Abbott prism: a multichannel heterogeneous chemiluminescence immunoassay analyzer

We describe a multichannel heterogeneous immunoassay analyzer in which a sample is split between disposable reaction trays in a group of linear tracks. The system's pipettor uses noninvasive sensing of the sample volume and disposable pipet tips. Each assay track has (a) a conveyor belt for moving reaction trays to predetermined functional stations, (b) temperature-controlled tunnels, (c) noncontact transfer of the reaction mixture between incubation and detection wells, and (d) single-photon counting to detect a chemiluminescence (CL) signal from the captured immunochemical product. A novel disposable reaction tray, with separate reaction and detection wells and self-contained fluid removal, is used in conjunction with the transfer device on the track to produce a carryover-free system. The linear immunoassay track has nine predetermined positions for performing individual assay steps. Assay step sequence and timing is selected by changing the location of the assay modules between these predetermined positions. The assay methodology, a combination of microparticle capture and direct detection of a CL signal on a porous matrix, offers excellent sensitivity, specificity, and ease of automation. Immunoassay configurations have been tested for hepatitis B surface antigen and for antibodies to hepatitis B core antigen, hepatitis C virus, human immunodeficiency virus I and II, and human T-cell leukemia virus I and II.

Development of a strategy to encourage attendance for screening mammography

The present study describes a method for the data-driven structuring of interventions to increase participation in screening mammography. We interviewed 668 randomly selected women from the target population of an Australian pilot screening mammography program before this Program commenced. The aims of the study were to use cross-sectional data to determine factors which predicted women's intentions regarding attendance at the Program, and on the basis of these results to develop optimal strategies to encourage attendances. Of the sample, 64% said they intended to go to the Program, while 11% were unsure. A number of variables were significantly associated with intention and regression analysis was used to determine the best model for predicting intention. Ten variables entered the final regression model: the intensity of thought about getting breast cancer; a belief that early detection is extremely desirable and that screening mammograms are accurate; having had a Pap test within the last 2 years; a belief that health is controlled by chance; perceived ease of getting to the hospital; subjective familiarity with the hospital location of the Program; age; having heard about screening mammography; and a feeling of personal susceptibility to breast cancer. This model explained 20% of the variance in intention to have a mammogram (R 2 = 0.20, F(10,492) = 12.08; P less than 0.0001). The practical applications of these findings are discussed in this report. It is recommended that if a campaign were to concentrate on changing women's perceptions on the dimensions found to be significantly associated with intention, then it would have maximum chance of encouraging attendance amongst women in the target population. The strategies we have developed based on these findings are discussed in this paper.

Reaction tray and noncontact transfer method for heterogeneous chemiluminescence immunoassays

We describe a reaction tray for a heterogeneous chemiluminescence (CL) immunoassay having the following features: separate sample incubation and signal detection wells; a design that allows for noncontact transfer of the reaction mixture from incubation wells to detection wells; surface features to mate with a detector and create a light-tight seal for CL detection; and self-contained means for liquid removal. The reaction mixture is transferred by injecting a wash solution from a group of nozzles into the incubation well. Quantitative transfer of microparticles (transfer efficiencies greater than 95% and CV less than 5%) is achieved by injecting two 300-microL pulses of transfer solution at a rate of 2.1 m/s. The performance of the tray and method of transfer is tested by determining the precision of CL signal for a sample containing a concentration of anti-hepatitis B core antigen (anti-HBc) or hepatitis B surface antigen (HBsAg) close to the cutoff value for the assay.

Abbott prism: a multichannel heterogeneous chemiluminescence immunoassay analyzer

We describe a multichannel heterogeneous immunoassay analyzer in which a sample is split between disposable reaction trays in a group of linear tracks. The system's pipettor uses noninvasive sensing of the sample volume and disposable pipet tips. Each assay track has (a) a conveyor belt for moving reaction trays to predetermined functional stations, (b) temperature-controlled tunnels, (c) noncontact transfer of the reaction mixture between incubation and detection wells, and (d) single-photon counting to detect a chemiluminescence (CL) signal from the captured immunochemical product. A novel disposable reaction tray, with separate reaction and detection wells and self-contained fluid removal, is used in conjunction with the transfer device on the track to produce a carryover-free system. The linear immunoassay track has nine predetermined positions for performing individual assay steps. Assay step sequence and timing is selected by changing the location of the assay modules between these predetermined positions. The assay methodology, a combination of microparticle capture and direct detection of a CL signal on a porous matrix, offers excellent sensitivity, specificity, and ease of automation. Immunoassay configurations have been tested for hepatitis B surface antigen and for antibodies to hepatitis B core antigen, hepatitis C virus, human immunodeficiency virus I and II, and human T-cell leukemia virus I and II.

