The role of the circadian clock in cancer hallmark acquisition and immune-based cancer therapeutics

The circadian system temporally regulates physiology to maintain homeostasis. Co-opting and disrupting circadian signals appear to be distinct attributes that are functionally important for the development of a tumor and can enable or give rise to the hallmarks that tumors use to facilitate their initiation, growth and progression. Because circadian signals are also strong regulators of immune cell proliferation, trafficking and exhaustion states, they play a role in how tumors respond to immune-based cancer therapeutics. While immuno-oncology has heralded a paradigm shift in cancer therapeutics, greater accuracy is needed to increase our capability of predicting who will respond favorably to, or who is likely to experience the troubling adverse effects of, immunotherapy. Insights into circadian signals may further refine our understanding of biological determinants of response and help answer the fundamental question of whether certain perturbations in circadian signals interfere with the activity of immune checkpoint inhibitors. Here we review the body of literature highlighting circadian disruption as a cancer promoter and synthesize the burgeoning evidence suggesting circadian signals play a role in how tumors respond to immune-based anti-cancer therapeutics. The goal is to develop a framework to advance our understanding of the relationships between circadian markers, cancer biology, and immunotherapeutics. Bolstered by this new understanding, these relationships may then be pursued in future clinical studies to improve our ability to predict which patients will respond favorably to, and avoid the adverse effects of, traditional and immune-based cancer therapeutics.

Human neutrophils depend on extrinsic factors produced by monocytes for their survival response to TLR4 stimulation

LPS delays neutrophil apoptosis by a process generally assumed to involve cell-intrinsic TLR4 signaling. However, neutrophil survival responses to LPS have been reported to be monocyte-dependent, which would indicate more complexity than is currently appreciated. We compared the survival responses of conventionally purified vs highly purified neutrophils to confirm or refute the need for secondary cell-types and to identify the cellular or molecular mechanisms involved. Direct stimulation of TLR4 failed to extend the survival of highly purified neutrophils, but survival activity was retained in less pure neutrophil preparations containing low numbers of eosinophils, monocytes, platelets and CD3+ lymphocytes. Sequential depletions identified monocytes as the only cell type required. Transfer of culture supernatants after lipid A-conditioning revealed that purified monocytes were sufficient for production of nearly all of the survival activity observed in mixed populations. The survival factors secreted upon TLR4 stimulation remain unidentified, but were not correlated with IL-1β, IL-6 or TNF-α nor could survival activity be inhibited by Ab blockade of IL-8 or of several other candidate factors other than endogenously produced GM-CSF, which was responsible for about one-tenth of the survival activity present in conditioned supernatants. These observations confirm that ex vivo neutrophil survival responses to TLR4 agonists are not cell intrinsic and involve potentially novel factors secreted by TLR4-stimulated monocytes.

The Effect of Age upon the Interrelationship of BMI and Inpatient Health Outcomes

OBJECTIVES

There is growing evidence that the relationship between body mass index (BMI - defined as weight in kilograms divided by height in metres squared) and patient outcomes is age-dependent; specifically, a raised BMI may have a protective effect in older adults. This has been demonstrated clearly in the community setting; less clear is the effect of age on this relationship in the inpatient setting.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

Retrospective analysis of 22,903 electronic records for patients discharged from two large public hospitals in South Australia between January 2015 and September 2018 inclusively. Records were retained if the patient's height and weight had been recorded during the admission, BMI was between 10-99 kg/m2 and it was the patient's first admission during that time. Patients were grouped by BMI (<18.5 kg/m2 ("underweight"), 18.5-24.9 kg/m2 ("normal weight"), 25-29.9 kg/m2 ("overweight"), >30 kg/m2 ("obese")) and age (18-59 years, 60-79 years, > 80 years); for each group we measured the relative stay index (RSI) (actual length of stay divided by predicted length of stay), death in hospital and composite adverse outcome after discharge (unplanned readmission within 30 days and/or death within 30 days).

RESULTS

Underweight patients across all age groups generally experienced significantly poorer outcomes compared to those not underweight. In those aged 18-59 years there were no significant differences in outcomes between the normal weight, overweight and obese groups. In those aged 60-79 years overweight patients had a significantly reduced risk of RSI > 2 compared to those of normal weight (p=0.014), and both overweight and obese patients had a significantly reduced risk of adverse outcome after discharge when compared to those of normal weight (p=0.028 and p=0.009 respectively). In those aged 80 years or older, both overweight and obese patients had a significantly reduced risk of adverse outcome after discharge when compared to those of normal weight (p=0.028 and p=0.013 respectively), and obese patients had a significantly reduced risk of inpatient mortality and RSI >2 when compared to those of normal weight (p=0.027 and p=0.037 respectively).

