Single agent subcutaneous blinatumomab for advanced acute lymphoblastic leukemia

Blinatumomab is a BiTE® (bispecific T-cell engager) molecule that redirects CD3+ T-cells to engage and lyse CD19+ target cells. Here we demonstrate that subcutaneous (SC) blinatumomab can provide high efficacy and greater convenience of administration. In the expansion phase of a multi-institutional phase 1b trial (ClinicalTrials.gov, NCT04521231), heavily pretreated adults with relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL) received SC blinatumomab at two doses: (1) 250 μg once daily (QD) for week 1 and 500 μg three times weekly (TIW) thereafter (250 μg/500 μg) or (2) 500 μg QD for week 1 and 1000 μg TIW thereafter (500 μg/1000 μg). The primary endpoint was complete remission/complete remission with partial hematologic recovery (CR/CRh) within two cycles. At the data cutoff of September 15, 2023, 29 patients were treated: 14 at the 250 μg/500 μg dose and 13 at 500 μg/1000 μg dose. Data from two ineligible patients were excluded. At the end of two cycles, 12 of 14 patients (85.7%) from the 250 μg/500 μg dose achieved CR/CRh of which nine patients (75.0%) were negative for measurable residual disease (MRD; <10-4 leukemic blasts). At the 500 μg/1000 μg dose, 12 of 13 patients (92.3%) achieved CR/CRh; all 12 patients (100.0%) were MRD-negative. No treatment-related grade 4 cytokine release syndrome (CRS) or neurologic events (NEs) were reported. SC injections were well tolerated and all treatment-related grade 3 CRS and NEs responded to standard-of-care management, interruption, or discontinuation. Treatment with SC blinatumomab resulted in high efficacy, with high MRD-negativity rates and acceptable safety profile in heavily pretreated adults with R/R B-ALL.

Transient and fully reversible changes in laboratory parameters and modifications of the cytokine profile during blinatumomab treatment in children with relapsed or refractory B-cell acute lymphoblastic leukemia

We analyzed changes in laboratory parameters, including blood counts, liver enzymes, inflammation and coagulation markers, and cytokines, from 70 blinatumomab-treated pediatric patients (NCT01471782). Overall, trends were consistent in responders and nonresponders. Platelets and lymphocytes peaked on day (D) 10 in cycle 1 and returned to baseline on D42 and D29, respectively. Neutrophils peaked on D2 and returned to baseline on D42. Alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and bilirubin peaked on D17, reversing to baseline on D29; total protein levels were constant. These findings indicate that blinatumomab-induced changes in laboratory parameters were transient, reversible, and not requiring treatment interruptions in responders and nonresponders.

Adaptation to spindle assembly checkpoint inhibition through the selection of specific aneuploidies

Both the presence of an abnormal complement of chromosomes (aneuploidy) and an increased frequency of chromosome missegregation (chromosomal instability) are hallmarks of cancer. Analyses of cancer genome data have identified certain aneuploidy patterns in tumors; however, the bases behind their selection are largely unexplored. By establishing time-resolved long-term adaptation protocols, we found that human cells adapt to persistent spindle assembly checkpoint (SAC) inhibition by acquiring specific chromosome arm gains and losses. Independently adapted populations converge on complex karyotypes, which over time are refined to contain ever smaller chromosomal changes. Of note, the frequencies of chromosome arm gains in adapted cells correlate with those detected in cancers, suggesting that our cellular adaptation approach recapitulates selective traits that dictate the selection of aneuploidies frequently observed across many cancer types. We further engineered specific aneuploidies to determine the genetic basis behind the observed karyotype patterns. These experiments demonstrated that the adapted and engineered aneuploid cell lines limit CIN by extending mitotic duration. Heterozygous deletions of key SAC and APC/C genes recapitulated the rescue phenotypes of the monosomic chromosomes. We conclude that aneuploidy-induced gene dosage imbalances of individual mitotic regulators are sufficient for altering mitotic timing to reduce CIN.

