[Evaluation of the success of medical abortion by a plasma hCG control threshold]

OBJECTIVES

In France, monitoring of the success of medical abortion is recommended 2 to 3 weeks after the procedure. However, there is no clear consensus on the modalities of this monitoring. The main objective of this study is to identify a threshold of serum hCG (human chorionic gonadotropin) control for medical abortions ≤7 weeks of gestation below which success can be confirmed without recourse to pelvic ultrasound.

METHODS

This is a retrospective multicenter study conducted over a 14-month period. The serum hCG level, measured between the 15th and 25th day following the abortion, was compared with the results of the pelvic ultrasound performed at the follow-up visit. Ultrasound failure was defined as retention or persistent pregnancy.

RESULTS

Among the 624 women included, the failure rate was 22.3%, including 86.3% of retentions, 8.6% of pregnancies stopped and 5% of pregnancies progressed. Using a ROC curve, the threshold value of hCG found to exclude failure at 95% was 253 IU/l (AUC=0.9202, sensitivity=84.17%, specificity=85.95% and positive predictive value [PPV]=63%).

CONCLUSIONS

A serum hCG level ≤253 IU/l is sufficient to affirm the efficacy of medical abortion. However, since PPV is only 63% for this threshold, ultrasound should be reserved for women with high hCG levels.

Abstract 2842: Neutrophil migration towards tumor-conditioned media correlates with the malignant potential of breast tumor cells

During tumor development, neutrophils and other immune cells infiltrate the tumor niche. Neutrophils have been shown to have primarily pro-tumorigenic effects, and high levels of circulating neutrophils are indicative of a poor prognosis. Tumor-associated neutrophils (TANs) migrate to tumors by sensing chemical gradients produced by tumor cells; however, the mechanisms by which tumors and TANs interact and impact each other remain to be determined. It has been shown that malignant breast tumors, such as triple-negative breast tumors, harbor more TANs compared to less aggressive breast tumors. We hypothesize that neutrophil recruitment to the tumor niche depends on tumor-secreted, chemotactic factors that are primarily produced by malignant breast tumors. To test this, we used a panel of breast cancer cells grown in monolayers and more physiologically-relevant tumor spheroids, which were formed over the course of four days using the hanging-drop method. We characterized the size and morphology of the spheroids, which were generated from the poorly metastatic BT474 cells, as well as the highly malignant BT549 cells, MDA-MB-231 cells, and M4 cells of the MCF-10A cell series. We then compared the ability of tumor-conditioned media (TCM) isolated from either monolayers or spheroids to stimulate the migration of primary human neutrophils using transwell assays. We found that, compared to TCM isolated from control or poorly metastatic cell lines, the TCM derived from highly malignant cancer cells robustly stimulated the migration of neutrophils. These data indicate that breast cancer cells secrete factors with unique profiles that have varying potentials to recruit neutrophils. We are in the process of identifying specific tumor-secreted factors in the TCM using mass spectrometry. Additionally, we are assessing how the presence of neutrophils affects cancer cell migration and invasion by utilizing a coculture system in which tumor spheroids and primary neutrophils are imaged in real time. We reason that understanding the role of TANs during breast cancer progression will provide insight into novel therapeutic approaches, particularly in the context of highly metastatic forms of the disease.

Citation Format: Lauren Hein, Shuvasree SenGupta, Yang Xu, Carole Parent. Neutrophil migration towards tumor-conditioned media correlates with the malignant potential of breast tumor cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2842.

Human kallikrein-related peptidase 12 stimulates endothelial cell migration by remodeling the fibronectin matrix

Kallikrein-related peptidase 12 (KLK12) is a kallikrein family peptidase involved in angiogenesis - a complex biological process in which the sprouting, migration and stabilization of endothelial cells requires extracellular matrix remodeling. To characterize the molecular mechanisms associated with KLK12's proangiogenic activity, we evaluated its ability to hydrolyze various matrix proteins. Our results show that KLK12 efficiently cleaved the human extracellular matrix proteins fibronectin and tenascin, both of which are involved in the regulation of endothelial cell adhesion and migration. For fibronectin, the major proteolytic product generated by KLK12 was a 29 kDa fragment containing the amino-terminal domain and the first five type I fibronectin-domains, which are essential for regulating fibronectin assembly. We also demonstrated that KLK12-mediated fibronectin proteolysis antagonizes fibronectin polymerization and fibronectin fibril formation by endothelial cells, leading to an increase in cell migration. Furthermore, a polyclonal antibody raised against KLK12's proteolytic cleavage site on fibronectin prevented the KLK12-dependent inhibition of fibronectin polymerization and the KLK12-mediated pro-migratory effect on endothelial cells. Taken as a whole, our results indicate that KLK12's proangiogenic effect is mediated through several molecular mechanisms.

