Gilteritinib in combination with venetoclax, low-dose cytarabine and actinomycin D for relapsed or refractory FLT3-mutated acute myeloid leukaemia

We have conducted a retrospective, single-centre analysis of 20 patients with relapsed or refractory FLT3-mutated acute myeloid leukaemia (FLT3m AML) who received a salvage quadruplet regimen consisting of gilteritinib, venetoclax, low-dose cytarabine and actinomycin D (G-ACTIVE). G-ACTIVE resulted in a 95% (19/20) overall response rate and 75% (15/20) complete remission and complete remission with an incomplete platelet recovery (CR + CRp) rate. Out of 13 transplant-eligible patients, 11 (86%) proceeded to an allogeneic stem cell transplantation. The median overall survival and relapse-free survival after G-ACTIVE were 32 and 12.9 months respectively. The Day 60 mortality rate was 15%.

Deficiency of Acetyltransferase nat10 in Zebrafish Causes Developmental Defects in the Visual Function

Purpose

N4-acetylcytidine (ac4C) is a post-transcriptional RNA modification catalyzed by N-acetyltransferase 10 (NAT10), a critical factor known to influence mRNA stability. However, the role of ac4C in visual development remains unexplored.

Methods

Analysis of public datasets and immunohistochemical staining were conducted to assess the expression pattern of nat10 in zebrafish. We used CRISPR/Cas9 and RNAi technologies to knockout (KO) and knockdown (KD) nat10, the zebrafish ortholog of human NAT10, and evaluated its effects on early development. To assess the impact of nat10 knockdown on visual function, we performed comprehensive histological evaluations and behavioral analyses. Transcriptome profiling and real-time (RT)-PCR were utilized to detect alterations in gene expression resulting from the nat10 knockdown. Dot-blot and RNA immunoprecipitation (RIP)-PCR analyses were conducted to verify changes in ac4C levels in both total RNA and opsin mRNA specifically. Additionally, we used the actinomycin D assay to examine the stability of opsin mRNA following the nat10 KD.

Results

Our study found that the zebrafish NAT10 protein shares similar structural properties with its human counterpart. We observed that the nat10 gene was prominently expressed in the visual system during early zebrafish development. A deficiency of nat10 in zebrafish embryos resulted in increased mortality and developmental abnormalities. Behavioral and histological assessments indicated significant vision impairment in nat10 KD zebrafish. Transcriptomic analysis and RT-PCR identified substantial downregulation of retinal transcripts related to phototransduction, light response, photoreceptors, and visual perception in the nat10 KD group. Dot-blot and RIP-PCR analyses confirmed a pronounced reduction in ac4C levels in both total RNA and specifically in opsin messenger RNA (mRNA). Additionally, by evaluating mRNA decay in zebrafish treated with actinomycin D, we observed a significant decrease in the stability of opsin mRNA in the nat10 KD group.

Conclusions

The ac4C-mediated mRNA modification plays an essential role in maintaining visual development and retinal function. The loss of NAT10-mediated ac4C modification results in significant disruptions to these processes, underlining the importance of this RNA modification in ocular development.

Discovery of a new highly pathogenic toxin involved in insect sepsis

IMPORTANCE

As a current biocontrol resource, entomopathogenic nematodes and their symbiotic bacterium can produce many toxin factors to trigger insect sepsis, having the potential to promote sustainable pest management. In this study, we found Steinernema feltiae and Xenorhabdus bovienii were highly virulent against the insects. After infective juvenile injection, Galleria mellonella quickly turned black and softened with increasing esterase activity. Simultaneously, X. bovienii attacked hemocytes and released toxic components, resulting in extensive hemolysis and sepsis. Then, we applied high-resolution mass spectrometry-based metabolomics and found multiple substances were upregulated in the host hemolymph. We found extremely hazardous actinomycin D produced via 3-hydroxyanthranilic acid metabolites. Moreover, a combined transcriptomic analysis revealed that gene expression of proteins associated with actinomycin D was upregulated. Our research revealed actinomycin D might be responsible for the infestation activity of X. bovienii, indicating a new direction for exploring the sepsis mechanism and developing novel biotic pesticides.

Identification of Compounds Preventing A. fumigatus Biofilm Formation by Inhibition of the Galactosaminogalactan Deacetylase Agd3

The opportunistic fungus Aspergillus fumigatus causes a set of diseases ranging from allergy to lethal invasive mycosis. Within the human airways, A. fumigatus is embedded in a biofilm that forms not only a barrier against the host immune defense system, but also creates a physical barrier protecting the fungi from chemicals such as antifungal drugs. Novel therapeutic strategies aim at combining drugs that inhibit biofilm synthesis or disrupt existing biofilm with classical antimicrobials. One of the major constituents of A. fumigatus biofilm is the polysaccharide galactosaminogalactan (GAG) composed of α1,4-linked N-acetylgalactosamine, galactosamine, and galactose residues. GAG is synthesized on the cytosolic face of the plasma membrane and is extruded in the extracellular space, where it is partially deacetylated. The deacetylase Agd3 that mediates this last step is essential for the biofilm formation and full virulence of the fungus. In this work, a previously described enzyme-linked lectin assay, based on the adhesion of deacetylated GAG to negatively charged plates and quantification with biotinylated soybean agglutinin was adapted to screen microbial natural compounds, as well as compounds identified in in silico screening of drug libraries. Actinomycin X2, actinomycin D, rifaximin, and imatinib were shown to inhibit Agd3 activity in vitro. At a concentration of 100 µM, actinomycin D and imatinib showed a clear reduction in the biofilm biomass without affecting the fungal growth. Finally, imatinib reduced the virulence of A. fumigatus in a Galleria mellonella infection model in an Agd3-dependent manner.

