Limulus amebocyte lysate assay for detection of endotoxin in patients with sepsis syndrome. AMCC Sepsis Project Working Group

Clinical predictions alone are insufficiently accurate to identify patients with specific types of bloodstream infection; laboratory assays might improve such predictions. Therefore, we performed a prospective cohort study of 356 episodes of sepsis syndrome and did Limulus amebocyte lysate (LAL) assays for endotoxin. The main outcome measures were bacteremia and infection due to gram-negative organisms; other types of infection were secondary outcomes. Assays were defined as positive if the result was > or = 0.4 enzyme-linked immunosorbent assay units per milliliter. There were positive assays in 119 (33%) of 356 episodes. Assay positivity correlated with the presence of fungal bloodstream infection (P < .003) but correlated negatively with the presence of gram-negative organisms in the bloodstream (P = .04). A trend toward higher rates of mortality in the LAL assay-positive episodes was no longer present after adjusting for severity. Thus, results of LAL assay did not correlate with the presence of bacteremia due to gram-negative organisms or with mortality after adjusting for severity but did correlate with the presence of fungal bloodstream infection.     

Evidence for an X-linked genetic component in familial typical migraine

Although in cord blood (CB) transplantation graft-versus-host disease (GVHD) is reported to be less severe, GVHD may occur even in patients with HLA-identical sibling donors. This result shows that HLA typing can not entirely predict GVHD. The standard MLR with CB cells was either normal or slightly reduced compared with adult peripheral blood (PB) cells. We used two manipulations to increase the responses of CB cells to allo-antigens. The first was to treat the stimulator cells with cytokines, and the second to amplify weak proliferative responses by adding exogenous cytokines to MLR cultures (modified MLR). The stimulator cells were treated with both interferon-gamma (IFN-gamma) and IL-4. The responder cells were treated with both IL-2 and tumour necrosis factor-alpha (TNF-alpha). It is still to be determined whether or not this cytokine-enhanced MLR could be a possible predictor of GVHD. However, using these cytokines, 90% of CB could recognize allo-antigens, even if the standard MLR was negative.     

A repeatable alignment method and local coordinate description for knee joint testing and kinematic measurement

A method for aligning cadaver knee specimens to a mechanical testing rig and determining local anatomical coordinate systems using landmarks identifiable on plane X-rays is introduced. Three sequential rotational alignments arc used to position the femur and tibia relative to the coordinate system of the testing mechanism. To validate this methodology five independent observers aligned the same knee specimen. The maximum error in the alignment orientations of the tibia and femur was 2.2 from the mean. These small misalignments produced variations of up to 4.7 in tibio-femoral rotations measured during knee flexion. Kinematic measurements of 15 specimens aligned using this procedure indicate that knee alignment is reproducible and physiologically relevant.     

Executive dyscontrol: an important factor affecting the level of care received by older retirees

OBJECTIVES: To examine the relative contributions of Executive Control Function (ECF), general cognition, mood, problem behavior, physical disability, demographic variables, and the number of prescribed medications to the level of care received by older retirees. DESIGN: Multivariate regression and discriminant modeling. SETTING: A single Continuing Care Retirement Community (CCRC) in San Antonio, Texas. PARTICIPANTS: A total of 107 older retirees (mean age = 83.7+/-7.2 years), including 17 community-dwelling, well, older controls and 90 CCRC residents. CCRC subjects represented a convenience sample of consecutive referrals for geropsychiatric assessment. Sixty-one subjects resided at a noninstitutionalized level of care, and 46 were institutionalized. MEASUREMENTS: Tests of ECF (the Executive Interview (EXIT25)), general cognition (the Mini-Mental State Examination (MMSE)), mood (the Geriatric Depression Scale short-form (sGDS)), problem behavior (the Nursing Home Behavior Problem Scale (NHBPS)), physical disability (the Cumulative Illness Rating Scale (CIRS)), age, gender, years of education, and the number of prescribed medications were studied. RESULTS: All variables except gender and education varied significantly across level of care. Four variables made significant independent contributions; EXIT25 score (r2 = .48, P< .001), medication usage (partial r2 = .11, P<.001), sGDS score (partial r2 = .06, P = .001), and problem behavior (partial NHBPS r2 = .04, P<.04). These variables accounted for 69% of the total variance in level of care (R2 = .69; F (df 7,99) = 32.1, P<.001). A discriminant model based on the number of prescribed medications, EXIT25, sGDS, and NHBPS scores classified 83.2% of cases correctly (Wilke's lambda = .50, F(5,101) = 20.1; P<.001). The MMSE enters but fails to contribute significantly, independent of the other variables. Age and CIRS scores fail to enter. CONCLUSIONS: Cognitive (particularly ECF) impairment contributes most to the observed variance in level of care received by older retirees in this CCRC. In contrast, markers of general cognition, depression, and physical illness contributed relatively little additional variance. ECF is not detected well by traditional cognitive measures and must be sought by specific tests. Further study is needed to replicate these findings in other populations.     

