The paradox of spring: Thyroid and glucocorticoid responses to cold temperatures and food availability in free living Carneddau ponies

In seasonal environments, maintaining a constant body temperature poses challenges for endotherms. Cold winters at high latitudes, with limited food availability, create opposing demands on metabolism: upregulation preserves body temperature but depletes energy reserves. Examining endocrine profiles, such as thyroid hormone triiodothyronine (T3) and glucocorticoids (GCs), proxies for changes in metabolic rate and acute stressors, offer insights into physiological trade-offs. We evaluated how environmental conditions and gestation impact on faecal hormone metabolites (fT3Ms and fGCMs) from late winter to spring in a free-living population of Carneddau ponies. Faecal T3Ms were highest in late February and March, when temperatures were lowest. Then, fT3Ms concentrations decreased throughout April and were at the lowest in May before increasing towards the end of the study. The decline in fT3M levels in April and May was associated with warmer weather but poor food availability, diet diversity and diet composition. On the other hand, fGCM levels did not display a clear temporal pattern but were associated with reproductive status, where pregnant and lactating females had higher fGCM levels as compared to adult males and non-reproductive females. The temporal profile of fT3Ms levels highlights metabolic trade-offs in a changing environment. In contrast, the ephemeral but synchronous increase in fGCM concentrations across the population suggest a shared experience of acute stressors (i.e., weather, disturbance or social). This multi-biomarker approach can evaluate the role of acute stressors versus energy budgets in the context of interventions, reproduction, seasonality and environmental change, or across multiple scales from individuals to populations.

Emotion recognition and eye tracking of static and dynamic facial affect: Acomparison of individuals with and without traumatic brain injury

Diminished social functioning is often seen after traumatic brain injury (TBI). Mechanisms contributing to these deficits are poorly understood but thought to relate to impaired ability to recognize facial expressions. Static stimuli are often used to investigate ability post-TBI, and there is less evidence using more real-life dynamic stimuli. In addition, most studies rely on behavioral responses alone. The present study investigated the performance of a TBI group and matched non-TBI group on static and dynamic tasks using eye-tracking technology alongside behavioral measures. This is the first study to use eye tracking methodology alongside behavioral measures in emotion recognition tasks in people with brain injury. Eighteen individuals with heterogeneous TBI and 18 matched non-TBI participants were recruited. Stimuli representing six core emotions (Anger, Disgust, Fear, Happy, Sad, and Surprise faces) were selected from the Amsterdam Dynamic Facial Expression Set (ADFES). Participants were instructed to identify the emotion displayed correctly whilst eye movement metrics were recorded.

RESULTS

Results of analyses showed that TBI patients had First Fixation to nose for all emotion stimuli, shorter Fixation Duration and lower Fixation Count to eyes, were generally slower to classify stimuli, and less accurate than non-TBI group for the static task. Those with TBI were also less accurate at identifying Angry, Disgust, and Fear stimulus faces compared to the non-TBI group during the dynamic unfolding of an emotion.

CONCLUSION

In the present study, those with TBI had atypical eye scan patterns during emotion identification in the static emotion recognition task compared to the non-TBI group and were associated with lower identification accuracy on behavioral measures in both static and dynamic tasks. Findings suggest potential disruption to oculomotor systems vital for first stage perceptual processing. Arguably, these impairments may contribute to diminished social functioning.

Investigating the 'latent' deficit hypothesis: age at time of head injury, implicit and executive functions and behavioral insight

This study investigated the 'latent deficit' hypothesis in two groups of head-injured patients with predominantly frontal lesions, those injured prior to steep morphological and corresponding functional maturational periods for frontal networks (<or=age 25), and those injured>28 years. The latent deficit hypothesis proposes that early injuries produce enduring cognitive deficits manifest later in the lifespan with graver consequences for behavior than adult injuries, particularly after frontal pathology (Eslinger, Grattan, Damasio & Damasio, 1992). Implicit and executive deficits both contribute to behavioral insight after frontal head injury (Barker, Andrade, Romanowski, Morton, & Wasti, 2006). On the basis of morphological and behavioral data, we hypothesized that early injury would confer greater vulnerability to impairment on tasks associated with frontal regions than later injury. Patients completed experimental tasks of implicit cognition, executive function measures and the DEX measure of behavioral insight (Behavioral Assessment of the Dysexecutive Syndrome: Wilson, Alderman, Burgess, Emslie, & Evans, 1996). The Early Injury group were more impaired on implicit cognition tasks compared to controls that Late Injury patients. There were no marked group differences on most executive function measures. Executive ability only contributed to behavioral awareness in the Early Injury Group. Findings showed that age at injury moderates the relationship between executive and implicit cognition and behavioral insight and that early injuries result in long-standing deficits to functions associated with frontal regions partially supporting the latent deficit hypothesis.