CONCLUSION

A BMI > 25 kg/m2 in older patients is associated with reduced risk of prolonged admission, inpatient mortality and adverse outcomes following discharge. This adds to growing evidence that age-specific BMI guidelines are required for adults because the healthiest BMI in the older hospital patient is seemingly not in the range 18.5-24.9 kg/m2.

Biomechanical Aspects of Fixed Ladder Climbing: Style, Ladder Tilt and Carrying

This study aims to understand the effects of climbing style (hands on rungs vs. hands on rails), ladder pitch and bank, and carrying objects on hand and foot forces. An instrumented ladder was constructed to OSHA 1910.27 Fixed Ladder Standards. Hand and foot forces were recorded for six male and six female subjects as they ascended and descended the ladder. Although significant inter and intra subject climbing styles were observed for rung and rail climbing, it is still possible to draw important conclusions about the effects of climbing style, ladder pitch and bank, and carrying objects up and down ladders. Most of the work to ascend and descend the ladder is performed with the lower limbs. The hands must constantly exert force to prevent falling from a vertical ladder. Less hand force was exerted on the rails than on the rungs. Hand placement during rung climbing is constrained by rung spacing, while hand placement during rail climbing is determined by climber preference. It can be shown that required hand force is related to vertical hand placement and body center of mass position. Even though less resultant hand force was exerted during rail climb, the lateral component of hand force was greater for rail climbing than for rung climbing. Lateral hand forces may tend to destabilize the climber from the center of the ladder. Tilting the ladder forward reduces hand forces, which is consistent with the biomechanics of climbing and with previous studies. Tilting the ladder laterally did not significantly affect peak hand and foot forces, but it did affect the observed load/unload cycle time for hand and foot climbing movements.

The spatial dynamics of crop and ground active predatory arthropods and their aphid prey in winter wheat

The distribution of aphid predators within arable fields has been previously examined using pitfall traps. With this technique predominantly larger invertebrate species are captured, especially Carabidae, but the technique provides no estimate of density unless mark-recapture is used. However, many other numerically important aphid predators occur in arable fields and relatively little is known about their distribution patterns nor whether they exhibit a density-dependent response to patches of cereal aphids. Identification of the most effective predators can allow management practices to be developed accordingly. In this study, the distribution of cereal aphids and their predators was examined by suction sampling within a field of winter wheat in Devon, UK, along with visual estimates of weed patchiness. Sampling was conducted on four occasions in 1999 across a grid of 128 sample locations. The distribution of 11 predatory taxa from the Carabidae, Staphylinidae and Linyphiidae was examined. Additionally, the total number of aphid predators and a predation index were used in these analyses. Carabid adults and larvae, along with staphylinid larvae showed the strongest aggregation into patches and the most temporal stability in their distribution. Other taxa had more ephemeral distributions as did the cereal aphids. The distribution of carabid larvae was disassociated from the distribution of cereal aphids for the first two sampling occasions indicating biocontrol was occurring. Other predatory groups showed both association and disassociation. Carabid larvae, Bathyphantes and total numbers of Linyphiidae showed a strong correlation with weed cover for two of the sample dates. Cereal aphids were disassociated from weed cover on three sampling occasions.

Stature, age, and gender effects on reach motion postures

The rapid adoption of software to simulate human reach motions in the design of vehicle interiors and manufacturing and office workstations has required a sophisticated understanding of human motions. This paper describes how more than 3,000 right-arm reaching motions of a diverse group of participants were captured and statistically modeled. The results demonstrate that stature and age have a larger effect than does gender on reach motion postures for motions chosen by the participants while reaching to targets placed throughout a typical automobile interior. We propose that these methods, models, and results can assist the further development of human motion simulation software for ergonomic purposes, such as for the design or evaluation of vehicle interiors or industrial workplaces, to ensure that various population groups are physically accommodated.

