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E Newton

Publications and source records attributed to E Newton.

26 records · Page 2Linked to original sources
PubMed1990

Molecular cloning of cDNA encoding a 55-kDa multifunctional thyroid hormone binding protein of skeletal muscle sarcoplasmic reticulum.

A cDNA clone encoding 55-kDa multifunctional, thyroid hormone binding protein of rabbit skeletal muscle sarcoplasmic reticulum was isolated and sequenced. The cDNA encoded a protein of 509 amino acids, and a comparison of the deduced amino acid sequence with the NH2-terminal amino acid sequence of the purified protein indicates that an 18-residue NH2-terminal signal sequence was removed during synthesis. The deduced amino acid sequence of the rabbit muscle clone suggested that this protein is related to human liver thyroid hormone binding protein, rat liver protein disulfide isomerase, human hepatoma beta-subunit of prolyl 4-hydroxylase and hen oviduct glycosylation site binding protein. The protein contains two repeated sequences Trp-Cys-Gly-His-Cys-Lys proposed to be in the active sites of protein disulfide isomerase. Northern blot analysis showed that the mRNA encoding rabbit skeletal muscle form of the protein is present in liver, kidney, brain, fast- and slow-twitch skeletal muscle, and in the myocardium. In all tissues the cDNA reacts with mRNA of 2.7 kilobases in length. The 55-kDa multifunctional thyroid hormone binding protein was identified in isolated sarcoplasmic reticulum vesicles using a monoclonal antibody specific to the 55-kDa thyroid hormone binding protein from rat liver endoplasmic reticulum. The mature protein of Mr 56,681 contains 95 acidic and 61 basic amino acids. The COOH-terminal amino acid sequence of the protein is highly enriched in acidic residues with 17 of the last 29 amino acids being negatively charged. Analysis of hydropathy of the mature protein suggests that there are no potential transmembrane segments. The COOH-terminal sequence of the protein, Arg-Asp-Glu-Leu (RDEL), is similar to but different from that proposed to be an endoplasmic reticulum retention signal; Lys-Asp-Glu-Leu (KDEL) (Munro, S., and Pelham, H.R.B. (1987) Cell 48, 899-907). This variant of the retention signal may function in a similar manner to the KDEL sequence, to localize the protein to the sarcoplasmic or endoplasmic reticulum. The positively charged amino acids Lys and Arg may thus interchange in this retention signal.

Amino Acid Sequence↗
PubMed1988

Antimicrobial activity of amniotic fluid against Chlamydia trachomatis, Mycoplasma hominis, and Ureaplasma urealyticum.

Amniotic fluids obtained by amniocentesis at 16 weeks to term were examined for the presence of Chlamydia trachomatis, Mycoplasma hominis, and Ureaplasma urealyticum. Of 140 fluids tested, none harbored chlamydiae, and only one harbored mycoplasma, M. hominis. A number of amniotic fluids were subsequently tested for their ability to inhibit the growth of these microorganisms. Amniotic fluids and chlamydial suspensions in a 2:1 ratio were incubated 30 to 90 minutes before their inoculation in McCoy cells. Procedures were followed for chlamydial isolation. Genital mycoplasmas were incubated with amniotic fluid samples for 24 or 48 hours at 35 degrees C. Growth in amniotic fluid specimens was compared with growth in pseudoamniotic fluid and broth controls. Fourteen amniotic fluid specimens collected from gestations of 16 to 40 weeks, were found to be inhibitory to the formation of inclusions of C. trachomatis in McCoy cells. Ten amniotic fluid specimens (16 to 39 weeks, gestation) demonstrated various degrees of inhibition against M. hominis, and three fluids were inhibitory to the growth of Ureaplasma. The inhibitor was heat and protease resistant and activity was proportional to concentration. The molecular weight of the inhibitor was probably greater than 10,000 daltons, and pH, although perhaps a contributing factor, was not the cause of the inhibition.

Amniotic Fluid↗
PubMed1988

Intraamniotic infection in low-birth-weight infants.

