Diminished kidney function and nephrocalcinosis in rats fed a magnesium-deficient diet

The effect of a magnesium-deficient diet on kidney function was studied in young male rats. The rats were fed a purified diet with a magnesium content of either 20.5 (control diet) or 2.6 mmol/kg (magnesium-deficient diet) for 21 d. In rats fed the magnesium-deficient diet, kidney wet and dry weights were significantly increased, and calcium and phosphorus concentrations in the kidney were significantly higher than in rats fed the control diet. Upon histological examination, an increase in the mesangial matrix of the glomeruli and injury to the brush border of the proximal tubules were observed in rats fed the magnesium-deficient diet. Also, a deposition of calcium was observed in the tubules of the corticomedullary junction and medulla of these rats. Total protein and albumin concentrations in serum were significantly decreased in rats fed the magnesium-deficient diet. Urinary albumin excretion was significantly higher, and N-acetyl-beta-D-glucosaminidase activity in the urine was significantly increased in rats fed the magnesium-deficient diet. These findings indicate diminished glomerular and proximal tubular functions. We suggest that a magnesium-deficient diet not only induces nephrocalcinosis, but it also diminishes kidney function.

Assessment of P-glycoprotein in patients with malignant bone and soft-tissue tumors using technetium-99m-MIBI scintigraphy

Overexpression of P-glycoprotein (Pgp) has been detected in many malignant tumors including bone and soft-tissue tumors. Technetium-99m-MIBI has proved to be a transport substrate for Pgp. The purpose of our study was to explore 99mTc-MIBI as a functional imaging agent reflecting Pgp expression in malignant bone and soft-tissue tumors.

METHODS

Technetium-99m-MIBI scintigraphy was performed in 30 patients with malignant bone and soft-tissue tumors. Radionuclide angiography with 99mTc-MIBI was done and, at 15 min and 3 hr postinjection of the radiopharmaceutical, imaging was performed. The 99mTc-MIBI uptake ratio was calculated by dividing the lesion count by the background count. The washout rate (WR) for 99mTc-MIBI was calculated by the following formula: WR = 100 x [(Te-Be)-(Td-Bd)]/(Te-Be) (%), where Te and Td = decay-corrected count density of the tumor in the 15-min and 3-hr images, respectively. Be and Bd = decay-corrected count density of the background in the 15-min and 3-hr images, respectively. The lesions were resected by open biopsy to obtain a histopathological diagnosis, and immunohistochemical staining was performed to detect Pgp.

RESULTS

Twenty-four of 30 patients showed significant uptake at the 15-min image. In these 24 patients, the lesions with a high Pgp expression showed a similar 99mTc-MIBI perfusion index (3.00 +/- 1.04) and uptake ratio (2.05 +/- 0.58) at the 15-min image to those of lesions without a high Pgp expression (2.65 +/- 0.85 and 2.28 +/- 0.64, respectively). On delayed images, the 99mTc-MIBI uptake ratio was lower in patients with a high Pgp expression than in patients without a high Pgp expression (1.37 +/- 0.41 versus 1.87 +/- 0.39, p < 0.01). The washout ratio of 99mTc-MIBI was higher in patients with a high Pgp expression than in patients without a high Pgp expression (66% +/- 25% versus 29% +/- 18%, p < 0.001). None of the 6 patients without 99mTc-MIBI uptake at the 15-min imaging showed 201TI uptake, and only 2 had a high Pgp expression.

CONCLUSION

In malignant bone and soft-tissue tumors, perfusion and initial 99mTc-MIBI uptake were not related to the Pgp expression; however, washout of 99mTc-MIBI from the tumor was related to Pgp expression. Technetium-99m-MIBI scintigraphy with washout analysis may be a useful method for the evaluation of Pgp overexpression and its function.

