Results of RS-99 protocol for childhood solid tumors

BACKGROUND

Little was known about the therapeutic result of rhabdomyosarcomas (RMSs) and other malignant tumors until the end of the last century in China. Very few prospective clinical research results have been reported. We designed a RS-99 protocol under close cooperation of a multidisciplinary team including surgeons, radiologists, pathologists, and pediatric oncologists at Shanghai Children's Medical Center. This study aimed to improve the prognosis of childhood solid tumors and analyze the results of different tumors with the same protocol, including RMSs, the Ewing sarcoma family of tumors (ESFTs), and ex-cranial germ cell tumors (GCTs).

METHODS

Sixty-six patients with malignant solid tumors [RMS (n=30), GCT (n=22), and ESFT (n=14)] were enrolled on the RS-99 protocol from October 1998 to October 2006. They were 34 girls and 32 boys aged 9 to 194 months. The protocol involved surgery, radiotherapy and chemotherapy which included VCP (vincristine, cisdiaminedichloroplatinum, and cyclophosphamide) and IEV (etoposide, vincristine and ifosfamide) for the low-risk group, AVCP (adriamycin, vincristine, cisdiaminedichloroplatinum, and cyclophosphamide) and IEV for the intermediate-risk group and high-risk group. Peripheral blood stem cell transplantation was suggested for the high-risk group. Radiotherapy was only given for RMS and ESFT. Differences in survival between the groups were determined by comparison of entire survival curves and tested by the Kaplan-Meier method and the log-rank tests.

RESULTS

The 5-year event-free survival (EFS) for the whole group (RMS, ESFT and GCT) was 60%. The 5-year EFS for children with RMS was 35% (95% CI 16-54), GCT was 79% (95% CI 70-88) and ESFT was 72% (95% CI 58-86). The 5-year EFS showed that the patients with RMS in the retroperitoneum-pelvis did not have a better result than those with tumors in other sites (P=0.604). The histological classification of RMS exerted prognostic influence on the estimated 5-year EFS (P=0.04). Tumor stage and risk group were also contributive to prognosis (P=0.008). For GCT patients, the primary sites of tumors and their histological classification did not influence the therapeutic result (P=0.814). The 5-year EFS was 100% in stage I and II versus 62% in stage III and IV patients (P=0.02). Because of the small number of patients, we did not analyze the prognostic factors for patients with ESFT. No organ failure or functional impairment occurred in the patients enrolled in the RS-99 protocol. One ESFT patient developed a second cancer.

CONCLUSIONS

The RS-99 protocol is well tolerated and is reasonable for the 3 different tumors. Risk-based grouping protocol design is needed and the protocol for high risk RMS should be revised.

[Clinical observation on the treatment outcome of 14 children with hepatoblastoma in a single medical center]

OBJECTIVE

To evaluate the efficacy and safety of the ICE regimen (iphosphamide + carboplatin + etoposide) used in treating children with hepatoblastoma in the Shanghai Children's Medical Center.

METHODS

From June 2000 to June 2008, 14 children with newly diagnosed hepatoblastoma (7 males and 7 females) were enrolled. Their median age on diagnosis was 1.33 years (range: 0.25-8.25 years). Six patients had stage I disease, 1 had stage II, 5 had stage III, and 2 had stage IV diseases. Thirteen children had markedly increased serum AFP level, and 1 had normal serum AFP level. Multidisciplinary co-operation treatment was performed. Eight patients had primary surgery while 3 patients had pre-operation chemotherapy before surgery. ICE chemotherapy regimen was used. Totally, 73 courses of chemotherapy were administered for the 14 children and 25 out of the 73 courses were performed before operation.

RESULTS

Twelve patients responded to the treatment (85.7%) and 2 failed. Ten patients (71.4%) achieved complete remission after treatment, and two had partial remission. By July 31st, 2008, 9 patients survived without any event, with a median follow-up duration of 35 months (range: 16-96 months). The 5-year overall survival rate was 70.71+/-12.37%, and the 5-year event-free survival rate was 64.29+/-12.81%. One patient had disease relapse and two patients were lost to follow-up after they achieved partial remission.

CONCLUSIONS

The ICE regimen combined with operation is effective and safe in treating children with hepatoblastoma.

[Tandem application of flow cytometry and polymerase chain reaction for choice targets of minimal residual disease in childhood acute lymphoblastic leukemia]

OBJECTIVE

Minimal residual disease (MRD) is one of the most important prognostic factors in childhood acute lymphoblastic leukemia (ALL). Flow cytometry and PCR are two common techniques for examining MRD in ALL. This study aimed to identify MRD targets by tandem application of both techniques in children with ALL.

