Effects of embryo reduction from trichorionic triplets to twins

Sixty-six trichorionic triplet pregnancies reduced to twins were compared with 47 triplet pregnancies that were not reduced. The miscarriage rate was higher (7.6% compared with 2.6%) but the number delivering between 24 and 32 weeks was lower (8.2% compared with 24.0%). Since severe preterm delivery is associated with risks of neonatal death and severe handicap, embryo reduction of triplets to twins may not improve the chance of survival but may reduce the rate of handicap.     

Arterial oxygen saturation profiles in healthy preterm infants

AIM: To construct a reference range of SpO2 values in healthy preterm infants using a simple data logging device. METHODS: Thirty three healthy preterm infants were monitored for a continuous period of 4 hours at rest using an Ohmeda Biox 3700 E Pulse Oximeter and an electronic data logger (Rustrack Ranger). Stored data were downloaded and saved as individual files on a personal computer. RESULTS: The study group median and 5th and 95th percentiles were used to construct a cumulative frequency curve of time against SpO2 value, representing the normal reference range of SpO2 profiles in healthy preterm infants. CONCLUSION: Comparison of an infant's SpO2 profile against this curve may be more helpful in guiding supplemental oxygen treatment in that individual than a figure for a mean SPO2 and its standard deviation.     

Design and performance analysis of adaptive optical telescopesusing lasing guide stars

The use of adaptive optical systems using electrically deformable mirrors to compensate for turbulence effects is discussed. Since these systems require bright reference sources adjacent to the object of interest and can be used only to observe the brightest stars, artificial guide stars suitable for controlling an adaptive imaging system must be created in the upper atmosphere by using a laser to excite either Rayleigh backscattering in the stratosphere or resonance backscattering in the mesospheric sodium layer. The design requirements of a laser-guided adaptive telescope, as well as the expected imaging performance, are discussed in detail. It is shown that a 2-m ground-based laser-guided telescope can achieve imaging performance levels at visible wavelengths nearly matching the theoretical imaging performance of the Hubble Space Telescope (HST). The required lasers can be either bought off the shelf or built with current technology. The laser power requirement for the Rayleigh guide star approach is on the order of 82 W for zenith viewing when the atmospheric seeing cell diameter is 20 cm. For the same conditions the laser power requirement for the Na guide star approach is on the order of 14 W. Both systems will achieve near diffraction limited imaging with a Strehl ratio of ~0.67 and an angular resolution of approximately 0.07 arcsec for an observation wavelength of 0.5 μm     

Father's effect on infant birth weight

OBJECTIVE: We sought to determine whether paternal size at birth and during young adulthood influences the birth weight of the offspring. STUDY DESIGN: This historic cohort study followed up girls born in Copenhagen during 1959 to 1961. Their pregnancies in 1974 to 1989 were traced through the Danish Population Register, and the Personal Identification Numbers of the fathers of the children were obtained. Paternal birth weight was obtained from midwifery records and adult stature from military draft records. RESULTS: Compared with fathers who weighed at least 4 kg at birth, fathers who weighed 3 to 3.99 kg at birth had infants who were 109 gm lighter, and fathers who weighed <3 kg had infants who were 176 gm lighter after adjustment for maternal birth weight and adult stature, smoking, and medical and socioeconomic factors. After adjustment, fathers in the lowest quartile of adult body mass index had infants that were 105 gm lighter than those of fathers in the highest quartile. Both paternal birth weight and adult body mass index exhibited significant trends in association with infant birth weight. CONCLUSION: Independently of maternal size, the father's physical stature, particularly his own size at birth, influences the birth weight of his children.     

Multiple-coupled microstrip hairpin-resonator filter

This letter presents the design of six-resonator multiple-coupled microstrip filter. A low-pass prototype of six-resonator multiple-coupled filter is developed first based on the conventional Chebyshev filter. The characteristics of attenuation poles located on both sides of the frequency response are described. According to the low-pass prototype, the design of a six-resonator multiple-coupled microstrip hairpin filter at 6 GHz is completed with the aid of EM simulation. The experimental results are demonstrated and discussed.     

Resistance-modifying agents. 5. Synthesis and biological properties of quinazolinone inhibitors of the DNA repair enzyme poly(ADP-ribose) polymerase (PARP)

Clinical studies concerning the role of poly(ADP-ribose) polymerase (PARP) in the repair of drug- and radiation-induced DNA damage have been impeded by the poor solubility, lack of potency, and limited specificity of currently available inhibitors. A series of 2-alkyl- and 2-aryl-substituted 8-hydroxy-, 8-methoxy-, and 8-methylquinazolin-4(3H)-ones has been synthesized and evaluated for PARP inhibitory activity in permeabilized L1210 murine leukemia cells. 8-Methoxy- and 8-methylquinazolinones (14-34) were readily prepared by acylation of 3-substituted anthranilamides with the appropriate acid chloride, followed by base-catalyzed cyclization. The requisite 8-hydroxyquinazolinones (6, 35-39) were synthesized by demethylation of the corresponding 8-methoxyquinazolinones with BBr3. N-Methylation of 8-methoxy-2-methylquinazolinone (15) with MeI, followed by O-demethylation by BBr3, afforded the control N3-methylquinazolinones 42 and 43, respectively. In general, an 8-hydroxy or 8-methyl substituent enhanced inhibitory activity in comparison with an 8-methoxy group. 2-Phenylquinazolinones were marginally less potent than the corresponding 2-methylquinazolinones, but the introduction of an electron-withdrawing or electron-donating 4'-substituent on the 2-aryl ring invariably increased potency. This was particularly evident in the 8-methylquinazolinone series (IC50 values 0.13-0.27 microM), which are among the most potent PARP inhibitors reported to date. N3-Methylquinazolinones 42 and 43 were essentially devoid of activity (IC50 values > 100 microM). In studies with L1210 cells in vitro, a concentration of 200 microM 8-hydroxy-2-methylquinazolinone (6, NU1025) (IC50 value 0.40 microM) potentiated the cytotoxicity of the monomethylating agent 5-(3-methyltriazen-1-yl)imidazole-4-carboxamide and gamma-radiation 3.5- and 1.4-fold, respectively, at the 10% survival level.