[An elderly patient with an insulinoma who had prolonged dementia-like symptoms]

A 77-year-old woman had suffered from memory disturbance and disorientation for two years before she was admitted to the hospital because of confusion. Her score on the Hasegawa dementia scale revised (HDS-R) was 12 points at the time of the first medical examination. No other abnormalities could be found except for a blood glucose concentration of 34 mg/ dl. A Magnetic Resonance Image (MRI) of the brain showed some small lacunae on both sides in the frontal white matter and basal ganglia. After hospitalization, glucose was administered and the blood glucose concentration increased, but the dementia-like symptoms did not resolve. She was discharged because the symptoms were too difficult to control in the general hospital. Although dementia-like symptoms were present even after discharge, they did not necessarily appear during fasting. Six months later she was rehospitalized. The insulin-blood sugar ratio was at least 0.3 and abdominal echogram showed a 1-cm tumor at the tail of pancreas. The pancreas tail was removed and the tumor cells were reacted with anti-insulin-antibodies. One month after the operation, the dementia-like symptoms had resolved. The HDS-R score was improved to 27 points (normal range) 40 days after the operation. The amount of the slow waves in the electroencephalogram decreased 5 months after the operation. The dementia-like symptoms observed in this case could be regarded as the Durchgangssyndrom of Wieck. This syndrome is observed transiently at the time of recovery of deterioration of disturbances of consciousness. But it is treatable. This patient was an interesting case that showed Durchgangssyndrom mimiking dementia associated with insulinoma.

Identification of cDNAs induced by the tumor suppressor Tsc2 gene using a conditional expression system in Tsc2 mutant (Eker) rat renal carcinoma cells

Alteration of the rat homologue of the tuberous sclerosis 2 (TSC2) gene is associated with dominantly inherited cancer in the Eker rat model, indicating a tumor suppressor nature. The ability of Tsc2 to activate signal transduction and transcription suggests that genes induced by Tsc2 may mediate its biological roles. Using a subtractive hybridization approach in combination with tetracycline operator systems, we identified a set of downstream genes affected by Tsc2. Regulated expression of wild-type Tsc2 gene in Eker renal carcinomas (RCs) resulted in marked expression of cell arrest or programmed cell-death-related genes and stress-induced genes. Thus, the data suggest that Tsc2 might contribute to regulation of the cell cycle and cell survival.

Differential fasciculation of follicular nerves for transferring specifically localized cues of the vibrissa rudiments to the central trigeminal sensory system in mice, as exploited with DiI and DiA labeling

Vibrissa connections play a decisive role in setting the somatotopic coordinates in the trigeminal sensory system. Although previous studies have examined the development of peripheral patterning, certain questions are still in dispute, for example, the way vibrissa connections are structured, and the relationship between periphery and central organization, and ganglion cell organization. In order to fill the blanks left by previous studies, the extension of ganglionic branches and the formation of vibrissa connections were reexamined by using fluorescent carbocyanin dyes, DiI and DiA, during embryonic days 10 to 14 in mouse. Whole-mount preparations satisfactorily demonstrated the ganglionic fiber system, which allowed detailed analysis at both macroscopic and microscopic levels. We show here that the differential fasciculation of follicular nerves is the critical process for organizing vibrissa connections which modulate the initially extending fiber pattern. Follicular nerves developed by fine fibers arising from initially ordered root fascicles, so as to connect with vibrissa rudiments that developed on the facial prominences. During differential fasciculation, ganglion cells were segregated into distinct groups by the vibrissa connections, whereas central fiber terminals did not yet develop specific structures in the nuclear region. In the primary order of the trigeminal sensory system, vibrissa connections in the periphery were organized before those of the central structure. These results indicate that trigeminal ganglion cells have a critical binomial function in order to transfer the somatotopic relations among vibrissa rudiments into the topographic coordinates of the central system.

Telemedicine using a desktop conference system (Phoenix) in Kyushu, Japan

OBJECTIVE

The Kyushu area of southwestern Japan has several mountains and 157 inhabited islands. We assessed the feasibility of implementing a desktop conference (DTC) system to improve medical care in this area. TELECOMMUNICATIONS TECHNOLOGY AND EQUIPMENT: The Phoenix DTC system (NTT Corporation, Tokyo, Japan) for personal computers includes a microphone, speaker, color CCD camera, and appropriate software. We used a digital camera for still pictures and image-analysis software for radiographs and CT and MRI films. The system was installed on a Pentium 133 MHz computer, which was connected by ISDN line at a 128 kbps data rate to a clinic on a small island where one physician cares for 1000 residents, two small nursing offices where each nurse tends 100 residents, two nursing homes, a hospital in a mountainous area, and the residence of a patient with atopic dermatitis. Connections were made once a week for a period of 6 months.

