Hydroxyapatite-coating of pedicle screws improves resistance against pull-out force in the osteoporotic canine lumbar spine model: a pilot study.

BACKGROUND CONTEXT: In patients with spinal osteoporosis, the early achievement and maintenance of a biological bond between the pedicle screw and bone is important to avoid screw loosening complications. There are few reports of in vivo investigations involving biomechanical and histological evaluations in the osteoporotic spine. PURPOSE: To evaluate the effect of hydroxyapatite (HA)-coating on the pedicle screw in the osteoporotic lumbar spine and to investigate the relationship between resistance against the screw pull-out force and bone mineral density (BMD) of the vertebral body. STUDY DESIGN/SETTING: Mechanical and pathological investigations in the lumbar spine. METHODS: Two 24-month-old female beagle dogs were fed a calcium-free dog chow for 6 months after ovariectomy (OVX). BMD (in g/cm2) was measured by dual energy X-ray absorptiometry at pre-OVX and 6 months after OVX. Pedicle screws were placed from L1 to L6 at 6 months after OVX. Twenty-four pure titanium cortical screws (Synthes, #401-114) were used as pedicle screws (Ti-PS). Of these, 12 screws had HA-coating (HA-PS). The HA-PS screws were inserted into the right pedicles and the Ti-PS were inserted into the left pedicles. Ten days after this procedure, the lumbar spines were removed en bloc for screw pull-out testing and histological evaluation. RESULTS: The mean BMD value of the lumbar vertebrae 6 months after the OVX was 0.549+/-0.087 g/cm2, which was significantly less than the pre-OVX mean BMD of 0.603+/-0.092 g/cm2 (p < 0.001). The mean resistance against the pull-out force for the HA-PS was significantly greater at 165.6+/-26.5N than in the Ti-PS (103.1+/-30.2N, p < .001). The histological sections in the HA-PS clearly revealed new bone bonding with the apatite coating but only fibrous tissue bonding in the Ti-PS. CONCLUSIONS: The results of this study showed that the resistance to the pull-out force of HA-PS is 1.6 times that of Ti-PS. Furthermore, HA-PS has superior biological bonding to the surrounding bone, as early as 10 days after surgery in this osteoporotic spine model. Thus, in patients with osteoporosis, coating of the pedicle screw with HA may provide better stability and bonding between the pedicle screw and bone in the early postoperative period.     

Extracorporeal shock wave lithotripsy--difficulties in ESWL

At Kanbara Hospital, 187 patients with urolithiasis have been treated by extracorporeal shock-wave lithotripsy (ESWL) since the first ESWL treatment in December, 1986. Some cases in which ESWL could not be performed easily were experienced. These difficulties were analyzed retrospectively and some problems in the ESWL treatment are discussed.     

A case of mixed connective tissue disease successfully treated for hemophagocytic syndrome with intermittent intravenous injection of cyclophosphamide]

A 52 year-old woman noticed general fatigue, polyarthralgia, and muscle weakness of lower extremities in October 2001. In December, she felt difficulty in walking due to muscle weakness. In January 2002, she admitted another hospital because of dyspnea on exertion and edema of lower extremities. Laboratory test revealed leukocytopenia, the elevation of creatine kinase and positive anti-U1-RNP antibodies. Her chest computed tomography (CT) showed severe interstitial pneumonia. Cardiac echogram revealed that she had pericardial effusion and pulmonary hypertension. Then she was transferred to Keio University Hospital and she was diagnosed as having mixed connective tissue disease (MCTD) manifestating myositis, interstitial pneumonia, pulmonary hypertension and pericarditis. Prednisolone (PSL) 60mg daily following to methylprednisolone (mPSL) pulse therapy was begun and her symptoms were gradually improved. In middle of February, she complained of high fever over 39.0 degrees C. Bacterial culture tests were negative and laboratory data indicated pancytopenia and a high level of serum ferritin. Bone marrow aspiration revealed hemophagocytosis in bone marrow specimens and she was diagnosed as having hemophagocytic syndrome associated with MCTD. mPSL pulse therapy was not effective and intermittent cyclophosphamide pulse therapy (IV-CY) was performed resulting in improvement of the symptoms. This case suggested the effectiveness of IV-CY therapy in patients with corticosteroid-resistant HPS associated with connective tissue diseases.     