Management of breech and twin labor during registrarship: A two-year prospective, observational study

INTRODUCTION

Breech presentation and twin pregnancy are regarded as stressful situations for medical staff. This stress is often associated with an increased likelihood of intervention during labor - especially when the on-shift obstetrician lacks experience.

MATERIAL AND METHODS

We performed a 2-year prospective, observational study of cesarean section (CSDs) and assisted vaginal (AVDs) deliveries in a tertiary maternity unit for attempted vaginal deliveries of breech presentations and twin pregnancies. The obstetric management decisions taken by a group of four registrars were compared with those taken by a group of 11 experienced obstetricians. Changes over time in practice were also monitored.

RESULTS

Registrars managed 66 and 52 breech presentations and twin pregnancies respectively (30 and 27 in the experienced group). Groups' neonatal outcomes were similar. There were no intergroup differences in proportions of CSDs for either breech presentations (25 [37.5%] vs. 15 [50%] in the registrar and experienced groups, respectively; P=0.26) or twin pregnancies (11 [21.1%] vs. 6 [22.2%], respectively; P=0.91) or in proportion of AVDs for twin pregnancies (41 [78.8%] vs. 21 [77.8%], respectively; P=0.91). Proportions of CSDs for breech presentation and AVDs for twin pregnancies did not change over time in either group. However, proportion of CSDs for twin pregnancies increased over time in the registrar group (P=0.004).

DISCUSSION

Well-trained registrars appeared to have acquired the skills required to safely manage an obstetric ward; this pleads to maintain clinical practice during residency to preserve low CSD and AVD rates.

Chemotaxis: moving forward and holding on to the past

The ability of cells to sense external chemical cues and respond by directionally migrating towards them is a fundamental process called chemotaxis. This phenomenon is essential for many biological responses in the human body, including the invasion of neutrophils to sites of inflammation. Remarkably, many of the molecular mechanisms involved in controlling neutrophils chemotaxis arose millions of years ago in the simple eukaryotic organism Dictyostelium discoideum. Both neutrophils and Dictyostelium use G protein-coupled signaling cascades to mediate chemotactic responses, which are responsible for transducing external cues into highly organized cytoskeletal rearrangements that ultimately lead to directed migration. By using the genetically and biochemically tractable organism Dictyostelium as a model system, it has been possible to decipher many of the signal transduction events that are involved in chemotaxis.

Evaluation of Forecasting Models for Fusarium Head Blight of Wheat Under Growing Conditions of Quebec, Canada

Fusarium head blight (FHB) is a fungal disease of wheat (Triticum aestivum L.) causing frequent economic losses to farmers under growing conditions of Eastern Canada. To assess risks associated with this disease and guide fungicide use decisions, many researchers from numerous countries have developed weather-based forecasting models. This work aims at evaluating which model produces the most accurate predictions of disease infection or deoxynivalenol (DON) content under climatic conditions occurring in Quebec. Spring wheat was grown during two seasons and winter wheat during one season at four experimental sites located in Quebec. Nine selected models for evaluation produced predictions of DON content (Canada and Italy), disease incidence (Argentina and Italy), and probability of epidemics (United States). Data from plots without fungicide (52 samples) were used to test the models listed above. Reliability of the selected forecasting models was evaluated with receiver operating characteristic (ROC) curve analysis. DON content (≥1 ppm) was the best crop damage indicator to differentiate epidemic (cases) and nonepidemic (controls) situations. Two American and the Argentinean forecasting models were more reliable than the others when the thresholds recommended in the literature were adjusted using the results for the ROC curve analyses. Those models are a good starting point for the implementation of an FHB forecasting system adapted to wheat production in Quebec.

Carole Parent: migrating cells relay the message

Parent studies cell motility in Dictyostelium, neutrophils, and cancer cells.

