630. A 5-mRNA host response whole-blood classifier trained using patients with non-COVID-19 viral infections accurately predicts severity of COVID-19

Background

While major progress has been made to establish diagnostic tools for the diagnosis of SARS-CoV-2 infection, determining the severity of COVID-19 remains an unmet medical need. With limited hospital resources, gauging severity would allow for some patients to safely recover in home quarantine while ensuring sicker patients get needed care. We discovered a 5 host mRNA-based classifier for the severity of influenza and other acute viral infections and validated the classifier in COVID-19 patients from Greece.

Methods

We used training data (N=705) from 21 retrospective clinical studies of influenza and other viral illnesses. Five host mRNAs from a preselected panel were applied to train a logistic regression classifier for predicting 30-day mortality in influenza and other viral illnesses. We then applied this classifier, with fixed weights, to an independent cohort of subjects with confirmed COVID-19 from Athens, Greece (N=71) using NanoString nCounter. Finally, we developed a proof-of-concept rapid, isothermal qRT-LAMP assay for the 5-mRNA host signature using the QuantStudio 6 qPCR platform.

Results

In 71 patients with COVID-19, the 5 mRNA classifier had an AUROC of 0.88 (95% CI 0.80-0.97) for identifying patients with severe respiratory failure and/or 30-day mortality (Figure 1). Applying a preset cutoff based on training data, the 5-mRNA classifier had 100% sensitivity and 46% specificity for identifying mortality, and 88% sensitivity and 68% specificity for identifying severe respiratory failure. Finally, our proof-of-concept qRT-LAMP assay showed high correlation with the reference NanoString 5-mRNA classifier (r=0.95).

Figure 1. Validation of the 5-mRNA classifier in the COVID-19 cohort. (A) Expression of the 5 genes used in the logistic regression model in patients with (red) and without (blue) mortality. (B) The 5-mRNA classifier accurately distinguishes non-severe and severe patients with COVID-19 as well as those at risk of death.

Conclusion

Our 5-mRNA classifier demonstrated very high accuracy for the prediction of COVID-19 severity and could assist in the rapid, point-of-impact assessment of patients with confirmed COVID-19 to determine level of care thereby improving patient management and healthcare burden.

Disclosures

ljubomir Buturovic, PhD, Inflammatix Inc. (Employee, Shareholder) Purvesh Khatri, PhD, Inflammatix Inc. (Shareholder) Oliver Liesenfeld, MD, Inflammatix Inc. (Employee, Shareholder) James Wacker, n/a, Inflammatix Inc. (Employee, Shareholder) Uros Midic, PhD, Inflammatix Inc. (Employee, Shareholder) Roland Luethy, PhD, Inflammatix Inc. (Employee, Shareholder) David C. Rawling, PhD, Inflammatix Inc. (Employee, Shareholder) Timothy Sweeney, MD, Inflammatix, Inc. (Employee)

521. Similarities and Differences in Transcriptomic Host Response between SARS-CoV-2 and Other Viral Infections

Background

COVID-19 is a pandemic caused by the SARS-CoV-2 virus that shares and differs in clinical characteristics of known viral infections.

Methods

We obtained RNAseq profiles of 62 prospectively enrolled COVID-19 patients and 24 healthy controls (HC). We collected 23 independent studies profiling 1,855 blood samples from patients covering six viruses (influenza, RSV, HRV, Ebola, Dengue and SARS-CoV-1). We studied host whole-blood transcriptomic responses in COVID-19 compared to non-COVID-19 viral infections to understand similarities and differences in host response. Gene signature threshold was absolute effect size ≥1, FDR ≤ 0.05%.

Results

Differential gene expression of COVID-19 vs HC are highly correlated with non-COVID-19 vs HC (r=0.74, p< 0.001). We discovered two gene signatures: COVID-19 vs HC (2002 genes) (COVIDsig) and non-COVID-19 vs HC (635 genes) (nonCOVIDsig). Pathway analysis of over-expressed signature genes in COVIDsig or nonCOVIDsig identified similar pathways including neutrophil activation, innate immune response, immune response to viral infection and cytokine production. Conversely, for under-expressed genes, pathways indicated repression of lymphocyte differentiation and activation (Fig1).

Intersecting the two gene signatures found two genes significantly oppositely regulated (ACO1, ATL3). We derived a third gene signature using COCONUT to compare COVID-19 to non-COVID-19 viral infections (416 genes) (Fig2). Pathway analysis did not result in significant enrichment, suggesting identification of novel biology (Fig1).

