Epithelial antibiotics induced at sites of inflammation.

The role of antimicrobial peptides in epithelial defense is not fully understood. An epithelial beta-defensin, lingual antimicrobial peptide (LAP), was isolated from bovine tongue and the corresponding complementary DNA cloned. LAP showed a broad spectrum of antibacterial and antifungal activities. LAP messenger RNA abundance was markedly increased in the epithelium surrounding naturally occurring tongue lesions. This increase coincided with the cellular hallmarks of acute and chronic inflammation in the underlying lamina propria, supporting a role for epithelial antimicrobial peptides as integral components of the inflammatory response.

Characterization of membrane-bound and soluble D2 receptors in canine caudate using [125I]IBZM.

(S)-(-)-3-iodo-2-hydroxy-6-methoxy-N-[(1-ethyl-2-pyrrolidinyl) methyl]benzamide (IBZM) was shown to be a high-affinity antagonist selective for the D2 subtype of dopamine receptor. Binding sites for the radioligand [125I]IBZM were characterized with membranes and digitonin-solubilized extracts of canine caudate enriched by chromatography on heparin-agarose. Nonspecific binding, defined using 2 microM (+)-butaclamol, was less than 10% of the total ligand bound at the Kd of the receptor for [125I]IBZM. Direct binding, competition and kinetic experiments indicated that [125I]IBZM bound to a homogeneous population of binding sites. The rank order of potency for inhibition of the binding of [125I]IBZM by antagonists and agonists was found to be consistent with the pharmacological profile expected of a D2 receptor. The affinities of [125I]IBZM for membrane-associated and detergent-solubilized binding sites were essentially identical (Kd congruent to 0.4 nM). This result contrasts with findings obtained in studies with [3H]spiroperidol, where a marked decrease in the affinity of the receptor for the ligand has been observed during detergent solubilization and purification of the receptor. The high selectivity, nanomolar affinity and high specific activity of [125I]IBZM and the results obtained in studies with detergent extracts suggest that [125I]IBZM will be a particularly useful ligand for studies of D2 receptors in the presence of detergents.

Human choroid plexus cells can be latently infected with human immunodeficiency virus.

The human immunodeficiency virus (HIV) penetrates the central nervous system, particularly the cerebrospinal fluid, early in the course of HIV infection, and may cause a progressive encephalopathy in patients prior to the development of the acquired immunodeficiency syndrome. Neither the specific mechanism for penetration of the virus into the central nervous system nor the pathophysiological basis for these abnormalities is well understood. We cultured cells from the choroid plexus of 3 individuals who died of causes unrelated to the acquired immunodeficiency syndrome and demonstrated that these cells can be infected with type 1 HIV. Infection of cells of the choroid plexus may provide an initial route of entry of HIV into the cerebrospinal fluid and, together with the macrophage, a route of entry into the brain.

Hypertension in neonatal hyperthyroidism.

Hypertension has only recently been reported in neonatal hyperthyroidism. We describe three children with hypertension as a prominent part of the syndrome. Antihypertensive therapy alone was ineffective in controlling elevated BP. All patients showed gradual resolution of hypertension once a euthyroid state was achieved.