Neonatal mortality risk of large-for-gestational-age and macrosomic live births in 15 countries, including 115.6 million nationwide linked records, 2000-2020

OBJECTIVE

We aimed to compare the prevalence and neonatal mortality associated with large for gestational age (LGA) and macrosomia among 115.6 million live births in 15 countries, between 2000 and 2020.

DESIGN

Population-based, multi-country study.

SETTING

National healthcare systems.

POPULATION

Liveborn infants.

METHODS

We used individual-level data identified for the Vulnerable Newborn Measurement Collaboration. We calculated the prevalence and relative risk (RR) of neonatal mortality among live births born at term + LGA (>90th centile, and also >95th and >97th centiles when the data were available) versus term + appropriate for gestational age (AGA, 10th-90th centiles) and macrosomic (≥4000, ≥4500 and ≥5000 g, regardless of gestational age) versus 2500-3999 g. INTERGROWTH 21st served as the reference population.

MAIN OUTCOME MEASURES

Prevalence and neonatal mortality risks.

RESULTS

Large for gestational age was common (median prevalence 18.2%; interquartile range, IQR, 13.5%-22.0%), and overall was associated with a lower neonatal mortality risk compared with AGA (RR 0.83, 95% CI 0.77-0.89). Around one in ten babies were ≥4000 g (median prevalence 9.6% (IQR 6.4%-13.3%), with 1.2% (IQR 0.7%-2.0%) ≥4500 g and with 0.2% (IQR 0.1%-0.2%) ≥5000 g). Overall, macrosomia of ≥4000 g was not associated with increased neonatal mortality risk (RR 0.80, 95% CI 0.69-0.94); however, a higher risk was observed for birthweights of ≥4500 g (RR 1.52, 95% CI 1.10-2.11) and ≥5000 g (RR 4.54, 95% CI 2.58-7.99), compared with birthweights of 2500-3999 g, with the highest risk observed in the first 7 days of life.

CONCLUSIONS

In this population, birthweight of ≥4500 g was the most useful marker for early mortality risk in big babies and could be used to guide clinical management decisions.

The Hunger for Salt: A Tribute to Derek Denton and Jay Schulkin with an Updated Collection of Papers on Salt Appetite

This collection of outstanding papers is a trove for all concerned with salt intake [...].

Neonatal mortality risk for vulnerable newborn types in 15 countries using 125.5 million nationwide birth outcome records, 2000-2020

OBJECTIVE

To compare neonatal mortality associated with six novel vulnerable newborn types in 125.5 million live births across 15 countries, 2000-2020.

DESIGN

Population-based, multi-country study.

SETTING

National data systems in 15 middle- and high-income countries.

METHODS

We used individual-level data sets identified for the Vulnerable Newborn Measurement Collaboration. We examined the contribution to neonatal mortality of six newborn types combining gestational age (preterm [PT] versus term [T]) and size-for-gestational age (small [SGA], <10th centile, appropriate [AGA], 10th-90th centile or large [LGA], >90th centile) according to INTERGROWTH-21st newborn standards. Newborn babies with PT or SGA were defined as small and T + LGA was considered as large. We calculated risk ratios (RRs) and population attributable risks (PAR%) for the six newborn types.

MAIN OUTCOME MEASURES

Mortality of six newborn types.

RESULTS

Of 125.5 million live births analysed, risk ratios were highest among PT + SGA (median 67.2, interquartile range [IQR] 45.6-73.9), PT + AGA (median 34.3, IQR 23.9-37.5) and PT + LGA (median 28.3, IQR 18.4-32.3). At the population level, PT + AGA was the greatest contributor to newborn mortality (median PAR% 53.7, IQR 44.5-54.9). Mortality risk was highest among newborns born before 28 weeks (median RR 279.5, IQR 234.2-388.5) compared with babies born between 37 and 42 completed weeks or with a birthweight less than 1000 g (median RR 282.8, IQR 194.7-342.8) compared with those between 2500 g and 4000 g as a reference group.

CONCLUSION

Preterm newborn types were the most vulnerable, and associated with the highest mortality, particularly with co-existence of preterm and SGA. As PT + AGA is more prevalent, it is responsible for the greatest burden of neonatal deaths at population level.

Vulnerable newborn types: Analysis of population-based registries for 165 million births in 23 countries, 2000-2021

OBJECTIVE

To examine the prevalence of novel newborn types among 165 million live births in 23 countries from 2000 to 2021.

DESIGN

Population-based, multi-country analysis.

SETTING

National data systems in 23 middle- and high-income countries.

POPULATION

Liveborn infants.

METHODS

Country teams with high-quality data were invited to be part of the Vulnerable Newborn Measurement Collaboration. We classified live births by six newborn types based on gestational age information (preterm <37 weeks versus term ≥37 weeks) and size for gestational age defined as small (SGA, <10th centile), appropriate (10th-90th centiles), or large (LGA, >90th centile) for gestational age, according to INTERGROWTH-21st standards. We considered small newborn types of any combination of preterm or SGA, and term + LGA was considered large. Time trends were analysed using 3-year moving averages for small and large types.

MAIN OUTCOME MEASURES

Prevalence of six newborn types.

RESULTS

We analysed 165 017 419 live births and the median prevalence of small types was 11.7% - highest in Malaysia (26%) and Qatar (15.7%). Overall, 18.1% of newborns were large (term + LGA) and was highest in Estonia 28.8% and Denmark 25.9%. Time trends of small and large infants were relatively stable in most countries.

CONCLUSIONS

The distribution of newborn types varies across the 23 middle- and high-income countries. Small newborn types were highest in west Asian countries and large types were highest in Europe. To better understand the global patterns of these novel newborn types, more information is needed, especially from low- and middle-income countries.

