Dissociable executive functions in the dynamic control of behavior: inhibition, error detection, and correction

The present study employed event-related fMRI and EEG to investigate the biological basis of the cognitive control of behavior. Using a GO/NOGO task optimized to produce response inhibitions, frequent commission errors, and the opportunity for subsequent behavioral correction, we identified distinct cortical areas associated with each of these specific executive processes. Two cortical systems, one involving right prefrontal and parietal areas and the second regions of the cingulate, underlay inhibitory control. The involvement of these two systems was predicated upon the difficulty or urgency of the inhibition and each was employed to different extents by high- and low-absent-minded subjects. Errors were associated with medial activation incorporating the anterior cingulate and pre-SMA while behavioral alteration subsequent to errors was associated with both the anterior cingulate and the left prefrontal cortex. Furthermore, the EEG data demonstrated that successful response inhibition depended upon the timely activation of cortical areas as predicted by race models of response selection. The results highlight how higher cognitive functions responsible for behavioral control can result from the dynamic interplay of distinct cortical systems.

Designing the national resident assessment instrument for nursing homes

In response to the Omnibus Reconciliation Act of 1987 mandate for the development of a national resident assessment system for nursing facilities, a consortium of professionals developed the first major component of this system, the Minimum Data Set (MDS) for Resident Assessment and Care Screening. A two-state field trial tested the reliability of individual assessment items, the overall performance of the instrument, and the time involved in its application. The trial demonstrated reasonable reliability for 55% of the items and pinpointed redundancy of items and initial design of scales. On the basis of these analyses and clinical input, 40% of the original items were kept, 20% dropped, and 40% altered. The MDS provides a structure and language in which to understand long-term care, design care plans, evaluate quality, and describe the nursing facility population for planning and policy efforts.

Purification and cloning of aggrecanase-1: a member of the ADAMTS family of proteins

We purified, cloned, and expressed aggrecanase, a protease that is thought to be responsible for the degradation of cartilage aggrecan in arthritic diseases. Aggrecanase-1 [a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4)] is a member of the ADAMTS protein family that cleaves aggrecan at the glutamic acid-373-alanine-374 bond. The identification of this protease provides a specific target for the development of therapeutics to prevent cartilage degradation in arthritis.

Attention deficit hyperactivity disorder adults: comorbidities and adaptive impairments

Attention deficit hyperactivity disorder (ADHD) is increasingly recognized as a legitimate adult diagnostic category. Yet the nature of and comorbidities and adaptive impairments associated with adult ADHD have received little scientific investigation. The present study, therefore, compared 172 adults diagnosed with ADHD with 30 adults referred to the same adult ADHD clinic who were not so diagnosed. The ADHD group showed a significantly greater prevalence of oppositional, conduct, and substance abuse disorders, and greater illegal substance use than control adults. Moreover, adults with ADHD displayed greater self-reported psychological maladjustment, more driving risks (speeding violations), and more frequent changes in employment. Significantly more ADHD adults had experienced a suspension of their driver license, had performed poorly, quit, or been fired from their job, and had a history of poorer educational performance and more frequent school disciplinary actions against them than adults without ADHD. Multiple marriages were more likely in the ADHD group as well. Contrary to previous studies, anxiety and mood disorders were not found to be more prevalent in the ADHD than in the control group. Results suggest that ADHD in adults is associated with relatively specific risks for disruptive behavior disorders, school and job performance problems, and driving risks.