Statistical deconvolution of bulk transcriptomic data found M1 macrophages, plasmacytoid dendritic cells, CD14+ monocytes, CD4+ T cells and total B cells changed in the same direction across COVID-19 and non-COVID-19 infections. Cell types that increased in COVID-19 relative to non-COVID-19 were CD56^bright NK cells, M2 macrophages and total NK cells. Those that decreased in non-COVID-19 relative to COVID-19 were CD56^dim NK cells & memory B cells and eosinophils (Fig3).

Figure 1

Figure 2

Figure 3

Conclusion

The concordant and discordant responses mapped here provide a window to explore the pathophysiology of COVID-19 vs other viral infections and show clear differences in signaling pathways and cellularity as part of the host response to SARS-CoV-2.

Disclosures

Simone A. Thair, PhD, Inflammatix, Inc. (Employee, Shareholder) Yudong He, PhD, Inflammatix Inc. (Employee) Yehudit Hasin-Brumshtein, PhD, Inflammatix (Employee, Shareholder) Suraj Sakaram, MS in Biochemistry and Molecular Biology, Inflammatix (Employee, Other Financial or Material Support, stock options) Rushika R. Pandya, MS, Inflammatix Inc. (Employee, Shareholder) David C. Rawling, PhD, Inflammatix Inc. (Employee, Shareholder) Purvesh Khatri, PhD, Inflammatix Inc. (Shareholder) Timothy Sweeney, MD, PHD, Inflammatix, Inc. (Employee, Shareholder)

Transcriptomic similarities and differences in host response between SARS-CoV-2 and other viral infections

The pandemic 2019 novel coronavirus disease (COVID-19) shares certain clinical characteristics with other acute viral infections. We studied the whole-blood transcriptomic host response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using RNAseq from 24 healthy controls and 62 prospectively enrolled patients with COVID-19. We then compared these data to non-COVID-19 viral infections, curated from 23 independent studies profiling 1,855 blood samples covering six viruses (influenza, respiratory syncytial virus (RSV), human rhinovirus (HRV), severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1), Ebola, dengue). We show gene expression changes in COVID-19 versus non-COVID-19 viral infections are highly correlated (r = 0.74, p < 0.001). However, we also found 416 genes specific to COVID-19. Inspection of top genes revealed dynamic immune evasion and counter host responses specific to COVID-19. Statistical deconvolution of cell proportions maps many cell type proportions concordantly shifting. Discordantly increased in COVID-19 were CD56^bright natural killer cells and M2 macrophages. The concordant and discordant responses mapped out here provide a window to explore the pathophysiology of the host response to SARS-CoV-2.

Cost-utility analysis in orthopaedic trauma; what pays? A systematic review

BACKGROUND

As healthcare systems come under ever-increasing pressure to provide more care with fewer resources, emphasis is being placed on value-based systems that maximise quality and minimize cost. The aim of this study was to determine which interventions in fracture care have been demonstrated to be cost effective.

METHODS

A systemic review of cost-utility studies on the management of fractures from 1976 to 2015 was carried out using a search of the Cost-Effectiveness Analysis Registry, National Health Service Economic Evaluation Database (NHS EED) and MEDLINE.

RESULTS

20 studies were included with 15 (75%) studies assessing interventions in lower limb trauma and 8 (25%) studies assessing interventions in upper limb trauma. 50% of studies used a decision tree model and 50% used collected data alongside a randomised clinical trial. Interventions which were shown to be cost effective in lower limb trauma were total hip replacement in displaced femoral neck fractures, the SHS in stable (A1 and A2) fractures and IM nailing for unstable (A3) fractures, salvage treatment for grade IIIB and IIIC open tibial fractures and operative treatment of ankle and calcaneal fractures. For systems-based strategies, there is evidence demonstrating cost effectiveness to treating hip fractures in high volume centres and to having resources in place to facilitate fractures being treated within 48 h of injury. In upper limb trauma there was evidence showing operative treatment of displaced proximal humerus fractures to be neither clinically nor cost effective. There was evidence supporting the operative treatment of non-displaced scaphoid fractures. Overall the quality of the studies was poor with only 50% (10) of studies able to make a treatment recommendation. Reasons for this included poor quality primary source data and poor reporting methodological practices.

CONCLUSION

Certain aspects of fracture management have been shown to be cost effective. However, there is a paucity of evidence in this area and further research is required so that value-based interventions are chosen by healthcare providers engaged in orthopaedic trauma care.

Impact of patient suicide on front-line staff in Ireland

Research and anecdotal evidence suggests that coming to terms with the suicide of a patient can be extremely distressing for front-line professionals. Some research also suggests that exposure to such situations can undermine professionals' functioning and feelings of competence, cause them to question their professional standing and ultimately contribute to burnout. A survey of 447 front-line professionals' experiences of patient suicide was undertaken to further explore these issues. Thematic analysis of open-ended questionnaire items revealed that concerns for the bereaved family, feelings of responsibility for the death and having a close therapeutic relationship with the client are key factors that influence the adjustment and coping of a health professional in the aftermath of the death of a client by suicide. The results are discussed with a focus on the impact of suicide on front-line staff, the need for ongoing support and training and the development of specific post-suicide protocols.

