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Biomedical subjects

B Kornhuber

Publications and source records attributed to B Kornhuber.

At least 19 recordsLinked to original sources
PubMed2006

Pharmacology of intracellular cytosine-arabinoside-5'-triphosphate in malignant cells of pediatric patients with initial or relapsed leukemia and in normal lymphocytes.

PURPOSE: The prodrug cytosinearabinoside (ara-C) is widely used in the treatment of acute leukemias. The active drug is the intracellular metabolite cytosine-arabinoside-5'-triphosphate (ara-CTP). The purpose of the present study was to investigate the relation between sensitivity and pharmacokinetic parameters Cmax, t1/2 and AUC of ara-CTP. The obtained results were compared to previous studies. EXPERIMENTAL DESIGN: Cmax, t1/2 and AUC of ara-CTP were assessed in leukemic cells of 17 pediatric patients with acute lymphoblastic leukemia (ALL) and in 6 lymphoblastic cell lines and compared with normal lymphocytes of 9 healthy donors by high pressure liquid chromatography (HPLC). The sensitivity of the cells against ara-C was determined by the MTT assay. RESULTS: The intracellular accumulation of ara-CTP was significantly lower in normal lymphocytes (Cmax 47.7-60.9 pmol/10(6) cells) compared to leukemic cell lines (Cmax 11-1128 pmol/10(6) cells) and leukemic cells of our patients (Cmax 85.9-631 pmol/10(6) cells). Similar results were found for the AUC. There was no significant difference between initial and relapsed leukemias in our small cohort. A correlation between sensitivity in terms of IC50 values and the intracellular ara-CTP accumulation was observed in cell lines, but not in leukemic cells and normal lymphocytes from healthy donors. CONCLUSIONS: Pharmacokinetic parameters varied tremendously in leukemic cells in contrast to normal lymphocytes without a difference in sensitivity. It is worthwhile to compare literature data to assess an optimal dosage of ara-C in pediatric patients.

Adolescent↗
PubMed2001

Localized Ewing tumor of bone: final results of the cooperative Ewing's Sarcoma Study CESS 86.

PURPOSE: Cooperative Ewing's Sarcoma Study (CESS) 86 aimed at improving event-free survival (EFS) in patients with high-risk localized Ewing tumor of bone. PATIENTS AND METHODS: We analyzed 301 patients recruited from January 1986 to July 1991 (60% male; median age 15 years). Tumors of volume >100 mL and/or at central-axis sites qualified patients for "high risk" (HR, n = 241), and small extremity lesions for "standard risk" (SR, n = 52). Standard-risk patients received 12 courses of vincristine, cyclophosphamide, and doxorubicin alternating with actinomycin D (VACA); HR patients received ifosfamide instead of cyclophosphamide (VAIA). Tumor sites were pelvis (27%), other central axis (28%), femur (19%), or other extremity (26%). The initial tumor volume was <100 mL in 33% of cases and > or =100 mL in 67%. Local therapy was surgery (23%), surgery plus radiotherapy (49%), or radiotherapy alone (28%). Event-free survival rates were estimated by Kaplan-Meier analyses, comparisons were done by log-rank test, and risk factors were analyzed by Cox models. RESULTS: On May 1, 1999 (median time under study, 133 months), the 10-year EFS was 0.52. Event-free survival did not differ between SR-VACA (0.52) and HR-VAIA (0.51, P =.92). Tumor volume of >200 mL (EFS, 0.36 v 0.63 for smaller tumors; P =.0001) and poor histologic response (EFS, 0.38 v 0.64 for good responders; P =.0007) had negative impacts on EFS. In multivariate analyses, small tumor volumes of <200 mL, good histologic response, and VAIA chemotherapy augured for fair outcome. Six of 301 patients (2%) died under treatment, and four patients (1.3%) developed second malignancies. CONCLUSION: Fifty-two percent of CESS 86 patients survived after risk-adapted therapy. High-risk patients seem to have benefited from intensified treatment that incorporated ifosfamide.

Adolescent↗
PubMed2000

Improved outcome in childhood acute lymphoblastic leukemia despite reduced use of anthracyclines and cranial radiotherapy: results of trial ALL-BFM 90. German-Austrian-Swiss ALL-BFM Study Group.