Metastatic Rhabdomyosarcoma: Results of the European Paediatric Soft Tissue Sarcoma Study Group MTS 2008 Study and Pooled Analysis With the Concurrent BERNIE Study

PURPOSE

Outcome for patients with metastatic rhabdomyosarcoma (RMS) is poor. This study presents the results of the MTS 2008 study with a pooled analysis including patients from the concurrent BERNIE study.

PATIENTS AND METHODS

In MTS 2008, patients with metastatic RMS received four cycles of ifosfamide, vincristine, and actinomycin D (IVA) plus doxorubicin, five cycles of IVA, and 12 cycles of maintenance chemotherapy (low-dose cyclophosphamide and vinorelbine). The BERNIE study randomly assigned patients to the addition or not of bevacizumab to the same chemotherapy. Local therapy (surgery/radiotherapy) was given to the primary tumor and all metastatic sites when feasible.

RESULTS

MTS 2008 included 270 patients (median age, 9.6 years; range, 0.07-20.8 years). With a median follow-up of 50.3 months, 3-year event-free survival (EFS) and overall survival (OS) were 34.9% (95% CI, 29.1 to 40.8) and 47.9% (95% CI, 41.6 to 53.9), respectively. In pooled analyses on 372 patients with a median follow-up of 55.2 months, 3-year EFS and OS were 35.5% (95% CI, 30.4 to 40.6) and 49.3% (95% CI, 43.9 to 54.5), respectively. Patients with ≤ 2 Oberlin risk factors (ORFs) had better outcome than those with ≥ 3 ORFs: 3-year EFS was 46.1% versus 12.5% (P < .0001) and 3-year OS 60.0% versus 26.0% (P < .0001). Induction chemotherapy and maintenance appeared tolerable; however, about two third of patients needed dose adjustments during maintenance.

CONCLUSION

Outcome remains poor for patients with metastatic RMS and multiple ORFs. Because of the design of the studies, it was not possible to determine whether the intensive induction regimen and/or the addition of maintenance treatment resulted in apparent improvement of outcome compared with historical cohorts. Further studies, with novel treatment approaches are urgently needed, to improve outcome for the group of patients with adverse prognostic factors.

Codon Usage and mRNA Stability are Translational Determinants of Cellular Response to Canonical Ferroptosis Inducers

Ferroptosis is a non-apoptotic cell death mechanism characterized by the generation of lipid peroxides. While many effectors in the ferroptosis pathway have been mapped, its epitranscriptional regulation is not yet fully understood. Ferroptosis can be induced via system xCT inhibition (Class I) or GPX4 inhibition (Class II). Previous works have revealed important differences in cellular response to different ferroptosis inducers. Importantly, blocking mRNA transcription or translation appears to protect cells against Class I ferroptosis inducing agents but not Class II. In this work, we examined the impact of blocking transcription (via Actinomycin D) or translation (via Cycloheximide) on Erastin (Class I) or RSL3 (Class II) induced ferroptosis. Blocking transcription or translation protected cells against Erastin but was detrimental against RSL3. Cycloheximide led to increased levels of GSH alone or when co-treated with Erastin via the activation of the reverse transsulfuration pathway. RNA sequencing analysis revealed early activation of a strong alternative splice program before observed changes in transcription. mRNA stability analysis revealed divergent mRNA stability changes in cellular response to Erastin or RSL3. Importantly, codon optimality biases were drastically different in either condition. Our data also implicated translation repression and rate as an important determinant of the cellular response to ferroptosis inducers. Given that mRNA stability and codon usage can be influenced via the tRNA epitranscriptome, we evaluated the role of a tRNA modifying enzyme in ferroptosis stress response. Alkbh1, a tRNA demethylase, led to translation repression and increased the resistance to Erastin but made cells more sensitive to RSL3.

CircZNF644 aggravates lipopolysaccharide-induced HK-2 cell impairment via the miR-140-5p/MLKL axis

Circular RNAs (circRNAs) play vital roles in human diseases, including acute kidney injury (AKI). In this paper, we focused on the effect of circRNA zinc finger protein 644 (circZNF644) on AKI cell model progression. qRT-PCR was conducted for the levels of circZNF644, ZNF644, miR-140-5p and mixed lineage kinase domain like pseudokinase (MLKL). RNase R assay, actinomycin D assay and subcellular fraction analysis were conducted to analyze the features of circZNF644. CCK-8 assay and EdU assay were used to explore cell proliferation. Flow cytometry analysis was conducted to analyze cell cycle and cell apoptosis. Western blot assay was executed for protein levels. ELISA was performed for the levels of inflammatory cytokines. The relationships among circZNF644, miR-140-5p and MLKL were analyzed by dual-luciferase reporter assay and RIP assay. CircZNF644 was upregulated in LPS-stimulated HK-2 cells. LPS-mediated inhibitory effects on cell proliferation and cell cycle and promotional effects on apoptosis and inflammation were reversed by circZNF644 knockdown. CircZNF644 directly interacted with miR-140-5p and MLKL was the target gene of miR-140-5p. The impact of circZNF644 knockdown on HK-2 cell injury was relieved by miR-140-5p inhibition. Moreover, miR-140-5p enhancement alleviated LPS-triggered HK-2 cell damage, while MLKL elevation reversed the effect. CircZNF644 knockdown protected HK-2 cells from LPS-induced injury by altering miR-140-5p/MLKL pathway, suggesting that circZNF644 may be a hopeful therapeutic target for AKI.

Outcome of SIOP patients with low- or intermediate-risk Wilms tumour relapsing after initial vincristine and actinomycin-D therapy only - the SIOP 93-01 and 2001 protocols

PURPOSE

Society of International Pediatric Oncology - Renal Tumor Study Group (SIOP-RTSG) treatment recommendations for relapsed Wilms tumour (WT) are stratified by the intensity of first-line treatment. To explore the evidence for the treatment of patients relapsing after vincristine and actinomycin-D (VA) treatment for primary WT, we retrospectively evaluated rescue treatment and survival of this patient group.