METHODS

From September 2001 to October 2003, 126 children with newly diagnosed ALL were enrolled on the treatment protocol ALL-XH-99. Tandem application of flow cytometry and PCR was performed to identify MRD targets in these patients.

RESULTS

1. Using sets of combined antibodies, immunophenotypic expression of leukemia cells was observed in 95 of 106 B-lineage ALL cases (89.6%). Only one aberrant immunophenotype was observed in 11 cases (11.6%) and most patients with B-lineage ALL (88.4%) expressed at least two suitable targets. 2. Using PCR technique, T-cell receptor (TCR) or immunoglobulin gene rearrangements were identified in 26 of 27 patients (96.3%). Two or more monoclonal/ bi-allelic gene rearrangements were identified in 17 cases (65.4%). The majority (70%) of T-lineage ALL cases contained TCRVgammaI-Jgamma1.3/2.3. Cross-lineage TCR rearrangements were found in 57.1% of cases with B-lineage ALL. 3. Suitable MRD targets of immunophenotypic abnormalities or antigen receptor gene rearrangements were detected in 121 patients (96.0%).

CONCLUSIONS

MRD targets were identified using tandem application of flow cytometry and PCR in almost of children with ALL. Cross-lineage TCR rearrangements and bi-allelic gene rearrangements were observed in many patients.

[Relationship between immunological characteristics and prognosis in children with acute myeloid leukemia]

OBJECTIVE

The prognostic significance of immunophenotyping in acute myeloid leukemia (AML) has been controversial. This study investigated the relationship of immunophenotypes with French-American-British (FAB) subtypes and chromosomal abnormalities and assessed the prognostic value of immunophenotyping in children with AML.

METHODS

From January 1998 to May 2003, 75 children with newly diagnosed AML were enrolled on protocol AML-XH-99. Immunophenotypes were measured with the flow cytometry. According to the McAbs used, the patients were classified into five groups: panmyeloid antigens (CD13, CD33, and MPO), myeloid-lineage associated antigens (CD14, CD15), lineage-specific antigens (CD41, GlyA), progenitor-associated antigens (CD34, HLA-DR) and lymphoid-associated antigens (CD19, CD7). The probability of event-free survival (EFS) was estimated by Kaplan-Meier analysis. The distributions of EFS were compared using the log-rank test. Chi-square analysis or Fisher exact test was used to compare the differences in the distribution of biologic presenting features. A Cox proportional hazards model was used to identify independent prognostic factors.

RESULTS

At least one of panmyeloid antigens CD13, CD33 and MPO was expressed in 72 patents (97.3%). Two or more panmyeloid antigens were expressed in 45 patients (60.8%). The proportion of children with AML expressing one or more of the lymphoid-associated antigens was 24.3%. Lymphoid-associated antigen CD19 was expressed by blast cells in most of FAB M2 patients. The patients with acute promyelocytic leukemia were characterized by the absence of HLA-DR and lymphoid-associated antigens CD19 and CD7. Monovariate analysis showed immunophenotypes were not related to the complete remission rate after the first induction course and the 5-year-EFS. Multivariate analysis suggested immunophenotyping had no independent prognostic value in AML.

CONCLUSIONS

Immunophenotyping can not be used independently in the evaluation of risk classification in children with AML. However, it is useful in the reorganization of special types of AML.

[Effect of protocol RS-99 for childhood rhabdomyosarcoma]

OBJECTIVE

To develop a reasonable protocol for childhood rhabdomyosarcoma (RS) to improve the prognosis of this disease.

METHODS

The protocol RS-99, developed on the base of pathological examination, clinical staging and grouping was used for 30 RS patients, 15 male and 15 female, aged 53 months (15-180 months). For the low-risk patients the regimen VCP and IeV were used alternately for 6 treatment courses and then local radiotherapy was given, for the median and high risk patients, regimen AVCP and IEV were used alternately for 6 courses, local radiotherapy and selective operation were performed, and then DEV and IeV were used alternately for 6 courses, and for the high-risk patients DEV and IeV were used alternately for 18 courses in total and then hematopoietic stem cell transplantation was conducted.

