Is the velocity-curvature relationship disrupted in apraxic patients?

Velocity and curvature of human movements are linked by a proportionality relationship (power-law) whose origin has been attributed either to functional properties of cortical areas or to peripheral constraints. 3D movements made by apraxic patients show a time-shift between velocity and curvature which has been considered as a disruption of the power-law, supporting the central hypothesis. We analysed the power-law in 2D drawing-like movements in healthy subjects and apraxic patients (correlation and cross-correlation analyses). The power-law remained preserved in apraxic patients, suggesting that the velocity-curvature relationship is not globally disrupted and thus that the power-law cannot be only attributed to central planning mechanisms in those associative brain areas injured in apraxic patients.

Disseminierte eruptive Syringome bei Down-Syndrom

A 42-year-old male with Down's syndrome suddenly developed disseminated red-brown papules. Histological studies revealed eruptive syringomas. We discuss the association of Down syndrome with different skin diseases, in particular with syringomas.

Optimization of desflurane administration in morbidly obese patients: a comparison with sevoflurane using an ‘inhalation bolus’ technique

BACKGROUND

The concept of an 'inhalation bolus' can be used to optimize inhaled drug administration. We investigated the depth of anaesthesia, haemodynamic stability, and recovery time in morbidly obese patients resulting from bispectral index (BIS)-guided sevoflurane or desflurane administration and BIS-triggered inhalation boluses of sevoflurane or desflurane combined with titration of remifentanil.

METHODS

Fifty morbidly obese patients undergoing laparoscopic gastroplasty received either BIS-guided sevoflurane or desflurane anaesthesia in combination with a remifentanil target-controlled infusion. Intraoperative haemodynamic stability and BIS control were measured. Immediate recovery was recorded.

RESULTS

Intraoperatively, the BIS was between 40 and 60 for a greater percentage of time in the sevoflurane (78 (13)% of case time) than in the desflurane patients (64 (14)% of case time), owing to too profound anaesthesia in the desflurane patients at the start of the procedure. However, fewer episodes of hypotension were found in the desflurane group, without the occurrence of more hypertensive episodes. During immediate recovery, eye opening, extubation, airway maintenance, and orientation occurred sooner in the desflurane group.

CONCLUSIONS

Immediate recovery was significantly faster in the desflurane group. Overall hypnotic controllability measured by BIS was less accurate with desflurane. Overall haemodynamic controllability was better when using desflurane. Fewer episodes of hypotension were found in the desflurane group. The use of the inhalation bolus was found to be appropriate in both groups without causing severe haemodynamic side effects. Minimal BIS values were significantly lower after a desflurane bolus.

Trash feet after coronary angiography

Cholesterol crystal embolisation is a frequently underdiagnosed condition. While coronary catheterisation is safe and commonly performed, the reported patient developed very painful trash feet after undergoing this routine procedure. Ulceration and gangrene occurred after catheter manipulation during cardiac angiography, which caused occlusion of the small arteries in his feet. The triad of pain, livedo reticularis, and intact peripheral pulses is pathognomonic for cholesterol embolisation. The prognosis depends on the extent of the systemic disease and a high rate of mortality (75-80%) is observed. Prognosis is poor and the treatment is only supportive. It is suggested that while cardiac catheterisation is largely safe and a very commonly performed procedure, it can still lead to complications with serious side effects and can even prove fatal.

[Thorascopic coronary surgery. Current status and future perspectives]

Thorascopic coronary surgery has achieved great progress in the past few years. After computer-directed instrument systems were introduced, which enabled high precision and expanded mobility in close quarters, the limitations of conventional endoscopic instruments were largely overcome. Employing modern surgical telemanipulators and endoscopic stabilizers, entirely endoscopic myocardial revascularization of the anterior wall is being successfully performed during off-pump surgery. Longer operating times and conversion rates in about one-fifth of the patients due to technical and anatomical limitations still restrict the use of these new surgical techniques compared to conventional surgery. Development of further technologies and integration of video-assisted navigation systems will broaden the application of computer-assisted instrument systems in the near future.

