Discriminatory accuracy of the SOFA score for determining clinical decompensation in patients presenting with COVID-19

Introduction

While the global dissemination of vaccines targeting the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a decline in the incidence of infections, the case fatality rates have remained relative stable. A major objective of managing hospitalized patients with documented or suspected COVID-19 infection is the rapid identification of features associated with severe illness using readily available laboratory tests and clinical tools. The sequential organ failure assessment (SOFA) score is a validated tool to facilitate the identification of patients at risk of dying from sepsis.

Purpose

The aim of this study was to assess the discriminatory accuracy of the SOFA score in predicting clinical decompensation in patients hospitalized with COVID-19 infection.

Methods

We conducted a retrospective analysis at a three-hospital health system, comprised of one tertiary and two community hospitals, located in the Chicago metropolitan area. All patients had positive SARS-CoV-2 testing and were hospitalized for COVID-19 infection. The primary outcome was clinical decompensation, defined as the composite endpoint of death, ICU admission, or need for intubation. We utilized the most abnormal laboratory values observed during the admission to calculate the SOFA score. Receiver Operating Curves (ROC) were then constructed to determine the sensitivity and specificity of SOFA scores.

Results

Between March 1st and May 31st 2020, 1029 patients were included in our analysis with 367 patients meeting the study endpoint. The median SOFA score was 2.0 IQR (Q1, Q3 1,4) for the entire cohort. Patients who had in-hospital mortality had a median SOFA score of 4.0 (Q1,Q3 3,7). In patients that met the primary composite endpoint, the median SOFA score was 3.0, IQR (Q1, Q3 2,6). The ROC was 0.776 (95% CI 0.746–0.806, p<0.01).

Conclusion

The SOFA score demonstrates strong discriminatory accuracy for prediction of clinical decompensation in patients presenting with COVID-19 at our urban hospital system.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Loyola University Medical Center

Predictors of clinical decompensation in patients presenting with COVID-19 in an urban hospital health system

Introduction

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a pandemic which has infected more than 128 million people and led to over 2.8 million deaths worldwide. Although the introduction of efficacious vaccines has led to overall declines in the incidence of SARS-CoV-2 infection, there has been a recent increase in infections once more due to the appearance of mutant strains with higher virulence. It therefore remains vital to identify predictors of poor outcomes in this patient population.

Purpose

The objective of our study was to identify predictors of prolonged hospitalization, intensive care unit (ICU) admission, intubation, and death in patients infected with SARS-CoV-2.

Methods

We conducted a retrospective analysis of all patients hospitalized with SARS-CoV-2 at our health system that includes one tertiary care center and two community hospitals located in the Chicago metropolitan area. The main outcome was a composite endpoint of hospitalization >28 days, ICU admission, intubation, and death.

Explanatory variables associated with the primary outcome in the bivariate analysis (p<0.05) were included in the multivariable logistic regression model. Statistical analysis was performed using IBM SPSS 25.0.

Results

Between March 1, 2020 and May 31, 2020, 1029 patients hospitalized with SARS-CoV-2 were included in our analysis. Of these patients, 379 met the composite endpoint. Baseline demographics are described in Table 1. Of note, our cohort consisted of a predominantly minority patient population including 47% Hispanic, 17% African American, 16% Caucasian, and 16% other.

In bivariate analysis, age, hypertension, tobacco and alcohol abuse, obesity, coronary artery disease, arrhythmias, valvular heart disease, dyslipidemia, hypertension, stroke, diabetes, documented thrombosis, troponin, CRP, ESR, ferritin, LDH, BNP, D-dimer >5x the upper limit of normal, lactate, and right ventricular outflow tract velocity time integral <9.5 were significant.

After multivariable adjustment, explanatory variables associated with the composite endpoint included troponin (OR 2.36; 95% CI 1.08–5.17, p 0.03), D-dimer (OR 1.5; 95% CI 1.23–1.98, p<0.01, lactate (OR 1.58; 95% CI 1.28–1.95, p<0.01), and documented thrombosis (OR 3.56; 95% CI 1.30–8.70, p<.05). Race was not a predictor of poor outcomes in the bivariate or multivariate analysis (Table 2).