RESULTS

Twenty-three of the 30 patients reached complete response (CR) 17 of which remained in CR for 37 (32-92) months, and 7 of the 30 patients achieved partial response (PR) but their condition worsened later. Relapse was seen in 6 patients 15 (7-38) months later. The 5 year event-free survival (EFS) rate was 47% and the overall survival (OS) rate was 52%. All the 10 stage I and II patients, 5 of the 8 stage III patients, and only 2 of the 12 stage IV patients still remained in CR.

CONCLUSION

The protocol RS-99 is effective on the RS at stages I, II, and III, however, is ineffective on the disease at stage IV.

Prognostic value of early treatment response in children with acute lymphoblastic leukemia: a single institution experience in Shanghai, China

OBJECTIVE

Early response to therapy is one of the most important prognostic factors in childhood acute lymphoblastic leukemia (ALL). This study aimed to assess the prognostic value of morphological assessment of bone marrow blasts during remission induction and determination of minimal residual disease (MRD) after remission induction.

METHODS

From January 1998 to May 2003, 193 children with newly diagnosed ALL were enrolled on the ALL-XH-99 protocol. Blast cell count in the bone marrow was examined on day 19 of remission induction and by the completion of remission induction. MRD was measured with the flow cytometry. Event-free survival (EFS) was estimated by Kaplan-Meier analysis and the distributions of EFS were compared using the log-rank test. A Cox proportional hazards model was used to identify independent prognostic factors.

RESULTS

The 4-year EFS was significantly worse in patients with > or = 5% lymphoblasts in the bone marrow on day 19 as compared to those with <5% lymphoblasts on that date (42.59%+/- 14.28% vs 74.24%+/- 6.67%; p< 0.01). The 4-year EFS was significantly worse in patients with any amount of lymphoblasts in the bone marrow on the remission date as compared to that of other patients with no morphologically identifiable blasts (63.47%+/-9.23% vs 76.41%+/- 6.09%; p<0.05). The patients with MRD <0.01 had significantly better outcome than those with a level > or = 0.01% (15-month EFS:94.44%+/-5.40% vs 23.81%+/- 20.26%; p<0.01).

CONCLUSIONS

Early treatment response as assessed by morphological examination or minimal residual leukemia determination by flow cytometry has important prognostic significance, and can be performed in a resource-poor patient population.

[Clinical importance of minimal residual disease testing in the therapy of childhood B-cell acute lymphoblastic leukemia]

OBJECTIVE

To study the role of minimal residual disease (MRD) in the evaluation of therapeutic effectiveness of childhood B-cell acute lymphoblastic leukemia (ALL).

METHODS

MRD testing was performed in 124 children with B-cell ALL, who were newly diagnosed and enrolled in the ALL-XH-99 treatment protocol from September 2001 to April 2005MRD was determined by 4-color flow cytometry in the different time points during the treatment period.

RESULTS

After induction therapy, 103, 13 and 8 patients showed MRD <0.01%, 0.01%-0.1% and >0.1%, respectively. The 5-year relapse-free survival (RFS) in the patients with MRD <0.01%, 0.01%-0.1% and >0.1% was 88.9+/-3.9%, 70.0+/-14.5% and 0%, respectively and the 5-year event-free survival (EFS) was 82.4+/-4.4%, 21.2+/-18.0% and 0%, respectively. There were significant differences in the RFS and EFS among the patients with different MRD levels (P<0.01). Within half a year after induction remission, the 5-year RFS in patients with MRD negative (<0.01%) and positive was 87.7+/-4.1% and 58.3+/-14.2%, respectively (P<0.01) and the 5-year RFS was 80.7+/-4.6% and 25.6+/-13.8%, respectively (P<0.01). After half a year with induction remission, the patients with MRD negative and positive also showed statistical differences in the 5-year RFS (92.0+/-3.6% vs 48.5+/-15.5%; P<0.01) and EFS (85.6+/-4.5% vs 21.4+/-11.0%; P<0.01). Multivariate analysis confirmed that the MRD level after induction chemotherapy together with the reaction to prednisone, the bone marrow features on the 19th day of induction, and the fusion gene with BCR-ABL or MLL-AF4 had prognostic significance in childhood B-cell ALL.

CONCLUSIONS

The MRD level in the whole course of therapy is an important outcome indicator in childhood B cell ALL.

[Effectiveness of the AML-XH-99-M3 protocol for treatment of acute promyelocytic leukemia in children]

OBJECTIVE

To evaluate the effectiveness of AML-XH-99-M3 protocol for treatment of acute promyelocytic leukemia (APL) in children.

