Rifamycin in neonatal flavobacteria meningitis

Three newborn infants with meningitis due to Flavobacterium meningosepticum were treated with rifamycin administered parenterally and directly into the cerebral ventricles. Antibiotic concentrations of blood and cerebrospinal fluid (CSF) were monitored during treatment. There was rapid sterilization of the CSF after this antibiotic. Jaundice was the only toxicity noted. All 3 infants developed hydrocephalus and are shunt dependent. Two of them are otherwise free of neurological complications and are developing normally. Rifamycin is a safe and effective antibiotic in this form of neonatal meningitis.     

Mediastinal lesions in children: comparison of CT and MR

Magnetic resonance (MR) imaging was compared with computed tomography (CT) in 13 children with mediastinal abnormalities. CT and MR provided comparable information regarding the presence and size of the mediastinal lesions. The MR imaging technique that was most reliable in detecting a mass was a T1-weighted spin-echo pulse sequence. MR better discriminated mediastinal masses and enlarged nodes from vascular structures and was more sensitive than CT in detecting intraspinal extension. However, CT demonstrated calcification and bronchial abnormalities not seen on MR images. It is concluded that MR may be more helpful than CT in evaluating posterior mediastinal tumors, since there is a likelihood of intraspinal extension. In other cases, however, CT continues to be the procedure of choice to supplement plain radiography in children with suspected mediastinal neoplasms.     

Differing responses of globin and glycophorin gene expression to hemin in the human leukemia cell line K562

The human leukemia cell line, K562, produces embryonic and fetal hemoglobins and glycophorin A, proteins normally associated only with erythroid cells. Hemoglobin accumulation is enhanced by exposure of the cells to 0.05 mM hemin. We have examined K562 cells before and after exposure to hemin to determine whether expression of these erythroid proteins was shared by all cells or confined to specific subpopulations. Globin gene expression was examined by quantitation of globin mRNA sequences, using a 3H-globin cDNA molecular hybridization probe. Constitutive cells produced globin mRNA, the content of which was increased 3-4-fold by hemin. Cell-to-cell distribution of globin mRNA was determined by in situ hybridization of 3H-globin cDNA to constitutive and hemin-treated K562 cells. Virtually all cells in the culture exhibited grain counts above background, indicating globin gene expression by all cells, rather than a confined subpopulation. Virtually all hemin-treated cells had 3-5-fold higher grain counts, indicating uniformly increased globin gene expression. The glycophorin content of K562 cells was estimated by fluorescence-activated cell sorting (FACS) of cells labeled with fluorescein-labeled antiglycophorin antiserum. The vast majority of constitutive cells contained glycophorin, but exhibited to apparent increase in glycophorin accumulation after hemin exposure. Thus, glycophorin and globin genes exhibited differential responses to hemin. These differences could reflect normal differences in the patterns of specialized gene expression in stem cells. Alternatively, different aberrations of gene expression could be occurring in response to the determinants of the neoplastic properties of K562.     

Cloning and characterization of platelet factor 4 cDNA derived from a human erythroleukemic cell line

We report the isolation of a platelet factor 4 (PF4) cDNA clone from a lambda gt11 expression cDNA library which was derived from a human erythroleukemic (HEL) cell line. The sequence of the DNA insert includes the 3'-untranslated region, the entire amino acid coding region for the mature PF4 protein, and a 5' region containing coding information for an additional 18 amino acids. In addition, supplemental genomic DNA sequencing shows that the full-length leader sequence is 30 amino acids long plus an initial methionine and codes for a hydrophobic signal-like sequence which is probably involved in transmembrane transport. A single species mRNA of approximately 800 nucleotides was detected on blots of HEL cell poly(A) + RNA using a labeled PF4 cDNA probe. The human PF4 leader sequence shares some DNA, but no amino acid, homology with the 15 amino acids at the N-terminus of mature bovine PF4, suggesting rapid divergence in this region of PF4 between these two species. Sequence comparison of the coding regions of mature PF4 and gamma IP-10, a protein induced in a variety of cells following treatment with gamma-interferon, shows a corrected divergence of 76%. The divergence of a common ancestor protein into PF4 and gamma IP-10 may have accompanied the development of sophisticated immune and coagulation systems in vertebrates. The availability of cDNA and genomic DNA information for these genes in other species will be useful in studying the evolution of the coagulation and immune systems.     

Nonpalpable breast lesions: diagnosis with slightly overpenetrated screen-film mammography and hook wire-directed biopsy in 1,014 cases

Slightly overpenetrated screen-film mammography and hook wire-directed localization were used in 1,014 breast biopsies performed for nonpalpable, mammographically detected breast abnormalities. One lymphoma and 205 breast cancers (20%) were found; 115 breast cancers (56%) were noninvasive, and 90 (44%) were invasive. Mastectomy was performed in 69 breast cancers (34%); 136 (66%) were treated conservatively, 28 with biopsy only and 108 with lumpectomy, node dissection, and radiation therapy. All patients with noninvasive breast cancers treated with axillary dissection had uninvolved lymph nodes. Of the 90 invasive breast cancers, six (7%) had metastases to axillary nodes, which, to the authors' knowledge, is lower than percentages reported in other studies of wire-directed breast biopsies. The authors believe that the slightly overpenetrated technique is a valuable adjunct to screen-film mammography.     

Long-term mechanical stability of the impacted morselized graft-cement interface in total joint replacement: an experimental study in dogs

This experimental study compared the long-term (12 months) mechanical stability of the morselized graft-cement interface with the conventional bone-cement interface in both femoral bones of 10 adult dogs. For mechanical testing, three-point bending and push-out loading tests of composite bone-cement beams were used, while the incorporation of the graft was assessed by serial radiographs. Although the parameters fracture load and interface failure load showed inferior values in the specimens with a morselized graft-cement interface compared to those in specimens with a conventional bone-cement interface, no statistically significant differences were found between groups. Radiographic reconstitution of the lateral femoral cortex was observed in all animals at 3 months while signs of advanced remodeling were apparent at 6 months. These results indicate the long-term mechanical stability of the impacted morselized graft-cement interface is comparable to that of the conventional bone-cement interface created in primary total hip replacements provided the grafted area is protected from early heavy loading.     

The impact of the introduction of liquid based cytology on the variation in the proportion of inadequate samples between GP practices

Background  

Historically there has been a wide variation in the proportion of inadequate smears between general practices. Cervical screening in the UK is undergoing a fundamental change by moving from conventional to liquid based cytology (LBC). The main driver for this change has been a predicted reduction in the proportions of inadequate samples. This study investigates the effect of LBC on the variation in the proportion of inadequate samples between general practices using Shewhart's theory of variation and control charts.     

A mouse model for Luminal epithelial like ER positive subtype of human breast cancer

Background  

Generation of novel spontaneous ER positive mammary tumor animal model from heterozygous NIH nude mice.