Relationship between the parameters cellular differentiation,doubling time and platinum accumulation and cisplatin sensitivity in a panel of head and neck cancer cell lines

Patients with head and neck squamous cell carcinoma (HNSCC) treated with cisplatin show a large inter-individual variation in tumor response. Little is known about factors that contribute to this variation. The aim of our study was to correlate the sensitivity to cisplatin with a number of cellular parameters using a panel of 10 human HNSCC cell lines. A 7-fold variation in response after 72 hr of exposure to cisplatin as determined in a colorimetric proliferation assay was observed. The IC₅₀ values did not correlate with the DNA index, the cellular doubling time or the expression of differentiation markers. Intracellular platinum (Pt) concentrations were measured by atomic absorption spectroscopy after exposing the cells to 10 μM cisplatin for 1-72 hr. The intracellular Pt levels increased up to 24 hr. One cell line, derived from the tumor of a patient previously treated with radiotherapy, accumulated much more Pt than the other cell lines. For these other cell lines, a significant positive correlation was found between Pt accumulation and sensitivity. In conclusion, cisplatin-induced growth inhibition in HNSCC in vitro is generally positively correlated with cellular Pt levels. However, the fact that occasionally cancer cells can survive despite high intracellular Pt levels indicates that additional parameters are needed to explain a response unequivocally. Int. J. Cancer 71:410-415, 1997. © 1997 Wiley-Liss Inc.     

Identification of 16 sulfamidase gene mutations including the common R74C in patients with mucopolysaccharidosis type IIIA (Sanfilippo A)

Mucopolysaccharidosis type IIIA (MPS IIIA or Sanfilippo A disease) is a storage disorder caused by deficiency of the lysosomal enzyme sulfamidase. Mutation screening, using SSCP/heteroduplex analyses on cDNA and genomic DNA fragments, was performed in a group of 42 European patients. Sixteen of the 17 different gene mutations characterized have not been previously described. The spectrum of gene lesions consists of two 1-bp deletions (1091delC, 1093delG), an 18-bp duplication (421ins18), a splice site mutation (IVS2-2A→G), and 13 different missense point mutations. As in other lysosomal storage disorders, the phenotypic heterogeneity is associated with a considerable genetic heterogeneity. The missense mutation R74C, which alters an evolutionary conserved amino acid in the active site of the enzyme, was found on 56% of alleles of 16 Polish patients, whereas it was less frequent among German patients (21% of disease alleles). R245H, a previously reported common mutation, represents 35% of disease alleles in German patients, but only 3% in Polish patients. As the combined frequency of the common mutations (R74C and R245H) in German and Polish populations exceeds 55%, screening for these two mutations will assist molecular genetic diagnosis of MPS IIIA and allow heterozygote testing in these populations. Hum Mutat 10:479–485, 1997. © 1997 Wiley-Liss, Inc.     

Glucocerebrosidase genotype of Gaucher patients in The Netherlands: Limitations in prognostic value

Gaucher disease is a recessively inherited lysosomal storage disorder that is caused by a deficiency in glucocerebrosidase activity. The clinical expression is markedly heterogeneous with respect to age of onset, progression, severity, and neurological involvement. The relative incidence of glucocerebrosidase (GC) mutations has been studied extensively for Jewish but not for non-Jewish Caucasian patient populations. The present survey on mutant GC genotypes prevalent in Gaucher disease in The Netherlands was taken of 72 patients from different genetic backgrounds. This number is more than half the total number of affected Gaucher patients to be expected on the basis of the incidence of the disorder in this country. Analysis of nine GC mutations led to the identification of 74% of the mutant GC alleles in patients from 44 unrelated Dutch families (i.e., families that have lived in The Netherlands for at least several generations) and of 44% of the mutant GC alleles in patients from nine unrelated families that recently immigrated from both European and non-European countries. The N370S (cDNA 1226G) GC mutation proved to occur most frequently (41%) in the unrelated Dutch patients and less frequently (6%) in the unrelated immigrant patients and was always associated with the nonneuronopathic (Type 1) form of the disease. Apart from the association of the N370S mutation with Type 1 Gaucher disease, the prognostic value of GC genotyping was limited, since a particular GC genotype did not correlate closely to a specific clinical course, or to a specific relative responsiveness to enzyme-supplementation therapy. Hum Mutat 10:348–358, 1997. © 1997 Wiley-Liss, Inc.     

