Intravenous Dabigatran Provides Adequate Anticoagulation for Cardiopulmonary Bypass Using a Rabbit Model.

BACKGROUND: Heparin anticoagulation has been used successfully for cardiopulmonary bypass (CPB). However, an alternative anticoagulant approach is desirable due to the cases of heparin-induced thrombocytopenia. Dabigatran provides anticoagulation for an in vitro model of simulated CPB. The current analysis tests the hypothesis that dabigatran provides sufficient anticoagulation for CPB in intact rabbits. METHODS: Nonlinear mixed effects models were used to estimate dabigatran parameters for a two-compartment pharmacokinetic model in 10 New Zealand White rabbits. A dabigatran infusion designed to maintain a plasma concentration of 90 µg/ml was run throughout CPB based on the pharmacokinetics. Animals were subjected to sternotomy and anticoagulated with IV dabigatran (six animals) or heparin (four animals). Rabbits were cannulated centrally using the right atrium and ascending aorta and CPB was maintained for 120 min. Measurement of activated clotting time, thromboelastometric reaction time, and blood gases were performed during CPB. Then, the animals were euthanized, and the brain and one kidney were removed for histology. Sections of the arterial filters were inspected using electron microscopy. RESULTS: The observed dabigatran concentrations during CPB were greater than the target concentration, ranging from 137 ± 40 µg/ml at 5 min of CPB to 428 ± 150 µg/ml at 60 min, and 295 ± 35 µg/ml at 120 min. All rabbits completed 2 h of CPB without visible thrombosis. In the two groups, reaction time values were elevated, reaching 10,262 ± 4,198 s (dabigatran group) and 354 ± 141 s (heparin group) at 120 min of CPB. Brains and kidneys showed no evidence of thrombosis or ultrastructural damage. Sections of the arterial line filter showed minimal or no fibrin. There was no significant difference in outcomes between dabigatran- and heparin-treated animals. CONCLUSIONS: In this first-use, proof-of-concept study, the authors have shown that dabigatran provides acceptable anticoagulation similar to heparin to prevent thrombosis using a rabbit CPB model.

Validation of the Slovak version of the Wijma Delivery Expectancy/Experience Questionnaire (W-DEQ), version A.

AIM: This study aimed to assess the psychometric characteristics of the Slovak translation of the version A of Wijma Delivery Expectancy/Experience Questionnaire (SW-DEQ) among healthy Slovak pregnant women. METHOD: Exploratory factor analysis (EFA) of the SW-DEQ was performed. Several coefficients of internal consistency were employed for the whole scale as well as for separate factors. Concurrent/convergent validity was assessed by correlation analysis of the overall SW-DEQ score with State-Trait Anxiety Inventory, Eysenck Personality Inventory - subscales Neuroticism and Extraversion, as well as with adjusted versions of Beck Depression Inventory and Internal-External Locus of Control Scale. EFA yielded seven factors: 'lack of composure', 'negative appraisal', 'lack of self-efficacy', 'lack of positive anticipation', 'fear and hopelessness', 'loneliness', and 'concern for the child'. RESULTS: The Cronbach's α of the whole scale was .93, while for the separate factors, it ranged between .68 and .87. The sum score of SW-DEQ correlated weakest with extraversion (in nulliparous women) and locus of control (in multiparous women), and strongest with trait anxiety (in both groups). CONCLUSIONS: The Slovak version could be considered a valid and reliable measure of fear of childbirth among pregnant Slovak women. However, the dimensional structure of the measure warrants further confirmation (Tab. 7, Ref. 33).

Seroepidemiology of Toxoplasma in a coastal region of Haiti: multiplex bead assay detection of immunoglobulin G antibodies that recognize the SAG2A antigen.

Toxoplasma gondii is a globally distributed parasitic protozoan that infects most warm-blooded animals. We incorporated a bead coupled with recombinant SAG2A protein into our Neglected Tropical Disease (NTD) multiplex bead assay (MBA) panel and used it to determine Toxoplasma infection rates in two studies in Haiti. In a longitudinal cohort study of children aged 0-11 years, the infection rate varied with age reaching a maximum of 0·131 infections/year in children aged 3 years [95% confidence interval (CI) 0·065-0·204]. The median time to seroconversion was estimated to be 9·7 years (95% CI 7·6-∞). In a cross-sectional, community-wide survey of residents of all ages, we determined an overall seroprevalence of 28·2%. The seroprevalence age curve from the cross-sectional study also suggested that the force of infection varied with age and peaked at 0·057 infections/year (95% CI 0·033-0·080) at age 2·6 years. Integration of the Toxoplasma MBA into NTD surveys may allow for better estimates of the potential burden of congenital toxoplasmosis in underserved regions.

