Clinical outcomes of Staphylococcus capitis isolation from neonates, England, 2015-2021: a retrospective case-control study

OBJECTIVE

Staphylococcus capitis, a coagulase-negative staphylococci (CoNS) species, has been increasingly detected from UK sterile site samples and has caused neonatal unit outbreaks worldwide. We compared survival to discharge and 30-day mortality for the detection of S. capitis versus other CoNS species.

METHODS

In this retrospective case-control study, we included hospitalised infants with any CoNS species detected from a normally sterile body site up to 90 days of age. We linked English laboratory reports from the Second Generation Surveillance System database, mortality data from the Personal Demographics Service, and neonatal unit admissions from the National Neonatal Research Database. In primary analysis, multivariable logistic regression was used, with two co-primary outcomes: survival to discharge and death within 30 days of positive specimen date. Sensitivity analyses using multiply imputed datasets followed.

RESULTS

We identified 16 636 CoNS episodes relating to 13 745 infants. CoNS episodes were highest among infants born extremely preterm (22-27 weeks) and with extremely low birth weight (400-999 g). In primary analysis, there were no differences in survival to discharge (p=0.71) or 30-day mortality (p=0.77) between CoNS species. In sensitivity analyses, there were no differences in outcomes between infection with four of the most common CoNS species (Staphylococcus epidermidis, S. capitis, Staphylococcus haemolyticus and Staphylococcus warneri) but the remaining CoNS species were at higher risk of adverse outcomes when treated in aggregate.

CONCLUSION

Infants with S. capitis detected from sterile site samples did not experience significant differences in either survival to discharge or 30-day mortality compared with infants with detection of other common CoNS species.

Genomic epidemiology of syphilis in England: a population-based study

BACKGROUND

Syphilis is a sexually transmitted bacterial infection caused by Treponema pallidum subspecies pallidum. Since 2012, syphilis rates have risen dramatically in many high-income countries, including England. Although this increase in syphilis prevalence is known to be associated with high-risk sexual activity in gay, bisexual, and other men who have sex with men (GBMSM), cases are rising in heterosexual men and women. The transmission dynamics within and between sexual networks of GBMSM and heterosexual people are not well understood. We aimed to investigate if whole genome sequencing could be used to supplement or enhance epidemiological insights around syphilis transmission.

METHODS

We linked national patient demographic, geospatial, and behavioural metadata to whole T pallidum genome sequences previously generated from patient samples collected from across England between Jan 1, 2012, and Oct 31, 2018, and performed detailed phylogenomic analyses.

FINDINGS

Of 497 English samples submitted for sequencing, we recovered 240 genomes (198 from the UK Health Security Agency reference laboratory and 42 from other laboratories). Three duplicate samples (same patient and collection date) were included in the main phylogenies, but removed from further analyses of English populations, leaving 237 genomes. 220 (92·8%) of 237 samples were from men, nine (3·8%) were from women, and eight (3·4%) were of unknown gender. Samples were mostly from London (n=118 [49·8%]), followed by southeast England (n=29 [12·2%]), northeast England (n=24 [10·1%]), and southwest England (n=15 [6·3%]). 180 (76·0%) of 237 genomes came from GBMSM, compared with 25 (10·5%) from those identifying as men who have sex with women, 15 (6·3%) from men with unrecorded sexual orientation, nine (3·8%) from those identifying as women who have sex with men, and eight (3·4%) from people of unknown gender and sexual orientation. Phylogenomic analysis and clustering revealed two dominant T pallidum sublineages in England. Sublineage 1 was found throughout England and across all patient groups, whereas sublineage 14 occurred predominantly in GBMSM older than 34 years and was absent from samples sequenced from the north of England. These different spatiotemporal trends, linked to demography or behaviour in the dominant sublineages, suggest they represent different sexual networks. By focusing on different regions of England we were able to distinguish a local heterosexual transmission cluster from a background of transmission in GBMSM.

INTERPRETATION

These findings show that, despite extremely close genetic relationships between T pallidum genomes globally, genomics can still be used to identify putative transmission clusters for epidemiological follow-up. This could be of value for deconvoluting putative outbreaks and for informing public health interventions.

FUNDING

Wellcome funding to the Sanger Institute, UK Research and Innovation, National Institute for Health and Care Research, European and Developing Countries Clinical Trials Partnership, and UK Health Security Agency.

Cost analysis and critical success factors of the use of oxygen concentrators versus cylinders in sub-divisional hospitals in Fiji

Background

Oxygen is vital in the treatment of illnesses in children and adults, yet is lacking in many low and middle-income countries health care settings. Oxygen concentrators (OCs) can increase access to oxygen, compared to conventional oxygen cylinders. We investigated the costs and critical success factors of OCs in three hospitals in Fiji, and extrapolated these to estimate the oxygen delivery cost to all Sub-Divisional hospitals (SDH) nationwide.

Methods

Data sources included key personnel interviews, and data from SDH records, Ministry of Health and Medical Services, and a non-governmental organisation. We used Investment Logic Mapping (ILM) to define key issues. An economic case was developed to identify the investment option that optimised value while incorporating critical success factors identified through ILM. A fit-for-purpose analysis was conducted using cost analysis of four short-listed options. Sensitivity analyses were performed by altering variables to show the best or worst case scenario. All costs are presented in Fijian dollars.

Results

Critical success factors identifed included oxygen availability, safety, ease of use, feasibility, and affordability. Compared to the status quo of having only oxygen cylinders, an option of having a minimum number of concentrators with cylinder backup would cost $434,032 (range: $327,940 to $506,920) over 5 years which would be 55% (range: 41 to 64%) of the status quo cost.