PATIENTS AND METHODS

We included 109 patients with relapse after VA therapy (no radiotherapy) for stage I-II primary low- or intermediate-risk WT from the SIOP 93-01 and SIOP 2001 studies. Univariate Cox regression analysis was performed to study the effect of relapse treatment intensity on event-free survival (EFS) and overall survival (OS). Relapse treatment intensity was classified into vincristine, actinomycin-D, and either doxorubicin or epirubicin (VAD), and more intensive therapies (ifosfamide/carboplatin/etoposide [ICE]/≥ 4 drugs/high-dose chemotherapy with haematopoietic stem cell transplantation [HD HSCT]).

RESULTS

Relapse treatment regimens included either VAD, or cyclophosphamide/carboplatin/etoposide/doxorubicin (CyCED), or ICE backbones. Radiotherapy was administered in 62 patients and HD HSCT in 15 patients. Overall, 5-year EFS and OS after relapse were 72.3% (95% confidence interval [CI]: 64.0-81.6%) and 79.3% (95% CI: 71.5-88.0%), respectively. Patients treated with VAD did not fare worse when compared with patients treated with more intensive therapies (hazard ratio EFS: 0.611 [95% CI: 0.228-1.638] [p-value = 0.327] and hazard ratio OS: 0.438 [95% CI: 0.126-1.700] [p-value = 0.193]).

CONCLUSION

Patients with relapsed WT after initial VA-only treatment showed no inferior EFS and OS when treated with VAD regimens compared with more intensive rescue regimens. A subset of patients relapsing after VA may benefit from less intensive rescue treatment than ICE/CyCED-based regimens and deserve to be pinpointed by identifying additional (molecular) prognostic factors in future studies.

Characteristics and outcome of children with renal tumors in the Netherlands: The first five-year's experience of national centralization

Around 6% of all childhood malignancies represent renal tumors, of which a majority includes Wilms tumor (WT). Although survival rates have improved over the last decades, specific patients are still at risk for adverse outcome. In the Netherlands, since 2015, pediatric oncology care for renal tumors has been centralized in the Princess Máxima Center for Pediatric Oncology. Here, we describe experiences of the first 5 years of centralized care and explore whether this influences the epidemiological landscape by comparing data with the Netherlands Cancer Registry (NCR). We identified all patients <19 years with a renal mass diagnosed between 01-01-2015 and 31-12-2019 in the Princess Máxima Center. Epidemiology, characteristics and management were analyzed. We identified 164 patients (including 1 patient who refused consent for registration), in our center with a suspicion of a renal tumor. The remaining 163 cases included WT (n = 118)/cystic partially differentiated nephroblastoma (n = 2)/nephrogenic rests only (n = 6) and non-WT (n = 37). In this period, the NCR included 138 children, 1 17-year-old patient was not referred to the Princess Máxima Center. Central radiology review (before starting treatment) was performed in 121/163 patients, and central pathology review in 148/152 patients that underwent surgery. Treatment stratification, according to SIOP/EpSSG protocols was pursued based on multidisciplinary consensus. Preoperative chemotherapy was administered in 133 patients, whereas 19 patients underwent upfront surgery. Surgery was performed in 152 patients, and from 133 biomaterial was stored. Centralization of care for children with renal tumors led to referral of all but 1 new renal tumor cases in the Netherlands, and leads to referral of very rare subtypes not registered in the NCR, that benefit from high quality diagnostics and multidisciplinary decision making. National centralization of care led to enhanced development of molecular diagnostics and other innovation-based treatments for the future.

Position paper: Rationale for the treatment of Wilms tumour in the UMBRELLA SIOP-RTSG 2016 protocol

The Renal Tumour Study Group of the International Society of Paediatric Oncology (SIOP-RTSG) has developed a new protocol for the diagnosis and treatment of childhood renal tumours, the UMBRELLA SIOP-RTSG 2016 (the UMBRELLA protocol), to continue international collaboration in the treatment of childhood renal tumours. This protocol will support integrated biomarker and imaging research, focussing on assessing the independent prognostic value of genomic changes within the tumour and the volume of the blastemal component that survives preoperative chemotherapy. Treatment guidelines for Wilms tumours in the UMBRELLA protocol include recommendations for localized, metastatic, and bilateral disease, for all age groups, and for relapsed disease. These recommendations have been established by a multidisciplinary panel of leading experts on renal tumours within the SIOP-RTSG. The UMBRELLA protocol should promote international collaboration and research and serve as the SIOP-RTSG best available treatment standard.

Protective, elective lung irradiation in non-metastatic Ewing's sarcoma

Ewing's sarcoma in childhood is a disease from family of the peripheral primitive neuroectodermal tumours. For a period of 16 y (1984-2000), 34 children with Ewing's sarcoma were treated and followed in our department. Twenty-seven of these patients were without distant metastases. Complex treatment was applied to all these patients-chemotherapy VACA (vincristine, actinomycin D, cyclophosphamide, adriamycin), local radiotherapy to a total dose of 50-56 Gy +/- surgery. After, a local tumour control was achieved in 11 children with non-metastatic Ewing's sarcoma, elective whole lung irradiation to a total dose of 12-15 Gy was applied. Our experience in these 11 patients with non-metastatic Ewing's sarcoma, in whom elective lung irradiation was applied, showed significant reduction in the lung metastases, improved free of disease survival and overall survival. The achieved good treatment results necessitate extending this treatment approach through defining the risk groups of patients, suitable for elective lung radiotherapy combined with chemotherapy in non-metastatic Ewing's sarcoma.

Fractionation of Nucleic Acids from Polio-Infected He La Cells

The nucleic acids synthesised in poliovirus infected HeLa cells in the presence of actinomycin D were fractionated by means of a methylated albumin column.

