Junya Shimizu

TLR4 stimulation and corticosteroid interactively induce osteonecrosis of the femoral head in rat

We previously reported that a toll‐like receptor 4 signaling contributes to the development of osteonecrosis of the femoral head. Also, oxidative stress is suggested to be one of the possible pathogenesis of osteonecrosis of the femoral head. A recent study showed that toll‐like receptor 4 signaling leads to oxidative stress. The aim of the present study was to evaluate whether toll‐like receptor 4 stimulation and subsequent corticosteroid treatment lead to the development of osteonecrosis of the femoral head in rat, and oxidative stress is associated with it. Male Wistar rats were randomly divided into four treatment groups: Saline + Saline, Saline + Methylprednisolone, Lipopolysaccharide + Saline, Lipopolysaccharide + Methylprednisolone. Osteonecrosis of the femoral head at 14 days after the treatment was observed in 1 of 10 Lipopolysaccharide + Saline, and 5 of 10 Lipopolysaccharide + Methylprednisolone treated rats. However, it was not observed at all in the Saline + Saline and Saline + Methylprednisolone treated groups. Glutathione peroxidase activity in the liver at 1 day after the treatment was significantly increased when treated with lipopolysaccharide. However, methylprednisolone treatment reduced the activity. On the other hand, glutathione peroxidase activity in the femur did not change in any intergroup. In conclusion, the present study showed that toll‐like receptor 4 stimulation by lipopolysaccharide administration strengthen incidence of corticosteroid‐induced osteonecrosis of the femoral head, however, concomitant oxidative stress via toll‐like receptor 4 signaling may not contribute to the development of osteonecrosis of the femoral head in rats.

Freezing effect on brain density in postmortem CT

Two 60-year-old males were found at their homes whose bodies had deteriorated due to putrefaction. To prevent worm invasion and minimize deterioration, dry ice was used prior to the autopsy investigation. Prior to autopsy, postmortem CT demonstrated a decreased density in brain parenchyma at the dry-iced side, and autopsy revealed deteriorated brain parenchyma with frozen effect (presented like sherbet). Moreover, the deteriorated cerebral parenchyma maintained their structure and they were evaluated by cutting. When lower CT density presents in postmortem CT, the freezing effect may need to be considered and the physician should evaluate the cadavers postmortem condition to prevent misdiagnoses.

Susceptibility of Males, but Not Females to Developing Femoral Head Osteonecrosis in Response to Alcohol Consumption.

Background We previously reported that ethanol-containing liquid diet feeding induces osteonecrosis of the femoral head in male rats. Also, it was reported that a large amount of consumed ethanol and a long-term history of drinking were risk factors for osteonecrosis of the femoral head, and that the frequency of alcohol-induced osteonecrosis of the femoral head in males was much greater than in females. The higher incidence of alcohol-induced osteonecrosis of the femoral head could be due to either higher prevalence of alcohol drinking in males or due to their potential higher sensitivity to alcohol. The aim of the study is to investigate the influence of alcohol consumption and drinking period on the development of osteonecrosis of the femoral head in rats of both sex. Methods All the experimental male rats were allocated to the male one-month ethanol drinking group (M1). Female rats were randomly divided into the female one- to five-months ethanol drinking groups (F1-5). All rats were fed a Lieber-DeCarli liquid diet containing 5% ethanol for one to five months. Results One-month feeding with the ethanol-containing liquid diet resulted in the development of osteonecrosis of the femoral head in seven of twenty in the M1 group, but none in the F1 group, although the mean intake of ethanol per body weight in the M1 group was significantly lower than that in the F1 group. Furthermore, long drinking periods with a large amount of ethanol intake in the F2-5 groups did not induce osteonecrosis of the femoral head. Conclusion The present study shows that lower alcohol consumption over short periods of time that were sufficient to induce osteonecrosis of the femoral head in males had no effect on females. Even with greater alcohol consumption and longer duration, females did not develop osteonecrosis of the femoral head. Therefore, unknown factors related to sex must be responsible for the development of this condition.