Conclusion

Introducing OCs into all SDHs in Fiji would reduce overall costs, while ensuring identified critical success factors are maintained. This study provides evidence for the benefits of OCs in this and similar settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06687-8.

Attenuated cortisol reactivity to psychosocial stress is associated with greater visual dependency in postural control

Despite known anatomical links between the hypothalamic-pituitary-adrenal (HPA) axis and the vestibular system, there are no studies on the relationship between postural control and HPA axis function. Visual dependence in postural control, often measured by increased postural sway on exposure to visual motion, is an indication of altered visual-vestibular integration with greater weighting towards visual cues for balance. Visual dependence is more common in older age and a range of vestibular and non-vestibular health conditions. The relationship between visual dependence in postural control was investigated in relation to cortisol reactivity to psychosocial stress (using the Trier Social Stress Test for groups: TSST-G), as an index of HPA axis function, in healthy young females. In those who exhibited a cortisol response (>2 nmol/l), a negative relationship between stress-induced cortisol reactivity and visual dependence in postural control was observed, since those with the largest cortisol response showed less visual motion induced postural sway (measured by force platform). This finding in healthy females indicates that subtle non-clinical differences in vestibular function are associated with dysregulated HPA axis activity as indicated by lower cortisol reactivity to psychosocial stress. It adds to the growing body of evidence linking blunted cortisol reactivity to stress to poor homeostatic regulation and potential negative health and behavioural outcomes.

Salience versus magnitude in the measurement of the cortisol awakening response

Pulsatile ultradian secretion of cortisol, rarely studied in salivary data, has functional importance in hypothalamic pituitary adrenal (HPA) axis regulation. The first daily ultradian episode, the cortisol awakening response (CAR), was examined in healthy adults, in 5-min secretion rates of salivary cortisol from electronically monitored awakening time to 1.25 h. Aggregated rates revealed a cubic trend, with wave-length of almost exactly 1 h, as predicted from known ultradian periodicity. Peak secretion rate occurred 20-min post-awakening. Peak (20-min) to trough (59-min) amplitude (PTA) expressed a salient signal shape. Rates rose steeply to and from peak, and major secretion was packaged into a few 5-min intervals, inconsistent with normal or uniform distribution of 5-min rates, but consistent with known pulsatile cortisol delivery. Null hypotheses asserting normal or uniform distributions were rejected. Maximal rates overwhelmingly occurred before and minimal rates after 30-mins, with degree of extremity at each polarity significantly positively correlated. To demonstrate utility and reliability of PTA estimation in a clinically relevant domain, re- analyses of a previously published study were conducted. Data from only three saliva samples were used, given importance of cost considerations for many CAR researchers. Difference between mean rates before and after 30-min yielded a simple salience index, highly correlated with PTA derived from full 5-min interval data. CAR salience performed significantly better than traditional AUCi magnitude in discriminating control cases (higher inferred amplitude) and cases with Seasonal Affective Disorder (lower inferred amplitude). Evidence suggested that low AUCi may be more sensitive in identifying within-subject changes (e.g. more depressed mood in winter among SAD cases) and low CAR salience better at revealing enduring between-subjects associations (e.g. underlying disorder vulnerability). Since both PTA salience and AUCi magnitude can be analysed and compared using exactly the same data from the same commonly used saliva sampling points, further research is warranted into the importance of individual differences in patterns of cortisol delivery, not just how much is delivered.

INPPL1 is associated with the metabolic syndrome in men with Type 1 diabetes, but not with diabetic nephropathy

AIMS

The metabolic syndrome is a frequent phenomenon in people with Type 1 diabetes and is associated with diabetic nephropathy. The aim of this study was to investigate if the INPPL1 (inositol polyphosphate phosphatase-like 1) gene encoding lipid phosphatase SHIP2 is associated with the metabolic syndrome and diabetic nephropathy in Finnish people with Type 1 diabetes.

METHODS

Participants were selected from the FinnDiane study for this cross-sectional study. The individuals were divided into controls without the metabolic syndrome (n = 1074) and cases with the metabolic syndrome (n = 1328), or into groups based upon their albumin excretion rate. Nine single-nucleotide polymorphisms covering the INPPL1 gene +/- 20 kb were genotyped. The associations between the single-nucleotide polymorphisms and outcome variables were analysed with the χ(2) test and logistic regression.

RESULTS

Two INPPL1 single-nucleotide polymorphisms, rs2276048 (silent mutation) and rs2276047 (intronic), were associated with the metabolic syndrome in men with odds ratios of 0.23 (95% CI 0.11-0.45, P = 2.1 × 10(-5) ), and 0.37 (0.21-0.65, P = 0.001), adjusted for age, duration of diabetes and history of smoking. When both sexes were included, these associations were less significant. No association between the genotyped single-nucleotide polymorphisms and diabetic nephropathy was observed.

CONCLUSIONS

INPPL1 gene variants may contribute to susceptibility to the metabolic syndrome in men with Type 1 diabetes, but not to diabetic nephropathy.

Hyperfiltration in type 1 diabetes: does it exist and does it matter for nephropathy?

AIMS/HYPOTHESIS

Hyperfiltration is widely regarded as a contributing factor to the development of microalbuminuria and progressive nephropathy in type 1 diabetes. However, recent studies have questioned this conclusion.

METHODS

To address this conflicting evidence, we examined the association between hyperfiltration and progression to microalbuminuria in 2,318 adults with type 1 diabetes. We also compared the estimated GFR in our diabetic patients with rates observed in 6,247 adults from the Finnish general population, using age- and sex-specific z scores.

