Quantitative and qualitative sex difference in habenula-induced inhibition of midbrain dopamine neurons in the rat.

Introduction: Clinically relevant sex differences have been noted in a number of affective, behavioral, cognitive, and neurological health disorders. Midbrain dopamine neurons are implicated in several of these same disorders and consequently are under investigation for their potential role in the manifestation of these sex differences. The lateral habenula exerts significant inhibitory control over dopamine neuronal firing, yet little is known about sex differences in this particular neurocircuit. Methods: We performed in vivo, single unit, extracellular recordings of dopamine neurons in female and male anesthetized rats in response to single pulse stimulation of the lateral habenula. In addition, we assessed baseline firing properties of lateral habenula neurons and, by immunochemical means, assessed the distribution of estrogen receptor alpha cells in the lateral habenula. Results: Habenula-induced inhibition of dopamine neuronal firing is reduced in female rats relative to male rats. In addition, male rats had a higher prevalence of rebound excitation. Furthermore, the firing pattern of lateral habenula neurons was less variable in female rats, and female rats had a higher density of estrogen receptor alpha positive cells in the lateral habenula. Discussion: We found that the dopamine neuronal response to habenular stimulation is both qualitatively and quantitatively different in female and male rats. These novel findings together with reports in the contemporary literature lead us to posit that the sex difference in dopamine inhibition seen here relate to differential firing properties of lateral habenula neurons resulting from the presence of sex hormones. Further work is needed to test this hypothesis, which may have implications for understanding the etiology of several mental health disorders including depression, schizophrenia, and addiction.

Self-monitoring diabetes with multiple mobile health devices.

OBJECTIVE: The purpose of this study was to examine the use of multiple mobile health technologies to generate and transmit data from diverse patients with type 2 diabetes mellitus (T2DM) in between clinic visits. We examined the data to identify patterns that describe characteristics of patients for clinical insights. METHODS: We enrolled 60 adults with T2DM from a US healthcare system to participate in a 6-month longitudinal feasibility trial. Patient weight, physical activity, and blood glucose were self-monitored via devices provided at baseline. Patients also responded to biweekly medication adherence text message surveys. Data were aggregated in near real-time. Measures of feasibility assessing total engagement in device submissions and survey completion over the 6 months of observation were calculated. RESULTS: It was feasible for participants from different socioeconomic, educational, and racial backgrounds to use and track relevant diabetes-related data from multiple mobile health devices for at least 6 months. Both the transmission and engagement of the data revealed notable patterns and varied by patient characteristics. DISCUSSION: Using multiple mobile health tools allowed us to derive clinical insights from diverse patients with diabetes. The ubiquitous adoption of smartphones across racial, educational, and socioeconomic populations and the integration of data from mobile health devices into electronic health records present an opportunity to develop new models of care delivery for patients with T2DM that may promote equity as well.

Immunological responses and evaluation of the protection in dairy cows vaccinated with staphylococcal surface proteins.

Bovine mastitis is a significant cause of economic losses in the dairy industry. Staphylococcus aureus is one of the most common contagious mastitis pathogens, whereas Staphylococcus chromogenes increasingly became a significant cause of subclinical mastitis in dairy cows. Current mastitis control measures are not effective on all mastitis pathogens. There is no effective vaccine to control Staphylococcal mastitis in dairy cows. The objective of this study was to evaluate the immune responses and protection in dairy cows vaccinated with S. aureus surface proteins (SASP) or S. chromogenes surface proteins (SCSP). We divided eighteen Holstein dairy cows randomly into three groups of 6 animals each. We vaccinated group 1 and 2 animals with SASP and SCSP with Emulsigen-D adjuvant, respectively. We injected control (group 3) animals with PBS (pH 7.2) in Emulsigen®-D. We vaccinated animals three times at 28 and 14 days before drying off, and at dry off. Two weeks after the third vaccination, we challenged each animal by dipping all teats in S. aureus culture suspension once daily for 14 consecutive days. We evaluated milk or mammary secretion and serum antibody titers during vaccination and challenge periods. We evaluated milk samples for the number of bacteria shedding and somatic cell counts (SCC). Out of six cows vaccinated with SASP, one cow was removed from the study due to injury, two were infected clinically, another two were infected subclinically, and the remaining cow was not infected. No SCSP vaccinated cows developed clinical or subclinical mastitis. Out of six control cows, two developed clinical mastitis whereas four were infected subclinically. The SCSP vaccine cross-protected against S. aureus mastitis and reduced number of S. aureus shedding in milk. We concluded that the SCSP is a promising vaccine to control Staphylococcal mastitis in dairy cows.

