Impairment of spatial but not contextual memory in CaMKII mutant mice with a selective loss of hippocampal LTP in the range of the theta frequency

We assessed hippocampal-dependent memory in mice with a Ca(2+)-independent form of CaMKII generated by the introduction of an aspartate at amino acid 286. The CaMKII-Asp-286 mice show normal LTP at high frequency stimulation, but in the 5-10 Hz range, they show a shift in the frequency-response curve favoring LTD. This range of frequencies is similar to the theta rhythm, which is associated with exploration in rodents. Using the Barnes maze to assess spatial memory, we found the transgenic mice could not learn to navigate to a specific location using spatial cues. In contrast, one line of transgenic mice performed normally in contextual fear conditioning, a task that is also hippocampal dependent. This dissociation between spatial and contextual memory suggests that even though both require the hippocampus, they may be mediated by different synaptic mechanisms.

Genetic and pharmacological evidence for a novel, intermediate phase of long-term potentiation suppressed by calcineurin

To investigate the role of phosphatases in synaptic plasticity using genetic approaches, we generated transgenic mice that overexpress a truncated form of calcineurin under the control of the CaMKIIalpha promoter. Mice expressing this transgene show increased calcium-dependent phosphatase activity in the hippocampus. Physiological studies of these mice and parallel pharmacological experiments in wild-type mice reveal a novel, intermediate phase of LTP (I-LTP) in the CA1 region of the hippocampus. This intermediate phase differs from E-LTP by requiring multiple trains for induction and in being dependent on PKA. It differs from L-LTP in not requiring new protein synthesis. These data suggest that calcineurin acts as an inhibitory constraint on I-LTP that is relieved by PKA. This inhibitory constraint acts as a gate to regulate the synaptic induction of L-LTP.

Inducible and reversible gene expression with the rtTA system for the study of memory

To obtain rapidly inducible and reversible expression of transgenes in the forebrain of the mouse, we have combined the reverse tetracycline-controlled transactivator (rtTA) system with the CaMKIIalpha promoter. We show that doxycycline induces maximal gene expression in neurons of the forebrain within 6 days and that this expression can be reversed by removal of doxycycline. Using calcineurin as a test transgene, we show that doxycycline-induced expression impairs both an intermediate form of LTP (I-LTP) in the hippocampus and the storage of spatial memory. The reversibility of the rtTA system in turn allowed us to examine the effects of the transgene on memory retrieval after normal storage had occurred. This examination suggests that retrieval requires some of the same molecular components required for storage.

Natural Killer Cell Dysfunction and Its Role in COVID-19

When facing an acute viral infection, our immune systems need to function with finite precision to enable the elimination of the pathogen, whilst protecting our bodies from immune-related damage. In many instances however this "perfect balance" is not achieved, factors such as ageing, cancer, autoimmunity and cardiovascular disease all skew the immune response which is then further distorted by viral infection. In SARS-CoV-2, although the vast majority of COVID-19 cases are mild, as of 24 August 2020, over 800,000 people have died, many from the severe inflammatory cytokine release resulting in extreme clinical manifestations such as acute respiratory distress syndrome (ARDS) and hemophagocytic lymphohistiocytosis (HLH). Severe complications are more common in elderly patients and patients with cardiovascular diseases. Natural killer (NK) cells play a critical role in modulating the immune response and in both of these patient groups, NK cell effector functions are blunted. Preliminary studies in COVID-19 patients with severe disease suggests a reduction in NK cell number and function, resulting in decreased clearance of infected and activated cells, and unchecked elevation of tissue-damaging inflammation markers. SARS-CoV-2 infection skews the immune response towards an overwhelmingly inflammatory phenotype. Restoration of NK cell effector functions has the potential to correct the delicate immune balance required to effectively overcome SARS-CoV-2 infection.