Trial ALL-BFM 90 was designed to improve outcome in patients with childhood acute lymphoblastic leukemia (ALL) by using a reduced treatment regimen. Patients were stratified into a standard-risk group (SRG), a medium-risk group (MRG), both defined by adequate early treatment response; and a high-risk group (HRG), defined by inadequate response to the cytoreductive prednisone prephase, induction failure, or Philadelphia-chromosome-positive ALL. Four treatment modifications were evaluated: dose intensification in induction by a more rapid drug sequence; administration of L-asparaginase during consolidation therapy in the MRG (randomized); enforced consolidation by rotational elements in the HRG; and reduction in the dose of anthracyclines and use of only 12-Gy preventive cranial radiotherapy in the MRG and HRG, with the aim of avoiding toxicity. Among all 2178 patients (</= 18 years of age), the 6-year event-free survival (EFS) rate (+/- SE) was 78% +/- 1%, with a median observation time of 4.8 years. EFS was 85% +/- 2% in the SRG (n = 636) and 82% +/- 1% in the MRG (n = 1299). L-asparaginase did not improve outcome in the MRG: the event-free interval was 83% +/- 2% with L-asparaginase (n = 528) and 81% +/- 2% without it (n = 557). Because there were more systemic relapses in the HRG (n = 243), EFS was 34% +/- 3%, an outcome inferior to that in the HRG in a previous trial, ALL-BFM 86, in which EFS was 47% +/- 5% (P =.04). The rates of isolated central nervous system relapse in the MRG and HRG were 0.8% and 1.6%, respectively; thus, the 12-Gy preventive cranial radiotherapy regimen apparently provided sufficient central nervous system prophylaxis. The overall improvement over the results in ALL-BFM 86 (6-year EFS, 72%; P =. 001) was based on fewer recurrences among patients in the MRG with B-cell-precursor ALL, indicating an advantage of more condensed induction therapy. In multivariate analysis, inadequate in vivo response emerged as the strongest adverse prognostic variable.

Adolescent↗
PubMed1999

Preliminary experiences with triple therapy including nelfinavir and two reverse transcriptase inhibitors in previously untreated HIV-infected children.

OBJECTIVE: In an intent-to-treat study increase in CD4 cell count, reduction of viral load, clinical benefit and adverse reactions were examined in HIV-infected previously treatment-naive children taking triple therapy. METHODS: sixteen HIV-infected children in category A or B on antiretroviral triple therapy were followed-up for a period of 12 months. In group I eight patients received zidovudine, lamivudine and nelfinavir; in group II eight patients received stavudine, didanosine and nelfinavir. Viral load and CD4 cell count were measured every 4-8 weeks. Plasma nelfinavir levels were assessed once in all patients at baseline and monitored in patients with increasing viral load. RESULTS: No significant differences were observed between treatment groups in terms of CD4 cell counts and viral load. A median viral load reduction of 2.8 log10 (range, 1.4-4.2 log10) was achieved over a period of 12 months in both groups. Viral load < 500 copies/ml was found in 69% of patients and viral load < 50 copies/ml in 44% of patients after 12 months. Median CD4 cell count increased from 656 x 10(6) to 850 x 10(6) cells/l after 3 months and was maintained at 813 x 10(6) cells/l after 12 months of treatment. Main side-effects were diarrhoea, rash and hyperlipidaemia. Except for application problems, both regimens were well tolerated. Appropriate formula and individual counselling must be performed during the first weeks of treatment in order to achieve good compliance in paediatric patients. CONCLUSION: Triple antiretroviral therapy shows a stronger and more sustained reduction of viral load in HIV-infected children compared with studies combining two nucleoside analogues.

Anti-HIV Agents↗
PubMed1999

[Prevention of joint damage in hemophilic children with early prophylaxis].