Beside the bulk of infectious viral RNA several other peaks were observed.

[Expression of herpes simplex virus type 2 latency associated transcript ORF1 and its anti-apoptotic function]

To study the expression of herpes simplex virus type 2 latency-associated transcript (LAT) open reading frame 1 (ORF1) and its anti-apoptosis function induced by actinomycin D in Vero cells. The recombinant plasmid pEGFP-ORF1 was constructed and transfected into Vero cells, and the expression of ORF1 was identified by RT-PCR. The changes of Vero cells morphology induced by actinomycin D were observed by fluorescence microscopy, Hochest33258 fluorescence staining. Cells viability was evaluated by MTT assay and cells apoptosis rate was detected by flow cytometry. Double digestion and sequencing confirmed the pEGFP-ORF1 was constructed successfully, RT-PCR showed that the target gene was highly expressed in Vero cells. Hochest33258 staining reaveals that Vero cells transfected with pEGFP-ORF1 and induced apoptosis by actinomycin D had no changes in morphology. MTT assay showed that the viabilities of Vero cells transfected with recombinant plasmid pEGFP-ORF1 and induced apoptosis by actinomycin D has no statistically significant difference compared with the untreated normal control group (P > 0.05), but remarkable higher than Vero cells transfected with empty plasmid pEGFP-C2 and induced apoptosis by actinomycin D, the difference was statistically significant (P < 0.05). Flow cytometry assay shows that the cells apoptosis rate had no significant difference between pEGFP-ORF1 group and the normal group, but the cells apoptosis rate ofpEGFP-ORF1 was lower than the pEGFP-C2 group. HSV-2 LAT ORF1 gene can be expressed in Vero cells and can protect Vero cells from apoptosis induced by actinomycin D.

Constitutive activity of Erk1/2 and NF-κB protects human endometrial stromal cells from death receptor-mediated apoptosis

Apoptosis in the human endometrium plays an essential role for endometrial receptivity and early implantation. A dysbalance of pro- and anti-apoptotic events in the secretory endometrium seems to be involved in implantation disorders and consecutive pregnancy complications. However, little is known about the mechanisms regulating apoptosis-sensitivity in the human endometrium. Therefore this study was performed to identify molecular mechanisms underlying the resistance toward apoptosis in human endometrial stromal cells (ESCs). Human ESCs were isolated from hysterectomy specimens and used as undifferentiated cells or after decidualization in vitro. Cells were incubated with an activating anti-Fas antibody, tumor-necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), TNF-α and inhibitors of protein- and RNA-syntheses, a caspase-inhibitor and inhibitors of extracellular signal regulated kinase (Erk)1/2, nuclear factor (NF)-κB and Akt. Apoptosis was measured by flow cytometric detection of hypodiploid nuclei. Caspase-activity was detected by luminescencent assays. Several pro- and anti-apoptotic molecules and the activation of Erk1/2, NF-κB and Akt were analyzed by in-cell Western assays or flow cytometry. Inhibition of protein- and RNA-syntheses differentially sensitized human ESCs for death receptor-mediated apoptosis in a caspase-dependent manner, based on the up-regulation of the death receptors Fas and TRAIL-R2. The constitutive activity of Erk1/2 and NF-κB could be identified as a reason for the apoptosis-resistance of human ESCs. These results suggest the pro-survival signaling pathways Erk1/2 and NF-κB as key regulators of the sensitivity of human ESCs for death receptor-mediated apoptosis. The modulation of these pathways might play an important role in the physiology of implantation.

NMDA receptor subunits in the adult rat hippocampus undergo similar changes after 5 minutes in an open field and after LTP induction

NMDA receptor subunits change during development and their synaptic expression is modified rapidly after synaptic plasticity induction in hippocampal slices. However, there is scarce information on subunits expression after synaptic plasticity induction or memory acquisition, particularly in adults. GluN1, GluN2A and GluN2B NMDA receptor subunits were assessed by western blot in 1) adult rats that had explored an open field (OF) for 5 minutes, a time sufficient to induce habituation, 2) mature rat hippocampal neuron cultures depolarized by KCl and 3) hippocampal slices from adult rats where long term potentiation (LTP) was induced by theta-burst stimulation (TBS). GluN1 and GluN2A, though not GluN2B, were significantly higher 70 minutes –but not 30 minutes- after a 5 minutes session in an OF. GluN1 and GluN2A total immunofluorescence and puncta in neurites increased in cultures, as evaluated 70 minutes after KCl stimulation. Similar changes were found in hippocampal slices 70 minutes after LTP induction. To start to explore underlying mechanisms, hippocampal slices were treated either with cycloheximide (a translation inhibitor) or actinomycin D (a transcription inhibitor) during electrophysiological assays. It was corroborated that translation was necessary for LTP induction and expression. The rise in GluN1 depends on transcription and translation, while the increase in GluN2A appears to mainly depend on translation, though a contribution of some remaining transcriptional activity during actinomycin D treatment could not be rouled out. LTP effective induction was required for the subunits to increase. Although in the three models same subunits suffered modifications in the same direction, within an apparently similar temporal course, further investigation is required to reveal if they are related processes and to find out whether they are causally related with synaptic plasticity, learning and memory.

