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V Fiorenza

Publications and source records attributed to V Fiorenza.

4 recordsLinked to original sources
PubMed1987

Quantitative studies of the hepatitis B viral pre-S proteins: lack of correlation with the HBeAg status.

Radioimmunoassays for the determination of the relative amounts of hepatitus B viral pre-S proteins present in serum samples have been developed which utilize antibodies against synthetic peptides corresponding to the amino termini of these proteins. The assays were shown to be sensitive and specific. These assays have been used to examine hepatitis B surface antigen positive human plasma samples for the presence and relative amounts of pre-S proteins. Contrary to previously published data, it was found that there is no correlation between the presence of the pre-S proteins and the HBeAg status of the plasma, but that the ability to detect the pre-S proteins is only a function of the hepatitis surface antigen titre of the plasma. It is concluded that the pre-S proteins would not serve as a useful marker for active viral replication.

Amino Acid Sequence↗
PubMed1987

Small intestinal motility: normal and abnormal function.

This review outlines the properties and function of intestinal smooth muscle and the mechanisms that underlie contraction and relaxation. Both tonic and phasic (rhythmic) contraction are mediated by an increase in intracellular calcium. Phasic contraction is paced electrically by rhythmic changes in membrane potential (slow waves) which, upon reaching a threshold, lead to opening of membrane calcium channels and the entry of calcium into muscle cells; this inwardly directed calcium current or spike initiates a cascade of events resulting in contraction. Slow waves and spike potentials and, thus, phasic contraction, are influenced by neurotransmitters, hormones, and drugs. In circular muscle, these agents can also increase calcium by releasing it from intracellular stores, thus inducing tonic contraction. Ingestion of food initiates peristaltic propulsive activity which, in its rhythm, is superimposed on spontaneous phasic activity. The peristaltic reflex consists of two successive phases: relation of circular muscle distal to the distending bolus (descending relaxation) and contraction proximal to the bolus (ascending contraction). In-between meals, a different, slower pattern of muscle activity prevails, known as the migrating motor complex, which helps to maintain the lumen of the intestine free of contents. Improved understanding of normal muscle function is beginning to reflect itself in improved management of patients with motility disorders.

Eating↗