Outcome analysis of coronary artery bypass grafting: minimally invasive versus standard techniques.

Minimally invasive coronary artery bypass grafting (MIDCAB) procedures are purported to result in improvements in patient management over standard techniques. A comparative study was performed on risk-stratified patients treated with either technique. Following institutional review board approval, a retrospective random chart review was conducted on 27 MIDCAB and 37 standard coronary artery bypass grafting (CABG) patients who were operated on over a 12-month period at the University of Nebraska Medical Center. Risk stratification was accomplished by dividing the two patient populations, MIDCAB and 'standard', into one of four subgroups based on a preoperative risk score. Risk stratification was achieved by dividing the patient populations into one of four subgroups: good, fair, poor and high risk. Both groups received similar operations and surgical interventions, except for the inclusion of cardiopulmonary bypass (CPB). Approximately 200 parameters were collected and analyzed in the following categories: anthropometric, operative and postoperative outcomes. The MIDCAB group had a significantly lower number of vessels bypassed (2.0+/-0.7 vs 3.4+/-0.9, p < 0.0001). Total postoperative blood product transfusions trended higher in the standard group (6.1+/-12.6 U) when compared to the MIDCAB patients (2.3+/-5.5 U, p < 0.15), although not statistically significant. Postoperative inotrope use was significantly less in the MIDCAB group (19% vs 59%, p < 0.002). Ventilator time in the MIDCAB group was 10.5+/-5.4 h vs 15.0+/-12.3 h in the standard group (p < 0.07). The MIDCAB group had an overall greater length of stay, but was only statistically different within the poor-risk subgroup (12.2+/-10.7 vs 7.5+/-3.9, p < 0.04). The results of this study show that when CPB is not utilized in treating patients undergoing CABG procedures, the benefits in regards to patient outcomes are unclear. This necessitates the need for further work when comparing outcomes for risk-stratified patients.

Cardioplegia flow dynamics in an in vitro model.

The flow of fluids in extracorporeal circuits does not conform to conventional Poiseuille mechanics which confounds calculating cardioplegia (CP) flow distribution. The purpose of this study was to quantify CP flow dynamics in a model simulating coronary atherosclerosis across varying sized restrictions. An in vitro preparation was designed to assess hydraulic fluid movement across paired restrictions of 51, 81 and 98% lumen reductions. Volume data were obtained at variable flow, temperature, viscosity and pressure conditions. CP delivered through 14- and 18-gauge (GA) conduits at 8 degrees C and 100 mmHg infusion pressure revealed that both four to one and crystalloid CP solutions had significantly less total percentage flow through the 14-GA conduit, p < 0.0001 and p < 0.001, respectively. Overall, 4:1 CP exhibited the most favorable fluid dynamics at 8 degrees C in that it delivered the highest percentages of total CP flow through the smaller lumen conduit. At both 8 degrees C and 37 degrees C delivery, blood CP resulted in the least homogeneous fluid distribution at all delivery parameters. The results in relation to blood viscosity indicate that, although the 8 degrees C blood CP had a significantly greater viscosity than 37 degrees C blood CP, it did not produce an effect in fluid distribution. These data show that increasing the cardioplegic solution hematocrit causes an inhomogeneous fluid distribution regardless of delivery temperature or infusion pressure.

Removal of hepatocarcinoma cells from blood via cell washing and filtration techniques.

Utilization of autotransfusion during tumor resection remains controversial due to viability of carcinoma cells remaining in collected blood. The purpose of this study was to evaluate autotransfusion techniques combined with leukocyte depleting filters (LDF) for removal of hepatocarcinoma cells from autotransfusate. An in vitro model was created by contaminating expired human erythrocytes with cultured hepatocarcinoma (HEP G2) cells. Autotransfusion devices evaluated were Cobe BRAT2, Sorin STAT-P, and Fresenius CATS. Autotransfusate collected from varying processing conditions were filtered using the Pall Leukoguard RS or Pall Purecell RCQ LDF. Carcinoma concentrations were quantified via Coulter Counter technology. The CATS exhibited higher concentrations of cancer cells in the autotransfusate prior to washing, a 449% increase. This was significantly higher than either the BRAT2 or STAT-P, 350% and 315% respectively. Post washing HEP G2 concentrations in the BRAT2 were significantly higher than the STAT-P and CATS. Doubled wash volumes removed more HEP G2 cells in all trials, reaching statistical significance only in the CATS. LDF resulted in a significant 75% reduction of HEP G2 cells, with no difference between filters. While combination use of autotransfusion devices and leukocyte depleting filters did result in a product with concentrated hematocrit, no technique removed all hepatocarcinoma cells.

