Cold Shock as a Screen for Genes Involved in Cold Acclimatization in .

When subjected to rapid drops of temperature (cold shock), responds with a temporary shift in its morphology. This report is the first to examine this response genetically. We report here the results of a screen of selected mutants from the knockout library for alterations in their morphological response to cold shock.

Architecture and development of the Neurospora crassa hypha -- a model cell for polarized growth.

Neurospora crassa has been at the forefront of biological research from the early days of biochemical genetics to current progress being made in understanding gene and genetic network function. Here, we discuss recent developments in analysis of the fundamental form of fungal growth, development and proliferation -- the hypha. Understanding the establishment and maintenance of polarity, hyphal elongation, septation, branching and differentiation are at the core of current research.

A screen for Neurospora knockout mutants displaying growth rate dependent branch density.

Branch density (the spatial distribution of branch initiation points along a growing hypha) in wild-type Neurospora has been shown to remain constant at different growth rates due to a hypothesized system which compensates for hyphal growth rate. Here we report the results of a survey of the Neurospora knockout library for mutants affecting this proposed growth rate compensation system. The mutants identified fail to maintain branching homeostasis at different growth rates, thus showing growth rate-dependent branch density.

Incident neuropathy in HIV-infected patients on HAART.

We determined the incidence of and risk factors for distal sensory polyneuropathy (DSP) in individuals on HAART. Sixty-one HIV-positive subjects on HAART for at least 6 months and neuropathy free were retrospectively selected. The study included subjects who had previously tolerated d-drugs without developing DSP.

Declined neural efficiency in cognitively stable human immunodeficiency virus patients.

Objective: To determine whether brain activation changes in clinically and neurocognitively normal human immunodeficiency virus (HIV)-infected and in HIV-seronegative control (SN) participants over a 1-year period.

Methods: Functional magnetic resonance imaging (fMRI) was performed in 32 SN and 31 HIV patients (all with stable combination antiretroviral treatment) at baseline and after 1 year. Each participant performed a set of visual attention tasks with increasing attentional load (from tracking two, three, or four balls).

Aging exacerbates extrapyramidal motor signs in the era of highly active antiretroviral therapy.

The phenotype of human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) in the developed world has changed with the broad institution of highly active antiretroviral therapy (HAART) and with aging of the HIV+ population. Extrapyramidal motor signs were a prominent feature of HAND as defined in the early stages of the epidemic but has not been reevaluated in the era of HAART. Moreover, the contribution of aging to extrapyramidal motor signs in the context of HIV remains undefined.

Greater than age-related changes in brain diffusion of HIV patients after 1 year.

Chronic infection with HIV is associated with neuroinflammation. Prior diffusion tensor imaging (DTI) studies demonstrated increased mean diffusion (MD) and decreased fractional anisotropy (FA) in the white matter (WM) and subcortical brain regions of HIV patients. The current study aims to detect whether there are greater than age-related brain changes in HIV patients after a 1-year follow-up period using DTI.

Neuropsychological test profile differences between young and old human immunodeficiency virus-positive individuals.

Human immunodeficiency virus (HIV) dementia remains as an important cause of neurological morbidity among HIV-seropositive (HIV+) individuals. Differences in the neuropsychological profiles between older and younger HIV+ individuals have not been examined extensively. The objective of this study was to examine the neuropsychological test performance between old and young HIV+ individuals (a) with and without cognitive impairment (total cohort) and (b) with dementia.

Solitary brain lesions enhancing at MR imaging: evaluation with fluorine 18 fluorocholine PET.

Purpose: To prospectively determine whether differences between benign and malignant brain lesions can be depicted with fluorine 18 ((18)F) fluorocholine positron emission tomography (PET).

Materials And Methods: Thirty consecutive patients (14 women, 16 men; age range, 26-79 years) with solitary brain lesions that were enhanced at magnetic resonance (MR) imaging underwent whole-brain (18)F-fluorocholine PET after giving informed consent in this institutional review board-approved, HIPAA-compliant study. Histopathologic diagnoses were made in 24 cases (13 high-grade gliomas, eight metastases to the brain, and three benign lesions).

HIV proviral DNA associated with decreased neuropsychological function.

The authors previously found a strong association between elevated HIV proviral DNA (HIV DNA) and a diagnosis of HIV-1-associated dementia (HAD) vs. normal cognition. It is unclear whether HIV DNA globally affects the diagnosis of HAD or whether the effect is limited to individual neuropsychological deficits.

