National survey of mammographic facilities in 1985, 1988, and 1992

PURPOSE: To determine trends in mammography in the United States. MATERIALS AND METHODS: A sample of mammographic facilities was selected for each year of the Nationwide Evaluation of X-ray Trends. The same protocol was followed for the 1985, 1988, and 1992 surveys. Data were collected with use of the same imaging phantom for all three surveys and also with a different phantom in the 1988 and 1992 surveys. RESULTS: Of the 356 facilities surveyed in 1992, 59% claimed to be in compliance with the Health Care Financing Administration (HCFA) mammography requirements, 42% were accredited by the American College of Radiology (ACR), and 23% did not hold credentials from either the HCFA or the ACR. Since 1985, there has been a 34% improvement in acceptable phantom image quality score and a 20% decrease in the mean glandular dose. CONCLUSION: Mammography as practiced today is essentially a screen-film technique. Mammographic phantom image quality has improved considerably. The overall mean glandular dose has decreased primarily because of the elimination of xeroradiography.     

The organization and animal-vegetal asymmetry of cytokeratin filaments in stage VI Xenopus oocytes is dependent upon F-actin and microtubules

Confocal immunofluorescence microscopy with anti-cytokeratin antibodies revealed a continuous and polarized network of cytokeratin (CK) filaments in the cortex of stage VI Xenopus oocytes. In the animal cortex, CK filaments formed a dense meshwork that both was thicker and exhibited a finer mesh than the network of CK filaments previously observed in the vegetal cortex (Klymkowsky et al., 1987). CK filaments first appeared in association with germinal vesicle (GV) and mitochondrial mass (MM) of oocytes in early mid stage I, indicating that CK filaments are the last of the three cytoskeletal networks to be assembled. By late stage I, CK filaments formed complex networks surrounding the GV, surrounding and penetrating the MM, and linking these networks to a meshwork of CK filaments in the oocyte cortex. During stage III-early IV, CK filaments formed a highly interconnected, apparently unpolarized, radial array linking the perinuclear and cortical CK filament networks. Polarization of the CK filament network was observed during mid stage IV-stage V, as first the animal, then the vegetal CK filament networks adopted the organization characteristic of stage VI oocytes. Treatment of stage VI oocytes with cytochalasin B disrupted the organization of both cortical and cytoplasmic CK filaments, releasing CK filaments from the oocyte cortex and inducing formation of numerous cytoplasmic CK filament aggregates. CB also disrupted the organization of cytoplasmic microtubules (MTs) in stage VI oocytes. Disassembly of oocyte MTs with nocodazole resulted in loss of the characteristic A-V polarity of the cortical CK filament network. In contrast, disruption of cytoplasmic CK filaments by microinjection of anti-CK antibodies had no apparent effect on cytoplasmic or MT organization. We propose a model in which the organization and polarization of the cortical network of CK filaments in stage VI Xenopus oocytes are dependent upon a hierarchy of interactions with actin filaments and microtubules.     

Secobarbital in humans discriminating triazolam under two-response and novel-response procedures

The percentage of long-term survivors after intensive chemotherapy and the outcome of MDS patients who achieve partial remission (PR) with intensive chemotherapy (IC) are not known. Between 1981 and 1996 we treated 99 patients with de novo MDS who had high-risk MDS or progression to AML, with IC. 41 (41%) achieved CR, 16 (16%) achieved partial remission (PR), 26 (26%) had failure, and 16 (16%) died in aplasia. Eight of the patients who achieved CR were autografted, three were allografted and the remaining cases received moderate consolidation chemotherapy. After IC, the 16 PR patients fulfilled the criteria for RA in 15 cases and CMML in one case. Median PR duration was 17 months, and three PR were > 3 years (39, 50+, 82+ months). Median actuarial survival of patients who achieved PR and CR was 18 months and 20 months from the onset of IC, respectively (difference not significant). Of the 71 patients treated before 1993, with sufficient follow-up, 10 (14%) had survived > 4 years (long-term survivors). Four of them were alive in first CR after 49+ to 110+ months and probably cured, two were alive in PR after 50+ and 82+ months and four had died after 49-78 months. Long-term survivors were characterized by a significantly higher incidence of RAEB-T at diagnosis, and with normal or favourable cytogenetic findings. In patients with RAEB-T at diagnosis included before 1993, 8/23 (35%) cases who had no unfavourable karyotype had survived > 4 years. Our findings suggest that MDS patients who achieve PR with IC, and not only those who achieve CR, can benefit from this type of treatment. The percentage of long-term survivors remains low, however, and is almost restricted to patients with RAEB-T at diagnosis and no unfavourable karyotype.     