RESULTS

The distribution of estimated GFR in adults with type 1 diabetes and normoalbuminuria was not significantly different from that expected in the general population (p = 0.51, Mann-Whitney test). Type 1 diabetic patients with a higher estimated GFR were also no more likely to develop microalbuminuria over a median of 5.2 years of follow-up than those with normal estimated GFR. This was the case regardless of whether hyperfiltration was defined by an absolute threshold, deciles of estimated GFR or a z score, using creatinine- or cystatin-based clearance formulas in men or in women.

CONCLUSIONS/INTERPRETATION

Together with other studies, these data suggest that creatinine- or cystatin-based estimates of GFR do not predict the development of microalbuminuria in patients with type 1 diabetes. Moreover, in the absence of incipient or overt nephropathy, conventionally determined renal function in patients with type 1 diabetes appears no different from that in the general population. This is hardly surprising, given that these individuals, by all definitions, do not have kidney disease.

Differences between diurnal patterns of salivary cortisol and dehydroepiandrosterone in healthy female adolescents

The adrenal hormones cortisol and dehydroepiandrosterone (DHEA) share a common secretagogue: adrenocorticotropic hormone; however, secretion of these hormones can be dissociated suggesting subtle individual regulation at the level of the adrenal gland. We examined differences in the diurnal patterns of cortisol and DHEA secretion in healthy adolescent girls, with the aim of informing the possibility of exploiting these differences to aid interpretation of data from clinical populations in which these patterns can become dysregulated. Fifty-six healthy females aged 10-18 years provided saliva samples at 0 and 30 min (morning samples) and 12 h post-awakening on 2 consecutive weekdays. For morning salivary cortisol in relation to morning DHEA concentrations, correlational analysis revealed only a trend (p = 0.054). Similarly, the association between evening cortisol and DHEA was characterised as a trend (p = 0.084). Mean morning DHEA concentrations showed more day-to-day consistency than equivalent cortisol samples (r = 0.829 for DHEA and 0.468 for cortisol; z = 3.487, p < 0.0005). Unlike the cortisol pattern, characterised by a marked awakening response (cortisol awakening response, CAR), a significant rise in DHEA concentration post-awakening was not evident. Finally, there was a strong association between morning and evening concentrations of DHEA, not found for cortisol. The study shows differences in cortisol and DHEA secretion in the post-awakening period and informs work that seeks to examine correlates of dysregulated hypothalamic-pituitary-adrenal axis function. Parallel examination of both hormones enables enhanced interpretation of aberrant patterns of the CAR, i.e. an exploration of whether dysregulation affects both hormones (reflecting overall steroidogenic capacity) or cortisol alone (CAR-specific mechanisms).

Serum adiponectin concentration is a positive predictor of all-cause and cardiovascular mortality in type 1 diabetes

BACKGROUND

Adiponectin is widely regarded as an anti-atherogenic, antioxidant and anti-inflammatory molecule. However, adiponectin concentration is paradoxically increased in individuals with type 1 diabetes, in whom it is positively associated with adverse clinical outcomes.

OBJECTIVE

To explore the association between serum adiponectin concentration and mortality outcomes in adults with type 1 diabetes.

DESIGN

Multicentre prospective cohort study.

SETTING

Primary and tertiary care.

SUBJECTS

Finnish adults with type 1 diabetes (n= 2034). Main outcome measures.  All-cause and cardiovascular mortality. Independent predictors of mortality were determined using the Cox and the Fine and Gray competing risks proportional hazards models.

RESULTS

During a median of 11 years of follow-up, there were 173 deaths (8.5%, 1.0 per hundred person-years). Adiponectin was linearly associated with all-cause mortality [Cox model: hazard ratio (HR) 1.02, 95% confidence interval (CI) 1.01-1.03, P<0.001] and cardiovascular mortality (Fine and Gray model: HR 1.02, 95% CI 1.00-1.04, P=0.035); patients with the highest adiponectin concentrations had the shortest survival. The mortality risk associated with adiponectin was independent of glycaemic and lipid control, pre-existing cardiovascular disease, markers of inflammation and the presence and severity of kidney disease.

CONCLUSIONS

Although adiponectin is generally considered to be a protective molecule, increased concentrations of adiponectin in type 1 diabetes are independently associated with all-cause and cardiovascular mortality. Moreover, the fact that this association was observed for the first time in patients with normal urinary albumin levels, who have few comorbidities, suggests that adiponectin is specifically linked with vascular damage in type 1 diabetes.

Sex-related differences in the long-term risk of microvascular complications by age at onset of type 1 diabetes

AIMS/HYPOTHESIS

This study examined sex-related differences in the cumulative risk of proliferative retinopathy (PR) and end-stage renal disease (ESRD) over 40 years of duration of type 1 diabetes according to age at diabetes onset.

METHODS

We assessed 4,416 patients from the Finnish Diabetic Nephropathy Study population. Kaplan-Meier analysis was used to provide cumulative incidence rates and Cox regression analyses for HRs.

RESULTS

There were no sex-related differences in the cumulative incidence of ESRD in patients diagnosed with type 1 diabetes between 0 to 4 and 5 to 9 years. Thereafter the risk started to diverge. The cumulative incidence of ESRD in patients diagnosed between 10 to 14 and ≥15 years was 17.4% (95% CI 13.4-21.2) and 13.0% (9.6-16.2) respectively in women, while in men it was 32.2% (28.0-36.1) and 24.6% (20.8-28.1) respectively. The respective HRs were (onset at 10 to 14 years) 1.9 (p < 0.0001) and (onset at ≥15 years) 1.8 (p < 0.001), respectively. There was no difference in the risk of PR between men and women diagnosed between 0 and 4 years of age, but progressive sex-related differences in the cumulative incidence of PR were observed with increasing age at onset. The HRs for men in the age-at-onset groups 5 to 9, 10 to 14 and ≥15 years of age were 1.3 (95% CI 1.0-1.6), 1.3 (1.1-1.6) and 2.1 (1.6-2.6) compared with women in these groups, respectively.