Cell shape dynamics: from waves to migration

We observe and quantify wave-like characteristics of amoeboid migration. Using the amoeba Dictyostelium discoideum, a model system for the study of chemotaxis, we demonstrate that cell shape changes in a wave-like manner. Cells have regions of high boundary curvature that propagate from the leading edge toward the back, usually along alternating sides of the cell. Curvature waves are easily seen in cells that do not adhere to a surface, such as cells that are electrostatically repelled from surfaces or cells that extend over the edge of micro-fabricated cliffs. Without surface contact, curvature waves travel from the leading edge to the back of a cell at -35 µm/min. Non-adherent myosin II null cells do not exhibit these curvature waves. At the leading edge of adherent cells, curvature waves are associated with protrusive activity. Like regions of high curvature, protrusive activity travels along the boundary in a wave-like manner. Upon contact with a surface, the protrusions stop moving relative to the surface, and the boundary shape thus reflects the history of protrusive motion. The wave-like character of protrusions provides a plausible mechanism for the zig-zagging of pseudopods and for the ability of cells both to swim in viscous fluids and to navigate complex three dimensional topography.

Deafening decreases neuronal incorporation in the zebra finch caudomedial nidopallium (NCM)

New neurons formed in the adult brain are incorporated into existing circuits. However, the number of new neurons recruited into a given brain region varies widely depending on the experience of the animal. An emerging general principle is that recruitment and early neuronal survival may be correlated with activity or use of the brain region. Here we show that use-dependent neuronal survival also occurs in the higher order auditory processing region of the songbird caudomedial nidopallium (NCM). We suggest that retention of young neurons may in part be influenced by use of the system without an increased demand for learning or behavioral plasticity.

Acute G-CSF therapy is not protective during lethal E. coli sepsis

We investigated whether decreases in circulating polymorphonuclear neutrophils (PMN) during lethal Escherichia coli (E. coli) sepsis in canines are related to insufficient host granulocyte colony-stimulating factor (G-CSF). Two-year-old purpose-bred beagles had intraperitoneal E. coli-infected or -noninfected fibrin clots surgically placed. By 10 to 12 h following clot, both infected survivors and nonsurvivors had marked increases (P = 0.001) in serum G-CSF levels (mean peak G-CSF ng/ml +/- SE, 1,931 +/- 364 and 2,779 +/- 681, respectively) compared with noninfected controls (134 +/- 79), which decreased at 24 to 48 h. Despite increases in G-CSF, infected clot placement caused delayed (P = 0.06) increases in PMN (mean +/- SE change from baseline in cells x 10(3)/mm(3) at 24 and 48 h) in survivors (+3.9 +/- 3.9 and +13.8 +/- 3.6) compared with noninfected controls (+13.1 +/- 2.8 and +9.1 +/- 2.5). Furthermore, infected nonsurvivors had decreases in PMN (-1.4 +/- 1.0 and -1.1 +/- 2.3, P = 0.006 compared with the other groups). We next investigated whether administration of G-CSF immediately after clot placement and continued for 96 h to produce more rapid and prolonged high levels of G-CSF after infection would alter PMN levels. Although G-CSF caused large increases in PMN compared with control protein from 2 to 48 h following clot in noninfected controls, it caused much smaller increases in infected survivors and decreases in infected nonsurvivors (P = 0.03 for the ordered effect of G-CSF comparing the three groups). Thus insufficient host G-CSF is unlikely the cause of decreased circulating PMN in this canine model of sepsis. Other factors associated with sepsis either alone or in combination with G-CSF itself may reduce increases or cause decreases in circulating PMN.

The Relation Between Well-Being, Impostor Feelings, and Gender Role Orientation Among Canadian University Students

A theoretical model of well-being identifies 6 key components that have been examined primarily in older adults (e.g., C. D. Ryff, 1989c, 1991): self-acceptance, positive relations with others, autonomy, environmental mastery, purpose in life, and personal growth (C. D. Ryff, 1995; C. D. Ryff & C. L. M. Keyes, 1995; C. D. Ryff & B. Singer, 1996). The authors examined them in a sample of 379 Canadian university students to determine how well-being was correlated with endorsement of stereotypic gender roles and with the impostor phenomenon. The participants completed Ryff's Scales of Psychological Well-Being (Ryff, personal communication, March 1996), the Clance Impostor Phenomenon Scale (P. R. Clance & M. A. O'Toole, 1988), and the Extended Personal Attributes Questionnaire (J. T. Spence, R. L. Helmreich, & C. K. Holahan, 1979). The results supported the hypotheses that (a) people with higher scores for expressive traits score higher for well-being stemming from positive relations with others, (b) people with higher scores for instrumental traits score higher for well-being related to feelings of autonomy, (c) people with higher scores for impostor feelings (and lower scores for ability confidence) score lower for self-acceptance and (d) for environmental mastery.

