Ectopic Pregnancy in Lower Segment Uterine Scar

Summary: A case of ectopic pregnancy in a lower uterine segment scar following previous Caesarean section is reported. A significant scar defect may result in deep implantation within the myometrium with the risk of persistent pain and bleeding followed inevitably by uterine rupture. In this report we discuss a number of management options. Except in the special situation of superficial implantation in a shallow scar defect where there is ultrasound evidence of continuity of the gestational sac with the uterine cavity we would strongly advise termination of the pregnancy.     

Ribavirin disposition in high-risk patients for acquired immunodeficiency syndrome

Ribavirin is a broad-spectrum antiviral drug that has in vitro activity against human immunodeficiency virus. To determine the kinetics of ribavirin, 17 symptom-free homosexual men with lymphadenopathy were studied. Single doses of ribavirin, 600, 1200, or 2400 mg, were given orally or intravenously. The plasma ribavirin concentration-time profiles were well fitted by a three-compartment open model. Ribavirin followed linear kinetics over the dose range studied. The mean 1-hour postinfusion concentrations after intravenous ribavirin, 600, 1200, and 2400 mg, were 8.0, 19.7, and 37.1 mumol/L, respectively. The mean +/- SD plasma beta-phase half-life, terminal-phase (gamma) half-life, and volume of distribution at steady state were 2.0 +/- 1.1 hours, 35.5 +/- 14.0 hours, and 647 +/- 258 L, respectively. The mean ribavirin renal clearance and total body clearance were 99 +/- 30 and 283 +/- 37 ml/min, respectively. After an oral dose of 600, 1200, and 2400 mg, the mean peak plasma ribavirin concentrations (which occurred 1.5 hours after administration) were 5.1, 9.9, and 12.6 mumol/L, respectively. The mean absorption half-life and bioavailability of ribavirin were 0.5 hour and 45%. Ribavirin had no plasma protein binding and the drug accumulated within red blood cells. In conclusion, ribavirin is incompletely absorbed from the gastrointestinal tract, its renal excretion accounts for approximately one third of the drug's elimination, and drug accumulation (greater than threefold) will result with repetitive dosing at the 6- to 8-hour dosing interval currently used.     

L-arginine reverses the antinatriuretic effect of cyclosporin in renal transplant patients

BACKGROUND: Cyclosporin has been shown to facilitate renal vasoconstriction and to have an antinatriuretic effect. The existence of an interference of cyclosporin with the vasodilating properties of endothelium mediated by nitric oxide production could mediate these effects. On the other hand, the infusion of the nitric oxide precursor L-arginine has been shown to induce renal vasodilatation and to facilitate natriuresis in normal volunteers. We have investigated the renal effects of the administration of an infusion of L-arginine in renal transplant patients chronically treated with cyclosporin. To facilitate the analysis of the data the effects of the administration of a similar dose of cyclosporin on renal function during the infusion of a vehicle were also investigated during the administration of a vehicle of L-arginine. DESIGN: Ten male renal transplant patients, chronically treated with cyclosporin and with a stable renal function were studied during 2 consecutive days after the administration of the usual morning dose of cyclosporin. The first day they received an intravenous infusion of vehicle and the second the infusion of graded doses of L-arginine (50, 100, 150 mg/kg/h) during 3 consecutive h. RESULTS: The first day, after cyclosporin administration a significant fall (P < 0.01) was observed in natriuresis and kaliuresis in the absence of changes in renal plasma flow and glomerular filtration rate. After the administration of L-arginine significant (P < 0.01) increases of renal plasma flow, glomerular filtration rate, and natriuresis were seen. The increase in blood levels of cyclosporin after its administration did not differ between days 1 and 2. CONCLUSION: These results indicate that L-arginine facilitates renal vasodilatation and natriuresis in renal transplant patients. Furthermore, the observed increase in sodium excretion could indicate that L-arginine counteracts the antinatriuretic effect of cyclosporin.      

Cerebral infarction associated with protein C deficiency following allogeneic bone marrow transplantation.