Implicit cognition is impaired and dissociable in a head-injured group with executive deficits

Implicit or non-conscious cognition is traditionally assumed to be robust to pathology but Gomez-Beldarrain et al. recently showed deficits on a single implicit task after head injury. Laboratory research suggests that implicit processes dissociate. This study therefore examined implicit cognition in 20 head-injured patients and age- and IQ-matched controls using a battery of four implicit cognition tasks: a serial reaction time task (SRT), mere exposure effect task, automatic stereotype activation and hidden co-variation detection. Patients were assessed on an extensive neuropsychological battery, and MRI scanned. Inclusion criteria included impairment on at least one measure of executive function. The patient group was impaired relative to the control group on all the implicit cognition tasks except automatic stereotype activation. Effect size analyses using the control mean and standard deviation for reference showed further dissociations across patients and across implicit tasks. Patients impaired on implicit tasks had more cognitive deficits overall than those unimpaired, and a larger dysexecutive self/other discrepancy (DEX) score suggesting greater behavioural problems. Performance on the SRT task correlated with a composite measure of executive function. Head injury thus produced heterogeneous impairments in the implicit acquisition of new information. Implicit activation of existing knowledge structures appeared intact. Impairments in implicit cognition and executive function may interact to produce dysfunctional behaviour after head injury. Future comparisons of implicit and explicit cognition should use several measures of each function, to ensure that they measure the latent variable of interest.

Use of topical negative pressure therapy in postoperative dehisced or infected wounds

Animal and case studies suggest that topical negative pressure for subacute wounds can increase angiogenesis and local blood flow and reduce bacterial counts, but clinical trials into the technique have yet to be conducted.

Remifentanil vs fentanyl/morphine for pain and stress control during pediatric cardiac surgery

BACKGROUND

Remifentanil is a short acting, potent synthetic opioid that does not accumulate after infusion or repeated bolus doses. It may be rapidly titrated to the requirements of individual patients. Titrated infusion of remifentanil may be able to provide potent analgesia required for pediatric cardiac surgery and obtund the stress response in theater whilst not having the persistent respiratory depression and sedation seen with longer acting opioids.

METHODS

Twenty patients were randomized to receive a titrated infusion of remifentanil (0-1 microg x kg(-1) x min(-1)) or a standard dose of fentanyl (30 microg x kg(-1)) prebypass plus morphine (1 mg x kg(-1)) on rewarming. Blood samples for glucose and cortisol were taken at regular intervals from induction through bypass and into the first 24 h of postoperative intensive care. In addition to biochemical indicators of the stress response we recorded baseline hemodynamic parameters and any acute physiological events.

RESULTS

Ten patients received morphine, seven received remifentanil. There were no statistically significant differences between the two treatment groups in cortisol measurements, mean arterial pressure or heart rate recordings. In the last time period the remifentanil group had a larger rise in blood glucose concentration (baseline 3.9, rise 3 mmol x l(-1)) than the fentanyl/morphine group (baseline 4.2 rise 1.9 mmol x l(-1)), CI -4.3 to -0.2.

CONCLUSIONS

The only significant difference was in glucose in the postbypass time periods. Although statistically significant, this difference is insufficient evidence of increased stress in the remifentanil group. The results show that in the patients studied there was no clinically important difference between the two techniques.

The evaluation of liquid-based 'Cyto-SED' cytology of bronchioalveolar lavage specimens in the diagnosis of pulmonary neoplasia against conventional direct smears

Historically, bronchioalveolar lavage (BAL) samples have been prepared by a direct smear (DS) technique. Recent advances in liquid-based cytology have led to a revolution in cytological specimen preparation. Cyto-SED system (CS) is a manual liquid-based cytology system, designed for small-scale use. A total of 137 samples from patients with radiographically detectable lesions underwent BAL procedures at Papworth Hospital NHS Trust over a 4-month period. After preparation for diagnostic purposes with the DS method, the remaining sample was prepared using the CS system. The slides produced were allocated a blind study number and screened by three independent screeners. The cellular morphology was well preserved and comparable between both techniques. Of the 137 patients, 38% were confirmed as malignant by cytology or histology; 71% of these malignant diagnosis were confirmed by the DS technique and 91% confirmed by the CS. The results demonstrate that the CS is a viable alternative to the DS technique. The cytological detail is clearly defined without a loss of three-dimensional information, thus aiding the differential diagnosis of malignancy. Cyto-SED cytology system yields a higher diagnostic accuracy than the conventional direct smear technique without compromising on cytological detail.

The addition of antiemetics to the morphine solution in patient controlled analgesia syringes used by children after an appendicectomy does not reduce the incidence of postoperative nausea and vomiting

BACKGROUND

We studied the effect of intraoperative ondansetron 0.1 mg x kg(-1) or droperidol 0.01 mg.kg-1, followed by the same dose of the antiemetic agent added to the morphine solution during patient controlled analgesia (PCA) on the incidence of nausea and vomiting in children following an appendicectomy.

METHODS

Sixty children, aged 5-13 years, were recruited and randomly allocated to receive no prophylactic antiemetic, the control group (group C), ondansetron (group O) or droperidol (group D). The PCA pump was programmed to deliver a bolus dose of 20 microg x kg(-1) of morphine.with a 5-min lockout period and a background infusion of 4 microg x kg(-1) x h(-1).

