Diagnostic and Predictive Applications of Functional Near-Infrared Spectroscopy for Major Depressive Disorder: A Systematic Review

INTRODUCTION

Major depressive disorder (MDD) is a global psychiatric disorder with no established biomarker. There is growing evidence that functional near-infrared spectroscopy (fNIRS) has the ability to aid in the diagnosis and prediction of the treatment response of MDD. The aim of this review was to systematically review, and gather the evidence from existing studies that used fNIRS signals in the diagnosis of MDD, correlations with depression symptomatology, and the monitoring of treatment response.

METHODS

PubMed, EMBASE, ScienceDirect, and Cochrane Library databases were searched for published English articles from 1980 to June 2019 that focused on the application of fNIRS for (i) differentiating depressed versus nondepressed individuals, (ii) correlating with depression symptomatology, and in turn (iii) monitoring treatment responses in depression. Studies were included if they utilized fNIRS to evaluate cerebral hemodynamic variations in patients with MDD of any age group. The quality of the evidence was assessed using the Newcastle-Ottawa quality assessment scale.

RESULTS

A total of 64 studies were included in this review, with 12 studies being longitudinal, while the rest were cross-sectional. More than two-thirds of the studies (n = 49) had acceptable quality. fNIRS consistently demonstrated attenuated cerebral hemodynamic changes in depressed compared to healthy individuals. fNIRS signals have also shown promise in correlating with individual symptoms of depression and monitoring various treatment responses.

CONCLUSIONS

This review provides comprehensive updated evidence of the diagnostic and predictive applications of fNIRS in patients with MDD. Future studies involving larger sample sizes, standardized methodology, examination of more brain regions in an integrative approach, and longitudinal follow-ups are needed.

P1925Machine learning versus classic electrocardiographic criteria for left ventricular hypertrophy in a young pre-participation cohort: results from the SAFE protocol study

Background/Introduction

Classic electrocardiographic (ECG) criteria for left ventricular hypertrophy (LVH) have been well studied in Western populations, particularly in hypertensive patients. However, their utility in Asian populations is not well studied, and their applicability to young pre-participation cohorts is unclear. We sought to evaluate the performance of classical criteria against that of machine learning models.

Aims

We sought to evaluate the performance of classical criteria against the performance of novel machine learning models in the identification of LVH.

Methodology

Between November 2009 and December 2014, pre-participation screening ECG and subsequent echocardiographic data was collected from 13,954 males aged 16 to 22, who reported for medical screening prior to military conscription.

Final diagnosis of LVH was made on echocardiography, with LVH defined as a left ventricular mass index >115g/m2. The continuous and binary forms of classical criteria were compared against machine learning models using receiver-operating characteristics (ROC) curve analysis. An 80:20 split was used to divide the data into training and test sets for the machine learning models, and three fold cross validation was used in training the models. We also compared the important variables identified by machine learning models with the input variables of classical criteria.

Results

Prevalence of echocardiographic LVH in this population was 0.91% (127 cases). Classical ECG criteria had poor performance in predicting LVH, with the best predictions achieved by the continuous Sokolow-Lyon (AUC = 0.63, 95% CI = 0.58–0.68) and the continuous Modified Cornell (AUC = 0.63, 95% CI = 0.58–0.68). Machine learning methods achieved superior performance – Random Forest (AUC = 0.74, 95% CI = 0.66–0.82), Gradient Boosting Machines (AUC = 0.70, 95% CI = 0.61–0.79), GLMNet (AUC = 0.78, 95% CI = 0.70–0.86). Novel and less recognized ECG parameters identified by the machine learning models as being predictive of LVH included mean QT interval, mean QRS interval, R in V4, and R in I.

ROC curves of models studies

Conclusion

The prevalence of LVH in our population is lower than that previously reported in other similar populations. Classical ECG criteria perform poorly in this context. Machine learning methods show superior predictive performance and demonstrate non-traditional predictors of LVH from ECG data. Further research is required to improve the predictive ability of machine learning models, and to understand the underlying pathology of the novel ECG predictors identified.

Stenosis detection and quantification on cardiac CTCA using panoramic MIP of coronary arteries

In this work, we proposed to demonstrate the entire 3D coronary tree using panoramic maximum intensity projection (MIP) of coronary arteries, and to detect and quantify coronary stenosis from computed tomography coronary angiography (CTCA). The performance of the proposed method was assessed in comparison with invasive coronary angiography (ICA) as reference standard. Six anonymized CTCA datasets were tested. MIP method achieved a sensitivity of 82% and a specificity of 95% for the stenosis detection with a good reproducibility (i.e. Cohen's kappa coefficient of 0.74 for the intra-rater agreement, and 0.45 for the inter-raters agreement). In stenosis quantification, three image options are provided. The original density images resulted in an accuracy of 0.85. The edge map images resulted in an accuracy of 0.79. The image combination had a better accuracy of 0.89 than any single image option. In conclusion, the panoramic MIP provided fast and accurate way for the stenosis detection and quantification. It may be helpful to assist the radiologist in identifying the location of the greatest narrowing in clinical practice.

Left ventricular wall stress compendium

Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models.