Cooling for newborns with hypoxic ischaemic encephalopathy

BACKGROUND

Newborn animal and human pilot studies suggest that mild hypothermia following peripartum hypoxia-ischaemia in newborn infants may reduce neurological sequelae, without adverse effects.

OBJECTIVES

To determine whether therapeutic hypothermia in encephalopathic asphyxiated newborn infants reduces mortality and long-term neurodevelopmental disability, without clinically important side effects.

SEARCH STRATEGY

The standard search strategy of the Neonatal Review Group as outlined in the Cochrane Library (Issue 2, 2003) was used. Randomised controlled trials evaluating therapeutic hypothermia in term newborns with hypoxic ischaemic encephalopathy were identified by searching the Oxford Database of Perinatal Trials, the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library Issue Issue 2, 2003), MEDLINE (1966 to July 2003), previous reviews including cross-references, abstracts, conferences, symposia proceedings, expert informants and journal hand searching.

SELECTION CRITERIA

Randomised controlled trials comparing the use of therapeutic hypothermia with normothermia in encephalopathic newborn infants with evidence of peripartum asphyxia and without recognisable major congenital anomalies were included. The primary outcome measure was death or long-term major neurodevelopmental disability. Other outcomes included adverse effects of cooling and 'early' indicators of neurodevelopmental outcome.

DATA COLLECTION AND ANALYSIS

Three reviewers independently selected, assessed the quality of and extracted data from the included studies. Authors were contacted for further information. Meta-analyses were performed using relative risk and risk difference for dichotomous data, and weighted mean difference for continuous data with 95% confidence intervals.

MAIN RESULTS

Two randomised controlled trials were included in this review, comprising 50 term infants with moderate/ severe encephalopathy and evidence of intrapartum asphyxia. There was no significant effect of therapeutic hypothermia on the combined outcome of death or major neurodevelopmental disability in survivors followed. No adverse effects of hypothermia on short term medical outcomes or on some 'early' indicators of neurodevelopmental outcome were detected.

REVIEWER'S CONCLUSIONS

Although two small randomised controlled trials demonstrated neither evidence of benefit or harm, current evidence is inadequate to assess either safety or efficacy of therapeutic hypothermia in newborn infants with hypoxic ischaemic encephalopathy. Therapeutic hypothermia for encephalopathic asphyxiated newborn infants should be further evaluated in well designed randomised controlled trials.

Topical 5% imiquimod long-term treatment of cutaneous warts resistant to standard therapy modalities

BACKGROUND

Long-lasting cutaneous warts may represent an unbearable stigma to patients and therefore pose a singular challenge for the physician. Generally, these warts are induced by human papillomavirus (HPV) 2, HPV-27 or HPV-57.

OBJECTIVES

The present study was conducted to evaluate the efficacy and safety of long-term treatment with imiquimod 5% cream applied to long-lasting (mean duration 6.3 years) common warts, which had been resistant to previous therapeutic interventions.

PATIENTS AND METHODS

Imiquimod cream was self-applied by the patients twice daily. Assessment of response and occurrence of side-effects was performed every 4 weeks until clinical cure or up to a maximum of 24 weeks. A total of 37 patients were recruited.

RESULTS

31 out of 37 patients completed the treatment. 10 out of 37 patients experienced a total clearance of their warts (27%). The mean duration to clearance was 19.2 weeks. 18 patients (49%) showed a reduction of more than 50% and 5 patients (14%) a reduction of less than 50%.

CONCLUSION

Our data demonstrate that the long-term topical application of imiquimod 5% cream is an effective treatment for otherwise therapy-resistant cutaneous warts without causing any meaningful side-effects.

