Reality distortion is related to the structure of the salience network in schizophrenia

BACKGROUND

An intrinsic cerebral network comprising the anterior cingulate and anterior insula (the salience network) is considered to play an important role in salience detection in healthy volunteers. Aberrant salience has been proposed as an important mechanism in the production of psychotic symptoms such as delusions and hallucinations (reality distortion). We investigated whether structural deficits in the salience network are associated with the reality distortion seen in schizophrenia.

METHOD

A sample of 57 patients in a clinically stable state of schizophrenia and 41 controls were studied with high-resolution magnetic resonance imaging.

RESULTS

Bilateral volume reduction was seen in the anterior cingulate and anterior insula in patients with schizophrenia. Reduced volume in the two left-sided regions of the salience network was significantly correlated with the severity of reality distortion.

CONCLUSIONS

These findings suggest that a deficit of grey matter in the salience network leads to an impaired attribution of salience to stimuli that is associated with delusions and hallucinations in schizophrenia.

Gender differentiation of the chemoreflex during growth at high altitude: functional and neurochemical studies

The effect of chronic hypoxia on gender differences in physiology and neurochemistry of chemosensory pathways was studied in prepubertal and adult rats living at sea level (SL; Lyon, France) or at high altitude (HA; La Paz, Bolivia, 3,600 m). HA adult rats had higher hematocrit (Ht%), Hb concentration, resting ventilatory rate (Ve(100)), and higher tyrosine hydroxylase (TH) activity in carotid bodies (CB) than SL animals. At HA and SL, adult females had lower Ht% (46.0 +/- 0.8 vs. 50.4 +/- 0.6% at HA, P < 0.05 and 43.8 +/- 0.9 vs. 47.1 +/- 0.8% at SL, P < 0.05) and Hb (16.1 +/- 0.3 vs. 17.7 +/- 0.2 g/dl at HA, P < 0.05 and 14.5 +/- 0.3 vs. 15.6 +/- 0.1 g/dl at SL, P < 0.05) than males. Females had higher Ve(100) [170 +/- 19 vs. 109 +/- 7 ml. min(-1). 100 g(-1) at HA, P < 0.05 and 50 +/- 3 vs. 40 +/- 2 ml. min(-1). 100 g(-1) at SL, not significant (NS)] and lower CB-TH activity (1.40 +/- 0.2 vs. 3.87 +/- 0.6 pmol/20 min at HA, P < 0.05 and 0.52 +/- 0.1 vs. 0.68 +/- 0.1 pmol/20 min at SL; NS) than males at HA only. The onset of hypoxic ventilatory response during development was delayed at HA. Prepubertal HA females had higher Ve(100) than males (2 wk old, +47%) and higher CB-TH activity (3 wk old, +51%). Medullary noradrenergic groups were sex dimorphic during development at SL. Rats raised at HA had a drop of TH activity between the second and the third postnatal week in all medullary groups. In conclusion, our data support the hypothesis that the CB is the major site for sexual differentiation of the ventilatory control. Ventilatory differences appeared before puberty, and the animals bred at HA had profound alterations in the developmental process of the chemoreflex and its neural pathways. Some of these alterations are under dependence of the sex of the animal, and there is an important interaction between gender and the hypoxic environmental condition during the developmental period.

Developmental profile of cholinergic and purinergic traits and receptors in peripheral chemoreflex pathway in cats

This study describes the developmental profile of specific aspects of cholinergic and purinergic neurotransmission in key organs of the peripheral chemoreflex: the carotid body (CB), petrosal ganglion (PG) and superior cervical ganglion (SCG). Using real time RT-PCR and Western blot analyses, we assessed both mRNA and protein expression levels for choline-acetyl-transferase (ChAT), nicotinic receptor (subunits alpha3, alpha4, alpha7, and beta2), ATP and purinergic receptors (P2X2 and P2X3). These analyses were performed on tissue from 1- and 15-day-old, 2-month-old, and adult cats. During development, ChAT protein expression level increased slightly in CB; however, this increase was more important in PG and SCG. In CB, mRNA level for alpha4 nicotinic receptor subunit decreased during development (90% higher in 1-day-old cats than in adults). In the PG, mRNA level for beta2 nicotinic receptor subunit increased during development (80% higher in adults than in 1-day-old cats). In SCG, mRNA for alpha7 nicotinic receptor levels increased (400% higher in adults vs. 1-day-old cats). Conversely, P2X2 receptor protein level was not altered during development in CB and decreased slightly in PG; a similar pattern was observed for the P2X3 receptor. Our findings suggest that in cats, age-related changes in cholinergic and purinergic systems (such as physiological expression of receptor function) are significant within the afferent chemoreceptor pathway and likely contribute to the temporal changes of O2-chemosensitivity during development.

