CDC group O-3: phenotypic characteristics, fatty acid composition, isoprenoid quinone content, and in vitro antimicrobic susceptibilities of an unusual gram-negative bacterium isolated from clinical specimens

Between 1983 and 1994, 13 phenotypically similar unidentified clinical isolates were received by the Special Bacteriology Reference Laboratory, Centers for Disease Control and Prevention (CDC). Sources included blood (four strains), lung (three strains), knee fluid and duodenal tissue (one strain each), bone, and lymph node tissue (two strains each). All were aerobic glucose-oxidizing, slender, long, curved gram-negative rods that utilized xylose, sucrose, and maltose; did not grow on MacConkey agar in 1 to 2 days; were oxidase positive; hydrolyzed esculin; and grew on Campylobacter selective medium. All were negative for urease, indole, nitrate reduction, and gelatin hydrolysis. All were motile by means of a single polar flagellum with a noticeably short wavelength; however, motility was sometimes difficult to demonstrate. The cellular fatty acid compositions of these strains, as analyzed by gas-liquid chromatography, were unique, characterized by relatively large amounts of 16:1omega7c, 16:0, and 18:1omega7c with smaller amounts of 12:0, 3-OH-12:1, 14:0, 15:0, 18:0, Br-19:1, and 19:0cyc11-12. High-performance liquid chromatography and mass spectrometry of the quinone extracts of three representative strains showed ubiquinone-10 as the major component. Based on the breakpoints for the family Enterobacteriaceae, all the strains were susceptible in vitro to aminoglycosides, sulfamethoxazole-trimethoprim, and chloramphenicol but were resistant to most beta-lactams except imipenem. The MICs of amoxicillin-clavulanate and ciprofloxacin for these strains clustered around the breakpoints, which makes it difficult to predict the strains' response in vivo to these agents. This group has been designated CDC oxidizer group 3 (O-3).     

Binding of Ca2+ and Zn2+ to human nuclear S100A2 and mutant proteins

The Ca2+-binding protein S100A2 is an unusual member of the S100 family, characterized by its nuclear localization and down-regulated expression in tumorigenic cells. In this study, we investigated the properties of human recombinant S100A2 (wtS100A2) and of two mutants in which the amino-terminal Ca2+-binding site I (N mutant) and in addition the carboxyl-terminal site II (NC mutant) were replaced by the canonical loop (EF-site) of alpha-parvalbumin. Size exclusion chromatography and circular dichroism showed that, irrespective of the state of cation binding, wtS100A2 and mutants are dimers and rich in alpha-helical structure. Flow dialysis revealed that wtS100A2 binds four Ca2+ atoms per dimer with pronounced positive cooperativity. Both mutants also bind four Ca2+ atoms but with a higher affinity than wtS100A2 and with negative cooperativity. The binding of the first two Ca2+ ions to the N mutant occurred with 100-fold higher affinity than in wtS100A2 and a 2-fold increase for the last two Ca2+ ions. A further 2-3-fold increase of affinity was observed for respective binding steps of the NC mutant. The Hummel-Dryer method demonstrated that the wild type and mutants bind four Zn2+ atoms per dimer with similar affinity. Fluorescence and difference spectrophotometry showed that the binding of Ca2+ and Zn2+ induces considerable conformational changes, mostly attributable to changes in the microenvironment of Tyr76 located in site II. Fluorescence enhancement of 4,4'-dianilino-1, 1'-binaphthyl-5,5'-disulfonic acid clearly indicated that Ca2+ and Zn2+ binding induce a hydrophobic patch at the surface of wtS100A2, which, as in calmodulin, may be instrumental for the regulatory role of S100A2 in the nucleus.     