RESULTS

Postoperatively, the three groups were compared for nausea, vomiting and sedation scores for 24 h. The incidence of postoperative nausea and vomiting was 33% for group C, 44% for group O and 41% for group D. There was no increase in sedation scores in the droperidol group.

CONCLUSIONS

We were unable to show any significant benefit from the prophylactic administration of ondansetron or droperidol to children using morphine PCA devices following appendicectomy in the doses we employed.

Hardy-Weinberg quality control

An efficient test of deviation from Hardy-Weinberg frequencies with one degree of freedom was applied to 44 marker loci in a genome scan, and 7 loci had a significant excess of apparent homozygotes (chi2 (1) > 6) suggestive of typing error. In this example evidence for linkage did not increase when outliers were censored. Statistical quality control is an essential part of genotyping, and the effect of mistyping and map error should be considered in evaluating any genome scan.

Mistreatment due to weight: prevalence and sources of perceived mistreatment in women and men

OBJECTIVE

Previous research has documented prejudicial attitudes and discrimination against overweight people. Yet the extent to which overweight people themselves perceive that they have been mistreated because of their weight has not been carefully studied. The purpose of this study was to examine the prevalence of perceived mistreatment due to weight and sources of perceived mistreatment.

METHODS AND PROCEDURES

A non-clinical sample of healthy adults (187 men and 800 women) enrolled in a weight gain prevention program comprised the study population. A self-administered questionnaire was used to measure perceived mistreatment due to weight.

RESULTS

Overall, 22% of women and 17% of men reported weight-related mistreatment. The most commonly reported sources of mistreatment among women were strangers (12.5%) and a spouse or loved one (11.9%). Men were most likely to report mistreatment by a spouse or loved one (10.2%) and friends (7.5%). Somewhat surprisingly, sex differences in perceived weight-related mistreatment were significant only for stranger as the source. Perceived weight-related mistreatment was positively associated with body mass index (BMI) (r = 0.39, p<0.0001). Reported mistreatment was nearly ten times as pervalent among individuals in the highest quartile of the BMI distribution (42.5%) than among those in the lowest BMI quartile (5.7%), but was significantly greater than zero in all but the very lean.

DISCUSSION

Perceived mistreatment due to weight is a common experience and is not restricted to the morbidly obese. Results are discussed in light of the sociocultural value for thinness.

Microdeletions in FMR2 may be a significant cause of premature ovarian failure

Genetic causes of premature ovarian failure (POF) include X chromosome deletions and fragile X (FRAXA) premutations. While screening a cohort of women with POF for FRAXA premutations, a more distal trinucleotide repeat, FRAXE, was also tested. We found an unexpected excess of FRAXE alleles with apparently fewer than 11 repeats in the POF group. However, sequence analysis of these alleles showed that the excess was caused by three females who carry cryptic deletions in FMR2, the gene associated with FRAXE. We propose that microdeletions within FMR2 may be a significant cause of premature ovarian failure, being found in 1.5% of women with the condition, and in only 0.04% of the general female population. The deletions may affect transcription of either FMR2 or an adjacent gene.

Association between - 308 tumour necrosis factor promoter polymorphism and bronchial hyperreactivity in asthma

BACKGROUND

Tumour necrosis factor (TNF) is a pivotal cytokine in the inflammation underlying asthma. The TNF gene is located in the polymorphic HLA class 3 region on chromosome 6p. Several polymorphisms in this region have been described and associated with alteration of TNF secretion in vitro.

OBJECTIVE

In this study we tested the hypothesis that two such polymorphisms, lymphotoxin alpha NcoI B*1 and -308 TNF2 may be components of the genetic predisposition to asthma.

METHODS

Five hundred and fifty-six random individuals were studied, comprising approximately equal numbers of asthmatic subjects, with or without atopy, and a nonatopic nonasthmatic control group. In addition, 355 subjects (172 asthmatics) from 60 multiplex families were typed at the LTalpha NcoI locus.

RESULTS

There was an association between allele two of the -308 TNF polymorphism and bronchial hyperreactivity (OR 2.12, 95% CI 1.04-4.32, P = 0.036). However, there was no association with LTalpha NcoI alleles. To determine whether this was influenced by linkage disequilibrium within the MHC, 91 subjects with bronchial hyperreactivity and 85 control subjects were typed for class 2 and 3 alleles. Following identification of the extended TNF2 haplotype, we found no independent association of these alleles with BHR.

CONCLUSIONS

We conclude that the -308 TNF2 promoter polymorphism may form a component of the genetic predisposition to BHR in asthma.

Candidate gene and mutational analysis in asthma and atopy

BACKGROUND

Using quantitative phenotype scores, we have genotyped four markers close to the FcepsilonRI-beta gene on chromosome 11q and 17 markers on chromosome 12. We have also determined the frequency of the I181L/V183L and E237G polymorphisms in our population.