Experimental drowning lung images on postmortem CT - Difference between sea water and fresh water

PURPOSE Experimental drowning models were prepared to investigate the time-related course of lung changes using postmortem CT. This study was approved by our institutional animal ethics committee. MATERIALS AND METHODS Fifteen NZW rabbits (female fifteen, 2.6-4.3 (mean 3.3)kg) were divided into 3 groups: fresh water drowning (FRESH), sea water drowning (SEA), and sea water drowning with anterior chest compression (ACC). All individuals were examined by CT (Aquilion CX, Toshiba, Japan) on postmortem time course. The rabbits head was submerged in a water bath for a total of 10 min. In ACC, cardiopulmonary resuscitation was performed for 2 min, additionally. The percentage of aerated lung volumes (%ALV=100 (aerated lung volume/total lung volume)) were statistically evaluated and the lung CT image patterns and pleural fluid appearance time were investigated. RESULTS All lungs had decreased their %ALV within 24h, and there were no statistical differences in and among the 3 groups. After 36 h, %ALV tended to increase in all groups, and only ACC presented a statistical difference between 1h and 36 h (p<0.005). On postmortem lung CT, all lungs presented ground-glass opacity with interstitial thickening spread pattern (100%) and no pattern change during the follow-up period. After presenting pleural space fluid collection, the %ALV tended to increase. CONCLUSION There were no differences among FRESH, SEA, and ACC in %ALV within 24h. Only ground-glass opacity could be detected on postmortem lung CT, experimentally.

Atypical fungal vertebral osteomyelitis in a tsunami survivor of the Great East Japan Earthquake.

Study Design. Case report. Objective. We report a rare case of fungal vertebral osteomyelitis in a tsunami survivor of the Great East Japan Earthquake. Summary of Background Data. Fungal vertebral osteomyelitis due to Scedosporium apiospermum (S. apiospermum) is extremely rare. We describe the case of a 45-year-old male who developed vertebral osteomyelitis by S. apiospermum 1 month after near drowning in the huge tsunami after the Great East Japan Earthquake. Methods. The patient was treated with a combination of percutaneous posterolateral endoscopic debridement and antifungal therapy. The case was evaluated with radiography and computed tomography, and his white blood cell count and C-reactive protein level in serum were measured 20 months after initiation of treatment. Results. The patient had no low back pain and both white blood cell count and C-reactive protein had remained normal. Radiographs and computed tomography of lumbar spine demonstrated sclerotic change of endplates and spur formation bridging the L3 and L4 vertebral bodies. Conclusion. We report a rare case of the fungal vertebral osteomyelitis caused by S. apiospermum. If a patient develops severe back pain after a near-drowning episode in dirty water such as a swamp or a river, the clinician should be suspicious of the possibility of fungal spondylitis by S. apiospermum. Level of Evidence: N/A

Chondrosarcoma mimicking MRI of the osteonecrosis of the femoral head: a case report

A 25-year-old female visited our hospital with an 8-year history of arthralgia in the right hip joint. Plain radiography of the hip revealed a well-demarcated radiolucent lesion with a thin sclerotic rim in the epiphysis of the femoral head. T 1 weighted MRI revealed the demarcation line of a low-signal-intensity band in the femoral head. We were aware that this band did not split the signal of adipose tissue in the bone marrow. In cases of osteonecrosis, we usually find a low-signal-intensity band splitting the signal of normal bone marrow. However, we could not see such a low-signal-intensity band in this case. Therefore, we decided to perform other studies. Contrast-enhanced T 1 weighted MRI showed remarkable enhancement in the segment proximal to the low-signal-intensity band, indicating that this lesion might have blood perfusion. We decided to perform a bone biopsy to clarify the diagnosis. Histopathological examination of the biopsy specimen revealed chondrosarcoma. We found that contrast-enhanced MRI plays an important role to rule out osteonecrosis of the femoral head.

Nodular fasciitis involving the palm

Nodular fasciitis (NF) is a self-limiting fibrous neoplasm that can be mistaken for a soft tissue sarcoma. It is characterised by rapid growth, slight pain and local tenderness. Although it is frequently found in the forearm, a lesion distal to the wrist is quite rare. We present two unusual cases of NF involving the palm, supported by detecting ubiquitin specific protease 6 gene rearrangement. The first patient had non-intraneural NF presenting as peripheral neuropathy affecting the digital nerve while the second patient suffered from painless, non-tender NF in the palm, which had not regressed spontaneously during the five months prior to surgery.

Hemangioma of the rib showing a relatively high 18F-FDG uptake: a case report with a literature review

Hemangioma of the rib is a rare benign tumor that is often difficult to distinguish from malignant bone tumors. Rib hemangioma often shows bony disruption with a slight cortical disruption, extraosseous lesion, and expanded bone on computed tomography (CT). We report the case of a 68-year-old man with atypical rib hemangioma with a slight cortical disruption and no expanded bone. The tumor showed relatively high 18FDG-uptake on positron emission tomography (PET)/CT. Rib hemangioma often shows higher 18FDG-uptake. PET/CT may not provide useful information for distinguishing rib hemangioma from a malignant tumor. Close observation without surgical resection may be feasible if the tumor is diagnosed as a rib hemangioma by biopsy.