Therapeutic implications of sex differences in asthma and atopy

Clear sex differences exist in asthma and atopy with a preponderance of boys before puberty. There is a reversal of this sex ratio during puberty with girls having more asthma and atopy throughout the reproductive years. Elucidating the reasons for the switch in the sex ratio should provide fresh insights into asthma and atopy with a real prospect of novel therapies for these troublesome diseases. The challenge is to match the epidemiology and physiology with the accumulating scientific knowledge on gender differences in immune responses. Hormonal changes have been implicated in the reversal of the sex ratio. Testosterone is an immunosuppressant and is likely to be protective, while female sex steroids are proinflammatory and will increase the susceptibility to atopy. Modified so as to be non-virilising/feminising, sex steroids could therefore play a useful part in modulating the immunological and inflammatory processes that underlie asthma and other allergic disorders, complementing the currently used glucocorticoid derived steroids.

Fifteen-Year Trends in Incidence of Cardiogenic Shock Hospitalization and In-Hospital Mortality in the United States

Background There is a lack of contemporary data on cardiogenic shock (CS) in-hospital mortality trends. Methods and Results Patients with CS admitted January 1, 2004 to December 31, 2018, were identified from the US National Inpatient Sample. We reported the crude and adjusted trends of in-hospital mortality among the overall population and selected subgroups. Among a total of 563 949 644 hospitalizations during the period from January 1, 2004, to December 30, 2018, 1 254 358 (0.2%) were attributed to CS. There has been a steady increase in hospitalizations attributed to CS from 122 per 100 000 hospitalizations in 2004 to 408 per 100 000 hospitalizations in 2018 (P_trend<0.001). This was associated with a steady decline in the adjusted trends of in-hospital mortality during the study period in the overall population (from 49% in 2004 to 37% in 2018; P_trend<0.001), among patients with acute myocardial infarction CS (from 43% in 2004 to 34% in 2018; P_trend<0.001), and among patients with non-acute myocardial infarction CS (from 52% in 2004 to 37% in 2018; P_trend<0.001). Consistent trends of reduced mortality were seen among women, men, different racial/ethnic groups, different US regions, and different hospital sizes, regardless of the hospital teaching status. Conclusions Hospitalizations attributed to CS have tripled in the period from January 2004 to December 2018. However, there has been a slow decline in CS in-hospital mortality during the studied period. Further studies are necessary to determine if the recent adoption of treatment algorithms in treating patients with CS will further impact in-hospital mortality.

Incidence and Clinical Impact of Device-Related Thrombus Following Percutaneous Left Atrial Appendage Occlusion: A Meta-Analysis

OBJECTIVES

This study sought to assess the incidence and clinical impact of device related thrombus (DRT) following precautions left atrial appendage occlusion (LAAO).

BACKGROUND

Device-related thrombus is a known complication of LAAO. However, data on the incidence of DRT and its impact on outcomes are limited.

METHODS

The authors performed a meta-analysis of randomized and observational studies to calculate the pooled incidence of DRT and the pooled odds ratio (OR) of ischemic events in patients with DRT and those without DRT.

RESULTS

In the 66 included studies; the incidence of DRT was 351/10, 153 (3.8%, range 0% to 17%, I² = 56.8). The diagnosis was made in <90, 90 to 365, and >365 days in 42%, 57%, and 1% of patients, respectively. There was no difference in DRT rates between the AMPLATZER (AMPLATZER, AGA Medical Corporation, Golden Valley, Minnesota) and WATCHMAN (WATCHMAN, Boston Scientific Corporation, Marlborough, Massachusetts) devices (3.6% vs. 3.1%, p = 0.24). In a meta-regression, age, gender, heart failure, diabetes, CHA₂DS₂-VASc score, previous stroke, and post-LAAO antithrombotic regimen did not explain the heterogeneity in the incidence of DRT. The pooled incidence of ischemic events in studies that compared outcomes of patients with and without DRT (32 studies; n = 7,689) was 13.2% (37 of 280) in patients with DRT and 3.8% (285 of 7,399) in those without DRT (OR: 5.27, 95% confidence interval [CI]: 3.66 to 7.59; p < 0.001, I² = 0). In a sensitivity analysis including randomized trials and prospective multicenter registries, the incidence of DRT was 3.7%, and DRT remained associated with higher rates of ischemic events (13.5% vs. 4.4%, OR: 4.15, 95% CI: 2.77 to 6.22; p < 0.001, I² = 0).