Functional heterogeneity within Broca's area during verbal working memory

In previous fMRI research, we found that two subregions of the left inferior frontal cortex showed distinct patterns of activity during a verbal working memory task. Specifically, a more dorsal region tracked with performance, while a more ventral region was sensitive to lexical status. To test the veracity of this finding, we developed a new method for meta-analysis of neuroimaging results. In this method, Gaussian probability distributions are formed around stereotaxic coordinates obtained from published neuroimaging studies. These probability distributions are then combined to identify regions of convergence across studies. When this method was applied to prior studies of working memory, the results largely paralleled those from earlier reviews of the literature on working memory, but also confirmed our empirical findings showing distinct foci within Broca's area. Further application of this meta-analytic technique substantiated the dissociation in these regions for performance and sublexical processing. These results help to validate a novel approach for meta-analysis of neuroimaging findings that avoids many of the subjective assumptions involved in alternative approaches.

Efficacy of imiquimod 5% cream in the treatment of recalcitrant warts in children

Long-lasting cutaneous warts are a therapeutic challenge, especially widespread or symptomatic recalcitrant warts in children. It can be speculated that natural immunity to these human papillomavirus (HPV)- induced lesions is extremely poor. Therefore ideally treatment should focus on increasing local immune response. Recently imiquimod, a topical immune modifier, has been successfully used in the treatment of external genital warts. Our purpose is to report on our experiences with imiquimod 5% cream applied to therapy-resistant, long-lasting (duration 2-7 years) common warts in children. In 18 children, imiquimod cream was self-applied by the patients or by their parents to the warts twice a day. Assessment for response and occurrence of adverse effects was performed every 4 weeks until clinical cure. Follow-ups could be arranged in 14 of the 18 patients 1-2 years after total clearance. Sixteen of 18 patients experienced total clearance of their warts; 2 showed partial improvement but were lost to follow-up. The mean duration of treatment was 5.8 months. Two of the 14 patients in whom a follow-up was performed showed a small number of new warts after a period of at least 1 year without recurrence. Our data demonstrate that the topical application of imiquimod 5% cream is an effective treatment for long-lasting cutaneous warts in children.

Reduced sperm count and normal fertility in male mice with targeted disruption of the ADP-ribosylation factor-like 4 (Arl4) gene

The ADP-ribosylation factor-like protein 4 (ARL4) is a 22-kDa GTP-binding protein which is abundant in testes of pubertal and adult rodents but absent in testes from prepubertal animals. During testis development, ARL4 expression starts at day 16 when the spermatogenesis proceeds to the late pachytene. In the adult testis, the ARL4 protein was detected in pre- and postmeiotic cells, spermatocytes, and spermatides, but not in spermatogonia and mature spermatozoa. Mouse Arl4-null mutants generated by targeted disruption of the Arl4 gene were viable and grew normally; male as well as female Arl4(-/-) mice were fertile. However, inactivation of the Arl4 gene resulted in a significant reduction of testis weight and sperm count by 30 and 60%, respectively, without reduction of litter size or frequency. It is suggested that the disruption of Arl4 produces a moderate retardation of germ cell development, possibly at the stage of meiosis.

Pearls and pitfalls: lessons learned in endoscopic robotic surgery- the da Vinci experience

The da Vinci telemanipulation system (Intuitive Surgical, Mountain View, CA) is a computer-enhanced instrumentation system that has helped to overcome some of the limitations of traditional endoscopic instruments. As of May 2001, a total of 1,250 endoscopic cardiac procedures have been performed using the da Vinci system. With the use of wristed instruments and a new generation of endoscopic stabilizers, total endoscopic coronary artery bypass grafting on the beating heart has been achieved in 56 cases. Mitral valve repair and closure of atrial septal defects have been performed successfully through 1 cm incisions in 140 patients. The development of adjunct technologies as well as integration of image-based navigation systems may help to expand the use of computer-enhanced instrumentation systems in the near future.

