Variability in practice and factors predictive of total crystalloid administration during abdominal surgery: retrospective two-centre analysis.

BACKGROUND: Variation in clinical practice in the perioperative environment and intensive care unit is a major challenge facing modern medicine. The objective of the present study was to analyse intraoperative crystalloid administration practices at two academic medical centres in the USA. METHODS: We extracted clinical data from patients undergoing intra-abdominal procedures performed at UC Irvine (UCI) and Vanderbilt University (VU) Medical Centres. Limiting data to uncomplicated elective surgery with minimal blood loss, we quantified variability in fluid administration within individual providers, between providers, and between types of procedures using a corrected coefficient of variation (cCOV). Regression was performed using a general linear model to determine factors most predictive of fluid administration. RESULTS: For provider analysis and model building, 1327 UCI and 4585 VU patients were used. The average corrected crystalloid infusion rate across all providers at both institutions was 7.1 (sd 4.9) ml kg(-1) h(-1), an overall cCOV of 70%. Individual providers ranged from 2.3 (sd 3.7) to 14 (sd 10) ml kg(-1) h(-1). The final regression model strongly favoured personnel as predictors over other patient predictors. CONCLUSIONS: Wide variability in crystalloid administration was observed both within and between individual anaesthesia providers, which might contribute to variability in surgical outcomes.

Goal-Directed fluid therapy with closed-loop assistance during moderate risk surgery using noninvasive cardiac output monitoring: A pilot study.

BACKGROUND: Goal directed fluid therapy (GDFT) has been shown to improve outcomes in moderate to high-risk surgery. However, most of the present GDFT protocols based on cardiac output optimization use invasive devices and the protocols may require significant practitioner attention and intervention to apply them accurately. The aim of this prospective pilot study was to evaluate the clinical feasibility of GDFT using a closed-loop fluid administration system with a non-invasive cardiac output monitoring device (Nexfin™, BMEYE, Amsterdam, Netherlands). METHODS: Patients scheduled for elective moderate risk surgery under general anaesthesia were enrolled. The primary anaesthesia team managing the case selected GDFT targets using the controller interface and all patients received a baseline 3 ml kg(-1) h(-1) crystalloid infusion. Colloid solutions were delivered by the closed-loop system for intravascular volume expansion using data from the Nexfin™ monitor. Compliance with GDFT management was defined as acceptable when a patient spent more than 85% of the surgery time in a preload independent state (defined as pulse pressure variation <13%) or when average cardiac index during surgery was >2.5 litre min(-1) m(-2). RESULTS: A total of 13 patients were included in the study group. All patients met the established criteria for delivery of GDFT for greater than 85% of case time. The median length of stay in the hospital was 5 [3-6] days. CONCLUSION: In this pilot study, GDFT management using the closed-loop fluid administration system with a non-invasive CO monitoring device was feasible and maintained a high rate of protocol compliance. CLINICAL TRIAL REGISTRATION: NCT02020863.

The paternal inheritance of the centrosome, the cell's microtubule-organizing center, in humans, and the implications for infertility.

Successful fertilization in humans, achieved when parental chromosomes intermix at first mitosis, requires centrosome restoration and microtubule-mediated motility. Imaging of inseminated human oocytes reveals that the sperm introduces the centrosome. The centrosome then nucleates the new microtubule assembly to form the sperm aster--a step essential for successful fertilization. Oocytes from some infertile patients failed to complete fertilization because of defects in uniting the sperm and egg nuclei, indicating that failure to properly effect the cytoplasmic motions uniting the nuclei results in human infertility. These discoveries have important implications for infertility diagnosis and managing reproduction.

Mitochondria and nuclei move by different mechanisms in Aspergillus nidulans.