Physiological noise in near-infrared spectroscopy: implications for optical brain computer interfacing

Near-infrared spectroscopy is a non-invasive optical method used to detect functional activation of the cerebral cortex. Cognitive, visual, auditory and motor tasks are among the functions that have been investigated by this technique in the context of optical brain computer interfacing. In order to determine whether the optical response is due to a stimulus, it is essential to identify and reduce the effects of physiological noise. This paper characterizes noise typically present in optical responses and reports signal processing approaches used to overcome such noise.

Optical properties of nanostructured metal films

Nanostructured metal films of platinum, gold and silver up to 675 nm thick we prepared by electrochemical deposition through templates of 700 nm diameter polystyrene spheres assembled as hexagonal close packed monolayer on an evaporated gold surface followed by removal of the template by dissolution in tetrahydrofuran. The reflection spectra of the films at normal incidence were recorded as a function of film thickness and the spectra correlated with the local visual appearance of the film and the surface structure from SEM. For thin films, below one quarter sphere height, the spectra show a single reflectivity dip at a wavelength just below the sphere diameter consistent with surface-plasmon grating-like behaviour. For the thicker films several reflectivity dips are observed which move towards longer wavelength with increasing film thickness. This behaviour is shown to be consistent with a model in which light reflected from the top of the structure interferes with light reflected from within the spherical segment cavities in the film.

Confined plasmons in metallic nanocavities

We investigate the properties of gold surfaces patterned using a nanoscale "lost wax" technique by electrochemical deposition through a self-assembled latex template. Near-spherical gold nanocavities within the resulting porous films support localized surface plasmons which couple strongly to incident light, appearing as sharp spectral features in reflectivity measurements. The energy of the resonances is easily tunable from ultraviolet to near infrared by controlling the diameter and height of the nanocavities. The energies of these features agree well with the Mie resonances of a perfect spherical void.

Olfactory conditioning facilitates diet transition in human infants

We evaluated whether Pavlovian conditioning methods could be used to increase the ingestion of non-preferred solutions by formula-fed human infants. In baseline measures, 5-7 month old infants sucked less frequently and consumed less water than regular formula. During a 3-day olfactory conditioning period, parents placed a small scented disk, the conditioned stimulus, on the rim of their infants' formula bottle at every feeding. Following this training, infants' responses to water were tested when their water bottles had a disk scented with the training odor, a novel odor, or no odor. Infants tested with the training odor sucked more frequently and consumed significantly more water than they had at baseline. Infants tested with no odor or a novel odor consumed water at or below baseline levels. These data demonstrate that olfactory conditioning can be used to enhance ingestion in infants and suggest that such methods may be useful for infants experiencing difficulty when making transitions from one diet to another.

Altered cell cycle response of drug-resistant lung carcinoma cells to doxorubicin

The effect of doxorubicin treatment on cell cycle parameters in asynchronous populations of multidrug-resistant human lung carcinoma cell lines was investigated. A sensitive (DLKP-SQ) and three resistant (DLKP-SQ A250 10p#7, DLKP-A2B and DLKP-A5F) variants of a human lung carcinoma cell line DLKP were exposed to equitoxic concentrations of doxorubicin. The latter three were 8-fold, 30-fold and 300-fold resistant to doxorubicin, respectively. Irreversible G2/M arrest in sensitive (DLKP-SQ) cells was observed 24 h after initiation of doxorubicin treatment. In resistant variants, G2/M arrest occurred at 12-16 h with a subsequent bypass of the G2/M arrest to re-emerge and accumulate in G1. This transient G2/M arrest and subsequent progression into G1 indicated an inefficient checkpoint for monitoring DNA damage induced by doxorubicin treatment. Caffeine treatment could bypass the G2/M block in DLKP-SQ cells. Doxorubicin treatment did not alter cyclin B or cdc2 protein levels, the ability of cdc2 to form complexes with cyclin B or the levels of cyclin B bound to cdc2. The G2/M arrest seen in sensitive cells was associated with an increase in inhibitory phosphorylation of Tyr15 on cdc2. In contrast, tyrosine 15 phosphorylation did not change in resistant variants after drug treatment and a general increase in cdc2 kinase activity was seen. Cdc25C levels were not altered following drug treatment.

