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.     

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.     

New developments in flow cytometric analyses of lymphocyte markers.

This article addresses several fundamental features of clinical flow cytometry. A practical overview of the technical and methodologic aspects of this fast-growing and increasingly important new clinical and investigative field is provided. The use of flow cytometry for the diagnosis and monitoring of various chronic lymphoproliferative diseases also is discussed. This article may serve as a useful guide to those seeking to set up or maintain a clinical flow cytometry laboratory.     

Increased expression of CD152 (CTLA-4) by normal T lymphocytes in untreated patients with B-cell chronic lymphocytic leukemia.

Patients with chronic lymphocytic leukemia (CLL) have defects in both cellular and humoral immunity. Since CD152 (CTLA-4) plays a critical role in downregulating T-cell responses, we studied the expression of surface and cytoplasmic CD152 (sCD152 and cCD152, respectively) in freshly isolated T cells from treatment-na?ve patients with CLL. CD4+ and CD8+ T cells from these patients demonstrated significantly increased sCD152 and cCD152 compared to normal donors. Furthermore, these patients had an increased proportion of the regulatory CD4(+)/CD25(+)/CD152+ subset that correlated with advanced Rai stage, unfavorable cytogenetics and low serum IgG and IgA levels. The expression of sCD152 by T cells also correlated with ZAP-70 expression by CLL B cells. The proportion of CD4(+)/CD25+ cells was also correlated with unmutated immunoglobulin heavy chain variable gene status. Blockade of CD152 with monoclonal antibody (mAb) in proliferation assays was associated with potent T-cell proliferation in response to autologous and allogeneic CD40-activated CLL B cells. In summary, T cells from patients with CLL may be primed for anergy by expressing increased amounts of CD152; anti-CD152 mAb may represent a therapeutic opportunity to enhance an immune response against autologous leukemia cells.