Expression and polarized targeting of a rab3 isoform in epithelial cells.

Pathways of polarized membrane traffic in epithelial tissues serve a variety of functions, including the generation of epithelial polarity and the regulation of vectorial transport. We have identified a candidate regulator of polarized membrane traffic in epithelial cells (i.e., rab3B), which is a member of the rab family of membrane traffic regulators. Rab3B is highly homologous to a brain-specific rab3 isoform (rab3A) that targets in a polarized fashion to the presynaptic nerve terminal, where it probably regulates exocytosis. The coding region for human rab3B was cloned from epithelial mRNA using a reverse-transcription polymerase chain reaction strategy. This cDNA clone hybridized to a single mRNA species in Northern blots of poly(A)+ RNA isolated from epithelial cell lines. A rab3B-specific antibody that was raised against recombinant fusion protein recognized a 25-kD band in immunoblots of cell lysates prepared from cultured epithelial cells (e.g., T84 and HT29-CL19A), but not from a variety of nonepithelial cells (e.g., PC12 neuroendocrine cells). Immunofluorescence analysis confirmed that rab3B protein is preferentially expressed in cultured epithelial cells as well as in a number of native epithelial tissues, including liver, small intestine, colon, and distal nephron. Rab3B localized to the apical pole very near the tight junctions between adjacent epithelial cells within all of these cell lines and native epithelial tissues, as determined by immunofluorescence and immunoelectron microscopic analysis. Moreover, this pattern of intracellular targeting was regulated by cell contact; namely, rab3B was reversibly retrieved from the cell periphery as epithelial cell contact was inhibited by reducing the extracellular Ca2+ concentration. Our results indicate that neurons and epithelial cells express homologous rab3 isoforms that target in a polarized fashion within their respective tissues. The pattern and regulation of rab3B targeting in epithelial cells implicates this monomeric GTPase as a candidate regulator of apical and/or junctional protein traffic in epithelial tissues.

Nasal fracture reduction: local versus general anaesthesia.

OBJECTIVE: To investigate the outcomes from nasal fracture reduction performed under local anaesthesia (LA) and general anaesthesia (GA). METHOD: A randomised multi-centred prospective trial and cohort analysis. Patients were randomised into two groups, 74 (53%) underwent closed reduction under LA, 65 (47%) patients underwent closed reduction under GA. MAIN OUTCOME MEASURES: Pain scores and patient toleration of local or general nasal manipulation was noted. RESULTS: The pain score ranged from 0 (no pain) to 10 (unbearable pain). The mean pain score in the LA group was 3, compared to 2 in the GA group. LA manipulation was tolerated equally well as GA manipulation by 85% of the patients in each group. The number of patients requiring a septorhinoplasty was compared between LA 19/74 (26%), and GA 21/65 (32%). This failed to demonstrate a significant difference with a p value of 0.50. The absolute risk difference was 5% with a 95% confidence interval of (20% to -10%). CONCLUSION: This trial clearly shows LA to be as effective as GA in the first line management of nasal fractures. The degree of septal displacement and presence of nasal tip deviation were associated with persistent nasal deformity following nasal fracture reduction.

Predictors of audiological outcome following cochlear implantation in adults.

The objective of this study was to examine variables that may predict open set speech discrimination following cochlear implantation. It consisted of a retrospective case review conducted in a tertiary referral centre with a cochlear implant programme. The patients were 117 postlingually deafened adult cochlear implant recipients. The main outcome measures were Bench, Kowal, Bamford (BKB) sentence scores recorded nine months following implant activation. The variables studied were age at the time of surgery, sex, duration of hearing loss, aetiology of hearing loss, residual hearing, implant type, speech processor strategy, number of active electrodes inserted. Variables found to have a significant effect on BKB following univariate analysis were entered into a multivariate analysis to determine independent predictors. Multivariate ordinal regression analysis gave an odds ration of 1.09 for each additional year of deafness prior to implantation (confidence interval 1.06-1.13; p < 0.001). Duration of deafness prior to implantation is an independent predictor of implant outcome. It accounted for 9% of the variability. Other factors must influence implant performance.

