Degenerative cervical myelopathy delays responses to lateral balance perturbations regardless of predictability.

The aim of this study was to quantify balance impairments in standing in people with degenerative cervical myelopathy (PwDCM) in response to external perturbations. PwDCM have damage to their spinal cord due to degeneration of the cervical vertebral column, but little is known about balance. Balance was quantified by capturing kinetics, kinematic, and electromyographic data during standing in response to lateral waist pulls. Participants received pulls during predictable and unpredictable contexts in three stance widths at two magnitudes. In response to lateral waist pulls, PwDCM had larger center of mass excursion (P < 0.001) and delayed gluteus medius electromyography onset (P < 0.001) and peak (P < 0.001) timing. These main effects of history of myelopathy were consistent across predictability, stance width, and magnitude. A multilinear regression determined that gluteus medius peak timing + tibialis anterior peak timing most strongly predicted center of mass excursion (R2 = 0.50, P < 0.001). These data suggest that PwDCM have delays in generating voluntary and reactive motor commands, contributing to balance impairments. Future rehabilitation strategies should focus on generating rapid muscular contractions. Additionally, frontal plane postural control is regulated by the gluteus medius and the tibialis anterior, whereas other muscles (e.g. gluteus minimus, ankle invertors/evertors) not studied here may also contribute.NEW & NOTEWORTHY Frontal plane reactive postural control is impaired in persons with degenerative cervical myelopathy because of delayed muscle responses. Additionally, postural control varies across stance width, predictability, and perturbation magnitude.

Silk Film Stiffness Modulates Corneal Epithelial Cell Mechanosignaling.

Silk fibroin films are excellent candidate biomaterials for corneal tissue engineering due to their optical transparency, biocompatibility, and mechanical strength. Their tunable chemical and mechanical properties open the possibility of engineering cellular microenvironments that can both mimic native corneal tissue and provide stimuli to actively promote wound regeneration. While silk film mechanical properties, such as surface topography, have demonstrated the ability to control corneal epithelial cell wound regenerating behavior, few studies have explored the stiffness tunability of these films and its cellular effects. Cells are known actively sense the stiffness of their surroundings and processes such as cell adhesion, migration, proliferation, and expression of stem markers can be strongly influenced by matrix stiffness. This study develops technical solutions that allow for both the fabrication of films with stiffnesses similar to corneal tissue and also for their characterization in an aqueous, native-like environment at a scale relevant to cellular forces. Physiological evidence demonstrates that corneal epithelial cells are mechanosensitive to films of different stiffnesses and show that cell spreading, cytoskeletal tension, and molecular mechanotransducer localization are associated with film stiffness. These results indicate that silk film stiffness can be used to regulate cell behavior for the purposes of ocular surface repair.

HIV and HCV health beliefs in an inner-city community.

Chronic infection with the hepatitis C virus (HCV) is more prevalent than human immunodeficiency virus (HIV) infection, but more public health resources are allocated to HIV than to HCV. Given shared risk factors and epidemiology, we compared accuracy of health beliefs about HIV and HCV in an at-risk community. Between 2002 and 2003, we surveyed a random patient sample at a primary care clinic in New York. The survey was organized as domains of Common Sense Model of Self-Regulation: causes ('sharing needles'), timeline/consequences ('remains in body for life', 'causes cancer') and controllability ('I can avoid this illness', 'medications may cure this illness'). We compared differences in accuracy of beliefs about HIV and HCV and used multivariable linear regression to identify factors associated with relative accuracy of beliefs. One hundred and twenty-two subjects completed the survey (response rate 42%). Mean overall health belief accuracy was 12/15 questions (80%) for HIV vs 9/15 (60%) for HCV (P < 0.001). Belief accuracy was significantly different across all domains. Within the causes domain, 60% accurately believed sharing needles a risk factor for HCV compared to 92% for HIV (P < 0.001). Within the timeline/consequences domain, 42% accurately believed HCV results in lifelong infection compared to 89% for HIV (P < 0.001). Within the controllability domain, 25% accurately believed that there is a potential cure for HCV. Multivariable linear regression revealed female gender as significantly associated with greater health belief accuracy for HIV. Thus, study participants had significantly less accurate health beliefs about HCV than about HIV. Targeting inaccuracies might improve public health interventions to foster healthier behaviours and better hepatitis C outcomes.