Raptor hematology and chemistry evaluation

Hematologic and biochemical evaluation of raptor blood samples is discussed to guide the practitioner in the diagnosis of disease. Species and age variation in the raptors in response to the laboratory values is also addressed.

Prenatal blockade of estradiol synthesis impairs respiratory and metabolic responses to hypoxia in newborn and adult rats

We tested the hypothesis that estradiol modifies respiratory control in pregnant rats and participates in the development of respiratory chemoreflexes in fetuses. Pregnant rats (n = 12) received daily subcutaneous injections of vehicle (Veh, n = 6) or 4-androsten-4-ol-3,17-dione acetate (ATD; inhibitor of estradiol synthesis; n = 6; 5 mg/day in vehicle) from gestational day 16 (G16) to delivery. Baseline ventilation (whole body plethysmography) and metabolic rate [oxygen consumption (Vo(2))] were determined at G14 and G20, in pups [on postnatal day 3 (P3) and P20] and in adult rats (on P70) born to Veh- or ATD-treated mothers. Hypoxic chemoreflex was assessed in P3 rats by acute exposure to 60% O(2) and in P20 or P70 rats by moderate hypoxia (12% O(2), 30 min). ATD treatment reduced circulating estradiol in pregnant dams at G20 without producing changes in the circulating level of estradiol precursors (testosterone and androstenedione). ATD-treated dams showed impaired respiratory adjustment to late gestation. Pups born to ATD mothers had higher resting Vo(2) (+23% at P3, +21% at P20), respiratory frequency (+15% at P3, +12% at P20), and minute ventilation (+11% at P3, +18% at P20) than pups from Veh mothers. Respiratory decrease during acute hyperoxic exposure at P3 was -9.7% in Veh (P < 0.05 vs. room air) and only -2.6% (P = not significant) in ATD pups. In P20 ATD rats, hypoxic ventilatory response was attenuated compared with Veh. In P20 and P70 rats, the drop of Vo(2) in hypoxia (-31% in P70, P < 0.0001) was not observed in ATD rats. We conclude that estradiol secreted during late gestation is necessary for respiratory adjustment to pregnancy and is required for adequate development of respiratory and metabolic control in the offspring.

Temporal Trends in Suicide Methods Among Adolescents in the US

This cross-sectional study evaluates the temporal trends in suicide methods among US adolescents, with variation by sex and race.

Developmental pattern of M1 and M2 muscarinic gene expression and receptor levels in cat carotid body, petrosal and superior cervical ganglion

Using real-time reverse transcriptase polymerase chain reaction, Northern blot, and Western blot analyses, we evaluated the developmental pattern of mRNA and protein expression level of muscarinic M1 and M2 receptors in the carotid body, petrosal ganglion and superior cervical ganglion of 1-day, 15-day, 2-month-old and adult cats. mRNA expression and protein levels of tyrosine hydroxylase, the rate limiting enzyme for dopamine synthesis, were also assessed. Carotid body M1 receptor mRNA, increased significantly by approximately 100% and 300% in 2-month and adult vs. 1- and 15-day-old cats, but protein level decreased gradually being approximately 50% lower compared with 1-day-old cats. In the petrosal ganglion, muscarinic M1 receptor mRNA level was higher in 15-day-old cats vs. 1-day-old, 2-month-old and adult cats and protein levels were about 30% lower than in 1- and 15-day-old cats. In the superior cervical ganglion, muscarinic M1 receptor mRNA was approximately 50% and 80% higher in 2-month-old and adult cats than 1- and 15-day-old, but no changes in the protein level except in 15-day-old cats which was approximately 40% higher than 1-day-old. There was no change of muscarinic M2 receptor mRNA or protein level in the carotid body or petrosal ganglion. However, in the superior cervical ganglion, the significant increase of mRNA of 30% and 50% in 2-month-olds and adults, respectively was not associated with an increase in receptor protein. Tyrosine hydroxylase mRNA and protein level decreased significantly with age in the carotid body and petrosal ganglion. In the superior cervical ganglion, the age dependent increase in tyrosine hydroxylase mRNA was not associated with any changes in the protein level. These results show that the expression of muscarinic M1 and M2 receptors are age and organ-dependent in cats. Consequently, these changes may modulate chemosensory activity during development since muscarinic M1 receptor is predominantly involved in postsynaptic chemosensory activity, while muscarinic M2 receptor modulates acetylcholine and dopamine release from chemosensitive cells.