RESULTS

The transmitted still pictures; e.g., senile nevus, atopic dermatitis, chickenpox, and a radiograph of a suspected fracture, were useful for diagnosis and clinical decision making. We received and responded to inquiries from residents of the participating nursing homes on nutrition, senile depression, nevus, decubitus ulcers, urinary tract infection, and protection against Legionella infection. We also used the system to deliver lectures on pediatrics to nurses; provided case discussions on diaphragmatic herniation and subtentorial tumor; and had on-line presentation of a patient with beta-thalassemia using presentation software.

CONCLUSION

The DTC system used in the present study seemed technically satisfactory and useful in improving medical care in remote sites of Japan.

Establishment and characterization of an acquired cisplatin-resistant subline in a human osteosarcoma cell line

A cisplatin (CDDP)-resistant human osteosarcoma cell line (OST/R) was established by continuous exposure to CDDP. OST/R cells proved to be 6.73 times more resistant to CDDP compared with parental OST cells, and showed cross-resistance to carboplatin (CBDCA). The mechanism of CDDP resistance was a significant decrease of intracellular platinum accumulation which was 40% of that in OST cells. OST/R cells were exposed to CDDP for 6 hours, the platinum was released from the cytoplasm of OST/R cells without reaching a state of equilibrium. DNA synthesis in OST/R cells was not inhibited by CDDP exposure, while in OST cells it was reduced by 50%. These data provide the first evidence that the increased efflux of platinum may play an important role in CDDP-resistance.

Congenital aural sinuses: clinical study and application of microsurgery

METHODS

The authors studied 45 cases of congenital aural sinuses.

RESULTS

Aural sinuses were observed on both sides in 17 cases (37.8%) and in girls (24 cases, 53.3%). Family history was positive in 12 cases (26.6%), and history of local infection was present in 40 cases (88.9%). The opening of aural sinuses was located most frequently in the marginal helicine region (36 cases, 80%).

CONCLUSIONS

Microsurgery was extremely effective for accurate determination of the margins of intricately ramified aural sinuses, their detachment from surrounding tissues, and their total resection. Complete resolution without postoperative complications was achieved in 43 cases (95.6%).

Reversed-phase ion-pair chromatographic analysis of tetracycline antibiotics. Application to discolored teeth

A high-performance liquid chromatographic method with diode array detection was developed to simultaneously separate tetracycline antibiotics and applied to the analysis of discolored teeth. By a reversed-phase ion-pair chromatographic system using pentanesulfonate as a counter ion, minocycline, oxytetracycline, tetracycline and demeclocycline were eluted in this order, and they showed base-line separation within 9 min. When using oxytetracycline as an internal standard, the quantitative ranges were between 2.5 ng/ml and 7.5 microg/ml. Powdered dentine (10 mg) and enamel (40 mg) prepared from discolored primary teeth were sonicated in 0.25 ml of 10 mM HCl containing oxytetracycline (0.75 microg/ml) and 50 mM EDTA-2Na, thereafter the supernatants were chromatographed. Eluates from both discolored tooth samples were identified as minocycline based on diode array spectra of their peaks, while minocycline was not detected in any samples from nondiscolored normal teeth, indicating that discoloration of the tested teeth was due to minocycline incorporated into dentine and enamel. Replicate quantitative analyses of the identical tooth substances showed that intra- and inter-assay C.V.s were 2.63 and 4.95% for dentine, and 5.42 and 10.88% for enamel. Application of the developed method to nine discolored teeth revealed that the incorporated minocycline ranged from 20.13 to 84.62 ng/mg of dentine and 0.89 to 7.87 ng/mg of enamel.

