Sex differences in a mouse model of diet-induced obesity: the role of the gut microbiome

BACKGROUND

Recent decades have seen an exponential rise in global obesity prevalence, with rates nearly doubling in a span of 40 years. A comprehensive knowledge base regarding the systemic effects of obesity is required to create new preventative and therapeutic agents effective at combating the current obesity epidemic. Previous studies of diet-induced obesity utilizing mouse models have demonstrated a difference in bodyweight gain by sex. In such studies, female mice gained significantly less weight than male mice when given the same high fat (HF) diet, indicating a resistance to diet-induced obesity. Research has also shown sex differences in gut microbiome composition between males and females, indicated to be in part a result of sex hormones. Understanding metabolic differences between sexes could assist in the development of new measures for obesity prevention and treatment. This study aimed to characterize sex differences in weight gain, plasma lipid profiles, fecal microbiota composition, and fecal short chain fatty acid levels. We hypothesized a role for the gut microbiome in these sex differences that would be normalized following microbiome depletion.

METHODS

A mouse model was used to study these effects. Mice were divided into treatment groups by sex, diet, and presence/absence of an antibiotic cocktail to deplete genera in the gut microbiome. We hypothesized that sex differences would be present both in bodyweight gain and systemic measures of obesity, including hormone and circulating free fatty acid levels.

RESULTS

We determined statistically significant differences for sex and/or treatment for the outcome measures. We confirm previous findings in which male mice gained significantly more weight than female mice fed the same high fat diet. However, sex differences persisted following antibiotic administration for microbiome depletion.

CONCLUSIONS

We conclude that sex differences in the gut microbiome may contribute to sex differences in obesity, but they do not explain all of the differences.

Sex differences in a mouse model of diet-induced obesity: the role of the gut microbiome

Background

Recent decades have seen an exponential rise in global obesity prevalence, with rates nearly doubling in a span of forty years. A comprehensive knowledge base regarding the systemic effects of obesity is required to create new preventative and therapeutic agents effective at combating the current obesity epidemic. Previous studies of diet-induced obesity utilizing mouse models have demonstrated a difference in bodyweight gain by sex. In such studies, female mice gained significantly less weight than male mice when given the same high fat (HF) diet, indicating a resistance to diet-induced obesity. Research has also shown sex differences in gut microbiome composition between males and females, indicated to be in part a result of sex hormones. Understanding metabolic differences between sexes could assist in the development of new measures for obesity prevention and treatment. This study aimed to characterize sex differences in weight gain, plasma lipid profiles, fecal microbiota composition, and fecal short chain fatty acid levels. We hypothesized a role for the gut microbiome in these sex differences that would be normalized following microbiome depletion.

Methods

A mouse model was used to study these effects. Mice were divided into treatment groups by sex, diet, and presence/absence of an antibiotic cocktail to deplete genera in the gut microbiome. We hypothesized that sex differences would be present both in bodyweight gain and systemic measures of obesity, including hormone and circulating free fatty acid levels.

Results

We determined statistically significant differences for sex and/or treatment for the outcome measures. We confirm previous findings in which male mice gained significantly more weight than female mice fed the same high fat diet. However, sex differences persisted following antibiotic administration for microbiome depletion.

Conclusions

We conclude that sex differences in the gut microbiome may contribute to sex differences in obesity, but they do not explain all of the differences.

Transcriptome analysis of blastoderms exposed to prolonged egg storage and short periods of incubation during egg storage

BACKGROUND

Cool temperature egg storage prior to incubation is a common practice in the broiler industry; however, prolonged egg storage causes increased embryonic mortality and decreased hatchability and growth in surviving chicks. Exposing eggs to short periods of incubation during egg storage (SPIDES) reduces the adverse consequences of prolonged storage. SPIDES increases blastodermal cell viability by reducing apoptosis, though the counteracting mechanisms are unclear. To define the impact of prolonged storage and SPIDES, transcriptome analysis compared gene expression from blastoderms isolated from eggs exposed to the following treatments: control (CR, stored at 17 °C for 4 days), prolonged storage (NSR, stored at 17 °C for 21 days), SPIDES (SR, stored at 17 °C for 21 days with SPIDES), and incubated control (C2, stored at 17 °C for 4 days followed by incubation to HH (Hamburger-Hamilton) stage 2, used as the ideal standard development) (n = 3/group). Data analysis was performed using the CLC Genomics Workbench platform. Functional annotation was performed using DAVID and QIAGEN Ingenuity Pathway Analysis.

RESULTS

In total, 4726 DEGs (differentially expressed genes) were identified across all experimental group comparisons (q < 0.05, FPKM> 20, |fold change| > 1.5). DEGs common across experimental comparisons were involved in cellular homeostasis and cytoskeletal protein binding. The NSR group exhibited activation of ubiquitination, apoptotic, and cell senescence processes. The SR group showed activation of cell viability, division, and metabolic processes. Through comparison analysis, cellular respiration, tRNA charging, cell cycle control, and HMBG1 signaling pathways were significantly impacted by treatment and potential regulatory roles for ribosomal protein L23a (RPL23A) and MYC proto-oncogene, BHLH transcription factor (MYC) were identified.