Balloon angioplasty versus new device intervention: clinical outcomes. A comparison of the NHLBI PTCA and NACI registries

OBJECTIVES: We sought to compare outcomes of patients treated in the National Heart, Lung, and Blood Institute (NHLBI) Percutaneous Transluminal Coronary Angioplasty (PTCA) and New Approaches to Coronary Intervention (NACI) registries. BACKGROUND: Coronary angioplasty has numerous shortcomings. New devices for performing coronary interventions have been introduced in an effort to improve clinical outcomes. METHODS: Under the sponsorship of the NHLBI, a registry of consecutive patients treated with PTCA during 1985 to 1986 was established. In 1990, the NHLBI funded a second registry, the NACI. The two registries used the same data coordinating center to collect detailed baseline and follow-up information. RESULTS: Patients enrolled in the NACI registry were older, had undergone more previous bypass surgery procedures and had more stenoses located in bypass grafts than patients in the NHLBI PTCA registry. Procedural success was achieved in 72.1% and 82.6% of patients in the PTCA and NACI registries, respectively; however, in-hospital and 1-year mortality rates were 1.0% versus 1.8% and 3.1% versus 5.9% for the PTCA versus NACI registries, respectively. After risk adjustment, there was no difference in 1-year mortality. Rates of target lesion revascularization (TLR) were 21.5% for the PTCA registry and 24.2% for the NACI registry. NACI registry patients had a higher risk for TLR and the composite end point of death, myocardial infarction or revascularization (relative risk 1.28 and 1.23, respectively). However, the NACI registry patients who received stents tended to have a lower adjusted TLR rate. CONCLUSIONS: This comparative study found no overall superiority of these newer devices in terms of patient survival or freedom from TLR after adjustment for baseline risk profiles. Although technologic improvements (especially improved stenting) continue, these observations highlight the importance of careful assessment of clinical results in the broad population of patients in whom interventions are used.     

Induction of acrosome reaction in human spermatozoa accelerates the time of pronucleus formation of hamster oocytes after intracytoplasmic sperm injection

OBJECTIVE: To assess the relationship between the incidence of acrosome reaction (AR) and the timing of pronucleus (PN) formation after intracytoplasmic sperm injection (ICSI). DESIGN: Prospective study. SETTING: Infertility Research Center, Jeil Women's Hospital. MAIN OUTCOME MEASURE(S): Human semen obtained from fertile donors was prepared by one of the following methods: washing only (washed control); Percoll gradient; pentoxifylline; human follicular fluid (FF); pentoxifylline + FF; or platelet-activating factor (PAF) treatment. The AR of each group was assessed by fluorescein isothiocyanate-conjugated Pisum sativum agglutinin or Arachis hypogea agglutinin. Spermatozoa of washed control, pentoxifylline + FF, and PAF treated groups, with significantly higher AR rate than others, were injected into mature hamster oocytes. Spermatozoon-injected oocytes were cultured for 6, 9, 12, or 15 hours. Then they were stained with Toluidine blue for PN formation examination under a light microscope. RESULT(S): Acrosome reaction rates of washed control, Percoll gradient, pentoxifylline, FF, pentoxifylline + FF, and PAF treated groups were 10.5% +/- 2.6%, 10.3% +/- 1.7%, 16.4% +/- 1.8%, 24.8% +/- 5.6%, 28.4% +/- 3.8%, and 33.3% +/- 5.2%, respectively. Pronuclear formation rate in washed control, pentoxifylline + FF, and PAF treated groups were 5.6% (3/54), 19.0% (11/58), and 18.9% (10/53) at 6 hours; 32.7% (18/55), 51.8% (29/56), and 57.4% (31/54) at 9 hours; 36.1% (22/61), 53.6% (30/56), and 50.0% (27/54) at 12 hours; and 47.2% (25/53), 64.8% (35/54), 53.6% (30/56) at 15 hours after ICSI. Pronuclear formation rate was significantly higher in pentoxifylline + FF, and PAF treated groups than that in the washed control group at 6 and 9 hours after ICSI. CONCLUSION(S): Pronuclear formation of oocytes takes place faster on those that were injected with acrosome-reacted spermatozoon than those injected with acrosome-intact spermatozoon. It could be concluded that induction of the AR of spermatozoa accelerates the time of PN formation and early development of the embryo in ICSI.     

