A biomechanical study using cadaveric toes to test the stability of fixation techniques employed in arthrodesis of the first metatarsophalangeal joint

Arthrodesis of the first metatarsophalangeal joint of 15 pairs of cadaveric big toes were performed. The arthrodesis site was shaped with either a dome and socket or planar surface contact between the metatarsal head and proximal phalanx. A template was used to standardize the position of arthrodesis in 20 degrees of valgus and 20 degrees dorsiflexion. Various fixation devices were used to hold this position in corresponding pairs of specimens, and these fixation devices were tested to determine their relative effectiveness to prevent displacement on loading. Force-deflection curves were obtained for the various techniques tested, and by comparing these curves, the stability of the metatarsophalangeal arthrodesis site was found to be maintained most effectively using the cancellous screw fixation device with planar metatarsophalangeal surfaces.

The phospholipids of lamellar body material from fetal rabbit lung tissue in culture. Unusual phosphatidylcholine fatty acid profile

Tissue pieces of rabbit fetal lung, 23 days gestation, were cultured for 7 days in serum-free medium to obtain lamellar body material for phospholipid analysis. Cultures were maintained in culture medium without serum and (1) with no added hormones (control cultures), (2) with thyroxine (1 x 10(-7) M), (3) with cortisol (1 x 10(-7) M) and (4) with thyroxine plus cortisol (1 x 10(-7) M each). The hormonal response was evaluated by measuring the quantity of lamellar body material isolated from the tissue pieces after the 7-day culture period. Compared to control cultures, more lamellar body material was recovered from cultures treated with cortisol (180% of control) and with thyroxine plus cortisol (250% of control). Cultures treated with thyroxine alone yielded the same amount of lamellar body material as the controls. Hormone treatment produced only minor changes in the glycerophospholipid profile of the lamellar body material. A small but significant increase in the percentage of phosphatidylglycerol and a small but significant decrease in phosphatidylinositol were found in lamellar body material from cultures treated with thyroxine and thyroxine plus cortisol. The disaturated phosphatidylcholine content of the lamellar body material from culture was 28% of the total lamellar body phospholipid and was not affected by hormone treatment. This disaturated phosphatidylcholine content was low compared to the disaturated phosphatidylcholine of lamellar body material from adult lung (46%). The low proportion of disaturated phosphatidylcholine was due to the unusual presence of palmitoleic acid (16:1(cis-9)), which was more than one-fourth of the total fatty acid of the lamellar body phosphatidylcholine. It is possible that an abnormal delta 9 fatty acid desaturation activity was expressed in the lung tissue in vitro, which resulted in the high incorporation of the 16:1 fatty acid into lamellar body phosphatidylcholine.

Fetal loss after implantation. A prospective study

The incidence of post-implantation pregnancy loss in 197 women was determined prospectively. The diagnosis of pregnancy was based on the detection of human chorionic gonadotropin in the urine during the luteal phase of each menstrual cycle. There were 152 conceptions in the 623 cycles studied with a pregnancy loss rate of 43%. 14 of the pregnancies ended in clinically recognised spontaneous abortions and in 50 the sole evidence of pregnancy was an increased concentration of urinary hCG. The maximum conception rate achieved was 36% in the first cycle after removal of an intra uterine device.

Two-site immunofluorometric assay for pregnancy-specific beta 1-glycoprotein (SP1)

We describe an immunoassay for human pregnancy-specific beta 1-glycoprotein by use of fluorescein-labeled antibodies to this protein. The technique is generally similar to that of a "two-site" immunoradiometric assay but has the advantage of stability of tracer and avoidance of radiation hazard. However, the procedure requires relatively large quantities of antibody. Furthermore, the within-assay coefficient of variation (11.8%) is greater than that for radioimmunoassay (6.5%). This results from imprecision of the end-point detection, and some inherent difficulties in optimizing a "two-site" immunometric system. Concentrations of endogenous material as measured by the fluorometric assay are 1.9-fold higher than those obtained with radioimmunoassay, probably because the former detects multiple forms of this heterogeneous material.