METHODS

131 randomly ascertained families and 109 families with an asthmatic proband were recruited. Written and video questionnaires, bronchial challenge, and skinprick tests were administered and IgE levels measured. Phenotype scores were derived using principal-component analysis. The asthma score incorporated the questionnaire data reduced to two variables (wheeze and video), the ratio of predicted to observed FEV1, and bronchial hyperresponsiveness calculated as the slope of the dose-response curve. Total IgE, with the highest heritability of the atopy variables, was used as the atopy score. I181L/V183L polymorphism was determined by sequencing and E237G polymorphism by the amplification refractory mutation system. The data were analyzed using the BETA programme.

RESULTS

No examples of the I181L/V183L polymorphism were identified. The E237G polymorphism was identified with a frequency of 3.5% with weak evidence for linkage (lod 1.522) to asthma. Linkage was found to markers on chromosome 12 and asthma. The largest single locus lod was achieved for D12S366 and wheeze (lod 3. 307). Using multipoint analysis, a maximum lod score of 2.29 centres around D12S97 at location 173.5 cM for the asthma score.

CONCLUSION

The linkage results for chromosome 12 justify further interest in this region. Future endeavours will be directed towards fine mapping in the hope of identifying novel candidate genes.

A new cancer education mission: managed care and clinical trials

BACKGROUND

The traditional support for clinical research, teaching, and indigent patient care is being seriously compromised by the growth of managed care in the United States. Educational initiatives are needed to ensure the incorporation of clinical trials into the optimal care of cancer patients.

METHODS

The Cancer Clinical Trials Task Force of Colorado was established in 1995 to find a collaborative and non-legislative solution to the uncertainty of coverage by third-party payers for cancer patients participating in clinical trials.

RESULTS

This program has served to heighten the awareness of the crucial role of clinical trials in defining new treatment strategies among third-party payers.

CONCLUSIONS

The Task Force and similar regional and national efforts have begun to provide needed information and education about the importance of clinical trials to the managed care industry; however, much remains to be done to ensure access to and coverage for clinical trials.

Limb girdle muscular dystrophy type 2A (CAPN3): mapping using allelic association

Recently a graphical study of linkage disequilibrium around the CAPN3 locus failed to refine the 1.3-Mb interval suggested by haplotype sharing. On the contrary, the Malecot model as implemented in the ALLASS program maps CAPN3 within 3 kb of its true location (23 kb from the locus midpoint), overcoming identified problems with small samples, interrelated sibships, and short duration.

Theory and observation of attachment and its relation to child maltreatment: a review

OBJECTIVE

The aim of this paper was to review the literature on attachment and child maltreatment in relation to the intergenerational transmission of maltreatment.

METHOD

A review of the literature to date was undertaken, and a descriptive analysis of 13 studies on the quality of attachment in maltreated samples was conducted.

RESULTS

Quality of infant attachment seems to be in the most part dependent upon the sensitiveness of the mother. Not surprisingly the majority of studies demonstrates that on average maltreated children are less securely attached to their mothers than nonmaltreated children. This early mother-infant relationship is said to be internalized by the child and consequently form a prototype to which all future relationships are assimilated. Thus maltreated children may have problems forming relationships with peers, partners and their own children.

CONCLUSIONS

It is suggested that this is the primary process by which maltreatment continues from one generation to the next. The implications of this process for the prediction and prevention of childhood maltreatment are discussed.

Linkage of asthma to markers on chromosome 12 in a sample of 240 families using quantitative phenotype scores

We present evidence of linkage between markers on chromosome 12 and asthma using the BETA program for nonparametric single- and multipoint linkage analysis. We have used quantitative scores as our phenotypic variables, combining data into indices for asthma and atopy and maximizing heritability. The largest single-locus LODs were achieved for asthma: D12S342 and asthma score (LOD 2.255), D12S324 and asthma affection (LOD 2.214), and D12S366 and wheeze (LOD 3.307). The region of interest identified using multipoint analysis, with a maximum LOD of 2.29, centers around D12S97 at location 173.5 cM with a standard error of 6.5 for the asthma score and close agreement for asthma affection and wheeze. Such evidence merits further investigation of this area in an attempt to define the region with greater precision with a view to identifying candidate genes. We hope that the methods presented will encourage researchers to use phenotypic information in a way that encourages meta-analysis.

Consumer preferences in format and type of community-based weight control programs

PURPOSE

The purpose of this study was to provide further information about preferences for types and formats (e.g., correspondence vs. face to face) of eating and exercise programs, actual participation rates in a variety of offered programs, and characteristics of program participants vs. nonparticipants.

DESIGN

Over a 3-year period, a large sample of community volunteers was given the opportunity to participate in various forms of diet and exercise programs as part of a weight gain prevention study.

SETTING

The study was conducted at a university and three local health department sites.

SUBJECTS

Subjects in the study were 616 individuals participating in the Pound of Prevention study (POP), a 3-year randomized evaluation of an intervention for preventing weight gain.

MEASURES

The primary outcomes assessed were participation rates for each program offering. Program participants were also compared to those who did not participate on demographic characteristics, smoking, diet behavior, exercise behavior, and weight concern.