Heterogeneity of intracellular cytokine synthesis at the single-cell level in polarized T helper 1 and T helper 2 populations

CD4+ T helper (Th) cells can be classified into different types based on their cytokine profile. Cells with these polarized patterns of cytokine production have been termed Th1 and Th2, and can be distinguished functionally by the production of IFN-gamma and IL-4, respectively. These phenotypes are crucial in determining the type of immune response that develops after antigen priming. There are no surface markers that define them, and cytokine immunoassay or mRNA analysis both have limitations for characterization of single cells. Using immunofluorescent detection of intracellular IFN-gamma and IL-4, we have studied the emergence of Th1 and Th2 cells in response to antigen exposure and the patterns of cytokine synthesis in established T cell clones. IFN-gamma production by Th1 clones was detectable in almost all cells by 4 h, and it continued in most cells for > 24 h. IL-4 production in Th2 cells peaked at 4 h, but declined rapidly. In Th0 cells containing both cytokines, fewer cells produced IFN-gamma, which did not appear until IL-4 synthesis declined. Cocultivation of clones showed no such cross-regulation. Antigen stimulation of transgenic T cells expressing an ovalbumin-specific T cell receptor generated Th2 cells, probably as a result of endogenous IL-4 production. Addition of IL-12 and/or anti-IL-4 caused Th1 cells to develop, while some Th0 cells were seen when IL-12 alone was added. These results show that stimulation in the presence of polarizing stimuli results in cells producing either IFN-gamma or IL-4, but that coproduction can occur in rare cells under defined conditions.

Separate neural subsystems within 'Wernicke's area'

Over time, both the functional and anatomical boundaries of 'Wernicke's area' have become so broad as to be meaningless. We have re-analysed four functional neuroimaging (PET) studies, three previously published and one unpublished, to identify anatomically separable, functional subsystems in the left superior temporal cortex posterior to primary auditory cortex. From the results we identified a posterior stream of auditory processing. One part, directed along the supratemporal cortical plane, responded to both non-speech and speech sounds, including the sound of the speaker's own voice. Activity in its most posterior and medial part, at the junction with the inferior parietal lobe, was linked to speech production rather than perception. The second, more lateral and ventral part lay in the posterior left superior temporal sulcus, a region that responded to an external source of speech. In addition, this region was activated by the recall of lists of words during verbal fluency tasks. The results are compatible with an hypothesis that the posterior superior temporal cortex is specialized for processes involved in the mimicry of sounds, including repetition, the specific role of the posterior left superior temporal sulcus being to transiently represent phonetic sequences, whether heard or internally generated and rehearsed. These processes are central to the acquisition of long- term lexical memories of novel words.

Cloning and characterization of ADAMTS11, an aggrecanase from the ADAMTS family

Aggrecan is responsible for the mechanical properties of cartilage. One of the earliest changes observed in arthritis is the depletion of cartilage aggrecan due to increased proteolytic cleavage within the interglobular domain. Two major sites of cleavage have been identified in this region at Asn(341)-Phe(342) and Glu(373)-Ala(374). While several matrix metalloproteinases have been shown to cleave at Asn(341)-Phe(342), an as yet unidentified protein termed "aggrecanase" is responsible for cleavage at Glu(373)-Ala(374) and is hypothesized to play a pivotal role in cartilage damage. We have identified and cloned a novel disintegrin metalloproteinase with thrombospondin motifs that possesses aggrecanase activity, ADAMTS11 (aggrecanase-2), which has extensive homology to ADAMTS4 (aggrecanase-1) and the inflammation-associated gene ADAMTS1. ADAMTS11 possesses a number of conserved domains that have been shown to play a role in integrin binding, cell-cell interactions, and extracellular matrix binding. We have expressed recombinant human ADAMTS11 in insect cells and shown that it cleaves aggrecan at the Glu(373)-Ala(374) site, with the cleavage pattern and inhibitor profile being indistinguishable from that observed with native aggrecanase. A comparison of the structure and expression patterns of ADAMTS11, ADAMTS4, and ADAMTS1 is also described. Our findings will facilitate the study of the mechanisms of cartilage degradation and provide targets to search for effective inhibitors of cartilage depletion in arthritic disease.