Making human nasal cilia beat in the cold: a real time assay for cell signalling.

Human nasal epithelium must adapt to cold climates, and yet, in vitro, human ciliary beat frequency (CBF) is zero at 4 degrees C. Similarly, hibernating mammals do not die of pneumonia despite a core body temperature as low as 6 degrees C, implying that cilia continue to beat. Here, we show that protein kinase C (PKC) and Ca(2+)/calmodulin-dependent kinase II (CaMKII) regulate the profile of human nasal CBF in response to rising temperature from 4 degrees C. Onset of ciliary beat was at 10 degrees C in Medium 199, 7 degrees C in the presence of the PKC activator phorbol 12-myristate 13-acetate (PMA), the calcium ionophore ionomycin, or the CAMKII blocker myristoylated autocamtide-2 related inhibitory peptide (MACI), and 6 degrees C for the myristoylated peptide PKC inhibitor EGF-R Fragment 651-658 (MyrPKCI). During cell warming to 32 degrees C, the thermal profile was sigmoid in all solutions except those containing MACI+PMA. Surprisingly, cilia continued to beat despite 4 degrees C and were significantly more responsive to rising temperature with either MACI+PMA, or MACI+MyrPKCI. Our data suggest that CaMKII and PKC regulate the thermal slope and profile of CBF in vitro, and that when these protein kinases are manipulated, cilia can continue to beat despite hypothermia. These findings may relate to adaptive responses to cold climates.

The effects of food deprivation and incentive motivation on blood glucose levels and cognitive function.

The current study investigated the relationships between blood glucose levels, mild food deprivation, sympathetic arousal, and cognitive processing efficiency. Subjects (n = 82) were randomly assigned to four experimental conditions, comprising combined manipulations of food deprivation and incentive motivation. Baseline and mid-session measurements of blood glucose, blood pressure and pulse rate were taken. Subjects completed a number of measures of cognitive processing efficiency and self report measures of affective and somatic state. Although glucose levels were lowered following food deprivation, there was no significant detrimental effect of food deprivation on task performance. However, improved recognition memory processing times were associated with deprivation. Incentive motivation was associated with faster simple reaction times and higher diastolic blood pressure. There were no significant relationships between glucose levels and task performance, further supporting the hypothesis that the brain is relatively invulnerable to short food deprivation.

Effect of radiotherapy on oral mucosa assessed by quantitative exfoliative cytology.

The effect of radiotherapy on normal buccal mucosa was investigated using the quantitative techniques of cytomorphology (measurement of nuclear and cytoplasmic area) and DNA cytophotometry. These techniques were applied to smears obtained before, during, and after irradiation. Nuclear area and cytoplasmic area increased and DNA values were abnormal in most cases as a result of radiotherapy, returning to within normal limits one month after treatment. This contrasts strongly with the changes seen in smears from previously irradiated uterine cervices, where changes in cytomorphology may persist for several years.

Cognitive functioning, weight change and therapy in anorexia nervosa.

Anorexia nervosa is associated with impairments in cognitive function which have been hypothesized to be fundamentally attentional in nature. The current study investigated whether therapy and weight gain affect these impairments. A group of anorexics (N = 12) completed a battery of cognitive performance tasks and self-report measures of psychopathology on three occasions, over the course of 12 weeks of in-patient treatment. A non-clinical control population (N = 17) completed the same measures. The anorexics improved on all measures of psychopathology and affective state as a result of therapy. Anorexics displayed poorer recall, reaction times, and motor speed than the control subjects. Although there was a gain in weight over the course of therapy, there was no corresponding improvement in cognitive performance. Impaired task performance in anorexics was not directly related to their psychopathology or affective state.