Conclusions

In a large urban cohort with a predominantly minority population, we identified several clinical predictors of poor outcomes. Of note, race was not a predictor of the primary endpoint in this study. While recent literature has demonstrated worse outcomes among racial minorities infected with SARS-CoV-2, our data suggests these variations are related to social determinants of health rather than biologic causes.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Loyola University Medical Center

Mesalazine granules 1.5 g once-daily maintain remission in patients with ulcerative colitis who switch from other 5-ASA formulations: a pooled analysis from two randomised controlled trials

BACKGROUND

Mesalazine (mesalamine) granules (MG) were shown to be effective for the maintenance of remission of ulcerative colitis (UC) in two double-blind placebo-controlled trials.

AIM

To evaluate the efficacy of once-daily MG for maintenance of remission in patients with UC who switched from other 5-aminosalicylic acid (5-ASA) formulations.

METHODS

Data from two independent multicenter, randomised, double-blind, placebo-controlled, 6-month trials evaluating patients with UC in remission were combined for analysis of a subpopulation of patients who switched from other 5-ASA formulations to MG 1.5 g or placebo upon randomisation. The primary endpoint was the percentage of patients who remained relapse-free at Month 6 or end of treatment. Relapse was defined as a Sutherland Disease Activity Index (SDAI) rectal bleeding score ≥1 and mucosal appearance score ≥2, a UC flare or medication used to treat a UC flare.

RESULTS

Of the 487 patients who received 5-ASA maintenance therapy at enrolment, 322 were in the MG group and 165 were in the placebo group. The percentage of patients who remained relapse-free (based on Sutherland Disease Activity Index scores) after 6 months was significantly higher with MG than placebo (78.3% vs. 58.8%, P < 0.001). Rectal bleeding, stool frequency and the physician's rating of disease activity remained unchanged after 6 months in a higher percentage of patients using MG compared with those on placebo (P < 0.004 for each endpoint).

CONCLUSION

Mesalazine granules 1.5 g once-daily is effective for maintenance of remission in UC patients who switch from other 5-ASA formulations. ClinicalTrials.gov identifiers NCT00744016, NCT00767728.

Randomised clinical trial: rifaximin improves health-related quality of life in cirrhotic patients with hepatic encephalopathy - a double-blind placebo-controlled study

BACKGROUND

Hepatic encephalopathy (HE) is a brain disorder that often results from cirrhosis due to viral hepatitis, metabolic and alcohol-related liver disease, and is characterised by cognitive, psychiatric and motor impairments. Recurrent bouts of overt HE negatively impact daily functioning and quality of life.

AIM

To evaluate the effect of rifaximin on health-related quality of life (HRQL) in cirrhotic patients with HE.

METHODS

Patients with cirrhosis in remission from HE (Conn score = 0 or 1) and a documented history of recurrent HE episodes (≥2 within 6 months of screening) were randomised to rifaximin 550 mg twice daily (N = 101) or placebo (N = 118) for 6 months. Concomitant lactulose was permitted during the study. The Chronic Liver Disease Questionnaire (CLDQ) was administered every 4 weeks, and time for occurrence of HE breakthrough was recorded. A longitudinal analysis using time-weighted averages of the CLDQ scores normalised by days on study therapy was used to evaluate the effect of treatment on HRQL, and between HE outcomes (HE recurrence, yes/no) irrespective of treatment.

RESULTS

The time-weighted averages of the overall CLDQ score and each domain score were significantly higher in the rifaximin group vs. placebo (P-values ranged from 0.0087 to 0.0436); and were significantly lower in patients who experienced HE breakthrough compared to those who remained in remission (P-values were <0.0001).

CONCLUSION

Rifaximin significantly improved HRQL in patients with cirrhosis and recurrent hepatic encephalopathy. A lower HRQL may predict recurrence of hepatic encephalopathy.

Molecular basis of the anti-cancer effects of genistein isoflavone in LNCaP prostate cancer cells