Reversibility of T helper 1 and 2 populations is lost after long-term stimulation

Commitment of T helper 1 (Th1) or Th2 populations developing during an immune response to a pathogen, or an inappropriate immune response to an allergen or autoantigen, may determine the difference between health and chronic disease. We show that strongly polarized Th1 and Th2 populations assessed by immunoassay are heterogeneous using flow cytometry to detect single cells producing interferon gamma (IFN-gamma) and interleukin 4 (IL-4). Th1 populations arising after 1 wk of stimulation in IL-12 plus anti-IL-4 antibodies could convert to Th2 cells when restimulated in IL-4. Th2 populations resulting from stimulation for 1 wk in IL-4 could give rise to Th1 cells upon restimulation in IL-12 plus anti-IL-4. In contrast, the cytokine profiles of long-term Th1 and Th2 populations arising originally from repeated stimulation in IL-12 or IL-4 appeared more homogeneous and were not reversible, although IL-4 dramatically reduced the number of IFN-gamma-producing Th1 cells. This may explain previous reports that Th1 cells can be converted to Th2 cells.

A cat cloned by nuclear transplantation

Sheep, mice, cattle, goats and pigs have all been cloned by transfer of a donor cell nucleus into an enucleated ovum, and now we add the successful cloning of a cat (Felis domesticus) to this list. However, this cloning technology may not be readily extendable to other mammalian species if our understanding of their reproductive processes is limited or if there are species-specific obstacles.

Role of cytokines in determining T-lymphocyte function

Early events in an immune response stimulate the production of cytokines that direct the subsequent development of T-helper (Th) subsets with discrete patterns of cytokine production. These events are dictated by the type of antigen/microorganism administered to a host, as well as dose and route of immunization. Bacterial stimuli activate macrophages of the innate immune response to produce IL-12 and drive Th1 development and cell-mediated immunity. Conversely, production of IL-4 early in an immune response favors a Th2 or allergic/humoral immune response. The ability of IL-4 and IL-10 to inhibit Th1 development and effector function, as well as the requirement of committed Th1 cells for co-stimulators to induce maximal IFN-gamma production, suggests that cell-mediated immunity is under strict control, probably to achieve immunity with minimum immunopathology.

B7 and interleukin 12 cooperate for proliferation and interferon gamma production by mouse T helper clones that are unresponsive to B7 costimulation

We have previously shown that dendritic cells isolated after overnight culture, which can express B7 and are potent stimulators of naive T cell proliferation, are relatively poor at inducing the proliferation of a panel of murine T helper 1 (Th1) clones. Maximal stimulation of Th1 clones was achieved using unseparated splenic antigen presenting cells (APC). An explanation for these findings is provided in the present study where we show that FcR+ L cells transfected with B7 stimulate minimal proliferation of Th1 clones in response to anti-CD3 antibodies, in contrast to induction of significant proliferation of naive T cells. However, addition of interleukin 12 (IL-12) to cultures of Th1 cells stimulated with anti-CD3 and FcR+ B7 transfectants resulted in a very pronounced increase in proliferation and interferon gamma (IFN-gamma) production. Exogenous IL-12 did not affect the B7-induced proliferation of naive T cells. This showed that whereas costimulatory signals delivered via B7-CD28 interaction are sufficient to induce significant proliferation of naive T cells activated through occupancy of the T cell receptor, Th1 T cell clones require cooperative costimulation by B7 and IL-12. This costimulation was shown to be specific by inhibition of proliferation and IFN-gamma production using chimeric soluble cytolytic T lymphocyte-associated antigen 4-human IgG1Fc (CTLA4-Ig) and anti-IL-12 antibodies. Furthermore, the significant antigen specific proliferation and IFN-gamma production by Th1 clones observed when splenocytes were used as APC was almost completely abrogated using CTLA4-Ig and anti-IL-12 antibodies. Thus two costimulatory signals, B7 and IL-12, account for the ability of splenic APC to induce maximal stimulation of Th1 clones. IL-10 downregulates the expression of IL-12 by IFN-gamma-stimulated macrophages and this may account largely for t the ability of IL-10 to inhibit APC function of splenic and macrophage APC for the induction of Th1 cell proliferation and IFN-gamma production. Indeed we show that IL-12 can overcome the inhibitory effect of IL-10 for the APC-dependent induction of proliferation and IFN-gamma production by Th1 clones. These results suggest that proliferation by terminally differentiated Th1 clones, in contrast to naive T cells, requires stimulation via membrane-bound B7 and a cytokine, IL-12. It is possible that these signals may result in the activation of unresponsive T cells during an inflammatory response. IL-10, by its role in regulating such innate inflammatory responses, may thus help to maintain these T cells in an unresponsive state.