Zinc and phytate intake of rural Gambian infants: contributions from breastmilk and weaning foods

Zinc and phytate intakes of 183 rural Gambian infants were obtained from weighed records of breastmilk and food intake and measured contents in foods. Total zinc intake of 2.7 mg/d in the first month of age declined to 1.5 mg/d at 3 months, then increased to 4.3 mg/d by 17 months. Breastmilk was an important source of zinc, but the predominant cereal and groundnut-based foods had high [phytate]/[Zn] molar ratios ranging from 13 to 28, indicating potential impaired zinc bioavailability. The [phytate]/[Zn] molar ratio for the diet as a whole was low in early infancy, but increased to 13 in the second year. In contrast, this ratio was less than 6 for the diet of 48 Cambridge breastfed infants up to 18 months. A further disadvantage to the Gambian infants was indicated by their lower intake of protein of animal origin. However, calcium intake was estimated in both communities to be below the level which could give rise to zinc chelation in association with phytate. Compared to 'basal' and 'normative' requirements, total zinc intake of the Gambian infants showed the greatest shortfall between 3 and 12 months, making this the age band for maximum probable benefit from focused intervention programmes.

Rapid diagnosis of oral tuberculosis by amplification of Mycobacterium DNA from paraffin embedded specimens

The polymerase chain reaction (PCR) assay is a powerful tool for quick diagnosis of various infectious diseases. We applied this technique as well as conventional histopathological examination to diagnose oral tuberculosis. Ziehl-Neelsen staining of oral mucosal specimens often fails to detect Mycobacterium (M.) tuberculosis due to the low number of bacteria in the tissue. Specific primers and probes were synthesized based upon the nucleotide sequence of the 65 kDa membrane protein of M. tuberculosis. DNA extracted from the paraffin-embedded tissue was amplified using taq polymerase. PCR assay detected M. tuberculosis in 5 of 6 samples. Although the gene segments from these species were quite similar, the gamma 32P labeled noligonucleotide probes distinguished between M. tuberculosis and M. fotuitum by southern blot hybridization. In all specimens that were Ziehl-Neelsen negative, M. tuberculosis DNA was detected by PCR. These results suggest that PCR is a useful means of diagnosing mycobacterium infection.

Blood flow measurement during distraction osteogenesis

The regional blood flow of 30 distraction segments in 27 patients was measured during distraction osteogenesis. There were three groups of patients. Group A consisted of seven patients with high grade malignant tumors who received chemotherapy preoperatively and postoperatively. Group B consisted of eight patients with low grade malignant and aggressive benign tumors, who all were treated without chemotherapy. Group C (the control group) consisted of 12 patients with nontumoral conditions. Using quantitative technetium scintigraphy, the regional blood flow within the distracted segment and surrounding soft tissues was measured. The measured radioisotope count was expressed as the ratio of the distracted site to the control site (blood flow ratio). The blood flow ratio for all the cases averaged 1.70 +/- 0.70. Group A had a lower blood flow ratio, which was statistically significant in comparison with the other two groups. The external fixation index showed no significant difference in callus formation among these three groups. No correlation was found between the blood flow ratio and external fixation index. Chemotherapy decreases regional blood flow, but with distraction osteogenesis the regional blood flow can be kept within the normal range or higher. Distraction osteogenesis may overcome the effects of chemotherapy by increasing blood flow.

Caffeine-assisted chemotherapy and minimized tumor excision for nonmetastatic osteosarcoma