HIV risk behaviors associated with the injection process: multiperson use of drug injection equipment and paraphernalia in injection drug user networks

This study examines drug acquisition and multiperson use of paraphernalia, drugs, and needles/syringes. Ethnographers observed 54 injection episodes in which IDUs were linked by HIV risk behaviors, and developed a typology of higher-risk, lower-risk, and nonsharing-risk networks. Multiperson use of injection paraphernalia or drug solution occurred in most injection events (94%). Serial use of syringes/needles occurred infrequently (14%) relative to "backloading" (37%) and reuse of paraphernalia (cookers 84%, cotton 77%, water 77%). Higher-risk injection networks were characterized by larger size and pooling of resources for drugs. Prevention messages must include avoiding reuse of injection paraphernalia and transfer of drug solution.

HIV serostatus and risk behaviors in a multisite sample of drug users

In developing HIV prevention efforts, it is critical to determine whether interventions are effective in achieving declines in risk behavior among both HIV-positive and HIV-negative individuals. Based on a multisite intervention study of injection drug users (IDUs) and crack smokers, 488 seropositive IDUs and 364 seropositive crack users were compared with randomly selected matched samples of seronegatives (with matching based on recruitment site, gender, age group and ethnicity) at baseline and six-month follow-up to compare changes in risk behaviors by serostatus. Results indicated that overall, risk behaviors declined substantially over time; significant interaction effects indicated that seropositives reported a greater decline in sex risk behaviors than seronegatives. These data support the utility of HIV testing for high-risk drug users, and indicate that interventions have produced reductions in risk behaviors of both seropositives and seronegatives. Further research on the impact of site seroprevalence, and to enhance our understanding of those who continue to engage in risky behaviors, is needed.

Enhancement of chemotherapeutic drug toxicity to human tumour cells in vitro by a subset of non-steroidal anti-inflammatory drugs (NSAIDs)

The effect on cytotoxicity of combining a range of clinically important non-steroidal anti-inflammatory drugs (NSAIDs) with a variety of chemotherapeutic drugs was examined in the human lung cancer cell lines DLKP, A549, COR L23P and COR L23R and in a human leukaemia line HL60/ADR. A specific group of NSAIDs (indomethacin, sulindac, tolmetin, acemetacin, zomepirac and mefenamic acid) all at non-toxic levels, significantly increased the cytotoxicity of the anthracyclines (doxorubicin, daunorubicin and epirubicin), as well as teniposide, VP-16 and vincristine, but not the other vinca alkaloids vinblastine and vinorelbine. A substantial number of other anticancer drugs, including methotrexate, 5-fluorouracil, cytarabine, hydroxyurea, chlorambucil, cyclophosphamide, cisplatin, carboplatin, mitoxantrone, actinomycin D, bleomycin, paclitaxel and camptothecin, were also tested, but displayed no synergy in combination with the NSAIDs. The synergistic effect was concentration dependent. The effect appears to be independent of the cyclo-oxygenase inhibitory ability of the NSAIDs, as (i) the synergistic combination could not be reversed by the addition of prostaglandins D2 or E2; (ii) sulindac sulphone, a metabolite of sulindac that does not inhibit the cyclooxygenase enzyme, was positive in the combination assay: and (iii) many NSAIDs known to be cyclo-oxygenase inhibitors, e.g. meclofenamic acid, diclofenac, naproxen, fenoprofen, phenylbutazone, flufenamic acid, flurbiprofen, ibuprofen and ketoprofen, were inactive in the combination assay. The enhancement of cytotoxicity was observed in a range of drug sensitive tumour cell lines, but did not occur in P-170-overexpressing multidrug resistant cell lines. However, in the HL60/ADR and COR L23R cell lines, in which multidrug resistance is due to overexpression of the multidrug resistance-associated protein MRP, a significant increase in cytotoxicity was observed in the presence of the active NSAIDs. Subsequent Western blot analysis of the drug sensitive parental cell lines, DLKP and A549, revealed that they also expressed MRP and reverse-transcription-polymerase chain reaction studies demonstrated that mRNA for MRP was present in both cell lines. It was found that the positive NSAIDs were among the more potent inhibitors of [3H]-LTC4 transport into inside-out plasma membrane vesicles prepared from MRP-expressing cells, of doxorubicin efflux from preloaded cells and of glutathione-S-transferase activity. The NSAIDs did not enhance cellular sensitivity to radiation. The combination of specific NSAIDs with anticancer drugs reported here may have potential clinical applications, especially in the circumvention of MRP-mediated multidrug resistance.