Cultural diagnosis of chancroid.

Culture of Haemophilus ducreyi remains the definitive way to diagnose chancroid. Since its discovery in 1889, cultural isolation of this fastidious organism has been a challenge for clinicians and microbiologists. A recent chancroid epidemic in our locale prompted a review of available culture techniques. Despite the development of various selective solid media in the last 20 years, cultural diagnosis of chancroid remains problematic. Many pitfalls may complicate this procedure, such as concomitant syphilis, syphilis, or herpes progenitalis simulating chancroid, strain differences in nutritional requirements, improper handling and delayed inoculation of clinical specimens, use of suboptimal growth conditions, and vancomycin hydrochloride-sensitive organisms. Highest cultural yield will be obtained by using enriched gonococcal agar base and enriched Müeller-Hinton agar in a biplate fashion. As most isolates are sensitive to vancomycin, incorporation of this antibiotic should be routine. However, screening for vancomycin-sensitive organisms is indicated when negative cultures are repeatedly obtained from clinically typical cases originating from the same community. Development of immunodiagnostic and DNA probe tests is underway.

Anetodermic cutaneous changes overlying pilomatricomas.

Five pilomatricomas with anetodermic cutaneous changes and striae are presented. Pink to translucent, atrophic, scarlike skin that covers a typical pilomatricoma occurs most commonly in young women. Histopathologic examination showed an atrophic, edematous dermis with diminished, fragmented collagen fibers and absent elastic tissue.

Cutaneous larva migrans due to Pelodera strongyloides.

A twenty-year-old landscape worker was evaluated for a widespread cutaneous eruption consisting of papules, pustules, and burrows. Cutaneous scrapings revealed live and dead larvae of a free-living soil nematode, Pelodera strongyloides. This is the third instance of human dermatitis due to this organism, and the first reported in an adult host.

Cystic fibroepithelioma of pinkus.

A 59-year-old female with a cystic fibroepithelioma of Pinkus is presented. The clinical and histopathological features of this unusual variant of basal cell carcinoma are discussed.

Low thymosin alpha-1 concentrations in patients chronically infected with the hepatitis B virus.

Serum concentrations of thymosin alpha-1 (TA-1), an immunoregulatory peptide, were assayed in patients with chronic hepatitis B infection and volunteer blood donor controls. Coded samples were tested using a radioimmunoassay. The TA-1 concentrations in HBsAg-positive patients averaged 1555 pg/ml, whereas in the control group, the mean TA-1 in serum was 2159 pg/ml (P less than 0.001). Similar results were found for age- and sex-matched pairs. The TA-1 concentration was not associated with HBe antigen/antibody status or with values of liver-associated enzymes. Analysis of T-cell subsets in nine HBsAg carriers revealed significantly decreased CD4 (helper)-cells, both in absolute numbers and as the percentage of total lymphocytes present. These data suggest that individuals with chronic hepatitis B infection have a relative deficiency of the immunomodulatory peptide TA-1, which may contribute to the characteristics of the resultant T-cell population.

Pluripotentiality of the 2-day-old avian germinative neuroepithelium.

