The clinical relevance of t(14; 18)/BCL-2 rearrangement and DEL 6q in diffuse large cell lymphoma and immunoblastic lymphoma

Background: t(14; 18)/bcl-2 gene rearrangement (R) is claimedto impart a worse rate of complete remission and disease-freesurvival in diffuse large cell lymphoma (DLCL). DEL 6q has alsobeen associated with poor outcome. Design: Retrospective studyof 54 patients with either diffuse large cell or immunoblasticlymphoma who had cytogenetics and/or molecular studies performed.Results: Patient characteristics, complete remission rate, andtime to treatment failure (TTF) were similar at three year follow-upfor groups with and without t(14; 18)/BCL-2R Survival was worsefor the former but the difference was not statistically significant.For DEL 6q, patient characteristics and survival rates weresimilar at three year follow-up for patients with and withoutthe abnormality. TTF was worse for the former but this was notstatistically significant. Conclusion: This study, with equalor greater number of patients with t(14; 18) than previous reports,fails to show a worse prognosis for patients with the t(14;18) chromosomal abnormality. A definite association will awaitfurther accrual of patients and a meaningul multivariate analysis. lymphoma, BCL-2, cytogenetics, DEL 6q     

Intracranial circulation: pulse-sequence considerations in three- dimensional (volume) MR angiography

The technique and feasibility of magnetic resonance (MR) angiography of intracranial vessels were studied in 35 healthy volunteers. Variations in image orientation, repetition time (TR), and flip angle were evaluated to determine their effects on flow-related enhancement. Gradient modifications--including echo time (TE), motion compensation, bandwidth, and field of view--were also studied in an effort to reduce motion-induced phase shifts. Results indicated that a FISP (fast imaging with steady precession) sequence with a TR of 50 msec, TE of 15 msec, velocity compensation in the read and section-select directions, acceleration compensation in the read direction, anisotropic volume, and a 1.25-mm partition thickness produced three-dimensional angiographic MR images that were accurate and reproducible in the depiction of the major intracranial vessels. Difficulties with field of view, persistent signal void secondary to higher-order motion, and spatial resolution remain major problems requiring additional study.     

Becoming an intentional teacher

This series of articles, Managing Your Academic Career, presents ways to intentionally improve your teaching. This first article explains the concept of becoming an intention teacher. Subsequent articles will deal with strategies that are useful in clinical teaching, such as preparing students to value and use research in practice, and providing feedback to students in the clinical setting.     

Poisoning with oxybutynin.

A case of poisoning with 100 mg of oxybutynin in a 34-year-old female is reported. The main features were anticholinergic effects, including stupor, followed by disorientation and agitation on awakening, dilated pupils, dry skin and retention of urine. She had a sinus tachycardia which resolved 3 h after admission, and in addition ventricular ectopics and bigeminy which continued for a further 30 h. She recovered fully on symptomatic treatment alone.     

Paediatric dacryocystorhinostomy

Of 258 cases of dacryocystorhinostomy performed on children in the period September 1981 to September 1991, 130 were for simple, unresolved congenital nasolacrimal duct obstruction. Other indications for surgery included punctal agenesis, lacrimal fistula, post-traumatic and post-inflammatory canalicular obstruction. Of 177 children without canalicular pathology, 171 (96%) were relieved of symptoms with one operation, without canalicular intubation. Of 81 cases with canalicular disease, 55 of 70 (79%) who underwent DCR plus canalicular intubation, and 10 of 11 who underwent DCR plus Lester-Jones tube, were substantially improved with one operation. No child required peroperative or postoperative blood transfusion. Dacryocystorhinostomy in childhood, in experienced surgical hands, is a safe procedure, achieving relief of symptoms in most cases, particularly in the absence of canalicular disease.     

Growth kinetics of microscopic hepatocellular neoplasms in carcinogen-resistant and carcinogen-responsive strains of mice.

The initiation and growth of microscopic hepatocellular neoplasms in C57BL/6 mice, considered relatively resistant to hepatocarcinogenesis, was compared with that of the more responsive C3H and B6C3F1 (C57BL/6 x C3H) strains. Tumors were induced by giving male mice injections of diethylnitrosamine when they were 15 days old. During the first 18 weeks postinjection, the growth rates of neoplasms in the three strains were almost identical (doubling time of 2.1 to 2.5 weeks). However, after that time, only the growth rates of the C57BL/6 neoplasms slowed; between 30 and 42 weeks the doubling time had increased to 13 weeks. In addition, at all sacrifice times the number of neoplasms in the C3H strain was at least 2.5 times higher than in the C57BL/6 and B6C3F1 strains. These results suggest that the genetic determinant(s) for inhibited tumor growth (expressed only in C57BL/6 mice) are recessive to those for unimpeded tumor growth (expressed in C3H and B6C3F1 mice), while the determinant(s) for large numbers of tumors (expressed only in C3H mice) are recessive to those for small numbers of tumors (expressed in C57BL/6 and B6C3F1 mice). In addition to the interstrain differences in tumor growth, two other types of tumor growth heterogeneity were identified. First, in each of the three strains, the largest tumors were found to grow faster than the smaller tumors. This suggests that the very broad range in tumor size that is seen in this model results from the long-term differences in the growth rates of individual neoplasms. Second, we found that in microscopic hepatic neoplasms in B6C3F1 mice, the thymidine labeling indices were 2.3 times greater in the outer 50-microns shell (2 cells thick) than in the next deeper 50-micron layer cells. This suggests that even in these minute neoplasms, gradients in blood-borne oxygen, nutrients, or growth factors are responsible for heterogeneous growth.