A phase 1b study of blinatumomab with the anti-programmed cell death (PD)-1 antibody AMG 404 in adults with relapsed/refractory (R/R) B-cell precursor acute lymphoblastic leukemia (ALL)

e19003

Background: Preclinical data indicate that anti-PD-1 agents can facilitate activity of bispecific T-cell engager (BiTE) molecules. Here we assess the combination of the anti-CD19 BiTE molecule blinatumomab with the anti-PD-1 antibody AMG 404 in adults with R/R ALL (NCT04524455). Methods: Eligible adults with R/R ALL (Ph+ disease included) received 2-5 treatment cycles. Each cycle was 42 days, consisting of 4 weeks of cIV blinatumomab and a 2-week treatment-free interval as per label. In Cohort 1, AMG 404 was dosed IV at 240 mg every 4 weeks (Q4W); first dose was Day (D) 11 of Cycle (C) 1. Primary endpoints were dose-limiting toxicities (DLTs) and other adverse events (AEs). Results: As of 20 Dec 2021, patients (pts) from Cohort 1 (n=8) had median age of 57 (range: 24-73) y, 6/8 male, 6/8 Caucasian, 1 with extramedullary disease (duodenum), 2 with prior blinatumomab, and a median of 5 (2-15) prior treatment lines. Two pts remain on study and 2 completed the study; 4 pts discontinued the study due to death (n=3) or consent withdrawn (n=1). No DLTs were reported for the 3 evaluable pts. Of the 5 pts not evaluable for DLTs, in C1, 4 had disease progression and 1 an unrelated fatal pneumonia. Treatment-related grade (Gr) ≥3 and/or serious AEs in all 8 pts included cytokine release syndrome (CRS) (1 pt Gr 2, 1 pt Gr 1 and 3), Gr 3 increases in ALT and AST, Gr 3 fever, Gr 3-4 neutropenia, Gr 4 neutropenia/Gr 3-4 thrombocytopenia (same pt), Gr 2 sensorimotor polyneuropathy, Gr 3 hypertension, Gr 3 encephalopathy, and in 1 pt Gr 3-4 decreases in white blood cells, lymphocytes, and neutrophils. One pt developed Gr 3 SARS-COV-2 pneumonia on C2D25, resolving without clinical sequelae. C3 start was delayed by 12 days but protocol treatment resumed uneventfully. All 3 DLT-evaluable pts had a complete response (CR) or CR with partial hematologic recovery (CRh), 2/3 without measurable residual disease (MRD), within 2 cycles; the 3rd pt had an MRD response at the end of C3. Preliminary pharmacokinetic results for the combination of blinatumomab and AMG 404 demonstrated that their exposures were consistent with those observed for each as monotherapy and did not indicate any drug-drug interactions. To date, all samples tested for anti-blinatumomab antibodies have been negative. Conclusions: In this ongoing phase 1b study, the combination of blinatumomab with AMG 404 was tolerated with a manageable safety profile. No DLTs were reported. Enrollment continues in Cohort 2 in which AMG 404 is dosed Q4W at 480 mg starting on C1D1, 48 hours prior to blinatumomab. Clinical trial information: NCT04524455. [Table: see text]

The complete mitochondrial genome of the smudged eighty-eight butterfly Diaethria gabaza eupepla (Salvin & Godman, 1868) (Insecta: Lepidoptera: Nymphalidae)

The smudged eighty-eight butterfly Diaethria gabaza eupepla (Salvin & Godman, 1868) (Nymphalidae) is a vividly colored aposematic butterfly from Central and South America. A complete circular mitochondrial genome (mitogenome) of 15,156 bp from D. gabaza eupepla was assembled from a genome skimming Illumina sequence library. The AT-rich (80.5% AT) mitogenome consists of 13 protein-coding genes, 22 tRNAs, 2 rRNAs, and a control region in the typical butterfly gene order. Diaethria gabaza eupepla COX1 begins with an atypical CGA start codon and ATP6, COX1, COX2, CYTB, ND1, ND4, ND4L, and ND5 mRNAs contain incomplete stop codons completed by the addition of 3' A residues. Phylogenetic reconstruction places Diaethria as the sister clade to Hamadryas within monophyletic nymphalid subfamily Biblidinae, consistent with previous phylogenetic hypotheses.