Impact of surgical ventricular restoration on ventricular shape, wall stress, and function in heart failure patients

Surgical ventricular restoration (SVR) was designed to treat patients with aneurysms or large akinetic walls and dilated ventricles. Yet, crucial aspects essential to the efficacy of this procedure like optimal shape and size of the left ventricle (LV) are still debatable. The objective of this study is to quantify the efficacy of SVR based on LV regional shape in terms of curvedness, wall stress, and ventricular systolic function. A total of 40 patients underwent magnetic resonance imaging (MRI) before and after SVR. Both short-axis and long-axis MRI were used to reconstruct end-diastolic and end-systolic three-dimensional LV geometry. The regional shape in terms of surface curvedness, wall thickness, and wall stress indexes were determined for the entire LV. The infarct, border, and remote zones were defined in terms of end-diastolic wall thickness. The LV global systolic function in terms of global ejection fraction, the ratio between stroke work (SW) and end-diastolic volume (SW/EDV), the maximal rate of change of pressure-normalized stress (dσ*/dt(max)), and the regional function in terms of surface area change were examined. The LV end-diastolic and end-systolic volumes were significantly reduced, and global systolic function was improved in ejection fraction, SW/EDV, and dσ*/dt(max). In addition, the end-diastolic and end-systolic stresses in all zones were reduced. Although there was a slight increase in regional curvedness and surface area change in each zone, the change was not significant. Also, while SVR reduced LV wall stress with increased global LV systolic function, regional LV shape and function did not significantly improve.

An unusual case of vascular hypogonadism treated with clomiphene citrate and testosterone replacement

Many male patients are discovered on screening to suffer from hypogonadism and age related hypogonadism is being increasingly recognized. However, secondary causes of hypogonadism should not be overlooked, especially in patients who may have concomitant morbidity as highlighted in this case. Our patient with vascular hypogonadism was treated with testosterone and clomiphene citrate in cycles; with a hope of improving not only androgen levels but overall pituitary function as there were co-existing endocrine pathologies of albeit primary hypothyroidism and low IGF-1 levels. Treatment with exogenous testosterone is fairly well established; but there is also increasing evidence of the effectiveness and short-term safety of clomiphene citrate in restoring not only biological levels but functional states in males as well. As such, we report an unusual case of a patient seen at our Men's Health & Andrology clinic in which both the cause of some otherwise unremarkable symptoms and the treatment, using a combination of clomiphene citrate and testosterone, were remarkable.

Anabolic steroid-induced hypogonadism--towards a unified hypothesis of anabolic steroid action

Anabolic steroid-induced hypogonadism (ASIH) is the functional incompetence of the testes with subnormal or impaired production of testosterone and/or spermatozoa due to administration of androgens or anabolic steroids. Anabolic-androgenic steroid (AAS), both prescription and nonprescription, use is a cause of ASIH. Current AAS use includes prescribing for wasting associated conditions. Nonprescription AAS use is also believed to lead to AAS dependency or addiction. Together these two uses account for more than four million males taking AAS in one form or another for a limited duration. While both of these uses deal with the effects of AAS administration they do not account for the period after AAS cessation. The signs and symptoms of ASIH directly impact the observation of an increase in muscle mass and muscle strength from AAS administration and also reflect what is believed to demonstrate AAS dependency. More significantly, AAS prescribing after cessation adds the comorbid condition of hypogonadism to their already existing chronic illness. ASIH is critical towards any future planned use of AAS or similar compound to effect positive changes in muscle mass and muscle strength as well as an understanding for what has been termed anabolic steroid dependency. The further understanding and treatments that mitigate or prevent ASIH could contribute to androgen therapies for wasting associated diseases and stopping nonprescription AAS use. This paper proposes a unified hypothesis that the net effects for anabolic steroid administration must necessarily include the period after their cessation or ASIH.

Preference for gender of health care provider in management of erectile dysfunction

We investigated whether a preference by patients regarding the gender of a health care provider to manage erectile dysfunction (ED) may be a factor in the diagnosis and care of this condition, whose broader medical significance is an area of increasing interest. A brief questionnaire was completed by 1087 adult males in a primary care setting. The questionnaire explored provider gender preference and other possible biases. The prevalence of ED in the 40-69 age group in our population was 68.8%. The prevalence was 81% in the age group of 70 and more. Of those who reported having experienced ED, 51.5% had discussed it with a provider, and 28.1% had been treated. Approximately, 57% expressed no provider gender preference, regardless of history of ED. Of those who stated a preference, approximately 75% prefer male providers. However, also among those who state a preference, Hispanics are not as likely as non-Hispanics to prefer a male provider (P=0.03). Most believe that males and females are equally qualified to manage ED, but among those who have a different opinion, the gender perceived more favorably is male. The issue of privacy during the discussion of ED was also very important to the respondents in this study.

Risks of testosterone replacement therapy in ageing men

Testosterone has been available to practitioners for several decades. However, testosterone prescriptions have increased in recent years partly because of the introduction of newer delivery systems that are topical and have good bioavailability. In the US alone, approximately 2 million prescriptions for testosterone were written in 2002. This represents a 30% increase from 2001 and a 170% increase from 1999. There has also been a 500% increase in prescription sales in the past 10 years. The rise in prescriptions may be in part due to the increasing recognition of hypogonadism in ageing males or andropause. Treatment relating to hypogonadism has relieved symptoms and improved the quality of life of many individuals. Epidemiological studies point toward an association with increased morbidity and mortality, with low testosterone states in ageing males. For example, there is a higher prevalence of depression, coronary heart disease, osteoporosis, fracture rates, frailty and even dementia with low testosterone states. Recently, there have been some concerns raised regarding the long-term safety of testosterone replacement therapy (TRT) from the Institute of Medicine. Current evidence suggests no causal relationship between prostate cancer and physiological dosing of testosterone, especially with careful selection and monitoring of patients. Cardiovascular risks have, overall, been neutral, although suggestions have been made that there are positive vasodilatory properties with testosterone. Mild eythrocytosis can be a common side effect of TRT, but thromboembolic events have rarely been reported in the literature. This paper addresses the evidence to date regarding the safety aspects of TRT. The medical-legal implications of TRT for men at this point in time is also discussed.