METHODS

Thirty-three children with APL received AML-XH-99-M3 protocol treatment. The event-free survival (EFS), disease-free survival (DFS), and overall survival (OS) were evaluated by the Kaplan-Meier medthod with SPSS13.0 software.

RESULTS

Thirty patients (90.9%) achieved a complete remission (CR) after one course of treatment. The total CR rate was 100%. Six patients (18.2%) relapsed in an average of 29.17 months (16-38 months). Two patients (6.1%) died. The 7-year EFS and DFS in the 30 patients were 73.4+/-9.4%. The overall survival rate was 91.2+/-6.0%. The difference of EFS was observed in patients receiving intermittent all-trans-retinoic acid (ATRA) administration or not in the maintenance therapy (88.9+/-10.5% vs 62.5+/-13.6%) (P<0.05).

CONCLUSIONS

The AML-XH-99-M3 protocol for the treatment of APL produced a higher CR rate and higher EFS, DFS and OS rates in children. Intermittent administration of ATRA in the maintenance therapy can improve EFS rate.

[Prognostic factors for childhood acute non-mature B-lymphoblastic leukemia]

OBJECTIVE

To study the prognostic factors for events-free survival (EFS) in children with acute non-mature B-lymphoblastic leukemia.

METHODS

One hundred and sixty-one children with newly diagnosed acute non-mature B-lymphoblastic leukemia received the ALL-XH-99 protocol treatment. Their medical data, including clinical, biological and molecule features, early responses to treatment (bone marrow evaluation on the 19th day of induction therapy), minimal residual disease (MRD) in bone marrow after remission induction therapy, the risk grade of disease before the beginning of chemotherapy and the outcome, were retrospectively studied.

RESULTS

Univariable analysis indicated that the gender and P170 levels before therapy had no effect on the outcome. Age, initial white blood cell count (WBC), prednisone response, early response to treatment, fusion genes (BCR/ABL or MLL/AF4) and MRD level were significantly related to the EFS (P<0.01). Immunophenotype, myeloid-associated antigen and the risk grade of disease were also related to the EFS (P<0.05). Multivariable analysis showed that WBC >or=50 x 10(9)/L, Cmu positive, BCR/ABL or MLL/AF4 positive and MRD positive (>or=0.01%) were risk factors for the poor prognosis (P<0.01). The early response to treatment was important to modify the therapy protocol.

CONCLUSIONS

WBC >or=50 x 10(9)/L, Cmu positive, BCR/ABL or MLL/AF4 positive and MRD positive have important prognostic values in childhood acute non-mature B-lymphoblastic leukemia. Early response to treatment is an important index for modifying the chemotherapy protocol.

[Genetic polymorphisms and genetic effects of IGF2 gene in pigs]

Single nucleotide polymorphisms of the exon7, 8, 9 of the porcine IGF2 gene were tested using PCR-SSCP. Genetic effects of the IGF2 gene on birth weight, weaning weight, six-month weight and six-month backfat thickness were analyzed. On the basis of the published DNA sequence (AY044828) of the porcine IGF2 gene, three pairs of primers were designed, and one polymorphism, three genotypes were found in the PCR product amplified with Ex8 primers. C-->T transition at 53 site of exon8 was detected by sequencing the homozygotes. The results showed that: firstly, the genotype distribution was not consistent among the different pig breeds. No significant differences (P > 0.05) were found in the genotype distribution when compared the Landrace with the Large White , the Laiwu with the Dapuliang, and the Yimeng with the Licha Black pig breeds, whereas significant differences (P lt; 0.01) were found among other tested pig breeds in the genotype distribution. Secondly, on the basis of the fixed effect model, significant differences (P lt; 0.05) were found in birth weight and six-month backfat thickness, whereas no significant differences (P > 0.05) existed in weaning weight and six-month weight. Thirdly, using least square analysis, it was shown that individuals of the BB genotype have significantly lower (P lt; 0.05) birth weight than those of AA and AB genotypes, with the order being AB > AA > BB ; Individuals of the AA genotype have significantly lower (P lt; 0.05) six-month backfat thickness than those of AB and BB genotypes, with the order being BB > AB > AA. These results suggest that IGF2 gene has significant effects on individual birth weight and backfat thickness. The IGF2 gene can be used in marker-assisted selection to accelerate the breeding progress.

