Back pain in in-vitro fertilized and spontaneous pregnancies

The influence of ovarian stimulation in in-vitro fertilization (IVF) on the prevalence of back pain with onset during pregnancy was studied in 31 women who became pregnant after IVF treatment and compared with that of 200 spontaneously pregnant women. A two times higher prevalence rate of sacral pain in late pregnancy was reported among IVF pregnant women (P < 0.0001), as well as a significantly higher prevalence rate of positive results of pelvic pain provocation tests performed in late pregnancy (0.0001 < or = P < or = 0.015), as compared with that of the spontaneously pregnant women. Among the IVF pregnant women, there was a significant positive correlation between relaxin concentrations in early pregnancy and the outcome of pelvic pain provocation tests (0.44 < or = r < or = 0.51, P < 0.05). In addition, the serum relaxin concentration was the factor that best explained differences in sacral pain prevalence. When the influence of serum relaxin concentration on back pain prevalence was taken into account, women carrying multiple pregnancies had no more pain than women carrying singletons, and IVF pregnant women had no more pain than spontaneously pregnant women. These results support the hypothesis that relaxin is involved in the generation of pelvic pain in pregnant women.      

Molecular cloning and complete nucleotide sequence of galinsoga mosaic virus genomic RNA

Summary.  The complete genomic sequence of galinsoga mosaic virus (GaMV) was determined. The genome consists of 3 803 nucleotides and has five open reading frames (ORFs). The 5′ ORF (ORF 1) encodes a protein with predicted molecular mass of 23 kDa and readthrough of its amber stop codon probably yields a 82 kDa protein (ORF 2). ORFs 3 and 4 encode two polypeptides with molecular masses of 8 and 7 kDa, respectively. ORF 5 encodes the 36 kDa capsid protein. Amino acid sequence comparisons revealed that the nonstructural proteins encoded by ORFs 1, 3, and 4 were more similar to the corresponding gene products of tobacco necrosis virus, strain A, than to those of carmoviruses. Conversely, the coat protein was more similar to that of tombusviruses. The readthrough region of the viral replicase (ORF 2) had high sequence homology with that of carmo-, tombus-, and necroviruses. Computer analysis of the protein encoded by ORF 1 as well as of the corresponding product of turnip crinkle (TCV) and melon necrotic spot (MNSV) carmoviruses revealed the presence of a sequence with local hydrophobicity and hydrophobic moment characteristic of mitochondrial targeting sequence which may explain the origin of the carmovirus-induced multivesicular bodies from mitochondria. Accepted August 25, 1997 Received June 18, 1997     

Polymerization of human prion peptide HuPrP 106–126 to amyloid in nucleic acid solution

Summary.  The human prion peptide PrP106–126 polymerizes in the presence of DNA both in its circular and linearized forms under solution conditions where the peptide alone does not polymerize. The polymerization process has been monitored by the increase in the fluorescence of anilino naphthalene sulfonic dye which detects the availability of the hydrophobic surface(s) in the aggregate as a consequence of polymerization. The polymerization is a nucleation dependent phenomenon as is evidenced from an existence of a lag period before the onset of the polymerization and a strong dependence of the polymerization on the prion peptide concentrations. The reaction is dependent on the pH as seen from rapid polymerization at pH 5 compared to the reaction at neutral pH where no polymerization is observed after a relatively long period of incubation. The polymer has been characterized as amyloid by using new absorbing and emitting species resulting from the interaction of the polymer with the amyloid specific fluorescent dye, Thioflavine S. This is probably the first demonstration that an endogenous macromolecule can influence the polymerization of a prion peptide. We have previously shown that there is a conformational change in the nucleic acid as a consequence of this interaction. This prion peptide is considered as a model to understand prion diseases as is evidenced from its toxicity towards primary brain cells in culture. The peptide encompasses one of the important amyloidogenic regions of the normal cellular prion protein. Demonstration of nucleic acid induced polymerization of the normal and scrapie prion isoforms accompanying a change in the nucleic acid conformation can establish a possible role of nucleic acid in prion disease. Received January 8, 1997 Accepted March 4, 1998     

Serum fractions and related agonists with calcium-mobilizing activity in the bovine growth plate chondrocyte

Longitudinal growth of bone involves a complex sequence of cellular events in the cartilaginous epiphysis. Whole blood serum has been shown previously to be a potent stimulus to the cells of the growth plate, as demonstrated by its ability to activate the inositol phosphate-calcium second messenger system resulting in a rise in intracellular Ca²⁺. By manipulating the preparation of serum to functionally separate it into its constituent parts, we have shown that the processes of platelet lysis and activation of the clotting cascade are responsible for the generation of factors that stimulate this signaling mechanism in isolated bovine growth plate chondrocytes. Through a subsequent trial of bioactive agents generated in these processes, we identified and partially characterized several novel agonists of growth plate chondrocytes: adenosine triphosphate and adenosine diphosphate, the purine energy substrates, and bradykinin, the bioactive peptide generated in a side reaction of the clotting cascade, each induces a rise in intracellular Ca²⁺ via release from intracellular ion stores. Additionally, the three distinct isoforms of platelet-derived growth factor (AA, AB and BB), also released on platelet lysis, were compared with respect to their ability to stimulate the inositol phosphate-calcium second messenger system in growth plate chondrocytes.     

A low cost modification of an old Leksell stereotactic frame to allow CT-guided stereotaxy

The high cost of commercial CT-compatible stereotactic frames has restricted the availability of CT-guided stereotaxy for many neurosurgical centres. However, many of these centres do possess the standard stereotactic frames for projection radiography, of which the old type Leksell frame is probably the most common. We have devised a simple and low-cost modification to an old Leksell frame to allow CT-guided stereotaxy. The nature of the modifications allow complete freedom of positioning of the frame relative to the CT scanner and coordinate transformations can be performed simply and effectively. The modified frame has been used successfully for some 18 months and the modification has now been performed at two centres in the North West Regional Health Authority. We hope this modification will allow many other centres to embark on CT-guided stereotaxy.