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Biomedical subjects

J Northup

Publications and source records attributed to J Northup.

23 records · Page 2Linked to original sources
PubMed1990

G protein diversity is increased by associations with a variety of gamma subunits.

Guanine nucleotide-binding regulatory proteins (G proteins) are heterotrimeric proteins that transduce extracellular signals into intracellular changes. Functionally different G proteins have been identified by their different alpha subunits. The beta and gamma subunits have been assumed to constitute a common pool shared among various G protein heterotrimers. Two gamma subunits (gamma 3 and gamma 4) have been identified through molecular cloning; these are in addition to two subunits (gamma 1 and gamma 2) that were previously characterized. G proteins purified from a variety of mammalian tissues were examined with antisera specific to three of the gamma subunits. The antisera react with different gamma subunits associated with some of the purified G proteins but not all. This demonstrates that different G protein heterotrimers from different tissues carry structurally distinct members of the gamma-subunit family. Diversity in the structure of the gamma as well as the alpha and beta subunits and preferential associations between members of subunit families increase structural and possibly functional diversity of G proteins.

Amino Acid Sequence↗
PubMed1990

A component analysis of functional communication training across three topographies of severe behavior problems.

We evaluated the separate treatment components of a functional communication training program for 3 severely handicapped persons who each displayed different topographies of aberrant behavior. Following a functional analysis of maintaining conditions for inappropriate behavior (self-injury, stereotypy, aggression), each participant was trained to emit a communicative response that functioned to solicit reinforcement. For 2 participants, consequences (time-out or graduated guidance) for inappropriate behavior were also included. Treatment continued until the participants emitted the communicative response independently and no occurrences of inappropriate behavior were observed for at least two sessions. Following treatment, the separate contributions of the treatment components for communicative responding and for inappropriate behavior were evaluated with a reversal design. The results indicated that both sets of treatment components were necessary for maximal control over aberrant behavior. These results are discussed in relation to the efficiency, history, and control over reinforcement of both appropriate and inappropriate responses.

Behavior Therapy↗
PubMed1987

Reduction of malaria prevalence after introduction of Romanomermis culicivorax (Mermithidae: Nematoda) in larval Anopheles habitats in Colombia.

The worldwide resurgence of malaria has become a major public health problem. New methods of controlling the vectors of the disease are required, and we therefore studied the biological control of Anopheles albimanus by Romanomermis culicivorax in Colombia. The investigation was carried out in El Valle and Nuquí, two towns on the northern Pacific coast of the country. All of the mosquito larval habitats surrounding El Valle were seeded with the eggs and adults of R. culicivorax. The nematode established itself in the new habitat and recycled over 27 months. The larval population of A. albimanus, the only malarial vector detected in the two towns, decreased in El Valle. In contrast, no change in the larval populations of the vector was detected in ponds located near Nuquí, the untreated control town. A rapid and progressive decrease of the prevalence of malaria among schoolchildren in El Valle was observed during the 2-year evaluation period.

Animals↗
PubMed1985

Differential activation of yeast adenylate cyclase by wild-type and mutant RAS proteins.

In these experiments we demonstrate that purified RAS proteins, whether derived from the yeast RAS1 or RAS2 or the human H-ras genes, activate yeast adenylate cyclase in the presence of guanine nucleotides. These results confirm the prediction of earlier genetic and biochemical data and for the first time provide a complete biochemical assay for RAS protein function. Furthermore, we observe a biochemical difference between the RAS2 and RAS2val19 proteins in their ability to activate adenylate cyclase after preincubation with GTP.

Adenylyl Cyclases↗