The present and future disease burden of hepatitis C virus (HCV) infection with today's treatment paradigm

The disease burden of hepatitis C virus (HCV) is expected to increase as the infected population ages. A modelling approach was used to estimate the total number of viremic infections, diagnosed, treated and new infections in 2013. In addition, the model was used to estimate the change in the total number of HCV infections, the disease progression and mortality in 2013-2030. Finally, expert panel consensus was used to capture current treatment practices in each country. Using today's treatment paradigm, the total number of HCV infections is projected to decline or remain flat in all countries studied. However, in the same time period, the number of individuals with late-stage liver disease is projected to increase. This study concluded that the current treatment rate and efficacy are not sufficient to manage the disease burden of HCV. Thus, alternative strategies are required to keep the number of HCV individuals with advanced liver disease and liver-related deaths from increasing.

²¹³Bi-DOTATOC receptor-targeted alpha-radionuclide therapy induces remission in neuroendocrine tumours refractory to beta radiation: a first-in-human experience

Purpose

Radiopeptide therapy using a somatostatin analogue labelled with a beta emitter such as ⁹⁰Y/¹⁷⁷Lu-DOTATOC is a new therapeutic option in neuroendocrine cancer. Alternative treatments for patients with refractory disease are rare. Here we report the first-in-human experience with ²¹³Bi-DOTATOC targeted alpha therapy (TAT) in patients pretreated with beta emitters.

Methods

Seven patients with progressive advanced neuroendocrine liver metastases refractory to treatment with ⁹⁰Y/¹⁷⁷Lu-DOTATOC were treated with an intraarterial infusion of ²¹³Bi-DOTATOC, and one patient with bone marrow carcinosis was treated with a systemic infusion of ²¹³Bi-DOTATOC. Haematological, kidney and endocrine toxicities were assessed according to CTCAE criteria. Radiological response was assessed with contrast-enhanced MRI and ⁶⁸Ga-DOTATOC-PET/CT. More than 2 years of follow-up were available in seven patients.

Results

The biodistribution of ²¹³Bi-DOTATOC was evaluable with 440 keV gamma emission scans, and demonstrated specific tumour binding. Enduring responses were observed in all treated patients. Chronic kidney toxicity was moderate. Acute haematotoxicity was even less pronounced than with the preceding beta therapies.

Conclusion

TAT can induce remission of tumours refractory to beta radiation with favourable acute and mid-term toxicity at therapeutic effective doses.

Electronic supplementary material

The online version of this article (doi:10.1007/s00259-014-2857-9) contains supplementary material, which is available to authorized users.

Four-year follow-up of Palmaz-Schatz stent revascularization as treatment for atherosclerotic renal artery stenosis

BACKGROUND

Stent revascularization is perceived as superior to balloon angioplasty and surgical revascularization, but the paucity of stent publications precludes even historical comparison with surgical data.

METHODS AND RESULTS

Palmaz-Schatz stent revascularization of renal artery stenosis was successfully performed on 163 consecutive patients for poorly controlled hypertension or preservation of renal function. Of these, 145 were eligible for > or =6-month clinical follow-up of the effect of the procedure on renal function, blood pressure control, number of antihypertensive medications, and survival. At 4 years, systolic and diastolic blood pressures significantly decreased (from 166+/-26 to 148+/-22 mm Hg and from 86+/-14 to 80+/-11 mm Hg, respectively; P<0.05), and blood pressure control was more facile in approximately half of the patients. Creatinine decreased or remained stable in approximately two thirds of the patients. The cumulative probability of survival was 74+/-4% at 3 years, with few deaths related to end-stage renal disease. Survival was good in patients with normal (92+/-4%) baseline renal function, fair (74+/-7%) in those with mildly impaired renal function, and poor (52+/-7%) in patients with elevated baseline creatinine levels (> or =2.0 mg/dL). The combination of impaired renal function and bilateral disease adversely affected survival.