CONCLUSIONS

DRT after LAAO is uncommon (3.8%) but is associated with a 4- to 5-fold increase in ischemic events. Further studies are needed to understand the underlying mechanisms and the optimal surveillance and management of DRT.

Distribution of protein kinase Mzeta and the complete protein kinase C isoform family in rat brain

Protein kinase C (PKC) is a multigene family of at least ten isoforms, nine of which are expressed in brain (alpha, betaI, betaII, gamma, delta, straightepsilon, eta, zeta, iota/lambda). Our previous studies have shown that many of these PKCs participate in synaptic plasticity in the CA1 region of the hippocampus. Multiple isoforms are transiently activated in the induction phase of long-term potentiation (LTP). In contrast, a single species, zeta, is persistently activated during the maintenance phase of LTP through the formation of an independent, constitutively active catalytic domain, protein kinase Mzeta (PKMzeta). In this study, we used immunoblot and immunocytochemical techniques with isoform-specific antisera to examine the distribution of the complete family of PKC isozymes and PKMzeta in rat brain. Each form of PKC showed a widespread distribution in the brain with a distinct regional pattern of high and low levels of expression. PKMzeta, the predominant form of PKM in brain, had high levels in hippocampus, frontal and occipital cortex, striatum, and hypothalamus. In the hippocampus, each isoform was expressed in a characteristic pattern, with zeta prominent in the CA1 stratum radiatum. These results suggest that the compartmentalization of PKC isoforms in neurons may contribute to their function, with the location of PKMzeta prominent in areas notable for long-term synaptic plasticity.

Impaired mitochondrial function induced by serum from septic shock patients is attenuated by inhibition of nitric oxide synthase and poly(ADP-ribose) synthase

OBJECTIVE

The purpose of this study was to determine the role of nitric oxide and poly(ADP-ribose) synthase on impaired mitochondrial function in septic shock.

DESIGN

Human umbilical vein endothelial cells were incubated with serum from ten healthy controls, 20 patients with septic shock, and seven critically ill patients who were not septic. The experiment was repeated after pretreatment with 3-aminobenzamide, a poly(ADP-ribose) synthase inhibitor, or N(G)-methyl-L-arginine, a nonspecific nitric oxide synthase inhibitor.

MEASUREMENTS

Mitochondrial respiration was measured using a modified MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) assay.

SETTING

Research laboratory.

MAIN RESULT

Endothelial cell mitochondrial respiration was significantly depressed by septic serum and averaged 61% +/- 6% of control values (p <.05). Incubation with septic serum as compared with control serum also significantly decreased cellular adenosine triphosphate levels (6.7 +/- 1.2 nM vs. 13.5 +/- 1.9 nM, p<.01). The level of mitochondrial respiration in endothelial cells exposed to septic serum did not correlate with arterial lactate concentration but was correlated with both cardiac output (r(s) =.52, p<.05) and mixed venous oxygen saturation (r(s) =.61, p<.05). Pretreatment with N(G)-methyl-L-arginine significantly increased mitochondrial respiration in endothelial cells treated with septic serum from 63% +/- 6% of normal to 88% +/- 6% (p <.05) of normal values. Similarly, pretreatment with 3-aminobenzamide increased mitochondrial respiration in endothelial cells treated with septic serum from 64% +/- 6% to 100% +/- 4% (p <.01) of normal values. Endothelial cells incubated with serum from nonseptic critically ill patients did not demonstrate a significant decrease in mitochondrial respiration.

CONCLUSION

In vitro mitochondrial respiration was significantly depressed by septic serum. The addition of N(G)-methyl-L-arginine, a nitric oxide synthase inhibitor, and 3-aminobenzamide, a blocker of the poly(ADP-ribose) synthase pathway, significantly attenuated this suppression. These data suggest that nitric oxide and poly(ADP-ribose) synthase activation may play an important role in the inhibition of mitochondrial respiration in septic shock.