Long-term Exposure to Ambient PM2.5 and Self-Reported Health: Evidence from Longitudinally-linked Census Data

ObjectivesThis paper estimates associations between long-term exposure to ambient particulate air pollution and 13 self-reported health outcomes including poor general health, chronic illness, experiencing long-running difficulties with breathing, and experiencing frequent periods of confusion or memory loss. It examines the extent to which these associations are explained by confounding factors. ApproachLongitudinally-linked Census data from the Northern Ireland Longitudinal Study linked to data on annual average particulate (PM2.5) concentrations at the 1km grid-square level over the period 2002-2010, exploiting complete residential histories, are used. The paper controls for potentially confounding factors at the neighbourhood, household and individual level, including for prior health, in a multivariate regression framework. Robustness to the presence of remaining unobserved confounders is assessed in two extensions, first by assuming selection on unobservables is proportional to selection on observables, and second through inclusion of an extensive set of fixed effects in the model. ResultsThere are strong statistical associations between long-term exposure to ambient particulate pollution and all 13 health outcomes measured by the 2011 Northern Ireland Census. Most of these estimated associations survive conditioning on an extensive set of observable controls. Of these, however, only two associations – with chronic illness and with long-running breathing difficulties, where we might expect the strongest causal effects – survive further analysis designed to elicit robustness to selection on unobservables. The estimated magnitudes of these remaining effects are non-trivial. For example, a 5 µg/m3 difference in particulate exposure averaged over 9 years has a similar magnitude effect on the probability of reporting long-running breathing difficulties as the difference between those aged in their 20s and those in their 40s. ConclusionsThis study provides evidence of substantial effects of long-term exposure to ambient particulates on the probabilities of experiencing chronic illness and long-running breathing difficulties. These are qualitatively robust to both observed and unobserved confounders. Associations between particulate exposure and other health outcomes in the study are shown to reflect confounders.

Exposure to PM 2.5 and Birth Outcomes: Evidence from a Population-wide Database

This paper links localised annual average ambient air pollution data to a population database of births in Northern Ireland between 2011 and 2017 to investigate the relationship between particulate matter (PM) 2.5 exposure during pregnancy and a range of birth outcomes, with a focus on birth weight. Linear regression analysis is used to estimate the effect of exposure to PM 2.5 during pregnancy on commonly studied markers of infant health (birth weight, preterm birth), less commonly studied markers such as Apgar scores, and markers of placental health which potentially represent a mechanism through which pollution might negatively affect newborns. In addition to maternal characteristics and weather conditions, detailed adjustment is made for area of residence. Moreover, comparisons of birth outcomes are drawn amongst siblings born at different times and subject to different levels of in utero exposure, permitting adjustment for mother-specific factors common to siblings. Most birth outcomes exhibit a strong unadjusted association with PM 2.5 exposure that conforms with expectations. For birth weight, the negative effect of PM 2.5 weakens slightly after adjusting for differences in maternal characteristics and weather, but weakens much further after adjusting additionally for area of residence. After adjustment, being born to mothers in the middling (6-10 micrograms per cubic metre) and highest (10-16 micrograms per cubic metre) categories of exposure is associated with a 12 gram and 32 gram reduction in mean birth weight, respectively, compared to being born into the lowest (3-6 micrograms per cubic metre) category. However, after adjusting additionally for mother-specific factors, these effects become statistically no different from zero. This holds for other outcomes, including measures of placental health. We find little evidence that exposure to PM 2.5 is related to worse infant health once we adjust as fully as possible for omitted variable bias. We conclude that the association between PM 2.5 and birth outcomes in this population at least partly reflects unmeasured characteristics of families.

The Impact of School Exclusion on Educational Achievement: Evidence from English Administrative Data

Around 800,000 children experience exclusion from school every year in England, which can have significant and long-lasting effects, especially on educational achievement. Existing papers on the impact of school exclusion on children's outcomes mainly investigate the correlational relationship using US data. There is a lack of empirical evidence from other countries examining whether this relationship is causal. Longitudinal administrative data provide the ideal opportunity to test the hypothesis that children who are excluded go on to have lower educational achievement as a result. This paper aims to measure the effect of exclusion in school-aged children. We use individual-level administrative data: the National Pupil Database (NPD) from school year 2004/05 to 2016/17. The NPD is maintained by the UK Department of Education and contains information on all pupils in state-funded schools in England. Detailed characteristics about the pupils and the schools are recorded. Student outcomes include the pupils'test scores, prior attainment, and progression at each Key Stage. In terms of school exclusion, we have detailed information on the time, school term when the exclusion occurred, and the type, reason and number of sessions for each exclusion. To estimate the impact of school exclusion on the educational achievement of pupils, fixed effect models at individual level will be applied using the longitudinal dataset. We will control for the socio-economic characteristics of pupils, households and schools, for example age, gender, ethnic group, cohort, special education needs, location, siblings, school type, and other aggregate level characteristics. Having already conducted a comprehensive literature review, and with data expected to be available in September, we anticipate preliminary results this autumn.

Ambient Air Pollution and Health in Northern Ireland

The breathing of polluted air is associated with the development and exacerbation of various health conditions, and the cost of treating such conditions is substantial. However, while the correlation with respiratory-related health conditions is well documented, less is known about this relationship from a longitudinal perspective and how pollution affects other health problems, such as neurodegenerative diseases (e.g. dementia) or diseases of the endocrine system (e.g. diabetes). More research is therefore needed to better identify the health risks and costs of pollution. The aim of this study is to investigate the relationship between exposure to ambient air pollution and health outcomes at the individual level. The analysis is based on data from the Northern Ireland Longitudinal Study (NILS) - a representative 28% sample of the Northern Ireland population drawn from an administrative health database and linked to Census returns and other administrative databases - linked with routinely collected prescriptions data. Exposure to air pollution is assessed by linking modelled background pollution data at a 1x1 km grid square resolution to residential address. Annual measures of eight separate pollutants will allow us to examine cumulative exposure between 2001 and 2016. Regression analysis will be used to estimate the health effects of exposure to air pollution. Preliminary analysis currently underway will focus on outcomes such as self-reported health at the 2011 Census (e.g. the presence of breathing difficulties and memory loss) and all-cause and respiratory-related mortality since 2001. Stage two of the analysis will utilise the prescriptions linkage to define illness-specific health outcomes using receipt of medicines prescribed by General Practitioners (GPs) to treat cardiovascular- and respiratory-related health conditions as well as diabetes, dementia and Parkinsonism. Longitudinal analysis will enable us to assess whether these relationships are affected by unobserved confounders. Preliminary results for both stages of the analysis are expected by autumn 2019.