CD19 expression in pediatric patients with relapsed/refractory B-cell precursor acute lymphoblastic leukemia pre- and post-treatment with blinatumomab

Blinatumomab is a BiTE^® (bispecific T-cell engager) immuno-oncology therapy, which has demonstrated significant activity in patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (R/R B-ALL); however, a subset of patients relapse. Monitoring expression of cluster of differentiation (CD)19 in relapsed patients is critical to inform sequencing of subsequent therapies. The expression of CD19 in 59 pediatric patients with R/R B-ALL was analyzed on the day of diagnosis of R/R B-ALL and on days 15 and 29 of cycle 1 of blinatumomab. Most patients treated with one cycle of blinatumomab retained expression of CD19, and would therefore be eligible for subsequent anti-CD19 CAR T-cell therapy.

Schmerzhafte artifizielle Ekchymosen an Hals und Gesicht

Es wird über den Fall einer 13-jährigen Patientin mit neu aufgetretenen, auf Druck schmerzhaften Hautveränderungen beidseits am Hals und im Gesicht berichtet. Auf Nachfrage traten die Effloreszenzen episodisch im Rahmen von Stresssituationen auf. Im Verlauf kam es zu einer Spontanheilung mit Narbenbildung und mehreren Rezidiven. Nach erfolgter Probebiopsie wurde ein Gardner-Diamond-Syndrom ausgeschlossen und der Verdacht auf selbstinduzierte Hautläsionen geäußert.

[Multiple well demarcated skin erosions and ulcers following exanthematous drug eruption after sultamicillin therapy]

This article presents the case of a patient with newly developed skin erosions and ulcerations following an exanthematous drug eruption due to sultamicillin therapy. The skin lesions were treated topically with clobetasol and prednicarbate and orally with methylprednisolone. A skin smear revealed massive growth of Escherichia coli bacteria. Blood cultures were negative. The cause for developing ecthyma gangrenosum in our patient were iatrogenic immunosuppression and transient bacteremia.

SMAD4 Loss Is Associated with Cetuximab Resistance and Induction of MAPK/JNK Activation in Head and Neck Cancer Cells

Purpose: We previously demonstrated an association between decreased SMAD4 expression and cetuximab resistance in head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to further elucidate the clinical relevance of SMAD4 loss in HNSCC.Experimental Design: SMAD4 expression was assessed by IHC in 130 newly diagnosed and 43 patients with recurrent HNSCC. Correlative statistical analysis with clinicopathologic data was also performed. OncoFinder, a bioinformatics tool, was used to analyze molecular signaling in TCGA tumors with low or high SMAD4 mRNA levels. The role of SMAD4 was investigated by shRNA knockdown and gene reconstitution of HPV-negative HNSCC cell lines in vitro and in vivoResults: Our analysis revealed that SMAD4 loss was associated with an aggressive, HPV-negative, cetuximab-resistant phenotype. We found a signature of prosurvival and antiapoptotic pathways that were commonly dysregulated in SMAD4-low cases derived from TCGA-HNSCC dataset and an independent oral cavity squamous cell carcinoma (OSCC) cohort obtained from GEO. We show that SMAD4 depletion in an HNSCC cell line induces cetuximab resistance and results in worse survival in an orthotopic mouse model in vivo We implicate JNK and MAPK activation as mediators of cetuximab resistance and provide the foundation for the concomitant EGFR and JNK/MAPK inhibition as a potential strategy for overcoming cetuximab resistance in HNSCCs with SMAD4 loss.Conclusions: Our study demonstrates that loss of SMAD4 expression is a signature characterizing the cetuximab-resistant phenotype and suggests that SMAD4 expression may be a determinant of sensitivity/resistance to EGFR/MAPK or EGFR/JNK inhibition in HPV-negative HNSCC tumors. Clin Cancer Res; 23(17); 5162-75. ©2017 AACR.

