Bone age and growth in fetal alcohol syndrome

We have found delayed mean bone age in 63 children with fetal alcohol syndrome (FAS). The mean bone age Z-score for boys (n = 31) was -2.12 SDs and for girls (n = 32) was -1.62 SDs. This might suggest that they have potential for catch-up growth. However, experience with children with intrauterine growth retardation suggests that this will not be the case and that FAS children will be of reduced height at maturity. Further support for this assumption was gained from a sample of 26 patients who were followed until at least the age of 14 years for females and 16 years for males. There was no significant change in height Z-scores from early childhood to early adulthood, the mean score being -2.16 SDs and -2.11 SDs at mean ages of 4.83 years and 18.69 years, respectively. On the other hand, there were significant changes in weight and head circumference. The mean weight Z-score changed from -2.10 SDs to -1.14 SDs (p < 0.001). The head circumference mean Z-score in 16 patients was -3.13 SDs at a mean age of 2.79 years and -2.63 SDs at a mean age of 17.37 years (p = 0.013). Short stature can continue to be used as a diagnostic criterion for FAS beyond childhood.     

Role of sodium and potassium ions in regulation of glucose metabolism in cultured astroglia

Effects of increasing extracellular K+ or intracellular Na+ concentrations on glucose metabolism in cultures of rat astroglia and neurons were examined. Cells were incubated in bicarbonate buffer, pH 7.2, containing 2 mM glucose, tracer amounts of [14C]deoxyglucose ([14C]dGlc), and 5.4, 28, or 56 mM KCl for 10, 15, or 30 min, and then for 5 min in [14C]dGlc-free buffer to allow efflux of unmetabolized [14C]dGlc. Cells were then digested and assayed for labeled products, which were shown to consist of 96-98% [14C]deoxyglucose 6-phosphate. Increased K+ concentrations significantly raised [14C]deoxyglucose 6-phosphate accumulation in both neuronal and mixed neuronal-astroglial cultures at 15 and 30 min but did not raise it in astroglial cultures. Veratridine (75 microM), which opens voltage-dependent Na+ channels, significantly raised rates of [14C]dGlc phosphorylation in astroglial cultures (+20%), and these elevations were blocked by either 1 mM ouabain, a specific inhibitor of Na+,K(+)-ATPase (EC 3.6.1.37), or 10 microM tetrodotoxin, which blocks Na+ channels. The carboxylic sodium ionophore, monensin (10 microM), more than doubled [14C]dGlc phosphorylation; this effect was only partially blocked by ouabain and unaffected by tetrodotoxin. L-Glutamate (500 microM) also stimulated [14C]dGlc phosphorylation in astroglia--not through N-methyl-D-aspartate or non-N-methyl-D-aspartate receptor mechanisms but via a Na(+)-dependent glutamate-uptake system. These results indicate that increased uptake of Na+ can stimulate energy metabolism in astroglial cells.     

Practical model fitting approaches to the direct extraction of NMR parameters simultaneously from all dimensions of multidimensional NMR spectra

A maximum likelihood (ML)-based approach has been established for the direct extraction of NMR parameters (e.g., frequency, amplitude, phase, and decay rate) simultaneously from all dimensions of a D-dimensional NMR spectrum. The approach, referred to here as HTFD-ML (hybrid time frequency domain maximum likelihood), constructs a time-domain model composed of a sum of exponentially-decaying sinusoidal signals. The apodized Fourier transform of this time-domain signal is a model spectrum that represents the 'best-fit' to the equivalent frequency-domain data spectrum. The desired amplitude and frequency parameters can be extracted directly from the signal model constructed by the HTFD-ML algorithm. The HTFD-ML approach presented here, as embodied in the software package CHIFIT, is designed to meet the challenges posed by model fitting of D-dimensional NMR data sets, where each consists of many data points (10(8) is not uncommon) encoding information about numerous signals (up to 10(5) for a protein of moderate size) that exhibit spectral overlap. The suitability of the approach is demonstrated by its application to the concerted analysis of a series of ten 2D 1H-15N HSQC experiments measuring 15N T1 relaxation. In addition to demonstrating the practicality of performing maximum likelihood analysis on large, multidimensional NMR spectra, the results demonstrate that this parametric model-fitting approach provides more accurate amplitude and frequency estimates than those obtained from conventional peak-based analysis of the FT spectrum. The improved performance of the model fitting approach derives from its ability to take into account the simultaneous contributions of all signals in a crowded spectral region (deconvolution) as well as to incorporate prior knowledge in constructing models to fit the data.     

Case of the month: May 1997--a 31 year old woman with seizures, fatigue and attention deficits

A 31-year-old woman with a five year history of seizures complained of worsening fatigue and attention deficits. At age 26, neuroradiological imaging studies had shown a small, non-enhancing hypodense lesion involving the left frontobasal and subcallosal region. Follow-up CT and MRI images showed that the lesion had not changed. A stereotactic biopsy showed a dysembryoplastic neuroepithelial tumor (DNT). The lesion was subtotally resected and the diagnosis of DNT was fully confirmed. However, the distinction between oligodendroglioma, ganglioglioma, focal dysplastic cerebral cortex, and DNT was only possible with knowledge of the clinical and neuroradiological data.     

Stress increases the population of splenic macrophages, permissive for Langat virus, in mice

Cytogenetic study conducted after a single intraperitoneal injection of cyclophosphane in doses of 10, 20, and 40 mg/kg showed in 1.5-2-month-old male mice that the level of bone marrow cells damaged by the mutagen was significantly higher in NZW animals than in C57Bl/6 animals. The ability to produce active oxygen forms in response to addition of opsonized zymosan and phorbol myristate acetate was also higher in bone marrow suspensions of NZW mice. The higher sensitivity of NZW animals to pro-oxidant and clastogenic effects may be related to the genetically determined decrease of antioxidant protection in NZW animals.     

Process safety management of a fuel gas conditioning facility using fault tree analysis

This paper discusses a process hazard management study of a fuel gas conditioning facility based on stateof-the-art fault tree analysis techniques. This facility lowers the water and hydrocarbon dewpoints of a high pressure fuel gas exposed to frigid temperatures during distribution. Using hazards checklists and guidelines as well as internal reviews, various process hazards were identified for this facility. Computerized fault tree analysis techniques were used to identify the failure sequences which could lead to process hazards, and analysts used these results to evaluate the impact of specific hazards upon process safety. Through recommendations presented in the study, the facility owner gained an increased awareness of potential problems and made modifications to reduce the possibility of a hazardous condition and subsequent catastrophic failure.     

Unusual immunocytochemical and ultrastructural features of synovial fluid cells in multicentric reticulohistiocytosis. A case report

We present the first report in which cells in synovial fluid from a patient with multicentric reticulohistiocytosis (MRH) were studied by immunocytochemistry for correlation with routine light and electron microscopy. MRH cells stained predominantly for lymphocyte-related surface antigens and not for the monocyte marker LEU M3 (CD14). These findings suggest a lymphocytic origin of MRH cells and not a histiocytic origin, as previously suggested. In addition, large numbers of membrane-bound, electron-dense, secretory-type granules were found ultrastructurally in the cytoplasm of these cells.