Comparison of three monoclonal antibody pools for the detection of respiratory viral antigen in respiratory secretions

The aim of this study was to compare the sensitivities of commercial monoclonal antibody pools to be used as an initial rapid screen for detection of viral antigens in respiratory secretions. The availability of commercial monoclonal antibodies has dramatically improved the detection of viruses by immunofluorescence techniques in exfoliated cells obtained from respiratory secretions. Several companies have recently introduced monoclonal antibody pools to detect the presence of respiratory viruses in a single preparation. Ninety-four stored slide preparations that had previously been examined by individual monoclonal antibodies were tested using three commercial monoclonal antibody pools produced by Sanofi (UK), Dako (UK), and Quadratech (UK). These monoclonal antibody pools had a sensitivity of 79.6%, 90.9%, and 100%, respectively, when compared with the original results. The overall intensity of immunofluorescence was also examined.     

Cryptosporidium Log-inactivation with Ozone Using Effluent CT10, Geometric Mean CT10, Extended Integrated CT10 and Extended CSTR Calculations

The draft Long-Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) contains Cryptosporidium log-inactivation CT tables (ozone-in-water concentration [residual], “C” times contact time, T). Depending on water temperature, Cryptosporidium CT values that are listed are 15 to 25 times greater than CT values for equivalent Giardia log-inactivation credit. The elevated operating dose required for Cryptosporidium log-inactivation credit has the potential to increase disinfection by-product (DBP) formation (e.g., bromate). Calculating CT value accurately will minimize ozone dose, which will decrease operating cost and lower DBP formation, and at the same time maintain disinfection protection through implementation of scientifically based safety factors. Various methods are available for calculating CT value. The method chosen depends largely on the available information concerning ozone residual characteristics and hydrodynamic features of the ozone contactor, plus local regulatory requirements. Four methods are discussed in this paper. Each method can be used to calculate Giardia, virus, and Cryptosporidium log-inactivation credit.     

Nanostructured polymer blends: Synthesis and structure

Nanostructured polymer blends prepared via anionic ring opening polymerizations of cyclic monomers in the presence of a pre-made polymer melt exhibit a number of special properties over traditional polymer blends and homopolymers. Here, we report on a simple and versatile method of in situ polymerization of macrocyclic carbonates in the presence of a maleic anhydride polypropylene (mPP) matrix and a surface-active compatibilizer (i.e. PC grafted onto a mPP backbone generated in situ) to yield a micro- and nanostructured polymer blends consisting of a polycarbonate (PC) minor phase, and a polypropylene (PP) major phase. By varying the processing conditions and concentration of the macrocyclic carbonate it was possible to reduce the size of the PC dispersions to an average minor diameter of 150 nm. NMR and TEM characterizations indicate that the PC dispersions do not influence crystal content in the PP phase. Overall, the results point to a simple strategy and versatile route to new polymeric materials with enhanced benefits.     

Another false alarm? apnea monitor activation in a Neonatal Intensive Care Unit graduate

Neonatal emergencies have become more common as increasingly sophisticated Neonatal Intensive Care Units graduate lower birth-weight babies born at younger gestational ages. These patients present a number of challenges to emergency physicians. They are often discharged with apnea monitors, which generate a high number of false alarms. Neonatal Intensive Care Unit graduates, however, are predisposed to a number of conditions that can result in true episodes of apnea. We present such a case and will discuss the unusual underlying cause of apnea, the utility of apnea monitors, and the need for emergency physicians to be prepared to evaluate and treat these potentially complicated patients.