A safety and feasibility study of the use of 670 nm red light in premature neonates.

OBJECTIVE: Retinopathy of prematurity (ROP) is a vasoproliferative disorder of the retina affecting extremely preterm or low birth weight infants The aim of this study was to assess the feasibility and safety of 670 nm red light use in a neonatal intensive care unit. STUDY DESIGN: Neonates <30 weeks gestation and <1150 g were enrolled within 48 h of birth. Data collected included cause of preterm delivery, Apgar scores and birthweight. 670 nm red light was administered for 15 min per day from a distance of 25 cm, delivering 9 J cm(-)(2), from the time of inclusion in the study until 34 weeks postmenstrual age. Infants were assessed daily for the presence of any skin burns or other adverse signs. RESULT: Twenty-eight neonates were enrolled, seven 24 to 26 weeks and twenty-one 27 to 29 weeks gestation. The most common cause for preterm delivery was preterm labor (14/28) with five of these having evidence of chorioamnionitis. There were no skin burns or other documented adverse events. Entry into the study was readily achieved and treatment was well accepted by parents and nursing staff. CONCLUSION: 670 nm red light appears to be a safe and feasible treatment for further research in respect to ROP.

Modifications to a commercially available linear mass spectrometer for mass-resolved microscopy with the pixel imaging mass spectrometry (PImMS) camera.

RATIONALE: Imaging mass spectrometry is a powerful analytical technique capable of accessing a large volume of spatially resolved, chemical data from two-dimensional samples. Probing the entire surface of a sample simultaneously requires a detector with high spatial and temporal resolutions, and the ability to observe events relating to different mass-to-charge ratios. METHODS: A commercially available time-of-flight mass spectrometer, designed for matrix-assisted laser desorption/ionization (MALDI) analysis, was combined with the novel pixel imaging mass spectrometry (PImMS) camera in order to perform multi-mass, microscope-mode imaging experiments. A number of minor modifications were made to the spectrometer hardware and ion optics so that spatial imaging was achieved for a number of small molecules. RESULTS: It was shown that a peak width of Δm50 % < 1 m/z unit across the range 200 ≤ m/z ≤ 800 can be obtained while also achieving an optimum spatial resolution of 25 µm. It was further shown that these data were obtained simultaneously for all analytes present without the need to scan the experimental parameters. CONCLUSIONS: This work demonstrates the capability of multi-mass, microscope-mode imaging to reduce the acquisition time of spatially distributed analytes such as multi-arrays or biological tissue sections. It also shows that such an instrument can be commissioned by effecting relatively minor modifications to a conventional commercial machine.

Comparative study of four noise spectra as potential tinnitus maskers.

Ten experienced tinnitus-masker uses compared four widely different noise bands as potential maskers in a laboratory environment. No reliable individual preferences could be found, and most of the noises were acceptable to most of the subjects. A wide-band noise was marginally most frequently preferred. In this sample, there was no indication that individual tailoring of the frequency spectra of tinnitus maskers is required to achieve acceptable masking. Subjects also underwent tests of hearing, tinnitus matching and tinnitus masking. Most subjects chose noise levels for therapeutic masking that only partially masked their tinnitus. This suggests prescription or trial of tinnitus maskers even for patients who have high minimal masking levels.

Analysis of urinary organic acids by Plasmaspray liquid chromatography/mass spectrometry.

High-performance liquid chromatography is being used increasingly as a screening method to detect organic acid-urias, an important group of inherited metabolic disorders. Analysis is hampered by lack of a suitable specific detection system. We have carried out preliminary investigations to assess the potential value of liquid chromatography/mass spectrometry with a plasmaspray interface. Spectra of standard acids yielded intense [M-H]- ions with little fragmentation. Organic acids could not be identified in urine samples from healthy neonates because of poor sensitivity. However, urine from a baby with the inherited disorder methylmalonic aciduria showed a distinct peak of methylmalonic acid, easily identified owing to its high sample concentration.

Selected reaction monitoring during gas chromatography/mass spectrometry of eicosanoids.

Gas chromatography/electron capture negative ion mass spectrometry of eicosanoids, as pentafluorobenzyl (PFB) ester, methyl oxime (where applicable), trimethylsilyl (TMS) ether derivatives, is reported using a double-focusing instrument of trisector configuration. Sub-picogram detection limits were observed for prostaglandins E1, E2 and F2 alpha during selected ion monitoring (SIM) of [M-PFB]- ions. Selected reaction monitoring (SRM) of [M-PFB]-----[M-PFB-TMSOH]-, occurring in the first field-free region, was of modest sensitivity, reflecting the stability of the [M-PFB]- ions. The leukotriene B4 (LTB4) derivative was successfully analyzed by SIM at the low-picogram level. In this instance, the fragmentation [M-PFB]-----[M-PFB-TMSOH] occurred in high yield in the first field-free region. The advantageous improvement in selectivity of detection that may be achieved with SRM was evident during the analysis of a serum extract for LTB4.

Auditory word discrimination in male children diagnosed as having minimal brain dysfunction.

Investigated auditory word discrimination skill in children diagnosed as having minimal brain dysfunction (MBD), a heretofore unexplored topic in the study of MBD. A lack of auditory discrimination skill seems relevant to learning deficiency in language acquisition, a typical sign of MBD. The present study tested the hypothesis that phonemic aural discriminations would be difficult to make for boys diagnosed as having MBD. Errors and nonresponses made while Ss performed an extended auditory word discrimination task were compared between a group of 26 boys diagnosed as having MBD and a matched normal group. As expected, the MBD group had a significantly higher error rate than the normal group even when Ss were discriminating easy word pairs composed of dissimilar items (e.g., reading, math). These and other results suggested that the MBD group was very susceptible to fatigue even while motivated to perform well and while able to improve with practice. The relatively inferior performance of the MBD group was interpreted as resulting directly from a lack of auditory discrimination skill and indirectly from fatigue and its accompanying attention loss.