Flow-cytometric analysis of reticulocytes in normal cord blood

We performed precise reticulocyte counts and a reticulocyte maturation study according to ribosomal RNA (rRNA) content, in normal cord blood. For this purpose we analyzed 35 cord blood specimens corresponding to a mean gestational age of 39.2 weeks (range 38-41). In all specimens complete blood counts were performed with the H*1 (Technicon, Bayer) analyzer. Reticulocyte maturation study and counts were conducted by the R-1000 (Sysmex) reticulocyte analyzer. We obtained the following measurements (mean +/- 1 SD): reticulocyte percentage 3.11 +/- 0.75% and reticulocyte absolute count 137.3 +/- 33.3 x 10(9)/l. There was no correlation between the reticulocyte counts and the duration of gestation or the type of labor (normal, forceps assisted or cesarean section). Reticulocyte subpopulations with different rRNA content and maturation were expressed as reticulocytes with high (HFR), median (MFR) and low (LFR) fluorescence of the fluorochrome auramine bound to rRNA. Normal cord values were: HFR% = 13.6 +/- 2.4, MFR% = 22.5 +/- 2.4 and LFR% = 63.9 +/- 4.3. Reference maturation subpopulations were assessed for comparison in 180 samples of healthy adults (90 males and 90 females) and were found HFR% = 1.0 +/- 0.8, MFR% = 9.7 +/- 3.3 and LFR% = 89.2 +/- 3.4. The HFR% and MFR% were significantly higher while LFR% was significantly lower (p < 0.001) in cord compared to adult blood, denoting a shift to more immature reticulocyte forms. The above values are provided as normal reference data of the reticulocyte maturation profile in full-term cord blood.     

Single-laser approach for fluorescence guidance of excimer laser angioplasty at 308 nm: evaluation in vitro and during coronary angioplasty

BACKGROUND AND OBJECTIVE: Spectroscopic guidance of laser angioplasty has been attempted using a diagnostic He-Cd laser in addition to the therapeutic laser system. This study evaluated a single-laser approach for simultaneous ablation and fluorescence excitation. STUDY DESIGN/MATERIALS AND METHODS: A spectroscopy system was coupled to a clinical XeCl excimer laser. Ablation of 162 human aortic samples in saline and blood with 45 mJ/mm2 per pulse yielded 676 fluorescence spectra validated histologically. The same equipment was used in 16 patients for angioplasty of 18 coronary stenoses applying 500 to 1,725 pulses with 45 to 60 mJ/mm2 under saline flushing. A total of 783 spectra were recorded and validated by intracoronary ultrasound (categories: atheroma, fibrous plaque, calcified lesion). RESULTS: In vitro, 5 types of spectra could be differentiated: (1) atheroma, (2) fibrous plaque, (3) calcified lesion in saline, (4) media, and (5) calcified lesion in blood. Discriminant analysis prospectively classified 576 validation spectra with the following sensitivity and specificity for each type: (1) 83.5 and 97.1%, (2) 85.7 and 96.8% (3) 100 and 98.5%, (4) 98.1 and 99.3%, (5) 98.9 and 100%, respectively. In vivo type 1, 2, 3, and 5 spectra were also observed, but not the media spectrum. The predominant sonographic category also prevailed in spectroscopy. Calcified lesions yielded type 3 and 5 as well as mixed spectra. CONCLUSIONS: Using an excimer laser for angioplasty allows combining ablation and fluorescence excitation without a diagnostic laser. Principal types of atherosclerotic lesions and the media can be differentiated spectroscopically with this approach.     

Thyrotropin-receptor-mediated diseases: a paradigm for receptor autoimmunity

Autoantibodies to the thyrotropin receptor (TSHR) can act as thyrotropin agonists or antagonists, or can cause thyroid hypertrophy. Neither the autoantibody-binding sites on the TSHR nor the intracellular mechanisms by which the autoantibodies mediate their diverse functional effects are completely understood. This article reviews how cloning of the TSHR has contributed to our understanding of its structure and function, and has allowed induction of experimental autoimmunity to the TSHR.     