Background: Prostate cancer is the most common form of non-skin cancer within the United States and the second leading cause of cancer deaths. Survival rates for the advanced disease remain relatively low, and conventional treatments may be accompanied by significant side effects. As a result, current research is aimed at alternative or adjuvant treatments that will target components of the signal transduction, cell-cycle and apoptosis pathways, to induce cell death with little or no toxic side effects to the patient. In this study, we investigated the effect of genistein isoflavone, a soy derivative, on expression levels of genes involved in these pathways. The mechanism of genistein-induced cell death was also investigated. The chemosensitivity of the LNCaP prostate cancer cells to genistein was investigated using ATP and MTS assays, and a caspase binding assay was used to determine apoptosis induction. Several molecular targets were determined using cDNA microarray and RT-PCR analysis.Results: The overall data revealed that genistein induces cell death in a time- and dose-dependent manner, and regulates expression levels of several genes involved in carcinogenesis and immunity. Several cell-cycle genes were down-regulated, including the mitotic kinesins, cyclins and cyclin-dependent kinases. Various members of the Bcl-2 family of apoptotic proteins were also affected. The DefB1 and the HLA membrane receptor genes involved in immunogenicity were also up-regulated. Conclusion: The results indicate that genistein inhibits growth of the hormone-dependent prostate cancer cells, LNCaP, via apoptosis induction through regulation of some of the genes involved in carcinogenesis of many tumors, and immunogenicity. This study augments the potential phytotherapeutic and immunotherapeutic significance of genistein isoflavone. Key words: Genistein isoflavone, prostate cancer, expression of genes, phytotherapeutic adjuvant, immunotherapy and chemotherapy

Clinical trial: once-daily mesalamine granules for maintenance of remission of ulcerative colitis - a 6-month placebo-controlled trial

BACKGROUND

Ulcerative colitis (UC) is a chronic relapsing and remitting idiopathic inflammatory bowel disorder.

AIM

To evaluate once-daily mesalamine (mesalazine) granules (MG) for maintenance of remission of UC.

METHODS

Randomized, double-blind, placebo-controlled trial of patients (n=209 MG, n=96 placebo) with UC in remission [revised Sutherland Disease Activity Index (SDAI) rectal bleeding=0, mucosal appearance <2] who took MG 1.5 g or placebo once-daily for up to 6 months. Primary efficacy endpoint: the percentage of patients who remained relapse-free at month 6/end of treatment. Relapse was defined as SDAI rectal bleeding score ≥1 and a mucosal appearance score ≥2, a UC flare, or initiation of medication to treat a UC flare.

RESULTS

The percentage of relapse-free patients at month 6/end of treatment was higher with MG than placebo (78.9% vs. 58.3%, P < 0.001) in the intent-to-treat analysis. Significant differences (P ≤ 0.025) favouring MG were observed for most secondary endpoints including improvement in rectal bleeding, physician's disease activity rating, stool frequency, the SDAI at month 6/end of treatment, patients classified as a treatment success and relapse-free duration. The incidence of adverse events was similar between groups.

CONCLUSIONS

Once-daily mesalamine (mesalazine) was effective in maintaining remission of UC for 6 months.

Influence of genistein isoflavone on matrix metalloproteinase-2 expression in prostate cancer cells

We investigated the expression of matrix metalloproteinase (MMP)-2 in human LNCaP and PC3 prostate cancer cell lines in response to genistein exposure. Initially we studied the phytosensitivity of the cells to genistein using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay to determine percentage cell viability/inhibition and the terminal deoxynucleotidyl transferase-mediated fluorescein-dUTP nick end-labeling apoptosis assay to assess the type of cell death. The results revealed that genistein inhibited growth and proliferation in both PC3 (hormone-dependent) and LNCaP (hormone-independent) prostate cancer cell lines, that there was no significant difference in sensitivity to genistein between PC3 and LNCaP cells, and that the effect of genistein on the cells was dose- and time-dependent. The results also revealed that inhibition of cell growth in both PC3 and LNCaP cells was predominantly due to apoptotic cell death. These results were consistent with data in previous studies. This was followed by determination of the MMP-2 profile in response to genistein treatment. The results indicated a significant dose- and time-dependent inhibition of MMP-2 expression levels in both cells, with a highly significant negative correlation between MMP-2 levels and concentration of genistein. This is of phytotherapeutic significance in view of the pivotal role of MMP-2 expression in the pathogenesis of prostate cancer. Increasing expression of MMPs has been identified in many human cancers, including prostate cancer. Our findings indicate that genistein could be a potent therapeutic inhibitor of MMP-2 in line with current concepts of targeted treatment.