Autism and Schizophrenia: Intestinal Disorders

We examined Dohan's hypothesis that schizophrenia is associated with the absorption of "exorphins" contained in gluten and casein. In addition, because of the work of Reichelt et al. (Reichelt, K.L., Saelid, G., Lindback, J. and Orbeck, H. (1986) Biological Psychiatry 21:1279-1290) and Rodriguez et al. (Rodriguez, Trav, A.L., Barreiro Marin, R, Galvez, Borrero, I.M., del Olmo Romero-Nieva, F. and Diaz Alvarez, A. (1994) Journal of Nervous and Mental Disease Aug; 182(8): 478-479), we carried out similar studies on a group of children with autism. In both syndromes we found similar patterns of peptide containing peaks (Ninhydrin positive) after molecular screening with Sephadex G-15. Immunoglobulin assay of IgA and IgG against gliadin and casein in serum was done. High titer IgG antibodies to gliadin were found in 87% of autistic and 86% of schizophrenic patients and high titer IgG antibodies to bovine casein were found in 90% of autistic and in 93% of schizophrenic patients. High titer IgA antibodies to gluten or casein were found in 30% of children with autism while in schizophrenic patients 86% had elevated IgA antibodies to gluten and 67% to casein; some normal children and adults have these antibodies but only in trace amounts. When schizophrenic patients were treated with dialysis or a gluten-casein free diet, or both (Cade, R., Wagemaker, H., Privette, R.M., Fregly, M., Rogers, J. and Orlando, J. (1990) Psychiatry: A World Prespective 1: 494-500) peptiduria and Brief Psychiatric Rating Scores fell while abnormal behavior diminished. A gluten-casein free diet was accompanied by improvement in 81% of autistic children within 3 months in most of the behavior categories. Our data provide support for the proposal that many patients with schizophrenia or autism suffer due to absorption of exorphins formed in the intestine from incomplete digestion of gluten and casein.

Effectiveness and cost effectiveness of counselling in primary care

BACKGROUND

The prevalence of mental health and psychosocial problems in primary care is high. This review examines the clinical and cost-effectiveness of psychological therapies provided in primary care by counsellors.

OBJECTIVES

To assess the effectiveness and cost effectiveness of counselling in primary care by reviewing cost and outcome data in randomised controlled trials for patients with psychological and psychosocial problems considered suitable for counselling.

SEARCH STRATEGY

To update the review, the following electronic databases were searched on 25-10-2005: MEDLINE, EMBASE, PsycLIT, CINAHL, the Cochrane Controlled Trials register and the Cochrane Collaboration Depression, Anxiety and Neurosis (CCDAN) trials registers.

SELECTION CRITERIA

All controlled trials comparing counselling in primary care with other treatments for patients with psychological and psychosocial problems considered suitable for counselling. Trials completed before the end of June 2005 were included in the review.

DATA COLLECTION AND ANALYSIS

Data were extracted using a standardised data extraction sheet. Trials were rated for quality using CCDAN criteria, to assess the extent to which their design and conduct were likely to have prevented systematic error. Continuous measures of outcome were combined using standardised mean differences. An overall effect size was calculated for each outcome with 95% confidence intervals (CI). Continuous data from different measuring instruments were transformed into a standard effect size by dividing mean values by standard deviations. Sensitivity analyses were undertaken to test the robustness of the results. Economic analyses were summarised in narrative form.

MAIN RESULTS

Eight trials were included in the review. The analysis found significantly greater clinical effectiveness in the counselling group compared with usual care in the short-term (standardised mean difference -0.28, 95% CI -0.43 to -0.13, n = 772, 6 trials) but not the long-term (standardised mean difference -0.09, 95% CI -0.27 to 0.10, n = 475, 4 trials). Levels of satisfaction with counselling were high. There was some evidence that the overall costs of counselling and usual care were similar.

AUTHORS' CONCLUSIONS

Counselling is associated with modest improvement in short-term outcome compared to usual care, but provides no additional advantages in the long-term. Patients are satisfied with counselling. Although some types of health care utilisation may be reduced, counselling does not seem to reduce overall healthcare costs.

Role of angiotensin II and the subfornical organ in the pharmacological actions of ethanol

AIMS

The current study was designed to evaluate if angiotensin II mediates the hypothermic effects of ethanol, and to determine if the effects of angiotensin are mediated centrally. We also tested the hypothesis that the subfornical organ (SFO) is a site responsible for the alterations in body temperature and aerial righting reflex mediated by ethanol and for the modulation of ethanol consumption in rats.

METHODS

Male Sprague-Dawley rats were used in a series of experiments to evaluate the role of both peripheral and central administration of losartan, a selective angiotensin type 1 receptor antagonist on ethanol-induced hypothermia. Subsequent studies were undertaken in SFO-lesioned rats to evaluate the effects of SFO-lesion on alcohol intake, the thermal response to alcohol and angiotensin, and the aerial righting reflex.