A temperature-sensitive adenylyl cyclase mutant of Dictyostelium

Dictyostelium development starts with the chemotactic aggregation of up to 10(6) amoebae in response to propagating cAMP waves. cAMP is produced by the aggregation stage adenylyl cyclase (ACA) and cells lacking ACA (aca null) cannot aggregate. Temperature-sensitive mutants of ACA were selected from a population of aca null cells transformed with a library of ACA genes, a major segment of which had been amplified by error-prone PCR. One mutant (tsaca2) that can complement the aggregation null phenotype of aca null cells at 22 degrees C but not at 28 degrees C was characterized in detail. The basal catalytic activity of the enzyme in this mutant was rapidly and reversibly inactivated at 28 degrees C. Using this mutant strain we show that cell movement in aggregates and mounds is organized by propagating waves of cAMP. Synergy experiments between wild-type and tsaca2 cells, shifted to the restrictive temperature at various stages of development, showed that ACA plays an important role in the control of cell sorting and tip formation.

ICAM-1 and CD11b inhibition worsen outcome in rats with E. coli pneumonia

We investigated whether inhibiting an endothelial adhesion molecule [intracellular adhesion molecule 1 (ICAM-1)] would alter outcome and lung injury in a similar fashion to inhibition of a leukocyte adhesion molecule (integrin CD11b) in a rat model of gram-negative pneumonia. Inhibition of ICAM-1 with monoclonal antibody (MAb) 1A29 (1 mg/kg sc or 0.2 or 2 mg/kg iv, q 12 h x 3) or of CD11b with MAb 1B6 (1 mg/kg sc, q 12 h x 3) were compared against similarly administered placebo proteins in rats challenged with intrabronchial Escherichia coli. After challenge, all animals were treated with antibiotics. ICAM-1 MAb (6 mg/kg, iv, total dose) increased mortality vs. control (P = 0.03). CD11b MAb (3 mg/kg, sc, total dose) did not significantly (P = 0.16) increase mortality rates, but this was not in a range of probability to exclude a harmful effect. All other doses of MAb had no significant effect on survival rates. ICAM-1 and CD11b MAbs had significantly different effects on the time course of lung injury, circulating white cells and lymphocytes, and lung lavage white cells and neutrophils (P = 0.04-0.003). CD11b MAb decreased, whereas ICAM-1 MAb increased these measures compared with control from 6 to 12 h after E. coli. However, from 144 to 168 h after E. coli both MAbs increased these measures compared with control rats but to a greater level with CD11b MAb. Thus both ICAM-1 and CD11b appear to be necessary for survival during E. coli pneumonia. Although these adhesion molecules may participate differently in early lung injury, with CD11b increasing and ICAM-1 decreasing inflammation and injury, both are important for the resolution of later injury. During gram-negative pneumonia the protective roles of ICAM-1 and CD11b may make their therapeutic inhibition difficult.

Neutrophil and endothelial cell interactions in sepsis. The role of adhesion molecules

Although adhesion molecules present on circulating neutrophils and endothelial cells are essential for normal host defense, generalized activation of these molecules has been implicated in the inflammatory tissue injury occurring during sepsis and septic shock. A review of both preclinical and clinical studies suggests, however, that although these molecules mediate tissue injury related to a variety of microbial and host inflammatory mediators, their predominant role during sepsis with infection is a protective one.