Abstract 2474: Smad4 loss induces cetuximab resistance and increased metastatic potential in head and neck squamous cell carcinoma

Introduction: Cetuximab is a monoclonal antibody that increases survival in head and neck squamous cell carcinoma (HNSCC) patients when used in combination with radiation or chemotherapy. However, this EGFR targeted-agent only has modest activity when administered as a monotherapy and a majority of patients develop therapeutic resistance. Previous work has established the TGF-beta signaling pathway has a critical role in HNSCC development and progression. Modulation of this pathway, and more specifically loss of Smad4 expression, is a common means of developing drug resistance in many cancers. To determine the role of Smad4 loss in HNSCC development, metastasis, and cetuximab resistance, Smad4 was knocked down or reexpressed in HNSCC cell lines and evaluated in vitro and in vivo.

Methods: Smad4 was knocked-down in SCC61 following stable introduction of Smad4-targeting shRNA. Using stable lentiviral transduction, Smad4 was reexpressed in FaDu, a HNSCC cell line which lacks de novo expression of Smad4. Following modulation, changes in cetuximab sensitivity were determined using Matrigel colony formation assays. The effects of Smad4 modulation on various signal transduction pathways were determined by Western blot analysis with total and phospho-specific antibodies. Changes in metastatic potential were evaluated using an orthotopic in vivo model. The subsequent development of lymph node metastases were monitored utilizing luciferin-based imaging. Key proteins associated with metastasis were also assayed using ELISA and protein antibody arrays.

Results: Smad4 loss increased the growth of SCC61 and FaDu and Smad4 status correlated with cetuximab resistance in both cells. Western blot analysis demonstrated Smad4 loss activates JNK and MAPK signaling. Consequently, co-treatment of Smad4 knockdown cells with cetuximab and a JNK inhibitor reversed the previously observed therapeutic resistance. Smad4 knockdown also increased lymph node metastasis in the orthotopic in vivo model. Protein array analysis determined Smad4 knockdown increased the expression of amphiregulin, FGF2, and VEGF, pathways capable of promoting metastasis. Expression of these Smad4-sensitive targets was inhibited with the use of a MAPK inhibitor.

Conclusion: We determined Smad4 loss enhances cetuximab resistance and in vivo metastasis development in HNSCC. Additionally, JNK and MAPK pathway activation play an important role in mediating this process. Our results suggest Smad4 downregulation plays a critical role for prognosis of HNSCC patients, and JNK and MAPK inhibition may contribute to improve therapeutic outcome of those patients.

Citation Format: Hiroyuki Ozawa, Haixia Cheng, Elana J. Fertig, Jason D. Howard, Ana Markovic, Robert Hughes, Jimena Perez, Harry Quon, Christine H. Chung. Smad4 loss induces cetuximab resistance and increased metastatic potential in head and neck squamous cell carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2474. doi:10.1158/1538-7445.AM2014-2474

Preferential activation of the hedgehog pathway by epigenetic modulations in HPV negative HNSCC identified with meta-pathway analysis

Head and neck squamous cell carcinoma (HNSCC) is largely divided into two groups based on their etiology, human papillomavirus (HPV)-positive and –negative. Global DNA methylation changes are known to drive oncogene and tumor suppressor expression in primary HNSCC of both types. However, significant heterogeneity in DNA methylation within the groups results in different transcriptional profiles and clinical outcomes. We applied a meta-pathway analysis to link gene expression changes to DNA methylation in distinguishing HNSCC subtypes. This approach isolated specific epigenetic changes controlling expression in HPV− HNSCC that distinguish it from HPV+ HNSCC. Analysis of genes identified Hedgehog pathway activation specific to HPV− HNSCC. We confirmed that GLI1, the primary Hedgehog target, showed higher expression in tumors compared to normal samples with HPV− tumors having the highest GLI1 expression, suggesting that increased expression of GLI1 is a potential driver in HPV− HNSCC. Our algorithm for integration of DNA methylation and gene expression can infer biologically significant molecular pathways that may be exploited as therapeutics targets. Our results suggest that therapeutics targeting the Hedgehog pathway may be of benefit in HPV− HNSCC. Similar integrative analysis of high-throughput coupled DNA methylation and expression datasets may yield novel insights into deregulated pathways in other cancers.