CONCLUSIONS

Renal artery stent revascularization in the presence of normal or mildly impaired renal function had a beneficial effect on blood pressure control and a nondeleterious effect on renal function. Survival was adversely affected by renal dysfunction despite adequate revascularization. Early diagnosis and adequate revascularization before the onset of renal dysfunction could beneficially affect blood pressure control, preserve or prevent deterioration of renal function, and improve patient survival.

Reflection: a review of the literature

This paper is a review of the literature on reflection. The purpose was to unravel and make sense of the complex literature, and to identify the skills required to engage in reflection. An analysis of the literature revealed that differences between authors' accounts of reflective processes are largely those of terminology, detail and the extent to which these processes are arranged in a hierarchy. Key stages of reflection are identified and represented by a model. Skills required to engage in reflection were found to be implicit in the literature and these are identified. Methodological issues related to empirical literature are discussed. It is suggested that reflection is an important learning tool in professional education and that the skills required for reflection need to be developed in professional courses.

Breathlessness in humans activates insular cortex

Dyspnea (shortness of breath, breathlessness) is a major and disabling symptom of heart and lung disease. The representation of dyspnea in the cerebral cortex is unknown. In the first study designed to explore the central neural structures underlying perception of dyspnea, we evoked the perception of severe 'air hunger' in healthy subjects by restraining ventilation below spontaneous levels while holding arterial oxygen and carbon dioxide levels constant. PET revealed that air hunger activated the insular cortex. The insula is a limbic structure also activated by visceral stimuli, temperature, taste, nausea and pain. Like dyspnea, such perceptions underlie behaviors essential to homeostasis and survival.

6-C-kine (SLC), a lymphocyte adhesion-triggering chemokine expressed by high endothelium, is an agonist for the MIP-3beta receptor CCR7

The beta chemokine known as 6-C-kine, secondary lymphoid-tissue chemokine (SLC), TCA4, or Exodus-2 (herein referred to as 6CK/SLC) can trigger rapid integrin-dependent arrest of lymphocytes rolling under physiological shear and is highly expressed by high endothelial venules, specialized vessels involved in lymphocyte homing from the blood into lymph nodes and Peyer's patches. We show that 6CK/SLC is an agonist for the lymphocyte chemoattractant receptor, CCR7 (EBI-1, BLR-2), previously described as a receptor for the related beta chemokine MIP-3beta (ELC or Exodus-3). Moreover, 6CK/SLC and MIP-3beta attract the same major populations of circulating lymphocytes, including naive and memory T cells > B cells (but not natural killer cells); desensitization to MIP-3beta inhibits lymphocyte chemotaxis to 6CK/SLC but not to the alpha chemokine SDF-1 (stromal cell-derived factor); and 6CK/SLC competes for MIP-3beta binding to resting mouse lymphocytes. The findings suggest that the majority of circulating lymphocytes respond to 6CK/SLC and MIP-3beta in large part through their common receptor CCR7 and that these molecules may be important mediators of physiological lymphocyte recirculation in vivo.