CONCLUSIONS

Prolonged egg storage (NSR) resulted in enriched cell stress and death pathways; while SPIDES (SR) resulted in enriched basic cell and anti-apoptotic pathways. New insights into DNA repair mechanisms, RNA processing, shifts in metabolism, and chromatin dynamics in relation to egg storage treatment were obtained through this study. Although egg storage protocols have been examined through targeted gene expression approaches, this study provided a global view of the extensive molecular networks affected by prolonged storage and SPIDES and helped to identify potential upstream regulators for future experiments to optimize egg storage parameters.

Incidence of brain metastasis from esophageal cancer

We investigated whether the incidence of brain metastasis (BM) from primary esophageal and esophagogastric cancer is increasing. A single-institution retrospective review identified 583 patients treated from January 1997 to January 2016 for stages I through IV cancer of the esophagus and esophagogastric junction (follow-up, ≥3 months). Collected data included demographic information, date and staging at primary diagnosis, histologic subtype, treatment regimen for primary lesion, date of BM diagnosis, presence or absence of central nervous system symptoms, presence or absence of extracranial disease, treatment regimen for intracranial lesions, and date of death. The overall cohort included 495 patients (85%) with adenocarcinoma and 82 (14%) with squamous cell carcinoma (492 [84%] were male; median age at diagnosis, 68 years [range: 26-90 years]). BM was identified in 22 patients (3.8%) (median latency after primary diagnosis, 11 months). Among patients with BM, the primary histology was adenocarcinoma in 21 and squamous cell carcinoma in 1 (P = 0.30). BM developed in 12 who were initially treated for locally advanced disease and in 10 stage IV patients who presented with distant metastases. Overall survival (OS) after BM diagnosis was 18% at 1 year (median, 4 months). No difference in OS after BM diagnosis was observed in patients initially treated for localized disease compared to patients who presented with stage IV disease; however, OS was superior for patients who initially had surgical resection compared to patients treated with whole brain radiotherapy or stereotactic radiosurgery alone (1-year OS, 67% vs. 0%; median OS, 13.5 vs. 3 months; P = 0.003). The incidence of BM is low in patients with esophageal cancer. Outcomes were poor overall for patients with BM, but patients who underwent neurosurgical resection had improved survival.

Self-Referenced Coherent Diffraction X-Ray Movie of Ångstrom- and Femtosecond-Scale Atomic Motion

Time-resolved femtosecond x-ray diffraction patterns from laser-excited molecular iodine are used to create a movie of intramolecular motion with a temporal and spatial resolution of 30 fs and 0.3 Å. This high fidelity is due to interference between the nonstationary excitation and the stationary initial charge distribution. The initial state is used as the local oscillator for heterodyne amplification of the excited charge distribution to retrieve real-space movies of atomic motion on ångstrom and femtosecond scales. This x-ray interference has not been employed to image internal motion in molecules before. Coherent vibrational motion and dispersion, dissociation, and rotational dephasing are all clearly visible in the data, thereby demonstrating the stunning sensitivity of heterodyne methods.

304 TREATMENT OF BOAR SPERM WITH RESPIRATION INHIBITOR MENADIONE: EFFECTS ON MOTILITY, REACTIVE OXYGEN SPECIES (ROS), MITOCHONDRIAL TRANSMEMBRANE POTENTIAL (MMP), AND ATP CONTENT

Previously we found that live, fresh or thawed boar sperm show little tendency to accumulate ROS spontaneously, but live sperm accumulated ROS during a 30-min incubation with xanthine and xanthine oxidase and showed marked reduction in motility. High mitochondrial transmembrane potential (MMP) is required to drive the F0/F1 ATPase responsible for producing ATP in most cell types, and ATP is required for sperm motility. This experiment was conducted to investigate the effects of menadione (disrupter of electron transport at Complex I) on sperm motility, MMP, and ATP content. The incidence of cells with high MMP was determined by measuring the fluorescence of JC-1 aggregates bound to the inner mitochondrial membrane using flow cytometry. Computer-assisted motion analysis was conducted using the IVOS version 12 (Hamilton Thorne Research, Beverly, MA, USA), and ATP (pmoles/106 sperm) was determined using the luciferin-luciferase assay. Sperm from six boars were individually Percoll washed to eliminate seminal plasma and incubated at 40 � 106/mL with 0, 1, 10, or 30 �M menadione for 5, 30, 60, and 120 min at 38�C in a modified Tyrode's medium containing 0.1% polyvinyl alcohol with no bicarbonate or BSA. The formation of ROS was confirmed by measuring the red fluorescence developed by the oxidation of hydroethidine to ethidium using flow cytometry. Whereas the basal level of ethidium fluorescence in the absence of menadione was low (2% ethidium-positive cells at 5 min), 10 and 30 �M menadione increased (P < 0.05) the percentage of ethidium-positive cells to 47 and 87%, respectively, at 30 min. Sperm motility did not decrease significantly (79-83%) during the 120 min incubation with no menadione, but menadione caused a significant dose-related decrease (P < 0.05) over time, with 10 and 30 �M menadione decreasing motility to 60 and 40%, 51 and 7%, and 10 and 1% at 30, 60, and 120 min, respectively. JC-1 aggregate fluorescence intensity decreased (P < 0.05) by 45-60% in a dose-related fashion at 120 min compared to the same doses at 5 min. Sperm viability, as measured by number of propidium iodide negative cells, averaged 93.6% during the incubation and was not significantly affected by treatment. The effect of menadione on ATP content was much less than that on motility or JC-1 fluorescence intensity. Mean ATP content averaged 63 pmoles through 60 min at all menadione doses; at 120 min only 30 �M menadione decreased (P < 0.05) ATP to 43 pmoles, compared to all other treatments. Menadione caused an increase in ROS formation and a decline in MMP, which suggested uncoupling of the respiratory chain and oxidative phosphorylation. However, sperm ATP content was not highly correlated with motility. This suggests that ATP content was maintained by the activity of other intermediary metabolism pathways. The reduction in motility may have been due to a ROS induced lesion in ATP utilization or in the contractile apparatus of the cell.