CONCLUSIONS/INTERPRETATION

The difference between the sexes with regard to risk of diabetic microvascular complications is highly dependent on the age at onset of diabetes. The risk of ESRD and PR risk doubled in men compared with women when age at onset was ≥15 years.

Association between mannose-binding lectin, high-sensitivity C-reactive protein and the progression of diabetic nephropathy in type 1 diabetes

AIMS/HYPOTHESIS

Diabetic nephropathy has been associated with low-grade inflammation and activation of the complement system in cross-sectional studies. Data from prospective studies are sparse. We investigated the associations of the complement activator mannose-binding lectin (MBL) and the inflammatory marker high-sensitivity C-reactive protein (hsCRP) with the development of nephropathy in a large prospective study of patients with type 1 diabetes from the Finnish Diabetic Nephropathy (FinnDiane) Study.

METHODS

Baseline MBL and hsCRP were measured in 1,564 type 1 diabetes patients from the FinnDiane study, of whom 1,010 had a normal albumin excretion rate, 236 had microalbuminuria and 318 had macroalbuminuria. The main outcome was progression in renal disease during follow-up.

RESULTS

Both baseline MBL (p = 0.038) and hsCRP (p < 0.001) increased with increasing level of albuminuria. During 5.8 +/- 2.2 years of follow-up, progression to a higher albuminuria level or end-stage renal disease (ESRD) occurred in 201 patients. MBL levels were higher in progressors compared with non-progressors at all steps of progression, and in a covariate adjusted multivariate Cox-regression analysis MBL levels above the median were significantly associated with progression from macroalbuminuria to ESRD (hazard ratio 1.88, 95% CI 1.06-3.32, p = 0.030). In a univariate analysis, hsCRP levels above the median were significantly associated with progression from normal albumin excretion rate to microalbuminuria, but the association was only borderline significant after adjustment for covariates (hazard ratio 1.56, 95% CI 0.97-2.51, p = 0.068).

CONCLUSIONS/INTERPRETATION

This study demonstrates that concentrations of both MBL and hsCRP are associated with the progression of renal disease in type 1 diabetes.

Lipid abnormalities predict progression of renal disease in patients with type 1 diabetes

AIMS/HYPOTHESIS

We studied the impact of baseline lipid variables on the progression of renal disease in a large nationwide prospective cohort of patients with type 1 diabetes.

METHODS

A total of 2,304 adult patients with type 1 diabetes and available lipid profiles participating in the Finnish Diabetic Nephropathy Study (FinnDiane) were evaluated. Data on progression of renal disease were verified from medical files and patients were followed for 5.4 +/- 2.0 (mean +/- SD) years.

RESULTS

High triacylglycerol, apolipoprotein (Apo) B, ApoA-II and HDL(3)-cholesterol concentrations predicted incident microalbuminuria. Progression to macroalbuminuria was predicted by high triacylglycerol and ApoB. When AER was entered into the model, triacylglycerol was no longer an independent predictor, but when patients with normal AER and microalbuminuria at baseline were pooled, triacylglycerol, HbA(1c), male sex and AER were all independent predictors of renal disease. High total cholesterol, LDL-cholesterol, non-HDL-cholesterol and triacylglycerol as well as low HDL-cholesterol, HDL(2)-cholesterol, ApoA-I and ApoA-II concentrations were predictive of progression to end-stage renal disease. However, when estimated GFR was entered into the model, only total cholesterol remained an independent predictor of progression.

CONCLUSIONS/INTERPRETATION

Lipid abnormalities, particularly high triacylglycerol concentrations, increase the risk of progression of renal disease.

Diurnal patterns of salivary cortisol across the adolescent period in healthy females

When examining the diurnal profile of the hormone cortisol in children and adolescents developmental issues are particularly relevant. Previous findings regarding relationships between cortisol secretory activity and reproductive (pubertal) maturation lack clarity and may reflect methodological inconsistencies between studies. This study examined the diurnal cortisol profile across female adolescence, with a particular focus on an obvious and unique marker of development: menarche. In a cross-sectional design, 61 healthy female adolescents aged 9-18 years (mean age 13.89 years, S.D.+/-2.72) collected eight saliva samples per day on two consecutive weekdays. Samples were collected at awakening, 15, 30 and 45min and 3, 6, 9 and 12h post-awakening in order to capture both the cortisol awakening response (CAR) and the subsequent period of decline. Demographic information was recorded and participants also completed the Spielberger State-Trait Anxiety Inventory. Patterns of cortisol secretion exhibited good intra-individual stability across the two sampling days. Participants evidenced a robust diurnal pattern, with cortisol levels peaking approximately 30-45min post-awakening (the CAR) and steadily declining concentrations over the remainder of the day. Differences according to developmental status (in terms of whether or not participants had experienced first menses: menarche) were observed in the time of peak secretion of the CAR, and these distinct patterns could not be accounted for by group differences in demographic, situational or psychological characteristics measured in this study. This effect for the CAR was associated with the onset of menarche alone, unlike cortisol levels over the remainder of the day. For those who had undergone menarche, were older and of greater BMI, cortisol levels remained higher over the day. There was a significant difference in cortisol concentrations at 6h post-awakening between pre- and post-menarche groups. Again, these differences in daytime cortisol secretory activity could not be attributed to situational or psychological factors. Establishing patterns of cortisol secretion in healthy female adolescents provides an important baseline from which to investigate hypothalamic-pituitary-adrenal (HPA) physiology, measured via salivary cortisol, in adolescent populations with known or suspected psychopathology.

