Clinical significance of echocontrast enchancement in neurovascular diagnosis. Review of experience following a year of use

AIM OF THE STUDY: To evaluate the potential and limitations of echocontrast enhancement using Levovist in a non selected consecutive cohort of neurological patients with insufficient native ultrasound investigations. METHODS: In 91 patients an indication for echocontrast application was seen after an insufficient extracranial (n = 17), transtemporal (n = 54), and transforaminal (n = 20) Doppler- und color-coded Duplex sonography. Levovist was injected at a concentration of 400 mg/ml and 200-400 mg/ml for the transcranial and extracranial approach, respectively. The effect of the echocontrast enhancement was assessed semiquantitatively with respect to signal enhancement, imaging quality, and diagnostic confidence. RESULTS: In a total of 83 patients (91%) the signal enhancement led to a moderate to high imaging quality allowing to reach 67 definite neurovascular diagnoses (74%). In subgroup analysis, the amount of sufficiently confident examinations was significantly higher for the transtemporal and transforaminal (both 80%) than for the extracranial approach (47%). The latter was mostly due to artificial signals derived from adjacent neck vessels. CONCLUSION: Levovist constitutes a safe and highly effective diagnostic tool especially for the transtemporal and transforaminal neurosonographical imaging. By means of a differentiated application of echocontrast agents, its cost-effectiveness can be increased and the need for other potential invasive and expansive neuroimaging methods can be further reduced.     

Prospective evaluation of criteria for microbiological diagnosis of prosthetic-joint infection at revision arthroplasty. The OSIRIS Collaborative Study Group

A prospective study was performed to establish criteria for the microbiological diagnosis of prosthetic joint infection at elective revision arthroplasty. Patients were treated in a multidisciplinary unit dedicated to the management and study of musculoskeletal infection. Standard multiple samples of periprosthetic tissue were obtained at surgery, Gram stained, and cultured by direct and enrichment methods. With reference to histology as the criterion standard, sensitivities, specificities, and likelihood ratios (LRs) were calculated by using different cutoffs for the diagnosis of infection. We performed revisions on 334 patients over a 17-month period, of whom 297 were evaluable. The remaining 37 were excluded because histology results were unavailable or could not be interpreted due to underlying inflammatory joint disease. There were 41 infections, with only 65% of all samples sent from infected patients being culture positive, suggesting low numbers of bacteria in the samples taken. The isolation of an indistinguishable microorganism from three or more independent specimens was highly predictive of infection (sensitivity, 65%; specificity, 99.6%; LR, 168.6), while Gram staining was less useful (sensitivity, 12%; specificity, 98%; LR, 10). A simple mathematical model was developed to predict the performance of the diagnostic test. We recommend that five or six specimens be sent, that the cutoff for a definite diagnosis of infection be three or more operative specimens that yield an indistinguishable organism, and that because of its low level of sensitivity, Gram staining should be abandoned as a diagnostic tool at elective revision arthroplasty.     

Finding intron/exon splice junctions using INFO, INterruption Finder and Organizer

INFO, INterruption Finder and Organizer, has been used to find coding sequence intron-exon splice junctions in human and other DNA by comparing the six conceptual translations of the input DNA sequence with sequences in protein databanks using a similarity matrix and windowing algorithm. Similarities detected both delineate position of the gene and provide clues as to the function of the gene product. In addition to use of a standard similarity matrix and windowing algorithm, INFO uses two novel steps, the MiniLibrary and Reverse Sequence steps, to enhance identification of small exons and to improve precision of junction nucleotide delineation. Exons as small as about 30 bases can be reliably found, and > 90% of junctions are precisely identified when canonical splice junction information is used. With the MiniLibrary and Reverse Sequence steps, INFO parameters need not be optimized by the user. In comparative test runs using 19 human DNA sequences, INFO found 108 of 111 exons, with 0 reported false positives, compared with 111 exons and 51 false positives for BLASTX, 99 exons and 6 false positives for GRAIL II, 77 exons and 24 false positives for GeneMark, 61 exons and 9 false positives for GeneID, and 105 exons and 6 false positives for PROCRUSTES. The correlation coefficient for finding and positioning these 111 exons was greater than 98% for INFO. Comparable results were obtained in test runs of 13 nonhuman DNA sequences. INFO is applicable to DNA from any species, will become more robust as sequence databanks expand, and complements other heuristic approaches.     

