Laser cooling of a solid by 21K starting from room temperature

A fluorozirconate glass doped with trivalent ytterbium ions has been laser cooled in vacuo from 298 to 277 K by optical pumping of the ions at 1015 nm. The cooling effect arises from anti-Stokes fluorescence of the laser-excited ions and by virtue of the near-unit fluorescence quantum efficiency for Yb(3+) in sufficiently pure solid hosts. The sample temperatures in the experiment are determined by measurement of the Yb(3+) emission spectrum; the value of the observed temperature change from room temperature as a function of pump wavelength is successfully explained in terms of a simple two-level model that includes the effect of optical saturation.

Relationship between topotecan systemic exposure and tumor response in human neuroblastoma xenografts

BACKGROUND

Topotecan is a topoisomerase I inhibitor with activity against xenografts of childhood solid tumors and established clinical activity against neuroblastoma and rhabdomyosarcoma. We have studied the relationship between systemic exposure to and the antitumor activity of topotecan lactone (the active form of the drug) in the xenograft models. Furthermore, we determined whether the responses seen in these models occur at systemic exposure levels that are tolerable in children.

METHODS

Neuroblastoma xenografts derived from the tumors of six different patients were established subcutaneously in immune-deprived mice. Topotecan was administered by intravenous bolus injection 5 days a week for 2 consecutive weeks, repeated every 21 days for three cycles. The minimum daily doses that induced complete responses (CRs) and partial responses (PRs) were determined. Topotecan lactone pharmacokinetic studies were performed in both tumor-bearing and nontumor-bearing mice.

RESULTS

The minimum doses associated with CRs and PRs in four of the six neuroblastoma xenografts were 0.61 and 0.36 mg/kg body weight, respectively. The topotecan lactone single-day systemic exposures associated with these doses were 88 and 52 ng x hr/mL, respectively. There was an approximately sixfold difference in topotecan lactone systemic exposure (290 ng x hr/mL versus 52 ng x hr/mL) associated with achieving CRs in the least-sensitive and most-sensitive tumors, respectively.

CONCLUSIONS

Neuroblastoma xenografts are highly sensitive to topotecan therapy, and responses in mice are achieved at systemic exposures similar to those that are clinically effective and tolerable in children. These results support the concept of deriving preclinical data relating systemic exposure to antitumor activity in xenograft models. Such data may be valuable in making informed decisions regarding the clinical development of new agents.

Patient satisfaction after limb-sparing surgery and amputation for pediatric malignant bone tumors

We surveyed 65 patients age 13 years or older who had been treated for malignant bone tumors and were in remission at least 1 year after limb-sparing surgery (LS) or amputation (AMP) to assess general satisfaction with the surgical outcome and its impact on various areas of functioning. Of 130 eligible patients, 65 responded (61 treated for osteosarcoma, 3 for Ewing's sarcoma, and 1 for mesenchymoma). The median current age of the cohort was 25.8 years (range, 14.2 to 47.5 years). The median time from surgery was 14.2 years (range, 4.0 to 30.4 years) for the AMP group, and 5.5 years (range, 2.0 to 13.8 years) for the LS patients. Questionnaire responses of patients treated with AMP compared to those who had LS surgery showed no significant differences in the impact of the surgical procedure on educational and occupational status, functional limitations, pain intensity and degree of pain interference, emotional distress, interpersonal/social interactions and self-image, rehabilitation experience, and overall satisfaction with the surgical procedure. Functional limitation was significantly related to pain interference, as well as emotional distress, self-image, and interpersonal difficulties for the entire cohort. Our findings highlight procedure-related advantages and difficulties that may potentially enhance decision making regarding the selection of the surgical procedure for individual patients with malignant bone tumors of an extremity.