Glagov remodeling of the atherosclerotic aorta demonstrated by cardiovascular magnetic resonance: the CORDA asymptomatic subject plaque assessment research (CASPAR) project

BACKGROUND

Aortic atherosclerosis and coronary artery disease (CAD) are closely linked. Early detection of aortic atherosclerosis with the adoption of appropriate preventive measures may therefore help to reduce mortality and morbidity related to CAD. Arterial remodeling, by which the wall adapts to physiological or pathological insults by a change in vessel size, is being increasingly recognized as an important aspect of atherosclerosis. In this prospective longitudinal study we used cardiovascular magnetic resonance (CMR) to detect aortic plaque and to study aortic wall remodeling in asymptomatic subjects.

METHODS

We recruited 175 healthy volunteers (49 years, 110 men) and documented their cardiovascular risk profile. Each subject underwent echocardiogram (ECG)-gated T1-weighted spin-echo imaging of the infrarenal abdominal aorta at baseline and after 2 years.

FINDINGS

Of the 175 subjects who volunteered at baseline, CMR was successful in 174 (99%), with one (0.6%) failure due to claustrophobia. At 2 years, follow-up scanning was performed in 169 subjects (97%). Infrarenal aortic plaque was identified at baseline in nine (5.2%) subjects. This was reconfirmed in all nine (100%) cases at 2-year follow-up. No new cases of infrarenal plaque were identified at follow-up. The signal characteristics of the plaque on the subtracted images of the Dixon method indicate that all plaques were fibrous. In the nine subjects with infrarenal plaque, the total plaque burden increased as assessed by the total wall volume (561 to 677 mm3, p = 0.0063). The total vessel volume also increased (1737 to 1835 mm3, p = 0.031) but there was no change in the total luminal volume (1175 to 1157 mm3, p = 0.29).

CONCLUSIONS

Cardiovascular magnetic resonance detects subclinical aortic atherosclerosis, can follow plaque burden over time, and confirms the presence of Glagov remodeling with preservation of the lumen despite progression of plaque. Cardiovascular magnetic resonance is well suited for the longitudinal follow-up of the general population with atherosclerosis, may help in the understanding of the natural history of atherosclerosis, and in particular may help determine factors to retard disease progression at an early stage.

Coronary artery disease: comprehensive evaluation by cardiovascular magnetic resonance imaging

Cardiac magnetic resonance (CMR) imaging has emerged as an important non-invasive cardiac imaging modality. A versatile technique, it has the potential for comprehensive evaluation of coronary artery disease (CAD): cardiac morphology and function, myocardial perfusion, myocardial viability, coronary artery visualisation and atherosclerotic plaque characterisation. Some of these techniques--ventricular function and myocardial viability assessment--have already made mainstream clinical impact. Other techniques have yielded promising initial results, and will become increasingly accepted with technical refinement in scanner hardware and software. This article reviews the current status of clinical CMR imaging for diagnosis of CAD.

Role of androgens in mild cognitive impairment and possible interventions during andropause

Mild cognitive impairment (MCI) is becoming fashionable as a diagnosis, representing a state of cognitive decline associated with negligible functional loss. MCI is important as it often precedes Alzheimer's disease (AD). Recognizing MCI may lead to preventive strategies that can delay the onset of AD. Many patients who transition into andropause report problems with their memory. There is strong evidence from basic sciences and epidemiological studies that both estrogens and androgens play a protective role in neurodegeneration. The evidence from small prospective clinical trials lends support to the role of hormones in improving cognitive function. The improvement in cognitive function with hormones is subtle and often not measurable on standard neuropsychological batteries. Patients have reported memory improvements in both declarative and procedural domains after being on hormonal replacement. Functional changes and vascular changes can be detected after hormonal replacement with more sophisticated imaging of the brain like PET scans. We hypothesize androgens and perhaps selective androgen receptor modulators as future treatment options for MCI in aging males.

Role of androgens in mild cognitive impairment and possible interventions during andropause

Mild cognitive impairment (MCI) is becoming fashionable as a diagnosis, representing a state of cognitive decline associated with negligible functional loss. MCI is important as it often precedes Alzheimer's disease (AD). Recognizing MCI may lead to preventive strategies that can delay the onset of AD. Many patients who transition into andropause report problems with their memory. There is strong evidence from basic sciences and epidemiological studies that both estrogens and androgens play a protective role in neurodegeneration. The evidence from small prospective clinical trials lends support to the role of hormones in improving cognitive function. The improvement in cognitive function with hormones is subtle and often not measurable on standard neuropsychological batteries. Patients have reported memory improvements in both declarative and procedural domains after being on hormonal replacement. Functional changes and vascular changes can be detected after hormonal replacement with more sophisticated imaging of the brain like positron emission tomography (PET) scans. We hypothesize androgens and perhaps selective androgen receptor modulators as future treatment options for MCI in aging males.

A pilot study on the effects of testosterone in hypogonadal aging male patients with Alzheimer's disease