We have examined the effects of the antimicrotubule agent benomyl and several mutations on nuclear and mitochondrial movement in germlings of the filamentous fungus Aspergillus nidulans. While, as previously reported, benomyl inhibited nuclear division and movement, it did not inhibit mitochondrial movement. To test the effects of benomyl more rigorously, we germinated two benomyl super-sensitive, beta-tubulin mutants at a benomyl concentration 50-100 times greater than that required to inhibit colony formation completely. Again nuclear division and movement were inhibited, but mitochondrial movement was not. We also examined conditionally lethal beta-tubulin mutations that disrupt microtubule function under restrictive conditions. Nuclear division and movement were inhibited but, again, mitochondrial movement was not. Finally we examined the effects of five heat-sensitive mutations that inhibit nuclear movement but not nuclear division at restrictive temperatures. These mutations strongly inhibited nuclear movement at a restrictive temperature but did not inhibit mitochondrial movement. These data demonstrate that the mechanisms of nuclear and mitochondrial movement in Aspergillus nidulans are not identical and suggest that mitochondrial movement does not require functional microtubules.

Waterfall-generated Earth vibrations.

Waterfalls generate periodic earth vibrations whose frequencies are inversely proportional to the height of the waterfall. Action of turbulent eddies is a probable explanation.

18.6-year Earth tide regulates geyser activity.

Over 40 years of records from Yellowstone National Park, Wyoming, show that the 18.6-year tidal component strongly regulates the frequencies of eruption of Grand and Steamboat geysers. The frequency of Grand Geyser increases with increasing tidal force and that of Steamboat Geyser decreases, which suggests that tidal dilatation is one factor affecting heat flow to a geyser.

Metal-ligand pair anisotropy in a series of mononuclear Er-COT complexes.

Synthetic control of the crystal field has elevated lanthanides to the forefront of single-molecule magnet (SMM) research, yet the resultant strong, predictable single-ion anisotropy has thus far not translated into equally impressive molecule-based magnets of higher dimensionality. This roadblock arises from the dual demands made of the crystal field: generate anisotropy and facilitate magnetic coupling. Here we demonstrate that particular metal-ligand pairs can dominate the single-ion electronic structure so fully that the remaining coordination sphere plays a minimal role in the magnitude and orientation of the magnetic anisotropy. This Metal-Ligand Pair Anisotropy (MLPA) effectively separates the crystal field into discrete components dedicated to anisotropy and magnetic coupling. To demonstrate an MLPA building unit, we synthesized four new mononuclear complexes that challenge the electronic structure of the iconic lanthanocene ([Ln(COT)2]+; COT2- = cyclooctatetraene dianion) complex which is known to generate strong anisotropy with Ln = Er3+. Variation in symmetry and coordination strength for Er(COT)I(THF)2 (THF = tetrahydrofuran) (1), Er(COT)I(Py)2 (Py = pyridine) (2), Er(COT)I(MeCN)2 (MeCN = acetonitrile) (3), and Er(COT)(Tp*) (Tp* = tris(3,5-dimethyl-1-pyrazolyl)borate) (4) shows that the Er-COT unit stabilizes anisotropy despite deliberate de-optimization. All four half-sandwich complexes display SMM behavior with effective energy barriers of U eff = 95.6(9), 102.9(3.1), 107.1(1.3), and 133.6(2.2) cm-1 for 1-4 by a multi-relaxation-process fitting. More importantly, the basic state splittings remain intact and the anisotropy axes are within several degrees of normal to the COT2- ring according to complete active space self-consistent field (CASSCF) calculations. Further investigation of the MLPA conceptual framework is warranted as it can provide building units with well-defined magnetic orientation and strength. We envision that the through-barrier processes observed herein, such as quantum tunneling, can be mitigated by formation of larger clusters and molecule-based materials.

Effects of corticosteroids on human monocyte function.