In a previous study using chick/quail chimeric embryos with homotopic transplants (Martinez & Alvarado-Mallart, 1989b), we have delimited in the 2-day-old avian embryo the areas of the neural tube giving rise to optic tectum and mesencephalic grissea as well as to isthmic grissea and cerebellum: respectively, "mesencephalic" and "metencephalic" alar plates. To investigate the determination or the competence of these areas, portions of these germinative neuroepithelia from a quail embryo were transplanted in substitution for other areas of the chick neural tube. The analysis of the chimeric brains was done by comparing alternating transverse sections stained for cytoarchitecture and with two different techniques to recognize transplanted versus host cells: either the Feulgen and Rossenbeck DNA histochemical reaction and/or immunohistochemical methods with a monoclonal antibody recognizing quail but not chick cells. The eventual visual innervation of the quail graft was analyzed in many cases by injecting anterograde axonal tracers in the eye contralateral to the graft. The results are as follows: (1) caudal metencephalon transferred to mesencephalon maintained in all cases its presumptive cerebellar phenotype, whereas (2) rostral metencephalon transferred to mesencephalon changed its fate to a tectal phenotype but maintained its cerebellar fate when transferred to diencephalon; (3) caudal mesencephalon maintained its tectal fate in 65% of the cases when transferred to diencephalon, whereas (4) rostral mesencephalon transferred to a cerebellar domain changed its fate and became influenced by the surrounding structures in all cases, but only in 85% of the cases when it was transplanted to diencephalon; (5) the in situ host diencephalon, isolated from its normal environment by a mesencephalic graft, is competent to change its fate and express a mesencephalic phenotype. These results demonstrate that at least some regions of the germinative neuroepithelium from either metencephalon, mesencephalon, and diencephalon are still pluripotent in the 2-day-old avian embryo and that their fate seems to be under the influence of the surrounding structures. Rostral mesencephalon and rostral metencephalon have been more easily influenced by environmental factors than their caudal counterparts, suggesting that regions providing instructive positional factors exist within the 2-day-old germinative neuroepithelium. These regions might play an important role in the determination of the various segments of the neural tube.

Double-blind, placebo-controlled trial of a herpes simplex virus type 2 glycoprotein vaccine in persons at high risk for genital herpes infection.

To determine the efficacy of a herpes simplex virus type 2 (HSV-2) glycoprotein subunit vaccine, vaccine (50 micrograms) or placebo was administered intramuscularly at weeks 0, 4, and 22 to 161 persons who lacked HSV-2 antibodies and were sex partners of persons with recurrent genital herpes. The annual rate of acquisition of HSV infection was similar among vaccine and placebo recipients (10.7% and 8%, respectively) but was higher in initially seronegative subjects (15.5%) than in those with HSV-1 at entry (5.9%). Eleven (79%) of the 14 HSV infections acquired during follow-up were symptomatic. Vaccination elicited ELISA antibody titers to glycoproteins gD2 and gB2 that were only 10% and 5%, respectively, of titers found in persons with recurrent genital HSV-2 infection. This vaccine failed to provide protection from acquisition of genital HSV infection. The lack of efficacy appears to be related, in part, to the poor immunogenicity of the vaccine.

Effects of exercise and exercise conditioning on blood platelet function.

The effects of exercise and exercise conditioning on blood platelet function were investigated in six healthy individuals who had not engaged in regular exercise for at least 1 yr prior to the study. The subjects (three men and three women) had a mean age of 28 (range 23-32) and participated in a supervised program of treadmill exercise. Subjects exercised for 20 min, three times weekly, for 12 wk at 70-80% of estimated maximum heart rate. Samples for platelet counts, platelet aggregation, and plasma beta-thromboglobulin (beta-TG) were obtained prior to training and after 6 and 12 wk of training. All subjects responded with an increase in aerobic capacity during training. Resting mean systolic and diastolic blood pressures decreased after training (P less than 0.05). Platelet counts increased after exercise, and the increment in week 12 exceeded that in the 1st wk by 57%. Platelet aggregation studies in platelet rich plasma (PRP) showed an increase in slope after exercise (week 1, P less than 0.05) which decreased with training (week 1 vs week 12, P less than 0.01). Aggregation studies utilizing impedance aggregometry in diluted native whole blood showed an acceleration of both spontaneous aggregation (P less than 0.01 weeks 6 and 12) and aggregation using epinephrine as an agonist (P less than 0.05) following exercise. Plasma beta-TG levels did not increase significantly after exercise; however, resting concentrations of beta-TG decreased with training (P less than 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of heat shock proteins by isolated mouse spermatogenic cells.

