The Master of Public Health program for Arkansas.

A unique Master of Public Health (MPH) program has been operating in Arkansas for the past two years. Developed by the faculty of the School of Public Health and Tropical Medicine at Tulane University Medical Center, it offers health professionals the opportunity to earn the MPH degree over a two-year period while remaining in their positions and communities. Most classes are taught on the campus of the University of Arkansas for Medical Sciences (UAMS) in Little Rock. Several courses have been offered by the faculty of the Health Services Administration program and Department of Biology at the University of Arkansas at Little Rock (UALR).

Measuring management potential.

This article provides a brief introduction to instruments that may be used to measure management potential in persons being considered for administrative positions. Instruments that measure aspects of leadership, power, personality, conflict, and organizational climate are discussed. An overview of each instrument is provided as well as data on the type of test, time to complete, cost, and purchasing information. While objective tests such as these are useful in assessing individual suitability for management positions, we advise that they be used prudently and judiciously.

Progesterone receptor A and B protein expression in human breast cancer.

The human progesterone receptor (PR) is a ligand-activated nuclear transcription factor which mediates progesterone action in target tissues. Two PR proteins, PR A (81-83 kDa) and PR B (116-120 kDa), have been described and different physiological activities ascribed to each on the basis of in vitro studies, suggesting that their ratio of expression may control progesterone responsiveness in target cells. Presence of PR in breast tumors is an important indicator of likely responsiveness to endocrine agents. However, the relative expression of PR A and B in breast cancer has not been described and its clinical significance has not been addressed. We have examined the expression of PR A and B in PR-positive breast tumors and found that while in most tumors PR A and B were expressed in similar amounts there was a broad overall distribution of PR A:B ratio which deviated significantly from a normal log distribution with tumors containing a PR A:B ration greater than 4 being over-represented in the group. Linear regression analysis revealed that high PR A:B ratios, in general, derived from a low concentration of PR B rather than high expression of PR A. PR A:B protein ratios were not correlated with the age of the patient or with total PR concentration. A third PR protein band (PR 78 kDa) was detected which comprised greater than 20% of total PR protein in a quarter of the tumor samples examined. The characteristics of tumors containing PR 78 kDa were not different from the overall group. In summary, in PR-positive breast tumors the ratio of expression of PR A and B proteins is close to unity as is seen in a number of other progestin target tissues. However, a significant proportion of tumors expressed very low levels of PR B and a consequently high PR A:B ration. Although the clinical consequence of this observation is not known, the in vitro findings that PR A may act as a repressor for PR B suggests that tumors containing primarily PR A may identify a subset of patients with low or aberrant response to endocrine agents.

Characterization of progesterone receptor A and B expression in human breast cancer.

The human progesterone receptor (PR) is a ligand-activated nuclear transcription factor that mediates progesterone action in target tissues. Two PR proteins, PR-A (M(r) 81,000-83,000) and PR-B (M(r) 116,000-120,000), have been described and different physiological activities ascribed to each on the basis of in vitro studies, suggesting that their ratio of expression may control progesterone responsiveness in target cells. Presence of PR in breast tumors is an important indicator of likely responsiveness to endocrine agents. However, the relative expression of PR-A and B in breast cancer has not been described, and its clinical significance has not been addressed. Expression of PR-A and B was measured by immunoblot analysis of 202 PR-positive human breast tumor cytosols. The ratio of expression of the two PR proteins (PR-A/B) ranged from 0.04 to 179.3. The median PR-A/B ratio was 1.26, and 61.4% of samples had PR-A/B ratios between 0 and 2. PR-A/B ratios deviated significantly from a normal log distribution; tumors containing a PR-A/B ratio greater than 4 were overrepresented in the group. Linear regression analysis revealed that high PR-A/B ratios, in general, derived from a low concentration of PR-B rather than high expression of PR-A. PR-A/B protein ratios were not correlated with the age of the patient or with total PR concentration. A third PR protein band (PR78kDa) was detected in a number of samples and comprised greater than 20% of total PR protein in 52 (25.7%) of the 202 tumor samples examined. The range or frequency distribution of PR-A/B ratios in samples containing PR78kDa was not different to the overall group. In summary, in PR-positive breast tumors, the ratio of expression of PR-A and B proteins is close to unity, as is seen in a number of other progestin target tissues. However, a significant proportion of tumors expressed very low levels of PR-B and a consequently high PR-A/B ratio. Although the clinical consequence of this observation is not known, the in vitro findings that PR-A may act as a repressor of PR-B suggest that tumors containing primarily PR-A may identify a subset of patients with low or aberrant response to endocrine agents.

Sequence and expression of the Mycobacterium leprae dnaJ gene.

Study of Mycobacterium leprae, the causative agent of leprosy, has been advanced by the isolation of genes encoding mycobacterial proteins including dnaK encoding the M. leprae 70 kDa heat shock protein. The sequence downstream from dnaK revealed a second open reading frame coding for a protein of 389 amino acids with a calculated molecular mass of 41.2 kDa. Sequence analysis demonstrated significant DNA homology with the dnaJ gene of other organisms. High amino acid sequence identity was obtained between the DnaJ protein of M. leprae and M. tuberculosis (89%) with significant divergence between the two occurring only at the C-terminal end. The expressed recombinant DnaJ protein had a molecular mass of 42 kDa.

The construction of Streptomyces cyaneus genomic libraries in Escherichia coli is dependent upon the use of Mcr-deficient strains.

Streptomyces cyaneus genomic DNA ligated into either lambda phage or plasmid vectors was very inefficiently cloned into standard Escherichia coli host strains. However, the same material could be efficiently cloned using Mcr-deficient E. coli strains. These results suggest that the S. cyaneus genome contains 5-methylcytosine residues, some of which occur within the recognition sequences of the E. coli Mcr restriction system.