A homolog of Escherichia coli RecA protein in plastids of higher plants

Studies of chloroplast DNA variations, and several direct experimental observations, indicate the existence of recombination ability in algal and higher plant plastids. However, no studies have been done of the biochemical pathways involved. Using a part of a cyanobacterial recA gene as a probe in Southern blots, we have found homologous sequences in total DNA from Pisum sativum and Arabidopsis thaliana and in a cDNA library from Arabidopsis. A cDNA was cloned and sequenced, and its predicted amino acid sequence is 60.7% identical to that of the cyanobacterial RecA protein. This finding is consistent with our other results showing both DNA strand transfer activity and the existence of a protein of the predicted molecular mass crossreactive with antibodies to Escherichia coli RecA in the stroma of pea chloroplasts.

Vitamin D deficiency and risk of cardiovascular diseases: a narrative review

Vitamin D, a fat-soluble prohormone, has wide-ranging roles in the regulation of many physiological processes through their interactions with the vitamin D receptors (VDR). It plays a major role in bones and calcium metabolism. Vitamin D deficiency is not uncommon and it has been associated with many health-related issues, including skeletal and non-skeletal complications. The association of low vitamin D and cardiovascular diseases and risk factors has been explored in both animal and human studies. However, studies and trials on the effect of vitamin D supplementation on cardiovascular risk factors and hypertension are conflicting with inconsistent results. Therefore, large, well-powered randomized controlled trials are warranted. If successful, supplementation with easy and low-cost vitamin D can impact our health positively. Here, we summarized the evidence for the association of vitamin D, cardiovascular diseases and risk factors, including coronary artery diseases, stroke, and hypertension, and mortality, with special consideration to resistant hypertension.

Impaired natural killer cell counts and cytolytic activity in patients with severe COVID-19

The global pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-driven coronavirus disease 2019 (COVID-19) has caused unprecedented human death and has seriously threatened the global economy. Early data suggest a surge in proinflammatory cytokines in patients with severe COVID-19, which has been associated with poor outcomes. We recently postulated that the inflammatory response in patients with severe COVID-19 disease is not inhibited by natural killer (NK) cells, resulting in a "cytokine storm." Here, we assessed the NK-cell functional activity and the associated cytokines and soluble mediators in hospitalized COVID-19 patients. Significantly impaired NK-cell counts and cytolytic activity were observed in COVID-19 patients when compared with healthy controls. Also, cytokines like interleukin 12 (IL12), IL15, and IL21 that are important for NK-cell activity were not detected systematically. Serum concentrations of soluble CD25 (sCD25)/soluble IL2 receptor α (sIL2-Rα) were significantly elevated and were inversely correlated with the percentage of NK cells. Impaired NK-cell cytolytic activity together with other laboratory trends including elevated sCD25 were consistent with a hyperinflammatory state in keeping with macrophage-activation syndrome. Our findings suggest that impaired counts and cytolytic activity of NK cells are important characteristics of severe COVID-19 and can potentially facilitate strategies for immunomodulatory therapies.

An autoradiographic study of the uptake and distribution of iron by the brain of the young rat

Rats aged 15, 28, or 42 days were injected intraperitoneally with iron-59 and were sacrificed at varying intervals. Total acquisition of iron-59 by the brain, when compared to levels of iron-59 in blood sampled 48 h after injection, diminished with increasing age at injection. Cerebral levels of iron-59 in animals injected at age 15 days did not change with postinjection interval despite rapidly decreasing serum levels of iron-59. Thus, iron acquired by the brain early in postnatal development becomes sequestered in that organ. However, autoradiography of the brains of animals injected at age 15 days showed definite changes over time in the anatomic distribution of the isotope. This suggests that mechanisms may exist for the translocation of iron from one area of the brain to another.

Correlation of PVT Properties for UAE Crudes (includes associated papers 26135 and 26316 )

Summary.