Lack of effect of short-term fasting on cognitive function.

In a study designed to assess the effects of short-term food deprivation on cognitive function, a sample of female subjects (N = 21) was tested on a number of measures of cognitive function after three levels of food deprivation (miss one meal, miss two meals or miss all food for 24 h prior to testing) and a condition in which they ate normally for 24 h prior to testing. There was found to be no significant effects of food deprivation on sustained attention, attentional focus, simple reaction time or immediate memory. However, performance on a low processing load tapping task was significantly poorer when the subjects were deprived of food for 24 h prior to testing, and heart rate was significantly higher when they were non-deprived. These results stand in contrast to the impairments in cognitive function previously found to be associated with spontaneous dieting behaviour (using essentially the same task battery).

A spectrum of exertional headaches.

Headaches that have an explosive onset with exercise, including sexual activity, generally are benign in origin. A subarachnoid hemorrhage, a mass lesion in the brain, or an anomaly of the posterior fossa must be considered, however. The mechanisms that produce sexually induced or cough headaches of abrupt onset are unknown. It is known, however, that a rapid increase in intrathoracic pressure suddenly reduces right atrial pressure and presumably decreases venous sinus drainage from the brain. This situation results in a transient increase in intracranial pressure. Jaw pain that occurs with chewing often is considered to be TMJ dysfunction when arthritic in quality and if subluxations of the jaw can be shown on the physical examination. Giant cell arteritis and common or external carotid artery occlusive disease should be considered when the pain is ischemic in quality. An anginal equivalent is another possibility. Headaches that worsen with vigorous exercise are commonly migrainous. When their onset is apoplectic with exertion (particularly exertion against a closed glottis), the most likely diagnoses are increased intracranial pressure, a posterior fossa abnormality, or benign exertional headaches. Most cardiac induced headaches, but not all, are of a more gradual onset. If there are significant risk factors for coronary artery disease, an exercise stress test is appropriate. A therapeutic trial of nitroglycerin may help to establish a diagnosis if it improves the headache. Using antimigraine drugs as a diagnostic test is inappropriate because triptans and ergots are contraindicated in the presence of coronary artery disease, and a positive response is not diagnostic of migraine.

Mood and cognitive performance effects of isocaloric lunches differing in fat and carbohydrate content.

Eighteen subjects consumed low-fat/high-carbohydrate (LFHC) (29% fat, 54% carbohydrate, 15% protein), medium-fat/medium-carbohydrate (MFMC) (45% fat, 42% carbohydrate, 12% protein), and high-fat/low-carbohydrate (HFLC) (62% fat, 24% carbohydrate, 13% protein) isocaloric lunches in random order on 3 separate days. The MFMC lunch was similar in energy and macronutrient composition to the habitual lunchtime intake of the subjects. A battery of cognitive performance tasks together with mood and appetite ratings were carried out before and during the 3 h after lunch. Results showed longer reaction times following the LFHC and HFLC lunches compared to the MFMC lunch, which produced an improvement in performance on this task. In addition, subjects rated themselves as more drowsy, uncertain and muddled, and less cheerful after the LFHC and HFLC lunches compared to the MFMC lunch, and as less tense after the LFHC meal. These findings indicate that the macronutrient content of lunch can have significant acute effects on subsequent mood and performance. In particular, higher than usual proportions of fat or carbohydrate produced a relative impairment of cognitive efficiency.

Impairment of cognitive performance associated with dieting and high levels of dietary restraint.