Improvements in carotid endarterectomy in Scotland: results of a national prospective survey

BACKGROUND AND AIMS

The effectiveness of carotid endarterectomy (CEA) depends upon selection of patients with a high absolute risk of stroke, avoidance of delays from intial presentation to surgery and provsion of surgery with a low perioperative risk of stroke. We evaluated these aspects of practice in Scottish hospitals and, by encouraging adherence to national (SIGN) guidelines, attempted to improve the effectiveness of CEA.

METHODS

Prospective independent survey of patient selection, pre-operative delays and surgical performance for all CEAs performed in Scottish National Health Service hospitals over two 13 month periods from September 1997 and February 1999 respectively.

RESULTS

Thirteen hospitals performed 485 CEAs in the first period and 392 in the second, equating to an overall annual rate of 79 per million population. During both periods at least 95% of patients reported symptoms of carotid terittory ischaemia, but the proportion with stenoses greater than >70% rose from 89% to 97% (p<0.0001). The delays between referral, surgical consultation and subsequent surgery fell significantly but remained unacceptably long. The proportion seen by the surgeon within two weeks of referral rose from 36% to 43% (p=0.05) and the proportion operated on within one month thereafter rose from 35% to 49% (p<.0001). The perioperative combined major stroke and death rate was 3% in both periods.

CONCLUSION

We demonstrated significant changes in practice, in line with national guidelines, which would be expected to improve the effectiveness of our national programme of CEA. There is further scope for improving performance, particularly in relation to pre-operative delays.

Magnetic resonance-detected subchondral bone marrow and cartilage defect characteristics associated with pain and X-ray-defined knee osteoarthritis

OBJECTIVE

To assess whether the presence of subchondral bone marrow abnormalities (bone marrow edema (BME)) and cartilage defects, determined by magnetic resonance imaging (MRI), would explain the difference between painful osteoarthritis of the knee (OAK) compared with painless OAK or pain without OAK.

METHOD

Four groups of women (30 per group), aged 35-55 years, were recruited from the southeast Michigan Osteoarthritis cohort (group 1: painful OAK; group 2: painless OAK; group 3: knee pain without OAK; and group 4: no OAK or knee pain). OAK was defined by a Kellgren-Lawrence score of 2 or greater, while pain was based on self-report. BME and cartilage defects were identified from MRI.

RESULTS

BME lesions were identified in 56% of all knees. BME lesions were four times (95% CI=1.7, 8.7) more likely to occur in the painless OAK group as compared with the group with pain, but no OAK. BME lesions >1cm were more frequent (OR=5.0; 95% CI=1.4, 10.5) in the painful OAK group than all other groups. While the frequency of BME lesions was similar in the painless OAK and painful OAK groups, there were more lesions, >1cm, in the painful OAK group. About 75% of all knees had evidence of some cartilage defect, of which 35% were full-thickness defects. Full-thickness cartilage defects occurred frequently in painful OAK. One-third of knees with full-thickness defects and 47% of knees with cartilage defects involving bone had BME >1cm. Women with radiographic OA, full-thickness articular cartilage defects, and adjacent subchondral cortical bone defects were significantly more likely to have painful OAK than other groups (OR=3.2; 95% CI=1.3, 7.6).

CONCLUSION

The finding on MRI of subchondral BME cannot satisfactorily explain the presence or absence of knee pain. However, women with BME and full-thickness articular cartilage defects accompanied by adjacent subchondral cortical bone defects were significantly more likely to have painful OAK than painless OAK.

Responsiveness of the Problem Areas In Diabetes (PAID) questionnaire

AIM

Responsiveness (sensitivity to change over time) is a key psychometric quality for an outcome measure. We examined the responsiveness of the Problem Areas In Diabetes (PAID) questionnaire, a measure of diabetes-specific emotional distress.

METHODS

PAID data were obtained from seven diabetes intervention studies following a literature search that included both published papers and conference abstracts. To estimate responsiveness we used two indices: (i) a statistical test (the dependent t-test), and (ii) a commonly used effect size index (Cohen's d).

RESULTS

Mean patient PAID scores improved from baseline to follow-up for all seven studies. Specifically, t-statistics ranged from t= 8.5 (P < 0.001) to t= 2.1 (P < 0.06). Effect size results ranged from 0.32 (i.e. small) for a disease management intervention to 0.65 (i.e. moderate) for an intensive medical/educational intervention.