Evidence of ED-B+ fibronectin synthesis in human tissues by non-radioactive RNA in situ hybridization. Investigations on carcinoma (oral squamous cell and breast carcinoma), chronic inflammation (rheumatoid synovitis) and fibromatosis (Morbus Dupuytren)

The splicing variant of fibronectin containing the ED-B domain (oncofoetal fibronectin) occurs in foetal tissues, reparative processes, organ fibrosis and in tumour tissues. Consequently, a supportive effect of ED-B+ fibronectin for tissue remodelling and tumour progression is assumed. A non-radioactive RNA-RNA in situ hybridization protocol for the investigation of ED-B+ fibronectin synthesis applicable in human tissues is introduced. The ED-B+ fibronectin synthesis was investigated in human disease processes, for which the occurrence of ED-B+ fibronectin is well demonstrated by immunohistochemistry (rheumatoid arthritis, oral squamous cell carcinoma, invasive ductal carcinoma of the breast and nodular palmar fibromatosis). The ED-B+ fibronectin synthesis could be shown in lining cells and in endothelial cells of synovial villi in rheumatoid arthritis, in stromal cells of oral squamous cell carcinoma and invasive ductal carcinoma and in fibro-/myofibroblasts in the proliferative and early involutional phase of nodular palmar fibromatosis. By means of double labelling (alpha-smooth muscle actin immunostaining - ED-B+ fibronectin in situ hybridization), the ED-B+ fibronectin synthesis could be shown to be a typical feature of myofibroblasts. In contrast to the often diffuse ED-B+ fibronectin immunostaining, only a few synthetically active stromal cells were observed focally accentuated within the tumour, which were interpreted as hot spots of tumour-stroma interaction.

[A rapid simple and reliable method for sequencing the targeted gene of shuttle vector pSP189]

The authors established a simple, rapid and effective procedures for sequencing the targeted a-gene SupF TRNA of shuttle vector pSP189, which is very important and useful in molecular mechanism research of mutagens. In this method, double-stranded plasmid DNA as template, prepared single-stranded DNA with alkali denaturation, applied r-32P-ATP for labelling 5'-end of primer, were used. A satisfactory result was achieved.

Studies of the efficacy and pharmacology of irinotecan against human colon tumor xenograft models

Irinotecan, administered i.v. on days 1-5 and 8-12 [(dx5)2 i.v.] has demonstrated significant activity against advanced human tumor xenografts. To explore the feasibility of prolonged oral administration of irinotecan, we compared the efficacy of oral and i.v. irinotecan on the (dx5)2 schedule. We also evaluated oral therapy for 12 consecutive weeks [(dx5)12] at 25 and 50 mg/kg and two consecutive 5-day courses repeated every 21 days for up to four cycles ([(dx5)2]4) at 50 and 75 mg/kg/dose in a series of human colon carcinoma xenograft lines. In addition, we evaluated the effect of a sensitive (HC1) and resistant (ELC2) human colon adenocarcinoma xenograft on irinotecan and SN-38 lactone disposition after administration of irinotecan 10 mg/kg i.v. and 10 and 25 mg/kg p.o. Irinotecan i.v. at 40 mg/kg and oral at 50 and 75 mg/kg on the (dx5)2 schedule had similar activity against the panel of adult colon adenocarcinoma xenografts. Irinotecan given p.o. also demonstrated significant activity against a topotecan-resistant derivative, VRC5/TOPO. Oral administration of 75 mg/kg [(dx5)2]4 and 50 mg/kg (dx5)12 achieved complete response in five of seven xenograft lines evaluated. After i.v. administration, mice bearing HC1 xenografts had 43% greater SN-38 lactone systemic exposure compared to those with ELC2 xenografts and non-tumor-bearing mice. After oral (10 mg/kg) administration, there was a 5-fold higher molar formation of SN-38 lactone compared to i.v. (10 mg/kg) administration in tumor and non-tumor-bearing mice. SN-38 systemic exposure associated with the lowest oral dose (25 mg/kg) achieving complete response for HC1 was 942.6 ng/ml x h. These results emphasize the importance of pharmacokinetic studies as part of tumor response studies in xenograft models.

Late vascular occlusion of central lines in pediatric malignancies

OBJECTIVE

To determine whether thrombi or vascular occlusion represent a late complication persisting several years after removal of central venous lines (CVLs) in children and adolescents treated for childhood cancer.

METHODS

Children whose treatment for malignancy included placement of a CVL that had been removed at least 2 months previously were studied during scheduled follow-up that included contrast-enhanced computed tomography. Spiral volume acquisition was used to obtain 3-mm images from the chest apices through the right hilum, and three-dimensional reconstruction of angiograms was performed. Thrombosis/occlusion was defined as narrowing, obstruction, or filling defect of the deep venous system, with or without the formation of collateral veins. Charts were reviewed to document patient characteristics, previous CVL complications, administration of hyperalimentation, use of urokinase, and family history of venous thrombosis.

