The Cholesterol Content of the Serum in Mental Diseases

Within recent years a considerable amount of work has been done upon the bio-chemistry of cholesterol, and valuable information has been acquired which has thrown light upon the important part which this substance plays in numerous physiological and pathological states. It will be of value in connection with the results described in this paper to shortly review some of the more outstanding facts which have been discovered.

Spatial distribution of growth hormone receptor, insulin-like growth factor-I receptor and apoptotic chondrocytes during growth plate development

Linear bone growth depends upon proliferation, maturation, and apoptosis of growth plate chondrocytes, processes regulated by growth hormone (GH) and insulin-like growth factor-I (IGF-I). To investigate the contribution of GH, IGF-I and apoptosis to growth plate function, the expression of GH receptor (GHR) and IGF-I receptor (IGF-IR) mRNA were evaluated by in situ hybridization in fractionated costochondral growth plates of growing rats (at 2, 4, and 7 weeks). Apoptosis was determined by TUNEL assay and morphology in histological sections. GHR mRNA was greatest in resting cells with hypertropic cells increasing GHR expression with increasing age. Hypertropic and resting cell IGF-IR mRNA declined over the ages studied. Receptor mRNA expression was altered by exposing cells to GH or IGF-I. GH and IGF significantly decreased GHR mRNA in proliferative cells. GH and IGF also decreased IGF-IR mRNA in resting cells and the 2- and 4-week-old proliferative and hypertropic cells. Treating cells in culture with GH increased the number of apoptotic cells across all ages and zones. Histologically, apoptotic cells were observed at the chondro-osseous junction and within actively proliferating chondrocytes but not in resting cells. Apoptosis was highest at 4 weeks of age with lateral regions displaying the greatest number of cells undergoing apoptosis. These data indicate that apoptosis plays a role in growth plate function, particularly spatial configuration as indicated by the preferential lateral cell apoptosis. The susceptibility of proliferative cells to GHR and IGF-IR down regulation during the period of greatest apoptosis supports a role for the GH-IGF axis in both proliferation and apoptosis during growth plate development.

Evidence for quantitative trait loci affecting twinning rate in North American Holstein cattle

Twinning in dairy cattle has been associated with many negative health and reproductive events that cause economic loss to the producer. Reports have suggested that twinning rates are increasing and that there may be a positive relationship between milk production and twinning frequency. Putative quantitative trait loci (QTL) for twinning and ovulation rate on bovine chromosomes 5, 7, 19 and 23 have been previously identified in other populations. The objective of this study was to detect and possibly confirm the existence and effects of these QTL in the North American Holstein population. Half-sib families of 20 North American Holstein sires with above average twinning rate predicted transmitting abilities (PTA) comprised the sample population under investigation. Twinning rate PTA values had been estimated from calving data. DNA extracted from semen samples was analysed using 45-61 microsatellite markers across the four chromosomes. Marker heterozygosity of the patriarchs averaged 62%. Evidence of twinning QTL was found in multiple families on chromosomes 5, 7 and 23 and in one family on chromosome 19. Four of the sires formed one three-generation family: one sire and three half-sib sons with sons of their own. This extended family was analysed with additional markers confirming a twinning QTL of significant size on chromosome 5.

Jugular venous neurone-specific enolase and s-100 levels after carotid endarterectomy under local or general anaesthesia

Background

Previous studies using near infrared spectroscopy have indicated that carotid endarterectomy (CEA) performed under local anaesthesia (LA) preserves cerebral cytochrome oxidase and autoregulation compared with surgery under general anaesthesia (GA). The hypothesis that LA offers a degree of protection against ischaemic cerebral injury has thus been investigated by measuring ipsilateral jugular venous neurone-specific enolase (NSE; a glycolytic enzyme released from injured neurones) and s-100 (a protein released from glial cells) during and after CEA.

Methods

Sixteen patients with symptomatic 70–99 per cent carotid stenosis were randomized (with ethics committee approval) to CEA with either LA (n = 7; mean stump pressure 48·5 (range 37–80) mmHg; none of seven shunted) or GA (n = 9; mean stump pressure 49·1 mmHg; five of nine shunted). Jugular venous samples were assayed for NSE and s-100 concentration (immunoluminometric assay) before carotid clamping, 5 min before and 5 min, 2, 4, 6, 8, 12 and 24 h after clamp release.