Intraamniotic infection (IAI) complicating births of low-birth-weight infants (less than 2500 g) was compared with IAI in births of infants weighing greater than or equal to 2500 g for differences in neonatal and maternal infectious morbidity and mortality, as well as differences in microbiological isolates in amniotic fluid. Four hundred four cases of clinically diagnosed IAI were prospectively evaluated. Thirty-seven patients (9.2%) delivered neonates less than 2500 g, and 367 patients (90.8%) delivered neonates greater than or equal to 2500 g. The low-birth-weight group had a significant increase in the incidence of sepsis (16.2% vs. 4.1%, P = .005) and death from sepsis (10.8% vs. 0%, P less than .001). Additional intrapartum conditions that might further predispose the low-birth-weight group to an increased risk of sepsis were not evident. Evaluation of the amniotic fluid did not demonstrate any increase in prevalence of group B streptococci, Escherichia coli, or enterococci in the low-birth-weight group. The presence of gram-negative anaerobes was significantly increased, however, in low-birth-weight pregnancies with IAI (59.5% vs. 31.6%, P = .001).

Amniotic Fluid↗
PubMed1985

Infection and phagocytosis as possible mechanisms of rupture in premature rupture of the membranes.

The concept that premature rupture of the membranes is due to an infectious process is well accepted. However, no definitive data implicating a particular microorganism or a mechanism of action have been advanced. By the use of our recently developed experimental in vitro amnion-chorion reaction vessel model we have studied the effect of the peroxidase-hydrogen peroxide-halide antimicrobial system on these membranes. We have noted that amnion, chorion, decidua, and placental macrophages all possess peroxidase activity. Tissues collected from deliveries following labor (vaginal) are significantly higher in activity than those collected from deliveries with no labor (cesarean section). A mobilization of enzyme from macrophages to amnion appears to occur in the laboring patient. Increased protein hydrolysis is noted in membranes collected from patients without labor subjected to the peroxidase-hydrogen peroxide-halide cytotoxic system when compared with membranes from laboring patients. Bursting pressures of membranes collected from patients without labor are shown to be decreased when the membranes were incubated in the presence of lysolecithin or in the presence of amniotic fluid and phospholipase A2.

Amnion↗
PubMed1985

Positive correlation between mature amniotic fluid optical density readings and the absence of neonatal hyaline membrane disease.

Fetal pulmonary maturity is generally determined by analyzing amniotic fluid for surfactants. This task is accomplished by lipid extraction of the fluid and resolution, identification and quantitation of the isolated lipids with thin-layer chromatography. These methods are lengthy, cumbersome and often not available on demand. A quick, simple, reliable and economical test therefore would be highly desirable. We have been able to correlate an optical density (OD) reading of amniotic fluid at 650 nm greater than or equal to 0.15 with the absence of hyaline membrane disease (HMD). For 428 fluids in which an OD reading of greater than or equal to 0.15 was found and delivery occurred within 48 hours, HMD was present in only two infants. The accuracy of the test was 99.53% , with a false-positive rate of 0.47%. With the use of this simple and accurate test one can satisfy the requirement of an on-demand test to determine fetal pulmonary maturity.

Amniotic Fluid↗
PubMedDate not supplied

The presentation of tetanus in an emergency department.

Traditionally, the literature has described a certain population as at risk for tetanus infection. We reviewed the demographics, clinical presentation, laboratory findings, management, and outcome of all patients who presented to our emergency department (ED) with tetanus in the last 10 years and compared our experience with this classic literature. We performed a retrospective case series review at a large, inner-city medical center; 11 cases of tetanus were identified from 1986 to 1997. Nine male and two female patients were identified with an average age of 45 years. All had an acute injury to the skin, and most (82%) reported having no history of recent immunization. The most common recorded symptoms were trismus and rigidity in the abdomen, neck, back, or extremities. There was only one misdiagnosis in the ED. Three patients died in the hospital, while the other eight were discharged either home or to a rehabilitation facility. In contrast to the classic literature, we found that tetanus in our inner city ED presented in recent immigrants, particularly younger men, over half of whom had received no childhood immunization. Laboratory results and cultures are of little diagnostic value, so timely recognition of the clinical presentation is important.

Adult↗