RESULTS

Twenty-three patients treated for solid tumors and 2 treated for B-cell acute lymphocytic leukemia or lymphoma were studied. Lines had been in place from 0.2 to 36 months (median, 7.4) and were removed at 2.3 to 121.8 months (median, 32.5) before study. Nine patients received hyperalimentation for periods ranging from 2 to 38 weeks (median, 12). Four patients had required urokinase instillations, and one developed superior vena cava syndrome; 4 had a CVL-related infection (two superficial and two Candida line infections). Occlusion was seen on computed tomography angiograms in 3 of the 25 patients (12%; 95% confidence interval: 4.5-31%). One of the patients with occlusion had superior vena cava syndrome; none had a family history of thrombosis, use of a double lumen CVL, or multiple instillations of urokinase.

CONCLUSIONS

Persistent asymptomatic vascular occlusion does occur as a late complication of CVL placement for treatment of childhood malignancies, although the frequency appears low among patients treated primarily for solid tumors. Prospective studies of large numbers of patients with a broader spectrum of diagnoses are necessary to define the incidence of and risk factors for this complication and to assess the need for prevention with anticoagulation or other therapy. Pediatricians caring for patients with a history of cancer and CVLs should be aware that these patients may have persistent vascular occlusion that could predispose them to recurrent thrombosis or postphlebitic syndrome.

Clinical effects and pharmacokinetics of the fusion protein PIXY321 in children receiving myelosuppressive chemotherapy

A hemopoietin with the ability to accelerate both platelet and granulocyte recovery after intensive chemotherapy would have great clinical utility. The recombinant fusion protein composed of human granulocyte-macrophage colony-stimulating factor and interleukin-3 (PIXY321), showed some promise in early adult trials. However, studies for pediatric patients are limited, and there are no systematic data on the pharmacokinetics of PIXY321 given over prolonged periods at current dosage levels.

PURPOSE

To determine the safety, clinical effects and plasma concentrations of increasing doses of PIXY321 in children treated with myelosuppressive chemotherapy.

METHODS

A total of 39 children with relapsed or high-risk solid tumors were enrolled in this phase I/II study. PIXY321 was administered once or twice daily by subcutaneous injection in total doses of 500 to 1000 microg/m2 per day for 14 days after each course of chemotherapy with ifosfamide, carboplatin, and etoposide (ICE). Pharmacokinetic studies were performed on day 1 of the first course in 33 patients and repeated on day 14 in 13 patients (once-daily schedule only).

RESULTS

Although mild local skin reactions and fever were frequent, no dose-limiting toxicity was identified at the maximum dose studied (1000 microg/m2 per day). There were no statistically significant differences in chemotherapy-induced hematologic toxicity with increasing doses of PIXY321 or with twice-daily vs once-daily dosing. On day 1, the median PIXY321 clearance was 657 ml/min per m2 (range 77 1804 ml/min per m2) and the median half-life was 3.7 h (range 2.1-20.8 h). On day 14, clearance increased in all patients studied (median increase 63%), with a corresponding decrease in the median 12-h concentration (from 1.2 to 0.25 ng/ml). Maximum concentrations were < 1 ng/ml in 81% of patients, and only two patients had maximum plasma concentrations equivalent to those required for consistent activity in vitro.

CONCLUSIONS

The recombinant fusion protein PIXY321 proved safe in children treated with myelosuppressive ICE chemotherapy but had no demonstrable clinical benefits. The pharmacokinetic studies suggest that the observed lack of hematologic benefit may be explained by low plasma concentrations resulting from increased clearance with prolonged administration. Moreover, the significant increase in PIXY321 systemic clearance in the absence of increased circulating myeloid cells suggests that the upregulation of either extravascular compartment hematopoietic progenitor cells or nonhematopoietic cells may play an important role in controlling circulating concentrations of this unique cytokine. These findings highlight the importance of a thorough assessment of the systemic disposition of cytokines when determining the dose and schedule necessary to achieve clinical activity in patients.