Current role of EGF receptor monoclonal antibodies and tyrosine kinase inhibitors in the management of head and neck squamous cell carcinoma

New agents and treatment strategies that can be safely and effectively integrated into current treatment paradigms for head and neck squamous cell carcinoma (HNSCC) are urgently needed. To date, the anti-EGF receptor (EGFR) monoclonal antibody, cetuximab, is the first and only molecularly targeted therapy to demonstrate a survival benefit for patients with recurrent or metastatic disease. Other anti-EGFR-targeted therapies, including monoclonal antibodies (e.g., panitumumab and zalutumumab) and reversible and irreversible ErbB family tyrosine kinase inhibitors (e.g., lapatinib, afatinib and dacomitinib) are being actively investigated in Phase II and Phase III clinical trials. In addition, validated biomarkers are needed to predict clinical benefit and resistance to anti-EGFR therapy in HNSCC. This review will compare and contrast the mechanisms of action of anti-EGFR monoclonal antibodies and tyrosine kinase inhibitors and also discuss their role in the management of HNSCC and the potential impact of human papillomavirus status in the development of these targeted agents.

Nuclear epidermal growth factor receptor and p16 expression in head and neck squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

Epidermal growth factor receptor (EGFR) and p16 (a surrogate marker of human papillomavirus [HPV] infection) expression are strong prognostic factors in patients with head and neck squamous cell carcinoma (HNSCC).

STUDY DESIGN

We examined expression levels of total and nuclear EGFR as well as p16 status based on evidence that nuclear EGFR may have a role in DNA damage repair.

METHODS

An HPV-negative (SQ20B) and an HPV-positive (UMSCC47) HNSCC cell line were examined for EGFR and γH2AX expression. A tissue microarray containing 123 cores obtained from 101 HNSCC tumors was analyzed for EGFR expression by automated quantitative analysis and p16 expression by immunohistochemical staining, and these results were correlated with available clinical data.

RESULTS

SQ20B had higher EGFR expression than UMSCC47. Nuclear localization of EGFR on activation with transforming growth factor-α was observed in SQ20B, but not in UMSCC47. SQ20B also had increased γH2AX foci compared to UMSCC47, suggesting that SQ20B has more DNA damage compared to UMSCC47. Total and nuclear EGFR was reliably obtained from 80 of 101 patients. p16 levels were determined in 87 of 101 patients. p16 levels were strongly associated with the oropharyngeal subsite and poorly differentiated histology. Expression of total and nuclear EGFR was higher in p16-negative tumors compared to p16-positive tumors (Wilcoxon rank test, P = .038 and P = .014, respectively).

CONCLUSIONS

Further studies are required to determine a mechanistic link between these two prognostic factors and the significance of EGFR localization to nucleus in DNA damage repair pathway activation.

Regulation of HIF-1α signaling and chemoresistance in acute lymphocytic leukemia under hypoxic conditions of the bone marrow microenvironment