Available PVT data from UAE reservoirs was used to obtain correlation equations for bubblepoint pressure and oil FVF as functions of oil specific gravity, gas gravity, solution GOR, and reservoir temperature. Error bounds of the obtained correlations are calculated and compared with other available correlations. The correlations of this study result in lower errors and should work better for UAE crudes.

Introduction

PVT data are essential in reservoir engineering calculations. It is important to obtain reservoir fluid samples to determine PvT properties. In case no fluid samples are taken, correlations can be used to estimate PVT data. This is particularly true during the early development phase where fluid properties are only available from surface flow tests. Correlations of bubblepoint pressure, formation pressure, and FVF, were published as early as 1947 by Standing, who used California reservoir samples. The bubblepoint pressure, Pb. and the oil FVF, Bob, were correlated with gas solubility, Rs gas and oil gravity, and reservoir temperature, T. The correlation was based on 22 different crude oil/natural gas mixtures and a total of 105 samples. Other correlations were made from data available in other regions. Glaso used 45 samples to obtain a correlation for North Sea oils. Sutton and Farshad reviewed empirically derived PVT properties for Gulf of Mexico crude oils, and Al-Marhoun presented PVT correlations for Middle East crudes using data from 69 bottomhole samples. All correlations cited above were concerned with crudes from different locations and presumably of different characteristics. Each study claimed that the resulting correlation could be applied to crude conditions anywhere. The particular composition of each crude and the presence of certain components that characterized them and affected their properties are well-known. The effect of crude paraffinicity, and the presence of CO2, N2, and H2S on PVT properties have been studied. Lassater reported that the predicted bubblepoint pressure decreases as the CO2 content in the crude oil increases, while Glaso reported the opposite; i.e., saturation pressures increase with increasing CO2 content. Jacobson and Glaso both noted an increase in the Saturation pressure with increasing N2 content. Saturation pressure was found to decrease in the presence of H2S. The paraffinicity and the presence of CO2, N2 and H2S are not the only factors expected to affect crude PVT properties. Other factors may include the total sulfur content and the asphaltene content. Thus, a universal correlation would be difficult to obtain and instead, correlations for local regions, where crude properties are expected to be uniform, are a reasonable alternative. In the current study, measurements on 51 bottomhole samples from UAE reservoirs and regression analysis are used to obtain bubblepoint pressure and oil FVF correlations. Bounds of errors and comparisons with previous correlations are presented.

Regression Analysis

Bubblepoint Pressure.

Standing presented the following general relation for the saturation pressure of an oil sample and solution GOR, gas and oil gravities, and formation temperature. (1)

A particular model that expresses the relationship among variables can be written as

(2)

Taking the logarithm of both sides, (3)

The unknowns in Eq. 3 are a0 through a4. Applying the known experimental data of Pb Rs, and Tin Eq. 3 allows us to solve for the five unknowns. The system can be solved for the a unknowns with . Details of the solution method are given elsewhere.

Bubblepoint FVF.

The bubblepoint oil FVF is related to solution GOR, gas and oil gravities, and formation temperature with the following general correlation: (4) For the current correlation, Eq. 5 was written in the form presented by Al-Marhoun. (5)

The constant b is determined by trial and error, with the initial value assumed to equal the reciprocal of the average temperature, or (l/ST)/n. Then, Eq. 5 becomes - (6)

which is solved in the unknowns through . A function M is defined as (7) Then, the bubblepoint FVF is derived from (8)

PVT Correlations Table 1 gives the experimental data used to develop the following correlations. Bubblepoint pressure correlation:

(9) Bubblepoint oil FVF correlation: (10) (11)

Correlation Errors The deviation of correlated bubblepoint pressure and FVF from experimentally determined values was calculated by several statistical equations given below. Percent relative error: (12)

SPEFE

P. 41⁁

Identification of human herpesvirus 8-specific cytotoxic T-cell responses

Human herpesvirus 8 (HHV-8) (or Kaposi's sarcoma-associated herpesvirus) is implicated in the etiopathogenesis of Kaposi's sarcoma (KS) and certain lymphoproliferations. The introduction of more effective therapies to treat human immunodeficiency virus infection has led to a decline in the incidence of KS and also in the resolution of KS in those already affected. This suggests that cellular immune responses including cytotoxic T lymphocytes (CTLs) could play a vital role in the control of HHV-8 infection and in KS pathogenesis. Here we elucidate HLA class I-restricted, HHV-8-specific cellular immune responses that could be important in the control of HHV-8 infection and subsequent tumor development. We show the presence of CTLs against HHV-8 latent (K12), lytic (K8.1), and highly variable (K1) proteins in infected individuals.