G-CSF during Escherichia coli versus Staphylococcus aureus pneumonia in rats has fundamentally different and opposite effects

We investigated if bacteria type alters outcome with prophylactic granulocyte colony stimulating factor (G-CSF) therapy during pneumonia. Rats received G-CSF or placebo daily for 6 d and after the third dose were intrabronchially inoculated with either Escherichia coli or Staphylococcus aureus. Without G-CSF, E. coli and S. aureus produced similar (p = NS) mortality rates (36 versus 38%) and serial changes in mean circulating neutrophil counts (CNC), but differing mean (+/- SE) tumor necrosis factor (TNF) levels (E. coli, 259 +/- 104 versus S. aureus, 51 +/- 17 pg/ml, p = 0.01). G-CSF prior to bacteria increased mean CNC more than six times compared with placebo (p = 0.001). However, with G-CSF in the first 6 h after E. coli, there was a greater than 20-fold decrease in mean (+/- SE) CNC (x 10(3)/ mm3) to below placebo (0.5 +/- 0.1 versus 0.8 +/- 0.1), whereas with G-CSF after S. aureus, there was only a fivefold decrease in mean CNC and CNC were greater than placebo (1.8 +/- 0.2 versus 0.8 +/- 0.1) (E. coli versus S. aureus decrease in CNC with G-CSF, p = 0.001). With E. coli, G-CSF worsened oxygenation and increased bacteremia and mortality, whereas with S. aureus, G-CSF improved oxygenation and decreased bacteremia and mortality (G-CSF therapy, E. coli versus S. aureus, p = 0.03, 0.05, and 0.001, respectively). Thus, during S. aureus pneumonia with low TNF levels, G-CSF increased CNC and bacterial clearance, resulting in less pulmonary injury and decreased death. During E. coli pneumonia with high TNF levels, G-CSF paradoxically decreased CNC, resulting in impaired bacterial clearance and worsened pulmonary injury and death. Bacterial species and the associated inflammatory mediator response can alter outcome with prophylactic G-CSF therapy during pneumonia.

The Dictyostelium MAP kinase kinase DdMEK1 regulates chemotaxis and is essential for chemoattractant-mediated activation of guanylyl cyclase

We have identified a MAP kinase kinase (DdMEK1) that is required for proper aggregation in Dictyostelium. Null mutations produce extremely small aggregate sizes, resulting in the formation of slugs and terminal fruiting bodies that are significantly smaller than those of wild-type cells. Time-lapse video microscopy and in vitro assays indicate that the cells are able to produce cAMP waves that move through the aggregation domains. However, these cells are unable to undergo chemotaxis properly during aggregation in response to the chemoattractant cAMP or activate guanylyl cyclase, a known regulator of chemotaxis in Dictyostelium. The activation of guanylyl cyclase in response to osmotic stress is, however, normal. Expression of putative constitutively active forms of DdMEK1 in a ddmek1 null background is capable, at least partially, of complementing the small aggregate size defect and the ability to activate guanylyl cyclase. However, this does not result in constitutive activation of guanylyl cyclase, suggesting that DdMEK1 activity is necessary, but not sufficient, for cAMP activation of guanylyl cyclase. Analysis of a temperature-sensitive DdMEK1 mutant suggests that DdMEK1 activity is required throughout aggregation at the time of guanylyl cyclase activation, but is not essential for proper morphogenesis during the later multicellular stages. The activation of the MAP kinase ERK2, which is essential for chemoattractant activation of adenylyl cyclase, is not affected in ddmek1 null strains, indicating that DdMEK1 does not regulate ERK2 and suggesting that at least two independent MAP kinase cascades control aggregation in Dictyostelium.

Role of cAMP-dependent protein kinase in controlling aggregation and postaggregative development in Dictyostelium