Correlation between Acute Physiology and Chronic Health Evaluation (APACHE) III score and immunological parameters in critically ill patients with sepsis

A relationship between physiological parameters of severe sepsis and immunological function has not been established. In ten severely ill patients with sepsis physiological risk was assessed by the Acute Physiology and Chronic Health Evaluation (APACHE) III score, while one component of immunological function was evaluated using peripheral blood mononuclear cell (PBMC) cytokine production after stimulation with lipopolysaccharide (LPS) in vitro. Five of the ten patients died. Mean (s.e.m.) APACHE III scores at admission were not significantly different between survivors and non-survivors (82(13) versus 95(13)) but after 72 h they were lower in survivors (51(13) versus 111(15), P < 0.05). Downregulation of cytokine production by PBMC on LPS stimulation was a transient event in survivors. Survivors had a three-fold increase in tumour necrosis factor alpha bioactivity within 72 h, but there was no increase in non-survivors. A similar pattern was demonstrated for interleukin (IL) 1 beta (P < 0.05 between survivors and non-survivors) and IL-6 (P = 0.06) immunoactivity. Physiological as well as immunological parameters in critically ill patients with sepsis independently predicted hospital survival (r2 = 0.2). These data demonstrate a relationship between the pattern of cytokine production in vitro and survival.

mdr1 ribozyme mediated reversal of the multi-drug resistant phenotype in human lung cell lines

An mdr1 hammerhead was introduced into two adriamycin-selected multi-drug resistant human lung cell lines both of which over-express p-glycoprotein. Expression of the ribozyme resulted in a decrease in mdr1 mRNA expression and an increase in drug sensitivity in both cell lines. This would suggest that the use of specific ribozymes may represent an effective and specific approach in order to restore cellular sensitivity towards anti-cancer drugs.

The P300 ERP component: an index of cognitive dysfunction in depression?

A number of measures of brain function have suggested that depression is associated with cerebral hypoactivity. This study examines the late components of the event-related potential (ERP), in particular the P300 component, in depression. The P300 component is thought to index the updating of neurocognitive models which are concerned with the prediction of future events. Cognitive theories of depression include the proposition that depression may be characterized by abnormalities in the prediction of future events. The P300 component may therefore provide one neurophysiological index of cognitive dysfunction in depression. Twenty-seven subjects (14 medicated, 13 drug-free) fulfilling DSM-III criteria for Major Depression were compared to 27 age- and sex-matched normal controls. The amplitudes and latencies of N100, P200, N200 and P300 ERP components, reaction time and task accuracy were recorded during a standard auditory discrimination task. No significant differences were found in any ERP component measure or in reaction-time between the groups. Depressed subjects performed the experimental task significantly less accurately than normal controls, but this was not reflected in the ERPs.

The metabolic effects of platelet-activating factor antagonism in endotoxemic man

OBJECTIVE

To determine if the inflammatory phospholipid platelet-activating factor (PAF) participated in the symptomatologic, metabolic, and counterregulatory hormonal responses of human endotoxemia.

DESIGN

In a double-blind, placebo-controlled study, five subjects received 10 mg of the PAF antagonist Ro 24-4736 orally, while five control subjects received a placebo. Eighteen hours later, all subjects were administered 4 ng/kg of endotoxin (lipopolysaccharide) intravenously.

SETTING

The Clinical Research Center of The New York Hospital-Cornell Medical Center.

PARTICIPANTS

Healthy male volunteers.

MAIN OUTCOME MEASURES

Repeated measurements of vital signs, symptoms, cytokine and hormone levels, resting energy expenditure, platelet aggregation, and bleeding times were performed during a 24-hour period.

RESULTS

Subjects who were pretreated with the PAF antagonist experienced fewer symptoms, including rigors at 1 hour (P < .05) and myalgias at 1 through 4 hours (P < .05) after administration of lipopolysaccharide. This was in concert with a diminished peak cortisol level (668 +/- 107 vs 959 +/- 159 nmol/L in controls; P < .05), epinephrine secretion (1057 +/- 165 vs 2029 +/- 431 nmol/L in controls; P < .05), and almost complete inhibition of PAF-induced platelet aggregation ex vivo.

CONCLUSIONS

These findings in the face of unaltered circulating cytokines tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6, as well as the tumor necrosis factor receptor-I s, suggest that PAF may influence some endotoxin-induced, counterregulatory hormonal responses and symptoms through cytokine-independent mechanisms. This study further supports the role of PAF antagonists as an adjunct to cytokine blockade in the treatment of gram-negative sepsis.

Early diagnosis of ectopic arginine vasopressin secretion

We describe a patient who presented with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) 2 months before clinical evidence of bronchogenic malignancy. Because of the potential for the ectopic production of atrial natriuretic peptide (ANP) to mimic SIADH, both hormones were measured in this hyponatremic patient to seek a possible marker of tumor activity. A hypertonic saline infusion at presentation revealed excessive osmotically decoupled secretion of arginine vasopressin but a normal ANP response.