CONCLUSIONS

Despite the pilot nature of the studies, the pattern of findings provided strong support for the responsiveness of the PAID. Information on responsiveness helps clinical researchers select measures, accurately estimate sample size to ensure adequate statistical power, and prioritize outcomes to be assessed.

Prospective audit of carotid endarterectomy in Scotland

Background

Carotid endarterectomy (CEA) is a proven means of stroke prevention provided it is performed in appropriate patients, soon after the index ischaemic event and with low perioperative morbidity and mortality rates. This study investigated how well these conditions are being met in Scotland.

Methods

This was a prospective study of all 485 CEAs performed in National Health Service hospitals between 1 September 1997 and 31 September 1998. Data collection was by four independent research nurses.

Results

The median patient age was 67 (interquartile range 61–73) years; 461 patients (95 per cent) were operated on for focal symptoms, 389 of whom had a stenosis of 70 per cent or more. Some 36 per cent of patients were seen by the operating surgeon within 2 weeks of referral and 35 per cent were operated on within 1 month thereafter. The perioperative combined major stroke and death rate was 3 per cent. Operations were performed by 30 surgeons in 13 hospitals. The number of CEAs per surgeon ranged from one to 49, with ten surgeons undertaking fewer than ten operations. The number of CEAs per hospital ranged from four to 99 with only three surgeons undertaking more than 50 operations. The number of CEAs per hospital ranged from four to 99 with three hospitals undertaking 50 or more operations in the study period.

Conclusion

Despite the ‘diffuse’ nature of vascular surgical services necessitated by the demography and geography of Scotland, CEA is currently being performed with a perioperative major stroke and death rate substantially lower than that reported from randomized controlled trials. However, the overall effectiveness of surgery might be improved by reducing the delays to surgery.

The association of menopause and physical functioning in women at midlife

OBJECTIVES

To determine whether the characteristics of menstrual bleeding and the menopausal transition are associated with physical functioning in women age 40 to 55, after considering ethnicity, ability to pay for basics, body size, and age.

DESIGN

Cross-sectional study.

SETTING

Seven geographically dispersed community samples in the United States.

PARTICIPANTS

The 14,427 respondents were Caucasians (46.9%), African Americans (28.7%), Chinese (4.0%), Japanese (5.3%), and Hispanics (12.6%) from the Study of Women's Health Across the Nation (SWAN) Cross-sectional Study, a study of the menopausal transition, including surgical menopause.

MEASUREMENTS

The dependent variable was a three-category variable based on the physical functioning scale of the Medical Outcomes Study. Explanatory variables included menstrual and menopausal status.

RESULTS

Eighty percent (80.8%) of women reported no limitation in physical functioning, whereas 10% of women had some limitation, and 9.2% of women indicated having substantial limitation. Women with substantial limitation in physical functioning had double the prevalence odds ratio (POR = 2.02; 95% confidence interval (CI) = 1.64-2.49) of having surgical menopause and 76% greater odds (POR = 1.76; 95% CI = 1.38-2.24)) of using hormones, compared with women with no limitation. Compared with those without limitation, women with substantial limitation in physical functioning had 56% greater odds (POR = 1.56; 95% CI = 1.23-1.97)) of being naturally postmenopausal and a 41% greater odds (POR = 1.41; 95% CI = 1.17-1.70) of being perimenopausal, relative to being premenopausal and after adjusting for other variables.

CONCLUSION

Even at the relatively early age of 40 to 55, approximately 20% of women self-reported limitation in physical functioning. Surgical menopause and the use of hormones were more frequently observed in women with some and substantial physical limitation than in women with no limitation, even after adjusting for economic status, age, body mass index, and race/ethnicity.

An X-Y paint set and sperm FISH protocol that can be used for validation of cattle sperm separation procedures

X and Y chromosome paints were developed from sorted yak chromosomes for sexing cattle spermatozoa. Clear hybridization signals were obtained for every spermatozoon using a modified sperm decondensation protocol and fluorescence in situ hybridization (FISH). The procedure was evaluated using the established Beltsville sperm sexing technology, which separates spermatozoa by flow cytometry into X- and Y-bearing fractions. Close agreement was found between the assessment of sperm separation by flow cytometry and by FISH with the X-Y paint set. The FISH method is a simple, reliable and robust procedure for assessing the effectiveness of separation of X and Y spermatozoa.

An X-Y paint set and sperm FISH protocol that can be used for validation of cattle sperm separation procedures

X and Y chromosome paints were developed from sorted yak chromosomes for sexing cattle spermatozoa. Clear hybridization signals were obtained for every spermatozoon using a modified sperm decondensation protocol and fluorescence in situ hybridization (FISH). The procedure was evaluated using the established Beltsville sperm sexing technology, which separates spermatozoa by flow cytometry into X- and Y-bearing fractions. Close agreement was found between the assessment of sperm separation by flow cytometry and by FISH with the X-Y paint set. The FISH method is a simple, reliable and robust procedure for assessing the effectiveness of separation of X and Y spermatozoa.