The male aging process brings about declines in hormonal function including a gradual decline in bioavailable testosterone levels. Animal studies suggest that testosterone modulates cognitive function through enhancing acetylcholine release and up-modulation of nicotinic receptors. Tau protein deposition is also affected by androgen supplementation in animals. We hypothesize that testosterone replacement in elderly hypogonadal males may improve cognition, in particular the visual-spatial domain. Thirty-six male patients with a new diagnosis of Alzheimer's disease had their total and bioavailable testosterone levels measured. None of the patients had been on acetylcholinesterase inhibitors. Ten of the 36 patients (28%) were deemed biochemically hypogonadal (total testosterone < 240 ng/dl or 7 nmol/l). Five of the hypogonadal patients were randomized to testosterone and five to placebo. Initial Alzheimer's Disease Assessment Scale cognitive subscale (ADAScog) and Mini Mental Status Examination (MMSE) ranged from 31 to 19 and from 17 to 22, respectively. The clock drawing test (CDT) and the pentagon-tracing portion of the MMSE were used as measures of visual-spatial abilities. Normal prostate-specific antigen (PSA) levels were essential before treatment with intramuscular testosterone, 200 mg every 2 weeks. Measurement of testosterone, complete blood count, lipids, PSA and neuropsychological cognitive tests were repeated at 3, 6, 9 and 12 months of treatment. In the testosterone-treated group, levels of total testosterone increased from a mean of 126.4 ng/dl to 341 ng/dl or 3.6 nmol/l to 9.7 nmol/l (p = 0.11). Bioavailable testosterone also increased from a mean of 48.7 ng/dl to 142 ng/dl or 1.39 nmol/l to 4.05 nmol/l (p = 0.10). PSA levels were also elevated from a mean of 0.98 to 1.37 ng/ml (p = 0.07). ADAScog improved from a mean of 25 to 16.3 (p = 0.02); MMSE improved from a mean of 19.4 to 23.2 (p = 0.02), CDT also improved from 2.2 to 3.2 (p = 0.07). One patient stopped treatment because of hypersexual behavior. The placebo-treated group deteriorated gradually. This small pilot study performed in aging male patients suggests that testosterone could indeed improve cognition, including visual-spatial skills in mild to moderate Alzheimer's disease.

Impact of obesity on hypogonadism in the andropause

Obesity is an issue that is increasingly affecting ageing men. With ageing, there is a decline in androgens as well. There are implications for the health of ageing men as a result of hypogonadism. Overall, there seems to be an inverse relationship between body mass index and testosterone levels, as is also demonstrated in our cross-sectional study. Obesity seems to depress the production of testosterone. It has been hypothesized that there is increased aromatization of testosterone to oestradiol and alteration of the hypothalamic-pituitary-adrenal axis in obese older men. Some hormones can affect obesity in ageing men including leptin, insulin, dehydroepiandrostenedione and growth hormone. The relationship of obesity to these hormones in ageing men will be reviewed. Testosterone replacement in ageing men can alter body composition whereby fat is exchanged for muscle. These studies will also be reviewed. Further studies in this field are recommended to evaluate long-term benefits and risks.

Memory loss as a reported symptom of andropause

Andropause seem to be less defined than menopause. This study on older patients describes how they perceive and understand this aging process. A noninterventional, cross-sectional study was performed to determine what men report as symptoms of andropause to ascertain if memory loss was a predominant feature. The hypothesis was that androgens such as testosterone are responsible for visual-spatial and memory development. As such the aging process of andropause, which is associated with declines in testosterone levels, would lead to memory loss. A standardized questionnaire of 22 questions was administered to 302 outpatients of a medical center. Information on patient demographics, understanding of andropause, and risk factors was collected. Of the 302 patients, 71% were above 60 years and whites predominated at 87%. Memory loss was reported in 36% of the patients who felt that they had experienced andropause. It was the third most common symptom after erectile dysfunction (46%) and general weakness (41%). Twenty-two percent of the 302 patients had a history of diabetes. Among those who reported that they had undergone andropause, diabetic patients were more likely to report memory loss (p = .03, OR = 1.9. CI = 1.1-3.4). Sixty-four percent of patients reported the onset of andropause to be between 50 and 70 years (the median age being 50-60 years). This study highlights the importance of testosterone in maintaining cognitive functions. It supports studies of testosterone replacement in men undergoing andropause and who have concomitant dementia. The results parallel recent reports of the neuroprotective effects of estrogens in preventing dementia. Diabetes is associated with memory loss because of the additional insults to cognitive function of the brain secondary to ischemia.

The andropause and memory loss: is there a link between androgen decline and dementia in the aging male?

Studies demonstrate a decline in androgens with age and this results in the andropause. The objective of this paper is to review the literature on hormonal changes that occur in the aging males and determine if there are associations between decreased testosterone, dehydroepiandrosterone (DHEA) and decreased cognitive function. Trials of androgen replacement and its impact on cognitive function will also be analyzed. Method of analysis will be by a thorough search of articles on MEDLINE, the Internet and major abstract databases. Results of the author's own research in 302 men of the association of memory loss as a symptom in the andropause will be presented. In addition, the authors open trial of testosterone replacement in hypogonadic men with Alzheimer's disease will also be presented. The results of the author's trial will be compared with other investigators. High endogenous testosterone level predicted better performance on visual spatial tests in several studies, but not in all studies. Likewise, testosterone replacement in hypogonadic patients improved cognitive functions in some but not all studies. Testosterone has also been shown to improve cognitive function in eugonadal men. Several studies have shown that declines in DHEA may contribute to Alzheimer's disease and the results of double blind studies with DHEA replacement and its effect on cognition will also be presented. In summary, there is still no consensus that androgen replacement is beneficial in cognitive decline but this option may prove promising in some patients.

Cardiovascular applications of magnetic resonance flow measurement

Magnetic resonance flow measurement is a technique that can be applied in many areas of cardiovascular diagnosis. It is unique in its ability to acquire comprehensive velocity and spatial information, which makes it an accurate quantitative tool. In the evaluation of valvular heart disease and congenital heart disease, use of MR flow imaging is well established. In the assessment of coronary artery disease, MR quantification of coronary flow, in conjunction with other MR techniques, makes MR imaging a highly versatile diagnostic imaging modality. This article will review the clinical applications of MR flow measurement, as well as cover some of the basic physical principles underlying the technique, and the associated technical limitations.