Early diagnosis of ectopic arginine vasopressin secretion

We describe a patient who presented with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) 2 months before clinical evidence of bronchogenic malignancy. Because of the potential for the ectopic production of atrial natriuretic peptide (ANP) to mimic SIADH, both hormones were measured in this hyponatremic patient to seek a possible marker of tumor activity. A hypertonic saline infusion at presentation revealed excessive osmotically decoupled secretion of arginine vasopressin but a normal ANP response.

The effects of age on auditory event-related potentials

The effects of age on event-related potentials (ERPs) elicited during a two-tone discrimination ("oddball") task were examined in 97 normal subjects aged from 17-80 years. Strong relationships were found between age and the latencies of the later ERP components N200 and P300. Furthermore the correlation between age and N200 latency at Pz was marginally higher than that of age and P300 latency. For the entire sample, the increase in P300 latency as a function of age was best described at Cz and Pz by linear regression equations. However, a segmented line model better described the P300/age relationship at Fz--the increase in P300 latency with age in subjects over 61 was five times that of subjects younger than 61 years. In this study the task required button-press identification of the targets--the significance of increased age and a delay in N200 latency is discussed with reference to the possibility of N200 latency indexing the speed of cognitive processing.

Normal latency of the P300 event-related potential in mild-to-moderate Alzheimer's disease and depression

A two-tone-discrimination task was used to elicit the P300 component of event-related (brain) potentials (ERPs) from patients with presumed Alzheimer's dementia of mild or moderate severity, depressed patients of older age, and cognitively normal individuals. Although the average P300 latency of the Alzheimer patients was greater than that of the depressed patients, which in turn was greater than that of older aged normals, none of the group differences in latency were statistically significant. Moreover, when latency was examined on an individual basis, less than one-quarter of the Alzheimer patients had an abnormally delayed P300 for their age. Reaction times and the percentage of correct behavioral responses to the tones did distinguish the Alzheimer from the normal group; on both measures the patients' scores were significantly worse. It was concluded that the performance of a simple tone discrimination task requiring a button-press response does not sufficiently tax those cognitive functions impaired in the earlier stages of Alzheimer's dementia to result in abnormally slowed cognitive processing of the kind reflected in P300 latency.

The trometamol salt of fosfomycin: microbiological evaluation

The spectrum of activity of fosfomycin and its pharmacological behaviour make it an attractive candidate for the oral treatment of uncomplicated urinary tract infection. Various factors affect the antibacterial activity so that results in different culture media vary widely. The highest activity was displayed in Eugonbroth and such results correlated well with those obtained in pooled human urine. The activity was enhanced in acid conditions such as commonly exist in infected urine. Glucose-6-phosphate potentiated the activity of fosfomycin against Escherichia coli and some other bacteria when tested in Eugonbroth (but less predictably in human urine) and the potentiating effect may be necessary in order to obtain therapeutically meaningful results in susceptibility tests. Experiments in an in vitro model of the treatment of bacterial cystitis (carried out in the absence of glucose-6-phosphate) indicated that both sensitive and 'resistant' strains of E. coli respond to concentrations of fosfomycin achievable by high-dose oral therapy with the trometamol salt. Resistance did not emerge in previously sensitive strains (or in one of the 2 'resistant' strains), providing a high peak level of antibiotic was achieved.

Ontogeny of tolerance to haloperidol: behavioral and biochemical measures

Developing and adult Sprague-Dawley rats were tested after acute or repeated haloperidol administration. Although 8-day-old rat pups showed a form of immobility in response to a single injection of haloperidol (1 mg/kg), 14-day-old rats did not show any behavioral response to the neuroleptic. By 21 days of age, an acute dose of haloperidol induced a cataleptic response similar to that described for adult animals. Following 7 days of repeated haloperidol administration, the cataleptogenic effects of haloperidol were attenuated in animals aged 21 days and older, but not in 8- and 14-day-old rats. Subjects were sacrificed 70 min after the injection of the test dose of haloperidol or saline and the corpus striatum and olfactory tubercles were dissected for HPLC determination of dopamine (DA) and its metabolites, homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC). In the corpus striatum, an area believed to be important for DA-related catalepsy, acute and repeated haloperidol induced a slight increase in concentrations of HVA in 8-day-old rats, and an increase in both DOPAC and HVA concentrations in animals aged 14 days and older. Tolerance after repeated haloperidol administration, in the form of an attenuation of the haloperidol-induced increase in DA metabolites, was not apparent until 35 days of age. These data contrast with the behavioral data, which indicate that the ability to develop a tolerance to the cataleptogenic effects of haloperidol matures by 21 days of age. The pattern of responses in the olfactory tubercles differed from those observed in the striatum. Following acute haloperidol, subjects did not show any increase in HVA until 14 days of age, and in both HVA and DOPAC until 21 days of age. At no age, including adults, was one week of repeated administration of haloperidol sufficient to induce tolerance to the effects of haloperidol on DA metabolites in the olfactory tubercles. In addition to providing information about the development of certain aspects of DA systems in rats, these studies suggest that an attenuation of the haloperidol-induced increase in DA metabolites is not necessary for the development of tolerance to haloperidol-induced catalepsy.