Osteosarcoma is usually treated with intensive preoperative and postoperative chemotherapy and wide tumor resection, resulting in a 60% to 70% 5-year survival rate. Caffeine has a DNA-repair inhibiting effect. We therefore investigated the impact of caffeine given in conjunction with chemotherapy and limb-sparing surgery on survival and local tumor control in patients with nonmetastatic, high-grade osteosarcoma. Twenty-two patients were given 3 to 5 preoperative courses of intra-arterial cisplatin (120 mg/m2, 1 to 2 hours) and caffeine (1.5 g/m2/day x 3 days) with or without doxorubicin (30 mg/m2/day x 2 days). Following this treatment, limb-sparing surgery was performed by means of intentional marginal excision aiming at preservation of important structures such as major neurovascular bundles, tendons, ligaments and the epiphysis. Three courses of cisplatin and doxorubicin combined with caffeine, and high-dose methotrexate with vincristine and citrovorum factor rescue were given intravenously as postoperative chemotherapy for 21 patients and three courses of high-dose methotrexate and combination of ifosfamide, etoposide and methotrexate for 1 patient. Following the preoperative chemotherapy, there were no viable tumor cells in 19 patients, only scattered foci of viable cells in 2 patients, and some areas of viable tumor cells in 1. The 21 patients with a good chemotherapeutic response on radiographs underwent minimized marginal excision. Functional evaluation of the affected limbs was excellent for 17 patients, good for 3, fair for 1, and poor for 1. No local tumor recurrence was seen in this series. Eighteen patients remain disease-free with a mean follow-up of 61 months. Two patients died of metastatic disease, 1 died of chemotherapy-related complications, and 1 died of unknown causes. The overall 5-year cumulative survival rate was 90%, and the 5-year event-free survival rate was 75%. Chemotherapeutic caffeine enhanced tumor necrosis and improved the success rate of limb-sparing surgery using marginal procedure without any adverse impact on survival. The results of our limited clinical trial appear to justify further prospective, multicenter randomized trials of the benefits of caffeine combined with chemotherapy for nonmetastatic osteosarcoma and other malignant neoplasms.

Visuospatial attention shift and motor responses in cerebellar disorders

The cerebellum has been implicated in higher cognitive functions including learning, memory, and attention as well as its well-known role in motor programming. Recent studies have suggested that the cerebellum plays a role in shifts of attention. We investigated the contribution of the cerebellum to visuospatial attentional ability in a trial-by-trial cueing task involving the covert orienting of spatial attention. We recorded event-related evoked potentials (ERPs) and reaction times (RTs) in patients with cerebellar degenerative disorders affecting mainly the lateral cerebellum and compared them to age-matched controls. The RT data demonstrated that both the cerebellar patients and control subjects responded to the valid cues faster than to the invalid cues for both the central and the peripheral cues. Consistent with the RT data, the ERP data showed a comparable generation of attention shift-related negativities during the cue-target interval for both the central and the peripheral cue experiments. The early negative component of the ERP to the target was also comparably modulated in both groups as a function of cue validity, suggesting efficient facilitation of sensory pathways by prior allocation of spatial attention to the cued place. Conversely, the late negative deflection preceding the imperative target stimulus and the late sustained positivity following target presentation, which reflect neural activities for response preparation and selection, were reduced in the cerebellar group. These findings suggest that the lateral cerebellum makes little contribution to visuospatial attention shift in either the voluntary or automatic modes and support a role of the lateral cerebellum in the neural system required for response preparation and selection.

Overexpression of members of the AP-1 transcriptional factor family from an early stage of renal carcinogenesis and inhibition of cell growth by AP-1 gene antisense oligonucleotides in the Tsc2 gene mutant (Eker) rat model

We previously isolated subtracted cDNA clones for genes having increased expression in Tsc2 gene mutant (Eker) rat renal carcinomas (RCs). Among them, fra-1 encoding a transcriptional factor activator protein 1 (AP-1) was identified. We have therefore investigated whether other members of the AP-1 transcription factor family might also be involved in renal carcinogenesis in the Eker rat model. In the present study, overexpression of fra-1, fra-2, c-jun, junB, and junD mRNAs was demonstrated in RCs by Northern blot analysis. Interestingly, AP-1 proteins were highly expressed even in the earliest preneoplastic lesions (e.g., phenotypically altered tubules) as suggested by immunohistochemistry. Moreover, 12-O-tetradecanoylphorbol-13-acetate-responsive element (TRE)-binding activity of AP-1 proteins was observed in RC cell extracts by electrophoretic mobility shift assay. As a next step, we transfected antisense oligonucleotides targeting AP-1 genes into RC cells and demonstrated that their growth was strongly inhibited. Thus, the data suggest that overexpression of AP-1 genes might play a crucial role in renal carcinogenesis in the Eker rat model.

