Neuronal correlates of spider phobia in a combined fNIRS-EEG study

Specific phobia is associated with aberrant brain activation in confrontation paradigms with phobic stimuli. In previous EEG research enhanced event-related potentials (ERPs) in the late-positive potential (LPP) window have been observed. Further, studies with functional near-infrared spectroscopy (fNIRS) and fMRI suggest that spider phobia is associated with enhanced activation within cortical and subcortical areas. In the current study we investigated the neuronal correlates of spider phobia in a combined fNIRS-EEG study. To this end, 37 spider phobic patients (PP) and 32 healthy controls (HC) underwent a symptom provocation paradigm during which subjects watched video clips of spiders and domestic animals (confrontation phase) after being primed on the content of the video (anticipation phase). Simultaneously, fNIRS, EEG, electromyography (EMG), electrocardiography and behavioral measures were assessed. Results showed increased LPP amplitudes, increased hemodynamic responses in the cognitive control network, and increased EMG activity and heart rate during spider conditions in PP in comparison to HC. Furthermore, in behavioral ratings PP showed higher emotional distress and avoidance. Behavioral ratings, fNIRS and EEG data showed positive correlations on a between-subject as well as on a within-subject level. Our results merge the existing data on neurophysiological correlates of phobic stimulus processing in hemodynamic and electrophysiological research and extend those of static visual material (pictures) to dynamic visual material (videos).

Cortical oxygenation during exposure therapy - in situ fNIRS measurements in arachnophobia

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This is the first study that assessed cortical hemodynamic reactions during exposure therapy in situ.

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During exposure patients showed increased activity in the cognitive control network (CCN) compared to a control condition.

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CCN activity deceased during the session.

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Further, CCN activity was associated with fear ratings at the beginning of the session and this relationship decreased from session to session.

Exposure therapy is a well-studied and highly efficacious treatment for phobic disorders. Although the neurobiological model of fear is well underpinned by various studies, the mechanisms of exposure therapy are still under discussion. Partly, this is due to the fact that most neurophysiological methods like fMRI are not able to be used in the natural therapeutic settings.

The current study used in situ measurements of cortical blood oxygenation (O₂Hb) during exposure therapy by means of functional near-infrared spectroscopy. 37 subjects (N = 30 completers) underwent exposure therapy during 5 adapted sessions in which subjects were exposed to Tegenaria Domestica (domestic house spider – experimental condition) and Dendrobaena Veneta/ Eisenaia hortensis (red earthworm – control condition).

Compared to the control condition, patients showed higher O₂Hb levels in the anticipation and exposure phase of spider exposure in areas of the cognitive control network (CCN). Further, significant decreases in O₂Hb were observed during the session accompanied by reductions in fear related symptoms. However, while symptoms decreased in a linear quadratic manner, with higher reductions in the beginning of the session, CCN activity decreased linearly. Further, higher anxiety at the beginning of session one was associated with increased O₂Hb in the CCN. This association decreased within the following sessions.

The current study sheds light on the neuronal mechanisms of exposure therapy. The results are discussed in light of a phase model of exposure therapy that posits a role of cognitive control in the beginning and routine learning at the end of the therapy session.

Using mobile clinics to deliver HIV testing and other basic health services in rural Malawi

CONTEXT

The majority of Malawians are impoverished and primarily dependant on subsistence farming, with 85% of the population living in a rural area. The country is highly affected by HIV and under-resourced rural health centers struggle to meet the government's goal of expanding HIV testing, antiretroviral treatment, and other basic services.

ISSUE

This report describes the work of two four-wheel drive mobile clinics launched in 2008 to fill an identified service gap in the remote areas of Mulanje District, Malawi. The program was developed by an international non-governmental organization, Global AIDS Interfaith Alliance (GAIA), and the Mulanje District Health Office, with funding from the Elizabeth Taylor HIV/AIDS Foundation. The clinics provide: (1) rapid HIV testing and treatment referral; (2) diagnosis and treatment of malaria; (3) sputum collection for TB screening; (4) diagnosis and treatment of sexually transmitted and opportunistic infections; and (5) pre-natal care. The clinic vehicles provide medical supplies and personnel (a clinical officer, nurse, and nurse aide) to set up clinics in community buildings such as churches or schools.