Production of enterotoxins by Bacteroids fragilis strains--effect of clindamycin

Four B. fragilis strains were examined: one nonenterotoxigenic (NTBF) and three producing enterotoxin (ETBF). The growth of cultures was determined and enterotoxin, which is released to the culture medium during growth of strains, was detected. BHI broth and BHI broth with addition of subinhibitory doses (sub-MIC) of clindamycin were applied. Bacterial cultures were incubated at 37 degrees C for 48 hours. After 4, 8, 16, 24, 48 hours of cultivation, samples of bacterial cultures were collected and the optical density was measured. Then the samples were centrifuged, supernatants were filtered through 0.45 micron filters and concentrated three times with 5000 D ultrafilters. Prepared samples were kept frozen at -70 degrees C until used. The titre of enterotoxin in samples was determined on human colon adenocarcinoma cell line HT 29/C1. Neutralization assay was performed with culture filtrates, which were enterotoxin-positive and with rabbit anti-enterotoxin serum. The results of the experiments indicate that enterotoxin is detected after 16 hours of incubation of ETBF strains. Clindamycin at subinhibitory concentrations (sub-MIC) inhibits the growth of B. fragilis cultures. The antibiotic causes also delay and decrease in enterotoxin production by ETBF strains.     

T-cell-dependent pathways in rheumatoid arthritis

In rats carbaryl undergoes extensive biotransformation involving both albumin-mediated hydrolysis and cytochrome P-450-mediated metabolism; studies have suggested that approximately one-half of a carbaryl dose is hydrolysed and one-half is metabolized. Fluosol is known to be an inducer of cytochrome P-450, and Fluosol haemodilution reduces plasma albumin concentrations. The disposition of carbaryl was, therefore, determined in rats for 72 h after 40 mL kg-1 haemodilution with Fluosol or normal saline (0.9% NaCl). Volumes of distribution were significantly reduced after saline haemodilution for 72 h but only at 48 h after Fluosol haemodilution. Fluosol and saline haemodilution had little influence on carbaryl total body clearance (CL). These results indicate that both hepatic and non-hepatic clearance pathways were not influenced by the haemodiluents or the haemodilution procedure.     

The reality of living in passive solar homes: A user-experience study

This paper presents a study of a user-experience survey about living in passive solar homes. It was carried out at the Energy Park located in the western part of Milton Keynes. The survey focuses on the reality of living in passive solar homes as perceived or experienced by the occupant. It is hoped that the findings would come to bear on strategic passive solar design decisions that would address the improvement of the well-being of the occupant.. The survey is aimed at assessing user satisfaction with the overall performance of their homes as well as a study of some of the problems that are believed to be common in passive solar housing.Results from the survey seem to indicate that the majority of those who buy passive solar homes are motivated to do so by a desire for thermal comfort at low cost. The building aesthetics is the second most important factor, showing that passive solar home lovers are also conscious of the quality of the architectural design. The overall performance of passive solar homes in this study, with regard to thermal and visual comfort, seems to be generally satisfactory. Statistical analysis showed some significant association between some important environmental design parameters.     

Comparison of voice analysis systems for perturbation measurement

Dysphonic voices are often analyzed using automated voice analysis software. However, the reliability of acoustic measures obtained from these programs remains unknown, particularly when they are applied to pathological voices. This study compared perturbation measures from CSpeech, Computerized Speech Laboratory, SoundScope, and a hand marking voice analysis system. Sustained vowels from 29 male and 21 female speakers with mild to severe dysphonia were digitized, and fundamental frequency (F0), jitter, shimmer, and harmonics- or signal-to-noise ratios were computed. Commercially available acoustical analysis programs agreed well, but not perfectly, in their measures of F0. Measures of perturbation in the various analysis packages use different algorithms, provide results in different units, and often yield values for voices that violate the assumption of quasi-periodicity. As a result, poor rank order correlations between programs using similar measures of perturbation were noted. Because measures of aperiodicity apparently cannot be reliably applied to voices that are even mildly aperiodic, we question their utility in quantifying vocal quality, especially in pathological voices.