Effect of valproic acid on sodium currents in cortical neurons from patients with pharmaco-resistant temporal lobe epilepsy

In a selected group of temporal lobe epilepsy patients with seizures refractory to pharmacological treatment, pharmacological seizure control can be attained by surgical resection of the epileptic zone. We investigated to what extent pharmaco-resistance is reflected in a reduced response at the cellular level, in neurons acutely isolated from the temporal cortex resected in 20 patients. We studied the effect of valproic acid (VPA) on the transient sodium current, measured under whole-cell voltage-clamp conditions. We compared neurons from patients with temporal lobe sclerosis (S) with neurons from patients without hippocampal sclerosis (nS) and compared hippocampal CA1 neurons (CA) with neocortical neurons (NC). We could not detect differences in the voltage dependence and kinetics of sodium current activation and inactivation in any of the group comparisons. VPA shifted the voltage dependence of steady-state inactivation (expressed as V(h,i) in a Boltzmann fit) to more hyperpolarized levels. The shift induced by 2 mM VPA was -5.1 +/- 0.7 mV in CA-S (n = 13), -5.1 +/- 0.7 mV in CA-nS (n = 25), -4.3 +/- 0.5 mV in NC-S (n = 17) and -4.9 +/- 0.5 mV in NC-nS (n = 16) The relation between concentration and voltage shift had an EC50 of 1.4 +/- 0.2 mM VPA (n = 16) and a maximal shift of 9.6 +/- 0.9 mV. We conclude that pharmaco-resistance in these patients is not associated with a changed modulation of the sodium current by VPA. Results are discussed in the light of a reduced sodium current modulation by carbamazepine in CA1 neurons of patients with hippocampal sclerosis and of similar observations in the kindling model of epileptogenesis.     

An ultrastructural study of the retention hyperkeratosis of experimentally induced comedones in rabbits: the effects of three comedolytics

The precise pathologic processes of comedo formation in acne are not well understood. Retention hyperkeratosis may play an important role. To evaluate the effects of three topical comedolytics, 20% azelaic acid, 0.1% tretinoin and 5% benzoyl peroxide, on the retention hyperkeratosis of experimentally induced comedones (EIC), an ultrastructural study was done. After formation of EIC with 50% oleic acid in paraffin oil on the external ears of rabbits, each comedolytic was applied for 4 weeks. Biopsies were taken every week and, using a Hitachi H-600 transmission electron microscope, morphologic observations were done in the upper portion of the follicular epithelium. In EIC, after application of each comedolytic, the markedly thinned horny layer was loosely adhered by extremely few desmosomes and desmosomal bodies. The number and size of tonofilaments and keratohyaline granules decreased, but the number of variable sized Odland bodies increased in the upper epidermis. These findings appeared 1 week after application of either azelaic acid or benzoyl peroxide, and 3 weeks after application of tretinoin. For the first 2 weeks of tretinoin application, EIC showed rather compact hyperkeratosis with more desmosomes and desmosomal bodies than before. Azelaic acid tretinoin and benzoyl peroxide increased the number of Odland bodies, and the horny cells became less adhesive. This lysis of retention hyperkeratosis resulted in comedolysis. During 4 weeks of treatment with these three comedolytics, only tretinoin normalized the keratinization process.     

Inhaled nitric oxide prevents left ventricular impairment during endotoxemia

PURPOSE: This study provides estimates of the effect of tamoxifen treatment on mortality from four conditions known to be affected by tamoxifen in women who survive their breast cancer: contralateral breast cancer, cardiovascular events, endometrial cancer, and thromboembolic events. These estimates are in addition to tamoxifen's impact on primary breast cancer mortality. METHODS: The effects of tamoxifen were calculated by the use of the published relative risk (RR) rates of the four conditions as affected by adjuvant tamoxifen and their application to the respective Canadian age-specific mortality rates for the same conditions. The final mortality impact of tamoxifen was expressed as net mortality difference between users and nonusers of tamoxifen. RESULTS: At 10 years of follow-up, the sum of avoided deaths (contralateral breast cancer, cardiovascular events) and excess deaths (uterine cancer, thromboembolic episodes) resulted in an overall (net) mortality reduction because of tamoxifen use, with 3 to 41 avoided deaths per 1,000 tamoxifen-treated patients who were 50 to 80 years of age. With the follow-up projected until the age of 90 years, the numbers of avoided late deaths attributed to tamoxifen ranged from 38 to 56 per 1,000 patients. CONCLUSION: Our calculations that pertain to late breast cancer survivors indicate that there is a more substantial mortality reduction as a result of deaths avoided from contralateral breast cancer and cardiovascular events, despite the moderately increased mortality from endometrial cancer and thromboembolic episodes. The overall tamoxifen-associated mortality reduction occurs, in different magnitudes, in patients of all ages from 50 to 80 years at diagnosis of the primary breast cancer.     