Cloning and characterization of a dronc homologue in the silkworm, Bombyx mori

We cloned and characterized a novel Bombyx mori homologue (bm-dronc) of Drosophila melanogaster dronc (dm-dronc), which could encode a polypeptide of 438 amino acid residues. Bm-Dronc shares relatively low amino acid sequence identities of 25% and 26% with Dm-Dronc and Aedes aegypti Dronc (Aa-Dronc), respectively. Bm-Dronc has the sequence QACRG surrounding the catalytic site (C), which is consistent with the QAC(R/Q/G)(G/E) consensus sequence in most caspases but distinct from the sequences PFCRG and SICRG of Dm-Dronc and Aa-Dronc, respectively. Bm-Dronc possesses a long N-terminal prodomain containing a caspase recruitment domain (CARD), a p20 domain and a p10 domain, exhibiting cleavage activities on synthetic substrates Ac-VDVAD-AMC, Ac-IETD-AMC and Ac-LEHD-AMC, which are preferred by human initiator caspases-2, -8 and -9, respectively. Bm-Dronc transiently expressed in insect cells and Escherichia coli cells underwent spontaneous cleavage and caused apoptosis and stimulation of caspase-3-like protease activity in various lepidopteran cell lines, but not in the dipteran cell line D. melanogaster S2. The apoptosis and the stimulation of caspase-3-like protease activity induced by Bm-Dronc overexpression were abrogated upon transfection with either a double-stranded RNA against bm-dronc or a plasmid expressing functional anti-apoptotic protein Hycu-IAP3 encoded by the baculovirus Hyphantria cunea multiple nucleopolyhedrovirus (MNPV). Apoptosis induction in BM-N cells by infection with a p35-defective Autographa californica MNPV or exposure to actinomycin D and UV promoted the cleavage of Bm-Dronc. These results indicate that Bm-Dronc serves as the initiator caspase responsible for the induction of caspase-dependent apoptosis.

A note on the stability of actinomycin D

Visible absorption spectra and an agar-diffusion microbiological assay with Staphylococcus aureus were used to examine the effects of temperature, time, and pH on the stability of actinomycin D in distilled water, Clark and Lubs buffer solutions, and plasma. The most stable storage pH range for actinomycin D in buffer solution is 5 to 7. Actinomycin D in distilled water and stored 5° C (refrigeration) preserved its stability for at least 150 days. Except in buffer at pH 5, the antibiotic is appreciably degraded by autoclaving.

Primary adult intratesticular rhabdomyosarcoma: results of the treatment of six cases

The aim of the present study was to assess the treatment outcomes in a cohort of adult patients with intratesticular rhabdomyosarcoma. Between 1999 and 2008, 296 patients underwent radical orchiectomy for intrascrotal mass. A retrospective chart review was carried out for adult patients diagnosed with intratesticular rhabdomyosarcoma. Overall, six patients (mean age 21 years, range 17-23) were included: five had embryonic rhabdomyosarcoma and one had pleomorphic rhabdomyosarcoma. Four patients underwent retroperitoneal lymph node dissection and five patients had postoperative chemotherapy. The mean length of follow up was 28 months (range 12-51 months). One patient was lost to follow up after 26 months, five cases remained alive at the end of the study. Surgical resection with chemotherapy was an effective way to achieve favorable outcomes and long-term survival in adult patients with metastases from intratesticular rhabdomyosarcoma.

Vacuum-assisted biopsies under MR guidance: results of 72 procedures

OBJECTIVE

To investigate the clinical accuracy of magnetic resonance imaging-guided breast vacuum-assisted biopsy (MR-VAB).

METHODS

Of 97 scheduled MR-VAB for single MRI lesions (negative second-look sonography) categorised as BI-RADS 4 or 5, 4 were cancelled (undetected lesion = 2, technical problems = 2). Twenty-one patients lost to follow-up were excluded.

RESULTS

Twenty-three patients (median age 51 years) were at high risk (BRCA1 = 11, BRCA2 = 7, familial risk = 5), 23 had a suspected local recurrence of breast cancer. Seventy-two imaged lesions (focus = 1, mass enhancement = 32, non-mass-like enhancement = 39) were targeted with a 10-gauge VAB probe using MRI guidance, with a median of 18 specimens per lesion (median procedural time 72 min, range 50-131 min) followed by clip placement. In the case of benignity, MRI follow-up was performed (19 patients, median 389 days, range 33-1,592) or mammography (3 patients, median 420 days, range 372-1,354). According to histopathology results, 29 lesions were benign, 10 were high-risk (papillary = 2, radial scar = 1, atypical epithelial hyperplasia = 7) and 33 malignant (ductal carcinoma in situ = 8, invasive cancers = 25). Three false negative results and 3 complications occurred (1 malaise, 1 skin defect, 1 infection).

CONCLUSION

MRI-guided VAB represents an accurate tool for the histological diagnosis of lesions visible only at MRI.

[Impact of exogenous glycine on actinomycin D resistance of Staphylococcus aureus strain adapted to the antibiotic]

The impact of glycine, added to the cultivation medium, on resistance of Staphylococcus aureus strains to actinomycin D and gramicidin S was studied. The antibiotic resistant strains were isolated after cultivation of the susceptible S. aureus strain 209P on media with increasing concentrations of actinomycin or gramicidin. When the strains were grown on the glycine-containing medium. i. e. under the conditions providing replacement of D-alanine by glycine in the C-end dipeptides of peptidoglycanes, the resistance of the staphylococci to actinomycin markedly decreased. However, in the resistant cells, characterized by significant thickening of the cell walls, the peptidoglycane quantity per a biomass unit did not lower, that was evident of preservation of the wall thickness. At the same time, with addition of glycine to the medium there was observed increased ability of the cells to bind actinomycin. When the gramicidin-adapted strains were grown on the glycine-containing medium, their resistance to the antibiotic did not change. The modification of the peptidoglycane C-end dipeptides probably lowered the protective role of the thicker walls of the cells on their contact with actinomycin but not gramicidin.