Radiological and orthopaedic outcome in severe and moderate haemophilia A and B patients undergoing long-term prophylactic treatment were prospectively investigated focusing on the age of onset of prophylaxis and the number of joint bleedings prior to treatment. We report on 21 patients with severe and moderate haemophilia A and B receiving prophylactic treatment of between 3.1 and 16.1 years duration. Three patient groups were evaluated according to the age at onset of prophylaxis. In group I (n = 8) prophylactic treatment was initiated in the first 2 years of life. Patients of group II (n = 6) received prophylaxis at the age of 3-6 years. Late-onset or secondary prophylactic treatment was started at the age of 6 years and above in 7 patients (group III). All patients received virus-inactivated F VIII or F IX concentrates at dosages of 30-40 IU, in some cases up to 50 IU/kg body weight i.v. three times per week for those with haemophilia A and twice per week for those with haemophilia B. Elbow, knee and ankle joints were investigated at 3-4 yearly intervals according to the radiological and orthopaedic scores recommended by the World Federation of Haemophilia (WFH). The total number of joint bleedings before and after start of prophylaxis were recorded in all patients. In group 17 out of 8 patients had unaffected joints with constant radiological and orthopaedic scores of zero or 1, after a median of 11.25 years of prophylactic treatment. One patient in this group demonstrated mild radiological alterations (score 4). Patients of group II showed neither radiological nor orthopaedic alterations at study entry. Worsening joint scores could be detected despite ongoing prophylaxis after the 3-year interval (median orthopaedic score 4, median radiological score 8). Treatment group III already showed considerable joint damage at study entry with a median radiological score of 11 (0-33) and a median orthopaedic score of 4 (0-11). Despite prophylactic treatment both, orthopaedic (median 8, range 2-12) and radiological scores (median 19.5, range 2-47) deteriorated after 3 years. Prior to onset of prophylaxis no or only one joint bleeding occurred in treatment group I. In group II, a median of 6 joint bleeds (range 1-8) were reported before prophylaxis was started. Patients of group III usually experienced a median of more than 10 joint haemorrhages (range 6-10 or more). Under prophylactic treatment the number of joint bleedings decreased significantly in groups II and III. However, radiological and orthopaedic scores increased as a sign of progressing osteoarthropathic alterations in patients reporting more than 6 joint haemorrhages before onset of prophylaxis whereas no joint alterations could be assessed in patients with no or only one joint bleeding episode prior to prophylaxis. Even a small number of joint bleedings seems to cause irreversible osteoarthropathic alterations leading to haemophilic arthropathy. Once apparent, further progression of joint damage could not be arrested despite of prophylactic treatment (group II and III). In order to prevent haemophilic arthropathy, effective prophylaxis should be started before or at least after the first joint bleeding in severe haemophilia A and B.

Adolescent↗
PubMed1999

Functional results after partial pelvic resection in Ewing's sarcoma of the ilium.

Ewing's sarcoma of the pelvis has an unfavourable prognosis. The clinical and functional results of 7 patients who had a Ewing's sarcoma of the pelvis stage IIB were reviewed. All patients received multiple-agent chemotherapy pre- and postoperatively (modified T6 and T2 protocol according to Rosen) and underwent local resection of the pelvic tumour. According to Enneking, five patients had a type IA resection, one patient type I and another type IIA. One patient received a course of radiation therapy postoperatively (50 Gy). Six of seven patients showed a good regression of the tumour after preoperative chemotherapy. One patient who had a giant-cell Ewing's sarcoma died of local recurrence and lung metastases 29 months postoperatively. The remaining six patients were monitored radiographically and clinically according to Enneking's functional evaluation score after a follow-up period of 136 months (range 40-199 months). All were free of disease and had neither local recurrence nor metastases. In five patients the functional results were rated as "good" or "excellent". The good results depend mainly on the reconstruction of the pelvic girdle and its mechanical stability.

Adolescent↗
PubMed1999

wt1 gene expression in childhood leukemias.