Relationship between lipid profiles and kidney function in patients with type 1 diabetes

AIMS/HYPOTHESIS

We studied the relationship between the lipid profile, estimated GFR (eGFR) and AER in patients with type 1 diabetes. We also assessed the association between the lipid profile and glycaemic control, obesity and hypertension in an environment free of manifest renal disease, as well as exploring how well the patients would have achieved the targets set in international guidelines.

METHODS

A total of 2,927 adult patients who had type 1 diabetes and for whom lipid profiles were available were included from people participating in the nationwide, multicentre Finnish Diabetic Nephropathy Study (FinnDiane). eGFR was determined using the Cockcroft-Gault formula adjusted for body surface area.

RESULTS

Patients with impaired renal function (eGFR <60 ml min(-1) 1.73 m(-2)) had higher total cholesterol, triacylglycerol and apolipoprotein B, and lower HDL-cholesterol concentrations than patients with normal renal function (eGFR >90 ml min(-1) 1.73 m(-2)) or mildly impaired renal function (eGFR 60-90 ml min(-1) 1.73 m(-2)) (p < 0.001 for all associations). In type 1 diabetic patients without manifest renal disease, similar adverse lipid profiles could be observed in those who were overweight or obese and in those who had intermediate or poor glycaemic control or hypertension. In all the different patient groups 14 to 43% would have achieved the recommended target of <2.6 mmol/l for LDL-cholesterol.

CONCLUSIONS/INTERPRETATION

Multiple lipid abnormalities are not only present in type 1 diabetic patients with an abnormal AER, but also in those with impaired renal function. In patients without manifest renal disease, obesity, glycaemic control or hypertension were associated with an adverse lipid profile. A substantial number of patients studied would have exceeded the targets set by international guidelines, particularly the targets for LDL-cholesterol.

Suspected non-adherence and weekend versus week day differences in the awakening cortisol response

The pronounced rise in cortisol following awakening holds promise as a bio-marker of variables in the psychosocial domain, but its investigation also presents methodological challenges, which we attempted to address in this study. Forty-eight healthy, young students participated and were instructed to collect saliva 0, 15, 30 and 45 min post awakening on two consecutive normal weekdays and two consecutive weekend days (order counterbalanced). Participants' awakening cortisol response (ACR) profiles differed between the weekdays and weekend with trend analysis revealing a steeper rise on weekdays compared to the weekend. These differences were not accounted for by weekday/weekend differences in awakening time and state stress or by perceived stress over the previous month. Total salivary-free cortisol secretion (area under the cortisol curve (AUC)) over the 4 study days was negatively correlated with the measure of longer term stress and awakening time. The mean 4-day rise in cortisol (mean increase: MnInc) was also negatively correlated with awakening time. This awakening time effect was not mediated by stress or vice versa, since both were independent predictors of cortisol. In an attempt to address the ubiquitous problem of non-adherence to the requested saliva sampling regime, known to distort the shape of the ACR, suspected non-adherence (SNA) was examined by identifying instances of profiles showing no cortisol rise from the waking sample to either the 15 or 30 min sample post awakening. Analysis controlling for SNA status had no effect upon the observed associations with Perceived Stress Scale (PSS) and awakening time however it abolished the otherwise highly significant flatter profile at weekends.

The effect of dawn simulation on the cortisol response to awakening in healthy participants

Bright light exposure after awakening has been shown to elevate cortisol levels in healthy participants. The present study examined the effect of dawn simulation (a treatment for seasonal affective disorder) on the cortisol response to awakening and mood. Twelve healthy participants were supplied with a dawn simulator (The Natural Alarm Clock, Outside In, Cambridge Ltd), a bedside light that increases in intensity prior to awakening to approximately 250 lux over 30 mins when an audible alarm sounds. A counterbalanced study was performed on 4 consecutive normal weekdays, two of which were control days (no dawn simulation) and two experimental (dawn simulation). Saliva samples were taken immediately on awakening then at 15, 30 and 45 minutes post awakening on all 4 study-days. Total cortisol production during the first 45 mins after awakening was found to be significantly higher in the experimental condition than in the control condition. Participants also reported greater arousal in the experimental condition and there was a trend for an association between increased arousal and increased cortisol secretory activity under dawn simulation. This study provides supportive evidence for the role of light and the suprachiasmatic nucleus in the awakening cortisol response.

The awakening cortisol response: methodological issues and significance

The awakening cortisol response (ACR) is a discrete and distinctive part of the cortisol circadian cycle. In healthy adults salivary free cortisol concentrations increase by between 50 and 160% in the first 30 min immediately post-awakening (approximate average increase of 9 nmol/l, range 4-15 nmol/l, estimated to be equivalent to about three secretory episodes). However there are no agreed norms for the absolute concentrations of free cortisol in saliva either immediately post-awakening (range of 4.7-18.5 nmol/l) or 30 min post-awakening (range of 8.6-21.9 nmol/l). This review explores reasons for these discrepancies in normative data including confounding factors such as gender, age, awakening time, light and participant adherence. Although the physiological role of the ACR has not been clearly defined evidence is discussed that suggests it is under a distinct regulatory influence, different from the rest of the diurnal cortisol secretory cycle. Despite the difficulties associated with its measurement a range of studies have demonstrated an association between the ACR and psychosocial variables, stress and health. However it remains unclear whether positive affect and good health are consistently associated with larger or smaller awakening responses. It is early days in the search for the role and significance of the ACR. Its putative role in the regulation of physiological function across the day (e.g. the immune system) and its sensitivity to psychosocial variables make it a prime candidate as an intermediary linking mind and health.