Relatives' perceptions of role change, social support and stress after traumatic brain injury

There is general agreement between researchers and clinicians alike that relatives of people with head injuries experience heightened stress as a result of the injury and its consequences. In the present study a single structured interview, including both verbally administered and written response questionnaires, was completed by 18 parents and 11 partners. Measures included the Daily Hassles and Uplifts Scale, the Arizona Social Support Interview Schedule and questions regarding role change and health problems. The combined parents and partners group indicated that they experienced moderate levels of stress and role change. A relatively small proportion of participants reported experiencing health problems. Partners indicated a slightly higher degree of stress and a greater degree of role change than parents, and a larger proportion of partners indicated the presence of health problems. Qualitative differences between the two groups were found in terms of sources of stress. There was little quantitative or qualitative difference between the two groups in sources, utilization of and satisfaction with social support. Positive correlations were found between stress and role change and stress and health problems.

Steroid hormones as mediators of neural plasticity

Steroid and thyroid hormone receptors are expressed in the developing brain and persist throughout adult life. They mediate a variety of effects on the brain, ranging from developmental effects of thyroid hormone and the process of sexual differentiation to the cyclic changes during reproductive cycles in adult female animals. This review summarizes data from the author's laboratory on three topics: (1) actions of extradiol and progesterone on the ventromedial nucleus of the hypothalamus in adult female and male rats, showing both the cyclicity and the consequences of brain sexual differentiation; (2) actions of estradiol on the cholinergic neurons of the basal forebrain of the female and male rat, reflecting the plasticity of the adult cholinergic system as well as sex differences which are developmentally programmed; and (3) diverse actions of estrogens, thyroid hormone and glucocorticoids on the morphology of hippocampal neurons. The review concludes by discussing the interactions between "organizational" (i.e. developmental) effects and the "activational" effects of steroids on the mature nervous system in relation to the environmental control of brain gene expression.

The strong binding of luzopeptin to DNA

The effect of luzopeptin on the mobility of DNA in polyacrylamide gels has been determined. Experiments on a mixture of DNA fragments of various lengths have shown that the drug does not form intermolecular cross-links. Gel analysis of complexes of the drug with short DNA fragments (15-35 base pairs) reveals a ladder of discrete bands in which each band appears to correspond to the addition of a further drug molecule. The results suggest that luzopeptin binds very strongly to DNA, occupying about four base pairs and displays little or no sequence selectivity. Luzopeptin renders certain adenine residues hyperreactive to diethylpyrocarbonate, these occur in different positions to those affected by echinomycin.

A technique for assessment of torso kinesiology

A technique is described for monitoring and analysis of the angular displacement of the human torso. The technique is based on the use of miniature electromechanical inclinometers and video recording. The system was developed for continuous measurement of the angular displacement of spinal segments in the sagittal plane during all stages of lifting. Angular displacements of the cervical, thoracic and lumbar regions were obtained from a dynamic lifting case study using a digital processing system. The geometrical changes of the torso during five prescribed stages were measured. The system revealed good accuracy with high correlation coefficient scores for a wide range of lifting tasks in a comparative laboratory study. This paper describes the monitoring technique; the system's advantages, disadvantages and measuring accuracy are discussed.

Deoxycytidylate hydroxymethylase: purification, properties, and the role of a thiol group in catalysis

Deoxycytidylate (dCMP) hydroxymethylase from Escherichia coli infected with a T-4 bacteriophage amber mutant has been purified to homogeneity. It is a dimer with a subunit molecular weight of 28,000. Chemical modification of the homogeneous enzyme with N-ethylmaleimide (NEM) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) leads to complete loss of enzyme activity. dCMP can protect the enzyme against NEM inactivation, but the dihydrofolate analogues methotrexate and aminopterin alone do not afford similar protection. Compared to dCMP alone, dCMP plus either methotrexate or aminopterin greatly enhances protection against NEM inactivation. DTNB inactivation is reversed by dithiothreitol. For both reagents, inactivation kinetics obey second-order kinetics. NEM inactivation is pH dependent with a pKa for a required thiol group of 9.15 +/- 0.11. Complete enzyme inactivation by both reagents involves the modification of one thiol group per mole of dimeric enzyme. There are two thiol groups in the totally denatured enzyme modified by either NEM or DTNB. Kinetic analysis of NEM inactivation cannot distinguish between these two groups; however, with DTNB kinetic analysis of 2-nitro-5-thiobenzoate release shows that enzyme inactivation is due to the modification of one fast-reacting thiol followed by the modification of a second group that reacts about 5-6-fold more slowly. In the presence of methotrexate, the stoichiometry of dCMP binding to the dimeric enzyme is 1:1 and depends upon a reduced thiol group. It appears that the two equally sized subunits are arranged asymmetrically, resulting in one thiol-containing active site per mole of dimeric enzyme.