Lid flora in blepharitis

The microbiologic evaluations of 332 consecutive patients with the primary diagnosis of chronic blepharitis were reviewed and compared to those of 160 control patients. The most commonly isolated organisms from lids with blepharitis were Staphylococcus epidermidis (95.8%), Propronibacterium acnes (92.8%), Corynebacterium sp. (76.8%), Acinetobacter sp. (11.4%), and Staphylococcus aureus (10.5%). Compared to controls, S. epidermidis (p less than 0.01), P. acnes (p less than 0.02), and Corynebacterium sp. (p less than 0.001) were present significantly more often. S. aureus and the isolation of more than one microbial species were not more common in blepharitis patients. Quantitatively, heavy growth, by total and individual species, was significantly more common in blepharitis patients (total, p less than 0.001; S. epidermidis, p less than 0.001, P. acnes, p less than 0.001). These data demonstrate that patients with blepharitis are more likely to have normal skin bacteria on their lids and in greater quantities than nonblepharitis patients.

Patterns of out-patients non-steroidal anti-inflammatory drug prescribing in two teaching hospital rheumatology units--implications for post-marketing surveillance

Patterns of prescriptions or recommendations for non-steroidal anti-inflammatory drugs (NSAIDs) were examined in the out-patient departments of two teaching hospital rheumatology units [The General Infirmary, Leeds (n = 140), and Musgrave Park Hospital, Belfast (n = 77)]. In both units four drugs accounted for over 80% of prescriptions/recommendations (diclofenac, indomethacin, ibuprofen and naproxen in Leeds and flurbiprofen, nabumetone, ibuprofen and diclofenac in Belfast). In Leeds patients with pre-existing upper gastrointestinal problems were more likely to receive diclofenac whereas in Belfast they were more likely to receive nabumetone or ibuprofen. In Leeds, patients who received indomethacin tended to be young males with seronegative arthritis. These differences between drugs and between centres could have important implications for cost, design and interpretation of studies of post-marketing surveillance.

Bilateral mammary artery bypass and sternal dehiscence. A favorable outcome

The efficacy of mammary artery bypass for coronary artery disease has been well established. The present retrospective series of consecutive patients was scrutinized to assess the incidence of sternal dehiscence following myocardial revascularization using the right and left internal mammary arteries. For comparison, the consecutive group of patients undergoing myocardial revascularization with unilateral internal mammary artery bypass was analyzed for similar sternal complications. In a consecutive series of patients, 277 patients underwent myocardial revascularization using the right and left internal mammary arteries for bypass. The overall operative mortality in this group of patients was 0.722 per cent. In this group there was an overall incidence of seven sternal dehiscences, both partial and complete for an incidence of 2.52 per cent. Upon analysis, it was shown that the female sex and diabetes were the conditions that most likely predisposed to the occurrence of sternal dehiscence whether partial or complete. For comparison, a consecutive group of 413 patients were analyzed for similar demographic data and results. The overall operative mortality in this group was 1.21 per cent. The overall incidence of sternal dehiscence both partial and complete, was 0.484 per cent. Both instances of sternal dehiscence occurred in diabetic patients and the data indicates, as in the bilateral internal mammary artery group, the presence of diabetes predisposed to the occurrence of this complication. The low overall incidence of sternal dehiscence in the expanded use of the mammary arteries should not deter the surgeon from aggressive use of the mammary arteries. One should use caution, however, in using bilateral mammary artery grafts in diabetics, women, and to a lesser extent, patients more than 70 years of age.