LESSONS LEARNED

In such a project,<strong> </strong>the implementation process and schedule can be affected by medication, supply chain and infrastructural issues, as well as governmental and non-governmental requirements. Timelines should be sufficiently flexible to accommodate unexpected delays. Once established, service scheduling should be flexible and responsive; for instance, malaria treatment rather than HIV testing was most urgently needed in the season when these services were launched. Assessing the impact of healthcare delivery in Malawi is challenging. Although mobile clinic and the government Health Management Information System (HMIS) data were matched, inconsistent variables and gaps in data made direct comparisons difficult. Data collection was compromised by the competing demand of high patient volume; however, rather than reducing the burden on existing health centers, the data suggest<strong> </strong>that the mobile clinics provided services for people who otherwise may not have attended a health center. The GAIA mobile clinics were integrated into a catchment area through a community participation model, allowing point-of-care primary health services to be provided to thousands of people in remote rural villagers. Strong relationships have been forged with local community leaders and with Malawi Ministry of Health officers as the foundation for long-term sustainable engagement and eventual integration of services into Health Ministry programs.

IA-2 autoantibodies in incident type I diabetes patients are associated with a polyadenylation signal polymorphism in GIMAP5

In a large case-control study of Swedish incident type I diabetes patients and controls, 0-34 years of age, we tested the hypothesis that the GIMAP5 gene, a key genetic factor for lymphopenia in spontaneous BioBreeding rat diabetes, is associated with type I diabetes; with islet autoantibodies in incident type I diabetes patients or with age at clinical onset in incident type I diabetes patients. Initial scans of allelic association were followed by more detailed logistic regression modeling that adjusted for known type I diabetes risk factors and potential confounding variables. The single nucleotide polymorphism (SNP) rs6598, located in a polyadenylation signal of GIMAP5, was associated with the presence of significant levels of IA-2 autoantibodies in the type I diabetes patients. Patients with the minor allele A of rs6598 had an increased prevalence of IA-2 autoantibody levels compared to patients without the minor allele (OR=2.2; Bonferroni-corrected P=0.003), after adjusting for age at clinical onset (P=8.0 x 10(-13)) and the numbers of HLA-DQ A1*0501-B1*0201 haplotypes (P=2.4 x 10(-5)) and DQ A1*0301-B1*0302 haplotypes (P=0.002). GIMAP5 polymorphism was not associated with type I diabetes or with GAD65 or insulin autoantibodies, ICA, or age at clinical onset in patients. These data suggest that the GIMAP5 gene is associated with islet autoimmunity in type I diabetes and add to recent findings implicating the same SNP in another autoimmune disease.

Limited joint mobility of the ankle in diabetic patients with cutaneous sensory deficit

Limited joint mobility (LJM) of the ankle joint was measured in 48 diabetic patients classified into three groups: Insulin-dependent diabetes mellitus (IDDM = 15), non-insulin diabetes mellitus (NIDDM = 12) and patients with cutaneous sensory deficit in the foot (CD = 21). Specifically, plantar flexion, dorsiflexion and total range of motion was measured on both feet using goniometric techniques during active and passive movement conditions. No significant bilateral differences were established, therefore values for the right foot were used for statistical analyses. Diabetic patients were matched to 48 non-diabetic controls for age, weight and gender factors. A Semmes-Weinstein monofilament test was used on both feet to assess the integrity of cutaneous sensitivity in all patient and control subjects. Cutaneous sensory deficit patients (CD) had monofilament values greater than two standard deviations below control group mean values. There were no significant differences between the monofilament test values for the IDDM and NIDDM patients and control group data. LJM results indicated both plantar flexion and range of motion in CD patients under active and passive movement conditions were significantly reduced compared to control group data. No differences were observed for any pairwise comparisons between the IDDM and NIDDM groups compared to controls. The data is discussed in terms of the interaction between LJM in the foot and type of diabetic classification.

Sonographic visualization of the ovaries throughout pregnancy

OBJECTIVE

To determine the frequency with which one or both normal ovaries can be visualized during a routine obstetric ultrasound examination.

METHODS

The population consisted of 5617 pregnant women at 5.0-39.9 weeks' gestation, studied cross-sectionally. The sonographic visualization rate for one or both normal ovaries, as well as their position above or below the level of the umbilicus, was recorded for one examination in each patient.