Seventy women students were tested on a short battery of tasks assessing cognitive performance. They also completed self-report ratings of mood, the Dutch Eating Behaviour Questionnaire (DEBQ) to which was appended several additional items concerning their recent dieting behaviour, and a 24-h dietary recall. Heart rate was measured before and after testing. Compared with nondieting subjects with low to moderate scores on the restraint factor of the DEBQ, subjects (n = 15) who reported that they were currently dieting to lose weight displayed impaired performance on a vigilance task and also tended to show poorer immediate memory and longer reaction times. Highly restrained eaters who were not dieting at the time of testing, on the whole, performed at an intermediate level on these tests. In contrast, the dieters tended to show the best performance on an undemanding finger tapping task, indicating that they were not slowed in their fine motor responses or lacking in motivation to carry out the tasks. Poorer cognitive functioning during dieting could arise as a direct consequence of the effects of food restriction on energy metabolism or other physiological mechanisms--the dietary records indicated that the current dieters were eating at about 70% of maintenance energy requirement. However, it is also possible that cognitive performance is impaired during dieting due to anxiety resulting from stressful effects of imposing and maintaining dietary restraint.

Behavioral and body size correlates of energy intake underreporting by obese and normal-weight women.

OBJECTIVE: To examine behavioral and body size influences on the underreporting of energy intake by obese and normal-weight women. DESIGN: Seven-day estimated food records were kept by subjects before they participated in a 49-day residential study. Self-reported energy intake was compared with energy intake required to maintain a stable body weight during the residential study (reference standard). Energy intake bias and its relationship to various body size and behavioral measures were examined. SUBJECTS: Twenty-two, healthy, normal-weight (mean body mass index [BMI] = 21.3) and obese (mean BMI = 34.2) women aged 22 to 42 years were studied. STATISTICAL ANALYSES: Analysis of variance, paired t test, simple linear regression, and Pearson correlation analyses were conducted. RESULTS: Mean energy intake from self-reported food records was underreported by normal-weight (-9.7%) and obese (-19.4%) women. BMI correlated inversely with the energy intake difference for normal-weight women (r = -.67, P = .02), whereas the Beck Depression Inventory correlated positively with the energy intake difference for obese women (r = .73, P < .01). CONCLUSION/APPLICATIONS: Results suggest that body size and behavioral traits play a role in the ability of women to accurately self-report energy intake. BMI appears to be predictive of underreporting of energy intake by normal-weight women, whereas emotional factors related to depression appear to be more determinant of underreporting for obese women. Understanding causative factors of the underreporting phenomenon will help practicing dietitians to devise appropriate and realistic diet intervention plans that clients can follow to achieve meaningful change.

Cognitive function, iron status, and hemoglobin concentration in obese dieting women.

OBJECTIVE: To determine the relationships between cognitive function and iron status in dieting obese women. DESIGN: Longitudinal weight loss study (repeated measures within-subject design) with 3 weeks of baseline, 15 weeks of 50% caloric restriction, and 3 weeks of weight stabilization. Dietary iron was fed at twice the US Recommended Dietary Allowance with half of the iron from food sources and half from an oral supplement. SETTING: This was a free-living study with the exception that subjects came to the research center for one meal per day and were provided all other meals and snacks to take home. SUBJECTS: Healthy, premenopausal, obese women (mean BMI=31.5) were recruited through local newspaper, poster and radio advertising. Twenty-four women volunteers were recruited and 14 completed the study. MEASUREMENTS: Cognitive function, iron and hematological status, height, body weights and body composition were measured at baseline; at weeks 5, 10, and 15 of the energy restriction period; and at the end of weight stabilization. Computerized cognitive tests included: Bakan vigilance task, two finger tapping, simple reaction time, immediate word recall, and a focused attention task. Iron status and hematological measures included: serum iron, total iron binding capacity (TIBC), transferrin saturation, serum ferritin, hemoglobin (Hb), hematocrit, red cell count, MCV, MCH, MCHC, and RDW. RESULTS: A significant reduction in Hb, hematocrit, and red blood cell count occurred across the study. Hb at the end of the study was positively correlated (r=0.72, P < 0.01) with mean performance on a measure of sustained attention. Transferrin saturation also correlated positively to sustained attention task performance for those subjects whose Hb declined across the study (r=0.86, P < 0.01). CONCLUSIONS: These findings suggest that dieting diminishes iron status in obese women, even when sufficient dietary iron is available, and that the inability to sustain attention may be an early sign of developing iron deficiency in dieting women.