Glycemic control and major depression in patients with type 1 and type 2 diabetes mellitus

The current study evaluated the association of glycemic control and major depression in 33 type 1 and 39 type 2 diabetes mellitus patients. Type 1 patients with a lifetime history of major depression showed significantly worse glycemic control than patients without a history of psychiatric illness (t = 2.09; df = 31, p < 0.05). Type 2 diabetes patients with a lifetime history of major depression did not have significantly worse control than those with no history of psychiatric illness. Findings from this study indicate different relationships between lifetime major depression and glycemic control for patients with type 1 and type 2 diabetes. Treatment implications for glycemic control in type 1 and type 2 diabetes patients are discussed.

Distinction between symptoms of voiding and filling in benign prostatic hyperplasia: findings from the Health Professionals Follow-up Study

OBJECTIVES

There is debate about the validity of the clinical distinction between filling and voiding symptoms of benign prostatic hyperplasia (BPH). We examined empirically the evidence for the existence of these clinical constructs.

METHODS

We analyzed responses to the American Urological Association Symptom Index (AUA SI) among men from a large cohort sample (the Health Professionals Follow-up Study, n = 7753) and a subsample with physician-diagnosed BPH (n = 1856). We used factor analysis, which is a data reduction tool that allowed us to determine empirically the relationships among lower urinary tract symptoms thought to be clinically related by pathogenesis, physiology, or treatment response.

RESULTS

The results of the factor analysis indicated that responses to the AUA SI items could be grouped into one of two subscales: one describing voiding problems and the other describing filling problems. Analyses of internal consistency reliability indicated that the AUA SI as well as the filling and voiding subscales have sound internal reliability.

CONCLUSIONS

We found empirical support for the clinical conceptualization of lower urinary tract symptoms into filling and voiding problems. These findings provide support for using the total score on the AUA SI as a reliable measure of overall symptom severity in BPH, as well as for separately summing the voiding and filling items to measure these distinctive types of lower urinary tract symptomatology. Further research is needed to determine whether these symptom groupings better distinguish responses to one treatment type over another. If so, targeting treatment based on the relative severity of voiding and filling symptoms might improve patient outcomes.

Reduced glutathione prevents nitric oxide-induced apoptosis in vascular smooth muscle cells

The control of medial and neointimal growth, in which vascular smooth muscle (VSM) plays a central role, is most important to the development of hypertension and atherosclerosis, respectively. Growth of vascular smooth muscle cells is regulated by a number of factors, including the vasodilator nitric oxide (NO). In addition, NO modulates intracellular thiol redox states and the thiol redox state of the cell influences NO production. We, therefore, examined the nature of the effect of NO on growth of VSM cells and its modulation by cellular glutathione content. Here, we report that NO, either generated by NO donors or synthesized by iNOS in VSM cells, inhibited DNA synthesis and induced apoptosis in this cell type. NO-induced apoptosis was associated with a significant decrease in the intracellular concentration of reduced glutathione and with an increase in the level of the tumor suppressor gene p53 mRNA. Moreover, addition of glutathione monoethylester to the culture restored the level of reduced glutathione in VSM cells, and prevented the NO-induced increase in p53 expression and programmed cell death. Our findings suggest a role for reduced glutathione in protecting VSM cells exposed to NO from apoptosis.

The association of lifetime psychiatric illness and increased retinopathy in patients with type I diabetes mellitus

Forty-nine patients with Type I diabetes mellitus were assessed to examine the relationship between lifetime prevalence of psychiatric illness and retinopathy severity. The subjects with a history of psychiatric illness had significantly worse retinopathy than the subjects without psychiatric illness. Eighty-nine percent of the subjects with severe nonproliferative retinopathy or proliferative retinopathy had a history of psychiatric illness, predominantly affective illness. In addition, the subjects with a history of psychiatric illness had significantly higher current glycohemoglobin levels than those with no psychiatric history. This study's findings suggest that psychiatric illness may be a risk factor for development of retinopathy in Type I diabetic patients.

Nitric oxide and its role in the cardiovascular system

Nitric oxide (NO) is a ubiquitous, naturally occurring molecule found in a variety of cell types and organ systems. In the cardiovascular system, NO is an important determinant of basal vascular tone, prevents platelet activation, limits leukocyte adhesion to the endothelium, and regulates myocardial contractility. NO may also play a role in the pathogenesis of common cardiovascular disorders, including hypotension accompanying shock states, essential hypertension, and atherosclerosis. In this review, we discuss the biochemistry of NO and focus on its biology and pathophysiology in the cardiovascular system.

Assessment of diabetes-related distress

OBJECTIVE

To describe a new measure of psychosocial adjustment specific to diabetes, the Problem Areas in Diabetes Survey (PAID), and to present initial information on its reliability and validity.

RESEARCH DESIGN AND METHODS

Before their routine clinic appointments, 451 female patients with type I and type II diabetes, all of whom required insulin, completed a self-report survey. Included in the survey was the PAID, a 20-item questionnaire in which each item represents a unique area of diabetes-related psychosocial distress. Each item is rated on a six-point Likert scale, reflecting the degree to which the item is perceived as currently problematic. A total scale score, hypothesized to reflect the overall level of diabetes-related emotional distress, is computed by summing the total item responses. To examine the concurrent validity of the PAID, the survey also included a series of standardized questionnaires assessing psychosocial functioning (general emotional distress, fear of hypoglycemia, and disordered eating), attitudes toward diabetes, and self-care behaviors. All subjects were assessed for HbA1, within 30 days of survey completion and again approximately 1-2 years later. Finally, long-term diabetic complications were determined through chart review.

