Prenatal sonographic and MRI findings in a pregnancy complicated by uterine sacculation: case report and review of the literature.

Approximately 15% of women have a retroverted uterus prior to pregnancy, and retroversion occurs in 11% of women in the first trimester of pregnancy. However, the uterus usually moves to an upward position before 14 weeks' gestation. Incarceration and sacculation of a retroverted uterus occur in 1 in 3000 pregnancies and are difficult to diagnose. They have often been missed until shortly before delivery and can lead to serious obstetric emergencies such as labor dystocia, uterine rupture, retained placenta and uncontrollable postpartum hemorrhage. Performing a Cesarean section without correct diagnosis may cause difficulties in identifying the bladder and the cervix, and therefore in opening the lower uterine segment. This leads to bladder injuries, vaginal transsection and trans- or supracervical hysterectomy. Early diagnosis and detailed scanning are crucial for the obstetric management and operative approach.We report a case of an incarcerated uterus in a patient presenting at 24 weeks' gestation with severe bilateral flank and lower abdominal pain. The symptoms were misdiagnosed as appendicitis. Digital examination revealed a ventralized vaginal axis. The cervix was not palpable. The clinical course, and two- and three-dimensional ultrasound and magnetic resonance imaging findings, are presented. The delivery was performed by midline laparotomy Cesarean section. The management for different gestational ages and a review of the literature are discussed.

Orcein and litmus.

Orcein was separated into 14 dyes by partition chromatography. Their constitutions were determined mainly by spectroscopy and led to formulae that are derived from 7-amino-2-phenoxazone, 7-hydroxy-2-phenoxazone, and 7-amino-2-phenoxazime, and that were confirmed by syntheses. The major constituent of litmus is assembled polymerically from 7-hydroxy-2-phenoxazone chromophores. The mechanism of formation is elucidated.

Creatinine deiminase (EC 3.5.4.21) from bacterium BN11: purification, properties and applicability in a serum/urine creatinine assay.

Creatinine deiminase (EC 3.5.4.21) from the anaerobic microorganism BN11 has been purified to homogeneity by ammonium sulfate fractionation, gel filtration on Sephacryl-S-300 superfine and chromatography on DEAE-Sepharose C1 6B. The final enzyme preparation had a specific activity of 78 units per mg protein. Analysis of creatinine deiminase by polyacrylamide gradient gel electrophoresis and fast-flow-liquid-chromatography gave a relative molecular mass of 285 kDa and 288 kDa, respectively. By treatment with sodium dodecylsulfate and 2-mercaptoethanol creatinine deiminase was dissociated yielding one polypeptide with a relative molecular mass of 47.5 kDa. The enzyme was entirely specific for creatinine and showed a Km value of 0.15 mM. Creatinine deiminase was used to determine the concentration of creatinine in serum and urine using a manual method and an automated system.

Influence of the activation state on the sedimentation properties of ribulose bisphosphate carboxylase from Alcaligenes eutrophus.

Ribulose-1,5-bisphosphate carboxylase from the chemolithotrophic hydrogen bacterium Alcaligenes eutrophus was maximally active in the presence of 50 mM HCO3- plus 10 mM Mg2+. Deactivation occurred upon removal of these ions. Reactivation was achieved by incubation of the enzymes with HCO3- plus Mg2+. The concentration of HCO3- (CO2) required for half-maximal activation was 1.84 nM (0.064 mM). Sedimentation velocity studies revealed that activation/deactivation is associated with drastic changes in the sedimentation properties of the enzyme. While the inactive form had a sedimentation coefficient, s20,w, of 17.5 S, the s20,w gradually decreased as the enzyme was reactivated and the fully reactivated form exhibited an s20,w of 14.3 S. A structural analogue of ribulose 1,5-bisphosphate, xylulose 1,5-bisphosphate, caused a deactivation of the enzyme concomitant with an increase in the sedimentation velocity. It is suggested that the alterations in the hydrodynamic properties accompanying the activation/deactivation process are due to considerable conformational changes that affect the molecular volume and/or the shape of the enzyme. Dissociation/association events were not involved in the changes. The s20,w of about 18 S, generally reported for the large hexadecameric ribulose bisphosphate carboxylases, appears to be characteristic of the inactive form.

Determination of molecular weight and molecular structure of rat-liver pyruvate carboxylase.

The molecular weight of pyruvate carboxylase isolated from pigeon and rat liver mitochondria was examined using analytical ultracentrifugation and electron microscopy. The enzyme molecule appeared as a tetramer with the four subunits arranged at the corners of a square. Sedimentation studies in the analytical ultracentrifuge, extrapolated to infinite dilution, showed the tetramer to have a molecular weight Mc=0r of 280 000 and an So20,w of 12.7 S. The tetramer could be dissociated into trimers and dimers of lower specific enzymic activity by storage at 4 degrees C or incubation at -- 20 degrees C at low protein concentrations. The isolated trimers and dimers had a molecular weight Mc=0r of 210 000 and 140 000, respectively, and an So20,w of 10.85 S and 7.55 S, respectively. Incubation with 2 M urea at 20 degrees C yielded enzymically inactive subunits (Mc=0r = 70 000; So20,w = 4.95 S). The molecular weights (for pyruvate carboxylase and its subunits), as calculated from the subunit diameter observed in the electron microscope, were consistent with the values obtained from sedimentation studies.