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K M Shih

Publications and source records attributed to K M Shih.

5 recordsLinked to original sources
PubMed2001

Two-dimensional electrophoretic analysis of Aedes aegypti mosquito fat body proteins during a gonotropic cycle.

We have used two-dimensional polyacrylamide gel electrophoresis to examine changes in the relative abundance and diversity of non-secreted proteins in Aedes aegypti fat body preparations during a reproductive cycle. Electrophoretic profiles were evaluated at four time points after eclosion, and at five time points after a blood meal. In contrast to the dramatic changes in abundance of specific secreted proteins such as vitellogenin, our results show that the complement of proteins internal to the fat body remains relatively constant during the mosquito reproductive cycle. Of the approximately 5-10% of proteins that do change in abundance, the majority undergo a dramatic decrease within 24 hours after eclosion.

Aedes↗
PubMed1978

Hetacillin (R)- and (S)-sulfoxides. Synthesis and structure-activity relationships.

Hetacillin was oxidized with m-chloroperbenzoic acid to give the corresponding (R)- and (S)-sulfoxides. Ozonization of hetacillin not only oxidized the sulfide but caused unexpected oxidation of the imidazolidine ring to a 2H-imidazoline. The biological spectrum showed the (R)-sulfoxide to be appreciably more active than the (S)-sulfoxide.

Animals↗
PubMedDate not supplied

Increased ribonucleotide reductase activity in hydroxyurea-resistant mosquito cells.

Hydroxyurea-resistant Aedes albopictus mosquito cells were selected by incremental exposure of unmutagenized cells to hydroxyurea concentrations ranging from 0.1 to 8 mM. Clonal populations that had become 40-fold more resistant to hydroxyurea than wild-type cells varied in morphology, and their growth rate decreased to a;45 h doubling time, relative to an 18 h doubling time in unselected cells. At this level of resistance, the cells remained diploid, with a modal chromosome number of 6. When labelled with (35)S[methionine/cysteine], clone HU1062, which grew in the presence of 8 mM hydroxyurea, overproduced a labeled protein with the approximate size of the 45,000 dalton M2 subunit of ribonucleotide reductase. Consistent with this observation, ribonucleotide reductase activity in HU-1062 cells was approximately 10-fold higher than in wild-type control cells. This is the first example of an hydroxyurea-resistant insect cell line. [Originally published in Volume 34, Archives of Insect Biochemistry and Physiology, 34:31-41 (1997).]

Aedes↗