The structural components of the Azotobacter vinelandii iron-only nitrogenase, AnfDKG, form a protein complex within the plant mitochondrial matrix.

A long-held goal of synthetic biology has been the transfer of a bacterial nitrogen-fixation pathway into plants to reduce the use of chemical fertiliser on crops such as rice, wheat and maize. There are three classes of bacterial nitrogenase, named after their metal requirements, containing either a MoFe-, VFe- or FeFe-cofactor, that converts N2 gas to ammonia. Relative to the Mo-nitrogenase the Fe-nitrogenase is not as efficient for catalysis but has less complex genetic and metallocluster requirements, features that may be preferable for engineering into crops. Here we report the successful targeting of bacterial Fe-nitrogenase proteins, AnfD, AnfK, AnfG and AnfH, to plant mitochondria. When expressed as a single protein AnfD was mostly insoluble in plant mitochondria, but coexpression of AnfD with AnfK improved its solubility. Using affinity-based purification of mitochondrially expressed AnfK or AnfG we were able to demonstrate a strong interaction of AnfD with AnfK and a weaker interaction of AnfG with AnfDK. This work establishes that the structural components of the Fe-nitrogenase can be engineered into plant mitochondria and form a complex, which will be a requirement for function. This report outlines the first use of Fe-nitrogenase proteins within a plant as a preliminary step towards engineering an alternative nitrogenase into crops.

Internet connectivity among rural Alabama veterans: baseline findings from the Alabama Veterans Rural Health Initiative Project.

INTRODUCTION: The purpose of this secondary data analysis was to characterize the Internet usage of rural veterans (n=201) who had either never enrolled, or had previously enrolled but not accessed, Veterans Affairs (VA) health services in at least 2 years. The VA Office of Rural Health (ORH)(ie part of the United States Government Department of Veterans Affairs) is a government agency with the mission to improve access and quality of care for enrolled rural and highly rural US veterans. The ORH seeks to use evidence-based policies and innovative practices to support the unique needs of enrolled veterans residing in geographically remote areas. These individuals represent a population considered to experience health disparities secondary to reduced health care access. METHODS: This study explored the role of the Internet in providing health information and information regarding VA services to rural Caucasian and African American veterans in the southeastern USA. African Americans were significantly younger (50.32 years, SD=13.50, range 22-85 years) than Caucasian rural veterans (58.50 years, SD=13.82, range 21-85 years). RESULTS: A small majority of veterans (n=107; 53.23%) reported 'going on-line to use the Internet or World Wide Web, or to send and receive e-mail'. Among Internet users, multivariate logistic regression showed that neither age nor race/ethnicity predicted using the Internet to access health information or information regarding VA services. CONCLUSION: In comparison with population norms, rural veterans displayed lower usage of the Internet; however, there were few practical age differences between young, middle-aged and older rural veterans in use of the Internet for seeking health information. These results suggest a tremendous potential for online outreach efforts to rural veterans seeking health information and information regarding VA services and benefits. The US Federal Government's VA Office of Rural Health is investing in technology-based services and will need to disseminate information regarding the availability of these services to rural veterans.

A phase Ib study of vosaroxin, an anticancer quinolone derivative, in patients with relapsed or refractory acute leukemia.

This study of vosaroxin evaluated dose-limiting toxicity (DLT), maximum-tolerated dose (MTD), pharmacokinetics (PK), clinical activity and pharmacodynamics in relapsed/refractory leukemia. Dosing was weekly (days 1, 8 and 15) or twice weekly (days 1, 4, 8 and 11). Seventy-three treated patients had a median age of 65 years, 85% had acute myeloid leukemia and 78% had refractory disease. Weekly schedule: 42 patients received 18-90 mg/m(2); MTD was 72 mg/m(2). Twice-weekly schedule: 31 patients received 9-50 mg/m(2); MTD was 40 mg/m(2). DLT was stomatitis; primary non-hematologic toxicity was reversible gastrointestinal symptoms and febrile neutropenia. Thirty-day all-cause mortality was 11%. Five patients had complete or incomplete remissions; median duration was 3.1 months. A morphologic leukemia-free state (bone marrow blast reduction to <5%) occurred in 11 additional patients. Antileukemic activity was associated with total dose or weekly time above 1 µmol/l plasma vosaroxin concentration (P<0.05). Vosaroxin exposure was dose proportional over 9-90 mg/m(2). The average terminal half-life was ~25 h and clearance was non-renal. No induction or inhibition of vosaroxin metabolism was evident. Vosaroxin-induced DNA damage was detected as increased intracellular γH2AX. Vosaroxin had an acceptable safety profile, linear PK and encouraging clinical activity in relapsed/refractory leukemia.

Geriatric sleep apnea syndrome: a preliminary description.