Differential interleukin-10 expression in interferon regulatory factor-1 deficient mice during Plasmodium berghei blood-stage infection

Mice deficient of functional interferon regulatory factor-1 (IRF-1-/-) by targeted gene disruption infected with a lethal murine malaria strain, Plasmodium berghei ANKA survived longer than its wild-type littermates despite the inability to induce appreciable amounts of interferon-gamma (IFN-gamma) and nitric oxide. In addition, infected IRF-1-/- mice displayed less organ injury with reduced necrosis and inflammation. Both wild-type and IRF-1-/- mice treated with exogenous interleukin-12 (IL-12) suffered extensive organ damage with corresponding up regulation of IFN-gamma, suggesting the pathogenic potential of IL-12 and IFN-gamma. IL-10 is a cytokine produced by CD4+ T lymphocytes belonging to the Th2 subset. Expression of IL-10 in the wild-type mice correlated with the severity of the infection, with higher mRNA expression towards the later stage of infection. In contrast to the wild-type mice, IL-10 levels in the IRF-1-/- mice were induced early in the infection and decreased gradually as the infection progressed. Both untreated and IL-12 treated wild-type mice appeared to follow a Th1-like immune response early in the infection and a Th2-like immune response later in the infection. However, the IRF-1-/- mice were able to launch an altered immune response with a Th2-like immune response early in the infection. These findings suggest that IL-10 expression in the IRF-1-/- mice during the early stage of P. berghei ANKA infection could play an important role in suppressing pathogenic effects of a cell mediated immune response and promoting protective immunity against the parasite.

Perceptions of and risk factors for andropause

There has been some controversy about whether males undergo andropause (male equivalent of a menopause). This study seeks to describe how older males perceive and understand this entity. It also explores the possibility of an association between the age of onset of andropause and risk factors such as ethnic origin, smoking, alcohol, hypertension, and cerebrovascular disease. A nonexperimental, cross-sectional study was conducted at the outpatient clinic at a Veterans Affairs Medical Center. Subjects were interviewed by a single investigator and answered a questionnaire consisting of 22 items, including information on patient demographics, patient understanding of andropause, patient understanding of possible interventions with hormonal therapy, medical and drug history, and social habits such as smoking and drinking. Altogether 302 male patients were recruited: 71% of the survey population were above the age of 60 years, and 87% were white, 6% Hispanic, and 5% black. Patient knowledge of andropause was lacking, though the majority (70%) expressed an interest in getting further knowledge. The most frequent age for onset of symptoms related to andropause was 51-60 years, and patients reported symptoms such as impotence, weakness, and memory loss. The next most common age associated with onset was 61-70 years. Multivariate regression analysis revealed that smoking more than 10 cigarettes a day was independently associated with an earlier onset of andropause symptoms bringing down the age of onset to below 50 years (p = .01, OR = 2.5, CI = 1.2-5.3). We found no association with risk factors such as ethnicity or alcohol. Andropause is experienced by many older males but knowledge of the entity is nonuniform. Smokers are at risk for an earlier onset of andropause. This is the first study to look at risk factors for andropause and the results are consistent with studies in females on smoking and menopause.

Perceptions of and risk factors for andropause

There has been some controversy about whether males undergo an andropause (male equivalent of a menopause). This study seeks to describe how older males perceive and understand this entity and whether there is an association between the age of onset of andropause and risk factors such as ethnic origin, smoking, alcohol, hypertension, and cerebrovascular disease. A nonexperimental, cross-sectional study was conducted at the outpatient clinic at a Veterans Affairs Medical Center. Subjects were interviewed by a single investigator and administered a questionnaire consisting of 22 items, including information on patient demographics, patient understanding of the andropause, patient understanding of possible interventions with hormonal therapy, medical, and drug history, and social habits such as smoking and drinking. Altogether 302 male patients were recruited, 71% of which were above the age of 60 years, and 87% were white, 6% were Hispanic, and 5% were black. The knowledge of patients toward the entity of andropause was lacking, though the majority (70%) expressed an interest in getting further knowledge. The most frequent age of onset of symptoms related to andropause was 51-60 years, and patients reported symptoms such as impotence, weakness, and memory loss. The next most common age reported to he associated with age of onset was 61-70 years. Multivariate regression analysis reveals that smoking more than 10 cigarettes a day was independently associated with an earlier onset of symptoms of andropause, bringing down the age of onset to below 50 years (p = .01, OR = 2.5, CI = 1.2-5.3). We found no association with risk factors such as ethnicity and alcohol. Andropause is experienced by many older males but knowledge of the entity is nonuniform. Older males are at risk for an earlier onset of andropause if they were smokers. This is the first study looking at risk factors for andropause and the results are consistent with studies in females on smoking and menopause.

Altered immune response of interferon regulatory factor 1-deficient mice against Plasmodium berghei blood-stage malaria infection

Nitric oxide (NO) is a short-lived biological mediator which can be induced in various cell types and is able to cause many metabolic changes in target cells. Inhibition of tumor cell growth and antimicrobial activity has been attributed to the stimulation of NO production by transcriptional upregulation of inducible nitric oxide synthase. In the present study, we used mice devoid of functional interferon regulatory factor 1 by targeted gene disruption (IRF-1(-/-)) to investigate the role of NO in the host immune response against blood-stage Plasmodium berghei ANKA infection. IRF-1(-/-) mice survived longer with a later onset of and a lower peak parasitemia despite the inability to produce appreciable levels of NO. The administration of exogenous interleukin-12 (IL-12) was able to prolong survival in the wild-type mice with an upregulation in the expression of both gamma interferon (IFN-gamma) and NO. However, the administration of IL-12 did not improve the survival of IRF-1(-/-) mice. These studies indicate that while IL-12 is able to mediate protection via an IFN-gamma- and NO-dependent pathway in the wild-type mice, such a protective mechanism may not be functional in the IRF-1(-/-) mice. Our results suggest that NO may not be essential for host immunity to the parasite and that IRF-1(-/-) mice are able to induce an IFN-gamma- and NO-independent mechanism against P. berghei infection.

Goldberger's triad in dilated cardiomyopathy--can it predict the severity of left ventricular dysfunction?