Effects of the MyoG gene on the partial growth traits in pigs

Single-nucleotide polymorphisms of the MyoG gene were tested using PCR-SSCP in different pig breeds including Landrace, Large White, Duroc, Shanxi Black, and Mashen pigs, and the effects of the MyoG gene on the birth weight, the weaning weight, the 6-month body weight, and the backfat thickness were also analyzed. On the basis of the published sequence of the porcine MyoG gene, ten pairs of primers were designed, and one polymorphism was found in the PCR product amplified with In2-3 primers. The results showed that: (1) the Landrace, the Large White, and the Duroc breeds differ significantly (P < 0.05) in genotype distribution from the Shanxi Black and the Mashen breeds; (2) On the basis of the fixed effect model, significant differences were found in the birth weight and the backfat thickness among the different MyoG genotypes, whereas no significant differences existed in the weaning weight and the 6-month body weight; (3) Using least square analysis, it was seen that individuals of the BB genotype had significantly less (P < 0.01) birth weight than those of the AA and AB genotypes, with the order being AA>AB>BB; the pigs of the AA genotype had significantly lower (P < 0.01) backfat thickness than those of the AB and BB genotypes, with the order being AA<AB<BB. These results suggest that the genotype has significant effects on the individual birth weight and the backfat thickness, and that the selection of the A allele is favored with regard to the birth weight and the backfat thickness.

[Asparagine synthetase activity in pediatric acute lymphoblastic leukemia]

OBJECTIVE

To study the cellular activity of asparagine synthetase in different types of childhood acute lymphoblastic leukemia (ALL).

METHODS

The cellular activity of asparagine synthetase was detected by HPLC-FLD and Protein measurement in 28 ALL children (7 cases of T-ALL and 21 cases of B-lymphoid lineage ALL) before chemotherapy.

RESULTS

The asparagines synthetase activity levels in T-ALL children were significantly higher than those of the B-lymphoid lineage ALL patients, with the median activity level of 9.3 nM Asn/mg protein/hr vs 5.2 nM Asn/mg protein/hr (P < 0.05). The distribution of the asparagine synthetase activity demonstrated a polymorphism in either T-ALL or B-lymphoid lineage ALL patients.

CONCLUSIONS

The cellular activity of asparagines synthetase in ALL patients is presented with a polymorphism distribution. The asparagines synthetase activity levels in T-ALL are significantly higher than in B-lymphoid lineage ALL.

[Response rate of AML-XH-99 protocol in the treatment of 82 childhood acute myeloid leukemia]

OBJECTIVE

To evaluate the outcomes of childhood acute myeloid leukemia (AML) treated with AML-XH-99 protocol and explore how to improve the event-free survival (EFS) rate.

METHODS

Eighty-two patients entered AML-XH-99 clinical trial. Survival rates were evaluated by Kaplan-Meier method with SPSS.

RESULTS

Among the 82 patients, 58 (70.7%) achieved complete remission (CR) after one course treatment, and the total CR rate was 84.1%. The overall 5 year EFS rate was (46.1 +/- 9.1)% and disease-free survival (DFS) rate was (54.3 +/- 10.3)% over a median observation period of 23 months. The 5 year EFS rate of 56 patients received high-dose cytarabine(HD-Ara-C) as intensification therapy was (47.2 +/- 12.9)%. Relapse occurred in 19 patients (26.0%) with a median time of 10 months (ranges 2 approximately 53 months), 28 patients died.

CONCLUSION

AML-XH-99 protocol resulted in a higher CR rate, especially one course CR rate, which was one of the key factors for long-term EFS and HD-Ara-C intensification therapy was effective in the treatment of childhood AML.

[Characterization of CD10 expression and its significance in minimal residual disease detection in childhood B-acute lymphoblastic leukemia]

To observe the expressions of CD10 in childhood B-acute lymphoblastic leukemia (B-ALL) and to define the role of CD10 in minimal residual disease (MRD) detection. 58 cases of childhood B-ALL were studied in this program. Four-color flow cytometry was used to analyze the characteristics of B-ALL phenotypes. The four-color fluorochrome labeled antibody combinations of CD10 with other markers were used to detect MRD. The results showed that CD10 overexpression (CD10(bright)) was detected in 65.5% (38/58) of B-ALL patients and a strong correlation between CD10(bright) and CD34 expression was also observed, i.e. CD10(bright) expression most frequently happened in B-ALL with high percentage of CD34 positive cells. In detection of MRD, CD10(bright), combined with other markers, could effectively distinguish normal cells with leukemic cells, even if there was no any other marker that can be used. It is concluded that CD10(bright) expression correlates with high expression of CD34 in B-ALL, it is a good marker for MRD detection. The combination of CD10 and other markers can be applied in B-ALL MRD detection with flow cytometry.