Readability, content, quality and accuracy assessment of internet-based patient education materials relating to labor analgesia.

BACKGROUND: With over 90% of parturients searching the internet for health information, the quality of information is important. Web-based patient education materials (PEMs) related to labor analgesia are frequently of low readability. This study compares the readability, content, quality and accuracy of labor analgesia-related PEMs from relevant healthcare society websites and the top internet search results. METHODS: The first ten PEMs from Google searches for "labor epidural" and "labor pain relief" were compared with PEMs from North American and United Kingdom anesthesiology, obstetric and medical society websites. Readability was assessed utilizing five validated readability indices. Quality was assessed using Patient Education Materials Assessment Tool for Print (PEMAT). The PEMs were graded for accuracy by four obstetric anesthesiologists. Readability, quality and accuracy scores were compared using the independent t-test and content using Chi-square analysis. RESULTS: Society PEMs were significantly more readable than non-society PEMs for three of five readability indices, though the mean of both groups was at or above an eighth-grade (average age 13-14 years-old) reading level. The PEMAT understandability and accuracy scores were significantly higher for society websites. The most frequently mentioned topics were benefits, effects of epidural analgesia on labor and delivery, definitions, post-dural puncture headache and alternative analgesics. CONCLUSIONS: Google search results for labor analgesia lead to PEMs of variable quality and readability. For readers to be better informed, web-based PEMs should be improved or women directed to society PEMs. Inaccurate information may lead to incorrect expectations and conflict during labor, with potentially lower maternal satisfaction.

Telehealth and telenursing using simulation for pre-licensure USA students.

An innovative simulation was used to teach pre-licensure USA nursing students about telenursing for screening, assessment, and patient education during a home visit. The students used telepresence technology to deliver nursing care to a homebound geriatric patient. After the simulation, students (N = 73) felt increased confidence with the skills needed to deliver telenursing care and in using telepresence technology. Students reported that they modified and improved their communication in order to adapt to perceived barriers posed by the new technology. As telenursing becomes more prevalent for managing patient care at a distance, nursing programs will need to incorporate educational strategies to reflect this change.

Treatment of refractory ITP and Evans syndrome by haematopoietic cell transplantation: is it indicated, and for whom?

Several lines of therapy have been established for patients with immune thrombocytopenia (ITP) and Evans syndrome. However, these therapies generally require prolonged administration, lead to profound immunosuppression and increased infectious risk, and are often poorly tolerated. While most patients with these disorders will respond to first-line steroid therapy, others will prove refractory or intolerant to multiple treatments. In these patients (and possibly even selected patients who are not considered refractory), autologous or allogeneic haematopoietic stem cell transplantation (HCT) may provide definitive therapy. We review the literature on the treatment of ITP and Evans syndrome with HCT and discuss its use in the management of these disorders. We also pose, for the purpose of discussion, research questions that will be important to address if HCT is to be considered a viable option for more patients with these diseases.

MRI characterization and longitudinal study of focal cerebellar lesions in a young tuberous sclerosis cohort.

BACKGROUND AND PURPOSE: There are few articles characterizing cerebellar lesions in patients with TSC and no published series documenting longitudinal evaluation of these lesions, to our knowledge. Recent suggestion of a correlation between autism and cerebellar lesions in patients with TSC heightens the importance of understanding these lesions. Our purpose was to characterize cerebellar lesions in a cohort of young patients with TSC with specific interest in assessing longitudinal changes. MATERIALS AND METHODS: We retrospectively reviewed MR images from 145 pediatric and young adult patients with tuberous sclerosis (mean age, 7.6 years). A number of imaging characteristics of cerebellar tubers were recorded, and patients were evaluated for SGAs. Patients with follow-up scans >3 months from the original scan were further analyzed for longitudinal tuber characterization. RESULTS: There were 24.1% of patients with focal cerebellar lesions; 52.4% of patients with cerebellar lesions demonstrated change in imaging characteristics during longitudinal analysis. Fifty-one percent of the lesions were enhanced after gadolinium administration. Twenty percent of the patients with cerebellar lesions had pathologically confirmed SGAs compared with the incidence of 11% in the 145 patients with TSC reviewed. CONCLUSIONS: In our large cohort of young patients with TSC, cerebellar tubers were common and 52% of patients had tubers that changed with time. A higher percentage of patients with cerebellar lesions developed SGAs than patients with TSC without cerebellar lesions. Because this is the first reported longitudinal study of cerebellar lesions in TSC, further investigation may provide additional insight into TSC pathology and associated clinical manifestations, such as autism, developmental delay, and seizures.