This report examined the effect of corticosteroids in vitro on human peripheral blood monocytes, essential cells in both immune and nonimmune cellular defense mechanisms. Monocyte chemotaxis in response to sera, Escherichia coli filtrate, and lymphokine chemotactic factor was markedly reduced (P < 0.01) by hydrocortisone succinate (HCS) at 16 mug/ml. Methylprednisolone succinate and unesterified hydrocortisone produced similar impairment of monocyte chemotaxis while two drugs which unmodified do not enter cells, hydrocortisone phosphate (HCP) and cortisone acetate, had no effect on chemotaxis. HCS also significantly impaired monocyte random migration at 16 mug/ml. Monocyte bactericidal activity was reduced by HCS at 16 mug/ml (P < 0.01)) but was not affected by HCP even at 120 mug/ml. In comparison, HCS did not alter granulocyte chemotaxis even at 500 mug/ml, and bactericidal activity was reduced at 16 mug/ml (P < 0.01). Monocyte phagocytosis of cryptococci was reduced only 20% (P < 0.05) at 120 mug/ml. HCS at 120 mug/ml did not alter monocyte base-line or postphagocytic hexosemonophosphate shunt activity, viability by trypan blue exclusion, adherence to tissue culture flasks, or surface binding of IgG globulin. These corticosteroid-induced defects in monocyte function may contribute to reduced cellular defense during corticosteroid therapy.

Cell-cell interaction in erythropoiesis. Role of human monocytes.

Erythroid burst forming units (BFU-E) are proliferative cells present in peripheral blood and bone marrow which may be precursors of the erythroid colony forming cell found in the bone marrow. To examine the possible role of monocyte-macrophages in the modulation of erythropoiesis, the effect of monocytes on peripheral blood BFU-E proliferation in response to erythropoietin was investigated in the plasma clot culture system. Peripheral blood mononuclear cells from normal human donors were separated into four fractions. Fraction-I cells were obtained from the interface of Ficoll-Hypaque gradients (20-30% monocytes; 60-80% lymphocytes); fraction-II cells were fraction-I cells that were nonadherent to plastic (2-10% monocytes; 90-98% lymphocytes); fraction-III cells were obtained by incubation of fraction-II cells with carbonyl iron followed by Ficoll-Hypaque centrifugation (>99% lymphocytes); and fraction-IV cells represented the adherent population of fraction-II cells released from the plastic by lidocaine (>95% monocytes). When cells from these fractions were cultured in the presence of erythropoietin, the number of BFU-E-derived colonies was inversely proportional to the number of monocytes present (r = -0.96, P < 0.001). The suppressive effect of monocytes on BFU-E proliferation was confirmed by admixing autologous purified monocytes (fraction-IV cells) with fraction-III cells. Monocyte concentrations of >/=20% completely suppressed BFU-E activity. Reduction in the number of plated BFU-E by monocyte dilution could not account for these findings: a 15% reduction in the number of fraction-III cells plated resulted in only a 15% reduction in colony formation. These results indicate that monocyte-macrophages may play a significant role in the regulation of erythropoiesis and be involved in the pathogenesis of the hypoproliferative anemias associated with infection and certain neoplasia in which increased monocyte activity and monopoiesis also occur.

Ferromagnetic coupling in a chloride-bridged erbium single-molecule magnet.

We present the first ferromagnetically-coupled Er3+ complex with linked, high-anisotropy Er-COT (COT2- = cyclooctatetraene dianion) subunits. The dinuclear complex, [Er(µ2-Cl)(COT)(THF)]2, demonstrates single-molecule magnetism with a single, zero-field magnetization relaxation barrier of Ueff = 113 cm-1. This system offers evidence that anisotropy can be preserved in the presence of ferromagnetic linking of the Er-COT subunits, providing a rational means to build strong molecular magnets of tunable dimensionality.

Induction of lymphokine-activated killer cells in strain 2 guinea pigs with human interleukin-2.

Culture of spleen cells from strain 2 guinea pigs with Jurkat interleukin-2 (IL-2) resulted in the induction of lymphokine-activated killer (LAK) cells. Maximum LAK activity was induced using 5000 pmol of IL-2. Incubation of spleen cells with IL-2 for as little as 8 h resulted in detectable LAK activity. LAK cell activity was transient and could be stimulated by adding back IL-2. LAK cell activity was enriched in a 1.085 single-step percoll gradient. Admixture of guinea pig LAK cells with the line 10 hepatoma prior to intradermal injection resulted in inhibition of tumor growth. Systemic passive transfer of LAK cells together with concurrent IL-2 resulted in a significant inhibition of metastatic tumor growth.

Phase I/II trial of human recombinant beta-interferon serine in patients with renal cell carcinoma.