Low-loss asymptotically single-mode propagation in large-core OmniGuide fibers

We present the light-propagation characteristics of OmniGuide fibers, which guide light by concentric multi-layer dielectric mirrors having the property of omnidirectional reflection. We show how the lowest-loss TE_01 mode can propagate in a single-mode fashion through even large-core fibers, with other modes eliminated asymptotically by their higher losses and poor coupling, analogous to hollow metallic microwave waveguides. Dispersion, radiation leakage, material absorption, nonlinearities, bending, acircularity, and interface roughness are considered with the help of leaky modes and perturbation theory, and both numerical results and general scaling relations are presented. We show that cladding properties such as absorption and nonlinearity are suppressed by many orders of magnitude due to the strong confinement in a hollow core, and other imperfections are tolerable, promising that the properties of silica fibers may be surpassed even when nominally poor materials are employed.

Structural and biologic characterization of pegylated recombinant IFN-alpha2b

The type I interferon-alpha (IFN-alpha) family is a family of natural small proteins that have clinically important anti-infective and antitumor activity. We have developed a semisynthetic protein-polymer conjugate of IFN-alpha2b (Intron A) by attaching a 12,000-Da monomethoxypolyethylene glycol (PEG-12000) polymer to the protein. PEG conjugation is thought to increase the serum half-life and thereby prolong patient exposure to IFN-alpha2b without altering the biologic potency to the protein. Matrix-assisted laser desorption ionization/mass spectrometry (MALDI-MS), high-performance size exclusion chromatography (HPSEC), circular dichroism (CD) analysis and tryptic digestion peptide analysis of PEG Intron demonstrated that the IFN-alpha2b protein was approximately 95% monopegylated and that the primary, the secondary, and the tertiary structures were unaltered. Pegylation did not affect the epitope recognition of antibodies used for Intron A quantitation. An extensive analysis of the pegylated positional isomers revealed that approximately 50% of PEG Intron was monopegylated on the His(34) residue of the IFN-alpha2b protein. The highest antiviral activity of the pegylated positional isomers for PEG Intron was associated with the His(34) pegylated isomer. The specific activity for PEG Intron in an antiviral cytopathic protection assay was 28%, relative to Intron A. However, the potency of PEG Intron, defined as bioactivity independent of protein concentration, was comparable to Intron A at both the molecular and cellular levels in a battery of in vitro assays. Equivalent units of PEG Intron and Intron A were indistinguishable for the induction of several key IFN-induced genes, including 2',5'-oligoadenylate synthetase (2',5'-OAS) and protein kinase R (PKR), in Molt 4 cells. The antiviral dose-response curves revealed that there were no significant differences between PEG Intron and Intron A. This demonstrated that the introduction of more IFN-alpha2b protein associated with equivalent unit dosing of PEG Intron did not create any antagonism or agonism in the antiviral assay. In assays for the immune response, PEG Intron and Intron A displayed comparable potency for both natural-killer (NK) and lymphokine-activated killer (LAK) cell cytolytic activity and for the induction of class I major histocompatibility protein. These results demonstrate that PEG Intron maintains an in vitro biologic potency profile for both antiviral and immunotherapeutic activity that is highly comparable to that of Intron A.

Vitamin A deprivation results in reversible loss of hippocampal long-term synaptic plasticity

Despite its long history, the central effects of progressive depletion of vitamin A in adult mice has not been previously described. An examination of vitamin-deprived animals revealed a progressive and ultimately profound impairment of hippocampal CA1 long-term potentiation and a virtual abolishment of long-term depression. Importantly, these losses are fully reversible by dietary vitamin A replenishment in vivo or direct application of all trans-retinoic acid to acute hippocampal slices. We find retinoid responsive transgenes to be highly active in the hippocampus, and by using dissected explants, we show the hippocampus to be a site of robust synthesis of bioactive retinoids. In aggregate, these results demonstrate that vitamin A and its active derivatives function as essential competence factors for long-term synaptic plasticity within the adult brain, and suggest that key genes required for long-term potentiation and long-term depression are retinoid dependent. These data suggest a major mental consequence for the hundreds of millions of adults and children who are vitamin A deficient.