Probenecid alters topotecan systemic and renal disposition by inhibiting renal tubular secretion

Topotecan is primarily eliminated by the kidneys, with 60 to 70% of the dose recovered as topotecan total in the urine. To elucidate the mechanisms of topotecan renal clearance, we evaluated the effect of probenecid on topotecan renal and systemic disposition in mice. Topotecan lactone or hydroxy acid (1.25 mg/kg i.v.) was administered alone or in combination with probenecid (600 or 1,200 mg/kg) given by oral gavage 30 min before and 3 hr after topotecan. Serial blood samples (three mice per time point) and urine samples (five mice per treatment arm) were collected during a 6-hr period. Compared with topotecan alone, coadministration of topotecan lactone or hydroxy acid with probenecid (600 mg/kg) decreased topotecan lactone, total, and hydroxy acid systemic clearance, and total renal clearance. The predominant effect of probenecid was to increase hydroxy acid area under the plasma concentration time curve after administration of topotecan lactone (238.8 vs. 109.9 ng.hr/ml alone, P < .05), or hydroxy acid (1297.2 vs. 355.0 ng.hr/ml alone, P < .05). By inhibiting renal tubular secretion, probenecid decreased renal and systemic clearance which led to an increase in topotecan systemic exposure. These data suggest that probenecid primarily inhibited secretion of the anionic hydroxy acid form, and by direct or indirect mechanisms increased topotecan lactone systemic exposure. Topotecan elimination through renal tubular secretion may have clinical relevance for the use of topotecan in patients with altered renal function.

[The influence of pressure on human lamina cribrosa cell and its collagen synthesis]

OBJECTIVE

To study the influence of pressure on human lamina cribrosa cell (HLC) and its synthesis of collagen.

METHOD

HLCs were cultured in vitro and submitted to elevated hydrostatic pressure, their changes in morphology were observed by light and electron microscopy and their synthesis of collagen was measured with fluorescence spectrophotometer.

RESULTS

Under a hydrostatic pressure of 6.67 kPa (1 kPa = 7.5 mmHg), the flat and polygonal HLCs became elongated. Vacuoles appeared in the cytoplasm and increased as the pressure persisted. The mitochondria were swollen, some of them turned into vacuoles, and myelin figures were found in the cytoplasm. When exposed to elevated pressure for 3 days, the amounts of synthesized collagen type I, III, IV were 43.95 +/- 6.37, 61.35 +/- 10.35 and 82.90 +/- 11.36 arbitrary unit (AU) by fluorometry respectively, and compared to controls, they were statistically significantly (P < 0.05) increased; after 5 days of pressure exposure, the amounts were 33.50 +/- 6.94, 40.85 +/- 12.30 and 80.45 +/- 14.65 AU, e.g., still increased.

CONCLUSION

It is indicated that under pressure, HLCs undergo obvious morphological changes and increase their synthesis of collagen types I, III and IV.

Treatment of children with peripheral primitive neuroectodermal tumor or extraosseous Ewing's tumor with Ewing's-directed therapy

PURPOSE

We report the treatment and outcome of patients with peripheral primitive neuroectodermal tumor (PNET) and extraosseous Ewing's tumor (EOE) using Ewing's-directed therapy, including an ifosfamide and etoposide window.

METHODS

Seventeen pediatric patients with peripheral PNET (n = 14) or EOE (n = 3) were enrolled between 1988 and 1992 on our institutional Ewing's protocol. Induction therapy comprised a 9-week "window" of ifosfamide and etoposide, followed by 9 weeks of therapy with cyclophosphamide and Adriamycin (Adria Laboratories, Columbus, OH). Response assessment after 17 weeks was followed by surgery and/or radiotherapy (doses based on tumor size and response to induction), repeat evaluation, and maintenance chemotherapy with alternating courses of vincristine/dactinomycin, ifosfamide/etoposide, and cyclophosphamide/Adriamycin for a total of 45 weeks.

RESULTS

At diagnosis, 8 patients had large lesions (>8 cm) and 3 had pulmonary metastases (1 with large tumor). Surgical resection was performed at diagnosis for 9 patients and after induction therapy for 5. During window therapy, all of the 9 evaluable patients responded (8 partial, I objective), and no patient without measurable disease developed disease progression. Responses were maintained or improved during subsequent induction in six of the patients with residual disease. Fourteen patients received local radiotherapy. At 49 to 94 months after diagnosis, 12 patients are disease-free (1 in second remission), 4 have died, and 1 is alive with disease. The five-year overall and progression-free survival rates are 77 +/- 13% and 62 +/- 16%, respectively.

CONCLUSION

The use of consistent Ewing's-directed combined-modality therapy for patients with soft tissue peripheral PNET/EOE results in survival similar to that of patients with osseous Ewing's tumor. The combination of ifosfamide and etoposide appears active and should be incorporated in future treatment protocols.

