Methodologic problems in clonogenic assays of spontaneous human tumors

Summary Colony formation in soft agar was used to investigate growth properties and drug sensitivity in 102 tumor specimens from 91 patients. Sufficient colony growth for sensitivity testing with various drugs was obtained in 36 of 67 specimens (54%) with adequate cell yield and pathologically documented malignancy. Room temperature (20–24° C) is superior to both 4° C and 37° C for 12–36 h storage and transport of malignant effusions. By contrast, fine mincing in sterile saline or balanced salt solution, and refrigerated storage (4° C) appear optimal in experiments with three solid tumors. The use of buffered NH₄Cl to lyse red blood cells markedly reduced plating efficiencies, and also reduced the percentage of tumors in which drug sensitivities could be tested from 64% to 38%. Several combinations of potential growth factors and culture media have been tested. Insulin enhanced plating efficiency (PE) in all six adenocarcinomas tested. Drug sensitivity of tumors was not affected by varying plating efficiency up to five-fold in two tumors. In eleven cases tumor cells were exposed to combinations of two or more drugs, and results assessed for evidence of drug interactions. In almost all cases, these two-drug combinations produced additive cell killing rather than either antagonistic or greater-than-additive effects.     

Primary Mediastinal La0rge B-Cell Lymphoma: A Single-Center Study of Clinicopathologic Characteristics

Primary mediastinal large B-cell lymphoma (PMLBCL) is a subset of LBCL with unique clinicopathologic features. Some studies have raised the question of differences in biological features and clinical course among patients from different parts of the world. We conducted a retrospective clinicopathologic analysis of 24 patients with PMLBCL from a single center in Croatia. We also conducted the first investigation of the frequency of lymphotropic viruses human herpesvirus 6 (HHV-6) and HHV-8 in lymphoid lesions of this disease. The clinical characteristics of the patients were as expected, with high International Prognostic Index scores, elevated serum lactate dehydrogenase (LDH) levels, and bulky disease being adverse prognostic factors. Only 6 patients (25%) showed CD30 expression, and Bcl-6 protein expression was, in our series, prognostically favorable (P = .0401). One patient's tumor had detectable HHV-6 genome sequence, but no HHV-8 sequences were detected in any tumors. Two thirds of the patients received CHOP chemotherapy (cyclophosphamide, hydroxydaunomycin, vincristine, and prednisone) with a relatively low complete remission rate (43.8%; median follow-up, 33.8 months). This study confirmed the moderate preponderance among PMLBCL patients of young females with B symptoms and elevated LDH levels. The CHOP regimen proved effective as first-line therapy only in patients with limited disease. Therefore, other third-generation chemotherapy protocols may be considered for treatment, especially in patients with bulky and advanced disease.     

Endovascular repair of a ruptured descending thoracic aortic aneurysm

Endovascular aneurysm repair has considerable potential advantages over the surgical approach as a treatment for thoracic aortic rupture, in part because open surgical repair of ruptured thoracic aortic aneurysms is associated with high mortality and morbidity rates. We describe the successful endovascular deployment of stent-grafts to repair a contained rupture of a descending thoracic aortic aneurysm in an 86-year-old man whose comorbidities prohibited surgery. Two months after the procedure, magnetic resonance angiography showed a patent stent-graft, a patent left subclavian artery, and complete exclusion of the aneurysm.     

Regional activation of chromosomal arm 7q with and without gene amplification in taxane-selected human ovarian cancer cell lines

Taxanes are important drugs in the treatment of ovarian and other cancers, but their efficacy is limited by intrinsic and acquired drug resistance. Expression of the multidrug transporter P-glycoprotein, encoded by the MDR1 (ABCB1) gene, is one of the causes of clinical drug resistance to taxanes. To study the mechanisms of MDR1 activation related to taxanes, we established 11 multidrug-resistant variants from six ovarian cancer cell lines by continuous exposure to either paclitaxel or docetaxel. We profiled gene expression and gene copy number alterations in these cell lines using cDNA microarrays and identified a cluster of genes coactivated with MDR1 in 7q21.11-13. Regional activation was evident in nine resistant variants displaying a coexpression pattern of up to 22 genes over an 8-Mb area, including SRI, MGC4175, CLDN12, CROT, and CDK6. In six of these variants, regional activation was driven by gene copy number alterations, with low-level gains or high-level amplifications spanning the involved region. However, three variants displayed regional increases in gene expression even without concomitant gene copy number changes. These results suggest that regional gene activation may be a fundamental mechanism for acquired drug resistance, with or without changes in gene dosage. In addition to numerical and structural chromosomal changes driven by genome instability in cancer cells, other mechanisms might be involved in MDR1 regional activation, such as chromatin remodeling and DNA or histone modifications of the 7q21 region.     

Minor head trauma and isolated unilateral internuclear ophthalmoplegia

Internuclear ophthalmoplegia is a syndrome that develops due to a lesion of the medial longitudinal fasciculus. This lesion is mostly caused by multiple sclerosis (usually bilaterally), and only rarely by head injury. A case is presented of unilateral internuclear ophthalmoplegia as an isolated sequel of minor head trauma, which eventually resolved. A 40-year-old woman with isolated internuclear ophthalmoplegia secondary to closed head trauma with anatomical lesions of the mesencephalon in the region of medial longitudinal fasciculus is described. A minor contusion was detected by magnetic resonance imaging. Diplopia resolved in 5 months. In conclusion, internuclear ophthalmoplegia should be considered in the differential diagnosis in patients with recent head injuries showing adduction impairment. The connection between the clinical picture and anatomical lesions is visualized by magnetic resonance imaging.     

The role of patient compliance in the management of glaucoma

AIM: The aim of the study was to evaluate patient cooperation in glaucoma treatment. METHODS: We evaluated data collected by an anonymous questionnare from 98 glaucoma patients who answered 6 questions regarding their compliance and persistence in glaucoma treatment. RESULTS: Study results revealed 50% of patients to fail taking their antiglaucoma therapy regularly. Patients on monotherapy showed better compliance and higher level of satisfaction with treatment than those on combination antiglaucoma therapy consisting of 2 or 3 eyedrops. Discontinuation of persistence was recorded in 31% of patients, whereas 51% of patients did not present for control visits every six months as suggested by their ophthalmologist. CONCLUSION: Patients are more compliant and persistent with antiglaucoma monotherapy than with combined therapy. Greater compliance and persistence with ocular hypotensive therapy may improve the outcomes in glaucoma.