Impact of gradient timing error on the tissue sodium concentration bioscale measured using flexible twisted projection imaging.

The rapid biexponential transverse relaxation of the sodium MR signal from brain tissue requires efficient k-space sampling for quantitative imaging in a time that is acceptable for human subjects. The flexible twisted projection imaging (flexTPI) sequence has been shown to be suitable for quantitative sodium imaging with an ultra-short echo time to minimize signal loss. The fidelity of the k-space center location is affected by the readout gradient timing errors on the three physical axes, which is known to cause image distortion for projection-based acquisitions. This study investigated the impact of these timing errors on the voxel-wise accuracy of the tissue sodium concentration (TSC) bioscale measured with the flexTPI sequence. Our simulations show greater than 20% spatially varying quantification errors when the gradient timing errors are larger than 10 µs on all three axes. The quantification is more tolerant of gradient timing errors on the Z-axis. An existing method was used to measure the gradient timing errors with <1 µs error. The gradient timing error measurement is shown to be RF coil dependent, and timing error differences of up to ∼16 µs have been observed between different RF coils used on the same scanner. The measured timing errors can be corrected prospectively or retrospectively to obtain accurate TSC values.

Atom-by-atom extraction using the scanning tunneling microscope tip-cluster interaction.

We investigate the atomistic details of a single atom-extraction process realized by using the scanning tunneling microscope tip-cluster interaction on a Ag(111) surface at 6 K. Single atoms are extracted from a silver cluster one atom at a time using small tunneling biases less than 35 mV. Combined total energy calculations and molecular dynamics simulations show a lowering of the atom-extraction barrier upon approaching the tip to the cluster. Thus, a mere tuning of the proximity between the tip and the cluster governs the extraction process. The atomic precision and reproducibility of this procedure are demonstrated by repeatedly extracting single atoms from a silver cluster on an atom-by-atom basis.

The effects of deafferentation and exogenous NGF on neurotrophins and neurotrophin receptor mRNA expression in the adult superior cervical ganglion.

Levels of nerve growth factor (NGF) and neurotrophin-3 (NT-3) protein and neurotrophin receptor mRNA in adult sympathetic neurons were investigated following surgical removal of preganglionic input and/or in vivo administration of NGF. Expression of trkC and p75, but not trkA, was significantly decreased following a 3-week deafferentation of the superior cervical ganglion (SCG). Protein levels of NGF and NT-3 in the SCG were unchanged by deafferentation. A 2-week intracerebroventricular infusion of NGF without deafferentation resulted in enhanced mRNA levels of trkA, trkC, and p75 as well as significantly increased NGF and NT-3 protein in the SCG. When NGF infusion followed deafferentation, both trkA and p75 showed significant increases while trkC levels were similar to control values. NGF protein was not increased in the SCG when deafferentation preceded exogenous NGF, yet NT-3 was elevated and levels were similar to cases receiving NGF infusion only. These results support a role for preganglionic input in trkC and p75 expression in adult sympathetic neurons. The increased levels of NT-3 protein and trkC gene expression observed following NGF infusion suggest that NGF influences NT-3 regulation in adult sympathetic neurons. In addition, the present findings provide evidence that, when preganglionic input is removed prior to the NGF infusion, NT-3 effectively competes with NGF for trkA binding. Taken together, we propose that NT-3 may play a role in the robust sprouting of sympathetic cerebrovascular axons previously observed following NGF administration, particularly when deafferentation precedes the NGF infusion period.

Measurement of finite-strain dependent permeability of biomembranes.

A complete understanding of fluid exchanges in tissues and organs requires knowledge of the permeability of their delimiting membranes as a function of the finite strain that they experience. One reason for the current dearth of data in the literature is the need for new theoretically motivated experimental approaches. In this paper, we use a general scaling to identify non-dimensional parameters that are measured easily by combining a simple pressure-driven diffusion chamber with a method to induce equibiaxial and homogeneous finite strains that can be measured via a non-contacting video system. Illustrative results on excised bovine epicardium reveal a nonlinear relationship between a non-dimensional permeability and finite strain up to stretches of 60%.