NO/cGMP pathway is involved in exocrine secretion from rat pancreatic acinar cells

OBJECTIVE: To identify factors associated with the initiation of breast-feeding in a predominantly Puerto Rican population living in inner-city Hartford, Conn. DESIGN: Retrospective study of 144 Latino women (mean +/- standard deviation age = 26.3 +/- 5.7 years) with children at least 1 year old but younger than 6 years old (mean +/- standard deviation age = 3.0 +/- 1.2 years) at the time of the survey. Women were recruited from agencies sponsoring health programs for mothers and children. They were interviewed in their homes (69%) or at the Hispanic Health Council, Hartford, Conn (31%). SUBJECTS/SETTING: Low-income Latino women who had at least 1 preschooler at the time of the interview. The women lived in inner-city Hartford, and the overwhelming majority were Puerto Rican and received welfare assistance and food stamps. Seventy-eight percent of the women chose to be interviewed in Spanish; the other 22% were interviewed in English. STATISTICAL ANALYSES: Explanatory variables that related to breast-feeding initiation (P < or = .2) in bivariate chi 2 analyses were entered into a multivariate logistic regression model that was reduced using backward stepwise elimination procedures. RESULTS: Multivariate analyses indicated that breast-feeding the previous child, shorter length of maternal residence in the United States, not receiving prenatal bottle-feeding advice, more recent birth, and higher birth weight were positively associated with breast-feeding initiation. A major reason for choosing not to breast-feed was that women felt socially uncomfortable doing it. APPLICATIONS: Breast-feeding initiation was more likely in Latino women who received prenatal breast-feeding counselling and postpartum support. Mothers of low-birth-weight infants and women breast-feeding for the first time may need additional help. These findings can be used by programs like the Special Supplemental Nutrition Program for Women, Infants, and Children to increase breast-feeding initiation.     

Parathyroid hormone-related protein in patients with primary breast cancer and eucalcemia

Parathyroid hormone-related protein (PTHrP) is a causative factor of humoral hypercalcemia in breast cancer and other malignancies. We studied circulating PTHrP levels with three different immunoassays directed against different parts of the PTHrP molecule in 48 patients with breast cancer and eucalcemia. The methods used were: (a) a RIA with antibodies directed toward the midregion (63-78); (b) an immunofluorometric assay with two antibodies against 1-34 and 38-67; and (c) an immunoradiometric assay with antibodies against 1-40 and 1-72. Although most patients had PTHrP levels indistinguishable from normal when measured by all three methods, four patients had increased serum levels in the IFMA. PTHrP was detected by immunohistochemistry in tumors from nearly all patients. One patient with elevated PTHrP in plasma measured by IFMA showed intense staining of tumor by immunohistochemistry; the tumor was histologically graded as III (severe) and was the largest of all tumors in this patient group. The IFMA can identify increased serum PTHrP in some patients with breast cancer who are not hypercalcemic. This assay may be especially useful in screening patients for this tumor during a relative early phase of the disease.     

Design and evaluation of a device for measuring three-dimensional micromotions of press-fit femoral stem prostheses

Implant micromotion is considered to be a major factor in the loosening of cementless total hip replacements. Translational micromotion at the bone-implant interface generally occurs in all three spatial directions. Under physiological loading, the interfacial micromotion consists of a cyclic amplitude and changes in the mean, which, in the cranio-caudal direction, represents subsidence of the prosthesis. Existing measurement strategies, which are based on dial gauges, extensometers, LVDTs, hall-effect transducers or strain gauge techniques provide information about only one component of the general three-dimensional micromovement. Moreover, in the majority of the studies, the data are difficult to interpret due to the measured motions being composed of interfacial micromotion and femoral strains. A new transducer was designed that allows the accurate measurement of all three isolated components of micromotion. An optoelectronic approach, based on silicon position-sensitive detectors (PSD) in combination with high precision mechanical parts, was chosen. To exclude thermodrifts during long-term testing, a thermistor was integrated in the sensor. Validation experiments on a precision positioning table indicated the high precision and resolution of the developed sensors. Furthermore, in-vitro tests on a standard press-fit prosthesis demonstrated the easy handling and reliability of the system.     

Expression of an antigen homologous to the human CO17-1A/GA733 colon cancer antigen in animal tissues

The CO17-1A/GA733 antigen is associated with human carcinomas and some normal epithelial tissues. This antigen has shown promise as a target in approaches to passive and active immunotherapy of colorectal cancer. The relevance of animal models for studies of immunotherapy targeting this antigen in patients is dependent on the expression of the antigen on normal animal tissues. Immunohistoperoxidase staining with polyclonal rabbit antibodies to the human antigen revealed the human homologue on normal small intestine, colon and liver of mice, rats and non-human primates, whereas mouse monoclonal antibodies to the CO17-1A or GA733 epitopes on the human antigen did not detect the antigen. Polyclonal rabbit antibodies, elicited by the murine antigen homologue derived from recombinant baculovirus-infected insect cells, immunoprecipitated the antigen from mouse small intestine, colon, stomach, kidney and lung. The isolated recombinant murine protein bound polyclonal, but not monoclonal, antibodies to the human CO17-1A/GA733 antigen, and recombinant human antigen bound polyclonal antibodies elicited by the murine antigen homologue. Thus, the antigen homologue expressed by animal tissues is similar, but not identical, to the human antigen. These results have important implications for experimental active and passive immunotherapy targeting the CO17-1A/GA733 antigen.