Protein tyrosine phosphatase gene expression analysis in Swiss 3T3 fibroblasts

The aim of this study was to identify protein tyrosine phosphatases (PTPs) expressed in Swiss 3T3 fibroblasts and to examine their expression levels as well as to characterize quantitative aspects of RT-PCR based on degenerate deoxyoligonucleotides. By using an RT-PCR assay based on degenerate deoxyoligonucleotide primers, expression of mRNAs for two cytoplasmic- and six transmembrane-type PTPs in Swiss 3T3 cells was detected. The sequences of two of them are new. Among nine analyzed PTPs expressed to widely varied extends, only three have mRNA levels high enough to be seen on Northern blots with 10 microg of total RNA per lane. The frequencies with which the examined PTPs are represented among the PCR amplification products, correlate stronger with the primer fidelity, defined as the number of mismatches between the primer- and the cDNA target-sequences, rather than with the PTP expression levels. In conclusion, an RT-PCR assay based on degenerate primers can be successfully used to sample the expressed PTPs and to identify new members of this gene family. However, reliable quantification of their mRNA levels can only be achieved using the classical approaches, like Northern, RNase protection assay or nondegenerate quantitative RT-PCR.

Comparison of cytokines in children with recurrent solid tumors treated with intensive chemotherapy

PURPOSE

To compare the relative hematopoietic protective effects of recombinant human interleukin-1alpha (rhuIL-1alpha), recombinant human granulocyte macrophage colony-stimulating factor (rhuGM-CSF), and PIXY321, a genetically engineered fusion protein combining interleukin-3 and rhuGM-CSF, in children with refractory solid tumors after treatment with ifosfamide, carboplatin, and etoposide (ICE).

PATIENTS AND METHODS

A total of 53 children who had not responded to at least one earlier chemotherapy regimen were enrolled on consecutive trials of ICE chemotherapy alone (n = 14) or with rhuGM-CSF (n = 8), rhuIL-1alpha (n = 10), or PIXY321 (n = 21). The relative hematopoietic effects of these three cytokines were compared retrospectively to each other and to values for patients who received ICE alone. Because one cannot assume that hematopoietic toxicity and response to a given cytokine are independent of the course of chemotherapy, the analysis was restricted to the first treatment course.

RESULTS

In this retrospective comparison, 1000 microg/m2/day of rhuGM-CSF reduced the median duration of grade 4 neutropenia (<500/microL) from a median of 17 days (range 3 to 34) in children who received ICE alone to 9 days (range 5 to 11, p = 0.003); it appeared to have a beneficial effect on severe thrombocytopenia (<20,000/microL), reducing the median duration from 4.5 days with ICE alone to 3 days (p = 0.08) and the number of platelet transfusions from a median of 5.75 transfusions (range 0 to 13) to 0 in these two cohorts. No significant improvement in these measures was seen with rhuIL-1alpha or PIXY321.

CONCLUSIONS

This analysis suggests that 1000 microg/m2/day of rhuGM-CSF has clinically significant effects on platelet recovery and more effectively ameliorates thrombocytopenia and neutropenia than either rhuIL-1alpha or PIXY321 in the context of ICE chemotherapy. Further dose-intensification will require a combination of cytokines; the optimal dose and combination of these agents awaits further study.

[The effect of the mold temperature on the mechanical properties and reaction layer structure of the titanium castings]

Titanium is very reactive at the high temperature, easily oxidized, and reacts with investment components. The mold temperature is an important factor on the quality of the titanium castings. The paper investigated the effect of the mold temperature on the mechanical properties and reaction layer structure of the titanium castings with the tensile test and modern surface analysis technique. The results indicated that the tensile strength and yield strength of titanium castings increased but elongation rate decreased, and the hardness layer become thicker when the mold temperature raised. The hardness layer of titanium castings was 50 microns for the room temperature mold, 125 microns for the 850 degrees C mold. SX-macro electric probe analysis indicated the spreading depth of Zr, Al elements on the surface of titanium castings was not increased when the mold temperature raised, but, the spreading depth of Si element became deeper on the surface of titanium casting, Si layer was about 30 microns for the room temperature mold, 40 microns for the 250 degrees C mold, 50 microns for the 450 degrees C mold, 70 microns for the 650 degrees C mold, 90 microns for the 850 degrees C mold. So, it is necessary to consider the effect of the mold temperature on the qualities of titanium castings when titanium castings for prosthodontics were made in clinic.