Marketing hand hygiene in hospitals--a case study

Hand hygiene of healthcare workers is frequently poor despite the efforts of infection control teams to promote hand decontamination as the most important method to prevent transmission of hospital-acquired infections. In this case study, we describe how principles of societal marketing were applied to improve hand hygiene. Pre-marketing analysis of strengths, weaknesses, opportunities and threats to implementation; attention to product, price, promotion and placement; and post-marketing 'customer' surveys were the essential components of the marketing strategy and its implementation. Placement of an alcohol-based gel decontaminant (Spirigel) at the bedside of every patient was widely welcomed in the hospital, and has played a major role in improving hand hygiene of healthcare workers. In the twelve months following the implementation, the decontaminant was used at least 440,000 times. The cost of purchasing the decontaminant was approximately 5000 pounds sterling. Following the introduction of Spirigel, there was a consistent reduction in the proportion of hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) in each of the quarters of 2000-2001 compared with 1999-2000. In the period 1999-2000, nearly 50% of the MRSA were hospital acquired compared with 39% in 2000-2001. Similarly, the average incidence of Clostridium difficile associated diarrhoea (CDAD) decreased in each of the quarters in 2000-2001 following the introduction of Spirigel. During this period, there was an average incidence of 9.5 cases of CDAD/1000 admissions compared with 11.5 cases of CDAD/1000 admissions in 1999-2000. This represents a 17.4% reduction in the incidence of CDAD. However, this reduction was not statistically significant (P=0.2). Our case study demonstrates that principles of societal marketing methods can be used effectively to promote and sustain hand hygiene in hospitals. Improvement in hand hygiene will lead to considerable reduction in hospital-acquired infections.

Breast implant illness: scientific evidence of its existence

INTRODUCTION

More than one million breast augmentation procedures using silicone breast implants (SBI) have been performed worldwide. Adverse events of SBI include local complications such as pain, swelling, redness, infections, capsular contracture, implant rupture and gel-bleed. Furthermore, patients experience systemic symptoms such as chronic fatigue, arthralgias, myalgias, pyrexia, sicca, and cognitive dysfunction. These symptoms received different names such as autoimmune/inflammatory syndrome induced by adjuvants (ASIA) due to silicone incompatibility syndrome and breast implant illness (BII). Because of chronic immune activation, BII/ASIA, allergies, autoimmune diseases, immune deficiencies and finally lymphomas may develop in SBI patients.

AREAS COVERED

Causality for SBI-related BII/ASIA is reviewed. To address the role of silicone implants in promoting causality, we utilized the Bradford-Hill criteria, with results highlighted in this article.

EXPERT OPINION

We conclude that there is a causal association between SBIs and BII/ASIA. Using data derived from patients with BII/ASIA and from other medically implanted devices, there appears to be clear pathogenic relationship between SBI and BII/ASIA. Breast implants cause characteristic systemic reactions in certain women, leading to symptoms of sufficient severity to warrant device removal. The morbidity suffered is variable. SBI removal resolves the symptoms in most women and removal is the most effective treatment.