Evidence to suggest that agonist modulation of hyperlocomotion is via post-synaptic dopamine D2 or D3 receptors

It has been suggested that a sub-population of dopamine D3 receptors is located pre-synaptically and these serve as autoreceptors in dopamine projection areas such as the nucleus accumbens/ventral striatum. To study further the physiological role and synaptic location of the dopamine D3 receptor, we have investigated the in vivo effect of the D3/D2 receptor agonist quinelorane on amphetamine-induced hyperactivity and extracellular dopamine release from the nucleus accumbens of the conscious rat. Amphetamine increased dopamine release to 202 +/- 34% of pre-injection control values, but quinelorane at 2.5 micrograms/kg, a dose which effectively blocked amphetamine-induced hyperlocomotion, had no significant effect on amphetamine-induced dopamine release. These data suggest that hyperlocomotion is mediated via post-synaptic rather than pre-synaptic dopamine receptors. Since quinelorane has significant affinity for the dopamine D3 receptor, these effects may be via post-synaptic D3 receptors; however, D2 receptor effects cannot be disregarded. In summary, these data indicate that the quinelorane effect on amphetamine-stimulated hyperlocomotion is not mediated via D3 or D2 autoreceptors, but rather a population of receptors located post-synaptically, which appear to mediate the inhibition of rat locomotor activity.

Anticonvulsant and behavioral profile of L-701,324, a potent, orally active antagonist at the glycine modulatory site on the N-methyl-D-aspartate receptor complex

The anticonvulsant and behavioral profile of the glycine/N-methyl-D-aspartate receptor antagonist L-701,324 [7-chloro-4-hydroxy-3-(3-phenoxy)phenyl-2(H)quinolone] has been examined in rodents. In mice, L-701,324 protected against seizures induced by N-methyl-DL-aspartate (ED50 = 3,4 mg/kg i.v.), pentylenetetrazol (ED50 = 2.8 mg/kg i.v.) and electroshock (ED50 = 1.4 mg/kg i.v.) but was most potent against audiogenic seizures in DBA/2 mice (ED50 = 0.96 mg/kg i.p.). L-701,324 was also active p.o. in mice (ED50 = 1.9,6.7, 20.7 and 34 mg/kg against audiogenic, electroshock-induced, N-methyl-DL-aspartate-induced and pentylenetetrazol-induced seizures, respectively) but showed weaker anticonvulsant activity in rats (ED50 = 90.5 mg/kg p.o., compared with 2.3 mg/kg i.v., against pentylenetetrazol-induced seizures), most probably because of the lower brain concentrations achieved in this species. Although anticonvulsant activity was also associated with impaired rotarod performance, L-701,324 failed to significantly increase locomotor activity or dopamine turnover in the nucleus accumbens at doses of up to 10 mg/kg i.v. in mice. Thus, in contrast to N-methyl-D-aspartate receptor ion channel blockers such as MK-801 (dizocilpine), L-701,324 is a potent, p.o. active anticonvulsant with a reduced propensity to activate mesolimbic dopaminergic systems in rodents.

Competitive NMDA receptor antagonists attenuate the behavioural and neurochemical effects of amphetamine in mice

We have previously reported that the glycine/NMDA receptor antagonist, R-(+)-HA-966 (R-(+)-3-amino-1-hydroxypyrrolid-2-one), attenuates amphetamine-induced activation of mesocorticolimbic dopamine neurones. In the present study, the effects of the competitive NMDA receptor antagonists, CGS 19755 (cis-4-(phosphonomethyl)piperidine-2-carboxylic acid) and (+/-)-CPP ((+/-)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid) were examined in mice. In the absence of any neurochemical effects per se, both compounds (2 or 5 mg/kg) significantly attenuated amphetamine-induced 3,4-dihydroxyphenylalanine (DOPA) accumulation in the nucleus accumbens and striatum. Furthermore, amphetamine-induced hyperlocomotion was also antagonised following pretreatment with CGS 19755 (ED50 = 2.4 mg/kg) or (+/-)-CPP (ED50 = 5.8 mg/kg) at doses which did not impair spontaneous locomotor activity. Thus, in addition to blockade of the glycine modulatory site, competitive antagonism at the NMDA receptor also attenuates psychostimulant-induced activation of forebrain dopamine neurones.

The anticonvulsant and behavioural profile of L-687,414, a partial agonist acting at the glycine modulatory site on the N-methyl-D-aspartate (NMDA) receptor complex