Atypical depression among psychiatric inpatients: clinical features and personality traits.

OBJECTIVE: This study investigates the frequency and characteristics of Atypical Depression (AD) among depressed inpatients. METHOD: Twenty-one depressed inpatients received DSM-IV diagnoses, were rated on the Hamilton Depression Rating Scale (HAMD), and assessed for AD using the Atypical Depressive Disorder Scale. AD was defined as the presence of mood reactivity and two of four associated features: hyperphagia, hypersomnia, leaden paralysis, rejection sensitivity. Mood reactivity was defined as the ability to reach 50% of a non-depressed mood. All subjects completed the SCL-90, MCMI-II, and a suicide survey. RESULTS: Seven patients (33%) met criteria for AD. AD and non-AD patients did not differ in terms of severity of depression, history of suicide attempts, levels of clinical symptomatology, age of onset of depression, prior hospitalizations, and most personality characteristics. However, AD patients scored significantly higher than non-AD patients on the SCL-90 Interpersonal Sensitivity and MCMI-II Avoidant scales, and were more likely to be single. CONCLUSION: AD is fairly prevalent on an inpatient service, comparable to the frequency found in outpatient settings. AD is not a milder form of depression. The only differences between AD and non-AD patients reflect the personality trait of rejection sensitivity which is a defining feature of AD.

Biological and clinical validation of atypical depression.

Depressed patients with (a) mood reactivity alone (MR group), (b) mood reactivity plus one or more associated features (atypical depression, AD group), and (c) patients with neither mood reactivity nor atypical depression (non-MR/AD group) were compared on their cortisol response to 75 mg of desipramine (DMI), a relatively selective norepinephrine reuptake inhibitor. AD patients exhibited a significantly higher cortisol response to DMI compared with MR and non-MR/AD patients, suggesting that atypical depression may be associated with a less impaired norepinephrine system. MR and non-MR/AD patients did not differ, suggesting that mood reactivity alone is not associated with the biological profile observed in atypical depression. Results indicate that while mood reactivity may be necessary for the diagnosis of atypical depression, the additional presence of at least one associated symptom is required for a distinct biological profile. Our findings provide further biological validation of the concept of atypical depression.

Atypical depression: clinical aspects and noradrenergic function.

OBJECTIVE: The authors assessed the frequency of atypical depression in depressed outpatients and compared clinical and biological features of patients with atypical and nonatypical depression. METHOD: Depressed outpatients (N = 114) were diagnosed with the Schedule for Affective Disorders and Schizophrenia (SADS) according to Research Diagnostic Criteria. Patients were assessed for presence or absence of atypical depression with the Atypical Depressive Disorder Scale. Atypical depression was defined as the presence of mood reactivity during the depressive episode, along with at least one of four associated features: hypersomnia, hyperphagia, leaden paralysis, and rejection sensitivity. All patients completed the SCL-90 and were rated with the Hamilton Depression Rating Scale, extracted from the SADS. To assess biological functioning, the authors examined cortisol response to 75 mg of desipramine, a relatively selective norepinephrine reuptake inhibitor. RESULTS: Twenty-nine percent of patients met criteria for atypical depression. Patients with atypical depression were significantly more likely to be female. Patients with atypical and nonatypical depression did not differ on SCL-90 subscale scores. Although extracted Hamilton depression scale scores were significantly higher for patients with nonatypical depression, the difference was not clinically significant. Patients with atypical depression exhibited a significantly different cortisol response to desipramine injection than patients with nonatypical depression, which suggested that nonatypical depression may be associated with a more impaired norepinephrine system. CONCLUSIONS: In view of data in this study, as well as earlier studies, atypical depression has a unique symptom profile, may be widely prevalent, has a distinct treatment response, and may indicate a less impaired biological system than nonatypical depression. Since this is the first report to evaluate the frequency of atypical depression as well as the norepinephrine system in atypical depression, this study needs to be replicated. Nonetheless, the data support the inclusion of atypical depression as a subtype of the depressive disorders in DSM-IV.