Bacillus thuringiensis and its pesticidal crystal proteins

During the past decade the pesticidal bacterium Bacillus thuringiensis has been the subject of intensive research. These efforts have yielded considerable data about the complex relationships between the structure, mechanism of action, and genetics of the organism's pesticidal crystal proteins, and a coherent picture of these relationships is beginning to emerge. Other studies have focused on the ecological role of the B. thuringiensis crystal proteins, their performance in agricultural and other natural settings, and the evolution of resistance mechanisms in target pests. Armed with this knowledge base and with the tools of modern biotechnology, researchers are now reporting promising results in engineering more-useful toxins and formulations, in creating transgenic plants that express pesticidal activity, and in constructing integrated management strategies to insure that these products are utilized with maximum efficiency and benefit.     

The phosphotyrosine phosphatase SHP-2 participates in a multimeric signaling complex and regulates T cell receptor (TCR) coupling to the Ras/mitogen-activated protein kinase (MAPK) pathway in Jurkat T cells

Src homology 2 (SH2) domain-containing phosphotyrosine phosphatases (SHPs) are increasingly being shown to play critical roles in protein tyrosine kinase-mediated signaling pathways. The role of SHP-1 as a negative regulator of T cell receptor (TCR) signaling has been established. To further explore the function of the other member of this family, SHP-2, in TCR-mediated events, a catalytically inactive mutant SHP-2 was expressed under an inducible promoter in Jurkat T cells. Expression of the mutant phosphatase significantly inhibited TCR-induced activation of the extracellular-regulated kinase (ERK)-2 member of the mitogen-activated protein kinase (MAPK) family, but had no effect on TCR-zeta chain tyrosine phosphorylation or TCR-elicited Ca2+ transients. Inactive SHP-2 was targeted to membranes resulting in the selective increase in tyrosine phosphorylation of three membrane-associated candidate SHP-2 substrates of 110 kD, 55-60 kD, and 36 kD, respectively. Analysis of immunoprecipitates containing inactive SHP-2 also indicated that the 110-kD and 36-kD Grb-2-associated proteins were putative substrates for SHP-2. TCR-stimulation of Jurkat T cells expressing wild-type SHP-2 resulted in the formation of a multimeric cytosolic complex composed of SHP-2, Grb-2, phosphatidylinositol (PI) 3'-kinase, and p110. A significant proportion of this complex was shown to be membrane associated, presumably as a result of translocation from the cytosol. Catalytically inactive SHP-2, rather than the wild-type PTPase, was preferentially localized in complex with Grb-2 and the p85 subunit of PI 3'-kinase, suggesting that the dephosphorylating actions of SHP-2 may regulate the association of these signaling molecules to the p110 complex. Our results show that SHP-2 plays a critical role in linking the TCR to the Ras/MAPK pathway in Jurkat T cells, and also provide some insight into the molecular interactions of SHP-2 that form the basis of this signal transduction process.     

Pharmacokinetically guided dosing of carboplatin and etoposide during peritoneal dialysis and haemodialysis

The delineation of T helper cell subsets into T helper type 1 (Th1) and T helper type 2 (Th2) populations based on the production of specific cytokines has been useful in understanding the regulation and progression of immune-based pathologies. In order to test the relevance of this concept to human solid organ transplantation, in situ and system Th1 and Th2 cytokine profiles were characterized in liver allograft recipients. Bile and serum samples obtained posttransplant were analyzed for the cytokines IL-2, IFN-gamma, IL-4, and IL-10. Significant elevations of IL-4 and IL-10 were measured at the site of graft rejection. In contrast, IL-2, IFN-gamma, and IL-4 were markedly elevated in the circulation during rejection. Analyses of sequential bile samples revealed that Th1 and Th2 cytokines showed similar kinetics of production in response to alloantigen. Taken together, these results indicate that acute rejection of human allografts can proceed [correction of procede] in the presence of minimal levels of the Th1 cytokines IL-2 and IFN-gamma and high levels of IL-4 and IL-10.