Malaria: Review of features pertinent to the emergency physician

Malaria is a health problem of growing concern to the emergency physician. Plasmodium vivax, P ovale, and P malaria infections are relatively benign and can be treated in an outpatient setting with oral chloroquine or amodiaquine. In contrast, P falciparum can present fulminantly, often resulting in death with multiple organ system failure. Although quinine historically has been the mainstay of therapy for severe falciparum malaria in the United States, and still is outside the U.S., quinidine gluconate as a continuous infusion is currently recommended as the agent of choice for severe P falciparum infection. In addition to the rapid administration of appropriate chemotherapeutic agents and the institution of aggressive supportive care, exchange transfusion may be utilized as a means of rapidly reducing the parasitemia and consequently, the mortality.     

The future of therapy for glioblastoma

Effective therapy for malignant gliomas has centered on traditional approaches such as surgery and radiation therapy. Over the past two decades, more innovative approaches involving the use of chemotherapy and immunotherapy have been developed. Although these techniques have improved the quality of survival for many patients, the median survival following diagnosis and adjuvant treatment still remains only about a year. Recently, genetically engineered viruses for gene transduction and targeted cell killing have been used successfully in the experimental treatment of glioblastoma multiforme. We provide a review of the current and possible future therapies for malignant glioma with the belief that molecular biologic and genetic techniques offer the greatest hope of significantly altering the course of disease.     

Immunohistochemical Localization of Dopamine D Receptors in Rat Retina

We have localized the dopamine D1 receptor in rat retina using a subtype-specific monoclonal antibody. Immunolabelling can be detected in the inner and outer plexiform layers and in a number of cells in the inner nuclear layer. In the inner plexiform layer, labelled processes form four distinct horizontal bands and a series of patches. In order further to characterize the labelling pattern of the D₁ receptor antibody, double-labelling experiments were performed with antibodies against population-specific neuronal markers in the retina. Antibodies against tyrosine hydroxylase. choline acetyltransferase, calretinin, calbindin, the glutamate transporter GLT-I, protein kinase C, recoverin and parvalbumin were co-applied with the D, receptor antibody. With these cell markers we demonstrate that horizontal cells, at least three types of cone bipolar cells and a small number of amacrine cells are immunolabelled for the D1 receptor. In the inner plexiform layer, processes labelled by the D1 receptor antibody are co-stratified with processes labelled by the GLT-1 antibody. D₁ receptor-labelled processes are not co-localized with the processes of amacrine cells and ganglion cells labelled by antibodies against tyrosine hydroxylase, choline acetyltransferase or calretinin. Our results indicate that dopamine Dl receptors are localized predominantly to horizontal cells and cone bipolar cells. Furthermore, the spatial disparity between dopaminergic processes and the site of the majority of D1 receptors supports the idea that in the retina dopamine acts as a neuromodulator that diffuses through extracellular space. The localization of D1 receptors to a number of identified cell types enables future physiological work to be directed towards specific synaptic circuits within the retina.     

10-Hydrocinnamoyl- and 10-cinnamoyl-1,8-dihydroxy-9(10H)-anthracenones as inhibitors of leukotriene B4 biosynthesis and HaCaT cell growth

A series of 10-hydrocinnamoyl and 10-cinnamoyl-1,8-dihydroxy-9(10H)-anthracenones has been synthesized and evaluated as inhibitors of leukotriene B₄ (LTB₄) biosynthesis and as antiproliferative agents. In the hydrocinnamoyl series, compounds with phenolic hydroxyl groups were less potent inhibitors of LTB₄ biosynthesis than their non-phenolic analogs, suggesting that a nonspecific redox interaction between the compounds and the active site Fe³⁺ of 5-lipoxygenase or chelation of Fe³⁺ is not responsible for the observed activity. Compounds bearing a 10-cinnamoyl group were somewhat less active than their less rigid dihydrocinnamoyl congeners. Many compounds were also potent inhibitors of the growth of HaCaT cells with IC₅₀ values in the submicromolar range. Their activity in this assay was equivalent to that observed with the antipsoriatic anthralin, whereas unspecific cytotoxicity was largely reduced as documented by the activity of lactate dehydrogenase released from cytoplasm of keratinocytes.     

Mesenteric panniculitis: findings on CT, MRI, and angiography case report

The computed tomography (CT), magnetic resonance (MR), and angiographic features of a case of mesenteric panniculitis are presented. The MR characteristics of this rare disorder have not previously been reported. The value of MR in arriving at the preoperative diagnosis of this disorder is discussed.     

Transtracheal O2 insufflation (TOI) as an alternative method of ventilation during cardiopulmonary resuscitation

We examined the efficiency of continuous transtracheal O₂ insufflation (TOI) as a method of ventilation during cardiopulmonary resuscitation (CPR) in a canine model. The tip of the insufflation catheter was placed 1 cm above the carina. The effects of TOI at flow rates of 0.2, 0.5, and 1.01/kg per min during and after CPR were examined in dogs with induced ventricular fibrillation. During CPR, adequate oxygenation and ventilation were maintained with TOI at flow rates of 0.5 and 1.0 1/kg per min, but not at 0.21/kg per min. After CPR, TOI was adequate to maintain oxygenation, but not ventilation. TOI alone did not prevent post-CPR hypercarbia in successfully resuscitated animals. Still, this study suggests that TOI might be useful as a temporary measure for emergency ventilation during CPR, especially in situations such as upper airway abnormalities, when mask ventilation or endotracheal intubation is not feasible.     

Ruptures of arteriovenous malformations in children associated with trivial head trauma

Three cases of ruptured arteriovenous malformations (AVMs) in childhood associated with trivial head trauma are reported. These patients represented 12.5% of 25 consecutive patients with cerebral AVMs. The patients' ages ranged from 5 to 9 years; the patients were younger than their nontraumatic counterparts. The force of the trauma was presumably received in an anteroposterior or posteroanterior direction in all cases. Hematomas accompanying the AVMs were located in the subcortical area of the parietal or temporal lobe and angiographically their feeding arteries were all from the anterior cerebral artery or middle cerebral artery. The possible mechanisms for the rupture of AVMs after trivial head trauma are discussed.