Spit, Disgust, and Parasite Stress Theory: A Message Experiment

Public health interventions targeting coughing and spitting during the Tuberculosis and 1918 flu epidemics were largely successful. Specifically, public health officials' messaging framed the behavior of spitting as repulsive and endangering to others, prompting an elicitation of disgust. Anti-spitting campaigns - messaging that focuses on the threat of spit or sputum - have long been common during pandemics and manifested once again to combat the spread of COVID-19. Yet, few scholars have theorized if and how anti-spitting campaigns function to change behavior. One possibility is parasite stress theory, which posits that human behavior is driven by a desire to avoid pathogenic threats like spit. The application of these types of disgust appeals in public health messaging remains understudied and warrants exploration. To test the applicability of the parasite stress theory, our message experiment with US adults (N = 488) examined reactions to anti-spit messages that varied in visual disgust (low and high). For more highly educated respondents, the high disgust appeal directly decreased spitting intentions, and this relationship was stronger for individuals with higher levels of pathogen and moral disgust. Given the importance of public messaging during pandemics, future research should continue to examine the efficacy and theoretical underpinnings of specific disgust appeals.

Explicitness, disgust, and safe sex behavior: A message experiment with U.S. adults

Sexual health risks are challenging to communicate given the potential negative reactions of target audiences to explicit language. Grounded in research on pathogen avoidance, the current study examined the impact of varying levels of explicit language on message perceptions and safe sex behavioral intentions. U.S. adults (N = 498) were randomly assigned to view messages detailing pandemic safe sexual behavior that contained either low or high levels of explicit language. High explicit language significantly increased perceived disgust which also indirectly linked high explicit language with increased intentions to engage in safe sex behavior. Individual difference variables moderated the impact of message explicitness; dispositional hygiene disgust moderated the impact of high explicit, hygiene-focused messages on safe sex intentions. Those with relatively low levels of dispositional disgust were more positively impacted by explicit language. The results suggest the value of increased message explicitness for sexual health communication and have implications for pathogen avoidance behaviors, the behavioral immune system, and dispositional and affective forms of disgust.

The extracellular matrix molecule tenascin-R and its HNK-1 carbohydrate modulate perisomatic inhibition and long-term potentiation in the CA1 region of the hippocampus

Perisomatic inhibition of pyramidal cells regulates efferent signalling from the hippocampus. The striking presence of HNK-1, a carbohydrate expressed by neural adhesion molecules, on perisomatic interneurons and around somata of CA1 pyramidal neurons led us to apply monoclonal HNK-1 antibodies to acute murine hippocampal slices. Injection of these antibodies decreased GABAA receptor-mediated perisomatic inhibitory postsynaptic currents (pIPSCs) but did not affect dendritic IPSCs or excitatory postsynaptic currents. The decrease in the mean amplitude of evoked pIPSCs by HNK-1 antibodies was accompanied by an increase in the coefficient of variation of pIPSC amplitude, number of failures and changes in frequency but not amplitude of miniature IPSCs, suggesting that HNK-1 antibodies reduced efficacy of evoked GABA release. HNK-1 antibodies did not affect pIPSCs in knock-out mice deficient in the extracellular matrix molecule tenascin-R which carries the HNK-1 carbohydrate as analysed by immunoblotting in synaptosomal fractions prepared from the CA1 region of the hippocampus. For control, HNK-1 antibody was applied to acute sections of mice deficient in the neural cell adhesion molecule NCAM, another potential carrier of HNK-1, and resulted in decrease of pIPSCs as observed in wild-type mice. Reduction in perisomatic inhibition is expected to promote induction of long-term potentiation (LTP) by increasing the level of depolarization during theta-burst stimulation. Indeed, LTP was increased by HNK-1 antibody applied before stimulation. Moreover, LTP was reduced by an HNK-1 peptide mimic, but not control peptide. These results provide first evidence that tenascin-R and its associated HNK-1 carbohydrate modulate perisomatic inhibition and synaptic plasticity in the hippocampus.

Animal experiments for the evaluation of laserspectroscopy in the fetus during labor

Laserspectroscopy with near-infrared light is newly available for clinical application. The equipment consists of a near-infrared data collection unit (NIRDCU) and a personal computer. Emission of laser light at wavelengths of 775, 805, 845 and 904 nm is provided by the four laser diodes of the NIRDCU. By analyzing changes of optical density during laser radiation, information is obtained regarding the intracellular redox state and relative changes of blood volume. During measurement with the system on the fetal scalp during delivery we were able to get a first impression of the method's potential. While the application of the laser sensors is still cumbersome, signals providing information of the relative changes of hemoglobin concentration, relative changes of blood volume and cytochrome aa3 seems achievable. Laserspectrophotometric monitors may become safe, low cost and portable instruments for the non-invasive assessment of the biochemical and biophysical status in the fetus.

[Laser spectroscopy--a new procedure in fetal monitoring]

Monitors for laser spectroscopy are available as an additional tool for foetal surveillance. Using this technique, continuous and non-invasive registration of four biochemical parameters (HbO2, HbR, blood volume and cytochrome aa3) can be performed. The calculation is based on the optical density after irradiation of the biological sample with pulsed laser light in the near-infrared range (755, 805, 845, 904 nm). We evaluated the new technique in a clinical trial of 20 patients. The application of the laser sensor was performed, using a modified amnioscope. During prenatal tracings in cases with suspect CTG patterns, hypoxia was not verified. In cases without late decelerations a decrease of the cytochrome aa3 signal was observed in less than 1%. During intrapartual measurements, near-infrared signals were compared with the result of the PO2 measurement in foetal blood analysis. We found a significant correlation for HbO2 and cytochrome aa3 with a correlation coefficient of r = 0.96 respectively r = 0.94. We conclude, that laser spectroscopy will potentially be of benefit for foetal monitoring as it might provide a basis for differentiation between foetuses at risk and non-hazardous cases.

[Continuous transcutaneous PCO2 measurement and laser spectroscopy for fetal monitoring in 3d degree atrioventricular block]

Obstetrical management in case of foetal third-degree AV block has been to date mainly via primary abdominal section, the indication being partly the foetal condition and partly also unsatisfactory childbirth monitoring. The article describes a childbirth associated with AV block, monitoring being effected by continuous measurement of the transcutaneous partial carbon dioxide pressure (tcpCO2) and via laser spectroscopy. Prenatal diagnostics and indications for vaginal delivery are also described. Updated knowledge on the pathogenesis of foetal AV block is presented.

[Effects of mellitic acid on matrix-induced, ectopic osteogenesis in the rat]

Similar to diphosphonates mellitic acid is characterized by its high affinity to Calcium-phosphate-minerals. Mellitic acid inhibits the crystallization of hydroxyapatite in vitro and in vivo. Local application of mellitic acid (concentration 1 mmol/l) proved not to impair osteoinduction and development of nature bone in the matrixinduced ectopic osteogenesis. But in the course of osteogenesis prominent masses of cartilage developed. Higher local concentrations of mellitic acid may be efficient in the therapy of ectopic ossification, but also may be accompanied by formation of crystal deposition.