The expression of the Wilms' tumor gene (wt1) was detected in various tissues during embryonic development. Mutations in the wt1 gene probably play an important role in certain tumors, e.g. the Wilms' tumor. Furthermore the expression of wt1 gene was found in some human leukemias. In the present study we investigated the expression of wt1 gene in several types of childhood leukemia by reverse transcriptase-polymerase chain reaction. Bone marrow or peripheral blood of 61 pediatric patients (48 at initial diagnosis, 13 at first or second relapse) were analyzed. wt1 gene expression was detected in 35/48 patients (73%) with newly diagnosed leukemias and in 12/13 cases (92%) who had suffered from relapse. The expression levels were higher for AML than for ALL. The frequency of wt1 expression in different subtypes of acute leukemia was compared with results found in adult patients. Our results show that the frequency of wt1 gene expression in acute childhood leukemias is similar to previous data reported for adults.

Acute Disease↗
PubMed1999

Bovine seminal ribonuclease selectively kills human multidrug-resistant neuroblastoma cells via induction of apoptosis.

Bovine seminal ribonuclease (BS-RNase) is a homologue of RNase A with specific antitumor activity. The cytotoxic action of this agent was examined in human neuroblastoma (NB) cell lines (SK-N-SH and UKF-NB-4) possessing the multidrug resistance (MDR) phenotype and NB cell lines (IMR-32, UKF-NB-1, UKF-NB-2 and UKF-NB-3) without MDR. Although MDR cells expressed large amounts of mdr-1 mRNA, contained functional P-glycoprotein and had 20- to 105-fold lower sensitivities to doxorubicin and vincristine than cells with non-MDR phenotypes, BS-RNase was equally toxic to all NB cells at concentrations employed (0.2 to 100 microg/ml). BS-RNase showed high selectivity for NB cells and was non-toxic to normal fibroblasts and epithelial cells. Ultrastructural investigation and annexin V assay showed that BS-RNase is a powerful inductor of apoptosis. The antitumoral effects of BS-RNase were also demonstrated in vivo using established subcutaneous xenografts in athymic (nude) mice of the MDR-1-bearing UKF-NB-4 cell line. Intratumoral injections (12.5 mg/kg) of BS-RNase over four weeks resulted in complete tumor regression and absence of tumor regrowth over a two-week observation period after cessation of treatment. The results show that BS-RNase selectively kills NB cells by inducing apoptosis and that this agent is active against mdr-1 expressing cells both in vitro and in vivo. BS-RNase fulfills important criteria for a candidate antitumor agent in NB patients with advanced disease.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Selective cytotoxic activity of a novel ribonucleoside diphosphate reductase inhibitor MDL-101,731 against thyroid cancer in vitro.

The dramatically increased number of new cases of disseminated children thyroid cancer in Belarus after the Chernobyl accident requires development of novel strategies to treat this disease. In addition to conventional therapy using radioiodine, chemotherapy with new effective drugs can be an alternative kind of treatment. We tested the antitumor activity of (E)-2'-fluoromethylene-2'-deoxycytidine (MDL-101,731), a ribonucleoside diphosphate reductase inhibitor against three thyroid carcinoma cell lines established from anaplastic (8505C), papillary (B-CPAP) and poorly differentiated papillary (BHT-101) cancer. MDL-101,371 decreased both cell growth and DNA synthesis of tumor cells at concentrations lower than 100 nM, while the concentrations higher than 5000 nM showed only moderate effects on growth of normal human fibroblasts. The effects of MDL-101, 371 on tumor cells were associated with induction of apoptosis, as demonstrated by DNA fragmentation assay. Flow cytometric analysis of the expression of apoptosis-related genes revealed the increased levels of Fas-antigen, whereas the levels of Bcl-2 were not significantly influenced in thyroid cancer cells treated with MDL-101,731. These results demonstrated that MDL-101,731 is a potent antitumor agent against cultured thyroid cancer cells due to its ability to induce apoptosis in association with increased Fas expression.

Antineoplastic Agents↗
PubMed1998

Persistent human cytomegalovirus infection induces drug resistance and alteration of programmed cell death in human neuroblastoma cells.