Goldberger's triad is a specific, but relatively insensitive, electrocardiographic sign for dilated cardiomyopathy. To study the correlation between the presence of this sign and the severity of left ventricular dysfunction, the electrocardiograms and echocardiographically-determined left ventricular parameters of 17 patients (mean age 59.3 +/- 11.8 years) with dilated cardiomyopathy were examined. Five of the patients had Goldberger's triad. We found that the mean left atrial diameter, the mean left ventricular internal diameters (both end-systolic and end-diastolic) and the mean left ventricular ejection fraction of the group of patients with Goldberger's triad did not differ significantly from the group without. Coronary angiography revealed occult coronary artery disease in 5 of 12 patients. A larger, prospective study is required to verify our finding.

The Brugada syndrome in a Chinese population

Sudden cardiac death has been reported in patients with a unique electrocardiographic (ECG) abnormality showing right bundle branch block and ST segment elevation in the precordial leads. This syndrome was first described by Brugada and Brugada and has not been previously described in a Chinese population. We report here the first three cases in Singapore. The first patient was a 49-year-old man who presented with syncope, associated with generalized convulsions. The second patient was a 25-year-old man who complained of palpitations but no syncope. The third patient was a 77-year-old man who presented with recurrent episodes of syncope and collapsed with ventricular fibrillation. All patients had no past cardiac or drug history of note. The neurological examination and investigations were normal. All three patients showed a unique right bundle branch block pattern with ST segment elevation in leads V1-3. The echocardiogram and 24-h ambulatory ECG monitoring, were normal. Single vessel disease was present in the third patient. Electrophysiological studies performed in all three patients were able to induce ventricular fibrillation. The patient with resuscitated cardiac death underwent an implantable cardioverter defibrillator implantation. The importance of this syndrome is that the recognition of the unique ECG pattern enables early identification and treatment of these patients.

Testosterone replacement therapy. What is its potential in elderly men?

Currently, the use of testosterone replacement therapy in elderly men is not considered routine. However, the aging population makes it an increasingly important issue for primary care physicians, and therapy can be effectively managed in a primary care setting when indicated. Because of testosterone's potential side effects, therapy should be customized and patients must be carefully monitored. This treatment has tremendous potential, but further research is needed before routinely recommending it for hypogonadal elderly men.

Congestive heart failure in elderly patients. The treatment goal is improved quality, not quantity, of life

Primary care physicians who see elderly patients are likely to see cases of congestive heart failure, since this condition is typically the result of long-standing hypertension or coronary artery disease. Recognizing the condition in elderly patients may not be easy, though, because clinical signs can be distorted by accompanying symptoms. In this article, the authors discuss pathophysiologic, diagnostic, and pharmacokinetic issues. They also describe therapy with diuretics, angiotensin-converting enzyme inhibitors, and digoxin and outline special considerations in the elderly.

Regulation of IFN-alpha/beta genes: evidence for a dual function of the transcription factor complex ISGF3 in the production and action of IFN-alpha/beta

BACKGROUND

Efficient production of interferons (IFNs) in virally infected cells is an essential aspect of the host defence. The transcription factor complex ISGF3 (IFN-stimulated gene factor 3) was originally identified as a critical mediator of the IFN signal; it is formed upon IFN receptor (IFNR) stimulation and binds to ISREs (IFN-stimulated response elements) to activate IFN-inducible genes. It has recently been shown that the DNA binding component of ISGF3, p48 (ISGF3gamma) also binds to virus-inducible elements in the IFN-alpha/beta genes, suggesting a potential new role of p48 in IFN production.

RESULTS

Primary cells from mice with a targeted disruption of the p48 gene show severe defects in virus-induced IFN-alpha/beta gene expression. A similar defect was also observed in cells lacking type I IFNR or Stat1, further demonstrating the role of IFN signalling in the induction of these IFN genes. ISGF3 in fact binds to the virus-inducible elements within the IFN-alpha/beta promoters. We also provide evidence showing that these elements are additionally controlled by an unidentified factor(s) which presumably triggers the primary phase of IFN gene induction.

CONCLUSIONS

Our results demonstrate that the IFN signal transducing complex ISGF3 plays a crucial role in IFN production and suggest that ISGF3 may participate directly in the activation of IFN-alpha/beta promoters. This dual function of ISGF3 may insure the efficient operation of this cytokine system in the host defence.

Identification of the lysyl oxidase gene as target of the antioncogenic transcription factor, IRF-1, and its possible role in tumor suppression

The transcriptional activator IFN regulatory factor 1 (IRF-1) and its antagonistic repressor IRF-2 are regulators of the IFN system. IRF-1 also manifests tumor suppressive activity, and its inactivation could contribute to the development of human hematopoietic malignancies. Here, we report the identification of the lysyl oxidase gene as a target gene of IRF-1. An IRF response element was identified in the lysyl oxidase gene promoter. We also demonstrate that the transformed phenotype of ras-expressing embryonic fibroblasts with a null mutation in the IRF-1 allele could be suppressed by the expression of the lysyl oxidase cDNA, implicating its potential role in tumor suppression. Thus, the regulation of the lysyl oxidase gene by IRF-1 could contribute to the multistep process of malignant transformation.

Essential and non-redundant roles of p48 (ISGF3 gamma) and IRF-1 in both type I and type II interferon responses, as revealed by gene targeting studies

BACKGROUND

Interferons (IFNs) are a class of cytokines which confer cellular resistance against viral infections. Type I (IFN-alpha and -beta) and type II (IFN-gamma) IFNs utilize distinct receptors, the stimulation of which results in the induction of downstream target genes. These target genes usually contain within their promoter region an IFN responsive element, termed ISRE (IFN stimulated response element) which binds a heterotrimeric transcription factor, ISGF3 (IFN-stimulated gene factor 3) consisting of p48 (ISGF3 gamma), Stat1 (Signal transducers and activators of transcription-1; alpha or beta), and Stat2. The ISRE sequence overlaps with that of IRF-E which binds another IFN-inducible factor, IRF-1 (IFN regulatory factor-1).

