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Biomedical subjects

Thomas R Moore

Publications and source records attributed to Thomas R Moore.

7 recordsLinked to original sources
PubMed2004

The dynamics and tuning of orchestral crotales.

An experimental and theoretical investigation of the acoustic and vibrational properties of orchestral crotales within the range C6 to C8 is reported. Interferograms of the acoustically important modes of vibration are presented and the frequencies are reported. It is shown that the acoustic spectra of crotales are not predicted by assuming that they are either thin circular plates or annular plates clamped at the center, despite the physical resemblance to these objects. Results from finite element analysis are presented that demonstrate how changing the size of the central mass affects the tuning of the instruments, and it is concluded that crotales are not currently designed to ensure optimal tuning. The possibility of using annular plates as crotales is also investigated and the physical parameters for such a set of instruments are presented.

Computer Simulation↗
PubMed2002

A comparison of amniotic fluid fetal pulmonary phospholipids in normal and diabetic pregnancy.

OBJECTIVE: Our purpose was to determine whether there are differences in the timing of the appearance of various amniotic fluid fetal pulmonary phospholipids in normal and diabetic pregnancy. STUDY DESIGN: A case-control study of 295 subjects with diabetes and 590 control subjects was performed by use of gestational age-matched amniocentesis specimens analyzed for lecithin/sphingomyelin (L/S) ratio, phosphatidylinositol (PI), and phosphatidylglycerol (PG) composition. Diabetic subjects were stratified according to type of diabetes, degree of blood glucose control, and birth percentile of the neonate. RESULTS: There was no difference in L/S ratios over gestational age by type of diabetes or quality of glycemic control. Women with preexisting diabetes had significantly higher PI levels at 33 to 35 weeks' gestation, which became similar to levels of control subjects after 36 weeks, whereas patients with gestational diabetes mellitus and control subjects had similar PI levels throughout. In diabetic subjects, the onset of production of PG was delayed from 35.9 +/- 1.1 weeks (controls) to 38.7 +/- 0.9 weeks (overt diabetics) and 37.3 +/- 1.0 weeks for gestational diabetes mellitus (P <.001). The delay in PG synthesis was not related to infant sex, level of maternal glucose control, or fetal macrosomia. CONCLUSIONS: Fetal pulmonary maturation, as evidenced by the onset of PG production in the amniotic fluid, is delayed in diabetic pregnancy by 1 to 1.5 weeks. This delay appears to be associated with an early and sustained elevation in amniotic fluid PI levels at 32 to 34 weeks.

Amniocentesis↗
PubMed2002

Preterm premature rupture of membranes: vascular endothelial growth factor and its association with histologic chorioamnionitis.

OBJECTIVE: We hypothesize that vascular endothelial growth factor, a known angiogenic and permeability factor that is locally expressed in fetal membranes and decidua, may be the primary regulator in the pathway that eventually leads to preterm premature rupture of membranes. Our objective was to test the hypothesis that, both in the presence and in the absence of histologic chorioamnionitis, there is an increased expression of the vascular endothelial growth factor gene and its receptor Flt-1 in the human fetal membranes. STUDY DESIGN: Membranes were sampled from a region that was distinct as the rupture site from three groups of patients with preterm premature rupture of membranes. Groups 1 and 2 differed only in the length of the latency period from rupture of the membranes to delivery. Group 3 included preterm patients with intact membranes, who acted as control subjects. All patients who were selected for the study lacked clinical signs of chorioamnionitis and were delivered by cesarean delivery. Tissue samples were analyzed for interleukin-6 gene expression by Northern blot analysis and for the presence of interleukin-6 protein by immunocytochemistry. The expression of vascular endothelial growth factor and Flt-1 genes was analyzed by in situ hybridization. RESULTS: All tissue samples from group 1 and five tissue samples from group 2 (designated as group 2A) showed expression of the interleukin-6 gene and the presence of interleukin-6 protein in the fetal membranes (P <.001) and were therefore identified as inflamed. Five tissue samples from the patients in group 2 (designated as group 2B) and all control tissue samples showed neither evidence of interleukin-6 gene expression nor the presence of its protein and therefore were identified as not inflamed. Vascular endothelial growth factor and Flt-1 gene expression were increased significantly in the fetal membrane and decidua samples that were obtained from the noninflamed tissues from group 2B (P <.005) yet showed further enhancement in expression in the inflamed tissues. CONCLUSION: The expression patterns of vascular endothelial growth factor and Flt-1 genes are indicative of a molecular pathologic condition of fetal membranes, regardless of their inflammatory status, which suggests their role as a primary regulator of preterm premature rupture of membranes.

Adolescent↗
PubMedDate not supplied

Maternal floor infarction of the placenta: association with central nervous system injury and adverse neurodevelopmental outcome.

OBJECTIVE: To compare cranial ultrasound studies and neurodevelopmental outcome of preterm infants affected by maternal floor infarction (MFI) of the placenta to gestational age-matched controls over an 8-year period from a single institution. STUDY DESIGN: Retrospective case/control study. RESULTS: Compared to gestational age-matched controls, infants born to mothers with MFI had a higher incidence of CNS injury on neonatal cranial ultrasound examinations and at follow-up were more likely to have a suspicious or abnormal neurologic examination. MFI cases had lower developmental scores in all areas tested and were more likely to have neurodevelopmental impairment. CONCLUSION: Infants born to mothers with MFI should have serial neonatal cranial ultrasound examinations to detect CNS injury and neurodevelopmental assessment during early childhood.

Adult↗