Infection with human cytomegalovirus (HCMV) is a common and generally asymptomatic affection in childhood. Its role in neuroblastoma (NB) patients has not yet been elucidated. As evidence grows that HCMV interacts with apoptotic signaling due to the interaction of HCMV gene products with cellular proteins of apoptotic pathways, we used human NB cell line UKF-NB-2 persistently infected with HCMV strain AD169 to study the effects of long-term HCMV infection on programmed cell death of neuroectodermal tumor cells. The cells designated UKF-NB-2AD169 continued to produce infectious virus in successive subcultures over a period of more than 1 year. Up to 20% of cells expressed viral genes or produced infectious virus after initiation of infection. UKF-NB-2AD169 cells were significantly less sensitive to the cytotoxic agents cisplatinum and etoposide than parental (noninfected) UKF-NB-2 cells. These effects were associated with decreased ability of UKF-NB-2AD169 cells to undergo apoptosis and continuous viral replication. UKF-NB-2AD169 cells showed increased levels of antiapoptosis Bcl-2 protein (up to 12-fold), whereas expression of p53 and c-myc was not changed. Treatment of UKF-NB-2AD169 cells with ganciclovir, abolishing virus production, reestablished sensitivity to chemotherapy, lowered Bcl-2 expression, and facilitated inducibility of apoptosis to the level of the parental cell line. The results demonstrate that persistent HCMV infection confers resistance to cytotoxic agents on neuroectodermal tumor cells and protects from apoptosis, probably due to increased levels of Bcl-2 protein. Hence, it is conceivable that HCMV infection before or during tumorigenesis may contribute in some NB patients to failure of therapy.

Antigens, Viral↗
PubMed1998

Radiological and orthopedic score in pediatric hemophilic patients with early and late prophylaxis.

In order to evaluate joint alteration, 17 patients with hemophilia A and B were investigated over a period of 4 years (1993-1997). Patients were subdivided into two groups, according to therapy regimens. In group 1 (n=10) prophylactic treatment was initiated until the third year of life. In group 2 (n=7) patients received prophylactic treatment at the age of 5 years and above. To assess alterations in knee, elbow, and ankle joints, the radiological score and the physical examination score of the Orthopedic Advisory Committee of the World Federation of Hemophilia were used. The sum of the scores of these six joints was defined as the patient-dependent score. Patients of group 1 (median age at the end of observation: 10 years) reached a median radiological score of 1.0 (range: 0-13) and an orthopedic score of 0 (range: 0-4), whereas patients of group 2 (median age: 14 years) had a radiological score of 20 (range: 2-47) and an orthopedic score of 8 (range: 0-12), which shows a significant difference (p <0.01). In both treatment groups a manifestation or progression of arthropathic alteration was seen in those children who had repeated joint bleeding (>5) prior to the onset of prophylactic treatment (r=0.90, p>0.01). Altogether, two of 60 joints in group 1 and 12 of 42 joints in group 2 had a radiological score > or = 4. Elbow joints were more often affected than knee and ankle joints. In conclusion, the number of joint bleedings before prophylactic treatment was started influenced the progression of arthropathy even in patients with early onset of prophylaxis. The aim of treatment in severe hemophilia should be early prophylaxis before repeated joint bleeding occurs in order to prevent osteoarthropathic alteration.

Adolescent↗
PubMed1998

When should prophylactic treatment in patients with haemophilia A and B start?--The German experience.