Expression cloning of the STRL33/BONZO/TYMSTRligand reveals elements of CC, CXC, and CX3C chemokines

STRL33/BONZO/TYMSTR is an orphan chemokine and HIV/SIV coreceptor receptor that is expressed on activated T lymphocytes. We describe an expression cloning strategy whereby we isolated a novel chemokine, which we name CXCL16. CXCL16 is an alpha (CXC) chemokine but also has characteristics of CC chemokines and a structure similar to fractalkine (neurotactin) in having a transmembrane region and a chemokine domain suspended by a mucin-like stalk. A recombinant version of CXCL16 fails to mediate chemotaxis to all known chemokine receptor transfectants tested but does mediate robust chemotaxis, high affinity binding, and calcium mobilization to Bonzo receptor transfectants, indicating that this is a unique receptor ligand interaction. In vitro polarized T cell subsets including Th1, Th2, and Tr1 cells express functional Bonzo, suggesting expression of this receptor in chronic inflammation, which we further verified by demonstration of CXCL16-mediated migration of tonsil-derived CD4(+) T lymphocytes. CXCL16 is expressed on the surface of APCs including subsets of CD19(+) B cells and CD14(+) monocyte/macrophages, and functional CXCL16 is also shed from macrophages. The combination of unique structural features of both Bonzo and CXCL16 suggest that this interaction may represent a new class of ligands for this receptor family. Additionally, this chemokine might play a unique dual role of attracting activated lymphocyte subsets during inflammation as well as facilitating immune responses via cell-cell contact.

D1-dopamine receptor agonists selectively activate striatal c-fos independent of rotational behaviour

L-Dopa and dopaminergic agonists selective for the D1- or D2-dopamine receptor subtype induce contraversive rotation in rats which have been unilaterally lesioned with injections of 6-hydroxydopamine (6-OHDA) into the substantia nigra. D-Amphetamine, which releases dopamine from neurones on the unlesioned side of the animal, causes ipsiversive rotation. These increases in rotational behaviour are mediated, at least in part, by dopamine receptors in the striatum. In unilaterally lesioned animals, L-dopa and the D1-selective agonists SKF 38393 and CY 208-243 produce contralateral rotation and induction of the nuclear proto-oncogene c-fos in the lesioned striatum. D-Amphetamine induces both ipsilateral rotation and c-fos activation in the intact striatum. Three lines of evidence, however, dissociate fos induction and rotation. First, LY 171555, a selective D2-dopamine receptor agonist, also induces contraversive rotation but this rotation is not accompanied by c-fos activation in striatum. Second, D1-dopamine agonists produce activation of striatal c-fos even if rotation is prevented by an anaesthetic. Third, rotation induced by injection of SKF 38393 into substantia nigra is not accompanied by c-fos induction. These results suggest a mechanism by which D1-dopamine receptor mechanisms may regulate long-term changes in dopaminergic systems.

A topography of executive functions and their interactions revealed by functional magnetic resonance imaging

We used fMRI to study the brain processes involved in the executive control of behavior. The Sustained Attention to Response Task (SART), which allows unpredictable and predictable NOGO events to be contrasted, was imaged using a mixed (block and event-related) fMRI design to examine tonic and phasic processes involved in response inhibition, error detection, conflict monitoring and sustained attention. A network of regions, including right ventral prefrontal cortex (PFC), left dorsolateral PFC (DLPFC) and right inferior parietal cortex, was activated for successful unpredictable inhibitions, while rostral anterior cingulate was implicated in error processing and the pre-SMA in conflict monitoring. Furthermore, the pattern of correlations between left dorsolateral PFC, implicated in task-set maintenance, and the pre-SMA were indicative of a tight coupling between prefrontally mediated control and conflict levels monitored more posteriorly. The results reveal that the executive control of behavior can be separated into distinct functions performed by discrete cortical regions.

A combined linkage-physical map of the human genome

We have constructed de novo a high-resolution genetic map that includes the largest set, to our knowledge, of polymorphic markers (N=14,759) for which genotype data are publicly available; that combines genotype data from both the Centre d'Etude du Polymorphisme Humain (CEPH) and deCODE pedigrees; that incorporates single-nucleotide polymorphisms; and that also incorporates sequence-based positional information. The position of all markers on our map is corroborated by both genomic sequence and recombination-based data. This specific combination of features maximizes marker inclusion, coverage, and resolution, making this map uniquely suitable as a comprehensive resource for determining genetic map information (order and distances) for any large set of polymorphic markers.