Sequential hemodynamic changes for large volume paracentesis in post-hepatitic cirrhotic patients with massive ascites

Large volume paracentesis (4.8 to 15.5 liters) was performed in 42 patients with post-hepatitic cirrhosis and massive ascites, not only to derive parameters capable of predicting the development of severe clinical hypotension after large volume paracentesis, but also to determine the optimal time to introduce preventive volume expanders. Systemic hemodynamics were sequentially measured for 72 hours in thirty-two patients. Severe clinical hypotension occurred in 13 (31.0%) patients 4-62 hours from the start of paracentesis. Univariate analysis, with the Mantel-Cox test used to compare Kaplan-Meier curves, and the subsequent multivariate analysis by stepwise Cox regression procedure were utilized to identify two variables, withdrawn ascitic fluid greater than 7.5 liters (p = 0.0121) and the absence of peripheral edema (p = 0.0148), reaching statistical significance to predict the occurrence of severe clinical hypotension. Compared to the baseline value, the cardiac output of patients not developing severe clinical hypotension increased (6.26 +/- 0.66 vs. 6.65 +/- 0.69 liter/min, p < 0.01) one hour from the start of paracentesis and right atrial pressure decreased (11.2 +/- 2.4 vs. 8.7 +/- 2.3 mmHg, p < 0.05). The cardiac output returned to the baseline value at the 9th hour. Based on the results presented herein, we can conclude that severe clinical hypotension occurs in a high percentage of patients with post-hepatitic cirrhosis and massive ascites within 72 hours from the start of large volume paracentesis. At potential risk of this occurring are those patients without peripheral edema and withdrawn ascitic fluid greater than 7.5 liters. Volume expanders should be introduced before 4th hour from the start of large volume paracentesis.     

Implications of comorbidity for genetic studies of bipolar disorder: P300 and eye tracking as biological markers for illness

In large families with affective illness, identification of a biological variable is needed that reflects brain dysfunction at an earlier point than symptom development. Eye movement disorder, a possible vulnerability marker in schizophrenia, is less clearly associated with affective illness, although a subgroup of affective disorders shows smooth-pursuit eye movement disorder. The auditory P300 event-related potential may be a useful marker for risk to schizophrenia, but a role in bipolar illness is less certain. The distribution of these two biological variables and their association with symptoms in two multiply affected bipolar families is described. In a single, five-generation family identified for linkage studies through two bipolar I (BPI) probands, 128 members (including 20 spouses) were interviewed. The 108 related individuals had diagnoses of BPI (7), bipolar II (2), cyclothymia (3), or major depressive disorder (19). Eight others had generalised anxiety (1), minor depression (5), intermittent depression (1), or alcoholism (1). Sixty-nine subjects had no psychiatric diagnosis. P300 latency (81) and eye tracking (71) were recorded from a subgroup of relatives within the pedigree. Eye tracking was abnormal in 11 of 71 relatives (15.5%) and was bimodally distributed. In these 11 relatives, clinical diagnoses included minor depression (1), alcoholism (1) and generalised anxiety disorder (1). P300 latency was normally distributed and did not differ from controls. In a second family in which five of seven siblings have BPI illness, P300 latency and eye movement disorder were found in affected relatives and in some unaffected offspring. In these large families, clinical diagnoses of general anxiety, alcoholism and minor depression, when associated with eye tracking abnormality, may be considered alternative clinical manifestations of the same trait that in other relatives is expressed as bipolar illness.     