CytoregR inhibits growth and proliferation of human adenocarcinoma cells via induction of apoptosis

BACKGROUND

Cancer is one of the devastating neovascular diseases that incapacitate so many people the world over. Recent reports from the National Cancer Institute indicate some significant gain therapy and cancer management as seen in the increase in the 5-year survival rate over the past two decades. Although near-perfect cure rate have been reported in the early-stage disease, these data reveal high recurrence rate and serious side effects including second malignancies and fatalities. Most of the currently used anticancer agents are only effective against proliferating cancer cells. Thus attention has been focused on potential anti-cancer agents capable of killing cancer cells independent of the cell cycle state, to ensure effective elimination of most cancer cells. The objective of this study was to test the chemosensitivity and potential mechanism of action of a novel cancer drug, CytoregR, in a panel of human cancer cells.

METHODS

the study was performed using a series of bioassays including Trypan blue exclusion, MTS Growth inhibition, LDH-cytotoxicity, TUNEL-Terminal DNA fragmentation Apoptosis Assay, and the Caspase protease CPP32 activity assays.

RESULTS

CytoregR induced significant dose- and time-dependent inhibition of growth in all the cells; with significant differences in chemosensitivity (P < 0.05) between the target cells becoming more apparent at 48 hr exposure. CytoregR showed no significant effect on normal cells relative to the tumor cells. Growth inhibition in all the cells was due to induction of apoptosis at lower concentrations of cytoregR (> 1:300). CytoregR-induced caspase protease-3 (CPP32) activation significantly and positively correlated with apoptosis induction and growth inhibition; thus implicating CPP32 as the principal death pathway in cytoregR-induced apoptosis.

CONCLUSION

CytoregR exerted a dose-and time-dependent growth inhibitory effect in all the target cells through induction of apoptosis via the CPP32 death pathway, independent of hormonal sensitivity of the cells. The present data indicate that not only could CPP32 provide a potential target for regulation of cytoregR-induced apoptosis but also that cytoregR could play a significant role in chemotherapeutic regimen in many human malignant tumors.

The selective dopamine D4 receptor antagonist, PNU-101387G, prevents stress-induced cognitive deficits in monkeys

Stress exposure impairs the cognitive functioning of the prefrontal cortex (PFC). Previous research has examined the dopamine (DA) D1 receptor mechanisms underlying this response. The current study performed a preliminary examination of the role of D4 receptor mechanisms by determining whether the selective D4 receptor antagonist, PNU-101387G, could prevent stress-induced working memory deficits in monkeys. Animals were tested on the delayed response task following treatment with PNU-101387G (0 or 0.1-0.8 mg/kg, 60-min pretreatment), and the pharmacological stressor, FG7142 (0 or 0.2 mg/kg, 30-min pretreatment). FG7142 significantly impaired delayed response performance relative to vehicle; PNU-101387G pretreatment produced a dose-related reversal of the FG7142 response. PNU-101387G had no significant effects on its own, but there were trends toward improvement at low doses and impairment at higher doses. Further studies in a larger number of animals appear warranted. These preliminary findings suggest that D4 receptor mechanisms contribute to stress-induced cognitive dysfunction.

Nitrosation and oxidation in the regulation of gene expression

A growing body of evidence suggests that the cellular response to oxidative and nitrosative stress is primarily regulated at the level of transcription. Posttranslational modification of transcription factors may provide a mechanism by which cells sense these redox changes. In bacteria, for example, OxyR senses redox-related changes via oxidation or nitrosylation of a free thiol in the DNA binding region. This mode of regulation may serve as a paradigm for redox-sensing by eukaryotic transcription factors as most-including NF-kappaB, AP-1, and p53-contain reactive thiols in their DNA binding regions, the modification of which alters binding in vitro. Several of these transcription factors have been found to be sensitive to both reactive oxygen species and nitric oxide-related species in vivo. It remains entirely unclear, however, if oxidation or nitrosylation of eukaryotic transcription factors is an important mode of regulation, or whether transcriptional activating pathways are principally controlled at other redox-sensitive levels.-Marshall, H. E., Merchant, K., Stamler, J. S. Nitrosation and oxidation in the regulation of gene expression.