Overcoming resistance to chemotherapy is the main therapeutic challenge in the treatment of acute lymphocytic leukemia (ALL). Interactions between leukemia cells and the microenvironment promote leukemia cell survival and confer resistance to chemotherapy. Hypoxia is an integral component of bone marrow (BM) microenvironment. Hypoxia-inducible factor-1α (HIF-1), a key regulator of the cellular response to hypoxia, regulates cell growth and metabolic adaptation to hypoxia. HIF-1α expression, analyzed by Reverse Phase Protein Arrays in 92 specimens from newly diagnosed patients with pre-B-ALL, had a negative prognostic impact on survival (p = 0.0025). Inhibition of HIF-1α expression by locked mRNA antagonist (LNA) promoted chemosensitivity under hypoxic conditions, while pharmacological or genetic stabilization of HIF-1α under normoxia inhibited cell growth and reduced apoptosis induction by chemotherapeutic agents. Co-culture of pre-B ALL or REH cells with BM-derived mesenchymal stem cells (MSC) under hypoxia resulted in further induction of HIF-1α protein and acquisition of the glycolytic phenotype, in part via stroma-induced AKT/mTOR signaling. mTOR blockade with everolimus reduced HIF-1α expression, diminished glucose uptake and glycolytic rate and partially restored the chemosensitivity of ALL cells under hypoxia/stroma co-cultures. Hence, mTOR inhibition or blockade of HIF-1α-mediated signaling may play an important role in chemosensitization of ALL cells under hypoxic conditions of the BM microenvironment.

An Evaluation of European Countries' Health Systems through Distance Based Analysis

INTRODUCTION

The issue of evaluating the efficiency of health systems has been elaborated upon frequently. Since "health" is a multi-faceted concept, many variables of different measurement units must be included in its analysis; consequently, this presents a great obstacle for researchers to overcome.

MATERIALS AND METHODS

A novel statistical approach for evaluating the efficiency of organizational units is here proposed, which can also be easily applied to the health sector. For these purposes, the health status of the 27 countries belonging to the European Union has been examined by employing a statistical Ivanovic-Jeremic Distance Based Analysis (DBA) on various health indicators.

RESULTS

The subsequent outcome of the Distance Based Analysis has shown that Cyprus and Ireland have a most efficient health system sectors. Greece also has exceptional indicators of health service, yet health on the individual level is not comparable.

LIMITATIONS

Since it synthesizes many variables into an efficiency score, a DBA can be easily applied to other regions/countries. However, the choice of input and output variables can be considered to be potential limitations since a different choice of variables may cause different efficiency scores for the countries selected.

CONCLUSIONS

A DBA approach contributes significantly to the efficiency in the field of research measurement. This analysis can be additionally performed alongside DEA and SFA methods, as a new measure of efficiency.

Induction of vascular endothelial growth factor secretion by childhood acute lymphoblastic leukemia cells via the FLT-3 signaling pathway

Human leukemia cells secrete VEGF, which can act in a paracrine manner within the bone marrow microenvironment to promote leukemia cell survival and proliferation. The FLT-3 receptor tyrosine kinase plays an essential role in regulating normal hematopoiesis, but its constitutive activation via mutation in acute leukemias is generally associated with poor outcome. The aim of this study was to investigate interactions between the FLT-3 and VEGF signaling pathways in acute leukemia using cell lines and ex vivo cultures of pediatric acute lymphoblastic leukemia cells following expansion of direct patient explants in immunodeficient mice. Different xenograft lines exhibited variable cell surface FLT-3 expression, as well as basal and FLT-3 ligand-induced VEGF secretion, whereas the MV4;11 cell line, which expresses constitutively active FLT-3, secreted high levels of VEGF. The FLT-3 inhibitor, SU11657, significantly reduced VEGF secretion in three of six xenograft lines and MV4;11 cells, in conjunction with inhibition of FLT-3 tyrosine phosphorylation. Moreover, exposure of xenograft cells to the FLT-3-blocking antibody, D43, also reduced VEGF secretion to basal levels and decreased FLT-3 tyrosine phosphorylation. In terms of downstream signaling, SU11657 and D43 both caused dephosphorylation of extracellular signal-regulated kinase 1/2, with no changes in AKT or STAT5 phosphorylation. Finally, partial knockdown of FLT-3 expression by short interfering RNA also resulted in inhibition of VEGF secretion. These results indicate that FLT-3 signaling plays a central role in the regulation of VEGF secretion and that inhibition of the FLT-3/VEGF pathway may disrupt paracrine signaling between leukemia cells and the bone marrow microenvironment.