Two-site immunofluorometric assay for pregnancy-specific beta 1-glycoprotein (SP1)

We describe an immunoassay for human pregnancy-specific beta 1-glycoprotein by use of fluorescein-labeled antibodies to this protein. The technique is generally similar to that of a "two-site" immunoradiometric assay but has the advantage of stability of tracer and avoidance of radiation hazard. However, the procedure requires relatively large quantities of antibody. Furthermore, the within-assay coefficient of variation (11.8%) is greater than that for radioimmunoassay (6.5%). This results from imprecision of the end-point detection, and some inherent difficulties in optimizing a "two-site" immunometric system. Concentrations of endogenous material as measured by the fluorometric assay are 1.9-fold higher than those obtained with radioimmunoassay, probably because the former detects multiple forms of this heterogeneous material.

Monitoring fibrinolytic activity in the cerebrospinal fluid after aneurysmal subarachnoid haemorrhage: a guide to the risk of rebleeding?

Serial assay of fibrin degradation products (FDPs) was used to monitor fibrinolytic activity in blood and cerebrospinal fluid (CSF) after subarachnoid haemorrhage (SAH) in 64 patients, 43 of whom had aneurysms. CSF levels fell rapidly from high initial values over a few days, thereafter more slowly to reach normal levels after one to six weeks. Probably only the later slow decline is a measure of fibrinolysis, which is obscured in the first few days by the cross antigenicity with FDP's of fibrinogen released by the bleed. After this phase of fibrinogen clearance, early attainment of normal FDP levels appears to be associated with a lower risk of rebleeding in cases of aneurysm. This phenomenon could be useful in deciding whether marginal cases should be treated surgically or conservatively.

Fluoroimmunoassay for human choriomammotropin

We describe an immunoassay for human choriomammo-tropin by use of the fluorescein-labeled hormone (of human origin). The technique is generally similar to the radioimmunoassay for this material, but has the advantage of stability of tracer and avoidance of radiation hazard. However, the procedure requires approximately 50-fold more tracer than does the radioimmunoassay, and this would be a disadvantage with materials for which supplies of purified antigen are scarce. Furthermore, both within-assay variation (3.9%) and between-assay variation (7.8--7.9%) were less satisfactory than that of radioimmunoassay (1.5% and 2.2--3%, respectively). This is almost certainly the result of imprecision of end-point detection and could probably be corrected by further attention to equipment design.

Fluoroimmunoassay for human choriomammotropin

We describe an immunoassay for human choriomammo-tropin by use of the fluorescein-labeled hormone (of human origin). The technique is generally similar to the radioimmunoassay for this material, but has the advantage of stability of tracer and avoidance of radiation hazard. However, the procedure requires approximately 50-fold more tracer than does the radioimmunoassay, and this would be a disadvantage with materials for which supplies of purified antigen are scarce. Furthermore, both within-assay variation (3.9%) and between-assay variation (7.8--7.9%) were less satisfactory than that of radioimmunoassay (1.5% and 2.2--3%, respectively). This is almost certainly the result of imprecision of end-point detection and could probably be corrected by further attention to equipment design.

Characterisation of serum fibrinogen degradation products using gel chromatography and radioimmunoassay

Fibrin(ogen) degradation products (FDP) are detected by radioimmunoassay in the serum of all subjects. Some of these FDPs have considerable biological activity in vivo, and hence may play a significant part in the process of coagulation. Chromatography of serum samples from patients including those with pulmonary emboli and deep venous thrombosis indicates that the majority of non-clottable fibrin(ogen)-related antigen present is of high molecular weight--greater than that of fibrinogen--and that in pathological situations there is a quantitative increase not a qualitative alteration in the molecular species present.

Characterisation of Serum Fibrinogen Degradation Products Using Gel Chromatography and Radioimmunoassay

Fibrin(ogen) degradation products (FDP) are detected by radioimmunoassay in the serum of all subjects. Some of these FDPs have considerable biological activity in vivo, and hence may play a significant part in the process of coagulation. Chromatography of serum samples from patients including those with pulmonary emboli and deep venous thrombosis indicates that the majority of non-clottable fibrin(ogen)-related antigen present is of high molecular weight- greater than that of fibrinogen – and that in pathological situations there is a quantitative increase not a qualitative alteration in the molecular species present.