Beta-interferon serine (IFN-beta ser) is a genetically altered recombinant IFN with a specific activity of 2 X 10(8) IU/mg protein. We undertook a Phase I trial of this agent in 18 patients with metastatic renal cell carcinoma. IFN-beta ser was given by a 4-h intravenous infusion twice weekly (Monday and Thursday). Three patients were placed on escalating dose levels. Doses were also escalated in each patient if no unacceptable toxicity was detected on the previous treatment. The maximum initial tolerated dose was less than or equal to 150 million units/m2. However, development of patient tolerance allowed escalation beyond this dose and chronic therapy at this or higher doses in most patients. Toxicity was largely limited to the symptom complex of fever, malaise, mild hypotension, and anorexia. One patient developed reversible proteinuria (10 g/24 h) with no change in serum creatinine. Limited or no renal, hepatic, or hematological toxicity was observed. Six of 16 patients developed anti-IFN antibody levels. Fifteen patients received twice weekly treatments at near their maximum tolerated dose for greater than or equal to 4 weeks and were evaluable for response. Two patients developed a partial and one patient a minor response. We conclude that IFN-beta ser is a well tolerated IFN with minimal renal, hepatic, and bone marrow toxicity. It has apparent activity in metastatic renal cell carcinoma.

Evaluation of the immunological and toxicological properties of MVE-2 in phase I trials.

Pyran copolymer enhances resistance to infections and transplantable tumors in mice. It induces interferon, activates macrophages, increases antibody-dependent cellular cytotoxicity (ADCC), functions as an adjuvant, and has direct antitumor effects. MVE-2, a low-molecular-weight (15,000) component of pyran copolymer, exhibited less toxicity and essentially the same positive biological effects as pyran copolymer. MVE-2 was, therefore, chosen for clinical trials. This study was designed to determine the toxicity and immunological effects of MVE-2 in humans. Fourteen patients who received biweekly MVE-2 had lymphocyte and monocyte ADCC, natural killer activity, and monocyte to macrophage maturation measured 2, 3, 7, 10, and 13 days after each of the first three doses of MVE-2. Lymphocyte antibody-dependent cellular cytotoxicity and monocyte maturation increased significantly following MVE-2 administration and the effect persisted at least 4 weeks. Although numbers were small, the enhanced ADCC seemed related to both single dose and cumulative dose of MVE-2. Five of six patients receiving more than 2 g of MVE-2 had improvement in lymphocyte ADCC. Increases in lymphocyte and monocyte natural killer activity approached, but did not attain statistical significance. Proteinuria was the dose-limiting toxicity, but was reversible. MVE-2 induced a modest, but real enhancement of lymphocyte and monocyte function at doses that were well tolerated.

Phase I/II trial of interferon-beta-serine in patients with renal cell carcinoma: immunological and biological effects.

Interferon-beta-serine (IFN-beta ser) is a recombinant genetically altered interferon with extensive in vitro antiproliferative, antiviral, and immunological effects. We undertook a Phase I/II trial of this agent in patients with untreated metastatic renal cell carcinoma with good performance status. IFN-beta ser was given twice weekly (Monday/Thursday) by a 4-h i.v. infusion. Three patients were entered at increasing drug levels until the maximum tolerated dose was determined. Moreover, if individual patients tolerated the initial IFN treatment, the dose was escalated one level at the next treatment. Preliminary studies with normal donor cells demonstrated that IFN-beta ser in vitro enhanced activity in a mononuclear-MBL-2 growth inhibition, NK-cell, and monocyte antibody-dependent cellular cytotoxicity assay. Therefore, prior to therapy these in vitro tests were performed utilizing each patient's mononuclear cells in an attempt to predict tumor response with in vitro immunological response to IFN. In general, there was no difference in IFN responsiveness in vitro between patients who developed tumor response (3) and those who did not (12). After initiation of treatment blood was taken from patients at frequent intervals for assessment of biological response. The following parameters were not altered at any dose or time interval: T-cell number, T-H/S ratio, % Leu 11a-positive cells, percentage or intensity of staining with anti-HLA-DR, and concanavalin A driven T-cell proliferation. Monocyte antibody-dependent cellular cytotoxicity was significantly depressed 4 h after doses of 30-150 million units/m2 but returned to base line at 24 h. Activity in three assays was significantly increased in patients receiving therapy: MBL-2/growth inhibition assay, NK-cell, and 2',5' oligonucleotide synthetase activity. In general changes in these assays were observed at low levels of IFN-beta ser, increased at 4-48 h, then returned toward base line. We conclude that IFN-beta ser is an active biological agent in vitro and significantly modulated the biological responses in patients with renal cell carcinoma.