Results

There were no neurological complications. Median (range) levels of s-100 were low and did not increase from baseline levels (GA 0·10 (0·08–0·11) μg l−1, LA 0·13 (0·12–0·17) μg l−1) in either group. Preclamp NSE levels were similar in both groups (LA 17·6 (15·2–20·7) μg l−1versus GA 21·5 (11·3–26·2) μg l−1; P = 0·37). Peak levels occurred at 2 h and were significantly higher in patients having GA (48·2 (31·4–61·3) versus 25·5 (16·6–27·8) μg l−1; P = 0·05, Mann–Whitney U test). Furthermore, the increase from baseline in patients having GA was also significant (P = 0·04) and NSE levels were higher at all time points up to 12 h, returning to baseline at 24 h.

Conclusion

These results suggest that CEA performed under LA is associated with reduced cerebral ischaemic injury compared with GA, and are consistent with niroscopic data indicating improved cerebral oxygenation in these patients. Furthermore, NSE would seem to be a more sensitive marker of cerebral injury than s-100.

Differences in cognitive function and S100 production after carotid endarterectomy under local or general anaesthetic

Background

Previous studies reported both improved (enhanced cerebral perfusion after carotid endarterectomy (CEA)) and diminished (intraoperative ischaemic injury) cognitive function (CF) following CEA. These studies were not adequately controlled for anxiety, general health and learning (repeated testing), and the influence of anaesthetic technique was not assessed.

Methods

This study assessed CF (trained psychologist, seven computerized tests) before operation, and at 5 and 90 days after CEA performed under local anaesthesia (LA) (n = 34) or general anaesthesia (GA) (n = 13). Similar measurements in patients undergoing lower limb revascularization (n = 14) and unoperated subjects with asymptomatic carotid stenosis greater than 70 per cent (n = 16) tested twice, 3 months apart, controlled for the effects of anaesthesia, surgery and carotid arteriosclerosis. Additionally, jugular venous S100 levels (neuronal protein released following cerebral injury) were measured (before carotid clamping, and 1, 4 and 24 h after clamp release) in 18 of these patients (nine LA, nine GA).

Results

Compared with controls, test performance in patients who had CEA under GA improved in one (executive CF 90 days; P = 0·028), but deteriorated in another (working memory 90 days; P = 0·038) while patients who had LA improved in three of seven tests (executive function, working memory) at 5 days (P = 0·03, 0·048, 0·036) and 90 days (P = 0·01, 0·05, 0·006). Further, a greater than 25 per cent improvement in one or more tests was more likely 90 days after CEA under LA (22 of 34 versus four of 13; P < 0·04) with improved executive function, speed and accuracy. S100 levels were lower after CEA under LA (1 h: 0 (0–30) versus 29 (8–98) µg ml−1, P < 0·05; 4 h: 0 (0–6) versus 22 (2–95) µg ml−1, P < 0·05; 24 h: 0 (0–1) versus 35 (14–77) µg ml−1, P < 0·01).

Conclusion

This study demonstrated improved CF following CEA under LA which was associated with lower jugular venous S100 levels (marker of cerebral injury). These differences may reflect improved cerebral oxygenation (preservation of cerebral autoregulation).

Indirect prediction of herd life in Guernsey dairy cattle

Production and type data were used to investigate the relationships of these traits with herd life data in US Guernsey cows that calved from 1985 through 1990. Two definitions of herd life were used: actual days from birth to disposal (true herd life) and herd life adjusted for milk production (functional herd life). Genetic parameters were calculated with data from cows that had an opportunity to reach 84 mo of age (n = 18,725). Linear type traits were preadjusted for stage of lactation and age at classification. True herd life was preadjusted for age at first calving and for functional herd life, within herd-year quartile ranking for milk yield. The (co)variance components for true and functional herd life, milk, fat, protein, and 15 linear type traits were estimated with multiple-trait REML in an animal model. Heritability estimates for true and functional herd life were 0.12 for both traits. Estimated genetic correlations of herd life with body size traits were from -0.14 to -0.29, with feet and leg traits were from -0.10 to 0.06, and with udder traits were from -0.09 to 0.24. These correlation parameters were used for indirect prediction of herd life from available production and type information in Guernseys.