We compared 8 patients diagnosed with geriatric sleep apnea syndrome (GSAS) with 12 healthy older controls (GCON) matched on age, sex, weight, education, and socioeconomic standing. GSAS was diagnosed if patients had an apnea + hypopnea index (AHI) greater than or equal to 10 and an impairment involving at least two of the following: hypertension, cardiac arrhythmias, or daytime hypersomnolence. In addition to significant differences on selection variables (e.g., AHI, frequency of hypertension, Multiple Sleep Latency Test), GSAS patients had significantly more sleep disturbance, were sleepier on subjective measures, were more depressed, and had lower scores on tests of nonverbal problem solving and nonverbal memory. Thus, GSAS resembles SAS described in middle-aged populations. More research is needed to determine the most efficient diagnostic parameters for identifying pathological levels of SDB in older persons.

Sleep-disordered breathing in healthy aged persons: one-year follow-up of daytime sequelae.

We studied the waking medical, sleep, and psychological status of 28 healthy older persons who had undergone nocturnal polysomnography and daytime assessment approximately 1-year earlier. In a previous report based on this sample, we found that sleep-disordered breathing (SDB) indices were not related to concurrent measurements of daytime functioning. However, in the present study, we observed relationships between the original SDB indices and several measures of cardiopulmonary functioning obtained 1 year later. At follow-up, subjects with originally high levels of SDB had significantly higher systolic blood pressure and poorer pulmonary function test results, were more likely to report irregular heartbeats in the previous year, and had experienced more disruptive snoring than the remaining subjects. When combined with other recent data, these results raise the possibility that SDB exerts an insidious pathological influence on the health and daytime functioning of otherwise healthy older persons.

Elevation of plasma neuropeptide Y levels in congestive heart failure.

PURPOSE: Our objectives were to assess whether plasma neuropeptide Y (NPY) levels are elevated in patients with congestive heart failure (CHF) and whether or not NPY levels can serve as a reliable indicator of sympathetic activity in CHF. PATIENTS AND METHODS: Plasma levels of the sympathetic neurotransmitters norepinephrine and epinephrine and of the sympathetic co-transmitter NPY were measured in 17 patients with CHF and 14 healthy control subjects at rest and after maximal exercise. RESULTS: Under resting conditions, plasma NPY and norepinephrine levels were elevated in patients with CHF compared with control subjects (551 +/- 48 pg/ml versus 311 +/- 22 pg/ml, p less than or equal to 0.001 for NPY, and 306 +/- 73 pg/ml versus 124 +/- 22 pg/ml, p less than or equal to 0.02 for norepinephrine). Plasma NPY correlated better with plasma norepinephrine than with epinephrine, indicating its origin from sympathetic nerve terminals. Acute stimulation of sympathetic activity by dynamic exercise increased plasma norepinephrine levels in control subjects and patients with CHF, but did not significantly alter the mean plasma NPY value in the latter group. CONCLUSION: NPY may play a role in the pathophysiology of CHF.

Pseudopseudotumor cerebri: meningeal carcinomatosis presenting as benign intracranial hypertension.

We have described a 63-year-old man, taking diethylstilbestrol for adenocarcinoma of the prostate, who had papilledema. Lumbar puncture revealed intracranial hypertension without pleiocytosis. CT scan was normal, consistent with the diagnosis of pseudotumor cerebri. At craniotomy for placement of a ventriculoperitoneal shunt, the dura was found to be infiltrated with adenocarcinoma. In patients with known malignancy and elevated intracranial pressure, lumbar puncture and CT scan alone are not enough to rule out meningeal carcinomatosis; repeated lumbar puncture or cervical cisternal puncture may be necessary to document malignant cytology.

Failure of T cells specific for strong histocompatibility antigens to cooperate with B cells for a humoral response.

Thymus-derived lymphocytes (T cells) selected for reactivity to strong histocompatibility antigens over a period of one to twelve months in vitro were tested for their ability to cooperate with bone marrow-derived lymphocytes (B cells) for a humoral response. If cultured with normal syngeneic or allogeneic spleen cells and sheep erythrocytes (SRBC) as immunogen, inhibition of the anti-SRBC response was observed. Similarly, in T cell-free spleen cells the alloreactive T cells did not stimulate a humoral response, indicating that they cannot exert cooperative activity on B cells. Since it was possible that the alloreactive T cells may cooperate with B cells in a humoral response to immunogens carrying histocompatibility antigens, hapten-coupled tumor cells were also used as immunogen. Though it is demonstrated that the alloreactive T cells do recognize the tumor cell immunogen, no stimulation of the B cells for a humoral response against the tumor cell is observed. This result, as well as the finding that the antigenic requirements for T helper cell priming and cell proliferation of the alloreactive T cells are different, suggests that these alloreactive T cells and helper T cells belong to different T cell subsets.