Dexamethasone's influence on tyrosine hydroxylase activity in the chemoreflex pathway and on the hypoxic ventilatory response

Catecholamines have been implicated in neuromodulation of peripheral chemosensitivity and central respiratory mechanisms. Because glucocorticoids can affect catecholamine metabolism in the carotid body and brainstem, this study explored the possibility that, in rats, dexamethasone or adrenalectomy affects catecholamine biosynthesis in carotid body chemoreceptors and the medullary areas (A2C2, A5, A6, A7) involved in the chemoreflex pathway and the hypoxic ventilatory response (HVR). One dexamethasone injection (1 mg/kg body wt.) stimulated tyrosine hydroxylase activity in the carotid body and had no effect in brainstem catecholamine areas, while HVR was reduced. Chronic dexamethasone (1 mg/kg body wt. daily for 10 days) had a stimulatory influence on tyrosine hydroxylase activity in the carotid body and an inhibitory effect on A2C2, A5 and A7 cell groups. Breathing pattern, but not HVR, was altered. Adrenalectomy elicited an increase in tyrosine hydroxylase activity in A2C2, which was accompanied by a decreased respiratory frequency in hypoxia. The data show that glucocorticoids have differential effects on catecholamine biosynthesis in peripheral and central structures involved in the chemoreflex pathway. Depending on the treatment, the neurochemical changes were accompanied by alterations of HVR or the breathing pattern, which are consistent with a neuromodulating influence of catecholamines on peripheral chemosensory inputs or the central respiratory network.

Antagonism of progesterone receptor suppresses carotid body responses to hypoxia and nicotine in rat pups

We tested the hypothesis that antagonism of progesterone receptor (PR) in newborn rats alters carotid body and respiratory responses to hypoxia and nicotinic receptor agonists. Rats were treated with the PR antagonist mifepristone (daily oral gavage 40 μg/g/d) or vehicle between postnatal days 3 and 15. In 11-14-day-old rats, we used in vitro carotid body/carotid sinus nerve preparation and whole body plethysmography to assess the carotid body and ventilatory responses to hypoxia (65 mmHg in vitro, 10% O2 in vivo) and to nicotinic receptor agonists (as an excitatory modulator of carotid body activity-nicotine 100 μM for in vitro studies, and epibatidine 5 μg/kg, i.p., which mainly acts on peripheral nicotinic receptors, for in vivo studies). The carotid body responses to hypoxia and nicotine were drastically reduced by mifepristone. Compared with vehicle, mifepristone-treated rats had a reduced body weight. The ventilatory response to epibatidine was attenuated; however, the hypoxic ventilatory response was similar between vehicle and mifepristone-treated pups. Immunohistochemical staining revealed that mifepristone treatment did not change carotid body morphology. We conclude that PR activity is a critical factor ensuring proper carotid body function in newborn rats.

Infectious and parasitic diseases of captive passerines

The small passerines, canaries and finches, are social birds often bred and housed in flock aviaries. The aviary may be a mixed aviary housing different species or a breeding aviary concentrating on a single species. Multiple birds in contact with each other provide the means by which infectious disease can spread. Dietary and husbandry requirements vary for the species of passerines housed and can also influence disease outbreaks when they are less than optimal. Stress factors, including nutritional, husbandry (overcrowding, aviary maintenance), breeding, and the introduction of new birds, may play a significant role in disease outbreaks. An overview of viral, bacterial, fungal, and parasitic issues affecting passerines housed in aviaries will be addressed.

Suprabrow minicraniotomy for suprasellar tumours

We present our experience with suprabow minicraniotomy in the excision of 18 suprasellar tumours between May 2001 and September 2003. There were 14 females and four males with ages ranging from 7 to 59 years. The tumours included one epidermoid cyst, 10 meningiomas, five craniopharyngiomas and two optico-chiasmatico-hypothalamic (OCHG) gliomas. The size of the one-piece craniotomy was about 2.5 cm. Both OCHGs were biopsied; one craniopharyngioma was totally excised, the remaining craniopharyngiomas and epidermoid cyst were subtotally excised. Four meningiomas were radically excised and six were subtotally removed. The patient with a craniopharyngioma that had a radical excision died of hypothalamic dysfunction. One patient developed a postoperative meningitis and subsequent hydrocephalus requiring a shunt. The other patients did well and the cosmetic result was excellent in all cases. This basal approach through a small craniotomy provided good surgical access to suprasellar tumours with minimal brain retraction.