RESULTS

Selective antagonism of the angiotensin II type 1 receptor, administered either peripherally or centrally, attenuated not only the fall in colonic temperature but also attenuated the transient rise in tail skin temperature that was associated with administration of ethanol. The thermal responses to both angiotensin and ethanol were similarly attenuated in SFO-lesioned rats. Likewise the aerial righting reflex, which has previously been shown to be impaired by losartan treatment, was also significantly attenuated in SFO-lesioned animals. Alcohol intake, as determined by a 48 h, two-bottle preference test also revealed that SFO-lesioned animals consumed significantly less alcohol (ethanolic beer) than did controls.

CONCLUSION

Collectively, the results demonstrate that ethanol-induced temperature responses are mediated by the renin-angiotensin system and that this interaction is mediated centrally. In addition, the results demonstrate that the SFO is a site that mediates several neurobiological effects of ethanol, possibly via the renin-angiotensin system.

The clinical effectiveness of counselling in primary care: a systematic review and meta-analysis

BACKGROUND

Counselling is frequently used in the management of common mental disorders (such as anxiety and depression) in primary care. However, there are concerns over the clinical effectiveness of counselling, both in comparison with usual general practitioner care, and with other treatments such as alternative psychological therapies and antidepressant treatment. This study used systematic review methodology to assess the current evidence-base.

METHOD

A systematic literature review located seven trials of relevance, comparing counselling with usual general practitioner care, cognitive-behaviour therapy and antidepressant medication. Data on internal and external validity were examined using a standardized quality rating scheme. Data concerning the impact of counselling on symptoms of anxiety and depression were pooled using meta-analytical procedures.

RESULTS

The main analyses showed significantly greater clinical effectiveness of counselling compared with usual general practitioner care in the short-term (standardized mean difference -0.28, 95% CI -0.43 to -0.13, N=741, six trials) but not the long-term (standardized mean difference -0.07, 95% CI -0.26 to 0.12, N=447, four trials). Sensitivity analyses were undertaken to test the robustness of the results.

CONCLUSION

Counselling is associated with modest improvement in short-term outcome compared with usual general practitioner care, and thus may be a useful addition to mental health services in primary care.

Effectiveness and cost effectiveness of counselling in primary care

BACKGROUND

Counsellors are prevalent in primary care settings. However, there are concerns about the clinical and cost-effectiveness of the treatments they provide, compared with alternatives such as usual care from the general practitioner, medication or other psychological therapies.

OBJECTIVES

To assess the effectiveness and cost effectiveness of counselling in primary care by reviewing cost and outcome data in randomised controlled trials, controlled clinical trials and controlled patient preference trials of counselling interventions in primary care, for patients with psychological and psychosocial problems considered suitable for counselling.

SEARCH STRATEGY

The original search strategy included electronic searching of databases (including the CCDAN Register of RCTs and CCTs) along with handsearching of a specialist journal. Published and unpublished sources (clinical trials, books, dissertations, agency reports etc.) were searched, and their reference lists scanned to uncover further controlled trials. Contact was made with subject experts and CCDAN members in order to uncover further trials. For the updated review, searches were restricted to those databases judged to be high yield in the first version of the review: MEDLINE, EMBASE, PSYCLIT and CINAHL, the Cochrane Controlled Trials register and the CCDAN trials register.

SELECTION CRITERIA

All controlled trials comparing counselling in primary care with other treatments for patients with psychological and psychosocial problems considered suitable for counselling. Trials completed before the end of June 2001 were included in the review.

DATA COLLECTION AND ANALYSIS

Data were extracted using a standardised data extraction sheet. The relevant data were entered into the Review Manager software. Trials were quality rated, using CCDAN criteria, to assess the extent to which their design and conduct were likely to have prevented systematic error. Continuous measures of outcome were combined using standardised mean differences. An overall effect size was calculated for each outcome with 95% confidence intervals. Continuous data from different measuring instruments were transformed into a standard effect size by dividing mean values by standard deviations. In view of the diversity of counselling services in primary care (the range of treatments, patients and practitioners) tests of heterogeneity were done to assess the feasibility of aggregating measures of outcome from trials. Sensitivity analyses were undertaken to test the robustness of the results.

MAIN RESULTS

Seven trials were included in the review. The main analyses showed significantly greater clinical effectiveness in the counselling group compared with 'usual care' in the short-term (standardised mean difference -0.28, 95% CI -0.43 to -0.13, n=772, 6 trials) but not the long-term (standardised mean difference -0.09, 95% CI -0.27 to 0.10, n=475, 4 trials). Levels of satisfaction with counselling were high. Four studies reported similar total costs associated with counselling and usual care over the long-term. However, the economic analyses were likely to be underpowered.

REVIEWER'S CONCLUSIONS

Counselling is associated with modest improvement in short-term outcome compared to 'usual care', but provides no additional advantages in the long-term. Patients are satisfied with counselling, and it may not be associated with increased costs.

Lateral videofluoroscopy: a modification to aid in velopharyngeal assessment and measurement

To overcome the difficulty of obtaining adequate videofluoroscopic images with small children because of lack of cooperation and their inability to keep their heads still and correctly rotated, a 3D View-Master was attached to the x-ray table. Its use greatly increased the ability to conduct lateral videofluoroscopies of small children by improving patient compliance, stabilizing rotation and reducing unwanted head movement, and by standardizing magnification.

Screening for patients at risk of alcohol related problems: the results of the York District Hospital Alcohol Study

This study examined the feasibility of training medical and nursing staff in the use of a brief Alcohol Screening Questionnaire, which assists the early identification of patients who drink to excess. Over a two-year period 7,217 questionnaires were completed on patients admitted to York District General Hospital. Analysis showed the screening questionnaire to be a quick and reliable instrument, although the characteristics of the screener influenced its effectiveness. The results suggest that hospital staff require little training before they can effectively identify patients who drink to excess.