1. The anticonvulsant and behavioural effects of the glycine/NMDA receptor partial agonist, L-687,414 (R(+)-cis-beta-methyl-3-amino-1-hydroxypyrrolid-2-one) have been investigated in rodents. 2. L-687,414 dose-dependently antagonized seizures induced by N-methyl-D,L- aspartic acid (NMDLA, ED50 = 19.7 mg kg-1), pentylenetetrazol (PTZ, ED50 = 13.0 mg kg-1) and electroshock (ED50 = 26.1 mg kg-1) when given intravenously 15 min before test, in male Swiss Webster mice but was most potent against audiogenic seizures induced by a 120 dB bell in DBA/2 mice (ED50 = 5.1 mg kg-1, i.p., 30 min before test). 3. L-687,414 also induced impairments of performance in a rotarod test in both Swiss Webster and DBA/2 mice and the ratio [rotarod MED:anticonvulsant ED50] varied between 0.9 and 5, depending on the convulsant used. 4. Similar behaviours to those seen after administration of the non-competitive NMDA receptor antagonist, MK-801 (head weaving, body rolling, hyperlocomotion) were seen in the mouse after giving L-687,414, although the peak effect occurred at a dose (100 mg kg-1) which was 5-20 times the anticonvulsant ED50S, depending on the convulsant used. Unlike MK-801, however, doses of L-687,414 that were behaviourally stimulant did not increase dopamine turnover in the nucleus accumbens. 5. Consistent with the interaction of L-687,414 with the glycine/NMDA receptor, the anticonvulsant, ataxic and motor stimulant effects of the compound were significantly attenuated by the glycine/NMDA receptor agonist, D-serine (10-100 micrograms per mouse, i.c.v.). 6. The results show that L-687,414 is a potent, orally active anticonvulsant with a more benign pharmacological profile than antagonists acting at the ion channel of the NMDA receptor complex. The compound is a useful tool with which to probe the functional role of the glycine co-agonist site in vivo.

The glycine/NMDA receptor antagonist, R-(+)-HA-966, blocks activation of the mesolimbic dopaminergic system induced by phencyclidine and dizocilpine (MK-801) in rodents

1. The effects of the glycine/N-methyl-D-aspartate (NMDA) receptor antagonist, R-(+)-HA-966 on the neurochemical and behavioural responses to phencyclidine (PCP) and dizocilpine (MK-801) have been determined in rodents. 2. In rats, pretreatment with PCP (5 and 10 mg kg-1) or MK-801 (0.25 and 0.5 mg kg-1) dose-dependently stimulated dopamine turnover in nucleus accumbens, amygdala and medial prefrontal cortex, but had no effect in striatum. In contrast, pretreatment with (+)-HA-966 (10 and 30 mg kg-1) did not affect dopamine turnover in any brain region investigated. 3. Pretreatment with (+)-HA-966 (10 and 30 mg kg-1) significantly antagonized the stimulation of dopamine turnover induced by both PCP (10 mg kg-1) and MK-801 (0.5 mg kg-1) in rat nucleus accumbens, amygdala and medial prefrontal cortex. 4. Intracerebral dialysis studies in conscious rats demonstrated that systemic injection of PCP (10 mg kg-1) markedly stimulated dopamine release from the nucleus accumbens, an effect that was abolished by pretreatment with (+)-HA-966 (30 mg kg-1). 5. Pretreatment with PCP (3-30 mg kg-1) or MK-801 (0.1-1.6 mg kg-1) significantly increased locomotor activity in mice. In contrast, subcutaneous injection of (+)-HA-966 (10-100 mg kg-1) failed to stimulate activity. 6. Pretreatment with (+)-HA-966 (10 and 30 mg kg-1) dose-dependently antagonized both PCP (10 mg kg-1) and MK-801 (0.4 mg kg-1) induced hyperactivity in mice. 7. Blockade of PCP-induced hyperactivity by (+)-HA-966 is unlikely to be explained by the induction or potentiation of sedation/ataxia since PCP-induced rotarod deficits were not significantly different in mice pretreated with (+)-HA-966 (30 mg kg-1) or saline.8. The results demonstrate that (+ )-HA-966 antagonizes both the neurochemical and behavioural effects of PCP and MK-801, possibly through interactions at the glycine/NMDA receptor.

Behavioural and biochemical evidence of the interaction of the putative antipsychotic agent, BMY 14802 with the 5-HT1A receptor

The behavioural and biochemical profile of the sigma ligand and putative antipsychotic agent, BMY 14802 (alpha-(4-fluorophenyl)-4-(5-fluoro-2- pyrimidinyl)-1-piperazine butanol) has been determined in the mouse and rat. In mice, pretreatment with BMY 14802 attenuated both amphetamine-induced hyperactivity and conditioned avoidance responding, consistent with its previously reported antipsychotic potential. In common with 5-HT1A receptor agonists or partial agonists, BMY 14802 induced (a) a dose-dependent hypothermia in mice; (b) aspects of the 5-HT behavioural syndrome in rats, (c) antagonised mescaline-induced head twitches in mice and (d) generalised to the 8-hydroxy-2-(di-n-propylamino)tetralin discriminative stimulus over the dose range of 3-15 mg/kg. BMY 14802 had appreciable affinity for the 5-HT1A receptor (pIC50 = 6.7 compared to 7.3 for sigma binding) and antagonised forskolin-stimulated adenylate cyclase activity with a pEC50 of 6.2, consistent with an agonist action at this receptor. The results support the involvement of 5-HT1A receptors, but not the sigma binding site, in the behavioural profile of BMY 14802.

R-(+)-HA-966, a glycine/NMDA receptor antagonist, selectively blocks the activation of the mesolimbic dopamine system by amphetamine