DNA length and concentration dependencies of anisotropic phase transitions of DNA solutions

Critical concentrations for the isotropic to cholesteric phase transitions of double-stranded DNA fragments in simple buffered saline (0.1 M NaCl) solutions were determined as a function of DNA contour length ranging from approximately 50 nm to 2700 nm, by solid-state 31P NMR spectroscopy and polarized light microscopy. As expected for semirigid chains, the critical concentrations decrease sharply with increasing DNA length near the persistence length in the range from 50 to 110 nm, and approach a plateau when the contour length exceeds 190 nm. The biphasic region is substantially wider than observed for xanthan, another semirigid polyelectrolyte approximately twice as stiff as DNA, primarily because of low critical concentrations for first appearance of the anisotropic phase, C(i)*, in DNA samples > or =110 nm (320 base pairs) long. The limiting C(i)* for DNA > or =490 nm long is exceptionally low (only 13 mg/ml) and is substantially lower than the C(i)* of approximately 40 mg/ml reported for the stiffer xanthan polyelectrolyte. The much higher values of the critical concentrations, C(a)*, for the disappearance of the isotropic DNA phase (> or =67 mg/ml) are modestly higher than those observed for xanthan and are predicted reasonably well by a theory that has been applied to other semirigid polymers, if a DNA persistence length in the consensus range of 50-100 nm is assumed. By contrast, the broad biphasic region and low C(i)* values of DNA fragments > or =190 nm long could only be reconciled with theory by assuming persistence lengths of 200-400 nm. The latter discrepancies are presumed to reflect some combination of deficiencies in current theory as applied to chiral, strong polyelectrolytes such as DNA, and sequence-dependent variations in DNA properties such as flexibility, curvature, or interaction potential. The propensity of DNA to spontaneously self-order at low concentrations well in the physiological range may have biological significance.

Deamination of single-stranded DNA cytosine residues in aerobic nitric oxide solution at micromolar total NO exposures

Deamination of cytosine to uracil is a potential source of mutations in DNA. Here we examine the deaminating ability of aerobic nitric oxide (NO) toward single-stranded DNA at very low (micromolar and below) total exposures, using a sensitive genetic method that allows us to study a single deamination event at a specific site in a 7200-nucleotide DNA molecule within a pool of ca. 100,000 other identical DNA molecules. We incubated gapped C141 M13mp2 DNA with the NO-generating compound, Et2N[N(O)NO]Na (DEA/NO), in aerobic buffer for 16 h to ensure complete autoxidation at pH 7.4 and 37 degrees C. After ultrafiltration to remove small molecules, the DNA was transformed into isogenic Escherichia coli cultures that were either deficient (NR9404, ung-) or proficient (MC1061, ung+) in uracil-DNA glycosylase activity. The gapped DNA was constructed such that the target (CCC) codon was contained in a short single-stranded segment of otherwise double-stranded circular DNA, and the incubation was performed in a closed system to prevent loss of NO to the atmosphere before the reaction was complete. An increase in the reversion frequency in the ung- strain was noted between 0 and 1 microM DEA/NO, and the reversion frequency leveled out between 3 and 30 microM. However, 30 microM "spent" DEA/NO (i.e., that which was similarly incubated for 4 h to complete the autoxidation of NO before the DNA was added) did not increase reversion frequency relative to control. Nearly all (42/43) of the mutations identified after 1 microM DEA/NO treatment were C-->T transitions, and reversion frequency in the isogenic ung+ strain was lower than in the ung- strain. The data are consistent with the hypothesis that total NO exposures in the mumol/L range can lead to C-->T mutations via a mechanism most probably involving deamination of DNA cytosine residues.

Tachykinin NK1 receptor antagonists act centrally to inhibit emesis induced by the chemotherapeutic agent cisplatin in ferrets

These studies have compared the pharmacological profile of two non-peptide human type neurokinin1 (hNK1) receptor selective antagonists, L-741,671 and a quaternised compound L-743,310. In radioligand binding studies L-741,671 and L-743,310 had high affinity for ferret and cloned hNK1 receptors [Ki (nM) ferret 0.7 and 0.1; human 0.03 and 0.06, respectively] but low affinity for rodent NK1 receptors [Ki (nM) 64 and 17, respectively] suggesting that ferret receptors have hNK1-like binding pharmacology. Studies in vivo showed that L-741,671 and L-743,310 had equivalent functional activity in the periphery (ID50s of 1.6 and 2 micrograms/kg i.v., respectively) as measured by inhibition of plasma protein extravasation evoked in the oesophagus of guinea pigs by resiniferatoxin (7 nmol/kg i.v.). Using an in situ brain perfusion technique in anaesthetised rats, L-741,671 was shown to be much more brain penetrant than the quaternary compound L-743,310 which had an entry rate similar to the poorly brain penetrant plasma marker inulin. These compounds thus provided an opportunity to compare the anti-emetic effects of equi-active hNK1 receptor antagonists with and without brain penetration to central NK1 receptor sites. When tested against cisplatin-induced emesis in ferrets, L-741,671 (0.3, 1 and 3 mg/kg i.v.) produced marked dose-dependent inhibition of retching and vomiting but L-743,310 was inactive at 3 and 10 micrograms/kg i.v. In contrast, direct central injection of L-741,671 and L-743,310 (30 micrograms) into the vicinity of the nucleus tractus solitarius or L-743,310 (200 micrograms) intracisternally was shown to inhibit retching and vomiting induced by i.v. cisplatin. L-741,671 and L-743,310 had equivalent functional activity, at the same dose, against cisplatin-induced emesis when injected centrally. These observations indicated that had L-743,310 penetrated into the brain after systemic administration it would have been active in the cisplatin-induced emesis assay and so show that brain penetration is essential for the anti-emetic action of systemically administered NK1 receptor antagonists.