RESULTS

The study population was divided into three groups according to gestational age: first trimester, 5.0-12.9 weeks; second trimester, 13.0-26.9 weeks; and third trimester, 27.0-39.9 weeks. There were 829, 3195, and 1593 women in the first, second, and third trimesters, respectively. Most women were examined transvaginally in the first trimester; transabdominal sonography was used in the second and third trimesters. The ability to visualize one or both ovaries declined significantly (P < .05) from the first trimester to the second, as well as from the second trimester to the third (P < .001). The percentage of ovaries that were visualized above the umbilicus increased from 2.4% in the first trimester to 10.1% in the second trimester (P < .001), and to 21.7% in the third trimester (P < .001).

CONCLUSION

As gestational age advances, there is a significant reduction in the ultrasound visualization rate of normal ovaries. This investigation provides normative data for ovarian visualization throughout pregnancy that may be helpful in establishing ultrasound laboratory standards.

Human biodistribution, dosimetry and clinical use of technetium(III)-99m-Q12

Technetium(III)-99m-Q12, trans-(1,2-bis(dihydro-2,2,5,5-tetramethyl- 3(2H)furanone-4-methyleneimino)ethane)bis(tris(3-methoxy-1-propyl) - phosphine)technetium(III)-99m, is a nonreducible complex of Tc(III) which is herein evaluated as a myocardial perfusion imaging agent.

METHODS

The biodistribution and dosimetry of 99mTc-Q12 were assessed in 10 normal volunteers, while its potential clinical use was evaluated in 70 patients.

RESULTS

Safety parameters measured up to 24 hr postinjection demonstrate no clinically significant drug-related adverse reactions. Technetium(III)-99m-Q12 exhibits good heart uptake (2.2% injected dose at 1 hr postinjection under resting conditions) and no detectable myocardial washout or redistribution up to 5 hr postinjection. The biodistribution is characterized by very rapid hepatobiliary clearance which allows effective myocardial imaging at times as short as 15 min postinjection. Blood and plasma clearances and myocardial uptake are rapid, while lung uptake is minimal. The heart-to-lung and heart-to-liver ratios are higher at stress than at rest, independent of the time elapsed between injection and image acquisition, and independent of whether the patient is fasted or fed after tracer administration. A preliminary correlation shows that 46/47 patients with angiographically demonstrated CAD also have perfusion defects demonstrated by 99mTc-Q12.

CONCLUSIONS

On the basis of the studies reported herein, 99mTc-Q12 appears to be a promising myocardial perfusion imaging agent.

Synthesis and renal excretion of technetium-99m-labeled organic cations

Organic cations are excreted more efficiently than organic anions in uremia suggesting superiority as renal imaging agents. In this study, three 99mTc-labeled cationic cyclam complexes were synthesized and their renal clearance quantified in rats. The complexes are cleared at a rate of about 2.5-3 times that of inulin and about 60% that of p-amino-hipurate. Inhibition of 99Tc-cyclam excretion by quinine indicates transport by the organic cation process. Comparative in vivo imaging experiments demonstrated that in normal rats 99mTc-cyclam reached peak renal activity 1.8 +/- 0.6 min after injection, a value intermediate between that for [131I]OIH (1.0 +/- 0) and 99mTc-MAG3 (2.8 +/- 0.6). In rats injected with the acute nephrotoxin cisplatin, the times to peak were lengthened with the relative order being 99mTc-cyclam > 99mTc-MAG3 > [131I]OIH. The results demonstrate that cationic complexes may be useful for renal imaging diagnostic applications.

Area changes in slices of rat brain during preparation for histology or electron microscopy

Cerebral slices cut from rat brain, either 2-3 mm or 0.27 mm thick, were used to study the effect of embedding and freezing. Paraffin wax sections 6 micrometer thick were mounted and stained with haematoxylin and eosin or Marsland et al.'s (1954) silver stain, and their areas were examined at each step. Embedding in paraffin wax of slices 2-3 mm thick, or in Epon of slices 0.27 mm thick, caused a diminution of their areas by 20-30%. Staining of paraffin wax sections did not alter their areas. Glycerol alone at 15% concentration had no effect on the areas, but at 30% concentration they were diminished by approximately 20%. Diminution of the areas of glycerol treated slices 0.27 mm thick also occurred when they were transferred to liquid N2 or to isopentane, but the areas increased after glycerol was replaced by Freon 12. It was concluded that embedding or freezing cerebral slices caused changes in their areas, but that staining of sections after they had been embedded, sectioned and mounted did not.