Effectiveness of dexamethasone and low-power laser in minimizing oedema after third molar surgery: a clinical trial

Postoperative oedema is common following removal of impacted lower third molars. Several types of drug therapy (corticosteroids, non-steroidal anti-inflammatory drugs, enzymes) have been tried. The aim of this study was to compare the effectiveness of low-power laser (LPL) and dexamethasone after surgical removal of impacted lower third molars under local anaesthesia (2% lidocaine/epinephrine).

MATERIAL AND METHODS

There were 120 healthy patients divided into four groups of 30 each. Group 1 received LPL irradiation immediately after operation (energy output 4 J/cm2 with constant power density of 50 mW, wavelength 637 nm); group 2 also received i.m. injection of 4 mg dexamethasone (Dexason) into the internal pterygoid muscle; group 3 received LPL irradiation supplemented by systemic dexamethasone (Dexason), 4 mg i.m. in the deltoid region, followed by 4 mg of dexamethasone intraorally 6h postoperatively; and the fourth (control) group received only the usual postoperative recommendations (cold packs, soft diet, etc.).

RESULTS

LPL irradiation with local use of dexamethasone (group 2) resulted in a statistically significant reduction of postoperative oedema in comparison to the other groups. No adverse effects of the procedure or medication were observed.

CONCLUSION

LPL irradiation after lower third molar surgery can be recommended to minimize swelling. The effect is enhanced by simultaneous local intramuscular use of dexamethasone.

FLT-3: a new focus in the understanding of acute leukemia

The FMS-like tyrosine kinase-3 (FLT-3), which belongs to the class III receptor tyrosine kinase family, is primarily expressed by hematopoietic cells and plays an important role in hematopoiesis. FLT-3 is also expressed in the majority of acute leukemias, in which the presence of FLT-3 activating mutations is associated with poor prognosis. Consequently, there has been a recent surge in the development of FLT-3 inhibitors for the molecular targeting of leukemia, and many of these are now in clinical trials. An improved understanding of how FLT-3 interacts with its ligand, as well as how FLT-3 activating mutations are able to trigger downstream intracellular signaling pathways, will provide greater insight to how small molecule inhibitors may best be utilized and combined with established chemotherapeutic drugs for the management of patients with high-risk acute leukemia.

[Medical aspects of adolescent sexuality]

The increase of sexual activity among the adolescents has become a danger to their reproductive health. The goal of this study was to explore sexual behaviour of young people, to establish risks that endanger their reproductive health, and to find out the ways to reduce the consequences of adolescent sexuality. The study was conducted in the Mother and Child Health Care Institute of Serbia over a 2-year period. The sexual and reproductive behaviour, attitudes toward sexuality and contraception, as well as the prevalence rates of unintended pregnancy and Chlamydia trachomatis genital infections were analyzed in 300 sexually active adolescent females, aged 19 years. The first sexual intercourse was in 16.9 years, in average. Less than one-third of the total number (31.3%) of these persons had contraceptive protection at the first intercourse; condom was most frequently used (28.3%). Motives for the initiation of sexual activity were: love (45.7%), curiosity (35.7%), physical attraction and passion (8.3%), peer pressure (5.0%), on the boyfriend's insistence (4.7%), need for love (0.3%) and without answer (0.3%). Two-thirds of adolescent females (63.7%) reported more than one partner, 21.7% more than three and 10.2% more than five sexual partners. Almost half of girls (40.7%) experienced sexual intercourse in casual acquaintance, and 10.3% with a 10 or more years older partner. Use of contraceptive methods during each sexual encounter was inconsistent and sporadic. More than half of adolescent females (54.3%) relied on traditional forms of contraception, like withdrawal of the phallus. Condom was the method of contraceptive choice in one-third (34.3%) of girls, "birth-control pill" in 10.7% and spermicides in 0.7% of subjects. With a new sexual partner condom was used regularly by 55.6% of adolescents; and the remaining percentage of girls used condom irregularly (24.7%), or never (19.7%). The time interval between the initiation of sexual activity and the first gynaecological examination was more than 6 months in 56.7% of cases, and from one to three years in 31.0% of tested adolescent females. The reasons for the first gynaecological visit were as follows: fear of getting pregnant (22.0%), suspicion of contracting a sexually transmitted disease (22.0%) and symptoms indicating a pelvic inflammatory disease (18.3%). Only one-third of girls (37.7%) had their first gynaecological examination as a regular control examination or to get some contraceptive advice. During the adolescence unwanted pregnancy was noted in 16.0% of examined girls. One legal abortion had 14.4% of girls, two 1.3% and three 0.3% of adolescent females. Chlamydia trachomatis genital infection was found in 30.3% of girls. In the girls' opinion the improved knowledge about sexuality, reproduction and contraception is the best way of popularizing contraception among youth. This could be done by introduction of sexual education in school programmes (51.0%) or through mass media (33.3%). A successful health care service for young people should include: a gynaecologist who will have enough time and patience for an adolescent patient (91.3%); a female gynaecologist (36.7%); and a kind other health care workers (21.3%). In order to increase the number of adolescents who will use a condom, the following measures are necessary: a better quality of condoms (54.0%), installation of condom machines (15.6%), mass media education programmes on the significance of the condom role in the prevention of sexually transmitted diseases (10.0%), attractive design of condoms (7.0%), free condoms (6.7%), and universal accessibility of condoms (1.0%). The reproductive health of adolescent girls in Belgrade has been endangered by: their sexual behaviour, poor acceptance of healthy life styles, lack of responsibility in sexual relationships and high prevalence rates of unintended pregnancy and sexually transmitted diseases. Improvement of adolescent reproductive health could be achieved by: educational programmes for adolescents about sexuality, reproduction and contraception; appropriate adolescent advisory health care services; and a better condom quality.