The role of NMDA receptor systems in neuropeptide responses to stimulants of abuse

High doses of stimulants of abuse, such as methamphetamine and cocaine, cause significant increases in the content of neurotension- and dynorphin-like immunoreactivity in the striatum and nucleus accumbens (approximately 200-600% of control) in the rat. These changes in neuropeptide content are caused by stimulation of dopamine D1 receptors and prevented by the glutamate NMDA receptor antagonist, MK 801. Stimulation of the NMDA receptor with N-methyl-D-aspartate results in increases in the neuropeptide levels like that caused by methamphetamine and cocaine. These findings demonstrate that stimulants of abuse profoundly influence neurotensin and dynorphin pathways associated with extrapyramidal and limbic structures by an interaction of activated dopamine D1 and glutamate NMDA receptors.

Responses of Limbic and Extrapyramidal Neurotensin Systems to Stimulants of Abuse

In summary, we have observed that drugs of abuse, which can cause schizophrenia-like paranoia, alter striatal and accumbens NT systems in a similar, dramatic fashion. The NT responses to these drugs, in particular METH, are mediated by activation of DA D1 receptors. We have observed that NMDA-type glutamate receptors are essential for the D1-NT interaction. NMDA receptors are selective, since they do not contribute to the antagonistic effects of DA D2 receptors on NT activity. This observation suggests that NT responses to D1 and D2 regulation are mediated through separate and distinct mechanisms. Finally, we found that the presence of METH dramatically reduces striatal NT release, which most likely leads to NT accumulation in nerve terminals and the observed increase in NT tissue level. The blockade of NT release by a psychotogenic drug, such as METH, is consistent with the hypothesis that NT has antipsychotic activity and a decrease in its release may contribute to some forms of schizophrenia similar to that caused by intense use of the stimulants of abuse.

The influence of reducing agent and 1,10-phenanthroline concentration on DNA cleavage by phenanthroline + copper

Copper in the presence of excess 1,10-phenanthroline, a reducing agent, and molecular oxygen causes cleavage of DNA with a preference for T-3',5'-A-steps, particularly in TAT triplets. The active molecular species is commonly thought to be the bis-(1,10-phenanthroline)Cu(I) complex, (Phen)2Cu(I), regardless of the reducing agent type. We have found that (Phen)2Cu(I) is not the predominant copper complex when 3-mercaptopropionic acid (MPA) or 2-mercaptoethanol are used as the reducing agents, but (Phen)2Cu(I) predominates when ascorbate is used as the reducing agent. Substitution of ascorbate for thiol significantly enhances the rate of DNA cleavage by 1,10-phenanthroline + copper, without altering the sequence selectivity. We show that (Phen)2Cu(I) is the complex responsible for DNA cleavage, regardless of reducing agent, and that 1,10-phenanthroline and MPA compete for copper coordination sites. DNA cleavage in the presence of ascorbate also occurs under conditions where the mono-(1,10-phenanthroline)Cu(I) complex predominates (1:1 phenanthroline:copper ratio), but preferential cleavage was observed at a CCGG sequence and not at TAT sequences. The second phenanthroline ring of the (Phen)2Cu(I) complex appears essential for determining the T-3',5'-A sequence preferences of phenanthroline + copper when phenanthroline is in excess.

