Coagulation factor deficiency as a cause of recurrent fetal loss: a red herring!

Whether severe coagulation factor deficiency can cause adverse pregnancy outcomes or recurrent fetal loss is not definitely known. We report here on five women with severe deficiency of coagulation factors (two factor X, one factor XI, one factor VII and one von Willebrand factor) who presented with history of unexplained fetal loss or with adverse pregnancy outcome. Detailed investigations of thrombophilia showed that four patients were positive for antiphospholipid antibodies, one of whom was also homozygous for the plasminogen-activator inhibitor-1 4G/4G polymorphism, and the fifth patient was deficient for protein C. Despite the concomitant presence of both coagulation factor defect and thrombophilia, fetal loss may be attributed to factor defect that in reality is a red herring, with underlying thrombophilia not being evaluated.     

Optimal management of adults with pharyngitis – a multi-criteria decision analysis

Background  

Current practice guidelines offer different management recommendations for adults presenting with a sore throat. The key issue is the extent to which the clinical likelihood of a Group A streptococcal infection should affect patient management decisions. To help resolve this issue, we conducted a multi-criteria decision analysis using the Analytic Hierarchy Process.     

Neurogenesis and development of callosal and intracortical connections in the hamster

The developmental time-course of callosal and ipsilateral corticocortical projections was studied in embryonic and postnatal hamsters, from the time of neurogenesis until the appearance of adult patterns. Callosal neurogenesis was determined by combining the incorporation of [3H]thymidine injected on specific embryonic days with retrograde labelling of callosal neurons in the adult animal. The development of both callosal and corticocortical projections was studied by the transport of wheat germ agglutinin conjugated to horseradish peroxidase. Despite a significant radial disperson of postmigratory neurons born on the same day, it was found that the birthdates of callosally-projecting neurons in the frontal cortex were not restricted to a short period of time, but extended between embryonic days 13 and 15. This period covers the neurogenesis of cells in cortical layers III-V. Elongation of callosal axons (and possibly also of corticocortical fibres) started a couple of days before birth in the frontal cortex, and continued through the first postnatal days. After a "waiting period" of a few days, axons from both sets of projections were seen innervating restricted target sectors of the cortex. The zones of origin of these projections were initially exuberant, but were subsequently trimmed to overlap completely with the corresponding terminal fields. It is concluded that callosal and ipsilateral corticocortical projections undergo similar sequences of ontogenetic stages, suggesting that the development of neocortical connectivity as a whole may be governed by one and the same set of rules.     

Malassezia furfur in a case of onychomycosis: colonizer or etiologic agent?

The etiologic role of Malassezia furfur in onychomycosis is a contentious diagnostic problem because its keratinolytic ability has never been verified. This case report describes the isolation of M. furfur from the infected nails of a child clinically diagnosed with onychomycosis, and discusses the role of this organism as an etiologic agent/colonizer. The patient presented with subungual hyperkeratosis and onycholysis without associated paronychia. Budding yeast cells compatible with M. furfur were repeatedly demonstrated in KOH wet mounts of damaged nails, histopathology of hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS) stained sections showed penetration of fungal elements between deeper layers of keratin, and numerous colonies of M. furfur were isolated on three consecutive occasions from nail specimens collected from different areas of hand and toenail lesions. No evidence of nail invasion by dermatophytic or nondermatophytic filamentous fungi were found by direct microscopy or culture. Microscopy and culture were negative following 12 weeks of ketoconazole treatment, which resulted in growth of healthy nail plates with normal beds. We can infer from these observations that M.furfur was an etiologic agent rather than a colonizer in the patient's nails even though direct keratinolytic character of this fungus was not demonstrated.     

Evaluation of oxygen saturation monitoring by pulse oximetry in neonates in the delivery system

The pulse oximeter was evaluated for use in neonates in the delivery room. One hundred neonates, delivered vaginally or by Caesarean section with general or epidural anaesthesia, were studied. After delivery, pulse oximetry probes were placed simultaneously on the ulnar side of the right hand and on the right Achilles tendon to determine whether there was a difference in arterial oxygenation (SpO2). Measurements of SpO2 were taken at 1, 5, 10 min, and 24 hr after delivery. At one and five minutes, SpO2 recorded from the right hand was higher than that recorded from the lower extremities (71.9% +/- 6.5% vs 63.4% +/- 4.3% and 83.3% +/- 4.2% vs 76% +/- 4.1%, mean +/- SD, respectively). At ten minutes these differences diminished, and had almost completely disappeared after 24 hr. These results can be explained by the presence of R-L shunting at the ductus arteriosus level, producing reduced SaO2 in the lower extremities. Oxygen saturation did not differ between neonates delivered vaginally or by Caesarean section, regardless of the presence or type of anaesthesia. We concluded that neonates remain relatively desaturated in the immediate postpartum period and that the SpO2 obtained from the right hand is a better index of neonatal oxygenation than that obtained from the heel.     

Early postnatal expression of L1 by retinal fibers in the optic tract and synaptic targets of the Syrian hamster

Previous immunohistochemical studies in mouse, rat, and chick have reported that the expression of the glycoprotein and cell adhesion molecule L1, a member of the immunoglobulin superfamily, shows regulation during development of retina and optic nerve. To extend our understanding of the role of L1 in developing neural circuitry, we have examined L1 expression in the optic tract and thalamic and midbrain synaptic targets of retinal fibers in the early postnatal Syrian hamster, a well-characterized developmental model of the primary visual projection. Metabolic labeling studies reveal that a synaptically targeted, sulfated, and glycosylated form of L1 undergoes rapid axonal transport from the retina. Retinofugal transport of L1 decreases commensurate with the decline in immunoreactivity of retinal fibers in the visual pathway. Retinal ganglion cell axons show intense L1 immunoreactivity as they navigate in highly fasciculated bundles in the optic tract overlying the lateral geniculate body and in the superior colliculus. We found no evidence of L1 immunoreactivity on retinal axon collaterals as they defasciculate from the optic tract and branch into target neuropils. L1 immunoreactivity wanes in optic tract as axon terminal arbors are elaborated in the lateral geniculate body and superior colliculus and as myelination in the visual pathway commences. This pattern of L1 expression suggests that, in the early postnatal period, L1 may support fasciculation of retinal fibers, maintaining them within the optic tract, and that subsequent down-regulation of L1 may facilitate their terminal arborization and myelination.