1. The effects of the glycine/NMDA receptor antagonist, (+)-HA-966 on the neurochemical and behavioural responses to amphetamine have been determined in the mouse and rat. 2. In vehicle-treated control mice, (+)-HA-966 (30-100 mg kg-1) did not affect dopamine synthesis in either the nucleus accumbens or striatum and was without marked effect on spontaneous locomotor activity. 3. In the mouse, (+)-HA-966 (30 and 100 mg kg-1) dose-dependently blocked the enhancement of dopamine synthesis induced in the nucleus accumbens by amphetamine, but was without effect on the increase in dopamine synthesis in the striatum. 4. Intracerebroventricular administration of the glycine/NMDA receptor antagonist, 5,7-dichlorokynurenic acid, in the mouse (10 micrograms) also significantly attenuated amphetamine-enhanced DOPA accumulation in the nucleus accumbens, but not in the striatum. 5. The decrease of dopamine synthesis in striatum and nucleus accumbens induced by the dopamine receptor agonist, apomorphine, was unaffected by (+)-HA-966 (100 mg kg-1). 6. (+)-HA-966 (30 mg kg-1) failed to attenuate the hyperactivity induced by the systemic administration of amphetamine in the mouse, but totally prevented the hyperlocomotion following infusion of amphetamine into the rat nucleus accumbens. In contrast, stereotyped behaviour induced by infusion of amphetamine into the rat striatum was not altered following pretreatment with (+)-HA-966 (30 mg kg-1). 7. The results are consistent with a selective facilitatory role of glycine/NMDA receptors on mesolimbic dopaminergic neurones.

The occurrence of capillary endothelial mitoses in the mesenchyme of the scala tympani during fetal development of the guinea pig

Mitotic figures were found in the capillary endothelial cells of the cochleae of guinea pig fetuses, indicating a cellular proliferation. The significance of capillary sprouting in the mesenchyme beneath the basilar membrane a few days before opening of the scala tympani is discussed.

Licht- und elektronenmikroskopische Untersuchungen zur Entwicklung der Prominentia spiralis im Ductus cochlearis von Meerschweinchenfeten

The anlage of the spiral prominence can be seen on the 37th day of development as a small protrusion of the epithelium towards the lumen of the cochlear duct. During the further progress, the spiral prominence more distinctly protrudes by augmentation of the vascularized connective tissue. In the epithelial cells pinocytotic vesicles near the plasmalemma are seen earliest lateral and basal on the 37th day, apical on the 39th day. The epithelial cells send basal cytoplasmic extensions towards the connective tissue. Starting on the 44th day, small invaginations of connective tissue extend into the epithelium, remaining separated from the epithelial cells by the basal lamina. Until the 48th day, the monostratified epithelium remains columnar, thereafter it changes to cuboidal or flat. Towards the end of the development, the invaginations of the connective tissue nearly reach the surface of the epithelium, being separated from the endolymph by a small epithelial area.

[Light and electron microscopy studies of the development of Reissner's membrane in the cochlear duct of guinea pig fetuses]

Differentiation of the Reissner's membrane (membrana vestibularis) is described in precisely dated guinea pig fetuses. In newborn and adult animals, the Reissner's membrane consists of two layers of flat cells, an epithelial one and a mesenchymal one, separated by a basement membrane. The epithelial part develops from the initially simple columnar epithelium of the upper wall of the cochlear duct. The mesenchymal part arises from the embryonic connective tissue, which in early developmental stages occupies the space of the later scala vestibuli. The studies show that during fetal life, a mixture of the endolymph of the cochlear duct with the perilymph of the scala vestibuli is prevented by zonulae occludentes between the epithelial cells of Reissner's membrane. On the other hand, even at an early stage an exchange of material between the two fluids is to a small extent possible by means of cytopempsis through the cytoplasm of the epithelial cells.

Epithelioid cell granulomata in the mucosa of the small intestine in Whipple's disease

This report is the first description of sarcoid-like epithelioid cell granulomata in the mucosa of the small intestine in a case of Whipple's disease. The epithelioid cells do not contain PAS-positive material or products of bacterial degradation. Their ultrastructural features characterize them as histiocytes which have become secretory rather than phagocytic. These sarcoid-like lesions are considered to be a morphological manifestation of an immunological process in Whipple's disease and not to represent evidence of sarcoidosis as a concomitant or associated disorder.

The limbus spiralis and its relationship to the developing tectorial membrane in the cochlear duct of the Guinea pig fetus

The development of the interdental cells of the limbus spiralis and of the inner spiral sulcus cells as well as the formation of the mesenchymal teeth of Huschke are described during fetal life up to the day of birth in the guinea pig. Additionally, the changes of the developing tectorial membrane are studied. The ultrastructural observations allow the conclusion that during fetal development at least a considerable part of the material of the tectorial membrane is secreted by the interdental cells of the limbus spiralis.

[Light and electron microscopic studies of the greater epithelial ridge and its relationship to the developing tectorial membrane in the cochlear duct of the guinea pig (author's transl)]

In early stages of fetal development (36th day, 3rd turn) the thickening of the epithelium at the basal side of the cochlear duct forms two ridges. Later in fetal development the laterally situated lesser epithelial ridge forms the major part of the organ of Corti, whereas the medially situated greater epithelial ridge contributes only a small part to this organ. The medial part of the greater ridge consists of the columnar inner supporting cells, which bear a border of closely packed microvilli at their upper surface. Up to the time of the opening of the internal spiral sulcus in the 48th day of fetal development, there is a close spacial relationship between microvilli and filaments of the tectorial membrane. We conclude that the inner supporting cells contribute to the formation of the tectorial membrane. However, thus far we cannot entirely exclude a different possibility, that the inner supporting cells absorb material of the tectorial membrane. During the opening of the sulcus spiralis internus the inner supporting cells become considerably smaller, some of them undergo complete destruction by cytolysis, with pyknosis and karyorrhexis.

[Functional morphology of stria vascularis after treatment with ethacrynic acid or atoxyl (author's transl)]

Surface alterations of the stria vascularis and Reissner's membrane were studied in guinea pigs following intravenous or intraperitoneal administration of ethacrynic acid or atoxyl. DC-potential was measured in the same animals during intoxication. In addition we studied changements in potassium concentration (perilymph, endolymph) of the atoxyl-treated animals.