Tetrahydropyridyloxadiazoles: semirigid muscarinic ligands

Recent studies have described novel azabicycle-based muscarinic agonists which readily penetrate into the central nervous system and are capable of displaying high efficacy at cortical sites. The current paper describes the synthesis and biochemical assessment of semirigid muscarinic ligands which were used to map the requirements of the cortical muscarinic receptor and to study the degree of conformational flexibility required to cause receptor activation. Analogues 6 and 9 provide high-efficacy muscarinic agonists at cortical sites; however, C-alkylation on the tetrahydropyridine ring resulted in more rigid analogues and showed lower predicted efficacy. Molecular mechanics calculations indicated a preference for the E rotameric form. This conformation was also observed in the X-ray crystal structure of ethenyloxadiazole 12. The new compounds were tested in a biochemical assay designed to measure receptor affinity and to predict cortical efficacy.

Consequences for maternal nutrition of reproductive stress across consecutive pregnancies

Frequent cycles of reproduction increase the risk that lactation will overlap with pregnancy and shorten the duration of the recuperative interval (nonpregnant and nonlactating portion) within the reproductive cycle, thereby increasing the risk of maternal nutritional depletion. Nutritional responses to these stresses have been demonstrated by contrasting groups of women with different experiences; however, these relationships may be spurious and the result of third factors. In this study, responses to changing stress over consecutive pregnancies were studied and contrasted within individual Guatemalan women; biases caused by factors constant to women were eliminated. Stress was assessed by examining responses in maternal supplement intake, maternal fat stores, and birth weight. Overlap and short recuperative intervals were found to be stressful (in that order) for mothers as shown by increased supplement intake and reduced fat stores. Birth weight in term gestations was not affected, indicating that fetal growth is being protected at the cost of maternal nutritional status.

Maternal and fetal responses to the stresses of lactation concurrent with pregnancy and of short recuperative intervals

In many regions of the world, women breastfeed one child while pregnant with the next. Among rural Guatemalan women participating in a nutrition-supplementation trial, lactation overlapped with pregnancy in 253 of 504 (50.2%) of the pregnancies. For cases where overlap occurred, 41.4% continued to breast-feed into the second trimester and 3.2%, in the third trimester. The maternal and fetal responses to the energetic stresses of overlap and of the duration of the recuperative (nonpregnant, nonlactating) interval were assessed. Overlap resulted in increased supplement intake. Short recuperative periods (less than 6 mo) resulted in increased supplement intake and reduced maternal fat stores. The energetic stresses of overlap and short recuperative periods did not significantly affect fetal growth. The mother appears to buffer the energetic stress, protecting fetal growth. This research demonstrates that evidence of depletion of maternal nutrient stores caused by a demanding reproductive history is found when reproductive stress is characterized adequately.

Novel benzodiazepine receptor partial agonists: oxadiazolylimidazobenzodiazepines

The synthesis and biochemical evaluation of a series of oxadiazole derivatives of imidazobenzodiazepines related to the benzodiazepine antagonist Ro 15-1788 (2a) are reported. Although the oxadiazole ring is seen as an isosteric replacement for the ester linkage, significant differences in structure-activity trends were observed. Specifically, oxadiazoles 9-12 invariably had increased receptor efficacy (as witnessed by measurements of the GABA shift) relative to the corresponding ester. Additionally, and in direct contrast to the classical agonists such as diazepam, affinity for the benzodiazepine receptor was enhanced by a 7- rather than 8-halo substituent. The results are discussed in terms of a six-point receptor-binding model originally based on the X-ray structure of 2a. For comparison, the crystal structures of two representative oxadiazole derivatives, 10h and 12o, having a 6-oxo and 6-phenyl group, respectively, were determined and the data incorporated into a modified binding model to account for the greater efficacy of these compounds. It is concluded that the antagonist behavior of 2a relies upon the hydrogen-bond-acceptor properties of the ester carbonyl oxygen whereas for the oxadiazole series this site is localized at the imidazole nitrogen.