Intrathecal labor analgesia with bupivacaine and sufentanil: the effect of adding 2.25 microg epinephrine

BACKGROUND AND OBJECTIVES

Epinephrine, 25 microg and 200 microg, has been found to prolong the duration of intrathecal labor analgesia when added to an opioid. In our hospital we use the standard epidural mixture, prepared by the pharmacist, containing epinephrine 1:800,000; i.e., 1.25 microg/mL for both spinal and epidural labor analgesia. We wanted to evaluate whether such a low dose, depending on its effect on duration or quality of analgesia, should be maintained or deleted in future mixtures.

METHODS

Forty-five term parturients were randomly assigned to receive 1.8 mL intrathecally of a mixture containing bupivacaine 0.125% and sufentanil 0.75 microg/mL with or without epinephrine 1.25 microg/mL. The quality and duration of analgesia, side effects, and obstetric/neonatal outcome were compared.

RESULTS

For both combinations, the onset until the first painless contraction was between 5 and 6 minutes. Most patients were pain free during the second uterine contraction. The duration of complete analgesia was 93.2 +/- 24.2 minutes in the epinephrine group and 79.3 +/- 18.1 minutes for patients not receiving epinephrine (P = .014). The quality of the block, bupivacaine consumption, side effects, and obstetric/neonatal outcome were not different between groups.

CONCLUSIONS

It was concluded that epinephrine in a dose as low as 2.25 microg significantly prolonged the duration of intrathecal analgesia of bupivacaine-sufentanil by 15 minutes. No other differences were noticed. Diluting the commercially available bupivacaine 0.5% with epinephrine 1:200,000 may avoid the need of freshly prepared epinephrine solutions.

Population pharmacokinetic analysis of pegylated interferon alfa-2b and interferon alfa-2b in patients with chronic hepatitis C

BACKGROUND

This study quantified pharmacokinetic changes in pegylated and nonpegylated interferon alfa-2b during 48 weeks of treatment and the influences of covariates on the basis of sparsely sampled serum concentrations and activity values. Possible relationships between pharmacokinetic and pharmacodynamic variables were investigated.

METHODS

Patients with chronic hepatitis C were enrolled in a clinical trial that compared the efficacy of pegylated interferon alfa-2b with interferon alfa-2b. Single blood samples were obtained from each patient at weeks 4, 12, 24, 36, and 48. Three pharmacostatistical models were developed for 2 immunoassays and 1 bioassay.

RESULTS

Apparent clearance values of pegylated interferon alfa-2b and interferon alfa-2b at the end of treatment declined 33.7% and 80.0%, respectively, from their week 4 values. Bioactivity increased 41% to 58% at week 48 for different treatment groups. Changes were greatest in the first weeks of administration and diminished during the subsequent months. Body weight had a modest positive effect on clearance values and activity. Within each dose level, no significant associations were observed between pharmacokinetic variables and any pharmacodynamic variables (hepatitis C virus--RNA responses or changes in neutrophils and platelets).

CONCLUSIONS

This analysis confirms earlier observations of progressive pharmacokinetic changes in the patients with hepatitis C during 48 weeks of treatment. The absence of a relationship between toxicity or efficacy variables and interferon concentration or activity (within a dose level) suggests that clinical management of patients (eg, for efficacy or to manage toxicity) should be based on clinically derived dosing guidelines rather than on serum concentration or activity criteria.

Computer-enhanced "robotic" cardiac surgery: experience in 148 patients

OBJECTIVE

A computer-enhanced instrumentation system was used in 148 patients to minimize access in cardiac surgical procedures.