Lysozyme enhancement of tumor cell immunoprotection in a murine fibrosarcoma.

We examined the ability of human lysozyme (HLZM) to enhance the immunogenicity of a methylcholanthrene-induced murine fibrosarcoma of C57BL/10 mice. Following s.c. injection of 10(4) live tumor cells, 100% of mice developed palpable tumors within 16 +/- 3 (S.D.) days. Prechallenge immunization with 10(6) irradiated tumor cells with or without complete Freund's adjuvant resulted in protection from tumor development in 14 and 22% of mice, respectively. Incubation of tumor cells with HLZM prior to immunization approximately doubled the degree of protection, with 42 to 44% of mice remaining free of tumor. This enhanced protection was dependent on the enzymatic activity of HLZM. These data suggest that HLZM enhances tumor cell immunogenicity in this model.

Characterization and modulation of human lymphokine (interleukin 2) activated killer cell induction.

Culture of human peripheral blood mononuclear cells with purified interleukin 2 (IL-2) results in the induction of a cytotoxic population of cells capable of lysing autologous tumor cells and natural killer (NK) cell resistant tumor cell lines. The current study was undertaken to characterize biological agents which might modulate the induction of lymphokine (IL-2) activated killer (LAK) cells and to optimize culture conditions for LAK cell induction. Preliminary studies were undertaken to characterize optimal time and IL-2 concentration for induction of LAK cell activity. Subsequently, we demonstrated that: (a) LAK cell induction is inhibited at high (2.5 X 10(6)/ml) cell concentrations and this phenomenon is due to the presence of monocytes; (b) depletion of monocytes allows LAK cell induction at 5-10-fold higher cell concentrations without altering the extent or range of LAK-cell activity; (c) interleukin 1 enhances and alpha- and beta-interferons inhibit IL-2 induced proliferation, without altering LAK cell induction; and (d) gamma-interferon alters neither IL-2 induction of proliferation nor LAK cell activity.

Immunological effects of flavone acetic acid.

Flavone acetic acid (FAA) enhances natural killer and lymphokine-activated killer (LAK) cell activity in mice. We examined the immunological effects of FAA on human blood cells both in vivo and in vitro. Peripheral blood natural killer and LAK activity and lymphocyte subsets were evaluated in cancer patients after receiving 3-h infusion of FAA at either 8.5 or 10 g/m2 with alkalinization. Natural killer cell activity and the number of Leu-19 (CD56) positive cells decreased at 24 h after infusion; significant changes in LAK activity and the number of Leu-1 (CD5), Leu-3 (CD4), Leu-2 (CD8) cells were not observed. Peripheral blood mononuclear cells and peripheral blood lymphocytes collected from healthy volunteers were exposed in vitro to FAA, interleukin 2, and FAA plus interleukin 2. FAA, alone or in combination, failed to enhance LAK activity at any time point or concentration from peripheral blood mononuclear cells and peripheral blood lymphocytes. Concentrations of greater than or equal to 100 micrograms/ml antagonized the generation of LAK activity from interleukin 2 treated peripheral blood lymphocytes. These data suggest that FAA may not be useful in enhancing immunological responses in humans.

Lymphocyte supernatant-induced human monocyte tumoricidal activity: dependence on the presence of gamma-interferon.

