a force platform by applying vibratory stimulations to the muscles. The length of the displacement of the center of gravity, maximum sway length and sway area were measured. The amplitude of the body sway was maximum when the stimulation was applied to the dorsal neck. The forward shift of the center of gravity was also marked by stimulation applied to the dorsal neck. The amplitude of the body sway on stimulation of the leg muscles was also marked, although less than that of dorsal neck stimulation. The backward shift during stimulation of the gastrocnemius and the forward shift during stimulation of the anterior tibialis were remarkable. The results indicate that the leg muscles, which directly regulate the movement of the ankle joint, and the dorsal neck muscles, which change the static equilibrium through the central nervous system, are important for maintaining the standing posture.

Objective tinnitus caused by an aberrant internal carotid artery.

We report the case of a 29 year-old woman who complained of pulsatile tinnitus and impaired hearing. On otoscopic examination, her right tympanic membrane was observed to be in contact with a mass in the middle ear cavity, with the formation of a meniscus at the point of contact. Using a high-sensitivity microphone inserted into the external auditory canal, we recorded pulsatile tinnitus that was synchronous with the electrocardiogram. Magnetic resonance angiography revealed that the middle ear mass was an aberrant internal carotid artery coursing through the hypotympanum.

A long term follow-up of a randomized trial comparing interferon-alpha with busulfan for chronic myelogenous leukemia. The Kouseisho Leukemia Study Group.

To evaluate the long-term effectiveness of interferon-alpha (IFN-alpha) therapy in patients with chronic myelogenous leukemia (CML) in chronic phase, we examined the updated outcomes of 159 patients who had been enrolled between 1988 and 1991 into a randomized trial comparing IFN-alpha with busulfan. At a median follow-up of 73 months, the median survival was 71 months in the IFN-alpha group and 55 months in the busulfan group (P=0.0563), and the median time of remaining in chronic phase was 58 months in the IFN-alpha group and 39 months in the busulfan group (P=0.4676). Landmark analysis showed a significant advantage in survival (P=0.009) and duration of chronic phase (P=0.0001) in patients with any cytogenetic response among the IFN-alpha group. About half patients were discontinued IFN-alpha administration in spite of cytogenetic response in this study. It appears that continuation of IFN-alpha might possibly confer a survival advantage. Pretreatment factors associated with cytogenetic response included high hemoglobin level, low percentage of peripheral basophils and low leukocyte counts. Multivariate analysis identified lower percentage of bone marrow basophilia (P=0.007) for survival advantage. If a group with a very good prognosis is predicted by a new prognostic model, it might be an option to wait for bone marrow transplantation.

[A clinical phase III trial of ulinastatin (MR-20) for nephrotoxicity of cisplatin].

UNLABELLED: MR-20 was administered to 140 lung cancer patients who presented with nephrotoxicity due to cisplatin (CDDP) treatment at 59 institutions throughout Japan during the period from September 1992 through March 1994 to study its suppressive effect on the nephrotoxicity as well as its safety. The results are reported in this paper. METHODS: The efficacy and usefulness of MR-20 were studied in a placebo-controlled, double-blind manner. An efficacy rate of 58.7% was achieved in the MR-20 group, and 36.8% in the placebo group: MR-20 was significantly more effective for nephrotoxicity than placebo (U-test). Serum Cr, Ccr and FENa were prevented from significant variations in the MR-20 group, compared with the control group. It was considered that MR-20 is a safe drug, and that it is useful in suppressing the nephrotoxicity of CDDP treatment.