RESULTS

Survey results indicated that correspondence formats for delivery of health education programs were rated as more desirable than face-to-face formats. Participation for program offering ranged from 0 to 16% of the study population. Participation data were consistent with survey results and showed participants' preference for correspondence formats even more strongly. Program offering attracted health-conscious participants with higher education and income levels.

CONCLUSIONS

These data suggest that some community members will get interested and take part in low-cost, minimal contact programs for exercise and weight control. Future research efforts should focus on investigating ways to increase participation in brief or minimal contact programs, particularly among groups that may be difficult to reach and at high risk for the development of obesity.

Non-disjunction of chromosome 18

A sample of 100 trisomy 18 conceptuses analysed separately and together with a published sample of 61 conceptuses confirms that an error in maternal meiosis II (MII) is the most frequent cause of non-disjunction for chromosome 18. This is unlike all other human trisomies that have been studied, which show a higher frequency in maternal meiosis I (MI). Maternal MI trisomy 18 shows a low frequency of recombination in proximal p and medial q, but not the reduction in proximal q observed in chromosome 21 MI non-disjunction. Maternal MII non-disjunction does not fit the entanglement model that predicts increased recombination, especially near the centromere. Whereas recent data on MII trisomy 21 show the predicted increase in recombination proximally, maternal MII trisomy 18 has non-significantly reduced recombination. Therefore, chromosome-specific factors must complicate the simple model of susceptible chiasma distributions interacting with age-dependent deterioration of the meiotic mechanism. For chromosome 18, 30% of tetrads are nullichiasmate in maternal MI non-disjunction, but nullichiasmates are not observed in maternal MII non-disjunction. Chiasma distributions from normal chromosome 18 meioses provide no evidence for normal disjunction from nullichiasmate tetrads. We extend this study to examine the remaining autosomes and find no evidence for normal disjunction from nullichiasmate tetrads generally.

Leg ulceration and ethnicity: a study in west London

Little is known of the influence race has on the development of leg ulceration, with most studies being performed in almost exclusively white populations. As part of a wider audit of leg ulcer services, health care professionals were contacted to give details of age, sex and ethnic background of all patients who attended for treatment of leg ulceration over a one year period in an area of west London. West London Health Care Trust provides services to a population of 275,000 of whom 53,000 have an ethnic background from the Indian subcontinent (South Asian). In all, 280 patients were identified, of whom 264 (94%) had details of age and sex. This gave a crude ascertainment rate of 1.02 per 1000 population. Of the 264 patients, five were classified as South Asians, with one patient classified as Afro-caribbean. The Mantel Haenzsel test demonstrated a significantly higher proportion of whites suffering from leg ulceration than South Asians, giving an odds ratio of 4.43, with 95% confidence intervals between 1.94 and 10.13 (P = 0.0004). The expected frequency of South Asian patients should be 23, based on rates from the white population, of which 13 would be women and 10 men. Only five South Asian men were identified, and no Asian women with leg ulceration. Reasons for this low ascertainment are two-fold. Either there is a real difference between the white and South Asian populations, or South Asian patients are not presenting for treatment. Further work must be performed to determine whether this is an effect of low prevalence, or unmet need in the community.

The glutamine 27 beta2-adrenoceptor polymorphism is associated with elevated IgE levels in asthmatic families

BACKGROUND

The beta2-adrenoceptor polymorphisms occurring at amino acid positions 16 (arginine to glycine) and 27 (glutamine to glutamate) are known to be functionally relevant and also disease-modifying in subjects with asthma. However, the contribution of these polymorphisms to the development of the asthmatic phenotype or other markers for allergic disease remains to be established.

OBJECTIVE

This large family study examines the contributions of these polymorphisms in determining the heritable component of markers for allergic disease in asthmatic families.

METHODS

Three hundred twenty-four individuals from 60 families multiplex for asthma selected by means of an asthmatic proband were characterized for the following markers of allergic disease: asthma, atopy, and serum IgE. The polymerase chain reaction was used to generate a 234 base pair fragment spanning the region of interest, and the beta2-adrenoceptor polymorphism was then defined by allele-specific oligonucleotide hybridization. Segregation analysis was then performed.

RESULTS

We found a significant association (p = 0.009) between the glutamine 27 beta2-adrenoceptor polymorphism and elevated levels of IgE, which was supported by the observation of linkage between IgE and beta2-adrenoceptor polymorphisms at locus 27 (p = 0.037). However, there was no association between either the arginine-glycine 16 or the glutamine-glutamate 27 beta2-adrenoceptor polymorphism and an increased risk of asthma or atopy per se.

CONCLUSION

The glutamine 27 beta2-adrenoceptor polymorphism appears to contribute to IgE variability in families with asthma. However, it seems that although both amino acid 16 and 27 beta2-adrenoceptor polymorphisms are disease-modifying in subjects with asthma, they do not contribute markedly to the development of the asthmatic phenotype.