Identification of alcohol-related problems in a general hospital setting: a cost-effectiveness evaluation

Alcohol is a major cause of morbidity and mortality. The prevention of alcohol problems would result in significant savings to the NHS and society. Screening is an important step in preventing problems. This study examines the costs of screening patients for alcohol problems. Over a 21-month period doctors, nurses and a specialist worker screened medical and orthopaedic admissions to the York District Hospital. A cost-effectiveness analysis of screening data was carried out. Costs were measured by time taken to screen and the relative costs of employing different occupational groups. Effects included the screening rates of each occupational group and those identified as at risk. Results suggested a greater positive case identification rate could be achieved by employing a specialist worker, but at greater cost. The cost-effectiveness evaluation helps clarify the resource consequences of a screening programme and can be a useful aid in the decision-making process.

Can general practitioners counsel?

It has been suggested that general practitioners are in a prime position to counsel patients presenting with psychosocial problems. While many doctors use counselling skills in their consultations few have received training in counselling and the difference between the use of counselling skills and the process of counselling is not always understood. This paper examines the differences between counselling and counselling skills and compares the role of doctors and counsellors. It is concluded that there is a need for trained counsellors to work alongside general practitioners and that this is of benefit to patients and all members of the primary care team.

Doctors and alcohol screening--the gap between attitudes and action

The failure of doctors to identify patients who drink to excess has been attributed to inadequate education, negative attitudes towards problem drinkers and pessimism about treatment. As part of an early intervention programme at the York District Hospital, doctors were given brief alcohol education and encouraged to screen patients for alcohol problems. At subsequent evaluation doctors were well-informed about the nature and extent of alcohol problems and had positive attitudes to screening patients. Their performance did not reflect their views, however, with only 29 per cent of patients being screened. It is suggested that it is not unfavourable attitudes towards alcohol problems but doctors' perception of their role which determines their treatment of problem drinkers.

Abnormal gait sequence in locomotion after atropine treatment of catecholamine-deficient akinetic rats

Excessive, abnormal locomotion occurs after a high dose (25-50 mg/kg) of atropine sulfate to rats already akinetic due to catecholamine deficiency from intraventricular administration of 6-hydroxydopamine. This abnormal locomotion involves an abnormal gait sequence [right (R) hindleg (H), left (L) foreleg (F), LH, RF] instead of the normal gait sequence (RH, RF, LH, LF). In such animals atropine progressively (i) decreases hindleg step size, (ii) decreases arching of the trunk, and (iii) increases foreleg step size. These factors combine to change the ratio of front/hind body support. If the body stretches too far and the hindleg step is too small, a given hindleg step supports insufficient weight to remove weight from the ipsilateral foreleg; consequently, the opposite foreleg must execute the next step, producing the abnormal gait sequence. Thus, atropine affects gait sequence indirectly; it acts on at least three variables that affect how body weight is distributed and shifted during locomotion. To maintain stability during such locomotion, gait sequence is appropriately altered.

Stereotyped behavior and diabetes mellitus in rats: reduced behavioral effects of amphetamine and apomorphine and reduced in vivo brain binding of [3H]spiroperidol

Rats made diabetic with streptozotocin showed decreased stereotyped behaviors following administration of amphetamine or apomorphine. Spontaneous activity in an open field was lower in diabetics than in controls, but a low dose of apomorphine produced equivalent fractional decreases in activity in both groups. In vivo accumulation of amphetamine and apomorphine was generally similar in both groups: Reduced tissue access did not appear to be responsible for the decreased behavioral effects of these agents. The in vivo accumulation of spiroperidol in several brain regions was generally less in diabetics than in controls. These data are discussed in terms of altered catecholamine biochemistry and behavior in diabetics.

Effects of initial body weight on anorexia and tolerance to fenfluramine in rats

The initial anorexia and development of tolerance to dl-fenfluramine was examined in rats with graded pretreatment body weight losses. Fenfluramine strongly attenuated food intake on the first test day in all weight groups and the magnitude of the initial anorexia did not differ between groups. The time course of anorectic tolerance was also similar in each of the groups. The results do not support a strict "set point" hypothesis according to which the tolerance to fenfluramine anorexia is an artifact of decreasing body weight and/or concurrently increasing relative food deprivation.

Preference for high carbohydrate over various high fat diets by diabetic rats

Streptozotocin-diabetic male rats were hyperphagic relative to nondiabetic controls when offered only high carbohydrate (CHO) laboratory chow. Diabetics and controls ate about the same amount of high fat diets made from 67% w/w chow and 33% either coconut oil (saturated) or safflower oil (unsaturated). However, when offered a simultaneous choice of high fat diets and chow, nondiabetics and low dose (35 mg/kg) streptozotocin-diabetics showed a preference for the high fat diet: in contrast the high dose (65 mg/kg) streptozotocin diabetics developed a preference for chow. When pairs of isocaloric synthetic diets were offered, diabetics again preferred low fat/high CHO to high fat/low CHO diets, but the actual intake of fat was not constant across different diet pairs. Nondiabetics also selected away from the high fat diets in these synthetic diet pairs, even when saccharin was added to the high fat diet in an attempt to equate its sweetness with that of the paired low fat-high CHO diet. Plasma ketone levels of diabetics during obligatory high fat diet consumption were negatively correlated with their subsequent preference for the fat diet over simultaneously-offered chow. These data show that strong dietary preferences do not develop for fat in diabetics and suggest that high fat diets do not have net beneficial postingestional effects in these rats.

Voluntary exercise, food intake, and plasma metabolites in streptozotocin-diabetic Syrian hamsters

Diabetes mellitus was induced in Syrian hamsters by treatment with streptozotocin. The efficacy of and survival from this treatment are compared across several drug regimens, and in exercising versus sedentary hamsters. Stable diabetes, with plasma glucose levels typically below 400 mg/dl, is accompanied by a decrease of approximately 50% in voluntary wheel running in a 14L:10D cycle. Wheel running in diabetics is, however, almost completely abolished in continuous light. The diabetic hamsters are hyperphagic on chow, eating about 60% more than controls, exclusively by increasing the size of individual meals. Their intake is normalized on a high fat diet. The high fat diet greatly exacerbates the extant ketonemia in diabetics, and produces hypertriglyceridemia. Exercise has no apparent effect on plasma metabolic fuels of diabetic hamsters.