RESULTS

Internal reliability of the PAID was high, with good item-to-total correlations. Approximately 60% of the subject sample reported at least one serious diabetes-related concern. As expected, the PAID was positively associated with relevant psychosocial measures of distress, including general emotional distress, disordered eating, and fear of hypoglycemia, short- and long-term diabetic complications, and HbA1, and negatively associated with reported self-care behaviors. The PAID accounted for approximately 9% of the variance in HbA1. Diabetes-related emotional distress, as measured by the PAID, was found to be a unique contributor to adherence to self-care behaviors after adjustment for age, diabetes duration, and general emotional distress. In addition, the PAID was associated with HbA1 even after adjustment for age, diabetes duration, general emotional distress, and adherence to self-care behaviors.

CONCLUSIONS

These findings suggest that the PAID, a brief, easy-to-administer instrument, may be valuable in assessing psychosocial adjustment to diabetes. In addition to high internal reliability, the consistent pattern of correlational findings indicates that the PAID is tapping into relevant aspects of emotional distress and that its particular feature, the measurement of diabetes-related emotional distress, is uniquely associated with diabetes-relevant outcomes. These data are also consistent with the hypothesis that diabetes-related emotional distress, separate from general emotional distress, is an independent and major contributor to poor adherence. Given that the study was limited to female patients using insulin, further examination of the clinical usefulness of the PAID will need to focus on more heterogeneous samples.

Letters

SHEEPSKINS AND PRESSURE SORE PREVENTION PROFESSIONAL SOCIETIES TREATMENT OF DEGLOVING INJURY ISCHAEMIC-INDUCED HYPOXIA.

Nitric oxide and the cardiovascular system

Nitric oxide is a simple diatomic molecule that functions as a cellular messenger in a number of organ systems, included among which is the cardiovascular system. Serving several physiologic roles in the cardiovascular system, nitric oxide is an important determinant of basal vascular tone, regulates myocardial contractility, and modulates platelet-vessel wall interactions. From the perspective of cardiovascular pathophysiology, nitric oxide has been implicated in the pathogenesis of essential hypertension, atherosclerosis, and the hypotension associated with shock states. This review will focus in detail on the chemistry, biology, and pathobiology of nitric oxide as it relates to cardiovascular function.

The BULIT-R: its reliability and clinical validity as a screening tool for DSM-III-R bulimia nervosa in a female tertiary education population

The Bulimia Test (BULIT) has been updated to accommodate the DSM-III-R criteria for bulimia nervosa. Therefore, in this study, we evaluated the psychometric properties of the BULIT-R using a sample of young women at a tertiary educational institute. The results showed all 28 BULIT-R items correlated highly with the total test score (average = .59) and the internal reliability was high (.92). In terms of its concurrent validity, the BULIT-R correlated highly (.90) with the Bulimia Investigatory Test Edinburgh (BITE), a screening measure argued to detect bulimia nervosa. In terms of criterion-related validity, the optimal cutoff for the BULIT-R as a screening measure was 98 with this sample, using a semistructured DIS-III R interview administered by experienced clinicians who specialize in eating disorders. At this cutoff, the sensitivity was 100%, the specificity 99.0%, the negative predictive value 100%, and the positive predictive value 71.3%.

Imaging through a random phase screen by enhanced backscatter: a physical interpretation

It has been shown recently that enhanced backscatter processes can be exploited in imaging diffuserobscured objects. Through the use of an interferometric measurement system it is possible to determine the modulus of the Fresnel transform of a planar reflective object that is obscured by a thin moving diffuser. In a physical interpretation of that operation presented in this paper, we think of the object as being made up of a superposition of lens-like components, each with focal power appropriate to image the diffuser back onto itself and each with an associated attenuation and phase shift. This interpretation leads to the conclusion, which is verified analytically, that the same information about the object can be obtained without making interferometric measurements, i.e., without exploiting enhanced backscatter.

CT detection of occult pneumothorax in multiple trauma patients

Chest injuries are the cause of death in 25% of trauma fatalities, and a major contributing factor in an additional 50%. Pneumothorax, the second most common chest injury, may often be initially overlooked. Administration of anesthesia and mechanical ventilation may produce enlargement of a pneumothorax and clinical deterioration. We reviewed 90 trauma patients who had been admitted with a diagnosis of pneumothorax or who had developed pneumothoraces after hospital admission. In 35 cases (38.8%), initial supine chest x-ray study failed to detect a pneumothorax, and the diagnosis was made on CT scan of the chest or abdomen performed within 2 hours of admission. In 15 of these cases (42.8%), identification of the pneumothorax on CT scan resulted in alterations in management, including chest tube placement in 10 patients and intensified monitoring in 5 patients. Failure to identify pneumothoraces in trauma patients may lead to deterioration and significant complications in patients requiring anesthesia or mechanical ventilation. CT scan may facilitate identification in these cases.