Effects of TRH, ethanol, and TRH-ethanol combination on activity in rats with altered monoamine content

Investigations were undertaken with 5,7-dihydroxytryptamine and 6-hydroxydopamine treated rats to see whether activity changes induced by TRH, ethanol and the TRH-ethanol combination would be affected after reduced monoamine function. In keeping with earlier results, TRH increased activity, ethanol reduced activity and the TRH-ethanol combination produced activity counts greater than those for TRH alone. Neither the 5,7-dihydroxytryptamine-induced reduction of brain serotonin nor the 6-hydroxydopamine treatments which reduced brain catecholamines altered the hyperactivity induced by TRH or the TRH-ethanol combination. While reduction of brain serotonin did not affect the ethanol-induced changes in activity, preferential reduction of dopamine as well as reduction of both norepinephrine and dopamine significantly antagonized this measure of ethanol-induced depression. The reduction of dopamine alone produced the greatest effect on this action of ethanol. It can be concluded from the data that the increased locomotion induced by TRH and the TRH-ethanol combination does not depend upon endogenous monoamines, whereas the sedative effects of ethanol are apparently influenced by alterations in brain catecholamine function.

Ontogeny of striatal unit activity and effects of single or repeated haloperidol administration in rats

Development of striatal unit activity recorded from chloral hydrate anesthetized, neonatal rats was characterized electrophysiologically following acute or repeated haloperidol administration. No spontaneously active single units were detected in 8 day old pups. Spontaneous activity was recorded by 17 days of age, although the number of active cells, firing frequency and the variety of firing patterns were less diverse than those observed in 28 day olds. There were also age related differences in striatal unit responses to haloperidol. A significant increase in activity was induced by acute haloperidol administration only in 28 day old animals. No tolerance to the acute effects was demonstrated. Both 17 and 28 day olds responded to repeated haloperidol injections, followed by a 24 h recess, with an increase in striatal activity. These results may assist our understanding of the effects of human fetal, neonatal and/or adolescent exposure to neuroleptics.

Early postnatal administration of 5,7-DHT: effects on serotonergic neurons and terminals

Serotonergic neurons throughout the brain were destroyed by early postnatal treatment of rats with an intracisternal injection of 5,7-dihydroxytryptamine (5,7-DHT), as demonstrated with biochemical measurements of serotonin and immunocytochemical localization of serotonin-containing neurons. Using these methods, it was shown that approximately 75-98% of serotonergic neurons underwent cell death in rats which were treated on day 3. In contrast, intracisternal administration of 5,7-DHT in adult rats led to the loss of distal serotonergic terminals without apparent loss of the cell bodies. Desipramine pretreatment prevented significant effects of 5,7-DHT on noradrenergic neurons.

Ethanol-induced locomotor stimulation in rats after thyrotropin-releasing hormone

Ethanol-induced sedation in Sprague-Dawley rats was antagonized by intracisternally administered thyrotropin releasing hormone (TRH) at a dose as low as 1 microgram. Furthermore, when a dose of 25 micrograms or greater of TRH was combined with ethanol doses above 2 g/kg, the locomotor activity was significantly greater than observed for TRH alone. A dose-related increase in activity was observed when varying doses of ethanol were administered with a constant dose of TRH (100 micrograms). This increase in locomotion induced by the TRH-ethanol combination could not be attributed to a change in TRH concentration, ethanol distribution or to a pituitary action of TRH. Inasmuch as tert-butanol in combination with TRH produced the same effects as ethanol, the hyperactivity does not appear to be associated with acetaldehyde formation. TRH acid and His-Pro-diketopiperazine, metabolites of TRH, did not produce hyperactivity when administered with ethanol, whereas MK-771, a TRH analog, produced a significant increase in locomotion in ethanol-treated rats greater than that for MK-771 alone. Three lines of evidence suggested that the hyperactivity induced by the TRH-ethanol combination could not be attributed to an influence of ethanol on the stimulant effects of TRH. First, pentobarbital- and chlordiazepoxide-induced depression of locomotion was antagonized by TRH (100 micrograms) but, unlike ethanol, locomotor stimulation greater than that for TRH was not observed. Second, behavioral observations did not reveal ethanol altering any effects of TRH that would compete with locomotion.(ABSTRACT TRUNCATED AT 250 WORDS)

