Heparin and enoxaparin enhance endotoxin-induced tumor necrosis factor-alpha production in human monocytes

OBJECTIVE: To determine whether heparin or the low-molecular-weight heparin enoxaparin alter lipopolysaccharide (LPS)-induced monocyte activation. SUMMARY BACKGROUND DATA: Heparin is widely used in clinical practice to inhibit the coagulation cascade. However, heparin also is a naturally occurring glucosaminoglycan and a pleiotropic immunomodulator that binds to a variety of proteins. LPS is a component of gram-negative bacteria and is thought to be responsible for many of the deleterious effects seen in sepsis. The binding of LPS to CD14 induces a signaling cascade that results in the release of many inflammatory mediators, including tumor necrosis factor-alpha (TNF-alpha). METHODS: Monocytes from healthy volunteers were isolated and cultured in the presence of saline, LPS (10 ng/ml), heparin (0.1 to 1000 microg/ml), or enoxaparin (0.1 to 1000 microg/ml). In blocking experiments, cells were pretreated for 60 minutes with the monoclonal anti-CD14 antibody MY4 (10 microg/ml) or with isotype-matched control IgG2 (10 microg/ml). TNF-alpha values were measured with enzyme-linked immunosorbent assay. Significance was assessed with analysis of variance. RESULTS: Heparin (10 to 1000 microg/ml) and enoxaparin (1000 microg/ml) significantly enhanced LPS-induced TNF-alpha release. Heparin (1000 microg/ml) or enoxaparin (1000 microg/ml) did not produce TNF-alpha in the absence of LPS. Blockade of CD14 abrogated both LPS-induced TNF-alpha release and the effect of heparin or enoxaparin to enhance LPS-induced TNF-alpha release. CONCLUSIONS: The effect of heparin to enhance LPS-induced TNF-alpha release is a biologic phenomenon that reveals a novel and potentially important host defense mechanism during endotoxemia and sepsis. Binding of LPS to CD14 is necessary to induce this phenomenon, suggesting that both heparin and enoxaparin induce signaling mechanisms that are downstream from the initial binding of LPS on CD14.     

Controlled trial of azathioprine in treatment of steroid-responsive nephrotic syndrome of childhood

A controlled trial of azathioprine treatment of steroid-responsive frequent-relapsing nephrotic syndrome of childhood failed to show a therapeutic effect on the stability of remission after withdrawal of corticosteroid treatment.     

Response of preterm infants to diphtheria-tetanus-pertussis vaccine

The American Academy of Pediatrics recommendation that immunization of preterm infants with diphtheria-tetanus-pertussis (DTP) vaccine should begin at 2 months after birth, regardless of gestational age, is based on limited data. A prospective study was conducted to determine the immunogenicity and safety of DTP vaccine in preterm infants. One hundred ten preterm and 146 full term infants received doses of DTP at 2, 4 and 6 months after birth. Adjusted analysis of the antibody responses indicated that after three doses mean titers among preterm infants to each vaccine component were comparable to those of full term infants. Adjusted analysis of the incidence of adverse events indicated that the risk of adverse events in preterm infants was not significantly higher than that in full term infants. DTP vaccine is immunogenic and safe in preterm infants when the series is initiated at 2 months after birth, and this study supports the current recommendation of the American Academy of Pediatrics.     

Bacterial inoculum and the activity of antimicrobial agents

Experimental and clinical infections have concentrations of bacteria that are greater than the concentrations used in the laboratory for the determination of in vitro activity. When realistic concentrations are used, the antibiotic activity is reduced. The optimum selection of antibiotics may require a re-examination of the laboratory procedures for the determination of sensitivity data.     

An unusual pattern of mutation in the duplicated portion of PKD1 is revealed by use of a novel strategy for mutation detection

