A novel phospholipid in irreversibly sickled cells: evidence for in vivo peroxidative membrane damage in sickle cell disease

In individuals with sickle cell disease, a variable number of irreversibly sickled cells (ISC) is present that may contribute to the pathophysiology of sickle cell anemia. The present study was undertaken to determine the possible role of membrane lipid peroxidation in the genesis of ISC. After 24 hr of simple aerobic incubation, sickle cells accumulated 2-3 times more malonyldialdehyde (MDA), an end product of lipid peroxidation, than normal cells. To assess the possibility of peroxidative damage in ISC in vivo, ISC were separated from sickle blood using Stractan density gradients. Lipid extracts of the untreated ISC-enriched fraction of sickle blood showed significant fluorescence and contained a novel phospholipid:MDA adduct that was not seen in control cells. Taken together, these observations suggest that ISC have previously undergone lipid peroxidative damage and the accumulation of MDA in vivo.     

Inaccuracies associated with the automated measurement of mean cell hemoglobin concentration in dehydrated cells

Because of discrepancies between electronically and manually measured values of mean cell hemoglobin concentration (MCHC) encountered in studies of pathologic red cells, we studied the effect of cell water content on MCHC measurements by both methods. A series of red cell samples with varying water contents (54%-164% normal) were prepared from normal cells using the antibiotic nystatin. MCHC was then measured, using the microhematocrit centrifuge and three different electronic cell counters in common laboratory use. For MCHC values above 36 g/dl as measured by the spun hematocrit method, all three electronic counters under estimmated the MCHC, with increasing error as the true MCHC increased. For MCHC values below 30 g/dl, the values from two conductivity based instruments agreed with those from the spun hematocrit method, whereas one instrument based on light scattering overestimated the MCHC. These results indicate that inaccuracies in the measured mean cell volume (MCV) of dehydrated or otherwise undeformable cells may lead to spurious values for MCHC when electronic cell counters are used.     

Breast feeding as prophylaxis for atopic eczema: a controlled study of 368 cases

The present study was undertaken in an attempt to draw data whether breast-feeding is beneficial in prevention of atopic eczema. Three-hundred and sixty-eight babies given different feeding modalities were examined for the presence of atopic eczema at the age of three and six months. Seven percent of breast-fed infants developed eczema compared to 10% of formulae-fed and 6% of mixed breast and formulae-fed infants. No difference in the severity of atopic eczema was recorded in the three study groups. Our experience demonstrates the absence of a protective effect of breast-feeding against the development and severity of atopic eczema.     

Pre-excitation syndrome in infants and children. Effect of digoxin,verapamil, and amiodarone.

Clinical and electrocardiographic findings for 30 patients with the pre-excitation syndrome are described together with details of treatment. Nineteen (63%) were younger than 2 years, 14 of whom were under 2 months. Sixteen infants and 7 children (77%) presented with paroxysmal supraventricular tachycardia, 14 (61%) of whom had the electrocardiographic pattern of type A Wolff-Parkinson-White (WPW) syndrome. During paroxysmal bouts the QRS complex was normal in 21 patients and wide in two. Six (20%) patients had congenital heart disease often associated with WPW syndrome type B. Seventeen patients were treated with either digoxin or verapamil intravenously to stop tachyarrhythmias. Verapamil was more effective due to the immediate response and lack of adverse effects. The tachyarrhythmias resolved in all the patients and in some of them the WPW pattern resolved later indicating maturation of the conduction tissue with loss of the accessory pathways. Verapamil provides a rapid and safe form of treatment for conversion of tachyarrhythmias since it has no effect on the accessory pathways. Oral amiodarone prevents recurrent tachyarrhythmias resistant to other treatment.     

The management of pediatric cholesteatoma

Pediatric cholesteatoma can be congenital or acquired. The two types appear to be separate and distinct entities based on molecular studies and clinical course. Pediatric cholesteatoma behaves differently from cholesteatomas in the adult. This may have more to do with anatomic and physiologic differences than with the molecular structure of the cholesteatoma. Treatment requires an individualized approach taking into account the experience of the operative surgeon and the high risk of recidivism of this disease.     

Neurotologic follow-up after radiation of posterior fossa tumors

OBJECTIVE: Stereotactic radiation treatment, also known as gamma knife surgery or radiosurgery, has come into acceptance as a treatment alternative to surgical removal for posterior fossa tumors. The purpose of this article is to describe the role of the neurotologist in the optimal management of neurotologic complications after stereotactic radiation, as illustrated by five patients. STUDY DESIGN: Retrospective chart review. PATIENTS: Five patients who underwent stereotactic radiation of posterior fossa tumors. MAIN OUTCOME MEASURES: Presence or absence of neurotologic complications (tumor growth, hearing loss, imbalance/ataxia, vertigo, and facial paralysis) or neurosurgical complaints (facial numbness, motor weakness, headache, hydrocephalus, and subarachnoid cysts). RESULTS: Postradiation neurotologic complaints included vertigo, imbalance/ataxia, and progressive hearing loss in four of the five patients. Continued tumor growth occurred in two patients; two patients had no growth; in one patient the tumor became smaller. The complications of facial nerve paralysis, facial numbness, motor weakness, headache, hydrocephalus, cerebellar edema, and posterior fossa arachnoid cyst formation occurred less frequently. CONCLUSIONS: Stereotactic radiation of posterior fossa tumors can produce significant neurotologic problems. It is imperative that neurotologists remain involved in the follow-up care of patients with posterior fossa tumors to offer optimal treatment alternatives for the neurotologic disorders.