The pituitary-adrenal response to novel stimulation and ether stress in young adult and aged rats

Pituitary-adrenal responsiveness to stress induced by either psychological (novelty) or physiological (ether) stimuli was examined in young (3 to 6 months) and old (24 to 27 months) male and female rats. In Experiment 1, subjects were placed in a novel environment for 3 min. Blood samples were collected at 0, 15, 30, 45, and 60 min. In Experiment 2, a blood sample was collected from experimental subjects immediately following 15 min in a novel environment; a basal sample was collected from control subjects. In Experiment 3, basal and stress blood samples were collected from subjects exposed to ether vapors. Blood samples were assayed for plasma corticosterone content. The major findings were: (1) no change with age in either sex in basal corticosterone levels or in the time course of the adrenocortical response; (2) no change with age in males in stress-induced increments in corticoids; (3) no change with age in females in corticoid elevations induced by a mild stressor (Experiment 1), but a decrement in elevations induced by more potent stressors (Experiments 2 and 3).

Hippocampal lesion effects on conditioned taste aversion and pituitary-adrenal activity in rats

A series of experiments examined the effects of hippocampal lesions on conditioned taste aversion (CTA) and pituitary-adrenal activity. Experiment 1 examined recovery from a conditioned taste aversion under conditions of free extinction. Hippocampal and unoperated rats recovered from the aversion at the same rate. Further, this experiment showed that the suppression in drinking in both groups produced by lithium chloride (LiCl) injection was a conditioned taste aversion (was dependent upon the pairing of the taste stimulus with LiCl) and not enhanced neophobia. In Experiment 2 there were no behavioral effects of the lesion in a forced extinction CTA paradigm. In addition, hippocampal lesions failed to alter pituitary-adrenal responsiveness to LiCl. In the same experiment, pituitary-adrenal responsiveness of hippocampectomized rats, when re-exposed to the taste paired earlier with LiCl, was altered. Hippocampal lesions eliminated the elevation in corticosterone shown by unoperated control and neocortical-lesioned rats. The third experiment replicated this finding showing again that hippocampal-lesioned rats failed to show the forced extinction elevation in corticosterone when exposed to the aversive taste (Experiment 3). These data were integrated with other reports of behavioral and pituitary-adrenal alterations in hippocampal-lesioned rats.

Altered plasma corticosterone responses during lactation in mice of two inbred strains

Plasma corticosterone levels during lactation were examined in inbred A/J (A) and C57BL/6J (C) mice. Following shock, lactating A females showed a diminished corticosterone response relative to nonlactating controls on day 5 of lactation, but not on day 12. In contrast, plasma corticosterone levels of lactating C females 5 and 15 min following shock were lower than those of controls on day 12, but not on day 5. Consistent with these findings, lactating A females had significantly lower plasma levels of corticosterone 15 min following nonnociceptive treatments (involving distrubance, exposure to novelty, and pup manipulation) when tested on day 5 then they did when tested on day 12, whereas lactating C females had lower levels on day 12 than on day 5. Lactating females of each strain showed the same response to shock on day 12 if they reared A pups as they did if they reared C pups. This indicates that the difference found between the strains on day 12 was due to a difference in some property of A and C mothers, rather than to a difference in a characteristic, such as suckling patterns, of the pups of the two strains. It was also found that at long intervals following shock (45 and 90 min) 5-day lactating C females had higher levels of plasma corticosterone than did controls. There was no effect of lactation on resting adrenocorticoid levels in A or C females at either 5 or 12 days. The results indicate that laboratory mice show changes in hypothalamo-pituitary-adrenal activity during lactation which both vary with strain of the mother, and differ in several respects from those previously reported for rats.

Effects of prior aversive stimulation on heart rate responses to open field exposure in the rat

Heart rate (HR) responses to open field (OF) exposure were compared between rats previously exposed to intense, inescapable electric shock (preshock, PS) and Controls. Results indicated that (1) Control animals showed a steady increase in HR across a 3 min exposure on each of 4 days of testing, while PS animals showed an initial HR deceleration followed by partial recovery on each day; (2) the HR response of PS animals in the OF was not related to any HR response to shock during treatment; and (3) the HR responses of both PS and Control animals were specific to the OF situation, with both groups showing steady HR deceleration across 3 min after being placed in their home cages. Results were discussed in terms of (1) the apparently altered perception of environmental change produced by PS, and (2) the possible role of HR acceleration in Controls in terms of minimizing the impact of aversive stimulation.