Engulfed cell remnants, and not cells undergoing apoptosis, constitute the LE-cell phenomenon

The LE cell has been one of the first immunological signs of active systemic lupus erythematosus, included into the ACR criteria. LE cells consist of a phagocyte engulfing material of disputed origin, which was interpreted as either cellular remnants from necrotic cells or as early apoptotic cells. It is well established that LE cell formation is dependent on autoantibodies against the linker histone H1. In view of this fact, we investigated whether anti-histone H1 antibodies and LE cell positive sera bound to cells where apoptosis had been induced by gliotoxin or actinomycin D or which were necrotic after heating. Necrotic cell remnants, but not (early) apoptotic cells were bound by anti-histone H1 antibodies and LE cell positive sera, establishing that the process of LE cell formation, which is dependent on anti-H1 binding, leads to engulfment of necrotic (or late apoptotic) material, but not of early apoptotic cells.

Apoptosis in Vero cells infected with Akabane, Aino and Chuzan virus

Akabane, Aino and Chuzan virus are arthropod-borne (arbo) viruses mainly associated with reproductive failures in cattle. We investigated apoptosis in Vero cells (C-1586) infected with Akabane, Aino and Chuzan virus. The fragmentation of chromosomal DNA was simultaneously detected with the progress of cytopathic effect from 48 hr to 72 hr post infection, depending on viruses. Although the treatment of cycloheximide blocked apoptosis in Vero cells infected with three viruses, actinomycin D did not prevent DNA oligomerization, thus indicating that de novo viral protein synthesis is critical for viral apoptosis. In addition, the activation of caspase-3 was also detected in Vero cells by indirect fluorescent assay. From the present results, it is of future interest whether apoptotic characteristics of these viruses are related to pathogenecity in vivo.

[Relapses in children with nephroblastoma--a single centre experience]

The aim of the study was to assess the incidence of relapse and outcome of treatment in children with nephroblastoma relapse.

MATERIAL AND METHODS

In the years 1989-2002 at our centre 67 children were treated for nephroblastoma. Patients were divided into two subgroups. Group I comprised 25 children treated in accordance with the SIOP-9 programme, whilst group II consisted of 42 patients following the SIOP 93-01 protocol.

RESULTS

In group I, five children had relapse diagnosed: local in 2, pulmonary in 2 and cerebral in one case. Two of the cases were diagnosed during the treatment, and the other 3 after 1 to 19 months from the completion of treatment. In group II relapse was diagnosed in 4 children: local in 2 and pulmonary in 2 cases. One case was diagnosed while on treatment, and the other 3 were diagnosed 1,2 and 4 months after completion of treatment. Among the children who followed the SIOP-9 programme three patients died, while among those following SIOP 93-01 two patients died.

CONCLUSIONS

The prognosis in patients who relapsed remains uncertain. The histological type of tumour and the moment of relapse occurrence are significant prognostic factors.

Gene transfer of baculoviral p35 by adenoviral vector protects human cerebral neurons from apoptosis

Apoptosis plays an important role in neuronal cell death in both chronic and acute human neurological diseases, including ALS, Huntington's disease, cerebral ischemia, and HIV encephalopathy. We evaluated the ability of an extremely powerful antiapoptotic agent, baculoviral p35, to prevent apoptosis and cell death of human cerebral neurons that undergo severe neurotoxic changes in a culture system when treated with agents that are implicated in human neurological disorders, that is, tumor necrosis factor (TNFalpha) and the HIV proteins Tat and gp120. P35 is a potent broad-spectrum antiapoptotic protein derived from baculovirus, that inhibits nearly all caspases, and has other antiapoptotic actions as well. Adenoviral vectors expressing p35 (Ad. p35) or a control gene (lacZ) efficiently transduced human neurons. Treatment of control cultures with the toxic agents TNFalpha, TNFalpha plus Actinomycin D, or Tat and gp120, induced neurotoxicity and death of neurons. Transduction of neurons with Ad. p35 blocked apoptosis, and eliminated cell death due to TNFalpha, or Tat and gp120. Viral vector transfer of the p35 gene efficiently protects human neurons from TNFalpha, or Tat and gp120-induced apoptosis and cell death. These results suggest that p35 transduction of neurons by viral vectors could be therapeutically useful in the treatment of human neurodegenerative diseases.

Protective effect of distillate and redistillate of cow's urine in human polymorphonuclear leukocytes challenged with established genotoxic chemicals

OBJECTIVE

From the ancient period cow's urine has been used as a medicine. In Veda, cow's urine was compared to the nectar. In Susrut, several medicinal properties of cow's urine have been mentioned and are known to cause weight loss, reversal of certain cardiac and kidney problems, indigestion, stomach ache, edema, etc. However, the literature and scripture did not mention the antigenotoxic properties of cow's urine.

METHODS

In the present investigation, the antigenotoxic/antioxidant properties of cow's urine distillate and redistillate were studied in vitro. The antioxidant status and volatile fatty acid levels were determined. Actinomycin-D (0.1 micromol/L) and hydrogen peroxide (150 micromol/L) were used for inducing DNA strand break with 0.1% DMSO as negative control. Dose for the antigenotoxic effect of cow's urine was chosen from the dose response study carried out earlier.

RESULTS

Both actinomycin-D and H202 caused statistically significant DNA unwinding of 80% & 75% respectively (P < 0.001) as revealed by fluorimetric analysis of DNA unwinding (FADU), and the damage could be protected with the redistilled cow's urine distillate (1, 50 & 100 microL) in simultaneous treatment with genotoxic chemicals.

CONCLUSION

The redistillate of cow's urine was found to possess total antioxidant status of around 2.6 mmol, contributed mainly by volatile fatty acids (1500 mg/L) as revealed by the GC-MS studies. These fatty acids and other antioxidants might cause the observed protective effects.