Radiological and orthopaedic outcome in severe and moderate haemophilia A and B patients undergoing long-term prophylactic treatment were prospectively investigated focusing on the age of onset of prophylaxis and the number of joint bleedings prior to treatment. We report on 21 patients with severe and moderate haemophilia A and B receiving prophylactic treatment of between 3.1 and 16.1 years' duration. Three patient groups were evaluated according to the age at onset of prophylaxis. In group I prophylactic treatment was initiated in the first 2 years of life. Patients in group II received prophylaxis at the age of 3-6 years. Late-onset or secondary prophylactic treatment was started at the age of 6 years and above in seven patients (group III). All patients received virus-inactivated F VIII or F IX concentrates at dosages of 30-50 IU/kg body weight i.v. three times per week for those with haemophilia A and twice per week for those with haemophilia B. Elbow, knee and ankle joints were investigated at 3-4-yearly intervals according to the radiological and orthopaedic scores recommended by the World Federation of Haemophilia. The total number of joint bleedings before and after start of prophylaxis were recorded in all patients. In group I 7/8 patients had unaffected joints with constant radiological and orthopaedic scores of zero or 1, after a median of 11.25 years of prophylactic treatment. One patient in this group demonstrated mild radiological alterations (score 4). Patients in group II showed neither radiological nor orthopaedic alterations at study entry. Surprisingly, worsening joint scores could be detected despite ongoing prophylaxis after the 3-year interval (median orthopaedic score 4, median radiological score 8). Treatment group III already showed considerable joint damage at study entry with a median radiological score of 11 (0-33) and a median orthopaedic score of 4 (0-11). Despite prophylactic treatment, both radiological (median 19.5, range 2-47) and orthopaedic scores (median 8, range 2-12) deteriorated after 3 years. Prior to onset of prophylaxis, no or only one joint bleeding occurred in treatment group I. In group II, a median of six joint bleeds (range 1-8) was reported before prophylaxis was started. Patients in group III usually experienced a median of more than 10 joint haemorrhages (range 6-10 or more). Under prophylactic treatment the number of joint bleedings decreased significantly in groups II and III. However, radiological and orthopaedic scores increased as a sign of progressing osteoarthropathic alterations in patients reporting more than five joint haemorrhages onset of prophylaxis whereas no joint alterations could be assessed in patients with no or only one joint bleeding episode prior to prophylaxis. Even a small number of joint bleedings seems to cause irreversible osteoarthropathic alterations leading to haemophilic arthropathy. Once apparent, further progression of joint damage could not be arrested despite of prophylactic treatment (groups II and III). In order to prevent haemophilic arthropathy, effective prophylaxis should be started before or at least after the first joint bleeding in severe haemophilia A and B.

Adolescent↗
PubMed1998

Azidothymidine resistance of H9 human T-cell lymphoma cells is associated with decreased sensitivity to antitumor agents and inhibition of apoptosis.

Biology of HIV-1 associated neoplasias is modulated by viral and host factors. In addition the development of tumors and their response to therapy may be further influenced by long-term treatment of HIV-1 patients with nucleoside analogs such as AZT (3'-azido-3'deoxythymidine), ddI (2',3'-dideoxyinosine), ddC (2',3'-dideoxycytidine), d4T (2',3'-didehydro-2'3'-dideoxythymidine), and 3TC [(-)-beta-L-2',3'-dideoxy-3'-thiacytidine] alone or in combination. As these compounds can trigger mechanisms involved in chemoresistance, we tested whether prolonged in vitro treatment of H9 cells (T-cell lymphoma) with AZT alters sensitivity of lymphoma cells to antitumor agents used for AIDS-associated malignancies. H9 cells grown for more than two years in medium containing 250 microM AZT developed resistance to the toxic effects of AZT while retaining sensitivity for other nucleoside analogs including ddC or cytosine arabinoside (ARA-C). These cells designated H9rAZT250 were 2 to 10-fold less sensitive to the toxic effects of antitumor agents, including cisplatin (CDDP), vincristine (VCR), doxorubicin (DOX) and etoposide (VP-16), when compared with parental H9 cells. The resistance of H9rAZT250 cells to antitumor agents was associated with inhibition of apoptosis as demonstrated by ultrastructural investigations and DNA-fragmentation assay (ELISA). The expression of the antiapoptotic gene bcl-2 was increased in H9rAZT250 cells while expression of other genes involved in the regulation of apoptosis such as c-myc, p53 and Fas was not changed. These results demonstrate that prolonged in vitro treatment of H9 lymphoma cells with AZT results in the development of resistance to antitumor agents in association with inhibition of apoptosis and increased expression of bcl-2. Therefore AZT long-term treatment of some HIV-1 patients with malignancies may have affected behavior of tumor cells including response to therapy.

Anti-HIV Agents↗
PubMed1997

Minimal residual disease in leukemia in children.