Effects of pre and antenatal elevated and chronic oMt1a-oGH transgene expression on adipose deposition and linear bone growth in mice

Exposing growing oMtla-oGH transgenic mice with the regulatable metallothionein promotor to elevated growth hormone (GH) for three weeks after weaning enhances bone length and adipocyte differentiation. The objective of the present study was to investigate the consequences of highly elevated GH exposure during fetal and early postnatal growth periods on the mature phenotype. Transgene expression, hence elevated GH, was achieved in fetuses and neonates by providing 25 mM ZnSO4 to the drinking water of the dams. Wildtype and oMtla-oGH male and female mice were a) never exposed to the transgene stimulus, b) exposed from birth to 21 d of age, c) exposed through gestation until 21 d of age, d) exposed only through gestation, or e) exposed only during the first 7 d postpartum. At 84 d of age when mature body size was reached, ulna and humerus lengths, and body, liver gonadal fat pad, mesenteric fat pad, and cleaned gastrointestinal (GI) tract weights were recorded. Bone lengths were also determined in a subset of mice at 22 d of age. While early exposure to the elevated GH increased ulna and humerus length at 22 d of age, the early GH levels failed to produce significant changes in adipose content or bone lengths at maturity. However, chronic exposure to slightly elevated GH, as seen in the transgenics never induced to express the transgenic GH, depressed liver and GI weights and increased adipose depot weights and humerus lengths across both sexes. These results suggest that certain tissues in the body, while capable of responding to GH during early developmental periods, are not fully entrained to sustain that growth response once the GH stimulus is withdrawn. Further, the preadipocyte pool appears unable to respond to GH early in development. Finally, the tissues examined exhibited a differential response to the GH suggesting that different tissues possess distinct response thresholds.

Warfarin toxicity in the emergency department: recommendations for management

OBJECTIVE

To examine patients who presented to a hospital emergency department with evidence of warfarin toxicity, and to review the available published literature to determine what guidelines are available for management of this problem.

METHOD

A retrospective analysis of all adult patients who presented to The Geelong Hospital Emergency Department between 1 January 1996 and 30 June 1998 with international normalized ratio > 6 due to warfarin toxicity.

RESULTS

A total of 84 patients with international normalized ratio > 6 were included in the study. The average age was 68.3 years. Fifty-three per cent were women. The international normalized ratio was between 6 and 10 in 33 patients (39%), and greater than 10 in 51 patients (61%). Major bleeding occurred in 16.7% of patients, minor bleeding in 17.8%. Sixty-five per cent had no bleeding. Seven patients died, four of those with bleeding. Patients with an international normalized ratio > 10 were more likely to receive fresh frozen plasma (77.6% vs 28.6%; P < 0.001) and in greater amounts (3.0 units vs 0.8 units; P < 0.001) than those with an international normalized ratio of 6-10. There were also more episodes of major bleeding, although not significant. Patients with major bleeding were older (mean 75.4 years vs 67.5 years; P = 0.04), more likely to be admitted (P = 0.046), were more often given fresh frozen plasma (P = 0.003) and in greater amounts (3.28 units vs 2.0 units; P = 0.02).

CONCLUSION

Warfarin toxicity is a common problem, and variation in management is not surprising considering the lack of consensus in the literature on this topic. Current recommendations are summarized and a simple flowchart for management of this problem is provided.

Two domains of the epstein-barr virus origin DNA-binding protein, EBNA1, orchestrate sequence-specific DNA binding

The EBNA1 (for Epstein-Barr nuclear antigen 1) protein of Epstein-Barr virus governs the replication and partitioning of the viral genomes during latent infection by binding to specific recognition sites in the viral origin of DNA replication. The crystal structure of the DNA binding portion of the EBNA1 protein revealed that this region comprises two structural motifs; a core domain, which mediates protein dimerization and is structurally homologous to the DNA binding domain of the papillomavirus E2 protein, and a flanking domain, which mediated all the observed sequence-specific contacts. To test the possibility that the EBNA1 core domain plays a role in sequence-specific DNA binding not revealed in the crystal structure, we examined the effects of point mutations in potential hydrogen bond donors located in an alpha-helix of the EBNA1 core domain whose structural homologue in E2 mediates sequence-specific DNA binding. We show that these mutations severely reduce the affinity of EBNA1 for its recognition site, and that the core domain, when expressed in the absence of the flanking domain, has sequence-specific DNA binding activity. Flanking domain residues were also found to contribute to the DNA binding activity of EBNA1. Thus, both the core and flanking domains of EBNA1 play direct roles in DNA recognition.

Optical limiting with C(60) and other fullerenes

In view of a possible application in optical limiting devices for protection against laser radiation, at the Defence Research Establishment Valcartier we have studied the nonlinear transmission properties of fullerenes. The study involved C(60), C(70), C(76), C(84), several derivatives of C(60), and a variety of solvents. The nonlinear measurements were made with 7-ns pulses at 532 nm from a N-d:YAG laser. For optical limiting applications, solutions of C(60) yielded better results than the other fullerenes, with a solution of C(60) in chlorobenzene being marginally the best.