We have examined the role of cAMP-dependent protein kinase (PKA) in controlling aggregation and postaggregative development in Dictyostelium. We previously showed that cells in which the gene encoding the PKA catalytic subunit has been disrupted (pkacat- cells) are unable to aggregate [S. K. O. Mann and R. A. Firtel (1991). A developmentally regulated, putative serine/threonine protein kinase is essential for development in Dictyostelium. Mech. Dev. 35, 89-102]. We show that pkacat- cells are unable to activate adenylyl cyclase in response to cAMP stimulation due to the inability to express the aggregation-stage, G-protein-stimulated adenylyl cyclase (ACA). Constitutive expression of ACA from an actin promoter results in a high level of Mn(2+)-stimulated adenylyl cyclase activity and restores chemoattractant- and GTP gamma S-stimulated adenylyl cyclase activity but not the ability to aggregate. Similarly, expression of the constitutively active, non-G protein-coupled adenylyl cyclase ACG in pkacat- cells also does not restore the ability to aggregate, although ACG can complement cells in which the ACA gene has been disrupted. These results indicate that pkacat- cells lack multiple, essential aggregation-stage functions. As the mound forms, high, continuous levels of extracellular cAMP functioning through the cAMP serpentine receptors activate a transcriptional cascade that leads to cell-type differentiation and morphogenesis. The first step is the induction and activation of the transcription factor GBF and downstream postaggregative genes, followed by the induction of prestalk- and prespore-specific genes. We show that pkacat- cells induce postaggregative gene expression in response to exogenous cAMP, but the level of induction of some of these genes, including GBF, is reduced. SP60 (a prespore-specific gene) is not induced and ecmA (a prestalk-specific gene) is induced to very low levels. Expressing GBF constitutively in pkacat- cells restores ecmA expression to a moderate level, but SP60 is not detectably induced. Overexpression of PKAcat from the Actin 15 (Act15), ecmA prestalk, and the PKAcat promoters in pkacat- cells result in significant aberrant spatial patterning of prestalk and prespore cells, as determined by lacZ reporter studies. Our studies identify new, essential regulatory roles for PKA in mediating multicellular development.

Respiratory function and treatment in dogs with acute respiratory distress syndrome: 19 cases (1985-1993)

OBJECTIVE

To characterize respiratory function and treatment in dogs with findings compatible with those of human adult respiratory distress syndrome (ARDS) and to evaluate the application in dogs of clinical for diagnosis of ARDS.

DESIGN

Retrospective review of medical records.

ANIMALS

19 dogs with acute respiratory distress syndrome.

RESULTS

Arterial blood pH was 7.30 +/- 0.59 (mean +/- SD). Nine dogs had metabolic acidosis. In nonmechanically ventilated dogs, PaCO2 was 15.0 to 54.9 mm of Hg. Respiratory acidosis developed in 2 mechanically ventilated dogs. Hypoxemia was observed in 4 of 5 dogs breathing room air. In 4 mechanically ventilated dogs, oxygenation was inadequate, despite use of > 60% inspired O2 and positive end-expiratory pressure in 3 dogs. Alveolar-to-arterial oxygen tension gradients were widened in 4 dogs breathing room air and in 6 dogs ventilated with 100% O2. Ten dogs were mechanically ventilated; ventilatory rate was 18 to 60 breaths/min. Tidal volume was 12 +/- 3.8 ml/kg of body weight in 4 dogs, minute ventilation > 400 ml/kg/min in 2 dogs, and peak airway pressures > 25 cm of H2O in 6 dogs. Positive end-expiratory pressure was used in 8 dogs. Pneumothorax was detected in 5 ventilated dogs. Human clinical criteria for diagnosis of ARDS were fulfilled in 7 dogs. Fluid treatment consisted of IV crystalloids and synthetic colloids. Drugs most often administered were antibiotics and loop diuretics.

CLINICAL IMPLICATIONS

Human clinical criteria for identification of ARDS may be helpful in diagnosis of acute respiratory distress syndrome in dogs.

Clinical and clinicopathologic findings in dogs with acute respiratory distress syndrome: 19 cases (1985-1993)

OBJECTIVE

To describe clinical and clinicopathologic findings from dogs with histologic pulmonary lesions consistent with human adult respiratory distress syndrome and to identify potential factors.

DESIGN

Retrospective study.

ANIMALS

19 dogs with acute respiratory distress.

PROCEDURE

Medical records of dogs were reviewed. Signalment, physical examination and clinicopathologic findings at admission, and thoracic radiographic and necropsy findings were recorded.

RESULTS

The most common clinical sign was dyspnea. Respiratory rate ranged from 36 to 140 breaths/min and abnormal breathing patterns were detected. Crackles were auscultated in 7 dogs. Severe diffuse interstitial and alveolar infiltrates were observed on thoracic radiography in 9 dogs shortly after arrival and developed later in 4 dogs. Four dogs were leukopenic and neutropenic. Disseminated intravascular coagulation was diagnosed in 2 dogs, and hypoalbuminemia was found in 8 dogs. Respiratory status deteriorated rapidly in all dogs, and 10 dogs were mechanically ventilated. Death was attributed solely to respiratory failure in 8 dogs. In the other 11 dogs, severe lesions in nonpulmonary organs, sepsis, or both may have contributed to death. The most common associated conditions that may have contributed to acute respiratory failure were microbial pneumonia, sepsis, aspiration pneumonia, and shock, with more than 1 factor found in 11 of 19 dogs.