Failure of 2-deoxy-D-glucose to stimulate feeding in deermice

Deermice (Peromyscus maniculatus) did not increase their food intake above baseline following treatment with 2-deoxy-D-glucose (2DG, 500 or 1000 mg/kg). They did eat more following food deprivation or treatment with insulin at a high dose (100 U/kg). House mice (Mus musculus) showed hyperphagia to 2DG, low dose of insulin (5 U/kg) and deprivation.

Stereotyped behavior and diabetes mellitus in rats: Reduced behavioral effects of amphetamine and apomorphine and reduced in vivo brain binding of [–3H]spiroperidol

Rats made diabetic with streptozotocin showed decreased stereotyped behaviors following administration of amphetamine or apomorphine. Spontaneous activity in an open field was lower in diabetics than in controls, but a low dose of apomorphine produced equivalent fractional decreases in activity in both groups. In vivo accumulation of amphetamine and apomorphine was generally similar in both groups: Reduced tissue access did not appear to be responsible for the decreased behavioral effects of these agents. The in vivo accumulation of spiroperidol in several brain regions was generally less in diabetics than in controls. These data are discussed in terms of altered catecholamine biochemistry and behavior in diabetics.

Towards a rationalization of counselling in general practice

While there is good evidence to show that counselling may be beneficial to those patients in general practice with non-organic problems, deployment of the available resources lacks standardization and rationalization. The Counselling in Medical Settings Working Party of the British Association for Counselling is pressing for standardized training and accreditation of counsellors so that general practitioners will feel more confident about taking on workers who will ultimately be incorporated into the NHS team.

Metabolic fuel homeostasis in Syrian hamsters: nycthemeral and exercise variables

The food intake and growth of male and female golden hamsters, with and without access to running wheels, were measured under several conditions. These included different seasons, photoperiods and diets. Chow-fed males in wheels invariably had slowed weight gain and showed little hyperphagia relative to sedentary controls. One group of exercising female hamsters, fed high fat diet, grew faster than sedentary controls. The food intake of both exercising and sedentary groups was distributed evenly through the day/night cycle, but the exercising animals took smaller, more frequent meals at night. The nycthemeral variations in plasma glucose, triglycerides, free fatty acids and liver glycogen were quite small in sedentary hamsters. In exercising hamsters, however, liver glycogen was elevated in the late daytime and depleted in the mid-to-late night. In vivo lipogenesis rates in white and brown adipose and liver were elevated by day in the exercising compared to sedentary hamsters, and were lower at night in both groups. It appears that in exercising hamsters, and to a lesser extent sedentary hamsters, the day phase is one of inactivity and fuel storage, and the night phase is one of exercise and fuel mobilization.

Effects of chronic cold exposure on wheel running, food intake and fatty acid synthesis in Syrian hamsters

Mesocricetus auratus with established wheel running in a thermoneutral environment (23 degrees C) showed an immediate suppression of running when placed in a cold room at 4 degrees C. This suppression was seen in three separate studies and lasted at least 1 month. Food intake of these hamsters rose within 48 hr in the cold, and body weight was maintained. In contrast, hamsters which had been sedentary in the 23 degrees C room showed a slower rise in food intake in the cold and sustained a chronic drop in body weight. In vivo fatty acid synthesis rates were greatly elevated in white and brown adipose tissue, but not liver, of exercise versus sedentary hamsters after 1 month in the cold, despite the relative inactivity of both groups throughout the cold exposure. Previous exercise training predisposes hamsters to efficient energy storage in the cold. The energy demand of the cold environment may be responsible for the decreased voluntary running.

Metabolic fuel homeostasis in golden hamsters: effects of fasting, refeeding, glucose, and insulin

Experiments were conducted to investigate possible metabolic correlates of the unusual ingestive behavior of hamsters after food deprivation. A hypothesis of metabolic refractoriness predicts that hamsters, unlike rats, should not show changes in plasma metabolic fuels, adipose tissue, or liver after fasting and subsequent refeeding. This hypothesis was discredited by findings that fasted hamsters, like rats, have increased plasma ketones and free fatty acids and decreased liver glycogen. On refeeding, hamsters showed rapid reversal of these changes, with supranormal glycogen content and apparent fatty acid synthesis in liver. Additional studies examined the metabolic responses of hamsters and rats to exogenous insulin or glucose administration. Incorporation of 3H2O into liver fatty acids was greatly elevated in rats by both insulin and glucose, but in hamsters only insulin was effective. Some of these metabolic differences may help our understanding of the unusual refractoriness of hamster food intake to various stimuli.

Inhibition of gastric emptying by peripheral and central fenfluramine in rats: correlation with anorexia

Rats treated acutely with i.p. fenfluramine showed a profound inhibition of emptying of a chow meal from the stomach. This inhibition was attenuated by previous chronic treatment with fenfluramine. Tolerance to the gastric slowing occurred with as few as 2-4 prior injections, a time course which closely matches tolerance to the anorectic effects of the drug. Cerebroventricular injections of fenfluramine and norfenfluramine in anorectic doses also inhibited gastric emptying.