Gene expression profiles of apoptotic neurons

The multigenic program underlying neuronal apoptosis is mostly unknown. To study the program, we used genome-scale screening by oligonucleotide microarrays during serum and potassium deprivation-induced apoptosis of cerebellar granule neurons. From the 8740 genes interrogated by the arrays, 423 genes were found to be regulated at both the transcriptional and the posttranscriptional level and segregated into distinct clusters. Semantic clustering based on gene ontologies showed coordinated expression of genes with common biological functions and metabolic pathways. Among the genes implicated in apoptotic cerebellar granule neurons, 70 were in common with those differentially expressed in cortical neurons exposed to amyloid beta-protein, indicating the existence of common mechanisms responsible for neuronal cell death. Our results offer a genomic view of the changes that accompany neuronal apoptosis and yield new insights into the underlying molecular basis.

Mucositis and airway obstruction in a pediatric patient

Pediatric patients undergoing induction regimens of chemotherapy may require intubation and mechanical ventilation either for respiratory failure or airway compromise as a complication of their therapy. We describe a case of difficult airway management resulting from pseudomembrane formation in a 16-yr-old girl. The patient was undergoing induction chemotherapy for stage IV rhabdomyosarcoma and developed severe mucositis that led to progressive airway obstruction.

Immunogenicity of the histidine-to-tyrosine staphylococcal enterotoxin B mutant protein in C3H/HeJ mice

Staphylococcal enterotoxin B (SEB) is a common cause of food poisoning and toxic shock. A safe and effective vaccine is needed to protect against the superantigenic effects of this toxin. We previously constructed and produced an apparently nontoxic SEB mutant having four histidine-to-tyrosine substitutions in positions 12, 32, 105, and 121. In the present study, we found that this H1.2.3.4 SEB mutant had low toxicity, was able to induce high levels of specific IgG antibodies, and protected mice in both the actinomycin D-primed and intranasal SEB intoxication model systems, despite the absence of detectable specific IgM and IgA antibodies. We propose further development of the H1.2.3.4 recombinant protein as a potential anti-SEB vaccine candidate.

Coordinate down-regulation of cartilage matrix gene expression in Bcl-2 deficient chondrocytes is associated with decreased SOX9 expression and decreased mRNA stability

The anti-apoptotic protein Bcl-2 has been shown to function in roles unrelated to apoptosis in a variety of cell types. We have previously reported that loss of Bcl-2 expression alters chondrocyte morphology and modulates aggrecan expression via an apoptosis-independent pathway. Here we show that Bcl-2 is required for chondrocytes to maintain expression of a variety of cartilage-specific matrix proteins. Using quantitative, real-time PCR, we demonstrate that Bcl-2-deficient chondrocytes coordinately down-regulate genes coding for hyaline cartilage matrix proteins including collagen II, collagen IX, aggrecan, and link protein. The decrease in steady-state level of these mRNA transcripts results, in part, from decreased mRNA stability in Bcl-2-deficient chondrocytes. Transcriptional regulation is also likely involved because chondrocytes with decreased Bcl-2 levels show decreased expression of SOX9, a transcription factor necessary for expressing the major cartilage matrix proteins. In contrast, chondrocytes constitutively expressing Bcl-2 have a stable phenotype when subjected to loss of serum factor signaling. These cells maintain high levels of SOX9, as well as the SOX9 targets collagen II and aggrecan. These results suggest that Bcl-2 is involved in a pathway important for maintaining a stable chondrocyte phenotype.

Gestational trophoblastic syndrome: an audit of 112 patients. A South African experience

Gestational trophoblastic disease (GTD) represents a spectrum of histologically distinct entities including molar pregnancy and choriocarcinoma. The incidence of GTD varies in different parts of the world with high incidences in countries like Japan (2 / 1000 pregnancies). With the advent of sensitive assays for detection of serum beta human chorionic gonadotrophin (HCG) and ultrasound, GTD can now be detected earlier in pregnancy. To date no studies have been reported from South Africa regarding the epidemiology, management, and outcome of patients with GTD. This study was a retrospective audit based on 112 patients with GTD treated at King Edward VIII Hospital, Durban, South Africa. Clinical records of patients were reviewed with regards to presentation, investigation, management and outcome. Of 112 patients, there were 78 patients (70%) with hydatidiform mole and 34 patients (30%) with choriocarcinoma. The mean age of patients was 28.5 years (SD 8.1 years). The majority of patients were Black females (94.6%) while 4.4% were Asian and 1% Coloured females. The most common presenting symptom was vaginal bleeding (93.8%). There were 74 patients (66.7%) who had a previous normal term pregnancy and only two patients (1.8%) had previous molar pregnancies. Suction curettage was the main treatment modality for patients with molar pregnancy while choriocarcinoma was treated primarily with chemotherapy. A total of 72 percent of patients with molar pregnancy and 28 percent with choriocarcinoma had complete remission after initial treatment. Twelve patients died during the course of treatment mainly due to late presentation and advanced metastatic disease. Complete cure was achieved in 89% of patients. Age, parity, previous history, initial uterine size, presence of theca-lutein cysts, and initial betaHCG concentration was not found to be prognostic for persistent trophoblastic disease. In the present study, the incidence of molar pregnancy and choriocarcinoma was 1.2 / 1000 and 0.5 / 1000 deliveries, respectively. This is much lower than those quoted from countries such as Japan. However, the incidence quoted from our study may be overestimated as this was a hospital-based study and most of the uncomplicated deliveries occur in referring centers. Only 20% of patients in this study were above the age of 35 years with a mean age of 28.5 years. The majority of patients were of Black African ethnic origin mainly due to the fact that our hospital is a referral center for Black patients. Similar to other studies, the majority of patients with molar pregnancy were treated with suction curettage while the majority of patients with choriocarcinoma were treated with chemotherapy. Overall, spontaneous remission was achieved in 60% of patients with molar pregnancy and an overall complete cure was achieved in 89% of patients.