Seborrhoeic Dermatitis: Treatment with Anti-Mycotic Agents

In order to elucidate the effectiveness of anti-mycotics in treating seborrhoeic dermatitis, an attempt was made to isolate Malassezia from seborrhoeic lesions of patients of seborrhoeic dermatitis. The results revealed that, in male patients, 46/49 cases were positive for Malassezia furfur on the face and 30/48 cases were positive for M. furfur on the scalp. In female patients, 7/13 cases were positive for M. furfur on the face, and 6/17 cases were positive for M. furfur on the scalp. Anti-mycotic agents were excellent in 50% and good in 31% of the spore-positive cases, yielding an overall efficacy rate of 81%. In contrast, the treatment of the face with vehicle alone showed only one excellent result out of 8 cases. Although clinical improvement was rapid on the side treated with a topical corticosteroid in the half-side-test, numerous fungal elements remained. While the improvement with anti-mycotic agents was slower than that with the corticosteroid, clinical improvement became evident by the third week of administration and fungal elements disappeared.     

Clinical and manometric evaluation of anorectal function following low anterior resection with low anastomotic line using an EEA™ stapler for rectal cancer

Anorectal function was evaluated in eight patients who had low anterior resection of the rectum with a low anastomotic line, using an EEA^™ stapler, with determination of function based on periodic manometric studies and clinical symptoms. Immediately following surgery all patients suffered from frequent bowel actions and soiling. These symptoms improved with time and most patients could enjoy almost normal daily life by the sixth postoperative month. One month after surgery, anal canal resting pressure and maximum squeeze pressure were significantly reduced and rectoanal inhibitory reflex was absent; neither showed a distinct tendency to improve thereafter. Rectal sensation and reservoir capacity, which also were seriously impaired, recovered satisfactorily by the time of the six-month examination. This suggests that an improvement of clinical symptoms following this operation is dependent upon the recovery of reservoir capacity and sensation of the neorectum, and that this operative procedure is a functionally acceptable option for low rectal cancer.     

Deconjugating activity for sulfoconjugated dopamine in homogenates of organs from dogs.

To clarify the possibility that sulfoconjugated dopamine (DA) may play a physiological role by being converted to active free DA, we examined the deconjugating activity in homogenates of organs from dogs. Each tissue homogenate was incubated with sulfoconjugated DA, and the deconjugating activity of the organs was compared. The kidney and liver exhibited the highest deconjugating activities. In contrast, the intestine and heart showed lower arylsulfatase activities, and almost no activity was found in the brain or skeletal muscle. Moreover, in the heart, the deconjugating activity for sulfoconjugated DA was higher in the atrium than the ventricle. These results indicate that sulfoconjugated DA is converted to active free DA in homogenates of organs from dogs and that the deconjugating activity varies between different parts of an organ. Sulfoconjugated DA must be looked upon as a possible precursor or reservoir for the production of active free DA.     

Serum estrone sulfate levels in patients with breast cancer

Estrone and estradiol-17 beta concentration in breast cancer tissue are reported to be an order of magnitude higher than those of circulating plasma in breast cancer patients. This high level of estrogen is provided by local production from estrone sulfate (E1-S) through the sulfatase pathway. Then serum E1-S level was determined using direct radioimmunoassay method in order to monitor the estrogen kinetics of post-operative breast cancer patients. Peri-operative sequential E1-S determination was carried out in 10 patients. Among them, extremely higher level, as compared with normal menstruating level of 625-2670pg/ml, was observed just after an administration of tamoxifen (three weeks after operation) in two of 5 pre-menopausal patients. In order to evaluate the effect of tamoxifen on serum level of E1-S in post-operative pre-menopausal patients, serum E1-S level in 42 post-operative outpatients was examined. Although there was no difference in the average level of E1-S in post-menopausal patients treated with or without tamoxifen, average E1-S level in pre-menopausal patients treated with tamoxifen as adjuvant therapy was significantly higher than that in patients without tamoxifen. These results suggests that the administration of tamoxifen to premenopausal patients should be reconsidered from a view point of the estrogen kinetics.     

Desmoid tumor of the abdominal wall preoperatively suspected as urachal tumor: a case report]

A case of desmoid tumor of the abdominal wall which was preoperatively suspected as urachal tumor is presented. The patient was a 56-year-old man, who was referred to our clinic for further examination of the mass detected incidentally in the ventral region of the urinary bladder by computed tomography. Ultrasonography showed that the mass had a heterogenous and hypoechogenic content. An urachal tumor was suspected and surgery was performed to remove the tumor. During the operation we found that the tumor was completely separated from the urinary bladder and that it had originated from the left rectus abdominal muscle. The pathological diagnosis was desmoid tumor of the abdominal wall. Since urachal tumor has no characteristic findings on the imaging examinations, it is difficult to differentiate desmoid tumor of the lower abdominal wall from urachal tumor, preoperatively.