A comparative study of hypertension prevalence, awareness, treatment and control rates in St Lucia, Jamaica and Barbados

BACKGROUND

Cardiovascular diseases represent the most common cause of death in the English-speaking Caribbean, and hypertension represents the most important predisposing condition. However, direct between-country comparative studies in the Caribbean have not previously been undertaken.

OBJECTIVE

To obtain estimates of hypertension prevalence, awareness, treatment and control in three countries in the Caribbean.

DESIGN

Population-based samples of adults aged 25-74 years in St Lucia, Barbados and Jamaica were surveyed regarding their cardiovascular health and their blood pressures were measured using a highly standardized protocol. A reference site was available from a collaborative study among blacks in metropolitan Chicago, Illinois, USA.

RESULTS

At the 160/95 mmHg threshold, age-adjusted hypertension prevalence estimates for Jamaica, St Lucia and Barbados were 17.5, 18.3 and 21.5%, respectively, and 24.7, 26.9 and 27.9%, respectively, at the 140/90 mmHg threshold. The corresponding estimate for the Chicago site at the 140/90 mmHg threshold was 33.2%. The gradient in prevalence resembled the gradient in body mass index (25.7 kg/m2 in Jamaica to 29.3 kg/m2 in the USA). At the 160/95 mmHg threshold, the proportion of all hypertensives who were aware of their disease, pharmacologically treated and controlled was highest in Barbados (90, 85 and 72%, respectively) and lowest in St Lucia (74, 59 and 35%, respectively). Men, particularly those aged less than 55 years, were less likely to have their hypertension treated and controlled.

CONCLUSIONS

Compared with estimates from earlier independent surveys, considerable progress has been made in hypertension detection and control in these countries, which should lead to sizable reductions in the burden of cardiovascular disease.

Making the IT (information technology) jigsaw fit

Providers will need good information systems to survive in the internal market. In the first of the Journal's regular special features on computing (to appear in the last week of every month) we examine the strategic issues facing hospital managers investing in information technology, and look at two very different approaches to harnessing IT--one of which is a sophisticated hospital management package, the other a rough and ready early warning system.

Developing a hospital nursing research program

Including nursing research as a stream in the nursing career structure in Western Australia paved the way for development of the Nursing Research Department at Sir Charles Gairdner Hospital. Over the last two years a program of research activities has been introduced to assist nurses to evaluate their practice, to critique the research and apply its results in patient care.

Steps to a milestone

Information systems need urgent upgrading if hospitals are to become successful providers of services after April 1991. Guy Palmer, Vic Peel and John Cruickshank advise how to prepare.

Arousal deficit: mechanism of the sudden infant death syndrome?

Polygraphic tracings of 13 normal infants were recorded in a morning sleep at 1 and 2 weeks of age and 1, 2, 3, 4, and 6 months of age. A vibrotactile stimulus graded at 25, 50 and 100 Hz (frequency) and amplitudes of 1, 2 and 3 mm (intensity) was used, each combination being applied twice at 30 s intervals to the hand of the sleeping infant during active sleep (AS) and quiet sleep (QS). The results were analysed as percentages of failure to arouse (FTA) in relation to the number of stimulus trials, the criteria for FTA being the absence of a response in heart or respiratory rate, electroencephalogram, or chin electromyogram. The percentages of FTA from QS did not change significantly from 1 week to 6 months of age, irrespective of frequency or intensity. The percentages of FTA from AS fell sharply and significantly from 1 week to 2 months of age (P less than 0.001). At 3 months of age there was a significant increase followed by a significant decrease at 4 months of age, both changes showing a significant difference at P less than 0.05. Apart from the first week of age, the numbers of FTA from QS were greater than from AS for all stimulus trials. It is concluded that there is an arousal deficit in QS from 1 week to 6 months of age and the temporary deficit in AS at 3 months of age could explain the peak incidence of SIDS at this time.

Reflectance characteristics of selected materials for reference targets for 10.6-microm laser radars

The reflective characteristics of several materials have been examined in an effort to develop a 10.6-microm reflectivity standard for field measurements with laser radars. Measurements on twelve different target materials showed that many materials have components of diffuse reflectivity, specular reflectivity, and retroreflectivity. For each material examined, both the effective Lambertian reflectivity and the beam depolarization were determined. It was also found that because of the strong retroreflection component present with many materials, the practice of estimating the effective diffuse reflectivity from measurements of total reflectivity could lead to erroneous reflectivity values for laser radar systems. One of the preferred reference targets found for 10.6-microm field measurements was canvas tarpaulin.