Development of cholinergic terminals around rat spinal motor neurons and their potential relationship to developmental cell death.

Neuron death seems to be regulated mainly by postsynaptic target cells. In chicks, nicotinic antagonists such as alpha-bungarotoxin (alphaBT) can prevent normal cell death of somatic motor neurons (SMNs). For this effect, however, alphaBT could be acting at peripheral neuromuscular junctions and/or central cholinergic synapses. To investigate this issue, we first studied the development of cholinergic terminals in the rat spinal cord by using vesicular acetylcholine transporter immunocytochemistry. Labeled terminals were seen in the ventral horn as early as embryonic day 15 (E15), the beginning of the cell death period. Thus, central cholinergic synapses form at the correct time and place to be able to influence SMN death. We next added alphaBT to organotypic, spinal slice cultures made at E15. After 5 days in vitro, the number of SMNs in treated cultures was substantially greater than in control cultures, indicating that alphaBT can reduce SMN cell death in rats as it does in chicks. Moreover, peripheral target removal led to extensive loss of SMNs, and such a loss occurred even in the presence of alphaBT, indicating the necessity of peripheral target for the alphaBT effect. Finally, to determine whether central cholinergic terminals also may be involved in SMN death, we delayed the alphaBT treatment until after central cholinergic terminals had disappeared from the slice cultures. The increased number of surviving SMNs, even in the absence of central terminals, argued that alphaBT acts at peripheral, not central, cholinergic synapses to rescue SMNs from developmental cell death.

The DNA-binding domain in the Bacillus subtilis transition-state regulator AbrB employs significant motion for promiscuous DNA recognition.

AbrB is a Bacillus subtilis protein responsible for regulating a diverse array of unrelated genes during periods of sub-optimal growth conditions. DNA binding by AbrB is unique in that sequence recognition is specific, yet no obvious consensus sequence of bound promoter regions is apparent. The N-terminal domain is a recently characterized representative of a novel class of DNA-binding proteins that possess a looped-hinge helix DNA-binding topology. Although the structural characterization of this DNA-binding topology contributed to an understanding of the architectural basis for recognition of DNA target sequences, specific mechanisms responsible for promiscuity in DNA sequence recognition still were not apparent. Analysis of (15)N backbone relaxation parameters shows that dynamic motion of regions directly linked to DNA binding show concerted motion on the microsecond-millisecond timescale. Furthermore, dynamic motion of the hinge region suggests that the DNA-binding region is capable of conformational orientations that allow it to accommodate DNA sequence variability in the cognate binding sites.

DNA strand breaks and cell cycle perturbation in herceptin treated breast cancer cell lines.

BACKGROUND: Herceptin is a humanized antibody that binds to the product of the HER-2 oncogene. Clinical studies have indicated that treatment with Herceptin may slow disease progression in tumors expressing high levels of the HER-2 antigen. However, the mechanism of this action is not known. METHODS: Four different cell lines were used that had different levels of HER-2 expression. Treated and nontreated cells were analyzed for DNA strand breaks and cell cycle perturbation using standard flow cytometry methods. RESULTS: In this study we found that cell lines expressing high levels of HER-2, when treated with Herceptin, exhibited marked increases in DNA strand breaks as measured by the TUNEL assay, and that these cells also exhibited slowed growth. BT-474 and SKBR-3 cell lines, both of which express high levels of the HER-2 antigen, had significant increases in labeled nucleotide expression at 3 and 6 day time points following exposure to Herceptin at a concentration of 10 microg/ml. Similar treatment of MCF-7 and MDA-231 cell lines, both of which express low levels of HER-2, had little effect on the level of labeled nucleotide expression at either the 3 or 6 day time points. Following 4 days of Herceptin treatment, BT-474 and SKBR-3 cell lines had significant decreases in the percentage of cells in the S phase of growth. This effect was not seen in either the MCF-7 or MDA-231 cell lines. CONCLUSION: Herceptin has a biological effect only on cells that contain high levels of HER-2. This effect is a decrease in cell proliferation that is coincident with, and may be caused by an increase frequency of DNA strand breaks.

Novel DNA binding domain and genetic regulation model of Bacillus subtilis transition state regulator abrB.