Recently, gamma-interferon (IFN-gamma) has been shown to be have the capacity to activate macrophages in several murine and human systems. The studies reported here were undertaken to determine the identity of the lymphokine responsible for activation of human monocytes to a tumoricidal state. Macrophage-activating factor (MAF) activity was assessed using a 24-h 51Cr release assay with human monocytes as effector cells and K-562 targets. Stimulated lymphocyte supernatants were produced by stimulation of peripheral blood mononuclear cells with concanavalin A in serum-free media. Interferon was detected in an antiviral assay. Four lines of evidence lead to the conclusion that MAF and IFN-gamma are identical in this system: (a) fractionation of stimulated lymphocyte supernatants by adsorption chromatography, followed by anion or cation exchange chromatography (Mono-S, Mono-Q columns), resulted in nearly identical elution profiles of MAF and IFN activities. All of the individual fractions containing MAF activity were found to contain IFN in amounts corresponding to MAF activity. (b) Monoclonal antibody specific for IFN-gamma neutralized the ability of stimulated lymphocyte supernatants to induce human monocyte tumoricidal activity. This antibody also neutralized the MAF activity of purified IFN-gamma but not alpha-interferon. (c) The biological MAF activity of activated lymphocyte supernatants and IFN-gamma were similar. Dilution versus MAF activity for IFN-gamma and stimulated lymphocyte supernatants exhibited identical slopes. Lymphocyte supernatants and IFN-gamma demonstrated similar MAF activity on three effector cells: monocytes, in vitro-differentiated macrophages, and dexamethasone-differentiated macrophages. (d) Analysis of supernatants produced by five antigen-stimulated human T-cell clones demonstrated coordinate production of MAF and IFN. These results provide compelling evidence for support of the concept that IFN-gamma is the major human lymphokine capable of inducing monocyte-macrophage tumoricidal activity.

Endocytosis in adenosine triphosphate-depleted erythrocytes.

The extent of membrane invagination or endocytosis in intact erythrocytes was quantified by measuring the loss of acetylcholinesterase activity. Primaquine-induced endocytosis was completely inhibited in ATP-depleted cells. However, chlorpromazine and vinblastine were capable of inducing membrane invagination in depleted cells. With both drugs, the loss of enzyme activity was less than that measured in fresh cells. We conclude that drug-induced endocytosis is not necessarily an energy-dependent process.

Phase II trial of interferon-beta-serine in metastatic renal cell carcinoma.

Interferon-beta-serine (IFN-beta-ser) is a muteine, recombinant IFN that is tolerated at a dose fivefold to 10-fold higher than IFN-alfa and interacts with the same cell membrane receptor as IFN-alfa. We hypothesized that at high doses IFN-beta-ser might induce a higher response rate than IFN-alfa in metastatic renal cell carcinoma. We undertook a phase II trial of IFN-beta-ser in patients with metastatic renal cell carcinoma. Patients were treated three times each week by a 2-hour intravenous infusion. Doses were escalated weekly (.25 to 5.5 mg, 1 mg = 180,000,000 U) until the maximum-tolerated treatment dose (MTTD) was determined. The MTTD is defined as one dose level less than that which caused grade 3 toxicity and was subsequently administered three times weekly for at least 4 weeks. Twenty-nine patients were entered, and 25 were assessable for response and toxicity. The performance status was 0-1 in all patients and only one patient received previous chemotherapy. The MTTD dose was 2.5 mg (range, 0.5 to 5.5 mg per treatment), although in 10 patients, doses were later deescalated because of cumulative toxicity. Initial dose-limiting toxicity and cumulative toxicity were fatigue, malaise, and fever in most patients. Hepatic transaminitis, neutropenia, and elevation of serum creatinine were also observed but were not dose-limiting. There was one complete response (CR) and four partial responses (PRs). All responses but one occurred in pulmonary metastases. The median time to response was 26 days (range, 17 to 102 days). These data demonstrate that IFN-beta-ser given in high doses exhibits significant antitumor activity in renal cell carcinoma; however, the objective response rate is 20%. This is no higher than previous IFN studies; therefore, we reject the hypothesis than IFN-beta-ser at high doses may induce a greater response rate than IFN-alfa. However, we did observe more responses than were seen in a similar trial undertaken with lower dose IFN-beta serine in renal cell carcinoma.