Beta-blockers, plasma total creatine kinase and creatine kinase myocardial isoenzyme, and the prognosis of subarachnoid hemorrhage

Under double-blind randomized conditions the effects of early intervention with oral propranolol or a placebo were studied in 51 cases of subarachnoid hemorrhage. Eleven out of 23 patients randomly assigned to placebo had a poor outcome at 6 months, while 2 of the 28 patients randomly assigned to propranolol had a poor outcome (p less than 0.001). Patients with a poor outcome on the placebo had significantly higher mean plasma total creatine kinase levels (742 IU, standard error of the mean +/- 233 IU) on the fifth day after subarachnoid hemorrhage than patients with a good outcome on the placebo (108 +/- 20 IU; p less than 0.05). A raised plasma creatine kinase myocardial isoenzyme was associated with a particularly poor outlook in patients receiving the placebo, in contrast to those taking a beta-blocker. Clinical outcome and plasma creatine kinase levels in patients taking atenolol (hydrophilic) were similar to those observed in patients receiving propranolol.

A prospective controlled study of the effect on blood pressure of contraceptive preparations containing different types and dosages of progestogen

A prospective controlled study investigated the effects of oral contraceptives on blood pressure in 485 women who were between 17 and 46 years of age and had blood pressures of less than 140/90 mmHg at entry. The women were divided into seven groups depending on the chosen method of contraception: intrauterine device or barrier method (control group): ethinyl oestradiol 30 micrograms plus levonorgestrel 150 micrograms (Microgynon-30 or Ovranette); norethisterone 350 micrograms (Micronor); norgestrel 75 micrograms (Neogest); norethisterone oenanthate 200 mg intramuscularly every 2 months for the first 6 months, then every 3 months thereafter; ethinyl oestradiol 30 micrograms plus ethynodiol diacetate 2 mg (Conova-30); and ethynodiol diacetate 500 micrograms (Femulen). Blood pressures were measured every 3 months by the family planning clinic nurse under standardized conditions using an Elag-Köln automatic sphygmomanometer. After one year, blood pressure had risen significantly (P less than 0.05) in the 137 women taking ethinyl oestradiol plus levonorgestrel (mean systolic and diastolic rises 6.4 and 2.7 mmHg respectively) and in the 91 women taking ethinyl oestradiol plus ethynodiol diacetate (mean systolic and diastolic rises 6.2 and 3.0 mmHg respectively). The 94 women taking the progestogen-only preparations and the 143 women in the control group showed no increases in blood pressure. These data were confirmed after 2 years of follow-up.

Antenatal detection of recurrence of Majewski dwarf (short rib-polydactyly syndrome type II Majewski)

Two cases of Majewski dwarfism are reported. both were the product of the same non-consanguinous marriage and each exhibited the key features of this syndrome: polysyndactyly, short ribs, cleft lip, disproportionately short tibiae and a normal pelvis. The first infant, a baby boy, died shortly after birth, whilst the second was detected prenatally by ultrasound and had female characteristics. Several skeletal dysplasias have been demonstrated in utero by ultrasound, but we believe this to be the first reported case of a Majewski dwarf detected by this method. In view of the difficulty in diagnosis of this syndrome comparison is made with other short rib-polydactyly syndromes.

Cardiac sequelae of acute head injury

An intensive 72 hour study of the cardiovascular effects of severe diffuse brain injury was made in seven patients. No other major injury was present. Patients received optimal care very rapidly after injury and intracranial pressure, which was continuously monitored, was maintained at or just above normal by elective positive pressure ventilation techniques. Three patients showed evidence of progressive myocardial ischaemia on continuous electrocardiographic monitoring. Two of these patients died. Ventricular arrhythmias were uncommon but one of the patients with ischaemia developed ventricular tachycardia. Heart rate patterns were very abnormal but did not predict complications. Blood pressure did not vary greatly and cardiac outputs were usually normal. Pronounced excesses of urinary catecholamines and serum creatine kinase 2 isoenzyme (CK MB) as well as total creatine kinase were found. Histological evidence of myocardial damage could be shown at necropsy in the one case whose heart was available for study. This study shows that the cardiac effects of isolated diffuse cerebral injury may be harmful and even fatal despite correction of secondary factors such as anoxia and raised intracranial pressure. The findings suggest that evaluation of the potential benefits of sympathetic blockade is warranted. Cardiac complications of cerebral damage deserve wider recognition by intensive care personnel, neurologists, and neurosurgeons.