Effects of 3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethamphetamine isomers on central serotonergic, dopaminergic and nigral neurotensin systems of the rat

This study demonstrates that the isomers of 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA) are different in their ability to induce changes in serotonergic parameters and nigral concentrations of neurotensin-like immunoreactivity. With five successive doses (3.5 mg/kg) the d-MDA isomer was more potent than the l-MDA in its ability to decrease the concentrations of serotonin in the frontal cortex and hippocampus. The same difference occurred in the ability to decrease the hippocampal activity of tryptophan hydroxylase as well as the hippocampal and neostriatal 5-hydroxyindoleacetic acid concentrations. However, both isomers of MDMA were equipotent in their ability to decrease serotonergic parameters in the brain areas examined. When the doses were increased to 5 and 10 mg/kg, both isomers of MDA were equipotent in their effects on the serotonin system, whereas the l-MDMA was significantly less potent than its d isomeric counterpart in causing a decrease in serotonergic parameters of the different brain areas. In contrast, treatments with any of the isomers appeared to have a minimal impact on neostriatal dopaminergic parameters. However, treatment with MDA or MDMA caused increases in the nigral concentrations of neurotensin, with the d isomer of both compounds having substantially greater effects on this neuropeptide system. These increases are suspected to result from drug-released dopamine. This study demonstrates that at selected doses, the d isomers of MDA and MDMA are more potent than their l forms in affecting neurochemical systems, whereas high doses of either isomer of MDA share a common ability to induce changes in the serotonergic system that are likely associated with neuronal damage.

Effect of methamphetamine on neurotensin concentrations in rat brain regions

High doses of methamphetamine (METH) induced 200 to 300% increases in the neurotensin-like immunoreactivity (NTLI) concentrations of the substantia nigra and striatum in rats after a single or multiple drug doses; smaller but significant increases of 30 to 50% were observed in the hypothalamus and hippocampus after multiple, but not single, METH administrations whereas no measurable changes were detected in the NTLI levels of the periaqueductal gray area or the amygdala. These METH-induced increases in NTLI concentrations were attenuated by coadministration of haloperidol in the substantia nigra, hypothalamus and hippocampus, indicating a possible involvement of dopamine receptors in these tissues. In the striatum haloperidol alone produced significant increases in NTLI levels; these increases were additive with those induced by METH treatment demonstrating that the neurotensin pathways associated with the striatum are regulated differently from that of the other brain areas examined. The implications of these findings to the relationship between dopamine and neurotensin transmitter systems are discussed.

Comparison of responses by striatonigral substance P and neurokinin A systems to methamphetamine treatment

Multiple administrations of high doses of methamphetamine (METH) previously have been shown to significantly elevate the concentrations of substance P-like immunoreactivity in CNS regions associated with the basal ganglia. Recently, another tachykinin, neurokinin A (NKA), has been found to be closely associated with substance P (SP). While both neuropeptides exert comparable effects when locally injected, there are significant differences in their potencies apparently based on the relative concentrations of their unique receptors. Due to the controversy which has arisen as to their respective roles within the basal ganglia, we have evaluated and compared the responses of the striatal and nigral SP and NKA systems to METH treatment. We observed that multiple high doses of this stimulant increased the nigral and striatal concentrations of both neuropeptides in an identical fashion. Our observation that METH treatment did not alter the relative concentrations of SP and NKA suggests that responses of both transmitter systems, associated with the basal ganglia, parallel each other and are sensitive to the same regulatory mechanisms.

Postnatal triiodothyronine concentrations in healthy preterm infants and in infants with respiratory distress syndrome

Postnatal changes in triiodotyronine (T3) concentration were investigated in 12 preterm infants of 26-34 weeks of gestational age. Blood for measurement of T3 was obtained from the cord at delivery and from infants at 1 day of age and at weekly intervals for 4 weeks. Seven of the babies suffered from respiratory distress syndrome (RDS) and five were considred healthy. Gestational ages and body weight were comparable in both groups. In preterm infants with RDS, cord blood T3 concentration was significantly lower than that in cord blood of babies without RDS (22 +/- 2.6 versus 36 +/- 5 ng/dl, P less than 0.05). There was no significant rise in T3 concentration of RDS babies at 24 hr of age (22 +/- 2.6 versus 34.0 +/- 8 ng/dl, P greater than 0.05), and hypotriiodothyroninemia persisted for 3 weeks. At 4 weeks of age, T3 concentration in babies with RDS, although within the normal range (80-190 ng/dl), was significantly lower than that in the healthy preterm infants (110 +/- 10 versus 165 +/- 11 ng/dl, P less than 0.05). Postnatal T3 changes in healthy preterm infants wre characterized by the absence of the initial hypertriiodothyroninemia and by a gradual rise within the first month of life. The noted difference in the pattern of postnatal T3 changes in healthy preterm infants compared to full term infants may reflect thyroid immaturity. The machanism and the significance of the neonatal hypotriiodothyroninemia in RDS and its long term effects on the development of these babies remain to be investigated.