Insulin resistance is associated with cognition among HIV-1-infected patients: the Hawaii Aging With HIV cohort.

Objective: To determine if insulin resistance (IR) is associated with lower cognitive performance among HIV-1-infected adults and to determine if advanced age magnifies risk.

Design: Cross-sectional analysis within the Hawaii Aging With HIV Cohort.

Methods: We calculated the homeostasis model assessment of insulin resistance (HOMA-IR) among 145 cohort participants.

Lowest ever CD4 lymphocyte count (CD4 nadir) as a predictor of current cognitive and neurological status in human immunodeficiency virus type 1 infection--The Hawaii Aging with HIV Cohort.

Low CD4 lymphocyte count was a marker for neurological disease in human immunodeficiency virus type 1 (HIV-1); but is now less common among patients with access to highly active antiretroviral therapy. In this study, the authors determine the reliability of self-reported CD4 nadir and its predictive value for neurological status. The authors identify a high degree of reliability (r = .

Tropical marine neurotoxins: venoms to drugs.

Neurotoxic venoms are common among tropical marine creatures, which have specialized apparatuses for delivery of the venoms. These include jellyfish and anemones, venomous cone snails, venomous fish, stingrays, sea snakes, and venomous octopuses. Numerous toxic neuropeptides are found within these venoms, and some can discriminate between closely related intracellular targets, a characteristic that makes them useful to define cation channels and attractive for drug development.

Circulating proviral HIV DNA and HIV-associated dementia.

Objective: Individuals continue to develop HIV-1-associated dementia (HAD) despite treatment with highly active antiretroviral therapy (HAART). Monocytes/macrophages (M/MPhi) can harbor proviral DNA that is not eradicated by HAART. To determine if HAD is associated with the level of HIV-1 infection within circulating leukocytes, we quantified HIV-1 DNA copy number in peripheral blood mononuclear cells (PBMC), and in PBMC subsets.

Diabetes, insulin resistance, and dementia among HIV-1-infected patients.

Objectives: Metabolic complications have been associated with HIV-1 infection and with long-term use of antiretroviral (ARV) medications. In some studies, such complications have been linked to cardiovascular events, yet limited data exist concerning metabolic complications and dementia. The objective of this study was to examine the relationship between HIV-associated dementia (HAD) and diabetes among patients with HIV-1 infection.

Cognitive impairment in older HIV-1-seropositive individuals: prevalence and potential mechanisms.

Individuals over 50 years of age comprise 11% of AIDS cases reported to the Centers for Disease Control and Prevention. A higher prevalence of AIDS in older individuals has been reported in certain states including Hawaii (20%) and Florida (13%). Although life expectancy in individuals with AIDS has increased with advances in antiretroviral therapy, it is likely that there are health consequences both of long-term infection and chronic antiretroviral therapy.

Marine Neurotoxins: Envenomations and Contact Toxins.

Familiarity with the appearance and habitat of venomous sea creatures, the location of their stinging apparatus, and surveillance of population concentrations within recreational waters are essential in avoiding envenomations. Compared with the thermo-stable low molecular weighted ingestible seafood toxins, venomous toxins are often large molecular weight proteins and many are heat labile, which provides opportunity for therapeutic intervention. Heat therapy may denature the toxins, and provide immediate relief of pain in coelenterate and venomous fish envenomations.

Marine Neurotoxins: Ingestible Toxins.

Fish and shellfish account for a significant portion of food-borne illnesses throughout the world. In general, three classes of diseases result from seafood consumption--intoxication, allergies, and infections. In this review, the authors discuss several seafood-borne toxins, including domoic acid, which acts on the central nervous system.

Calcific cerebral arterial embolization in the setting of bacterial endocarditis superimposed on prior rheumatic aortic valvular disease.

Stroke from a calcific cerebral artery embolus demonstrated by noncontrast computed tomography (CT) is rare. Although the ability of CT to demonstrate early acute cerebral emboli is limited, in the uncommon event of a calcific cerebral embolus, CT can easily visualize the embolized material. We present an unusual case of calcific cerebral arterial embolization to the proximal middle cerebral artery and illustrate the usefulness of CT in diagnosing this rare entity in conjunction with important predisposing clinical factors.