Vertebroplasty: clinical experience and follow-up results

This study was undertaken to report the clinical experience with percutaneous minimal invasive vertebroplasty using polymethyl-methacrylcate (PMMA) for a consecutive group of patients. Over the period of the last 4 years, 40 patients were treated at 68 vertebral segment levels with the intention to relieve pain related to vertebral body lesions. Reduced vertebral body height and destruction of the posterior vertebral wall were not considered to be exclusion criterias. The vertebroplasty procedure was performed under general anesthesia and in prone position with imaging control using mostly biplane DSA fluoroscopic guidance, and rarely with single-plane mobile DSA combined with computed tomographic guidance. Unilateral, but more frequently bilateral, transpedicular introduction of a 2-3-mm OD needle was followed by an injection of polymethyl-methacrylcate (PMMA). PMMA preparation involved a diluted mixture (20 mL powder for 5 mL liquid) allowing for an extended polymerization time of up to 8 min. The PMMA was mixed with metallic powder to enhance its radio-opacity. Before PMMA injection, a vertebral phlebography was obtained to evaluate the filling pattern and identify sites of potential PMMA leakage. Injection of opacified PMMA was performed under continuous visual control with fluoroscopy to obtain adequate filling and to avoid important PMMA leakage. Clinical follow-up involved an evaluation using a questionnaire for assessment of pain, pain medication, and mobility. One to six levels were treated in one to three treatment sessions for patients with metastatic, osteoporotic, and hemangiomatous lesions of the vertebral bodies who presented with pain. The results observed matched those reported previously with a success rate of approximately 80% and a complication rate below 6% per treated level. Treatment failure and complications observed were related to leakage, insufficient pretreatment evaluation, anesthesia, or patient position during treatment. Image guidance with fluoroscopy was efficient both for precise transpedicular approach and PMMA implantation control. Vertebroplasty is very efficient for treatment of pain. Treatment failure was mostly related to insufficient pretreatment clinical evaluation, and complication due to excessive PMMA volume injection. Control of PMMA volume seems to be the most critical point for avoiding complications. A good fluoroscopy control is therefore mandatory.

Interferon therapy for condylomata acuminata

Current therapy for condylomata acuminata (genital warts) is not consistently effective. Therefore, we conducted a randomized, double-blind trial to compare interferon alpha-2b with placebo in the treatment of this disorder. Our rationale was that interferon has both antiproliferative and antiviral properties. The placebo or interferon (1 X 10(6) IU) was injected directly into one to three warts three times weekly for three weeks. The injections were well tolerated by both groups of patients. The side effects of fever, chills, myalgia, headache, fatigue, and leukopenia occurred more commonly in the interferon group than in the placebo group, but such effects rarely disrupted daily routines. Only 13 of 296 patients (4 percent) discontinued therapy because of side effects (11 in the interferon group and 2 in the placebo group). Twenty-six other patients were excluded from analysis because of a loss to follow-up or other deviations from protocol, thus leaving 257 patients in the final evaluation. At one week after the completion of therapy, interferon had produced a large and significantly greater reduction in mean wart area (a 62.4 percent decrease), as compared with placebo (a 1.2 percent increase in mean area) (P less than 0.001). At the conclusion of the study (13 weeks after the completion of therapy), the mean wart area was still decreased 39.9 percent below the initial size in the interferon group, whereas it had increased by 46 percent over base-line measurements in the placebo group (P less than 0.001). At the same time, all treated warts had completely cleared in 36 percent of the interferon recipients and in 17 percent of the placebo recipients (P less than 0.001), whereas treated warts progressed in 13 percent of the interferon recipients and in 50 percent of the placebo recipients (P less than 0.001). We conclude that injection of interferon alpha-2b directly into genital warts appears to be an effective and fairly well-tolerated form of therapy.