Perinatal steroid exposure and respiratory control during early postnatal life

Numerous factors involved in general homeostasis are able to modulate respiratory motor output. These include placental-derived steroids, which are necessary for maternal physiological adjustments during gestation, including respiratory stimulation. Despite the fact that these hormones exert potent effects on neural development in the fetus, the hypothesis of a developmental control of the neural respiratory network by placental-derived steroids has been approached experimentally only recently. The objective of this review is to summarize the role and mode of action of placental steroids on respiratory control in adult mammals and highlight the potential pathways by which such steroids are supplied to the developing fetus. Additionally, we present recent results showing that the beta estradiol and progesterone receptors are expressed in the carotid body of newborn male rats, thus supporting the hypothesis of receptor-mediated effect of estradiol and progesterone on carotid bodies.

Emergency care of raptors

Emergency care of raptors often requires extensive diagnostics and therapeutic regimens to stabilize and support the ill or injured raptor. Whether falconry birds, educational birds, or raptors from the wild are presented, various medical conditions must be addressed to help guide the practitioner toward a complete recovery for the raptor.

Introducing Adelaide dental students to a problem-based learning curriculum

A course designed to introduce new students to a problem-based learning (PBL) curriculum in dentistry at the University of Adelaide is described. Australian students are admitted to the Adelaide dental course either directly from school (SL) or after one or more years of tertiary education (TT). The admissions process is designed to select academically able students who will flourish in a problem-based environment. Some international students (INT) are also selected through a modified admissions process. A 9-item questionnaire derived from frequently-asked questions from previous years was administered to the new students at the beginning and at the end of the introductory course, and each individual's responses before and after the course were compared. There was an increased number of positive responses (significant at P < 0.05 to 7 of the 9 items) after the course. Although the course appeared to be effective in familiarising new students with a PBL curriculum, many students were still uncertain about two items which commonly provoke anxiety, namely how to decide when to stop researching a topic, and how to balance group and solo learning.

Raptor medicine: an approach to wild, falconry, and educational birds of prey

A veterinarian receiving birds of prey (raptors) will often be presented with wild, educational, or falconry raptors. Raptors trained for the sport of falconry and educational raptors are handled in a precise manner, often differently from the wild raptors. It is imperative for veterinarians treating raptors to be familiar with the equipment and terminology used by the individuals caring for these birds. The hospital staff must also be educated to handle the raptors properly, both wild and tame, because differences do exist between the approaches. Raptor medicine requires a thorough diagnostic work-up and aggressive therapeutic plan to help ensure a fast and complete recovery.

Sleep deprivation and suicide risk among minoritized US adolescents

OBJECTIVES

To assess (1) the prevalence of suicide ideation/behavior among adolescents with short sleep by race/ethnicity and (2) the association between sleep duration and suicidal ideation and behavior among American youth by race/ethnicity from 2007 to 2019.

METHODS

Data were drawn from the Youth Risk Behavior Surveillance System (YRBSS). Logistic regression analyses were used to assess the relationship between sleep duration and suicidal ideation/behavior.

RESULTS

Overall, suicide ideation/behavior increased among U.S. adolescents of all racial groups from 2007 to 2019. Adjusting for race/ethnicity, sexual identity, age, sex, substance use, trauma, and bullying, those with short sleep had approximately twice the odds [OR: 1.92 (95% CI: 1.65, 2.23)] of suicide ideation/consideration compared to those with long sleep. Stratified analyses indicated that Black students with short sleep had higher odds of making a suicide plan (OR = 1.51, 95% C.I.: 1.27, 1.79) compared with Black students with long sleep. A similar pattern was observed across other racial/ethnic groups (e.g., Hispanic: (OR = 1.74, 95% C.I.: 1.53, 1.97).

CONCLUSION

Emphasis on suicide interventions is of the essence, especially with increasing rates. Sleep duration significantly predicts suicide risk among all adolescents. Additional research is needed to assess factors that predict suicide among minoritized adolescents, specifically Black and Hispanic adolescents.

Racial inequities in homicide rates and homicide methods among Black and White women aged 25-44 years in the USA, 1999-2020: a cross-sectional time series study

BACKGROUND

In the USA, Black women aged 25-44 years are disproportionately murdered compared with their White counterparts. Despite ongoing efforts to reduce racial and structural inequities, the result of these efforts remains unclear, particularly in light of the COVID-19 pandemic.