We have determined the high resolution NMR solution structure of the novel DNA binding domain of the Bacillus subtilis transition state regulator AbrB. Comparisons of the AbrB DNA binding domain with DNA binding proteins of known structure show that it is a member of a completely novel class of DNA recognition folds that employs a dimeric topology for cellular function. This new DNA binding conformation is referred to as the looped-hinge helix fold. Sequence homology investigations show that this DNA binding topology is found in other disparately related microbes. Structural analysis of the AbrB DNA binding domain together with bioanalytical and mutagenic data of full length AbrB allows us to construct a general model that describes the genetic regulation properties of AbrB.

Metabolites from apoptotic thymocytes inhibit thymopoiesis in adenosine deaminase-deficient fetal thymic organ cultures.

Murine fetal thymic organ culture was used to investigate the mechanism by which adenosine deaminase (ADA) deficiency causes T-cell immunodeficiency. C57BL/6 fetal thymuses treated with the specific ADA inhibitor 2'-deoxycoformycin exhibited features of the human disease, including accumulation of dATP and inhibition of S-adenosylhomocysteine hydrolase enzyme activity. Although T-cell receptor (TCR) Vbeta gene rearrangements and pre-TCR-alpha expression were normal in ADA-deficient cultures, the production of alphabeta TCR(+) thymocytes was inhibited by 95%, and differentiation was blocked beginning at the time of beta selection. In contrast, the production of gammadelta TCR(+) thymocytes was unaffected. Similar results were obtained using fetal thymuses from ADA gene-targeted mice. Differentiation and proliferation were preserved by the introduction of a bcl-2 transgene or disruption of the gene encoding apoptotic protease activating factor-1. The pan-caspase inhibitor carbobenzoxy-Val-Ala-Asp-fluoromethyl ketone also significantly lessened the effects of ADA deficiency and prevented the accumulation of dATP. Thus, ADA substrates accumulate and disrupt thymocyte development in ADA deficiency. These substrates derive from thymocytes that undergo apoptosis as a consequence of failing to pass developmental checkpoints, such as beta selection.

beta-adrenergic receptor population is up-regulated by increased cyclic adenosine monophosphate concentration in chicken skeletal muscle cells in culture.

Skeletal muscle hypertrophy is promoted in vivo by administration of beta-adrenergic receptor (betaAR) agonists. Chicken skeletal muscle cells were treated with 1 microM isoproterenol, a strong betaAR agonist, between days 7 and 10 in culture. betaAR population increased by approximately 40% during this treatment; however, the ability of the cells to synthesize cyclic adenosine monophosphate (cAMP) was diminished by twofold. Neither the basal concentration of cAMP nor the quantity of myosin heavy chain (MHC) was affected by the 3-d exposure to isoproterenol. To understand further the relationship between intracellular cAMP levels, betaAR population, and muscle protein accumulation, intracellular cAMP levels were artificially elevated by treatment with 0-10 betaM forskolin for 3 d. The basal concentration of cAMP in forskolin-treated cells increased up to sevenfold in a dose-dependent manner. Increasing concentrations of forskolin also led to an increase in betaAR population, with a maximum increase of approximately 40-60% at 10 microM forskolin. A maximum increase of 40-50% in the quantity of MHC was observed at 0.2 microM forskolin, but higher concentrations of forskolin reduced the quantity of MHC back to control levels. At 0.2 microM forskolin, intracellular levels of cAMP were higher by approximately 35%, and the betaAR population was higher by approximately 30%. Neither the number of muscle nuclei fused into myotubes nor the percentage of nuclei in myotubes was affected by forskolin at any of the concentrations studied.

Genomic structure and expression of human KCNJ9 (Kir3.3/GIRK3).

The human KCNJ9 (Kir 3.3, GIRK3) is a member of the G-protein-activated inwardly rectifying potassium (GIRK) channel family. Here we describe the genomic organization of the KCNJ9 locus on chromosome 1q21-23 as a candidate gene for Type II diabetes mellitus in the Pima Indian population. The gene spans approximately 7.6 kb and contains one noncoding and two coding exons separated by approximately 2.2 and approximately 2.6 kb introns, respectively. We identified 14 single nucleotide polymorphisms (SNPs), including one that predicts a Val366Ala substitution, and an 8 base-pair (bp) insertion/deletion. Our expression studies revealed the presence of the transcript in various human tissues including pancreas, and two major insulin-responsive tissues: fat and skeletal muscle. The characterization of the KCNJ9 gene should facilitate further studies on the function of the KCNJ9 protein and allow evaluation of the potential role of the locus in Type II diabetes.