Mechanisms of bFGF and NT-4 potentiation of necrotic neuronal death

The effects of neurotrophic factors on necrotic neuronal death are controversial. In this study we found that both neurotrophin-4 (NT-4) and basic fibroblast growth factor (bFGF) potentiated necrotic neuronal death caused by exposure to oxygen-glucose deprivation or iron-citrate (Fe) in cortical cultures. However, there were significant differences in the actions of the two neurotrophic factors. Neurotrophin-4 protected against apoptotic neuronal death, while bFGF had no effect on apoptotic death in these cultures. Furthermore, potentiation of oxygen-glucose deprivation induced necrotic death by NT-4 required pretreatment (24 h), while pretreatment with bFGF had no effect. However, acute treatment with bFGF during oxygen-glucose deprivation did potentiate neuronal death. Both neurotrophic factors potentiated free radical mediated necrotic neuronal death induced by exposure to Fe. However, the RNA synthesis inhibitor, actinomycin-D, blocked the injury potentiation by NT-4, but not that caused by bFGF. Also, NT-4, but not bFGF, potentiated Fe induced necrotic death in pure neuronal cultures. Expression of mRNA for FGF receptors FGFR1 and FGFR2 was observed at high levels in astrocytes. The results indicate that the injury enhancing effects of bFGF are acute, while those of NT-4 require prolonged exposure and new protein synthesis. Furthermore, the effects of bFGF appear to be mediated through actions on astrocytes, while NT-4 appears to act directly on neurons. The fact that neurotrophic factors from two distinct families can potentiate neuronal death by two different mechanisms suggests that such injury potentiation may be a common concern regarding the use of neurotrophic factors.

A 3'-UTR variant of the inducible porcine hsp70.2 gene affects mRNA stability

Large individual differences were observed in the abundance of transcripts from the hsp70.2 gene in primary fibroblast cultures sampled from 15 different pigs. While previously described functional promoter variants of this gene can partly account for the high variability of heat-induced increased abundance of transcripts, they are unrelated to the observed highly variable absolute amounts of hsp70.2 transcripts. Comparative sequence analysis revealed an alteration of the 3'-untranslated region (3'-UTR) sequences in these samples. The variant 3'-UTR allele proved to increase the half life of the hsp70.2 mRNA in reporter gene assays. It is suggested that the cellular stress response is significantly affected by the action and interaction of both promoter and 3'-UTR variants of the hsp70.2 gene.

[Chromosome CPD(PI/DAPI)- and CMA/DAPI-banding patterns in Allium cepa L]

Chromosome banding patterns of Allium cepa L. were obtained by using fluorochrome combinations chromomycin A3 (CMA) + 4',6-diamidino-2-phenylindole (DAPI), DAPI + actinomycin D (AMD) and propidium iodide (PI) + DAPI. In A. cepa, telomeric heterochromatin displayed dull fluorescence after staining with DAPI and DAPI/AMD. After staining with the GC-specific CMA and AT-specific DAPI, the CMA-positive fluorescence of the NOR region and the telomeric bands of C-heterochromatin was observed. In combination with DAPI, PI, a dye with low AT/GC specificity, produced almost uniform fluorescence of chromosomal arms and heterochromatin, whereas the NOR-adjoining regions displayed bright fluorescence. Denaturation of chromosomal DNA (95 degrees C for 1-3 min) followed by renaturation in the 2 x SSC buffer (37 degrees C, 12 h) altered the chromosome fluorescence patterns: specific PI-positive bands appeared and the contrast of CMA-banding increased. Bright fluorescence of the NOR and adjoining regions was also observed in the case. Three-minute denaturation led also to a bright PI-positive fluorescence of telomeric heterochromatin. The denaturation of chromosomal DNA before staining results in changes of the DAPI fluorescence pattern and in the appearance of DAPI fluorescence in GR-rich NOP regions. The mechanisms underlying the effects of denaturation/renaturation procedures on chromosome banding patterns obtained with different fluorochromes are discussed.

[Effect of cloned DNA fragment from Streptomyces chrysomallus No.2 on metabolism in Streptomyces strains]

The effects on cloned DNA fragment carrying an actinomycin resistance determinant on physiological processes in streptomyces strains with various potencies in producing this antibiotic, their inactive mutants, and model strain of Streptomyces lividans 66 were studied. This fragment was shown to modulate bacterial resistance to actinomycin and biosynthesis of antibiotics.

Transitional cell carcinoma of the urinary bladder following exposure to cyclophosphamide in childhood

With the increasing survival of children with malignancies, the long-term effects of chemotherapies are now becoming important and one of these dreadful long-term complications is the development of a second malignancy. Described here is a case of transitional cell carcinoma of the bladder developing 8 years following exposure to cyclophosphamide for the treatment of embryonal rhabdomyosarcoma.

The mode of actions of lysozyme as an immunoglobulin production stimulating factor

As we demonstrated before, hen egg white lysozyme stimulates immunoglobulin production by a human-human hybridoma line, HB4C5 cells and human peripheral blood lymphocytes. Then, the mode of actions of lysozyme as an immunoglobulin production stimulating factor was investigated. The immunoglobulin production stimulating activity of lysozyme was inactivated by trypsin digestion, even though the enzymatic activity was completely preserved. This fact suggests that the immunoglobulin production stimulating effect of lysozyme is irrelevant to its enzymatic function. Furthermore, this means that the effect is a novel function of this enzyme. Lysozyme enhanced IgM production by transcription-suppressed HB4C5 cells treated with actinomycin D. However, the enzyme was ineffective to accelerate IgM production by translation-suppressed HB4C5 cells treated with cycloheximide or sodium fluoride. In addition, the intracellular IgM content of HB4C5 cells treated with monensin for suppression of the post-transcription activity was obviously increased by lysozyme, although the secretion of IgM was inhibited. These findings suggest that lysozyme accelerates the translation process to enhance immunoglobulin productivity.