Denaturation of type II collagen in articular cartilage in experimental murine arthritis. Evidence for collagen degradation in both reversible and irreversible cartilage damage

Degradation of type II collagen is thought to be a key step in the destruction of articular cartilage in patients with rheumatoid arthritis or osteoarthritis. The aim of this study was to investigate whether type II collagen degradation is associated with cartilage destruction. Type II collagen degradation was studied in two murine arthritis models, zymosan-induced arthritis (ZIA), which develops reversible articular cartilage damage based on proteoglycan analysis, and antigen-induced arthritis (AIA), in which there is irreversible damage to the cartilage. Type II collagen degradation was assayed immunohistochemically using the COL2-3/4m antibody which recognizes denatured type II collagen, such as is produced by collagenase cleavage. In both models, degradation of type II collagen was observed in the non-calcified articular cartilage of arthritic but not of control knees. In the patella-femoral compartment, collagen denaturation started to increase on day 3 (ZIA) and day 7 (AIA) and remained high on day 14. In contrast, in the tibia-femoral compartment, type II collagen breakdown was not increased before 14 days in either model. By 28 days, collagen denaturation was strongly reduced in the patella-femoral compartment in the ZIA model, but persisted in the tibia-femoral compartment in both models. In conclusion, increased type II collagen degradation was found in articular cartilage of both ZIA and AIA animals. Since ZIA does not develop irreversible cartilage destruction, this indicates that cartilage may have the ability to withstand a limited degree of type II collagen degradation without developing irreversible damage. Copyright © 1999 John Wiley & Sons, Ltd.     

Executive Attention and Empathy-Related Responses in Boys with Oppositional Defiant Disorder or Conduct Disorder,With and Without Comorbid Anxiety Disorder

This is a first study that investigated the relationships between executive attention—as an important aspect of emotion regulation—and state empathy and sympathy in ODD/CD boys with (N?=?31) and without (N?=?18) comorbid anxiety disorder (7–12 years). Empathic reactions were evoked using three sadness-inducing film clips. One clip was highly evocative involving a bear cub losing his mother, whilst two other clips were mildly evocative involving children in common childhood situations. Self-reports of empathy and sympathy were collected and executive attention was assessed with a performance task. Poor executive attention skills were associated with less empathy and sympathy, particularly in ODD/CD boys with anxiety and under conditions of a highly evocative stimulus. Our findings support the view that different mechanisms may be involved in empathy problems of ODD/CD children.     

Recovery from chemotherapy-induced white matter changes in young breast cancer survivors?

In a previous longitudinal diffusion tensor imaging (DTI) study, we observed cerebral white matter (WM) alterations (reduced fractional anisotropy (FA)) related to decreased cognitive performance 3–5 months after chemotherapy-treatment (t2) when compared to baseline (t1) (Deprez et al. in Journal of Clinical Oncology: Official Journal of the American Society of Clinical Oncology, 30(3), 274–281. doi:10.1200/JCO.2011.36.8571, 2012). The current study investigates the evolution and the nature of these previously observed microstructural changes. Twenty-five young women with early-stage breast cancer who received chemotherapy treatment (C+), 14 who did not receive chemotherapy (C-) and 15 healthy controls (HC) previously studied, underwent reassessment 3–4 years after treatment (t3). We assessed (1) longitudinal changes of cognitive performance and FA and (2) cross-sectional group differences in myelin-water-imaging and multishell diffusion MRI metrics at t3. MRI metrics were assessed on a voxel-by-voxel basis and in regions-of-interest (ROI) in which previous WM injury was detected. Longitudinal results: Mixed-effects modeling revealed significant group-time interactions for verbal memory and processing speed (p < 0.05) reflecting regained performance in the C+ group at t3. Furthermore, in chemotherapy-treated patients, FA returned to baseline levels at t3 in all ROIs (p < 0.002), whereas no FA changes were seen in controls. Additionally, FA increase from t2 to t3 correlated with time since treatment in two of the four regions (r = 0.40, p < 0.05). Cross-sectional results: Advanced diffusion MRI and myelin-water imaging metrics in the ROIs did not differ between groups. Similarly, no whole-brain voxelwise differences were detected. Initial WM alterations and reduced cognitive performance following chemotherapy-treatment were found to recover in a group of young breast cancer survivors three to four years after treatment.