Anorexia and brain serotonin: development of tolerance to the effects of fenfluramine and quipazine in rats with serotonin-depleting lesions

The acute and chronic effects of the "serotonergic anorectics" quipazine and dl-fenfluramine were examined in rats with substantial and specific depletions of brain 5-hydroxytryptamine (5-HT) induced by 5,7-dihydroxytryptamine (5,7-DHT). A "dessert" test which did not involve food deprivation was used to assess anorexia. Markedly increased sensitivity to the L-5-HTP-induced behavioral syndrome in 5,7-DHT-lesioned rats indicated postsynaptic 5-HT receptor supersensitivity. We found low (2 mg/kg) and intermediate (5 mg/kg) doses of fenfluramine, a putative presynaptic agent, were more effective in producing anorexia in lesion rats versus controls. A higher dose of fenfluramine (10 mg/kg) was less effective in lesion rats, suggesting that high dose and low dose fenfluramine anorexia are mediated by different mechanisms. We found quipazine, a putative 5-HT postsynaptic agonist, in a dose range of 2-10 mg/kg, to be no more effective in producing anorexia in lesion rats compared to controls. The development of tolerance to both fenfluramine and quipazine anorexia was similar for lesion and control rats showing that an intact brain 5-HT system is not necessary for tolerance. Tolerance to the "behavioral syndrome" induced by high doses of these agents developed rapidly in controls but not at all in lesion rats. This suggests that the behavioral syndrome and anorexia are independent effects of fenfluramine and quipazine. These results also challenge the popular notion that the primary anorectic action of fenfluramine is via brain serotonin.

Drinking: a final common pathway?

Administration of either naloxone, an opioid antagonist (1 mg/kg i.p.), or clonidine, an alpha 2 adrenoceptor agonist (12 micrograms/kg i.p.), attenuated the dipsogenic responses of female rats to both angiotensin II (200 micrograms/kg s.c.) and isoproterenol (25 micrograms/kg s.c.). The effect of simultaneous administration of naloxone and clonidine at these submaximal doses was an additive attenuation of both angiotensin II- and isoproterenol-induced water intakes. The absence of a significant interaction between naloxone and clonidine to inhibit drinking suggests that they act by a similar mechanism. Yohimbine, an alpha 2 adrenoceptor antagonist (300 micrograms/kg i.p.), administered in combination with naloxone, reversed the antidipsogenic effect on angiotensin II-induced drinking. These results provide further support for a role for alpha 2-adrenoceptors in laboratory-induced drinking in rats, and suggest the possibility that the antidipsogenic effect of naloxone is related to alpha 2 adrenergic mechanisms. A model to support these observations is presented in which two separate pathways for the induction of drinking (osmoreceptor- and angiotensin II-induced) converge on a final common pathway. Since both naloxone and clonidine inhibit responses to stimulation of both pathways for drinking, these results suggest that their actions are likely to be at some point as yet undetermined on the final common pathway.

Nycthemeral variation in brain monoamines of Syrian hamsters: relation to activity and energy homeostasis

No significant time-of-day variations were found in whole brain content of various monoamines and metabolites of sedentary Syrian hamsters. In a second experiment, norepinephrine and serotonin levels in diencephalon were higher in the morning than the evening of both sedentary and voluntarily exercising hamsters. In telencephalon, levels of most transmitters were elevated in the evening, with the most dramatic rises in the metabolites 3,4-dihydroxyphenylacetic acid and 5-hydroxyindoleacetic acid. Again, in most instances, there was no difference between sedentary and exercise conditions.

Plasma metabolites after 2-deoxy-D-glucose in rats with brain dopamine-depleting lesions

Rats with selective brain dopamine-depleting lesions produced by 6-hydroxydopamine failed to increase their food intake after 2-deoxy-D-glucose administration. Their hyperglycemic response to 2DG was identical to that of intact controls. Neither group showed significant mobilization of free fatty acids or production of ketones.

Dietary self-selection in normal and diabetic rats after gastric loads of pure macronutrients

Rats which were experimentally diabetic (streptozotocin, 45 or 70 mg/kg, or pancreatectomized) and their nondiabetic controls were allowed to select ad lib from three pure macronutrient sources of carbohydrate (CHO), protein, and fat. After full adaptation, the intakes were examined 2, 4, 6, and 24 hr following an intragastric load given at the end of the daytime. Noncaloric (control) or isocaloric loads of CHO or protein or fat were studied. Fat loads suppressed subsequent fat intake reasonably selectively; CHO and protein loads suppressed the intake of the corresponding macronutrient, but less selectively. There were no major qualitative differences between diabetic and nondiabetic rats.

Effect of chronic administration of fenfluramine and quipazine on body weight gain after ovariectomy and on brain serotonin receptor binding

Chronic fenfluramine administration prevented excess weight gain following ovariectomy in rats but did not alter weight gain in sham-operated controls. Chronic quipazine treatment had no long-term effect on body weight. In one experiment, fenfluramine treatment for 28 days produced a 13% decrease in [3H]-serotonin binding to hypothalamic membranes and no change in [3H]-spiroperidol binding to striatum. In a second experiment, however, chronic fenfluramine had no effect on [3H]-serotonin binding to diencephalon. These results are discussed in terms of central and peripheral mechanisms of action and tolerance to fenfluramine.

Physiological and behavioral responses to glucoprivation in the golden hamster

Golden hamsters failed to increase their food intake following food deprivation alone or in combination with insulin or 2-deoxy-D-glucose (2DG) treatment. 2DG also failed to induce feeding in hamsters tested at night. In this latter experiment, there was no effect of 2DG on wheel running or general alertness. Insulin administration significantly decreased plasma levels of glucose and free fatty acids (FFA). 2DG treatment produced a dose-related hyperglycemia associated with increased ketone levels. These data are discussed in terms of cerebral energy status and its relation to food intake and physiological responses.

Different behavioral mechanisms underlie tolerance to the anorectic effects of fenfluramine and quipazine

Chronic administration of fenfluramine or quipazine before scheduled daily feeding sessions led to rapid and complete tolerance to the initial anorexia. Rats that received daily injections of fenfluramine after the daily meal also developed full tolerance. In contrast, quipazine administration after meals led to the development of little tolerance, indicating that quipazine tolerance appears to be learned or contingent. The implications of these data for neurochemical mechanisms of satiety are discussed.

