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Biomedical subjects

X Luo

Publications and source records attributed to X Luo.

296 records · Page 17Linked to original sources
PubMedDate not supplied

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.

Adolescent↗
PubMedDate not supplied

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.

Adolescent↗
PubMedDate not supplied

Late effects of treatment for germ cell tumors during childhood and adolescence.

PURPOSE: To evaluate the long-term sequelae of treatment for malignant germ cell tumors (GCT) during childhood and adolescence. PATIENTS AND METHODS: Of 128 patients treated for GCT at St. Jude Children's Research Hospital between 1962 and 1988, 73 are long-term survivors (continuously disease-free for > or =5 years after diagnosis), with a median follow-up of 11.3 years). Survivors' ages at diagnosis ranged from birth to 18.3 years (median, 9.2 years); 64% (47 patients) were female. Initial surgical resection was followed by observation for stage I germinomas (n = 2), testicular tumors (n = 13), and selected cases of ovarian or sacrococcygeal tumors (n = 2), and by radiation therapy (RT) for patients with stage II to III germinoma (n = 8). The remaining 48 patients received postoperative chemotherapy (vincristine, dactinomycin, and cyclophosphamide [VAC] +/- doxorubicin, 1962 to 1978; VAC and/or cisplatin, vinblastine, and bleomycin [PVB], 1979 to 1988). RT was added to the chemotherapy for 21 patients. Late complications involving various organ systems and their relationship to treatment were evaluated. RESULTS: More than two-thirds of long-term survivors (n = 50) had at least 1 complication, and half (n = 38) had > 1 organ system affected. The systems most often involved included the musculoskeletal (41% of survivors), endocrine (42%), cardiovascular (16% excluding those who had only abnormal chest radiograph), gastrointestinal (25%), genitourinary tract (23%), pulmonary (19%), and neurologic (16%) systems. High-frequency hearing loss occurred in 58% (11 of 19) of patients treated with cisplatin. Musculoskeletal, gastrointestinal, and urinary tract abnormalities were most frequent in patients whose treatment included RT. CONCLUSIONS: A high frequency of late effects after treatment for pediatric GCT, particularly in patients who received RT, was demonstrated. Treatment sequelae could be anticipated from the intensity and type of therapeutic modalities. Treatment-directed screening evaluations may improve quality of life in long-term survivors of pediatric GCT through timely identification of sequelae that can be prevented or ameliorated.

Adolescent↗
PubMedDate not supplied

Co-localization of histamine and dopamine-beta-hydroxylase in sympathetic ganglion and release of histamine from cardiac sympathetic terminals of guinea-pig.

1. The aim of this study was to investigate the co-localization of histamine and dopamine-beta-hydroxylase in the superior cervical ganglion of guinea-pig and release of histamine from cardiac sympathetic terminals in guinea-pig isolated atrium. 2. Histidine decarboxylase (a histamine-synthesizing enzyme) mRNA signals were detected in the neurones of superior cervical ganglion of guinea-pig by in situ hybridization. The results of double-labelled immunofluorescence further confirmed the co-localization of histamine and dopamine-beta-hydroxylase in the large principle neurons and small intensely fluorescent cells in the superior cervical ganglion. The immunoreactivities of both histamine and dopamine-beta-hydroxylase were significantly attenuated after 6-hydroxydopamine-induced lesion of sympathetic nerves. 3. The refractory electrical field stimulation caused the release of histamine from cardiac sympathetic terminals of guinea-pig isolated atria (112.14 +/- 40.34 ng x ml(-1)), which was significantly attenuated to 35 +/- 15.57 ng x ml(-1) by reserpine pretreatment. Following administering compound 48/80, a mast cell degranulator, electrical field stimulation induced a dramatic increase of endogenous histamine release from isolated atria (303.57 +/-72.93 ng x ml(-1)). When compound 48/80 was added to the reserpine-treated atria, the release of histamine induced by field stimulation was decreased to 207.14 +/- 76.39 ng x ml(-1). 4 These results provide novel evidence that histamine co-exists with noradrenaline in sympathetic nerves and might act as a neurotransmitter to modulate sympathetic neurotransmission.

Animals↗
PubMedDate not supplied

A cell-specific nuclear receptor plays essential roles in adrenal and gonadal development.

Recent analyses of the cytochrome P450 steroid hydroxylases have established a key role for an orphan nuclear receptor, designated steroidogenic factor 1 (SF-1), in their coordinate, cell-selective expression. SF-1 was proposed to regulate the steroid hydroxylases by interacting with shared promoter elements in their 5'-flanking regions. During mouse embryonic development, SF-1 was expressed from the earliest stages of organogenesis of the steroidogenic tissues, suggesting a key role in steroidogenic cell differentiation. Finally, disruption of the gene encoding SF-1 revealed its essential function in the development of the adrenal glands and gonads and in pituitary gonadotrope function. These studies suggest that SF-1 acts at multiple levels of the reproductive axis to maintain reproductive competence.

Adrenal Glands↗
PubMedDate not supplied

Analysis of multivariables during porcine liver digestion to improve hepatocyte yield and viability for use in bioartificial liver support systems.

In order to achieve optimal BALSS function, preparation of porcine hepatocytes with high yield, viability, and P450 activity is known to be important. To date hepatocyte yields have varied from 0.58 x 10(10) to 3.45 x 10(10) and viabilities from 75% to 95% within and between laboratories, even when using the same digestion methods and procedures, indicating that hepatocyte isolation during porcine liver digestion is not fully optimized. The aim of this work was to identify the critical parameters affecting cell recovery during porcine liver harvesting by investigating 21 variables involved in the process, including pig body and liver weight, different digestion times of perfusates, pH, a range of concentrations of sodium and chloride in EDTA, and collagenase perfusates. Univariate and multivariate analysis of a retrospective study (n = 23) revealed that low perfusate pH during the process of digestion had a positive effect on hepatocyte yield (p < 0.05), while high (relative) concentrations of sodium and chloride in the perfusates had significant negative effects on hepatocyte viability (both p < 0.05). Sodium and chloride had narrow optimal ranges for achieving a >90% viability. These findings were then tested in a prospective study (n = 10) and further verified. High hepatocyte viabilities (91.8+/-1.6% p = 0.036) and yields (2.56+/-0.48 x 10(10)) were achieved consistently, and P450IA1 activity was increased after sodium and chloride concentrations and pH in the perfusates were controlled. The physiological mechanism by which sodium and chloride affects hepatocyte viability during porcine liver digestion is discussed.

Animals↗
PubMedDate not supplied

Study on initiation of human lung carcinogenesis.

Cigarette smoking condensate and diethylnitrosamine can initiate human lung carcinogenesis as they are able to induce precancerous lesions of bronchioles and the transforming ability of human fetal lung (HFL) DNA. The induction of precancerous lesions in HFL and the acquirement of the transforming ability of HFL DNA by short-term exposure to carcinogens can be combined to yield an ideal model for the initiation of human lung carcinogenesis.

Animals↗