Dieting, dietary restraint and cognitive performance.

In a volunteer sample of female undergraduates, concerns about eating, body weight and body shape were found to increase with the level of self-reported dietary restraint. These concerns were greatest, however, in a subsample of subjects who were currently dieting to lose weight, and greater than in equally restrained but non-dieting subjects. Furthermore, the dieting subjects performed less well on a demanding cognitive task than the non-dieting subjects. These results show that it is important to distinguish between dietary restraint and actual dieting behaviour. They also highlight the need for further research to examine the effects of dieting on cognitive functioning.

Hunger, caloric preloading and the selective processing of food and body shape words.

Fifty-three female subjects performed a modified Stroop colour-naming task 30 minutes after consuming a high-calorie preload, a low-calorie preload or water. Half of the subjects were 18 hours food deprived prior to testing. Food restriction and the caloric density of the preload had no effect on the colour-naming of food-related words. However, impairments in the colour-naming of food-related words did vary according to the subjects' self-reported hunger level. This relationship between hunger and colour-naming impairment was not linear, with the most hungry subjects displaying the smallest impairment in the colour naming of food words. The results are interpreted in terms of recent thought on the relationship between attentional processing and fear arousal.

Habituation patterns to colour naming of eating-related stimuli in anorexics and non-clinical controls.

The current study was an investigation into intra-session changes in the pattern of Stroop colour-naming impairments with body shape-related words and food-related words. The subject pool comprised anorexic women and a control group of non-clinically disordered women. The results indicated that anorexic women show greater colour-naming decrements that non-disordered controls for both types of eating-related words. Stroop interference significantly decreased across the course of the experiment with the body-shape words for the anorexic subjects, thereby indicating habituation to the semantic content of those words. There was no comparable process of habituation observed with the food-related words.

Quantitative exfoliative cytology of abnormal oral mucosal smears.

In this study quantitative techniques have been applied to smears collected from the buccal mucosa and floor of the mouth. The results display an encouraging success rate for identifying premalignant and malignant lesions. 'Intrapatient' normal smears provide a satisfactory control for comparison with pathological smears. Early results indicate that quantitative cytology could be of great value for monitoring and follow-up of suspicious lesions and provide an excellent additional diagnostic test for detecting early oral malignancy.

Quantitative exfoliative cytology of normal oral squames: an age, site and sex-related survey.

This study describes the development of quantitative cytological techniques and their application to oral smears. Nuclear and cell size has been measured and matched with age, sex and site in an attempt to produce a baseline for comparison with identical measurements carried out on pathological smears. The results displayed a significant variation in nuclear and cytoplasmic area between different sites. Nuclear size varied significantly with advancing age; however, this was not the case for cytoplasmic area. There was no significant variation in either criterion between males and females.

Evidence of field change in oral cancer.

Evidence of field change in oral cancer was assessed using quantitative cytomorphometric analysis of smears taken from normal buccal mucosa in oral cancer and cancer-free patients. The nuclear areas (NA) and cytoplasmic areas (CA) were calculated using a semi-automatic image analysis system. A statistically significant reduction in CA (p = 0.002) but no change in NA was observed for the oral cancer group. This change occurred irrespective of tobacco and alcohol usage. We believe this to be the first evidence for true field change since Slaughter's original hypothesis in 1946.

Cluster headaches. How to recognize and treat them.

Cluster headaches must be distinguished from migraine, trigeminal neuralgia, and sinusitis, since these conditions require different therapy. Cluster headaches are so unique, however, that the history alone should be adequate for diagnosis. Prophylactic use of medication is the best approach to management, although determination of the best regimen may take time and require patience of both physician and patient.