Styles of psychological adjustment in diabetes: a focus on key psychometric issues and the ATT39

While knowledge of the biomedical factors in diabetes has grown in a steady and systematic fashion over the past 60 years, attempts to define, measure, and understand the relevant psychological constructs have only begun recently. In particular, there is need for psychometrically sound tests to tap these dimensions. This study examined the psychometric characteristics of the ATT39, a promising measure of psychological adjustment to diabetes. The results, based on three patient samples and using the FACTOREP factor-matching procedure, suggested that the ATT39 has a large single factor only. This new subscale appears clinically to measure the integration of diabetes and its treatment into the lifestyle and personality of a patient with diabetes.

The evaluation of a behavioural food and weight control programme for obese patients with noninsulin dependent diabetes

We report here on the evaluation of a behaviour modification programme for food and weight control in noninsulin dependent diabetes mellitus (NIDDM). The results of this pilot study, involving a highly selected group of patients, showed that weight was reduced by an average of 4.5% over 11 weeks and that this difference was statistically significant. This average weight loss is in the range typically found for similar programmes. Glycosylated haemoglobin fell by 7.8% on average and serum total cholesterol fell by 3%, both statistically significant changes. Triglycerides fell by 17%, although this was not significant. The programme in its present form appears helpful in aiding motivated patients to make modest improvements in their blood sugars and lipids. However, we have identified a number of modifications and additions that could be made to improve it.

The replicable dimensions of the Beck Depression Inventory

Numerous studies have focused on the factor structure of the Beck Depression Inventory (BDI) because its underlying structure, once identified, may improve our conceptualizations of the cognitive processes in depression. These studies have produced a wide range of interpretations for the BDI, yet the replicability of these factor solutions across independent samples has not been demonstrated. In this study, a series of factor analyses were conducted that involved the use of a new factor matching procedure (FACTOREP), and both depressed patient and normal population samples. The results supported the presence of a large general factor only, which suggests that the items of the BDI are tapping a general construct of depressive symptoms rather than the variety of more specific constructs suggested by previous researchers.

Is the prevalence of bulimia nervosa higher among tertiary education populations?

In this study the prevalence of bulimia nervosa was estimated among 243 women in a tertiary educational setting. The results showed 43.6% (95% CI, 37.4 to 49.8) to report binge eating, the cardinal feature of bulimia nervosa, at some stage in the past and 2.5% (95% CI, 1.0 to 5.6) the full criteria for current bulimia nervosa. These figures are significantly higher than those reported recently for a general population sample in the same age range. Despite methodological differences between the two surveys the results give some support to claims that women in these settings are at a greater risk of developing eating disorders.

Australasian field trials of the Mental and Behavioural Disorders section of the draft ICD-10

Field trials of the "Mental and Behavioural Disorders" section of the 1987 draft of the ICD-10 have been co-ordinated for the World Health Organisation by a number of regional centres. The design of the field trials and the major features of ICD-10 are briefly discussed. The results of the field trial in the Western Pacific region are described, and compared with the results of the original DSM-III field trials. ICD-10 appears to be an acceptably reliable diagnostic system, and the ratings of its feasibility and utility by participating clinicians suggest that it will be seen as a distinct advance over ICD-9.

'Normal but dead': perinatal mortality in non-malformed babies of birthweight 2.5 kg and over in the northern region in 1983

The case notes relating to 75 of the 91 perinatal deaths of nonmalformed babies of birthweight greater than or equal to 2.5 kg born in the Northern Region in 1983 were examined. The major groups involved antepartum deaths of unknown cause (40%), and deaths due to intrapartum anoxia or trauma (35%). A case-control study compared each of the 75 cases with two controls matched for place of birth, obtained by taking the next two babies born in the same maternity unit (excluding perinatal deaths, birthweight less than 2.5 kg, and malformations). Four factors were found to be significantly associated with risk of perinatal death in this group: primigravidity, parity greater than or equal to 3, not booked for antenatal care by 20 weeks, and corrected birthweight less than 3.2 kg (adjusted for gestation). Two further factors were related only to the risk of perinatal death consequent upon intrapartum events: labour post-term and malpresentation in labour. All four factors relevant to the whole group remained independently associated with risk of perinatal death after multivariate analysis by two techniques. Adjusted odds ratios (95% CI) were estimated as: primigravidity 2.1 (1.1 to 4.1); parity three or more 5.7 (1.9 to 17); not booked for antenatal care by 20 weeks 15.7 (3.0 to 81); and corrected birthweight less than 3.25 kg 2.5 (1.3 to 4.6). An avoidable factor, as defined, was detected in 50% of deaths. In 30% of deaths there was an avoidable factor (grade 2) such that absence may have been expected to lead to a different outcome had all other factors remained equal. Of the avoidable factors detected, 61% related to intrapartum management, as did 76% of the grade 2 factors. Most of these involved failure to respond to evidence of fetal distress in labour. The defined group constituted 21% of all perinatal deaths, suggesting that this is an important category, particularly as their potential for normal survival should otherwise have been high.