Nucleotide sequence of the avian influenza A/Mallard/NY/6750/78 virus polymerase genes

The avian influenza A/Mallard/NY/6750/78 virus is currently being evaluated as a donor of attenuating genes in the construction of live avian-human influenza A reassortant virus vaccines for use in humans. We determined the nucleotide sequences of the three polymerase gene segments of this virus. This completes the nucleotide sequence of the six transferrable genes of the avian donor virus. Comparison of the nucleotide and deduced amino acid sequences of the non-glycoprotein genes of the avian A/Mallard/78 virus with representative avian and human influenza A viruses suggests that the PB1 gene of H2N2 subtype human influenza A viruses may have been derived from a non-human, possibly avian influenza A virus by genetic reassortment. In addition, several regions of conserved amino acids with potential functional significance were identified in the deduced amino acid sequences of the polymerase proteins.

Molecular cloning and characterization of the novel, human complement-associated protein, SP-40,40: a link between the complement and reproductive systems

The cDNA sequence encoding the human complement-associated protein, SP-40,40, is reported. The two chains of SP-40,40 are coded in a single open reading frame on the same mRNA molecule, indicating the existence of a biosynthetic precursor protein which matures post-synthetically by the proteolysis of at least one peptide bond. The precursor is preceded by a signal sequence for vectorial export and contains six N-linked glycosylation sites distributed equally between the two chains of the structure. The sequence of the SP-40,40 precursor bears a 77% identity to a rat sulphated glycoprotein-2 (SGP-2) which is the major secreted product of Sertoli cells. The presence of SP-40,40 within human seminal plasma at levels comparable to those in serum was demonstrated, indicating that SP-40,40 and SGP-2 are serum and seminal forms of the same protein. A sequence of 23 amino acids within the beta-chain of SP-40,40 exhibited significant homology to corresponding segments located within complement components C7, C8 and C9. The short cysteine-containing motif represented the only evidence of a possible vestigial relationship between SP-40,40 and other complement components. The precise role of SP-40,40 is not known in either blood or semen but the present findings document an intriguing link between the immune and the reproductive systems.

Regulation of gene expression at the translational level. The rescue factor reverses thermosensitive protein synthesis in N4316, a conditionally-lethal mutant of Escherichia coli defective in translation

Extracts of the conditionally-lethal mutant Escherichia coli N4316 are defective in a newly described translation factor, the rescue protein. We have analyzed the in vitro translation products of this mutant by gel electrophoresis during normal and arrested synthesis at the permissive and non-permissive temperatures. Translation programmed with MS2 bacteriophage RNA at the non-permissive temperature results in highly reduced synthesis of the coat protein with no detectable levels of the maturation and replicase products. Thus the relative number of copies of proteins synthesized by the ribosomes is altered in this mutant. In addition, there is mistranslation of the coat gene which results in the overproduction of the phage encoded no. 7 protein. Aberrant synthesis is also reflected in the increased read-through of termination codons during synthesis directed by phage RNAs harbouring amber mutations in the coat cistron. The rescue protein, purified from the parental strain, is able to complement the thermosensitive defect and restore proper synthesis. Biochemical characterization of the defect in the absence of rescue shows no detectable deficiency in the extent of initiation complex formation in reactions inhibited with sparsomycin. Peptidyltransferase is fully active as judged by the kinetics of formylmethionine-puromycin formation. However, rescue does exert an effect at the level of termination. In addition, the thermolability of the mutant can be reversed by dissociating 70S ribosomes into 30S and 50S subunits. Based on these and other observations, we propose tht rescue mediates a novel function in the association/dissociation of ribosomal subunits which is essential to the accuracy and efficiency of translation.

Autotransplantation of splenic tissue after splenectomy in rats offers partial protection against intravenous pneumococcal challenge

Thirty-six splenectomized Sprague-Dawley rats with omental implants of splenic tissue were challenged with intravenous pneumococci. The mortality rate in this group was compared to 31 similarly challenged splenectomized and 28 normosplenic rats. The results showed that while rats with implanted splenic tissue had a better survival rate (p = 0.04) than splenectomized rats, their survival was poorer than that of rats with normal spleens (p = 0.02) (Fischer's exact test).

Septic portal vein thrombophlebitis: computed tomography appearance. Case report

An unusual case of superinfected thrombosis of the portal and superior mesenteric veins is presented. Thrombus and gas within the portal system were accurately detected by CT. A necrotic segment of distal small bowel was believed to be responsible for the findings. Prompt recognition of this rare entity and rapid initiation of adequate therapy may aid in improving the outcome of this usually fatal condition.