[The influence of teeth positions to lower complete denture retention and health of supporting tissues]

Three kinds of three dimension finite element models of edentulous mandibile and the complete denture were established to investigate the influence of artificial teeth positions to denture retention and the supporting tissue. Ten myodynamic and traditional complete dentures were constructed to compare the difference of artificial teeth positions to alveolar ridge. The results indicated: 1. The stress was not obvious different in mandible when teeth were placed over the crest of the ridge or moved lingually or buccally to the ridge in 3 mm; 2. Under occlusion force, it was beneficial for the lower supporting tissue with artificial molars being placed over the slope of mandible and beneficial for denture retention with molars teeth being placed on the crest of ridge buccally; 3. With the effects of oral muscles, the teeth on the crest of ridge buccally or lingually in 3 mm in molar and premolar regions were respectively available; 4. There were obvious difference in arch width of artificial teeth arrangement between traditional and myodynamic complete dentures, the arch was wider in myodynamic complete denture than that of traditional complete denture at molar region.

Comparison of primary osteosarcoma of flat bones with secondary osteosarcoma of any site

BACKGROUND

The authors hypothesized that the outcomes for young patients who present with primary osteosarcoma of flat bones or secondary osteosarcoma after other primary malignancies are similar because the sites of these tumors rarely makes them amenable to complete surgical resection.

METHODS

The authors reviewed their experience with 27 patients with primary osteosarcomas involving flat bones and 18 patients with secondary osteosarcomas of any site, evaluating treatment, metastatic patterns, and outcome.

RESULTS

Eleven of the 27 primary osteosarcomas and 10 of the 18 secondary osteosarcomas were at least partially resectable at the time of initial diagnosis. At last follow-up, 10 of the 27 patients with primary flat bone osteosarcoma were alive, eight of whom were disease free. Three of 18 with the secondary osteosarcoma patients were alive, including one with locally recurrent disease after recent disease resections. Chemotherapy with single or combinations of agents rarely yielded responses for primary flat bone or secondary osteosarcomas.

CONCLUSIONS

Outcome for both groups of patients was poor due to metastases and failure of local control. Sixteen of the 27 patients with primary osteosarcoma of flat bones died of their tumor; an additional patient died of doxorubicin-related cardiomyopathy and had microscopic disease in the primary site at autopsy. Thirteen of the 18 patients with secondary osteosarcoma died of their second metastatic cancer, 2 additional patients died of doxorubicin-related cardiomyopathy/coccidioidomycosis, and another of acute renal toxicity.

Second malignant neoplasms occuring in survivors of osteosarcoma

BACKGROUND

Second malignant neoplasms have been noted infrequently in survivors of osteosarcoma treated before 1970.

METHODS

For the above reason, the authors surveyed their patients to determine the actuarial incidence and relative risk of second malignancies among patients treated with adjuvant chemotherapy for osteosarcoma.

RESULTS

Between March 1962 and March 1996, 334 patients received chemotherapy for newly diagnosed primary or metastatic osteosarcoma. Of these patients, 47 presented with metastases, 14 had multifocal osteosarcoma, and 273 had localized disease. Nine patients developed second malignant neoplasms 0.45-17.8 years (median, 6.3 years) after receiving definitive surgery and adjuvant chemotherapy for primary osteosarcoma; 2 of these patients had pulmonary metastasectomies before receiving adjuvant chemotherapy. The second neoplasms comprised two cases of malignant fibrous histiocytoma and one case each of melanoma, glioblastoma multiforme, chondrosarcoma, and carcinoma of the breast: stomach, colon, rectum. The overall 10-year cumulative incidence of second malignancies was 2% +/- 1%; by comparison, this rate was 2% +/- 1% for patients with localized osteosarcoma but was 8% +/- 5% (P = 0.15) for those who presented with metastatic disease.

CONCLUSIONS

Since the advent of successful adjuvant chemotherapy, more patients are surviving primary osteosarcoma; therefore, the number of osteosarcoma patients who develop second malignancies can be expected to increase. Recognition of osteosarcoma patients who are members of families with Li-Fraumeni syndrome may lead to earlier intervention for these individuals.