METHODS

The da Vinci telemanipulation system (Intuitive Surgical, Mountain View, Calif) provides a high-resolution 3-dimensional videoscopic image and allows remote, tremor-free, and scaled control of endoscopic surgical instruments with 6 degrees of freedom. By April 2000, the system had been used in 131 patients for coronary artery bypass grafting and 17 patients for mitral valve repair. In the coronary bypass group, the system was used in one of three ways: (1) to take down the internal thoracic artery followed by a minimally invasive direct coronary bypass procedure (n = 81); (2) to perform the anastomosis between the internal thoracic artery and the left anterior descending coronary artery in standard-sternotomy coronary bypass (n = 15); or (3) for total endoscopic coronary artery bypass grafting to anastomose the left internal thoracic artery to the left anterior descending on the arrested heart (n = 27) or the beating heart (n = 8). In 17 patients with nonischemic mitral valve insufficiency the mitral valve was repaired. Closed-chest cardiopulmonary bypass with cardioplegic arrest (Port-Access technique; Heartport, Inc, Redwood City, Calif) was used for arrested-heart total endoscopic coronary bypass and mitral valve repair.

RESULTS

The da Vinci system allows for precise tissue handling and enables the endoscopic performance of cardiac surgical tasks that require a high degree of dexterity (coronary anastomosis, mitral valve repair). No technical mishaps have occurred. The internal thoracic artery was successfully taken down in 79 of 81 patients in the group undergoing minimally invasive coronary bypass and, after a steep learning curve, is currently performed in less than 40 minutes. The postoperative patency rate is 96.3%. Total endoscopic coronary bypass was completed in 22 of 27 cases with 95.4% patency as demonstrated by angiography at 3 months' follow-up. Closed-chest endoscopic beating-heart bypass grafting was successfully performed in 2 out of 8 patients with the use of a new endoscopic stabilizer. In the group having mitral valve repair, primary endoscopic computer-enhanced repair was successfully completed in 14 of 17 patients; three others had to be changed to a standard endoscopic technique, including 1 who required valve replacement. At 3 months' follow-up, 1 additional patient underwent early reoperation for recurrent mitral insufficiency. Overall early and late mortality in this cohort of 148 patients was 2.0% and was not related to the use of the system.

CONCLUSION

In conclusion, computer-enhanced endoscopic cardiac surgery can be performed safely in selected patients. Internal thoracic artery takedown is now routinely performed with good results. Total endoscopic coronary bypass is feasible on the arrested heart but does not offer a major benefit over the minimally invasive direct approach because cardiopulmonary bypass is still required. The early clinical experience with closed-chest beating-heart bypass grafting outlines the limitations of this approach despite some procedural success.

Comorbid anxiety and affective disorder in alcohol-dependent patients seeking treatment: the first Multicentre Study in Germany

The goals of this study were to describe demographic variables, drinking history, and the 6-month prevalence of Axis I comorbidity among alcohol-dependent subjects in GERMANY: The variables: amount of alcohol consumption, age at onset of the first alcohol consumed, age at onset of daily alcohol consumption, age at onset of withdrawal symptoms and number of detoxifications were related to the different comorbid disorders and gender. In this study, 556 patients from 25 alcohol treatment centres were enrolled between 1 January 1999 and 30 April 1999. After a minimum of 10 days of sobriety patients who fulfilled ICD-10 and DSM-IV criteria of alcohol dependence were interviewed for data collection using the Mini-DIPS (German version of the Anxiety Disorders Interview Schedule) and a standardized psychosocial interview. The 6-month prevalence of comorbid Axis I disorders was 53.1%. Among the patients with comorbidity, affective and anxiety disorders were most frequent. Comorbid stress disorder was associated with an early start of drinking, an early beginning of withdrawal symptoms, highest number of detoxifications, and the highest amount of alcohol consumed. Female patients with anxiety disorder consumed more alcohol and started earlier than females without this comorbid disorder. The data do not answer the question of the pathogenesis of comorbid disorders and alcoholism, but indicate that stress disorders in alcoholic patients and anxiety disorders in female alcoholics influence the course and severity of alcoholism.