Erythroid precursors and progenitors suppress adaptive immunity and get invaded by SARS-CoV-2

SARS-CoV-2 infection is associated with lower blood oxygen levels, even in patients without hypoxia requiring hospitalization. This discordance illustrates the need for a more unifying explanation as to whether SARS-CoV-2 directly or indirectly affects erythropoiesis. Here, we show significantly enriched CD71⁺ erythroid precursors/progenitors in the blood circulation of COVID-19 patients. We found that these cells have distinctive immunosuppressive properties. In agreement, we observed a strong negative correlation between the frequency of these cells with T and B cell proportions in COVID-19 patients. The expansion of these CD71⁺ erythroid precursors/progenitors was negatively correlated with the hemoglobin levels. A subpopulation of abundant erythroid cells, CD45⁺ CD71⁺ cells, co-express ACE2, TMPRSS2, CD147, and CD26, and these can be infected with SARS-CoV-2. In turn, pre-treatment of erythroid cells with dexamethasone significantly diminished ACE2/TMPRSS2 expression and subsequently reduced their infectivity with SARS-CoV-2. This provides a novel insight into the impact of SARS-CoV-2 on erythropoiesis and hypoxia seen in COVID-19 patients.

Intra-articular morphine and clonidine produce comparable analgesia but the combination is not more effective

Both intra-articular morphine and clonidine produce analgesia. This study was designed to compare the analgesic effects of the two drugs, used separately and in combination. We studied 90 patients undergoing arthroscopy of the knee under general anaesthesia. Patients were allocated randomly to receive 20 ml of intra-articular isotonic saline solution containing morphine 2 mg, clonidine 150 micrograms or both. Pain was assessed on an visual analogue scale after operation and time for rescue medication was measured. There was no difference in VAS scores between the three groups and the time for rescue analgesic was comparable. We conclude that intra-articular morphine and clonidine have comparable analgesic effects in the doses used. The combination of both drugs did not seem to increase analgesia.

Dexamethasone-associated toxicity during induction chemotherapy for childhood acute lymphoblastic leukemia is augmented by concurrent use of daunomycin

BACKGROUND

The goals of the current study were to examine the incidence and severity of toxicity resulting from dexamethasone and prednisone during induction therapy for children with precursor B-cell acute lymphoblastic leukemia (ALL) and to determine whether the addition of daunomycin affected toxicity.

METHODS

Medical records of patients with precursor B-cell ALL from January 1996 through June 2000 were reviewed retrospectively for toxicity during the 4-week induction phase and the 2 weeks after the induction phase.

RESULTS

One hundred seventy-six patients age < 14 years were diagnosed with precursor B-cell ALL from January 1996 through June 2000. Of the 156 evaluable patients, 106 were treated with prednisone and 50 with dexamethasone. Fifty-two patients received steroids, L-asparaginase, and vincristine, whereas 104 high-risk patients received daunomycin in addition to these 3 agents. The incidence of gastritis was significantly higher among patients receiving dexamethasone (P = 0.01); incidence rates of hyperglycemia, hypertension, and myopathy were similar for all treatment groups. Dexamethasone led to more weight gain than did prednisone (+11.9% vs. +5.4%; P = 0.002). Serious infections were observed in 27 (25.5%) and 18 (36%) patients receiving prednisone and dexamethasone, respectively (P < or = 0.2). Five patients, four of whom received prednisone and one of whom received dexamethasone, died of infection. The addition of daunomycin to treatment regimens increased overall toxicity (P < 0.01). When daunomycin was included in treatment regimens, toxicity was greater among patients receiving dexamethasone; in contrast, when daunomycin was not included, toxicity was equal for both treatment groups. Regardless of daunomycin use, there was no difference in the incidence of serious infection between the two groups. ALL treatment was not compromised by steroid-related toxicity in either group.

CONCLUSIONS

The addition of daunomycin led to a much larger increase in dexamethasone-related toxicity compared with the increase in prednisone-related toxicity. Although the use of daunomycin enhanced dexamethasone-related toxicity, this enhancement did not result in a higher mortality rate or the alteration of planned ALL therapy.

Obesity modulate serum hepcidin and treatment outcome of iron deficiency anemia in children: a case control study

Background

Recently, hepcidin expression in adipose tissue has been described and shown to be increased in patients with severe obesity. We tried to assess the effect of obesity on hepcidin serum levels and treatment outcome of iron deficiency anemia in children.