Double modulation of 5-fluorouracil by leucovorin and low-dose methotrexate in advanced colorectal cancer

A phase II study was carried out to evaluate the efficacy and toxicity of a double biochemical modulation of 5-fluorouracil (5-FU) by methotrexate (MTX) and leucovorin (LV) in patients with advanced unresectable colorectal cancer. Forty-two patients with measurable metastases of colorectal cancer were treated with 5-FU in daily doses of 600 mg/m2 given in a 6-hour intravenous (i.v.) infusion on days 1-5, LV 50 mg/m2 i.v. on days 2,3 and 5, and MTX 40 mg/m2 i.v. on days 1 and 4, every 4 weeks. Twenty-eight patients had a single metastatic site, eleven double, whereas three had more than two metastatic sites. Objective response (one complete response) was observed in 12 of 40 patients (30%) (95% confidence interval 16-48), stable disease in 19 patients (47%) and progression in 9 patients (23%). Overall median survival was 12 months. Median time to progression was 6 months. Treatment was generally well tolerated. The most frequent adverse reactions were stomatitis (38%), nausea and vomiting (35%), diarrhea (31%), leukopenia (18%), and plantar-palmar erythroderma (15%). The combination of 5-FU, LV and MTX seems to be an active regimen in advanced colorectal cancer.

Immunohistochemical demonstration of mitochondria in routinely processed tissue using a monoclonal antibody

We report results obtained using the monoclonal antibody M-II 68, which recognizes inner mitochondrial membrane in routinely processed (formalin-fixed and paraffin-embedded) tissue by light microscopic immunohistochemistry. In ten normal brains, the range of immunoreactivity in various cell types and locations was defined. The most intense staining was observed in Purkinje cells, in neurons of cranial nerve nuclei, pons and substantia nigra, as well as in choroid plexus epithelial cells. By comparison with this control group, one case of primary mitochondrial encephalomyopathy exhibited increased staining of endothelial and vascular smooth muscle cells, choroid plexus epithelial cells, and neurons of various locations. Scattered ragged-red fibres were heavily labelled in one case of mitochondrial myopathy, while ten muscles without mitochondriopathy were left unstained. Our method is able to detect accumulations of mitochondria and increases in mitochondrial cristae density. It could prove useful for differential diagnosis of routine biopsy material and for clarification of cell types involved in mitochondrial cytopathies.