Proteins of the hsp70 family are abundant in mouse spermatogenic cells. These cells also synthesize relatively large amounts of a 70,000-molecular-weight protein (P70) that appears to be a cell-specific isoform of hsp70, the major heat-inducible protein (R.L. Allen, D.A. O'Brien, and E.M. Eddy, Mol. Cell. Biol. 8:828-832, 1988). In this study, proteins of unstressed and heat-stressed spermatogenic cells consisting of purified preparations of preleptotene, leptotene-zygotene, pachytene spermatocytes, and round spermatids were analyzed by two-dimensional polyacrylamide gel electrophoresis. Unstressed preleptotene and leptotene-zygotene spermatocytes contained little P70, whereas relatively large amounts of P70 were present in pachytene spermatocytes and round spermatids. Labeling studies showed that P70 was synthesized primarily in pachytene spermatocytes and that little synthesis occurred in round spermatids or in preleptotene and leptotene-zygotene stages of spermatogenesis. Synthesis of hsp70 was not detectable in unstressed cells but was induced in all stages of isolated germ cells following heat stress. These results indicate that P70 is expressed in a stage-specific manner during cell differentiation, whereas hsp70 is synthesized in response to stress in all populations of isolated spermatogenic cells examined.

Long-term acyclovir suppression of frequently recurring genital herpes simplex virus infection. A multicenter double-blind trial.

Normal adults with six or more episodes of genital herpes in the previous year were enrolled in a one-year, multicenter, double-blind trial comparing placebo with 400 mg of acyclovir administered orally twice daily. Patients with episodes during the study were offered 200 mg of acyclovir administered orally five times daily for five days; this allowed comparison of suppressive and episodic treatment. After one year, 227 (44%) of 519 patients receiving suppressive treatment and seven (2%) of 431 receiving placebo (episodic) treatment remained free of recurrences, and the mean numbers of recurrences per year were 1.8 and 11.4, respectively. Among 67 patients who had received suppressive therapy for one year, the mean duration of lesions in the first episode following the discontinuation of treatment was 9.3 days compared with 7.3 days among 45 patients who had received episodic therapy for one year. Treatment was well tolerated, and no changes were noted in the in vitro susceptibility to acyclovir of herpes simplex virus cultured during or after the one-year trial. Continuous or episodic oral acyclovir therapy for one year remained safe and effective.

Diagnosis of pneumococcal pneumonia.

Pneumococcal pneumonia presents peculiar problems to the diagnostician. It is at once the most common form of community-acquired bacterial pneumonia and simultaneously the most difficult to document microbiologically. Bacteremia, empyema, meningitis, or septic arthritis due to S pneumoniae unmistakably verifies this bacterium as the cause of a coexistent pneumonia; this coexistence fortunately occurs infrequently. The diagnostic dilemma arises in the less sick patient. While recognizing the common presence of pneumococci in the oropharynx of healthy individuals, we give undue credence to S pneumoniae cultured from sputum obtained by expectoration. At the same time, pneumococci are frequently not found in cultures of sputum obtained from patients with confirmed bacteremic disease. More invasive techniques (transtracheal aspiration, protected bronchoscopic catheter, lung needle aspiration) are too complex, dangerous, or both for routine use. Attempts to detect pneumococcal antigen in blood, sputum, or urine by modern immunologic techniques give promise of avoiding the problems of either contamination or lack of bacteriologic growth. However, they have not yet been evaluated in sufficiently large groups with pneumonia of independently determined bacterial etiology to calculate test sensitivity and specificity. At the present time then, the careful clinician will use all the epidemiologic and clinical evidence at hand, including a careful Gram's stain and culturing of sputum, blood, and other sources, to arrive at the most likely etiology. The probabilities must be weighed in light of the imprecision of current laboratory confirmation and modified by clinical course. Choice of antimicrobial therapy still favor penicillin for patients with community pneumonia severe enough to warrant hospitalization, despite ominous trends in multiple resistance of S pneumoniae.

Subclass distribution of human IgG autoantibodies in pemphigus.

The distribution of IgG subclasses in the intercellular substance (ICS) reactive autoantibodies in serum of 10 patients with pemphigus was analyzed by semiquantitative indirect immunofluorescence (IF) using the HP series of monoclonal antibodies specific for the four human IgG subclasses. IgG4 ICS specific autoantibody was present in all 10 sera at a titer of 10 to 320, while IgG1 antibodies were found in 9 of 10 sera at a seemingly lower level. IgG3 autoantibodies were detected in the serum of one patient, only after isolation of IgG using ion-exchange chromatography. Autoantibodies of IgG subclass 2 were not detectable in any of the 10 sera tested. One of the ten patients displayed circulating anti-ICS antibodies of only the IgG4 isotype.