Many chromosomal translocations involved in leukemia have been defined at the molecular level in recent years. In addition to advancing the understanding of pathological mechanisms underlying the transformation process, the cloning and sequencing of the genes altered by the translocations have provided new tools for diagnosis and monitoring of patients. In particular, the polymerase chain reaction (PCR) method yields sensitive and accurate diagnostic and prognostic information. Minimal residual disease (MRD) is not clearly defined. In ALL we define MRD as fewer than 5% blast cells in the bone marrow by conventional cytology and proof of leukemic cells with more sensitive methods. The techniques for detecting MRD are imaging for detection of single leukemic cells in the blood, bone marrow, or other tissues by means of immunocytology or PCR/RT-PCR. Highly sensitive PCR, immunocytology, FACS analysis, or conventional cytology are important tools to use in the process of deciding on appropriate therapy. Detection limits at present are 10(-2) for cytology and FISH, up to 10(-4) for immunological procedures, and 10(-5) to 10(-6) for PCR. But multiple methods also imply the possibility of mistakes (e.g., PCR). The question must be raised what method should be decisive in assessing MRD for evaluating autologous peripheral blood stem cells (PBSC) or autologous bone marrow transplants? Prospective studies will have to answer the question whether MRD should be treated or not and whether purging of bone marrow or PBSC is useful or damaging. When applied, should a positive or a negative immunopurging or a chemotherapeutic purging be used? MRD refers to the organism of the patient as well as to the peripheral blood stem cells and autologous bone marrow that had been taken before myeloablative therapy and kept for retransfusion.

Bone Marrow Transplantation↗
PubMed1997

Antiviral effects of 6-diazo-5-oxo-L-norleucin on replication of herpes simplex virus type 1.

An L-glutamine antagonist, 6-diazo-5-oxo-L-norleucin (L-DON), inhibits replication of vesicular stomatitis virus, poliovirus and paramyxoviruses in cultured cells. We tested the antiviral activity of L-DON against different strains of herpes simplex virus type 1 (HSV-1) in Vero cells. In the presence of a physiological plasma concentration of L-glutamine (0.5mM) L-Don inhibited 50% production of virus plaques at concentrations ranging from 7.9 to 16 microM. At concentrations of 40 microM L-Don inhibited infectious virus yield by 99%. The antiviral activity of L-DON decreased with increasing L-glutamine concentrations. A concentration of 5000 microM of L-Don had no significant effects on the viability of Vero cells. Transmission electron microscopical investigations showed that L-DON prevented mainly envelopment of viral nucleocapsids in the cytoplasm. The immunoprecipitation experiments demonstrated selective inhibition of synthesis of HSV-1 glycoproteins in L-DON treated cells. The results showed that L-DON inhibits HSV-1 replication at a late stage in the virus replication cycle, probably the cytoplasmic maturation of virions and subsequent virion egress from the cells.

Animals↗
PubMed1997

Fluconazole versus nystatin in the prevention of candida infections in children and adolescents undergoing remission induction or consolidation chemotherapy for cancer.

An open, prospective, randomized pilot study was performed to assess the efficacy and safety of oral fluconazole 3 mg/kg once daily compared with oral nystatin 50,000 units/kg/day in four divided doses in preventing candida infections in 50 children undergoing remission induction or consolidation therapy for cancer. In 21 of 25 fluconazole-treated and 20 of 25 nystatin-treated patients the overall outcome of prophylaxis was clearly successful. Mild and transient oropharyngeal candidosis was observed in two and three patients in the fluconazole and nystatin groups respectively. One patient randomized to fluconazole and two patients randomized to nystatin required empirical treatment with amphotericin B and one patient assigned to fluconazole developed tissue-proven candida colitis. Initially non-colonized patients remained yeast-free throughout treatment with no differences between the two study arms. Initially colonized patients stayed colonized throughout treatment although at the end of the study, more patients randomized to nystatin were still harbouring yeasts (P = 0.05). Almost exclusively, Candida albicans (95%) was isolated. A change in species was observed in one patient in each arm of the study. Candida krusei or Candida glabrata were not encountered. Transient elevations of hepatic transaminases were more common in the fluconazole group, although not statistically significant (28% vs 12%, P = 0.15). Reversible grade I gastrointestinal and skin symptoms were observed in four patients randomized to fluconazole (16 vs 0%, P < 0.05). Fluconazole was as safe and effective as nystatin in controlling yeast colonization and in preventing superficial and invasive candida infections and the empirical use of amphotericin B in children and adolescents undergoing intensive chemotherapy for cancer.

Adolescent↗