[Effects of CD11/CD18 on adhesion between endothelial cell and PMN and its expression in early stage postburn]

This study was to investigate the expressions of CD11a/CD18 and CD11b/CD18 on burn patient's polymorphonuclear neutrophil (PMN) in early postburn stage and effects of CD11/CD18 mAb on PMN-EC adhesion and endothelial cell (EC) damage induced by PMN. Adhesive rate between PMN and EC, the filtration coefficient (kf) and monolayer volume flux (Jv) were determined after incubating burn patient's PMN with human umbilical vein endothelial cell (HUVEC) for 24 hours. CD11a/CD18 monoclonal antibodies (mAb) and CD11b/CD18 mAb were used to pretreat burn patient's PMNs in order to demonstrate the role of CD11/CD18 in PMN-EC adhesion and EC damage. Expressions of CD11a/CD18 and CD11b/CD18 were determined by flow cytometry 1, 3, 5, 7 d postburn. The results indicated that expressions of CD11a/CD18 and CD11b/CD18 on burn patient's PMNs increased quickly, reaching the peak on day 1 postburn and remained in high level till 7 days postburn. The values of Kf and Jv were increased markedly after burn patient's PMNs was incubated with HUVECs, which were cultured on micropore filter membrane. When burn patient's PMNs were pretreated with CD11a/CD18 mAb and CD11b/CD18 mAb, PMN-HUVEC adhesive rate was inhibited by 70%-80% and the values of Jv and kf were decreased significantly. It suggested that there were increased expressions of CD11a/CD18 and CD11b/CD18 on PMNs after burn injury. Burn patient's PMNs could damage EC and increased EC monolayer permeability (kf, Jv). CD11/CD18 mAb inhibited PMN-EC adhesion and attenuated EC damage induced by PMNs.

Multimodal therapy for children and adolescents with Ewing sarcoma: results of the First National Chilean Trial (1986-1991)

Thirty-seven patients with Ewing sarcoma were treated in the First National Chilean Trial for Ewing's Sarcoma (1986-1991), which comprised the St. Jude Ewing's 78 Study. All patients received cyclophosphamide, doxorubicin, vincristine, and Dactinomycin for a total treatment period of about 10 months, and all prescribed therapy was administered. Local therapy consisted of irradiation (RT) to the primary tumor, complete surgical resection, or a combination of both surgery and RT. Twenty-nine of these patients had localized tumors, 24% had pelvic primary tumors, 21 were males, and 20 were greater than 10 years of age at diagnosis. Twenty-one patients had tumors that were greater than 8 cm in largest diameter. Fourteen of the 29 patients with localized disease remain disease free at 23 to 91 months from diagnosis. Fourteen patients have died of-tumor-related complications and 1 of a secondary malignancy. Relapse was local only in 4, metastatic in 9, and local plus metastatic in 1. Only 1 of the 8 patients with metastatic disease at presentation remains disease free. Toxicity consisted primarily of myelosuppression and mucositis. We conclude that this form of relative intense multimodal therapy for children/adolescents with localized Ewing sarcoma is curative in about half of affected children as in the original St. Jude study, and that it can be safely given in a developing country, provided that careful attention to supportive care and treatment planning is given. Although these results represent improvement in outcome for our patients, more effective therapy is needed for children with Ewing sarcoma, especially those with metastatic disease at presentation.

A phase II trial of high-dose methotrexate in previously untreated children and adolescents with high-risk unresectable or metastatic rhabdomyosarcoma

PURPOSE

The outcome for children with advanced-stage rhabdomyosarcoma remains poor with contemporary treatment regimens. Evaluation of new drugs is important to improve clinical outcome. Because methotrexate has shown promising activity in the treatment of patients with recurrent rhabdomyosarcoma, we conducted a phase II trial in untreated children with advanced-stage disease to evaluate the efficacy and safety of this agent.

PATIENTS AND METHODS

Fifteen patients received 1 to 4 courses of high-dose methotrexate (HDMTX, 12 g/m2). Patients then received standard multiagent chemotherapy (vincristine, dactinomycin, cyclophosphamide, ifosfamide, mesna) with cytokine support and local radiotherapy. Patients who responded to HDMTX received four additional courses of this drug during continuation therapy.

RESULTS

Twelve patients were evaluable for response after 2 or more courses of HDMTX; 4 achieved a partial response (33.3%). After administration of standard chemotherapy and radiation, the estimated 2-year progression-free survival for all patients was 56% (SD 15%). The drug was well-tolerated and the most common side effects included mucositis, transient elevation of transaminases, and neutropenia. The four patients who received additional courses of HDMTX during continuation therapy had limited toxicity which included mucositis, anemia, and thrombocytopenia.