The reliability and discriminant validity of three potential measures of bulimic behaviours

There is currently a need for a reliable and valid self-report measure of bulimic behaviours that is brief and economical to administer and that can be used to assess response to treatment and to investigate correlates of bulimic symptoms. Three potential screening measures of bulimic behaviours (the Bulimia Test, the Conroy-Healy Eating Questionnaire and the Bulimia subscale of the Eating Disorder Inventory) were evaluated using internal consistency analysis and Receiver (or Relative) Operating Characteristic curve analysis, to determine their internal reliability and ability correctly to identify bulimic patients seen at an eating disorders outpatients clinic. The results showed that the three measures examined were all good discriminators of bulimic and non-bulimic patients. However, the results showed that the Bulimia Test was clearly the most reliable measure, apparently because of its greater length. It is suggested that further investigations be conducted to establish the sensitivity of the Bulimia Test to changes in the severity of bulimic behaviours in patients, since this will increase knowledge of its utility as a measure of response to treatment.

The factor structure of the eating disorders inventory

The Eating Disorders Inventory (EDI) is a promising new measure of the cognitive and behavioral characteristics of anorexia nervosa and bulimia, although the replicability of its eight subscales has not been evaluated. Therefore, a factor analysis of the EDI was carried out that used the FACTOREP procedure. The results, using non-patient responses, did not confirm the original eight subscales, but did show three clear and replicable factors to exist. It was suggested that these may be of clinical value as preliminary screening measures or as indices of response to treatment, although further validation would be required to establish their utility.

Mitochondrial DNA of two independent oligomycin-resistant Chinese hamster ovary cell lines contains a single nucleotide change in the ATPase 6 gene

We have determined the nucleotide sequence of the URF A6L and ATPase 6 genes of the mitochondrial DNA of wild-type Chinese hamster ovary (CHO) cells and of two independently isolated, cytoplasmically inherited CHO mutant cell lines that are resistant to oligomycin, an inhibitor of the mitochondrial ATP synthase (ATPase) complex. Comparison of the nucleotide sequences of the mutants with that of their parental cell line revealed a single nucleotide difference, a G-to-A transition at nucleotide 433 of the ATPase 6 gene. This single base pair change predicts a nonconservative amino acid change, with a glutamic acid residue being replaced by a lysine residue at amino acid 145 of the ATPase 6 gene product in the mutants. This glutamic acid residue and several others in the surrounding amino acid sequence are conserved among all species examined to date. Analyses of several of the biochemical properties of the oligomycin-resistant CHO mutants indicate that the glutamic acid residue at position 145 of subunit 6 of the mitochondrial ATP synthase complex is important for the binding of oligomycin to the enzyme complex, but is not essential for proton translocation.

Investigation of 'weight pathology' of 58 mothers of anorexia nervosa patients and 204 mothers of schoolgirls

'Weight pathology'--defined by Kalucy et al. (1977) as 'deviations in weight, shape, eating behaviour and activity'--has been hypothesized to be unduly common in families with anorexia nervosa. It was investigated in this study by means of questionnaires evaluating both weight history and attitudes towards weight-related matters in 58 mothers of anorexia nervosa patients and 204 mothers of schoolgirls of similar age and socioeconomic status (SES). No support was found for the hypothesis. A family history of aberrant weight and mother's current weight and past weight histories showed no significant differences between the groups. 142 other mothers of schoolchildren and 446 attenders at Weight Watchers also completed the questionnaire on attitudes towards weight-related matters. Mothers of patients showed a lower concern on all scales than did all other groups. The findings are discussed in relation to earlier controlled studies of family factors in anorexia nervosa.

Response of cultured mammalian cells to accelerated krypton particles

One of the more interesting observations made in early studies with heavy ions is that the cross-section of the radiosensitive area in mammalian cells increases with LET of HZE particles. It is not certain, however, whether this radiosensitive area is limited to the nuclear area of cells. The successful acceleration of krypton ions to 8.5 MeV/amu at the HILAC Lawrence Berkeley Laboratory, has provided an opportunity to gain more information on this question. Cultured human kidney cells (T-1), growing in exponential phase, were exposed to 3 MeV/amu krypton particles and their colony-forming ability studied. The survival curve was found to be exponential with a mean lethal dose D0=720 rad. A calculation of the cross-section of the radio-sensitive area from the data obtained gives a value of about 145 micrometers2. Present results suggest that the inactivation cross-section stays about the same for heavy ions that have LET greater than 20,000 MeV cm2 g-1, that the nucleus is the only sensitive site for high LET radiation and that a single hit of a heavy ion with very high LET in the nuclear region of the cell can lead to lethal effects. Such particles are therefore extremely dangerous to proliferating living cells.

Effects of high-LET particles (40A) on the brain of Drosophila melanogaster

To investigate the effects of galactic heavy particles on nervous tissue, Drosophila melanogaster flies were exposed to 40A from the Super-HILAC accelerator at the Lawrence Berkeley Laboratory. The energy of the particles reaching the Drosophila neurons was 4-8 MeV/nucleon, and the fluence ranged from 6 X 10(4) to 8 X 10(7) particles/cm2. Thirty-five days after irrdiation at the higher fluences, extensive tissue fragmentation and cysts were found. At fluences as low as one hit/two cell bodies (about 5 X 10(6)) and one hit/90 cell bodies (about 9 X 10(4) particles/cm2 or 21 rad average dose) swelling of neuronal cytoplasm and focally fragmented membranes were noted; at fluences ranging from one hit/six to one hit/135 cell bodies, there was frequently a marked increase in glial lamellae around nerve-cell processes, which often had degenerative features. These findings support the view that single hits by heavy particles may injure nervous tissue.