Size-selective predation on groundwater bacteria by nanoflagellates in an organic-contaminated aquifer

Time series incubations were conducted to provide estimates for the size selectivities and rates of protistan grazing that may be occurring in a sandy, contaminated aquifer. The experiments involved four size classes of fluorescently labeled groundwater bacteria (FLB) and 2- to 3-microns-long nanoflagellates, primarily Spumella guttula (Ehrenberg) Kent, that were isolated from contaminated aquifer sediments (Cape Cod, Mass.). The greatest uptake and clearance rates (0.77 bacteria.flagellate-1.h-1 and 1.4 nl.flagellate-1.h-1, respectively) were observed for 0.8- to 1.5-microns-long FLB (0.21-microns3 average cell volume), which represent the fastest growing bacteria within the pore fluids of the contaminated aquifer sediments. The 19:1 to 67:1 volume ratios of nanoflagellate predators to preferred bacterial prey were in the lower end of the range commonly reported for other aquatic habitats. The grazing data suggest that the aquifer nanoflagellates can consume as much as 12 to 74% of the unattached bacterial community in 1 day and are likely to have a substantive effect upon bacterial degradation of organic groundwater contaminants.     

A novel super-potent neurokinin A receptor antagonist containing dehydroalanine

We report here the synthesis and preliminary pharmacological characterization of a novel Neurokinin A receptor antagonist. This molecule contains a dehydroalanine residue. It displays a high conformational rigidity and possesses very high activity. Its pharmacological properties as a neurokinin A receptor antagonist were assessed in in vitro experiments on rat vas deferens and were compared to those of Neuronorm and MEN10627.     

Development of endometrial cancer in women on estrogen and progestin hormone replacement therapy

The presenting symptoms, hormonal regimens, treatment modalities, tumor pathology, and follow-up of 25 women developing endometrial cancer while receiving postmenopausal estrogen and progestin therapy were investigated retrospectively. Patients were interviewed and hormone therapies were confirmed through medical records. Pathology specimens were reviewed. Patients received conjugated estrogens (n = 20) or another estrogen (n = 5). For those on conjugated estrogens, the mean daily dose was 0.68 mg, monthly duration was 24.9 days, and monthly dose was 17.0 mg. Women also received medroxyprogesterone acetate (n = 23) or norethindrone acetate (n = 2). The most common regimen was sequential medroxyprogesterone acetate, at a mean daily dose of 7.5 mg, monthly duration of 9.3 days, and monthly dose of 68 mg (mean duration = 5.7 years). Most tumors were low stage and grade, with few demonstrating grade 3 disease (n = 2) or greater than 50% myometrial invasion (n = 2). Twenty-three (92%) had disease limited to the uterus, while two had stage IIIA disease. All are alive and disease-free after a median follow-up of 26 months. Estrogen and progestin therapy does not prevent endometrial cancer in all patients. Women who developed this tumor on sequential therapy in general received less than the recommended guidelines for daily dosage and monthly duration of progestin. Most patients had early-stage and low-grade disease. Continued vigilance in the care of women on hormone replacement therapy is necessary even when combination therapy is prescribed.