Simultaneous determination of catechins in human saliva by high-performance liquid chromatography

Green tea extracts have been suggested to possess a preventive effect against dental caries. A quantitative method for their anticariogenic substances, catechins, was developed to evaluate their concentrations in human saliva after mouthrinsing with green tea extract. Salivary catechins were extracted to the organic phase after forming a complex with diphenylborate and an ion-pair with tetra-n-butylammonium, and then back-extracted to the acidic aqueous phase. The extract was analyzed by high-performance liquid chromatography using diode array detection at absorption wavelengths ranging from 269 to 278 nm. In reversed-phase chromatography by a gradient elution, eight catechins originating from green tea and an internal standard were separated in 15 min without interfering peaks. All the catechins were simultaneously and selectively determined in the concentration range 0.05-25.0 microg/ml. In replicate spiking experiments with standards, the mean recovery ranged between 86 and 99%, and both intra- and inter-assay C.V.s were within 2.3%. When mouthrinsing with an aqueous solution of green tea extract (5.0 mg/ml) containing eight catechins, the quantitative results revealed that each catechin was retained at microg/ml levels in saliva for up to 60 min.

Thallium-201 SPECT in differentiating bone infarction from metastatic lesions in osteosarcoma

The authors present a case of bone infarction in the proximal epiphysis of the right tibia, which was caused by preoperative intraarterial chemotherapy for osteosarcoma. MR imaging revealed that suspected metastases had inhomogeneous signal intensity similar to that of the primary tumor, which made a metastatic lesion difficult to exclude. On TI-201 SPECT, no accumulation was found in the lesions, confirming that they were not osseous metastases. Consequently, this enabled limb salvage surgery to be performed with joint preservation. Intraoperative biopsy revealed no viable tumor cells in the lesion, and bone infarction was suspected. TI-201 SPECT was very useful, not only in differentiating bone infarction from tumor progression, including metastatic lesions, but also in the determination of the operative technique.

Growth inhibition of oral bacteria related to denture stomatitis by anti-candidal chalcones

In the antimicrobial therapy of denture stomatitis, it is desirable to inhibit the growth of not only the primary causative organism, Candida albicans, but also other oral bacteria closely associated with the condition. Three synthetic anti-candidal chalcones were characterized and compared for their additional activity in inhibiting these causative bacteria. Among the tested chalcones, 2,4,2'-trihydroxy-5'-methylchalcone showed the highest activity for different Gram-positive bacteria. It inhibited the growth of streptococci, staphylococci and lactobacilli at 25.0-50.0 micrograms/mL which was lower than or comparable to its minimum inhibitory concentration for candida. It functioned with a bactericidal action and leaked 260 nm-absorbing substances from the streptococcal cells. The antimicrobial activity of 2,4,2'-trihydroxy-5'-methylchalcone against both primary and secondary causative agents suggests it could be useful as a potent therapeutic agent in denture stomatitis.

Massive autoclaved allografts and autografts for limb salvage surgery. A 1-8 year follow-up of 23 patients

We performed 23 reconstructions with bone grafts autoclaved at 135 degrees C for 10 minutes for extensive bone defects after tumor resection. In 15 cases, the resected specimens were autoclaved and used as autografts. In 7 cases, allografts obtained from amputated extremities or cadavers were autoclaved and immediately stored at -80 degrees C prior to their use. A combination of the two was used in 1 case. The grafts were used in combination with prostheses or other forms of internal fixation. The mean follow-up was 49 (14-98) months. Incorporation of the hostgraft junction was observed radiographically after a mean of 11 (6-17) months in all cases. No recurrence due to the autoclaved bone was observed. However, 10 patients suffered complications, including infection, bone resorption, fracture and loosening of the prosthesis. In terms of Mankin's evaluation of bone grafts, 12 patients were evaluated as good or excellent. We conclude that despite the complications, autoclaved autografts and allografts are viable options for reconstruction in many countries because of the difficulty of obtaining large quantities of fresh frozen allografts.

Blockage of mesenteric lymphatic flow in rats

An experimental model of blockage of the mesenteric lymphatic flow (MLF) in rats was designed, and morphologic changes of mesenteric lymphatic vessels (MLV) and lymph nodes were investigated by mesenteric lymphangiography and histopathologic examination. Body weight in rats with blockage of MLF did not increase normally. Mesenteric lymphangiography revealed dilation of the MLV, reverse flow into the peripheral MLV, and leakage of contrast medium, resulting in chylous ascites. Remarkable dilation of the lymphatic sinuses and dilated and increased rough endoplasmic reticulum in lymphocytes in the mesenteric lymph nodes due to lymph stagnation were observed by light and electron microscopic examination, respectively.