METHODS

This study examined a cross-sectional time series of homicide death rates, by race, from the Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research system. We included data for women aged 25-44 years between 1999 and 2020 among 30 states in the USA. Homicide death was classified using underlying cause and multiple cause of death codes; mortality rates were calculated per 100 000 based on US Census Bureau population sizes. Homicide methods were classified as firearm, cutting or piercing, and other. Firearm homicides were compared with other homicides with logistic regression including covariates of race, time, and their interaction. We report odds ratios and 95% CIs.

FINDINGS

In 2020, the homicide rate among Black women was 11·6 per 100 000, compared with 3 per 100 000 among White women. This inequity has persisted over time and is virtually unchanged since 1999. Homicide inequities vary across US states; in 11 states, racial inequities have increased since 1999. The racial inequity was greatest in Wisconsin, where in 2019-20, Black women aged 25-44 years were 20 times more likely to die by homicide than White women. Homicide by firearm is increasing in frequency; women in the USA had 2·44 (95% CI 2·14-2·78) times the odds of homicide involving firearms in 2019-20 compared with 1999-2003. Firearm homicide deaths are disproportionately concentrated among Black women in every region in the USA.

INTERPRETATION

Our findings suggest that there is an urgent need to address homicide inequities among Black and White women in the USA. Enacting federal legislation that reduces gun access is a crucial step. Policy makers must address long-standing structural factors that underpin elevated gun violence by implementing sustainable wealth-building opportunities; developing desegregated, mixed income and affordable housing; and increasing green spaces in communities where Black women largely reside.

FUNDING

National Institute of Mental Health of the National Institutes of Health.

Growth and optical, thermal, mechanical and surface morphology studies of semiorganic nonlinear optical material: Dichlorobis (l-proline) zinc (II) crystal

The organometallic nonlinear optical material Dichlorobis (l-proline) zinc (II) (DCBPZ) was crystallized using solution growth technique. XRD data reveal that the grown crystal belongs to orthorhombic system with space group P212121. The crystals were characterized using UV-vis-NIR, FTIR and NMR spectral studies, SEM-EDAX analysis and Atomic force microscopy (AFM), thermal and microhardness studies. Photoconductivity measurements were made to understand the response of the grown material to the visible light. The SHG efficiency of DCBPZ was also measured using Kurtz and Perry powder technique. It is observed that the NLO activity of DCBPZ is found to be twice that of KDP due to improved linear and nonlinear optical properties of the material.

Increasing inequality in childhood obesity in primary schools in a northern English town

OBJECTIVE

To undertake an analysis of National Child Measurement Programme (NCMP) data to quantify the obesity prevalence gap over time between children in primary schools in the most and least deprived areas of Doncaster.

STUDY DESIGN

The research design for this study was retrospective quantitative analysis of secondary data.

METHODS

The study undertook secondary analysis of NCMP data on obesity prevalence in children in Reception Year and Year 6 in primary schools in Doncaster for the period 2006-2007 to 2014-2015. Data were combined into three 3-year periods (2006-2007 to 2008-2009; 2009-2010 to 2011-2012; and 2012-2013 to 2014-2015), and schools were grouped by deprivation based on the national Indices of Multiple Deprivation 2015. Analysis was undertaken to assess whether there is a difference in obesity prevalence for Reception Year and Year 6 children in schools in the most deprived areas compared with the least deprived (prevalence gap), over time.

RESULTS

The difference in obesity prevalence between children attending schools in the most and least deprived areas has increased over time. For Reception Year children, the prevalence gap has widened from a difference of 1.01% higher in the most deprived schools in 2006-2007 to 2008-2009 to 3.64% higher in 2012-2013 to 2014-2015. In the same time periods, for Year 6 children, the obesity prevalence gap has also increased over time from 2.82% to 5.08%.

CONCLUSIONS

There is inequality in relation to obesity in primary school children in Doncaster with those in schools in the most deprived areas carrying the greatest burden. Research is needed to understand why the plateau seen nationally is not reaching the most deprived children.

Aerosol scavenging: model application and sensitivity analysis in the Indian context

Sulfate aerosols have been found to be the major contributors to precipitation acidity. Thus, in view of the long-term ecological repercussions they have on aquatic ecosystems and their acidity-potential, the present analysis focuses on a case study application of the layer-averaged aerosol-scavenging model (Okita et al., 1996) for predicting values of the wet scavenging coefficient and sulfate concentrations in precipitation samples on the basis of the information available for some selected Indian cities. Through sensitivity analysis (Pandey et al., 1997) the scavenging coefficient has been found to be very strongly dependent on precipitation intensity. Comparison of model predictions has been done with the measured values for Delhi, Mumbai, Calcutta and Chennai in India.