Hypercoagulable states associated with deficiencies in circulating anticoagulant protein C occur after chemotherapy for a variety of malignant diseases. Protein C deficiency also occurs following bone marrow transplantation (BMT) and may be responsible for a variety of transplantation-associated complications. We report the case of a child who suffered a stroke associated with low protein C antigen and activity occurring 11 months after allogeneic BMT. Protein C levels recovered spontaneously by 18 months after BMT. We speculate that the protein C deficiency and and resultant hypercoagulable state led to the stroke, and the deficiency of this anticoagulant was a sequela of the transplant.     

Measurement of the quadriceps femoris muscle using magnetic resonance and ultrasound imaging.

OBJECTIVES: To define a method for measurement of the cross sectional area and volume of the quadriceps femoris muscle using magnetic resonance imaging (MRI) in conjunction with stereology, and to compare the results of measurements obtained by the MRI method with those obtained by the conventional method of static B-mode ultrasound in order to evaluate whether MRI is a reliable alternative to ultrasound. METHODS: A preliminary MRI study was undertaken on a single female volunteer in order to optimise the scanning technique and sampling design for estimating the muscle volume using the Cavalieri method. Ten healthy volunteers participated in the method comparison study. Each volunteer underwent static B-mode ultrasonography, immediately followed by MRI. The cross sectional area of the quadriceps femoris was estimated at the junction of the proximal one third and distal two thirds of the thigh, and seven systematic sections of the thigh were obtained in order to estimate muscle volume by both modalities. RESULTS: Seven sections through the muscle are required to achieve a coefficient of error of 4-5%. There was no significant difference in the cross sectional area estimates or volume estimates when ultrasound and MRI were compared. CONCLUSION: Muscle cross sectional area and volume can be measured without bias by MRI in conjunction with stereological methods and the method is a reliable alternative to static B-mode ultrasound for this purpose.     

Ibuprofen, a putative anti-cataract drug, protects the lens against cyanate and galactose

Cataract, the major cause of blindness world-wide, may be caused partly by modification of lens proteins by carbamylation and non-enzymic glycosylation (glycation) in some patients. Aspirin has been found to protect against these modifications and to prevent cyanate-induced opacification occurring in whole rate lenses. Ibuprofen is an aspirin-like anti-inflammatory drug which appeared as a protective factor against cataract in an Oxford case-control study. The binding of cyanate, galactose and glucose 6-phosphate to lens proteins, and the effect of ibuprofen on this reaction was investigated, as was cyanate-induced opacification in whole rat lenses. Labelled metabolite was incubated with bovine lens homogenate in the presence and absence of ibuprofen, and the incorporation of label into the lens homogenate was followed. Simultaneous and preincubation experiments were performed. Intact rat lenses were incubated in culture medium with and without cyanate and ibuprofen. The phase separation temperature was noted as the temperature at which opacity first appeared on cooling. Cyanate, galactose and glucose 6-phosphate bind progressively to lens proteins. Simultaneous incubation with ibuprofen reduces cyanate and galactose binding but not glucose 6-phosphate. Ibuprofen protects against opacities due to cyanate-induced phase separation. Ibuprofen has protected against cataract in the models of cataractogenesis in this study. It appears to have a different mechanism of action from that of aspirin. These studies provide some support for the idea, based on epidemiological findings, that ibuprofen might be a useful anti-cataract drug.     

The fluid content of the human intervertebral disc. Comparison between fluid content and swelling pressure profiles of discs removed at surgery and those taken postmortem.

The fluid content of the disc, which governs its mechanical response and biological behavior, varies with external load. Because load on the disc changes after death, the fluid content and swelling pressure profiles of human discs taken at autopsy were measured, and compared with discs removed during surgical procedures. In general, discs taken at surgery had a lower fluid content in the nucleus and a higher fluid content in the outer anulus than discs removed at autopsy. In discs removed at surgery, the swelling pressure of the nucleus was higher than that of the anulus, whereas in autopsy discs the swelling pressure profile was flat. These changes are though to result from changes in load after death, and could influence the results of in vitro mechanical tests on the disc.