Methods

This was a case control study included 70 children with iron deficiency anemia "IDA" (35 obese and 35 non-obese) and 30 healthy non-obese children with comparable age and sex(control group). Parameters of iron status (Serum iron, ferritin, transferrin, total iron binding capacity and transferrin saturation) and serum hepcidin levels were assessed initially and after 3 months of oral iron therapy for IDA.

Results

Compared to the control group, serum hepcidin was significantly lower in non-obese children with IDA(p < 0.01) and significantly higher in obese children with IDA (p < 0.01). Hepcidin increased significantly in non-obese children with IDA after 3 months of iron therapy (P < 0.01). On the other hand, obese children showed non-significant change in hepcidin level after iron therapy (p > 0.05). Although hepcidin showed significant positive correlations with Hb, serum iron and transferrin saturation in non-obese children with IDA, it showed significant negative correlations with Hb, serum iron and transferrin saturation in obese children with IDA (P < 0.05).

Conclusions

Obesity increased hepcidin levels and was associated with diminished response to oral iron therapy in childhood iron deficiency anemia.

Comparison of oral and subcutaneous routes of cocaine administration on behavior, plasma drug concentration and toxicity in female rats

Oral and subcutaneous routes of administration of cocaine HCl were investigated in female Wistar rats for food and water consumption, locomotor activity, stereotypic behaviors, plasma drug concentrations and injection site pathology. Animals received either 40 or 80 mg/kg/day by gastric intubation (PO-40 and PO-80 respectively) or 20 or 40 mg/kg/day subcutaneously (SC-20 and SC-40). All groups received the drug or the vehicle for 16 consecutive days. Locomotor activity and stereotypy were evaluated on Days 1, 5, 10, and 15. Plasma drug concentrations and injection site pathology were determined on Day 16. Subcutaneous administration was associated with a sensitization to the effects of cocaine on locomotion and stereotypy, higher blood levels than oral administration at the same dose, and severe dermal lesions. However, there were no differences in any measure between the SC-20 and SC-40 groups. Oral cocaine was also associated with behavioral sensitization. However, unlike the SC route, oral cocaine was characterized by dose-related increases in locomotion and stereotypy in the absence of gastrointestinal pathology. Inasmuch as oral administration resulted in dose-response relationships and low toxicity while subcutaneous administration did not, these factors should be considered in future studies utilizing chronic cocaine administration.

The human immunodeficiency virus-1 Tat protein increases cell proliferation, alters sensitivity to zinc chelator-induced apoptosis, and changes Sp1 DNA binding in HeLa cells

The HIV-1 transcriptional regulatory protein Tat is a pleiotropic factor that represses expression of the human Mn-superoxide dismutase. Tat increases oxidative stress, as shown by decreased glutathione and NADPH levels. These redox changes enhance proliferation and apoptosis and alter the activity of zinc thiolate-containing proteins such as Sp1. Cells stably producing the Tat protein have an increased proliferation rate, which can be inhibited by pretreatment with the antioxidant mercaptopropionylglycine. Conversely, cells exposed to low concentrations of the oxidant paraquat are stimulated to divide. Intermediate and higher paraquat levels result in increased apoptosis or necrosis, respectively, suggesting that the physiological end point depends on the dose of oxidant used. Furthermore, treatment with the zinc chelator (N,N,N', N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) sensitizes HeLa-tat cells to apoptosis. In these cells, binding of the zinc-containing factor Sp1 to its DNA sequence is higher than in parental cells. Normal DNA binding is partially restored by pretreatment with a compound that mimics superoxide dismutase activity. Interestingly, Sp1-DNA interactions decrease more rapidly in the HeLa-tat cells after TPEN treatment. HeLa cell extracts incubated in the presence of purified Tat protein have increased Sp1 binding, consistent with the results observed in Tat-transfected cells. These results suggest that the Tat protein, via direct or indirect mechanisms, increases proliferation, sensitizes cells to apoptosis, and changes the conformation of Sp1, affecting its ability to bind to its cognate DNA sequence and to retain its zinc.