Electrophysiologic characteristics and anatomical complexities of accessory atrioventricular pathways with successful ablation of anterograde and retrograde conduction at different sites

INTRODUCTION: Catheter ablation may eliminate anterograde and retrograde accessory pathway conduction at closely adjacent but anatomically discrete sites. However, the mechanisms of this discrepancy, the electrophysiologic and anatomical characteristics, and information about systematic study from a large patient population are not available. The purpose of this study was to investigate the electrophysiologic characteristics and anatomical complexities of the accessory pathway in which anterograde and retrograde conduction was successfully ablated at different sites. METHODS AND RESULTS: Thirty-eight (10.9%) patients (19 men and 19 women; mean age 37 +/- 2.4 years) fulfilling the criteria of having separate ablation sites for anterograde and retrograde conduction were designated as group I, and the other 310 patients (215 men and 95 women; mean age 47 +/- 0.6 years) were designated as group II. The patients with right-sided free-wall pathways had the highest incidence (18.6%) of separate ablation sites. The anatomical distance between anterograde and retrograde directions (left anterior oblique view, 13 +/- 0.6 vs 8 +/- 0.9 mm, P < 0.01; right anterior oblique view, 17 +/- 0.6 vs 5 +/- 0.7 mm, P < 0.01), and incidence of conduction impairment in one direction after successful ablation of another direction (15% vs 78%, P < 0.05) differed significantly between left and right free-wall pathways. The mean distances obtained from left (7 +/- 0.4 vs 14 +/- 0.4 mm, P < 0.05) and right (7 +/- 1.1 vs 15 +/- 0.9 mm, P < 0.05) anterior oblique views were shorter in patients who had impairment of conduction properties than those in patients without impaired conduction after successful ablation of one direction. CONCLUSIONS: This study showed that anatomical and functional dissociation of the accessory pathway into anterograde and retrograde components was possible. Further study on the relation between electrophysiologic and pathologic characteristics would be helpful to confirm these findings.     

Elder abuse: a call to action

An estimated 2 million people a year are victims of elder abuse, which ranges from neglect and mistreatment to physical abuse. By the year 2020, a full 22% of the population will be aged 65 or older. This demographic explosion demands that we identify and protect those at risk. To investigate the incidence of elder abuse or neglect (EAN) and to determine clinician awareness of associated risk factors, we conducted a 1-year retrospective review of thermally injured patients aged 60 or older. Data included age, total body surface area burned, mechanism of injury, length of hospital stay, mortality, abuse or neglect risk factors, and referral to the appropriate social agency. We found that our elderly patients (n = 28) were poorly screened for EAN. While 64% to 96% of patients were screened for cognitive impairment, overall health, and financial resources, none were screened for risk factors of emotional isolation. None of the patient's caregivers, including any spouses, roommates, or guardians, were screened for risk factors of substance abuse, familial violence, dependency needs, or external stresses. With the use of available data, we were able to place 11 patients on the following levels of abuse or neglect: 1) low risk for abuse; 2) self-neglect; 3) neglect; and 4) abuse. By this scale, 7 patients (64%) were victims of self-neglect, 3 patients (27%) were victims of neglect, and 1 patient (9%) was a victim of abuse. Adult Protective Services intervened in 2 cases. Recognizing that all cases of EAN should be preventable, we cannot accept the socioeconomic impact of this entity. The 11 patients identified as victims of neglect, self-neglect, or abuse accounted for 135 hospital days and 8 fatalities. Before we can address EAN, health care personnel must be made aware of the problem and routine screening for risk factors must be implemented. The true incidence of EAN is likely underestimated because health care providers have difficulty recognizing its features. A standard assessment tool to screen for neglect or abuse should be used for each older adult admission.