Diclofenac vs oxybuprocaine eyedrops for analgesia in paediatric strabismus surgery

Forty children undergoing strabismus surgery as day patients were randomly allocated to receive oxybuprocaine 0.4% eyedrops or 0.1% diclofenac eyedrops for perioperative analgesia. A non-invasive anaesthetic technique using the reinforced laryngeal mask airway was used. The study demonstrated that both topical analgesics provided good to excellent analgesia and the anaesthetic technique was associated with a relatively low incidence of nausea and vomiting. Complications were limited to two children who were admitted with persistent postoperative nausea and vomiting.

APC intragenic haplotypes in familial adenomatous polyposis

Genetic epidemiological studies are useful for the knowledge of the association of markers and genes involved in diseases. In the present work, we studied the frequency of four adenomatous polyposis coli intragenic RFLP markers often used in risk evaluation in a population of 10 familial adenomatous polyposis patients from 10 unrelated Portuguese familial adenomatous polyposis families not sharing the same mutation, and in a population of 55 unrelated healthy Portuguese volunteers. We compared the frequency obtained to normal and affected populations and to results already reported in other populations. We observed allelic frequencies for the Portuguese population that agree with the published ones. The intragenic polymorphisms show strong gametic disequilibrium suggesting little recombination between them. We observed haplotype frequencies significantly different in patients and controls. The gametic disequilibrium may be due to a common founder for a proportion of apparently unrelated probands.

Episodic memory dysfunction during sodium amytal testing of epileptic patients in relation to posterior cerebral artery perfusion

The effect of filling of the posterior cerebral artery (PCA) on memory performance during the intracarotid sodium amytal test (IAP) was investigated in 57 patients with unilateral temporal epileptic seizure foci under consideration for surgical therapy. Memory functioning was tested following injection of the internal carotid artery contralateral and ipsilateral to the side of seizure focus. In both cases, patients with PCA filling observed using conventional angiography showed a greater memory deficit, although this effect was more robust with contralateral injections. In a subsample of patients with left hemisphere dominance for language, the effect of PCA filling on memory performance was only significant when the right hemisphere was injected. The implications of these findings are discussed in terms of the validity of the IAP test and the different factors that need to be taken into account when interpreting IAP memory performance.

A role for FGF-8 in the initiation and maintenance of vertebrate limb bud outgrowth

BACKGROUND

The outgrowth of the vertebrate limb bud is the result of a reciprocal interaction between the mesenchyme and a specialized region of the ectoderm, the apical ectodermal ridge (AER), which overlies it. Signals emanating from the AER act to maintain the underlying mesenchyme, called the progress zone, in a highly proliferative and undifferentiated state. Removal of the AER results in the cessation of limb bud growth, thus causing limb truncation. The best candidates for this AER-derived signal are members of the fibroblast growth factor (FGF) family, in particular FGF-4, which can maintain limb bud outgrowth following removal of the AER. However, FGF-4 is only expressed after considerable outgrowth has occurred and a well-developed limb bud has formed, and then only in the posterior part of the AER. Likewise, the other FGFs studied to date are not candidates for this activity.

RESULTS

We report evidence that a recently identified member of this family, FGF-8, is expressed in the ectoderm of the prospective limb territory prior to morphological outgrowth of the limb bud in both mouse and chick. Thereafter, expression is maintained throughout the AER during limb development. We have produced and purified the FGF-8 protein, and shown that it will substitute for the AER in maintaining limb bud outgrowth in mouse embryos from which the AER has been surgically removed. FGF-8 does not, however, maintain expression of the sonic hedgehog gene.

CONCLUSIONS

These results indicate that FGF-8 is an AER-derived mitogen that stimulates limb bud outgrowth. Moreover, our data suggest that FGF-8 may also be an ectodermally derived mitogen that stimulates the onset of limb bud outgrowth (budding) in the absence of a morphological AER, and indicate the possible involvement of FGF-8 in the establishment of the limb field.

Positive association in the absence of linkage suggests a minor role for the glucokinase gene in the pathogenesis of type 2 (non-insulin-dependent) diabetes mellitus amongst south Indians

Mutations of the glucokinase gene have been implicated in the development of glucose intolerance in pedigrees with maturity-onset diabetes of the young. However, the contribution of the glucokinase gene to the aetiology of common Type 2 (non-insulin-dependent) diabetes mellitus is uncertain. We have studied the role of the glucokinase gene in the pathogenesis of Type 2 diabetes in South Indians, using both population-association and linkage methodology. A pair of CA-repeat sequences (GCK(3') and GCK(5')) straddling the glucokinase gene were employed as markers, each subject being typed using the polymerase chain reaction and polyacrylamide gel electrophoresis. Comparisons of allele frequencies at these markers were made between 168 Type 2 diabetic subjects and 70 racially-matched control subjects. No differences in allele frequencies were apparent at the GCK(5') marker; however, there were significant differences in allele frequencies at the GCK(3') marker between the Type 2 diabetic subjects and control subjects (chi 2 = 11.6, df = 3, p = 0.009) with an increase of the z allele (78.0% vs 66.4%) and a decrease of the z + 2 allele (13.7% vs 25.0%) amongst the diabetic subjects. Linkage between glucose intolerance and the glucokinase gene was studied in 53 nuclear pedigrees under a variety of genetic models. Linkage was excluded (lod score < -2) at a recombination fraction of zero under five of the ten models used and highly unlikely (-2 < lod score < -1) under the others. The combination of positive association and negative linkage suggests that glucokinase acts as a minor gene influencing the development of Type 2 diabetes within this population.