The gene for the most common and severe form of autosomal dominant polycystic kidney disease, PKD1, encodes a 14 kb mRNA that is predicted to result in an integral membrane protein of 4302 amino acids. The major challenge faced by researchers attempting to complete mutation analysis of the PKD1 gene has been the presence of several homologous loci also located on chromosome 16. Because the sequence of PKD1 and its homologs is nearly identical in the 5' region of the gene, most traditional approaches to mutation analysis cannot distinguish sequence variants occurring uniquely in PKD1. Therefore, only a small number of mutations have been identified to date and these have all been found in the 3', unique portion of the gene. In order to begin analysis of the duplicated region of PKD1, we have devised a novel strategy that depends on long-range PCR and a single gene-specific primer from the unique region of the gene to amplify a PKD1-specific template that spans exons 23-34. This 10 kb template, amplified from genomic DNA, can be employed for mutation analysis using a wide variety of sequence- based approaches. We have used our long-range PCR strategy to begin screening for sequence variants with heteroduplex analysis, and several affected individuals were discovered to have clusters of base pair substitutions in exons 23 and 25. In two patients, these changes, identified in exon 23, would be predicted to result in multiple amino acid substitutions in a short stretch of the protein. This clustering of base pair substitutions is unusual and suggests that mutation may result from unique structural features of the PKD1 gene.      

Evaluation of the Sensititre system for identification of Enterobacteriaceae.

The Sensititre identification system (Seward Laboratory/GIBCO Laboratories) consists of a microplate containing a pattern of 24 biochemicals repeated four times together with an automatic inoculation device and a microcomputer-assisted data interpretation component. A total of 1,415 isolates of Enterobacteriaceae plus 6 isolates of other glucose-fermenting gram-negative bacilli were tested in three hospital laboratories in parallel with API 20E (Analytab Products). Discrepancies were resolved by conventional biochemical testing. Sensititre yielded correct identifications at the species level with 94.6% of the isolates and at the genus level with an additional 1.9%. API 20E yielded correct species identification with 91.1% and genus only identification with an additional 6.7% of the isolates. For the routine identification of clinical Enterobacteriaceae isolates, the Sensititre system compares favorably with API 20E and offers clinical laboratories the economy of a microtiter plate system as well as the benefit of a microcomputer capable of other microbiological and data management applications.     

Transcolonic retrograde ureteric catheterization assisted by 3-D computed tomography

A 42-year-old woman had bladder exstrophy at birth, treated by ureterocolic anastomosis of her single kidney. She suffered recurrent hyperammonaemia, leading to comas, but refused an ileal conduit. During her most recent coma, it was decided to divert her urine to test whether this would reduce hyperammonaemia: this was accomplished by transcolonic retrograde catheterization of the ureter. This was only possible after computed tomography ureterography to show the ureterocolic anastomosis.     

Lumbar arterial injury: radiologic diagnosis and management

Injury of the lumbar arteries is a cause of potentially life-threatening retroperitoneal hemorrhage. Twelve patients who sustained massive hemorrhage of the lumbar arteries associated with lumbar spinal fractures and/or pelvic fractures are described. Computed tomography (CT) was helpful by revealing a distinct separation of the lumbar hemorrhage from the hematomas associated with pelvic fracture. On arteriograms, stasis within lumbar extravasation was manifested as globular or streaky accumulations of contrast medium, pseudoaneurysms or diffuse "staining," or opacification of a fracture site. Multiple lumbar bleeding sites were seen frequently. Embolization with pledgets of absorbable gelatin sterile sponge controlled bleeding in ten patients. Abdominal aortography should be an essential part of the arteriographic evaluation of retroperitoneal hematomas associated with pelvic fractures, especially when there are lumbar fractures. Selective lumbar arteriography should be performed for confirmation when there is suspicion of lumbar artery injury on the basis of aortographic findings. Embolization with pledgets of surgical gelatin is effective in controlling hemorrhage from these injuries.     

Right heart dysfunction, pulmonary embolism, and paradoxical embolization during liver transplantation. A transesophageal two-dimensional echocardiographic study

In 16 adult patients, we performed continuous intraoperative two-dimensional transesophageal echocardiography (2DTEE) to help elucidate the mechanism of myocardial dysfunction that accompanies liver transplantation. In 4 of the 16 patients "paradoxical" motion of the interventricular septum consistent with right ventricular failure was seen. An additional three of the 16 patients showed right atrial enlargement and right-to-left deviation of the interatrial septum. Two patients showed evidence of paradoxical embolization (one of whom had right ventricular and right atrial enlargement), and a third patient (who had right atrial enlargement) embolized a large right atrial thrombus into the pulmonary circulation. Two-dimensional transesophageal echocardiography demonstrated that isolated right ventricular failure might account for some of the hemodynamic instability seen during liver transplantation. Venous, pulmonary, and paradoxical embolization of air and thrombi documented by transesophageal echocardiography likely contribute to right heart failure.