Genetic controls over activities of tyrosinase and dopachrome conversion factor in murine melanocytes

We evaluated the three catalytic activities of tyrosinase and one activity of dopachrome conversion factor (DCF) in extracts made from skins of 6-day-old yellow and nonyellow mice. At least one of the catalytic activities of tyrosinase and of DCF correlate with the color of pigment being produced in the hair follicles of the mice. We use these data to evaluate existing hypotheses about the mechanism of the interacting genetic controls over melanogenesis.

Laser differential light scattering bioassays for selected antitumor agents

Bioassay methods for actinomycin D, 6-thioguanine, and adriamycin which utilize laser light scattering from suspensions of drug-sensitive bacteria have been developed. In 3 hours, serum and urine levels of the 3 drugs can be reproducibily measured. A sample volume of 0.1 ml may be assayed with a precision of +/- 10%. The linear response range for actinomycin D was 0.03 to 3.0 microgram/ml. For 6-thioguanine and adriamycin the linear responses range was 0.03 to 10.0 and 0.25 to 10.0 microgram/ml, respectively. Thetively. The present studies further confirm the general utility of differential light scattering as a rapid and inexpensive assay procedure of broad application.

Laser light scattering bioassay for 1-beta-D-arabinofuranosylcytosine (ARA-C, NSC-63878)

A bioassay method for the estimation of ara-C in biological samples which utilizes laser light scattering from suspensions of drug-sensitive bacteria has been developed. The species employed in the assay was Streptococcus faecium var. durans resistant to methotrexate and 6-mercaptopurine. In less than four hours, serum and urine levels of ara-C can be reproducibly measured using the method. A sample volume of 0.1 ml containing 30 ng/ml may be assayed with a precision of +/-10 percent. The present studies further confirm the utility of the method as a rapid and relatively inexpensive assay methodology of broad application. Time variations of drug serum levels and urinary excretion rates in dogs are compared via the differential light scattering (DLS) assay, standard disc diffusion assay, and radiosotopic assay. The results obtained by the various methods are in excellent agreement.

Biological assay of streptonigrin (NSC 45383) in body fluids and tissues of mice

Streptonigrin, a quinone antitumor antibiotic, has been reported to be effective in human trials. A sensitive and precise microbiological assay for the determination of distribution and concentrations of streptonigrin in the body fluids and tissues of treated mice has been developed in an attempt to supplement successful clinical application of this drug.

Microbiological assay for estimating concentrations of DL-alanosine in mouse tissue

A sensitive, precise microbiological assay was developed for the determination of tissue distribution of dl-alanosine, a new antitumor agent.

Bleomycin, and antitumor antibiotic: improved microbiological assay and tissue distribution studies in normal mice

A microbiological assay was developed for bleomycin, an antitumor antibiotic reported to be active in human trials. The assay bacterium was a strain of Escherichia coli which is resistant to ethionine. Studies revealed relatively high concentrations of bleomycin in the blood and urine of mice after a single dose, < 0.33 ld(10), injected intraperitoneally.

Chromomycin A 3 , an antitumor antibiotic: tissue distribution studies in mice as measured by microbial assay

A microbiological assay has been developed for chromomycin A(3), an antitumor antibiotic showing promise in human trials. The assay bacterium is a derived strain of Streptococcus faecalis resistant to methotrexate. Studies with mice revealed that relatively high concentrations of this antibiotic were maintained in the blood, kidneys, and liver of mice after a single-dose intraperitoneal injection of the drug.

Microbiological assay and tissue distribution of 5-diazouracil in mice

A sensitive, precise microbiological assay has been developed for the determination of tissue distribution of 5-diazouracil, a potential antitumor and antimicrobial agent.

Microbiological assay and tissue distribution of beta-thioguanine deoxyriboside in mice

A sensitive, precise microbiological assay has been developed for the determination of tissue distribution of beta-thioguanine deoxyriboside, a new antitumor agent.

Pseudourea, 2,2'-(9,10-anthrylenedimethylene) bis-(2-thio-, dihydrochloride) dihydrate: microbiological assay and tissue distribution studies in mice

A microbiological assay for pseudourea, 2,2'-(9,10-anthrylenedimethylene)bis-(2-thio-, dihydrochloride) dihydrate (NSC 56054), a new anticancer agent, has been developed and tissue distribution studies in mice have been performed.

5-azacytidine: microbiological assay in mouse blood

A 6-chloropurine-resistant strain of Escherichia coli has been used to develop a microbiological assay for the estimation of 5-azacytidine distribution in mouse tissues.