Despite intensive efforts, egg-related salmonellosis outbreaks continue

Reports of gastrointestinal disease, traced to bacterial contamination of foods, have recently increased in number and scope. Escherichia coli, a variety of Salmonella species and other bacterial pathogens have been isolated in many diagnoses in various parts of the country. Food trace-backs have implicated a variety of uncooked, cooked and under-cooked food sources, including cantaloupes, apple cider, ground beef, cow's milk, poultry products and even fresh, shell-in-tact table eggs. This report is intended to update the reader on control measures currently implemented for the production, processing and distribution of table eggs, specifically to control Salmonella enteritidis.

Transmission of breast cancer--a controversy resolved

The Danish breast cancer data collected by Jacobsen (1946) have been reanalysed using morbid risks which incorporate mortality due to breast cancer. A dominant gene is favoured for familial breast cancer, supporting the conclusions of Williams & Anderson (1984) and later authors. Neglect of specific mortality does not greatly alter estimates of gene frequency and displacement, but the evidence for a major gene is inflated. No evidence for heterogeneity was found. Earlier claims of non-Mendelian transmission are in error since we have discovered that transmission probabilities are not correctly implemented in the computer program POINTER. Cases with bilateral breast cancer and males with breast cancer all belonged to families favouring a major gene. Of the cancer sites frequently reported to be associated with familial breast cancer, only ovarian cancer is significant in this material.

Von Hippel-Lindau disease: a genetic study

Genetic aspects of von Hippel-Lindau (VHL) disease were studied in familial and isolated cases. Complex segregation analysis with pointers was performed in 38 kindreds with two or more affected members. Dominant inheritance with almost complete penetrance in the highest age classes (0.96 at 51 to 60 and 0.99 at 61 to 70 years) was confirmed and there was no evidence of heterogeneity between families ascertained through complete and incomplete selection. The point prevalence of heterozygotes in East Anglia was 1.89/100,000 (1/53,000) persons with an estimated birth incidence of 2.73/100,000 (1/36,000) live births. Reproductive fitness was 0.83. Direct and indirect estimates of the mutation rate were 4.4 (95% CI 0.9 to 7.9) x 10(-6)/gene/generation and 2.32 x 10(-6)/gene/generation respectively. There was no significant association between parental age or birth order and new mutations for VHL disease.

Pharmacokinetic model driven infusion of propofol in children

A computer controlled infusion device for propofol was used to induce and maintain general anaesthesia in 20 children undergoing minor surgical procedures. The device was programmed with an adult pharmacokinetic model for propofol. During and after anaesthesia, blood samples were taken for measurement of propofol concentrations and it was found that the values obtained were systematically overpredicted by the delivery system algorithm. New pharmacokinetic microconstants were derived from our data which reflected more accurately the elimination and distribution of propofol in a prospective study involving another 10 children.

Leukaemia and transient leukaemia in Down syndrome

We have reviewed 215 published cases of leukaemia and transient leukaemia in Down syndrome. There is an over-representation of mosaic trisomy 21, possibly the result, at least in part, of a survival effect. The most intriguing observation is a bimodal distribution of maternal age, produced largely because cases with true leukaemia have a significantly higher maternal age than cases with transient leukaemia (33.5 versus 29.5 years). In conjunction with evidence that meiosis I nondisjunction is infrequent in transient leukaemia, this suggests different mechanisms for the etiology of leukaemia and transient leukaemia, and favours a locus predisposing to transient leukaemia proximal to the centromere on the long arm of chromosome 21.

Mode of processing and hemisphere differences in the judgement of musical stimuli

The relationship between processing strategy and ear asymmetry was examined in two experiments in which subjects were required to make judgements about monoaurally presented musical chords. In the first experiment, subjects without musical training showed a significant left ear advantage while in those with musical training a significant shift towards a right ear advantage was observed. Performance on the Embedded Figures Test (EFT) suggested a strong relationship between analytic processing style and right ear advantage which was significant in the musician groups. The effect of musical training status on ear asymmetry continued to be significant when the scores were adjusted for analytic processing. There was also a clear relationship between self-reported listening strategies and direction of ear asymmetry, with musicians generally reporting a much greater use of analytic strategies. The second experiment failed to demonstrate a significant influence of explicit instructions in how to carry out a chords task on the direction of ear advantages in musically untrained subjects. The results partially confirm earlier studies comparing subjects with and without musical training, and extend them by demonstrating a clear relationship between ear advantage and a separate measure of processing strategy. The findings of the second experiment, however, do not support clearly the hypothesis that differences in ear asymmetry are produced through the use of different processing strategies.