Fas receptor (CD95)-mediated apoptosis is induced in leukemic cells entering G1B compartment of the cell cycle

Apoptotic cell death induced by cross-linking Fas receptor (FasR/CD95) has been investigated in human acute myelogenous leukemia (AML) cells. FasR-mediated growth inhibition and DNA fragmentation could be induced in certain cases of AML. Interestingly, when DNA synthesis and G1 -> S transition in the cell cycle were enhanced by interleukin-3 or granulocyte-macrophage colony-stimulating factor, Fas-insensitive blast cells acquired cellular susceptibility toward FasR-mediated growth inhibition. To further evaluate an association between the Fas-R-mediated action and a specific phase of the cell cycle, a FasR+ leukemic cell line, MML-1, was established from a patient with AML. The morphologic feature of dying cells and DNA fragmentation indicated that FasR cross-linking induced apoptotic cell death in MML-1 cells. Cell cycle arrest in G1A phase with the treatment of phorbol 12-myristate 13-acetate or thymidine rendered MML-1 cells resistant to FasR-mediated apoptosis without downregulation of surface FasR expression. However, S-phase arrest with 5-fluorouracil could neither enhance nor inhibit FasR-mediated apoptosis. Simultaneous DNA/RNA quantification analysis revealed the selective loss of cells in G1B compartment, accompanied by the increase of apoptotic nuclei in sub-G1 fraction. These findings suggested that FasR-mediated apoptotic signals could be transduced into cells in G1B compartment and G1A -> G1B transition might augment the induction of FasR-mediated apoptosis.

Use of ultrasonography in the diagnosis of dysbaric osteonecrosis

Comparisons between x-ray and B-mode ultrasonic examinations were carried out in 32 divers in both shoulders and both hips (128 comparisons in all). The x-rays showed dysbaric osteonecrosis (DON) in 46 sites; in 43 of these, the B-mode ultrasonogram result coincided with the x-ray finding. We suggest that B-mode ultrasonograms can depict the location, form, and size of the lesions. It is an easy, efficient, and noninvasive method of diagnosing DON, worthy of further investigation and application. Similar good agreement between x-rays and ultrasonograms was found with the now-obsolete A-mode technique.

Distribution of lesions in the head and neck of the humerus and the femur in dysbaric osteonecrosis

In a prospective investigation of 164 cases of dysbaric osteonecrosis out of a total of 1269 hyperbaric workers, we found that lesions are apt to occur more frequently in some sites of the head and neck of the femur and humerus than in others. Defining the susceptibility of sites with radiographs has improved our ability to make early diagnoses because we are able to estimate the likelihood of a definite lesion of osteonecrosis developing. We have found that when the trabeculae in a susceptible site appear disordered or have translucent areas, the site often develops into osteonecrosis in a few years.

Ethanol treatment for acute decompression sickness in rabbits

Rabbits developed acute decompression sickness after staying at 6 ATA for 30 min followed by decompression to 1 ATA in 20 min or less. If the rabbits received an i.v. injection of 25% ethanol upon surfacing, all survived, whereas half the untreated control group died within 15-35 min after decompressing. In ethanol-treated animals, no bubbles were seen in blood vessels of visceral organs, muscles, and subcutaneous tissues at autopsy 60 min after treatment. Decompression reduced platelet counts markedly in all rabbits, but in the control group the count stayed low, whereas with ethanol treatment the counts had reached the precompression level after 1 h and 24 h.

Dysbaric osteonecrosis and its radiographic classification in China

Dysbaric osteonecrosis was found in 259 cases among 2260 examined hyperbaric workers from several occupations. No positive cases were found in the divers in shipyards and diving experiments. Naval divers showed the lowest incidence (2.1%) and fishery divers the highest (19.8%). Distribution of long bone lesions was 46.0% in upper humerus, 37.7% in upper femur, 8.3% in lower femur, and 8.0% in upper tibia. We classify long bone lesions into three radiographic stages, the first two on the basis of size of the bone lesions as projected on the radiographs, and the third stage on the basis of extension of the lesion toward articular destruction. The three-stage classification system correlates with the clinical symptoms, and the working capacity of the individual patients tends to correlate with the severity of dysbaric osteonecrosis and can be understood by the general public.