Using a sister chromatid differentiation technique, cell cycle study of stimulated lymphocytes of B-cell chronic lymphocytic leukemia (B-CLL) revealed their cell cycle progression to be similar to that of normal lymphocytes stimulated by T-cell and various polyclonal B-cell activators (PBA). The chromosome constitutions of stimulated lymphocytes in 62 patients with B-CLL were examined using PBA such as Epstein-Barr virus (EBV) and lipopolysaccharide W from E. coli 055:B5 (LPS). Of the 20 patients with abnormal clones, 11 patients had trisomy 12; other less common abnormalities were trisomy 1, 6q-, i(7q), 14q+, trisomy 16, trisomy 18, reciprocal translocations, and marker chromosomes of unknown origin. These findings indicate that trisomy 12 may be a unique and common karyotypic change in B-CLL. The fact that 3 out of 4 patients with marker chromosomes showed stage IV disease may indicate that a clone with a marker is a predictor of an unfavourable prognosis. The near correlation between trisomy 12 and kappa chains existed (0.05 less than p less than 0.10). Trisomy 12 was seen in all 5 patients with monoclonal paraprotein.

Aged↗

PubMedDate not supplied

Human platelet spreading on substrata of known surface chemistry.

Using platelet-rich plasma freshly obtained by plasmapheresis, the spread areas of human platelets settled onto substrata of different surface energies were measured to evaluate the hypothesis that initial platelet spreading response is surface dependent. At 37 degrees C, minimal platelet spread areas were found on substrata with critical surface tension between 20 and 30 mN/m (dynes/cm), and increased spreading and morphologic changes occurred on substrata of both higher and lower critical surface tension. This differential response was absent at 25 degrees C. Therefore, measurement of spread platelet area at physiologic temperature rather than number of attached cells is proposed as a superior method of estimating apparent blood compatibility of new biomaterials.

Biocompatible Materials↗

PubMedDate not supplied

Errors in quantitative dynamic three-dimensional keyhole MR imaging of the breast.

Three-dimensional (3D) keyhole magnetic resonance (MR) imaging has been proposed as a means of providing dynamic monitoring of contrast agent uptake by breast lesions, with complete breast coverage and high spatial and temporal resolution. The 3D keyhole technique dynamically samples the central regions of k-space in both phase-encoding directions and provides high-frequency data from a precontrast acquisition. Errors due to data truncation with two-dimensional and 3D region-of-interest measurements are estimated from a numerical simulation of various implementations of the 3D keyhole technique. Errors were found to increase with increasing temporal resolution and reduced object size. Errors of 75% are possible for objects with a diameter approaching 1 pixel when a 3D keyhole implementation that samples 50% of phase-encoding data in each direction is used. Preliminary clinical images with this approach illustrate artifacts consistent with inadequate k-space sampling.

Artifacts↗

PubMedDate not supplied

Atrioventricular block in a toxic child: do not forget diphtheria.

We describe a 4.5-year-old girl who presented with severe febrile throat infection and who, after a few days, developed ventricular tachycardia followed by atrioventricular block. Although a pacemaker was inserted, she died of cardiogenic shock. Throat cultures were positive for Corynebacterium diphtheriae.

Child, Preschool↗

PubMedDate not supplied

Noninvasive external pacing in the newborn.

Complete atrioventricular block in the newborn occasionally requires emergency intervention when the heart rate is too low to provide adequate cardiac output. While medications are frequently ineffective, emergent implantation of a pacemaker is not always feasible and carries a significant morbidity. We report two cases of complete atrioventricular block in newborns treated immediately after birth with an external noninvasive pacemaker system.

Cardiac Pacing, Artificial↗

PubMedDate not supplied

Fluorimetric quantification of cell death in monolayer cultures and cell suspensions.

A fluorimetric assay using ethidium bromide (EB) was employed to quantify cell death in monolayer cell cultures (MA-104 cells) in situ and isolated cell suspensions (isolated colonic cells and Leishmania). Fluorescence of EB stained cells was measured with a photometer coupled to an inverted microscope for cell monolayers or in a spectrofluorometer for cell suspensions. Dead cells stained with trypan blue were fluorescent with EB in all preparations studied, but the latter gave an unequivocal signal. Staining with EB and fluorescein diacetate was mutually exclusive. The relationship between the number of EB fluorescent cells and the intensity of fluorescence measured in the microphotometer was linear for a large range of cell numbers (1-14000) from different types of preparations. Applicability of the method for measuring living and dead cells in two different time scales (minutes and hours) is shown using MA-104 cell monolayers infected with rotavirus and Leishmania suspensions treated with amphotericin B. The method is fast, simple, sensitive and reliable, enabling quantification of living and dead cells in monolayers and suspensions.

Animals↗

PubMedDate not supplied

Does the Beck Anxiety Inventory measure anything beyond panic attack symptoms?

The Beck Anxiety Inventory (BAI) has become a popular measure in anxiety assessment and the BAI does not overlap in content with measures of depression. There is also some factor analytic evidence to support this distinction. However, an inspection of the BAI's content indicates that many of its items resemble, or are identical to, the symptoms of panic attacks listed in the DSM-IV. Further empirical support for this suspicion is provided from the results of a factor analysis of the BAI items and the individual DSM-IV panic symptoms contained in the Panic Attack Questionnaire, using data from a sample of 157 panic disorder patients. A three-factor model (dizziness related, catastrophic cognitions/fear, cardiorespiratory distress) emerged that replicated a three-factor model of panic symptoms identified in earlier work with another panic disorder sample. All but one of the BAI items loaded highly on the three panic symptom clusters and no separate BAI factor was obtained. The BAI appears to be confounded with, or actually measures, panic attacks rather than anxiety in general. Several implications of this finding are discussed.

Adult↗