RESULTS

We generated mice lacking p48 by gene targeting. We show that p48 plays an essential role in both type I and type II IFN responses; activation of IFN-inducible genes and establishment of the antiviral state by IFN-alpha or -gamma are both severely impaired, and ISRE-binding activities induced by both IFNs are absent in the p48-negative embryonic fibroblasts (EFs). Furthermore, we generated mice deficient for both p48 and IRF-1 and found that at least one IFN-inducible gene is dependent on both factors.

CONCLUSIONS

p48 and IRF-1 do not perform redundant functions in the cell, but rather complement one another in both type I and II IFN responses.

The effect of low dose lofepramine in depressed elderly patients in general medical wards

A double-blind randomised controlled trial of the effect of low dose lofepramine (70 mg once daily) against placebo was carried out on depressed elderly inpatients on general medical wards for the elderly, comparing measures of depression and side-effects between the randomised groups. Patients were identified for the study using the Geriatric Depression Scale (GDS) and the Brief Assessment Schedule Depression Cards (BASDEC). Sixty-three subjects were randomised: 46 patients completed the entire trial of 28 days treatment. BASDEC and GDS were administered on day 8 post-admission, and depressed patients were randomised double-blind to either low dose lofepramine (70 mg daily) (n = 23) or placebo (n = 23). Assessment of changes in depressive states were made using the Montgomery Asberg Depression Rating Scale (MADRS) on days 8, 18 and 36 post-admission. Both groups improved by a similar amount during the trial. Lofepramine tended to be more effective than placebo in those patients who were more depressed (GDS > or = 18). On the other hand, subjects who were less depressed (i.e. GDS < 18) improved more on placebo than lofepramine. Low dose lofepramine may prove useful in moderately or severely depressed patients treated for only 4 weeks. However, low dose lofepramine is not indicated for mild (GDS 15-18) depression.

Clinical and histological features of 'mechanic's hands' in a patient with antibodies to Jo-1--a case report

The clinical and histological features of 'mechanic's hands' are described in a patient with polymyositis characterized serologically by antibodies to histidyl tRNA synthetase (Jo-1). Although described in the past in association with polymyositis, these distinctive cutaneous lesions have only recently been associated with the 'anti-synthetase syndrome'. It is becoming apparent that recognition of subsets within the spectrum of polymyositis/dermatomyositis characterized by certain clinical and serological features not only have prognostic significance, but also may provide insights into mechanisms of disease.

Oral presentation of lymphoma: case report of T-cell lymphoma masquerading as oral Crohn's disease, and review of the literature

A 15-year-old male with labial swelling, mouth ulcers and mucosal tags is reported. While the features were clinically consistent with oral Crohn's disease the patient proved to have a fatal T-cell lymphocytic lymphoma.

Molecular analysis of hypoxanthine phosphoribosyl transferase mutants induced by glycidyl 1-naphthyl ether in mouse spleen cells in vivo

Treatment of C57BL/6J mice with an epoxide, glycidyl 1-naphthyl ether (GNE), resulted in an average of a 3.4-fold increase in frequency of 6-thioguanine-resistant mutants of mouse spleen T-lymphocytes. In similar experiments with the epoxide trichloropropylene oxide, no increase in mutant frequency was found. To determine the kind and location of mutations in the coding region of the hypoxanthine phosphoribosyl transferase (HPRT) gene, 26 GNE-induced mutants and 17 spontaneous mutants were analyzed by direct sequencing of polymerase chain reaction amplified cDNA. Among the GNE-induced mutants, HPRT cDNA was present in 22, while that from 4 could not be detected. Among the spontaneous mutants, HPRT cDNA was present in 15 and absent in 2. Among GNE-induced mutants, base substitution in HPRT occurred in 15 of 22 mutants analyzed. Nine of 15 base substitutions involved TA base pairs, primarily TA-->CG transitions. Base substitutions were found throughout exons 3-7 but 46% of substitutions were located in exon 3 and one frameshift mutation involving a GC base pair in exon 3 was also observed. Among the spontaneous mutants, base substitutions of HPRT occurred in 7 of 15 mutants analyzed with 6 of 7 base substitutions involving a TA base pair and another 2 of the 15 mutants showed a 4 base pair deletion. The base substitution spectrum in GNE-induced mutants was different from that of the spontaneous mutants.

Chromatographic purification and characterization of EBV DNase from chemically induced lymphoid cells

Epstein-Barr virus-associated deoxyribonuclease (EBV-DNase) was purified to homogeneity, as determined by silver staining, sequential column chromatography, and FPLC from Raji and P3HR-1 cells treated with 12-O-tetradecanoyl-phorbol-13-acetate and sodium butyrate. This viral protein was immunogenic and elicited high neutralization titer sera in rabbits. By silver staining of SDS-PAGE, Western immunoblot, and radioimmunoprecipitation using NPC patient sera and both polyclonal and monoclonal antibodies, the EBV DNase was identified as a 58K protein. The potential presence of two EBV DNases was also discussed.

Papular lesions and cutaneous lupus erythematosus: a comparative clinical and histological study using monoclonal antibodies

Skin biopsies from 13 patients with papular lesions thought to be cutaneous lupus erythematosus were analyzed by light microscopy, direct immunofluorescence and immunohistochemically and compared to 22 biopsies from patients with discoid lupus, subacute cutaneous lupus erythematosus and acute cutaneous lesions of SLE. Papular lesions demonstrated fewer florid dermal and epidermal changes but a similar marked mononuclear cell infiltrate which in all groups was composed predominantly of T lymphocytes (68.4 +2- 11.2 SD) with the mean helper: suppressor (corrected Leu 3a:T8) ratio 1.73 +/- 0.60 SD. HLA-DR expression on keratinocytes was present in 20 patients, including 4 with papular lesions, and was strongly associated with liquefactive degeneration (chi 2, p less than 0.001), the hallmark of dermoepidermal junctional damage.