CLINICAL IMPLICATIONS

The index of suspicion for acute respiratory distress syndrome should be high in dogs with bilateral pulmonary infiltrates and acute respiratory distress that rapidly progresses to failure.

Effect of inflammation on the rabbit hepatic cytochrome P-450 isoenzymes: alterations in the kinetics and dynamics of tolbutamide

In order to determine the effect of inflammation on the kinetics and dynamics of tolbutamide, two groups of seven and nine New Zealand rabbits received 50 mg/kg tolbutamide before and 48 hr after the production of an inflammatory reaction generated by the s.c. administration of turpentine in both hind legs. Tolbutamide in plasma and its two major metabolites (hydroxytolbutamide) and carboxytolbutamide in urine were assayed by high-performance liquid chromatography. The influence of inflammation on hepatic cytochrome P-450 was assessed by 1) determining the hepatic concentration in cytochrome P-450 and b5, 2) characterizing the activity of tolbutamide hydroxylase, 3) isolating hepatic microsomal protein bands by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 4) measuring the concentrations of hepatic cytochrome P-450 isozymes LM-2 and LM-3c. The inflammatory reaction induced a marked decrease in tolbutamide total body clearance, secondary to a reduction in its metabolic clearance. Concerning the metabolites, hydroxytolbutamide metabolic rate constant and the fraction of the dose recovered in urine as carboxytolbutamide were diminished. Tolbutamide hypoglycemic response was not significantly affected by the inflammatory process. The Vmax of tolbutamide hydroxylase was reduced from 14.6 +/- 2.3 to 5.6 +/- 1.4 nmol/mg/60 min (P less than .05), and the Km remained unchanged. The concentration of hepatic cytochrome P-450 was reduced in turpentine-treated rabbits, whereas the cytochrome b5 concentration remained the same in both groups. The systemic inflammation also reduced the content in the 48, 52, 54 and 60 kDa protein bands from hepatic microsomes and the concentration of the LM-3c form.(ABSTRACT TRUNCATED AT 250 WORDS)

Studies on fibronectin in inflammatory vs non-inflammatory polymorphonuclear leucocytes of patients with rheumatoid arthritis. I. Immunofluorescent and flow cytometric analysis

Using indirect immunofluorescence and flow cytometry, we studied the reactivity of an antibody to human fibronectin with human polymorphonuclear leucocytes (PMNL). Our main objective was to compare the intensity of reaction of this antibody with inflammatory vs non-inflammatory PMNL. We used peripheral blood PMNL as a source of non-inflammatory cells and PMNL isolated from the synovial fluid of patients with rheumatoid arthritis as a source of inflammatory cells. Our findings revealed considerably brighter staining of the inflammatory PMNL. Using flow cytometry as a method of measurement, a difference in fluorescence intensity of at least 40 channels (log scale) was observed in all 12 patients studied when comparing peripheral blood with synovial fluid PMNL. In inflammatory PMNL, fibronectin was found both at the intracellular and membrane levels of the cell whereas fibronectin could be detected only intracellularly in non-inflammatory PMNL.

Malakoplakia of testis

Two cases of malakoplakia of the testis are reported. Ultrastructural studies were performed in both cases and confirmed the histiocytic nature of the large cells seen in this granulomatous process. Characteristic Michaelis-Gutmann bodies are identified in those macrophages and seem to originate from altered lysosomes. From these observations and a review of the literature, the possible physiopathogenesis of the disease is summarized, and comments are made on the treatment of malakoplakia.

Transformation of rat fibroblasts by cloned defective polyoma DNA

Defective polyoma DNA molecules isolated from mouse cells infected with high-multiplicity-passaged virus were cloned in pBR322, and the recombinant plasmids were tested for their capacity to transform Fischer rat 3T3 cells in culture. Recombinants carrying an intact proximal portion of the early region, i.e., the region coding for both small and middle T antigens, were able to induce the transformed phenotype. A recombinant plasmid containing a defective polyoma genome with a deletion of about 300 base pairs in the region coding for the C-terminal segment of middle T antigen failed to transform.