CONCLUSIONS

About one-third of children with previously untreated advanced-stage rhabdomyosarcoma responded to HDMTX. Its different mechanism of action and non-overlapping toxicity with other agents make HDMTX an attractive candidate for incorporation into front-line treatment regimens for rhabdomyosarcoma.

Complications of pelvic exenteration in children who have genitourinary rhabdomyosarcoma

BACKGROUND

Rhabdomyosarcoma is the most frequently encountered soft tissue sarcoma in children younger than 15 years of age.

METHODS

The authors reviewed the early and long-term morbidity rate and clinical outcome of pelvic exenteration for genitourinary rhabdomyosarcoma (GU-RMS) in children. Of 43 patients with this diagnosis who were seen at St Jude Children's Research Hospital between 1963 and 1994, 17 underwent pelvic exenteration. These 13 boys and four girls ranged in age from 6 months to 15 years (median, 3.5 years). Their primary sites included prostate (n = 12), bladder (n = 4), and uterus (n = 1). All patients received multiagent chemotherapy and either preoperative or postoperative radiation therapy. Anterior exenteration was performed in 15 patients and total exenteration in two. The complications were classified as early or late (occurring within or after 30 days from the date of surgery) and as major or minor (depending on the risk of death or physical or functional disability).

RESULTS

Thirteen of the 17 patients (76%) had 49 surgery-related complications. Wound infection (24%), fistula, abscess, and malnourishment (12% each) were the most common early major complications, with hydronephrosis (35%), bowel obstruction (24%), acute pyelonephritis, fistula, lymphedema, and ureter stenosis (12% each) making up the majority of late complications in this category. Relatively frequent minor complications included protracted paralytic ileus and hematuria (18%), cholelithiasis, chronic diarrhea and, peristoma skin irritation (12%). Disease-free survival was associated with the timing of surgery (P = .002). All but one of the 12 patients who underwent surgery within 6 months of diagnosis are alive, compared with only one of five whose surgery was performed after a longer interval. Pelvic exenteration for GU-RMS was associated with a high rate of serious complications in this series of patients treated over 31 years.

CONCLUSION

With recent advances in surgical techniques, as well as improvements in preoperative and postoperative care, this procedure should continue to be applied in cases resistant to conventional therapy.

[Limb salvage and amputation in osteosarcoma: report of 31 cases]

Three different types of operation were performed in 31 osteosarcoma patients, and some cases received chemotherapy. It revealed, wide resection of tumor supplemented with chemotherapy improved the survival and limb salvage rate enormously. Chemotherapy and wide resection were all absolutely essential. The life of prosthesis was long and most patients were satisfied with it. Chemotherapy and limb salvage can enhance the survival and life quality in patients with osteosarcoma.

[Cell culture of human lamina cribrosa in vitro]

OBJECTIVE

To investigate the physiology and pathology of the biosynthesis of extracellular matrix (ECM) by lamina cribrosa cells (LCC) and to establish a model of cultured LCC.

METHODS

The LCC of 10 human dead fetal eyes were cultured with enzyme digestion procedures in vitro. The cultured cells were identified by immunohistochemistry assays and electron microscopy.

RESULTS

The cultured cells were flat, polygonal in shape, and their cytoplasm contained abundant perinuclear granules. The nuclei were relatively transparent and nucleoli were clear, there were basement membrane-like material and ECM surrounding the cell membrane. The immunofluorescent staining was positive for collagen type I, III, IV, fibronectin and laminin, negative for glial fibrillar acid protein and factor-VIII. The characteristics mentioned above were coincident with the morphology of LCC. This cell line has been cultured to its fourth generation.

CONCLUSION

We have successfully cultured a cell line of LCC, and it may be utilized in the study of pathogenesis of glaucoma.

[Fabrication and use of two kinds of overdenture attachments]

The authors introduced the fabrication of stud attachment and bar attachment used to increase the stability and retention of overdenture. During two years' periods, the results of the clinical practice indicated: the retention of overdenture was increased and patients' masticator function was improved when attachments were used, and then the fabrications of two kinds of attachments were simple and value of attachments is cheap. The technique was popularized and used easily.