Phenotypic characterization, cellular fatty acid composition, and DNA relatedness of aerococci and comparison to related genera.

Aerococci can be misidentified as streptococci, enterococci, pediococci, lactococci, or leuconostocs. To distinguish the genus and determine if another species is needed in the present taxon, we analyzed 37 aerococci for cellular fatty acids and compared them with 377 strains of gram-positive cocci, including the species type strains from each of the related genera. The cellular fatty acid profile of aerococci was distinguishable from other genera. Two relatively novel fatty acids found in the aerococci were identified as C16:1 omega 9c and C16:1 omega 9t. Eleven strains of aerococci (including a strain originally identified as "Gaffkya" species) were chosen for DNA-DNA reassociation studies with the type strain Aerococcus viridans ATCC 11563; DNAs from eight of these strains were more than 75% related to the type strain and had 1 to 4% divergence in related sequences. The remaining three strains were 60 to 70% related to the type strain, had 7 to 11.5% divergence, and may represent a second species, Aerococcus genospecies 2. beta-Glucuronidase, alpha-galactosidase, and beta-galactosidase were useful in characterizing the aerococci.     

Therapy for hepatic fibrosis

Although there is no established therapy for the fibrogenesis of hepatic cirrhosis, many potential therapies are now emerging. The requirements for the "perfect therapy" for hepatic fibrosis can be listed: (1) the pharmacologic agent should be active only in the liver; (2) its effect should be specific for collagen (or another critical extracellular matrix component); and (3) it should not be toxic. To date no agents fulfill these criteria. Of the agents we reviewed, only colchicine appears sufficiently safe for use outside of controlled clinical trials for cirrhotic patients whose underlying disease is not otherwise treatable. However, confirmation of the efficacy of colchicine in additional well-controlled clinical trials is still required. Agents such as collagen propeptides require extensive in vitro development, while trials in animal models are required for prolyl 4-hydroxylase inhibitors, proline analogues, and prostaglandins. For more developed agents, such as malotilate and gamma-interferon, there is now a need for well-designed long-term clinical trials.     

Going up river with Sue Scholar and John D. Dollarsense

Going upstream to find out and do something about drowning children one finds Knowledge and Research Land and Public Policy Land separated by a widening river. Our fearless hero, Tom Swift, explores with Sue Scholar what is known about prevention and then with John Dollarsense what those in power and control of resources would support. For example one must weigh the increasing research on what makes early childhood experiences helpful to children with the now needs of children on alcohol and drugs, children living in abusive homes and teenage pregnancy. Several specific courses of action are suggested as possible ways of building a bridge between knowledge producers and public policy makers.     

The relative biological effectiveness of photon radiation from encapsulated iodine-125, assessed in cells of human origin: I. Normal diploid fibroblasts

The relative biological effectiveness (RBE) of photon radiation from encapsulated Iodine-125 "seed" sources has not previously been investigated in human cells. The RBE of 125I photons relative to 137Cs gamma rays was examined in normal diploid human fibroblasts derived from lung and skin. The cells were irradiated in plateau phase using a specially designed incubator-irradiator which permitted simultaneous 125I and 137Cs irradiation. The cells were irradiated at various dose rates ranging from 7 to 70 cGy/hr. Dosimetry was performed using Monte Carlo computer calculations to simulate the 125I irradiations and the exposure-standardization measurements made by the U.S. National Bureau of Standards which are the basis for the specified strengths of 125I seeds. Simulation of the exposure standardization measurements revealed systematic errors due to the unrecognized presence of low-energy fluorescence X rays. The specified activity of the type of seeds used for this study (high-activity, no radiographic marker) was found to be too high by more than 10%. The RBE of 125I assessed with both lung fibroblast lines was found to be 1.2 and was 1.3 for the skin fibroblasts. The RBE did not change over the range of dose rates tested. In fact, for both 125I and 137Cs, the dose response curves did not change with dose rate over the range tested, implying full repair of sublethal damage at dose rates below 70 cGy/hr in these non-dividing cells.     

Limited sensitivity of iodine-123-2-hydroxy-3-iodo-6-methoxy-N-[(1-ethyl-2-pyrrolidinyl)methyl ] benzamide whole-body scintigraphy in patients with malignant melanoma: a comparison with thallium-201 imaging

The aim of this prospective study was to assess the diagnostic value of iodine-123-2-hydroxy-3-iodo-6-methoxy-N-[(1-ethyl-2-pyrrolidinyl)methyl] benzamide (IBZM) whole-body imaging in comparison to thallium-201 scintigraphy in patients with metastatic malignant melanoma. Ten patients with suspected or proven locoregional metastases of malignant melanoma underwent whole-body scintigraphy both with 201Tl and 123I-IBZM prior to scheduled surgery. Whole-body scans and planar scintigrams were acquired at 5 min and 30 min after injection of 100 MBq 201Tl and at 10 min, 2 h, 4 h and 24 h after injection of 185 MBq 123I-IBZM. Ten out of 12 melanoma metastases, both melanotic and amelanotic as proven histologically, were detected by 201Tl with a sensitivity of 83%. 123I-IBZM showed tracer uptake only in 3 melanotic metastases (sensitivity: 25%) with a maximum tumor-to-background ratio within 4 h, while none of the amelanotic metastases was IBZM-positive. All lesions localized by 123I-IBZM showed tracer uptake of 201Tl as well, while 201Tl-negative lesions were also negative with IBZM. Because of the poor results of IBZM, the study was terminated after an interim evaluation of 10 patients. 123I-IBZM is a tracer with only moderate sensitivity in melanotic melanoma lesions, suggesting that this method has no clinical value as a routine investigation in melanoma patients. In comparison, our previous results with 201Tl whole-body scintigraphy yielded a significantly higher sensitivity of about 80% in patients with locoregional melanoma metastases and may thus offer considerable potential in non-PET melanoma imaging.