Rebound hypertension after discontinuation of transdermal clonidine therapy

Three (and possibly all four) elderly hypertensive patients who were followed sequentially after discontinuation of transdermal clonidine monotherapy manifested a rapid rise in blood pressure to levels above control (pre- and post-therapy) readings. No signs of an "overshoot" in plasma norepinephrine levels or symptoms of beta-adrenergic overactivity were seen. Such rebound hypertension suggests hypersensitivity to alpha-adrenergic receptor stimulation and could pose a heretofore unreported potential hazard to elderly or otherwise compromised patients who discontinue transdermal clonidine therapy.

Recovery of blood and bone marrow stem cells following intense chemotherapy and autologous bone marrow transplantation

Sixteen patients with advanced (stage III) malignant melanoma were treated with escalating doses of intravenous BCNU and melphalan starting at 400 and 35 mg/m2, respectively, and escalating to 1,000 and 110 mg/m2, respectively, combined with autologous marrow transplantation. The duration of granulocytopenia and time to granulocyte recovery was similar in all groups regardless of chemotherapy dose. Platelet recovery was delayed in patients receiving the highest doses of chemotherapy. This study showed that bone marrow colony-forming units in culture took as long as 6 months to recover. This was adequate to bring peripheral blood counts to normal but not to pretreatment levels. These studies indicate that autologous bone marrow transplantation is beneficial in enhancing short-term recovery, but may not be beneficial in the long-term hematopoietic recovery.

Transdermal clonidine therapy in elderly mild hypertensives: effects on blood pressure, plasma norepinephrine and fasting plasma glucose

Twenty patients aged 60-74 years entered a study on the effect of transdermal clonidine (Catapres-TTS) as monotherapy for mild hypertension [diastolic blood pressure (DBP) 90-104 mmHg]. Seventeen patients (85%) had a positive therapeutic response (DBP reduced to less than 90 mmHg or by greater than or equal to 5 mmHg). Patient acceptance was high and side effects mild; however, one-quarter of the patients experienced localized skin reactions. A slight increase in fasting plasma glucose level (mean delta = 20 mg/dl) was consistently observed. Transdermal clonidine led to a sustained decline in plasma catecholamine levels although this effect did not seem to be closely related to the observed decreases in blood pressure. Three out of four evaluable patients had a blood pressure 'overshoot' upon discontinuation of therapy to levels above pretreatment values. Transdermal clonidine appears to be effective and generally well tolerated in the treatment of mild hypertension in the elderly; however, more studies designed to investigate effects on glucose tolerance and the possible existence of a rebound syndrome are needed.

Treatment of advanced malignant melanoma with high-dose chemotherapy and autologous bone marrow transplantation. Preliminary results--Phase I study

Thirteen patients with advanced (Stage III) malignant melanoma have been treated with high-dose chemotherapy (nitrogen mustard or a combination of BCNU and melphalan) combined with autologous, nonfrozen, bone marrow transplantation. Three patients (24%) achieved a complete remission and are currently alive and free of disease without further therapy at 26, 60, and 73 weeks. Five patients (38%) achieved partial remissions and five patients (38%) had no response. There was no difference in the response rate to nitrogen mustard and the BCNU-melphalan combination. Severe side effects to nitrogen mustard, however, precluded its further use in this study. The major cause of death in patients was intracerebral metastases, raising the question of prophylactic brain irradiation in future studies. Studies of the recovery rate of peripheral blood neutrophil, platelet, and peripheral blood and bone marrow CFU-C suggest that autologous bone marrow infusion may be of benefit in shortening hematopoietic recovery following intensive chemotherapy.

Autologous bone marrow transplantation in the therapy of small cell carcinoma of the lung

Ten patients with small cell carcinoma of the lung were entered into a chemotherapeutic treatment program consisting of cyclophosphamide, vincristine, Adriamycin, and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea. Two courses of combination chemotherapy were administered to each patient followed by a third course with the same doses of drugs used on Course 2 but with autologous bone marrow transplantation given 24 to 48 hr after drug infusion. No differences could be detected between Courses 2 and 3 in terms of the magnitude, timing, or degree of myelosuppression. Serial bone marrow biopsies documented a progressive decline in granulocyte-macrophage colony-forming units in culture per mg bone marrow medullary core from 138 +/- 179 (S.D.) prior to chemotherapy to 7 +/- 11 after the marrow transplant recovery (p = 0.05). These data suggest that autologous bone marrow transplantation does not reduce the myelosuppression seen following the drugs used in this study at the dosages used. Autologous bone marrow transplantation may be useful only in the setting of marrow lethal therapy. Its usefulness in shortening recovery time from nonlethal therapy appears questionable.

[Bacterial infection and the regulation of in vivo granulopoiesis]

The mechanism which regulates granulopoiesis was investigated in C 57 BL mice injected i.p. with E.coli. The positive and negative feedback arm of the regulation was studied by correlating the number of bacteria, the number of granulocytes, serum CSF levels and the number of CFU-C in the bone marrow.