Association of Epstein-Barr virus early antigen diffuse component and virus-specified DNA polymerase activity

The role of Epstein-Barr virus (EBV) early antigen diffuse component (EA-D) and its relationship with EBV DNA polymerase in EBV genome-carrying cells are unclear, EBV-specified DNA polymerase was purified in a sequential manner from Raji cells treated with phorbol-12,13-dibutyrate and n-butyrate by phosphocellulose, DEAE-cellulose, double-stranded DNA-cellulose, and blue Sepharose column chromatography. Four polypeptides with molecular masses of 110,000, 100,000, 55,000, and 49,000 daltons were found to be associated with EBV-specified DNA polymerase activity. A monoclonal antibody which could neutralize the EBV DNA polymerase activity was prepared and found to recognize 55,000- and 49,000-dalton polypeptides. An EA-D monoclonal antibody, R3 (G. R. Pearson, V. Vorman, B. Chase, T. Sculley, M. Hummel, and E. Kieff, J. Virol. 47:183-201, 1983), was also able to recognize these same two polypeptides associated with EBV DNA polymerase activity. It was concluded that EBV EA-D polypeptides, as identified by R3 monoclonal antibody, are critical components of EBV DNA polymerase.

Induction of virus enzymes by phorbol esters and n-butyrate in Epstein-Barr virus genome-carrying Raji cells

Phorbol esters and n-butyrate (SB) together could induce Epstein-Barr virus (EBV) DNA polymerase and DNase activities in Raji cells (virus nonproducer). Neither 12-O-tetradecanoylphorbol-13-acetate (TPA) nor SB alone could induce these EBV enzyme activities, transcription of the EcoRI C-region or other EBV proteins in Raji cells. The enzyme induction caused by exposure of Raji cells to TPA-SB was the result of the synthesis of virus-specified RNA, and the increase of linear EBV DNA content in Raji cells caused by TPA alone was not sufficient for induction of EBV-enzyme activities. Temporal characteristics of the TPA-SB induction process, but not the phorbol 12,13-dibutyrate-SB induction process, in Raji cells were observed; a critical phase (10-24 h) postphorbol ester treatment in phorbol 12,13-dibutyrate-SB-treated Raji cells which was responsible for the synthesis of virus RNA and enzymes was found. Phospholipase C, which increases intracellular diacylglycerols (and subsequently activates protein kinase C) was able to partially substitute for TPA in the TPA-SB induction for EBV polymerase and DNase activities. Sphingosine, a protein kinase C inhibitor, partially prevented the induction of virus enzyme activities in Raji cells treated with phorbol 12,13-dibutyrate and SB. No apparent changes in the methylation state of EBV DNA (EcoRI C region) were observed when Raji cells were treated with SB and TPA, alone or in combination. These results suggest that induction of EBV polymerase and DNase activities by TPA-SB may involve protein kinase C activation and another factor triggered by SB which together increase transcription of EBV DNA.

Pagetoid reticulosis, epidermotropic mycosis fungoides and mycosis fungoides: a disease spectrum

Using a standard technique involving monoclonal antibodies against T-cell subsets, we have shown that almost all the infiltrating T-cells in the epidermis of a patient with Pagetoid reticulosis (PR), one with epidermotropic mycosis fungoides (EMF) and one with poikiloderma atrophicans vasculare (PAV), were OKT8 positive (presumed cytotoxic/suppressor) T-cells. The infiltrating T-cells in the epidermis of a patient with limited plaque stage mycosis fungoides (MF), however, were almost exclusively Leu 3a-positive (presumed helper/inducer) T-cells as is usually found in this condition. The keratinocytes in the patients with PR, EMF and PAV were HLA-DR-positive whilst those in the patient with MF were HLA-DR-negative. We consider these four diseases to be part of the spectrum of mycosis fungoides, the first three conditions representing the early or benign end of the spectrum.

Demonstration of Epstein-Barr virus-specific DNA polymerase in chemically induced Raji cells and its antibody in serum from patients with nasopharyngeal carcinoma

Epstein-Barr virus (EBV) has been found to be associated with nasopharyngeal carcinoma (NPC), and antibodies with high frequency and titer to EBV proteins have been found in sera from NPC patients. Raji cells, an EBV genome-carrying nonproducer cell line, treated with 12-O-tetradecanoylphorbol-13-acetate and n-butyrate induced a unique EBV DNA polymerase which has properties similar to the EBV DNA polymerase induced by 12-O-tetradecanoylphorbol-13-acetate in P3HR-1 cells, an EBV producer cell line. The possible presence of antibodies to this EBV DNA polymerase in NPC patient serum was examined. The mean number of EBV DNA polymerase units neutralized was 380 +/- 168 units/ml serum (mean +/- SD) in 48 sera from patients with NPC, whereas that in the sera from 52 healthy donors was 62 +/- 56 units/ml (p less than 0.01). The EBV DNA polymerase antibody was found to be associated with the immunoglobulin G but not the immunoglobulin A fraction, and its titer was not correlated with the titers against EBV DNase or virus capsid antigen-immunoglobulin A. Whether the EBV DNA polymerase antibody is against the EBV DNA polymerase core protein or its stimulating protein is still being investigated. This study demonstrated the high frequency and high titer of antibody against EBV DNA polymerase in serum from NPC patients and suggested the potential of utilizing this antibody titer to complement other methods for the early diagnosis or prognosis of NPC.