Alexander M. B. Johns

Learn More
We previously demonstrated that 17beta hydroxysteroid dehydrogenase type 2, the enzyme that inactivates estradiol to estrone, is expressed in luteal eutopic endometrium in response to progesterone but not in simultaneously biopsied peritoneal endometriotic tissue. This molecular evidence of progesterone resistance, together with the clinical observation of(More)
Aberrant aromatase expression in stromal cells of endometriosis gives rise to conversion of circulating androstenedione to estrone in this tissue, whereas aromatase expression is absent in the eutopic endometrium. In this study, we initially demonstrated by Northern blotting transcripts of the reductive 17beta-hydroxysteroid dehydrogenase (17betaHSD) type(More)
The conversion of C19 steroids to estrogens occurs in a number of tissues, such as the ovary and placenta, and is catalyzed by aromatase P450 (P450arom; the product of the CYP19 gene). P450arom expression has also been detected in a number of uterine tumors, such as leiomyomas and endometrial cancer. On the other hand, P450arom expression was undetectable(More)
Estrogen is the most important known factor that stimulates the growth of endometriosis. Estrogen delivery to endometriotic implants was classically viewed to be only via the circulating blood in an endocrine fashion. We recently uncovered an autocrine positive feedback mechanism, which favored the continuous production of estrogen and prostaglandin (PG)E2(More)
Rhodotorula (Rhodosporidium) toruloides is an oleaginous yeast with great biotechnological potential, capable of accumulating lipid up to 70% of its dry biomass, and of carotenoid biosynthesis. However, few molecular genetic tools are available for manipulation of this basidiomycete yeast and its high genomic GC content can make routine cloning difficult.(More)
Blood samples were obtained from school entrants whose primary immunization schedule had consisted of three doses of DT or DTP vaccine and three doses of OPV all given before the age of 8 months. The sera were separated and assayed for diphtheria antitoxin, tetanus antitoxin and antibodies to the three serotypes of poliovirus. The results of the assays(More)
BACKGROUND The exacting nutritional requirements and complicated life cycles of parasites mean that they are not always amenable to high-throughput drug screening using automated procedures. Therefore, we have engineered the yeast Saccharomyces cerevisiae to act as a surrogate for expressing anti-parasitic targets from a range of biomedically important(More)
595 Background: Neoadjuvant (Neo) chemotherapy (CT) with trastuzumab (H) improves pathologic complete response (pCR) rate for HER2+ breast cancer. Dose-dense regimens improve outcome in the adjuvant setting but have not been fully evaluated as preoperative therapy. We designed this regimen to utilize full doses of active agents including docetaxel (T) and H(More)
e11087 Background: The standard approach to HR+ MBC is sequential single endocrine agents, but in the current era of adjuvant AI therapy, alternatives to AIs for first line MBC endocrine treatment are desirable. We designed this trial to assess the feasibility, safety and efficacy of a combined chemoendocrine approach with continuous low dose oral(More)
10695 Background: Aromatase inhibitors (AIs) are recommended as first line agents or after tamoxifen (T) as extended adjuvant therapy in hormone receptor positive ESBC. Little is known about adherence, adverse events, toxicity, duration of therapy, or change in agents in the community setting. Disparities between actual usage and clinical guideline(More)
  • 1