[Leukoencephalopathy probably caused by tacrolimus hydrate after stem cell transplantation in a girl with MDS 7 monosomy]

Leukoencephalopathy probably caused by tacrolimus hydrate after stem cell transplantation in a girl with MDS 7 monosomy is reported. The conditioning regimen consisted of thiotepa (150 mg/m2 x 4), melphalan (70 mg/m2 x 2) and 12 Gy total body irradiation. She received peripheral blood CD34 positive cells (4.17 x 10(6)/kg) from her HLA-mismatched father and tacrolimus hydrate was used for GVHD prophylaxis. Engraftment was rapid and grade 1 acute GVHD of the skin responded well to pulse therapy. From day 27 she became irritable and sleepless, and right facial convulsions developed on day 37. No abnormality was found in the cerebrospinal fluid. Cranial CT findings showed no abnormalities except for low density lesions around the bilateral ventricle. Leukoencephalopathy was suspected and tacrolimus hydrate was discontinued. Thereafter psychosomatic symptoms improved, temporarily however, similar symptoms again developed following cyclosporine administration. Therefore we had to halt the administration of both tacrolimus and cyclosporine. She died on day 104 because of GVHD and fungal infection without recovering from leukoencephalopathy.

LIMB SALVAGE USING DISTRACTION OSTEOGENESIS

We report the results of distraction osteogenesis (callotasis) for the reconstruction of extensive defects after the excision of skeletal tumours in the limbs. Bone transport was performed in ten patients (five osteosarcomas and five giant-cell tumours), shortening-distraction in three (two osteosarcomas and one Ewing’s sarcoma), and distraction osteogenesis combined with an intramedullary nail to reduce the time of external fixation in six (three osteosarcomas, two chondro-sarcomas, and one malignant fibrous histiocytoma).

The mean length of the defects after excision of the lesion was 8.4 cm. The mean external fixation index was 39.5 days/cm for the group treated by bone transport, 34.1 days/cm for the shortening-distraction group, and 24.0 days/cm for the group treated by distraction and an intramedullary nail. Functional evaluation gave excellent results in 12 patients, good in five and fair in two. There were ten complications in 19 patients, all of which were successfully treated.

We also classified reconstruction using distraction osteogenesis into five types based on the location of the defects after resection of the tumour: type 1, diaphyseal; type 2, metaphyseal; type 3, epiphyseal; type 4, subarticular reconstruction; and type 5, arthrodesis.

Our results suggest that reconstruction using distraction osteogenesis provides bone which will develop sufficient biomechanical strength and durability. It is beneficial in patients with an expectation of long-term survival and in growing children.

Limb salvage using distraction osteogenesis. A classification of the technique

We report the results of distraction osteogenesis (callotasis) for the reconstruction of extensive defects after the excision of skeletal tumours in the limbs. Bone transport was performed in ten patients (five osteosarcomas and five giant-cell tumours), shortening-distraction in three (two osteosarcomas and one Ewing's sarcoma), and distraction osteogenesis combined with an intramedullary nail to reduce the time of external fixation in six (three osteosarcomas, two chondrosarcomas, and one malignant fibrous histiocytoma). The mean length of the defects after excision of the lesion was 8.4 cm. The mean external fixation index was 39.5 days/cm for the group treated by bone transport, 34.1 days/cm for the shortening-distraction group, and 24.0 days/cm for the group treated by distraction and an intramedullary nail. Functional evaluation gave excellent results in 12 patients, good in five and fair in two. There were ten complications in 19 patients, all of which were successfully treated. We also classified reconstruction using distraction osteogenesis into five types based on the location of the defects after resection of the tumour: type 1, diaphyseal; type 2, metaphyseal; type 3, epiphyseal; type 4, subarticular reconstruction; and type 5, arthrodesis. Our results suggest that reconstruction using distraction osteogenesis provides bone which will develop sufficient biomechanical strength and durability. It is beneficial in patients with an expectation of long-term survival and in growing children.