Failure by deprived hamsters to increase food intake: some behavioral and physiological determinants

A series of experiments was performed to further understand the behavioral and physiological determinants of postfast anorexia in golden hamsters. Postfast anorexia and/or the failure to adapt to a feeding schedule was not restricted to a particular photoperiod condition or strain of hamster. The anorexia was also observed with a liquid diet, but hamsters were able to show large increases in water intake on a water deprivation schedule. When the animals were group housed, they pouched food during scheduled feeds and ate it later: Meal size was not increased. Measures of gastric fill and plasma metabolites indicated that filling and emptying of the forestomach may occur with a periodicity similar to that of spontaneous meals, and the data were consistent with strong peripheral satiation/satiety mechanisms in this species.

Differences among 'serotonergic' anorectics in a cross-tolerance paradigm: do they all act on serotonin systems?

Rats on a 4 hr/day feeding schedule showed anorexia after i.p. injections of several 'serotonergic' agents. Tolerance developed within a few days of daily administration of all drugs except fluoxetine. The tolerant animals were then given a cross-tolerance test with a different agent, either the next day or after a drug free washout period. Rats which were tolerant to quipazine or MK 212 showed no cross-tolerance to fenfluramine or norfenfluramine. In contrast, rats which were tolerant to fenfluramine showed good cross-tolerance to quipazine or MK 212. However, after a washout period between the end of the chronic fenfluramine regimen and the cross-tolerance test, quipazine regained its full anorectic potency. The development of tolerance to fenfluramine was dependent upon the number of injections, not on their spacing. Fenfluramine-tolerant animals showed a partial decay of tolerance after a 3 day washout, but still retained some tolerance after 12 days. These findings imply that the mechanisms underlying the development of tolerance may differ from those which mediate its maintenance. Our data further suggest that not all of the agents act on the same neural system(s), and raise the possibility that non-serotonergic and/or non-cerebral systems may be involved in the mode of action of these agents.

Naloxone suppresses insulin-induced food intake in novel and familiar environments, but does not affect hypoglycemia

The opiate antagonist naloxone reduced the food intake induced in rats by acute injection of insulin. The suppression was most marked in the first hour after insulin injection. Insulin provoked less food intake when rats were tested in a novel environment compared with those tested in their home cage, but naloxone again significantly suppressed the intake in the first hour. Naloxone had no effect upon insulin-induced hypoglycemia.

Effects of dopamine-depleting brain lesions on experimental hyperphagia in rats

Dopamine (DA)-depleting brain lesions of various sizes were produced in rats either by intracerebroventricular injections of 6-hydroxydopamine (6-HDA) or by electrolytic lesions of the lateral hypothalamic (LH) area. Among 30 animals that became aphagic and adipsic for at least four days after large LH or 6-HDA-induced brain lesions, only three developed hyperphagia after electrolytic lesions of the ventromedial hypothalamus (VMH) or daily injections of long-acting protamine-zinc insulin (PZI). In 20 rats with smaller LH or 6-HDA-induced lesions, which had not shown marked initial behavioral dysfunctions, only three gained as much weight after VMH lesions as the control animals. Similarly, 6 of 10 rats with smaller LH lesions could not tolerate a 15-day series of PZI treatments, although 14 of 17 rats with smaller 6-HDA-induced lesions increased their food intake and gained weight during the PZI treatments as did control animals. These results indicate that hypothalamic hyperphagia can be blocked by DA-depleting brain lesions that neither produce an initial period of aphagia and adipsia nor involve hypothalamic tissue. They further indicate that even small LH lesions may prevent the development of hyperphagia elicited by PZI, whereas only very large 6-HDA-induced lesions consistently have this effect.

Comparison of the suppression by naloxone of water intake induced in rats by hyperosmolarity, hypovolemia, and angiotensin

The effect of naloxone upon water consumption by rats was assessed using two intensities each of IV NaCl (Hyperosmolarity), SC polyethylene glycol (hypovolemia), and IV angiotensin II. In each case naloxone produced a dose-related reduction in the amount drunk. Angiotensin-induced drinking was most easily inhibited, and was abolished by only 1 mg/kg naloxone. In contrast, 1 mg/kg naloxone produced only a 50% reduction NaCl-induced drinking, and hypovolemia-induced drinking was not completely reversed by 5 mg/kg. Naloxone was without effect upon the natriuresis after NaCl, or the hypertension during AII administrations. Parallels are drawn between the effects of naloxone on these types of thirst, and of other perturbations including brain damage and taste adulteration.

Peripherally administered serotonin decreases food intake in rats

We report that intraperitoneal injection of serotonin produces a dose-related decrease in the food intake of hungry rats. The efficacy of serotonin was increased by prior treatment with clorgyline, a type A monoamine oxidase inhibitor. Doses of serotonin which were anorectic did not significantly impair locomotor activity or sensorimotor performance. Further, 2 mg/kg serotonin (ED50 on food intake) did not produce a conditioned taste aversion when paired repeatedly with sucrose ingestion. We conclude that the anorectic effects of serotonin are not secondary to nonspecific effects of the agent, and suggest that peripheral serotonin may play a role in normal satiation.

Morphine antagonists and consummatory behaviors

Opiate antagonists were tested for their effects upon either drinking or eating in eight experiments. Naloxone, nalorphine, and the active isomer of WIN 44,441 all reduce drinking. Neither an analog of nalorphine that does not cross the blood-brain barrier, nor the inactive isomer of WIN 44,441 is effective in reducing water intake. These data provide support for the conclusion that these antagonists ahve stereospecific effects within the central nervous system. Naloxone suppresses drinking following procedures inducing osmotic, volemic, or hormonal thirst. Naloxone suppresses eating following procedures inducing glucoprivation but does not alter eating elicited by tail-pressure. Collectively, these data lead to the conclusion that endorphins play a role in the organization of ingestive behavior following challenges to homeostasis.