Epidurals, spinals and bleeding disorders in pregnancy: a review

Paraplegia caused by spinal haemorrhage is a very rare but disastrous complication of spinal or epidural insertion. The risk in uncomplicated surgical and obstetric patients is outlined. Bleeding disorders in pregnant patients may prevent the use of major regional anaesthesia. Factors which influence the choice of anaesthetic technique for patients with pregnancy-induced hypertension, von Willebrand's disease, and anticoagulation therapy, are discussed.     

Novel translocations in acute nonlymphocytic leukemia. Two cases involving chromosome 21, band q22

We present two cases in which translocations involving 21q22 were found at presentation in acute nonlymphocytic leukemia (ANLL). The first of these translocations, t(3;21)(q26-q27;q22), is previously unknown in ANLL, but appears indistinguishable from that reportedly associated with Philadelphia-positive chronic myelogenous leukemia. The second case involves t(15;21)(q21-q22;q22), a translocation previously undescribed in ANLL. Both of these exchanges involve 21q22 plus another chromosome region associated with leukemogenesis. We attempted to interrelate these cytogenetic data with the oncogenic significance of 21q22.     

The Ca2(+)-binding glycoprotein SPARC modulates cell cycle progression in bovine aortic endothelial cells.

SPARC (secreted protein, acidic and rich in cysteine) is an extracellular, Ca2(+)-binding protein associated with cellular populations undergoing migration, proliferation, and/or differentiation. Active preparations of SPARC bind to specific components of the extracellular matrix and cause mesenchymal cells to assume a rounded phenotype. In this study we show that SPARC modulates the progression of bovine aortic endothelial cells through the cell cycle. At a concentration of 20 micrograms/ml, SPARC inhibited the incorporation of [3H]thymidine into newly synthesized DNA by approximately 70%, as compared to control cultures within 24 hr after the release from G0 phase. The effect was dose-dependent and reached greater than 90% inhibition at 30 micrograms of SPARC per ml after 24 hr. A 20-residue synthetic peptide (termed 2.1) from a non-Ca2(+)-binding, disulfide-rich domain of SPARC also exhibited a dose-dependent inhibition of [3H]thymidine uptake in endothelial cells within 24 hr after release from G0 phase. An inhibition of 50% was seen with peptide 2.1 at a 0.4 mM concentration. Peptides from other regions of the SPARC protein did not produce this effect. Maximum inhibition of [3H]thymidine uptake by SPARC and peptide 2.1 occurred during the early-to-middle G1 phase of the endothelial-cell cycle. From 0-12 hr after release from G0 phase, cells exhibited delayed entry into S phase, which normally occurred at 24 +/- 2 hr. These results were further corroborated by flow cytometry. In the presence of SPARC at 20 micrograms/ml, 72% fewer cells were in S phase after a 24-hr period; a similar, but less marked, reduction was seen with peptide 2.1. Peptide 2.1 did not cause cell rounding, whereas peptide 1.1, a highly efficient inhibitor of endothelial-cell spreading, exhibited essentially no activity with respect to cell-cycle progression. It therefore appears that the transient, inhibitory effect of SPARC on the entry of endothelial cells into S phase does not depend on the overt changes in cell shape mediated through cytoskeletal rearrangement.     

Isolated jejunal pouches for levodopa delivery in parkinsonian patients with "on-off". Successful experimental model in dogs

In eight dogs, a 20 cm section of isolated jejunum with intact blood supply was externalized to the abdominal wall and used as a device for levodopa (LD) administration. Overall, Sinemet tablets and LD suspension produced similar plasma levodopa concentrations with oral and pouch administration. The most ideal plasma concentration curves were obtained for CR-3, a sustained release Sinemet preparation, given through the jejunal pouches. Plasma LD concentrations rose within the first hour after administration of CR-3 and remained constant for the next 3 h, before falling slowly. Isolated jejunal pouches may therefore be an effective, simple means of maintaining constant plasma LD concentrations in parkinsonian patients with motor fluctuations and may diminish the deleterious effects of erratic gastric emptying and competition with food-derived amino acids at the gut/blood transport system.     

Surfactant replacement therapy in neonates with respiratory failure due to bacterial sepsis

We describe four newborns (gestational ages 29-37 weeks; birthweights 1380-3040 grams) who were mechanically ventilated for respiratory insufficiency because of bacterial sepsis. A beneficial effect of bovine surfactant (Alvofact, dosages 50 or lOOmg/kg) was found, as shown by decreases in mean airway pressures and oxygen demands. No side effects were seen after instillation.     

Transferrin saturation, plasma iron turnover, and transferrin uptake in normal humans

The relationship between plasma iron, transferrin saturation, and plasma iron turnover was studied in 53 normal subjects whose transferrin saturation varied between 17% and 57%, in 25 normal subjects whose transferrin saturation was increased by iron infusion to between 67% and 100%, and in five subjects with early untreated idiopathic hemochromatosis whose transferrin saturation was continually elevated to between 61% and 86%. The plasma iron turnover of all of these subjects ranged from 0.45 to 1.22 mg/dL whole blood/d. The mean values for the above-mentioned three groups were 0.71 +/- 0.17, 1.01 +/- 0.11, and 1.01 +/- 0.13 mg/dL whole blood/d, respectively. Most of this variation, estimated at 72% by regression analysis, was due to a direct relationship between transferrin saturation and plasma iron turnover. This effect was attributed to a competitive advantage of diferric over monoferric transferrin in delivering iron to tissues. This was confirmed by the demonstration of a more rapid clearance of diferric as compared to monoferric transferrin in an additional group of eight normal subjects. Calculations were made of the amount of transferrin reacting with membrane receptors per unit time. Allowance was made for the noncellular (extravascular) exchange and for the 4.2:1 preference of diferric over monoferric transferrin demonstrated in vitro. The amount of iron-bearing transferrin leaving the plasma to bind to tissue receptors for 53 subjects with a transferrin saturation between 17% and 57% was 71 +/- 13; for 25 subjects with a saturation from 67% to 100%, 72 +/- 12; and for five subjects with early idiopathic hemochromatosis, 82 +/- 11 mumol/L whole blood/d. There were no significant differences among these groups. These studies indicate that while the number of iron atoms delivered to the tissues increases with increasing plasma iron and transferrin saturation, the number of iron-bearing transferrin molecules that leave the plasma per unit time to bind to tissue receptors is relatively constant and within the limits studied, independent of transferrin saturation.