Subcortical aphasia and neglect in acute stroke: the role of cortical hypoperfusion

We have hypothesized that most cases of aphasia or hemispatial neglect due to acute, subcortical infarct can be accounted for by concurrent cortical hypoperfusion. To test this hypothesis, we demonstrate: (i) that pure subcortical infarctions are associated with cortical hypoperfusion in subjects with aphasia/neglect; (ii) that reversal of cortical hypoperfusion is associated with resolution of the aphasia; and (iii) that aphasia/neglect strongly predicts cortical ischaemia and/or hypoperfusion. We prospectively evaluated a consecutive series of 115 patients who presented within 24 h of onset or progression of stroke symptoms, with MRI sequences including diffusion weighted imaging (DWI) and perfusion weighted imaging (PWI), and detailed testing for aphasia or hemispatial neglect. The association between aphasia or neglect and cortical infarct (or dense ischaemia) on DWI and cortical hypoperfusion indicated by PWI, was evaluated with chi-squared analyses. Fisher exact tests were used for analyses with small samples. Cases of DWI lesion restricted to subcortical white matter and/or grey matter structures (n = 44) were examined for the presence of aphasia or neglect, and for the presence of cortical hypoperfusion. In addition, subjects who received intervention to restore perfusion were evaluated with DWI, PWI, and cognitive tests before and after intervention. Finally, the positive predictive value of the cognitive deficits for identifying cortical abnormalities on DWI and PWI were calculated from all patients. Of the subjects with only subcortical lesions on DWI in this study (n = 44), all those who had aphasia or neglect showed concurrent cortical hypoperfusion. Among the patients who received intervention that successfully restored cortical perfusion, 100% (six out of six) showed immediate resolution of aphasia. In the 115 patients, aphasia and neglect were much more strongly associated with cortical hypoperfusion (chi(2) = 57.3 for aphasia; chi(2) = 28.7 for neglect; d.f. = 1; P < 0.000001 for each), than with cortical infarct/ischaemia on DWI (chi(2) = 8.5 for aphasia; chi(2) = 9.7 for neglect; d.f. = 1; P < 0.005 for each). Aphasia showed a much higher positive predictive value for cortical abnormality on PWI (95%) than on DWI (62%), as did neglect (100% positive predictive value for PWI versus 74% for DWI). From these data we conclude that aphasia and neglect due to acute subcortical stroke can be largely explained by cortical hypoperfusion.

Evidence for reflex upper airway dilator muscle activation by sudden negative airway pressure in man

1. To determine if negative upper airway pressure causes reflex pharyngeal dilator muscle activation, we used intra-oral bipolar surface electrodes to record genioglossus electromyogram (EMG) activity in response to 500 ms duration pressure stimuli of 0, -2.5, -5, -15, -25 and -35 cm H2O (0-90% rise time less than 30 ms) in ten normal, conscious, supine subjects. 2. With the subjects relaxed at end-expiration, stimuli were applied in each of three conditions: (i) glottis open (GO), (ii) glottis closed (GC) and (iii) controls with the mouth and nose closed. 3. Six rectified and integrated EMG responses were bin averaged for each pressure in each experimental condition. Response latency was defined as the time when the EMG activity significantly increased above pre-stimulus levels. Response magnitude was quantified as the ratio of the EMG activity for 80 ms post-stimulus to 80 ms prestimulus; data from after the subject's voluntary reaction time (for tongue protrusion) were not analysed. 4. Negative airway pressure activated the genioglossus. The median latency of activation (34 ms) was much faster than the time for voluntary activation (184 ms) indicating a reflex response. 5. Significant activation, compared to 0 cmH2O controls and controls with mouth and nose closed, occurred with pressures of at least -5 cm H2O (GC) and -15 cm H2O (GO). At -25 and -35 cm H2O, responses with GO were significantly greater than with GC. 6. The magnitude ('strength') of the responses differed between subjects; these differences were repeatable. 7. We conclude that negative airway pressure causes reflex pharyngeal dilator muscle activation in man. Responses with GC suggest that upper airway receptors can mediate the response but larger responses with GO indicate a contribution from subglottal receptors.